Pneumocystis carinii pneumonia complicated by lymphadenopathy and pneumothorax

A case of generalized Pneumocystis carinii infection presented as hilar and mediastinal lymphadenopathy and was complicated by spontaneous pneumothorax. Extrapulmonary P carinii infection in patients with acquired immunodeficiency syndrome is rare, and pneumothorax is even rarer. The purpose of this report is to call attention to these atypical features of P carinii infection in patients with the acquired immunodeficiency syndrome.     

Parallel adrenal and renal abnormalities in young patients with essential hypertension

To determine whether the previously described abnormalities in adrenal secretion and renal blood flow in essential hypertension are associated, we examined the responses to the relevant systems in 18 patients with essential hypertension. Young patients, under 30 years of age, were studied to minimize the likelihood that the phenomena were secondary to long-standing hypertension. To achieve a wide span of sodium balance, studies were performed during a high (200 mEq) sodium intake, a restricted (10 mEq) sodium intake and a restricted sodium intake supplemented by a further short-term diuretic-induced volume deficit (furosemide, 180 to 300 mg, to reduce body weight by 1 to 1.5 kg). The indexes measured included cardiac output (indocyanine green indicator dilution), plasma volume (¹²⁵I albumin space), renal blood flow (radioxenon transit), plasma renin activity and aldosterone levels and aldosterone secretory rate. All of these variables, with the exception of Mood pressure and total peripheral resistance, were within the normal range during the two diets. However, the aldosterone secretory response to diureticinduced volume depletion on a low-sodium diet was clearly blunted in nine subjects. These nine subjects (abnormal responders) had a virtually absent aldosterone increment (23 ± 34 μg per 24 hours) compared with the normal responders (502 ± 70 μg per 24 hours). In addition, renal blood flow was significantly higher in these same nine subjects during both a high sodium intake (434 ± 19 versus 342 ± 26 ml/100 g per minute) and a restricted sodium intake (446 ± 11 versus 285 ± 39 ml/100 g per minute). Yet, there were no significant differences between these two groups in sodium or potassium balance, blood pressure, plasma volume, cardiac index or plasma renin activity during a high or low sodium intake. Normally, control of both aldosterone release by the adrenal and renal perfusion is dominated by angiotensin; an apparently blunted response of both systems suggests that there may be a generalized abnormality in the way angiotensin interacts with its target tissues in many young patients with essential hypertension.     

Normal venous circulation of the gastroesophageal junction. A route to understanding varices

A study into the normal anatomy of the venous circulation of the gastroesophageal junction was undertaken using three complementary techniques (radiology, corrosion casting, and morphometry). Four distinct zones of venous drainage were defined as follows: (a) gastric zone, characterized by a longitudinal venous distribution; (b) palisade zone, composed of parallel vessels arranged in groups, lying mainly within the lamina propria; (c) perforating zone, characterized by "treble clef" shaped veins, which collect and channel blood into extrinsic veins; and (d) truncal zone, composed of four or five deep lying descending veins. This venous system appeared to be mainly distributed within the esophageal mucosal folds. The anatomic pattern suggests that venous flow is bidirectional at the palisade zone, which acts as a high-resistance watershed region between the portal and azygos systems. In patients with portal hypertension this normal vascular system has to accommodate greatly increased venous flow, and the anatomy as demonstrated here offers insight into variceal development.     

Results of the Senning procedure in infants with simple and complex transposition of the great arteries

Because of interest in the arterial switch operation, recent experience with the Senning operation in patients with simple and complex transposition of the great arteries (TGA) was examined. Between 1982 and 1985, 35 patients with simple TGA (group I) and 10 patients with complex TGA (group II) underwent a Senning operation. Mean duration of follow-up was 14 months for group I and 24 months for group II. In group I, 1 patient died early and no patient died late; infrequently, right ventricular dysfunction, tricuspid regurgitation, baffle obstruction or arrhythmias occurred. In group II, no patient died early and 3 died late. In addition, many patients required prolonged digoxin therapy. Because the arterial switch operation has a high early mortality risk and an undetermined long-term morbidity and mortality risk, the Senning operation (or other venous switch operations) is considered the preferred surgical approach for simple TGA. In contrast, an arterial switch operation is performed in patients with complex TGA (without subpulmonic obstruction). Comparison of the early and late morbidity and mortality of the arterial vs the venous switch operation may be helpful in selecting the appropriate surgical approach to complex TGA.     

Cardiac fibroblasts produce leukemia inhibitory factor and endothelin, which combine to induce cardiac myocyte hypertrophy in vitro

Cardiac fibroblasts in culture produce factor(s) that induce hypertrophy of neonatal rat ventricular myocytes in vitro. As in vivo, the myocyte hypertrophy response in culture is characterized by an increase in cell size and contractile protein content, and by the activation of embryonic genes, including the gene for atrial natriuretic peptide. The purpose of this study was to identify the factor(s) produced by fibroblasts that induce myocyte hypertrophy. The fibroblast hypertrophy activity was inhibited using a combination of the endothelin A receptor blocker BQ-123 and an antibody to leukemia inhibitory factor. The individual antagonists each caused a partial inhibition. The mRNAs for both leukemia inhibitory factor and endothelin were detected by RT-PCR analysis and the concentration of both proteins was determined to be approximately 200 pmol/L in the conditioned medium using immunoassays. Purified leukemia inhibitory factor and endothelin each induced distinctive morphological changes in the myocytes. Their combination generated a different morphology similar to that induced by fibroblast conditioned medium. Each factor also induced atrial natriuretic peptide production, but both were required for the myocytes to produce the levels measured after exposure to fibroblast conditioned medium. These results show that hypertrophy activity produced by cardiac fibroblasts in culture is a result of leukemia inhibitory factor and endothelin.     

Chronic withdrawal of a high-palatable obesity-inducing diet completely reverses metabolic and vascular abnormalities associated with dietary-obesity in the rat

Chronic consumption of a high-palatable diet induces obesity and markedly impairs arterial relaxation. We have recently reported that endothelial function is only partially resorted after acute withdrawal of palatable diet. Therefore, this study was designed to investigate the effects of chronic withdrawal of high-palatable obesity-inducing diet on metabolic and vascular function in rats. Wistar rats were fed either standard laboratory chow throughout (controls) or given a highly-palatable diet (diet-fed) for 15 weeks; or fed the diet for 8 weeks and then returned to chow (diet-to-chow) for further 7 weeks before sacrifice. Diet-fed rats had higher body weight, fat mass, liver and heart weight than both chow-fed and diet-to-chow groups (P<0.01 for all). Compared with chow-fed and diet-to-chow groups, diet-fed rats had significantly raised fasting plasma levels of insulin, leptin and triglycerides levels (each +180%; P<0.0001), but not glucose or non-esterified fatty acids. There were no significant differences between any metabolic parameters between chow-fed and diet-to-chow groups. Mesenteric arteries showed no significant differences between any groups in KCl-induced tension generation, while diet-fed groups had significantly higher noradrenaline-induced vasoconstriction than both chow-fed and diet-to-chow groups. Maximum endothelial-dependent vasorelaxation responses to carbamylcholine (CCh) were significantly (by 23%; P<0.001) attenuated in the diet-fed group. This defect was abolished in the diet-to-chow group. There were no significant differences in endothelium-independent vasorelaxation responses to sodium nitroprusside between the three groups. In conclusion, palatable diet induces obesity and metabolic abnormalities as well as a marked endothelial dysfunction. These abnormalities are completely reversed by chronic withdrawal of the obesity-inducing high-palatable diet.     

Dual effect of disopyramide on atrial and atrioventricular conduction and refractory periods.

Disopyramide has been shown in conditions of cholinergic blockade to have a depressant effect upon sinus node automaticity and the atrial refractoriness. It also prolongs atrioventricular conduction and increases atrioventricular refractoriness. These effects may often be masked in vivo by the anticholinergic effects of the drug.     

Intravenous quinine therapy of hospitalized children with Plasmodium falciparum malaria in Kinshasa, Zaire

To examine the clinical and parasitologic efficacy of quinine, we studied 34 children (7 months-13 years old) with severe or moderately severe Plasmodium falciparum infections. Quinine 10 mg/kg every 8 hr for 3 days was administered, initially by intravenous infusion of quinine formate followed by oral quinine dihydrochloride when tolerated. Thirty-three of the 34 patients were clinically well and had negative malaria smears 7 days after the initiation of therapy; 1 child, who presented in coma, died 29 hr after enrollment. The mean fever clearance time was 44.1 hr, and the mean parasite clearance time was 59.6 hr. A mean peak quinine level of 9.7 ppm was attained after the second dose of quinine, and the minimum concentration was maintained at 5-7 ppm during the 2nd and 3rd hospital days. In vitro testing was conducted with parasites from 10 patients: 9 isolates were resistant to chloroquine, and inhibition of schizont development with quinine occurred at a concentration of 8-32 pmol/well.