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Biomedical subjects

James Snyder

Publications and source records attributed to James Snyder.

16 recordsLinked to original sources
PubMed2006

The role of behavior observation in measurement systems for randomized prevention trials.

The role of behavior observation in theory-driven prevention intervention trials is examined. A model is presented to guide choice of strategies for the measurement of five core elements in theoretically informed, randomized prevention trials: (1) training intervention agents, (2) delivery of key intervention conditions by intervention agents, (3) responses of clients to intervention conditions, (4) short-term risk reduction in targeted client behaviors, and (5) long-term change in client adjustment. It is argued that the social processes typically thought to mediate interventionist training (Element 1) and the efficacy of psychosocial interventions (Elements 2 and 3) may be powerfully captured by behavior observation. It is also argued that behavior observation has advantages in the measurement of short-term change (Element 4) engendered by intervention, including sensitivity to behavior change and blinding to intervention status.

Child↗
PubMed2006

Modeling heterogeneity in social interaction processes using multilevel survival analysis.

More than 15 years ago, survival or hazard regression analyses were introduced to psychology (W. Gardner & W. A. Griffin, 1989; W. A. Griffin & W. Gardner, 1989) as powerful methodological tools for studying real time social interaction processes among dyads. Almost no additional published applications have appeared, although such data are commonly collected and the applicable questions are central to many important theoretical perspectives. To revisit the basic methods, the authors use an example from emotion regulation theory in which the level of child antisocial behavior is hypothesized to be positively associated with the hazard rate of angry emotions and negatively associated with sad, fearful emotions in the face of parental negative behavior (scolding). The authors discuss the limitations of traditional approaches to the analysis of social interaction and demonstrate improvements in the ability to model individual differences now available in existing software.

Antisocial Personality Disorder↗
PubMed2005

Immunogenetic factors in beryllium sensitization and chronic beryllium disease.

Exposure to beryllium in the workplace can cause beryllium sensitization and chronic beryllium disease. Sensitization to beryllium can be detected in the laboratory using the beryllium lymphocyte proliferation test. It was shown that anti-HLA antibodies could block the beryllium-specific response in the beryllium lymphocyte proliferation test, thereby implicating HLA genes in chronic beryllium disease. A supratypic genetic marker, HLA-DPB1*E69, was found to be strongly associated with immunologic sensitization to beryllium and chronic beryllium disease in beryllium workers. However, there are 40 HLA-DPB1 gene variants that have E69 but that also have other DNA sequence variations. The purpose of the study was to evaluate the evidence for potential differential susceptibility that may be associated with the physical characteristics of HLA protein molecules for which different HLA-DPB1*E69 variants code; that is, do some HLA-DPB1*E69 variants convey higher risk of beryllium sensitization and chronic beryllium disease than others. To do this, two approaches were pursued: first, detailed analysis of the findings from the published literature was performed, and second, computational chemistry was used to seek clues concerning the physical properties of the HLA protein molecules for which these alleles code. Among the 40 HLA-DPB1 gene variants that code for E69, molecular epidemiological studies have suggested a risk hierarchy, where some variants appear to convey low to moderate risk of chronic beryllium disease (e.g., HLA-DPB1*0201, approximately 3-fold increased risk), some convey an intermediate risk (e.g., HLA-DPB1*1901, approximately 5-fold) and others convey high risk (e.g., HLA-DPB1*1701, >10-fold). Molecular modeling has been used to further investigate a potential mechanistic basis for these observations. We found a strong correlation between the hierarchical order of risk of chronic beryllium disease associated with specific alleles and the predicted surface electrostatic potential and charge of the corresponding isotypes. Therefore, when alleles were grouped by the relative negative charge on the molecules for which they code, the data suggest that those alleles associated with the most negatively charged proteins carry the greatest risk of beryllium sensitization and disease.

Berylliosis↗
PubMed2005

A randomized trial that compared povidone iodine and chlorhexidine as antiseptics for vaginal hysterectomy.

OBJECTIVE: The purpose of this study was to compare the efficacy of chlorhexidine and povidone iodine for cleansing the operative field for vaginal surgery. STUDY DESIGN: This was a randomized controlled trial that compared 10% povidone iodine and 4% chlorhexidine gluconate as surgical scrubs. Our primary end point was the proportion of contaminated specimens (defined as total bacterial colony counts of >/=5000 colony-forming units) per group found throughout the surgical procedures. All patients received standard infection prophylaxis that included preoperative intravenous antibiotics. Immediately before antibiotic administration and baseline aerobic and anaerobic cultures of the vaginal flora were obtained, which were followed by cultures at 30 minutes after the surgical scrub and hourly thereafter throughout each patient's surgery. RESULTS: A total of 50 patients were enrolled between October 2002 and September 2003. There were no differences between the povidone iodine (n = 27) and chlorhexidine (n = 23) groups with respect to age, race, exogenous hormone use, body mass index, gravity, parity, preoperative mean colony counts, or operative time. Among the first set of intraoperative specimens (which were obtained 30 minutes after the surgical scrub), 63% of the cultures (17/27) from the povidone iodine group and 22% of the cultures (5/23) from the chlorhexidine group were classified as contaminated ( P = .003; relative risk, 6.12; 95% CI, 1.7, 21.6). Subsequent cultures failed to demonstrate significant differences. CONCLUSION: Chlorhexidine gluconate was more effective than povidone iodine in decreasing the bacterial colony counts that were found in the operative field for vaginal hysterectomy.

Adult↗
PubMed2005

Sodium MR imaging of acute and subacute stroke for assessment of tissue viability.

Sodium MR imaging at 3.0 T provides high-quality images in acceptable acquisition times that allow assessment of tissue viability as defined by maintenance of sodium ion homeostasis. This application is made feasible for clinical stroke evaluation by an efficient projection pulse sequence with extremely short echo time values. This twisted projection imaging provides high signal-to-noise images at adequate resolution (5 x 5 x 5 mm(3)) in less than 10 minutes at 3.0 T. The images are quantified as tissue sodium concentration (TSC) maps that can be interpreted directly in terms of tissue viability. With infarction, baseline TSC values of less than 45 mmol/L increase at variable rates to approximately 70 mmol/L, allowing monitoring of the progression of stroke pathophysiology.

Adult↗
PubMed2005

Deviancy training and association with deviant peers in young children: ocurrence and contribution to early-onset conduct problems.

The relationships of deviant talk and role taking during peer interaction, association with deviant peers, and growth in overt and covert conduct problems during kindergarten and first grade were examined in a community sample of 267 boys and girls. At entry to kindergarten, high levels of overt and covert conduct problems predicted association with deviant peers, and deviant peer association predicted deviant talk and role taking during peer interaction during kindergarten. Association with deviant peers, and deviant talk and role taking predicted growth in overt and covert conduct problems on the playground, in the classroom, and at home during kindergarten and first grade. Peer processes associated with growth in conduct problems that escalate rapidly during late childhood and adolescence appear to occur in earlier childhood. These peer processes may play a central role in the evolution of conduct problems to include covert as well as overt forms.

Adult↗
PubMed2005

The contributions of ineffective discipline and parental hostile attributions of child misbehavior to the development of conduct problems at home and school.

Data were collected in a longitudinal study of 134 boys and 132 girls and their families during kindergarten and first grade. Four hours of parent-child interaction were coded to ascertain parent discipline practices. A structured interview assessed maternal attributions about child behavior. Maternal ratings of child conduct problems at kindergarten entry reliably predicted the mother's subsequent hostile attributions concerning child misbehavior and use of ineffective discipline tactics. Ineffective maternal discipline and the interaction of ineffective discipline and hostile attribution predicted growth in child conduct problems at home during kindergarten and first grade. Changes in teacher-reported and observed child conduct problems at school during kindergarten and first grade were predicted by growth in conduct problems at home and by the interaction of ineffective discipline and hostile attribution.

Child↗
PubMed2004

Child impulsiveness-inattention, early peer experiences, and the development of early onset conduct problems.

The conjoint influence of child impulsiveness-inattention (I/I) and peer relationships on growth trajectories of conduct problems was assessed in a community sample of 267 boys and girls. I/I reliably predicted teacher- and parent-reported conduct problems at kindergarten entry and growth in those problems over the next 2 years for boys and girls. The relation of boys' I/I to conduct problems was mediated, in part, by peer rejection and involvement in coercive exchanges with peers. The relation of girls' I/I to conduct problems was less clearly mediated by peer processes, but peer difficulties had additive effects. The impact of peer relationships on trajectories of conduct problems was apparent to parents as well as to teachers. Although I/I increments risk for early and persisting conduct problems in concert with poor peer relationships, it does so in complex and gender-specific ways.

Attention↗
PubMed2004

Rigidity in parent-child interactions and the development of externalizing and internalizing behavior in early childhood.

Behavioral rigidity is a common feature of many psychopathologies, yet the association between rigidity and the development of childhood psychopathology has not been studied. State space grids (a dynamic systems [DS] method) were used to examine the relation between rigidity in parent-child interactions and childhood externalizing and internalizing problems. High-risk kindergarten children (n = 240) and their parents were observed for 2 hr engaging in a variety of tasks that were expected to elicit a range of affect. State space grid analysis of the observational data revealed an association between rigidity in parent-child interactions and child externalizing behavior problems in the fall and spring of kindergarten and 1st grade, and with growth in those problems over time. Rigidity was associated with concurrent levels and with chronic high-level internalizing problems. Strengths and limitations of the new DS methodology in relation to understanding child psychopathology are discussed.

Adult↗
PubMed2004

An introduction to the special issue on advances in process and dynamic system analysis of social interaction and the development of antisocial behavior.

A thorough understanding of how social relationships contribute to child and adolescent trajectories for antisocial behavior may be facilitated by: (a) ascertaining multiple relationship processes (e.g., warmth and reciprocity, coercion and deviancy training); (b) focusing on multiple relationships (e.g., with parents, peers, siblings, and teachers): and (c) assessing relationship processes using increasingly sophisticated measurement and theoretical models (e.g., global ratings and sequential and dynamical systems analyses) of observed microsocial interaction. The reports comprising this special issue, and how they build on and advance previous research efforts, are described from this frame of reference.

Adolescent↗
PubMed2003

The contribution of parents and siblings to antisocial and depressive behavior in adolescents: a double jeopardy coercion model.

A dual coercion model of family processes associated with the development of antisocial and depressive behavior during adolescence was assessed, using an at-risk sample of families and children. Consistent with the model, involvement in family coercion during childhood and adolescence increased both boys' and girls' risk for antisocial behavior in adolescence and girls' risk for depressive behavior. Coercive family processes served as a link between older and younger siblings' antisocial behavior. Childhood exposure to maternal depression predicted boys' and girls' depressive behavior 10 years later, but this association was not mediated by coercion. The data suggest that family risk factors and processes for antisocial development are similar for boys and girls but pathways to depression may be gender specific.

Adolescent↗
PubMed2003

Bacterial colony counts during vaginal surgery.

OBJECTIVE: To describe the bacterial types and colony counts present before and during vaginal surgery. METHODS: A descriptive study was undertaken of patients undergoing vaginal hysterectomy with or without reconstructive pelvic surgery. Aerobic and anaerobic bacterial cultures were obtained immediately before and throughout the surgical cases at preselected time intervals. Standard antimicrobial prophylaxis was administered in all cases. Mean total colony counts and mean anaerobic colony counts were determined by adding all colonies regardless of bacteria type. 'Contamination' was defined as > or = 5000 colony-forming units/ml. RESULTS: A total of 31 patients aged 26 to 82 years (mean age +/- SD, 51 +/- 15) were included. The highest total and anaerobic colony counts were found at the first intraoperative time interval. On the first set of cultures (30 minutes after the surgical scrub), 52% (16/31) of the surgical fields were contaminated, and at 90 minutes, 41% (12/29) were contaminated. A negligible number of subsequent cultures were contaminated. CONCLUSIONS: Any future interventions designed to minimize bacterial colony counts should focus on the first 30 to 90 minutes of surgery.

Adult↗
PubMed2003

Peripartum transmission of penicillin-resistant Streptococcus pneumoniae.

Streptococcus pneumoniae is a rarely recognized cause of neonatal sepsis. We present a recent case of S. pneumoniae bacteremia acquired on the first day of life in a neonate born at 30 weeks of gestation to a mother without prenatal care who had prolonged rupture of the membranes and received intravenous ampicillin prior to delivery. The isolate was resistant to penicillin, with a MIC of the drug of 4 microg/ml. The child responded to a 7-day course of intravenous vancomycin. S. pneumoniae was recovered from the vagina of the mother on a swab culture collected prior to delivery, and isolates from mother and child were confirmed to be identical on the basis of pulsed-field gel electrophoresis. Although neonatal sepsis due to the peripartum transmission of S. pneumoniae is rare, this case highlights the concern that increasing efforts to prevent group B streptococcus neonatal disease may lead to an increase in neonatal infections due to resistant organisms.

Adult↗
PubMedDate not supplied

Observed peer victimization during early elementary school: continuity, growth, and relation to risk for child antisocial and depressive behavior.

The rate at which 266 boys and girls ages 5 to 7 years old were victimized by peers was observed on multiple occasions in kindergarten and first grade. Individual differences in victimization were observed at kindergarten entry and in growth over the subsequent 2 years. Victimization increased for some children but decreased for others. Growth in victimization was reciprocally related to growth in teacher-reported antisocial and depressive behavior for boys. For girls, kindergarten victimization was related to growth in parent-reported antisocial behavior, teacher-reported depressive behavior to growth in victimization, and growth in victimization to parent-reported depression. At a short-term group level, antisocial behavior had a lagged suppressive effect on victimization for boys but a facilitating effect for girls.

Aggression↗
PubMedDate not supplied

The joint contribution of early parental warmth, communication and tracking, and early child conduct problems on monitoring in late childhood.

The relationship of parental warmth, communication, and tracking (WCT), and child conduct problems in early elementary school (age 5.5 years) to monitoring in late elementary school (age 9.5 years) was longitudinally examined in a sample of 267 boys and girls. WCT in kindergarten was associated with lower kindergarten levels and less growth of conduct problems into the first grade, and was prospectively associated with effective monitoring in the third and fourth grades. Overt and covert conduct problems in kindergarten and growth in covert problems during kindergarten and first grade were associated with less effective later monitoring. Early conduct problems mediated the prospective association of WCT on later monitoring. The results are described in a transactional model of parent-child relationships and child problem behavior.

Child↗