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P Sherman

Publications and source records attributed to P Sherman.

At least 73 records · Page 4Linked to original sources
PubMed1992

Omeprazole therapy for Helicobacter pylori infection.

To determine whether omeprazole eradicates Helicobacter pylori infection of the gastric antrum, six adolescents and one adult with H. pylori colonization of the antrum were entered into a clinical, open trial of medical therapy. Histologic evidence of antral gastritis and three complementary methods to document H. pylori colonization of the stomach (silver stain, urease testing, and culture of antrum) were obtained before and after an 8-week course of omeprazole. In vitro susceptibility to omeprazole and restriction endonuclease analysis were performed on H. pylori isolates obtained from patients before and after omeprazole therapy. Each of the seven patients treated with omeprazole had continued active inflammation in the antrum and one or more features indicative of persisting H. pylori colonization. Minimum inhibitory concentrations and DNA fingerprints of H. pylori isolated after therapy were identical to those of the pre-treatment bacterial isolates in each of the four subjects examined. We conclude that omeprazole therapy alone did not eradicate H. pylori infection of the human antrum. Continued bacterial colonization was not related to either acquired bacterial resistance to the drug or reinfection of the stomach with a different H. pylori strain.

Adolescent↗
PubMed1991

Perianal complications of pediatric Crohn's disease.

The management of perianal disease (PD) in children with Crohn's disease was reviewed. Of 325 patients (184 boys), 200 (62%) developed PD. The mean age at diagnosis of Crohn's disease was 11.2 years (range, 5 to 17 years). Skin tags were present in 114 (35%) patients, fissures in 165 (51%), fistulas in 41 (15%), and perirectal abscesses in 47 (13%). One hundred fifty-three patients had PD as one of the first symptoms; 71 of these had complete remission of PD and the remaining 82 had chronic symptoms. Forty-two patients were initially free of PD, only to develop it later. PD occurred in 50% of patients with gastroduodenal Crohn's disease, 57% with jejunal, 68% with ileal, 64% with ileocecal, 60% with ileocolic, and 51% with colonic. Local minor operation was necessary in 38 (12%) patients, fistulotomy in 12, and abscess drainage in 26. Four patients required either intestinal resection and/or enterostomy for progressive PD. Fifty-three patients received metronidazole, with amelioration in 38. It is concluded that PD is a common complication of Crohn's disease in children and adolescents. Its presentation may antedate that of the primary disease. Most PD follows a benign course. There is a limited role for operation, but a need for meticulous perineal care and a potential benefit with metronidazole therapy. We advocate conservatism in the management of perianal complications of Crohn's disease in pediatric patients.

Abscess↗
PubMed1991

Adherence of Helicobacter pylori to human gastric epithelial cells in vitro.

Gram-negative spiral organisms, currently referred to as Helicobacter pylori, are associated with primary gastritis and duodenal ulceration. The organisms colonise gastric mucus and adhere to epithelial cells of inflamed antra. To further examine the binding of H. pylori to human gastric epithelial cells, we developed and characterised an in-vitro bacterial adherence assay. Scanning electronmicroscopy suggested that spiral-shaped bacteria were adherent to the surface of KATO-III cells which were derived from a human gastric adenocarcinoma. Transmission electronmicroscopy confirmed the attachment of H. pylori to these epithelial cells in tissue culture. Some bacteria were adherent to intact microvilli, others were closely adherent to the plasma membrane in regions where microvilli were effaced. In studies with radiolabelled H. pylori, adherence to epithelial cells in tissue culture contrasted with minimal binding of bacteria to polystyrene wells alone. Incubation of bacteria with gastric cells at 4 degrees C significantly reduced adherence of H. pylori. We conclude that adherence of H. pylori to gastric epithelial cells in tissue culture involved "attachment and effacement mechanisms". This assay could serve as a suitable in-vitro model for the study of the bacterial adhesins and host receptors which mediate attachment of H. pylori to gastric epithelial cell surfaces.

Amino Acids↗
PubMed1991

Outer membranes are competitive inhibitors of Escherichia coli O157:H7 adherence to epithelial cells.

Escherichia coli of serotype O157:H7 are Vero cytotoxin-producing enteric pathogens that have been associated recently with sporadic cases and outbreaks of hemorrhagic colitis and with the hemolytic-uremic syndrome. Adherence of many enteropathogenic bacteria to mucosal surfaces is a critical step in the pathogenesis of diarrheal disease. We showed previously that adherence of E. coli O157:H7 strain CL-56 to epithelial cells in vitro is inhibited by outer membranes. In this study we examined whether outer membranes from a series of E. coli O157:H7 strains mediated competitive inhibition of bacterial binding to epithelial cells grown in tissue culture. We also determined which constituents of the outer membrane mediated inhibition of CL-56 adherence. Binding of six O157:H7 strains to HEp-2 cells was determined by quantitating the number of adherent bacteria in the presence and absence of outer membranes which were extracted from each strain with N-lauroyl sarcosinate (1.7%, wt/vol). After separation of outer membranes by gel electrophoresis, four bands (94, 40, 36, and 30 kDa) were collected by electroelution. Immune sera were raised in rabbits to each of the four eluted bands. Outer membrane extracts from each of the six O157:H7 strains inhibited binding of homologous organisms to the HEp-2 cells. At dilutions which did not cause bacterial agglutination, antiserum raised against the 94-kDa outer membrane protein showed maximal inhibition of bacterial adherence (17.0 +/- 7.3% adherence of control levels). Growth of bacteria in iron-depleted broth did not affect their binding to HEp-2 cells, suggesting that iron-regulated outer membranes were not involved. Fluid accumulation in ileal ligated loops of rabbits in response to E. coli O157:H7 challenge was diminished following both parenteral immunization with outer membranes extracted from the homologous strain and coincubation of organisms with immune serum which contained antibodies to outer membrane extracts. These data indicate that outer membranes are competitive inhibitors of E. coli O157:H7 adherence. Specific constituents of the outer membrane may function as bacterial attachment factors (i.e., adhesins) for E. coli O157:H7 adherence to epithelial cell surfaces.

Actins↗
PubMed1990

Typing of Campylobacter pylori by bacterial DNA restriction endonuclease analysis and determination of plasmid profile.

Campylobacter pylori isolates from 37 symptomatic patients and 3 asymptomatic volunteers were examined by chromosomal DNA restriction endonuclease analysis and determination of plasmid profile. Restriction digests with HindIII, HaeIII, PvuII, and BglII produced clear and reproducible results that permitted discrimination between different strains. Only 35% of C. pylori isolates were found to have plasmid DNA. Isolates from different patients, including those from two pairs of siblings, had unique restriction patterns and plasmid profiles. Consecutive isolates obtained 1 year apart from each of two asymptomatic volunteers had identical restriction patterns and plasmid profiles, suggesting persistence of the same strain. A pair of isolates obtained one year apart from the third volunteer differed in plasmid DNA content but had similar chromosomal DNA restriction patterns. Plasmid profile determination and bacterial DNA restriction endonuclease analysis provide a reliable means of discriminating between different strains of C. pylori and may be useful for typing these organisms in epidemiologic studies.

Campylobacter↗
PubMed1989

Effect of oligomannoside-type glycopeptides in diarrheal disease of rabbits induced by Escherichia coli strain RDEC-1.

We examined the effects of a soluble receptor-like complex carbohydrate (an oligomannoside-type glycopeptide) on adherence of a type 1 fimbriated rabbit enteropathogen, Escherichia coli strain RDEC-1. Oligomannoside-type glycopeptide, but not a non-glycosylated peptide mixture used as control, inhibited adherence of type 1 fimbriated RDEC-1 to both rabbit ileal brush borders and guinea pig erythrocytes in vitro. In contrast, during RDEC-1 infection of rabbits the receptor-like oligomannoside did not affect the presence and severity of diarrhea, fecal shedding of organisms, luminal colonization by RDEC-1, or enteroadherence of organisms.

Animals↗
PubMed1989

Gastric glycerolipid as a receptor for Campylobacter pylori.

A species was detected in the lipid extract of human red blood cells and human and pig stomach tissue which was specifically recognised by isolates of Campylobacter pylori. The levels of this lipid were higher in human stomach antrum than in fundus and in adult compared with infant tissue samples. Chemical treatment of the purified substance suggests that it is a novel glycerolipid.

Animals↗
PubMed1989

The putative 'link' glycopeptide associated with mucus glycoproteins. Composition and properties of preparations from the gastrointestinal tracts of several mammals.

The existence of a discrete 'link' peptide in epithelial mucins has been debated for many years. There is evidence that at least some mucins contain a specific 'link' peptide (or glycopeptide) that enhances mucin polymerization by forming disulphide bridges to large mucin glycoprotein subunits. A major difficulty has been to know whether the reported differences in putative 'link' components represent artifacts generated by inter-laboratory differences in technical procedures used in mucin purification. The present paper outlines the results of a collaborative study involving five laboratories and 53 samples of purified gastrointestinal mucins (including salivary, gastric, small-intestinal and colonic mucins) prepared by five techniques from four different animal species. An early step in mucin purification in all cases was the addition of proteinase inhibitors. Representative mucins were analysed for their composition, electrophoretic mobility in SDS/polyacrylamide-gel electrophoresis before and after disulphide-bond reduction, and for their reactivity with monospecific antibodies developed against the 118 kDa putative 'link' glycopeptide isolated from either rat or human small-intestinal mucins. Our results indicate that, despite differences in laboratory techniques, preparative procedures, organs and species, each of the purified mucins contained a 'link' component that was released by disulphide-bond reduction and produced a band on SDS/polyacrylamide-gel electrophoresis at a position of approx. 118 kDa. After electroelution and analyses, the 118 kDa bands from the different mucins were found to have similar amino acid profiles and to contain carbohydrate. It would appear therefore that a 'link' glycopeptide of molecular mass approx. 118 kDa is common to all of the gastrointestinal mucins studied.

Animals↗
PubMed1989

Adherence of bacteria to the intestine in sporadic cases of enteropathogenic Escherichia coli-associated diarrhea in infants and young children: a prospective study.

Intimate adherence of bacteria to duodenal enterocytes was demonstrated in a 12-mo-old child with sporadic diarrhea that was associated with an enteropathogenic Escherichia coli (EPEC) of the serogroup O111:K58. Therefore, a prospective study was initiated to determine if identification of EPEC in stools from sporadic cases of diarrhea of longer than 10 days in duration in children under 24 mo of age correlated with E. coli colonization of the proximal small intestine and with binding of bacteria to intestinal epithelial cells. Colonization was determined by culture of duodenal aspirates and enteroadherence by light- and electron-microscopic evaluation of both duodenal and rectal mucosa. Each EPEC isolate was examined for several previously proposed laboratory markers of virulence including alpha-hemolysin production, agglutination of erythrocytes, cell surface hydrophobicity properties, adherence to HEp-2 cells, and Verotoxin production. Ten sporadic cases of EPEC-associated diarrhea, severe enough to require hospitalization in each instance, were present among 105 patients in whom EPEC were identified in stools. Of the 10 cases, 9 were evaluated in more detail. In contrast to the first case, in the prospective study E. coli were cultured from duodenal aspirates in only 1 patient and enteroadherent organisms were not present on careful review of small bowel (0/9) and rectal (0/7) mucosa. Hemolysin production (9 of 10 EPEC strains), mannose-sensitive hemagglutination (7/10), hydrophobic cell surface properties (0/10), adherence to HEp-2 cells (7/10), and production of Verotoxin (0/10) did not distinguish the one enteroadherent EPEC from the nine EPEC strains in which in vivo enteroadherence was not documented. In this study of sporadic cases of EPEC-associated diarrhea in young children, bacterial colonization of the small bowel and enteroadherence in vivo could not routinely be demonstrated. In addition, those laboratory assays of bacterial virulence that were evaluated did not distinguish the adherent strain from nonadherent EPEC strains.

Bacterial Adhesion↗
PubMed1989

Iron deficiency anemia in an athlete associated with Campylobacter pylori-negative chronic gastritis.

A 14-year-old athletic boy with a 1-year history of decreased exercise tolerance presented with unexplained iron deficiency anemia. Panendoscopy, colonoscopy, and barium contrast studies of the gastrointestinal tract were normal. However, persistent uptake of radionuclide using a 99mtechnetium-sucralfate scan suggested inflammation localized to the stomach. Mucosal biopsies demonstrated acute and chronic gastritis that was not associated with the presence of Campylobacter pylori.

Adolescent↗
PubMed1989

Clinical features of gastroduodenal Crohn's disease in adolescents.

Ten cases of gastroduodenal inflammation were diagnosed by endoscopy among a series of 196 children with evidence of Crohn's disease involving other regions of the intestinal tract. Endoscopic and histologic confirmation of upper gastrointestinal tract involvement was performed only in those cases with suggestive symptoms. The mean age at presentation in the 10 cases with gastroduodenal inflammation was 14.6 +/- 1.9 (+/- SD) years, with involvement identified at the time of initial diagnosis of Crohn's disease in five of the 10. Eight of 10 cases occurred in boys. The major presenting symptoms were weight loss in five cases, epigastric pain in three, and recurrent vomiting in two. Hematemesis and melena occurred in only one of the 10 cases. Endoscopic and histological evidence of mucosal inflammation was seen in all 10 cases. Three of 10 cases had noncaseating granuloma present in biopsies of the stomach or duodenum. Two cases also had endoscopic and histological evidence of esophageal involvement. All cases were initially treated with oral corticosteroids, and in each instance a good clinical response was noted. Sucralfate (n = 1), 6-mercaptopurine (n = 1), and H2 receptor antagonists (n = 3) were used as adjunct therapy. After follow-up for 2.7 years (range, 0.5-5.5 years), none of the 10 cases required surgical intervention. Therefore, at least in the short-term, the outlook for adolescents with gastroduodenal Crohn's disease appears to be good and their medical management need not differ from those patients with Crohn's disease involving only more distal portions of the small intestine.

Adolescent↗
PubMed1989

Long-term storage of Campylobacter pylori.

A reproducible method for long-term storage of Campylobacter pylori has been previously described. We cultured 10 strains of C. pylori in brucella broth that was supplemented with 10% fetal bovine serum. After incubation for 24 h, 10% glycerol and an additional 10% fetal bovine serum were added to the cultures, which when then held in storage at -70 degrees C. After 6 months, each of the strains remained viable. This technique, therefore, represents an excellent method for long-term storage of C. pylori isolates.

Campylobacter↗
PubMed1989

Adherence of vero cytotoxin-producing Escherichia coli serotype O157:H7 to isolated epithelial cells and brush border membranes in vitro: role of type 1 fimbriae (pili) as a bacterial adhesin expressed by strain CL-49.

Vero cytotoxin-producing Escherichia coli of the serotype O157-:H7 have recently been associated with sporadic cases and outbreaks of hemorrhagic colitis and with the hemolytic-uremic syndrome. E. coli O157:H7 strains adhere to human epithelial cells in tissue culture and to the intestine of orally infected rabbits. To determine whether E. coli O157:H7 adhere to normal post-natal human epithelial cells, we isolated buccal epithelial cells from healthy adult volunteers and isolated ileal enterocytes and colonocytes from histologically normal margins of surgical resection specimens. Apical brush border membranes from the distal ileum and colonocytes of the proximal colon were also prepared from post-weaning rabbits. Binding of five E. coli O157:H7 strains to epithelial cells and brush border membranes was determined by two complementary methods: firstly, under phase contrast microscopy and secondly, by quantitating adherence of radiolabelled bacteria to substrates that were bound to polystyrene microtiter wells. Under incubation conditions used previously to document in vitro adherence of other diarrheagenic E. coli, only the one type-1 fimbriated E. coli O157:H7 strain, designated CL-49, adhered to isolated human and rabbit epithelial cells. In contrast, binding of 4 non-type-1 fimbriated O157:H7 strains could not be demonstrated. Adherence of the fimbriated E. coli O157:H7 strain was saturable and varied with pH and temperature of the incubation medium. Adherence of bacteria to rabbit ileal brush borders was mediated by binding of bacteria to alpha-linked mannosyl residues present on surface glycoproteins.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Systemic perfusion: a method of enhancing relative tumor uptake of radiolabeled monoclonal antibodies.

We evaluated the feasibility of systemic vascular perfusion with saline (mimicking plasmapheresis) as a method to enhance tumor-specific monoclonal antibody (MoAb) tumor/background ratios. Initially, groups of rats were injected intravenously (i.v.) with 131I-5G6.4 MoAb (murine IgG2aK reactive with ovarian carcinoma). These animal's radioactivity levels were determined by dose calibrator and they were imaged before and after perfusion which was conducted at 4 or 24 h post-antibody injection. Animals were sacrificed after perfusion, as were controls, and normal organ radioactivity levels determined. In addition, nude mice bearing HTB77 ovarian cancers subcutaneously were injected i.v. with 131I-5G6.4 MoAb and were imaged before and after systemic perfusion with saline 24 h post-5G6.4 injection. Perfusion in rats dropped whole-body 5G6.4 levels significantly at both perfusion times (P less than 0.0005). The drop in whole-body radioactivity with perfusion was significantly greater for the animals perfused at 4 h post i.v. 5G6.4 antibody injection (48.3 +/- 5.1%) than for those perfused at 24 h post i.v. antibody injection (32.9 +/- 2.9%) (P less than 0.025). In the nude mice with ovarian cancer xenografts, gamma camera images of tumors were visually and quantitatively (by computer image analysis) enhanced by perfusion, with a 2.33-fold greater decline in whole body uptake than in the tumor (P less than 0.05). These studies show that (1) much background antibody radioactivity can be removed using whole-body perfusion with saline, (2) that the decline in whole body activity is larger with 4 than 24 h perfusion and (3) tumor imaging can be enhanced by this approach.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗