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Biomedical subjects

K Kumano

Publications and source records attributed to K Kumano.

At least 127 records · Page 7Linked to original sources
PubMed1992

Dietary protein loading and the oral adsorbent AST-120 in the progression of chronic renal failure in the rat.

Excess protein intake enhances the progression of renal failure. The oral carbonaceous adsorbent, AST-120, was found experimentally and clinically to retard the progression of renal failure. This study was designed to determine whether deterioration of renal function by dietary protein loading can be prevented or mitigated by this oral adsorbent. Rats with uremia induced by partial renal infarction were fed a normal or high-protein diet for 70 days with or without AST-120, in which the inorganic phosphate content was adjusted to the same level. The survival rate deteriorated with the high dietary protein, but was improved from 30% to 100% with AST-120. Dietary protein loading reduced renal function, based on creatinine clearance. AST-120 improved renal function and renal histopathology not only in the normal diet group but in the high-protein group as well. The progression of renal failure induced by protein loading is thus shown to be prevented by oral AST-120. The mechanism for its action remains to be clarified.

Administration, Oral↗
PubMed1992

Beta 2-microglobulin synthesis of mononuclear cells in chronic dialysis patients.

Beta 2 microglobulin (B2M) has been identified as a major component of amyloid deposits. This study was designed to determine whether changes occur in the synthesis of B2M in dialysis patients. Mononuclear cells (MNC) were isolated in peripheral blood from healthy volunteers, patients on hemodialysis (HD) and on continuous ambulatory peritoneal dialysis (CAPD). MNC were cultured in a medium of RPMI 1640 with or without interleukins IL-1, IL-2 or interferon INF-r. B2M in the cultured cells and supernatant was measured by enzyme immunoassay. IL-2 or INF-r stimulated B2M synthesis was significantly lower (25%) in patients on HD than in normal controls regardless of the type of dialysis membranes used, with no change in basal B2M synthesis. No differences were detected between healthy volunteers and CAPD patients. Preincubation of MNC with complement--activating or non-complement--activating membrane had no influence on B2M synthesis. The basal B2M synthesis of MNC significantly increased after a 4-hour HD regardless of the membranes used, and IL-2 and IFN-r stimulated synthesis were both essentially the same before and after HD. It was thus concluded that maximum capacity for B2M synthesis of MNC decreases in hemodialysis patients. This low responsiveness of MNC may be partially the cause for the reduction in cell-mediated immune response in HD patients.

Adult↗
PubMed1992

[Is there any correlation between urea kinetics and the clinical outcomes in CAPD patients?].

Urea kinetic modeling was applied to 19 CAPD patients followed in our outpatient clinics. Serum beta 2-microglobulin was also measured as a marker of large molecular weight substances. Clinical conditions of patients were assessed by both doctors and patients. Patient's assessment were done by the questionnaire. Indices of urea kinetics (KT/V, PCR) and biochemical parameters were compared between well-treated and not well-treated patients judging from patient's and doctor's assessment scores. The rate of peritonitis was significantly higher in the latter group. None of the parameters were different between 2 groups except for serum albumin. There was a significant correlation between serum concentration of albumin and doctor's assessment score (gamma = 0.52). In conclusion, urea kinetic parameters is not a good indicator for adequacy of dialysis in our CAPD population. Serum albumin seems to be one of the indices for adequate dialysis. However, clinical symptoms and signs are more valuable than biochemical parameters for the assessment of adequacy of dialysis.

Adult↗
PubMed1992

[Effect of oral adsorbent AST-120 in rats with chronic renal failure--mechanism of progression of renal failure by dietary protein].

Progression of renal insufficiency was evaluated in partially nephrectomized Sprague-Dawley rats at the age of 10 weeks, fed on the low (6%), usual (20%), and high (36%) protein diet (group 6C, 20C, and 36C). Effects of oral adsorbent AST-120 on these experimental uremic models were also examined (group 6A, 20A, 36A). All the rats underwent paired feeding, and survived during the experimental period of 3 weeks. GFR (inulin clearance) and RPF (para-amino hippurate clearance), as well as Ccr was measured before the sacrifice. Initial serum creatinine and Ccr were 1.7 mg/dl and 0.27 ml/min. The rats of group 36C showed progressive elevation of serum creatinine level and decrease in Ccr. At the end of the study, GFR was significantly lower in group 36C than in group 6C and 20C (0.19, 0.68, 0.87 ml/min respectively). Significant elevation of filtration fraction in group 36C suggested that the decrease in GFR mainly resulted from low RPF. Even in group 36C, no glomerular sclerosis was histologically demonstrated in the remnant kidney, and the mean planar area of the remnant glomeruli was significantly small, which might reflect low RPF. Tubulo-interstitial changes like dilatation of the urinary space and tubular epithelial flattening were prominent in group 36C. Beneficial effect of AST-120 was obvious in high protein diet groups. GFR and RPF were rather well preserved in group 36A (0.36 and 0.78 ml/min) with normal filtration fraction. Tubulo-interstitial damage was evidently mild in group 36A. These data suggested the presence of some humoral factors, which can be adsorbed by AST-120 in gastrointestinal tract, and responsible for the deterioration of renal function and tubulo-interstitial damage induced by high protein diet in the uremic condition. Besides hyperfiltration and glomerular hypertrophy, such humoral factors as suggested in this study may contribute to the progression of chronic renal failure to some extent.

Adsorption↗
PubMed1991

Cotrel-Dubousset pedicle screw system for various spinal disorders. Merits and problems.

Eighty-five consecutive patients with various spinal disorders who underwent surgery using the Cotrel-Dubousset pedicle screw system at Kantoh Rosai Hospital between August 1986 and November 1989 were studied. The group included 52 men and 33 women, ranging in age from 19 to 76 years, with an average age of 53 years. The postoperative follow-up period was from 15 to 54 months, with an average of 33 months. The diagnoses were lumbar degenerative disorders in 69 cases (spondylolisthesis in 32, lumbar degenerative spinal canal stenosis without spondylolisthesis in 21, and "unstable lumbar spine" in 16), spinal trauma in 9, spinal deformities in 5 (scoliosis in 3 and kyphosis in 2), and tumor in 2 (1 spinal cord tumor and 1 vertebral tumor). The Cotrel-Dubousset pedicle screw system proved not only to be useful in fixing an unstable spine from the lower thoracic vertebra to the sacrum, as is the case with the other pedicle screw systems, but also to have great advantages for use in various spinal disorders, including reduction of slipped vertebra, correction of spinal deformity combined with a hook system, and for anterior spinal instrumentation. Postoperative clinical results were good in most of the cases, but pseudarthrosis considerably affected the results in a few cases. Therefore, great care must be taken, both strategically and technically, to prevent pseudarthrosis.

Aged↗
PubMed1991

Serologic survey of spotted fever group rickettsiosis on Hainan Island of China.

A serosurvey for antibodies to Rickettsia japonica was conducted on Hainan Island of China. Serum specimens were collected from 1,030 outpatients at hospitals in different parts of the island regardless of their diagnosis. Only two among 538 serum specimens collected in Baoting and Tongshi counties, located in the southern part of the island, were demonstrated to contain antibodies reactive with R. japonica at a high dilution. The specimens also reacted with R. rickettsii at the same titer as with R. japonica. These two specimens reacted with other pathogenic spotted fever group (SFG) rickettsiae to a lesser extent. On the other hand, the specimens were shown to possess antibodies reactive with R. typhi at a significantly lower dilution or were not reactive at all. The findings suggested the occurrence of an SFG rickettsiosis on Hainan Island. More than half of the serum specimens collected from patients with suspected rickettsial infections in the southern area were found to contain IgM and IgG antibodies to R. typhi, indicating a high incidence of murine typhus.

Antibodies, Bacterial↗
PubMed1991

[Pathological study on the effect of oral adsorbent AST-120 on chronic renal failure in rats].

In order to evaluate the direct or indirect effect of AST-120 on chronic renal failure (CRF) in rats, histological and electron microscopical examinations were performed. A total of 30 Sprague-Dawley rats (aged 11 weeks and weighing 226 to 229 gm) with CRF induced by 5/6 nephrectomy were prepared. Rats were fed by a commercial diet (CE-2, Japan Kurea) and were divided into two groups: A (16 rats) and B (14 rats). AST-120 (5% content) was only administered to group B. After two months, kidneys were removed and prepared for the histological and electron microscopical examinations. On histological examination, group A kidneys showed severe glomerular hyalinization (more than 80%) and frequent crescents, as well as tubulo-interstitial fibrosis and many protein casts. In contrast, segmental glomerular lesions were identified in group B kidneys. Tubulo-interstitium were also well preserved. Furthermore, the ultrastructural findings of group B were milder than that of group A. The preservation of renal tissue in group B revealed the beneficial effect of AST-120 on CRF rats' kidneys. In conclusion, this beneficial effect is provided by the removal of the serum toxic metabolite (uremic toxin) and the precursor substance of the toxin by orally administered AST-120.

Administration, Oral↗
PubMed1991

[Protein binding of various cephems in healthy subjects and patients with chronic renal failure].

This study was employed to investigate whether the serum protein binding of various cephems [cefpiramide (CPM), cefalotin (CET), latamoxef (LMOX)] differ among healthy subjects and patients with chronic renal failure (CRF) by means of in vitro equilibrium dialysis. The protein binding capacities of cephems in patients with CRF (hemodialysis, continuous ambulatory peritoneal dialysis, non-dialysis) decreased significantly compared to those in healthy subjects. The binding capacities correlated directly with total protein, albumin concentration and correlated inversely with blood urea nitrogen and serum creatinine concentration. In the study of protein binding during and after hemodialysis, the binding capacities of CPM and LMOX decreased immediately after dialysis and then increased with the time. However, the binding capacities of CET increased immediately after dialysis and then decreased. The binding capacities of CPM and LMOX correlated inversely with non-esterified fatty acids (NEFA) and those of CET correlated directly with NEFA. In the study of protein binding in pooled sera from healthy subjects with or without palmitic acid (PA), the binding capacities of CPM and LMOX decreased by increasing the concentration of PA, while those of CET increased by increasing PA up to 3 mM. The changes in binding capacity of cephems during and after hemodialysis have been possibly caused by increase of NEFA due to activation of lipase in use of heparin as an anticoagulant. In conclusion, changes in protein binding capacity of cephems in sera from CRF, which should be taken into consideration to avoid possible side effects.

Adult↗
PubMed1990

Long-term continuous ambulatory peritoneal dialysis. Mass transfer and nutritional and metabolic stability.

Long-term mass transfer and nutritional and metabolic stability of end-stage renal disease patients maintained on continuous ambulatory peritoneal dialysis (CAPD) continue to be of concern. This study longitudinally monitored 43 Japanese CAPD patients (29 males, 14 females) from three centres within the Tokyo Metropolitan Area for an average period of 15 +/- (SD) 8 months. The mean time for patients on CAPD at study initiation was 18 +/- 15 months. Monitored parameters included urea and creatinine mass transfer coefficients, clearances and blood levels, ultrafiltration, lipid levels, dietary protein intake, and weight. Lipid data were also gathered retrospectively from patient records from the time of CAPD initiation. The results were analyzed using regression growth curve analysis and analysis of variance. Statistically significant linear rises with time were apparent only for the creatinine mass transfer coefficients, although this was not considered clinically significant in terms of changes either in peritoneal creatinine clearances or ultrafiltration. Serum cholesterol levels were found to rise significantly above pre-dialysis levels 11 months after CAPD onset, thereafter returning to levels not significantly above baseline levels. In summary, CAPD provided stable, acceptable treatment over the study period.

Adult↗
PubMed1990

Abnormal accumulation of vanadium in patients on chronic hemodialysis therapy.

Vanadium (V) has been reported to inhibit a number of enzyme activities such as those of Na(+)-K(+)-ATPase. The main excretory pathway of this element is via the kidney. These facts led us to study the V distribution in uremic patients. As a result, hemodialysis patients at our dialysis center exhibited extremely high levels of serum V (23.9 +/- 11.3 ng/ml, n = 43) as compared with healthy adults. Nondialysis patients did not show increased serum V concentrations. The V contents were significantly elevated in the skin and in the aortae of hemodialysis patients. It was found that the tap water from Kanagawa prefecture, Japan, had the highest V concentrations among the 21 cities in Japan and the US. In conclusion, oral ingestion of V-contaminated water has likely caused an accumulation of the metal in patients with end-stage renal failure.

Adult↗
PubMed1990

[The effect of donor specific blood transfusion (DST) on graft survival--intermittent coverage of cyclophosphamide].

Donor specific blood transfusion (DST), given prior to living related kidney transplantation has resulted in significant improvement in graft survival. This improvement, however, has been accomplished with a high rate of adverse sensitization against the donor. In an attempt to reduce the incidence of sensitization, we have employed DST with intermittent coverage of cyclophosphamide. A comparative study was done between 2 methods of DST with or without the coverage of immunosuppressant for prospective kidney transplant recipients from living related donors. In addition, the beneficial effect of DST on graft survival was evaluated in our recent series of living related transplantation using cyclosporine A (CsA) as postoperative immunosuppression. Twenty-nine prospective kidney transplant patients received 200 ml of fresh whole blood 3 times at 2 week intervals from HLA one-haploidentical living related donors. The first 13 patients received DST alone, while the remaining 16 were given cyclophosphamide (CPM 1.5 mg/kg/day) for 3 days prior to each DST. In patients with CPM coverage, 6.3% (1 of 16) developed positive T-warm antibody against donor and 15% of patients (2 of 13) with DST alone developed it. Like-wise 19% (3 of 16) of the former and 38% (5 of 13) of the latter became positive B-warm crossmatch. The difference in sensitization rates between these 2 groups was not statistically significant. Nineteen patients receiving DST were compared to 21 non-DST patients in incidence of acute rejection, graft function and graft survival with the same immunosuppressive regimen, such as CsA, prednisolone, and mizoribine.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1989

Protective effect of piperacillin against the nephrotoxicity of cisplatin in rats.

The protective effect of piperacillin against the nephrotoxicity of cisplatin was compared with that of fosfomycin in Fischer 344 rats. Blood urea nitrogen, serum creatinine, and morphological changes were evaluated as the renal toxicological parameters. Rats receiving 2 mg of cisplatin per kg of body weight for 5 days showed significant (P less than 0.01 by multiple-comparison test) elevation of blood urea nitrogen and serum creatinine concentrations compared with rats receiving saline alone and also exhibited development of cell lesions in the pars recta of the tubules in the outer stripe of the outer medulla. However, piperacillin (250 and 1,000 mg/kg) significantly (P less than 0.01 by multiple-comparison test) reduced these toxicological parameters in comparison with results for cisplatin alone. The protective effect of piperacillin was superior to that of fosfomycin, although platinum levels in the kidney were higher with the combination of cisplatin and piperacillin than with cisplatin plus fosfomycin. Although the nephrotoxicity of cisplatin was also reduced when cisplatin was administered concomitantly with sodium chloride in mole-equivalents to 250 and 1,000 mg of piperacillin per kg, its protective effect was less than that of the corresponding piperacillin dose. These results suggest that piperacillin may have a role as a protective agent against the nephrotoxicity of cisplatin.

Animals↗