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Biomedical subjects

S Takehara

Publications and source records attributed to S Takehara.

At least 37 records · Page 2Linked to original sources
PubMed1994

Case of perforated peptic ulcer treated conservatively.

We report a patient fifty-one-year old man with peptic ulcer which was treated conservatively. His chief complaints were epigastric discomfort and tarry stool. On admission, no fever was noted, the abdomen was flat and extremely hard, tenderness was noted, and peritoneal rebound was absent. Laboratory data on admission were all normal except for a slightly elevated CRP level. Oral intake was suspended and the patient received infusion. The chest X-ray film on the following day revealed free air, and the diagnosis of perforation of the upper digestive tract was confirmed; however, the symptoms and signs of peritonitis diminished. Therefore, he was treated conservatively. This case suggests that the conventional indications for emergency surgery for perforated peptic ulcer should be re-evaluated.

Anti-Ulcer Agents↗
PubMed1994

Intercostal muscle pedicle flap for prophylaxis against bronchopleural fistula after pulmonary resection.

Between April 1982 and March 1994, we did 384 pulmonary resections for lung cancer. Until March 1991, we did 249 pulmonary resections in which none of the bronchial stumps were reinforced; nine patients developed bronchopleural fistula (incidence, 4%). After April 1991, bronchial stumps of 135 patients were reinforced by an intercostal muscle pedicle flap for prophylaxis against bronchopleural fistula. Only one patient developed it (incidence, 1%). In these two periods, the proportion of patients in stage IIIa or more advanced stages increased from 24% to 41%, resulting in more extensive operations and more patients being given chemo-radiation therapy in the perioperative period. These are risk factors for bronchopleural fistula, but the incidence of the fistula decreased. These results suggest that reinforcement of the bronchial stump with an intercostal pedicle flap is useful for prophylaxis against developing bronchopleural fistula.

Adult↗
PubMed1994

[Clinical evaluation of changes in serum zinc and copper concentrations around pulmonary operation].

Serum zinc and copper were measured in 47 patients undergoing pulmonary operation. They were divided into two groups according to the extent of the operation. Group A consisted of 32 patients with lung cancer, in whom lobectomy with lymphadenectomy was performed through the postero-lateral thoracotomy. Group B consisted of 15 patients with benign pulmonary lesion or metastatic pulmonary tumor, in whom wedge resection was performed through the axillary thoracotomy. In Group A, the serum zinc concentration most decreased 6 hours after surgery. It returned to normal level in 5-7 days and to the preoperative level within 14 days. In Group B, the maximal fall in serum zinc was at 3 hours after operation. Restoration to normal level was at 2nd postoperative day and to the preoperative level was at 5th postoperative day. The differences in serum zinc between two groups were significant (p < 0.05) from just after operation to 4th postoperative day. The degree of maximal decrease in serum zinc in Group A was more than that in Group B. Blood loss, operation time and pulmonary function did not influenced the change of serum zinc concentration in our series. These results show that degree and duration of reduction in serum zinc depends on the surgical trauma. On the other hand, no significant difference in serum copper levels was observed between two groups. The influence of pre- and post-operative pneumonia on serum zinc concentrations were followed in 3 patients. Fall and rise in serum zinc levels coincided with manifestation of and recovery from pneumonia.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

[Case of traumatic diaphragmatic hernia whose diagnosis was delayed by mechanical ventilation].

A 39-year-old male was admitted to our ICU following traffic accident. The major symptoms were short breathness and unconsciousness due to cerebral hemorrhage. He was treated by mechanical ventilation which delayed the diagnosis of traumatic diaphragmatic hernia. On the 6 day after traffic accident we performed thoracotomy and repaired ruptured diaphragm. It was difficult to diagnose the patient as diaphragmatic hernia who was treated by mechanical ventilation.

Accidents, Traffic↗
PubMed1993

Compression of the left brachiocephalic vein: cause of high signal intensity of the left sigmoid sinus and internal jugular vein on MR images.

To study the asymmetry in signal intensity of the sigmoid sinuses, internal jugular veins (IJVs), or both sets of structures on magnetic resonance (MR) images, the authors reviewed 226 serial sets of routine MR imaging studies. Cerebral digital subtraction angiography was performed in 20 patients with a markedly higher intensity and/or enhancement on the left; 15 of them also underwent venography. With every sequence, the left sigmoid sinus, IJV, or both were higher in signal intensity significantly more often than the right (range, P = .0001 to .0129). Angiography revealed hemostasis in the left IJV in 16 patients that disappeared during full inspiration in 14. In 13, venography revealed that the left brachiocephalic vein was compressed to occlusion between the aortic arch and the sternum during tidal volume ventilation. The occlusion disappeared at full inspiration, when the distance between the aortic arch and the sternum increased. This hemostasis could be the major cause of the frequent increased signal intensity of the left sigmoid sinus and IJV on MR images.

Adolescent↗
PubMed1993

New fluorinated dopamine D2 ligands with benzofuran skeleton. The synthesis and in vitro evaluation.

New fluorinated ligands with N-[(1-ethyl-2-pyrrolidinyl)methyl]-2,3-dihydrobenzofuran-7-carboxamide skeleton, which are useful as a prototype to develop 18F labelled in vivo radiotracer for positron emission tomography (PET), were synthesized, and their binding affinities for the dopamine D2 receptors were investigated. Fluorine atom was introduced at C-4 of the pyrrolidine ring (10) or at ethyl substituent at C-5 of the dihydrobenzofuran moiety (20). The in vitro IC50 values of these ligands for the dopamine D2 receptors which were determined by their ability to inhibit the binding of [3H]spiperone binding in rat striatal membrane were 17 and 36 nM, respectively. Thus, the fluorinated compounds 10 and 20 may be possible candidates for further in vivo investigation.

Animals↗
PubMed1992

[High affinity binding of Y-25130 for serotonin 3 receptor].

The binding of Y-25130 on serotonin 3 (5-HT3) receptors was evaluated by examining its effect on 3H-BRL 43694 (3H-granisetron) binding to rat cerebral cortex membranes in comparison with those of granisetron, ondansetron and metoclopramide. Y-25130, granisetron, ondansetron, metoclopramide, 5-HT and 2-methyl-5-HT displaced the specific binding of 3H-granisetron to the synaptosomal membranes in a concentration-dependent manner. The rank order of potency for inhibition of 3H-granisetron binding by the test compounds was Y-25130 not equal to granisetron greater than ondansetron much greater than 2-methyl-5-HT not equal to 5-HT not equal to metoclopramide. To determine the manner of interaction between Y-25130 and 5-HT3 receptors, Scatchard analysis of 3H-granisetron specific binding to the membranes of the cerebral cortex in the absence or presence of various concentrations of Y-25130 was performed. It was indicated that Y-25130 exerted a typical competitive-type inhibition of 3H-granisetron binding. The present study indicates that Y-25130 binds competitively to 5-HT3 receptors with high affinity.

Animals↗
PubMed1992

Antagonistic activity of Y-25130 on 5-HT3 receptors.

This paper describes the 5-hydroxytryptamine3 (5-HT3) receptor antagonism of Y-25130 ((+-)-N-(1-azabicyclo[2.2.2]oct-3-yl)-6-chloro-4-methyl-3-oxo-3,4-dih yd ro- 2H-1,4-benzoxazine-8-carboxamide monohydrochloride) in the rat cerebral cortex, isolated rabbit heart and isolated guinea pig ileum. In an in vitro binding assay, Y-25130 inhibited the specific binding of [3H]quipazine to 5-HT3 receptors at the synaptic membranes of the rat cerebral cortex with a Ki value of 2.9 nM, the same as that of ondansetron. Metoclopramide, 5-HT and 2-methyl-5-HT also showed an inhibitory effect, but their affinities for 5-HT3 receptors were lower than that of Y-25130. Y-25130 showed low affinity for histamine H1 receptors (IC50 = 4.4 microM) but it could not reveal any affinities for the other receptors (5-HT1A, 5-HT2, dopamine D1, dopamine D2, alpha 1-adrenoceptor, alpha 2-adrenoceptor, muscarine and benzodiazepine) even at a 10 microM concentration. In the isolated rabbit heart, Y-25130 antagonized the indirect sympathomimetic responses to 5-HT (pA2 value = 10.06) and this effect was more potent than that of metoclopramide. In the isolated longitudinal smooth muscle of the guinea pig ileum, concentration-contraction effect curves for 5-HT were biphasic in the presence of ketanserin. Y-25130 shifted to the right only in the second phase of concentration-effect curves for 5-HT (pA2 value = 7.04) and its activity was more potent than that of metoclopramide. These results indicate that Y-25130 is a potent and selective 5-HT3 receptor antagonist.

Acetylcholine↗
PubMed1992

Multilevel anterior cervical fusion using skull bone grafts. Case report.

The successful use of autogenous skull bone grafts for a C3-7 anterior cervical fusion is reported and compared with results using other bone grafts. A 51-year-old man with C4-7 anterior cord compression due to spurs and ossified posterior longitudinal ligaments developed progressive tetraparesis following a minor head injury. He underwent anterior decompression and fusion. On two occasions an iliac graft had failed; however, a graft of autogenous skull bone was successful. The skull bone was found superior to bone from other sites, such as the iliac crest, rib, tibia, and fibula, showing sufficient strength and less morbidity. The skull may be a better source of graft material for multilevel anterior cervical fusion, which requires long and strong grafts.

Cervical Vertebrae↗
PubMed1991

Antidopaminergic effects of the stereoisomers of N-[(1-alkyl-2- pyrrolidinyl)methyl]-5-sulfamoylbenzamides and -2,3-dihydrobenzofuran-7-carboxamides.

The stereoisomers of some N-[(1-alkyl-2-pyrrolidinyl)methyl]-5- sulfaoylbenzamides (3-8) and -2,3-dihydrobenzofuran-7-carboxamides (9-18) were prepared to compare their dopamine D2 receptor binding affinities (in vitro) and inhibitory effects on apomorphine-induced hyperactivity (in vivo). In the 1-ethyl substituted compounds of the two series, the stereoisomers with S absolute configuration at the 2-position of the pyrrolidine moiety (S enantiomer 3 and 2S diastereomers 9 and 10) were more potent in both of the above activities than those with R absolute configuration (R enantiomer 4 and 2R diastereomers 11 and 12, respectively), whereas the R enantiomer (8) was more potent than the S enantiomer (7) in the 1-n-hexyl-substituted-benzamides and the 2R diastereomers (15, 16, and 18) were more potent than the 2S diastereomers (13, 14, and 17) in the 1-n-butyl- and 1-n-hexyl-2,3-dihydrobenzofuran-7-carboxamides. It was found that the stereospecificity of the compound activities altered from the S configuration to the R configuration as the 1-alkyl side chain became longer in the two series. How these stereoisomers meet the configurational requirements to interact with the dopamine D2 receptors is also discussed.

Animals↗
PubMed1991

Studies on the synthesis of condensed pyridazine derivatives. IV. Synthesis and anxiolytic activity of 2-aryl-5,6-dihydro-(1)benzothiepino[5,4- c]pyridazin-3(2H)-ones and related compound.

A series of 2-aryl-5,6-dihydro-(1)benzothiepino[5,4-c]pyridazin-3(2H)- ones and related compounds were synthesized and evaluated for their ability to displace 3H-diazepam from rat brain membranes in vitro, and to prevent bicuculline induced convulsions in mice in vivo. Compounds with a 4'-methoxyphenyl (36) or 4'-chlorophenyl group (37, 39--42) as 2-aryl substituents showed prominent activities in both the in vitro and in vivo tests. Among them, 2-(4'-chlorophenyl)-5,6-dihydro- (37) and 2-(4'-chlorophenyl)-5,6-dihydro-10-fluoro-(1)benzothiepino[5,4-c]+ ++pyridazin- 3(2H)-one 7-oxides (41) showed activity twice as potent as diazepam in an anticonflict test (Vogel type, rats) while exhibiting less muscle relaxation (rotarod test, mice) and augmentation of gamma-aminobutyric acid-induced chloride current (Icl) in isolated frog sensory neurones than diazepam. Compound 37 (Y-23684) was selected from this series as a candidate for further development. The structure-activity relationships are discussed.

Animals↗
PubMed1991

New fluorine-substituted analogue of eticlopride with high affinity toward dopamine D2 receptors.

Aiming at the development of positron-emitting ligands with specific and high affinity toward dopamine D2 receptors in the central nervous system, we synthesized a new fluorinated eticlopride derivative. A fluorine atom was introduced at the C-4 position of the pyrrolidine ring of eticlopride, a dopamine D2 antagonist of the benzamide series. The in vitro binding affinity of this ligand toward the D2 receptor was found to be as potent as eticlopride, suggesting that the corresponding 18F-labelled compound may be useful as an in vivo radioligand for positron emission tomography.

Animals↗
PubMed1990

Pharmacological actions of Y-24180, a new specific antagonist of platelet activating factor (PAF): II. Interactions with PAF and benzodiazepine receptors.

The inhibitory effect of Y-24180, 4-(2-chlorophenyl)-2-[2-(4-isobutylphenyl)ethyl]-6,9-dimethyl-6H-t hieno [3,2-f][1,2,4]triazolo [4,3-a][1,4]diazepine, on platelet activating factor (PAF)-induced platelet aggregation and the specific binding of 3H-PAF to platelets was compared with other thienodiazepine derivatives, WEB 2086 and etizolam. Y-24180 inhibited PAF-induced rabbit platelet aggregation in vitro (IC50 3.84 nM), but had little effect on adenosine diphosphate- or arachidonic acid-induced aggregation. WEB 2086 and etizolam also showed an inhibitory effect of PAF-induced aggregation (IC50 values are 456 and 6730 nM, respectively). In PAF-induced human platelet aggregation, Y-24180 (IC50 0.84 nM) was more potent than WEB 2086 (IC50 4.21 nM) and etizolam (IC50 998 nM). Y-24180, WEB 2086 and etizolam displaced 3H-PAF binding from the washed-platelets of rabbits with an IC50 value of 3.50, 9.35 and 29.5 nM, respectively. In rabbits, pretreatment with Y-24180 and WEB 2086 antagonized PAF-induced platelet aggregation dose-dependently. The significant inhibitory effect of Y-24180 (1 mg/kg, p.o.) lasted 72 hr after a single dose oral administration. WEB 2086 (10 mg/kg, p.o.) also antagonized the ex vivo response induced by PAF 1 hr after administration, but no significant effect was observed 3 hr after administration. Y-24180 displaced 3H-diazepam binding from the synaptosomal membranes of rat cerebral cortex with a Ki value of 3.68 microM. The affinity of Y-24180 for benzodiazepine(BZP) receptors was lower than those of WEB 2086 and etizolam and was about 1000 times lower than that for PAF receptors in platelets.

Animals↗
PubMed1990

[Studies on the synthesis of condensed pyridazine derivatives. III. Synthesis and benzodiazepine receptor binding studies of condensed triazolopyridazine derivatives].

A series of 6H-(1)benzothiopyrano[3,4-e][1,2,4]triazolo[4,3- b]pyridazines and 6,7-dihydro-(1)benzothiepino[4,5- e][1,2,4]triazolo [4,3-b]pyridazines were prepared and tested for their ability to displace [3H] diazepam from rat brain membranes. An approximately planar shape of these molecules was essential for high affinity to the benzodiazepine receptor. Among them, 11-aryl compounds in the latter series were found to have high affinity to the benzodiazepine receptor. 11-Phenyl- and 11-thienyl- 6,7-dihydro-(1)benzothiepino[4,5-e][1,2,4]triazolo[4,3- b]pyridazine (3b-5 and 3b-11 respectively) showed the potent affinity comparable to that of diazepam. The structure-activity relationships are also discussed.

Animals↗
PubMed1990

[Studies on the synthesis of condensed pyridazine derivatives. I. Synthesis and benzodiazepine receptor binding studies of 2-substituted-4,4a,5,6-tetrahydrobenzo[h]cinnolin-3(2H)-ones and related compounds].

A series of 2-substituted-4,4a,5,6-tetrahydrobenzo[h]cinnolin-3(2H)-ones and related compounds were synthesized and tested for their ability to displace [3H]diazepam from rat brain membranes. Among them, compounds bearing 4-methoxyphenyl, 4-chlorophenyl, or 4-methylphenyl group at the position-2 were found to have high affinity to the benzodiazepine receptor. 2-(4-Methoxyphenyl)-9-methyl- and 2-(4-methoxyphenyl)-9-methoxy-4,4a,5,6-tetrahydrobenzo[h]cinnolin- 3(2H)-ones (8b-14 and 8b-15, respectively) showed a potent affinity comparable to that of diazepam. These results suggest that a topographical planarity or pseudoplanarity of these molecules is essential for high affinity to the benzodiazepine receptor. The structure-activity relationships are discussed.

Animals↗
PubMed1990

[Studies on the synthesis of condensed pyridazine derivatives. II. Synthesis and anxiolytic activities of 2-aryl-4,4a,5,6-tetrahydropyridazino[4,3-c]quinolin-3(2H)-ones, 2-aryl-4a,5-dihydro-2H-(1)benzothiopyrano[4,3-c]pyridazin-3(4H)-ones, and related compounds].

A series of 2-aryl-4,4a,5,6-tetrahydropyridazino[4,3-c]quinolin-3(2H)- ones, 2-aryl-4a,5-dihydro-2H-(1)benzothiopyrano[4,3-c]pyridazin-3( 4H)-ones, and related compounds were synthesized and tested for their ability to displace [3H]diazepam from rat brain membranes in vitro, and to prevent bicuculline-induced convulsions in mice in vivo. Among them, 2-(4-chlorophenyl)-4a,5-dihydro-2H-(1)benzothiopyrano[4,3-c]pyr idazin-3(4H)- one (16b) showed remarkable activities both in vitro (Ki 48 nM) and in vivo (ED50 12.4 mg/kg, p.o.). The trans sulfoxide (19a) of 16b exhibited anxioselective pharmacological activities. Compound 19a was equipotent with diazepam in the anticonflict assay (Vogel type, rat, MED 10 mg/kg, p.o.) while exhibiting reduced muscle relaxation (rotarod test) and narcotic potentiation. The structure-activity relationships are discussed.

Animals↗
PubMed1989

Effects of thioamide substitution for the enkephalin conformation. Crystal structure of Boc-Tyr-Gly-Gly-Phe psi [CSNH]Leu-OBzl.

The crystals of Boc-Tyr-Gly-Gly-Phe psi[CSNH]Leu-OBzl monohydrate (C40H51N5O8S.H2O), a monothionated Leu-enkephalin analogue, were obtained with space group P2(1), a = 12.616(3), b = 9.347(2), c = 18.548(5) A, beta = 96.31(4) degrees. The structure was elucidated by X-ray diffraction analysis, and refined to the R value of 0.091 for the observed 3294 reflections. Two antiparallel molecules related by a pseudo twofold symmetry were stabilized to each other by four intermolecular hydrogen bonds. The molecular conformation was bent at the Phe residue, and the extended moiety of the Tyr-Gly-Gly fragment was almost perpendicular to that of the Phe-Leu residues. Consequently the molecule, as a whole, formed an L-shape conformation with a slightly left-handed helicity.

Amides↗