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Biomedical subjects

S H Saul

Publications and source records attributed to S H Saul.

At least 19 recordsLinked to original sources
PubMed1998

The lepidopteran transposon vector, piggyBac, mediates germ-line transformation in the Mediterranean fruit fly.

The piggyBac (IFP2) short inverted terminal repeat transposable element from the cabbage looper Trichoplusia ni was tested for gene transfer vector function as part of a bipartite vector-helper system in the Mediterranean fruit fly Ceratitis capitata. A piggyBac vector marked with the medfly white gene was tested with a normally regulated piggyBac transposase helper at two different concentrations in a white eye host strain. Both experiments yielded transformants at an approximate frequency of 3-5%, with a total of six lines isolated having pigmented eyes with various levels of coloration. G1 transformant siblings from each line shared at least one common integration, with several sublines having an additional second integration. For the first transformant line isolated, two integrations were determined to be stable for 15 generations. For five of the lines, a piggyBac-mediated transposition was verified by sequencing the insertion site junctions isolated by inverse PCR that identified a characteristic piggyBac TTAA target site duplication. The efficient and stable transformation of the medfly with a lepidopteran vector represents transposon function over a relatively large evolutionary distance and suggests that the piggyBac system will be functional in a broad range of insects.

Animals↗
PubMed1993

Differences in antigen expression between neoplastic and nonneoplastic gallbladder epithelium. An immunohistochemical study.

Immunoreactivity for a panel of 15 monoclonal antibodies (MAbs), which are known to react with different gastrointestinal tumor antigens, was assessed in formalin-fixed paraffin-embedded sections that were prepared from cholecystectomy specimens obtained from Mexican patients. Each case was classified histologically into one of the following groups: (1) invasive adenocarcinoma (N = 21), (2) high-grade dysplasia (carcinoma in situ) (N = 2), (3) low-grade dysplasia (N = 4), hyperplasia (4) (N = 15), and (5) chronic cholecystitis (N = 10). Significant differences (P < 0.05) were identified among the five histopathologic groups in the proportion of epithelial cells demonstrating immunoreactivity with MAbs to Lewisb; Lewis(a); sialylated Lewis(a); sialylated Lewis(a) and Lewis(a); Y antigen; H antigen; X antigen; X-like antigen; 200-kDa protein of CEA; 180-, 160-, 50-, 40-kDa proteins of CEA; 30- to 37-kDa protein; and an undefined antigen identified by MAb 99-57, with invasive carcinoma more frequently being positive as compared to nonneoplastic (hyperplasia, chronic cholecystitis) epithelium. Significant differences were also observed among the five histopathologic groups (P < or = 0.0005) in the proportion of epithelial cells demonstrating immunoreactivity with MAbs to Y antigen and the 20- to 50-kDa glycoprotein. However, with these two antibodies immunoreactivity was more frequently found in nonneoplastic epithelium rather than in invasive carcinomas. No significant differences in immunoreactivity were detected among the different histologic groups with MAb to blood group B antigen, types 1 and 2. This study demonstrates that cellular antigens are both developed and lost during the process of neoplastic transformation in the gallbladder.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1992

Primary intestinal lymphoma in Crohn's disease: minute tumor with a fatal outcome.

A 54-yr-old man with a 22-yr history of Crohn's disease was found to have a microscopic focus of immunoblastic lymphoma within a segment of small bowel resected to relieve intestinal obstruction. There was no other clinically evident disease. Thirty months later, he developed axillary adenopathy with recurrent lymphoma of the same immunophenotype (IgA lambda) and was given combination chemotherapy, with complete clinical response. Lymphoma recurred 6 months later in the axilla and progressed rapidly over the next 3 months, despite chemotherapy. He developed extensive mediastinal, mesenteric, and retroperitoneal disease with malignant ascites and died 39 months after diagnosis of the incidentally discovered bowel mucosal primary tumor.

Axilla↗
PubMed1990

Neurofilament and chromogranin expression in normal and neoplastic neuroendocrine cells of the human gastrointestinal tract and pancreas.

To differentiate neuroendocrine (NE) neoplasms arising at different levels of the gut and pancreas, the authors studied the expression of neurofilament (NF) proteins and chromogranin (CR) in normal and neoplastic NE cells of the human gastrointestinal tract (GIT) (14 ileal/jejunal carcinoids, six appendiceal carcinoids, 11 rectal carcinoids) and pancreas (23 islet cell tumors). Among pancreatic islet cell tumors, those with middle molecular weight (NF-M)-positive cells were more abundant than those with high molecular weight (NF-H)-positive cells; nearly all of these tumors expressed CR. Although NF-M was abundantly expressed in greater than 50% of tumor cells in a subset of these tumors, only one of these tumors exhibited diffuse immunoreactivity with NF-H. Among rectal carcinoid tumors, NF-M and NF-H-positive cells were present in approximately the same number of tumors, yet only diffuse immunoreactivity to NF-H could be detected. Chromogranin immunoreactivity in greater than 50% of tumor cells was present in 74% of islet cell tumors, 93% of ileojejunal carcinoids, and 83% of appendiceal carcinoids, but only in a minority of rectal carcinoids (36%). Although ileojejunal carcinoid tumors rarely expressed NF-M and did not express NF-H, diffuse immunoreactivity with CR was present in nearly all of these tumors. None of the appendiceal carcinoid tumors expressed NF-M or NF-H, yet all of these tumors demonstrated immunoreactivity with CR. Neurofilament immunoreactivity was not detected in normal GIT and pancreatic NE cells, whereas CR immunoreactivity was always present. These results suggest that for NE neoplasms of the GIT and pancreas the differential expression of NF subtypes appears to be related to tumor site; and CR is a marker of most GIT and pancreatic NE neoplasms although NF may discriminate subtypes of GIT and pancreatic NE tumors. Neurofilament subtyping may be useful in the evaluation of the origin of NE tumors presenting as metastatic lesions.

Adenoma, Islet Cell↗
PubMed1990

Actin genes in the Mediterranean fruit fly, Ceratitis capitata.

We have undertaken the study of actin gene organization and expression in the genome of the Mediterranean fruit fly (medfly), Ceratitis capitata. Actin genes have been extensively characterized previously in a wide range of eukaryotic organisms, and they have valuable properties for comparative studies. These genes are typically highly conserved in coding regions, represented in multiple copies per genome and regulated in expression during development. We have isolated a gene in the medfly using the cloned Drosophila melanogaster 5C actin gene as a probe. This medfly gene detects abundant messages present during late larval and late pupal development as well as in thoracic and leg tissue preparations from newly emerged adults. This pattern of expression is consistent with what has been seen for actin genes in other organisms. Using either the D. melanogaster 5C actin gene or the medfly gene as a probe identifies five common cross reacting EcoRI fragments in genomic DNA, but only under less than fully stringent hybridization conditions.

Actins↗
PubMed1990

Non-Hodgkin lymphoma of the small intestine.

The authors present a simplified radiographic classification of non-Hodgkin lymphoma involving the small intestine. The classification system is based on radiographic findings in 22 pathologically proved cases of lymphoma involving the small bowel and consists of three major forms: primary, lymphoma complicating celiac disease, and mesenteric nodal. In this series, small bowel lymphoma was evenly distributed in the jejunum and ileum. The most common radiographic patterns were circumferential lesion (seven cases), cavitary lesion (four cases), and mesenteric nodal disease invading the small bowel (seven cases). Obstructive symptoms were usually encountered with the mesenteric nodal form. Lymphoma complicating celiac disease was typified by multiple, thickened, nodular folds involving a segment of proximal small intestine.

Adult↗
PubMed1990

Atypical hyperplastic polyps at double-contrast barium enema examination.

At radiography, hyperplastic polyps classically appear as smooth, sessile elevations less than 5 mm in diameter. However, a retrospective review of double-contrast barium enema studies in 22 patients with 31 pathologically proved hyperplastic polyps revealed an average polyp size of 7.3 mm, with a range of 3-21 mm. Fifteen polyps (48%) were 2-5 mm, 12 (39%) were 6-10 mm, and four (13%) were greater than 10 mm in diameter. Twenty-nine polyps (94%) were sessile, and two polyps (6%) were pedunculated. Twenty-three polyps (74%) had a smooth contour, and eight polyps (26%) were lobulated. Twenty-six of the hyperplastic polyps (84%) were located in the rectosigmoid colon. If the radiologic criteria for an atypical hyperplastic polyp at double-contrast barium enema examination include size greater than 5 mm, lobulation, and/or pedunculation, 16 of the 31 hyperplastic polyps (52%) could be classified as atypical. Thus, radiologists should be aware that many hyperplastic polyps seen at double-contrast barium enema examination do not fit the classic description of a smooth, sessile elevation less than 5 mm in size but instead appear as larger, more lobulated lesions that are indistinguishable from adenomatous polyps.

Adult↗
PubMed1990

Colorectal tumors: an in vitro study of high-resolution MR imaging.

To study the potential utility of magnetic resonance (MR) imaging in staging colorectal tumors, 15 resected colonic segments containing 17 elevated lesions were examined on a 1.5- or 1.9-T superconductive MR system. The whole intestinal wall was apparent as three or five layers on images obtained with a short repetition time (TR) and short echo time (TE) and as six or eight distinct layers, including the intestinal wall proper as well as an adherent mucus layer and an outer layer of pericolonic fat, on the long TR/TE images. In cases of colonic carcinoma, MR images correlated well with the pathologic findings, including the macroscopic growth pattern, depth of mural invasion, and the presence of foci of calcific tumor necrosis and pools of extracellular mucin (colloid). These features suggest that MR imaging may be valuable in the clinical evaluation of colorectal tumors.

Adenocarcinoma↗
PubMed1989

Gastric small lymphocytic proliferation with immunoglobulin gene rearrangement in pseudolymphoma versus lymphoma.

The nature of gastric infiltrates consisting primarily of benign-appearing small lymphocytes is at present a controversial issue. Earlier reports of gastric lymphoma developing in gastric pseudolymphoma and more recent immunohistochemical studies demonstrating monoclonal B-cell populations in pseudolymphoma suggest that at least some cases represent low-grade lymphomas or clonal precursor lesions that may develop into lymphoma. Observations of a small lymphocytic infiltrate arising in the region of a gastric ulcer that lacked definitive morphologic evidence of malignancy (lymphoma) but was clearly a monoclonal B-cell proliferation by immunohistochemical and gene rearrangement studies support the notion that some gastric lymphoproliferative lesions that histologically have been called pseudolymphomas may include one or more clonal lymphoid expansions. A histopathologic/molecular model suggesting a potential pathway for the development of morphologically recognizable lymphoma from benign-appearing small lymphocytic infiltrates is presented, and the concept that for a variety of lymphoid proliferations clonality and malignancy may not be synonymous is discussed.

Aged↗
PubMed1989

Benign pneumoperitoneum in a patient with celiac sprue.

A patient with celiac sprue was found to have an asymptomatic pneumoperitoneum. Prompt recognition that the pneumoperitoneum was due to pneumatosis cystoides intestinalis prevented unnecessary surgical intervention. Severe mucosal disease of the small intestine can be associated with an asymptomatic pneumoperitoneum.

Aged↗
PubMed1989

Adult celiac disease and its complications.

Classic radiographic findings described in adult celiac disease--lumen dilatation, flocculation of barium, hypersecretion, thickening of folds--are nonspecific or are secretion related artifacts. The small bowel enema technique and CT make it possible to demonstrate specific diagnostic features of the disease and its complications. This substantially modified approach to the diagnosis of adult celiac disease is presented together with correlative pathology. Examples of the complications of celiac disease--ulcerative jejunoileitis, lymphoma, hyposplenism, carcinoma, and the cavitary lymph node syndrome--are illustrated.

Adult↗
PubMed1989

In situ hybridization analysis of human papillomavirus in anal squamous cell carcinoma.

To investigate the association between human papillomavirus (HPV) infection and anal carcinoma, we applied a sensitive in situ hybridization technique to detect HPV messenger RNA (HPV m-RNA) in formalin-fixed, paraffin-embedded sections from 18 patients. Using tritium-labeled probes, HPV m-RNA was detected in 12/18 (67%) patients. HPV 6 was detected in four patients, coexisting with HPV 18 in two cases, and HPV 16 was found in eight patients. In six patients, hybridization failed to demonstrate the presence of HPV. With respect to histology, HPV 6 was detected in 1/4 cases of well differentiated invasive squamous cell carcinoma. Ten of thirteen moderately or poorly differentiated invasive squamous cell carcinomas demonstrated HPV m-RNA (HPV 16, eight cases; HPV 6, one case; HPV 6 and 18, one case). HPV 31 was not detected in any specimens. These results suggest that HPV infection may play an important role in the pathogenesis of anal carcinoma.

Adult↗
PubMed1988

Barrett's esophagus in scleroderma: increased prevalence and radiographic findings.

Ten of 27 patients (37%) with scleroderma who underwent endoscopy at our hospital between 1980 and 1984 for symptoms of reflux esophagitis had biopsy-proven Barrett's esophagus. Two of those 10 patients had esophageal adenocarcinomas. In a blinded review of esophagrams (all but 2 using double-contrast technique) from 16 of the 27 patients, only 1 patient was thought to be at high risk for Barrett's esophagus due to a high esophageal stricture with an adjacent reticular pattern of the mucosa. The latter patient had biopsy-proven Barrett's mucosa. Eight patients were thought to be at moderate risk for Barrett's esophagus due to reflux esophagitis and/or distal strictures in 6 and polypoid intraluminal masses in 2. Three of the 6 patients with esophagitis and/or strictures had Barrett's esophagus, and both patients with masses had adenocarcinomas arising in Barrett's mucosa. Finally, 7 patients who had no esophagitis or strictures were thought to be at low risk for Barrett's esophagus. None of those 7 had histologic evidence of Barrett's mucosa. Thus, the major value of double-contrast esophagography is its ability to classify patients into high-, moderate-, and low-risk for Barrett's esophagus to determine the relative need for endoscopy and biopsy in these patients.

Adenocarcinoma↗