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Biomedical subjects

R Kapoor

Publications and source records attributed to R Kapoor.

At least 19 recordsLinked to original sources
PubMed1999

Optimum duration of splinting after endopyelotomy.

OBJECTIVE: Endopyelotomy is a well-accepted modality of treatment for pelviureteral junction (PUJ) obstruction, but the time period of stenting is debatable. The present study was aimed at evaluating the optimum duration and effectiveness of splinting after endopyelotomy. PATIENTS AND METHODS: Twenty-nine consecutive patients with primary PUJ obstruction were randomized to have an external splint (for economic reasons) for 2 weeks or 4 weeks. Thirteen patients in each group were available for evaluation. The groups were comparable in age, sex, symptoms, and preoperative glomerular filtration rate (GFR). All patients underwent antegrade endopyelotomy with placement of an 8F-12F polyethylene splint across the PUJ. A nephrostogram was performed after removal of splint at 2 or 4 weeks. Nondraining units were managed by putting in a 6F double-J stent for 6 weeks and considered failures. Patients were evaluated at 3, 6, and 12 months for symptomatic improvement, change in GFR, and drainage pattern on a diuretic renogram. RESULTS: At 1 year, a nonobstructed curve pattern was seen in 70% and improvement in GFR in 54% of the patients in the 2-weeks group, whereas in the 4-weeks group, these values were 54% and 39%, respectively. All patients in the 4-weeks group and 90% of those in the 2-weeks group were symptom free at 1 year of follow-up. Morbidity in terms of tube-related complications was comparable. CONCLUSION: Two weeks of splinting is as effective as 4 weeks in the successful outcome of endopyelotomy.

Adolescent↗
PubMed1999

Demyelination: the role of reactive oxygen and nitrogen species.

This review summarises the role that reactive oxygen and nitrogen species play in demyelination, such as that occurring in the inflammatory demyelinating disorders multiple sclerosis and Guillain-Barré syndrome. The concentrations of reactive oxygen and nitrogen species (e.g. superoxide, nitric oxide and peroxynitrite) can increase dramatically under conditions such as inflammation, and this can overwhelm the inherent antioxidant defences within lesions. Such oxidative and/or nitrative stress can damage the lipids, proteins and nucleic acids of cells and mitochondria, potentially causing cell death. Oligodendrocytes are more sensitive to oxidative and nitrative stress in vitro than are astrocytes and microglia, seemingly due to a diminished capacity for antioxidant defence, and the presence of raised risk factors, including a high iron content. Oxidative and nitrative stress might therefore result in vivo in selective oligodendrocyte death, and thereby demyelination. The reactive species may also damage the myelin sheath, promoting its attack by macrophages. Damage can occur directly by lipid peroxidation, and indirectly by the activation of proteases and phospholipase A2. Evidence for the existence of oxidative and nitrative stress within inflammatory demyelinating lesions includes the presence of both lipid and protein peroxides, and nitrotyrosine (a marker for peroxynitrite formation). The neurological deficit resulting from experimental autoimmune demyelinating disease has generally been reduced by trial therapies intended to diminish the concentration of reactive oxygen species. However, therapies aimed at diminishing reactive nitrogen species have had a more variable outcome, sometimes exacerbating disease.

Animals↗
PubMed1998

Parainfectious conus myelitis.

We describe electroclinical and imaging features of a peculiar type of parainfectious myelitis that selectively involves the conus/epiconus region of the spinal cord. Twelve patients of parainfectious myelitis with MRI evidence of inflammatory lesions in the conus/epiconus region of the spinal cord were studied. All patients underwent full clinical and electrophysiological evaluation along with MRI of the spine. MRI included axial images at the site of lesion. All patients had a unique clinical presentation with urinary symptoms. Careful clinical examination revealed minimal sensorimotor dysfunction in the lower lumbar and sacral segments, which remained unnoticed by most of the patients; three female patients had no sensorimotor deficit. The motor paralysis recorded in four patients was flaccid and areflexic. The sensory level was inconspicuous as it was in the leg area corresponding to the lumbar and sacral spinal segments. Sensory loss was significantly more in the perineal region in those seven patients who had MRI evidence of inflammatory lesion in conus medullaris; two patients had maximum sensory loss in lumbar dermatomal distribution, which corresponded with the focal segmental myelitis involving 'epiconus'. MRI done in the sagittal plane was either normal or only 'suggestive' of myelitis in most of the patients and the inflammatory lesions were much more visible in the axial plane. The lesions predominantly involved central gray matter with spread to adjoining white matter in nine patients; in three patients with pure bladder involvement, lesions were confined to lateral gray matter of the conus medullaris. Our findings indicate that parainfectious myelitis (PIM) selectively involving conus medullaris is an important cause of unexplained acute or sub-acute urinary symptoms in adolescent and adult patients. In suspected cases, MRI must include axial images of the conus-epiconus region, as sagittal images may not always reveal the lesion. Due to initial presentation with urinary symptoms, absent or minimal sensory-motor signs, no transverse level over the trunk and unique MRI features, this condition may be called parainfectious conus myelitis (PICM).

Acute Disease↗
PubMed1998

Sodium, potassium-activated adenosine triphosphatase activity is impaired in the guinea pig pancreatic duct system in streptozotocin-induced diabetes.

In patients with type I diabetes mellitus, clinical studies have demonstrated decreased secretion of pancreatic juice by the pancreatic excretory duct system. The cause of this decrease is unknown, but could involve changes in initial signal transduction pathways or one or more of the electrolyte transport components that subserve regulated fluid secretion. We have compared responsiveness to secretin in pancreatic ducts isolated from healthy and diabetic Hartley guinea pigs and also have compared the expression of CFTR and Na+, K(+)-ATPase in these two groups, as the activities of these two proteins are essential for secretion of pancreatic juice. The increases in cyclic AMP levels evoked by exposure to either 0.1 nM or 0.1 microM secretin were not significantly different in pancreatic ducts isolated from healthy and diabetic guinea pigs nor were levels of CFTR or Na+, K(+)-ATPase expression. By contrast, Na+, K(+)-ATPase activity in pancreatic ducts isolated from diabetic guinea pigs was decreased by 70%, suggesting a change in the enzyme's catalytic properties in the diabetic tissues. The observed decrease would be expected to seriously compromise the production of pancreatic juice.

Animals↗
PubMed1998

Dose rate correction in medium dose rate brachytherapy for carcinoma cervix.

PURPOSE: To establish the magnitude of brachytherapy dose reduction required for stage IIB and III carcinoma cervix patients treated by external radiation and medium dose rate (MDR) brachytherapy at a dose rate of 220+/-10 cGy/h at point A. MATERIALS AND METHODS: In study-I, at the time of MDR brachytherapy application at a dose rate of 220+/-10 cGy/h at point A, patients received either 3060 cGy, a 12.5% dose reduction (MDR-12.5), or 2450 cGy, a 30% dose reduction (MDR-30), to point A and they were compared to a group of previously treated LDR patients who received 3500 cGy to point A at a dose rate of 55-65 cGy/h. Study-II was a prospective randomized trial and patients received either 2450 cGy, a 30% dose reduction (MDR-II (30)) or 2800 cGy, a 20% dose reduction (MDR-II (20)), at point A. Patients were evaluated for local control of disease and morbidity. RESULTS: In study-I the 5-year actuarial local control rate in the MDR-30 and MDR-12.5 groups was 71.7+/-10% and 70.5+/-10%, respectively, compared to 63.4+/-10% in the LDR group. However, the actuarial morbidity (all grades) in the MDR-12.5 group was 58.5+/-14% as against 34.9+/-9% in the LDR group (P < 0.05). Similarly, the grade III and IV morbidity also in the MDR-12.5 group was 12.5+/-9% as against 5.3+/-5% in the LDR group (P < 0.05). No statistically significant difference in morbidity was seen between the MDR-30 and LDR groups. In study-II the 3-year actuarial local control rate in the MDR-II (30) and MDR-II (20) groups was 66.6+/-10% and 74.8+/-9%, respectively. There was a significant correlation between the rectal BED received and the percentage of patients developing rectal morbidity. Only 10% of patients receiving a rectal BED of (100 < 120) Gy3 developed complication as against 62.5% of those receiving a rectal BED of (140 < 160) Gy3 (chi2 = 46.43; P < 0.001). CONCLUSION: We suggest that at a dose rate of 220+/-10 cGy/h at point A the brachytherapy dose reduction factor should be around 30%, as suggested by radiobiological data, to keep the morbidity as low as possible without compromising the local control rates.

Brachytherapy↗
PubMed1998

Intramuscular haemangioma of head and neck region.

Intramuscular haemangiomas are rare benign haemangiomas occurring within the skeletal muscle. These are uncommon tumours in the head and neck region and occur most frequently on the trunk and extremities. Fewer than 80 cases of intra-muscular haemangioma in the head and neck region have been reported in the literature. A case of intramuscular haemangioma of the sternocleidomastoid muscle is presented. The review of occurrence and natural history of such tumours is described and clinical and radiological presentation, histological classifications and treatment modalities are discussed.

Adolescent↗
PubMed1998

Randomized, double-blind placebo-controlled trial of coenzyme Q10 in patients with acute myocardial infarction.

The effects of oral treatment with coenzyme Q10 (120 mg/d) were compared for 28 days in 73 (intervention group A) and 71 (placebo group B) patients with acute myocardial infarction (AMI). After treatment, angina pectoris (9.5 vs. 28.1), total arrhythmias (9.5% vs. 25.3%), and poor left ventricular function (8.2% vs. 22.5%) were significantly (P < 0.05) reduced in the coenzyme Q group than placebo group. Total cardiac events, including cardiac deaths and nonfatal infarction, were also significantly reduced in the coenzyme Q10 group compared with the placebo group (15.0% vs. 30.9%, P < 0.02). The extent of cardiac disease, elevation in cardiac enzymes, and oxidative stress at entry to the study were comparable between the two groups. Lipid peroxides, diene conjugates, and malondialdehyde, which are indicators of oxidative stress, showed a greater reduction in the treatment group than in the placebo group. The antioxidants vitamin A, E, and C and beta-carotene, which were lower initially after AMI, increased more in the coenzyme Q10 group than in the placebo group. These findings suggest that coenzyme Q10 can provide rapid protective effects in patients with AMI if administered within 3 days of the onset of symptoms. More studies in a larger number of patients and long-term follow-up are needed to confirm our results.

Angina Pectoris↗
PubMed1998

Supplementary effect of spirulina on hematological status of rats during pregnancy and lactation.

The effect of Spirulina on iron status was assessed based on hemoglobin, packed cell volume, serum iron, total iron binding capacity and ferritin levels of rats during pregnancy and lactation. Rats were fed 5 different kinds of diets (casein, Spirulina, wheat gluten, Spirulina + wheat gluten, Spirulina without additional vitamins and minerals) each providing 22 percent protein. Diets containing Spirulina alone or in combination with wheat gluten resulted in significantly higher iron storage and hemoglobin contents than casein and wheat gluten diets during the first half of pregnancy and lactation. Wheat gluten diet result in the smallest increase in hemoglobin levels and iron stores compared to other diets. The values of serum iron and iron binding capacity remained unchanged with different diets. Spirulina appears to be effective in improving the iron status of rats during pregnancy and lactation.

Animals↗
PubMed1998

Relief of urinary tract obstruction in tuberculosis to improve renal function. Analysis of predictive factors.

OBJECTIVE: To assess the effect of the relief of obstruction on the ultimate function of the affected renal unit in urinary tuberculosis, and to identify predictors of functional recoverability. PATIENTS AND METHODS: Of a total of 82 patients with urinary tuberculosis presenting over 7 years, 38 with evidence of upper tract obstruction were analysed. All patients were assessed with pre-operative excretory urography, urinary mycobacterial cultures and serum chemistry. Patients with subnormally functioning kidneys were assessed with baseline renal scans. Preliminary intervention in the form of JJ stenting or percutaneous nephrostomy (PCN) was carried out in patients with reasonable renal function. Function was reassessed after 4 weeks to detect evidence of improvement and factors which could affect the outcome were determined. RESULTS: Thirty-eight patients had documented upper tract obstruction, of whom six had bilateral obstruction (total of 44 renal units). Ten renal units were not functioning at presentation, with a mean (SD) glomerular filtration rate (GFR) of 3.0 (5.73) mL/min, and no preliminary intervention was performed. In the remaining 34, preliminary intervention was carried out before definitive surgery (JJ stenting in 14, PCN in 15 and PCN followed by antegrade JJ stenting in five); 21 of these renal units were salvaged but 13 were lost despite overcoming the obstruction. Three of the 13 units deteriorated from having acceptable pre-treatment GFRs to becoming non-functional. Good renal cortical thickness, a low grade of renal involvement (Semb 1 or 2), the presence of more distal disease in the form of ureteric stricture and a GFR of > 15 mL/min were good predictors of renal recovery after diversion. CONCLUSIONS: The loss of some renal units seems inevitable in patients with urinary tuberculosis, despite advances in chemotherapy. Having pre-operative predictors of renal recovery may ensure optimal patient selection, thereby reducing the number of procedures and economic burden on the patient who does not require intervention.

Adult↗
PubMed1998

Effects of intravenous methylprednisolone on outcome in MRI-based prognostic subgroups in acute optic neuritis.

Treatment of acute optic neuritis with steroids has been shown to hasten visual recovery without affecting the final degree of recovery. However, MRI-clinical studies indicate that patients with long optic nerve lesions, particularly those that involve the nerve within the optic canal, may have a worse prognosis for recovery of vision. Partly because such lesions could lead to swelling and subsequent ischemic optic nerve damage, steroids could have a selective beneficial effect on this subgroup of patients. The present randomized trial was designed to test this possibility. Sixty-six patients with acute optic neuritis received IV saline or IV methylprednisolone. The clinical, psychophysical, electrophysiologic, and MRI outcomes were assessed after 6 months. Patients with short lesions presented earlier than those with long lesions (involving three or more 5-mm-thick slices of any part of the optic nerve, as well as its intracanalicular portion), and lesion length was significantly less in patients presenting within a week of onset of symptoms. Lesions also tended to lengthen during follow-up in individual patients. Treatment did not limit lesion length in either the long or short lesion subgroup and had no significant effect on final visual outcome. We conclude that steroids do not improve visual outcome or lesion length in patients with acute optic neuritis.

Acute Disease↗
PubMed1997

Immuno-localization of kynurenine aminotransferase (KAT) in the rat medulla and spinal cord.

In the mammalian brain, kynurenine aminotransferase (KAT) is pivotal to the synthesis of kynurenic acid, a preferential antagonist at the strychnine-insensitive NMDA-glycine site. As NMDA receptors are involved in autonomic function, we have examined the immunohistochemical localization of KAT in the medulla and spinal cord of the rat. KAT immunoreactivity (KAT-li) was found throughout these areas, in both glia and neurons. Unlike the mainly astrocytic localization in forebrain structures, KAT-li was predominantly neuronal, notably in areas important for blood pressure and heart rate regulation: ventral medulla, nucleus ambiguus, nucleus of the solitary tract and intramediolateral cell column of the spinal cord. The presence of KAT in these nuclei supports a neuromodulatory role for kynurenic acid in NMDA-mediated autonomic function.

Animals↗