Preparation,Characterization, and Antimicrobial Activity of Chitosan/Kaolin Clay Biocomposite Films

Chitosan (CS) is a polycation found in nature that exhibits many good properties. Kaolin (KAO) clay is a natural inorganic filler and is being used in medicine, ceramic, food additives, etc. Therefore, the mixing of two such biomaterials, a natural polycation (CS) and natural filler (KAO clay) may lead to a biocomposite, chitosan/kaolin (CS/KAO) clay, with many interesting properties. In this study, the composites of CS and KAO clay are prepared by mixing the solution of CS (in dilute acetic acid) with KAO clay at various weight ratios. FT-IR, UV/Vis, X-Ray diffraction, SEM, UTM, TGA, and DSC analyses are used to investigate these biocomposites thoroughly. Agar well diffusion method has been used to determine the antibacterial activities of different concentrations of the CS- KAO clay against gram -positive (Bacillus subtilis) and gram- negative (Escherichia coli) bacteria. The biocomposites exhibited antibacterial activities against tested microrganisms. In addition, swelling tests of the biocomposites are also carried out. The CS/KAO clay biocomposite films show better tensile strength than CS film. It is observed that dispersed KAO clay improves the thermal stability and enhances the hardness of the matrix systematically with the increase of its loading.     

Contribution of the blood glucose level in perinatal asphyxia

This is a comparative study between 60 asphyxiated newborns (cases) and 60 normal neonates (controls) in respect of their plasma glucose and uric acid levels and also their clinical and neurological status. The mean plasma glucose level was significantly lower (35.1 ± 11.4 mg/dl vs. 56.9 ± 5.5 mg/dl; P < 0.001) and the mean serum uric acid level was higher (8.0 ± 1.2 mg/dl vs. 4.5 ± 0.83 mg/dl; P < 0.001) in the asphyxiated group when compared to the controls. Within the perinatal asphyxia group, the plasma glucose level and Apgar scores showed a significant positive linear correlation (r = 0.740, P < 0.001), whereas a significant negative linear correlation was observed between the glucose level and different stages of hypoxic ischemic encephalopathy (HIE) (r = −0.875, P < 0.001). Although a strong positive linear correlation was found between uric acid and HIE stages (r = 0.734, P ≤ 0.001), the linear correlation between uric acid and Apgar scores (r = −0.885, P < 0.001) and uric acid and the plasma glucose level (r = −0.725, P < 0.001) were found to be significantly negative among the cases. Conclusion: The severity of encephalopathy and cellular damage varies with the severity of hypoglycemia.     

Intestinal adherence of Vibrio cholerae involves a coordinated interaction between colonization factor GbpA and mucin

The chitin-binding protein GbpA of Vibrio cholerae has been recently described as a common adherence factor for chitin and intestinal surface. Using an isogenic in-frame gbpA deletion mutant, we first show that V. cholerae O1 El Tor interacts with mouse intestinal mucus quickly, using GbpA in a specific manner. The gbpA mutant strain showed a significant decrease in intestinal adherence, leading to less colonization and fluid accumulation in a mouse in vivo model. Purified recombinant GbpA (rGbpA) specifically bound to N-acetyl-D-glucosamine residues of intestinal mucin in a dose-dependent, saturable manner with a dissociation constant of 11.2 microM. Histopathology results from infected mouse intestine indicated that GbpA binding resulted in a time-dependent increase in mucus secretion. We found that rGbpA increased the production of intestinal secretory mucins (MUC2, MUC3, and MUC5AC) in HT-29 cells through upregulation of corresponding genes. The upregulation of MUC2 and MUC5AC genes was dependent on NF-kappaB nuclear translocation. Interestingly, mucin could also increase GbpA expression in V. cholerae in a dose-dependent manner. Thus, we propose that there is a coordinated interaction between GbpA and mucin to upregulate each other in a cooperative manner, leading to increased levels of expression of both of these interactive factors and ultimately allowing successful intestinal colonization and pathogenesis by V. cholerae.     

A comparative study on sublingual versus oral and vaginal administration of misoprostol for late first and early second trimester abortion

To compare the effectiveness, side-effects and outcome of sublingual with oral and vaginal administrations of misoprostol for induction of abortion in late first and early second trimester of gestation (9 to 16 weeks), a comparative observational study was carried out among 258 women with a period of gestation between 9 and 16 weeks, scheduled to have medical abortion, and randomly allocated into three groups and offered sublingual, oral and vaginal routes of misoprostol administration (400 mcg of misoprostol 6 hourly, maximum up to four dosages) respectively. Primary outcome measure was complete abortion rate and the secondary outcome measures were incidence of cases where surgical evacuation required, failure rate and induction-abortion interval. Development of side-effects and subjective assessment of patient's comfort with the different routes of administration were also recorded. Rate of complete abortion was higher in sublingual group in comparison to oral (p = 0.0338) and vaginal route (p = 0.5627). Surgical evacuation was required in less number of cases in sublingual group. Induction-abortion interval was also least with the sublingual route le, p < or = 0.0001 (versus oral) and 0.0011 (versus vaginal). Failure rate was highest with the oral route and least with the sublingual route. The patients were least comfortable with the vaginal route. Gastro-intestinal side-effects were least with the vaginal route, but significant vaginal bleeding (> 250 ml) was little bit higher with this route. Though misoprostol is effective in inducing medical abortion irrespective of the route of administration, sublingual route gives better results as compared to oral (statistically significant) and vaginal routes (in some respects, not of much statistical significance).     

Electrolyte status in birth asphyxia

Objective  

To study electrolyte status in asphyxiated newborns of different severity in early neonatal period and compare with controls.