Search PubMed⌕ Search

Biomedical subjects

K Takeuchi

Publications and source records attributed to K Takeuchi.

At least 991 records · Page 55Linked to original sources
PubMed1989

Effects of the duodenal ulcerogens, mepirizole and cysteamine, on gastric motility and emptying in rats.

Mepirizole (60 and 200 mg/kg, s. c.) and cysteamine (100 and 300 mg/kg, s. c.) markedly inhibited gastric motility in fasted rats. The inhibition caused with the low dose (non-ulcerogenic) of each agent reverted to control levels within 6 h. With high doses (ulcerogenic), however, the inhibition persisted for more than 9 h, and returned to control levels 12 h later. Gastric emptying of liquids was significantly delayed with ulcerogenic and non-ulcerogenic doses of the agents. Delayed emptying (gastric contents) persisted for 12 h with ulcerogenic doses, The pathogenetic relevance of this prolonged inhibition of gastric motility and emptying to ulcerogenecity was considered.

Animals↗
PubMed1989

A new model of duodenal ulcers induced in rats by diethyldithiocarbamate, a superoxide dismutase inhibitor.

Repeated administration of diethyldithiocarbamate (DDC: 750 mg/kg, s.c.), a superoxide dismutase (SOD) inhibitor, to fed rats induced ulcers in the duodenum with less lesion in the stomach. DDC not only reduced basal acid output but also impaired duodenal alkaline secretion under both basal and acid-stimulated conditions. The duodenal ulcers induced by DDC were significantly prevented by either allopurinol, SOD or dmPGE2 at the doses which significantly reversed the inhibited alkaline responses caused by DDC. The pathogenesis of DDC-induced duodenal ulcers may involve impairment of duodenal alkaline secretion, probably caused by insufficiency of antioxidant machinery in the mucosa.

16,16-Dimethylprostaglandin E2↗
PubMed1989

Lithium increases rat striatal beta- and gamma-preprotachykinin messenger RNAs.

Previous reports indicate that the antimanic drug, lithium, increases substance P-like immunoreactivity (SP-LI) in the basal ganglia. The aim of this study was to use lithium as a pharmacological tool to further understand the mechanism of this process. We have used solution hybridization-nuclease protection assays to quantitate the specific preprotachykinin (PPT) mRNAs and radioimmunoassays and immunocytochemistry to assess SP-LI levels in the striatum of male Fisher F-344 rats. A regimen of subchronic administration of lithium (4 mEq/kg i.p. for 1, 2, 4 or 6 days) increased SP-LI in a time-dependent fashion. Concurrent administration of a dopamine receptor antagonist, haloperidol (1 mg/kg s.c. for 4 days) with a 4-day lithium regimen partially blocked the lithium-induced increase in SP-LI as well as neurokinin A-like immunoreactivity. An analysis of the abundance of individual PPT mRNAs indicated that lithium increases beta- and gamma-PPT mRNAs in the striatum; coadministration of haloperidol attenuates the lithium-induced increases. These results indicate that lithium affects the tachykinin biosynthetic process by accelerating transcriptional and/or translational processes in striatonigral neurons and that the dopaminergic system appears to be partly involved in this process.

Animals↗
PubMed1989

Difference between the effects of atrial natriuretic peptide and calcium antagonist on cytosolic free calcium in cultured vascular smooth muscle cells.

The effect of atrial natriuretic peptide (ANP) on cytosolic free calcium ([Ca2+]i) was studied in monolayers of cultured vascular smooth muscle (VSM) cells loaded with a fluorescent calcium indicator, fura-2. ANP (atriopeptin III, 10(-8) M) decreased the resting level of [Ca2+]i and sustained rises in [Ca2+]i following peak levels induced by vasoconstrictive hormones (angiotensin II or vasopressin). ANP also decreased a rise in [Ca2+]i induced by high potassium (high K+) depolarization. The initial rise in [Ca2+]i induced by vasopressin was not inhibited by ANP. On the other hand, calcium antagonists (nicardipine or nifedipine) inhibited the high K+-induced rise in [Ca2+]i, whereas there was no effect on rises in [Ca2+]i induced by vasopressin. These results suggest that calcium antagonists inhibit voltage-dependent calcium channels, while ANP can decrease [Ca2+]i presumably through a stimulation of calcium-extrusion active transports in vascular smooth muscle cells.

Animals↗
PubMed1989

[Morphologic findings and biologic behavior in the high grade glioma--a postmortem study of 22 cases].

Morphologic features of the autopsied specimen of 22 cases with supratentorial gliomas treated by surgery, radiation and/or chemotherapy were analysed, and the characteristics of recurrence of gliomas were searched for. The cases consisted of anaplastic 12 astrocytoma and 10 glioblastoma. The results were as follows: 1) Characteristic CT findings before death were regrowth of the tumor mass or the occurrence of a new enhanced lesion in 21 out of 22 cases. The enhanced lesion showing regrowth of the tumor located in the same site as the previous tumor mass in 21 cases. The new enhanced lesion resulting from a trans-or subependymal tumor spread, was seen in the ventricular wall, and these findings were a characteristic feature of the recurrence of gliomas. 2) Modes of extension of the tumor were subdivided into 3 types. One was the expansive or infiltrative type caused by regrowth of the residual tumor. In the second pattern, a spread of tumor cells occurred along the myelinated fiber tracts to the brain stem (60%), or to the contralateral cerebral hemisphere through the corpus callosum (50%). The third mode of tumor propagation was cerebrospinal fluid seeding with intraventricular or subarachnoid tumor regrowth (45%). 3) Characteristic histological findings shown in the original tumor bed were those of increased cellularity with endothelial proliferation, widespread necrosis with occlusion of the blood vessels, occurrence of the gemistocytic astrocytes and large bizarre cells. Thickening of wall of the blood vessels due to effect by radiation was followed by occlusion of the blood vessels. Large necrosis in the tumor tissue was caused by those process and others. Necrotic area was mainly circumscribed and corresponded to the territory of the vessels. One of the specific findings in the morphological changes of the tumor cells was giant cell formation which were monstrous cell, giant cell (12 cases out of 22), and gemistocytic cell (in all cases). These specific cells were supposed to the degenerative changes of the tumor cells exposed while withstanding such adverse conditions as hypoxia, radiation and chemotherapy. 4) Infiltration distant from the primary lesion which were defined only by microscopical examination was demonstrated as both through myelinated fiber tracts in 8 cases and through perivascular spaces in 2 cases. Reinvasion of the tumor cells from the subarachnoid spaces to the brain parenchyma was along the Virchow-Robins spaces of the penetrating blood vessels in the latter cases.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1989

[An autopsy case of adenocarcinoma of the lung with signet ring cells, manifesting with aphasia and hemiparesis due to nonbacterial thrombotic endocarditis].

A 42-year-old male was admitted to Tokyo University Hospital because of confusion, aphasia and right hemiparesis. Cranial computed tomography and cerebral angiography demonstrated cerebral infarction due to occlusion of the left middle cerebral artery, while chest roentgenography disclosed a nodular shadow in the right upper lobe and swelling of right hilar and paratracheal lymph nodes. These findings suggested carcinoma of pulmonary origin and tumor-associated cerebral thrombosis, but a possibility of gastric cancer was raised by the finding of cervical lymph node biopsy which revealed signet ring cells in metastatic adenocarcinoma. He developed disseminated intravascular coagulation syndrome and died on the 83rd hospital day. Autopsy revealed adenocarcinoma of the lung with signet ring cells and non-bacterial thrombotic endocarditis which appeared to be responsible for the cerebral infarction. The relationship between adenocarcinoma of the lung with signet ring cells and non-bacterial thrombotic endocarditis was discussed.

Adenocarcinoma↗
PubMed1989

[Effects of articulating paper on mandibular paths in lateral and protrusive excursions].

Mandibular movements in 7 normal dentulous subjects during lateral and protrusive excursions were studied to investigate the effects of the clinical use of articulating paper on mandibular paths. Mandibular movements with or without the intraoral articulating paper (thickness: 35 microns) were detected as the lower incisal point displacement and were recorded three-dimensionally with the Selspot system. The date displayed on the X-Y chart recorder on the selected plane were analyzed quantitatively. 1. The paths of the mandible differed between the outward (from the intercuspal position) and the return (backward to the intercuspal position) movements. In lateral excursions the return path tended to be antero-inferior to the outward path, whereas in protrusive excursions the former tended to be dextro-inferior to the latter. 2. In lateral excursions the return path tended to be less stable than the outward path. In protrusive excursions no significant difference was found between the two paths. 3. In lateral excursions, 21-34% of the movements performed using the articulating paper deviated from the normal paths made without using the paper, and in the case of protrusive excursions, deviation was found in 21-50%. At or near the intercuspal position, the return path showed a greater deviation than the outward path. Near the edge-to-edge position, however, the relationship between these two path was reversed. 4. It is suggested that, when the articulating paper is used, the directions of the movement should be taken into account and sufficient care should be paid in occlusal adjustment because the range of functional movement may be overestimated.

Dental Occlusion↗
PubMed1989

Inhibitory effect of cicletanine on vascular smooth muscle cell proliferation.

We investigated the effect of cicletanine on vascular smooth muscle cell proliferation. In cultured vascular smooth muscle cells from rat mesenteric artery, cicletanine (10(-5) to 10(-4) M) increased prostacyclin synthesis (measured as 6-keto-PGF1 alpha by radioimmunoassay) dose-dependently. When added to cells in which mitogenesis was activated by 10% fetal bovine serum, cicletanine (3.3 x 10(-5) to 10(-4) M) inhibited [3H] thymidine incorporation up to 31% of the control level. Inhibitory effect of cicletanine on mitogenesis was also confirmed at 48 h by cell counts (control: 18965 +/- 629, cicletanine 10(-4) M: 14840 +/- 430, n = 6). The effect of cicletanine on platelet-derived growth factor (PDGF)-stimulated [3H] thymidine incorporation was not abolished by prostaglandin synthesis inhibition with aspirin, but the prostacyclin analogue OP-41483 (125-1000 ng/ml) inhibited it dose-dependently. Calcium entry blockers, nifedipine (3.3 x 10(-6) M) and diltiazem (10(-4) M), inhibited both [3H] thymidine incorporation and cell proliferation, while furosemide did not affect it. Cicletanine also inhibited PDGF-stimulated [3H] thymidine incorporation in cultured glomerular mesangial cells. We conclude that cicletanine stimulates prostacyclin synthesis and inhibits cell proliferation in cultured vascular smooth muscle cells, which may possibly be related to the intracellular calcium mobilization. Such a property might be contributory to the antihypertensive activity of cicletanine.

Animals↗
PubMed1989

[Malignant thymoma detected by thallium-201 myocardial scintigraphy].

We present two cases of malignant thymoma which showed a remarkable accumulation of thallium-201 chloride on myocardial scintigraphy. A 69 year-old man underwent stress 201Tl scintigraphy to evaluate myocardial ischemia and abnormal accumulation of thallium activity was observed in the anterior mediastinum by chance. It was more clearly visualized on delayed image. Moreover, abnormal uptake of 67Ga citrate was also observed in the same region. In another 68 year-old woman, there was high uptake on 201Tl scintigraphy, but no abnormal uptake using 67Ga. The diagnosis of malignant thymoma was confirmed by operation in each patient. These two cases had no abnormality in the mediastinum on the chest X-ray film and one of them had no uptake of 67Ga, 201Tl scintigraphy was more useful to detect malignant thymoma.

Aged↗
PubMed1989

[Automated measurement of reticulocyte count by flow cytometry. II: Analysis of the blood containing abnormal erythrocytes or giant platelets].

We have examined the influence of erythrocytes containing inclusion bodies, nucleated red cells or giant platelets on the measurement of reticulocyte count by automated machine, R-1000. Correlation of the reticulocyte count between automated and conventional method was extremely good in the blood containing red cells with Jolly bodies, Pappenheimer bodies or basophilic stippling . However, correlation was poor when the sample contained the nucleated red cells. Reticulocyte count was decreased in the blood with significant amounts of nucleated red cells. Since nucleated red cells themselves are not counted as reticulocytes in the machine, this was considered to be due to increased young reticulocytes which frequently appeared with nucleated red cells. Both cold agglutinated red cells and giant platelets apparently influenced the reticulocyte count by the R-1000. These results suggest that red cells with Jolly bodies, Pappenheimer bodies or basophilic stippling do not influence the automatic counting of reticulocytes. Although nucleated red cells, cold agglutinated red cells and giant platelets affected the reticulocyte count, the machine shows abnormal flags in most of above cases (except highly agglutinated red cells), so that one can recount reticulocytes by conventional method. We conclude the machine can safely count the reticulocytes even in the blood containing abnormal red cells or platelets.

Blood Platelets↗
PubMed1989

[Estimation of passive smoking during pregnancy by cotinine measurement and its effect on fetal growth].

Maternal cigarette smoking has been associated with some complications of pregnancy, including low birth weight and increased morbidity. Recently, it has been reported that maternal passive smoking also affects the fetal environment and causes fetal growth disturbance. In this study, we aimed to investigate the effects of maternal passive smoking on pregnant women and their fetuses by measuring cotinine concentrations in maternal urine and umbilical cord blood. The results were as follows: 1) Among 259 pregnant women, 17 cases (6.6%) were active smokers. The women who were not aware of passive smoking at all, were only 39 cases (15.1%). More than 80% of the pregnant women smoked either passively or actively each day. 2) Cotinine concentrations in both maternal urine and umbilical cord blood increased with the increase in passive smoking. Those in maternal serum, however, did not correlate with the increase in passive smoking. 3) The relative birth weight (R.B.W.) of the newborn infants delivered by the mothers whose cotinine concentration was more than 9.0ng/ml (This value represented the mean +1.5SD of the cotinine concentration in the urine from the mother who did not passively or actively smoke) was significantly lower than that of the mothers whose cotinine concentration was less than 9.0ng/ml. It is concluded that the measurement of the cotinine concentration in maternal urine or umbilical cord blood is very useful in estimating the effects of passive smoking on pregnant women. And passive smoking as well as active smoking also has a harmful effect on the fetal growth mechanism.

Birth Weight↗
PubMed1989

[Infected chronic subdural hematoma due to an ethmoiditis; a case report].

The patient was a 50-year-old female, and the initial symptoms were disturbance of consciousness and fever. CT scan showed a chronic subdural hematoma and left ethmoiditis. Emergency surgery disclosed infected chronic subdural hematoma. We classified this as infected chronic subdural hematoma caused by ethmoiditis.

Chronic Disease↗
PubMed1989

Stimulation of gastric alkaline secretion by histamine in rats: possible involvement of histamine H2-receptors and endogenous prostaglandins.

The mechanism of stimulatory action of histamine on gastric alkaline secretion was investigated in anesthetized rats. Intravenous infusion of histamine (2-8 mg/kg/hr) dose-dependently stimulated acid secretion and in the presence of omeprazole (60 mg/kg), an H+/K+-adenosine triphosphatase inhibitor, produced an increase of gastric but not duodenal alkaline secretion; the degree of gastric alkalinization was also dependent on the dose of histamine, reaching the maximal values of approximately 1.0 microEq/10 min. Cimetidine (100 mg/kg s.c.) significantly inhibited both acid and alkaline secretory responses caused by histamine, whereas indomethacin (5 mg/kg s.c.) significantly prevented the increased alkaline secretion caused by histamine as well as mucosal acidification (100 mM HCl for 10 min). Tripelennamine (10 mg/kg s.c.) had no effect on either acid or alkaline secretion. Histamine (8 mg/kg/hr) reduced the arterial blood pressure (25.3%) and increased the mucosal vascular permeability in the stomach as determined by Evans blue (160%), but these vascular responses were significantly prevented only by tripelennamine, excluding the possible contribution of the vascular effects to the increased gastric alkaline secretion. These results suggest that histamine may stimulate gastric alkaline secretion as well as acid secretion, and the mechanism of histamine-induced alkaline secretion may involve both endogenous prostaglandins and stimulation of H2-receptors.

Animals↗
PubMed1989

Role of sulfhydryls in mucosal injury caused by ethanol: relation to microvascular permeability, gastric motility and cytoprotection.

The relationship between gastric mucosal glutathione (GSH) levels, vascular permeability, gastric motility and mucosal injury caused by ethanol was investigated in rats. Oral administration of 50% ethanol (1 ml) produced elongated reddish bands of lesions in the mucosa with a significant reduction of GSH levels and increase of microvascular permeability. These lesions were significantly inhibited by pretreatment with s.c. administered diethylmaleate (DEM: 1 ml/kg), cysteamine (100 mg/kg) and 16, 16-dimethyl prostaglandin E2 (dmPGE2, 10 micrograms/kg) but worsened markedly by N-ethylmaleimide (NEM: 10 mg/kg). Irrespective of whether the animals were treated with 50% ethanol or not, the mucosal GSH levels were significantly decreased or increased, respectively, by DEM or cysteamine, and were not affected by both NEM and dmPGE2. NEM significantly enhanced the vascular permeability in the absence or presence of ethanol (greater than 10%), whereas other agents significantly inhibited only the increased vascular permeability caused by ethanol. On the other hand, gastric motility was potently and persistently inhibited by either DEM, cysteamine or dmPGE2 at the doses which prevented ethanol-induced mucosal injury, whereas NEM had no effect on the motility. These results suggest that 1) the mucosal GSH levels do not relate directly to either development or prevention of ethanol-induced gastric injury, 2) potentiation by NEM of the mucosal injury may be accounted for by its enhancement of the vascular permeability and 3) inhibition of gastric motility may be associated with prevention of mucosal lesions.

16,16-Dimethylprostaglandin E2↗