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Biomedical subjects

J Zingraff

Publications and source records attributed to J Zingraff.

At least 73 records · Page 4Linked to original sources
PubMed1988

Influence of haemodialysis membranes on beta 2-microglobulin kinetics: in vivo and in vitro studies.

Amyloidosis of the beta 2-microglobulin (beta 2M) type is a recently recognised complication of dialysis. We studied plasma and ultrafiltrate beta 2M in 36 chronic haemodialysis patients. Long-term dialysis with standard cuprophan membrane in non-oliguric patients and with the AN69 polyacrylonitrile membrane in oliguric patients resulted in lower plasma beta 2M concentrations (means +/- SD, 24.4 +/- 6.6 and 33.0 +/- 8.2 micrograms/ml, respectively) than with cuprophan in oliguric patients (47.0 +/- 13.2 micrograms/ml, P less than 0.01). In acute studies, plasma beta 2M (corrected for haemo-concentration) increased, although not significantly, during cuprophan dialysis (n = 10) from 40.6 +/- 12.2 to 44.8 +/- 7.6 micrograms/ml and decreased during AN69 dialysis (n = 10) from 39.4 +/- 18.0 to 24.3 +/- 7.1 micrograms/ml (P less than 0.02). After 15 min ultrafiltration, beta 2M sieving coefficient in vivo was 0.33 for AN69 but near zero for cuprophan. Total mass transfer of beta 2M across the AN69 membrane during a 4-h dialysis was 142 +/- 45.8 mg (n = 7). AN69, but not cuprophan, membrane fragments incubated in vitro with normal or uraemic plasma exhibited avid [125-I] beta 2M binding (respectively 12.9% vs 0.47% and 6.09% vs 0.06% of total beta 2M bound at 30 min, n = 6, P less than 0.001 for both). No in vitro generation of beta 2M from whole normal or uraemic blood could be demonstrated during incubation with either membrane.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

[Amyloidosis in hemodialysis patients].

Amyloidosis in long-term haemodialysis patients mainly involves the osteo-articular system. It is held responsible for carpal tunnel syndrome, chronic arthralgia and various types of arthropathy, chronic synovitis and tenosynovitis, haemarthrosis, subacute polyarthritis and destructive arthropathies of the limbs and spine. Radiologically, amyloidosis may appear as bone cavities, particularly visible in the hips and wrists. Its frequency increases with the duration of haemodialysis. Biochemically, amyloidosis consists of beta 2-microglobulin (beta 2-M). This protein accumulates in uraemic patients under dialysis and seems to play a major role in the pathogenesis of amyloid deposits. The accumulation is due to renal impairment, being maximum in anuric patients. However, the unsatisfactory clearance of beta 2-M by dialysis methods also contributes to its retention: the production and elimination of beta 2-M seems to vary according to the extrarenal clearing technique. These data suggest that improvements in clearing techniques will eventually prevent dialysis amyloidosis.

Amyloidosis↗
PubMed1987

Hemodialysis-associated amyloidosis and beta-2 microglobulin. Clinical and immunohistochemical study.

The beta-2 microglobulin type of amyloidosis was identified in articular and para-articular tissues of 14 patients with non-amyloid nephropathies undergoing long-term hemodialysis. Ten patients had carpal tunnel syndrome, 13 had juxta-articular radiolucent cysts (complicated by spontaneous fractures of the femoral neck in three), and six had destructive arthropathies of the large joints of the limbs. Massive amyloid deposits were found in the synovium, capsule, ligaments, articular cartilage, and/or bone. They were characterized by Congo red-induced green birefringence that was sensitive to potassium permanganate treatment. They reacted with anti-beta-2 microglobulin antiserum, whereas they did not react with antibodies directed against AA protein, prealbumin, or immunoglobulins. These data suggest that the potentially disabling arthropathy of hemodialysis is due to amyloid lesions. The persistently elevated plasma beta-2 microglobulin levels may play a role in the pathogenesis of this recently recognized complication, and if so, this complication should be preventable.

Aged↗
PubMed1987

Effect of calcitriol in the control of plasma calcium after parathyroidectomy. A placebo-controlled, double-blind study in chronic hemodialysis patients.

Severe, prolonged hypocalcemia in observed in some, but not all, hemodialysis patients after parathyroidectomy performed because of uncontrolled hyperparathyroidism. The aim of the present study was to investigate whether calcitriol and calcium supplementation in the immediate period after parathyroidectomy (days 1-14) was of more help in the control of plasma calcium than calcium supplementation alone. Fourteen hemodialysis patients were enrolled in a prospective, randomized, double-blind and placebo-controlled study. From the day after parathyroidectomy, 7 patients received calcitriol and the remaining 7 a placebo using incremental doses adjusted to the degree of hypocalcemia (up to 4 micrograms/day for calcitriol). Plasma calcium, phosphorus, alkaline phosphatase and immunoreactive parathyroid hormone levels before parathyroidectomy were comparable in both patients groups, as was the lowest plasma calcium achieved after parathyroidectomy. The decrease in plasma calcium after parathyroidectomy was related to plasma alkaline phosphatase and to the number of osteoclasts and osteoblasts on bone biopsy surface before parathyroidectomy. The mean decrement of plasma calcium (days 3-9) as compared to that before parathyroidectomy was less pronounced in calcitriol-treated than in placebo-treated patients (0.25 +/- 0.06 versus 0.45 +/- 0.05 mM, mean +/- SEM, p less than 0.025). Treatment with placebo was interrupted before day 14 because of persistent severe hypocalcemia in 4 of 7 patients, whereas calcitriol treatment was continued in all 7 patients up to 14 days. Patients on calcitriol treatment required less mean calcium supplements (days 1-9) than patients receiving placebo (37.4 +/- 3.2 versus 49.4 +/- 3.7 g, p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Calcitriol↗
PubMed1987

Hypocalcaemic effect of WR-2721, S-2 (3-aminopropylamino) ethyl-phosphorothioic acid in an anuric haemodialysis patient.

The radio- and chemoprotective agent, S-2 (3-aminopropylamino) ethyl-phosphorothioic acid (WR-2721) has been reported to lower hypercalcaemia in patients with cancer, probably by increased renal calcium excretion and decreased parathyroid hormone (PTH) secretion and bone calcium resorption. The present study reports the first clinical use of WR-2721 in an anuric haemodialysis patient with severe secondary hyperparathyroidism. The drug was administered intravenously at different doses, i.e. 150, 300, and 500 mg/m2. The infusion was followed by a striking decrease of plasma immunoreactive (i) PTH within 30 min. The nadir of the iPTH decrease was reached at 60 min and was followed by a steady return to previous values. Serum ionised calcium decreased more progressively from 1.55 mmol/l initially to 1.30 mmol/l at 4 h after the 300-mg dose, remained at that level at 24 h, but rose again to pre-infusion values after 48 h. The extent and duration of the decrease in plasma iPTH and ionised calcium were dose-dependent. The circulating iPTH at 24 h was inversely related to the corresponding plasma ionised calcium concentration and had risen above preinfusion values at that time. Plasma concentrations of three other hormones, i.e. renin, insulin, and prolactin, were not affected by the administration of WR-2721. In conclusion, WR-2721 can induce a decrease in serum ionised calcium in the absence of any excretory kidney function. The rapid effect of the drug on circulating iPTH supports the notion of an interference with PTH secretion or catabolism.

Amifostine↗
PubMed1987

Tissue distribution of dialysis amyloidosis.

Twenty-three uremic patients on intermittent hemodialysis for eight to eighteen years provided the material for the present pathological study. In all of them, there was evidence for dialysis related amyloidosis based on previous clinical or histological findings or both. The material examined consisted of nine skin biopsies, five abdominal fat aspirates, eight trans-iliac bone biopsies and numerous post-mortem specimens of various visceral organs from eight cases. None of the skin biopsies or fat aspirates showed amyloid deposits. In only one bone biopsy could a small Congo red positive area be recognized that showed characteristic birefringence under polarizing light. Autopsy material findings were negative except for one case: this patient had been dialyzed for 18 years. Very minute amyloid deposits with a positive immunofluorescence staining for beta 2-microglobulin (beta 2-M) were found in the walls of small vessels from her lung, heart, liver and intestine. Thus, in chronic hemodialysis patients the accumulation of beta 2-M amyloid fibrils in tissues other than joints and juxta-articular structures appears to have a low incidence, to occur lately and to be of limited size. Although extra-articular amyloid deposits may progressively occur and extend with increasing survival time on dialysis, tiny deposits such as those observed in only two of our patients will hardly lead to serious complications.

Aged↗
PubMed1986

Evaluation of parathyroid autograft growth and function in hemodialysis patients.

The aim of our study was to evaluate the function and growth of parathyroid tissue autografted into the forearm of hemodialysis patients using several presently available methods. In a dynamic study, the secretory function of autografted tissue was evaluated in seven patients using either zero calcium dialysate or calcium infusion. In an additional prospective study, seven patients had repeated determinations of plasma immunoreactive parathyroid hormone (iPTH) concentration on samples from both forearms, a radionuclide evaluation of autograft function using thallium-201 chloride, and real time ultrasonography. Light microscopy analysis was performed in two patients. The dynamic study demonstrated that induction of hypocalcemia was followed by an increase, and induction of hypercalcemia by a decrease, in circulating iPTH in both forearms using three different radioimmunoassays, similar to what has been reported for normal parathyroid tissue. A significant gradient (ie, greater than 2.0) of plasma iPTH concentration in samples from both forearms was observed in only three out of the seven patients of the prospective study. Two of these patients disclosed an increased uptake of 201TI chloride at the site of autografted tissue and had an echographically detectable mass. In both, hyperplastic parathyroid tissue was removed. At present, the remaining third patient does not have other features of recurrent hyperparathyroidism. In conclusion, autotransplanted parathyroid tissue of hemodialysis patients shows an adequate response to physiologic stimuli such as hypo- and hypercalcemia. Dynamic tests, therefore, appear to be a useful tool in the assessment of its function. In addition, radionuclide and echographic studies may be reliable adjuncts in the detection of marked parathyroid autograft hyperplasia.

Adult↗
PubMed1986

Value of the 99mTc-methylene diphosphonate bone scan in renal osteodystrophy.

The value of radionuclide bone scanning in the diagnosis of renal osteodystrophy is still debated. In order to re-examine this issue, 25 uremic patients treated by intermittent hemodialysis underwent 99m-Technetium Methylene Diphosphonate (99mTc-MDP) bone scan. They were subdivided into three groups according to quantitative bone histology. Group 1 (N = 8) had pure dialysis osteomalacia, group 2 (N = 7) mixed lesions, and group 3 (N = 10) pure osteitis fibrosa. The scintigraphic studies were interpreted by means of a five point semi-quantitative scale. Using this quantification, all but one group 1 patients had decreased bone tracer uptake, and all patients of group 3 had an increased uptake (chi square test of Yates, P less than 0.001). Among patients of group 2, bone uptake was decreased in the three patients with clearly reduced mineralization front and moderate osteitis fibrosa, but it was increased in all patients with severe osteitis fibrosa and subnormal mineralization front. A quantitative analysis of regional tracer uptake into bone was performed in two patients: one of group 2 and one of group 3. The results obtained clearly corroborated the semi-quantitative findings. Thus, in hemodialysis patients with symptomatic bone disease, the 99mTc-MDP bone scan provides useful information for the differential diagnosis between dialysis-related osteomalacia and secondary hyperparathyroidism. In patients with mixed lesions, the importance of bone tracer uptake appears to depend on the extent of the mineralization front and on the intensity of osteitis fibrosa.

Adult↗
PubMed1986

Plasma digitalislike activity in essential hypertension or end-stage renal disease.

Plasma extracts from 119 subjects showed a digitalislike activity, as evidenced by the ability of these extracts to inhibit ouabain binding to the Na+-K+ pump. High levels of the digitalislike compound were found in 18 of 54 untreated hypertensive subjects, 7 of 21 normotensive subjects with a family history of hypertension, and 10 of 14 patients with end-stage renal failure. Dialysis significantly reduced the activity of this compound. These results suggest 1) that endogenous digitalislike factor is not directly linked to hypertension but rather is related to sodium balance and 2) that it neither originates nor is activated by renal tissue, as it was present in four of six anephric patients.

Adult↗