Evaluation of GABA Production and Probiotic Activities of Enterococcus faecium BS5

Probiotics and Antimicrobial Proteins - Gamma-aminobutyric acid (GABA) is a principal inhibitory neurotransmitter in the central nervous system and is produced by irreversible decarboxylation of...     

Monolayer formation of human osteoblastic cells on vertically aligned multiwalled carbon nanotube scaffolds

Monolayer formation of SaOS‐2 (human osteoblast‐like cells) was observed on VACNT (vertically aligned multiwalled carbon nanotubes) scaffolds without purification or functionalization. The VACNT were produced by a microwave plasma chemical vapour deposition on titanium surfaces with nickel or iron as catalyst. Cell viability and morphology studies were evaluated by LDH (lactate dehydrogenase) release assay and SEM (scanning electron microscopy), respectively. The non‐toxicity and the flat spreading with monolayer formation of the SaOs‐2 on VACNT scaffolds surface indicate that they can be used for biomedical applications.     

Immunophenotyping of human HT29 colon cancer cell primary tumours and their metastases in severe combined immunodeficient mice

The immunophenotype of HT29 human colon cancer cells implanted into severe combined immunodeficient mice was assessed in primary tumours and their metastases in the lungs using an indirect immunohistochemical method. After primary tumours were surgically removed, the metastases were given time to develop, thus paralleling the clinical situation. While vimentin was negative in both primary and secondary tumours, E-cadherin was present as membrane-bound labelling in the primary tumours only. Whereas the markers p53, MIB1, PCNA and CEA were consistently positive in both primary and metastatic tumours, CD44 variant 6 and CA125 were negative in metastases but positive in the primary tumours. There was a significant increase in the percentage of cells labelled for p53 in the primary tumours compared with the metastases. For the proliferation markers, there was no significant difference in labelling between primary tumours and metastases for MIB1. Of the cytokeratins examined, CK 20 gave the strongest and most consistent reaction in both primary and secondary tumours. The results indicate that, for certain immunohistochemical markers, results are the same in both primary tumours and metastases. Hence, in these cases, antigens that are expressed on the primary tumour as well as on the metastases can serve as target molecules for immunologically based forms of treatment of metastases. This revised version was published online in November 2006 with corrections to the Cover Date.     

Allelic variants of ABC drug transporter Cdr1p in clinical isolates of Candida albicans

Candida drug resistance protein (Cdr1p) is a major drug efflux protein, which plays a key role in commonly encountered clinical azole resistance in Candida albicans. We have analyzed its sequence in several azole resistant clinical isolates to evaluate the allelic variation within CDR1 gene and to relate it to its functional activity. The sequence analysis revealed 53 single nucleotide polymorphisms (SNPs), out of which six were non-synonymous single nucleotide polymorphisms (NS-SNPs) implying a change in amino acid and were found in two or more than two allelic combinations in different sensitive or resistant isolates. We have identified three new NS-SNPs namely, E948P, T950S, and F1399Y, in isolates wherein F1399Y appeared to be unique and was present in one of the naturally occurring azole resistant isolates obtained from Indian diabetic patients. However, site-directed mutagenesis showed that the residue F1399 in between TMS 11 and TMS 12 does not affect the functionality of Cdr1p. Taken together, our SNPs analyses reveal that unlike human P-gp, the naturally acquired allelic variations are mostly present in non-conserved regions of the protein which do not allow Cdr1p to genetically evolve in a manner, that would allow a change in its functionality to affect substrate recognition, specificity, and drug efflux activity of C. albicans cells.     

Study of liquid culture system for micropropagation of the medicinal plant Solanum nigrum L. and its effect on antioxidant property

Solanum nigrum Linn., known for hepatoprotective and antioxidant properties, is extensively harvested from the wild. Supply is far short of demand, necessitating requirement of efficient in vitro propagation protocols. Nodal explants from wild S. nigrum plants were cultured in vitro in MS medium supplemented with 3.0 mg L^?1 IAA, 0.5 mg L^?1 BAP and gelled with 0.8 % agar. After 30 days, shoots buds were transferred to liquid MS medium of same composition. Subsequent subculture was carried out every 6 days. Shoot doubling time in solid and liquid media was calculated. Total phenolics, proanthocyanidin and flavonoid contents, ABTS^.+ and hydrogen peroxide radical scavenging antioxidant capacity of wild and in vitro aqueous leaf extracts were estimated and compared. In MS agar, 18 shoot buds were produced per explant after 30 days of culture, with shoot doubling time of 7.11 days. In liquid media, 21 shoots per explant were produced in 6 days, with a 5-fold higher multiplication rate and shoot doubling time of 1.37 days. Leaves were morphologically similar to those of wild plants. Total phenolics, proanthocyanidin and flavonoid contents of in vitro leaf extracts was 5–10 times higher than that of wild plants while ABTS^.+ and H₂O₂ radical scavenging activity was similar in both extracts. Liquid media is better suited for in vitro propagation of S. nigrum since enhanced multiplication rate was observed with shorter subculture intervals. Moreover, plants retained normal morphology and antioxidant property.     

Comparisons of the molecular evolutionary process at rbcL and ndhF in the grass family (Poaceae)

We examine rate heterogeneity among evolutionary lineages of the grass family at two plasmid loci, ndhF and rbcL, and we introduce a method to determine whether patterns of rate heterogeneity are correlated between loci. We show both that rates of synonymous evolution are heterogeneous among grass lineages and that are heterogeneity is correlated between loci at synonymous sites. At nonsynonymous sites, the pattern of rate heterogeneity is not correlated between loci, primarily due to an aberrant pattern of rate heterogeneity at nonsynonymous sites of rbcL. We compare patterns of synonymous rate heterogeneity to predictors based on the generation time effect and the speciation rate hypotheses. Although there is some evidence for generation time effects, neither generation time effects nor speciation rates appear to be sufficient to explain patterns of rate heterogeneity in the grass plastid sequences.      

Possibility of using a low-energy proton beam for particle-induced X-ray emission microanalysis.

The present analysis concentrates on the utilization of low-energy proton accelerators of several hundred kilovolts for particle-induced X-ray emission microanalysis. Experiments on stainless-steel and carbon matrices for thick target conditions have been carried out at several proton energies. The ionization cross sections for some elements are calculated using the ECPSSR theory. The effective cross section and minimum detection limits are calculated for the two matrices. With the availability of ultra LE-Ge detectors low-Z elemental detection is discussed.