Chitosan-Nanoconjugated Hormone Nanoparticles for Sustained Surge of Gonadotropins and Enhanced Reproductive Output in Female Fish

A controlled release delivery system helps to overcome the problem of short life of the leutinizing hormone releasing hormone (LHRH) in blood and avoids use of multiple injections to enhance reproductive efficacy. Chitosan- and chitosan-gold nanoconjugates of salmon LHRH of desired size, dispersity and zeta potential were synthesized and evaluated at half the dose rate against full dose of bare LHRH for their reproductive efficacy in the female fish, Cyprinus carpio. Whereas injections of both the nanoconjugates induced controlled and sustained surge of the hormones with peak (P<0.01) at 24 hrs, surge due to bare LHRH reached its peak at 7 hrs and either remained at plateau or sharply declined thereafter. While the percentage of relative total eggs produced by fish were 130 and 67 per cent higher, that of fertilised eggs were 171 and 88 per cent higher on chitosan- and chitosan-gold nanoconjugates than bare LHRH. Chitosan nanoconjugates had a 13 per cent higher and chitosan gold preparation had a 9 per cent higher fertilization rate than bare LHRH. Histology of the ovaries also attested the pronounced effect of nanoparticles on reproductive output. This is the first report on use of chitosan-conjugated nanodelivery of gonadotropic hormone in fish.     

Fitting and Calibrating a Multilevel Mixed-Effects Stem Taper Model for Maritime Pine in NW Spain

Stem taper data are usually hierarchical (several measurements per tree, and several trees per plot), making application of a multilevel mixed-effects modelling approach essential. However, correlation between trees in the same plot/stand has often been ignored in previous studies. Fitting and calibration of a variable-exponent stem taper function were conducted using data from 420 trees felled in even-aged maritime pine (Pinus pinaster Ait.) stands in NW Spain. In the fitting step, the tree level explained much more variability than the plot level, and therefore calibration at plot level was omitted. Several stem heights were evaluated for measurement of the additional diameter needed for calibration at tree level. Calibration with an additional diameter measured at between 40 and 60% of total tree height showed the greatest improvement in volume and diameter predictions. If additional diameter measurement is not available, the fixed-effects model fitted by the ordinary least squares technique should be used. Finally, we also evaluated how the expansion of parameters with random effects affects the stem taper prediction, as we consider this a key question when applying the mixed-effects modelling approach to taper equations. The results showed that correlation between random effects should be taken into account when assessing the influence of random effects in stem taper prediction.     

The Luteinizing Hormone Surge Regulates Circadian Clock Gene Expression in the Chicken Ovary

The molecular circadian clock mechanism is highly conserved between mammalian and avian species. Avian circadian timing is regulated at multiple oscillatory sites, including the retina, pineal, and hypothalamic suprachiasmatic nucleus (SCN). Based on the authors’ previous studies on the rat ovary, it was hypothesized that ovarian clock timing is regulated by the luteinizing hormone (LH) surge. The authors used the chicken as a model to test this hypothesis, because the timing of the endogenous LH surge is accurately predicted from the time of oviposition. Therefore, tissues can be removed before and after the LH surge, allowing one to determine the effect of LH on specific clock genes. The authors first examined the 24-h expression patterns of the avian circadian clock genes of Bmal1, Cry1, and Per2 in primary oscillatory tissues (hypothalamus and pineal) as well as peripheral tissues (liver and ovary). Second, the authors determined changes in clock gene expression after the endogenous LH surge. Clock genes were rhythmically expressed in each tissue, but LH influenced expression of these clock genes only in the ovary. The data suggest that expression of ovarian circadian clock genes may be influenced by the LH surge in vivo and directly by LH in cultured granulosa cells. LH induced rhythmic expression of Per1 and Bmal1 in arrhythmic, cultured granulosa cells. Furthermore, LH altered the phase and amplitude of clock gene rhythms in serum-shocked granulosa cells. Thus, the LH surge may be a mechanistic link for communicating circadian timing information from the central pacemaker to the ovary. (Author correspondence: stischkau@siumed.edu)     

Detecting Local Haplotype Sharing and Haplotype Association

A novel haplotype association method is presented, and its power is demonstrated. Relying on a statistical model for linkage disequilibrium (LD), the method first infers ancestral haplotypes and their loadings at each marker for each individual. The loadings are then used to quantify local haplotype sharing between individuals at each marker. A statistical model was developed to link the local haplotype sharing and phenotypes to test for association. We devised a novel method to fit the LD model, reducing the complexity from putatively quadratic to linear (in the number of ancestral haplotypes). Therefore, the LD model can be fitted to all study samples simultaneously, and, consequently, our method is applicable to big data sets. Compared to existing haplotype association methods, our method integrated out phase uncertainty, avoided arbitrariness in specifying haplotypes, and had the same number of tests as the single-SNP analysis. We applied our method to data from the Wellcome Trust Case Control Consortium and discovered eight novel associations between seven gene regions and five disease phenotypes. Among these, GRIK4, which encodes a protein that belongs to the glutamate-gated ionic channel family, is strongly associated with both coronary artery disease and rheumatoid arthritis. A software package implementing methods described in this article is freely available at http://www.haplotype.org.     

Detecting Structure of Haplotypes and Local Ancestry

We present a two-layer hidden Markov model to detect the structure of haplotypes for unrelated individuals. This allows us to model two scales of linkage disequilibrium (one within a group of haplotypes and one between groups), thereby taking advantage of rich haplotype information to infer local ancestry of admixed individuals. Our method outperforms competing state-of-the-art methods, particularly for regions of small ancestral track lengths. Applying our method to Mexican samples in HapMap3, we found two regions on chromosomes 6 and 8 that show significant departure of local ancestry from the genome-wide average. A software package implementing the methods described in this article is freely available at http://bcm.edu/cnrc/mcmcmc.     

GnRH-A免疫与母兔生殖激素浓度的变化

目的探讨促性腺激素释放激素类似物（GnRH-A）对动物生殖功能调节的效果和作用机制。方法 24只日本大耳白兔分为四组,分别在实验Ⅰ组（EG-I）、实验Ⅱ组（EG-II）和实验III（EG-III）组兔的颈背侧注射1.0 mL（100、100和50μg/mL）GnRH-A抗原,实验II组和实验III组于第3周以原剂量加强注射一次,用ELISA法测定血清GnRH抗体效价、促卵泡刺激素（FSH）和促黄体生成素（LH）含量。结果注射GnRH-A后10 d实验组兔均出现GnRH抗体,而对照组未检测到;EG-I在第30天达到高峰,而EG-II和EG-III于40～50 d至峰值,但在实验结束时（70 d）实验组均高于对照组,40～70 d时EG-II显著高于EG-I和EG-III。30～50 d时EG-II的LH明显高于EG-I和EG-III及对照组。EG-II和EG-III的FSH浓度在40 d达到峰值,但EG-II高于EG-I、对照组及EG-III,EG-I和对照组无显著差异。结论兔体内注射GnRH-A可以明显提高GnRH抗体效价,增强LH和FSH的合成与分泌,加强注射效果更明显,且与注射剂量相关,持续时间为40 d左右。     

Indirect ELISA with Recombinant GP5 for Detecting Antibodies to Porcine Reproductive and Respiratory Syndrome Virus

Porcine reproductive and respiratory syndrome is caused by the PRRS virus (PRRSV),which has six structural proteins (GP2,GP3,GP4,GP5,M and N). GP5 and N protein are important targets for serological detection by enzyme-linked immunosorbent assay (ELISA) and other methods. Toward this goal,we developed an indirect ELISA with recombinant GP5 antigens and this method was validated by comparison to the LSI PRRSV-Ab ELISA kit. The results indicated that the optimal concentration of coated recombinant antigen was...     

马鹿的圈养种群粪样中性激素水平与繁殖行为的关联

2003年9、10月和2004年4～7月,对黑龙江省兰西县榆林镇禄宝种鹿场圈养的天山马鹿(Cervuselaphus songaricus)进行了行为观察,并利用放射免疫分析法(RIA)测定了马鹿粪样中的性激素水平,包括雄鹿的睾酮.雌鹿的孕酮、雌二醇和雌三醇.结果表明,圈养条件下天山马鹿繁殖行为呈显著的季节变化.雌马鹿性行为的高发期在9月(P＜0.01).在幼仔出生后的6月(高出生月份),嗅仔和舔仔行为显著高于5月和7月(P＜0.05),极显著高于其他月份(P＜0.01);唤仔行为6月份极显著高于其他月份(P＜0.01);哺乳行为发生的高峰期在6、7两个月,而且发生了显著的异常哺乳与异常授乳行为.雄马鹿嗅尿、卷唇、尿喷洒、腺体标记、呜叫与蹄地行为发生频次高发期在9、10月(P＜0.01);饰角发生高峰期在6月,角斗在6月显著高于其他月份;爬胯与搅水或泥浴行为在9、10月显著出现.雄马鹿粪样性激素水平与其繁殖行为呈显著相关;而雌马鹿粪样性激素水平只有孕酮与雌马鹿的部分育幼行为存在显著的相关,与大部分行为不存在显著相关.     

蛋氨酸硒对西门塔尔牛发情周期生殖激素分泌的影响

选用16头18月龄、体况良好、体重(380±24)kg的西门塔尔育成母牛,采用随机区组设计分为4组,以蛋氨酸硒为硒源,研究日粮添加硒(0、0.3、0.6和0.9 mg/kg干物质)对其发情周期生殖激素分泌的影响。结果表明,日粮添加蛋氨酸硒显著提高了发情周期LH、FSH、P4、E2水平,其中添加硒0.3 mg/kg组、0.6 mg/kg组显著高于0.9 mg/kg组和对照组,而0.9 mg/kg组显著高于对照组(P<0.05)。结果表明,以蛋氨酸硒为硒源时,添加硒0.3~0.6 mg/kg对发情周期生殖激素分泌有显著促进作用,以0.6 mg/kg为佳,加上基础日粮含硒量,建议以蛋氨酸硒为硒源时日粮硒水平为0.67 mg/kg干物质。     

A Mixed-Effects Model with Different Strategies for Modeling Volume in Cunninghamia lanceolata Plantations

A systematic evaluation of nonlinear mixed-effect taper models for volume prediction was performed. Of 21 taper equations with fewer than 5 parameters each, the best 4-parameter fixed-effect model according to fitting statistics was then modified by comparing its values for the parameters total height (H), diameter at breast height (DBH), and aboveground height (h) to modeling data. Seven alternative prediction strategies were compared using the best new equation in the absence of calibration data, which is often unavailable in forestry practice. The results of this study suggest that because calibration may sometimes be a realistic option, though it is rarely used in practical applications, one of the best strategies for improving the accuracy of volume prediction is the strategy with 7 calculated total heights of 3, 6 and 9 trees in the largest, smallest and medium-size categories, respectively. We cannot use the average trees or dominant trees for calculating the random parameter for further predictions. The method described here will allow the user to make the best choices of taper type and the best random-effect calculated strategy for each practical application and situation at tree level.     

亚硒酸钠对西门塔尔母牛发情周期生殖激素分泌的影响

选用12头18月龄,体况良好,体重380 kg的西门塔尔牛育成母牛,采用完全随机区组设计分为4组,研究亚硒酸钠(0、0.3、0.6和0.9 mg Se/kg DM)对发情周期外周血清促黄体素、促卵泡素、孕酮和雌二醇分泌的影响。结果表明:日粮添加亚硒酸钠后发情周期促黄体素、促卵泡素、孕酮和雌二醇分泌水平提高,0.3 mg/kg组和0.6 mg/kg组显著高于对照组(P<0.05),0.3 mg/kg组较0.6 mg/kg组高(P>0.05)。根据试验结果推断以亚硒酸钠为硒源,添加0.3 mg Se/kg DM对发情周期生殖激素分泌有显著促进作用,兼顾基础日粮的含硒量,建议日粮硒水平为0.37 mg Se/kg DM。     

Reproductive and Exogenous Hormone Factors in Relation to Risk of Meningioma in Women: A Meta-Analysis

Background and Objective

A number of studies have focused on the association between oral contraceptive (OC), hormonal replacement therapy (HRT) and reproductive factors and meningioma risk, but the results were inconsistent. Thus, a meta-analysis was performed to obtain more precise estimates of risk.

Methods

We conducted a literature search using PubMed and EMBASE databases to July2013, without any limitations. Random effects models were used to summarize results.

Results

Twelve case-control and six cohort studies were included in this meta-analysis. We found that an increased risk of meningioma was associated with HRT use(RR = 1.19, 95% CI = 1.01–1.40), postmenopausal women(RR = 1.32, 95% CI = 1.07–1.64) and parity(RR = 1.18, 95% CI = 1.00–1.40).No significant associations were observed for OC use (RR = 0.93, 95% CI = 0.83–1.03), age at menarche(RR = 1.06, 95% CI = 0.92–1.21), age at menopause(RR = 1.03, 95% CI = 0.81–1.30), or age at first birth(RR = 0.94, 95% CI = 0.80–1.10).

Conclusion

In conclusion, the results of our study support the hypothesis that longer exposure to effect of female sex hormones may increase the risk of meningioma in women, yet additional studies are warranted to confirm our findings and identify the underlying biological mechanisms.     

联合荧光光谱与寿命法检测多次高温加热油

三维荧光光谱法检测多次高温加热植物油,该方法能快速、准确的获得待测样品的三维荧光光谱特征图,但只是定性的分析。当荧光强度变化较小的时候,容易出现误检、漏检的情况。先用三维荧光光谱技术分析植物油样品的光谱信息,然后再通过荧光寿命法,计算多次高温加热植物油中荧光光子的寿命,通过与未加热油荧光寿命的对比,检测多次高温加热植物油。二者联合,进一步提高了检测的准确度,有利于解决误检、漏检的问题,从而为高温加热油的检测提供有力的参考。