Airway cooling. Stimulus for exercise-induced asthma. Five patients were studied using a randomly assigned sequence of four inspired-air conditions during strenuous treadmill exercise for 10 min. The four inspired-air conditions were: (1) Cool, dry room air (CDA) at 23 degrees C with 3 mg of water and 7.3 cal of heat content/l, (2) over-saturated air (OSA) at room temperature containing 43 mg water and 16.3 cal/l, (3) hot, dry air (HDA) at 120 degrees C having 3 mg water and 24.4 cal/l, and (4) warm, humidified air (WHA) at 37 degrees C with 43 mg water and 34.7 cal/l. Using inspired-air CDA and OSA, all patients manifested exercise-induced asthma (EIA) while forced expiratory volume in 1 sec (FEV1) and maximal mid-expiratory flow (MMEF) decreased to an average of 81% and 63% of the baseline when breathing CDA and to 83% and 71% of the baseline when breathing OSA. With WHA, EIA was clearly prevented while the post-exercise FEV1 and MMEF were 101% and 103% of baseline, respectively. With HDA, the post-exercise FEV1 and MMEF were 95% and 86% of baseline, respectively. Analysis of variance revealed that the post-exercise pulmonary function changes had resulted solely from respiratory heat loss and not from water loss or from interaction of heat and water losses. These results indicate that exercise-induced asthma is associated with airway cooling incurred during exercise rather than airway dehydration.


Resistive breathing training in severe chronic obstructive pulmonary disease. A pilot study. We studied the effects of resistive breathing in 10 patients with long-standing, severe disabling COPD. Small increases in inspiratory resistive load resulted in diaphragmatic fatigue and failure in all patients. Fatigue was detected using the frequency spectrum analysis of an EMG signal obtained with surface electrodes. Failure was defined as an inward displacement of the abdomen during inspiration, i.e. incoordination of thoracoabdominal motion. The patients trained for one half hour daily for 4 weeks, breathing into a simple device, where they inspired against a resistive load that produced some incoordinated breaths. After 4 weeks this load was increased, if possible, and another 4-week training period started. All patients improved with training, i.e. higher resistances could be tolerated without signs of fatigue and failure. In addition most patients claimed that training had helped them in their daily living; they were able to do more without getting short of breath. The device helped expectoration, possibly owing to the effect of the small expiratory resistance.


[Drug-induced esophageal ulcers].

[Drug-induced esophageal ulcers]. In cases without a history of gastrointestinal or cardiac disease, acute odynophagia prompts the tentative diagnosis of drug-induced esophageal ulcer. Possible causes are tetracycline, clindamycin, emepronium bromide, potassium chloride, etc. Other diseases such as carcinoma can be ruled out by endoscopy and biopsy. To avoid such esophageal lesions drugs should be taken with sufficient fluid and not immediately before bedrest.


[The basophil degranulation test in the diagnosis of bee and wasp sting allergies]. Comparison of basophil degranulation test (BDT) with radioallergosorbent test (RAST) in 50 patients with anamnestically certain or probable hymenoptera allergy yielded practically equal results. In patients who had experienced their allergic reaction a long time ago, BDT seemed to react positively over a longer period of time than RAST. As BDT is technically easy to perform and moderate in price, it is suited to substitute RAST.


[Prescription profile in French speaking Switzerland and in the Tessin. Analysis of 2006 medical prescriptions]. Analysis of 2006 prescriptions given to 641 unselected patients by 360 doctors in the French- and Italian-speaking parts of Switzerland provides a wealth of information on prescription trends and the cost of medicine. The patients ordinarily received medication belonging to several therapeutic groups, usually 2 or 3 but up to 9 different groups. Each prescription averaged 2.08 drugs with a mean cost of 18.90 Swiss francs. The price varied considerably according to the group of drugs. Those related to the cardiovascular system were the most expensive closely followed by antibiotics, while the ophthalmological prescriptions were the least expensive. Hydergine is the most-sold drug in Switzerland, followed by Bactrim; however, if the various benzodiazepines were grouped together their sale would exceed the others. There are 62 different drugs for rheumatic conditions and 47 penicillins in Switzerland. The abundance of drugs and the prescription of medication with dubious action contribute to the inflationary cost of illness. For any given drug there is a striking parallelism between the number of pages publicizing it in 4 medical journals and total sales. This clearly demonstrates the influence of advertising on prescription trends. Doctors should be aware of this fact and rely on more objective sources of their information about drugs.


[Pollionosis: I. Findings on the clinical aspects and the pollen spectrum in 1565 pollen-sensitive patients]. Case histories are analyzed of 1565 hay fever patients first attending an allergy unit. The mean age of the test persons was 19.5 years. 40% were in the age group 5 to 15 years. The sex distribution showed a slight but statistically significant prevalence of males (56.6%). 56.8% had a positive family history of allergies and 44.2% had other allergic conditions such as atopic dermatitis (31.6%), perennial rhinitis and perennial asthma (19% each), urticaria, food allergy and drug allergy (5% each) and insect sting allergy (3%). A clear cut peak both for rhinitis and for asthmatic symptoms %30.5% and 20.2% respectively) was found in the age group 5--9 years. Up to the 14th year the symptoms of pollen allergy were already exhibited by 68.5% of the patients. 97% of the pollen allergics suffered from rhinitis, 95% from conjunctivitis, 40% from bronchial asthma and another 20% from tracheobronchitis or asthmatic bronchitis. As additional symptoms of pollen allergy due to haematogenous spread of the pollen antigens we observed a seasonal form of atopic dermatitis in 3%, a seasonal urticaria or angioedema in 3.5%, migraine in 6.3% and arthralgia, gastro-intestinal troubles and fever in fewer than 1% each. Almost 98% of the patients were sensitized to grass or cereal pollens. However, only 18% suffered from an isolated grass pollinosis (summer hay fever). The other patients were additionally clinically sensitized by other pollens with different blossoming periods, i.e. 35% by three pollens responsible for the so-called spring pollinosis, and 50% by weeds (plantain, nettle, mugwort) the cause of late summer pollinosis. Only 13 patients suffered from an isolated spring pollinosis (hazel, alder, birch, willow). In 14 patients (not quite 1%) with a clear-cut history and clinical symptoms of pollinosis, all the skin tests were negative. In these cases the sensitization was probably restricted to the respiratory tract. Despite the new in-vitro methods such as the RAST, carefully performed skin tests linked to a knowledge of the pollen calendars of the region and the allergological history remain the most reliable and cheapest procedure for the specific diagnosis of pollen allergy.


[The idiopathic osteolysis syndrome].

[The idiopathic osteolysis syndrome]. Idiopathic osteolysis of the multicentric type is a rather rare clinical entity without known causative factor at onset. It displays rapid clinical progression and destruction of bone is completed before the end of growth. A review of the literature is presented with a view in particular to useful classification of the different types of osteolysis. A case followed up at our clinic for surgery of the hand is described and discussed.


[Are automatic devices suitable for blood pressure determinations?]. Four automatic blood pressure recorders (Bosograph II, Bosch EBM 500, Elag BE 237R, and Physiometrics SR-2) were compared with the random zero sphygmomanometer. Since each of the automatic devices was calibrated for phase IV, diastolic blood pressure values were read off at phase IV and not phase V of Korotkow with the random zero sphygmomanometer. Blood pressure measurements were carried out in 80 patients with hypertension and in 20 normotensive healthy subjects. Readings with the automatic recorders and with the random zero sphygmomanometer correlated well in a wide range of systolic and diastolic blood pressure (r = 0.878--0.982, p less than 0.001). However, the automatic values were in most cases significantly lower than those obtained with the random zero device. For Physiometrics SR-2, where two diastolic readings were possible, only the first diastolic values correlated well with phase IV of Korotkow. The second values were significantly lower, with a difference of -11.1 mm Hg, and probably did not reflect the true diastolic blood pressure. These results show that each of the four automatic recorders is suitable for measuring blood pressure. However, with the Physiometrics SR-2, Only the higher diastolic reading should be used. The differences between the four automatic devices were minor and can therefore be ignored.


[Thorotrastosis and thorotrast carcinoma of the kidney. A differential diagnostic problem]. Thorotrast deposts produce intense fibrosis and it is not uncommon for malignant tumors to arise in such cases. Thus for example, renal carcinoma was observed 35 years after administration of Thorotrast. Such carcinomas may be difficult to diagnose in time because of radiogenic nephritis. In the light of experience with a 55-year old man, the reason for delayed carcinoma diagnosis was lack of formation of tumor nodes due to intense fibrosis resulting in diffuse and canalicular tumor spread. Hence it is obvious that angiography may not be diagnostic in such cases.


[Bronchoscopy with a rigid tube, an obsolete method?]. Of the two methods of bronchoscopy, the rigid bronchoscope and the flexible instrument, it is clear that one cannot be used to the complete exclusion of the other. Both methods have their advantages and disadvantages. The rigid tube has many diagnostic and especially therapeutic advantages in the main bronchi, while the flexible instrument displays its strong points in the peripheral areas. The two methods complement one another. Bronchofiberscopy alone cannot be recommended, but if it is carried out nevertheless it is merely a general bronchoscopy and the limitations must be taken into consideration. It must be possible to deal with any complications which may arise.


[Intravascular uterine leiomyomatosis].

[Intravascular uterine leiomyomatosis]. Intravascular (intravenous) leiomyomatosis is a rare uterine neoplasm. The unusual growth and extension of histologically benign smooth muscle tumors in vascular channels of uterus and pelvis are cardinal features of the disease. The course of the affection has been benign in the majority of the cases reported in the literature. Clinical and pathologic aspects are briefly evaluated in the context of an example of intravascular leiomyomatosis in a 30-year-old woman.


Serial serum amylase levels in patients with pancreatic pseudocysts. The incidence of hyperamylasaemia in serial serum amylase levels from patients with pancreatic pseudocysts is not well documented in the literature. Accordingly serial amylase levels were estimated in 5 patients with proven pancreatic pseudocysts. The majority of the values were normal or only minimally elevated. In contrast the amylase thermolability was persistently elevated and appeared to be a more sensitive measurement than serum amylase activity for indicating the presence of pancreatic pseudocysts.


Sulphonylureas and cardiovascular disease: a problem for few diabetics. Because of the doubts cast on the safety of the sulphonylureas we analysed 1000 consecutive referrals to a diabetic clinic to identify the number of new patients equally suitable for treatment with a sulphonylurea or insulin. After excluding previously diagnosed and treated diabetics and those with a non-diabetic glucose tolerance test there were 531 new diabetics. Youth and insulin dependency, old age or obesity accounted for 390. A further 40 required diet alone, 50 had concomitant disease or socio-domestic circumstances influencing treatment choice, and 10 had secondary diabetes. Thus, only 41 diabetics (7.7% of new patients or 4.1% of total clinic referrals) appeared suitable for optional sulphonylurea or insulin therapy. We conclude that there are relatively few diabetics for whom the questionable safety of the sulphonylureas poses a therapeutic problem, and equally few who would be available for any further long-term, random-allocation trials of their effects upon the cardiovascular system.


Medical treatment of breast cancer.

Medical treatment of breast cancer. Medical treatment is potentially more important than surgical treatment for the large majority of patients presenting withe breast cancer. Since each patient has unique characteristics affecting both tumour aggressiveness and host defence, a generalised approach to medical treatment is no longer acceptable.


Infection and immunization.

Infection and immunization. Herd infections, especially in children, are strongly influenced epidemiologically by social and demographic factors which have contributed favorably to a general decline in incidence and mortality during the past 50 years or more. Intervention procedures such as immunization cannot be evaluated or planned realistically except against these background factors. Assessed in this way, immunization against diphtheria and poliomyelitis was unequivocally effective in reducing incidence and morbidity of these diseases. By comparison, pertussis vaccine has a very limited protective effect, the value of which, as morbidity decreases, may be offset by the intrinsic toxicity of the vaccine and by the possibility of infrequent but severe brain damage in some children.


The problems, diagnosis and treatment of infection by Staphylococcus aureus. Present-day problems of infection by Staphylococcus aureus are described against a brief historical account of the evolution of the multiple antibiotic resistant 'hospital staph'. which caused such immense problems of hospital cross-infection in the 1950's and 1960's. These problems have lessened considerably since that time, but staphylococcal infection still remains as a cause of morbidity and mortality. Diagnosis and treatment are not always straight-forward. Apart from applying general supportive measures, and appropriate surgical intervention when necessary, the attending doctor is faced with making a choice from a multiplicity of antibiotic agents. A brief account of the main antibiotic agents currently available is given with comments on some of the disadvantages and complications attendant on their use. The potential dangers of staphylococcal sepsis and the need for rapid diagnosis and prompt vigorous treatment are stressed.


Sleep and hypnotics.

Sleep and hypnotics. Sleep is an enigma and the clinical importance of disturbed sleep is not clear. Much has been learnt in the past 25 years of the physiology of normal and abnormal sleep. Complaints of insomnia can be related to several causes--normal extreme patterns, psychiatric, physical, specific and drug-related. The treatment of insomnia is essentially that of the primary condition. Hypnotics have a limited role and their use should always be carefully considered.


Intestinal obstruction in pregnancy.

Intestinal obstruction in pregnancy. Intestinal obstruction is an unusual complication of pregnancy, but may be encountered more frequently in the future. Two patients with such a complication are described. Relief of the obstruction was achieved by surgical intervention in one patient and by delivery of a term baby in the other. The management of intestinal obstruction in late pregnancy is discussed.


Giant trichobezoar--an unusual case.

Giant trichobezoar--an unusual case. It has been known for several thousand years that concretions of animal and vegetable matter form in the stomachs and intestines of certain animals. These objects are known as bezoars. The finding of such curiosities in man is also recognised but is rare. A short history of bezoars is given and a case of a giant trichobezoar reported. The medical, surgical and psychiatric aspects are discussed.


Amyloidosis in Hodgkin's disease: a Scottish survey. Hodgkin's disease is a rare cause of secondary amyloidosis. In Scotland in the period 1961 to 1974 four patients in whom these 2 conditions were associated have been identified. In one of these the presence of amyloidosis was an unexpected finding at a staging laparotomy for Hodgkin's disease. The clinical and pathological features are summarised. The development of amyloid disease is usually suspected by the finding of proteinuria, which is rarely present in uncomplicated Hodgkin's disease. A distinction is made between a nephrotic syndrome due to glomerulopathy, which is an early complication of Hodgkin's disease and improves with treatment of the primary condition, and the nephrotic syndrome due to amyloidosis which occurs late in the course of the illness and is irreversible and rapidly progressive.


Temporal arteritis. A 14-year epidemiological, clinical and prognostic study. A total of 136 patients with histologically proven temporal arteritis were seen in the Lothian Region of Scotland in the 14-year period, 1964-77. This study is a review of these cases with particular reference to incidence, age, sex, seasonal occurrence, along with clinical features, general and visual prognosis. It also comments on treatment, the adverse effects thereof, and the differential diagnosis. A seasonal effect significant at the 1 per cent level was established with a peak occurrence in January.


Effect of a coronary care unit on mortality from acute myocardial infarction. The mortality from acute myocardial infarction was compared for 2 years before the introduction of a coronary care unit (C.C.U.), and three and a half years after. The difference was not significant statistically (18% before, and 15% after). There was no reduction in the incidence of cardiac arrest in the C.C.U. period, but resuscitation from cardiac arrest was more successful. The results are considered in the light of previous studies, and the current status of coronary care in district general hospitals is discussed.


Electroencephalography--use and abuse.

Electroencephalography--use and abuse. The E.E.G. is a reliable, safe and readily available test, especially for screening purposes in hospitals where brain scan and EMI scan facilities are not available. Its reliability becomes less when unreasonable demands are made regarding the nature of pathology, precise localisation and extent of a lesion. A detailed clinical history is mandatory for the neurophysiologist to make a useful interpretation of the E.E.G.


Cystic fibrosis in adolescents and young adults. With the early diagnosis of cystic fibrosis and the better management of these patients in childhood increasing numbers are surviving to adult life. The main problem requiring continuous medical care in the older cystic fibrosis patient is persisting and often progressive chest disease. For this reason the cystic fibrosis clinic for adolescents and young adults was started in the Western Infirmary in 1975. This paper presents our observations on 13 patients who had attended between 1975 and 1977. Eleven patients are alive and well and have shown no evidence of deterioration over this period. Ten are at school or in regular employment. With optimum medical supervision it is possible to give young adults with cystic fibrosis a worthwhile existence.


A study of patients with abdominal symptoms of undefined cause. This paper describes the results obtained from a study of 14 patients with symptoms of abdominal pain, nausea and vomiting which had continued for considerable periods of time and which, despite extensive investigation, eluded diagnosis. The study sought to examine the characteristics of patients who continue to suffer these symptoms and to identify their social and psychological effects. It was found that this symptom complex disrupted roles and activities in a manner out of proportion with clinical seriousness. Results from this preliminary investigation seem to point in the direction of two distinguishable groups of patients in whom the emergence and prognosis of symptoms are different. In one group, symptoms appear to be precipitated and exacerbated by problems within the environment and which disappear when such problems are ameliorated; in the other group symptoms appear as part of a long-term psychiatric illness. Implications for management are discussed.


Response to starvation before and after a jejuno-ileal bypass operation for morbid obesity. A greater metabolic response developed during a seven day starvation in two morbidly obese patients three months after a 90 per cent jejuno-ileal bypass operation when compared with a similar fast before operation. There was a greater degree of ketosis, a decreased urinary urea excretion and an earlier utilization of ketone bodies. These changes suggest a metabolic adaptation of the body to the semistarvation state caused by the operation with a more rapid utilization of adipose tissue as a fuel and a sparing of lean body mass.


Medical care for the homeless--some experience in Glasgow. The experience of running a medical clinic using voluntary help for the homeless is described. As a group they have limited access to normal medical channels despite high morbidity. In particular psychiatric illness, most frequently related to alcohol abuse, infestation, respiratory disease and problems due to poor foot care present commonly. No major administrative problems were encountered. The effects of such special arrangements for the homeless are assessed.


Clinical and metabolic features of overdosage with Amesec. A 23-year-old woman ingested 2g. amylobarbitone, 10.4g. aminophylline and 2g. ephedrine. She was deeply unconscious, hypothermic, and went on to have supraventricular and ventricular dysrhythmias, convulsions and haematemesis. During the last convulsion she aspirated vomitus and died. The peak plasma concentration of amylobarbitone was 19mg. per l. and those of ephedrine and theophylline were 13 times higher than accepted therapeutic levels. During the course of the poisoning marked hypokalaemia (1.8mmol./l.) and hyperinsulinaemia (greater than 240mU./l.) were found in conjunction with mild hyperglycaemia (9.6mmol./l.) and elevation of free fatty acid levels (1860mumol./l.). The mechanism of these changes is discussed.


Air pollution, hygiene and health of Danish schoolchildren. A comprehensive investigation forming part of a joint European study under the auspices of "WHO Long-Term Air Pollution Programme" uses 7-13 year old schoolchildren as the target group. The study has included social, housing, hygienic and epidemic factors as well as family smoking habits. The results indicate that, at exposure to low levels of air pollution, these factors dominate as causes for the impairment of health especially that of respiratory health.


Geochemical provinces and the incidence of dental diseases in Sri Lanka. A survey carried out on the incidence of dental diseases and the distribution of fluoride in drinking water wells in Sri Lanka shows that 3 areas in particular had abundant fluoride (greater than 2ppm). Dental fluorosis was common in areas with high fluoride content while those areas with very little or no fluoride, such as the central region of Sri Lanka, had a high incidence of dental caries. The intensity of rain fall played a major role in the leaching of fluoride ions from soils and it is perhaps this factor which is responsible for the occurrence of a low fluoride zone in the central part of Sri Lanka. The presence of areas containing high fluoride and hence dental fluorosis coincided with geochemical provinces. In these areas, mineral deposits such as apatite and serpentine and also hot spring regions with exhalations of fluorine are found.


Determination of polycyclic aromatic hydrocarbons in sediments and mussels from Saudafjord, W. Norway, by glass capillary gas chromatography. Polycyclic aromatic hydrocarbons (PAH) have been determined, by glass capillary gas chromatography, in two species of bivalves (Mytilus edulis and Modiolus modiolus) and sediments of Saudafjorden, Norway. The PAH observed are derived from waste effluents from a ferro alloy smelter. Up to 34 PAH compounds were identified, including some reported to be carcinogenic. The concentrations decreased rapidly with distance from the source and with sediment depth, but could be traced more than 15 km from the source. Relative abundance of various PAH did not change significantly in the mussels collected from the head to the mouth of the fjord. In the sediments, however, phenanthrene increased from minor importance to dominance towards the mouth, whereas the relative content of anthracene and benzo [a]pyrene decreased. The results are compared with observations from other marine localities and discussed in relation to transport processes, biodegradation and chemical transformation in the sediments.


Instrumental analysis of trace elements in thumbnails of human subjects. Human thumbnails were analyzed for trace elements by instrumental analysis using thermal neutron activation technique. The average concentration of metals studied in clinically symptom-free adult female and male subjects were: zinc, 184 vs. 153 ppm; chromium, 6.8 vs. 4.2; selenium, 0.9 vs. 0.6; gold, 2.6 vs. 0.4; mercury, 1.9 vs. 0.4; silver, 0.7 vs. 0.3; cobalt, 0.07 vs. 0.04. A summary of literature reported concentration of metals in human nail is also presented.


End-capillary loops in the heart: an explanation for discrete myocardial infarctions without border zones. Separate perfusions of canine coronary arteries with colored silicone-rubber compound reveal that in the region where two microcirculations abut, capillaries derived from individual large vessels are discrete, with no interconnections. Terminal homologous capillaries from loops rather than anastomosing with heterologous capillaries. This anatomic arrangement may account for discrete myocardial infarctions without ischemic border zones.


Intestinal absorption of immune complexes by neonatal rats: a route of antigen transfer from mother to young. Horseradish peroxidase (HRP) in the presence of specific immunoglobulin G antibody to HRP is selectively absorbed from the gut lumen and transferred by intestinal epithelial cells to the lamina propria in newborn rats. The HRP is not transferred in detectable amounts in the absence of the antibody. Transport of maternally derived antigen via antigen-antibody complexes may have important influences on the developing immune system in young mammals.


Water, protein folding, and the genetic code. The absolute affinities of amino acid side chains for solvent water closely match their relative distributions between the surface and the interior of native proteins and are associated with a remarkable bias in the genetic code.


Candidiasis: detection by gas-liquid chromatography of D-arabinitol, a fungal metabolite, in human serum. D-Arabinitol was identified as a major metabolite of Candida species in human subjects. Gas-liquid chromatography was used to measure the concentration of D-arabinitol in serum. The study included subjects who were healthy and cancer patients who had proven invasive candidiasis or were colonized with Candida. D-Arabinitol concentrations greater than 1.0 microgram per milliliter were found in serum from patients with invasive infection. This technique may prove valuable in the diagnosis of invasive candidiasis.


Response of cat inferior colliculus neurons to binaural beat stimuli: possible mechanisms for sound localization. The interaural phase sensitivity of neurons was studied through the use of binaural beat stimuli. The response of most cells was phase-locked to the beat frequency, which provides a possible neural correlate to the human sensation of binaural beats. In addition, this stimulus allowed the direction and rate of interaural phase change to be varied. Some neurons in our sample responded selectively to manipulations of these two variables, which suggests a sensitivity to direction or speed of movement.


Moment of inertia: psychophysical study of an overlooked sensation. The distribution of mass in an object held in the hand, as described by its moment of inertia, is a fundamental and potent but largely unrecognized contributor to the object's "feel." A limited set of experiments has produced Weber fractions for human differential sensitivity to this property in the approximate range of 1/5 to 1/3, which is about ten times the Weber fraction reported for lifted weights.


Endothermy and activity in vertebrates.

Endothermy and activity in vertebrates. Resting and maximal levels of oxygen consumption of endothermic vertebrates exceed those of ectotherms by an average of five- to tenfold. Endotherms have a much broader range of activity that can be sustained by this augmented aerobic metabolism. Ectotherms are more reliant upon, and limited by, anaerobic metabolism during activity. A principal factor in the evolution of endothermy was the increase in aerobic capacities to support sustained activity.


Chrysotile asbestos in a California recreational area. Dustfall along roads and trails being used recreationally in the Clear Creek area of San Benito County, California, located in the New Idria serpentinite, was found to be 90 percent or more chrysotile asbestos. Personal samplers worn by motorcyclists using one of the trails showed concentrations of airborne fibers ranging from 0.3 to 5.3 fibers per milliliter, according to methods prescribed for monitoring occupational exposures. The present workplace standard for brief exposures to asbestos is 10 fibers per milliliter; 5 fibers per milliliter is the proposed standard. The average total dust concentration estimated from personal samplers was approximately 20 milligrams per cubic meter of roughly 90 percent chrysotile. To our knowledge, this is the first demonstration of asbestos exposures of this magnitude, in size ranges known to be pathogenic, resulting from natural deposits not associated with mining, milling, or industrial use.


Angular invariants in developing human mandibles. Recent studies of lateral cephalograms based on symmetric-axis analyses of the mandibular border yield angles that appear to be uninfluenced by gross changes in mandibular shape over age and between individuals.


Xenopus liver: ontogeny of estrogen responsiveness. Estradiol-17 beta stimulates the synthesis of numerous proteins exported into the culture medium by Xenopus tadpole liver tissue obtained after stage 50 and throughout metamorphosis to stage 66. Although estrogen-induced vitellogenin can be detected as early as stage 54, it is a minor percentage of the exported proteins until after the completion of metamorphosis. In hepatic tissue obtained after metamorphosis, the hormone evokes the synthesis of vitellogenin specifically without affecting the labeling of other secreted proteins.


Phase resetting and annihilation of pacemaker activity in cardiac tissue. Spontaneous rhythmic activity in isolated cardiac pacemaker cells can be terminated by a brief, subthreshold, depolarizing or hyperpolarizing perturbation of the proper magnitude applied at a specific point in the pacemaker cycle. Evidence is provided in support of a topological theory of the existence of a "singular" point in cardiac oscillators.


Monocular light exclusion for a period of days reduces directional sensitivity of the human retina. Single eyes of young adult observers were occluded for as long as 10 days. Directional sensitivity of the retina (the Stiles-Crawford effect of the first kind) under photopic conditions was dramatically reduced at every retinal location tested in all subjects. The maximum effect was observed within 3 to 5 days, and recovery took place at approximately the same rate after termination of patching.


Microsecond sensitivity of the human visual system to irregular flicker. A flickering light presented to the eye produces a small alternating voltage at the scalp of a subject. This alternating voltage indicates the following response of the brain to the flicker. If every other flash in the flicker is displaced temporally by as little as 30 microseconds, an asymmetry appears in the brain's alternating voltage. The results suggest an underlying mechanism that may enhance visual detection of high-frequency flicker.


Functional organization of lateral geniculate cells following removal of visual cortex in the newborn kitten. When the visual cortex of a newborn kitten is removed, most neurons in the dorsal lateral geniculate nucleus degenerate, but a small population of large cells is spared. Electrophysiological recording revealed that detailed visual topography in the nucleus is abnormal and that single cells have unusually large receptive fields. These results suggest that optic axons deprived of their normal synaptic targets rearrange their connections to converge on local surviving neurons.


Molecular microanalysis of pathological specimens in situ with a laser-Raman microprobe. A laser-Raman microprobe has been used to identify microscopic inclusions of silicone polymer in standard paraffin sections of lymph node. This example of organic chemical microanalysis in situ in pathological tissue represents an extension of microanalytical capabilities from elemental analysis, performed with electron and ion microprobes, to compound-specific molecular microanalysis.


Lens epithelial cell elongation in the absence of microtubules: evidence for a new effect of colchicine. Embryonic chick lens epithelial cells cultured in serum-supplemented medium elongated in the absence of microtubules after treatment with the antimicrotubule drug nocodazole. Colchicine, at concentrations lower than those that dissociate microtubules, blocks cell elongation and the associated increase in cell volume. These results indicate that an increase in cell volume, not microtubules, is responsible for lens cell elongation and suggest a previously undescribed effect of colchicine on cell volume regulation.


Triglyceride concentrations: the disaccharide effect. The mean 24-hour or integrated concentration of triglyceride is significantly higher when dietary sucrose is provided rather than an equivalent amount of its component monosaccharides, glucose and fructose. In contrast, the plasma triglyceride concentration after a 12-hour fast is not significantly different.


Fluidity of the rat liver microsomal membrane: increase at birth. The lipid apparent microviscosity of the rat liver microsomal membrane on the first day after birth was found to be half of that observed on the last day of fetal life. This remarkable perinatal fluidization of the membrane resulted from a marked increase in the molar ratio of phospholipids to cholesterol.


Tumor location detected with radioactively labeled monoclonal antibody and external scintigraphy. Murine teratocarcinomas were located in mice by external gamma-ray scintigraphy with an iodine-125-labeled monoclonal antibody specific to the tumors. The specificity of the method was increased by subtracting the radiation produced by an iodine-125-labeled indifferent monoclonal antibody of the same immunoglobulin class as the tumor-specific antibody.


Activation of the supplementary motor area during voluntary movement in man suggests it works as a supramotor area. Measurements of cerebral blood flow in man revealed that complex voluntary movements are associated with a blood flow increase in the supplementary motor area of the brain. This increase is additional to and similar in magnitude to the Rolandic sensorimotor area activation that occurs during all kinds of movement. When subjects counted silently there was no activation of any focal cortical area in the brain; when they counted aloud there was a marked increase in activity in the supplementary motor area. These results are consistent with the hypothesis that the supplementary motor area plays a major role in the initiation and control of at least some kinds of voluntary movement in man and is, therefore, a motor center of a higher order than the primary Rolandic areas.


Calcitonin: inhibitory effect on eating in rats. Subcutaneous and intracerebral injections of calcitonin inhibited feeding in rats. The anorectic activity of calcitonin was destroyed by exposing the hormone to heat, trypsin, or hydrogen peroxide. Calcitonin did not produce a conditioned taste aversion to saccharin, and maximum inhibition of feeding occurred 4.5 to 8.3 hours after subcutaneous administration. It is concluded that calcitonin inhibits feeding by acting directly on the central nervous system.


Humans deprived of normal binocular vision have binocular interactions tuned to size and orientation. A suprathreshold grating presented to one eye elevated the threshold for the discrimination of gratings similar in size and orientation presented to the fellow eye. The magnitude and stimulus specificity of these binocular interactions in human observers with normal bioncular vision were similar to those in observers deprived of normal binocular visual experience; however, the latter showed a failure of binocular summation at threshold or subthreshold contract levels. Whereas strabismus or amblyopia disrupted the normal excitatory interactions between the two eyes, cortical inhibitory binocular connections seem not to have been disrupted.


Dendritic growth in the aged human brain and failure of growth in senile dementia. Golgi-stained dendrites of single randomly chosen layer-II pyramidal neurons in the human parahippocampal gyrus were quantified with a computer-microscope system. In nondemented aged cases (average age, 79.6 years), dendritic trees were more extensive than in adult cases (average age, 51.2), with most of the difference resulting from increases in the number and average length of terminal segments of the dendritic tree. These results provide morphological evidence for plasticity in the mature and aged human brain. In senile dementia (average age, 76.0), dendritic trees were less extensive than in adult brains, largely because their terminal segments were fewer and shorter. Cells with shrunken dendritic trees were found in all brains. These data suggest a model of aging in the central nervous system in which one population of neurons dies and regresses and the other survives and grows. The latter appears to be the dominant population in aging without dementia.


A structural model for the kinetic behavior of hemoglobin. The tertiary structures of all liganded hemoglobins in the R state differ in detail. Steric hindrance arising from nonbonded ligand-globin interactions affects the binding of ligands such as CO and cyanide which preferentially form linear axial complexes to heme; these ligands bind in a strained off-axis configuration. Ligands such as O2 and NO, which preferentially form bent complexes, encounter less steric hindrance and can bind in their (preferred) unstrained configuration. Linear complexes distort the ligand pockets in the R state (and by inference, in the T state) more than bent complexes. These structural differences between linear and bent complexes are reflected in the kinetic behavior of hemoglobin. Structural interpretation of this kinetic behavior indicates that the relative contributions of nonbonded ligand-globin interactions and nonbonded heme interactions to transition state free energies differ for linear and bent ligands. The relative contributions of these interactions to the free energy of cooperativity may also differ for linear and bent ligands. Thus the detailed molecular mechanism by which the affinity of heme is regulated differs for different ligands.


Neuronal chemotaxis: chick dorsal-root axons turn toward high concentrations of nerve growth factor. Micropipettes containing 2 to 50 biological units of beta growth factor (NGF) were placed near growing axons of chick dorsal-root ganglion neurons in tissue culture. The axons turned and grew toward the NGF source within 21 minutes. This turning response to elevated concentrations of NGF appears to represent chemotactic guidance rather than a general enhancement of growth rate.


Differential competition with cytotoxic agents: an approach to selectivity in cancer chemotherapy. An approach to increasing the selectivity of cancer chemotherapeutic agents is presented in which noncytotoxic competitive substrates are used to discern the differences in structural requirements for transport of cytotoxic agents between tumor cells and a sensitive host tissue, the hematopoietic precursor cells of the bone marrow. Examples are given for two such systems, one responsible for the transport of nucleosides and another for the transport of amino acids. Cytidine is twice as effective in reducing the toxicity of showdomycin for murine bone marrow cells in culture as it is for murine L1210 leukemia cella. Conversely, homoleucine is twice as effective in reducing the toxicity of melphalan for L1210 cells as it is for bone marrow cells. These observations can serve as a basis for the development of bone marrow protective agents and for the design of cytotoxic agents that may be preferentially transported into tumor cells.


Elimination of metabolic cooperation in Chinese hamster cells by a tumor promoter. Wild-type Chinese hamster V79 cells (6-thioguanine-sensitive) reduce the recovery of 6-thioguanine-resistant cells when they are cultured together at high densities, through a form of  intercellular communication (metabolic cooperation). Cooperation is inhibited by 12-O-tetradecanoyl phorbol-13-acetate, rescuing the 6-thioguanine-resistant cells. These results may be useful in the study of an aspect of the mechanism of tumor promotion and in assaying for promoters.


Noncycling tumor cells are sensitive targets for the antiproliferative activity of human interferon. Resting Burkitt's lymphoma cells (Daudi) in culture are more sensitive targets for the antiproliferative activity of purified human fibroblast interferon than cells that are rapidly multiplying. Thus, interferon may be of significant clinical value in neoplasms involving stem cells and, after chemotherapy, in suppressing the reemergence of tumors.


Cortical plasticity in monocularly deprived immobilized kittens depends on eye movement. A marked reduction of binocular cells in striate cortex is found if 4-week-old kittens are visually stimulated monocularly while anesthetized and held in a stereotaxic apparatus. If the kittens are paralyzed and artificially respirated, changes are not found unless an eye is moved mechanically. It appears that eye movement and visual stimulation are necessary conditions for deactivation of binocular connections, but neither is sufficient to induce such changes alone.


Inbreeding and juvenile mortality in small populations of ungulates. Juvenile mortality of inbred young was higher than that of noninbred young in 15 of 16 species of captive ungulates. In 19 of 25 individual females, belonging to ten species, a larger percentage of young died when the female was mated to a related male than when she was mated to an unrelated male.


Parabolic flight: loss of sense of orientation. On the earth, or in level flight, a blindfolded subject being rotated at constant velocity about his recumbent long body axis experiences illusory orbital motion of his body in the opposite direction. By contrast, during comparable rotation in the free-fall phase of parabolic flight, no body motion is perceived and all sense of external orientation may be lost; when touch and pressure stimulation is applied to the body surface, a sense of orientation is reestablished immediately. The increased gravitoinertial force period of a parabola produces an exaggeration of the orbital motion experienced in level flight. These observations reveal an important influence of touch, pressure, and kinesthetic information on spatial orientation and provide a basis for understanding many of the postural illusions reported by astronauts in space flight.


Conditioned tolerance to the hypothermic effect of ethyl alcohol. Results from experiments with rats support the proposition that tolerance to the hypothermic effect of alcohol involves the Pavlovian conditioning of compensatory responses. Tolerance was substantially reduced when alcohol was administered in an environment that had not been associated with alcohol. Direct evidence of a conditioned hyperthermic compensatory response was found.


Inactivated Proplex for the haemophiliac with inhibitors. A case report. Inactivated prothrombin complex (Proplex) with a Kingdon time between 100 and 138 seconds effected functional recovery and adequate haemostasis in a haemophiliac with inhibitors of the high-responder type at comparatively low cost, and with no adverse effects. Home treatment was successful. Liver function remained normal during treatment. Statistically significant changes occurred in the prothrombin time (PT), fibrinogen levels and the thrombin time after each infusion. No evidence of diffuse intravascular coagulation (DIC) was ever detected. The inhibitor level decreased from 10 to 2 Bethesda units, and the radio-immunoassay (RIA) for Australia antigen remained negative.


The presentation of malignant melanoma.

The presentation of malignant melanoma. Survival figures for patients with malignant melanoma in South Africa compare rather unfavourably with those from other countries, for example Queensland, Australia. The chief reason for this seems to be the late stage at which patients present with the tumour and hence the late diagnosis of melanoma in this country. A series of patients was studied and note was taken of their presenting symptoms and signs, which included growth of a pigmented lesion, bleeding, darkening, pain, tenderness and itching. Ulceration and satellitosis had developed in a small proportion of cases. Awareness of this tumour and education as to the circumstances in which it should be suspected should be encouraged, so as to ensure earlier diagnosis and treatment and thus higher survival rates.


Radiocolloid imaging in primary liver cancer and amoebic liver abscess. Accuracy of differential diagnosis and extent of inter-observer variability. Radiocolloid liver scans from 58 patients with primary liver cancer and 56 patients with amoebic liver abscess were examined 'blind' and independently by three nuclear physicians and one registrar in training in order to evaluate the accuracy of the differential diagnosis between the two conditions and to assess the extent of inter-observer variability in the interpretation of these scans. Each of the observers incorrectly interpreted about 12% of scintiphotographs and at least one observer was wrong in 25% of the scans. The difference in diagnostic accuracy between individual observers was not statistically significant. Observers disagreed in 21,6% of the scans. The main reasons for misdiagnosis were failure to realize that excessive extrahepatic uptake of radiocolloid can occur with liver abscesses, and the indistinguishable appearance of the defect or defects in some cases of primary liver cancer and amoebic liver abscess. This margin of error and of inter-observer variability must be borne in mind when interpreting liver scans of patients thought to have either primary liver cancer of amoebic liver abscess.


Rheumatoid arthritic syndrome after chikungunya fever. An outbreak of chikungunya fever which occurred during April 1977 among a group of high-school children from Pretoria after a visit to the northern Transvaal bushveld is reported. Some of the adults who accompanied the pupils also contracted the disease. The adults suffered more severely from the chronic arthritic form of the disease than did the children. In some cases the episodic polyarthritis was still present 18 months after the onset of the disease. Rheumatoid factors in low titre could be demonstrated in the circulation of patients with longstanding symptoms.


Spontaneous rupture of the liver associated with pregnancy. A report of 5 cases. A resume of the aetiology, precipitating factors, pathology and management of spontaneous rupture of the liver in pregnancy, with a report of 5 cases, is presented. Misdiagnosis and late treatment contribute to the high mortality rate. Pre-operative diagnosis is very rare despite the fact that this is a diagnosable syndrome in pregnant multiparas with evidence of pre-eclampsia or eclampsia, and right-sided hypochondrial or epigastric pain which rapidly progresses to peripheral vascular collapse, often with signs of intraperitoneal haemorrhage. An awareness of this syndrome and early active surgical management constitute the best and only chance of survival for these patients.


Cirrhosis of the liver associated with inferior vena-caval obstruction. Seven patients with inferior vena-caval obstruction associated with cirrhosis of the liver are described. Inferior vena-caval obstruction is suggested when an enlarged azygous vein is seen on chest radiography, or when superficial collateral veins draining upwards are visible on the abdomen and chest. When a short obstruction or 'web' is present, this should be treated surgically. Venous thrombosis below the obstruction may result in occlusion of a long segment of the vena cava. Chronic suprahepatic venous obstruction may cause macronodular cirrhosis and predispose to the development of hepatocellular carcinoma.


Acute haemorrhagic cystitis and glomerulonephritis. Two patients presented with macroscopic haematuria and dysuria. Cytoscopic examination showed haemorrhagic cystitis. The findings of casts in the urine and of impaired renal function led to renal biopsies. These showed glomerulonephritis with deposits of IgA in the mesangium. No evidence of viral infection was found. A third patient diagnosed on biopsy 9 years previously as having focal glomerulonephritis developed gross haematuria and dysuria. Cystoscopy revealed haemorrhagic cystitis, and deposits of immunoglobulins were present in the bladder wall. It is suggested that haemorrhagic cystitis may occur as part of a syndrome with glomerulonephritis and may be due to an immunological mechanism.


The radiological features of lymphangioma-like Kaposi's sarcoma. A case report. A case of lymphangioma-like Kaposi's sarcoma is described, together with the lymphangiographic and arteriographic features. Persistent pleural effusions developed, for which a cause is postulated.


Curiosa paediatrica II.

Curiosa paediatrica II. A small series of a dermal curiosity occurring in children is described. It appears not to have been presented heretofore in medical writings and certainly not in our South African medical literature. The constancy of its presentation suggests strongly a genetic localization for its origin (if not a fanciful one!) and the name foveae scapularum cutaneae bilaterales congenitae in true dermatological fashion is wholly descriptive, ponderous though it be for such light 'residua pennarum'!


Susceptibility of Chlamydia trachomatis to antibiotics in vitro and in vivo. The susceptibility of Chlamydia trachomatis to antibiotics was studied in vitro and in patients with nongonococcal urethritis. The minimal inhibitory concentrations of cloxacillin, erythromycin, pivampicillin, oxytetracycline, and doxycycline, which were the most effective drugs, were 10, 0.5, 0.25, 0.1, and 0.5 microgram/ml, respectively. The clinical observations suggested that of the antibiotics studied, doxycycline, erythromycin, and trimethoprim-sulfamethoxazole were effective for treatment of chlamydial infection and nongonococcal urethritis. Trimethoprim-sulfamethoxazole seemed less efficient for treatment of patients with nongonococcal urethritis whose cultures were chlamydia-negative. Pivampicillin, although it was active in vitro against C. trachomatis, did not produce a satisfactory clinical response. Untreated patients had symptoms of urethritis and chlamydial infection for three weeks. Incubation periods of a week or less were recorded for about half of the patients who had nongonococcal urethritis, both those whose cultures were chlamydia-positive and those whose cultures were chlamydia-negative. However, a few patients in both groups reported incubation periods of four weeks or more.


Gonorrhea in street prostitutes: epidemiologic and legal implications. Sociodemographic characteristics of a group of street prostitutes in Colorado Springs, Colorado, were determined through retrospective chart review and compared with those of a group of nonprostitute women seen at a venereal disease clinic. Initially, the risk that prostitutes would contract gonorrhea was substantially higher than the risk for other women (31% vs. 21%) but the risks for both groups decreased over the two-year period during which control measures were applied. These measures included use of legal orders, based on the constitutional requirement of "least restrictive alternative." Prostitutes in this setting may well constitute a "core group" of transmitters.


Superimposed traumatic and gonococcal proctitis: report of two cases. Two men sought treatment at an emergency room with apparent gonococcal proctitis. Further evaluation after failure of antibiotic therapy in both patients revealed that rectal damage resulting from the patients' sexual habits had resulted in a severe traumatic proctitis. The discovery of several organisms, including Neisseria gonorrhoeae and two nonpathogenic amebas, was probably only incidental. Two points are emphasized: the importance of obtaining a complete sexual history for every patient treated for venereal disease, and the inherent complications associated with anorectal manipulation.


Income of the population aged 55 and older, 1976. This article inaugurates a biennial series of reports on the income of persons aged 55 and older. The survey on which it is based updates information on the broad economic picture for a cross-section of this population and forms the basis for an analysis of trends in the financial status of the group as a whole. In 1976, persons aged 55--61 were generally working full-time, not receiving income from pensions, and married. Those aged 73 and older were predominantly not working, mostly recipients of retirement pensions, and likely to be widows. Most persons aged 65 and older were receiving social security benefits; those with neither earnings nor a second pension constituted the largest subgroup and had the lowest median income. Married couples, as a group, were substantially better off financially than nonmarried persons because they were younger, two-person rather than one-person units, and had one member who was a man. Blacks were less likely than whites to receive pension income other than social security benefits, and their median benefits and earnings were both lower.


Gonococcal ophthalmia neonatorum after delivery by cesarean section: report of a case. This report describes a neonate delivered by cesarean section who had conjunctivitis due to Neisseria gonorrhoeae. Evidence supporting the hypothesis that gonococcal conjunctivitis can be acquired in utero is provided by this case study, which also emphasizes that saline lavage is inappropriate after instillation of AgNO3 into the neonate's eyes.


Antecedents of mortality among the old-age assistance population. This research is concerned with patterns of mortality and related risk conditions among noninstitutionalized recipients of old-age assistance. Survival status was determined by followup interviews in the 1974 Survey of the Low Income Aged and Disabled. Data obtained in initial interviews a year earlier were used as antecedent variables in the analysis. The general hypothesis that the overall death rate of recipients would be higher than the rate of persons aged 65 or older in the general population was not supported. Older white men had a significantly lower death rate than their population contemporaries. The opposite pattern was observed for older men other than white who had higher rates than their population contemporaries. Factors with significant association with mortality that were suggested by logit analysis included previous employment in construction industries, advanced age, greater household density, male sex, cancer, and heart trouble. Recipients who had lost the capacity to dress and were isolated from local support were also more likely to die. Survival factors included previous occupation as a farm operator, functional activity, and the ability to bathe and to care for self when ill.


Terminal cancer: a challenge for social work. The social worker interested in providing service to terminally ill cancer patients and their families must begin with careful self-assessment and with clarity about her goals. The tasks to which she can then address herself are: helping her clients (1) explore their feelings and behavioral options, (2) communicate as openly as possible with their significant others, and (3) become aware of resources outside themselves. A fourth task is helping her co-professionals from other disciplines increase their effectiveness.


Coping with childhood cancer: group intervention as an aid to parents in crisis. Groups aid parents in crisis by promoting adaptive coping. Group intervention with parents of children recently diagnosed with cancer has a positive effect on the families in the later stages of illness by helping the parents establish constructive patterns and encouraging them to use problem solving techniques.


An integration of psychosocial concepts into the education of general practitioners. Psychosocial concepts related to human growth and development, doctor-patient interactions, and the professional use of self were integrated into a course for general practice residents which was taught by an interdisciplinary team. The content of the course was divided into two sections: theoretical and applied. In the first part of the course, residents were exposed in a relatively structured way to a health-oriented epigenetic perspective of the human condition. This framework was discussed with a view toward increasing assessment and intervention skills. In the latter half of the course, residents' owen case material was used to stimulate discussion of affective blocks to the use of self in the doctor-patient relationship. It was the purpose of this course to foster a total person approach to patient presentations.


The teaching social worker in family medicine: a prototype for the hospital social worker? The need for physicians to receive training in interpersonal skills as well as in preventive medicine to aid them in recognizing and addressing the psychosocial aspects of illness and to facilitate the delivery of more comprehensive care to patients, has been addressed in the Department of Family Medicine and several other specialties. In January, 1978 the author surveyed social work members of the Society of Teachers of Family Medicine to determine their activities and responsibilities and to identify the experiences which have proven most helpful as a preparation for their positions on medical school faculties. Results of the survey are reviewed in light of possible implications for the future hospital social worker as a medical educator.


A family-oriented admission procedure on an inpatient psychiatric unit. The importance of family involvement during inpatient psychiatric treatment is slowly being realized. Effective and meaningful family work can be promoted if the admission process includes family members and attempts to define family issues. In this paper, an admission procedure which emphasizes and encourages family involvement is described and the process illustrated with a case summary.


Addiction and pregnancy: two lives and crisis. Medical service comes consistently into contact with the addicted family at a time critical for change: pregnancy and childbirth. Neonatal withdrawal is life-threatening for the infant and very unsettling to a mother's self-confidence and her parenting ability. Medical treatment for the drug abusing mother is best coordinated with psychosocial and drug treatment in order to minimize perinatal complications, to anticipate risks to the child and to support the mother in her maternal role. This article advocates comprehensive care for the pregnant addict. It is drawn from the author's experience in the Maternal Narcotics Addiction and Child Development research project at Jefferson Davis Hospital, Houston, Texas.


Family adaptation to the traumatic spinal cord injury of a son or daughter. The article presents the case history of a family in which an adolescent son receives a traumatic spinal cord injury. The focus of the study is on the adaptation of the family unit to the permanent disablement of their dependent child. The family's grief reaction is examined as are their patterns of adaptation in family task organization, affection, communication, and power structures. The authors also discusses the effect of the injury on specific intrafamily relationships and presents suggestions for clinical intervention.


Complementation and noncomplementation in heterokaryons of three unlinked pigment mutants of the fowl. This study shows that melanocyte heterokaryons formed between cells of the blue and recessive white genotypes complement one another to produce normal pigmentation, while heterokaryons of the blue and pinkeye genotypes fail to complement. The simplest interpretation of these findings is that the blue and recessive white mutations affect different aspects of pigment synthesis so that when both kinds of nuclei exist in the same cytoplasm, they can correct (complement) each other's defect. On the other hand, the blue and pinkeye mutations, although unlinked, apparently affect the same aspect of pigment synthesis so that when both kinds of nuclei are in a common cytoplasm, they cannot correct each other's defect. This suggests that one of these two loci exerts some kind of control, or "regulation," over the other. It has previously been shown that recessive white--pinkeye heterokaryons can complement. Thus, only two heterokaryon complementation groups are evident within the three mutants examined.


Respiration-deficient Chinese hamster cell mutants: biochemical characterization. We have previously classified 35 of our respiration-deficient mutants into seven complementation groups and one "overlapping" mutant which does not complement mutants from groups I and II. In this paper we report on the biochemical characterization of representatives of complementation groups I, II, VII, and the "overlapping" mutant. We show that these mutants all have a defect in complex I of the electron-transport chain. The general features of these mutants are: (1) a low rate of O2 consumption in whole cells; (2) a low rate of release of 14CO2 from [2-14C] pyruvate, [1-14C] pyruvate, and [3-14C] beta-hydroxybutyrate; (3) a low rate of release of 14CO2 from [5-14C] glutamate and [1-14C] glutamate in mutants from groups II, VII, and the "overlapping" mutant, whereas a significant amount of 14CO2 is released in mutants from group I; (4) a substantial rate of release of 14CO2 from [U-14C] asparate; (5) in isolated mitochondria, succinate and alpha-glycerol phosphate stimulate O2 consumption whereas substrates which generate NADH, such as malate, do not; and (6) there is little or no rotenone-sensitive NADH oxidase activity in isolated mitochondria.


Characterization of the diphtheria toxin-resistance system in Chinese hamster ovary cells. Variations in two general classes of diphtheria toxin-resistant mutants which may be selected from Chinese hamster ovary (CH0-K1) cells and the conditions for their selection are described. The resistance of class I mutants can be overcome with increasing concentrations of toxin. Their entire complement of EF-2 is susceptible to ADP-ribosylation by toxin. Class I includes those strains in which resistance resides at the level of the plasma membrane. The resistance of class II, translational, mutants cannot be overcome by high concentrations of toxin, as all, or a portion, of their EF-2 is insensitive to the action of diphtheria toxin and Pseudomonas exotoxin A. Adjustment of the concentration of toxin used to select resistant mutants can be used to regulate the class of mutant recovered. Metabolic cooperation between cells does not affect recovery of either class I or class II mutants. Resistance is stable in class I strains, but class IIb strains, which possess 50% resistant and 50% sensitive EF-2, display a transient high level of resistance which is retained for varying lengths of time following exposure to toxin. Class IIa strains, which possess 100% resistant EF-2, grow normally in saturating concentrations of toxin, but class IIb strains grow at a reduced rate. Evidence is presented which suggests that the gene for EF-2 is functionally diploid in CHO-K1 cells.


Hyperparathyroidism following parathyroid autotransplantation. A patient with primary hyperparathyroidism underwent cervical exploration and hemithyroidectomy. Only one normal parthyroid gland was found and was removed. Hypercalcemia persisted and subsequent arteriography localized a large mediastinal adenoma which was excised. Parathyroid autotransplantation of a small part of this tissue was performed and the patient was well for over a year. He again became markedly hypercalcemic and graft-dependent elevation of parathromone levels was demonstrated. Autograft resection resulted in normocalcemia. Nineteen months later hypercalcemia and elevated parathormone levels prompted re-exploration of the graft site and another enlarged implant was removed. This restored normocalcemia and normal parathromone levels. Parathyroid adenomatous tissue has the potential for autonomous hyperfunction, and caution must be exercised in its use in autotransplantation.


Detection of carotid occlusive disease by ultrasonic imaging and pulsed Doppler spectrum analysis. Ultrasonic imaging of the cervical carotid arteries by ultrasonic arteriography and duplex scanning combined with pulsed Doppler spectrum analysis were investigated in a series of patients undergoing arteriography. By using the ultrasonic image as a guide for precise placement of the pulsed Doppler sample volume, the characteristics of blood flow at points of interest in the carotid arteries could be determined. Audible analysis of the Doppler signal permitted correct diagnosis of 23 of 26 (88%) high-grade stenoses or occlusions with ultrasonic arteriography and 24 of 26 (92%) with duplex scanning. Spectrum analysis of Doppler signals obtained with the duplex scanner detected all of the 22 high-grade stenoses. Spectral abnormalities of a lesser degree also were detected in 18 of 23 vessels (78%) with atherosclerotic plaques which should not have reduced cerebral blood flow. These techniques permit the accurate detection of and the distinction between high-grade stenoses and occlusion, as well as the identification of many plaques which are not large enough to affect intracranial hemodynamics.


Procoagulant activity of ascitic fluid in hepatic cirrhosis: in vivo and in vitro. Three cases of disseminated intravascular coagulation following infusion of ascitic fluid from the peritoneal cavity to the vascular system are reported in patients with hepatic cirrhosis. One of these was treated with intermittent drainage and infusion, and in the other two a LeVeen shunt was used. Studies on the ascitic fluid indicate the presence of a procoagulant material which would appear to be an activator of factor X. Preactivated factor X (Xa) from the fluid and/or a tissue factor activator of factor VII are additional possibilities.


Arterial regeneration following polyglactin 910 suture mesh grafting. A suture mesh of polyglactin 910 [Vicryl (polyglactin 910) suture mesh] was placed as a patch graft into the thoracic aorta of 23 growing pigs. In three other pigs the mesh was grafted in the form of a tube to replace a short aortic defect. The biological processes taking place in the grafted area were studied by morphological methods. The following observations were made: (1) Hemostasis readily occurred by fibrin, platelet, and erythrocyte embedding of the mesh. (2) Early outgrowth of smooth muscle cells around the mesh took place from the normal aortic media and from a newly formed subintimal smooth muscle layer. (3) The newly formed arterial tissue was completely endothelialized within 20 days. (4) The polyglactin mesh had disappeared almost completely at 40 days, but the new wall seemed to retain sufficient strength throughout the observation time. (5) Only irregular deposition of elastic fibrils occurred, but in other respects the new tissue structurally resembled normal arterial tissue.


Insulin resistance in peripheral tissues after a burn injury. The glucose uptake of a perfused, skin-covered preparation of muscle taken from the rat was altered by prior burn injury to the animal. Animals receiving an 8% deep burn to the back 24 hours prior to testing had a glucose uptake (5.9 +/- 0.85 microM/100 gm/min) which was depressed compared with control nonburned preparations (8.4 +/- 0.34 microM/100 gm/min) (P less than 0.025) at low insulin concentration (35 microU/ml). Higher insulin concentrations (160 microU/ml and 16 microU/ml) produced significant increases in the glucose uptake of both the burned and control animals. At the highest insulin level (16 microU/ml), there was no significant difference between burned and control animals. Preparations from animals burned five days prior to study showed a glucose uptake which was not decreased as compared with control animals at the low level of insulin (35 microU/ml) (7.4 +/- 0.62 microM/100 gm/min), but higher levels of insulin (160 microU/ml and 16 microU/ml) failed to produce a significant increase in glucose uptake (8.4 +/- 0.64 microM/100 gm/min and 8.6 +/- 0.92 microM/100 gm/min, respectively). The values differed significantly (P less than 0.05) from control preparation (11.5 +/- 0.54 microM/100 gm/min) at the insulin level of 16 microU/ml. Two different patterns of altered sensitivity to increased insulin concentrations were noted, depending on the stage of injury. The altered metabolic status of peripheral tissues does contribute to the insulin resistance pheonomenon observed after a burn injury.


A simplified and efficient method for treating varicose veins. Stripping the saphenous vein and manual excision of varicose veins has been the popular operative treatment for many years. During this 2- to 4-hour procedure, the patient must be rotated from the supine to the prone position in order to excise the collateral veins. These maneuvers are time-consuming and result in contamination, dozens of unsightly scars, and incomplete destruction of many of the small tortuous varicosities. In 705 patients we have substituted limited excision when possible and high-frequency cautery methods to destroy the venous tributaries. Cauterization, accomplished by introducing a probe subcutaneously through a 2 mm skin incision which requires no sutures for closure, affords excellent treatment for the troublesome smaller tortuous veins. The recurrence rate depends on the primary cause of the varicosities and is roughly the same in both types of operative procedures. The advantages of the latter procedure are shorter operating and anesthesia times, minimal infection rate, substantially less hospital time and cost, and essentially no cosmetic defects.


Obstruction of the ureter due to a false aneurysm. A false aneurysm arising from an aortofemoral bifurcation graft caused symptomatic ureteral obstruction in a 69-year-old woman. Following revision of the aortograft anastomosis, her symptoms and ureteral obstruction subsided. The prevention and treatment of ureteral complications following vascular surgery are discussed. Postoperative pyelograms may be indicated in the vascular bypass patient.


[First case of type D botulism in cattle in the Netherlands (author's transl)]. Report on an outbreak of botulism in six cows, in which Cl. botulinum toxin type D was found to be the cause for the first time in the Netherlands. Epidemiological studies showed that this outbreak of type D botulism was due to the fact that the litter used in the cubicles of the cows had been taken from a poultry farm in which cadavers of chicken were present, which contained up to 2 x 10(5) LD100 of Cl botulinum toxin type D per gram.


[A cow showing abnormal distension of the abdomen: omental bursitis (author's transl)]. A highly uncommon clinical picture in a cow showing abnormal distension of the abdomen as the most important clinical symptom, is described. The anatomy of the bovine adbomen is briefly reviewed, particular attention being paid to the omental bursa. This is followed by a discussion of the history and clinical symptoms. The owner complained of the fact that the cow showed loss of appetite and abnormal distension of the abdomen. The most important finding on clinical examination was made on rectal exploration, in which a large sac filled with fluid was felt in the abdomen. Exploratory laparatomy showed that this was an inflamed omental bursa containing a large quantity of serofibrinous exudate. This diagnosis was verified by pathological studies. The discussion is concerned with the differential diagnosis and a comparison is made with a number of similar cases reported in the literature.


[Cows which are unable to stand (author's transl)]. The most important features of the previous history and on examination, to which attention should be paid to ensure a correct diagnosis and prognosis in syndromes in which inability to stand is an outstanding symptom, are described.


[Rift Valley Fever, a Veterinary and Medical Problem (author's transl)]. Rift Valley fever probably occurred in East and South Africa for many years, where it occasionally caused sever epizootics among sheep and to a less extent in cattle and goats. Particularly newborn animals fall victims to the disease, whereas the majority of pregnant ewes and cows abort. In recent years, the disease spread to the Sudan and reached the Nile delta in 1977, where it not only caused an epizootic but also an epidemic among the population, resulting in approximately 18,000 cases and nearly 600 deaths. During the summer of 1978, the disease was observed again so that the virus must have overwintered in the newly infested area. The disease in animals and subsequently in man, displaying four different clinical forms, is discussed. The limited knowledge of the pathogenesis and epidemiology is stressed particular attention being paid to the Egyptian epizootic and epidemic. Because of inadequate knowledge of the clinical features, pathogenesis and other data, the disease among cattle was not detected until from five to six months after it had broken out. The spread of Rift Valley fever to the north-eastern part of Africa forms a potential threat of dissemination of the virus to neighbouring countries, situated on the two adjacent continents of Asia and Europe, and it is a real one. International travel and movement of goods and animals as well as the political situation in that area involves the danger of the Rift Valley fever virus also being transferred to new areas and becoming established there.


[Results obtained using an attenuated bovine syncytial virus vaccine against bronchopneumonia of yearlings (author's transl)]. Bronchopneumonia of yearlings is a respiratory infection with bovine respiratory syncytial virus (BRS virus) occurring as a herd disease in young cattle. In severe cases, the clinical picture is identifiable; characteristic features are laboured respiration and a high morbidity rate. Following an acute onset, atypical interstitial pneumonia is observed on postmorten examination and bacteriological studies are negative. An attenuated live BRS virus vaccine was used against bronchopneumonia of yearlings in 1976, 1977 and 1978. This vaccine was inoculated in twenty-six herds supervised by the present author and numbering approximately 1,200 animals in the sensitive period of life. Moreover, the results obtained by sixty practitioners on vaccinating approximately 13,000 animals in 1978 were collected. Conclusive evidence of the effectiveness of the vaccine was not provided by these field trials. However, it is concluded from the findings that the satisfactory results obtained in the majority of cases were not accidental and that these results suggest that BRS virus vaccine is very likely to have a protective action against bronchopneumonia of yearlings.


The activity of albendazole against adult and larval gastrointestinal nematodes in naturally infected calves in the Netherlands. The activity of albendazole against gastrointestinal helminths in naturally infected calves in the Netherlands was tested. The calves were in their first grazing season and kept in two groups of ten. One of these groups was grazed alternately with sheep. Five out of each group were drenched with albendazole (7.5 mg/kg) on the day they were housed (November 1). Before and 2, 14, and 28 days after treatment individual faecal samples were taken from all calves and larval cultures were made. Ten calves, six treated and four untreated, were killed for post mortem studies 14 days after treatment. The remaining calves were slaughtered 14 days later. The drug was highly effective in reducing the egg output, measured as the number of larvae cultured per gram of faeces. Compared with the untreated calves, the reduction was more than 99% two days after treatment, 100% at 14 days, and 99% after 28 days. It was shown that egg output 28 days after treatment came from worms which had developed from arrested larvae of Ostertagia ostertagi that had survived treatment. Post mortem results showed an efficacy of 100% against adult O. ostertagi, of almost 100% against Trichostrongylus axei, and 100% against adult and larval Cooperia oncophora. Twenty-eight days after treatment, the reduction of arrested early fourth stages of O. ostertagi was 85% in comparison with the untreated calves. Apparently less effect was found against Trichuris ovis at the given dose rate.


Isolated mitral valve replacement with the Björk-Shiley tilting disc prosthesis. Between July 1970 and June 1977, 151 patients underwent isolated mitral valve replacement with the Björk-Shiley valve. The follow-up period extended over 8 years to June 1978. Hospital mortality was 5.2% (8/151), late mortality 8.4% (12/143). Actuarial survival analysis predicts 84 (+/- 4) % of patients to be alive at 5 years and 80 (+/- 6) % at 8 years. Thirteen patients sustained 15 episodes of thromboembolic complications; actuarially 88 (+/- 4) % of patients were free from this complication at 5 years and 81 (+/- 8) % at 8 years. Other valve-related complications included paravalvular leak (7), prosthetion showed an improvement of at least one class in 84% of patients.


The diagnosis of acute renal failure (ARF) following cardiac surgery with cardio-pulmonary bypass. The diagnostic value of renal concentrating capacity expressed as free water clearance (CH2O), in comparison with other routine criteria for the early identification of acute renal failure (ARF), was evaluated in 1,203 adult patients undergoing cardiac surgical procedures. On the basis of the appearance of pathologic CH2O values in the range of -20 to 0 ml/hour or more positive, reversible or irreversible ARF was observed in 90 (= 7.5%) of our patients. Mortality in the presence of ARF was 47%; total ARF mortality was 3.5%. CH2O was pathologic for the first time on an average of 1.6 days after operation. In contrast, routine ARF criteria reported in the literature, such as serum urea and creatinine at varying substrate levels or oliguria, allowed diagnosis 1 to 5.5 days later. Moreover, these parameters only partially and less frequently met the criteria for ARF at the different levels. Likewise, the incidence of ARF decreased to a minimum of 1.7% and the total ARF mortality to 1.3%, depending on the severity of the criteria used. Altogether, the occurrence of pathologic CH2O values proved to be the earliest, most frequent and most reliable criterion for the recognition of ARF following cardiac surgery with cardiac-pulmonary bypass.


Frequency of hepatitis B after open heart surgery: a retrospective study over a three-year period (1974--1976). In spite of intensive efforts to reduce the risk of hepatitis B after heart operations, this complication is observed in 40 % or more of the cases. Over a period of three years (1974--1976) we examined 588 patients who had undergone open heart surgery. The following results were found: In 1974 the hepatitis frequency was 2.0 %, while in 1975 and 1976 it was 0.6 % hepatitis B and 0.6 % non-B hepatitis. We believe the reason for this improvement is a more careful selection of blood donors and their continuous control according to the following parameters: regular clinical observation; regular chest x-ray; determination of BSR, hemoglobin and aminotransferase; TPHA test; and search for antibodies. In 1974 hepatitis-B-surface-antigen (HBsAg) was detected by means of reverse hemagglutination tests. Since 1975 a modified radioimmunoassay has been used for this purpose. No donor blood with abnormal results was transfused, except for a very small number of extreme emergencies. The good results demonstrated can only be obtained by following the described program and by strictly avoiding pool preparations.


Ultrastructural and biochemical changes of human papillary heart muscle during different methods of induced cardiac arrest. To determine the protective effects of different methods of cardioplegia, studies on ATP/lactate levels and ultrastructure were performed in human papillary muscles obtained during mitral valve replacement. In group I (n = 5), plain ischemic arrest in hypothermia (systemic venous temperature = 24 degrees C) was accomplished. In group II (n =12), the heart was arrested by injection cardioplegia using magnesium-aspartate-procaine at systemic venous and myocardial temperatures of 24 degrees C. In group III (n = 12) Bretschneider infusion cardioplegia at systemic venous and myocardial temperatures of 26 degrees C and 19 degrees C respectively was applied. With regard to ultrastructural changes there were no clearcut differences in the three methods of hypothermic cardiac arrest after 60 minutes of ischemia. Ischemic changes tended to be slightest in group III (infusion cardioplegia). ATP decay and lactate increase were significant in group I and moderate to minimal in groups II and III after the same period of time. It is concluded that for aortic cross-clamp times up to 60 minutes, body hypothermia and injection cardioplegia using magnesium-aspartate-procaine at a myocardial temperature of 24 degrees C provide adequate protection of the myocardium. For ischemia times beyond 70 minutes, profound myocardial hypothermia below 20 degrees C is preferred.


Hemodynamic changes after experimental reduction of the left atrium. Two experimental models were studied to determine the hemodynamic consequences of atrial volume reduction as observed after operative correction of transposition of the great arteries. The volume of the left atrium (LA) was reduced either by inflation of an intracavitary balloon (group A) or by surgical intervention (group B) to 50--60% of the control values as determined by angiography. The angiographic data correlated well with the true volumes obtained by water displacement. This major reduction of LA volume caused small but constant hemodynamic changes. Although the LA stroke volume decreased by 50% and the LA/LV volume relation was reduced by 50% (from 0.42 to 0.21), there was only a slight increase of pulmonary artery pressure (7% in group A and 14% in group B) and a slight decrease in cardiac index (13% in group A and 10% in group B) and in left ventricular end-diastolic pressure (9% in group A and 11% in group B). The reduction of atrial volume results in only minor functional alteration of the intact heart.


Intraoperative electrophysiologic mapping during cardiac surgery. Intraoperative mapping is a method to document the surgical anatomy of cardiac tissues with electrophysiologic importance cartographically at time of surgery. The presented communication gives a survey of the present status of the technique of electrophysiologic mapping and its essential clinical applications. Special attention in this regard is directed to the intraoperative identification of the specialized AV conduction system in congenital cardiac malformations with unpredictable location of His bundle, to the detection of accessory AV bundles in patients with the Wolff-Parkinson-White syndrome and to the intraoperative morphological study of ventricular reentry tachycardias. Suitable technical equipment for "clinical" intraoperative electrophysiologic mapping is described in detail.


Open-heart surgery: somatic predictors of postoperative psychopathology. This study reports on some relationships between somatic conditions and postoperative psychopathological disturbances in 102 subjects from 20 to 65 years of age, undergoing open heart surgery. The overall incidence of postoperative psychiatric complications was 40%. Only two variables showed a significant correlation with the psychiatric criteria we used, independent of the different diagnoses: body weight and preoperative urea-N levels in serum. Some of the somatic predictors reported in the literature could be found to be specific for mitral or aortic valve disease. Predictors for psychiatric complications in patients with aortic valve replacement were: age, preoperative protein and urea-N levels in serum, and daytime sedation. The predictor in mitral valve replacement was the decrease in venous oxygenation (pulmonary artery) under physical strain.


Further evidence for independent segregation of the HLA system and a structural gene for the sixth component of complement (C6). Previous studies have shown conflicting results with respect to the relationship between C6 deficiency and the HLA system. The present investigation of two kinships, in which C6 deficiency was associated with the expression of an amorphic (or silent) C6 allele, has provided further evidence for the genetic independence of a structural C6 locus and the HLA system.


Distinctive features of cilia in metazoans and their significance for systematics. A comparative study of epidermal cilia in the Turbellaria and Nemertea has revealed features in these organelles that are specific to certain taxonomic groups. Turbellarians of the order Acoela, in particular, have a characteristic pattern of axonemal filament termination in the distal tips of their cilia and a characteristic ciliary rootlet system that is not seen in other turbellarian orders nor in other metazoans. Each epidermal cilium in acoels has a typical 9 + 2 axonemal pattern through the main part of its length, but near its distal tip there is an abrupt shelf-life narrowing at which filaments 4-7 terminate; filaments 1, 2, 8 and 9 continue into the thinner distal-most part of the shaft along with singlet microtubules from the axonemal center. The rootlet system in acoel cilia involves an interconnecting pattern with lateral connectives. The unique structure of these cilia has systematic and phylogenetic significance for the Acoela, and it is argued that ultrastructural characters in general, including characters of organelles, can be validly applied to the phylogeny and systematics of the Metazoa.


An ultrastructural study of morphogenesis of fibrogranular complex and centriole in ductuli efferentes of Chinese hamster. An ultrastructural study of ciliated epithelial cells in the ductuli efferentes of young and adult hamsters has revealed that these cells possess dense granules, dense granule clusters, dense bodies and fibrogranular complexes as reservoirs or precursors for ciliogenesis. The dense granules are first seen in the centrosomal region. Later, many dense granules and dense granule clusters appear in the apical portion of the epithelial cells where, subsequently, dense bodies are also found. Finally, the fibrogranular complexes are formed in adults. Morphological evidence strongly suggests that cilia are formed from diplosomal centrioles, de novo centrioles, dense body centrioles, and fibrogranular complex centrioles. Ciliogenesis begins in the fourth day after birth and increases rapidly in the fifth day. After the sixth day, cilia appear to be generated mostly from dense bodies and the total ciliogenesis activities gradually decrease as the animal ages.


Ultrastructural evidence for both autosynthetic and heterosynthetic yolk formation in the oocytes of an annelid (Phragmatopoma lapidosa: Polychaeta). The ovaries of the reef-building polychaete Phragmatopoma lapidosa are attached to the genital blood vessels on the caudal surface of the intersegmental septa of the abdominal segments. Oogenesis is not synchronized and vitellogenesis occurs before the oocytes are released from the ovary into the coelomic cavity. A portion of each developing oocyte rests on the basal lamina of the genital blood vessel while the remaining surface of the oocyte is covered by follicle cells. Two morphologically distinct types of yolk are formed during vitellogenesis: Type I, which may be formed autosynthetically by the conjoined efforts of the rough ER and Golgi systems; and Type II, which is presumably formed heterosynthetically from endocytosis of yolk precursors from the genital blood vessel. Heterosynthetic production of yolk in an annelid has not been reported previously.


Electron microscopic study of the cortical reaction of an ophiuroid echinoderm. The egg coats of an ophiuroid echinoderm (Ophiopholis aculeata) are described by electron microscopy before and after fertilization. The unfertilized egg is closely invested by a vitelline coat about 40 A thick, and the peripheral cytoplasm is crowded with cortical granules five or six deep. During the cortical reaction, which rapidly follows insemination, exocytosis of cortical granules takes place. Some of the cortical granule material is evidently added to the vitelline coat to form a composite structure, the fertilization envelope, which is made up of a 400 A thick middle layer separating inner and outer dense layers, each about 50 A thick. The elevation of the fertilization envelope from the egg surface creates a perivitelline space in which the hyaline layer soon forms. The hyaline layer is about 2 micron thick, finely granular, and apparently derived from cortical granule material. The extracellular layers of the early developmental stages of ophiuroids and echinoids are quite similar in comparison to those of asteroids; this finding helps support Hyman's argument that the ophiuroids are more closely related to the echinoids than to the asteroids.


The morphology and fine structure of the larval midgut of a moth (Manduca sexta) in relation to active ion transport. Light and electron microscopic examination of the midgut of Manduca sexta has shown that the organization of this tissue is more complex than was originally believed. The midgut can be divided into anterior, middle and posterior regions on the basis of the pattern of folding of the epithelial sheet, and variations in the structure of goblet and columnar cells which occur along its length. The columnar cells show gradual structural changes form the anterior to the posterior end of the midgut. For example, the microvilli in the anterior region form a dense, interconnecting network from which vesicles break off. This organization becomes less obvious through the middle region, until by the posterior region each microvillus is unconnected to adjacent microvilli along its entire length and vesicles are no longer produced. Two distinct types of goblet cells are found. In the anterior and middle regions the goblet cells have a large basally located cavity, but in the posterior region the cavity occupies only the apical half of the cell. In both cases the cavity is formed by invagination of the apical membrane, which is studded with small particles implicated in active ion transport. In the anterior and middle regions this membrane is closely associated with mitochondria, but not in the posterior region. The significance of the observed structural differences is discussed in relation to active ion transport.


Freeze-fracture and tracer studies on the intercellular junctions of insect rectal tissues. Both rectal pads of the cockroach and rectal papillae of the blowfly possess highly infolded lateral borders; these are associated by desmosomes and septate junctions that maintain the physical integrity of the cell layer at the luminal and basal intercellular regions. Adjacent cells are coupled by gap junctions that allow for cell-to-cell communication and which occur at intervals along the undulating lateral clefts. In rectal pads, occluding basal tight junctions are found as well as extensive scalariform junctions. The latter, like the stacked membrane infoldings of rectal papillae, exhibit intercellular columns and numerous intramembranous P face particles; these are undoubtedly involved in ion transport. In the inter-stack clefts of papillae, reticular septate junctions are encountered which, after freeze-fracture, possess a striking network of PF ridges and EF grooves that are discontinuous and not always complementary. These may serve to regulate the speed and extent of distension of the clefts during solute movement to allow for even and effective fluid flow in this transporting epithelium.


Developmental changes in Malpighian tubule cell structure. Structural changes which occur in the Malpighian tubule yellow region primary cells during larval-pupal-adult development of the skipper butterfly Calpodes ethlius are described. The developmental changes in cell structure are correlated with functional changes in fluid transport (Ryerse, 1978a) in a way which supports osmotic gradient models of fluid secretion. Larval tubules are specialized for fluid secretion with deep basal infolds and elongate mitochondria-containing apical microvilli which provide channels in which osmotic gradients could be set up. The Malpighian tubule cells are extensively remodelled at pupation when fluid transport is switched off, but they persist intact through metamorphosis. At this time, the basement membrane doubles in thickness, the mitochondria are retracted from the microvilli and are isolated for degradation in autophagic vacuoles, and both apical and basal plasma membranes are internalized via coated vesicles for degradation in multivesicular bodies, which results in the shortening of the microville and the disappearance of the basal infolds. Mitochondria are re-inserted into the microvilli, and the basal infolds re-form in pharate adult stage Malpighian tubules when fluid secretion resumes. Adult tubules are similar in general structure to larval tubules and contain mitochondria in the microvilli and basal infolds. However, they differ from larval tubules in that they are capable of very rapid fluid transport, have a reduced tubule diameter and tubule wall thickness, a much thicker basement membrane and peripherally associated tracheoles. Mineral concretions of calcium phosphate accumulate in larval tubules, persist through metamorphosis and decline in number in adults, suggesting they serve some anabolic role.


Chemically skinned mammalian skeletal muscle. I. The structure of skinned rabbit psoas. We studied the morphology of rabbit psoas muscle fixed at increasing intervals of time in a chemical skinning solution (Wood et al., 1975), or after skinning and storage for times up to 1 week. The storage solution, in which the chemically skinned muscled fibers were kept at -20 degrees C, had the same ionic composition as the skinning solution but was made with 50% (v/v) glycerol. Progressive structural changes occurred in fibers exposed to skinning solution. The structural changes were essentially complete after 24-48 hr in skinning solution and no further changes were detected in fibers stored for periods up to 1 week. Structural changes were: (i) holes or gaps in the plasma membrane; (ii) swelling of mitochondria and disorganization of their internal structure; (iii) slight swelling of the sarcoplasmic reticulum; (iv) disappearance of sarcoplasmic reticulum (SR) feet from triadic gaps. Other changes included loss of glycogen between fibrils and extraction of myoplasm, or the change of its staining properties. All architectural elements of the SR, except "feet", remained during skinning and storage, and the SR remained able to accumulate calcium. The morphology of the myofilaments during chemical skinning and during storage did not differ from control fibers. We conclude that chemical skinning alters the gross structure of the plasma membrane and mitochondria, but produces minimal changes in the sarcoplasmic reticulum and contractile proteins.


The palisade endings of cat extraocular muscles: a light and electron microscope study. The palisade endings (PEs), a particular type of nerve ending found only in extraocular muscles of mammals, have been studied using both silver-stained teased preparations and electron microscope techniques. They have been found, in act, in both the proximal and distal muscle insertions of the four recti and the two oblique mucles. PEs are exclusively associated with some of the mitochondria-poor, multiply-innervated muscle fibres present in the globar layer os these muscles, and consist of a multitude of terminal branches embracing the extremity of the muscle fibre and penetrating the infoldings formed by the muscle fibre at its tendinous attachment. The whole formation is surrounded by a thin capsule. These nerve endings present striking similarities to the developing Golgi tendon organ; the terminal branches lying among the collagen fibrils and occasionally making 'sensory-like' close contacts with the muscle fibre are disposed in such a way that they could easily have a sensory role. It was concluded that PEs present sufficient morphological evidence to be considered as sensory, encapsulated, myotendinous receptors, each related to a single multiply-innervated muscle fibre.