Attenuation of Zn-Induced Acute Pancreatitis in Wistar Rat Fed on Cu- and Mg- Enriched Modified Poultry Egg^{\Psi }

Zinc (Zn) consumption has increased in many populations either due to the increased intake of Zn-fortified foods as in the USA or in agricultural food stuffs as in some Indian states during the last decade. Its excessive intake has been reported to induce acute pancreatitis (AP) in many studies due to increase in oxidative stress that was further reported to cause Cu and Mg deficiencies. This led us to design a modified poultry egg (ME^Ψ) enriched with Cu and Mg along with other antioxidants, and its efficacy on Zn-induced AP was studied in male Wistar rats. In one set, the rats were fed on equacaloric semi-synthetic basal diet containing 20 mg Zn/kg diet (control, group I), and Zn-induced AP-I diet and AP-II diet containing 40 and 80 mg Zn/kg diet (groups II and III) for 180 days, respectively. In another set, the rats were initially fed on Zn-induced AP-I and AP-II diets for 90 days and then shifted to -mixed Zn-induced AP-I and AP-II diets in groups IIME and IIIME for another 90 days. At the end of the experiment, data displayed increased serum and urinary Zn, Cu, and Mg levels in groups II and III rats, which were reduced and approached closer to control group I after feeding in groups IIME and IIIME rats. Transmission electron microscopic studies of acinar cells revealed progressive dilation, vesicularization, and degeneration of endoplasmic reticulum (ER), and decrease in zymogen granules (ZG) in groups II and III rats in contrast to their curvilinear or concentric long parallel running cisternal profile of ER in control group I. The treatment of helped in the restoration of the ER profile and ZG number, approaching closer to the control group I. The degree of recovery was dependent upon the degree of toxicity caused by the amount of Zn given in the diet. The results of this study suggest that -mixed diet can protect the acinar cells from the deleterious effects of Zn by decreasing the oxidative stress. Indian patent application no. 2264/Del/2005.     

天然砂与修饰砂对病毒的吸附与去除

分别在不同pH、含有不同金属阳离子及腐殖酸的脱氯自来水与蒸馏水中,研究了砂与金属氢氧化物修饰砂吸附与去除Polivirus 1(PV1)和Bacteroides fragilis phage(B．fp)的不同效果。结果显示,天然砂吸附病毒效率随水体pH的降低而增加,但当砂表面经氧氧化铝、氢氧化铁沉积修饰后,却在中性pH具有较高的吸附率。金属阳离子可促进天然砂吸附病毒,并随其浓度和价态的增加而增加,但对修饰砂作用不明显。腐殖酸对砂及修饰砂吸附病毒的影响也不同,修饰砂吸附病毒不受腐殖酸的存在及其浓度影响,而天然砂会因腐殖酸的存在及其浓度的提高而降低吸附病毒效率。在任一实验条件下,砂与修饰砂在自来水中的吸附病毒效率高于在蒸馏水中的吸附效率,扫描电镜观察显示砂与修饰砂具有明显不同的表面结构特征,这是两者具有不同吸附效率的基础。从砂与修饰砂吸附PV1的效率高于B．fp的现象说明B．fp是一个更为合适的病毒去除指示生物。本实验结果表明了金属氢氧化物修饰砂可为传统的净水工艺提供高效的病毒去除过滤介质与途径。     

Uncoupling protein-2 accumulates rapidly in the inner mitochondrial membrane during mitochondrial reactive oxygen stress in macrophages

Uncoupling protein-2 (UCP2) is a member of the inner mitochondrial membrane anion-carrier superfamily. Although mRNA for UCP2 is widely expressed, protein expression is detected in only a few cell types, including macrophages. UCP2 functions by an incompletely defined mechanism, to reduce reactive oxygen species production during mitochondrial electron transport. We observed that the abundance of UCP2 in macrophages increased rapidly in response to treatments (rotenone, antimycin A and diethyldithiocarbamate) that increased mitochondrial superoxide production, but not in response to superoxide produced outside the mitochondria or in response to H₂O₂. Increased UCP2 protein was not accompanied by increases in ucp2 gene expression or mRNA abundance, but was due to enhanced translational efficiency and possibly stabilization of UCP2 protein in the inner mitochondrial membrane. This was not dependent on mitochondrial membrane potential. These findings extend our understanding of the homeostatic function of UCP2 in regulating mitochondrial reactive oxygen production by identifying a feedback loop that senses mitochondrial reactive oxygen production and increases inner mitochondrial membrane UCP2 abundance and activity. Reactive oxygen species-induction of UCP2 may facilitate survival of macrophages and retention of function in widely variable tissue environments.     

New Solid Supports Linking Nucleoside Scaffolds

Abstract

An easy and efficient strategy to obtain new nucleoside based solid supports in which the nucleoside moieties have been anchored to the solid support through the nucleobase is here proposed. A simple and efficient solid-phase synthesis of 5′ and 3′-derivatized uridine analogues has so been developed, following methodologies well established in organic chemistry.     

Synthesis and Antitumor Activity of N-Sulfonyl Derivatives of Nucleobases and Sulfonamido Nucleoside Derivatives

Abstract

The introduction of sulfonamido group on the C-2 position of pyrimidine nucleosides was achieved by ring opening of 2,2′- and 2,3′-anhydronucleosides. N-sulfonyl derivatives of nucleobases and sulfonamido derivatives of nucleosides were assayed for in vitro antitumor activity.     

Bayesian Insight into a Robust Test for Linear Contrast Based on Asymmetric Censored Samples

A robust test for linear contrast using modified maximum likelihood estimators based on symmetrically censored samples proposed by Tiku (1973, 1982a) is studied in this paper from the Bayesian point of view. The effects of asymmetric censoring on this testing procedure is investigated and a good approximation to its posterior distribution in this case is worked out. We also present an example which illustrates the method of obtaining the highest posterior density interval for the linear combination of the unknown location parameters.     

Regioselective Enzymatic Hydrolysis of 3',5'-DI-O-Acetylthymidine and Observation of a Surface Effect Due to Polystyrene

The selective enzymatic hydrolysis of 3',5'-di-O-acetylthyidine (1) was studied. The lipases from porcine pancreas and Aspergillus niger, and pig liver esterase, all catalysed selective hydrolysis of the 5'O-acetyl group, but the lipase from Candida cylindracea catalysed selective hydrolysis of the 3'-O-acetyl group. Highest selectivity, leading to essentially pure 3'-O-acetylthymidine, was achieved using porcine pancreatic lipase in dilute solution at pH 7.5. Provision of an artificial interface in the form of polystyrene beads led to a significant increase in the rate of hydrolysis, accompanied by a marked fall in selectivity. Other changes in the hydrolysis conditions, such as raising the concentration of substrate or adding cosolvent, also led to a fall in selectivity.     

Synthesis of 2-(3′-Azido- and 3′-Amino-3′-deoxy-β-D-ribofuranosyl)thiazole-4-carboxamide

Abstract

In view of biological activities of tiazofurin and azido or aminosugar nucleosides, novel azido- and amino-substituted tiazofurin derivatives (1 and 2) were efficiently synthesized starting from 1,2;5,6-di-O-isopropylidene-D-glucose.     

多孔陶瓷吸附固定纤维堆囊菌发酵制备埃博霉素

由纤维堆囊菌产生的埃博霉素具有极大药用价值,但因纤维堆囊菌液体环境中聚团非均匀生长限制了埃博霉素的大规模生产。借助多孔陶瓷的多孔结构,可为粘细菌提供固体附着生长面,提高埃博霉素产量。利用造孔剂法制备硅藻土基多孔陶瓷,在优化制备及改性条件后,当30目木屑造孔剂用量为2.5%(质量分数),7 MPa下制得的硅藻土基多孔陶瓷性能良好,孔径集中在5μm,比表面积为23.55 m2/g,孔隙率为32%,机械强度为10.2 MPa;经1.5 mol/L FeCl3改性的多孔陶瓷对纤维堆囊菌的吸附量达36.8 mg/g。在优化固定化发酵条件后,当在300 ml三角瓶中装液量为45 ml,固液比3:5,接种量10%,温度30℃,转速220 r/min,最初pH 7.5,发酵时间为8 d时,埃博霉素的产量达90.2 mg/L,与游离发酵相比提高了近4倍。     

Synthesis of Carbocyclic Analogues of MECA and NECA 1,2-Disubstituted as Potential Adenosine Receptor Agonists

Abstract

A new class of 1,2-disubstituted carbocyclic nucleosides of MECA and NECA analogues was synthesized in gool yield starting from (±) 6-azabicyclo[3.2.0]heptan-7-one.