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Biomedical subjects

E Brocchi

Publications and source records attributed to E Brocchi.

At least 55 records · Page 3Linked to original sources
PubMed1992

Value of endoscopic ultrasonography in the management of portal hypertension.

Using endoscopic ultrasonography (EUS) a large part of the portal venous system can be visualized. In 40 patients with portal hypertension (PH) and in 48 control subjects EUS displayed the azygos, splenic, mesenteric and portal veins in both groups. However, esophageal and gastric varices, peri- esophageal and peri-gastric collateral veins and submucosal gastric venules were displayed only in patients with PH. EUS was inferior to endoscopy for detecting and grading esophageal varices (p less than 0.0005), but superior in the detection of varices in the fundus of the stomach (p less than 0.0005). EUS cannot be considered a reliable method for the study of esophageal varices: it has an overall sensitivity of 50%, does not permit flow measurements, and does not provide information that could be used to estimate the risk of bleeding. EUS has been demonstrated to be superior to endoscopy in the diagnosis of gastric varices. This finding is extremely important for the optimal selection of treatment of patients with portal hypertension. EUS can detect portal hypertensive gastropathy; thus inflammatory gastritis can be more easily distinguished from congestive gastropathy and therapeutic decisions are strongly influenced.

Azygos Vein↗
PubMed1992

Extensive antigenic diversification of foot-and-mouth disease virus by amino acid substitutions outside the major antigenic site.

The antigenic sites A and C (the G-H loop and the C terminus, respectively) in VP1 of foot-and-mouth disease virus (FMDV) have been considered the immunodominant regions of the virus involved in the induction of protection. Other antigenic sites have been described but their involvement in protection has not been established. Here we report that two closely related but serologically different FMDVs (the field isolate C3 Argentina/84 and the vaccine strain C3 Resende Br/55) have identical A and C sites but differ as other antigenic sites. Such differences have been documented by reactivity with a panel of 28 monoclonal antibodies (MAbs). The two viruses reacted to the same extent with each of 13 MAbs which recognized epitopes within sites A or C, but reacted differently with six out of 15 MAbs that recognized other sites. Accordingly, sequencing of the entire region coding for the capsid proteins, for both viruses, revealed four amino acid substitutions at three antigenic sites other than A and C. The results suggest that identity of sites A and C may not be sufficient to induce cross-protection, and provide the first evidence of significant antigenic diversification of FMDV in the field mediated by amino acid substitutions outside sites A or C.

Amino Acid Sequence↗
PubMed1992

Protective immune response against foot-and-mouth disease.

The causative agents of foot-and-mouth disease (FMD) are small icosahedral viruses of the Aphthovirus group within the Picornaviridae family. There is no evidence that these viruses infect cells of the immune system or otherwise interfere detrimentally with their function; additionally, it has not been possible to relate cytotoxicity reactions against virus-infected cells to the efficacy of the immune response against FMD virus infection. In contrast, there is a close association between FMD virus antibody and the protective immune response (10, 14, 15, 20, 24, 25, 29-32). Induction of this antibody is dependent on the structure of the viral antigenic sites (7-9, 11, 18) and on the concomitant presence of Th-lymphocyte epitopes (4, 5, 7, 8), although a Th-lymphocyte-independent response has been reported (2). Recent work by Piatti et al. (26) showed that the immune response induced by FMD virus was only Th-lymphocyte dependent when low doses of antigen were used. This latter work was performed in mice, and it is not certain that a similar situation would be found in cattle. As for the major effector immune defense, this relies on the interaction between antibody-virus complexes and the phagocytic cells of the reticuloendothelial system (17, 19).

Animals↗
PubMed1992

Study of bovine herpesvirus type 1 strains with monoclonal antibodies.

Fourteen strains of bovine herpesvirus type 1 (BHV-1, IBRV) representing all three groups of BHV-1 (BHV-1.1, BHV-1.2, BHV-1.3) were studied by ELISA using 106 monoclonal antibodies (Mabs) produced against BHV-1. On the basis of the ELISA, the Mabs could be divided into three groups. The first group (40 Mabs, 38%) reacted with all strains, the second group (43 Mabs, 41%) with the respiratory and genital strains (BHV-1.1 and BHV-1.2) while the third group (23 Mabs, 22%) only with the respiratory strains. Only 5 out of the antibodies neutralized respiratory and genital strains, and none of them neutralized the encephalitogenic strains (1.3). Three Mabs selected from each of the 3 groups, and the above five neutralizing strains were studied by Western blot. Antibodies of groups 1 and 3, and two neutralizing antibodies bound to a 90k protein (gpIII), whereas members of group 2 and 3 neutralizing antibodies reacted with a 74k and a 130k protein (both gpl). The results indicate that reactivity with monoclonal antibodies is as suitable for the classification of BHV-1 strains as is restriction endonuclease (RE) analysis but it cannot distinguish between subgroups within the groups.

Animals↗
PubMed1992

Differential cleavage of surface proteins of Borrelia burgdorferi by proteases.

The differential cleavage of surface proteins of Borrelia burgdorferi IRS strains by several proteases was examined. Proteinase K, trypsin, chymotrypsin and thermolysin all cleaved the outer surface protein B (OspB) to undetectable levels by Coomassie Brilliant Blue staining, whereas some residual protein was detected by immunoblotting with polyclonal and monoclonal antibodies. Not even antigenic fragments were detectable by immunoblotting with 1A8 monoclonal antibody reactive with OspB. Less effective or ineffective was the cleavage of OspB by V8 protease and proteinase A, respectively. The outer surface protein A was cleaved only by proteinase K. The effect of trypsin on borreliae viability and adhesion to cultured cells was also studied. The trypsin treatment of borreliae did not impair the viability of organisms which continued to synthesize the cleaved OspB. The attachment of B. burgdorferi to HEp-2 cells was reduced by 41% after treatment with trypsin, whereas preincubation of borreliae with monoclonal antibody 1A8 and guinea pig immune serum reduced the adhesion of borreliae to the cells by 32% and 87%, respectively.

Antibodies, Monoclonal↗
PubMed1991

Partial characterization of an 89-kDa highly immunoreactive protein from Chlamydia psittaci A/22 causing ovine abortion.

An 89-kDa immunogen from Chlamydia psittaci A/22 causing ovine abortion was partially characterized. The 89-kDa protein, localized on the outer membrane complex of chlamydiae, was synthesized relatively early in the developmental cycle. The protein contained cysteine but was not extensively cross-linked by disulfide bonds. Treatment with proteases apparently did not cleave the protein. The infectivity of strain A/22 was partially (60%) reduced by treatment of chlamydial elementary bodies with monoclonal antibody BS/89 specifically reacting with the 89-kDa antigen. Species-specific as well as strain-specific antigenic determinants were present on the 89-kDa protein.

Abortion, Veterinary↗
PubMed1991

Guillotine needle biopsy as a supplement to endosonography in the diagnosis of gastric submucosal tumors.

The presumptive diagnosis of gastric submucosal tumors can be made by endoscopic ultrasonography (EUS) but histological confirmation is still required. A special guillotine biopsy device (Flexi-Temno) which enables collection of adequate submucosal samples by the endoscopic approach was therefore evaluated. After visualization by EUS the guillotine needle biopsy was performed in 21 patients with submucosal tumors of the stomach. There were 2 failures in 2 patients with leiomyomas. The diagnosis suggested by EUS was confirmed by guillotine biopsy in 17 cases. Guillotine biopsy detected 2 cases of unsuspected leiomyosarcoma which were confirmed surgically. In cases of solid submucosal tumors confirmed on EUS, the guillotine needle biopsy enables a definitive histologic diagnosis. Thus malignancies can be detected when EUS findings are not significant.

Biopsy, Needle↗
PubMed1991

Binding characteristics of monoclonal antibodies raised against bovine growth hormone.

Monoclonal antibodies have been raised against pituitary bovine growth hormone using the hybridoma procedure. The binding characteristics of the seven selected monoclonal antibodies toward the antigen molecule in its native, chemically or enzymatically treated form have been studied. The reactivities of the monoclonal antibodies with growth hormones from other species and bovine prolactin have also been investigated. The epitopes recognized by four of the produced monoclonal antibodies are conformational, whereas two other monoclonal antibodies bind to sequential determinants. Three antibodies define immunological sites located between residues 6-124 of the bovine growth hormone molecule, and one of this antibody shows higher affinity to human than bovine growth hormone. The immunoreactivity of one monoclonal antibody is enhanced by the previous binding of the antigen to polyclonal antibodies, probably because of a localized conformational change of the bovine growth hormone molecule. This antibody also shows cross-reactivity with all the homologous hormones tested, indicating to recognize a highly conserved antigenic determinant.

Animals↗
PubMed1991

Immunological characterization of a low molecular mass polypeptidic antigen of Borrelia burgdorferi.

The presence of a low molecular mass polypeptidic antigen in Borrelia burgdorferi was described. The protein was exposed at the bacterial surface since it was clearly identified by mAb 3H4 using the immunofluorescence test performed with living bacteria. This antigen was cleaved by proteinase K treatment, whereas it was resistant to the action of chymotrypsin, trypsin and thermolysin. Western blotting analysis of the immunological reactivity of this antigenic structure performed using monoclonal antibody, mouse-immune ascitic fluids raised against B. burgdorferi and other spirochetes, sera from patients with Lyme disease and other infirmities in which false positive results in serological tests for B. burgdorferi have been described, demonstrated that this protein expresses only species-specific epitopes which may be recognized during human B. burgdorferi infections.

Animals↗
PubMed1990

Pericarditis: a probably overlooked complication of endoscopic variceal sclerotherapy.

Two cases of acute pericarditis following endoscopic variceal sclerotherapy (EVS) that were resolved with conservative management are described. This complication arose respectively one and three days after EVS. The possible pathogenesis is the involvement of the pericardium in an inflammatory reaction that develops in the esophageal wall and surrounding tissues. Only five cases have been previously reported in the literature; the authors suppose that this fact may be due to the mild symptoms presented by the patients, which may result in underestimation of this complication. The technical details of EVS in the seven patients with pericarditis were analyzed, but no common etiologic factor was found. The authors strongly advise regular checks for clinical and instrumental signs of acute pericarditis after every session of EVS, so that appropriate management can be undertaken in an early phase and, if necessary, further EVS sessions delayed, in order to avoid cardiac tamponade or constrictive pericarditis.

Acute Disease↗
PubMed1990

A single amino acid substitution affects multiple overlapping epitopes in the major antigenic site of foot-and-mouth disease virus of serotype C.

Neutralizing monoclonal antibodies (nMAbs) elicited against foot-and-mouth disease virus (FMDV) of serotype C were assayed with field isolates and variant FMDVs using several immunoassays. Of a total of 36 nMAbs tested, 23 recognized capsid protein VP1 and distinguished at least 13 virion conformation-independent epitopes involved in neutralization of FMDV C. Eleven epitopes of FMDV C-S8c1 have been located in segments 138-156 or 192-209 of VP1 by quantifying the reactivity of nMAbs with synthetic peptides and with nMAb-resistant mutants of FMDV C-S8c1 carrying defined amino acid substitutions. The main antigenic site of FMDV C-S8c1 (VP1 residues 138 to 150) consists of multiple (at least 10), distinguishable, overlapping epitopes. Some amino acid replacements abolished one of the epitopes, whereas other replacements affected several epitopes in this region. The conservative substitution His(146)----Arg, found in many nMAb-resistant mutants analysed, abolished the reactivity of the virus with all nMAbs that recognized epitopes in the main antigenic site of FMDV C-S8c1. This indicates that a minimum genetic change can result in a highly amplified phenotypic effect, as regards the antigenicity of FMDV.

Amino Acid Sequence↗
PubMed1990

Loss of duodenal folds allows diagnosis of unsuspected coeliac disease.

We report three patients with coeliac disease who presented without the classic features of malabsorption and who underwent biopsy and were diagnosed only because of the endoscopic finding of the disappearance of Kerckring's folds in the descending duodenum. This sign constitutes a new and valid aid for the identification of patients with otherwise unsuspected coeliac disease.

Celiac Disease↗
PubMed1990

Protection of the upper gastrointestinal mucosa: the role of antacids.

Experiments performed in animals and in healthy human subjects suggest that antacids increase prostaglandin synthesis and have a cytoprotective effect on gastroduodenal mucosa. To investigate this hypothesis, the ability was evaluated of an antacid containing an aluminium/magnesium hydroxide combination (Maalox TC) to modify prostanoid production at the gastric level in 28 patients with gastric antral ulcer of various sizes in different stages of activity with or without erosive gastritis. After the antacid treatment, a significant prostaglandin E2 reduction was observed, together with a significant 6-keto-prostaglandin F1 alpha increase, but there was no thromboxane B2 variation at antrum level, nor any significant modification of prostanoid production at body level. The decreased prostaglandin E2 levels, detected after treatment with the antacid combination, may be due to lesion improvement, decreased synthesis or increased catabolism by mucosal cells, to a drop in this prostaglandin production by inflammatory cells. As far as 6-keto-prostaglandin F1 alpha is concerned, the obtained data confirm the results reported by other authors in healthy human subjects. The increase of this prostaglandin could enhance blood flow, resulting in a protective effect.

6-Ketoprostaglandin F1 alpha↗
PubMed1988

Endoscopic demonstration of loss of duodenal folds in the diagnosis of celiac disease.

Among 873 patients undergoing upper gastrointestinal endoscopy for various reasons over a two-year period, four had a loss of Kerckring's folds in the descending duodenum. Endoscopic duodenal biopsy in all four patients revealed subtotal villous atrophy due to celiac disease. We undertook a prospective study to evaluate the extent to which this finding predicted celiac disease in 65 consecutive patients referred for intestinal biopsy. Duodenal folds were absent or markedly decreased in 15 of 17 patients with subtotal villous atrophy and in 8 of 48 patients with partial villous atrophy or normal duodenal mucosa, giving a sensitivity of 88 percent and a specificity of 83 percent for this endoscopic finding with respect to celiac disease. We recommend that all patients undergoing upper gastrointestinal endoscopy be examined for the loss or reduction of duodenal folds and, should this be found, that the examination include duodenal biopsy. The value of this procedure as an aid in the diagnosis of celiac disease should be particularly great in patients with minimal, transient, or unrelated symptoms.

Adult↗
PubMed1988

Impact of endoscopic ultrasonography on diagnosis and treatment of primary gastric lymphoma.

Endoscopic ultrasonography (EUS) allows a visualization in vivo of the gastric wall. Five ultrasonic layers of different echogenicities are displayed; each corresponds to a precise anatomic structure. In gastric diseases this layering evidently changes. In 10 patients with suspected primary gastric lymphoma, EUS showed a characteristic thickening of the second, the second and third layers, or a diffuse, transmural thickening of the entire wall. A precise correlation between the longitudinal and depth infiltration observed at EUS and the surgical finding was seen in all patients. In three cases in which the preoperative bioptic diagnosis was erroneous (two gastritis and one carcinoma) EUS showed a characteristic echographic pattern for lymphoma, which was confirmed at surgery. There was agreement also, in EUS and surgical findings in all patients, about involvement of neighbor organs. It seems possible that in the future EUS could play an important role in detecting, staging, and planning treatment of lymphoma and other gastric tumors.

Adult↗
PubMed1987

Sonographic evaluation of the portal venous system after elective endoscopic sclerotherapy of esophageal varices.

In order to evaluate possible changes in the portal venous system after endoscopic sclerosis of esophageal varices, 25 cirrhotic patients underwent abdominal ultrasonography before the first session of sclerotherapy and after eradication of esophageal varices had been achieved. The caliber of the portal, splenic, and superior mesenteric veins was measured sonographically in each case. Sonographic results were compared statistically before and after sclerotherapy. Neither evidence of significant variations in the caliber of the portal veins nor thrombotic obliteration was seen. These results support the view that sclerotherapy has no significant negative side effects on the portal venous system.

Endoscopy↗