Pneumocystis carinii pneumonia after thoracic duct ligation and leakage.

A case of Pneumocystis carinii pneumonia was induced through immunosuppression following thoracic duct ligation. The patient initially presented with an esophageal adenocarcinoma, which was totally resected. She is human immunodeficiency virus-negative and not undergoing immunosuppressive treatment.

Actions of growth hormone-release inhibiting hormone (somatostatin) on the renin aldosterone system.

Administration of growth hormone-release inhibiting hormone (GH-RIH, somatostatin), as a 90 minute infusion (10 mug/min), to 3 healthy young men under conditons of active renin secretion acheived by pretreatment with furosemide (80 mg daily for 5 days), caused a mean 30% fall in plasma renin activity, which returned to basal levels immediately after stopping the GH-RIH infusion. Plasma aldosterone levels were not affected during the course of this experiment.

Effects of supplemental instruction on mean test scores and failure rates in medical school courses.

PURPOSE: To determine whether supplemental instruction offered to first-year medical students reduces the number of examination failures. METHOD: A student-run, optional, supplemental-instruction program called the Medical Scholars Program (MSP) was offered at no cost to all first-year students at the University of Southern California School of Medicine in 1994-95. Supplemental instruction was offered in a small-group format in biochemistry, gross anatomy, microanatomy, and physiology. Weekly two-hour sessions were conducted by second-year medical students during the first trimester of the year-1 curriculum. Mean test scores and failure rates for students considered academically at risk and those not at risk were compared between the class entering in 1994 and the classes matriculating during the preceding three years. At-risk students were defined as those with a total Medical College Admission Test score below 26 and a science grade-point average below 3.0. Comparisons were performed using two-tailed t-tests and chi-square tests. RESULTS: Statistically significant increases in mean test scores were achieved on most examinations by the class exposed to the MSP. Failure rates for at-risk students decreased by 46% during the year the MSP was offered. CONCLUSION: Supplemental instruction can significantly improve student performance and therefore retention, particularly among at-risk students.

Greater emotional distress is associated with accelerated CD4+ cell decline in HIV infection.

An investigation was conducted to explore the relationship between emotional distress and HIV progression. One hundred twenty-five homosexual, HIV-positive males participated in a 12-month longitudinal investigation. Psychosocial data were collected at 6-month intervals and CD4+ data were collected from diagnosis to the end of the investigation. Principal component analyses were performed initially to identify factors of emotional distress and health status. In addition, CD4+ reliability assessments were performed to ensure the validity of the prognostic assessments made. As a result of these analyses, 47 individuals were eligible for the main analyses. The results from a stepwise regression revealed that disease progression was significantly predicted by CD4+ count at diagnosis (32% of variance) and emotional distress (17% of variance), but was unrelated to subjective perceptions of health. The data suggest that some of the variability in HIV progression can be attributed to emotional distress.

Mortality and survival trends in patients with AIDS in north east England from 1984-1992.

OBJECTIVE: to study trends in mortality and survival in patients with AIDS attending an ID unit. METHOD: retrospective analysis of patients developing an AIDS-defining illness between April 1984, and November 1992. Survival was analysed by calculation of survival product-limit. RESULTS: 71 patients were analysed (including four women), 23 of whom are still alive. Pneumocystis carinii pneumonia (PCP) was the most frequent AIDS-index diagnosis: n = 36 (51%); 24 of these patients have died. HIV encephalopathy was the most frequent diagnosis at death; n = 16 (22.5%), followed by mycobacterial infection; n = 11 (15.5%), and PCP and CMV infection, each occurring in 10 (14%). One-, 2- and 3-year survival probabilities for patients with AIDS before 1987 were 0.46, 0.15 and 0 compared with probabilities of 0.63, 0.5 and 0.3 in those diagnosed after 1987; log rank -P < 0.01. One- and 2-year survival probabilities in patients who received at least 3 months' zidovudine (AZT) therapy were 0.76 and 0.53 in those who are still alive compared with 0.55 and 0.33 in the deceased, while values for deceased AZT-naive patients were 0.29 and 0.1; -P < 0.01. Thirteen (27%) deaths occurred within 2 months of an AIDS-index disease. In 10 patients this was their first presentation to the department. PCP accounted for 8 (61%) of these deaths. CONCLUSIONS: survival in patients with AIDS has increased since 1987, when AZT was introduced. Early AIDS-related deaths are frequent in patients who have had no prior medical care. This has implications for education and provision of care in individuals with asymptomatic HIV infection.

Early development in the mouse: would it be affected by microgravity?

Gravity has been identified as a morphogenetic signal in Amphibian and bird embryonic development so it is plausible that it might be such in mammals as well. Since early mammalian development shows some apparently significant differences to these other groups, a brief summary of mouse embryogenesis will be given identifying events in which polarity is an important feature and consequently, in which gravity may be a causative factor. These include compaction and polarization during cleavage, establishment of the radial axis, the embryonic-abembryonic axis, the dorso-ventral axis, and the anterior-posterior axis, implantation, and the later rotation of the embryo. The experimental data on these morphogenetic steps will be discussed and an assessment of the possible involvement of gravity will be made.

Primary tuberculosis of the posterior oropharyngeal wall.

We report a case of primary tuberculosis of the posterior oropharyngeal wall presenting with sore throat, fever and malaise. Pharyngeal tuberculosis is rare and usually occurs with primary pulmonary disease. Primary disease has been reported in small numbers in the nasopharynx and palatine tonsil but never before, to our knowledge, in the posterior oropharyngeal wall.

Oral cancer, fever of unknown origin, and listeriosis.

Listeriosis is a rare cause of fever of unknown origin in patients with oral cancer. We report two patients who, because of pain and discomfort, ate large quantities of soft cheeses; this caused listeriosis and fever. Both cases responded to high doses of amoxycillin.

Sarcoidosis of the tongue--a case report.

A case of sarcoidosis, unusual in that it was confined to the tongue, is reported in a 50 year-old female. The condition resolved after 1 year of steroid therapy and excision of fibrous tethering bands. Intra-oral sarcoidosis should be considered in the differential diagnosis of lingual swelling and induration.

Overwhelming pneumoccoccal sepsis in two patients splenectomised more than ten years previously.

Asplenic individuals are known to be at a higher risk of developing serious and occasionally fatal sepsis. Prophylactic measures are generally recommended for the first few years post-splenectomy. We report two cases of severe Pneumococcal Sepsis occurring more than 10 years post-splenectomy leading to prolonged hospitalisation and long term morbidity and suggest that Prophylactic Penicillin should be taken life-long.

Giant cell arteritis--A cause of pyrexia of unknown origin.

Giant cell arteritis may present atypically with symptoms of malaise, anorexia, weight loss and fever that could lead to diagnostic difficulties. We describe two cases which the prominent initial feature was protracted pyrexia. Clinicians should seriously consider temporal artery biopsy in such cases.

Pancreatic exocrine insufficiency in HIV-positive patients.

OBJECTIVES: We describe the management of a cohort of eight HIV-positive patients on antiretroviral medication with evidence of pancreatic insufficiency consisting of chronic diarrhoea and a low faecal elastase measurement. PATIENTS AND METHODS: Twenty-two patients with chronic diarrhoea for whom a faecal elastase measurement was available were identified retrospectively. We compared baseline demographic characteristics, antiretroviral treatment and symptoms of steatorrhea between patients with evidence of pancreatic insufficiency, i.e. a low faecal elastase measurement of <200 microg/g (cases), and patients with evidence of normal pancreatic function, i.e. a normal faecal elastase measurement of >200 microg/g (controls). We describe the management of the patients with evidence of pancreatic insufficiency. RESULTS: Of the 22 patients, eight had evidence of pancreatic insufficiency, i.e. a low faecal elastase measurement. Comparing cases with controls, cases were more likely to have symptoms of steatorrhea (P=0.03) or to have lost weight (P=0.02). Cases were also significantly more likely to have taken didanosine (ddI) as part of their antiretroviral treatment when their symptoms started. Seven cases were treated with oral pancreatic supplements and all had symptomatic improvement of their diarrhoea. One patient stopped treatment with oral pancreatic supplements because of side effects without a relapse of symptoms; he had also stopped zalcitabine (ddC). CONCLUSIONS: We believe that measurement of faecal elastase to detect pancreatic insufficiency should be part of the standard investigation of HIV-positive patients with chronic diarrhoea alongside assessment for other causes of diarrhoea. Faecal elastase measurements should be requested, in particular, in all patients with diarrhoea and weight loss, or symptoms of steatorrhea, and in those on treatment with an antiretroviral regime containing ddI. If the faecal elastase level is low, a switch of antiretroviral medication to a nonddI/ddC-containing regime should be considered and treatment with oral pancreatic enzyme therapy should be instituted.

An autoradiographic study of satellite cell differentiation into regenerating myotubes following transplantation of muscles in young rats.

Satellite cells were traced autoradiographically during the regeneration of skeletal muscle in young Sprague-Dawley rats. Approximately 31% of the satellite cells in uninjured muscles appeared labelled after three injections of tritiated thymidine; none of the myonuclei were labelled in the same muscles. Four to six days after transplanting the radioactive muscles to non-radioactive littermates, regenerating myotube nuclei in the host appeared labelled. Thus, this study confirms that satellite cells in young rats can differentiate into multinucleated myotubes following muscle injury.

Myogenic cell formation in regenerating rat skeletal muscle injured by mincing. I. A fine structural study.

The degenerative and early regenerative events following mincing and autotransplantation of rat skeletal muscle were examined at the ultrastructural level. During the first eight hours after injury, myonuclei undergo pyknosis, mitochondria become enlarged and vesiculated, myofilaments appear less distinct than normal and the sarcolemmata either disappear or become extensively fragmented. Further degeneration of the myofibers progresses slowly until macrophages and polymorphonuclear neutrophils invade the degenerating sarcoplasm between one to four days after mincing. Scattered throughout the minced muscle implant during the first 24 hours after injury are small, viable-appearing, undifferentiated cells located between the external lamina and degenerating sarcoplasm. Such cells, which are structurally similar to satellite cells seen in uninjured muscle, are believed to be regenerating presumptive myoblasts due to their mesenchymal-like morphology and sublaminar position. External laminae of the injured muscle fibers do not undergo immediate degenerative changes, but rather persist during the first three to six days as laminar tubes within which spindle-shaped myoblasts and newly formed myotubes are frequently observed. Examples of regenerating myoblasts in the process of budding-off from damaged muscle fibers were not observed in this study. Therefore, the evidence suggests that satellite cells are the major source of regenerating myoblasts in skeletal muscle of the rat.

Myogenic cell formation in regenerating rat skeletal muscle injured by mincing. II. An autoradiographic study.

Myonuclei and satellite cell nuclei were differentially labelled with 3H-thymidine in uninjured skeletal muscle of young rats and then traced autoradiographically at intervals after mincing the radioactive hindlimb muscles to determine the source of regenerating presumptive myoblasts. Labelled nuclei were detected by light microscopic examination of 1-micron thick autoradiographs and identified by electron microscopic examination of an adjacent section. Repeated injections of 3H-thymidine during fetal and neonatal development, followed by a 4- to 5-week maturation period, resulted in labelling of 20% of the myonuclei. Satellite cells were not observed to be labelled in this series. Eight to sixteen hours after mincing, 20% of the pyknotic myonuclei were labelled, whereas none of the regenerating presumptive myoblasts appeared labelled. A single injection of 3H-thymidine administered to 18-day-old rats, followed by sacrifice within ten hours, resulted in labelling of 23% of the satellite cell nuclei. Myonuclei were not observed to be labelled in this series. Eight to sixteen hours after mincing, silver grains were detected over both pyknotic and regenerating cell nuclei. These experiments indicate that many satellite cells survive muscle injury and transplantation to become regenerating myogenic cells at a time when most, if not all, myonuclei are undergoing pyknosis.

Satellite cell distribution within the soleus muscle of the adult mouse.

The frequency of satellite cells was quantitated by electron microscopy in five proximal to distal regions of the soleus muscle of adult mice. In all, 236 satellite cell nuclei and 4, 475 myonuclei were counted on 51 transverse thin sections. The mean percentage of satellite cells, as a ratio of satellite cells to myonuclei, per region was found to be 5.4%, 5.3%, 5.0%, 5.2% and 4.9% for the most proximal to distal areas, respectively. Analysis of variance revealed no significant differences between either the regions or the animals studied. The number of satellite cell nuclei per cross-sectional area of muscle was also calculated for each of the five regions, and these values did not vary significantly from the proximal to distal ends of the muscle. Despite the fact that satellite cells were frequently noted in close association with cross-sectional profiles of myoneural junctions, this study establishes that the number of such perisynaptic satellite cells was not large enough to affect significantly the mean percentages of all satellite cells counted within the motor endplate regions(areas 3 and 4) of the soleus muscle. It is concluded from this study that satellite cells are uniformly distributed throughout the whole muscle.