Gas-permeable lifecell tissue culture flasks give improved growth of Helicobacter pylori in a liquid medium.

Experiments were conducted to investigate the microaerobic culture of Helicobacter pylori in a liquid medium by using gas-permeable Lifecell tissue culture flasks. Growth in Lifecell tissue culture flasks was 1.2 to 1.6 log units greater than that in glass control bottles. These results were comparable to those reported by the use of gyrated media.     

The characterization and pathological significance of gastric Campylobacter-like organisms in the ferret: a model for chronic gastritis?

Gastric campylobacter-like organisms (CLO) were isolated from gastric tissues removed at sacrifice from 17 mature ferrets; all animals were colonized, but no macroscopic mucosal lesions or histological features of chronic gastritis were seen. The isolates resembled Campylobacter pylori in many cultural and biochemical characteristics, and produced substantial urease activity, but there were sufficient differences from C. pylori to suggest that ferret gastric CLO represents a separate species. Comparison of human C. pylori and ferret gastric CLO may help to elucidate the pathogenicity of the former in patients with gastritis, and the ferret may serve as a useful animal model for the study of C. pylori infection.     

Surgical management of bile duct stones

The biliary surgeon in the 1990s must be familiar with all of the available techniques for the treatment of bile duct stones. Experience and judgment are important in the successful management of the individual patient with intrahepatic or extrahepatic stones. Knowledge of the nonsurgical methods of stone removal is important in the decision-making process. However, the biliary surgeon must resist the temptation to do less than a thorough removal of all stones at the operation lest the patient be subjected to additional procedures, which carry their own risks of morbidity and death. The goal should be to clear the stones from the biliary system with the fewest procedures offering the lowest morbidity and mortality risks to the patient.     

Thymocyte and peripheral blood T lymphocyte subpopulation changes in piglets following in utero infection with porcine reproductive and respiratory syndrome virus

Piglets infected in utero with porcine reproductive and respiratory syndrome virus (PRRSV) are born severely immunocompromised. In this article we more closely examine the effects of in utero PRRSV infection on circulating and thymic T cell populations. Numbers of CD4+, CD8+, and dual-positive lymphocytes were quantitated in circulation and in the thymus during the 2 weeks following birth. At birth we found that the number of circulating lymphocytes was suppressed by 60%. Lymphocyte numbers were also suppressed by 42% at day 7, but by day 14 the number of lymphocytes had rebounded and was actually 47% greater than controls. At birth and day 7, a drop in the number of CD4+ cells could partially explain the suppression we observed, while the rebound in total lymphocyte numbers seen at day 14 was due to a nearly fourfold increase in the number of circulating CD8+ cells. As a result, the normal CD4+:CD8+ ratio of between 1.4 and 2.2 for neonatal pigs was reduced to 0.1-0.5. The thymuses of infected piglets were found to be 50% smaller than those of control pigs and were characterized by cortical involution and severe cortical depletion of thymocytes. Analysis of the population of thymocytes revealed that double-positive thymocytes were suppressed to a greater degree than either single positive subpopulation. In addition, we show that the number of thymocytes undergoing apoptosis was increased twofold in piglets infected with PRRSV. Taken together, these results help explain the dramatic immunosuppression observed in neonatal animals infected in utero with PRRSV.     

Heart rate recorder

We describe the design of an instrument that can acquire and store the average heart rate of a subject over 256 time intervals of predetermined length (1 or 6 min) during normal daily activities. The instrument consists of two units: a portable recorder, worn by the patient, detects and counts heart beats, and stores their average in memory, and a display later retrieves the contents of that memory. C.M.O.S. technology and programmable operational amplifiers resulted in low power consumption (20 mW). The results obtained from this instrument were accurate to about 1 beat/min compared with Holter monitoring and telemetry.     

Mutations in raised Drosophila melanogaster affect experience-dependent aspects of sexual behavior in both sexes

Many aspects of the reproductive behavior of Drosophila melanogaster are modified dramatically by experience and age. Males' courtship of immature males and fertilized females decreases over time. Females' receptivity to copulation, and the behaviors that females perform and elicit, are affected by their age and sexual experience. We show that mutations in a raised stock affect all of these age- and experience-dependent aspects of male and female sexual behavior. Experience has no effect on raised males' courtship of immature males and has opposite effects on raised and wild-type males' courtship of fertilized females. In comparison to controls, raised females become sexually mature at an earlier age, and sexually mature raised virgin females copulate more quickly. Following mating, raised females elicit more courtship and remate faster and more frequently than control females.     

Phosphorylation of a C-SRC-related protein in macrophages activated in vitro with lymphokine

Treatment of proteose peptone elicited peritoneal macrophages from C3H/HeN mice or the macrophage cell line B6MP102 with a T-cell lymphokine preparation induces cytotoxicity for SV3T3 tumor cells. The Triton X-100 (TX-100) insoluble fractions from activated macrophages possessed kinase activity for an endogenous 53 kDa phosphoprotein (pp53) which was markedly greater than extracts from untreated macrophages. Addition of the tyrosine phosphatase inhibitor, Na₃,VO₄ to the cytotoxicity assay also enhanced tumor cell lysis and Na₃VO₄ treated macrophages showed increased phosphorylation of pp53. Moreover, addition of Na₃VO₄ to the cytoskeleton kinase assay enhanced the phosphorylation of pp53 in a dose dependent manner. Pp53 was immunoprecipitated from the in vitro phosphorylated TX-100 insoluble fraction with monoclonal antibody to pp60^v-src. Anti-pp60^v-src also precipitated a 53 and a 60 kDa phosphoprotein from whole cell extracts and from TX-100 cytoskeleton extracts of macrophages phosphorylated as viable intact cells. Addition of a known tyrosine kinase inhibitor, quercetin, to the macrophage cytoskeleton kinase assay inhibited phosphorylation of pp53, and the in vitro phosphorylated pp53 was resistant to 1 N NaOH hydrolysis, indicating phosphorylation of tyrosine residues. Immune complex kinase assays of anti-pp60^c-src precipitated TX-100 insoluble macrophage fractions revealed strong phosphorylation for α-casein which was inhibited by quercetin. These data suggest that macrophage pp53 is a c-src-related gene product that is inducible by stimuli that activate macrophages to cytotoxicity.