Novel Calixarene-Schiff Bases that Bind Silver(I) Ion

Two novel calix[4]arene-Schiff base receptors have been synthesized. One of the new compounds has two pendant aldimines, while the second has been prepared by two-point attachment of a calixarene-dialdehyde onto a calixarene-diamine to form a “calix-tube”. Preliminary binding studies with AgClO4 show large complexation-induced shifts in 1H NMR positions

Motorsports Involvement Among Adolescents and Young Adults with Childhood ADHD

Though children with attention-deficit/hyperactivity disorder (ADHD) are at risk for impulsive, health-endangering behavior, few studies have examined non-substance use-related risk-taking behaviors. This study examined whether adolescents and young adults with ADHD histories were more likely than those without ADHD histories to report frequent engagement in motorsports, a collection of risky driving-related activities associated with elevated rates of physical injury. Path analyses tested whether persistent impulsivity, comorbid conduct disorder or antisocial personality disorder (CD/ASP), and heavy alcohol use mediated this association. Analyses also explored whether frequent motorsporting was associated with unsafe and alcohol-influenced driving

Relative adrenal insufficiency in mice deficient in 5α-reductase 1

Patients with critical illness or hepatic failure exhibit impaired cortisol responses to ACTH, a phenomenon known as ‘relative adrenal insufficiency’. A putative mechanism is that elevated bile acids inhibit inactivation of cortisol in liver by 5α-reductases type 1 and type 2 and 5β-reductase, resulting in compensatory downregulation of the hypothalamic–pituitary–adrenal axis and adrenocortical atrophy. To test the hypothesis that impaired glucocorticoid clearance can cause relative adrenal insufficiency, we investigated the consequences of 5α-reductase type 1 deficiency in mice. In adrenalectomised male mice with targeted disruption of 5α-reductase type 1, clearance of corticosterone was lower after acute or chronic (eightfold, P<0.05) administration, compared with WT control mice. In intact 5α-reductase-deficient male mice, although resting plasma corticosterone levels were maintained, corticosterone responses were impaired after ACTH administration (26% lower, P<0.05), handling stress (2.5-fold lower, P<0.05) and restraint stress (43% lower, P<0.05) compared with WT mice. mRNA levels of Nr3c1 (glucocorticoid receptor), Crh and Avp in pituitary or hypothalamus were altered, consistent with enhanced negative feedback. These findings confirm that impaired peripheral clearance of glucocorticoids can cause ‘relative adrenal insufficiency’ in mice, an observation with important implications for patients with critical illness or hepatic failure, and for patients receiving 5α-reductase inhibitors for prostatic disease

Performance characteristics of upper airway critical collapsing pressure measurements during sleep

Objective: The critical pressure (PCRIT), a measurement of upper airway collapsibility, is a determinant of the severity of upper airway obstruction during sleep. We examined the performance characteristics of the passive and active PCRIT by examining both within-night and between-night variability in the measurements. Methods: We studied 54 sleep apnea patients (39 men, 15 women) and 34 normal subjects (20 men, 14 women) on either 1 or 2 nights during sleep. The PCRIT was measured during relative hypotonia ( passive state) or during periods of sustained upper airway obstruction used to recruit upper airway neuromuscular responses ( active state) within- and between-nights. In a subgroup of 10 normal subjects, we performed repeated measurements during hypnotic-induced sleep. Bland-Altman analyses were used to determine the within-night and between-night reliability of the PCRIT measurements. Results: There were no significant within-night or between-night differences for the mean passive PCRIT. The active PCRIT was ∼1 cm H 2O more collapsible on the second night than on the first night. The limits of agreement, which bound the passive and active PCRIT, was ∼ ± 3 cm H2O and was reduced to ∼ ± 1 cm H 2O for the passive PCRIT with hypnotic-induced sleep. Conclusion: Passive and active PCRIT measurements are reasonably reliable within and between nights. An approximately 3 cm H2O change in passive or active PCRIT appears to represent the minimally significant change in PCRIT necessary to assess the effect of an intervention (e.g., positional therapy, surgical interventions, oral appliance effects, and pharmacotherapy) on upper airway mechanical loads or neuromuscular responses