Prospective Associations Between Peer Victimization and Dispositional Mindfulness in Early Adolescence

Peer victimization is associated with several mental health and behavioral problems during childhood and adolescence. Identifying prospective associations between victimization and factors known to protect against these problems may ultimately contribute to more precise developmental models for victimization’s role in behavioral and mental health. This study tested prospective associations between peer victimization and dispositional mindfulness, defined by non-judgmental and accepting awareness of the constant stream of lived experience, during early adolescence. It was hypothesized that victimization would predict lower levels of mindfulness over a 4-month period. Study participants were 152 seventh and eighth grade students (female?=?51%, Caucasian?=?35%, Hispanic/Latino?=?34%, African-American?=?13%, and multi-ethnic or other?=?18%) participating in a social-emotional learning intervention feasibility trial. A structural equation model tested associations between mindfulness, victimization, and covariates at baseline, and mindfulness and victimization at 4-month posttest. As hypothesized, baseline victimization predicted significantly lower levels of mindfulness at 4-month posttest. Baseline mindfulness did not predict victimization. Results may reflect victimized youths’ mindful awareness being recurrently diverted away from the present moment due to thoughts of prior and/or impending victimization. Study implications may include implementing mindful awareness practices as an intervention strategy for victimized youth to enhance and/or restore this promotive factor.     

The “His and Hers” of the Renin-Angiotensin System

Sex differences exist in the regulation of arterial pressure and renal function by the renin-angiotensin system (RAS). This may in part stem from a differential balance in the pressor and depressor arms of the RAS. In males, the ACE/AngII/AT₁R pathways are enhanced, whereas, in females, the balance is shifted towards the ACE2/Ang(1-7)/MasR and AT₂R pathways. Evidence clearly demonstrates that premenopausal women, as compared to aged-matched men, are protected from renal and cardiovascular disease, and this differential balance of the RAS between the sexes likely contributes. With aging, this cardiovascular protection in women is lost and this may be related to loss of estrogen postmenopause but the possible contribution of other sex hormones needs to be further examined. Restoration of these RAS depressor pathways in older women, or up-regulation of these in males, represents a therapeutic target that is worth pursuing.     

Metabolism of deltamethrin and cis- and trans-permethrin by rat and human liver microsomes,liver cytosol and plasma preparations

1. The metabolism of deltamethrin (DLM), cis-permethrin (CPM) and trans-permethrin (TPM) was studied in liver microsomes, liver cytosol and plasma from male Sprague–Dawley rats aged 15, 21 and 90 days and from adult humans.

2. DLM and CPM were metabolised by rat hepatic microsomal cytochrome P450 (CYP) enzymes and to a lesser extent by microsomal and cytosolic carboxylesterase (CES) enzymes, whereas TPM was metabolised to a greater extent by CES enzymes.

3. In human liver, DLM and TPM were mainly metabolised by CES enzymes, whereas CPM was metabolised by CYP and CES enzymes.

4. The metabolism of pyrethroids by cytosolic CES enzymes contributes to the overall hepatic clearance of these compounds.

5. DLM, CPM and TPM were metabolised by rat, but not human, plasma CES enzymes.

6. This study demonstrates that the ability of male rats to metabolise DLM, CPM and TPM by hepatic CYP and CES enzymes and plasma CES enzymes increases with age. In all instances, apparent intrinsic clearance values were lower in 15 than in 90?day old rats. As pyrethroid-induced neurotoxicity is due to the parent compound, these results suggest that DLM, CPM and TPM may be more neurotoxic to juvenile than to adult rats.