Levels of heavy metals in tissues of shingi fish (Heteropneustes fossilis) from Buriganga River, Bangladesh.

Heavy metal pollution was reported in commercially valuable freshwater edible fish in the Buriganga River, Bangladesh. The concentrations of As, Pb, Cd, Cr, Zn, and Cu were investigated in the muscle, gill, stomach, intestine, and liver of Heteropneustes fossilis caught at three stations to assess the degree of fish pollution by heavy metals. Significant differences in concentrations of analyzed elements were observed among different tissues, but not among the stations. The ranges of the measured concentrations (µg/g dry weight) in the tissues of H. fossilis were as follows: arsenic concentration was (0.2-0.4), (0.82-0.90), (3.29-3.99), (2.20-2.80), and (2.41-2.90), that of lead was (1.79-2.20), (4.95-6.55), (10.36-13.38), (5.74-9.70), and (18.20-18.79), that of cadmium was (0.3-0.4), (2.87-4.27), (1.03-1.63), (1.55-4.59), and (2.25-5.50), that of chromium was (1.40-1.70), (3.52-3.72), (2.28-5.29), (2.77-3.79), and (4.25-8.65), that of zinc was (24.47-28.82), (16.82-18.80), (20.22-22.20), (22.86-26.68), and (60.82-67.80), and that of copper was (7.80-8.50), (6.22-6.81), (38.21-44.25), (17.07-21.03), and (43.24-47.30) in the muscle, gill, stomach, intestine, and liver, respectively. This research showed that the liver appeared to be the main heavy metal storage tissue, while the muscle had the lowest levels of analyzed metals. The concentrations of metal in the muscles not exceeded the acceptable levels for a food source for human consumption.

Internal transcribed spacer region 1 as a promising target for detection of intra-specific polymorphisms for Strongyloides stercoralis.

Background: Strongyloides stercoralis, the causative agent of strongyloidiasis, is a parasitic worm that has larvae capable of reinfecting the same host. This nematode infection is therefore difficult to treat and to achieve total cure. Information about genetic variation and differences in drug susceptibility between strains is needed to improve treatment outcomes. Aim: To develop a polymerase chain reaction (PCR) to identify the intra-species variation among 13 S. stercoralis isolates collected from Bangladesh, USA and Australia. Material & Methods: PCR assays were designed by using primers targeting S. stercoralis internal transcribed spacer (ITS) regions 1 and 2. Sequence data generated by these PCR products were compared to the existing ITS1/2, 18S and 28S rRNA gene sequences in GenBank for phylogenetic analysis. Results: Intra-species single nucleotide polymorphisms (SNPs) were identified in ITS1 and in the 5.8S rRNA gene. The generated phylogram grouped the 13 isolates into dog, Orangutan and human clusters. Conclusion: This method could be used as an epidemiological tool to study strain differences in larger collections of S. stercoralis isolates. The study forms the basis for further development of an ITS-based assay for S. stercoralis molecular epidemiological studies.

Measurements of radioactivity in books and calculations of resultant eye doses to readers.

Natural and fallout radioactivity in some book samples were measured with an HPGe detector coupled with a 4096 channel analyzer in order to estimate the radiation doses to readers' eyes from books. The radiation doses to a population at large due to the presence of radioactivity in the book are not significant. Thus, no radiation hazard occurs from the radioactivity content in the book. The estimated radiation doses to eyes were found to be below the maximum permissible dose to eyes recommended by ICRP.

Preconcentration of trace silver with yeast for river water analysis.

A new preconcentration method with yeast is presented. The method was evaluated for the determination of trace silver in river waters by graphite furnace atomic absorption spectrometry (GFAAS). A suitable cultivation bed for preconcentration of silver was 1.75 mg ml-1 2-ammonium hydrogen phosphate. The optimal cultivation time and temperature were 2 h and 25 degrees C. Under optimal conditions, silver in aqueous sample was concentrated to 6.9-fold by yeast. The detection limit was 4.6 pg ml-1 (3S/N) for silver in river water. The yeast preconcentration method was applied to the determination of silver in river waters. The recovery of spiked silver was in the range of 89 to 110%. By the preconcentration, it was found that ultra trace silver in river waters could be determined without interferences of matrix elements, after only the cultivation and with no chemical treatment.

Occurrence of urinary tract infection in adolescent and adult women of shanty town in Dhaka City, Bangladesh.

BACKGROUND: Urinary tract infection (UTI) is commonly experienced by women of various age groups especially elderly ones. We planned to find out the prevalent microbial strains causing UTI in slum inhabitant adolescent and adult women in Dhaka City, Bangladesh. METHODS AND MATERIALS: Urine sample was collected from 462 UTI suspected female subjects. Pathogenic bacteria were identified using standard microbiological tests, and antimicrobial sensitivity profiles of the pathogens were determined. RESULTS: Bacteriuria was present in 9% of the subjects. A higher incidence (16.8%) of UTI was noted among adult women aged above 19 years. Escherichia coli (69%), Streptococcus spp. (15%) and Pseudomonas aeruginosa (7%) were more frequently isolated from the urine samples compared to Enterococcus faecalis (3%), Staphylococcus aureus (2%), Klebsiella pneumoniae (2%) and Hafnia alvei (2%). The E. coli isolates showed complete resistance to commonly used drugs, and 58% of these isolates were multidrug resistant (MDR). Minimum Inhibitory Concentration (MIC) values for ciprofloxacin ranged between 64µg/ml and 512µg/ml, and the Minimum Bactericidal Concentration (MBC) values against the isolates were 128µg/ml or above. Isolated strains of E. coli exhibited equal extent of ciprofloxacin resistance irrespective of the presence or absence of plasmid in them. CONCLUSION: The extent of drug resistance among the uropathogens if ignored may render them uncontrollable. This study suggests regular monitoring of drug resistance phenotype of the UTI pathogens to reduce the morbidity of female UTI patients and offer better treatment strategy in the healthcare sectors of Bangladesh.

Radioactivity level in soil of a palaeo beach in the south-eastern part of Bangladesh and evaluation of radiation hazard.

A small part of the palaeo beach formation extending along the south-eastern fringe of Bangladesh was selected as study area. The sandy beach formation, enriched with heavy mineral sands containing ²³²Th-bearing monazite, is covered by a thin layer of top soil. Activity concentrations of natural and artificial radionuclides (²³8U, ²²6Ra, ²³²Th, 4°K and ¹³7Cs), outdoor and indoor annual effective dose rates and the radiation hazard indices were determined in the soil. The radionuclides, investigated by direct gamma-ray spectrometry using HPGe detector, showed that mean activity concentrations of ²²6Ra, ²³8U, ²³²Th, 4°K and ¹³7Cs in soils were 254.53 ± 6.66, 193.95 ± 7.23, 362.18 ± 6.45, 135.79 ± 24.63 and 2.21 ± 0.49 Bq kg⁻¹ respectively. The mean value of radium equivalent activity, external and internal hazards, outdoor absorbed dose rate and total annual effective dose rate were 783.24 Bq Kg⁻¹, 2.12 and 2.80, 354.32 nGyh⁻¹ and 2.52 mSv y⁻¹, respectively, which exceed the average worldwide limit and may pose a radiological threat to inhabitants.