Cytotoxicity, blood compatibility and antimicrobial activity of two cyanoacrylate glues for surgical use.

The biocompatibility of two cyanoacrylate surgical glues (Glubran and Glubran 2), supplied by General Enterprise Marketing, Viareggio, Lucca, Italy, was tested through cytotoxicity and blood compatibility tests and the evaluation of antimicrobial activity. Cytotoxicity and blood compatibility tests were performed on the polymerized glues. Using the neutral red uptake test, the extracts from Glubran and Glubran 2 after polymerization were non-toxic to L929 cells only when diluted 1: 10 with culture medium. Glubran and Glubran 2 induced a significant decrease of activated partial thromboplastin time (APTT), which is favourable with regard to the desired haemostasis. The APTT shortening determines a haemostatic effect and therefore contribute to the tissue adhesion induced by the glues. Otherwise, no significant variation of prothrombin activity, fibrinogen, platelet number, total and differential leukocyte count was induced by the glues, which, in addition, did not show haemolytic effect. There was no difference between Glubran and Glubran 2 regarding haemocompatibility. The antimicrobial ability of the unpolymerized glues was tested onto Bacillus subtilis var. niger for 3 weeks: neither Glubran nor Glubran 2 were found effective in this respect. In conclusion, we can assume that cytotoxicity was severe with the undiluted glues, but was acceptable when glues were diluted. On the contrary, blood compatibility was acceptable for the intended use of the glues. No difference was found between Glubran and Glubran 2 after polymerization.

Human herpesvirus-6 reactivation in a longitudinal study of two HIV-1 infected patients.

After primary infection, human herpesvirus-6 (HHV-6) persists in latent form and can be reactivated in immunocompromised subjects. A longitudinal study of HHV-6 infection was carried out in two HIV-1 seropositive patients to provide in vivo evidence of HHV-6 reactivation. Concomitant with a significant rise of anti-HHV-6 IgG detected by IFA, a transient increase of HHV-6 viral load was shown in PBLs by PCR. During HHV-6 reactivation it was also identified either cell-free HHV-6 by PCR in plasma or IgM antibody titers. HHV-6 reactivation was followed by a temporary decrease in CD4+ count and by a progressive dramatic loss of CD4+ during the following 18 months. HHV-6 strain characterization by PCR demonstrated that first patient (MM) initially showed the B variant, followed by reactivation and persistence of the A variant, while in the second (SG) only the A variant was detected. The evidence of HHV-6 reactivation suggests its involvement in immunologic damage underlying the disease.

Lymphotropic virus infection of peripheral blood mononuclear cells in B-cell non-Hodgkin's lymphoma.

Some lymphotropic viruses such as Epstein-Barr virus (EBV) and human herpesvirus 6 (HHV-6) have been proposed as causative agents of B cell non-Hodgkin's lymphoma (NHL). More recently, the presence of hepatitis C virus (HCV), which is both a hepatotropic and lymphotropic virus, has been reported in one third of B cell NHL patients. The aim of this study was to investigate in a series of B cell NHL the prevalence of three lymphotropic viruses, i.e. EBV, HHV-6 and HCV, in peripheral blood mononuclear cells (PBMC). Eighteen unselected B cell NHL patients (10 men, 8 women; mean age 62 +/- 12 years, range 31-77 years; mean disease duration 1.8 +/- 1.4 years) and 40 age- and sex-matched healthy controls were included in the study. In all cases, an acquired-immunodeficiency-syndrome-related lymphoma was excluded. By means of the polymerase chain reaction technique, EBV DNA, HHV-6 DNA and HCV RNA were detected in PBMC. HCV genomic sequences were significantly more frequent in PBMC of NHL patients than in controls (33 vs. 2.5%; p < 0.01); on the other hand, in the same two groups EBV DNA (39 vs. 60%; p = not significant) and HHV-6 DNA (22 vs. 32%; p = not significant) were present in a comparable percentage of individuals in the same two groups. The infection of PBMC by HCV alone was present in the majority (5 of 6) of HCV-positive NHL. These data support the implication of HCV infection in a statistically significant number of B cell NHL, whereas a possible co-operation between HCV and other well-known lymphotropic viruses seems to be excluded.

Presence of HIV-1 proviral sequences in saliva of infected individuals in relation with clinical stage and CD4+ lymphocyte count.

We detected by PCR (Polymerase Chain Reaction) HIV-1 proviral sequences in saliva cells of 89 HIV+ subjects at different stages of disease. Twenty negative individuals not at risk of HIV infection were considered as controls. The amplification of DNA was performed using the primers of genomic env region SK68 and SK69. The presence of HIV-1 in DNA was found in 16/89 (18.0%) saliva samples from HIV-1 subjects but in none of the 20 saliva samples from healthy subjects. No statistically significant difference in the presence of HIV-1 proviral sequences in saliva was observed when comparing patients receiving AZT or no treatment and patients at different stages of infection. Conversely, a statistically significant difference among subjects with CD4+ cell counts > 400/cmm and those with CD4+ cell counts from 200 to 400/cmm, was found stratifying the subjects according to their CD4+ cell counts.