Introduction to the symposium on functional amblyopia: sensory or motor disorder? The theme of the symposium is identified by 2 questions: (1) is the mechanism that underlies functional amblyopia sensory or motor? and (2) How do sensory and motor factors contribute to the loss of acuity in amblyopic eyes? The answers to these questions as well as to several questions about clinical diagnosis and treatment of amblyopia are provided in the following 7 papers and panel discussion that comprise this symposium.


Eccentric fixation in amblyopia: is reduced foveal acuity the cause? The Worth-Chavasse theory of amblyopia is briefly reviewed with particular attention to Worth's explanation that eccentric fixation develops in an attempt by the amblyopic eye to fixate with an eccentric retinal locus having higher acuity than the fovea. Three experiments are reviewed; these show that of 8 eccentrically fixating amblyopic eyes tested, 7 had foveal acuity that was higher than or equal to the acuity at the eccentric fixation locus. A fourth study is reviewed, however, which reports that 24 of 25 eccentrically fixating amblyopic eyes had highest acuity at the eccentric retinal locus. With only slight reservations, the conclusion from the first 3 experiments that eccentric fixation does not occur to improve acuity appears justified, but the contrary results of the fourth study, in which fixation was not controlled, cannot easily be dismissed. The importance of performing an experiment that accurately measures acuity across the retinas of amblyopic eyes with careful control of fixation and target location is stressed.


Visual acuity at different retinal loci of eccentrically fixating functional amblyopes. Visual acuity was measured in eccentrically fixating amblyopic subjects to determine the contribution of sensory (inhibitory) and motor (retinal-locus) components of the acuity loss. A unique aspect of this research involved the subjects' use of auditory feedback to control their unsteady and eccentric fixation while responding to flashed (800 msec) or continuously presented targets at various eccentricities in the visual field. All 4 amblyopic eyes had maximum visual acuity at the fovea; from there, the acuity declined approximately symmetrically into the nasal and temporal periphery. Foveal acuity for these amblyopic eyes was depressed from the acuity at the fovea of the normal eye. We conclude that Worth's explanation of eccentric fixation (eccentric fixation develops in an attempt by the amblyopic eye to fixate with a peripheral retinal locus having higher acuity than the fovea) cannot apply to our amblyopes. The acuity losses exhibited by the amblyopic eyes studied have a sensory (inhibition) component and a motor (retinal-locus) component, the sensory component being greater for small degrees of eccentric fixation and the motor component being greater for large amounts of eccentric fixation.


A sensory mechanism for amblyopia: psychophysical studies. Psychophysical investigations of the effect of amblyopic process on the sustained and transient channels in the afferent visual pathway are reported. The experiments on photopic luminosity, increment-threshold spectral sensitivity, spatial contrast sensitivity, and reaction-time measures of suprathreshold grating detection provide converging evidence that in naturally occuring amblyopia of humans, the sustained neural channels are more severely affected than the transient channels. However, it appears that the sustained channels are not totally nonfunctional, but rather have a higher intensity requirement than normal.


Monocular performance of functional amblyopes: another look at the scotoma hypothesis. The traditional scotoma hypothesis for functional amblyopia is modified to state: whereas the central visual field of a normal visual system and that of an organic amblyope become increasingly scotomatous as light level is decreased from high to low photopic levels, the reverse is true for the central field of a functionally amblyopic visual system. An attempt is made to show how this hypothesis provides a unifying explanation for several seemingly different visual performances observed in functional amblyopes. The paper deals with (1) field inhomogeneities and threshold measures, and (2) threshold changes with light adaptation level. Implications of the modified scotoma hypothesis are discussed for (1) the neutral-density-filter test to distinguish functional from organic amblyopia, (2) the reduced CFF threshold for amblyopic eyes, (3) expectations of stereopsis for amblyopes, and (4) possible mechanisms for amblyopia.


A motor theory for monocular eccentric fixation of amblyopic eyes. A motor theory is proposed to explain monocular eccentric fixation of amblyopic eyes. Clinical observations that suggest the involvement of a motor anomaly related to strabismus are cited. The model proposes that potentiation (after discharge) of the agonist muscle in strabismus results in a nonregistered error of monocular fixation of the amblyopic eye. The position error goes undetected as a result of reduced sensitivity of the amblyopic eye. Evidence is cited for normal muscle potentiation in nonamblyopic eyes. A suggestion is made that amblyopia be considered both a sensory and a motor disorder. The sensory disorder is the reduced acuity at the fovea of the amblyopic eye. The motor disorder is muscle potentiation that causes the amblyopic eye to fixate with an eccentric retinal region that has lower acuity than the fovea. A distinction is made between motor anomalies that have a sensory basis, such as unsteady fixation in anisometropic amblyopia, and motor anomalies that have a motor basis, such as eccentric fixation in strabismic amblyopia.


Processing delays in amblyopic eyes: evidence from saccadic latencies. Saccadic latencies were measured in amblyopes with constant strabismus, amblyopes without strabismus, and intermittent strabismics with or without amblyopia. Subjects tracked a small spot of light, either monocularly or binocularly, which moved with random horizontal step displacements of 0.25--8.5 deg over the central field. Increased saccadic latencies were observed in the amblyopic eyes of 6 of 11 subjects, with or without strabismus; saccadic latencies were similar in each eye of 2 subjects having intermittent strabismus without amblyopia. Amblyopia was a necessary condition for increased saccadic latencies and not strabismus. Evidence for normal motor control of eye movements in amblyopic subjects is as follows: normal saccadic durations in the amblyopic eyes, normal saccadic-latency distribution curves for binocular tracking and monocular tracking with the nonamblyopic eyes, and synchronous movements of the 2 eyes. Our results are interpreted in terms of a processing delay in the sensory pathways leading from the central region of the amblyopic eye to the centers involved in saccadic initiation.


New method for determining the magnifying power of telescopes. A new method of measuring the power of optical telescopes is described. This method makes use of the vergence amplification that occurs when the light incident on the objective lens at a telescope is divergent or convergent. The relation between the vergence incident on the objective and vergence emergent from the eyepiece depends on the magnifying power and the length of the telescope. The method is most simple to apply to short-length, low-powered Galilean tesescopes, such as those used as low vision aids, in sports glasses, and in telescopic loupes. With such telescopes, holding a lens of known power against the objective and measuring the back vertex power of the lens-telescope combination using the lensometer and then measuring the telescope length allows the determination of the magnifying power of the telescope. The method can be adapted to determine the magnification rating of near-vision telescopic loupes.


Sighting dominance and binocular rivalry. Two experiments are reported that attempt to explore systematically the role of sighting dominance during binocular rivalry. Experiment 1 showed that the sighting eye tends to display longer total viewing time, and experiment 2 indicated that this asymmetry remained even when observers had increased experience with rivalrous stimulation. Additional analysis revealed that the average dominance period of the sighting eye was longer than that of the nonsighting eye, resulting in significant sequencing effects during the rivalry process.


Etiology of astigmatism.

Etiology of astigmatism. A large amount of evidence suggests that astigmatism is hereditary. Other evidence indicates that the prevalence of astigmatism varies widely between and within racial groups and that both the direction and the amount of astigmatism tend to vary as a function of age and in response to environmental influences.


Characterization of feline glomerulonephritis associated with viral-induced hematopoietic neoplasms. Light, electron, and immunofluorescence microscopy on tissues from 63 domestic cats revealed that glomerulonephritis occurred in almost one third of cats with hematopoietic neoplasms of the type linked with feline leukemia virus (FeLV). Glomerular lesions were of the immune complex type with subepithelial, subendothelial, and mesangial dense deposits and reticular aggregates, similar to the nephropathy associated with systemic lupus erythematosus in humans. Evidence that the glomerular lesions may be viral-induced raises the possibility of similar pathogenetic mechanisms in human disease.


Renal tubulointerstitial lesions in CBA/J mice. Renal tubulointerstitial lesions (RTL) were observed with high frequency in CBA/J mice more than 2 months old. RTL were characterized by interstitial infiltrates of lymphocytes and macrophages in the corticomedullary zone. Multinucleated structures sometimes resembling giant cells were present, and there was destruction of tubules and tubular basement membranes in areas of infiltration. Glomeruli appeared normal. RTL were first seen in  12 to 22 CBA/J mice 2.5 to 3 months old. By the age of 7 to 9 months, 35 to 45 mice were affected, and all 24 mice 12 months old or older had RTL. CBA/J mice had these unique renal lesions whether they were purchased and examined immediately, were obtained as weanlings andreared in our quarters or those of another institution, or were fourth generation descendants of purchased breeders. The propensity to develop RTL has been present in this strain for at least 2 years. RTL were not observed in C57BL/6J mice housed for 14 months with affected animals or in a survey of CBA/HUmc, C57BL/6J, A/J, BALB/cJ, or C3H/HeJ mice. Immunofluorescent examination of CBA/J kidneys appears to rule out antitubular basement membrane autoantibodies or immune complexes in the pathogenesis of RTL.


Sensitization to the generalized Shwartzman reaction by catechol-O-methyltransferase inhibitors. The generalized Shwartzman reaction (GSR) was produced by a single injection of endotoxin in male rats pretreated with catechol-o-methyltransferase (COMT) inhibitors (tropolone, pyrogallol). Such a result was not obtained with inhibitors (pargyline, phenelzine, isocarboxazide) of the monoamine oxidase (MAO). The inhibitors of the COMT were found to enhance the action of endotoxin on the coagulation system such as evidenced by the increased consumptions of Hageman factor, fibrinogen, and platelets. Tropolone-treated rabbits did not require exogenous stimulation of alpha-adrenergic receptor sites by norepinephrine to localize thrombi in the glomerular capillaries when Hageman factor was activated by ellagic acid and fibrinolysis inhibited by epsilon-amino-caproic acid. It is concluded that interference with the degradation of circulating catecholamines results in sensitization to the generalized Shwartzman reaction.


Anchoring fibrils. A new connective tissue structure in fibrotic lung disease. Electron microscopic studies of lung were made and compared in 17 patients with lung disease (10 with idiopathic pulmonary fibrosis, 3 with collagen--vascular diseases, 3 with sarcoidosis, and 1 with chronic eosinophilic pneumonia) and in 5 control patients. In control patients, the alveolar epithelial cells were normal, and no hemidesmosomes were present between the plasma membranes and the basal laminae. In comparison, cuboidal alveolar epithelial cells were present in 15 of the patients with fibrotic lung disease; in 9 of these the alveolar epithelial cells were multilayered. In 7 of the latter 9 patients (5 with idiopathic pulmonary fibrosis and 2 with collagen-vascular diseases), the basal laminae of the alveolar epithelial cells were attached to the plasma membranes by hemidesmosomes and to the underlying interstitial connective tissue by "anchoring fibrils." These fibrils measured from 4000 to 6000 A in length and from 200 to 600 A in width. One or both ends of the anchoring fibrils inserted into thebasal lamina, often forming arcs through which collagen fibrils and connective tissue microfibrils penetrated. Anchoring fibrils showed a complex pattern of transverse banding, which differed from that of collagen and appeared to be symmetric about the center of the fibril. These anchoring fibrils, which resemble those in normal skin and other tissues, were not found in lungs of control patients. In addition, there was a significant correlation between the severity of the pulmonary fibrosis and the presence of anchoring fibrils. These observations suggest that in severe fibrotic lung disease, anchoring fibrils reinforce the attachment of the basal lamina of multilayered alveolar epithelial cells to interstitial connective tissue.


Ultrastructure of the myocardium after pulmonary embolism. A study in the rat. The purpose of this study was to find out whether acute massive pulmonary embolism can produce myocardial changes visible by light and electron microscopy. Ww therefore produced pulmonary embolism in rats using plastic microspheres (diameter, 15 +/- 5 mu). Two experimental protocols were used: lethal embolism, with a dose of microspheres known to kill in 3 to 15 hours (these rats were killed after 1 hour), and sublethal embolism, with a dose compatible with 100% survival (these rats were killed after 24 hours). In both groups, the left ventricle was normal. The right ventricle showed two tyes of changes: a) A distinctive lesion of the myocytes, more diffuse after lethal enbolism and different from the "zonal lesion" of shock. It consisted primarily in a localized shredding of the myofibrillar system; hence, the name shredding is  proposed. Earlier stages of this lesion were represented by focal dissolution of the Z line (Z lysis). The pathogenesis of these lesions appeared to be primarily mechanical. b) Necrosis was already apparent at 1 hour and was more extensive after 24 hours. The pathogensis of the necrotic lesions is best explained by a temporary ischemia followed by delayed reflow; a possible potentiating role of endogenous catecholamines cannot be excluded. Most capilaries in the necrotic foci remained functional; this explains the rapid rate of the healing process of such lesions. A comparison is drawn between the observed foci of necrosis and the human myocardial lesions knowns as "miliary infarcts" and "myocytolysis." It is proposed that a factor common to all three is the preservation of the microcirculatory vessels and that our experimental model helps illuminate the pathogenesis of the human lesions. It is concluded that the right ventricle of acute cor pulmonale may develop cellular changes with a complex pathologenesis (mechanical, ischemic, and possibly hormonal). The nature of the changes found in our model could represent the morphologic substrate of right-sided failure; it can be correlated with the electrocardiographic abnormalities found in the comparable human condition.


Ultrastructural evaluation of the effects of 1,25-dihydroxyvitamin D3 on bone of thyroparathyroidectomized rats fed a low-calcium diet. Thyroparathyroidectomized rats fed a low-calcium-normal-phosphorus diet were administered 1 or 5 units of 1,25-dihydroxyvitamin D3-(1,25-[OH]2D3) or placebo daily for 7 days. 1,25-(OH)2D3 elevated serum and urine calcium and decreased serum phosphorus. Rats given 1 unit of 1,25-(OH)2D3 had increased numbers of osteoclasts in metaphyseal trabeculae, Ultrastructurally, osteoclasts, osteoblasts, and osteocytes in rats given 1 unit of 1,25-(OH)2D3, were similar to those in rats given placebo. In rats given 5 units of 1,25-(OH)2D3, osteoclasis was markedly increased. Osteoblasts were more numerous and interpreted to be active in matrix production and mineralization. Lamellated electron-dense bodies were observed adjacent to the plasma membranes of less active osteoblasts and were interpreted to be modified matrix. Most osteocytes in rats given 5 units of 1,25-(OH)2D3 were indistinguishable from osteocytes in rats given placebo. However,the pericellular space of some osteocytes in rats given 5 units of 1,25-(OH)2D3 contained electron-dense granular deposits that were interpreted to be calcium phosphate. It is concluded that 1,25-(OH)2D3 is able to significantly elevate serum calcium independent of dietary calcium, parathyroid hormone, and calcitonin primarily by increasing ostoeclasis with minimal dependence on osteocytic osteolysis.


Dose-dependent inhibition of experimental arterial thrombosis by carbenicillin and ticarcillin. An experimental model of canine arterial thrombosis was used to study by prophylactic antithrombotic effectiveness of carbenicillin and ticarcillin, two semisynthetic penicillins which have been shown to inhibit platelet function in vivo. Isolated peripheral arterial segments were injected with pronase and biopsied at 24 hours. In untreated dogs, 89% of injected segments totally occluded with thrombus. Prophylactic treatment for 3 to 7 days with carbenicillin or ticarcillin in low doses (250 mg/kg/day) or high doses 750 mg/kg/day) significantly decreased the incidence of total occlusion to 53% and 6%, respectively. The dose-dependent inhibition of arterial thrombosis correlated with dose-dependent inhibition of platelet function. Prophylactic treatment with aspirin in low doses (650 mg/day) or high doses (2600 mg/day) did not significantly decrease the incidence of total occlusion in this model. Carbenicillin and ticarcillin are effective experimental antithrombotic agents.


Some effects of bicultural and monocultural school environments on personality development. Preadolescent girls in a bicultural school, compared with those in a monocultural school, showed more heterocultural peer-group organization, better self-image, and greater acceptance of an unknown cultural group. These differences were not found among younger (latency-age) children in the two schools. No significant differences were found in role-taking ability between girls in the two schools, suggesting that the bicultural school environment contributes to the difference in the other personality dimensions studied.


Methods for studying sensitive family topics. Researchers on sensitive topics in family relations face a number of obstacles, due to the private nature of the family and to ethical constraints on the study of humans. Difficulties in locating subjects, engaging their cooperation, and obtaining valid and reliable data are discussed, and methods are proposed for pursuing research on these important but frequently taboo topics.


The behavioral symptoms of hyperkinetic children who successfully responded to stimulant drug treatment. Hyperkinetic children who successfully responded to drug treatment were compared with controls on a series of objective measures of activity and attentional problems. Although group differences were found on most measures, there were no indications that these children were more homogeneous in their behavioral symptoms than the hyperkinetic population in general.


Hyperactives as young adults: school, employer, and self-rating scales obtained during ten-year follow-up evaluation. A ten-year prospective follow-up of hyperactive adolescents and young adults indicates that they are rated as markedly inferior to normal controls by teachers but not by employers. On self-rating scales, they view themselves as inferior to controls on a personality test, but no different than controls on a psychopathology scale.


The role of goal attainment scaling in evaluating family therapy outcome. The role of an individualized goal attainment procedure as an outcome measure for brief family therapy is described. Establishment of a scale and assessment of goal attainment at six-month follow-up are reported in a study of some 270 families. Results support the procedure as being a reliable and valid means of examining the outcome status of treated families.


Attitudes towards symptoms and services in the ethnic family and neighborhood. Research in Baltimore's Italian and Polish neighborhoods suggest that the extended family is seen as the front-line resource for intensive advice on emotional problems. Mental health specialists frequently are not preceived as the appropriate agents for meeting problems that are beyond the expertise of the family and local community. Implications for community mental health are examined.


Battered wives: barriers to identification and treatment. As it becomes increasingly evident that wife-beating is widespread in the United States, the need for adequate professional assitance to the victims becomes more pressing. This study, reflecting the author's experiences in offering psychiatric counseling to battered wives, outlines the difficulties in reaching out to this population and offers suggestions for treatment approaches.


Adolescent health services and contraceptive use. A pilot study of a health services program for never-pregnant high-school students, which stresses development of incentives for personal involvement in their own health care, reports a low incidence of unintended pregnancy among girls who requested contraceptives. The social and emotional characteristics of those who continued contraceptive use are compared with the small group who had uninteneded pregnancies.


A group approach to the depressed adolescent girl in foster care. Depression reactive to severe early loss and current environmental pressure is a salient common characteristic of many adolescent girls in foster care. This paper describes work with developmentally-oriented mutual aid groups focused on depression and coping, which have been successful in promoting ego strengths and growth in this population.


Late-life paranoid states: assessment and treatment. Paranoid states are a frequent and often disturbing disorder in the elderly, but treatment potentials are often overlooked. Etiological factors are reviewed, with attention to differential diagnosis. Treatment issues, including the role of a therapeutic relationship, the impact on the person's social network and prognosis, are discussed.


A paradigm for the classification of emotional crises: implications for crisis intervention. A model for the classification of six general types of crises frequently encountered in crisis clinics is presented. Defining characteristics, intervention strategy, and a case example are considered for each type of crisis. The model is proposed for teaching crisis therapy and enhancing the effectiveness of crisis intervention in clinical contexts.


The vermiculate surface pattern of brow ridges in Neandertal and modern crania. A convoluted surface pattern of ridges and grooves characterizes the frontal torus in adult Neandertal fossils. Modern human skulls rarely have the pattern well developed. It is not observed in postcranial bones, nor in skulls of Neandertal children. This vermiculate bone is resistant to oriented cracking from weathering or fractures. Structural characteristics of the bone give evidence on the problem of the function of hominid brow ridges.


Univariate and multivariate methods for sexing the sacrum. Metric data on 200 sacra of known sex, age and race are analyzed to determine the usefulness of conventional observations for determining sex in this bone. Results of the univariate analysis show that significant sex differences in the sacrum involve primarily the top portion of the bone for both whites and blacks. However, measurements of curvature are important sex differences in the sample of blacks. A new index relating the S1 body to sacral breadth is proposed as more useful in classifying the bones by sex than indices involving other measurements. Discriminant analysis shows that the sample of whites can be analyzed significantly better by this method than by using an index. The choice of univariate or multivariate method must depend on the condition of the bone, and will be influenced to some extent by the race from which the sample is drawn.


Distribution of albumin variants Naskapi amd Mexico among Aleuts, Frobisher Bay Eskimos, and Micmac, Naskapi, Mohawk, Omaha, and Apache Indians. In order to help define the boundaries of the distribution of the albumin variants Naskapi and Mexico which are polymorphic among several American Indian groups, we examined sera from Micmac, Mohawk, Northwest River Naskapi, Omaha and Apache Indians, and from Aleuts and Eskimos. Sera from a total of 1,524 individuals were examined. Using a cellulose acetate membrane electrophoretic system with Tris-Citric acid at pH 5.4 we were able to distinguish normal albumin and both variants in the same run. Naskapi and Mexico variants were absent from Aleut, Eskimo, Micmac, Mohawk and Omaha samples. The albumin Naskapi variant was present in an allele frequency of 0.03 in the Naskapi Indian sample. Albumin variants Naskapi and Mexico were found in the Apache sample at frequencies of 0.016 and 0.037, respectively. This report supersedes that previously published by Schell and Agarwal ('76). Generally, within an area there is a correspondence between changes in the frequency of albumin variants and changes in the ethnic background and history of the area's populations. At the same time, when viewing widely separated areas, relationships between distant groups based on linguistic and cultural similarities are paralleled on a biologic level by the distribution of normal albumin and variant albumins.


Statistical power in physical anthropology: a technical report. A statistical power analysis of The American Journal of Physical Anthropology (Volume 44, 1976) was conducted. Twenty-five articles, which included 3,304 major significance tests, constituted the final sample. Resultant power estimates of 0.38, 0.62, and 0.81, corresponding to small, medium, and large population effects respectively, were obtained. Although the medium effect size estimate falls short of the recommended 0.80 level, the statistical power of physical anthropological research fares well relative to several of the social scientific fields of inquiry.


ABO blood groups in Chilean and Peruvian mummies. II. Results of agglutination-inhibition technique. ABO blood groups of Peruvian and Chilean mummies were determined with the agglutination-inhibition method. In Peru all ABO blood groups were found in the period from 3000 B.C. to 1400 A.D.; from this period to 1650 only A and O were seen. In Chile no B or AB was noted either in pre-Columbian or Colonial mummies. This confirms the archeological concept that the Chilean Indian was culturally as well as genetically different from the Peruvian Indian. Further studies using other genetic markers are in order, as well as changing certain preconceived notions on blood groups of American Indians.


Red cell glucose-6-phosphate dehydrogenase deficiency among Andhras. Sixty-eight Andhra males and 45 Andhra females from Visakhapatnam town of Andhra Pradesh, India have been investigated for G-6-PD deficiency. The GdB- gene has a frequency of 4.41% among males. No G-6-PH deficient females were detected. The present data have been compared with the available tribal and non-tribal data from Andhra Pradesh. It is observed that the present sample, though non-tribal in nature, presents a relatively considerable frequency of the GdB- gene.


The effects of stress on cortical bone thickness in rodents. The right and left femora of three groups of rodents, cold stressed, noise stressed, and heat stressed, were sectioned transversely at the most inferior point of the third trochanter. Cortical bone thickness of the proximal section for all three groups was determined by measuring an enlargement obtained with a Wild stereo microscope with a camera lucida drawing attachment. Cold stressed animals were found to have significantly thinner cortical bone than did controls, noise stressed animals did not differ from controls, and heat stressed animals had thinner cortical bone than did controls. It is concluded that stress may be responsible for the thinner cortex of cold and heat stressed animals, but that other factors may be at work and that it is not possible to tell whether different types of stress act through the same or through different mechanisms.


Interobserver error in human skin colorimetry. Twenty light-skinned adults were measured at the upper inner arm site using two commonly used reflectance spectrophotometers. Each subject was measured by each of three investigators to assess the influence of interobserver error on the reflectance readings. A repeated measures design analysis of variance showed no significant variance component due to observers.


Empirical comparison of distance equations using discrete traits. The use of the Grewal-Smith statistic in measuring biological distance among skeletal population samples has been questioned since it was first applied to human populations. Recently, in an attempt to stabilize the variance of the Grewal-Smith statistic for use with non-metric analysis, Sjøhivold ('73) and Green and Suchey ('76) have introduced corrections and alternative transformations which may enhance the meaning of biological distance among population samples. Their recommendations improve the statistics for specific variable ranges; i.e., small sample size and low trait frequencies. Thirteen equations representing Grewal-Smith, Freeman-Tukey, Anscombe, and Bartlett transformations and/or corrections, were compared using rank order correlation statistics on actual biological distances generated by real population data as presented in existing literature. Results from testing these actual distance models show little variation between equations based on the populational data sets used. Based on these findings, the distance model resulting from the Grewal-Smith statistic is not inferior to the more sophisticated models, although the latter may be superior allowing specific improvements for small sample size and/or low trait frequencies.


Electromyography of pongid shoulder muscles III. Quadrupedal positional behavior. Electromyographic (EMG) recordings were taken from 14 shoulder muscles (or major parts of them) in a gorilla, a chimpanzee and an orangutan as they stood quadrupedally and tripedally, descended from elevated substrates, crutch-walked, and progressed quadrupedally on inclined and level substrates. In the African apes, low potentials commonly (but not always) occurred in the sternocostal pectoralis major, anterior deltoid, supraspinatus and subscapularis muscles during quadrupedal stance. The quadrupedal orangutan always exhibited low potentials in the pectoralis major muscle and EMG activity commonly occurred in her supraspinatus and subscapularis muscles. Quiescent tripedal stances were not accompanied by striking changes in EMG patterns from those which characterized quadrupedal stances. Per contra, eccentric loadings of the forelimb during descents from elevated substrates generally recruited notable EMG activity in the deltoid, supraspinatus and, to a lesser extent, infraspinatus muscles of the three pongid apes. The pectoralis major and caudal serratus anterior muscles were much more active in Pongo and Pan during these descents. Supportive segments of quadrupedal locomotive cycles were generally accompanied by EMG activity in the pectoralis major, intermediate and posterior deltoid and supraspinatus muscles. The intermediate and posterior deltoid muscles were characteristically active during pre-release of the hand and early swing phase. The cranial trapezius and supraspinatus muscles also may act during early swing phase. We conclude that the pectoralis major and perhaps the supraspinatus and subscapularis might serve regularly as postural muscles during static terrestrial quadrupedalism in pongid apes. The lack of dramatic differences between the EMG patterns exhibited during fist-walking versus knuckle-walking indicates that an evolutionary transformation from a shoulder complex like that of Pongo to ones like Pan or vice versa need not entail major changes in myological features.


A re-examination of parturition scars on the human female pelvis. Pits, cavities and depressions located on the dorsal surface of the pubic symphysis of females have been attributed to the trauma of parturition. Earlier research based on human skeletal remains provides inadequate information on the individual's obstetrical history. The 68 female pubic bones that were studied had comprehensive medical records indicating whether or not each female had given birth. Fourteen and one-half percent of the females who had not given birth exhibited trace to small scarring of the pubic symphysis and 23.4% of the females who had not given birth exhibited medium to large scarring. It is suggested that bony changes previously used as an indicator of child bearing must be re-examined in light of the fact that "birth scarring" has been found in women known not to have had children.


Chemical energetics of single isometric tetani in mammalian smooth muscle. A rabbit taenia coli preparation has been used to study the chemical energetics of smooth muscle contraction. Under the experimental conditions, the muscle had no spontaneous mechanical activity, but could be fully activated with the use of electrical field stimulation. ATP resynthesis from glycolysis and respiration was stopped with a procedure that involved treatment with metabolic inhibitors at 5 degrees C followed by rewarming to 18 degrees C. This procedure did not alter the high-energy phosphate contents of mechanical responses of the muscle. Use of this preparation to determine ATP and phosphorylcreatine changes during isometric tetani at 18 degrees C and a length of 86% LO showed that there was net ATP breakdown initially with no significant phosphorylcreatine splitting. This was followed by an increase in the rate of phosphorylcreatine splitting with net ATP synthesis. The average rate of total high-energy phosphate utilization was about 0.01 mumol/g.s for up to 60 s or about 150 times less than that of frog sartorius at the same temperature.


Contribution of sodium pump to resting potential of squid giant axon. The effect of the cardiotonic aglycone, strophanthidin, on sodium and potassium efflux, membrane potential, membrane conductance, potassium permeability, and the shape of the action potential of the giant axon of the squid, Loligo pealei, was examined. Strophanthidin depolarized the membrane to an extent determined by the intracellular sodium concentration, except in axons pretreated with cyanide, in which the effect is abolished. Cyanide itself hyperpolarized the axon membrane. Axons treated with strophanthidin appear to be better potassium electrodes, but this observation is fully accounted for by the stimulating effect of [K]o on an electrogenic sodium pump. The increase in potassium efflux produced by strophanthidin is also well accounted for by the observed membrane depolarization and the known dependence of potassium permeability on membrane potential (e-fold increase in efflux per 6.4 mV depolarization). Strophanthidin has no demonstrable effect on membrane conductance apart from that due to the observed depolarization. These findings support the view that cardiotonic steroids, at least in nerve, are specific inhibitors of the sodium pump, devoid of effects on permeability that might interfere with the study of electrogenic pumping. The alteration in the shape of the action potential after exposure to strophanthidin (deepening of the "underswing") suggests that the strophanthidin-induced membrane depolarization results from the inhibition of a true electrogenic pump, and not from ion redistributions in the vicinity of the membrane.


Electric current generated by squid giant axon sodium pump: external K and internal ADP effects. The operation of the sodium pump of giant axons of the squid, Loligo pealei, has been studied simultaneously in two independent ways: 1) by measuring sodium efflux with 22Na, and 2) by calculating the transmembrane current generated by the pump from measurements of membrane resistance and digitalis-sensitive membrane potential. In normal, untreated axons, the effect of increasing the external potassium concentration on both sodium efflux and pump current is similar, which suggests that Na:K pump stoichiometry remains relatively constant in the range of 0-20 mM external K. The data are compatible with a 3:2 Na:K ratio. In axons whose intracellular ADP level has been elevated by injection of L-arginine, a large, electrically silent, cardiotonic steroid-sensitive sodium efflux takes place in the absence of external potassium; this suggests that pump-mediated Na:Na exchange is 1:1 or electroneutral. Finally, elevation of external potassium levels causes the appearance, in high-ADP axons, of electrogenic pumping, with little effect on sodium efflux; hence, in contrast to what is seen in normal (low-ADP) axons, the charge translocated, per sodium ion extruded, increases sharply with increasing extracellular potassium levels.


An inexpensive, high output voltage, voltage clamp for epithelial membranes. A circuit is described that can produce a high output voltage to automatically short-circuit an epithelial tissue mounted in an Ussing chamber. Because of its high output voltage it can short-circuit preparations requiring over 500 muA even in conjunction with high-resistance agar bridges. The circuit, which is easy to build, uses an inexpensive, low-voltage, integrated circuit operational amplifier, which is electrically isolated from the high-voltage part of the circuit by an optical isolator. The device can also be modified for use as a high impedance preamplifier for monitoring the spontaneous membrane potential.


Flow and potentials during perfusion of lacrimal gland with electrolyte solutions. Resting membrane potentials, acetylcholine (ACh)-induced change in membrane potentials of lacrimal gland cells, and ACh-induced flow from the excretory duct of the lacrimal gland were recorded during close intra-arterial perfusion of various electrolyte solutions. Resting membrane potentials were unchanged during perfusion with Na+-free, Cl--free, K+-free, and K+-rich solutions. Regardless of the composition of the perfusion solution, ACh induced hyperpolarization of the majority of cells but it also induced depolarization or biphasic potential or no change in potential in a significant number of cells. When the gland was perfused with a Na+-free or a Cl--free solution, the magnitude of the ACh-induced hyperpolarization was not changed but ACh-induced flow was markedly decreased. We conclude that the process(es) responsible for the ACh-induced change in potential may differ from those responsible for the ACh-induced flow and caution should be used when drawing conclusions about mechanisms of secretion solely from analysis of electrophysiological data.


Bicarbonate secretion and solute absorption in forestomach of the llama. Bicarbonate appearance in the lumen and its relationship to solute absorption were studied in a Pavlov pouch in the cardiac region of the first compartment of the llama forestomach. HCO3- appearance showed no diurnal variation. HCO3- accumulation was highly dependent on the pH of the solution used. The HCO3- ion probably is formed from CO2 diffusing into the lumen from the serosal side, as a result of cell metabolism and of OH- ions. HCO3- accumulation was closely related to volatile fatty acid (VFA) absorption. The ratio of HCO3- appearance to VFA absorption depended on the pH of the solution. At a pH of 6.6, about 0.1 mol HCO3- and, at a pH of 7.8, 0.9 mol HCO3- appeared per mole absorbed VFA, indicating that at slightly alkaline pH nearly all H+ ions required for the nonionic absorption of VFA appeared to be delivered from the dissociation of H2CO3. Bicarbonate gain and VFA absorption were increased when animals were not fed for 48 h. Sodium absorption was related to VFA as well as water absorption.


Transamination of branched-chain keto acids by isolated perfused rat kidney. Isolated rat kidney perfused without substrate released serine, glycine, and taurine, and substantially smaller amounts of other amino acids. When branched-chain keto acids were added, the corresponding amino acids were released at rates amounting to 15-25% of keto acid disappearance. Perfusion with 2 mM alpha-keto-isovalerate or alpha-keto-beta-methylvalerate caused an increased glucose release amounting to 18-23% of keto acid disappearance. The activity of branched-chain amino acid transferase (BATase) was significantly stimulated by perfusion with the analogue of leucine, but not by perfusion with alpha-ketoglutarate, the analogues of valine or isoleucine, or with leucine itself. These findings document that the kidney converts branched-chain keto acids in part to the corresponding amino acids and suggest that the keto analogue of leucine may be involved in the control of renal BATase activity, thereby indirectly regulating the metabolism of branched-chain amino acids.


Responses of feline esophagus to cervical vagal stimulation. We used an in vivo feline model to study striated and smooth-muscle esophageal responses to cervical vagal stimulation (VS). Circular esophageal contractions were measured by intraluminal pressure sensors and longitudinal contractions by a force transducer. Responses to VS were recorded before and after giving succinylcholine, atropine, or both. Circular contractions characteristic of striated and smooth muscle were recorded from the mid- and distal esophagus, respectively. With increases in VS frequency, the striated muscle showed rapid, repetitive twitches progressing to tetany. These fast contractions had a square-wave configuration at VS greater than or equal to 10 Hz and were abolished by succinylcholine. In contrast, the slow-twitch circular responses of smooth muscle showed no repetitive twitches and had a bell-shaped configuration. Two types of circular smooth-muscle contractions were observed: 1) A wave "on contractions" occurred 0.5-1.0 s after VS onset, regardless of stimulus length, and 2) infrequent B wave "off contractions" occurred only after stimulus cessation. The longitudinal esophageal contractions had a compound wave form with both striated and smooth-muscle components. Atropine abolished the slow component of the longitudinal contraction, the circular A wave, and peristalsis in the distal esophagus. We conclude that cholinergic motor neurons are an important pathway for eliciting peristalsis in feline esophageal smooth muscle.


Parallel pathways for ion transport across rat gastric mucosa: effect of ethanol. Transmural fluxes of 22Na or 36Cl across the isolated rat gastric mucosa were measured simultaneously with [3H]mannitol in an attempt to separate transmural ionic movement into cellular and noncellular components. The relationships between mannitol flux and the fluxes of Na and Cl are characteristic of simple diffusion, suggesting that mannitol traverses the isolated epithelium largely via noncellular pathways. The total tissue conductance can be described as the sum of two components, one of which is highly correlated with the transmural mannitol flux and presumably represents the conductance of a noncellular leak path. The cellular components of the mucosa-to-serosa Na flux and of both Cl fluxes are highly correlated with the short-circuit current. Exposure of the mucosal surface of the epithelium to 4% ethanol reduces the short-circuit current and increases the electrical conductance. Ethanol inhibits the active transport of Na and Cl and increases the apparent permeability of noncellular pathways for transmural ionic diffusion.


Skeletal mass in postmenopausal women.

Skeletal mass in postmenopausal women. The techniques of photon absorptiometry of the radius and total body neutron activation analysis were used for the determination of bone mineral content and total body calcium, respectively. The subjects consisted of 71 normal women who were 1-5 yr postmenopausal and 44 osteoporotic women who had crush fractures of the dorsal spine. Both bone mineral content and total body calcium were corrected for age and body size by using the ratio of observed values to those predicted from previously derived equations. Discrimant analysis involving both osteoporotic and normal postmenopausal women resulted in the successful assignment of 81% of the 115 subjects to their correct group. Statistical analyses of the distribution of the bone mass of the postmenopausal women yielded no evidence to support the hypothesis that a subgroup exists with bone mass levels markedly different from the remainder of the women.


Hepatic insulin and glucagon extraction after their augmented secretion in dogs. Effects of intravenous arginine and cholecystokinin-pancreozymin (CCK-PZ) infusion on hepatic extraction of insulin (EI) and glucagon (EGG) and also on hepatic glucose output (HGO) were studied in anesthetized dogs. Because insulin and glucagon exert antagonistic effects on HGO, insulin:glucagon (I/GG) molar ratios were determined in the portal vein and also in peripheral vessels. During the arginine-CCK-PZ infusion the amount of insulin and glucagon coming to the liver increased 12- and 15-fold, respectively. In contrast EI decreased significantly from a control value of 62 +/- 6% to a nadir of 22 +/- 13%. EGG (control value 19 +/- 9%), however, was unaffected by arginine-CCK-PZ. The absence of any alteration in EGG cannot be attributed to the molecular heterogeneity of the immunoreactive glucagon. HGO increased fourfold in response to the pancreatic stimulation, whereas portal I/GG decreased significantly from 8.2 +/- 0.9 to 5.0 +/- 0.7. The concurrent femoral arterial I/GG (control 3.7 +/- 1.0) and mesenteric venous I/GG (control 2.1 +/- 0.5) increased significantly. These observations indicate that portal, but not peripheral, I/GG measurements reflect hepatic events in anesthetized dogs, probably because of the different extraction patterns for insulin and glucagon.


Mobilization of ascites in cirrhotic dogs following furosemide or mannitol diuresis. Mobilization of ascites was studied in 20 anesthetized dogs with experimental cirrhosis following a mannitol- or furosemide-induced diuresis. Observations were made at 2 h following the drug, at which time the diuresis was invariably completed, and repeated at 4 h following a 2-h recovery period, during which the ureters were clamped to prevent further urinary losses. In the furosemide group the mean urinary loss was 459 +/- 6 ml and was accompanied by a decline in central venous pressure and hemoconcentration. At 2 h plasma volume had declined by 14% from control values, but at 4 h plasma replenishment was 99% complete. At this time ascites volume had decreased by 467 ml, acting as the major source for vascular replenishment. In the mannitol group, the average urinary loss was 190 +/- 10 ml and was accompanied by maintenance of venous pressure, lack of hemoconcentration, and hyponatremia. At 2 h plasma volume had expanded from control values by 22%, but at 4 h vascular replenishment was only 78% complete. The average ascites volume had decreased by only 55% of the diuretic loss, and was mobilized by a complex sequence of events involving movement of intracellular water.


Urinary zinc excretion following infusions of zinc sulfate, cysteine, histidine, or glycine. Zinc sulfate (40 mg elemental zinc) or one of three amino acids (5 or 10 g cysteine, 10 g histidine, or 10 g glycine) was infused into anesthetized dogs over a 60-min period. Plasma concentrations and urine excretions of zinc and five other cations, and glomerular filtration rates were determined before, during, and after these infusions. Infusions of zinc sufficient to produce a 20-fold increase in total plasma zinc concentrations had little effect on urinary zinc excretions (threefold increase) or plasma ultrafilterable zinc concentrations. Ten grams of cysteine urinary zinc excretions more than 100-fold, 5 g of cysteine increased zinc excretions more than 30-fold, 10 g of histidine increased zinc excretions sixfold, and 10 g of glycine had no effect. Cysteine infusions appeared to produce a net tubular secretion of zinc. Only histidine appeared to increase serum ultrafilterable zinc concentrations significantly. It would appear that plasma and urine concentrations of certain amino acids, specifically cysteine and histidine, along with polypeptides and other metabolites containing these amino acids, may be major determinants of urinary zinc excretion.


Inhibition of renin release from rat kidney slices by the angiotensins. The mechanism and structural basis of the inhibition of renin release by angiotensin II (AII) were studied in rat kidney slices. Renin release was inhibited by AII and the (2-8), (3-8), (4-8), and (5-8) peptides of AII (5 X 10(-5) M). These constituent peptides of AII which share a common carboxyl terminus inhibited renin release with a sharp decrease in potency when the amino-terminal amino acid was removed. Saralasin attenuated the inhibition of renin release induced by equimolar concentrations of AII. Dose-response curves for AII and the (2-8) peptide [angiotensin III (AIII)] indicate that AII is a more potent inhibitor of renin release than is AIII. Depletion of renal norepinephrine by reserpine (10 mg/kg, i.p.) or pretreatment of slices with papaverine (1 X 10(-4) M) did not block the action of AII. The data give evidence for a direct action of AII on the juxtaglomerular cells independent of an interaction with either the sympathetic nervous system or the arteriolar baroreceptor and suggest that the intrarenal receptors that mediate AII-induced inhibition of renin release differ from AII receptors in the adrenal cortex.


Reentrant excitation as a cause of cardiac arrhythmias. Mechanisms that cause reentry were defined in rings of tissue cut from jellyfish as early as 1906 by Mayer. The concepts were developed by Mines and Garrey during the next 10 years. Lewis then tried to demonstrate that reentry caused atrial flutter. Lewis, Garrey, and later Moe also proposed that atrial fibrillation was caused by reentry. Rosenblueth provided additional experimental evidence that reentry could cause atrial arrhythmias after crushing the intercaval bridge of atrial muscle. Recent studies by Allessie using microelectrodes have provided detailed evidence for reentry in atrial tissue. Mines in 1913 also proposed that reentry could occur in the AV node. Scherf then introduced the concept of functional longitudinal dissociation as a cause of return extrasystoles and this was later shown to happen in the node by Moe and his colleagues. Reentry can also occur between atria and ventricles utilizing accessory connecting pathways. Schmitt and Erlanger in 1913 were the first to do experiments which indicated that reentry can also occur in the ventricles. Subsequently it was shown that reentry can occur in Purkinje fiber bundles. Reentry in ventricular muscle may also cause some of the arrhythmias that occur after myocardial infarction.


Lungs from chronically hypoxic rats have decreased pressor response to acute hypoxia. We measured pressor responses in blood-perfused lungs from rats kept at low altitude (LA, 1,520 m) and from rats exposed to simulated high altitude (HA, 4-6 wk at 4,270 m) to see if lungs from chronically hypoxic rats were hyper- or hyporeactive to acute airway hypoxia. HA lungs had bigger pressor responses to intra-arterial angiotensin II, prostaglandin F2alpha, and norepinephrine, but smaller responses to airway hypoxia than did LA lungs. The dose-response curve to hypoxia in HA lungs was shifted to the right of that in LA lungs. Thus, HA lungs were hyperreactive to intra-arterial agonists, but were hyporeactive to acute airway hypoxia. In contrast, additional experiments with rats that had been exposed to HA for 5 wk and then returned to LA for 3 days showed that the lungs from such post-HA rats were hyperreactive to acute airway hypoxia. The decreased pressor responsiveness to acute hypoxia in lungs from chronically hypoxic rats could have been due to an increased activity of some endogenous vasodilator or to some abnormality in the mechanism that couples hypoxia to contraction of the vascular smooth muscle.


Human platelet chemotaxis: requirement for plasma factor(s) and the role of collagen. Platelets are actively mobile in plasma in vitro and, in addition, they migrate specifically and directionally toward added intact collagen (chemotaxis). Native human, bovine, and equine collagen, suspended in plasma, induce a chemotactic response in human platelets. However, heat-denatured and dinitrofluorobenzene-treated collagen fail to attract platelets. Platelets migrate directionally and specifically to intact native collagen incubated in plasma over a large distance (6 mm) in a very short time (total 15 min), as observed in a newly designed micromaze apparatus. Platelets obtained from donors deficient in plasma factors XII, IX, and VIII showed normal migration and chemotaxis in normal plasma and in their respective factor-deficient plasmas. Although nondirectional movement (mobility) was normal, platelets from a donor deficient in factor XI did not exhibit chemotaxis toward collagen in either factor XI-deficient plasma or in normal plasma. The results indicate that 1) collagen is a physiological substrate for the chemotactic phenomenon, 2) intact chemical and/or structural integrity of collagen is required for the induction of platelet chemotaxis, 3) at least one plasma constituent, factor XI, plays an essential role in the chemotactic phenomenon, and 4) contact between collagen and a plasma factor is essential for normal chemotaxis.


Influence of low- and high-pressure baroreceptors on plasma renin activity in humans. We evaluated effects of the low- and high-pressure baroreceptors on plasma renin activity (immunoassay) using graded lower body suction (LBS) in six healthy men. LBS at -10 and -20 mmHg for 10 min decreased central venous pressure without changing arterial pressure and thereby presumably reduced low- but not high-pressure baroreceptor inhibition of renin release. LBS at these levels produced forearm vasoconstriction, but did not increase renin. LBS at -40 mmHg decreased central venous and arterial pulse pressure and thus reduced both low- and high-pressure baroreceptor inhibition. LBS at this level produced forearm vasoconstriction and tachycardia and increased renin from 2.1 +/- 0.4 (mean +/- SE to 7.4 +/- 1.4 ng.ml-1.h-1 (P less than 0.05). In summary, reduction in low-pressure baroreceptor inhibition in humans did not increase renin in the presence of physiological tonic inhibition from high-pressure baroreceptors. Increases in renin did not occur until there was combined reduction of high- and low-pressure baroreceptor inhibition on plasma renin activity.


Motility and blood flow distribution within the wall of the gastrointestinal tract. In anesthetized dogs, the effects of a gentle manipulation of the gut wall, increasing the lumen pressure to 20 mmHg by distention, or an intravenous infusion of physostigmine on blood flow distribution within the wall of the gastrointestinal tract were studied with radioactive microspheres. Manipulation and distension produced rhythmic contractions and increased flow to the distended and manipulated segments. The increased flow was confined to the muscularis serosa; the mucosa-submucosa flow was unchanged. Physostigmine produced a sustained tonic contraction and decreased flow to the whole wall of the stomach, duodenum, jejunum, ileum, and colon. The decreased flow was confined to the mucosa-submucosa; the muscularis serosa flow was unchanged. Thus, the muscularis serosa vasculatures escape the effects of a fall in vascular transmural pressure during the tonic contraction. Manipulation, distention, and physostigmine all increase the percentage of total wall flow perfusing the muscularis serosa. These studies suggest that active hyperemia, similar to exercise hyperemia in skeletal muscles, occurs in the muscularis of gut wall during intestinal contractions.


Intestinal muscle and mucosal blood flow during direct sympathetic stimulation. The effect of direct sympathetic stimulation on intestinal muscle and submucosal-mucosal vasculatures was studied in the anesthetized rat. Blood flow was calculated from direct measurements of vessel diameter and red cell velocity. Stimulation at 4 Hz caused a slight reduction (4%) in muscle flow, but had no measurable effect on submucosal-mucosal flow; stimulation at 8 and 16 Hz caused muscle flow to decrease to 58.3 +/- 8.7% (SE) and 31 +/- 5.1%, respectively, of control flow, and mucosal flow, to 73 +/- 3.4% and 54.1 +/- 1.2%, respectively, of control flow. Calculations of muscle and mucosal vascular resistances from flows and microvascular pressures indicate that muscle resistance increased proportionately more than mucosal resistance at 4 and 8 Hz. However, during stimulation at 16 Hz, the mucosal resistance is only 55% of control, and muscle resistance is not significantly (P less than 0.05) different from control. Therefore, reduction of muscle and mucosal flows during 16-Hz stimulation must be caused by the intestinal arterioles and venules in series with these vasculatures.


Fluid volumes during onset of spontaneous hypertension in rats. Body fluid volumes were examined in young spontaneously hypertensive rats (SHR) and in two strains of age-matched normotensive controls to ascertain whether expanded plasma volume (PV) or extracellular fluid volume (ECFV) was associated with onset of spontaneous hypertension. Mean arterial pressure (MAP) was measured in conscious male SHR, Wistar-Kyoto normotensive (WKY), and American Wistar normotensive (NR) rats 3 h after arterial cannulation. At age 10-14 days no differences in MAP or PV (determine with 125I-albumin) were found between SHR and WKY. At age 18-43 days, SHR had elevated MAP and a small but significant elevation in total body water volume (TBWV; wet weight minus dry weight) compared to WKY and NR; no differences among the three groups were found in PV or ECFV (estimated with inulin). These results provide no evidence that expanded PV or ECFV plays a role in the pathogenic mechanisms of spontaneous hypertension, but do not exclude the possibility of altered vascular compliance. The slightly elevated TBWV in SHR may be related to reduced body fat in SHR.


Role of autoregulation in spatial and temporal perfusion heterogeneity of canine myocardium. Spatial heterogeneity, the region-to-region variation in flow at an instant, and temporal heterogeneity, the time variation of flow in a small region of myocardium, were investigated with radioactive labeled microspheres in 111 regions of left ventricular myocardium. The error of the method was measured by simultaneously injecting four differently labeled microspheres (15 +/- 5 (SD) micron). The coefficient of variation (CV) was 6.5 +/- 1.0%. Spatial variation with autoregulation intact was 21.7 +/- 1.4% (CV); with autoregulation abolished and low perfusion pressure, it was 34.3 +/- 3.7%; and with normal perfusion pressure, 30.8 +/- 6.4% (differences not significantly). This degree of variation was similar in the entire left ventricle and its layers. Forces which tended to cause vessel closure (low perfusion pressure, ventricular systolic pressure, and ventricular diastolic pressure) tended to increase CV. Temporal heterogeneity as measured by 20-s intervals between microsphere injections was 11.1 +/- 1.0% (CV) with autoregulation, 9.8 +/- 1.3% (P less than 0.05) with autoregulation abolished, and 8.4 +/- 0.8% (P less than 0.05) when perfusion pressure was restored. A periodicity of flow cycles of 30-90 s was suggested by the data. These results suggest that spatial heterogeneity is less influenced by autoregulation than by hydraulic considerations, whereas temporal heterogeneity is a component of autoregulation.


Mechanisms of vascular changes in skeletal muscle during asphyxia in the cat. Vascular responses in the hindlimb muscles of anesthetized paralyzed cats during systemic asphyxia were studied. The cats were ventilated with 10% O2-10% CO2-80% N2 for 10-20 min periods, while blood flow to the skinned hindlimb was monitored (electromagnetic flowmeter). Mean arterial pressure rose and hindlimb flow typically fell during asphyxia, implying increased vascular resistance. After sympathetic denervation of the hindlimb, resistance increased  in some groups of animals, and did not change in others during asphyxia. Functional adrenalectomy did not alter these response characteristics. Resistance also did not changes significantly if the control resistance was first increased to the predenervation level by electrically pacing the lumbar sympathetic chain. In contrast, pronounced vasodilatation occurred during asphyxia after blocking of the alpha receptors in the hindlimb (phenoxybenzamine) or after systemic catecholamine depletion (reserpine). We conclude that the vasoconstriction in innervated muscle during asphyxia was caused in part by increased discharge of sympathetic constrictor nerves to the muscle vasculature, with augmentation from a humoral alpha agonist of nonadrenal origin, possibly norepinephrine released from sympathetic nerves throughout the body.


Transient oxygen uptake during myocardial reactive hyperemia in the dog. Oxygen uptake during myocardial hyperemia (MRH) following occlusions of 2.5-30 s was studied in nine anesthetized open-chest dogs by continuous measurement of left anterior coronary blood flow and anterior coronary vein oxygen saturation with electromagnetic flowmeter and fiber-optic catheters, respectively. The ratio of excess oxygen uptake to debt multiplied by 100% was defined as the oxygen repayment ratio (RR) and varied between -50% and +150% (mean 78%). Application of a steady-state Fick formula, as used by previous investigators, results in a profound overestimate of the RR (70-400%, mean 295%). RR is severely distorted by the venous catheter system, and after consideration of these effects we would conclude that the "true" RR in MRH is even lower than we found. Comparing our results with steady-state exercise autoregulation leads us to the following conclusions: 1) chemical kinetic limitations in oxygen release by red blood cells are excluded, 2) a simple direct PO2 regulation of flow is unlikely, but 3) our results are not inconsistent with a more complex integral oxygen regulation or with the metabolic hypothesis.


Lack of specific inhibition of angiotensin II in eels by angiotensin antagonists. Synthetic angiotensins I and II (AI and AII) and natural eel angiotensin were injected with angiotensin antagonists into freshwater-adapted, unanesthetized American eels, Anguilla rostrata, in an attempt to characterize the vasopressor properties of angiotensins in a primitive vertebrate. A converting enzyme inhibitor, SQ 20,881, inhibited vasopressor responses to eel angiotensin (presumably AI) and [Val5,Ser9]AI, but not those to [Asn1,Val5]AII, suggesting that a converting enzyme-like substance may exist in eels. [Sar1,Thr8]AII (10 microgram/kg per min) and [Sar1,Ile8]AII (1 microgram/kg per min), which antagonize angiotensin's action in mammals, showed neither agonistic vasopressor nor antagonistic effects in eels against [Asn1,Val5]AII or eel angiotensin. [Tal8]AII ([8-thienylalanine]AII) and a higher dose of [Sar1,Ile8]AII increased eel aortic pressure themselves and reduced vasopressor responses to [Asn1,Val5]AII. This is presumably a nonspecific decrease in response during the agonistic phase of the analogs. Angiotensin receptors in the blood vessels of eels may differ from those in mammals. Alpha-adrenergic blocking drugs and reserpine partially inhibited the pressor effect of [Asn1,Val5]AII in eels.


Effect of transferrin saturation on iron delivery in rats. Studies were carried out in rats to evaluate the release of iron from monoferric and diferric transferrin. Isoelectric focusing was carried out on plasma tagged at low and high saturations, and it was shown that these represented primarily monoferric and diferric transferrin, respectively. In vivo studies with these tagged plasmas were carried out on normal, iron-deficient, and hypertransfused rats. In all three groups there was a greater in vivo uptake of iron from diferric transferrin by all tissues monitored. Though the amount varied in different animals, the ratio of uptake between diferric and monoferric transferrin iron varied between 1.56 and 2.10 in the erythron and between 2.38 and 2.65 in the liver. These studies indicate that changes in transferrin saturation, by changing the proportion of monoferric to diferric transferrin iron, changed the amount of iron released to tissues.


Satiety effects of cholecystokinin and caerulein in rabbits. Six adult rabbits were maintained on an 18 h fast, 6 h feeding schedule. At the end of the fast either 0.5-40 Ivy dog units (IDU)/kg cholecystokinin (CCK) or 0.9% NaCl were injected intravenously. Feed intake was then measured for 15 min. Significant depression of intake was found at 1 IDU/kg, a 50% depression of intake after 5.5 IDU/kg, and no intake after 40 IDU/kg. Caerulein in similar experiments gave significant depression of intake at 0.125 microgram/kg, a 50% depression after 0.28 microgram/kg, and no intake after 5.0 microgram/kg. In three of these rabbits subdiaphragmatic vagotomy did not abolish the satiety effects of CCK and caerulein. The synthetic octapeptide of CCK was less potent in causing satiety. After CCK or caerulein the rabbits showed typical postprandial behavior. Taste aversion tests failed to demonstrate a strong aversion to flavors associated with the compounds used. These results indicate that exogenous CCK can act as a satiety agent at levels of the same order as the physiological range.


Osmosis, diffusion, convection.

Osmosis, diffusion, convection. We present a tutorial on the mechanisms of and connections among osmosis, diffusion, and convection. For simplicity, we consider only two-component nonelectrolyte solutions under isothermal conditions. Further, we confine our attention to laminar convection with application to the case of flow through narrow channels, as might occur in membranes containing pores or slits. The application of equilibrium and near-equilibrium thermodynamics to flow processes is just like considerations of mechanics with friction, or hydrodynamics. The description of flow processes of more than two atomistic components, either solutions or suspensions, is identical in the dilute limit to the description we give, except possibly when the curvature of the flow field (at the velocity profile) is significant. Flow fields, therefore, naturally divide into three regimes: 1) "one-dimensional" flow fields, e.g., solutions or suspensions in extended regions, whose velocity profile is macroscopically flat (compared to the atomistic curvature); 2) flow fields with significant curvature, e.g., Poiseuille or turbulent fields; and 3) high curvature fields, e.g., narrow flow channels.


Sodium transport in the freshwater mussel, Carunculina texasensis (Lea). Freshwater bivalves maintain a Na steady state in artificial pondwater: JiNa = 1.2 +/- 0.1 mumol/g dry tissue per h. Na uptake is Cl independent. The affinity (KS) of the Na transport system is 0.15-0.23 mmol Na/1. Sodium influx is coupled to H and/or NH4 exchange. Salt depletion stimulates JiNa 300% relative to nondepleted animals with no change in Ks. Injected ammonium ion stimulates JiNa. Sodium transport is inhibited 84% by 0.5 mM amiloride but is not affected by 4 mM NH4 or 1 mM furosemide in the bathing solution or injection of acetazolamide (0.26 mumol/ml blood).


Cholesterol oxidation in primates by simultaneous sterol balance and breath analysis. Six female adult rhesus monkeys and baboons with exteriorized enterohepatic circulations were simultaneously assessed following [26-14C]cholesterol pulse labeling by 14CO2 breath analysis and combined isotopic and chromatographic sterol balance during metabolic steady state. Bile acid synthesis and/or secretion were compared with 14CO2 breath analysis of cholesterol oxidation during short term physiological changes, and with total bile acid diversion and feedback inhibition, and biliary tract obstruction. Cholesterol oxidation by breath analysis compared closely with acidic sterol losses during steady-state conditions (145.6 +/- 23.9 vs 144.6 +/- 24.4 mg/24 h) and was sensitive enough to detect changes resulting from diurnal variation and fasting. The 14CO2 test detected inhibition of bile acid synthesis consequent to bile acid feedback (355 +/- 32 to 88 +/- 31 mg/24 h, P less than 0.001) or biliary tract obstruction (158 +/- 27 to 60 +/- 28 mg/24 h, P less than 0.05) but underestimated increased synthesis induced by acute bile diversion (245 +/- 24 vs. 868 +/- 104 mg/24 h, P less than 0.01 at 24 h). Insignificant 14C was detected by carcass analysis following cessation of exhaled 14CO2.


Humoral and mechanical factors modulating neural input to the renal vasculature. The velocity and magnitude of neurally elicited renal vasoconstrictions decrease with reduction of renal arterial pressure. We investigated the relative roles of humoral and mechanical factors in this decrease. Cats were anesthetized with chloralose. Renal arterial pressure was controlled with an aortic cuff. Vasoconstrictions were elicited by electrical stimulation of the renal nerves until renal vascular resistance stabilized. Renal blood flow autoregulation was maintained during stimulation. Competitive blockade of angiotensin II did not affect the decrease in renal vascular responsiveness to neural input at reduced renal arterial pressure. A mathematical model suggested that a major portion of the decrease in the velocity of vasoconstrictions was a mechanical consequence of autoregulatory vasodilation. However, the model was only able to account for the experimental findings after the blockade of prostaglandin synthesis, and this blockade significantly increased the velocity of vasoconstrictions at renal arterial pressures of 75 Torr or below. These results suggested that prostaglandins as well as mechanical factors played a role in the autoregulatory decrease in responsiveness to sympathetic input.


Actions of some transmitters and their antagonists on salivary secretion in a tick. Cholinomimetics (pilocarpine, carbachol, physostigmine, acetylcholine, acetyl-beta-methylcholine) and sympathomimetics (dopamine, epinephrine), when injected into the hemolymph, provoked salivary fluid secretion in the female ixodid tick Amblyomma hebraeum Koch. Atropine, but not tubocurarine or toxiferine, abolished pilocarpine-induced secretion without reducing the response to dopamine. Reserpine and guanethidine likewise selectively attenuated pilocarpine-induced secretion. Following extirpation of the synganglion, pilocarpine no longer provoked a secretory response whereas dopamine did. Thus, the salivary gland appears to be innervated directly by catecholaminergic rather than cholinergic secretory nerves. It is suggested that pilocarpine elicits salivation by interacting with muscarinic-type cholinergic receptors situated either on the cell bodies of the secretory nerves, or alternatively in the integrative or sensory pathway.


Calibrating compartmental models of neurons. Numerical parameters for a compartmental model of a neuron can be chosen to conform both to the neuron's structure and to its measured steady-state electrical properties. A systematic procedure for assigning parameters is described that makes use of the matrix of coefficients of the set of differential equations that embodies the compartmental model. The inverse of this matrix furnishes input resistances and voltage attenuation factors for the model, and an interactive modification of the original matrix and its inverse may be used to fit the model to anatomic and electrical measurements.


Eye movements and a dynamic stimulus situation. Two experiments were conducted to investigate performance with and without voluntary eye movements in a dynamic stimulus situation. Experiment I used a combined tracking and prediction task. Level of training, complexity of the signal, and visual region sampled were the variables of interest. Experiment II manipulated the same variables in only the prediction task. Thus, the amount of attention allotted to the prediction task was varied between experiments. The d' measure indicated that under peripheral vision instructions accuracy on the prediction task was the same as under foveal vision instructions provided that: (1) the level of task complexity was low, (2) the subjects were well trained, and (3) only the prediction task was performed, or in the dual task situation only visual regions near the fovea were sampled. All other combinations of the variables resulted in a lower performance scores under peripheral vision instructions. Results are interpreted within the framework of current theories of the functional visual field.


Perceived numerosity, item arrangement, and expectancy. Ten sets of dots ranging in number from 7 to 91 per set were presented to 54 subjects. Half were arranged regularly and half randomly. The regular sets were overestimated by an average of 22%, while the random were underestimated by 16% compared with the physical number. Evidence was presented showing that subjects expect results in the opposite direction. The findings are discussed in relation to the expectancy-contrast model of Birnbaum and Veit.


One-trial conditioned suppression: effects of instructions on extinction. Two experimental groups of undergraduate volunteers received a single Pavlovian conditioning trial consisting of a paired presentation of a tone conditioned stimulus (CS) and a shock unconditioned stimulus (UCS). Control groups received either the CS alone or the UCS alone. Subjects from one experimental group were subsequently instructed that they would not receive further shocks, while the other experimental group received no such instructions. The CS alone was then presented once to all four groups while subjects were engaged in a button-pressing task maintained by slide reinforcement. During the latter phase, rate of button-pressing was measured. Classically conditioned suppression of button-pressing was obtained in the noninstructed experimental group but not in the instructed group. The results demonstrate that suppression can be a sensitive index of Pavlovian conditioning in humans but question the use of conditioned suppression as an adequate experimental analog of clinically observed anxiety-motivated behavior.


Visual and nominal matching of physically dimensioned polygons. The present experiment tested the hypothesis that as the visual salience of stimuli decreases, the use of nominal representations as a basis for matching forms increases. The visual salience manipulation was based upon psychophysical studies showing that the dimension compactness possesses higher visual salience for the human observer than the dimension jaggedness. Subjects were asked to judge whether two successively presented forms were the same or different with respect to their position on the compactness or jaggedness dimension. Reaction times suggested an inverse relationship between the use of nominal representations and the visual salience of the dimension employed as a criterion for matching.


Current trends in suicidal behavior in the United States. Suicidal behavior in the United States from 1900 to 1975 is reviewed. The data presented cover demographic variables such as: age, sex, color, and geographic area. While the overall suicide rate continues to increase, the most striking upturn can be seen in both sexes between the ages of 15 to 25 years. The need for a wide range of innovative approaches and increased research is manifest.


Cognitive therapy of depression and suicide. This article reviews the cognitive therapy of depression. The psychotherapy based on this theory consists of behavioral and verbal techniques to change cognitions, beliefs, and errors in logic in the patient's thinking. A few of the various techniques are described and a case example is provided. Finally, the outcome studies testing the efficacy of this approach are reviewed.


Therapy of depressed and suicidal children. The author postulates that depression exists in adolescents, with the level of ego development producing varying clinical pictures. Therapy is based upon the psychoanalytic theory of personality development. Individual treatment is based on age and intelligence of patient, level of ego development, defenses utilized, attitude of parents, and community facilities available.


Tranylcypromine (Parnate)--a study of 1000 patients with severe agitated depressions. This is a study of 1000 patients with severe agitated depressions who were treated with tranylcypromine on an ambulatory basis during a period of 13 years. It was administered in combination with tranquilizers, usually trifluoperazine. Tranylcypromine is a safe, rapidly acting, very effective antidepressant and appears to be the drug of choice in patients with agitated depressions.


The treatment of depressed and suicidal adolescents. Loss and abandonment and distortions of the self-image have special significance for the causation and treatment of depression during adolescence. The management of the manipulative suicidal adolescent and some psychological aspects of pharmacotherapy during this developmental phase are discussed. An eclectic approach is recommended.


Dying without death: the third wish in suicide. A hypothesis is proposed that the nonpsychotic patient in the presuicidal state may have impaired reality testing in which the act of suicide is perceived as not leading to injury or death. Impaired reality testing may be enhanced by intense affects, drugs, and sleep deprivation.


Group therapy with parents of children with leukemia. This paper deals with a six-year experience of group therapy for parents of leukemic children. The group, which includes the hospital staff, strengthens the role of parents, doctors, and nurses. Group therapy is seen as a preventive measure in the sense of working with and partially resolving family stresses. Mourning reactions are dealt with but within limits. The group is built into the total treatment program and, while funding lasts, is not considered to be ancillary or temporary.


Group therapy with rheumatoid arthritic patients. A husband-wife co-therapist team, in clinical collaboration with rheumatologists of the Phoenix Arthritis Center, has instituted a brief inpatient group therapy program in an arthritis unit of a general medical hospital. Problems of initiating the group are presented. Both preliminary findings and research possibilities are discussed.


Treatment of public masturbation by behavioral management. This case history presents a treatment procedure for a nine-year-old girl who masturbated in the classroom. A fading procedure within a behavioral management contract was implemented which proved to be effective. One-, three-, six-, and nine-month follow-ups did not show any evidence of relapse or symptoms substitution.


Psychotherapy under limited options: psychotherapeutic work with a Turkish youth. A patient with highly limited options for psychotherapy, who was moreover not an ideal candidate for standard forms of therapy, was nevertheless able to maintain an effective, if unusual, therapeutic relationship of long duration. The combination of patient, therapist, and milieu gave rise to accomodations and innovations that have practical and theoretical significance.


Serum immunoglobulin and complement levels in tropical pulmonary eosinophilia, and their correlation with primary and their relapsing stages of the illness. Serum concentrations of IgA, IgG, IgM, IgE, C3 and C4 complement components were estimated in 19 patients with tropical pulmonary eosinophilia (TPE). Thirteen of the patients presented during their first episode of TPE and 6 of them during a relapse of the disease. We found a remarkable elevation of serum IgE level in TPE, which is consistent with earlier reports. In contrast, there was a modest increase in IgM levels and unchanged or even lower levels in IgA and IgG immunoglobulin classes. There seemed to be a direct relationship between IgE level and degree of peripheral blood eosinophilia in TPE. The outstanding finding, however, was a nearly threefold higher mean serum IgE level in patients with relapsing disease as compared to that observed in patients during the primary attack. This is the first reported study of circulating complement components in TPE. A significant rise of serum C3 level was found in these patients; there was no similar elevation of serum C4 component.


Strongyloides ratti infections in rats. II. Effects of cortisone treatment. Cortisone (5 mg daily subcutaneously) suppressed both primary and secondary immune explusion of Strongyloides ratti, and reduced the intestinal mast cell response, but did not induce hyperinfection in rats. Cortisone-treated animals expelled primary worm burdens without complication about 2 wk after steroid treatment. A model for gastrointestinal hypersensitivity syndromes in discussed.


Schistosomiasis and anterior spinal artery occlusion. A case of anterior spinal artery occlusion associated with acute Schistosoma mansoni infection is reported, and it is suggested that there is a direct relationship. It is postulated that there is initially an arteritis which leads to obstruction of either the anterior spinal artery itself, its branches, or one or more of the tributary anterior radicular arteries.


Limitations of the intradermal test for schistosomiasis mansoni: experience from epidemiologic studies in a Puerto Rican community. The intradermal reaction with Schistosoma mansoni adult-worm antigen (35-40 microgram/ml nitrogen) was evaluated as an edpidemiologic tool in an endemic Puerto Rican community where the prevalence of S. mansoni infection was 36% and the geometric-mean egg count was 17.6 eggs/g. Subcutaneous injections of antigen were made in forearms, and stool specimens were examined for S. mansoni eggs by a formol-ether concentration method. Of 296 persons tested, 43% had positive intradermal reactions (greater than or equal to 1.0 cm 2  at least twice the area of the control wheal), compared to 48% positive stool examinations. However, sensitivity was low at 36% for children 14 yr old or less, and only 73% to 79% for adults. The test results were very specific for children (96%), but 32% of stool negative adults were positive. Mean wheal area was not directly related to intensity of infection as determined by egg counts in either children or adults, but did increase directly with age. Mean wheal areas were greater for males than females (both children and adults) at all intensities of infection. Because of unsatisfactory sensitivity and specificity the intradermal test may overestimate the prevalence of infection when rates are low, and underestimate prevalence of infection when rates are high. For its proper interpretation, complementary parasitologic data from stool surveys are required.


Effect of transferred adult Schistosoma mansoni on resistance of mice to cercarial challenge. Four or eight adult Schistosoma mansoni surgically transfered to the mesenteric veins of mice survive well and may play a role in resistance to later cercarial challenge. After receiving transfers of single sex or paired flukes, animals exposed to 50or 100 cercariae showed decreased numbers of parasites derived from the challenge infection when compared with control animals 30 days later. Although statistical analysis of the data indicated that the presence of transferred S. mansoni probably had an adverse effect on the survival of worms in a subsequent challenge, the results were interpreted as inconclusive.


Quantitative collection and proteolytic activity of preacetabular gland enzyme (s) of cercariae of schistosoma mansoni. Protease-containing preacetabular gland secretion can be collected from cercariae of Schistosoma mansoni by stimulation with penetration-inducing skin surface lipid, but the method lacks quantitative control because of variability of the lipid. Two commercially available free fatty acid fractions of skin lipid active in stimulating cercariae to penetrate skin, linolenic and linoleic acids, were substituted for skin surface lipid in a technique which provides an improved method of secretion collection. The pattern of protease activity of secreted enzyme (s) was followed throughout patency of infection of a group of snails with the same date of exposure. Day-to-day variability was a characteristic feature of all parameters studied. Major trends were elevated enzyme activity and cercarial emergence during midpatency.


Immunoelectrophoresis tests showing Echinococcus granulosus arc 5 in human cases of Echinococcus vogeli and cysticercosis-multiple myeloma. Human sera from one case of polycystic hydatidosis due to Echnincoccus vogeli and from a case of cysticercosis and multiple myeloma were positive to the immunoelectrophoresis (IEP) test for hydatidosis based on the E. granulosus arc 5 positivity criterion. Arc 5 can therefore be elicited in IEP tests of human sera not only by E. granulosus and E. multilocularis but also by E. vogeli antigens. Whether the cross reaction observed in the second serum was due to the multiple myeloma or to the cysticerci remains to be determined. Although arc 5 antigens are known to be present in Taenia hydatigena cyst fluid this is the first report of an arc 5 due to antigens other than Echinococcus in IEP of human sera.


Histoplasmosis in Belize, Central America. After two small outbreaks of histoplasmosis in Belize, an epidemiologic survey was carried out. Forty percent of 141 persons in two groups tested demonstrated a positive histoplasmin reaction. In one study group there was a significant association between visiting caves and histoplasmin positivity. Histoplasma capsulatum was not isolated in 20 soil specimens collected from outbreak-associated caves, but was isolated from 1 of 26 bats collected from the same caves. The presence of histoplasmosis in Belize, C.A. is documented, and this disease should be considered in differential diagnosis in patients, both residents and visitors in Belize, with compatible clinical presentations.


The landscape epidemiology of rabies in Virginia. Rabies virus, the gray fox, and the Alleghenian Biotic Region form a pathobiocenose; rabies in Virginia exists in a diffuse nidus, the Alleghenian Biotic Region. Physiographic features may serve as barriers or as passageways for epidemic spread of rabies. Epidemic spread is characterized by a radial pattern and a linear northeast-southwest pattern reflecting physiographic features. Incidence of rabies in the fox varies according to seasons. Present control efforts are generally ineffective; under certain conditions, population reduction for control of rabies may be detrimental instead of beneficial.


Epidemiologic, clinical, and virologic observations on dengue in the Kingdom of Tonga. An outbreak of dengue type 2 infection occurred in the Pacific island Kingdom of Tonga in 1974 and an outbreak of dengue type 1 occurred there in 1975. The 1974 outbreak was characterized by relatively mild clinical disease with few hemorrhagic manifestations, a low attack rate, and relatively low viremia levels. The 1975 outbreak was characterized by relatively severe disease with frequent hemorrhagic manifestations and a high attack rate. The differences between the outbreaks could not be attributed to differences in abudance of, or susceptibility to infection of, mosquito vectors or to the prior immune status or other characteristics of the human population. It appeared that a difference in viral virulence was the most likely explanation.


Laboratory and field trials of a slow-release copper molluscicide in St. Lucia. Tests of a slow-release molluscicide containing 50% copper sulfate were under-taken in laboratory and field situations in St. Lucia. In laboratory trials, a granule form of the molluscicide produced 100% mortality of Biomphalaria glabrata down to 4 mg/liter active ingredient (a.i), while the pellet form produced 100% mortality down to 8 mg/liter a.i. In field trials, a dose of 100 mg/liter a.i. in  granule form caused mortality of B. glabrata in banana drains but had no effect on B. glabrata populations in a marsh habitat. In both habitats, the dose of 100 mg/liter produced mortality of other molluscan fauna which caused changes in the molluscan diversity indices. This failure in field trials may have been due to dilution of copper levels caused by flooding and also by uptake of copper by mud and algae.


Acute renal failure following scorpion sting. Fifteen cases of acute renal failure follwoing scorpion sting were studied. The onset of disease was characterized by the occurrence of hemoglobinuria within 24 h of the sting. Most of the patients developed oliguria, edema, hemolytic anemia, and hemolytic jaundice. Renal failure developed within a few days after the sting, and in five patients was severe enough to need dialysis. The onset of diuresis in oliguric patients occurred between 6 and 21 days following the sting. Renal biopsies were possible in four cases and showed mesangial proliferation, variable degrees of tubular changes, and mild interstitial infiltration. The pathogenesis of acute renal failure in these patients is discussed


Biological species in Praomys (Mastomys) natalensis (Smith), a rodent carrier of Lassa virus and bubonic plague in Africa. Plague has been known from countries surrounding Rhodesia from as early as 1935, but was first reported from Rhodesia in 1974. Part of our investigation of the complex ecosystem involving Yersinia pestis is critical assessment of the evolutionary status of natural populations belonging to formal, taxonomic species of implicated rodents. We present data on chromosomal and hemoglobin variation in sympatric populations and laboratory produced hybrids that give unequivocal evidence for at least two biologicql species in the taxon Praomys (Mastomys) natalensis. We argue for the usefulness of the biological species concept as a basis for any ecological investigation into pathogen biology.


Experimental infection with Schistosoma intercalatum (Fisher, 1934) in the chimpanzee (pan troglodytes) and the gibbon (Hylobates lar). Two young chimpanzees (Pan troglodytes) and two adult gibbons (Hylobates lar), each exposed to 1,000 cercariae of Schistosoma intercalatum (Cameroon), were examined at 79 and 82 wk and 61 and 69 wk, respectively, post-infection. Based upon worn returns and tissue egg deposits, these primates can be employed as hosts for experimental schistosomiasis intercalata. However, no histopathology was detected in the urogenital system.


Endorectal ileal pullthrough operation with ileal reservoir after total colectomy. Ileonal anastomosis through an extramucosal rectal muscular tube with construction of a proximal S-shaped ileal reservoir was performed on seven dogs in an attempt to reestablish fecal continence. Five of the dogs survived more than four weeks and experienced fecal continence, although they had frequent stools. The use of Lomotil and Metamucil has assisted in decreasing the frequency of defecation, and also in developing semisolid stools. None of the dogs developed perianal excoriation or ulceration. The ileal reservoir volume averaged 250 ml in the longterm surviving dogs. It is anticipated that this operative technic may have clinical application in selected patients with ulcerative colitis and other diseases primarily involving the rectal mucosa, since the neurogenic and muscular sphincteric mechanism necessary for continence can be preserved. Clinical experience with the ileal reservoir and endorectal pullthrough in one patient has been encouraging.


Surgical correction of complete atrioventricular canal. Operative mortality associated with complete atrioventricular canals has decreased from 75 per cent to as low as 10 per cent. The present report reviews the UCLA Hospital experience with the six children who underwent repair of this defect in the past two years. Emphasis is placed on preoperative assessment, operative technics, and postoperative management.


Management of giant lung abscess.

Management of giant lung abscess. Ten cases of giant lung abscess were treated by one-stage closed tube drainage after initial medical therapy. Sepsis or hemorrhage was relieved in all patients. There were no operative deaths, serious complications, or late recurrences. Three patients have subsequently died from bronchogenic cancer.


Heparin activity monitoring during vascular surgery. Twelve patients undergoing vascular surgery were administered heparin according to preexisting protocols. The response to heparin and the rate of decay were measured by use of the activated coagulation time (ACT). The results showed a significant patient variability to response to and decay of heparin. In addition, a dose-response curve for heparin administration was established in sixteen patients undergoing vascular surgery. The ACT proved to be a simple and accurate monitor of heparin activity. It also made possible a steady state of anticoagulation throughout the duration of the vascular procedure. The reversal of the heparin effect could also be precisely determined by this test.


The dominant role of paracentesis technics in the early diagnosis of blunt abdominal trauma. A simplified method of diagnostic abdominal paracentesis and lavage is described. Liberal application of this method as part of the initial physical examination of blunt trauma patients resulted in identification at first examination of 94 per cent (61 of 65) of those who were to have laparotomy. No case in the series was brought to laparotomy as the result of findings at arteriography, radionuclide imaging, or sonarography, and no intraabdominal problem was missed because of failure to use one of these organimaging technics. The very limited role of these imaging procedures in early management of blunt abdominal trauma is discussed.


Subclavian-carotid transposition for the subclavian steal syndrome. The clinical experience with twelve patients who underwent subclavian-carotid transposition for the subclavian steal syndrome is related. The technical details of the procedure as well as the satisfactory clinical results are described, and the characteristics making it out procedure of choice are summarized.


Genesis of a replantation program.

Genesis of a replantation program. Development of a replantation program entails establishment of microsurgical skills in the laboratory, training in clinical microvascular technics, supervision, if possible, in the first microvascular free flaps, and close liaison with supporting personnel who transport patients, care for them acutely, and carry out their rehabilitation. Of twenty-six replantations or revascularizations (14 incomplete and 12 complete), twenty-three were successful. The three failures (1 complete and 2 incomplete procedures) were all digits, and each was part of a multiple digit injury.


Aortoesophageal fistula.

Aortoesophageal fistula. With the advent of cardiovascular and bypass procedures, aortoesophageal fistula has progressed from the stage of a pathologic curiosity to a treatable lesion. Although the causes of aortoesophageal fistula are varied, a remarkably consistent clinical picture emerges from study of this condition. Chiari's triad of midthoracic pain, sentinel hemorrhage, and a symptom-free interval followed by fatal exsanguination remains the most important clinical finding today. Although contrast esophagography, esophagoscopy, and aortography are important diagnositc aids, immediate left thoracotomy may be the only means of making the diagnosis and saving the patient when hemorrhage is profuse. In most cases (80 per cent of the present series) there is a symptom-free period varying from hours to days from the original sentinel hemorrhage to the final exsanguination. This permits the informed surgeon trained in cardiovascular technics an opportunity to salvage some of these patients. The various methods of aortic and esophageal repair are discussed.


Expanding indications for early parathyroidectomy in the elderly female. In a study of fifty consecutive patients with hyperparathyroidism we have noted: (1) Automated laboratory studies have increased the incidence of diagnosed hyperparathyroidism, especially in the elderly. (2) Bone abnormalities and mental changes are the most frequent symptoms in this older population. (3) Natural history studies have produced some delay in surgical treatment, accentuating mental aberrations and bone-associated deficits. Especially in the elderly, the benefits in personality change, feeling of well-being, and lessened bone deterioration warrant early operation.


Thymoma: a ten year review.

Thymoma: a ten year review. The histopathology, clinical features, treatment, and results are reported in twenty-nine patients with thymoma. Benign and malignant thymomas are differentiated by their invasive characteristics. Surgical excision is recommended for benign lesions. Surgical excision and postoperative irradiation are recommended for malignant thymomas irrespective of the predominant cell type. The recommended treatment for thymoma and the symptomatic results in myasthenia gravis are unpredictable.


Complications of surgery for morbid obesity. From experience with 261 jejonoileal bypass operations performed by one surgeon with the assistance of an interested endocrinologist, many problems have been encountered and many apparently solved. However, there are still some unexplained complications requiring further study, and there must be a continuous follow-up of the patients for some years before the operation can be a completely acceptable treatment for morbid obesity.