Search

Aim: Serum uric acid (UA) concentration is regulated by its production in the liver and/or intestine and its rate of excretion from the kidneys. However, little is known about skeletal muscle involvement in determining the physiological UA level. The present trial explores whether muscle strength and/or muscle volume is associated with UA levels., Material & Methods: Muscle strength was evaluated in terms of grasping power calculated as an average of right and left hand measurements in relation to other parameters in 14,333 subjects (median age; 41.2 years), who were recruited to the study. Skeletal muscle volume was calculated based on the bioimpedance method by subtracting estimated fat volume plus estimated bone weight from the total body weight., Results: 1) Multiple regression analyses to explain the association with UA levels (dependent variable) revealed that BMI, BUN, triglyceride, muscle strength, AST, age and sex are independent variables. 2) Higher UA levels (assessed as 4 UA quartiles) are associated with higher muscle volume, muscle strength, BMI, DBP, and serum creatinine (Cr) concentration. 3) Greater DBP (assessed as 2 UA categories) was associated with higher BMI, muscle strength, muscle volume, UA levels and serum Cr concentration. 4) Regression coefficient "t" for muscle strength was the largest among the other parameters including serum Cr concentration in the UA level ranging from 5.5 to 6.5 mg/dL., Conclusion: There was an association between muscle strength/volume and UA levels in the near physiological UA range, suggesting that the circulating UA levels can be, at least in part, controlled by its production in the skeletal muscles.

A study was conducted to determine whether combination treatment using allopurinol and benzbromarone was more useful than single allopurinol treatment for the gout and hyperuricemia accompanying renal dysfunction. The subjects were 45 male patients who received urate-lowering treatment and showed a stable serum urate level. The patients were divided into four groups according to the urate-lowering treatment and creatinine clearance (Ccr) (A group: single treatment, normofunction, B group: single treatment, hypofunction, C group: combined treatment, normofunction, D group: combined treatment, hypofunction). There were no differences in serum urate levels among the four groups. Urate clearance (CUA)and daily urinary urate excretion (UUAV) showed significantly high values in the C group, but no difference was seen in the fractional excretion of urate (FEUA) among the four groups. The dosage of allopurinol in the D group was significantly lower than in the A and B groups. Serum oxypurinol concentration in the C group was lower than that in the B group. Oxypurinol clearance (C oxypurinol) in the C group was significantly high compared with the B and D groups. There was a close correlation between C oxypurinol, Ccr, and CUA, with an especially strong correlation between C oxypurinol and CUA. There were no differences in the serum concentration and clearance of xanthine and hypoxanthine among the four groups. Results of the study suggested that combination treatment using allopurinol and benzbromarone for the gout and hyperuricemia accompanying renal dysfunction is more useful, because a lower dose of allopurinol can be used and the serum oxypurinol concentration is reduced compared with single allopurinol treatment.

A-34-year-old man with a 16-year history of proteinuria was successfully treated with cyclosporin A (CsA). He was diagnosed as having membranoproliferative glomerulonephritis (MPGN) by renal needle biopsy and was treated with dipyridamole. In July 1992, he was readmitted for the treatment of anasarka. Although conventional predonisolone was administered for 5 months after one cycle of methyl-predonisolone pulse therapy, his nephrotic state did not improve. Immediately after the cessation of this treatment, he was given CsA 3 mg/kg/day. A marked reduction in proteinuria and edema occurred during the use of CsA for 6 months, with a reduction in the fractional excretion of protein. The nephrotic condition of this patient was subsequently stable without massive proteinuria despite the discontinuation of CsA at least for several months. These findings suggest that CsA monotherapy may be useful in patients with MPGN and steroid-resistant nephrotic syndrome.

Primary nephrotic syndrome can, although infrequently, cause severe anemia. However, the mechanisms of the anemia remain unknown. We investigated the mechanism of anemia in nephrotic syndrome by measuring parameters of nephrotic syndrome and anemia in 44 nephrotic patients (male: female; 21:23, average age; 43.6 +/- 20.3 years). Nephrotic patients had significantly lower hematocrits than did healthy controls (43.3 +/- 3.7 vs. 46.8 +/- 3.4% in males, 37.4 +/- 3.5 vs. 40.8 +/- 2.8% in females). Serum erythropoietin (Epo) concentrations were correlated inversely with hemoglobin (Hb), hematocrit (Hct), and red blood cell corpuscle (RBC) counts. Furthermore, serum Epo correlated with the serum iron concentration, but not with the other parameters, such as reticulocytes, serum protein and proteinuria. However, the maximum Epo concentration was less than 100 mU/ml in spite of severe anemia, and this was thought to be inappropriate. On the contrary, urine Epo was not detected by the same method of serum Epo determination in spite of aggressive dialysis with distilled water. When four patients with severe anemia were subcutaneously administered recombinant Epo 6,000 unit two times a week, they showed marked improvement in Hb/Hct/RBC. The precise mechanism of anemia in NS was not elucidated by this investigation, but further study should clarify the causes of the inappropriately low concentration of serum Epo in patients with primary nephrotic syndrome.

To investigate some of the problems associated with pregnancy and delivery in lupus nephritis, 13 pregnancies in 7 patients with inactive lupus nephritis and 5 pregnancies in one patient with primary antiphospholipid syndrome (PAPS) were compared with 36 pregnancies in 22 patients with primary nephrotic syndrome (NS). Furthermore, a follow-up survey during 0-8 years was made with 12 babies born to mothers with lupus nephritis. Some pregnancies during lupus nephritis were accompanied by disease exacerbation and worsening of renal function. There was a higher incidence of babies born with a low birth weight, and the incidences of fetal loss or premature birth and toxemia were higher in lupus nephritis than in NS. The number of babies with a low birth weight was significantly higher in patients with pregnancy-induced hypertension or skin lesion due to lupus erythematosus. The presence of antibodies against SSA/RO in the mother was associated with the occurrence of congenital heart block. Birth weight of babies born to mothers with lupus nephritis was low, but there were no statistical differences in the growth of babies after 6 months of age compared with babies born to normal women.

We treated hyperlipidemia in patients with nephrotic syndrome (NS) using pravastatin for more than one year. There were 7 cases consisting of 3 with minimal change nephrotic syndrome (MCNS), 1 with focal glomerulosclerosis (FGS), 1 with proliferative glomerulonephritis (PGN), 2 with membranous glomerulonephritis (MGN) and 1 of unknown origin. Three cases consisted of frequent relapsers, and 4 were steroid-resistant. Six randomly selected age- and sex-matched nephrotic patients were used as controls. The daily excretion of proteinuria was not decreased after pravastatin treatment, but, the serum albumin rose from 3.1 +/- 1.1 to 3.4 +/- 1.0 mg/dl. The serum total cholesterol level was significantly reduced from 401 +/- 174 mg/dl to 331 +/- 103 mg/dl in spite of an absence of marked change in the control group. However, there were no significant changes in the triglyceride and lipoprotein levels. The atherogenic index was 7.1 +/- 3.7 before and 2.8 +/- 1.7 after pravastatin treatment, respectively. Improvement of renal function defined by delta decrement of renal function per year (0.08 +/- 0.06 vs. 0.12 +/- 0.26) was observed after the discontinuation of pravastatin administration in 3 out of 4 intractable cases. We conclude that pravastatin has a potent effect in reducing the serum level of total cholesterol, but not triglyceride in NS. Furthermore, pravastatin can induce renal dysfunction especially in patients with intractable nephrotic syndrome.

Male Syrian hamsters were used to evaluate cadmium (Cd)-induced nephrotoxicity. Furthermore, they were treated with polyaspartic acid (PAA) in an attempt to prevent renal damage due to Cd. To induce renal proximal tubular damage, the hamsters were administered a single subcutaneous injection of cadmium chloride (CdCl2) at the dose of 3 mg/kg body weight. Within 24 hours, they exhibited significant proteinuria and an increased urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG). Renal histological changes consisted of degenerative changes in renal tubule cells, irregularly shaped nuclei with marginated chromatin and rounded mitochondria. The administration of PAA did not improve creatinine clearance or urinary protein excretion. The concentration of Cd in the renal tissue showed a gradual increase on day 3 following cadmium exposure. Cadmium nephrotoxicity appears to be more severe in Syrian hamsters than in rats or mice. Thus, this animal model appears to be excellent for studying Cd-induced nephrotoxicity.

We evaluated short term clinical effects of intravenous cyclophosphamide (iv CyP) therapy performed by every three month in 7 patients with steroid-resistant lupus nephritis. Significant improvements were observed in daily urinary protein excretion (3.1 to 0.83 g/day), creatinine clearance (65.4 to 95.3 ml/min), CH 50 levels (20.8 to 37.4 U/ml), and anti-DNA antibody titer (26.6 to 7.0 U/ml). In addition, the mean daily dose of prednisolone (PSL) could be markedly reduced from 38.6 mg to 13.9 mg at the final observation. Two patients suffered from Herpes Zoster infection at a few months after ivCyP therapy, however this incidence were not considered as critical side effect which reached to the discontinuation of this therapy. We concluded that ivCyP therapy by every three months were safety and achieved beneficial clinical effects on steroid-resistant lupus nephritis as far as short observation. On the contrary, the long term effect of this mode of therapy is to be defined.

The soluble interleukin-2 receptor (SIL-2R) levels in 46 patients with primary nephrotic syndrome were examined. The values in the nephrotic patients exceeded those in healthy controls (p less than 0.05), and were the same at the nephrotic and non-nephrotic stages. The serum interleukin-2 (IL-2) levels in the nephrotic patients were low and did not correlate with the serum SIL-2R levels. Only at the nephrotic stage were the latter closely correlated with the serum IgG (p less than 0.001) but not with the serum IgA or IgM. The SIL-2R production by phytohemagglutinin stimulated peripheral blood lymphocytes (PBL) in the nephrotic patients was less at the nephrotic and non-nephrotic stages than that in the healthy controls. The IgG production by pokeweed mitogen stimulated PBL was low at the nephrotic stage but not at the non-nephrotic stage. Based on these findings, it is suggested that SIL-2R determinations should prove useful in clarifying the relationship between cellular and humoral immunological disorders in nephrotic syndrome.

Acute renal failure (ARF) associated with primary nephrotic syndrome (PNS) was analyzed clinically in order to evaluate the mechanism of onset. The incidence of induced ARF with PNS was found to be cases (2.1%) out of 420 cases attending our outpatient clinic. The renal histological changes included 2 cases of minimal change nephrotic syndrome (MCNS), 6 of focal glomerular sclerosis (FGS) and one of unknown origin. The 6 cases which recovered from ARF were designated as group A. The 3 cases of group B required maintenance dialysis; they included one case of MCNS, one of FGS and one of unknown origin, and showed resistance to aggressive treatments, such as steroid pulse therapy, anticoagulants and plasmapheresis. In the patients of group A, follow up studies for 10 years confirmed that their condition was not progressive. There were no significant differences between the reversed group A cases recovering from ARF and the non-reversed group B cases in terms of their clinical parameters, such as age, sex, urinary protein excretion, initial renal function, blood pressure, renal histological damage and complications. Specific factors associated with the induction of reversibility from ARF could not be identified. Further research is needed to elucidate the precise characteristics of the ARF occurring in PNS.