Isolation and Characterization of A Metal-resistant Pseudomonas Aeruginosa Strain

Summary The use of microorganisms to remove heavy metals from industrial effluent is an area of extensive research and development. Attempts have been made to isolate and characterize metal-resistant microorganisms from treated oil mill industry effluent wastewater samples. The metal-resistant organisms that showed values of minimum inhibitory concentration towards metals (Cd, Cr, Ni and Pb) ranging from 100 to 800 ppm level were screened. A potent metal-resistant organism, isolate BC15 from the wastewater samples was tentatively identified as Pseudomonas sp. Detailed analysis of morphological, biochemical and 16S rDNA sequence of the isolate revealed that it is closely related to Pseudomonas aeruginosa (94%). Pseudomonas BC15 was capable of absorbing 93% Ni, 65% Pb, 50% Cd and 30% Cr within 48 h from the medium containing 100 mg of each heavy metal per liter. The multiple metal tolerance of this strain was also associated with resistance to antibiotics such as ampicillin, tetracycline, chloramphenicol, erythromycin, kanamycin and streptomycin.     

Role of glutathione on renal mitochondrial status in hyperoxaluria

Role of glutathione on kidney mitochondrial integrity and function during stone forming process in hyperoxaluric state was investigated in male albino rats of Wistar strain. Hyperoxaluria was induced by feeding ethylene glycol (EG) in drinking water. Glutathione was depleted by administering buthionine sulfoximine (BSO), a specific inhibitor of glutathione biosynthesis. Glutathione monoester (GME) was administered for supplementing glutathione. BSO treatment alone or along with EG, depleted mitochondrial GSH by 40% and 51% respectively. Concomitantly, there was remarkable elevation in lipid peroxidation and oxidation of protein thiols. Mitochondrial oxalate binding was enhanced by 74% and 129% in BSO and BSO + EG treatment. Comparatively, EG treatment produced only a 33% increase in mitochondrial oxalate binding. Significant alteration in calcium homeostasis was seen following BSO and BSO + EG treatment. This may be due to altered mitochondrial integrity and function as evidenced from decreased activities of mitochondrial inner membrane marker enzymes, succinate dehydrogenase and cytochrome-c-oxidase and respiratory control ratio and enhanced NADH oxidation by mitochondria in these two groups. NADH oxidation (r = -0.74) and oxalate deposition in the kidney (r = -0.70) correlated negatively with mitochondrial glutathione depletion. GME supplementation restored normal level of GSH and maintained mitochondrial integrity and function, as a result of which oxalate deposition was prevented despite hyperoxaluria. These results suggest that mitochondrial dysfunction resulting from GSH depletion could be a contributing factor in the development of calcium oxalate stones.     

Low frequency and low intensity pulsed electromagnetic field exerts its antiinflammatory effect through restoration of plasma membrane calcium ATPase activity

Rheumatoid arthritis (RA) is a chronic inflammatory disorder affecting 1% of the population worldwide. Pulsed electromagnetic field (PEMF) has a number of well-documented physiological effects on cells and tissues including antiinflammatory effect. This study aims to explore the antiinflammatory effect of PEMF and its possible mechanism of action in amelioration of adjuvant induced arthritis (AIA). Arthritis was induced by a single intradermal injection of heat killed Mycobacterium tuberculosis at a concentration of 500 μg in 0.1 ml of paraffin oil into the right hind paw of rats. The arthritic animals showed a biphasic response regarding changes in the paw edema volume. During the chronic phase of the disease, arthritic animals showed an elevated level of lipid peroxides and depletion of antioxidant enzymes with significant radiological and histological changes. Besides, plasma membrane Ca²⁺ ATPase (PMCA) activity was inhibited while intracellular Ca²⁺ level as well as prostaglandin E₂ levels was noticed to be elevated in blood lymphocytes of arthritic rats. Exposure of arthritic rats to PEMF at 5 Hz × 4 μT × 90 min, produced significant antiexudative effect resulting in the restoration of the altered parameters. The antiinflammatory effect could be partially mediated through the stabilizing action of PEMF on membranes as reflected by the restoration of PMCA and intracellular Ca²⁺ levels in blood lymphocytes subsequently inhibiting PGE₂ biosynthesis. The results of this study indicated that PEMF could be developed as a potential therapy for RA in human beings.     

Supplementation of vitamin E and selenium prevents hyperoxaluria in experimental urolithic rats

Renal injury is considered as one of the prerequisites for calcium oxalate retention. In order to determine the role of lipid peroxidation related effects for hyperoxaluria, we evaluated the alterations in lipid peroxidation, antioxidants and oxalate synthesizing enzymes in lithogenic rats with response to vitamin E + selenium treatment. In kidney of lithogenic rats, the level of lipid peroxidation and the activities of oxalate synthesizing enzymes were found to be increased whereas the levels/activities of non-enzymatic and enzymatic antioxidants were found to be decreased. The urinary excretion of both oxalate and calcium were significantly elevated. Supplementation of lithogenic rats with vitamin E + selenium decreased the levels of lipid peroxides and the activities of oxalate synthesizing enzymes like glycolic acid oxidase (GAO), lactate dehydrogenase (LDH), xanthine oxidase (XO) with a concomitant increase in the activities of enzymatic antioxidants like superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glucose-6-phosphate dehydrogenase (G6PDH) and increased levels of non-enzymatic antioxidants like ascorbic acid, alpha-tocopherol and reduced glutathione (GSH). The urinary excretion of oxalate and calcium were normalized. The antioxidants vitamin E + selenium thereby protected from hyperoxaluria.     

Cutaneous larva migrans among devotees of the Nallur temple in Jaffna, Sri Lanka

Background

Many cases of Cutaneous Larva Migrans (CLM) have been observed among devotees, during and immediately after the annual festival at the Nallur Hindu temple in Jaffna.

Objective

To ascertain the risk factors associated with infestation and devotees'' knowledge and practices regarding the condition.

Methodology/Principal Findings

A cross-sectional study using an interviewer-administered questionnaire and observation was conducted in August 2010. Out of 200 selected devotees 194(97%) responded. Soil and dog faecal samples were collected from the temple premises and examined for the presence of nematode larva and egg respectively. Among 194 male respondents, 58.2%(95% CI: 51.2%–65.0%) had lesions of CLM. One hundred and thirty (67%) respondents performed the ritual everyday; whereas 33% did so on special days. One hundred and twelve (57.7%) participants performed the ritual before 5.00am and remaining 42.3% performed after 5.00am. Among the participants, 77(36.7%) had the similar condition in previous years. One hundred and fifty seven (80.9%) were aware about this disease and 52(27%) devotees adopted some kind of precautionary measures. Bivariate analysis showed significant association between occurrence of CLM lesions and frequency of performing the ritual (p<0.001, OR-15.1; 95% CI:7.2-32.0), the timing of ritual performance (p = 0.022, OR-1.96; 95% CI:1.10–3.52), similar condition in previous year (p<0.001, OR-6.83; 95% CI: 3.39–13.76) and previous awareness of the condition (p = 0.005; OR-0.59;95% CI:0.43–0.82). Multivariate analysis showed that the frequency of ritual performance (OR-11.75; 95% CI 5.37–25.74) and similar conditions in previous years (OR-4.71; 95% CI: 2.14–10.39) were the independent risk factors. Two of the 20 soil samples were positive for the nematode larvae and three out of five dog faeces were positive for hookworm eggs.

Conclusions/Significance

Deworming the stray dogs around the temple premises combined with the awareness programs among the public may be the effective and feasible precautionary measures to control similar epidemics in future.     

Prevalence of Diabetes and Pre-Diabetes and Associated Risk Factors among Tuberculosis Patients in India

Background

Diabetes mellitus (DM) is recognised as an important risk factor to tuberculosis (TB). India has high TB burden, along with rising DM prevalence. There are inadequate data on prevalence of DM and pre-diabetes among TB cases in India. Aim was to determine diabetes prevalence among a cohort of TB cases registered under Revised National Tuberculosis Control Program in selected TB units in Tamil Nadu, India, and assess pattern of diabetes management amongst known cases.

Methods

827 among the eligible patients (n = 904) underwent HbA1c and anthropometric measurements. OGTT was done for patients without previous history of DM and diagnosis was based on WHO criteria. Details of current treatment regimen of TB and DM and DM complications, if any, were recorded. A pretested questionnaire was used to collect information on sociodemographics, habitual risk factors, and type of TB.

Findings

DM prevalence was 25.3% (95% CI 22.6–28.5) and that of pre-diabetes 24.5% (95% CI 20.4–27.6). Risk factors associated with DM among TB patients were age (31–35, 36–40, 41–45, 46–50, >50 years vs <30 years) [OR (95% CI) 6.75 (2.36–19.3); 10.46 (3.95–27.7); 18.63 (6.58–52.7); 11.05 (4.31–28.4); 24.7 (9.73–62.7) (p<0.001)], positive family history of DM [3.08 (1.73–5.5) (p<0.001)], sedentary occupation [1.69 (1.10–2.59) (p = 0.016)], and BMI (18.5–22.9, 23–24.9 and ≥25 kg/m² vs <18.5 kg/m²) [2.03 (1.32–3.12) (p = 0.001); 0.87 (0.31–2.43) (p = 0.78); 1.44 (0.54–3.8) (p = 0.47)]; for pre-diabetes, risk factors were age (36–40, 41–45, 46–50, >50 years vs <30 years) [2.24 (1.1–4.55) (p = 0.026); 6.96 (3.3–14.7); 3.44 (1.83–6.48); 4.3 (2.25–8.2) (p<0.001)], waist circumference [<90 vs. ≥90 cm (men), <80 vs. ≥80 cm (women)] [3.05 (1.35–6.9) (p = 0.007)], smoking [1.92 (1.12–3.28) (p = 0.017)] and monthly income (5000–10,000 INR vs <5000 INR) [0.59 (0.37–0.94) (p = 0.026)]. DM risk was higher among pulmonary TB [3.06 (1.69–5.52) (p<0.001)], especially sputum positive, than non-pulmonary TB.

Interpretation

Nearly 50% of TB patients had either diabetes or pre-diabetes.     

Characterisation of nuclear pore complex oxalate binding protein from human kidney

Both rat and human kidney nuclei exhibited time and pH dependent oxalate or histone-oxalate uptake which was inhibited by anion transport inhibitor, 4,4-dithiocyanostilbene-2,2-disulphonic acid. Sodium chloride had no effect. Nuclear membrane had oxalate binding at pH 7.4. Extraction of nuclear membrane by Triton–high salt mixture showed maximal oxalate binding activity with nuclear pore complex while nuclear lamin had no oxalate binding. The rat and human kidney nuclear pore complex showed oxalate binding of 144 and 220 pmoles/mg protein respectively. Subsequent purification of the protein on diethyl amino ethyl–Sephadex A 50 column and Sephadex G-200 column yielded 4-fold purification. The protein revealed a molecular weight of 205 kDa on SDS-PAGE. The protein was found to be saturable at 2 M oxalate and had a Kd of 2.98 pM and a Bmax of 197 pmoles. Antibody for 205 kD was separated from primary biliary cirrhosis serum containing auto antibody against 205 kDa using affinity column chromatography. The oxalate binding activity as well as the nuclear uptake of oxalate or histone-oxalate were inhibited by its antibody.