A Randomized Clinical Trial of Vapocoolant for Pediatric Immunization Pain Relief

OBJECTIVES: The purpose of the current study was to evaluate the effectiveness of vapocoolant for preschoolers’ immunization injection pain relief. STUDY DESIGN: 57 4- to 6-year-old children were randomized to vapocoolant alone or typical care conditions. Pain was measured at baseline and at injection via self-report, caregiver-report, nurse-report, and an observational scale. RESULTS: Self-report suggested that children in the vapocoolant alone condition demonstrated stronger increases in pain from baseline to injection than typical care. All other measures showed significant increases in pain from baseline to injection, but none indicted treatment effects. CONCLUSIONS: Consistent with prior studies, vapocoolant might not be an effective pain-management intervention for children’s intramuscular injections

Randomized Clinical Trial of Distraction for Infant Immunization Pain

Distraction has been shown to be an effective technique for managing pain in children; however, few investigations have examined the utility of this technique with infants. The goal of the current study was to investigate the effectiveness of movie distraction in reducing infants’ immunization distress. Participants were 136 infants (range = 1 to 21 months; M = 7.6 months, SD = 5.0 months) and their parents, all of whom were recruited when presenting for routine vaccinations. The parent-child dyads were randomly assigned to either a Distraction or Typical Care control condition. Infant and adult behaviors were assessed using a visual analog scale and a behavioral observation rating scale. Results indicated parents in the Distraction group engaged in higher rates of distraction than those in the Typical Care group, whereas there was no difference in the behavior of nurses in the Distraction and Typical Care groups. In addition, infants in the Distraction group displayed fewer distress behaviors than infants in the Typical Care group both prior to and during recovery from the injection. Findings suggest that a simple and practical distraction intervention can provide some distress relief to infants during routine injections

Does Respondent Driven Sampling Alter the Social Network Composition and Health-Seeking Behaviors of Illicit Drug Users Followed Prospectively?

Respondent driven sampling (RDS) was originally developed to sample and provide peer education to injection drug users at risk for HIV. Based on the premise that drug users' social networks were maintained through sharing rituals, this peer-driven approach to disseminate educational information and reduce risk behaviors capitalizes and expands upon the norms that sustain these relationships. Compared with traditional outreach interventions, peer-driven interventions produce greater reductions in HIV risk behaviors and adoption of safer behaviors over time, however, control and intervention groups are not similarly recruited. As peer-recruitment may alter risk networks and individual risk behaviors over time, such comparison studies are unable to isolate the effect of a peer-delivered intervention. This analysis examines whether RDS recruitment (without an intervention) is associated with changes in health-seeking behaviors and network composition over 6 months. New York City drug users (N = 618) were recruited using targeted street outreach (TSO) and RDS (2006–2009). 329 non-injectors (RDS = 237; TSO = 92) completed baseline and 6-month surveys ascertaining demographic, drug use, and network characteristics. Chi-square and t-tests compared RDS- and TSO-recruited participants on changes in HIV testing and drug treatment utilization and in the proportion of drug using, sex, incarcerated and social support networks over the follow-up period. The sample was 66% male, 24% Hispanic, 69% black, 62% homeless, and the median age was 35. At baseline, the median network size was 3, 86% used crack, 70% used cocaine, 40% used heroin, and in the past 6 months 72% were tested for HIV and 46% were enrolled in drug treatment. There were no significant differences by recruitment strategy with respect to changes in health-seeking behaviors or network composition over 6 months. These findings suggest no association between RDS recruitment and changes in network composition or HIV risk, which supports prior findings from prospective HIV behavioral surveillance and intervention studies

Hepatic stellate cells require a stiff environment for myofibroblastic differentiation

The myofibroblastic differentiation of hepatic stellate cells (HSC) is a critical event in liver fibrosis and is part of the final common pathway to cirrhosis in chronic liver disease from all causes. The molecular mechanisms driving HSC differentiation are not fully understood. Because macroscopic tissue stiffening is a feature of fibrotic disease, we hypothesized that mechanical properties of the underlying matrix are a principal determinant of HSC activation. Primary rat HSC were cultured on inert polyacrylamide supports of variable but precisely defined shear modulus (stiffness) coated with different extracellular matrix proteins or poly-l-lysine. HSC differentiation was determined by cell morphology, immunofluorescence staining, and gene expression. HSC became progressively myofibroblastic as substrate stiffness increased on all coating matrices, including Matrigel. The degree rather than speed of HSC activation correlated with substrate stiffness, with cells cultured on supports of intermediate stiffness adopting stable intermediate phenotypes. Quiescent cells on soft supports were able to undergo myofibroblastic differentiation with exposure to stiff supports. Stiffness-dependent differentiation required adhesion to matrix proteins and the generation of mechanical tension. Transforming growth factor-β treatment enhanced differentiation on stiff supports, but was not required. HSC differentiate to myofibroblasts in vitro primarily as a function of the physical rather than the chemical properties of the substrate. HSC require a mechanically stiff substrate, with adhesion to matrix proteins and the generation of mechanical tension, to differentiate. These findings suggest that alterations in liver stiffness are a key factor driving the progression of fibrosis