Differential rates of sister chromatid exchanges between euchromatin and heterochromatin

In two rodent species, the Chinese hamster and the montane vole (Microtus montanus), the rate of sister chromatid exchange was lower in constitutive heterochromatin than in euchromatin.     

Harmful effects of 41 and 202 MHz radiations on some body parts and tissues

Many types of invisible electromagnetic waves are produced in our atmosphere. When these radiations penetrate our body, electric fields are induced inside the body, resulting in the absorption of power, which is different for different body parts and also depends on the frequency of radiations. Higher power absorption may result into health problems. In this communication, effects of electromagnetic waves (EMW) of 41 and 202 MHz frequencies transmitted by the TV tower have been studied on skin, muscles, bone and fat of human. Using international standards for safe exposure limits of specific absorption rate (SAR), we have found the safe distance from TV transmission towers for two frequencies. It is suggested that transmission towers should be located away from the thickly populated areas and people should keep away from the transmission towers, as they radiate electromagnetic radiations that are harmful to some parts/tissues of body.     

Enhancement of ethyl propionate synthesis by poly (AAc-co-HPMA-cl-MBAm)-immobilized Pseudomonas aeruginosa MTCC-4713, exposed to Hg2+ and NH4+ ions

A purified alkaline thermo-tolerant bacterial lipase from Pseudomonas aeruginosa MTCC-4713 was immobilized on a poly (AAc-co-HPMA-cl-MBAm) hydrogel. The hydrogel-bound lipase achieved 93.6% esterification of ethanol and propionic acid (300 mM: 100 mM) into ethyl propionate at temperature 65 degrees C in 3 h in the presence of a molecular sieve (3 angstroms). In contrast, hydrogel-immobilized lipase pre-exposed to 5 mM of HgCl2 orNH4Cl resulted in approximately 97% conversion of reactants in 3 h into ethyl propionate under identical conditions. The salt-exposed hydrogel was relatively more efficient in repetitive esterification than the hydrogel-bound lipase not exposed to any of the cations. Moreover, bound lipase exposed Hg2+ or NH4+ ions showed altered specificity towards p-nitrophenyl esters and was more hydrolytic towards higher C-chain p-nitrophenyl esters (p-nitrophenyl laurate and p-nitrophenyl palmitate with C 12 and C 16 chain) than the immobilized lipase not exposed to any of the salts. The later showed greater specificity towards p-nitrophenyl caprylate (C 8).     

Diversity and antimicrobial activity of endophytic fungi isolated from Nyctanthes arbor-tristis, a well-known medicinal plant of India

Endophytic fungi from Nyctanthes arbor-tristis were isolated and evaluated for their antimicrobial activity. A total of 19 endophytic fungi were isolated from 400 segments of healthy leaf and stem tissues of N. arbor-tristis. Eighteen endophytic fungi were obtained from leaf, while only ten from stem. Alternaria alternata had the highest colonization frequency (15.0%) in leaf, whereas Cladosporium cladosporioides ranked first in stem with a colonization frequency of 12%. The diversity and species richness were found higher in leaf tissues than in stem. The similarity indices between leaf and stem were 0.473 for Jaccard’s and 0.642 for the Sorenson index, respectively. Of 16, 12 (75%) endophytic fungal extracts showed antibacterial activity against either one or more pathogenic bacteria. The endophytic Nigrospora oryzae showed maximum inhibition against Shigella sp. and Pseudomonas aeruginosa. The leaf endophytes Colletotrichum dematium and Chaetomium globosum exhibited a broad range of anibacterial activity and were active against Shigella flexnii, Shigella boydii, Salmonella enteritidis, Salmonella paratyphi, and P. aeruginosa. Nine out of 16 (56.25%) endophytic fungi exhibited antifungal activity to one or more fungal pathogens. Colletotrichum dematium inhibited 55.87% of the radial growth of the phytopathogen Curvularia lunata. The antimicrobial activity of these endophytic microorganisms could be exploited in the biotechnological, medicinal, and agricultural industries.     

A comparative study of endophytic and epiphytic fungal association with leaf of <Emphasis Type="Italic">Eucalyptus citriodora</Emphasis> Hook., and their antimicrobial activity

Eucalyptus citriodora Hook, is frequently cultivated tree in India for its wood and medicinal usages. The endophytic and epiphytic fungi were estimated from healthy leaves of E. citriodora growing in the premise of Banaras Hindu University, Varanasi, India. A total of 33 fungal species were isolated from leaf segments. Of 33 taxa, 20 were recorded as endophytes, while 22 as epiphytes. Nine, out of 33 species were found to be common in leaf tissues and surfaces (Alternaria alternata, Aspergillus fumigatus, A. terreus, Cladosporium cladosporioides, Drechslera rostrata, Humicola grisea, Nigrospora oryzae, Penicillium cristata, and Pestalotia sp.). Out of 478 fungal isolates, 279 were epiphytic while only 199 were endophytic. Most isolates were anamorphic filamentous fungi which often don’t produce sexual spores. The Sorensen’s index of similarity between endophytes and epiphytes (leaf surface colonizers) was found to be at 0.300. Diversity index of fungal species was higher in endophytes than epiphytes. The frequency of colonization differs greatly in both myco-populations. Cladosporium cladosporioides (26%) was dominant species on leaf surfaces while Botrytis cinerea (10.5%) was dominant in leaf tissues. Out of 16 endophytic isolates evaluated for antagonistic test, 8 (50%) gave the antagonistic activity against variety of fungi representing pathogens to both humans and plants.     

Emergence of deciduous teeth in Punjabi children, north India.

Data on deciduous tooth emergence of 312 children aged 4 to 31 months of Punjabi parentage are presented. Probit analysis was used to derive the median age of tooth emergence. Female children are found to be advanced with respect to tooth emergence than their male counterparts. While comparing the present data with those from other populations it is found that, in general, the mean number of emerged teeth in Punjabi children is more at most ages, with lower median age of eruption for most teeth. Magnitude of interage variability in the eruption times is noticed to be maximum in the 16-17 and 20-21 months age groups. The findings of the study suggest that number of teeth can be used as a parameter for the estimation of age.     

Characterization, mapping, and distribution of the two XMRV parental proviruses

Xenotropic murine leukemia virus-related virus (XMRV) was previously reported to be associated with human prostate cancer and chronic fatigue syndrome. Our groups recently showed that XMRV was created through recombination between two endogenous murine retroviruses, PreXMRV-1 and PreXMRV-2, during the passaging of a prostate tumor xenograft in nude mice. Here, multiple approaches that led to the identification of PreXMRV-2, as well as the distribution of both parental proviruses among different mouse species, are described. The chromosomal loci of both proviruses were determined in the mouse genome, and integration site information was used to analyze the distribution of both proviruses in 48 laboratory mouse strains and 46 wild-derived strains. The strain distributions of PreXMRV-1 and PreXMRV-2 are quite different, the former being found predominantly in Asian mice and the latter in European mice, making it unlikely that the two XMRV ancestors could have recombined independently in the wild to generate an infectious virus. XMRV was not present in any of the mouse strains tested, and among the wild-derived mouse strains analyzed, not a single mouse carried both parental proviruses. Interestingly, PreXMRV-1 and PreXMRV-2 were found together in three laboratory strains, Hsd nude, NU/NU, and C57BR/cd, consistent with previous data that the recombination event that led to the generation of XMRV could have occurred only in the laboratory. The three laboratory strains carried the Xpr1(n) receptor variant nonpermissive to XMRV and xenotropic murine leukemia virus (X-MLV) infection, suggesting that the xenografted human tumor cells were required for the resulting XMRV recombinant to infect and propagate.     

Efficacy of Indolicidin,Cecropin A (1-7)-Melittin (CAMA) and Their Combination Against Biofilm-Forming Multidrug-Resistant Enteroaggregative Escherichia coli

The present study examined the anti-biofilm efficacy of two short-chain antimicrobial peptides (AMPs), namely, indolicidin and cecropin A (1-7)-melittin (CAMA) against biofilm-forming multidrug-resistant enteroaggregative Escherichia coli (MDR-EAEC) isolates. The typical EAEC isolates re-validated by PCR and confirmed using HEp-2 cell adherence assay was subjected to antibiotic susceptibility testing to confirm its MDR status. The biofilm-forming ability of MDR-EAEC isolates was assessed by Congo red binding, microtitre plate assays and hydrophobicity index; broth microdilution technique was employed to determine minimum inhibitory concentrations (MICs) and minimum biofilm eradication concentrations (MBECs). The obtained MIC and MBEC values for both AMPs were evaluated alone and in combination against MDR-EAEC biofilms using crystal violet (CV) staining and confocal microscopy-based live/dead cell quantification methods. All the three MDR-EAEC strains revealed weak to strong biofilm-forming ability and were found to be electron-donating and weakly electron-accepting (hydrophobicity index). Also, highly significant (P < 0.001) time-dependent hydrodynamic growth of the three MDR-EAEC strains was observed at 48 h of incubation in Dulbecco’s modified Eagle’s medium (DMEM) containing 0.45% D-glucose. AMPs and their combination were able to inhibit the initial biofilm formation at 24 h and 48 h as evidenced by CV staining and confocal quantification. Further, the application of AMPs (individually and combination) against the preformed MDR-EAEC biofilms resulted in highly significant eradication (P < 0.001) at 24 h post treatment. However, significant differences were not observed between AMP treatments (individually or in combination). The AMPs seem to be an effective candidates for further investigations such as safety, stability and appropriate biofilm-forming MDR-EAEC animal models.

     

Low oxygen tension potentiates proliferation and stemness but not multilineage differentiation of caprine male germline stem cells

The milieu of male germline stem cells (mGSCs) is characterized as a low-oxygen (O₂) environment, whereas, their in-vitro expansion is typically performed under normoxia (20–21% O₂). The comparative information about the effects of low and normal O₂ levels on the growth and differentiation of caprine mGSCs (cmGSCs) is lacking. Thus, we aimed to investigate the functional and multilineage differentiation characteristics of enriched cmGSCs, when grown under hypoxia and normoxia. After enrichment of cmGSCs through multiple methods (differential platting and Percoll-density gradient centrifugation), the growth characteristics of cells [population-doubling time (PDT), viability, proliferation, and senescence], and expression of key-markers of adhesion (β-integrin and E-Cadherin) and stemness (OCT-4, THY-1 and UCHL-1) were evaluated under hypoxia (5% O₂) and normoxia (21% O₂). Furthermore, the extent of multilineage differentiation (neurogenic, adipogenic, and chondrogenic differentiation) under different culture conditions was assessed. The survival, viability, and proliferation were significantly (p?<?0.05) improved, thus, yielding a significantly (p?<?0.05) higher number of viable cells with larger colonies under hypoxia. Furthermore, the expression of stemness and adhesion markers were distinctly upregulated under lowered O₂ conditions. Conversely, the differentiated regions and expression of differentiation-specific genes [C/EBPα (adipogenic), nestin and β-tubulin (neurogenic), and COL2A1 (chondrogenic)] were significantly (p?<?0.05) reduced under hypoxia. Overall, the results demonstrate that culturing cmGSCs under hypoxia augments the growth characteristics and stemness but not the multilineage differentiation of cmGSCs, as compared with normoxia. These data are important to develop robust methodologies for ex-vivo expansion and lineage-committed differentiation of cmGSCs for clinical applications.