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Biomedical subjects

K Kamisaka

Publications and source records attributed to K Kamisaka.

At least 37 records · Page 2Linked to original sources
PubMed1990

Degradation and metabolism of indocyanine green: high-pressure liquid chromatographic analysis.

Degradation of indocyanine green solution by exposure to light was studied by high-pressure liquid chromatography. Indocyanine green in an aqueous medium exposed to light changed rapidly into an unknown product. The plasma clearance rate and the biliary excretion rate of the unknown product were much slower than those of indocyanine green. Spectrophotometric scan revealed that the unknown product had almost the same absorption spectrum as indocyanine green. Therefore, if degraded indocyanine green solution were to be used in a liver function test, the clearance of indocyanine green assayed by spectrophotometry would apparently be much lower than that of undegraded indocyanine green. According to fast atom bombardment mass spectrometry, the molecular weight of the unknown product was 723, whereas that of indocyanine green was 775. The analysis of rat bile after injection of indocyanine green by high-pressure liquid chromatography revealed that about 1% of the administered indocyanine green was metabolized in the rat liver.

Animals↗
PubMed1989

Electrophysiological properties of isolated rat liver cells.

The electrophysiological properties of isolated rat liver cells were studied using the patch clamp method in whole-cell configuration. The membrane potential in isolated hepatocytes was -42 +/- 7 mV (n = 20). The input resistance (Rin) and the time constant (tau m) were 51 +/- 17 M (the range of 34 to 180 M omega) (n = 20) and 4.2 +/- 1.0 msec (the range of 3 to 16.5 ms) (n = 20). Assuming that the specific membrane capacitance is 1 microF/cm2, the membrane resistance and membrane capacitance were 42. +/- 9.0 K omega cm2 and 87 +/- 27 pF. These values indicate that isolated rat hepatocytes are not abnormally permeable or leaky. The current-voltage relationship was linear with no rectification. The depolarizing pulse from the resting potential did not induce fast or slow inward currents even when norepinephrine or high Ca2 (3.6 mM) were applied. This indicates that there is no voltage-sensitive Ca2+ channel in the isolated hepatocytes.

Animals↗
PubMed1988

Gel-filtration of serum gamma-glutamyl-transpeptidase with HPLC in hepatobiliary diseases and its significance.

Serum gamma-glutamyl-transpeptidase (gamma-GTP) from patients with various hepatobiliary diseases was fractionated by molecular size using HPLC to investigate the heterogeneity of serum gamma-GTP. Serum gamma-GTP eluted with HPLC showed essentially 3 elution peaks of different molecular size. In the sera of normal patients, there was little gamma-GTP in the high molecular fraction, and most occurred in the low molecular fraction. Intermediate molecular gamma-GTP appeared only in the sera of patients with hepatobiliary disease. In the sera of patients with extrahepatic biliary obstruction, the percentage of high molecular gamma-GTP to total serum gamma-GTP activity was higher than that of other patients. High molecular gamma-GTP increased in the sera of patients with extrahepatic biliary obstruction. Intermediate molecular gamma-GTP appeared in the relatively higher molecular fraction in the sera of patients in whom alcohol consumption might have caused serum gamma-GTP increase, and in the relatively lower molecular fraction in the sera of patients with extrahepatic biliary obstruction. It was concluded, therefore, that the position of elution of intermediate molecular gamma-GTP corresponded to the morbid state. It was shown that intermediate molecular gamma-GTP appeared in the relatively low molecular fraction, corresponding to the increase of serum total bile acids concentration.

Carcinoma, Hepatocellular↗
PubMed1986

[Concentrations of cefmenoxime and cefotiam in the bile and gallbladder tissue following intravenous administration in patients with biliary tract diseases].

To test the effectiveness of cefmenoxime (CMX) and cefotiam (CTM) in patients with biliary tract diseases, concentrations of either antibiotic were measured after an intravenous bolus injection of 1.0 g of CMX or CTM, or simultaneous injection of both (1.0 g each). CMX or CTM was injected in 76 patients with biliary tract diseases (mostly cholelithiasis) prior to a cholecystectomy and concentrations of CMX or CTM were measured by the bioassay (agar well) method at 30 to 60 minutes after the injection. Average concentrations of both CMX and CTM in gallbladder bile and gallbladder tissue sufficiently exceeded the minimal inhibitory concentration (MIC) against main causative organisms of biliary tract infections. Concentrations of both antibiotics in gallbladder bile were significantly higher in patients with patent cystic ducts than with obstructed cystic ducts. Concentrations of both antibiotics in the gallbladder tissue reached at a similar high level regardless of the patency of the cystic ducts, but concentrations were lower in severely inflamed gallbladders. CMX and CTM were administered alternatively (cross-over fashion), or simultaneously (combined) to 13 patients with T-tube drainage or percutaneous transhepatic cholangio-drainage, and concentrations of both antibiotics in bile from the drainage tube were measured by high performance liquid chromatography at hourly intervals after the injection. Concentrations of both antibiotics were far greater than MICs against main attributable microorganisms in biliary tract infections. The concentration of CMX slightly exceeded that of CTM. Concentrations of both antibiotics were lower in bile of patients showing abnormally high serum GTP, A1-P, and total bilirubin levels than in bile of patients with normal values of these variables. It is speculated that the secretion of both antibiotics in the bile may decrease in cases with severe hepatic failure, but effective concentrations of both antibiotics in the gallbladder tissue should be maintained as long as the blood circulation in the gallbladder was maintained.

Aged↗
PubMed1985

Study of bilirubin metabolism by high-performance liquid chromatography: stability of bilirubin glucuronides.

The stabilities of bilirubin (BR) glucuronide, monoglucuronide (BMG), and diglucuronide (BDG) were studied under various conditions by HPLC. In aqueous media, BMG showed a pronounced lability and was easily transformed into equimolar BDG and BR. It was proved by direct analysis of tetrapyrrole isomers that BDG and BR were formed from dipyrrole exchange of BMG molecules. All reducing agents examined (sodium ascorbate, cysteine, GSH, dithiothreitol, NADH, and NADPH) suppressed the transformation of BMG into BDG and BR. Bovine serum albumin and rat liver cytosol fractions also stabilized BMG strongly. BDG was fairly stable in aqueous media as compared with BMG. When BMG was incubated both with and without liver plasma membranes (N2 fraction) from Wistar rats, the formation rates of BDG and BR in both incubation mixtures were exactly the same. The composition of BDG and BR isomers was the same in both mixtures. Also, heat denaturation of the plasma membranes did not affect formation rates. Moreover, the reaction was completely inhibited by sodium ascorbate. These findings indicate that rat liver plasma membranes have no enzyme activity for BDG formation from BMG.

Animals↗
PubMed1979

[Ligandin].

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Glutathione Transferase↗