Biomedical subjects

B Pozzetto

Publications and source records attributed to B Pozzetto.

At least 109 records · Page 6Linked to original sources

PubMed1988

[Cytomegalovirus (CMV): virologic protocols for transplantation].

After transplantation, the frequency of reactivation (or superinfection) by CMV is high. Less frequent, but more severe, is the primary form of the disease. The virological procedure to follow up the graft recipients includes: 1) The detection of the infectious virus and/or its antigens in urine, blood, bronchial secretions or brushing, bronchiolar and alveolar washings, ... The laboratory will perform a rapid culture for detection of early CMV antigen (24-72 h) associated with the more classical long-term culture, a reliable but slow method (2-3 weeks). 2) The detection of antibodies, primarily IgM, or even IgA. The usual ELISA for IgG and ELISA modified by addition of an immunocapture on a solid phase are the more reliable techniques. As a rule, the pattern IgM+/IgG- is common for the primary infection. In the case of reactivation (or superinfection), the pattern may be either IgM+/IgG+ or IgM-/IgG+. In the latter case, the increase of the IgG during the next weeks will bring evidence of a reactivation process.

Antibodies, Viral↗

PubMed1988

Sero-epidemiological survey for toxoplasmosis in Burundi.

The first sero-epidemiological survey for toxoplasmosis in Burundi was conducted in 1985. The global prevalence among 622 subjects tested in ELISA and IFI was 44.1% with a higher rate in men (49.6%) than in women (39.2%, p less than 0.01). The highest prevalences were observed in rural areas with intensive farming activities: the crest (57.9%), the plain (53.3%). The central platform, where people and farming activities are widespread, had a lower prevalence (29.3%, p less than 0.001). The risk of infection is much lower in urban people with high levels of hygiene (22.4%) specially in women (13%), than in those of poor condition (45%, p less than 0.001). These data suggest that toxoplasmic infection is mainly due to oocysts ingestion associated with low levels of hygiene and to a lesser extent to meat consumption in men.

Adolescent↗

PubMed1987

[Fulminating hepatitis A in children. Apropos of 4 cases].

We report four cases of fulminant hepatitis in children (4 to 15 years) who developed an hepatic encephalopathy grade III to IV, 4 to 13 days after the onset of their illness. Three patients recovered without sequelae. The complications were neurological: one child showed elevation of the intracranial pressure, successfully treated after monitoring of extra-dural pressure; one suffered from cerebral death. Hepatitis A was diagnosed by the presence in serum of the IgM component of hepatitis A antibody, but another etiologic factor was present in two cases: an halothane anesthesia and an Epstein Barr virus infection which could explain the severity of the hepatitis.

Adolescent↗

PubMed1987

Live poliovirus vaccine in patients with chronic glomerulonephritis: effects on renal function and specific antibody response.

Twenty-one patients with chronic glomerulonephritis (GN) (5 with renal failure) received three doses of live trivalent poliovirus vaccine administered orally. The effect of the polio vaccination on the renal function and the titers of antibodies to poliovirus were studied. No significant consequence was observed in renal disease. Before vaccination, titers of poliovirus type 1 and 3 antibodies were significantly decreased as compared to healthy adult subjects. After vaccination, the patients exhibited a significant rise in poliovirus antibody titers for the three serotypes, although some of them failed to develop a fourfold or greater antibody rise to at least one of the three serotypes, especially in the group of patients with renal failure. These results indicate that live poliovirus vaccination is not deleterious in patients with GN and can provide a good protection.

Adolescent↗

PubMed1986

Rapid diagnosis of echovirus 33 infection by neutralizing specific IgM antibody.

In 1982, we isolated 20 strains of echovirus type 33 (EV33) from 18 patients. We studied the humoral response to EV33 of 2,437 subjects from whom at least one serum was available during the same year. In 388 subjects with the neutralizing antibody level at 64 or more, we assayed the EV33 IgM antibodies by seroneutralization test after fractionation of sera by ion exchange chromatography. One hundred ninety-five subjects (8.0%) had a high titre (greater than or equal to 32) of EV33 IgM antibodies, which was considered as evidence of recent infection. The EV33-positive IgM fractions were assayed against five other enteroviruses. Sixty percent of the IgM fractions did not cross-react with any of the five serotypes, 8.7% cross-reacted with at least one serotype but with predominant EV33 IgM response, and 31.3% had an equivalent or greater amount of non-EV33 IgM antibodies; the type specificity of the assay was directly related to the age of the subjects. These findings suggest that determination of neutralizing specific IgM antibody is a sensitive and rapid test for the diagnosis of enterovirus infections, especially in young people.

Adult↗

PubMed1986

[Immunization against interferon in man].

We have summarized 14 human cases with antibodies to interferon (anti-IFN) reported in the literature. In 4 cases, the patients developed auto-antibodies without any injection of exogenous interferon (IFN). In most cases, antibodies were directed against alpha IFN (13/14) and especially against recombinant alpha 2 IFN (8/14). When tested, antibodies to IFN were always IgG. In a few subjects, the IFN system has been studied more completely with the following results: the competent cells are able, after induction, to produce IFN; the endogenous IFN is neutralized by the antibodies to IFN; the antibodies to IFN are able to inhibit the interaction of IFN with its specific cellular receptors. Clinically, the raising of an anti-IFN immunization does not seem to impair the antiviral or antitumoral effects of IFN. These data can be related to the relative low neutralizing titres of antibodies to IFN with regard to levels of IFN produced at the site of the viral infection. We discuss the putative benefit of antibodies on the availability of circulating IFN and the possible role of antibodies to IFN in autoimmune diseases.

Adolescent↗

PubMed1986

[Incidence of Mycoplasma pneumoniae infection in a population of hospitalized patients during an epidemic].

During an outbreak with Mycoplasma pneumoniae, a serological survey was performed with 3,165 sera from 1,900 hospitalized patients over a 33 months period. Four hundred and eleven patients exhibit serological pattern suggestive for a recent infection. The main points are the following: the infection was more frequently (21.6%) detected in females than males, in the patients 5 to 19 years than in the other age groups; the incidence of the infection is the same in the group of patients hospitalized for extra-respiratory syndromes compared to respiratory infections; children and teen-agers exhibit the higher antibody titers; no modification of the type of infection was found in relation with age groups; the antibody titers are higher when patients are hospitalized with respiratory diseases, whatever their age group may be; there is no relation between sex and the type of infection, pulmonary or extra-pulmonary; a surprisingly high incidence of infections was detected in patients hospitalized with renal failure.

Adolescent↗

PubMed1985

Role of sex and early interferon production in the susceptibility of mice to encephalomyocarditis virus.

Adult female Swiss mice showed a greater resistance to intraperitoneal (i.p.) infection with encephalomyocarditis virus (EMCV) than male mice. This difference was not observed in weanling mice, in castrated adult mice or in adult mice injected intracerebrally. Administration of antibody to mouse interferon alpha/beta enhanced the virulence of EMCV for both sexes and no difference was then observed in susceptibility between male and female mice. Six h after EMCV infection, serum interferon titres were higher in adult female mice than in male mice. There was a close correlation between the early serum interferon titre (at 6 h) and survival of EMCV-infected mice. No differences in serum interferon titres were observed between male or female weanling mice or castrated adult mice. Potent preparations of exogenous interferon provided the same degree of protection against EMCV infection in male and female mice. We conclude that the more marked early interferon response of female mice to i.p. EMCV infection is one of the important factors underlying the differential susceptibility to EMCV. It is possible that the interferon system is also involved in the reported greater prevalence of picornavirus infections of men compared with women.

Age Factors↗

PubMed1984

[Gm allotype HLA antigens and T lymphocyte sub-populations in a group of patients having a positive Coombs test under treatment with alpha-methyldopa].

We analysed HLA-A, B, DR antigens and Gm allotypes in 45 Caucasian patients treated by alpha methyl dopa. 30 had a positive antiglobulin direct Coombs test of the pure IgG type and 15 showed no erythrocyte antibody. We found no difference in the HLA and Gm gene frequencies between the 2 patient groups and the normal control group (nb 104). Furthermore we appreciated the T cell subsets in 11 Coombs positive patients. They showed an increase of the helper/suppressor T cell ratio, due to a significant decrease of the suppressor T cell subset. These data are compatible with Kirtland findings which demonstrated a methyl dopa inhibition of suppressor lymphocyte function. However they do not support the hypothesis that genetic factors may have a role in the susceptibility of patients to methyl dopa induced suppressor-cell disfunction.

Adult↗

PubMed1984

Characteristics of autoantibodies to human interferon in a patient with varicella-zoster disease.

A patient with varicella-zoster disease was found to have antibodies to human interferon. These antibodies included all IgG subclasses, showed a high combined affinity (average dissociation constant, 10(-11)M), and were present in serum at a concentration of 10(-9)M. The antibodies neutralized the activity of a series of human alpha-interferons prepared from recombinant DNA as well as that of naturally occurring mixtures of alpha-type interferon prepared by viral stimulation of human cells. Examination of the patient's lymphoid cells revealed normal production of interferon and normal expression of interferon receptors. Interferon from the patient's cells was neutralized by her serum. The neutralizing capacity of this serum was analyzed with regard to levels of interferon previously detected in patients with varicella-zoster infections.

Aged↗

PubMed1981

The respective advantages of complement fixation and ELISA for routine diagnosis of cytomegalovirus infection.

The results of CF and ELISA tests for cytomegalovirus performed on 270 sera of hospitalized patients show a positive correlation. As a general rule, ELISA is more sensitive than CF, except for a few sera collected from patients with immunological disorders. When two sequential sera are available, the CF remains a reliable and inexpensive method. But when only one serum can be obtained, the probability of an active CMV infection can be estimated on the IgM/IgG ratio. In 26% of the patients, this ratio was greater than or equal to 1. The ELISA is twice as expensive as the CF test. To reduce its cost, a simple method for preparing ELISA antigen from commercially-obtained CF antigens is described.

Adolescent↗

PubMedDate not supplied

Competition binding studies with biotinylated echovirus 11 in cytofluorimetry analysis.

Competition binding studies between viruses are usually performed with radiolabelled probes. In this report, a cytofluorimetric method using biotinylated echovirus (EV) 11 is described for the study of competition of enteroviruses for a common cell receptor site. An N-hydroxysuccinimide ester biotin spacer arm was used for biotinylation of CsSO4-purified EV 11. Biotinylation did not change the infectivity of the virus (attachment to and replication in susceptible cells). With the exception of EV 22 and EV 23, all the echovirus serotypes and also coxsackievirus A9 (CA 9) were able to inhibit the absorption of biotinylated EV 11 onto cells. The taxonomic implications of these findings are discussed.

Binding, Competitive↗

PubMedDate not supplied

Protective effect of a monoclonal antibody specific for an echovirus cellular receptor in human fibroblast and simian kidney cell lines.

We previously reported that infection of KB cells by echoviruses (EV) was inhibited by a KB-derived EV receptor murine monoclonal antibody (mAb 143). This antibody enabled the identification of a cellular receptor common to all echoviruses (with the exception of EV-22 and -23) and coxsackievirus (CV) A9, but different from the receptor of other picornaviruses. We now present results of cell protection assays conducted with human and simian cell lines different from the KB cell line used for production of mAb 143. When human embryonic lung fibroblasts were pretreated with 150 micrograms/ml of mAb 143, EV-11 and CV-A9 were completely inhibited (more than a 2-log difference compared to untreated cells). When the cell protection experiments were performed with Vero cells, the same results were observed with EV-33, but not with EV-22. The protection afforded human fibroblast cells by mAb 143 persisted for at least 5 days after 2-h exposure to 100 TCID50 of EV-11. These results suggest that EV receptors can be effectively blocked for prolonged periods in susceptible cells.

Animals↗

PubMedDate not supplied

Characterization of a non-structural 147-kDa precursor polypeptide of echovirus 33 and its immunogenicity in man.

Zinc chloride (0.9 mM)--an inhibitor of the processing of the initial polypeptides of Picornaviridae--was used to accumulate large precursors of echovirus 33 (EV33) and notably two proteins of 147- and 97-kDa. Polyclonal hyperimmune sera were raised in mice against these polypeptides and assayed by immunoblotting against EV33-infected cells blocked or not with ZnCl2, showing that protein 147--2ABC3ABCD according to the L434 convention--can be considered to be the precursor of the two non-structural proteins P2 and P3. Sixty-three serum specimens from subjects exhibiting varying antibody status against EV33 by seroneutralization were investigated by immunoblotting against an EV33 ZnCl2-blocked antigen. Some subjects infected with EV33 were shown to elicit antibodies which recognize the non-structural precursor polypeptides, a fact whose clinical significance needs further evaluation.

Animals↗

PubMedDate not supplied

Aplastic anemia after Mycoplasma pneumoniae infection: a report of two cases.

Two very unusual cases of aplastic anemia complicating mycoplasma infection are described. Each patient had preexisting hematologic abnormalities at the time of the infection: reactive hemophagocytic syndrome in one, and autoimmune hemolytic anemia associated with cold autoantibodies in the other. This adds another entity to the protean manifestations of Mycoplasma pneumoniae infection.

Anemia, Aplastic↗

PubMedDate not supplied

[Substernal goiter: a diagnostic and therapeutic problem. (Report of 39 surgically treated cases)].

Substernal goiter is a rare pathology and its definition varied from author to author. We considered substernal the goiter that has the larger diameter below the thoracic inlet, in accord to definition of Valdoni (1957). The authors examined retrospectively 40 cases of endothoracic goiter, that represent 6.1% of patients operated on thyroid. Surgical access was in 35 cases a cervical collar incision; in 2 patients was necessary to associate a median superior sternotomy and in another patient a lateral thoracotomy. In 3 patients the access was a median sternotomy and in the last patient a posterolaterally thoracotomy. The authors carried out 12 total thyroidectomy (30.7%), 15 subtotal thyroidectomy (38.6%), 10 total lobectomy (25.6%), 2 subtotal lobectomy (5.1%). No mortality was observed. The morbility was represented by 5 monolateral temporary palsy of recurrent laringeal nerve, 6 transitory hypocalcemia, 1 tetanic syndrome, 1 transitory arrhythmy. The follow-up was managed on 35 patients (89.7%). We observed 1 definitive hypoparathyroidism, 1 paralysis of recurrent laringeal nerve, 1 mediastinic relapse. One patient was operated on total thyroidectomy 14 years after the first surgery for a differentiated carcinoma. In conclusion the treatment of substernal goiter is surgical. Debating point is the entity of exeresis. We think that the first choice operation is thyroidectomy, done through a cervical collar incision. Occasionally sternotomy or thoractomy are necessary.

Female↗

PubMedDate not supplied

[An occult pancreatic insulinoma: radio-guided surgery with 111-In-octreotide. A case report and review of the literature on pre- and intraoperative diagnosis].

INTRODUCTION: Pancreatic insulinoma is a small, rare neoplasm; its radical therapy is surgical enucleation or resection. Although clinical diagnosis is simple, instrumental and radiological localization is still difficult (occult insulinoma: 10-20%). MATERIAL AND METHODS: The authors present the case of a 71-year-old patient suffering from relapsing vertigo syndrome, derangement and transient lypothymia after strong physical activity. ECG, encephalic and abdominal C.T., eco-color-Doppler of epiaortic vessels failed to identify any pathological features. Laboratory tests only revealed that basal glycemia was always lower than normal. Insulinoma was strongly suspected following the outcome of dosages of insulin and C-peptide in the serum and was confirmed after a supervised fast test (72 h). Once the biochemical diagnosis had been reached an abdominal eco, C.T., a selective and superselective angiography and echo-endoscopy were carried out to locate the tumor site but results were negative. Only somatostatin-receptor scintigraphy with 111 In-octreotide detected a catchment area (diameter: 3 cm) to the right of the hypochondrium, anterior to the kidney and caudal to the left hepatic lobe. RESULTS: During laparotomy a hand-held gamma detecting probe (C-Trak) was used to detect in situ tumour binding of the radiolabelled octreotide and a neoplasm was identified and enucleated from the pancreatic head (diameter: 7 mm), undistinguishable from the surrounding parenchyma. Postoperative signal checks of the surgical field and of the neoplasm revealed, in the first, the absence of captation and, in the second, maximal captation. Histological findings confirmed the nature of the neoplasm: an insulinoma with a ring pattern. Two years after surgery the patient is in good health, with no signs of relapse. CONCLUSIONS: Radio-guided surgery with labelled octreotide makes it possible to pinpoint small insulinomas, locate occult neoplasm, verify the completeness of surgical excision in the field and in the surgical piece, by comparing the different captation of labelled octreotide and check neoplasm multicentricity and any metastases.

Aged↗

PubMedDate not supplied

[Surgical treatment of differentiated carcinoma of the thyroid. Follow-up of 99 cases].

The surgical treatment of differentiated thyroid carcinoma continues to be a matter of considerable debate in terms of defining the appropriate extent of thyroid or lymph node resection to ensure optimal patient survival. Whereas, at organ level, the majority of surgeons are in favor of total thyroidectomy, both the extent and timing of lymphadenectomy remain controversial issues. In the light of this, the Authors have conducted a retrospective study in 99 consecutive patients with differentiated thyroid carcinoma. As regards the distribution of the cancers in terms of TNM staging, 60 were stage I, 27 stage II, 11 stage III and 1 stage 4. Almost all the patients underwent total thyroidectomy. Lymphadenectomy was performed at the same time as thyroidectomy in papillary cancers when the nodes were clinically palpable and at a later date in those cases where the nodes subsequently became palpable at follow-up. The in-hospital mortality was 3% and was unrelated to the operation. The median follow-up was 95.8 months (7.98 years). Sixty-nine patients are still alive (71.8%), 66 of them disease-free (68.7%) and 3 with lymph node metastases (3.1%). Our results and those of other investigators suggest that total thyroidectomy should be the first therapeutic choice in differentiated cancers of the thyroid, but allow us to draw no firm conclusions regarding the controversial issue as to which type of lymphadenectomy can best ensure patient survival. To solve this problem we believe that multicenter randomized trials will be necessary. However, progress in molecular biology and tumor genetics is likely to enable us to identify new prognostic factors which may prove useful when deciding on the most appropriate therapeutic option.

Adenocarcinoma↗