Suicide Postvention for the United States Military: Literature Review,Conceptual Model,and Recommendations

Suicide continues to be a significant public health problem in the United States and the Department of Defense (DoD). Timely and systematic postvention efforts can play an instrumental role in helping family members, peers, and military command to best manage the aftermath of a suicide. To date, several postvention efforts have been implemented in the military. However, there continues to be an overall lack of understanding of the specific short- and long-term effects of exposure to military suicide. In addition, more emphasis needs to be placed on empirically driven approaches to postvention and program evaluation. The purpose of this article is threefold: (1) to provide a summary of the postvention literature with special emphasis placed on the military organization; (2) to propose a conceptual model as a framework for understanding Military-Unit Suicide Survivorship; and (3) to briefly highlight postvention strategies within the DoD in the context of a number of research, clinical, and policy recommendations.     

Xanthohumol ameliorates 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin–induced cellular toxicity in cultured MC3T3‐E1 osteoblastic cells

2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD) is an environmental contaminant. Xanthohumol is a prenylated flavonoid found in hops (Humulus lupulus) and beer. The aim of the current study was to explore the role of xanthohumol in modulating the toxicity of TCDD in MC3T3‐E1 osteoblastic cells. In cells treated with TCDD alone, intracellular Ca²⁺ concentrations, mitochondrial membrane potential disruption, reactive oxygen species production, cardiolipin peroxidation, nitric oxide release and cytochrome P450 1A1 expression were significantly increased. TCDD treatment increased the mRNA levels of extracellular signal‐regulated kinase 1 and nuclear factor kappa B, and significantly decreased the level of protein kinase B (AKT) in MC3T3‐E1 osteoblastic cells. However, the presence of xanthohumol alleviated the pathological effects of TCDD. In addition, xanthohumol treatment significantly increased the expression of genes associated with osteoblast differentiation (alkaline phosphatase, osteocalcin, osteoprotegerin and osterix). We conclude that xanthohumol has a beneficial influence and may antagonize TCDD toxicity in osteoblastic cells.     

Health service utilization,unmet healthcare needs,and the potential of telemedicine services among Korean expatriates

Background

With the significant growth of migration and expatriation, facilitated by increased global mobility, the number of Koreans living abroad as of 2016 is approximately 7.4 million (15% of the Korean population). Healthcare utilization or health problems, especially among expatriates in developing countries, have not been well researched despite the various health risks these individuals are exposed to. Consequently, we identified the health utilization patterns and healthcare needs among Korean expatriates in Vietnam, Cambodia, and Uzbekistan.

Methods

This cross-sectional survey examined 429 Korean expatriates living in Vietnam (n?=?208), Cambodia (n?=?60), and Uzbekistan (n?=?161) who had access to the Internet and were living abroad for at least 6?months. A 67-item questionnaire was used, and feedback was received via an online survey program. Stepwise logistic regression analyses were performed to evaluate factors associated with unmet healthcare needs and preferences of certain type of telemedicine.

Results

We found that 45.5% (195/429) of respondents had used medical services in their country of stay. Among those who visited health institutions >?3 times, the most popular choice was general hospitals (39.4%, 15/38); however, they initially visited Korean doctors’ or local doctors’ offices. The most essential criteria for healthcare service facilities was a “skilled professional” (39.3%, 169/429), 42% wanted a health program for chronic disease management, and 30% wanted specialized internal medicine. A substantial number wanted to access telemedicine services and were willing to pay for this service. They were particularly interested in experts’ second opinion (61.5%, 264/429) and quick, 24-h medical consultations (60.8%, 261/429). Having unmet healthcare needs and being younger was strongly associated with all types of telemedicine networks.

Conclusions

Nearly half of the expatriates in developing countries had unmet healthcare needs. Telemedicine is one potential solution to meet these needs, especially in developing countries.

     

Pain prevalence and severity before, during, and after root canal treatment: a systematic review

Introduction

Anticipation and experience of root canal associated pain is a major source of fear for patients and a very important concern of dentists. Pretreatment, treatment, and posttreatment pain is anticipated, experienced, remembered, and shared by patients. The purpose was to determine the influence of root canal treatment on pain prevalence and severity and estimate the prevalence and severity of pretreatment, treatment, and posttreatment pain in patients receiving root canal treatment.

Methods

Defined searching of MEDLINE, Embase, Cochrane, and PsycINFO databases identified 5,517 articles. Systematic review, including title scanning, abstract scanning, full-text review, and quality rating, provided 72 studies for meta-analysis. L’Abbe plots were used to evaluate the influence of root canal treatment on pain prevalence and severity. Pretreatment, treatment, and posttreatment pain prevalence and severity data were analyzed.

Results

L’Abbe plots revealed that pain prevalence and severity decreased substantially after treatment. Mean pretreatment, 24-hour posttreatment, and 1-week posttreatment pain prevalences with associated standard deviations were 81 (28%), 40 (24%), and 11 (14%), respectively. Pretreatment, 24-hour posttreatment, and 1-week posttreatment pain severities, on a 100-point scale, were 54 (24%), 24 (12%), and 5 (5%), respectively. Supplemental injections were frequently required (60 [24%]).

Conclusions

Pretreatment root canal-associated pain prevalence was high but dropped moderately within 1 day and substantially to minimal levels in 7 days. Pretreatment root canal-associated pain severity was moderate, dropped substantially within 1 day of treatment, and continued to drop to minimal levels in 7 days. Supplemental anesthesia was often required.     

Droplet fragmentation: 3D imaging of a previously unidentified pore-scale process during multiphase flow in porous media

Using X-ray computed microtomography, we have visualized and quantified the in situ structure of a trapped nonwetting phase (oil) in a highly heterogeneous carbonate rock after injecting a wetting phase (brine) at low and high capillary numbers. We imaged the process of capillary desaturation in 3D and demonstrated its impacts on the trapped nonwetting phase cluster size distribution. We have identified a previously unidentified pore-scale event during capillary desaturation. This pore-scale event, described as droplet fragmentation of the nonwetting phase, occurs in larger pores. It increases volumetric production of the nonwetting phase after capillary trapping and enlarges the fluid−fluid interface, which can enhance mass transfer between the phases. Droplet fragmentation therefore has implications for a range of multiphase flow processes in natural and engineered porous media with complex heterogeneous pore spaces.Multiphase fluid displacement processes in porous media are important for a broad range of natural and engineering applications such as transport of nonaqueous phase liquid contaminants in aquifers, oil and gas production from hydrocarbon reservoirs, subsurface CO₂ storage, or gas transport in fuel cells. Herein, capillary trapping is a fundamental mechanism that causes immobilization of a portion of the resident nonwetting phase when it is displaced by an invading wetting phase. As a result, production of the nonwetting phase is always less than 100%.The pore-scale physics of capillary trapping are broadly understood, as the underlying mechanisms such as piston-like displacement, snap-off and film development have been observed in physical micromodel experiments and quantitative theories have been established for them (1–4). The conventional view considers such pore-scale processes to occur between multiple pores, i.e., they are interpore processes and the pores are defined as volumes connected by narrower pore throats. By contrast, intrapore processes, as presented in this paper, are not well established in the literature. During drainage (i.e., where a nonwetting phase displaces the wetting phase), the wetting phase can establish films in the corners of the pores, which results in its continuous production and hence low residual saturations of the wetting phase. During imbibition (i.e., where the wetting phase displaces a nonwetting phase), swelling of the corner wetting films causes snap-off of the nonwetting phase, which results in capillary trapping of the nonwetting phase. The trapped nonwetting phase exists as disconnected ganglia within the pore network. Numerical pore network models have been developed to include these pore-level mechanisms with the aim of predicting the macroscopic flow properties of porous materials such as the structure of the phase distributions, residual saturation, relative permeability functions, and capillary pressure curves. Some of these models, referred to as quasi-static models, assume that fluid flow is only governed by capillary forces (5–8), and hence are limited in capturing the dynamics of fluid displacements that occur under the action of both capillary and viscous forces. In another class of pore network models, referred to as dynamic models (9–11), capillary and viscous forces are considered simultaneously. Such models are more applicable in modeling the dynamics of pore-scale events controlled by both capillary and viscous forces.The saturation distribution of two immiscible fluid phases in a porous medium is influenced by the wettability of the system, i.e., the distribution of surfaces that are preferentially water wet or preferentially wetting to a nonaqueous phase such as oil (12). It is known that a trapped nonwetting phase can be remobilized and recovered when the wetting phase is injected at capillary numbers N_c that exceed a critical level. N_c is a dimensionless ratio quantifying the relative importance of viscous to capillary forces, i.e., N_c = vµ/σ where v is the apparent velocity, µ is the viscosity of the invading phase, and σ is the interfacial tension (13). For homogeneous sandstones, remobilization typically occurs at N_c of the order of 10⁻⁵, an effect known as capillary desaturation (14).Recent advances in X-ray computed microtomography (µCT) methods have enabled the visualization and quantitative analysis of the static distribution of fluid phases, fluid rock interactions, and the structure of wetting and nonwetting phases in porous materials (8, 15). A particular focus has been on capillary trapping (16–20). Using synchrotron X-ray μCT facilities, it has also become possible to visualize dynamic pore-scale mechanisms, including snap-off and Haines jumps (21). Most of these imaging studies have focused on relatively homogeneous pore systems such as bead packs (22), sand packs (22–26), and sandstones (8, 18, 21, 23), but less attention has been paid to carbonate rocks. However, more than 50% of the world’s remaining oil reserves are located in carbonate reservoirs (27), and carbonate aquifers supply water wholly or partially to one quarter of the global population (28). Carbonates rocks can have complex multiscale pore structures, which render the application of X-ray µCT more challenging because of the need to select a representative sample that is small enough to achieve high resolutions on µCT images but that also captures the essential heterogeneities of the pore structure (29, 30).In this contribution, we use X-ray µCT to quantify the structure and distribution of a nonwetting phase (oil) after drainage and after its displacement by a wetting phase (brine) at low and high capillary numbers in a heterogeneous carbonate with multiple pore scales. Using image analysis, we demonstrate the effect of capillary desaturation on the cluster size distribution of the trapped oil phase. We identify a previously unidentified pore-scale event, which we refer to as droplet fragmentation. Droplet fragmentation is responsible for further production of the oil phase beyond capillary trapping. This fragmentation process occurs mainly in larger pores. It results in the production of additional oil from these large pores, contributes to a change in the structure of residual oil, and increases the oil−brine surface area. As a consequence, the trapped phase may subsequently be more difficult to mobilize after droplet fragmentation has occurred but mass transfer between the phases can increase.     

Knockout of Lmod2 results in shorter thin filaments followed by dilated cardiomyopathy and juvenile lethality

Leiomodin 2 (Lmod2) is an actin-binding protein that has been implicated in the regulation of striated muscle thin filament assembly; its physiological function has yet to be studied. We found that knockout of Lmod2 in mice results in abnormally short thin filaments in the heart. We also discovered that Lmod2 functions to elongate thin filaments by promoting actin assembly and dynamics at thin filament pointed ends. Lmod2-KO mice die as juveniles with hearts displaying contractile dysfunction and ventricular chamber enlargement consistent with dilated cardiomyopathy. Lmod2-null cardiomyocytes produce less contractile force than wild type when plated on micropillar arrays. Introduction of GFP-Lmod2 via adeno-associated viral transduction elongates thin filaments and rescues structural and functional defects observed in Lmod2-KO mice, extending their lifespan to adulthood. Thus, to our knowledge, Lmod2 is the first identified mammalian protein that functions to elongate actin filaments in the heart; it is essential for cardiac thin filaments to reach a mature length and is required for efficient contractile force and proper heart function during development.Striated muscle cells contain arrays of protein filaments assembled into contractile units that are nearly crystalline in structure. Efficient contraction at the molecular level is predicated upon accurate overlap of actin-containing thin and myosin-containing thick filaments. Therefore, proper control of filament assembly is absolutely critical.In striated muscle it is currently thought that the thin-filament pointed end capping protein tropomodulin (Tmod) is the predominant regulator of thin filament length, with Tmod1 being the sole isoform expressed in cardiomyocytes (1). Extensive in vitro work has revealed that Tmod1 uses two actin- and two tropomyosin-binding sites to associate with the end of the thin filament and to prevent addition or loss of actin monomers, thereby controlling length of the thin filament (2–7). Tmod1 is essential for life; Tmod1-KO mice are embryonic lethal because of cardiac defects (8–11).Identification of additional but structurally different members of the Tmod family of proteins, the leiomodins (Lmods), raises the possibility that thin filament lengths are not regulated solely by Tmod at thin filament pointed ends (12). Although there are three Lmod genes (Lmod1–3), Lmod2 and 3 are expressed in striated muscle with Lmod2 being the predominant isoform in cardiac muscle and Lmod3 the predominant isoform in skeletal muscle (12–16). The Lmods share ∼40% sequence identity at the protein level with the Tmods but do not contain a recognizable second tropomyosin-binding domain and have an additional C-terminal extension that includes a proline-rich region and an actin-binding Wiskott–Aldrich syndrome protein homology 2 (WH2) domain (12, 17). Lmod2 has been proposed to be the long-sought muscle actin filament nucleator because it robustly nucleates actin filament formation in vitro (because of its three actin-binding sites) and is reportedly required for proper sarcomere assembly in cultured cardiomyocytes (17). Like Tmod1, Lmod2 assembly at the pointed end of the thin filament requires association with tropomyosin; however unlike Tmod1, Lmod2 assembly also is dependent on contractility and the availability of polymerizable actin (18). Although part of the Tmod family of proteins, Lmod2 does not demonstrate actin filament-capping activity, and its overexpression displaces Tmod1; it is not known if this displacement is a direct or indirect effect (13). Nevertheless, Lmod2 overexpression results in the elongation of thin filaments in cells in culture (13). Limited data regarding the function of Lmod2 suggest it could play an important role in sarcomeric actin assembly, but the physiological function of Lmod2 has yet to be studied.Here we show that Lmod2 functions as an actin filament elongation factor in the heart. Our search for the mechanism by which Lmod2 functions revealed that Lmod2 promotes actin assembly and dynamics at the pointed end of the thin filament, is not necessary for myofibrillogenesis, but is required for thin filaments to attain a mature length. Our results also indicate that Lmod2 is essential for normal heart function and suggest that dysregulation of the thin filament length is causative for dilated cardiomyopathy (DCM).