Asunto(s)
Embolia/prevención & control , Endocarditis Bacteriana/cirugía , Femenino , Humanos , MasculinoRESUMEN
Hepatitis C virus (HCV) infection is associated with some B-cell non-Hodgkin lymphoma (B cell-NHLs). Patients with HCV infection frequently show co-infections with GB virus C (GBV-C, formerly known as hepatitis G virus), and some studies have suggested a higher incidence of GBV-C infection in patients with B cell-NHLs. The aim of this study was to prospectively evaluate the association between HCV and/or GBV-C infection and B cell-NHLs in different geographic areas. One hundred thirty-seven lymphoma cases and 125 non-lymphoma matched controls were enrolled in an international case-control study conducted in Switzerland (Bellinzona), Spain (Barcelona) and England (Southampton) on samples collected from 2001 to 2002. In Bellinzona (41 cases and 81 controls), the overall prevalence of HCV was 3.3% (4.9% in NHLs), and the overall prevalence of GBV-C was 24% (22% in NHLs). In Barcelona (46 cases and 44 controls), the prevalence of HCV was 10% (8.7% in NHLs) and the prevalence of GBV-C 20% (13% in NHLs). There was no statistically significant difference in the frequency of both infections between patients with NHL and controls. In Southampton, 50 NHL cases were analysed, none of them was found to be HCV-positive; therefore, no control group was analysed and GBV-C analysis was not performed, too. Both in Bellinzona and in Barcelona, the seropositivity rate was significantly lower for HCV than for GBV-C, suggesting that their transmission can be independent. The incidence of HCV was significantly higher in Barcelona than that in Bellinzona. This study confirmed the existence of marked geographic differences in the prevalence of HCV in NHL but cannot provide any significant evidence for an association between HCV and/or GBV-C and B-cell NHLs.
Asunto(s)
Infecciones por Flaviviridae/epidemiología , Virus GB-C/aislamiento & purificación , Hepatitis C/epidemiología , Hepatitis Viral Humana/epidemiología , Linfoma de Células B/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Antivirales/sangre , Estudios de Casos y Controles , Comorbilidad , Femenino , Infecciones por Flaviviridae/virología , Virus GB-C/inmunología , Anticuerpos contra la Hepatitis C/sangre , Hepatitis Viral Humana/virología , Humanos , Leucemia Linfocítica Crónica de Células B/epidemiología , Masculino , Persona de Mediana Edad , Proyectos Piloto , Prevalencia , Estudios Prospectivos , Estudios Seroepidemiológicos , España/epidemiología , Suiza/epidemiología , Proteínas del Envoltorio Viral/inmunología , Macroglobulinemia de Waldenström/epidemiología , Adulto JovenRESUMEN
AIMS: To assess adherence to medical treatment in patients with heart failure (HF) using a specific questionnaire and measurement of the serum concentration of digoxin. METHODS AND RESULTS: Forty patients with symptomatic HF and a clinical indication for digoxin were included in this pilot study. The assessment of adherence to the medical regime was based on two different methods: (i) the CARDIA-Questionnaire and (ii) the measurement of serum digoxin concentration (SDC) at 1 and 6 months. All patients were placed on digoxin treatment (target SDC 0.6-0.8 ng/mL) at baseline. Poor adherence was defined if the patient self-reported taking < or =75% of the prescribed HF medication or had an SDC < 0.4 ng/mL (subtherapeutic range) at the follow-up visits. During the entire follow-up, the proportion of patients with poor adherence was 15% as assessed by the questionnaire, 20% as assessed by the SDC, and 25% if both methods were combined. CONCLUSION: Although HF is a symptomatic disease, the proportion of patients with poor adherence to the medical regime in our study was high (up to 25%). The objective methodology based on the measurement of the SDC identified a higher number of patients with poor adherence when compared with the CARDIA-Questionnaire.
Asunto(s)
Cardiotónicos/uso terapéutico , Digoxina/uso terapéutico , Insuficiencia Cardíaca/tratamiento farmacológico , Cumplimiento de la Medicación , Anciano , Cardiotónicos/sangre , Digoxina/sangre , Femenino , Conductas Relacionadas con la Salud , Humanos , Masculino , Proyectos Piloto , Estudios Prospectivos , Psicometría , Factores de Riesgo , Encuestas y Cuestionarios , SuizaRESUMEN
BACKGROUND: Due to its strong intra- and inter-individual variability, predicting the ideal erythropoietin dose is a difficult task. The aim of this study was to re-evaluate the impact of the main parameters known to influence the responsiveness to epoetin beta and to test the performance of artificial neural networks (ANNs) in predicting the dose required to reach the haemoglobin target and the monthly dose adjustments. METHODS: We did a secondary analysis of the survey on Anaemia Management in dialysis patients in Switzerland; a prospective, non-randomized observational study, enrolling 340 patients of 26 centres and in order to have additional information about erythropoietin responsiveness, we included a further 92 patients from the Renal Services of the Ente Ospedaliero Cantonale, Bellinzona, Switzerland. The performance of ANNs in predicting the epoetin dose was compared with that of linear regressions and of nephrologists in charge of the patients. RESULTS: For a specificity of 50%, the sensitivity of ANNs compared with linear regressions in predicting the erythropoietin dose to reach the haemoglobin target was 78 vs. 44% (P < 0.001). The ANN built to predict the monthly adaptations in erythropoietin dose, compared with the nephrologists' opinion, allowed to detect 48 vs. 25% (P < 0.05) of the patients treated with an insufficient dose with a specificity of 92 vs. 83% (P < 0.05). CONCLUSION: In predicting the erythropoietin dose required for an individual patient and the monthly dose adjustments ANNs are superior to nephrologists' opinion. Thus, ANN may be a useful and promising tool that could be implemented in clinical wards to help nephrologists in prescribing erythropoietin.
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Anemia/tratamiento farmacológico , Quimioterapia Asistida por Computador/métodos , Eritropoyetina/administración & dosificación , Sistemas Especialistas , Enfermedades Renales/terapia , Redes Neurales de la Computación , Sistemas de Atención de Punto , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anemia/sangre , Anemia/etiología , Simulación por Computador , Sistemas de Apoyo a Decisiones Clínicas , Femenino , Hemoglobinas/análisis , Humanos , Enfermedades Renales/sangre , Enfermedades Renales/complicaciones , Masculino , Persona de Mediana Edad , Modelos Biológicos , Nefrología/métodos , Diálisis Renal , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Suiza , Resultado del TratamientoRESUMEN
BACKGROUND: In a previous study we demonstrated that mild metabolic alkalosis resulting from standard bicarbonate hemodialysis induces hypotension. This study aimed to compare hemodynamic consequences of either a decrease in the dialysate bicarbonate from 32 to 26 mmol/l or an increase in the dialysate calcium of 0.25 mmol/l and to verify whether the calcium shift secondary to alkalemia explains the consequences on blood pressure. METHODS: In this randomized controlled trial with a single-blind, cross-over design, we used dialysis liquids with two different bicarbonate (32 mmol/l in modalities A and C, and 26 mmol/l in modality B) and calcium (1.25 mmol/l in modalities A and B, and 1.50 mmol/l in modality C) concentrations, and in 27 patients, 243 dialysis sessions, compared blood pressure, heart rate and the incidence of hypotension. RESULTS: No significant differences were seen between A and B while an increase in systolic and diastolic blood pressures and a decrease in the incidence of hypotension (10.5 vs. 1.2%, p < 0.05) were documented in C. The subgroup of patients who with A showed a lower mean systolic blood pressure received more angiotensin-converting enzyme inhibitors or angiotensin II type-1 receptor blockers (36 vs. 0%, p<0.05) and in C showed a less important increase in systolic and diastolic pressures, but the incidence of hypotensive episodes between A and B was not significantly different (9.1 vs. 15.1%). CONCLUSIONS: In the present study it was not possible to demonstrate hemo dynamic instability associated with mild metabolic alkalosis. Even in the subgroup showing a lower blood pressure with a higher dialysate bicarbonate, significant hemodynamic or clinical consequences were not noticed. The calcium shift (0.05 mmol/l) related to alkalemia would justify a mean decrease in systolic blood pressure of only about 1 mm Hg.
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Bicarbonatos/farmacología , Hemodinámica/efectos de los fármacos , Diálisis Renal/métodos , Anciano , Anciano de 80 o más Años , Alcalosis/inducido químicamente , Presión Sanguínea , Calcio/farmacología , Femenino , Frecuencia Cardíaca , Soluciones para Hemodiálisis/química , Soluciones para Hemodiálisis/farmacología , Humanos , Hipotensión/inducido químicamente , Masculino , Persona de Mediana EdadRESUMEN
BACKGROUND: Cystatin C is increasingly used to estimate renal function, but its large intraindividual variability limits its practical value. This study aimed at verifying whether the clinical practice of associating cystatin C determination with serum creatinine (Cr) improved the ability of the Cockcroft and Gault formula to estimate creatinine clearance (CrCl). METHODS: It was an observational cross-sectional study of 134 in-patients with mildly impaired renal function. Using the Hoek et al formula (glomerular filtration rate (GFR)/1.73m2 = - 4.32 + 80.35/cystatin C mg/L), multivariate linear regressions (LREG) and artificial neural networks (ANN), we integrated cystatin C in the Cockcroft and Gault formula and analyzed the potential superiority of this procedure by comparing its performance with that of the two algorithms taken separately. RESULTS: The inclusion of cystatin C in the Cockcroft and Gault formula using the data of an LREG (CrCl = 0.371 x (Hoek et al) + 0.589 x Cockcroft and Gault), a simple mean between the two algorithms or ANN ameliorated the CrCl estimation precision allowing an absolute error reduction of approximately 4, 4 and 6%, respectively (relative values 12, 12 and 17%). CONCLUSIONS: Although the combination of the Hoek et al and Cockcroft and Gault formulae using both linear and non-linear mathematical methods allowed a statistically significant reduction in the estimation error generated by Cockcroft and Gault, considering the small impact on the estimation precision and the large intraindividual variation of both cystatin C and Cr, this procedure probably has no clinical relevance.
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Algoritmos , Creatinina/sangre , Creatinina/orina , Cistatinas/sangre , Tasa de Filtración Glomerular , Enfermedades Renales/diagnóstico , Adulto , Anciano , Estudios Transversales , Cistatina C , Femenino , Humanos , Enfermedades Renales/sangre , Enfermedades Renales/orina , Modelos Lineales , Masculino , Persona de Mediana Edad , Redes Neurales de la Computación , Reproducibilidad de los ResultadosRESUMEN
BACKGROUND: It has been claimed that regional citrate anticoagulation (RCA) improves unfavorable calcium and magnesium dependent cellular and humoral events due to blood/dialyzer membrane interactions during hemodialysis (HD). This study aimed to verify whether the favorable effect of RCA on biocompatibility is independent from coagulation pathway modulation. METHODS: A randomized controlled cross-over single blind trial comparing the activity of the coagulation pathway (thrombinantithrombin complexes (TAT), fibrinopeptide A (FPA), prothrombin fragments 1+2 (F 1+2) and D-dimer (DD)), complement activation (C3a) and interleukin-1 beta secretion (IL-1beta) in nine chronic HD patients treated with RCA or heparin. Blood samples were obtained from the arterial (C3a, IL-1beta, TAT, F 1+2, FPA and DD) and venous (TAT, F 1+2, FPA) lines 2 min after starting treatment and repeatedly during the procedure after 15 min (C3a and IL-1beta), 30 min (C3a), 45 (C3a) and 180 min (TAT, F 1+2, FPA and DD). RESULTS: In both treatment protocols significant enhancement was observed in the coagulation activity during the dialysis session, documented by an increase in TAT (p<0.001), F 1+2 (p<0.001) and FPA (p=0.001). Comparing the two anticoagulation modalities, no differences were noticed in the activity of the coagulation pathway, but a significantly higher complement activity (C3a=886 (832-908) vs. 770 (645-857) ng/mL, p<0.05) and lower IL-1beta secretion (235 (206-285) vs. 538 (346-974) pg/mL, p<0.05) was observed in RCA. CONCLUSIONS: Due to an RCA protocol guaranteeing the same extent of anticoagulation activation as standard heparin, we demonstrated that the significantly lower IL-1beta secretion obtained with RCA is independent from the anticoagulation modulation and dissociated from the complement activity.
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Anticoagulantes/uso terapéutico , Coagulación Sanguínea/efectos de los fármacos , Citratos/uso terapéutico , Activación de Complemento/efectos de los fármacos , Interleucina-1/metabolismo , Diálisis Renal , Antitrombina III , Complemento C3a/metabolismo , Fibrinopéptido A/metabolismo , Humanos , Fallo Renal Crónico/sangre , Fallo Renal Crónico/metabolismo , Fallo Renal Crónico/terapia , Fragmentos de Péptidos/sangre , Péptido Hidrolasas/sangre , Precursores de Proteínas/sangre , Protrombina , Método Simple CiegoRESUMEN
BACKGROUND: Artificial neural networks (ANN) represent a promising alternative to classical statistical and mathematic methods to solve multidimensional nonlinear problems. The aim of the study was to verify, by comparing the performance of ANN with that of experienced nephrologists, whether ANN are useful tools in hemodialysis to predict the follow-up (=1 month after the observation used for the prediction) dietary protein intake (PCR), and whether their performance is influenced by the size of the population and by the data pool used to built the model. METHODS: A combined retrospective and prospective observational study was performed in two Swiss dialysis units (84 chronic hemodialysis patients, 500 monthly clinical observations and biochemical test results). Using mathematical models based on linear regressions to evaluate the variables, ANN were built and then prospectively and interinstitutionally compared with the ability of six experienced nephrologists to predict the follow-up PCR. RESULTS: ANN compared with nephrologists gave a more accurate correlation between estimated and calculated follow-up PCR (P < 0.001). The same superiority of ANN was also seen in the ability to detect a follow-up PCR <1.00 g/kg/day expressed as a percentage of correct predictions, sensitivity, specificity, and predictivity. The interinstitutional performance of the ANN is positively influenced by the size and the variability of the population used to build the mathematical model. CONCLUSION: The use of ANN significantly improves the ability of the experienced nephrologist to estimate and to detect an unsatisfactory (<1.00 g/kg/day) follow-up PCR. The size of the population selected to build the ANN is critical for his performance.
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Proteínas en la Dieta/administración & dosificación , Redes Neurales de la Computación , Diálisis Renal , Anciano , Proteínas en la Dieta/metabolismo , Proteínas en la Dieta/farmacología , Relación Dosis-Respuesta a Droga , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Modelos Biológicos , Nefrología/métodos , Estado Nutricional/efectos de los fármacos , Valor Predictivo de las Pruebas , Estudios Prospectivos , Curva ROC , Estudios RetrospectivosRESUMEN
BACKGROUND: Artificial neural networks (ANN) represent a promising alternative to classical statistical and mathematical methods to solve multidimensional non-linear problems. The aim of the study was to compare the performance of ANN in predicting the dialysis quality (Kt/V), the follow-up dietary protein intake and the risk of intradialytic hypotension in haemodialysis patients with that predicted by experienced nephrologists. METHODS: A combined retrospective and prospective observational study was performed in two Swiss dialysis units (80 chronic haemodialysis patients, 480 monthly clinical observations and biochemical test results). Using mathematical models based on linear and logistic regressions as background, ANN were built and then prospectively compared with the ability of six experienced nephrologists to predict the Kt/V and the follow-up protein catabolic rate (PCR) and to detect a Kt/V < 1.30, a follow-up PCR < 1.00 g/kg/day and the occurrence of hypotension. RESULTS: ANN compared with nephrologists gave a more accurate correlation between estimated and calculated Kt/V and follow-up PCR (P<0.001). The same superiority of ANN was also seen in the ability to detect a Kt/V < 1.30, a follow-up PCR < 1.00 g/kg/day and the occurrence of hypotension expressed as a percentage of correct answers, sensitivity, specificity and predictivity. CONCLUSIONS: The use of ANN significantly improves the ability of experienced nephrologists to estimate the Kt/V and the follow-up PCR and to detect a Kt/V < 1.30, a follow-up PCR < 1.00 g/kg/day and the occurrence of intradialytic hypotension.
Asunto(s)
Proteínas en la Dieta , Hipotensión/epidemiología , Redes Neurales de la Computación , Diálisis Renal , Anciano , Femenino , Humanos , Masculino , Valor Predictivo de las Pruebas , Proteínas/metabolismo , Estudios Retrospectivos , Medición de RiesgoRESUMEN
BACKGROUND: The bicarbonate concentration in dialysis fluids for intermittent haemodialysis usually is between 32 and 35 mmol/l. The severity of chronic metabolic acidosis secondary to end-stage renal failure is very variable, however, so that in some patients pre-dialysis acidosis is overcorrected. This study aimed to analyse haemodynamic tolerances to metabolic alkalosis during intermittent haemodialysis. METHODS: In this randomized controlled trial with a single blind, cross-over design, we used dialysis liquids with two different bicarbonate concentrations, 32 (modality A) and 26 (modality B) mmol/l, and in 26 patients, 468 dialysis sessions, compared blood pressure, heart rate, incidence of hypotension and the frequency of corrections required with saline or hypertonic glucose infusions. RESULTS: The results of intradialytic haemodynamic monitoring for modalities A and B, respectively, were: lowest systolic blood pressure 120.8+/-20.8 vs 124.3+/-20.6 mmHg (P < 0.01); mean systolic blood pressure 138.5+/-23.8 vs 144.6+/-24.8 mmHg (P < 0.001); and highest heart rate 73.5+/-12.0 vs 75.8 +/- 12.9 (NS); with modality A, patients had more dialysis sessions with hypotensive episodes (5.55 vs 1.7%, P < 0.05) and required more saline or hypertonic glucose infusions (20.9 vs 13.7% of the dialysis sessions, P < 0.05). CONCLUSIONS: Mild metabolic alkalosis resulting from standard bicarbonate haemodialysis (32 mmol/l) may induce symptomatic hypotension. While normalizing chronic metabolic acidosis is desirable, reducing bicarbonate concentrations should be considered in cases of significant alkalaemia or otherwise untreatable haemodynamic instability.