Combined effect of alcohol and cigarette smoke on lipid peroxidation and antioxidant status in rats

The effect of long-term administration of alcohol and cigarette smoke independently and both in combination on lipid peroxidation and antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione-S-transferase (GST) was studied in liver, kidney, heart and lungs of albino rats. The levels of peroxidation products viz., malondialdehyde, hydroperoxides and conjugated dienes were increased in all the tissues of alcohol administered and smoke-exposed rats. Activities of SOD and CAT were decreased in alcohol-treated and alcohol and smoke combination groups, but increased in smoke-exposed group. Activities of GPx and GST have shown an increase, while concentration of reduced glutathione was found decreased in all the three groups.     

Allosteric site-mediated active site inhibition of PBP2a using Quercetin 3-O-rutinoside and its combination

Recent crystallographic study revealed the involvement of allosteric site in active site inhibition of penicillin binding protein (PBP2a), where one molecule of Ceftaroline (Cef) binds to the allosteric site of PBP2a and paved way for the other molecule (Cef) to bind at the active site. Though Cef has the potency to inhibit the PBP2a, its adverse side effects are of major concern. Previous studies have reported the antibacterial property of Quercetin derivatives, a group of natural compounds. Hence, the present study aims to evaluate the effect of Quercetin 3-o-rutinoside (Rut) in allosteric site-mediated active site inhibition of PBP2a. The molecular docking studies between allosteric site and ligands (Rut, Que, and Cef) revealed a better binding efficiency (G-score) of Rut (?7.790318) and Cef (?6.194946) with respect to Que (?5.079284). Molecular dynamic (MD) simulation studies showed significant changes at the active site in the presence of ligands (Rut and Cef) at allosteric site. Four different combinations of Rut and Cef were docked and their G-scores ranged between ?6.320 and ?8.623. MD studies revealed the stability of the key residue (Ser403) with Rut being at both sites, compared to other complexes. Morphological analysis through electron microscopy confirmed that combination of Rut and Cefixime was able to disturb the bacterial cell membrane in a similar fashion to that of Rut and Cefixime alone. The results of this study indicate that the affinity of Rut at both sites were equally good, with further validations Rut could be considered as an alternative for inhibiting MRSA growth.     

Population fluctuations of the diamondback moth,Plutella xylostella (L.) on cabbages inBacillus thuringiensis sprayed and non sprayed plots and factors affecting within-generation survival of immatures

Summary The population fluctuations and within-generation survival of immatures stages of the diamondback moth,Plutella xylostella on summer cabbages, were examined in unsprayed plots in 1984 and 1985 and in plots sprayed with two formulations ofBacillus thuringiensis in 1985. There was two distincy generations per crop and no noticeable difference in population fluctuations were observed in unsprayed plots between years. There was distinct difference between unsprayed and sprayed plots in 1985, from the larval period onwards. However, the survivorship patterns in all plots in both years were a Type 2 based onDeevey's (1947) classification. Life table studies showed that there was essentially no difference in the mortality agents acting on each of the stages except for numerical differences in the within-generation mortality rates. The major mortality rates during the egg stage were the parasitoid,Trichogramma spp. and unknown factors including rainfall; in the larval 1 stage was unknown mortality; in the larval 2 stage was the parasitoid,Apanteles plutellae and during the pupal stage was unknown mortality and parasitoid,Diadromus subtilicornis. Adult mortality was determined for generation 2. It was relatively higher in the unsprayed plots compared to theB. thuringiensis sprayed plots. The contribution of abiotic factors such as rainfall and temperature, and biotic factors such as parasitoids and predators in determining within-generation population levels and the fluctuation of populations on cabbage were discussed.     

An Efficient Protection-Free One-Pot Chemical Synthesis of Modified Nucleoside-5′-Triphosphates

A simple, reliable, and an efficient “one-pot, three step” chemical method for the synthesis of modified nucleoside triphosphates such as 5-methylcytidine-5′-triphosphate (5-MeCTP), pseudouridine-5′-triphosphate (pseudoUTP) and N¹-methylpseudouridine-5′-triphosphate (N¹-methylpseudoUTP) starting from the corresponding nucleoside is described. The overall reaction involves the monophosphorylation of nucleoside, followed by the reaction with pyrophosphate and subsequent hydrolysis of the cyclic intermediate to furnish the corresponding NTP in moderate yields with high purity (>99.5%).     

An Efficient Synthesis of Pyrimidine Specific 2′-Deoxynucleoside-5′-Tetraphosphates

An efficient chemical synthesis of pyrimidine specific 2′-deoxynucleoside-5′-tetraphosphates, such as 2′-deoxycytidine-5′-tetraphosphate (dC4P) and thymidine-5′-tetraphosphate (T4P) is described. The present three-step synthetic strategy involves monophosphorylation of 2′-deoxynucleoside using phosphorous oxychloride, conversion of 5′-monophosphate into the corresponding imidazolide salt, followed by reaction with tris[tributylammonium] triphosphate leading to the 2′-deoxynucleoside-5′-tetraphosphate in good yields.     

Purification of a recombinant histidine-tagged lactate dehydrogenase from the malaria parasite,Plasmodium vivax,and characterization of its properties

Lactate dehydrogenase (LDH) of the malaria parasite, Plasmodium vivax (Pv), serves as a drug target and immunodiagnostic marker. The LDH cDNA generated from total RNA of a clinical isolate of the parasite was cloned into pRSETA plasmid. Recombinant his-tagged PvLDH was over-expressed in E. coli Rosetta2DE3pLysS and purified using Ni²⁺-NTA resin giving a yield of 25–30 mg/litre bacterial culture. The recombinant protein was enzymatically active and its catalytic efficiency for pyruvate was 5.4 × 10⁸ min^?1 M^?1, 14.5 fold higher than a low yield preparation reported earlier to obtain PvLDH crystal structure. The enzyme activity was inhibited by gossypol and sodium oxamate. The recombinant PvLDH was reactive in lateral flow immunochromatographic assays detecting pan- and vivax-specific LDH. The soluble recombinant PvLDH purified using heterologous expression system can facilitate the generation of vivax LDH-specific monoclonals and the screening of chemical compound libraries for PvLDH inhibitors.     

Altered dopamine transporter function and phosphorylation following chronic cocaine self-administration and extinction in rats

Cocaine binds with the dopamine transporter (DAT), an effect that has been extensively implicated in its reinforcing effects. However, persisting adaptations in DAT regulation after cocaine self-administration have not been extensively investigated. Here, we determined the changes in molecular mechanisms of DAT regulation in the caudate-putamen (CPu) and nucleus accumbens (NAcc) of rats with a history of cocaine self-administration, followed by 3 weeks of withdrawal under extinction conditions (i.e., no cocaine available). DA uptake was significantly higher in the CPu of cocaine-experienced animals as compared to saline-yoked controls. DAT V_max was elevated in the CPu without changes in apparent affinity for DA. In spite of elevated CPu DAT activity, total and surface DAT density and DAT-PP2Ac (protein phosphatase 2A catalytic subunit) interaction remained unaltered, although p-Ser- DAT phosphorylation was elevated. In contrast to the CPu, there were no differences between cocaine and saline rats in the levels of DA uptake, DAT V_max and K_m values, total and surface DAT, p-Ser-DAT phosphorylation, or DAT-PP2Ac interactions in the NAcc. These results show that chronic cocaine self-administration leads to lasting, regionally specific alterations in striatal DA uptake and DAT-Ser phosphorylation. Such changes may be related to habitual patterns of cocaine-seeking observed during relapse.     

Facile Protection-Free One-Pot Chemical Synthesis of Nucleoside-5′-Tetraphosphates

A new, straightforward, reliable, and convenient protection-free one-pot method for the synthesis of 2′-deoxynucleoside-5′-tetraphosphate and ribonucleoside-5′-tetraphosphate is reported. The present synthetic strategy involves the monophosphorylation of a nucleoside followed by reaction with tris-(tri-n-butylammonium) triphosphate and subsequent hydrolysis of the putative cyclic tetrametaphosphate intermediate to provide nucleoside-5′-tetraphosphate in moderate yield with high purity. A plausible mechanism is proposed to account for the formation of product.