Respecting the circle of life: one year outcomes from a randomized controlled comparison of an HIV risk reduction intervention for American Indian adolescents

Potential for widespread transmission of HIV/AIDS among American Indian (AI) adolescents exists, yet no evidence-based interventions (EBIs) have been adapted and evaluated with this population. Intensive psychoeducation may improve knowledge and decision-making which could potentially translate to reductions in HIV risk behaviors. A peer group randomized controlled comparison of an adapted EBI vs. control was delivered over an eight-day summer basketball camp in one reservation-based tribal community to adolescents ages 13–19. Outcome data were gathered immediately post-camp and at 6 and 12 months follow-up. Self-selected peer groups were randomized to intervention (n = 138) or control (n = 129) conditions for a total sample of 267 participants (56.2% female), mean age 15.1 years (SD = 1.7). Intervention participants had better condom use self-efficacy post-camp (Adjusted Mean Difference [AMD] = ?0.75, p < 0.005) and at 6 (AMD = ?0.44, p < 0.005) and 12 months (AMD = ?0.23, p < 0.05) follow-up. Intervention participants also had higher HIV prevention and transmission knowledge (post-camp: AMD = 0.07, p < 0.01; 6 months: AMD = 0.06, p < 0.01) were more likely to believe condoms prevent sexually transmitted infections (post-camp: RR = 1.41, p < 0.005; 6 months: RR = 1.34, p < 0.05), to talk with an adult about HIV/AIDS (post-camp: RR=1.78, p < 0.005; 6 months: RR = 1.14, p < 0.005), had higher partner negotiation efficacy related to substance use during sex (post-camp: AMD = 0.37, p < 0.01), and were more likely to intend to use a condom (post-camp: RR = 1.39, p < 0.01). The adapted intervention had short- and medium-term impacts on AI adolescent risk for HIV/AIDS, but attenuated at 12 months. Intervention delivery through a community-based camp is feasible and acceptable with strong retention. Additional study is needed to evaluate the adapted intervention's impact on sexual risk behaviors and if booster sessions and parent involvement translate to long-term impacts.     

Physiology of cold-stored platelets

Platelet transfusions are a life-saving medical intervention used for the treatment of thrombocytopenia or hemorrhage. Extensive research has gone into trying to understand how to store platelets prior to the transfusion event. Much has been learned about storage bag materials, synthetic solutions, and how temperature impacts platelet viability and function. While room temperature storage of platelets preserves 24-hour in vivo platelet recovery and survival there is a greater risk for bacterial growth. Therefore, cold storage of platelets has become attractive due to the reduction in potential bacterial proliferation and the maintenance of platelet function beyond 5 days of storage. Cold stored platelets, however, have their own set of challenges. Cold stored platelets become activated through several mechanisms. The morphological and molecular changes that occur due to cold exposure enhance their ability to participate in the hemostatic process at the cost of rapid clearance from circulation. This review focuses on the underlying mechanisms leading to cold platelet activation and the receptor modifications involved in platelet clearance.     

Quantification of 5-HT1A and 5-HT2A receptor Binding in Depressed Suicide Attempters and Non-Attempters

Objective: To determine serotonin system abnormalities related to major depression or previous suicidal behavior.

Methods: [¹¹C]WAY100635, [¹⁸F]altanserin and positron emission tomography were used to compare 5-HT_1A and 5-HT_2A binding in MDD patients divided into eight past suicide attempters (>4yrs prior to scanning) and eight lifetime non-attempters, and both groups were compared to eight healthy volunteers.

Results: The two receptor types differed in binding pattern across brain regions from each other, but there were no differences in binding between healthy volunteers and the two depressed groups or between depressed suicide attempters and non-attempters. No effects of depression severity or lifetime aggression were observed for either receptor.

Conclusion: Limitations of this study include small sample size and absence of high lethality suicide attempts in the depressed attempter group. No trait-like binding correlations with past suicide attempt or current depression were observed. Given the heterogeneity of nonfatal suicidal behavior, a larger sample study emphasizing higher lethality suicide attempts may find the serotonin biological phenotype seen in suicide decedents.     

Effect of a patellar realignment brace on patellofemoral relationships: Evaluation with kinematic MR imaging

The effect of a newly developed patellar realignment brace was evaluated in 21 patellofemoral joints (19 patients) with patellar subluxation (13 joints with lateral subluxation and eight with medial subluxation) by using active-movement, loaded kinematic magnetic resonance (MR) imaging. Sixteen patellofemoral joints (76%) demonstrated a qualitative correction of or improvement in patellar subluxation (ie, centralization of the patella or a decrease in the displacement of the patella) after application of the brace. Four of the five “failures” occurred in patellofemoral joints that had patella alta and/or dysplastic bone anatomy. These results indicate that the patellar realignment brace was able to counteract patellar subluxation in the majority of patellofemoral joints studied, as shown by active-movement, loaded kinematic MR imaging. This brace appears to be useful for conservative treatment of patients with patellofemoral joint pain secondary to patellar malalignment and maltracking.     

Physiological pharmacokinetics and pharmacodynamics of (+/-)-verapamil in female rats

Tissue distribution and pharmacodynamics of verapamil were evaluated during steady state intravenous (i.v.) infusion and after single dose intraperitoneal (i.p.) drug administration to female Sprague-Dawley rats. In one group of rats, verapamil was infused to a steady state concentration at which time animals were killed. Verapamil-induced decreases in mean arterial pressure (MAP) were monitored during infusion and correlated with concomitantly obtained plasma verapamil concentrations. Tissue (lung, liver, renal medulla, renal cortex, cardiac muscle, skeletal muscle, perirenal fat, brain stem, cerebral cortex, and cerebellum) and plasma samples were obtained immediately after animals were killed and verapamil and norverapamil concentrations determined. Another group of rats, after receiving i.p. verapamil, were killed at 1, 3, 5, 19, and 24 h. Elimination from each tissue evaluated was described by a first order process. Elimination half-life of verapamil was similar among plasma and tissues evaluated (1.5 to 2.2 h). The per cent verapamil not bound to plasma proteins was concentration-independent and similar between rats receiving i.p. (mean +/- S.D.) (2.28 +/- 0.72 per cent) and i.v. (2.08 +/- 0.03 per cent) verapamil. MAP and verapamil concentration in plasma (r = 0.75; p less than 0.01) and cardiac muscle (r = -0.82; p less than 0.01) were inversely correlated in a highly significant fashion during both i.v. and i.p. drug administrations. The tissue-to-plasma distribution ratio for verapamil and norverapamil was similar among animals receiving i.p. verapamil at all points of sampling, suggesting distribution equilibrium had been achieved. After steady state i.v. infusion, both verapamil and norverapamil tissue: plasma concentration ratios were greater than after i.p. administration. Higher tissue: plasma verapamil concentration ratios after i.v. administration than after i.p. administration suggest either only a pseudoequilibrium is attained after i.p. administration or that determinants of tissue distribution of racemic verapamil differ with different routes of drug administration. In these studies, MAP provided a reasonable pharmacodynamic marker for verapamil tissue and plasma concentrations.