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Biomedical subjects

A M Elsayed

Publications and source records attributed to A M Elsayed.

13 recordsLinked to original sources
PubMed1997

Carcinoids of the jejunum and ileum: an immunohistochemical and clinicopathologic study of 167 cases.

BACKGROUND: Carcinoid tumors of the gastrointestinal tract differ in their clinical and histopathologic features, depending on the site of origin. There are few clinicopathologic studies that specifically describe jejunoileal carcinoid tumors. METHODS: One hundred sixty-seven ileal and jejunal carcinoids were retrospectively studied with emphasis on clinical, pathologic, immunohistochemical, and prognostic features. RESULTS: The mean age of patients at the time of presentation was 62 +/- 12 years (range, 13-93 years). Eight patients had carcinoid syndrome (5%) and 1 had Zollinger-Ellison syndrome. Twenty-six percent of tumors were multiple, and 77% were transmurally invasive; 31% had regional lymph node metastases only, and 32% had liver or mesenteric metastases. Ninety-three percent of tumors had an insular growth pattern. Serotonin was expressed in 86% of tumors (86 of 102), chromogranin in 92%, and neuron specific enolase in 95%. Twenty percent of tumors (10 of 51) expressed prostatic acid phosphatase; 96% were argyrophil, and 98% argentaffin. Of 80 cases with follow-up data (mean follow-up, 52 +/- 5 months), 21% were dead of disease, 16% were dead of other causes, 19% were alive with disease, and 44% had no evidence of disease at last follow-up. The 5-year Kaplan-Meier survival estimate for all cases was 58%. By univariate analysis, survival was negatively correlated with distant metastases at the time of surgery (P = 0.002), mitotic rate (P = 0.01), tumor multiplicity (P = 0.01), the presence of carcinoid syndrome (P = 0.02), depth of invasion (P = 0.03), and female gender (P = 0.05); by multivariate analysis, survival was negatively associated with distant metastasis (P = 0.002), carcinoid syndrome (P = 0.01), and female gender (P = 0.03). CONCLUSIONS: Jejunoileal carcinoid tumors have a relatively high rate of transmural invasion and aggressive clinical behavior. They are usually insular and largely argentaffin, with a high rate of chromogranin and serotonin positivity. These features differentiate jejunoileal carcinoids from other gastrointestinal carcinoids.

Adolescent↗
PubMed1996

Inverted Meckel diverticulum: clinical, radiologic, and pathologic findings.

PURPOSE: To determine the clinical, radiologic, and pathologic findings of inverted Meckel diverticulum by retrospectively reviewing a large series of cases. MATERIALS AND METHODS: Among 84 cases of Meckel diverticulum, 18 (21%) were found at surgery to be inverted into the lumen of the bowel. Thirteen of these 18 (72%) cases were associated with small bowel intussusception and five (28%) were not. RESULTS: All 18 patients (median age at time of diagnosis, 32 years) were symptomatic, but the symptoms were subacute or chronic in 14 (78%). At barium examination in 15 cases, inverted diverticulum was depicted in 10 (67%) as a solitary, elongated, smoothly marginated, often club-shaped intraluminal mass in the distal ileum. At computed tomography (CT) in three cases, a central area of fat attenuation was surrounded by a thick collar of soft-tissue attenuation. At ultrasound (US) in two cases, a target-like mass contained a central area of increased echogenicity. At pathologic examination in all cases, the inverted sac contained mesenteric fat. CONCLUSION: Inverted Meckel diverticulum occurs more commonly than previously recognized and is associated with characteristic findings at barium examination, CT, and US.

Adolescent↗
PubMed1996

Meckel's enteroliths: clinical, radiologic, and pathologic findings.

OBJECTIVE: The objective of this study was to determine the clinical, radiographic, and pathologic findings of Meckel's enteroliths, a rare complication of Meckel's diverticulum. MATERIALS AND METHODS: Of 84 cases of Meckel's diverticulum, eight (10%) were found at surgery to contain enteroliths. Abdominal radiographs and barium studies of these eight patients were reviewed retrospectively. Medical and pathologic records were also reviewed. RESULTS: At the time of diagnosis, the median age of the eight patients with Meckel's enteroliths was 45 years old. Six patients were male, and two were female. All eight patients were symptomatic, but symptoms were chronic in six patients (75%). Meckel's enteroliths were seen on abdominal radiographs in seven patients (88%). The stones had an average diameter of 3 cm (range, 1-5 cm). Five patients had multiple opaque stones, and two patient had solitary stones (total number of stones, 18). Sixteen of the enteroliths were revealed as peripheral calcified stones with radiolucent centers; two were revealed as laminated stones. One patient had a Meckel's stone ileus due to extrusion of an enterolith into the lumen that subsequently caused small-bowel obstruction. Histologically, all Meckel's diverticula with enteroliths contained intestinal mucosa lining without ectopic gastric mucosa. CONCLUSION: Meckel's enteroliths are a rare complication of Meckel's diverticulum. Nevertheless, this entity should be included in the differential diagnosis of abdominal calcification when a peripheral calcified stone or, less commonly, a laminated stone is detected in the lower abdomen on radiographs of adults with chronic abdominal pain or gastrointestinal blood loss.

Adolescent↗
PubMed1996

Malignant melanomas in the small intestine: a study of 103 patients.

OBJECTIVES: Malignant melanoma shows an unusual predilection to metastasize to the small intestine. A proportion of small bowel melanomas occur without history of an antecedent primary. We evaluated a group of patients with malignant melanoma in the small intestine to further our understanding of this disease. METHODS: We reviewed 103 cases of malignant melanoma in the small intestine (77 surgical resections and 26 autopsies) accessioned at the Armed Forces Institute of Pathology between 1945 and 1991 for demographic, chronological, and pathological features. RESULTS: Mean age at time of primary was 45.6 yr for surgical and 34.1 yr for autopsy cases (p = 0.01). Mean age at time of small intestinal involvement was 52.2 yr for surgical and 42.7 yr for autopsies (p = 0.03). Primary lesions preceded intestinal disease by an average of 5.6 yr for surgical and 2.1 yr for autopsies. The age distribution of surgical patients with and without known primary melanomas at the time of small intestinal melanoma was not significantly different. The same was true for autopsy patients. Using regression analysis, the linear relationship of age at primary melanoma (AAP) on age at small intestinal melanoma (AASI) was given by AAP = 2.30 + 0.85 (AASI), and that of AASI on AAP was given by AASI = 3.94 + 1.02 (AAP) (r = 0.93 and p < 0.0001 for both regressions). CONCLUSIONS: Our data and results support the concept that small bowel involvement by melanoma, even without a known primary, is most probably metastatic. The age at which an unknown primary occurred in cases of intestinal melanoma, or the age at which intestinal metastasis may appear in cases with known primary melanoma, can be estimated. There appear to be two subsets of primary melanoma: one that occurs among younger patients and is more aggressive with rapid metastasis and early death and one that occurs among older patients, is more indolent, and metastasizes less rapidly.

Adult↗
PubMed1995

Teleradiology/telepathology requirements and implementation.

Teleradiology and telepathology form an integral part of the telemedicine concept. Teleradiology is becoming a mature technology because of advances in imaging technology, database design and communications infrastructure and capabilities. Telepathology has also made significant progress but more development is needed in the definition of required images, database design and standards. While the requirements of most clinical applications of teleradiology are well established, telemammography still presents some impediments. Technical difficulties in telemammography are presented in terms of the lack of a clinically accepted digital imaging system and large data volume required per image. Another important aspect in tele-imaging is the database question. Workstations constitute a window into database. Comprehensive database development is the most difficult and expensive technology for tele-imaging and operational features of such systems are discussed. Finally, we explore current examples of the use of telepathology and teleradiology in the global telemedicine context.

Computer Communication Networks↗
PubMed1995

Visual performance with the Aviator Night Vision Imaging System (ANVIS) at a simulated altitude of 4300 meters.

This study determined if visual performance with Aviator Night Vision Imaging System (ANVIS) was degraded by the degree of hypoxia experienced at the maximum flight altitude currently authorized (U.S. Army regulations) without supplemental oxygen. Visual acuity and contrast sensitivity with ANVIS were tested under simulated starlight and full moonlight illumination in a hypobaric chamber: at ground level (93 m), 5 min and 30 min after ascent to 4300 m, and 10 min after return to ground level. Visual acuity was significantly (p < 0.05) degraded by a small amount (0.05 log minimal angle resolvable) after 30 min at 4300 m. Contrast sensitivity was not significantly degraded at any time. No significant difference between males (n = 11) and females (n = 6) on any measure of visual performance was detected. Females did have a significantly lower percent oxygen saturation of hemoglobin compared with males at altitude (72% versus 80% after 30 min). The results suggests that visual acuity ANVIS is degraded slightly after 30 min of exposure to 4300 m, although less than what would be expected with unaided night vision under these conditions.

Adult↗
PubMed1994

Gastric carcinoids. An immunohistochemical and clinicopathologic study of 104 patients.

BACKGROUND: Gastric carcinoids are uncommon, and are unlike carcinoids at other gastrointestinal sites, clinically and pathologically. METHODS: The authors studied specimens from 104 patients with gastric carcinoid, with study emphasis being placed on pathologic features, immunohistochemistry, clinical associations, and prognostic factors. RESULTS: The average age of the 47 male patients and 57 female patients was 61 years. Twenty-seven patients had chronic atrophic gastritis, 12 had pernicious anemia, and 6 had hypergastrinemia; no patient had carcinoid syndrome. Most of the tumors were confined to the mucosa and submucosa. Lymph node metastases were present in only one patient. The tumors were argyrophilic in 84% and argentaffin in 14%. Chromogranin tested positive in all patients; serotonin was detected in one-third; other hormones were much less common. Gastrin-positive tumors were antral. Of the 62 patients with follow-up, 44 were alive without disease, 4 were alive with disease, and 14 were dead (4 died of carcinoid-related disease). None of the deceased had pernicious anemia or hypergastrinemia. The tumors in patients with a fatal outcome were 2 cm or larger. CONCLUSION: Gastric carcinoids generally are indolent tumors, particularly when associated with pernicious anemia or hypergastrinemia or when smaller than 2 cm. Chromogranin is the most sensitive marker.

Adult↗
PubMed1993

Gastrointestinal hemorrhage associated with gastric polyps in Menkes disease.

We describe two infants with Menkes disease who had serious gastrointestinal bleeding from solitary gastric polyps. Hemorrhage in one patient was acute and proved fatal. Histopathologic examinations showed submucosal vascular ectasia with mucosal hyperplasia, edema, and ulceration. Gastric polyps may represent an underappreciated clinical abnormality in Menkes disease.

Gastrointestinal Hemorrhage↗
PubMed1993

Association of mucinous tumors of the ovary and appendix. A clinicopathologic study of 25 cases.

Twenty-five patients with mucinous tumors of the ovary and appendix were studied. The average age of the patients was 52 years, and the ovarian and appendiceal tumors were discovered synchronously in all but two cases. The majority had either a pelvic mass or abdominal or pelvic pain. A high frequency of bilateral ovarian tumors (11/25), and right-sided predominance for the unilateral ovarian tumors (nine right, five left) were found. Four patients had ovarian mucinous carcinomas, 10 had mucinous tumors of low malignant potential, 10 had mucinous cystadenomas, and one had a mucinous cyst. Pseudomyxoma ovarii was present in 22 cases. Twenty-two of 24 appendices were grossly abnormal. There were six appendiceal mucinous adenocarcinomas, 10 mucinous tumors of uncertain malignant potential, seven mucinous cystadenomas, one hyperplastic polyp, and one mucocele. Twelve patients had ovarian and appendiceal tumors of similar malignant potential, nine had appendiceal tumors with more aggressive morphologic features than the corresponding ovarian tumor, and four had ovarian tumors with more aggressive morphologic features than the appendiceal tumor. Eighteen patients had peritoneal involvement by mucinous epithelium admixed with mucus (nine localized, nine diffuse). Immunoperoxidase reactions for four epithelial antigens in 15 cases showed complete concordance between ovarian and appendiceal lesions in only five cases and were not helpful in determining the site of origin of the peritoneal tumor. Our findings suggest an independent origin of the ovarian and appendiceal tumors in most cases and do not favor an origin in a single site. Furthermore, it is proposed that the peritoneal lesions may arise de novo as part of a multifocal neoplastic process.

Adenocarcinoma↗
PubMed1993

Ampullary tumors: radiologic-pathologic correlation.

Ampullary adenoma and adenocarcinoma are the benign and malignant neoplasms that arise from the glandular epithelium of the ampulla of Vater. When the tumors are small and confined to the ampulla, endoscopic and radiographic appearances may be normal. Larger intraampullary tumors appear as a prominent papilla or a mural mass. Computed tomography and ultrasound (US) show dilatation of the common bile duct or pancreatic duct in such cases, but the mass itself may not be seen. Larger lesions with intraduodenal extension are more easily identified with cross-sectional imaging. Endoscopic US is the best technique for tumor staging. The differential diagnosis includes other periampullary tumors such as pancreatic carcinoma, cholangiocarcinoma, and villous adenomas and adenocarcinomas of the duodenum. Mural masses of the periampullary duodenum including choledochocele and carcinoid should also be considered. Accurate diagnosis of ampullary tumors is important because the patients are usually candidates for a Whipple operation. Recent reports quote overall 5-year survival rates of 28%-70%. The prognosis is even better for patients with a limited stage of disease.

Adenocarcinoma↗
PubMed1988

Suppression of large intestinal cancer in F344 rats by inositol hexaphosphate.

Epidemiological data demonstrate correlations between dietary factors and the incidence of large intestinal cancer (LIC). Certain high-fiber diets are associated with a lower risk of LIC; these high-fiber diets are also rich in inositol hexaphosphate (IP6 or phytic acid). In a pilot study, we have used F344 rats to investigate the effect of sodium inositol hexaphosphate (Na-IP6) prior to (experiment I) and following injections of the carcinogen azoxymethane (AOM) (experiment II). In experiment I, rats started on 1% Na-IP6 in drinking water 1 week prior to the carcinogen treatment showed a 34.7% decrease (P less than 0.01) in LIC compared to control carcinogen treatment group. A similar reduction in the incidence of LIC was also observed in experiment II, wherein Na-IP6 supplementation was started 2 weeks following the last dose of the carcinogen. Comparison of the incidence of mitosis in the colonic crypts of the animals in different groups show that animals on AOM + IP6 demonstrate a significantly lower (P less than 0.001) mitotic rate than those receiving AOM only. Pilot studies of free radical generation demonstrate a reduction in .OH radical formation by Na-IP6. Further studies to expand this pilot data and to understand the mechanism of IP6 mediated LIC suppression are needed for it may have significance in our strategies for LIC control.

Animals↗
PubMed1986

Ultrastructural features of normal mouse colon epithelium. Unique characteristics of a species.

Ultrastructural studies of the colon epithelium of normal C57Bl/Ha and ICR/Ha mice revealed some unique characteristics not seen in human or rat colon. The most striking feature was the presence of a unique type of intracytoplasmic organelle with crystalline internal structure. These organelles measured 1-2 micron in diameter, usually rounded or oval showing marked variation in size and shape. They were surrounded by a single layer of trilaminar plasma membrane and their core structure was mildly electron dense with markedly dense crystalline substructure. Grimelius silver stain done at ultrastructural level revealed these to have staining properties identical to neuroendocrine granules. Approximately 1-5% of the epithelial cells of mouse colon were usually filled with these organelles. But occasionally they were also present in the endocrine cells of colon. The other striking feature of the mouse colon epithelium is the presence of an inordinate number of bacteria. These rod shaped bacteria were present deep inside crypts in large numbers. They were also present within the goblet type of mucous cells and the so-called columnar cells of the surface epithelium. A third unique feature of mouse colon was the presence of mitotic figures in cells with conspicuous mucous vacuoles. This contrasts with human and rat colon where mitosis occurs in cells with little or no mucus. Since the ultrastructural morphology of the normal mouse colon is distinctly different from the human and rat, caution must be exercised in extrapolating colon carcinogenesis data from mouse to human.

Animals↗