Protein phosphatases: properties and role in cellular regulation

Protein phosphorylation is a principal regulatory mechanism in the control of almost all cellular processes. The nature of the protein phosphatases that participate in these reactions has been a subject of controversy. Four enzymes, termed protein phosphatases 1, 2A, 2B, and 2C, account for virtually all of the phosphatase activity toward phosphoproteins involved in controlling glycogen metabolism, glycolysis, gluconeogenesis, fatty acid synthesis, cholesterol synthesis, and protein synthesis. The properties, physiological roles, and mechanisms for regulating the four protein phosphatases are reviewed.     

Dexamethasone‐Induced Eosinopenia is Associated with Lower Progesterone Production in Cattle

Eosinophilic cells accumulate in the capillaries of the bovine Graafian follicle shortly before ovulation and in the early developing corpus luteum (CL). Suppressing the migration of these eosinophilic cells by dexamethasone allowed us to evaluate their possible function in the CL development. Brown Swiss cows (n = 10) were randomly subdivided into two groups (n = 5). Every group was used once as control group and once as experimental group with two oestrous cycles between each treatment. Eighteen hours (h) after oestrus synchronization, dexamethasone or saline was given. Ovulation was induced 24 h later with gonadotropin‐releasing hormone. Another injection of dexamethasone or saline was given 12 h later. Eosinophilic cells in the blood were counted daily until day 7 after the first dexamethasone injection. The collection of ovaries took place at days 1, 2 and 5. Gene expression, protein concentration and location of angiogenic factors, chemokines, insulin‐like growth factor 1 (IGF1) and eosinophilic cells were studied. No eosinophilic cells were found in the CL of the treatment group. Blood progesterone decreased significantly in the dexamethasone group from day 8 to 17. The protein concentration of FGF2 increased significantly in CL tissue at day 2 and VEGFA decreased. Local IGF1 gene expression in the CL was not regulated. We assume from our data that the migration of eosinophilic cells into the early CL is not an essential, but an important stimulus for angiogenesis during early CL development in cattle.     

由麻疹思考小反刍兽疫的问题

小反刍兽疫(Peste des petits ruminants,PPR)是山羊、绵羊等小反刍兽类的急性接触传染性疾病,国际上将小反刍兽疫归为A类传染病.目前除非洲、中东和南亚次大陆传播外,在我国周边地区的许多国家和地区也频繁出现流行.因此,该病作为一种重大的跨国动物疫病,也在开始危害我国西藏和其他地区的动物生产和卫生安全[1-2].     

Long-term survival of four dogs with disseminated Aspergillus terreus infection treated with itraconazole

SUMMARY Four dogs with disseminated aspergillosis caused by Aspergillus terreus were treated with oral itraconazole for 190 to 1095 days. Infection was eliminated in 1 dog. Two dogs were treated for 1000 and 1095 days but were eventually euthanased 572 and 485 days after treatment was stopped. At necropsy both dogs had widespread aspergillosis. The fourth dog was euthanased for other reasons after 190 days of treatment when it was showing a good clinical response although there was radiographic evidence that the disease was progressing.     

Controls on geyser periodicity

Geyser eruption frequency is not constant over time and has been shown to vary with small (相似文献