乳酸菌的降血糖作用研究进展

目前乳酸菌的防治糖尿病功效已得到广泛认可.本文综述国内外关于乳酸菌应用于临床糖尿病治疗的研究进展,对乳酸菌可能的降血糖作用机理及物质基础进行了分析总结,并对目前存在的安全性问题和今后研究方向进行探讨,希望为糖尿病防治提供新的思路,为开发新型降糖药物提供一定的理论依据.     

乳酸菌与阴道疾病关系的研究进展

乳酸菌是阴道菌群中的优势菌群,能够分解糖原产生乳酸、过氧化氢及多种抗微生物因子,可从多方面调节阴道内需氧菌和厌氧菌的比例,维持着阴道内的菌群平衡。当这种平衡被其他各种因素打破时,便会引起阴道疾病,通过补充活性乳酸菌可以达到对阴道疾病的预防和治疗。本研究概述了六类常见的阴道疾病,并对近年来乳酸菌治疗此类疾病的机制极其研究进展进行了阐述。     

乳酸菌降低血清胆固醇的研究

本文综述了乳酸菌对血清胆固醇的降低作用,并对其作用机制进行了探讨,这将有助于对乳酸菌资源的进一步开发和利用。     

奶牛阴道菌群分析与乳酸菌的分离及鉴定

目的研究奶牛阴道菌群,并从健康奶牛阴道分离出产酸能力很强的乳酸菌。方法采用常规的方法对奶牛阴道进行细菌的分离及鉴定,并进行菌群分析。结果健康奶牛阴道优势菌群主要为乳酸菌(P<0.01),屡配不孕奶牛阴道优势菌群主要为金黄色葡萄球菌(P<0.01);从健康奶牛阴道分离出的乳酸菌为55株,其中产酸能力很强的6株乳酸菌鉴定结果分别为Lactobacillus plantarum、Lactobacillus brevis、Enterococcus faecalis、Lactococcus garvieae、Lactobacillus kitasatonis和Lactobacillus amylovorus。结论奶牛阴道菌群中分离的6株乳酸菌可作为潜在的奶牛阴道微生态制剂进行深入研究。     

乳酸菌降胆固醇作用研究现状

本文综述了国内外关于乳酸菌在体内及体外降低胆固醇的研究进展, 并对乳酸菌降胆固醇的作用机制进行了探讨, 提出目前在研究中存在的一些问题, 以期对乳酸菌的进一步开发和利用提供帮助。     

奶牛源乳酸菌的分离、鉴定及其微生态制剂的研究

为筛选出能用于防治奶牛子宫内膜炎的益生性乳酸菌菌株并以其为原材料制作微生态制剂,采集产后30～50 d健康奶牛的子宫颈口处分泌物,利用MRS选择性培养基厌氧培养方式进行乳酸菌初步筛选。纯化得到的单株菌株进行染色和镜检,将典型的乳酸菌进行生化鉴定。提取其DNA,扩增16S rDNA全序列并测序,将所得序列与NCBI核酸数据库进行同源性比对,明确各分离菌株种属归属。将鉴定得到的单株乳酸菌过滤以及离心获取上清,得到的上清进行抑菌实验。采用琼脂扩散法检测对大肠埃希菌的抑菌活性。以得到的良好抑菌能力的菌株为原材料进行混合抑菌,进行微生态制剂最优比例的探究,并研究这些菌株的生长曲线和产酸能力。结果显示,经染色镜检、生化鉴定和16S rDNA测序分析和单株抑菌实验得到6株较好的抑菌能力的乳酸菌,其中鼠李糖乳杆菌、魏斯式细菌和粪肠球菌的混合上清抑菌效果最好,具有较强的生长和产酸能力。研究得到了可用于防治奶牛子宫内膜炎益生菌株,可进一步用于临床试验探究。     

乳酸菌促生长因子的研究

乳酸菌属于肠道内的有益菌,对调节人体健康有益,其生长能力和活性受外界条件的影响.促生长因子是一类对微生物生长繁殖具有促进作用的物质,可用于有效提高乳酸菌数量和活性.围绕乳酸菌促生长因子与益生元的关系及其来源、类别和作用机理等方面,综述其在乳酸菌上的研究与应用,并对未来发展方向进行了展望,以期为促生长因子在乳酸菌产业中的...     

具有降胆固醇作用乳酸菌的研究和开发进展

本文综述了国内外关于具有降胆固醇作用的乳酸菌的降胆固醇作用和作用机制的研究进展,同时总结了降胆固醇乳酸菌在食品发酵和医疗保健方面的应用,提出以后研究的重点,以期对乳酸菌的进一步开发和利用提供帮助。     

乳酸菌耐药性的研究进展

乳酸菌(Lactic acid bacteria,LAB)是一种革兰阳性菌,其发酵产物主要是乳酸。根据乳酸菌种系进化过程中形成的不同生化指标可以分为:低GC含量的一群,例如,肠球菌属(En-terococcus),乳酸杆菌属(Lactobacillus),乳酸球菌属(Lactococ-cus),明串珠菌属(Leuconostoc),足球菌属(Pedio     

GPER在女性生殖系统疾病中的研究进展

G蛋白偶联雌激素受体(G protein-coupled estrogen receptor, GPER)是一种与经典雌激素受体(estrogenreceptor,ER)不同的新型雌激素受体,越来越多的证据表明GPER与某些女性生殖系统的疾病密切相关,可能成为疾病治疗的新靶点。本文介绍了GPER在细胞中的定位及其在生殖系统不同部位的表达、GPER的特异性配体,总结了其作用的可能信号通路,并就GPER在生殖生理及病理、妇科肿瘤、绝经后相关疾病、子宫内膜异位性疾病中的作用机制进行了详细的阐述,以期进一步理解GPER在女性生殖系统疾病防治中的作用。     

Economic consequences of reproductive performance in dairy cattle

The net economic value of reproductive efficiency in dairy cattle was estimated using a stochastic dynamic simulation model. The objective was to compare the economic consequences of reproductive performance scenarios (“average” and “poor”) of a cow having a good reproductive performance and to explore which reproductive factors have an important impact on economic efficiency. A “good” reproductive performance scenario was defined with 1 ovulation rate (POVU_i), 0.7 estrus detection rate (PEst), 0.7 conception rate (PCon), 0.03 incidence rate of postpartum disorders prolonging the ovarian cyclicity (CO), 0.2 incidence rate of postpartum disorders reducing conception (ME), 0.05 embryonic death rate (ED), and voluntary waiting period (VWP) of 9 wks pp (post partum). In the current situation of dairy cows in the Netherlands, an “average” reproductive scenario (0.95 POVU_i, 0.5 PEst, 0.5 Pcon, 0.07 CO, 0.27 ME, 0.07 ED and VWP of 12 wks pp) and a “poor” reproductive scenario (0.90 POVU_i, 0.3 PEst, 0.3 Pcon, 0.11 CO, 0.33 ME, 0.09 ED and VWP of 15 wks pp) were identified. A sensitivity analysis was performed by comparing changes of single effect of factors in a good and poor scenario with the average scenario. The mean net economic loss (NEL_i) compared with the good scenario was €34 and €231 per cow per year for the average and poor reproductive performance scenario, respectively. Increasing the calving interval resulted in greater economic loss. The important factors on the cost of reproductive efficiency were the involuntary culling cost and the return of milk production. Variation in PCon, PEst, ME, ED, and VWP had large impacts on economic benefits.     

Role of m6A modification in female infertility and reproductive system diseases

Gamete abnormalities and reproductive system tumors have become a dominant cause of infertility, troubling people globally. In recent years, increasing evidence emerged and found that N6-methyladenosine (m6A) played a leading role in reproduction. The biological effects of m6A modification are dynamically and reversibly regulated by methyltransferases (writers), WTAP, METTL3, METTL14 and KIAA1429, demethylases (erasers), FTO and ALKBH5, and m6A binding proteins (readers), including YTH domain. In this review, we highlight the change of m6A modification in abnormal oogenesis, female reproductive system diseases including reproductive system tumors, adenomyosis, endometriosis, premature ovarian failure and polycystic ovary syndrome. Moreover, we review some of the mechanisms and the specific modified genes that have been identified. Especially, with the underlying mechanisms being uncovered, m6A and its protein machineries are expected to be the markers and targets for the diagnosis and treatment of female reproductive dysfunction.     

植物非叶绿色器官光合贡献研究进展

植物光合作用是生物界赖以生存的基础.长期以来,叶片被认为是植物进行光合作用的重要器官.然而在逆境条件下,植物非叶绿色器官的光合贡献也具有巨大的潜力.近年来,为了探究植物增产的新途径,科研工作者纷纷把目光投向了植物非叶绿色器官.本文简述了植物非叶绿色器官中能够进行光合作用的器官类型、非叶绿色器官光合贡献率及其光合贡献率的...     

Understanding the reproductive performance of a dairy cattle herd by using both analytical and systemic approaches: a case study based on a system experiment

Reproductive performance has recently been a growing concern in cattle dairy systems, but few research methodologies are available to address it as a complex problem in a livestock farming system. The aim of this paper is to propose a methodology that combines both systemic and analytical approaches in order to better understand and improve reproductive performance in a cattle dairy system. The first phase of our methodology consists in a systemic approach to build the terms of the problem. It results in formalising a set of potential risk factors relevant for the particular system under consideration. The second phase is based on an analytical approach that involves both analysing the shapes of the individual lactation curves and carrying out logistic regression procedures to study the links between reproductive performance and the previously identified potential risk factors. It makes it possible to formulate hypotheses about the biotechnical phenomena underpinning reproductive performance. The last phase is another systemic approach that aims at suggesting new practices to improve the situation. It pays particular attention to the consistency of those suggestions with the farmer's general objectives. This methodology was applied to a French system experiment based on an organic low-input grazing system. It finally suggested to slightly modify the dates of the breeding period so as to improve reproductive performance. The formulated hypotheses leading to this suggestion involved both the breed (Holstein or Montbéliarde cows), the parity, the year and the calving date with regard to the turnout date as the identified risk factors of impaired performance. Possible use of such a methodology in any commercial farm encountering a biotechnical problem is discussed.     

乳酸杆菌S-层蛋白的特性及功能性研究进展

文章综述了S-层蛋白的性质和功能,重点介绍了S-层蛋白对乳酸杆菌表面性质和黏附性的影响以及调节肠道功能的作用,包括减少病原菌引起的细胞凋亡、调节免疫细胞的活性、与SIGNR3相互作用参与肠道免疫反应、通过TLRS-My D88-NF-κB途径发挥生物学功能以及调控肠道黏膜相关蛋白表达。由此证明了S-层蛋白对于乳酸杆菌发挥免疫调节功能具有重要的作用。     

Effects of cubicle characteristics on animal welfare indicators in dairy cattle

Cubicle characteristics such as cubicle dimensions or management factors such as cow-to-cubicle ratio could affect health and behaviour of dairy cows. The objective of this study was to estimate effects of cubicle characteristics on animal welfare indicators in dairy cattle. A total of 64 loose housing farms in Germany were assessed once during the winter housing period by one experienced assessor. Nearly 15% of the dairy cows had access to pasture during summer months for <6 h/day, whereas 85% were zero-grazing farms. Selected animal welfare indicators (duration of the lying down process, collisions of cows with cubicles, cows lying outside cubicles, cow cleanliness, integument alterations, lameness and subclinical mastitis incidence) of the Welfare Quality® protocol and cubicle characteristics such as cow-to-cubicle ratio and cubicle dimensions were recorded. Data were statistically analysed using a multiple linear regression approach. Pasture access and cubicle type were considered as potential influencing factors. Wider cubicles positively affected the proportion of dairy cows with dirty flanks (−18.5% per 10 cm increase) but increased the number of cows with severe integument alterations (+8.9% per 10 cm increase). Larger lying areas reduced the percentage of cows with dirty udders (−2.9% per 10 cm² increase). Longer distances from neck rail to curb were associated with higher prevalence of cows with dirty flanks (+3.1% per 10 cm increase) and subclinical mastitis incidence (+1.2% per 10 cm increase). With increasing neck rail height, the duration of the lying down process (−0.1 s per 10% increase), the percentages of cows with dirty legs (−8.4% per 10 cm increase), dirty udders (−7.0% per 10 cm increase) and severe lameness (−3.0% per 10 cm increase) decreased. Compared with rubber mat-equipped cubicles, deep-bedded cubicles showed a reduction in the lying down duration (−0.8 s), percentages of cows with dirty legs (−34.2%), dirty udders (−30.5%) and lesions and swellings (−13.1%). Compared with farms that did not provide any summer grazing, pasture access was associated with an increase of cows with severe lameness (+5.6%). Contrastingly, the number of cows with subclinical mastitis incidence was lower when cows had access to pasture in summer (−5.4%). Findings of the present study indicate several associations between cubicle characteristics and animal welfare in dairy cattle. Bedding type was found as the most influencing factor in terms of health and behaviour. Results of this study are valuable for farmers to identify the optimal cubicle design and improve the animal welfare level.     

表观遗传生物标志物在人类疾病早期诊治中的研究进展

表观遗传修饰异常见于人类的多种疾病(如肿瘤、老年性疾病、发育源性疾病等),影响着这些疾病的发生发展。已有的研究表明,异常表观遗传改变可以作为疾病状态和疾病预测的生物标志物。表观遗传修饰改变的可逆性和可控性也为疾病早期的预防和治疗提供了新策略。本文对DNA甲基化修饰、组蛋白共价修饰、非编码RNA等三种表观遗传方式在肿瘤、老年性疾病和发育源性疾病的研究,以及三者作为表遗传生物标志物在疾病早期诊断和治疗的应用展开介绍,以期为肿瘤、老年性和发育源性相关疾病的诊断与治疗提供借鉴和 参考。