• 【与已建立的人子宫内膜上皮和基质细胞系共培养对精子运动特性的影响。】 复制标题 收藏 收藏
    DOI:10.1093/humrep/12.6.1197 复制DOI
    作者列表:Guerin JF,Merviel P,Plachot M
    BACKGROUND & AIMS: The effects of co-culture of human spermatozoa with human immortalized endometrial cells - epithelial or stromal - on sperm movement characteristics, including hyperactivation, were studied using computer-assisted sperm analysis (CASA). Epithelial and stromal cell types could be separated following 8-10 days of culture of endometrial cells originating from human biopsies. Both cell types were immortalized by the SV 40 large T antigen. Co-incubation of sperm with epithelial and stromal monolayers enhanced the rate of hyperactivation24.9% (P <0.05) and 17.8% (P = 0.05) versus 9.5% as control, respectively, whereas the majority of motility parameters remained unchanged. Conditioned media had no effect upon sperm parameters, including hyperactivation. Co-incubation with either monolayer was able to maintain sperm motility over a longer period than incubation in control medium alone.

    In four patients whose spermatozoa did not exhibit hyperactivation, co-incubation with epithelial cells, but not conditioned medium, allowed normal rates of hyperactivation (range6.9-15.6%).

    背景与目标: 使用计算机辅助精子分析 (CASA) 研究了人类精子与人类永生化的子宫内膜细胞 (上皮或基质) 共培养对精子运动特征 (包括过度活化) 的影响。在培养源自人活检的子宫内膜细胞8-10天后,可以分离上皮和基质细胞类型。两种细胞类型都被SV 40大T抗原永生化。与9.5% 对照相比,将精子与上皮和基质单层共同孵育可分别提高高激活率24.9% (P <0.05) 和17.8% (P = 0.05),而大多数运动参数保持不变。条件培养基对精子参数 (包括过度活化) 没有影响。与单独在对照培养基中孵育相比,与任一单层共同孵育能够在更长的时间内保持精子活力。
    在四名精子未表现出过度活化的患者中,与上皮细胞共同孵育,但不是条件培养基,允许正常的过度激活率 (范围6.9-15.6%)。
  • 【NIDCR R25赠款支持对研究型非密集型牙科学校的课程和文化的影响。】 复制标题 收藏 收藏
    DOI:10.1177/154405910708600701 复制DOI
    作者列表:Iacopino AM,Pryor ME,Taft TB,Lynch DP
    BACKGROUND & AIMS: :Our objective was to evaluate changes in curriculum and culture within a research non-intensive dental school after implementation of programs supported by the NIH-NIDCR R25 Oral Health Research Curriculum Grant. We designed new curricular elements to foster an appreciation of research/discovery, an interest in academic/research careers, and application of biomedical/clinical advances to patient care. Funding was utilized to develop, implement, and assess a dedicated curricular track of continuous student research/scholarly activity throughout the four years of dental education. This track represented mandatory hours of didactic time exposing students to topics not traditionally included in dental curricula. Additionally, students were provided with customized flexible schedules to participate in elective "hands-on" mentored research/scholarly experiences at local, national, and international sites, including linkages to certificate, MS, and PhD programs. Funding was also used to support a wide array of faculty development activities that provided skill sets required to deliver integrated biomedical/clinical content, research-oriented evidence-based approaches to dental education, and translational case-based teaching methods emphasizing the application of new science/technologies to patient care. We measured changes in student, faculty, and institutional profiles/attitudes using traditional benchmarks, surveys, and focus groups. Comparisons were made between baseline data prior to R25 program initiation and data collected after years 3-4 of program implementation. Significant increases were demonstrated in: (1) student participation in research/scholarship, attendance at national meetings, research awards, publication of manuscripts, pursuit of advanced training/degrees, and expressions of interest in academic/research careers; (2) faculty participation in development activities, publication of manuscripts, and mentoring of students; and (3) increased institutional credibility within the university, supportive infrastructure for research/scholarship, and cultural expectations for academic excellence. Thus, we believe that the R25 programming changed the culture of our dental school, creating a supportive environment for research/scholarship, increasing academic productivity, and altering the attitudes of faculty/students.
    背景与目标: : 我们的目标是在实施nih-nidcr R25口腔健康研究课程补助金支持的计划后,评估非密集型牙科学校课程和文化的变化。我们设计了新的课程元素,以促进对研究/发现的欣赏,对学术/研究职业的兴趣以及将生物医学/临床进展应用于患者护理。在整个牙科教育的四年中,资金用于开发,实施和评估持续的学生研究/学术活动的专用课程。此曲目代表了强制性的教学时间,使学生接触传统上不包括在牙科课程中的主题。此外,还为学生提供了定制的灵活时间表,以参加在本地,国家和国际站点上进行的选修 “动手” 指导的研究/学术经验,包括与证书,MS和博士学位课程的联系。资金还用于支持广泛的教师发展活动,这些活动提供了提供综合生物医学/临床内容所需的技能,以研究为基础的基于证据的牙科教育方法以及强调应用新的案例的基于案例的教学方法。科学/技术用于患者护理。我们使用传统的基准,调查和焦点小组来衡量学生,教师和机构概况/态度的变化。比较了R25计划启动前的基线数据和计划实施3-4年后收集的数据。显着增加的表现是 :( 1) 学生参与研究/奖学金,参加国家会议,研究奖,手稿的出版,追求高级培训/学位以及对学术/研究职业的兴趣表达; (2) 教师参与发展活动,手稿的出版,和指导学生; (3) 提高大学内部的机构信誉,支持研究/奖学金的基础设施以及对学术卓越的文化期望。因此,我们认为,R25编程改变了我们牙科学校的文化,为研究/奖学金创造了支持环境,提高了学术生产力,并改变了教师/学生的态度。
  • 【培养中的胎鼠肺泡II型细胞表达体内发现的几种II型细胞特征,以及主要的组织相容性抗原。】 复制标题 收藏 收藏
    DOI:10.1165/ajrcmb/3.4.325 复制DOI
    作者列表:Oomen LC,Ten Have-Opbroek AA,Hageman PC,Oudshoorn-Snoek M,Egberts J,van der Valk MA,Calafat J,Demant P
    BACKGROUND & AIMS: :Alveolar type II cells were isolated from fetal mouse lung by differential adherence and obtained in monolayer culture. Cultures display a high degree of purity as shown by histochemical and immunocytochemical staining procedures. Seventy-five percent of cells stained positive with specific anti-lavage serum mouse (SALS-M), an antiserum specific for (pre)alveolar type II cells of the mouse, and osmiophilic bodies were present in 82% of cells. These and other characteristics of type II cells in culture correspond to those of alveolar type II cells in fetal mouse lung. The pattern of reactivity of these cells with various anti-cytokeratin antibodies is described, and we show that, in contrast to rat type II cells, they do not exhibit alkaline phosphatase activity. Identity of the type II cell cultures was shown by their specific phospholipid composition and surfactant protein A (SP-A) content. The fetal alveolar type II cells in culture were found to synthesize and express class I but not class II major histocompatibility complex (MHC) antigens. The possibility to culture fetal alveolar type II cells of the mouse and the availability of genetically well-defined inbred and transgenic mouse strains opens ways to study the genetics of type II cell differentiation and function. Also, the in vitro availability of alveolar type II cells, the progenitor cells of mouse lung tumors, will enable us to study in vitro several of the processes involved in lung tumorigenesis in the mouse.
    背景与目标: : 通过差异粘附从胎鼠肺中分离出II型肺泡细胞,并在单层培养中获得。如组织化学和免疫细胞化学染色程序所示,培养物显示出高度的纯度。用特异性抗灌洗液血清小鼠 (sars-M) 染色阳性的5% 个细胞,该血清对小鼠的 (前) 肺泡II型细胞具有特异性的抗血清,和嗜渗体体存在于细胞82% 中。培养的II型细胞的这些和其他特征对应于胎鼠肺中II型肺泡细胞的那些特征。描述了这些细胞与各种抗细胞角蛋白抗体的反应性模式,并且我们表明,与大鼠II型细胞相反,它们不显示碱性磷酸酶活性。II型细胞培养物的身份通过其特定的磷脂组成和表面活性剂蛋白A (sp-a) 含量显示。发现培养物中的胎儿肺泡II型细胞合成并表达I类但不表达II类主要组织相容性复合物 (MHC) 抗原培养小鼠胎儿肺泡II型细胞的可能性以及遗传明确的近交和转基因小鼠品系的可用性为研究II型细胞分化和功能的遗传学开辟了途径。此外,肺泡II型细胞 (小鼠肺肿瘤的祖细胞) 的体外可用性将使我们能够在体外研究与小鼠肺肿瘤发生有关的几个过程。
  • 【pH是通过激活ERK1/2途径控制培养中少突胶质细胞前体分化的细胞内效应子。】 复制标题 收藏 收藏
    DOI:10.1002/jnr.21051 复制DOI
    作者列表:Bernard F,Vanhoutte P,Bennasroune A,Labourdette G,Perraut M,Aunis D,Gaillard S
    BACKGROUND & AIMS: :We reported previously that onset of oligodendrocyte precursor cell (OPC) differentiation is accompanied by an increase in intracellular pH (pH(i)). We show that OPC differentiation is dependent primarily on a permissive pH(i) value. The highest differentiation levels were observed for pH(i) values around 7.15 and inhibition of differentiation was observed at slightly more acidic or alkaline values. Clamping the pH(i) of OPCs at 7.15 caused a transient activation of ERK1/2 that was not observed at more acidic or alkaline values. Furthermore, inhibition of ERK activation with the UO126 compound totally prevented OPC differentiation in response to pH(i) shift. These results indicate that pH(i), acting through the ERK1/2 pathway, is a key determinant for oligodendrocyte differentiation. We also show that this pH(i) pathway is involved in the process of retinoic acid-induced OPC differentiation.
    背景与目标: : 我们以前曾报道过少突胶质细胞前体细胞 (OPC) 分化的开始伴随着细胞内pH(i)) 的增加。我们表明OPC的分化主要取决于允许的pH(i) 值。对于7.15附近的pH(i) 值观察到最高的分化水平,并且在稍微更酸性或碱性值观察到分化的抑制。将OPCs的pH(i) 夹在7.15引起ERK1/2的瞬时活化,这在更酸性或碱性值下没有观察到。此外,用UO126化合物抑制ERK活化完全阻止了响应pH(i) 位移的OPC分化。这些结果表明,pH(i) 通过ERK1/2途径起作用,是少突胶质细胞分化的关键决定因素。我们还表明,该pH(i) 途径参与了视黄酸诱导的OPC分化过程。
  • 【花粉管培养中pH的变化及生长效应。】 复制标题 收藏 收藏
    DOI:10.1016/S0176-1617(84)80045-0 复制DOI
    作者列表:Tupý J,Rhová L
    BACKGROUND & AIMS: :pH 5.9 is optimal for tobacco pollen tube growth in suspension culture. Little pH changes of sugar-mineral medium result from the release of surface-linked compounds from pollen grains. Germination and pollen tube growth bring about a progressive medium acidification resulting in total growth inhibition. An increase of the buffering capacity of the culture medium enhances pollen tube growth. When the pH was kept near the optimum by 25 mM MES-KOH buffer, pollen tubes grew for 4 days and in the presence of casein hydrolysate they reached a length of up to about 4 cm. The growth related acidification of the medium is independent of the presence of mineral cations and is not due to the hydration of respiratory CO(2). It is suggested that it is brought about by proton secretion from pollen tubes.
    背景与目标: : pH 5.9对于悬浮培养中的烟草花粉管生长是最佳的。糖矿物培养基的ph值变化很小,这是由于花粉粒中表面连接的化合物的释放所致。发芽和花粉管生长会导致培养基酸化,从而导致总生长抑制。培养基缓冲能力的增加可增强花粉管的生长。当通过25mmmes-KOH缓冲液将pH保持在最佳值附近时,花粉管生长4天,并且在酪蛋白水解产物存在下,它们达到高达约4厘米的长度。与生长相关的培养基酸化与矿物阳离子的存在无关,而不是由于呼吸CO(2) 的水合作用。建议它是由花粉管的质子分泌引起的。
  • 【血管内皮生长因子在器官培养中刺激胚胎膀胱发育。】 复制标题 收藏 收藏
    DOI:10.1111/j.1464-410X.2006.06215.x 复制DOI
    作者列表:Burgu B,McCarthy LS,Shah V,Long DA,Wilcox DT,Woolf AS
    BACKGROUND & AIMS: OBJECTIVES:To determine whether vascular endothelial growth factor A (VEGF) and its receptors are expressed during bladder development in mice when capillaries are forming, and whether exogenous VEGF might enhance the growth of endothelia and other types of bladder cells, using an embryonic organ-culture model. MATERIALS AND METHODS:Whole bladders from wild-type mice, at embryonic day (E) 14, were grown in serum-free organ culture in an air/5% CO2 atmosphere; some cultures were supplemented with VEGF and/or with VEGF receptor 1/Fc chimera (VEGFR1/Fc), which blocks VEGF bioactivity. Organs were harvested after 6 days and the expression of VEGF and related molecules assessed using immunohistochemistry. RESULTS:VEGF, VEGFR1 and VEGFR2 positive cells were immunodetected in E14 and E18 bladders. Exogenous VEGF increased whole-organ growth, as assessed by explant areas, total cell numbers, DNA and protein content; proliferation was enhanced, and apoptosis decreased, in urothelium and surrounding tissues. VEGF also increased the proportions of cells expressing endothelial (CD31) and smooth muscle (alpha smooth muscle actin) markers. VEGFR1/Fc blocked the growth-enhancing effects of exogenous VEGF. CONCLUSIONS:In organ culture, exogenous VEGF not only stimulated embryonic bladder endothelial cells but also strikingly enhanced the growth of the whole organ. Whether the effects of VEGF on diverse bladder cell populations are direct or indirect requires further investigation. The finding that VEGF protein is present in embryonic bladders in vivo raises the possibility that it has similar actions during normal development. The results also illuminate the pathobiology of certain bladder diseases in which VEGF levels have been shown to be increased.
    背景与目标:
  • 【药用水ech的消化道微生物群的与培养无关的表征揭示了三方共生。】 复制标题 收藏 收藏
    DOI:10.1128/AEM.00356-06 复制DOI
    作者列表:Worthen PL,Gode CJ,Graf J
    BACKGROUND & AIMS: :Culture-based studies of the microbial community within the gut of the medicinal leech have typically been focused on various Aeromonas species, which were believed to be the sole symbiont of the leech digestive tract. In this study, analysis of 16S rRNA gene clone libraries confirmed the presence of Aeromonas veronii and revealed a second symbiont, clone PW3, a novel member of the Rikenellaceae, within the crop, a large compartment where ingested blood is stored prior to digestion. The diversity of the bacterial community in the leech intestinum was determined, and additional symbionts were detected, including members of the alpha-, gamma-, and delta-Proteobacteria, Fusobacteria, Firmicutes, and Bacteroidetes. The relative abundances of the clones suggested that A. veronii and the novel clone, PW3, also dominate the intestinum community, while other clones, representing transient organisms, were typically present in low numbers. The identities of these transients varied greatly between individual leeches. Neither time after feeding nor feeding on defibrinated blood caused a change in identity of the dominant members of the microbial communities. Terminal restriction fragment length polymorphism analysis was used to verify that the results from the clone libraries were representative of a larger data set. The presence of a two-member bacterial community in the crop provides a unique opportunity to investigate both symbiont-symbiont and symbiont-host interactions in a natural model of digestive-tract associations.
    背景与目标: : 对药用水蛭肠道内微生物群落的基于培养的研究通常集中在各种气单胞菌物种上,这些物种被认为是水蛭消化道的唯一共生体。在这项研究中,对16S rRNA基因克隆文库的分析证实了veronii气单胞菌的存在,并揭示了第二个共生体,即Rikenellaceae的新成员clone PW3,在作物内有一个大的隔间,在消化之前会储存摄入的血液。确定了水蛭肠道中细菌群落的多样性,并检测到了其他共生体,包括 α-,γ-和 δ-变形菌,梭菌,厚壁菌和拟杆菌的成员。克隆的相对丰度表明,A. veronii和新型克隆PW3也主导着肠群落,而代表瞬态生物的其他克隆通常以少量存在。这些瞬变的身份在各个水ches之间差异很大。喂食或喂食脱纤维的血液后的时间都不会导致微生物群落主要成员的身份发生变化。末端限制性片段长度多态性分析用于验证克隆库的结果代表较大的数据集。作物中两人细菌群落的存在为在消化道关联的自然模型中研究共生体-共生体和共生体-宿主相互作用提供了独特的机会。
  • 【比较序列分析确定了适应组织培养的人轮状病毒atcc-wa株NSP4细胞毒性域之外的突变,以及其C末端的新的种间可变域。】 复制标题 收藏 收藏
    DOI:10.1007/s007050070056 复制DOI
    作者列表:Mohan KV,Atreya CD
    BACKGROUND & AIMS: :Complete nucleotide sequence of the tissue culture-adapted ATCC-Wa strain of human rotavirus NSP4 was determined. Sequence analysis detected two alternate forms of the gene with a nucleotide difference at position 331 (A or G) in the coding sequence (NSP4-A or NSP4-G) leading to a change from neutral glutamine97 in NSP4-A to a positively charged arginine97 in NSP4-G originating from the same ATCC-Wa preparation. In addition to this, both forms of ATCC-Wa NSP4 revealed three mutations at nucleotide positions 88 (T to C), 142 (C to T) and 572 (G to A), when compared to the previously reported NSP4 sequence from virulent Wa strain. The former two mutations were in the coding sequence and resulted in a leucine16 to serine16 and a proline34 to leucine34 change, while the third mutation was in the 3' non-coding region of the gene. The two amino acid changes may contribute to the 'tissue culture-adaptation' of ATCC-Wa strain. The ATCC-Wa NSP4 sequence was found to differ from the previously reported NSP4 sequence of attenuated Wa strain by lacking a mutation at 133 (T to C), though the mutations at 88 and 142 were present in both strains. Furthermore, comparison of deduced amino acid sequence of NSP4 from human, bovine, porcine and simian rotavirus strains identified a seven-residue (positions 135-141) inter-species variable domain in its C-terminal region.
    背景与目标: : 确定了人类轮状病毒NSP4的组织培养适应的atcc-wa株的完整核苷酸序列。序列分析检测到在编码序列 (NSP4-A或NSP4-G) 中位置331 (a或G) 处具有核苷酸差异的基因的两种替代形式,导致从NSP4-A的中性谷氨酰胺97变为源自相同atcc-wa制剂的NSP4-G中的带正电荷的精氨酸97。除此之外,当与先前报道的来自强毒Wa株的NSP4序列相比时,两种形式的atcc-wa NSP4在核苷酸位置88 (T至C) 、142 (C至T) 和572 (G至A) 处揭示了三个突变。前两个突变在编码序列中,导致亮氨酸16到丝氨酸16和脯氨酸34到亮氨酸34的变化,而第三个突变在基因的3' 非编码区。这两个氨基酸的变化可能有助于atcc-wa菌株的 “组织培养适应”。发现atcc-wa NSP4序列与先前报道的减毒Wa菌株的NSP4序列不同,因为在133 (T至C) 处没有突变,尽管在88和142处的突变存在于两个菌株中。此外,从人,牛,猪和猿猴轮状病毒株中推导的NSP4氨基酸序列的比较确定了其C末端区域中的七个残基 (位置135-141) 种间可变结构域。
  • 【青霉菌S1M29在分批和补料分批培养中增加了纤维素酶和木聚糖酶的产量。】 复制标题 收藏 收藏
    DOI:10.1016/j.biortech.2013.07.124 复制DOI
    作者列表:Dos Reis L,Fontana RC,da Silva Delabona P,da Silva Lima DJ,Camassola M,da Cruz Pradella JG,Dillon AJP
    BACKGROUND & AIMS: :The development of more productive strains of microorganisms and processes that increase enzyme levels can contribute to the economically efficient production of second generation ethanol. To this end, cellulases and xylanases were produced with the S1M29 mutant strain of Penicillium echinulatum, using different concentrations of cellulose (20, 40, and 60 g L(-1)) in batch and fed-batch processes. The highest activities of FPase (8.3 U mL(-1)), endoglucanases (37.3 U mL(-1)), and xylanases (177 U mL(-1)) were obtained in fed-batch cultivation with 40 g L(-1) of cellulose. The P. echinulatum enzymatic broth and the commercial enzyme Cellic CTec2 were tested for hydrolysis of pretreated sugar cane bagasse. Maximum concentrations of glucose and xylose were achieved after 72 h of hydrolysis. Glucose yields of 28.0% and 27.0% were obtained using the P. echinulatum enzymatic extract and Cellic CTec2, respectively.
    背景与目标: : 开发更具生产力的微生物菌株和提高酶水平的工艺可以有助于经济高效地生产第二代乙醇。为此,在分批和补料分批过程中,使用不同浓度的纤维素 (20、40和60g L(-1)),用棘青霉的S1M29突变菌株生产纤维素酶和木聚糖酶。在用40g L(-1) 纤维素补料分批培养中获得最高的FPase (8.3 U mL(-1)) 、内切葡聚糖酶 (37.3 U mL(-1)) 和木聚糖酶 (177 U mL(-1)) 活性。测试了echinulatum酶促肉汤和商业酶Cellic CTec2对预处理的甘蔗渣的水解作用。水解72小时后达到最大浓度的葡萄糖和木糖。分别使用棘皮草酶提取物和Cellic CTec2获得28.0% 和27.0% 的葡萄糖产量。
  • 【自体球体培养: 人脑肿瘤侵袭的筛查工具。】 复制标题 收藏 收藏
    DOI:10.1016/s1040-8428(00)00081-0 复制DOI
    作者列表:de Ridder L,Cornelissen M,de Ridder D
    BACKGROUND & AIMS: :Spheroids are three-dimensional cell aggregates expressing histotypic organisation in vitro comparable to tissue continuity in vivo. They can be prepared from normal tissue and from tumour fragments. In the experiments presented here, dermal human spheroids and brain tumour spheroids are prepared from the same patient. The dermal tissue originates from the border of the incision wound made to effect a stereotactic brain tumour biopsy. The tumour originates from a fragment of the collected stereotactic biopsy. The dermal fragment and the brain biopsy are explanted in vitro to form confluent monolayers. At confluency, the dermal cells are transferred into small Erlenmeyer flasks and rotated at 37 degrees C for 1-2 days and rotation mediated spheroids are formed. Small flaps of the tumour monolayer are placed on a semisolid non-adhesive substrate, reorganise and form agar overlay spheroids. After spheroid formation, a dermal spheroid is confronted with a brain tumour derived spheroid. The confronting pair, after adhering to each other, present an invasion model in vitro. The dermal spheroid functions as the autologous host for the brain tumour spheroid. Putative invasive cells present in the reaggregated brain spheroid will invade the dermal spheroid and destroy it. If no invasive cells are present in the tumour derived spheroid no morphologic changes will be seen in the dermal spheroid; 24 tested brain biopsy spheroids demonstrated a clear correlation between malignancy in situ and invasiveness in vitro. So it can be concluded that the autologous confrontation of brain tumour derived spheroids with dermal spheroids derived from the patient has a predictive value concerning malignant evolution and mimics the situation of the tumour in situ.
    背景与目标: : 球体是三维细胞聚集体,在体外表达组织类型,与体内组织连续性相当。它们可以从正常组织和肿瘤碎片中制备。在这里介绍的实验中,皮肤人球体和脑肿瘤球体是由同一患者制备的。真皮组织起源于切口伤口的边界,以进行立体定向脑肿瘤活检。肿瘤起源于收集的立体定向活检的片段。在体外移植真皮碎片和脑活检以形成汇合的单层。汇合时,将真皮细胞转移到小锥形瓶中,并在37 ℃ 旋转1-2天,并形成旋转介导的球体。将肿瘤单层的小皮瓣放置在半固体非粘附基质上,重组并形成琼脂覆盖球体。球体形成后,真皮球体面对脑肿瘤衍生的球体。相互粘附后,面对的一对在体外呈现入侵模型。真皮球体充当脑肿瘤球体的自体宿主。在重新聚集的大脑球体中存在的假定的侵入性细胞将侵入真皮球体并破坏它。如果肿瘤衍生的球体中没有浸润性细胞,则真皮球体中不会出现形态学变化; 24个经过测试的脑活检球体表明原位恶性肿瘤与体外侵袭性之间存在明显的相关性。因此可以得出结论,脑肿瘤衍生的球体与患者衍生的真皮球体的自体对抗具有有关恶性演变的预测价值,并模仿了原位肿瘤的情况。
  • 【Mg2和多胺对培养的啮齿动物神经元兴奋性氨基酸电流的神经调节。】 复制标题 收藏 收藏
    DOI: 复制DOI
    作者列表:Kumamoto E
    BACKGROUND & AIMS: Excitatory amino-acid currents in rodent central neurones are mediated by the activation of glutamate receptors. Ionotropic types of the receptors are divided into alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA), kainate and N-methyl-D-aspartate (NMDA) receptors, and the former two are collectively called non-NMDA receptors. The NMDA receptor is modulated by a number of endogenous neuromodulators including Mg2+, polyamines, glycine and protons in extracellular solutions. Although it has been generally thought that each of the neuromodulators acts on a distinct site in the NMDA receptor, recent studies have revealed that these actions may be not necessarily independent of each other. The NMDA receptor response is not only inhibited but also potentiated by Mg2+, and the latter action is due to an interaction of a Mg2+ site with either glycine- or proton-binding site. In the presence of polyamines, a tonic inhibition by protons of the NMDA receptor response is relieved, resulting in a potentiation of the response. Alternatively, it has been recently revealed that there are some subtypes of non-NMDA receptors which are negatively modulated by polyamines in either extra- or intra cellular solutions. The difference in polyamine sensitivity among non-NMDA receptors is attributed to a distinction in their constituted subunits. The inhibition of non-NMDA receptor by intracellular polyamines results in inward rectification of the current-voltage relation which is not seen for polyamine-insensitive ones. This polyamine action is not mimicked by intracellular Mg2+.

    背景与目标: 啮齿动物中枢神经元中的兴奋性氨基酸电流由谷氨酸受体的激活介导。离子型受体分为alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA),kainate和N-甲基-D-天冬氨酸 (NMDA) 受体,前两者统称为非NMDA受体。NMDA受体受到许多内源性神经调节剂的调节,包括细胞外溶液中的Mg2,多胺,甘氨酸和质子。尽管人们普遍认为每种神经调节剂都作用于NMDA受体的不同部位,但最近的研究表明,这些作用可能不一定彼此独立。NMDA受体反应不仅受到抑制,而且还受到Mg2的增强,后者的作用是由于Mg2位点与甘氨酸或质子结合位点的相互作用。在存在多胺的情况下,质子对NMDA受体反应的强音抑制被缓解,从而导致反应增强。或者,最近已经发现,在细胞外或细胞内溶液中,有一些非NMDA受体的亚型被多胺负调节。非NMDA受体之间多胺敏感性的差异归因于其组成亚基的差异。细胞内多胺对非NMDA受体的抑制导致电流-电压关系的内向整流,这对于多胺不敏感的人是看不到的。细胞内Mg2不会模仿这种多胺作用。
  • 【金黄色葡萄球菌临床分离株的生物膜形成受到补充葡萄糖和氯化钠的培养基的不同影响。】 复制标题 收藏 收藏
    DOI:10.3390/jcm8111853 复制DOI
    作者列表:Lade H,Park JH,Chung SH,Kim IH,Kim JM,Joo HS,Kim JS
    BACKGROUND & AIMS: :Staphylococcus aureus (S. aureus) causes persistent biofilm-related infections. Biofilm formation by S. aureus is affected by the culture conditions and is associated with certain genotypic characteristics. Here, we show that glucose and sodium chloride (NaCl) supplementation of culture media, a common practice in studies of biofilms in vitro, influences both biofilm formation by 40 S. aureus clinical isolates (methicillin-resistant and methicillin-sensitive S. aureus) and causes variations in biofilm quantification. Methicillin-resistant strains formed more robust biofilms than methicillin-sensitive strains in tryptic soy broth (TSB). However, glucose supplementation in TSB greatly promoted and stabilized biofilm formation of all strains, while additional NaCl was less efficient in this respect and resulted in significant variation in biofilm measurements. In addition, we observed that the ST239-SCCmec (Staphylococcal Cassette Chromosome mec) type III lineage formed strong biofilms in TSB supplemented with glucose and NaCl. Links between biofilm formation and accessory gene regulator (agr) status, as assessed by δ-toxin production, and with mannitol fermentation were not found. Our results show that TSB supplemented with 1.0% glucose supports robust biofilm production and reproducible quantification of S. aureus biofilm formation in vitro, whereas additional NaCl results in major variations in measurements of biofilm formation.
    背景与目标: : 金黄色葡萄球菌 (S. aureus) 引起持续的生物膜相关感染。金黄色葡萄球菌的生物膜形成受培养条件的影响,并与某些基因型特征有关。在这里,我们显示了培养基的葡萄糖和氯化钠 (NaCl) 补充,这是体外生物膜研究的常见做法,影响了40株金黄色葡萄球菌临床分离株 (耐甲氧西林和甲氧西林敏感金黄色葡萄球菌) 的生物膜形成,并导致生物膜定量的变化。在胰蛋白酶大豆肉汤 (TSB) 中,耐甲氧西林的菌株比对甲氧西林敏感的菌株形成更坚固的生物膜。然而,TSB中的葡萄糖补充极大地促进和稳定了所有菌株的生物膜形成,而额外的NaCl在这方面的效率较低,并导致生物膜测量的显着变化。此外,我们观察到ST239-SCCmec (葡萄球菌盒染色体mec) III型谱系在补充了葡萄糖和NaCl的TSB中形成了强生物膜。未发现通过 δ 毒素产生评估的生物膜形成与辅助基因调节剂 (agr) 状态以及甘露醇发酵之间的联系。我们的结果表明,补充有1.0% 葡萄糖的TSB支持体外稳定的生物膜产生和金黄色葡萄球菌生物膜形成的可重复定量,而额外的NaCl导致生物膜形成的测量结果的主要变化。
  • 【走向更安全的文化: 在新西兰手术室实施基于多学科模拟的团队培训 -- 框架分析。】 复制标题 收藏 收藏
    DOI:10.1136/bmjopen-2018-027122 复制DOI
    作者列表:Jowsey T,Beaver P,Long J,Civil I,Garden AL,Henderson K,Merry A,Skilton C,Torrie J,Weller J
    BACKGROUND & AIMS: AIM:NetworkZ is a simulation-based multidisciplinary team-training programme designed to enhance patient safety by improving communication and teamwork in operating theatres (OTs). In partnership with the Accident Compensation Corporation, its implementation across New Zealand (NZ) began in 2017. Our aim was to explore the experiences of staff - including the challenges they faced - in implementing NetworkZ in NZ hospitals, so that we could improve the processes necessary for subsequent implementation. METHOD:We interviewed staff from five hospitals involved in the initial implementation of NetworkZ, using the Organising for Quality model as the framework for analysis. This model describes embedding successful quality improvement as a process of overcoming six universal challenges: structure, infrastructure, politics, culture, motivation and learning. RESULTS:Thirty-one people participated. Structural support within the hospital was considered essential to maintain staff enthusiasm, momentum and to embed the programme. The multidisciplinary, simulation-based approach to team training was deemed a fundamental infrastructure for learning, with participants especially valuing the realistic in situ simulations and educational support. Participants reported positive changes to the OT culture as a result of NetworkZ and this realisation motivated its implementation. In sites with good structural support, NetworkZ implementation proceeded quickly and participants reported rapid cultural change towards improved teamwork and communication in their OTs. CONCLUSION:Implementation challenges exist and strategies to overcome these are informing future implementation of NetworkZ. Embedding the programme as business as usual across a nation requires significant and sustained support at all levels. However, the potential gains in patient safety and workplace culture from widespread multidisciplinary team training are substantial. Trial registration number ACTRN12617000017325.
    背景与目标:
  • 【一种新的营养浓度降低的培养基支持小鼠胚胎的发育和生存能力。】 复制标题 收藏 收藏
    DOI:10.1038/s41598-020-66019-4 复制DOI
    作者列表:Ermisch AF,Herrick JR,Pasquariello R,Dyer MC,Lyons SM,Broeckling CD,Rajput SK,Schoolcraft WB,Krisher RL
    BACKGROUND & AIMS: :Further refinement of culture media is needed to improve the quality of embryos generated in vitro. Previous results from our laboratory demonstrated that uptake of nutrients by the embryo is significantly less than what is supplied in traditional culture media. Our objective was to determine the impact of reduced nutrient concentrations in culture medium on mouse embryo development, metabolism, and quality as a possible platform for next generation medium formulation. Concentrations of carbohydrates, amino acids, and vitamins could be reduced by 50% with no detrimental effects, but blastocyst development was impaired at 25% of standard nutrient provision (reduced nutrient medium; RN). Addition of pyruvate and L-lactate (+PL) to RN at 50% of standard concentrations restored blastocyst development, hatching, and cell number. In addition, blastocysts produced in RN + PL contained more ICM cells and ATP than blastocysts cultured in our control (100% nutrient) medium; however, metabolic activity was altered. Similarly, embryos produced in the RN medium with elevated (50% control) concentrations of pyruvate and lactate in the first step medium and EAA and Glu in the second step medium were competent to implant and develop into fetuses at a similar rate as embryos produced in the control medium. This novel approach to culture medium formulation could help define the optimal nutrient requirements of embryos in culture and provide a means of shifting metabolic activity towards the utilization of specific metabolic pathways that may be beneficial for embryo viability.
    背景与目标: : 需要进一步细化培养基,以提高体外产生的胚胎的质量。我们实验室的先前结果表明,胚胎对营养的吸收明显少于传统培养基中提供的营养。我们的目标是确定培养基中营养浓度降低对小鼠胚胎发育,代谢和质量的影响,作为下一代培养基配方的可能平台。50% 可以降低碳水化合物,氨基酸和维生素的浓度,而没有有害作用,但是在标准营养素供应 (营养培养基减少; RN) 的25% 下,囊胚发育受损。以50% 标准浓度向RN添加丙酮酸和L-乳酸 (PL) 可恢复胚泡发育,孵化和细胞数量。此外,在rn   +  PL中产生的囊胚比在我们的对照 (100% 营养) 培养基中培养的囊胚含有更多的ICM细胞和ATP; 然而,代谢活性发生了改变。类似地,在RN培养基中产生的胚胎具有升高 (50% 对照) 浓度的丙酮酸和乳酸在第一步培养基中以及在第二步培养基中产生的EAA和Glu的胚胎能够以与在对照培养基中产生的胚胎相似的速率植入和发育成胎儿。这种新颖的培养基配方方法可以帮助确定培养物中胚胎的最佳营养需求,并提供一种将代谢活性转移到利用可能有益于胚胎生存的特定代谢途径的手段。
  • 【鱼露发酵的发酵剂Virgibacillus sp. SK37及其细胞结合蛋白酶的水解活性。】 复制标题 收藏 收藏
    DOI:10.1007/s11274-012-1075-5 复制DOI
    作者列表:Sinsuwan S,Rodtong S,Yongsawatdigul J
    BACKGROUND & AIMS: :Fish sauce production relies on a natural fermentation process requiring 12-18 months for process completion. Virgibacillus sp. SK37 has been shown to be a potential strain for fish sauce acceleration. However, hydrolytic activity of proteinases bound at cell surface of this strain has not been well elucidated. Addition of 0.2 % CaCl(2) (w/w) in conjunction with starter cultures of Virgibacillus sp. SK 37 increased protein hydrolysis as measured by α-amino group content throughout fermentation (P < 0.05). Cell-bound proteinases from Virgibacillus sp. SK 37 were extracted into a free form by incubating the washed cells in Ca(2+)-free buffer at 37 °C for 2 h. Cell-bound proteinases revealed molecular mass of 19, 20, 22, 32, 34, and 44 kDa based on a synthetic peptide zymogram. The proteinases showed subtilisin-like serine characteristics with the highest activity at 50 °C and pH 8 and 11. Activity of the extracted proteinases increased ~4 times at ≥100 mM CaCl(2). In addition, CaCl(2) enhanced thermal stability of the extracted proteinases. Enzymes showed proteolytic activity in either the absence or presence of 10 and 25 % NaCl toward fish muscle, soy protein isolate, and casein substrates. Cell-bound proteinases were likely to play an important role in protein hydrolysis during fish sauce fermentation.
    背景与目标: : 鱼露生产依赖于自然发酵过程,需要12-18个月才能完成过程。Virgibacillus sp。SK37已被证明是鱼露加速的潜在菌株。然而,尚未很好地阐明该菌株细胞表面结合的蛋白酶的水解活性。添加0.2% CaCl(2) (w/w) 与Virgibacillus sp. SK 37的发酵剂培养物一起增加了蛋白质水解,如在整个发酵过程中通过 α-氨基含量测量 (P <0.05)。通过将洗涤过的细胞在不含Ca(2) 的缓冲液中于37 °C孵育2小时,将来自Virgibacillus sp. SK 37的细胞结合蛋白酶提取为游离形式。根据合成肽酶谱,细胞结合蛋白酶的分子量为19、20、22、32、34和44 kDa。蛋白酶表现出枯草杆菌蛋白酶样丝氨酸特征,在50 °C和pH 8和11时活性最高。提取的蛋白酶的活性在 ≥ 100 mM CaCl(2) 时增加了约4倍。此外,CaCl(2) 增强了提取的蛋白酶的热稳定性。在不存在或存在10和25% NaCl的情况下,酶对鱼肌肉,大豆分离蛋白和酪蛋白底物表现出蛋白水解活性。在鱼露发酵过程中,细胞结合的蛋白酶可能在蛋白质水解中起重要作用。

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