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Biomedical subjects

N Kapur

Publications and source records attributed to N Kapur.

82 records · Page 5Linked to original sources
PubMed1982

Myocardial cell damage and cardiovascular changes due to i.v. infusion of adrenochrome in rats.

In vivo effects of adrenochrome (1-32 mg/kg), an oxidation product of catecholamines, on the heart ultrastructure, ECG and blood pressure were studied in rats over a period of 60 min following a single i.v. injection of the drug. One milligram of the drug had no influence on the myocardium or the cardiovascular system, whereas maximum changes in these parameters were recorded at 32 mg/kg of adrenochrome. The maximum structural damage, reached within 5-10 min, included marked swelling of mitochondria and sarcotubular system, intracellular and perinuclear oedema, hypercontraction of myofibrils and partial separation of the intercalated disc. Ultrastructural changes in the myocardium due to 4 and 8 mg of adrenochrome were not accompanied by any cardiovascular effects and the changes were fully reversed within 60 min of the injection of the drug. However, at 16 and 32 mg/kg of adrenochrome both heart rate and blood pressure were depressed within 5 min of drug administration. At these concentrations of adrenochrome arrhythmias, mainly due to premature ventricular contractions, were also noticed. Ultrastructural and cardiovascular changes seen at these higher concentrations of adrenochrome showed only a partial recovery. The data indicates that adrenochrome-induced ultrastructural changes in the heart are due to a direct myocardial effect of the drug which may not involve haemodynamic changes and the latter are most probably a consequence of this effect. However, the present study has not been able to rule out direct vascular effects at higher concentrations of adrenochrome.

Adrenochrome↗
PubMed1980

Recognition of word associates in semantic paralexia.

This study examines the processing of word associates by a patient who makes semantic paralexic responses ir oral reading. His ability to extract semantic features from printed words was assessed using a task which involved the recognition of specific associates of printed words. He could recognize as many associate words as normal control patients, but was more likely to make a positive response to stimulus words unrelated to the target item. There was also a tendency to more readily accept same-category associates as being related to target words. It is suggested that semantic paralexic patients sometimes make inadequate 'checks' on related words which are activated when printed words are perceived, and possible retraining procedures are suggested which may improve their checking strategies.

Adult↗
PubMed1980

Confabulation and frontal lobe dysfunction.

A patient is reported who displayed marked confabulation after frontal lobe damage, and whose pattern of performance on memory tests was not typically amnesic. He initially displayed both "fantastic" and "momentary" confabulation, but several months later showed only "momentary" confabulation, which was apparent on direct questioning. This change in type of confabulation was paralleled by improved performance on frontal lobe tests, although his overall pattern of performance on memory tests was unchanged. It is suggested that severity of frontal lobe dysfunction determines the type of confabulation displayed.

Frontal Lobe↗
PubMed1978

Recognition reading in paralexia.

Reading aloud and recognition reading were examined in a paralexic patient. Certainty ratings made by the patient during oral reading indicated that he was usually unaware of paralexic errors which he made. In an auditory recognition reading task for words previously misread, the patient still performed poorly, often chosing his paralexic response as the correct alternative. Possible mechanisms underlying paralexia are discussed in the light of these findings.

Adult↗
PubMed1975

Retraining of dysgraphia - a case study.

A patient with dysgraphia resulting from a gunshot wound of the brain is presented. Analysis of the functional status of component operations involved in the skill of writing is described. A retraining scheme based on this analysis brought about a significant improvement in the patient's handwriting.

Adult↗
PubMedDate not supplied

How can be best explain retrograde amnesia in human memory disorder?

I firstly consider general issues relating to our attempts to understand retrograde amnesia. Three main hypotheses are reviewed that have been proposed to account for retrograde amnesia. A theory is outlined to explain the dense autobiographical amnesia that is a focal phenomenon in some cases of severe head injury. This theory postulates that autobiographical retrieval requires the activation of a distributed network of cognitive operations, and that autobiographical amnesia results from the occurrence of multiple areas of pathology, distributed over both space and time.

Age Factors↗
PubMedDate not supplied

Emotional, cognitive, and behavioral characteristics of medical outpatients: a preliminary analysis.

The authors examined the relationship among emotional, cognitive, and behavioral factors in 65 new outpatients attending neurology and cardiology clinics. The patients completed the Hospital Anxiety and Depression Scale, the Illness Perception Questionnaire, the Somatosensory Amplification Scale, the Private Body Consciousness Scale, and the Health Anxiety Questionnaire. A principal component factor analysis revealed two factors, somatosensory amplification/anxiety and depression/pessimism, that together accounted for 44% of the variance. The factors the authors identified may be useful as a basis for understanding different patterns of illness behavior. The use of these factors may help to rationalize and refine the large number of existing measures and simplify the assessment process, as well as contributing to the development of treatment interventions.

Adolescent↗
PubMedDate not supplied

Job satisfaction and psychological morbidity in medical house officers.

The aim of this study was to examine levels of job satisfaction and psychological morbidity in preregistration house physicians working partial shift rotas, full shift rotas, or traditional on-call rotas. The study was carried out at two teaching hospitals in one city, and consisted of a prospective within-subject crossover study at hospital A and a parallel simple descriptive study at hospital B. Sixty preregistration house physicians were included in the study. At hospital A the house officers worked shifts for part of their post and traditional on-call rotas for the remainder. At hospital B the house officers worked a modified on-call rota throughout. The outcome measures used were the 30 item General Health Questionnaire and a self-report job satisfaction scale. Measures were administered at hospital A towards the end of each distinct rota period (on-call or shift) and simultaneously administered at hospital B. Results showed that full shifts were associated with greater psychological morbidity and lower job satisfaction than traditional on-call rotas. Partial shifts were rated more favourably but were nonetheless unpopular. There was a marked difference between hospitals. It would seem that some 'new deal' rotas may increase psychological morbidity and reduce job satisfaction.

Adult↗