Morbidity and mortality in hemodialysis patients with and without erythropoietin treatment: a controlled study.
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Biomedical subjects
Publications and source records attributed to M Hilfenhaus.
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A hepatitis non-A,non-B-associated substance (HNANB-AS) excreted in feces has been detected by means of a sandwich radioimmunoassay using reconvalescent serum and IgG from patients with posttransfusion HNANB. 4380 stool filtrates from 1599 patients were screened with this assay. In patients with posttransfusion or sporadic acute and chronic HNANB the substance was detected with a mean frequency of 34%, in acute posttransfusion HNANB, where samples were screened at the beginning of the clinical symptoms, 71.4% of stool specimens were positive for HNANB-AS. A high frequency of positive results was found in patients undergoing dialysis (31.3%), hemophiliacs (16.6%) and patients with cryptogenic cirrhosis (16%). Positive specimens were seen in hepatitis A (7.1%), acute and chronic HBV-infection (9.6%), various liver diseases (7.8%), outpatients of a physician (3.1%) and clinical or laboratory staff (6%). In these groups, too, anamnestic data speaking in favour for a possible HNANB frequently were obtained. The discovery of a partially double-stranded circular DNA of 5.0 Kb in HNANB-AS which sequence differs from human, bacterial and known viral DNA, argues the presence of a viral particle in stools of patients with sporadic and parenteral HNANB.
In RDT hemosiderosis appears to be an inevitable complication only in the small number of patients in need of frequent transfusions. To prevent clinical consequences (e.g. cardiomyopathy) known from polytransfused patients without renal disease, transplantation should be considered in RDT patients in need of frequent transfusions. Iron substitution - preferably oral - to replace dialysis-related iron loss does not cause clinically significant hemosiderosis provided iron stores are monitored adequately. A sufficient method of controlling iron stores in RDT patients under iron substitution or regular transfusion therapy is a twice annual determination of serum ferritin concentration. The treatment of choice for hemosiderosis in nontransfused RDT patients is discontinuation of iron substitution. When polytransfused RDT patients with severe hemosiderosis cannot be transplanted and submitted consecutively to phlebotomy, DFO treatment is indicated. Quantitative data regarding optimal dosage and application of DFO in RDT patients are not yet available. Constant infusion of DFO during hemodialysis may be superior to bolus application.
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In the rat, a circadian rhythm can be demonstrated in plasma levels and in urinary excretion rates of aldosterone and of corticosterone, reflecting rhythmic variations in adrenocortical secretion. There is also a circadian rhythm in the urinary excretion rates of sodium and of potassium in rats with unrestricted food consumption. The rhythmic pattern of potassium excretion seems to be controlled by the rhythm of corticosterone and/or aldosterone, whereas the rhythmic pattern of sodium excretion seems to be independent of adrenocortical secretion.
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In 46 patients of the chronic hemodialysis program blood pressure regulation was studied according to variations of sodium and fluid balance. A strong relationship was observed between blood pressure and the amount of exchangeable sodium. In the hypertensive patients exchangeable sodium was increased depite fulfilled clinical signs of sufficient dehydration. The blood volume was found to be small and the plasma renin activity increased in those hypertensive patients, in which sufficient fluid depletion was inhibited by extreme fluctuations of the blood pressure during dialysis. A diminution of the sodium concentration keeping the fluid balance constant induced an increase of blood pressure and deteriorated the subjective feeling of the patients. By an increase of the sodium concentration up to 155 mEq/l severe blood pressure fluctuations during during dialysis could be prevented, although further fluid was taken off by ultrafiltration. This effect seemed to be mediated--at least partly--by an increase of the low blood volume and a suppression of plasma renin activity. After the patients became normotensive, dialysis procedure could be continued with normal sodium concentration. By a temporary high sodium regimen of the dialysis procedure some patients with renal failure and 'uncontrollable hypertension' can be preserved from bilateral nephrectomy.
In rats kept under standard conditions urinary aldosterone exretion rate (UAER) and plasma aldosterone concentration (PAC) showed a circadian rhythm with peak values at the beginning of the dark perioith a single dose of DOC (2 mg/kg sc) or given saline as drinking water UAER and PAC decreased to very low levels. Restriction of dietary sodium for 5 weeks increased UAER and PAC 60-fold and 100-fold, respectively. Treatment with ACTH (250 or 500 microng/kg iv) stimulated UAER 8 h following injection and PAC 1 h after injection. In rats treated with a single dose of furosemide (25 mg/kg sc) PAC increased to maximal values within 90 min and reached control values within 24 h. Twenty-four hours-UAER also increased after furosemide treatment. UAER paralleled PAC under all experimental conditions tested. Therefore, our results suggest that UAER is a reliable index of the activity of the renin-angiotensin-aldosterone system in rats under conditions of low and high aldosterone secretion. Measurement of UAER is a useful tool for studies on aldosterone levels in rats over a long period of time.
The 24 h-course of plasma renin activity (PRA), plasma aldosterone concentration (PAC), plasma corticosterone concentration (PCC) and of the urinary excretion of sodium, potassium and aldosterone was investigated in male Sprague-Dawley rats under different experimental conditions. The data obtained can be summarized as follows: 1. The renin-angiotensin-aldosterone system (RAAS) of the rat is subject to a circadian rhythm which is largely in phase with the well-known rhythm of the pituitary-adrenal axis. This rhythm can be demonstrated in PRA as well as in plasma concentrations and urinary excretion rates of aldosterone. The rhythm of urinary excretion of electrolytes is unlikely to be due to the rhythm of aldosterone secretion. 2. The light-dark cycle is the main synchronizer for these rhythms: inverting the light-dark cycle for 5 weeks entirely inverts the rhythms of all the parameters cited. 3. A dissociation of the rhythms of PRA and PAC can be observed following sodium restriction or dexamethasone treatment. A role of ACTH IN regulating the rhythmic pattern of aldosterone secretion is suggested by the finding that PAC and PCC follow the same pattern of circadian variations under every experimental condition tested. 4. The responsiveness of the RAAS to stimulation or suppression varies with the time of day. 5. It is suggested that experiments ought to be performed not only during the inactive (light hours) but also during the active (dark hours) phase when investigating the RAAS in the rat. This can conveniently be achieved by the use of an animal room with a reversed lighting regime.
1. The circadian patterns of clinically relevant parameters were studied in 109 young, healthy soldiers. 2. Erythrocytes, hematocrit, creatinine and cortisol exhibited very stable rhythmic patterns which were found by continuous examinations of the same persons as well as in examinations of different persons at different times. 3. The rhythmic patterns of leukocytes, blood glucose and body temperature were strongly influenced by stress caused by the first confrontation with an unknown hospital-like situation or by pain caused by blood sampling.
Canrenone was administered in doses of 2 x 82 mg and 2 x 164 mg per day over a period of 10 days to diabetic patients without cardiovascular, liver or kidney involvement. Aldosterone excretion and plasma aldosterone increased only slightly during both regimes. There was a clear-cut increase in aldosterone excretion only after discontinuation of canrenone. Excretion of sodium, potassium and fluid was not significantly changed either during or after treatment. The lack of effect of canrenone on the kidney was in contrast to the significant decrease in serum sodium and increase in serum potassium, and the significant, dose-dependent rise in plasma renin activity following canrenone administration. The increased plasma renin activity persisted for some days after discontinuation of canrenone. It is suggested that canrenone primarily exerted its effect in the distal part of the large intestine where ionic movements are most affected by aldosterone. The disproportionately slight increase in plasma aldosterone concentration and aldosterone excretion, in spite of the greatly elevated plasma renin activity and serum potassium level, is considered to be due to a direct inhibitory effect of canrenone on aldosterone production in the adrenals.
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In 21 patients undergoing ear operations associated with minimal bleeding plasma renin activity and plasma aldosterone concentration were studied before and during surgical procedure, and in the postoperative state. Studies were performed in two groups, one without (n=9) and one with beta-adrenergic blockade by Practolol (n=12). Plasma renin activity increased significantly during halothane anaesthesia alone whereas the surgical manipulations did not further influence mean values significantly. Thus, it seems to be established that anaesthesia per se influences renin secretion. On the other hand Practolol does not show an inhibiting effect. The plasma renin increase following anaesthesia is due to the hemodynamic including renal hemodynamic, changes as well as to activation of the sympatho-adrenal system. Changes in plasma aldosterone are variable. For the greater part of patients with beta-adrenergic blockade an increase during the operative procedure was found. However, in some patients especially in the control group, plasma aldosterone was unchanged or decreased in spite of increasing renin values. Significantly lower plasma potassium concentration in these cases seems to indicate the important contributing role of potassium for the short-term regulation of aldosterone secretion. Plasma sodium concentration remained unchanged for the periods studied.
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