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1.
Eur Rev Med Pharmacol Sci ; 28(1): 288-297, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38235899

RESUMO

OBJECTIVE: This study aimed to investigate the presence of psychopathological symptoms and the relations of these dimensions with the quality of life and sexual function in a group of women affected by systemic scleroderma. SUBJECTS AND METHODS: Seventy-one women with systemic scleroderma were invited to participate in the study; 65 agreed to participate, while 6 declined. Four questionnaires were administered to the patients: a specific socio-demographic questionnaire, the Symptom Checklist-90-Revised (SCL-90-R), the Female Sexual Function Index (FSFI), and the Quality-of-Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO-41). RESULTS: Of all the participants in this study, 48% of patients showed a clinical score on SCL-90-R Somatization, 45% on depression, and 37% on obsessive-compulsive. As hypothesized, psychopathological symptoms were related to lower quality of life since somatization and depression predicted the total score of health-related quality of life and lower sexual functions, showing a specific effect of depression on sexuality. CONCLUSIONS: Our findings highlighted the presence of an association between psychopathological symptoms and reduced sexual functioning and the associations between somatization and the health-related quality of life dimensions in scleroderma patients. Furthermore, our results sustain the importance of also considering the mental health of patients with systemic sclerosis, within an integrated biopsychosocial care model.


Assuntos
Transtornos Mentais , Escleroderma Sistêmico , Humanos , Feminino , Qualidade de Vida , Comportamento Sexual/psicologia , Inquéritos e Questionários
2.
Nucleic Acids Res ; 39(15): 6558-67, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21576230

RESUMO

Homologous recombination is essential for the preservation of genome stability, thereby preventing cancer. The recombination protein RAD51 drives DNA strand exchange, which requires the assembly, rearrangement and disassembly of a RAD51 filament on DNA, coupled to ATP binding and hydrolysis. This process is facilitated and controlled by recombination mediators and accessory factors. Here, we have employed a range of single molecule techniques to determine the influence of the C-terminal RAD51 interaction domain (CTRD) of the breast cancer tumor suppressor BRCA2 on intrinsic aspects of RAD51-DNA interactions. We show that at high concentration the CTRD entangles RAD51 filaments and reduces RAD51 filament formation in a concentration dependent manner. It does not affect the rate of filament disassembly measured as the loss of fluorescent signal due to intrinsic RAD51 protein dissociation from double-stranded DNA (dsDNA). We conclude that, outside the context of the full-length protein, the CTRD does not reduce RAD51 dissociation kinetics, but instead hinders filament formation on dsDNA. The CTRDs mode of action is most likely sequestration of multiple RAD51 molecules thereby rendering them inactive for filament formation on dsDNA.


Assuntos
Proteína BRCA2/metabolismo , Rad51 Recombinase/metabolismo , Proteína BRCA2/química , DNA/metabolismo , Cinética , Microscopia de Força Atômica , Microscopia de Fluorescência , Domínios e Motivos de Interação entre Proteínas , Rad51 Recombinase/análise , Rad51 Recombinase/química
3.
Clin Exp Rheumatol ; 28(6 Suppl 63): S82-6, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21176426

RESUMO

More than two third of patients with primary Sjögren's syndrome (SS) report fatigue. Despite its clinical relevance, only a few studies have examined the relationship of fatigue with the presence of an overlapping Fibromyalgia (FM) and other clinical and biological variables. The aim of this study was to assess the relationship between fatigue and SS disease activity and damage, FM, widespread pain, and mood disorders; finally, the possible correlation between fatigue and a panel of cytokines likely to drive the immunopathological process of the disease has been examined. Thirty-five female patients with primary SS were consecutively enrolled; for each patient the Sjögren's Syndrome Disease Damage Index (SSDDI) and the Sjögren's Syndrome Disease Activity Index (SSDAI) were calculated. Patients rated pain, fatigue and disease activity using a 100-mm VAS and completed Health Assessment Questionnaire (HAQ), the Zung depression (ZSDS) and anxiety scales (ZSAS). 30/35 patients (85.7%) felt unduly tired and the same percentage of patients suffered with pain in more than one area of the body. 7 patients satisfied ACR criteria for FM, representing 20% of the whole cohort and 23% of SS patients with fatigue. No differences were found in disease duration, SSDDI, SSDAI, ZSDS and ZSAS among SS patient with or without FM. In the whole group, fatigue VAS correlated with HAQ, ZSAS, ZSDS and pain VAS but not with age, disease duration, presence and severity of arthritis, SSDDI, SSDAI, or cytokines. In conclusion, an overlapping FM can contribute to, but does not entirely account for fatigue in Italian patients with primary SS.


Assuntos
Fadiga/etiologia , Fibromialgia/complicações , Síndrome de Sjogren/complicações , Adulto , Idoso , Ansiedade/etiologia , Ansiedade/fisiopatologia , Citocinas/sangue , Depressão/etiologia , Depressão/fisiopatologia , Fadiga/fisiopatologia , Feminino , Fibromialgia/imunologia , Fibromialgia/fisiopatologia , Humanos , Itália , Pessoa de Meia-Idade , Dor/etiologia , Dor/fisiopatologia , Síndrome de Sjogren/imunologia , Síndrome de Sjogren/fisiopatologia
4.
Clin Exp Rheumatol ; 28(2): 250-3, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20483048

RESUMO

OBJECTIVES: Osteoarthritis (OA) is a chronic rheumatic disease characterized by progressive cartilage destruction mediated by cytokines and other molecules. Chondrocyte activity and metabolism have attracted interest as targets of drug intervention, and spa-therapy can influence the serum levels of several cytokines. We investigated the effects of spa-therapy on clinical and ultrasonographic (US) findings and serum levels of cartilage oligomeric matrix protein (COMP) and several cytokines, chemokines, and growth factors in a prospective cohort of patients with symptomatic knee OA. METHODS: Patients (n=53) with primary symptomatic knee OA were treated for 12 consecutive days with locally applied mud-packs. Assessments were made at baseline, immediately after completion of the treatment cycle, and 6 and 12 months after completion of treatment. They included visual analogue scale (VAS) ratings of pain, the Lequesne algofunctional index for knee OA, and US with calculation of a semiquantitative score that expressed the severity of the local inflammatory process. Serum levels of 27 cytokines (including interferon--inducible protein-10 [IP-10]), chemokines, and growth factors were measured with multiplex bead-based immunoassays, and COMP levels were determined by ELISA. RESULTS: US scores, VAS pain ratings, and Lequesne indexes indicated significant improvement after spa-therapy and at the 6- and 12-month follow-ups. Serum IP-10 levels also dropped significantly (p=0.0035), and this reduction was positively correlated with improvement of the Lequesne index (p=0.031). CONCLUSIONS: In patients with knee OA, spa-therapy can modulate serum levels of proinflammatory cytokines/chemokines and produce improvements in joint pain and function that persists for up to 1 year.


Assuntos
Banhos/métodos , Estâncias para Tratamento de Saúde , Peloterapia/métodos , Osteoartrite do Joelho/terapia , Proteína de Matriz Oligomérica de Cartilagem , Estudos de Coortes , Citocinas/sangue , Proteínas da Matriz Extracelular/sangue , Glicoproteínas/sangue , Humanos , Proteínas Matrilinas , Osteoartrite do Joelho/sangue , Osteoartrite do Joelho/diagnóstico por imagem , Medição da Dor , Ultrassonografia
6.
Cancer Lett ; 281(1): 8-23, 2009 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-19091462

RESUMO

The repertoire of autoantibodies found in cancer patients partly overlaps with that typical of patients with autoimmune diseases. Beside the biochemical and immunological properties of the target antigens and their altered expression in tumor tissues, the intratumoral inflammatory context can play a key role in the induction of autoimmune disease-associated autoantibodies in cancer patients. Furthermore, the impact of such antibodies on cancer growth and progression can be deeply influenced by the interplay with inflammation. The characterization of the spontaneous humoral responses occurring in cancer patients, of the mechanisms that trigger and sustain the autoantibody response and of the biological effects of such autoantibodies may help the rational design of anti-cancer immunotherapeutic protocols.


Assuntos
Anticorpos Antineoplásicos/imunologia , Autoanticorpos/imunologia , Doenças Autoimunes/imunologia , Inflamação/imunologia , Neoplasias/imunologia , Animais , Anticorpos Monoclonais/imunologia , Antígenos de Neoplasias/imunologia , Autoantígenos/imunologia , Autoimunidade/imunologia , Linfócitos B/imunologia , Deleção Clonal , Progressão da Doença , Neoplasias Hematológicas/imunologia , Humanos , Camundongos , Modelos Imunológicos , Proteínas de Neoplasias/imunologia , Tolerância a Antígenos Próprios/imunologia
7.
Ultraschall Med ; 28(1): 57-62, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17304413

RESUMO

PURPOSE: To assess the efficacy of low mechanical index (MI) real time grey scale contrast-enhanced US (CEUS) in the differentiation of breast lesions in comparison to Magnetic Resonance Imaging (MRI). MATERIALS AND METHODS: 50 lesions previously detected at mammography or conventional US were evaluated by means of CEUS and MRI. Contrast-enhanced examinations were performed with a dedicated equipment (Esatune, Esaote, Genoa, Italy), before and after injection of 4.8 ml of Sonovue (Bracco, Milan, Italy). MRI was conducted with a 1.5 T equipment (Siemens Vision Plus, Erlangen, Germany) with bilateral dedicated superficial coil, on T2w STIR and 3D Flash T1w before and 1, 2, 3, 4, 5 minutes after the administration of contrast agent (Gd-DTPA, 1.5 ml/kg). Wash-in and wash-out curves were assessed for both procedures. A specific sonographic quantification software (Qontrast, Bracco, Milan, Italy), based on pixel by pixel signal intensity over time, was used to obtain contrast-enhanced sonographic perfusion maps for each lesion. Mc Nemar test was then calculated. RESULTS: 24 invasive ductal carcinomas, 18 fibroadenomas, 4 fibro-cystic dysplasias, 1 mucinous carcinoma, 1 invasive ducto-lobular carcinoma, 1 intraductal florid papillomatosis and 1 phylloides tumour were diagnosed. Contrast-enhanced sonographic patterns correlated well with those provided by MRI. Sensitivity, specificity, and accuracy of US were: 69.2 %, 66.7 %, and 68 %, respectively. According to the different contrast enhancement patterns and the resulting perfusion maps, all the malignant lesions and 9 out of 12 benign lesions were correctly diagnosed, thus resulting in 87.5 % of specificity and 100 % of sensitivity. Regarding the specificity, there is no difference between US and CEUS with McNemar (p = 0.18). Regarding sensitivity, the difference between contrast-enhanced US and US is significant as calculated with McNemar test (p = 0.013). The three lesions which were incorrectly classified as malignant were two hypervascularised fibroadenomas in young women and a phylloides tumour. CONCLUSION: CEUS seems to be a reliable method to differentiate breast lesions, since it provides typical enhancement patterns. Contrast sonographic perfusion curves correlate well with MRI wash in--wash out curves.


Assuntos
Doenças Mamárias/diagnóstico por imagem , Doenças Mamárias/diagnóstico , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama Masculina/diagnóstico , Neoplasias da Mama Masculina/diagnóstico por imagem , Meios de Contraste , Diagnóstico Diferencial , Feminino , Fibroadenoma/diagnóstico por imagem , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Ultrassonografia/métodos
8.
Int J Immunopathol Pharmacol ; 19(3): 661-74, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17026851

RESUMO

Employing purified extracellular matrix (ECM) proteins, i.e. type I, III, IV and V collagens (CI, CIII, CIV, CV), laminin (LM) and fibronectin (FN), as antigen sources we detected autoantibodies to conformational and/or denatured ECM antigens among 34 of 50 sera obtained from Hashimotos thyroiditis (HT) patients and 6 of 51 control sera obtained from non-autoimmune thyroid disease patients and healthy donors (HT sera vs. control sera p=4 x 10-9). Reactivity to conformational antigens, mostly due to autoantibodies of the IgG isotype, was observed in 30/50 HT sera and in 6/51 control sera (p=3.5 x 10-7) and was not always concomitant with that to linear antigens, found in 23/50 HT and in 6/51 control sera (p=1.6 x 10-4). Ultrastructural analysis of skin biopsies obtained from 18 HT patients without symptomatic cutaneous diseases revealed defects of the stratified squamous epithelium basement membrane in 11/18, alterations of the stroma in 13/18 and both basement membrane and stromal defects in 9/18. Interestingly, 13/13 (p=0.012) and 9/11 (p=0.012) patients with stromal and basement membrane defects respectively, exhibited serum antibodies to at least one ECM antigen involved in the organization of the altered tissue compartment. Lastly, 10/18 skin biopsies presented immunoglobulin (Ig) and/or complement (C3) deposits along the cutaneous basement membrane zone (BMZ) or in the papillary dermis and 9/10 sera from the same patients simultaneously showed antibodies to at least one ECM antigen involved in the organization of these two skin compartments. Besides, 8/11 HT patients with basement membrane defects exhibited Ig or C3 deposits along the BMZ. Our findings suggest that autoantibodies to ECM molecules might contribute to the development of asymptomatic extra-thyroid skin diseases in HT patients.


Assuntos
Autoanticorpos/sangue , Proteínas da Matriz Extracelular/imunologia , Doença de Hashimoto/imunologia , Pele/ultraestrutura , Membrana Basal/ultraestrutura , Complemento C3/análise , Ensaio de Imunoadsorção Enzimática , Epitélio/ultraestrutura , Doença de Hashimoto/patologia , Humanos , Isotipos de Imunoglobulinas/sangue , Imunoglobulinas/análise , Células Estromais/ultraestrutura
9.
J Nanosci Nanotechnol ; 5(6): 958-63, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16060160

RESUMO

This study focuses on the understanding of the reinforcing effect given by organo-modified layered silicates to a high-density polyethylene and the influence on the crystallization properties of this polymer. The addition of organo-modified clay to high-density polyethylene resulted in an evident increase in the tensile and flexural Young's modulus of the material with respect to unfilled polymer. The morphology, crystallinity, and thermo-oxidative stability of such nanocomposites were investigated using X-ray diffraction, transmission electron microscopy, differential scanning calorimetry, and oxidation induction time test. The materials obtained show tactoid as well as intercalated and exfoliated structures with different dominant states depending on the loading level and process conditions. It was observed that organic ions not only change mixing behavior but also influence material properties, including the degree of crystallinity and the stability to the thermo-oxidative phenomena.


Assuntos
Silicatos de Alumínio/química , Cristalografia/métodos , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Polietileno/química , Silicatos/química , Argila , Elasticidade , Teste de Materiais , Conformação Molecular , Nanoestruturas/análise , Compostos Orgânicos/química , Polietileno/análise , Silicatos/análise , Resistência à Tração
10.
Oncol Rep ; 13(4): 745-50, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15756452

RESUMO

Autocrine and paracrine mechanisms modulate the synthesis and secretion of extracellular matrix (ECM); moreover, each component of the ECM is capable of modulating the synthesis and release of other ECM molecules. Therefore, the synthesis of ECM glycoprotein fibronectin and laminin was studied in the human breast cancer cell lines MCF7 and MDA MB 23, plated on different ECM. Our results showed that the cells plated on a fibronectin substrate increased laminin synthesis: this event correlated with an increase in alpha2 and alpha3 integrin subunits. Staurosporine-induced apoptosis was then analyzed in the cell lines plated on different ECM. Staurosporine treatment determined the apoptosis of 35 and 33% respectively of MDA MB 231 and MCF7; these values increased to 60 and 64% in cells plated on laminin, to 48 and 63% in cells plated on fibronectin and to 64 and 69% in cells plated on matrigel. Moreover, staurosporine treatment decreased bcl-2 expression in the cells plated on fibronectin and laminin. Yet, staurosporine treatment determined PARP cleavage and PARP partial disappearance when the cells were plated on matrigel. Finally, a partial loss of function mutant Ras protein that activated only Raf pathway, was expressed in MCF7, in order to identify whether the increase of apoptosis induced by extracellular matrix involved the Raf/MAP kinase pathway. The increase of apoptosis of the cells plated on matrigel suggested that the activation of the Raf pathway is probably involved in the decrease of survival on matrigel. These data demonstrate that the modification of ECM modulates the apoptotic process of breast cancer cells and suggest that it is worthwhile to dissect the role of ECM in the control of apoptotic process.


Assuntos
Apoptose , Neoplasias da Mama/metabolismo , Inibidores Enzimáticos/farmacologia , Matriz Extracelular/metabolismo , Estaurosporina/farmacologia , Western Blotting , Neoplasias da Mama/patologia , Morte Celular , Linhagem Celular Tumoral , Separação Celular , Colágeno/farmacologia , Combinação de Medicamentos , Fibronectinas/biossíntese , Fibronectinas/química , Citometria de Fluxo , Humanos , Imunoprecipitação , Laminina/biossíntese , Laminina/química , Laminina/metabolismo , Laminina/farmacologia , Poli(ADP-Ribose) Polimerases/metabolismo , Polilisina/química , Proteoglicanas/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transfecção , Proteína Supressora de Tumor p53/metabolismo , Proteína X Associada a bcl-2
11.
G Chir ; 25(3): 95-7, 2004 Mar.
Artigo em Italiano | MEDLINE | ID: mdl-15224663

RESUMO

The Authors report a clinical case of mammary phyllodes tumor recurrence; characterized by the histological transformation of the recurrence respect to primary tumor. PT are 0.3-1% of all mammary neoplasia. They are classified with Tavassoli's criteria (1999). The surgical treatment of PT is the wide excision (WE). Local recurrences are detected in about 20% of patients undergone to surgery. Surgical therapy of recurrences depends on the histological grade of primary lesion. Authors believe it is necessary to perform simple mastectomy when high grade PT recurrences are detected and when histological transformation of the lesion changes from low grade to high grade.


Assuntos
Neoplasias da Mama/cirurgia , Recidiva Local de Neoplasia/cirurgia , Tumor Filoide/cirurgia , Neoplasias da Mama/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Tumor Filoide/patologia
12.
Microbes Infect ; 3(10): 851-7, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11580980

RESUMO

Infectious diseases are major causes, with malignancies, of morbidity and mortality in the elderly. Increased susceptibility to infections may result from underlying dysfunction of an aged immune system; moreover, inappropriate immunologic functions associated with aging can determine an insufficient response to vaccines. Impairments of cellular, humoral and innate immunity in the elderly, contributing to increased incidence of infectious diseases, are discussed in this review.


Assuntos
Envelhecimento/imunologia , Doenças Transmissíveis/imunologia , Animais , Humanos , Sistema Imunitário , Vacinas/imunologia
13.
Genome Biol ; 2(5): REVIEWS1014, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11387040

RESUMO

Recent experiments show that properly controlled recombination between homologous DNA molecules is essential for the maintenance of genome stability and for the prevention of tumorigenesis.


Assuntos
Recombinação Genética , Animais , Proteína BRCA1/fisiologia , Proteína BRCA2 , Dano ao DNA , DNA Helicases/fisiologia , Proteínas de Ligação a DNA/fisiologia , Humanos , Modelos Genéticos , Proteínas de Neoplasias/fisiologia , Neoplasias/genética , Rad51 Recombinase , Fatores de Transcrição/fisiologia
14.
Am J Hematol ; 67(2): 63-72, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11343377

RESUMO

The immunophenotype of circulating lymphocytes, including the intensity expression of surface receptors, changes with ageing. Until now, no results of systematic studies on age-dependent changes with respect to the expression of the major lymphocyte surface receptors in healthy elderly subjects have been reported. In order to identify age-related changes in both representation and immunophenotype of lymphocyte populations, we investigated, by means of triple-color whole-blood immunostaining and quantitative flow cytometry, the percent values and the absolute numbers, as well as the levels of surface antigen expression or antigen molecules per cell (ABC values x 10(3)), of different peripheral blood lymphocyte subsets from 23 healthy elderly subjects and 13 young donors. Naive (CD45RA+CD3+) T cells, total B cells, and CD5+ B lymphocytes are decreased (22%, 6%, 0.8% vs. 30%, 12%, 1.4%, respectively), whereas activated (HLA-DR+CD3+) and memory (CD45RO+CD3+) T cells, CD3+CD7- T lymphocytes, and lymphocytes expressing the NK marker CD56 are expanded in the elderly (2%, 53%, 13%, 6% vs. 0.8%, 45%, 8%, 8%, respectively). Moreover, T lymphocytes from elderly individuals express lower CD3 (61 +/- 10) compared to young (69 +/- 10). Considering the different T-cell populations, CD3 antigen is respectively decreased on CD45RO+ T cells (55 +/- 14 vs. 66 +/- 14) and up-regulated on CD56+ T lymphocytes (62 +/- 21 vs. 45 +/- 20). Increased CD8 expression characterizes CD3+CD7- lymphocytes (70 +/- 34 vs. 44 +/- 17) while HLA-DR on activated T cells is lower in old (39 +/- 7) than young (46 +/- 9) donors. CD7 is down-regulated both in T (22 +/- 3 vs. 28 +/- 3) and NK (48 +/- 18 vs. 71 +/- 18) cells, whereas CD2 expression, unchanged on NK cells, is up-regulated on T lymphocytes (54 +/- 10 vs. 41 +/- 8). Age-related changes in B-cell antigen expressions were also found: CD20 is increased (124 +/- 23 vs. 105 +/- 16) whereas, despite the unchanged CD5 expression of T cells, CD5 intensity on the B-cell subset co-expressing this antigen is higher in old (49 +/- 37) than in young (22 +/- 4) people. The observed changes in the expression of functionally important cellular receptors can contribute to the remodeling of immune function characteristic of the elderly. Moreover, since quantitative flow cytometry is becoming widely employed in clinical practice, our results also contribute to the assessment of specific age-dependent antigen expression changes to be considered for diagnostic approaches in the elderly.


Assuntos
Antígenos de Diferenciação/biossíntese , Subpopulações de Linfócitos/imunologia , Receptores de Superfície Celular/biossíntese , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Feminino , Citometria de Fluxo , Humanos , Sistema Imunitário/citologia , Sistema Imunitário/imunologia , Imunofenotipagem/métodos , Imunofenotipagem/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade
15.
Curr Biol ; 11(6): R229-32, 2001 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-11301269

RESUMO

Chromatin modifications regulate many nuclear processes. Recent studies on the phosphorylation of a histone 2A variant have revealed that this chromatin modification is a general and evolutionarily conserved cellular response to DNA double-strand breaks.


Assuntos
Cromatina/metabolismo , Reparo do DNA , Histonas/metabolismo , Animais , Dano ao DNA , DNA Nucleotidiltransferases/metabolismo , Humanos , Meiose/fisiologia , Proteínas Nucleares/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Recombinação Genética , VDJ Recombinases
16.
Nucleic Acids Res ; 29(6): 1317-25, 2001 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-11238998

RESUMO

DNA double-strand breaks (DSBs) in eukaryotic cells can be repaired by non-homologous end-joining or homologous recombination. The complex containing the Mre11, Rad50 and Nbs1 proteins has been implicated in both DSB repair pathways, even though they are mechanistically different. To get a better understanding of the properties of the human Mre11 (hMre11) protein, we investigated some of its biochemical activities. We found that hMre11 binds both double- and single-stranded (ss)DNA, with a preference for ssDNA. hMre11 does not require DNA ends for efficient binding. Interestingly, hMre11 mediates the annealing of complementary ssDNA molecules. In contrast to the annealing activity of the homologous recombination protein hRad52, the activity of hMre11 is abrogated by the ssDNA binding protein hRPA. We discuss the possible implications of the results for the role(s) of hMre11 in both DSB repair pathways.


Assuntos
Reparo do DNA , Proteínas de Ligação a DNA/metabolismo , DNA/metabolismo , Animais , Ligação Competitiva , Linhagem Celular , DNA/genética , DNA de Cadeia Simples/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/fisiologia , Humanos , Cinética , Proteína Homóloga a MRE11 , Oligonucleotídeos/metabolismo , Ligação Proteica , Proteína de Replicação A
17.
EMBO J ; 19(22): 5962-70, 2000 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-11080143

RESUMO

XRCC4 is essential for carrying out non-homologous DNA end joining (NHEJ) in all eukaryotes and, in particular, V(D)J recombination in vertebrates. Xrcc4 protein forms a complex with DNA ligase IV that rejoins two DNA ends in the last step of V(D)J recombination and NHEJ to repair double strand breaks. XRCC4-defective cells are extremely sensitive to ionizing radiation, and disruption of the XRCC4 gene results in embryonic lethality in mice. Here we report the crystal structure of a functional fragment of Xrcc4 at 2.7 A resolution. Xrcc4 protein forms a strikingly elongated dumb-bell-like tetramer. Each of the N-terminal globular head domains consists of a beta-sandwich and a potentially DNA-binding helix- turn-helix motif. The C-terminal stalk comprising a single alpha-helix >120 A in length is partly incorporated into a four-helix bundle in the Xrcc4 tetramer and partly involved in interacting with ligase IV. The Xrcc4 structure suggests a possible mode of coupling ligase IV association with DNA binding for effective ligation of DNA ends.


Assuntos
Reparo do DNA , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Sequência de Aminoácidos , Animais , Proteínas de Bactérias/química , Sítios de Ligação , Proteínas de Ciclo Celular/química , Cristalização , Cristalografia por Raios X , DNA/química , DNA/metabolismo , DNA Ligase Dependente de ATP , DNA Ligases/química , DNA Ligases/metabolismo , Proteínas de Ligação a DNA/genética , Dimerização , Humanos , Substâncias Macromoleculares , Camundongos , Modelos Moleculares , Dados de Sequência Molecular , Estrutura Quaternária de Proteína , Saccharomyces cerevisiae/genética , Homologia de Sequência de Aminoácidos
18.
Recenti Prog Med ; 91(10): 532-7, 2000 Oct.
Artigo em Italiano | MEDLINE | ID: mdl-11072743

RESUMO

Cancer patients show an increased susceptibility to develop thromboembolic diseases, suggesting that disorders of coagulation are very common in this pathology. Tumor cells possess the capacity to interact with the hemostatic system, activating the coagulation cascade and stimulating the prothrombotic properties of other blood cell components; the same events while inducing a hypercoagulable state, also contribute to the processes of tumor growth, neoangiogenesis and metastatic formation. Multiple risk factors associated with malignant disease contribute to the hypercoagulability state: stasis induced by prolonged bed rest, vascular invasion by the tumor and iatrogenic complications including the use of central vein catheters and chemotherapy. Several tests have been developed to assess the hypercoagulable state, however their clinical significance still needs to be defined, especially in terms of their predictive value for thrombosis. Clinical manifestations vary from localized deep venous thrombosis (DVT) or pulmonary embolism, more generally associated with solid tumors, to disseminated intravascular coagulation, frequent in hematologic malignancies and metastatic cancer. Diagnosis of idiopathic DVT, in the absence of other risk factors, could indicate the presence of occult cancer, but the usefulness of an extensive work-up to detect malignancy in terms of cost to benefit ratio still has to be demonstrated. Patients with cancer and thromboembolism must be treated with anticoagulant therapy; a large number of studies have shown that either low molecular weight heparins or standard unfractionated heparin for the treatment of acute deep vein thrombosis in hospitalized patients are equally safe and effective; however, the first treatment has been reported to be associated with a lower mortality. After an episode of thrombosis the patients should be protected by a long term course of oral anticoagulation, remaining high the risk of recurrence for as long as the cancer is active.


Assuntos
Transtornos da Coagulação Sanguínea/complicações , Neoplasias/complicações , Coagulação Sanguínea/fisiologia , Transtornos da Coagulação Sanguínea/sangue , Transtornos da Coagulação Sanguínea/terapia , Humanos , Neoplasias/sangue , Trombose/complicações , Trombose/etiologia , Trombose/terapia
19.
Gerontology ; 46(5): 242-8, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10965179

RESUMO

BACKGROUND: Substantial changes in both representation and function of T lymphocyte subsets have been reported with advancing age. However, till now, no systematic studies focused on age-dependent changes in the expression intensity of the major T lymphocyte surface receptors. OBJECTIVE: The present study was undertaken in order to establish age-related differences in lymphocyte subpopulations by simultaneously measuring three surface antigens in young and elderly people. METHOD: Peripheral blood T cell subsets from 20 healthy elderly individuals and 15 healthy young adult donors were examined by means of a quantitative three-color flow cytometry method. RESULTS: Activated (HLA-DR+) and memory (CD45RO+) T cells, CD3+CD7- T lymphocytes, and cells expressing natural killer (NK) markers (CD3-CD56+ NK cells and CD3+CD56+ T lymphocytes) were expanded, whereas T lymphocytes expressing the adhesion molecule CD62L were lower in elderly compared with young donors. In addition to alterations in the percentages of T cell subsets during senescence, several changes in the intensity expression of T cell antigens were also detected. CD3 antigen expression was downregulated on total T lymphocytes as well as on the memory T cell subset, while CD56+ T cells exhibited increased CD3 levels. Moreover, CD2 expression, unchanged on NK cells, was upregulated on T lymphocytes from elderly subjects. CD3+CD7- T cells exhibited increased expression of CD8 antigen, while the intensity expression of HLA-DR on activated T cells and CD7 on both T and NK lymphocytes was decreased. T cells from elderly subjects also exhibited higher expression of CD50 and CD62L adhesion molecules as compared with young ones. CONCLUSION: These T cell antigen expression modulations during senescence, in addition to the alteration in the frequency of the various T lymphocyte subsets, could contribute to the complex remodeling of the immune function characteristic of the elderly.


Assuntos
Envelhecimento/imunologia , Subpopulações de Linfócitos T/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos CD/metabolismo , Feminino , Citometria de Fluxo , Humanos , Memória Imunológica , Imunofenotipagem , Células Matadoras Naturais/imunologia , Ativação Linfocitária , Masculino , Pessoa de Meia-Idade
20.
Pathobiology ; 68(6): 245-50, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11493756

RESUMO

A complex reshaping characterizes cellular immunity in the elderly. In particular, the hallmark of the "senescence" of the T cell compartment is a decrease in the proportion of CD45RA+ naive T lymphocytes concomitantly with an expansion of CD45RO+ memory T cells. However, in addition to age-dependent changes in their representation, phenotypical and functional anomalies also characterize naive and memory T cell populations in the elderly. Since cell adhesion molecules (CAMs) are multifunctional receptors which play important roles not only in cell-to-cell and cell-to-matrix interactions but also in signal transduction and cell activation, we analysed, by means of a three-colour flow cytometry method, the proportion, absolute number and density expression or mean fluorescence intensity (MFI) of CD50 (ICAM-3) and CD62L (L-selectin homing receptor) adhesion receptors on CD45RA+ and CD45RO+ peripheral blood CD3+ T cell subsets from 10 healthy elderly subjects and 10 young controls. Our aim was to investigate age-dependent changes in the expression pattern of these CAMs on naive and memory lymphocytes which might contribute to the remodelling of the immune system in the elderly. We considered the mean values +/- standard deviations of the percentage, absolute number and MFI of positive cells. The percentage of naive T cells expressing CD50 was not significantly modified in aged (94.8 +/- 5.0%) compared to young individuals (97.8 +/- 3.2%). On the contrary, the percentage of memory T cells exhibiting CD50 was lower in elderly than young donors (92.0 +/- 6.4 vs. 98.3 +/- 2.2%; p < 0.01). The percentage of naive T cells expressing CD62L was decreased in the elderly donors (53.3 +/- 18.8 vs. 80.8 +/- 11.0%; p < 0.001), whereas the proportion of CD62L+ memory T lymphocytes was substantially comparable between the two age groups (63.5 +/- 15.7 vs. 54.7 +/- 12.3%). The absolute number per mm(3) of CD50+ naive T cells from aged individuals was decreased (251.9 +/- 141.9 vs. 621.8 +/- 238.0/mm(3); p < 0.001), whereas memory peripheral blood T lymphocytes expressing CD50 were substantially unchanged (863.8 +/- 260.9 vs. 802.7 +/- 139.6/mm(3)). On the contrary, the absolute numbers per mm(3) of naive and memory peripheral blood T lymphocytes exhibiting CD62L were respectively decreased (190.8 +/- 133.4/mm(3)) and increased (515.1 +/- 146.8/mm(3)) in elderly donors compared to young controls (601.3 +/- 129.1 and 351.8 +/- 195.0/mm(3); p < 0.001 and p < 0.05, respectively). Finally, CD50 MFI values of naive as well as memory T cell subpopulations from aged subjects were increased compared to young donors (14.0 +/- 2.0 vs. 9.8 +/- 1.2 and 14.0 +/- 2.0 vs. 11.6 +/- 1.3; p < 0.001 and p < 0.01, respectively). CD62L was also overexpressed in both naive (8.4 +/- 1.6 vs. 6.7 +/- 1.4; p < 0.05) and memory (10.3 +/- 2.5 vs. 5.4 +/- 1.1; p < 0.001) T subsets in the elderly. CD50 and CD62L upregulation could be interpreted as a compensatory mechanism for a decreased responsiveness and a greater requirement for activation signals rather than an age-related anomaly.


Assuntos
Envelhecimento/imunologia , Antígenos CD , Antígenos de Diferenciação , Moléculas de Adesão Celular/biossíntese , Memória Imunológica/imunologia , Receptores de Retorno de Linfócitos/biossíntese , Subpopulações de Linfócitos T/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Contagem de Células , Feminino , Citometria de Fluxo , Humanos , Antígenos Comuns de Leucócito/biossíntese , Masculino , Pessoa de Meia-Idade
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