Melatonin rhythm and other outputs of the master circadian clock in the desert goat (Capra hircus) are entrained by daily cycles of ambient temperature

In desert areas, mammals such as camel and goat are exposed to harsh environmental conditions. The ambient temperature (Ta) cycles have been shown to entrain the circadian clock in the camel. In the present work, we assumed that, in the goat living in a desert biotope, Ta cycles would have the same synchronizing effect on the central clock. Therefore, the effects of Ta cycles on body temperature (Tb), locomotor activity (LA) and melatonin (Mel) rhythms as outputs of the master circadian clock have been studied. The study was performed on bucks kept first under constant conditions of total darkness (DD) and constant Ta, then maintained under DD conditions but exposed to Ta cycles with heat period during subjective day and cold period during subjective night. Finally, the Ta cycles were reversed with highest temperatures during the subjective night and the lowest temperatures during the subjective day. Under constant conditions, the circadian rhythms of Tb and LA were free running with an endogenous period of 25.3 and 25.0 hours, respectively. Ta cycles entrained the rhythms of Tb and LA to a period of exactly 24.0 hours; while when reversed, the Ta cycles led to an inversion of Tb and LA rhythms. Similarly, Ta cycles were also able to entrain Mel rhythm, by adjusting its secretion to the cooling phase before and after Ta cycles inversion. All together, these results show that the Ta cycles entrain the master circadian clock in the goat.     

An Epidemiological and Clinical Study of Transaminase Levels and Hepatitis B Antibodies in 1,100 Blood Donors

In order to provide epidemiological and clinical information on surrogate testing of blood donations, the respective prevalences of serum hepatitis B virus (HBV) markers and elevated transaminase levels were studied in 1,100 blood donors according to their geographic origin and socioeconomic level. The frequency of serum HBV markers varied as a function of HBV endemicity in the country of origin; however, it was inversely correlated (p less than 0.05) to the socioeconomic level of the donors, even in those originating from countries of low HBV endemicity. There was no association between serum HBV markers and the increased transaminase level which was observed in 48 (4.3%) donors. Twenty-five of these accepted further clinical evaluation. A diagnosis appeared probable in 12 of the 25: alcohol in 5; drugs in 6; non-A, non-B hepatitis in 1. Seven of the remaining 13 subjects were more than 25% above ideal body weight. Transaminase activities determined at the time of clinical assessment were normal in 14. In addition, serum HBV DNA was found in 5 of 247 donors, even in the absence of any usual HBV marker and/or hypertransaminasemia. This could account for the few cases of B and B-like posttransfusion hepatitis which are known to still occur despite careful HBsAg screening of blood donors.     

Lack of evidence for a role of HCV in hepatitis-associated aplastic anaemia

Summary Hepatitis-associated aplastic anaemia (HAAA) is usually related to non-A, non-B hepatitis agents but the prevalence of anti-hepatitis C virus (HCV) antibodies is similar in HAAA and aplasia of other origins according to the results of the ELISA1 assay. This fact could reflect either that HCV is not involved in HAAA or that HAAA-associated defective immune function could yield false negative assays despite on-going HCV infection.
To test these hypotheses, we compared 19 patients with HAAA, including three ELISAl-positive, to 23 patients with aplasia of known and unknown origin, including eight ELISA1-positive. who were matched for age, sex and blood transfusion units. HCV infection was searched for by the second-generation recombinant-immunoblot assay (RIBA2), and by the polymerase chain reaction which detects HCV viraemia. HCV viraemia was detected in four among the 19 patients with HAAA and in six among the 23 patients with aplasia of other causes.
HCV does not clearly appear responsible for hepatitis-associated aplastic anaemia which could be due to non-A. non-B, non-C hepatitis virus. HCV viraemia is frequent in severe aplastic anaemia, even without detectable anti-HCV antibodies, and reflects mainly transfusion-associated HCV infection.     

Hepatitis C viremia and anti-HCV antibodies in alcoholics

We determined serum hepatitis C status using a RIBA2 kit and a sensitive PCR procedure in 62 chronic alcoholics, 36 of whom had anti-HCV antibodies (Ab) detectable in an ELISA1 assay. Anti-HCV antibodies were detected in 22 patients using RIBA2. HCV RNA was detected by means of PCR in 18 patients who were RIBA2 positive and in none who were RIBA2 negative. Liver biopsies, available for 12 HCV RNA-positive patients, revealed histological features of purely alcohol-related lesions in seven and mixed alcohol-viral lesions in five. These results indicate that HCV replication is maintained in most alcoholics who score positive for anti-HCV Ab in the RIBA2 test, and that HCV viremia can be associated with histological features typical of alcoholic liver disease.