Antibodies to group A streptococcal virulence factors, SIC and DRS, increase predilection to GAS pyoderma

Background: Streptococcus pyogenes (group A streptococcus; GAS) is an etiological agent for pharyngitis, pyoderma, and invasive infections in humans. Pharyngitis and pyoderma may lead to serious immune sequelae such as rheumatic heart disease and post-streptococcal glomerulonephritis (PSGN). Streptococcal Inhibitor of Complement (SIC) and its orthologue, distantly related to SIC (DRS), are virulence factors expressed by only four of more than 100 M types of GAS. These four types (M1, M57, M12 and M55) are among the M types, which are associated with PSGN. In several populations PSGN has been shown to be a risk factor for chronic kidney disease (CKD) and end-stage renal disease (ESRD). Previous studies showed SIC or DRS antibody-prevalence was associated with PSGN, and seroprevalence of SIC antibodies is significantly high among CKD and ESRD patients in Mumbai. Methods: Streptococcal isolates recovered from GAS pyoderma cases were typed. Seropositivity for SIC and DRS antibodies in subjects with pyoderma, PSGN pediatric cases, age matched healthy controls and non-GAS pyoderma cases were determined. Results: We confirm in this study an association between seroprevalence to SIC and DRS antibodies, and PSGN in Mumbai population despite low point prevalence of M1, M12, M55 and M57. In addition we extended the study to GAS-pyoderma and non-GAS pyoderma cases. To our surprise, we found a positive association between the seroprevalence to SIC and DRS antibodies, and GAS-pyoderma owing to infection with diverse M types. The mechanism of increased predisposition to pyoderma owing to infection by diverse GAS among SIC or DRS antibody-positive population is not clear. Nonetheless, our findings could be explained by a phenomenon akin to antibody-dependent enhancement (ADE). Conclusions: This is the first report showing a small number of GAS M types conferring predisposition to pyoderma by diverse types. Implications of this ADE-like phenomenon are discussed in the light of evolutionary advantage to GAS, vaccine design and control of renal diseases.Full Tex

A Method for the Quantification of Nanoparticle Dispersion in Nanocomposites Based on Fractal Dimension

Dispersion quantification provides critical insight and towards understanding and improving the influence of nanoparticle dispersion on the behaviour of the nanocomposite at macro and nanoscale level. This study was precipitated by the limitations of most methods for quantifying dispersion to sufficiently handle issues regarding scalability, complexity, consistency and versatility. A quantity (D 0 ) based on the variance of the fractal dimension was used to quantify dispersion successfully. The concept was validated using real microscopy images. The approach is simple and versatile to implement

ANALYSIS OF DYNAMIC CHARACTERISTICS OF SHORT JOURNAL BEARINGS -A REVIEW

he stability of bearing-rotor system is a very important problem for design, manufacturing, and operation of rotating machinery. The instability of rotor system will result in the strong vibration and even disastrous accident of machinery. The researches for decades indicate that the strong-nonlinear exciting sources such as oil-film forces, sealing forces and non uniform steam forces etc. all are main reasons which can make unstable accidents in rotating machineries. The oil-film forces are the leading nonlinear exciting source which makes the bearing rotor system to be a self-exciting vibration system and results in fatal accidents. So solution of nonlinear oil-film forces in sliding bearings is always very important for dynamic analysis of rotor-bearing system

PC-Polyolefins: Synthesis and Assembly Behavior in Water

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An evaluation of the antidiabetic effects of Elaeocarpus ganitrus in experimental animals

Objective : To evaluate the antidiabetic effects of the aqueous extract of Elaeocarpus ganitrus (EAG) in experimental animals. Materials and Methods : The hypoglycemic activity of the EGA was evaluated in normoglycemic rats by single dose at three graded dose levels, viz. 250, 500 and 1000 mg/kg of body weight. Antihyperglycemic activity of the extract was also evaluated at the same dose levels in streptozotocin (STZ) (60 mg/kg, i.p.)-induced diabetic rats during a 30-day treatment period. Metformin (500 mg/kg) was used as the reference drug. Fasting blood glucose and lipid parameters, viz. triglycerides, total cholesterol, high-density lipoprotein and low-density lipoprotein levels were measured. Acute oral toxicity of the EGA extract was carried out in Swiss albino mice. Results : In normoglycemic rats, EGA showed a significant (P < 0.01) hypoglycemic effect at 2 h. In STZ-induced diabetic rats, the EGA treatment significantly (P < 0.05) decreased the blood glucose level in a dose-dependent manner during the 30 days of treatment period. EGA modulated lipid profile changes in STZ-diabetic rats in a dose-dependant manner. In the acute oral toxicity study, EGA showed no mortality till the 5 g/kg dose in mice. Conclusion : The present investigation shows that EAG seeds has potential antidiabetic effects