PubMed Health⌕ Search

Biomedical subjects

A Gulati

Publications and source records attributed to A Gulati.

At least 19 recordsLinked to original sources
PubMed2006

A comparative evaluation of ear diseases in children of higher versus lower socioeconomic status.

This study was conducted with an aim to assess the prevalence and profile of ear diseases in children from the higher and lower socioeconomic strata of society. Two groups of schools within Delhi were selected. Group A comprised of government schools located in slum areas with an average parental income of INR (Indian National Rupees) 1050 per month and group B of elite private schools with an average family income of TNR 35,000 per month. Three thousand children between the ages of 5-12 years were screened with the help of a written proforma and ear examination. Tympanometry and audiometry were done, where required. 19.6 per cent of children of group A were found to be suffering from ear diseases compared to 2.13 per cent of group B children. The two groups were also compared for number of family members, status of hygiene and parental education.

Baths↗
PubMed2006

Specialist dermatology clinics for organ transplant recipients significantly improve compliance with photoprotection and levels of skin cancer awareness.

BACKGROUND: Organ transplant recipients (OTRs) have 100-fold increased risk of developing squamous cell carcinomas. Cumulative exposure to ultraviolet radiation is the main risk factor and there is evidence that lack of dermatological surveillance may be responsible for poor levels of knowledge and photoprotection among OTRs. OBJECTIVES: This study evaluated whether routine consultation in a specialist OTR dermatology clinic improves understanding of skin cancer risk and compliance with photoprotection measures. METHODS: A cross-sectional questionnaire-based study was performed in a specialist OTR dermatology clinic at Bart's and the London NHS Trust, London, U.K. The subjects were 399 white-skinned patients under surveillance in a renal transplant clinic, who were sent a postal questionnaire from the renal transplant clinic. The main outcome measures were responses to the questionnaire regarding photoprotective practices and skin cancer risk awareness. RESULTS: Two hundred and ninety-two of 399 (73%) responded, of whom 89% had previously attended the specialist dermatology clinic. Ninety-six per cent recalled receiving photoprotection advice at least once (85% from dermatologists); 92% reported use of sunscreen; 88% specifically dressed to photoprotect themselves; 96% directly avoided sun exposure during summer; 68% were aware that an increased risk of skin cancer was the reason that extra photoprotective measures were important after a transplant. Photoprotective measures and level of skin cancer awareness were significantly lower in those responders who had never attended the specialist clinic. No obvious bias was identified among nonresponders. CONCLUSIONS: Skin cancer awareness and compliance with photoprotective measures in our patient population is generally greater than previously reported, suggesting that delivery of educational messages regarding skin cancer may be improved if provided in a specialist dermatological setting.

Cross-Sectional Studies↗
PubMed2006

Determination of endothelin antagonist BMS182874 in plasma by high-performance liquid chromatography.

A simple and rapid high performance liquid chromatography (HPLC) method was developed for the determination of BMS182874 (BMS) in mouse plasma. The drug was extracted from plasma by a liquid-liquid extraction process. The method consists of reversed-phase chromatography using a Thermo Hypersil-Keystone RP-18 5 microm, 250 x 2.1 mm column and UV spectrophotometer detection at 255 nm. The mobile phase consists of 45% (v/v) acetonitrile: 55% (v/v) trifluoroacetic acid (0.015% v/v; pH 3.0) at a flow rate of 0.6 ml/min. Validity of the method was studied and the method was precise and accurate with a linearity range from 100 ng/ml to 1000 ng/ml. The extraction efficiency was found to be 81, 84 and 87% for 100, 500 and 1000 ng/ml, respectively for spiked drug in plasma. The limit of quantification and limit of detection were found to be 50 and 10 ng/ml, respectively in plasma. Within-day and between-day precision expressed by relative standard deviation was less than 4% and inaccuracy did not exceed 4%. The assay was also used to analyze samples collected during animal studies. The suitability and robustness of the method for in vivo samples were confirmed by analysis of BMS from mouse plasma and tissues dosed with BMS.

Animals↗
PubMed2005

By what mechanism do leeches help to salvage ischaemic tissues? A review.

The therapeutic use of leeches in medicine dates back to 50 b.c. and was cited by ancient authors. The medicinal leech, Hirudo medicinalis, has been used with increasing frequency during the past few years by reconstructive surgeons to help salvage ischaemic tissues. We aim to summarise the anatomy, physiology, and pharmacological mechanisms of action of leeches to provide reconstructive surgeons with a theoretical basis for their use.

Animals↗
PubMed2004

Eosinophilic gastroenteritis presenting as obstructive jaundice.

Eosinophilic gastroenteritis is a rare condition of unknown aetiology, first described by Kaijser in 1937. It is manifest by eosinophilic infiltration of the gastrointestinal tract and peripheral eosinophilia. Patients have various clinical presentations depending on the region of the gastrointestinal tract involved and the depth and extent of the bowel wall involvement. Whereas gastrointestinal obstruction associated with this condition is not uncommon, isolated biliary obstruction has only been reported twice. We present a case of eosinophilic gastroenteritis with involvement of the biliary tract causing ulceration, fibrosis and obstruction. Although a rare condition, we believe the diagnosis of eosinophilic gastroenteritis should be entertained in patients with gastrointestinal symptoms and a peripheral eosinophilia who have no evidence of parasitic infection, vasculitis or neoplasms.

Adult↗
PubMed2001

Modulation of diaspirin crosslinked hemoglobin induced systemic and regional hemodynamic response by ethanol in normal rats.

DCLHb, a hemoglobin based oxygen carrier, has been extensively studied for the treatment of hemorrhagic shock in both animal models and humans. Numerous accidents resulting in trauma are due to ethanol intoxication, in particular cases of car accidents. Therefore, trauma patients might be intoxicated with drugs of abuse like ethanol. Ethanol has significant effects on the cardiovascular system including peripheral vasodilation and decreased myocardial contractility. Such effects are likely to alter the cardiovascular actions of DCLHb, a resuscitative agent. Hence, this study investigated the effect of ethanol on the cardiovascular actions of DCLHb. Urethane anesthetized male Sprague-Dawley rats were divided into following groups (i) Saline + DCLHb (400 mg/kg) (n = 9), (ii) Ethanol (1 g/kg) + DCLHb (400 mg/kg) (n = 9), and (iii) Ethanol (4 g/kg) + DCLHb (400 mg/kg) (n = 8). Cardiovascular parameters were determined using a radioactive microsphere technique. DCLHb when administered to saline treated rats produced an increase in MAP, TPR, decreased renal and hepatic blood flow and increased blood flow to the skin and mesentery & pancreas. A high dose of ethanol (4 g/kg) significantly attenuated the DCLHb induced pressor response (p < 0.05) and increase in TPR (p < 0.05). Cardiac output was severely reduced by DCLHb in rats treated with high dose ethanol as compared to saline. No changes in TPR and cardiac output were observed in the low dose ethanol (1 g/kg) group. DCLHb reduced blood flow to the heart and mesentery & pancreas in rats treated with high dose ethanol. DCLHb caused a decrease in musculo-skeletal vascular resistance in rats treated with high dose ethanol. This decrease in vascular resistance in the musculo-skeletal system appears to be contributing to a decrease in TPR. It is concluded that ethanol in higher doses significantly alters the hemodynamic effects of DCLHb and may interfere with the resuscitative effects of DCLHb.

Animals↗
PubMed2001

Sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease): report of two cases with fine-needle aspiration cytology.

Sinus histiocytosis with massive lymphadenopathy (SHML) or Rosai-Dorfman disease is a rare but well-defined histiocytic proliferative disorder. There are only few reports or small series of cases on the fine-needle aspiration (FNA) cytologic features of this entity. Our first case was a 14-yr-old girl who presented with low-grade fever and neck swellings of 2 mo duration. FNA smears from the submandibular and cervical lymph nodes showed numerous histiocytes with evidence of lymphophagocytosis (emperipolesis) against a background of reactive lymphoid cells. The FNA cytodiagnosis was Rosai-Dorfman disease. The patient was put on steroids, with improvement. The second patient was a 3(1/2)-yr-old girl who presented with fever and left cervical lymphadenopathy. The initial FNA smear from an outside laboratory was reported as reactive hyperplasia. A repeat FNA smear showed numerous histiocytes with evidence of emperipolesis, mild nuclear enlargement and multilobation/multinucleation in a few histiocytes, and reactive lymphoid cells. The cytodiagnosis was Rosai-Dorfman disease. Review of the initial smear showed the Rosai-Dorfman (RD) cells, but in smaller number. We conclude that FNA cytology is a useful tool in the diagnosis of SHML, but the diagnosis may be missed at initial stages when characteristic cytomorphologic features are not well-developed.

Adolescent↗
PubMed2001

The Escherichia coli antiterminator protein BglG stabilizes the 5'region of the bgl mRNA.

The beta-glucoside utilization (bgl) genes of Escherichia coli are positively regulated by the product of the bglG gene, which functions as an antiterminator by binding to specific sequences present within the bgl mRNA. BglG is inactivated by phosphorylation in the absence of beta-glucosides by BglF, the bgl-specific component of the phosphotransferase system (PTS). Here, we present evidence for an additional function for BglG, namely the stabilization of the 5' end of the bgl mRNA. Half-life measurements of the promoter-proximal region of the bgl mRNA indicate a five fold enhancement of stability in the presence of active (unphosphorylated) BglG. This enhancement is lost when the binding of BglG to mRNA is prevented by deletion of the binding site. Interestingly, stabilization by BglG does not extend to downstream sequences. The enhanced stability of the upstream sequences suggest that BglG remains bound to its target on the mRNA even after the downstream sequences have been degraded. Implications of these observations for the mechanism of positive regulation of the operon by BglG are discussed.

Bacterial Proteins↗
PubMed2001

Pharmacokinetics of diaspirin cross-linked haemoglobin in a rat model of hepatic cirrhosis.

The aim of the study was to evaluate the effect of cirrhosis on the disposition of the haemoglobin-based oxygen carrier, diaspirin cross-linked haemoglobin (DCLHb). Cirrhosis was induced in male Sprague-Dawley rats (200-250 g) by inhalational exposure to carbon tetrachloride (CCl4), over a period of 6 weeks. Pharmacokinetic evaluation was performed after a single intravenous bolus administration of DCLHb (400 mg kg(-1)). Serum biochemistry, including aspartate transaminase, alkaline phosphatase, bile acids, serum albumin, and serum creatinine, were measured in CCl4-treated (n = 6) and age-matched control (n = 6) rats. After 6 weeks, the jugular vein and carotid artery were cannulated for bolus DCLHb administration (400 mg kg(-1)) and blood sampling, respectively, in both groups of rats. Cirrhosis produced significant (P < 0.05) elevations in alkaline phosphatase (497.4 +/- 84.8 U L(-1) vs 241.2 +/- 5.1 U L(-1)), aspartate transaminase (920.5 +/- 190.9 U L(-1) vs 238.2 +/- 118.1 U L(-1)) and bile acids (333.8 +/- 77.3 mg dL(-1) vs 43.8 +/- 4.2 mg dL(-1)) compared with the control group. No significant renal dysfunction was observed as a result of CCl4 exposure. Plasma DCLHb concentrations declined approximately log-linearly. Systemic clearance of DCLHb was estimated to be 2.2 +/- 0.7 mL h(-1) in the treatment group and was slightly, but not significantly, less in the control group (3.6 +/- 1.7 mL h(-1)). There was also a trend toward a longer elimination half-life in the treatment group (4.7 +/- 2.2 h) compared with the control group (3.8 +/- 0.8 h), although this difference was not statistically significant. Cirrhosis does not significantly alter the disposition of DCLHb perhaps due to increased extra-hepatic metabolism by the reticulo-endothelial system.

Animals↗
PubMed2001

Formation of 6-formyl-7-hydroxy-8-methoxycoumarin and 5,8-dioxopsoralen by reaction of 8-methoxypsoralen with H2O2 and potassium superoxide (KO2) catalyzed by halogenated or perhalogenated 5,10,15,20-tetraarylporphyrinatoiron(III) chlorides.

The oxidation of 8-methoxypsoralen (2) with hydrogen peroxide and potassium superoxide catalyzed by 5,10,15,20-(2,4,6-trimethylphenyl)porphyrinatoiron(III) chlorides [Me12TPPFe(III)Cl] (1a) and 5,10,15,20-(2,6-dichlorophenyl)porphyrinatoiron(III) chlorides [Cl8TPPFe(III)Cl] (1b) in dichloromethane gives 6-formyl-7-hydroxy-8-methoxycoumarin (3) in moderate yields, whereas the oxidation of (2) with H2O2 catalyzed by 5,10,15,20-(2,6-dichlorophenyl)-beta-octahaloporphyrinatoiron(III) chlorides [Cl8betaX8TPPFe(III)Cl] (X=Cl, Br) (1c, 1d) gives specifically 5,8-dioxopsoralen (4) in moderate yields.

Catalysis↗
PubMed2000

Resuscitative effects of polynitroxylated alphaalpha-cross-linked hemoglobin following severe hemorrhage in the rat.

alphaalpha-Cross-linked hemoglobin (alphaalphaHb) is an example of a hemoglobin-based oxygen carrier (HBOC) with significant cardiovascular activity. This may compromise the safety and efficacy of this HBOC by causing systemic hypertension and reducing blood flow to some organs. The present work is based on the hypothesis that incorporating antioxidant activity into an HBOC in the form of a covalently attached nitroxide may prevent these effects. We have tested this hypothesis by adding antioxidant activity to alphaalphaHb with 2,2,6,6-tetramethyl-piperidinyl-1-oxyl (Tempo) to create polynitroxylated alphaalphaHb (PN-alphaalphaHb). The new compound PN-alphaalphaHb acts as an antioxidant in our in vitro and in vivo assays. In this study urethane-anesthetized rats were hemorrhaged to a mean arterial pressure (MAP) of 35-40 mmHg and maintained for 30 min. Animals were resuscitated with solutions of (1) 10% PN-alphaalphaHb (43 mmHg), (2) 10% alphaalphaHb (43 mmHg), (3) 7.5% albumin (43 mmHg), (4) 300% Ringers lactate (RL), and (5) 0. 9% normal saline equal to the shed blood volume (SBV). Hemodynamics and regional blood circulation was measured at baseline, following hemorrhage, and at 30 and 60 min postresuscitation using a radioactive microsphere technique. Base deficit (BD) was measured at baseline, following hemorrhage, and at 60 min following resuscitative fluid infusion. Finally survival was determined as the time following resuscitation until secession of heart rhythm. Saline and 300% RL resuscitation did not improve BD, systemic hemodynamics, or regional blood circulation. PN-alphaalphaHb, alphaalphaHb, and albumin significantly improved these parameters, however, only PN-alphaalphaHb and alphaalphaHb improved survival. PN-alphaalphaHb was found to be less hypertensive than alphaalphaHb due to blunted increases in both cardiac output and systemic vascular resistance. This study demonstrates that, by using alphaalphaHb as a scaffold for polynitroxylation, improvement in vasoactivity and resuscitative efficacy may be possible. In conclusion, the addition of antioxidant activity in the form of polynitroxylation of a low molecular weight Hb (alphaalphaHb) may create a safe and efficacious resuscitative fluid.

Animals↗
PubMed2000

Preface

Explore the source record for details and available documents.

Journal Article↗
PubMed2000

Purification and chemical modifications of hemoglobin in developing hemoglobin based oxygen carriers.

The efficacy of blood substitutes, as a whole, has been readily demonstrated, in animals as well as clinical studies. It is well known that stroma free hemoglobin (SF-Hb) is very toxic, due to effects on renal and coagulation functions and vascular tone. Several modifications have been made to the hemoglobin tetramer in an attempt to eliminate its toxicity. Conjugation, cross-linking, polymerization, and recombinant technology have all been used to reduce toxicity, while aiming to optimize the therapeutic value of hemoglobin based blood substitutes. The remaining issue seems to be the hypertensive response seen in many hemoglobin solutions. The cause of the hypertensive response, and hence what chemical modifications are suitable to alleviate it are still under debate.

Animals↗
PubMed2000

Current aspects in pharmacology of modified hemoglobins.

Blood substitutes are products that are designed to replace whole blood (or) red blood cells in the field of transfusion medicine. There are two major classes that belong to this new therapeutics: (i) modified hemoglobins and (ii) perfluorocarbons. Modified hemoglobins have made tremendous progress in the past decade and are being considered for a wide variety of conditions like trauma, elective surgery, oxygenation of tumors to make them more sensitive to radiation therapy, stroke etc. Although, these agents are primarily used for oxygen delivery, their pharmacological actions have been significantly important. Several mechanisms are being explored to explain these pharmacological effects. Modified hemoglobins suffer several drawbacks including hypertension, renal toxicity, and pulmonary hypertension that restrict their development. This review deals with the clinical status and pharmacological actions of modified hemoglobins presently in advanced stages of development and some of the newer generation hemoglobin based therapeutics are also discussed.

Animals↗
PubMed2000

Mechanism of catabolite repression in the bgl operon of Escherichia coli: involvement of the anti-terminator BglG, CRP-cAMP and EIIAGlc in mediating glucose effect downstream of transcription initiation.

BACKGROUND: Expression of the bgl operon of Escherichia coli, involved in the regulated uptake and utilization of aromatic beta-glucosides, is extremely sensitive to the presence of glucose in the growth medium. We have analysed the mechanism by which glucose exerts its inhibitory effect on bgl expression. RESULTS: Our studies show that initiation of transcription from the bgl promoter is only marginally sensitive to glucose. Instead, glucose exerts a more significant inhibition on the elongation of transcription beyond the rho-independent terminator present within the leader sequence. Transcriptional analyses using plasmids that carry mutations in bglG or within the terminator, suggest that the target for glucose-mediated repression is the anti-terminator protein, BglG. Introduction of multiple copies of bglG or the presence of mutations that inhibit its phosphorylation by Enzyme IIBgl (BglF), result in loss of glucose repression. Studies using crp, cya and crr strains show that both CRP-cAMP and the Enzyme IIAGlc (EIIAGlc) are involved in the regulation. Although transcription initiation is normal in a crp, cya double mutant, no detectable transcription is seen downstream of the terminator, which is restored by a mutation within the terminator. Transcription past the terminator is also partly restored by the addition of exogenous cAMP to glucose-grown cultures of a crp+ strain. Glucose repression is lost in the crr mutant strain. CONCLUSIONS: The results summarized above indicate that glucose repression in the bgl operon is mediated at the level of transcription anti-termination, and glucose affects the activity of BglG by altering its phosphorylation by BglF. The CRP-cAMP complex is also involved in this regulation. The results using the crr mutant suggest a negative role for EIIAGlc in the catabolite repression of the bgl genes.

Bacterial Proteins↗