Biomedical subjects

S Kihara

Publications and source records attributed to S Kihara.

131 records · Page 8Linked to original sources

PubMedDate not supplied

Protective effect of JTV519, a new 1,4-benzothiazepine derivative, on prolonged myocardial preservation.

BACKGROUND: JTV519 is know to protect cardiomyocytes from calcium overloading-induced damage. The aim of this study was to investigate the potential protective effect of JTV519 on myocardium subjected to prolonged ischemia and the underlying mechanism of such protection. The effect of JTV519 was also compared with that of diltiazem, a 1,5-benzothiazepine derivative. METHODS: Isolated rat hearts were randomly divided into three groups. Control hearts were arrested with histidine-tryptophan-ketoglutarat (HTK) cardioplegic solution alone. In the JTV519 group of hearts, cardiac arrest was achieved with JTV519 (10(-3) mmol/L) in the HTK solution. Hearts in the diltiazem group were arrested with diltiazem (0.5 mmol/L) in the HTK solution. All the hearts were then subjected to 6-hour storage in HTK solution at 4 degrees C. RESULTS: After a 30-minute reperfusion, the left ventricular developed pressure in the JTV519 and diltiazem groups were improved significantly compared with the control group. There was a significantly lower left ventricular end-diastolic pressure level and higher recovery of coronary flow in the JTV519 group than in the control group. The postischemic intracellular calcium concentration was attenuated by adding JTV519 or diltiazem to HTK cardioplegia. CONCLUSION: As an adjunct to cardioplegia, JTV519 showed a significant protective effect on myocardium undergoing 6 hours of ischemia. The beneficial protective effects of JTV519 are correlated with its ability to inhibit the postischemic rise in intracellular calcium.

Animals↗

PubMedDate not supplied

Novel modulator for endothelial adhesion molecules: adipocyte-derived plasma protein adiponectin.

BACKGROUND: Among the many adipocyte-derived endocrine factors, we recently found an adipocyte-specific secretory protein, adiponectin, which was decreased in obesity. Although obesity is associated with increased cardiovascular mortality and morbidity, the molecular basis for the link between obesity and vascular disease has not been fully clarified. The present study investigated whether adiponectin could modulate endothelial function and relate to coronary disease. METHODS AND RESULTS: For the in vitro study, human aortic endothelial cells (HAECs) were preincubated for 18 hours with the indicated amount of adiponectin, then exposed to tumor necrosis factor-alpha (TNF-alpha) (10 U/mL) or vehicle for the times indicated. The adhesion of human monocytic cell line THP-1 cells to HAECs was determined by adhesion assay. The surface expression of vascular cell adhesion molecule-1 (VCAM-1), endothelial-leukocyte adhesion molecule-1 (E-selectin), and intracellular adhesion molecule-1 (ICAM-1) was measured by cell ELISA. Physiological concentrations of adiponectin dose-dependently inhibited TNF-alpha-induced THP-1 adhesion and expression of VCAM-1, E-selectin, and ICAM-1 on HAECs. For the in vivo study, the concentrations of adiponectin in human plasma were determined by a sandwich ELISA system that we recently developed. Plasma adiponectin concentrations were significantly lower in patients with coronary artery disease than those in age- and body mass index-adjusted control subjects. CONCLUSIONS: These observations suggest that adiponectin modulates endothelial inflammatory response and that the measurement of plasma adiponectin levels may be helpful in assessment of CAD risk.

Adipocytes↗

PubMedDate not supplied

Effects of Staphylococcus aureus on the ciliary activity of the middle ear lining.

Our previous investigation using normal guinea pigs disclosed that, like respiratory mucosa, the middle ear lining has ciliary activity, and that this ciliary activity becomes more active as the location becomes more distal to the eustachian tube. In this experimental study, the effects of Staphylococcus aureus on the middle ear lining was examined from functional and morphological viewpoints. In conclusion, the ciliary activity at the entrance to the eustachian tube and that more distal to the tube present a similar pattern of reaction to S aureus in an in vitro system. On the other hand, the ciliary activity of the middle ear lining displays a varying pattern of reaction according to the locations within the tympanic cavity.

Animals↗

PubMedDate not supplied

House dust mite-specific IgE, IgG1, and IgG4 antibodies in patients with perennial rhinitis.

Serum samples were obtained from patients with house dust mite-sensitive nasal allergies before and 6 months after immunotherapy, and the level of immunoglobulin (Ig)E, IgG1, and IgG4 antibodies in those sera was determined by the enzyme-linked immunosorbent assay. The present data showed that the mite-specific IgG4 antibodies increased in patients who responded well to immunotherapy but not in those who responded poorly. It was suggested from the present study that IgG4 antibodies seem to act as "blocking antibodies" to reduce the allergic reaction in the target organ, and that an increase of allergen-specific IgG4 antibodies following immunotherapy can be of clinical benefit to patients suffering from mite-specific nasal allergy.

Dust↗

PubMedDate not supplied

Ciliary activity of the middle ear lining in guinea pigs.

Since the middle ear lining is an extension and a modification of the respiratory epithelium, it is conceivable that it has a mucociliary system and plays an important role in clearing the middle ear cavity. It has already been noted in morphological investigations that the middle ear mucosa has ciliated cells. To our knowledge, however, ciliary activity has never been observed directly. In our research, we used the photoelectric method to study ciliary activity of the middle ear mucosa directly and quantitatively. We made special reference to the frequency of ciliary beating at various sites within the middle ear cavity. Ciliary activity was found to exist in the eustachian tube and the middle ear, the same as in other respiratory organs, and this activity was stronger in cells distal to the eustachian tube.

Animals↗