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Biomedical subjects

R N Mishra

Publications and source records attributed to R N Mishra.

At least 19 recordsLinked to original sources
PubMed2006

Structural and functional analysis of a salt stress inducible gene encoding voltage dependent anion channel (VDAC) from pearl millet (Pennisetum glaucum).

We have cloned and characterized a gene encoding voltage-dependent anion channel from Pennisetum glaucum (PgVDAC). PgVDAC was identified while isolating genes that were differentially up-regulated following salt stress. The genomic organization of PgVDAC clone was well conserved compared to other plant VDAC genes in terms of number of introns, their position and phasing, however, the primary amino acid sequence of voltage dependent anion channel (VDAC) proteins did not show much conservation with other plant VDACs but their secondary and tertiary structures are well conserved as predicted by in silico structural and CD spectra analyses and results show it to be a typical membrane-spanning beta-barrel leading to the formation of pore in the membrane. The heterologous expression of PgVDAC protein in yeast strain lacking the endogenous mitochondrial VDAC gene could not functionally complement it as was also previously observed for the potato VDAC. Using real-time quantitative PCR analysis it was found that transcript expression profile of PgVDAC was quantitatively and kinetically up-regulated in response to salinity, desiccation, cold and exogenous application of salicylic acid (SA); however, there was no effect of exogenous application of abscisic acid (ABA) on its expression. Constitutive over-expression of PgVDAC appears to be deleterious in transgenic rice plant; however, low level of up-regulation imparted salinity stress adaptive response. A search for a more suitable inducible transgene system is currently under way to understand PgVDAC expression levels in plant development and its role in stress adaptation.

Amino Acid Sequence↗
PubMed2005

A modified cDNA subtraction to identify differentially expressed genes from plants with universal application to other eukaryotes.

We have designed a simple and efficient polymerase chain reaction (PCR)-based cDNA subtraction protocol for high-throughput cloning of differentially expressed genes from plants that can be applied to any experimental system and as an alternative to DNA chip technology. Sequence-independent PCR-amplifiable first-strand cDNA population was synthesized by priming oligo-dT primer with a defined 5' heel sequence and ligating another specified single-stranded oligonucleotide primer on the 3' ends of first-strand cDNAs by T4 RNA ligase. A biotin label was introduced into the sense strands of cDNA that must be subtracted by using 5' biotinylated forward primer during PCR amplification to immobilize the sense strand onto the streptavidin-linked paramagnetic beads. The unamplified first strand (antisense) of the interrogating cDNA population was hybridized with a large excess of amplified sense strands of control cDNA. We used magnetic bead technology for the efficient removal of common cDNA population after hybridization to reduce the complexity of the cDNA prior to PCR amplification for the enrichment and sequence abundance normalization of differentially expressed genes. Construction of a subtracted and normalized cDNA library efficiently eliminates common abundant cDNA messages and also increases the probability of identifying clones differentially expressed in low-abundance cDNA messages. We used this method to successfully isolate differentially expressed genes from Pennisetum seedlings in response to salinity stress. Sequence analysis of the selected clones showed homologies to genes that were reported previously and shown to be involved in plant stress adaptation.

Base Sequence↗
PubMed2004

A pea chloroplast translation elongation factor that is regulated by abiotic factors.

We report the cloning and characterization of both the cDNA (tufA) and genomic clones encoding for a chloroplast translation elongation factor (EF-Tu) from pea. The analysis of the deduced amino acids of the cDNA clone reveals the presence of putative transit peptide sequence and four GTP binding domains and two EF-Tu signature motifs in the mature polypeptide region. Using in vivo immunostaining followed by confocal microscopy pea EF-Tu was localized to chloroplast. The steady state transcript level of pea tufA was high in leaves and not detectable in roots. The expression of this gene is stimulated by light. The differential expression of this gene in response to various abiotic stresses showed that it is down-regulated in response to salinity and ABA and up-regulated in response to low temperature and salicylic acid treatment. These results indicate that regulation of pea tufA may have an important role in plant adaptation to environmental stresses.

Base Sequence↗
PubMed2004

Anatomical variations of the splenic artery and its clinical implications.

The variations in orgin, course, and terminal branching pattern of the splenic artery were studied in 320 cadavers. The artery originated from the coeliac trunk in the majority of cadavers (90.6%), followed by abdominal aorta (8.1%), and other sights (1.3%). A suprapancreatic course of the artery was commonly observed (74.1%) followed by enteropancreatic (18.5%), intrapancreatic (4.6%), and retropancreatic (2.8%) courses. In two cases (0.63%) the proximal part of the splenic artery made a loop that was embedded in the substance of the pancreas, which is an interesting and rare finding. In five cases (1.5%) the proximal part of the artery divided into two or more branches that had suprapancreatic and enteropancreatic courses. The splenic artery divided into terminal branches in 311 (97%) cadavers. In nine (2.8%) cadavers it passed through the hilum of spleen without dividing. Two terminal branches were the most common (63.1%) followed by four (18.8%), six (9.7%), and more than six (5.6%) branches. The present study clearly indicates that there is variation in origin, course, and terminal distribution pattern of the splenic artery. The knowledge of these variations are of significant importance during surgical and radiological procedure of upper abdominal region to avoid any catastrophic complications.

Aorta, Abdominal↗
PubMed2004

Comparative study of angiotensin converting enzyme inhibitor and calcium channel blocker in the treatment of steroid-resistant idiopathic nephrotic syndrome.

BACKGROUND: The aim of this study was to evaluate and compare the anti-proteinuric effect of ramipril and verapamil in patients with steroid-resistant idiopathic nephrotic syndrome. Twenty one (21) cases of steroid-resistant idiopathic nephrotic syndrome were randomized to receive ramipril (11) and verapamil (10) and were followed up for 12 months; monthly for the 1st 3 months and then every 3 months for the remaining study period. The degree of reduction of proteinuria, blood pressure, serum creatinine, serum albumin and side effects were noted between the two groups. The comparison within the groups over different time periods was made using paired 't' test and between the groups for specific time period by unpaired 't' test. The level of significance was taken as 5% or below. RESULTS: Seventeen patients (nine in the ramipril group and eight in the verapamil group) completed the study. The mean age of the patients, duration of illness, 24 hours urinary excretion of protein, mean arterial pressure, serum creatinine, cholesterol and albumin were similar in both the groups at time of randomization. The 24 hours urinary protein excretion decreased from 6319.44 +/- 1971.70 mg/day to 1852.44 +/- 1813.74 mg/day in patients receiving ramipril and from 5332.87 +/- 1947.47 mg /day to 2759.37 +/- 1929.6 mg/day in patients treated with verapamil after 12 months. There was no statistically significant difference in the reduction of proteinuria between the two groups. However, reduction in proteinuria was statistically significant from 2nd month onwards in Ramipril group and reduction was sustained throughout the study period. Reduction in mean arterial pressure was better achieved in Ramipril groups. The change in the serum potassium, creatinine, cholesterol and albumin were similar in either group of patients. Cough (2), hypotension (1) and reversible rise in serum creatinine (1) were observed with ramipril and no side effect was noted with verapamil. CONCLUSION: Both ramipril and verapamil can reduce proteinuria in patients suffering from steroid-resistant idiopathic nephrotic syndrome. However, ramipril had a better and sustained reduction in proteinuria with well-controlled mean arterial pressure. Verapamil can be considered as an alternative to ramipril when the use of the latter is not tolerated because of side effects and/or worsening of renal function in patients with chronic renal insufficiency.

Adolescent↗
PubMed2003

MRI features of tuberculosis of peripheral joints.

The aim of this article is to present the magnetic resonance imaging (MRI) features of peripheral tubercular arthritis. The clinical presentation of peripheral tubercular arthritis is variable and simulates other chronic inflammatory arthritic disorders. MRI is a highly sensitive technique which demonstrates fine anatomical details and identifies the early changes of arthritis, which are not visible on radiographs. The MRI features of tubercular arthritis include synovitis, effusion, central and peripheral erosions, active and chronic pannus, abscess, bone chips and hypo-intense synovium. These imaging features in an appropriate clinical setting may help in the diagnosis of tubercular arthritis. Early diagnosis and treatment can effectively eliminate the long-term morbidity of joints affected by tuberculosis.

Abscess↗
PubMed2002

Directional genome walking using PCR.

We describe here a PCR-based "directional genome walking" protocol. The basic procedure for the amplification consists of two rounds of PCR. A primary PCR was performed, on the genomic DNA using a biotinylated primer specific to a known sequence in the genome along with four universal walker primers that were designed with partial degeneracy. The biotinylated primary PCR products were immobilized on streptavidin-linked paramagnetic beads. This step removed all nonspecific amplification products, and the purified template was used for the second PCR using a nested primer and the walker primer-2 to increase specificity. This technique is potentially useful for cloning promoter regions and has been successfully used to isolate 5'-flanking genomic regions of many cDNA clones previously isolated by us.

Base Sequence↗
PubMed2000

Implementation of revised strategy of filaria control-baseline clinico-parasitological survey.

A clinico-epidemiological study of filariasis was carried out in Varanasi District in October and November, 1997 to generate baseline data for assessing the impact of Mass Drug Administration (MDA) in the district. Disease rate was found to be 6.6% (9.9% in males and 3.0% in females) and microfilaria rate was 5.3% (5.2% in males and 5.5% in females). Mean microfilaria density was found to be 9.86 per 20 Cu.mm blood. Genital manifestations (77.5%) outnumbered all other forms of clinical manifestations. Vector infectivity rate was found to be 0.93%.

Adolescent↗
PubMed1994

Alterations in histones of the liver and oviduct of Japanese quail during aging.

Age-related changes occur in histones of the liver and oviduct of the female quail. In the liver an extra histone band, named HCX, between H2A and H4, is observed that increases with age. In the oviduct, a large complex of histones is seen which is tissue-specific. This complex declines with increasing age. The changes in the histones of the oviduct of adult and old birds in response to estradiol and progesterone are age-related. In the adult, the histone-complex increases after administration of either one of the hormones. In old birds, however, it is seen only after progesterone administration. Thus, the alterations in histones in the birds are not only tissue- and age-related, but also vary in response to steroid hormones.

Aging↗
PubMed1993

Comparative outcome of low birth weight babies.

One hundred and fifty six babies with birth weight between 1500-2000 g and 103 full term-appropriate for gestational age (FT-AGA) babies delivered at University Hospital, District Hospital and village homes were included for a comparative study of mortality, morbidity and growth pattern. The low birth weight (LBW) babies from the three centres had similar birth weight and gestational age. Neonatal mortality rates for the LBW babies were similar at the three centres. The main cause of death were infections and aspiration with rates again being similar. Diarrhea and respiratory tract infections were common causes of morbidity. The mortality rates for the LBW babies were significantly higher as compared to FT-AGA babies irrespective of the place of delivery. The incidence of morbidities like diarrhea and respiratory infections were also higher in LBW babies. However, the differences were statistically significant mostly in the preterm group. The weight gain of all LBW babies was similar up to 3 months of age. The findings of an identical outcome for the LBW babies at village level to those managed at hospitals is an encouraging trend to increasing domiciliary care for LBW babies.

Fetal Growth Retardation↗
PubMed1991

Development of Leishmania donovani in Phlebotomus argentipes & Ph. papatasi fed on kala-azar patients in Bihar.

A total of 258 laboratory bred Ph. argentipes was fed on untreated parasitologically confirmed kala-azar patients. Successful development of parasites was noted in 0.54 per cent Ph. argentipes fed during the day and 5.33 per cent fed during the night. However, none of the 245 laboratory bred Ph. papatasi fed on the same patients, was found positive for successful development of L. donovani in the foregut.

Animals↗
PubMed1986

On a probability distribution to study the open birth interval and its application.

"A probability distribution for describing the variation in the length of open birth interval regardless of parity has been derived assuming that fecundability varies from female to female and the births are of two types, one which results [in] infant death and the other [which does] not. To get the estimates of the parameters, expressions for the first two moments have been derived. The model has been applied to the data taken from the survey 'Rural Development and Population Growth--A Sample Survey 1978,' conducted under the auspices of the Demographic Research Centre, Banaras Hindu University [India]."

Asia↗