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Biomedical subjects

A Chaudhary

Publications and source records attributed to A Chaudhary.

At least 91 records · Page 5Linked to original sources
PubMedDate not supplied

Elective surgery for corrosive-induced gastric injury.

Gastric cicatrization is a well recognized late sequela of corrosive gastric injury, but the optimum timing and type of surgery for this complication are still unclear. Over a 7-year period (1988-1994) 34 patients underwent elective surgery for gastric lesions secondary to corrosive ingestion. A total of 18 (53%) patients had an associated esophageal stricture and presented with dysphagia, 15 (44%) patients had features of gastric outlet obstruction, 6 (18%) had diffuse gastric injury, and 28 (82%) had a segmental lesion. A tube jejunostomy was done in 23 (68%) patients to improve nutrition and resulted in a significant increase in weight and in the serum protein level after 8 weeks of tube feeding. Elective surgery was performed 3 to 24 months (average 7 months) after ingestion of the corrosive substance. Gastric resection was done in 20 (59%) patients and gastrojejunostomy (without vagotomy) in 11 (32%); at follow-up the latter group did not exhibit development of a stomal ulcer. In patients with an associated esophageal stricture, endoscopic dilatation was successful in 89% patients and simplified the surgical approach. In conclusion, the success of surgery for corrosive-induced gastric injury depends on selecting the right procedure and intervening at the appropriate time.

Acids↗
PubMedDate not supplied

Screening cascade and development of potential Positron Emission Tomography radiotracers for mGluR5: in vitro and in vivo characterization.

PURPOSE: Use of mGluR5 receptor radiotracers to determine whether an in vitro binding assay is able to predict how good a radiotracer is likely to be in imaging receptor in the central nervous system (CNS) via positron emission tomography (PET). PROCEDURES: Saturation and equilibrium competition studies in rat and rhesus membranes were used to determine receptor concentrations and tracer affinities. In addition, specific binding of metabotropic receptor subtype 5 (mGluR5) radioligands in rhesus and rat brain sections was determined using a "no-wash protocol," and the in vivo binding signal in rats was determined using micro-PET. RESULTS: Affinity values were determined for a series of mGluR5 antagonists (1-5) and ranged from 0.1 to 11 nM in rat. A previously reported "no-wash protocol" was then employed to determine specific binding in tissue sections following a 20-min incubation, and the regional distribution of these mGluR5 radiotracers determined in rat brain via autoradiography. The analogs 1b, 2b, 3b, and 4b, but not 5b, displayed good signal-to-noise ratios under these conditions with high density of binding in caudate, cortex, and hippocampus and lower density in cerebellum. With this information it was predicted that 1c, 2c, 3b, and 4b would display measurable signal-to-noise ratios in vivo, and that the larger in vitro signals for 3b and 4b would translate to 3b and 4b yielding the best in vivo signals. These predictions were investigated using micro-PET imaging in rat. Compound 1c showed a rapid wash-in and rapid wash-out profile in rat brain. Compound 2c showed similar signal-to-noise ratio as 1b, but slower washout. Compounds 3b and 4b showed the best signal-to-noise ratio in vivo, while 5b did not provide a significant signal, as predicted. In vivo occupancy estimates for 2-methyl-6-(phenylethynyl)-pyridine (MPEP) following intravenous administration were determined using radiolabeled compounds 1c, 2c, and 3b; they were essentially the same and were on the order of 1 mg kg(-1) (ID(50)). CONCLUSIONS: An in vitro screen of several mGluR5 tracers was used to rapidly predict whether radiolabeled mGluR5 analogs would be useful as PET radiotracers. Results provided an extension to previously reported data. Two of the four radiotracers with the best in vitro "no-wash" results also showed the best potential as measured noninvasively using micro-PET.

Animals↗
PubMedDate not supplied

Photoaffinity analogue for the anti-inflammatory drug alpha-trinositol: synthesis and identification of putative molecular targets.

alpha-Trinositol (alpha T), or Ins(1,2,6)P3, is a semisynthetic inositol trisphosphate produced commercially by the partial degradation of phytic acid with phytase. The molecular targets mediating the mechanism of action of this novel anti-inflammatory, analgesic, and antivasoconstrictive drug are unknown. A new photoaffinity analogue, 4-[3H]BZDC-alpha T, has been prepared in which the [3H]-p-benzoyldihydrocinnamoyl ([3H]BZDC) photophore is tethered through an O-(5-aminopentanoyl) linkage to the 4-OH of alpha T. Photoaffinity labeling experiments with two human tissues, umbilical cord vascular smooth muscle cells and platelet membranes, revealed proteins that were selectively labeled by 4-[3H]BZDC-alpha T. Thus, co-incubation with alpha T but not with Ins(1,3,4,5)P4 during photolysis competitively displaced labeling of a 55 kDa platelet protein. In vascular epithelial cells, alpha T and Ins(1,3,4,5)P4 both displaced labeling of a 55 and 43 kDa proteins. The identification of putative protein targets for alpha T in smooth vascular tissue may have important implications in elucidation of the mechanism of action of this unusual drug.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMedDate not supplied

Gastric outlet obstruction in carcinoma gall bladder.

BACKGROUND: Gastric outlet obstruction is occasionally reported to occur in advanced gall bladder malignancy and may require palliative surgery. A review of 39 patients who required gastroenterostomy for symptomatic or incipient gastric outlet obstruction in carcinoma gall bladder is presented. METHODS: This retrospective review included 24 women and 15 men over nine years who underwent gastrojejunostomy for locally advanced neoplasms of the gall bladder. RESULTS: Twenty two patients with carcinoma gall bladder had symptomatic gastric outlet obstruction whereas in 17 patients gastrojejunostomy had been performed for intraoperatively assessed impending obstruction. Thirty-four patients had concomitant jaundice. In most cases, there was obstruction of the first two parts of the duodenum, mostly by direct tumoral infiltration (64%). All patients underwent anterior gastrojejunostomy, with billoenteric bypass in 15 patients. There were two postoperative deaths. Eight patients developed postoperative delayed gastric emptying; all settled on conservative management, though two patients had recurrent refractory vomiting. Thirty patients had no vomiting till a follow up ranging from 36 days to 11 months. CONCLUSIONS: Gastric outlet obstruction may frequently complicate gall bladder cancer and a satisfactory palliation can be achieved in most patients by gastrojejunostomy.

Adult↗
PubMedDate not supplied

Duodenal villous adenoma.

Duodenal villous adenomas are extremely rare (1/5th of small bowel tumors). In view of their strategic position and risk of malignancy, they require definitive management in specialized care units. We report a case of a 35 year old female patient with a large duodenal (5 cm) villous adenoma causing intussusception of duodenum (a phenomenon rare because of its anatomic location & fixation).

Adenoma, Villous↗
PubMedDate not supplied

Ultrasonographic evaluation of common duct diameter in pre and post cholecystectomy patients.

Thirty four patients with gall bladder disease and normal common duct were investigated prospectively by ultrasonography just before cholecystectomy and at periodic intervals of 1 months, 2 months, 3 months and once in 4-6 months after cholecystectomy. The pre and post cholecystectomy common duct diameters were measured at each visit and compared with each other to determine the statistical significance. No significant change (p > 0.05) occurred in common duct diameter following cholecystectomy.

Adolescent↗
PubMedDate not supplied

Complicated choledochal cysts.

Choledochal cysts have a potential for causing a variety of complications. This article presents the incidence, types, and presentation of complications in patients with choledochal cysts and the results of surgery in these patients. Prospectively collected data of 81 patients with choledochal cysts treated at a tertiary care center were retrospectively analyzed. Sixteen (20% of surgical patients; 100% of study group) patients were found to have a complicated choledochal cyst that either manifested as an atypical presentation or necessitated a change in the treatment planning. Eight (50%) of these patients had complications of infective nature, and another 8 (50%) had noninfective complications. Fifteen (94%) patients with complications were adults and 11 (63%) patients had Todani type-IVa cysts; a cystic type of intrahepatic component in 10 patients. Five (31%) patients had undergone prior cystenteric drainage operations. Excision of the choledochal cyst was possible in 14 (88%) patients under both emergency and elective situations; cyst excision was performed in the second stage after an initial external drainage procedure in two of these patients. There was no mortality and no major postoperative complications. Complications of choledochal cysts are more likely in adult patients and in those with both intra- and extrahepatic cysts (Todani type-IVa). Despite the presence of complications, the choledochal cyst can be safely excised in a majority of patients.

Adolescent↗