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Biomedical subjects

P Bonfanti

Publications and source records attributed to P Bonfanti.

At least 19 recordsLinked to original sources
PubMed2004

Osteopenia and osteoporosis in HIV+ patients, untreated or receiving HAART.

In the last few years there are increasing evidences suggesting that osteopenia and osteoporosis are frequent among HIV positive patients. It is still not clear if the bone demineralization is a direct consequence of viral infection or of the antiretroviral drugs. Studies to date therefore give conflicting results. We performed a study to evaluate the prevalence of osteopenia and osteoporosis in HIV positive patients, either untreated or receiving antiretroviral therapy, to asses the frequency of these conditions and the role of antiretroviral drugs.

Adult↗
PubMed2001

Predictors of protease inhibitor-associated adverse events.

Risk factors in the development of adverse reactions in HIV-1-infected patients treated with highly active antiretroviral therapy (HAART) containing protease inhibitors are poorly understood. To identify predictors of protease inhibitor-associated adverse events, we are conducting a prospective, cohort, multicenter study on HIV-positive patients starting treatment with at least one protease inhibitor. Rate ratios (RR) of adverse events were calculated, and logistic regression was used to adjust simultaneously for the potentially confounding effects of selected variables, according to the Cox model. A total of 1477 patients have been enrolled up to April 2000, having an average age of 37.1 years (SD +/- 8.1); 1066 (72.2%) were male. Where risk factors for HIV infection are concerned, the distribution was as follows: 48.1% intravenous drug users, 31.6% heterosexual contacts, 16.2% homosexual males and 0.7% blood transfusion. Average CD4+ lymphocyte count at enrollment was 265 cells/mmc (SD +/- 201). Average follow-up time is equal to 17.8 months (range 1-32). The risk of developing adverse reactions is significantly increased in female patients, older patients, hemophiliac subjects and in subjects with hepatitis. Patients treated with ritonavir, the association ritonavir-saquinavir HGC, stavudine and efavirenz have significantly increased incidence of adverse reactions in PI-containing regimens; conversely, saquinavir HGC, zidovudine and lamivudine use was associated with a lower risk of developing adverse reactions.

Adult↗
PubMed2001

Osteonecrosis in protease inhibitor-treated patients.

The introduction of protease inhibitors has proven a watershed in human immunodeficiency virus infection therapy and has initiated an era of highly active antiretroviral therapy. However, the numerous data on the effectiveness of these therapeutic regimens have been cited with an ever-growing number of communications concerning adverse reactions. In particular, the widescale use of protease inhibitors has underlined a series of events not evidenced in the controlled clinical studies that permitted the registration of these drugs. We are conducting a cohort multicenter study to evaluate the incidence of adverse events during treatment with protease inhibitors. To date, 4 cases of bilateral osteonecrosis of the femoral head have been reported out of 1073 person-years. While the pathogenesis of this event is unclear, it may be a long-term complication of protease inhibitor treatment.

Adult↗
PubMed2000

Incidence of adverse reactions in HIV patients treated with protease inhibitors: a cohort study. Coordinamento Italiano Studio Allergia e Infezione da HIV (CISAI) Group.

OBJECTIVE: To assess the probability that protease inhibitor (PI) therapy might be discontinued because of adverse events (AE) and to evaluate the incidence rate of adverse reactions during PI treatment. DESIGN: A prospective cohort, multicenter study on HIV-positive patients starting treatment with at least one PI. SETTING: Ten departments of infectious diseases in Northern Italy. PATIENTS: A total of 1207 patients who started PI therapy in September 1997 and were consecutively observed up to April 1999. MAIN OUTCOME MEASURES: Adverse reactions following initiation of PI therapy, and time to therapy discontinuation due to AE. RESULTS: During the study period, 35.9% patients presented adverse reactions of any grade, whereas 9.7% presented at least one serious AE. After 12 months of treatment, the percentage of patients who had interrupted treatment was 36% of ritonavir-treated patients, 14.2% of those treated with indinavir, 13.6% of ritonavir-saquinavir hard gel capsules (HGC)-treated patients, and 8.5% and 2.1%, respectively, for those treated with nelfinavir and saquinavir HGC. Women and patients with hepatitis experienced a significantly greater number of adverse events compared with other categories. Gastrointestinal events were more frequently observed in patients treated with either ritonavir alone or in combination with saquinavir HGC, as well as in patients receiving nelfinavir, although in this group serious events were rare. Here again, neurologic, metabolic, and hepatic toxicity occurred more frequently in ritonavir and ritonavir-saquinavir HGC treated patients. Allergic reactions were more often observed in patients receiving nelfinavir. Indinavir-treated patients presented the highest incidence of renal toxicity. CONCLUSION: Ritonavir is the drug associated with the largest number of reactions, which appear during the first few months of treatment. Saquinavir HGC and nelfinavir are the best tolerated drugs in a clinical setting.

Adult↗
PubMed2000

The effectiveness of desensitization versus rechallenge treatment in HIV-positive patients with previous hypersensitivity to TMP-SMX: a randomized multicentric study. C.I.S.A.I. Group.

Our study was undertaken to evaluate if desensitization treatment is more effective than rechallenge in preventing hypersensitivity reactions in HIV-positive patients with previous allergic reactions to TMP-SMX; the secondary aim was to evaluate the frequency of reactions to TMP alone. This was a randomized, multicentre open study. Patients with previous documented hypersensitivity to TMP-SMX who required primary or secondary PCP prophylaxis were enrolled; subjects who had previously had serious adverse reactions to TMP-SMX were excluded. All eligible patients assumed 200 mg TMP for 14 days and in case of no reactions were randomized for desensitization or rechallenge with TMP-SMX. The patients were then followed up by periodical visits for six months. Seventy-three patients were enrolled; 14 subjects (19%) presented reactions on TMP alone during the pre-enrollment phase. The remaining 59 subjects were randomly assigned to the two treatment groups: 34 carried out desensitization (group 1) and 25 rechallenge (group 2) with TMP-SMX. Seven patients in group 1 (20.5%) and seven in group 2 (28%) showed hypersensitivity reactions during treatment; this difference was not statistically significant. No serious reaction occurred in either group. This study showed the comparable effectiveness of the desensitization procedure and rechallenge in patients with a previous, not serious, allergic reaction to TMP-SMX.

Adult↗
PubMed2000

HAART tolerability: post-exposure prophylaxis in healthcare workers versus treatment in HIV-infected patients.

The aim of our study is to compare the tolerability of zidovudine/lamivudine/indinavir when used in post-exposure prophylaxis (PEP) subjects and in HIV-infected patients. HIV-negative patients were enrolled as part of the surveillance protocol for professional exposure at the Luigi Sacco Hospital in Milan. HIV-positive patients were selected among all subjects undergoing treatment with zidovudine/lamivudine/indinavir from the CISAI cohort, an Italian cohort for the evaluation of adverse reactions to HAART. In both studies patients were followed prospectively and the severity of the reactions was evaluated using the AIDS Clinical Trial Group adverse experience grading scales. Up to September 1999, 37 HIV-seronegative subjects had undergone treatment with zidovudine/ lamivudine/indinavir. From a total of 1207 patients belonging to the CISAI cohort, 199 were identified as being treated with the same regimen. The frequency of adverse events in the PEP subjects was 70.3% compared to 11.1% for HIV-infected patients. In the first group, adverse events caused treatment interruption in 21 subjects (56.7%) versus 14 patients (7%) among the HIV-infected group. Only one case of a severe event (grade 3-4) was observed in the prophylaxis group against 12 in the treatment group. Our study shows that treatment interruption is eight times higher in HIV-negative subjects compared to HIV-seropositive patients, and that the incidence of adverse events is approximately six times higher, though such events, are for the most part, not severe.

Adult↗
PubMed1999

HIV disease treatment in the era of HAART.

In the last three years basic science and clinical research have radically changed the therapeutical approach to HIV disease. Recent guidelines suggest that treatments to HIV disease should be early and aggressive, with the use of new potent antiretroviral drugs. This approach has been defined as HAART (highly active antiretroviral therapy). In this review we will discuss the main stages of antiretroviral therapy focusing on the acquisitions about results as well as problems of triple therapy.

Anti-HIV Agents↗
PubMed1999

Acetylator phenotype prevalence in HIV-infected patients without previous trimethoprim-sulfamethoxazole hypersensitivity.

This trial was conducted to study the frequency of the slow acetylator phenotype in asymptomatic HIV patients having no previous reaction to sulfa-drugs, and to compare this frequency with the frequency found in healthy controls. Results show that HIV alone is not capable of modifying the acetylator phenotype; the prevalence of slow acetylator phenotype is the same in immune competent subjects and HIV-positive patients. It is more common in HIV-positive patients with a CD4+ lymphocyte count of less than 200 mm-3.

Acetylation↗
PubMed1998

Molecular approaches to evaluate pollutants.

Many organisms are in use to test pollutants and their extensive variability clearly emerges from reviews since researchers in the world are involved in continuous effort to set up new assays and to improve those already in use. In the present paper we focus the attention on the mixed function oxidase system and the DNA adduct formation which are two biomarkers widely used and extensively studied in mammals and fish by different Authors. We compare their results with the ones we obtained in amphibians, which result to be a good model. Moreover we present some significative results obtained by the use of cultured cell lines to test the herbicide MCPA. The results obtained demonstrate that the amphibian Xenopus is a suitable indicator for induction of cytochrome P-450 by B[a]P as well as for production of DNA adducts. Cultured cells evidenced that cytoskeletal array and thiol proteins are molecular targets of the herbicide used, demonstrating that risk assessment can be properly analysed in in vitro systems.

2-Methyl-4-chlorophenoxyacetic Acid↗
PubMed1998

Identification of a multixenobiotic resistance mechanism in Xenopus laevis embryos.

In the '90's a membrane-associated transport protein, discovered in aquatic organisms, was considered to be expressed in response to environmental xenobiotics. Like the multidrug resistance protein found in mammalian tumor cell lines, this protein confers resistance in organisms in polluted areas by binding xenobiotics and transporting them out of the cells in an energy-dependent manner. This study investigates the expression and the activity of a P-glycoprotein (Pgp) involved in a multixenobiotic resistance mechanism (MXRM) during the early developmental stages and in tissues of adult Xenopus laevis.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1998

Physical-chemical and ecotoxicological evaluation of water based drilling fluids used in Italian off-shore.

In order to evaluate the effects on the marine ecosystem caused by an eventual discharge into sea of water based drilling fluids, as current legislation allows, chemical and ecotoxicological analyses were performed on the most common drilling muds and products used in Italian off-shore activities. The chemical analysis on drilling fluids involved the leaching test and the measurement of total content of heavy metals, whereas biodegradation tests were performed on the products used in mud's formulations. As for ecotoxicological evaluation, two marine organisms, the crustacean Artemia salina and the diatom Phaeodactylum tricornutum, were selected to determine the LC50 and the EC50 respectively.

Animals↗