Search PubMed⌕ Search

Biomedical subjects

K Takami

Publications and source records attributed to K Takami.

At least 109 records · Page 6Linked to original sources
PubMed1991

Effects of a proton pump inhibitor, AG-1749 (lansoprazole), on reflux esophagitis and experimental ulcers in rats.

The effects of (+/-)-2-[[[3-methyl-4-(2,2,2-trifluoroethoxy-2- pyridyl]methyl]sulfinyl]-1H-benzimidazole (lansoprazole, AG-1749) and famotidine on various experimental ulcers in rats were compared. AG-1749 inhibited reflux esophagitis; gastric lesions induced by water-immersion stress, aspirin or ethanol; and duodenal ulcers induced by cysteamine or mepirizole in a dose-dependent manner: the ID50 values were 0.7, 2.4, 0.7, 8.5, 1.1 and 0.3 mg/kg, p.o. or i.d., respectively. Famotidine inhibited reflux esophagitis with an ID50 value of 12.9 mg/kg, but did not cause 50% inhibition of ethanol-induced gastric lesions even at 100 mg/kg, although it showed almost the same or a little stronger potency on other experimental ulcers: ID50 values were 0.3-1.4 mg/kg. Significant aggravation of ethanol- or water-immersion stress-induced lesions was observed in rats given famotidine at 30 mg/kg twice daily for 4 days, but not in rats given AG-1749 at 10 mg/kg twice daily. Administration of AG-1749 for 14 consecutive days markedly accelerated the healing of acetic acid-induced gastric and duodenal ulcers, and the healing effect was significant at 10 and 30 mg/kg/day, p.o. Famotidine also accelerated the healing of ulcers, but its potency was less than that of AG-1749. The results of this study indicate that although AG-1749 is slightly less potent than famotidine in inhibiting acutely induced gastroduodenal lesions, this agent is superior to famotidine in promoting the healing of ulcers and in inhibiting reflux esophagitis and ethanol-induced gastric lesions.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1991

Effect of thyrotropin-releasing hormone (TRH) in experimental spinal cord injury: a quantitative histopathologic study.

Spinal cord injuries in rats were experimentally produced by compressing the cord (T11 vertebra level) for 60 min with stainless steel screws. Morphometric analysis of the injured cord revealed that at 14 days post-injury, there were significant correlations between the neurologic score (NS) and all morphometric parameters, including total cross-sectional area (rs = 0.438), lesioned area (rs = -0.421) and area of the gray (rs = 0.377) and white matter (rs = 0.704). Although rats treated with thyrotropin-releasing hormone (TRH; 22.5 mg/kg, s.c., twice daily for 7 days starting 24 hr post-injury) showed significant improvement in NS 14 days post-injury, there were no significant differences in morphometric parameters between saline- and TRH-treated rats. In addition, no significant correlation was observed between NS and any of the morphometric parameters in TRH-treated rats, even though there was a significant correlation between the area of white matter and NS in saline-treated rats. These results suggest that neurologic recovery closely reflects the histopathological changes evident at the injury site in the present model, and that the improvement of neurologic status seen in rats with cord injury given TRH starting 24 hr post-injury is not due to protection against progression of neural damage at the injury site.

Animals↗
PubMed1989

A study of the retinal ganglion cell which has an uncrossed bifurcating axon in the albino rat.

Injection of the fluorescent tracers, Evans blue (EB) and Primulin (Pr), or EB and 4',6-diamino-2-phenylindol dihydrochloride (DAPI), respectively, into the dorsal nucleus of the lateral geniculate body and the superior colliculus on the ipsilateral side have demonstrated the existence of retinal ganglion cells having uncrossed bifurcating axons in the albino rat. Our fluorescent labeling study confirms the existence of double-labeled cells, namely, retinal ganglion cells having bifurcating axons, in the peripheral temporoventral half (temporoventral crescent) of the ipsilateral retina, coupled with the single-labeled cells from each structure. A percentage estimation of these three kinds of labeled cells revealed that the double-labeled cells greatly occupy a majority of the entire labeled cells and no ostensible difference was evident in the proportion of double-labeled cells to the entire labeled cells between both the ipsilaterally and contralaterally projecting cell groups.

Animals↗
PubMed1989

Diagnostic value of QRST isointegral maps in detecting myocardial infarction complicated by bundle branch block.

The clinical usefulness of QRST isointegral maps (IQRST map) for detecting myocardial infarction that was complicated by intraventricular conduction disturbances was evaluated in patients with right bundle branch block (group RBBB, 64 patients) and left bundle branch block (group LBBB, 40 patients) by comparison with the normal mean IQRST map derived from 50 normal subjects. Myocardial infarction complicated the conduction disturbances in 24 of the 64 RBBB and in 18 of the 40 LBBB patients. A correlation coefficient was used for assessing the similarity of each map pattern with the normal mean IQRST map. The difference map was made by subtracting the average normal IQRST map from each abnormal IQRST map, and those differences that were less than 2 SD from the mean were retained as a significant area. The number of leads and their sum of differences were used to represent the size of the difference map. Correlation coefficients were significantly (p less than 0.001) smaller in patients with bundle branch block complicated by myocardial infarction than in patients with conduction disturbances not complicated by myocardial infarction. A significant area emerged in the difference map in all patients with myocardial infarction complicated by conduction disturbances. The emergence of a significant area revealed high diagnostic accuracy for detecting myocardial infarction in group RBBB (89.1%). The size of a significant area in a difference map was significantly larger in cases with complicated myocardial infarction than in cases with uncomplicated myocardial infarction in either group RBBB or group LBBB (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

Sites of origin of ventricular premature beats in patients with and without cardiovascular disease evaluated by body surface mapping.

The site of origin of ventricular premature beats (VPBs) was estimated by QRS maps and its distribution in two patient groups was studied. VPB origin was determined by comparing the body surface map of VPBs with that during electrical stimuli applied at various sites of the ventricle. Subjects were 100 patients without obvious underlying cardiovascular disease (Group N) and 289 patients with various heart diseases (Group D). Nine sites of origin of VPB were identified. In group N, VPBs of right ventricular origin were noted in 69%, those of left ventricular origin in 6%. There was a relatively high incidence of VPBs with foci estimated to be the divisions of the left bundle branch, and the age of patients with these VPBs was young. In Group D, VPBs of left ventricular origin showed a higher incidence (34.6%) and those of right ventricular origin a lower incidence (41.2%) than those in group N. The data suggest that VPBs originating from the apex and base of the ventricle strongly indicate the presence of basic heart disease and that VPBs originating in or near the divisions of the left bundle branch in younger subjects do not necessarily indicate cardiac disease.

Adolescent↗
PubMed1987

Calcitonin gene related peptide stimulates adenylate cyclase activity in rat striated muscle.

Rat calcitonin gene related peptide (CGRP) and salmon calcitonin (CT) stimulated adenylate cyclase activity in a dose-dependent manner in the rat diaphragm and in the kidney. The ED50 value of rat CGRP was lower and that of salmon CT was higher in the diaphragm than in the kidney. These results suggest that CGRP stimulates adenylate cyclase activity in the striated muscle by reacting with sites distinct from the site in the kidney.

Adenylyl Cyclases↗
PubMed1986

Effect of calcitonin gene-related peptide on the cyclic AMP level of isolated mouse diaphragm.

The effect of calcitonin gene-related peptide (CGRP) on the cyclic nucleotide level in isolated mouse diaphragm was investigated. CGRP at concentrations of up to 1 microM caused dose-dependent increases in cyclic AMP levels but had no effect on cyclic GMP levels. At 1 microM, CGRP increased cyclic AMP levels by about 2.7-fold. Moreover, in the presence of phosphodiesterase inhibitor (Ro 20-1724), CGRP still caused even greater dose-dependent increases in cyclic AMP levels. Even in the presence of propranolol, a beta-adrenergic antagonist, CGRP stimulated increased cyclic AMP levels. In addition, specific binding of CGRP was observed in mouse diaphragm. All these results suggest that CGRP increases intracellular cyclic AMP levels via a CGRP receptor but not the beta-adrenergic receptor.

Animals↗
PubMed1985

Effect of calcitonin gene-related peptide on contraction of striated muscle in the mouse.

We have found ultrastructurally calcitonin gene-related peptide-like immunoreactivity in the axon terminal within the synaptic trough of neuromuscular junction of the mouse. We determined, using pharmacological means, with a phrenic nerve-diaphragm preparation, that this peptide enhances muscle contraction during stimulation of the nerve fibers or direct stimulation of the muscle. This effect is probably brought about via the receptor for this peptide not the acetylcholine receptor.

Animals↗
PubMed1985

Coexistence of calcitonin gene-related peptide and substance P-like peptide in single cells of the trigeminal ganglion of the rat: immunohistochemical analysis.

The localization of calcitonin gene-related peptide (CGRP) and substance P (SP) in the rat trigeminal ganglion was examined by means of the indirect immunofluorescent method. About 40% of neurons in the ganglion contained CGRP-like immunoreactivity (CGRPI), while about 20% of neurons showed SP-like immunoreactivity (SPI). In serial sections, nearly all the SPI neurons contained CGRPI.

Animals↗
PubMed1985

Immunohistochemical evidence for the coexistence of calcitonin gene-related peptide- and choline acetyltransferase-like immunoreactivity in neurons of the rat hypoglossal, facial and ambiguus nuclei.

The present immunocytochemical study demonstrates that calcitonin gene-related peptide-like immunoreactivity (CGRPI) coexists with acetylcholine in single cells of hypoglossal, facial and ambiguus nuclei. The experiments were done using alternate frozen sections from relevant regions of the rat brain. We further show that CGRPI is localized in the nerve terminals that form neuromuscular junctions in the tongue muscles.

Animals↗
PubMed1985

Somatostatinergic neurons in the insular cortex project to the spinal cord: combined retrograde axonal transport and immunohistochemical study.

A double-labeling method combining immunohistochemistry and a retrograde tracer technique using biotin-horseradish peroxidase (B-HRP) was employed to identify a descending somatostatinergic fiber system from the insular cortex to the spinal cord. Injection of B-HRP into the spinal cord at cervical or lumbar levels resulted in the labeling of a number of neurons in the insular cortex. Simultaneous immunostaining revealed the existence of double-labeled neurons in the insular cortex. The result provides direct evidence for the presence of a descending somatostatinergic pathway from the insular cortex to lumbar levels of the spinal cord.

Animals↗
PubMed1985

Localization of chick retinal visinin-like immunoreactivity in the rat forebrain and diencephalon.

The present study is an examination, using an indirect immunofluorescence method, of the distribution of visinin, a 24,000 dalton peptide, in the rat forebrain and diencephalon. Immunoreactive structures were localized in the neuronal elements showing an uneven distribution. Immunoreactive neurons were found in the olfactory bulb, anterior olfactory nucleus, cerebral cortex, amygdaloid complex, ventral portion of the nucleus caudatus putamen, septal area, nucleus accumbens, nucleus paratenialis, nucleus rhomboideus, nucleus reuniens, nucleus paraventricularis hypothalami, nucleus supraopticus, nucleus anterior hypothalami, preoptic area, hypothalamic periventricular nucleus, nucleus mammillaris medialis, medial habenular nucleus, zona incerta, nucleus lateralis thalami, nucleus tractus optici and gyrus dentatus. Immunoreactive fibers were observed in the above areas, particularly near the labelled cells, forming fiber plexuses of varying density. In addition, dense plexuses were also seen in the globus pallidus, anteroventral nucleus of the thalamus, substantia nigra and hippocampus. In the former three structures, no labelled cells were present and in the latter, a few scattered neurons were found, indicating that these fibers originate from extrinsic sources.

Animals↗
PubMed1985

Topographic localization of calcitonin gene-related peptide in the rat brain: an immunohistochemical analysis.

The distribution of immunoreactive calcitonin gene-related peptide in the rat brain was investigated by means of an indirect immunofluorescence method. In addition to previously reported calcitonin gene-related peptide-like immunoreactive structure-containing sites such as the nucleus ambiguus, nucleus originis nervi facialis, nucleus originis nervi hypoglossi, nucleus peripeduncularis and nucleus parabrachialis, the present study demonstrated a far wider distribution of calcitonin gene-related peptide-like immunoreactive structure-containing cells in the rat brain, i.e. the nucleus hypothalamicus lateralis, nucleus ventromedialis thalami, colliculus superior, lemniscus lateralis, gyrus dentatus, nucleus olivaris superior, nucleus tractus solitarii, nucleus cuneiformis, nucleus parabigeminalis and a proportion of the Purkinje cells. We have also demonstrated a more extensive network of calcitonin gene-related peptide-like immunoreactive fibers distributed in various areas throughout the rat brain than has been reported previously such as the colliculus inferior, nucleus olivaris superior, nucleus vestibularis lateralis and inferioris, and nucleus cochlearis dorsalis and ventralis, etc.

Animals↗
PubMed1985

Distribution of calcitonin gene-related peptide in the rat peripheral nervous system with reference to its coexistence with substance P.

This immunocytochemical study, using a double-staining method, showed that calcitonin gene-related peptide-like immunoreactive structures are widely distributed in the peripheral nervous system and that many of them coexist with substance P-like immunoreactive structures in single sensory ganglion cells. Neurons positive for calcitonin gene-related peptide but negative for substance P were detected in sensory ganglia. These cells were large (about 30-45 micron in diameter); these primary sensory neurons containing calcitonin gene-related peptide can probably act independently of substance P. There were neurons containing calcitonin gene-related peptide without substance P in the pterygopalatine ganglion, although these cells were less numerous than in the sensory ganglia. In consecutive sections, calcitonin gene-related peptide-like structures occurred in thyroid parafollicular cells, which also contain calcitonin. This suggested that messenger RNA for producing calcitonin gene-related peptide is also present in the thyroid, and like calcitonin, calcitonin gene-related peptide may have a peripheral physiological role.

Animals↗