Biomedical subjects

H Sano

Publications and source records attributed to H Sano.

741 records · Page 42Linked to original sources

PubMedDate not supplied

Ambulatory blood pressure and heart rate during once-daily, randomized, crossover administration of carteolol and atenolol.

This study evaluated the effect of beta-adrenoceptor blocking agents (beta-blockers) with or without intrinsic sympathomimetic activity on the 24-hour blood pressure profile of 15 untreated patients with essential hypertension. After a 4-week run-in period, subjects were randomly assigned to an 8-week treatment period of once-daily carteolol (15 mg/d) or atenolol (50 mg/d). The groups were crossed over at week 8. Office blood pressure and heart rate were recorded every 2 weeks and 24-hour ambulatory blood pressure monitoring was performed immediately preceding and at the conclusion of each period. Both drugs significantly reduced (P < 0.01) office blood pressure and heart rate throughout the two treatment periods. The 24-hour ambulatory blood pressure monitoring at 0.5- and 1-hour intervals revealed that systolic blood pressure in 2 of 8 sleeping hours and diastolic blood pressure in 4 of 8 sleeping hours were significantly higher (P < 0.05) after carteolol treatment than after atenolol treatment. The average values for both daytime and nighttime blood pressures, however, were significantly lower at the end of both periods. Although atenolol lowered heart rate throughout the 24-hour period, there was a smaller reduction in heart rate with carteolol than with atenolol during daytime (-5.4 +/- 4.9 beats/min vs -12.7 +/- 6.6 beats/min, P < 0.005, respectively). Heart rate increased during nighttime (P < 0.02) and was significantly greater than with atenolol treatment (5.0 +/- 7.2 beats/min vs -5.7 +/- 8.0 beats/min, P < 0.001, respectively). These results suggest that the different effects of the two beta-blockers on heart rate and nighttime blood pressure may be attributed to the presence or absence of intrinsic sympathomimetic activity.

Adult↗

PubMedDate not supplied

Nanoleakage: leakage within the hybrid layer.

Most microleakage studies involve quantitating the magnitude of movement of a tracer molecule through a gap between restorative materials and the wall of cavity preparations. The present microscopic study examined the migration of silver nitrate into the interface between dentin and five different dentin bonding agents used to restore class 5 cavities, in the absence of gap formation. Several different leakage patterns were seen, but they all indicated leakage within the hybrid layer when viewed by SEM. The ranking of microleakage from most to least was: All-Bond 2 > Suberbond C&B > Scotchbond Multi-Purpose > Clearfil Liner Bond System > Kuraray Experimental System, KB-200. To distinguish this special type of microleakage within the basal, porous region of the hybrid layer in the absence of gap formation, we propose the term nanoleakage.

Analysis of Variance↗

PubMedDate not supplied

Comparative SEM and TEM observations of nanoleakage within the hybrid layer.

Most adhesive interface studies have involved SEM demonstration of the penetration of adhesive resins into demineralized dentin surfaces with subsequent creation of hybrid layers. Nanoleakage is a term that describes the diffusion of small ions or molecules within the hybrid layer in the absence of gap formation. The present microscopic study examined the nanoleakage of the hybrid layer using a silver nitrate staining technique. Adhesive dentin sandwiches, which were immersed in a silver nitrate solution, were prepared for both SEM and TEM examination using both the Clearfil Liner Bond and All-Bond 2 adhesive systems. Both systems demonstrated silver accumulation within the hybrid layers. Clearfil Liner Bond System showed scattered silver particles at the bottom two-thirds of the hybrid layer by both SEM and TEM observation, whereas All-Bond 2 revealed stained fiber-like structures within the full thickness of the hybrid layer. To evaluate the quality of the hybrid layer, the utilization of tracer molecules such as silver nitrate that are detectable by both SEM and TEM is proposed. It is important to determine the location and morphology of these nanometer-sized porosities that may permit the hydrolysis of collagen fibers and degradation of adhesive monomers.

Collagen↗