Evaluating the sensitivity to threat and affiliative reward (STAR) model in relation to the development of conduct problems and callous-unemotional traits across early adolescence

BACKGROUND

The Sensitivity to Threat and Affiliative Reward (STAR) model proposes low threat sensitivity and low affiliation as risk factors for callous-unemotional (CU) traits. Preliminary evidence for the STAR model comes from work in early childhood. However, studies are needed that explore the STAR dimensions in late childhood and adolescence when severe conduct problems (CP) emerge. Moreover, it is unclear how variability across the full spectrum of threat sensitivity and affiliation gives rise to different forms of psychopathology beyond CU traits.

METHODS

The current study addressed these gaps using parent- and child-reported data from three waves and a sub-study of the Adolescent Brain Cognitive Development Study® of 11,878 youth (48% female; ages 9-12).

RESULTS

Consistent with the STAR model, low threat sensitivity and low affiliation were independently related to CU traits across informants and time. Moreover, there was significant interaction between the STAR dimensions, such that children with lower sensitivity to threat and lower affiliation had higher parent-reported CU traits. Unlike CU traits, children with higher threat sensitivity had higher parent-reported CP and anxiety. Finally, children with lower affiliation had higher parent-reported CP, anxiety, and depression. Results largely replicated across informants and time, and sensitivity analysis revealed similar findings in children with and without DSM-5 defined CP.

CONCLUSIONS

Results support the STAR model hypotheses as they pertain to CU traits and delineate threat sensitivity and affiliation as independent transdiagnostic risk factors for different types of psychopathology. Future research is needed to develop fuller and more reliable and valid measures of affiliation and threat sensitivity across multiple assessment modalities.

Genetic versus environmental influences on callous-unemotional traits in preadolescence: The role of parenting and parental psychopathology

Children with callous-unemotional (CU) traits are at risk for severe conduct problems. While CU traits are moderately heritable, parenting also predicts risk. However, few studies have investigated whether parenting factors (e.g., acceptance, conflict, parental psychopathology) moderate the etiology of CU traits, while accounting for gene-environment correlations. To address this knowledge gap, we used data from 772 twin pairs from the Adolescent Brain and Cognitive Development Study to test bivariate models that explored overlapping etiological influences on CU traits and child reports of their parenting environment. We also used gene-by-environment interaction models to test whether parenting moderated genetic versus environmental influences. There were no overlapping etiological influences on CU traits and parental acceptance, but modest genetic and non-shared environmental overlap between CU traits and family conflict. Parental acceptance and psychopathology moderated non-shared environmental influences, with stronger non-shared environmental influences on CU traits among children who experienced lower parental acceptance and greater parental psychopathology. Family conflict only moderated environmental influences when models did not covary for conduct problems. Parental acceptance and parental psychopathology may be specific environmental protective and risk factors for CU traits, whereas family conflict may represent a general environmental risk factor for both CU traits and conduct problems.

An Examination of Parental and Peer Influence on Substance Use and Criminal Offending During the Transition from Adolescence to Adulthood

Although peer behavior and parent-child-conflict have been associated with adolescent and young adults' behavior, prior studies have not adequately controlled for selection effects and other confounders, or examined whether associations change across the transition to adulthood or by race. Using annual data from young men followed from 17-26, within-individual change models examined whether substance use or offending increased in the year after boys began affiliating with friends who engaged in substance use/offending and/or experienced increased parent-son-conflict. Moderation analyses tested whether associations varied by age or race. Alcohol use, marijuana use, and offending (Black participants only) increased in the year after boys began affiliating with more peers who engaged in similar behaviors. Associations were strongest during adolescence for substance use. Parent-son conflict was not associated with the outcomes. Findings underscore the importance of developmental and racialized differences in understanding the role of social influences on young men's substance use and offending.

Pasteurization of chicken litter with steam and quicklime to reduce Salmonella Typhimurium

The nursery industry pasteurizes soil with steam and quicklime to reduce plant pathogens. The mechanism of action for quicklime is the resulting exothermic reaction that occurs when the chemical interacts with water and its ability to increase pH levels. These treatments may also reduce pathogens in a commercial poultry house. In this study, a steam sterilization cart simulated conditions used by the nursery industry to treat litter inoculated with Salmonella enterica serovar Typhimurium. A homogenized sample of litter was exposed to steam for 0, 5, 30, or 120 min. Quicklime was used at concentrations of 0 (control), 2.5, 5.0, or 10.0%. All steam treatments, with or without quicklime, significantly reduced Salmonella Typhimurium colonization by at least 3 orders of magnitude. Significant reductions were also observed in the treatments with quicklime alone. Both the steam and the quicklime treatments often reduced colonization to undetectable levels, even when samples were enriched. Therefore, we demonstrated 2 novel techniques for reducing Salmonella Typhimurium in poultry litter. Soil pasteurization potentially offers an environmentally sound means of reducing the pathogens present in used poultry litter.

Phase I/II study of idarubicin (Ida), high-dose ara-C, and sorafenib (S) in patients (pts) younger than 65 years with acute myeloid leukemia (AML)

7018

Background: S is an oral multi-kinase inhibitor with activity against the Raf/ERK/MEK pathway and FLT3. It selectively induces apoptosis in FLT3-mutant human AML cell lines at nM concentrations. Methods: Objectives of this study are to determine the tolerability and efficacy of combination of S with chemotherapy. Ara-C 1.5 g/m2 over 24 hrs daily x 4 (x 3 for pts over 60) and Ida 12 mg/m2 daily x 3 are administered with S. In the phase I part, pts with relapsed AML were treated with escalating doses of S (400 mg qod, 400 mg daily, 400 mg bid) for 7 days during induction, and 400 mg bid was established as safe. Pts achieving CR receive up to 5 courses of consolidation with Ida 8 mg/m2 daily x 2 and Ara-C 0.75 g/m2 daily x 3 in addition to S 400 mg bid for up to 28 days per cycle repeated every 4 to 6 weeks. Maintenance is with S 400 mg bid for up to a year. Results: 10 pts (median age 34, range 21–58) with relapsed AML (median prior therapy 2, range 1–6) were treated in the phase I . 7 were FLT3-ITD positive. 4 achieved CR; 6 failed. In the phase II part, 45 pts (12 with FLT3-ITD and 2 with FLT3-TKD) were treated. Median age is 53 (range 18 - 65). Cytogenetics were diploid in 19, +8 in 5, -5/-7 in 5, 11q23 in 2, other in 14. Median presentation WBC was 4.9 x 109/L (range 0.6 - 122.7 x 109/L). 8 pts were FLT3-ITD+/NPM1-. 40 pts are evaluable for response and 85% achieved CR (n = 30) or CRp (n = 4) (13 of 14 FLT3 mutated pts); 5 pts are too early (1 FLT3 mutated). Most frequent grade 3 and higher related adverse events: hyperbilirubinemia (5), rash and hand-foot syndrome (3), raised transaminases (2), diarrhea (2), hypertension (2). With a median f/u of 5.4 mo (range, 0.5 - 11.3), the probability of survival at 6 mo is 81.6%. 5 pts have relapsed; median CR duration has not been reached, (range; 0.2+ - 10.6+ mo). Among pts with FLT3 mutation, 4 have relapsed and 9 remain in CR. Plasma inhibitory assay was performed using day 7 samples from 10 pts; mutant FLT3 was suppressed by all with 5-fold more potent suppression against mutant versus wild-type FLT3. Conclusions: S can be safely combined with IA; it has a high CR rate in frontline therapy of younger pts with AML, in particular those with FLT3 mutations. Correlative studies confirm potent activity of S against FLT3 signaling.

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Colonocyte differentiation is associated with increased expression and altered distribution of protein kinase C isozymes

BACKGROUND & AIMS

Colon cancer cells express reduced levels of protein kinase C (PKC). This study examines the regulation of PKC isozymes in normal colonic epithelium, as a basis for understanding the significance of alterations in this enzyme system in colon carcinogenesis.

METHODS

The expression and localization of PKC isozymes in mouse and rat colonocytes at different developmental stages were determined using a combined morphological and biochemical approach. PKC alpha expression was compared in colonic adenocarcinomas and adjacent normal mucosa by immunoblot analysis.

RESULTS

Mouse and rat colonocytes express PKC alpha, beta II, delta, epsilon, and zeta. Relatively low levels of these isozymes were detected in proliferating cells of the crypt base, predominantly in the cytosolic compartment. Coincident with colonocyte growth arrest/differentiation, PKC isozyme expression markedly increased in both the cytosolic and, more significantly, in the membrane/cytoskeletal fraction. Colonic tumors express reduced levels of PKC alpha, an isozyme that has been implicated in negative control of intestinal cell growth.

CONCLUSIONS

These findings are supportive of a role for certain PKC isozyme(s) in signaling pathways mediating postmitotic events in colonocytes in situ, and suggest that diminished activity of these pathway(s) may contribute to the alterations in growth control/differentiation associated with colonic neoplasia.

The effect of phenobarbital pretreatment on the antitumor activity of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU) and 1-(2-chloroethyl)-3-(2,6-dioxo-3-piperidyl-1-nitrosourea (PCNU), and on the plasma pharmacokinetics and biotransformation of BCNU

Many patients being treated for primary and secondary brain tumors receive phenobarbital as an anticonvulsant. The effects of chronic oral administration of phenobarbital on the antitumor activity of BCNU, CCNU and PCNU against the intracerebral 9L tumor in rats were determined. Phenobarbital pretreatment eliminated the antitumor activity of BCNU and reduced the activity of PCNU and CCNU. Pretreatment with phenytoin, sodium methylprednisolone succinate and dexamethasone had little or no effect. Pharmacokinetic data for i.v. BCNU in the plasma of rats showed an increase in drug clearance for phenobarbital pretreated animals, compared to a control group. Larger differences were observed when BCNU was given i.p. The half-life of BCNU in sera from pretreated and control group rats was similar. Finally, the in vitro rate of BCNU disappearance in 9000 X g supernatants and microsomes from the livers of pretreated rats was 5-fold faster than the rate of disappearance of BCNU in supernatants from normal animals. We conclude that the chronic oral administration of phenobarbital induces a change in liver enzymes, which accelerates the clearance of BCNU, thereby reducing the antitumor activity of BCNU and the other nitrosoureas. Phenobarbital pretreatment reduces systemic BCNU toxicity.