Single nucleotide polymorphisms in alcohol dehydrogenase genes among some Indian populations.

Seven ADH genes, identified until now, located in the long arm of human chromosome 4, produce seven different isozymes involved in the metabolism of ethanol to acetaldehyde. Of the more than 500 SNPs reported in the coding and non-coding regions of these genes in the world databases, 11 are more extensively studied. Three SNPs, ADH1B Arg47His (Exon3), ADH1B Arg369Cys (Exon9) and ADH1C Val349Ile (Exon8), are functionally validated in terms of phenotype-genotype correlations and are in specific linkage disequilibrium (LD) with non-coding SNPs. However, the frequency of each SNP and configuration of LD varies among populations. The Indian populations studied were conspicuous by the complete absence of African specific allele ADH1B*369Cys, the negligible frequency of East Asian specific ADH1B*47His allele and the presence of a novel SNP ADH1B A3529G (Intron3). The ADH1C*349Ile was the only functional allele polymorphic with a strong LD block in all the populations studied and the high F(st) value observed for the non-coding ADH1B Rsa1 variant was in conformity with world populations.     

Loss of base excision repair in aging rat neurons and its restoration by DNA polymerase beta

Synthetic staggered oligodeoxynucleotide duplexes are formed by annealing a 5'-32P-labeled 14-mer with four different 21-mers. These duplexes have either a correct or mismatched base pair at 3'-end of the primer. With these model template primers the ability of neuronal extracts, obtained from rats of different ages, to extend the primer to the predicted length was tested. While the neuronal extracts of all ages were able to degrade the 14-mer to shorter lengths, extension of the primers in general and in particular, the mismatched, is achieved only feebly by the young and adult neuronal extracts and undetectable with old neuronal extracts. The possibility of restoring the lost activity by supplementing the neuronal extracts with pure DNA polymerases was examined. Of the three polymerases tested (calf thymus alpha polymerase, E. coli DNA polymerase I and rat liver DNA polymerase beta) only polymerase beta gave consistent and encouraging results although the extension was slow and distributive in nature and mismatched primers were extended much less efficiently than the correctly paired primer. However, significantly improved extension, including those of mismatched primers, was achieved by prior removal of mismatched bases in a preincubation with just the neuronal extracts (3'-5'exonuclease activity) followed by extension by the added polymerase beta and dNTPs in the presence of Mn(2+) instead of the usual Mg(2+). These results are taken to indicate that the activity of polymerase beta in brain cells is compromised with age and that this deficit can be corrected in vitro by the addition of pure recombinant rat liver polymerase beta under appropriate conditions.     

Hippocampal asymmetry and sudden unexpected death in infancy: a case report

The differential diagnosis of known entities associated with sudden unexpected death in infancy is ever expanding. Here we report the case of a 10-month-old infant boy whose clinical presentation mimicked that of the sudden infant death syndrome (SIDS). This presentation included the typical features of SIDS: sleep-related death; prone position upon discovery; and minor illness within 2?days of death. Nevertheless, neuropathologic examination revealed striking hippocampal asymmetry and microdysgenesis similar to that reported previously by us in toddlers with sleep-related sudden death. Hippocampal maldevelopment in the setting of sudden death in infants and toddlers is analogous to sudden unexpected death in epilepsy associated with temporal lobe pathology, and suggests a possible role for seizures in the terminal events leading to sudden death. This report serves to alert pediatric and forensic pathologists to hippocampal asymmetry and microdysgenesis in the differential diagnosis of sudden infant death mimicking SIDS.     

Therapeutic potential of sulindac against ischemia-reperfusion-induced myocardial infarction in diabetic and nondiabetic rats

BACKGROUND

Diabetes mellitus is an independent risk factor for cardiovascular disease and is also associated with increased susceptibility to cardiovascular complications. It has been suggested that alterations in glucose metabolism and glucose flux via the aldose reductase pathway make the diabetic heart more sensitive to ischemic-reperfusion injury. Previous studies have found sulindac to have inhibitory and anti-inflammatory effects on aldose reductase. The use of aldose reductase inhibitors for the protection of ischemic myocardium is still in an exploratory state.

OBJECTIVES

To evaluate the therapeutic potential of sulindac in an in vivo rat model of acute ischemia (30 min) and reperfusion (4 h) in diabetic and nondiabetic rats.

METHODS

Diabetes was induced in rats by administering streptozotocin (45 mg/kg, intravenously). Myocardial infarction was induced by occlusion of the left anterior descending coronary artery for 30 min followed by 4 h of reperfusion. Infarct size was measured using the staining agent 2,3,5-triphenyltetrazolium chloride. A lead II electrocardiogram was monitored at various intervals throughout the experiment. Sorbitol dehydrogenase levels in heart tissue, as well as lipid peroxide levels in serum and heart tissue, were estimated spectrophotometrically.

RESULTS

Infarct size was increased in diabetic rats in comparison with normal rats. Pretreatment with sulindac significantly reduced infarct size, lipid peroxidation and sorbitol dehydrogenase levels in both diabetic and nondiabetic rats. The degree of cardioprotection was greater in diabetic rats than in nondiabetic rats.

CONCLUSIONS

The present study indicates that the observed cardioprotection provided by sulindac in terms of reducing infarct size in normal rats may be due to its combined antioxidant and anti-inflammatory activities. The inhibition of aldose reductase may be responsible for the enhanced cardioprotection observed in diabetic rats treated with sulindac.     

Bedaquiline has potential for targeting tuberculosis reservoirs in the central nervous system

Bedaquiline (BDQ) is the first-in-class United States Food and Drug Administration (US FDA) approved anti-tuberculosis (anti-TB) drug, which is a novel diarylquinoline antibiotic that has recently been utilized as an effective adjunct to existing therapies for multidrug-resistant tuberculosis (MDR-TB). BDQ is especially promising due to its novel mechanism of action, activity against drug-sensitive and drug-resistant tuberculosis (TB) in addition to having the potential to shorten treatment duration. Drug delivery to the central nervous system (CNS) is a major concern in TB chemotherapy, especially with the increasing cases of CNS-TB. In this study, we investigated the CNS penetration of BDQ in healthy rodent brain. Male Sprague-Dawley rats (n = 27; 100 ± 20 g) received a single 25 mg kg⁻¹ b.w dose of BDQ via intraperitoneal (i.p.) administration, over a 24 h period. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to determine whole tissue drug concentrations and matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) was utilized to evaluate drug distribution in the brain. BDQ reached peak concentrations (C_max) of 134.97 ng mL⁻¹ in the brain at a T_max of 4 h, which is within the range required for therapeutic efficacy. BDQ was widely distributed in the brain, with a particularly high intensity in the corpus callosum and associated subcortical white matter including the striatal, globus pallidus, corticofugal pathways, ventricular system, basal forebrain region and hippocampal regions. Using MALDI MSI, this study demonstrates that due to BDQ''s distribution in the brain, it has the potential to target TB reservoirs within this organ.

Bedaquiline (BDQ) was administered to healthy Sprague-Dawley rats in order to determine its localisation in the brain using mass spectrometry imaging (MSI). This study shows that BDQ has the potential for targeting TB reservoirs in the CNS.     

Structural elucidation of NASICON (Na3Al2P3O12) based glass electrolyte materials: effective influence of boron and gallium

Understanding the conductivity variations induced by compositional changes in sodium super ionic conducting (NASICON) glass materials is highly relevant for applications such as solid electrolytes for sodium (Na) ion batteries. In the research reported in this paper, NASICON-based NCAP glass (Na_2.8Ca_0.1Al₂P₃O₁₂) was selected as the parent glass. The present study demonstrates the changes in the Na⁺ ion conductivity of NCAP bulk glass with the substitution of boron (NCABP: Na_2.8Ca_0.1Al₂B_0.5P_2.7O₁₂) and gallium (NCAGP: Na_2.8Ca_0.1Al₂Ga_0.5P_2.7O₁₂) for phosphorus and the resulting structural variations found in the glass network. For a detailed structural analysis of NCAP, NCABP and NCAGP glasses, micro-Raman and magic angle spinning-nuclear magnetic resonance (MAS-NMR) spectroscopic techniques (for ³¹P, ²⁷Al, ²³Na, ¹¹B and ⁷¹Ga nuclei) were used. The Raman spectrum revealed that the NCAP glass structure is more analogous to the AlPO₄ mesoporous glass structure. The ³¹P MAS-NMR spectrum illustrated that the NCAP glass structure consists of a high concentration of Q⁰ (3Al) units, followed by Q⁰ (2Al) units. The ²⁷Al MAS-NMR spectrum indicates that alumina exists at five different sites, which include AlO₄ units surrounded by AlO₆ units, Al(OP)₄, Al(OP)₅, Al(OAl)₆ and Al(OP)₆, in the NCAP glass structure. The ³¹P, ²⁷Al and ¹¹B MAS-NMR spectra of the NCABP glass revealed the absence of B–O–Al linkages and the presence of B₃–O–B₄–O–P₄ linkages which further leads to the formation of borate and borophosphate domains. The ⁷¹Ga MAS-NMR spectrum suggests that gallium cations in the NCAGP glass compete with the alumina cations and occupy four (GaO₄), five (GaO₅) and six (GaO₆) coordinated sites. The Raman spectrum of NCAGP glass indicates that sodium cations have also been substituted by gallium cations in the NCAP glass structure. From impedance analysis, the dc conductivity of the NCAP glass (∼3.13 × 10⁻⁸ S cm⁻¹) is slightly decreased with the substitution of gallium (∼2.27 × 10⁻⁸ S cm⁻¹) but considerably decreased with the substitution of boron (∼1.46 × 10⁻⁸ S cm⁻¹). The variation in the conductivity values are described based on the structural changes of NCAP glass with the substitution of gallium and boron.

Understanding the conductivity variations induced by compositional changes in sodium super ionic conducting (NASICON) glass materials is highly relevant for applications such as solid electrolytes for sodium (Na) ion batteries.     

Lower Frequency and Diversity of Antibiotic-Producing Fluorescent Pseudomonads in Rhizosphere of Indian Rapeseed–Mustard (<Emphasis Type="Italic">Brassica juncea</Emphasis> L. Czern.)

Fluorescent pseudomonads are one of the most important microbial communities which play a key role in rhizosphere to enhance plant growth-promotion and protection. The diverse groups of antibiotics viz. 2,4-diacetylphloroglucinol (DAPG), phenazine-1-carboxylic acid (PCA) and pyoluteorin (PLT) are produced by fluorescent pseudomonads inhibiting growth of fungal pathogens which results in health upliftment of plants. The present study, discusses about frequency and diversity of 138 antibiotic-producing fluorescent pseudomonads isolated from eight genotypes of rapeseed mustard rhizosphere (Brassica juncea L. Czern.). The plant growth promoting traits and antibiotics (DAPG, PCA and PLT) production of isolates were examined by using polymerase chain reaction (PCR), thin layer chromatography (TLC) and dot blot-hybridization. Among 138 isolates, 47, 25 and 9 % of isolates were positive in indole production, phosphate solubilization and antagonism potential against Sclerotinia sclerotiorum (causal agent of white mold disease in rapeseed mustard), respectively. PCR amplifications showed that none of the isolates had phlD (DAPG) and phzC (PCA) genes, but four isolates (UKA-2, UKA-8, UKA-11, UKA-66) had pltB (PLT) gene, which was further confirmed by TLC and DNA dot-blot hybridization. BOX profiles of pltB positive isolates were distinct, showing unique genetic diversity in the small population. The four pltB positive fluorescent pseudomonad isolates could be used as promising bio-control and plant growth-promoting inoculants for Indian rapeseed mustard.