Daily and Half-yearly Associations between Boundary Diffusion and Parent-adolescent Relationship Quality after Divorce.

Boundary diffusion is a particular risk after divorce and has been associated with adolescents' adjustment problems. Yet, its potential impact on parent-adolescent relationship quality is less straightforward, as previous findings support both an alienation and conflict perspective. Therefore these associations (daily and half-yearly) were examined in recently divorced families, addressing both within-dyad changes and between-dyad differences. Data were collected among a sample of N = 133 (pre)adolescents (Mage = 11.76; 51.5% boys) from 76 divorced families, using a measurement burst design: Every six months, 14 consecutive days of daily diaries were collected, for 5 waves. Between dyads, adolescents who experienced more boundary diffusion than others, also reported more conflict with both their parents. Within dyads, when adolescents experienced more boundary diffusion than usual by one of their parents (actor), warmth decreased and conflict increased between this parent and the adolescent, that same and the following day. Adolescents also engaged in more conflict with the other parent that day. These findings mostly supported the conflict perspective: Post-divorce boundary diffusion appears to be a general risk factor for parent-adolescent conflict with both parents, and from day-to-day boundary diffusion was linked to a deteriorated parent-adolescent relationship quality, especially with the parent that triangulated or parentified them. There were no significant long-term associations, nor did any moderator (age, gender, living arrangement) explain heterogeneity in effects.

Divorce and physical health: A three-level meta-analysis.

Divorce is often considered a major and stressful life transition. Given that divorcees are overrepresented in primary care and there is a association between individuals' physical health and psychological adjustment, potential post-divorce health problems are of concern. Yet, empirical evidence is lacking on the magnitude of the overall physical health risk after divorce, on possible differences across specific pathologies, and on factors that may increase or reduce this risk. The current meta-analysis addresses these issues. We identified 94 studies including u = 248 relevant effect sizes, based on N = 1,384,507 participants. Generally, compared to married individuals, divorcees showed significantly worse self-reported health (OR = 1.20, [1.08-1.33]), experienced more physical symptoms (OR = 1.34, [1.17-1.53]), and had a higher risk for diabetes (OR = 1.18 [1.05-1.33]), joint pathologies (OR = 1.24, [1.14-1.34]), cardiovascular (OR = 1.24, [1.09-1.41]) and cerebrovascular conditions (OR = 1.31, [1.14-1.51]), and sexually transmitted diseases (OR = 2.48, [1.32-4.64]). However, they had no increased risk of hypertension, hypercholesterolemia, cancer and cancer development, disabilities or limitations, or cognitive pathologies. Nor did divorcees significantly differ from married individuals when aggregating all pathologies to measure overall physical health problems (OR = 1.14, [0.85 to 1.54]). Yet, moderation analyses revealed that being female, unemployed, childless, or having a lower education constitutes a higher risk for overall physical health problems after divorce. The same applied to having a heavy alcohol consumption, lack of exercise, and being overweight. Our meta-analysis shows that divorcees are at heightened risk of certain pathologies, with sexually transmitted diseases as a particular post-divorce hazard. These findings call for more awareness among counsellors and physicians on divorcees' health conditions and the characteristics that make divorcees even more vulnerable to health problems.

Persistent organic pollutants in air from Asia, Africa, Latin America, and the Pacific.

In support of the United Nations Environment Programme (UNEP) global monitoring plan under the Stockholm Convention concentrations of persistent organic pollutants (POPs) were determined during two years in air from 42 countries in Asia, Africa, Latin America, and the Pacific by using polyurethane foams installed in passive samplers. The compounds included were polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated diphenylethers (PBDEs), one polybrominated biphenyl and hexabromocyclododecane (HBCD) diastereomers. Total-DDT and PCBs were the highest in concentrations in about 50% of the samples, which shows their high persistency. Total DDT in air from the Solomon Islands ranged from 200 to 600 ng/polyurethane foam disk (PUF). However, at most locations, a decreasing trend is observed for PCBs, DDT and most other OCPs. Patterns varied per country with e.g. elevated dieldrin in air from Barbados and chlordane in air from the Philippines. A number of OCPs, such as heptachlor and its epoxides, some other chlordanes, mirex and toxaphene have decreased down to almost undetectable levels. PBB153 was hardly found and penta and octa--mix related PBDEs were also relatively low at most locations. HBCD and the decabromodiphenylether were more prominent at many locations and may even still increase. To draw more holistic conclusions more colder climate countries should be included in this program.

Triangulation and child adjustment after parental divorce: Underlying mechanisms and risk factors.

Parental triangulation is a particular risk to healthy child adjustment after divorce. However, detailed knowledge is lacking on how triangulation predicts child adjustment, and whether some children are more vulnerable to triangulation's effects. Therefore, the present study used a sample of 135 children (Mage = 11.76) and 130 parents from 77 recently divorced families to identify whether intrapersonal processes (loyalty conflicts, self-blame, and self-esteem) underlie the link between postdivorce triangulation and child adjustment over a period of 2 years. We also explored whether these direct and indirect effects were dependent on children's environmental sensitivity and empathy. By means of path analysis in MPlus, the mediation analyses indicated that more triangulation was only indirectly associated with a relative increase in children's internalizing problems, via experiencing more loyalty conflicts and lower self-esteem. Loyalty conflicts also explained the link between triangulation and children's externalizing problems. Yet, there were no indirect effects via children's self-blame attributions. Second, moderation analyses revealed that the effect of triangulation was dependent on children's level of empathy, but not sensitivity. Children scoring high on empathy showed a stronger association between triangulation and child-reported adjustment problems, both directly and indirectly via loyalty conflicts and self-esteem. There were hardly any significant effects for parent-reported child adjustment. Overall, the present study calls for more awareness on the adversity of postdivorce triangulation for children, its working mechanisms, and the factors that make children more vulnerable to its detrimental effects. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Problematic Internet Use in Adolescents from Divorced Families: The Role of Family Factors and Adolescents' Self-Esteem.

Family functioning is salient in explaining adolescents' problematic internet use (PIU), and precisely this family functioning is under pressure after parental divorce. Moreover, growing up with divorced parents is identified as a risk factor for PIU. Therefore, examining which factors are associated with adolescents' PIU after divorce is particularly important. Based on self-report data from N = 244 adolescents of divorced families (49.6% boys, M = 13.42), structural equation modeling (SEM) was used to examine the associations of PIU with interparental conflict, triangulation, maternal and paternal warmth, and adolescents' self-esteem. Potential buffering effects of self-esteem were tested, as well as gender differences in associations. The results showed that more triangulation and less maternal warmth were related to higher levels of PIU, but these effects disappeared after adding self-esteem to the models. Adolescent self-esteem did not significantly buffer the effects of the different family factors on PIU, nor were there any significant gender differences in association. Hence, especially adolescents' self-esteem seems to be a key aspect for PIU in adolescents from divorced families.

A meta-analysis on interparental conflict, parenting, and child adjustment in divorced families: Examining mediation using meta-analytic structural equation models.

Every year, parental divorce becomes the reality of many families. The aim of this meta-analysis was to identify post-divorce family processes to explain child functioning. Both direct and indirect associations between interparental conflict, parenting, and child adjustment were examined. After a systematic search for articles published before October 2019, we coded 2257 correlations in 115 samples of N = 24,854 divorced families. Analyses consisted of: (1) Performing multiple three-level meta-analyses to calculate the bivariate correlations between interparental conflict, parenting (i.e., support, hostility, structuring, intrusiveness, parent-child relationship quality, parent-child conflict, and role diffusion) and child psychosocial adjustment. (2) Testing four meta-analytic structural equation models in which parenting dimensions were examined as potential mediators. First, results showed that correlations between interparental conflict, parenting, and child adjustment were mostly significant, in the expected direction, and of small effect size. Second, parental support, hostility, structuring, intrusiveness, and role diffusion indeed served as mediating mechanisms underlying the persistent link between interparental conflict and children's internalizing and externalizing problems. This was not true for dyadic parent-child processes. Third, our findings hinted towards a stronger impact of negative versus positive parenting behaviors, and parental role diffusion was considered a particular risk in the context of post-divorce interparental conflict.

The effects of LXR agonist T0901317 and LXR antagonist GSK2033 on morphogenesis and lipid properties in full thickness skin models.

Full thickness models (FTMs) are 3D-cultured human skin models that mimic many aspects of native human skin (NHS). However, their stratum corneum (SC) lipid composition differs from NHS causing a reduced skin barrier. The most pronounced differences in lipid composition are a reduction in lipid chain length and increased monounsaturated lipids. The liver-X-receptor (LXR) activates the monounsaturated lipid synthesis via stearoyl-CoA desaturase-1 (SCD-1). Therefore, the aim was to improve the SC lipid synthesis of FTMs by LXR deactivation. This was achieved by supplementing culture medium with LXR antagonist GSK2033. LXR agonist T0901317 was added for comparison. Subsequently, epidermal morphogenesis, lipid composition, lipid organization and the barrier functionality of these FTMs were assessed. We demonstrate that LXR deactivation resulted in a lipid composition with increased overall chain lengths and reduced levels of monounsaturation, whereas LXR activation increased the amount of monounsaturated lipids and led to a reduction in the overall chain length. However, these changes did not affect the barrier functionality. In conclusion, LXR deactivation led to the development of FTMs with improved lipid properties, which mimic the lipid composition of NHS more closely. These novel findings may contribute to design interventions to normalize SC lipid composition of atopic dermatitis patients.

Skin of atopic dermatitis patients shows disturbed ß-glucocerebrosidase and acid sphingomyelinase activity that relates to changes in stratum corneum lipid composition.

Patients with Atopic Dermatitis (AD) suffer from inflamed skin and skin barrier defects. Proper formation of the outermost part of the skin, the stratum corneum (SC), is crucial for the skin barrier function. In this study we analyzed the localization and activity of lipid enzymes ß-glucocerebrosidase (GBA) and acid sphingomyelinase (ASM) in the skin of AD patients and controls. Localization of both the expression and activity of GBA and ASM in the epidermis of AD patients was altered, particularly at lesional skin sites. These changes aligned with the altered SC lipid composition. More specifically, abnormal localization of GBA and ASM related to an increase in specific ceramide subclasses [AS] and [NS]. Moreover we related the localization of the enzymes to the amounts of SC ceramide subclasses and free fatty acids (FFAs). We report a correlation between altered localization of active GBA and ASM and a disturbed SC lipid composition. Localization of antimicrobial peptide beta-defensin-3 (HBD-3) and AD biomarker Thymus and Activation Regulated Chemokine (TARC) also appeared to be diverging in AD skin compared to control. This research highlights the relation between correct localization of expressed and active lipid enzymes and a normal SC lipid composition for a proper skin barrier.

Shedding light on the effects of 1,25-dihydroxyvitamin D3 on epidermal lipid barrier formation in three-dimensional human skin equivalents.

Human skin equivalents (HSEs) are three dimensional models resembling native human skin (NHS) in many aspects. Despite the manifold similarities to NHS, a restriction in its applications is the altered in vitro lipid barrier formation, which compromises the barrier functionality. This could be induced by suboptimal cell culturing conditions, which amongst others is the diminished activation of the vitamin D receptor (VDR) signalling pathway. The active metabolite of this signalling pathway is 1,25-dihydroxyvitamin D3 (1,25(OH)2D3). An interacting role in the formation of the skin barrier has been ascribed to this pathway, although it remains unresolved to which extent this pathway contributes to the (mal-)formation of the epidermal barrier in HSEs. Our aim is to study whether cell culture medium enriched with 1,25(OH)2D3 affects epidermal morphogenesis and lipid barrier formation in HSEs. Addition of 20 nM 1,25(OH)2D3 resulted in activation of the VDR signalling pathway by inducing transcription of VDR target genes (CYP24A and LL37) in keratinocyte monocultures and in HSEs. Characterization of HSEs supplemented with 1,25(OH)2D3 using immunohistochemical analyses revealed a high similarity in epidermal morphogenesis and in expression of lipid processing enzymes. The barrier formation was assessed using state-of-the art techniques analysing lipid composition and organization. Addition of 1,25(OH)2D3 did not alter the composition of ceramides. Additionally, the lateral and lamellar organization of the lipids was similar, irrespective of supplementation. In conclusion, epidermal morphogenesis and barrier formation in HSEs generated in presence or absence of 1,25(OH)2D3 leads to a similar morphogenesis and comparable barrier formation in vitro.

Human skin equivalents cultured under hypoxia display enhanced epidermal morphogenesis and lipid barrier formation.

Human skin equivalents (HSEs) are three-dimensional cell models mimicking characteristics of native human skin (NHS) in many aspects. However, a limitation of HSEs is the altered in vitro morphogenesis and barrier formation. Differences between in vitro and in vivo skin could have been induced by suboptimal cell culture conditions, of which the level of oxygen in vitro (20%) is much higher than in vivo (0.5-8%). Our aim is to study how external oxygen levels affect epidermal morphogenesis and barrier formation in HSEs. In the present study, fibroblast and keratinocyte monocultures, and HSEs were generated under 20% (normoxia) and 3% (hypoxia) oxygen level. In all cultures under hypoxia, expression of hypoxia-inducible factor target genes was increased. Characterization of HSEs generated under hypoxia using immunohistochemical analyses of morphogenesis biomarkers revealed a reduction in epidermal thickness, reduced proliferation, similar early differentiation, and an attenuated terminal differentiation program compared to normoxia, better mimicking NHS. The stratum corneum ceramide composition was studied with liquid chromatography coupled to mass spectrometry. Under hypoxia, HSEs exhibited a ceramide composition that more closely resembles that of NHS. Consequently, the lipid organization was improved. In conclusion, epidermal morphogenesis and barrier formation in HSEs reconstructed under hypoxia better mimics that of NHS.

Characterization of human skin equivalents developed at body's core and surface temperatures.

Human skin equivalents (HSEs) are in vitro developed three-dimensional models resembling native human skin (NHS) to a high extent. However, the epidermal lipid biosynthesis, barrier lipid composition, and organization are altered, leading to an elevated diffusion rate of therapeutic molecules. The altered lipid barrier formation in HSEs may be induced by standardized culture conditions, including a culture temperature of 37°C, which is dissimilar to skin surface temperature. Therefore, we aim to determine the influence of culture temperature during the generation of full thickness models (FTMs) on epidermal morphogenesis and lipid barrier formation. For this purpose, FTMs were developed at conventional core temperature (37°C) or lower temperatures (35°C and 33°C) and evaluated over a time period of 4 weeks. The stratum corneum (SC) lipid composition was analysed using advanced liquid chromatography coupled to mass spectrometry analysis. Our results show that SC layers accumulated at a similar rate irrespective of culture temperature. At reduced culture temperature, an increased epidermal thickness, a disorganization of the lower epidermal cell layers, a delayed early differentiation, and an enlargement of granular cells were detected. Interestingly, melanogenesis was reduced at lower temperature. The ceramide subclass profile, chain length distribution, and level of unsaturated ceramides were similar in FTMs generated at 37°C and 35°C but changed when generated at 33°C, reducing the resemblance to NHS. Herein, we report that culture temperature affects epidermal morphogenesis substantially and to a lesser extent the lipid barrier formation, highlighting the importance of optimized external parameters during reconstruction of skin.

Unravelling effects of relative humidity on lipid barrier formation in human skin equivalents.

Relative humidity (RH) levels vary continuously in vivo, although during in vitro generation of three-dimensional human skin equivalents (HSEs) these remain high (90-95%) to prevent evaporation of the cell-culture medium. However, skin functionality is directly influenced by environmental RH. As the barrier formation in HSEs is different, there is a need to better understand the role of cell-culture conditions during the generation of HSEs. In this study, we aim to investigate the effects of RH on epidermal morphogenesis and lipid barrier formation in HSEs. Therefore, two types of HSEs were developed at 90% or at 60% RH. Assessments were performed to determine epidermal morphogenesis by immunohistochemical analyses, ceramide composition by lipidomic analysis, and lipid organization by Fourier transform infrared spectroscopy and small-angle X-ray diffraction. We show that reduction of RH mainly affected the uppermost viable epidermal layers in the HSEs, including an enlargement of the granular cells and induction of epidermal cell activation. Neither the composition nor the organization of the lipids in the intercorneocyte space were substantially altered at reduced RH. In addition, lipid processing from glucosylceramides to ceramides was not affected by reduced RH in HSEs as shown by enzyme expression, enzyme activity, and substrate-to-product ratio. Our results demonstrate that RH directly influences epidermal morphogenesis, albeit the in vitro lipid barrier formation is comparable at 90% and 60% RH.

Recapitulation of Native Dermal Tissue in a Full-Thickness Human Skin Model Using Human Collagens.

OBJECTIVE: Full-thickness skin models comprise a three-dimensional dermal equivalent based on an animal-derived collagen matrix that harbors fibroblasts and an epidermal equivalent formed by keratinocytes. The functionality of both equivalents is influenced by many factors, including extracellular matrix composition and resident cell type. Animal-derived collagens differ in amino acid composition and physicochemical properties from human collagens. This composition could alter the functionality of the dermal equivalent and epidermal morphogenesis with the barrier formation in full-thickness models (FTMs). By replacement of animal-derived collagen for human collagen, we generated and characterized the animal material-free human collagen full-thickness models (hC-FTMs) that better mimic native dermal tissue. MATERIALS AND METHODS: An isolation procedure to obtain soluble collagen from human abdominal dermis was developed. Both FTMs and hC-FTMs were generated with primary human fibroblasts and keratinocytes. Immunohistochemical analyses with biomarkers for the dermal matrix composition, basement membrane (BM) formation, epidermal proliferation, differentiation, and activation were performed. The stratum corneum (SC) lipid composition was studied with liquid chromatography-mass spectrometry. Lipid lamellar organization was determined by small-angle X-ray diffraction. RESULTS: The FTMs and hC-FTMs exhibit many similarities, including the dermal matrix structure, BM formation, epidermal basal layer proliferation, and execution of differentiation programs. The SC contains a similar number of corneocyte layers and the same level of lipids. The ceramide chain length distribution and ceramide subclass profile showed only minor differences. Subsequently, this led to an unaltered lamellar organization. CONCLUSION: The animal material-free hC-FTM is generated successfully using collagens isolated from human abdominal dermis. Utilization of human collagens revealed that (epi-)dermal morphogenesis and lipid barrier formation resembled that of original FTMs. The hC-FTMs contain a dermal equivalent that mimics the native stromal tissue to a higher extent. Therefore these in vitro skin models can be used as promising tool for research purposes that contribute to animal-free experimentation.

Mother-Child Interactions and Externalizing Behavior Problems in Preschoolers over Time: Inhibitory Control as a Mediator.

Previous research has shown links between parenting and externalizing behavior problems in young children over time. Associations between inhibitory control, one of the executive functions, and externalizing behavior problems are widely established as well. Yet, the role of inhibitory control in the maintenance and change of externalizing behavior problems over time remains unclear. We examined whether inhibitory control could explain the link between mother-child interactions measured on a moment-to-moment timescale and preschoolers' externalizing behavior problems as reported by teachers. With a sample of 173 predominantly clinically referred preschoolers (76.9% boys) we tested a longitudinal model proposing that affective dyadic flexibility and maternal negative affect predict as well as interact in predicting hyperactive/impulsive behavior and aggressive behavior, with preschoolers' inhibitory control as a mediator. Our results provide support for this model for preschoolers' hyperactive/impulsive behavior, but not for aggressive behavior. Hence, inhibitory control is identified as a mechanism linking the content and structure of mother-child interactions to preschoolers' hyperactivity and impulsivity over time.