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Biomedical subjects

R Tandon

Publications and source records attributed to R Tandon.

At least 235 records · Page 13Linked to original sources
PubMed1986

Left ventricular function in isolated rheumatic mitral stenosis in children.

A total of 18 patients with pure rheumatic mitral stenosis between the ages of eight and 14 years (average 11.8 years) were studied. Left ventricular angiograms in the right anterior oblique view were obtained in each. Moderate to severe pulmonary arterial hypertension was present in all but one. The mean left ventricular end-systolic volume index was 25.4 +/- 8.5 ml/m2; it was increased in five patients. The mean left ventricular end-diastolic volume index was 64 +/- 13.5 ml/m2. It was normal in all except one patient, in whom it was increased to 91 ml/m2. The left ventricular stroke volume index, 39.6 +/- 8.8 ml/m2, was within the normal range. The left ventricular stroke volume index, 39.6 +/- 8.8 ml/m2, was within the normal range. The mean left ventricular ejection fraction was 0.61 +/- 0.09 ml, with a range of 0.44-0.72. The mean left ventricular ejection fraction was lower than normal (P less than 0.05). The ejection fraction was low in five of the 18 patients. Four of the five patients with an ejection fraction below 0.60 had severe pulmonary arterial hypertension. There was no correlation between the ejection fraction and left atrial pressure or the mitral valve area. Segmental contraction analysis in the five patients with a low ejection fraction showed global hypokinesia in four and segmental hypokinesia, involving predominantly the posterobasal segment, in one patient. Our study suggests that even children with pure mitral stenosis may have left ventricular dysfunction in the absence of active carditis.

Adolescent↗
PubMed1984

Selective liquid chromatographic isolation and gas chromatographic-mass spectrometric analysis of ketonic bile acids in faeces.

A method is described for the separation of ketonic from non-ketonic bile acids. Oximes are prepared from the methyl esters and are subjected to chromatography on the lipophilic strong cation exchanger sulphohydroxypropyl Sephadex LH-20 (SP-LH-20) in the H+ form. Three fractions are obtained which contain non-ketonic compounds, compounds having a 7- or 12-oxime but no 3-oxime group, and compounds having a 3-oxime group. These groups can be analysed as trimethylsilyl ethers by gas chromatography and gas chromatography-mass spectrometry by using fused-silica capillary columns with SE-30 as the stationary phase. The method was applied to the analysis of bile acids in faeces. The major 3-oxo acids found were 3-oxo-5 beta- and 12 alpha-hydroxy-3-oxo-5 beta-cholanoic acids. Smaller amounts of 3,12-dioxo-5 beta-cholanoic acid were present and 3-oxo-5 alpha-cholanoic and 3-oxo-4-cholenoic acids were also identified, but could not be quantified. Semiquantitative analyses indicated that bile acids with a 3-oxo group may constitute 1-20% of the corresponding 3 alpha-hydroxy bile acids.

Bile Acids and Salts↗
PubMed1984

[Isolation and quantification of nonsulfated and sulfated bile acids in the feces].

A method is described for the qualitative and quantitative analysis of non-sulphated and sulphated bile acids in faeces. After extraction and preliminary purification, the faecal bile acids are separated by liquid-gel-chromatography (DEAP-Sephadex LH20) into free, conjugated and sulphated bile acids; these are quantitated separately (after solvolysis and hydrolysis), and the individual bile acids are analysed by gas-liquid-chromatography. The validation both of the individual analysis steps and the overall procedure by adding bile acid standards to the faecal homogenates showed a good reproducibility and a reliable separation of non-sulphated and sulphated bile acids. Using the described method, the excretion of total faecal bile acids in 15 control subjects was 3.85 mg/g dry stool, consisting of 10.4% primary bile acids and 89.6% secondary bile acids. 92.9% of faecal bile acids were in the free form, only 2.7% in the conjugated form, and 4.4% as sulphated bile acids.

Bile Acids and Salts↗
PubMed1982

Hemodynamic effects of sodium nitroprusside in patients with ventricular septal defect.

During routine cardiac catheterization of ten patients with ventricular septal defect, the hemodynamic parameters were measured in the resting state and during sodium nitroprusside infusion at an average rate of 8 micrograms/kg/min. Two distinct hemodynamic groups could be identified. Group I characterised by elevated left ventricular filling pressure showed a consistently favourable response to sodium nitroprusside infusion with a decrease in the left ventricular filling pressure, the pulmonary arterial pressures and the left to right shunt. The favourable effect was most pronounced in patients who had pulmonary arterial hypertension in addition to elevated left ventricular filling pressures. Group II patients characterised by normal left ventricular filling pressures showed a variable response to sodium nitroprusside administration. The left ventricular end-diastolic pressure fell or was unaltered. The pulmonary arterial pressures and pulmonary vascular resistance fell in those with pulmonary arterial hypertension. Patients without pulmonary arterial hypertension showed an increase in the magnitude of left to right shunt. On the basis of our data, we feel that vasodilator drugs have a specific role in the management of congestive heart failure secondary to large left to right shunts. The present study strongly indicates the need for further investigations utilizing orally effective vasodilators in patients with congestive heart failure due to left to right shunts.

Adolescent↗