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1.
Am J Transplant ; 12(6): 1541-50, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22390302

RESUMEN

The use of uncontrolled deceased donors after cardiac arrest (uDDCA) has been developed in France to compensate for organ shortage. The quality of these kidneys remains unclear. We analyzed kidney graft function and histology from 27 uDDCA and compared them with kidneys from 30 extended criteria donors (ECD) and from 24 simultaneous pancreas kidney (SPK) donors as a control group of optimal deceased donors. Kidneys from ECD and SPK donors were preserved by static cold storage while kidneys from uDDCA were preserved by pulsatile perfusion. The uDDCA graft function at 3 years posttransplantation (estimated with MDRD and measured with inulin clearance) did not differ from that of the ECD group (eGFR 44.1 vs. 37.4 mL/min/1.73 m(2) , p = 0.13; mGFR 44.6 vs. 36.1 mL/min/1.73 m(2) , p = 0.07 in the uDDCA and ECD groups, respectively). The histological assessment of 3-month and 1-year protocol biopsies did not show differences for interstitial lesions between the uDDCA and ECD grafts (IF score at M3 was 30 vs. 28% and at M12 36 vs. 33%, p = NS). In conclusion, the results at 3 years with carefully selected and machine-perfused uDDCA kidneys have been comparable to ECD kidneys and encourage continuation of this program and development of similar programs.


Asunto(s)
Supervivencia de Injerto , Trasplante de Riñón , Calidad de Vida , Donantes de Tejidos , Resultado del Tratamiento , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad
2.
Clin Nutr ; 25(1): 75-81, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16356596

RESUMEN

BACKGROUND & AIMS: Renal impairment is a documented complication in long-term parenteral nutrition (LTPN) patients. However, the aetiologies have remained elusive. The aim of this study was to evaluate the impact of parenteral nutrition, digestive status, and hydration level on renal function in LTPN patients. METHODS: In a prospective study of 40 LTPN patients, renal function and hydration level were assessed by measurement of inulin and creatinine clearances, plasma creatinine, urea, aldosterone and renin and urinary sodium/potassium ratio. Patients were assigned to one of two groups according to their inulin clearance (normal = Group 1, 20% decrease or more = Group 2). RESULTS: Of the patients, 52.5% (21/40) had a decrease in glomerular filtration rate (-38 +/- 15%), with age taken into consideration. Patient characteristics, parenteral nutrition composition or duration and intestinal status were not different between the two groups. Urologic or nephrologic diseases were more frequent in Group 2 patients. Moreover, in Group 2 patients, a urinary sodium/potassium excretion ratio of less than 1 in 8/21 patients and plasma renin (316 +/- 298 vs. 86 +/- 53% of normal value) and aldosterone (291 +/- 464 vs. 58 +/- 36 pmol/l) that were significantly higher than in Group 1 patients suggested a hypovolemic component. CONCLUSION: Decreased renal function is frequent (52.5%) in LTPN patients. A volemic component was associated in more than 70% of them. An elevation of serum creatinine or an inversion of the urinary Na/K ratio requires an evaluation of hydration equilibration and an oral rehydration and a modification in parenteral nutrition formulation.


Asunto(s)
Deshidratación/fisiopatología , Riñón/efectos de los fármacos , Riñón/fisiología , Nutrición Parenteral/efectos adversos , Adulto , Anciano , Enfermedad Crónica , Creatinina/sangre , Femenino , Tasa de Filtración Glomerular , Humanos , Inulina/metabolismo , Riñón/patología , Pruebas de Función Renal , Masculino , Persona de Mediana Edad , Potasio/orina , Estudios Prospectivos , Sodio/orina
3.
Clin Pharmacol Ther ; 31(6): 770-4, 1982 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-6280919

RESUMEN

A 1-mg/kg IV bolus injection and a 150-mg (one tablet) oral dose of ranitidine were given to seven normal subjects. At least 1 wk separated the two doses. Ranitidine disappeared from plasma with a half-life of about 2.5 hr. Half of the oral dose was effectively absorbed and half of the absorbed amount was found unchanged in urine. Total body clearance was 10.1 ml/min/kg. Urinary clearance was the same after oral and intravenous doses (6.4 and 6.9 ml/min/kg, P greater than 0.10). Intravenous ranitidine kinetics included three phases, with a central distribution volume of 0.2 l/kg and a total distribution volume of 1.2 l/kg. Absorption kinetics were apparently order zero: of the 150-mg dose, 75 mg was absorbed during 5 hr at a constant rate of 15 mg/hr.


Asunto(s)
Furanos/metabolismo , Administración Oral , Adulto , Femenino , Furanos/administración & dosificación , Furanos/sangre , Semivida , Humanos , Inyecciones Intravenosas , Cinética , Masculino , Modelos Biológicos , Ranitidina
4.
Clin Pharmacol Ther ; 34(5): 667-72, 1983 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-6313275

RESUMEN

The effects of moderate to severe renal impairment on kinetics of the H2-blocker ranitidine were investigated in 16 patients divided into two groups. Mean inulin clearance (ClIn) was 35 +/- 18.3 ml/min/1.73 m2 in group I and 7.4 +/- 3.5 ml/min/1.73 m2 in group II. Each patient received a single 150-mg oral dose of ranitidine. Values determined were maximum plasma concentration (MC) and time of occurrence, AUC, elimination t 1/2 (t 1/2 beta), total amount of unchanged ranitidine recovered in urine, and ranitidine renal clearance (ClR). MC values were higher and longer delayed than values reported in subjects with normal renal function. The t 1/2 beta was longer in group I and group II and correlated with the degree of renal impairment. The amount of ranitidine excreted within the first 24 hr decreased (18% of the dose in group I and 6% of the dose in group II), and ClR correlated strongly with ClIn, indicating that the observed changes in ranitidine kinetics are mainly related to changes in its renal excretion.


Asunto(s)
Enfermedades Renales/metabolismo , Ranitidina/metabolismo , Adulto , Anciano , Femenino , Humanos , Pruebas de Función Renal , Cinética , Masculino , Persona de Mediana Edad
5.
Am J Hypertens ; 4(12 Pt 1): 955-8, 1991 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-1815653

RESUMEN

This study was performed to assess changes in renal function accompanying cardiovascular responses to mental stress. Glomerular filtration rate (GFR, inulin clearance), renal plasma flow (RPF, PAH clearance), filtration fraction (FF), sodium excretion, and segmental sodium tubular reabsorption (lithium clearance) were measured in 15 normal volunteers during rest and stress. The psychological stress test used is based on a computerized version of the Stroop word color conflict test. Stress induced a significant (P less than .05) and sustained increase in blood pressure and heart rate. During stress, GFR and RPF did not change whereas FF increased significantly (P less than .05) and sodium excretion tended to decrease. The decrease in sodium excretion was due to a significant (P less than .05) increase in proximal reabsorption, which may be mediated by renal hemodynamic changes. The observed significant increase in FF suggests an increase in postglomerular arteriolar resistances, which may account for the increase in proximal sodium reabsorption through an alteration in peritubular Starling forces. In the long run, the stress-associated increase in sodium reabsorption may contribute to the development of hypertension.


Asunto(s)
Túbulos Renales/fisiología , Estrés Psicológico/fisiopatología , Adulto , Presión Sanguínea/fisiología , Fenómenos Fisiológicos Cardiovasculares , Sistema Cardiovascular/efectos de los fármacos , Femenino , Tasa de Filtración Glomerular/efectos de los fármacos , Frecuencia Cardíaca/fisiología , Hemodinámica/efectos de los fármacos , Hemodinámica/fisiología , Humanos , Hipertensión/etiología , Insulina/farmacocinética , Túbulos Renales/efectos de los fármacos , Túbulos Renales/metabolismo , Litio/farmacocinética , Masculino , Tasa de Depuración Metabólica/fisiología , Persona de Mediana Edad , Sodio/orina
6.
J Appl Physiol (1985) ; 66(2): 792-9, 1989 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-2708208

RESUMEN

To investigate the effects of lower body positive pressure (LBPP) on kidney function while controlling certain cardiovascular and endocrine responses, seven men [35 +/- 2 (SE) yr] underwent 30 min of sitting and then 4.5 h of 70 degrees head-up tilt. An antigravity suit was applied (60 Torr legs, 30 Torr abdomen) during the last 3 h of tilt. A similar noninflation experiment was conducted where the suited subjects were tilted for 3.5 h. To provide adequate urine flow, the subjects were hydrated during the course of both experiments. Immediately after inflation, mean arterial pressure increased by 8 +/- 3 Torr and pulse rate decreased by 16 +/- 3 beats/min. Plasma renin activity and aldosterone were maximally suppressed (P less than 0.05) after 2.5 h of inflation. Plasma vasopressin decreased by 40-50% (P less than 0.05) and plasma sodium and potassium remained unchanged during both experiments. Glomerular filtration rate was not increased significantly by inflation, whereas inflation induced marked increases (P less than 0.05) in effective renal plasma flow (ERPF), urine flow, osmolar and free water clearances, and total and fractional sodium excretion. No such changes occurred during control. Thus, LBPP induces 1) a significant increase in ERPF and 2) significant changes in kidney excretory patterns similar to those observed during water immersion or the early phase of bed rest, situations that also result in central vascular volume expansion.


Asunto(s)
Trajes Gravitatorios , Riñón/fisiología , Adulto , Presión Sanguínea , Fenómenos Fisiológicos Cardiovasculares , Diuresis , Electrólitos/sangre , Frecuencia Cardíaca , Hormonas/sangre , Humanos , Masculino , Postura , Circulación Renal
7.
Artículo en Inglés | MEDLINE | ID: mdl-2353026

RESUMEN

In order to assess the main characteristics of the prostaglandin (PG) biosynthesis by the isolated perfused rat kidney, the urinary and venous outputs of PGE2, PGF2alpha, 6-keto-PGF1alpha and of thromboxane (Tx)B2 were followed during 120 min after an equilibration period of 30 min. Single pass kidneys were perfused with a Krebs-Henseleit solution added with Polygeline at a constant flow rate providing a perfusion pressure about 90 mm Hg. From the beginning of the study, major differences could be observed in the renal biosynthetic rate of the 4 PG studied which were mainly excreted into the venous effluent. During the perfusion, urinary and venous outputs of PGE2, PGF2alpha and of TxB2 remained stable whereas those of 6-keto-PGF1alpha sharply increased and were found inversely related to the glomerular filtration rate (r = -0.95; p n 0.001). Finally, the urinary and venous outputs of each of the four PGs studied were found positively related. It is concluded that the isolated perfused rat kidney is a valuable preparation for studying the biosynthesis of PGs and that, at least in thi model, the urinary excretion of PGs is a good index of their renal synthesis.


Asunto(s)
Riñón/metabolismo , Prostaglandinas/biosíntesis , Animales , Dinoprost/biosíntesis , Dinoprost/sangre , Dinoprost/orina , Dinoprostona/biosíntesis , Dinoprostona/sangre , Dinoprostona/orina , Técnicas In Vitro , Masculino , Perfusión , Prostaglandinas F/biosíntesis , Prostaglandinas F/sangre , Prostaglandinas F/orina , Ratas , Ratas Endogámicas , Tromboxano B2/biosíntesis , Tromboxano B2/sangre , Tromboxano B2/orina
8.
Fundam Clin Pharmacol ; 1(3): 225-32, 1987.
Artículo en Inglés | MEDLINE | ID: mdl-3428842

RESUMEN

The effects on magnesium excretion of 4 short-term diuretic treatments (methyclothiazide 2 mg either alone or associated with increasing doses of triamterene) were evaluated in 8 normal volunteers and compared to spontaneous variations during placebo administration. The thiazide exerted a small but significant magnesuric effect, which was prevented only by the lowest dose (25 mg) of triamterene. Larger doses had no protective effect on thiazide-induced magnesuria. Independently of their absolute effects on magnesium excretion, all diuretics impaired the normal ability of the kidneys to compensate fully for the expected changes in magnesium reabsorption induced by extracellular volume contraction.


Asunto(s)
Benzotiadiazinas , Magnesio/orina , Inhibidores de los Simportadores del Cloruro de Sodio/efectos adversos , Triantereno/uso terapéutico , Adulto , Diuréticos , Interacciones Farmacológicas , Humanos , Masculino , Triantereno/administración & dosificación
9.
JPEN J Parenter Enteral Nutr ; 24(4): 234-9, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10885718

RESUMEN

BACKGROUND: Long-term parenteral nutrition (LTPN) has been shown to induce renal impairment and bone demineralization. However, the mechanism of both injuries has not been clarified. METHODS: This prospective study was performed in 16 patients with short bowel syndrome, aged 28 to 63 years, who had received LTPN for 31 +/- 7 months. Urinary excretion of electrolytes were measured before (diurnal, 12 hours) and during (nocturnal, 12 hours) parenteral nutrition. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were measured in the morning after the nutritional bag supply. RESULTS: Mean GFR was 86 +/- 7 mL/min/1.73 m2 and ERPF was 412 +/- 31 mL/min/1.73 m2. Decreased GFR was present in 9 patients. There was no relation between renal function and age or the duration of LTPN. Urine volume and excretion of urea, creatinine, sodium, magnesium, and phosphate but not potassium increased significantly in nocturnal urine compared with diurnal urine. On the basis on 24-hour calciuria, 7 patients were normocalciuric (NCa) whereas 9 were hypercalciuric (HCa). Both had excessive nocturnal calciuria, but only the HCa group had diurnal hypercalciuria, the calcium supply being identical. Bone mineral density (BMD) was slightly, although not significantly, higher in NCa group, but in all patients BMD correlated significantly with calciuria. Serum parathyroid hormone and vitamin D were not different in the two groups. CONCLUSIONS: In patients receiving LTPN, renal function is frequently impaired, by a mechanism which remains unclear. In nocturnal cyclic mode of nutrition, urinary volume and electrolyte excretion occurred predominantly during the infusion, but some patients have diurnal hypercalciuria. In these patients a defect in renal calcium reabsorption or more likely the inability of bone to retain the infused calcium may be responsible for bone demineralization.


Asunto(s)
Calcio/metabolismo , Electrólitos/orina , Riñón/fisiopatología , Nutrición Parenteral/efectos adversos , Adulto , Calcificación Fisiológica , Calcio/orina , Ritmo Circadiano , Femenino , Tasa de Filtración Glomerular , Humanos , Pruebas de Función Renal , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Síndrome del Intestino Corto/terapia , Factores de Tiempo , Urinálisis
10.
Clin Nephrol ; 52(4): 210-7, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10543323

RESUMEN

AIM: Membranous nephropathy in adults causes 20% of nephrotic syndromes. Spontaneous outcome of this glomerulopathy is difficult to evaluate from clinical and histological data. Some patients can achieve complete remission, while others develop progressive renal failure. In this study we assessed alpha-smooth muscle actin (alpha-SMA) expression in renal interstitial myofibroblasts as a marker to predict the outcome of membranous nephropathy. PATIENTS AND METHODS: Renal function tests in tandem with alpha-SMA immunolabelling were performed on 25 patients with a mean follow-up of 7.2+/-5.6 years. The intensity of interstitial alpha-SMA (ialpha-SMA) immunostaining was compared to changes in glomerular filtration rate (GFR) evaluated by inulin clearance, between the time of diagnosis (GFR1) and the end of follow-up (GFR2). RESULTS: A significant correlation (r = 0.62, p<0.001) was found, between the intensity of interstitial myofibroblasts, immunolabeling and GFR at the end of follow-up. Moreover, the annual GFR variation and the annual percentage of GFR variation were correlated to interstitial myofibroblast labeling (respectively r = 0.62, p<0.001; r = 0.67, p<0.001). In addition, the importance of proteinuria, initial GFR impairment and fibrosis were confirmed as prognostic criteria. CONCLUSION: This study strongly shows that ialpha-SMA expression is a useful and early prognostic marker in the evolution of membranous nephropathy.


Asunto(s)
Actinas/metabolismo , Glomerulonefritis Membranosa/metabolismo , Adulto , Biomarcadores/análisis , Biopsia , Femenino , Tasa de Filtración Glomerular , Glomerulonefritis Membranosa/diagnóstico , Humanos , Técnicas para Inmunoenzimas , Glomérulos Renales/patología , Masculino , Pronóstico
11.
Arch Mal Coeur Vaiss ; 96(7-8): 788-91, 2003.
Artículo en Francés | MEDLINE | ID: mdl-12945225

RESUMEN

The parallel investigation of the renal and cardiac complications of recent and never treated systemic hypertension has only rarely been undertaken. The aim of this study was to define the renal function of never treated hypertensive subjects, separated into white coat hypertensives (HTbb: n = 19, BP at consultation 153/97 mmHg) or permanent hypertensives (HT: n = 49, BP at consultation 169/104 mmHg) as a function of their 24 hour BP. Their renal functions were then compared with those of normotensive subjects (NT: n = 10). The 68 hypertensive subjects seen consecutively underwent renal function investigation (DFG: glomerular filtration rate, DPR: renal plasmatic debit, and muAlb: microalbuminuria over 24 hours), and myocardial echography (measurement of the left ventricular mass index, IMVG). The white coat hypertensives had a normal renal function, while the permanent hypertensives had a significant decrease in DPR and a significantly higher muAlb compared to the normotensives. Compared to the white coat hypertensives, the permanent hypertensives had a significantly lower DFG and DPR, as well as a higher muAlb and IMVG. In all the hypertensives (white coat and permanent) the 24 hour systolic BP was significantly correlated with muAlb (r = 0.51, p < 0.001), filtration fraction (r = 0.30, p < 0.05), and IMVG (r = 0.52, p < 0.001). The renal and myocardial parameters were not significantly correlated. In conclusion, there seems to be a continuum between the level of ambulatory BP and the effect on target organs without a parallel progression of the renal and myocardial effects. From a practical point of view, only ambulatory BP measurement allows differentiation of permanent hypertensives who have a very early renal and/or myocardial effect, while white coat hypertensives are spared.


Asunto(s)
Cardiomiopatías/complicaciones , Hipertensión/complicaciones , Enfermedades Renales/etiología , Enfermedades Renales/patología , Adulto , Presión Sanguínea , Progresión de la Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo
12.
Arch Mal Coeur Vaiss ; 79(6): 767-72, 1986 Jun.
Artículo en Francés | MEDLINE | ID: mdl-3099691

RESUMEN

Renal insufficiency is the most frequent complication of malignant hypertension (MHT). The initiation of effective hypotensive treatment is generally followed by a rapid improvement of renal functions, but the long-term evolution has been only rarely studied. A group of 30 patients was retrospectively selected on the following criteria: Malignant hypertension: mean DBP 138 +/- 20 mmHg, hypertensive retinopathy stage III-IV; Early renal insufficiency: mean Inulin clearance (CIN) 66 +/- 26 ml/min, mean PAH clearance (CPAH) 364 +/- 161 ml/min; Clinical and functional follow-up ranging from 5 to 18 years. Among these patients, two groups were defined according to the quality of BP control: good or fair responders (GR) with a DBP always less than 110 mmHg, poor responders (PR) with a DBP occasionally greater than or equal to 110 mmHg. The results show in the two groups an improvement of CIN at 3 years, followed by a stabilization then a decrease after the 6th year. However the early improvement is significantly lower in PR. Despite similar initial values (GR = 54.7 +/- 31.3; PR = 51.4 +/- 13.2), CIN remains always lower in PR (at 9 years = GR 72.4 +/- 30.6; PR 56.0 +/- 19.8). During the first 3 years, CPAH increases in GR, whereas it decreases in PR, resulting in significantly different values at 3 years. At 9 years, CPAH remains improved in GR (329.1 +/- 109.3 vs 281.7 +/- 173.8 initially) but decreased in PR (256.0 +/- 166.9 vs 307.3 +/- 119.5 initially). The parallel improvement of CIN and CPAH in GR confirms a favorable effect of BP control on early vascular lesions.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Antihipertensivos/administración & dosificación , Hipertensión Maligna/fisiopatología , Riñón/fisiopatología , Adulto , Quimioterapia Combinada , Femenino , Estudios de Seguimiento , Tasa de Filtración Glomerular , Humanos , Hipertensión Maligna/tratamiento farmacológico , Inulina , Riñón/irrigación sanguínea , Masculino , Persona de Mediana Edad , Ácido p-Aminohipúrico
13.
Arch Mal Coeur Vaiss ; 80(6): 870-4, 1987 Jun.
Artículo en Francés | MEDLINE | ID: mdl-2959232

RESUMEN

The influence of a new ACEI, Ramipril (R) on renal handling of UA was investigated. 13 hypertensives with normal renal function received either R (10 mg p.o.) or placebo (P). Arterial pressure (AP), GFR (Inulin clearance), Renal Plasma Flow (RPF, PAH clearance), UA urinary excretion (UAV) and fractional clearance (FeAU: UA clearance/GFR) were studied for seven hours after drug administration. GFR remained stable in all cases. R had no effect on sodium excretion rate. Compared to P, R significantly increased UAV by 25 p. 100, FeAU by 32 p. 100, RPF by 26.5 p. 100 and decreased mean arterial pressure (MAP) by 10 p. 100. ACE activity was maximally suppressed at 2 hours. More than 80 p. 100 of the maximal changes in UAU and FeAU were observed within the first two hours, while a progressive increase in RPF up to the fifth hour, and a progressive fall in MAP up to the fourth hour was evident. Except for PAM, all these changes were still present at the end of the study (seventh hour). In conclusion, Ramipril increases the fractional excretion of uric acid. This effect is observed independently of any change in sodium balance and preceeds by two to three hours the changes in renal hemodynamics. The simultaneous changes in FeAU and in ACE activity indicate that the effect on uric acid excretion is presumably due to the fall in angiotensin concentration.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Compuestos Bicíclicos con Puentes/farmacología , Hidrocarburos Aromáticos con Puentes/farmacología , Riñón/metabolismo , Ácido Úrico/metabolismo , Presión Sanguínea/efectos de los fármacos , Compuestos Bicíclicos con Puentes/uso terapéutico , Humanos , Hipertensión/tratamiento farmacológico , Ramipril , Factores de Tiempo
14.
Arch Mal Coeur Vaiss ; 84(8): 1195-9, 1991 Aug.
Artículo en Francés | MEDLINE | ID: mdl-1953268

RESUMEN

In this study, the measurement of blood pressure values, glomerular filtration rate (GFR, inulin clearance), renal plasma flow (RPF, PAH clearance), the filtration fraction (GFR/RPF), natiuresis and proximal sodium resorption (measured by lithium clearance), was performed at rest and during a computerised psychological stress test (Stroop word color conflict test) in 12 normotensive and 10 hypertensive subjects. The stress induced in the normotensives induced a significant increase of the filtration fraction and proximal tubule sodium resorption. The hypertensive kidney, submitted to a basal vasoconstriction greater than that of the normotensive kidney, does not react to stress. In the hypertensives, proximal sodium resorption occurs but is not significantly greater than at rest. In the long-term, the increased sodium resorption during stress could contribute to the development and the persistence of essential hypertension.


Asunto(s)
Presión Sanguínea , Tasa de Filtración Glomerular , Hipertensión/fisiopatología , Sodio/metabolismo , Estrés Fisiológico/complicaciones , Adulto , Femenino , Frecuencia Cardíaca , Humanos , Inulina/farmacocinética , Túbulos Renales/metabolismo , Masculino , Tasa de Depuración Metabólica , Persona de Mediana Edad , Natriuresis , Renina/sangre , Ácido p-Aminohipúrico/farmacocinética
15.
Arch Mal Coeur Vaiss ; 83(8): 1237-40, 1990 Jul.
Artículo en Francés | MEDLINE | ID: mdl-2124461

RESUMEN

An increased urinary excretion of thromboxane (Tx)B2 (Geoffroy & al., Hypertension 1986, 4 suppl 3: S37) and an elevated renal sympathetic activity (Sautel & al., Am J Physiol 1988, 255: H736) were simultaneously observed in the developing genetically hypertensive rat of the Lyon strain (LH). In the present work, the relationship between the adrenergic stimulation and prostaglandins (PGs) release was studied using isolated perfused kidney of 8 week-old LH rats and their normotensive controls (LN). Phenylephrine (PHE, 5 - 190 x 10(-8) M) and norepinephrine (NE, 1.2 - 96 x 10(-8) M) were administered in a single pass kidney perfused with a cell free solution and their effects were studied on the renal vascular resistances (RVR) and urinary excretion of TxB2 and 6-keto-PGF1 alpha (6KPGF) measured by specific radioimmunoassays after separation by HPLC. The results (mean +/- SE) obtained before (C) and after PHE and NE perfusions at concentrations: D1 = 31 and 10.5; D2 = 190 and 96 10(-8) M for PHE and NE respectively (* p less than 0.05 ** p less than 0.01 *** p less than 0.001 LH vs LN) were as follows: [table: see text] During the control period, kidneys of LH rats exhibited increased RVR when compared to LN controls but a similar PG excretion. The 2 concentrations of PHE and NE used which produced a similar increase in RVR strikingly stimulated the PG excretion. This effect which was more marked for NE than for PHE did not differ between the 2 strains for 6KPGF but was enhanced for TxB2 in kidney of LH rat.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Hipertensión/genética , Riñón/metabolismo , Prostaglandinas/biosíntesis , Animales , Hipertensión/fisiopatología , Riñón/fisiología , Masculino , Norepinefrina/farmacología , Fenilefrina/farmacología , Prostaglandinas/orina , Ratas , Sistema Nervioso Simpático/fisiopatología , Tromboxano-A Sintasa/metabolismo , Resistencia Vascular/efectos de los fármacos
16.
Ann Biol Clin (Paris) ; 47(6): 346-50, 1989.
Artículo en Francés | MEDLINE | ID: mdl-2528928

RESUMEN

The kidney is the main organ involved in drugs elimination and thereby is particularly liable to their toxic effect. The determination of renal function is thus of importance, before and during treatment with a potentially nephrotoxic drug or during trial of new drugs. In this general review, the main methods to measure renal function are briefly analysed. They consist either of simple dosages in blood and urine which allow to roughly evaluate renal functional value and its variations, or more sophisticated investigations which allow a more precise analysis of various nephron functions: glomerular filtration rate and renal plasma flow with measurement of clearances of exogenous markers, determination of basal or maximal tubular activities. The interest of these specific tests is illustrated by the results of a study performed in patients receiving streptozotocin, an antineoplastic nephrotoxic drug. In conclusion, nephrotoxicity of drugs may be in most cases prevented owing to an accurate knowledge of their pharmacokinetics and of risk factors inherent in patients, and to survey of renal function with suitable methods which may lead to modify drug dosage and/or to choose a therapy considering the own evolution of the disease and the possible occurrence of irreversible renal impairment.


Asunto(s)
Enfermedades Renales/inducido químicamente , Estreptozocina/efectos adversos , Adulto , Creatinina/sangre , Creatinina/orina , Tasa de Filtración Glomerular , Humanos , Enfermedades Renales/sangre , Enfermedades Renales/orina , Persona de Mediana Edad , Estudios Prospectivos , Urea/sangre
17.
Ann Biol Clin (Paris) ; 62(2): 165-75, 2004.
Artículo en Francés | MEDLINE | ID: mdl-15047468

RESUMEN

PURPOSE: To assess inter-assay variation and accuracy of blood creatinine measurements as well as the effect of the standardization of the calibration procedures on inter-assay variation. METHODS: Inter-assay variation and accuracy were assessed using 30 frozen human sera and 3 certified reference materials, which were analysed by 17 creatinine assays (colorimetric: 12, enzymatic: 4, HPLC: 1). Usual calibration procedure was compared with two common calibration procedures using either a reference material (404.1 micromol/L), or secondary sera calibrators (69, 115 et 180 micromol/L). RESULTS: Most of the commercially available methods display inaccuracy, > 10% for creatininemia < 150 micromol/L in most cases. For this concentration range, the mean creatininemia was statistically significantly different as a function of the assay used (p < 0.001). Enzymatic assays produced lower results than colorimetric ones for low creatinine levels but higher results for high creatinine levels. Assays being calibrated according to the manufacturer's recommendations, the median dispersion factor was 14% for the 20 samples between 45 and 150 micromol/L, and 8% for the 10 samples between 250 and 350 micromol/L. The calibration procedure modified inter-assay variation significantly (p < 0.001) but we gained little advantage from both common calibration procedures. A significant decrease of inter-assay variation occurred within each technical group (colorimetric or enzymatic) when a common calibration was performed using calibrators which concentration(s) was(were) close to the concentrations to be measured. CONCLUSIONS: Inter-assay variation is too high to allow prediction of glomerular filtration rate (GFR) or creatinine clearance from serum creatinine level. Our results highlight the interest of a calibration procedure using several concentrations with at least one between 90 and 150 micromol/L. The marketing of such a calibrator should be considered in order to decrease inter-assay variation in the range of creatinine levels which defines a mild chronic renal failure. Such an approach will certainly reduce inter-assay variation only within each technical group but could allow to include technical group as a co-variable in the algorithms developed for predicting GFR or creatinine clearance. A global transferability will certainly need the correlation of all types of creatinine assays versus a definitive method, whom definition remains uncertain.


Asunto(s)
Creatinina/sangre , Análisis Químico de la Sangre/métodos , Análisis Químico de la Sangre/normas , Humanos , Laboratorios/normas , Estándares de Referencia
18.
Arch Pediatr ; 1(3): 273-80, 1994 Mar.
Artículo en Francés | MEDLINE | ID: mdl-7994337

RESUMEN

Assessment of renal function in children raises several difficulties concerning technical and analytical aspects. Renal function parameters are influenced by both age and renal failure. Inulin clearance is the standard method to measure glomerular filtration rate, but it cannot be routinely used. Among other methods, plasma creatinine determination is not reliable to evaluate the level of renal function or to follow the course of renal diseases. Creatinine clearance estimated from calculations such as Schwartz formula does not provide an accurate estimation of the glomerular filtration rate. More precise estimate can be obtained from endogenous creatinine clearance, providing that the measurement is performed accurately. In this paper the authors review these factors and report personal data obtained from 500 children who underwent renal function investigation.


Asunto(s)
Pruebas de Función Renal , Adolescente , Factores de Edad , Niño , Preescolar , Creatinina/farmacocinética , Tasa de Filtración Glomerular , Humanos , Lactante , Recién Nacido , Inulina/farmacocinética , Tasa de Depuración Metabólica
19.
Arch Pediatr ; 4(7): 639-44, 1997 Jul.
Artículo en Francés | MEDLINE | ID: mdl-9295901

RESUMEN

BACKGROUND: Most children with Wilms tumour recover after nephrectomy, chemotherapy and sometimes radiotherapy. It is therefore important to assess their long-term renal function. POPULATION AND METHODS: Thirty-three patients with Wilms tumour experienced unilateral nephrectomy between 1986 and 1993: three were excluded; 23 were staged as grade I, one at grade II, two at grade III and four at grade IV. They were treated with SIOP 6 and SIOP 9 protocols. The results were compared to five controls who underwent unilateral nephrectomy including three for renal trauma. The glomerular filtration rate (GFR) was measured by inulin clearance and the renal plasma flow (RPF) by para-amino-hippuric acid clearance. RESULTS: The mean age at nephrectomy was 3.4 +/- 2.5 years (median: 3, range: 0.2-10.6) and the duration of follow-up was 4.6 +/- 3.1 years (median: 4.5, range: 1-8.5), the GFR was 93 +/- 13 mL/min/1.73 m2 (median: 93, range: 73-130), the RPF was 441 +/- 85 mL/min/1.73 m2 (median: 453, range: 236-650) and the filtrated fraction (FF) was 0.21 +/- 0.03 (median: 0.20, range: 0.18-0.31). The difference in renal function between patients and controls was not significant (GRF: 86 +/- 12 mL/min/1.73 m2, RPF: 486 +/- 185 mL/min/1.73 m2, FF: 0.22 +/- 0.03). The electrolyte reabsorption rate was normal and none of the patients suffered from arterial hypertension. Fourteen children had urinary albumin: creatinine ratio > 2 g/mol. When comparing patients according to the duration of follow-up after nephrectomy (< 4 years vs > 4 years), the renal function was not statistically different. The age at nephrectomy (< 2 years vs > 2 years) did not increase the risk of renal impairment. CONCLUSION: Children with Wilms tumour who were treated with nephrectomy and non-nephrotoxic drugs (actinomycin, vincristine, epiadriamycin) have a good long-term renal outcome. It is speculated that systematic renal investigation should be limited to those children with increased microalbuminuria and/or elevated blood pressure.


Asunto(s)
Pruebas de Función Renal , Neoplasias Renales/cirugía , Nefrectomía , Tumor de Wilms/cirugía , Análisis de Varianza , Niño , Preescolar , Tasa de Filtración Glomerular , Humanos , Lactante , Fosfatos/farmacocinética , Periodo Posoperatorio , Flujo Plasmático Renal , Sodio/farmacocinética
20.
Arch Pediatr ; 5(6): 602-9, 1998 Jun.
Artículo en Francés | MEDLINE | ID: mdl-9759203

RESUMEN

BACKGROUND: Since renal transplantation is known to be the best choice for the growing child with end-stage renal failure, we prospectively evaluated early and late graft function in transplanted children. POPULATION AND METHODS: The study included 78 children (32 girls, 46 boys) 10.4 +/- 0.6 years at the time of transplantation. Renal investigations were performed at 3, 6 and 12 months post-transplantation and yearly thereafter. Inulin clearance was used to evaluate the glomerular filtration rate (GFR), and the reabsorption rates of Na, P and Ca were measured concomitantly. RESULTS: The overall adjusted GFR was approximately 70 mL/min/1.73 m2 and remained unchanged during the first 5 years post-transplantation. In the mean time the absolute GFR increased significantly, suggesting a remaining capacity for compensatory hypertrophy of the transplanted kidney. Renal function was significantly influenced by the number of rejection episodes during the first 2 years post-transplantation but no correlation was found between GFR and the number of HLA mismatches or the use of preemptive transplantation.


Asunto(s)
Trasplante de Riñón , Niño , Femenino , Estudios de Seguimiento , Tasa de Filtración Glomerular , Humanos , Pruebas de Función Renal , Trasplante de Riñón/fisiología , Masculino , Estudios Prospectivos , Resultado del Tratamiento
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