Sucrose Octaacetate Chemical Kinetics and Shelf Lives at Various Formulation pHs

Developing pediatric friendly dosage forms is a high priority worldwide. Sucrose octaacetate (SOA) has been recommended for use as a surrogate for bitter tasting active pharmaceutical ingredients. Even though SOA has found a number of human use applications and has been employed for decades, there are no rigorous chemical kinetic studies reported. A recently reported SOA stability-indicating method was used to perform SOA chemical kinetic and stability studies. As part of the chemical kinetic study, reaction order, activation energies, extrapolated rate constants, pH–rate profiles at 4 and 25°C, and estimated shelf lives at 4 and 25°C at different buffer pHs are provided. The estimated SOA shelf lives at 25°C and pHs 4.00, 5.20, and 6.00 were 25.3, 114, and 27.4 days, respectively. At 4°C, SOA’s estimated shelf lives were 0.478, 5.26, and 1.47 years at pHs 4.00, 5.20, and 6.00, respectively. SOA can be formulated at pHs 4 to 6 and stored at 25°C for short-duration (less than 25 days) uses such as a bitter tasting surrogate for fundamental taste mechanism studies or brief taste masking assessment clinical studies. For longer term solution studies, like being used as a bitter tasting control for blinded clinical trials, SOA should be formulated at the optimum pH of 5.40 and refrigerated at 4°C for maximum stability. The reported data can be used as a starting point for developing stable SOA formulations and estimating shelf life.     

Structural and Functional Properties of Exopolysaccharide Excreted by a Novel <Emphasis Type="Italic">Bacillus anthracis</Emphasis> (Strain PFAB2) of Hot Spring Origin

Exopolysaccharide produced by a unique avirulent Bacillus anthracis strain PFAB2 of hot spring origin has been characterized and its functional properties are investigated which is a first report. Maximum yield of EPS is 7.66 g/l with 2% glucose and 1% peptone as optimum carbon and nitrogen source respectively. The EPS is found to be a homopolymer consisting of only glucose as principle monosaccharide component. Through ¹H NMR study, different dextran-like proton peaks are observed. Molecular weight of the EPS resembles low molecular weight bacterial origin polysaccharides. Melting transition of the EPS has started after 276 °C which indicates good thermal stability. The EPS also shows potent antioxidant activity in terms of DPPH and ABTS mediated free radical scavenging property compared to standard ascorbic acid. Emulsifying property of the EPS is also observed and has shown good emulsification of vegetable oils. The polysaccharide forms a thermo resistant gel during the heating phase, with G′ higher than G″ indicating excellent shear-thinning behaviour and viscoelastic nature of the EPS.     

Monoallelic and Biallelic Variants in EMC1 Identified in Individuals with Global Developmental Delay,Hypotonia, Scoliosis,and Cerebellar Atrophy

The paradigm of a single gene associated with one specific phenotype and mode of inheritance has been repeatedly challenged. Genotype-phenotype correlations can often be traced to different mutation types, localization of the variants in distinct protein domains, or the trigger of or escape from nonsense-mediated decay. Using whole-exome sequencing, we identified homozygous variants in EMC1 that segregated with a phenotype of developmental delay, hypotonia, scoliosis, and cerebellar atrophy in three families. In addition, a de novo heterozygous EMC1 variant was seen in an individual with a similar clinical and MRI imaging phenotype. EMC1 encodes a member of the endoplasmic reticulum (ER)-membrane protein complex (EMC), an evolutionarily conserved complex that has been proposed to have multiple roles in ER-associated degradation, ER-mitochondria tethering, and proper assembly of multi-pass transmembrane proteins. Perturbations of protein folding and organelle crosstalk have been implicated in neurodegenerative processes including cerebellar atrophy. We propose EMC1 as a gene in which either biallelic or monoallelic variants might lead to a syndrome including intellectual disability and preferential degeneration of the cerebellum.     

Effect of chronic pesticide exposure on murine cornea: a histopathological,cytological and flow cytometric approach to study ocular damage by xenobiotics

Pesticide exposure can occur directly or indirectly in an occupational setting or otherwise. The health hazards of pesticides have long been studied; however, little is known about the ocular insult of these potent chemicals. In this study, we examined the consequences of long-term pesticide exposure on the ocular tissue in animal model with special focus on the cornea. Swiss Albino mice were sacrificed to obtain the eye globes and various cytological, cytotoxic and histological evaluations, in vitro growth kinetic studies and flow cytometric analyses of select cytokeratins were performed to determine the structural and functional damage due to pesticide exposure. Our study revealed the detrimental impact of this xenobiotic insult by cataloguing the damage to each layer of the cornea wherein it was discovered that all the functional layers as well as the membranes were compromised. We hope that our investigation will pave the way for future studies in this oft overlooked area of affront caused by pesticide exposure to the ocular surface.     

An ANN model for the identification of deleterious nsSNPs in tumor suppressor genes

Human genetic variations primarily result from single nucleotide polymorphisms (SNPs) that occurs approximately every 1000 bases in the overall human population. The non-synonymous SNPs (nsSNPs), lead to amino acid changes in the protein product may account for nearly half of the known genetic variations linked to inherited human diseases and cancer. One of the main problems of medical genetics today is to identify nsSNPs that underlie disease-related phenotypes in humans. An attempt was made to develop a new approach to predict such nsSNPs. This would enhance our understanding of genetic diseases and helps to predict the disease. We detect nsSNPs and all possible and reliable alleles by ANN, a soft computing model using potential SNP information. Reliable nsSNPs are identified, based on the reconstructed alleles and on sequence redundancy. The model gives good results with mean specificity (95.85&), sensitivity (97.40&) and accuracy (96.25&). Our results indicate that ANNs can serve as a useful method to analyze quantitative effect of nsSNPs on protein function and would be useful for large-scale analysis of genomic nsSNP data. AVAILABILITY: The database is available for free at http://www.snp.mirworks.in.     

Cellular evidence of allelopathic interference of benzoic acid to mustard (Brassica juncea L.) seedling growth.

Cellular changes in the roots of mustard (Brassica juncea L.) grown in soil treated with 1.09, 1.46 and 1.83 mg benzoic acid per g soil, a known allelochemical, were analyzed after 7 days. The recoverable concentration of 1.09, 1.46 and 1.8 mg benzoic acid per g soil (measured by high performance liquid chromatography) was 68, 150 and 250 microg benzoic acid per g soil, respectively. The benzoic acid treatments suppressed root growth by 30.5%, 58.8% and 81.1% with increasing concentrations. Transmission electron microscopy studies of roots showed irregular shaped cells arranged in disorganized manner and disruption of cell organelles at cellular level. Root cells showed dissolution of middle lamella (at 68 and 150 microg benzoic acid per g soil) but intact middle lamella with increased wall deposits was observed with 250 microg benzoic acid per g soil. Damage to the mustard root at cellular level was evidenced by changes in cell morphology and internal organization.     

Opportunistic Infections among People Living with HIV (PLHIV) with Diabetes Mellitus (DM) Attending a Tertiary Care Hospital in Coastal City of South India

Background

HIV/AIDS and Diabetes Mellitus are the diseases’ known to supress cell mediated immunity and predispose patients for opportunistic infections. Hence, we conducted a study to compare the common opportunistic infections (OIs) between People Living with HIV with DM (PLHIV-DM) and PLHIV without DM (PLHIV).

Methodology

PLHIV with DM and without DM (1:1) were prospectively included in the study from January 2011 to January 2012 at a tertiary care hospital in Mangalore city. Patients were classified as Diabetic if their fasting plasma glucose was ≥ 7.0mmol/l (126mg/dl) or 2–h plasma glucose was ≥11.1mmol/l (200mg/dl). Standard procedures and techniques were followed for diagnosis of OIs as per WHO guidelines. The data was entered and analyzed using Statistical Package for Social Sciences (SPSS) version 11.5.

Findings

The study included 37 PLHIV with DM and 37 PLHIV without DM and both groups were treated with Anti-Retroviral Therapy (ART). The median age was 47 years (IQR: 41-55years) for PLHIV-DM as compared to 40 years (IQR: 35–45.5 years) for PLHIV (p<0.0001). PLHIV-DM had median CD4 counts of 245 (IQR: 148–348) cells/μl compared to 150(IQR: 70–278) cells/μl for PLHIV (p = 0.02). Common OIs included oral candidiasis (49% of PLHIV-DM and 35% of PLHIV); Cryptococcal meningitis (19% of PLHIV-DM and 16% of PLHIV); Pneumocystis jiroveci pneumonia (5% of PLHIV-DM and 18% of PLHIV); extra pulmonary tuberculosis (22% of PLHIV-DM and 34.5% of PLHIV); and Cerebral toxoplasmosis (11% of PLHIV–DM and 13.5% of PLHIV). Microbiological testing of samples from PLHIV- DM, C krusei was the most common Candida species isolated from 9 out of 18 samples. Out of six pulmonary TB samples cultured, four grew Non-tuberculosis mycobacteria (NTM) and two Mycobacterium tuberculosis complexes.

Conclusions

Study did not identify any significant difference in profile of opportunistic infections (OIs) between PLHIV with and without Diabetes.     

Some mechanistic aspects on chiral discrimination of organic acids by immobilized bovine serum albumin (BSA)

Although chiral anionic compounds, notably a large number of organic acids, have been found to be readily separated into enantiomers on BSA-based columns, the structural requirements for an efficient enantiomer discrimination by the protein is still not very well known. Since it is often observed that very hydrophobic acids, like many of the antiinflammatory “profens,” can be resolved with large separation factors for the enantiomers, a systematic study of a series of racemic α-substituted alkanoic acids was made. The series of analytes was prepared from α-amino acids, RCH(NH₂)CO₂H (where R = C₁-C₆), by reaction with N-(chloroformyl)-carbazole. A rapid increase in the capacity ratios of both enantiomers was found with increasing length of R. The effect, however, was larger for the last eluted enantiomer, leading to a substantial increase in the separation factor; this being 7.3 for R = C₆ in 20 mM phosphate buffer (pH 8.0) with 30% of acetonitrile. Further, the separation factor also increased with decreasing organic modifier content. Thus when the R = C₆-analyte was run at a mobile phase concentration of 20% acetonitrile and a flow rate of 1.5 ml/min, the time difference between the two eluted enantiomers exceeded 20 hr. A reasonable interpretation of our results seems to be that enantioselectivity is promoted by increased hydrophobic interaction. Since the anionic charge of the analyte is also taking part in the retention mechanism, a tight binding of the analyte will result from simultaneous electrostatic and hydrophobic interaction. When the latter is increased, less conformational freedom will be left for the analyte and the steric configuration at the α-carbon atom will become more and more important. Steric hindrance by the α-substituent in the first eluted enantiomer will counteract the tight binding caused by the combined binding interactions and lead to a smaller increase in the capacity ratio.