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Biomedical subjects

R Arora

Publications and source records attributed to R Arora.

At least 73 records · Page 4Linked to original sources
PubMed1997

Evaluation of neuropathy in patients on suramin treatment.

Suramin, a promising chemotherapeutic agent, causes a dose-limiting sensorimotor polyneuropathy. We undertook a phase 1 study of suramin that included serial neurologic and electrophysiologic examinations as part of the safety evaluation. We found that 6 of 41 (15%) patients developed suramin-induced demyelinating neuropathy which resembled Guillain-Barre syndrome clinically. There was 1 asymptomatic patient with electrophysiologic abnormalities suggestive of a demyelinating neuropathy. In addition, 1 patient with mild axonal neuropathy at baseline had deterioration of his symptoms during suramin treatment. Four asymptomatic patients developed electrophysiologic findings suggestive of a mild axonal neuropathy. We conclude that: (1) serial electrophysiologic monitoring is helpful for early detection of suramin-induced neuropathy; and (2) fixed dosing schedule of suramin without adaptive control does not lead to an increased incidence of demyelinating neuropathy when compared to adaptively controlled dosing schedules.

Adult↗
PubMed1997

Percutaneous transluminal angioplasty for renovascular hypertension in children: initial and long-term results.

OBJECTIVE: To evaluate the efficacy and safety of percutaneous transluminal renal angioplasty (PTRA) in children. METHODS: We performed aortography and attempted PTRA in 35 consecutive children (age 5 to 14 years, mean 10.8 +/- 2.5 years) with severe hypertension having > or = 75% renal artery stenosis (RAS). RESULTS: The stenosis was caused by aortoarteritis in 31 (88.6%) cases and by juvenile idiopathic fibromuscular disease (FMD) in four (11.4%) cases. Twenty-seven (77.1%) patients, including three having RAS of solitary functioning kidney with total occlusion of contralateral renal artery, had bilateral RAS and eight (22.9%) had unilateral RAS. PTRA was technically successful in 54 (91.5%) of 59 stenotic lesions in 31 (88.6%) of 35 patients. Both aortoarteritis and FMD patients had significant decrease in RAS after PTRA. One patient had acute reocclusion of one renal artery after bilateral PTRA, which could be successfully opened by reangioplasty. Postangioplasty angiographic restudy performed in 18 patients at 4 to 72 months (mean 23.1 +/- 27.9 months) after successful angioplasty showed restenosis in 8 (25.8%) of 31 lesions initially dilated and de novo lesions of aorta in two patients. All seven restenotic renal artery lesions attempted and both stenosis of aorta were successfully dilated. Twenty-nine of 31 patients with successful PTRA have been followed up from 4 to 108 months (mean 41.0 +/- 29.3 months). Mean systolic blood pressure decreased from 185.1 +/- 27.4 to 120.6 +/- 19.2 mm Hg and mean diastolic blood pressure decreased from 118.4 +/- 13.2 to 84.6 +/- 10.4 mm Hg after PTRA. Twenty seven (93.1%) of these 29 patients had benefical blood pressure response. Seventeen (58.6%) patients improved, 10 (34.5%) were cured, although 2 (6.9%) patients failed to respond to PTRA. Blood pressure response was better in FMD as compared to aortoarteritis group. Patients with unilateral RAS, discrete stenosis, and post-PTRA stenosis < or = 20% also identified good blood pressure response. CONCLUSION: Aortoarteritis is the most common cause of renovascular hypertension in South Asian children. PTRA is safe and highly effective and therefore should be the treatment of choice in pediatric renovascular hypertension.

Adolescent↗
PubMed1997

Retinoblastoma--a histologic and immunohistologic study.

Histopathology and various immunohistochemical markers were studied in 40 cases of human retinoblastoma. In histopathology, tumour type, extent and invasion were studied. In immunohistochemistry, both glial and neural markers were used to know the histogenesis of this tumour. The glial markers, glial fibrillary acidic protein and vimentin, were detected in retinal astrocytes and Muller's cells in normal retina and perivascular glia in retinoblastoma. The neural marker, neurone-specific enolase stained neurones in outer and inner nuclear layers in normal retina, Flexner-Wintersteiner rosettes in retinoblastoma and tumour cells is differentiated retinoblastoma. Another neural marker, neurofilament triplet polypeptide stained neurones in inner nuclear layer of normal retina and Flexner-Wintersteiner rosettes in well-differentiated retinoblastoma. These results support the view that retinoblastoma has predominantly neuronal origin.

Biomarkers, Tumor↗
PubMed1997

Black corneal ulcer.

PURPOSE: To discuss the etiology of an unusual finding of black color in a corneal ulcer. METHODS: Smear examination and culture of the corneal scraping were undertaken. RESULTS: The causative organism was found to be Aspergillus ruger. CONCLUSION: Black color in the corneal ulcer is attributed to Aspergillus niger.

Administration, Topical↗
PubMed1997

Impact of mode of delivery on maternal mortality in eclampsia.

Determinants of maternal mortality and causes of death pertaining to mode of delivery have been discussed. There were 23 deaths (case fatality rate of 7.2%) and maximum deaths occurred in intrapartum eclampsia (12 ie, 52.17%). Caesarean section was performed in 92 cases (28.7%) of which 4 women died (4.3%). Maternal mortality in cases who delivered vaginally was 7.1% (16 out of 225) and 3 cases died undelivered. Authors feel that at the referral centres early caesarean section in eclampsia may help in reducing maternal mortality.

Adult↗
PubMed1996

cis-acting elements within an RNA coliphage genome: fold as you please, but fold you must!!

Using an in vivo complementation system, we conducted a mutational analysis of the bacteriophage Q beta readthrough cistron. In the Q beta cDNA-containing plasmid, pQ beta m100, we constructed six defined Q beta deletion cDNA genomes, each missing between 86 and 447 nucleotides from within the readthrough cistron. These deletion plasmids were introduced into host cells that are constitutively supplied with Q beta readthrough protein from the plasmid pQ beta RT. Under these conditions, all six deletion genomes spontaneously generated phage particles, each exhibiting a characteristic plaque phenotype and virus forming potential. Isolated readthrough-defective phage particles were subsequently used to infect host cells that carried helper readthrough protein. Passaged viruses yielded both larger plaques and higher titers, compared with those of the parent phages. Sequence analysis revealed that the genomes of the passaged viruses had deleted additional regions of readthrough RNA sequence. We discuss the possibilities that (1) the disruption of a well-defined structural domain in Q beta RNA was selectively disadvantageous to phage infection, and that (2) the evolved viral populations were selected by virtue of their ability to restore critical integrity of short and/or long-range nucleotide interactions within this region of Q beta RNA.

Base Sequence↗
PubMed1996

Balloon mitral commissurotomy: an intraoperative assessment.

OBJECTIVE: Advances in balloon catheter technology have revolutionized the management of obstructive cardiovascular diseases. For lesions like mitral stenosis, balloon commissurotomy has emerged as an alternative to surgical relief showing definite functional benefits in a few clinical trials, albeit with variable results. Such variability necessitated objective evaluation of the efficacy of balloon mitral commissurotomy. METHODS: The balloon mitral commissurotomy was carried out in 11 patients suffering from isolated mitral stenosis, under vision in a surgical setting. All patients were in NYHA class III/IV. Initially single balloon was used for mitral commissurotomy followed by double balloon, before completing the mitral valvotomy with surgical instruments whenever required. The commissural split was measured by firmly stretching the two commissures using nerve hooks and measuring the distance between the two hooks with the help of a caliper. Assessment of balloon dilation was made by calculating exact percentage of residual commissural split following balloon dilation as compared with completed mitral valvotomy. The exact percentage of commissural split was thus obtained by subtracting residual commissural split following balloon dilation from commissural split obtained after surgical open mitral valvotomy. RESULTS: Complete commissurotomy using the balloon technique was possible in two (18.2%) patients. In the remaining nine (81.8%) patients, balloon expansion provided only 50% to 80% of commissural split and required instrumental completion with good results. CONCLUSIONS: Balloon mitral commissurotomy, by virtue of its circumferential force, helps to develop a good cleavage and attains good hemodynamic improvement which may be life saving in critical mitral stenosis in selected group of patients with pliable mitral leaflets and minimal subvalvular pathology.

Adolescent↗
PubMed1996

Computed tomography in miliary tuberculosis: comparison with plain films, bronchoalveolar lavage, pulmonary functions and gas exchange.

Computed tomography (CT) of the chest, pulmonary function tests, bronchoalveolar lavage (BAL) and arterial blood gas analysis were performed in 26 patients with non-HIV miliary tuberculosis (MTB). CT was repeated after treatment in 11 patients. Nodular lesions were characteristically seen on CT. CT showed discrete and fine nodules in five patients in whom the lesions appeared to be larger than miliary on chest X-rays. Coalescing nodular lesions were noted on chest X-rays (n = 7) and CT (n = 18). Consolidation (n = 6), cavitation (n = 4), fibrosis (n = 9) and air trapping (n = 14) were detected on CT only. During follow up, air trapping increased (n = 14) and in some patients it appeared for the first time (n = 2). Lymph node enlargement and calcification were seen on both chest X-rays (n = 9 and n = 3, respectively) and CT (n = 12 and n = 7, respectively). Pleural involvement was also seen in chest X-rays (n = 4) and CT (n = 5). Total lung capacity was higher in patients with a chest X-ray score > 10. Similarly a higher total cell count in BAL fluid was observed in patients with a CT score > 10. It is concluded from this study that CT is superior to chest X-rays in detecting nodular lesions, lymphadenopathy and air trapping in patients with MTB.

Adult↗
PubMed1996

AIDS awareness among nursing students of Delhi.

A total of 233 students of nursing school affiliated to a major hospital of Delhi were surveyed anonymously employing a predesigned, pretested and self-administered questionnaire. Although, 78.6 per cent students knew that AIDS stands for "Acquired Immuno-deficiency Syndrome," 15.5 per cent students were unaware of the fact that AIDS had reached India. Majority of them were aware of various aspects of HIV/AIDS. However, they also had few misconceptions particularly regarding HIV transmission. Contrary to our belief, only one-fourth students acquired AIDS information from scientific journals. One training session on AIDS conducted for a small group of students could not bring any significant change in their knowledge. Findings suggest organization of AIDS-training sessions at regular intervals from the very inception of nursing programme to impart complete and correct knowledge of these future Florence Nightingales regarding various aspects of HIV/AIDS and for removal of misconceptions.

Acquired Immunodeficiency Syndrome↗
PubMed1996

A retained intraretinal foreign body.

A patient with an 11-mm retained intraretinal foreign body is described. Absence of any history of trauma or foreign body entry with no obvious wound of entry and little damage to the ocular structures makes this case unusual.

Adult↗
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

Balancing photosynthetic light-harvesting and light-utilization capacities in potato leaf tissue during acclimation to different growth temperatures.

We investigated the effect of temperature during growth and development on the relationship between light-harvesting capacity, indicated by chlorophyll concentration, and light-utilization potential, indicated by light- and bicarbonate-saturated photosynthetic oxygen evolution, in Solanum tuberosum L. cv. Norland. Clonal plantlets were transplanted and grown at 20 degrees C for 2 weeks before transfer to 12, 16, 20, 24 and 28 degrees C for 6 weeks. After 4 weeks of the temperature treatments, leaf tissue fresh weights per area were one-third higher in plants grown at 12 degrees C vs those grown at 28 degrees C. Conversely, chlorophyll content per area in tissue grown at 12 degrees C was less than one-half of that of tissue grown at 28 degrees C at 4 weeks. Photosynthetic capacity measured at a common temperature of 20 degrees C and expressed on a chlorophyll basis was inversely proportional to growth temperature. Leaf tissue from plants grown at 12 degrees C for 4 weeks had photosynthetic rates that were 3-fold higher on a chlorophyll basis than comparable tissue from plants grown at 28 degrees C. These results suggest that the relationship between light-harvesting capacity and light-utilization potential varies 3-fold in response to the growth temperatures examined. The role of this response in avoidance of photoinhibition is discussed.

Acclimatization↗