Association of the ACE-II genotype with the risk of nephrotic syndrome in Pakistani children

Nephrotic syndrome is a common pediatric glomerular disease associated with heavy proteinuria. Since, the angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism is a putative genetic risk factor for NS, in this study, ACE (I/D) polymorphism was analyzed in 268 NS and 223 control samples by a PCR-based method. The genotypic and allelic frequencies were determined and the association between ACE I/D polymorphism and NS was evaluated. The frequency distribution of the II, ID and DD genotypes was 82 (30.6%), 128 (47.8%) and 58 (21.6%) in the NS patients and 9 (4.0%), 171 (76.7%) and 43 (19.3%) in the control samples respectively. In the Pakistani pediatric NS population, the II genotypic and allelic frequencies were found to be significantly associated with the disease (OR = 6.755; C.I = 3-14.9). No significant association was found between this polymorphism and the response to standard steroid therapy. Thus, in contrast to reports from other parts of the world, the II genotype was found to be significantly associated with NS in the Indian and Malay populations and in the Pakistani population described here. To our knowledge, this is the first report from Pakistan describing the association of the ACE I/D polymorphism with pediatric NS. On the basis of these results, it is suggested that analysis of the ACE (I/D) polymorphism should be performed for the early diagnosis in the high risk NS patients in South Asia.     

Ecology of Vibrio parahaemolyticus and Vibrio vulnificus in the Coastal and Estuarine Waters of Louisiana,Maryland, Mississippi,and Washington (United States)

Vibrio parahaemolyticus and Vibrio vulnificus, which are native to estuaries globally, are agents of seafood-borne or wound infections, both potentially fatal. Like all vibrios autochthonous to coastal regions, their abundance varies with changes in environmental parameters. Sea surface temperature (SST), sea surface height (SSH), and chlorophyll have been shown to be predictors of zooplankton and thus factors linked to vibrio populations. The contribution of salinity, conductivity, turbidity, and dissolved organic carbon to the incidence and distribution of Vibrio spp. has also been reported. Here, a multicoastal, 21-month study was conducted to determine relationships between environmental parameters and V. parahaemolyticus and V. vulnificus populations in water, oysters, and sediment in three coastal areas of the United States. Because ecologically unique sites were included in the study, it was possible to analyze individual parameters over wide ranges. Molecular methods were used to detect genes for thermolabile hemolysin (tlh), thermostable direct hemolysin (tdh), and tdh-related hemolysin (trh) as indicators of V. parahaemolyticus and the hemolysin gene vvhA for V. vulnificus. SST and suspended particulate matter were found to be strong predictors of total and potentially pathogenic V. parahaemolyticus and V. vulnificus. Other predictors included chlorophyll a, salinity, and dissolved organic carbon. For the ecologically unique sites included in the study, SST was confirmed as an effective predictor of annual variation in vibrio abundance, with other parameters explaining a portion of the variation not attributable to SST.     

Role of active site rigidity in activity: MD simulation and fluorescence study on a lipase mutant

Relationship between stability and activity of enzymes is maintained by underlying conformational flexibility. In thermophilic enzymes, a decrease in flexibility causes low enzyme activity while in less stable proteins such as mesophiles and psychrophiles, an increase in flexibility is associated with enhanced enzyme activity. Recently, we identified a mutant of a lipase whose stability and activity were enhanced simultaneously. In this work, we probed the conformational dynamics of the mutant and the wild type lipase, particularly flexibility of their active site using molecular dynamic simulations and time-resolved fluorescence techniques. In contrast to the earlier observations, our data show that active site of the mutant is more rigid than wild type enzyme. Further investigation suggests that this lipase needs minimal reorganization/flexibility of active site residues during its catalytic cycle. Molecular dynamic simulations suggest that catalytically competent active site geometry of the mutant is relatively more preserved than wild type lipase, which might have led to its higher enzyme activity. Our study implies that widely accepted positive correlation between conformation flexibility and enzyme activity need not be stringent and draws attention to the possibility that high enzyme activity can still be accomplished in a rigid active site and stable protein structures. This finding has a significant implication towards better understanding of involvement of dynamic motions in enzyme catalysis and enzyme engineering through mutations in active site.     

Histological alterations in the liver of rats induced by different gold nanoparticle sizes,doses and exposure duration

Background  

Nanoparticles (NPs) can potentially cause adverse effects on organ, tissue, cellular, subcellular and protein levels due to their unusual physicochemical properties. Advances in nanotechnology have identified promising candidates for many biological and biomedical applications. Since the properties of NPs differ from that of their bulk materials, they are being increasingly exploited for medical uses and other industrial applications. The aim of the present study was to investigate the particle-size effect of gold nanoparticles (GNPs) on the hepatic tissue in an attempt to cover and understand the toxicity and the potential threat of their therapeutic and diagnostic use.     

Staphylococcus aureus induces eosinophil cell death mediated by α-hemolysin

Staphylococcus aureus, a major human pathogen, exacerbates allergic disorders, including atopic dermatitis, nasal polyps and asthma, which are characterized by tissue eosinophilia. Eosinophils, via their destructive granule contents, can cause significant tissue damage, resulting in inflammation and further recruitment of inflammatory cells. We hypothesised that the relationship between S. aureus and eosinophils may contribute to disease pathology. We found that supernatants from S. aureus (SH1000 strain) cultures cause rapid and profound eosinophil necrosis, resulting in dramatic cell loss within 2 hours. This is in marked contrast to neutrophil granulocytes where no significant cell death was observed (at equivalent dilutions). Supernatants prepared from a strain deficient in the accessory gene regulator (agr) that produces reduced levels of many important virulence factors, including the abundantly produced α-hemolysin (Hla), failed to induce eosinophil death. The role of Hla in mediating eosinophil death was investigated using both an Hla deficient SH1000-modified strain, which did not induce eosinophil death, and purified Hla, which induced concentration-dependent eosinophil death via both apoptosis and necrosis. We conclude that S. aureus Hla induces aberrant eosinophil cell death in vitro and that this may increase tissue injury in allergic disease.     

Immunohistochemical localization and morphometry of somatotrophs and lactotrophs in protein,probiotic and symbiotic supplemented molted layers

Two hundred Single Comb White Leg-Horn spent hens at the age of 70 weeks were purchased from a commercial layer farm. The birds were shifted to the Poultry Research Station, Department of Physiology and Pharmacology, University of Agriculture, Faisalabad, Pakistan. High dietary zinc (3 g/kg feed/day) was used to induce molting in all the birds after one week of acclimatization. Thereafter, birds were divided in groups of 50 birds each, with the following treatments: G1 [control; crude protein (CP)16%, no other supplement], G2 (CP18%, no other supplement), G3 (CP16%, Symbiotic, 85 mg/L drinking water) and G4 (CP16%, Probiotic, 85 mg/L in drinking water). Fifteen birds were slaughtered at 5% of peak of production for each group to collect their pituitary glands. Better egg production was seen in all the supplemented groups as compared to the control. Especially an earlier post molt production recovery and delayed decline was seen in G2 as compared to all other groups. The immunohistochemistry of the pituitary gland reveals the decrease (P≤0.01) in the cell and nucleus size as well as area of somatotrophs in G2 and G4 as compared to G1. The cell and nucleus size as well as area of lactotrophs decreased (P≤0.01) in G2, G3 and G4 as compared to G1. The better and earlier post molt production in G2 highlights the potential role of protein supplementation in connection with the decreased lactotroph size and area in molted birds.Key words: immunohistochemistry, somatotroph, lactotroph, molting, protein, probiotic, layers.     

Detecting nonculturable bacteria in the active mycorrhizal zone of the pine mushroom <Emphasis Type="Italic">Tricholoma matsutake</Emphasis>

The fungus Tricholoma matsutake forms an ectomycorrhizal relationship with pine trees. Its sporocarps often develop in a circle, which is commonly known as a fairy ring. The fungus produces a solid, compact, white aggregate of mycelia and mycorrhizae beneath the fairy ring, which in Japanese is called a ’shiro’. In the present study, we used soil dilution plating and molecular techniques to analyze the bacterial communities within, beneath, and outside the T. matsutake fairy ring. Soil dilution plating confirmed previous reports that bacteria and actinomycetes are seldom present in the soil of the active mycorrhizal zone of the T. matsutake shiro. In addition, the results showed that the absence of bacteria was strongly correlated with the presence of T. matsutake mycorrhizae. The results demonstrate that bacteria, especially aerobic and heterotrophic forms, and actinomycetes, are strongly inhibited by T. matsutake. Indeed, neither bacteria nor actinomycetes were detected in 11.3% of 213 soil samples from the entire shiro area by culture-dependent methods. However, molecular techniques demonstrated that some bacteria, such as individual genera of Sphingomonas and Acidobacterium, were present in the active mycorrhizal zone, even though they were not detected in soil assays using the dilution plating technique.     

Plasma thyroxine and cortisol profiles and gill and kidney Na+/K+-ATPase and SDH activities during acclimation of the catfish Heteropneustes fossilis (bloch) to higher salinity, with special reference to the effects of exogenous cortisol on hypo-osmoregulatory ability of the catfish

When the stenohaline catfish Heteropneustes fossilis was transferred from fresh water (FW) to 30% seawater (SW), the Na(+)/K(+)-ATPase activity significantly increased in the kidney, while in gills it remained more or less constant. A reverse pattern was observed for succinic dehydrogenase (SDH) activity inasmuch as it significantly increased in gills and remained unchanged in the kidney. Plasma osmolality significantly increased within 3 days of transfer to 30% SW and remained significantly higher throughout the duration of experiment. These results suggest that catfish gills may not be able to reverse their function from salt uptake in FW to salt excretion at higher salinity, and that the elimination of monovalent as well as divalent ions is performed by the kidney but not the gills. The significant decline in plasma cortisol (F) levels following transfer to higher salinity may not be due to reduced production but rather to an enhanced utilization and clearance rate, a conclusion supported by the fact that exogenous administration of cortisol acetate (FA) resulted in significant increases in branchial and renal Na(+)/K(+)-ATPase in FW and 30% SW. FA also improved the plasma osmotic regulatory ability of the catfish, possibly due to a change in branchial function from salt-absorption to salt excretion, as was evident from a significant increase in branchial Na(+)/K(+)-ATPase activity in the fish in 30% SW pretreated with FA for 5 days. Consistently higher levels of plasma thyroxine (T4) following transfer to higher salinity suggest the involvement of this hormone at higher salinity.