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The euploid-diploid cell line CE, issuing spontaneously from a normal human bone marrow culture, displays B-cell differentiation and activation markers and is positive (> or = 90% of cells) for Epstein-Barr nuclear antigens. CE suspensions were inoculated with serum from a patient chronically infected with hepatitis C virus (HCV). After inoculation, the cells were regularly subcultured with a split ratio of 1:2 every 4-6 days. RNA extracted as late as 65 days after infection from the inoculated cells were positive by polymerase chain reaction for the 5' untranslated region of the HCV genome, and viral antigens were detected by immunofluorescence. Virus was also released from the infected cells into the medium. Intracellular HCV could be successfully passaged twice in CE cultures. On the basis of these findings, the CE cell line appears promising as a model for studying HCV replication and persistent infection in vitro.

Equilibrium pool scintigraphy was performed in 11 obese subjects (BMI 34 +/- 2) and in 14 normal control subjects. Temporal and spatial smoothing of the data was then performed followed by time-activity curve generation using a semiautomatic second derivative edge-detection algorithm. The increase in counts during the first third of diastole divided by the total change in number of counts during diastole was determined as the one-third filling fraction. This index of diastolic filling was significantly decreased in obese subjects as compared to the control group. These findings indicate that diastolic abnormalities may be an early finding in obesity-linked heart disease, occurring in the presence of normal systolic function (E.F. = 65 +/- 5%).

FcRs (Fc Receptors) have been detected on the cell surface of two human neuroblastoma cell lines; IMR 32 and SK-N-SH, by immunocytochemistry and flow cytometric analysis, using a previously characterized polyclonal antiserum raised against the Fc gamma R isolated from a human CLL line (Gorini, Medgyesi, Garavini, Dorrington and Down, 1987; Rozsnay, Sarmay, Szabo, Medgyesi, Gorini and Gergely, 1990). FcR is expressed on all the cells of both lines at least at the same level as on the HL60 promyelocyte cell line used as positive control. Two electrophoretic components displaying apparent molecular masses of 70 and 43 kDa respectively have been identified by SDS-PAGE followed by Western blotting analysis of crude cell membranes. In addition, "in situ" hybridization experiments seem to exclude a correlation between FcR expression and N-myc oncogene activity. The presence of FcR in neuroblastoma could be related to a possible functional role even on these cells which do not belong to the immune system; moreover, they could also be exploited for a diagnostic characterization of this tumor.

Sixty-six patients suffering from suspected chlamydial conjunctivitis or keratoconjunctivitis underwent direct examination and culture procedures on specimens from conjunctival swabs and corneal scraping for detection of Chlamydia trachomatis. Patient blood samples were also screened for the presence of antichlamydia IgG and IgA antibodies. Eye positivity was found in 12 and 15% of patients by using culture isolation and direct examination, respectively. In 3 out of the 8 patients with culture-proven chlamydial eye infection, all of them female, C. trachomatis was also isolated from the genital tract.

One hundred and one women suffering from "sine causa" recurrent abortion were screened for Chlamydia trachomatis (C.T.) infection by using direct examination, cultural and serological procedures. In this series, C.T. infection did not appear to be related to increased risk of recurrent abortion. The culture-positive and serology-positive rates (14.85% and 34.65%, respectively) did not differ from other unselected populations. Neither time from last abortion nor type of abortion were significantly related to C.T. infection. Nonetheless, the women who underwent examination within one year from last abortion and had a culture-positive partner as well, were more likely to present with a C.T.-positive culture.

A polyclonal rabbit antibody raised against an Fc receptor (FcR)-like membrane glycoprotein fraction of chronic leukaemic lymphocytes has previously been prepared and partially characterized. This antibody, called AbA, was found to precipitate a 70-kDa and a 45-kDa fraction of the detergent lysate of U937 cells and to inhibit ligand binding to Fc gamma R on the P388D1 murine macrophage cell line. In the present work we have characterised this antibody further. All Fc gamma RII-positive B lymphoblastoid cell lines, as well as resting human B lymphocytes, were positively stained with the AbA antibody. U937 cells were found to be negative, but after stimulation with phorbol ester (PMA), 50% of the cells became positive. AbA antibody did not react with human T cell lines or with the T + 0 cell subset of peripheral blood. Monocytes were also negative. On the other hand, AbA antibody exhibited a dose-dependent inhibition of antibody-mediated cytotoxic reaction (ADCC) of monocytes, while not affecting K cell-mediated ADCC. It had an inhibitory effect of EA rosette formation of B cells and stimulated U937 cells. Furthermore, it interacted with the soluble form of Fc gamma RII released by activated B lymphocytes, and--similarly to IgG--precipitated a 33 kDa fraction from the supernatant of B cells.

In recent years Chlamydia trachomatis has emerged as a significant cause of acute salpingitis and reproductory failure. In this study, 85 women suffering from primary infertility and 85 parous women as control group were screened for C. trachomatis genital infection by means of cell culture and antigen detection on genital samples as well as the detection of anti-chlamydial antibodies in blood. C. trachomatis was detected in 31.8% of infertile women and 5.8% of fertile subjects. Isolation of C. trachomatis in cell culture proved to be the most reliable diagnostic tool when compared to immunofluorescence staining on smears and serology. Although the latter may be considered of great value in epidemiological researches, culture isolation should be associated for the diagnosis of active infection.

A human Toxoplasma strain, isolated in mice from bioptic lymphoglandular tissue, has been cultured in vitro in continuous cell lines. Its presence in some parastized cells, with parasitophorous vacuoles surrounded by a cyst-like wall and filled with a cystozoite-like clone, was observed by electron microscopy. These characteristic and constant features were confined in different cell line cultures and are suggested as possible markers of low virulent strains.

The use of a gel filtration method allowed us to obtain pure IgM fractions to be tested for specific Toxoplasma serology. The good correlation found in our series between IgM-IFAT and LBCF-H100-TTE performed on pure IgM fractions suggests that LBCF-H100-TTE may be another useful serological test for detection of IgM antibodies although false negative results might occur when LBCF-H100-TTE is performed on IgM fractions of cord sera.

Mice exposed to a sublethal dose of X-rays were immunized with alum-precipitated DNP-KLH (dinitrophenyl-keyhole limpet haemocyanin) and B. pertussis either before or after irradiation. The primary anti-DNP antibody response was evaluated during 8 weeks after immunization by the equilibrium dialysis technique using ammonium sulphate- precipitated serum globulins and the ligand 3H-labelled xi-DNP-L-Lysine. The serum concentrations of antibody sites in mice immunized 1-5 days before or 2 h-8 weeks after 450 rad were below the values in unirradiated controls at all bleeding times. Antibody affinity, however, was found to be up to 20 fold higher in irradiated mice than in control mice when antigen was injected before, or 3-8 weeks after, irradiation. Spleen cells from mice exposed to 450 rad 1-9 weeks before killing were stimulated in vitro with PHA, ConA, or LPS. Recovery profiles of mitotic responsiveness suggest that enhancement of antibody affinity in irradiated mice could result from relative lack of suppressor T Cells.

Long-term syngeneic radiation chimeras displayed a very low incidence of reticulum cell sarcoma as compared with control mice. Immune reactivity of these animals was studied in vivo by anti-dinitrophenyl antibody titer and affinity and in vitro by mitotic responsiveness to phytohemagglutinin, concanavalin A and lipopolysaccharide. Anti-body titer and affinity as well as the response to T lectins were found to be increased in chimeras. These results were attributed to increased function of mature T2 cells, which could explain the reduced incidence of reticulum cell sarcoma in chimeras.

The AA. analyze the ultrastructural and immunological patterns of a low virulent strain of T. gondii cultured in vitro on A-9 cells line (PV-H1C-83). The tissue culture method described here is highly recommended to study the immunological aspects of experimental toxoplasmosis. Biological tests' results and the time courses of serological tests are also similar to those obtained from mice infected with cerebral tissue containing cysts. The low virulent strain (PV-H1C-83), when cultured in vitro, is able to induce the formation of large parasitophorous vacuoles, in which the EM investigation shows a typical cyst wall enveloping numerous bradyzoites.

The aggregation and condensation of ribosomes and the disjunction of the cell-wall membranous system are the ultrastructural alterations caused by rifampicin on B. melitensis cultured in Brucella-Broth medium. Our ultrastructural researches carried out on mouse peritoneal macrophages infected with B. melitensis and treated with rifampicin (1 microgram/ml) have demonstrated that vacuoles containing B. melitensis which had been damaged by the drug fuse with lysosomes. On the contrary vacuoles containing undamaged and viable Brucellae showed markedly impaired lysosomal fusion.

Sublethally irradiated mice primed with dinitrophenyl (Dnp)-keyhole limpet hemocyanin immediately after irradiation or 30 days later and subsequently boosted with a second injection of antigen displayed a secondary response to Dnp characterized by antibody affinity greater than that in unirradiated controls. Also, in radiation chimeras primed with Dnp-keyhole limpet hemocyanin 120 days after syngeneic or allogeneic bone marrow transplantation the antibodies against Dnp produced after boosting were of higher affinity than the antibodies raised in normal mice. These findings are tentatively attributed to lack of suppressor thymus-derived lymphocytes (T cells) in sublethally irradiated mice and bone marrow chimeras, in which the enhanced ability to produce antibodies of high affinity may compensate for quantitative defects of the immune system.

A preliminary research, in order to evaluate by immunofluorescent technique the prevalence of heart specific and non specific autoantibodies, has been performed on a population of 58 cardiac patients, allograft applying. Two other populations (cardiac patients not allograft candidates, and healthy blood donors), were also tested as controls. Significant differences in the presence of specific anti-heart antibodies were revealed among the three populations (89.7, 39.1 and 10%, respectively). No relevant correlation has appeared with the antibody titer between the two groups of cardiac patients.

Leptospirosis, anthropo-zoonosis ubiquitously widespread, is a social and economic problem still to be solved. The experimental and therapeutic employment of many antibiotics has largely been tested "in vitro" and "in vivo". In the following research we tried to evaluate, by experimental "in vitro" method, the sensitivity difference of three serovar strains of Leptospira interrogans to two macrolides, Erythromycin and Josamycin, compared with Penicillin. From standard cultures, previously treated with serial dilution of these antibiotics, the MIC and MSC, as quantitative parameters, have been stated. For the qualitative evaluation of the damages induced at ultrastructural level by the drug activity. Electron Microscopy investigations were performed on specimens from cultures treated for 6 hr with twice and tenfold the MSC. The present research confirms the good sterilizing efficaciousness "in vitro" of the tested macrolides (MSC less than 1 mcg/ml) and their different activity pathway.

Two membrane glycoproteins that bound immune complexes and inhibited Fc-receptor- (FcR-)mediated functions in vitro were purified from human FcR+ chronic-lymphocytic-leukaemia cells. A multi-step purification was developed, consisting essentially in: (i) Tween 40 extraction of crude cell membranes; (ii) solubilization of membrane fragments by Renex-30; (iii) isolation of glycoproteins by affinity chromatography on Lens culinaris haemagglutinin-Sepharose; (iv) papain treatment of the eluted glycoproteins followed by gel-filtration chromatography; (v) purification by polyacrylamide-gel electrophoresis of two molecular species from the protein-size fraction enriched for immune-complex-binding activity. The two electrophoretically isolated components displayed apparent molecular masses of 70 and 45 kDa by SDS/polyacrylamide-gel electrophoresis and restricted charge heterogeneity by two-dimensional analysis. Two-dimensional peptide mapping revealed the presence of many peptides in common between the two proteins and the absence of a number of peptides in the 45 kDa component. These two polypeptides were used as immunogens to produce polyclonal antibodies that cross-reacted with both proteins and specifically inhibited FcR-mediated reactions in vitro. Furthermore, FcR-related components from detergent-extracted lysates of the human K562 and U937 cell lines or human placental membranes were revealed by the putative anti-FcR antibodies adsorbed on Protein A-Sepharose.