Glucose oxidase immobilization on a novel cellulose acetate-polymethylmethacrylate membrane

Glucose oxidase (GOD) was immobilized on cellulose acetate-polymethylmethacrylate (CA-PMMA) membrane. The immobilized GOD showed better performance as compared to the free enzyme in terms of thermal stability retaining 46% of the original activity at 70 degrees C where the original activity corresponded to that obtained at 20 degrees C. FT-IR and SEM were employed to study the membrane morphology and structure after treatment at 70 degrees C. The pH profile of the immobilized and the free enzyme was found to be similar. A 2.4-fold increase in Km value was observed after immobilization whereas Vmax value was lower for the immobilized GOD. Immobilized glucose oxidase showed improved operational stability by maintaining 33% of the initial activity after 35 cycles of repeated use and was found to retain 94% of activity after 1 month storage period. Improved resistance against urea denaturation was achieved and the immobilized glucose oxidase retained 50% of the activity without urea in the presence of 5M urea whereas free enzyme retained only 8% activity.     

Multiple,independently regulated pathways of cholesterol transport across the intestinal epithelial cells

The present study provides a new understanding about the mechanisms involved in cholesterol absorption by the intestinal cells. Contrary to general belief, our data show that newly absorbed cholesterol is neither immediately available for secretion with apoB lipoproteins nor exclusively secreted as part of chylomicrons. Based on our data, cholesterol transport by enterocytes can be broadly classified into two independently modulated, apoB-dependent and -independent, pathways. Cholesterol secretion by the apoB-dependent pathway is induced by oleic acid, is repressed by microsomal triglyceride transfer protein inhibitors, and occurs only with larger apoB-containing lipoproteins. ApoB-independent pathways do not require microsomal triglyceride transfer protein and involve efflux mediated by ABCA1, high density lipoprotein assembly, and possibly other unknown mechanisms. There are at least two different metabolic pools of cholesterol. The newly absorbed and pre-absorbed cholesterol are preferentially secreted via apoB-independent and apoB-dependent pathways, respectively. In contrast to compartmentalization for secretion, these two metabolic pools are equally accessible for cellular esterification. The esterified cholesterol is mainly secreted by the apoB-dependent pathway, whereas both the pathways are involved in the secretion of free cholesterol. Thus, enterocytes transport exogenous cholesterol by several independently regulated pathways raising the possibility that targeting of apoB-independent pathways may result in selective inhibition of cholesterol transport without affecting triglyceride transport.     

新疆博格达山岩面生地衣群落结构特征

根据对新疆博格达山岩面生地衣群落20个样点(20m×20m)调查的数据,以各地衣种的盖度为指标结合双向指示种分析方法(TWINSPAN)和除趋势对应分析法(DCA)对博格达山岩面生地衣群落进行数量分类并分析了群落结构特征及其多样性和相似性。采用典范对应分析法(CCA)对各群落的物种分布格局与环境因子的关系进行研究。结果表明,TWINSPAN分析和DCA排序将分布在博格达山的37种岩面生地衣分为以下5个群丛。群丛1:斑纹网衣(Lecidea tessellate Florke)+粉芽盾衣(Peltula euploca(Ach.)Poelt)+杜瑞氏黄梅(Xanthoparmelia durietzii Hale)群丛,有25个种,总覆盖度为30.145%,多样性为4.025;群丛2:袋衣(Hypogymnia physodes(L.)Nyl.)+白边平茶渍(Aspicilia sublaqueata(H.Magn.)J.C.Wei)+砖孢胶衣(Collema subconveniens Nyl.)群丛,有17个种,地衣总盖度为15.885%,多样性为3.196;群丛3:聚茶渍(Lecanora accumulate H.Magn.)+丽石黄衣(Xanthoria elegans(Link)Th.Fr.)+亚洲平茶渍(Aspicilia asiatica(H.Magn.)Yoshim.)群丛,有30个种,地衣总盖度为37.87%,多样性为4.357;群丛4:中华石果衣(Endocarpon sinense H.Magn.)+伴藓大孢蜈蚣衣(Physconia muscigena(Ach.)Poelt.)+垫脐鳞衣(Rhizoplaca melanophthalma(DC.)LeuckertPoelt)群丛,有24个种,地衣总盖度为30.458%,多样性为3.912;群丛5:石胶衣(Collema flaccidum(Ach.)Ach.)+短绒皮果衣(Dermatocarpon vellereum Zschacke)+绿黑地图衣(Rhizocarpon viridiatrum(Wulfen)Korber.)群丛,有18个种,地衣总盖度为19.331%,多样性为3.515。CCA排序结果反映,该地区岩面生地衣的分布与海拔高度、光照强度、岩石pH和人为干扰有关,其中影响最大的因素是海拔高度,其次为光照强度和干扰。坡向和岩石大小对地衣种类分布的影响不显著。     

Breeding Potential of Some Exotic Tomato Lines: A Combined Study of Morphological Variability,Genetic Divergence,and Association of Traits

Tomato (Solanum lycopersicum L.) is called ‘the poor man’s orange’ due to its low price and improved nutritional values. An experiment was conducted to study the breeding potential of some exotic tomato lines by assessing various qualitative and quantitative traits conferring yield and quality attributes. Among the qualitative traits, greater variability was observed for growth type, stem hairiness, and fruit shape and size. A determinate growth habit was observed in the genotype AVTO9802 while the genotype AVTO0102 produced yellow color fruits. A significant (p ≤ 0.01) variation was also observed for the studied quantitative traits. Based on yield and traits attributed to yield, the genotypes AVTO0314, GPB0107, GPB0120 and AVTO9802 were selected as promising genotypes. The differences between the genotypic and phenotypic coefficients of variation (GCV and PCV) of the studied quantitative traits were very low. This suggests that the apparent variation was mainly due to the genotypes. The higher GCV and PCV values were observed for the number of primary branches plant⁻¹ (NPB), number of fruits cluster⁻¹ (NFC), individual fruit weight (IFW) and total soluble solids (TSS). High heritability was recorded for all quantitative traits in a broad sense. However, the individual fruit diameter showed the highest heritability (99.56). The highest (102.75) genetic advance (GA) was observed for the number of fruits plant⁻¹ (NFP). High heritability coupled with high GA as percentage of mean were recorded for the traits NFP, NFC, fruit yield plant⁻¹ (FYP) and IFW. FYP showed a significant positive correlation with NFC (0.714***) and a negative correlation with days to the first harvest (−0.539***) and plant height (−0.492**). Principal component analysis revealed that the first four components explained 78.5% of the total variation among the genotypes. Thus, the promising genotypes (AVTO0314, GPB0107, GPB0120, AVTO9802 and AVTO0102) isolated from this study can be used for developing high-yielding and high-quality tomato varieties.     

Angiotensin-(1–7) Via the Mas Receptor Alleviates the Diabetes-Induced Decrease in GFAP and GAP-43 Immunoreactivity with Concomitant Reduction in the COX-2 in Hippocampal Formation: An Immunohistochemical Study

We have previously shown that chronic treatment with angiotensin-(1?C7) [Ang-(1?C7)] can prevent diabetes-induced cardiovascular dysfunction. However, effect of Ang-(1?C7) treatment on diabetes-induced alterations in the CNS is unknown. The aim of this study was to test the hypothesis that treatment with Ang-(1?C7) can produce protection against diabetes-induced CNS changes. We examined the effect of Ang-(1?C7) on the number of cyclooxygenase-2 (COX-2) immunoreactive neurons and the glial fibrillary acidic protein (GFAP)-immunoreactive astrocytes and assessed the changes in the neuronal growth-associated protein-43 (GAP-43) of the hippocampal formation in streptozotocin-induced diabetes in rats. Animals were sacrificed 30?days after induction of diabetes and/or treatment with Ang-(1?C7). Ang-(1?C7) treatment significantly prevented diabetes-induced decrease in the number of GFAP immunoreactive astrocytes and GAP-43 positive neurons in all hippocampal regions. Co-administration of A779, a selective Ang-(1?C7) receptor antagonist, inhibited Ang-(1?C7)-mediated protective effects indicating that Ang-(1?C7) produces its effects through activation of receptor Mas. Further, Ang-(1?C7) treatment through activation of Mas significantly prevented diabetes-induced increase in the number of the COX-2 immunolabeled neurons in all sub-regions of the hippocampus examined. These results show that Ang-(1?C7) has a protective role against diabetes-induced changes in the CNS.     

Tricellulin is a tight-junction protein necessary for hearing

The inner ear has fluid-filled compartments of different ionic compositions, including the endolymphatic and perilymphatic spaces of the organ of Corti; the separation from one another by epithelial barriers is required for normal hearing. TRIC encodes tricellulin, a recently discovered tight-junction (TJ) protein that contributes to the structure and function of tricellular contacts of neighboring cells in many epithelial tissues. We show that, in humans, four different recessive mutations of TRIC cause nonsyndromic deafness (DFNB49), a surprisingly limited phenotype, given the widespread tissue distribution of tricellulin in epithelial cells. In the inner ear, tricellulin is concentrated at the tricellular TJs in cochlear and vestibular epithelia, including the structurally complex and extensive junctions between supporting and hair cells. We also demonstrate that there are multiple alternatively spliced isoforms of TRIC in various tissues and that mutations of TRIC associated with hearing loss remove all or most of a conserved region in the cytosolic domain that binds to the cytosolic scaffolding protein ZO-1. A wild-type isoform of tricellulin, which lacks this conserved region, is unaffected by the mutant alleles and is hypothesized to be sufficient for structural and functional integrity of epithelial barriers outside the inner ear.     

Positive and negative modulation of Bombyx mori adenylate cyclase by 5-phenyloxazoles: identification of octopamine and tyramine receptor agonists

Nineteen 5-phenyloxazoles (5POs) were examined for their ability to modulate adenylate cyclase by measuring cAMP produced in head membrane homogenates of fifth instar larvae of the silkworm Bombyx mori. Among the compounds tested, 5-(4-methoxyphenyl)oxazole (9) and the 2,6-dichlorophenyl congener showed the highest activation of adenylate cyclase; both compounds produced approximately half the level of cAMP produced by the action of octopamine (OCT). The OCT receptor antagonists chlorpromazine, mianserin, and metoclopramide attenuated 9-stimulated cAMP production. In contrast, 5-(4-hydroxyphenyl)oxazole (8) and the 4-cyanophenyl congener attenuated both OCT-stimulated and basal cAMP production. The tyramine (TYR) receptor antagonist yohimbine inhibited the negative effect of 8. These findings indicate that the 5PO class of compounds includes both positive and negative modulators of adenylate cyclase in the heads of B. mori larvae, and that 9 and 8 are OCT and TYR receptor agonists, respectively. These compounds might prove useful for a pharmacological dissection of biogenic amine receptors.     

A nuclease‐toxin and immunity system for kin discrimination in Myxococcus xanthus

The use of toxin to attack neighbours and immunity proteins to protect against toxin has been observed in bacterial conflicts, including kin discrimination. Here, we report a novel nuclease‐toxin and its immunity protein function in the colony‐merger incompatibility, a kind of bacterial kin discrimination, in Myxococcus xanthus DK1622. The MXAN_0049 gene was determined to be a genetic determinant for colony‐merger incompatibility, and the incompatibility could be eliminated by deletion of the upstream co‐transcribed MXAN_0050 gene. We demonstrated that the MXAN_0050 protein was a nuclease, and MXAN_0049 protein was able to bind to MXAN_0050 to block nuclease activity in vitro. Expression of MXAN_0050 in Escherichia coli inhibited cellular growth, and the inhibition effect could be recovered by co‐expression of MXAN_0049. We found that deletion of the PAAR‐encoding gene (MXAN_0044) or the type VI secretion system led to the colony‐merger and co‐existence with the ΔMXAN_0049 mutant, suggesting that they were associated with colony‐merger incompatibility. Homologues of the nuclease‐toxin and cognate immunity pair are widely distributed in bacteria. We propose a simplified model to explain the kin discrimination mechanism mediated by the nuclease‐toxin and immunity protein.© 2018 Society for Applied Microbiology and John Wiley & Sons Ltd     

Potential of bacterial culture media in biofabrication of metal nanoparticles and the therapeutic potential of the as-synthesized nanoparticles in conjunction with artemisinin against MDA-MB-231 breast cancer cells

In the recent past, various groups have proposed diverse biocompatible methods for the synthesis of metal nanoparticles (NPs). Besides culture biomass, culture supernatants (CS) are increasingly being explored for the synthesis of NPs; however, with the ever-increasing exploration of various CS in the biofabrication of NPs, it is equally important to explore the potential of various culture media (CMs) in the synthesis of metal NPs. Considering these aspects, in the present investigation, we explore the possible applicability of various CMs in the biofabrication of metal NPs. The synthesis of NPs was primarily followed by UV/VIS spectroscopy, and, thereafter, the NPs were characterized by various physiochemical techniques, including EM, EDX, FT_IR, X-ray diffraction, and DLS measurements, and finally, their anticancer potentialities were investigated against breast cancer. In addition, the NPs were examined in conjunction with artemisinin for therapeutic benefits against aggressive and highly metastatic MDA-MB-231 breast cancer cells. Cumulatively, the results of the present study collated the potentials of various bacterial CMs in the biofabrication of metal NPs and ascertained the efficacy of the as-synthesized silver nanoparticles, especially the combinatorial entity as intriguing breast cancer therapeutics. The data of the present study plausibly assist in advancing the therapeutic applicability of the combinatorial amalgam against aggressive and highly metastatic MDA-MB-231 breast cancer cells.