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G Fadda

Publications and source records attributed to G Fadda.

At least 181 records · Page 10Linked to original sources
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An improved phage display vector for antibody repertoire cloning by construction of combinatorial libraries.

Phagemid pComb3 is a widely used vector for molecular cloning of the antibody repertoire and for production of phage display libraries. However, in practical use, the utilization of this vector has some drawbacks. In this work we describe the construction of pComb3/TIG, an improved, easily manipulated vector for the cloning and display of antibody fragment libraries on the surface of filamentous phage. The two small "stuffer" fragments at the cloning sites were replaced with long DNA fragments, for easier differentiation of the correctly cut forms of the vector. Moreover, in pComb3/TIG the fragment at the heavy-chain-fragment cloning site contains an acid phosphatase-encoding gene. This feature allows the easy distinction of the Escherichia coli cells containing the unmodified form of the phagemid instead of the heavy-chain fragment coding cDNA in a simple plate histochemical assay.

Antibodies↗
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Human monoclonal recombinant Fabs specific for HCV antigens obtained by repertoire cloning in phage display combinatorial vectors.

Molecular cloning of the antibody repertoire in phage display combinatorial vectors is a powerful method enabling the dissection of the immunoresponse against a given pathogen. In this paper we describe the construction of a combinatorial library displayed on phage surface, containing the antibody repertoire of a patient with high serological response against hepatitis C virus (HCV) antigens. Following selection of the library against solid-phase-bound antigen, sixteen human antibody Fab fragments able to bind to HCV-specific antigens were generated and studied for binding characteristics. The majority of them appeared to have specificity for the HCV c33 peptide. All the clones reacting with the c33 peptide shared the same heavy-chain CDR3 sequence. This is the first report of molecular cloning in a combinatorial phage display vector of the antibody repertoire of an anti-HCV-positive patient.

Amino Acid Sequence↗
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Probing the natural antibody repertoire by combinatorial cloning of IgM and IgD isotypes in phage display vectors.

It is well known that immunoglobulins with no identifiable immunogenic origin, called natural antibodies, are present in the sera of healthy individuals and their role as a defence against important pathogens has been proposed. Unfortunately, the studies are hampered by the fact that these immunoglobulins seem to have low affinity and to be polyreactive, and are commonly available in polyclonal preparations. Lately, new technologies for the production of monoclonal antibodies became available, and in particular the cloning of genes coding for antibody fragments in combinatorial phage display vectors provided a handy tool for the selection of human monoclonal antibodies. In this work, we describe the successful development of a technology for the molecular cloning of combinatorial phage display libraries containing genes coding exclusively for antibody fragment of the IgM or IgD phenotype. These libraries can be useful for molecular cloning of monoclonal antibodies of the IgM and IgD phenotype and can help elucidate the role played by natural antibodies in defence against infectious agents.

Antibodies, Monoclonal↗
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A new subtraction technique for molecular cloning of rare antiviral antibody specificities from phage display libraries.

The preparation of random combinatorial libraries exposed on the surface of phage provides a route for the selection of diverse high affinity human monoclonal antibodies. However, in particular settings, the isolation of genes coding for a rare antibody can be elusive because some epitopes are predominant and because, in the case of impure antigens, the protein or any compound of interest can be present in relatively minimal amount. In this paper, we describe the successful utilization of a new strategy of "preadsorption" panning that allowed us to clone a rare human monoclonal antibody fragment and to access a different antibody repertoire. The procedure is easy, fast, inexpensive, can be used together with other panning techniques and can be particularly useful in cloning antibodies against rare or unknown determinants.

Antibodies, Monoclonal↗
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Fine needle aspiration of a warthin-like thyroid tumor. Report of a case with differential diagnostic criteria vs. other lymphocyte-rich thyroid lesions.

BACKGROUND: Warthin-like papillary carcinoma of the thyroid (WLT), a recently described entity, should be included among lymphocyterich lesions of the thyroid. The diffuse sclerosing variant of papillary carcinoma (DSV), the oxyphilic variant of Hashimoto thyroiditis (OHT) and primary lymphoplasmacytic lymphoma (PLT), the FNA appearances of which have many similarities, belong to the same category. CASE REPORT: A case of WLT occurred in a 31-year-old female, who was admitted with a 1.5-cm, nodular lesion of the thyroid; fine needle aspiration (FNA) yielded a diagnosis of papillary carcinoma. Histologic examination revealed the characteristic picture of WLT, with papillae lined with large, oxyphilic thyreocytes, with nuclear pseudoinclusions and grooves filled with lymphocytes, mostly mature plasma cells. The FNA picture of WLT was compared with those of the other lymphocyticrich lesions of the thyroid--DSV, OHT and PLT. CONCLUSION: The differences between these forms provide diagnostic criteria that could be useful for the preoperative management of patients affected by suspicious, inflammation like thyroid lesions.

Adult↗
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[Significance of mycoplasma species in the respiratory tract (author's transl)].

After consideration of the tassonomic and biological characteristics of Mycoplasma species, the Author discusses the most significant aspects on M. pneumoniae infections. On the basis of: natural history of respiratory infections; epidemiology; experimental aspects of M. pneumoniae infection; immunology; microbiological and serological diagnosis.

Antibodies, Bacterial↗
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[Preoperative radiochemotherapy in pancreatic cancer: preliminary results].

AIMS AND BACKGROUND: The prognosis of pancreatic cancer remains poor. Surgery, when feasible, is rarely curative. Radiation therapy (RT) and concomitant 5-fluorouracil (5-FU) have been shown to improve survival in locally advanced pancreatic cancer. In an attempt to improve resectability and disease control, we used preoperative chemoradiation in a combined modality therapy protocol. The purpose of this study was to evaluate our initial results in terms of acute toxicity and response. METHODS: From October 1995 to May 1998, 20 patients (11 males, 9 females; mean age, 60.1 years; median follow-up, 28 months) with unresectable (12 patients) or resectable (8 patients) non-metastatic pancreatic tumors, received external beam radiation (39.6 Gy) plus 5-FU (96 hours continuous infusion, days 1-4 at 1000 mg/m2/day). After 4 weeks, patients were evaluated for surgical resection. In resected patients, electron-beam intraoperative radiation therapy (10 Gy) was given before reconstruction. Thereafter, in resected patients, adjuvant chemotherapy was prescribed (6 courses: 5-FU, mitomycin C, adriamicine). RESULTS: During chemoradiation, no patients developed grade 3-4 acute toxicity. Three out of twelve (25%) patients with unresectable tumors had tumor downstaging. No patients showed partial or complete responses. Four out of twenty patients (20%) had minimal tumor response. Three patients showed disease progression after chemoradiation (liver or peritoneal metastases). Nine patients underwent surgical resection and IORT, with 1 postoperative death. The median survival time for the 20 patients was 9.4 (18.5 and 8.3 months in resected and unresected patients, respectively). CONCLUSION: Our preliminary results suggest that preoperative 5-FU chemoradiation was well tolerated and may result in tumor downstaging but the response-rate is still low. Based on the impact of surgical resection on survival, an improvement in local response rate is necessary.

Actuarial Analysis↗
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Histology and aspiration cytology of benign thyroid diseases.

The thyroid is an endocrine gland involved in the homeostatic regulation of the organism by means of its products, the hormones thyroxine (T4) and triiodothyronine (T3). Its basic morphologic unit is the follicle, composed of thyrocytes producing the inactive hormonal form thyroglobulin which is stored in the center of the follicle. The diseases affecting the thyroid are classified into benign and malignant. Benign diseases include goiter, either diffuse (Graves' disease when hyperfunctioning) or nodular (nodular hyperplastic goiter), thyroiditis (including Hashimoto's autoimmune form) and benign neoplasms (adenomas). All benign thyroid diseases can be investigated preoperatively with a fine-needle aspiration biopsy. This technique is simple and safe and allows an accurate cytological diagnosis of these benign lesions.

Adenoma↗
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Virulence factors in Vibrio alginolyticus strains isolated from aquatic environments.

In a microbiological monitoring carried out in various aquatic environment of Sardinia Island (Italy) Vibrio alginolyticus with different virulence phenotypes appeared widely spread. Hemolysis, hemoagglutination and protease production might be together particularly in strains isolated from polluted environments. Adherence capacities to two epithelial cells (Hep-2 and Caco-2) available in laboratory were widely spread in the examined bacterial strains. The adhesion degree was influenced by the utilized cellular clone. The lack of a correspondence between adhesion capacity and more traditional virulence tests do not permit its replacement at screening level.

Adenocarcinoma↗
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Histology and fine-needle aspiration cytology of malignant thyroid neoplasms.

Malignant neoplasms of the thyroid are relatively infrequent tumors which present, like most pathological processes of this gland, as nodules. The commonest types are carcinomas, divided into papillary, follicular, medullary, insular and anaplastic carcinoma. Much less frequent are lymphomas and other non-epithelial malignancies. The fine-needle aspiration biopsy (F.N.A.B.) is the first choice method to investigate nodular thyroid lesions and to detect malignant tumors.

Biopsy, Needle↗
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Prognostic factors in well-differentiated thyroid cancer.

The differentiated thyroid carcinomas are malignant neoplasms most of them following an indolent course with infrequent metastases and long survival. However, a few cases behave in an aggressive fashion and, despite every attempt to treat, cause the death of the patient. Numerous investigations have been carried out to define the markers which affect the prognostic course of these tumors. There are three types of prognostic markers: clinicopathological, pathological (morphological) and biological. The first group include: age, sex, size of the tumor, multifocality, vascular and extrathyroidal invasion, grading and metastases. The second category collects some morphological features like tumor subtype, association with autoimmune thyroid diseases and ploidy. The last group features the oncogenes (RET and RET/PTC rearrangements). The accurate evaluation of all the previous prognostic markers is the basis of the treatment schemes discussed in the last section.

Biomarkers, Tumor↗
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1,2,3-triazolo[4,5-h]quinolines. III. Preparation and antimicrobial evaluation of 4-ethyl-4,7-dihydro-1(2)-R-1(2)H triazolo[4,5-h]quinolin-7-one-6-carboxylic acids as anti-infectives of the urinary tract.

Some 4-ethyl-1(2)-R-1(2)H-4,7-dihydro-triazolo[4,5-h]-quinolin-7-one-6- carboxylic acids were prepared as novel analogues of oxolinic acid, in order to discover the influence of the annelation position of the triazole ring on the antimicrobial activity that, in some isomers triazolo[4,5-f]quinoline carboxylic acids, is selective against Escherichia coli. Some interesting side reactions in the cyclization of 1(2)-R-1(2)H-benzotriazol-4-yl-aminomethylenemalonate are also described. The biological results indicate that this type of annelation is not profitable for antimicrobial activity.

Anti-Infective Agents, Urinary↗
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[Immunohistochemistry in cytologic diagnosis using fine needle aspiration].

The role of immunocytochemistry in fine-needle aspiration cytology. The Authors review the literature about fine-needle aspiration biopsy cytology in different organs and show the feasibility of the application to cytological specimen of immunocytochemical methods. Thus, they analyze 15 cases of tumors of various localization diagnosed by F.N.A.C. where immunocytochemistry succeeded in their correct typization. They also show the encouraging results of the immunocytochemical search of specific hormones in pituitary adenomas. Therefore the Authors emphasize the great usefulness of immunocytochemical techniques for the improvement of the diagnostic possibilities in the fine-needle aspiration cytology.

Adolescent↗
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[Preoperative cytologic diagnosis of medullary carcinoma of the thyroid].

The Authors emphasize the importance of preoperative aspiration cytology in the diagnosis of 5 medullary types out of 58 thyroid carcinomas observed in the Institute of Pathology of the Università Cattolica del S. Cuore of Rome in the period 1983-88. All the cases were diagnosed preoperatively by mean of a fine-needle aspiration cytological specimen; the case where morphological diagnosis was doubtful were studied with immunohistochemical techniques for calcitonin and CEA. Out of all cases, they report one case of multiple endocrine adenomatosis type II with medullary thyroid carcinoma and pheochromocytoma and another one with cervical node metastases without a clinically detectable thyroid swelling. Therefore, the authors propose the fine-needle aspiration cytology as a simple and important mean in the preoperative diagnostic procedure in case of medullary thyroid carcinoma.

Adrenal Gland Neoplasms↗