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Biomedical subjects

D Nag

Publications and source records attributed to D Nag.

At least 19 recordsLinked to original sources
PubMed2004

Neutrophil-free radical generation and enzymatic antioxidants in migraine patients.

The present study was undertaken to elucidate the role of circulating neutrophils if any in oxidative stress in migraine by evaluating free radical generation and activities of enzymatic antioxidants in the blood in 55 patients with migraine and 60 healthy controls. Free radical generation was assessed by flow cytometry, while activity of catalase, superoxide dismutase (SOD) and glutathione peroxidase (GPx) was estimated in blood polymorphonuclear neutrophils (PMNs) by standard procedures. Platelet SOD was also measured. No significant change was found in free radical generation and in the activity of catalase, SOD and GPx in migraine patients. Univariate analysis of PMN catalase level revealed that migraineurs with a positive family history had significantly lower catalase activity compared with those with a negative family history. No correlation was found in the activity of antioxidant enzymes with age, duration of disease, time since last attack and headache index. The platelet SOD also did not show any significant change in patients of migraine without aura. Platelet aggregation in the presence or absence of PMNs was also not altered significantly. Thus the findings of the present study suggest that neutrophils are not the cause of oxidative stress observed in migraine patients.

Adult↗
PubMed2003

Platelet 3H ketanserin binding in tension-type headache.

OBJECTIVE: The present study was undertaken to investigate the alterations in platelet 5-HT2 receptor binding in patients with tension-type headache. BACKGROUND: Serotonin (5-HT) has an important but complex role in pain modulation. The involvement of serotonin in tension-type headache has been investigated by studying serotonin in peripheral blood, but results have been inconclusive. There are, however, only a few investigations in which the status of platelet serotonin transporters has been studied by 3H imipramine and 3H paroxetine. The present study was undertaken to investigate alterations in platelet 5-HT2A receptors using 3H ketanserin as a ligand. METHODS: Platelet 3H ketanserin binding was studied in 14 patients with tension-type headache and in 15 healthy controls. The binding characteristics, equilibrium dissociation constant and maximal number of binding sites were determined by Scatchard analysis. RESULTS: There was no change in the equilibrium dissociation constant in the patients with headache as compared to the control group, but subgroup analysis revealed that patients with tension-type headache with a headache index of less than 360 had a significantly lower equilibrium dissociation constant as compared to those with a headache index of more than 360; there was a significant correlation between the equilibrium dissociation constant and the headache index. A significant decrease was observed in the maximal number of binding sites in tension-type headache. No correlation was observed between the maximal number of binding sites and age, duration of illness, or headache intensity. CONCLUSIONS: The findings of the present study show that there is a decrease in the number of binding sites of 5-HT2A receptors in some patients with tension-type headache, suggesting postsynaptic serotonergic dysfunction and the involvement of serotonin in that group.

Binding Sites↗
PubMed2002

A study on nitric oxide, beta-adrenergic receptors and antioxidant status in the polymorphonuclear leukocytes from the patients of depression.

BACKGROUND: alterations in the polymorphonuclear leukocyte (PMNs) receptors, second messenger system and in their responses have been found associated with depression. Recently role of tetrahydrobiopterin and nitric oxide has also been reported in the depressive disorders. It was therefore considered worthwhile to investigate the NOS activity in the PMNs, which like neurons, also express neuronal NOS (nNOS), antioxidant enzyme levels [superoxide dismutase (SOD), catalase and glutathione peroxidase (Gpx)] and beta-adrenergic receptors in the patients of depression. METHODS: patients were diagnosed according to the DSM-IV and were medication free, while healthy age-matched controls were also included in the study to estimate nitrite content, beta-adrenergic receptors and antioxidant enzymes in the PMNs according to the standard methodologies. RESULTS: an analysis of 66 cases of depression and 114 controls revealed 73% decrease in nitrite content and 71% decrease in beta-adrenergic receptor binding in the patients as compared to the healthy controls. However, activities of SOD, catalase and Gpx were not significantly altered in the patients. CONCLUSION: the results of the present study for the first time indicate alterations the NOS activity in PMNs obtained form the patients of affective disorders.

Adolescent↗
PubMed2001

Nitrite content and antioxidant enzyme levels in the blood of schizophrenia patients.

RATIONALE: Recent studies have suggested augmentation in the inflammatory response as well as involvement of nitric oxide (NO) in mood disorders. Polymorphonuclear leukocytes (PMN), NO and free radicals have been associated with inflammatory response; however, the status of NO in the PMN has not been investigated so far in schizophrenia patients. OBJECTIVES: The present study was undertaken to investigate levels of nitrite (a metabolite of NO), malonaldehyde (MDA, lipid peroxidation product) and antioxidant enzymes such as superoxide dismutase (SOD), catalase and glutathione peroxidase (Gpx) in the PMN of schizophrenia patients. METHODS: Patients with schizophrenia (n=62) were diagnosed according to DSM-IV and were free of anti-psychotic medications/ECT for at least 3 months. Mean age of the patients was 29.06+/-1.17 years, with a male to female ratio of 4:1, and mean duration of illness was 3.7+/-0.6 years. The control group consisted of 82 healthy subjects with a mean age of 37.0+/-1.26 and a male to female ratio of 5:1. PMN were isolated from the blood. Nitrite, MDA and antioxidant enzymes were estimated by standard biochemical techniques in the PMN of normal healthy controls and schizophrenia patients. Platelet and plasma nitrite levels were also estimated in controls and schizophrenia patients. RESULTS: Nitrite content in the PMN was reduced to 68%, while plasma and platelet nitrite content in schizophrenia patients was not significantly changed in comparison to controls. Malonaldehyde (MDA) content in PMN was significantly augmented in schizophrenia patients but activity of SOD, catalase and Gpx remain unaltered. CONCLUSION: Results obtained indicate a significant decrease in NO synthesis and an increase in MDA in the PMN of schizophrenia patients, while antioxidant enzyme activities were not altered in the PMN of schizophrenia patients. This suggests that the decrease in PMN NO synthesis by PMN might lead to oxidative stress in schizophrenia patients.

Adolescent↗
PubMed2001

Platelet 3H ketanserin binding in migraine.

Platelet 3H ketanserin binding was studied in 33 patients of migraine and 30 healthy controls. The binding characteristics: equilibrium dissociation constant (Kd) and maximal number of binding sites (Bmax) determined by Scatchard analysis revealed a significant decrease in Kd and no change in Bmax in migraine cases. No correlation was observed between the Kd and Bmax with the clinical features of migraine. The findings of the present study show that there is a decreased affinity of platelet 5-HT2 receptors in migraine.

Adult↗
PubMed2001

Blood nitrite levels in patients with migraine during headache-free period.

OBJECTIVE: To investigate blood nitrite levels after migraine attacks and to assess whether or not the change in nitric oxide levels observed during acute migraine persist after the attacks. BACKGROUND: Involvement of nitric oxide has been suggested in the initiation of acute migraine. Recent studies have shown alteration in the platelet response and platelet nitrite levels during migraine attacks. METHODS: Patients with migraine with aura and patients without aura were included in the study. The study was conducted on 50 patients with migraine and 90 healthy controls. Blood from the patients was collected at least 7 +/- 0.8 days after the last attack of migraine. Nitrite levels in the polymorphonuclear leukocytes, platelets, and plasma were estimated. Platelet aggregation response in some of these patients was also studied. RESULTS: No significant change in the polymorphonuclear leukocyte, platelet, and plasma nitrite levels in patients with migraine compared to controls was observed. Patients with migraine with aura had significantly lower polymorphonuclear leukocyte nitrite levels compared to those without aura (P<.05). In addition, no significant difference in the adenosine diphosphate-induced platelet aggregation was observed in the migraineurs compared to the healthy controls. CONCLUSIONS: Results obtained indicate that the platelet aggregation response and the blood nitrite levels were not altered significantly after an attack in the patients with migraine.

Adult↗
PubMed2000

Antioxidant levels in the rat brain after nitric oxide synthase inhibition: a preliminary report.

Protective effects of NOS inhibitors and free radical scavengers in cerebral ischemia are well documented. The present study was undertaken to determine the possible effects of NOS inhibition on brain antioxidants. Levels of both enzymatic [glutathione peroxidase (GPx), catalase and superoxide dismutase (SOD)] and non-enzymatic [reduced glutathione (GSH)] antioxidants following nitric oxide synthase (NOS) inhibition by N(G)-nitro-L-arginine methyl ester (L-NAME), D-NAME or 7-nitroindazole (7-NI) have been investigated. NOS activity and antioxidant levels in the rat cerebellum and medulla were estimated 1 h after treatment with L-NAME (10, 30 and 100 mg/kg, i.p.), D-NAME (100 mg/kg, i.p.) or 7-NI (25 mg/kg, i.p.). L-NAME and 7-NI inhibited NOS activity in a dose-dependent manner. D-NAME also exhibited significant NOS inhibition. The activity of SOD and the GSH level remained unaltered following NOS inhibition. However, L-NAME and D-NAME at 100 mg/kg attenuated GPx activity in the cerebellum, though 7-NI had no effect. L-NAME inhibited catalase activity in medulla only at 30 mg/kg, but had no effect in cerebellum. However, 7-NI (25 mg/kg), D-NAME and L-NAME at 100 mg/kg did not affect catalase activity in the rat brain. Thus, NOS inhibition by the three agents did not have major effects on brain antioxidant levels.

Animals↗
PubMed2000

Gender and epilepsy : a Clinician's experience.

Women in India are greatly discriminated against if they happen to have epilepsy. Engagements are often cancelled. The parents of epileptic girls have to give heavy dowry at the time of marriage, even if the boy is handicapped. As a result, many girls do not disclose their problem before marriage. They take the medicine secretly. Epilepsy may sometimes produce problems during pregnancy and delivery, otherwise epileptic women on anti epileptic drugs, can lead a normal married, professional and social life. The stigma of epilepsy should be done away with, as we enter the 21st century.

Anticonvulsants↗
PubMed1999

Polymorphonuclear leukocyte nitrite content and antioxidant enzymes in Parkinson's disease patients.

OBJECTIVE: The present study was undertaken to evaluate the alteration in the peripheral neuronal nitric oxide synthase (NOS) activity in Parkinson's disease patients. Therefore, basal nitrite content in PMNs, platelets and in the plasma of PD and control Indian population were evaluated. MATERIALS AND METHODS: We estimated nitrite, the nitric oxide (NO) metabolite, in neutrophils (PMNs), platelets and in plasma of control and in L-dopa treated Parkinson's disease (PD) patients. We also measured the activity of catalase, superoxide dismutase (SOD) and glutathione peroxidase (GPx) in the PMNs. RESULTS: We observed a significant increase in the basal nitrite content in PMNs of PD patients without any alteration in the plasma and platelets. Thus, the change was specific to PMNs. Catalase activity was significantly less in the PMNs of PD patients, but SOD and GPx remained unaltered. CONCLUSION: Results obtained in the PD patients exhibit an increase in the NOS activity in PMNs. Thus, involvement of NO is suggested in PD.

Adult↗
PubMed1999

New paradigms for medical decision support and education: the Stanford Health Information Network for Education.

The information needs of physicians are complex and ever increasing in a world of rapidly expanding medical knowledge and a practice environment where physicians are required to know and do more with shrinking resources. Current strategies for providing clinical decision support and continuing medical education have failed, in part, because they have not provided timely, easy access to information that is current, integrated with other information and the physician's workflow, and relevant to specific questions that occur during the patient encounter. Meeting these challenges involves understanding the nature of medical knowledge, the different information needs of physicians, the clinical decision-making process, and the constraints of the physicians work environment, as well as the traditional barriers to physician education. We explore the nature of some of these challenges and propose one solution in the form of a highly integrated web-based technology--The Stanford Health Information Network for Education.

Academic Medical Centers↗
PubMed1999

Evaluation of metronidazole toxicity: a prospective study.

Metronidazole is an antimicrobial, antiprotozoal agent that has been widely used in the treatment of a variety of infections. Some therapeutic indications necessitate prolonged treatment with metronidazole. Peripheral neuropathy is a potential metronidazole-induced toxicity, which has been reported in only a few isolated retrospective studies. This prospective study was designed to determine the toxic profile of metronidazole in patients undergoing long-term treatment with this drug. In the present study, 17 patients of both sexes, aged between 20 and 50 years, with body weights ranging from 46 to 62 kg and who were suffering from various medical ailments were recruited. The patients received 400 mg t.i.d. oral metronidazole in a total dose of 16.8-39.6 g for 2-4 weeks. It was found that patients usually suffered from some of the toxic symptoms of metallic taste, headache and dry mouth and to a lesser extent nausea, glossitis, urticaria, pruritus, urethral burning and dark colored urine. Symptoms were irrespective of sex and directly proportional to duration of therapy. Deep tendon ankle jerks were maximally reduced in four patients and sense of vibration at the level of olecranon and patella was affected in two patients. Distal latency and velocity of the sural and posterior tibial nerves were significantly affected (p < 0.01) compared with control values. These results indicate possible motor-sensory neurotoxicity involving the lower limbs due to long-term metronidazole therapy.

Adult↗
PubMed1998

Intramedullary spinal cysticercosis: response to albendazole: case reports and review of literature.

In India cestode infection 'neurocysticercosis' is the commonest parasitic disease of the central nervous system; it may involve the brain parenchyma, the meninges or ventricles and, infrequently it involves the spinal cord. Involvement of spinal cord has variably been reported to be 1-5%. We report two cases of intramedullary spinal neurocysticercosis, which is a rare disease.

Albendazole↗
PubMed1998

Single enhancing CT lesions in Indian patients with seizures: clinical and radiological evaluation and follow-up.

Single enhancing lesions in cranial computed tomography (CT) are the commonest imaging abnormality in Indian patients with seizures. We studied 101 such patients who had single CT lesions at least 6 months prior to enrollment in the study. A repeat CT scan was performed in each case after enrollment in the study. The majority of patients were below 10 years of age. Simple partial tonic/ clonic convulsions were the commonest type of seizure encountered irrespective of location of the CT lesion. The parietal lobe was the commonest site of location. All patients with a parasagittal location of the lesion had Todd's palsy. All patients had an acute seizure episode or a cluster of seizures (multiple within 24 h). Ten patients presented with simple partial status epilepticus as first seizure. The initial non-contrast enhanced CT scan revealed focal hypodensity due to cerebral oedema in 49 patients. In an additional 17 patients we observed complete cysticercal larvae (cyst with scolex). In the rest of the patients, plain CT scans were normal. After contrast administration, the majority revealed a ring/disc enhancing lesion; half of them had an enhancing eccentric dot representing a scolex. Forty-seven patients received definitive treatment in the form of either albendazole or antituberculous drugs along with antiepileptic drugs. The rest of the patients received only antiepileptic monotherapy. The majority of patients, irrespective of type of treatment, showed either regression or disappearance of lesions. Similar incidences of seizure recurrences were noted in patients who themselves discontinued antiepileptic therapy, in comparison to those who continued with antiepileptic drugs. Only nine out of 16 patients with persistent CT lesions experienced recurrence of seizures. In the majority, persisting lesions remained unchanged to a ring form; in the remaining patients ring lesions transformed into disc-enhancing lesions, or became calcified. In conclusion, these CT lesions are benign in nature and tend to disappear or regress spontaneously. The associated seizure disorder is also benign and easily controlled. Probably, a shorter duration of antiepileptic therapy would suffice. Neither albendazole nor antituberculous therapy was helpful in modifying the natural course of the CT lesion or associated seizure disorder.

Adolescent↗
PubMed1998

A randomized double-blind controlled study of nimodipine in acute cerebral ischemic stroke.

A randomized placebo controlled double-blind clinical trial of nimodipine was conducted in 31 patients of acute cerebral infarction. Nimodipine was administered in dosage of 120 mg/day for 28 days. Treatment was begun within 48 hours of ischemic stroke. Diagnosis was confirmed by computed tomographic (CT) scan. Similar number of patients (control) received placebo. Neurological assessment was done at the time of entry into the trial, and after 4 weeks, by using Mathew's scale. After four weeks of treatment with nimodipine or placebo, Mathew's scale score improved significantly (< 0.001) in both groups, but difference in mean score between two groups was insignificant (> 0.05). However, significant difference (< 0.05) was noted in relative change in neurological deficit (mean X-value) of two groups. The nimodipine group had higher value in scores on Mathew's scale. No adverse reaction, was observed in either group. The study suggests a beneficial a effect of nimodipine in acute cerebral ischaemia.

Adult↗
PubMed1998

A comparative evaluation of pharmacokinetics of conventional and slow-release carbamazepine formulation in newly treated patients of epilepsy: a random evaluation.

Study was conducted to compare the pharmacokinetic profile of conventional and slow-release carbamazepine formulations in Indian epileptic patients. Twenty consecutive untreated patients of partial seizures were randomly assigned to receive either conventional carbamazepine (200 mg thrice a day) or slow-release carbamazepine formulation (200 mg thrice a day), 10 patients in each group. The serum carbamazepine concentrations were measured on 10th day and 20th day of treatment. The blood samples were collected before the morning dose. In the conventional treatment group five patients experienced side effects as compared to two in the slow-release group. On 10th day mean serum carbamazepine levels were significantly higher in conventional group (8.27 +/- 1.39 micrograms/ml) in comparison to slow release group (4.28 +/- 3.89 micrograms/ml). The difference was statistically significant (p < 0.05). On 20th day carbamazepine levels fell significantly in conventional group only (8.27 +/- 1.39 micrograms/ml to 5.76 +/- 2.32 micrograms/ml, p < 0.05). At this stage the difference in mean carbamazepine levels of two groups became insignificant (p < 0.05). In conclusion, controlled release formulations provide more steady serum concentrations of carbamazepine along with better tolerability.

Adolescent↗
PubMed1997

Health service indicators for radiology departments: how meaningful are they?

The Health Service Indicator (HSI) for Radiology Services in the UK is represented by a cost per case figure based on annual expenditure and workloads in individual departments. These show significant variations betweeen departments for a number of predictable reasons. Detailed analysis shows good correlation between population-based radiology costs and workloads and that departments with low cost per case values have above average workloads. The usefulness of the HSI cost per case is limited to identification of departments with unduly high or low values, thus allowing such departments to critically appraise their staffing and workload levels. Taken at face value, they can easily be misinterpreted as a measure of cost-effectiveness.

Hospital Costs↗
PubMed1997

The Stanford Health Information Network for Education: integrated information for decision making and learning.

Although multiple decision support systems have been built for physicians, efficient delivery of valid and complete medical knowledge remains an elusive goal. In this paper we describe a new project, the Stanford Health Information Network for Education (SHINE). SHINE unifies core medical resources in an intuitive interface to support clinical decision making. Included in the description is a novel paradigm for continuing medical education (CME).

California↗