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Biomedical subjects

G Fadda

Publications and source records attributed to G Fadda.

At least 127 records · Page 7Linked to original sources
PubMed1997

Identification of various medically important Candida species in clinical specimens by PCR-restriction enzyme analysis.

A single primer pair amplifying a cytochrome P-450 lanosterol-14 alpha-demethylase (L1A1) gene fragment that encodes a highly conserved region was used to detect yeast DNA in clinical specimens. Positive PCR products were obtained from genomic DNAs of Candida albicans, C. parapsilosis, C. tropicalis, C. guilliermondii, C. krusei, C. (Torulopsis) glabrata, and C. kefyr. No human, bacterial, or parasitic DNA was amplified. The sensitivity was evaluated for C. albicans genomic DNA by using various DNA concentrations (200 pg to 2 fg). The amplified DNAs of Candida species with unknown P-450 L1A1 gene sequences were subcloned and sequenced. Identification at the species level was achieved by digestion of the PCR products with different restriction enzymes. A specific restriction enzyme analysis pattern was determined for each species investigated. Subsequently, we used PCR to detect specific yeast DNA directly with clinical specimens such as blood and bronchoalveolar lavage specimens. After appropriate treatment, the specimens were processed by PCR and the results were compared with those obtained by traditional diagnostic procedures such as cultures and serology. Although preliminary, the PCR results seem to correlate well, at least for blood, with those of antigen detection assays and traditional blood cultures, with a better and earlier detection of candidemia.

AIDS-Related Opportunistic Infections↗
PubMed1997

Detection and typing of herpes simplex viruses by using recombinant immunoglobulin fragments produced in bacteria.

Thirty-seven bacterial clones producing human recombinant monoclonal antibody Fab fragments (rFabs) reactive to herpes simplex virus (HSV) antigens were selected from a human combinatorial antibody library constructed in a phage-display vector by a panning procedure against an HSV lysate. Thirty-four of the HSV-specific rFabs were able to specifically recognize HSV-infected cells in indirect immunofluorescence (IF) assays; of these, 25 recognized cells infected by either HSV type 1 (HSV-1) or HSV-2, while 9 recognized only HSV-1-infected cells. One HSV type-common rFab (rFab H37) and one HSV-1-specific rFab (rFab H85) were further evaluated as reagents for viral detection and typing by IF staining in 134 HSV-positive (72 HSV-1 and 62 HSV-2) viral cultures from clinical specimens. The results obtained with these two rFabs were fully consistent with those obtained with a commercial preparation of fluorescein-labeled anti-HSV type-specific murine monoclonal antibodies. The detection sensitivity with the type-common rFab in indirect IF assays was higher overall than that provided by the type-specific murine monoclonal antibodies. Preparations of rFabs suitable for IF staining can be easily and inexpensively obtained in a clinical microbiology laboratory from Escherichia coli cultures. Similar HSV-specific rFabs, therefore, could be advantageous for in vitro diagnostic purposes.

Animals↗
PubMed1997

Evaluation of a nonradiometric system (BACTEC 9000 MB) for detection of mycobacteria in human clinical samples.

This study was carried out to evaluate the rate of recovery and time required for detection of mycobacteria from pulmonary and extrapulmonary human clinical samples, by using a fluorescence-quenching-based oxygen sensor (BACTEC 9000 MB; Becton Dickinson Microbiology Systems, Sparks, Md.). The results were compared with those obtained by microscopy, conventional culture in Lowenstein-Jensen (LJ) medium, and a BACTEC radiometric system (BACTEC 460 TB; Becton Dickinson). Of the 779 clinical samples processed, 364 from pulmonary sites and 415 from extrapulmonary sites, 62 (7.9%) were positive for mycobacterial isolates; of the positive samples, 59 (95.1%) were detected with the fluorescent BACTEC 9000 MB system, 57 (91.9%) were detected with the radiometric system (BACTEC 460 TB), and 43 (69.3%) were detected with LJ conventional culture. The mean times to detection of all mycobacteria with BACTEC 9000 MB and BACTEC 460 TB were similar (10.3 and 10.0 days, respectively). The results obtained indicate that the nonradiometric BACTEC (BACTEC 9000 MB) system is as efficient as Bactec 460 TB and significantly more efficient than LJ for the rapid recovery of mycobacteria from both pulmonary and extrapulmonary clinical specimens. Though the BACTEC 9000 MB system is recommended for respiratory specimens, we demonstrated that it can be successfully used also for recovery of mycobacteria from clinical specimens from various extrapulmonary sites.

Bacteriological Techniques↗
PubMed1997

Polymerase chain reaction and reverse cross blot hybridization assay for detection of mycobacterial DNA in lupus vulgaris.

For 5 years, an 83-year-old man had been suffering from slightly itchy erythematous plaques with clearcut margins, located on his left thigh and on his right arm; in addition, on his right auricle there was an erythematous patch with yellowish shadings that had appeared about 3 years before and had progressively spread to the temporal-zygomatic region, the chin and the mandibular arch. These lesions were strongly suggestive of lupus vulgaris; however the conventional bacteriological examinations performed on the biopsy specimen from lesional skin were negative. A diagnosis of lupus vulgaris was achieved through the detection of the 16S rRNA gene of Mycobacterium tuberculosis in a skin biopsy of the patient by means of a polymerase chain reaction followed by a reverse cross blot hybridization, a method which allows the identification of different mycobacterial species in a single hybridization procedure.

Aged↗
PubMed1997

Anaplastic progression of classic Kaposi's sarcoma.

We describe a case of classic Kaposi's sarcoma (KS) in an Italian HIV-negative patient, with bone involvement and progression to anaplastic histotype. At the age of 22, violaceous patches of KS appeared on his feet. At the age of 50, he noted the appearance of a violaceous firm nodule on his right wrist. The lesions grew rapidly and became ulcerated. Radiotherapy led to a complete remission of symptoms. At the age of 55, a subcutaneous nodule developed on the proximal third of the right forearm associated with a wide painful edema of the right forearm and the proximal third of the right arm. The nodule enlarged rapidly, and an X-ray of the right forearm revealed the presence of a large osteolytic area of the ulna. A biopsy specimen from the right ulna showed bone erosion by a mesenchymal neoplasia with a high degree of malignancy. The right arm was amputated, and histologic examination of the surgical material confirmed the diagnosis of undifferentiated spindle-cell malignant neoplasia strongly positive for factor-VII-related antigen and CD34 antigen. Three years after surgical treatment, no recurrences have been observed.

Adult↗
PubMed1997

One-tube nested polymerase chain reaction in the diagnosis of Chlamydia trachomatis infections.

A one-tube nested polymerase chain reaction (PCR) using primers derived from the major outer membrane protein gene sequence of Chlamydia trachomatis was compared with McCoy cell culture for the detection of the micro-organism in clinical specimens. Of 110 urogenital and ocular specimens, 21 were positive by culture and 25 by nested PCR; all 21 culture-positive specimens were also positive by nested PCR. After resolution of discrepant specimens as true-positive, sensitivity was 100% for nested PCR and 84% for cell culture, while specificity was 100% for both tests. One-tube nested PCR appears to be a rapid, highly sensitive and specific technique for diagnosing C. trachomatis infections.

Bacterial Outer Membrane Proteins↗
PubMed1996

Choledochocele: changing trends in diagnosis and management.

Eighty-four patients with choledochocele collected from the world literature and one personal observation are reviewed. The main issues regarding clinical presentation, diagnostic work-up, and the treatment of this uncommon lesion are discussed. Abdominal pain was the most common clinical feature (91% of cases), followed by pancreatitis (38%), nausea or vomiting (35%), and jaundice (26%). In addition, associated lithiasis was found in 43% of the cases. Endoscopic retrograde cholangiopancreatography was the most useful diagnostic procedure and resulted in a correct diagnosis in all but one of the patients investigated by this method. Surgical excision of the duodenal luminal portion of the choledochocele was the treatment most commonly used (65% of cases). In recent years, operative endoscopy has also been increasingly used, with good results.

Adolescent↗
PubMed1996

In-vitro activity of 3-azinomethyl-rifamycin (SPA-S-565) against Chlamydia trachomatis.

The in-vitro activity of a 3-azinomethyl-rifamycin (SPA-S-565) against Chlamydia trachomatis was compared to that of rifampicin and of erythromycin. The compound showed excellent activity for standard strains as well as isolates from patients with sexually transmitted diseases, being more active than the other drugs tested. SPA-S-565 also showed a low frequency of emergence of resistance. Passage of standard strains at sub-inhibitory concentrations caused an increase in MIC values of rifampicin while those for SPA-S-565 remained unchanged.

Anti-Bacterial Agents↗
PubMed1996

Molecular epidemiology of Mycobacterium tuberculosis strains isolated from different regions of Italy and Pakistan.

The use of the (GTG)5 oligonucleotide, a repetitive marker in the Mycobacterium tuberculosis chromosome, as a primer in association with an IS6110 outlooking primer has been successfully applied to a PCR-based fingerprinting method. This method classified 62 strains of M. tuberculosis, isolated from human immunodeficiency virus-seropositive and -seronegative patients in different regions of Italy and Pakistan, as having 53 different patterns. The results were compared with traditional IS6110 fingerprinting, by which 47 distinct patterns were observed.

AIDS-Related Opportunistic Infections↗
PubMed1996

Disseminated bone marrow metastases of insular thyroid carcinoma detected by radioiodine whole-body scintigraphy.

We present 131I scintigraphic findings in a patient with insular carcinoma of the thyroid showing diffuse abnormal uptake throughout the skeleton. The scintigraphy closely resembled the pattern of [131I]MIBG distribution in children with bone marrow metastases of neuroblastoma. The extent of involvement was underestimated by bone scintigraphy and radiography. Insular carcinoma of the thyroid in the bone marrow was subsequently demonstrated by biopsy. The patient was treated with 242 mCi 131I given in two courses, which led to severe myelosuppression and died as a result of progressive disease and severe pancytopenia 10 mo after initial therapy.

Biopsy↗
PubMed1995

Prospective study of Yersinia enterocolitica infection in thalassemic patients.

We determined prospectively during a 12-month period the incidence, clinical characteristics and outcome of Yersinia enterocolitica infection in 144 thalassemic patients (mean age, 12.8 years) and compared them with 100 controls (mean age, 12.1 years). Symptomatic Y. enterocolitica infection occurred in 14 (10%) of the thalassemic patients and in 2 (2%) controls (P = 0.017). Of the 14 thalassemic patients 5 (36%) had septicemia and 9 (64%) had focal infection (enteritis in 8 and tonsillitis in 1). One control patient had acute enteritis and the other had tonsillitis. All isolates from these patients belonged to pathogenic phenotypes of Y. enterocolitica. Pending culture results symptomatic thalassemic patients discontinued treatment with deferoxamine and were treated with intravenous antibiotic therapy. Patients with the ultimate diagnosis of focal Y. enterocolitica infection continued treatment with intramuscular ceftriaxone or intravenous trimethoprim/sulfamethoxazole (TMP/SMX) for 7 days, whereas those with septicemia continued treatment with intravenous TMP/SMX for 14 days. The outcome was favorable in all 14 thalassemic patients. We conclude that Y. enterocolitica is a significant cause of morbidity in our patients with thalassemia and that prompt antibiotic therapy might prevent life-threatening conditions as well as a complicated course with long term sequelae.

Adolescent↗
PubMed1995

Susceptibility of Acanthamoeba castellanii to contact lens disinfecting solutions.

A corneal isolate of Acanthamoeba castellanii was exposed to commercial contact lens disinfecting solutions containing hydrogen peroxide, benzalkonium chloride, polyaminopropyl biguanide, polyquaternium 1, and chlorhexidine-thimerosal. The minimum trophozoite amebicidal concentration and exposure times required to kill trophozoites and cysts were determined. Solutions containing hydrogen peroxide or chlorhexidine-thimerosal were active against both trophozoites and cysts. The benzalkonium chloride-based solution was effective only against trophozoites. Solutions containing polyaminopropyl biguanide or polyquaternium 1 were completely ineffective. The need for adequate exposure times must be stressed.

Acanthamoeba↗
PubMed1995

Morphologic and planimetric diagnosis of follicular thyroid lesions on fine needle aspiration cytology.

During 1989-1992, 2,729 fine needle aspiration biopsies were performed; 585 with histologic controls were reviewed. The aim of the study was to demonstrate the incidence of carcinoma in follicular-structured smears without nuclear enlargement, evaluated with planimetric techniques, and to suggest a new cytodiagnostic classification. Of 398 follicular-structured smears, 188 were colloid nodules, 38 were thyreocytic hyperplasias without nuclear atypia, 146 were predominantly follicular lesions (PFL) and 26 were follicular lesions with nuclear pleomorphism. The last showed a high incidence of neoplasia (69.2%) and carcinoma (46.1%) and the largest planimetric values for nuclear area, perimeter and maximum diameter. The second and third categories showed only a difference in the incidence of benign neoplasms (32.9 vs. 15.8%). These results suggest that six months of expectant management might be useful in simple follicular lesions, whereas a follicular pattern with nuclear enlargement requires surgical treatment for the strong possibility of carcinoma.

Adenoma↗