Prevalence and Drivers of Self-Medication Practices among Savar Residents in Bangladesh: A Cross-Sectional Study.

BACKGROUND: Self-medication practice (SMP) is widely adopted among residents of such countries as Bangladesh. However, the major determinants of SMP have only scarcely been evaluated. Therefore, this cross-sectional study aimed to fill this knowledge gap by assessing the prevalence and determining factors of SMP. METHODS: A convenience sample of individuals residing in Savar (Dhaka, Bangladesh) >16 years of age and suffering from an illness >2 months underwent face-to-face interviews during January-February, 2019. RESULTS: Among 520 interviewees fulfilling entry criteria, the prevalence of SMP was reported as 60.2%. Drug shops, previous knowledge or prescription, and consulting with peers (friends or relatives) were the most sought sources of SMP, whereas simple illness, higher consulting fees, unsatisfactory health-care services, and delayed access were reported as the motives. From the regression analysis, the sociodemographic risk factors of SMP were reported as being older (compared to <18 years), married, illiterate (compared to having higher education), having engaged in any occupation (ie, service, business, homemaker, and others compared to student), and suffering from chronic illness. CONCLUSION: SMP is highly prevalent and exhibits significant socioeconomic determinants. Development of proper health care-access systems and public education should be implemented to reduce the rate of SMP.

Contamination and ecological risk assessment of trace elements in sediments of the rivers of Sundarban mangrove forest, Bangladesh.

In this study, total concentrations of 16 trace elements (Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, Sb, Hg, Pb, Th and U) in sediments of the rivers of the Sundarban mangrove forest, after the catastrophic oil spill accident in the Sela river of Sundarban, were determined. The overall mean concentrations of V, Cr, Fe and Cd in surface sediments of the Sundarban are remarkably higher than available literature data of those elements. Trace element contamination assessment, using different environmental contamination indices, reveals that As, Sb, Th and U are low to moderately contaminated while Cd is moderately to severely contaminated in the sediments of this area. The multivariate statistical analyses were applied to reveal the origin and behavior of the elements during their transport in the mangrove ecosystem. High Cr, Ni, Cu and As concentrations suggest the risk of potentially adverse biological effects in the ecosystem.

Association between serum vitamin D, retinol and zinc status, and acute respiratory infections in underweight and normal-weight children aged 6-24 months living in an urban slum in Bangladesh.

We conducted a longitudinal assessment in 466 underweight and 446 normal-weight children aged 6-24 months living in the urban slum of Dhaka, Bangladesh to determine the association between vitamin D and other micronutrient status with upper respiratory tract infection (URI) and acute lower respiratory infection (ALRI). Incidence rate ratios of URI and ALRI were estimated using multivariable generalized estimating equations. Our results indicate that underweight children with insufficient and deficient vitamin D status were associated with 20% and 23-25% reduced risk of URI, respectively, compared to children with sufficient status. Underweight children, those with serum retinol deficiency were at 1·8 [95% confidence interval (CI) 1·4-2·4] times higher risk of ALRI than those with retinol sufficiency. In normal-weight children there were no significant differences between different vitamin D status and the incidence of URI and ALRI. However, normal-weight children with zinc insufficiency and those that were serum retinol deficient had 1·2 (95% CI 1·0-1·5) times higher risk of URI and 1·9 (95% CI 1·4-2·6) times higher risk of ALRI, respectively. Thus, our results should encourage efforts to increase the intake of retinol-enriched food or supplementation in this population. However, the mechanisms through which vitamin D exerts beneficial effects on the incidence of childhood respiratory tract infection still needs further research.

Malignancy in Solitary Thyroid Nodule.

This prospective study was done to find out the relative frequency of the malignancy in cold solitary thyroid nodules with other solitary thyroid nodules (hot and warm). This study was carried out in the Department of General Surgery and Otolaryngology-Head & Neck Surgery, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from January 2011 to February 2012. One hundred (100) patients with clinically and ultrasonographically diagnosed as solitary thyroid nodules were included. Out of them, 52% of patients were in the third and fourth decades of life and 26% were in the second decade of life. In sex distribution, females were more affected than males and female: male ratio was 2.1:1. All patients presented with neck swelling, which moved with deglutition and 18% presented with palpitation. Solitary nodule was present in about 60% in the right lobe and 32% in the left lobe. In 72% patients, radioiodine uptake was low; in 25% patient's radioiodine uptake was normal. The thyroid scan revealed 72% cold nodule, in 25% patients radioiodine uptake was normal. On Ultrasonographic study, 60% were solid, 28% cystic and others mixed. Each and every patient of this series was treated surgically. Mostly (73%) lobectomy was done. Total thyroidectomy was done in 16% cases. On histopathology, 56% were colloid nodule, 28% were adenoma and 16% were carcinoma. Among the 16% malignant patients, majority of the patients had their age between 21-48 years. Histopathological types were mostly papillary (50%). Complications of surgery were mostly hoarseness of voice (5%), hematoma (4%), infection (2%) and hypoparathyroidism (3%). In this study, more malignant cases (20.83%) were found in cold solitary nodules.

T-RFLP reveals high ß-Proteobacteria diversity in microbial fuel cells enriched with domestic wastewater.

AIMS: To assess the biodiversity of a large number of microbial fuel cell (MFC) anodes from a variety of MFC designs, all enriched with domestic wastewater, using a molecular fingerprinting method. METHODS AND RESULTS: We optimized a protocol allowing the rapid characterization of MFC communities using terminal restriction fragment length polymorphism (T-RFLP) with two different sets of primers and a varying number of restriction enzymes. This protocol was further validated by direct comparison with bacterial clone libraries. Twenty-one MFC anodes were analysed by T-RFLP. We also provided a statistical comparison with other bacterial communities from environments sharing common features. CONCLUSIONS: Bacterial communities were dominated by ß-Proteobacteria, mostly belonging to the Burkholderiales order, that are known to play an active role in the cycle of metals such as iron and manganese. This property may allow them to properly pass electrons to the anode of an MFC. SIGNIFICANCE AND IMPACT OF THE STUDY: Unlike other groups, ß-Proteobacteria have seldom been acknowledged as potentially efficient electrochemically active bacteria (EAB) in MFCs. Yet, they are plentiful in natural environments like biocorrosion biofilms and acid mine drainages that consequently show some potential for MFC enrichment.

A microbial fuel cell equipped with a biocathode for organic removal and denitrification.

Microbial fuel cells (MFCs) are a promising anaerobic technology but they are limited by the high cost of the catalyst used at the cathode (typically platinum). In this study, we designed a novel type of two-chambered MFC wherein an autoheterotrophic denitrifying biofilm replaced the costly catalyst on the cathode surface. Micro-organisms performed denitrification by using electrons supplied by bacteria oxidizing domestic wastewater and acetate as substrates in the anode chamber. This two-chambered MFC equipped with a biocathode generated during more than 1.5 month up to 9.4 mW m(-2) of anode surface or 0.19 W m(-3) of anode chamber volume, while removing over 65% of COD, 84% of total nitrogen and nearly 30% of suspended solids with domestic wastewater as a substrate, and nearly 95% of acetate in the subsequent experiments.

An insight into cathode options for microbial fuel cells.

Microbial fuel cell (MFC) is an emerging and promising technology, particularly in the field of wastewater treatment. The MFC capability of achieving organic removal and generating in situ electricity could make it an attractive alternative wastewater treatment technology over conventional treatment technologies. However, MFC is still far from being economically viable, especially because of the cost of the platinum (Pt) catalyst that makes possible the reaction at the cathode. In this study, we tested alternative cathode catalysts, namely sputter-deposited Cobalt (Co) and denitrifying bacteria (biocathode). The performance of these innovative cathodes was compared with that of classic Pt-cathodes. Co competed well with Pt, but further research is still required for biocathodes. However, biocathodes MFC have showed promise.

Improving locality in binary representation via redundancy.

Binary representation suffers from the problem of positional dependence, where the amplitude of phenotype variation is dependent on the position of the altered genotype bits. However, this is contrary to conventional variation operations that treat each genotype bit equally. Positional dependence can be attributed to the poor locality, which results in neighboring genotypes having low correlation in the phenotype space, reducing the effectiveness of systematic local search and evolutionary search based on small mutation steps. For this purpose, this paper will propose an alternative genotype-phenotype mapping for binary representation that introduces redundancy into the mapping and removes the exponential orderings between the alleles, hence improving the locality between the genotype and phenotype search space. Empirical study conducted based on distribution, locality, and mutation innovation revealed key algorithmic characteristics of the proposed code, and its practicality is validated by comparative studies based on different benchmark optimization problems. Possible approaches to resolve the overrepresentation problem due to redundancy will be suggested, exhibiting its flexibility and variability in implementation.

Tetrodotoxin poisoning: a clinical analysis, role of neostigmine and short-term outcome of 53 cases.

INTRODUCTION: Puffer fish (tetrodotoxin) poisoning is now a common form of poisoning throughout coastal countries, but its diagnosis and management are still unclear. In this paper, we aim to share our experience and to find out the toxic manifestations, lag period between ingestion of fish and development of symptoms, the short-term clinical outcome, and value of neostigmine in its management. METHODS: The study was carried out in the Department of Medicine and Paediatrics, Khulna Medical College Hospital, Khulna, Bangladesh, from May 1, 2001 to May 1, 2006. A total of 53 patients were admitted with the history of puffer fish ingestion. All the cases were clinically analysed from admission to discharge, for the following variables: Onset of symptoms in minutes after the ingestion of fish, toxic manifestations that developed after ingestion, relation of clinical outcome with approximate amount of fish ingested, and the role of neostigmine. RESULTS: All patients developed toxic manifestation. Important symptoms were perioral paraesthesia (38), weakness of all limbs (33), paraesthesia all over the body (34), headache (25), and difficulty in respiration. Eight patients died, probably due to respiratory muscle paralysis, of which five patients died immediately after admission. We used neostigmine in those patients who developed respiratory failure. 13 patients improved significantly (p-value is less than 0.5), while only three patients died. CONCLUSION: Because of the availability and affordability of puffer fish, the occurrence of tetrodotoxin poisoning throughout coastal countries is very likely. Therefore, health personnel should have enough knowledge regarding its toxic manifestations and management.

Peptic ulcer perforation: management of high-risk cases by percutaneous abdominal drainage.

Sixty-six patients were selected as high-risk cases of duodenal ulcer perforation. After resuscitation with intravenous fluids and nasogastric suction, a widebore percutaneous intra-abdominal drain was put in under local anaesthesia. There were three (4.5%) deaths; 58 (87.8%) patients improved satisfactorily. High-risk peptic ulcer perforation patients can be managed by putting in an intra-abdominal drain supported by conservative treatment.

A cost-minimization approach to planning the geographical distribution of health facilities.

This paper illustrates a method of planning the geographic distribution of health facilities in order to maximize the social benefits achievable from the investment. Data from Bangladesh have been used to determine the optimal distribution of emergency obstetric care (EOC) facilities in the country using the estimates of average social cost per woman. Costs incurred by households, including the costs associated with maternal mortality, tend to increase with increasing radius of a facility's catchment area. The average facility-based costs tend to decline with increasing radius due to lower per capita capital expenditures. The summation of these two average cost functions generates a U-shaped curve. In this research, the minimum point of the aggregated average cost curve defines the 'optimal' radius of a health facility. The catchment area defined by the optimal radius minimizes the average social cost of providing EOC services in a region. The empirical analysis suggests that the optimal radius for the 20 regions of Bangladesh varies from about 6 to 12 km. If the optimal radius of the catchment area is used in planning health centre locations, Bangladesh will need to set up 450 EOC facilities; currently there are only 90 such facilities.

Characterization of cryptic flagellin genes in Shigella boydii and Shigella dysenteriae.

Flagellin (fliC) genes of 12 Shigella boydii and five Shigella dysenteriae strains were characterized. Though these strains are nonmotile, the cryptic fliCSB gene, cloned from S. boydii strain C3, is functional for expression of flagellin. It consists of 1,704 bp, and encodes 568 amino acid residues (57,918 Da). The fliCSD gene from S. dysenteriae strain 16 consists of 1,650 bp encoding 549 amino acid residues (57,591 Da) and contains an IS1 element inserted in its 3' end. The two genes are composed of the 5'-constant, central variable and 3'-constant sequences, like other known fliC genes. The two genes share high homology in nucleotide and amino acid sequences with each other and also with the Escherichia coli fliCE gene, indicating that both genes are closely related to the fliCE gene. Comparison of the central variable sequences of six different fliC genes showed that the fliCSB and fliCSD genes share low homology in amino acid sequence with the other fliC genes, suggesting that they encode antigenic determinants intrinsic to respective subgroups. However, Southern blotting using as probes the central variable sequences of several fliC genes showed that four of 12 S. boydii strains have a fliC gene similar to that of Shigella flexneri, and that among five fliC genes from S. dysenteriae strains, one is similar to that of S. flexneri, two are similar to that of S. boydii, and only one is unique to S. dysenteriae. Some of these variant alleles were verified by immunoblotting with flagellins produced from cloned fliC genes. The presence of variant fliC alleles in S. boydii and S. dysenteriae indicates that subdivision into subgroups does not reflect the ancestral flagella H antigenic relationships. These data will be useful in considering the evolutionary divergence of the Shigella spp..

The Escherichia coli UVM response is accompanied by an SOS-independent error-prone DNA replication activity demonstrable in vitro.

UVM is an SOS-independent inducible response characterized by elevated mutagenesis at a site-specific 3, N4-ethenocytosine (epsilonC) residue borne on M13 single-stranded DNA transfected into Escherichia coli cells pretreated with DNA-damaging agents. By constructing and using E. coli strain AM124 (polA polB umuDC dinB lexA1[Ind-]), we show here that the UVM response is manifested in cells deficient for SOS induction, as well as for all four of the 'non-replicative' DNA polymerases, namely DNA polymerase I (polA), II (polB), IV (dinB) and V (umuDC). These results confirm that UVM represents a novel, previously unidentified cellular response to DNA-damaging agents. To address the question as to whether the UVM response is accompanied by an error-prone DNA replication activity, we applied a newly developed in vitro replication assay coupled to an in vitro mutation analysis system. In the assay, circular M13 single-stranded DNA bearing a site-specific lesion is converted to circular double-stranded replicative-form DNA in the presence of cell extracts and nucleotide precursors under conditions that closely mimic M13 replication in vivo. The newly synthesized (minus) DNA strand is selectively amplified by ligation-mediated polymerase chain reaction (LM-PCR), followed by a multiplex sequence analysis to determine the frequency and specificity of mutations. Replication of DNA bearing a site-specific epsilonC lesion by cell extracts from uninduced E. coli AM124 cells results in a mutation frequency of about 13%. Mutation frequency is elevated fivefold (to 58%) in cell extracts from UVM-induced AM124 cells, with C --> A mutations predominating over C --> T mutations, a specificity similar to that observed in vivo. These results, together with previously reported data, suggest that the UVM response is mediated through the induction of a transient error-prone DNA replication activity and that a modification of DNA polymerase III or the expression of a previously unidentified DNA polymerase may account for the UVM phenotype.

Requirement for homologous recombination functions for expression of the mutA mistranslator tRNA-induced mutator phenotype in Escherichia coli.

Expression of the Escherichia coli mutA mutator phenotype requires recA, recB, recC, ruvA, and ruvC gene, but not recD, recF, recO, or recR genes. Thus, the recBCD-dependent homologous recombination system is a component of the signal pathway that activates an error-prone DNA polymerase in mutA cells.

Escherichia coli cells bearing mutA, a mutant glyV tRNA gene, express a recA-dependent error-prone DNA replication activity.

A base substitution mutation (mutA) in the Escherichia coli glyV tRNA gene potentiates asp --> gly mistranslation and confers a strong mutator phenotype that is SOS independent, but requires recA, recB and recC genes. Here, we demonstrate that mutA cells express an error-prone DNA polymerase by using an in vitro experimental system based on the conversion of phage M13 single-stranded viral DNA bearing a model mutagenic lesion to the double-stranded replicative form. Amplification of the newly synthesized strand followed by multiplex DNA sequence analysis revealed that mutation fixation at 3, N4-ethenocytosine (varepsilonC) was approximately 3% when the DNA was replicated by normal cell extracts, approximately 48% when replicated by mutA cell extracts and approximately 3% when replicated by mutA recA double mutant cell extracts, in complete agreement with previous in vivo results. Mutagenesis at undamaged DNA sites was significantly elevated by mutA cell-free extracts in the M13 lacZ(alpha) forward mutagenesis system. Neither polA (DNA polymerase I) nor polB (DNA polymerase II) genes are required for the mutA phenotype, suggesting that the phenotype is mediated through a modification of DNA polymerase III or the activation of a previously unidentified DNA polymerase. These findings define the major features of a novel mutagenic pathway and imply the existence of previously unrecognized links between translation, recombination and replication.

The mutA mistranslator tRNA-induced mutator phenotype requires recA and recB genes, but not the derepression of lexA-regulated functions.

The mapping of mutA and mutC mutator alleles to the glyV and glyW glycine tRNA genes, respectively, and the subsequent discovery that the mutA phenotype is abolished in a DeltarecA strain raise the possibility that asp --> gly misinsertion may induce a novel mutagenic pathway. The recA requirement suggests three possibilities: (i) the SOS mutagenesis pathway is activated in mutA cells; (ii) loss of recA function interferes with mutA-promoted asp --> gly misinsertion; or (iii) a hitherto unrecognized recA-dependent mutagenic pathway is activated by translational stress. By assaying the expression levels of a reporter plasmid bearing a umuC :lacZ fusion, we show that the SOS regulon is not in a derepressed state in mutA cells. Neither overexpression of the lexA gene through a multicopy plasmid nor replacement of the wild-type lexA allele with the lexA1[Ind-] allele interferes with the expression of the mutA phenotype. The mutA phenotype is unaffected in cells defective for dinB, as shown here, and is unaffected in cells defective for umuD and umuC genes, as shown previously. We show that mutA-promoted asp --> gly misinsertion occurs in recA- cells and, therefore, the requirement for recA is 'downstream' of mistranslation. Finally, we show that the mutA phenotype is abolished in cells deficient for recB, suggesting that cellular recombination functions may be required for the expression of the mutator phenotype. We propose that translational stress induces a previously unrecognized mutagenic pathway in Escherichia coli.

Fertility and its proximate determinants in Bangladesh: evidence from the 1993/94 Demographic and Health Survey.

PIP: This study examined determinants of fertility in Bangladesh. Data were obtained from the 1993-94 Bangladesh Demographic and Health Survey among a nationally representative 2-stage sample of 9640 ever-married females aged 10-49 years. Findings indicate that the age-specific marital fertility rate was highest among women aged 15-19 years. The total fertility rate was 3.44 births/woman in 1993-94 and 5.12 births/woman in 1989. The interval between marriage and first birth declined more for younger cohorts. The proportion of women who had a child within 5 years increased. Over 60% were married under the age of 14 years. The proportion currently married has remained stable since 1981. The number of those never married has increased, especially among women aged 15-19 years. 44.6% of currently married women used family planning; 36.2% used modern methods and 8.4% used traditional ones. Prevalence was highest for the pill, followed by female sterilization. 48% of infants were breast-fed on the first day. Breast-feeding duration averaged 30 months. Duration of postpartum amenorrhea averaged 12 months. 0.5% reported induced abortion. Analysis of proximate determinants indicates that contraception accounted for 39.0% of fertility decline; lactational infecundability accounted for 34.7%. Marriage patterns accounted for 23.9%. The fertility inhibition of contraception varied by religion. Contraception had the highest impact among higher educated, upper class, urban, and non-Muslim women. Lactational infecundability had the highest impact among poor, nonworking, illiterate, and non-Muslim women.^ieng

Cloning and characterization of the region III flagellar operons of the four Shigella subgroups: genetic defects that cause loss of flagella of Shigella boydii and Shigella sonnei.

To detect genetic defects that might have caused loss of flagella in Shigella boydii and Shigella sonnei, the region III flagellar (fli) operons were cloned from certain strains and analyzed with reference to the restriction maps and genetic maps of Escherichia coli fli operons. S. boydii NCTC9733 (strain C5 in this paper) had the 988-bp internal deletion in the fliF gene that encodes a large substructural protein of the basal body. Two strains (C1 and C8) had deletions of the entire fliF operon, and the remaining three (C3, C4, and C9) differed in the size of the restriction fragments carrying the fliF and fliL operons. Loss of flagella in S. boydii appears to originate in some defect in the fliF operon. S. sonnei IID969 lacked the fliD gene and, in place of it, carried two IS600 elements as inverted repeats. Genes downstream from fliD were not detected in the cloned fragment despite its large size but did appear elsewhere in the chromosome. The fliD gene encodes a cap protein of the flagellar filament, and its deletion results in overexpression of class 3 operons by the increased amount of FliA (sigmaF) caused by the excess export of the anti-sigma factor FlgM. Three other strains also had the fliD deletion, and two of them had another deletion in the fliF-fliG-fliH region. The fliD deletion might be the primary cause of loss of flagella in S. sonnei. The lack of FliF or FliD in each subgroup is discussed in connection with the maintenance of virulence and bacterial growth. We also discuss the process of loss of flagella in relation to transposition of IS elements and alterations of the noncoding region, which were found to be common to at least three subgroups.

Detection and characterization of the flagellar master operon in the four Shigella subgroups.

Strains in the genus Shigella are nonmotile, but they retain some cryptic flagellar operons whether functional or defective (A.Tominaga, M. A.-H. Mahmoud, T. Mukaihara, and M. Enomoto, Mol. Microbiol. 12:277-285, 1994). To disclose the cause of motility loss in shigellae, the presence or defectiveness of the flhD and flhC genes, composing the master operon whose mutation causes inactivation of the entire flagellar regulon, was examined in the four Shigella subgroups. The flhD operon cloned from Shigella boydii and Shigella sonnei can activate, though insufficiently, the regulon in the Escherichia coli flhD or flhC mutant background. The clone from Shigella dysenteriae has a functional flhD gene and nonfunctional flhC gene, and its inactivation has been caused by the IS1 element inserted in its 5' end. The operon of Shigella flexneri is nonfunctional and has suffered an IS1-insertion mutation at the 5' end of the flhD gene. Comparison of restriction maps indicates that only the central 1.8-kb region, including part of the flhC gene and its adjacent mot operon, is conserved among the four Shigella subgroups as well as in E. coli, but in Salmonella typhimurium the whole map is quite different from the others. Motility loss in shigellae is not attributable to genetic damage in the master operon of a common ancestor, but it occurs separately in respective ancestors of the four subgroups, and in both S. dysenteriae and S.flexneri IS1 insertion in the master operon might be the primary cause of motility loss.

Molecular cloning of the wild-type and mutant thyA gene from Shigella flexneri Y.

The thyA gene which codes for thymidylate synthase has been cloned and sequenced from the wild-type Shigella flexneri Y strain SH4 and a thyA mutant TSF21 after amplifying the gene by polymerase chain reaction (PCR). The nucleotide sequence revealed 98% homology to the E. coli K-12 thyA gene. The sequence of the wild-type thyA gene of Shigella flexneri Y was identical with that of the thyA mutant except that the residue T at position 345 was replaced by residue A in the thyA mutant. This change would cause a predicted amino acid substitution of leucine at position 44 in the polypeptide product of the wild type by glutamine in the mutant. Thus, Leu44 may be critical in enzymatic activity of the thyA gene product thymidylate synthase.