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T Yasui

Publications and source records attributed to T Yasui.

At least 19 recordsLinked to original sources
PubMed1992

Reversed-phase high-performance liquid chromatography of several metal-8-quinolinethiol complexes.

The reversed-phase high-performance liquid chromatography of 8-quinolinethiol (Hqt) complexes of Fe, Co, Ni, Cu, Zn, Hg and Pb on an octadecyl-bonded silica gel stationary phase was examined. The Pb complex dissociated in the column. The retention and separation of other complexes depended on the composition of the mobile phase. EDTA as an additive displaced the Zn complex and eliminated its peak. All the other metal complexes and also Hqt and its disulphide were separated in 23 min by using methanol-water (82:18, v/v) as the mobile phase. The complexes formed by the reaction of Co(II) and Hqt gave three peaks, which were assigned as fac(S)-CoIII(qt)3, mer(S)-CoIII(qt)3 and CoII(qt)2, respectively. This method is applicable to the simultaneous determination of Fe, Co, Ni, Cu and Hg.

Chromatography, High Pressure Liquid↗
PubMed1992

Maintenance of androgen-, glucocorticoid- or estrogen-responsive growth in shionogi carcinoma 115 subline sustained in castrated mice with high dose of estrogen for 30 generations (3 years).

Shionogi carcinoma 115 (SC115), an androgen-dependent mouse mammary tumor, rapidly loses its androgen responsiveness after androgen withdrawal. The growth of this tumor can also be stimulated by high doses of estrogen or glucocorticoid. In the present study, the maintenance of hormone-responsive growth of SC115 tumors with a high dose of estrogen was examined in castrated male mice using an SC115 subline obtained by serial transplantations of SC115 tumors in estrogen-treated castrated mice for 3 years (30 generations) (subline E2). Seed tumors from both SC115 and subline E2 could rapidly grow in castrated mice given daily injections of testosterone propionate (TP), 17 beta-estradiol (E2), or dexamethasone (Dex) (100 micrograms/mouse/day) but not in those given vehicle alone. Although SC115 and subline-E2 tumors grown with TP or Dex showed temporary regression after steroid withdrawal, the tumors grown with E2 did not show such temporary regression. The TP-, E2-, or Dex-induced growth of subline-E2 tumors was almost the same as that of the original SC115 tumors. However, responsiveness to androgen, estrogen or glucocorticoid of both tumors disappeared within one passage in steroid-depleted castrated mice. The present findings demonstrate that the loss of responsiveness to androgen as well as to high doses of estrogen or glucocorticoid of SC115 tumors can be prevented in castrated mice not only with androgen but also with high doses of estrogen.

Animals↗
PubMed1992

Inhibitory effects of hyaluronan on [14C]arachidonic acid release from labeled human synovial fibroblasts.

The effects of hyaluronan (HA) on the release of arachidonic acid (AA) from phospholipids induced by bradykinin in synovial fibroblasts of osteoarthritic patients were examined. HA inhibited [14C]AA release from prelabeled synovial cells stimulated with and without bradykinin 1 hr after incubation with HA and thereafter. The inhibitory effects of HA on [14C]AA release were dependent on the concentration and molecular weight of HA. However, inhibition of [14C]AA release by HA was not merely due to the viscosity of HA. The [14C]AA release induced by calcium-ionophore A23187 was also inhibited by HA with a high molecular weight. In addition, HA did not affect [14C]AA uptake by the cells. Our results suggest that HA with a high molecular weight elicits anti-inflammatory effects, at least in part, by inhibiting AA release in inflamed joints.

Arachidonic Acid↗
PubMed1992

Significance of gadolinium-enhanced magnetic resonance imaging in differentiating spinal cord radiation myelopathy from tumor. Case report.

A young woman with a fourth ventricular ependymoma underwent radiotherapy following tumor excision. Twenty months later she developed a progressive neurological deficit at the C-2 vertebral level. Gadolinium-enhanced magnetic resonance imaging, showed an intramedullary lesion at the C-2 level. Although radiation myelopathy was suspected, tumor recurrence could not be excluded. Re-exploration and histopathology both confirmed a diagnosis of radiation myelopathy. A retrospective review of the case indicated findings favoring radiation myelopathy. The pertinent literature is reviewed and the findings discussed.

Adult↗
PubMed1992

[Ischemic complications following parent artery occlusion with detachable balloons in the treatment of large carotid aneurysms: effectiveness of 99mTc-HMPAO SPECT and importance of postoperative management].

Three patients with large carotid aneurysms were treated by parent artery occlusion with detachable balloons. Of these, 2 had intracavernous carotid artery aneurysms and one had a carotid-ophthalmic aneurysm. All patients underwent a formal balloon occlusion test and tolerated it well. One patient with a carotid-ophthalmic aneurysm, however, developed postoperative ischemic effects. This case was that of a 55 year-old female with right visual disturbance. Her middle cerebral artery flow had been compromised during test occlusion under induced hypotension. Although initially intact after balloon occlusion, she was found to be hemiplegic 24 hours later. She subsequently developed multiple small infarcts which were shown on MRI and which corresponded exactly to the previously demonstrated region of decreased flow during testing. This ischemic complication is possibly due to hypoperfusion, but embolism from the thrombosed aneurysm can not be denied. To prevent these complications, an extracranial-intracranial artery anastomosis prior to parent artery occlusion should be considered if the preoperative 99mTc-HMPAO SPECT shows a compromised cerebral blood flow. In addition to this, postoperative anticoagulant therapy should be given even if test occlusion was well tolerated clinically.

Brain Ischemia↗
PubMed1992

[Antitumor effect of liposome-entrapped carboplatin after intraperitoneal administration in rats].

We examined the distribution in tissue and antitumor effects of freeze-dried liposome-entrapped carboplatin (Lipo-CBDCA) after intraperitoneal administration to rats bearing AH 130 tumors. Liposomes composed of egg lecithin and cholesterol were used as drug carriers. The serum concentration of platinum was decreased for a short time after the intraperitoneal administration of Lipo-CBDCA. After at least 3 hours, the serum concentration of platinum was higher with free CBDCA intraperitoneal or intravenous administration. The antitumor effects of Lipo-CBDCA were determined in rats with peritoneal dissemination due to AH 130 tumors. Intraperitoneal Lipo-CBDCA prolonged the life span of the tumor-bearing rats. No side effects of the chemotherapy were demonstrated in biochemical and histological studies in the liver, kidney, spleen and small intestine. These results indicate that intraperitoneal chemotherapy with Lipo-CBDCA may be more effective than that with free CBDCA managing in peritoneal dissemination, and may be therapeutically useful without toxic side effects.

Animals↗
PubMed1992

[Efficacy of preoperative adjuvant chemotherapy using adriamycin targeting the regional lymph nodes for gastric cancer--lymph node-targeting delivery of adriamycin in rabbits].

Chemotherapy targeting the regional lymph nodes for gastric cancer may be more effective preoperatively than postoperatively since anticancer drugs can be transported to the regional lymph nodes via the lymphatic flow through the stomach. Distribution of Adriamycin (ADR) among the various organs was assessed following its intravenous injection in rabbits. The delivery index of the drug to each organ was assessed by the ratio of the area under the concentration-time curve (AUC) of each organ to the AUC of the regional lymph nodes following the intravenous administration. The delivery index was 0.14 for the stomach, 0.11 for the heart, 0.53 for bone marrow, 0.74 for the spleen, and 0.14 for the liver. These data suggest that preoperative adjuvant chemotherapy by intravenous administration of ADR may be effective in targeting ADR at the regional lymph nodes. Tissue ADR concentrations in the regional lymph nodes were assessed following gastric submucosal administration of ADR in rabbits. The targeting index for the regional lymph nodes was 8.20, measured by the ratio of AUC following a gastric submucosal injection to AUC after the intravenous injection of ADR. This suggests that it may be possible to selectively target chemotherapy to regional lymph nodes by employing a gastric submucosal administration of ADR.

Animals↗
PubMed1992

[Therapeutic occlusion of unilateral vertebral artery for unclippable aneurysms; special reference to postoperative brainstem ischemia].

Seven cases of unclippable vertebral artery aneurysms (3 dissecting, 1 fusiform, 2 saccular and 1 giant) are reported. Five of these had subarachnoid hemorrhage, one showed mass effect and the other was found incidentally. Trapping of the involved portion of the vertebral artery was performed in 4 cases, proximal clip occlusion in 2 and proximal balloon occlusion in 1. There were no operative deaths and no rebleeding, but brainstem ischemia developed in 4 cases, two being transient and two permanent. The ischemic complications were possibly due to; (a) hypoperfusion in the transient cases and (b) thromboenbolism, from the partially thrombosed giant aneurysm or thrombosis of the cul-de-sac vertebral artery, in the permanent ones. Preoperative temporary vertebral artery occlusion with an inflatable balloon or postoperative anticoagulant therapy should be considered in the management protocol.

Aortic Dissection↗
PubMed1992

[Management of elderly patients with aneurysmal subarachnoid hemorrhage].

Clinical features of 61 elderly patients aged over 70 years with ruptured intracranial aneurysms were compared with those of 328 younger patients aged under 70 years. According to a policy of early operation, elderly patients with Hunt and Kosnik's grade I, II and younger patients with grade I, II, III were operated on in the acute stage. In elderly patients with grade III, IV and younger patients with grade IV, the indication for surgery was determined case by case. Surgery was performed on 29 patients (48%) in the elderly group and 277 patients (86%) in the younger group. Our conclusions are as follows: 1. Regarding cases of grade I, II and III of Hunt and Kosnik's classification, the rate of good outcome in the elderly group was similar to that in the younger group, following early surgery and meticulous post-operative care. 2. In the elderly group, no patient in cases of grade IV obtained good surgical outcome. 3. Symptomatic vasospasm was less frequent in elderly patients (18.8%) than in younger cases (37%). 4. Delayed operation was planned for some patients in the elderly group, but none of them underwent surgery because of rerupture of aneurysms and deterioration of general condition.

Adult↗
PubMed1991

Nucleotide sequence of the unique nitrate/nitrite-inducible cytochrome P-450 cDNA from Fusarium oxysporum.

A cDNA clone for the nitrate/nitrite-inducible cytochrome P-450 (P-450) of the fungus Fusarium oxysporum (tentatively termed P-450dNIR) was isolated by an immunoscreening method. Sequence determination revealed a polypeptide of 403 amimo acid residues (Mr = 44,371), which was shown to contain the full-length sequence of the fungal P-450. The amino terminus region of the predicted sequence contained neither the signal-like, hydrophobic domain that is commonly observed in microsomal P-450s nor the tagging prosequence that is essential for localization of mitochondrial P-450s. Further, the sequence exhibited higher homologies against those of soluble bacterial P-450s, in particular P-450s of Streptomyces, rather than those of eukaryotic P-450s including yeast and fungal P-450s. These results are highly indicative that P-450dNIR is the first soluble P-450 derived from eukaryotic organisms. The unique features might be related to the novel function of P-450dNIR, which is involved in a dissimilatory reduction of nitrite by the fungus. P-450dNIR was classified into a new family, P-450LV, and the corresponding gene of the fungus was named CYP55.

Amino Acid Sequence↗
PubMed1991

Traumatic carotid-cavernous sinus fistula associated with an intradural pseudoaneurysm: a case report.

A case of traumatic carotid-cavernous sinus fistula (CCF) associated with an intradural pseudoaneurysm is reported. A 42-year-old man developed traumatic CCF after severe head trauma. Cerebral angiography demonstrated a direct CCF associated with an intradural pseudoaneurysm at the C2 portion. Transarterial balloon embolization of the CCF caused severe subarachnoid hemorrhage. A CCF with an intradural pseudoaneurysm is life-threatening and requires emergency treatment. However, balloon occlusion in such cases is contraindicated because of possible rupture of a pseudoaneurysm. Trapping or a direct surgical approach is the treatment of choice.

Adult↗
PubMed1991

Effects of ginsenoside-Rb2 on adenine nucleotide content of rat hepatic tissue.

In comparison with non-diabetic rats, the tissue ATP content of diabetic rats is lower and the AMP content higher. However, daily intraperitoneal administration of ginsenoside-Rb2 for several days resulted in an increase of tissue ATP content and a decrease of AMP content, characterized by an increase in the adenine nucleotide content, as well as improvement of energy charge. Thus, ginsenoside-Rb2 administration caused a change in the pattern of metabolism, activating the ATP supply system.

Adenine Nucleotides↗
PubMed1991

Computed tomographic evaluation of bleeding sites in primary pontine hemorrhages.

BACKGROUND: With the aim of identifying common bleeding sites and probable parent vessels in "small" primary pontine hemorrhages, we reviewed computerized tomographic scans of 20 patients with hematomas less than 2.5 cm in diameter. SUMMARY OF REPORT: We used scans depicting the upper and lower pons and plotted the centers of the hematomas, assuming them to be a probable source of bleeding. No predilection sites were found on the axial plane. CONCLUSIONS: Both the paramedian and the long and short circumferential arteries were probable sources of hemorrhage in the present series.

Adult↗
PubMed1991

The synthesis of new xylosyloligosaccharides by transxylosylation with Aspergillus niger beta-xylosidase.

The synthesis of xylosyloligosaccharides from beta-(1----4)-xylobiose in the presence of D-mannose by transxylosylation with beta-xylosidase from Aspergillus niger IFO 6662 was studied. At first, the transxylosylation products were separated by charcoal column chromatography in 5% ethanol elution into three peaks, P-1, P-2, and P-3. They were further separated on thin layer chromatography, and their three products, saccharides O-4, O-5, and O-N were purified by preparative paper chromatography. Saccharides O-4 and O-5 were identified as O-beta-D-xylopyranosyl-(1----4)-D- mannopyranose and O-beta-D-xylopyranosyl-(1----6)-D-mannopyranose, respectively, by measurement of the degree of polymerization, specific rotation, acid hydrolysis, and methylation analysis. By 1H-NMR spectroscopy in addition to these analyses, saccharide O-N was identified as O-beta-D-xylopyranosyl-(1----1')-beta-D-xylopyranose, a new nonreducing xylobiose.

Aspergillus niger↗
PubMed1991

[Endoscopic injection of liposomal adriamycin targeting lymph node metastasis of gastric cancer].

Gastric submucosal injection of 5 mg liposomal adriamycin (L-ADM) close to the main gastric cancer tumor was done in 15 patients by endoscopy. This approach was based on the idea that preoperative adjuvant chemotherapy targeting lymph node metastasis in patients with gastric cancer may be effective for prevention of lymph node recurrence. ADM concentrations in the regional lymph nodes were assessed and compared with those in patients who were administered 5 mg of free adriamycin (F-ADM) i.v. preoperatively. ADM concentrations in Group 7 lymph nodes (according to the General Rules for Gastric Cancer Study) were: After 2 days; 7.21 +/- 5.98 micrograms/g (n = 2) in the L-ADM group and 0.59 +/- 0.23 micrograms/g (n = 3) in the F-ADM group. After 4 days; 4.93 +/- 3.93 micrograms/g (n = 2) in the L-ADM group and 0.36 +/- 0.0 micrograms/g (n = 2) in the F-ADM group. After 6 days; 2.08 +/- 0.49 micrograms/g (n = 2) in the L-ADM group and 0.05 +/- 0.05 micrograms/g (n = 3) in the F-ADM group. L-ADM group: those who had L-ADM injected into the side of the lesser curvature of the stomach. F-ADM group: those who had F-ADM administered i.v. These data demonstrate that gastric submucosal injection of L-ADM is well suited for specific delivery to the regional lymph nodes, suggesting that this type of administration may prevent lymph node recurrence of gastric cancer by targeting lymph node metastasis.

Doxorubicin↗
PubMed1991

[Clinical application of chemotherapy via the portal vein with liposome-encapsulated adriamycin in inoperable metastatic liver cancer].

We studied the effects of liposome-entrapped adriamycin (L-ADM) administered via the portal vein and the clinical application of this treatment in the therapy and inhibition of liver metastasis, experimentally and clinically. Liposomes composed of egg phosphatidylcholine (cholesterol 50 mol%) were used as drug carriers. We examined the distribution in tissues and antitumor effect of freeze-dried L-ADM administered via the portal vein to rabbits bearing VX2 tumors. The liver concentration of ADM increased after delivery and cardiac uptake decreased compared with free drug treatment. The life span was prolonged by L-ADM treatment compared with the control group and the free ADM group. This L-ADM administration was confirmed to be safe and revealed a decrease in the heart toxicities compared with free adriamycin. Nineteen cases were studied from Jan. 1986 to May 1991 via the portal vein and the clinical effects were evaluated. From Mar. 1988 to date, 10 cases were treated with L-ADM (20-30 mg every 2 weeks/body) in patients with inoperable cases using subcutaneously implanted reservoir. The median survival was 450 days; 275 days for colon cancer, 492 days for gastric cancer, and 1,052 days for uterine cancer (range: 136-1,152 days), compared with 141 days (range: 52-253 days) in 9 cases of historical control treated with free-ADM via the portal vein. These results suggest that chemotherapy via the portal vein with L-ADM for metastatic liver cancer may increase survival time.

Aged↗