Various characteristics of the structure and synthesis of procollagens produced by cultured skin fibroblasts from patients with Danlos-Ehlers syndrome type I

The electrophoretic mobilities of the collagen and procollagen type I and III chains synthesized by the fibroblasts isolated from patients with type I Ehlers-Danlos syndrome as well as a set of peptides obtained by splitting of pro alpha 1(I) and pro alpha 2(I) type I procollagens by cyanbromide are not different from the normal ones. The fact demonstrates the absence of long insertions or deletions, or the sufficient defects in intracellular chain modifications. The changes were also nor registered for the ratio of type I and III collagens from the digested by pepsin preparations of protein accumulating in the culture media of the cultured skin fibroblasts from patients. The studied strains of cultured fibroblasts from patients suffering the Ehlers-Danlos syndrome have the trend to increased accumulation of partially processed chains of proc alpha 1(I) and proc alpha 2(I) type I procollagen and to the increased ratio of pro alpha 1(I) to pro alpha 2(I).     

Isolation and characteristics of surface proteins from Streptococcus group A

Cell wall surface proteins of group A Streptococcus type 29 were extracted with 1 M hydroxylamine pH 6.0. The purification procedure included fractionation with ammonium sulfate and gel filtration on Sephadex G-150. SDS polyacrylamide gel electrophoresis revealed a number of proteins (approximately 20) with molecular mass of 70 kD; the difference in Mr between the proteins was 5-10 kD. Isoelectrofocusing demonstrated that the proteins are either acid (pI = 3.7) or weakly alkaline (pI = 7.7). Possible reasons for the heterogeneity of Streptococcus cell wall surface proteins are discussed.     

红腹锦鸡肺的组织结构与微血管构筑

为了了解红腹锦鸡(Chroysolophus pictus)肺的微细结构和微血管构筑特征,为呼吸生物学研究提供形态学依据,用组织学方法和微血管铸型技术在光镜和扫描电镜下观察研究了红腹锦鸡肺的组织结构与微血管构筑情况。结果表明,红腹锦鸡肺主要由各级支气管构成,从三级支气管上呈辅射状分出许多呼吸毛细管(微气管),并相互吻合成网状,呼吸毛细管外面包围有丰富的毛细血管;红腹锦鸡肺毛细血管垂直围绕在各微气管外,并相互吻合成密集的立体微血管网;毛细血管管径4.5~7.0μm,微气管直径11~50μm。并对肺微血管构筑情况与呼吸效率的关系作了探讨。     

Vesicular Transport of Extracellular Acid Phosphatases in Yeast Saccharomyces cerevisiae

A method for isolation of secretory vesicles from the yeast Saccharomyces cerevisiae based on the disintegration of protoplasts by osmotic shock followed by separation of the vesicles by centrifugation in a density gradient of Urografin was developed in this study. Two populations of the secretory vesicles that differ in density and shape were separated. Acid phosphatases (EC 3.1.3.2) were used as markers of the secretory vesicles. It was shown that the constitutive acid phosphatase (PHO3 gene product) is mainly transported to the cell surface by a lower density population of vesicles, while the repressible acid phosphatase (a heteromer encoded by PHO5, PHO10, and PHO11 genes) by a vesicle population of higher density. These data provide evidence that at least two pathways of transport of yeast secretory proteins from the place of their synthesis and maturation to the cell surface may exist. To reveal the probable reasons for transport of Pho3p and Pho5p/Pho10p/Pho11p enzymes by two different kinds of vesicles, we isolated vesicles from strains that synthesize the homomeric forms of the repressible acid phosphatase. It was demonstrated that glycoproteins encoded by the PHO10 and/or PHO11 genes could be responsible for the choice of one of the alternative transport pathways of the repressible acid phosphatase. A high correlation coefficient between bud formation and secretion of Pho5p phosphatase and the absence of correlation between bud formation and secretion of minor phosphatases Pho10p and Pho11p suggests different functional roles of the polypeptides that constitute the native repressible acid phosphatase.     

Heterogeneity of streptococcus group A cell wall protein components

Cell wall surface proteins of group A streptococcus (M 29) were isolated by mild chemical extraction with 1 M hydroxylamine pH 6.0 (37 degrees C). The proteins were purified by ammonium sulfate fractionation, gel filtration on Sephadex G-150 and ion-exchange chromatography on DEAE-Trisacryl M. Using two independent methods (disc electrophoresis in 7.5% PAAG pH 8.9 and high pressure gel filtration), it was shown that after chromatography on Sephadex G-150 the original protein fraction contains up to 8 protein components, while SDS-PAAG electrophoresis performed according to Laemmli revealed up to 25 protein components in the same fraction. During SDS-PAAG electrophoresis six protein fractions performed after ion-exchange chromatography were resolved into 40 protein components whose molecular masses vary from 13 to 80 kDa. Possible reasons for the heterogeneity of surface proteins of group A streptococcus cell wall are discussed.     

Olive Phenolics as c-Met Inhibitors: (-)-Oleocanthal Attenuates Cell Proliferation,Invasiveness, and Tumor Growth in Breast Cancer Models

Dysregulation of the Hepatocyte growth factor (HGF)/c-Met signaling axis upregulates diverse tumor cell functions, including cell proliferation, survival, scattering and motility, epithelial-to-mesenchymal transition (EMT), angiogenesis, invasion, and metastasis. (-)-Oleocanthal is a naturally occurring secoiridoid from extra-virgin olive oil, which showed antiproliferative and antimigratory activity against different cancer cell lines. The aim of this study was to characterize the intracellular mechanisms involved in mediating the anticancer effects of (-)-oleocanthal treatment and the potential involvement of c-Met receptor signaling components in breast cancer. Results showed that (-)-oleocanthal inhibits the growth of human breast cancer cell lines MDA-MB-231, MCF-7 and BT-474 while similar treatment doses were found to have no effect on normal human MCF10A cell growth. In addition, (-)-oleocanthal treatment caused a dose-dependent inhibition of HGF-induced cell migration, invasion and G1/S cell cycle progression in breast cancer cell lines. Moreover, (-)-oleocanthal treatment effects were found to be mediated via inhibition of HGF-induced c-Met activation and its downstream mitogenic signaling pathways. This growth inhibitory effect is associated with blockade of EMT and reduction in cellular motility. Further results from in vivo studies showed that (-)-oleocanthal treatment suppressed tumor cell growth in an orthotopic model of breast cancer in athymic nude mice. Collectively, the findings of this study suggest that (-)-oleocanthal is a promising dietary supplement lead with potential for therapeutic use to control malignancies with aberrant c-Met activity.     

POTENTIATION OF CAFFEINEINDUCED CONTRACTURE BY RAISING EXTRACELLULAR POTASSIUM IN FROG SKELETAL MUSCLE

用蛙胫前肌小束为材料,研究了提高胞外钾［Ｋ＋］Ｏ对咖啡因挛缩的作用。［Ｋ＋］Ｏ从２ｍｍｏｌ／Ｌ提高到１０或２５ｍｍｏｌ／Ｌ,由３ｍｍｏｌ／Ｌ咖啡因引起的挛缩明显增强。以ＰＫＣ／ＰＣ（ＰＫＣ和ＰＣ分别为在高钾和正常钾条件下的咖啡因挛缩）表示的咖啡因挛缩增强,依赖［Ｋ＋］Ｏ和高钾作用时间。随着１０ｍｍｏｌ／Ｌ［Ｋ＋］Ｏ作用时间延长,直至１０ｍｉｎ,增强逐渐增加。但是,２５ｍｍｏｌ／Ｌ［Ｋ＋］Ｏ作用１ｍｉｎ时增强达到最大,然后下降到对照。ＰＫＣ／ＰＣ变化时程不能用高钾引起的去极化解释,而与由相似［Ｋ＋］Ｏ引起的胞浆自由钙变化时程相符。提示,至少在蛙骨骼肌,高钾引起的咖啡因挛缩增强主要是由胞浆自由钙升高引起的。