Screening of three phenol-degrading bacteria for copper bioremoval of copper

Aim: Potential microbial isolates for bioremoval of copper were collected from phenolic and heavy metal-contaminated soils and screened in copper-containing medium for determining the maximum tolerance level for copper. Methodology: Bioremoval of copper was assessed using sodium diethyl dithiocarbamate assay. Physical and cultural conditions influencing copper bioremoval such as initial concentration, biomass dosage (inoculum volume), temperature and pH were optimised via one-factor-at-a-time. Results: The highest maximum tolerance level was displayed by Serratia sp. AQ5-03 at 600 mg l-1, while for Alcaligenes sp. AQ5-02 and Pseudomonas sp. AQ5-04 it was 500 mg l-1. The highest bioremoval for Alcaligenes sp. AQ5-02, Serratia sp. AQ5-03 and Pseudomonas sp. AQ5-04 was achieved at 20, 50 and 75 mg l-1, respectively. The optimum biomass dosage (inoculum volume) for both Serratia sp. AQ5-03 and Pseudomonas sp. AQ5-04 were 15%, whereas it was 10% for Alcaligenes sp. AQ5-02. The results also revealed that maximum bioremoval was achieved at pH 6 at an optimum temperature of 20°C for both Alcaligenes sp. AQ5-02 and Pseudomonas sp. AQ5-04, while Serratia sp. AQ5-03 showed optimum removal at pH 7 and at 30°C temperature. The maximum bioremoval efficiency for Alcaligenes sp. AQ5-02, Serratia sp. AQ5-03 and Pseudomonas sp were found to be 62, 57 and 70%, respectively. Interpretation: The results indicate that Alcaligenes sp. AQ5-02, Serratia sp. AQ5-03, Pseudomonas sp. AQ5-04 can be utilised as bioremoval agent since it possessed the highest bioremoval efficiency for copper remediation.

Histopathological and cholinesterase changes in the gills of Clarias gariepinus as a result of cadmium exposure

Aim: The cholinesterase (ChE) based inhibition and histopathological studies from fish were investigated and represented in this study to develop as one of the great potential biomarkers for heavy metals monitoring. Methodology: In this study, the histopathological study of gills were observed a under microscope. The capability of ChE extracted from the gills of Clarias gariepinus was assessed for declining Cd. ChE was purified through affinity chromatography and continued with the optimisation and inhibition study (IC50) of cholinesterase. Results: Histopathological study of gills was carried out and several changes such as aneurysm, necrosis and lamella fusion were noted. Purification fold obtained from purified enzyme was 1.15 with 30% a yield specific activity 20.726. The optimum temperature for purified AChE was 35°C along with acetylthiocholine iodide (ATC) as a preferable substrate that had the highest Vmax value of 0.5452 U mg-1 and the lowest Km value of 0.0311 mM. The optimum pH was observed to be 10 of Tris-HCl as a medium. Meanwhile, the IC50 of cadmium was 6.808 mg l-1 with R2 value of 0.9532. Interpretation: The result of the study can be used as a tool for further developing a biomarker for the detection of heavy metals in aquatic ecosystems. In addition, the baseline data provided can also be used for designing a kit, which would give rapid and accurate result.

Characterisation of cholinesterase and histopathological features of brain of Clarias gariepinus following exposure to cadmium

Aim: Cholinesterase (ChE) inhibition and histopathological features of brain tissues of Clarias gariepinus were investigated with a purpose to develop biomarkers for monitoring heavy metals. Methodology: The effects of cadmium toxicity on C. gariepinus were assessed by ChE inhibition and characterisation of ChE by affinity chromatography and histological variations in brain tissues were studied by H&E staining under light microscope. Results: The purified enzyme gave 10.58 fold purification with the recovery of 12% with specific activity of 159.729 U mg-1. The Michaelis-Menten constant (Km) and Vmax value obtained was 1.985 mM and 0.4479 µmol min-1 mg-1, respectively. The enzyme showed the ability to hydrolyse acetylthiocholine iodide (ATC) at a faster rate compared to other two synthetic substrates, propionylcholine iodide (PTC) and butyrylthiocholine iodide (BTC). ChE showed highest activity at 35°C in Tris-HCl pH 7.5. The metal inhibition study also found the maximal inhibitory concentration (IC50) value for cadmium to be 0.6517 mg l-1. Histological study revealed decrease in the number of cells, degeneration of Purkinje cells, increased aggregation area and cells necrosis. Interpretation: Inhibition of cholinesterase activity and degeneration of Purkinje cells observed in the present study can be used as a tool for further developing a biomarker for detecting heavy metals in the aquatic ecosystems.

Teachers Perception on Tobacco Free School in Bangladesh.

Introduction: Comprehensive tobacco-free school policy benefits everyone by reducing exposure to second-hand smoking and creating a system that reinforces tobacco-free norm and attitudes, which in turn affect tobacco use having an impact on the health of the community. Objective: This study aims to assess the perception of teachers on tobacco free school environments and factors supporting it. Methods: A two-stage cluster sampling technique was used for the selection of schools with selection probability proportional to enrolment size followed by stratified random sampling of government and private schools. Data were collected from 559 secondary school teachers using a structured questionnaire. Results: Estimation indicated that 48.3% (95% CI: 44.5%, 52.6%) of the teachers were less supportive and 51.7% (95% CI: 47.4%, 55.5%) were more supportive for smoking free school. Logistic regression analysis revealed that non tobacco user teachers were more likely to be supportive (OR=1. 891, 95% CI: 1.197, 2.986) for tobacco free school. However, no statistically significant association was found between perceived supportive tobacco free school and age, sex, level of education, type of school and family size (p>0.05). Exposure to second hand smoking and curriculum content of tobacco issues were not significantly related with tobacco free school. Conclusion: Comprehensive school based programme with participation of school personnel and community can effectively implement tobacco free school programmes.

Respiratory Health Problems Among the Ceramic Workers in Dhaka,.

Ceramic factory workers are potentially at risk to develop occupational respiratory diseases due to chronic inhalation of dust particles generated in the ceramic factory. A cross-sectional descriptive study was carried out to assess the respiratory and other health problems among the workers of Mirpur Ceramic Works Limited, Dhaka, Bangladesh during the period of April to June, 2011. Among 200 participants, 132 (66%) were males and 68 (34%) were females. Less than one-third of the workers were habituated to use personal protective equipments (PPE), while more than two-third were not habituated. Nearly half (45.5%) of the workers were suffering from at least one respiratory problem and of them 86.8% (P = 0.001) had problems after joining the factory. Of the respiratory sufferers 27% had chronic bronchitis, 20% bronchial asthma, 1% pulmonary tuberculosis, and 0.5% had silicosis. A significant numbers (60.5%) of workers were suffering from other health problems along with or without respiratory problems, in terms of musculoskeletal pain, back pain, headache, dermatitis, anaemia and fever. The prevalence of respiratory problems was significantly higher among non-users of PPE than PPE users (P = 0.006), and it was found to be higher with the increased of job duration. The study showed the notable higher prevalence of respiratory problems among the workers exposed to ceramic dust, although the other potential environmental confounding factors could not be ruled out in the analysis. Obligatory use of PPE by all workers and health education to increase awareness among the workers might have role to reduce the prevalence.

Assessment of Nutritional Status among Adolescent Garo in Sherpur District, Bangladesh.

Background: Garo is one of the largest indigenous communities of Bangladesh. Adolescence is a golden period of time for nutritional promotion. Adolescent nutrition did not receive adequate attention in Bangladesh. Tribal people like the Garo are even more unaware about the importance of adolescent nutrition. Objectives: To find out physical growth as well as nutritional status among adolescent Garo children in Sherpur district on the basis of anthropometric indices. Methods and materials: This cross sectional descriptive study was conducted among 384 adolescent Garo children (boys and girls) aged 10- 18 years. A structured pre-tested questionnaire and a checklist were used to collect data through interview. Anthropometric survey of randomly selected adolescent was carried out and compared against the NCHS/WHO reference indicators such as BMI-for-age, Height-for-age and Weight-for-age. Standard methods were applied to measure the height and weight of the adolescent and BMI was calculated. Associations of nutritional status with socio-economic status, maternal working status, family type and family size were determined. Results: In most of the age groups it is notable that the mean height and weight of both boys and girls were lower than the WHO/NCHS standards. The prevalence of thinness, stunting and underweighting was 49.74%, 15.1% and 7.29% respectively. Conclusions: Significant association between malnutrition and socio-economic parameters was observed. So socio-economic status, maternal working status, family type and family size are important determinants of nutritional status of adolescent. Therefore, comprehensive programmes are required to be undertaken for the overall nutritional development of the Garo population with special focus on the adolescents.

Reduction of hepatitis C virus load during low flux renal haemodialysis in patients with end stage renal disease infected with HCV

HCV infection remains a common problem in patients with end stage renal disease [ESRD] undergoing maintenance dialysis especially Haemodialysis [HD]. Inspite that dialysis patients usually are not immunologically competent due to uraemia, hepatitis C virus infection runs usually indolent course. A number of studies support the notion that this dynamics of HCV viral load may be related to lowering of HCV RNA titres during the HD procedure that could be related to the dialyser immaterial used. This work aimed mainly to study the change in HCV RNA titre before and after HD session using low flux dialyser. 18 HCV positive, end stage renal disease [ESRD] patients on regular HD with detectable viral RNA using qualitative polymerase chain reaction [PCR] technique were included. All patients had quantitative PCR just before and at the end of a single 4 hours HD session. Standard low flux [Cuprophan or Polysulphon] dialysis filters 1.2m[2] surface area were used for all patients included. Mean HCV RNA for all patients pre dialysis was 135, 143 +/- 16,993 copies/ml. Mean post dialysis HCV RNA was 78, 786 +/- 48,651 copies/ml. Observed reduction in HCV title post/pre dialysis ratio 13.8%-82.l% with median value of +/- 40%. There was a significant reduction in the level of HCV RNA after dialysis [p<0.001, 95% Confidence Interval 125, 332-144, 954]. Low flux haemodialysis session has a significant effect on hepatitis C viral load with marked reduction in HCV RNA that can have a positive impact on the prognosis of hepatitis C in ESRD on regular HD

Effect of haemofiltration in prevention of contrast induced nephropathy and on acid/base status in predialysis chronic kidney disease patients undergoing cardiac catheterization

High risk renal failure patients have increased risk for contrast nephropathy during coronary angiography despite the use of conventional prophylaxis with intravenous hydration and acetylcysteine. The aim of the study was assess the role of haemo filtration versus conventional prophylaxis in preservation of kidney function and prevention of contrast nephropathy in chronic kidney disease patients undergoing cardiac catheterisation. There was a highly significant reduction in BUN, creatinine, serum uric acid [p<0.001] in haemofiltration group in comparison with baseline and control group till day 4 that was not significant after one week. There was a significantly improving rise in pH and serum HCO[3] level in haemofiltration in haemofiltration group till 24 hours post contrast injection [p<0.001]. Haemofiltration can provide adequate pres ervation of kidney function in high risk renal patients under going cardiac catheterisation. It also achieved proper adjustment of acid/base status in such patients