RESUMO
The present study investigates the instantaneous coupling among the cardiac, vascular, and respiratory systems, using the heart rate, respiration, and systolic and diastolic blood pressure variability in 12 healthy and 16 vasovagal syncope female subjects during a head-up tilt (HUT) testing protocol at 70° This study contributes to the coupling analysis by using a nonlinear joint symbolic dynamics (JSD) in a high-temporal resolution scheme, based on 5â¯min segments of the time series that are shifted every minute. For each segment, a bivariate JSD matrix was constructed to obtain global and local coupling indices in accordance to Shannon's entropy and the probability of occurrence of various bivariate words, respectively. The novel approach revealed important findings in the coupling dynamics of the systems, thus allowing the detection of group differences during the early orthostatic phase, and during the HUT test, before the occurrence of any pre-syncopal symptoms. In patients, the global indices indicated a significant decrease of cardiovascular coupling, starting at 10â¯min after the tilt-up, manifested by reduced baroreflex sensitivity and cardiorespiratory coupling that was initiated 8â¯min after the onset of the orthostatic phase (OP). A decreased autonomic control on cardiovascular-respiratory couplings was further evidenced by increased alterations of the JSD indices during the OP compared to the supine position in patients compared to controls. Furthermore, findings based on local indices demonstrated that female patients showed reductions and disengagements in cardiovascular (pâ¯<â¯0.001) and cardiorespiratory (pâ¯<â¯0.01) couplings, as early as the first 5â¯min and during the complete OP.
Assuntos
Sistema Cardiovascular/fisiopatologia , Respiração , Estresse Fisiológico , Síncope Vasovagal/fisiopatologia , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Dinâmica não LinearRESUMO
In studies of autonomic regulation during orthostatic challenges only a few nonlinear methods have been considered without investigating the effect of gender in young controls. Especially, the temporal development of the autonomic regulation has not yet been explicitly analyzed using short-term segments in supine position, transition and orthostatic phase (OP). In this study, nonlinear analysis of cardiovascular and respiratory time series was performed to investigate how nonlinear indices are dynamically changing with respect to gender during orthostatic challenges. The analysis was carried out using shifted short-term segments throughout a head-up tilt test in 24 healthy subjects, 12 men (26 ± 4 years) and 12 age-matched women (26 ± 5 years), at supine position and during OP at 70°. The nonlinear methods demonstrated statistical differences in the autonomic regulation between males and females. Orthostatic stress caused significantly decreased heart rate variability due to increased sympathetic activity mainly in men, already at the beginning and during the complete OP, revealed by (a) increased occurrence of specific word types with constant fluctuations as pW111 from symbolic dynamics, (b) augmented fractal correlation properties by the short-term index alpha1 from detrended fluctuation analysis, (c) increased slope indices (21ati and 31ati) from auto-transinformation and (d) augmented time irreversibility indices demonstrating more temporal asymmetries and nonlinear dynamics in men than in women. After tilt-up, both men and women increased their sympathetic activity but in a different way. Time-dependent gender differences during orthostatic challenge were shown directly between men and women or indirectly comparing baseline and different temporal stages of OP. The proposed dynamical study of autonomic regulation has the advantage of screening the fluctuations of the sympathetic and vagal activities that can be quantified by the temporal behavior of nonlinear indices. The findings in this paper strongly suggest the need for gender separation in studies of the dynamics of autonomic regulation during orthostatic challenge.
Assuntos
Sistema Nervoso Autônomo/fisiologia , Caracteres Sexuais , Teste da Mesa Inclinada , Adulto , Algoritmos , Entropia , Feminino , Frequência Cardíaca/fisiologia , Hemodinâmica , Humanos , Masculino , Dinâmica não LinearRESUMO
The cardiovascular and respiratory autonomic nervous regulation has been studied mainly by hemodynamic responses during different physical stressors. In this study, dynamics of autonomic response to an orthostatic challenge was investigated by hemodynamic variables and by diverse linear and nonlinear indices calculated from time series of beat-to-beat intervals (BBI), respiratory cycle duration (RESP), systolic (SYS) and diastolic (DIA) blood pressure. This study included 16 young female patients (SYN) with vasovagal syncope and 12 age-matched female controls (CON). The subjects were enrolled in a head-up tilt (HUT) test, breathing normally, including 5min of baseline (BL, supine position) and 18min of 70° orthostatic phase (OP). To increase the time resolution of the analysis the time series were segmented in five-minute overlapping windows with a shift of 1min. Hemodynamic parameters did not show any statistical differences between SYN and CON. Time domain linear analysis revealed increased respiratory frequency and increased blood pressure variability (BPV) in patients during OP meaning increased sympathetic activity and vagal withdrawal. Frequency domain analysis confirmed a predominance of sympathetic tone by steadily increased values of low over high frequency power in BBI and of low frequency power in SYS and DIA in patients during OP. The nonlinear analysis by symbolic dynamics seemed to be highly suitable for differentiation of SYN and CON in the early beginning of OP, i.e., 5min after tilt-up. In particular the index SYS_plvar3 showed less patterns of low variability in patients reflecting a steadily increase in both BPV and sympathetic activity. The proposed dynamical analysis could lead to a better understanding of the temporal underlying mechanisms in healthy subjects and patients under orthostatic stress.
Assuntos
Postura , Síncope Vasovagal/etiologia , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Modelos Lineares , Adulto JovemRESUMO
Composition and spatial diversity patterns of retained and discarded catches in the deep-water shrimp (family Aristeidae) trawling fishery off Brazil were assessed by observers on-board commercial operations in 2005 and 2006. These trawls caught 19,440 kg and 180,076 individuals of which 76·0 and 65·2%, respectively, were discarded at sea. Finfishes represented 54% of the numerical catch but were almost fully discarded (98%). Crustaceans represented 40% of the numerical catch and were mostly retained (80%). The scarlet shrimp Aristaeopsis edwardsiana comprised approximately half of the retained catch. The remainder of the retained proportion comprised mainly the red giant shrimp Aristaeomorpha foliacea, the alistado shrimp Aristeus antillensis and small quantities of Argentine hake Merluccius hubbsi and gulf hake Urophycis mystacea. Discards comprised 108 species including 72 fish species, 19 crustaceans and 10 cephalopods. The large-scaled lanternfish Neoscopelus macrolepidotus was dominant in the discards, followed by the benthopelagic fishes Monomitopus agassizii, Synagrops bellus, Dibranchus atlanticus and Gadella imberbis and various macrurid species. This fishery was restricted to a limited bathymetric range (700-800 m), where discrete megafauna assemblages exist and may have been significantly affected.
Assuntos
Biota , Pesqueiros , Animais , Brasil , Cefalópodes , Decápodes , PeixesRESUMO
OBJECTIVE: To determine the prevalence of transplants performed with a false-negative cytotoxicity cross-match and to analyze the clinical relevance of alloantibodies (Ab) detected only by flow cytometry (flow). METHODS: We studied 66 patients undergoing kidney transplantation from a cadaveric donor. All patients had a simultaneous negative T+AHG+DTT and B+DTT. Pretransplant sera were retrospectively analyzed by flow cytometry according to an Emory University protocol: (1) T+ and B-: Ab anti-class I; (2) T- and B+: anti-class II; (3) T+B+: anti-class I + II. Chi-square, Fisher exact, Student t test, and Kaplan Meier analyses were employed with significance assigned at P < or = .05. RESULTS: The overall incidence of false-negative cytotoxicity was 33.3% (22/66), namely, 6.1% (n = 4) anti-class I; 9.1% (n = 6) anti-class II; and 18.2% (n = 12) anti-class I + II. Primary nonfunctioning grafts occurred in 6.8% (3/44) and 13.6% (3/22) negative and positive flow patients (two anti-class I + II and one class II; P = .39). The incidence of graft loss in the first year was respectively, 13.6% (6/44) and 18.2% (4/22; two anti-class II and two anti-class I + II; P = .72). Compared to flow-negative grafts, creatinine levels were significantly higher among flow-positive patients at 8 and 12 weeks. One-year graft survivals were 86.4% among negative versus 81.8% for the positive group (P = .67). CONCLUSIONS: We observed that 33% of kidney transplant recipients had low levels of alloantibodies detected only by flow. This single factor was associated with the worst graft function in the first trimester with a suggestion of a higher risk for non-functioning graft.
Assuntos
Isoanticorpos/sangue , Transplante de Rim/imunologia , Cadáver , Citotoxicidade Imunológica , Reações Falso-Negativas , Citometria de Fluxo , Seguimentos , Rejeição de Enxerto/epidemiologia , Sobrevivência de Enxerto/imunologia , Antígenos HLA-D/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Transplante de Rim/mortalidade , Análise de Sobrevida , Doadores de Tecidos , Resultado do TratamentoRESUMO
Cytomegalovirus (CMV) infection is a frequent complication in transplant recipients, causing a high level of morbidity and mortality. We studied 203 consecutive renal transplant recipients performed between January 2000 and December 2001. Patients underwent weekly measurements of CMV pp65 antigen to assess CMV activity from the 4th to the 12th week posttransplantation. The results were reported as number of cells positive for the pp65 antigen among 10(5) granulocytes. In order to define a best cutoff to diagnose CMV disease with desirable sensitivity and specificity, we used a receiver operator characteristics (ROC) curve. The cutoff of four positive cells corresponded to a sensitivity of 93% and specificity of 60% (AUC = 0.87) for the diagnosis of CMV disease. The chosen cutoff for starting antiviral treatment was 10 cells, since this was associated with a sensitivity of 92% and specificity of 70% (AUC = 0.90). In conclusion, the highly sensitive cutoff points for the diagnosis of antigenemia was four cells and 10 cells for initiation of antiviral therapy.
Assuntos
Infecções por Citomegalovirus/diagnóstico , Complicações Pós-Operatórias/virologia , Antígenos Virais/análise , Infecções por Citomegalovirus/epidemiologia , Rejeição de Enxerto/epidemiologia , Humanos , Transplante de Órgãos/efeitos adversos , Fosfoproteínas/análise , Estudos Retrospectivos , Sensibilidade e Especificidade , Proteínas da Matriz Viral/análise , Viremia/epidemiologiaRESUMO
Cytomegalovirus (CMV) infection is the single most frequent infectious complication in renal transplant recipients. The purpose of this study was to analyze the diagnostic efficacy of PCR-RFLP compared to antigenemia for CMV disease (CMVD) in kidney transplant recipients. From November 2001 to February 2002, 19 renal adult transplant recipients were followed with weekly measurements of CMV pp65 antigen to monitor the activity of CMV from the week 4 to 12 posttransplantation. Only 4 (21.1%) patients did not develop viremia during the first 12 posttransplantation weeks. Active infection was observed in 15 patients (78.9%): asymptomatic viremia in 6 (31.6%) and CMVD in 9 (47%). All patients who developed CMVD showed positivity in both methods during the observation period. The number of positive cells ranged from 11 to 292 cells in patients with CMVD and one to eight cells among those with asymptomatic viremia. Both methods revealed 100% sensitivity for CMVD diagnosis. The specificity was 60% for antigenemia and 70% for PCR, with positive predictive values of 60% and 75%, respectively.
Assuntos
Antígenos Virais/sangue , Infecções por Citomegalovirus/epidemiologia , Citomegalovirus/isolamento & purificação , Transplante de Rim/estatística & dados numéricos , Fosfoproteínas/sangue , Proteínas da Matriz Viral/sangue , Doença Aguda , Citomegalovirus/genética , Humanos , Reação em Cadeia da Polimerase/métodos , Polimorfismo de Fragmento de Restrição , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade , Viremia/epidemiologiaRESUMO
Cytomegalovirus (CMV) infection is the single most frequent infectious complication in renal transplant recipients. The aim of this study was to determine the incidence of latent and active infections with CMV during the first 3 months after kidney transplantation. From January 2000 to December 2001, 203 consecutive adult renal transplant recipients underwent weekly measurements of pp65 CMV antigen from the 4th to the 12th posttransplantation week. Latent infection (seropositivity) was found in 92% of the population. Primary infection occurred in 4.9% (10 of 203), among whom 66% were previously seronegative patients. Among the primary infection patients, 70% (7 of 10) developed severe disease. The overall incidence of viremia was 69.5%, being more frequent among cadaver recipients (79% vs 59%; P =.02). The overall incidence of CMV disease was 38.4% (78 of 203) with 24.6% classified as severe disease requiring antiviral therapy. In conclusion, our population showed a high prevalence of latent infection with viremia. Not all patients developed clinical disease. Most subjects experienced a mild spectrum of symptoms, probably due to the prospective search for active infection during the major risk period after kidney transplantation.
Assuntos
Infecções por Citomegalovirus/epidemiologia , Transplante de Rim/estatística & dados numéricos , Adulto , Humanos , Período Pós-Operatório , Estudos RetrospectivosRESUMO
We have determined the number of circulating T, B and natural killer cells in renal transplant recipients in order to detect changes during cytomegalovirus (CMV) infections. Serial blood samples were taken from 61 patients on standard triple immunosuppression therapy (cyclosporin A, azathioprine and prednisone). Using two-color flow cytometry analysis, the absolute number of CD3+, CD4+, CD8+, CD19+, CD3+HLA-DR+ and CD16+56+ cells was determined. Forty-eight patients (78.7%) developed active CMV infection, and all of them subsequently recovered. Twenty of the infected patients (32.8%) presented symptoms compatible with CMV disease during the infectious process. The number of lymphocytes and their main subpopulations were normal before the onset of CMV disease. During the disease there was a decrease followed by a significant increase (P<0.005) in the number of CD3+, CD4+, CD8+ and CD3+HLA-DR+ cells. No significant changes were observed in natural killer cells or B lymphocytes during the disease. We conclude, as observed in all viremic patients recovering from infection, that recovery is associated with an increase in the number of T cell subsets. The monitoring of different lymphocyte subsets along with antigenemia can be extremely useful in the detection of patients at high risk of developing CMV symptoms, allowing the early introduction of antiviral therapy or the reduction of immunosuppression therapy.
Assuntos
Infecções por Citomegalovirus/imunologia , Imunossupressores/uso terapêutico , Transplante de Rim/imunologia , Linfócitos/imunologia , Adolescente , Adulto , Idoso , Análise de Variância , Linfócitos B/efeitos dos fármacos , Linfócitos B/imunologia , Infecções por Citomegalovirus/etiologia , Feminino , Citometria de Fluxo , Humanos , Imunidade Celular , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Ativação Linfocitária/imunologia , Linfócitos/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologiaRESUMO
We have determined the number of circulating T, B and natural killer cells in renal transplant recipients in order to detect changes during cytomegalovirus (CMV) infections. Serial blood samples were taken from 61 patients on standard triple immunosuppression therapy (cyclosporin A, azathioprine and prednisone). Using two-color flow cytometry analysis, the absolute number of CD3+, CD4+, CD8+, CD19+, CD3+HLA-DR+ and CD16+56+ cells was determined. Forty-eight patients (78.7 percent) developed active CMV infection, and all of them subsequently recovered. Twenty of the infected patients (32.8 percent) presented symptoms compatible with CMV disease during the infectious process. The number of lymphocytes and their main subpopulations were normal before the onset of CMV disease. During the disease there was a decrease followed by a significant increase (P<0.005) in the number of CD3+, CD4+, CD8+ and CD3+HLA-DR+ cells. No significant changes were observed in natural killer cells or B lymphocytes during the disease. We conclude, as observed in all viremic patients recovering from infection, that recovery is associated with an increase in the number of T cell subsets. The monitoring of different lymphocyte subsets along with antigenemia can be extremely useful in the detection of patients at high risk of developing CMV symptoms, allowing the early introduction of antiviral therapy or the reduction of immunosuppression therapy
Assuntos
Humanos , Masculino , Feminino , Pré-Escolar , Criança , Infecções por Citomegalovirus , Imunossupressores , Transplante de Rim , Linfócitos B , Brasil , Infecções por Citomegalovirus , Transplante de Rim , Células Matadoras Naturais , Prevalência , Fatores de Risco , Linfócitos TAssuntos
Infecções por Citomegalovirus/fisiopatologia , Sobrevivência de Enxerto , Transplante de Rim/fisiologia , Adulto , Análise de Variância , Antígenos Virais/sangue , Cadáver , Citomegalovirus/isolamento & purificação , Infecções por Citomegalovirus/diagnóstico , Seguimentos , Humanos , Doadores Vivos , Complicações Pós-Operatórias , Período Pós-Operatório , Estudos Retrospectivos , Fatores de Tempo , Doadores de TecidosRESUMO
Immunoblot analysis of sperm protein from several species revealed the presence of polypeptides recognised by anti-Sm sera obtained from patients with systemic lupus erythematosus. Immunoreactive polypeptides in human, bull, mouse and rat sperm were identified as protein B', B and D as compared with the Sm polypeptides of HeLa cells. In the sperm of rooster, the teleost fish Cyprinus carpio and the mussel Choromytilus chorus, the immunoreactive polypeptide profile was more complex. To ascertain the sperm origin of the Sm antigens, immunolocalisation with anti-Sm serum was carried out. The results demonstrated that in all the species studied staining was confined to the sperm nucleus, confirming that some polypeptides of the small nuclear ribonucleoprotein complex are present in the gamete.
Assuntos
Autoantígenos/análise , Núcleo Celular/imunologia , Ribonucleoproteínas Nucleares Pequenas/análise , Espermatozoides/imunologia , Animais , Anticorpos/imunologia , Western Blotting , Bovinos , Núcleo Celular/química , Galinhas , Peixes , Células HeLa , Humanos , Imuno-Histoquímica , Lúpus Eritematoso Sistêmico/imunologia , Masculino , Camundongos , Microscopia Eletrônica , Ratos , Espermatozoides/química , Espermatozoides/ultraestrutura , Proteínas Centrais de snRNPRESUMO
The authors followed up 197 melanotic choroidal lesions (62 categorised as benign naevi, 76 classified as suspicious naevi, 41 diagnosed as dormant melanomas, and 18 categorised as active melanomas) left untreated after their initial clinical documentation. Thirty-nine of these lesions enlarged during a five-year follow-up interval (cumulative proportion of lesions that enlarged = 26.2% by Kaplan-Meier method). Individual clinical parameters predictive of lesion enlargement (p less than 0.01) included larger size of the lesion, especially lesion thickness, presence of retinal detachment, location of the lesion's posterior margin within 2 disc diameters of the optic disc, presence of symptoms, and presence of orange pigment clumps on the lesion's surface. The best combination of these parameters for prediction of lesion enlargement, as identified by multivariate Cox regression analysis, consisted of thickness of the lesion, retinal detachment, and symptoms. The five-year incidence of lesion enlargement for patients with none of these prognostic parameters was 5.8%, while that for patients with all three unfavourable parameters simultaneously was 90.6%.