Gastrointestinal therapeutic system for acetazolamide. Efficacy and side effects. Acetazolamide has been formulated in a new gastrointestinal therapeutic system that delivers the drug at an essentially constant rate of 15 mg/hr (GITS 15/125). We compared the therapeutic effect, magnitude of plasma concentration fluctuations, and incidence of side effects produced by the GITS 15/125 with conventional 250-mg acetazolamide tablets on eight glaucomatous patients randomly assigned to a different regimen each week. One or two GITS 15/125 twice a day (bid) were found as effective in reducing intraocular pressure as one 250-mg acetazolamide tablet. Plasma concentration fluctuations with the GITS 15/125 were decreased, compared with acetazolamide tablets, and, as a result, the incidence of drowsiness, tingling feet, tingling hands, and confusion was substantially reduced.


Argon laser iridotomy on primary angle closure or pupillary block glaucoma. Scanning and transmission electron microscopy were performed on peripheral iridectomy specimens from seven patients with failed pulsed argon laser iridotomies. Four to seven hours after the laser, severe edema, coagulation necrosis, focal vascular occlusion, and hemorrhage were present. Five days after the laser, cell detritus and collapsed cell processes were noted. Forty-two days after the laser, the anterior iris surface appeared considerably thinned and irregular. Eight and one-half months after the laser, the burn site displayed a dense matted appearance. Two years after the laser, the anterior iris showed a depression with pigment dispersion, irregular stroma, and disruption of the dilator muscle. The lack of inflammation could be due to the use of pulsed argon laser heat delivered at very short intervals, with deep penetration and minimal heat dispersion, since the beam is highly collimated.


False-positive 32P uptake tests.

False-positive 32P uptake tests. Three patients had suspected choroidal melanoma and positive results for radioactive phosphorus (32P) uptake tests, leading to enuclearion in two of the patients. No malignancy was present on histopathologic examination. This experience reemphasizes the need for the ophthalmologist to evaluate the total clinical picture and not to give inappropriate consideration to a "positive" 32P uptake test in deciding for or against enucleation in a suspected choroidal melanoma. The positive 32P uptake test, even with high values, cannot be equated with malignancy, and a variety of nonmalignant lesions may give false-positive results.


Adenocarcinoma of the retinal pigment epithelium. A 57-year-old woman complaining of decreased vision for six months had a mass expanding the choroid inferonasally in the right eye. Clinical examination, ultrasonography, and fluorescein angiography were consistent with a malignant melanoma. The eye was enucleated and pathologic studies showed an adenocarcinoma of the retinal pigment epithelium (RPE). Malignant tumors of the RPE may simulate exactly choroidal melanomas clinically, but apparently have a much better prognosis, in that very few cases have been documented to produce metastatic disease. The vast majority of cases studied histopathologically, in which a diagnosis of adenocarcinoma of the RPE has been made, are low-grade malignant neoplasms with the absence of invasion beyond the choroid or lamina cribrosa at the time of enucleation.


Mucogenic glaucoma and goblet cell cyst of the anterior chamber. A 25-year-old woman had a unilateral open-angle glaucoma that was initially thought to be caused by an anterior uveitis. A deformity of the chamber angle was noted and interpreted as a peripheral anterior synechia or an old scar. A peculiar haze was noted in the anterior chamber. The intraocular pressure was controlled by trabeculectomy. A slowly enlarging cyst was observed at the site of a previous anterior synechia. Excision of the cyst resulted in clearing of  the anterior chamber haze. The second trabeculectomy specimen contained mucous strands. Problems exist, both clinically and histopathologically, in diagnosing and managing this rare form of secondary glaucoma (mucogenic glaucoma).


Experimental Bacteroides fragilis keratitis. To determine the corneal pathogenicity of certain anaerobic bacteria, Bacteroides fragilis keratitis was induced in rabbits by the intrastromal inoculation of 10' viable organisms. All eyes inoculated developed central abscesses within 24 hours. Abscesses persisted and became vascularized in two of three eyes that were observed for two weeks, as demonstrated both clinically and histologically. Eyes inoculated superficially with live organisms or intrastromally with solutions of dead organisms did not develop inflammatory lesions. Anaerobically incubated blood agar plates and thioglycollate broth were equally efficient in recovering organisms, although longer incubation times were occasionally necessary to recover organisms from broth cultures. Bacteroides fragilis and other anaerobic bacteria should be considered in the differential diagnosis of bacterial keratitis, and specific methods should be used to recover these organisms.


Traumatic retinopathy in primates. The explanation of commotio retinae. We have produced experimental commotio retinae in 12 owl monkeys by blunt trauma. The ophthalmoscopic and fluorescein angiographic appearance of this contrecoup lesion is identical to the acute traumatic retinal opacity in humans. We examined these eyes by light and electron microscopy from 4 hours to 12 weeks after injury. Immediately after injury, the only abnormality is disruption of the receptor outer segments. From one to six days after trauma, many receptor cells undergo degeneration. The retinal pigment epithelium phagocytoses the degenerating outer segments, occasionally migrating into the retina. There is no extracellular retinal edema. The opacity of commotio retinae seems to represent disrupted receptor cells. Visual loss may result from permanent loss of receptors. The pigment epithelial response to traumatic receptor damage is similar to that observed in experimental retinal detachment and light-induced retinal damage.


Cochlear nerve in neurilemomas. Audiology and histopathology. Correlative data between the histopathologic changes in the cochlear nerve and audiologic findings are reported in 16 cases of neurilemomas. Poor speech discrimination, positive or absent recruitment, excessive adaptation, or separation of forward vs reverse continuous tone Bekesy tracings did not correlate with the number of preserved nerve fibers. There were several cases with profound hearing loss in which the nerve fiber population approached normal. Histologically, pathologic changes included dilated fibers and increased interfibrillary collagen. In many specimens the fibers were further apart than normally, especially in the immediate vicinity of the tumor, and many lay between tumor cells. The tumor-nerve interface was usually gradual and no abrupt change appeared at the transition from the nerve to the tumor, the Schwann cells appearing to continue as tumor cells. Nonspecific changes apparently due to specimen handling were seen in some areas of most specimens.


Design and testing of a new electrode for laryngeal electromyography. Electromyography of the intrinsic laryngeal muscles has not been widely used, partly because of the difficulty of accurate insertion and stabilization of existing electrodes. The sampling portion of our original electrode has been redesigned. Two needle electrodes, 4 mm in length, protrude from a truncated coneshaped, nonconducting body that has been fashioned to sit in the laryngeal ventricle. The depth of insertion is controlled, and the device resists accidental extrusion.


Sinus histiocytosis with massive lymphadenopathy. Sinus histiocytosis with massive lymphadenopathy (SHML) is a newly recognized, distinct, pseudolymphomatous benign entity with very characteristic microscopic features. Most patients are children or young adults with massive painless cervical adenopathy, although other node groups and extranodal sites often are involved. Sixteen patients with SHML involving the upper respiratory tract and/ or salivary gland are presented. Nine of the patients had ear, nose, and throat (ENT) manifestations at the time of presentation. In most cases the ENT involvement resulted in prominent clinical symptoms. Treatment included surgery, antibiotics, irradiation, chemotherapy, and steroids, frequently in combination, but no consistent pattern of response emerged from the study. These 16 patients were very similar clinically to patients with SHML who did not have ENT disease, indicating that extranodal involvement is not associated with more aggressive disease.


Unidirectional inner ear valve implant for endolymphatic sac surgery in Meniere's disease. In five patients with long-standing Meniere's disease, a unidirectional inner ear valve was implanted into the endolymphatic sac (ELS) to facilitate removal of excess endolymph in the hydropic state. These patients were all candidates for ablative surgery. They all had intractable vertigo and severe hearing losses. Four out of five patients had positive preoperative glycerol tests. In the patients with positive glycerol tests, the group averages before surgery were as follows: pure-tone average (PTA), 63 dB; speech reception threshold (SRT), 79 dB; and discrimination score, 27%. All of the patients, except a patient with a negative glycerol test, benefited from the surgery, including exceptional hearing improvements, averages of 21 dB in PTA, 30.5 dB in SRT, and 48% in discrimination, which remained so for at least a one-year minimum follow-up. All patients with preoperative positive glycerol tests had a class A result according to the criteria set forth by the American Academy of Ophthalmology and Otolaryngology. The cumulative follow-up exceeded the minimal requirements by a factor of 39 times. The only failure was in a patient with a negative glycerol test, which was predictable. Results of tomography confirmed the correct position of the valve without evidence of migration or extrusion even in the failure. This new valve appears to be a safe and more effective implant than Silastic sheeting alone or any other ELS implant in patients with a positive glycerol test.


Cervicofacial actinomycosis.

Cervicofacial actinomycosis. Actinomycotic infections are unusual, but the actual incidence is likely to be significantly higher than records indicate. The disease may complicate trauma of many types to the respiratory and digestive tracts, including operative procedures. This possibility should encourage more frequent use of anaerobic cultures in inflammatory diseases, particularly posttraumatic, and should prompt consideration of actinomycosis in the differential diagnosis of infections, especially in the cervicofacial area. We report four cases that demonstrate the variable course of this infection. Treatment is highly successful with appropriate use of antibiotics and surgery. A plea is made to use the least expensive, effective antibiotic in view of the prolonged course of therapy that is necessary to eradicate this infection.


Human auditory nerve action potentials and brain stem evoked responses. Latency-intensity (L-i) functions for (1) the auditory nerve action potential (AP) N1 peak, (2) the brain stem evoked response (BER) V peak, and (3) the N1-V interval were related to hearing level and lesion location. The AP L-l curves tended to steepen with increasing 4 to 8 kHz hearing level. This relationship was identical for cochlear and retrocochlear ears, except for a few retrocochlear ears with "inappropriate AP perservation." Both high-frequency cochlear loss and retrocochlear abnormality prolonged peak V latency, but retrocochlear abnormality generally prolonged it more. Among cochlear-loss ears, as 4 to 8 kHz hearing levels increased, N1-V intervals decreased and L-i curve slopes increased. In contrast, retrocochlear abnormality greatly prolonged N1-V intervals. As a retrocochlear sign, N1-V prolongation was slightly more reliable than V prolongation.


Otolaryngologists and their surgical practice. Practice characteristics of otolaryngologists, studied as part of a national survey of surgeon manpower, are compared with those of other surgical specialists. Otolaryngologists had relatively short workweeks and spent more professional time in their offices than in hospitals compared with other surgeons. Their California relative value (CRV)-weighted surgical work load ranked eighth among all surgeons. Although otolaryngologists performed, on the average, more operations annually than did other surgical specialists, their procedures were generally less complex (low CRV weights). The per capita rate for tonsillectomy, the procedure that comprised more than one third of the weighted work load of otolaryngologists, has declined precipitously. The conclusion drawn from this study is that a reduction in the number of trainees in otolaryngology would be in the best interest of the young and other otolaryngologists whose capabilities are now seriously underutilized.


The ototoxic potential of propylene glycol in guinea pigs. Propylene glycol, previously indicated to be ototoxic and to produce "deafness," was studied in the middle ear space of guinea pigs. Ninety percent propylene glycol produced conductive middle ear problems, but there was no loss of hair cells above that found in normal untreated animals. Ten percent propylene glycol produced no negative effects in the middle ear or elsewhere. Topical ear drops containing high concentrations of propylene glycol are contraindicated in cases with perforation of the tympanic membrane.


Design and testing of a transistorized nerve stimulator. Presently available equipment for nerve stimulation includes the relatively expensive multifunction pulse generators and the disposable dc stimulators. We have designed a semidisposable, two-transistor pulse generator that is portable, inexpensive, and capable of dynamic nerve stimulation.


Factors influencing use of hearing aids. A follow-up questionnaire was mailed to new hearing aid users. The questionnaire responses of 430 persons, 73% of the sample, were related to age, audiometric, and hearing aid evaluation data obtained at the time of fitting. Reported usage of the aids was also analyzed in terms of the type of fitting and according to length of postfitting training. Further, the reasons for limited or nonuse were tabulated. The population in the present study, in comparison with that of previous investigations, was characterized by relatively young age and predominantly noise-induced, sensorineural type hearing loss, with mild hearing loss for speech; these factors led to a high proportion of selective amplification fittings. Reported overall use did not differ among the types of aids. Overall use declined with increasing age, and the majority of persons in this population used their aids selectively rather than on a full-time basis. Length of postfitting training appeared to increase hearing aid use. Mean audiometric and hearing aid evaluation data remained relatively constant across four usage categories: "always," "often," "occasionally," and "never." Excessive background noise and lack of need constituted 63% of the reasons given for limited use or nonuse.


Voice, speech, and language habilitation in young children without laryngeal function. We discuss aphonia in children, secondary to laryngeal obstruction, with regard to the development of a voice, speech, and language system that can be an effective and efficient means of communication while obstruction persists and a precursor to good voice and speech habits if and when the laryngeal function is reestablished. Several methods were considered. A technique of esophageal voice training for children was developed and implemented, which combined the aspects of normal language learning with the mechanical aspects of esophageal voice production. Results showed rapid learning in a 2 1/2-year-old child with severe juvenile laryngeal papillomatosis and normal speech and language at the age of 4 years when laryngeal function returned. A second technique, a communication board, was used with a 4-year-old child with total subglottic stenosis and brain damage.


New magnifying laryngeal and nasopharyngeal mirrors. Indirect laryngoscopy and nasopharyngoscopy have been a part of every routine examination by the otolaryngologist and others who choose to use this technique. However, some early lesions of the nasopharynx and laryngopharynx are not detected by the naked eye through the plain mirror. New magnifying laryngeal and nasopharyngeal mirrors are described, which help to visualize the small lesions of the larynx and nasopharynx more easily.


Development of early auditory-evoked responses in the cat. The post-natal development of the auditory-evoked responses to 1- and 4-kHz tone bursts has been studied in the cat with subcutaneous electrodes and signal-averaging techniques. A cochlear microphonic response antedates the earliest appearance of brain stem potentials by 1 or 2 days, and can be recorded in some animals on the first post-natal day with the 4-kHz stimulus. The earliest brain stem response consists of three or four low-voltage waves,which increase to six in the 2nd week. Latency shortening and amplitude growth occur for all waves, but are most pronounced in the later part of the response. The characteristics of the summating potential, and the variable influence of rate effects on wave amplitude are described for the different age-groups.


Cochlear initiation site of the frequency-following response: a study of patients with sensorineural hearing loss. The cochlear initiation of the frequency-following response (FFR) was assessed by comparing the FFR thresholds to the pure-tone thresholds in four groups of patients suffering from different forms of sensorineural hearing loss. The groups consisted of patients suffering from (1) pure high-frequency hearing losses; (2) high-frequency hearing losses mixed with moderate low-frequency losses; (3) flat hearing losses, and (4)low-frequency hearing losses. Across groups, the pattern of thresholds of the FFR evoked by 500-Hz tome bursts paralleled the pattern of pure-tone thresholds only for the low frequencies- not the high frequencies. In order to clarify the interpretation of this result, a high-pass masking experiment was performed on patients with low-frequency hearing losses. High-pass masking noise did not affect the FFR thresholds to 500-Hz tone burst, but it produced a phase shift of the FFR at stronger intensity levels. The data are interpreted as strongly supporting the view that the FFR at low levels is initiated primarily by activity in the apical portion of the cochlea.


Genetic counselling.

Genetic counselling. This article outlines the modes of inheritance of genetic disease, its risk of recurrence and the information the doctor needs in order to give accurate genetic counselling. Consideration also is given to the role of environmental factors in producing congenital defects. Suggestions are made as to how parents can be given the most reliable and humane help in understanding such conditions.


Rehabilitation of, and services for the blind in Australia. The services available to blind people in Australia are many and varied. This article attempts to explain the broad range of facilities that are available for all age groups.


Effects of number and interstimulus interval of tone pips on fast responses. Effects of stimulus number and interstimulus interval on auditory-evoked fast responses (BSR: Jewett's V, and middle-latency components: Na, Pa and Nb) were studied by using 1000- and 500-Hz tone pips in 6 normal human adults. At a stimulus intensity of 50 dB SL, 500 stimuli evoked BSRs and the middle-latency components in all cases. At a stimulus intensity of 30 dB SL, 1000 stimuli were necessary to evoke BSRs and Na in all 6 subjects. Even 4000 stimuli were not sufficient for identifying Pa in 1 subject and Nb in 3 subjects. The largest mean peak-to-peak amplitude was the Na-Pa amplitude, but, differences across subjects were large. On the other hand, the BSR-Na amplitude showed relatively small differences across subjects. The BSR latencies were highly stable across subjects. These characteristics indicate that the BSR-Na component is more suitable as an indicator for objective audiometry than either the Na-Pa or Pa-Nb component. The BSR-Na amplitude did not show a decrease as the interstimulus interval was decreased from 104 to 32 ms. On the other hand, the Na-Pa amplitude significantly decreased as the interstimulus interval was decreased from 104 to 42 ms, and the Pa-Nb amplitude also significantly decreased as the interstimulus interval was decreased from 104 to 73 ms. Therefore, because of its resistance to the effects of high rates of stimulation, the BSR-Na component appears to be a suitable audiometric index in the clinical situation where time constraints are a consideration.


Distribution of brain stem responses to acoustic stimuli over the human scalp. Responses to acoustic stimuli are generated in neurons of nuclei on both sides of the brain stem. In order to determine whether there are electrode positions which can be used to record activity predominantly generated in the neurons of nuclei of one side, the distribution of brain stem responses to acoustic stimuli over the human scalp was investigated. The response is found to be maximum at the vertex, and diminishes gradually toward the nasion, inion and the mastoid process. There are no significant differences between responses to ipsi- and contralateral stimulation. It follows that there are no electrode positions, which can be used to record the activity generated in the neurons of nuclei of one side. There are, however, indications that monolateral pathology of brain stem nuclei may be detectable by comparing responses to stimuli presented on the right, the left and bilaterally.


Psychiatric consultation: the patient, the doctors and their letters. Letters to psychiatrists by general practitioners are the main method of communication between doctors when a patient is referred. This study has been of critical data from the letters to the psychiatrists, and an analysis of the information from the psychiatrist to the general practitioner. Improvements are necessary in this field so the patient can receive optimal care.


Cross-modal matching of loudness and brightness as a recruitment test for hearing-impaired children. Normal 5-year-olds have been reported to be able, in a simple game situation, to match brightness to loudness in the same way as a control group of adults. This study investigated supplanting the normal ear in an alternate binaural loudness balance test (ABLB) with the visual modality, as a recruitment test designed especially for bilaterally hearing-impaired children. The results of normal 10-year-olds, with simulated hearing losses, suggest that category scaling was adopted naturally as a simplifying strategy in preference to ratio scaling (absolute judgements). No proportional increase in the matching function slope was evident, despite the amount of recruitment measured with an ABLB. The instructions needed to combat this strategy render the test unfeasible with hearing-impaired children.


Simultaneous four-channel electric-response audiometry results in 8 years of hearing evaluation among small children. The results of 8 years' experience with slow cortical-evoked responses obtained by a four-channel method are reported. The conclusion is that, even in this form, ERA is not a reliable tool for diagnosing hearing defects in children. The time course of the mean ERA threshold of 138 children examined in Turku University for periods ranging from 6 months to over 3 years is presented. The results are discussed. Electrocochleography or brain stem audiometry is recommended for clinical use.


Early Childhood Development Programme--early detection. The Early Childhood Development Programme has four main objectives. These are: 1. To foster child development in families with young children largely through personal involvement of the family in an education context. 2. To provide enrichment programmes to enrich the social, emotional and physical environment and to ensure that children with special needs have these needs met optimally. 3. To provide for the early detection of children who are more vulnerable because of the presence of a condition which may tend to limit optimal development and make the child more open to adverse influence of social or cultural pressures; that is a health assessment programme. 4. To provide a family support service for families of children with special needs to enable these families to foster and to fulfil themselves in the society in which they live. This family support service is seen as providing a structure for home centred parent/infant habilitation aimed at keeping the family in the main stream insofar as education and health are concerned.


The practical management of the patient who complains of erectile impotence. Erectile impotence is a common complaint, and competent management demands a systematized approach to diagnosis and treatment. The purpose of this article is to offer a practical schema for evaluating and treating a patient who presents complaining of this difficulty.


Evaluation of primary health and medical care: the current state of the art. Evaluation is a subjective process which depends upon the perspective of the evaluator and the criteria he chooses. A review of past efforts at primary care evaluation indicates a preoccupation with the structure and process of care. Methods for the measurement of the outcome of primary care are at last being developed.


The recognition and treatment of the irritable bowel syndrome. The irritable bowel syndrome (IBS) is characterized by abdominal pain and/or altered bowel habit in the absence of detectable organic bowel disease. By convention, people with simple constipation are not usually included in this group of patients. IBS is a symptom-complex with many synonyms such as irritable colon, functional bowel disorder, nervous diarrhoea or spastic colon.


Self-hypnosis training in anxiety reduction. Twenty three adult patients with problems of anxiety in a suburban general practice were invited to participate in a study to determine the effectiveness of self-hypnosis training in reducing anxiety levels. In an initial interview (T1), Experimenter 1 gave subjects two C-60 cassette tapes for home use. These contained the voice of Experimenter 2 who was unknown to the subjects, instructing them in self-hypnosis. After six weeks (T2), measures by Experimenter 1 of both psychological anxiety and blood pressure showed significant reduction (with the exception of systolic blood pressure), and in some cases subjects reduced their anxiolytic medication. A follow-up nine months later of as many subjects as were available (12) showed that these desirable effects were still detectable to a significant degree. It is suggested that audiotaped training in self-hypnosis represent a valid non-pharmacological method for anxiety reduction.


Inherited pyruvate kinase deficiency and normal haematologic values in Australian Basenji dogs. We have carried out a survey to determine the prevalence of carriers of pyruvate kinase deficiency haemolytic anaemia in Basenjis in Victoria. Of 186 dogs tested, 20 were found to be carriers for pyruvate kinase deficiency, a prevalence similar to that reported overseas. Of the 20 carriers found, 17 were born in Australia and were traced directly to 1 of the 3 imported carriers. Despite the relatively high frequency of carriers, no mating of 2 carriers has yet been detected and no dogs with haemolytic anaemia have been observed. The inheritance of the pyruvate kinase deficiency has been traced through up to 5 generations of dogs in Australia and is consistent with co-dominance for pyruvate kinase activity and with an autosomal recessive gene for haemolytic anemia.


A survey of antibody to Aino virus in cattle and other species in Australia. A serological survey of healthy cattle in Australia showed that antibodies to Aino virus were present in serums from cattle in northern Australia and down the east coast as far as central New South Wales in 1975, 1976 and 1977, but occurred with a lower frequency than antibodies to Akabane virus. In contrast to the findings with Akabane virus, no neutralising antibodies to Aino virus were detected in serums from camels, dogs or horses. Antibodies to both viruses were detected in buffaloes and sheep, but not in humans or any of the Australian indigenous species so far tested. All positive serums originated from within the known range of Culicoides brevitarsis.


Immunity to experimental staphylococcal mastitis--comparison of live and killed vaccines. Eleven pregnant Merino ewes were immunised with either a killed Staphylococcus aureus cell-toxoid vaccine (intramuscularly) or a living culture of the same organism (subcutaneously). A further 3 animals were used as non-immunised controls. There were no significant differences between the vaccinated groups for agglutinating antibody to staphylococci or for anti-alpha-haemolysin in either serum or whey. Three weeks after lambing the ewes were challenged by intramammary infusion of virulent staphylococci. All animals developed an acute mastitis with significant decreases in milk yields being recorded 48 hours post-challenge. Seven days after challenge the mean milk production of ewes given the live vaccine had recovered to within 5% of the pre-challenge mean yield. However, milk productions of controls and ewes given the killed vaccine had further decreased and were significantly lower than for animals vaccinated with live staphylococci. There were no significant differences between the two vaccinated groups for numbers of bacteria or leucocytes in milk samples collected after challenge. The ewes were killed 7 days post-challenge and mammary tissues were examined for immunoglobulin-containing cells. Large numbers of IgA-containing cells, and few IgM-containing cells were found, but there were no significant differences between the treatment groups for these parameters.


Response of cattle to inoculation with atypical mycobacteria of bovine origin. Ten strains of atypical mycobacteria originally isolated from cattle were inoculated into cattle. Each strain was injected subcutaneously into one animal and into a mesenteric lymph node of another. Four weeks and 10 weeks after inoculation the cattle were tuberculin tested with bovine PPD, avian PPD and appropriate homologous PPD. Three strains produced a significant level of sensitivity to bovine PPD at the 4-week test but by the 10-week test no animal gave a significant response. The sensitivity to all tuberculins was less at the 10-week test than at the 4-week test. At both tests the response to avian PPD was equal to or exceeded that to bovine PPD. Of 4 strains originally from cattle sensitive to mammalian tuberculin only 2 produced sensitivity of bovine PPD in this experiment. Cultural isolation of mycobacteria from necropsy material was correlated neither with sensitivity to bovine PPD nor with the presence of lesions.


Toxicity of Leucaena leucocephala. The effect of iodine and mineral supplements on penned steers fed a sole diet of Leucaena. Steers fed a sole diet of Leucaena leucocephala cv. Peru (leucaena), rapidly developed a hypothyroid condition. Total serum thyroxine (T4) levels declined from c 120 n mol litre-1 to 13 n mol litre-1 within six weeks of full leucaena feeding. Associated with the hypothyroidism was a declined in feed intake, poor weight gain, hair loss, excessive salivation and the development of lesions on the oesophagus of some animals. Light steers (119 kg) were more severely affected than heavy steers (220 kg) and two light steers died. During the eight week period of full leucaena feeding animals gained only 0.18 kg head-1 day-1 compared with 0.73 kg head-1 day -1 for steers fed cowpea (Vigna sinensis) hay. Supplementation with minerals (Fe, Cu, Zn) significantly increased mean daily intake (85.4 v 68.9 g/kg0.75), daily liveweight gain, (334 v 14 g), and serum T3 resin uptake (42.5 v 39.6%); decreased hair loss and skin lesions but did not alleviate the low serum T4 levels. Iodine supplementation did not affect intake, bodyweight gain, serum T4 levels, serum T3 uptake or toxicity scores compared with unsupplemented leucaena fed steers. When the leucaena fed animals were subsequently fed cowpea hay, appetite improved and the serum T4 levels returned to normal within two weeks. For the heavy steers over this period, weight gain was similar to the controls; however, the light steers continued to gain poorly.


Evaluation of tests for the diagnosis of lead exposure in sheep. Several laboratory tests that are currently used for the diagnosis of lead poisoning in man were evaluated for the detection of lead poisoning in sheep given 3 or 10 mg Pb/kg body weight/day for 7 weeks. Urinary porphyrins and basophilic stippling of erythrocytes were not sensitive indicators of lead poisoning in sheep, while urinary lead and urinary delta-aminolevulinic acid concentrations were too variable to have diagnostic value. However, erythrocyte delta-aminolevulinic acid dehydratase was strongly inhibited by exposure to relatively low doses of lead, while blood lead concentrations gave an indication of the level of exposure to lead poisoning.


Comparison of diving bradycardia and maximal aerobic power. It has previously been suggested that diving bradycardia might be more pronounced in physically trained subjects than in unconditioned ones. Therefore, the cardiac responses to apneic face immersion in water of 25 +/- 1 degree C during rest and exercise in 24 males and females, ranging in age from 21-37 years, were compared to the subjects' levels of physical fitness, as estimated by maximal aerobic power. These values ranged from 46-74 ml.kg-1.min-1. The diving bradycardia was greatly intensified when the face immersion was superimposed on a state of apneic exercise. However, a correlation of the individuals' maximal aerobic power and the mean degree of bradycardia displayed during various maneuvers of apneic face immersion did not approach statistical significance. It is concluded that there exists no relationship between bradycardia and physical fitness, as judged from maximal aerobic power.


Voluntary movement control and adaptation to cross-coupled stimulation. The rates at which protective adaptation was acquired to an incremental cross-coupled stimulus were compared under three conditions of movement control: 1) a passive condition in which the 45 degree lateral tilts of the subject's chair were controlled entirely by the experimenter (N = 12); 2) an active condition in which the same movements were achieved directly through the subject's own muscular effort (N = 12); and 3) an active-passive condition in which control was exercised indirectly through microswitches located on the chair arms (N = 12). Adaptation was measured by the rate of neutralization of the oculogyral illusion, as estimated from the apparent motion of a small, dimly illuminated target. The results supported the prediction that the passive condition would be the least effective mode for acquiring adaptation. An unexpected finding was that the active-passive condition proved to be the most efficient for the development of adaptation.


Motion sickness susceptibility: a retrospective comparison of laboratory tests. A test battery designed primarily to assess vestibular function has been used for several years to evaluate individuals referred to our laboratory. Because some of the test conditions have proved to be nauseogenic to some individuals, methods of assessing disturbance during these procedures have been used to pursue a second goal, viz., the estimation of motion sickness susceptibility. This report, which focuses on the latter goal, is a retrospective comparison of results on three tests obtained from two groups of subjects, one of which was a group of Navy and Marine aviation personnel who had suffered multiple attacks of airsickness. Results from three laboratory tests of motion sickness susceptibility indicated that there are substantial differences between the airsick group and the unselected comparison group on observer ratings and individual self-ratings of motion sickness symptoms. The provocative stimuli in each laboratory test, as well as suggestions concerning how multiple tests may prove effective in predicting motion sickness, are discussed.


Core temperature measurement in man.

Core temperature measurement in man. Transient changes in core temperature were induced in 12 subjects--passively by immersion in a hot bath, and actively by light intermittent exercise. Measurements of core temperature were made at four sites--the auditory canal, mouth, rectum, and oesophagus--and, by using the measurements from the first three of these sites, a mathematical model was derived which permits the calculation of a predicted value for oesophageal temperature (Toe). This model--which takes the general form Toe = ATx + BdTx/dt + C where Tx = amplitude of the temperature change at a specific site, dTx/dt = rate of change of temperature at that site, and A, B, and C = site constants (different for passive and active heating)--provides an accurate prediction of Toe (to within 0.1 degrees C) from both auditory canal and mouth temperature. For prediction of Toe from rectal temperature, however, two models appear to be necessary--one to predict Toe when core temperature is rising, and another to predict Toe during the return to equilibrium when core temperature is declining.


Capillary fragility during air exposure of man to 1-5 ATA and after decompression. Capillary fragility in man during exposure to 1-5 ATA air and after decompression from these pressures was studied by means of a petechiometer. A significant increase in capillary fragility was observed at 4 and 5 ATA air and after decompression from 3, 4, and 5 ATA air to normal pressure. It is suggested that this phenomenon may be associated with impairment of neurophysiological functions detectable only by special tests.


Blood volume and cardiorespiratory responses to lower body negative pressure. Breath-by-breath measurements of pulmonary capillary O2 transfer and ventilation were made on three subjects during and after 10 min of lower body negative pressure (LBNP) at -20, -40, and -60 torr. Loss in blood O2 stores (O2B) during and replenishment after LBNP were directly related to the intensity of LBNP. The peak rise in pulmonary capillary O2 transfer after release of LBNP was always preceded by a decrease in leg volume, indicating that O2B changes were related to blood volume shifts. The return of O2-depleted, pooled blood to the central circulation during the first minute of recovery caused significant hyperpnea. Three compartment lung model analyses from alveolar and arterial blood samples at -60 torr showed an increase in the alveolar deadspace fraction from 0.09 to 0.17, and a decline in the effective compartment from 0.83 to 0.77. The less effective lung perfusion during LBNP may explain a 30% increase in ventilation equivalent for O2.


Regional coronary blood flow at rest and during high sustained +Gz in a miniature swine with subclinical, ischemic, coronary heart disease due to coronary stenosis. New-generation high-performance aircraft can produce levels of high sustained +Gz which may exceed man's physiological capacity to withstand such stress. The severity of this stress has led to concern that sudden incapacitation due to coronary heart disease could occur during sustained +Gz. This report presents results obtained from an apparently asymptomatic miniature swine with a severe stenosis of the left anterior descending branch of the left coronary artery. Regional coronary blood flow was measured with the radiolabeled microsphere technique using 9 +/- 0.8 microgram diameter microspheres. Under resting conditions, myocardial blood flow was marginally depressed in the areas distal to the coronary stenosis. When the animal was exposed to +7 Gz, a large portion of the heart became acutely ischemic due to a redistribution of coronary blood flow. After 49 x of exposure to +7 Gz, the animal developed fatal ventricular fibrillation. Histologically, the areas of myocardium supplied by the stenosed vessel showed a variety of ischemia-induced lesions, including infarction and patchy myocardial fibrosis.


Intracardial gas bubbles and decompression sickness while flying at 9,000 m within 12-24 h of diving. Intracardial gas bubbles, detected with Doppler ultrasound, and symptoms of decompression sickness were registered at 9,000 m simulated altitude within 12, 18, and 24 h of exposures to 15 or 39 m simulated water depth allowing no stage decompression. With a time interval of 12 h between diving and flying, the earliest intracardial bubbles were found in some subjects already during the first minutes at altitude, and the earliest symptoms of decompression sickness some minutes afterwards. With an 18-h interval, the earliest bubbles and symptoms as well as their average time onsets appeared somewhat later. With a 24-h interval, the earliest bubbles and symptoms were detected slightly later, i.e. after 17 min and 23 min, respectively. Thus, a safe time interval between no-stage decompression dives and flying at 9,000 m cabin altitude for a maximum of 15 min appears to be 24 h. For prolonged such flights, a longer time interval seems to be necessary.


Psychophysiological forecasting of efficiency. The method of mathematical forecasting of the changes in efficiency throughout an increase in emotional stress is suggested on the basis of experimental data from experiments in which paratroopers discerned visual patterns. The comparison of human errors with the experimental results obtained in animals permitted formulation of several suppositions on the role of different cerebral structures in the genesis of emotional stress and the mechanisms of its effect on perceptive activity.


Effects on handgrip strength due to arm immersion in a 10 degree C water bath. Thirteen male and female human subjects participated in an experiment to determine if cold water immersion of the arm increases post-immersion handgrip strength. The test involved immersion of a subject's fore-arm into a 10 degrees C water bath for 30 min once a week in a 3-week series, involving a control test and two immersion experiments. Handgrip strength was measured 20 min before and then once every 20 minutes after the cold bath immersion for 4 h, for a total of 18 readings. Grip strength significantly decreased as a consequence of immersion of the forearm. However, strength recovery to approximately normal values took place within 40 min. No increases in post-immersion strength were observed.


Intensity judgements of non-sinusoidal vibrations; support for the ISO weighting method. Three experiments were conducted to compare the independent component method and the weighting method, recommended by current vibration standards for evaluating complex vibrations. Seated subjects matched their perceptions of the intensity of various Z-axis vibrations by adjusting the intensity of a sinusoidal matching frequency. Exp. I stimuli were composed of from one to four sinusoids in the frequency range from 11--63 Hz, Exp. II stimuli were made up of from one to four third-octave bands of random vibration with center frequencies from 16--40 Hz, and Exp. III stimuli were composed of from one to four sinusoids from 2.6--16 Hz. In all three experiments, the acceleration of the matching response increased significantly as the number of sinusoids or third-octave bands in the stimulus increased. Such a relationship is not predicted by the independent component method, but is predicted by the weighting method. Moreover, when the weighted accelerations of the matching responses are compared with the weighted accelerations of the input vibrations, the correspondence is quite good for all three experiments. These results support adoption of the weighting method as the preferred procedure for evaluating complex vibration environments.


Studies on the erythron and the ferrokinetic responses in beagles adapted to hypergravity. Red cell survival, ferrokinetics, and hematologic parameters were investigated in Beagle dogs exposed to chronic hypergravity (2.6 Gx). Ineffective erythropoiesis, red cell mass, plasma volume, and 51 Cr elution were significantly increased; maximum 59Fe incorporation was decreased; and there was no change in the mean erythrocyte life span following autologous injection of 51Cr-labeled red cells and 59Fe-labeled transferrin. Red cell count, Fcells, total body hemoglobin (Hb), susceptability to osmotic lysis, and differential reticulocyte count were increased. White blood cell count, venous blood %Hb, mean cell volume, mean cell Hb, mean cell Hb concentration, and serum iron were decreased. No changes were observed for body mass, mg Fe per g Hb, iron binding capacity, percent saturation of iron carrying capacity, or the electrophoretic mobility of purified Hb. This study indicated that chronic exposure to hypergravity induced changes in red cell size, volume, total mass, and membrane permeability.


Testicular growth and functional capability after 4-24 weeks of continuous exposure to 11 ATA He-O2. A study of testicular developmental and functional capabilities was made of rats continuously exposed for 4, 8, 12, 16, 20, or 24 weeks to 1 ATA He-O2, 11 ATA He-O2, or ambient pressure air environmental conditions. Other groups of rats were exposed for 24 sequential weeks to the same three sets of environmental conditions with brief interruptions for decompression and recompression at the end of each 4 weeks. The rats were comfortably housed and adequately fed in accord with earlier investigations. Visual observations of the testes at the time of slaughter, dry matter content of the testes, and histological examinations--all revealed normal growth and active spermatid formation from healthy germinal epithelia in all semeniferous tubules. The stress of hyperbaria or of helium to 11 ATA did not inhibit or destroy male germinal epithelial functional capabilities.


Disseminated melanoma presenting as a catastrophic event. The possibility of a patient with malignant melanoma having a catastrophic event as the presenting sign of tumor dissemination cannot be dismissed. Should such an event occur, it would pose not only a risk to the patient, but also a potential risk to others. Since 1971, 712 patients with malignant melanoma have been evaluated. Twenty patients presented with brain metastases and an additional 12 patients developed brain metastases simultaneously with other organ involvement. Four patients (0.6%) had a catastrophic event, such as a stroke or seizure, with no antecedent symptoms. Microstaging of a primary melanoma by the methods of Clark and Breslow, in addition to the recognition of the presence or absence of regional lymph node metastases, provides reliable information for predicting the probability of tumor dissemination. Patients with deep primary melanomas or with lymph node metastases should be advised regarding their participation in potentially hazardous occupations or recreations.


Laryngeal problems in space travel.

Laryngeal problems in space travel. A start has been made in enumerating possible problems of the larynx, in short or moderately long space voyages, based on our current knowledge of laryngeal diseases. The gravity-free state does not seem to be a threat to the physiology of the larynx. A relatively nonspecialized medical team must be able to recognize and manage Earth-type diseases. They must also be capable of managing both the special problems associated with various degrees of decompression sickness and the increased possibility of inhaling a foreign body, which are inherent in the gravity-free state. In crew selection, a special attempt should be made to eliminate those members with an increased risk of laryngeal disease development. Simplified methods of examining the larynx, including flexible fiberoptic laryngoscopy, should be available. Airway management, including coaxial endotracheal intubation with a bivalved laryngoscope, would be possible. An audiovisual tape library of simple and moderately complex procedures would be highly valuable.


Case report: intracardial gas bubbles in relation to altitude decompression chokes. A case of altitude decompression chokes in a subject is described, which occurred unintentionally in an experimental series dealing with safe time intervals between diving and flying at 9,000 m of altitude. Before the development of the first signs of chokes, intracardial gas bubbles could be registered during 65 min and heavy showers of bubbles during 38 min with the precordial Doppler ultrasound technique. The intracardial bubbles and symptoms partly continued after recompression to surface pressure. After 10 min of hyperbaric oxygen treatment, the symptoms disappeared completely. The same subject, as well as others, did not develop chokes with similar durations of heavy showers of intracardial gas bubbles in other experiments.


Measurement of skin temperatures of active subjects by wireless telemetry. A new sensor has been developed for measurement of skin temperatures of active human subjects that consists of a radio transmitter circuit incorporating a skin thermistor in a small epoxy slab or "tab." These tabs are reuseable, being large enough to permit battery replacement if required. They are glued to a subject's skin (thermistor side facing the skin) with a quick-setting adhesive and are easily removed after a 10-h period with an appropriate solvent. Thermal information is easily obtained from the sensor by a hand-held calibrated radio receiver accurate to +/- 0.1 degree C. This technique permits easy and rapid documentation of the thermal stress of active human subjects without interfering with their activity or clothing.


Corrections, deviance, and social system stability. Social control within a complex adaptive system is analyzed through the concept of requisite system variety in order to develop a conceptualization to assess the impact of various correctional modalities on social system viability. It is thus possible to critique contemporary strategies of criminal corrections in terms of their overall implication for social system change and to assess their potential contributions to long-run social system stability and adaptability.


The effect of clofibrate and pyridinol carbamate on the circulating immune complexes and cellular immune response in experimental atherosclerosis. Cholesterol-fed rabbits were treated with clofibrate, pyridinol carbamate and with both drugs simultaneously. The quantity of circulating immune complexes in the sera of the animals was measured weekly and the migration inhibition test was carried out in the 12th week of the experiment. The trend of the changes in the concentration of the immune complexes was rather similar to that of the cellular immune response. Compared with the values obtained in the control animals, in the cholesterol-fed group a markedly higher level of immune complexes and a significant migration inhibition could be detected. The administration of clofibrate or pyridinol carbamate alone had no effect on the concentration of immune complexes. Pyridinol carbamate did not influence the migration inhibition; however, it became similar to the healthy controls in the clofibrate-treated group. Simultaneous treatment with both drugs resulted in a decrease in the quantity of immune complexes and a diminution of the migration inhibition.


Uptake of labelled free and esterified cholesterol from plasma by the aortic intima--media tissue measured in vivo in three animal species. Hyperlipemic stilboestrol-treated cockerels, cholesterol-fed rabbits and minipigs, as well as normolipemic cockerels and rabbits were injected intravenously with homologous plasma of corresponding lipid concentration labelled in vivo with radioactive cholesterol. The ratios between labelled free cholesterol and labelled esterified cholesterol in the intima--media from the thoracic aorta of these 5 groups of animals were respectively 1-, 2-, 8-, 2- and 20-fold greater than the corresponding average tracer ratio in plasma during the uptake period of 4--6 h. The intima--media tissue in the coronary arteries studied in one minipig contained 2--5 times more labelled cholesterol per mg wet weight than corresponding aortic tissue. This arterial uptake of labelled cholesterol in the minipigs was measured concomitantly with the uptake of phosphatidylcholine and plasma protein labelled in vivo. The uptake for these various tracers in the minipig suggested entry of labelled free and esterified cholesterol into the arterial wall, mainly as part of the plasma lipoproteins, with subsequent hydrolysis in the arterial wall of some of the cholesterol ester. In the stilboestrol-treated cockerels hydrolysis of cholesterol ester seems to be absent. The relatively higher uptake in the minipig of the labelled plasma protein (albumin) than of the lipoprotein (as traced by its lipids) suggests a molecular weight-dependent arterial entry of these plasma macromolecules.


Modification of human platelet function by a diet enriched in saturated or polyunsaturated fat. Twelve healthy male subjects were maintained on a saturated fat (SF) dietary regimen followed by a polyunsaturated fat (PUF) regimen. At selected intervals a number of tests were carried out to assess the effect of SF or PUF on platelet composition and activation. Concomitant with the fall in serum cholesterol, associated with the PUF diet, there was a decrease in plasma heparin neutralizing activity (as measured by the heparin--thrombin clotting time), and a fall in the number of circulating platelet aggregates was also observed. These two parameters suggest diminished platelet activation. Malondialdehyde production (an index of prostaglandin synthesis) was unchanged throughout the two dietary periods. Changes in the quality of the dietary fat were manifested in the phospholipid fraction of platelet lipids, particularly phosphatidyl choline and sphingomyelin. Platelet counts of whole blood were significantly decreased when subjects were consuming PUF, but not all of these alterations were reflected in platelet-rich plasma. These results indicate that platelets may be activated in apparently normal people consuming a SF diet (the standard diet of developed countries) and that this activation may be decreased by replacement of dietary SF with PUF.


Cholesterol vehicle in experimental atherosclerosis. Part 16. Effect of peanut oil on pre-established lesions. Rabbits were fed an atherogenic diet (2% cholesterol and 6% corn oil) for 8 weeks and then divided into groups of equal average serum cholesterol levels. One group was autopsied, and the others were returned to cholesterol-free diets consisting of commercial laboratory ration or ration augmented with 6% corn oil, peanut oil or PGF, a fat designed to resemble peanut oil minus arachidic and behenic acids. The animals were maintained on the diets for 8 more weeks. On all regimens, severity of atherosclerosis was exacerbated. The extent of exacerbation was significantly less in rabbits fed corn oil than in the others. The extent of exacerbation of lesions appears to be a function of the level of unsaturation of the dietary fats.


Aortic cholesteryl esterase. Influence of bile salts. The in vitro activity of cholesteryl ester hydrolase preparations of rat and rabbit aortas was assayed in the presence of the taurine and glycine conjugates of cholic, chenodeoxycholic, deoxycholic and lithocholic acids or in the presence of Triton X-100 and Tween-20. Maximum activity was obtained with tauro- or glycocholic acids. As in the case of pancreatic cholesteryl esterase, trihydroxycholanoic acid derivatives may serve an obligatory function.


Immune mechanisms in patients with proven vascular disease. Lymphocyte transformation and serum levels of immunoglobulins and complement were measured in groups of patients with old myocardial infarction, with peripheral vascular disease and in age- and sex-matched controls. There were no significant differences between the groups in phytohaemagglutinin (PHA) induced lymphocyte transformation, in IgA or in serum complement levels. The levels of IgG and IgM were significantly raised in patients with old proven infarcts while the level of IgM was raised in patients with peripheral vascular disease.


[Measurement of ventricular fluid pressure and brain tissue pressure in acute experimental communicating hydrocephalus (author's transl)]. Malabsorption of cerebrospinal fluid was made experimentally by the administration of neutral carbon black suspension into the lateral ventricles of 22 adult cats. The compartmental analysis of intracranial pressure at the intraventricular fluid and tissue pressure in the cerebral white matter was carried out in the early stage of the communicating hydrocephalus. Following results were obtained: 1) Cerebrospinal fluid pressure from the lateral ventricle was always significantly higher than that from the brain tissue during the process of ventricular expansion. 2) Water content in the cerebral white matter was correspondingly increased when the pressure difference with greater value in ventricular fluid pressure was maintained. However tissue water content was decreased definitively when such pressure values at two compartments were equalized due to augment of the tissue pressure component. 3) Decreasing of cerebral blood flow demonstrated in spite of relatively higher value of cerebral perfusion pressure. From these findings the authors speculated that a higher pressure in the ventricular system will be a driving force, by which the enlargement of ventricular system was induced.


[Angiographically visualized extravasation in a case of arteriovenous malformation: the first case in Japan (author's transl)]. A case of arteriovenous malformation (AVM) with angiographically visualized extravasation of contrast medium on carotid angiography has been reported. The patient, a 9-year-old girl, came to our clinic with chief complaints of unconsciousness and left hemiplegia. On right carotid angiogram, done 4 hours after stroke, an AVM with a large intracerebral hematoma at the region of the right basal ganglia was recognized. The AVM was feeded from several lenticulostriate arteries and a small branch from precentral artery, and drained into thalamostriate vein. The extravasation of contrast medium was seen in a sash like fashion through arterial and venous phase. Extravasation of contrast medium from AVM has been extremely rarely reported, and this is considered as the third reported case. From the study of these 3 cases, we have discussed about the rarity of the extravasation from AVM and the causative factors.


Plasma noradrenaline concentrations during isometric exercise. Blood was collected simultaneously from the left ventricle and pulmonary artery in 12 patients undergoing routine cardiac catheterisation and was analysed for noradrenaline concentrations at rest, during, and after isometric stress (hand grip). Moderate isometric exercise resulted in a significant rise in plasma noradrenaline with a return to basal values 10 minutes after discontinuing the grip test. There were no significant differences in noradrenaline levels between the left ventricular and pulmonary arterial samples either at rest or during exercise. Three patients with evident left ventricular dysfunction had the highest plasma noradrenaline concentrations, in contrast to the much lower levels in 2 patients on beta-blockers and in 1 patient with a normal heart. As moderate isometric effort results in an important increase in noradrenaline level, this form of exercise could be dangerous in subjects suffering from ischaemic heart disease or in those with impaired left ventricular function since these patients are particularly susceptible to arrhythmias.


Excretion of myoglobin in urine after cardiac catheterisation. Myoglobin levels were assayed in each urine specimen voided during 12 hours before and 48 hours after routine cardiac catheterisation in 146 patients using an indirect haemagglutination method detecting concentrations in excess of 0.015 mg/ml. Myoglobinuria was found in only one patient before but in 39 patients after cardiac catheterisation (27%), either in the first (34 patients) or the second (5 patients) post-catheterisation urine sample. Once detected, myoglobin was present in all subsequent urine specimens for the next 3 to 22 hours (mean 11.8 hours). The mean amount excreted +/- SE was 14.0 +/- 1.6 mg (range 2.6 to 30 mg) excluding the one patient with myoglobinuria before catheterisation. This patient, who had severe aortic stenosis and atherosclerotic heart disease, excreted 130 mg myoglobin. Patients with myoglobinuria required longer screening time to complete the procedures undertaken than those in whom myoglobin was not detected--15.6 +/- 1.4 and 11.1 +/- 0.6 minutes, respectively (mean +/- SE:P less than 0.01). We conclude that myoglobinuria is not uncommon after cardiac catheterisation, and that though the myoglobin detected may be released from skeletal muscle, it could be partly or wholly of cardiac origin and indicate transient, and presumably reversible, myocardial injury.


Immunological determination of serum m-AST activity in patients with acute myocardial infarction. Serum m-AST (mitochondrial isoenzyme of AST) activity in patients with acute myocardial infarction was determined quantitatively by a new immunological technique which is sensitive and easily available. All 31 patients with acute myocardial infarction showed abnormally high levels of serum m-AST (more than 5 KU/ml); the mean serum m-AST activity attained its peak (42.0 +/- 4.9 KU/ml) on the first day after the onset of infarction 5 hours later than that of serum t-AST (total AST) activity in 15 patients whose peak m- and t-AST activities were identified clearly. The individual peak m-AST activity correlated with the total CK released (r = 0.83, n = 15), indicating that the release of m-AST also reflects the infarct size. The ratio of serum m-AST/t-AST increased following myocardial infarction and showed the maximal value (average 25.7%) on the third to seventh day after onset. This ratio in the patients with acute myocardial ifarction was also greater than that in patients with liver disease or with heart failure from causes other than acute myocardial infarction. In the patients who had the additional complication of heart failure and/or cardiogenic shock the ratio was also greater than that is the patients without these hazards. These results indicate that the ratio of serum m-AST/t-AST reflects the severity of the myocardial cellular damage in acute myocardial infarction.


Determination of right ventricular wall thickness in systole and diastole. Echocardiographic and necropsy correlation in 32 patients. To show that right ventricular wall thickness (RVWT) measurements can be made with precision by echocardiography, we correlated these measurements with those obtained at necropsy in 32 terminal patients. The correlation between the echocardiographic diastolic right ventricular wall thickness (mean 4.0 +/- 1.62 mm) and the necropsy measurement (mean 4.3 +/- 1.52 mm) was good (r = 0.83) in all 32 patients with normal or increased right ventricular wall thickness at necropsy. In 19 patients without necropsy evidence of right ventricular hypertrophy (RVWT less than or equal to 4 mm), the mean diastole and systolic right ventricular wall thickness were 3.0 +/- 0.92 mm and 5.1 +/- 1.64 mm, respectively. In 13 patients with necropsy evidence of right ventricular hypertrophy (RVWT greater than or equal to 5 mm), the mean diastolic and systolic right ventricular wall thicknesses were 5.3 +/- 1.56mm and 8.2 +/- 1.88 mm, respectively. We conclude that technically satisfactory echocardiograms of the right ventricular wall thicknesses. Echocardiography can reliably estimate the diastolic wall thickness and may be helpful in the evaluation of right ventricular hypertrophy.


Noninvasive assessment of left ventricular function in myotonic muscular dystrophy. In order to assess left ventricular function, measurements of left ventricular internal dimension and its rate of change have been made by echocardiography in 7 patients with myotonic dystrophy and the three children of one of them, who were clinically normal but had abnormal muscle biopsies. Electrocardiograms and systolic time intervals were also recorded in all. Only one patient had signs of overt heart disease and an abnormal electrocardiogram (type B WPW). Systolic time intervals were normal in all 7 patients. Five subjects had echocardiographic abnormalities, which were of minor degree except in the patient with overt heart disease who had considerable impairment of both systolic and diastolic left ventricular function. Another patient had abnormalities of both systolic and diastolic function; systolic abnormalities occurred alone in one patient and diastolic abnormalities alone in one relative. It is concluded that patients with myotonic dystrophy and no clinical signs of heart disease may have minor abnormalities of left ventricular function as shown by echocardiography. Echocardiography is more sensitive than systolic time intervals in detecting these abnormalities; both systolic and diastolic function abnormalities, alone or together, can occur. There seems to be no relation between involvement of skeletal and cardiac muscle.


Ebstein's anomaly in persistent common atrioventricualr canal. This report documents 2 patients who presented with cyanosis early in life. In both instances the necropsy showed the simultaneous occurrence of an imcomplete type of persistent atrioventricular canal and an Ebstein's malformation of the "tricuspid" valve component. In the first patient no clinical investigations were done. In the second patient the electrocardiogram was consistent with persistent atrioventricular canal and the angiocardiogram showed the characteristic goose-neck deformity. Moreover, an abnormality of the right cardiac contour was seen, which in retrospect was correlated with the right-sided Ebstein's malformation. Ebstein's anomaly may significantly alter the clinical and haemodynamic profile of atrioventricular canal and should be considered in atypical cases. The presence of Ebstein's anomaly will complicate surgical repair of the atrioventricular canal.


Noninvasive cardiovascular findings in familial amyloid polyneuropathy. The cardiovascular system was examined in 19 cases of familial amyloid polyneuropathy. In a group of patients with neurological involvement, various cardiac abnormalities were common, including orthostatic hypotension, prominent apex cardiographic A waves, abnormal apical systolic waves (bulges), systolic murmurs, mid-systolic clicks, QS waves, atrioventricular block, left bundlebranch block, and abnormalities of ejection time and pre-ejection period. Though there was one case with pronounced cardiac abnormality despite a normal neurological state, and though cardiovascular symptoms appeared later than neurological symptoms, the degree of cardiac involvement generally paralleled the severity of the neurological disorder.


Severe pulmonary hypertension in advanced aortic valve disease. Review of haemodynamic data of 151 cases with isolated aortic valve disease revealed severe pulmonary hypertension (pulmonary arterial systolic pressure of 60 mmHg or more) in 17 (11%). The left ventricular end-diastolic pressure was high in all but one case, suggesting that the severe pulmonary hypertension was a reflection of the late stages of aortic valve disease. The majority (64.7%) had a low cardiac index. Premature closure of the mitral valve was seen in 12 of the 17 patients. While the incidence of premature mitral closure was the same as in others with mild and moderate pulmonary hypertension, the average reversed ventriculoatrial gradient was higher in the latter groups.


Familial sinus node dysfunction with autosomal dominant inheritance. A large family with sinus node dysfunction is described, spanning three generations and with an autosomal dominant trait. There was an obvious association between the grade of mental retardation and the severity of the sinoatrial disorder.


Wolff-Parkinson-White syndrome (type A) complicated by heart block in both normal and accessory pathways. A 67-year-old man with Wolff-Parkinson-White syndrome type A presented with second degree atrioventricular block in anomalous pathway and complete infra-Hisian block in the His-Purkinje pathway. He had increasingly frequent attacks of dizziness not related to exercise. A permanent ventricular demand pacemaker was successfully implanted following intracardiac electrophysiological studies.


Pressure reversal of general anaesthesia--a multi-site expansion hypothesis. We have quantitated the pressure reversal of continuous i. v. anaesthesia produced in rats by ketamine, methohexitone, propanidid and thiopentone. These and other data are not consistent with the earlier critical volume hypothesis of general anaesthesia and therefore we postulate an alternative molecular mechanism--the multi-site expansion hypothesis.


Effect of certain anaesthetic agents on the activity of rat hepatic delta-aminolaevulinate synthase. The activity of delta-aminolaevulinic acid synthase (E.C.2.3.1.37) (the rate-limiting enzyme for haem and porphyrin biosynthesis) has been measured in the rat liver after the repeated administration of anaesthetic agents in vivo. The activity of the enzyme was increased by Althesin, chlordiazepoxide, enflurane, etomidate, lignocaine, methohexitone, methoxyflurane, pentazocine and thiopentone and decreased by procaine. No significant changes in activity occurred after the administration of amethocaine, atropine, bupivacaine, diazepam, droperidol, halothane, ketamine, morphine, nitrous oxide, pethidine, phenoperidine, prilocaine and propanidid. It is suggested that those anaesthetic agents which induced activity of the enzyme should not be administered to patients with an acute porphyria.


Muscle blood flow and rate of recovery from pancuronium neuromuscular blockade in dogs. The effect of changes in muscle blood flow on the rate of recovery from neuromuscular block produced by pancuronium was investigated in dogs, and were shown to be independent variables. The significance of this finding in relation to recent work on blood concentrations of the drug and on the pharmacodynamics of the drug is discussed.


Comparison of sampling techniques for studies of nitrous oxide pollution. The retention of nitrous oxide in samples of nitrous oxide in air held in disposable plastic syringes, glass syringes and custom-made nylon film bags was studied by means of gas chromatography at intervals of 90 min, 24, 48 and 120 h after filling the containers. After 24 h the nylon bags retained a mean concentration of 94.5% of the original concentration of nitrous oxide. The disposable plastic syringes and glass syringes were unsatisfactory and retained only 80% of the original concentration of nitrous oxide after 90 min. These values decreased to 51% and 31% of the original concentration of nitrous oxide respectively at 24 and 48 h.


A pharmacodynamic model for pancuronium. It has been demonstrated that a simple two-compartment kinetic model may account for the changes in plasma concentration of pancuronium after i.v. administration. However, it can be shown that this simple model does not account satisfactory for the observed changes in muscle twitch response. By the addition of a receptor (biophase) compartment, twitch response can be reconciled with model behavior and the characteristics resemble those predicted by animal studies. The complete model is applied to the problem of total renal failure, and shows that patients with this condition are likely to be marginally resistant to small doses of pancuronium, with a normal rate of recovery. However, larger doses are likely to result in delayed recovery, the duration of effect increasing in a dose-dependent manner.


Variation in the disposition of morphine after i.m. administration in surgical patients. The disposition of morphine when administered by i.m. injection was studied in 36 patients receiving morphine as part of premedication before general anaesthesia, and in five patients who received morphine as a postoperative analgesic after median sternotomy for coronary artery surgery (PCA group). Maximum plasma concentration of morphine (CP max) was 75.3 +/- 6.0 (mean elimination rate constant (k) 4.85 X 10(-3) min-1 and half-life (T1/2) = 143 min for the preanaesthetic group. The corresponding values for PCA group were CPmax = 58.0 +/- 18.0 ng ml-1 (range 30--130 ng ml-1), k = 5.63 X 10(-3) min-1 and T 1/2 = 123 min. Analysis of variance showed no differences between the groups. Within the preanaesthetic group, there was a significant difference in k between males (k = 4.01 X 10(-3) min-1) and females (6.30 X 10(-3) min-1, P less than 0.01). The corresponding T 1/2 for males was 173 min; and 110 min for females. The variation in the disposition of morphine is thought to be the result of variations in resting muscle blood flow and inadvertent injection into adipose tissue. There were no significant differences between males and females in the preanaesthetic group with respect to age, Cpmax or time from injection to Cpmax.


Pancuronium pharmacokinetics in patients with liver cirrhosis. The serum and urinary concentrations of pancuronium were measured in 14 surgical patients with cirrhosis and 12 patients free from liver disease undergoing abdominal surgery. A two-compartment open model was used in the pharmacokinetic analysis of the data. A two-fold increase in both the distribution half-life (T 1/2 alpha) from 11 min to 24 min and in the elimination half-life (T 1/2 beta) from 114 min to 208 min was observed in patients with cirrhosis. In these individuals, the total apparent volume of distribution of pancuronium was increased by 50%. Plasma clearance of pancuronium was decreased by 22%. No significant difference was found in the urinary excretion and biotransformation pattern of pancuronium. These results suggest that there is a risk of prolonged duration of action of pancuronium in patients with cirrhosis. In these patients, the initial dose to achieve adequate muscle relaxation is high and simultaneously there is slow disappearance of pancuronium from plasma. These alterations are mainly a consequence of the increase in the distribution volume of pancuronium in patients with cirrhosis.


Gastro-oesophageal pressure gradient changes produced by induction of anaesthesia and suxamethonium. The pressures in the lower oesophageal sphincter (high pressure zone or HPZ) and stomach were measured in 15 patients with duodenal ulcer and 14 patients with no gastrointestinal disease. All the patients were premedicated with morphine 10 mg i.m. In the patients without duodenal ulcer, the pressure gradient between HPZ and stomach was 6.6 +/- 0.62 mm Hg (mean +/- SEM) before diminishing to 4.9 +/- 0.86 after induction of anaesthesia with thiopentone. During fasciculations following i.v. suxamethonium, the gradient increased to 7.1 +/- 1.0 mm Hg. In patients with duodenal ulcer, although the absolute pressures were less, the gradients during the study were similar to those in healthy patients. We conclude that there is no increased risk of regurgitation during fasciculations induced by suxamethonium.


Relationship between stomach contents and analgesia in labour. The volume of stomach contents found in patients undergoing Caesarean section was studied. The largest volumes were found in patients who had received pethidine analgesia and the smallest volumes in patients who had received either extradural analgesia or no analgesia. Intermediate volumes were found in patients who had received pethidine in addition to extradural analgesia. Pethidine, rather than the emotional stress of labour, was thought to cause gastric retention. Patients having elective Caesarean sections had considerably less gastric retention than patients in labour.


An automatic interference refractometer. Interference refractometry is a well-established method of determining the concentration of anaesthetic agents in gas mixtures. A photo-electric detector system has been fitted to a small portable, direct-reading interference refractometer to display automatically the concentration of the agent being measured. The design of the instrument is described and two possible methods of information display are suggested.


Staffing in anaesthesia in Australasia.

Staffing in anaesthesia in Australasia. A survey of Australasian departments of anaesthesia was undertaken. Recommendations for ideal staffing are made and the extent to which present staffing satisfies these recommendations is described.


Light and electron microscope studies of the rat digestive tract following prolonged and short-term ingestion of chrysotile asbestos. Rats were fed diets containing 0.5 mg or 50 mg of chrysotile asbestos each day for 1 week or 14 months and tissues of the gastrointestinal tract were examined by light and electron microscopy. At the light microscope level the oesophagus, stomach and caecum in treated animals appeared unaffected, whereas accumulation of cellular debris and Alcian blue-positive material was apparent in the ileal, rectal and colonic lumens. Electron microscope examination of the colon and ileum of rats ingesting 50 mg chrysotile/day for 14 months confirmed these findings and indicated changes in the mucosal lining cells of the ileum which were consistent with a mineral-induced cytotoxicity. These results are compared with those reported in a similar previous biochemical study and the specificity of asbestos action on certain regions of the gastrointestinal tract is discussed.


Modification of the tuberculin reaction by levan. High molecular levan (polyfructoside) inhibits the skin tuberculin reaction in guinea pigs as judged by the degree of induration and erythema. The effect is dose-dependent. No effect on cellular infiltration was observed in histological studies. The lymph nodes of levan-treated animals were smaller and exhibited a much milder granulomatous reaction than those of non-treated animals.


Changes in the nuclei of astrocytes following portacaval shunting and portacaval transposition in the rat. Structural abnormalities are found in the astrocytes of the dentate nuclei of animals after portacaval shunting (PCS). These changes are also found in man in association with portal-systemic encephalopathy. To investigate the relationship between portal-systemic shunting and hepatocellular dysfunction in the pathogenesis of these changes, PCS and protacaval transposition (PCT) were performed in rats. PCT diverts portal blood into the systemic circulation, but retains normal total hepatic blood flow by perfusion with systemic venous blood. Liver function and mass are better preserved than after PCS. Abnormal glial cells were found in 4.03% of animals following sham operation, 13.45% following PCT, and 19.09% following PCS. Both experimental groups differed significantly from control animals, and the number of abnormal cells was significantly higher after PCS than after PCT. These findings are in keeping with the hypothesis that hepatocellular dysfunction plays an important role in addition to portal-systemic shunting in the aetiology of the structural changes in the brain associated with hepatic encephalopathy.


Scanning electron microscopy of early postmortem artefacts in the small intestine of a neonatal calf. The stereoscopic appearance of early postmortem artefacts in the small intestine of a normal calf was examined with the scanning electron microscope. Swelling of villus tips and denudation of a few villi was observed 10 min after severing the carotid arteries. Similar changes were not seen in samples removed under anaesthesia.


The effect of D-galactosamine on plasma protein synthesis by the perfused rat liver from turpentine-stimulated donors. D-galactosamine (100 mg) was added to the reconstituted blood during 4h perfusion of livers isolated either from control rats or those injected with turpentine 20 h or 5 h earlier. This dose of galactosamine administered 30 min before [3H]lysine significantly inhibited the incorporation of the label into liver proteins, and even more into plasma proteins, but albumin and acute-phase reactants (fibrinogen, seromucoid fraction, Concanavalin A-adsorbed glycoproteins) were all similarly affected. When galactosamine was administered in vivo simultaneously with turpentine, and the liver was isolated 5 h later, trauma-induced fibrinogen synthesis was selectively inhibited. This can be explained either by a differential control of synthesis of various acute-phase reactants, or by augmentation of catabolism of fibrinogen in galactosamine-treated rats. Crossed immunoelectrophoresis of the full perfusate or Concanavalin A-adsorbed glycoproteins did not reveal any significant effect of galactosamine on the protein pattern obtained from control or turpentine-stimulated liver donors.


A stereological analysis of the effect of 19-nortestosterone (Durabolin) on rat skeletal muscle. It is known that some anabolic steroids are capable of increasing the sizes of skeletal muscles or increasing their mechanical performance. The present study was undertaken to establish quantitatively the alterations which occur in skeletal muscle fibres as a result of the injection of 19-nortestosterone (nandrolone phenyl proprionate). Specimens of diaphragm were obtained from the experimental and control animals and prepared for electron microscopy and stereological analyses. Following low doses of the steroid stereological analyses have shown that in Type I and in intermediate fibres their mitochondrial volume proportions increase though their myofilament contents decrease. With higher doses, stereological analyses have shown that the mitochondrial volume proportions were increased particularly in intermediate fibres whilst the myofilament content of Type I and II fibres was significantly reduced.


The treatment of uterine bleeding with vasopressin hormonogen (glypressin)--a pilot study. In a pilot study 12 women with severe uterine bleeding received an intravenous injection of 0.2 mg of a vasopressin hormonogen, glypressin. In 11 of the patients a rapid reduction or cessation of blood loss were observed. Two patients had facial pallor following the injection but no other side effects occurred. Five of the older women with long histories of menorrhagia were placed on a regime of one injection of glypressin on the first day of menstruation for six months; in all of them the duration of bleeding was reduced to three days and the monthly blood loss became very slight. On the basis of these results more extensive clinical trials in menorrhagia and metrorrhagia are recommended.


Haemoglobin Aic (glycohaemoglobin) in diabetic pregnancy: an indicator of glucose control and fetal size. Haemoglobin AIc (Hb AIc), a glycohaemoglobin present in normal human blood, is elevated in glucose intolerant individuals. In non-pregnant diabetic subjects, a direct relationship has been established between per cent Hb AIc and blood and urinary glucose levels over weeks and months. In this study, Hb AIc level and mean random blood glucose concentration in the third trimester of pregnancy were found to correlate directly in 12 diabetic women without vascular disease (P less than 0.001). In this same group of women, third trimester Hb AIc levels also correlated significantly with infant birth weight (P less than 0.05) and birth weight adjusted for gestational are (P less than 0.01). Finally, third trimester mean blood glucose concentrations also correlated directly with birth weight (P less than 0.05) and adjusted birth weight (P less than 0.001). In pregnancies complicated by diabetes, rigid glucose control has been recommended to achieve optimal fetal and maternal outcomes. Hb AIc is a new tool with which to assess blood glucose control during diabetic pregnancy.


Plasma pregnancy-specific beta1-glycoprotein in complications of early pregnancy. The prognostic value of a single plasma pregnancy-specific beta1-glycoprotein estimation was assessed in 64 patients admitted with a history of vaginal bleeding between 7 and 19 weeks gestation. A correct prognosis was obtained in a high percentage of cases with either continuing pregnancies or with non-viable pregnancies. In very early pregnancy with a gestation less than 10 weeks, a correct prognosis was obtained in about 75 per cent of cases but serial estimations in this group might improve the prognostic value of the test. The assay proved to be infallible where there was doubt as to whether the subject was pregnant. In the present study, single HPL estimations proved to be less useful in evaluating the outcome of complications of early pregnancy.


Relation between total uterine impulse, method of delivery and one-minute Apgar score. The resistance to the passage of the fetus during labour has been estimated indirectly by calculation of the total area below the intrauterine pressure curve (total uterine impulse) in two periods during  the first stage of labour. A good correlation was found between the total uterine impulse from a cervical dilatation of 5 to 10 cm, the outcome of the second stage of labour and the Apgar score at one minute.


Sex hormone levels and gonadotrophin release in premature ovarian failure. Premature ovarian failure was studied in ten women under the age of 30; eight had an ovarian biopsy and five of these showed primordial follicles. Plasma levels of oestradiol and progesterone were similar to the follicular phase of a normal menstrual cycle, but in eight patients cervical smears showed a cornification index of less than one per cent. Levels of both androgens and of sex hormone binding globulin capacity were generally normal. Administration of LH-RH caused a release of FSH which was similar to post menopausal women and higher than both. Two patients were treated with exogenous gonadotrophins without effect.


Preliminary results of a physiologically based treatment of amblyopia. An apparatus has been developed in which high-contrast square-wave gratings are rotated in front of the amblyopic eye while the child is performing some task requiring visual concentration. In the course of three 7-minute treatments 73% of patients treated achieved 6/12 or better; 75% of these patients had previously undertaken conventional or minimal occlusion.


Stereopsis and spatial perception in amblyopes and uncorrected ametropes. Amblyopes and nonamblyopes were compared on 2 tests of spatial perception. One, the Titmus stereotest, provided only disparity cues and thus measured pure stereopsis. The other, the 3-rods test, provided a variety of monocular and binocular cues and measured the precision of distance discrimination. On both tests the amblyopes were significantly worse than nonamblyopes with equivalent acuity deficits. The Titmus stereotest was found to be an effective means of screening for amblyopia. The results of the distance discrimination test are discussed in terms of their clinical and physiological implications.


Pseudostrabismus: an audit.

Pseudostrabismus: an audit. 331 children presenting with pseudostrabismus were assessed retrospectively; 24% of 77 ametropes developed a true convergent squint. Only 1.65% of 243 emmetropes developed a true squint, an incidence much less than in an unselected group. A close follow-up of emmetropic children presenting with pseudostrabismus would seem to be unjustified.


The O'Connor cinch revisited.

The O'Connor cinch revisited. The modified O'Connor cinch operation is a useful, but little used, adjustable resection operation. For increased understanding of its shortening and adjustment characteristics, a standard cinch was performed in animals and patients with strabismus. Animal studies showed that, as each strand of the cinch was removed, a small, relatively equal release of the cinch effect occurred. Measurement of the shortening obtained in patients with strabismus showed a consistent resection effect of about 4 mm. Review of 17 cases in which the cinch was used as part of the surgical treatment showed the technique to be adjustable by reducing the overcorrection in 6 cases. Ten to 20 prism dioptres of reduction in the deviation was obtained with adjustment of the cinch on the first postoperative day. All 17 cases had satisfactory adjustment. The largest residual deviation was 12 prism dioptres.


Follow-up of aphakic patients with anterior vitrectomy in one eye and uneventful cataract extraction in the fellow eye. Twenty patients had operations for bilateral cataract in 2 separate sessions, with uncomplicated extraction on one side and vitreous loss managed with anterior vitrectomy on the other. The cataracts, the type of surgery, and the postoperative treatment were identical in both eyes. The differences between the 2 eyes were not statistically significant so far as the amount of astigmatism, final visual acuity, and peripheral anterior synechiae were concerned. The main difference was found to be the period of time the vitrectomised eyes remained red and uncomfortable as compared to the eyes with uncomplicated surgery.


Surgery of congenital and juvenile cataracts: a pars plicata approach with the vitrophage. Eighteen eyes with congenital cataracts were surgically managed by pars plicata lensectomy and vitrectomy using the vitrophage. No major intraoperative or postoperative complications were encountered. All eyes have maintained extremely clear media, attached retinas, and absence of pupillary block during a follow-up period ranging from 12 to 36 months.


Aspiration from the vitreous of a non-magnetic foreign body. A non-magnetic vitreal foreign body was aspirated from over the macula through the pars plana. The surgeon guided a blunt needle towards the foreign body while watching both with the binicular indirect ophthalmoscope. His assistant's tentative suction movements with an attached syringe drew the foreign body up into the needle without risking a retinal perforation. Visual recovery was complete. It is suggested that aspiration might be the procedure of choice for such small visible intraocular fragments.


A disposable cannula for the aspiration of soft lens matter. A double cannula is described suitable for the aspiration of soft lens matter. The cannula is a modification of a double irrigation needle already marketed and will be available in a presterilised disposable pack for use with disposable syringes.


Morphological changes in the human conjunctival epithelium. II. In keratoconjunctivitis sicca. A clinicopathological correlation was performed on 24 patients suffering from keratoconjunctivitis sicca (KCS). Examination of conjunctival biopsies by light and transmission electron microscopy revealed stratification of the conjunctival epithelium with separation of the superficial cell layers, and this was directly proportional to the clinical severity of the disease. Counts of goblet cells were found to be inversely proportional to the degree of stratification. The goblet cells were morphologically identical to, but significantly fewer in number than, those found in normal conjunctival tissue. A reduction in epithelial cell stratification and separation and an increase in goblet cell density were closely related to nasolacrimal duct occlusion--an operation performed only in the severe examples of KCS in this series. The possible causes of 'mucous' plaques and 'filaments' are discussed in relation to these phenomena. Moreover, there is a dramatic reduction and deformation in the microplicae on the surface of the conjunctival epithelium. The significance of this was considered in relation to tear film stability.


Effect of undernutrition on the metabolism of phospholipids and gangliosides in developing rat brain. 1. Phospholipid content of brains of 3- or 8-week-old undernourished rats was 7--9% less than that for the corresponding control animals and this deficit could not be made up by rehabilitation. Phosphatidyl ethanolamine and plasmalogen were the components most affected in brains of undernourished rats. 2. Incorporation of 32P into phospholipids by brain homogenates was 28% higher in 3-week-old undernourished rats. It is suggested that enhanced phospholipid metabolism in undernourished animals may be related to behavioural alterations noted previously (Sobotka, Cook & Brodie, 1974). 3. Ganglioside concentrations in 3- and 8-week-old undernourished animals were 14% and 11.5% less respectively than those of the control animals and this difference could be made up by rehabilitation. [14C]Glucosamine incorporation in vivo into brain gangliosides was not affected by undernutrition.


The effects of plane of nutrition and environmental temperature on the energy metabolism of the growing pig. 1. Heat loss and critical temperature. 1. The heat losses and energy balances of thirty-eight individually housed pigs (initial body-weights 21--38 kg) were measured continuously for periods of 14 d when they were maintained at environmental temperatures of 10, 15, 20, 25 or 30 degrees. At each temperature four levels of feeding were given approximating to once, twice and three times the maintenance energy intake and the ad lib. level. The minimal maintenance energy requirement (M) was calculated to be 440 kJ metabolizable energy (ME)/kg0.75 per d at 25 degrees. 2. ME intake at the ad lib. level decreased from 1965 kJ/kg0.75 per d at 10 degrees to 1202 at 30 degrees. 3. Heat loss calculated from multiple regression analysis decreased to minimum levels between 20 and 25 degrees; 30 degrees was within the hyperthermic zone at each plane of nutrition. 4. The partition of heat loss into its sensible and evaporative components showed that evaporation increased from 25% at 10 degrees to 78% at 30 degrees. 5. Critical temperature was dependent upon food intake and decreased from 23.1 degrees at M to 20.7 degrees at 2M, 18.0 degrees at 3M and 16.7 degrees at 4M. 6. The extra food required to meet extra thermoregulatory heat production per 1 degrees below the effective critical temperature was 0.65 g/kg body-weight per d.


The effects of plane of nutrition and environmental temperature on the energy metabolism of the growing pig. 3. The efficiency of energy utilization for maintenance and growth. 1. From the relation between metabolizable energy (ME) intake and heat loss (H), energy retention (ER), protein (P) and fat (F) deposition the energy costs of maintenance (MEm) and the partial efficiencies of energy retention (k) and protein (kP) and fat (kF) retention were determined in growing pigs at environmental temperatures of 10, 15, 20, 25 or 30 degrees. 2. k decreased with increase in environmental temperature from 0.79 at 10 degrees to 0.63 at 30 degrees with 0.67 at the thermally-neutral temperature of 25 degrees. Each 0.04 decrease in k was associated with a 100 kJ/kg0.75 per d decrease in MEm. Analysis, within several ranges of environmental temperature, suggested a curvilinear relation between ER and ME intake indicating a decrease in k with increase in level of feeding, particularly at thermally-neutral temperatures. 3. Both kP and kF were similar at each environmental temperature and decreased from 0.78 at 10 degrees to 0.63 at 30 degrees. These values are discussed in relation to those predicted from experimentation and it is suggested that the wide range of predicted estimates of kF could be attributed to differences in the rate of protein turnover.


Serum albumin level in an urban Nigerian population. 1. Serum albumin levels have been estimated in healthy adult Nigerians. The average level of albumin was 41.4 g/l and there was no sex difference, but the findings differed from that of a previous survey in Ibadan. The importance of serum albumin measurement in relation to the socio-economic and dietary habits of the population has been reviewed. 2. It is concluded that socio-economic, dietary and cultural changes associated with Western education could be responsible for the increased level of serum albumin in this healthy population. 3. It is suggested that similar surveys should be done by locally-practising chemical pathologists.


Plasma alkaline ribonuclease (EC 3.1.4.22) and nitrogen retention in low-birth-weight infants. 1. Nitrogen retention was determined by classical N balance techniques in fourteen rapidly growing low-birth-weight infants receiving 3 g protein/kg body-weight and during their 3rd week of life. This was compared with plasma free alkaline ribonuclease (EC 3.I.4.22; RNase) activity and other biochemical measurements of protein nutrition. 2. Plasma RNase showed a significant positive correlation with N retention and a corresponding negative correlation with urine urea-N. These results were unexpected and suggest a different relationship between RNase and N retention in infants compared with that found by other workers in children and adults. 3. The most likely explanation of this apparent anomaly is that in all instances high activities of plasma RNase are associated with a need to conserve N. In the infants studied this may indicate some measure of 'protein economy' and they could therefore benefit from a higher protein intake.


The effect of the extent of hydrolysis in casein on its specific dynamic action in the rat. 1. Adult female rats given a diet containing 200 g casein/kg showed an increase in heat production which reached a maximum in 10--20 min after completion of food intake. 2. Replacement of casein in the diet by enzymic hydrolysates of casein of different extents of hydrolysis (pepsin for 1 or 3 h and pancreatin for 6, 12 or 24 h) resulted in a decrease in metabolic rate (stimulation) in the rat, reaching a maximum of 61.8% of the control value (non-hydrolysed casein). 3. The specific dynamic action of casein and casein hydrolysate was inversely proportional to the amount of amino-nitrogen released. 4. On the basis of the experimental findings it may be concluded that the synthesis and secretion of digestive enzymes were the main causes of the increase in metabolic rate after protein ingestion.