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P Zech

Publications and source records attributed to P Zech.

At least 37 records · Page 2Linked to original sources
PubMed1993

Is erythropoietin treatment safe and effective in myeloma patients receiving hemodialysis?

Still few data are available on efficacy and safety of recombinant erythropoietin (rEPO) in patients with myeloma and end-stage renal failure (ESRF); two such hemodialysed patients are reported in whom only partial response was observed, despite iron, folic acid supplementation and, in one case, high doses of rEPO (320 IU/kg/week). Despite improvement in well being and no need of further transfusion, hemoglobin did not reach 80 g/l. One patient developed recurrence 4 weeks after starting rEPO. Patients with ESRF and myeloma should benefit from rEPO but particular attention should be paid to marrow proliferation.

Anemia↗
PubMed1992

Influence of the level of hydration on the renal response to a protein meal.

Recent studies have suggested that the renal effects of high protein intake could be mediated, at least in part, by vasopressin and/or an increase in the urinary concentrating activity. The present study investigated the influence of the level of hydration, and hence of the activity of the concentrating process, on the renal response to an acute oral protein load. Clearance studies were performed before (Control) and during three hours after a protein meal (1.5 g/kg body wt protein as cooked meat) in ten healthy volunteers. This study was performed twice at a two to three week interval under either constant low (LowH) or high (HighH) hydration. In spite of the marked difference in initial diuresis (3.1 +/- 0.3 in LowH vs. 13.9 +/- 0.7 ml/min in HighH) and urine osmolality (501 +/- 42 in LowH vs. 99 +/- 3 mOsm/kg H2O in HighH), a similar relative decrease in urine flow rate was observed following the meal in both conditions. TcH2O increased progressively by 70% in LowH whereas CH2O decreased by 40% in HighH. Plasma vasopressin showed a progressive increase with time in LowH (from 1.10 +/- 0.26 in control, to 1.98 +/- 0.35 pg/ml at the third hour after the PM, P < 0.05) but not in HighH (0.53 +/- 0.09 to 0.70 +/- 0.17 pg/ml). Glomerular filtration rate (inulin clearance) increased significantly on the second post-prandial hour under LowH but not under HighH. Excretions rates of Na, Cl, K, and urea increased after the meal, however, not to the same extent nor with the same time course in the two conditions. Significant positive correlations were observed between GFR and TcH2O, urine osmolality, or the ratio of urine-to-plasma urea concentrations in LowH. These results suggest that the protein-induced hyperfiltration is partially blunted by a high water intake, and hence is dependent, directly or indirectly, on the urine concentrating activity.

Adult↗
PubMed1992

Renal venous erythropoietin concentrations in hypertensive patients with unilateral renal disease.

In 24 hypertensive patients with unilateral renal disease, the erythropoietin (Epo) concentration ratio in the renal veins was compared with the renin ratio. Seven patients showed moderately elevated peripheral Epo values. Epo and plasma renin activity were significantly positively correlated both in peripheral and renal veins. This suggests that the reduction of renal blood flow was a common, but not unique, stimulating factor of Epo and renin secretion. Epo ratio appeared insensitive since it was greater than 1.5 in only 30% of patients with a renin ratio > 2. Our results indicate that the Epo concentration ratio in renal veins cannot be proposed as a substitute for the currently used renin ratio.

Adolescent↗
PubMed1992

Increase of circulating insulin-like growth factor-I in chronic renal failure is reduced by low-protein diet.

We performed a nutritional trial to assess the variations of circulating insulin-like growth factor-I (IGF-I) in chronic renal failure (CRF). Eight patients suffering from mild renal failure (SCr = 374 +/- 52 mumol/l) were prescribed a standard diet for 1 month followed by 1 month of protein restriction. Mean protein intake was 0.77 and 0.46 g/kg BW/day, mean caloric intake 25 and 24.7 kcal/kg BW/day for the first and the second month, respectively. After each period of diet, nitrogen balances were negative (-1.2 +/- 1.6 and -1.6 +/- 0.9 g/N/day). Despite these low-caloric conditions, mean serum IGF-I level was at the upper level of normal (358 +/- 136 ng/ml) after 1 month of standard protein intake, and statistically reduced (289 +/- 122 ng/ml, p < 0.002) by the low-protein diet. No correlation was observed between serum IGF-I levels and protein, caloric intake, and nitrogen balances for the two periods. Estimation of the IGF-I binding by the ratio of extracted to nonextracted IGF-I value suggested abnormal binding in CRF. This binding was modified by reduced protein intake. In conclusion, larger studies are needed in CRF to assess the significance of IGF-I variations and the IGF-I binding proteins which modulate the bioactivity of this growth factor.

Adult↗
PubMed1991

[Microscopic hematuria in adults. Prevalence and associated factors].

The finding of microscopic haematuria in the course of systematic screening accounts for 10 percent of consultations in nephrology clinics. We carried out an investigation in a population of 8,194 workers of the metallurgical and chemical industries, 89.6 percent of whom were male and 69.8 percent were under 49 years of age; 51.2 percent were smokers or ex-smokers, 9.9 percent had arterial hypertension and 2.1 percent had diabetes mellitus. Microscopic haematuria was detected by the dipstick method in 3.53 percent of the subjects tested. Phase contrast microscopy, performed in 222 subjects, showed that the origin of the haematuria was glomerular in 90.5 percent, extraglomerular in 2.5 percent and undetermined in 0.9 percent of the cases. Urinary sediment was normal in 6.3 percent. The prevalence of microscopic haematuria was significantly higher in women, in subjects under 49 years of age, in hypertensive subjects, in smokers or ex-smokers, in subjects who has received non-steroidal anti-inflammatory drugs during the past 6 months and in chemical industry workers.

Adolescent↗
PubMed1991

Stress-induced renal functional alterations in normotensives.

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.

Adult↗
PubMed1991

Comparison of hemostasis with two high-flux hemocompatible dialysis membranes.

Eight adults with chronic renal failure were dialyzed using polyacrylonitrile (AN 69) or polysulfone (PS) membranes with a high (HHR) or low (LHR) continuous non-fractionated heparin regimen--a total of either 90 or 50 IU/kg body weight. With the HHR, for a mean anti-Xa (aXa) activity of around 0.40 IU/ml, no plasma activation of coagulation was observed; fibrinopeptide A (FPA) was in agreement with the residual blood volume (RBV) and the state of the bubble trap, especially with the PS membrane. With the LHR, for a mean aXa below 0.21 IU/ml, there was only moderate activation of coagulation. The PS membrane gave different results from the AN 69 membrane, RBV values on the HHR and aXa being lower on both the HHR and LHR, with FPA values being regularly lower on the LHR. The decrease in plasma beta-TG on the LHR was more marked with the PS than with the AN 69 membrane due to loss on dialysis or adsorption, as shown by the arterio-venous difference. The increase in plasma PF4 was related to the effect of heparin. However, there was no platelet activation. On the LHR, platelet count and intraplatelet beta-TG and PF4 levels remained very stable. The two high-flux membranes were very hemocompatible and require only low doses of heparin, but the dialyzer with AN 69 membrane need its geometry improving.

Acrylic Resins↗
PubMed1991

[Diseases associated with renal amyloidosis. Apropos of 216 cases].

Diseases associated with renal amyloidosis were evaluated in 216 patients observed between 1956 and 1989. The percentage of secondary amyloidosis decreased from 72 to 47%, where it has remained for the past 20 years, despite the clear diminution in the tuberculosis rate; this is due to its increased incidence of association with rheumatoid diseases. Dysglobulinemia was found in more than 75% of the patients with AL amyloidosis. Amyloidosis associated with this dysglobulinemia, of which 30% were myelomatous, represented more than 25% of the cases observed during the past decade and constituted, with rheumatoid arthritis, the two most common etiologies.

Adolescent↗
PubMed1991

[Renal function during stress in hypertensive patients].

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.

Adult↗
PubMed1990

Basal prostaglandin synthesis by the isolated perfused rat kidney.

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.

Animals↗
PubMed1990

Cardiovascular reactivity to and renal impact of stress and exercise: effects of bisoprolol.

The orthosympathetic nervous system is involved in the pathogenesis of essential hypertension. In this study, we carried out tests of sympathetic stimulation using successfully an isometric exercise and a psychological stress. The efficacy of the two tests in 10 normotensive patients (NTs) was assessed by a significant increase in blood pressure and heart rate and a significant increase in metanephrine urinary excretion. These tests, repeated 2 months later, were perfectly reproducible in NTs. The cardiovascular response during exercise and stress was significantly higher in 10 hypertensive patients (HTs) than in NTs. At rest, urinary norepinephrine excretion was significantly higher in HTs. In contrast to NTs, stress in HTs significantly increased urinary excretion of epinephrine and norepinephrine, whereas exercise failed to increase urinary catecholamine excretion in both groups. In HTs, both tests induced an increase in microalbuminuria. Among functional renal parameters, only proximal sodium reabsorption (measured by lithium clearance) was significantly lower in HTs than in NTs, compensated by a higher distal reabsorption. In HTs, 2 months of treatment with bisoprolol reduced rest and peak heart rate and blood pressure, but failed to reduce blood pressure reactivity to the orthosympathetic stimulation. Proximal sodium reabsorption at rest was normalized by the treatment. Bisoprolol was also able to reduce microalbuminuria during the 24 h and in the rest period preceding the test, but the same percent increase was observed during tests.

Adrenergic beta-Antagonists↗
PubMed1990

[Is it possible to use creatinine for following the development of renal insufficiency?].

Accurate methods of measuring glomerular filtration rate are usually considered as expansive and time consuming. Therefore, alternative methods (creatinine clearance, either calculated or measured, reciprocal plasma creatinine, slopes of creatinine vs time) have frequently been used to assess the rate of progression of renal failure and predict the time of dialysis. The present review underlines the limitations of such techniques frequently underestimated in recent trials intending to evaluate the potential benefit of protein restriction. It delimitates the restrictive conditions in which such methods could be used for clinical but not research purposes.

Creatinine↗