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Biomedical subjects

H Takagi

Publications and source records attributed to H Takagi.

At least 1,243 records · Page 69Linked to original sources
PubMed1981

Localization of vasoactive intestinal polypeptide and neurotensin immunoreactivities in the avian retina.

The distribution of vasoactive intestinal polypeptide (VIP)- and neurotensin (NT)-like immunoreactivities in the chicken retina was investigated by immunohistochemistry. VIP- and NT-positive cells were found throughout the chicken retina. The majority of them were located in the proximal portion of the inner nuclear layer and the processes from these cells directed to the inner plexiform layer where they ramified, suggesting that VIP- and NT-positive cells located in this region probably are amacrine cells.

Animals↗
PubMed1981

Microgravimetric analysis of human brain tissue: correlation with computerized tomography scanning.

Microgravimetric technique was used to measure the water content of tumors and adjacent brain. Multiple 1-cu mm samples were obtained from 17 patients with neurosurgical lesions. The site of each sample was located on the appropriate computerized tomography (CT) slice, and the water content correlated with the CT attenuation coefficient. The water content of peritumor white matter in 11 patients with glioblastomas was 5% to 8% H2O/gm tissue greater than the water content of white matter measured in three normal control individuals. These areas corresponded to low CT attenuation coefficients (8 to 15 EMI units). There was no statistically significant differences between the water content of tumors and adjacent white matter, even though the CT attenuation coefficient of the tumor was often at higher value. Low CT attenuation coefficient areas surrounding meningioma, metastasis, and lymphoma always correlated with elevated water content. The greatest water content (84.7% H2O/gm tissue) was found in the white matter surrounding an arteriovenous malformation. There was no correlation between the CT attenuation coefficient of this tissue and the water content in the arteriovenous malformation. This study shows that areas of low CT attenuation coefficient may correlate with measurements of the water content of tissue, but that increased water content may exist without demonstrable changes in the CT attenuation coefficient.

Adenoma↗
PubMed1981

Metal content of shark muscle powder biological reference material.

Powdered dried shark muscle (Cephaloscyllium umbratile) is a promising biological reference material for metal analysis. Homogeneity indices (CV%) for Na, K, Zn, As, Ca, and Hg of the shark powder were within 5%. Mercury and arsenic concentrations (total Hg, 9.1 ppm dry wt, As, 99 ppm dry wt) in shark powder are relatively high. Muscle can be obtained inexpensively, and the powder can be preserved indefinitely if kept cold.

Animals↗
PubMed1980

Regional distribution of a novel analgesic dipeptide kyotorphin (Tyr-Arg) in the rat brain and spinal cord.

Using high performance liquid chromatography, we measured kyotorphin content in discrete regions of the rat brain and spinal cord in an attempt to clarify its physiological significance. Higher concentrations of the dipeptide were found in the midbrain, pons plus medulla oblongata and dorsal cord, which are the most sensitive sites for the microinjection of morphine and/or electrical stimulation-induced analgesia. Kyotorphin may play a physiological role in pain control in the central nervous system.

Animals↗
PubMed1980

Analgesic action of intrathecal and intracerebral beta-endorphin in rats: comparison with morphine.

beta-Endorphin and morphine were given into the nucleus reticularis gigantocellularis (NRGC), spinal subarachnoid space and third ventricle of rats, and the antinociceptive effects were assessed by the tail-pinch method. The NRGC was 4-5 times as sensitive to beta-endorphin as was the spinal subarachnoid space and third ventricle, while the NRGC was 13-19 times as sensitive to morphine as were the other regions. Thus, it would appear that beta-endorphin has more sites of action for the production of analgesia than does morphine.

Analgesics↗
PubMed1980

Ascending components of the medial forebrain bundle from the lower brain stem in the rat, with special reference to raphe and catecholamine cell groups. A study by the HRP method.

The afferent connection of the medial forebrain bundle (MFB) arising from the lower brain stem have been investigated by means of horseradish peroxidase (HRP) with sensitive substrate, the injection was made iontophoretically into MFB at various levels. After injection of HRP into MFB, a significant number of HRP-labeled neurons were observed in the following structures of the lower brain stem: (1) raphe nuclear group, (2) locus coeruleus, (3) n. laterodorsalis tegmenti, (4) parabrachial area, (5) A1, A2, A4, A5 and A7 areas where noradrenaline-containing neurons were disseminated, (6) A8, A9 and A10 areas which contain dopamine neurons, (7) surrounding area of the fasciculus longitudinalis medialis at the level of the n. propositus hypoglossi, (8) n. prepositus hypoglossi and (9) mesencephalic gray matter. As a rule, the ascending projections are ipsilateral and course in the medial part of MFB. Regarding the raphe nuclei, we have demonstrated that the caudal raphe nuclei, such as n. raphe magnus and obscurus (but not n. raphe pallidus), also send their axons to the hypothalamus. Particularly, the axons of n. raphe magnus ascend in MFB to reach the level of the preoptic or anterior septal areas. Furthermore, in accordance with previous reports, HRP-labeled cells were also identified in the n. raphe dorsalis, centralis superior and pontis, respectively. It should be further noted that labeled cells appeared in the n. linearis caudalis. In addition, the present study indicates a number of non-aminergic cell groups as sources of ascending mfb fibers. On the whole, the present study further clarified the organization of the components of the MFB ascending from the lower brain stem, and provided some additional anatomical substrates for the physiology of the control of the forebrain by the lower brain stem neurons.

3,3'-Diaminobenzidine↗
PubMed1980

Ascending and descending components of the medial forebrain bundle in the rat as demonstrated by the horseradish peroxidase-blue reaction. I. Forebrain and upper brain stem.

The ascending and descending components of the medial forebrain bundle (MFB) were investigated by means of horseradish peroxidase (HRP) with a sensitive substrate. The HRP was injected iontophoretically into the MFB at various levels from the anterior commissure to the posterior hypothalamus. In order to prevent the diffusion of HRP to other brain areas, a double micropipette system was used. The descending components of the MFB are derived from (1) the anterior cingulate area, infra- or prelimbic area, and sulcal cortex, (2) the lateral septal nucleus and diagonal band, (3) the bed nucleus of the stria terminalis, (4) the paraventricular nucleus (5) the substantia innominata, (6) the amygdaloid complex (AM), (7) the ventromedial (VM) and dorsomedial (DM) hypothalamic nuclei, (8) the entopeduncular nucleus and (9) nucleus periventricularis stellatocellularis. The ascending components of the MFB originate in: (1) the medial preoptic nucleus, (2) the nucleus periventricularis stellatocellularis and rotundocellularis, (3) the posterior hypothalamic nucleus, (4) the parafascicular nucleus, (5) the ventral premammillary nucleus, (6) the substantia grisea periventricularis, (7) the lateral habenular nucleus, (8) the VM and DM, (9) the paratenial nucleus, (10) the AM and (11) the arcuate nucleus.

Animals↗
PubMed1980

Effects of tyrosyl-arginine (kyotorphin), a new opioid dipeptide, on single neurons in the spinal dorsal horn of rabbits and the nucleus reticularis paragigantocellularis of rats.

The effects of a new endogenous opioid dipeptide (Tyr-Arg), kyotorphin, on single unit activities recorded from the lamina V type neurons in the spinal dorsal horn and the neurons in nucleus reticularis paragigantocellularis (NRPG) of the medulla oblongata were investigated in the rabbit and rat, respectively. Microelectrophoretically applied kyotorphin predominantly depressed the lamina V type neurons but excited the NRPG neurons. Such predominant effects were antagonized by naloxone. These results suggest that kyotorphin has qualitatively similar actions to those of enkephalins in both central regions examined.

Animals↗
PubMed1980

Topographic organization of the projection from the forebrain subcortical areas to the hippocampal formation of the rat.

Using the technique of iontophoretic microinjection of horseradish peroxidase, the present study disclosed the complexity and high degree of the topographic organization in the forebrain subcortical afferents to the different regions of rat hippocampus, e.g. diagonal band, posterior (PH), dorsomedial and rostral lateral hypothalamic nuclei chiefly project to the rostrodorsal part (DRA) and caudal gyrus dentatus including CA3, the supramammillary area predominantly to the rostroventral area (VRA), the area lateral to PH to the DRA and VRA, substantia innominata and some thalamic nuclei (n. reuniens, n. lateralis thalami, n. anterior ventralis and n. lateralis thalami pars posterior) to the dorsal subiculum, respectively.

Animals↗