PubMed Health⌕ Search

Biomedical subjects

V Bhatnagar

Publications and source records attributed to V Bhatnagar.

At least 127 records · Page 7Linked to original sources
PubMed1998

Characterization of Mg2+-ATPase activity in isolated B16 murine melanoma melanosomes.

B16 murine melanoma melanosomes were purified using sucrose density gradient centrifugation. ATPase activity was evaluated in presence of specific ATPase inhibitors, and compared with melanosome ATP-driven proton translocating activity in the melanosome. Mg2+ dependent ATPase activity was greatly inhibited (82%) by the specific inhibitors of vaculor proton translocating ATPase; Cis-didimethylsulfoxide dichloroplatinum (II) at approximately 90 microM and bafilomycin AI at two fold higher concentrations. Less inhibition, about 30 and 45% was obtained with N, N1-dicyclohexylcarbodiimide and N-ethylmaleimide, and the maximal effect occurred in the 50-100 microM and 0.1-1.5 mM ranges, respectively. These drugs at similar concentrations also inhibited the proton pumping activity to the same extent as observed for ATPase activity and half-maximal inhibition of each activity was found at nearly similar concentrations. Carbonylcyanide p-trifluoromethoxyphenyl hydra zone (FCCP) prevented ATP from setting up a pH gradient across the melanosomal membrane but stimulated Mg2+ ATPase activity significantly. Replacement of 5 mM Mg2+ with equimolar Ca2+ brought about a 60% inhibition in divalent cation-dependent ATPase- activity, and an 85% inactivation of ATP-linked melanosomal H+ pump activity. In the presence of optimal concentrations of Ca2+ and Mg2+ ATPase activity was similar to that seen in a Mg2+ medium. In Ca2+ medium ATPase activity was inhibited by CDDP and stimulated by FCCP, however these effects were two to three fold less than those observed in Mg2+ medium. FCCP failed to stimulate ATPase activity in CDDP- supplemented medium, thus suggesting that the same ATPase activity fraction was sensitive to both CDDP and FCCP. Mg2+-ATPase activity, like the proton-pump was anion dependent. The lowest activity was recorded in F medium, and increased in the order of F < So4(2-) < CL- = Br-. These results show that the ATPase activity may be related to the melanosomal proton pump.

Animals↗
PubMed1998

Bilateral Wilms tumor: an eleven year experience.

Over the last 11 years, 101 patients of Wilms tumor were treated at our hospital. Of these, 7 had bilateral Wilms tumors (BWT). The first two patients were referred in terminal stages and died. Of the latter five, three have survived while one is on treatment. One patient succumbed to liver metastasis, he had stage III disease on one side and was irregular in his chemotherapy protocol. Remarkably, one of the survivors was cured even after developing vertebral metastasis, retroperitoneal recurrence and bilateral lung metastasis. Part of the success was due to "salvage chemotherapy regimens" using Cis-plantinum, ifosphamide and VP-16. Flow cytometric analysis of DNA ploidy performed on only three of the five patients showed that two tumors were aneuploid and one was diploid. Spectacular cure rates can be achieved in BWT by renal conservation surgeries and effective chemotherapy. The use of "salvage chemotherapeutic regimes" and the study of DNA ploidy is being highlighted.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

Mesenteric neurofibroma in von Recklinghausen's disease.

The authors report the case of a 6-year-old boy admitted for surgical removal of a 5- x 4-cm neurofibroma over the left wrist. On routine clinical examination a mobile firm, nodular, central abdominal mass was discovered. At laparotomy a tumor (measuring 7 x 5 x 3 cm) arising from the ileal mesentery was found. Complete excision of the mass together with a segment of ileum, followed by end-to-end bowel anastomosis was performed. Histological examination showed that the main elements of the mass consisted of wavy, long-spindled cells that crossed irregularly (pallisading negative). Special stains and immunocytochemistry for S-100 protein confirmed the mass to be a neurofibroma of the mesentery. The patient had an uneventful postoperative course and no signs of recurrence or fresh tumor have been recognized in the 4 years since his operation.

Anastomosis, Surgical↗
PubMed1997

Genitourinary tuberculosis in pediatric surgical practice.

BACKGROUND: Genitourinary tuberculosis (GUTB) has been reported to account for 20% to 73% of all cases of extrapulmonary tuberculosis in the general population but is much rarer in children. GUTB is a form of secondary tuberculosis with vague symptoms. Surgical intervention is required in a minority of cases. METHODS: Nine cases of genitourinary tuberculosis (GUTB) were diagnosed and treated from 1988 to 1995. The age of the patients ranged from 5 to 12 years. There were five boys and four girls. Presenting features were diverse and included gross hematuria in 44% of cases and epididymoorchitis in 22% of cases. Rarer presenting features included acute renal failure, staghorn calculus, and pyonephrosis. Associated or past history of tuberculosis was present in three patients. Conclusive diagnosis was made on the basis of isolation of mycobacterium tuberculosis, histopathology, or cystoscopy in eight patients, whereas one patient was given a therapeutic trial based on clinical manifestations. RESULTS: Response to antitubercular drug therapy was gratifying. Excisional surgery in the form of nephrectomy was needed in one patient, whereas another underwent bilateral ureteric replacement with ileal loops for multiple ureteric strictures. CONCLUSIONS: The wide variety of presenting features and pathological lesions that result from GUTB are emphasized. The diagnosis of GUTB must be suspected in patients who present with hematuria (gross or otherwise), epididymoorchitis, and patients with long segment or multiple ureteric strictures. In view of the anticipated resurgence in tuberculosis caused by the prevalence of aquired immunodeficiency syndrome the pediatric urologist must be aware of the pathophysiology and clinical spectrum of this disease.

Antitubercular Agents↗
PubMed1996

Hepatic artery thrombosis after liver transplantation in children under 5 years of age.

The incidence of hepatic artery thrombosis (HAT) following orthotopic liver transplantation in children varies from 4% to 26% and represents a significant cause of graft loss. The purpose of this study was to analyze the risk factors for HAT following liver transplantation in children less than 5 years old. Seventy-three transplants were performed in 62 children under 5 years of age, including 16 for acute hepatic failure, 46 for chronic liver disease, and 11 retransplants. Twenty-four whole liver grafts (WLG) and 49 reduced size grafts (3 right lobes, 16 left lobes, and 30 left lateral segments) were transplanted. The recipient common hepatic artery was used to provide arterial inflow in 22 transplants and an infrarenal iliac conduit in 51 transplants. The overall incidence of HAT was 8 out of 73 transplants (11%). The cold ischemia time (14.3 +/- 3.03 hr) in this group was significantly longer than the cold ischemia time for those without HAT (11.7 +/- 3.94 hr) (P = 0.049). The incidence of HAT for whole and reduced grafts was 25% (6/24) and 4% (2/49), respectively (P = 0.01). HAT occurred in 6 of 22 grafts (27.3%) revascularized from the recipient common hepatic artery, compared with 2 of 51 grafts (3.9%) using an infrarenal arterial conduit (P = 0.008). The combination of recipient hepatic arterial inflow to a WLG resulted in HAT in 50% (6/12), whereas there were no cases of HAT with an iliac conduit to a WLG (P = 0.01). Of the eight patients with HAT, five are alive (median follow-up, 20 months; range, 7-27 months). Five patients were retransplanted, three within the first 2 weeks and two at 4 and 5 months for abnormal liver function in association with clinical and histological features of chronic rejection. Prolonged cold ischemia time and use of a whole graft with recipient hepatic arterial inflow are risk factors for developing HAT. The use of reduced size grafts and infrarenal iliac arterial conduits are associated with a low incidence of HAT.

Child, Preschool↗
PubMed1996

Congenital diaphragmatic hernia with ipsilateral eventration: a report of two cases.

We report herein the cases of two patients in whom the unusual association of a diaphragmatic hernia with eventration of the diaphragm on the same side were confirmed. Although various recognized patterns of malformations have been described in children with diaphragmatic defects or eventration, to the best of our knowledge, this association has never been reported before. Following our case reports, the literature on this unusual topic is reviewed and a discussion on the possible pathogenesis is presented.

Child↗
PubMed1996

Coins can be safely removed from the esophagus by Foley's catheter without fluoroscopic control.

OBJECTIVE: Evaluate safety of the procedure of removing coins from the esophagus in children by Foley's catheter without fluoroscopic control. DESIGN: Retrospective case-series. SETTING: Tertiary care referral hospital, during 1992-94. SUBJECTS: 302 consecutive children with coins impacted in the esophagus who presented to the hospital. RESULTS: Coins were successfully removed in 283 (93.7%) children including 2 cases in whom the removal was difficult. CONCLUSIONS: Foley's catheter may be used for removed of impacted esophageal coins, even without fluoroscopic control. The technique is effective and safe.

Catheterization↗