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Biomedical subjects

Devendra Kumar

Publications and source records attributed to Devendra Kumar.

11 recordsLinked to original sources

Biomolecular immobilization on conducting polymers for biosensing applications.

A detail study on different aspects of biomolecule immobilization techniques on conducting polymers (CP) for applications in biosensors is described. Comparative studies are conducted in between the different mode of biomolecule immobilization techniques, viz. physical, covalent and electrochemical immobilization onto the conducting polymer films for the fabrication of electrochemical biosensors for clinical, food and environmental monitoring applications. This review focuses on the current status of biomolecule immobilization techniques on CP and their applications in the development of amperometric biosensors.

Adsorption↗

Does mycophenolate mofetil decrease the recurrent acute rejection in renal transplant recipients.

PURPOSE: Mycophenolate mofetil (MMF) has emerged as a valuable immunosuppression in renal transplant patients. However, it is expensive and cannot be used routinely in our population. MATERIAL AND METHODS: In a retrospective study, 60 renal transplant patients on MMF based triple immunosuppression were analysed. The indication for MMF was as rescue therapy after treatment of acute vascular rejection (Banff type-4, grade IIA, IIB and III) in all patients. However, 20 such patients also had associated chronic liver diseases. The patients were given 1.5-2.0 g MMF in two divided doses at least for 6 months, depending upon the tolerability, adverse effects and affordability, and followed-up at least for 1 year. The control group consisted of 60 cases of acute vascular rejection (Banff type-4, grade IIA, IIB and III) who were placed on cyclosporine, azathioprine and steroid based maintenance immunosuppressive regimen in same time frame. RESULTS: The incidence recurrent acute rejections in MMF group was 18% and 42% in control group (P < 0.005). The serum transaminases in all patients of the liver diseases became normal in 3-6 months. The incidence of opportunistic infections in MMF and control group were 22% and 11% respectively (P < 0.05). The MMF based regimen was two times more expensive. The 1 year patient and graft survivals between two groups were not statistically significantly different. CONCLUSION: The MMF based regimen significantly decreases the recurrent acute rejections. However, it is expensive and cannot be used routinely in all patients in Indian scenario.

Adult↗

Steps to reduce operative time in laparoscopic dismembered pyeloplasty for moderate to large renal pelvis.

OBJECTIVES: To describe the steps to reduce the operative time for laparoscopic dismembered pyeloplasty in ureteropelvic junction obstruction with moderate to large hydronephrosis. METHODS: Using a transperitoneal approach and three ports, pyelotomy was done proximal to the ureteropelvic junction, and the ureter was spatulated laterally before dismembering it. Using the three suture line technique, the first suture was taken at the distal end of the spatulated ureter outside-in to the most dependent part of the pelvis inside-out and left as such. The second suture was taken at the proximal end of the ureter outside-in to the corresponding site at the posterior wall of the pelvis and then continued distally to complete the posterior suture line. A double-J stent was placed in an antegrade way. The anterior wall was completed with the first suture, taking continuous bites. The third suture line was used to close the pelvis. The operative time was recorded from placing the patient in the lateral position to the closure of the last port. RESULTS: From January 2002 to January 2004, 24 patients underwent pyeloplasty performed by a single surgeon. The mean pelvic volume was 80.4 cm3 (range 70 to 110). The mean patient age was 24.5 years (range 5 to 57). The body mass index was 22.28 kg/m2 (range 20 to 25). The mean operative time was 120.4 minutes (range 80 to 160). Minor complications were noted in 3 patients. All patients showed improvement in symptoms and drainage after a mean follow-up of 17 months (range 10 to 28). CONCLUSIONS: These steps helped to reduce the operative time to close to that of open surgery, making laparoscopic pyeloplasty a more desirable alternative.

Adolescent↗

Safety profile and complications of transperitoneal laparoscopic pyeloplasty: a critical analysis.

PURPOSE: To critically assess the safety profile and complications of the transperitoneal approach to laparoscopic pyeloplasty at our center. PATIENTS AND METHODS: From January 2002 to January 2004, 92 patients with a mean age of 22.78 +/- 15.15 years (range 14 months-65 years) with primary (N = 90) or secondary (N = 2) ureteropelvic junction obstruction were treated by transperitoneal laparoscopic pyeloplasty and were evaluated for this study. Renal stones were present in eight patients. A double-J stent was placed antegrade in 50 patients and in the rest through cystoscopy. All patients were followed up clinically and by renal scan. RESULTS: Of the 92 cases (93 renal units), 6 were converted to open pyeloplasty. Dismembered pyeloplasty was performed in 59, Fengerplasty in 8, and Foley Y-V-plasty in 20 units. A crossing vessel was present in 15 units (16.12%). The mean estimated blood loss was 63.6 mL (range, 30-200 mL). The mean operative time was 179.4 minutes (range 80-350 minutes). Overall, 17 patients (18.4%) had complications. Six patients had paralytic ileus and another six had increased drain output, which delayed the hospital stay to 7 days. Pyelonephritis and port-site hernia occurred in one patient each. Four patients required ancillary procedures: ureteroscopy for a migrating stent (1), percutaneous antegrade stenting (1), and SWL for residual stone (2). The mean hospital stay was 4 days (range 2-7 days). Of the 87 units (86 patients), 81 (93.3%) have shown improvement in symptoms and drainage pattern on renal scan at a mean followup of 12 (3-27) months. CONCLUSION: The transperitoneal approach to pyeloplasty is safe and effective, although patients with large stone bulk and multiple stones should be considered for an alternative approach. The double-J stent should be checked carefully for proper placement. Hemostasis of the cut margin of the renal pelvis, watertight anastomosis, and adequate drainage should also be ensured.

Adolescent↗

Paraesophageal hernia in the neonatal period: suspicion on chest X-ray.

The paraesophageal hernia is rarely seen in the neonatal period. Presentation in neonatal period can be confused with the possibility of esophageal atresia or esophageal web. The upper gastrointestinal tract contrast study is diagnostic in this disease, but careful viewing of the plain X-ray of the chest can also lead to suspicion of the diagnosis. Two neonates with para-esophageal hernia are reported, one with the mesenterico-axial volvulus and the second neonate without volvulus.

Follow-Up Studies↗

Cytoprotective activity of Amla (Emblica officinalis) against chromium (VI) induced oxidative injury in murine macrophages.

The cytoprotective and immunomodulating properties of Emblica officinalis (Amla) against chromium (VI) induced oxidative damage are reported. Chromium (VI) at 1 micro g/mL concentration was highly cytotoxic. It enhanced free radical production and decreased reduced glutathione (GSH) levels and glutathione peroxidase (GPx) activity in macrophages. The presence of Amla resulted in an enhanced cell survival, decreased free radical production and higher antioxidant levels similar to that of control cells. Further, chromium (VI) treatment resulted in decreased phagocytosis and gamma-interferon (gamma-IFN) production while Amla inhibited chromium induced immunosuppression and restored both phagocytosis and gamma-IFN production by macrophages significantly.

Animals↗

Infected esophageal duplication cyst simulating empyema.

Duplications of the esophagus are the second most common duplication of the gastrointestinal tract. The children with esophageal duplication cyst usually present with respiratory distress or as asymptomatic thoracic mass found on incidental chest x-ray. We report a case of infected esophageal duplication cyst initially confused with empyema in a two years old boy.

Child, Preschool↗

Antioxidant effect of beta-carotene on hypoxia induced oxidative stress in male albino rats.

Hypoxia is known to induce oxidative stress in organisms leading to tissue injury. In the present study beta-carotene (BC) given at 10 mg/kg body weight (BW) in reducing the oxidative stress induced by hypoxia was evaluated on male albino rats. Hypoxia exposure caused an increase in malondialdehyde (MDA) levels in plasma and tissues, a concurrent decrease in blood glutathione (GSH), glutathione peroxidase (GPx), plasma protein and plasma BC content. Hemoglobin concentration, Red blood corpuscles (RBC) and White blood corpuscles (WBC) count were also increased under hypoxia. BC supplementation reversed the trend, inducing a significant decrease (P<0.05) in MDA and subsequent increase in plasma and tissue GSH levels in animals exposed to hypoxia. Blood GPx and plasma protein also increased significantly in BC supplemented animals. BC supplementation did not alter the changes in Hb concentration, RBC and WBC count. BC has potent antioxidant activities in reducing the oxidative stress induced by hypobaric hypoxia.

Animals↗

Cyto-protective and immunomodulating properties of Amla (Emblica officinalis) on lymphocytes: an in-vitro study.

The fruits extracts of Emblica officinalis (Amla) has been reported to have strong anti-oxidant properties. There is a paucity of studies on the immunomodulatory properties of fruit extracts of Amla in immuno-compromised states, with the emphasis on lymphocytes. Therefore, the aim of the study was to determine the anti-oxidant and immunomodulatory properties of Amla using chromium (VI) as an immunosuppressive agent. Chromium (Cr) treatment results in enhanced cytotoxicity, free radical production, lipid peroxidation and decreased glutathione peroxidase (GPx) activity and diminished glutathione (GSH) levels. There was a significant inhibition of both lipopolysaccharide and concanavalin-A-stimulated lymphocyte proliferation. Chromium also inhibited Con A stimulated interleukin-2 and gamma-interferon production significantly. Further, there was enhanced apoptosis and DNA fragmentation in the presence of Cr. Amla significantly inhibited Cr-induced free radical production and restored the anti-oxidant status back to control level. Amla also inhibited apoptosis and DNA fragmentation induced by Cr. Interestingly, Amla relieved the immunosuppressive effects of Cr on lymphocyte proliferation and even restored the IL-2 and gamma-IFN production considerably.

Adjuvants, Immunologic↗