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.     

Development of hatching blastocysts from immature human oocytes following in-vitro maturation and fertilization using a co-culture system

Recently, in-vitro maturation (IVM) of immature human oocytes recovered from non-stimulated follicles has been applied in the treatment of infertility. However, in previous reports, very few embryos cultured in conventional medium have reached the expanded blastocyst stage following in-vitro maturation and fertilization (IVM/IVF). The objective of this study was to investigate whether the developmental competence of human embryos following IVM/IVF could be enhanced by the use of a human ampullary cell co-culture system. Immature human oocytes were aspirated from small follicles at Caesarean section and then cultured in medium containing human menopausal gonadotrophin for 36 to 48 h, followed by insemination. Zygotes were randomly cultured either in conventional culture medium alone or in the co-culture system. Of 48 embryos cultured in conventional medium alone, all arrested at the 2-16- cell stage on day 3 after insemination. Of 46 embryos cultured in the co-culture system, 26 embryos (56.5%) arrested at the 2-16-cell stage. Six embryos (13%) developed to the morula stage. Fourteen embryos (30.4%) developed to expanded blastocysts and two blastocysts were hatching on day 7 after insemination. We conclude that co-culture significantly enhances the development of blastocysts in embryos resulting from IVM/IVF.      

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.     

Identification of stimuli that mediate experience-dependent modification of homosexual courtship inDrosophila melanogaster

A naive, sexually matureD. melanogaster male tested with a young, sexually immature male will perform vigorous courtship, but the mature male will perform much less courtship if he is subsequently tested with a second young male. This phenomenon is called experience-dependent courtship modification (EDCM). We have shown that exposure to either or both of the two courtship-stimulating pheromones that immature males synthesize is sufficient to induce EDCM.     

Interstrain variability of larval photokinesis inDrosophila melanogaster

Larvae from seven laboratory strains and eight isofemale lines ofDrosophila melanogaster differ significantly with regard to their responses to light in a photokinesis assay in which the larvae are tested en masse. Larvae from the CA-2 laboratorystock fail to disperse on assay plates, although observations of individual CA-2 larvae suggest that the larvae are repelled by light. Larvae from all of the other laboratory stocks and all of the isofemale lines (except LI2 and NC5) avoid light in the photokinesis assay. Larvae from some stocks are much more strongly repelled by light than larvae from other stocks. LI2 larvae are unresponsive to light in most replicates of the photokinesis assay, while NC5 larvae are consistently unresponsive to light. Observations of F₁ heterozygotes suggest that the allele(s) that affects the vision of LI2 and NC5 larvae has net effects on the animals' behavior that are partially dominant and recessive, respectively.