Enzymatic degradation of cell wall polysaccharides from soybean meal

Soybean meal, soybean water unextractable solids (WUS) and extracts thereof, which contain particular cell wall polysaccharides, were incubated with a number of cell wall degrading enzymes. The intact cell wall polysaccharides in the meal and WUS were hardly degradable, while the extracts from WUS were well degraded. The arabinogalactan side chains in the pectin-rich ChSS fraction (Chelating agent Soluble Solids) could to a large extent be removed from the pectins by the combined action of endo-galactanase, exo-galactanase, endo-arabinanase and arabinofuranosidase B. The remaining polymer was isolated and represented 30% of the polysaccharides in the ChSS fraction. Determination of the sugar composition showed these polymers to be very highly substituted pectic structures. It still contained 5 mol% of arabinose and 12 mol% of galactose, representing 7% and 12%, respectively, of the arabinose and galactose present in the ChSS fraction before degradation. Further, the presence of uronic acid (50 mol%) and of xylose (18 mol%) indicated the presence of a xylogalacturonan.     

Attachment of group B streptococci to macrophages is mediated by a 21-kDa protein

Group B Streptococcus (GBS) is able to bind to human macrophages in vitro in the absence of exogenous opsonins. The exact mechanisms that mediate this attachment are unclear. This study was undertaken to determine what protein adhesins are present on the surface of GBS that mediate attachment to macrophages. We have identified a 21-kDa protein from the envelope of GBS type III that directly binds to macrophages as determined by Western blot analysis. Antiserum against this protein was able to inhibit binding of GBS to macrophages by greater than 80% as measured by flow cytometry. Antiserum against the 21-kDa protein cross-reacted with 21-kDa proteins from GBS type Ib, type II, type III (COH31 and MR732) and type IV, as well as Staphylococcus epidermidis , but not GBS type Ia, Listeria monocytogenes or Enterococcus faecalis . This protein may be important in mediating the attachment of GBS to macrophages in an opsonin-poor environment.     

The robustness of altruism as an evolutionary strategy

Kin selection, reciprocity and group selection are widely regarded as evolutionary mechanisms capable of sustaining altruism among humans andother cooperative species. Our research indicates, however, that these mechanisms are only particular examples of a broader set of evolutionary possibilities.In this paper we present the results of a series of simple replicator simulations, run on variations of the 2–player prisoner's dilemma, designed to illustrate the wide range of scenarios under which altruism proves to be robust under evolutionary pressures. The set of mechanisms we explore is divided into four categories:correlation, group selection, imitation, and punishment. We argue that correlation is the core phenomenon at work in all four categories.     

The history of Hayek’s theory of cultural evolution

This paper traces the historical origins of Friedrich A. Hayek’s theory of cultural evolution, and argues that Hayek’s evolutionary thought was significantly inspired by Alexander M. Carr-Saunders and Oxford zoology. While traditional Hayek scholarship emphasizes the influence of Carl Menger and the British eighteenth-century moral philosophers, I claim that these sources underdetermine what was most characteristic of Hayek’s theory, viz. the idea that cultural evolution is a matter of group selection, and the idea that natural selection operates on acquired as well as on inherited properties.     

Unveiling novel diphenyl-1H-pyrazole based acrylates tethered to 1,2,3-triazole as promising apoptosis inducing cytotoxic and anti-inflammatory agents

Meagre and suboptimal therapeutic response along with the side effect profile associated with the existing anticancer therapy have necessitated the development of new therapeutic modalities to curb this disease. Bearing in mind the current scenario, a series of 1,2,3-triazole linked 3-(1,3-diphenyl-1H-pyrazol-4-yl)acrylates was synthesized following a multi-step reaction scheme. Initial screening for anticancer potential was done by in vitro sulforhodamine B assay against four human cancer cell lines- MCF-7 (breast), A549 (Lung) and HCT-116 and HT-29 (Colon). On evaluation, several compounds showed promising growth inhibition against all the cell lines, particularly compounds 6e, 6f and 6n. Among them, compound 6f displayed IC₅₀ values of 1.962, 3.597, 1.764 and 4.496 µM against A549, HCT-116, MCF-7 and HT-29 cell lines respectively. Furthermore, the apoptosis inducing potential of the compounds was determined by Hoechst staining and DNA fragmentation assay. Colony formation inhibition assay was also carried out to determine the long term cytotoxic potential of the molecules. Moreover, compounds 6e, 6f and 6n were also evaluated for anti-inflammatory activity by protein albumin denaturation assay and red blood cell membrane stabilizing assay.     

Variation in piglet body weight gain and feed intake during a 9-week lactation in a multi-suckling system

A multi-suckling (MS) system for sows and piglets has been developed aiming to improve animal welfare. In this system, large variation in BW gain exists between piglets up to weaning at 9 weeks of age. We aimed to study the causes of variation in BW gain and DM intake of solid feed (DFI) (piglet + sow feed) of piglets during lactation in the MS system. A total of 15 sows and 60 focal piglets across three batches were studied. Individual intake of piglet and sow feed was measured by the dual marker method, and multiple variables were recorded. Multiple linear regression analysis with forward selection was conducted on BW gain and DFI after correcting for piglet sex and batch, using multiple explanatory variables including genetic background, birthweight (BiW), DM feed intake, behaviours and number of skin lesions. These factors jointly explained less than 45 % and 21 % of the variation in BW gain and DFI, respectively. In weeks 2–4, variation in BW gain was mainly explained by BiW (12.0 %) and play and nosing behaviours (7.6 %). In weeks 4–6 and 6–8, it was largely explained by DM intake of piglet feed with 15.1 % and 25.9 %, respectively. Individual variation in DFI in weeks 2–4 was explained by the presence at front and middle teats during suckling bouts (2.9 %), in weeks 4–6 by BiW (9.6 %), and in weeks 6–8 by the number of skin lesions (5.1 %). The unexplained variation in BW gain and DFI warrants further investigation.     

反相高效液相层析在胰岛素结构与功能研究中的应用

采用一种简单的“甲醇-水-0.1％三氟醋酸”作为洗脱体系的反相高效液相层析对研究胰岛素结构与功能关系,以及A链和B链相互作用时所用的一些胰岛素衍生物进行了快速、灵敏、准确的分析和鉴定。 胰岛素的S-磺酸型A链和B链只经一次离子交换层析纯化,经鉴定结果表明是均一的。S-硫甲基型A链和B链基本上也是均一的。通过对胰岛素还原产物的分析确定了能保证胰岛素折分完全并对其重组较为有利的还原条件。去B链羧端五肽(B26—30)胰岛素,以及去B链羧端八肽(B23—30)胰岛素能同时与天然胰岛素清楚地分离。一级结构差别极小的猪胰岛素和牛胰岛素也可得到分辨。胰岛素的羧端缩短的B链和A链重组的定量分析表明B链羧端肽段不但对胰岛素分子的生物活力的体现,而且在A链和B链的正确重组中都起着重要的作用。     

WHO Study Group on cell substrates for production of biologicals, Geneva, Switzerland, 11–12 June 2007

For many years, the World Health Organization (WHO) has provided global leadership in defining technical specifications for quality assurance and safety of biological medicines produced in cell substrates. Current WHO requirements for the use of animal cells as substrates for production of vaccines and other biologicals were adopted by the WHO Expert Committee on Biological Standardization in 1996 (WHO TRS 878). Since then, significant progress especially in the development of vaccines in novel continuous cell lines of mammalian origin as well as in insect cells has been made and consequently there is an increasing need for the re-evaluation of existing criteria for the acceptability of such cell lines. In addition there is also a need to consider new issues in cell substrate safety arising from these new cell types and developments in technology and scientific knowledge. In response to these demands, the WHO Study Group on Cell Substrates was formed in 2006 to initiate revision of WHO requirements and to address the need for further research in this area. At its second meeting on 11-12 June 2007, the Study Group reviewed scientific data that would form the basis for new recommendations and made a number of proposals for further investigations. The Study Group is working on the preparation of a revised WHO document, and a broad consultation with regulators, manufacturers, and other relevant parties is planned for 2008.     

喜马拉雅前陆盆地中新世-上新世SIWALIK-CHURIA群轮藻化石及其古生物地理和古生态意义

印度、尼泊尔晚中新世-上新世SIWALIK-CHURIA群轮藻化石组合与中国塔里木盆地及哈萨克斯坦东南部伊犁盆地轮藻组合极为接近。据此讨论了它们的古生物地理和古生态学特征。中新世-上新世轮藻植物繁盛的原因与当时季风活动引起的季节性洪水泛滥,在广大河漫滩地上形成有利于轮藻植物生长发育的局部湖泊环境有关。