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Biomedical subjects

W Kamiike

Publications and source records attributed to W Kamiike.

11 recordsLinked to original sources
PubMed1992

Primary malignant lymphoma of the spleen.

We treated two patients with primary splenic malignant lymphoma. One was a 63-year-old man with diffuse histiocytic non-Hodgkin's lymphoma accompanied by multiple liver metastases which were composed of necrotic tissue probably due to preoperative transarterial chemoembolization (TAE). He eventually died of liver failure two years and six months after splenectomy. The autopsy revealed that a large part of the cirrhotic liver had been occupied by a diffuse-type hepatocellular carcinoma, but no recurrence of the malignant lymphoma was found in the liver or other organs. The second patient was a 40-year-old woman with a massive invasion of the stomach, colon, pancreas, and diaphragm by a splenic tumor. The splenic tumor and the adjacent involved organs were resected. Pathologically, well-differentiated diffuse lymphocytic non-Hodgkin's malignant lymphoma was evident. No recurrence has been found for six years and two months. Based on an evaluation of the 71 patients with primary splenic malignant lymphoma reported to data in Japan, the patients treated by a curative resection in an early clinical stage have a more favorable prognosis.

Adult↗
PubMed1989

Different patterns of leakage of cytosolic and mitochondrial enzymes.

The mechanisms of leakage of intracellular enzymes, and especially the cytosolic and mitochondrial isozymes of aspartate aminotransferase (AST), in ischemic rat liver were studied. On recirculation of ischemic liver, cytosolic AST (cAST) promptly appeared in the blood. Release of cytosolic enzymes, including cAST and lactic dehydrogenase, resulted from disruption of blebs that protruded from parenchymal cells into the sinusoidal space. When these blebs were formed in ischemic liver, mitochondria still remained in core regions of the injured cells and were not found in the blebs. Consistent with this fact, mitochondrial AST (mAST) did not leak into the circulation from ischemic liver until most of the cAST had leaked out. This delayed leakage of mitochondrial enzymes was also consistent with the fact that the mitochondrial membranes maintained a diffusion barrier against matrix enzymes even after anoxia for 2 h, when their oxidative phosphorylation capacity had been lost. These results indicate that mitochondrial enzymes are liberated into the blood only after appreciable disintegration of the cells, probably necrosis, and that the cumulative activity of mAST in the blood should reflect the extent of necrosis in ischemic organs better than that of cAST.

Animals↗
PubMed1989

Involvement of Ca2+ release and activation of phospholipase A2 in mitochondrial dysfunction during anoxia.

During anoxic incubation, depletion of mitochondrial ATP was followed by release of Ca2+ with concomitant increase in the rate of state 4 respiration due to disruption of the diffusion barrier against protons. The external addition of ATP and its non-metabolizable analog, beta,gamma-methylene adenosine 5'-triphosphate, prevented both the release of Ca2+ and increase in the rate of state 4 respiration. Addition of EGTA, which did not prevent release of the ion, resulted in little increase in the respiration rate. Addition of an inhibitor of mitochondrial phospholipase A2, such as quinacrine, dibucaine, or chlorpromazine, also prevented increase in the respiration rate without affecting Ca2+ release from mitochondria during anoxic incubation. Non-esterified polyunsaturated fatty acids were also found to be liberated from anoxic mitochondria. External addition of the ATP-analog, EGTA, and inhibitors of phospholipase A2 suppressed the liberation of non-esterified polyunsaturated fatty acids. Melittin and Ca2+, which activate phospholipase A2, increased the rate of state 4 respiration and the liberation of fatty acids. These findings support the hypothesis proposed previously that the following sequence changes occurs in mitochondria during anoxia; depletion of ATP, liberation of free calcium from mitochondria, and disruption of the diffusion barrier against H+ of the inner membrane. The results also indicate another event; activation of phospholipase A2 by release Ca2+ which results in H+ leakiness of the inner membrane.

Animals↗
PubMed1988

Adenine nucleotide metabolism and its relation to organ viability in human liver transplantation.

The relationship between adenine nucleotide metabolism and ischemic damage was studied in human liver. Thirty transplanted grafts were divided into two groups according to their functional outcome. Cellular adenine nucleotide levels were assayed by high-performance liquid chromatography. During cold ischemia, the adenosine triphosphate (ATP) level was not correlated with graft function, but two grafts with low total adenine nucleotides (TAN) levels showed poor function after transplantation. After recirculation, the ATP level showed good recovery in grafts that functioned satisfactorily (n = 24, 5.47 +/- 1.51 mumol/g dry weight), but remained low in poorly functioning grafts (n = 6, 3.30 +/- 1.68 mumol/g dry weight) (P less than 0.01). The level of recovery of ATP was inversely related to the period of warm ischemia during implantation (P less than 0.01). Bile production, used as a parameter of initial function, was observed shortly after implantation in 17 of 24 grafts that functioned satisfactorily, but in only 1 of 6 poorly functioning grafts. It is concluded that loss of adenine nucleotides and lack of bile production during transplantation are good markers of damaged grafts in human liver transplantation.

Adenine Nucleotides↗
PubMed1987

Levels of purine compounds in a perfusate as a biochemical marker of ischemic injury of cold-preserved liver.

Biochemical markers of ischemic injury of rat liver were studied in an extracorporeal perfusion system. During anoxic perfusion, purine compounds appeared in the perfusate as soon as they were formed in the liver and their recovery in the perfusate balanced the loss of adenine nucleotides from the liver. In contrast, cytosolic aspartate aminotransferase did not appear in the perfusate at slow rates of liver perfusion or during hypothermic perfusion. The production of purine compounds was further investigated in hypothermically preserved liver in connection with the restoration of some metabolic functions of liver. The amount of purine compounds released into the perfusate was found to be closely related to the degrees of damage of the hepatic functions of gluconeogenesis, ureogenesis, and mitochondrial respiration on reperfusion. These results indicate that release of purine compounds into the perfusate is a good marker of ischemic damage.

Adenine Nucleotides↗
PubMed1985

Correlation between cellular ATP level and bile excretion in the rat liver.

The influence of the cellular level of adenosine triphosphate (ATP) in the liver on bile excretion was studied in rats. In ischemia, the cellular ATP level decreased rapidly--and, concomitantly, bile flow stopped within 5 min. Administration of L-ethionine i.p. to rats reduced the bile flow rate with decrease in the cellular ATP level. The correlation between the bile flow rate and the cellular ATP level was confirmed in a liver perfusion system. On anoxic perfusion, the ATP level and bile flow rate changed in the same manner as in ischemia. The recovery rates of both on reoxygenation decreased with increase in the anoxic perfusion period. During perfusion under oxygenated conditions, decrease in cellular ATP to various levels by infusion of various concentrations of potassium cyanide, an inhibitor of respiration, resulted in corresponding and concomitant suppression of bile excretion. Kinetic analysis of the bile flow rate revealed a Michaelis-Menten-type curve for the cellular ATP level. The apparent Kms for ATP of bile flow rate in L-ethionine-treated rat liver and liver perfused with potassium cyanide were 1.0 and 1.6 mM, and their Vmax values were 4.1 and 2.5 microliter/min/g liver, respectively. The concentrations of main bile components, such as phospholipids, cholesterol, and taurocholate increased, but their total outputs decreased with decrease in the ATP level, and returned to the normal range with recovery of the ATP level. Thus, it was shown experimentally that the extent of hepatic injury can be assessed simply by monitoring the bile flow rate, which reflects the cellular level of ATP.

Adenosine Triphosphate↗
PubMed1983

Decrease in mitochondrial levels of adenine nucleotides and concomitant mitochondrial dysfunction in ischemic rat liver.

The process of mitochondrial dysfunction in ischemic rat liver was studied. A close correlation was found between decrease in the mitochondrial adenine nucleotide content and deterioration of oxidative phosphorylation capacity. The level of total adenine nucleotides, which was 15--20 nmol/mg protein in mitochondria isolated from normal liver, fell to 1--2 nmol/mg protein with concomitant loss of oxidative phosphorylation capacity after anoxic incubation in vitro or in vivo for 120 min. However, neither the permeability barrier to adenine nucleotides nor matrix enzymes were affected under these conditions. The loss of adenine nucleotides was ascribed to degradation of AMP to adenosine and then leakage of the latter. Conventional procedures for maintenance of oxidative phosphorylation capacity of isolated mitochondria, preservation in the cold and addition of ATP or a respiratory substrate under aerobic conditions, were very effective in maintaining the intramitochondrial levels of adenine nucleotides. Of the three species of adenine nucleotides, only AMP was ineffective in maintaining mitochondrial function; mitochondria containing more than 5 nmol of ATP plus ADP/mg protein exhibited normal activity of oxidative phosphorylation, but with less than 2 nmol they showed no activity.

Adenine Nucleotides↗
PubMed1982

Changes in cellular levels of ATP and its catabolites in ischemic rat liver.

The cellular levels of adenine nucleotides and their metabolites in ischemic rat liver were assayed by high pressure liquid chromatography with high theoretical plate numbers. The method was sensitive enough to measure all the metabolites in about 1 mg of tissue, and to examine changes in their levels in a single liver in ischemia. In ischemia the cellular level of ATP decreased rapidly. Concomitantly there was a transitory increase in AMP, followed by its degradation to allantoin via adenosine with accumulation of all species of purine catabolites. NAD was also degraded gradually with concomitant accumulation of nicotinamide. Thus, the level of total adenine nucleotides decreased during ischemia and the amount of this decrease ws equal to the sum of the amounts of catabolites produced. The ATP level was rapidly restored on recirculation after an ischemic period of less than 15 min. However, recovery of the ATP level was depressed by prolonged ischemia and was not observed after an ischemic period of 2 h. Intermediate purine catabolites that accumulated in ischemia were also cleared during recirculation either by their removal in the blood flow or by further oxidative degradation, but they were not salvaged for reuse until the cellular level of ATP was restored. Administration of allopurinol resulted in marked accumulation of hypoxanthine in ischemic liver, but neither this drug nor chlorpromazine had any appreciable effect on recovery of the ATP level during recirculation.

Adenine Nucleotides↗
PubMedDate not supplied

Vertebral aneurysm of the neck.

We recently encountered a case of a huge vertebral aneurysm involving the entire right neck, extending from the clavicle to the mandibular area. The patient had undergone laminectomy of the cervical spine at age 45 for neuritis or spinal caries. This operative procedure apparently caused a small vertebral laceration and produced the giant aneurysm. The aneurysm was resected under hypothermia in order to protect the brain. One vertebral artery was ligated, but cerebral damage did not occur. Only a few cases of huge aneurysms extending from the clavicle to the mandible have been reported in the literature.

Aged↗