In-vitro effects of angiotensin II on steroid production by hamster ovarian follicles and on ultrastructure of the theca interna

Summary Angiotensin II (AII) is present in the mammalian ovary and has been correlated with atresia in follicles. Since the theca interna may be one site at which atresia is intiated, we wished to determine whether AII exerts an effect on theca interna from explanted ovarian follicles of hamsters. Hamsters were sacrified on the morning of proestrus, and ovaries were removed. Preovulatory follicles were excised from the ovaries, and cultured with one of the following components: medium alone (control); medium plus AII (1x10^-6 M); the AII-receptor antagonist [Sar¹, Ile⁸] AII (1x10^-4 M); or AII plus antagonist. After 72 h, the follicles were processed for transmission electron microscopy (to determine quantities of theca interna organelles involved in the steroid synthetic pathway) or for protein determination (to normalize steroid production rates). The incubation medium was drawn off and analyzed by radioimmunoassay for progesterone, androstenedione, or estradiol-17. There was a significant positive correlation (r=0.92, P<0.01) between follicular androstenedione secretion and area comprising theca interna smooth endoplasmic reticulum. In the theca interna, AII induced a two-fold and 1.6-fold increase in lipid droplet number and area comprising smooth endoplasmic reticulum, respectively (P<0.05). Excess antagonist negated the increase in cell or-ganelles and also reduced androstenedione secretion compared with AII alone (P<0.05). Most importantly, AII significantly augmented the ratio of androstenedione: estradiol-17 secretion by 44% over that of control. The ultrastructural changes observed in this study and the increase in the andostenedione: estradiol-17 production ratio are consistent with atresia-like changes in ovarian follicles. We believe, therefore, that AII is involved, possibly at its membrane receptor, in an aspect of the overall process of follicular atresia, operating in part at the level of the theca interna.     

几种药物用于烧伤大鼠局部抗感染作用的观察

在烧伤大鼠创面接种绿脓杆菌（１０９ＣＦＵ／ｍｌ,）使用银锌霜、磺胺嘧啶银霜,生态霜及空白霜膏抗感染实验,结果发现：生态霜作用与磺胺嘧啶银、银锌霜效果相当,既能拮抗绿脓杆菌感染,又对创面有保护作用,如先使用生态霜效果更好。     

Cytopathology of Follicular Tumours of the Thyroid With Clear Cell Change

A retrospective cytological study of nine follicular tumours of the thyroid with clear cell change was undertaken. In five clear cell adenomas and one moderately differentiated clear cell follicular carcinoma the epithelial cells occurred singly or in sheets and clusters; they sometimes assumed a trabecular or follicular pattern. The cells usually had pale diffusely vacuolated cytoplasm with ill-defined boundaries, a variable degree of anisonucleosis, nucleolar enlargement, and nuclear overlapping. Smears from a signet-ring cell adenoma contained in addition a few cells with large cytoplasmic vacuoles and compressed eccentric nuclei. In these cases a cytological diagnosis of 'follicular lesion' (or follicular neoplasia), clear cell type or signet-ring cell type, was given. A cytodiagnosis of 'carcinoma' was made only in the poorly differentiated follicular carcinoma-clear cell variant studied which showed unequivocal features of malignancy. Features suggestive of thyroid cyst, nodular goitre, Hashimoto's thyroiditis, and cell hyperactivity (marginal vacuoles, 'fire flare') were also found in the aspirated specimens of these cases of clear cell tumour of the thyroid.     

Subsurface tubular system in the outer sensory cells of the rat cochlea

Summary The system of subsurface tubules in the outer sensory cells of the rat cochlea consists of tubules lying immediately beneath the cell membrane. The tubules extend from the region below the cuticular plate, follow without interruption along the contours of the cell membrane, and terminate as a complicated, branched system under the nucleus. Several mitochondria are found on the cytoplasmic side of the tubules. Microtubules are observed in the space between the subsurface tubules and the mitochondria, in contact with the membranes of the subsurface system and, rarely, in contact with small, stalked vesicles.Current theories on the role of the subsurface system are discussed and a new one, considering possible involvement of the system in transport of the synaptic transmitter, is proposed.     

Chemistry,clones, and circadian control of the dinoflagellate bioluminescent system. The Marlene DeLuca memorial lecture

Bioluminescence in the dinoflagellate Gonyaulax polyedra occurs as brief bright flashes, originating from many (～400) small (～0.5 μm) cytoplasmic organelles which protrude into the acidic vacuole, and are thus surrounded by the tonoplast. Biochemically, the substrate is unusual; it is an open chain tetrapyrrole, highly unstable to air but protected in the cell at pH? 8 by virtue of a luciferin binding protein (LBP). This molecule is a dimer of 72 kDa subunits which, upon a decrease in pH, releases luciferin to react with oxygen in the luciferase (～140 kDa) catalysed luminescent reaction. cDNAs for both luciferase and LBP have been isolated and cloned, and the identity of LBP was confirmed by hybrid selection and in vitro translation of the message. The tenfold circadian (day to night) change in the amount of LBP, which parallels the in vivo rhythm of luminescence, is due to de novo synthesis and subsequent degradation of the protein each day. The LBP mRNA levels, as determined by in vitro translations and by Northern hybridizations, do not vary over the daily cycle, indicating that circadian control of bioluminescence in this species is mediated at the level of translation.     

溶酶体相关细胞器生物发生复合体相互作用组构成胞内体运输网络

随着高等生物中十几个新的参与囊泡运输的 Hermansky-Pudlak 综合征(HPS)蛋白质的发现, 认为可能存在一类新的囊泡运输通路。该通路主要由新近鉴定的 3 个被称为溶酶体相关细胞器生物发生复合体(BLOC)所组成, 被分别命名为BLOC-1、BLOC-2 和 BLOC-3。越来越多的证据表明这些复合体与以前认识较清楚的 AP3 和 HOPS 复合体共同在胞内体运输中起重要作用。这些复合体之间的相互作用构成了以胞内体和细胞骨架为连接纽带的参与蛋白质运输的复杂网络。该网络中的每个节点的相互作用可区分为复合体内和复合体外相互作用两大类。复合体之间的联系可以是来自不同复合体亚基间的直接相互作用, 也可以通过耦联的节点联结不同的复合体。解析这一复杂网络有助于进一步了解参与蛋白质和膜运输这一动态而精细网络的结构与功能。一旦该网络结构得到破坏, 则可能导致如 HPS 这类囊泡运输或细胞器发生障碍性疾病。     

Monolayer culture of pancreatic islets from the syrian hamster

Summary Pancreatic islets of Langerhans of the Syrian hamster were maintained in culture for as long as 43 wk. Islets were prepared by collagenase/hyaluronidase digestion of minced pancreas. The islets quickly attached to the plastic culture flasks and lost their spherical form as they flattened out to form circular monolayers. Few fibroblastoid cells were observed. As outward migration continued, the islets became vacoulated with the ultimate formation of monolayer rings. Throughout the culture period the beta cells continued to synthesize and secrete insulin. Furthermore, the cells maintained a responsiveness to glucose stimulation with increased rates of hormone secretion in the presence of elevated concentrations of the sugar. These studies demonstrate the suitability of Syrian hamster islets for studies involving long-term culture. This work was supported by Grants CA26651 and AM31669 from the National Institutes of Health, DHHS: by Grant 82-10 from the Hospital for Sick Children Foundation (Toronto); and by the Ontario Cancer Treatment and Research Foundation. The authors acknowledge the expert technical assistance of Anoja Giles.     

鹤顶兰胚囊发育过程中微管变化的共焦显微镜观察

光镜的观察确定了鹤顶兰（Ｐｈａｉｕｓ ｔａｎｋｅｒｖｉｌｌｉａｅ （Ａｉｔｏｎ） Ｂｌ．）胚囊发育属单孢子蓼型。应用免疫荧光标记技术及共焦镜观察了胚囊发育过程中微管分布的变化。当孢原细胞初形成时,细胞内的微管呈网状分布。之后,孢原细胞体积增大发育为大孢子母细胞。大孢子母细胞延长,进入减数分裂Ⅰ。微管由分裂前的网状分布变为辐射状排列。二分体的两个细胞内的微管分布一样,呈辐射状。四分体的近珠孔端的３ 个大孢子解体,细胞内的微管消失。靠合点端的功能大孢子内有许多微管呈网状分布。当功能大孢子进入第一次有丝分裂时,细胞内的微管由网状变为辐射状,从核膜伸展至周质。再经两次有丝分裂形成八核胚囊。在核分裂之前微管一般是呈网状分布并紧包围着核。在分裂期间二核和四核胚囊都呈极性现象,微管系统也呈极性分布。微管在八核胚囊内的分布变化情形特别复杂。首先,八核分别作不同程度的移动,其中两个核移向胚囊中央,珠孔端和合点端的３ 个核分别互相靠拢,形成３ 个区,即中央区、反足区和卵器区。胚囊未形成区时,８ 个核都被网状分布的微管包围着。当胚囊明显分成区时,反足区内的微管仍作网状分布。中央区的微管分布则趋疏松,形成篮形结构,包围着液泡和两个极核。在