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T Hashizume

Publications and source records attributed to T Hashizume.

At least 145 records · Page 8Linked to original sources
PubMed1992

[Evaluation of 99mTc-PMT delayed imaging in diagnosis of hepatocellular carcinoma].

99mTc-PMT delayed imaging was performed on 199 patients with hepatocellular carcinoma (HCC), and 72 patients with various hepatic diseases, from which HCC should be differentiated. Of the 199 patients with HCC, 128 (64.3%) showed positive results on 99mTc-PMT images. Of these 128, 102 (51.3%) showed increased uptake of radioactivity by the hepatic tumor as compared with the surrounding non-tumorous area of the liver, and 26 (13.1%) showed equal uptake. On the contrary, only 2 (9.1%) of the 22 patients with other malignant hepatic tumors (7 with cholangiocellular carcinoma and 15 with metastatic liver tumors) showed equal uptake of 99mTc-PMT. These findings indicated that 99mTc-PMT delayed imaging was useful for increasing the specificity in diagnosis of HCC. Of the patients with HCC showing increased uptake on 99mTc-PMT images taken 5-hour after the injection of the radioisotope, 26.3%, 69.6%, and 96.0% showed intense 99mTc-PMT uptake by hepatic tumor on 1-hour, 2-hour, and 3-hour images, respectively. These findings indicated that in diagnosing HCC, 5-hour image should be taken only in the patients with a hepatic tumor showing no increased uptake of radioactivity even on 3-hour image. Moreover, the rate of HCC to take up 99mTc-PMT intensely was higher in patients with hepatic tumor showing filling defect on colloid liver image than in those showing no filling defect (p less than 0.001). The points in the assessment of radioactivity uptake by hepatic tumor on 99mTc-PMT delayed image were as follows: Overlapping of radioactivity excreted into the gall bladder or intestine with the radioactivity of the liver tumors, radioactivity retention in the non-neoplastic portion of the liver, and the radioactivity of the dilated intrahepatic bile duct were noted in 6 (2.6%), 15 (6.5%) and 9 (3.9%), respectively, among the 230 patients with focal space occupying lesions. Further, a patient of giant nodular regenerative hyperplasia showed increased uptake of 99mTc-PMT consistent with the hepatic lesion.

Carcinoma, Hepatocellular↗
PubMed1992

[Comparison of exercise capacity evaluated by cardiopulmonary exercise test and hemodynamic parameters in patients with atrial septal defect].

We evaluated the maximal exercise tolerance using cardiopulmonary exercise testing, and investigated the relation of the hemodynamic parameters such as mean pulmonary artery pressure (PAm) and pulmonic-to-systemic flow ratio (Qp/Qs) to exercise tolerance in 18 adult patients consecutively. All the patients had atrial septal defect (ASD). Maximal oxygen uptake (VO2 max) averaged only 21.6 +/- 5.6 ml/min/kg and 63.5 +/- 16.2% of the predicted values (VO2max). And anaerobic threshold averaged 12.5 +/- 2.3 ml/min/kg and 56.7 +/- 12.4% of the predicted values. There were 2 patients who had marked pulmonary hypertension (PH, PAm more than 44 mmHg). Maximal exercise tolerance of these patients was severely impaired, and %VO2max was only 45.9% and 46.2% respectively. In patients without PH (PAm less than 20 mmHg), however %VO2 max ranged widely from 100.3 to 44.7% and PAm correlated with %VO2max weakly (r = -0.53, p less than 0.05). But there was a significant inverse relationship between Qp/Qs and %VO2max(r = -0.85, p less than 0.01). In 16 patients without PH, maximal O2-pulse during exercise was also inversely correlated with Qp/Qs (r = -0.76, p less than 0.01). The relation between PAm and %VO2max suggests that afterload on the right ventricle may be an important determinant of exercise capacity in patients with PH. And the relation between Qp/Qs and %VO2max or Qp/Qs and % maximal O2-pulse suggests that Qp/Qs may also be a very important determinant factor of exercise capacity in patients without PH.

Adult↗
PubMed1992

Phosphatidic acid with medium-length fatty acyl chains synergistically stimulates phospholipase C with Ca2+ in rabbit platelets.

The mode of phospholipase C activation in platelet cells induced by didecanoyl (C10)-phosphatidic acid (PA) was investigated with washed rabbit platelets. The C10-PA dose-dependently induced aggregation and serotonin secretion, as well as increases in cytoplasmic free Ca2+ concentration and 1,2-diacylglycerol formation. None of these responses was evoked unless Ca2+ had been added to the platelet suspension. Furthermore, under the conditions of various intracellular Ca2+ concentrations which were set by treatment of the cells with ionomycin and Ca2+, C10-PA promoted 1,2-diacylglycerol formation only at the Ca2+ concentration of 300 nM or higher, whereas thrombin induced the formation even at 100 nM Ca2+. These results suggest that PA activates platelet phospholipase C in cooperation with Ca2+ and contributes to platelet activation through such an effect.

Animals↗
PubMed1991

Lipid peroxide makes rabbit platelet hyperaggregable to agonists through phospholipase A2 activation.

Treatment of rabbit platelets with tert-butyl hydroperoxide and Fe2+ caused increasing arachidonic acid release, lysophosphatidylcholine formation, and aggregation with increasing concentrations of Fe2+. A combination of tert-butyl hydroperoxide and a low concentration of Fe2+, which by itself causes slight or no such activation, elicited synergistic release of arachidonic acid and aggregation under stimulation with a suboptimal concentration of collagen or arachidonic acid as an agonist. These responses were inhibited by pretreatment of the platelets with vitamin E or mepacrine in a concentration-dependent manner, but not by uric acid. The arachidonic acid release was dependent on the presence of Ca2+ in the medium. Synergistic formation of lysophosphatidylcholine, but not diacylglycerol, was also observed under this condition. The aggregation was also inhibited by indomethacin, a cyclooxygenase inhibitor. Cyclooxygenase activity was not affected by the oxidative treatment. These results suggest that lipid peroxide formed in membranes causes phospholipase A2 to become hypersusceptible to the agonist used, making the platelets hyperaggregable.

Animals↗
PubMed1991

Suppressive effect of biscoclaurine alkaloids on agonist-induced activation of phospholipase A2 in rabbit platelets.

The effect of biscoclaurine (bisbenzylisoquinoline) alkaloids on phospholipase A2 and C activation in signal transduction system of rabbit platelet was studied. Isotetrandrine, cepharanthine and berbamine inhibited the aggregation induced by collagen but not by other stimuli such as thrombin and arachidonic acid, while tetrandrine equally inhibited the aggregation by any of these agonists. All these four alkaloids suppressed arachidonic acid liberation in response to collagen or thrombin, but not diacylglycerol formation and increase in cytoplasmic Ca2+ concentration in response to thrombin or arachidonic acid. In saponin-permeabilized platelets, they also suppressed arachidonic acid liberation induced by an addition of both GTP gamma S and Ca2+, whereas the liberation induced by an addition of Ca2+ alone was not prevented by them. These data suggest that isotetrandrine, cepharanthine and berbamine have a rather specific potency to suppress the phospholipase A2 activation by a mechanism other than direct inhibition of the enzyme or interference with the ligand-receptor interaction. They seem, at least in part, to exert the effect on the GTP-binding protein-phospholipase A2 complex in the platelet signal transduction system. In contrast, tetrandrine appears to inhibit a step following an increase in cytosolic free Ca2+ concentration in the agonist-induced signal transduction system, in addition to suppressing the phospholipase A2 activation.

Alkaloids↗
PubMed1991

Insemination of bile duct carcinoma to the liver after insertion of percutaneous biliary endoprosthesis.

Percutaneous transhepatic biliary drainage is widely used to relieve bile duct obstruction which can be caused by bile duct or pancreas carcinomas. Although the incidence is low, insemination of carcinoma along the transhepatic catheter tract is considered to be a serious complication of percutaneous transhepatic biliary drainage. The authors present a case of intrahepatic insemination of bile duct carcinoma along the catheter that subsequently underwent a curative resection consisting of pancreaticoduodenectomy and right hepatic lobectomy. It is suggested that a percutaneous biliary endoprosthesis through the tumor should be avoided in patients in whom a possible curative resection can be considered. External biliary drainage should only be performed in order to minimize the manipulation of the tumor in such patients.

Adenocarcinoma↗
PubMed1991

Mutagenic activities of tryptophan metabolites before and after nitrite treatment.

The mutagenic activities of 16 kinds of tryptophan metabolites, before and after nitrite treatment, were examined in the Ames test. None of the compounds showed mutagenic activity before nitrite treatment. After nitrite treatment under acidic conditions, 11 compounds showed mutagenic activity towards Salmonella typhimurium TA100 strain in the absence of a metabolic activation system. Tryptophan induced 1000 revertant colonies/mumol, while 5-hydroxyindole, 5-hydroxytryptamine and 3-hydroxykynurenine, all containing a hydroxy group in the molecule, induced 11,000, 5200 and 2700 revertant colonies/mumol, respectively. These results indicate that the introduction by nitrite treatment of a hydroxy group into the indole or benzene ring of tryptophan-related compounds increases their mutagenic activity.

Biotransformation↗
PubMed1991

Effect of vasoactive intestinal peptide on the release of growth hormone in perifused pituitary and hypothalamus of the goat.

The effect of vasoactive intestinal peptide (VIP) on the release of growth hormone (GH) from the adenohypophysis of the goat was studied in vitro using the perifusion system. Two perifusion systems were employed to differentiate potential direct effects of VIP on the pituitary from indirect effects mediated through the hypothalamus. The first perifusion system used single chambers housing only pituitary fragments. The second system used two chambers in tandem, one containing hypothalamus and the second the pituitary fragments, the flow passing through the hypothalamic chamber first. VIP (10(-6), 10(-7), 10(-8)M) stimulated significant GH release in both perifusion systems (P less than 0.05, P less than 0.01) in a concentration related fashion. The quantity of GH release induced by the 10(-9)M and 10(-10)M VIP groups were not significant. Further, the GH released from the system that perifused the pituitary alone (10(-8)M VIP) was significantly higher than that containing both the hypothalamus and the pituitary fragments (P less than 0.05). The relative lower GH secretory response to the same dose of VIP applied to the hypothalamus-pituitary suggests that the perifused caprine hypothalamus may release an inhibitory factor, such as somatostatin in vitro. These results suggest that VIP stimulates GH release by acting directly on the adenohypophysis of the goat.

Animals↗
PubMed1991

Posttranscriptional modification of tRNA in thermophilic archaea (Archaebacteria).

Nucleoside modification has been studied in unfractionated tRNA from 11 thermophilic archaea (archaebacteria), including phylogenetically diverse representatives of thermophilic methanogens and sulfur-metabolizing hyperthermophiles which grow optimally in the temperature range of 56 (Thermoplasma acidophilum) to 105 degrees C (Pyrodictium occultum), and for comparison from the most thermophilic bacterium (eubacterium) known, Thermotoga maritima (80 degrees C). Nine nucleosides are found to be unique to the archaea, six of which are structurally novel in being modified both in the base and by methylation in ribose and occur primarily in tRNA from the extreme thermophiles in the Crenarchaeota of the archaeal phylogenetic tree. 2-Thiothymine occurs in tRNA from Thermococcus sp., and constitutes the only known occurrence of the thymine moiety in archaeal RNA, in contrast to its near-ubiquitous presence in tRNA from bacteria and eukarya. A total of 33 modified nucleosides are rigorously characterized in archaeal tRNA in the present study, demonstrating that the structural range of posttranscriptional modifications in archaeal tRNA is more extensive than previously known. From a phylogenetic standpoint, certain tRNA modifications occur in the archaea which are otherwise unique to either the bacterial or eukaryal domain, although the overall patterns of modification are more typical of eukaryotes than bacteria.

Adenosine↗
PubMed1991

Magnetic resonance imaging of fat embolism syndrome--case report.

The authors describe a case of fat embolism syndrome in a 20-year-old male. Magnetic resonance (MR) imaging demonstrated multiple small cerebral infarcts suggesting this is the cause of the associated cerebral dysfunction. He underwent chemotherapy and hyperbaric oxygen therapy and recovered rapidly. MR imaging can provide prognostic indications in fat embolism syndrome.

Accidents, Traffic↗
PubMed1991

Preoperative prediction of nodal state in gastric cancer by nuclear DNA content.

To see if there was an association between the number of lymph node metastases and the macroscopic findings of the tumour (such as size, location, and gross appearance), the nuclear DNA content was cytophotometrically analysed in biopsy specimens taken at preoperative endoscopy from 84 cases of gastric cancer. The DNA ploidy patterns were classified into type D, type A1, and type A2, according to the stem lines and the degree of scatter of the cells. Lymph nodes were positive in 2 of 20 (10%) in type D and 10 of 30 (33%) in type A1; these were both significantly lower than that in type A2 (24 of 34, 71%). Knowing the degree of nodes metastases or the microscopic lymphatic spread before the operation is almost impossible at present; the nuclear DNA content is closely associated with metastatic content of the nodes, so the cytophotometric determination of the DNA ploidy patterns from biopsy specimens may be useful in predicting the nodal state.

Aged↗
PubMed1991

Relation between functions and conformational characteristics of modified nucleosides found in tRNAs.

Conformational characteristics of N4-acetyl-2'-O-methylcytidine (ac4Cm), 5-methyl-2'-O-methylcytidine (m5Cm) and N2-dimethyl-2'-O-methylguanosine (m2(2)Gm) found in tRNAs from extremely thermophilic archaebacteria were analyzed by proton NMR spectroscopy. The 2'-O-methylation of ac4C, m5C and m2(2)G was found to stabilize the C3'-endo form and therefore cause "conformational rigidity". In particular, the ac4Cm was found to be extremely rigid due to additive effects of the N4-acetylation and 2'-O-methylation. Therefore, tRNAs from the extremely thermophilic archaebacteria use the base modifications in combination with the 2'-O-methylation, resulting in stabilization of the A-type conformation at specific positions in the tRNAs even at very high temperatures. In contrast, mesophile tRNAs use for a given site only one of these ribose and base modifications each of which is effective enough by itself at ordinary temperatures. These findings are consistent with our previous findings that roles of a variety of post-transcriptional modifications are to regulate the conformational rigidity/flexibility which is essential for the tRNA functions.

Archaea↗
PubMed1991

[DNA ploidy in submucosal cancer of the stomach and its relationship to lymph node metastasis].

The relationship between DNA ploidy and lymph node metastasis was determined in 40 cases of gastric cancer confined to the submucosa (with lymph node metastasis 20 cases and without 20 cases). The DNA ploidy patterns were classified as follows: Type D, Type A1 and Type A2. Of the 20 cases with lymph node metastasis, 1 was Type D, 7 were Type A1 and 12 were Type A2. The likelihood of lymph node metastasis was 12.5% (1/8) for Type D, 43.8% (7/16) for Type A1 and 75.0% (12/16) for Type A2. It is concluded that although gastric cancer confined to the submucosa is classified as early one, analysis of DNA content places such tumors with lymph node metastasis into the advanced cancer category.

DNA, Neoplasm↗
PubMed1990

Tracheal reconstruction by esophageal interposition: an experimental study.

The purpose of this study was to assess the possibility of reconstructing a circumferential tracheal defect with autogenous esophagus. In 6 mongrel dogs, a circumferential defect involving seven rings of the cervical trachea was reconstructed by interposing pedicled esophagus. A silicone T tube was used as a stent. The vertical limb of the T tube (usually referred to as the horizontal limb when used in humans) was cut shorter after the cervical wound had healed well, and it eventually was buried subcutaneously. Two dogs died 36 days after operation, and 1 died 28 weeks after operation. In no dog was the cause of death related to the operation or to a respiratory tract complication. Two dogs were put to death 4 weeks and 32 weeks after operation. They were well until then, and all the anastomoses between the trachea and the esophagus had healed fully without formation of granulation tissue. One dog is alive and well 14 months after operation. The vertical limb of the T tube retracted into the subcutaneous space, and there is no open cervical wound. Esophageal interposition might be a feasible technique for tracheal replacement in select groups of patients.

Anastomosis, Surgical↗
PubMed1990

Effects of VIP and GRF on the release of growth hormone in perifused bovine adenohypophysis.

The effects of vasoactive intestinal polypeptide (VIP) and growth hormone releasing factor (GRF:hpGRF(1-29)-NH2) on the release of growth hormone (GH) from anterior pituitaries from cows were examined by using an in vitro superfusion system. The pituitaries were excised randomly from cycling cows, dissected to obtain medial portions, and minced to obtain cubes with approximate dimensions of 1.5mm on a side. For each perifusion setup, 5 pieces of pituitary tissues were chambered and flushed with modified KRB solution saturated with 95% O2-5% CO2 at 38C. Perifusion with media containing 10(-6) and 10(-7)M VIP for 30 min induced a significant release of GH during the treatments (P less than 0.05). VIP (10(-8)M) increased GH levels significantly (P less than 0.05), but to a minor degree. Perfusion with the media containing 10(-6), 10(-7) and 10(-8)M GRF for 30 min markedly increased the GH concentration and the effects continued up to 90 min after termination of the perifusion of the peptide (P less than 0.05, P less than 0.01). The GH releasing effects of GRF could be seen at doses as low as 10(-11)M GRF (P less than 0.05, P less than 0.01). These findings indicate that the GH releasing effect of VIP is less potent than that of GRF in cows.

Animals↗
PubMed1990

Clinical study of urinary excretion of Ga-67.

Ga-67 urinary excretion was examined in 59 patients. The 72-hour urinary excretion rate ranged from 4.3 to 67.8% of the injected dose. Within the first 24 hours, 60.9% of the 72-hour urinary excretion was excreted. There was no significant difference in the Ga-67 urinary excretion rate between males and females, nor between the Ga-67 positive and negative cases. A significant negative correlation was found between the 72-hour Ga-67 urinary excretion rate and the unsaturated iron binding capacity. Notably, four patients with hyperferremia, which was considered secondary to leukemia and/or chemotherapy or liver cirrhosis, excreted more than 46.8% of Ga-67 within 72 hours. A significant negative correlation was also found between the 72-hour Ga-67 urinary excretion rate and age. Urinary excretion of Ga-67 may be related to the glomerular filtration rate, which decreases with age.

Adolescent↗