Effect of glucose and pyruvate on nuclear and cytoplasmic maturation of porcine oocytes in a chemically defined medium

The objective was to examine potential roles of glucose and pyruvate in nuclear and cytoplasmic maturation of porcine oocytes. Oocyte-cumulus complexes (OCC), derived from 3 to 6 mm follicles, were cultured in a chemically defined medium (pyruvate-free mNCSU37-PVA), with or without 5.55 mM glucose, during in vitro maturation (IVM); in the absence of glucose, germinal vesicle breakdown (GVBD) and nuclear maturation were prevented (P &#60; 0.05). Subsequently, OCC were cultured for IVM in glucose-containing mNCSU37-PVA supplemented with 6-amononicotinamide (6-AN) and diphenyleneiodonium (DPI), inhibitors of the pentose phosphate pathway (PPP); both compounds (&#62;= 10 mu M 6-AN and &#62;= 10 nM DPI) inhibited resumption of meiosis (P &#60; 0.05). Supplementation of glucose-free maturation medium with increasing concentrations of pyruvate induced resumption of meiosis and increased the incidence of oocytes reaching metaphase-II in a concentration-dependent manner (P &#60; 0.05). More mature oocytes were obtained in the presence of pyruvate + glucose (P &#60; 0.05). After culture to allow maturation, glutathione content was higher in oocytes cultured in the presence of pyruvate alone than in those cultured in glucose alone; inclusion of 6-AN abolished responses to pyruvate (P &#60; 0.05). In conclusion, both glucose and pyruvate played a critical role in the release of porcine oocytes from arrest at the GV-I stage, probably through the PPP, whereas supplementation with pyruvate improved cytoplasmic maturation, as determined by oocyte glutathione content.</p

里山に生育する植物種のフェノロジーを基にした生物学的季節区分

Seasons are important factors for the activities of organisms, and biological seasons are one of the key factors for in situ studies of wild organisms. In this research, we determined biological seasons based on phenological pattern of local flora. We defined the study areas of 1km × 1km in rural Tokyo, Japan （under warm-temperate climate）, and the random number was used to extract study plant species from the local flora including herbs and woody species. Both reproductive and vegetative activities were studied （presence of leaves, flowers, and fruits）, and we used multivariate analyses to divide biological seasons. Five biological seasons were detected by a cluster analysis （TWINSPAN）; those were biological winter （season I, December to February）, biological early spring （season II, March）, biological spring （season III, April to early June）, biological summer （season IV, late June to early August） and biological autumn （season V, late August to November）. There were more number of biological seasons in the duration from the coldest to the warmest periods （biological spring and biological early summer）, than the duration from the warmest to the coldest periods （biological autumn）. Temperature was the key environment factor determining biological seasons around the cold period, but day length was the key between biological summer and biological autumn

Drug retention rates and relevant risk factors for drug discontinuation due to adverse events in rheumatoid arthritis patients receiving anticytokine therapy with different target molecules

Objective: To compare reasons for discontinuation and drug retention rates per reason among anticytokine therapies, infliximab, etanercept and tocilizumab, and the risk of discontinuation of biological agents due to adverse events (AE) in patients with rheumatoid arthritis (RA). Method: This prospective cohort study included Japanese RA patients who started infliximab (n=412, 636.0 patientyears (PY)), etanercept (n=442, 765.3 PY), or tocilizumab (n=168, 206.5 PY) as the first biological therapy after their enrolment in the Registry of Japanese Rheumatoid Arthritis Patients for Long-term Safety (REAL) database. Drug retention rates were calculated using the Kaplan-Meier method. To compare risks of drug discontinuation due to AE for patients treated with these biological agents, the Cox proportional hazard model was applied. Results: The authors found significant differences among the three therapeutic groups in demography, clinical status, comorbidities and usage of concomitant drugs. Development of AE was the most frequent reason for discontinuation of biological agents in the etanercept and tocilizumab groups, and the second most frequent reason in the infliximab group. Discontinuation due to good control was observed most frequently in the infliximab group. Compared with etanercept, the use of infliximab (HR 1.69; 95% CI 1.14 to 2.51) and tocilizumab (HR 1.98; 95% CI 1.04 to 3.76) was significantly associated with a higher risk of discontinuation of biological agents due to AE. Conclusions: Reasons for discontinuation are significantly different among biological agents. The use of infliximab and tocilizumab was significantly associated with treatment discontinuation due to AE compared with etanercept