RESUMEN
In a 56-year-old man with severe familial hypertension and unilateral renal artery stenosis, captopril induced striking changes in the renograms of the affected kidney. After injection of orthoiodohippurate sodium I 131, the uptake phase was unchanged but the later curve showed continuous accumulation. In contrast, the uptake of technetium Tc 99m diethylenetriamine pentracetic acid was abolished. These changes are compatible with a cessation of filtration and maintenance of renal blood flow. After balloon dilatation of the stenosis, the blood pressure became lower, and these changes could no longer be demonstrated. The captopril renogram may provide useful information on the dependency of hypertension on unilateral renal artery stenosis.
Asunto(s)
Captopril , Hipertensión Renovascular/diagnóstico por imagen , Riñón/diagnóstico por imagen , Obstrucción de la Arteria Renal/diagnóstico por imagen , Captopril/farmacología , Tasa de Filtración Glomerular/efectos de los fármacos , Humanos , Hipertensión Renovascular/genética , Radioisótopos de Yodo , Ácido Yodohipúrico , Masculino , Persona de Mediana Edad , Ácido Pentético , Cintigrafía , Tecnecio , Pentetato de Tecnecio Tc 99mRESUMEN
Granular deposits of IgA are known to occur in the walls of superficial vessels in apparently healthy skin of patients with primary IgA nephropathy, Henoch-Schönlein purpura, or alcoholic liver disease, but the specificity of the finding is still a matter of debate. We investigated the disease specificity of these deposits in the skin of patients with kidney and liver diseases. The sensitivity of the finding for the diagnosis of primary IgA was 75%, the specificity was 88%. The sensitivity for the diagnosis of alcoholic liver disease was 71%, but the specificity was only 60%. The specificity for the diagnosis of Henoch-Schönlein purpura, primary IgA nephropathy, or alcoholic disease (in a group of 1,030 patients with various diseases) was 94%. Immunoelectron-microscopic investigation showed the IgA deposits localized within the endothelial cell and in the subendothelial rim.
Asunto(s)
Inmunoglobulina A/metabolismo , Enfermedades Renales/metabolismo , Hepatopatías/metabolismo , Piel/irrigación sanguínea , Capilares/metabolismo , Capilares/patología , Glomerulonefritis por IGA/metabolismo , Glomerulonefritis por IGA/patología , Humanos , Vasculitis por IgA/metabolismo , Vasculitis por IgA/patología , Enfermedades Renales/patología , Hepatopatías/patología , Hepatopatías Alcohólicas/metabolismo , Hepatopatías Alcohólicas/patología , Estudios ProspectivosRESUMEN
To gain insight into the factors involved in the maintenance of sodium balance in patients with chronic renal failure, we studied 10 patients with a creatinine clearance of 11.5 +/- 4.0 ml/min after equilibrium on 20 and 120 mEq of sodium per day. The measurements included blood pressure, plasma volume, blood volume, extracellular fluid volume, plasma renin activity, plasma aldosterone, and plasma norepinephrine. For comparison, eight normal volunteers were studied after equilibration on 20, 200, and 1128 mEq of sodium per day. The latter intake was chosen to match the high sodium intake per residual renal function in the patients. In the patients, equilibrium after raised sodium intake was accompanied by a marked increase in blood pressure and blood volume, a moderate fall in plasma renin activity and levels of aldosterone and norepinephrine, and only little expansion of the interstitial space. The 24-hour creatinine clearance rose by 21.2 +/- 7.2%. Fractional sodium excretion (X 100%) was 5.3 +/- 0.8% during the 120 mEq sodium diet. In the normal volunteers, increasing the sodium intake from 20 to 1128 mEq/day evoked no consistent change in blood pressure but caused a comparable rise in blood volume, considerable suppression of plasma renin activity, aldosterone, and norepinephrine, and a much larger increase in interstitial volume. Their creatinine clearance had risen by 22.4 +/- 6.5%, and their fractional sodium excretion during the 1128 mEq sodium intake was 3.9 +/- 0.2%.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Fallo Renal Crónico/metabolismo , Sodio/administración & dosificación , Adulto , Aldosterona/sangre , Presión Sanguínea , Líquidos Corporales , Creatinina/orina , Femenino , Humanos , Hipertensión/metabolismo , Pruebas de Función Renal , Masculino , Persona de Mediana Edad , Norepinefrina/sangre , Enfermedades Renales Poliquísticas/metabolismo , Renina/sangre , Sodio/orinaRESUMEN
In clearance studies, we analyzed the effect of Ca2+ entry blockade with nitrendipine treatment (20 mg b.i.d. for 4 days) and of converting enzyme inhibition with enalapril treatment (20 mg b.i.d. for 4 days) on renal response to atrial natriuretic factor (ANF) (25 micrograms bolus followed by an infusion of 0.03 microgram/kg/min for 90 minutes) in six healthy volunteers who were taking 300 mmol sodium daily. In a control study ANF was administered without Ca2+ entry blockade or converting enzyme inhibition. Natriuresis rose from 239 +/- 38 to 605 +/- 137 mumol/min in the control study (p less than 0.05), from 330 +/- 53 to 943 +/- 152 mumol/min with Ca2+ entry blockade (p less than 0.05), and from 236 +/- 22 to 344 +/- 39 mumol/min with converting enzyme inhibition (NS). ANF induced a rise in maximal free water clearance, inulin clearance, and in the excretion of multiple electrolytes except potassium. Fractional lithium reabsorption fell. In general, these effects were stronger during Ca2+ entry blockade and blunted during converting enzyme inhibition. p-Aminohippurate clearance tended to decrease during the control study (NS), remained constant during Ca2+ entry blockade, and decreased significantly when ANF was infused during converting enzyme inhibition (p less than 0.05 vs. control and vs. Ca2+ entry blockade study). Blood pressure was lowered by Ca2+ entry blockade and, to a somewhat greater extent, by converting enzyme inhibition, but ANF administration induced no additional fall except for a short-term drop during Ca2+ entry blockade.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Factor Natriurético Atrial/farmacología , Enalapril/farmacología , Riñón/efectos de los fármacos , Nitrendipino/farmacología , Sodio/orina , Adulto , Presión Sanguínea/efectos de los fármacos , Tasa de Filtración Glomerular/efectos de los fármacos , Humanos , MasculinoRESUMEN
We examined the question of whether escape from the sodium-retaining effect of mineralocorticoid involves an increased natriuretic effect of atrial natriuretic factor (ANF). Seven healthy volunteers taking a 170 mmol Na/100 mmol K diet received an intravenous bolus (25 micrograms) followed by a 1-hour infusion (0.02 micrograms/kg/min) of ANF (human ANF-[99-126]) before and after 10 days of 9-fludrocortisone acetate, 0.5 mg b.i.d. Escape was accompanied by an increase in body weight (from 72.2 +/- 12.9 to 74.0 +/- 12.6 kg; p less than 0.05), mean arterial pressure (from 95 +/- 4 to 109 +/- 3 mm Hg; p less than 0.01), plasma ANF (from 9 +/- 2 to 24 +/- 4 pmol/L; p less than 0.01), and inulin clearance (from 124 +/- 9 to 137 +/- 7 ml/min; p less than 0.05). Indexes for renal sodium handling (lithium and free water clearance) were compatible with a decreased "proximal" and an increased "distal" tubular reabsorption fraction. ANF infusion raised inulin clearance comparably before and after escape to 138 +/- 10 and 152 +/- 7 ml/min, respectively, but the natriuretic effect was much larger (p less than 0.05) after escape (from 366 +/- 34 to 1294 +/- 278 mumol/min) than before (from 248 +/- 48 to 630 +/- 124 mumol/min). Indexes for tubular reabsorption were consistent with greater suppression of both "proximal" and "distal" tubular sodium reabsorption by ANF after versus before mineralocorticoid expansion. These results indicate that escape is accompanied not only by a rise in plasma ANF but also by potentiation of the natriuretic effect of ANF.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Factor Natriurético Atrial/farmacología , Riñón/efectos de los fármacos , Mineralocorticoides/farmacología , Sodio/orina , Adulto , Factor Natriurético Atrial/sangre , Presión Sanguínea/efectos de los fármacos , Femenino , Tasa de Filtración Glomerular/efectos de los fármacos , Humanos , Riñón/metabolismo , Masculino , Renina/sangreRESUMEN
In 26 patients with essential hypertension who were on continuous chlorthalidone therapy, 1 and 3 daily doses of propranolol were compared in a crossover study. Plasma propranolol levels and heart rates had larger daily fluctuations on single-dose therapy than on 3 times daily; plasma renin activity was more constant. There was no significant difference in blood pressures. Once-daily propranolol dosage was well tolerated and possibly gave less rise to the troublesome side effect of vivid dreaming.
Asunto(s)
Frecuencia Cardíaca/efectos de los fármacos , Hipertensión/tratamiento farmacológico , Propranolol/uso terapéutico , Adolescente , Adulto , Presión Sanguínea/efectos de los fármacos , Clortalidona/uso terapéutico , Depresión Química , Sueños , Esquema de Medicación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Propranolol/efectos adversos , Propranolol/farmacología , Renina/sangreRESUMEN
The antihypertensive effects of atenolol and propranolol were compared in a double-blind crossover study of 19 patients with essential hypertension (World Health Organization, I and II) who were receiving long-term diuretic treatment (chlorthalidone, 50 mg daily) during the study. After a 3-wk placebo period, a beta-adrenergic antagonist was administered once daily (atenolol, 50 mg daily, or propranolol, 80 mg daily) for a week. If the MAP was more than 108 mm Hg at the end of the week, dosage of the beta-blocker was doubled the following week; when necessary, doubling was repeated to a maximum dose of 640 mg propranolol and 400 mg atenolol daily. Fifty milligrams atenolol had a greater effect than 80 mg propranolol and was as effective as 160 mg propranolol. The dose-response curve flattened off after 160 mg propranolol and 50 mg atenolol daily. The two highest doses of atenolol lowered MAP more than the highest doses of propranolo. Heart rate slowing was the same for both drugs and did not correlate with the fall in blood pressure. PRA was suppressed by all doses of propranolol, whereas atenolol suppressed PRA only at the 2 highest doses, (200 and 400 mg daily). With the lower propranolol doses, the percent MAP change correlated weakly with the percent PRA change (80 mg--r = 0.41, p less than 0.1; 160 mg--r = 0.64, p less than 0.05). Side effects were minimal, and were noted only with 640 mg propranolol; with this exception, the percentage of patients with no complaints rose when placebo was replaced by beta-blockers.
Asunto(s)
Atenolol/farmacología , Clortalidona/uso terapéutico , Propanolaminas/farmacología , Propranolol/farmacología , Administración Oral , Adulto , Atenolol/administración & dosificación , Presión Sanguínea/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Estudios de Evaluación como Asunto , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Hipertensión/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Propranolol/administración & dosificación , Renina/sangreRESUMEN
The absorption of oxalate was investigated in a healthy subject after ingestion of oxalate-rich meals (spinach and rhubarb) with and without addition of 14C-labeled oxalic acid and calcium oxalate, and after oxalate-free meals with addition of nonlabeled sodium oxalate and calcium oxalate. Under these conditions, calcium oxalate was absorbed to the same extent as soluble oxalate; only a small percentage (2.4 +/- 0.7) of the total oxalate load was absorbed. Significant oxalate absorption occurred within 1 to 8 h after ingestion. The results suggest that under normal conditions the proximal part of the small bowel is a major absorption site.
Asunto(s)
Dieta , Absorción Intestinal , Oxalatos/metabolismo , Adulto , Oxalato de Calcio/metabolismo , Radioisótopos de Carbono , Humanos , Cinética , Masculino , Oxalatos/administración & dosificación , Oxalatos/orina , Ácido Oxálico , VerdurasRESUMEN
Hypercalcemia, due to autonomous functioning of the parathyroids following long standing secondary hyperparathyroidism, is a well known complication in patients with renal osteodystrophy, which can on most cases be treated by parathyroidectomy only. While patients with renal osteodystrophy react favorably to supplementation of active vitamin D metabolites to prevent or reverse renal osteodystrophy, the use of these drugs is bound to result in greater hypercalcemia in those patients who are already hypercalcemic. The question rose if the bisphosphonate amino hydroxypropylidene bisphosphonate (APD) would decrease plasma calcium concentration sufficiently in order to create room for the use of vitamin D to cure the osteomalacia component of the osteodystrophy and simultaneously block the excessive bone resorption. Therefore, five patients with renal osteodystrophy and hypercalcemia were treated for up to 9 months with APD. Three of them, who were on chronic hemodialysis, received 15 mg APD i.v. 3 times a week, the 2 other patients with severe renal failure received 200 mg APD orally. Ionized calcium in plasma did not decrease. Histological investigation of bone samples, obtained before and after therapy, showed an increase of fibrous tissue and a remarkable increase in the number of osteoclasts or osteoclast-like cells not only along the bone-margin, but mainly within the bone-marrow. We conclude that in patients with renal failure with hypercalcemia, APD in the doses used had no effect on plasma calcium level, but caused a striking change in bone histology. Although the consequences of these findings are not yet clear, they do not seem to indicate improvement of bone structure.
Asunto(s)
Trastorno Mineral y Óseo Asociado a la Enfermedad Renal Crónica/complicaciones , Difosfonatos/uso terapéutico , Hipercalcemia/tratamiento farmacológico , Adulto , Femenino , Humanos , Hipercalcemia/etiología , Masculino , Persona de Mediana Edad , PamidronatoRESUMEN
A patient is presented who after 2 years of hemodialysis showed all of the features of congestive cardiomyopathy to a very severe degree: dilation of all cardiac compartments, increased left ventricular mass, low ejection fraction, diastolic disturbances, third- to fourth-degree mitral and tricuspid regurgitation, ascites, and low blood pressure. All of these abnormalities gradually but completely disappeared during 5 months of persistent ultrafiltration during or between dialysis sessions. It was concluded that chronic fluid overload was a major factor in the cardiac disease of this patient. Unrecognized hidden fluid overload has long been known (but also neglected), and its prevention deserves top priority in chronic dialysis patients.
Asunto(s)
Cardiomiopatía Dilatada/etiología , Cardiomiopatía Dilatada/terapia , Diálisis Renal/efectos adversos , Ultrafiltración , Uremia/terapia , Desequilibrio Hidroelectrolítico/complicaciones , Desequilibrio Hidroelectrolítico/terapia , Adolescente , Cardiomiopatía Dilatada/patología , Cardiomiopatía Dilatada/fisiopatología , Femenino , Humanos , Índice de Severidad de la Enfermedad , Factores de Tiempo , Uremia/complicaciones , Desequilibrio Hidroelectrolítico/etiologíaRESUMEN
Findings in 76 subjects without cardiac failure were analyzed to detect relationships between observed changes in transthoracic electrical impedance (TEI) and total body extracellular fluid volume (ECFV) during various manoeuvres and between absolute TEI and ECFV values. TEI was normalized to electrode distance (Z0/delta el) and ECFV to lean body mass (ECFV/LBM). A distinct relation was found between percent changes of TEI and ECFV (r = -0.76, p less than 0.0001) and between absolute Z0/delta el and ECFV/LBM values (r = -0.66, p less than 0.0001 for men; r = -0.61, p less than 0.0001 for women). It is concluded that in the same subject a change in TEI is possibly a sensitive index for a change in ECFV and that a single measurement of TEI, normalized to electrode distance, gives information about the state of hydration (ECFV) of patients without cardiac failure.
Asunto(s)
Cardiografía de Impedancia , Espacio Extracelular , Pletismografía de Impedancia , Equilibrio Hidroelectrolítico , Adulto , Diuresis , Femenino , Humanos , Infusiones Parenterales , Masculino , UltrafiltraciónRESUMEN
Evidence is accumulating that insulin is a hypertensive factor in humans. The involved mechanism may be its sodium-retaining effect. We examined whether insulin causes sodium retention through a direct action on the kidney, as is generally assumed, or indirectly through hypokalemia. Insulin was infused (euglycemic clamp technique) with and without potassium infusion to prevent hypokalemia in six healthy subjects. Without potassium infusion, insulin caused a marked decrease in plasma potassium (-0.75 mmol/L), and decreased urinary sodium and potassium excretions by, approximately 38% and 65%, respectively. Simultaneous potassium infusion largely prevented the decrease in plasma potassium, as well as the decrease in urinary sodium and potassium excretions. These data suggest that the acute antinatriuretic effect of insulin may be largely mediated in an indirect way, ie, through hypokalemia.
Asunto(s)
Insulina/farmacología , Potasio/sangre , Sodio/metabolismo , Adulto , Combinación de Medicamentos , Humanos , Infusiones Intravenosas , Insulina/sangre , Riñón/metabolismo , Masculino , Natriuresis/efectos de los fármacos , Concentración Osmolar , Potasio/farmacología , Potasio/orina , Valores de ReferenciaRESUMEN
Lithium clearance (CLi) has been advanced as a measure of sodium delivery from the proximal tubules. Because information on the intrarenal effects of water immersion is only limited, and available data are conflicting with respect to the effects on the proximal tubule, we examined the effects of 3 h of water immersion on renal functional parameters, including CLi, in eight healthy subjects. Studies were carried out during maximal water diuresis. Water immersion resulted in a significant increase in sodium excretion, from preimmersion values of 74.0 +/- 9.6 to 155.4 +/- 12.0 mumol/min at the third immersion hour (P less than 0.01). This natriuresis was accompanied by an increase in CLi from 26.3 +/- 1.9 (preimmersion) to 37.0 +/- 3.1 ml/min (P less than 0.01). Fractional lithium reabsorption (FRLi) decreased from 76.4 +/- 1.0 to 69.6 +/- 1.3% (P less than 0.01). None of these changes was found in eight healthy subjects undergoing a time-control study without water immersion. The large fall in FRLi found during immersion is compatible with a major resetting of the proximal glomerulotubular balance. In this regard the renal response to water immersion resembles saline expansion rather than mere intravascular expansion. The lithium data suggested a large rise in distal delivery accompanied by an almost as large rise in distal reabsorption. The free water clearance data were in agreement with this interpretation. However, no changes were found in fractional excretion of phosphate and uric acid. Therefore such a major resetting of proximal glomerulotubular balance can be doubted.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Inmersión , Túbulos Renales/metabolismo , Litio/farmacocinética , Natriuresis , Adulto , Femenino , Humanos , MasculinoRESUMEN
Angiotensin has an intrarenal action which may not parallel its action in the general circulation. We investigated whether the urinary excretion rates of angiotensin I and II (UV-AI, UV-AII) can be used as a marker of renal production. We therefore measured UV-AI, UV-AII, plasma angiotensin I and II (PAI, PAII), and plasma renin activity (PRA) in healthy subjects under conditions influencing the renin-angiotensin system: captopril injection (n = 7), enalapril treatment (n = 9), furosemide infusion on high and low sodium intake (n = 6), indomethacin treatment (n = 8), and head-out water immersion (three sodium intakes). After captopril (acute) and enalapril (chronic), PAI and PRA increased, PAII decreased, but neither UV-AI nor UV-AII changed. During furosemide infusion, PAI, PAII, PRA, as well as UV-AI and UV-AII increased. During indomethacin treatment, PAI, PAII, and PRA decreased, whereas UV-AI and UV-AII did not change consistently. Sodium restriction increased PAI, PAII, and PRA, but did not alter UV-AI and UV-AII. Head-out immersion decreased PAI, PAII, and PRA, but did not change UV-AI and UV-AII. The relative constancy of the urinary AI and AII excretion rates makes it doubtful whether urinary angiotensins reflect changes of renal angiotensin production.
Asunto(s)
Angiotensina II/orina , Angiotensina I/orina , Sistema Renina-Angiotensina/fisiología , Adulto , Angiotensina I/sangre , Angiotensina II/sangre , Captopril/farmacología , Enalapril/farmacología , Femenino , Furosemida/farmacología , Humanos , Inmersión/fisiopatología , Indometacina/farmacología , Masculino , Renina/sangre , Sistema Renina-Angiotensina/efectos de los fármacos , Sodio en la Dieta/administración & dosificaciónRESUMEN
Physicians have a professional obligation to be among the first to defend human rights. Accordingly they have established organisations in many countries to that aim, which are united in the International Federation of Health and Human Rights Organisations (IFHHRO). The author was invited by this federation to attend several trials against members of the Turkish sister organisation. In one of them the doctor's duty to protect his patients' privacy was at stake. This physician has since been acquitted because of insufficient evidence. In Turkish society there are opposed conservative and liberal democratic forces: on the one hand people try to maintain the democratic and constitutional state, on the other some circles hold the opinion that undemocratic and inhuman measures are necessary to counter the dangers of terrorist movements. Even in the Netherlands the right of physicians not to reveal confidential information regarding 'illegal immigrants' has recently been challenged, and until now the medical organisations have not protested.
Asunto(s)
Derechos Humanos/legislación & jurisprudencia , Cooperación Internacional , Rol del Médico , Prisioneros/legislación & jurisprudencia , Tortura/legislación & jurisprudencia , Agencias Voluntarias de Salud/organización & administración , Derechos Civiles/legislación & jurisprudencia , Confidencialidad/legislación & jurisprudencia , Humanos , Países Bajos , Turquía , Estados UnidosRESUMEN
The stormy development of Turkey in this century resulted in a drastic decrease of illiteracy and in a craving for knowledge among the younger generations. Qualitatively good students are admitted to universities. In the last 25 years, 47 new universities were founded (8 of them private ones), partly for political reasons. Teachers of medicine are underpaid, so that many earn extra money by working in a private practice. The results of medical teaching are adequate, owing in part to quality and motivation of students and interns. Much research is being subsidized by the Turkish Institute for Scientific and Technical Research, Tübitak, but bureaucracy inhibits originality. Research and postgraduate training are increasingly controlled by the pharmaceutical industry. Primary medical care is underdeveloped. The quality of medical treatment is technically adequate; modern diagnostic and surgical methods are available in all major centres. There is much private enterprise in health care (private clinics, private laboratories, research centres, universities and pharmacies). The latest drugs are available and given preference in prescribing. In Southeast Turkey, populated by Kurds, however, the economy has come to a complete standstill and there is an enormous shortage of physicians and hospitals. The prevalence of renal diseases differs from that in the Netherlands: fewer cystic kidneys, less diabetic nephropathy and nephropathy due to analgetics, but more acute glomerulonephritis and amyloidosis due to familial Mediterranean fever. Haemodialysis, is one of the fastest-growing methods of treatment; peritoneal dialysis is rapidly gaining ground. Kidney transplantations have been performed regularly since 1975.
Asunto(s)
Atención a la Salud/normas , Educación Médica/normas , Nefrología/normas , Humanos , Enfermedades Renales/terapia , TurquíaRESUMEN
The author, a professor of nephrology, reports some impressions of his 7-year stay in Turkey. He worked at the Ege University in Izmir, traditionally one of the most 'western' cities. He and his wife, who gave unpaid assistance to dialysis patients, attempted to integrate into Turkish society as fully as possible. They traversed the country in weekends and holidays and introduced as many Dutch guests as they could to the unique archeological treasures, the magnificent nature and the extremely friendly population. Work at the university focused increasingly on cultivating a critical attitude with regard to the self, society and the trends and commercialization of medicine in Turkey and in the rest of the world. Self-reliance, also, had to be strengthened. Although this contravened the authority-based Turkish educational system, the efforts were clearly appreciated and even stirred enthusiasm in many of the younger people. There is no doubt that a foreign worker is regarded much more favourable in Turkey than in the Netherlands.