Concentration of toxic metals and potential risk assessment in edible fishes from Congo River in urbanized area of Kinshasa,DR Congo

Abstract

The objective of this research is to determine the concentration and potential health risks of toxic metals in six most consumed freshwater fish species (Auchenoglanis occidentalis, Bagrus ubangensis, Citharinus gibbosus, Distichondus fasciolatus, Marcusenius moorii, and Schilbe mystus). A total of 126 samples of these fish species were collected from seven sites of Congo River in the vicinity of Kinshasa City, Democratic Republic of the Congo. Toxic metals (Cr, Co, Ni, Zn, Se, Ag, Cd, Sn, Sb, and Pb) levels in fish muscle tissues were determined using Inductively Coupled Plasma Mass Spectrometry whereas Hg analysis was carried out using atomic absorption spectrophotometry. The maximum metal concentration (mg kg^?1 wet weight) of Zn (59.72), Sb (5.98), and Pb (4.96) was detected in muscle tissues of M. moorii, C. gibbosus, and D. fasciolatus, respectively. Pb, Zn, and Hg values in many fish samples exceeded the permissible levels set by Food and Agriculture Organization and World Health Organization for human consumption. Given the concentrations of Pb in all fish species and Zn in M. moorii, human health implications are likely to occur on continuous consumption. Addition, the evaluation of potential health risks for fish consumers indicates that there may or not be adverse effects.     

A database for the predicted pharmacophoric features of medicinal compounds

Pharmacophore feature is defined by a set of chemical structure patterns having the active site of drug like molecule. Pharmacophore can be used to assist in building hypothesis about desirable chemical properties in drug molecule and hence it can be used to refine and modify drug candidates. We predicted the pharmacophoric features of 150 medicinal compounds from plants for anti-cancer, anti-carcinogenic, anti-diabetic, anti-microbial, and anti-oxidant. Estimation of pharmacophoric feature is necessary to ensure the optimal supramolecular interaction with a biological target and to trigger or block its biological response. We subsequently make this data available to open access using a database at the URL: http://www.hccbif.info/index.htm AVAILABILITY: The database is available for free at http://www.hccbif.info/index.htm.     

Comprehensive DNA copy number profile and BAC library construction of an Indian individual

Bacterial artificial chromosomes (BACs) are used in genomic variation studies due to their capacity to carry a large insert, their high clonal stability, low rate of chimerism and ease of manipulation. In the present study, an attempt was made to create the first genomic BAC library of an anonymous Indian male (IMBL4) consisting of 100,224 clones covering the human genome more than three times. Restriction mapping of 255 BAC clones by pulse field gel electrophoresis confirmed an average insert size of 120 kb. The library was screened by PCR using SHANK3 (SH3 and multiple ankyrin repeat domains 3) and OLFM3 (olfactomedin 3) specific primers. A selection of clones was analyzed by fluorescent in situ hybridization (FISH) and sequencing. Fine mapping of copy number variable regions by array based comparative genomic hybridization identified 467 CNVRs in the IMBL4 genome. The IMBL4 BAC library represents the first cataloged Indian genome resource for applications in basic and clinical research.     

Mitochondrial dysfunction and genetic heterogeneity in chronic periodontitis

We performed an extensive study on mitochondrial dysfunction in chronic periodontitis (CP). Electron microscopic analysis of gingival cells revealed abnormal mitochondria in 60% of the patients. Mitochondrial membrane potential and oxygen consumption of gingival cells were reduced by 4 fold and 5.8 fold, respectively; whereas ROS production was increased by 18%. The genetic analysis by complete mitochondrial DNA sequencing revealed the identification of 14 novel mutations only in periodontal tissues but not in the blood, suggesting a role of oxidative stress on periodontal tissues. Thus, our functional and genetic analysis provided an evidence for the mitochondrial dysfunction in CP.     

Zona-float method for separating mouse eggs from other cells.

We have developed a new method for separating mouse eggs from other cells, such as cumulus cells, using centrifugation with Percoll. Solutions of 45, 22.5, 11.3, and 5.6% Percoll were tested. With the 22.5% solution, 99% of whole eggs obtained by in vitro fertilization were collected from the upper part of the Percoll solution, and 98% of 2-cell embryos collected from these eggs developed to the blastocyst stage. Offspring were obtained after transfer of collected embryos to female mice. The greatest advantage of this method is that undamaged eggs are separated from other cells in one simple operation, regardless of the number of eggs.     

Molecular docking analysis of tetracyclic triterpenoids from Cassia fistula L. with targets for diabetes mellitus

It is of interest to develop effective drugs for diabetes mellitus. We document the molecular docking analysis data of tetra-cyclic-tri-terpenoids from Cassia fistula L. with targets for diabetes mellitus.     

Displaceable binding of [3H]l-glutamic acid to non-receptor materials

[3H]L-glutamic acid binding to microfuge tubes and glass was investigated in four buffers. Background binding to these materials was negligible, but was increased by centrifugation or suction in Tris-HCl and Tris-citrate buffer. This binding was much less or eliminated when HEPES-KOH, or Tris-acetate buffer was used instead. [3H]L-glutamate binding to microfuge tubes was inhibited by L- but not D-isomers of glutamate and aspartate. DL-2-amino-7-phosphonoheptanoic acid also did not inhibit the binding. Other compounds which showed low to moderate inhibition were: N-methyl-D-aspartate, quisqualate, L-glutamic acid diethyl ester, N-methyl-L-aspartate, kainate, and 2-amino-4-phosphonobutyrate. Binding was inhibited by denatured rat brain membranes. A protein-dependent [3H]glutamate binding was obtained with a repeatedly frozen-thawed membrane preparation when binding was done in Tris-acetate buffer. It is recommended that Tris-acetate or HEPES-KOH buffer should be used in the glutamate binding assay. If Tris-HCl or Tris-citrate buffer is used, appropriate control experiment should be done to correct for binding to microfuge tubes or glass fiber filters.     

Optimization of nutrients for the production of RNase by <Emphasis Type="Italic">Bacillus firmus</Emphasis> VKPACU1 using response surface methodology

Medium optimization for the nuclease (RNase) production by Bacillus firmus VKPACU-1 was studied using the one-factor-at-a-time method and Response Surface Methodology (RSM). One-factor-at-a-time methodology was used to study the effects of carbon, nitrogen, phosphorus sources, and physical conditions such as pH and temperature, on nuclease (RNase) production. After optimizing the carbon (glucose) and nitrogen (tryptone) sources in the culture medium the physical conditions, pH (6.5) and temperature (35°C) were also optimized. Later these conditions were chosen as the main factors and used in the experimental design. The central composite design (CCD) of the RSM was employed to evaluate the interactive effects of these four variables. The optimized values obtained by the statistical analysis showed that glucose 5.95 g/L, tryptone 22.5 g/L, pH 6.5, and temperature 35°C affected maximum nuclease (RNase) production. When utilizing these proposed optimized conditions, the model predicted nuclease (RNase) production of 43.6 U/mL and in the validation experiments, the nuclease production obtained was 46.5 U/mL. The nuclease production in medium optimized by RSM was 26% higher, than in the non-optimized medium.