The Psychophysiology of Intrusive Cognitions: Comparing Thought Suppression Vs Acceptance

Intrusive cognitions are a natural occurrence within our stream of consciousness, however, when they become repetitive, negative, distressing, and difficult to control, they may warrant clinical concern. Thought suppression is a common control strategy used to manage intrusive thoughts even though research suggests it may actually exacerbate the problem. Conversely, acceptance-based interventions have gained recent attention as an alternative strategy for managing distressing internal experiences. Only preliminary research has focused on the psycho- and neurophysiological bases of intrusive cognitions, and their relationship to cognitive control strategies. Evidence suggests that the anterior cingulate cortex (ACC) may be a brain region critically involved in this process. The present investigation compared the subjective, behavioral, and physiological effects of a thought suppression and acceptance strategy in a sample of university students with high or low obsessive-compulsive (OC) characteristics who were exposed to an emotion-evoking film clip. Participants were instructed either to suppress or accept any intrusive cognitions during a rest period after the film clip, while monitoring for the number of intrusions. Next, psychophysiological signals and reaction times were measured while participants performed a variant of the Stroop task. The commission of errors during a forced choice task generates an error-related negativity (ERN), which is believed to index activity in the ACC. Results showed that self-reported intrusions during the rest interval were greater for the acceptance group and the high-OC group. Correlations suggested that participants who reported more effort at suppression also indicated more distress about their thoughts, whereas those who reported more acceptance indicated less distress. During Stroop task errors, the ERN was apparent as a maximal frontal negativity, and was larger for the suppression group than the acceptance group at a frontal scalp site (Fz), but not a central scalp site (Cz). Correlations between self-reported intrusions at rest and ERN amplitude indicated that participants who reported fewer intrusions demonstrated enhanced ERNs, a marker for increased ACC activity. These findings may be interpreted as supporting the hypothesis that thought suppression is associated with increased ACC activity and greater self-reported discomfort with the intrusions

Alterations of MEK1/2-ERK1/2, IFNγ and Smad2/3 associated Signalling pathways during cryopreservation of ASCs affect their differentiation towards VSMC-like cells

Vascular smooth muscle cells (VSMCs) play essential roles in regulating blood vessel form and function and they are required for vascular tissue regeneration. Multipotent adipose derived stromal cells (ASCs) can be differentiated into VSMC-like cells, which can be used as a potential VSMC source for the development of vascular tissue. However, the effects of cryopreservation on the differentiation of ASCs towards VSMCs are poorly studied to date. This study compared fresh ASCs (FA) vs. cryopreserved ASCs (CA) with respect to their differentiation potential towards VSMC-like cells. The expression of contractile VSMC markers (such as smoothelin) and cell contractility were investigated. It was found that VSMC-like cells derived from CA expressed smoothelin gene and protein at lower levels and showed compromised contractility in response to vasoconstrictors, when compared with those derived from FA. Moreover, it was demonstrated that this negative effect of cryopreservation could be mediated by MEK1/2-ERK1/2, IFNγ and Smad2/3 associated Signalling pathways. Treatment of CA with MEK1/2-ERK1/2 activator or IFNγ neutralizing antibodies enhanced Smad2/3 phosphorylation and showed a rescue of the negative effect of cryopreservation on the differentiation of ASCs towards VSMC-like cells. These findings are important for defining approaches that may use cryopreserved ASCs for vascular tissue regeneration. Keywords: Adipose derived stromal cells, Vascular smooth muscle cell differentiation, Cryopreservation, Smoothelin, Interferon gamma, Extracellular signal regulated kinas

Suppress or accept? A pilot study to evaluate the effect of coping strategies on ERN amplitude among individuals with obsessive-compulsive traits

Intrusive thoughts are characteristic of psychological disorders; attempts to cope can become maladaptive perpetuating the problem (e.g., thought suppression), while others can provide long-term symptoms relief (e.g., acceptance). Although emerging research begins to explore the neural correlates of these strategies in healthy population, it is important to explore these strategies in populations more likely to naturally attempt to use such strategies (clinical symptoms). The present study explored if the use of cognitive strategies to manage intrusive cognitions would be differentially reflected in psychophysiological measures (i.e., error-related negativity) of individuals characterized by obsessive-compulsive symptoms -a group commonly associated with suppression efforts- relative to a low OC control. 67 participants with high and low OC symptoms were randomly assigned to cognitive strategy (suppression or acceptance). Participants watched an emotion-eliciting video clip and used the assigned cognitive strategy while performing the Stroop task. EEG data was collected. Consistent with well-established and emerging literature, ERN was enhanced in individuals with high OC symptoms and a marginal effect of thought-control strategy was observed, such that ERN amplitude was reduced in the suppression condition and greater for the acceptance condition. Uniquely, the study expanded on emerging literature by exploring whether the relationship between ERN and cognitive strategies was moderated by OC level. Although results were not conclusive, these preliminary findings represent an important first step to study effects of suppression and acceptance on the ERN in a sample characterized by clinically-relevant symptoms and overall encourage further exploration

Green Tea Increases the Concentration of Total Mercury in the Blood of Rats following an Oral Fish Tissue Bolus

Fish has many health benefits but is also the most common source of methylmercury. The bioavailability of methylmercury in fish may be affected by other meal components. In this study, the effect of green tea on the bioavailability of methylmercury from an oral bolus of fish muscle tissue was studied in rats and compared to a water treated control group and a group treated with meso-2,3-dimercaptosuccinic acid (DMSA), a compound used medically to chelate mercury. Rats were given a single oral dose of fish tissue via gavage and one of the treatments. Rats were given access to food for 3 h at 12 h intervals. They were dosed with each of the treatments with each meal. Blood samples were collected for 95 hours. Green tea significantly increased the concentration of total mercury in blood relative to the control, whereas DMSA significantly decreased it. In addition, feeding caused a slight increase in blood mercury for several meals following the initial dose

Green Tea Increases the Concentration of Total Mercury in the Blood of Rats following an Oral Fish Tissue Bolus

Fish has many health benefits but is also the most common source of methylmercury. The bioavailability of methylmercury in fish may be affected by other meal components. In this study, the effect of green tea on the bioavailability of methylmercury from an oral bolus of fish muscle tissue was studied in rats and compared to a water treated control group and a group treated with meso-2,3-dimercaptosuccinic acid (DMSA), a compound used medically to chelate mercury. Rats were given a single oral dose of fish tissue via gavage and one of the treatments. Rats were given access to food for 3 h at 12 h intervals. They were dosed with each of the treatments with each meal. Blood samples were collected for 95 hours. Green tea significantly increased the concentration of total mercury in blood relative to the control, whereas DMSA significantly decreased it. In addition, feeding caused a slight increase in blood mercury for several meals following the initial dose

Differential Regulation of Extracellular Matrix Components Using Different Vitamin C Derivatives in Mono- and Coculture Systems

Vascular tissue engineering strategies using cell-seeded scaffolds require uniformly distributed vascular cells and sufficient extracellular matrix (ECM) production. However, acquiring sufficient ECM deposition on synthetic biomaterial scaffolds during the in vitro culture period prior to tissue implantation still remains challenging for vascular constructs. Two forms of vitamin C derivatives, ascorbic acid (AA) and sodium ascorbate (SA), are commonly supplemented in cell culture to promote ECM accumulation. However, the literature often refers to AA and SA interchangeably, and their differential effects on cell growth and ECM molecule (glycosaminoglycan, collagen, elastin) accumulation have never been reported when used in monoculture or coculture systems developed with synthetic three-dimensional (3D) scaffolds. In this study, it was found that 200 μM AA stimulated an increase in cell number, whereas SA (50, 100, and 200 μM) supported more calponin expression (immunostaining) and higher ECM accumulation from vascular smooth muscle cells (VSMCs) after 1 week in the degradable polar hydrophobic ionic polyurethane scaffold. The influence of AA and SA on ECM deposition was also studied in VSMC-monocyte cocultures to replicate some aspects of a wound healing environment in vitro and compared to their effects in respective VSMC monocultures after 4 weeks. Although 100 μM SA promoted ECM deposition in coculture, the condition of 100 μM AA + 100 μM SA was more effective toward enhancing ECM accumulation in VSMC monoculture after 4 weeks. The results demonstrated that AA and SA are not interchangeable, and the different effects of AA and/or SA on ECM deposition were both culture system (co- vs monoculture) and culture period (1 vs 4 week) dependent. This study provides further insight into practical vascular tissue engineering strategies when using 3D synthetic biomaterial-based constructs

Serum- and xeno-free culture of human umbilical cord perivascular cells for pediatric heart valve tissue engineering

Abstract Background Constructs currently used to repair or replace congenitally diseased pediatric heart valves lack a viable cell population capable of functional adaptation in situ, necessitating repeated surgical intervention. Heart valve tissue engineering (HVTE) can address these limitations by producing functional living tissue in vitro that holds the potential for somatic growth and remodelling upon implantation. However, clinical translation of HVTE strategies requires an appropriate source of autologous cells that can be non-invasively harvested from mesenchymal stem cell (MSC)-rich tissues and cultured under serum- and xeno-free conditions. To this end, we evaluated human umbilical cord perivascular cells (hUCPVCs) as a promising cell source for in vitro production of engineered heart valve tissue. Methods The proliferative, clonogenic, multilineage differentiation, and extracellular matrix (ECM) synthesis capacities of hUCPVCs were evaluated in a commercial serum- and xeno-free culture medium (StemMACS™) on tissue culture polystyrene and benchmarked to adult bone marrow-derived MSCs (BMMSCs). Additionally, the ECM synthesis potential of hUCPVCs was evaluated when cultured on polycarbonate polyurethane anisotropic electrospun scaffolds, a representative biomaterial for in vitro HVTE. Results hUCPVCs had greater proliferative and clonogenic potential than BMMSCs in StemMACS™ (p < 0.05), without differentiation to osteogenic and adipogenic phenotypes associated with valve pathology. Furthermore, hUCPVCs cultured with StemMACS™ on tissue culture plastic for 14 days synthesized significantly more total collagen, elastin, and sulphated glycosaminoglycans (p < 0.05), the ECM constituents of the native valve, than BMMSCs. Finally, hUCPVCs retained their ECM synthesizing capacity after 14 and 21 days in culture on anisotropic electrospun scaffolds. Conclusion Overall, our findings establish an in vitro culture platform that uses hUCPVCs as a readily-available and non-invasively sourced autologous cell population and a commercial serum- and xeno-free culture medium to increase the translational potential of future pediatric HVTE strategies. Graphical Abstract This study evaluated the proliferative, differentiation and extracellular matrix (ECM) synthesis capacities of human umbilical cord perivascular cells (hUCPVCs) when cultured in serum- and xeno-free media (SFM) against conventionally used bone marrow-derived MSCs (BMMSCs) and serum-containing media (SCM). Our findings support the use of hUCPVCs and SFM for in vitro heart valve tissue engineering (HVTE) of autologous pediatric valve tissue. Figure created with BioRender.com

Additional file 1 of Serum- and xeno-free culture of human umbilical cord perivascular cells for pediatric heart valve tissue engineering

Additional file 1. Supplemental Materials and Methods