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Biomedical subjects

A Piana

Publications and source records attributed to A Piana.

At least 19 recordsLinked to original sources
PubMed2003

Periodontal status in an Italian young adult population. Prevalence and relationship with periodontopathic bacteria.

To determine the prevalence of periodontitis in an Italian young adult population and the relationship with Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia in subgingival plaque. A full-mouth periodontal and oral examination was performed in 70 subjects. Dental and behaviour habits were assessed with a standardised questionnaire. Subgingival plaque samples were collected from the deepest pocket of the first molars in each quadrant with a sterile curette. A. actinomycetemcomitans, P. gingivalis and P. intermedia were detected using a multiplex polymerase chain reaction. At subject level, the prevalence of bleeding on probing, calculus, normal pocket depth (PD), PD > 5mm and bacterial positivity were 44.8%, 43.3%, 22.9%, 11.4% and 95.7%, respectively. At quadrant level bacterial prevalence was 79.4%; P. intermedia was the most common bacteria (79.0%); A. actinomycetemcomitans had a prevalence of 40.8%. A significant linear trend across categories of gingival conditions (healthy, bleeding on probing, calculus presence) was detected for P. intermedia (p = 0.0038) and A. actinomycetemcomitans (p = 0.00005) proportions. No significant association was observed between pathogenic bacteria and PD, nor with behavioural attitudes. Gingival conditions are found to be a good predictors (VPP = 85%) for periodontopathic bacteria. For the Italian population, as no data are present, prospective longitudinal studies are needed to examine the relationship between PD and bacteria presence with periodontal disease onset and/or progression.

Actinobacillus Infections↗
PubMed2002

Genotypic characterization of clarithromycin-resistant Helicobacter pylori strains.

UNLABELLED: Helicobacterpylori (Hp) resistance to clarithromycin, one of the antibiotics most used to eradicate infection, is connected with the presence of a point mutation on the level of adenine at position 2143 or 2144 of 23S rRNA. AIM: The aim of the study is to evaluate of the presence of these mutation vs control clarithromycin resistant Hp strains present in North Sardinia; to verify the real association between the type of mutation and the resistance-level; to use easier molecular biology methods to quickly locate the resistance-associated mutations beginning with the bioptic material. The clarithromycin susceptibility of Hp isolates was tested by the E-test method (antibiotic assay). Genomic DNA of Hp strains was amplified using specific primers for the domain V. of ribosomic 23S rRNA and sequenced after the reaction with a primer within the fragment 23S. At the same time PCR-RFLP reliability was examined underlining the presence of these mutations with BsaI, BbsI, MboII restriction enzymes. Two mutations in 2143 (A- - G) and 2144 (A- - G) were found by domain V sequencing. The strains with mutation 2143 are characterized by a greater resistance level (MIC>64 g/ml) than those with mutation 2144 (MIC <64 g/ml). Restriction endonucleases BbsI and MboII recognise the site containing the mutation 2143 (A- - G), while BsaI recognise the mutation 2144 (A- - G). These methods might enable us to identify the presence of Hp directly from bioptic material and possible clarithromycin resistance and plan a suitable therapeutic strategy and consequently a better control of the infection.

Anti-Bacterial Agents↗
PubMed2001

Maximal endothelial tissue plasminogen activator release is not impaired in patients with acute coronary syndromes before heparin treatment.

Procoagulant and fibrinolytic disturbances are described in patients with acute coronary syndromes (ACS), but whether defective maximal tissue plasminogen activator (t-PA) release from the endothelium is also present is still controversial. Previous studies did not take into consideration the contribution of heparin, which strongly affects fibrinolysis. Accordingly, in this study, we measured maximal t-PA release in patients with ACS before, during, and after heparin treatment. Maximal t-PA release was measured by the venous occlusion test in 38 hospitalized patients with confirmed ACS (18 acute myocardial infarctions and 20 unstable anginas) before starting heparin, during heparin treatment, and 4 and 12 h after discontinuation. Plasma plasminogen activator inhibitor type 1 (PAI-1), D-dimer and prothrombin fragment F1 + 2 were also measured. Eighteen age-matched subjects with no evidence of coronary disease were used as controls. At admission, patients showed significantly higher plasma levels of t-PA, PAI-1, and F1 + 2 than controls. Before heparin, maximal t-PA release was similar in patients and controls. Heparin treatment was associated with a significant increase of plasma t-PA, while it did not affect maximal t-PA release. Coagulative and fibrinolytic disturbances are present in patients with ACS, but these do not include maximal t-PA release. Among our patients, maximal t-PA release appears stable over time and is not affected by heparin treatment.

Aged↗
PubMed2001

Rescue of impaired angiogenesis in spontaneously hypertensive rats by intramuscular human tissue kallikrein gene transfer.

Angiogenesis represents a compensatory response targeted to preserve the integrity of tissues subjected to ischemia. The aim of the present study was to examine whether reparative angiogenesis is impaired in spontaneously hypertensive rats (SHR), as a function of progression of hypertension. In addition, the potential of gene therapy with human tissue kallikrein (HK) in revascularization was challenged in SHR and normotensive Wistar-Kyoto rats (WKY) that underwent excision of the left femoral artery. Expression of vascular endothelial growth factor and HK was upregulated in ischemic hindlimb of WKY but not of SHR. Capillary density was increased in ischemic adductor muscle of WKY (from 266+/-20 to 633+/-73 capillaries/mm(2) at 28 days, P<0.001), whereas it remained unchanged in SHR (from 276+/-20 to 354+/-48 capillaries/mm(2), P=NS), thus compromising perfusion recovery as indicated by reduced plantar blood flow ratio (0.61+/-0.08 versus 0.92+/-0.07 in WKY at 28 days, P<0.05). In separate experiments, saline or 5x10(9) pfu adenovirus containing the HK gene (Ad.CMV-cHK) or the beta-galactosidase gene (Ad.CMV-LacZ) was injected intramuscularly at 7 days after the induction of ischemia. Ad.CMV-cHK augmented capillary density and accelerated hemodynamic recovery in both strains, but these effects were more pronounced in SHR (P<0.01). Our results indicate that native angiogenic response to ischemia is impaired in SHR, possibly as a result of defective modulation of endothelial cell mitogens. Supplementation with kallikrein, one of the growth factors found to be deficient in SHR, restores physiological angiogenic response utilitarian for tissue healing. Our discoveries may have important implications in vascular medicine for therapeutic benefit.

Animals↗
PubMed2001

Chlamydia pneumoniae in the cerebrospinal fluid of patients with multiple sclerosis and neurological controls.

Chlamydia pneumoniae infection is a common event in neurological patients and recovery of C. pneumoniae DNA in the cerebrospinal fluids (CSF) of multiple sclerosis (MS) patients could represent an epiphenomenon. We assessed the relevance of C. pneumoniae infection in 62 CSF samples from 32 MS patients and 30 neurological controls by means of PCR, immunofluorescence microscopy, enzyme-linked fluorescence and antibody detection. Multiple sclerosis (9.3%) and neurological controls (13.3) had similar percentage of anti-C. pneumoniae antibodies. However, C. pneumoniae DNA was only detectable in MS patients' CSF (9.3%). Our data support the hypothesis that C. pneumoniae persistence in some MS patients may be the result of an impaired clearance within the central nervous system.

Adult↗
PubMed2001

Clonal relations among Salmonella enteritidis phage type 3 outbreak isolates traced by DNA fingerprinting.

Isolates of Salmonella enteritidis PT3, a rare phage type, were recovered from patients and strains were isolated from an outbreak of gastroenteritis that occurred during the summer of 1997 in North-East Sardinia, Italy. To investigate possible clonal involvement in the outbreak and to evaluate the capacity to discriminate among S. enteritidis PT3 strains, a number of molecular typing methods including ribotyping with a mixture of PstI and SphI (PS-ribotyping), PFGE with endonuclease XbaI and RAPD typing with four arbitrary primers was used. The typical XbaI endonuclease generated PFGE pattern also explained the prevalence of highly clonal S. enteritidis PT3 strains in the outbreak and adjacent areas. RAPD fingerprinting with primers OPA 4, OPB 15, OPB17 and P1254 exhibited a single but unique RAPD profile among the outbreak strains from various sources that differed significantly from control strains. The results of this study showed that when an appropriately chosen set of primers is employed, RAPD fingerprinting can be used as an alternative, rapid, highly reproducible technique for tracing the clonal relations of S. enteritidis PT3, and can be more discriminatory than PFGE. Furthermore, this study revealed the possibility of PT3 causing outbreak.

DNA Fingerprinting↗
PubMed2000

4-Dialkylamino-1-(5-substituted or unsubstituted 1-phenyl-1H-pyrazol-4-yl)butan-1-ols: synthesis and evaluation of analgesic, anti-inflammatory and platelet anti-aggregating activities.

A number of 4-dialkylamino-1-(5-substituted or unsubstituted 1-phenyl-1H-pyrazol-4-yl)butan-1-ols 2a-n were synthesized and tested in vivo for anti-inflammatory and analgesic activities and in vitro for platelet anti-aggregating activity. Dimethylaminoderivatives 2b, e, g showed good analgesic activity; almost all of them had strong platelet anti-aggregating properties at a final concentration of 1 x 10(-3) M; pyrazoles 2c, d, f-h showed weak anti-inflammatory activity.

Analgesics↗
PubMed1999

Pretreatment antibiotic resistance in Helicobacter pylori infection: results of three randomized controlled studies.

BACKGROUND: Although combinations of antibiotics and antisecretory drugs are useful for treatment of Helicobacter pylori infection, treatment failure is common. The aim of this study was to evaluate the relation between pretreatment antibiotic resistance and outcome by using six different treatment regimens for H. pylori infection. PATIENTS AND METHODS: Three hundred sixty-nine consecutive H. pylori-infected patients with dyspeptic symptoms were enrolled in three consecutive randomized, controlled, single-center clinical trials: trial A, 128 patients; trial B, 125 patients; trial C, 116 patients. Treatments consisted of (A) a 15-day course of dual therapy (omeprazole, 20 mg bid, and amoxicillin, 1 gm bid, or clarithromycin, 500 mg tid) (OA vs OC); (B) a 7-day triple therapy of omeprazole, 20 mg bid, plus metronidazole, 500 mg bid, and amoxicillin, 1,000 mg bid, or clarithromycin, 500 mg tid (OMA vs OMC); or (C) omeprazole, 20 mg bid, plus metronidazole, 500 mg bid, plus tetracycline, 500 mg qid, or doxycycline, 100 mg tid (OMT vs OMD). Diagnostic endoscopy was made in all patients before and 5 to 6 weeks after therapy. Six biopsies were taken from each patient for histology, rapid urease test, and H. pylori culture; antibiotic susceptibility testing was performed using the E-test method. RESULTS: Overall cure rates were poor for both dual therapies OA and OC (38% and 37%, respectively) and for triple therapies OMA, OMC, and OMD (57%, 55%, and 58%, respectively). The OMT combination was successful in 91% (95% confidence interval [CI], 80.4%-97%). Metronidazole resistance was present in 29.7% (95% CI, 24%-35%), amoxicillin resistance was present in 26% (95% CI, 21%-32%), clarithromycin resistance was present in 23.1% (95% CI, 18%-29%), tetracycline resistance was present in 14% (95% CI, 10%-20%), and doxycycline resistance was present in 33.3% (95% CI, 21%-47%). Antibiotic resistance markedly reduced the cure rates and accounted for most of the poor results with the triple therapies: 89% versus 23%; 77% versus 26%; 100% versus 60%; and 67% versus 23% for OMC, OMA, OMT, and OMD, respectively. OMT appeared to be the best because of the high success rate with metronidazole-resistant H. pylori (71%) and in low-level tetracycline resistance. CONCLUSIONS: Pretreatment antibiotic-resistant H. pylori can, in part, explain the low cure rate of the infection and the variability in outcome in reported trials.

Amoxicillin↗
PubMed1999

Hemorrhage after an acute ischemic stroke.MAST-I Collaborative Group.

BACKGROUND AND PURPOSE: Hemorrhagic transformation is frequently seen on CT scans obtained in the subacute phase of ischemic stroke. Its prognostic value is controversial. METHODS: We analyzed 554 patients with acute ischemic stroke enrolled in the Multicenter Acute Stroke Trial-Italy (MAST-I) study in whom a second CT scan was performed on day 5. Presence of 1) intraparenchymal hemorrhages (hematoma or hemorrhagic infarction), 2) extraparenchymal bleeding (intraventricular or subarachnoid) and 3) cerebral edema (shift of midline structure, sulcal effacement or ventricular compression) alone or in association were evaluated. Death or disability at 6 months were considered as "unfavorable outcome." RESULTS: Patients who developed intraparenchymal hemorrhages, extraparenchymal bleeding, or cerebral edema had unfavorable outcome (83%, 100%, and 80%, respectively), but multivariate analysis demonstrated that only extraparenchymal bleeding (collinearity) and cerebral edema (OR=6.8; 95% CI, 4.5 to 10.4) were significant independent prognostic findings. Unfavorable outcome correlated with size of intraparenchymal hemorrhage (chi2 for trend=30.5, P<0.0001). Nevertheless, when a large hematoma was present the negative effect was mostly due to concomitant extraparenchymal bleeding (chi2=51.6, P<0.0001), and when hemorrhagic infarction was detected the negative effect was mostly explained by the association with cerebral edema (chi2=36.6, P<0.0001). CONCLUSIONS: Extraparenchymal bleeding and cerebral edema are the main prognostic CT scan findings in the subacute phase of ischemic stroke. Stroke patients with a high risk for developing these 2 types of brain damage should be identified. Measures to prevent and adequately treat their development should be implemented.

Acute Disease↗
PubMed1998

Determination of plasma and serum homocysteine by high-performance liquid chromatography with fluorescence detection.

Determination of homocysteine in plasma or serum is becoming an important diagnostic procedure. Accurate, rapid and low cost methods for measuring homocysteine are therefore required. We have improved an HPLC method and made it suitable for clinical application. The total homocysteine in plasma consists of free homocysteine (i.e., reduced plus oxidized homocysteine in the non-protein fraction of plasma) and protein-bound homocysteine. The method consists of the following steps: reduction of the sample with tri-n-butylphosphine, precipitation of proteins with trichloroacetic acid (10%) and derivatization with ammonium 7-fluorobenzo-2-oxa-1,3-diazole-4-sulfonate. The derivatives are separated by reversed-phase high-performance liquid chromatography followed by fluorescence detection. The concentrations (mean +/- S.D.) of total homocysteine in plasma from 77 normal subjects, 44 male and 33 female adults, were 8.4 +/- 2.15 and 7.1 +/- 1.18 mumol/l, respectively. Serum concentrations were 8.8 +/- 2.6 mumol/l in males and 7.6 +/- 1.5 mumol/l in females.

Chromatography, High Pressure Liquid↗
PubMed1998

Amoxycillin resistance is one reason for failure of amoxycillin-omeprazole treatment of Helicobacter pylori infection.

BACKGROUND: The efficacy of omeprazole and amoxycillin dual therapy to treat Helicobacter pylori infection has been inconsistent, suggesting the presence of host or bacterial factors influencing treatment success. The aim of this study was to assess the role of pre-treatment amoxycillin resistance in the efficacy of omeprazole and amoxycillin dual therapy. METHODS: We studied 43 consecutive dyspeptic patients with H. pylori infection. Pre-treatment H. pylori infection was established by the combination of positive rapid urease test, culture and histology. Amoxycillin susceptibility testing was performed by an Epsilometer test (E-test) method and amoxycillin resistance was defined as minimum inhibitory concentration greater than 8 microg/mL. Patients received 20 mg omeprazole twice daily for 28 days and amoxycillin 1000 mg twice daily for 2 weeks. Adverse effects were documented using a questionnaire. H. pylori status was reassessed 6-8 weeks after the end of treatment by rapid urease testing and histological examination of gastric biopsies. RESULTS: Forty-two dyspeptic patients completed the study, and one patient dropped out. H. pylori infection was cured in 2 3 of 42 patients (55%). The cure rate was higher in patients harbouring amoxycillin-sensitive organisms than in those with resistant strains: 66% (19/29) vs. 31% (4/13), respectively (P = 0.049). No significant differences in cure rates were evident in relation to age, sex, smoking habits or compliance. CONCLUSIONS: The effectiveness of amoxycillin-omeprazole dual therapy was greatly reduced in the presence of pre-treatment amoxycillin-resistant H. pylori. The success rate in patients with amoxycillin-sensitive H. pylori was only 66%, suggesting the presence of additional factors affecting the efficacy of this therapy.

Adult↗
PubMed1997

Hyperactivity and increased hydrogen peroxide formation in platelets of NIDDM patients.

Free radical activity may contribute to atherosclerotic lesions which in diabetic subjects may frequently lead to vascular complications. It is known that oxidative stress is associated to diabetes. Protein glycation and glucose oxidation could be possible source of free radicals. 28 non insulin dependent diabetic subjects (NIDDM) were examined. 20 healthy subjects matched for age, sex and for the presence of hypertension and hyperlipidemia were also studied. Hydrogen peroxide, measured by intracellular levels of the fluorescent 2,7-dichloro-fluorescein (DCF), was considered as indicative parameter of free radical production. The results showed that in resting platelets the basal level of hydrogen peroxide was significantly higher in diabetic subjects than in controls. Moreover, after stimulation with thrombin, collagen, phorbol myristate acetate (PMA) and platelet activating factor (PAF), platelets of diabetic subjects generated significantly higher amounts of hydrogen peroxide than controls. Moreover, platelet aggregation induced by adenosine 5'-diphosphate (ADP) and plasma beta TG levels were higher in diabetics than in controls. In diabetic patients platelet free radical production and functional activity are increased and therefore could play a role in the elevated thrombotic risk described in diabetes.

Adenosine Diphosphate↗
PubMed1997

Reliability of hemorrhagic transformation diagnosis in acute ischemic stroke.

BACKGROUND AND PURPOSE: Diagnosis of hemorrhagic transformation (HT) could influence the prognosis and the management of acute ischemic stroke. The interobserver reliability of CT-scan HT classification is evaluated in the present study. METHODS: Fifty 5-day CT scans of patients enrolled in the Multicenter Acute Stroke Trial-Italy (MAST-I) were reviewed independently by two neuroradiologists and one neurologist with CT training. They evaluated the presence and type of intraparenchymal HT (hemorrhagic infarction types I, II, and III and intracerebral hemorrhage) (five-item scale), as well as the presence of intraventricular and/or subarachnoid bleeding according to standardized definitions. RESULTS: Agreement for exclusion of HT and intraventricular/ subarachnoid bleeding was good between the neuroradiologists (kappa = 0.70 and kappa = 0.72) and excellent between the neurologist and each neuroradiologist (kappa = 0.87 and kappa = 0.77, kappa = 0.83, and kappa = 0.81, respectively). The overall agreement for the five-item HT scale between the two neuroradiologists was good (kappa n = 0.65) because of discordance over the last three items. Better overall agreement was obtained with a three-item scale: no hemorrhage, petechial type I hemorrhagic infarction, and other HT (type II and type III hemorrhagic infarction and intracerebral hemorrhage) together (kappa w = 0.82 CONCLUSIONS: Exclusion of HT is a reliable CT diagnosis when made by neuroradiologists and also by a neurologist with CT training. Five- and three-item scales of HT types showed good to excellent reliability. The validity of the scale for predicting short- and long-term outcome should be evaluated in future studies.

Acute Disease↗
PubMed1992

Increased hydrogen peroxide formation in platelets of patients affected with essential thrombocythaemia (ET).

The basal platelet level of reactive oxygen species and their enhancement following stimulation by different agonists were determined in a selected group of patients with essential thrombocythaemia (ET). Activated platelets had lower levels of superoxide anion and higher intracellular concentrations of hydrogen peroxide than controls. Higher levels of lipid peroxidation induced by N-ethylmaleimide were also observed. Measurement of the most important enzymes generating and scavenging these reactive oxygen species revealed increased specific activities of NADPH-cytochrome c reductase and superoxide dismutase and a decrease in platelet catalase activity in patients with ET. Since an abnormal production of oxygen radicals seems to be implicated in various pathological conditions and aging processes, the increased amount of hydrogen peroxide found in platelets of patients could be involved in some of the platelet alterations described in ET.

Blood Platelets↗