Sex differences in the intensity of cross-sensitization between methylphenidate and amphetamine in adolescent rats.

Chronic use of psychostimulants such as methylphenidate (MPD) and amphetamine (Amph) leads to abuse and dependence. Cross-sensitization occurs when exposure to a drug causes a significant intensified response to a different drug as compared to the effect of the drug in subjects with no previous exposure. Cross-sensitization is used as an experimental correlate for a drug's potential to elicit dependence. The present study uses male and female adolescent rats to examine whether cross-sensitization occurs with MPD, a drug not traditionally considered to elicit dependence, and Amph, a drug considered to elicit dependence. The results showed that there is cross-sensitization with MPD to Amph in adolescent rats and that there is a significant difference in male and female responses. Cross-sensitization between MPD and Amph was observed in a linear dose dependent manner in males and in an inverted U-shape pattern in females. Males treated with the highest dose of 10.0 mg/kg MPD and females treated with the mid-dose of 2.5 mg/kg MPD showed the most robust cross-sensitization. Overall, adolescent female rodents had a greater intensity of response to MPD, Amph, and cross-sensitization between MPD and Amph. This study shows that there are significant sex differences in psychostimulant cross-sensitization in adolescence, indicating the maturity of the gonadal system is not the predominant reason for differences between male and female responses to psychostimulant drugs.

Kommerell's Diverticulum With a Twist: A Case of Recurrent Wheeze in an 8-Year-Old Boy.

Kommerell's diverticulum is a rare, congenital aortic arch anomaly, usually associated with other vascular abnormalities. When present with a concurrent right-sided aortic arch and an aberrant subclavian artery, this triad can form a vascular ring that encompasses the trachea and esophagus. This anatomical variant is usually asymptomatic but can present with respiratory symptoms due to compression of the trachea. In this report, we discuss a case of a Kommerell's diverticulum, which presented as frequent and recurring asthma exacerbations in a pediatric patient.