Systems change in the context of an initiative to scale up Housing First in Canada

In this study, we examine changes in the homeless‐serving system in the context of a training and technical assistance initiative to scale up Housing First (HF) in 6 Canadian communities. Based on qualitative data from focus groups and individual interviews with key stakeholders (k = 7, n = 35) and field notes gathered over a 3‐year period (n = 146), we found 2 main system changes: (a) changes in the capacity of the service delivery system at multiple levels of analysis (from individual to policy) to implement HF, and (b) changes in the coordination of parts of the service delivery system and collaboration among local stakeholders to enhance HF implementation. These changes were facilitated or constrained by the larger context of evidence, climate, policy, and funding. The findings were discussed in terms of systems change theory and implications for transformative systems change in the mental health and homelessness sectors.     

Comparative Analysis of Liver Injury-Associated Cytokines in Acute Hepatitis A and B

PurposeAcute hepatitis A (AHA) and acute hepatitis B (AHB) are caused by an acute infection of the hepatitis A virus and the hepatitis B virus, respectively. In both AHA and AHB, liver injury is known to be mediated by immune cells and cytokines. In this study, we measured serum levels of various cytokines and T-cell cytotoxic proteins in patients with AHA or AHB to identify liver injury-associated cytokines.ResultsInterleukin (IL)-18, IL-8, CXCL9, and CXCL10 were significantly elevated in both AHA and AHB. IL-6, IL-22, granzyme B, and soluble Fas ligand (sFasL) were elevated in AHA but not in AHB. In both AHA and AHB, the serum level of CXCL10 significantly correlated with the peak ALT level. Additionally, the serum level of granzyme B in AHA and the serum level of sFasL in AHB correlated with the peak ALT level.ConclusionWe identified cytokines and T-cell cytotoxic proteins associated with liver injury in AHA and AHB. These findings deepen the existing understanding of immunological mechanisms responsible for liver injury in acute viral hepatitis.     

Switchable S = 1/2 and J = 1/2 Rashba bands in ferroelectric halide perovskites

The Rashba effect is spin degeneracy lift originated from spin–orbit coupling under inversion symmetry breaking and has been intensively studied for spintronics applications. However, easily implementable methods and corresponding materials for directional controls of Rashba splitting are still lacking. Here, we propose organic–inorganic hybrid metal halide perovskites as 3D Rashba systems driven by bulk ferroelectricity. In these materials, it is shown that the helical direction of the angular momentum texture in the Rashba band can be controlled by external electric fields via ferroelectric switching. Our tight-binding analysis and first-principles calculations indicate that and Rashba bands directly coupled to ferroelectric polarization emerge at the valence and conduction band edges, respectively. The coexistence of two contrasting Rashba bands having different compositions of the spin and orbital angular momentum is a distinctive feature of these materials. With recent experimental evidence for the ferroelectric response, the halide perovskites will be, to our knowledge, the first practical realization of the ferroelectric-coupled Rashba effect, suggesting novel applications to spintronic devices.The Rashba effect has been widely investigated in 2D surfaces, interfaces, quantum wells, and 3D bulk systems (1–6). The essential requisite for the Rashba effect is that the spin degeneracy is lifted by the inversion symmetry-breaking (ISB) field in the presence of the spin–orbit coupling (SOC). To date, major concerns have focused on enlarging Rashba strength characterized by the Rashba coefficient (3, 5, 6). The controllability in the direction of the ISB field, on the other hand, has not been seriously considered. In a surface or an interface, the potential gradient generated by the structural inversion asymmetry results in the loss of controllability; the field direction is mainly fixed according to the preformed surface or interface configuration. The situation is similar in recently discovered 3D Rashba material BiTeI (6), because this material has the compositional ISB field between Te and I layers.Controlling the ISB field and ultimately Rashba-type band splitting can be achieved by using a novel ferroelectric Rashba material (7, 8). In a ferroelectric system, the bulk polarization controlled by external electric fields generates the ISB field. Therefore, the ferroelectric polarization directly couples to the spin splitting and the helical spin texture in the ferroelectric Rashba material, enabling the helicity reversal via the ferroelectric switching. Recent theoretical study suggested GeTe as a possible candidate for this mechanism, but the direct measurement of the ferroelectric polarization and switching is still missing due to the sizable conductivity of bulk GeTe (7, 8).We consider organic–inorganic hybrid metal halide perovskites as promising ferroelectric Rashba materials. The general formula for this material class is where , i.e., methylammonium (MA); M = Pb and Sn; and X = I and Br. The materials have several advantages over GeTe. Firstly, polar distortions and ferroelectric responses in the halide perovskite have been clearly observed in experiments (9, 10). On the other hand, GeTe inevitably generates Ge vacancies to give considerable bulk conductivity, which in turn hinders the polarization switching (11). Secondly, unlike the multiple band edges and strong hexagonal warping in GeTe (7, 8), the band edge states of the halide perovskites lie at a single point in the Brillouin zone with nearly isotropic Rashba bands. Thus, the halide perovskites have ideal Rashba-split bands with proper material quality. Finally, whereas GeTe has an indirect band gap (11), the halide perovskites have a direct one. This direct gap becomes important when we consider the transition between the valence and conduction bands in optical devices.Interestingly, the above halide perovskite series has two contrasting types of Rashba bands simultaneously: the and Rashba bands at the valence and conduction bands, respectively (Fig. 1). This originates from the different band characters in terms of the angular momentum at the valance and conduction band edges common in halide perovskite compounds (12). The angular momentum character of the individual band can be affected by relative energy scales of the crystal field and SOC; the crystal field quenches orbital degrees of freedom, whereas SOC entangles spin and orbital degrees. Through the competition between the two energy scales, the band character on which the Rashba Hamiltonian is based can vary from the fully spin–orbital entangled total angular momentum state (J) to the spin state (S) (13), which causes a significant distinction in the angular momentum texture of the Rashba band.Open in a separate windowFig. 1.Schematic illustration of the switchable Rashba effect. The polarization-coupled Rashba-type band splitting of the and manifolds in hybrid metal halide perovskites.In this work, we examine the electronic structures of the hybrid metal halide perovskites as candidates for the ferroelectric Rashba materials. By constructing a minimal tight-binding (TB) model Hamiltonian, we can capture the key features of the band structures; the low-energy effective Hamiltonian gives rise to the ferroelectric-coupled and Rashba bands at the valence band maximum (VBM) and the conduction band minimum (CBM), respectively. The Rashba-type splitting of the fully spin–orbital-entangled subspace stems from the bandgap-independent intraorbital as well as the bandgap-dependent interorbital terms. On the contrary, Rashba splitting only consists of the interorbital term (14). We present several examples of possible ferroelectric Rashba materials (β-MAPbI₃, β-MASnI₃, and ortho-MASbBr₃) by adopting first-principles electronic structure calculations based on density functional theory. These halide perovskites are shown to have the characteristic features predicted in the TB model with the sizable Rashba coefficient . A different type of controllability on the relative helicity between the two Rashba bands is also discussed according to the positions of the lateral halide atoms.     

Dual Energy X-ray Absorptiometry and Bioimpedance Analysis are Clinically Useful for Measuring Muscle Mass in Kidney Transplant Recipients With Sarcopenia

Purpose

Computed tomography (CT) is considered the gold standard method for the diagnosis and characterization of sarcopenia. The aim of the present study was to determine the correlation between the volume of psoas muscle measured using CT and the measurement of muscle mass with dual energy X-ray absorptiometry (DXA) and bioimpedance analysis (BIA) in kidney transplant recipients.

Scalp Micropigmentation: A Concealer for Hair and Scalp Deformities

Background: Cosmetic deformities, resulting from some dermatologic diseases or deformities caused by hair restoration surgeries, have had few, if any, good, permanent solutions. Most of these patients have learned to live with their problems. Objective: A cosmetic tattoo technique has been developed to address unsightly scalp and hair conditions. Materials and Methods: The technique called scalp micropigmentation uses specialized techniques and conventional cosmetic tattoo instruments and pigments in a stippling pattern on the scalp. Results: A variety of alopecias, refractory to treatment and hair transplant deformities, impact millions of men and women. Many of these deformities can be concealed with scalp micropigmentation, making the deformities minimally detectable. Included are the results of treatment. Patient satisfaction is very high. Conclusion: Scalp micropigmentation offers a good nonsurgical alternative treatment for hair and scalp deformities. This paper demonstrates scalp micropigmentation results and discusses the histology, physiology, and pathology of tattoo pigments in the skin. The regulation of the tattoo process by the United States Food and Drug Administration and state governments is summarized. Unlike medical devices, scalp micropigmentation offers a tattoo-based, non-medical “cover-up” that effectively hides unsightly conditions on the scalp and creates the illusion of thicker hair. The authors believe that scalp micropigmentation is destined to become a standardized offering for physicians specializing in cosmetic office procedures.There are millions of men and women who have cosmetic problems with their scalps and hair resulting from dermatologic and/or genetic conditions, such as intractable alopecia areata or female genetic balding. There are also iatrogenic deformities in millions of men from hair restoration procedures done between the 1950s and 1990s, reflecting crude techniques of that period and scars from strip harvesting. Since hair loss is frequently a progressive process, genetic and iatrogenic conditions often become more pronounced over time. Scalp micropigmentation (SMP) uses a tattoo in a stippling pattern that mimics hair follicles that are cut close to the scalp.1,2 This relatively new technique can significantly address the cosmetic problems derived from the conditions noted above.The tattoo industry is in the midst of a cultural expansion, growing from 14 percent in 2008 to 21 percent in 2012,3 making SMP a more socially acceptable cosmetic solution for covering appropriate scalp and hair problems.This article discusses how the SMP process is used, demonstrates a variety of clinical applications, identifies challenges created by the technique, discusses the anatomy and histology of the tattoo pigment interactions with human physiology, and identifies some of the safety issues known today. The authors will show how SMP will have a great impact on people who, heretofore, have had no acceptable long-term solutions for hiding deformities created by a broad variety of diseases and traumas.     

Parametric imaging of myocardial blood flow with 15O-water and PET using the basis function method.

Regional myocardial blood flow (MBF) can be measured with 15O-water and PET using the 1-tissue-compartment model with perfusable tissue fraction, which provides an MBF value that is free from the partial-volume effect. Studies with 15O-water have several advantages, such as the ability to repeat a scan. However, because of the short scanning time and the small distribution volume of 15O-water in the myocardium, the image quality of 15O-water is limited, impeding the computation of MBF and perfusable tissue fraction at the voxel level. We implemented the basis function method for generating parametric images of MBF, perfusable tissue fraction, and arterial blood volume (Va) with 15O-water and PET. The basis function method linearizes the solution of the 1-tissue-compartment model, which results in a computationally much faster method than the conventional nonlinear least-squares fitting method in estimating the parameters. METHODS: To validate the basis function method, we performed a series of PET studies on miniature pigs (n = 7). After acquisition of the transmission scan for attenuation correction and the 15O-CO scan for obtaining the blood-pool image, repeated PET scans with 15O-water were obtained with varying doses of adenosine or CGS-21680 (selective adenosine A(2a) receptor agonist). MBF, perfusable tissue fraction, and Va values of the myocardial region for each scan were computed using the basis function method and the nonlinear least-squares method, and the parameters estimated by the 2 methods were compared. RESULTS: MBF images generated by the basis function method demonstrated an increase in blood flow after administration of adenosine or CGS-21680. The MBF values estimated by the basis function method and by the nonlinear least-squares method correlated strongly. CONCLUSION: The basis function method produces parametric images of MBF, perfusable tissue fraction, and Va with 15O-water and PET. These images will be useful in detecting regional myocardial perfusion abnormalities.     

Characterization of the effects of asparaginase from escherichia coli and a glutaminase-free asparaginase from vibrio succinogenes on specific cell-mediated cytotoxicity

Asparaginases isolated from Escherichia coli and Erwinia carotovora are effective in the treatment of acute lymphoblastic leukemia in man. During treatment with either of these enzymes, patients frequently experience pronounced toxicity, including liver and pancreatic dysfunction and immunosuppression. The capabilities of these enzymes to hydrolyze L-glutamine, an important amino acid in mammalian intermediary metabolism, have led investigators to suggest that the glutaminase activity may be responsible for the observed toxicities. Unlike other asparaginases, an enzyme isolated in our laboratory from Vibrio succinogenes, has been shown to be a potent antilymphoma agent and to be highly specific for L-asparagine. Our previous work has established that the glutaminase-free asparaginase from V. succinogenes does not suppress the in vivo humoral or cell-mediated immune responses of mice to sheep red blood cells, whereas the E. coli enzyme abolishes these responses. In this study, we describe the mechanisms by which E. coli asparaginase suppresses specific antibody-dependent cell-mediated cytotoxicity. An analysis of the kinetics of appearance of the specific cell-mediated cytotoxic response of spleen cells after immunization with sheep red blood cells revealed that it paralleled the IgG plaque-forming cell response. In addition, 18-h culture supernatants from immune spleen cells conferred upon non-immune cells the ability to specifically lyse sheep red blood cells. Pretreatment of immune supernatants with protein A-Sepharose 4B absorbed out the soluble arming factor. An analysis of E. coli asparaginase-induced suppression of specific antibody-dependent cell-mediated cytotoxicity revealed that a decreased synthesis of specific IgG was responsible for the observed reduction in cytotoxic reactivity. When culture supernatants from spleen cells of immunized animals not treated with asparaginase were added to spleen cells from E. coli asparaginase-treated mice, however, there was an increased cytotoxic response. This suggested that there was an increase in the number or ratio of effector cells for the specific antibody-dependent cell-mediated cytotoxic response in spleens of enzyme-treated animals. Through the characterization of the immunosuppressive effects of two asparaginases—one having the catalytic capability to hydrolyze L-glutamine and the other lacking this catalytic activity—we now have evidence that the immunosuppressive effects of E. coli asparaginase on specific antibody-dependent cell-mediated cytotoxicity cannot be the result of asparagine depletion alone. Our data demonstrate that the glutaminase-free asparaginase from V. succinogenes is not immunosuppressive and suggest that an asparaginase with high substrate specificity for L-asparagine may be a safer treatment for leukemia patients.