Melatonin protects the integrity of granulosa cells by reducing oxidative stress in nuclei,mitochondria, and plasma membranes in mice

Melatonin protects luteinized granulosa cells (GCs) from oxidative stress in the follicle during ovulation. However, it is unclear in which cellular components (e.g., nuclei, mitochondria, or plasma membranes) melatonin works as an antioxidant. GCs from immature (3 wks) ICR mice were incubated with hydrogen peroxide (H2O2; 0.01, 0.1, 1, 10 mM) in the presence or absence of melatonin (100 μg/ml) for 2 h. DNA damage was assessed by fluorescence-based immunocytochemistry using specific antibodies for 8-hydroxydeoxyguanosine (8-OHdG), an indicator of oxidative guanine base damage in DNA, and for histone H2AX phosphorylation (γH2AX), a marker of double-strand breaks of DNA. Mitochondrial function was assessed by the fluorescence intensity of MitoTracker Red probes, which diffuse across the membrane and accumulate in mitochondria with active membrane potentials. Lipid peroxidation of plasma membranes was analyzed by measuring hexanoyl-lysine (HEL), a oxidative stress marker for lipid peroxidation. Apoptosis of GCs was assessed by nuclear fragmentation using DAPI staining, and apoptotic activities were evaluated by caspase-3/7 activities. H2O2 treatment significantly increased the fluorescence intensities of 8-OHdG and γH2AX, reduced the intensity of MitoTracker Red in the mitochondria, increased HEL concentrations in GCs, and enhanced the number of apoptotic cells and caspase-3/7 activities. All these changes were significantly decreased by melatonin treatment. Melatonin reduced oxidative stress-induced DNA damage, mitochondrial dysfunction, lipid peroxidation, and apoptosis in GCs, suggesting that melatonin protects GCs by reducing oxidative stress of cellular components including nuclei, mitochondria, and plasma membranes. Melatonin helps to maintain the integrity of GCs as an antioxidant in the preovulatory follicle.     

Immunological study of an attenuated Salmonella Typhimurium expressing ApxIA,ApxIIA, ApxIIIA and OmpA of Actinobacillus pleuropneumoniae in a mouse model

Salmonella Typhimurium strain expressing the Actinobacillus pleuropneumoniae antigens, ApxIA, ApxIIA, ApxIIIA and OmpA, was previously constructed as a vaccine candidate for porcine pleuropneumonia. This strain was a live attenuated (∆lon∆cpxR∆asd)Salmonella as a delivery host and contained a vector containing asd. An immunological study of lymphocyte proliferation, T-lymphocyte subsets and cytokines in the splenocytes of a mouse model was carried out after stimulation with the candidate Salmonella Typhimurium by intranasal inoculation. The splenic lymphocyte proliferation and the levels of IL-4, IL-6 and IL-12 of the inoculated mice were significantly increased, and the T- and B-cell populations were also elevated. Collectively, the candidate may efficiently induce the Th1- and Th2-type immune responses.     

我国红壤区某些主要土类钾的含量、状态以及含钾矿物的转化规律

就一般农业土壤来讲,土壤中钾素的绝大部分是以原生矿物和粘土矿物的状态存在.O.T.Attoe 和 E.Truog^[1]把土壤钾素分为三部分:第一部分是不易为植物所利用的,主要是长石和白云母;第二部分是迟效性钾,包括黑云母和粘土矿物所固定的钾,有90%以上可以被0.5NHCl 所提出,约占土壤全钾量的 1—2%;第三部分是速效性钾,主要的是代换性钾,以及一部分有机钾.在以后的研究文献中,虽然有不断的补充和修改,但是大体上同意这样一个归纳.     

The genesis and classification of soils on wet terraces and moraines in New Zealand

Six soils on glacial outwash terraces and one on moraine are discussed; four are formed partly in loess of unknown age. Evidence of podzolization is apparent in all profiles, but the vertical drainage under very high rainfall is insufficient to remove surplus water. Gley processes appear to dominate, in a perched-water environment.
Podzolic B horizons were identified in the same five profiles following both the Canadian system and that used by the Soil Survey of England and Wales. However, only three of these profiles could be allocated to existing podzolic subgroups in the latter system. Spodic horizons were identified in a different group of five profiles. Differences in classification are discussed with reference to the criteria used and in relation to proposals for revision of the New Zealand Soil Classification.     

热解材料对生物炭理化性质的影响

生物质的热解材料会对其生物炭的物理化学性质产生较大影响,进而影响其田间应用效果。选取四种乔木(橡树、桑树、樟树和松树)、三种草本植物(芦苇、蒿和蕨类)和两种作物秸秆(玉米秆和油菜秆),在同等热解条件下(550 ℃)制备生物炭,对比其理化性质的差异。结果显示,秸秆生物炭的可溶性Cl^-和K⁺含量、EC和CEC均显著高于乔木和草本生物炭,有效磷也呈现类似规律,而可溶性Na⁺、Ca²⁺和Mg²⁺含量以及pH、SO₄^2-、NH₄⁺-N、NO₃^--N等指标在三类生物炭之间无显著差异。乔木生物炭和草本生物炭之间在各个指标上均无显著差异。这表明,从营养元素、CEC和改良酸性土壤的角度来看,秸秆生物炭比乔木和草本生物炭更适合作为土壤改良剂。     

Expression of Glucocorticoid Receptor α and Its Regulation in the Bovine Endometrium: Possible Role in Cyclic Prostaglandin F2α Production

Cortisol (Cr), the most important glucocorticoid (GC), is well known to suppress uterine prostaglandin F2α (PGF) production. However, the details of the regulatory mechanisms controlling the cyclic changes in endometrial PGF production remain unclear. Here we investigated the expression of the GC receptor (GC-Rα), the actions of cortisol throughout the estrous cycle and the regulatory mechanism of GC-Rα in the bovine endometrium. The levels of GC-Rα protein were greater at the mid-luteal stage (Days 8–12) than at the other stages. Cr more strongly suppressed PGF production at the mid-luteal stage than at the follicular stage. GC-Rα expression was increased by progesterone (P4) but decreased by estradiol-17β (E2) in cultured endometrial stromal cells. The overall results suggest that ovarian steroid hormones control the cyclic changes in endometrial PGF production by regulating GC-Rα expression in bovine endometrial stromal cells.     

粳稻发芽期耐碱性的QTL检测

 以粳粳交高产106/长白9号的200个F2:3株系为作图群体,在0.15% Na2CO3溶液碱胁迫下,进行了水稻发芽率及其相对碱害率的鉴定评价,并以SSR标记构建的分子连锁图谱为基础,对水稻发芽率及其相对碱害率进行了数量性状基因座(QTL)检测。结果表明,在F3株系群中水稻发芽率及其相对碱害率均呈单峰接近正态的连续分布。共检测到碱胁迫下与水稻发芽率相关的QTL 7个,对表型变异的贡献率范围为4.05%～12.61%,其中位于第6染色体RM225-RM204区间的qGC 6和位于第9染色体RM219-RM3700区间的qGC 9对表型变异的贡献率分别为12.61%和10.85%。共检测到与水稻发芽率相对碱害率相关的QTL 6个,对表型变异的贡献率为4.82%～28.07%,其中位于第2染色体RM29-RM221区间的qRGC 2、位于第6染色体RM225-RM204区间的qRGC 6 1、位于第9染色体RM219-RM3700区间的qRGC 9和位于第12染色体RM260-RM3226区间的qRGC 12对表型变异的贡献率较大,分别为28.07％、15.35％、15.61％和18.91％,为主效QTL,但其相应的区间距离均较远,需要进一步深入研究。所检测的QTL增效等位基因主要表现为部分显性和超显性。