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Biomedical subjects

H Takagi

Publications and source records attributed to H Takagi.

At least 1,207 records · Page 67Linked to original sources
PubMed1982

Ontogeny of substance P-containing neuron system of the rat: immunohistochemical analysis--II. Lower brain stem.

Ontogeny of the substance P neuron system in the lower brain stem of the rat was investigated by means of the indirect immunofluorescence technique. Substance P-positive structures (cells and fibers) first appeared in the primordium of the ventral part of the nucleus tractus spinalis nervi trigemini (nVs), in the reticular formation between nucleus reticularis lateralis and nVs, and in the reticular formation between nVs and nucleus originis nervi facialis, respectively, at gestational day 14. After that time, substance P-positive structures made their appearance gradually in various areas of the lower brain stem. The present study demonstrates that substance P-positive structures appear at a very early ontogenetical stage, which suggests that substance P may play a role in the development of the lower brain stem in addition to its role as a neurotransmitter or neuromodulator.

Aging↗
PubMed1982

Responses of serum and lung angiotensin-converting enzyme activities in the early phase of pulmonary damage induced by oleic acid in dogs.

Changes in angiotensin-converting enzyme (ACE) activity in the lung tissue, edema fluid, and bloodstream were studied during induction of lung edema by oleic acid. Left lungs of 25 mongrel dogs were unilaterally treated with oleic acid (0.1 ml/kg) injected into the right atrium during right pulmonary artery occlusion for 2.5 min. Lung tissue and serum ACE activities and physiologic parameters were followed for as long as 180 min. Serum ACE activity increased to 106% at 2.5 min (p less than 0.025) and to 128% at 180 min. The ACE activity of treated lung tissue decreased compared with the zero time control in terms of tissue DNA content (at 180 min, p less than 0.05). Furthermore, the left to right activity ratio of the precipitate fraction decreased to 0.59 as early as 5 min after oleic acid injection (p less than 0.01). Changes in these ACE activities preceded those of arterial oxygen tension and base transthoracic electrical impedance. Edema fluid at 45 min had a specific activity that was 1.62 times greater than that in serum. These data indicated that the change in ACE activity reflected the impairment of pulmonary vascular endothelial cells and that the oleic acid injured endothelial cells of the pulmonary capillaries as early as 2.5 min after administration.

Animals↗
PubMed1982

Localization of LH-RH immunoreactivity in the avian retina.

The present study demonstrated numerous LH-RH--positive structures in the paddy-bird (padda orizivora) retina. LH-RH-positive cells were seen in the ganglion cell layer (GL), inner plexiform layer (IPL) and inner nuclear layer (INL). Judging from the morphological features, the former two types of cells may belong to the displaced amacrine cells and the latter to the amacrine cells. LH-RH-positive fibers were found in the nerve fiber layer, GL, IPL, INL and outer plexiform layer.

Animals↗
PubMed1982

Cerebrospinal fluid edema: a rare complication of shunt operations for hydrocephalus. Report of three cases.

Three cases are presented in which a rare complication occurred after a shunt operation for hydrocephalus. On postoperative computerized tomography (CT) scans, extensive low-density areas appeared in the white matter along the ventricular catheter. After shunt revision, gradual resolution or disappearance of the low-density area was clearly demonstrated on CT. In one patient, a collection of cerebrospinal fluid (CSF) was confirmed at operation and appeared to lie in the extracellular spaces of the white matter. The phenomenon is considered to be localized CSF edema, different from porencephaly.

Cerebrospinal Fluid↗
PubMed1982

Regional distribution of somatostatin-containing neuron system in the lower brain stem of the neonatal rat.

With the indirect immunofluorescence technique, overall distribution of somatostatin (SRIF) neuron system in the lower brain stem of the neonatal rats were examined. The present study demonstrated numerous SRIF-positive structures in various lower brain stem areas which are hardly seen in the adult lower brain stem. A possible role of SRIF in the lower brain stem was briefly discussed.

Animals↗
PubMed1982

Phylogenetical development of somatostatin-containing cells in the retina from teleosts to mammals: immunohistochemical analysis.

The distribution of somatostatin (SRIF) in the retina of various vertebrates (from teleosts to mammals) was investigated by means of indirect immunohistochemical technique. The present study revealed that there exists marked differences in topography of SRIF-containing cell systems between higher vertebrates (birds and rats) and lower vertebrates (amphibian and teleosts). The retinas of the higher vertebrates contain abundant SRIF-positive structures, while those of the lower vertebrates contain a few. Phylogenetical development of retinal SRIF-system was briefly discussed in this study.

Animals↗
PubMed1982

Localization of substance P-like immunoreactivity in the anterior eye segment of squirrels: an immunohistochemical analysis.

Localization of substance P (SP)-like immunoreactivity in the anterior eye segment of the squirrel was examined immunohistochemically. The present study demonstrates a dense network of SP-positive fibers in the ciliary body, particularly in the muscle layers, and several SP-positive fibers in the iris, in addition to scattered SP-positive fibers in the cornea. These facts strongly suggest that SP has an important role in the physiologic functions of the anterior eye segment.

Animals↗
PubMed1982

Overall distribution of glucagon-like immunoreactivity in the chicken retina: an immunohistochemical study with flat-mounts.

Pancreatic glucagon-like immunoreactivity (GLI) in the chicken retina was investigated by immunohistochemical methods with frozen sections and flat-mounts. Observations of the frozen sections showed that GLI is localized in the amacrine cells. Flat-mounts showed the GLI cells are evenly localized in the retina (n= or approximately 400/mm2) and composed to two types of cells--one is larger and the other is small. The former cell type occupies mainly the peripheral retinal region and the latter the central region. In addition, flat-mounts showed two types of GLI fiber plexuses in the inner plexiform layer; one is located in the area between laminae 2 and 3 and runs circularly and the other is located in lamina 1 and runs randomly. The relationship between GLI and cyclic AMP was also examined. an increase of the formation of cyclic AMP was caused by pancreatic glucagon in the chicken retina, suggesting that this peptide might have neurotransmitter or neuromodulator roles in the chicken retina.

Animals↗
PubMed1982

Sites of analgesic action of cyclazocine: a study using evoked-potentials at various regions of the CNS by electrical stimulation of rabbit tooth pulp.

Effects of cyclazocine on the evoked-potentials at the trigeminal subnucleus caudalis, nucleus ventralis posteromedialis of the thalamus, somatosensory S1 area of the cerebral cortex and dorsal hippocampus following electrical stimulation of the tooth-pulp were studied using the rabbit. Pentazocine and morphine were used as reference drugs. Cyclazocine in doses of 0.5-1.0 mg/kg, i.v., significantly suppressed the evoked-potential recorded at the dorsal hippocampus but not those at the other sites. The hippocampal evoked-potential was significantly inhibited also by pentazocine (5.0-10 mg/kg, i.v.) and morphine (2.0-4.0 mg/kg, i.v.). The latter but not the former significantly depressed the evoked-potential at the S1 area of the cerebral cortex. The evoked-potential at the trigeminal subnucleus caudalis was not affected by these three drugs in the doses indicated. These results suggest that cyclazocine as well as pentazocine and morphine inhibit the electrically induced painful impulses at the hippocampus and/or the afferent pathways to the hippocampus from the trigeminal subnucleus caudalis such as the tooth-pulp-hypothalamo-hippocampal pathway.

Analgesics↗
PubMed1981

Ontogeny of somatostatin-containing neuron system of the rat: immunohistochemical observations. I. Lower brainstem.

The ontogeny of the somatostatin (SRIF) neuron system in the lower brainstem of the rat was analyzed using the indirect immunofluorescence technique of Coons. SRIF-positive structures first appeared in the primordium of the ventral nucleus of the lemniscus lateralis of the rat fetus corresponding to gestational day 15 (12-14-mm embryos). On and after gestational day 15, these structures appeared in progressively more diverse areas of the lower brainstem and continued to show an increase in number and intensity up till birth. The maximum SRIF-positive structures were histochemically identified in the lower brainstem at the perinatal stage. However, after birth, the numbers of SRIF-positive structures in the lower brainstem began to decrease as the rat grew and none or only a few SRIF-positive structures were detected in the adult rats. This ontogenetical study of the SRIF neuron system on the lower brainstem of the rat strongly suggests that SRIF might play an important role in the development of the lower brainstem other than in its neurotransmitter or neuromodulator function.

Aging↗