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Biomedical subjects

E Ritz

Publications and source records attributed to E Ritz.

At least 919 records · Page 51Linked to original sources
PubMed1978

Long-term administration of vitamin D steroles in incipient and advanced renal failure: effect on bone histology.

In 36 patients with incipient and advanced renal failure (CCr 80--30 ml/min X 1.73 m2), serum chemistry including ionized Ca, serum PTH and fractional intestinal absorption of Ca (whole body counter; two-dose-technique; 47Ca p.o. and i.v. to correct for urinary and endogenous fecal loss were measured. Quantitative bone histology after in vivo tetracycline double labeling was evaluated from undecalcified sections before and 18 months after therapy with vitamin D3 or 5,6-trans-25-OH-CC in a dose sufficient to raise intestinal absorption and/or urinary excretion of Ca. Intestinal absorption of Ca was impaired in some patients at a GFR of 60 ml/min/1.73 m2. After up to 10000 U/d 5,6-trans-25-OH-CC and 8000 IU/d vitamin D3, respectively, fractional intestinal absorption of Ca rose and was normalized in all patients. There was a concomitant rise in urinary Ca. Serum PTH fell, but did not always return into the normal range. Ionized Ca rose in all patients. Bone histology was evaluated in 17 of these 36 patients after informed consent was obtained. The mass of mineralized bone (Vv) rose in 7/17 patients, pointing to a positive calcium balance. Volumetric density of osteoid (Vvos) and surface density of osteoid (Svos) fell in 10/17 patients concomitant with an increase in the fraction of mineralizing seams and a decrease in the number of lamellae in osteoid seams. Osteoclastic resorption (OCl) fell as did the fraction of woven osteoid seams. However, woven osteoid failed to disappear completely and osteoclastic resorption stayed elevated in some patients. 5,6-trans-25-OH-CC and vitamin D3, in doses that normalized intestinal absorption of Ca, failed to restore completely bone histology to normal although mineralization and collagen texture of osteoid were consistently improved. The dose response characteristics to vitamin D of different abnormalities of Ca metabolism appear to be non-uniform.

Adolescent↗
PubMed1978

Chronic hemofiltration. A critical evaluation of a new method for the treatment of blood.

The experiences which have been compiled in more than 2400 hemofiltrations confirm that this method represents an alternative way of treating uremic patients. The main advantages of chronic hemofiltration are the comfort of the patient and the ease in handling excess overhydration without extending treatment time, which is less than 3 X 3 hours/week if adequate hemofilters are used. With regard to the improvement of such typical uremic complications as severe hypertension, hypertriglyceridemia or neuropathy, hemofiltration does not seem to be superior to hemodialysis. However, since most hemofiltration patients do not require phosphate binders and, additionally, remarkable amounts of parathyroid hormone are removed during one hemofiltration, it appears possible that hemofiltration might be an important therapeutic alternative for those renal patients who suffer from severe hyperphosphatemia and secondary hyperparathyroidism.

Adult↗
PubMed1977

[Diagnosis of anticonvulsant osteomalacia in adults (author's transl)].

In 100 epileptic patients under treatment with long-term anti-convulsants, radiographs of the hands and feet, and estimations of serum 25-hydroxycholecalciferol, parathormone, alkaline phosphatase, calcium, and inorganic phosphate were done to detect a medication-induced osteomalacia. The correlation between the individual parameters was investigated. It was shown that the serum 25-hydroxycholecalciferol level and the skeletal radiograph were the most valuable in the early detection of osteomalacia. One of these investigations in addition to routine serum chemistry is recommended for the future at the yearly follow-up examinations of adult epileptics so that early and adequate treatment with vitamin D can be started.

Adolescent↗
PubMed1977

Fetal development in experimental uremia.

Uremic women on hemodialysis with metabolic bone disease (hyperparathyroidism, osteomalacia resulting from defective vitamin D metabolism) and anemia (erythropoietin deficiency) are known to give birth to infants without bone disease or anemia. Therefore, skeletal development (enchondral and desmal bone formation) and hepatic erythropoiesis were evaluated in fetuses of uremic rats. These fetuses failed to show defective mineralisation or evidence of bone disease. Bolus injection of high doses of exogenous PTH into the maternal or fetal organism did not affect fetal bone histology. In addition, no apparent defect of bone mineralisation or bone formation was found in fetuses of ricketic rats. Normal mineralisation in the offspring of uremic rats may be explained by fetal hyperphosphatemia and/or insensitivity of fetal (woven) bone mineralisation to vitamin D. Absence of fetal anemia (normal hematocrits, normal density of hematopoietic cells in the liver) in the presence of maternal anemia is presumably due to the insensitivity of fetal erythropoiesis to erythropoietin.

Animals↗
PubMed1977

[Carbenicillin induced disturbance of platelet function: a study in patients with normal renal function (author's transl)].

After therapeutic doses of carbenicillin (3X10 g/24 h) prolongation of bleeding time, measured according to Ivy, was observed (median time prior to therapy 4 min 08 s-4 min 18 s; 24 h after therapy 15-20 min; 72 h after therapy greater than 30 min) in 5 patients with normal renal function and 2 patients with slight impairment of renal function (Ccr60-70 mlX1.73 m(2)). Prolongation of bleeding time was observed at serum concentrations between 13 and 180 microgram/carbenicillin/ml. After carbenicillin was withdrawn, prolongation of bleeding time was demonstrable for 4 days, i.v. even after the drug had been eliminated completely by urinary excretion. Higher doses of carbenicillin caused more severe disturbances of platelet function. The finding of prolonged bleeding time after carbenicillin may have clinical relevance (e.g. interaction with other anticoagulants, p.o. wound bleeding, gastro-intestinal hemorrhage, thrombopenia).

Adult↗
PubMed1977

Preparation (agar zone electrophoresis) and immunological characterisation of urokinase.

Urokinase was highly purified by electrophoretical and immunological methods starting with a commercial urokinase preparation (UK-Leo). Contaminating serum proteins and enzyme activities migrated into opposite directions in agar gel electrophoresis which proved to be a valuable preparative method. The final purification achieved was 80,000 Ploug units/mg protein. Traces of albumin, alpha2HS-glycoprotein and alpha2-macroglobulin migrated towards the cathode together with UK in a multimolecular complex. Urokinase antibodies (rabbit) gave with the cathodic fraction 2 precipitation lines (Ouchterlony technique): the one precipitation line corresponded to urokinase (molecular weight on gel chromatography 32,000 daltons), the other corresponded to UK complexed with serum proteins. Urokinase antibodies completely suppressed UK activity in various commercial preparations. All these preparations showed immunological identity; on disc electrophoresis pure urokinase (32,000 daltons, 80,000 Ploug units/mg protein) still gave 2--3 bands suggesting the presence of isoenzymes.

Antigen-Antibody Reactions↗
PubMed1977

25-hydroxy-vitamin-D in nephrotic syndrome.

Serum-25-hydroxy-vitamin-D (25-OHD) nephrotic syndrome (N.S.) without renal insufficiency (urinary protein excretion greater than 3-5 g/24 h/1-73 m2; glomerular filtration-rate greater than 80 ml/min/1-73 m2). Serum-25-OHD levels were low in patients with N.S. (mean 19 nmol/1, range 4-41 nmol/1), compared with a normal range of 25-200 nmol/1. Serum-concentrations of Gc-globulin--the binding protein for vitamin D and its metabolites (D.B.P.)--were significantly (P less than 0-001) lower in patients with N.S. (mean 340 mg/1, range 190-480 mg/1) than in non-proteinuric controls (mean 440 mg/1, range 376-510 mg/1, measured by radial immunodiffusion). In contrast to non-proteinuric urine, urine of all N.S. patients contained a large amount of 25-OHD-binding capacity; D.B.P. could be detected in all N.S. urines after concentration. Scatchard analysis of the urine demonstrated the presence of a low-affinity and a high-affinity binding protein (tentatively identified as albumin and D.B.P.). These results suggest an acquired deficiency of circulating 25-OHD in N.S. secondary to urinary loss of protein-bound 25-OHD. The biological relevance of the low 25-OHD levels is unknown. There was no clinical evidence of osteomalacia (X-ray, serum-alkaline-phosphatase); however, slightly elevated serum-parathyroid-hormone (P.T.H.) levels would be compatible with borderline vitamin-D depletion.

Adolescent↗
PubMed1977

Vascular calcifications under maintenance hemodialysis.

In a cross-sectional study X-rays of the forefoot and the pelvis of 101 adult dialysis patients were taken. Vascular calcifications (forefoot) were observed in 20 patients. The incidence was higher in patients who had been started on dialysis several years ago. However, in a longitudinal prospective study de novo appearance of vascular calcificaitons was observed only in 1 out of 50 dialysed patients, although hyperparathyreoidism and moderate hyperphosphatemia persisted. Vascular calcifications were seen only once in 138 uremic children (56 uremic children without dialysis; 82 uremic children on maintenance hemodialysis). However at autopsy visceral calcifications of the lung were found in three (out of 11) children who did not have vascular calcificaitons on X-rays.

Adolescent↗