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Biomedical subjects

R Arora

Publications and source records attributed to R Arora.

At least 55 records · Page 3Linked to original sources
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↗
PubMed1994

Age related changes in gastrocnemius, diaphragm and heart muscles with special reference to SDH and m-ATPase.

Age related histochemical and biochemical decrease in succinic dehydrogenase (SDH) and myofibrillar ATPase (m-ATPase) activity was observed in diaphragm, leg and heart muscles of rat. The effects of ageing varied in intensity in different muscle types and were more pronounced in fast muscles. Decrease in m-ATPase may be the result of age related decrease in number of contractile elements revealed by low content of electrophoretically analysed myofibrillar proteins. Restructuring in nerve muscle junction reported, was in relation to normal variation in functional demands of rat from different age groups because of transient changes in work load.

Adenosine Triphosphatases↗
PubMed1994

Immunological profile in congenital heart disease.

Fifty children with established congenital heart disease (CHD) were surveyed for the immune profile. Ventricular septal defect (VSD) was the commonest lesion (56%) followed by Tetralogy of Fallot (ToF; 16%), atrial septal defect (ASD; 8%), patent ductus arteriosus (PDA; 4%), transposition of great arteries (TGA; 4%), aortic stenosis (AS; 4%), and pulmonic stenosis (PS), tricuspid atresia (TA), single ventricle with pulmonic stenosis (SV with PS) and dextrocardia with ToF (2% each). Immunoglobulins (IgG, IgA and IgM) were estimated. IgG and IgA levels were significantly reduced in all children with congenital heart disease, whereas IgM levels were increased in cyanotic but unaffected in the acyanotic group. Complement C3 and C4 levels were reduced in all, more so in cyanotics. T-helper cells were decreased and T-suppressor cells were increased in all groups with congenital heart disease as compared to controls. B-cell percentage was increased in cyanotics but not affected in the acyanotics.

Antibody Formation↗
PubMed1994

Role of adrenal in establishment and development of conceptus in unilaterally ovariectomized mated rats.

The model of unilateral ovariectomy induced ovarian compensatory hypertrophy in mated bilaterally adrenalectomized rats was used to assess the role of adrenal in conceptus development. Replacement dose of dehydroepiandrosterone (DHA) or corticosterone (Comp. B) from day 2-14 post coitum was given with or without ip injections of estrogen (E, on day 2) and progesterone (P, on day 3 or 3-9). Replacement of adrenal hormones failed to support ipsilateral uterine horn (IP) pregnancy. But injections of E2 and P support IH pregnancy in variable percentages (about 38-75%) of rats depending on the type of adrenal steroids and single or multiple doses of P. Contralateral horn (CH) pregnancy developed under any of these conditions. Adrenalectomy induced reduction of fetal weight and pregnancy index (No. of fetus divided by No. of implantation sites), were not significantly improved by adrenal hormone replacement, except pregnancy index of those animals which received Comp. B and P. Adrenalectomy inhibited compensatory increase of contralateral corpus luteum (CL) volume and ovarian delta 5(3)beta-hydroxy steroid dehydrogenase (delta 5(3)beta-HSD) activity. Replacement of DHA or Comp. B induced these compensatory changes. Comp. B and P appears to be a better combination in establishment of IH pregnancy, pregnancy index maintenance and stimulation of ovarian compensatory changes. Results suggest that adrenocorticoids were not obligatory for conceptus development but were important for efficient action of ovarian steroids in establishment and maintenance of pregnancy. Relationship between nutrition or pituitary gonadotropins and adrenal steroids, having relevance to conceptus development has been discussed.

Adrenal Glands↗
PubMed1994

Eye casualty department.

A retrospective analysis of all new patients attending our eye casualty department was carried out during the 1 year period, from January to December 1987. During this time the casualty unit saw and treated 4905 new patients. Of these 40.61% were traumatic in origin, 30.52% comprised various ocular infections and the remaining 28.87% had miscellaneous ocular problems. On average, 13 new patients and seven consultations from other departments were seen and treated daily. Apart from the management of ocular emergencies, other functions provided by our department included glaucoma screening, donor eye collection, attending to referrals from other departments and eye health education.

Emergency Service, Hospital↗
PubMed1993

Immediate and long-term results of balloon and surgical closed mitral valvotomy: a randomized comparative study.

Balloon mitral valvotomy (BMV) constitutes an important alternative to surgical closed mitral valvotomy (CMV) for the treatment of rheumatic mitral stenosis. To compare the immediate and long-term results of these procedures, 200 patients with rheumatic mitral stenosis were randomly assigned to undergo either BMV (n = 100) or CMV (n = 100). The age range was 10 to 30 (mean 19.4 +/- 6.5) years. Both procedures resulted in significant and similar increases in mitral valve area (BMV: 0.85 +/- 0.26 to 2.39 +/- 0.94 cm2; CMV: 0.79 +/- 0.21 to 2.2 +/- 0.85 cm2; p = NS). Mitral regurgitation developed in 14 patients after BMV and in 12 patients after CMV. Eighty patients in each group have now been followed for a mean period of 22 +/- 6.3 (range 6 to 38) months by repeat echocardiographic study. Restenosis (defined as a loss of more than 50% of the achieved increase in mitral valve area) was seen in four (5%) patients after BMV and in three (4%) after CMV. Symptomatic restenosis was seen in only one patient who at follow-up examination 20 months after CMV had a mitral valve area of 0.8 cm2 and underwent successful balloon valvotomy. We conclude that the immediate and long-term results obtained with percutaneous BMV and surgical closed mitral commissurotomy are comparable.

Adolescent↗
PubMed1993

Long-term results after balloon pulmonary valvuloplasty in adults.

Percutaneous balloon pulmonary valvuloplasty for congenital pulmonary valve stenosis was performed in 40 adult patients (aged 18 to 56 years). The duration of follow-up was 24.5 +/- 11.5 months. The peak systolic pressure gradient from the right ventricle to the pulmonary artery decreased from 107 +/- 29 mm Hg to 37 +/- 25 mm Hg immediately after the procedure. On follow-up, gradient obtained either by cardiac catheterization or Doppler echocardiography was 31 +/- 13 mm Hg. In eight patients with residual gradient after valvuloplasty of > 50 mm, the mean peak systolic gradient decreased from 74.5 +/- 18.3 to 33.5 +/- 13.9 mm Hg on follow-up. Thus balloon pulmonary valvuloplasty is a safe and effective procedure for the treatment of adult patients with pulmonic stenosis; there is a tendency for high residual gradients to regress on follow-up.

Adolescent↗
PubMed1993

Balloon angioplasty for renovascular hypertension in Takayasu's arteritis.

Percutaneous transluminal renal angioplasty was performed in 54 consecutive patients with hypertension and renal artery stenosis caused by Takayasu's arteritis. Angioplasty was technically successful in 67 (89.3%) of 75 lesions attempted. In these 67 lesions, the degree of stenosis decreased from 88.3 +/- 4.8% to 23.5% +/- 13.6% (p < 0.001) after angioplasty. Following successful angioplasty there was significant improvement in hypertension (p < 0.001) within 48 hours. Patients with bilateral renal artery stenosis had higher systolic blood pressure both before balloon dilatation (p < 0.05) and after balloon dilatation before discharge (p < 0.001), compared with patients with unilateral renal artery stenosis. Three to 70 months (mean 26.4 +/- 10.3 months) after successful angioplasty, blood pressure was reduced to normal or was improved in 93% of patients. Angiographic restudy an average of 14.2 +/- 7.8 months after angioplasty showed restenosis at the same site in 7 of 52 (13.5%) lesions and fresh stenosis in one artery. All these eight lesions were successfully dilated. Further improvement in the luminal diameter was observed in 11 (21.2%) lesions. Late angiographic restudy in seven patients an average of 56.1 +/- 6.3 months after angioplasty showed no restenosis. Our results suggest that balloon angioplasty is safe and highly effective in relieving renal artery stenosis caused by Takayasu's arteritis and should be the treatment of choice for renovascular hypertension in this disease.

Adolescent↗
PubMed1993

Cross-sectional echocardiographic left ventricular geometry in rheumatic mitral stenosis.

The ultrastructural myopathic changes and deranged left ventricular contractile function have been reported in patients with rheumatic mitral stenosis. It is not clear if as a result of these myopathic changes, global left ventricular myocardial remodelling occurs to alter its normal elliptical shape in the absence of qualitative segmental asynchrony. To study the left ventricular cavity shape independent of chamber size, cross-sectional echocardiographically measured longest long axis (L) of the left ventricular cavity in the apical four-chamber view and short axis diameters at the level of tips of the mitral leaflets in the parasternal long axis view (D-1), of the basal cavity (D-2) and the apical segment (D-3) in the apical four-chamber view at end-diastole and their ratio, were studied in 20 patients with isolated rheumatic mitral stenosis. Twenty healthy volunteers matched for age, sex, heart rate, height and body surface area provided the normal control data. The patients with mitral stenosis had shorter long axis diameter (7.2 +/- 0.7 vs 7.9 +/- 0.5 cm, p < 0.001) and greater short axis/long axis diameter ratios at every level with the most pronounced change in the apical segment of the cavity (D-3/L 0.49 +/- 0.09 vs 0.40 +/- 0.05, p < 0.001). Left ventricular end-diastolic sphericity index was also markedly increased in the patients with mitral stenosis (0.57 +/- 0.09 vs 0.40 +/- 0.05, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Atrial septal defect after balloon mitral valvuloplasty: a transesophageal echocardiographic study.

Fifty patients with rheumatic mitral stenosis aged twelve to thirty-six (twenty +/- six) years were studied by two-dimensional, pulsed and color Doppler echocardiography during, seventy-two hours after, and biweekly for three months after balloon mitral valvuloplasty (BMV). Transesophageal echocardiography (TEE) done immediately after BMV (in the catheterization laboratory) detected a new atrial septal defect (ASD) in 46 (92%) patients. These measured 1 to 2 (mean 1.2 +/- 0.3) mm in diameter. Doppler color flow mapping guided the location of the ASD in most of the cases. A narrow jet of left-to-right shunt could be evaluated by pulsed Doppler studies. Velocity time integral (VTI) of the jet across one cardiac cycle and the diameter of the ASD were used to calculate the left-to-right shunt (shunt = VTI x pi (D/2)2 x heart rate). The estimated shunt was 0.04-0.39 (mean 0.20 +/- 0.10) L/minute. A repeat study at seventy-two hours revealed the defect in 40 (80%) patients. At three months, the defect persisted in only 5 (10%) cases. The mean interval of closure of ASD was 4.6 +/- 2.2 weeks. The authors conclude: (1) ASD occurs commonly after BMV, (2) the septal defect and the resultant left-to-right shunt are insignificant, and (3) ASD disappears in the majority of cases by three months after BMV.

Adolescent↗