Biomedical subjects

Manoj K Mishra

Publications and source records attributed to Manoj K Mishra.

5 recordsLinked to original sources

PubMed2006

Transcriptional downregulation of sterol metabolism genes in murine liver exposed to acute hypobaric hypoxia.

Ascent to high-altitude results in decreased inspired partial pressure of oxygen because of a decrease in barometric pressure. Altitude acclimatization requires physiological and metabolic changes to improve tolerance to altitude hypoxia. Cellular response to hypoxia results into changes in the profile of gene expression and the present study explored the same in murine model. Liver being the largest metabolic organ, the molecular details of acute hypobaric hypoxia (AHH) induced transcriptional changes in the tissue were investigated. Swiss albino mice were exposed to hypobaric hypoxia ( approximately 426mmHg) in a decompression chamber and cDNA microarray was used to study the transcriptional profile in liver. Notably, by the tenth hour several of the genes involved in sterol metabolism such as SREBF1, INSIG1, HMGCS1, FDFT1, SQLE, and HSD3B4 were downregulated more than 2-fold suggesting that AHH suppresses sterol biosynthesis in the liver. Real-time PCR helped validate the downregulation of SREBF1, HMGCS1, FDFT1, and HSD3B4 genes. However, no significant change was observed in the serum cholesterol levels throughout the AHH exposure. The findings are indicative of transcriptional downregulation of SREBP target genes as a part of acclimatization response to hypoxia. The study highlights the significance of SREBP in the regulation of sterol metabolism under the acute hypoxic response.

Adaptation, Physiological↗

PubMed2006

Electronic structure analysis and electron detachment energies of polynitrogen pentagonal aromatic anions.

Various decouplings of the electron propagator have been employed to provide theoretical comparison to experimental electron detachment energies for the pyrrolide, imidazolide, and pyrazolide anions. Predictions for isoelectronic anions in which CH groups are replaced by N atoms also are reported. The ab initio electron propagator results agree closely with experimental values, and the associated Dyson orbitals provide a detailed catalog of bonding changes as the number and positions of N atoms vary within the set of pentagonal aromatic anions.

Journal Article↗

PubMed2006

cDNA cloning, gene organization and variant specific expression of HIF-1 alpha in high altitude yak (Bos grunniens).

Hypoxia-inducible factor 1 (HIF-1) is a heterodimeric basic-helix-loop-helix-PER-ARNT-SIM (bHLH-PAS) transcription factor consisting of HIF-1alpha and HIF-1beta subunits. HIF-1alpha is the oxygen-regulated subunit of HIF-1, which regulates the transcription of genes involved in oxygen homeostasis in response to hypoxia. Yak (Bos grunniens), a mammal native to high altitude (HA) region ( approximately 3500-5500 m), has successfully adapted over many generations to the chronic hypoxia of HA. In the present work, cDNA encoding HIF-1alpha has been cloned from the blood of yak. Tissue specific expression of the mRNA was analyzed in blood, heart, lung, liver and kidney by RT-PCR with primers from three different regions of cDNA. The HIF-1alpha expression was liver and blood specific. The HIF-1alpha mRNA contains 823 bp long 3'UTR that is AU-rich and contains ten AUUUA pentamers and two overlapping copies of the nonamer UUAUUUAUUUAUU. Three potential microRNAs, hsa-miR-107/mmu-miR-107/rno-miR-107, hsa-miR-18b and hsa-miR-135a/mmu-miR-135a/rno-miR-135a, targeting 3'UTR of yak HIF-1alpha, were identified by using target prediction software. The CDS encodes for 823 residues of amino acids and showed 99%, 95%, 92%, 90% and 90% similarity to domestic cattle, human, plateau pika, mouse and rat HIF-1alpha, respectively. HIF-1alpha cDNA, cloned and sequenced in the present work has revealed the evolutionary conservation through multiple sequence alignment. Liver and blood specific stability of HIF-1alpha mRNA appears miR-107 regulated.

Altitude↗

PubMed2005

Spectral assignments for the aldose reductase inhibitor 4(S)-2,3-dihydro-6-fluoro-2(R)-methylspiro[chroman-4,4'-imidazoline]-2',5'-dione and its synthetic intermediates.

The 1H and 13C NMR chemical shifts of the aldose reductase inhibitor 4(S)-2,3-dihydro-6-fluoro-2(R)-methylspiro[chroman-4,4'-imidazoline]-2',5'-dione, methylsorbinil, and its seven synthetic intermediates, have been completely assigned on the basis of DEPT, COSY, g-HSQC and g-HMBC. All C--F coupling constants from one-bond to four-bond in the 13C NMR spectra and H--F and H--H coupling constants from three-bond to four-bond in 1H spectra were obtained.

Aldehyde Reductase↗

PubMed2004

Fock space multireference coupled cluster calculations based on an underlying bivariational self-consistent field on Auger and shape resonances.

The Fock space multireference coupled cluster based on an underlying bivariational self-consistent field is applied to the problem of computing complex energy associated with Auger and shape resonances in e-atom scattering. It is concluded that the Fock space multireference coupled cluster based on a bivariational self-consistent field provides a useful and practical approach to calculation of resonance parameters. Numerical results are presented for the 2P shape resonance of Mg and Auger 1 s(-1) hole of Be.

Journal Article↗