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Biomedical subjects

G Fadda

Publications and source records attributed to G Fadda.

At least 73 records · Page 4Linked to original sources
PubMed2000

Preliminary experiences with contact endoscopy of the larynx.

Nine patients with laryngeal polyps, four with Reinke's edema, three with leukoplakia, one with papilloma and one with malignant tumor were studied by means of laryngeal contact endoscopy during microlaryngoscopy. This technique allowed in vivo and in situ visualization of the superficial layer of the laryngeal epithelium after staining with methylene blue. Cell structures evaluated were the size and color of the nuclei, the nucleus/cytoplasm ratio, nuclear and cytoplasmic contours, the presence of nucleoli, mitoses and keratoses, as well as the microvascular network of the mucosa and superficial cellular changes from normal to pathological. The normal squamous epithelium of the vocal cord showed a homogeneous cellular population with regular nuclear and cytoplasmic morphological characteristics and a uniform nucleus-to-cytoplasm ratio. Specific cellular epithelial patterns and several alterations of the vascular distribution were found in different pathological conditions. Cytological pictures obtained at contact endoscopy were consistent with histological findings in all the patients studied.

Adult↗
PubMed2000

HHV8 in renal transplant recipients.

Human herpevirus 8 (HHV8) DNA sequences have been found in lesions from patients with Kaposi's sarcoma (KS) in several forms including immunosuppressed transplant patients. We wanted to study the transmission of HHV8 in kidney transplant recipients and to assess the risk of development of KS related to the viral infection in this group of patients. We tested sera of 120 renal transplant recipients with serological assay for antibodies to HHV8 antigens before transplantation and then we tested sera of 66 patients of the same group after transplantation. Antibodies were detectable in 27.5% of the patients before transplantation. In the seropositive population 15.1% developed KS and in the negative group 1.1%. Analysing 66 posttransplant sera we noticed that 24% of the seronegative patients became positive after transplantation. Our data suggest that being positive for HHV8 before transplantation could be an important risk factor for the development of KS.

Antibodies, Viral↗
PubMed2000

Proliferating cell nuclear antigen labelling index in localised pigmented villo-nodular synovitis and its relationship to the size of nodules.

Proliferating cell nuclear antigen (PCNA) is one of the cell cycle-related proteins directly involved in DNA synthesis. It is a marker of cellular proliferation and has been shown to correlate with ploidy and proliferative activity of cells. Its expression has been used to estimate the growth fraction of human cancer and its prognostic value. Pigmented villo-nodular synovitis (PVNS) is characterised by a nodular lesion in the paratendinous synovial tissue or, less frequently, in a joint. Whether PVNS is a neoplastic or inflammatory lesion remains controversial. We have studied immunohistochemical PCNA expression with pc10 monoclonal antibody in 16 paraffin sections, in 16 cases of localised PVNS, or giant cell tumour of tendon sheath. We have found significant correlation between the size of the lesions and PCNA-LI (labelling index).

Adolescent↗
PubMed2000

Commercial systems for fluconazole susceptibility testing of yeasts: comparison with the broth microdilution method.

Fluconazole susceptibility was tested in 100 clinical yeast isolates (65 Candida albicans, 13 C. glabrata, 8 C. tropicalis, 7 C. parapsilosis, 3 Saccharomyces cerevisiae, 1 each of C. krusei, C. lusitaniae, Cryptococcus neoformans, Rhodotorula glutinis) and two control strains (Candida krusei ATCC 6258, C. parapsilosis ATCC 22019) using broth microdilution (reference method), disk diffusion, Etest strips, Sensititre YeastOne, Candifast, Integral System Yeasts. Using M27-A breakpoints, isolates were classified as susceptible (81%), susceptible-dose dependent or Resistant with broth dilution. Rates of concordance with the reference method were good for Sensititre YeastOne, Etest and disc-diffusion (81.2%-94.7%) but very low for the Candifast (3.1%) and Integral System (16.6%), which classified most susceptible isolates as resistant. Lack of standardisation (inoculum, medium composition) and non-objective interpretation schemes may be the cause of their poor performance. Sensititre YeastOne, Etest and disc-diffusion are potentially useful for fluconazole antifungal susceptibility testing of yeasts in clinical laboratories.

Antifungal Agents↗
PubMed2000

Efficacy of a multistep strategy for Helicobacter pylori eradication.

BACKGROUND: Helicobacter pylori eradication therapies do not achieve 100% success rates. Antibiotic resistant strains are among the major causes of failure. Current recommendations concerning the management of treatment failures are not fully clear. AIM: To evaluate the efficacy of a multi-step therapeutic strategy in a large group of infected patients. METHODS: A total of 2606 H. pylori-positive patients were administered tinidazole, clarithromycin and a proton pump inhibitor for 1 week. Patients with continuing infection were then given a second 1-week course of amoxycillin, clarithromycin and ranitidine bismuth citrate. Patients still infected after the second course underwent upper gastrointestinal endoscopy with H. pylori culture, and then received a 1-week quadruple proton pump inhibitor-bismuth based scheme established on H. pylori antibiotic sensitivity. RESULTS: After the first step, eradication was achieved in 2063 out of 2413 patients [86% per protocol analysis (PP); 79% intention-to-treat analysis (ITT)]. First-step failures (350 out of 2413; 14.5% PP) showed second-step eradication rates of 82% (271 out of 329 patients, PP; 77% ITT). The specific quadruple therapy for second-step failures (58 out of 329, 18% PP) achieved 77% (30 out of 39 patients, PP) or 52% (ITT) success. This algorithm led to overall eradication rates of 99% (PP) or 91% (ITT). CONCLUSIONS: This multi-step strategy succeeded in a high percentage of H. pylori infected patients. Given the lack of precise guidelines on treatment failures, assessing H. pylori sensitivity to antibiotics only after failure of the second treatment could be suggested in clinical practice.

Algorithms↗
PubMed2000

Distribution of Vibrio cholerae virulence genes among different Vibrio species isolated in Sardinia, Italy.

The members of the genus Vibrio include harmless aquatic strains as well as strains capable of causing epidemics of cholera. Diarrhoea caused by Vibrio cholerae is attributed to cholerae enterotoxin (CT) codified by the ctx operon and regulated by a number of virulence genes such as toxT, toxR and toxS. Fifty-two Vibrio strains were isolated from different aquatic environments in and around Sardinia and searched by PCR for the presence of ctxA, zot, ace, toxR, toxS, toxT, tcpA and vpi virulence genes in the genomes of the isolates. The toxR operon was found in 27 Vibrio alginolyticus strains out of 42 analysed, in three out of four V. cholerae non-O1 strains and in three Vibrio parahaemolyticus isolates. A positive amplification for the virulence pathogenic island (vpi) was produced by five V. alginolyticus strains. Finally, the ace expected amplification fragment was found in two V. alginolyticus isolates whereas the amplification with zot primers produced the expected fragment in one V. alginolyticus isolate. Differentiation of these strains with a PCR fingerprinting technique revealed no association between the presence of virulence genes and a particular fingerprinting pattern. Although most Vibrio species are considered non-pathogenic or only potentially harmful to humans, the finding of V. cholerae virulence genes in other members of the genus Vibrio, and the recent reports of the creation and evolution of pandemic strains of V. cholerae, may give a new perspective to the significance of these results.

DNA Fingerprinting↗
PubMed2000

Brief report: disseminated mycobacteriosis caused by drug-resistant Mycobacterium triplex in a human immunodeficiency virus-infected patient during highly active antiretroviral therapy.

Mycobacterium triplex is a novel species that, until now, has been isolated only from limited clinical samples, and its clinical relevance has been largely unknown. In this report, we describe the first case of disseminated disease caused by M. triplex in a human immunodeficiency virus-infected patient.

AIDS-Related Opportunistic Infections↗
PubMed2000

The arithmetic symmetry of monoatomic 2-nets.

A recent paper [Pitteri & Zanzotto (1998). Acta Cryst. A54, 359-373] has proposed a framework for the study of the 'arithmetic symmetry' of multilattices (discrete triply periodic point sets in the affine space). The classical approach to multilattice symmetry considers the well known 'space groups', that is, the groups of affine isometries leaving a multilattice invariant. The ensuing classification counts 219 affine conjugacy (or isomorphism) classes of space groups in three dimensions, and 17 classes in two dimensions ('plane groups'). The arithmetic criterion gives a finer classification of multilattice symmetry than space (or plane) groups do. This paper is concerned with the systematic investigation of the arithmetic symmetry of multilattices in the simplest nontrivial case, that is, monoatomic 2-nets (planar lattices with two identical atoms in their unit cell). We show the latter to belong to five distinct arithmetic types. We also give the complete description of a fundamental domain for the action of the global symmetry group of 2-nets on the space of 2-net metrics.

Journal Article↗
PubMed2000

Antibodies against human herpesvirus 8 in subjects with non-venereal dermatological conditions.

BACKGROUND: Human herpesvirus 8 (HHV8) is considered as the infectious cofactor involved in the pathogenesis of Kaposi's sarcoma (KS). Its seroprevalence and modes of transmission in the general population are still undetermined. OBJECTIVES: We aimed to estimate the prevalence of HHV8 infection in a population at low risk for sexually transmitted diseases. METHODS: We conducted a seroepidemiological survey on randomly selected individuals attending the dermatology department of a teaching hospital in Rome. Of 257 patients, 248 had their blood analysed for anti-HHV8 antibodies and 201 completed a standardized interview. Serological analysis was performed by an immunofluorescence assay able to detect antilytic antibodies. RESULTS: We found an overall seroprevalence of 15.7% (95% confidence interval, CI 11.4-20.9%), similar in men and women (15.1% vs. 16.3%) and higher at older ages. Seropositivity was not related to sexual habits, while it was significantly associated with a history of hepatitis (seroprevalence 34.6%, adjusted odds ratio, OR 4.08, 95% CI 1.52-11.00) and with a diagnosis of non-melanoma skin cancer (42.9%, OR 4.20, 95% CI 1.26-14.02) or atypical naevi (35.3%, OR 6.21, 95% CI 1.85-20.86). CONCLUSIONS: Our data suggest that a non-sexual mode of transmission of HHV8 infection is plausible in an Italian population at low risk for sexually transmitted diseases and that other factors, besides differences in prevalence of HHV8 infection, may be involved in the epidemiology of classical KS. The unexpectedly high seropositivity rates in subjects with non-melanoma skin cancer and atypical naevi should be viewed with caution and require confirmation.

Adult↗
PubMed2000

Distribution of a specific 500-base-pair fragment in mycobacterium bovis isolates from Sardinian cattle.

Amplification of a specific, 500-bp fragment from Mycobacterium bovis isolates and use of the fragment to differentiate between Mycobacterium tuberculosis and M. bovis was previously reported (J. G. Rodriguez, G. A. Meja, P. Del Portillo, M. E. Patarroyo, and L. A. Murillo, Microbiology 141:2131-2138, 1995). In the present study, 30 M. bovis isolates from Sardinian cattle were examined for the presence of this 500-bp fragment; 4 of the 30 isolates lacked the fragment. This result indicates that identification of M. bovis strains by amplification of the 500-bp sequence may lead to false-negative results.

Animals↗
PubMed2000

Reverse cross blot hybridization assay for rapid detection of PCR-amplified DNA from candida species, Cryptococcus neoformans, and Saccharomyces cerevisiae in clinical samples.

A PCR-based assay was developed to detect and identify medically important yeasts in clinical samples. Using a previously described set of primers (G. Morace et al., J. Clin. Microbiol. 35:667-672, 1997), we amplified a fragment of the ERG11 gene for cytochrome P-450 lanosterol 14alpha-demethylase, a crucial enzyme in the biosynthesis of ergosterol. The PCR product was analyzed in a reverse cross blot hybridization assay with species-specific probes directed to a target region of the ERG11 gene of Candida albicans (pCal), C. guilliermondii (pGui), C. (Torulopsis) glabrata (pGla), C. kefyr (pKef), C. krusei (pKru), C. parapsilosis (pPar), C. tropicalis (pTro), the newly described species C. dubliniensis (pDub), Saccharomyces cerevisiae (pSce), and Cryptococcus neoformans (pCry). The PCR-reverse cross blot hybridization assay correctly identified multiple isolates of each species tested. No cross-hybridization was detected with any other fungal, bacteria, or human DNAs tested. The method was tested against conventional identification on 140 different clinical samples, including blood and cerebrospinal fluid, from patients with suspected fungal infections. The results agreed with those of culture and phenotyping for all but six specimens (two of which grew yeasts not included in the PCR panel of probes and four in which PCR positivity-culture negativity was justified by clinical findings). Species identification time was reduced from a mean of 4 days with conventional identification to 7 h with the molecular method. The PCR-reverse cross blot hybridization assay is a rapid method for the direct detection and identification of yeasts in clinical samples.

Candida↗
PubMed2000

Comparison of the mycobacteria growth indicator tube with radiometric and solid culture for isolation of mycobacteria from clinical specimens and susceptibility testing of Mycobacterium tuberculosis.

We compared the mycobacteria growth indicator tube (MGIT) system with the BACTEC 460 TB and Loewenstein-Jensen (LJ) systems for the recovery of mycobacteria (acid-fast bacilli [AFB]) from 600 clinical specimens. A total of 50 AFB (32 Mycobacterium tuberculosis complex, 10 M. avium complex, 3 M. gordonae, 3 M. xenopi, 1 M. terrae and 1 M. fortuitum) were detected. MGIT recovered 50 isolates of AFB (100% sensitivity), and BACTEC 460 TB and LJ recovered 49 (98% sensitivity) and 19 (38% sensitivity) AFB isolates, respectively. The mean times to detect mycobacteria were 10, 10 and 25 days for MGIT, BACTEC 460, and LJ slants. All isolates of M. tuberculosis complex were tested for susceptibility to streptomycin, isoniazid, rifampin, and ethambutol with the MGIT and BACTEC 460 TB. Both systems yielded identical susceptibility data with different mean times to report (5.38 days for MGIT versus 7.33 days for BACTEC 460 TB, P<0.05). The results suggest that MGIT is equivalent to BACTEC 460 TB in its ability to support the growth of mycobacteria, but significantly more efficient than LJ. MGIT may also be used for susceptibility testing of primary antituberculosis drugs.

Anti-Bacterial Agents↗
PubMed2000

Detection of same sized 4.3 Kb extrachromosomal DNA elements in weakly beta-haemolytic human intestinal spirochaetes and Serpulina pilosicoli of swine origin.

Agarose gel electrophoresis of total DNA from Italian strains of weakly beta-haemolytic human intestinal spirochaetes (w beta HIS) and porcine Serpulina pilosicoli reference strain P43/6/78 showed an extrachromosomal band having the same size and migrating at 4.3 Kb. The same results were observed after agarose gel electrophoresis of DNA obtained from the supernatant fluids of the spirochaetal cultures analysed. Swine Serpulina hyodysenteriae reference strain P18A was comparatively analysed and a 6.5 Kb extrachromosomal DNA element was found, as expected. Furthermore, S. hyodysenteriae reference strain P18A differed from all the other spirochaetes tested and had a higher number of flagella (8-12) at each cell end and was strongly beta-haemolytic. To the best of our knowledge, this is the first report on the detection of a band of extrachromosomal DNA having the same size in w beta HIS and S. pilosicoli from swine origin.

Animals↗
PubMed2000

[Mercury determination in human amniotic fluid].

BACKGROUND: One of the components of Ag amalgam is mercury which, owing to its organic derivatives, can pass into the organs and biological fluids. One particularly interesting but worrying aspect of this transition is the possibility that mercury may pass through the placental barrier and reach the fetus. The aim of this study was to evaluate the concentration of total mercury in human amniotic fluid and compare it with the number and occlusal extension of fillings using Ag amalgam. METHODS: A group of 56 pregnant women were selected due to undergo amniocentesis. A dental check-up was carried out in each patient to identify the number and extension of amalgam fillings. Mercury levels in the amniotic liquid were assayed using a spectrophotometer with atomic absorption and a FIAS-amalgam technique. RESULTS: Mercury concentrations in the samples examined ranged from a minimum of 0.00 ng/ml to a maximum of 2.55 ng/ml, mean 0.44 +/- 0.53 ng/ml. The correlations between the variables examined were evaluated by calculating the coefficient of linear regression. No direct relationship was found with mercury levels. The data obtained were used to construct a model of logistic regression showing scant statistical significance (p = 0.05) between the number of fillings and mercury levels, whereas the occlusal extension of dental repairs was significantly correlated with metal concentrations (p < 0.05). CONCLUSIONS: The authors recommend that silver amalgam should be used with considerable caution during pregnancy.

Adult↗
PubMed2000

Multicenter evaluation of the new HIV DUO assay for simultaneous detection of HIV antibodies and p24 antigen.

A multicenter survey was performed to evaluate a new semi-automated human immunodeficiency virus fourth generation antibodies and antigen simultaneous assay. This assay showed a sensitivity of 100% and specificity of 99.6% among sera obtained from hospitalized patients or blood donors. Sera obtained from commercially available as well as in-house seroconversions were tested showing that HIV DUO is able to reveal an infected state in 11 out of 14 cases earlier than conventional tests. This new assay improves old test performances in terms of sensitivity, maintaining specificity at very high levels.

AIDS Serodiagnosis↗
PubMed1999

Elevated levels of C-reactive protein at discharge in patients with unstable angina predict recurrent instability.

BACKGROUND: In a group of patients admitted for unstable angina, we investigated whether C-reactive protein (CRP) plasma levels remain elevated at discharge and whether persistent elevation is associated with recurrence of instability. METHODS AND RESULTS: We measured plasma levels of CRP, serum amyloid A protein (SAA), fibrinogen, total cholesterol, and Helicobacter pylori and Chlamydia pneumoniae antibody titers in 53 patients admitted to our coronary care unit for Braunwald class IIIB unstable angina. Blood samples were taken on admission, at discharge, and after 3 months. Patients were followed for 1 year. At discharge, CRP was elevated (>3 mg/L) in 49% of patients; of these, 42% had elevated levels on admission and at 3 months. Only 15% of patients with discharge levels of CRP <3 mg/L but 69% of those with elevated CRP (P<0.001) were readmitted because of recurrence of instability or new myocardial infarction. New phases of instability occurred in 13% of patients in the lower tertile of CRP (</=2.5 mg/L), in 42% of those in the intermediate tertile (2.6 to 8.6 mg/L), and in 67% of those in the upper tertile (>/=8.7 mg/L, P<0.001). The prognostic value of SAA was similar to that of CRP; that of fibrinogen was not significant. Chlamydia pneumoniae but not Helicobacter pylori antibody titers significantly correlated with CRP plasma levels. CONCLUSIONS: In unstable angina, CRP may remain elevated for at >/=3 months after the waning of symptoms and is associated with recurrent instability. Elevation of acute-phase reactants in unstable angina could represent a hallmark of subclinical persistent instability or of susceptibility to recurrent instability and, at least in some patients, could be related to chronic Chlamydia pneumoniae infection.

Aged↗