Temporal alterations of <Emphasis Type="Italic">Nannochloropsis</Emphasis><Emphasis Type="Italic">salina</Emphasis> (Eustigmatophyceae) grown under aqueous diesel fuel stress

The influence of an aqueous extract of diesel fuel was tested on growth of the marine eustigmatophyte Nannochloropsis (Monallantus) salina Hibberd. An increase in the concentration of the pollutant led to a decrease in growth rate as measured by optical density, with maximum effect observed (33% of control) at 100% aqueous pollutant. Spectrophotometric examination of cell viability (using Evan’s blue dye) showed a significant negative effect of the diesel extract (p ≤ 0.05, r = −0.92). Infrared spectra showed a slight change in the absorbance of contaminated compared with controlled cells. Proteome analysis (sodium dodecyl sulfate polyacrylamide gel electrophoresis – “SDS-PAGE”) indicated that cell protein profiles depended on the pollutant concentration. Some of the resultant bands were characteristic to the pollutant concentration applied, indicating a distinct effect of the pollutant on the proteome structure. Iodine and toluidine blue dyes were applied using light microscopy to detect starch and mucilage, respectively. This indicated the presence of starch during all treatments, while the mucilage has been reduced. Transmission electron microscopy showed alterations to cell walls and membranes with different degrees of plasmolysis leading to a gradual increase in cell volume. However, the nucleus, the nucleolus and the pyrenoid remained unaffected. Similar results were obtained when the alga was cultured for 25 days in the 100% aqueous diesel extract indicating that long-term culture does not affect the degree of pollutant stress. Further, these cells recovered their normal appearance and characteristics within two days of being transferred to culture medium free of extract, indicating that N. salina shows a high tolerance to aqueous diesel fuel pollution.     

Gene diversity in some Muslim populations of North India

North Indian Muslim populations have historical, linguistic, and socioreligious significance to the Indian subcontinent. Although sociocultural and political dimensions of their demography are well documented, no detailed genetic structure of the populations is available. We have undertaken a survey of the gene frequencies of the ABO, Rh, PTC taste ability, sickling, and G6PD systems for different endogamous groups: Sheikh, Syed, Pathan, Ansari, Saifi, and Hindu Bania. All the groups at most loci showed statistically nonsignificant differences, except for ABO and PTC traits, for which interpopulational differences were seen. Heterozygosity ranged from 0.048 to 0.617 among the Sheikh, 0.149 to 0.599 among the Pathan, 0.105 to 0.585 among the Ansari, 0.25 to 0.869 among the Syed, 0.107 to 0.565 among the Saifi, and 0.100 to 0.492 among the Hindu Bania. The average D(ST) and G(ST) values for the five marker loci were 0.0625 +/- 0.098 and 0.1072 +/- 0.041, respectively. A dendrogram was constructed using the UPGMA clustering method. Our results revealed that the Pathan and the Sheikh form one cluster, the Syed and the Hindu Bania form another cluster, and the two clusters join together (the so-called higher caste); also, the Saifi and the Ansari form a separate cluster (lower caste). The results of the genetic distance analysis are useful for understanding the pattern of genetic relationships between different endogamous groups of Muslims.     

Ability of cytosolic malate dehydrogenase and lactate dehydrogenase to increase the ratio of NADPH to NADH oxidation by cytosolic glycerol-3-phosphate dehydrogenase

At the normal pH of the cytosol (7.0 to 7.1) and in the presence of physiological (1.0 mM) levels of free Mg2+, the Vmax of the NADPH oxidation is only slightly lower than the Vmax of NADH oxidation in the cytosolic glycerol-3-phosphate dehydrogenase (E.C. 1.1.1.8) reaction. Under these conditions physiological (30 microM) levels of cytosolic malate dehydrogenase (E.C. 1.1.1.37) inhibited oxidation of 20 microM NADH but had no effect on oxidation of 20 microM NADPH by glycerol-3-phosphate dehydrogenase. Consequently malate dehydrogenase increased the ratio of NADPH to NADH oxidation of glycerol-3-phosphate dehydrogenase. On the basis of the measured KD of complexes between malate dehydrogenase and these reduced pyridine nucleotides, and their Km in the glycerol-3-phosphate dehydrogenase reactions, it could be concluded that malate dehydrogenase would have markedly inhibited NADPH oxidation and inhibited NADH oxidation considerably more than observed if its only effect were to decrease the level of free NADH or NADPH. This indicates that due to the opposite chiral specificity of the two enzymes with respect to reduced pyridine nucleotides, complexes between malate dehydrogenase and NADH or NADPH can function as substrates for glycerol-3-phosphate dehydrogenase, but the complex with NADH is less active than free NADH, while the complex with NADPH is as active as free NADPH. Mg2+ enhanced the interactions between malate dehydrogenase and glycerol-3-phosphate dehydrogenase described above. Lactate dehydrogenase (E.C. 1.1.1.27) had effects similar to those of malate dehydrogenase only in the presence of Mg2+. In the absence of Mg2+, there was no evidence of interaction between lactate dehydrogenase and glycerol-3-phosphate dehydrogenase.     

The efficient role of aquatic plant (water hyacinth) in treating domestic wastewater in continuous system

In this study, water hyacinth (Eichhornia crassipes) was used to treat domestic wastewater. Ten organic and inorganic parameters were monitored in three weeks for water purification. The six chemical, biological and physical parameters included Dissolved Oxygen (DO), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Ammoniacal Nitrogen (NH₃-N), Total Suspended Solids (TSS), and pH were compared with the Interim National Water Quality Standards, Malaysia River classification (INWQS) and Water Quality Index (WQI). Between 38% to 96% of reduction was observed and water quality has been improved from class III and IV to class II. Analyses for Electricity Conductivity (EC), Salinity, Total Dissolved Solids (TDS) and Ammonium (NH₄) were also investigated. In all parameters, removal efficiency was in range of 13–17th day (optimum 14th day) which was higher than 3 weeks except DO. It reveals the optimum growth rate of water hyacinth has great effect on waste water purification efficiency in continuous system and nutrient removal was successfully achieved.     

Leptin promoter variant G2548A is associated with serum leptin and HDL-C levels in a case control observational study in association with obesity in a Pakistani cohort

Leptin is a protein hormone synthesized by adipocytes and is involved in the regulation of food intake and energy expenditure. We hypothesized that any change in the promoter sequence can affect the expression of the gene and hence leptin protein levels in the serum. The aim of the current study was to investigate the relationship of such a promoter variant of the leptin gene, G-2548A polymorphism, with obesity and its effect on various anthropometric and metabolic parameters in a Pakistani cohort consisting of 250 obese and 225 non-obese control subjects. Body weight, height, waist circumference (WC), hip circumference (HC) and blood pressure (BP) were measured by standard methods and levels of fasting blood glucose (FBG), total cholesterol, triglycerides, HDLC, LDLC, and leptin were determined. Genotyping was done by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The results showed that the LEP G-2548A polymorphism showed significant association with obesity in Pakistan. In addition, the polymorphism showed association with weight, height, BMI, WC, HDLC and serum leptin levels. The findings suggest that the leptin promoter G-2548A variant may play its part in the progression to obesity by not only affecting the body’s fat distribution but also by changing the serum leptin and HDLC levels.     

Arsenic and heavy metals health risk assessment through drinking water consumption in the Peshawar District,Pakistan

This study aimed to assess the drinking water quality and human potential health risk in Peshawar, which is the most populous district of Khyber Pakhtunkhwa Province, Pakistan. Water was randomly collected throughout Peshawar District (urban = 45 samples and rural = 29 samples). These samples were analyzed for heavy metal (As, Cd, Co, Cu, Cr, Hg, Ni, Pb, and Zn) concentrations using the atomic absorption spectrometer (Perkin Elmer, AAS-PEA-700). Heavy metal concentrations in drinking water revealed the highest pollution index (PI) values—17.80, 11.92, 7.50, and 5.70 for the Pb, Cr, Cd, and Ni, respectively. The contaminations of Cd and Pb were significantly higher (p < .05) than their maximum allowable limits set by the World Health Organization. Heavy metal contaminations in drinking water were evaluated for health risk assessment: the chronic risk or hazard quotient (HQ) and cancer risk. Results revealed that HQ values were >1 for the Cd and Pb, suggesting that the exposed human beings could be at chronic risk. Therefore, serious measures such as drinking water treatments and contamination controlling policies are needed to avoid the hazardous effects of toxic heavy metals.     

The effect of selenium and vitamin E on microvascular permeability of rat organs

The effects of dietary sodium selenite and vitamin E on the microvascular permeability of rat organs such as heart, brain, kidney, liver and eye were investigated by using the Evans blue leakage method. Combined deficiency of selenium and vitamin E caused an increase in the permeability of the heart and eye with respect to their controls while it had no considerable effect on the permeability of other organs. On the other hand, toxic levels of selenium (4.2 mg/kg) in diet decreased the permeabilities in kidney, liver, and eye whereas this parameter of brain increased in the same animal group. These results suggested that low or high sodium selenite and vitamin E contents in diet could alter the microvascular permeability of different organs in different manners. It might be important to give reasonable explanations for the pathophysiology of some diseases that are characterized with organ damage and /or disfunction originated from selenium deficiency or toxicity.     

Enhancement of biological treatment performance of saline wastewater by halophilic bacteria

Performances of biological treatment processes of saline wastewater are usually low because of adverse effects of salt on microbial flora. High salt concentrations in wastewater cause plasmolysis and loss of activity of cells resulting in low COD removal efficiencies. In order to improve biological treatment performance of saline wastewater, a halophilic organism Halobacter halobium was used along with activated sludge culture.A synthetic wastewater composed of diluted molasses, urea, KH₂PO₄ and various concentrations of salt (1%–5% NaCl) was treated in an aerobic-biological reactor by fed-batch operation. Activated sludge culture with and without Halobacter were used as seed cultures. Variations of COD removal rate and efficiency with salt concentration were determined for both cultures and results were compared. Inclusion of Halobacter into activated sludge culture resulted in significant improvements in COD removal efficiency. A rate expression including salt inhibition effect was proposed and kinetic constants were determined by using experimental data.This study was supported by the Technical and Scientific Research Council of Turkey.     

chs-4, a class IV chitin synthase gene fromNeurospora crassa

InSaccharomyces cerevisiae, most of the cellular chitin is produced by chitin synthase III, which requires the product encoded by theCSD2/CAL1/DIT101/KT12 gene. We have identified, isolated and structurally characterized aCSD2/CAL1/DIT101/KT12 homologue in the filamentous ascomyceteNeurospora crassa and have used a “reverse genetics” approach to determine its role in vivo. The yeast gene was used as a heterologous probe for the isolation of aN. crassa gene (designatedchs-4) encoding a polypeptide belonging to a class of chitin synthases which we have designated class IV. The predicted polypeptide encoded by this gene is highly similar to those ofS. cerevisiae andCandida albicans. N. crassa strains in whichchs-4 had been inactivated by the Repeat-Induced Point mutation (RIP) process grew and developed in a normal manner under standard growth conditions. However, when grown in the presence of sorbose (a carbon source which induces morphological changes accompanied by elevated chitin content), chitin levels in thechs-4 ^RIP strain were significantly lower than those observed in the wild type. We suggest that CHS4 may serve as an auxiliary enzyme inN. crassa and that, in contrast to yeasts, it is possible that filamentous fungi may have more than one class IV chitin synthase.