Transbuccal Delivery of 5-Fluorouracil: Permeation Enhancement and Pharmacokinetic Study

The purpose of this study was to determine the effect of permeation enhancers on the transbuccal delivery of 5-fluorouracil (FU). The effect of permeation enhancers on in vitro buccal permeability was assessed using sodium deoxycholate (SDC), sodium dodecyl sulphate (SDS), sodium tauroglycocholate (STGC), and oleic acid and their concentrations for absorption enhancement were optimized. STGC appeared to be most effective for enhancing the buccal permeation of FU than the other enhancers. These enhancements by STGC were statistically significant (p < 0.05) compared to control. The order of permeation enhancement was STGC > SDS > SDC > oleic acid. Histological investigations were performed on buccal mucosa and indicated no major morphological changes. The enhancing effect of STGC on the buccal absorption of FU was evaluated from the mucoadhesive gels in rabbits. The absolute bioavailability of FU from mucoadhesive gels containing STGC increased 1.6-fold as compared to the gels containing no permeation enhancer. The mean residence time and mean absorption time considerably increased following administration of gel containing penetration enhancer compared with the gel without penetration enhancer.     

Synthesis enables identification of the cellular target of leucascandrolide A and neopeltolide

Leucascandrolide A and neopeltolide are structurally homologous marine natural products that elicit potent antiproliferative profiles in mammalian cells and yeast. The scarcity of naturally available material has been a significant barrier to their biochemical and pharmacological evaluation. We developed practical synthetic access to this class of natural products that enabled the determination of their mechanism of action. We demonstrated effective cellular growth inhibition in yeast, which was substantially enhanced by substituting glucose with galactose or glycerol. These results, along with genetic analysis of determinants of drug sensitivity, suggested that leucascandrolide A and neopeltolide may inhibit mitochondrial ATP synthesis. Evaluation of the activity of the four mitochondrial electron transport chain complexes in yeast and mammalian cells revealed cytochrome bc(1) complex as the principal cellular target. This result provided the molecular basis for the potent antiproliferative activity of this class of marine macrolides, thus identifying them as new biochemical tools for investigation of eukaryotic energy metabolism.     

Production of pectinolytic enzymes pectinase and pectin lyase by <Emphasis Type="Italic">Bacillus subtilis</Emphasis> SAV-21 in solid state fermentation

Pectin-degrading enzymes (pectinase and pectin lyase) were produced in solid state fermentation by Bacillus subtilis SAV-21 isolated from fruit and vegetable market waste soil of Yamuna Nagar, Haryana, India, and identified by 16S rDNA sequencing. Under optimized conditions, maximum production of pectinase (3315 U/gds) and pectin lyase (10.5 U/gds) was recorded in the presence of a combination of orange peel and coconut fiber (4:1), with a moisture content of 60% at 35 °C and pH 4.0 after 4 days and 8 days of incubation, respectively. Pectinase yield was enhanced upon supplementation with galactose and yeast extract, whereas pectin lyase production was unaffected by adding carbon and nitrogen source to the basal medium. Thus, B. subtilis SAV-21 can be exploited for cost-effective production of pectinase and pectin lyase using agro-residues.     

Behavioural and Electrophysiological Responses of Mosquito Vectors <Emphasis Type="Italic">Aedes aegypti,Anopheles stephensi</Emphasis> and <Emphasis Type="Italic">Culex quinquefasciatus</Emphasis> to an Ethyl Ester: Ethyl 2-aminobenzoate

Mosquito control using different methods remains an integral component of intervention programmes which aim to protect humans from various mosquito-borne diseases. The host seeking behaviour of mosquitoes is essentially guided by odorant receptor neurons housed in the antenna, maxillary palps and proboscis. The odorant receptor neurons are responsible for detecting chemical cues from hosts and also useful for developing sustainable mosquito-control strategies that exploit host-seeking behaviours. The present investigation evaluates host seeking behavioural responses of a novel, non-toxic and environment friendly repellent, ethyl 2-aminobenzoate against three known vector species of mosquitoes viz. Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus maintained in laboratory. The flight orientation of the test mosquitoes was studied using Y-tube olfactometer, whereas the antennae of adult female mosquitoes were used to investigate the effect of ethyl 2-aminobenzoate on the peripheral olfactory system using electroantennogram (EAG). The findings demonstrate that ethyl 2-aminobenzoate exhibited significant response in Y-tube olfactometer against all the three known vector species of mosquitoes. However, only Anopheles stephensi significantly elicited responses in EAG experiments, while the responses obtained for Aedes aegypti and Culex quinquefasciatus were not statistically significant. The results conclude that currently evaluated chemical ethyl 2-aminobenzoate has potential against some well established mosquito vector species and could be exploited to develop new and comparatively more effective anti-mosquito formulations.     

Parataxonomy and palaeobiogeographic significance of dinosaur eggshell fragments from the Upper Cretaceous strata of the Cauvery Basin,South India

Abstract

In the past, fossilised dinosaur eggshells have been extensively documented from the Upper Cretaceous Lameta Formation of Central India and as many as nine oospecies are known at present from this formation. Compared to this, only one dinosaur oospecies has been described from the Cretaceous succession of the Cauvery Basin. However, the first fossil egg from India, identified as a chelonian egg, was documented from the Aptian – Albian Karai Formation of the Cauvery Basin in 1957. Following this, a solitary titanosaurid dinosaur egg was described from the Upper Cretaceous (Lower Maastrichtian) Kallankuruchhi Formation, Cauvery Basin in 1996. More recently, we have recovered isolated eggshell fragments from the marine part of the Upper Cretaceous (Late Maastrichtian) Kallamedu Formation. Based on eggshell morphology, microstructure and ultrastructure, these eggshell fragments are assigned to the oospecies Fusioolithus baghensis. The new find from the Cauvery Basin is important from palaeobiogeographic point of view as the oofamily Fusioolithidae is found in the Upper Cretaceous strata of India, France, Argentina and Morocco. Based on the common occurrence of similar oospecies in South America, Africa, Europe and India, a Late Cretaceous palaeobiogeographic connection between India and South America as well as Europe via Africa is suggested.     

Novel Promoters Derived from Chinese Hamster Ovary Cells via In Silico and In Vitro Analysis

For the industrial production of recombinant proteins in mammalian cell lines, a high rate of gene expression is desired. Therefore, strong viral promoters are commonly used. However, these have several drawbacks as they override cellular responses, are not integrated into the cellular network, and thus can induce stress and potentially epigenetic silencing. Endogenous promoters potentially have the advantage of a better response to cellular state and thus a lower stress level by uncontrolled overexpression of the transgene. Such fine‐tuning is typically achieved by endogenous enhancers and other regulatory elements, which are difficult to identify purely based on the genomic sequence. Here, Chinese hamster ovary (CHO) endogenous promoters and enhancers are identified using histone marks and chromatin states, ranked based on expression level and tested for normalized promoter strength. Successive truncation of these promoters at the 5′‐ and 3′‐end as well as the combination with enhancers are identified in the vicinity of the promoter sequence further enhance promoter activity up to threefold. In an initial screen within stable cell lines, the strongest CHO promoter appears to be more stable than the human cytomegalovirus promoter with enhancer, making it a promising candidate for recombinant protein production and cell engineering applications. A deeper understanding of promoter functionality and response elements will be required to take full advantage of such promoters for cell engineering, in particular, for multigene network engineering applications.     

The N-terminus region of Drp1, a Rint1 family protein is essential for cell survival and its interaction with Rad50 protein in fission yeast S.pombe

BackgroundDefects in DNA repair pathway can lead to double-strand breaks leading to genomic instability. Earlier we have shown that S.pombe Drp1, a Rint1/Tip1 family protein is required for the recovery from DNA damage.MethodsVarious truncations of Drp1 protein were constructed and their role in DNA damage response and interaction with Rad50 protein has been studied by co-immunoprecipitation and pull-down assays.ResultsThe structural and functional analysis of Drp1 protein revealed that the N-terminus region of Drp1 is indispensable for the survival. The C-terminus truncation mutants, drp1C1Δ and drp1C2Δ exhibit temperature sensitive phenotype and are hypersensitive against DNA damaging agents with elevated level of Rad52-YFP foci at non-permissive temperature indicating the impairment for DNA damage repair pathway. The essential N-terminus region of Drp1 interacts with the C-terminus region of Rad50 and might be involved in influencing the MRN/X function. Small-angle X-ray (SAXS) analysis revealed three-domain like shapes in Drp1 protein while the C-terminus region of Rad50 exhibit unusual bulges. Computational docking studies revealed the amino acid residues at the C-terminus region of Rad50 that are involved in the interaction with the residues present at the N-terminal region of Drp1 indicating the importance of the N-terminal region of Drp1 protein.ConclusionsWe have identified the region of Drp1 and Rad50 proteins that are involved in the interaction and their role in the DNA damage response pathway has been analyzed.General significanceThe functional and structural aspects of fission yeast Drp1 protein and its interaction with Rad50 have been elucidated.     

Serum proteins among Dusads of Bihar

Horizontal starch gel electrophoresis has been employed for the detection of haptoglobin, transferrin and albumin phenotypes among 88 Dusads of Bihar. No variant of the haptoglobins or transferrins has been found in this sample, whereas one individual showed bisalbuminemia.