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Biomedical subjects

P Chandrasoma

Publications and source records attributed to P Chandrasoma.

At least 19 recordsLinked to original sources
PubMed1992

Effects of preoperative chemotherapy on gastric adenocarcinomas. A morphologic study of 25 cases.

BACKGROUND: Surgical neoadjuvant therapy for gastric adenocarcinoma affords the opportunity to evaluate critically the histologic effects of preoperative chemotherapy. METHODS: Morphologic alterations in gastric adenocarcinomas were examined in the surgical-resection specimens from 25 patients after 6 weeks of preoperative chemotherapy. The group included 1 patient with a complete response; 4, with subtotal responses; 4, with partial responses; and 16, with no response to preoperative chemotherapy. RESULTS: Histologic manifestations of preoperative chemotherapy included mucosal edema, aggregates of histiocytes in the submucosa and muscularis externa, and stromal fibrosis of the submucosa and muscularis externa. Cytologic manifestations were uncommon and included a single case of signet ring cell carcinoma with diminution of the cytoplasmic vacuoles after preoperative chemotherapy. Clinical follow-up was limited, but 3 of the 25 patients died within 5-8 months after the diagnosis of gastric adenocarcinoma. The gastric-resection specimens from these three patients did not show any histologic manifestations of preoperative chemotherapy. CONCLUSION: As in tumors at other sites, the efficacy of surgical neoadjuvant therapy for gastric adenocarcinoma can be assessed, based on the histologic response of the resected tumor to preoperative chemotherapy.

Adenocarcinoma↗
PubMed1992

Multiple granular cell tumors of the gastrointestinal tract with subsequent development of esophageal squamous carcinoma.

A 52-year-old woman initially presented to our medical center with synchronous, submucosal tumors of the esophagus, stomach, and transverse colon. The gastric and colonic tumors were resected, and both displayed infiltrating sheets of polygonal cells with coarsely granular cytoplasm and small vesicular nuclei. The neoplastic cells of both tumors were immunoreactive for S-100 protein. Ultrastructural studies revealed the lysosomal nature of the cytoplasmic granules. Although the esophageal mass was not resected, it was felt that this represented another focus of granular cell tumor of the gastrointestinal tract. Two years later, she presented with disseminated squamous carcinoma of the esophagus. At autopsy, a submucosal granular cell tumor was found adjacent to the squamous carcinoma of the esophagus. To our knowledge, this is the first reported case of synchronous granular cell tumors that involved multiple segments of the gastrointestinal tract, one of which was later associated with a squamous carcinoma of the esophagus.

Carcinoma, Squamous Cell↗
PubMed1992

Chronic alcohol consumption intensifies caerulein-induced acute pancreatitis in the rat.

Rats were chronically fed either an ethanol-containing diet (36% of total calories derived from alcohol) or a pair-fed, control diet (no alcohol) for 8 wk, and acute pancreatitis (AP) was subsequently induced by a 3-h i.v. infusion of caerulein (CR) at a dose of 5 micrograms/kg/hr. CR-induced AP in control rats (no alcohol) was characterized by a significant elevation in serum lipase content, pancreatic interstitial edema, infrequent occurrences of karyorrhexis, and the appearance of vacuoles in acinar cells. Chronic feeding of the ethanol diet followed by treatment with CR resulted in increases in serum lipase content, interstitial edema, karyorrhexis, and acinar vacuolization that were significantly greater than that seen in rats fed the control diet and treated with CR. It is concluded that chronic ethanol intake in the rat intensifies AP that is subsequently induced by CR.

Acute Disease↗
PubMed1992

Visualization of myocardial cellular architecture using acoustic microscopy.

The resolution of an ultrasound transducer depends on its frequency. The resolution improves when higher frequency transducers are used. A 1000 MHz transducer has a resolution of approximately 1 micron. Acoustic microscopy utilizes very high-frequency ultrasound (600 to 1000 MHz) to visualize structures on a microscopic level. Unstained, deparaffinized, 5 microns sections of myocardial biopsy specimens from 10 patients were placed on a slide and imaged using an Olympus UH3 scanning acoustic microscope. To compare with light microscopy, the section used for acoustic microscopy was subsequently stained with hematoxylin and eosin and a serial section from the paraffin block was stained with PTAH stain. Myocytes, myofibrils, and interstitial tissue were accurately imaged. Pathologic phenomena such as cell fallout, interstitial fibrosis, and lymphocytic infiltration were identified by acoustic microscopy. Intramural vessels, nuclei of endothelial cells, and the media were clearly identified by this technique. There was close correlation between findings by acoustic microscopy and light microscopy. Acoustic microscopy permitted the visualization of cardiac cellular detail with a resolution similar to that of light microscopy. Unlike light microscopy, acoustic microscopy requires no staining of the specimen.

Biopsy↗
PubMed1991

Limb salvage surgery for bone and soft tissue sarcoma. A phase II pathologic study of preoperative intraarterial cisplatin.

Preoperative therapy has been tested as part of limb salvage therapy for localized bone and soft tissue sarcoma of the extremities. The activity of cisplatin (CDDP) by intraarterial (IA) infusion was evaluated in 40 cases of which 36 were evaluable for response. All patients had high-grade sarcomas. All but 3 patients received 3 or 4 courses (24 patients received 4 courses) of CDDP at a dosage of 120 to 150 mg/m2 given over 6 hours every 2 weeks by IA infusion. Patients younger than 18 years of age received the higher dose of CDDP. Treatment was well tolerated with combination antiemetics. One patient experienced severe hearing loss with the first cycle of the higher CDDP dose. Pathologic evaluation of resected osteosarcoma showed a favorable response (90% or greater necrosis) in 8 of 20 evaluable cases and in 3 of 4 patients with malignant fibrous histiocytoma (MFH) of bone (without osteoid). In soft tissue sarcomas, minimal (50% to 89%) necrosis was seen in two of nine cases and none had 90% or greater necrosis. Patients received postoperative chemotherapy based on pathologic response, but the value of this postoperative adjuvant therapy requires further follow-up and is uncertain in this small study. IA CDDP can often cause significant tumor necrosis in patients with bone sarcomas, whereas soft tissue sarcomas are less sensitive to this therapy.

Adolescent↗
PubMed1991

Impaired insulin secretion of aging: role of renal failure and hyperparathyroidism.

Available data indicate that insulin secretion is impaired with aging. Almost all the studies that examined insulin secretion by old animals did not take into consideration the state of renal function or the blood levels of parathyroid hormone (PTH). Old animals may have chronic renal failure (CRF) and secondary hyperparathyroidism, and both of these conditions impair insulin secretion. It is possible, therefore, that the impaired insulin secretion of aging is not due to old age per se, but rather to associated CRF and excess PTH. The present study examined this issue in adult (6 month old) and senescent rats (2 year old) with and without CRF and excess PTH. Senescent rats without CRF had normal renal function and normal blood levels of PTH, and the values were not different from those observed in adult rats. Creatinine clearance in senescent rats with CRF was significantly (P less than 0.01) lower and serum levels of PTH were significantly (P less than 0.01) higher than in senescent animals without CRF and than in the adult rats as well. Only the senescent rats with CRF displayed glucose intolerance during intravenous glucose tolerance test. For any given level of blood glucose, plasma insulin levels were lower in senescent rats with CRF than in the adult rat or senescent animals without CRF.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1991

Immediate versus chronic tissue expansion.

A quantitative comparison of the effects on tissues is performed between chronic tissue expansion, intraoperative expansion, and load cycling in a guinea pig model. Intra-operative expansion, which was developed by Sasaki as a method of immediate tissue expansion for small- to medium-sized defects, and load cycling, which was described by Gibson as a method using intraoperative pull, are compared with chronic tissue expansion on the basis of the following four parameters: amount of skin produced, flap viability, intraoperative tissue pressures, and histological changes. The chronically expanded group, which included booster and nonbooster expansions, produced a 137% increase in surface area, or a 52% increase in flap arc length, whereas intraoperative expansion resulted in a 31% increase in surface area, or a 15% increase in flap arc length. The load-cycled group, however, resulted in an almost negligible amount of skin increase. All three techniques exhibit immediate postexpansion stretchback. Flap viability is not impaired by any of the three techniques, in spite of the elevated pressures observed during expansion. Therefore, intraoperative expansion is effective primarily for limited expansion of small defects, whereas chronic tissue expansion still provides the greatest amount of skin increase when compared with other techniques.

Animals↗
PubMed1990

Carcinoma of the cystic duct.

Two patients with carcinoma of the cystic duct presented with obstructive jaundice due to extrinsic compression of the common hepatic duct by the tumor. Sonography and computed tomography showed dilatation of the intrahepatic bile ducts and gallbladder. In one patient, a calculus seen in the gallbladder neck suggested Mirizzi syndrome. In the other, a small soft tissue mass was indistinguishable from a common duct tumor or an enlarged lymph node. In both cases, direct cholangiography demonstrated extrinsic compression and displacement of the common duct with proximal biliary dilatation and nonvisualization of the gallbladder. Carcinoma of the cystic duct should be considered whenever there is evidence of cystic duct obstruction and/or when cholangiography shows extrinsic mass effect on the common duct.

Bile Duct Neoplasms↗
PubMed1989

Radionuclide angiography in suspected acute cholecystitis: further observations.

Radionuclide angiography (RNA) and cholescintigraphy were performed prospectively in 300 patients with suspected acute cholecystitis (AC). Of 79 patients with positive RNA, 63 had AC (80%). Positive RNA was seen in 23 of 26 cases with gangrenous AC (88%) while 12 of the 26 had a positive "rim" sign (46%). All 12 patients with a positive "rim" sign had positive RNA. The "rim" sign may be caused by increased perfusion. Five of 6 patients with positive RNA and "obstructive" pattern had AC (83%). Patients with negative RNA and positive cholescintigraphy had a positive predictive value of 54% (31/57), while those with positive RNA and positive cholescintigraphy had a positive predictive value of 85% (57/67). RNA showed increased perfusion to nonbiliary pathology such as liver abscesses and pyelonephritis. Positive RNA increases the predictive value of cholescintigraphy and may be useful to shorten cholescintigraphic examinations.

Adult↗
PubMed1989

Absorbable versus permanent mesh in abdominal operations.

Because previous studies evaluating prosthetic mesh have yielded conflicting results, we compared two permanent (polypropylene and polytetrafluoroethylene) and two absorbable (polyglactin and polyglycolic acid) meshes with respect to histologic appearance, development of adhesions, tensile strength and occurrence of hernias in rabbits in which defects of the abdominal wall measuring 2 by 3 centimeters were repaired with one of the meshes. Twenty experiments were performed with each material, and observations were made at two, five, seven and ten weeks. The inflammatory response was minimal with all products. Adhesions were more marked with polypropylene (Marlex) than with polytetrafluoroethylene (Gore-tex); there was no difference between the absorbable meshes. In vitro tensile strength measurements at ten weeks indicated that Marlex was superior to the other materials, and between the absorbable products, polyglactin (Vicryl) was superior to polyglycolic acid (Dexon). No hernias were observed with the nonabsorbable meshes, but all of the rabbits repaired with absorbable meshes had ventral hernias by the tenth week. Thus, absorbable meshes are not indicated when prolonged tensile strength is required, but they may be useful for other purposes, including the temporary repair of fascial defects, since evisceration was not observed.

Abdominal Muscles↗
PubMed1989

Generalized juvenile polyposis with carcinoma.

Generalized juvenile polyposis usually is not associated with an increased risk for gastrointestinal carcinoma. A subgroup of patients, however, have juvenile polyps with adenomatous features. A case report of juvenile polyposis, together with adenocarcinoma of the colon and review of the literature, are presented to emphasize the potential for malignancy in this subgroup of patients and to guide appropriate evaluation.

Adenocarcinoma↗
PubMed1988

Effect of oral iron therapy on the upper gastrointestinal tract. A prospective evaluation.

This study assesses the effect of oral iron therapy on the upper gastrointestinal tract and fecal occult blood testing. Fourteen healthy volunteers completed a checklist of gastrointestinal symptoms, underwent endoscopy and biopsy of the stomach and duodenum, and supplied a fresh stool sample for Hemoccult and HemoQuant testing. They then took ferrous sulfate 325 mg per os tid for two weeks and had the same evaluation repeated. Gastrointestinal symptoms were rated by the patients on a scale of 0-3, endoscopic findings were numerically scored (0-4), and the biopsies were graded blindly. Thirteen other healthy volunteers took ferrous sulfate 325 mg per os tid for one week and had Hemoccult testing of stool at days 0 and 7. All subjects developed dark stools, and significant nausea and diarrhea were noted (0.1 +/- 0.1 to 0.9 +/- 0.3, P less than 0.05 for both symptoms). Only 1/27 had a questionably trace-positive Hemoccult test (two observers disagreed) and no significant difference was seen in HemoQuant testing (1.4 +/- 0.5 to 1.8 +/- 0.7 mg Hb/g). A significant increase was seen in endoscopic abnormalities in the stomach (0.1 +/- 0.1 to 1.5 +/- 0.3, P = 0.003), consisting of erythema, small areas of subepithelial hemorrhage, and, in two subjects, erosions. Biopsies showed no significant change after iron therapy. We conclude that (1) oral ferrous sulfate rarely causes Hemoccult-positive stools, and patients with positive Hemoccult tests on iron therapy require further evaluation; and (2) oral iron may cause mild endoscopic abnormalities in the stomach which are of uncertain clinical significance.

Administration, Oral↗
PubMed1988

Prevalence of Campylobacter pylori and association with antral mucosal histology in subjects with and without upper gastrointestinal symptoms.

To determine the incidence and significance of Campylobacter pylori in patients undergoing routine endoscopic evaluation at this hospital, biopsies of the antrum were obtained from 132 patients and from 15 asymptomatic volunteers. Specimens were cultured and silver stained for the presence of C. pylori and were examined histologically. C. pylori was detected in 67 (51%) patients and two (13%) volunteers (P = 0.006). In patients, C. pylori was found significantly more often when the mucosa was inflamed (67%) than when the mucosa was normal (13%), and both volunteers with C. pylori had chronic gastritis on histological examination. When compared to the volunteers, patients with upper gastrointestinal symptoms had a significantly increased prevalence of antral inflammation, even if the endoscopic examination was normal. C. pylori is infrequently found in young asymptomatic adults but is found in both asymptomatic volunteers and patients in association with all forms of histological antral gastritis which is prevalent in patients with both normal endoscopic findings and peptic ulcer disease.

Adult↗
PubMed1988

Stereotaxic biopsy diagnosis of central nervous system lymphoma.

Twelve cases of central nervous system lymphoma diagnosed by stereotaxic brain biopsy are reviewed to determine the most effective method to establish the diagnosis given the small amount of tissue obtained by this technique. The stereotaxic biopsy material was examined cytologically, histologically, and immunocytochemically. The diagnosis was established by a smear made at the time of biopsy in eight cases. Histologic sections were diagnostic of lymphoma in 11 of 12 cases. Accurate classification according to the Working Formulation was possible in six cases, with diagnosis of diffuse small non-cleaved non-Burkitt's in three, large cell immunoblastic in two, and mixed small and large cell type in one. Five additional cases were diagnosed as high-grade lymphoma but could not be further subclassified because of the small biopsy size or formalin fixation. Immunocytochemical stains for lymphoid markers on paraffin-embedded material confirmed the diagnosis in ten cases, and, in one of these, the demonstration of monoclonality on air-dried cytospins identified an atypical polymorphous lymphocytic population as neoplastic.

Adult↗