Pneumothorax in an athlete

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Reversible alterations in immunoregulatory T cells in smoking. Analysis by monoclonal antibodies and flow cytometry

We characterized T-lymphocyte subsets in peripheral blood of smokers (N = 60) and nonsmokers (N = 35). Total T-lymphocytes and T cell subsets were similar to nonsmokers in light and moderate smokers. In heavy smokers, total OKT3+ cells were increased, the percentage of OKT4+ cells was decreased, and percentage and total number of OKT8+ cells were increased. The ratio of OKT4+ to OKT8+ lymphocytes was decreased in heavy smokers. The percentage of OKT8+ cells and the OKT4+/OKT8+ ratio returned to normal in heavy smokers six weeks after they stopped smoking. These findings suggest that cigarette smoking causes reversible alterations in immunoregulatory T cells.

Sudden infant death syndrome associated with rotavirus infection

Rotavirus was detected in the stools of five children stricken with sudden infant death syndrome (SIDS) over a three-week period. While none of the children had acute gastroenteritis, four of the five had acute upper respiratory infections. Rotavirus was also identified in tracheal aspirates from two of the infants. Extensive investigations failed to reveal the presence of any other viruses or toxins in specimens obtained from the five children with SIDS. Rotavirus was not found in the stool specimens obtained from a control group of 36 infants including six who died of causes other than SIDS. Future attempts at the prevention of rotavirus infections should be directed at populations susceptible to sudden infant death syndrome.

Effect of bypass surgery on survival in patients in low- and high-risk subgroups delineated by the use of simple clinical variables

A multivariate risk function was developed on data from all 508 medical patients in the Veterans Administration (VA) randomized study of coronary bypass surgery. The variables, in order of importance, were ST-segment depression on resting ECG, history of myocardial infarction, history of hypertension and New York Heart Association functional classification III or IV. These noninvasive variables have been reported to be risk factors in natural-history studies of coronary heart disease (CHD). Applying the risk function to medical and surgical patients of the 1972-1974 cohort yielded a 5-year probability of dying for each patient. Investigation of treatment effects in approximate terciles obtained by collapsing the probability distribution into low-, middle- and high-risk groups showed that surgery was beneficial for patients in the high-risk tercile even after removal of patients with left main coronary artery disease (17% surgical vs 34% medical mortality at 5 years; p less than 0.01). This finding was accentuated when patients in the 10 hospitals with the lowest operative mortality (3.3%) were compared. Mortality results in the low-risk tercile favored medical treatment (medical vs surgical mortality 7% vs 17%; p less than 0.05). The risk function predicted mortality well not only for te VA medical group, but also for an independent symptomatic CHD population from the University of Alabama arteriography registry. This report further delineates the advantages and limitations of coronary bypass surgery in CHD patients with chronic stable angina.

Social consequences of vesico-vaginal fistula in northern Nigeria

The social consequences to the patient who suffers from vesico-vaginal fistula are discussed. Patients are mainly young, come from subsistence farming backgrounds, are often considered to have brought shame on their families, and frequently lose their husband's support, especially if their condition is of long standing. In a society that places a high value on childbearing they have little hope for the future.

Integrity of perfused rat liver at different heat loads

Isolated rat livers were perfused for 90 minutes at temperatures from 37 degrees to 43 degrees C. to evaluate the effects of heat alone on bile production, alanine aminotransferase, and asparate aminotransferase release, and light and electron microscopic structure. Bile production reached a plateau after 45 minutes at 43 degrees C. and after 60 minutes at 42 degrees C. At temperatures between 39 degrees and 41 degrees C., bile production was not significantly different from that produced at 37 degrees C. The timing and levels of alanine aminotransferase and aspartate aminotransferase released into the perfusates were similar, with increases after 45 minutes at 43 degrees C., after 60 minutes at 41 degrees and 42 degrees C. and after 75 minutes at 39 degrees and 40 degrees C. At the end of the 90-minute perfusion, light microscopy indicated vacuolization and severe dissociation of hepatocytes at 42 degrees and 43 degrees C., and pronounced centrilobular vacuolization at 41 degrees C. Electron microscopy demonstrated that hepatocytes had sustained extensive damage at 41 degrees to 43 degrees C. Mild focal and probably reversible damage occurred at 39 degrees and 40 degrees C. Since pH and O2 levels were regulated in a nonrecirculating system and perfusion rates were constant, neither acidosis, hypoxia, nor circulatory inadequacy were responsible for the alterations. Therefore, changes were attributed to the direct effects of heat, reflected a continuum from no detectable damage at 37 degrees C. to occasional necrosis of individual cells at 39 degrees to 40 degrees C. and culminated in widespread necrosis at 41 degrees to 43 degrees C. with a 90-minute exposure. These results reflect a time/temperature relationship over a range of temperatures. A hypothesis for the sequence of events in the pathogenesis of heat-induced hepatic injury is described.

Mitochondrially synthesized protein subunits of the yeast mitochondrial adenosine triphosphatase. A reassessment

Evidence is presented that a mitochondrial translation product (Mr, 32,000) previously thought to be a subunit of the membrane sector of the yeast mitochondrial ATPase is a contaminant, consisting of subunit II of the cytochrome oxidase complex and cytochrome b apoprotein. Our data suggest that only two subunits (Mr, 7600 and 20,000) of the mitochondrial ATPase are synthesized in the mitochondria.

Differentiation of ob 17 preadipocytes to adipocytes. Triggering effects of clofenapate and indomethacin

Conversion of ob 17 preadipocytes to mature adipose cells is accelerated by addition of clofenapate or of indomethacin, in either the absence or presence of insulin. General stimulation of triacylglycerol-pathway enzymes is observed, as well as dramatic increase in endogenous fatty-acid synthesis. This increase is a function of drug concentration and exposure time. In contrast to indomethacin, the continuous presence of clofenapate after the cells reached confluence was required to observe the effects on adipose conversion. Growth of ob 17 fibroblasts in the presence of 5-bromo-2'-deoxyuridine normally prevents their differentiation to adipose cells. Addition of either clofenapate or indomethacin to these cells at confluence overrides this block. The effects of hypolipidemic drugs such as clofenapate observed on a long-term basis in vitro are consistent with the results of studies on adipose tissue in vivo.

Biogenesis of mitochondria. oli2 Mutations affecting the coupling of oxidation to phosphorylation in Saccharomyces cerevisiae

1. Two oligomycin-resistant strains of Saccharomyces cerevisiae have been isolated and shown to have mutations in the oli2 region of the mitochondrial DNA. On solid media containing a non-fermentable energy source, the mutant strains were able to grow only slowly at 28 degrees C and not at all at 18 degrees C or 36 degrees C. 2. When grown in a glucose-limited chemostat at 28 degrees C, the mutant strains were almost completely defective in oxidative metabolism. The mutant mitochondria contained significant levels of all respiratory enzymes, and an active, oligomycin-sensitive ATPase, but the ATP-32Pi exchange activity and P : O ratio were very low. 3. The mutations in these strains are genetically closely linked to mit mutations which have been shown to affect a 20 000-dalton ATPase subunit (Roberts, H., Choo, W.M., Murphy, M., Marzuki, S., Lukins, H.B. and Linnane, A.W. (1979) FEBS Lett. 108, 501-504). Since the mitochondrial ATPase in these mutant strains appears to be fully assembled, the defect in the coupling mechanism is probably a result of a small alteration in the structure of the 20 000-dalton ATPase subunit. 4. When the mutant strains were grown at 18 degrees C, the mitochondria had very low cytochrome oxidase activities, and reduced levels of cytochrome aa3. The largest subunit (Mr 40 000) of this enzyme was not synthesized.

Correlation of serum, tumor, and liver serum glycoprotein: N-acetylneuraminic acid transferase activity with growth of the R3230AC mammary tumor in rats and relationship of the serum activity to tumor burden

The observation that the activity of sialyltransferase (EC 2.4.99.1; serum glycoprotein:N-acetylneuraminic acid transferase) is often elevated in the serum of cancer patients necessitates an elucidation of the interrelationships of this serum enzyme with host tissues. Accordingly, the activity of this enzyme in serum, tumor, and liver was determined at various times after implantation of the R3230AC mammary carcinoma into Fischer rats. Results from samples obtained at numerous, sequential time points demonstrated that significant elevations in serum sialyltransferase enzyme activity occurred only in animals bearing large tumor burdens, i.e., greater than 20 g, or in animals with tumors present for longer than 21 days. In these tumor-bearing rats, the activity of sialyltransferase increased in liver tissue at 21 to 25 days concurrently with the increase in serum enzyme activity, suggesting that the liver may be a potential source of the serum enzyme. Sialyltransferase activity in tumor tissue was quite variable; the activity increased one week after tumor implantation and remained at the same level thereafter. When tumors were excised, the activity of the serum enzyme returned to control values within four days after surgery, suggesting that the half-life of serum sialyltransferase was two days. Serum enzyme levels were again elevated upon regrowth of the tumor. These results show that the serum sialyltransferase alters its activity in conjunction with changes in tumor burden.

Developments in a rehabilitation service for psychiatric patients

This paper deals with the operation of the Rehabilitation Services of the Clarke Institute of Psychiatry in Toronto, Ontario. It is particularly addressed to developments in the service during the last two and one-half years. Included are: a brief historical review; a description of current goals and procedures; plans for the future; a description of the work adjustment program--a new adjunct to the service; some demographic information on clients served in 1977 and 1978; and a discussion of the computerized data collection, outcome studies, program analyses etc. now underway. The tasks of the members of the rehabilitation team will be outlined. Emphasis is placed on the work of occupational therapists who have played a major role in planning, establishing and conducting the service. Flow charts of service procedures are included.

Patterns of skin injury in nonaccidental and accidental injury

The patterns of soft tissue injuries in a group of 154 children reported to protective services for child abuse or neglect were compared with patterns of soft tissue injury found in a group of 91 emergency room patients who sustained an accidental injury and 105 children seen in a pediatric ambulatory clinic. All children in the three groups were 1 to 12 years old. Children in the suspected child abuse and neglect group had significantly more (P less than .01) soft tissue injuries over the cheeks, trunk, genitals, and upper legs. Lacerations were significantly more common (P less than .001) in the emergency room group.

The turnover catabolism and excretion of folate administered at physiological concentrations in the rat

This study examines the distribution of folate-derived compounds in rat urine on a daily basis after the administration of tracer doses of radioactive [3H]pteroylglutamic acid. The identification of 10-formyldihydropteroyl-glutamate in the rat urine, prior to equilibration of the tracer, is also reported for the first time.

The identification of the products of folate catabolism in the rat

Further analysis of rat urine containing labelled catabolites derived from administered 3H- or 14C-labelled folic acid is described. The results support previously described studies, and show that folate catabolism in the rat takes place by cleavage of the C9-N10 bond, and not by excretion of inactive forms of the vitamin which still contain the intact folate skeleton.

Clinical and immunological study of percutaneous revaccination in children who originally received smallpox vaccine subcutaneously

In a large multicenter smallpox vaccination study carried out from 1970 to 1973, it was found that 39% of children who were initially immunized by the subcutaneous route and then challenged percutaneously with a standard vaccination did not have measurable neutralizing antibody upon follow-up. Because of this finding, a percutaneous revaccination study was conducted at the St. Louis study center in 1975 and 1976. There were four study groups, which were composed on the basis of route of primary immunization (subcutaneous or percutaneous) and whether neutralizing antibody was detectable following the original percutaneous challenge immunization. Of 52 children revaccinated, all but four had accelerated reactions. There was no difference in size of lesions or day of maximum erythema among the four study groups. Only 66% of children originally vaccinated subcutaneously who did not have postchallenge neutralizing antibody had measurable neutralizing antibody following revaccination. Transformation studies with vaccinia viral antigen before and after revaccination were performed on lymphocytes from 50 children. There was no appreciable differences in responses either before or after revaccination when the four groups were compared. However, the mean stimulation ratio for the total group increased from 2.4 before revaccination to 4.6 3 weeks later. In primary subcutaneous vaccine recipients without pre-revaccination neutralizing antibody, lymphocyte transformation correlated directly with the neutralizing antibody response.

Somatostatin inhibition of glucose-induced electrical activity in cultured rat islet cells

Electrophysiological studies of rat islet cells in monolayer culture were undertaken to determine the role of transmembranous ionic fluxes in the inhibitory action of somatostatin on insulin release. In the presence of somatotropin release inhibiting factor (SRIF) (2.5 nM), hyperpolarization occured with or without glucose (16.6 mM) in the medium. SRIF also inhibited the incidence of glucose-induced spike activity. The inhibitory action of SRIF occurred within 5 min and was readily reversible. An increase in extracellular K+ (5-13 mM) or Ca2+ (2.3-4.6 mM) prevented SRIF inhibition of glucose-induced electrical activity. The secretory response of cultured islets to glucose (16.6 mM) was completely inhibited by SRIF (2.5 nM). The presence of high [Ca2+]o or [k+]o enhanced insulin release in the presence of SRIF and glucose. Although phentolamine (5.0 microgram/ml) did not block the inhibition of glucose-induced electrical responses by SRIF, it prevented the inhibitory action of epinephrine (0.2 microgram/ml). It is concluded that the primary action of SRIF is to alter transmembranous cationic fluxes, as manifested by hyperpolarization and a decrease in the incidence of spike activity, which may prevent glucose from eliciting a normal secretory response.

Exchange of phospholipids between mitochondria and microsomes in vitro stimulated by yeast cell cytosol

Yeast cell cytosol stimulated the exchange of phospholipids between yeast mitochondria and microsomes in vitro, and also between organelles isolated from rat liver. The major phospholipids exchanged in both cases were phosphatidylinositol and phosphatidylcholine, together with smaller amounts of phosphatidylethanolamine. Evidence was also obtained that interconversion of phospholipids occurred during the incubation, probably via base exchange mechanisms.

Defective bud formation in human cells chronically infected with subacute sclerosing panencephalitis virus

Human prostate cells chronically infected with the Mantooth strain of subacute sclerosing panencephalitis (SSPE) virus multiply normally, fuse only occasionally to form giant cells, and yet have twisted intracytoplasmic nucleocapsids. These cells are able to support replication of vesicular stomatitis virus, although they release only small amounts of SSPE virus. To determine why carrier cells do not produce virus, they were examined with techniques for surface replication, freeze-fracturing, and immunoperoxidase labeling with SSPE antibody. The surface of carrier cells, like that of productive cells, is characterized by ridges crowned with viral antigens and devoid of the intramembrane particles revealed by freeze-fracture techniques. Since surface ridges form where nucleocapsids attach to the membrane, the shape and length of ridges are indicative of the shape and length of the underlying nucleocapsid. Whereas ridges on productive cells are serpentine in shape, those on carrier cells are typically straight or hairpin shaped, and the hairpin ridges are twice as long as serpentine ridges on productive cells. Furthermore, the spacing between ridges on carrier cells is never as small as that in productive infections, so that continuous sheets of viral membrane are never formed. The majority of carrier cells lack the round viral buds observed in productive cells but have, instead, many elongated processes attached to the cell surface. Each of these processes contains one or two hairpin ridges overlying hairpin-shaped nucleocapsids. These "hairpin buds" are restricted to a single region of the carrier cell surface, whereas viral buds are distributed over the entire surface of productive cells. Thus, there are several structural defects in carrier cells that depend on the specific interaction of a certain viral strain with a certain cell type. These defects prevent the deployment of viral antigen in some regions of the cell surface, the formation of nucleocapsids of normal length, the coiling of attached nucleocapsids, and the consolidation of sheets of viral membrane into spherical buds with the nucleocapsids coiled inside. These defects may account for the failure of carrier cells to shed infectious virus.

The use of a single venous blood sample to assess oxygen binding in haemoglobin

The measurement of pH, PO2, PCO2 and SO2 in a single venous blood sample can be used to determine the P50 at standard or at in vivo conditions. This technique makes it feasible for a physician, firstly, to make an assessment of the net adaptation of the red cell to reductions in blood oxygen content or flow and, secondly, to make an initial assessment of whether a haemoglobin with altered affinity for oxygen is present in subjects with polycythaemia or anaemia.

Effect of isoleucine deprivation of rabbitpox virus DNA synthesis in mouse L cells

Synthesis of rabbitpox DNA was inhibited in mouse L cells deprived of isoleucine. Time-course patterns of incorporation of radiolabelled precursors into viral DNA revealed that synthesis of viral DNA began about 6 h after reversal of the isoleucine-deficient state.

Factitious changes in binding of oxygen to hemoglobin when based on extracellular pH in the presence of certain blood additives like radiographic contrast media

Construction of oxygen-hemoglobin DISSOCIATION CURVES BASED ON EXTRACELLULAR PH and using blood tonometered with 5 per cent CO2, is misleading under certain experimental conditions. These include the presence in blood of poorly penetrating non-ionic molecules like sucrose of poorly penetrating anionic aompounds like radiographic contrast materials. False conclusions regarding the position of the oxygen-hemoglobin dissociation curve can result because of the disturbance of the normal pH gradient between plasma and red cell induced by such chemicals.

The relationships between arterial oxygen flow rate, oxygen binding by hemoglobin, and oxygen utilization after myocardial infarction

The interrelationships of arterial oxygen flow rate index, oxygen binding by hemoglobin, and oxygen consumption have been examined in patients with acute myocardial infarction. Proportional extraction of oxygen increased in close association with decreasing oxygen flow rate, and hence, whole body oxygen consumption was constant over nearly a three-fold variation in arterial oxygen flow rate. A reduction in hemoglobin-oxygen affinity at in vivo conditions of pH. Pco(2) and temperature also occurred in proportion to the reduction in arterial oxygen flow rate. Therefore, the increased proportional removal of oxygen from arterial blood at low oxygen flow rates, required to maintain oxygen consumption, may have been facilitated by the reduced affinity of hemoglobin for oxygen at in vivo conditions. However, the decrease in affinity did not appear to explain more than 30-40% of the increased extraction. Respiratory alkalosis was a frequent occurrence in these patients and 2,3-diphosphoglycerate was positively associated with blood pH as well as with the time-averaged proportion of deoxyhemoglobin in arterial and venous blood.Hemoglobin-oxygen affinity measured at standard conditions and the mixed venous oxygen saturation were equally good indicators of reduced arterial oxygen flow rate in patients without shock. However, Svo(2) is more easily measured and is a more useful indicator of reduced oxygen flow rate, since its relationship to oxygen flow appears to be independent of affinity changes and time.

The effects of cyproterone acetate on the spontaneous activity and seminal vesicle weight of male rats

The wheel-running activity of 19 male rats was examined before and after castration. Castration significantly reduced spontaneous activity. Testosterone propionate (TP) administration increased activity to levels before castration. Cyproterone acetate given with TP did not inhibit the increase in activity but inhibited the growth of seminal vesicles.