Plasma met-enkephalin and leu-enkephalin has been measured in a group of 28 patients with chronic renal failure, to discover whether these opioids are affected by standard haemodialysis and ...haemofiltration. Met-enkephalin was markedly higher (P less than 0.001) in uraemic patients than in a group of 13 normal subjects, and was directly related to plasma creatinine (r = 0.60; P less than 0.01) and to plasma urea (r = 0.36; P = 0.06). In contrast, leu-enkephalin was suppressed in uraemic patients (P less than 0.001). Met-enkephalin fell slightly but significantly (P less than 0.02) after both haemodialysis and haemofiltration; however, on average it remained at concentrations four times higher than normal. No changes in plasma leu-enkephalin were observed after haemodialysis and haemofiltration. The cause(s) of the altered plasma concentrations of these opioid substances remains to be clarified.
To investigate the relationship between carotid atherosclerosis and some major cardiovascular risk factors in uremic patients on chronic dialysis.
A cross-sectional study was carried out in 119 ...unselected dialysis patients (89 on hemodialysis and 30 on chronic ambulatory peritoneal dialysis, CAPD). Fasting blood sampling for serum lipids, albumin, hemoglobin, and echo-colour-Doppler evaluation of common carotid arteries were performed in all patients (during the non-dialysis day in hemodialysis patients). In hemodialysis patients BP was measured before and after dialysis; in CAPD patients home BP values were recorded during the month before the study day.
Ninety-five patients had at least one plaque and 57 had at least four plaques. Thirty-eight had mild and eleven severe carotid stenosis. In multiple regression models, the mean internal diameter of carotid arteries was explained (R=0.52, P=0.0001) by systolic pressure (r=0.39), serum cholesterol (r=-0.28), age (r=0.27) and smoking (r=0.24) while the degree of carotid stenosis was predicted (R=0.39, P=0.0001) by age (r=0.36) and smoking (r=0.25). The number of atherosclerotic plaques was explained (R=0.51, P=0.0001) by age (r=0.36), smoking (r=0.25) and pulse pressure (r=0.20), serum albumin just failing to reach statistical significance (P = 0.06). However, serum albumin was a significant and independent predictor of the number of atherosclerotic plaques (r=-0.26) in hemodialysis patients (n=89). Sex, diabetes, Kt/V, duration of dialysis treatment, hemoglobin, serum calcium and phosphate did not add any predictive power to the models.
In dialysis patients arterial pressure and smoking are associated with carotid atherosclerosis. Serum albumin appears to serve as an independent predictor of carotid atherosclerosis.
We have studied the metabolic response to changes in calcium in 15 hypercalciuric essential hypertensives, in 8 normotensive hypercalciuric stone formers and in 11 normotensive healthy subjects ...matched for age and sex. At variance with hypercalciuric stone formers, at low calcium intake hypercalciuric hypertensives did not appropriately reduce urinary calcium excretion and developed mild hypocalcemia. Furthermore, the PTH response to calcium deprivation was not appropriately enhanced in these patients. The data indicate that different mechanisms prevail in these two forms of hypercalciuria: the renal in essential hypertension and the intestinal in urolithiasis.
A total of 60 pediatricians from the districts of Genova and Savona, randomly selected, responded to a survey designed to determine several aspects of their attitude toward the prevention of dental ...caries and particularly the use of fluoride supplement (table II). The survey demonstrated (table III) that 80% of the physicians prescribe fluoride without knowing the fluoride content in the water supply of their region. Therefore, the dosage schedule used by 56% of the physicians is higher than the optimal, 27.5% is lower and only 16.5% use the optimal dosage as recommended by the American Academy of Pediatric, Committee on Nutrition.
The role of endogenous opioids in the baroreflex dysfunction of dialysis patients Zoccali, C; Ciccarelli, M; Mallamaci, F ...
Proceedings of the European Dialysis and Transplant Association - European Renal Association. European Dialysis and Transplant Association - European Renal Association. Congress,
1985, Letnik:
21
Journal Article
We studied the effect of the opiate antagonist naloxone on the response to Valsalva manoeuvre in nine dialysis patients, in six diabetics with normal renal function whose response to Valsalva ...manoeuvre was similar to that of dialysis patients and in eight healthy subjects. Naloxone caused a progressive increase in the subnormal Valsalva ratio in dialysis patients but it did not cause any change in diabetics nor in healthy subjects. The increase in Valsalva ratio observed in dialysis patients was due to restoration of the parasympathetically mediated reflex bradycardia of the release phase of the manoeuvre. Endogenous opioids may be responsible for the baroreflex dysfunction of dialysis patients.
Vasoconstriction-volume analysis postulates that arteriolar vasoconstriction is the mechanism of blood pressure elevation in patients with "high-renin" essential hypertension while a volume expanded ...state with relatively dilated arterioles sustains "low renin" essential hypertension. To test this hypothesis we carried out hemodynamic and PRA studies in 43 essential hypertensives. Cardiac index was directly related to PRA (r=0,41; p less than 0,01), by contrast, peripheral vascular resistances and plasma volume were unrelated to PRA. The data do not support the bipolar hypothesis since vasoconstriction and volume expansion are associated with unpredictable changes in PRA. The direct relationship between CI and PRA may be interpreted as the result of a common factor (presumably sympathetic nervous system) governing both functions.
To investigate the mechanisms that sustains arterial hypertension in chronic uremia we performed hemodynamic studies in 13 dialysed uremics by means selective radiocardiography (Donato-Giuntini ...method). The 5 dialysed patients with dialysis controllable hypertension (GROUP B) had higher cardiac indexes (CI) respect to the 8 dialysed normotensive controls (GROUP A) (CI: Group B 4,250 l/min/m2, Group A 3,610 l/min/m2; p less than 0,05). The higher CI in group B appeared independent from the degree of anemia because the two groups had comparable hematocrit values (Hct:Group B 26,2% Group A 26,4%); On the other hand the slight blood volume expansion we observed in group B (7%) respect to group A hardly explains the observed difference in CI. It is interesting that pulmonary blood volume/total blood volume ratio (PBV/TBV) was significantly higher in dialysed hypertensives (PBV/TBV: Group B 14,26%, Group A 11,15%; p less than 0,05) The higher PBV/TBV can be the result of a decrease in venous compliance and could explain the higher CI in group B; further studies however are warranted to elucidate this point.
