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Biomedical subjects

G Fadda

Publications and source records attributed to G Fadda.

At least 55 records · Page 3Linked to original sources
PubMed2001

Antibacterial activity of ozonized sunflower oil (Oleozon).

AIMS: To evaluate the antimicrobial effect of the ozonized sunflower oil (Oleozon) on different bacterial species isolated from different sites. METHODS AND RESULTS: The effect of Oleozon on Mycobacteria, staphylococci, streptococci, enterococci, Pseudomonas and Escherichia coli was tested. The sunflower oil was ozonized at the Centro de Investigaciones del Ozone (CENIC, Havana, Cuba) by an ozone generator. MICs were determined by the agar dilution method. For Mycobacteria, the MIC of Oleozon was determined on solid medium by a microdrop agar proportion test. Oleozon showed antimicrobial activity against all strains analysed, with an MIC ranging from 1.18 to 9.5 mg ml-1. CONCLUSION: Oleozon showed a valuable antimicrobial activity against all micro-organisms tested. Results suggest that Mycobacteria are more susceptible to Oleozon than the other bacteria tested. SIGNIFICANCE AND IMPACT OF THE STUDY: The wide availability of sunflower oil makes Oleozon a competitive antimicrobial agent. These results should prompt the setting up of some clinical trials to compare Oleozon with other antimicrobial agents.

Bacteria↗
PubMed2001

Abdominal aortic aneurysm in normotensive patients: association with angiotensin-converting enzyme gene polymorphism.

OBJECTIVE AND DESIGN: to assess if deletion of the angiotensin-converting enzyme (ACE) gene is a risk factor for abdominal aortic aneurysms (AAAs) in normotensive patients. MATERIALS AND METHODS: ACE gene polymorphism was examined by polymerase chain reaction in 124 subjects with AAA and in 112 control subjects. AAA normotensive patients (group A, n=56) were compared to normotensive control subjects (group B, n =112) and to AAA hypertensive patients (group C, n =68). All subjects enrolled in this study were Caucasian and from central and southern Italy. RESULTS: the distribution of ACE genotypes was: normotensive patients with AAAs (group A): 3 II, 14 ID, 39 DD; normotensive control subjects (group B): 36 II, 48 ID, 28 DD; hypertensive patients with AAAs (group C): 14 II, 32 ID, 22 DD. The DD genotype was more common in group A than in control groups (A vs B p<0.001; A vs C p <0.001). The ID genotype was more common in group A as well (A vs B p <0.05; A vs C p <0.005). CONCLUSIONS: our data suggest a role for ACE I/D gene polymorphism in the pathogenesis of AAA in normotensive patients.

Aged↗
PubMed2001

Thyroid tumors in children and adolescents: preoperative study.

Several studies indicate that in young patients (less than 21 years of age at the time of diagnosis), the prognosis of thyroid carcinoma (TC) is more favorable than in older patients. However, a more radical treatment approach is recommended in children and adolescents due to the higher prevalence of local lymph-node involvement in these cases. Since the extent of primary surgical treatment is closely related to the overall prognosis, preoperative diagnosis becomes essential in the management of thyroid neoplasms in young patients. In this retrospective study (1987-1998), we analyzed a surgical series of 50 children and adolescents with thyroid nodules in an attempt to establish the role of diagnostic studies in detecting malignant lesions prior to surgery. Our diagnostic protocol for evaluating thyroid nodules was based on clinical evaluation, measurement of thyroid-hormone and thyroglobulin (TG) levels, anti-TG and anti-TPO antibody titers, calcitonin, CEA, and TPA levels, sonography, scintigraphy, and fine-needle aspiration cytology (FNAC) of the thyroid nodules and any enlarged lymph nodes. Eleven of the 15 cases of histologically confirmed carcinoma were preoperatively identified as malignant lesions with the aid of FNAC. The authors conclude that the preoperative work-up of children and adolescents with thyroid nodules requires the collaboration of an experienced team of professionals, and recommend FNAC as the initial test.

Adolescent↗
PubMed2001

Free peritoneal grafts for patch urethroplasty in male rabbits.

PURPOSE: We evaluated the feasibility of urethroplasty using a free peritoneal graft in a rabbit model. MATERIALS AND METHODS: In 12 male rabbits a urethral defect was created by excising a 3 x 5 mm. portion of the ventral urethral surface. The defect was immediately repaired with a free peritoneal graft harvested via a left flank incision. RESULTS: There were 2 intraoperative deaths and 1 death on day 8 postoperatively. These animals were excluded from study. The remaining 1, 4 and 4 rabbits were sacrificed 3, 5 and 9 weeks after surgery, respectively. Macroscopic examination of the urethra revealed no stenosis or diverticula, while a fistula was present in 3 of the 9 animals. Histological study of the fistulous tracts showed chronic granulomatous inflammation. In the remaining 6 rabbits there was graft adherence. The inner surface of the graft was uniformly lined with normal urothelium, while in some cases acute inflammatory cells were present in the subepithelial layer. CONCLUSIONS: Our experience indicates that the ease of harvesting free peritoneal grafts and their satisfactory adherence to the urethra makes them a valid alternative for repairing urethral defects.

Animals↗
PubMed2001

Molecular basis of rifampin and isoniazid resistance in Mycobacterium bovis strains isolated in Sardinia, Italy.

Fourteen of 22 (68%) Mycobacterium bovis strains isolated from cattle in Sardinia were found to be resistant to rifampin and isoniazid. Analysis of the rpoB and the katG, oxyR-ahpC, and inhA gene regions of these strains was performed in order to investigate the molecular basis of rifampin and isoniazid resistance, respectively. The most frequent mutation, encountered in 6 of 10 strains (60%), was in the rpoB gene; it occurred, at codon position 521 and resulted in leucine changed to proline. This suggests that codon 521 may be important for the development of rifampin resistance in M. bovis. Resistance to isoniazid is associated in Mycobacterium tuberculosis with a variety of mutations affecting one or more genes. Our results confirm the difficulty of interpreting the sequence variations observed in clinical strains of M. bovis. M. bovis strains isolated from the same geographic area showed similar mutations within the genes responsible for rifampin and isoniazid resistance. Our results represent the first study to elucidate the molecular genetic basis of drug resistance in M. bovis isolated from cattle.

Animals↗
PubMed2001

Evaluation of BACTEC Mycobacteria Growth Indicator Tube (MGIT 960) automated system for drug susceptibility testing of Mycobacterium tuberculosis.

The reliability of the BACTEC MGIT 960 system, an automated version of the Mycobacteria Growth Indicator Tube (MGIT), for antimicrobial susceptibility testing of Mycobacterium tuberculosis was evaluated on 78 clinical isolates. Rifampin (RMP), isoniazid (INH), streptomycin (SM), and ethambutol (EMB) were tested at the following concentrations: 1.0 microg/ml for RMP, 0.1 and 0.4 microg/ml for INH, 1.0 and 4.0 microg/ml for SM, and 5.0 and 7.5 microg/ml for EMB. Results were compared with those obtained by the BACTEC 460 TB radiometric system. Initially the reproducibility study showed 99.5% agreement on repeat testing with all the four drugs. With susceptibility testing of clinical isolates, excellent agreement between the two systems was found for all the drugs. A total of nine major errors were observed for only three isolates, resistant according to BACTEC MGIT 960 and susceptible according to BACTEC 460 TB, to SM (4.0 microg/ml), INH (0.1 microg/ml), and EMB (5.0 microg/ml) (one isolate) and to SM (1.0 microg/ml), INH (0.4 microg/ml), and EMB (5.0 microg/ml) (two isolates). When these isolates were tested by using the conventional proportion method on Löwenstein-Jensen medium, agreement with BACTEC MGIT 960 was found for five results and with BACTEC 460 TB for the remainder. The time to report results was 7.9 days by MGIT 960 and 7.3 days by BACTEC 460 TB, which was not found statistically significant (P > 0.05). In conclusion, the performance of BACTEC MGIT 960 was found similar to that of BACTEC 460 TB and this new system can be considered a good alternative to the radiometric method for routine susceptibility testing of M. tuberculosis.

Antitubercular Agents↗
PubMed2001

Kaposi's sarcoma associated with previous human herpesvirus 8 infection in kidney transplant recipients.

This study investigates the prevalence of human herpesvirus 8 (HHV-8) infection in kidney transplant patients, evaluating the risk of HHV-8 transmission via transplantation and the association between pre- and posttransplantation HHV-8 infection and the subsequent development of Kaposi's sarcoma (KS). Immunofluorescence and an enzyme immunoassay were used to determine HHV-8 seroprevalence in 175 patients awaiting kidney transplantation and 215 controls who were attending our clinic for other reasons. All patients in the study came from central or southern Italy. Seroprevalence was similar in both groups (14.8 versus 14.9%), with no significant difference between the rates for male and female patients. Of the 175 patients, 100 were tested for anti-HHV-8 antibodies at various times during follow-up. During follow-up, seroprevalence increased from 12% on the date of transplantation to 26%. This increase was paralleled by an age-related increase in seroprevalence in the control group. During follow-up from 3 months to 10 years after transplantation, KS was diagnosed in seven patients (4.0%). Six of these patients were positive for HHV-8 prior to transplantation. Overall, 23.0% of patients who were HHV-8 positive before transplantation developed KS, whereas only 0.7% of seronegative patients developed the disease (relative risk, 34.4; 95% confidence interval, 4.31 to 274.0). This finding suggests that the key risk factor for KS is infection prior to transplantation and that antibody detection in patients awaiting transplantation could be useful in identifying patients at high risk for KS. In patients from geographic areas with a high prevalence of HHV-8, serological tests on donors may be less important.

Adult↗
PubMed2001

Fatal pulmonary infection due to multidrug-resistant Mycobacterium abscessus in a patient with cystic fibrosis.

We report a case of fatal pulmonary infection caused by Mycobacterium abscessus in a young patient with cystic fibrosis, who underwent bipulmonary transplantation after a 1-year history of severe lung disease. Fifteen days after surgery he developed septic fever with progressive deterioration in lung function. M. abscessus, initially isolated from a pleural fluid specimen, was then recovered from repeated blood samples, suggesting a disseminated nature of the mycobacterial disease. Drug susceptibility testing assay, performed on two sequential isolates of the microorganism, showed a pattern of multidrug resistance. Despite aggressive therapy with several antimycobacterial drugs, including clarithromycin, the infection persisted, and the patient died.

Adult↗
PubMed2001

Mapping B-cell epitopes of hepatitis C virus E2 glycoprotein using human monoclonal antibodies from phage display libraries.

Clinical and experimental evidence indicates that the hepatitis C virus (HCV) E2 glycoprotein (HCV/E2) is the most promising candidate for the development of an effective anti-HCV vaccine. Identification of the human epitopes that are conserved among isolates and are able to elicit protective antibodies would constitute a significant step forward. This work describes the mapping of the B-cell epitopes present on the surface of HCV/E2, as recognized by the immune system during infection, by the analysis of the reciprocal interactions of a panel of human recombinant Fabs derived from an HCV-infected patient. Three unrelated epitopes recognized by antibodies with no neutralization-of-binding (NOB) activity were identified; a fourth, major epitope was defined as a clustering of minor epitopes recognized by Fabs endowed with strong NOB activity.

Antibodies, Monoclonal↗
PubMed2001

A multicenter study on central venous catheter-associated infections in Italy.

In a 1-year multicenter study the microbial colonization of 1154 central venous catheters (CVCs) was investigated. Catheters explanted either from immunocompromised or immunocompetent patients were collected and analyzed by five clinical microbiology laboratories located in Ancona, Aviano, Catania, Pavia and Rome, Italy. A further aim was to investigate, by scanning electron microscopy, the features of currently used catheters, both new and explanted from patients, analyzing their surface quality, the influence of the host protein biofilm on their microbial colonization, the modifications caused by their permanence in the body and the relationship between these factors and the occurrence of infections.

Anti-Bacterial Agents↗
PubMed2001

Molecular analysis of Klebsiella pneumoniae strains isolated in pediatric wards by ribotyping, pulsed field gel electrophoresis and antimicrobial susceptibilities.

The purpose of this study was to investigate the usefulness of different molecular typing techniques in the surveillance and control of the spread of extended-spectrum-beta-lactamase-(ESBL) producing Klebsiella pneumoniae in the pediatric department of the "Agostino Gemelli" hospital of the Catholic University in Rome, over a period of nine months. The strains were characterized by ribotyping using HindIII as restriction enzyme and pulsed field gel electrophoresis (PFGE) using XbaI as endonuclease. Sixty six K. pneumoniae clinical strains were isolated during this period, the first 32 were isolated in the summer of 1998. Among these first isolates, ribotyping generated 26 different patterns whereas PFGE produced 16 patterns. The remaining 34 strains were isolated during January and April 1999 and all of them were ESBL producers. Ribotyping clustered the strains into 6 patterns whereas PFGE generated only 3 patterns. PCR revealed the presence in 10 isolates of both bla(TEM) and bla(SHV) genes and 24 strains carried only the bla(SHV) gene. In our experience ribotyping revealed a higher power of differentiation with respect to PFGE and was of great help in the surveillance of the infection.

Cross Infection↗
PubMed2001

Weakly beta-haemolytic human intestinal spirochaetes antagonize the haemolytic activity of Clostridium perfringens alpha-toxin producer.

The production of haemolytic antagonism between weakly beta-haemolytic human intestinal spirochaetes (wbetaHIS) related to human intestinal spirochaetosis and Clostridium perfringens alpha-toxin producer was investigated. A reduction of the clostridial haemolytic activity and a distortion of the haemolytic halo of clostridial alpha-toxin surrounded by a small zone of poorly cooperative haemolysis was clearly observed on the level of the spirochaetal growth area when 40 out of 41 wbetaHIS were cultivated in sheep blood agar plates together with Clostridium perfringens alpha-toxin producer. This phenomenon of haemolytic antagonism was observed only when wbetaHIS grew 72-96 hours sooner than C. perfringens and after the inoculum of the latter at a distance of 0 to 10 mm from wbetaHIS the plates were anaerobically incubated for an additional 48 hours and the bacteria were used at concentrations ranging from 10(7) to 10(4) CFU/ml. These results were also observed between C. perfringens and weakly beta-haemolytic intestinal spirochaetes related to animal intestinal spirochaetosis including avian strains and Brachyspira (Serpulina) pilosicoli of porcine origin.

Animals↗
PubMed2001

Oral neltenexine in patients with obstructive airways diseases: an open, randomised, controlled comparison versus sobrerol.

BACKGROUND: The synthetic mucolytic neltene-xine is an amide derivative of ambroxol and thiophencarboxylic acid. The aim of this open, randomised, controlled study versus sobrerol was to evaluate the efficacy and tolerability of neltenexine (oral granules in sachets) as compared with sobrerol (oral granules in sachets), administered to patients with obstructive airways disease. METHODS: Thirty male and female patients were recruited. The exclusion criteria were allergy to neltenexine or sobrerol, an assessed diagnosis of severe bronchospasm requiring beta2-agonists, corticosteroids or aminophylline, pregnant or nursing women, cystic fibrosis, active tuberculosis or an assessed diagnosis of bronchiectasis. No infections of other organs (such as urinary tract infections) were present at baseline. Concomitant treatment with antitussives or other mucolytic agents was not allowed during the course of the study. Fifteen patients were randomised to treatment with neltenexine, 1 sachet thrice daily for 20 days orally (neltenexine group) and 15 patients to treatment with sobrerol, 1 sachet thrice daily for 20 days orally (sobrerol group). The efficacy parameters were: sputum characteristics and volume, difficulty in expectorating, cough, dyspnoea, pulmonary auscultation. Tolerability was monitored and adverse events were reported. RESULTS: The study highlighted that neltenexine has a good efficacy in the treatment of patients with obstructive airways disease entailing significant impairment of clinical parameters. CONCLUSIONS: Neltenexine can be an effective therapeutic alternative to sobrerol.

Administration, Oral↗
PubMed2001

Follicular adenoma of the thyroid gland with extensive bone metaplasia.

Follicular adenomas of the thyroid account for over 90% of benign neoplasms of the gland. They exhibit a wide range of morphological structures, from the classical follicular pattern to the peculiar hyalinizing trabecular pattern. Although follicular adenomas grow slowly, they are nonetheless subject to degenerative, most often hemorrhagic changes in their central portion. These hemorrhagic areas undergo further regressive changes such as sclerosis and calcification. However, the detection of a true bone formation with a trabecular structure and the presence of marrow is a very rare occurrence. A follicular adenoma with central cartilaginous metaplasia has been reported in literature but, to our knowledge, a follicular adenoma with bone metaplasia has never been described.

Adenoma↗
PubMed2001

Human papillomavirus infection and epidermal growth factor receptor expression in primary laryngeal squamous cell carcinoma.

PURPOSE: This study was designed to add new data about laryngeal carcinogenesis, a multistep process in which chemical and/or viral agents induce and promote successive alterations in growth factor-linked signal transmission pathways, genetic instability, and mutations in key genes involved in cell growth control. Epidemiological evidence suggests that human papillomavirus (HPV) infection may be associated with the development of laryngeal cancer. EXPERIMENTAL DESIGN: In this report, we have analyzed the prevalence of HPV infection and epidermal growth factor receptor (EGFR) expression in a series of 42 laryngeal squamous cell carcinomas by PCR with HPV consensus primers and by a radioligand receptor assay, respectively. RESULTS: HPV DNA was detected in 15 of 42 (35.7%) tumors, and it belonged almost exclusively to the highly oncogenic HPV-16, HPV-18, and HPV-33 genotypes. At analysis by Mann-Whitney nonparametric statistical test, EGFR level was found to be significantly higher in HPV-infected than in HPV-negative cases (T = 440; P = 0.002). EGFR overexpression (EGFR-positive status >6 fmol/mg protein, the arbitrary cutoff value chosen) was found in 20 of 42 (47.6%) tumors, and it was associated with HPV infection in a statistically significant extent (chi(2) = 4.686; P = 0.03). CONCLUSIONS: Viral oncoproteins have been shown to induce a perturbation of the cell response to signals for growth and differentiation; these findings confirm that enhanced EGFR expression and activation in laryngeal squamous cell carcinoma may occur also as a consequence of HPV infection and support the hypothesis of an involvement of HPV infection in laryngeal carcinogenesis.

Carcinoma, Squamous Cell↗
PubMed2001

A novel expression vector for production of epitope-tagged recombinant Fab fragments in bacteria.

Labeling of recombinant Fab molecules is an important yet cumbersome and time-consuming procedure that is needed in many immunological experimental designs. This work describes the development of a novel expression vector fusing to the carboxyterminal of the Fab heavy chain fragments a tag peptide (FLAG) that is consistently recognized by a mouse monoclonal antibody. The presence of the FLAG peptide does not alter the binding characteristics of the unmodified Fab molecule, as demonstrated by relative affinity determinations and competition experiments. This new method is suitable for extensive utilization in immunological experimental work using recombinant Fabs.

Amino Acid Sequence↗