Interfacial and micellar behavior of glucose lipid

Summary Glucose lipid of notable surfactant properties was produced by using hydrocarbon assimilating bacterium of the bacterial strain MM1. Its surface active properties were notable in spite of ,-hydrophilic and bulky molecule. The critical micelle concentration (cmc) was small (0.165 M); surface and interfacial tension for hexadecane at 0.1 % (pH 7.35) solution, 24.6 and 13.3 mN/m, respectively. The emulsifying action was excellent and comparable to those of rhamnolipids. The micelle has the outer radius. 28.5 Å and inner core, 6.7 Å on the basis of the concentric spherical shell model by means of the small angle X-ray solution scattering measurement.Dedicated to Professor Fritz Wagner on the occasion of his 65th birthday.     

Morphological alterations and cytoskeletal reorganization in opossum kidney (OK) cells during osmotic swelling and volume regulation

Cells from a variety of tissues regulate their volume when exposed to anisotonic conditions. After exposure of cells to hypotonic conditions, the rapid phase of cell swelling is followed by a slower phase of cell shrinkage towards the initial volume. The present study investigates morphological alterations of adherent and fully spread cells after exposure to hypotonic conditions and the reorganization of cytoskeletal components such as F-actin, actin-binding proteins, microtubules and intermediate-sized filaments. We used cells of a continuous epithelial cell line from the opossum kidney (OK cells), which were exposed to hypotonic conditions for a period of 60 min at 25° C. The osmolarity was reduced by 40% from 320 mosmol/l (isotonic conditions) to 192 mosmol/l (hypotonic conditions). The initial swelling after exposure of OK cells to hypotonic conditions caused enhanced ruffling membrane activity, formation of lamellipodia and an extended space between adjacent cells which was caused by a more rounded cell shape. Moreover, the height of cells located in the centre of cell clusters increased by 32±8% (mean value±SEM) as checked by morphometric analysis of the vertical distance between the apical and basolateral F-actin domain. Although the fluorescence intensity and organization of F-actin in a horizontal direction remained unaltered during cell swelling, we observed a loss of periodicity and irregular distribution of myosin aggregates and a partial rear-rangement of vimentin filaments in the form of short fragments. In all experiments the organization of microtubules was observed to be unaltered. The alterations described above were reversible during cell shrinkage towards the initial volume, i.e. at 60 min after exposure to hypotonic conditions cell morphology and cytoskeletal organization no longer differed from the corresponding controls which were kept under isotonic conditions for the whole experimental period. The results demonstrate that only certain intracellular cytoskeletal components are actively involved in cell swelling and regulatory volume decrease.     

Midwife managed delivery unit: a randomised controlled comparison with consultant led care.

OBJECTIVE--To examine whether intrapartum care and delivery of low risk women in a midwife managed delivery unit differs from that in a consultant led labour ward. DESIGN--Pragmatic randomised controlled trial. Subjects were randomised in a 2:1 ratio between the midwives unit and the labour ward. SETTING--Aberdeen Maternity Hospital, Grampian. SUBJECTS--2844 low risk women, as defined by existing booking criteria for general practitioner units in Grampian. 1900 women were randomised to the midwives unit and 944 to the labour ward. MAIN OUTCOME MEASURES--Maternal and perinatal morbidity. RESULTS--Of the women randomised to the midwives unit, 647 (34%) were transferred to the labour ward antepartum, 303 (16%) were transferred intrapartum, and 80 (4%) were lost to follow up. 870 women (46%) were delivered in the midwives unit. Primigravid women (255/596, 43%) were significantly more likely to be transferred intrapartum than multi-gravid women (48/577, 8%). Significant differences between the midwives unit and labour ward were found in monitoring, fetal distress, analgesia, mobility, and use of episiotomy. There were no significant differences in mode of delivery or fetal outcome. CONCLUSIONS--Midwife managed intrapartum care for low risk women results in more mobility and less intervention with no increase in neonatal morbidity. However, the high rate of transfer shows that antenatal criteria are unable to determine who will remain at low risk throughout pregnancy and labour.     

Radiation-induced concomitant overexpression of p53, p62c-fos and p21N-fas in mouse epidermis

Abstract. Early molecular events in radiation carcinogenesis in vivo are difficult to study, especially because it is usually impossible to know in advance the exact location of a radiation-induced tumour. In the present study, we have attempted to overcome this difficulty by exposing a very small area of hairless mouse skin to high-dose beta radiation (i.e. immobilized hot particles) on the reasonable assumption that a malignant tumour would subsequently develop and be found at the exposed site in a long-term follow-up. The results showed that at an exposed site, before the appearance of a visible or histologically detectable tumour, overexpression of the product of the tumour suppressor gene p53 was common (28% of the sites studied; tested with PAbl801, PAb421, PAb240 and a polyclonal antibody CM1) and that this change was regularly accompanied by overexpression of p62^c-fos and p21^N-ras. Expression of several other oncoproteins studied (p39^c-jun, p21^K-ras, p21^H-ras) was not altered at these sites. A similar pattern of changes was observed in a visible and histopathologically distinct tumour that was analyzed after its development at an exposed site. These results suggest a re'markably regular pattern of molecular changes, induced by ionizing radiation in mouse epidermis, which might be associated with carcinogenesis.     

艾氏剂环氧化酶及细胞色素P－450对小菜蛾抗药性发展的影响

本文对室内长期饲养的小菜蛾（Ｐｌｕｔｅｌｌａ　ｘｙｌｏｓｔｅｌｌａ　Ｌ．）敏感品系和田间采集的抗性种群体内的艾氏剂平氧化酶及细胞色素Ｐ－４５０进行了比较研究。结果证明,艾氏剂环氧化酶在感性和抗性小菜蛾间存在着量及质的差异。抗性种群的艾氏剂环氧化酶的Ｖｍａｘ和Ｋｍ值分别为感性品系的５．４％和６．５倍。抗性种群的细胞色素Ｐ－４５０的含量是感性品系的１．１—１．３倍。艾氏剂环氧化酶在量上及质上的差异及细胞色素Ｐ－４５０含量的提高是导致小菜蛾抗药性发生与发展的重要机制之一。而且质的差异较之量的差异可能起着更为重要的作用．     

Origin and clonal relationship of common inhibitory motoneurons CI1 and CI3 in the locust CNS

In the primordial thoracic ganglia of locust embryos, the bromodeoxiuridine (BrdU) technique for labelling proliferating cells and their progeny was combined with intracellular dye injection to investigate the origin and the clonal relationship of common inhibitory motoneurons. Common inhibitors 1 (CI₁) and 3 (CI₃) were found to be siblings, that is, they are produced by the division of one ganglion mother cell. This ganglion mother cell results from the first division of neuroblast 5–5, at about 30% of embryonic development. A large portion, at least, of the ganglion mother cells produced by subsequent divisions of neuroblast 5–5 give rise to interneurons with contralaterally ascending or descending axons and GABA-like immunoreactivity. Thus, CI₁ and CI₃ are more closely related to putative inhibitory interneurons than they are to other, that is, excitatory, motoneurons. Consistent with this, the CI somata are associated with cell bodies of putative inhibitory interneurons rather than with clusters of excitatory motoneuron somata. These results elicit speculations regarding the evolutionary origin of inhibitory motoneurons. 1994 John Wiley & Sons, Inc.     

中华蜜蜂和意大利蜜蜂感染囊状幼虫病毒后免疫及发育相关基因表达比较

【目的】本文旨在探究囊状幼虫病毒(sacbrood virus, SBV)对中华蜜蜂(Apis cerana cerana,简称中蜂)和意大利蜜蜂(Apis mellifera ligustica,简称意蜂)工蜂幼虫发育和免疫基因、营养代谢基因、抗病毒基因、细胞发育及代谢相关基因表达的影响。【方法】从蜂群中移取2日龄的中蜂和意蜂幼虫,在培养箱(34℃, RH 85%)进行人工饲养,3日龄时接种SBV病毒,每天观察记录死亡情况,并通过实时定量PCR (real-time quantitative polymerase chain reaction, RT-qPCR)检测4日龄和7日龄幼虫体内SBV基因相对表达量,及免疫基因(Apidaecin、Abaecin、Hymenoptaecin、Denfensin、Lys-1、Pgrp-lc、Kenny、Domeless)、营养代谢基因(Ilp1、Hex110、Vg)、抗病毒基因(Dis3、Dicer、Ago1)、细胞组成及发育调控基因(Vhdl、Co-1-iv)以及细胞代谢和调控基因(Mta1)的表达水平。【结果】通过分析比较发现,感染相同剂量...     

单增李斯特菌胎盘感染的体内外模型研究进展

单核细胞增生李斯特氏菌（Listeria monocytogenes）是重要的食源性致病菌,能引发人类的李斯特菌病,是全球公共卫生问题之一。该菌易感染孕妇,引起胎儿和新生儿的侵袭性李斯特菌病,严重威胁母婴健康。因此,建立有效的单增李斯特菌感染胎盘体内外模型,解析和探究单增李斯特菌经胎盘感染机制,是预防和控制单增李斯特菌感染母婴的关键所在。本文综述了可用于研究单增李斯特菌母婴感染的体内外胎盘模型,总结和讨论了各类模型的优势和局限性;并着重分析了体外三维胎盘屏障模型在单增李斯特菌感染方面的研究进展和未来研究方向。以期为深入解析该菌经胎盘感染的途径、发病机制提供支持,并为预防和控制母婴李斯特菌病提供科学参考。     

circPVT1通过miR-24-3p/let-7a-5p/FSCN1轴促进鼻咽癌细胞侵袭迁移

目的 鼻咽癌是一种来源于鼻咽上皮的恶性肿瘤,其临床特征之一是易发生淋巴转移,但是目前鼻咽癌转移的分子机制尚未阐明。circPVT1是由PVT1基因2号外显子反向拼接形成的环状RNA (circRNA),在多种肿瘤中表达上调,本文探讨了circPVT1在鼻咽癌侵袭迁移中的作用和分子机制。方法 通过RT-qPCR检测circPVT1及其下游miRNA和FSCN1在鼻咽癌细胞的表达情况,Transwell和划痕愈合实验检测circPVT1对鼻咽癌细胞侵袭迁移的影响,RNA pull-down实验检测circPVT1结合的miRNA,双荧光素酶报告实验检测miR-24-3p和let-7a-5p靶向抑制FSCN1 mRNA表达。结果 在鼻咽癌细胞中过表达circPVT1可以促进鼻咽癌细胞侵袭迁移,而敲低circPVT1则可以抑制鼻咽癌细胞的侵袭迁移。进一步研究发现,circPVT1可以通过竞争性吸附miR-24-3p和let-7a-5p,上调FSCN1的表达,从而促进鼻咽癌细胞的侵袭迁移。结论 circPVT1通过miR-24-3p/let-7a-5p/FSCN1轴促进鼻咽癌细胞侵袭迁移,证实c...