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Biomedical subjects

G Filice

Publications and source records attributed to G Filice.

At least 37 records · Page 2Linked to original sources
PubMed1999

Hepatocellular mitochondrial alterations in patients with chronic hepatitis C: ultrastructural and biochemical findings.

OBJECTIVE: Hepatitis C virus (HCV) infection is associated with increased lipoperoxidation, which may lead to interference with mitochondrial function with possible depletion of mitochondrial DNA (mtDNA). We correlated the ultrastructural findings of liver biopsy specimens with the lipoperoxidation markers and contents of mtDNA in chronic hepatitis C (CHC) patients with a different HCV genotype. METHODS: Liver biopsy samples obtained from 75 CHC patients were processed for histological and electron microscopic examination. Twenty-two subjects without known liver disease served as controls. Hepatic glutathione in its reduced (H-GSH) and oxidized (H-GSSG) forms were determined from biopsy specimens by high-performance liquid chromatography. Plasmatic and lymphocytic GSH and erythrocytic malonyldialdehyde (MDA) were also determined, along with the ratio between mtDNA and nuclear DNA (nDNA). RESULTS: Ultrastructural alterations of the mitochondria were documented in 23 patients with genotype 1b, compared with 15 patients with genotype 2a/2c (p = 0.020) and seven patients with genotype 3a (p < 0.001). A significant depletion of H-GSH and lymphocytic GSH, an increase of H-GSSG and MDA, and a reduction of the mtDNA/nDNA ratio were documented in patients with genotype 1b, compared with patients with genotype 2a/2c and 3a and with controls. CONCLUSIONS: In patients with genotype 1b frequent ultrastructural alterations of the mitochondria may be observed, and the depletion of mtDNA in these patients may represent the expression of a greater impairment of the process of oxidative phosphorylation. An increased production of free radicals in patients with genotype 1b may influence the evolution of the liver disease by enhancement of the cytopathic effect of HCV.

Adult↗
PubMed1997

Efficacy of a short-term amphotericin B + flucytosine combination therapy followed by itraconazole monotherapy in acute and chronic AIDS-associated cryptococcosis.

The authors report the clinical and microbiological findings of a 6-month follow-up of nine AIDS patients affected with cryptococcosis. Among these, seven patients suffered from meningoencephalitis and two from disseminated infection. The antifungal therapy during acute illness included the administration of amphotericin B at doses of 0.6 mg kg-1 day-1 i.v. plus flucytosine at doses of 100 mg kg-1 day-1 i.v. during the first 15 days followed by itraconazole at doses of 400 mg day-1 p.o. in the following 15 days. The maintenance treatment included itraconazole at doses of 200 mg day-1 p.o. indefinitely. During the 6-month follow-up, one patient died of hepatic failure related to C virus (HCV) hepatitis reactivation and another patient died of polymicrobial pneumonia. In two patients, the presence of multiple nodular lesions in the cerebral computerized tomography (CT) scan, related to cryptococcal granulomas, was associated with the persistance of fungi in the cerebrospinal fluid. In three patients with meningoencephalitis the three-drugs regimen was effective in eradicating the neurological infection, and relapses were not observed during the maintenance therapy with itraconazole during the 6-month follow-up. The two patients with haematogenous cryptococcosis did not relapse after the 6-month follow-up.

AIDS-Related Opportunistic Infections↗
PubMed1996

[New trends in the therapy of cryptococcosis in AIDS patients].

The Authors report the clinical and microbiological findings about a 6-months follow up of 9 AIDS-patients with Cryptococcosis. Among these, 7 patients suffered from meningo-encephalitis and 2 from haematogenous infection. The fungicidal treatment during acute illness, included the administration of Amphotericin B (0.6 mg/Kg/die i.v.) plus Flucytosine (100 mg/kg/die i.v.) during the first 15 days followed from itraconazole at doses of 400 mg/die in a single administration, during the following 15 days. The chronic suppressive therapy included itraconazole at doses of 200 mg/die p.o. indefinitely. During the 6-months follow up, one patient died of polymicrobial pneumonia and another of hepatic failure related to a reactivation of a previous HCV hepatitis. In 2 patients the presence of multiple nodular lesions in the cerebral CT scan, related to cryptococcal granulomas, was associated to a persistence of positive liquoral cultures and to a poor prognosis. In 3 patients with meningo-encephalitis, the three drugs regimen was quite effective in eradicating the neurological infection and no relapses were observed during the 6-months follow up. The 2 patients with hematogenous infection alone, didn't relapse during the 6-months follow up.

English Abstract↗
PubMed1995

HIV type 1 intraperitoneal infection of rabbits permits early detection of serum antibodies to Gag, Pol, and Env proteins, neutralizing antibodies, and proviral DNA from peripheral blood mononuclear cells.

The aim of this study is the development of an animal model useful for studying HIV-1 pathogenesis, candidate vaccines, and antiviral drugs. Aseptic thioglycolate peritonitis was induced in six rabbits. After 4 days, four rabbits were infected with 1 ml of HIV-1 stock containing 100 times the MID50. Blood samples were collected every 2 weeks for 8 months. Serum antibodies were tested by ELISA, using as antigen the recombinant protein p24; synthetic peptides of highly conserved regions of p31, gp41, and gp120; and a synthetic peptide of gp120 at the V3 loop region of HIV-1 strains IIIB and MN. Furthermore, neutralizing antibodies were tested by a microscale neutralization assay. Proviral DNA was detected by PCR, and virus isolation was performed by a cocultivation technique using primary rabbit peripheral blood mononuclear cells (PBMCs). All infected rabbits produced antibodies to HIV-1 proteins within 2 weeks and up to 8 months after virus infection. Serum antibodies were directed against the Env (gp120 and gp41), Gag (p24), and Pol (p31) proteins and against two synthetic peptides whose sequence corresponds to gp120 at the V3 loop region of HIV-1 strains IIIB and MN. Neutralizing antibodies were also detected in the sera of infected animals. Proviral DNA was detected in PBMCs by PCR within 4 weeks and up to 8 months after HIV-1 infection. HIV-1 was also isolated from PBMCs of infected animals at 30, 60, and 120 days after infection. Results obtained indicate that HIV-1 intraperitoneal infection of the rabbit permits the early detection of serum antibodies to Gag, Pol, and Env proteins, neutralizing antibodies, and proviral DNA sequences from PBMCs.

Animals↗
PubMed1993

Specificity and sensitivity of 3rd generation EIA for detection of HCV antibodies among intravenous drug-users.

Serum samples from 487 ambulatory I.V. drug users were screened for HIV and HCV antibodies to determine the prevalence of coinfection in this high risk group for AIDS. For anti-HCV antibody screening we first used a 3rd generation EIA using, as antigen synthetic peptides which were not subjected to false positive results due to antibodies against superoxide dismutase or against yeast proteins (which may copurify with the recombinant proteins employed in the first and second generation test). The specimens that were positive in the screening test were confirmed by a more specific EIA system that detect antibodies to proteins encoded by structural (HCV-st EIA) and non structural (HCV-nst-EIA) regions of the HCV genome. A second confirmation assay was also performed: sera were run in presence or absence of blocking reagents which inhibits antibodies to C200 and C22 HCV epitopes for binding to the solid phase. The sensitivity of the HCV EIA screening for human HCV antibody detection revealed a 100% positivity for HCV infection. The confirmatory strategy presented in this paper revealed an HCV EIA specificity of 98.6%. In this work we demonstrated a significantly higher prevalence (p < 0.001) of HCV exposure in HIV infected individuals compared to the general population. Our experimental data also confirmed that HBV infection in drug-users at high risk for HIV infection was significantly associated with HCV infection (p < 0.001). In contrast, the acquisition of HIV by sexual contact was not a statistically significant risk factor for HCV coinfection.

False Positive Reactions↗
PubMed1993

Booster PCR: evaluation of an improved method for amplification of a few HIV-1 proviral DNA sequences.

A biphasic polymerase chain reaction designed as booster PCR for the detection of human immunodeficiency virus type-1 (HIV-1) was evaluated in samples containing a very low number of target DNA. We examined DNA samples obtained from chronically infected H9/HTLV-III B cells and purified plasmidic DNA containing the entire HIV-1 genome. By using booster PCR we detected HIV-1 DNA sequences up to 5 infected cells in samples containing about 2 micrograms of genomic DNA, and up to 1 copy of plasmidic DNA in samples containing about 0.5 microgram of genomic DNA. Otherwise by using standard PCR HIV-DNA up 100 infected cells and up to 20 copies from plasmidic DNA could be detected. Our experiments in amplification of HIV-1 proviral DNA have demonstrated that booster PCR enhances sensitivity of detection of standard PCR in small quantities of target sequences at least 20-fold with no loss of specificity.

Cell Line↗
PubMed1992

Mice infection with HIV-1: a new mouse model for HIV-1 in vivo research.

In mice experimentally infected with 1 x 10(5) UI/mouse of HTLV-IIIB IgM antibodies were detected 10-12 days after the infection, reaching peak values two weeks later; the IgM seratiter progressively decreased thereafter and was negative at ten-eleven weeks. HIV p24 antigen was detected ten-fifteen days after infection and reached peak values five-six weeks later. Antigenemia subsequently decreased and showed an oscillating course with a progressive decrease which persisted throughout the observation period. Two weeks after infection we detected IgG antibodies to the major core protein p24; reactivity to gp41 was observed as early as reactivity to p24 and persisted throughout observation period. The IgG antibodies to all HIV epitopes peaked two-three weeks after infection; the time course showed a decrease after ten weeks, progressively decreasing thereafter. After sixty-five weeks of infection the IgG seratiter value was lower but remained positive. Viruses indistinguishable from HIV were isolated from the peripheral blood mononuclear cells of infected mice 30, 60, 180 days after infection. These seroimmunological and virological data confirm that the immunocompetent mouse may serve as a low-cost reproducible model for HIV-1 in vivo research.

Animals↗
PubMed1991

Endocytosis constitute the infectious route of HIV-1 entry in human and rabbit monocytes lacking the CD4 receptor.

To obtain "functionally" CD4 negative human monocytes (0-5 CD4 +/1 x 10(6)/cells), 50 ng/5.10(5) cells of OKT4A were added daily after a pre-incubation with OKT4A (100 ng/5.10(5) cells. In our experimental conditions the blocking the CD4 receptor of human monocytes with OKT4A monoclonal antibody did not prevent HIV-1 infection, although the level of virus replication appeared lower than that in cultures without OKT4A. "Naturally"CD4 negative rabbit monocytes infected with HIV-1 also released a detectable level of virus after 12-15 up 28-30 days. In "naturally" CD4 negative rabbit monocytes and "functionally" CD4 negative human monocytes, the virus particles entering via phagocytosis are not infectious because multiple well defined virions were observed in phagocytic vacuoles and the envelopes of these particles did not appear to interact with the vacuolar membrane. The infectious particles were represented by endocytic vesicles containing only the core of HIV after fusion between the viral envelope and endocytic membrane. Fusion between the viral envelope and plasma membrane on the cellular surface was never observed, in spite of examining greater than 1000 virions bound the surface of human and rabbit macrophage monocytes. The absence of cytopathic effect in the rabbit and human CD4 negative monocytes infected with HIV-1, and conversely the presence of specific sequences of HIV in the genomic DNA may indicate that the macrophages-monocytes serve as an important reservoir for the persistence of HIV in infected hosts, similar to the other related Lentiviruses. Our virological data have also demonstrated that virus infection can be transmitted from rabbit and human infected monocytes to uninfected H9 cells. This preliminary study may offer important evidence for the development and testing of vaccines and compounds that inhibit HIV penetration of susceptible cells.

Animals↗
PubMed1991

Sensitivity and specificity of anti-HIV ELISA employing recombinant (p24, p66, gp120) and synthetic (gp41) viral antigenic peptides.

We have developed two immunoassay systems, one designated HIV (p24, p66, gp41) ELISA that uses as antigens the immunodominant epitopes mixed from each of three major groups of HIV-1 proteins: the core (p24), the pol (p66) and the env (gp41) gene. The other immunoassay system consists of four separate ELISAs for detection of single antibodies to HIV gag gene (p24), HIV pol gene (p66) and HIV env gene (gp41 and gp120). In the present study 200 specimens from patients with AIDS and 200 specimens from patients with ARC were repeatedly positive by HIV (p24, p66, gp41) ELISA. 1425 specimens from HIV drug addicts positive at W.B. were positive at HIV (p24, gp41, p66) ELISA. In addition, 60 samples that were indeterminate by W.B., were repeatedly positive at HIV (p24, p66, gp41) ELISA. The sensitivity and specificity of HIV (p24, p66, gp41) is estimated to be 100%. In this study 1507 specimens from HIV drug addicts, positive at W.B., were all positive (more than one test positive) at HIV p24 ELISA, HIV gp41 ELISA, HIV p66 ELISA and HIV gp120 ELISA used in combination. 135 samples from HIV positive drug addicts, positive at standard ELISA but indeterminate at W.B., were positive by HIV p24 ELISA, HIV gp41 ELISA, HIV p66 ELISA and HIV gp120 ELISA using the same criteria as in W.B. interpretation. The specificity (defined in terms of percentage of non-reacting persons in a low risk population) of HIV p24 ELISA, HIV gp41 ELISA, HIV p66 ELISA, HIV gp120 ELISA is 100%. In this work we demonstrated that: a) HIV (p24, p66, gp41) ELISA could be used as an adjunct or reliable alternative to standard ELISA for detection or confirmation of HIV antibodies in human sera; b) the specificity and sensitivity of antibodies to p24, p66, gp41, gp120 by ELISA used alone and/or in combination, is equal to or greater than W.B.

AIDS-Related Complex↗
PubMed1991

Duration of immune protection after hepatitis B vaccine in newborns from HBsAg-positive carrier mothers.

A group of 43 healthy neonates born from HBsAg-positive mothers were evaluated for the presence of protective HBsAb titre after administration of hepatitis B plasma-derived vaccine and hepatitis B hyperimmune-globulin. At 36 months of life we found that a significant number of children had a low HBsAb serum level. This suggests that a close serologic follow-up is necessary to evaluate the optimal timing for the administration of a booster dose of the vaccine.

Carrier State↗
PubMed1991

Detection of antibodies to p24 and gp41 epitopes of HIV by ELISA using the recombinant core protein (p24) and envelope synthetic protein (gp41).

We have developed a system consisting of two separate ELISA, one designed to detect antibodies to HIV gag gene (p24) and the other to detect antibodies to HIV env gene (gp41). The antigen used in these ELISA was produced as recombinant DNA-derived proteins expressed in E. coli for HIV gag gene (p24) and synthetic peptide for the HIV env gene (gp41). These HIV (env-gag) ELISA, that provide independent determinations of the antibody response to the core and envelope proteins, are highly specific and sensitive. In this work we have demonstrated that determinations of antibodies such as those to p24 and gp41 by HIV (env-gag) ELISA are among the criteria for a confirmation procedure, and sensitivity one (gp41) and/or both these determination should be equal or greater than the sensitivity of W.B. In addition, the procedure should be objective and standardized and the antigen source used should be different from that adopted in the "classical" W.B. and screening test. In view of these considerations, this HIV (env-gag) ELISA could be used as a reliable alternative to W.B. for confirmation of antibody detection.

AIDS Serodiagnosis↗
PubMed1991

The association of "standard ELISA" and HIV (env) ELISA for detection and confirmation of HIV antibodies in human sera.

Sera from various population of subjects, including patients with AIDS and ARC, drug-addicts seropositive for HIV and healthy blood donors were screened with "standard ELISA" and HIV (env) ELISA. In the present study all 80 specimens from patients with AIDS and all 60 patients with ARC were positive by HIV (env) ELISA, and 1507 specimens from HIV drug positive by W.B. were detected as positive by HIV (env) ELISA. The specificity of HIV (env) ELISA was defined in terms of percentage of non-reacting persons in a low risk population is 100%. Furthermore the HIV (env) ELISA is highly specific and sensitive and could be used in association with "standard ELISA" for detection and confirmation of HIV antibodies in human sera and plasma.

AIDS Serodiagnosis↗
PubMed1990

Effect of teicoplanin and vancomycin on Staphylococcus aureus ultrastructure.

Morphological changes induced by teicoplanin and vancomycin on Staphylococcus aureus have been comparatively evaluated. The most pronounced structural damages were found on the cell wall which was uniformly thickened on bacteria exposed to teicoplanin while it was of irregular thickness and often absent around the cells in those exposed to vancomycin. The inhibitory action of teicoplanin on proteoglycan polymerization but not on nucleic acid and protein synthesis indicates that the effect in the wall is due to the accumulation at this level of proteoglycan soluble precursors continuously produced by the cell. The different effects induced by vancomycin on cell wall morphology can also be related to the compatibility of this antibiotic in altering cytoplasmatic membrane function and ribonucleic acid synthesis.

Anti-Bacterial Agents↗
PubMed1990

Kinetics of p24 antigenemia, IgM, IgG antibodies to p24 and p41 and Ig virus isolation in rabbits experimentally infected with HIV-1.

In rabbits experimentally infected with 1.10(5) u.i./ml HIV, IgM antibodies were detected 10-15 days after infection, reaching peak value two weeks later and remaining stable for two weeks long. Then a the IgM serotiters progressively decreased and were negative at ten weeks. HIV p24 antigen was detected ten-fifteen days after infection, reaching peak value five-six weeks later. Antigenemia subsequently decreased and reached a second peak after nine weeks. In our experimental conditions, the antigenemia persisted throughout the observation period. The IgG antibody titer reached a maximum two weeks after infection; the time course showed a decrease after ten weeks, followed by progressively decreasing fluctuating course. After twenty four weeks of infection the serotiter values though lower were always positive. Three-four weeks after infection we detected IgG antibodies to the major core protein p24. Reactivity of IgG antibodies to gp41 was observed earlier than reactivity to p24; these antibodies were detected over six months after infection. Viruses indistinguishable from HIV were isolated from the peripheral blood mononuclear cells of infected rabbits 30, 60 and 180 days after infection. These data further confirm that the rabbit may serve as an economical and reproducible model for HIV infection in which vaccines and antiviral agents could be tested.

Animals↗
PubMed1989

Immune responses associated with early survival after peroral infection with Toxoplasma gondii.

After peroral infection with cysts of Toxoplasma gondii, C57BL/6 mice died and A/J mice survived. To better understand the reasons for this difference in survival, host defenses during acute infection were studied: initial portal of entry of T. gondii contributed to susceptibility as more C57BL/6 mice survived after i.p. than peroral infection (p less than 0.001). Susceptible (C57BL/6) mice had more necrosis and inflammation in their brains, livers, and mesenteric lymph nodes than resistant (A/J) mice. Susceptible mice had less IgM antibody to T. gondii (p less than 0.0005) than resistant mice 7 days after infection, but amounts of IgG antibody to T. gondii were similar. Infection reduced percentages of spleen cells with the Lyt-2+ phenotype in susceptible (p less than 0.02) but not resistant mice; infection decreased percentages of spleen cells with the L3T4+ phenotype similarly in both strains of mice. Spleen cells from infected susceptible mice had greater depression in their blastogenic response to Con A (p less than 0.05) and produced significantly more IFN-gamma in culture with (p = 0.009) or without (p less than 0.05) Toxoplasma Ag than spleen cells from infected resistant mice. Infection increased serum levels of IFN-gamma substantially in susceptible but not resistant mice. Lymphocyte IL-2 production was similar in both groups of mice. Peritoneal macrophages from both strains of mice became activated to inhibit or kill T. gondii by 7 days after infection, but Kupffer cells became activated only in susceptible mice. These results indicate that increased resistance to peroral Toxoplasma infection is likely to be mediated by a number of immune responses acting together. They suggest that increased susceptibility may result from inadequately regulated inflammatory responses that increase tissue destruction.

Animals↗
PubMed1989

[In vitro sensitivity of 3 strains of Leptospira interrogans to 3 different antibiotics].

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.

Drug Resistance, Microbial↗