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Biomedical subjects

R Tandon

Publications and source records attributed to R Tandon.

At least 199 records · Page 11Linked to original sources
PubMed1989

Coexisting hereditary methaemoglobinaemia and heterozygous beta-thalassaemia.

Cyanosis was noted within a few weeks after birth in two sisters. On investigation the cause of cyanosis was found to be congenital methaemoglobinaemia due to NADH diaphorase deficiency. Heterozygous beta-thalassaemia was present as an additional incidental finding in one of the sisters, but did not contribute to the symptoms, thus showing that the two diseases, when coexistent, do not pose additional haematological problems. However, it is possible that the beta-thalassaemia counteracts the tendency to compensatory erythrocytosis induced by methaemoglobinaemia.

Child, Preschool↗
PubMed1989

Carcinoid syndrome without liver metastasis.

The carcinoid syndrome generally occurs due to metastasis of a carcinoid tumour in the liver. A patient is presented who had carcinoid syndrome due to abdominal disease without hepatic metastasis.

Adenocarcinoma↗
PubMed1989

HLA-DR/DQ antigens and reactivity to B cell alloantigen D8/17 in Indian patients with rheumatic heart disease.

D8/17, a B cell alloantigen, and its occurrence with DR/DQ antigens was examined in 54 patients with rheumatic heart disease and matched North Indian controls. Thirty-four patients (62.9%) carried D8/17 as compared with a frequency of 12.5% in controls (chi 2 by Yates', 18.75; p less than 0.0001). A marginally increased frequency of human leukocyte antigen (HLA)-DR3 (44.2% vs. 28.8%) and a significantly reduced frequency of HLA-DR2 (21.1% vs. 46.6%; p less than 0.005) was observed in patients as compared with controls. However, the most significant positive association was observed with HLA-DQw2 (63.4% in patients and 31.5% in controls; chi 2 by Yates', 9.85; p less than 0.005). The DQw2 association was significant only in the D8/17-positive patients. These observations suggest that the disease susceptibility gene in rheumatic heart disease may be nearer to the HLA-DQ locus than to the HLA-DR.

Antigens, Differentiation, B-Lymphocyte↗
PubMed1989

Cholinergic syndrome following anticholinergic withdrawal in a schizophrenic patient abusing marijuana.

A 27-year-old neuroleptic-stabilised schizophrenic patient presented with a three-day history of psychomotor retardation, disturbed sleep, and social and emotional withdrawal following reduction of his anticholinergic dosage; his symptoms had intensified after an increase in neuroleptic dosage, based on a diagnosis of psychotic decompensation. Recognition of a cholinergic syndrome and institution of appropriate anticholinergic treatment resulted in rapid improvement. The clinical distinction between a cholinergic overdrive state and schizophrenic exacerbation, while sometimes difficult, can be critical in selecting appropriate management.

Adult↗
PubMed1989

Dopaminergic activity of the antimuscarinic antiparkinsonian agents.

The antimuscarinic antiparkinsonian agents are widely used in psychiatric practice to reduce the extrapyramidal motor symptoms caused by the neuroleptic antipsychotic medications. Although the antimuscarinic antiparkinsonian agents are effective in reducing extrapyramidal symptoms, their use in conjunction with neuroleptic treatment of psychosis has been reported to antagonize the therapeutic effects of the neuroleptic; there are also several reports of the antimuscarinic antiparkinsonian agents variously causing psychotic syndromes, mood elevating and stimulant effects, stereotypy, dyskinesia, behavioral agitation, and drug dependence in both psychiatric and normal populations. These drug-related phenomena are generally attributed to the antimuscarinic properties of these agents. A large body of data, however, has shown that the antimuscarinic antiparkinsonian agents also function as potent, indirect dopamine-agonists. Benztropine, the most widely prescribed of these medications, is one of the most potent known inhibitors of presynaptic dopamine reuptake. These antiparkinsonian agents also have potent agonist activity at the noradrenergic synapse, as well as minor activity at the serotonergic synapse. This paper reviews neuropharmacologic evidence suggesting that significant neurophysiologic effects can result from the dopaminergic--and possibly noradrenergic--activity of the antimuscarinic antiparkinsonian agents, similar in some cases to those observed with amphetamine. Greater attention to these properties may aid in interpretation of clinical and research observations involving these so-called "antimuscarinic" agents.

Antiparkinson Agents↗
PubMed1988

Gross and histologic anatomy of total anomalous pulmonary venous connections.

Among 49 heart specimens with total anomalous pulmonary venous connection (TAPVC), obstruction to pulmonary venous flow was present in all 13 cases with TAPVC below the diaphragm and in 53% of 36 cases with TAPVC above the diaphragm. Obstruction was produced by extrinsic pressures on the vein, intrinsic narrowing of the vein, or both. The histology of the narrowed veins was extremely variable, ranging from atrophy of the vein wall to hypertrophy of intima, media-adventitia, or both. Balloon dilation of narrowed veins was performed in 3 cases, without clinical or anatomic evidence of success.

Brachiocephalic Veins↗
PubMed1988

Partial anomalous pulmonary venous drainage and intact atrial septum with mitral stenosis: the paradox of a small shunt.

Clinical, hemodynamic, and angiographic features of 10 patients with partial anomalous pulmonary venous drainage, intact atrial septum, and rheumatic mitral stenosis have been presented. Seventeen patients with this combination of anomalies reported in the literature have also been reviewed. The clinical diagnosis of mitral stenosis was possible in each of our 10 cases. Partial anomalous pulmonary venous drainage and intact atrial septum in addition to mitral stenosis was clinically suspected in only four patients. The findings suggesting additional presence of partial anomalous pulmonary venous drainage and intact atrial septum in a patient with mitral stenosis include: wide variable splitting of the second sound, pulmonary ejection systolic murmur with or without a thrill, and radiological evidence of unilateral increase in pulmonary vascularity or unilateral hilar pulsations. Hemodynamic findings were characterized by a relatively modest left to right shunt (Qp/Qs:2.2 +/- 1.4). Elevated pulmonary vascular resistance was found in the anomalously draining as well as the normally draining lung segments (9.1 +/- 4.9 and 6.5 +/- 3.4 units, respectively, t = 1.32;NS). The mechanism of the unexpected high resistance in the anomalously draining lung segments permitting only a small left to right shunt is discussed.

Adolescent↗
PubMed1988

Collateral arteries arising from the coronary circulation in tetralogy of Fallot.

Semi-selective aortic root and some selective coronary angiographic studies were performed in 330 patients with tetralogy of Fallot over a period of four years. Collateral vessels arising from the coronary arteries were found in 11 cases and a direct communication between the coronary artery and pulmonary arteries in one case (3.6%). Electrocardiographic features of myocardial ischaemia were not present in any patient. It is important to localize the collateral arteries since coronary steal and myocardial ischaemia have been known to occur in their presence.

Adolescent↗
PubMed1988

Testicular effects of acrylonitrile in mice.

Daily oral administration of acrylonitrile (10 mg/kg body weight) to mice for a period of 60 days caused a significant decrease in the activity of testicular sorbitol dehydrogenase and acid phosphatase, and an increase in that of lactate dehydrogenase and beta-glucuronidase. Histopathological studies revealed degeneration of the seminiferous tubules. A decrease in the sperm counts of the epididymal spermatozoa was also observed in the animals of the acrylonitrile-exposed group. These observations suggest that acrylonitrile may affect the male reproductive function by causing testicular injury.

Acid Phosphatase↗
PubMed1988

CSF biochemical correlates of mixed affective states.

To evaluate the question of whether "mixed" bipolar disorder is a distinct entity, we compared selected cerebrospinal fluid (CSF) biochemical parameters from patients with bipolar disorder, mixed, to those with mania and major depression. Fourteen patients in each category (DSM-III) were studied with regard to CSF HVA, 5HIAA, sodium, potassium, calcium, and magnesium levels under carefully controlled conditions. CSF HVA, 5HIAA, and sodium were found to be significantly higher in manics than in major depressives. Discriminant analysis of the biochemical variables of the mixed affective group identified two biochemically distinct and clinically different subgroups of seven patients each, one resembling the manic group and the other the major depressive group. These findings suggest that mixed affective states do not exist as a separate entity, but are composed of two subgroups obtained from the manic and major depressive categories.

Adult↗