Hemodynamics in congenital heart disease

This paper introduces a very general and flexible model for the study of hemodynamic changes in congenital heart disease. The generality of the model makes it possible to use the same computer program (which is included in an Appendix) to study both the fetal circulation and the adult circulation, as well as such diverse disease states as patent ductus arteriosus, ventricular septal defect, atrial septal defect, tetralogy of Fallot and transposition of the great arteries. In this paper, only patent ductus and ventricular or atrial septal defect are studied, with special emphasis on the influence of increasing pulmonary vascular resistance on the shunt flow. In the case of patent ductus and ventricular septal defect, the computed shunt flow is very time-dependent and the left-to-right shunt becomes first bidirectional and then right-to-left as the pulmonary resistance increases. By contrast, the computed shunt flow of atrial septal defect is nearly time-independent and is also somewhat less sensitive to the pulmonary vascular resistance.     

Postosteonecrotic osteoarthritis-like disorder of the femoral head of rats

The femoral heads of 15 rats were studied histologically 3 months after the induction of ischaemic necrosis by incising the cervical periosteum and cutting the ligamentum teres. The epiphyses consisted of immature disorganized subchondral and trabecular bone. The inter-trabecular spaces contained fibrous or haematopoietic tissue. Residual necrotic bone was rare. There was marked osteoblastic and osteoclastic activity. The articular aspect of the heads showed a spectrum of changes, ranging from cartilaginous degeneration with fibrillation and loss of glycosaminoglycans to an eburnated and polished bony surface. In seven rats, transphyseal bridges connected the epiphyseal and metaphyseal bony trabeculae to each other. It is suggested that the postnecrotic reparative processes, including the resorption of the necrotic debris and its replacement by newly formed, weak bone, led to an osteoarthritis-like disorder. This healing pattern of the necrotic femoral head was reminiscent of the progressive remodelling that occurs in rings in femoral capital osteonecrosis of adult human patients and in Perthes's disease of children.     

Numerical Simulation and Experimental Validation of Blood Flow in Arteries with Structured-Tree Outflow Conditions

Blood flow in the large systemic arteries is modeled using one-dimensional equations derived from the axisymmetric Navier–Stokes equations for flow in compliant and tapering vessels. The arterial tree is truncated after the first few generations of large arteries with the remaining small arteries and arterioles providing outflow boundary conditions for the large arteries. By modeling the small arteries and arterioles as a structured tree, a semi-analytical approach based on a linearized version of the governing equations can be used to derive an expression for the root impedance of the structured tree in the frequency domain. In the time domain, this provides the proper outflow boundary condition. The structured tree is a binary asymmetric tree in which the radii of the daughter vessels are scaled linearly with the radius of the parent vessel. Blood flow and pressure in the large vessels are computed as functions of time and axial distance within each of the arteries. Comparison between the simulations and magnetic resonance measurements in the ascending aorta and nine peripheral locations in one individual shows excellent agreement between the two. © 2000 Biomedical Engineering Society. PAC00: 8719Uv     

Fifteen years experience with an in-vitro fertilization surrogate gestational pregnancy programme

The purpose of our study was to review and evaluate retrospectively the experience of an in-vitro fertilization (IVF) surrogate gestational programme in a tertiary care and academic centre. In a 15 year period from 1984 to 1999, a total of 180 cycles of IVF surrogate gestational pregnancy was started in 112 couples. On average, the women were 34.4 +/- 4.4 years of age, had 11.1 +/- 0.72 oocytes obtained per retrieval, 7.1 +/- 0.5 oocytes fertilized and 5. 8 +/- 0.4 embryos subsequently cleaved. Sixteen cycles (8.9%) were cancelled due to poor stimulation. Except for six cycles (3.3%) where there were no embryos available, an average of 3.2 +/- 0.1 embryos was transferred to each individual recipient. The overall pregnancy rate per cycle after IVF surrogacy was 24% (38 of 158), with a clinical pregnancy rate of 19% (30 of 158), and a live birth rate of 15.8% (25 of 158). When compared to patients who underwent a hysterectomy, individuals with congenital absence of the uterus had significantly more oocytes retrieved (P < 0.006), fertilized, cleaved and more embryos available for transfer despite being of comparable age. IVF surrogate gestation is an established, yet still controversial, approach to the care of infertile couples. Take-home baby rates are comparable to conventional IVF over the same 15 year span in our programme. Patients with congenital absence of the uterus responded to ovulation induction better than patients who underwent a hysterectomy, perhaps due in part to ovarian compromise from previous surgical procedures.     

Rapid,Full-Scale Change to Virtual PCIT During the COVID-19 Pandemic: Implementation and Clinical Implications

Health agencies call for the immediate mobilization of existing interventions in response to numerous child and family mental health concerns that have arisen as result of the COVID-19 pandemic. Answering this call, this pilot study describes the rapid, full-scale change from a primarily clinic-based Parent–Child Interaction Therapy (PCIT) model to a virtual service model (i.e., I-PCIT) in an academic and community-based program in Miami, Florida. First, we describe the virtual service training model our program developed and its implementation with 17 therapists (M_Age?=?32.35, 88.2% female, 47.1% Hispanic) to enable our clinic to shift from providing virtual services to a small portion of the families served (29.1%) to all of the families served. Second, we examine the effect of I-PCIT on child and caregiver outcomes during the 2-month stay-at-home period between March 16, 2020, and May 16, 2020, in 86 families (M_ChildAge?=?4.75, 71% Hispanic). Due to the rapid nature of the current study, all active participants were transferred to virtual services, and therefore there was no comparison or control group, and outcomes represent the most recently available scores and not treatment completion. Results reveal that I-PCIT reduced child externalizing and internalizing problems and caregiver stress, and increased parenting skills and child compliance with medium to large effects even in the midst of the COVID-19 pandemic. Finally, the study examined components of our virtual service training model associated with the greatest improvements in child and caregiver outcomes. Preliminary findings revealed that locally and collaboratively developed strategies (e.g., online communities of practice, training videos and guides) had the strongest association with child and caregiver outcomes. Implications for virtual service delivery, implementation, and practice in the midst of the COVID-19 pandemic are discussed.

     

Soft Drink Consumption and Mental Health in Adolescents: A Longitudinal Examination

PurposePrevious studies showed associations between soft drink consumption and mental health problems in adolescents, but the direction of these effects is unknown. This study examines the hypotheses that soft drink consumption predicts aggression and depressive symptoms over time and that these mental health problems predict soft drink consumption.MethodsInterviews were conducted with 5,147 children and their caregivers from three sites at child ages 11, 13, and 16. At each time point, youth reported on their frequency of consuming soft drinks, aggressive behavior, and depressive symptoms. An autoregressive cross-lagged path model tested reciprocal relationships between soft drink consumption, aggressive behavior, and depressive symptoms over time.ResultsMore frequent consumption of soft drinks was associated with more aggressive behavior at each time point and depressive symptoms at ages 11 and 13 (r = .04 to .18, p ≤ .002). After adjusting for covariates and stability of each behavior over time, soft drink consumption at ages 11 and 13 predicted more aggressive behavior at the next time point (β = .08 and .06, p < .001). Aggressive behavior at age 13 also predicted more soft drink consumption at age 16 (β = .06, p = .002). Soft drink consumption at age 13 predicted fewer depressive symptoms (β = ?.04, p = .007), but depressive symptoms did not predict soft drink consumption.ConclusionsMore frequent consumption of soft drinks may contribute to aggressive behavior in adolescents over time; there is some support for reciprocal relationships. There is no evidence for soft drink consumption contributing to adolescents' depression. Future research should examine longitudinal effects over shorter intervals.     

Mathematical modeling of the impact of recirculation on exchange kinetics in tandem extracorporeal membrane oxygenation and therapeutic plasma exchange

Vascular access connection configurations during tandem extracorporeal membrane oxygenation (ECMO) and therapeutic plasma exchange (TPE) may impact exchange kinetics. In these tandem procedures, typically the TPE inlet line is proximal to the TPE return line with respect to blood flow in the ECMO device, maximizing the opportunity for replacement fluid homogenization within the ECMO circuit. However, if TPE inlet and return line connections are switched, recirculation—a phenomenon in which replacement fluid leaving the TPE return line is prematurely drawn into the TPE inlet line prior to satisfactory homogenization within the ECMO circuit—will occur. Such recirculation could diminish TPE efficacy in patients on ECMO and mitigate therapeutic benefits. Using a mathematical model of recirculation in tandem ECMO and TPE, we demonstrate that the predicted impact of recirculation is negligible and vascular access connection positioning does not appear to be a point of clinical concern with regard to TPE kinetics.     

Supersymmetric dark matter in the harsh light of the Large Hadron Collider

I review the status of the model of dark matter as the neutralino of supersymmetry in the light of constraints on supersymmetry given by the 7- to 8-TeV data from the Large Hadron Collider (LHC).     

Effects of the It’s Your Game . . . Keep It Real Program on Dating Violence in Ethnic-Minority Middle School Youths: A Group Randomized Trial

Objectives. We examined whether It’s Your Game . . . Keep It Real (IYG) reduced dating violence among ethnic-minority middle school youths, a population at high risk for dating violence.Methods. We analyzed data from 766 predominantly ethnic-minority students from 10 middle schools in southeast Texas in 2004 for a group randomized trial of IYG. We estimated logistic regression models, and the primary outcome was emotional and physical dating violence perpetration and victimization by ninth grade.Results. Control students had significantly higher odds of physical dating violence victimization (adjusted odds ratio [AOR] = 1.52; 95% confidence interval [CI] = 1.20, 1.92), emotional dating violence victimization (AOR = 1.74; 95% CI = 1.36, 2.24), and emotional dating violence perpetration (AOR = 1.58; 95% CI = 1.11, 2.26) than did intervention students. The odds of physical dating violence perpetration were not significantly different between the 2 groups. Program effects varied by gender and race/ethnicity.Conclusions. IYG significantly reduced 3 of 4 dating violence outcomes among ethnic-minority middle school youths. Although further study is warranted to determine if IYG should be widely disseminated to prevent dating violence, it is one of only a handful of school-based programs that are effective in reducing adolescent dating violence behavior.Adolescent dating violence is a serious public health concern in the United States. National estimates indicate that almost 10% of high school youths (9th–12th graders) are victims of physical dating violence,1 and more than 20% are victims of emotional dating violence.2 In addition to being associated with many negative health outcomes (i.e., substance abuse, suicide, depression, and sexual activity),3–8 adolescent dating violence may be predictive of intimate partner violence in adulthood,8–10 which has exceedingly high economic costs (particularly those related to health care).11 Thus, preventing adolescent dating violence may not only protect youths from severe health consequences, but also reduce the short- and long-term health costs associated with this type of violence.Although most research on adolescent dating violence focuses on high school youths, recent studies indicate that adolescent dating violence begins in middle school.12–14 For example, in a survey of seventh graders from diverse geographic locations, 37% reported being victims of psychological dating violence, and 15% reported being victims of physical dating violence in the last 6 months.14 Furthermore, there is mounting evidence that dating violence disproportionately affects ethnic-minority middle school youths. For instance, in a sample of multiethnic sixth graders from 4 US states, approximately one third of Hispanics and African Americans with a history of dating each reported physical dating violence perpetration, compared with only 14% of Whites.15 A similar racial/ethnic pattern emerged for physical dating violence victimization. Thus, it is becoming increasingly evident that dating violence is prevalent among middle school youths, especially among those who belong to ethnic-minority groups.Adolescent dating violence prevention programs are available, but only a few have been rigorously evaluated. Of these, only 2 school-based programs—Safe Dates and Fourth R: Skills for Youth Relationships (Fourth R)—have been shown to produce significant behavioral effects: both reduced dating violence perpetration or victimization.16–18 However, these programs may not be as effective in ethnic-minority middle school youths because they were developed for and evaluated in older, predominantly White youths. Of the relatively fewer dating violence programs developed for and evaluated in ethnic-minority youths, most have been shown to produce either no19 or inconsistent20 behavioral effects, or have been limited by a weak study design (i.e., lack of control group).21,22 Thus, there is a need for rigorously evaluated, effective dating violence prevention programs16 that specifically target younger, ethnic-minority youths.It’s Your Game…Keep It Real (IYG) is a health education program designed to delay sexual behavior and promote healthy dating relationships in ethnic-minority middle school youths. It is based on the premise that healthy relationships are foundational to healthy adolescent sexual health. In 2 previous randomized controlled trials, IYG was shown to be effective in delaying sexual initiation and reducing other sexual risk behaviors.23,24 An additional research question was whether IYG had an impact on emotional and physical dating violence perpetration and victimization. Thus, our goal was to determine if IYG reduces dating violence behavior among ethnic-minority middle school youths. We hypothesized that, by ninth grade, students who did not receive IYG would report more physical and emotional dating violence perpetration and victimization than students who did receive IYG.