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Biomedical subjects

J Icart

Publications and source records attributed to J Icart.

At least 37 records · Page 2Linked to original sources
PubMed1994

Cytomegalovirus (CMV) prophylaxis by acyclovir in pre-transplant CMV-positive renal transplant recipients.

Cytomegalovirus (CMV) infections, either primoinfection or reactivation, remain an important problem in organ transplantation. We therefore designed a prospective study in which pre-transplant CMV-positive renal transplant (RT) patients were randomized to receive for 3 months starting immediately after transplantation either acyclovir or nothing. Between April 1992 and January 1993, 53 cadaveric renal transplantations were performed in our institution. The immunosuppressive regimen included anti-thymoglobulins (ATG), azathioprine, steroids and cyclosporine A. Patients randomized in the acyclovir arm received the drug from day 1 to day 90 (D90) intravenously as long as the creatinine clearance was not above 10 ml/min and per os afterwards (3200 mg/day if the creatinine clearance was above 50 ml/min). CMV viraemia tests were systematically performed every 2 weeks until day 90 or when febrile episodes occurred. The patients were 53 adults who received a RT during the study period; 37 were included in the study of which 19 received acyclovir prophylaxis (group A) and 18, no prophylaxis (group B). The two groups did not significantly differ according to sex ratio, recipient's age, number of CMV-negative donors and number of days on ATG (10.76+/-6.16 vs. 8.28+/-4.21 days). There were significantly fewer viraemia episodes in group A (n = 6) than in group B (n = 13, P < 0.05); nevertheless, the percentage of symptomatic CMV viraemia was the same in both groups (35% vs. 38.5%). The onset of CMV viraemia occurred in the same period in both groups (39+/-13.8 days vs. 34.3+/-15 days; P = NS). The number of rejection episodes in the study period was the same in both groups (8 in each). We conclude from this prospective study that post-RT acyclovir prophylaxis reduces significantly the number of CMV viraemia episodes but does not delay their onset. Furthermore, it has no effect upon the percentage of symptomatic viraemias.

Acyclovir↗
PubMed1991

Detection of Epstein-Barr virus messenger RNA in Reed-Sternberg cells of Hodgkin's disease by in situ hybridization with biotinylated probes on specially processed modified acetone methyl benzoate xylene (ModAMeX) sections.

Microscopic intracellular detection of Epstein-Barr virus (EBV) messenger RNA in Reed-Sternberg cells of Hodgkin's disease (HD) was possible by in situ hybridization, in tissue sections prepared by a method termed modified acetone methyl benzoate xylene (ModAMeX). The ModAMeX method was initially developed for simultaneous optimal preservation of leucocyte differentiation antigens and morphology. Two biotinylated DNA probes, corresponding to the same BamHI-W (internal repeat) of the EBV genome were used. EBV mRNA was detected in neoplastic cells in 16 of 54 (30%) lymph node biopsy specimens from usual subtypes of HD (lymphocyte predominance, 0/5; nodular sclerosis, 4/22; mixed cellularity, 12/26; unclassified, 0/1). EBV mRNA was also detected in the lymph node biopsy of 1 additional human immunodeficiency virus (HIV)-related case of HD (mixed cellularity) and in 2 of 4 cases of B-cell lymphomas occurring in patients with acquired immunodeficiency syndrome (AIDS). In other non-Hodgkin's lymphomas, EBV mRNA was detected in only 1 of 41 cases. Cases of HD positive for EBV mRNA were immunostained by CD30 and CD15 antibodies. The hybridization signals were exclusively restricted to Reed-Sternberg cells and variants. When analyzed retrospectively, no statistically significant correlation emerged between hybridization findings, EBV serology, or disease outcome over the 3 years of the availability of ModAMeX technique. The findings support the contention of a direct role of EBV in the pathogenesis of HD, at least in some cases.

Adult↗
PubMed1991

Identification of a novel EBV-induced membrane glycoprotein of 43 kDa with H667 MAb.

Using purified B95-8 Epstein-Barr virus (EBV), a MAb designated H667 was produced. We demonstrated by indirect membrane immunofluorescence (IF) on six EBV producer cell lines and by immunoelectron microscopy that H667 reacted with a membrane antigen. H667 recognized a 43-kDa EBV protein (p43) as determined by immunoblotting using purified EBV from the six producer cell lines. Phosphonoacetic acid treatment of B95-8 cells was associated with the disappearance of p43, indicating that it was a late antigen. This antigen was shown to be a glycoprotein by incorporation of [14C]glucosamine and was shown to contain an N-asparagine-linked glycosyl group by its sensitivity to tunicamycin. It was named gp43. The H667 MAb inhibited B95-8 EBV cord blood lymphocyte transformation only when a low inoculum was used but failed to inhibit EA induction in Raji cells by P3HR1 EBV. Human sera reactivity against the gp43 antigen was studied. By the immunoblotting method, using H667 immunoaffinity chromatography-purified gp43, we showed that 70.9% of the human sera tested had antibodies directed against gp43. By IF blocking tests, we found that only 12.5% of the sera tested were reactive, indicating that the epitope corresponding to the H667 MAb was not the most immunogenic gp43 epitope.

Animals↗
PubMed1991

[Maternofetal infection with human parvovirus B19. Apropos of 2 cases].

Two cases of maternal-fetal human parvovirus B19 infection are reported. The first case involved a feto-placental anasarca occurring during the third trimester and complicated by in-utero death with expulsion of a fetus with multiple malformations. The second case involved meconial peritonitis during the second trimester with favourable outcome after cesarean section and resolution of the digestive syndrome. Proof of PV B19 infection was obtained by identifying M specific immunoglobulins and viral DNA. After a review of the clinical situations most often encountered and the particular features of these two cases, therapeutic attitudes are proposed for this infection of major gravity during pregnancy.

Adult↗
PubMed1989

Production of anti-B monoclonal antibodies (DBB.42, DBA.44, DNA.7, and DND.53) reactive on paraffin-embedded tissues with a new B-lymphoma cell line grafted into athymic nude mice.

A new B-lymphoma cell line (DEAU-cell line) was established from a diffuse large-cell lymphoma (centroblastic type) and was successfully grafted in athymic nude mice. Monoclonal antibodies (MoAbs) were generated using splenocytes of DEAU-tumor bearing mice. Before the fusion experiments, cellular immunity of the mice bearing growing DEAU tumors was restored by injection of spleen cells from conventional Balb/C mice. Spleen cells from conventional Balb/C mice immunized with DEAU-cell line were also used for the generation of MoAbs. Four MoAbs (DBB.42 and DBA.44 from normal Balb/C mice, and DNA.7 and DND.53 from athymic nude mice) were investigated because they identified B-cell-associated antigens not destroyed by fixatives. DBB.42 recognized a pan-B cell-associated antigen (molecular weight (mol wt) = 45 Kd). DBA.44 detected a B-cell antigen (mol wt not determined) expressed on a subpopulation of B lymphocytes in the mantle zone of lymphoid follicles. DNA.7 also defined a B-cell antigen (43 Kd) mainly expressed on germinal center cells. Similarly, DND.53 recognized a B-cell antigen (two bands of mol wt 20 Kd and 35 Kd, respectively) mainly expressed on germinal center cells and mantle zone lymphocytes and interdigitating reticulum cells in the paracortical area. Major differences were found in the reactivities of these MoAbs on malignant lymphomas. DBB.42 was positive with almost all B-cell lymphomas and some T-cell lymphomas. Within the group of low-grade B-cell lymphomas, DBA.44 reacted principally with hairy-cell leukemia. DNA.7 reacted mainly with high-grade B-cell lymphomas with a weak positivity in low-grade B-cell lymphomas. DND.53 reacted with all but one B-cell lymphoma, cells of histiocytosis X, and Reed-Sternberg cells. These findings indicate that new MoAbs can be generated by using spleen cells from athymic mice bearing human tumors as well as by new lymphoid cell lines. The MoAbs so generated, as in the present study, are deemed potentially useful for the recognition of B-cell lymphomas in routine diagnostic histopathology. In addition, DND.53 could be of value for the diagnosis of histiocytosis X and the detection of Reed-Sternberg cells in Hodgkin's disease.

Animals↗
PubMed1989

[Severe Epstein-Barr virus infection in an infant].

A 11 month-old boy, without any informative familial pedigree, was admitted for peritonitis after intestinal perforation, associated with signs of pseudolymphoma and histiocytic activation. He developed later unexplained gastrointestinal bleeding and interstitial pneumonitis, which spontaneously improved. All infectious and immunologic studies were negative. Epstein-Barr Virus was found in throat, lungs and blood, whereas the specific antibodies production was delayed. No abnormality was detected 18 months later, except for a disappearance of vaccinal antibodies.

Humans↗
PubMed1987

Biochemical and ultrastructural findings in Epstein-Barr virus-transformed lymphoid cell lines from type 1 Gaucher disease.

Lymphoid cell lines established by Epstein-Barr Virus (EBV)-transformation of peripheral blood B-lymphocytes from patients affected with type 1 Gaucher disease showed a severe deficiency of glucosylceramide-beta-glucosidase activity (residual activity around 15%-30% of control activity). Ultrastructural investigations showed, in these lymphoid cell lines from type 1 Gaucher disease, the presence of numerous membrane-bound inclusion bodies characteristic of Gaucher cells.

Adult↗
PubMed1987

[Virus diseases and cancer of the vulva].

The study of cancers of the vulva, first of all, attempts to classify precancerous lesions of the external genital apparatus. The proceedings of the ISSVD were carried out here in 1975. Clinical, epidemiological and viral arguments of HPV and HSV have been considered in order to demonstrate their responsibility in neoplasms of the vulva. However, HPV seems the main cocarcinogen. Cancers of the vulva appear, therefore, as a true sexually transmitted disease and the authors emphasize a simultaneous monitoring of the cervix and the male genital apparatus.

Adult↗
PubMed1986

Epstein-Barr virus serology in bone marrow transplantations: a one-year retrospective study with detection of EBV IgM-VCA-specific antibodies.

The specific antibody response to Epstein-Barr virus (EBV) antigens of 41 bone marrow transplant recipients with leukemia or aplastic anemia was examined retrospectively by immunofluorescence test (IF) over 1 year. We observed high titers (greater than 640) of IgG-viral capsid antigen (VCA) with emergence of IgG-early antigen (EA) and frequent absence or low levels of Epstein-Barr nuclear antigen (EBNA) antibodies. After absorption to remove rheumatoid factor (RF), five of the 41 recipients had IgM-VCA antibody to EBV, which appeared between weeks 26 and 48 after BMT and persisted for 1-4 months. No heterophil antibodies were detected in these sera, and none of the five recipients had a history of infectious mononucleosis.

Adolescent↗
PubMed1983

Molecular forms of beta-N-acetylhexosaminidase in Epstein-Barr virus-transformed lymphoid cell lines from normal subjects and patients with Tay-Sachs disease.

In whole leukocytes and in lymphocytes from normal subjects, the percentage activity of heat-stable beta-N-acetylhexosaminidase (30 +/- 5% and 45 +/- 5%, respectively) was higher than in the transformed lymphoid cell line (19 +/- 3%). In Tay-Sachs transformed cells as well as non-transformed beta-N-acetylhexosaminidase was almost completely heat-stable (95 - 98%). In the transformed cells from normal subjects, the beta-N-acetylhexosaminidase B (Hex B) activity (5% of total) was significantly lower than in blood lymphocytes (average 25 - 30% of total activity), whereas Hex A and Hex I were similar in the either cell type. Blood lymphocytes and lymphoid cell lines established from a Tay-Sachs patient lacked heat-labile Hex A and expressed high heat-stable Hex I and Hex B activities (3-6-fold). After neuraminidase treatment, Hex A peak sharpened while Hex I peaks switched to higher pI than normal Hex I, in the region of Hex B. PreHex A/S pI was not affected. Hydrolytic properties using the both substrates (4-methylumbelliferyl-2-acetamido-2-deoxy-beta-D-glucopyranoside and 4-methylumbelliferyl-2-acetamido-2-deoxy-beta-D-galactopyranoside) of each molecular form were similar in transformed and non-transformed cells. Data derived from the use of a mixture of substrates were consistent with the model which proposes a common active site for either substrate in the case of preHex A, Hex B and Hex I, but not for Hex A. Thus Epstein-Barr virus-transformed lymphoid cell lines represent an accurate model system for studies on Tay-Sachs disease.

Cell Line↗
PubMed1982

[Histopathologic, ultrastructural, immunologic and virologic study of Gibert's pityriasis rosea].

A complete study of pityriasis rosea (Gibert) has been performed; this study includes: --a pathological and ultrastructural examination of the skin biopsies; --an immunological study: direct and indirect immunofluorescence (seric anti-cutaneous antibodies); --a virological investigation: ultrastructural examination of the specimens, inoculation of homogenized-skin specimens to 3 cellular cultures; --serological investigations for influenza A, B, parainfluenza 1, 2, 3, adenovirus, respiratory syncitial virus, Mycoplasma pneumoniae, ornithosis-psittacosis, Q-fever, herpes-virus, herpes-virus varicellae, cytomegalovirus, Epstein-Barr virus. All viral investigations had a negative result. Virus or virus-like particle has were not detected on the ultrastructural examinations. A viral infective agent cannot be incriminated as the cause of PRG. However, a large number of PRG patients had antibodies for the Epstein-Barr virus early antigen. The authors are carrying on with this particular investigation.

Adolescent↗