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Biomedical subjects

Y Kamiyama

Publications and source records attributed to Y Kamiyama.

At least 253 records · Page 14Linked to original sources
PubMedDate not supplied

Biological significance of enhanced mitochondrial membrane potential in regenerating liver.

Liver mitochondrial membrane potential was assessed during regeneration following partial hepatectomy in rabbits. Absorbance change of safranine O per milligram of mitochondrial protein was used to evaluate mitochondrial membrane potential. Absorbance change was calibrated to the membrane potential in millivolts produced by valinomycin-induced potassium diffusion potential. At 24 hr after hepatectomy, absorbance change of safranine O per milligram of mitochondrial protein increased from 15.0 +/- 2.2 X 10(-3) to 37.4 +/- 3.3 X 10(-3) per mg (p less than 0.005). This represents a mitochondrial membrane potential increase from 77.0 +/- 4.6 to 124.4 +/- 6.7 mV. Phosphorylative activity increased from 59.9 +/- 5.0 to 106.1 +/- 7.4 nmoles ATP synthesized per mg per min (p less than 0.005). The enhancement of phosphorylative activity was closely linked to the elevation in liver mitochondrial membrane potential (r = 0.77, p less than 0.005). We suggest that elevation of mitochondrial membrane potential, coupled with enhanced oxidative and phosphorylative activities, plays an important role in the regeneration process following hepatectomy.

Adenosine Triphosphate↗
PubMedDate not supplied

Pituitary hemorrhage in hemolytic uremic syndrome.

A 5-year-old girl with hemolytic uremic syndrome is reported with pituitary hemorrhage in the acute phase. Seizures, hemiplegia, and transient blindness were observed. These symptoms cannot be attributed to the pituitary hemorrhage; however, pituitary hemorrhage should be added to the list of neurologic lesions that can occur in hemolytic uremic syndrome.

Cerebral Hemorrhage↗
PubMedDate not supplied

Gonadal function in patients with testicular germ cell tumors.

The gonadal function of 18 patients with testicular germ cell tumors was evaluated. Seminal parameters after orchiectomy were examined in 15 patients. Six of them were available for follow-up observation after 2 or 3 courses of adjuvant chemotherapy. Serum gonadal hormones before and after orchiectomy were evaluated in 7 patients (testosterone and PRL were not examined in one patient). Five of 15 (33.3%), 8 of 15 (53.3%), 13 of 15 (86.7%), 7 of 13 (53.8%), and 9 of 12 (75.0%) had abnormal values in seminal volume, sperm concentration, motility, morphology, and vitality, respectively. The sperm concentration gradually improved after chemotherapy following orchiectomy in 5 of 6 (83.3%) patients. In all the patients examined, serum levels of follicular stimulating hormone (FSH), luteinizing hormone (LH), and prolactin (PRL) increased after orchiectomy. Serum levels of testosterone increased in 4 patients, but decreased in 2 after orchiectomy. These findings suggest that several factors, including preexisting intrinsic defect and disturbance of the hypothalamus-pituitary-gonadal axis, are involved in the deterioration of gonadal function in patients with testicular germ cell tumors.

Adult↗
PubMedDate not supplied

Adaptive increase of respiratory enzymes in the mitochondria from cirrhotic livers of patients and rats, and its relationship to glucose tolerance.

Oxidative phosphorylation and respiratory enzyme concentrations of liver mitochondria and glucose tolerance were studied in 12 cirrhotic patients and CCl4-induced cirrhotic rats. The cirrhotic patients with normal or higher concentrations of cytochrome a(+a3) showed parabolic glucose tolerance test (GTT) patterns having return of blood glucose level somewhat toward normal within two hours and tolerated major operations well, while three patients with cytochrome a(+a3) concentrations less than 60 per cent of normal (0.81 +/- 0.02 (mean +/- SEM) X 10(-10) moles/mg protein) could not tolerate even minor operations. In CCl4-induced cirrhotic rats, cytochrome a(+a3) concentrations varied from 1.5 to 3.0 X 10(-10) moles/mg protein as compared with 1.8 +/- 0.1 of controls. In mitochondria with normal or higher concentrations of cytochrome a(+a3), the oxidative and phosphorylative activities per unit of cytochrome a(+a3) were negatively correlated with cytochrome a(+a3) concentrations. These rats tolerated partial hepatectomy well. However, in cirrhotic rats with subnormal cytochrome a(+a3) concentrations there was a high mortality following hepatectomy. The former showed parabolic GTT patterns, while the latter showed nonparabolic GTT patterns.

Adult↗
PubMedDate not supplied

Effect of hepatocyte volume on energy status in the cirrhotic rat liver.

To evaluate the effect of reduced hepatocyte volume on liver energy status, the relationship between the morphologically quantified hepatocyte volume and biochemical parameters, and the difference in nuclear density between the parenchyma and stroma were assessed in rat livers with thioacetamide-induced cirrhosis. The ratio of hepatocytes to whole liver tissue, defined as the 'hepatocyte area ratio', and the nuclear densities of the parenchyma and stroma were calculated microscopically with an image analysing system. Adenine nucleotide, protein and DNA contents, and the ornithine carbamoyltransferase activity in the liver were assayed. In the cirrhotic group, adenine nucleotide content, protein content and ornithine carbamoyltransferase activity were positively correlated with the hepatocyte area ratio, whereas DNA content was negatively correlated with this ratio. The adenylate energy charge of the cirrhotic liver was maintained at a constant level regardless of the ratio. Adenine nucleotide content, protein content and ornithine carbamoyltransferase activity per fractional 'hepatocyte area ratio' in cirrhotic livers were significantly lower than in control livers. The nuclear density of the stroma was significantly greater than that of the parenchyma. These results suggest that the lowered energy status in the cirrhotic liver is not caused by reduced hepatocyte volume but rather by impaired hepatocyte metabolism. In addition, the morphological measurement with an image analysing system was found to be useful for evaluating the effects of decreased hepatocyte volume on biochemical derangements in cirrhotic tissue.

Adenine Nucleotides↗
PubMedDate not supplied

The accumulation and energy load of exogenous lipids in cirrhotic rat liver after partial hepatectomy.

BACKGROUND: The suitability of three energy substrates, glucose, medium-chain triglycerides (MCT) and long-chain triglycerides (LCT), was studied in cirrhotic rats after a partial hepatectomy. METHODS: Rats with thioacetamide-induced cirrhosis underwent a 70% hepatectomy, and were divided into three groups. Each group was then injected with 14C-labeled glucose, 14C-labeled MCT or 14C-labeled LCT, respectively. The subsequent tissue distribution of 14C and the cumulative amount of expired 14CO2 were determined. In a second experiment, the 70%-hepatectomized cirrhotic rats received total parenteral nutrition (TPN). The source of the nonprotein calories was 100% glucose (glucose group), 60% MCT + 40% glucose (MCT group), and 60% LCT + 40% glucose (LCT group). The adenylate energy charge and the glycogen content in the liver remnant were determined. RESULTS: The tissue distribution of 14C revealed that the fat emulsions accumulated preferentially in the liver. One hour after the partial hepatectomy, the concentration of 14C-labeled MCT in the liver remnants was threefold higher than in sham-operated controls. Similarly, the concentration of 14C-labeled LCT was twofold higher. The adenylate energy charge in the glucose group with TPN recovered to preoperative levels within 1-hour after the partial hepatectomy, whereas the LCT group with TPN showed a 24-hour delay in their recovery. The MCT group with TPN exhibited an intermediate time course. CONCLUSIONS: It is suggested that the specific accumulation of MCT and especially LCT emulsions in the cirrhotic liver remnant acts as an energy load rather than an energy substrate.

Adenine Nucleotides↗
PubMedDate not supplied

Diagnostic capability and rational resectional surgery for early gallbladder cancer.

Gallbladder carcinoma limited to the mucosa (pT1a) or muscularis proper (pT1b) with no lymph node metastasis (stage I) is defined as early carcinoma of the gallbladder. Eleven patients with early carcinoma of the gallbladder, treated by either simple or extended cholecystectomy (cholecystectomy plus wedge resection of the gallbladder bed of the liver and lymphadenectomy), were reviewed to determine the diagnostic capability and to clarify the rational resectional procedure for this stage of the disease. A definitive pre-operative diagnosis was made in only 2 patients with pT1b tumors. Most of the remaining 9 patients were diagnosed incidentally after cholecystectomy for polyps or stones. Among 7 patients with pT1a tumors, 5 underwent simple cholecystectomy and 2 underwent extended cholecystectomy. All 7 patients survived with a recurrence-free condition for 5 years or more following the operation. Two patients with pT1b tumors, however, died of a local recurrence or bile duct carcinoma following simple cholecystectomy. Two patients with pT1b tumors who were correctly diagnosed before the operation and underwent extended cholecystectomy survived without recurrence. It is concluded that patients with pT1a tumors can be successfully treated by simple cholecystectomy, while patients with pT1b tumors require extended cholecystectomy.

Adult↗
PubMedDate not supplied

Changes in peritoneal equilibration test values during long-term peritoneal dialysis in peritonitis-free children.

Little is known about the changes in peritoneal equilibration test (PET) values in children on long-term peritoneal dialysis (PD). In the present study, a PET was carried out every 6 months in 39 children (mean age 8.8 +/- 5.5 years) undergoing PD for 6 to 85 months (mean 36.9 +/- 23.1 months). Patients experiencing peritonitis were excluded. Both D/P creatinine (dialysate-to-plasma ratio of creatinine at 4 hours) and D/D0 glucose (ratio of dialysate glucose at 4 hours' dwell time to dialysis glucose at 0 dwell time) were measured 195 times in this series of patients. No remarkable change was found for D/P creatinine or D/D0 glucose during the first 24 months of PD but thereafter, D/P creatinine increased gradually and D/D0 glucose decreased gradually. Mean D/P creatinine increased significantly after the first 24 months of PD: from 0.66 +/- 0.12 during the first 24 months, to 0.70 +/- 0.09 after 25 months and more of PD (p = 0.0051). Mean D/D0 glucose decreased significantly after 24 months of PD: from 0.42 +/- 0.09 during the first 24 months, to 0.38 +/- 0.08 after 25 months and more of PD (p = 0.0015). The most significant change for both D/P creatinine and D/D0 glucose occurred after 24 months of PD. It seems reasonable to consider the mean PET values at 24 months of PD as the standard PET values.

Adolescent↗