Do implant-supported dentures facilitate efficacy of eating more healthily?

Edentulous persons have poor diet quality demonstrating a need for dietary intervention. Implant-supported mandibular overdentures (IODs) have functional advantages over conventional dentures (CD), but whether they enhance the ability to eat more healthily following dietary advice is unknown.     

Posttraumatic Stress Symptoms and Associated Comorbidity During the COVID-19 Pandemic in Ireland: A Population-Based Study

The prevalence of posttraumatic stress disorder (PTSD) as it relates to individuals’ experiences of the COVID-19 pandemic has yet to be determined. This study was conducted to determine rates of COVID-19–related PTSD in the Irish general population, the level of comorbidity with depression and anxiety, and the sociodemographic risk factors associated with COVID-19–related PTSD. A nationally representative sample of adults from the general population of the Republic of Ireland (N = 1,041) completed self-report measures of all study variables. The rate of COVID-19–related PTSD was 17.7% (n = 184), 95% CI [15.35%, 19.99%], and there was a high level of comorbidity with generalized anxiety (49.5%) and depression (53.8%). Meeting the diagnostic requirement for COVID-19–related PTSD was associated with younger age, male sex, living in a city, living with children, moderate and high perceived risk of COVID-19 infection, and screening positive for anxiety or depression. Posttraumatic stress symptoms related to the COVID-19 pandemic are common in the general population. Our results show that health professionals responsible for responding to the COVID-19 pandemic should expect to routinely encounter symptoms and concerns related to posttraumatic stress.     

Network Analysis of Posttraumatic Stress Experiences of Adults Seeking Psychological Treatment for Childhood Sexual Abuse

Network analysis proposes that mental disorders may best be construed as causal systems embodied in networks of functionally interconnected symptoms. We employed network analysis to test how adult survivors of childhood sexual abuse (CSA) experienced symptoms of posttraumatic stress, using alternative conceptualizations of posttraumatic stress disorder (PTSD). Given the characteristics of the sample (i.e., the nature of and time since trauma), we hypothesized that (a) symptoms related to arousal would not be prominent in the networks and (b) symptoms related to negative alternations in cognition and mood (NACM) would be core components in the network. Danish adults seeking psychological treatment for CSA (n = 473) completed the Harvard Trauma Questionnaire and Trauma Symptom Checklist. Three alternative models (DSM-5, DSM-5 with dissociation, and ICD-11 complex PTSD [CPTSD]) were estimated using regularized partial correlation models. In the DSM-5 network, strong associations emerged for experiences of NACM (blame and guilt) and intrusions (thoughts and flashbacks). The addition of “depersonalization” and “derealization” to the DSM-5 model produced a strong association, but these experiences were largely unrelated to other PTSD clusters. In the CPTSD network, interpersonal problems and negative self-concept were central to the survivors’ experiences. For this highly-specific survivor group who experienced traumatic CSA many years ago, experiences related to NACM appeared to be more central to the posttrauma experience than those of arousal. If replicated, these findings could help inform treatment plans for specific groups of survivors. Methodological implications as to the usefulness of network models in the psychopathological research literature are discussed.     

Methodology for the scientific evaluation of complementary and alternative medicine

It has been suggested that CAM research should establish efficacy before examining mechanism. This paper shows that the efficacy-mechanism distinction is a false one, as any test of efficacy assumes a particular mechanism and is a test of the theory underlying that mechanism. The term RCT is currently used in medicine for two different sorts of study. The randomised controlled trial (RConT) requires an experimental manipulation that can 'control' for the mechanism under consideration, and therefore tests the efficacy of that mechanism. The randomised comparison trial (RComT) requires only an experimental manipulation creating a therapeutically relevant comparison, and tests the effectiveness of that therapy. The ability to achieve control coupled with an assumed implausibility of hidden moderating variables characterises drug therapy and some CAM therapies where the RConT can be used. However, other CAM researchers assume a variety of holistic mechanisms, where control is necessarily poor and the hypothesis of complex interactions suggest the existence of multiple moderators. In these cases other experimental (e.g. RComT), quasi-experimental or non-experimental designs are needed to evaluate therapeutic practice. Researchers from both communities should make explicit their underlying assumptions and the mechanisms they seek to evaluate when carrying out empirical studies. Research design needs to be appropriate for the mechanism under test.     

Human spleen cell generation of factors stimulating human pluripotent stem cell, erythroid, and myeloid progenitor cell growth

Mitogen-stimulated murine spleen cells produce humoral substances capable of supporting murine hematopoiesis and pluripotent stem cell proliferation in vitro. Thus, we evaluated conditioned media generated by human spleen cells (SCM) in the presence or absence of mitogens for factors stimulatory for human pluripotent (CFU-GEMM), erythroid (BFU- E), and myeloid (CFU-GM) precursors. Two and one half percent to 10% SCM stimulated proliferation of all three types of precursor cells from nonadherent buoyant human marrow target cells. Mitogen-stimulated SCM augmented CFU-GM (175% to 225%), whereas CFU-GEMM and BFU-E growth was essentially unchanged. Cell separation procedures used to determine which cells provided these microenvironmental stimuli indicated that nonadherent mononuclear spleen cells provided the bulk of the CSF-GM, whereas adherent cells (95% nonspecific esterase + monocyte- macrophages) and nonadherent cells provided similar proportions of CSF- mix and erythroid burst-promoting activity (BPA). The nonadherent cells generating high levels of CSF-mix, BPA, and CSF-GM were predominantly Leu-1-negative, ie, non-T, cells. In the presence or absence of mitogens, SCM was a more potent source (1.3- to 3.8-fold) than peripheral leukocyte CM of the growth factors for the three progenitor cell types. Specific in situ cytochemical stains for analyzing morphology of myeloid colonies demonstrated that SCM stimulated the proliferation of the same types and proportions of colonies as human placental CM, suggesting that these CMs may contain similar CSF-GMs. These data show the contribution of spleen cell subsets to the generation of hematopoietic growth factors and the responsiveness of these cells to various mitogenic stimuli.     

Suppressor screen in Mpl-/- mice: c-Myb mutation causes supraphysiological production of platelets in the absence of thrombopoietin signaling

Genetic screens in lower organisms, particularly those that identify modifiers of preexisting genetic defects, have been used successfully to order components of complex signaling pathways. To date, similar suppressor screens have not been used in vertebrates. To define the molecular pathways regulating platelet production, we have executed a large-scale modifier screen with genetically thrombocytopenic Mpl(-/-) mice by using N-ethyl-N-nitrosourea mutagenesis. Here we show that mutations in the c-Myb gene cause a myeloproliferative syndrome and supraphysiological expansion of megakaryocyte and platelet production in the absence of thrombopoietin signaling. This screen demonstrates the utility of large-scale N-ethyl-N-nitrosourea mutagenesis suppressor screens in mice for the simultaneous discovery and in vivo validation of targets for therapeutic discovery in diseases for which mouse models are available.