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Background: Percutaneous ethanol injection therapy (PEIT) effectively suppresses PTH secretion, but the change in the serum calcium and phosphorus product (Ca x P) after PEIT has not been fully evaluated., Methods: Twenty-seven haemodialysis patients with severe secondary hyperparathyroidism (2HPT) were divided into two groups according to their intact PTH (i-PTH) concentrations 6 months after PEIT: (i). effective (E) group, i-PTH concentration <360 pg/ml; and (ii). non-effective (N) group i-PTH > or = 360 pg/ml. The changes in serum calcium and phosphorus concentrations and the Ca x P were recorded for the following 2 years under post-PEIT medical treatment with oral calcitriol or intravenous 22-oxacalcitriol (OCT)., Result: In the E group, the i-PTH concentrations decreased to <300 pg/ml 1 year after PEIT (801+/-302 to 280+/-134 pg/ml), then increased to 435+/-201 pg/ml at 2 years. Serum calcium concentration did not show any significant change except for a transient reduction at 1 month after PEIT. The Ca x P decreased for 1 year (from 66.3+/-15.3 to 56.2+/-10.3 mg(2)/dl(2); P<0.05), in agreement with the course of phosphorus concentration, and continued to be <60 mg(2)/dl(2) up to 2 years after PEIT. The Ca x P tended to decrease more with OCT than oral calcitriol. In the N group, calcium and Ca x P increased significantly at 6 months after PEIT and remained at a high value., Conclusion: Treatment with PEIT suppresses serum PTH concentration as well as Ca x P in the long term.

Secondary hyperparathyroidism (2HPT) is characterized by an abnormal threshold for suppression of parathyroid hormone (PTH) secretion by serum ionized Ca (ICa). It is therefore critical to examine the threshold of PTH secretion in chronic renal failure patients in relation to the physiopathological conditions and the severity of 2HPT. The effect of 1,25-dihidroxy-22-oxavitamin D(3) (22-oxacalcitriol, OCT) on parathyroid gland function was investigated in six haemodialysis patients with 2HPT. OCT was administered three times a week for 26 consecutive weeks. The maximum serum PTH (PTHmax), the minimum serum PTH (PTHmin), and ICa concentration required to inhibit 50% of PTHmax were estimated based on the model formula of the sigmoid curve describing the relationship between ICa and intact-PTH levels. The sigmoid ICa-PTH curves displayed a downward shift at 12 and 26 weeks of OCT treatment. Parathyroid gland function, as reflected by both PTHmax and PTHmin, decreased over time. A steep slope was found at 12 and 26 weeks, compared with that at the start of OCT treatment. There were no marked changes in the set point of calcium. Hypercalcaemia and elevated creatine phosphokinase, probably due to OCT therapy, were observed during the study period. In view of the findings that the sigmoid ICa-PTH curve displayed a downward shift, that both PTHmax and PTHmin decreased, and that functional mass of the parathyroid gland was reduced, OCT appears to be useful in ameliorating parathyroid gland function, contributing to the management of 2HPT.

Bcl-2 may account in part for the maintenance of hypercellularity in human glomerular diseases through preventing cell death and by counteracting bax which may be expressed to regulate excessive proliferation. This process is associated with the effect of PDGF B-chain expression. Bax expression may be important in the cell loss leading to glomerulosclerosis and TGF-beta1 participates in this process by increasing bax expression. Thus, the balance of bcl-2/bax expression may be critical in the course of human glomerular diseases.

Among many substances accumulated or generated by renal failure, much attention has focused on the pathogenetic effects of advanced glycation end-product (AGE)-bound proteins such as AGE-modified beta 2-microglobulin, and bioactive substances such as inflammatory cytokines. In order to remove these substances efficiently, dialysis membranes in the year 2000 should have a higher molecular cut-off point and a sharper cut-off curve, with less formation of concentration polarization, or a greater adsorbing capacity for target substances with less ensuing protein gel layer. Adequate supplementations for depleted substances by more efficient dialysis will be necessary as at present with carnitine and vitamins. Further, from now until the year 2000, membranes in which biocompatibility nearly corresponds to that of capillary endothelium, and safe and economical purification systems of dialysate should be realized.