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Biomedical subjects

N Mishra

Publications and source records attributed to N Mishra.

At least 37 records · Page 2Linked to original sources
PubMed1998

Clinical expression of autoimmune diseases in older adults.

Aging modifies the clinical presentation and course of autoimmune disorders. In the older person who carries a complement of predisposing genes, environmental factors may alter a senescent immune system and trigger the onset of autoimmunity. In this article about autoimmune diseases of the older adult, the authors discuss the epidemiology, clinical presentations, laboratory and radiographic findings, and management of systemic lupus erythematosus, primary Sjogren's syndrome, and idiopathic inflammatory myopathies.

Aged↗
PubMed1997

MR evaluation of CSF fistulae.

PURPOSE: To evaluate the role of MR imaging in the localisation of cerebrospinal fluid (CSF) fistulae. MATERIAL AND METHODS: A total of 36 consecutive unselected patients with either clinically proven CSF leakage (n=26) or suspected CSF fistula (n=10) were prospectively evaluated by MR. All MR examinations included fast spin-echo T2-weighted images in the 3 orthogonal planes. Thin-section CT was performed following equivocal or negative MR examination. MR and CT findings were correlated with surgical results in 33 patients. RESULTS: CSF fistula was visualised as a dural-bone defect with hyperintense fluid signal continuous with that in the basal cisterns on T2-weighted images. MR was positive in 26 cases, in 24 of which the fistula was confirmed surgically. In 2 patients the CSF leakage was directly demonstrated on MR. MR sensitivity of 80% compared favourably with the reported 46-81% of CT cisternography (CTC). No significant difference in MR sensitivity in detecting CSF fistula was found between active and inactive leaks CONCLUSION: MR is recommended as the first investigation for detecting a CSF fistula owing to its efficacy and to its freedom from the potential complications encountered with CTC.

Adolescent↗
PubMed1996

Cardiovascular response to orthostatic stress following cold challenge in diabetics.

Cardiovascular responses to cold pressor test (CPT) followed by orthostatic stress were investigated in diabetics and in control subjects. The test was performed by immersing the left hand (up to wrist joint) in water at 8 degrees C for 2 minutes. The blood pressure (BP) and heart rate (HR) were recorded immediately after removal of hand from water in recumbent state and then in erect posture. The orthostatic stress (without cold exposure) caused postural hypotension in diabetics, while in control subjects BP (both systolic and diastolic) increased on attaining erect posture. CPT alone increased HR, systolic blood pressure (SBP) and diastolic blood pressure (DBP) in control as well as in diabetics. In control subjects when CPT was followed by orthostatic stress, a marked statistically significant further increase in HR but fall in SBP was observed, though the increase in DBP was not significant. On the other hand statistically significant increase in HR, and decrease in SBP, DBP were observed in diabetic subjects. These impairments in cardiovascular responses are confirmative of autonomic neuropathy in diabetic subjects.

Adult↗
PubMed1996

Comparison of single breath and steady state methods for measurement of lung transfer factor for CO in normal subjects and smokers.

Pulmonary diffusing capacity (lung transfer factor for carbon monoxide) has been assessed by the single breath (TLCOSB) and steady state (TLCOSS) techniques in well matched 90 females, 31 non-smoker and 29 smoker males, 18-50 years of age. Both TLCOSB and TLCOSS are significantly lower in females compared to non-smoker males (P < 0.001). Tobacco smoking statistically significantly reduces TLCOSB as well as TLCOSS in smokers as compared to non-smokers. There is a statistically significant correlation of age with TLCOSS and TLCOSB in all the three groups (r = -0.702, -0.360 and 0.300 for TLCOSB and r = -0.481, -0.355 and 0.380 for TLCOSS in non-smoker males, smoker males and females respectively). TLCOSB is 30.43 +/- 4.89, 27.29 +/- 4.54 and 26.13 +/- 3.60 ml/mmHg/min, while TLCOSS is 19.47 +/- 5.26, 16.69 +/- 3.27 and 18.24 +/- 3.78 ml/mm/Hg/min in non-smoker males, smoker males and females respectively. A fairly good correlation between the TLCOSB and TLCOSS in male, both non-smoker and smoker, as well as the female subjects was observed. TLCOSS is lower than TLCOSB in all the three groups. Even in smokers of moderate intensity both of these tests are influenced to a nearly similar extent.

Adolescent↗
PubMed1994

A structure activity relationship study on 1-isopropylamino-3-(2'-substituted naphthoxy)-propan-2-ois analogs.

The structure activity relationship of 1-isopropylamino-3-(2'-substituted naphthoxy) propan-2-ois analogs, which are beta-adrenergic blocking drugs, is discussed. The blocking activity of these compounds is found to be dominantly controlled by electronic and steric factors. Significant correlations have been obtained between the blocking activity and negentropy, equalized eletronegativity and partial charge.

Adrenergic beta-Antagonists↗
PubMed1994

Dynamics of Met5- and Leu5-enkephalin and their receptor binding activity in relation to morphine.

A complete normal coordinate analysis of Met5- and Leu5-enkephalins using Wilson's GF matrix method and Urey Bradley force field has been carried out to understand the dynamical behaviour of enkephalins. In addition, the charge distributions on different atoms of the two enkephalins and morphine using CNDO/2 method are also reported. The similarity in the charge distribution on the part of these two molecules is indicative of the possible interactions at the same receptor site as that of morphine and its derivatives. Apart from the topographical features and charge distribution, binding onto receptor site is not a static but a dynamic process and low frequency modes must play an important role in the recognition process. The significance of the out-of-plane amide VII band and other skeletal modes as characteristic of conformational states of Met5- and Leu5-enkephalins are discussed.

Enkephalin, Leucine↗
PubMed1991

Extracranial carotid artery aneurysms following accidental injury: ten years experience.

Extracranial carotid artery aneurysms secondary to accidental injury are rare. We have seen eight lesions of this type in the last 10 years. The aneurysm was produced by blunt trauma in four patients, penetrating shrapnel injury in two, stabbing and electrical injury in one each. The left side was involved in seven patients. The internal and common carotid artery were each involved in four patients and the lesion was unilocular in five. These lesions often produce non-specific symptoms and may mimic neoplastic or inflammatory masses: a mistaken diagnosis of tonsillar abscess in one patient resulted in incision and drainage before an intravenous digital subtraction angiogram (IV-DSA) correctly identified the abnormality. IV-DSA is ideal for pre-operative assessment of these patients. Awareness of these lesions is essential since definitive surgical repair is possible. All patients in the present study underwent successful surgical repair.

Adolescent↗
PubMed1991

An experimental evaluation of possible teratogenic potential in Boerhaavia diffusa in Albino rats.

The present study was undertaken to evaluate any possibility of teratogenic effects in Boerhaavia diffusa (Punarnava), a widely used herbal medicine for renal and urinary tract diseases by Ayurvedic physicians in India. The ethanolic extract of Boerhaavia diffusa (BDE) was administered daily in a dose of 250 mg/kg, body weight p.o., to pregnant albino female rats during the entire period of gestation. BDE was found to be devoid of any teratogenic effect as litter size and survival rate of foetuses were the same as for the normal control group and no foetal anomaly could be detected.

Animals↗
PubMed1991

Effect of exercise on lung transfer factor for CO in smokers.

The lung transfer factor for carbon monoxide was studied in 24 apparently healthy smokers and in 24 well-matched non-smokers at rest and during exercise. Single-breath and steady state (TLcoss) transfer factors for carbon monoxide, the Krogh constant, and the capillary blood volume were significantly lower in smokers. Exercise increased minute ventilation to a similar extent in both groups, but significantly lower values of TLcoss were measured in smokers than in non-smokers during mild and moderate grades of exercise (p less than 0.001). This difference in TLcoss may be attributed either to the difference in capillary blood volume or to increased inhomogeneities with regard to alveolar ventilation and perfusion due to airway damages in smokers, or to both factors.

Adult↗
PubMed1991

Lung transfer components in hyperthyroidism.

Pulmonary functions were studied in twenty hyperthyroid non smoker patients. Their FVC, PEFR and MVV were significantly lowered while FEV1/FVC% and EFR25-75% were normal. Amongst the diffusion functions, Tlco, Dm and VA were reduced and VC increased, though these changes were not statistically significant. After the achievement of euthyroid state, statistically significant increase was seen in FVC, PEFR, MVV, Tlco120, Dm and VA with significant decrease in Vc from the basal levels. FEV1/FVC% and EFR25-75% were not affected. These observations suggest that the principal abnormalities in pulmonary functions in the hyperthyroid state are increased pulmonary capillary blood volume and respiratory myopathy, which are reversed as euthyroid state is achieved.

Adult↗
PubMed1991

Effect of salbutamol on pulmonary diffusion functions in asymptomatic smokers.

Pulmonary functions including transfer factor for CO and its components (TIco, Dm, Vc) were studied in 45 asymptomatic subjects (25 smokers, 20 non smokers) using single breath technique. Ventilatory functions of smokers were significantly reduced; these improved significantly after salbutamol inhalation but most still remained lower than in non smokers. VA and Dm were marginally higher while Vc was significantly reduced in smokers. Their TIco1(20) was influenced only insignificantly. However, after salbutamol, both Dm and Vc were significantly lowered, resulting in further reduction (p 0.01) of TIco120 in smokers. The effect of salbutamol in non smokers was insignificant.

Adult↗
PubMed1990

Evidence for the inhibitory effect of 5-hydroxytryptamine at central and peripheral sites on ovulation in rabbits.

1. The effect of 5-hydroxytryptamine (5-HT) has been investigated on ovulation per se as well as on induced ovulation in rabbits. 2. 5-HT administered intracerebroventricularly (i.c.v.) did not induce ovulation per se. 3. The ovulation was induced by coitus, subcutaneous administration of progesterone and intravenous administration of cupric acetate. 4. Postcoital and progesterone induced ovulation was found to be blocked by i.c.v. administered 5-HT. 5. Cupric acetate induced ovulation was, however, not found to be blocked by i.c.v. administered 5-HT. 6. Intraperitoneal administration of 5-HT was found to block cupric acetate induced ovulation. 7. It is concluded that 5-HT exerts an inhibitory control over ovulation by acting at central as well as at peripheral sites in rabbits.

Animals↗
PubMed1990

Effect of cold challenge on alveolar capillary blood volume in normal individuals.

The effect of immersion of both the hands and the feet in water at 10 degrees C on lung transfer factor for carbon monoxide (Tlco) and on pulmonary capillary blood volume (Vc) was investigated in 20 normal young adult males immediately, 60 min and 120 min after the end of the cold challenge. Vc was significantly reduced immediately and the reduction was aggravated at 60 min. Tlco was significantly reduced only at 60 min. All the values returned to baseline at 120 min. It is concluded that the cold-induced changes in Tlco and Vc are physiological responses and not unique to patients with Raynaud's phenomenon as suggested by some workers.

Adult↗
PubMed1990

Diurnal variations in lung transfer factor and its components.

Serial measurements of transfer factor of lung and its constituent components along with FVC and EFR25-75% were undertaken in 20 healthy nonsmoker adult males thrice on the same day. All the lung transfer components decreased as the day advanced, though reduction was statistically significant for Tlco and VA only. These changes were present in association with reduction in FVC and EFR25.75% indicating that patency of airways influences diffusion function of lung. Variations during the day are less than 7.4% and are hence unlikely to influence their diagnostic value, but serial estimation of these functions should preferably be carried out at the same time specially in the morning when these values are maximum.

Adult↗
PubMed1986

Nervous system in Olveria indica, a rumen paramphistome (Digenea) of bovines, as revealed by non-specific esterase staining.

On the basis of esterase localization the complete nervous system has been visualized in Olveria indica Thapar & Simha, 1945, a paramphistome from the rumen of cattle, recorded for the first time from the north-east region of India. The basic number of posterior longitudinal nerves (i.e., 3 pairs) is the same as in other paramphistomes; four pairs of anterior longitudinal nerves are present, there being an extra pair of pharyngeal nerves. Conspicuous differences in the innervation patterns were observed, mainly in the innervation of the genital atrial region and acetabulum. The presence of prominent longitudinal connections, joining the anterior and posterior dorsal nerves and the anterior and posterior ventral nerves on either side, is a feature not hitherto found in other paramphistome species. The details of the course of all the nerves and their branches are discussed.

Animals↗
PubMed1985

A comparison of alpha 2-adrenoceptor regulation in brain and platelets.

Functional responses and alpha 2-adrenoceptor radioligand binding were studied in brain and platelets of rabbits under a variety of circumstances. The effects of oestrogen treatment and maturation were studied in female rabbits and of aging and amitriptyline treatment in male rabbits. No correlation was found between changes in brain and platelets either in response or alpha 2-adrenoceptor ligand binding under any of the conditions examined.

Aging↗
PubMed1985

The effects of sexual maturation on alpha-adrenoceptors in female rabbits.

alpha-Adrenoceptor number and function were examined in brain, platelets, and other peripheral tissues of young (2-3 months) and mature (6-8 months) non pregnant female rabbits. alpha1-Adrenoceptor number was significantly higher in forebrain, hindbrain, spleen and heart of mature rabbits. alpha2-Adrenoceptor number, on the other hand, was found to be significantly lower in platelets, forebrain and spleen but not changed in hindbrain and kidney of mature animals compared to young females. There was a significant reduction in platelet aggregation with maturation. However, no change in in vivo pressor or depressor responses to alpha-adrenoceptor agonists was observed in vivo.

Adrenergic alpha-Agonists↗