RESUMEN
OBJECTIVES: [51Cr]CrEDTA is used to measure the Glomerular Filtration Rate (GFR) in different clinical conditions. However, there is no consensus on the ideal number of blood samples to be taken and at what time points to measure its clearance. This study aimed to compare Slope Intercept (SI) and Single-Sample (SS) methods for measuring GFR in patients with solid tumors, stratified by age, GFR, and Body Mass Index (BMI). METHODS: 1,174 patients with cancer were enrolled in this prospective study. GFR was calculated by the SI method using blood samples drawn 2-, 4-, and 6-hours after [51Cr]CrEDTA injection (246-GFR). GFR was also measured using the SI method with samples at 2 and 4 hours (24-GFR) and at 4 and 6 hours (46-GFR), and SS methods according to Groth (4Gr-GFR) and Fleming (4Fl-GFR). Statistical analysis was performed to assess the accuracy, precision, and bias of the methods. RESULTS: Mean 246-GFR was 79.2 ± 21.9 mL/min/1.73 m2. ANOVA indicated a significant difference between 4Gr-GFR and the reference 246-GFR. Bias was lower than 5 mL/min/1.73 m2 for all methods, except for SS methods in subgroups BMI > 40 kg/m2; GFR > 105 or < 45. Precision was adequate and accuracy of 30 % was above 98% for all methods, except for SS methods in subgroup GFR < 45. CONCLUSION: 46-GFR and 246-GFR have high agreement and may be used to evaluate kidney function in patients with solid tumors. Single-sample methods can be adopted in specific situations, for non-obese patients with expected normal GFR.
Asunto(s)
Tasa de Filtración Glomerular , Neoplasias , Humanos , Tasa de Filtración Glomerular/fisiología , Femenino , Masculino , Estudios Prospectivos , Persona de Mediana Edad , Neoplasias/fisiopatología , Neoplasias/sangre , Estudios Transversales , Anciano , Adulto , Radioisótopos de Cromo/farmacocinética , Índice de Masa Corporal , Reproducibilidad de los Resultados , Factores de Tiempo , Adulto Joven , Anciano de 80 o más Años , Valores de Referencia , Factores de EdadRESUMEN
Objectives: To analyze the preoperative variables associated to the postoperative glomerular filtration rate (GFR) outcomes after nephrectomy for benign and malignant conditions, measured by the reference isotopic technique 51Cr-ethylene diamine tetra-acetic (51Cr-EDTA) and to create a model to predict the short-term postoperative GFR. Secondary aim was to evaluate which of the common equations for GFR estimation (Cockcroft-Gault, Modification of Diet in Renal Disease [MDRD] or Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI]) has the best correlation with the 51Cr-EDTA. Methods: Patients undergoing unilateral nephrectomy from 2014 to 2018 were selected. Pre- and postoperative variables were prospectively collected. Univariate and multivariate analyses were done to identify independent risk factors associated with renal function outcomes and to create a model to predict the postoperative GFR. Correlation analyses were performed to evaluate the performance of various serum creatinine-based equations for GFR estimation compared with 51Cr-EDTA. Results: In total, 107 patients were evaluated. After univariate and multivariate analyses, older age (p = 0.008), higher split function of the operated kidney on dimercaptosuccinic acid (DMSA) scintigraphy (p < 0.001), and lower preoperative 51Cr-EDTA (p < 0.001) were independent risk factors for higher GFR decline. Correlation analyses showed that GFR estimated by CKD-EPI equation had the best concordance to GFR measured by 51Cr-EDTA. Conclusions: Based on our findings age, DMSA and lower preoperative 51Cr-EDTA are predictors of postoperative renal function after unilateral nephrectomy. For the assessment of estimated GFR, CKD-EPI equation appears to have the best concordance with 51Cr-EDTA.
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Radioisótopos de Cromo/farmacocinética , Ácido Edético/farmacocinética , Nefrotomía , Insuficiencia Renal Crónica/etiología , Femenino , Tasa de Filtración Glomerular , Humanos , Pruebas de Función Renal , Masculino , Persona de Mediana Edad , Modelos Biológicos , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/fisiopatología , Insuficiencia Renal Crónica/fisiopatología , Factores de RiesgoRESUMEN
BACKGROUND: The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation seems to correct the overdiagnosis of chronic kidney disease (CKD) provided by Modification of Diet in Renal Disease (MDRD) equation. However, this point has not been tested in some ethnic groups. This study investigated the performance of MDRD and CKD-EPI equations in South Brazilian individuals. METHODS: This cross-sectional study included 354 individuals including healthy volunteers, diabetic and non-diabetic individuals with or without CKD. Glomerular filtration rate (GFR) was measured by the 51Cr-EDTA single-injection method (51Cr-GFR). Accuracy (P30), bias, and Bland-Altman agreement plots were evaluated. RESULTS: In the group as a whole, 51Cr-GFR was 87±37 (6-187), CKD-EPI eGFR, 82±30 (6-152), and MDRD eGFR, 77±28 (6-156) mL/min/1.73 m2 (p<0.001 for all comparisons). Analyzing the subset of individuals with 51Cr-GFR <60 mL/min/1.73 m2, P30 values were, respectively, 76% and 84% for MDRD and for CKD-EPI (p<0.001) while for 51Cr-GFR ≥60 mL/min/1.73 m2, P30 values were 57.5% for both equations (p=1.000). For MDRD and CKD-EPI, mean bias were negative for GFRs <60 (-11 vs. -12, p=0.221) and positive for values >60 (16 vs. 9, p<0.001). In multivariate analysis, absolute bias was unfavorably influenced by measured GFR >60 (for MDRD) and being diabetic or younger (for CKD-EPI). CONCLUSIONS: CKD-EPI reduces GFR underestimation in individuals with GFRs >60, but still presents a quite low accuracy at this GFR range. Moreover, it tends to overestimate GFR in subjects with GFRs <60 mL/min/1.73 m2. CKD stages 1 and 2, diabetes and young age had a negative influence on the performance of the equations.
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Algoritmos , Tasa de Filtración Glomerular/fisiología , Insuficiencia Renal Crónica/fisiopatología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Brasil , Radioisótopos de Cromo/química , Creatinina/sangre , Estudios Transversales , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Índice de Severidad de la Enfermedad , Adulto JovenRESUMEN
Introducción: la hemofilia se define como una anomalía congénita, ligada al cromosoma X. Este hecho determina que se manifieste en varones, mientras que las mujeres son solo portadoras de la enfermedad. Objetivo: evaluar la seguridad y efectividad de la radiosinoviortesis con fosfato crómico marcado con [32P] producido por el Centro de Isótopos, en la sinovitis crónica del paciente hemofílico. Métodos: se incluyeron aquellos pacientes que presentaban más de tres hemartrosis en un mes. Previo consentimiento de los pacientes, se les inyectó 1 mCi del isótopo en la articulación afectada. Fue monitoreada la migración del radiofármaco 10 min después del proceder y en los días 1, 7 y 30 posteriores al tratamiento. También se realizaron estudios hematológicos y citogenéticos antes del tratamiento y un año después de este. Se determinó la frecuencia de sangrado, el dolor y el consumo de factor antihemofílico. Fueron tratadas 10 rodillas en 9 pacientes (hemofilia A, 88,9 por ciento y hemofilia B, 11,1 por ciento). La edad media de los enfermos fue de 36,3 años con un rango entre 23-59 años. Resultados: no se observó fuga articular significativa, ni cambios hematológicos. El estudio cromosómico fue normal en los pacientes estudiados. Antes de la radiosinoviortesis con 32P, los pacientes presentaron una tasa de sangrado de 10,3 veces por mes (rango 7-13, SD ± 2,2). La frecuencia de sangrado después de realizado el proceder disminuyó a 0,8 (P< 0,0001) en los 12 meses posteriores a la radiosinoviortesis (rango 0-4, SD ± 1,23). Conclusiones: la radiosinoviortesis con fosfato crómico es un procedimiento seguro y efectivo en la sinovitis crónica del paciente hemofílico(AU)
Introduction: hemophilia is defined as an X chromosome-linked congenital anomaly that mainly occurs in males whereas females just carry the disease. Objective: to evaluate the safety and the effectiveness of radiosynoviorthesis using 32P chromic phosphate manufactured by CENTIS to treat the chronic synovitis in hemophilic patients. Methods: the patients who presented with more than three hemarthoses in a month were included in the study. After the patients' consent, they were injected 1 mCi of the radionuclide in the affected joint. The migration of the radiopharmaceutical was then monitored 10 minutes after the procedure as well as 1, 7 and 30 days following the treatment. Hematological and cytogenetic studies were also performed before and one year after the treatment. The bleeding frequency rate, pain and the consumption of anti-hemophilic factor were determined. Ten knees from 9 patients received this therapy (hemophilia A in 88.9 percent and hemophilia B in 11.1 percent). The average age of patients was 36.3 years, with a range of 23 to 59 years. Results: there was neither significant joint leakage nor hematological change. The chromosomal study yielded normal values. Before the radiosynoviothesis with 32P, the patients exhibited a bleeding frequency rate of 10.3 times a month (range 7-13, SD ± 2.2), but this rate lowered to 0.8 (P< 0.0001) within the 12 months after the procedure (range 0-4, SD ± 1.23). Conclusions: radiosynoviorthesis with chromic phosphate is a safe effective procedure to treat chronic synovitis in the hemophilic patient(AU)
Asunto(s)
Humanos , Sinovitis/terapia , Hemofilia A/complicaciones , Radioisótopos de Cromo , Estudios de Asociación Genética/métodosRESUMEN
Objetivo: evaluar la fuga de radiactividad de la cavidad articular después de la administración de suspensiones radiomarcadas de Fosfato de Cromo(III) y la probabilidad de inducción de genotoxicidad. Métodos: las suspensiones se obtuvieron según método reportado. Para la evaluación de la fuga articular las suspensiones marcadas se administraron por vía intraarticular en ratas y conejos. El seguimiento se realizó por medición de la actividad retenida por cámara gamma. En los estudios de genotoxicidad se determinó la frecuencia de formación de micronúcleos en eritrocitos de médula ósea de ratas para 2 dosis y 2 tiempos para cada preparado. Resultados: para las suspensiones radiomarcadas en estudio la fuga fue no significativa durante 3 semanas (< 3 por ciento para la marcada con 51Cr y ~5 por ciento con 32P). Para los preparados con 32P e 90Y se observó poca diferencia en la frecuencia de aparición de micronúcleos para el 1-er tiempo, independientemente de las dosis administradas. A tiempos mayores se produjo un incremento en la formación de micronúcleos para las dosis superiores. Conclusiones: se demostró la posibilidad del uso seguro de una suspensión de Fosfato de Cromo(III) marcada con diferentes radionúclidos, en particular que la fuga articular de la suspensión no fue significativa durante 3 semanas y se comprobó las ventajas de tener un preparado con mayor tamaño de partículas. Para las suspensiones marcadas con 90Y y 32P no se producen incrementos en la frecuencia de formación de micronúcleos para una dosis superior en aproximadamente 40 veces a la prevista a utilizar en la clínica(AU)
Objective: to evaluate the leakage of radioactivity after intraarticular administration of radioactive suspensions based on Chromium (III) Phosphate as well as the probability of induction of genotoxic effect. Methods: the suspensions were obtained in line with the published procedure. For the articular leakage evaluation, the radioactive suspensions were intraarticulary administered in rats and rabbits. The radioactivity retention was measured by gamma chamber. A comparison with commercial radiopharmaceutical labeled with 32P was made. The genotoxicity studies determined the frequency of micronuclei formation in the rats´ bone marrow erythrocytes by using 2 doses and 2 time intervals for each preparation. Results: the radiolabeled suspensions under evaluation showed that the leakage was not significant during 3 weeks (<3 percent for the suspension labeled with 51Cr and ~5 percent in the one labeled with 32P) and the advantages of having larger particle preparation were confirmed. For those suspension labeled with 32P and 90Y , no significant difference was seen in the frequency of micronuclei formation for the first time interval, regardless of the administered doses. The micronuclei formation increased for higher doses and at longer time intervals. Conclusions: the results demonstrated the possibility of the safe use of a of Chromium (III) Phosphate suspension labeled with several radionuclides for the treatment of different joints, in particular the leakage was not significant during 3 weeks and the advantages of having a larger particle radiopharmaceutical was confirmed. For the suspensions labeled with 32P and 90Y micronucleus frequency mildly increased with the time and administered doses(AU)
Asunto(s)
Ratas , Conejos , Animales , Radioisótopos de Cromo/efectos adversos , Sinovitis/terapia , Artritis Reumatoide/terapiaRESUMEN
Objetivo: evaluar la fuga de radiactividad de la cavidad articular después de la administración de suspensiones radiomarcadas de Fosfato de Cromo(III) y la probabilidad de inducción de genotoxicidad. Métodos: las suspensiones se obtuvieron según método reportado. Para la evaluación de la fuga articular las suspensiones marcadas se administraron por vía intraarticular en ratas y conejos. El seguimiento se realizó por medición de la actividad retenida por cámara gamma. En los estudios de genotoxicidad se determinó la frecuencia de formación de micronúcleos en eritrocitos de médula ósea de ratas para 2 dosis y 2 tiempos para cada preparado. Resultados: para las suspensiones radiomarcadas en estudio la fuga fue no significativa durante 3 semanas (< 3 por ciento para la marcada con 51Cr y ~5 por ciento con 32P). Para los preparados con 32P e 90Y se observó poca diferencia en la frecuencia de aparición de micronúcleos para el 1-er tiempo, independientemente de las dosis administradas. A tiempos mayores se produjo un incremento en la formación de micronúcleos para las dosis superiores. Conclusiones: se demostró la posibilidad del uso seguro de una suspensión de Fosfato de Cromo(III) marcada con diferentes radionúclidos, en particular que la fuga articular de la suspensión no fue significativa durante 3 semanas y se comprobó las ventajas de tener un preparado con mayor tamaño de partículas. Para las suspensiones marcadas con 90Y y 32P no se producen incrementos en la frecuencia de formación de micronúcleos para una dosis superior en aproximadamente 40 veces a la prevista a utilizar en la clínica
Objective: to evaluate the leakage of radioactivity after intraarticular administration of radioactive suspensions based on Chromium (III) Phosphate as well as the probability of induction of genotoxic effect. Methods: the suspensions were obtained in line with the published procedure. For the articular leakage evaluation, the radioactive suspensions were intraarticulary administered in rats and rabbits. The radioactivity retention was measured by gamma chamber. A comparison with commercial radiopharmaceutical labeled with 32P was made. The genotoxicity studies determined the frequency of micronuclei formation in the rats´ bone marrow erythrocytes by using 2 doses and 2 time intervals for each preparation. Results: the radiolabeled suspensions under evaluation showed that the leakage was not significant during 3 weeks (<3 percent for the suspension labeled with 51Cr and ~5 percent in the one labeled with 32P) and the advantages of having larger particle preparation were confirmed. For those suspension labeled with 32P and 90Y , no significant difference was seen in the frequency of micronuclei formation for the first time interval, regardless of the administered doses. The micronuclei formation increased for higher doses and at longer time intervals. Conclusions: the results demonstrated the possibility of the safe use of a of Chromium (III) Phosphate suspension labeled with several radionuclides for the treatment of different joints, in particular the leakage was not significant during 3 weeks and the advantages of having a larger particle radiopharmaceutical was confirmed. For the suspensions labeled with 32P and 90Y micronucleus frequency mildly increased with the time and administered doses
Asunto(s)
Artritis Reumatoide/terapia , Radioisótopos de Cromo/efectos adversos , Sinovitis/terapiaAsunto(s)
Tasa de Filtración Glomerular/fisiología , Enfermedades Renales/fisiopatología , Modelos Biológicos , Adulto , Anciano , Anciano de 80 o más Años , Brasil/epidemiología , Radioisótopos de Cromo , Enfermedad Crónica , Estudios Transversales , Ácido Edético , Femenino , Humanos , Enfermedades Renales/epidemiología , Masculino , Espectrometría de Masas , Persona de Mediana Edad , Adulto JovenRESUMEN
BACKGROUND: Current data are conflicting about the influence of gender on cystatin C concentrations. The goal of this study was to determine the reference interval for serum cystatin C in normal Brazilian subjects, taking into account the influence of gender. METHODS: Ninety-seven healthy volunteers, aged 18-70 years, 44% male, had glomerular filtration rate (GFR) measured using a (51)Cr-EDTA method and estimated with the Modification of Diet in Renal Disease (MDRD) study equation. Serum cystatin C was measured using a turbidimetric method, and creatinine by the Jaffe method. RESULTS: Mean serum cystatin C was not significantly different between males and females, 0.62 +/- 0.12 vs. 0.65 +/- 0.12 mg/L, respectively (p = 0.26). However, median serum creatinine was significantly higher in men [97 (80-115) vs. 80 (53-88) micromol/L; p = 0.0001]. There were also no significant differences between genders with respect to GFR measured using (51)Cr-EDTA (103 +/- 14 for males and 106 +/- 19 mL/min/1.73 m(2) for females, p = 0.47), and estimated with the MDRD equation (86 +/- 12 vs. 83 +/- 16 mL/min/1.73 m(2), respectively, p = 0.24). CONCLUSIONS: There was no effect of gender on serum cystatin C, as well as on measured and estimated GFR.
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Cistatina C/sangre , Adolescente , Adulto , Anciano , Radioisótopos de Cromo/química , Creatinina/sangre , Ácido Edético/química , Femenino , Tasa de Filtración Glomerular , Humanos , Masculino , Persona de Mediana Edad , Nefelometría y Turbidimetría , Valores de Referencia , Factores SexualesRESUMEN
In this paper results of X-ray and gamma-ray emission probabilities per decay of (51)Cr and (241)Am are presented. The measurements were carried out by means of HPGe planar and REGe spectrometers. The activity of (51)Cr and (241)Am samples was determined in a 4pibeta-gamma coincidence counting system. The HPGe spectrometers were calibrated in a well defined geometry by means of (54)Mn, (55)Fe, (57)Co, (133)Ba, (152)Eu, (166m)Ho and (241)Am sources, previously standardized in a 4pibeta-gamma coincidence system. The MCNP Monte Carlo code was used for simulation of the REGe spectrometer calibration curve, for the selected geometry, and compared with the experimental curve. The experimental results were compared with data from literature.
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Americio/análisis , Radioisótopos de Cromo/análisis , Radiometría/métodos , Espectrometría gamma/métodos , Americio/química , Radioisótopos de Cromo/química , Interpretación Estadística de Datos , Rayos gamma , Semivida , Dosis de Radiación , Rayos XRESUMEN
Plasma clearance of (51)Cr-EDTA ((51)Cr-EDTA-Cl) is an alternative method to evaluate glomerular filtration rate (GFR). This study aimed to investigate the concordance between (51)Cr-EDTA-Cl and renal inulin clearance (In-Cl) in renal transplant recipients as well to determine the repeatability of (51)Cr-EDTA-Cl in kidney donors. Forty four kidney recipients and 22 kidney donors were enrolled. Simultaneous measurements of (51)Cr-EDTA-Cl and In-Cl were performed. A single dose of 3.7MBq of (51)Cr-EDTA was injected and the plasma disappearance curve was created by taking blood samples at 2, 4, 6 and 8 h after injection. Bland and Altman statistical approach was used to quantify the agreement between In-Cl and (51)Cr-EDTA-Cl and to determine the better concordance between all possibilities of measure for the (51)Cr-EDTA-Cl. The mean of In-Cl was 44.5 +/- 17.9 ml/min/1.73 m(2). There was a positive correlation between In-Cl and all possible measurements of (51)Cr-EDTA-Cl. (51)Cr-EDTA-Cl with two samples taken at 4 and 8 h or at 4 and 6 h presenting the narrow limits of agreement and a difference (bias) of 2.8 and 2.7 ml/min, respectively. Two plasma sampling for (51)Cr-EDTA-Cl was a reliable method to measure GFR compared with In-Cl and comprises a suitable method to be used in kidney transplanted patients.
Asunto(s)
Anticoagulantes , Ácido Edético , Pruebas de Función Renal/métodos , Pruebas de Función Renal/normas , Trasplante de Riñón , Adulto , Anticoagulantes/farmacocinética , Radioisótopos de Cromo , Ácido Edético/farmacocinética , Femenino , Tasa de Filtración Glomerular , Humanos , Hipoglucemiantes/farmacocinética , Insulina/farmacocinética , Masculino , Persona de Mediana Edad , Modelos BiológicosRESUMEN
BACKGROUND: Creatinine clearance has been reported to be inaccurate for the estimation of glomerular filtration rate (GFR) in patients with sickle cell anaemia (SCA). Inulin clearance, the reference method for GFR estimation, is impractical for routine use in these patients, and 51Cr-EDTA measurements of the GFR have been rarely reported in this disease. METHODS: In order to obtain reference 51Cr-EDTA values in this disease, we studied 70 patients (40 females; 13-59 years of age, mean: 31.6 years) with homozygous SCA, normal serum creatinine and urinary albumin excretion < or =200 microg x min(-1). All patients were submitted to single-injection 51Cr-EDTA GFR, urinary albumin and haematocrit measurements. 51Cr-EDTA clearances were calculated in different age groups (<20, 20-29, 30-39, 40-49 and >50 years). RESULTS: The mean GFR (+/-standard deviation) obtained for the 70 patients was 111.5+/-23.1 ml x min(-1). Analysis of variance for evaluation of the possible interaction effect between 51Cr-EDTA clearance and sex, age, urinary albumin and haematocrit demonstrated patient age as the only factor influencing 51Cr-EDTA clearance (P < 0.001). The Spearman correlation coefficient showed a significant relationship between 51Cr-EDTA clearance and patient age (r = -0.44, P = 0.0001), but not between 51Cr-EDTA and urinary albumin (r = -0.17, P = 0.1546) or haematocrit (r = 0.079, P = 0.5121). The group aged 20-29 years presented the highest 51Cr-EDTA clearance mean value (126.7+/-20.4 ml x min(-1)), with a progressive reduction in the older groups. CONCLUSION: Young adults with homozygous SCA, normal serum creatinine and micro-albuminuria or normo-albuminuria present supranormal 51Cr-EDTA GFR values. These values rapidly decrease after 30 years of age. We did not find association between urinary albumin and GFR in these patients.
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Anemia de Células Falciformes/diagnóstico por imagen , Ácido Edético , Tasa de Filtración Glomerular , Interpretación de Imagen Asistida por Computador/métodos , Enfermedades Renales/diagnóstico por imagen , Renografía por Radioisótopo/métodos , Adolescente , Adulto , Anemia de Células Falciformes/complicaciones , Radioisótopos de Cromo , Femenino , Humanos , Enfermedades Renales/etiología , Masculino , Persona de Mediana Edad , Radiofármacos , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
OBJECTIVE: To assess the clinical outcome and imaging features of neonatal primary vesicoureteral reflux (VUR). STUDY DESIGN: We prospectively followed 43 infants with primary VUR identified from among a cohort of 497 infants with fetal renal pelvis dilatation. Postnatal renal ultrasound (US) examinations were performed at 5 days and 1, 3, 6, 12, and 24 months of life. Voiding cystourethrography was performed in the neonatal period and repeated at 12 and 24 months when VUR was persistent. Two radioisotopic examinations, including a 99mTc-MAG3 renogram and a plasma clearance of Cr-51 EDTA, were performed in all children with high-grade reflux. RESULTS: The incidence of primary VUR in our study group was 9%. Among the 43 patients followed, 11 (26%) had high-grade (IV-V) VUR and 32 (74%) had low-grade VUR. Resolution of reflux occurred in 2 of 11 (18%) patients with high-grade VUR and in 29 of 32 (90.6%) patients with low-grade VUR at age 2 years (P < .001). At age 2 years, 91% of the low-grade refluxing kidneys were normal on US, compared with only 35% of the high-grade refluxing kidneys. Split renal function was within normal range and single-kidney GFR was significantly increased in 13 of the 17 high-grade refluxing kidneys during follow-up. Furthermore, a strong association between dysplasia on US and poor renal function outcome was found. CONCLUSIONS: In most infants with VUR, the reflux is of low grade and resolves rapidly. In those children with high-grade VUR, spontaneous resolution is rare at age 2 years, but persistent reflux rarely impairs the maturation of renal function.
Asunto(s)
Tasa de Filtración Glomerular , Pelvis Renal/anomalías , Reflujo Vesicoureteral/diagnóstico , Antiinfecciosos Urinarios/uso terapéutico , Profilaxis Antibiótica , Quelantes , Radioisótopos de Cromo/sangre , Ácido Edético , Femenino , Estudios de Seguimiento , Humanos , Lactante , Recién Nacido , Pelvis Renal/diagnóstico por imagen , Masculino , Embarazo , Estudios Prospectivos , Cintigrafía , Radiofármacos , Recuperación de la Función , Índice de Severidad de la Enfermedad , Tecnecio Tc 99m Mertiatida , Trimetoprim/uso terapéutico , Ultrasonografía Prenatal , Vejiga Urinaria/diagnóstico por imagen , Infecciones Urinarias/etiología , Infecciones Urinarias/prevención & control , Reflujo Vesicoureteral/complicaciones , Reflujo Vesicoureteral/cirugíaRESUMEN
Se desarrolló un método de Braquiterapia del espacio subaracnoideo mediante la introducción de un coloide de FostatoCrómico 32P (CROP) en el LCR. Se usaron 90 conejos y los coloides fueron inyectados por vía cisternal, Se comprobó la distribución uniforme y permanencia del CROP en la pia-aracnoides de todo el espacio subaracnoideo y superficie cortical y en el epéndimo ventricular mediante autorradiografías y cortes histológicos con técnica de stripping film. La distribución del 32P en hígado (10 por ciento ), bazo (7 por ciento ) y médula ósea (2 por ciento) y otros órganos no provoca efectos significativos. Se comprueba la tolerancia neurológica perfecta para los coloides de partículas finas de menos de 100 nm (CROP), y la neurotoxicidad de los coloides de partículas grandes mayores a 100 nm.. Con altas dosis los estudios histológicos demostraron la ausencia de edema o de lesiones en células y tejido nerviosos. Hasta 6 meses de observación ninguno de los animales mostró trastornos neurológicos atribuíbles al CROP, ni con la repetición de sus aplicaciones
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Animales , Conejos , Inyecciones Espinales , Braquiterapia , Radioisótopos de Cromo , Espacio Subaracnoideo , Ventrículos Cerebrales/efectos de la radiaciónRESUMEN
The ChrA protein of Pseudomonas aeruginosa plasmid pUM505 confers resistance to chromate. Using an in vitro system, we reported [Alvarez, A.H. et al. (1999) J. Bacteriol. 181, 7398-7400] that chromate resistance is based on energy-dependent efflux of chromate. It is shown here that ChrA determines in vivo efflux of 51CrO(4)(2-) as well. Chromate-loaded cell suspensions of P. aeruginosa strain PAO1 harboring recombinant plasmid pEPL1, which expresses the ChrA protein, showed accelerated efflux of 51CrO(4)(2-) as compared to the plasmidless chromate-sensitive derivative. After a 10-min loading, about 40% of 51CrO(4)(2-) was lost from resistant cells in 15 min. Chromate efflux by resistant cells showed a typical saturation kinetics with an apparent K(m) of 82+/-11 microM chromate and a V(max) of 0.133+/-0.009 nmol chromate min(-1) (mg protein)(-1). Oxyanions sulfate and molybdate inhibited chromate efflux in a concentration-dependent fashion, whereas arsenate and ortho-vanadate had no significant effect on chromate release. Inhibition of chromate extrusion by valinomycin, nigericin, and carbonyl cyanide m-chlorophenylhydrazone, but not by oligomycin or dicyclohexylcarbodiimide, indicated that chromate efflux was driven by the membrane potential.
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Proteínas Bacterianas/genética , Cromatos/farmacocinética , Proteínas de la Membrana/genética , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/metabolismo , Antibacterianos/farmacología , Transporte Biológico/efectos de los fármacos , Transporte Biológico/fisiología , Radioisótopos de Cromo , Farmacorresistencia Bacteriana , Metabolismo Energético/efectos de los fármacos , Regulación Bacteriana de la Expresión Génica , Técnicas In Vitro , Óxidos/metabolismo , Plásmidos , Pseudomonas aeruginosa/efectos de los fármacosRESUMEN
The objective of the present study was to assess intestinal permeability in patients with infection caused by Strongyloides stercoralis. Twenty-six patients (16 women and 10 men), mean age 45.9, with a diagnosis of strongyloidiasis were evaluated. For comparison, 25 healthy volunteers (18 women and 7 men), mean age 44.9, without digestive disorders or intestinal parasites served as normal controls. Intestinal permeability was measured on the basis of urinary radioactivity levels during the 24 h following oral administration of chromium-labeled ethylenediaminetetraacetic acid ((51)Cr-EDTA) expressed as percentage of the ingested dose. The urinary excretion of (51)Cr-EDTA was significantly reduced in patients with strongyloidiasis compared to controls (1.60 +/- 0.74 and 3.10 +/- 1.40, respectively, P = 0.0001). Intestinal permeability is diminished in strongyloidiasis. Abnormalities in mucus secretion and intestinal motility and loss of macromolecules could explain the impaired intestinal permeability.
Asunto(s)
Absorción Intestinal , Strongyloides stercoralis , Estrongiloidiasis/fisiopatología , Adulto , Anciano , Animales , Estudios de Casos y Controles , Radioisótopos de Cromo/orina , Ácido Edético/orina , Femenino , Humanos , Mucosa Intestinal/metabolismo , Masculino , Persona de Mediana Edad , Permeabilidad , Estrongiloidiasis/orinaRESUMEN
The objective of the present study was to assess intestinal permeability in patients with infection caused by Strongyloides stercoralis. Twenty-six patients (16 women and 10 men), mean age 45.9, with a diagnosis of strongyloidiasis were evaluated. For comparison, 25 healthy volunteers (18 women and 7 men), mean age 44.9, without digestive disorders or intestinal parasites served as normal controls. Intestinal permeability was measured on the basis of urinary radioactivity levels during the 24 h following oral administration of chromium-labeled ethylenediaminetetraacetic acid (51Cr-EDTA) expressed as percentage of the ingested dose. The urinary excretion of 51Cr-EDTA was significantly reduced in patients with strongyloidiasis compared to controls (1.60 + or - 0.74 and 3.10 + or - 1.40, respectively, P = 0.0001). Intestinal permeability is diminished in strongyloidiasis. Abnormalities in mucus secretion and intestinal motility and loss of macromolecules could explain the impaired intestinal permeability
Asunto(s)
Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Radioisótopos de Cromo/farmacocinética , Ácido Edético/farmacocinética , Absorción Intestinal , Strongyloides stercoralis , Estrongiloidiasis/parasitología , Estudios de Casos y Controles , Radioisótopos de Cromo , Radioisótopos de Cromo/orina , Ácido Edético , Ácido Edético/orina , Mucosa Intestinal/metabolismo , Permeabilidad , Estrongiloidiasis/diagnósticoRESUMEN
OBJECTIVE: To analyze the role of autonomic function and other possible factors associated with a blunted fall in nocturnal blood pressure. RESEARCH DESIGN AND METHODS: A total of 39 normotensive normnoalbuminuric type 1 diabetic patients were studied. Glomerular filtration rate (51Cr-EDTA technique), extracellular volume (51Cr-EDTA distribution volume), and urinary albumin excretion rate (UAER) (by radioimmunoassay) were measured. The subjects' 24-h ambulatory blood pressure and a 24-h electrocardiogram were recorded simultaneously Heart rate variability was calculated in the time domain for 24 h, in the frequency domain at night, at rest in the supine position, and during tilt. Patients were classified according to diastolic blood pressure (dBP) night/day ratio as dipper patients (< or =0.9) and nondipper patients (>0.9). RESULTS: Nondipper patients presented a higher low-frequency (LF) component (a sympathetic index) and higher LF/high-frequency (HF) ratio during sleep than dipper patients (0.29 +/- 0.12 vs. 0.19 +/- 0.10 normalized units [n.u.], P = 0.008; and 0.98 +/- 0.53 vs. 0.55 +/- 0.45 n.u., P = 0.007, respectively). At rest, the LF component in nondipper patients (0.38 +/- 0.13 n.u.) was higher than in dipper patients (0.27 +/- 0.12 n.u., P = 0.04). After the tilt, nondipper patients did not show an increase in the LF component (P = 0.32), but in dipper patients, the increase was significant (P = 0.001). In both groups, tilting promoted a decrease in the HF component (a parasympathetic index). In a stepwise multiple linear regression analysis, the LF component during sleep and the UAER accounted for 24% of the variability in the dBP night/day ratio. CONCLUSIONS: The predominance of sympathetic activity and increased levels of UAER, although within the normal range, are associated with a blunted fall in nocturnal dBP in normoalbuminuric normotensive type 1 diabetic patients.
Asunto(s)
Albuminuria , Sistema Nervioso Autónomo/fisiopatología , Presión Sanguínea , Diabetes Mellitus Tipo 1/fisiopatología , Neuropatías Diabéticas/fisiopatología , Tasa de Filtración Glomerular , Frecuencia Cardíaca/fisiología , Adulto , Radioisótopos de Cromo/farmacocinética , Diabetes Mellitus Tipo 1/orina , Electrocardiografía , Electrocardiografía Ambulatoria , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis de RegresiónRESUMEN
Trinta e dois cäes submetidos a entubaçäo do ducto torácico e cateterismo bilateral dos ureteres, foram divididos em 3 grupos: A- 4 cäes inoculados com RISA 131 I ou EDTA 51 Cr por via intravenosa ou peri-prostática; B- controle de 8 cäes submetidos a irrigaçäo vesical e prostática com 8 litros de glicina a 1,2 por cento contendo os marcadores radioativos; C- 8 cäes manejados como em B mas sujeitos à RTU da próstata. Os cäes foram acompanhados por 5 horas. A absorçäo de líquido de irrigaçäo foi calculada pelos métodos volumétrico e radioisotópico. Em 5 horas, 97 por cento da RISA 131 I inoculada via intravenosa permanecia neste espaço enquanto apenas 4,6 por cento da injetada no espaço peri-prostático penetrou no compartimento vascular. Para o EDTA 51 Cr, 63,6 por cento da massa inoculada no espaço peri-prostático foi recuperada na urina após 5 horas. O método volumétrico mostrou absorçäo média de 22,7 ml no grupo B e 276 ml no C, e o radioisotópico de 6,3 ml e 165,4 ml, respectivamente. O modelo experimental tem similaridades com o ser humano
Asunto(s)
Animales , Perros , Absorción/fisiología , Ácido Edético/farmacocinética , Radiofármacos/farmacocinética , Glicina/farmacocinética , Prostatectomía/efectos adversos , Radioisótopos de Cromo/farmacocinética , Albúmina Sérica Radioyodada/farmacocinética , Radiofármacos/sangre , Radiofármacos/orina , Glicina/sangre , Glicina/orina , Radioisótopos de Cromo/sangre , Radioisótopos de Cromo/orina , Albúmina Sérica Radioyodada/sangre , Albúmina Sérica Radioyodada/orina , Sistema Linfático/fisiología , Irrigación Terapéutica/efectos adversosRESUMEN
A diarréia persistente, uma condiçäo altamente prevalente em países em desenvolvimento, ocasiona diferentes alteraçöes morfológicas e funcionais na mucosa do intestino delgado, incluindo aumento da permeabilidade a diversas moléculas de prova. Investiga-se, pela primeira vez, a permeabilidade intestinal ao Cr-EDTA em crianças brasileiras com diarréia persistente. O teste de absorçäo do Cr-EDTA foi realizado em 13 crianças controle e em 14 com diarréia persistente, oferecendo-se 50 µCi da substância teste, por via oral, com posterior detecçäo da radioatividade excretada na urina de 24 horas. Houve diferença estatisticamente significante entre o grupo controle (mediana = 1,26 variaçäo = 0,20-3,31 por cento) e com diarréia persistente (mediana = 4,68; variaçäo = 1,40-10,29 por cento). Estabelecendo como padräo de referência de normalidade para o teste de absorçäo urinária de Cr-EDTA os valores mínimo e máximo encontrados no grupo controle, observaram-se que 61,5 por cento dos pacientes com diarréia persistente apresentaram resultado alterados. Nos pacientes com diarréia persistente, a excreçäo do Cr-EDTA foi significativamente maior no grupo que fez uso de dieta à base de hidrolisado protéico e/ou nutriçäo parenteral total, em comparaçäo com o que näo fez, demonstrando sua possível utilidade como indicador de gravidade. Em quatro pacientes com diarréia persistente, o teste foi realizado após a recuperaçäo clínica, sendo que houve queda nos valores de excreçäo em todos os casos. A partir destes dados, pode-se concluir que: 1) na diarréia persistente deve haver alteraçäo na permeabilidade intestinal, que permitiria a entrada aumentada de antígenos alimentares locais, com subseqüente sensibilizaçäo e enteropatia alérgica, contribuindo para a perpetuaçäo do ciclo de diarréia, má absorçäo e desnutriçäo; 2) o teste do Cr-EDTA pode ser útil como indicador de gravidade na diarréia persistente; 3) a alteraçäo da permeabilidade intestinal é um fenômeno secundário na diarréia persistente e, com a reconstruçäo da barreira intestinal, ocorre normalizaçäo da mesma.
Asunto(s)
Humanos , Masculino , Femenino , Lactante , Preescolar , Niño , Diarrea Infantil/metabolismo , Ácido Edético/farmacocinética , Intestino Delgado/metabolismo , Permeabilidad , Absorción , Radioisótopos de Cromo/farmacocinética , Radioisótopos de Cromo/orinaRESUMEN
Persistent diarrhea, a condition highly prevalent in developing countries, causes different morphological and functional alterations of the mucosa of the small intestine, including increased permeability to different test molecules. In the present study we investigate for the first time the intestinal permeability to 51Cr-EDTA of Brazilian children with persistent diarrhea. The test of 51Cr-EDTA absorption was performed in 13 control children and in 14 children with persistent diarrhea by offering 50 microCi of the test substance by the oral route, with later detection of radioactivity excreted in 24-hour urine. There was a statistically significant difference between the control group (median = 1.26; range = 0.20-3.31%) and the group with persistent diarrhea (median = 4.68; range = 1.40-10.29%). Using the minimum and maximum values detected in the control group as the normal reference standard for the test of urinary 51Cr-EDTA absorption, we observed that 61.5% of the patients with persistent diarrhea showed altered results. Among the patients with persistent diarrhea, 51Cr-EDTA excretion was significantly higher in the group fed a protein hydrolysate diet and/or total parenteral nutrition than in the group that did not receive this diet. In four patients with persistent diarrhea, the test was performed after clinical recovery, with a fall in the excretion levels in all cases. On the basis of these data, we may conclude that: 1) in persistent diarrhea there must be alteration of intestinal permeability that might permit an increased entry of local alimentary antigens, with subsequent sensitization and allergic enteropathy, contributing to the perpetuation of the diarrhea, malabsorption and malnutrition cycle; 2) the 51Cr-EDTA test may be useful as an indicator of severity in persistent diarrhea; 3) alteration of intestinal permeability is a secondary phenomenon in persistent diarrhea, with normalization occurring after reconstruction of the intestinal barrier.