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Biomedical subjects

A Taddei

Publications and source records attributed to A Taddei.

At least 19 recordsLinked to original sources

Advanced thyroid carcinoma: an experience of 385 cases.

AIMS: To report clinical outcomes of a large series of cases with advanced thyroid cancer. STUDY DESIGN: Three hundred and eighty-five patients at the UICC stages III and IV were selected for the study with thyroid cancer. RESULTS: Papillary carcinoma and sclerosing carcinoma have better survival than the Hürthle cell and insular types. Lymphatic metastasis does not appear to worsen the prognosis. All the tumour forms offer the chance of long survival. CONCLUSIONS: Surgical treatment is the primary treatment of thyroid carcinoma. The combined treatments of surgery, metabolic beam therapy, suppressive hormone therapy, radiotherapy and chemotherapy cure a high percentage of patients with the tumour at an advanced stage.

Adenocarcinoma↗

Photosensitizing properties of 6-methoxy-2-naphthylacetic acid, the major metabolite of the phototoxic non-steroidal anti-inflammatory and analgesic drug nabumetone.

The photobiological properties of 6-methoxy-2-naphthylacetic acid (6-MNAA) were studied using a variety of in vitro phototoxicity assays: photohemolysis, photoperoxidation of linoleic acid, photosensitized degradation of histidine and thymine and the Candida phototoxicity test. 6-MNAA was phototoxic in vitro. 6-MNAA reduced nitro blue tetrazolium (NBT) when irradiated with lambda > or = 300 nm in deoxygenated aqueous buffer solution (pH 7.4). NBT can be reduced by reaction with the excited state of 6-MNAA subject to interference with molecular oxygen. The photohemolysis rate was inhibited by the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO), sodium azide (NaN3) and reduced glutathione (GSH). Photoperoxidation of linoleic acid and photosensitized degradation of histidine and thymine were significantly inhibited by sodium azide and reduced glutathione. 6-MNAA was phototoxic to C. albicans, C. lipolytica and C. tropicalis. A mechanism involving singlet oxygen, radicals, and electron transfer reactions is suggested for the observed phototoxicity.

Aerobiosis↗

Expression of inducible nitric oxide synthase and cyclooxygenase-2 in ovarian cancer: correlation with clinical outcome.

OBJECTIVES: Cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) play a critical role in cancer development. We investigated iNOS and COX-2 expression in relation to clinical outcome in 78 International Federation of Gynecology and Obstetrics (FIGO) stage III ovarian serous carcinoma with a low grade of differentiation (G3). METHODS: Disease-free interval and cause-specific survival rates (Kaplan-Meier method) were compared using the log rank test. A multivariate analysis (Cox-proportional hazards models) was used to determine the independent effect of each variable on prognosis. Fisher's exact test was used to analyze the distribution of iNOS and COX-2 expression according to clinical complete response to chemotherapy and to the presence of a brief disease-free interval (< or =12 months). RESULTS: Overall 60 and 125 months cause-specific survival rates were 32% and 11%, respectively. In univariate analysis, iNOS (P=0.005 and P=0.003, respectively), COX-2 (P=0.002 and P=0.007, respectively), residual disease after surgery (P=0.017 and P=0.032, respectively), and FIGO stage (P=0.008 and P=0.025, respectively) were associated with survival and a disease-free interval. In multivariate analysis (Cox proportional hazards models), the factors that were found to be significantly independent predictors of disease relapse as well as survival were iNOS (P=0.014 and P=0.001, respectively), COX-2 expression (P=0.007 and P=0.029, respectively), and FIGO stage (P=0.026 and P=0.05, respectively). iNOS and COX-2 expressions were correlated with a brief disease-free interval (P=0.001) and clinical complete response to first-line chemotherapy (P=0.038 and P=0.033, respectively). CONCLUSIONS: The evaluation of iNOS and COX-2 expression may give additional prognostic information concerning the clinical outcome of patients with ovarian carcinoma and may encourage them to select more tailored therapies.

Adult↗

c-KIT expression and correlation with chemotherapy resistance in ovarian carcinoma: an immunocytochemical study.

BACKGROUND: Recent studies have shown that several tumours express c-KIT, a growth factor receptor with tyrosine kinase activity; moreover, clinical results have shown the efficacy of the tyrosine kinase inhibitor, STI571, in c-KIT-positive tumours. The aim of this study was to determine the incidence and correlation with chemotherapy resistance of c-KIT expression in advanced serous, low grade of differentiation, ovarian carcinoma. PATIENTS AND METHODS: We performed an immunohistochemistry analysis of 56 patients with advanced serous ovarian carcinomas using archival paraffin-embedded specimens. RESULTS: Intense c-KIT immunostaining was observed in 51.7% of cases. c-KIT expression was statistically correlated with progression of disease after first-line chemotherapy (P = 0.029). CONCLUSIONS: c-KIT is also expressed in ovarian carcinoma and it is statistically correlated with chemotherapy resistance. This study suggests the necessity for clinical trials confirming the utility of the tyrosine kinase inhibitor, STI571, in ovarian advanced cancer patients with c-KIT overexpression when these patients have shown no clinical response to conventional chemotherapy.

Drug Resistance, Neoplasm↗

[BCL-2 in primary central nervous system lymphomas. Immunohistochemistry and molecular biology].

BCL-2 is a membrane protein known to be an apoptosis inhibitor. It is the product of the bcl-2 gene located on chromosome 18. Several different tumors show BCL-2 over-expression as result of a translocation or independently from it. More than 85% of follicular lymphomas and a smaller number of diffuse large cell B lymphomas contain t(14;18) (q32;q21). The aim of this study was to investigate the immunohistochemical expression of the BCL-2 protein and to ascertain, by means of traditional PCR (Polimerase Chain Reaction), its possible dependence from t(14;18) (q32;q21) in 9 primary central nervous system lymphomas. Six cases (67%) shoved immunohistochemical BCL-2 over-expression and 3 cases (33%) had t(14;18). Precisely: 2 cases (22%) had immunohistochemical BCL-2 over-expression and t(14;18) (q32;q21); 4 cases (44%) had BCL-2 over-expression without translocation; 1 case (11%) did not show diffuse BCL-2 over-expression in presence of the traslocation; the remaining 2 cases (22%) did not demonstrate BCL-2 over-expression or t(14;18) (q32;q21). In conclusion, our results indicate primary central nervous system lymphomas frequently show BCL-2 over-expression that in some case may be related to t(14;18) (q32;q21). Nevertheless, t(14;18) (q32;q21), as evaluated by traditional PCR, may not correspond to diffuse immunohistochemical BCL-2 positivity.

Adult↗

Long-term ST database: a reference for the development and evaluation of automated ischaemia detectors and for the study of the dynamics of myocardial ischaemia.

The long-term ST database is the result of a multinational research effort. The goal was to develop a challenging and realistic research resource for development and evaluation of automated systems to detect transient ST segment changes in electrocardiograms and for supporting basic research into the mechanisms and dynamics of transient myocardial ischaemia. Twenty-four hour ambulatory ECG records were selected from routine clinical practice settings in the USA and Europe, between 1994 and 2000, on the basis of occurrence of ischaemic and non-ischaemic ST segment changes. Human expert annotators used newly developed annotation protocols and a specially developed interactive graphic editor tool (SEMIA) that supported paperless editing of annotations and facilitated international co-operation via the Internet. The database contains 86 two- and three-channel 24 h annotated ambulatory records from 80 patients and is stored on DVD-ROMs. The database annotation files contain ST segment annotations of transient ischaemic (1155) and heart-rate related ST episodes and annotations of non-ischaemic ST segment events related to postural changes and conduction abnormalities. The database is intended to complement the European Society of Cardiology ST-T database and the MIT-BIH and AHA arrhythmia databases. It provides a comprehensive representation of 'real-world' data, with numerous examples of transient ischaemic and non-ischaemic ST segment changes, arrhythmias, conduction abnormalities, axis shifts, noise and artifacts.

Adult↗

C-kit expression in uterine leiomyosarcomas: an immunocytochemical study of 29 cases of malignant smooth muscle tumors of the uterus.

Uterine malignant stromal tumors are rare neoplasms characterized by fatal prognosis. At the moment no effective systemic treatment is available for metastases or recurrent disease. The drugs employed in advanced neoplasms are iposfamide, doxorubicin or epidoxorubicin, but the clinical response to chemotherapy is poor. Recent studies have shown that cells in gastrointestinal stromal tumors express a growth factor receptor with tyrosine kinase activity termed c-kit. Lately reports of efficacy of a specific anticancer drug with imatinib (ST1571) based on specific molecular abnormalities of proto-oncogene c-kit present in gastrointestinal stromal tumors induced us to identify the c-kit phenotype also in uterine leiomyosarcomas. These data may be useful for treating metastatic uterine leiomyosarcomas with increased c-kit kinase activity.

Adult↗

Estrogen and progesterone receptors expression in uterine malignant smooth muscle tumors: correlation with clinical outcome.

Uterine leiomyosarcomas are associated with a poor prognosis, although a considerable diversity in behavior may be found, and prolonged survival may occur. The aim of this study was to analyze the expression of estrogen (ER) and progesterone (PR) receptors in tumor specimens from uterine leiomyosarcomas, and to test their correlation with disease-free interval and cause-specific survival. This additional information may help the clinician differentiate between patients who have minimal risk of recurrence and those at greater risk of developing progressive disease. We examined specimens from 31 uterine leiomyosarcoma patients with clinical history and known follow-up. Disease-free interval and cause-specific survival rates were calculated according to the Kaplan-Meier method. According to univariate analysis, with Cox proportional hazards models, the ER expression (P=0.006 and P=0.016, respectively), PR expression (P=0.005 and P=0.016, respectively), and FIGO stage disease (P=0.011 and P=0.007, respectively) were independent predictors of the risk of recurrence and death from disease.

Adult↗

[Atypical, aplastic, and unusual meningiomas. Morphology and incidence in 300 consecutive cases].

We morphologically studied 300 consecutive and primitive meningiomas surgically treated between march 1997 and april 2002 in order to evaluate the incidence of atypical, anaplastic, and morphologically unusual meningiomas. Two hundred and fifty-five meningiomas (85%) were WHO I, 33 (11%) were WHO II, 9 (3%) were WHO III; the remaining 3 meningiomas (1%) showed clear and diffuse oncocytic differentiation without cytologic or architectural atypia (oncocytic meningiomas). Forty-five of 255 WHO I meningiomas (18%) were infrequent histological subtypes: 18 (7%) psammomatous, 9 (4%) metaplastic, 9 (4%) secretory, 6 (2%) angiomatous, and 3 (1%) microcystic. Thirty of 33 WHO II meningiomas (91%) were atypical, 2 (6%) were clear cell meningiomas, and 1 (3%) was chordoid meningioma. Seven of 9 WHO III meningiomas (78%) were anaplastic and 2 (22%) were papillary. We evidenced the high morphological variability and the discrete occurrence of WHO I and WHO II meningiomas.

Humans↗

Multidrug resistance in ovarian cancer: comparing an immunocytochemical study and ATP-tumor chemosensitivity assay.

The aim of our study was to evaluate the possible prognostic and predictive significance of the expression of P-glycoprotein, a transmembrane transport protein related to multidrug resistance, in previously untreated patients with FIGO stage III ovarian cancer; to compare the results of immunocytochemical analysis of tissue sections of tumors to the in vitro chemosensitivity to cytotoxic drug of fresh samples of the same tumors; and to evaluate survival in women who underwent the same surgical treatment and the same adjuvant chemotherapy.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

[Estrogen and progesterone receptors in meningiomas: immunohistochemical (Mib-1, p53) and clinico-morphological correlations].

We studied 98 meningiomas including 89 benign, 5 atypical, and 4 anaplastic tumors to determine the immunohistochemical expression of estrogen and progesterone receptors and its prognostic value in comparison to histological grade, Mib-1 and p53. Estrogen and progesterone receptor positivity was observed in 63% and 5% of the cases, respectively. In 79% of meningiomas only a minimal proliferative activity was documented, whereas in 36% we detected an overexpression of the p53 oncoprotein. Anaplastic meningiomas were constantly negative for PgR, ER, and highly positive for Mib-1; 75% were positive for p53. A statistical correlation was demonstrated between p53 protein and Mib-1. Specifically the p53-negative meningiomas were frequently negative for Mib-1 (p = 0.002); conversely the lesions strongly positive for Mib-1 were p53-positive (p = 0.001).

Adult↗

From snapshots to moving pictures: new perspectives on nuclear organization.

The positioning of chromosomal domains in the interphase nucleus is proposed to facilitate gene regulation in simple cells such as yeasts and to coordinate patterns of gene expression and activation of origins of replication during cell differentiation in complex organisms. Over the past 10-12 years, detailed information on the organization of interphase chromosomes has accumulated from three-dimensional microscopy of fixed cells labeled by in situ hybridization and immunofluorescence techniques. Recently, time-lapse fluorescence microscopy of GFP-tagged domains has shown that interphase chromatin can be highly dynamic, moving distances >0.5 microm within seconds. Novel fluorescence techniques show that most nuclear proteins are also highly mobile. Both the rapid oscillations of chromatin and long-range movements of chromosomes suggest new mechanisms for spatial and temporal control of transcription and other nuclear events.

Animals↗

Reversible disruption of pericentric heterochromatin and centromere function by inhibiting deacetylases.

Histone modifications might act to mark and maintain functional chromatin domains during both interphase and mitosis. Here we show that pericentric heterochromatin in mammalian cells is specifically responsive to prolonged treatment with deacetylase inhibitors. These defined regions relocate at the nuclear periphery and lose their properties of retaining HP1 (heterochromatin protein 1) proteins. Subsequent defects in chromosome segregation arise in mitosis. All these changes can reverse rapidly after drug removal. Our data point to a crucial role of histone underacetylation within pericentric heterochromatin regions for their association with HP1 proteins, their nuclear compartmentalization and their contribution to centromere function.

Animals↗

Bioactivity studies of extracts from Tridax procumbens.

An updated review on the biological activity of Tridax procumbens is presented. A detailed biological screening comprised of gram-positive and gram-negative bacteria, yeasts and fungi using crude extracts of this plant was undertaken. The n-hexane extract of the flowers showed activity against Escherichia coli. The same extract of the whole aerial parts was active against Mycobacterium smegmatis, Escherichia coli, Salmonella group C and Salmonella paratyphi. The ethyl-acetate extract of the flowers was active against Bacillus cereus and Klebsiella sp. The aerial parts extract also showed activity only against Mycobacterium smegmatis and Staphylococcus aureus, while the aqueous extract showed no antimicrobial activity. None of the tested extracts was active against the yeasts, Candida albicans, Candida tropicalis and Rhodotorula rubra; or the fungi: Aspergillus flavus, Aspergillus niger, Mucor sp. and Trichophyton rubrum.

Anti-Bacterial Agents↗

Duplication and maintenance of heterochromatin domains.

To investigate the mechanisms that assure the maintenance of heterochromatin regions, we took advantage of the fact that clusters of heterochromatin DNA replicate late in S phase and are processed in discrete foci with a characteristic nuclear distribution. At the light microscopy level, within these entities, we followed DNA synthesis, histone H4 acetylation, heterochromatin protein 1 (Hp1alpha and -beta), and chromatin assembly factor 1 (CAF-1). During replication, Hp1alpha and -beta domains of concentration are stably maintained, whereas heterochromatin regions are enriched in both CAF-1 and replication-specific acetylated isoforms of histone H4 (H4Ac 5 and 12). We defined a time window of 20 min for the maintenance of this state. Furthermore, treatment with Trichostatin A (TSA), during and after replication, sustains the H4Ac 5 and 12 state in heterochromatin excluding H4Ac 8 and 16. In comparison, early replication foci, at the same level, did not display any specific enrichment in H4Ac 5 and 12. These data emphasize the specific importance for heterochromatin of the replication-associated H4 isoforms. We propose that perpetuation of heterochromatin involves self-maintenance factors, including local concentration of Hp1alpha and -beta, and that a degree of plasticity is provided by the cycle of H4 acetylation/deacetylation assisted by CAF-1.

Acetylation↗

Antimicrobial activity of Wedelia trilobata crude extracts.

A biological screening of activity against Gram-positive and Gram-negative bacteria, yeasts, and fungi of crude extracts from Wedelia trilobata is reported. The n-hexane extract showed antibacterial activity against Bacillus subtilis, Mycobacterium smegmatis, Staphylococcus aureus, and Staphylococcus epidermidis (Gram-positive bacteria); along with Proteus vulgaris, Pseudomonas aeruginosa, Salmonella group C, Salmonella paratyphi, and Shigella sonnei (Gram-negative bacteria). The ethyl acetate extract was active only against Salmonella group C; and the aqueous extract was inactive against the tested bacteria. None of the tested extracts showed biological activity against the yeasts (Candida albicans, Candida tropicalis, Rhodotorula rubra) or the fungi (Aspergillus flavus, Aspergillus niger, Mucor sp., Trichophyton rubrum).

Anti-Bacterial Agents↗

C3: Java-based medical record system for cardiology.

This paper describes a system for electronic medical record (EMR) we have developed for use in our health care institution, mainly dealing with diagnosis and treatment of cardiovascular pathologies. This activity is part of the project SPERIGEST, supported by Health Ministry of Italy, for the management of health care delivery, as concerns both clinical and administrative aspects. A networked computer-based information system was realized to integrate the different heterogeneous sources of patient information. Both clinical and administrative patient relevant data are provided from the various systems and stored into a central database. The EMR system was designed using World Wide Web (WWW) technology (Java, HTML). The system is currently under clinical evaluation.

Cardiology↗