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Biomedical subjects

R Arora

Publications and source records attributed to R Arora.

At least 37 records · Page 2Linked to original sources
PubMed1996

Balloon dilatation of inferior vena cava stenosis in Budd-Chiari syndrome.

Percutaneous balloon angioplasty was used to dilate inferior vena cava (IVC) stenosis in 12 patients with Budd Chiari syndrome. There were seven men and five women, aged 32.8 +/- 8.5 years. Angioplasty was performed using balloon 18-20 mm in diameter. In eleven (91.6%) patients, IVC could be successfully dilated. In these eleven patients, the caval diameter at the site of stenosis increased from 2.3 +/- 1.5 to 13.1 +/- 2.8 mm (p < 0.001), the mean IVC pressure decreased from 28.2 +/- 4.1 to 10.5 +/- 3.4 mmHg (p < 0.001) and the gradient across the stenosis decreased from 23.1 +/- 2.2 to 4.2 +/- 1.9 mmHg (p < 0.001). There was appreciable clinical improvement after angioplasty. On a mean followup of 10.8 (3-18) months four (36.4%) patients had restenosis which could be successfully dilated again. These results suggest that balloon dilatation of inferior vena cava stenosis is safe and effective, however, recurrence is common and needs redilatation.

Adolescent↗
PubMed1995

A complete plasmid-based complementation system for RNA coliphage Q beta: three proteins of bacteriophages Q beta (group III) and SP (group IV) can be interchanged.

Our laboratory has established a bacteriophage Q beta cDNA-containing plasmid system in which virtually all coding defects present within the 4217 nucleotide Q beta genome can be complemented in trans. In this system, Q beta minus strand RNAs are constitutively transcribed from plasmid cDNA by Escherichia coli RNA polymerase. Replication of these minus strands results in the synthesis of Q beta plus RNA, thereby triggering an infectious cycle in which Q beta phase particles are generated. Genetically engineered Q beta genome mutations that result in defective viral proteins can be complemented in trans by the products of one or more Q beta helper plasmids that express either: (1) Q beta maturation protein, which can complement defects in the Q beta maturation cistron (nucleotides 61 to 1320); (2) Q beta readthrough protein, which can complement defects in the readthrough cistron (nucleotides 1344 to 2330); or (3) Q beta replicase, which can complement defects in the replicase cistron (nucleotides 2352 to 4118). Each plasmid component of this system contains a unique origin of replication and carries a different antibiotic gene, thereby enabling all combinations of these plasmids to coexist in the same host. We have further developed a second series of helper plasmids that generate the corresponding viral proteins of the related group IV RNA phage SP. Each of these SP helper proteins can complement respective defects within the Q beta genome with efficiencies similar to those observed for the Q beta helper proteins. It is now possible to supply functional Q beta or SP proteins in trans to examine Q beta genomes that contain protein coding defects for their ability to synthesize Q beta proteins, replicate Q beta RNA, assemble virions, and/or lyse the host cell.

Allolevivirus↗
PubMed1995

Effects of balloon mitral valvuloplasty on left ventricular muscle function.

Echocardiographically determined ventricular load and performance were compared in 40 consecutive patients with severe mitral stenosis before and 24 h after successful and uncomplicated balloon mitral valvuloplasty in order to clarify the role of loading conditions in causation of reduced left ventricular ejection fraction. After valvuloplasty, mitral valve area increased 2-fold. A modest increase in ejection fraction (53 +/- 11% to 57 +/- 8%, P = 0.021) occurred with an insignificant increase in end-diastolic volume (44 +/- 10 to 48 +/- 16 ml/m2, P = 0.063) and no change in wall stress (61 +/- 19 to 59 +/- 19 kdynes/cm3, P = 0.85) (10(5) dynes = 1 N). There was no correlation between changes in fractional shortening and wall stress (r = 0.07) and between changes in end-diastolic volume and fractional shortening (r = 0.12). Contractile performance estimated by a performance-afterload relation was unchanged after the valvuloplasty. Factors other than a change in loading conditions might be responsible for a modest improvement in ejection performance following mitral valvuloplasty.

Adolescent↗
PubMed1995

A study of infective aetiology of chronic diarrhoea in children in Amritsar.

Examination of 150 stool samples from children of less than 3 years of age of chronic diarrhoea showed the presence of various enteropathogens in 58.7% cases. Cryptosporidium in pure form, Entamoeba histolytica and Giardia lamblia were detected in 1.3%, 2% and in 4% cases respectively. In 1.3% children Candida albicans was isolated. The predominant bacterial isolate was enteropathogenic Escherichia coli (21.4%). Salmonella typhimurium, shigella and campylobacter were isolated in 8.6%, 4% and 0.7% children respectively.

Child, Preschool↗
PubMed1995

Enterotoxigenic enteric bacteria causing secretory diarrhoea.

Two hundred and fifty enteric bacteria isolated from cases of secretory diarrhoea of all age groups were studied for their enterotoxigenicity and prevalence of drug resistance. The principal pathogens were Escherichia coli 44.4%, Vibrio cholerae 28.8%, Salmonella typhimurium 19.2% and Campylobacter jejuni 2.4%. 104 (42.6%) strains were enterotoxigenic; V. cholerae (100%), Escherichia coli (25.2%) and Non-E. coli enterobacteria (6.5%). While 89.3% and 100% Enterotoxigenic Escherichia coli and Salmonella typhimurium strains were multi drug resistant, 40% and 100% respectively showed transfer of R-plasmids to standard receipt strains. In V. cholerae multi drug resistance was observed in only 5.5% strains.

Adolescent↗
PubMed1994

Improved Doppler assessment of the Bjork-Shiley mitral prosthesis using the continuity equation.

To assess whether derivation of an effective mitral prosthetic valve area using the continuity equation provides an improved functional assessment of the Bjork-Shiley mitral prosthesis over the pressure half-time method, Doppler echocardiographic studies were performed in 43 patients 12 +/- 7 months following the valve replacement. Effective valve orifice area used as the standard for comparison was determined by a hydraulic formula validated in vitro over a wide range of flow rates. All patients were clinically stable, without evidence of prosthetic dysfunction or aortic regurgitation. Prosthetic mitral valve orifice area determined by the hydraulic formula, by the continuity equation and by pressure half-time method for all prostheses sizes averaged 1.6 +/- 0.46 cm2, 1.83 +/- 0.56 cm2 and 2.34 +/- 0.48 cm2, respectively. Effective valve orifice area by the hydraulic formula had a strong correlation with that derived by the continuity equation (r = 0.86; P < 0.0001; standard error of estimate (S.E.E.), 0.12 cm2), but an insignificant correlation with the area calculated by the pressure half-time method (r = 0.24). Prosthetic mitral valve areas determined by the continuity equation and by pressure half-time method also correlated poorly (r = 0.24). Pressure half-time was affected by heart rate, diastolic filling period, left ventricular fractional shortening and presence of atrial fibrillation (P < 0.001). Thus, using the standard continuity equation to determine the orifice area of the Bjork-Shiley prosthesis in the mitral position provides improved assessment compared with the pressure half-time method.

Adolescent↗
PubMed1994

Percutaneous mitral commissurotomy for severe mitral stenosis during pregnancy.

Percutaneous mitral commissurotomy was performed in 27 pregnant females aged 24.9 +/- 3.14 years (range 20-30 years) with severe mitral stenosis at 22.2 +/- 4.3 weeks (range 18-32 weeks) of gestation. All patients were in New York Heart Association functional class IV at the time of procedure. The procedure was performed using the flow guided Inoue balloon in 25 patients and double balloon technique in 2 patients. Percutaneous mitral commissurotomy was successful in 26 patients. The mitral valve area assessed by Doppler echocardiography (pressure half time) increased from 0.78 +/- 0.19 cm2 (range 0.5-1.0 cm2) to 2.2 +/- 0.12 cm2 (range 1.9-2.6 cm2) (P < 0.001). The mean mitral gradient decreased from 30.5 +/- 7.6 mm Hg (range 22.5-41.4 mm Hg) to 6.1 +/- 2.6 mm Hg (range 4.2-12.3 mm Hg) (P < 0.001). The end diastolic gradient decreased from 28.3 +/- 4.2 mm Hg (range 23-37 mm Hg) to 2.8 +/- 1.5 mm Hg (range 0-5 mm Hg) (P < 0.001). The total fluoroscopy time was 5.6 +/- 2.2 min (range 2.7-8.9 min). Mitral regurgitation increased by one grade in 7 patients. One patient developed severe mitral regurgitation with anterior mitral leaflet tear needing immediate mitral valve replacement. Twenty-six patients improved to New York Heart Association class I after the procedure. Twenty-four patients had full-term, normal delivery and gave birth to healthy infants. The patients were followed up for 1-36 months (mean 16.6 +/- 7.8 months).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Transcatheter occlusion of patent ductus arteriosus by Rashkind umbrella device: follow-up results.

Seventy-six patients (36 boys and 40 girls) with patent ductus arteriosus who had successful ductal occlusion with a Rashkind umbrella device were monitored for a period of 6 to 60 months (mean 26.7 +/- 12.3 months). All patients were evaluated by pulsed and color Doppler echocardiography before and after the procedure. The prevalence of residual left-to-right shunt and main pulmonary artery flow pattern were assessed. Residual left-to-right shunt was seen in 12 (15.7%) patients 24 hours after the procedure, but the shunt was small with a pulmonary-to-systemic blood flow ratio of < 1.3:1. Repeat echo Doppler study at 14 days showed residual left-to-right shunt in 10 (13.1%) patients. None of these patients showed further decrease in prevalence of residual left-to-right shunt. The patients with residual left-to-right shunt had larger ductii (mean 5.17 +/- 0.88 mm, range 4.23 to 6.6 mm) as compared to patients with no residual left-to-right shunt (3.31 +/- 0.86 mm, range 1.8 to 4.69 mm; p < 0.001). Two patients with residual shunt had successful ductus reocclusion, with 12 and 17 mm devices, respectively, at 28 month of follow-up. The Rashkind umbrella device is effective in closing ducti with diameters of < 5 mm in majority of patients.

Adolescent↗
PubMed1994

Percutaneous transatrial mitral commissurotomy: immediate and intermediate results.

OBJECTIVES: The purpose of this study was to evaluate the immediate and follow-up results of percutaneous transatrial mitral commissurotomy in 600 patients with rheumatic mitral stenosis. BACKGROUND: Percutaneous transatrial mitral commissurotomy has emerged as an effective nonsurgical technique for patients with symptomatic mitral stenosis. Several studies have shown that the immediate results are comparable to closed and open mitral valvotomy. METHODS: Percutaneous transatrial mitral commissurotomy was performed in 600 patients with rheumatic mitral stenosis by the double-balloon (290 patients [48.3%]) and flow-guided Inoue balloon (310 patients [51.7%]) techniques. There were 154 male (25.6%) and 446 female (77.4%) patients with a mean [+/- SD] age of 27 +/- 8 years (range 8 to 60). Atrial fibrillation was present in 26 patients (4.3%), mitral regurgitation < or = grade 2 in 62 (10.3%) and densely calcific valve in 12 (2%). All patients had clinical and echocardiographic (two-dimensional, continuous wave Doppler, color flow imaging) follow-up at 3-month intervals. RESULTS: Percutaneous transatrial mitral commissurotomy was successful in 589 patients (98.1%), and optimal commissurotomy was achieved in 562 (93.6%), with an increase in mitral valve area from (mean +/- SD) 0.75 +/- 0.18 to 2.2 +/- 0.38 cm2 (p < 0.001) and a decrease in transmitral end-diastolic gradient from 27.3 +/- 6.1 to 3.8 +/- 4.2 mm Hg (p < 0.001). Mitral regurgitation developed or increased in 208 patients (34.6%). Six patients (1%) with mitral regurgitation required mitral valve replacement. Cardiac tamponade occurred in 8 patients (1.3%). Six patients (1%) died. Restenosis developed in 10 patients (1.7%) during a mean follow-up period of 37 +/- 8 months (range 6 to 66). CONCLUSIONS: Percutaneous transatrial mitral commissurotomy is an effective, safe procedure with gratifying intermediate results. It should be considered the treatment of choice for rheumatic mitral stenosis.

Adolescent↗
PubMed1994

Cold acclimation in genetically related (sibling) deciduous and evergreen peach (Prunus persica [L.] Batsch). II. A 60-kilodalton bark protein in cold-acclimated tissues of peach is heat stable and related to the dehydrin family of proteins.

In several plant species, certain cold-regulated proteins share unique properties. These proteins are (a) heat stable and (b) hydrophilic and are related to the Group 2 late embryogenesis abundant or dehydrin family of proteins. Our previous work with sibling deciduous and evergreen peach genotypes demonstrated a correlation between the level of accumulation of certain bark proteins and cold-acclimation potential of these tissues. Here we identify a 60-kD bark protein in peach (Prunus persica [L.] Batsch), PCA60 ("peach cold acclimation"), that is accumulated during cold acclimation and is heat stable. Immunological studies indicated that this protein is related to the dehydrin family of proteins and accumulates at much higher levels in the bark tissues of the deciduous genotype than in the evergreen. Amino acid composition indicated that the 60-kD protein has a compositional bias for glycine (24%), glutamic acid/glutamine (11.4%), aspartic acid/asparagine (10%), and threonine (9.6%), contains relatively low levels of aromatic amino acids (phenylalanine and tyrosine), and is rich in hydrophilic amino acids. A novel characteristic of the 60-kD cold-acclimation protein is the presence of a repeating nine-amino acid sequence. A five-amino acid stretch, which is included within this repeating motif, shares striking homology with other cold-regulated proteins and dehydrins.

Acclimatization↗
PubMed1994

Acute dexfenfluramine administration normalizes glucose tolerance in rats with insulin-deficient diabetes.

Dexfenfluramine has been shown to lower blood glucose concentrations independently of its effects in reducing food intake and body weight, in human and animal syndromes of non-insulin dependent diabetes. This study aimed to determine whether dexfenfluramine could also reduce glycaemia in rats with severe insulin-deficient diabetes induced by the beta-cell toxin, streptozotocin (55 mg kg-1). Three weeks after diabetes induction, nine groups (each n = 10) of diabetic and non-diabetic rats underwent oral glucose tolerance tests (1 g kg-1, by gavage). These tests were preceded by 12-18 h of fasting to remove the confounding effects of hyperphagia in diabetic rats, and to stabilize glycaemia. Dexfenfluramine (1.0 mg kg-1), given 2 h before the glucose challenge, significantly reduced basal glycaemia and decreased the post-challenge glycaemic rise (P < 0.01 vs. untreated diabetics). Dexfenfluramine dosages of 2.5 and 5.0 mg kg-1 both further flattened the post-challenge glycaemic profiles (both P < 0.01 vs. untreated diabetics) and achieved levels that did not differ significantly from those in non-diabetics (both P > 0.05). Subsequently, the studies using dexfenfluramine dosages of 2.5 and 5.0 mg kg-1 were repeated to determine whether the drug affected plasma insulin levels 2 h after dosing. In diabetic rats, plasma insulin concentrations were reduced to 10-20% of non-diabetic values, and were not significantly altered by dexfenfluramine. Acute dexfenfluramine administration therefore improves and (at dosages of 2.5 and 5.0 mg kg-1) essentially normalizes glucose tolerance in rats with severe insulin-deficient diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Clinical recognition of granulomatous angiitis of the brain. Novel magnetic resonance image.

Granulomatous angiitis of the brain is a rare form of vasculitis affecting small and medium-size blood vessels. The most common initial symptoms include headache and confusion after age 45. The cerebrospinal fluid is almost always abnormal with lymphocytic pleocytosis and protein content over 100 micrograms/dl. Diagnosis may be supported by contrast-enhanced magnetic resonance imaging findings of a hypointense granuloma surrounding a hyperintense blood vessel. Described herein is a previously unrecorded magnetic resonance image in an autopsied case of granulomatous angiitis of the brain.

Adult↗
PubMed1994

Incidence of congenital heart disease among hospital live births in India.

Ten thousand nine hundred and sixty four consecutive live births weighing more than 500 g and more than 28 weeks of gestation were subjected to a thorough clinical examination within 24 h of birth. Those suspected of having congenital heart disease (CHD) were followed up every 4-6 weeks for a period of 6 to 18 months (mean 9.75 months). Forty three of 10,964 infants had CHD, i.e., 3.9/1000 live births. Incidence of CHD was higher in pre-terms as compared to full term live births (22.69 vs 2.36/1000 live births). Diagnosis was confirmed by echocardiography including 2D, Doppler and color flow imaging. Twenty eight per cent of the infants with CHD had other associated somatic anomalies, Down's syndrome being the commonest (9.3%). Patent ductus arteriosus (41.9%) and ventricular septal defects (VSD) (34.9%), were the commonest lesions with an incidence of 1.6 and 1.4/1000 live births, respectively. Incidence of PDA was higher probably because of larger number of pre-term deliveries. During follow up of 6-18 months, 34.9% of the infants with CHD died. The diagnosis of CHD was confirmed at autopsy in 20% of the deaths.

Abnormalities, Multiple↗