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Biomedical subjects

N Ohkohchi

Publications and source records attributed to N Ohkohchi.

At least 73 records · Page 4Linked to original sources
PubMed1995

Viability of partial liver graft from living donor in pigs.

For evaluation of the viability of partial liver graft from a living donor, we investigated energy production of mitochondria and radical scavenging enzyme activities in partial and whole liver transplantation in pigs. The values of adenosine triphosphate (ATP) and total adenine nucleotide (TAN) of the partial liver graft were higher than those of the whole liver graft, whereas the hypoxanthine of the partial liver graft was lower than that of the whole liver graft. There was no statistical difference in the radical scavenging enzyme activities between the two groups. The values of respiratory control ratio (RCR) in both groups were above 3.0 and there was no statistical difference. The survival rates of pigs received partial liver and whole liver graft with 2 to 3 hr cold preservation was 71% and 91%, respectively and there was no statistical difference between two groups. These results suggest that viabilities of the partial liver graft from the living donor are satisfactory enough, compared with those of whole liver graft from a cadaver.

Adenine Nucleotides↗
PubMed1995

[Free radical generation in electron transport system of mitochondria after cold preservation in UW solution].

UNLABELLED: In the liver transplantation one of the causes of primary graft nonfunction is likely associated with lipid peroxidation at reperfusion after cold preservation. In this study, we investigated whether free radicals produced in mitochondrial electron transport system would result in lipid peroxidation after cold preservation in UW solution. MATERIALS AND METHODS: Under anesthesia, the liver of male Wistar rat was flushed via the portal vein with cold Ringer lactate, and then placed in 4 degrees C UW solution for 24 hr. After cold preservation, we examined mitochondrial respiratory control ratio (RCR), free radicals (O2-) from mitochondrial electron transport system by MCLA induced chemiluminescence, and lipid peroxidation by chemiluminescence (CL) after reoxygenation. RESULTS: RCR gradually decreased up to 24 hr preservation. O2- generation from mitochondrial electron transport system was not recognized at any length of the time after cold preservation up to 24 hr. At 6 hr, CL values were slightly higher than those of the control, but significantly decreased at 24 hr. CONCLUSION: O2(-)-generated in electron transport system of mitochondria did not increase with cold preservation up to 24 hr, therefore, the radical from mitochondria did not cause a lipid peroxidation at reperfusion injury.

Adenosine↗
PubMed1994

Rapid fluorometric assay for mitochondrial proton adenosine triphosphatase activity for assessment of viability of liver graft tissue.

We developed an improved determination method of mitochondrial proton adenosine triphosphatase (ATPase) activity in the liver. The activity was measured fluorometrically with a 3,3'-dipropylthiodicarbocyanine iodide (diS-C3(5)), which is excited at 625 nm and emits fluorescence at 670 nm. This dye transmits the electric potential across the inner mitochondrial membrane. The fluorescence intensity of diS-C3(5) with mitochondria (100 microliters, 4-16 mg/ml protein) in a 2 ml potassium buffer (pH 7.4) was regarded as a standard electric potential. After confirming the activity of the mitochondrial electron transport chain by succinic acid (9 mumol), we inhibited the chain by antimycin A (1.25 micrograms). Fluorescence intensity decreased by adenosine 5'-triphosphate (ATP) (2 mumol) and oligomycin (25 micrograms) inhibited this depression. The value of mitochondrial proton ATPase activity was calculated as a percentage of the fluorescence intensity change by ATP per the standard electric potential. The activity of mitochondrial proton ATPase in the normal fresh rat livers was 50.3 +/- 2.2%. Good correlation (r2 = 0.807) between two methods for mitochondrial proton ATPase activity, our newly developed method and a conventional colorimetric method, was obtained in the rat livers with various conditions. This method has advantages that the proton ATPase activity can be measured in intact mitochondria, and all procedures can be completed within 40 min. It is suitable for the determination of mitochondrial viability of liver graft in the hepatic resections and transplantations.

Adenosine Triphosphate↗
PubMed1994

The importance of prevention of sinusoidal endothelial cell injury during cold preservation of liver graft.

We investigated adenosine triphosphate (ATP) synthesis, lipid peroxidation, and activities of radical scavenging enzymes in mitochondria, as well as the ultrastructural morphological changes during cold preservation of swine liver grafts (n = 6) with either Euro Collins (EC) or University of Wisconsin (UW) solutions. The liver, harvested by a standard procedure, was preserved in one of the solutions at 4 degrees C. The values of the total adenine nucleotide and mitochondrial respiratory control ratio (RCR), an index of ATP synthesis, decreased gradually for up to 24 hr during preservation with either of the two solutions and there was no statistical difference between them. Chemiluminescence of mitochondria, an index of lipid peroxidation, in the graft preserved with EC solution or UW solution decreased, and after 24 hr there was no significant difference between the two solutions. Activities of radical scavenging enzymes were well maintained in any of the two solutions. Transmission electron microscopy (TEM) findings showed that the sinusoidal endothelial cells were preserved much better with UW solution than with EC solution even after 12 hr preservation. We concluded that UW solution, more effective for the protection against injuries of the sinusoidal endothelial cells during cold preservation, leads to better results in clinical transplantation, but this solution has no protective effects on energy production, nor radical scavenging enzyme activities of mitochondria. In the maintenance of liver graft viability, protection of the sinusoidal microcirculatory disturbance is more important than that of the mitochondrial function.

Adenosine↗
PubMed1994

[Long-term renal function after nephrectomy in living related kidney donors].

The purpose of this study is to evaluate the long-term renal function of donors after nephrectomy in living related renal transplantation (n = 100). The survival rate of donors was 98% and causes of death in the other 2% were not associated with the donation. Serum creatinine (Scr) and Creatinine clearance (Ccr) deteriorated just after the donation, but gradually improved. The number of donors with proteinuria increased after donation. In Scr and Ccr there was no significant difference between donors with and without proteinuria. In the donors with hypertension (25.3%) mean urine protein was higher than in those without hypertension. There was a correlation between systolic blood pressure and proteinuria. These results strongly suggest that renal function of donors deteriorates once just after the donation, but gradually improves year by year, and that hypertension is strongly associated with renal dysfunction, especially proteinuria, after the donation.

Adult↗
PubMed1993

[Relationship between aseptic necrosis of femoral head bone and immunosuppression therapy, especially CsA administration].

We reviewed 224 patients, who underwent kidney transplantation to investigate relationship between aseptic necrosis (AN) and administration of steroid, Cyclosporin A (CsA), body weight gain. We classified patients into 4 groups by the type of immunosuppressant: the AP group had received Azathioprine (AZ) + Prednisolone (Pre); the CP group, CsA + Pre; the ACP group, AZ + CsA + Pre; and others. There were total 24 AN patients (10.7%). The incidences of AN is 18% in the CP group, 9.3% in the AP group and 0% in the ACP group. In the AP group, weight gain at 1 and 2 month after transplantation and cumulative steroid dose at 3, 4, 5 and 6 month after transplantation correlated with AN. In the patients with AN of the CP and ACP groups, CsA doses per kilogram of body were higher than those in patients without AN at 5, 6 and 12 month after transplantation. In the CP group, the incidence of AN is significantly higher, and administration dose of CsA was higher than that in the ACP group. However steroid dose and body weight gain were lower in the CP group. Therefore AN was associated with CsA in the CP group. In contrast, AN correlated with weight gain and early high cumulative steroid dose administration in the AP group.

Adolescent↗
PubMed1992

Topical antibiotics in cholecystectomy for gallstone diseases.

Efficacy of topical antibiotics in cholecystectomy for gallstone disease was evaluated. Forty-four patients who accepted topical single administration of 1 or 2 g each of latamoxef, cefmenoxime, cefotiam or cefamandole during operation were compared with 36 patients with systemic administration of cefem antibiotics by intravenous drip at a dose of 1 or 2 g, twice daily for postoperative 4 to 7 consecutive days. In topical administration group, concentration of each antibiotic in the gallbladder and common duct bile, gallbladder tissue, parietal peritonea and intra- and postoperative peripheral blood exceeded mostly MIC80 against bacteria usually existing in bile by biliary tract infection or bacteria by wound infection. There was no difference between the two groups in postoperative clinical course. Thus, an adequate prophylactic effect can be expected by topical use of antibiotic during cholecystectomy.

Administration, Topical↗
PubMed1992

Assessment of liver graft function after cold preservation using 31P and 23Na magnetic resonance spectroscopy.

We investigated the functional damages of the cytoplasm and the cell membrane of liver grafts in male Wister Kyoto rats after 24-hr and 48-hr cold preservations using the University of Wisconsin solution in vitro. Fructose (10 mM) or NH4Cl (50 mM) was added to the perfusate, and synthesis of fructose-1-phosphate (F-1-P) and Na- and H-ion transports through the cell membrane were evaluated by magnetic resonance spectroscopy (MRS), 31P-MRS and 23Na-MRS. After 30 min of reperfusion, beta-ATP/(inorganic phosphate: Pi) of the 48-hr preserved group was significantly lower than the control group and the 24-hr preserved group. The changes of F-1-P in the control group and the 24-hr preserved group were almost the same, but F-1-P synthesis was lower in the 48-hr preserved liver than those of the other groups. Intracellular pH began to drop after the cessation of NH4Cl loading, and then it recovered to the preloading level. At the same time Nain+ was increased in the control group. However, in the other two groups, the increasing rates of Nain+ were lower, and the recoveries of Nain+ were less. In conclusion, the function of cell membrane was more fragile than that of mitochondria and cytoplasmic sugar metabolism in the liver graft.

Adenosine Triphosphate↗