Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 181
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Psychooncology ; 27(8): 1971-1978, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29740909

RESUMO

OBJECTIVE: Changes perceived as both positive (eg, posttraumatic growth [PTG]) and negative (eg, posttraumatic stress symptoms [PTSS]) have been associated with intensive Internet use among breast cancer survivors. In this multicenter study, we analyzed the role of PTG and PTSS on the amount of time spent looking for online cancer information, its content, and its psychological impact. METHODS: Posttraumatic stress symptoms and PTG were assessed in 182 breast cancer survivors by using the Post-traumatic Stress Disorder Checklist and Post-traumatic Growth Inventory questionnaires. Subjects also completed a questionnaire about their behavior when looking for online illness-related information (ie, time spent, type of contents, and psychological impact). RESULTS: Posttraumatic stress symptoms positively correlated with the amount of time spent looking for cancer-related information, including both medical and psychosocial content. By contrast, PTG showed no relationships with the amount of time, but with a predominant search for cancer-related psychosocial information. The psychological impact of online information was associated with participants' levels of PTG and/or PTSS. Whereas PTG was related to a decrease of women's hope, PTSS was linked to the perception of being less conscious or inadequately informed about the illness, thereby increasing feelings of distress. CONCLUSIONS: Posttraumatic stress symptoms and PTG show relationships with the amount of time spent online, the type of information accessed online, and the psychological impact of Internet use. Health professionals should prescribe online information according to the psychological response to cancer. There is a need for professional-led online resources to provide patients with timely information as well as support sites to facilitate psychological adjustment.


Assuntos
Acesso à Informação/psicologia , Neoplasias da Mama/psicologia , Sobreviventes de Câncer/psicologia , Comportamento de Busca de Informação , Transtornos de Estresse Pós-Traumáticos/psicologia , Adaptação Psicológica , Adulto , Atitude Frente a Saúde , Neoplasias da Mama/terapia , Ajustamento Emocional , Feminino , Esperança , Humanos , Internet , Pessoa de Meia-Idade , Crescimento Psicológico Pós-Traumático , Transtornos de Estresse Pós-Traumáticos/diagnóstico , Inquéritos e Questionários
2.
Biotechnol Lett ; 36(10): 2143-53, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24966043

RESUMO

Clinical translation of emerging technologies aiming at cartilage resurfacing is hindered by neither the appropriate scaffold design nor the optimal cell source having been defined. Here, critical-sized, chondral-only focal defects were created in sheep and treated with clinical-grade, co-polymeric poly-lactide:polyglycolic acid scaffolds either alone or seeded with 3.3 × 10(6) ± 0.4 × 10(6) autologous bone marrow-derived mesenchymal stromal cells and studied over 12 month follow-up. An untreated group was included for comparison. Second-look arthroscopy performed at 4 months post-treatment evidenced the generation of neocartilage of better quality in those defects treated with cells. However, macroscopic scores in the cell-treated group declined significantly from 7.5 ± 2.3 at 4 months to 3.1 ± 2.6 (p = 0.0098) at 12 months post-treatment, whereas the other two experimental groups remained unaltered during 4-12 month post-treatment. The effectiveness of the cell-based approach proposed in this study is thus restricted to between months 1 and 4 post-treatment.


Assuntos
Doenças das Cartilagens/terapia , Articulação do Joelho/patologia , Células-Tronco Mesenquimais/citologia , Poliésteres/química , Ácido Poliglicólico/química , Animais , Materiais Biocompatíveis/química , Doenças das Cartilagens/metabolismo , Cartilagem Articular/química , Modelos Animais de Doenças , Transplante de Células-Tronco Mesenquimais , Ovinos , Engenharia Tecidual , Alicerces Teciduais
3.
Unfallchirurg ; 116(7): 582-8, 2013 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-22699317

RESUMO

INTRODUCTION: Antegrade intramedullary nailing is the method of choice in most femoral shaft fractures. The trochanteric entry portal of classic femoral nails is in close proximity to the piriformis tendon, the gluteus minimus tendon, the obturator tendons, and the medial femoral circumflex artery. Nail insertion lateral to the tip of the greater trochanter may be more favorable but needs the use of a helical implant. MATERIAL AND METHODS: Measurement of the reamer pathway through an entry point lateral to the superior trochanteric border was performed with a three-dimensional motion tracking sensor in human cadaveric femurs. These results provided a scientific rationale for the design of a helical femoral nail (LFN®). In a prospective multicenter study a total of 227 femoral shaft fractures were treated by nailing with the LFN. Patients were followed at 3 months (n=193) and 12 months (n=167). RESULTS: The ease of defining the entry point and inserting the nail was rated as"very good and good" by 90% of the surgeons. Intraoperative technical complications included incomplete reduction (14%), additional iatrogenic fractures (6%), and difficulties in interlocking (3.5%). At the 1-year follow-up, delayed unions were seen in 10%, secondary loss of reduction in 3%, and deep infection in 1.8% of the patients. Angular malalignment of more than 5° was seen in 5%, mostly in valgus. A normal walking capacity was seen in 68% and normal active hip flexion in 45%. CONCLUSION: The results obtained in this study during 1 year do not provide evidence for an advantage of the LFN over conventional antegrade femoral nails.


Assuntos
Pinos Ortopédicos/estatística & dados numéricos , Fraturas do Fêmur/epidemiologia , Fraturas do Fêmur/cirurgia , Fixação Intramedular de Fraturas/instrumentação , Fixação Intramedular de Fraturas/estatística & dados numéricos , Complicações Pós-Operatórias/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Cadáver , Análise de Falha de Equipamento , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/prevenção & controle , Prevalência , Desenho de Prótese , Recuperação de Função Fisiológica , Fatores de Risco , Resultado do Tratamento , Adulto Jovem
4.
J Hosp Infect ; 130: 44-51, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36100140

RESUMO

BACKGROUND: Development of methodologies to quantify airborne micro-organisms is needed for the prevention and control of infections. It is difficult to conclude which is the most efficient and sensitive strategy to assess airborne SARS-CoV-2 RNA levels due to the disparity of results reported in clinical settings. AIM: To improve our previously reported protocol of measuring SARS-CoV-2 RNA levels, which was based on bioaerosol collection with a liquid impinger and RNA quantification with droplet digital polymerase chain reaction (ddPCR). METHODS: Air samples were collected in COVID-19 patient rooms to assess efficiency and/or sensitivity of different air samplers, liquid collection media, and reverse transcriptases (RT). FINDINGS: Mineral oil retains airborne RNA better than does hydrophilic media without impairing integrity. SARS-CoV-2 ORF1ab target was detected in 80% of the air samples using BioSampler with mineral oil. No significant differences in effectiveness were obtained with MD8 sampler equipped with gelatine membrane filters, but the SARS-CoV-2 copies/m3 air obtained with the latter were lower (28.4 ± 6.1 vs 9 ± 1.7). SuperScript II RT allows the detection of a single SARS-CoV-2 genome RNA molecule by ddPCR with high efficiency. This was the only RT that allowed the detection of SARS-CoV-2 N1 target in air samples. CONCLUSION: The collection efficiency and detection sensivity of a protocol to quantify SARS-CoV-2 RNA levels in indoor air has been improved in the present study. Such optimization is important to improve our understanding of the microbiological safety of indoor air.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/prevenção & controle , RNA Viral/genética , Óleo Mineral
5.
Actas Urol Esp (Engl Ed) ; 46(5): 275-284, 2022 06.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-35260370

RESUMO

OBJECTIVES: To evaluate the outcomes of robot-assisted radical prostatectomy (RARP) compared to those of open (ORP) and laparoscopic (LRP) surgery. The interest lies fundamentally in the quality-of-life (QoL) evaluation, postoperative recovery, and personal satisfaction of patients with the intervention (PS) beyond oncological and functional outcomes. METHODS: Six hundred eighty-five RPs were performed in our center between 2011-2018 (17,8% ORP, 22,2% LRP and 60% RARP). Patients were prospectively assessed through follow-up until April 2020 and a multiple questionnaire at 12-months post-RP that included ICIQ-SF, SHIM, IPSS, IQL and questions about pain, postoperative recovery and PS. Also baseline and postoperative patient- and treatment-related data were collected, and binomial logistic regressions were performed for the 1 vs.1 comparisons (ORP vs. RARP and LRP vs. RARP). RESULTS: RARP patients have overall fewer comorbidities, less tumor aggressiveness, more operative time requirements and more positive surgical margins than ORP and LRP patients. Nevertheless, RARP outperforms ORP in: hospital stay (days) (OR 0,86; 95% CI: 0,80-0,94), hemoglobin loss (OR 0,38; 95% CI: 0,30-0,47), transfusion rate (OR 0,18; 95% CI: 0,09-0,34), early complications (p = 0,001), IQL (OR 0,82; 95% CI: 0,69-0,98), erectile function (OR 0,41; 95% CI: 0,21-0,79), pain control (OR 0,82; 95% CI: 0,75-0,89), postoperative recovery (p < 0,001) and choice of a different approach (OR 5,55; 95% CI: 3,14-9,80). RARP is superior to LRP in: urinary continence (OR 0,55; 95% CI: 0,37-0,82), IPSS (OR 0,96; 95% CI: 0,93-0,98), IQL (OR 0,76; 95% CI: 0,66-0,88), erectile function (OR 0,52; 95% CI: 0,29-0,93), postoperative recovery (p = 0,02 and 0,004), PS (p = 0,005; 0,002; and 0,03) and choice of a different approach (OR 7,79; 95% CI: 4,63-13,13). CONCLUSIONS: The findings of our study globally endorse a positive effectiveness of RARP over ORP and/or LRP, both on functional issues, postoperative recovery, QoL and PS. Oncologic results should still be improved.


Assuntos
Disfunção Erétil , Procedimentos Cirúrgicos Robóticos , Disfunção Erétil/etiologia , Humanos , Masculino , Prostatectomia/métodos , Qualidade de Vida , Procedimentos Cirúrgicos Robóticos/métodos , Resultado do Tratamento
6.
Rheumatol Int ; 31(11): 1471-7, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20473758

RESUMO

Temporary work disability (TWD) is more common in patients with fibromyalgia (FM) than among the rest of the workers. To describe the differences between patients who take sick leave (TWD group) and those who continue to work regularly (control group). To determine what factors are associated with TWD. Multicentre, cross-sectional study with a cohort of patients with FM seen in rheumatology clinics throughout Spain. The following information was recorded: demographic data, clinical manifestations, comorbidities, health self-perception, emotional issues, functional capacity, physical function tests, utilization of healthcare resources, TWD during the past 12 months, and quitting paid employment due to the disease. Descriptive statistics was used to compare variables between the TWD group and the control group. A logistic regression analysis was done to determine which factors are associated with TWD. The study cohort was composed of 301 patients with FM (women: 96.7%) with a mean age of 48.7 ± 8.5 years and a disease duration of 11.5 ± 9.1 years. There were 56.8% active workers, of whom 67.8% had had some TWD. The mean TWD length was 44 ± 69.6 days/year. TWD correlated significantly with sedentary work, clinical manifestations, comorbidities, self-perceived health, poor functional capacity, physical function, and healthcare resource utilization. The factors independently associated with TWD are sedentary work, more clinical manifestations, fatigue, and poor flexibility. Of the cases of people who quit their jobs, 66.9% were associated with FM. TWD in patients with FM is associated with sedentary work, a worse clinical situation, and worse functional capacity.


Assuntos
Emprego , Fibromialgia/fisiopatologia , Licença Médica , Avaliação da Capacidade de Trabalho , Estudos de Coortes , Estudos Transversais , Avaliação da Deficiência , Feminino , Fibromialgia/economia , Custos de Cuidados de Saúde , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Ambulatório Hospitalar , Fatores de Tempo
7.
J Exp Med ; 179(6): 1747-56, 1994 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-7515097

RESUMO

The leukocyte differentiation antigen, CD50, has been recently identified as the intercellular adhesion molecule 3 (ICAM-3), the third counter-receptor of leukocyte function-associated antigen 1 (LFA-1). This molecule seems to be specially involved in the adhesion events of the initial phases of the immune response. To characterize the role of CD50 in leukocyte interactions, the different molecular events induced after cross-linking of CD50 on T cell-derived Jurkat cell line have been analyzed. When cells were incubated with anti-CD50 mAbs and cross-linked with polyclonal goat anti-mouse immunoglobulins, a rise in intracellular calcium concentration ([Ca2+]i) was observed. This increase in [Ca2+]i was mainly due to the uptake of extracellular Ca2+. This Ca2+ flux involved tyrosine phosphorylations and was further increased by CD3 costimulation. These data, together with those obtained by phosphotyrosine (P-Tyr) immunoprecipitation and in vitro kinase assays, suggested the involvement of protein-tyrosine kinases (PTK) in CD50 transduction pathways. By using specific antisera, the presence of p56lck and p59fyn protein tyrosine kinases (PTK) was clearly demonstrated in the CD50 immunoprecipitates. These findings suggest that the interaction of CD50 with its natural ligand (LFA-1) may result in T lymphocyte activation events, in which CD50 could play a very active role after antigen triggering.


Assuntos
Antígenos CD , Antígenos de Diferenciação , Cálcio/metabolismo , Moléculas de Adesão Celular/fisiologia , Proteínas Tirosina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Animais , Anticorpos/farmacologia , Anticorpos Monoclonais/farmacologia , Complexo CD3/efeitos dos fármacos , Complexo CD3/fisiologia , Moléculas de Adesão Celular/efeitos dos fármacos , Moléculas de Adesão Celular/imunologia , Linhagem Celular , Quelantes , Humanos , Indóis , Cinética , Proteína Tirosina Quinase p56(lck) Linfócito-Específica , Camundongos/imunologia , Fosfatos/metabolismo , Radioisótopos de Fósforo , Fosforilação , Fosfotirosina , Proteínas Proto-Oncogênicas c-fyn , Linfócitos T , Células Tumorais Cultivadas , Tirosina/análogos & derivados , Tirosina/análise , Tirosina/metabolismo
8.
Clin Exp Rheumatol ; 27(5 Suppl 56): S39-45, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20074438

RESUMO

OBJECTIVE: Fibromyalgia (FM) patients have been regarded as great utilizers of health resources, with important related costs. The aim of this study is to describe health care resource utilisation and related costs of FM from the perspective of the National Health System in Spain. PATIENTS AND METHODS: A cross-sectional multicenter study was conducted on FM patients based on a patient interview. Data about demographic and clinical variables, physical examination, self-perceived health, psychosocial variables and health resource utilisation, were collected. Direct and indirect costs were calculated, and a correlational study between costs and clinical variables was performed. RESULTS: Three-hundred and one patients were studied. During the year 2006 the mean total cost per patient per year was 9,982 Euros, of which 3,245.8 (32.5%) corresponded to health care costs and 6,736.2 (67.5%) to indirect costs attributable to productivity losses. Non-drug therapies accounted for the largest proportion of the health care costs, three times greater than the drug treatment. Patients with higher total costs showed the greatest disease involvement. The variables associated to the total health care costs were functional capacity, depression, comorbidities and age. Patients with permanent working disability were the greatest resource utilizers. CONCLUSIONS: FM patients with higher costs show the greatest disease involvement. Direct and indirect costs are well correlated to disease severity. The indirect costs account for most of the economic burden of FM and approximately double the health care costs. Patients with permanent working disability present more severe disease and generate greater health care costs.


Assuntos
Efeitos Psicossociais da Doença , Fibromialgia/economia , Custos de Cuidados de Saúde , Recursos em Saúde/economia , Recursos em Saúde/estatística & dados numéricos , Adulto , Idoso , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Índice de Gravidade de Doença , Fatores Socioeconômicos , Espanha , Inquéritos e Questionários
11.
Cancer Res ; 51(16): 4436-42, 1991 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-1868464

RESUMO

The p53 gene is a tumor suppressor gene located on chromosome 17p. Deletions of this chromosome and point mutations of p53 have been implicated in the development of colonic neoplasms. We have analyzed the loss of heterozygosity of the human p53 tumor suppressor gene in 40 cases of colorectal carcinoma using two restriction fragment length polymorphisms detected by BglII and AccII restriction enzymes. p53 gene product expression was studied immunohistochemically in 64 colorectal carcinomas, 18 adenomas, and 40 normal colonic mucosae using an anti-human p53 monoclonal antibody (Pab 1801) and the avidin-biotin-peroxidase complex technique. Twelve of the 40 patients (30%) were polymorphic for the p53 gene. In ten of these informative patients (83%), the tumor samples showed the loss of one allele when compared with normal colorectal samples of the same patient. One of the homozygous patients showed a loss of both p53 alleles. p53 immunostaining was observed in 43 of 64 carcinomas (67%) but only in two adenomas (11%). These two positive adenomas showed areas of carcinoma in situ. The normal mucosa was always negative. No relation could be found between p53 immunostaining and the degree of differentiation, the extension of the tumor, or the Ki-67 proliferative index. Mucinous carcinomas and right-side carcinomas were less p53 immunoreactive (25% and 52%, respectively) than the usual adenocarcinomas (73%) and distal tumors (72%). These findings suggest that p53 may be a target of chromosome 17 deletions and that this gene may play a role in the malignant transformation of adenomas. BglII and AccII restriction fragment length polymorphism analysis of the p53 gene may be a useful and direct technique to detect allelic loss of this gene in tumors.


Assuntos
Adenocarcinoma/genética , Cromossomos Humanos Par 17 , Neoplasias do Colo/genética , Genes Supressores de Tumor , Heterozigoto , Neoplasias Retais/genética , Proteína Supressora de Tumor p53/genética , Adenocarcinoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais , Neoplasias do Colo/patologia , Feminino , Expressão Gênica , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Retais/patologia
12.
Cytotechnology ; 68(4): 907-19, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25595211

RESUMO

Current developments in tissue engineering strategies for articular cartilage regeneration focus on the design of supportive three-dimensional scaffolds and their use in combination with cells from different sources. The challenge of translating initial successes in small laboratory animals into the clinics involves pilot studies in large animal models, where safety and efficacy should be investigated during prolonged follow-up periods. Here we present, in a single study, the long-term (up to 1 year) effect of biocompatible porous scaffolds non-seeded and seeded with fresh ex vivo expanded autologous progenitor cells that were derived from three different cell sources [cartilage, fat and bone marrow (BM)] in order to evaluate their advantages as cartilage resurfacing agents. An ovine model of critical size osteochondral focal defect was used and the test items were implanted arthroscopically into the knees. Evidence of regeneration of hyaline quality tissue was observed at 6 and 12 months post-treatment with variable success depending on the cell source. Cartilage and BM-derived mesenchymal stromal cells (MSC), but not those derived from fat, resulted in the best quality of new cartilage, as judged qualitatively by magnetic resonance imaging and macroscopic assessment, and by histological quantitative scores. Given the limitations in sourcing cartilage tissue and the risk of donor site morbidity, BM emerges as a preferential source of MSC for novel cartilage resurfacing therapies of osteochondral defects using copolymeric poly-D,L-lactide-co-glycolide scaffolds.

13.
J Mol Biol ; 185(2): 371-87, 1985 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-3932657

RESUMO

Using X-ray diffraction we have studied fibres obtained from complexes of DNA with lysine-rich polypeptides and with proteins that have different conformations, to ascertain whether the conformations of the polypeptides and the DNA are maintained upon interaction. Substances investigated include N-acetyl-Lys-Ala-Tyr-Ala-Lys-ethylamide, random poly(Leu50, Lys50), sequential poly(Leu-Lys), poly(Val-Lys), poly(Ala-Lys), poly(Lys-Ala-Ala-Lys), poly(Lys-Ala-Ala), poly(Lys-Leu-Ala), poly(Lys-Ala-Gly), protein phi 0 from sea cucumber spermatozoa, histone H1 and two fragments of this protein obtained by chemical cleavage. In general, the B form of DNA with ten base-pairs per helical turn is maintained upon interaction at high levels of humidity. The A form is never observed; it appears to be forbidden in a protein environment. No evidence for transition into any novel DNA conformation has been observed, although the B form is altered in some cases, in particular upon dehydration. Such alteration occurs always in the sense of tightening the double helix, so that the number of base-pairs per helical turn diminishes. The polypeptides may interact with DNA in both the alpha and beta conformations. We have found different types of complexes in which either a monolayer or a double layer of beta-pleated sheets is intercalated between layers of DNA molecules. Alternatively, the polypeptide chain may be wrapped around the DNA, following one of the grooves. The polypeptide conformation may be either maintained or changed upon interaction. The charge density of the polypeptide is an important parameter of the interaction. When it matches the charge density of the DNA, the polypeptide conformation is maintained in most cases; otherwise it is modified. The globular part of histone H1 gives a unique X-ray pattern upon interaction, indicative of a loss of order of DNA in the complex. On the other hand, the C-terminal part of histone H1 gives a very well-ordered complex, similar to a nucleoprotamine, in spite of its lower charge density.


Assuntos
DNA , Lisina , Peptídeos , Proteínas , Sequência de Aminoácidos , Animais , Masculino , Conformação de Ácido Nucleico , Peptídeos/análise , Conformação Proteica , Pepinos-do-Mar , Espermatozoides/análise , Difração de Raios X
14.
Mol Immunol ; 26(12): 1187-90, 1989 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2633049

RESUMO

As judged by Western blot analysis, phorbol 12-myristate 13-acetate (PMA) and phorbol 12,13-dibutyrate (PDBU) induce the rapid and dose-dependent appearance of slower mobility CD5 molecular forms from peripheral blood mononuclear cell (PBMC) and thymus cell lysates. This phenomenon was inhibited by staurosporine, suggesting that it can be mediated by PKC activation. Furthermore, under our experimental conditions, neither Concanavalin A, nor Phytohaemagglutinin P or the calcium ionophore A23187 were able to reproduce the phorbol ester-induced changes in the CD5 electrophoretic mobility. When immunoprecipitated from phorbol ester-stimulated P32 labelled PBMC lysates, the slower mobility of CD5 molecules was associated to important phosphorylation. This special electrophoretic behaviour after phorbol ester-stimulation makes CD5 different from other lymphocyte surface glycoproteins and may have important implications in the elucidation of the biological role of this molecule as discussed below.


Assuntos
Antígenos CD/análise , Leucócitos Mononucleares/imunologia , Ésteres de Forbol/farmacologia , Alcaloides/farmacologia , Western Blotting , Criança , Relação Dose-Resposta Imunológica , Eletroforese em Gel de Poliacrilamida , Humanos , Cinética , Peso Molecular , Proteína Quinase C/antagonistas & inibidores , Estaurosporina , Linfócitos T/imunologia
15.
Mol Immunol ; 21(6): 537-43, 1984 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-6379416

RESUMO

A rapid, simple and reliable technique for determining the affinities of antibody subpopulations in a complex mixture is described. The principle of this method is that antigen conc can be represented as the amount of antigen immobilized on the polystyrene surface of a microwell containing a fixed vol of diluted antibody. Thus, by measuring the proportion of antibody bound to different wells coated with varying amounts of antigen, it is a straightforward matter to calculate an affinity distribution. We have verified that: (1) the amount of antigen bound to a polystyrene plate is proportional to the concn of antigen used for sensitization and follows a typical saturation curve; (2) the antibodies bound to plates sensitized with low concns of antigen are of higher affinity than those bound to plates sensitized with high concns of antigen; (3) an apparent affinity constant (aK) is defined as the reciprocal concn of free hapten required for 50% inhibition of antibody binding to immobilized antigen; (4) the aK determined by this method is in close agreement with the intrinsic affinity constant (K) measured by fluorescence quenching or the Farr assay; and (5) that during the course of immunization in vivo there is a clear shift to higher-affinity antibody subpopulations.


Assuntos
Afinidade de Anticorpos , Ensaio de Imunoadsorção Enzimática/métodos , Haptenos/imunologia , Técnicas Imunoenzimáticas , Animais , Anticorpos/imunologia , Ácido Arsanílico , Soros Imunes , Camundongos , Tirosina
16.
Protein Sci ; 5(1): 167-9, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8771210

RESUMO

The refined structure of the Fab fragment of the monoclonal antibody CRIS-I (IgG2a kappa) against the leukocyte differentiation antigen CD5, determined at 1.9 A resolution with an agreement R-factor of 18.3%, reveals a variant of the canonical conformations proposed for the light chain complementarity determining region L3 (CDR-L3). This is the first Fab structure available with a kappa light chain in which the CDR-L3 lacks the key proline residue in either position 94 or 95. The conformation found could be significant for about 10% of the murine IgG molecules with kappa light chains without proline in their CDR-L3 sequences.


Assuntos
Fragmentos Fab das Imunoglobulinas/química , Animais , Cristalização , Região Variável de Imunoglobulina , Camundongos , Conformação Proteica
17.
J Immunol Methods ; 94(1-2): 137-44, 1986 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-3782806

RESUMO

A peroxidase saturation technique for the determination of coating antigen concentration necessary to saturate polystyrene plates with a wide range of different antigens is described. The same technique has also been used to compare the stability of antigen-polystyrene bonds for native and denaturated antigens. Furthermore, the inappropriate selection of solid-phase antigen concentration and its influence on ELISA results is analyzed and an experimental criterion to select the optimum antigen concentration is proposed. Two different antigens, BSA-Ar and hydatid antigen, were used for ELISA determination of specific antibodies as a model system. Optimum solid-phase antigen concentration was determined by two different methods: peroxidase saturation, in which binding of peroxidase to non-antigen-occupied polystyrene surface sites was used to evaluate the degree of coating by antigen; chequer-board titration, using several immune sera of different affinity. Optimum antigen concentration selected by chequer-board titration using low affinity sera was similar to that selected with peroxidase saturation. On the other hand, lower antigen concentration would be selected by chequer-board titration using high affinity sera. For this reason, the concentrations of low affinity antibodies would be underestimated using the chequer-board titration. These results indicate that peroxidase saturation should be used to avoid avidity-dependent artifacts in ELISA.


Assuntos
Antígenos/análise , Ensaio de Imunoadsorção Enzimática/métodos , Animais , Camundongos , Peroxidases , Poliestirenos , Desnaturação Proteica , Soroalbumina Bovina
18.
Transplantation ; 66(10): 1362-8, 1998 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-9846523

RESUMO

BACKGROUND: The hyperacute rejection induced by natural antibodies is the first barrier to the success of pig to human organ xenotransplantation. When this barrier is overcome, an infiltrate of mainly monocytes and natural killer cells can be observed. Nitric oxide (NO) has been described to be involved in allo- and xenorejection, and to participate in the regulation of monocyte infiltration in other models. METHODS: We have studied the capacity of human monocytes and natural antibodies to induce the production of NO by pig endothelial cells, by measuring NO2, a stable end product of NO. RESULTS: Human monocytes can induce HuProVim (HUP), a pig endothelial line, and "in situ, ex vivo" pig endothelial cells to produce NO2. This NO2 production was inhibited by NG-nitro-L-arginine-methylester and NG-monomethyl-L-arginine, inhibitors of NO production. This induction can be observed even if cells are separated by a semipermeable membrane, which indicates that it is a result of soluble factors. Activated cells continue producing NO after triggering for 1 hr. No NO2 production was observed after activation of HUP cells with recombinant human interleukin (IL)-1alpha, IL-1beta, IL-6, IL-10, transforming growth factor-beta1, IL-2, IL-4, interferon-gamma, or recombinant human tumor necrosis factor-alpha (rhTNF-alpha) alone. Only the combination of rhTNF-alpha+rIL-1alpha or rIL-1beta, and rhTNF-alpha+rIL-1alpha+IFN-gamma induces some NO production. Human natural anti-pig antibodies, which had been described to induce cytoskeleton changes on endothelial cells, do not induce NO production. CONCLUSIONS: Our data show that human monocytes induce the production of NO by pig endothelial cells. The inducing signal is soluble and cannot be provided by human anti-pig natural antibodies.


Assuntos
Endotélio Vascular/citologia , Óxido Nítrico/biossíntese , Animais , Artérias/citologia , Artérias/metabolismo , Linhagem Celular , Técnicas de Cocultura , Endotélio Vascular/metabolismo , Humanos , Lipopolissacarídeos/farmacologia , Monócitos/citologia , Óxido Nítrico/antagonistas & inibidores , Suínos , Fatores de Tempo , Fator de Necrose Tumoral alfa/fisiologia
19.
Thromb Haemost ; 51(1): 93-6, 1984 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-6232732

RESUMO

A monoclonal antibody (Mab) named EDU-3, was produced by fusing splenocytes from one Balb/c mouse, immunized with a mixture of platelets and non-T cells from heparinized human peripheral blood, with the HAT-sensitive myeloma line P3-NS1/1.Ag4.1. By indirect immunofluorescence (IF) it was seen that this Mab reacted with all normal human platelets and bone marrow megakaryocytes, but did not react with lymphoid cells from normal donors, or platelets from Glanzmann's thrombasthenia (GT) patients. Immunoprecipitation and SDS-PAGE experiments demonstrated that this Mab recognized an epitope on the IIb-IIIa glycoprotein complex (GPC). EDU-3 inhibited platelet aggregation and release of ATP induced by ADP and epinephrine. Aggregation induced by arachidonic acid, ristocetin and bovine factor VIII were not inhibited by EDU-3. The difference between EDU-3 and other Mab directed against the IIb-IIIa GPC is discussed.


Assuntos
Difosfato de Adenosina/farmacologia , Anticorpos Monoclonais , Epinefrina/farmacologia , Glicoproteínas/imunologia , Agregação Plaquetária/efeitos dos fármacos , Animais , Focalização Isoelétrica , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Glicoproteínas da Membrana de Plaquetas
20.
Immunol Lett ; 57(1-3): 101-3, 1997 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-9232433

RESUMO

CD148 is a new cluster of differentiation defined in the VI International Workshop on Leucocyte Differentiation Antigens. It has been identified as the hematopoietic form of a formerly described membrane protein tyrosine phosphatase called HPTP eta/ DEP-1. Previous data have demonstrated that this molecule is able to give rise to [Ca2+]i increase. In the present work we show its capability to induce protein tyrosine phosphorylation in human lymphocytes in spite of its intrinsic protein tyrosine phosphatase activity. The induction of kinase activity suggests the involvement of some protein tyrosine kinase based signaling pathway. The activation of this postulated kinase could be carried out through a direct association or via an adapter molecule.


Assuntos
Antígenos CD/metabolismo , Linfócitos/metabolismo , Proteínas Tirosina Fosfatases/metabolismo , Tirosina/metabolismo , Humanos , Antígenos Comuns de Leucócito/metabolismo , Linfócitos/enzimologia , Fosforilação , Proteínas Tirosina Fosfatases Classe 3 Semelhantes a Receptores , Especificidade por Substrato
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA