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Biomedical subjects

Y Fukushi

Publications and source records attributed to Y Fukushi.

At least 109 records · Page 6Linked to original sources

Electrical and mechanical events through activation of muscarinic receptor in the smooth muscle of guinea-pig vas deferens.

Electrical and mechanical responses of the guinea-pig vas deferens to exogenous acetylcholine (ACh) were observed by means of a single sucrose-gap method. ACh at various concentrations evoked a contraction consisting of two components. The initial component seemed to be independent of a depolarization, while the second one was dependent on it. All ACh responses were abolished by Ca removal from the external solution. The results suggest the existence of a pathway by which ACh even at low concentrations causes a Ca influx without potential changes.

Acetylcholine↗

Characterization of sialosylated Lewisx as a new tumor-associated antigen.

A monoclonal antibody CSLEX1 which reacts with sialosyl Lex but not with sialosyl Lea has been produced. The CSLEX1 antigen has a tissue distribution similar to that of Lex, appearing characteristically in the proximal tubules of the kidney and on granulocytes. It is tumor associated in that 14 of 34 (41%) of tumor lines tested reacted with the CSLEX1 antibody, and 50 of 74 (68%) of tumor tissues tested reacted with the antibody. Loss of immunoperoxidase staining of tissues after neuraminidase treatment showed that the antibody is reacting to sialyl derivatives. The antibody reacted in solid-phase radioimmunoassay to sialosyllactofucopentaosyl(III)ceramide and sialosyldifucosylganglioside (6B). These results indicate that the CSLEX1 epitope has the following structure: (formula: see text) This structure had not previously been known to be tumor associated.

Antibodies, Monoclonal↗

A case of ureteral intussusception associated with ureteral polyp.

We report a case of left ureteral intussusception associated with a ureteral polyp. At operation a 7 cm. long polyp was seen originating from the tip of the inside of the proximal ureter, causing 1.7 cm. of antegrade invagination. The polyp was resected and the invaginated region was repaired since pathological examination revealed a benign tumor. At followup an excretory urogram demonstrated prompt improvement of left hydronephrosis.

Female↗

Effects of homopantothenic acid on intestinal smooth muscles.

The effects of homopantothenic acid (HOPA) on intestinal smooth muscles were investigated and compared with those of gamma-aminobutyric acid (GABA). HOPA contracted the rat ileum and produced a biphasic response (relaxation followed by contraction) in the guinea-pig ileum and taenia coli. Half-maximal effects were obtained with 0.3-0.9 nM HOPA and maximal responses with 2-4 nM in the rat and the guinea-pig ileum. In the guinea-pig taenia, half-maximal effects were obtained with 0.2-0.25 microM HOPA and maximal responses with 2-4 microM HOPA. Tachyphylaxis occurred with higher concentrations. All these responses were not significantly affected by tetrodotoxin (TTX), atropine, diphenhydramine or metiamide. The relaxation elicited by HOPA was not reduced by simultaneous application of phentolamine and propranolol. Unlike HOPA, GABA produced a biphasic response (a relaxation followed by a contraction) in the guinea-pig ileum, which was almost abolished by TTX. These results suggest that HOPA mainly acts on intestinal smooth muscle directly, whereas GABA does indirectly through nerves.

Animals↗

Opsonic effect of normal and infected human urine on phagocytosis of Escherichia coli and yeasts by neutrophils.

The opsonic effect of urine from normal adults and patients with acute cystitis on phagocytosis of yeast and E. coli by purified human neutrophils was investigated. Urine with an osmotic pressure between 200 and 500 mOsm./kg. was the most effective as an opsonic buffer in either phagocytosis of yeast or E. coli by PMN. However, those with an osmotic pressure greater than 500 mOsm./kg. or less than 200 mOsm./kg. were rather suppressive to phagocytosis by PMN. Patient's urine exhibited a more potent opsonic effect on phagocytosis of either bacteria when compared with that of normal urine with a similar osmotic pressure. Heat inactivation gave no effect on the potent opsonic activity of patient's urine, suggesting that complement may not be working in these phagocytosis systems or that the test urine may originally contain no complement. However, immunoelectrophoretic survey of test urine and addition of serum proteins into the urine suggest the possibility that certain serum derived urine proteins other than complement may play an opsonic role in phagocytosis by PMN in the patient's urine, although the factors have not been determined.

Complement System Proteins↗

The role of intravesical polymorphonuclear leukocytes in experimental cystitis.

Electron and light microscopic observations were made on experimentally induced cystitis in rats with particular emphasis on the role of polymorphs in the wall of the urinary bladder. Polymorphs appear from the time of invasion of bacteria to the epithelial cells of the bladder, aggregate primarily around infected epithelial cells, which become surrounded and isolated from healthy epithelial cells, and accelerate the desquamation of the infected epithelial cells. In the submucosal layer, all invading bacteria are phagocytized by polymorphs. Although polymorphs found in the intercellular space of the epithelial cells do not show phagocytosis, those that are released into the lumen of the urinary bladder do.

Animals↗

Effect of cyanoacrylate treatment of cavity walls.

Cyanoacrylate treatment of the cavity wall for composite resin restoration failed to keep adhesion when set, but the marginal closure improved markedly both in vivo and vitro, even when thermal-cycled. It irritated the pulp slightly only at the beginning. Ethylcyanoacrylate was superior to methylcyanoacrylate in regard to adhesion, leakage and pulp response.

Adhesives↗

An electron microscopic study of the interaction between vesical epitherlium and E. Coli.

Interaction between rat bladder epithelium and Escherichia coli was observed using the transmission electron microscope. As a first step, the bacterial cell coat attaches to the cell coat of the luminal membrane. Then, the luminal membrane enfolds to envelope the bacterium and take it within the cytoplasm. The unit membranes covering the bacteria are destroyed and some of these bacteria are found to be deformed and probably dead in the cytoplasm. Finally, the superficial epithelial cells invaded by many bacteria are collapsed and desquamated into urine. However, these epithelia show a rather prompt recovery and form the normal three layers within 24 hr after inoculation. This experiment suggests one of the defense mechanisms of the vesical epithelium againts E. coli. It is likely that the onset of clinical cystitis may be prevented by the same mechanism during the occasional bacterial invasion of the bladder.

Animals↗

Neuronal norepinephrine as mediator for ouabain-induced smooth muscle contraction.

With some latency, ouabain (10(-6)--10(-5) M) induced a long-lasting contractile response of the isolated vas deferens of the guinea-pig. The ouabain-induced contraction was potentiated by pretreatment with tropolone, whereas it was prevented by pretreatment with cocaine, bretylium, reserpine or phentolamine. The response was unaffected byatropine, methysergide and tetrodotoxin. Ouabain, perfused into the isolated tissue, enhanced dose-dependently the release of norepinephrine into the medium. However, this enhancement of norepinephrine release was prevented by reserpine or by removal of Ca from the medium. These findings support the hypothesis that the ouabain-induced contraction of vas deferens might be due to norepinephrine released from the adrenergic nerve ending granules through a Ca2+-dependent process.

Animals↗