Elucidating the Impact of Payload Conjugation on the Cell-Penetrating Efficiency of the Endosomal Escape Peptide dfTAT: Implications for Future Designs for CPP-Based Delivery Systems.

Cell-penetrating peptides (CPPs) are promising tools for the intracellular delivery of various biological payloads. However, the impact of payload conjugation on the cell-penetrating activity of CPPs is poorly understood. This study focused on dfTAT, a modified version of the HIV-TAT peptide with enhanced endosomal escape activity, to explore how different payloads affect its cell-penetrating activity. We systematically examined dfTAT conjugated with the SnoopTag/SnoopCatcher pair and found that while smaller payloads such as short peptides do not significantly impair dfTAT's cell delivery activity, larger payloads markedly reduce both its endocytic uptake and endosomal escape efficiency. Our results highlight the role of the payload size and bulk in limiting CPP-mediated delivery. While further research is needed to understand the molecular underpinnings of these effects, our findings pave the way for developing more effective CPP-based delivery systems.

Racial Discrimination Experiences and Friendship Network Dynamics Among Black and Latinx Youth.

Despite a robust volume of evidence documenting adverse effects of racial discrimination experiences on adolescent adjustment outcomes, relatively little is known about the relational consequences of racial discrimination experiences for adolescent friendship networks. To address this gap, this study examines how racial discrimination experiences shape and are shaped by friendship network dynamics in early and middle adolescence. The current study's goals were to explicate whether relational consequences of racial discrimination experiences for friendship network selection differed between interracial and intraracial friendships among Black and Latinx youth, and how these adolescents were influenced by their friends' racial discrimination experiences. Longitudinal social network analysis was used among a sample of predominantly Latinx and Black middle school students from the southwestern U.S. (n = 1034; 50.1% boys, Mage = 12.1, 13.8% White, 18.6% Black, 53.1% Latinx, 14.4% Other race and multiracial). The results showed that Black and Latinx youth preferred intraracial friends. Above and beyond that, Black youth were more likely to have intraracial friendships when the focal individual reported lower levels of general racial discrimination experiences and higher levels of adult-perpetrated racial discrimination experiences. Black and Latinx adolescents reported increases in general racial discrimination experiences over time, as a function of their friends reporting higher levels of racial discrimination (e.g., peer influence). These findings advance developmental research by showing that racial discrimination experiences are consequential for friendship network dynamics by increasing the likelihood of intraracial friend selection among Black youth and through peer influence processes.

Friendship Network Dynamics of Aggressive and Rule-Breaking Antisocial Behaviors in Adolescence.

Growing evidence reveals heterogeneity in antisocial behavior and urges the need to distinguish between aggressive and nonaggressive rule-breaking behaviors. This study characterized how aggression and rule-breaking behaviors shaped peer selection and influence. Using a longitudinal social network modeling approach, these questions were addressed in a sample of 1034 ethno-racially diverse early adolescents (49.52% females, Mage = 12.1), who were assessed in fall and spring of the same year. The results showed no evidence of peer selection on aggressive and rule-breaking behaviors, and significant peer influence on aggressive behavior only. Rule-breaking also forecasted a decreased susceptibility to peer influence on aggressive behavior. The findings expanded our knowledge about complex pathways through which heterogeneity in antisocial behavior is reciprocally related to friendship networks.

Food sources of energy and nutrients among US college students: The Health Starts Here cohort study.

Objective: Identifying the food sources contributing most to total energy percentage, macronutrients, vitamin and mineral consumption among college freshmen, and whether sex played a role. Participants: First-year undergraduate students (N = 269). Methods: Diet was assessed using a DHQ-III and estimated with food source composition tables. Nutrient intakes were expressed as a percentage of total dietary intakes for each food category. Mann-Whitney U tests were used to determine the differences between the two sexes for each food category. Results: A significant proportion of energy and nutrients is contributed by certain food categories, such as grain products, meat, poultry, fish; however, other less desirable sources of energy and nutrient are also identified, including sugary and sports drinks. Among female students, a greater portion of nutritional intakes came from healthier choices. Conclusions: A majority of total energy intake comes from food categories that are energy-dense but also provide essential nutrients.

Making, keeping, and influencing friends: The role of fear of negative evaluation and gender in adolescent networks.

Drawing on a developmental psychopathology perspective and research documenting gender differences in social tasks and structures of friendships, this study uses longitudinal social network analysis (SNA) methods to (a) examine how fear of negative evaluation (FNE) and gender interact to shape friendship dynamics and (b) characterize their distinct roles in how adolescents make new friends, keep existing friends, and become similar to one another over time. Participants were 1,034 sixth through eighth grade students from an ethnically diverse middle school who were assessed in the Fall and Spring of the same academic year. Results showed that girls were more likely to make new friends and maintain existing friendships when they had lower levels of FNE. Conversely, boys were more likely to make new friends and keep existing friends when they had higher levels of FNE. Additionally, girls with low levels of FNE were more likely to maintain friendships with others who also had low FNE levels, whereas boys with high levels of FNE were more likely to maintain friendships with friends who had low levels of FNE. Results also showed significant peer influence effects on FNE such that over time friends became similar to one another on their FNE levels, with no significant gender differences in these processes. The study underscored that FNE appeared to amplify gender differences in how adolescents tend to make and maintain their friendship networks, yet peer influence on FNE levels remained of the same strength for boys and girls. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Preliminary insights into associations between C-reactive protein and social network dynamics.

Recent social psychoneuroimmunology models suggest bidirectional associations between social experiences and the immune system. This work posits that social relationships and networks may influence the functioning of the immune system, but we know little about the role that the immune system plays in how social networks are created and maintained. We examine how salivary C-reactive protein (CRP), as an inflammatory protein, is associated with making new and keeping existing friendship and conflicted relationships among young adult members of a social group. Participants (n = 37; 67.6% female; M age = 18.18 years, 56.81% white/non-Hispanic) provided nominations of friends and individuals with whom they have conflict at wave 1 and two months later at wave 2. At wave 1, in a group setting, participants donated saliva, later assayed for CRP. Stochastic actor-based models revealed that CRP levels were negatively associated with keeping existing friends and positively associated with developing new friendships. We also found that CRP levels were negatively associated with creating new conflicted relationships and predicted an increased likelihood that group members continue conflicted relationships with the focal individual. These preliminary results support the premises of recent social psychoneuroimmunology models by suggesting that inflammation can also serve as a signal to seek new supportive relationships such as friendships and avoid creating new relationships characterized by threat and/or conflict. Findings provide new insights into the theorized function of the immune system for social approach and withdrawal patterns through which our social connections are constructed.

Gender, Maltreatment and Psychiatric Symptoms among Adolescents in Outpatient Substance Abuse Treatment.

Childhood maltreatment experiences are risk factors for externalizing and internalizing symptoms, as well as substance abuse problems during adolescence. In the present study, we administered structured interviews to 394 adolescents receiving outpatient substance abuse treatment services (280 males; M years=16.33; SD years=1.15). K-means cluster analysis was used to examine: (a) the co-patterning of childhood maltreatment experiences and past-year externalizing symptoms (for drug and alcohol abuse and dependence, conduct disorder); (b) between-cluster differences in serious internalizing problems (for past-year anxiety and depression symptoms and current distress); and (c) gender differences in these relations. Both similarities and differences were identified in maltreatment-externalizing behavior patterns and relations with serious internalizing problems across gender groups. Childhood maltreatment and subsequent psychopathology have implications for the adaptation and delivery of substance abuse treatment services to boys and girls to improve their engagement and treatment outcomes.