Surfactant production by neoplastic type II pneumocytes

A bronchioloalveolar carcinoma of type II pneumocyte differentiation with abundant intraluminal secretion, histochemically and histologically mimicking alveolar proteinosis, is described. The tumor was of the diffuse type, involving almost the entire lower lobe of the left lung. The luminal aspect of the cells showed evidence of apocrine secretion. Ultrastructurally, the cells were characterized by the presence of cytoplasmic lamellar bodies. There were occasional cells with intranuclear tubules, and numerous rounded fragments of cytoplasm were present in the lumen as evidence of the apocrine activity. The intraalveolar secretion was composed of lamellar bodies in various stages of dissolution, tubular myelinlike networks characteristic of surfactant, and amorphous, granular material. This is the first reported instance of morphologic demonstration of surfactant secretion by a bronchioloalveolar carcinoma.

Treatment of childhood prednisone-resistant nephrotic syndrome and focal segmental glomerulosclerosis with intravenous methylprednisolone and oral alkylating agents

Patients with prednisone-resistant nephrotic syndrome and biopsy-proven focal segmental glomerulosclerosis were treated with intravenous methylprednisone. After the first 2 weeks of therapy, the average urine protein excretion decreased from 247 to 96 mg/m2/h (p less than 0.04). Two of the 7 patients have had long-term, nearly complete remissions. The other patients relapsed. One relapsing patient was retreated with methylprednisolone and is now in remission. Four relapsing patients were treated with alkylating agents, in combination with methylprednisolone. All of these patients entered complete or partial remissions. Methylprednisolone causes a significant decrease in the proteinuria of children with focal segmental glomerulosclerosis. In addition, although the follow-up period is relatively short, it would appear that methylprednisolone, often in conjunction with an alkylating agent, has significantly improved the clinical status of these patients.

Platelet adhesion to cultured vascular endothelial cells. A quantitative monolayer adhesion assay

We have developed a sensitive in vitro method for measuring the adherence of platelets to cultured vascular cells. Human platelets, in citrated plasma, were radiolabeled with [3H]adenine to achieve a specific activity 100 to 1000 times greater than that obtainable with chromium-51 or [14C]serotonin. After exposure of cultured cell monolayers to radiolabeled PRP, nonadherent platelets were removed by a standardized wash procedure, and the number of adherent platelets calculated from liquid scintillation measurements. Significant release of platelet-associated radioactivity was not detectable after challenge with standard aggregating agents, and uptake of plasma (unincorporated) [3H]adenine by cultured cells was minimized by the addition of unlabeled adenine during the adhesion assay. Scanning electron microscopy, performed in parallel, allowed visual discrimination between platelet adhesion and aggregation as well as morphologic examination of the interacting platelets and cells. After incubation with PRP for 30 min, primary cultures of umbilical vein HEC bound less than 0.05% of added platelets (less than 1 platelet per cell). In contrast, virally transformed HEC showed increased platelet adhesion that was directly proportional to cultured cell density. Visual counts of the number of adherent platelets in scanning electron micrographs showed good agreement with calculated radiometric data. Comparative studies indicated that suspensions of washed, radiolabeled human platelets also can be utilized in this monolayer adhesion assay. This in vitro model system should facilitate study of the mechanisms of thromboresistance of vascular endothelium and its pathophysiologic alterations.

Flavor preferences in malnourished Mexican infants

Taste and flavor preferences were evaluated in malnourished (n=113) and well nourished (n=87) Mexican infants tested between 2 and 24 months of age. Not all infants were tested in all conditions. The malnourished infants all suffered from second or third degree malnutrition (marasmus) and were tested 2-28 days after admission to a renutrition center. Well nourished control infants were tested at their own homes or neighbor's homes. In the first experiment, testing consisted of brief presentations of moderate concentrations of sucrose (sweet), NaCl (salty), citric acid (sour) and urea (bitter). Infants were allowed to ingest as much of the taste substances as they wished. Volume of taste solutions and diluent was determined and provided the data for comparison between groups. In the second experiment, responses to casein hydrolysate and monosodium glutamate solutions were studied with soup serving as the diluent. The preferences of malnourished children for NaCl, citric acid and urea were not substantially different from those of the well nourished group. In sucrose tests, malnourished infants recently admitted to the renutrition center exhibited a decreased response. Malnourished infants ingested more casein hydrolysate and soup solution than soup alone. Control infants tended to respond in the opposite direction. All infants exhibited a preference for soup with MSG relative to plain soup.

Role of heparin therapy in the outcome of adult hemolytic uremic syndrome

Intravenous heparin therapy was associated with complete recovery of renal function in a young woman who developed adult hemolytic uremic syndrome while taking oral contraceptive agents. No controlled study is yet available but a review of an additional 36 reported patients who fulfill adequate criteria for the diagnosis of adult hemolytic uremic syndrome suggests that consideration should be given to a trial of heparin therapy in patients with this syndrome in whom renal biopsy shows recoverable glomeruli in the presence of persistent severe impairment of renal function.