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.

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.

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.

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.

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.

Satellite cell response in rat soleus muscle undergoing hypertrophy due to surgical ablation of synergists.

Although the role of satellite cells has been confirmed during skeletal muscle growth and regeneration, their involvement during work-induced muscle growth remains uncertain. In this study, chronically overloaded rat soleus muscles were ultrastructurally monitored following surgical ablation of synergists to examine cytological adaptations of satellite cells and myofibers. The left soleus muscle of 20 female Sprague-Dawley rats (7 weeks of age) was induced to hypertrophy by excising the contralateral plantaris and gastrocnemius muscles under pentobarbital anesthesia. Right limbs were sham-operated and served as controls. On days 3, 7, 14, 21, and 30 after surgery, the soleus muscles were removed and processed for electron microscopy. Two morphologically distinct phases were noted in the surgically overloaded muscles. The first stage (week 1) was characterized by a significant increase in the number of satellite cells, and by more than half of the experimental muscle fibers displaying myofibrillar disruptions, mitochondrial alterations and glycogen pooling. The second phase (weeks 2-4) featured mostly normal, although larger appearing muscle fibers, with the satellite cell frequency remaining slightly elevated. These findings suggest that muscle fiber structural abnormalities, rather than an increase in muscle activity, may play a more significant role in the early activation of satellite cells during compensatory hypertrophy, whereas activation of satellite cells during the later stages may be in response to increased levels of muscle activity.

Embryonic development of tetraploid mice during the second half of gestation.

A small proportion (about 17%) of experimentally produced tetraploid blastocysts are capable of postimplantation development in the randomly bred Q strain of mice. Four newborn mice, three of which were confirmed as tetraploid, were produced but all were eaten by their mother within a few hours of birth. Studies on the embryonic development of tetraploid mice reveal a variety of developmental abnormalities, especially during the later stages of gestation. At 14 1/2 and 16 1/2 days, tetraploid embryos weigh significantly less than corresponding stage diploids, especially so if litter size is taken into account. Histologically, aberrations are found in many different tissues with a clear hierarchy of susceptibility shown among the organs. For instance, yolk-sac-derived blood, and gonads, are invariably affected and the anterior end of the neural tube also seems to be particularly at risk. Possible explanations for the aberrant development are discussed and it is concluded that strictly genetic reasons can be ruled out and that physiological difficulties imposed by the increased size of tetraploid cells and/or problems produced by lack of cell numbers are instrumental in causing abnormal development. Using weight as a guide it is estimated that tetraploid embryos at 14 1/2 and 16 1/2 days gestation contain about one-quarter as many cells as similar stage diploids.

A quantitative ultrastructural analysis of satellite cells in denervated fast and slow muscles of the mouse.

Mononucleated cells located between the external lamina and sarcolemma of denervated muscle fibers within the extensor digitorum longus (EDL) and soleus muscles of adult mice were quantified and examined ultrastructurally from 3 to 65 days after ligating and removing a section of the sciatic nerve. During the first 2 weeks postdenervation, mononucleated cells in denervated muscles were morphologically indistinguishable from satellite cells observed in control muscles. With time, however, many of these satellite-like cells appeared more active as evidenced by a decrease in their nucleocytoplasmic ratio and an increase in their mean percentage of euchromatin material. The number of satellite cells (expressed as a ratio of satellite cell nuclei to satellite cell nuclei plus myonuclei) did not increase significantly until 30 days postdenervation, at which time the mean percentage for the soleus muscle had risen from a control value of 4.1-8.5%, and for the EDL from 1.2-4.1%. Small-diameter, presumably regenerating, myofibers were occasionally observed but only after 30 days denervation. The ultrastructural evidence plus comparisons of euchromatin distributions between myonuclei and satellite cell nuclei support the concept that an increase in the number of satellite-like cells during denervation is more likely due to satellite cell proliferation than to the formation of mononucleated fragments utilizing preexisting myonuclei.