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Biomedical subjects

S Nakamoto

Publications and source records attributed to S Nakamoto.

At least 109 records · Page 6Linked to original sources
PubMed1983

Concomitant hepatitis B surface antigen and antibody in thirteen patients.

Both hepatitis B surface antigen (HBsAg) and its antibody (anti-HBs) were found in 13 patients. Nine patients had HBsAg subtype ad, and 7 had anti-HBs monotypic subtype anti-y. Nine patients had HBsAg before detectable levels of anti-HBs were present. Of the 6 patients whose serum contained subtypes of both HBsAg and anti-HBs, 4 had HBsAg before development of the monotypic antibody. All patients have remained positive for HBsAg and anti-HBs (mean duration, 55.5 weeks). Nine patients were positive for HBeAg, and 7 had renal disease. Six of these seven patients are on hemodialysis. Because of the differing subtype specificities of the circulating HBsAg and anti-HBs, we conclude that HBsAg and anti-HBs occur concomitantly. The presence of HBeAg, which indicates infectivity, is common in our study group, suggesting that these patients are a reservoir for transmission of hepatitis-B-virus infection. Therefore, the presence of anti-HBs alone does not indicate a noninfectious serum. Concomitant HBsAg and anti-HBs seems to be particularly common in patients with renal disease who are on hemodialysis.

Adult↗
PubMed1982

Acute effects of hemodialysis on echographic-determined cardiac performance: improved contractility resulting from serum increased calcium with reduced potassium despite hypovolemic-reduced cardiac output.

The hemodialysis session leads to reduction in circulating blood volume (TBV) and arterial pressure (BP) plus correction of electrolyte imbalance. The effect of these alterations on cardiac performance was evaluated in 18 patients with end-stage renal disease. Hemodialysis for 5 hours led to significant reduction (p less than 0.001) in weight TBV, and BP. Neither ejection fraction nor percentage fiber shortening was altered, whereas mean velocity of circumferential fiber shortening (mean VCF) and mean systolic ejection rate (MSER) were both significantly increased (1.17 +/- 0.20 to 1.38 +/- 0.28 circ/sec and 2.38 +/- 0.27 to 2.80 +/- 0.40 EDV/sec, respectively; p less than 0.001 for each). Since both venous return and systolic BP were decreased, increase in velocity of ventricular contraction implies enhancement of cardiac performance beyond what would be expected from alterations in ventricular filling and resistance to ejection. This enhancement is possibly related to concomitant reduction in serum potassium (p less than 0.001) and increase in serum calcium (p less than 0.005) achieved by hemodialysis.

Blood Pressure↗
PubMed1982

Hemofiltration treatment of psoriasis.

Eleven patients with severe psoriasis were treated with hemofiltration once weekly for 4 consecutive weeks. Hemofiltration is a method of extracorporeal dialysis that uses a pressure gradient, rather than passive diffusion, to remove small and medium molecular weight substances from the blood. Six of the patients had very substantial clearing of their psoriatic lesions. Five patients had little or no apparent benefit during the course of hemofiltration treatments. They subsequently had dramatic clearing, however, when previously ineffective topical therapy was resumed. No patient had worsening of his condition during the hemofiltration series, and there were no perceived adverse effects.

Adult↗
PubMed1982

"Pseudo-cap" formation in Ehrlich ascites tumor cells induced by cytochalasin B.

Cytochalasin B (CB) treatment induces or accelerates the capping phenomenon in some cells. In Ehrlich ascites tumor cells (EATC) CB treatment apparently induced the capping of Con A binding sites as observed under a fluorescent microscope. However, electron microscopic examinations revealed that the CB treatment did not induce a rearrangement of Con A binding sites, but rather it only induced a change in cell shape. On the contrary, CB treatment inhibited the capping phenomenon induced by treatment with Con A. Electron microscopic observations may give exact information on the distribution of lectin binding sites.

Animals↗
PubMed1981

Management of end stage polycystic kidney disease with renal transplantation.

Thirty renal transplants have been done in 25 patients with end stage polycystic kidney disease. All but 2 allografts were from a cadaver donor and the average followup was 5 plus or minus 0.9 years. THe 1 and 5-year patient survival rates after transplantation were 76 and 50 per cent, respectively, and allograft survival rates were 63.3 and 39.1 per cent at the same intervals. Of 14 patients at risk for more than 8 years 6 still have well functioning allografts. Nine patients underwent transplantation with both polycystic kidneys in situ and with no adverse sequelae resulting from the retained native kidneys. Despite the risk factors inherent in an older than normal population of cadaver allograft recipients, renal transplantation is an excellent method for treating end stage polycystic kidney disease and holds the prospect for long-term allograft and patient survival rates.

Adult↗
PubMed1981

Movement of plasma membrane proteins of Ehrlich ascites tumor cells in relation to cap formation induced by concanavalin A: a study on the non-capped areas.

In order to get precise information about the movement of plasma membrane proteins in cap formation, cyto- and bio-chemical analyses were made of the plasma membranes from non-capped areas of Ehrlich ascites tumor cells (EATCs) exposed to concanavalin A (Con A). Blebs formed by treatment with cytochalasin B (CB) of the non-capped areas of cells having a cap were isolated and used as the plasma membranes from non-capped areas (ConA-CB-bleb fraction). This bleb fraction was compared with a bleb fraction prepared from cells without ConA-treatment (CB-bleb fraction). Cytochemical analysis of ConA-CB-bleb fraction revealed a decreased in conA binding sites (ConA-BS) compared to the CB-bleb fraction. SDS polyacrylamide slab gel electrophoresis also revealed a decrease in the major components of ConA-BS of the ConA-CB-bleb fraction. The minor components of ConA-BS showed no distinct quantitative difference between the ConA-CB-bleb and CB-bleb fractions. NA+ K+-adenosine triphosphatase (ATPase), 5' nucleotidase (5'ND) and gamma-glutamyl transpeptidase (gamma-GTP) did not show any decrease in activity in the ConA-CB-bleb fraction, but the activity of D+-stimulated phosphatase (K-Pase) was decreased. The findings indicate that there are two types of plasma membrane glycoproteins in EATCs; one includes those participating in cap formation due to ConA, e.g. the major components of ConA-BS and K-Pase, and the other, those not participating in such cap formation, e.g. some minor components of ConA-BS, ATPase, 5'ND and gamma-GTP, which keep their places without moving.

5'-Nucleotidase↗
PubMed1981

A scanning electron microscopic study of the two-step effect of cytochalasin B on Ehrlich ascites tumor cells.

The effect of cytochalasin B (CB) on the surface structure of Ehrlich ascites tumor cells was investigated using the scanning electron microscope. The effect occurs in two steps: formation of zeiotic knobs on the cell surface and subsequent grouping of the knobs at one pole of the cell. The early step of zeiotic knob formation occurs at low concentrations of CB (0.5-1 microgram/ml) at 37 degrees C and at high concentrations of the drug (5-10 microgram/ml) at low temperature but within 1 min at 37 degrees C. This step is only partially inhibited by 5 x 10(-3) M sodium azide. The subsequent grouping of zeiotic knobs lasts for more than 2 min at 37 degrees C and occurs only in the case of high concentrations of CB. It is inhibited by sodium azide and is often associated with grouping of the microvilli, which are then lost from all of the cell surface except the area of knob-grouping.

Animals↗
PubMed1981

Hemodialysis ascites in anephric patients.

Six maintenance hemodialysis patients are described in whom ascites was encountered at a time when they were anephric. No etiology for ascites could be found, and it was presumed that these patients were manifesting so-called "hemodialysis ascites". Our findings suggest that the use of bilateral nephrectomy in the treatment of hemodialysis ascites should be re-evaluated.

Adult↗
PubMed1980

Pharmacokinetics of ceftizoxime in animals after parenteral dosing.

The pharmacokinetic profile of ceftizoxime was studied in mice, rats, dogs, and monkeys given the drug in a single parenteral dose. The serum data after an intravenous injection were analyzed by the two-compartment open model. Cefotiam, cefmetazole, cefotaxime, and cefamandole were used as reference drugs. High concentrations of ceftizoxime were attained in the sera of all test animals and in the tissues of rats after parenteral dosing. The serum concentrations of ceftizoxime were higher than those of the other antibiotics in large animals (dogs and monkeys), but were lower in small animals (mice and rats). About 80% of ceftizoxime was excreted unchanged in the 24-h urine of all species tested. The biliary excretion of ceftizoxime was low: 3.7% in rats and 0.59% in dogs. However, therapeutically significant concentrations of ceftizoxime were found in the bile of dogs. Ceftizoxime was stable in biological fluids such as serum, urine, and tissue homogenates, but cefotaxime was unstable in rat tissue homogenates. Binding of ceftizoxime to serum protein in all species was the lowest of all the antibiotics: 31% for humans, 17% for dogs, and 32% for rats.

Animals↗
PubMed1980

[Mechanism of renal excretion of ceftizoxime in rabbits and dogs (author's transl)].

The mechanism of renal excretion of ceftizoxime was investigated by renal clearance test and stop flow analysis in rabbits and dogs. The serum half life of ceftizoxime after dosing of probenecid and ceftizoxime in combination was about twice longer in rabbits than and almost the same in dogs as that after dosing of ceftizoxime alone. Renal clearance test and stop flow analysis were performed with the following results: (1) Renal clearance of ceftizoxime was about 3.2 times higher in rabbits than and almost the same in dogs as creatinine clearance. (2) Ceftizoxime was scarcely excreted and reabsorbed in the proximal and distal areas of dogs. (3) Ceftizoxime was excreted in the proximal area and not reabsorbed in the distal area of rabbit. These findings indicate that 60% of the urinary excretion of ceftizoxime was obtained through proximal tubule and remaining amount by glomerular filtration in rabbits, and most of the urinary excretion was obtained by glomerular filtration in dogs.

Animals↗
PubMed1979

Hemodynamics of isolated ultrafiltration in chronic hemodialysis patients.

Six patients on maintenance hemodialysis were investigated by direct determination of hemodynamic changes induced by UF. Our results show: 1. Despite a significant fall in ECF and PV, the PV/IF ratio was unchanged indicating absence of major fluid shifts between intravascular and extravascular compartments. 2. The rise in CPV/TBV ratio observed indicates central redistribution of intravascular fluid suggesting venoconstriction. 3. CPV and hence CO was maintained so that a stable MAP resulted.

Blood Pressure↗