[Histological examination of changes due to aging in the femur compacta of laboratory and house mice]. The age changes in the histological structure of the femur corticalis in ICR laboratory mice (from 20 to 300 days) and in house mice (from 50 to 520 days) were studied. In both forms of mice the circumferential lamellae prevailed, with increased age they are substitued by secondary but mainly primary Haversian systems and the interstitial systems of vartious shape. Certain differences in the construction of the femur corticalis, were found in both species of mice; from among the latter the mouse is more suitable for the demonstration of age changes.


A micromorphological study of the female copulatory organs of buffaloes in Egypt (Bos bubalus L.). Samples from the different regions of the external genitalia of the Egyptian female buffalo, at different ages and different periods of the oestrus cycle, were examined microscopically after different strains. The walls of both vagina and its vestibule comprised mainly 3 coats; mucosa, musculosa and adventitia. The epithelia lining undergoes changes according to the period of the cycle. The circular muscle layer of vagina splits into 2 in the ventral wall and sandwitches in between a longitudinal layer and reunites oncemore in the dorsal wall. The lamina propria of the vestibula contains the following glandular structures: a) intraepithelial mucussecreting cells, b) large subepithelial glandular masses lying 1/2 cm caudal to hymen and extending for 3 cm caudally and 1 cm laterally in both dorsal and ventral walls, taking the form of compound tubuloaveolar muco-serous glands, and c) small glandular masses lying in the ventral median plane from the region of the fossa clitoridis and gradually disappearing cranially towards the suburethral diverticulum, taking the form of compound alveolar mucous glands. The clitoris is wholly formed of erectile tissue with smooth muscle fibers at its root and fat cells at its tip (glans). However, the latter cells were absent from calves.


[Position of tylopoda in the system of placental mammals]. Anatomical features of the Tylopoda are determined to a great extent by the convergence with the Ruminantia. The dental system adapted to the double mastification of plant food. The convergent character of the structure of limbs follows from the reduction of carpal and tarsal bones in the Tylopoda and their presence in the Ruminantia. The Ruminantia have no mandibular angular processes which are present in the Tylopoda. In the Tylopoda, the foramina in the transversal processes of cervical vertebrae from a canal by which the vertebral artery opens in the brain. In the Ruminanta there is no such a canal. The embryonic development of camels is characterized by the promitive features of provisory organs. The mating of camels occurs in winter, a feature probably showing that they have preserved the reproduction cycle of the Southern Hemisphere animals.


[Lymphocyte aggregation in the intermediate part of the human pituitary gland as an expression of H. Bautzmann's lympho-glandular unit]. The lymphocytic aggregates in the pars intermedia of the human pituitary are preferentially situated among the mucous glands and colloid cysts. This localization gives rise to interpret them as expression of a functional unit which was pointed out by H. Bautzmann as a rule within all exocrine glands.


[Organogenetic development of muscles in the deep extensor layer of the front limb in the golden hamster (Mesocricetus auratus)]. The author has investigated a complete series of cross-sections of thoracic extremities of the embryos and foetuses of Mesocricetus auratus of different age. He describes the successive stages of manifestation and differentiation of the deep-layer primordia of the extensor muscles of the fingers. He treats the facts also of an evolutionary myology point of view.


[Histological and histochemical studies on the detection of the esogaster in the agastric cyprinidae Aristichthys nobilis Rich. (Marble carp)]. In postnatal Aristichthys nobilis Rich. oesogaster was proved by histological and histochemical methods. During the larval development oesogaster becomes reduced completely in cranial direction. The statement is demonstrating the secondary character of lost stomach in phylogeny of this fish species.


[The existence of M. peroneus digiti IV and of M. peroneus digiti V in the distant predecessors of man]. Recent evolutionary myological researches on the m. peroneus digiti IV and m. peroneus digiti V in Man have shown that these muscles had been at first an inseparable component of his peroneal musculature. The above mentioned muscles have undergone practically a full reduction in the course of man's phylogenesis. The peroneal muscular group of the pelvic limb of the Mesocricetus auratus consists now of m. peroneus longus, m. peroneus brevis and both m. peroneus digiti IV et m. peroneus digiti V. In other words, the situation is the same as in the Prosimia. The comparasion of the organogenesis of the muscles in question in Man and in the golden hamster shows that the morphology and topography of their primordia on the proximal parts of the metatarsus in the Man's embryo of 14 mm CRL are the same as in the embryo of Mesocricetus auratus of 11 d and 18 h. The development of this common primordium is different after that age of the embryos of both mammalian species. It reduces and usually completely disappears in Man, while in Mesocricetus auratus it gives rise of the tendons of the m. peroneus digiti IV and the m. peroneus digiti V. Thus the present research proves that the primordium in the proximal parts of the metatarsus of Man's embryo with 14 mm CRL is a tendo-forming plate of the tendons of the m. peroneus digiti IV and m. peroneus digiti V.


The adaptive mandible: a product of the relative osteo-neural growth. The growth interrelation existing between the developing brain and its bony case (with the brain representing the morphogenetically determining structure to the shape and size of which the neurocranial bony envelope is adapted) is to be conceived just as a special case of a general phenomenon, the osteo-neural relation, which works throughout the entire vertebrate body. The morphological manifestations of this relation may be disclosed in the axial as well as in the appendicular skeleton. In the present communication the osteo-neural concept is applied to the morphogenesis of the facial skeleton with special reference to the mandible. The more or less elongated shape of the mandible in various species of vertebrates depends on the phylogenetically established higher or lesser degree of growth potentiality of the mandibular nerve. With the increasing size of the brain in the course of hominization the growth-in-length capability of the mandibular nerve is (compensatorily?) decreased with corresponding shortening of the mandible and with appearance of the chin. The proposed interpretation is supported by a model experiment. The highly characteristic shortening and angulation of the lower beak which may be produced experimentally in the chick embryo by a great variety of teratogens, is related most probably to the same underlying mechanism, viz., to the primary inhibition of the highly susceptible neural growth with the secondary adaptive deformity of the beak. Pierre-Robin-Syndrome (cleft palate and micrognathia) may be readily explained by a growth insufficiency of the palatine and mandibular nerves.


Attributional error and attitudes toward aging: a view of the NCOA national attitude survey. Attitudes toward aging obtained in the National Council on Aging national attitude survey are examined in light of recent developments in attributional theory. A specific principle drawn from each of the three major attribution theories is applied to findings from the survey. It is argued that (a) mandatory retirement policies may be attributionally preferable to retirement based on demonstrated incompetence, (b) opinions of older people are shaped by attributions made to the role, and (c) the attributional focus of the helping professions may perpetuate the negative view of aging. Suggestions are made for research on aging.


Social and psychological determinants of adaptation. Social and psychological frameworks used to explain adaptation are examined. Findings from a study of three ethnic groups, Irish, Italian, and Polish Americans, aged forty to eighty are presented to test the effects of life stage, social surround, and personality on adaptation.


Conservatism, innovation and old age.

Conservatism, innovation and old age. The onset of old age can be understood as a sequence of losses--of relationships, physical abilities, functions--which must be grieved. It represents a kind of psycho-social transition, whose generic characteristic is a breakdown in the structure of meaning by which we interpret events and which forces us to re-interpret that structure before we can assimilate the events that have provoked the breakdown. The better we understand such transitions as retirement, and loss of health, the more likely we can find ways to create the social and psychological conditions in which to work through the grief. The attitudes of American society towards old age tend to make these transitions harder than they need be.


Aging and primary relations.

Aging and primary relations. After listing all consanguinal and affinal kin, our sample of 800 respondents forty-five and older identified those with whom they felt very close and who among these were confidants. A parallel procedure was used to identify very close friends and confidant friends. These four types (primary relatives, confidant relatives, primary friends, confidant friends) were seen as constituting the primary-group resource of our respondents. Thirty of the 800 individuals lacked primary ties with kin, compared to 118 of 800 without primary ties with friends. While very few of the respondents were without very close ties of any kind, those with extensive primary-group resources were more likely to be women rather than men, younger rather than older, married rather than single, and in high rather than low-status occupation.


"Don't tread on me": ethological perspectives on institutionalization. The concept of dignity is developed from an ethological perspective. Special attention is given to innate, phylogenetically programmed behavior, the role of releasers, the importance of rituals, and the fact that "management problems" in institutions are often cries for dignity. Observations of geriatric patients admitted to a nursing home are given, but it is believed that the generalizations apply equally well to institutionalization in other settings such as residential centers for young people, correctional facilities, or mental hospitals.


The five per cent fallacy.

The five per cent fallacy. Using the Kastenbaum and Candy study of locations where persons aged sixty-five plus died over the period of one year in a large metropolitan city as a model, this study examined the place of death for persons aged sixty-five plus in a middle-size city. In both studies particular attention was paid to nursing homes and extended care facilities to determine whether or not the commonly accepted figure of 5 per cent accurately reflects the number or persons actually living in such facilities. The premise was that if persons died in such a facility, then they had in fact lived there. This study demonstrates, as had the Kastenbaum and Candy study, that the actual percentage of persons dying in these institutions far exceeds the commonly held 5 per cent.


Social psychology and gerontology: a discussion. The four papers of this symposium on social psychology and gerontology are critically discussed: Babchuk on primary relation, Shaver on attribution theory, Marris on conservation and innovation, and Lieberman on adaptation.


Training response speed in young and elderly women. Effectiveness of response speed training on the performance of thirty adult women was assessed. Five young and five elderly female volunteers were tested in each of three experimental conditions: (1) one training session with cognitive feedback in which participants were given response rate information (control); (2) five training sessions with cognitive feedback (practice); or (3) five training sessions with cognitive feedback in which the number of S&H green stamp units earned was directly proportional to response rate (conjugate reinforcement). Dependent variables were (a) response speed on three paper-pencil tasks, and (b) postraining performance on twelve intelligence subtests chosen as far transfer tasks. Response speed increased significantly with training in both age groups, but contrary to expectation, young adults showed greater training effects than elderly adults. No significant far transfer effects were obtained.


Performance on tests of power and speed as related to age among male job applicants. A number of ability tests were administered to 187 male job applicants ranging in age from twenty to fifty-three years. When test-performance was compared across age groups, no significant differences were found on tests of mental ability, numerical ability, reading speed and comprehension, and mechanical comprehension. On one of two verbal comprehension tests, scores increased significantly as a function of age. Moreover, the older individuals were not penalized in any way by tests which emphasized speed as opposed to power. The findings were discussed in connection with the generally negative stereotype of the aging worker.


Cognitive rigidity in the aged and the mentally retarded. Three groups, one of elderly, one of young mentally retarded, and one of non-retarded young persons were compared on a visual recognition task which involved changing from one category of identification to another. The mentally retarded participants had greater difficulty in changing categories than did the non-retarded participants. Results for the elderly were similar but may have been partly due to the choice of stimulus material. In a second task, the same elderly and non-retarded young participants named as many objects as possible in one minute. The elderly group produced fewer responses on average than the young group and fewer categories of such responses. Results suggested that older persons find it more difficult to change between different categories of identification.


The effects of physical changes on clothing preferences of elderly women. Various physiological and biological changes occurring during senescence have an affect upon the clothing needs and preferences of elderly women. Data were collected by personal interview from thirty-eight women age sixty-five or older in Lexington, Kentucky. The results indicate that ready-to-wear garments do not accommodate the clothing needs of elderly women; garments did not allow for increased trunk girth, decreased height, or for physical impairments.


Symbolic interaction and retirement adjustment: an empirical assessment. Using a variety of indicators of retirement adjustment most studies have focused on two variables as the critical ones: the kind of work the individual was involved in prior to retirement with its concomitant style of life or the individual's pre-retirement attitudes. Focusing on the latter variable and using a symbolic interaction perspective, it was hypothesized that the individual's significant others are crucial to both the development of his pre-retirement attitudes and his post-retirement adjustment. The data upheld both the predicted relationships, and further suggest that the social world of older people is comprised of both primary groups and proximate others. The Lowenthal and Haven concept of confidants as a major factor in the adjustment of older people, though valuable, too narrowly defines their social world. The broader concept of significant others comprised of both confidants and proximate others seems more realistic.


Public Interest Report No. 27 : The need for teaching geriatric medicine. Geriatric medicine, the body of knowledge relating to human aging and associated pathological conditions, must be incorporated systematically and comprehensively into American medical education. Students must be exposed to aging in the context of normal human development and be aware that some diseases present differently in the old.


The broadening of perspective over the career course: an exploratory study of self-reported creative research acts. Data collected from questionnaires mailed to a systematic sample of full professors were used to test the hypothesis that as persons advance through career stages, they are granted greater latitude in, and have greater inclination for, the expression of creative research activity within a broader perspective. Empirical support was found for this hypothesis. Even stronger support was obtained from a more recent cohort whose members may be part of a more career oriented discipline. Knowledge about the processess of career development and the trend toward increased breadth can lead to continued satisfaction for an individual over his/her career course, and the accomplishment of organizational objectives.


Age and social composition factors as explanations for cleavages in socio-political values. While age group differences on social and political values have been frequently documented in survey data, it is often claimed that these differences are due to social composition factors rather than to age itself. In this analysis we test for the effects of age vs. social composition in explaining variation in four attitudinal dependent variables. Using a sample especially drawn to study generational differences, and employing a multivariate statistical model, it was found that age differences were only modestly reduced by social composition variables. It is concluded that nonartifactual age group differences do exist on the dependent variables.


Temporal experience in the aged: body integrity and the social milieu. Variation in temporal experience among the aged has been found to be a function of a number of variables. The sociological and phenomenological literature suggest two as being of crucial importance: work and retirement and health and illness. These were investigated in the present study making use of a structured interview format with seventy male retirees. Differences in affect and temporal experience were examined using a 2 x 2 x 2 factorial design comparing groups in terms of Health, Willingness to Retire, and Time Since Retirement. In general, it was found that early in retirement those individuals who were healthy but had not wanted to retire resembled the chronically ill in terms of negative affect and temporal structure (that is, loss of a sense of future, constricted present, and "disconnected" past). Over time, however, these individuals restructured their world, reflecting a positive affect and a "full" temporal experience. This restructuration was in contrast to that which occurred in the chronically ill, who, irrespective of whether they wanted to retire or not, and irrespective of time since retirement, remained uniform in terms of negative affect and loss of temporal structure.


A model for analyzing the aging of local populations: Illinois counties between 1950 and 1970. The article develops a model which explains the aging of local populations, expressed in terms of percent of the population over sixty-five years, in terms of the net movement of the young and the elderly, as well as socio-economic characteristics of the local population. The model is illustrated for data from Illinois counties for the period 1950-1960 and 1960-1970. The model represents the data for the 1960's more accurately than the data for the 1950's.


Attitude instrument analysis: an examination of factor consistency across two samples. The factor analytic model of the practitioner-oriented opinions about people (OAP) was tested with a population of gerontological practitioners (N =558). A confirmatory factor analysis was performed to ascertain the degree-of-fit between these data and the published OAP factor model. After results supported the hypothesis that the two samples differed, a second factor analysis was designed to yield estimates of communalities by a least squares multiple regression technique. This analysis eliminated nine items not warranting inclusion in the instrument, redistributed the factors, and brought out a completely new factor. Finally, to test the hypothesis that attitudes toward aging and the aged are uncorrelated, a third analysis was performed in which the six scales of the oblique solution were refactored. The resulting higher order dimensions tended to support this hypothesis.


1978 memorial award paper: a computer-aided technique for overlaying cerebral angiograms onto computed tomograms. We have developed a method which uses a digital computer to combine angiographic images of the cerebral vasculature with a computed tomogram of the brain. The procedure is simple and could be implemented in any radiology department equipped with both a CT scanner and a bi-plane angiography suite. We have performed the entire process in prototype on phantoms and on a patient and have produced images that appear accurate and informative.


Qualitative distortion at fluid-air interfaces during echography of simulated pleural effusions. Beams of diagnostic ultrasound passing through pleural effusions produce an irregular band of complex echoes, when such beams strike aerated lung. To simulate pleural effusions and study this fluid-gas interface, we scanned latex bags of water and air which lay in a water bath beneath a uniform portion of veal rib cage. The general shape of an air-containing object could be determined under these conditions. The display of the upper surface of the gas-filled object was broad and heterogeneous but this zone of distortion was thin in relation to the overlying fluid layer. Fluid thicknesses exceeding 1 cm could be detected under these conditions even when they abut gas-filled structures. These preliminary data suggest that complex artefacts occurring at fluid-gas interfaces during echography of laboratory models simulating pleural effusions would not preclude useful volumentric estimations of overlying fluid layers.


Radiologic evaluation of cerebrovascular disease in experimental atherosclerosis in a subhuman primate model. In a series of animal experiments to provoke atherosclerosis, angiographic evaluation of the cerebral vessels was obtained. The angiographic evaluation of cerebral changes and correlation with the pathological alterations known to occur illustrate the value of this technique in long term analysis of induced atherosclerosis in the experimental animal. Control groups, high cholesterol diet groups, and induced hypertensive groups with and without a high cholesterol diet were evaluated by serial angiographic techniques. Examples of angiographic changes are demonstrated and have proven of considerable value in following the progress of the vascular changes.


Experimental progressive muscular dystrophy and its treatment with high doses anabolizing agents. We are still a long way from discovering an unequivocal pathogenetic interpretation of progressive muscular dystrophy in man. Noteworthy efforts have been made in the experimental field; a recessive autosomic form found in the mouse seems to bear the closest resemblance to the human form from the genetic point of view. Myopathy due to lack of vitamin E and myopathy induced by certain viruses have much in common anatomically and pathologically with the human form. The authors induced myodystrophy in the rat by giving it a diet lacking in vitamin E. The pharmacological characteristics of vitamin E and the degenerative changes brought about by its deficiency, especially in the muscles, are illustrated. It is thus confirmed that the histological characteristics of myopathic rat muscle induced experimentally are extraordinarily similar to those of human myopathy as confirmed during biopsies performed at the Orthopaedic Traumatological Centre, Florence. The encouraging results obtained in various authoratative departments in myopathic patients by using anabolizing steroids have encouraged the authors to investigate the beneficial effects of one anabolizing agent (Dianabol, CIBA) at high doses in rats rendered myopathic by a diet deficient in vitamin E. In this way they obtained appreciable changes in body weight (increased from 50 to 70 g after forty days at a dose of 5 mg per day of anabolizing agent), but most of all they found histological changes due to "regenerative" changes in the muscle tissue, which however maintained its myopathic characteristics in the control animals that were not treated with the anabolizing agent. The authors conclude by affirming the undoubted efficacy of the anabolizing steroids in experimental myopathic disease, but they have reservations as to the transfer of the results into the human field, where high dosage cannot be carried out continuously because of the effects of the drug on virility; because the tissue injury too often occurs at an irreversible stage vis-a-vis the "regeneration" of the muscle tissue; and finally because the dystrophic injurious agent is certainly not the lack of vitamin E but something as yet unknown.


Arrhythmogenic and cardiodepressive effects of contrast media on isolated rat atria. The cardiotoxicity of four radiopaque contrast media were studied on spontaneously beating isolated rat atria in order to compare the low-osmolar non-ionic medium, metrizamide, with three other contrast media having different cation compositions. The addition of the ionic contrast media to concentrations of 28 and 84 mg I/ml induced atrial arrhythmias in the following order of potency: meglumine iothalamate greater than meglumine--Na--Ca metrizoate greater than meglumine--Na diatrizoate. No arrhythmias were observed after the addition of metrizamide. Metrizamide had only slight effects on the rate and amplitude of the atrial contractions, and hence the work index was almost unaffected. The highest concentration of the three ionic contrast media had very significant cardiodepressive effects. Meglumine iothalamate had the most severe influence on the spontaneous rate of the contractions, while meglumine--Na diatrizoate induced the greatest initial reduction in the amplitude of the contractions and the work index. The present study indicates that the low-osmolar non-ionic medium, metrizamide, is better tolerated by the myocardium than the ionic contrast media.


Secondary treatment of fractures of the middle and lower third of the tibia unsuccessfully treated by primary internal fixation. The authors present forty six cases, referred to us between 1969 and 1974, of fracture of the middle and lower thirds of the tibia, previously treated elsewhere by primary internal fixation using a plate and screws. The causes of failure are divided into defective indications and defective technique. The methods of treatment used in infected and non-infected lesions are described. They criticise the unnecessary use of plates and explain their reasons. They do not condemn the method outright, since in selected cases IT IS UNDOUBTEDLY A VALID METHod of treatment. They are opposed, however, to its indiscriminate use for lesions that may perfectly well be cured, with the minimum risk, either by conservative methods, or by intramedullary nailing.


Osteosynthesis of fractures of the femur with flexible metallic intramedullary nails. The authors discuss their use of Ender's method in the treatment of fractures of the femur. The diameter and length of the nails depends on the type of fracture. 1) Three nails of 4 mm diameter are introduced in parallel from the medial condyle in fractures of the femoral neck; 2) 5 mm nails are used, in similar fashion, for the fixation of intertrochanteric and subtrochanteric fractures; 3) 5 mm nails are used for diaphyseal, supracondylar and intercondylar fractures, introduced in crossed fashion ("Eiffel Tower" technique) from both medial and lateral condyles. This method of fixation has proved to be extremely stable. The operation itself is quick, with no blood loss or shock. The patient can resume partial weight bearing after a week in stabilised intertrochanteric and shaft fractures, after a month in less stable types, and after three to four months in fractures of the neck of the femur. This report is based on the first 250 cases treated by this method.


Some effects of method on the measured conspicuity of chest lesions. Both the magnitude and the precision of the conspicuity of a series of solitary chest nodules depends on the number and spacing of the measurement points. Observer accuracy in detecting 1.0 cm and 1.5 cm psuedo chest lesions does not correlate well with conspicuity.


Operative indications in fractures of the calcaneus: problems of reduction and fixation. In fractures of the calcaneus the fundamental importance of complete restoration of the architectural structure of the bone is stressed. To this end, the technique of internal fixation calls for a special device. Three different types of plate are described and the indications for each discussed.


Physical characteristics of modern radiographic screen-film systems. The most important characteristics that determine the performance of a screen-film system are system sensitivity (speed), slope or the average gradient of the characteristic curve, latitude of the film, system resolution (MTF) and system noise. In addition to these, one has to consider secondary characteristics such as the base plus fog level, the base tint, safelight sensitivity, reciprocity law failure and film granularity while evaluating performance. A comprehensive study of many of these characteristics has been made for a number of film-screen systems on the market. The data has been tabulated in the form of what are called "characteristic tables of radiographic film-screen systems." In these tables, characteristics such as average gradient, base plus fog level, etc. which depend on film alone, appear along the horizontal axis and MTF values which essentially depend on screens only appear along the vertical axis. The body of the table contains the absolute speeds in units of mR-1 at 80 KVP (heavy filtration) and a quantum mottle index of the various film-screen combinations tested, since these depend both on the film as well as on the screens.


Reduction and immobilization for Colles fracture. Maintenance of reduction in Colles fracture can be difficult to achieve. Some of the positions of the wrist in plaster designed to prevent redisplacement produce subsequent difficulty in the recovery of function of the wrist and hand. The author has practised a technique, in a large number of cases, using plaster with radial and dorsal indentations, which has proved capable of maintaining reduction with the wrist in a "physiological" or neutral position. The details of the technique are described and the end results in 162 patients are analysed.


A new method for the quantitative determination of osteoporosis in man. The authors studied a technique based on the use of a radiographic negative in antero-posterior projection of the third lumbar vertebra, from which the index of osteoporosis was obtained quantitatively by spectrophotometric examination. This index is about 0.50 in normal cases and approaches unity in cases of osteoporosis.


Fractures of the intercondylar tibial eminence. Fractures of the intercondylar tibial eminence are produced by a mechanism similar to that of rupture of the cruciate ligaments, in particular excessive internal rotation in varus and external rotation in valgus. When combined with other types of force there may be associated lesions of other structures, which naturally complicates the treatment and prognosis. Screw fixation is not considered satisfactory, both because of its difficulty when the posterior tuberosity is involved, the need for a second operation to remove the screw, the frequency with which the fragments break during or after the application of the screw, and the possibility that the screws may loosen. Fixation is performed by means of a metal wire transfixing the fracture, passed through two tunnels in the tibia, and anchored on the anterior surface of the tibia over a small metal plate, in order to prevent cutting through the bone under tension. It is important that the two small tunnels drilled in the tibia should exactly meet the fracture line.


Arthroprostheses without cement in osteoarthrosis of the hip (preliminary report) (16 cases of Sbarbaro arthroprosthesis). The authors report the results obtained with arthroprostheses without cement. In this preliminary report they examine sixteen cases treated with Sbarbaro's arthroprosthesis from 1972 to 1976, at the Orthopaedic Division of the Specialized Regional Hospital, Udine. They stress the efficacy of this kind of arthroprosthesis, which can be used in subjects under the age of sixty years who have severe bilateral lesions, especially of the femoral head. The operation is contraindicated when there is severe dysplasia of osteoporosis of the acetabulum. Weight bearing must be avoided for six months, the time required for the noncemented arthroprosthesis to become stabilized. The two poor results were attributable to local metabolic changes in one case, and general changes in another, rather than to the arthroprosthesis itself.


Posterior dislocation of the acromio-clavicular joint: a rare or an easily overlooked lesion? The authors describe a case of posterior acromio-clavicular dislocation treated operatively. The etiology and pathological anatomy are discussed and the importance of an axial radiographic projection is emphasized. Radiographic comparison with the normal shoulder is helpful in leading to a correct diagnosis.


Jumper's knee.

Jumper's knee. The authors present a clinical study on twenty six cases of a painful syndrome affecting the distal quadriceps tendon complex, popularly known as "jumper's knee". They review the diagnostic aspects and discuss the treatment. In particular, they suggest a surgical approach that is not limited to the inflammatory or degenerative component of the syndrome, but also aims to correct imbalance of the extensor apparatus.


Course and prognosis of bone cystinosis in adolescent and or adults. The authors refer to their observations on a case reported five years ago. On the basis of electron microscopy findings it was classified as benign bone cystinosis of the adolescent or of the adult. His subsequent clinical recovery, and the present radiographic findings, which show spontaneous and almost complete repair, confirm the validity of the diagnosis and the importance of electron microscopy in the etiology of this rare bone lesion.


Vertebral localization of echinococcosis (case report with medullary compression). A case is presented of cord compression due to vertebral echinococcosis which relapsed after a first laminectomy elsewhere. The authors carried out a second excision with decompression from the anterior approach, supplemented by grafting. After a period of recovery and well being, relapse occurred with renewal of the cord compression. A second decompressive laminectomy and excision of the relapsed cyst was carried out. The present case illustrates the limitations of surgery in this parasitology, because of the extreme liability to relapses.


The surgical treatment of Kienböck's disease. A long term follow up of thirty two patients operated on for Kienböck's disease of the semilunar bone at the Istituto Ortopedico Toscano in the last twenty eight years has been carried out. Three types of operation were performed; excision of the semilunar, lengthening of the ulna, and shortening of the radius. The best results were obtained from shortening the radius. Good results were also obtained in cases in which there was no preoperative relative shortening of the ulna at the inferior radio-ulnar joint.


Surgical treatment of congenital club foot. (Comparison of the results of Codivilla's operation with those of Turco's modification). The purpose of this paper is to compare the results of the classical Codivilla operation with those obtained from the same operation as modified by Turco. The authors have assessed ninety one feet in sixty eight patients treated between 1968 and 1975. The severity of each foot was assessed before and after corrective treatment according to the classification of Manes et al., 1975. The results were determined according to the classification of Mastragostino et al., 1976, based on the clinical, radiographic and functional findings. In this connection, the authors attached particular importance to the dorsiflexion test. Based on their findings in this survey, the authors assert that Turco's modification of the classical Codivilla operation enhances the results.


Measurement of valgus and varus deformity in the lower limb. A method is proposed for measuring deformities of the femur and tibia in the frontal plane. This forms part of a complex system of clinical and radiographic evaluation, suitable for the planning or surgical operations.


Detachment of the accessory fragment in "patella partita". The authors report six cases of detachment of the accessory fragment in "patella partita". This lesion is often unrecognised, especially among athletes. It gives rise to painful symptoms that are at first severe and later less marked. These symptoms disappear completely in both acute and chronic cases with the removal of the detached accessory fragment.


Ossifying granulomatous periostitis in the course of erythema nodosum. The author records a case of ossifying periostitis of the tibia apparently due to erythema nodosum. This does not appear to have been recorded previously. The histology, aetiology and differential diagnosis are discussed. The mechanism is probably one of direct spread from skin to periosteum.


Early mobilisation and functional re-education in the post operative treatment of prolapsed lumbar disc. After operations for prolapsed lumbar disc, the authors recommend early resumption of the erect posture combined with a programme of re-education. This is started during the first days after the operation and continued for three months. In most cases it assists the rapid recovery of spinal function. The best results are obtained in patients in whom the operation completely relieves the nerve root symptoms. The programme of re-education, begun early, presents no problems if excessive strain on the lumbar spine is avoided during the first seven to nine days after operation.


Behavioral responses in 7 to 9 month old infants to speech and non-speech stimuli. A comparison was made of the behavioral responses of 36 infants (18 M, 18 F) aged 7--9 mo, to natural speech, warbled tone of 3 kc/s. and a noise band of 2--4 kc/s. The intensity level for speech was significantly lower, and the number of responses for speech was significantly higher, than for the other two stimuli. Girls demonstrated a significantly lower mean threshold and a significantly higher number of responses than boys. The threshold means for all three stimuli were significantly lower and the number of responses were significantly higher for the R ear than for the L ear in girls, but not in boys. There was no difference in threshold means for speech between the L and the R ears for the whole population, but there was a significantly higher number of responses to speech stimuli by girls, but not for boys, in the R ear than in the L ear.


Remote masking in presbycusis.

Remote masking in presbycusis. Remote Masking (RM) (a rise in threshold for low-frequency tones when the ear is exposed to a high intensity noise band of high frequency) has been attributed to mechanical nonlinear distortion of the cochlear partition, as an effect of the envelope of a nonuniform signal. Clinical studies using RM have revealed RM is normal only when both the endolabyrinthine pressure and the cochlear hydrodynamics are normal. Increasing the stiffness of the cochlear partition affects adversely the mechanism of motion of the cochlear duct and reduces RM values. We studied RM in normal young Ss and in patients with presbycusis in order to determine whether aging of the inner ear also induces stiffness of the cochlear partition. In presbycusic Ss the RM values were indeed reduced symmetrically in both ears and progressively as a result of aging. Thus RM demonstrates the existence of cochlear conductive presbycusis and can be considered a useful test of stiffness of the cochlear partition.


A comparison of procedures in "otometry": absolute versus equal-loudness judgments. Normal-hearing men and women (N: 20) judged damped wave signal trains (3/sec; fc = .35, .5, .7, 1, 1.4, 2, 2.8, or 4 kc/s) to be on the verge from "normal" to "loud," and from "normal" to "soft." Judgments were binaural about 1 m from a loudspeaker. "Normal" (most comfortable ?) loudness was calculated at halfway in db between the two transition zones. A replication showed that 70% of Ss yielded the same "Normal" within 9 db for all fc, while only 35% could yield the same "Normal" within 6 db for all fc. Mean "Normal" for 1 kc/s was 72.8 db SPL re 20 mu Pa. Ss made equal-loudness judgments by adjusting other fc to this standard. Variances of equal-loudness judgments were 2--3 times better (smaller) than of "Normal" estimates. It was suggested that "Otometry" utilize the equal-loudness measurement procedure recommended originally by Victoreen (J. Acoust. Soc. Am., 1974, 55, 309-312).


Tactile perception of stress and intonation. Tactile perception of alteration in sentence meaning due to modification of intonation and stress patterns was determined for 10 normal hearing young adults. Stimuli consisted of sentences varying with respect to syllable length (4--7 syllables), place of stress (initial, medial or final), or intonation type (rising, steady or falling). All stimulus items were presented to the fingers by a bc oscillator at 15 db re vibrotactile threshold. Analysis of data using Chi Square yielded significant results for tactile perception of stress but scores for perception of intonation were no better than chance. These results show that taction is a viable modality to supplement a deficient auditory mode.


A shorter version of the Weiler-Hood model for loudness coding during adaptation. A graphic/algebraic model proposed by Weiler and Hood (Audiol., 1977, 16, 499-506) for loudness coding during auditory adaptation, assuming a fixed loss of loudness units for a given adaptation to any test intensity, was shown to describe several sets of adaptation data quite well. The present paper offers a more convenient algebraic formula using only the obtained post-adaptation balance level at the baseline intensity rather than a smoothed adaptation function. This shortening is at the expense of a somewhat increased influence of random fluctuations.


Directional sensitivity in cat of collicular auditory neurons to FM sound. Directional sensitivity for FM sound was compared between two types of FM sound, a linear FM and a "Step" FM digitally synthesized to contain 28 steady short tones with half-overlap in time between every successive pair, simulating the formant transitions of speech. There seemed to be no difference in the response of the cat collicular neuron in directionality of the units for ascending vs descending frequencies. As far as we have examined, no FM-sensitive neurons were observed which were specifically responsive to particular FM components in a stimulus.


A comparative study of the effect of two time-alteration techniques on listener comprehension. The purpose of this investigation was to determine if listener comprehension is differentially affected by two different techniques of time alteration: the sampling method and the harmonic compression method. The Nelson-Denny Reading Test, consisting of 8 selections of scientific and literary content appropriate for college students with respect to interest and level of difficulty, was presented to 3 groups of 40 Ss each; each group was given the tape-recorded test after processing at one of the 3 speech rates, normal, half normal, or twice normal rate. Of the 8 selections on this test, 4 were processed by sampling using a VARISPEECH-I compressor/expander, and 4 were processed by harmonic compression using a Lockheed LM-312 Pitch Normalizer. There were of course some differences in listener comprehension as a function of rate, but within each of the rate conditions there were no significant differences as a function of method of time alteration. With the type of speech material used here, and within these rate conditions, these time alteration methods can be used interchangeably in such research.


Relative intelligibility of CID spondees for normal and hearing-impaired listeners. The relative intelligibility of the 36 CID spondees presented via tape recording was found on Ss with normal hearing, and on Ss with flat and with sloping sensorineural losses (N: 15 in each group). The spondees as a group were found not to be homogeneous in intelligibility for each group and across groups. Ss with a sloping loss identified the spondees at a significantly (p less than 0.05) higher sensation level (SL) compared with the other groups. A list of 14 spondees was derived encompassing relative intelligibility within a 5-db range for clinical use with such Ss.


Distinctive features of consonantal errors in deaf children. Pictorial stimuli of 18 consonants in 3 vocalic positions were presented to 10 deaf children; verbal responses were phonetically transcribed. Consonantal substitution errors were submitted to INDSCAL analysis. A 2-dimensional solution revealed features relating mainly to place of articulation and indicated that current habilitation procedures focus primarily on those features while not exploiting others available in the speech signal.


Multiple fibrofolliculomas (Birt-Hogg-Dubé) associated with a large connective tissue nevus. Multiple follicular tumors of the type recently described by Birt and colleagues as fibrofolliculomas were observed in the dorsal skin of a white man in association with a large connective tissue nevus. No signs of systemic disease or phakomatosis were present. This type of lesions represents benign neoplasia of the fibrous root sheath of the hair follicle in association with proliferations of the infundibular portion of the outer epithelial root sheath. Its existence supports the view that the mesodermal portions of the pilar apparatus can become neoplastic, and also provides another example of the close interactions existing between the ectodermal and mesodermal components of the hair follicle.


The keratinization disorder in collodion babies evolving into lamellar ichthyosis. Its possible relevance for determining the primary defect in lamellar ichthyosis. Two collodion baby girls with disorder evolving into lamellar ichthyosis were followed by light and electron microscopy. Light microscopically, the neonatal colloidion skin was characterized by a thick compact stratum corneum which was PAS positive in its upper two thirds, by a thin stratum granulosum and by a non-acanthotic stratum spinosum with normal mitotic activity. Electron microscopically, the upper stratum corneum appeared pathological, whereas the lower part was normal except for some minor parakeratosis. The main alterations in the underlying stratum granulosum were diminished tonofibrils and keratohyalin. Biopsy specimens taken at the age of 2 weeks were typical for lamellar ichthyosis and showed hyperkeratosis with focal parakeratosis, a thickened stratum granulosum in which the cellular content of keratohyalin and tonofibrils was moderately diminished, and acanthosis with increased mitotic activity. It appears that the ultrastructural changes of the stratum granulosum, seen in lamellar ichthyosis, are already present in the collodion skin of the newborn, at a time when the epidermis does not yet show an increase in mitotic activity.


Punctate porokeratosis. A clinical variant of porokeratosis of Mibelli. Punctate porokeratosis is not usually recognized as a clinical form of porokeratosis of Mibelli. Two cases of punctate porokeratosis are presented. Other punctate lesions with similar clinical features which should be considered in the differential diagnosis are discussed.


Aggressive histological features of keratoacanthoma. Thirty-nine keratoacanthomas from 35 patients have been studied, six of which showed perineural, and one vascular, invasion. Thus far, their aggressive histological behavior has not been paralleled by a similar clinical course. However, continued close follow-up is essential.


Repair of calcaneal varus and cavus.

Repair of calcaneal varus and cavus. Calcaneal varus or calcaneal cavus alone can be readily corrected, and the surgical procedure is not technically difficult. The author states that if the four basic points he describes are followed, good results will be obtained, and the osteotomy will heal in the desired position without incident. If other osseous deformities of the foot are involved, the deformities must be considered separately and in relation to each other, and other procedures may be necessary.


The dorsoplantar technique of internal wire fixation. The dorsoplantar technique of internal wire fixation is a valuable tool in the surgeon's armamentarium of fixation techniques and it has many obvious advantages over the usual method of internal wire fixation.


The use of tourniquets in podiatric surgery--a review. The purpose, types, advantages, disadvantages, and clinical application of tourniquets is reviewed. Special emphasis is given to the pneumatic tourniquet as it is used today in podiatric surgery. A discussion of its possible complications as well as a method of using a double thigh and ankle cuff is presented.


Gangrene in the diabetic foot: its implications and consequences. Diabetic problems of the feet are not uncommon. Occasionally, these difficulties progress to the point where surgical intervention is required. A case was presented which involved a deep abscess of the foot that compromised the circulation to the toe. Ultimately, open toe amputation was necessary. The etiologic factors causing diabetic complications were presented and the importance of each was stressed. The preoperative considerations for surgical amputation and debridement were defined, as well as the possibility for successful healing.


Pigmented villonodular tenosynovitis: a case report. A case of pigmented villonodular tenosynovitis is described. The characteristics and clinical course are discussed and compared as to natural history, histopathology, pathophysiology, etiology, differential diagnosis, and treatment. The etiological factors of this entity are generally uncertain; however, this case may well be associated with a specific incident of trauma, eg., a puncture wound sustained from stepping on a nail.


Surgical excision of an os talus secundarius: a case report. Os talus secundarius is a relatively rare developmental abnormality of the talus; it is characterized by its location on the lateral aspect of the talus. This secondarily developed talus dramatically limits the range of motion of the ankle and subtalar joints. Differential diagnosis between talus secundarius and talus accessorius can usually be made radiographically. Talus secundarius secures itself to the lateral body of the talus by either a synchondrosis or synostosis and usually forms a set of articulations with the fibula, the superior lateral surface of the calcaneus, and a portion of the body of the true talus. Talus accessorius, however, is usually on the medial side of the talus and may form in the deltoid ligament. Talus accessorius is similar to the intercalary sesamoid bone between the external malleolus and the talus.


Differential diagnosis of plantar neuromas: a preliminary report. A discussion has been presented concerning etiology, diagnosis, and treatment of plantar neuromas. The surgeon should, at all times, attempt to ascertain the particular biomechanical fault which predisposed the patient to develop a neuroma, and he should attempt to correct or accommodate the underlying pathology.


Multivariate interrelationships of selected physiological and biochemical variables associated with physical fitness status. The interrelationships between selected physiological, metabolic and hormonal variables were investigated in active and sedentary middle-aged males during consecutive periods of rest, graded exercise on a bicycle ergometer, and recovery. Venous blood samples were drawn during each phase of the activity which was performed in the post-absorptive state. Data were analysed using correlational and factorial analysis techniques, and further evaluated by discriminant function procedures. Significant correlational relationships were evident among physiological, metabolic and hormonal variables, and factor analysis identified four factors at each phase of activity which accounted for as much as 69% of the common extracted variance. These factors described physiological function and hormone-metabolite behaviour during each phase of activity. Discriminant function allowed fitness classification of subjects using only the hormone-metabolite data, thus identifying specific biochemical correlates of the fitness groupings which had been established by physiological criteria alone.


Asymmetry in sister chromatids of human chromosomes. Human metaphase chromosomes show identical lateral bands in sister chromatids when stained with quinacrine mustard or with Giemsa after trypsin treatment. A hybrid of these two methods produces banding patterns that are different in sister chromatids. Homologs may have similar patterns, so that a given chromatid is more like a homologous chromatid than its sister chromatid. It is suggested that asymmetry of sister chromatids may be important in regular mitotic disjunction.


Relationship between heart rate and relative oxygen intake in male subjects aged 10 to 27 years. Regression equations relating heart rate (fh) to relative oxygen intake (% VO2max) have been calculated for bicycle ergometer exercise. The five groups of subjects were boys aged 10--11, 13--14 and 16--17 years, average young adults aged 23--27 years, and middle and long distance runners aged 20--25 years. The heart rate at a given % of VO2max was higher for younger than for older boys; however, the heart rate discrepancy between groups diminished at increasing intensities of exercise. The results are discussed in relation to the use of heart rates in training and exercise prescription. At high work loads, graphs of % maximum heart rate against % VO2max are relatively independent of age, but at the lower levels of activity common in everyday life, the % VO2max of adolescents must be predicted for age-specific regression lines.


Infantile ichthyosis in rats: a new model of hyperkeratotic skin disease. A new mutation produces neonatal thickening of the epidermis and other classical signs of hyperkeratosis. After periodic exfoliations every 4 days for the first 2 weeks of life the skin becomes clinically normal. The condition is inherited recessively and ascribed to the gene i (infantile ichthyosis) which is located in linkage group I, 36 percent recombinants away from the albino gene, a. The gene affects an unrecognized developmental process in skin that precedes the continuing normal differentiation of epidermal cells in postnatal life.


Stature and body weight growth during adolescence based on longitudinal data of Japanese children born during World War II. Longitudinal survey data of stature and body weight from age 7 to 17 were obtained for 100 boys and 100 girls during World War II. The growth rates and the average annual increments were compared with those of children born after the war. Growth attained at age 7 as a percentage of that at age 17 is larger in children of the control group, presumably as a result of an improved environment affecting the growth increment. The age at maximum velocity is six months to one year earlier for the current group of children. Although the maximum velocities for both items and sexes are nearly the same in the groups compared, the total increments are larger in the current group of children. Age, distance, and maximum velocity at adolescent growth spurt were obtained for each child. The mean values were compared according to growth patterns and growth attained at age 7. The "increasing type" growth group has the highest velocity at the greatest distance and the oldest age for stature. Children who were taller or heavier at age 7 have velocity peaks with greater distances.


A study on simultaneous symmetrical motions. Three right handed male subjects performed a simultaneous symmetical task involving the motions of reach and pressing buttons. Simultaneous performance time was investigated at several symmetical locations. The symmetrical locations were defined by the combinations of different levels of separation distance, angle and distance. Three levels of separation distance (3, 9 and 15 inches), seven levels of angle (0, 15, 30, 45, 60, 75 and 90 degrees from the frontal reference plane) and three levels of distance (6.5, 11.0 and 15.5 inches) were applied to both hands equally. It was found that separation distance, angle and distance were significant factors in simultaneous performance. The performance time was increased when the symmetrical angle region was varied from the 0--45 degrees region to the 45--90 degrees region. Specifically, the performance time was at the minimum at 15 degrees of symmetrical angle and at the maximum at 90 degrees of symmetrical angle. In addition, the performance time increased not only as the distance of the moves was increased, but also as the separation distance interval was increased (i.e., the separation distance interval varied from a 3--9 inch interval to a 9--15 inch interval).


Continued high incidence of mutants in a Peruvian population of mice. A second trapping of wild mice from two sites in a Peruvian river valley confirms the unprecedented high mutant incidence established by a previous trapping. It also shows that the population may be localized. The new mutants are different from those found in the first trapping, and thus indicate a continued source of mutagenic activity either external or within the gene pool of the population. A third study is underway.


Microwave radiation-induced chromosomal aberrations in corneal epithelium of Chinese hamsters. A microwave diathermy machine was used to irradiate the eyes of 5-month-old female Chinese hamsters. The right eye of each of seven animals was irradiated with 75 mW/cm2 radiation density for 10 minutes. After one month, slit-lamp examinations revealed lens opacities in the exposed eyes of two animals. Next, the right eye of each of 32 animals was irradiated with 100 mW/cm2 radiation density for 30, 20, 10, or 5 minutes. Epithelial cells of the cornea were collected to make chromosomal preparations. There were 0.1562, 0.0794, 0.0819, and 0.0488 chromosomal breaks per cell, respectively. No chromosomal breaks were observed in three sham-exposed animals. The percentage of abnormal cells and the number of chromosomal breaks per cell in animals that had exposures of 100 mW/cm2 radiation density for 30 minutes were higher than those in control animals. These results were statistically significant at the 5 percent level.


Circadian rhythms in some groups of Indians working in shifts. The present study was undertaken in order to find out the effect of changes of shifts on different physiological responses in Indian industrial workers. Two groups, one of 8 workers from industries and another of 6 sedentary subjects used as controls, acted as volunteers in this study. The first group worked in three different shift rotations: morning, afternoon and night. The second group worked in two shifts: day and night only. Different physiological responses, specially the pulse rate and oral temperature, were recorded hourly. The other physiological responses, such as frequency of micturition, gastro-intestinal disturbances, hours of sleep were also noted. Several days of consecutive work and recreational activities were considered in each subject. In the control group, the oral temperature rhythm did not change significantly with the change of shifts; so did the pulse rate rhythm. But this group had less sleep and higher frequency of micturition in the night shift routine than those during day shift. The typical industrial workers' oral temperature rhythm also did not change significantly with the shift changes, but their pulse rate rhythm changed slightly with shift change, possibly in an attempt to adapt. They generally slept well in all 3 shifts and had micturition equally frequent. However, there were individual variations with some peculiarities in both the groups.


The effects of unsatisfactory working conditions on the epidemiology of unauthorised absenteeism in an old textile factory in Isfahan, Iran. Comparison of unauthorised absenteeism rates were made between two large textile factories in Isfahan, Iran. The working conditions in the study factory were rather unsatisfactory, unlike the control factory. Comparison showed significantly higher rates for the study factory: the average annual duration per person was 7 days in the study factory versus 2.5 days in the control factory, and lost time percentage was 2.4% in the former versus 0.84% in the control. Inception rate of persons was 0.73 versus 0.48, and point prevalence rates 0.002 versus 0.001, whilst period prevalence rates were 0.016 versus 0.011 for the study and control factories respectively. Examination of the study factory data was made to determine any possible relationship between unauthorised absenteeism rates and age and length of employment. It was found that higher unauthorised rates were found amongst the younger workers, 100% for those age 19 and under, versus 59.6% for those age 50 and over. 9.16% of workers employed for 1--4 years took such leave against 70.14% of those employed for 10 or more years. Only 18.8% of all workers took certified sickness absenteeism and the rate increased with age. It was suggested that worker dissatisfaction toward unsatisfactory working conditions may be expressed in terms of unauthorised absenteeism. In view of the widespread consequences of such absenteeism, it is recommonded that closer attention be paid to improve the quality of working life.


A continuum theory of Allen's frontal contraction model of amoeboid pseudopodium extension. A continuum theory is proposed for the chemically controlled cytoplasmic streaming observed in pseudopodium extension in Chaos Carolinensis. Amoeboid cytoplasm is assumed to consist of submicroscopic contractile fibers bathed by viscous fluid. The fiber constituent models the actin-like and myosin-like contractile machinery known to be present in Chaos Carolinensis cytoplasm. A "trigger chemical",  produced at the pseudopodium tip, moves by diffusion in, and convection by, the viscous fluid, and causes the contractile fibers to contract in their own length. The contracting fibers, attached at the tip and running continuously back toward the amoeba cell body, pull the fluid constituent of the cytoplasm forward and ultimately crosslink to form the outer gel tube of the advancing pseudopodium. That is, streaming cytoplasm is modeled as a two constituent porous medium, with the fluid constituent free to flow through a porous matrix of oriented (contractile fiber) rods, while the matrix of rods itself moves as the fibers contract, with fiber contraction controlled by a trigger chemical born by the fluid constituent. According to this theory, in the region behind the advancing pseudopodium tip, the contractile fiber rods move forward toward the tip faster than the fluid constituent. The hydrostatic pressure in the fluid therefore increases from the cell body toward the tip (Just the opposite from flow driven by pressure excess generated in the cell body). The excess of hydrostatic pressure above ambient built up at the tip provides the force to roll out the advancing pseudopodium tip. The cell membrane plays no active mechanical role. The mathematical transcription makes a precise theory of R. D. Allen's "frontal (or fountain zone) contraction model". The general system of coupled, non-linear, partial differential equations is solved for its simplest non-trivial special case, that of a steady-state motion, as seen from a coordinate system attached to the advancing tip. Solutions exist, and, for each distinct forward speed (which is left to the discretion of the amoeba) the solution is unique. The theory predicts both upper and lower bounds for possible pseudopodium lengths.


The efficiency of mechano-chemical cycles and the mechano-chemical availability function. This paper deals with elementary thermodynamic considerations applicable to mechano-chemical cycles. It shall review concepts about the efficiency of these cycles and then suggest an extension of the concept of the Availability Function to be called the Mechano-Chemical Availability Function.


Is the 9+2 pattern of flagellar and ciliary axonemes an efficient arrangement for generating planar bending? A circlet of 9 interacting microtubular doublets generates less bending moment at low bending rates, but allows bending moment to be generated at higher bending rates, and has an energy efficiency at least 92% as great as an arrangement with all the interactions between microtubular doublets in a plane parallel to the bending plane. The axonemal arrangement has no significant effect on the shape of the normalized relationship between active shear moment and shear rate.


Chemotaxis and movement of Physarum polycephalum and its responses to some neurotransmitters and psychomimetic compounds. A method was developed for studying the effect of some neurotransmitters and drugs on the rate of movement and the chemotactic value of the plasmodium of Physarum polycephalum. Epinephrine (adrenaline) at a concentration of 1 mg/ml, reduced the rate of movement and shortened the length of the cycles of shuttle streaming, but did not affect the chemotactic response. The drugs DL-amphetamine, cannabinol and heroin diminished the rate of movement, whereas Na-barbitol misled the chemotactic response.


Tension generation by isolated myofibrils. The technique for mechanical dissection of microscopic myofibrilar bundles containing few myofibrils is described. A sensitive electrooptical tension transducer capable of resolving the tension generated by such myofibrilar bundles to within a fraction of a percent is used to study the response of the preparations to low ATP concentrations. The rate of tension development decreased with a decrease in ATP concentration. Below 10(-6) M ATP the myofibrils did not demonstrate any mechanical activity at all. These findings are discussed in terms of the kinetics of the cross-bridge cycle.


Computer simulation of flagellar movement. V. oscillation of cross-bridge models with an ATP-concentration-dependent rate function. A stochastic computational method developed for analysis of two-state cross-bridge models was extended and used to compute the oscillatory movement generated by three-state cross-bridge models containing a rate function proportional to ATP concentration. Only one of the possible three-state models appears satisfactory; with this model, the frequency of oscillation, at constant amplitude, responds to changes in both ATP concentration and viscosity in the same way as real flagella. In this model, ATP binding causes cross-bridge detachment, which is rate limiting at low ATP concentrations; while at high ATP concentrations a transition between two attached states limits the rate of cross-bridge detachment. Since this model agrees with observations on actomyosin ATPase kinetics, the data on flagellar oscillation frequency support the idea that the movement-generating mechanisms of flagella and muscle are similar.


Numerical study of the behavior of an activation parameter in a sliding filament cat papillary muscle model. A previously existing model of cross-bridge kinetics is modified to make it applicable to cardiac muscle and incorporated into a macroscopic model of isolated heart muscle. Equations are formulated which describe the responses of this model during simulated isometric and isotonic contractions. These equations allow one to calculate the time variation of the activation parameter in the model when given the contraction time history, i.e. the time course of length and tension changes. The activation parameter is defined as the instantaneous rate constant for cross bridge attachment. We calculate the time course of the activation parameter with the model's responses set equal to the measured responses of isolated cat papillary muscle and the model parameters chosen appropriately for cat papillary muscle. It is found that in order for the model and muscle response to match, the degree of activation of the muscle model must first increase and then decrease with shortening. The behavior of the activation parameter in the muscle model is consistent with physiological investigations which suggest that shortening in cardiac muscle is associated with both activation and deactivation.


Gliding edge dislocations and flipping in the conformational change of helical proteins. The general problem of transconformation of one helical form of protein to another is considered from a topological point of view. A notation is presented which reflects the topology of the bonding. Any helix belongs to one of two geometrical classes, the positive and negative classes. The fundamental mechanism of transconformation between helices of the same class is the edge dislocation. It has two limiting modes of propagation: glide and climb. The first appears as a caterpillar-like wave of slip that travels along the peptide chain. If the second occurs then it would be the vehicle of change in number of peptide chains. The fundamental mechanism of transconformation between molecules of opposite classes is a process we call flipping, which also probably travels as a wave. Examples of transconformation including alpha DL leads to pi 4 DL in poly-gamma-benzyl-glutamate and alpha leads to beta in keratin, are discussed.


A kinetic study of muscular contractions. In the present work the kinetics of muscular contractions are studied, based on a three-state model which is introduced in Section I. The general properties of this class of models for muscular contractions are derived in Sections II-VI. The kinetic equations are solved for four particular examples in Sections VII-X. These analytical results should be useful for comparison with experimental data to determine the functional dependence of the rate contants alpha and beta on muscle length.


Local consideration of polymorphisms for populations coexisting in stable ecosystems. The stability problem for multiallelic genetic polymorphisms for n populations coexisting in stable ecosystems is considered. Taking into account only density-dependent interactions a generalization of Fisher's theorem is obtained. Specifically, the average fitness of a population must be locally maximized subject to the constraint that the equilibrium population sizes are fixed if the polymorphism is stable. Further, the quasi-equilibrium population sizes Ni corresponding to fixing the genetic structure of all populations in the ecosystem at various values have extrema at the equilibrium point. Such an equilibrium can be a maximum, minimum or saddle point depending upon the type of ecosystem under consideration. A simple test separating these cases on the basis of the so-called ecosystem matrix is suggested. The general equilibrium problem is reformulated as a maximization problem under some restrictions. Conditions under which the maximized function can be expressed as sigma ni=1 Ni are formulated.


An explicit formula for frequency changes in genetic algebras. A general situation in population genetics is considered with any hereditary system described by a genetic algebra. It is assumed that there is random mating, no selection, and infinite population size. A formula is derived for the distribution of genetic types in the general jth generation given the distribution in the initial generation. Special attention is paid to the case of one locus with polyploidy and chromosome segregation. The calculations are carried out as far as possible in the situation with triploid gametes.


Comments on lack of interference in the four strand model of crossing over. Assuming a four strand model and no chromatid interference, lack of chiasma interference is known to be equivalent to the assumption that the formation of chiasmata follows a Poisson process. We prove the lack of chiasma interference is also equivalent to the assumption that a random gamete shows recombination on any given interval of a chromosome independently of recombination on all disjoint intervals. Both assumptions are sufficient, but not necessary, for Haldane's formula relating recombination to map distance to be true, as we demonstrate by specific counterexamples. These issues are discussed in the context of the theory of stochastic point processes.


Migration and mutation in stochastic models of gene frequency change. I. The island model. Migration has in the past been introduced deterministically into stochastic gene frequency models. Migration at rate m then reduces the between-population variability by a factor of (1 - m)2 each generation. We show that with stochastic migration, whether of fixed or variable numbers of individuals, a positive term delta m is added to the variance. As a result of the delta m term, the equilibrium value of the between-population variability is increased compared to the corresponding value for deterministic migration by a factor of approximately (1 - m)-2 for small m. An equivalent result is derived for mutation, using the infinite allele model for a single population. We show in addition that these results may be derived much more simply by use of identity-by-descent probability methods, but only if a modified definition of the probability of identity-by-descent is used, involving the sampling with instead of without replacement of pairs of genes from the population.


A formulation of the lifetime distribution and the existence of its moments. The lifetime distribution is formulated in terms of g(t), defined as the ratio of the hazard function to the tail probability function, to study the properties of the lifetime distribution. A criterion is provided for the asymptotic behaviour of g(t) and the hazard function. Criteria for the existence and non-existence of the moments of any probability distribution of a non-negative random variable are obtained in terms of the derivatives of g(t). Examples are given to illustrate the use of the criteria and applications made to stochastic models of population growth as well as other lifetime distributions.


Electrical properties of phasic and tonic muscle fibres of the abdominal flexor muscles in crayfish. Phasic and tonic abdominal flexor muscle fibres of two anatomically different muscles in the crayfish Procambarus clarkii or Astacus sp. were investigated using electrophysiological techniques. 1. In phasic muscle, fibres were electrically coupled. They were very tightly packed and could not be isolated. No coupling was observed in tonic fibres where single fibres could easily be isolated and their radii determined with precision to between 75 and 200 micron. 2. The electrical constants of phasic fibres (sarcomere length about 2.5 micron) were determined according to the "infinite" cable theory. The were : lambda = 0.5-1 mm, Ro = 30-40 k omega, Rm = 20-30 omega.cm2, Ri = 2-5 omega.cm and Cm = 3-4 microF/cm2. 3. In tonic fibres (sarcomere length about 8 micron) electrical constants were determined according to the equations for the "short cable". They differed considerably from one fibre to another : lambda ranged between 1.5-12 mm, Ro 0.15-1.6 M omega, Rm 700-1,100 omega.cm2, Ri 25-150 omega.cm and Cm 15-300 microF/cm2. 4. The current voltage relationship was linear in phasic fibres for both outward and inward currents not exceeding 0.75 microA. In tonic fibres there was a delayed rectification in about 95% of fibres; anomalous rectification and generation of spikes were found in about 5% of the fibres. 5. In tonic fibres, a strong hyperpolarizing pulse produced a delayed inward rectification followed by prolonged after-depolarization. The addition of TEA to the bathing medium diminished this rectification and abolished the after-depolarization; therefore, K+ ions seem to be involved in this phenomena.


[Relationship between cortisol metabolic clearance rate and cortisol concentrations in adult male dexamethasone treated guinea-pigs (author's transl)]. Continuous infusion of increasing unlabelled cortisol concentrations and tritiated cortisol was used to state precisely the relation between metabolic clearance rate of cortisol (MCR) and blood cortisol levels, on conscious male adult guinea-pigs under chronic cannulation and treated by dexamethasone. The MCR of cortisol depends on blood cortisol levels : constant for low values of cortisol concentrations (5 and 20 micrograms/100 ml), it rises 50 % between 20 and 50 micrograms/100 ml : from cortisol levels of 50 to 300 micrograms/100 ml, it reaches a maximala and constant value.


[Activity of vagal efferent fibres innervating the smooth muscle of the dog's cardia]. Our experiments were performed on dogs in which the central end of the left thoracic vagus had been sutured to the peripheral end of the left phrenic nerve. In such preparations, the activity of motor units of the re-innervated left hemidiaphragm indicated the activity of the vagal efferent fibres. After the left hemidiaphragm had been transformed into subcutaneous muscle, we studied, (using electromyography in the unanesthetized dog), the discharge of vagal fibres which originally supplied the lower oesophageal sphincter (cardia). The present paper only deals with fibres showing low frequency tonic discharge. 1. For some fibres (VIC type ; N = 42), the spontaneous firing rate (1.5 less than f less than 4.5 spikes/s) is suddenly enhanced just after the buccopharyngeal stage of swallowing (12 less than f less than 16 spikes/s). The this discharge stops abruptly just before the end of oesophageal peristalsis and starts again 2 to 3 seconds later at a low frequency (15 less than f less than 4.5 spikes/s). 2. Other fibres (VEC ; N = 18), which also have a slow discharge frequency (1 less than f less than 3 spikes/s) stop firing soon after the onset of swallowing and remain silent until the end of oesophageal peristalsis. At this time, i.e. when the bolus enters the stomach, the discharge starts again with an increased frequency (5 less than mean frequency less than 9 spikes/s). 3. The behaviour of the tonic vagal fibres during swallowing, as well as their low discharge frequency, strongly suggest that these fibres originally controlled the smooth muscle of the lower oesophageal sphincter and excited either an inhibitory (VIC = vagal inhibitory fibres of cardia) or an excitatory control (VEC = vagal excitatory fibres of cardia) upon this area.


[Effects of isoproteic and lipid rich diets on lipase, phospholipase A2, cholesterolesterase, trypsin and amylase activities in rat pancreatic juice and pancreas (author's transl)]. Isoproteic and lipid-rich diets containing about 15 or 20 % of sun flower triglyceride or soya phospholipids given to rats for 8 weeks were observed to increase lipase, phospholipase A2 and trypsin synthesis in the pancreas phospholipase A2 and trypsin synthesis in the pancreas and the activities of these enzymes in the pancreatic juice (Tables IV, V). Smaller effects are observed after 15 day administration of diets containing 40 % of triglycerids or phospholipids ; these diets decreased the ADN content of pancreas.


The many faces of sarcoidosis.

The many faces of sarcoidosis. This is a radiographic exhibit demonstrating some of the many ways that pulmonary sarcoidosis can present. In addition to the classical stages (I-IV), sarcoidosis can sometimes present atypically. Some of these forms of sarcoid disease have been included in this exhibit.


Reflections on short-term psychiatric hospitalization for children and adolescents. The functions and operations of a short-term psychiatric inpatient unit for children and adolescents are discussed. Staffing pattern, programming, and statistical data are reviewed. The author concludes that short-term inpatient treatment has much to offer when complemented by careful research and evaluation.


Technique of locoregional irradiation in breast cancer. In medicine, one modality of treatment cannot be replaced by another unless the new method is equal, if not superior, to the existing one. Currently, much is heard about using irradiation alone for the treatment of early breast cancer. Uniform irradiation of the breast, underlying chest wall, and the regional lymph nodes is a complex procedure and unless done properly, a geographical miss of the tumor and/or unnecessary irradiation of adjacent normal structures can occur, leading to inferiority of the treatment method.


Pattern of leukocyte counts in untreated Burkitt's lymphoma patients in Ibadan. Leukocyte counts and body temperature were studied in 232 untreated Burkitt's lymphoma patients. Differential counts were obtained in 153 of them. There was no significant diagnostic variation in circulating leukocyte levels and no correlation between the size, site, or stage of the tumour and leukocyte counts or body temperature. No explanation can be given for low neutrophils in 40 of the 153 patients whose differential counts were performed.


Edwardsiella tarda associated with osteomyelitis. A case of osteomyelitis associated with Edwardsiella tarda is reported. Specimens from a wound exudate of a 58-year-old female with osteomyelitis revealed on a direct gram-stained smear, pleomorphic, gram-negative rods. Growth of the organism on differential media and analysis of its Analytab (API)(*) patterns produced results consistent with E. tarda. The identification of the organism was confirmed by the Center for Disease Control, Atlanta. This represents the first reported case of a wound infection attributable to this organism.


Depression in the aged: dynamics and treatment. Depression is one of the common threats to the mental health of the aged. The chief cause is the interiorization of the personality and the growth of inferiority feelings due to poor adjustment to retirement, widowhood, and/or chronic physical conditions. Psychotherapy for geriatric depression can be done by a primary care physician. Specific guidelines are given for the use of psychotherapy, psychotropics, and electroconvulsive therapy (ECT) with aged patients suffering from depression in conjunction with various complications (suicidal risk, chronic brain syndrome, hypochondriasis, and paranoia).


Exercise and heart disease.

Exercise and heart disease. The role of exercise (particularly distance running) in the prevention of coronary heart disease is discussed. Evidence is presented that the ability to perform an activity requiring the most extreme degree of physical stamina is no guarantee of a healthy heart or protection from a fatal myocardial infarct. A plea is made for correction or elimination of all coronary risk factors rather than focusing on one or a few which some regard as more important than the others.


Pillotinas and hollandinas: distribution and behaviour of large spirochaetes symbiotic in termites. Pillotina spirochaetes have been observed in the hindguts of wood-eating cockroaches (Cryptocercus punctulatus), and in 25 out of 28 species of termites examined. They were especially abundant in 21 species of dry wood termites of the family Kalotermitidae, from Europe, North America and Australia. These included many species of Kalotermes and one or a few of the following: Glyptotermes, Bifidotermes, Neotermes, Ceratokalotermes, Paraneotermes, Cryptotermes, Porotermes, Marginitermes, Pterotermes, Zootermopsis, Reticulitermes, Coptotermes, Heterotermes, and nasutitermitids. Identifications of pillotinas were made on the basis of large size (0.5--2 micromtere in diameter, 50 to greater than 100 micrometers in length) and wave pattern; these were verified by electron microscopy in K. schwarzi, Pterotermes occidentis and others. Pillotinas were also present in all species of subterranean termites (Family Rhinotermitidae) examined, and in the most primitive Australian termite, Mastotermes darwiniensis (Family Mastotermitidae). They were not observed in damp wood termites (Family Hodotermidiae). Pillotinas are invariably associated with a rich, complex xylophagous microbial community composed primarily of motile prokaryotes, and hypermastigote and polymastigote flagellates. Some have been previously described by those primarily concerned with termite hindgut protozoa. Observations were made on their modes of behaviour, division, and microbial associates. A new genus of spirochaetes, Hollandina, is also described. It is distinguished from Pillotina by a smaller size and several ultrastructural features, but is otherwise closely related taxonomically. Evidence is provided to support Hollande and Gharagozlou's (1967) concept that the pillotinas and hollandinas deserve the taxonomic status of 'family' and that they should be classified with the cristispire siprochaetes a-cording to the scheme developed by Hovind-Hougen (1976). Spirochaetes are treated as a Phylum of the Kingdom Monera (Prokaryota) in the five kingdom system of Whittaker (1969).


Flow microcalorimetric investigation of yeast growth in a complex medium. The growth of Kluyveromyces fragilis in a complex medium under anaerobic and aerobic growth conditions has been conducted using a flow microcalorimeter. Growth under defined conditions is characterized by an initial exponential rise in heat output rate to a maximum, followed by a decline to a baseline deflection. Inadequate oxygenation can result in a more structured thermogram. The results are used to illustrate the deficiencies of some calorimetric incubations, and observations reported by other authors are critically discussed.


Potential health effects of chlorine dioxide as a disinfectant in potable water supplies. Chlorination of potable water supplies high in organics may yield carcinogenic compounds such as trihalomethanes. Chlorine dioxide has been proposed as an alternative disinfectant to chlorine. However, chlorine dioxide is a strong oxidant that forms significant amounts of chlorite when added to potable water supplies, and chlorite is similar to nitrite in its molecular structure and may be similar in its mechanism of methemoglobin production. Nitrites and chlorites are thought to act synergistically to produce MetHb. Neonates and persons with G-*-PD deficiency are likely to be unusually susceptible to MetHb formation from these compounds because their red cells lack the metabolic machinery to adequately protect against oxidant stress. Since male blacks represent the largest population in the U.S. to be G-6PD deficient, Black male neonates may represent the group at highest risk to the use of chlorine dioxide as a disinfectant in the nations water supplies.


Ultraviolet radiation and skin cancer in mice and men: accumulation of effect and uncertainty of prediction. Studies on mice exposed to repeated doses of UVR (35 yr ago) and recent epidemiologic investigations and measurements of carcinogenic radiation on patients with nonmelanoma skin cancer showed that repeated doses accumulated. The effects of factors such as genetics, human behavior, kind of skin, variation in intensity of sunlight, etc., cannot be ecaluated quantitatively because of uncertainty. The possibility of inherent indeterminancy must be kep in mind in the study of effects of sunlight.


Photoreactivation: evaluation of pyrimidine dimers in ultraviolet radiation-induced cell transformation. The PRE repairs DNA by the specific and exclusive monomerization of pyrimidine dimers. Photoreactivation thus provides an analytical test for determining the role of pyrimidine dimers in UV damage to biologic systems. We have shown the first UV transformation of cultured human cells (judged by ability to grow in soft agar). Preliminary results indicate that 1) lesions leading to cell transformation are subject to photoreactivation and 2) pyrimidine dimers may well be important in solar carcinogenesis.


Inhibition of skin carcinogenesis in vivo by caffeine and other agents. The induction of skin cancer in mice of the Swiss (Carshalton) strain, by repeated irradiation with UV-light, was strikingly reduced by the local application of caffeine prior to each exposure. Theophylline displayed the same activity. These two substances have been selected as probable inhibitors of error-prone, postreplicative DNA repair. Conversely, reductone and chloroquine, which are considered as inhibitors of the error-free, prereplicative excision repair, did not modify the incidence of the tumors. Special emphasis has been given to the histologic behavior of radiolabeled caffeine in the normal and UV-irradiated epidermis of the mouse in vivo and to the ability of mouse epidermal cells in vitro to repair DNA after UV irradiation.


Influence of heat, wind, and humidity on ultraviolet radiation injury. We investigated the influence of heat, wind, and humidity on UVR-induced acute and chronic skin damage of experimental animals housed in environmental chambers and irradiated under controlled conditions. Hairless mice (strain HRS/J) irradiated after an increase of 10 degrees F in skin temperature had more skin damage than irradiated controls. Significantly more Swiss albino mice irradiated for 400 days while maintained at 90 degrees F developed tumors than did those receiving the same amount of UVR but maintained at room temperature. Mice exposed to UVR daily for 4 weeks while kept in wind of 7 mph had greater damage and slower recovery than animals irradiated but protected from wind. Wind also accelerated tumorigenesis in mice than received chronic UVR. Mice kept at 80% relative humidity and given a single dose of UVR had greater skin injury than animals irradiated while at 5% relative humidity. High midity also appears to accelerate skin cancer formation in animals that were exposed to chronic UVR.


Skin cancer epidemiology: research needs. The basis data currently being used to estimate and evaluate the dose-response relationship of UV-B and skin cancer are from a 6-month survey for four areas that participated in the TNCS, 1971-1972. Although most investigators from various fields of interest outside of cancer research, i.e. aviation, environmental ecology, physics, chemistry, and photobiology, etc., may admit an association between nonmelanoma skin cancer and UV-B exists, they point out that 1) the epidemiologic data currently available are too sparse and lack certain detail, such as exposure patterns and skin types, and 2) more data of this type are needed over a broad geographical range to allow for more precise measurements of the effects of stratospheric ozone depletion. They argue that the present relationships could change drastically with the addition even of a few more points (geographical locations) and that location-specific and demographic factors should be evaluated. Therefore, these data need to be updated and expanded to include more locations over a longer study period. The National Cancer Institute and the Environmental Protection Agency undertook a special skin cancer study from June 1, 1977 to May 31, 1978. The objectives of this study were: 1) to determine the incidence of nonmelanoma skin cancer (basal cell and squamous cell carcinomas) in various population groups within the United States, and 2) to ascertain and measure epidemiologic factors that may contribute toward the excess risk of nonmelanoma skin cancer in specific population groups.


Immunologic aspects of tumor induction by ultraviolet radiation. Chronic treatment of mice with UVR not only induced skin cancer but also produced a systemic change that interfered with host resistance against these tumors. The studies leading to the this conclusion were prompted by the discovery that most tumors induced in C3H mice by chronic UV irradiation were immunologically rejected following transplatation to normal syngeneic recipients. This raised the question of why these tumors were able to grow progressively in the autochthonous host without being destroyed immunologically. We found that after a short course of UV treatment, the UV-irradiated mice lost their ability to reject transplanted UV-irradiated mice lost their ability to reject transplanted UV-induced tumors, even though such transplants were rejected by unirradiated animals. The growth of the transplanted tumors in UV-treated mice resulted from a systemic alteration in the animals that was induced by UV irradiation of the skin.


A systemic effect of ultraviolet irradiation and its relationship to tumor immunity. Chronic irradiation of mice with UV light produces a systemic alteration that is immunologic in nature and may be due to the presence of specific suppressor lymphoid cells. The immunologic aspect of this systemic alteration was demonstrated by cell transfer experiments. Lymphoid cells from UV-treated donors were unable to confer tumor resistance to lethally X-irradiated and neonatal liver reconstituted recipients, whereas recipients given lymphoid cells from normal donors were resistant to a challenge with a syngeneic UV-induced tumor. Therefore, lymphoid cells from normal donors could mediate tumor rejection, but lymphoid cell from UV-irradiated donors could not. Furthermore, lymphoid cells from UV-treated donors suppressed the ability of lymphoid cells from normal donors to mediate syngeneic tumor rejection when mixed 1:1 before transfer into lethally X-irradiated recipients. This suppression was specific since all recipients recipients resisted an allogeneic UV-induced tumor challenge. Serum transfer experiments failed to demonstrate any inactivating or suppressive substances in the serum of UV-treated animals. The findings suggested that UV-treated mice failed to reject UV-induced tumors because UV irradiation induced specific suppressor lymphoid cells that prevented the development of an immune respons against these tumor antigens.


Recommendations for future research on ultraviolet radiation carcinogenesis. Recommendations for future research on photocarcinogenesis were developed during an international conference on UVR carcinogenesis. Areas covered in the recommendations include research at the molecular biology level, human (especially epidemiologic aspects), physical (including instrumentation), and biologic studies (stressing animal models). The recommendations also propose the establishment of central supply and service sources for photocarcinogenesis research as well as the establishment of interdiscipilinary training programs related to research in photocarcinogenesis.


Action spectrum for ultraviolet carcinogenesis. Previous observations and experiments have shown that the potent carcinogenic wavelengths for skin cancer in man are found in the 290- to 320-nm range, although shorter and longer wavelengths can also have an effect. The short wavelength limit (290 nm) is determined by thesolar emission reaching the earth's surface, a parameter that varies greatly with season, time, and atmopheric conditions. The long wavelength limit (320 nm) was based on observations of the effect of window glass filtration and on comparison of the effect of mid and long UV radiation. It provide little information as to the efficacy of wavelengths in this range. We performed a series of experiments to provide more specific comparative data by testing the hypothesis that the action spectrum for carcinogenesis parallel that for erythema. Albino mice were exposed the emission of a diffraction grating monochromator (5 nm half power bandwidth) at 290, 300, 310, and 320 nm. Energy levels were proportional to valves for the erythema spectrum of untanned Caucasian human skin. Exposures were given thrice weekly until 50% of the mice had developed tumors. Squamous cell carcinomas developed at approximately the same rate and frequency when the UV exposure was proportional to that for erythema, which indicated a decreasing potency from 300 to 310 to 320 nm. No tumors occurred in mice exposed to 290 nm.


Experimental ultraviolet photocarcinogenesis: wavelength interactions and time-dose relationships. Tumors were induced in the skin of SKH hairless mice by exposure to fluorescent FS sun lamps or to a long-arc xenon solar simulator. Tumores developed about equally well with varying amounts of UV-A radiation (lambda greater than 320 nm) given simultaneously. In contrast, incremental changes in the UV-B region (lambda less than 320 nm) led to substantial increases in carcinogenic effectiveness. A tumor-"initiating" dose of UV-B (4-10 wk of daily FS lamp exposures) was rendered less effective by subsequent exposures of the mice to UV-A (6 hr/day, F-40 T12BL lamps). The mechanism for this effect is not known. Most tumors induced by a short course (10 wk) of FS lamp exposure grew slowly or regressed, whereas mice exposed for a longer period (30 wk) developed more tumors, and many of those that appeared early grew aggressively. Effects of daily dose fractionation were less clear, and the subject requires further study. These and other variables are being tested in a program designed to yield useful information on the effects of changing spectrum, dose, and dose delivery rates on sunlight-induced cancer.


Photosensitized reactions and carcinogenesis. We present data from experiments designed to investigate the role of DNA interstrand cross-links induced by exposure to 8-MOP plus UVR and skin carcinogenesis. 8-MOP was administered topically to two strains of hairless mice, SKH:hairless-1 and HRS/J/An1, which were then exposed to UV light sources with emission in the range of 1) 300-400, 2) 320-400, and 3) predominantly 365 nm. We found no strain dependency for DNA cross-link production, but a marked strain-dependent difference in tumor susceptibility was noted. Only a small strain-dependent difference occurred in tumor incidence when TPA was administered after exposure to 8-MOP and 320-400 nm. These results suggest that the events concerned with tumor promotion are dependent on strain. Because the most effective tumorigenic wavelength spectrum was 300-400 nm, we investigated the possibility of interaction between lesions induced by the 300- to 320-nm wavelengths and the psoralen photoadducts. In the course of this experiment, we found that the tumorigenic effect was also dependent on the time interval between exposures to 8-MOP plus 365-nm light.