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Biomedical subjects

S Radhakrishnan

Publications and source records attributed to S Radhakrishnan.

At least 55 records · Page 3Linked to original sources
PubMed1996

Use of dopamine in prevention of contrast induced acute renal failure--a randomised study.

We report the use of dopamine in renal doses (5 micrograms/kg/min) to prevent contrast induced nephropathy (CIN). Forty patients with diabetes mellitus who were undergoing coronary angiography were randomly divided into two groups. Gr I (20 patients) was infused with dopamine starting 30 min before cardiac catheterization and continued for 6 h thereafter. Gr II (20 patients) did not receive dopamine. Baseline blood chemistry was performed before catheterization and then repeated 24 h after the procedure. The mean age and sex distribution were similar in both the groups. Urograffin (76%; 120-150 ml) was used in all the cases. The mean serum creatinine and blood urea nitrogen (BUN) levels in Gr I patients before catheterization were 1.5 +/- 0.32 mg % and 16.3 +/- 8.05 mg %, respectively. The corresponding values for Gr II were 1.52 +/- 0.68 mg % and 19.6 +/- 13.4 mg %, respectively. After angiography, Gr I patients did not show significant changes in renal parameters (serum creatinine, 1.37 +/- 0.25 mg % and BUN, 14.7 +/- 5.5 mg %) while Gr II patients showed a significant rise (serum creatinine, 1.96 +/- 1.2 mg % and BUN, 23.25 +/- 12.7 mg %; P = 0.01 and P = 0.05, respectively). Ten patients in Gr II (50%) developed a 25% rise in serum creatinine levels within 24 h of injection of the contrast. None of the patients developed renal failure severe enough to warrant dialysis. Hence alterations of renal function are common after cardiac catheterization. Dopamine in renal doses appears to be an effective means to prevent deterioration in renal function induced by contrast.

Acute Kidney Injury↗
PubMed1996

Three-dimensional time-of-flight MR angiography of the arch of aorta and its major branches: a comparative study with contrast angiography.

The region of the arch of aorta and the intrathoracic course of its major branches was evaluated in 11 patients using three-dimensional time-of-flight magnetic resonance (MR) angiography. Abnormalities such as stenosis, occlusion, dilatation and aneurysm formation were documented in the innominate, both common carotid and both subclavian arteries. The results were compared with those of contrast angiography. There was a good correlation in 47 of the 55 arteries compared. There were five false positive results including overestimation of a stenosis, and three false negative results including underestimation of a stenosis. MR angiography had a sensitivity of 93% and a specificity of 89% for correctly detecting or excluding an abnormality. These results suggest that three-dimensional time-of-flight MR angiography demonstrates lesions in the major branches of the arch of aorta fairly accurately and will prove useful in the initial evaluation and in follow up studies.

Adolescent↗
PubMed1996

Effect of vitamin A supplementation to mother and infant on morbidity in infancy.

OBJECTIVES: To assess the impact of Vitamin A supplementation to the mother soon after delivery and to the infant at six months on morbidity in infancy. DESIGN: Randomized double blind placebo controlled field trial. SETTING: 51 villages in two contiguous Primary Health Centers in Villupuram Health Unit District of Tamil Nadu, South India. SUBJECTS: 909 newly delivered mother-and-infant pairs. INTERVENTIONS: Both mother and infant received Vitamin A (300,000 IU for mothers and 200,000 IU for children) in 311 instances (AA); mother received Vitamin A but infant received Placebo in 301 instances (AP); and both mother and infant received Placebo in the remaining 297 instances (PP). MAIN OUTCOME MEASURES: Incidence of diarrhea and Acute Respiratory Infection (ARI); distributions of infants by frequency of episodes and number of infected days. RESULTS: 233 in the AA Group and 228 each in the AP and PP Groups were followed up regularly. The incidence of diarrhea in these infants was 97.4%, 96.9% and 94.7% in the three groups, mean number of diarrheal episodes was 4.4, 4.6 and 4.2 and median number of days in infancy with diarrhea was 26, 26 and 22 days, respectively. For ARI, the incidences were 96.6%, 95.6% and 96.1%, means were 4.8, 5.1 and 4.8 episodes, and the medians were 32, 34 and 34 days, respectively. CONCLUSIONS: Prophylactic administration of mega doses of Vitamin A to the mother soon after delivery and to the infant at six months do not have any beneficial impact on the incidence of diarrhea and ARI in infancy.

Adult↗
PubMed1995

Changing patterns of group B streptococcal serotypes associated with human infections.

One hundred strains of group B streptococci (GBS) isolated from diverse clinical specimens of patients seen in our hospital were subjected to serotyping by an indigenously prepared coagglutination system. Serotype NT/c was the most predominant (24%), followed by Ia (23%), II/c (12%) and Ib (11%). Type Ia was the most predominant in all specimens except genital samples where NT/c was the most predominant. Comparison of the distribution of serotypes identified during 1975-78 with that of the present study showed a great increase in the prevalence of types NT/c, II/c and Ia and a dramatic decline of types III, Ia/c and Ib. Despite the inclusion of reagents for newer serotypes, IV and V two strains were nontypable indicating the prevalence of hitherto unidentified GBS serotypes in our community.

Humans↗
PubMed1994

Left atrial dilatation in constrictive pericarditis: a pre and post-operative echocardiographic study.

Thirty-three surgically proven cases of constrictive pericarditis were studied pre-operatively by echocardiography for left atrial dilatation and 18 of them underwent post-operative study at a mean follow-up period of 229 +/- 105 days. The degree of left atrial dilatation in these patients was compared with patients of restrictive cardiomyopathy (n = 8) and sex matched controls of similar age (n = 33). Significant left atrial dilatation was present in patients of constrictive pericarditis compared to controls and it was of a similar or greater degree compared to patients of restrictive cardiomyopathy (the left atrium to aorta ratio was 1.7 +/- 0.31, 1.53 +/- 0.18 and 1.07 +/- 0.1, in constrictive pericarditis, restrictive cardiomyopathy and controls, respectively, P = NS for constrictive pericarditis vs. restrictive cardiomyopathy and P < 0.001 for constrictive pericarditis vs. controls). There was no correlation of degree of left atrial dilatation with clinical and hemodynamic variables. Postoperatively, there was regression of left atrial size in patients with normal hemodynamics (n = 12, pre- vs. post-operative left atrium to aorta ratio 1.65 +/- 0.23 vs. 1.32 +/- 0.14, P < or = 0.001) and persisting or increasing left atrial dilatation in patients with persisting hemodynamic abnormality (n = 6, left atrium to aorta ratio 1.66 +/- 0.23 vs. 1.82 +/- 0.15, P = NS). We conclude that significant left atrial dilatation is a consistent echocardiographic feature of constrictive pericarditis. Hemodynamic normalization following successful pericardiectomy is associated with regression of atrial size.

Adolescent↗
PubMed1993

Analysis of hand forces in health and disease during maximum isometric grasping of cylinders.

An analysis of force distribution in the hand during maximum isometric grasping actions is reported in a detailed and accurate manner. A microcomputer-controlled instrument which measures all 12 phalangeal forces of fingers simultaneously, in a single attempt at squeezing a cylindrical object, is described. The study involved 20 normal subjects of different weights and age groups grasping tubes of 50 mm, 75 mm, 90 mm and 110 mm diameters. Normal grasp forces decreased significantly with the increase in tube diameter, with the force being concentrated more on the distal segments of the fingers on the proximal and middle segments. The mean percentage contributions of finger forces to total grip strength, from index to little fingers, were 31, 33, 22 and 14 per cent, respectively. The study was extended to cover leprotic and paralytic hands to assess their functional capabilities. In the case of leprosy subjects, the grip strength decreased with the severity of the disease and was only about 50 per cent of that of normal subjects. In hemiplegics, the grip strength was only about one-eighth of the normal values. The above assessment procedure provides baseline data which could serve as guidelines to a clinician in assessing the severity of the disease and observing the patient's recovery following the treatment. It would also be useful in the design of hand-operated controls and prosthetic arms.

Fingers↗
PubMed1993

Atrio-ventricular regurgitations in constrictive pericarditis: incidence and post-operative outcome.

We studied 33 surgically proven cases of constrictive pericarditis during the period 1989-1991 by color Doppler echocardiography and angiography to look for incidence and postoperative outcome of atrioventricular regurgitation. The mean age was 27.2 + 16.5 years (21 males, 12 females). There was a very high incidence of mitral (79%, trivial in 13, mild in 11 and moderate in 2) and tricuspid (73%, trivial in 7, mild and moderate in 6 each and severe in 5) regurgitation. There was good correlation between 'color Doppler' and angiography for detection and quantification of these regurgitations (r = 0.89 for mitral and 0.76 for tricuspid regurgitation, respectively). There were no preoperative clinical or hemodynamic predictors for the incidence or severity of these regurgitations. Immediate postoperative (7-10 days) evaluation by color Doppler did not show any change in these regurgitations. A follow-up study (by color Doppler and angiography) in 18 patients at a mean period of 229 + 105 days revealed regression of these regurgitations by at least 1 grade in 50% of patients. Patients with persisting regurgitations had persisting hemodynamic abnormality and relatively longer duration of symptoms. The presence of atrio-ventricular regurgitations should not be taken as evidence favoring diagnosis of restrictive cardiomyopathy and against that of constrictive pericarditis. The mechanism of these regurgitations is not clear to us.

Adult↗
PubMed1993

Helicobacter pylori-associated gastritis in Kuwait: endoscopy-based study in symptomatic and asymptomatic children.

Information is limited concerning the prevalence of Helicobacter pylori infection in asymptomatic children. Since January 1989, we have endoscoped 60 children for recurrent abdominal pain or for obtaining small-intestinal biopsy (their ages were a mean of 6.6 (range 9 months-13 years); there were 37 boys and 23 girls. Antral biopsies were obtained from all subjects and these were studied for the presence of gastritis and stained for H. pylori using modified Gram's stain. All biopsies were cultured for H. pylori. Children endoscoped for small-intestinal biopsy (n = 18) were used for comparison. Of the 42 children who had abdominal pain, 24 showed histological gastritis and 13 had H. pylori on microscopy (31% H. pylori-associated gastritis). In the compared group, five showed histological gastritis, and all had H. pylori on microscopy (27.7%). Culture was positive in 15; sensitivity was 85.7%. Six children, three pairs of siblings, had H. pylori gastritis supporting environmental etiology. Two had coinfection with intestinal giardiasis. Seven children were treated with daily oral amoxycillin (50 mg/kg) and tinidazole (20 mg/kg) for 6 weeks. In 3 (42.3%) H. pylori colonization cleared with healing of gastritis and resolution of symptoms. These results indicate that H. pylori gastritis is equally prevalent in symptomatic and asymptomatic children (31 and 27.7%, respectively; p > 0.05) in our population. It seems that the combination of oral amoxycillin and tinidazole is a poor choice in the treatment of H. pylori-associated gastritis in Kuwaiti children.

Abdominal Pain↗
PubMed1992

Echocardiographic variables affecting surgical outcome in patients undergoing closed mitral commissurotomy.

We studied, by transthoracic cross-sectional echocardiography, the influence of subvalvar pathology on the early hemodynamic result of closed mitral commissurotomy in 132 patients with severe rheumatic mitral stenosis (56 males, 76 females, mean age 25.2 yr, range 10-55) in our tertiary care hospital in North India from July 89 to December 91. The mitral subdistance ratio was calculated by dividing the distance between the papillary muscle tip and mitral valve in systole (apical 4-chamber view) by left ventricular diastolic length (apical long axis view). Nineteen patients with mild subvalvar pathology (mitral subdistance ratio > 0.18) and 71 patients with moderate, achieved a larger valve area (2.26 cm2 SD 0.54) than 42 patients with severe subvalvar pathology (mitral subdistance ratio < 0.12, postoperative valve area 2.09 cm2 SD 0.6, p < 0.05). In addition, 9 of these 42 patients (21%) developed significant mitral regurgitation (4 deaths), in contrast to 1/19 with mild and 6/71 with moderate subvalvar pathology. We conclude that echocardiography identifies patients with severe subvalvar pathology who fare poorly after closed mitral commissurotomy. However, this procedure would still be practised in developing countries like ours due to financial constraints.

Adolescent↗
PubMed1992

Hypoplastic right ventricle with mild pulmonary stenosis in an adult.

A rare cyanotic heart disease surviving to adulthood with minimal symptoms is presented. The final diagnosis was hypoplastic right ventricle with mild pulmonary stenosis, where the latter was not responsible for the right-to-left shunting across a large atrial septal defect. The differences from cases reported in the literature are highlighted.

Adult↗
PubMed1992

Discordance between abdominal and atrial arrangement in a case of complex congenital heart disease.

The report describes a rare case of a complex congenital heart disease wherein the splenic status and the relationship of the suprarenal abdominal great vessels strongly suggested right isomerism, but atrial morphology demonstrated usual atrial arrangement. It emphasises the increasing recognition that the arrangement of the abdominal organs need not accurately reflect atrial arrangement.

Abnormalities, Multiple↗