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Biomedical subjects

M Gupta

Publications and source records attributed to M Gupta.

At least 55 records · Page 3Linked to original sources
PubMed1997

Oxidative stress induced by iron in Hydrilla verticillata (l.f.) Royle: response of antioxidants.

The effect of iron (FeCl3) on chlorophyll content, lipid peroxidation product, potassium ion leakage (a measure of damage to the permeability barrier), and antioxidants was studied in Hydrilla verticillata. The effect of iron-induced damage to the plant was compared with those of N-ethyl maleimide (NEM), a sulfhydryl reagent, and cumene hydroperoxide (CHP), an organic peroxide known to induce lipid peroxidation by free radical formation. The level of lipid peroxidation product was increased in the plants treated with Fe, CHP, and CHP + NEM but not with NEM alone. A significant increase in potassium ion leakage to the external solution was observed by the addition of Fe, CHP, and CHP + NEM, while this did not increase significantly in NEM-treated plants. When NEM and CHP were added simultaneously, the results were the same as those obtained with high iron concentrations, suggesting a combined effect of thiol depletion and lipid peroxidation by Fe ions. In addition, the results indicated loss of glutathione (GSH) and increased oxidized glutathione (GSSG) under Fe stress, indicative of oxidative stress. The oxidative stress may increase the production of free radicals and subsequently resulted in peroxidation of lipids. Further, addition of iron increased the activity of superoxide dismutase (SOD) which may be due to enhanced production of oxygen free radical and related tissue damage. The results suggest that iron-induced damage in plants can be ascribed to a direct metal action on thiols and by toxic oxygen species. An increase in lipid peroxidation product and K+ leakage are the primary responses of iron toxicity on membrane damage. However, the decrease in chlorophyll content is part of the overall expression of iron toxicity.

Antioxidants↗
PubMed1997

Ulnar dimelia. Is it a true duplication of the ulna?

Ulnar dimelia (mirror hand) is a rare congenital disorder, characterized by duplication of the ulna, absence of the radius and polydactyly. Approximately 60 cases have been reported worldwide. We present a new case, with its own distinguishing features. These features illustrate that the aetiology of ulnar dimelia is probably failure of differentiation of a part of the ray rather than its pure duplication.

Adolescent↗
PubMed1997

Anti-steroidogenic activity of the petroleum ether extract and fraction 5 (fatty acids) of carrot (Daucus carota L.) seeds in mouse ovary.

The petroleum ether extract and fraction 5 (fatty acids) of carrot seeds arrested the normal estrus cycle of adult mouse and reduced the weight of ovaries significantly. The cholesterol and ascorbic acid content in ovaries were significantly elevated due to the treatment with extract and fraction 5 (fatty acids) of carrot seeds. The significant inhibition of delta 5,3-beta-hydroxy steroid dehydrogenase and glucose-6-phosphate dehydrogenase, the two key enzymes involved in ovarian steroidogenesis, were also observed in mouse ovaries after 15 days of treatment. Results of this study revealed that the fraction 5 (fatty acids) present in carrot seeds acts as an antisteroidogenic agent.

Alkanes↗
PubMed1997

Pressure modulates monocyte migration.

Migration of monocytes into the subendothelial space of the aorta has been considered to be an important event in the development of atherosclerosis. Because hypertension is commonly associated with atherosclerosis, we studied the effect of applied pressure on the migration of monocytes. Direct applied pressure increased the migration (P < .001) of monocytes across a filter when compared with normal atmospheric pressure. The migration of monocytes was found to be directly related to the amount of the applied pressure. Amlodipine, a calcium channel blocker, attenuated the migration of monocytes under normal as well as increased pressure conditions in a dose-dependent manner. These studies provide a basis to speculate on the role of direct pressure in the migration of monocytes into the subendothelial space and the possibility that vasoactive agents may modulate the migration of monocytes independent of their pressure-lowering effect.

Amlodipine↗
PubMed1997

Inhibition of calcium oxalate urolithiasis in a rat model of lithogenesis using bisphosphonates.

Bisphosphonates bind renal calculi and inhibit calcium oxalate crystal growth in vitro. We evaluated their ability to inhibit calcium oxalate urolithiasis in a lithogenic rat model. Male Sprague-Dawley rats (four groups, eight rats each) were fed 1.0% ethylene glycol in their drinking water for 6 weeks. All rats had implantation of a 50- to 60-mg zinc pellet in their urinary bladder at the beginning of the 6-week period. The control group received no treatment. The other three groups received six weekly intraperitoneal injections of one of three bisphosphonates: pamidronate (APD), clodronate (CLO), or methylene diphosphonate (MDP). At the end of 6 weeks, the zinc pellet was retrieved and weighed; the kidneys were sectioned and stained to evaluate inflammation, tubular dilation, and crystal deposition; and blood and urine samples were analyzed for calcium and creatinine. There were no detectable biochemical differences between the control and the treatment groups. Zinc pellets removed from control animals had a significantly greater increase in weight secondary to crystal deposition than those from the treatment groups (mean 28.4% for control v 18.9%, 15.3%, and 18.6%, respectively, for animals given APD, CLO, and MDP). The control animals also had significantly higher scores for inflammation, tubular dilation, and crystal deposition than animals treated with MDP and CLO. Older and newer-generation bisphosphonates have an inhibitory effect on calcium oxalate urolithiasis that is demonstrable at relatively infrequent dosing intervals in vivo. More frequent dosing or higher doses may allow greater inhibition of stone formation.

Analgesics, Non-Narcotic↗
PubMed1997

Accuracy of oscillometric blood pressure monitoring in pregnancy and pre-eclampsia.

OBJECTIVE: To assess the accuracy of the Omron HEM 705 CP oscillometric device for the measurement of blood pressure in pregnancy and pre-eclampsia. SETTING: Two teaching hospitals. PARTICIPANTS: Eighty-five pregnant women with a wide range of blood pressures, and 43 women with pre-eclampsia. METHODS: Evaluation was carried out according to the British Hypertension Society protocol, incorporating criteria of the Association for the Advancement of Medical Instrumentation (AAMI). RESULTS: Mean differences (device minus observer) for systolic blood pressure were -0.9 mmHg (SD 10) in normal pregnancy, and -2 mmHg (SD 10) in the women with pre-eclampsia. For diastolic blood pressure, Korotkoff phase V, the differences were -1.5 mmHg (SD 10), and -8 mmHg (SD 8) respectively; i.e. the device consistently under-read the diastolic blood pressure in pre-eclamptic women by a mean of 8 mmHg when compared with conventional sphygmomanometry. Korotkoff phase IV could not be accurately reproduced. According to the British Hypertension Society grading criteria, the device reached a 'B' grading in the 85 pregnant women. In pre-eclampsia only a 'C' grade was reached for systolic blood pressure, and 'D' grade for diastolic blood pressure. Accuracy criteria stipulated by the AAMI were not met in any situation. CONCLUSION: The Omron HEM 705 CP does not reach acceptable accuracy criteria for blood pressure measurement when compared with trained observers in women with pre-eclampsia, as judged by the British Hypertension Society Protocol. It also failed to meet the AAMI criteria, although the methodology stipulated by the AAMI may not be applicable to a pregnancy population.

Blood Pressure↗
PubMed1997

Detection of immunoglobulin G (IgG) and IgM antibodies to Toxoplasma gondii: evaluation of four commercial immunoassay systems.

A comparative evaluation of the following commercial immunoassays for the determination of antibodies to Toxoplasma gondii was performed: Behring Diagnostics OPUS Toxo G and Toxo M, Abbott Diagnostics IMX Toxo-IgG 2.0 and Toxo-IgM, Sanofi Diagnostics Pasteur Platelia Toxo IgG and Toxo IgM, and bioMérieux Vitek VIDAS Toxo IgG and IgM. Of 676 specimens that were tested for Toxoplasma-specific immunoglobulin G (IgG) antibodies, 26% were reactive by all methods while 8% displayed some discrepancy. Of 718 specimens that were tested for Toxoplasma-specific IgM antibodies, 3% were reactive by all methods while 10% displayed some discrepancy. Analysis of discrepant specimens revealed performance shortcomings with all IgM-specific assays. The impact of such shortcomings is magnified in a population with a low prevalence of toxoplasmosis.

Animals↗
PubMed1997

Controlled comparison of bioMérieux VITAL and BACTEC NR-660 systems for detection of bacteremia and fungemia in pediatric patients.

The bioMérieux VITAL automated blood culture system measures a decrease in fluorescence to detect the presence of microorganisms in blood. To assess the performance of VITAL with AER aerobic medium versus that of the nonradiometric BACTEC NR-660 PEDS PLUS medium for the detection of sepsis in children, a total of 12,146 blood specimens were collected at three university medical centers and inoculated into AER and PEDS PLUS bottles that were weighed before and after filling. The sample volumes were considered adequate in 6,276 bottle pairs. The total yield of isolates was 629, of which 489 (78%) were judged to be the cause of true infections. Staphylococci (P < 0.001) and yeasts (P < 0.05) were detected more often in PEDS PLUS bottles, as were all microorganisms combined (P < 0.001). The improved detection in the PEDS PLUS medium was most marked for patients on antimicrobial therapy (P < 0.001), but remained statistically significant even for patients not on therapy (P < 0.025). There were 431 episodes of sepsis, including 407 considered adequate for analysis. Of the 363 unimicrobial episodes, 278 were detected by both bottles, 64 were detected by PEDS PLUS bottles only, and 21 were detected by AER bottles only (P < 0.01). No false-negative cultures were detected by terminal subculture of the PEDS PLUS bottles when the companion AER bottle was positive. However, there were 14 false-negative cultures (7 yeasts, 5 staphylococci, 1 Enterococcus faecalis, and 1 Enterobacter sp.) on terminal subculture of the AER bottles when the companion PEDS PLUS bottle was positive. When both systems were positive, the VITAL system detected bacteria earlier than did the BACTEC system by a mean of 1.6 h. Also, false-positive signals were less common with the VITAL system. We conclude that the VITAL system with AER medium must be modified to improve the detection of clinically important staphylococci and yeasts if it is to perform comparably to the BACTEC NR-660 nonradiometric system with PEDS PLUS medium for a pediatric population.

Bacteremia↗
PubMed1997

Transcription enhancer factor 1 interacts with a basic helix-loop-helix zipper protein, Max, for positive regulation of cardiac alpha-myosin heavy-chain gene expression.

The M-CAT binding factor transcription enhancer factor 1 (TEF-1) has been implicated in the regulation of several cardiac and skeletal muscle genes. Previously, we identified an E-box-M-CAT hybrid (EM) motif that is responsible for the basal and cyclic AMP-inducible expression of the rat cardiac alpha-myosin heavy chain (alpha-MHC) gene in cardiac myocytes. In this study, we report that two factors, TEF-1 and a basic helix-loop-helix leucine zipper protein, Max, bind to the alpha-MHC EM motif. We also found that Max was a part of the cardiac troponin T M-CAT-TEF-1 complex even when the DNA template did not contain an apparent E-box binding site. In the protein-protein interaction assay, a stable association of Max with TEF-1 was observed when glutathione S-transferase (GST)-TEF-1 or GST-Max was used to pull down in vitro-translated Max or TEF-1, respectively. In addition, Max was coimmunoprecipitated with TEF-1, thus documenting an in vivo TEF-1-Max interaction. In the transient transcription assay, overexpression of either Max or TEF-1 resulted a mild activation of the alpha-MHC-chloramphenicol acetyltransferase (CAT) reporter gene at lower concentrations and repression of this gene at higher concentrations. However, when Max and TEF-1 expression plasmids were transfected together, the repression mediated by a single expression plasmid was alleviated and a three- to fourfold transactivation of the alpha-MHC-CAT reporter gene was observed. This effect was abolished once the EM motif in the promoter-reporter construct was mutated, thus suggesting that the synergistic transactivation function of the TEF-1-Max heterotypic complex is mediated through binding of the complex to the EM motif. These results demonstrate a novel association between Max and TEF-1 and indicate a positive cooperation between these two factors in alpha-MHC gene regulation.

Animals↗
PubMed1997

Characterisation of the antibody response to the extracellular region of recombinant thyrotropin receptor.

Autoantibodies to the human thyrotropin receptor (TSH-R) are pathogenic in a number of autoimmune thyroid diseases including Graves' disease. We have characterised polyclonal antisera to TSH-R for antibodies which may mimic those present in autoimmune thyroid disease. For immunisations, recombinant extracellular region of human TSH-R which does not interact with its ligand TSH was used. The induced antibodies react with the full length membrane receptor in transfected mammalian cells by flow cytometry showing the presence of antibody capable of recognising the native functional receptor. The properties of the generated antibodies have been compared after two injections or following a multiple immunisation protocol with the receptor in adjuvant. High titre antisera were readily generated after the short injection protocol and further immunisations did not lead to any change in antibody titers. Analysis of the epitopes recognised using synthetic peptides confirmed previous observations that the immunodominant determinants localise to the amino and the carboxyl terminal part of the extracellular region of the receptor. Antisera from both rabbits contain TSH blocking antibody as assessed by inhibition of TSH mediated cAMP stimulation. There was an increase in TSH binding inhibitory immunoglobulin (TBII) activity with multiple injections. Furthermore, the increase in TBII activity was not related to spreading of the antibody response to new determinants on TSH-R. Our results support previous observations on the difficulties in reproducing, by adjuvant immunisation with recombinant TSH-R preparations, the fine specificity of antibodies to TSH-R present in autoimmune disorders such as Graves' disease or primary myxoedema.

Animals↗
PubMed1997

Massive hemorrhage from renal vein injury during percutaneous renal surgery: endourological management.

PURPOSE: Although minor venous injuries respond to simple maneuvers, major venous injuries pose a significant therapeutic problem and may be under diagnosed. We present our experience with major injury to the renal vein during percutaneous renal surgery. MATERIALS AND METHODS: Four patients had massive hemorrhage during percutaneous renal surgery associated with major injury to the renal vein, and 3 also had renal insufficiency. All 4 patients and 1 additional patient with renal insufficiency and massive hemorrhage from an arteriovenous fistula following percutaneous renal surgery were treated nonoperatively with a selectively positioned and inflated Council balloon catheter. RESULTS: Hemorrhage was controlled and renal function was unaffected in all 5 patients. CONCLUSIONS: Renal vein injuries can be associated with massive hemorrhage. Patients with major vascular injuries from percutaneous renal surgery and concomitant renal insufficiency can be treated without open exploration or angiographic embolization using a Council balloon catheter.

Aged↗
PubMed1997

Open surgical exploration after failed endopyelotomy: a 12-year perspective.

PURPOSE: Factors that have a role in endopyelotomy failure have not been fully elucidated but are believed to include high grade hydronephrosis and the presence of crossing vessels at the ureteropelvic junction. MATERIALS AND METHODS: We retrospectively analyzed the importance of renal function, hydronephrosis, ureteral stents, surgeon experience and crossing vessels in determining the outcome of endopyelotomy. RESULTS: Of 401 percutaneous antegrade endopyelotomies performed at our medical center during the last 12 years 60 failed and 54 of these patients underwent surgical exploration. Patients with high grade hydronephrosis and poor initial renal function were much less likely to have successful endopyelotomy than those with moderate hydronephrosis or good renal function (success rates 50 versus 96 and 54 versus 92%, respectively, p <0.001). The most common findings at exploration included severe extrinsic fibrosis and intrinsic fibrotic stenosis. Obstructing crossing vessels were present in 13 patients explored, suggesting a possible role in causing failure in only 4% of all endopyelotomy patients. CONCLUSIONS: Patients with high grade hydronephrosis and poor initial renal function are much more likely to experience endopyelotomy failure. Crossing vessels appear to have a less significant role in endopyelotomy failure than has been previously suggested.

Adolescent↗
PubMed1997

Serum CA-125 measurements > 65 U/mL. Clinical value.

OBJECTIVE: To review the prevalence of various conditions associated with serum CA-125 values > 65 U/mL, to calculate the odds ratios of different ranges of high CA-125 in predicting cancer and to study the effect of menopause and the presence of a mass on the predictive value of high serum CA-125. STUDY DESIGN: A retrospective review of the diagnoses in 313 consecutive women seen at the Cleveland Clinic Foundation whose serum CA-125 was > 65 U/mL was performed. Statistical analysis was performed using crosstabulation, chi 2, Fisher's exact test and the odds ratio. RESULTS: In patients with serum CA-125 > 65 U/mL, gynecologic cancers, nongynecologic cancers and non-malignant conditions constituted 74.3%, 10.2% and 13.1% of diagnoses, respectively. In patients with serum CA-125 > or = 1,000 U/mL, the same conditions were responsible for 89%, 7% and 3% of diagnoses, respectively. Endometriosis and metastatic breast cancer were the most common benign condition and nongynecologic cancer associated with serum CA-125 > 65 U/mL. The presence of an abdominopelvic mass significantly increased the risk of malignancy (P < .00005). Approximately 90% of patients with CA-125 > 65 U/mL and no mass had nonmalignant disease. The diagnoses of serum CA-125 values > 65 U/mL varied significantly in premenopausal versus postmenopausal patients. Postmenopausal patients had a higher incidence of gynecologic (P = .002) and nongynecologic (P = .0008) cancers and lower incidence of benign conditions (P < .0005). The odds ratio that CA-125 levels were associated with cancer increased as the level of CA-125 increased. The odds ratio of malignant versus benign disease was significantly higher in post-menopausal patients for all intervals of CA-125 levels until the level of > or = 1,000 U/mL was reached. CONCLUSION: In patients seen at a tertiary center, serum CA-125 measurements > 65 U/mL were associated with nonmalignant conditions in 13% of patients. Although higher serum CA-125 levels were more associated with gynecologic malignancies, no level of CA-125 occurred exclusively with gynecologic cancers. In postmenopausal patients with serum CA-125 values > 65 U/mL and in patients with serum CA-125 values > 65 U/mL and an abdominopelvic mass, subspecialty consultation should be considered before proceeding to surgery.

Adult↗
PubMed1997

Antitumor activity of Hygrophila spinosa on Ehrlich ascites carcinoma and sarcoma-180 induced mice.

Petroleum ether extract from H. spinosa root exhibited antitumor activity in Ehrlich ascites carcinoma and Sarcoma-180 bearing mice Processed extract suppressed significantly the tumor fluid volume at the end of 3 weeks experiment. It decreased about 50% of packed cell volume and increased life span of EAC/S-180 bearing mice in a day dependent manner. Red blood cell count, hemoglobin content and white blood cell count were more or less normal after processed extract treatment of the tumor bearing mice. In tumor control animals, neutrophils increased (273.7% in EAC and 263.4% in S-180 bearing mice respectively with respect to normal mice) whereas lymphocytes decreased (60.0% in EAC and 56.5% in S-180 bearing mice respectively with respect to normal mice). It also inhibited the rapid increase of body weight of tumor bearing mice.

Animals↗
PubMed1997

Cardiac hypertrophy: old concepts, new perspectives.

Growth of the heart in hypertrophy is accompanied by changes in the phenotypic expression of cardiac genes. To explore the molecular basis of cardiac hypertrophy, we have analyzed the regulation of myosin heavy chain gene (MHC) expression. In one set of experiments, pressure overload on the rat heart was produced by constriction of the abdominal aorta. Changes in the alpha and beta-MHC mRNA were then studied in overloaded hearts and following load removal. Pressure overload resulted in down-regulation of the alpha-MHC with corresponding up-regulation of the steady state level of beta-MHC mRNA. Load removal (debanding) resulted in regression of cardiac hypertrophy and a rapid return of alpha-MHC mRNA to normal values. In contrast, the recovery in beta-MHC mRNA was much slower to the extent that it remained substantially elevated compared to respective sham controls even after 7 weeks of post-debanding. These results suggest that putative load-related signals independently regulate two genes. Several lines of evidence indicate that adrenergic nervous system plays an important role in the induction and maintenance of cardiac hypertrophy and in the redistribution of myosin isoforms. We have analyzed the effect of cAMP inducing agents on the regulation of alpha-MHC gene in primary cultures of the fetal (18 day) rat cardiac myocyte. Inclusion of 8 Br-cAMP in the culture media increased the expression of alpha-MHC promoter/reporter construct comprising of 2.9 kb upstream sequence of the alpha-MHC gene. Several deletion mutations in the alpha-MHC gene promoter defined the cAMP responsive boundaries to be a 32 bp region comprising of -71 to -40 bp sequences. Deletion of this region resulted in loss of cAMP response as well as in basal expression of alpha-MHC promoter/reporter construct. These data suggest a role of beta-adrenergic pathway in the modulation of alpha-MHC gene expression.

Animals↗
PubMed1997

Studies on hepatic injury and antioxidant enzyme activities in rat subcellular organelles following in vivo ischemia and reperfusion.

The activities of rat hepatic subcellular antioxidant enzymes were studied during hepatic ischemia/reperfusion. Ischemia was induced for 30 min (reversible ischemia) or 60 min (irreversible ischemia). Ischemia was followed by 2 or 24 h of reperfusion. Hepatocyte peroxisomal catalase enzyme activity decreased during 60 min of ischemia and declined further during reperfusion. Peroxisomes of normal density (d = 1.225 gram/ml) were observed in control tissues. However, 60 min of ischemia also produced a second peak of catalase specific activity in subcellular fractions corresponding to newly formed low density immature peroxisomes (d = 1.12 gram/ml). The second peak was also detectable after 30 min of ischemia followed by reperfusion for 2 or 24 h. Mitochondrial and microsomal fractions responded differently. MnSOD activity in mitochondria and microsomal fractions increased significantly (p < 0.05) after 30 min of ischemia, but decreased below control values following 60 min of ischemia and remained lower during reperfusion at 2 and 24 h in both organelle fractions. Conversely, mitochondrial and microsomal glutathione peroxidase (GPx) activity increased significantly (p < 0.001) after 60 min of ischemia and was sustained during 24 h of reperfusion. In the cytosolic fraction, a significant increase in CuZnSOD activity was noted following reperfusion in animals subjected to 30 min of ischemia, but 60 min of ischemia and 24 h of reperfusion resulted in decreased CuZnSOD activity. These studies suggest that the antioxidant enzymes of various subcellular compartments respond to ischemia/reperfusion in an organelle or compartment specific manner and that the regulation of antioxidant enzyme activity in peroxisomes may differ from that in mitochondria and microsomes. The compartmentalized changes in hepatic antioxidant enzyme activity may be crucial determinant of cell survival and function during ischemia/reperfusion. Finally, a progressive decline in the level of hepatic reduced glutathione (GSH) and concomitant increase in serum glutamate pyruvate transaminase (SGPT) activity also suggest that greater tissue damage and impairment of intracellular antioxidant activity occur with longer ischemia periods, and during reperfusion.

Alanine Transaminase↗