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Biomedical subjects

G P Singh

Publications and source records attributed to G P Singh.

At least 19 recordsLinked to original sources
PubMed2025

Development and validation of a high-density 'Amahysnp' genotyping array in grain amaranth (Amaranthus hypochondriacus).

BACKGROUND: Grain amaranth has recently gained global attention as a promising crop alternative to traditional cereals due to its nutritional value and adaptability to various growing conditions. Although gene banks conserve extensive collections of amaranth germplasm, the genomic and phenotypic characterization of these resources is limited, which hinders their full utilization in breeding programs. A major challenge is the lack of high-throughput genotyping assays essential for comprehensive genomic characterization and trait mapping. High-density SNP arrays have become standard tools for genome-wide analysis across multiple loci, enabling molecular breeding across a range of crop species. RESULTS: In this study, we developed a 64 K high-throughput SNP genotyping array named "AmahySNP", using Affymetrix® Axiom® technology. The array contains 64,069 high-density SNPs distributed across both genic (55.17%) and non-genic (44.83%) regions of the Amaranthus hypochondriacus genome. The genic region includes 8,879 genes, which consist of 4,830 single-copy genes and 4,049 multi-copy genes distributed across 16 scaffolds. These genes cover various functional regions, including exons (10.5%), introns (40.1%), 5'UTRs (1.6%), and 3'UTRs (2.9%), respectively. The AmahySNP array was effectively utilized for population structure analysis, genetic diversity studies, core development, and genome wide association studies (GWAS) in amaranth germplasm. A representative core set of 112 accessions was identified, which includes two released varieties (Annapurna and Suvarna) and 100 diverse accessions from 12 different regions, representing 12% of the total 917 accessions evaluated. Phylogenetic analysis revealed three major genetic clusters, independent of their geographical origins. GWAS conducted using 22,763 polymorphic SNPs from 540 genotypes identified 13 novel loci associated days to flowering (DTF) trait, seven of which were located within annotated genes. CONCLUSIONS: The AmahySNP 64 K SNP chip a valuable genomic tool for amaranth research and breeding with a strong potential to accelerate its genetic improvement. It enables high-throughput genotyping for a wide range of applications, including GWAS and other genomic studies, and will significantly advance the exploration of natural genetic variations. Ultimately, this resource will empower amaranth breeders to develop improved amaranth cultivars with enhanced crop yield, resilience, and nutritional quality, contributing to global food security and sustainable agriculture.

Amaranthus↗
PubMed2006

Efficacy of caudal butorphanol.

OBJECTIVE: To evaluate the efficacy of butorphanol with or without bupivacaine for caudal epidural anesthesia in children undergoing infraumbilical surgery. METHODS: Sixty ASA physical status I and II patients of either sex aged 1-10 yr were randomized to one of three groups. Group L received 1 ml/kg of 0.25% bupivacaine; Group B received 1 ml/kg of 25 microg/kg butorphanol diluted in normal saline; and Group LB received 1 ml/kg of 25 microg/kg butorphanol in combination with 0.25% bupivacaine, in caudal epidural anesthesia. Hemodynamic variables (HR and MAP) and respiratory rate were monitored in all patients. Sedation score, pain score and requirement of rescue analgesia were recorded at preset time intervals alongwith post-operative complications. RESULTS: There was no difference among the groups regarding sedation scores, requirement of rescue analgesia and post-operative complications. Mean duration of analgesia was maximum in group BL (14.5 +/- 3.5 hr, P<0.001), than in group L (8.8 +/- 4.8 hr) and group B (6.8 +/- 2.9 hr). CONCLUSION: The addition of 25 microg/kg butorphanol to bupivacaine resulted in superior analgesia with a longer period compared with caudal bupivacaine and butorphanol alone, without an increase of side effects.

Analgesics, Opioid↗
PubMed2006

Plasma tocopherol levels: a preliminary reference range.

Alpha-tocopherol level was measured spectrofluorometrically in 279 healthy volunteers to establish reliable reference values and to compare possible sex and age-related differences. In the present study, men had higher tocopherol levels than women (p<0.05) and older subjects had lower values. This study provides reference values for alpha-tocopherol that may assist it evaluating the anti-oxidant defense.

Adult↗
PubMed2005

Oral midazolam and oral butorphanol premedication.

OBJECTIVE: To evaluate the efficacy of oral midazolam and oral butorphanol for their sedative analgesic effects in children. METHODS: Sixty children, aged 2 to 10 yrs, of ASA physical status I and II, scheduled for surgical procedures of 1 to 2 hrs duration were randomized to one of the two groups. Group I: children received midazolam 0.5 mg/kg orally and Group II: children received butorphanol 0.2 mg/kg orally. Score of the children was assessed every 5 minutes till the induction of anesthesia. Intraoperative and postoperative analgesic requirement was recorded along with postoperative recovery and complications. RESULTS: The groups were identical regarding the patient's characteristics, hemodynamic variables, duration of surgery and awakening time. Less time was required for the onset and time of maximum sedation in the butorphanol group (p<0.05). Sedation scores were similar among the groups at all time intervals, while the scores were higher in the butorphanol group at the time of induction (p<0.05). Less number of children required intraoperative and postoperative rescue analgesia in the butorphanol group (p<0.05). Statistically significant difference was found among the groups in respect to complete amnesia (50% in group I vs 80% I group II, p<0.05) and recollection (40% in group I vs 10% in group II, p<0.05). CONCLUSION: Oral butorphanol is comparable to oral midazolam in children but analgesia along with sedation is an additional advantage which makes it better than midazolam without a significant increase in side effects.

Administration, Oral↗
PubMed2004

Surface ultrastructural studies on the germination, penetration and conidial development of Aspergillus flavus Link:Fries infecting silkworm, Bombyx mori Linn.

Aspergillosis is a common disease of the silkworm Bombyx mori Linn., caused by an insect mycopathogen Aspergillus flavus Link:Fries. The present study reveals the germination, penetration and conidial development of A. flavus on the larval integument of B. mori under SEM. Four different strains (NB18, KA, NB4D2 and NB7) of B. mori was surface inoculated with ca. of 1 x 10(6) conidia/ml. Each conidium germinated on the cuticle approximately 6 h after inoculation, forming a humpy or suctorial appressoria within 24 h. The hyphae which entered into haemocoel 2 day post-inoculation, grew and multiplied extensively, forming a mycelial complex, causing death of the host larva in about 4-5 days. This occurred with minimal breakdown of the internal tissues. Death of the host was followed by ramification of the fungus through the mesodermal and epidermal tissues, leading to larval mummification about 5-6 days after inoculation. Extensive fungal growths on the entire larval body followed, consisting of aerial hyphae, which developed branched conidiophores. The aerial hyphae with abundant conidiophores formed a confluent yellowish green fungal mat over the entire larval body in 6-7 days of post-inoculation. The tip of each emerging conidiophores gradually dilated and developed to become a bulbous head known as the vesicle. A large number of conidiogenous cells were produced over the entire surface of vesicle, which later developed into finger-like projections termed as sterigmata or phialides. The phialides matured within 2 days after the aerial hyphae emerged as evidenced by chains of conidia at their tips. The conidia were globose with externally roughened walls. The life cycle of the fungus on B. mori was completed in six to seven days.

Animals↗
PubMed2001

Plasma concentrations of lipid peroxidation products in children with acute leukaemia.

Acute leukaemia is the most common childhood malignancy. The cause of leukaemia is not known in most of the cases and of late free radicals have been implicated in the pathogenesis of leukaemia. The degree of lipid peroxidation was studied in the present study as a marker of disease activity in 15 patients of acute lymphoblastic leukaemia and 20 healthy age and sex matched individuals served as control. Serum malonaldehyde (MDA) levels were increased in leukaemia and were higher in the active phase of disease as compared to those in remission, Hence, serum MDA estimation in leukaemia can be of help in diagnosis and to predict the chances of relapse.

Biomarkers, Tumor↗
PubMed2000

Effect of smoking on lipid profile, lipid peroxidation and antioxidant status in normal subjects and in patients during and after acute myocardial infarction.

We studied changes in lipid peroxidation, vitamin E status and lipid profile due to smoking in healthy subjects, patients with acute myocardial infarction (MI), and in stabilized patients surviving MI. A significant increase in malondialdehyde (MDA) concentrations was observed in MI patients, more than in smokers (P<0.05), as compared to control. The plasma vitamin E as well as the ratio of vitamin E/lipids were significantly lower in MI patients as compared to stable ischemic heart disease (IHD) patients and controls. Our data show that smoking is associated with lowered antioxidant status in MI.

Adult↗
PubMed2000

Evaluation of oxidative stress before and after control of glycemia and after vitamin E supplementation in diabetic patients.

The present study evaluates the presence of oxidative stress in the uncontrolled diabetic state. Glycemic control reduced the oxidative stress, but total normalization of the parameters of oxidative stress was not achieved, indicating continued oxidant injury despite optimal control of the diabetes. Vitamin E supplementation for 4 weeks in these patients further reduced the oxidative stress, suggesting that vitamin E supplementation might be helpful in reducing free-radical-induced oxidant injury.

Adult↗
PubMed2000

Superoxide anion formation and glutathione levels in patients with preeclampsia.

Increased free radical activity has been implicated in the pathogenesis of preeclampsia. This article investigates the glutathione status in preeclampsia and whether superoxide generation is enhanced in preeclampsia. Venous blood samples were obtained from 30 preeclamptic women and 30 normotensive pregnant women (controls). Superoxide generation and glutathione content were measured. There was a significant increase in superoxide generation and a marked reduction in glutathione content in preeclamptic women as compared to controls (p < 0.001). These results indicate that enhanced superoxide generation and impaired glutathione metabolism may be involved in the pathogenesis of preeclampsia.

Adolescent↗
PubMed2000

Effect of glycemic control and vitamin E supplementation on total glutathione content in non-insulin-dependent diabetes mellitus.

Thirty patients with non-insulin-dependent diabetes mellitus were selected for the study. 15 age-matched healthy volunteers served as controls. Serum malonaldehyde, total glutathione, and vitamin E levels were estimated before and after glycemic control and after 4 weeks of vitamin E supplementation. Both total glutathione and vitamin E levels increased after glycemic control and showed an increase after vitamin E supplementation. Malonaldehyde levels lowered after glycemic control, but remained higher than controls. Since vitamin E supplementation significantly decreased oxidative stress in the present study, it may play a role in reducing free-radical-induced oxidant injury in diabetes mellitus.

Blood Glucose↗
PubMed2000

Role of oxygen free radicals in shock.

AIMS OF THE STUDY: To study lipid peroxidation, magnesium levels (Mg) in plasma and red cells (RBC), superoxide dismutase (SOD) and catalase (CAT) activities in the plasma and RBC of shock patients. METHODOLOGY: Twenty five patients with clinically defined septic shock and 30 healthy volunteers were selected for the study to study the parameters of oxidative stress. RESULTS: Septic shock patients had higher activities of plasma and RBC SOD and CAT activities as compared to control. Also, plasma Mg and malonaldehyde (MDA) levels were higher in shock patients as compared to controls. While, RBC Mg levels were similar in two groups. CONCLUSIONS: The finding of increased concentration of MDA, Mg, SOD and CAT in sepsis implicates oxygen free radicals in the pathophysiology and free radical scavengers may have a role in organ preservation.

Adult↗
PubMed2000

Glutathione levels in health and sickness.

We speculate that the glutathione (GSH) status of human subjects could be an indicator of health and functional age. In this regard, in a study in which, 80 young and 40 elderly healthy individuals were selected as control. We also studied 145 patients with chronic illnesses namely, ischaemic heart disease, diabetes, preeclampsia, cataract, chronic renal failure and leukaemia (age 52 +/- 8.6 years). We observed that all the subjects had high malonadildehyde and low glutathione levels as compared to control. These early observations support the hypothesis that oxidative stress may have an important aetiological rule and antioxidants a potential therapeutic role.

Adult↗
PubMed2000

Oxidative stress after acute myocardial infarction: effect of thrombolytic treatment.

OBJECTIVE: Treatment with thrombolysis plays a crucial role in salvaging the myocardium in myocardial infarction (MI) patients, but reperfusion of ischaemic areas may itself be associated with reperfusion injury mediated by free radical induced oxidation. Hence the present study was planned to evaluate oxidative stress in patients receiving thrombolytic therapy during MI and to compare them with those not receiving thrombolysis. METHODS: Thiobarbituric acid reactive substance (TBARS) was used as a marker of lipid peroxidation in 30 patients after acute MI. Thirteen were treated by intravenous thrombolysis and 17 served as control. Also, vitamin E levels were estimated in these patients. RESULTS: Patients treated with thrombolysis showed a fall in vitamin E and increase in TBARS within first hours. The decrease in vitamin E was independent of a change in cholesterol. However, the levels were similar at 72 hours. CONCLUSION: The results indicate increased free radical production after MI and reperfusion also increases in free radical production and antioxidants may have a part in improving thrombolytic reperfusion of ischaemic myocardium.

Aged↗
PubMed1999

Distribution of blood viscosity values and biochemical correlates in healthy adults.

OBJECTIVE: Increase in the viscosity of blood predict clinical manifestation of atherothrombotic vascular disease. The clinical utility of viscosity measurements in cardiovascular risk factor requires a reference value established from a healthy disease free population. METHODS: Blood viscosity (based on empirical Merill's formula), fibrinogen, haematocrit and lipid profile were measured in 100 fasting healthy nonsmoking adults (50 men, 50 women). RESULTS: The mean (+/- SD) blood viscosity values were 0.030 +/- 0.015 dyne/cm2. Men had higher viscosity values than women. Also, men had higher triglycerides, haematocrit as well as fibrinogen as compared to women. CONCLUSION: This study provides reference values for the blood viscosity, fibrinogen haematocrit and lipid profile. Viscosity measurements may improve identification and risk stratification of patients at high risk for atherothrombotic vascular disease and its complications.

Adult↗