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Biomedical subjects

E Brocchi

Publications and source records attributed to E Brocchi.

At least 73 records · Page 4Linked to original sources

Epitopes on foot-and-mouth disease virus particles. I. Topology.

Monoclonal antibodies (MAb) against an O1 Suisse isolate of FMDV were used to identify epitopes on the virus particle and to determine their relative function. Six major antigenic sites containing one or more epitopes were identified using competition ELISA. An epitope relationship is proposed consisting of a trypsin-sensitive sequential site, termed B2/D9, from the codings for the MAb which reacted with it, which was associated with virus infectivity and is probably at or near to the cell-binding site of the virion; a trypsin-resistant, conformational site 1C6/4C9 MAb reaction at which also resulted in neutralization of virus infectivity; a second trypsin-resistant, conformational site 3C8, where again MAb reaction neutralised virus infectivity; a third trypsin-resistant, conformational site 6C3/2G5, at which MAb-dependent neutralisation of virus infectivity was inefficient; a site 3G4, the expression of which was impaired but not destroyed by trypsin treatment, and was not related to virus infectivity; an internal site A8, which appears to be a "12S subunit-specific" site. This work clearly demonstrates for the first time that both trypsin-sensitive and trypsin-resistant neutralisable (infectivity-associated) sites exist on the FMDV particle, and only one of these can be related to the sequential site used to formulate current FMDV peptide vaccines.

Antibodies, Monoclonal↗

Conformational alteration in foot-and-mouth disease virus virion capsid structure after complexing with monospecific antibody.

A mechanism of neutralization of virus infectivity by antibody is described and related to the immune defences in vivo. The interaction of a particular monoclonal antibody with homologous foot-and-mouth disease virus alters the conformation of the virions to permit penetration of staining reagents. A consequence of this structural alteration is that the RNA genome becomes susceptible to dissociation from the capsid proteins. This mechanism of virus neutralization is irreversible and therefore provides an effective in vivo defence measure against virus attack, complementing the enhanced phagocytosis effected through opsonization of virions. With viruses that can replicate in phagocytes, such a mechanism of virus neutralization could provide a major 'specific' immunological defence against virus invasion.

Antibodies, Monoclonal↗

Immunochemical characterization of human liver and heart ferritins with monoclonal antibodies.

A library of 27 murine monoclonal antibodies was obtained by using human liver and heart ferritins as immunogens. The specificity of the antibodies for the two ferritins and their subunits was studied with five different methods. The antibodies elicited by the liver ferritin bound preferentially the immunogen and were specific for the L subunit. Some antibodies elicited by the heart ferritin had characteristics similar to the anti-liver antibodies, other ones bound preferentially the heart over the liver ferritin and were specific for the H subunit. Only two antibodies were able to bind both ferritins and subunits. Some anti-H and anti-L chain antibodies were used to develop and compare four types of immunoassay to quantitate isoferritins. The results indicate that heart ferritin is immunologically more heterogeneous than liver, the H and L subunits having large immunological differences with few, if any, identical epitopes; and that that the architecture of the immunoassays have a strong influence on the crossreactivity of the antibodies with the two isoferritins, probably because H and L chains are not arranged randomly in the assembled protein.

Animals↗

Gastric carcinoid: a clinical and endoscopic assessment of four cases.

We have established a pre-operative diagnosis in four cases of non-secretory gastric carcinoid of the body and fundus presenting as multiple polyps in three patients, and a single polyp mass in the fourth patient. Clinical and endoscopic findings are not specific, and the pre-operative diagnosis was established by means of biopsy or polypectomy. We observed biochemical and histological differences between multiple and single carcinoids, which might indicate different mechanisms of carcinoid pathogenesis.

Adult↗

Detection of portal hypertension and esophageal varices by means of endoscopic ultrasonography.

Endoscopic ultrasonography (EUT) enables not only the visualization of the portal system and of the esophageal varices, as obtained by transabdominal ultrasonography and fiberoptic endoscopy, but also the visualization of intramural and periesophageal collateral veins. Fifteen cirrhotic patients were examined by EUT without complications. When present, esophageal or gastric varices were always detected. In all cases enlarged extrinsic periesophageal veins were visualized, and in 14 of 15 their caliber was correlated with the size of esophageal varices. In three patients examined after sclerotherapy the submucosal veins had disappeared, but extrinsic collateral vessels were patent. EUT will probably become a fundamental technique in the study of portal hypertension and esophageal varices, before and after therapy.

Adult↗

Immune protection against foot-and-mouth disease virus studied using virus-neutralizing and non-neutralizing concentrations of monoclonal antibodies.

Monoclonal antibodies (MAb) against sequential or conformational epitopes on foot-and-mouth disease virus (FMDV) passively protected neonatal syngeneic (BALB/c) mice at dilutions at which they could not neutralize virus infectivity in vitro. The B2, D9, 1C6 and 4C9 MAb, against the Group 1 (sequential) and Group 2 (conformational) epitopes, protected the mice at an antibody:virion molar ratio of between 38:1 and 84:1 (12-18 times lower than that required for neutralization of virus infectivity in vitro). The 3C8 (Group 3) and 6C3 (Group 4) MAb were, respectively, between 5 and 12 times, and between 18 and 40 times, less efficient at protection. There was no consistent correlation between the efficiency of neutralization of virus infectivity in vitro and the protection of neonatal mice against the virus pathogen. Thus, immune protection against FMDV must use mechanisms other than the direct neutralization of virus infectivity by antibody. Complement did not increase the virus neutralization titre of the MAb, but pepsin digestion of the MAb abrogated the enhanced in vivo protection over in vitro neutralization, with little effect on their capacity to neutralize virus infectivity. It is therefore likely that opsonization to a minimum affinity, and subsequent rapid phagocytosis, play a major role in the immune defence against FMDV. This is discussed in terms of the natural host for FMDV and the induction of immunological protection.

Animals↗

Endoscopic electromyography and manometry of the human sphincter of Oddi.

The myoelectric and manometric activities of the sphincter of Oddi were recorded in 8 patients using an original probe passed through the papilla of Vater during duodenoscopy. The sphincter of Oddi's myoelectric activity showed rhythmic bursts of action potentials which appeared in correspondence with the ascending phase of the phasic pressure waves. On the basis of these results, we believe that electromyography could in some cases replace manometry for studying sphincter of Oddi motility, since it avoids pressure perfusion of the bilio-pancreatic tract, with its concomitant risks, and provides sufficient information for motor studies.

Ampulla of Vater↗

Study on coagulation profile of patients with cirrhosis of the liver undergoing elective fibreoptic injection sclerotherapy of oesophageal varices.

In order to establish whether injection sclerotherapy of oesophageal varices could bring about a worsening of the coagulation abnormalities of patients with cirrhosis, the platelet count and the coagulation profile were monitored prior to, then 30 min and 18 h after, the injection in 8 patients undergoing 18 sclerotherapy sessions. Under basal conditions the platelet count, prothrombin activity, normotest and antithrombin III were all reduced; fibrinogen was in the low, and partial thromboplastin time in the high, normal range. A significant shortening of PTT and a further reduction in the platelet count, in the normotest and in fibrinogen occurred after 30 min. On one occasion laboratory evidence of disseminated intravascular coagulation was observed. After 18 h most parameters approached basal values, but the normotest remained persistently reduced. Even though a transient activation of the coagulation process, with consumption of platelets and the liver-dependent clotting factors took place after sclerotherapy in most cases, leading in one to self-limiting disseminated intravascular coagulation, haemorrhagic complications did not occur in our patients. These results suggest that injection sclerotherapy did not lead to clinically significant deterioration of coagulation even in patients with abnormal coagulative function. The observed changes appeared to be self-limiting and confined to the laboratory level in all cases.

Adult↗

Endoscopic manometry in the diagnosis of the postcholecystectomy pain syndrome.

A manometric study of the distal biliary tract was carried out by means of a side-hole perfused catheter passed through the papilla Vateri during duodenoscopy in patients with postcholecystectomy biliary pain not due to stones or inflammation of the biliary tree. The sphincter of Oddi showed in these cases a significantly higher basal tone than in controls with superimposed phasic pressure waves of high amplitude. The basal pressure of the common bile duct was also higher than in controls. These manometric findings may help differentiate the functional papillary stenosis from other causes of the postcholecystectomy pain syndrome and may be useful in settling the question of performing sphincterotomy in these patients.

Ampulla of Vater↗

Ultrasonographic findings in portal hypertension: correlation with the presence and size of oesophageal varices.

This study assesses the usefulness of ultrasonography in the diagnosis of portal hypertension. Several ultrasonographic signs were correlated with the presence and size of oesophageal varices detected by endoscopy in 32 patients suffering from alcoholic liver cirrhosis. Ultrasonography is proposed as a simpler and earlier method for screening of portal hypertension than endoscopy.

Diagnostic Errors↗

[Use of the ELISA (enzyme-linked immunosorbent assay) method in detection of anti-toxoplasma IgG and IgM].

The enzyme-linked immunosorbent assay (ELISA) has been applied for detecting anti-toxoplasma serum IgG and IgM. ELISA was carried out with alkaline phosphatase-labeled anti-IgG and anti-IgM antibodies. Both conjugates specificity was investigated by sucrose density gradient fractionating of an immunofluorescence positive serum and by ELISA testing of all the fractions for IgG and IgM. A good agreement of ELISA results from 400 sera was found when they were compared with others obtained by several serological methods: direct agglutination, complement fixation, IgG/IgM-IIF. Occasionally false-positive IgM-ELISA and IgM-IIF results were observed, probably due to non specific IgM antibodies. Absorption of sera with whole parasites resulted in a removal of specific IgM, whilst false-positive IgM-ELISA reactions were unaffected. ELISA procedure is simple and rapid to carry out in a large scale and it seems to be for routine purposes an adequate substitute for toxoplasmosis IIF test. The possibility to quantitate ELISA results would give the opportunity to standardize the test not only in one, but even among several laboratories.

Agglutination Tests↗

[Endoscopic treatment of obstructive cholangitis].

A long catheter can be positioned in the bile ducts by means of a fibre glass gastroduodenoscope, thus making it possible to drain bile and inject medicaments locally. This technique gives excellent results and is particularly indicated in cases of choledocic lithiasis complicated by cholangitis in order to clear up the infection and send the patient in for surgery in ideal condition.

Aged↗

Serum trypsin-like immunoreactivity after endoscopic retrograde cholangiopancreatography.

Serum trypsin-like immunoreactivity (TLI) was studied in 31 patients before and after endoscopic retrograde cholangiopancreatography. None of the patients developed clinical acute pancreatitis. Generally, the serum TLI peak was observed within the first 6 hours after the examination. Most patients (73%) showed a pathologically high TLI but very high values were not frequent (19%). Successful pancreatic opacification was followed by a significant increase in serum TLI which was pathologically high in nearly all cases (18/20). On the contrary, after cholangiography alone abnormal values were less frequent (4/8) and the increase was not significant. In most patients TLI and amylase responses were in agreement. A significant, though poor, linear relation was found between serum TLI and serum amylase 3, 6 and 12 hours after the examination.

Amylases↗

[Dietetic considerations of the peptic ulcer treatment (author's transl)].

Stated that the alimentary inconguities, the improper mastication and the quickly eaten of foods are to avoid for the direct irritant effect on the stomach, the authors have examinate the various dietetic treatments, imploied for peptic ulcer and they conclude that only during the acute clinical phase more restrictive regimens are necessary. When the patient in on way of recovery, the alimentation must be free in agreement to the tolerance and personal taste using more variety of food. Moreover it's necessary to remember that the patient is not an "ulcer", but "his ulcer" be treated with the psycho-pathological implication correlated.

Acute Disease↗

[The primary empty sella syndrome. A case report study (author's transl)].

The empty sella results from an extension of the subarachnoid space into an intrasellar position with subsequent remodeling of the sella turcica and the flattening of the pituitary gland. The sella turcica is usually enlarged causing the greatest diagnostic difficulty to distinguish it from a pituitary tumor. The most patients with this syndrome usually have normal pituitary function, while about 30% have varying degrees of hypopituitarism. The Authors describe a case report of a man with primary empty sella syndrome come to the medical observation for obesity and hyperglyccemia. The endocrine evaluation performed (TRH test, GN-RH test, T3, T4, FT3, FT4, Arginine test, metyrapone test) were normal. OGTT shows a maturity onset diabetes (glycemia = 160 mg%). This rare clinical association is not well understood. Probably this diabetes is to the interruption of the normal hypothalamo-pituitary neurovascular connection.

Adult↗