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T Sugai

Publications and source records attributed to T Sugai.

At least 19 recordsLinked to original sources
PubMed1992

Periarterial lymphoid sheath in the rat spleen: a light, transmission, and scanning electron microscopic study.

The periarterial lymphoid sheath (PALS) in the rat spleen was studied by light, transmission, and scanning electron microscopy. The PALS was divided into three regions: the central region, peripheral region, and marginal zone bridging channel. In the central region, lymphocytes were easily washed away by perfusion. Large spaces were found between flat reticular cells or in large meshworks of stellate reticular cells; these may be deep lymphatic vessels. True lymphatic vessels were found in the central region near the hilus. In the marginal zone bridging channel, flat reticular cells surrounded the central artery in a circumferential pattern and formed channel-like spaces between the flat reticular cells. These spaces were connected with the meshwork of the red pulp reticular cells and may be a route for lymphocytes between the deep lymphatic vessels and the red pulp. In the peripheral region of the PALS, it was usually difficult to wash away free cells by perfusion, and free cells were found among the reticular cells. In places in the peripheral region, however, free cells were washed away. It is suggested that the lymph flow may start from the region surrounding the PALS, and that the peripheral region of the PALS may also be another route for lymphocyte migration.

Animals↗
PubMed1992

Actions of cholinergic agonists and antagonists on the efferent synapse in the frog sacculus.

Intracellular recordings were made from hair cells in the frog saccular epithelium isolated with its innervating nerves. Inhibitory post-synaptic potentials (IPSPs) were recorded from hair cells when the efferent fibers were activated by electrical stimulation. The effects of acetylcholine (ACh), cholinomimetics, and cholinergic antagonists on the efferent synapse were studied in a preparation where the IPSPs can be observed directly. ACh or carbachol (CCh) produced a transient membrane hyperpolarization with a decrease in input resistance followed by an abolition or reduction of the IPSP. In a low Ca2+ medium where efferent synaptic activity was abolished, ACh or CCh still induced hyperpolarization, though the response appeared to be smaller than that in normal medium. Neither nicotinic (dimethyl-4-phenyl-piperazinium (DMPP), phenyltrimethylammonium (PTMA) and nicotine) nor muscarinic (muscarine, methacholine, bethanechol and oxotremorine) agonists induced the membrane hyperpolarization, but the former drugs inhibited the IPSPs while the latter drugs did not. Both d-tubocurarine and atropine inhibited the IPSP, but the d-tubocurarine was more potent, causing inhibition even at a dose of 0.5 microM while 2 microM or more atropine was needed. The ACh- or CCh-induced hyperpolarization was inhibited completely by d-tubocurarine (5 microM), but only slightly by atropine (5 microM). These results may indicate that the IPSP and the effects of ACh or CCh are based on a direct interaction between ACh or CCh and ACh receptors on the hair cells.

Acetylcholine↗
PubMed1992

Eosinophil cationic protein in peripheral blood of pediatric patients with allergic diseases.

We have studied the levels of eosinophil cationic protein (ECP) and tumour necrosis factor (TNF) in peripheral blood obtained from 68 children with bronchial asthma and 11 children with atopic dermatitis. The ECP mean concentrations of the patients were 23.7 +/- 21.4 micrograms/l and 21.2 +/- 18.7 micrograms/l for bronchial asthma and atopic dermatitis respectively, which were significantly higher than the control value, 5.8 +/- 2.3 micrograms/l (P less than 0.005). TNF was unmeasurable in almost all the samples and no significant difference was observed between normal controls and asthmatic children. A significant correlation was observed between serum levels of ECP and blood eosinophil counts in both diseases (r = 0.873; P less than 0.01 and r = 0.740; P less than 0.01, respectively). However, no obvious correlation was observed between serum levels of ECP and IgE levels. ECP levels were significantly reduced by treatment and normalized in parallel with blood eosinophil counts in the patients with total IgE levels less than 800 U/ml. Irrespective of the total IgE levels, the reduction of serum ECP levels was correlated with a decrease in the number of asthmatic attacks and/or improvement of pulmonary function. These results suggest that the ECP levels in peripheral blood indicate an increased activity of eosinophil and would be a more useful marker than eosinophil counts for making clinical analyses and estimating treatment efficacy in paediatric patients with allergic diseases.

Adolescent↗
PubMed1991

Vasorelaxant and hypotensive effects of tilisolol hydrochloride (N-696) in isolated rat thoracic aorta and pithed rats.

Vasorelaxant and hypotensive effects of tilisolol hydrochloride (N-696) in isolated rat thoracic aorta and pithed rats were investigated. In rat thoracic aorta pre-contracted with KCl (20 mM), tilisolol (10(-5)-10(-3) M) produced concentration-related relaxation, but nadolol and atenolol did not significantly inhibit the responses to 20 mM KCl. The concentration-relaxation curve of tilisolol underwent rightward parallel shifts only to a limited extent in the presence of glibenclamide, a specific antagonist of K+ channel openers. Glibenclamide also shifted the concentration-relaxation curve of cromakalim to the right and in a parallel manner, whereas it did not change that of propranolol. In pithed rats, tilisolol (0.5-2.0 mg/kg, i.v.), but neither nadolol nor atenolol, caused a dose-dependent decrease in diastolic blood pressure and a slight increase in heart rate. Following treatment of the preparation with glibenclamide, the hypotensive effects of tilisolol and cromakalim were antagonized, while that of propranolol was not affected. These results suggest that the vasorelaxant and hypotensive actions of tilisolol involve an opening of K+ channels which can be inhibited by glibenclamide and may also involve additional relaxant mechanisms of action independent of K+ channel opening.

Adrenergic beta-Antagonists↗
PubMed1991

Effects of activation of the divergent efferent fibers on the spontaneous activity of vestibular afferent fibers in the toad.

In anesthetized toads, spontaneous activities were recorded from single afferent fibers of three semicircular canals and three otolith organs. Since some efferent fibers ramify within the eighth nerve and innervate two or more vestibular organs, a single branchlet of the eighth nerve was disconnected from its end organ, and was electrically stimulated to activate divergent efferent collaterals leading to other vestibular organs. The stimulation elicited an inhibitory effect on spontaneous activities of about one third of the afferent population, and a facilitatory effect on those of another one third. The remaining one third was unaffected. Whether or not the inhibitory or facilitatory effect was observed in an individual unit seemed to be related to its pattern and its rate of spontaneous activity. Most of the units showing relatively high and regular spontaneous firing were insensitive to the electrical stimulation, and units with a low firing rate and an irregular pattern of activity tended to be affected by the electrical stimulation. The activation of divergent efferent fibers elicited both inhibition and facilitation on the spontaneous afferent activities in all vestibular nerve branchlets, except in the saccular branchlet, where only inhibition was elicited. Electrical stimulation of the central stump of the saccular nerve branchlet, however, could produce both inhibitory and facilitatory effects in other vestibular nerve branchlets.

Afferent Pathways↗
PubMed1991

[Biological significance of nucleolar organizer region-associated proteins (Ag-NOR) in adenomas and carcinomas of the colon].

The biological significance of silver binding nucleolar organizer regions (Ag-NORs) had been evaluated in tissue sections from 21 colonic adenomas (11 mild atypia, 10 moderate atypia), 23 primary adenocarcinomas of the colon (12 intramucosal carcinomas, 11 advanced carcinomas) and 5 control cases, by automatic image analysis. A significant difference in the mean number of Ag-NORs per nucleus was found when adenomas with moderate atypia and carcinomas were compared with adenomas of mild atypia and control cases. The mean Ag-NORs area per 1 Ag-NOR of carcinomas tended to be larger than that of the adenomas and control group. The mean value of form factor in carcinomas showed greater pleomorphism in shape than that of adenomas and control group. The mean quotient of number and area of Ag-NOR (Ag-NOR score) of the carcinomas was highest among the cases examined. These results indicate that evaluation of the mean Ag-NOR numbers is of great value, with regard to the cell proliferation, and that of Ag-NOR score may give the most accurate estimation of biological character in different groups of colonic neoplasia.

Adenocarcinoma↗
PubMed1991

[Hemopurification in the management of ARDS complicating multiple organ failure].

In the field of critical care medicine, it has been claimed that ARDS often develops as a part of multiple organ failure (MOF). Since multi-modality therapy is necessary in the management of MOF, it is also mandatory even in the management of ARDS. Among the various therapeutic approaches for patients with MOF, hemopurification is one of the most effective therapeutic tools. Various hemopurification methods such as hemodialysis, peritoneal dialysis, hemoadsorption, hemofiltration and plasma exchange have been applied in the management of MOR. However, our recent experiences suggest that continuous hemofiltration (CHF) and/or continuous hemodiafiltration (CHDF) are safest, most easily performed and effective hemopurification in the management of ARDS/MOF. The efficacy of hemopurification in the management of ARDS is summarized as follows. 1) Removal of humoral mediators and causative substances of ARDS following insults such as sepsis and trauma. 2) Treatment of pulmonary interstitial permeability edema which has been claimed to be one of the most important pathological conditions in ARDS. 3) Removal of excess water given as carrier in IVH solution and accumulating in the body. 4) Immunomodulation which has also been considered to be necessary in the treatment or prevention of ARDS.

Hemofiltration↗
PubMed1991

Acute promyelocytic leukemia in Crohn's disease. Case report and review of the literature.

A 19-year-old man with a documented 2-year history of Crohn's disease abruptly developed leukopenia and thrombocytopenia. A diagnosis of acute promyelocytic leukemia was established by bone marrow cytology. Chromosomal analysis of bone marrow aspirate revealed aberrations of no. 8 trisomy and translocation between no. 15 and no. 17 [46,XY,t(15q+,17q-)/47,XY,+8,t(15q+,17q-)]. Nine cases of Crohn's disease complicated by leukemia have been reported, including the present one; once again, a relationship between Crohn's disease and leukemia is suggested.

Adult↗
PubMed1990

Mucoepidermoid carcinoma of the thyroid gland.

An extremely rare case of mucoepidermoid carcinoma of the thyroid in a 56-year-old woman is presented. The patient clinically having Hashimoto's thyroiditis was noted a nodule in her neck. The tumor was sited in the midportion of the left lobe of the thyroid, and histologically it showed both squamous features and mucin production. The squamous cells were arranged in solid sheets with horny pearls and the mucous cells tended to line dilated duct-like elements. Ultrastructurally, the epidermoid cells had aggregates of tonofilaments and well-developed desmosomal attachments, and the mucous cells contained numerous mucin granules in their cytoplasm. Immunohistochemical studies revealed that cytokeratin antibodies showed positivity for both the lining cells and squamous cells, whereas carcinoembryonic antigen positivity was found in the lining cells and intraluminal material. The tumor cells were negative for thyroglobulin, calcitonin, vimentin, chromogranin, and neuron-specific enolase. These unusual histologic and immunohistochemical features are suggestive of a tumor related to the so-called "solid cell nest" of the thyroid.

Carcinoembryonic Antigen↗
PubMed1990

Somatotopic organization and columnar structure of vibrissae representation in the rat ventrobasal complex.

The region of vibrissae representation in the ventrobasal complex (VB) of the rat was systematically mapped, based on receptive fields of many single neurons. Results showed that the ventralmost row of vibrissae projected to the rostral part of VB, that the dorsal-most row projected to the caudal part, and that the caudalmost vibrissae of each row projected to the most dorsolateral part of VB and more rostral vibrissae to the more ventromedial part. Further, it was revealed that the clusters of neurons receiving projections from any individual vibrissae formed corresponding columns extending from the anterodorsomedial to the posteroventrolateral direction, and that these columns piled up dorsoventrally and anteroposteriorly, with ventral ones shifted progressively medially. When cross sections of these columns were viewed on an oblique horizontal section of VB, a group of columns corresponding to each row lined up from the dorsolateral to the ventromedial direction with a rostral convexity, which means that the third or fourth vibrissa in each row projected most rostrally in that row. These results confirmed previous physiological mapping studies of vibrissal representation and are in good agreement with anatomical studies on barreloid structure in VB.

Animals↗
PubMed1990

Observations of the sensing and the tectorial membrane in bullfrog amphibian papilla: their possible functional roles.

Three dimensional reconstructions of the amphibian papilla were performed with light microscopic observations, mainly for the sensing membrane (SM). In horizontal sections of the papilla, the anteromedial end of the SM, which makes contact with the massive anterior portion of the tectorial membrane (TM), is several times thicker than the posterolateral end close to the column of the innervating nerves. This gradient of thickness is observed in all the sections from the dorsal portion attached to the TM to the ventral floor of the papilla. The SM connects to the TM in a topological manner; the anteromedial portion of the TM relates to the anterior end of the SM and the anterolateral and the middle portions of the TM correspond to the sites shifting posteriorly on the SM. The morphology of the SM and its manner of connection to the TM suggest that the SM plays important roles in the occurrence of frequency selectivity and of tonotopic organization of the amphibian papilla.

Animals↗