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Biomedical subjects

K Kumano

Publications and source records attributed to K Kumano.

At least 109 records · Page 6Linked to original sources
PubMed1994

Minimizing the drainage period for continuous ambulatory peritoneal dialysis.

OBJECTIVES: To examine features of drainage flow and to determine whether the drainage period could be safely reduced in continuous ambulatory peritoneal dialysis (CAPD) patients. DESIGN: Open nonrandomized prospective study in CAPD patients. SETTING: The kidney center in a tertiary care university hospital. PATIENTS: Fourteen CAPD patients with good catheter function. INTERVENTIONS: Drainage flow pattern was studied using a 2-L dialysate. The drainage period was reduced from 28 minutes (mean) to 10 minutes throughout a short-term, 2-month study period and a long-term, 6-month study period for 10 patients. MAIN OUTCOME MEASURES: Ultrafiltration volume, body weight, and peritoneal clearance. RESULTS: A kinetics analysis of the drainage period and volume indicated a positive linear correlation with two different slopes: one for rapid drainage for the first 5-7 minutes and one for subsequent slow drainage. The effluent exceeded 80% in the former period. Ultrafiltration volume and body weight showed no change due to the reduction. Improved peritoneal clearance of small molecular substances could not be confirmed despite a 5% increase in the effective dialysis period. Nearly all patients were satisfied with the reduction and desired its continuation. CONCLUSIONS: Ten minutes is a sufficient drainage period for most CAPD patients with a 2-L dialysate volume. This may possibly allow an increase in daily activities and an effective peritoneal membrane dialysate contact period.

Adult↗
PubMed1993

Usefulness of MRI in the preoperative diagnosis of cervical disk herniation.

We investigated the preoperative diagnostic value of MRI, myelography, and CT myelography (CTM) in a retrospective analysis of 17 patients (15 men and two women) who were surgically treated for cervical disk herniation. Their ages ranged from 29 to 63 years, with a mean of 49 years. Anterior interbody fusion using iliac bone grafts was performed following microscopic diskectomy in all patients. MRI, myelography, and CTM were performed in 13 patients, while four patients were operated on after MRI alone. Neurological improvement was observed in all 17 patients after the surgery. MRI proved useful for determining the level of symptomatic cervical disk herniation. Surgery can be carried out on the basis of MRI findings alone when there is disk herniation at a single level which corresponds with the patient's symptoms and signs.

Adult↗
PubMed1993

Microdiscectomy and second operation for lumbar disc herniation.

To prevent recurrence and avoid the second operation, the authors analyzed the clinical features and surgical outcome of 214 patients (157 males and 57 females) who underwent lumbar microdiscectomy, 16 of whom required second operation. The mean age was 34.6 years (range, 12-62 years). The average follow-up period was 4 years 5 months. The overall incidence of second operation was 7.5%. Second operation was performed because of recurrence of herniation in nine patients, and residual bony compression at the lateral recess in two. The incidence of second operation was significantly higher in teenagers than in patients in other age decades (P < 0.01), and in patients with protrusion-type herniation than in those with extrusion-type or sequestration-type herniation (P < 0.01). To prevent the necessity for second operation, careful and thorough discectomy, especially deep to the posterior longitudinal ligament, and decompression at the lateral recess are useful.

Adolescent↗
PubMed1993

15-Deoxyspergualin "rescue therapy" for methylprednisolone-resistant rejection of renal transplants as compared with anti-T cell monoclonal antibody (OKT3).

A randomized trial with OKT3, an anti-T cell monoclonal antibody or with 15-deoxyspergualin against methylprednisolone-resistant rejection crisis was performed in 25 posttransplant patients immunosuppressed with prednisolone and cyclosporine. At least temporary reversal of rejection was observed in 58.3% of patients treated with 15-deoxyspergualin. This reversal rate may be quite comparable to 61.5% seen in patients treated with OKT3. Adverse effects with 15-deoxyspergualin were related to bone marrow suppression, while those with OKT3 were pyrexia, gastrointestinal symptoms, and herpes infection. In contrast to OKT3, which may act by modulating T cell surface antigen, 15-deoxyspergualin may be effective somewhere in the later stages of the rejection cascade.

Adult↗
PubMed1993

Optimal number of dialysate exchanges in automated peritoneal dialysis.

Means of enhancing the efficiency of dialysis in automated peritoneal dialysis (APD) should be sought. Optimum cycles of exchange in APD were studied using a simple urea kinetic model. The amount of dialysis urea was expressed as the total amount removed divided by the initial plasma level (M/CB). A highly significant correlation between calculated and measured M/CB levels (r = 0.902, p < 0.001) was observed. The kinetic study indicated an increase in cycles to greatly enhance M/CB for high membrane transporter patients, in contrast to low transporters. Maximum M/CB for 8 hours was obtained by 5 cycles at D/P (120 minutes) of 0.4, 6 cycles at D/P of 0.7, and 9 at D/P of 0.9 when 2 L were infused. An increase in infusion volume from 2--3 L augmented M/CB by only 7% at D/P of 0.4, while M/CB was augmented by 14% at D/P of 0.9. The optimum number of cycles may thus be concluded to depend on peritoneal membrane permeability. A high transporter patient requires frequent exchanges for increasing dialysis efficiency, whereas a low transporter patient does not.

Humans↗
PubMed1993

Do cytokine-inducing substances penetrate through dialysis membranes and stimulate monocytes?

Does a relatively low concentration of endotoxin in dialysate, seen in our clinical dialysis, enhance cytokine production of monocytes across high-flux membranes? Several investigators using extremely high concentrations of endotoxin in dialysate maintain that it does. In vitro experiments in this study were conducted to clarify this. Peripheral blood monocytes were isolated from healthy volunteers and incubated for 20 hours. The incubation medium was made of back-filtrates obtained either from Pseudomonas-contaminated water with endotoxin concentration of 621 pg/ml or water with 10 ng/ml or 1 microgram/ml of lipopolysaccharide (LPS), by passing it through a high-flux membrane dialyzer. Endotoxin free water and addition of LPS (0.01 to 10 ng/ml) were used as a negative and positive control. Interleukin-1 beta (IL-1 beta), IL-6 and tumor necrosis factor alpha (TNF alpha) were measured. Back-filtrate from Pseudomonas-contaminated water did not enhance cytokine production, while 50 pg/ml of endotoxin in culture medium induced a significant cytokine production. Back-filtrate of 1 microgram/ml of endotoxin solution marginally increased IL-6 production, but not the other two cytokines. However, none of the cytokines was induced by the back-filtrate of 10 ng/ml of endotoxin. Monocytes isolated from blood following three hour extracorporeal recirculation did not alter the production of cytokines. These results cannot confirm the transfer of cytokine inducing substances across the membrane at a relatively low endotoxin concentration in dialysate. Further study should be made as to the minimal requirement of dialysate purification for preventing monocyte stimulation.

Cells, Cultured↗
PubMed1993

Urea kinetics and clinical features of long-term continuous ambulatory peritoneal dialysis patients.

The purpose of this study was to assess urea kinetic modeling (UKM) as a marker for adequate dialysis in continuous ambulatory peritoneal dialysis (CAPD) patients. UKM was conducted on 19 anuric patients on CAPD for more than 2 years. Serum beta 2-microglobulin (beta 2M) was also measured as a marker of large molecular weight substances. Patient clinical conditions were evaluated by the doctors and patients as well. The patients were thus asked to complete a questionnaire on uremic symptoms and daily activities. A comparison was made in urea kinetics and biochemical parameters based on clinical assessment scores. Patient and doctor scores showed a close correlation (r = 0.69) and were correlated to days of hospitalization. The peritonitis rate was significantly higher in the "not doing well" group. No correlation could be found between indexes of UKM or beta 2M plasma level and clinical assessment scores. A significant correlation was noted between serum albumin concentration and doctor scores (r = 0.52). It was thus concluded that UKM was not a good indicator of the adequacy of dialysis for CAPD, but serum albumin was. However, clinical symptoms and signs are more important than biochemical parameters for assessing adequacy.

Adult↗
PubMed1993

[Protein binding of oral cephems in patients with chronic renal failure].

An assessment was made of the serum protein binding of representative oral cephems (cefdinir, cefixime and ceftibuten) for sera from healthy subjects (HS) and patients with chronic renal failure (CRF) using an application of equilibrium dialysis under a same set of conditions in vitro. The protein binding capacity of oral cephems in CRF patients being treated with continuous ambulatory peritoneal dialysis (CAPD) or hemodialysis (HD) was significantly less than that in HS, and a marked increase in free drug concentration was observed. While examining the protein binding of oral cephems with heparin in patients on HD, binding capacity decreased significantly immediately following the completion of dialysis compared to that prior to dialysis. On the other hand, the protein binding of oral cephems did not change when used nafamostat mesilate as an anticoagulant. The addition of palmitic acid (PA), a common non-esterified fatty acid (NEFA), to pooled sera from HS caused the binding capacity of oral cephems to decrease, accompanied by increase in PA concentration. It appears from these findings that changes in the binding capacity of oral cephems with HD have possibly been caused by increase in NEFA due to activation of lipase when heparin was used as an anticoagulant. In conclusion, changes in the protein binding capacity of oral cephems in CRF patients should be taken into consideration in attempts to avoid possible side effects.

Carrier Proteins↗
PubMed1992

Immunoelectronmicroscopic differentiation of linear IgA bullous dermatosis of adults with coexistence of IgA and IgG deposition from bullous pemphigoid.

BACKGROUND: The differentiation between linear IgA bullous dermatosis (LABD) and bullous pemphigoid (BP) is sometimes difficult in patients who have both IgA and IgG deposition in a linear pattern at the basement membrane zone. OBJECTIVE: We address whether two cases of acquired subepidermal blistering disease with coexistence of IgA and IgG deposition in a linear pattern at the basement membrane zone are LABD or BP. METHODS: The two cases were investigated by immunoelectron microscopy and compared with two typical cases of LABD. RESULTS: In both cases, the deposition of IgA and IgG was ultrastructurally localized below the lamina densa in close association with anchoring fibrils, as was seen in two cases of typical LABD. CONCLUSION: These findings indicate that our two cases of acquired blistering disease with co-existence of IgA and IgG deposition are LABD, rather than BP.

Aged↗
PubMed1992

Rickettsia japonica sp. nov., the etiological agent of spotted fever group rickettsiosis in Japan.

We propose the name Rickettsia japonica sp. nov. (with type strain YH [= ATCC VR-1363]) for a serologically specific species of spotted fever group rickettsiae that are pathogenic for humans (J. Infect. Dis. 159:1122-1126, 1989; J. Clin. Microbiol. 28:1177-1180, 1990). The biologic and genomic characteristics of the organism (G+C content, 31.2 +/- 0.7 mol%) are essentially the same as those of other pathogenic spotted fever group rickettsiae, although the R. japonica isolates cause a persistent infection in Vero cells for many subcultures.

Animals↗
PubMed1992

Diffusion of tosufloxacin into prostatic tissue.

The diffusion of tosufloxacin (TFLX) into the prostatic tissue was studied in 25 patients with benign prostatic hypertrophy. TFLX concentrations in the serum and prostatic tissue were measured at scheduled intervals after oral administration of 450 mg of TFLX on the day before surgery, followed by administration of 150 mg of TFLX immediately before surgery. The mean TFLX levels in prostatic tissue (and tissue/serum levels) at 2, 4 and 6 h were 0.35 +/- 0.16 microgram/g (0.93 +/- 0.36) in 7 patients, 0.58 +/- 0.92 microgram/g (1.10 +/- 0.45) in 10 patients and 0.22 +/- 0.09 microgram/g (0.95 +/- 0.45) in 8 patients. The TFLX levels in prostatic tissue exceeded the minimum inhibitory concentration for several pathogenic bacteria detected in the infected prostatic fluid. Therefore, TFLX shows promise as a useful drug in the treatment of bacterial prostatitis and infections developing after prostatic surgery.

4-Quinolones↗
PubMed1992

[Functional and morphological changes in rat kidney induced by FK506 and its reversal by various vasodilators].

FK506, a newly developed immunosuppressive agent, has recently been used for human liver and kidney transplantation. The present study was carried out to assess the functional and morphological changes by acute or chronic administration of FK506 in heminephrectomized rats. FK506 was given intravenously at the dose of 0.384 mg/kg/hr for 90 min in acute experiment. FK506 was administered by gastric gavage at doses of 1, 2.5, 5 mg/kg for 21 days. Blood and urinary biochemistry were monitored every week. Inulin and PAH clearance studies were conducted during the infusion of FK506 for acute study, and at day 21 for chronic study. Some of the rats were treated with diltiazem (Dilt), captopril or prazosine for 21 days to prevent FK506 nephrotoxicity. Acute infusion of FK506 did not change renal and systemic hemodynamics. Creatinine clearance showed a dose dependent decrease by 10-20% in the rats with chronic administration of FK506. Inulin/PAH clearance indicated a decrease in glomerular filtration rate and renal plasma flow with an increase in renal vascular resistance. The renal histology showed vacuolization in proximal tubuli and media of smooth muscle cells of arterioles. The administration of Dilt functionally and morphologically improved renal impairment induced by FK506. In conclusion, FK506 induces a dose dependent decrease in renal function with significant histological changes in tubuli and arterioles in rat kidney. Intracellular calcium deregulation seems to be involved in FK506-induced nephrotoxicity.

Animals↗
PubMed1992

Quantitative and qualitative changes of serum albumin in CAPD patients.

This study was conducted to assess quantitative and qualitative changes in serum albumin in CAPD patients. For twenty-six CAPD patients as well as age-, sex- and dialysis history-matched HD patients, biochemical and physiological parameters including urea kinetics were determined. Albumin was qualitatively evaluated by HPLC. The CAPD patients showed significant decreases in serum albumin and the reduced form of albumin accompanied by a lower protein catabolic rate(PCR) compared to the HD patients. Thirty five % of CAPD patients showed mild to moderate hypoalbuminemia, associated with a higher incidence of peritonitis and longer hospital stay. Patients with hypoalbuminemia had less of the reduced form of albumin. A weak positive correlation was found between serum albumin concentration and KT/V, and PCR. Thus, in CAPD patients, there occur quantitative and qualitative changes in serum albumin. Hypoalbuminemia may be a risk factor for peritonitis and is due in part to insufficient dialysis and protein intake. Intermolecular change in albumin may possibly be due to uremia per se.

Adult↗
PubMed1992

[Effect of angiotensin II(AII) on peritoneal transport during peritoneal dialysis in rat].

Ultrafiltration volume (UFV) in peritoneal dialysis is expressed as the difference between net transcapillary ultrafiltration (TCUF) and lymphatic absorption (LA) in peritoneal cavity. An increase in LA results in a decrease in UFV. Endogenous hormones may modulate peritoneal membrane permeability and LA. This study was conducted to assess the effect of angiotensin II(AII) on peritoneal permeability and LA in rat. Rats (BW, approximately 300g) with normal renal function were dialyzed for 4 hours using 30ml of hypertonic dialysate (dextrose concentration: 3.86%). AII was added in dialysate at the concentration of 10(-9)-10(-2) mol/30ml. Peritoneal membrane permeability and UFV were studied by clearance of urea N and inorganic phosphate, albumin excretion, glucose absorption and LA. LA was calculated by the concentration change of dextran 70 in dialysate. AII decreased UFV from 15.7 +/- 2.8ml/4hr(control) to 5.7 +/- 1.5(AII 10(-4) mol/dwell). LA was increased in a dose dependent fashion (ED50:0.25 x 10(-6)mol) with no change in TCUF and clearances of urea N and inorganic phosphate. Ten types of AII analogue were used to investigate the site of action for LA in 8 amino acids of AII. [beta-Asp1], [Val5], [Ile3, Val5] and [Sar1] AII showed agonistic action against LA. [Sar1, Thr8], [Sar1, Ile8], [Sar1, Leu8], [Sar1, Ala8], [Sar1, Val5, Ala8] and [Sar1, Gly8] AII had no effect on LA, which found the importance of the 8th amino acid of AII for LA. These actions of AII analogue against LA were similar to those for vascular smooth muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II↗