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P Verani

Publications and source records attributed to P Verani.

At least 73 records · Page 4Linked to original sources
PubMed1988

HIV, HTLV-1, and HBV infections in a cohort of Italian intravenous drug abusers: analysis of risk factors.

A seroepidemiological survey of a group of 291 intravenous drug abusers (IVDAs), 45 household contacts of IVDAs, and 39 laboratory workers has been carried out to determine the prevalence of HIV-1, HIV-2, HTLV-1, and HBV antibodies in the sera, as well as to evaluate the role of various risk factors. Among i.v. drug abusers, the prevalence was 32.3% for HIV-1 and 6.6% for HTLV-1. For both viruses, the total figures did not significantly change from 1985 through 1987, accounting for a slow viral circulation in this group. No seropositivity (HIV-1, HTLV-1) was found among laboratory workers, whereas one subject was found seropositive for HIV-1 among household contacts. From 1985 to 1986, 5 out of 58 subjects seronegative for HIV-1 and 5 out of 82 seronegative for HTLV-1 seroconverted (incidence rates of 8.6 and 6.1%, respectively). From 1986 to 1987, none out of 11 seronegatives for HIV and 1 out of 16 seronegatives for HTLV-1 seroconverted. The total figures for hepatitis B markers were 79.2% among IVDAs, 24.4% among household contacts, and 25.6% among laboratory workers. A significant correlation was found between presence of HBV markers and seropositivity for HIV and HTLV-1. A significant association with HIV-1 seropositivity was found for history of sexual intercourse with HIV-1 seropositive partners and for sexual promiscuity. These data emphasize the important role played by sexual behavior in addition to needle-sharing in the spreading of multiple infections among drug abusers.

Female↗
PubMed1987

HIV env glycoprotein shares a cross-reacting epitope with a surface protein present on activated human monocytes and involved in antigen presentation.

A serological cross-reactivity between env gp120 glycoprotein of the human immunodeficiency virus (HIV) and a human cellular surface protein has been defined by a monoclonal antibody (M38) raised against HIV. The cellular antigen is a protein of ca. 80 kDa expressed on a small fraction of mononuclear cells in peripheral blood and in lymph nodes. The protein behaves as an activation antigen of the monocytic lineage since it is expressed by monocytes in plastic-adherent culture conditions and by interferon-gamma-treated monocytes and pro-monocytic U937 cells. The protein is involved in antigen presentation since the antibody efficiently inhibits the proliferation of responsive lymphocytes in autologous tetanus toxoid presentation assays. In the T lymphoblastoid line H9, the protein is present in very small amounts, is not induced by interferon-gamma and increases after HIV infection. Sera from lymphoadenopathy syndrome and acquired immunodeficiency syndrome (AIDS) patients fail to detect the cellular protein, although containing antibodies reacting with gp120. We propose that both viral and cellular structures recognized by the monoclonal antibody (mAb) are involved in interactions with CD4 molecules of T helper lymphocytes and that such molecular mimicry might be relevant in the pathology of HIV infection. This view is supported by the finding that BL/10T4, a CD4-specific mAb, binds to M38 neutralizing its interactions with HIV and with monocytes. mAb M38 thus behaves as the internal image of CD4. This single property would explain all its diverse binding characteristics.

Antibodies, Monoclonal↗
PubMed1987

In situ hybridization of human immunodeficiency virus (HTLV-III) in cryostat sections of lymph nodes of lymphadenopathy syndrome patients.

The presence of human immunodeficiency virus (HIV, or HTLV-III) genome sequence was investigated by means of in situ hybridization in cryostat sections of lymph nodes from lymphadenopathy syndrome (LAS) patients. The technique employed involved the modification of the DNA probe by chemical insertion of an antigenic sulfone group in cytosine moieties and the visualization of DNA by a double-antibody immunohistochemical reaction. The hybrid formation was revealed in five out of ten cases: in all positive samples, HIV was mainly observed in the cytoplasm of lymph node cells. The method of in situ hybridization described in the present paper is specific and has some advantages if compared with other techniques based on the use of DNA probes labelled with radioisotopes or biotin by nick translation.

AIDS-Related Complex↗
PubMed1987

Time-resolved immunofluorescence: a sensitive and specific assay for anti-HIV antibody detection in human sera.

We describe a new immunoassay, time-resolved fluoroimmunoassay (TR-FIA), for detection of anti-HIV antibodies in human sera. This method is based on the use of a crude virus preparation coated on a polystyrene microtitre plate and of a swine anti-human IgG labelled with a rare earth metal, europium, as fluorescent label chelated with EDTA derivatives. A light pulse from a xenon lamp (340 nm) was used to excite the label and after a 400 microseconds delay time the emission fluorescence was counted for 400 microseconds at 613 nm. This cycle was repeated 1000 times during the total counting time of 1 s. TR-FIA presents considerable advantages over other techniques: (a) it avoids time-consuming, expensive and hazardous virus purification steps; (b) it excludes the use of radiotracers or substrates with potential health risks to reveal the reaction; (c) it has high sensitivity and specificity. A total of 475 serum specimens were tested by ELISA and by TR-FIA. The proportions of positivity were 29.6% by ELISA versus 26.7% by TR-FIA. The sensitivity of both systems was 100%. The specificity was 87.5% for ELISA, whereas it reached a value of 99.4% for immunofluorimetric assay.

Antibodies, Viral↗
PubMed1987

Recovery of HIV-related retroviruses from Italian patients with AIDS or AIDS-related complex and from asymptomatic at-risk individuals.

Human retroviruses have been detected in supernatants of cultures of Ficoll-enriched lymphocytes from peripheral blood, lymph nodes and bone marrow of (a) 32 out of 42 patients with Acquired Immunodeficiency Syndrome (AIDS), (b) 34 out of 64 patients with AIDS-related Complex (ARC), (c) 9 out of 18 asymptomatic children born from Human Immunodeficiency Virus (HIV) seropositive mothers, and (d) 9 out of 28 asymptomatic drug abusers or hemophiliacs. Virus detection was monitored by assaying culture supernatants for the presence of Mg++-dependent reverse transcriptase (R.T.) activity. A number of these virus-positive sups were passaged repeatedly in cultures of phytohemagglutinin-stimulated and Interleukin-2 (IL-2) treated fresh lymphocytes from healthy blood donors. Occasionally, multiple samples were obtained at varying time intervals from the same patient and consistently yielded detectable retroviral activity. Several isolates were characterized as closely related if not identical to HIV, HTLV-IIIB strain, since cells from either patients' own lymphocyte cultures or subcultures infected with passaged virus were stained in an indirect immunofluorescent assay with both patients sera and monoclonal antibody against p24 antigen of the HTLV-IIIB strain. Representative isolates, grown on fresh lymphocytes of healthy donors and metabolically labelled with 35S-cysteine, were also analyzed in a radioimmunoprecipitation assay (RIPA) against patients' sera to define their antigenic pattern, which was widely superimposable to that obtained with HTLV-IIIB-infected H9 cells. DNA from lymphocytes infected with 2 representative isolates were Southern-blotted and probed with an insert from a plasmid containing the entire genome of the HTLV-IIIB strain. The hybridization patterns were comparable with those obtained with DNA from H9-infected cells.

AIDS-Related Complex↗
PubMed1986

Prevalence of HTLV-III/LAV antibodies in Italian asymptomatic hemophiliacs given commercial concentrates of factors VIII and IX.

The prevalence of HTLV-III/LAV antibodies was evaluated in 222 Italian asymptomatic hemophiliacs treated exclusively with commercial factor concentrates made with American plasma. An increase of HTLV-III/LAV seropositivity from 1983 to 1985 was evident. This was independent of the type of hemophilia (A or B) but directly correlated to the amount of concentrate administered in the previous year. Immunological data (T4 and T8 lymphocyte subsets) were evaluated in relation to seropositivity to HTLV-III/LAV. The presence of antibodies was found to be significantly associated with a low T4/T8 ratio and to a reduced T4 subpopulation, whereas increased levels of T8 lymphocytes correlated weakly with seropositivity. Data from 47 hemophiliacs tested both in 1984 and 1985 showed that 100% of those negative in 1984 and highly transfused in the previous year seroconverted up to 1985, whereas 33% of those not highly transfused did so.

Antibodies, Viral↗
PubMed1985

Growth of the Phlebovirus Toscana in a mosquito (Aedes pseudoscutellaris) cell line (AP-61): establishment of a persistent infection.

Toscana Virus, a sandfly-associated Phlebovirus, was adapted to grow in cultured Aedes pseudoscutellaris (AP-61) mosquito cell line. No evidence of virus growth was seen after primary infection of cell monolayers under maintenance conditions. On the contrary, persistent infections were established by subculturing infected cultures. Cytopathic effect was never observed. Significant titres of virus (10(3)-10(5) PFU/ml), as assayed in Vero cells at 37 degrees C, were released from persistent infected cells after several subcultures at 29 degrees C over a period of six months. The percentage of virus-producing cells in the persistently infected cultures varied from 0.003 to to 0.017 per cent, whereas from 10 to 50 per cent of cells were shown to retain viral antigens by immunofluorescence. The virus released from persistently infected cultures did not show changes in both plaque size and temperature sensitivity from the parental virus. The virus released from persistently infected cultures multiplied in AP-61 cell monolayers reaching relatively high titres (10(4) PFU/ml).

Aedes↗
PubMed1985

Growth of two phleboviruses after experimental infection of their suspected sand fly vector, Phlebotomus perniciosus (Diptera: Psychodidae).

Phlebotomus perniciosus were infected by intrathoracic inoculation and membrane feeding techniques with two phleboviruses (Toscana and Arbia) isolated in Italy from this sand fly species. Low levels of multiplication of both viruses were detected after intrathoracic inoculation of the sand flies. Only some insects were found infected after oral ingestion of the two viruses. The percentage of flies infected orally was related to the amount of virus ingested. Toscana virus was transovarially transmitted to two larvae of the F1 progeny of orally infected sand flies. No signs of infection were observed after oral infection when unnatural virus-vector combinations were tested, e.g., Toscana virus-P. papatasi or Naples sand fly fever virus-P. perniciosus. The virus concentrations recorded in P. perniciosus experimentally infected with both Toscana and Arbia viruses were similar to those found in naturally-infected sand flies.

Bunyaviridae↗
PubMed1984

Establishment and maintenance of persistent infection by the Phlebovirus Toscana in Vero cells.

Persistent infections were established by serial undiluted passages of the Toscana virus of the genus Phlebovirus in Vero cells. Persistence was maintained through more than 70 passages over a period of 2 years. The persistently infected cells were morphologically similar to the parental Vero cells and released variable amounts of infectious virus. A small percentage of the persistently infected cells produced infectious virus while a larger percentage was shown to possess viral antigens by fluorescent antibody staining. Temperature sensitivity and host cell interferon production were not involved in establishment or maintenance of persistence. The persistently infected cultures were resistant to superinfection with homologous Toscana virus, but they were susceptible to superinfection with heterologous viruses of different genera or families. Toscana virus persistently infected cells showed a selective graded resistance to the replication of other Phleboviruses. Additionally, the virus from persistently infected cells interfered with the replication of standard Toscana virus when they co-infected normal cells. The characteristics of the persistently infected cultures are compatible with some of the characteristics described for the persistence mediated by defective-interfering particles of other viruses.

Animals↗