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We previously reported that administration of a streptococcal preparation (OK432) inhibited insulitis and development of autoimmune diabetes in nonobese diabetic (NOD) mice and BB rats as animal models of insulin-dependent diabetes mellitus. In this study, we screened various cytokines that could be induced by OK432 in vivo, for their preventive effect against diabetes in NOD mice. Among recombinant mouse IFN'y, human ILla, human IL2, mouse granulocyte-macrophage colony-stimulating factor and human TNFa, only human TNFa suppressed insulitis and significantly (P < 0.001) inhibited development of diabetes. NOD mice were the lowest producers of the mRNA of TNF and serum TNF on stimulation with OK432 or with IFNy plus LPS, compared with C57BL/6, C3H/He, and Balb/c mice. The results imply a role for low productivity of TNF in the pathogenesis of autoimmune diabetes in NOD mice. IntroductionDiabetes develops spontaneously in the nonobese diabetic

Dark anaerobic fermentation in the green algae Chiamydomonas MGA 161, Chlamydomonas reinhardtii, Chlorella pyrenoidosa, and Chlorococcum minutum was studied. Our isolate, Chiamydomonas MGA 161, was unusual in having high H2 but almost no formate. The fermentation pattern in Chlamydomonas MGA 161 was altered by changes in the NaCI or NHI-CI concentration. Glycerol formation increased at low (0.1%) and high (7%) NaCI concentrations; starch degradation, and formation of ethanol, H2, and CO2 increased with the addition of NH4CI to above 5 millimolar in N-deficient cells. C. reinhardtii and C. pyrenoidosa exhibited a very similar anaerobic metabolism, forming formate, acetate and ethanol in a ratio of about 2:2:1. C. minutum was also unusual in forming acetate, glycerol, and CO2 as its main products, with H2, formate, and ethanol being formed in negligible amounts. In the presence of CO, ethanol formation increased twofold in Chiamydomonas MGA 161 and C. reinhardtii, but the fermentation pattern in C. minutum did not change. An experiment with hypophosphite addition showed that dark H2 evolution of the Escherichia coli type could be ruled out in Chiamydomonas MGA 161 and C. reinhardtii. Among the green algae investigated, three fermentation types were identified by the distribution pattern of the end products, which reflected the consumption mode of reducing equivalents in the cells.Green algae produce hydrogen under dark anaerobic conditions, as first observed by Gaffron and Rubin (8). The whole process of dark H2 evolution is mediated through the fermentative degradation of accumulated starch. Use of this property in a stable biophotolysis system makes possible temporal separation of H2 production from photosynthetic 02 production. Lightdependent H2 production without an O2 defense system soon comes to a stop because of inhibition by the O2 produced (10, 28). Studies with a freshwater alga, Chlamydomonas reinhardtii, showed an intermittent but stable 02/H2 production system in an alternating light/dark cycle (24,25). A halotolerant green alga, Chlamydomonas MGA 161, has been isolated, and both growth and dark H2 evolution in this alga are active (26 ucts of green algae (9,17,19). Klein and Betz (16) reported on the fermentation metabolism with no formate formation in Chlamydomonas moewusii. Gfeller and Gibbs (9) and Kreuzberg (19) reported that formate, acetate, and ethanol are produced in a ratio of 2:1:1 in the dark incubation of C. reinhardtii. The fermentation process is regulated by ATP and reducing equivalents generated during starch degradation. The ATP concentration within Chlorella cells increases slightly with active hydrogenase under dark anaerobic conditions, accompanied by an increase in NADH and a decrease in NADPH (22). Reducing equivalents are consumed by the formation of fermentation products for a constant metabolic flux; the reducing power is used for the formation of H2 (from H+), formate (from C02), glycerol (from acetonephosphate) or ethanol (from acetyl-CoA) (17).In this paper, we rep...

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We examine effects of entering the labor market during a recession on subsequent earnings and employment for Japanese and American men, using comparable household labor force surveys. Previous analyses focus on search theoretic and implicit-contract arguments, which have their strongest effects on more educated workers. We argue that, in a country like Japan which has a dual labor market, there is an additional mechanism that affects mainly less educated workers. Namely, these workers are more likely to be trapped in the secondary sector if they graduate during a recession. We find a persistent, strong negative effect on earnings for less educated Japanese men, in contrast to no long-term effect for less educated American men; also, a substantial part of the effect for less educated Japanese men is attributed to the decreased probability of regular employment. The effect for the more educated group is more or less similar in both countries.