The physiopathogenetic basis for the angiographic diagnosis of bacterial infections of the brain and its coverings in children. I. Leptomeningitis. This is a descriptive analysis of the angiographic characteristics of leptomeningeal infections in 36 children and a correlation of these angiographic observations with anatomopathologic changes. Vascular, meningeal and parenchymal changes are described and discussed. In the normal situation, tracer protein particles injected into the subarachnoid space perfuse easily through the extracellular spaces but stop at the outer continuous arachnoidal layer. The parenchymal layer, pia-arachnoid, on the other hand, consists of a uni or pluricellular layer which is regularly crossed by tracer particles. Though the internal carotid, vertebral and basilar arteries have some anatomical characteristics: thinner tunica media and adventitia, the absence of vasa vasorum and the presence of a fluid cushion (CSF) in which they are bathed. The most striking angiographic observation in leptomeningitis is the transmural extravasation of the contrast meding 'halo' formation. Long after the cerebral circulation time, one may identify contrast media 'pooling' within the cisterns and sulci.


Experimental progressive hydrocephalus in the young animal. 22 puppies with kaolin-induced hydrocephalus were repeatedly studied for 4 months in respect to their head size, ventricular size, pressure and cerebrospinal fluid (CSF) dynamics. The intraventricular pressure was markedly elevated during the first week and dropped towards the end of the first month of the hydrocephalic process. It then escalated and again returned to normal values after 3--4 months. Formation of CSF increased with age until it reached adult values of 0.049 ml/min at the age of 3 months. Absorption rates were very low initially. The absorptive capacity surpassed formation in the puppies which survived to the fourth month of the process. Ventricular size and rate of head enlargement correlated inversely with thickness of the skull. In the surviving puppies (4 out of 22) the hydrocephalic process seemed to have arrested.


Problems of diagnosis and treatment in the Dandy-Walker syndrome. 10 children with Dandy-Walker syndrome are presented to discuss their clinical assessment and therapy. The presence on physical examination of a large posterior fossa was the most reliable clinical finding and was diagnostic in 9 out of the 10 patients. The different diagnostic confirmatory studies are discussed. The most satisfactory treatment in this series was the combination of a shunt from the lateral ventricle and the posterior fossa to the peritoneum.


Brain tumors in childhood.

Brain tumors in childhood. A review of the pathology of 689 neuroectodermal tumors occurring over a 30-year period at The Hospital for Sick Children in Toronto has underlined the importance of examining the tissue from each tumor in order to insure consistency and accuracy in histological diagnosis. The age, sex, histology and topographical distribution of this series of tumors is compared with other series and discussed in detail. The high proportion of tumors occurring in early childhood, the striking male preponderance, and the high incidence of astrocytomas, medulloblastomas and ependymomas is emphasized.


Ventriculopleural shunting in the management of hydrocephalus. 6 cases of ventriculopleural shunting for control of hydrocephalus are presented. In the other child and adult, drainage of cerebrospinal fluid into the pleural cavity seems to be well tolerated in exceptional circumstances where other shunt procedures, including intracranial shunts, are contraindicated. In the infant and young child, accumulation of fluid in the pleural space is enchanced by a poorly understood immune-related mechanism and may lead to significant pulmonary dysfunction. On the basis of our experience, this procedure appears contraindicated in this age-group.


Computed tomography of Sturge-Weber disease. Findings in computed tomography (CT) with or without contrast infusion were analyzed in 8 patients with Sturge-Weber disease. From the extent of calcification in the CT, Sturge-Weber disease can be classified into two types, localized and diffuse. The extent of calcification or cortical atrophy is predictable, if it can be shown that enhanced areas in contrast infusion CT truly represent leptomeningeal angiomatosis. Thus, using enhanced CT, the capacity of prediciton as to whether the patient will have a localized or diffuse type of disease will be possible with further observations.


Cerebral medulloepithelioma. Report of a case with multiple divergent neuroepithelial differentiation. A cerebral medulloepithelioma, a rare embryonal multipotential central neuroepithelial neoplasm of childhood, is described, bringing to 16 the total number of cases reported in the literature. It is the first example recorded to date which displayed the entire range of differentiation from embryonal to mature cells, of both glial and neuronal lineage (i.e., primitive medullary epithelium, spongioblasts, astrocytes, oligodendroglia, ependymal cells, neuroblasts, and mature ganglion cells). The significance of this tumor as a paradigm of multipotential divergent neuroepithelial differentiation is discussed.


Two levels of inferential behavior in young children. 5- and 6-year-old children made inferences about the spatial locations of animals and people in a series of 3 experiments. The tasks employed manipulable models to represent the spatial relations involved and were made as simple as possible. 2 levels of inferential behavior were found. The first constituted the ability to draw an inference consistent with information given, but with minimal understanding of the way in which inferences can assist in decisions between alternative outcomes. At the second level, children succeeded in discriminating inferences which were logically necessary from those which were merely consistent with the premises. Most 5-year-olds were at the first level, most 6-year-olds at the second level. 2 criteria for the identification of young children's behavior as inferential were established, and the results of the present study were discussed in terms of recent related work with both younger and older children.


Changes with age in measures of processing efficiency. Children of 3 ages (8, 10, and 12 years) and adults were asked to decide rapidly whether 2 line drawings were same or different based on either physical appearance (physical match) or name information (name match). Reaction times were used to estimate several temporal measures of information-processing efficiency, such as the difference between different and same judgments, the difference between name-match and physical-match judgments, and 2 types of interference. Different judgments required more time than same judgments for children but not for adults, and the difference between these decreased with age. As expected, name judgments required more time than physical judgments, but the difference did not decrease regularly with age. Interference in name-match decisions due to conflicting and irrelevant physical information decreased with age; however, interference in physical-match judgments due to conflicting and irrelevant name information does not decline with age and was a significant factor in the performance of older children and adults. The results underscore the complex character of developmental change in processing efficiency.


Linguistic experience and phonemic perception in infancy: a crosslinguistic study. English- and Spanish-learning infants were tested for perception of 2 synthetic speech contrasts differing in voice onset time. The 2 pairs were chosen so that they were native to either Spanish or English. Using the Visually Reinforced Infant Speech Discrimination (VRISD) paradigm, 6--8-month-old infants were taught to respond to a change in auditory stimuli with a headturn. Correct headturns were reinforced by the activation of a lighted animated toy. While Spanish-learning infants provided evidence of discriminating both English and Spanish contrasts, English-learning infants only provided evidence of discriminating their native contrast. The results are discussed in terms of the role of linguistic experience in the development of speech perception skills in infancy.


A conditioning analysis of infant long-term memory. The long-term retention of conditioned operant footkicks by 3-month-old infants was assessed in 2 studies. In both, infants were trained in a conjugate reinforcement paradigm in which footkicks produced conjugate activation of the components of an overhead crib mobile. After 2 training sessions, retention (cued recall, savings) was assessed cross-sectionally in a third session scheduled after varying intervals. In experiment 1, 32 infants were tested after intervals of 48, 72, 96, or 120 hours; in experiment 2, 24 infants were tested after 96, 144, 192, or 336 hours. No evidence of forgetting was observed for as long as 192 hours following original training. Although both retention measures indicated a significant memory deficit in the group tested after 336 hours (2 weeks), some individuals continued to exhibit substantial recall and savings after this retention interval. A conditioning analysis was viewed as a logical means by which to bridge the gap between animal and adult human models of memory.


Developmental relations between notational counting and number conservation. The 2 studies of this report sought to determine the developmental relationship between the child's use of counting as a notational symbol system to extract, compare, and reproduce numerical information and the development of number conservation. In study 1, children between 4 and 6 years of age were administered notational-counting and number-conservation tasks. Analysis of children's profiles across tasks indicated that children develop quantitative counting strategies (but do not necessarily count accurately) before they develop number-conservation concepts. In study 2, the generality of this sequence was tested. A population of 7- to 9-year-old "learning-disabled" children who reportedly were developing atypical counting skills were administered notational-counting and number-conservation tasks. All of these children who conserved number also used quantitative counting strategies, although some of these children frequently counted arrays inaccurately. The significance of these findings is discussed with respect to existing models of counting/number-conservation relations, and an alternative formulation is suggested based upon the new findings.


Visual and cardiac responses to animate and inanimate faces by young term and preterm infants. Infants' looking and looking-away behaviors, as well as cardiac responses to mothers' spontaneous and imitative and to dolls' animated and still faces, were recorded for 18 term and 18 preterm infants when they were 3 months old. Infants spent less time looking at their mothers' than at the doll's faces, and their heart-rate levels were elevated while looking at mothers' faces. These effects were most pronounced for the preterm infants whose inferior scores on the animate visual item of the Brazelton neonatal scale suggested a continuity of visual inattentiveness to animate stimuli. Both groups also looked at the inanimate more than the animate doll's face and evidenced lower heart-rate levels during that situation. An information-processing/arousal-modulation interpretation was made for infant looking-away behavior and elevated heart rate during the more arousing mother's-face situations.


Children's imitations of lexical items.

Children's imitations of lexical items. 3 experiments are reported in which the role of imitation in the acquisition of certain lexical items and factors influencing children's tendency to imitate these lexical items were examined. Imitation did not appear to facilitate the subsequent spontaneous use of lexical items. However, children's tendency to imitate lexical items appeared to be influenced by the novelty of the lexical item and its referent, the informativeness of the referent in the situation, and the lexical orientation of the children. The results are consistent with the interpretation that children's imitations involve the use of a supplied and previously unavailable lexical item under circumstances where lexical usage is highly probable.


Physiological, social, and behavioral consequences of crowding on children and adolescents. The present investigation was designed to examine systematically the effects of short-term crowding, involving close physical proximity, on children and adolescents. Fourth-, eighth-, and eleventh-grade children participated in groups of 4 under high or moderate spatial density conditions. During exposure to these conditions, physiological responses were measured, and following this experience children engaged in a cooperation-competition activity and provided self-reports related to their participation. Results demonstrated that crowding had physiological, behavioral and social consequences for the children studied. Across all grade levels, males in particular were more affected by short-term crowding, displaying the highest elevations in stress-related arousal. Following exposure to the crowding conditions, children were more competitive, despite the fact that they had all to gain from cooperating and nothing to lose. Furthermore, children reported having felt crowded, tense, annoyed, and uncomfortable as a function of the close physical proximity to others. Implications of the immediate and residual effects of crowding on the behavior and functioning of children are discussed.


Developmental trends in eating rates of normal and overweight preschool children. Eating rates (bites per interval) and other meal behaviors (number of chews, sips, talks with a neighbor, and chews per bite) were observed for 30 normal and 30 overweight white preschool children in their school cafeterias. Children were classified according to weight (overweight or normal), age (1 1/2--2 years, 3--4 years, or 5--6 years) and sex. Analysis of variance revealed that overweight preschool children demonstrated a somewhat higher rate of distinctly fewer chews per bite. Boys showed increasing chew rates with increasing age. Talk rates also increased with age but were unrelated to sex or weight status. Sip rates were not significantly associated with age, sex, or weight status. These results support the hypothesis that overweight persons are characterized by an increased eating rate and show that it is apparent even around the time of first self-feeding.


The interactions of normal and hyperactive children with their mothers in free play and structured tasks. Groups of 20 normal and 20 hyperactive boys ranging in age from 6 to 12 years were observed interacting with their mothers in 15-min free-play and 15-min structured-task situations. Using a 15-sec interval coding procedure, 1 observer recorded the mother's response to specific antecedent behaviors of the child while a second observer recorded the child's response to specific behaviors of the mother. Hyperactive boys proved more active, less compliant, and less likely to remain on task than nonhyperactive peers. Mothers of hyperactive boys were less likely to respond positively to the child's social interactions, solitary play activities, or compliant on-task behavior. In addition, mothers of hyperactive boys imposed more structure and control on the child's play, social interactions, and task-oriented activities. It is suggested that the controlling intrusive style observed among the mothers of hyperactive boys, while initially a response to the child's overactive, impulsive, inattentive style, may further contribute to the child's behavioral difficulties.


Genetic aspects of verbal mediation in memory. When do children begin to store visually presented information using a speech code? Conrad has shown that at age 6, but not before, children have more difficulty in recalling items whose names rhyme than items whose names do not and concluded that at 6 years of age children begin to store information in memory using verbal labels. Experiment 1, using a technique similar to the one introduced by Conrad, showed that 4-year-old children memorized nonrhyming items better than rhyming ones. Experiment 2 used a different technique. Instead of comparing the performance obtained with 2 series of different items, one with rhyming and the other with nonrhyming names, we have, by using bilingual children, made comparisons within the same series of items. In one language the items had rhyming names and in the other, nonrhyming names. This technique controlled for the intrinsic difficulty of the items. The results of experiment 2 confirmed those obtained in experiment 1. Our conclusion is that 4-year-old children already use a speech code in order to store and organize information in memory.


The influence of verbal descriptions versus orientation codes on kindergartners' memory for the orientation of pictures. Kindergarten children who viewed a series of 10 line drawings of objects subsequently showed little ability to distinguish between these pictures and their left-right mirror images. However, the children's memory for orientation improved substantially when children were induced to (a) give detailed verbal descriptions of the pictures, or (b) specify a difference between characteristics on the child's side versus the experimenter's side of each picture, or (c) both. The 3 induced strategies were equally effective. On a posttest given approximately a week later, the children did not maintain use of any of these effective strategies.


Sentence comprehension in preschool children: testing an adaptive egocentrism hypothesis. A hypothesis proposing that preoperational egocentrism serves an adaptive function was used to predict the comprehension behavior of preschool children presented with sentences varying on a "personal" dimension. Personal sentences containing the subject's name were contrasted at 2 levels of syntactic complexity with impersonal sentences containing other familiar nouns. Significant effects were found for age, semantics, and syntax (all p's less than .001), with no sex effects or interactions. Personal sentences were better comprehended than impersonals at both levels of syntactic complexity. A second experiment was conducted to rule out "focusing of attention" as an alternative explanation. Variations in the likelihood of occurrence of the depicted event were added to the personal-impersonal contrast. High-probability personal sentences were significantly better understood than low-probability sentences, whether personal or impersonal (p less than .001). Results supported the adaptive egocentrism hypothesis in that sentence content describing the child and his personal experience facilitates the child's comprehension.


Problem-solving skills, locus of control, and the contraceptive effectiveness of young women. It was proposed that the lack of insight into the risk-taking behavior of many sexually active women who do not want to get pregnant may reflect the lack of an adequate framework from which to investigate the problem. The purpose of this study was to examine the relationships between contraceptive effectiveness and several cognitive factors. The sample consisted of 155 single women, 15.3-25.7 years of age, from a Planned Parenthood clinic and an abortion clinic. Contraceptive effectiveness, operationally defined as the number of unplanned pregnancies in a woman's history, was significantly and negatively related to means-ends problem-solving ability and a belief in internal control and significantly and positively related to a belief in chance control. It was suggested that these results support the utility of a cognitive, problem-solving approach to the study of contraceptive behavior.


Peripheral discrimination by three-month-old infants. 3-month-old infants made 2 types of discrimination with their peripheral vision. They discriminated between grossly different figures placed as far out as 30 degrees toward the periphery, and they discriminated between more subtly different figures, which differed only in the shape of their internal elements, out to 10 degrees. The results imply that infants can readily process stimuli with peripheral vision.


A comparison of fathers' and mothers' speech with their young chidren. The verbal interaction of 12 mothers and 12 fathers with their 19-month-old girls and boys in 2 situations was assessed. In 1 situation, all 3 family members were together, while in the other, each parent was alone with the child. Analyses indicated that when all 3 family members were together, fathers spoke less and took fewer conversational turns than mothers. Other than these significant differences, fathers' speech to their children was not different from mothers' speech on a range of quantitative and qualitative measures.


Maternal holding preferences: a consequence of newborn head-turning response. Salk observed that in an overwhelming majority of cases (80%) mothers prefer to hold their infants across the left shoulder. This preference occurs over a diversity of cultures and is not related to the hand preference of the mother. Salk suggested a fetal imprinting to the sound of the heartbeat as the mechanism responsible for this phenomenon. While such speculation is intriguing, it is not scientifically testable. 2 experiments were performed to examine a more testable hypothesis. Results of these studies suggest that the initial head-turning preference of an infant is related to the holding preference of its mother.


The origins of intentional vocalizations in prelinguistic infants. The development of the intention to communicate was examined by attempting to identify the point at which prelinguistic vocalizations are used by infants as a means of communication. This achievement was related to the infants' cognitive development. It was hypothesized that Piagetian stage 5 in the development of causality may be a prerequisite for the intentional use of vocalizations. 46 infants (X age = 10.7 months, range: 8 months--14.3 months) and their mothers were videotaped in a structured, naturalistic setting. 2 "frustration" episodes were devised to encourage communication, and the infants' vocalizations as well as other behaviors were coded by 2 observers. 2 Piagetian tasks were selected to assess the causal developmental level of the child. A significant relationship between causal developmental level and the occurrence of intentional vocalizations was found. The results support the hypothesis that stage 5 causal development may be a prerequisite to the use of intentional vocalizations.


Infant visual and vocal responses to television. To provide a first assessment of television influences on infants in the naturalistic setting of the home, visual and vocal behaviors of 72 infants 6 months of age were recorded during 4 days of exposure to various components of broadcast television programs: sound only, picture only, sound plus picture, or a control stimulus of unpatterned sound plus picture. Infants looked longer at the television set during the sound-plus-picture condition than during the picture-only condition, and they looked longer during both of these patterned picture conditions than during both of the other conditions that lacked a patterned picture. Also, infants vocalized more during the picture-only condition than during the sound-only condition. These findings demonstrate that infants attend to the naturalistic presentation of television stimulation and that they respond differentially to the visual and auditory components of television. The results are discussed in terms of the question of the long-term influence on infants' social responsiveness of substantial levels of exposure to the noncontingent, quasi-social stimulation provided by television.


Children's sensitivity to intraword redundancy in spoken words. Kindergarten, third-grade and fifth-grade children were tested on a same-different auditory discrimination task. Stimuli consisted of familiar and unfamiliar 3-letter words which were subdivided into high and low positional frequency word pairs. Analysis of correct same and different judgments supported the hypothesis that prereaders who have had normal language experiences develop sensitivities to intraword-redundancy relations. Children made significantly more correct same or different judgments when word pairs were high rather than low in summed positional frequency.


[Indication margins for pulmonary embolectomy]. Pulmonary embolectomy is the most effective form of treatment in acute, massive pulmonary embolism. Persistent cardio-respiratory failure, in spite of intensive medical therapy, presents a clear indication for embolectomy. A relative indication is given with the occlusion of more than 50% of the pulmonary arterial tree, especially in the case of beginning circulatory failure and contraindications to fibrinolytic therapy. Preoperative angiography is essential and should be performed whenever possible. A dramatic deterioration of the patient's condition may, however, require a prior reestablishment of sufficient circulation with relief of the right ventricle. According to the clarity of symptoms, either immediate thoracotomy or peripheral canulation and partial cardio-pulmonary bypass with subsequent angiography on the operating table should be preferred. Even a long resuscitation with persistently dilated, non-reactive pupils does not exclude operative success, and justifies neither the ommission nor the premature discontinuance of a resolute and consistent therapy.


[Percutaneous transluminal revascularization of lower-leg arteries]. In 19 of more than 130 patients treated with percutaneous transluminal angioplasty (PTA), obstructions of the distal popliteal artery and the lower leg arteries encouraged us to extend the treatment to this vascular region. Two weeks after PTA the arteries were patent in 16 of the 19 cases (84%). These results are comparable with those of vascular surgery, but are gained with less injury to the patient and a shorter hospitalization time.


[Peripheral arterial injuries due to fractures and dislocations]. Using 12 typical cases, which are tabulated, the diagnosis and therapy of combined bone and vascular injuries are demonstrated. Particular emphasis is put on a detailed presurgery diagnosis, if possible angiographic diagnosis. Early surgery, subject to a generous indication, with resection of the injured vascular segments and subsegment interposition of an autologous vein transplant is preferred. The correctness of this procedure is confirmed by the corresponding good postsurgery results.


[Crohn's proctocolitis with involvement of the esophagus and mouth. Case report]. A case of esophageal Crohn's disease occurring in a 40-year-old woman with proctocolitis and oral manifestation is reported. A possible connection between Crohn's disease and Behçet's syndrome is discussed. A survey of the literature indicates that comparable lesions occur very rarely.


[Must cold nodules continue to remain absolute indications for surgery?]. The vast increase in thyroid operations in recent years, resulting partly from the continued development of nuclear diagnostic techniques, has led to the acquisition of new knowledge. Retrospective research on 6252 thyroid operations performed during the last 15 years shows an increase in the number of scintigraphically cold thyroid nodes, both absolutely and in relation to the total number of thyroid operations. With increased use of surgery, the malignancy rate in cases with cold thyroid nodes has fallen to 3.2%; the malignancy rate in cases where scintigraphy gave other results is 1.2%. Favorable developments have occurred in the earlier detection of cancer and in histologic diagnosis. In the 1960s, one-half of malignant goiter cases were first detected in stages III and IV of the TNM scala and could therefore be given only a palliative operation. Today, 80% of cases are detected and treated curatively in stage I. Whereas from 1964 to 1969 almost 50% of malignant goiters were histologically undifferentiated, today 90% are well-differentiated carcinomas. In view of these statistics, use of the scintigraphic diagnosis of cold thyroid nodes as an invariable indication for surgery should be reconsidered.


[Active search for Meckel's diverticulum]. Examination for Meckel's diverticulum is generally performed in each case of laparotomy where the incision allows observation of the small bowel without danger of spreading the infection. In 65 cases, pathologic alterations were found in 14 (= 21,5%). Postoperative bowel obstruction due to resection of Meckel's diverticulum has been found twice (3%), one patient died. It is suggested that Meckel's diverticulum be removed whenever possible.


[Does a one-time colonic or rectal resection without protective colostomy increase the rate of postoperative complications?]. The rate of postoperative complications is the decisive criterion in evaluating the preoperative preparation of the large intestine, the operative methods, and the technique of anastomosis. Preparations for colorectal surgery include administration of antibiotics and the use of a three-row suture method of anastomosis without the protection of an intestinal fistula. The results of 1054 colorectal resections are promising: The rate of anastomotic insufficiency was 3.9% after resection of tumors and 4.9% after resection of inflamed diverticula. Lethality from local causes was 1.2% and 1.9%, respectively. Disturbance of wound healing occurred in 10.7% of the cases.


[Expanded PTFE (polytetrafluoroethylene) vascular prostheses--a new path of arterial and venous replacement]. Based on existing experimental and clinical observations the expanded PTFE graft shows convincing advantages in some indication fields (e.g., vascular access for hemodialysis, venous reconstruction) compared with conventional porous prostheses and biografts. On the other hand, we have to realize that expanded PTFE is not yet qualified to be the optimal substitute for small arteries. In spite of encouraging preliminary results, the use of this new type of vascular prosthesis still requires critical evaluation to avoid unpredictable failure due to uncritical surgical optimism (caution: Sparks disaster!). Further improvements may be expected from a better anchorage in the surrounding tissue (e.g., external velour), and from an increase of antithrombogenity of the inner surface.


[Possibilities of using ultrasonic tools in changing endoprostheses]. In joint replacement surgery an exchange of endoprostheses is technically most difficult, time consuming, and extremely unpleasant for the patient. Removal of the implant without damaging the bone entails many problems. Experience has shown that, in addition to the normal operative technique, the ultrasonic method may be very helpful. Ultrasonic implements that melt thermoplastic implants facilitate the removal of those implants (e.g., polymethylmethacrylate, polyethylene), protect the tissue, and save time. This method is not an alternative to the normal operative technique, but an additional help.


A quantitative electron microscopic analysis of transcription in sea urchin embryos. In an effort to define stage-specific embryonic patterns of sea urchin transcription, we have examined by electron microscopy the distribution of nascent RNP fibrils in dispersed chromatin from nuclei of Strongylocentrotus purpuratus gastrulae. Detailed analysis of individual embryonic nuclei has revealed several new features of nuclear RNA production. Most (82%) of the active chromatin regions observed were represented by only a single fibril. 11% of the active regions contained multiple RNP fibril arrays with an average RNA polymerase density of 1.7 +/- 1.0 polymerases/micron of chromatin and an average contour length of 4.7 +/- 2.8 microns chromatin. An analysis of the lengths of RNP fibrils in single vs. multiple fibril arrays indicates that the differential distribution of RNA polymerases is due to different rates of initiation rather than to different lengths of transcription units (assuming the rate of RNA chain elongation to be constant). We discuss these data in relation to various transcriptional parameters measured by other workers and to EM analyses of other embryonic nuclei. Elucidation of transcriptional patterns in gastrula embryos can provide the basis for further comparative studies of transcription at other stages of sea urchin development in which rates of total genomic transcription vary but the rate at individual loci is as yet unknown.


Effect of temperature on morphology and DNA-content of polytene chromosomes in Drosophila. Feulgen-DNA contents and chromosome lengths and projected areas were measured in salivary gland nuclei from Drosophila prepupae which had developed at 25 degrees or 15 degrees C. Nuclei from a given prepupa fell into 3 to 5 DNA classes corresponding to different levels of polyteny. The 15 degree nuclei tended to fall into higher classes than those from 25 degree-reared animals, and their chromosomes were, on average, about 50% wider. Chromosomes within a given DNA class did not differ significantly in mean area, length or width between the temperature groups, and slight apparent differences in mean DNA content were attributable to systematic microdensitometric errors associated with differences in the spreading behaviour of the nuclei. On cytological examination, chromosomes from the two temperature groups differed mainly in width and stain intensity, but some other differences in appearance could not be accounted for by levels of polyteny. The mean length of the chromosome complement was about 400 microns. From one polytenic level to the next the chromosomes increased by about 10% in length, 40% in width and 17% in mean absorbance. The DNA content approximately doubled; small apparent deviations from the 1:2 ratio could have been due to microdensitometric error or to underreplication of heterochromatin.


Adenomatous and carcinomatous changes within hyperplastic colonic epithelium. Hyperplastic colonic polyps are benign, nonneoplastic proliferations; unlike tubular and villous adenomas, they do not predispose the patient to colonic cancer. Theoretically, these hyperplastic polyps, like normal colonic epithelium, should be able to undergo adenomatous transformation and possibly develop into cancer. In this report, we discuss an unusual case of a patient with numerous hyperplastic polyps, in which adenomatous changes occurred and cancer developed. We also discuss the significance of these changes as they relate to the polyp-cancer sequence.


Colonic adrenocarcinomas in patients with ureterosigmoidostomies. Two additional cases of adenocarcinoma of the sigmoid colon occurring at the site of ureterosigmoidostomy are reported. The high risk of this complication occurring in patients who have undergone ureterosigmoidostomy is described. The possible shortness of the interval from diversion to development of an adenocarcinoma, especially in those cases involving carcinoma of the bladder, is emphasized. It is strongly recommended that careful follow up of such patients should begin within several years of establishment of the ureterosigmoidostomy.


Urgent hemorrhoidectomy for hemorrhoidal thrombosis. Sixty-five patients underwent hemorrhoidectomies for acute thrombosis. All biopsy specimens contained intravascular thrombi. Early postoperative complications included urinary difficulties and bleeding. Late postoperative complications included anal stenosis.


Sigmoidoscopic examinations with rigid and flexible fiberoptic sigmoidoscopes in the surgeon's office: a comparative prospective study of effectiveness in 1,012 cases. The results obtained from 1,012 examinations in an on-going, cooperative study indicate that the overall yield provided by use of the flexible fiberoptic sigmoidoscope is 3.2 times greater than that of examinations with the rigid sigmoidoscope. More than twice (2.4 times) the number of polyps and more than three times the number of cancers were detected with the flexible fiberoptic sigmoidoscope. Experienced endoscopists can perform an examination with the flexible fiberoptic sigmoidoscope expeditiously in the office with minimal patient preparation, a high level of patient and physician acceptance, and relative safety when the usual mandatory colonoscopic precautions and guidelines are obeyed. The extraordinary advantages demonstrated by this study warrant wide clinical application of the flexible fiberoptic sigmoidoscope. We strongly recommend provision be made for appropriate training of physicians in the use of the instrument.


Biofeedback in the management of partial anal incontinence: a preliminary report. This method of improving anal continence is recommended for patients with partial anal incontinence, in whom some functioning anal sphincter remains. It is particularly applicable for treating those patients who have sustained operative trauma, but is less helpful for those who have generalized sphincter weakness; however, any patient with some sphincter function may benefit. Emotionally unstable patients are less likely to benefit. Although the series was small, the results were considered sufficiently gratifying to justify a preliminary report.


Spontaneous disruption of the colon associated with pyonephrosis: report of a case. We report a case of reno-colic fistula with abscess formation, which was treated by staged surgical procedures. One must be wary of automatically implicating the colon as the primary source of the problem when the colon and adjacent organs are involved in an inflammatory process. In cases involving the superior segments of the colon, the kidney or pancreas may be the source of the fistula.


Leiomyosarcoma of the appendix: report of two cases. Two cases of leiomyosarcoma of the appendix are reported. Leiomyosarcoma of the large intestine is rare, and leiomyosarcoma of the appendix has not been previously reported.


Peritoneal nocardiosis: report of a case. A case of primary peritoneal nocardiosis is presented. The patient died, despite prompt, aggressive and appropriate antibiotic therapy. Decreased patient resistance is suggested as the cause of the overwhelming nature of the infection in this case. The importance of administering prophylactic antibiotics on a long-term basis to prevent recurrence after successful treatment is stressed. Although nocardial infections are rare, they may become more common because of the current widespread use of immunosuppressive therapy.


Arterio-enteric fistulas.

Arterio-enteric fistulas. The colorectal surgeon may well see arterioenteric fistulas in patients who have rectal bleeding. The initial bleeding usually stops, allowing time for evaluation, which should be done promptly because subsequent bleeding may be fatal. Exploratory laparotomy is frequently necessary to arrive at the correct diagnosis. Surgical management necessitates individual assessment of each case, but best results seem to be obtained when the infected graft is completely removed.


Arteriovenous malformation of the upper rectum in an unusual site: report of a case and review of the literature. A single case of vascular ecstasia involving the upper rectum and manifesting as an ulcerative lesion is reported. This is the first report of such a case. The authors emphasize the importance of exploratory laparotomy and careful histologic studies in diagnosting such cases.


[Primary hyperparathyroidism (author's transl)]. Experience gained from 100 patients with surgically and histologically proven primary hyperparathyroidism over a period of 14 years led to simplification of diagnostic procedures and development of a surgical scheme. Over the years patients with discrete disease symptoms or with asymptomatic disease were observed more frequently. This can be seen as the result of earlier diagnosis due to increasing spread of laboratory autoanalysers and the resulting routine calcium determination. Development of surgical intervention is characterised by omitting preoperative diagnostic procedures to determine localisation, a schematised operation, and more reliance on macroscopic criteria rather than on quick sections during surgery.


[Prognostic aspects of early gastric carcinoma (author's transl)]. The results of treatment of early gastric carcinoma were analysed in 65 patients. In 33 patients the operation was performed 5 years ago. The 5-year-survival rate was 70%. Prognosis was predominantly influenced by the histology of the tumour. Signet ring cell and anaplastic early carcinomas (diffuse type) had a worse prognosis than intestinal (differentiated) forms. Carcinomas localised wholly in the mucosa had no better prognosis than those penetrating into the submucosa. There is no choice of surgical method according to prognostic criteria as the diagnosis "early gastric carcinoma" can be made only postoperatively from the resection material. Bioptic proof of carcinomatous gastric mucosal changes requires full observation of the rules of cancer surgery.


[Surgical treatment of left ventricular aneurysm (author's transl)]. 174 cardiac aneurysms were resected between 1970 and 1977. In 49 patients the remaining contractile segment was revascularised at the same time. The hospital mortality was 10.3%, the late mortality was 14%. The uncorrected cumulative survival rate calculated by the acturial method was 90% at 3 years (84--96), and 80% at 5 years (74--85). Results were excellent or good in two thirds of the survivors; 44% were free of angina pectoris, 40% were improved, 73% had no disturbances of cardiac rhythm, and in 15% they were improved. Comparison of the pre- and postoperative ejection fraction showed that the indication for surgery of a cardiac aneurysm exists when more than 20% of the musculature of the left ventricle is affected, when the total ejection fraction is larger than 10% when one vessel is affected, and more than 30% when more than one vessel is affected. Contraindications are diffuse coronary heart disease, when ejection fraction of the contractile segment is less than 30% reduction in contractility of the ventricular septum, and the generally applicable surgical contraindications.


[Prevention of duodenal ulcer recurrence with cimetidine (author's transl)]. The effect of long-term prophylaxis of duodenal ulceration with cimetidine was tested in a double blind trial. In 20 patients treated with cimetidine there was a four-fold reduction in the relapse rate when compared with 18 placebo-treated patients. However, treatment of the acute phase of ulceration with cimetidine increased the recurrence rate more than five-fold when compared with placebo treatment. Slow healing of ulceration was followed by a two-fold incidence of recurrence when compared with rapid healing. From the results it is concluded that recurrence occurs in patients after slow healing and (or) previous cimetidine treatment if long-term prophylaxis with cimetidine is not carried out.


[Acute renal failure in alcoholic myopathy (author's transl)]. Two chronic alcoholics developed acute renal failure from alcoholic myopathy (acute alcohol-induced rhabdomyolysis). Severe muscle pain developed and was associated with transitory oligo-anuric renal failure, requiring dialysis in one patient. In addition to the typical history and clinical symptoms, excessive elevation of muscle enzymes, especially creatine-kinase, and the appearance of myoglobin in serum are characteristic. Brown discoloration of the urine and a falsely positive test for "blood" due to the presence of myoglobin in urine in the absence of red blood cells are also typical. Definite changes can be demonstrated histologically and electromyographically during the acute stage. It is likely that this condition is more frequent than the sparsity of published reports indicates.


[The place of autotransfusion with normovolaemic haemodilution in vascular surgery (author's transl)]. The ever-increasing demand for donor blood, the risks of donor-blood transfusions and economic considerations have made the use of autotransfusion desirable. Among methods for producing autologous blood stores that of obtaining autologous blood with simultaneous normovolaemic haemodilution (using dextran 60; Macrodex 6%) 2--4 days before operation is especially practicable for elective reconstructive vascular surgery. But the same method can also be used in general surgery. Personal experience in operations on 120 patients has shown that the need for donor blood was reduced to 20% of all transfused blood. Improved flow properties of the blood by decreasing viscocity after normovolaemic haemodilution is of particular value in stages III and IV of chronic arterial occlusive disease.


[Diagnosis of peripheral arterial occlusive disease: clinical, haemodynamic and metabolic investigation (author's transl)]. The value of quantitative (venous-occlusion plethysmography), semiquantitative (ultrasound-Doppler method; walking distance; duration of bicycle ergometry) and metabolic (lactate, pyruvate) tests was assessed in 41 patients with arterial occlusive disease of the upper leg type. It was demonstrated that blood pressure measurement using the Doppler method is of great importance. Significant differentiation between normal and impaired blood flow was obtained with venous-occulsion plethysmography for both "first flow" and "peak flow". The diagnostic value as to the degree of peripheral arterial disease was similar for plethysmography and Doppler methods. Duration of bicycle ergometry provided an important pointer to the degree of functional impairment of the affected extremity. The level of lactate and pyruvate in femoral venous blood is suitable more for serial controls and assessment of treatment in patients in whom haemodynamic studies have already clarified the diagnosis of impaired blood flow.


[Diabetic neuropathic cachexia (author's transl)]. Marked weight loss with cachexia together with severe depression and pain from symmetrical peripheral neuropathy were noted in a 66-year-old man, known to have had diabetes for six years, which required insulin on admission to hospital. The patient died of bronchopneumonia after one year. The severe neuropathy was proven both neurophysiologically and at necropsy. There was no diabetic retinopathy and no histological evidence of renal glomerulosclerosis. There was no evidence of a malignant tumour either clinically or at necropsy.


[Surgical treatment of pulmonary metastases (author's transl)]. 120 pulmonary metastases were resected in 67 patients. The five year survival rate is 42.3% after surgical removal and only 2.6% without surgery. Up to 4 resected pulmonary metastases have no influence on the prognosis. In cases with several metastases resection should be strictly limited. Lobectomy had the best five year survival rate (58%); wedge excision and pneumonectomy fared clearly worse (25% each). When the lung is the first filtre of haematogenous metastases the five year survival rate is better (48%) than when the liver filters first (18.5%). A prolonged interval before recurrence improves prognosis. Intervals of less than a year lead to survival after 4 years in only 14.5%, intervals of more than two years are accompanied by survival of 65%.


[Routine diagnosis of bacteriuria: estimation of urinary sediment or counting blood cells? (author's transl)]. Testing of a method of bacteriuria diagnosis which would be feasible for outpatient routine work and highly reliable while requiring little cost and effort, revealed the clear superiority of examining the uncentrifuged urine in the counting chamber over the sedimentation method. Whereas the accuracy of the sedimentation method in bacteriuria diagnosis is about 50%, the counting chamber method gave correct results in more than 90% of the cases. This entails saving in terms of manhours. The only drawback of the counting chamber method is its higher rate of false-positive findings caused by the fact that the microscopic identification of bacteria enters into the final count. This drawback, however, is more than made up by the reduced amount of material and time involved in this procedure.


[Combined chemotherapy of metastasing melanoblastoma using ifosfamide and cis-platinum (II)-diamminodichloride (author's transl)]. 15 patients with metastasing melanoblastoma of stage III and IV were treated with a combination of cis-platinum (II)-diamminodichloride and ifosfamide. In 3 cases complete remission occurred, in 5 partial remission with tumour regression of more than 50%. The response rate is around 50% at present. Two cases showed no change after 6 months of chemotherapy.


[Cytological diagnosis of thyroiditis (author's transl)]. In 2347 patients fine needle aspiration of the thyroid gland was performed. In 49 cases (2.1%), a final diagnosis of thyroiditis was established. Non-specific granulomatous thyroiditis occurred most frequently (n = 24), followed by lymphocytic hypertrophic thyroiditis Hashimoto (n = 18), focal lymphocytic (n = 5), atrophic lymphocytic (n = 1) and chronic fibrosing thyroiditis (n = 1). Fine needle aspiration biopsy is most suited to diagnose granulomatous thyroiditis. In Hashimoto's thyroiditis cytological investigations are superior to estimation of thyroglobulin antibodies. The cytological method is of little value for the diagnosis of atrophic lymphocytic and chronic fibrosing thyroiditis.


[Biological availability of spironolactone in two different galenic forms (author's transl)]. The biological availability of spironolactone in two different galenic preparations (Spiro-Tablinen and Aldactone-100 Caps) was investigated in a single-blind, randomised, cross-over study in six healthy probands. The serum concentration of canrenone after oral intake of spironolactone (100 mg) was investigated in the steady state as well as the renal excretion of canrenone. There were no statistically significant differences between the two preparations either in the course of the serum concentration of canrenone or in the cumulative renal excretion.


[Treatment of reflux oesophagitis with cimetidine (author's transl)]. The effect of cimetidine on reflux oesophagitis was studied in a double-blind trial. Sixteen patients were given cimetidine 1.6 g/d, 20 patients received a placebo. Within the first six weeks the oesophagitis improved both on cimetidine and the placebo, but the patients taking the former had fewer complaints during the day than those on a placebo. Continuing the regimen for another six weeks further improved the endoscopic findings in patients with cimetidine but not in those on placebos. Complaints lessened during the sixth to twelfth week during cimetidine treatment, but remained unchanged under placebo administration. Complete healing of the oesophagitis was achieved in only 33% of patients with uncomplicated oesophagitis (grade I-III) and in 6% of those with severe complicated oesophagitis (grade IV). If non-surgical treatment is indicated, it must be continued through at least 6-12 weeks.


[Demineralisation of bone in chronic arterial insufficiency (author's transl)]. 125I-nuclide-absorption measurement demonstrated a statistically significant decrease in mineral content of the calcaneus in 44 patients with arteriographically proven arterial occlusive disease of the lower limbs. The loss of mineral content was dependent on the clinical degree of the vascular disorder (stages according to Fontaine's classification) and the site of the arterial occlusion. There was no demonstrable relationship between the degree of demineralisation and the duration of the vascular disorder. If treatment proved successful there was a significant rise in the mineral content of the calcaneus.


[Course of alcoholic predelirium during treatment with piracetam: results of serial psychometric tests (author's transl)]. Thirty-six male alcoholics in a mild predelirial state were studied with a series of psychometric tests (reaction time to light and sound, reaction to multiple sequential stimuli, apprehension and tachistoscopic appreciation test, achievement and concentration test analogous to the Pauli test). The degree of psychometrically determined abnormalities pointed to serious cerebral lesions even in the mild predelirial stage and exceeded the expectations gained from clinical impression. The disorders decreased in the course of treatment but were present for at least another three days. Additional treatment with piracetam (Normabrain, Nootrop, 9 g/d intravenously) in eighteen patients significantly improved the results of the achievement and concentration tests, while there was no or only slight improvement in the other  tests.


[The influence of primidone on thyroid function (author's transl)]. The influence of primidone on thyroxine level, T3 index, FT4 index, triiodothyronine level, T3 (RIA)/T4 (RIA) quotient as well as on the TSH basal and stimulated values was investigated in 30 children on long-term treatment. The values obtained were compared statistically with those of a normal group. During primidone treatment a drop in T4 level and in FT4 index as well as an increase in T3 (RIA)/T4 (RIA) quotient was observed. On the other hand the triiodothyronine level and the T3 index were not influenced. The TSH basal and stimulated values were not statistically different from the control group. Thus the primidone-treated children are euthyroid according to the TRH test. Primidone probably stimulates hepatocellular thyroxine breakdown.


Half-life of somatostatin-like immunoreactivity in canine plasma. Previous estimates of the half-life of synthetic somatostatin have been based upon the disappearance rate of 125I-labeled Tyr1-somatostatin. In the present study, the half-life of infused synthetic somatostatin was determined by RIA and compared with the duration of its suppressive action upon plasma insulin and glucagon. After the end of a 2-h infusion of somatostatin (500 ng/min), the radioimmunologically measured half-life was 1.82 min. The reappearance half-times for insulin and glucagon were 1.4 and 6.7 min, respectively. These data show that calculations of the half-life of somatostatin-like immunoreactivity in plasma may differ from estimates based on the duration of its biological activities, which may differ from one another.


Antifertility effects of an aromatase inhibitor, 1,4,6-androstatriene-3, 17-dione. 1,4,6-Androstatriene-3,17-dione (ATD), previously reported by us to be an aromatase (estrogen synthetase) inhibitor, was found effective in inhibiting mating and ovulation in the rat. Mating did not occur for as long as treatment was continued (up to 13 days) in 68% of the rats. In the remainder, mating and ovulation were delayed for at least 4 days past the expected day of proestrus and for an average of 5.8 days. Five animals which had been treated for 6 days mated 2 days after treatment was discontinued and all were pregnant at autopsy on day 8 of pregnancy. In contrast, when treatment was continued after mating, implantation sites were absent when the animals were examined on day 8 of pregnancy, indicating ATD may also be effective postcoitally. ATD had no significant hormonal activity in bioassay but prevented the rise in ovarian estradiol secretion on the afternoon of proestrus. Estradiol benzoate counteracted the effect of ATD when administered concomitantly, so that mating occurred at the normal time in all eight rats and ovulation occurred in six of the eight rats. The above results suggest that the aromatase inhibitor, ATD, may act in vivo to inhibit fertility by inhibition of estrogen biosynthesis.


Angiotensin stimulation of vasopressin release from the rat hypothalamo-neurohypophyseal system in organ culture. Angiotensin II (AII) stimulated vasopressin (VP) release from the rat hypothalamo-neurohypophyseal system (HNS) in organ culture in a concentration-dependent manner. Exposure to AII at 10(-8) M for 1 hr yielded a 1.8-fold increase in VP release over control release (P less than 0.01), while a 1-h exposure to 10(-5) M AII resulted in a 4-fold increment over control VP release by HNS explants maintained in organ culture for 3 days (P less than 0.01). Saralasin, an AII antagonist, blocked AII stimulation of VP release without significantly altering basal VP release by the HNS explants. Saralasin did not interfere with stimulation of VP release by acetylcholine or nicotine. Tetrodotoxin (10(-7) g/ml) also blocked AII stimulation of VP release. These findings suggest that action potentials are generated in response to AII stimulation of specific receptors in the HNS and are requisite for VP release in response to this stimulus.


Corticosterone levels during midgestation in the maternal plasma and fetus of cleft palate-sensitive and -resistant mice. Corticosterone levels in the maternal plasma and fetal extracts during days 11--15 of gestation were measured by RIA in cleft palate-sensitive A/J and -resistant C57BL/6J mice. In both strains, the maternal plasma corticosterone increased from 10 micrograms/100 ml in nonpregnant animals to 100 microgram/100 ml between days 12--13. In A/J mice, the corticosterone level declined to 60 micrograms/100 ml by day 15, whereas in C57BL/6J mice, the corticosterone concentration remained elevated during this period. In contrast, fetal corticosterone levels in both strains remained unchanged between days 11-13 (0.5--1.0 ng/embryo) and increased on days 14 and 15 to 4--7 ng/embryo. The absence of significant differences in the concentration of maternal or fetal corticosterone between A/J and C57BL/6J mice suggests that the in vivo strain differences in the glucocorticoid susceptibility to cleft palate production are not related to any intrinsic differences in the endogenous levels of corticosterone between these two strains during midgestation.


Stimulation of thyroglobulin synthesis in thyroid polysomes by soluble factors from reticulocyte lysate. The addition of rabbit reticulocyte lysate supernate to membrane-bound calf thyroid polysomes resulted in stimulation of [3H]leucine incorporation into acid-precipitable material; 91% of these total radioactive peptides was precipitated by thyroglobulin antibodies. The ability of reticulocyte lysate supernate to stimulate thyroglobulin syntheis was pH and temperature sensitive. The addition of 25 microM aurintricarboxylic acid resulted in an 85% inhibition of [3H]leucine incorporation.


In vivo patterns of circulating steroids in adult male rats. I. Variations in testosterone during 24- and 48-hour standard and reverse light/dark cycles. The in vivo pattern of circulating testosterone (T) was investigated in unrestrained, conscious, individual male rats during 24 and 48 h. Each rat exhibited its own characteristic in vivo diurnal rhythm. When these individual patterns of T were grouped, the mean values also showed a diurnal rhythm. Although T concentrations peaked during the dark and light periods, the most pronounced elevations were observed during the dark periods (2200--2330 h). Lowest T concentrations were noted during the late dark and early light hours (0400--0700 h). The pattern of T was further investigated by extending the experimental period to 48 h. The pattern of T observed during the first 24 h repeated itself on the second day, thus demonstrating the authenticity of this diurnal rhythm. Rats were exposed to a reversed light/dark regimen which resulted in an inversion of the rhythm or circulating T. These data indicate that the pattern of circulating T is not intrinsically regulated.


Modulation of follicle-stimulating hormone-sensitive rat testicular adenylate cyclase activity by guanyl nucleotides. We have studied modulation of FSH-sensitive adenylate cyclase activity in testes of immature rats by guanyl nucleotides. Highly purified hFSH alone stimulated adenylate cyclase activity 2.2-fold over basal levels. Addition of the GTP analog, 5'-guanylyl imidodiphosphate [Gpp(NH)p], caused an additional 2.8-fold augmentation of adenylate cyclase activity to 6 times over basal levels and 3.7 times greater than that seen in the presence of Gpp(NH)p alone. GTP did not significantly stimulate basal levels of adenylate cyclase and augmented FSH stimulated activity by 1.4-fold; other nucleotides were without effect. Half-maximum activation of adenylate cyclase in each instance was produced by approximately similar concentrations of either guanyl nucleotide (about 10 microM). The Km for hormone activation of adenylate cyclase was nearly the same in the presence and absence of Gpp(NH)p. Maximum adenylate cyclase stimulation in the presence of nucleotide and/or hRSH was always less than obtained by fluoride alone. Of all nucleotides tested, only GTP and its analog, Gpp(NH)p, significantly augmented FSH stimulation of testicular adenylate cyclase activity. Gpp(NH)p also markedly inhibited binding of radiolabeled hFSH to testicular receptor, but at a concentration 15-fold greater than that required for significant stimulation of testicular adenylate cyclase activity. The results suggest a specific role for guanyl nucleoside triphosphate in regulation of FSH effects on testicular adenylate cyclase activity.


Autonomous secretion of follicle-stimulating hormone by long term organ cultures of rat pituitaries. Pituitaries removed from ovariectomized adult rats were maintained for 18 weeks in organ culture using three different culture media. Gonadotropin secretion was assessed by RIA and was correlated with the histological features of the cultures. In medium favoring prolonged survival of the cultures, LH content of the medium fell to a low level within a few days. In the same cultures, FSH production initially decreased before increasing and leveling at a plateau which persisted until the end of the culture period. Cultures in medium unsuitable for long term survival of pituitary tissue displayed a similar decrease in LH production along with a gradual fall of FSH. It was concluded that contrary to LH, FSH may be secreted autonomously by pituitaries removed from hypothalamic control, provided that culture conditions are adequate for survival of gonadotropes.


Effect of fasting on insulin binding to hepatocytes and liver plasma membranes from rats. Binding of [125I]iodoinsulin to isolated hepatocytes from fed and fasted rats was measured. Hepatocytes from fed rats bound significanlty more [125I]iodoinsulin at insulin concentrations ranging from 0.15--100 nM. Scatchard and average affinity profile data analyses showed no significant difference in the affinities of the binding sites but indicated a decrease in the receptor concentration of the hepatocytes from fasted rats. In contrast to hepatocytes, liver plasma membranes of fasted rats showed increased insulin binding at all insulin concentrations, except the highest level of 100 nM. Analysis of the data indicated a significant increase in the affinity of the receptors but no change in the receptor concentration. Evidence is presented that the differences in the results obtained with hepatocytes and membranes were not due to the differences in the recovery of the plasma membranes. The results suggest that insulin binding by intact hepatocytes does not necessarily reflect the receptor protein content of the cell membrane and that the liver cell modulates its response to insulin by changes in the architecture of the plasma membrane.


The effect of subcutaneous injections of melatonin, arginine vasotocin, and related peptides on pituitary and plasma levels of luteinizing hormone, follicle-stimulating hormone, and prolactin in castrated adult male rats. A sc injection of 2 micrograms arginine vasotocin (AVT) administered every 2 h for a 25-h period starting 1 h after castration of adult male rats caused a 43% reduction (P less than 0.05) in plasma levels of LH compared to diluent-treated castrated controls. In Exp 2, a sc injection of 5 micrograms AVT or diluent was administered to intact or acutely castrated male rats every 3 h for 48 h. After AVT administration, both plasma LH (P less than 0.001) and FSH (P less than 0.05) were significantly reduced, with a concomitant increase in pituitary levels of these gonadotropins. Using the same injection regimen in Exp 3, 250 micrograms melatonin had no effect on plasma or pituitary levels of LH in castrated male rats. In the fourth experiment, neither 1 IU arginine vasopressin nor 1 IU oxytocin had an effect on plasma or pituitary levels of LH, whereas 1 IU of AVT significantly lowered plasma levels of LH (P less than 0.05) and prevented the fall in the pituitary level of this gonadotropin (P less than 0.01) when compared to diluent-treated castrated control rats. Oxytocin (1 IU) significantly inhibited (P less than 0.01) plasma levels of FSH and raised plasma levels of PRL (P less than 0.01) in castrated male rats. No effect on plasma titers of PRL were observed after treatment of castrated rats with AVT in Exp 2 or 4. It is concluded that in acutely castrated male rats, AVT could possibly act either on the hypothalamus and/or the pituitary to affect pituitary and plasma levels of gonadotropins.


Studies on rat pituitary homografts. I. In vitro biosynthesis and release of growth hormone and prolactin. Homologous anterior pituitaries grafted under the kidney capsule in hypophysectomized rats were studied 30 days after transplantation. Some cells maintained the ultrastructural features peculiar to the various cell types of normotopic glands, while the others were characterized by few, small, dense granules, spherical or polymorphic, located peripherally in the cytoplasm. This picture might be due to a functional adaptation which occurs in pituitary cells still producing different hormones, once removed from central nervous system control. The major change in polypeptide hormone composition of graft homogenates relative to normotopic pituitaries is the fall in GH and PRL concentration. The in vitro incorporation of L-[3H]leucine into the two hormones and the release of radioactive GH and PRL from L-[3H]leucine-prelabeled tissue fragments are also greatly decreased. The decrease in concentration, in vitro biosynthesis, and release of GH per mg tissue protein are approximately 87, 91, and 93%, respectively. These results might be due primarily to a decrease in the number of somatotrophs and/or in their secretory activity, with relatively minor changes in GH intracellular transport and turnover. In contrast, a clear-cut fall in in vitro turnover was detected for PRL, as shown by the fact that decreases in biosynthesis and release per mg tissue protein of this hormone (approximately -95% and -99%, respectively) by far exceed the decrease in the tissue concentration (-74%). These data indicate that in in vitro secretory activity of mammotrophs is greatly reduced in the grafts with respect to the normotopic glands. Thus, the high secretory activity previously reported in hypophysectomized rats bearing pituitary grafts should be attributed to the lack of the inhibitory control of the central nervous system rather than to an increase in secretory capacity under nonrestrained conditions.


Subcellular distributions of parathyroid hormone, hormonal precursors, and parathyroid secretory protein. Distributions of parathyroid hormone (PTH), proparathyroid hormone (ProPTH), preproparathyroid hormone (PreProPTH), and parathyroid secretory protein (PSP) were analyzed in subcellular fractions prepared from homogenates of bovine parathyroid glands. Slices of bovine parathyroid glands were incubated with radiolabeled amino acids for 3--30 min to selectively label newly synthesized proteins. Subcellular fractions were prepared from homogenates of the gland slices by differential centrifugation. Newly synthesized labeled hormonal polypeptides in the fractions were analyzed by electrophoresis on polyacrylamide gels, and total amounts of PTH and ProPTH (previously formed and newly synthesized) were determined by immunoassay. Ninety percent of total immunoreactive, 70--80% of newly synthesized PTH, ProPTH, and PreProPTH, and 50% of PSP were found in sedimentable particulate fractions. The low speed (800 X g) pellet, which consisted predominantly of cell debris and nuclei with adherent remnants of cytoplasm, contained 30--50% of the ProPTH and PTH. The intermediate speed (10,000 X g) pellet, which contained granules, was relatively enriched in PTH. Most particulate-associated hormone could be solubilized by treatment with deoxycholate (DOC) 98% and 97% of radiolabeled and 93% and 83% of immunoreactive ProPTH and PTH, respectively, in particulates sedimenting at 10,000 and 105,000 X g were rendered DOC-soluble. Approximately 50% of the PTH and ProPTH in the particulates resisted digestion by combined trypsin and chymotrypsin, whereas PreProPTH was completely susceptible to proteolysis. Up to 50% of the radiolabeled PTH and ProPTH added exogenously to parathyroid gland slices before homogenization became associated with the particulate fractions, and 70--80% or radiolabeled PreProPTH added to the subcellular fractions readily associated with the sedimentable material. The results indicate that in homogenates of parathyroid glands, PTH, ProPTH, PreProPTH, and PSP are associated with particulate structures. Furthermore, up to 50% of the association of ProPTH, PTH, and PSP with particulate fractions seems to be nonsepcific and occurs during the disruption of the tissues. The remaining 50% or more of hormonal protein is presumably sequestered within membrane-limited structures, such as microsomal vesicles. The complete susceptibility in particulate fractions of newly synthesized PreProPTH, but not of ProPTH, to limited proteolysis indicates that the two precursors are located in different subcellular compartments and suggests that PreProPTH is converted to ProPTH before its entry into the intracisternal space of the endoplasmic reticulum. Alternatively, the PreProPTH identified in parathyroid gland slices may represent polypeptide chains synthesized in the cell sol on polyribosomes that are not attached to endoplasmic reticulum but are adsorbed nonspecifically to the particulate fraction of the cell during the process of tissue homogenization.


Comparative studies of receptor binding and steroidogenic properties of angiotensins in the rat adrenal glomerulosa. Angiotensin and analogs were tested in isolated rat adrenal zona glomerulosa cells to find if there was a correlation between receptor affinity and steroidogenic potency. Comparative receptor-binding affinities and corresponding aldosterone-releasing effects obtained for each analog were: [Asp1, Ile5]angiotensin II, 1.0 and 1.0: [Asp1, Val5]angiotensin II, 0.69 and 1.65; [Asn1, Val5]angiotensin II, 1.18 and 0.68; [Sar1]angiotensin II, 2.07 and 1.7; [Me2Gly1]angiotensin II, 0.63 and 0.72; [Ile5]angiotensin III, 0.72 and 0.59; [Val5]angiotensin III, 0.92 and 0.34; [Ile5]angiotensin I, 0.007 and 0.051; des-Asp1-[Ile5]-angiotensin I, 0.004 and 0.03; and [Val5, Ser9]angiotensin I, 0.03 and 0.098. Taken as a group, these agonist analogs demonstrated good correlations between these two variables (r = 0.76; P less than 0.001). There was parallelism between binding inhibition and aldosterone-releasing effect when position 5 was substituted with isoleucine, regardless of the substituent in position 1 of the angiotensins. This parallelism was lost when analogs of angiotensin II or III contained valine in position 5. In addition, angiotensin III was found to be less potent than angiotensin II, regardless of the substituent in position 5 (valine or isoleucine).


Evidence for the autoregulation of hormone secretion by prolactin. The cells from the 2B8 clonal strain of pituitary cells which previously have been reported to produce only PRL were incubated with varying amounts of ovine PRL (oPRL) ranging from 0.01--1000 ng/ml. After 1 h, significantly less PRL was measured in culture media from cells incubated with all doses of oPRL employed. This inhibition was dose related. The cells were rinsed five times with Hank's balanced salt solution and subsequently placed into PRL-free media for an additional hour. Hypersecretion of hormone occurred from those cells previously exposed to 1--1000 ng/ml oPRL. The PRL in the media from cells previously exposed to 0.01--0.1 ng/ml was similar to that in the control culture. In some experiments, the cellular concentration of PRL was determined at the end of each of the two 1-h incubation periods. After the initial exposure to oPRL, an increase in intracellular hormone was observed only in those groups incubated with 1--1000 ng/ml oPRL. In contrast, after the cells were rinsed and placed into PRL-free medium, the cellular concentration of PRL was unchanged in all groups except the group previously exposed to 100 ng/ml oPRL. These data indicate that PRL can inhibit its own secretion through direct action on the lactotrophs of the anterior pituitary gland.


Regional differences in response to electrical stimulation within the medial preoptic-suprachiasmatic region on blood luteinizing hormone levels in ovariectomized and ovariectomized, estrogen-primed rats. The effect of electrical stimulation of the medial preoptic-suprachiasmatic nucleus (MPOA-SCN) region of the forebrain on blood LH levels was studied in ovariectomized, pentobarbital-anesthetized rats. Animals were either not primed with estrogen or previously given 5 micrograms estradiol benzoate (EB)/100 g BW . day for the 2 days before stimulation. Rats were bled continuously (30, 40, or 50 microliter whole blood/5--6 min) through indwelling right atrial cannulae for 1.5 h before stimulation, 1.5 h during stimulation, and up to 1 h afterwards. Whole blood was analyzed for LH by RIA. In ovariectomized, unprimed rats, electrical stimulation of the ventral MPOA consistently increased LH release. In contrast, stimulation of the peri-SCN region (immediately caudal to the MPOA, and lateral and dorsal to, but not within, the SCN), uniformly inhibited pulsatile LH secretion. Activation of the SCN elevated blood LH levels in most unprimed rats tested, but suppression of episodic LH release occasionally occurred. Pretreatment with estrogen resulted in increased LH secretion in response to stimulation of each of these three regions. Estrogen prolonged the LH increase occurring during MPOA stimulation, completely reversed the inhibitory LH response to peri-SCN stimulation, and either reversed any possible inhibitory response to SCN stimulation or greatly increased the magnitude and duration of the increase in blood LH levels produced in the unprimed rat during activation of this nucleus. In summary, the present study indicates that well defined areas in the MPOA-SCN region can have strikingly different effects on LH secretion in the absence of ovarian estrogen and that this steroid is critically important in determining the direction, magnitude, and duration of the LH response to a localized brain stimulus.


A human chorionic gonadotropin-specific antiserum against synthetic peptide analogs to the carboxyl-terminal peptide of its beta-subunit. A chemically synthesized Na-acetyl-triacontapeptide analogous to the carboxyl-terminal region (residues 116--145) of hCG beta-subunit was conjugated to bovine thyroglobulin. This synthetic antigen was used to immunize five rabbits; one of these rabbits (H-114) generated a useable antiserum. The binding properties of this antiserum were compared extensively to a well characterized antiserum (H-93) against the natural tricosaglycopeptide (residues 123--145) of desialylated hCG beta-subunit conjugated to bovine serum albumin. The two antisera showed nearly identical immunological specificities and sensitivities when examined in a conventional RIA system. These similarities included: 1) antibody recognition sites residing at the carboxyl-terminal pentadecapeptide region; 2) binding neither [125I]iodo-hLH nor [125I]iodo-oLH; and 3) lack of neutralizing capability against the biological activity of hCG in vivo. However, synthetic pentadeca or longer peptides are twice as potent in inhibiting 125I]iodo-hCG binding to H-114 than to H-93. Synthetic peptides may provide a superior means of generating antisera capable of distinguishing hCG from human LH, since they can be obtained more easily in large quantities than analogous purified natural fragments and because peptides of synthetic origin avoid the risk of contamination from strongly antigenic regions of the native molecules. Such hCG-specific antisera may have extensive application in RIA systems and fertility control, where selective binding to hCG but not human LH is desired.


Blockade of steroid-induced leuteinizing hormone release by selective depletion of anterior hypothalamic norepinephrine activity. Female Sprague-Dawley rats, weighing 200--225 g, were ovariectomized and, 10 days later, were given a single sc injection of 10 micrograms estradiol benzoate/100 g BW. Three days after estradiol benzoate treatment, animals received 50 micrograms progesterone (P)/100 g BW, resulting in a surge in LH release 7 and 9 h later. To determine the locus of the noradrenergic component of the P-induced LH surge, 6-hydroxydopamine (6-OH-DA), a neutrotoxin, was implanted into either the suprachiasmatic region or the median eminence (ME) 24 h before P administration. An implant of 6-OH-DA in the suprachiasmatic region decreased anterior hypothalamic norepinephrine concentration by 83%, anterior hypothalamic dopamine concentration by 24%, and eliminated the P-induced LH surge. ME implant of 6-OH-DA decreased norepinephrine concentration by 57% without affecting dopamine concentration, but was unable to alter the P. induced LH surge. These results indicate that the anterior hypothalamic noradrenergic system is necessary for the P-induced LH surge in ovariectomized rats and that noradrenergic nerve terminals in the ME are not involved in this process.


Further characterization of growth hormone-dependent somatomedin-binding proteins in rat serum and demonstration of somatomedin-binding proteins produced by rat liver cells in culture. The somatomedin-like peptide multiplication-stimulating activity (MSA) binds specifically to rat serum. The pattern of MSA binding is GH dependent. Specific binding of [125I]iodo-MSA in normal rat serum is primarily in the gamma-globulin region (peak II) on Sephadex G-200, while MSA binding in hypophysectomized (hypox) rat serum is near the albumin region (peak III). This study further characterizes the peak II and peak III somatomedin-binding proteins produced by rat liver cells in culture. [125I]Iodo-MSA binding to normal rat serum is abolished by trypsin pretreatment of rat serum, suggesting that MSA binds to protein components of serum. The only detectable somatomedin activity (measured by [3H]thymidine incorporation into chick embryo fibroblast DNA) in fractions of normal rat serum chromatographed on Sephadex G-200 coincides with peak II binding of [125I]iodo-MSA. In hypox rat serum, the majority of detectable somatomedin activity is in the peak III region. There is complete displacement of the human somatomedins [125I]iodoinsulin-like growth factor I and II and [125I]iodosomatomedin A from the rat serum-binding sites by unlabeled MSA, suggesting that the human somatomedins bind to the same sites as MSA. Treatment of normal rat serum with 1 M acetic acid dissociates somatomedin activity from its binding proteins and converts somatomedin-binding proteins from peak II to peak III. Scatchard analysis of competitive binding data using [125I]iodo-MSA yields a binding affinity that is not appreciably different for either normal or hypox rat sera. The binding capacity of normal or acid-treated normal rat serum for MSA is significantly greater than that for comparably treated hypox rat sera. Although the site of synthesis of somatomedin-binding proteins in vivo is unknown, specific somatomedin-binding proteins are synthesized by two rat liver cell lines in culture. These rat liver cell somatomedin-binding proteins have the same molecular size and the same binding affinity for MSA as the peak III somatomedin-binding protein(s) in rat serum.


Metabolism of sex steroids in the human and canine vas deferens. The contribution of the vas deferens to the metabolism of steroids was investigated in the human and in the dog by perfusion experiments and in vitro incubation. Perfusion of testosterone or androstenedione through the canine vas deferens resulted in the formation of dihydrotestosterone; no significant formation of estrogens could be detected. When dihydrotestosterone was perfused, 3alpha- and 3beta-androstanediols were isolated. In vitro incubation experiments with human was deferencs have shown an active metabolism of androgens by this time and, therefore, confer a new role to the vas deferens in the male.


Characterization of the androgen receptor in nuclei of seminiferous tubules of the mature male rat based upon radioimmunoassay of endogenous levels of bound testosterone. A macromolecular testosterone complex which was salt-extracted from nuclei isolated from seminiferous tubules of the adult male rat was investigated by quantifying the testosterone directly by RIA. The steroid-binding capacity of the complex was destroyed by heating at both 12 and 50 C, suggesting the presence of an extremely thermolabile complex. This tubular complex was shown to be similar to the radioactively labeled androgen receptor isolated from ventral prostatic nuclei by their coelution during adsorption chromatography, by their coleution during ion exchange chromatography, their similar migration rate (4-4.46S) on both sucrose and glycerol density gradients, and their similar slow dissociation at 0 C. These observations indicate that the tubular complex contains a high affinity androgen receptor and suggest that the direct measurement of testosterone in this complex by RIA may be useful in identifying its cellular distribution.


Production of 1,25-dihydroxyvitamin D3 and formation of medullary bone in the egg-laying hen. Renal 25-hydroxyvitamin D-1-hydroxylase, the percentage of medullary bone in the femur, plasma calcium, and plasma phosphorus were measured in female chickens reaching maturity. These parameters and plasma 1,25-dihydroxyvitamin D levels were also measured during the daily egg-laying cycle in mature hens. The renal 25-hydroxyvitamin D3-l-hydroxylase becomes elevated in maturing hens before and at the time of ovulation. This elevation in the 1-hydroxylase correlates with the elevation in total plasma calcium concentration but lags and at the time of ovulation and is followed by a further elevation of plasma 1,25-dihydroxyvitamin D levels. The plasma 1,25-dihydroxyvitamin D level remains high until 12 h postovulation. At this time, it falls to the preovulation level. No relationship could be found between the plasma 1,25-dihydroxyvitamin D levels and the changes in medullary bone found during the egg-laying cycle. However, plasma 1,25-dihydroxyvitamin D levels are highest immediately before and during the egg shell calcification phase of the egg-laying cycle.


Hypercalcitoninemia associated with return of serum calcium concentration toward normal in chronically parathyroidectomized rats. In chronically parathyroidectomized male Fischer and Holtzman rats, we found a progressive rise in the levels of serum immunoreactive calcitonin (CT) despite hypocalcemia. The rise was preceded by an increase in the thyroidal CT concentration (determined by RIA) and hyperplasia of C cells (determined by the immunoperoxidase bridge technique). In association with the rise in serum CT, we also observed a return of serum Ca toward normal levels, which the evidence suggests was not due to compensatory regeneration of parathyroid remnants after incomplete parathyroidectomy. It also is unlikely that ectopic parathyroid tissue was responsible for the return of serum Ca toward normal. Since the increase in serum CT after parathyroidectomy coincided with the return of serum Ca toward normal, we postulate that a gradual rise in serum Ca in chronically parathyroidectomized rats might stimulate the "CT-saturated" thyroid glands to release CT, thus leading to a progressive increase in serum CT. Alternatively, it is possible that the increase in serum CT after parathyroidectomy may be due in part simply to nonspecific leakage of CT from the "CT-saturated" thyroid glands.


The importance of proteolysis as the initial step of insulin degradation in rat liver homogenates. It was previously proposed (Varandani, P. T., Proc Natl Acad Sci 69:1681, 1972) that insulin is first degraded by rat liver homogenates in an enzyme-catalyzed reductive process by microsomal glutathione-insulin transhydrogenase before being proteolytically cleaved by the cytosolic enzyme activity designated insulin protease. This study was, however, carried out with concentrations of the hormone 10,000 times the maximal concentration seen in peripheral blood. In the present study, physiological levels of insulin (approximately 0.1 nM) and concentrations of reduced and oxidized glutathione approximating the reductive potentials of normal liver were used. Rates of degradation by separable particulate and soluble components of the homogenate were determined by following enzymatic conversion of [125I]-iodoinsulin to the trichloroacetic acid-solube form. Assessment of the mode of degradation was determined by gel filtration on Sephadex G-50 in the presence of 1 M acetic acid-6M urea. From these studies it was seen that 1) insulin is reduced at a very significant rate nonenzymatically; 2) during short periods of incubation (30 sec) where no significant hormone is reduced nonenzymatically, the rate of cleavage by the insulin protease present in the cytosol is extremely high and the microsomal GIT activity is negligible; and 3) insulin destruction noted in isolated liver cells and perfused liver is most probably due to the insulin protease activity of the cytosol.


Pituitary-brain transport of neurotensin: functional significance of retrograde transport. The ability of the peptide neurotensin (NT) to affect central nervous system function after pituitary-brain transport was examined in adult male rats. Animals were anesthetized and maintained under ether and their pituitaries were exposed by the pharyngeal route. They were then given NT or physiological saline solution by various routes of administration, and colonic temperature (CT) was monitored over a 2-h period. Animals given intracerebroventricular injections of 10 micro g NT showed significantly lower colonic temperatures over the 2-h-measurement period compared to rats injected intraventricularly with the solvent vehicle (0.15 M NaCl). Intrapituitary injection of 10 or 50 micro g NT also markedly decreased CT in a dose-related manner compared to rats given similar injections of the solvent vehicle. Section of the pituitary stalk 24 h before injection of 50 micro g NT into the pituitary totally abolished the hypothermic effect of the peptide. NT in a dose of 50 micro g did not significantly modify CT when injected either iv or into the space between the pituitary and the dura compared to animals given the solvent vehicle. The results suggest that peptides may undergo retrograde transport from the pituitary to appropriate sites in the central nervous system and retain their ability to affect brain function.


Evidence for a role of splanchnic somatostatin in the homeostasis of ingested nutrients. Somatostatin was infused via the portal vein at a rate of 50 ng/min in a group of eight conscious dogs beginning 30 min before and continuing for 6 h after the ingestion of an 800-g fat-protein meal. The fasting and postprandial levels of plasma somatostatin-like immunoreactivity (SLI), insulin, glucagon, and triglycerides were compared with those during an intraportal infusion of saline as a control. In both groups, SLI rose significantly within 15 min of the ingestion of the meal, but during somatostatin infusion, mean peripheral vein levels of SLI ranged from 30-85 pg/ml above those of the saline control experiments. The postprandial rise in plasma triglycerides was reduced significantly below the control values at all points between 75-270 min, and this reduction was the result of lowered chylomicron levels. Neither fasting nor postprandial insulin or glucagon levels were significantly reduced by the somatostatin infusion. Intraportally infused somatostain also reduced portal vein xylose levels after an intragastric xylose load. The results are compatible with, but do not prove, a physiological role for somatostatin in the homeostasis of ingested nutrients.


Somatostatin: central nervous system actions on glucoregulation. Somatostatin (SRIF) has been tested for its actions on the central nervous system to affect glucoregulation. In doses ineffective when given systemically , SRIF and SRIF analogs given intracisternally (ic) reduce hyperglycemia and hyperglucagonemia after ic bombesin administration. The SRIF analog, des-AA1, 2, 4, 5, 12, 13-[D-Trp8]SRIF, decreases plasma insulin and elevates plasma glucose and glucagon when given systemically. However, when given ic, this peptide prevents the rise in glucose and glucagon after ic bombesin administration and is 10 times more potent than SRIF in reducing bombesin-induced hyperglycemia. Other analogs of SRIF and various unrelated peptides were found to be ineffective in reducing bombesin-induced hyperglycemia. des-AA1, 2, 4, 5, 12, 13-[D-Trp]SRIF prevented the hyperglycemia induced by surgical stress or by ic administration of beta-endorphin or carbacol. des-AA1, 2, 4, 5, 12, 13-[D-Trp]SRIF given ic did not prevent hyperglycemia induced by systemic administration of epinephrine, arginine, or glucagon. These studies suggest that SRIF and its analogs may act within the brain to affect glucoregulation.


Hypercalcemic effect of insulin in the chick. There are conflicting reports on the effect of insulin on plasma Ca concentration in rats. Low doses appear to decrease and higher doses to increase plasma Ca. Since birds are known to be very sensitive to parathyroid hormone and have resistance to the hypoglycemic effects of insulin, the effect of commercial and highly purified insulin on plasma Ca concentration was studied in 10-day-old chicks 60 min after the administration of the hormone. Both commerical bovine and purified porcine insulin provoked a dose-related elevation of plasma Ca. Although hypophosphatemia was observed with the highest dose of insulin used (0.4U), hypercalcemia was observed with 0.05 U insulin, a dose that did not modify plasma phosphate concentration. The slopes of the dose-response curves of insulin and parathyroid hormone were indistinguishable and different from that of 1 alpha-hydroxyvitamin D3. Neither propranolol nor deprivation of vitamin D altered the hypercalcemic response to insulin. Unexpectedly, propranolol (40 microgram/chick) provoked elevation of plasma Ca. It is concluded that insulin raises plasma Ca concentration in the chick by a mechanism(s) not yet elucidated.


In vivo 24-hydroxylation of 25-hydroxyvitamin D3 in enterocolectomized rats. To determine if the renal 25-hydroxyvitamin D3 24-hydroxylase is active in addition to the intestinal 25-hydroxyvitamin D3 24-hydroxylase in vivo in the rat, radiolabeled 25-hydroxyvitamin D3 was administrated to normocalcemic, vitamin D-replete, enterocolectomized rats. Substantial amounts of 24,25-dihydroxyvitamin D3 were detected and the identity of the isolated plasma 24,25-hydroxyvitamin D3 region in these animals were confirmed by coelution on high pressure liquid chromatography and periodate cleavage. This suggests that both intestinal and renal 25-hydroxyvitamin D3 24-hydroxylases are active in vivo in the rat.


Acute hyperinsulinemia and its reversal by vagotomy after lesions of the ventromedial hypothalamus in anesthetized rats. The acute effect of bilateral electrolytic ventromedial hypothalamic lesions (20-25-m Coulomb stainless steel electrodes) on plasma levels of insulin and glucose was studied in anesthetized rats to determine early effects that would occur before hyperphagia and obesity. In rats fed ad libitum, lesions in the ventromedial hypothalamus (VMH) but not in the cortex produced a marked increase in circulating insulin levels (starting at 20 min postlesion) and a small increase in glycemia which, however, was not significant and could therefore not be the cause of increased insulin secretion. Hyperinsulinemia after VMH lesions was more pronounced when glucose was infused iv at a rate of 7-8 mg/kg . min. Bilateral subdiaphragmatic vagotomy, performed 50 min after VMH lesions, immediately and completely reversed the observed hyperinsulinemia. With the exception of a tendency of lesions producing the highest degree of hyperinsulinemia to be slightly larger than the lesions not producing any hyperinsulinemia, no statement about the critical involvement of a specific hypothalamic locus can be made. It is concluded that electrolytic VMH destruction causes immediate hypersecretion of the pancreatic B cell, an effect that requires the integrity of the vagus nerves. Further localization of the central circuitry responsible for this mechanism, however, will require more specific methods than electrolytic lesions.


Enhancement of parathyroid hormone-stimulated bone resorption by poly-L-lysine. Poly-L-lysine (PL II; mol wt, 1000-4000) was added to fetal rat bones cultured in a chemically defined medium (BGJ) containing bovine serum albumin in the presence and absence of parathyroid hormone (PTH). Bone resorption was measured by the release of previously incorporated 45Ca. The addition of PL II at concentrations of 3-100 microgram/ml enhanced the stimulation of bone resorption by submaximal doses of PTH but had little effect on 45Ca release from control unstimulated cultures. Higher concentrations of PL II produced inhibition of 45Ca release. Dialysis of PL II did not alter enhancement or inhibition by PL II. PL II did not increase sensitivity to PTH in serum-supplemented cultures. Higher molecular weight PL II preparations were less effective. PL II did not enhance the resorptive response to 1,25-dihydroxyvitamin D, prostaglandin E2, osteoclast-activating factor, or bacterial endotoxin. The mechanism of the selective ability of PL II to enhance the response to low concentrations of PTH is unknown but may be due to the ability of this basic polypeptide to interfere with binding of PTH to sites other than the hormone receptor or to block degradation of PTH by bone.


Developmental patterns of the testicular response to experimental modifications of circulating androgen levels in the fetal rabbit. The circulating level of free androgens in fetal and newborn rabbits was reduced by active immunization of mothers against testosterone (T) or was increased by injecting dihydrotestosterone (DHT) into the mothers. After immunization, about 100% of the circulating T and DHT in fetuses was bound. After maternal injection of DHT, the circulating level of this hormone in fetuses was increased 2- to 120-fold. The effects of these treatments were evaluated by determining testicular levels of T, a physiological index of circulating gonadotropin. From 20--23 days of gestation, testicular T content was modified neither by circulating antibodies nor by an increase of blood DHT. The same overloads of circulating DHT, which were ineffective between 20--23 days, significantly reduced testicular T content between 25--29 days. Testicular T content was significantly increased in newborns from immunized mothers. These results suggest that the appearance of the negative feedback action of circulating androgens takes place relatively late, at 24 or 25 days, after differentiation of the genital tract.


Tumor growth and calcitonin during serial transplantation of rat medullary thyroid carcinoma. We have recently reported immunochemical methods for the measurement and purification of rat calcitonin (CT). To identify a convenient source of CT-producing cells for studies of rat CT biosynthesis, we have propagated 16 transplantable series of medullary thyroid carcinoma (MTC) from 2 types of WAG/Rij rat MTC from The Netherlands. Tumor CT concentrations and growth and plasma CT accumulation were studied in successive transplant generations of each MTC series. Although most MTC series maintained characteristic predictable tumor CT levels, some MTC series acquired nearly 90% lower CT levels. While related MTC series tended to maintain similar predictable growth rates, several spontaneous and propagatable increases (up to 5-fold) in tumor growth rates were noted. These increases occurred with and without concomitant decreases in tumor CT. Tumor CT production ranged over 20-fold among these 16 MTC series. Serial plasma CT analyses can be used to estimate tumor growth and CT production in live MTC rats. Using serial plasma CT analyses, we can select for serial transplantation tumors with specific growth and CT characteristics. This should facilitate propagation of MTC series needed for particular studies of CT production and cancer.


Stereoselective inhibition of aromatase by enantiomers of aminoglutethimide. The dextrorotatory enantiomer of aminoglutethimide is 38 times more potent than the levoenantiomer in inhibiting aromatization of testosterone by human placental microsomes. The spectral affinity constant for microsomal cytochrome P-450 is 36 times greater for the d-enantiomer. Enzymatic inhibition and affinity are highly correlated for each of the isomers as well as for the racemic mixture. Spectral analysis of the interactions of the inhibitors with the substrate supports the evidence for participation of cytochrome P-450 in aromatization.


Relationships among placental, uterine, and circulating concentrations of progesterone and fetal survival in the ovariectomized pregnant rat. Pregnant rats were ovariectomized or sham operated on day 15 postcoitum. Four days later, progesterone was measured by RIA in peripheral and uterine vein plasma, in uteri, and in placentae. Maintenance of pregnancy was not critically affected by ovariectomy, since fetal survival was 65.7 +/- 5.1% (mean +/- SEM) despite a large decrease of peripheral plasma progesterone from 115.7 +/- 3.4 to 9.3 +/- 0.5 ng/ml. Peripheral and uterine vein plasma progesterone (8.3 +/- 0.9 ng/ml) were identical. In contrast, placental progesterone decreased only slightly, although significantly, from 27.3 +/- 1.3 to 20.3 +/- 1.0 ng/mg. The concentrations of uterine progesterone were variable and positively correlated with the concentrations of peripheral plasma progesterone. It was concluded that uterine progesterone originates from peripheral blood but not from placentae and that fetal survival is positively correlated with residual progesterone concentrations in peripheral plasma and in uterus but not in placentae.