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Biomedical subjects

G Fiorentino

Publications and source records attributed to G Fiorentino.

At least 19 recordsLinked to original sources
PubMed2003

Development of a genetic system for hyperthermophilic Archaea: expression of a moderate thermophilic bacterial alcohol dehydrogenase gene in Sulfolobus solfataricus.

The Escherichia coli/Sulfolobus solfataricus shuttle vector pEXSs was used as a cloning vehicle for the gene transfer and expression of two bacterial genes in Sulfolobus solfataricus. The alcohol dehydrogenase (adh) from the moderate thermophilic Bacillus stearothermophilus (strain LLDR) and a mutagenised version encoding a less thermostable ADH enzyme were the selected genes. S. solfataricus adh promoter and aspartate aminotransferase terminator were used to drive the heterologous gene expression and to guarantee the correct termination of the transcripts, respectively. The constructed vectors were found to be able to carry these 'passenger' genes without undergoing any rearrangements. The active transcription of bacillar mRNAs was ascertained in vivo by RT-PCR. Transformed S. solfataricus expressed functional exogenous ADHs that showed unaffected kinetic and chemical-physical features.

Alcohol Dehydrogenase↗
PubMed2002

Autochthonous mucosal leishmaniasis in a hemodialyzed Italian patient.

A case of mucosal leishmaniasis in a 60-year old hemodialysis patient who had never lived outside Italy is described. The patient complained of fever, epistaxis and nasal obstruction. An anterior rhinoscopy disclosed a mass of two centimetres in diameter in the right nasal fossa. Histological examination revealed Leishmania amastigotes. Serology for Leishmania was positive with antibody titer of 1/320. A culture yielded a very slow growth of Leishmania infantum MON-24. In spite of a two-month treatment with oral itraconazole, the lesions progressively worsened. Treatment with topical paromomycin sulfate determined the complete resolution of the lesions within four months, with a residual perforation of the septum. This case demonstrates that localization of Leishmania spp must be considered in the differential diagnosis of mucosal lesions in hemodialyzed patients, even in countries not at risk for this parasite. Moreover, this case indicates the important role of the immune system in the evolution of the disease.

Animals↗
PubMed2001

Identification and molecular characterization of an endoglucanase gene, celS, from the extremely thermophilic archaeon Sulfolobus solfataricus.

A genomic region upstream of the alcohol dehydrogenase (Ssadh) gene was cloned and sequenced from a library of Sulfolobus solfataricus MT4 strain. The isolated 4,040-bp DNA fragment revealed an open reading frame (celS), lying in the opposite direction to Ssadh, which showed significant similarity to endo-beta-1,4-glucanases from Pyrococcus furiosus, Thermotoga maritima, and Thermotoga neapolitana. celS was shown to be a functional gene in vivo: a specific celS mRNA was detected by primer extension analysis showing a unique initiation transcription site coinciding with the ATG translation initiation codon. The specific gene product was detected as an extracellular cellulase after enzyme staining by carboxymethyl cellulose (CMC) SDS-PAGE, showing a molecular weight in agreement with that deduced from the open reading frame. Depending on growth conditions, different levels of cellulase activity and specific celS transcript were detected, revealing an inductive effect of CMC and suggesting a repressive role of glucose.

Amino Acid Sequence↗
PubMed2001

Response of severe HIV-associated thrombocytopenia to highly active antiretroviral therapy including protease inhibitors.

OBJECTIVE: To investigate the response of HIV-associated severe thrombocytopenia (STP) to highly active antiretroviral therapy (HAART) including protease-inhibitors. METHODS: In this retrospective study, 15 patients with HIV-associated STP (platelet count < 50 x 10(9)/l mostly antiretroviral experienced (13/15), underwent HAART for at least 6 months (median 21; range 6-41 months) during which the platelet (PLT) count and plasmatic HIV-RNA were monitored. The PLT response was compared to that observed in 19 patients previously treated with zidovudine (AZT) monotherapy. RESULTS: HAART induced a significant increase in the PLT count (chi(2)=10.53, P=0.01) within the third month which was sustained up to the sixth month of therapy. No STP relapse was observed among eight PLT responders followed for longer than 6 months (median 27; range 7-41 months). The PLT increase after HAART was similar to that observed with AZT monotherapy, but a greater number of HAART patients were antiretroviral-experienced. HAART determined a PLT response in 10/13 subjects whose thrombocytopenia had not improved after previous AZT monotherapy. After 6 months of HAART, a complete platelet response occurred more frequently in patients with undetectable plasma HIV-RNA levels (P=0.01). CONCLUSIONS: HAART induces a sustained PLT response in HIV-associated STP, even in antiretroviral-experienced subjects and in those with AZT-resistant thrombocytopenia. An undetectable plasma HIV viraemia induced by HAART is necessary for STP recovery.

Adolescent↗
PubMed2000

Premature lesions of the carotid vessels in HIV-1-infected patients treated with protease inhibitors.

OBJECTIVES: To evaluate the presence of premature atherosclerotic lesions of epiaortic vessels in HIV-1-infected protease inhibitor-(PI) treated patients compared with PI-naive patients and healthy individuals. DESIGN: One-hundred and two HIV-1-positive patients, including 55 treated with PI for at least 12 months and 47 either naive or treated with PI-sparing regimens, were subjected to epiaortic vessel ultrasonography. These data were compared with those obtained from 104 healthy individuals. METHODS: Intima characteristics, pulsation and resistance indexes, and minimal, peak and mean speed were evaluated using a colour power doppler. Atherosclerotic plaques were described. Independent risk factors and values for glycaemia, cholesterolaemia and triglyceridaemia were considered. Statistical analysis included the chi-square test, Mantel-Haenszel test, odds ratio and logistic regression analysis. RESULTS: Of the PI-treated patients, 29 out of 55 (52.7%) presented acquired lesions of the vascular wall at ultrasonography, whereas similar lesions were found in seven out of 47 (14.9%) PI-naive patients. Of the 104 healthy individuals, seven cases (6.7%) of intimal medial thickness were noted. A slightly significant correlation was found between carotid lesions and age, male sex and hypercholesterolaemia, whereas cigarette smoking, hypertriglyceridaemia and Centers for Disease Control and Prevention stage significantly increased the risk of vascular lesions (P= 0.022, P= 0.017 and P= 0.079 respectively). However, the highest significance regarded use of PI (P= 0.011). These results were confirmed by logistic regression analysis. CONCLUSIONS: These data demonstrate a higher than expected prevalence of premature carotid lesions in the PI-treated compared with PI-naive patients. If confirmed, a periodic ultrasonographic study of the vascular wall should be included in the follow-up of HIV infected patients.

Adult↗
PubMed2000

Oxygen: friend or foe? Archaeal superoxide dismutases in the protection of intra- and extracellular oxidative stress.

Both "environmental chemistry" and metabolic biochemical reactions can constantly generate in vivo free radicals and other oxygen-derived species that can cause severe damage to almost all biomolecules, especially to DNA, proteins, and lipids. The superoxide anion has been shown to be the most readily generated and spread radical among organisms and it is a common intermediate of oxidative stress processes in the cells. The antioxidant defense system of superoxide dismutases (SOD) scavenges and minimizes the formation of this radical, and thus plays a major role in reducing cumulative oxidative damage in different cell compartments both in aerobic and anaerobic cells. In the cell, cytosol SODs are constitutively present and induced by many oxidative agents able to raise the superoxide concentrations. Presence of SODs, however, in extracellular cell-associated locations demonstrates how valuable they are in maintaining the integrity of cells against oxidative stress generated by the cell environment, particularly upon increased oxygenation. Because SODs have recently been found in Archaea, which are prokaryotes, sometimes living in extreme environments, even in anaerobic ones, these enzymes can be considered essential: they may have allowed the evolution of aerobic respiration starting from an ancient form of oxygen-insensitive life.

Archaea↗
PubMed2000

Parkinsonism in a patient with AIDS and cerebral opportunistic granulomatous lesions.

The localization of opportunistic infections in the basal ganglia in patients with acquired immunodeficiency syndrome (AIDS) can cause movement disorders, such as choreoathetosis, dystonia, hemiballism and, more rarely, parkinsonism. We describe the case of an AIDS patient who developed cerebral opportunistic granulomatous lesions and, subsequently, a parkinsonian akinetic-rigid syndrome. In agreement with cases reported in the literature, the parkinsonian syndrome developed only when the lesions bilaterally involved basal ganglia. The critical localization of the opportunistic lesions in the direct and indirect strio-pallidal pathways possibly associated with the HIV-related neurotoxicity might have contributed to determine this clinical picture.

AIDS-Related Opportunistic Infections↗
PubMed2000

Disseminated Mycobacterium terrae infection in a patient with advanced human immunodeficiency virus disease.

Mycobacterium terrae has been rarely implicated in human disease and never in patients infected with human immunodeficiency virus (HIV). We describe an HIV-infected patient with disseminated infection by M. terrae with pulmonary and cutaneous clinical manifestations. M. terrae was isolated from both sputum and urine, and identified by both conventional tests and high-performance liquid chromatography. Clinical and microbiological characteristics of this case are compared with those reported in the literature.

AIDS-Related Opportunistic Infections↗
PubMed1999

The alcohol dehydrogenase gene: distribution among Sulfolobales and regulation in Sulfolobus solfataricus.

The distribution of the alcohol dehydrogenase gene (adh) among different Archaea was investigated by Southern blot analysis revealing the potentiality of the adh gene as a specific marker for the genus Sulfolobus. Moreover, the in vivo expression of the adh gene from a new isolate of Sulfolobus solfataricus, G theta, was studied to investigate gene regulation in Archaea. Primer extension analysis allowed the identification of a single initiation site and the TATA box element. Comparison of the G theta adh promoter with the corresponding Ssadh (adh from S. solfataricus) and RC3adh (adh from Sulfolobus RC3) also revealed the presence of two putative regulatory inverted repeats at the 5' of the TATA element. Northern blot analysis and enzymatic assays demonstrated that the transcription and expression of the G theta adh gene is regulated by different carbon and energy sources or by the natural substrate of the ADH enzyme.

Alcohol Dehydrogenase↗
PubMed1998

Decreasing the stability and changing the substrate specificity of the Bacillus stearothermophilus alcohol dehydrogenase by single amino acid replacements.

The gene encoding the alcohol dehydrogenase (adh-hT) from the thermophilic bacterium Bacillus stearothermophilus LLD-R strain has been overexpressed in Escherichia coli and the corresponding recombinant protein purified to homogeneity. Two putative structural determinants contributing to the higher stability of ADH-hT had been identified by comparison with the less thermostable ADH (ADH-T) from the less thermophilic B. stearothermophilus NCA 1503. In order to ascertain their role, mutations were designed to eliminate in ADH-hT a salt bridge at the N-terminus and a proline residue in the coenzyme binding domain replacing the amino acids located at the same positions in ADH-T. Three mutants--Glu11Lys, Pro242Ala, and Glu11Lys/Pro242Ala--were expressed at high level and the proteins purified and characterized. In general, the mutations had little effect on the activity, indicating that they were not disruptive. The thermal resistance was changed displaying quite additive effects.

Alcohol Dehydrogenase↗
PubMed1996

HCV viraemia is more important than genotype as a predictor of response to interferon in Sicily (southern Italy).

BACKGROUND/AIMS: To investigate host- and virus-related factors predictive of early and sustained alanine aminotransferase normalization after interferon therapy for HCV-related chronic liver disease, in an area where genotype 1 is highly prevalent. METHODS: We studied 100 patients with HCV-RNA positive chronic liver disease (73 chronic hepatitis and 27 cirrhosis) undergoing alpha-interferon treatment. Thirty-four patients had an early response but relapsed, 15 patients remained into sustained response for at least 12 months after therapy, and 51 patients did not respond. Serum HCV-RNA levels were assessed by bDNA (Chiron), and genotype by LiPA (Innogenetics) and by sequencing of the 5' non-coding region. RESULTS: Mean pre-treatment HCV-RNA level (x 10(3) genome equivalents/ml +/- SD) was lower in sustained responders (3854 +/- 7142) than in relapsers (9587 +/- 10163) or in non-responders (5709 +/- 6618). HCV subtype 1b was highly prevalent (82%), while types 1a, 2a, 3 and 4 were rare (about 5% each). However, the prevalence of 1b was much lower (31%) under 40 years of age. The prevalence of subtype 1b among sustained responders (74%) was similar to that observed among relapsers (82%) or non-responders (84%), but some nucleotide substitutions in the putative RNA loop of the 5' non-coding region were seen only among relapsers or non-responders. Multiple logistic regression model showed that early response to interferon was predicted by absence of cirrhosis and a pre-treatment HCV-RNA level below 350. Sustained response to interferon was predicted by pre-treatment HCV-RNA level below 350 and a low fibrosis score. CONCLUSIONS: Among patients with hepatitis C from an area where subtype 1b is highly prevalent, absence of cirrhosis and low pre-treatment serum HCV-RNA level are the most important predictors of response to IFN. Some nucleotide substitutions found in the 5' non-coding region of subtype 1b are associated with non-response or relapse.

Adult↗
PubMed1996

Cloning and overexpression in Escherichia coli of the genes encoding NAD-dependent alcohol dehydrogenase from two Sulfolobus species.

The gene adh encoding a NAD-dependent alcohol dehydrogenase from the novel strain RC3 of Sulfolobus sp. was cloned and sequenced. Both the adh gene from Sulfolobus sp. strain RC3 and the alcohol dehydrogenase gene from Sulfolobus solfataricus (DSM 1617) were expressed at a high level in Escherichia coli, and the recombinant enzymes were purified, characterized, and compared. Only a few amino acid replacements were responsible for the different kinetic and physicochemical features investigated.

Alcohol Dehydrogenase↗
PubMed1996

[Post therapeutic PNX empyema].

Nowadays post-therapeutic PNX empyema represents a rare event because of the discovery of antitubercular drugs. The authors describe one of this cases utilizing the physiopathological theories formulated by Monaldi in 1935. These theories are still both actual and valid.

English Abstract↗
PubMed1995

Hepatitis C virus infection as a determinant of behavior in type 1 autoimmune hepatitis.

To determine if hepatitis C virus infection influences the behavior of type 1 autoimmune hepatitis and to assess the performance parameters of third-generation immunoassays for viral infection in this disease, 64 patients with different patterns of disease behavior were assessed retrospectively for antibodies to hepatitis C virus by third-generation enzyme-linked immunosorbent assay and recombinant immunoblot assay and for HCV RNA by polymerase chain reaction. Hepatitis C virus RNA was detected in seven patients (11%) and antibodies to hepatitis C virus were found in five (8%). All patients who had an acute onset of illness or who sustained remission after therapy lacked HCV RNA in serum. In contrast, four of 31 patients who relapsed (13%) and three of 17 patients who failed treatment (18%) had HCV RNA in serum. Patients with HCV RNA were indistinguishable from those without HCV RNA; in three patients, infection was recognized only by testing for HCV RNA. Four of seven patients with HCV RNA responded fully to corticosteroids, although each relapsed after drug withdrawal. Smooth muscle antibodies (43% versus 91%, P = 0.006) and concurrent smooth muscle and antinuclear antibodies (0% versus 60%, P = 0.003) occurred less frequently in patients with HCV RNA than in counterparts without HCV RNA. The specificity of the third-generation enzyme immunoassay was 98% and its overall predictability was 94%. Its sensitivity, however, was 57% and false positive results occurred in 20%. Hepatitis C virus infection is an uncommon determinant of disease behavior in type 1 autoimmune hepatitis, but it may be present in relapse or treatment failure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Screening for hepatocellular carcinoma in patients with Child's A cirrhosis: an 8-year prospective study by ultrasound and alphafetoprotein.

One hundred and forty-seven patients with Child's A cirrhosis and no evidence of hepatocellular carcinoma were followed up in an 8-year prospective surveillance program with testing by ultrasound and alphafetoprotein every 6 months. Eighteen of 147 patients were HBsAg positive. Anti-hepatitis C virus antibodies were found in 103 out of 133 cases tested. Sixteen patients had a history of heavy drinking. Thirty hepatocellular carcinomas were detected during follow up. At the time of diagnosis, ultrasound detected focal lesions in all the patients whereas alphafetoprotein was below diagnostic levels. The hepatocellular carcinoma was single in 26 patients and multiple in four. The overall 8-year cumulative tumor-free rate was 69% (95% confidence interval = 58-73). The yearly hepatocellular carcinoma incidence from 1985 to 1992 was respectively 2%, 1.5%, 2%, 3%, 5%, 4.8%, 7% and 10%. The initial value of AFP > 50 ng/ml and < 400 ng/ml was significantly related to the development of hepatocellular carcinoma. This series shows that the cumulative incidence of hepatocellular carcinoma in cirrhosis in Italy is higher than previously reported, but lower than that observed in Asiatic areas. A 6-month interval for ultrasound is reasonable to detect treatable tumors. Alphafetoprotein has no value for early diagnosis, although its intermediate values (> 50 and < 400 ng/ml) may indicate the presence of undetectable cancer which will appear during the follow up, and suggests that ultrasound should be employed more frequently in patients with these values.

Aged↗