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Biomedical subjects

T Maeda

Publications and source records attributed to T Maeda.

At least 1,189 records · Page 66Linked to original sources
PubMed1985

Adrenergic neurons in human brain demonstrated by immunohistochemistry with antibodies to phenylethanolamine-N-methyltransferase (PNMT): discovery of a new group in the nucleus tractus solitarius.

Adrenaline neurons in human brain were demonstrated by immunohistochemistry using antibody to phenylethanolamine-N-methyltransferase (PNMT), the final enzyme in the pathway of adrenaline synthesis, using fixed frozen sections and a highly sensitive free floating technique which utilizes metallization. Small densely packed PNMT-immunoreactive neurons were observed to form a nucleus lying just ventrolateral to the area postrema and in the dorsal part of the nucleus tractus solitarius. Larger adrenergic neurons were also present in and around the lateral reticular nucleus and in relationship with the dorsal motor nucleus of the vagus in regions equivalent to the C1 and C2 groups in rats. Longitudinally oriented PNMT-positive axons constitute a subset of tyrosine hydroxylase-immunoreactive axons in the dorsomedial reticular formation.

Adrenergic Fibers↗
PubMed1985

Distribution of GABA-T-intensive neurons in the rat hindbrain.

The pharmacohistochemical method previously used to identify the distribution in rat brain of gamma-aminobutyric acid transaminase (GABA-T)-intensive neurons has been applied to the rat pons and medulla. The method involves systemic administration of the irreversible GABA-T inhibitor Gabaculine and the detection, 12 to 15 hours after the injection of the newly synthesized GABA-T by histochemical means. GABA-T-intensive neurons were found to be rich in the following hindbrain structures: inferior colliculus, nuclei of the raphe system, nuclei parabrachialis dorsalis and ventralis, nucleus cuneiformis, nucleus vestibularis medialis, nucleus tractus spinalis nervi trigemini, nucleus vagus, nucleus cochlearis, nucleus reticularis lateralis, nucleus ambiguus, nucleus cuneatus lateralis, inferior olive, and reticular formation of the pons and medulla. Neurons of the deep cerebellar nuclei and the rostral portion of the lateral vestibular nucleus were negative for GABA-T but were surrounded by granular staining indicative of impinging GABA-T-rich nerve endings. These results provide further support for the hypothesis that GABA neurons are far more GABA-T-intensive than other neurons in the central nervous system.

4-Aminobutyrate Transaminase↗
PubMed1985

Improvement of dissolution and suppository release characteristics of flurbiprofen by inclusion complexation with heptakis(2,6-di-O-methyl)-beta-cyclodextrin.

The inclusion behavior of methylated beta-cyclodextrins, heptakis(2,6-di-O-methyl)-beta-cyclodextrin and heptakis-(2,3,6-tri-O-methyl)-beta-cyclodextrin in solution and the solid state was compared with that of natural beta-cyclodextrin using an anti-inflammatory drug, flurbiprofen, as a guest molecule. Stability constants were determined by the solubility method at various temperatures, and the thermodynamic parameters were calculated for inclusion complex formation in aqueous solution. The solid complexes were obtained in a molar ratio of 1:1, and their dissolution behavior and release from suppository bases were examined. The data suggest that the inclusion mode of the complex with 3 is somewhat different from that of the complexes with 1 and 2. From a practical point of view, 2 seems to be particularly useful for improving the pharmaceutical properties of flurbiprofen in various dosage forms.

Chemistry, Pharmaceutical↗
PubMed1985

Phosphatase activities in human glioma cells as revealed by light and electron microscopy--a preliminary study.

Alkaline phosphatase (ALPase) and Mg2+-activated ATPase (Mg2+-ATPase) activities were demonstrated in human brain tumors by light and electron microscopy. Four cases of glioma, i.e., two cases of astrocytoma, grade II, and two cases of glioblastoma, were used as materials. At the light microscopic level, Mg2+-ATPase activity was observed in the capillary wall and glial cells of both astrocytoma and glioblastoma. ALPase activity was restricted to the capillary wall. Its activity was stronger in glioblastoma than in astrocytoma. By electron microscopy, in astrocytoma, reaction product representing Mg2+-ATPase activity was distributed in the plasma membranes of endothelial cells and pericytes. Activity was primarily localized at the abluminal surface of endothelial cells and the surface of pericytes facing endothelium. The plasma membrane of glial cells was also positive. ALPase activity revealed essentially the same distribution pattern in blood vessels as above. In glioblastoma, on the other hand, activities of both phosphatases were markedly positive on the luminal surface of the plasma membrane of endothelial cells. They were much stronger than those along the abluminal endothelial surface. Phosphatase activities in brain tumor appear to change in localization pattern in association with glioma malignancy. This might reflect a functional aspect of changes in blood-brain barrier in glioma.

Alkaline Phosphatase↗
PubMed1985

CO2 laser in treating carcinoma of the tongue.

Since 1980, we have been using CO2 laser in treating carcinomas of the tongue. Carcinomas confined to the mucosa have been treated with laser excision alone. Five patients were treated in this way and they are all alive with no evidence of disease. Follow-up ranges from 11 months to 3 years. Carcinomas with a superficial muscular invasion have been treated with mass reduction laser surgery followed by chemoradiotherapy. There were 19 patients which fell in this category. Of these 19, 17 are alive with no evidence of disease, 1 died of an intercurrent disease, and 1 died of cervical metastasis. Follow-up ranges from 9 months to 5 years and 1 month. For carcinomas with a deep muscular invasion, we first attempted an induction chemotherapy consisting of cisplatin and pepleomycin. When the chemotherapy was effective, we applied mass reduction laser surgery followed by chemoradiotherapy. Two patients were treated in this way. One is alive with no evidence of disease (11-month follow-up) whereas the other died of pulmonary metastasis. Following the treatments using laser, speech intelligibility is much better than after extensive surgeries.

Adult↗
PubMed1985

Bioluminescent assay as a potential method of rapid susceptibility testing.

A method of rapid susceptibility testing by bioluminescent assay was developed. Correlation between the 50% inhibition dose of antimicrobics for bacterial adenosine triphosphate measured by bioluminescent assay and the minimum inhibitory concentration obtained by the broth dilution method was satisfactory. In the bioluminescent assay the incubation time required was only 90 min.

Adenosine Triphosphate↗
PubMed1985

Adenosine and dipyridamole: actions and interactions on the contractile response of guinea-pig ileum to high frequency electrical field stimulation.

The action of adenosine on the myenteric plexus-longitudinal muscle strips from guinea-pig ileum to high frequency electrical field stimulation (10 Hz) was investigated. Electrically induced contractions were reduced markedly by tetrodotoxin (0.2 microM) and atropine (1 microM), and partially by noradrenaline (3 microM) and morphine (3 microM). Adenosine, adenosine 5'-monophosphate (AMP) and adenosine triphosphate (ATP) produced a concentration-dependent inhibition of the high frequency contractions over the range of 0.1-100 microM, the most potent being adenosine. The concentration-response curve for adenosine was significantly shifted to the left by dipyridamole (10 nM), while dipyridamole at higher concentrations (30 nM-10 microM), depressed the contraction markedly by itself. Dipyridamole decreased [3H]-adenosine uptake into strips of ileum in a concentration-dependent manner. There was a significant correlationship between the reduction of adenosine uptake and the inhibition of the contraction induced by dipyridamole (r = 0.970). In strips desensitized to adenosine or treated with adenosine deaminase, the inhibitory effect of dipyridamole was significantly reduced. The present investigation revealed that adenosine depressed responses of guinea-pig ileum to high frequency electrical stimulation and suggested that the inhibitory effect of dipyridamole may be closely associated with the behaviour of endogenous adenosine or related compounds.

Adenosine↗
PubMed1985

Regional cerebral blood flow in schizophrenic disorders.

Regional cerebral blood flow was measured using a 133Xe inhalation technique in 16 schizophrenic patients and 20 healthy volunteers. The bilateral frontal blood flows in the patient groups were significantly lower than in the control group. In addition, the patient group having auditory hallucination showed a significantly increased blood flow predominantly in the left temporal region. On the other hand, the patient group without auditory hallucination showed a slightly increased flow in the right temporal region. These findings indicate that there are a hypofrontal activity and also a hypertemporoparietal activity in schizophrenics.

Adult↗
PubMed1985

Possibilities for adenosine modulation of peristaltic reflex in guinea pig isolated ileum.

The possibilities of participation of adenosine in the peristaltic reflex of guinea pig ileum was studied pharmacologically and histologically. Adenosine apparently depressed the peristaltic activity induced by elevation of intraluminal pressure from zero to 1-8 cm H2O, and the extent of the depression somewhat decreased in proportion to the elevation in intraluminal pressure. Also, dipyridamole depressed the peristaltic activity by itself; however, the extent of the depression significantly increased in proportion to the elevation in intraluminal pressure. On the other hand, in the presence of dipyridamole, the elevation of the intraluminal pressure from zero to 1-8 cm H2O elicited an 3H-output increase from 3H-adenosine preloaded guinea pig isolated ileum, with the effect being more pronounced as the pressure was increased. In contrast, the peristaltic activity was more pronounced at lower pressurization. Atropine greatly depressed the peristaltic response but did not affect 3H-output induced by 4 cm H2O pressurization. Tetrodotoxin depressed both markedly. Fluorescence histochemical localization of quinacrine, which binds to adenosin triphosphate (ATP), revealed dense nerve cell bodies and fine interconnecting strands in the ileal myenteric plexus of Auerbach. Also, in microradioautographs of ileal longitudinal muscle incubated with 3H-adenosine, the concentration of developed silver grains was localized in the ganglion cells and in the musculature as varicose fibre. From these results, evidence is provided that the peristalsis of guinea pig ileum may be physiologically modulated by endogenous adenosine, which may be released from neuronal elements of the myenteric plexus in response to the applied intraluminal pressure.

Adenosine↗
PubMed1985

Two cases of pulmonary Waldenström's macroglobulinemia.

Two cases of Waldenström's macroglobulinemia (WMG) with principally pulmonary manifestation are presented. The disease in both cases was discovered from abnormal shadow in chest x-ray films, without classic features of the disease such as anemia, lymphadenopathy, hepatosplenomegaly or visual disturbance. Transbronchial biopsy (case 1) and open lung biopsy (case 2) revealed diffuse infiltration of lymphoplasmacytoid cells. In both cases, the cytoplasm of proliferating cells stained for monoclonal IgM by the peroxidase-antiperoxidase method. Immunologic examination revealed that almost all tumor cells obtained from bronchoalveolar lavage fluid (case 1) and cell suspension of the right lung (case 2) had monoclonal surface immunoglobulin for IgM. These data established the diagnosis of pulmonary WMG. These cases indicate the importance of immunologic studies for establishing a diagnosis of pulmonary WMG, since histologic findings in biopsy specimens and clinical features are often not specific enough for making this diagnosis.

Female↗
PubMed1985

Morphology of ectopic ventricular beats and their relationship to ventricular tachycardia in acute myocardial ischemia.

The features of ventricular arrhythmia in coronary spasm induced by ergonovine were examined to elucidate the characteristics of ventricular arrhythmia in acute myocardial ischemia. The coupling intervals and configurations of the QRS wave of the premature ventricular beats (PVBs) were extremely variable, even in the same individual and at the closer time phases. The prematurity index (R-R'/QT) of PVBs with the right bundle branch block (RBBB) pattern was significantly smaller than with the left bundle branch block (LBBB) pattern. The vulnerability index (R-RX QT/R-R') of PVBs with the RBBB pattern was significantly larger than with the LBBB pattern. The incidence of PVBs with the RBBB pattern (50.4%) was slightly larger than with the LBBB pattern (40.5%). PVBs deteriorated into ventricular tachycardias (VTs) in 29 (24.8%) of 117 cases with the RBBB pattern and in 11 (11.7%) out of 94 cases with the LBBB pattern. Thus, PVBs with the RBBB pattern were more likely to progress to VT than with the LBBB pattern. But it is difficult to assess the clinical significance of PVBs from their QRS morphology alone, because 11 (27.5%) of 40 cases of VT were initiated by PVBs with the LBBB pattern.

Acute Disease↗
PubMed1985

Immunohistochemical demonstration of the nerves in human dental pulp with antisera against neurofilament protein and glia-specific S-100 protein.

Human dental pulp was investigated by an immunofluorescence method using antisera against neurofilament protein (NFP) and glia-specific S-100 protein. Nerve fibers coursing through the pulp were selectively stained with the anti-NFP serum, and their Schwann sheath with the S-100 antiserum. In addition to a definitive demonstration of the subodontoblastic nerve plexus, we found another hitherto unknown nerve plexus composed of delicate fibers at the base of the odontoblastic layer. This study shows that immunohisto chemical techniques using antisera against nervous system-specific proteins are superior to previous silver impregnation methods, due to their specificity and constancy in reaction.

Dental Pulp↗