Chronic viral hepatitis C: management update

The management of chronic viral hepatitis C is evolving rapidly. Monotherapy with interferon, the accepted standard of treatment until recently, achieves only a modest sustained virological response rate of 15%. Combination treatment with alpha-2b interferon and ribavirin has been shown to increase sustained response rates to 40% in patients who have never been treated with interferon and to 50% in those who have relapsed following monotherapy with interferon. However, side effects, which have led to the discontinuation of combination treatment in a significant proportion of patients, must be carefully monitored. Treatment with interferon alpha-2b and ribavirin has now been approved in Canada, but the selection and monitoring of patients suitable for combination treatment requires special expertise. Although improvements in current therapeutic options may be possible with more frequent, higher doses or long-acting forms of interferon together with ribavirin, low sustained response rates (i.e., below 30%) for patients with hepatitis C virus genotype 1 emphasize the need for novel antiviral medications that will target the functional sites of the HCV genome.     

Selection on innate immunity and body condition in Florida scrub-jays throughout an epidemic

Opportunities to investigate selection in free-living species during a naturally occurring epidemic are rare; however, we assessed innate immunocompetence in Florida scrub-jays before the population suffered the greatest over-winter mortality in 20 years of study. Propitiously, three months prior to the epidemic, we had sampled a number of male breeders to evaluate a suite of physiological measures that are commonly used to estimate the overall health-state of an individual. There was a significant, positive selection gradient for both Escherichia coli bacterial killing capability and body condition, suggesting that directional selection had occurred upon each of these traits during the disease epidemic.     

Aplasia cutis congenita reminiscent of the lines of Blaschko

A male newborn showing congenital symmetrical abdominal skin defects and an alopecia on the scalp following a spiral pattern is described. The pattern of distribution of both skin anomalies was reminiscent of the lines of Blaschko, indicating that somatic mosaicism is the most probable cause for the defects.     

The development potential of ethanol-induced monosomic and trisomic conceptuses in the mouse

The development potential of fertilized embryos isolated from female mice previously given a single dose of either a dilute solution of ethanol or distilled water (controls) by mouth was studied. Exposure to ethanol occurred at various times during the cycle leading to ovulation and shortly after fertilization. The chromosome constitution of all preimplantation embryos isolated from these females was determined either at the first cleavage mitosis or at the morula stage. The incidence of aneuploidy in the ethanol-exposed groups at these times was approximately 19% and 13.5%, respectively, with a similar number of monosomic and trisomic conceptuses observed at these times. In addition, about 2% of all conceptuses examined were triploid. Further females were autopsied on the 10th or 11th day of gestation, though the chromosome constitution of only the morphologically abnormal or developmentally retarded embryos was determined. Eight embryos out of a total of 16 studied in the ethanol-exposed group were either aneuploid or triploid, whereas in the control group only one out of 11 examined proved to be aneuploid. The triploids and ethanol-induced aneuploid conceptuses appeared to be capable of surviving to the morula stage but generally failed to survive to the 10th/11th day. No monosomics were in fact observed in the postimplantation series. The present findings are briefly discussed with reference to the possible pathogenesis of spontaneous abortions in man, which often possess similar types of chromosomal anomalies.     

Time dependent effect of indomethacin on the stimulation of protein synthesis in isolated rabbit muscle by insulin

Insulin (100 U/ml) stimulated protein synthesis and PGF₂ release in isolated rabbit muscle, but had little effect on the rate of protein degradation. The effect of insulin persisted for at least 5 h after removal of the hormone. Indomethacin, added at the start of the incubation, inhibited the stimulatory effect of insulin on protein synthesis and PGF₂ release, but did not block the binding of iodinated insulin. When added 2 h after insulin, indomethacin did not inhibit the stimulation of protein synthesis but completely inhibited the increase in PGF₂ release. The results suggest that the stimulation of protein synthesis by insulin is mediated by metabolites of membrane phospholipids but that these changes are involved during the phase of response that immediately follows the binding of insulin to its receptor.     

Characterization of an immune suppressor from transformed human trophoblastic JEG-3 cells

Cultured human choriocarcinoma JEG-3 cells secrete an immunosuppressor that inhibits lymphocyte proliferation stimulated by either an antigen or a mitogen. In this study, the immunosuppressive factor was characterized by three methods: ion-exchange and exclusion chromatography, partition in organic solvents, and thin-layer chromatography on silicic acid. This JEG-3 cell factor appeared to be a protein complex of about 150,000–200,000 Da that contained an immunologically active polar lipid. The structural and functional characteristics of JEG-3 cell immunosuppressor are similar if not identical to those of SIF, a suppressor lymphokine derived from T cells. These secretions from transformed trophoblastic cells may correspond to normal placental products or represent a function of malignant cells.