Distribution, annual committed effective dose, and health safety assessment of 210Po in marine biota from Kalpakkam coast, Bay of Bengal.

Seafood, intertidal biota, beach sediment, and seawater from Kalpakkam coast, Bay of Bengal were analyzed for 210Po to evaluate the internal exposure and other radiological safety aspects. Kalpakkam houses various nuclear power generation facilities on its coast. The activity concentration of 210Po was more pronounced in the intertidal organisms. Pelagic planktivorous fishes have the highest activity of the non-technogenic radionuclide, followed by the detrital feeders, benthic planktivores, benthic carnivores, and pelagic carnivore fishes. The affinity of 210Po to organic detrital matter and planktonic organisms has led to a higher accumulation of radionuclide in planktivorous fishes. Activity concentration of 210Po in seafood ranged between 1.13 ± 0.3 and 96.71 ± 1.6 Bq kg-1 (Becquerel/kilogram). In seaweeds and gastropods, it ranged from 2.09 ± 0.2 to 8.21 ± 0.6 and from 9.31 ± 0.7 to 21.58 ± 1.2 Bq kg-1, respectively. The committed effective dose (CED) of 210Po in seafood varied from 31.18 to 456.68 µSv yr-1 (microSievert/year). Radiological hazard parameters, such as activity intake, CED in consumption, of the seafood from this coast are within the acceptable levels prescribed by the International Commission on Radiological Protection and US Environmental Protection Agency.

Role of structures in the masticator space in selecting patients with resectable T4b oral cancer: findings from a survival analysis.

Oral squamous cell cancers involving the masticatory space are staged as unresectable cancers and their treatment is difficult. Curative treatment with extensive surgery followed by adjuvant therapy is one of the treatment options. In this retrospective study, the survival of 123 patients (93 with T4a cancers, 30 with T4b cancers), treated during the period August 2009 to August 2015, was evaluated. The majority had bucco-alveolar cancers (62.6%), were male (61.8%), and were tobacco users (76.4%). The select group of T4b oral cancer patients were treated with surgery, which included infratemporal fossa clearance in all 30 patients, followed by adjuvant therapy. The masseter was the most commonly involved masticatory muscle, and 24 patients had fewer than three involved structures. Free margins were obtained in 90.2% of cases; 41.5% of cases were node-positive. One hundred and four patients (84.6%) completed adjuvant treatment. The median follow-up was 42 months. For node-negative patients with T4a and T4b cancers, the 5-year overall survival was 59% and 50.2%, respectively (P= 0.62), and 5-year disease-free survival was 64.6% and 53.5%, respectively (P= 0.01). In conclusion, the select group of patients with T4b oral cancers and less than three masticatory space structures involved had comparable outcomes to those with T4a cancers after treatment with surgery and adjuvant radiotherapy.

Recycling of ferromanganese gas cleaning plant (GCP) sludge by novel agglomeration.

Ferroalloy industries rely on minerals which are not available in pure form. The total value chain is very cost intensive and market driven. From mineral and environment conservation point of view every possible aspect must be explored for the economic utilisation of waste and low-grade ores. Unlike other metallurgical processes, Ferro alloys production generates a wide variety of waste rich in manganese/chrome which has a potential for recycling back. Fine size, high moisture content and presence of alkalis categorise this material into hazardous waste and economically non-viable. The challenge is to convert such anthropogenic material into a suitable feedstock for the furnace. In this article, the results of smelting trials carried out in electric arc furnace (EAF) using novel extruded briquettes (BREX) produced from the wastes of ferroalloy plant is discussed. The briquette produced by this technique exhibit high physical and metallurgical property and can replace the natural ore as a charge to some extent. Extruded briquettes (BREX) can be efficiently used as one of the essential charge component (up to 30% of the ore part of the charge) for the Silicomanganese smelting thus improving technical and economical parameters of the furnace and decreasing the self-cost of the Silicomanganese production.

Gentiana lutea exerts anti-atherosclerotic effects by preventing endothelial inflammation and smooth muscle cell migration.

BACKGROUND AND AIMS: Studies suggest that Gentiana lutea (GL), and its component isovitexin, may exhibit anti-atherosclerotic properties. In this study we sought to investigate the protective mechanism of GL aqueous root extract and isovitexin on endothelial inflammation, smooth muscle cell migation, and on the onset and progression of atherosclerosis in streptozotocin (STZ)-induced diabetic rats. METHODS AND RESULTS: Our results show that both GL extract and isovitexin, block leukocyte adhesion and generation of reactive oxygen species in human umbilical vein endothelial cells (HUVECs) and rat aortic smooth muscle cells (RASMCs), following TNF-alpha and platelet derived growth factor-BB (PDGF-BB) challenges respectively. Both the extract and isovitexin blocked TNF-α induced expression of ICAM-1 and VCAM-1 in HUVECs. PDGF-BB induced migration of RASMCs and phospholipase C-γ activation, were also abrogated by GL extract and isovitexin. Fura-2 based ratiometric measurements demonstrated that, both the extact, and isovitexin, inhibit PDGF-BB mediated intracellular calcium rise in RASMCs. Supplementation of regular diet with 2% GL root powder for STZ rats, reduced total cholesterol in blood. Oil Red O staining demonstrated decreased lipid accumulation in aortic wall of diabetic animals upon treatment with GL. Medial thickness and deposition of collagen in the aortic segment of diabetic rats were also reduced upon supplementation. Immunohistochemistry demonstrated reduced expression of vascular cell adhesion molecule-1 (VCAM-1), inducible nitric oxide synthase (iNOS), and vascular endothelial cadherin (VE-cadherin) in aortic segments of diabetic rats following GL treatment. CONCLUSIONS: Thus, our results support that GL root extract/powder and isovitexin exhibit anti-atherosclerotic activities.

Nutrient dynamics and seasonal variation of phytoplankton assemblages in the coastal waters of southwest Bay of Bengal.

In order to understand the phytoplankton community structure and its relationship with the environmental variables in the near shore waters of Kalpakkam, east coast of India, observations were carried out during 2008-2009. Phytoplankton population was comprised of 219 species, and the density was higher during the southwest monsoon (SWM) and inter-monsoon seasons than that of north east monsoon (NEM) season. The nutrient status on a temporal and spatial scale indicated the impact of point sources carrying anthropogenic runoff. Comparison of ambient nutrient ratios with the Redfield ratio (N/P/Si = 16:1:16) showed a clear temporal variation in the factors that regulate the phytoplankton growth. SWM and inter-monsoon season was evident to have an acute N-limitation of algal growth (~76%) whereas P-limitation was encountered during the NEM season (~75%). Interestingly, a sizable population of cyanobacteria (Trichodesmium erythraeum) were noticed during NEM season when there was an exponential increase in nitrogen concentration, probably due to nitrogen fixation. No significant impact of temperature on phytoplankton proliferation was observed in situ during the study period.

Narrow band UV emission from direct bandgap Si nanoclusters embedded in bulk Si.

We report on the formation of UV emitting Si nanoclusters (NCs) in Si, using a two stage Au implantation technique. These Si NCs, with an average size of 2 nm, show photoluminescence at room temperature, over a narrow band of about 100 meV with a peak of emission near 3.3 eV. With emission lifetimes in the range of 1.5-2.5 ns, the transitions seem to come from excitonic recombinations across a quasi-direct gap. Since the structures are below the surface, there is no adverse effect of oxidation resulting in a shift in emission wavelength. On the other hand, an annealing at 500 °C has been found to result in a significant increase in the emission intensity. This is due to localized plasmon induced electric field enhancement in Au nano-islands in the vicinity.

Observation of a universal aggregation mechanism and a possible phase transition in Au sputtered by swift heavy ions.

Two exponents delta for the size distribution of n-atom clusters, Y(n) approximately n{-delta}, have been found in Au clusters sputtered from embedded Au nanoparticles under swift heavy ion irradiation. For small clusters, below 12.5 nm in size, delta has been found to be 3/2, which can be rationalized as occurring from a steady state aggregation process with size independent aggregation. For larger clusters, a delta value of 7/2 is suggested, which might come from a dynamical transition to another steady state where aggregation and evaporation rates are size dependent. In the present case, the observed decay exponents do not support any possibility of a thermodynamic liquid-gas-type phase transition taking place, resulting in cluster formation.

MeV Au irradiation induced nanoparticle formation and recrystallization in a low energy Au implanted Si layer.

Au implantation at 32 keV into Si(100), in a fluence range of 1 x 10(15)-1 x 10(17) cm(-2), has been used to produce a gold-rich damaged Si layer of thickness around 30 nm. Local recrystallization of this layer, induced by 1.5 MeV Au irradiation, to a fluence of 1 x 10(15) cm(-2), has been studied using Raman scattering, photoluminescence (PL) and x-ray photoemission spectroscopy (XPS). For a sample with a low energy Au fluence of 5 x 10(15) cm(-2), the MeV Au irradiation has been found to result in Si nanocrystal (NC) formation. The size of the NCs, as estimated from the PL data, has been found to be about 4 nm, which agrees well with the result of a thermal spike model calculation. Annealing of the sample at 500 degrees C resulted in an enhanced PL signal, without any significant shift in peak position, indicating an increase in the local concentration of the NCs. In the case of samples with an initial Au fluence above 1 x 10(16) cm(-2), the MeV Au irradiation has been found to result in better overall recrystallization of the amorphous layer, with silicide formation as observed by XPS. However, there was no PL signal, indicating the absence of Si NCs in the system. The results suggest that the initial amorphizing Au fluence plays a crucial role in Si NC formation induced by MeV ion irradiation.

Transient or occult HIV infections may occur more frequently than progressive infections: changing the paradigm about HIV persistence.

Evidence of transient HIV infections was found in 8 subjects at high-risk for HIV infection among 47 longitudinally studied over 2-5 (average approximately 3.5) years, whereas only two subjects developed progressive infection. All of these subjects developed serum antibodies (Ab) to conformational epitopes of HIV gp41 (termed "early HIV Ab"), but the 8 transiently infected subjects lost this Ab within 4-18 months, and did not seroconvert to positivity in denatured antigen EIA or Western Blot (WB). However, the two progressively infected subjects eventually seroconverted in the EIA and WB tests within one to two months after the appearance of "early HIV Ab". HIV env and nef sequences were directly PCR amplified from the peripheral blood mononuclear cells (PBMCs) of two of the eight transiently infected subjects during the time of "early HIV Ab"-postivity, and these showed significant sequence divergence from the HIV strains in the laboratory, indicating that they were not laboratory contaminants. Genome identity typing ("paternity-typing") of PBMC samples obtained at the time of "early HIV Ab"-positivity, and later when Ab was absent from each of the 8 subjects, showed that blood samples were not mixed-up. This provides further evidence that transient or occult infection with HIV does occur, and perhaps at a greater frequency than do progressive infections.

Evaluation of phytotoxicity and genotoxicity of uranyl nitrate in Allium assay system.

Uranyl nitrate inhibited root growth of Allium cepa at > or = 25 microM concentration. Fluorimetric analysis of metal uptake indicated the entry and accumulation of uranium into the root cell. Uranyl nitrate was neither clastogenic nor aneugenic as it failed to induce micronuclei significantly, but between 25 and 100 microM concentration, it increased significantly the frequency of sister chromatid exchange over that of control, implying its genotoxicity that possibly interfered with DNA replication and/or repair process.

Low-level secretion of human hepatitis B virus virions caused by two independent, naturally occurring mutations (P5T and L60V) in the capsid protein.

The functional significance of naturally occurring variants of human hepatitis B virus (HBV) remains largely unknown. Previously, we reported an immature secretion phenotype caused by a highly frequent mutation at amino acid 97 of the HBV core (capsid) protein (HBcAg). This phenotype is characterized by a nonselective and excessive secretion of virions containing an immature genome of single-stranded viral DNA. To extend our study of virion secretion to other naturally occurring variants, we have characterized mutations at HBcAg codons 5, 38, and 60 via site-directed mutagenesis. Although the phenotype of the mutation at codon 38 is nearly identical to that for the wild-type virus, our study reveals that a single mutation at codon 5 or 60 exhibits a new extracellular phenotype with significantly reduced virion secretion yet maintains normal intracellular viral DNA replication. A complementation study indicates that the mutant core protein alone is sufficient for the "low-secretion" phenotype. Furthermore, the low-secretion phenotype of the codon 5 mutant appears to be induced by the loss of a parental proline residue, rather than by the gain of a new amino acid. Our study underscores the core protein as another crucial determinant in virion secretion, in addition to the known envelope proteins. Our present results suggest that a very precise structure of both alpha-helical and nonhelical loop regions of the entire HBcAg molecule is important for virion secretion. The low-secretion variants may contribute to the phenomenon of gradually decreasing viremia in chronic carriers during the late phase of persistent infection.

The mechanism of an immature secretion phenotype of a highly frequent naturally occurring missense mutation at codon 97 of human hepatitis B virus core antigen.

A very frequent missense mutation at codon 97 of human hepatitis B virus (HBV) core antigen (HBcAg) has been found in chronic carriers worldwide. Functional characterization of this mutant revealed one intracellular and two extracellular phenotypes in contrast to wild-type HBV: (i) a 6- to 12-fold decrease in the level of the full-length relaxed circular DNA, a 4- to 5-fold decrease in the plus-strand DNA, and an approximately 1.8-fold decrease in the minus-strand and overall DNA levels in the intracellular viral core particles; (ii) a 5.7-fold increase in the immature secretion of Dane particles, containing minus-strand, single-stranded virion DNA; and (iii) a significant reduction of nonenveloped core particles in the medium. The steady-state levels of mutant and wild-type core proteins expressed from the same vector appeared to be similar. Using a complementation assay and gradient centrifugation analysis, we demonstrated that this mutant core protein alone is necessary and sufficient for immature secretion. The decreased level of intracellular HBV DNA is caused by both the cis defect of the mutant genome and the trans defect of the mutant core protein. We have dissected further the relationship between the intracellular and extracellular phenotypes of mutant F97L. The pleiotropic effects of the HBcAg codon 97 mutation were observed consistently in several different experimental settings. The mechanism and biological significance of these findings are discussed.

Hypohaptoglobinaemia as a biochemical and epidemiological marker of falciparum malaria.

OBJECTIVES: The study was conducted in two parts to find out the usefulness of hypohaptoglobinemia (Hpo) as a biochemical and epidemiological marker of malaria. Part-I study was conducted in a Medical College Hospital to find out Hpo in malaria and the time required for normalization of Hpo. Part-II study was undertaken in two endemic areas of malaria to find out the prevalence of Hpo and haptoglobin index (HI) throughout the year along with other indicators of malaria. METHODS: In Part-I study, 172 patients of malaria constituting 58, 52 and 62 patients of cerebral malaria, uncomplicated falciparum malaria and vivax malaria, respectively were enrolled. Along with routine haematological and biochemical investigations, haptoglobin (Hp) estimation was done by endoplate haptoglobin test kit on admission and at 15 days interval for 3 months. In Part-II study Hp was estimated is 305 subjects in two endemic areas of malaria. HI, parasitic index, slide positivity rate (SPR), slide falciparum rate (SFR) were estimated throughout the year and HI was compared with these epidemiological markers. RESULTS: Hpo was present in 102 (92.7%) cases of falciparum malaria which was significantly more than vivax malaria and non-malarial fever. The normalisation of Hpo took about a month or more. The incidence of Hpo was 32.1% is endemic and 4.7% in nonendemic area of malaria. The HI varied between 12.4 to 25.2% throughout the year and was found to be a better marker than other classical markers of malaria. CONCLUSION: Hypohaptoglobinemia may be considered as a useful indirect indicator of falciparum malaria. HI can be used as an epidemiological maker which is better than classical markers of malaria used at present.

The rpoH gene encoding sigma 32 homolog of Vibrio cholerae.

The Vibrio cholerae rpoH gene coding for the heat-shock sigma factor, sigma 32, has been cloned and shown to functionally complement Escherichia coli rpoH mutants. The nt sequence of the gene has been determined and the deduced aa sequence is more than 80% homologous to the E. coli rpoH gene product. Downstream of the V. cholerae rpoH gene, an unidentified dehydrogenase gene (udhA) is present on the opposite strand facing rpoH. The predicted secondary structure of the 5'-proximal region of V. cholerae rpoH mRNA is apparently different from the conserved secondary structures of the rpoH mRNA reported for several bacterial species. The 'RpoH box', a stretch of 9 aa (QRKLFFNLR) unique to sigma 32 factors, and the 'downstream box' sequence complementary to a part of the 16S rRNA, have been detected.

Genotoxicity testing of two red dyes in the somatic and germ line cells of Drosophila.

Two red dyes, rhodamine B and amaranth, were tested for their genotoxic effects in the somatic (wing primordia) and germ line cells of Drosophila melanogaster following the wing spot and the sex-linked recessive lethal tests. Second- and third-instar larvae, carrying suitable genetic markers, were subjected to chronic exposure to different concentrations of the test dyes. The results indicate that rhodamine is genotoxic in both somatic and germ line cells and amaranth is non-genotoxic.

An analytical presentation of drug resistance in Plasmodium falciparum and guidelines to formulate a drug strategy.

The present paper describes the advantage/limitation of presently available 'in-vivo' methods to detect sensitivity status of Plasmodium falciparum to commonly used antimalarial drugs. The paper is based on a retrospective analysis of 890 P. falciparum cases and various parameters used to define the level of drug resistance. The presented quantification methodology with weightage system to different epidemiological variables of resistance may provide a guideline as to the level of parasite resistance, and a switch over to another antimalarial of firstline treatment which is of the considerable importance to provide early diagnosis and prompt treatment to avert the severe cases/deaths due to malaria.

Heat shock response and heat shock protein antigens of Vibrio cholerae.

Sixteen heat shock proteins (Hsps) have been identified in the hypertoxinogenic strain 569B of Vibrio cholerae which are synthesized in response to small and large elevations of temperature. The induction of the Hsps is necessary for the cells to survive the deleterious effects of heat. There is no difference in the pattern of induction of the Hsps in V. cholerae strains varying in levels of toxinogenicity. One of the major low-molecular-mass Hsps, a 16-kDa protein, is preferentially degraded following shift down of temperature. This protein is induced at a much lower level at high temperatures in cells maintained in the laboratory for a prolonged period. The only Hsp located in the outer membrane of V. cholerae cells is a 23-kDa protein. Western immunoblot analysis with human immune sera collected from convalescent cholera patients revealed that this protein is markedly immunogenic. The human immune serum also reacted with the 69- and 16-kDa major Hsps and the 88-, 66-, and 46-kDa Hsps but not with the 61-kDa major Hsp identified as the groEL gene product. All major Hsps reacted with rabbit anti-V. cholerae sera. Ethanol stress leads to the induction of four of the major Hsps and three additional proteins.

Plasmodium falciparum sensitivity in "in-vivo" and its distribution in geo-ecological zones of Gujarat.

Plasmodium falciparum sensitivity test in "in-vivo" carried out in 450 patients revealed, parasite clearance in 66.45 percent cases with 25 mgm/kg body wt of chloroquine. Mean parasite clearance time (MPCT) of sensitive and R I, resistant cases reached near parallelism with an early recrudescence in RI cases indicating stabilisation of genetic change in the parasite strain. The analysis of data revealed that proportionately higher resistance was recorded in coastal area having deciduous (wet) forest ecotype followed by plains of deciduous dry forest and semi arid/arid ecotypes.