Background: Radiation doses associated with the conventional dental radiographies are relatively low, but their number is high. Therefore, justification is necessary to ensure that radiation doses to patients, particularly children, are kept as low as reasonably achievable. Materials and Methods: The exposure factors applied for real patients in four age groups (5, 10, 15-year-old and adult) we...

Introduction: Developmental changes in atrioventricular nodal conduction time and refractoriness have been shown in several studies. Prevalence of atrioventricular nodal reentrant tachycardia (AVNRT) is clearly age-dependent. The purpose of this study was to determine developmental changes of basic and frequency-dependent electrophysiological properties of the atrioventricular node (AV-node)...

Myogenic factor mRNA expression was examined during muscle regeneration after bupivacaine injection in Fischer 344/Brown Norway F1 rats aged 3, 18, and 31 mo of age (young, adult, and old, respectively). Mass of the tibialis anterior muscle in the young rats had recovered to control values by 21 days postbupivacaine injection but in adult and old rats remained 40% less than that of contralatera...

OBJECTIVES The loss of effectiveness of ischaemic preconditioning in protecting old hearts from ischaemia/reperfusion damage is thought to be due to low sirtuin 1 levels in old hearts. We sought to determine whether resveratrol (RES), an activator of sirtuin 1, would restore this protection to that seen with ischaemic preconditioning in young hearts. METHODS A Langendorff heart perfusion mode...

The emergence of new, more pathogenic viruses necessitates elucidation of factors that promote viral evolution. Aging, a potential factor, is associated with increased susceptibility to viral infections. We used the enterovirus coxsackievirus B3 (CVB3) to investigate the effects of host age on pathogenicity and viral gene sequence. Old mice infected with a normally amyocarditic strain of CVB3, ...

Bilateral common carotid artery stenosis (BCAS) models the effects of compromised cerebral blood flow on brain structure and function in mice. We compared the effects of BCAS in aged (21 month) and young adult (3 month) female mice, anticipating a differentially more severe effect in the older mice. Four weeks after surgery there was a significant age by time by treatment interaction on the rad...

objective(s):some pathologic situations such as diabetes and metabolic syndrome are associated with alternation in nitric oxide level. incidence of these condition increases with aging. on the other hand, insulin secretion is modulated by nitric oxide, and nitric oxide synthase (nos) activity is also altered in diabetes. in this study, modification in the enzyme activity associated with aging a...

Precocious Puberty in a 2-year-old boy  A 2-year-old boy with precocious isosexual matura- (3) Lion is reported.  The pubertal values of serum LH, FSH and Testoste- (4) on and lack of any other pathologic finding were in favour of diagnosis of idiopathic sexual precocity.  The L.R.F. response test was of the adult pattern. The serum LH, FSH and Testosterone decreased following (5) treatment ...