Rate and mechanism of generation of beta 2-microglobulin mutants from a heterozygous murine cell line

Mutants that fail to express the B2mb allele can be readily isolated from a B2ma/b heterozygous cell line called R8 by a single step immunoselection protocol using a mAb against beta 2 microglobulin protein in the presence of complement. We present data that demonstrate that the mutants preexist the selection and arise at a rate of about 10(-6)/cell per generation. Southern blot analyses suggest that the mutants have lost the B2mb gene and the linked allele at the Emv-15 proviral integration site telomeric to the B2m locus. Surprisingly, the deletion of the first exon of the B2mb gene that is observed in other cell lines is not found in R8. Possible reasons for this observation are discussed.     

Thermal tolerance role of novel polyamine,caldopentamine, identified in fifth instar Bombyx mori

Silkworms have limited ability to regulate their body temperature; therefore, environmental changes, such as global warming, can adversely affect their viability. Polyamines have shown protection to various organisms against heat stress. This study evaluated the qualitative and quantitative changes in heat-stressed Bombyx mori larvae polyamines. Fifth instar Bombyx mori larvae were divided into two groups; control group, reared at room temperature, i.e., 28?±?2 °C, and the heat shock group, exposed to 40 °C. Dansylation of the whole worm polyamines and subsequent thin-layer chromatography revealed the presence of components with the same Rf value as dansyl–putrescine, spermidine, and spermine. The dansyl–putrescine, spermidine, and spermine polyamines were identified by mass spectrometric analyses. After heat shock, the thin-layer chromatography of the whole-larvae tissue extracts showed qualitative and quantitative changes in dansylated polyamines. A new polyamine, caldopentamine, was identified, which showed elevated levels in heat-stressed larvae. This polyamine could play a role in helping the larvae tolerate various stress, including thermal stress. No significant changes in silk fiber’s economic and mechanical properties were observed in our study. This study indicated that PA, caldopentamine, supplementation could improve heat-stress tolerance in Bombyx mori.

     

Localization of cellular retinol-binding protein mRNA in rat testis and epididymis and its stage-dependent expression during the cycle of the seminiferous epithelium

Anatomical localization of cellular retinol-binding protein (CRBP) mRNA was examined in normal rat testis and epididymis and also in retinoid-deficient rat testis. In situ hybridization was performed with 35S-labeled rat CRBP cRNA probes on frozen tissue sections. In normal testis, CRBP mRNA was mainly localized in the Sertoli cells and to some extent in peritubular cells. A distinct cyclic variation of the relative levels of hybridizable CRBP mRNA was observed during the spermatogenic cycle. The peak of CRBP mRNA content was seen in the stages of the cycle that preceded those in which peak CRBP protein content had been observed previously in our laboratory by immunohistochemistry. No appreciable amount of CRBP mRNA was observed in the interstitial space or in the lumen of the tubules. CRBP mRNA displayed the same anatomical localization in the retinoid-deficient testis, but the level of hybridizable CRBP mRNA was substantially reduced. A strong hybridization signal for CRBP mRNA was seen in proximal epididymis and was strikingly localized in the ductular epithelium. CRBP mRNA was not detectable in the distal portion of the epididymis. These studies provide information about the cell-specific expression of CRBP synthesis within the testis and epididymis and about its cyclic variation and regulation.     

Growth profile of rural Meitei children of Manipur state of India

Patterns of growth in 10 anthropometric measurements among the rural Manipuri children (N=425), aged 5 to 14 years, with poor socio-economic backgrounds are reported. The anthropometric dimensions include weight, stature, sitting-height, head, chest and midupper-arm circumferences, biepicondylar widths of humerus and femur, and triceps and biceps skinfolds. Except skinfolds, the boys measured more than the girls in all measurements at all ages, except from 10 to 12 years in weight, stature, sitting-height, and chest and mid-upper-arm circumferences. Across all ages, the girls had thicker fat folds. Up to 12 years, the children lie approximately on the 10th centile of NCHS in stature and weight. The arm circumferences was below the 3rd centile of the Dutch children, until 11 years. The triceps fat fold fluctuated between 10th and 25th centiles of US whites. The rural Meiteis were taller and heavier than rural Burmese and urban Meiteis. The overall growth performance of the rural Meitei children was poor as compared to US, Urban Chinese, and well-nourished Indian children.     

Bioanalytical chiral chromatographic technique and docking studies for enantioselective separation of meclizine hydrochloride: Application to pharmacokinetic study in rabbits

Enantiomeric resolution and molecular docking studies of meclizine hydrochloride on polysaccharide-based chiral stationary phase comprising cellulose tris(4-methylbenzoate) chiral selector (150 × 4.6 mm, 3.0 μm) were presented. The mobile phase used was acetonitrile:10mM ammonium bicarbonate (95:05, v/v). The developed technique was used to perform the enantioselective assay of meclizine hydrochloride in its marketed formulation. The elution order of meclizine hydrochloride enantiomers was determined by docking studies. Target compound was extracted from rabbit plasma using protein precipitation technique, followed by development of bioanalytical chiral separation method using the same matrix. Application of the method to determine pharmacokinetic parameters of meclizine hydrochloride enantiomers was performed using Phoenix WinNonlin 8.1 software. The results demonstrated stereoselective disposition of meclizine hydrochloride enantiomers in rabbits.     

Location of a gene conditioning seed coat colour in linseed (Linum usitatissimum L.) using chromosomal interchanges

The geneG, conditioning seed coat colour was found to be located at 15.37±3.05 map units from the breakage point of one of six newly induced interchanges in linseed. Since no information about the karyotype in linseed is available, the chromosome on whichG is located, cannot be specified.Part of a thesis submitted by the second author at the Indian Agricultural Research Institute, New Delhi, for a Ph.D. degree.     

A colorimetric assay for lignin based on its reaction with diazotized sulfanilic acid and its use in studies on lignin biodegradation by bacteria

Summary Studies on lignin biodegradation are considerably hampered by the lack of a simple analytical method. A rapid colorimetric assay for lignin has been developed using its reaction with a diazotized derivative of sulfanilic acid. Using such a method degradation of lignin, by an isolateErwinia sp. Cu3614, and by a genetically engineeredAcinetobacter PE7(pDPE2388) containing the arylether cleaving gene fromErwinia, has been followed.     

Vibrational spectroscopic studies of newly developed synthetic biopolymers

Vibrational spectroscopic techniques such as near‐infrared (NIR), Fourier transform infrared (FTIR), and Raman spectroscopy are valuable diagnostic tools that can be used to elucidate comprehensive structural information of numerous biological samples. In this review article, we have highlighted the advantages of nanotechnology and biophotonics in conjunction with vibrational spectroscopic techniques in order to understand the various aspects of new kind of synthetic biopolymers termed as polyethylene glycol (PEG)ylated lipids. In contrast to conventional phospholipids, these novel lipids spontaneously form liposomes or nanovesicles upon hydration, without the supply of external activation energy. The amphiphiles considered in this study differ in their hydrophobic acyl chain length and contain different units of PEG hydrophilic headgroups. We have further explored the thermotropic phase behaviors and associated changes in the conformational order/disorder of such lipids by using variable‐temperature FTIR and Raman spectroscopy. Phase transition temperature profiles and correlation between various spectral indicators have been identified by either monitoring the shifts in the vibrational peak positions or plotting vibrational peak intensity ratios in the C? H stretching region as a function of temperature. To supplement our observations of phase transformations, a thermodynamic approach known as differential scanning calorimetry (DSC) has been applied and revealed a good agreement with the infrared and Raman spectroscopic data. Finally, the investigation of thermal properties of lipids is extremely crucial for numerous purposes, thus the results obtained in this work may find application in a wide variety of studies including the development of PEGylated lipid based drug and substances delivery vehicles. © 2010 Wiley Periodicals, Inc. Biopolymers 93: 403–417, 2010. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com