Biomedical subjects

F Palmieri

Publications and source records attributed to F Palmieri.

At least 19 recordsLinked to original sources

PubMed2006

Magnetization transfer analysis of cartilage repair tissue: a preliminary study.

PURPOSE: To evaluate the magnetization transfer ratio (MTR) after two different cartilage repair procedures, and to compare these data with the MTR of normal cartilage. DESIGN AND PATIENTS: Twenty-seven patients with a proven cartilage defect were recruited: 13 were treated with autologous chondrocyte implantation (ACI) and 14 were treated with the microfracture technique (MFR). All patients underwent MRI examinations with MT-sequences before the surgical treatment, after 12 months (26 patients) and after 24 months (11 patients). Eleven patients received a complete follow-up study at all three time points (five of the ACI group and six of the MFR group). All images were transferred to a workstation to calculate MTR images. For every MT image set, different ROIs were delineated by two radiologists. Means were calculated per ROI type in the different time frames and in both groups of cartilage repair. The data were analyzed with unpaired t- and ANOVA tests, and by calculating Pearson's correlation coefficient. RESULTS: No significant differences were found in the MTR of fatty bone marrow, muscle and normal cartilage in the different time frames. There was a significant but small difference between the MTR of normal cartilage and the cartilage repair area after 12 months for both procedures. After 24 months, the MTR of ACI repaired cartilage (0.31+/-0.07) was not significantly different from normal cartilage MTR (0.34+/-0.05). The MTR of MFR repaired cartilage (0.28+/-0.02), still showed a significant difference from normal cartilage. CONCLUSION: The differences between damaged and repaired cartilage MTR are too small to enable MT-imaging to be a useful tool for postoperative follow-up of cartilage repair procedures. There is, however, an evolution towards normal MTR-values in the cartilage repair tissue (especially after ACI repair).

Adult↗

PubMed2005

Pulmonary cryptosporidiosis in an AIDS patient: successful treatment with paromomycin plus azithromycin.

Extra-intestinal cryptosporidiosis, especially of the biliary and respiratory tract, is likely in the course of an intestinal involvement, whereas it is rare without such a localization. We report a case of pulmonary cryptosporidiosis without apparent intestinal involvement in an AIDS patient, with favourable outcome after antimicrobial combination therapy with paromomycin plus azithromycin. The successful response to antimicrobial treatment was subsequently maintained by effective highly active antiretroviral therapy (HAART). We suggest that respiratory cryptosporidiosis should be investigated in HIV-infected patients with pulmonary symptoms and low CD4 cell count, and, if detected, treatment should include HAART plus the combination of paromomycin and azithromycin.

AIDS-Related Opportunistic Infections↗

PubMed2004

Identification of the human mitochondrial S-adenosylmethionine transporter: bacterial expression, reconstitution, functional characterization and tissue distribution.

The mitochondrial carriers are a family of transport proteins that, with a few exceptions, are found in the inner membranes of mitochondria. They shuttle metabolites and cofactors through this membrane, and connect cytoplasmic functions with others in the matrix. SAM (S-adenosylmethionine) has to be transported into the mitochondria where it is converted into S-adenosylhomocysteine in methylation reactions of DNA, RNA and proteins. The transport of SAM has been investigated in rat liver mitochondria, but no protein has ever been associated with this activity. By using information derived from the phylogenetically distant yeast mitochondrial carrier for SAM and from related human expressed sequence tags, a human cDNA sequence was completed. This sequence was overexpressed in bacteria, and its product was purified, reconstituted into phospholipid vesicles and identified from its transport properties as the human mitochondrial SAM carrier (SAMC). Unlike the yeast orthologue, SAMC catalysed virtually only countertransport, exhibited a higher transport affinity for SAM and was strongly inhibited by tannic acid and Bromocresol Purple. SAMC was found to be expressed in all human tissues examined and was localized to the mitochondria. The physiological role of SAMC is probably to exchange cytosolic SAM for mitochondrial S-adenosylhomocysteine. This is the first report describing the identification and characterization of the human SAMC and its gene.

Amino Acid Sequence↗

PubMed2004

Tuberculosis in HIV-infected persons in the context of wide availability of highly active antiretroviral therapy.

Highly active antiretroviral therapy (HAART) greatly reduces the risk of developing tuberculosis for HIV-infected persons. Nonetheless, HIV-associated tuberculosis continues to occur in countries where HAART is widely used. To identify the characteristics of HIV-infected persons who develop tuberculosis in the context of the availability of HAART, the current authors analysed data taken from 271 patients diagnosed, in Italy, during 1999-2000. These patients represent 0.7% of the 40,413 HIV-infected patients cared for in the clinical units participating in this current study. From the data it was observed that 20 patients (7.4%) had a previous episode of tuberculosis whose treatment was not completed. Eighty-one patients (29.9%) were diagnosed with HIV at tuberculosis diagnosis, 108 (39.8%) were aware of their HIV status but were not on antiretroviral treatment and 82 (30.3%) were on antiretroviral treatment. Patients on antiretroviral treatment were significantly less immunosuppressed than patients with HIV diagnosed concurrently with tuberculosis, or other patients not on antiretrovirals (median CD4 lymphocytes count: 220 cells x mm(-3) versus 100 cells x mm(-3), and 109 cells x mm(-3), respectively). No significant differences in clinical presentation of tuberculosis according to antiretroviral therapy status were recorded. Failure of tuberculosis control interventions (e.g. noncompletion of treatment) and of HIV care (delayed diagnosis of HIV infection and suboptimal uptake of therapy) may contribute to continuing occurrence of HIV-associated tuberculosis in a country where highly active antiretroviral therapy is largely available. However, a significant proportion of cases occur in patients who are on antiretroviral treatment.

AIDS-Related Opportunistic Infections↗

PubMed2004

Remission of Behçet's disease and keratoconjunctivitis sicca in an HIV-infected patient treated with HAART.

A 34-year-old woman presented with a 10-year history of recurrent oral and genital ulcerations and recurrent episodes of bilateral conjunctivitis associated with HIV infection. A diagnosis of Behçet's disease (BD) in association with keratoconjunctivitis sicca (KCS) was made after exclusion of other viral and autoimmune diseases according to the international criteria for BD. This is the first reported case of a combination of BD and KCS in a patient with HIV infection in which a complete resolution was observed as a result of successful highly active antiretroviral therapy. The likelihood that a direct viral effect or HIV-induced autoimmune mechanisms act in the pathogenesis of both BD and KCS in HIV-infected patients is discussed.

Adult↗

PubMed2004

[Guidelines for the management of HCV infection in HIV-infected patients. Istituto Nazionale per le Malattie Infettive Lazzaro Spallanzani].

It is crucial to ensure an optimal clinical management of HCV infection in HIV-co-infected persons. The reasons for the development of guidelines on HCV-infection treatment in HIV-infected persons arise from the need for a standardised management of HIV/HCV coinfection in our Institute. The aim of these guidelines are: to clarify principles of clinical management of HCV infection in HIV-infected patients to care-providers; to improve the awareness of HIV-infected patients cared for our Institute on current management of HCV infection; to improve the quality of care on this topic. These guidelines, based on Evidence based Medicine principles, have been developed by a panel of experts, who conducted a systematic review of the literature, mainly taking into account current international recommendations. In the present document, the most frequent clinical presentation occurring in the management of HIV/HCV co-infected patients at our Institution are discussed. The adherence to present guidelines and their effectiveness at our Institution, outcome indicators will be evaluated. The present guidelines cannot entirely substitute the judgement of an expert clinician. However, adherence to these guidelines will contribute to the improvement of the standard of care of HIV/HCV-co-infected persons.

Anti-HIV Agents↗

PubMed2003

Identification and functional reconstitution of yeast mitochondrial carrier for S-adenosylmethionine.

The genome of Saccharomyces cerevisiae contains 35 members of the mitochondrial carrier protein family, most of which have not yet been functionally identified. Here the identification of the mitochondrial carrier for S-adenosylmethionine (SAM) Sam5p is described. The corresponding gene has been overexpressed in bacteria and the protein has been reconstituted into phospholipid vesicles and identified by its transport properties. In confirmation of its identity, (i) the Sam5p-GFP protein was found to be targeted to mitochondria; (ii) the cells lacking the gene for this carrier showed auxotrophy for biotin (which is synthesized in the mitochondria by the SAM-requiring Bio2p) on fermentable carbon sources and a petite phenotype on non-fermentable substrates; and (iii) both phenotypes of the knock-out mutant were overcome by expressing the cytosolic SAM synthetase (Sam1p) inside the mitochondria.

Biotin↗

PubMed2003

Radiological patterns in HIV-associated pulmonary tuberculosis: comparison between HAART-treated and non-HAART-treated patients.

AIM: To evaluate whether highly active antiretroviral therapy (HAART) modifies radiographic appearances of pulmonary tuberculosis (TB), in terms of patterns and their relative frequencies, among patients with human immunodeficiency virus (HIV) infection. MATERIALS AND METHODS: Chest radiographs were obtained in 209 HIV-infected patients with culture confirmed pulmonary TB. Computed tomography (CT) images were also reviewed for 42 patients whose chest radiographs were normal or showed questionable abnormalities. Imaging was evaluated for the presence and distribution of consolidation, cavitation, interstitial changes, pleural disease, adenopathy, and were classified as a primary or post-primary pattern. RESULTS: A post-primary pattern was more frequent after 1996 when HAART came into clinical use. Forty-four percent (77/176) of patients not on HAART had a post-primary pattern in comparison with 82% (27/33) of patients receiving HAART (p<0.001). A primary pattern was significantly more frequent (p<0.001), in patients with more severe immunosuppression (CD4 lymphocyte less than 200/mm(3)). CONCLUSION: HIV patients receiving HAART with pulmonary TB, had a post-primary pattern more frequently than those not receiving this treatment. This observation is consistent with the partial restoration of cell-mediated immunity that can be induced by HAART.

AIDS-Related Opportunistic Infections↗

PubMed2003

Identification and metabolic role of the mitochondrial aspartate-glutamate transporter in Saccharomyces cerevisiae.

The malate-aspartate NADH shuttle in mammalian cells requires the activity of the mitochondrial aspartate-glutamate carrier (AGC). Recently, we identified in man two AGC isoforms, aralar1 and citrin, which are regulated by calcium on the external face of the inner mitochondrial membrane. We have now identified Agc1p as the yeast counterpart of the human AGC. The corresponding gene was overexpressed in bacteria and yeast mitochondria, and the protein was reconstituted in liposomes where it was identified as an aspartate-glutamate transporter from its transport properties. Furthermore, yeast cells lacking Agc1p were unable to grow on acetate and oleic acid, and had reduced levels of valine, ornithine and citrulline; in contrast they grew on ethanol. Expression of the human AGC isoforms can replace the function of Agc1p. However, unlike its human orthologues, yeast Agc1p catalyses both aspartate-glutamate exchange and substrate uniport activities. We conclude that Agc1p performs two metabolic roles in Saccharomyces cerevisiae. On the one hand, it functions as a uniporter to supply the mitochondria with glutamate for nitrogen metabolism and ornithine synthesis. On the other, the Agc1p, as an aspartate-glutamate exchanger, plays a role within the malate-aspartate NADH shuttle which is critical for the growth of yeast on acetate and fatty acids as carbon sources. These results provide strong evidence of the existence of a malate-aspartate NADH shuttle in yeast.

Acetates↗

PubMed2002

Identification and reconstitution of the yeast mitochondrial transporter for thiamine pyrophosphate.

The genome of Saccharomyces cerevisiae contains 35 members of a family of transport proteins that, with a single exception, are found in the inner membranes of mitochondria. The transport functions of the 15 biochemically identified mitochondrial carriers are concerned with shuttling substrates, biosynthetic intermediates and cofactors across the inner membrane. Here the identification of the mitochondrial carrier for the essential cofactor thiamine pyrophosphate (ThPP) is described. The protein has been overexpressed in bacteria, reconstituted into phospholipid vesicles and identified by its transport properties. In confirmation of its identity, cells lacking the gene for this carrier had reduced levels of ThPP in their mitochondria, and decreased activity of acetolactate synthase, a ThPP-requiring enzyme found in the organellar matrix. They also required thiamine for growth on fermentative carbon sources.

Carbon↗

PubMed2002

Pulmonary tuberculosis in HIV-infected patients presenting with normal chest radiograph and negative sputum smear.

BACKGROUND: HIV-infected patients with pulmonary tuberculosis exhibit atypical radiological presentation and negative sputum smear more frequently than their HIV-negative counterparts. PATIENTS AND METHODS: We performed a retrospective study based on a chart review of 146 HIV-infected patients with pulmonary symptoms and culture-proven pulmonary tuberculosis. We compared clinical characteristics and the outcome in 71 patients (49%) with positive sputum smear (SS+), 62 patients (42%) with negative sputum smear/abnormal chest X-ray (SS-/CXR+) and 13 patients (9%) with negative sputum smear/normal chest X-ray (SS-/CXR-). Patients were enrolled from January 1987 to December 1998, and were followed up until December 1999. RESULTS: On hospital admission the three groups of patients examined did not differ significantly in demographic characteristics, degree of immunosuppression or Mycobacterium tuberculosis drug-susceptibility pattern. SS-/CXR- patients were significantly Less LikeLy to present with prolonged fever and dyspnea. Median survival was shorter for SS-/CXR- patients (6.4 months vs 20.2 and 18.8 months in the other two groups). In multivariate analysis, SS-/CXR-patients had a significantly increased risk of death (hazard ratio 3.0, 95% confidence interval, 1.4 to 6.4, p = 0.004) compared to SS+ patients. This increase in risk was no longer statistically significant when initiation of antituberculous therapy within 8 weeks from the collection date of the first specimen yielding M. tuberculosis was included in the multivariate model. CONCLUSION: Decreased survival was observed in HIV-infected patients with pulmonary tuberculosis and with both negative sputum smear and normaL chest X-ray presentation. This may primarily be a resuLt of delayed tuberculosis diagnosis and initiation of antituberculous therapy. The latter delay may also lead to a faster progression of HIV infection in SS-/CXR patients, in whom diagnostic oversight may be common.

AIDS-Related Opportunistic Infections↗

PubMed2001

The mitochondrial oxoglutarate carrier: cysteine-scanning mutagenesis of transmembrane domain IV and sensitivity of Cys mutants to sulfhydryl reagents.

Using a functional mitochondrial oxoglutarate carrier mutant devoid of Cys residues (C-less carrier), each amino acid residue in transmembrane domain IV and flanking hydrophilic loops (from T179 to S205) was replaced individually with Cys. The great majority of the 27 mutants exhibited significant oxoglutarate transport in reconstituted liposomes as compared to the activity of the C-less carrier. In contrast, Cys substitution for G183, R190, Q198, and Y202, in either C-less or wild-type carriers, yielded molecules with complete loss of oxoglutarate transport activity. G183 and R190 could be partially replaced only by Ala and Lys, respectively, whereas Q198 and Y202 were irreplaceable with respect to oxoglutarate transport. Of the single-Cys mutants tested, only T187C, A191C, V194C, and N195C were strongly inactivated by N-ethylmaleimide and by low concentrations of methanethiosulfonate derivatives. Oxoglutarate protects Cys residues at positions 187, 191, and 194 against reaction with N-ethylmaleimide. These positions as well as the residues found to be essential for the carrier activity, except Y202 which is located in the extramembrane loop IV-V, reside on the same face of transmembrane helix IV, probably lining part of a water-accessible crevice or channel between helices of the oxoglutarate carrier.

Amino Acid Sequence↗

PubMed2001

Endocarditis caused by Aspergillus species in injection drug users.

Aspergillus endocarditis is a rare event; a very few cases have been reported in injection drug users (IDUs) and patients infected with human immunodeficiency virus (HIV). We report 2 proven cases and 1 highly suggestive case of Aspergillus endocarditis in IDUs, 2 of whom were infected with HIV, and discuss some related clinical and pathogenic aspects.

AIDS-Related Opportunistic Infections↗

PubMed2001

Identification and functional reconstitution of the yeast peroxisomal adenine nucleotide transporter.

The requirement for small molecule transport systems across the peroxisomal membrane has previously been postulated, but not directly proven. Here we report the identification and functional reconstitution of Ant1p (Ypr128cp), a peroxisomal transporter in the yeast Saccharomyces cerevisiae, which has the characteristic sequence features of the mitochondrial carrier family. Ant1p was found to be an integral protein of the peroxisomal membrane and expression of ANT1 was oleic acid inducible. Targeting of Ant1p to peroxisomes was dependent on Pex3p and Pex19p, two peroxins specifically required for peroxisomal membrane protein insertion. Ant1p was essential for growth on medium-chain fatty acids as the sole carbon source. Upon reconstitution of the overexpressed and purified protein into liposomes, specific transport of adenine nucleotides could be demonstrated. Remarkably, both the substrate and inhibitor specificity differed from those of the mitochondrial ADP/ATP transporter. The physiological role of Ant1p in S.cerevisiae is probably to transport cytoplasmic ATP into the peroxisomal lumen in exchange for AMP generated in the activation of fatty acids.

Adenosine Triphosphate↗

PubMed2001

Citrin and aralar1 are Ca(2+)-stimulated aspartate/glutamate transporters in mitochondria.

The mitochondrial aspartate/glutamate carrier catalyzes an important step in both the urea cycle and the aspartate/malate NADH shuttle. Citrin and aralar1 are homologous proteins belonging to the mitochondrial carrier family with EF-hand Ca(2+)-binding motifs in their N-terminal domains. Both proteins and their C-terminal domains were overexpressed in Escherichia coli, reconstituted into liposomes and shown to catalyze the electrogenic exchange of aspartate for glutamate and a H(+). Overexpression of the carriers in transfected human cells increased the activity of the malate/aspartate NADH shuttle. These results demonstrate that citrin and aralar1 are isoforms of the hitherto unidentified aspartate/glutamate carrier and explain why mutations in citrin cause type II citrullinemia in humans. The activity of citrin and aralar1 as aspartate/glutamate exchangers was stimulated by Ca(2+) on the external side of the inner mitochondrial membrane, where the Ca(2+)-binding domains of these proteins are localized. These results show that the aspartate/glutamate carrier is regulated by Ca(2+) through a mechanism independent of Ca(2+) entry into mitochondria, and suggest a novel mechanism of Ca(2+) regulation of the aspartate/malate shuttle.

Amino Acid Transport Systems, Acidic↗

PubMed2001

Better response to chemotherapy and prolonged survival in AIDS-related lymphomas responding to highly active antiretroviral therapy.

OBJECTIVES: To evaluate the impact of response to highly active antiretroviral therapy (HAART) on the natural history of AIDS non-Hodgkin's lymphoma (NHL) and to analyse the feasibility, efficacy and toxicity of HAART in combination with chemotherapy. DESIGN: Prospective observational study in two AIDS clinical centres in Italy. METHODS: All consecutive HIV-infected patients with NHL were included (n = 44; 48% high-risk group) and prospectively followed for 27 months. HAART was administered concomitantly with chemotherapy. The association between response to HAART and clinical presentation, response to chemotherapy and toxicity was analysed by univariate and multivariate models. Survival analysis was performed by Kaplan-Meier estimates and the Cox proportional hazards regression model. RESULTS: A complete response (CR) to chemotherapy was achieved in 71% of HAART responders and 30% of non-responders. Virological response to HAART was the only variable associated with tumour response on multivariate analysis. A higher relative dose intensity (RDI) of chemotherapy was administered in patients with virological response compared with those without. The probability of 1 year survival was higher in patients with virological or immunological response. At Cox regression analysis, immunological response, a higher RDI and a CR to chemotherapy were all associated with a reduced risk of death. CONCLUSION: In HIV-infected patients with NHL, response to HAART was strongly associated with a better response to chemotherapy and prolonged survival. Concurrent treatments were well tolerated, and HAART-responder patients could receive a higher RDI of chemotherapy. In patients with AIDS lymphomas, combining HAART with chemotherapy could be a feasible and effective approach.

Adult↗

PubMed2001

Biogenesis of the dicarboxylate carrier (DIC): translocation across the mitochondrial outer membrane and subsequent release from the TOM channel are membrane potential-independent.

The mitochondrial inner membrane of Saccharomyces cerevisiae contains a group of homologous carrier proteins that mediate the exchange of several metabolites. The members of this protein family are synthesized in the cytosol and reach their final topology after translocation across the mitochondrial outer membrane. Using the ADP/ATP carrier (AAC) as a model protein, previous studies have established four distinct steps of the import pathway (stages I-IV). In the absence of the mitochondrial membrane potential (deltapsi), the AAC accumulates at the inner surface of the outer membrane (stage IIIa) and remains bound to the outer membrane import channel. Only in the presence of the membrane potential, can a complex of small Tim proteins mediate transfer of the AAC to the inner membrane. In this study, we characterized the import pathway of the dicarboxylate carrier (DIC). Different from the AAC, the DIC showed complete deltapsi-independent translocation across the outer membrane, release from the import pore, and mainly accumulated in a soluble state in the intermembrane space, thus defining a new translocation intermediate (stage III*). The DIC should be a suitable model protein for the characterization of deltapsi-independent functions of the intermembrane space Tim proteins.

Carrier Proteins↗

PubMed2001

Changing clinical presentation and survival in HIV-associated tuberculosis after highly active antiretroviral therapy.

OBJECTIVE: To assess changes in clinical presentation and outcome of HIV-associated tuberculosis (TB) before and after widespread implementation of highly active antiretroviral therapy (HAART). METHODS: We reviewed clinical charts of HIV-infected patients with culture-confirmed pulmonary TB in two referral clinical centers in Rome, Italy. The 67 patients diagnosed in 1995 to 1996 were compared with 51 patients diagnosed in 1997 to 1998. To analyze factors associated with survival we used a Cox model including antiretroviral therapy as a time-dependent covariate. RESULTS: Patients diagnosed in 1997 to 1998 were more likely to have TB as the first AIDS-defining illness (78% versus 58%, p <.05), to have HIV diagnosed <2 months before TB (33% vs. 7%, p <.005) and to have typical chest radiograph pattern (45% vs. 25%, p <.05), and had a higher CD4(+) count (median 105 vs. 43, p <.005). Survival at 1 year was 80% for patients diagnosed in 1997 to 1998 vs. 65% for those diagnosed in 1995 to 1996 (p by log-rank =.02). After adjusting at multivariate analysis, time period of diagnosis was not confirmed as associated with survival (hazard ratio, 1.05; 95% confidence interval, 0.39--2.81). Age, CD4+ cell count <25/mm(3), and AIDS-defining illnesses before TB diagnosis were all associated with an higher risk of death, whereas a decreased risk of death was observed in patients starting a triple combination antiretroviral therapy after TB diagnosis (hazard ratio, 0.14; 95% confidence interval, 0.03--0.57). CONCLUSIONS: Cases of HIV-associated TB occurring in patients with advanced immunosuppression and presenting with atypical radiologic appearance tend to be relatively less common in the HAART era. HAART is a major factor in prolonging survival in these patients.

Adult↗