A Microfacet‐based Hair Scattering Model

The development of scattering models and rendering algorithms for human hair remains an important area of research in computer graphics. Virtually all available models for scattering off hair or fur fibers are based on separable lobes, which bring practical advantages in importance sampling, but do not represent physically-plausible microgeometry. In this paper, we contribute the first microfacet-based hair scattering model. Based on a rough cylinder geometry with tilted cuticle scales, our far-field model is non-separable by nature, yet allows accurate importance sampling. Additional benefits include support for elliptical hair cross-sections and an analytical solution for the reflected lobe using the GGX distribution. We show that our model captures glint-like forward scattering features in the R lobe that have been observed before but not properly explained

Complement blockade with eculizumab to treat acute symptomatic humoral rejection after heart transplantation.

Antibody-mediated rejection (AMR) is a major barrier preventing successful discordant organ xenotransplantation, but it also occurs in allotransplantation due to anti-HLA antibodies. Symptomatic acute AMR is rare after heart allograft but carries a high risk of mortality, especially >1 year after transplant. As complement activation may play a major role in mediating tissue injury in acute AMR, drugs blocking the terminal complement cascade like eculizumab may be useful, particularly since "standards of care" like plasmapheresis are not based on strong evidence. Eculizumab was successfully used to treat early acute kidney AMR, a typical condition of "active AMR," but showed mitigated results in late AMR, where "chronic active" lesions are more prevalent. Here, we report the case of a heart recipient who presented with acute heart failure due to late acute AMR with eight de novo donor-specific anti-HLA antibodies (DSA), and who fully recovered allograft function and completely cleared DSA following plasmapheresis-free upfront eculizumab administration in addition to thymoglobulin, intravenous immunoglobulins (IVIG), and rituximab. Several clinical (acute onset, abrupt and severe loss of graft function), biological (sudden high-level production of DSA), and pathological features (microvascular injury, C4d deposits) of this cardiac recipient are shared with early kidney AMR and may indicate a strong role of complement in the pathogenesis of acute graft injury that may respond to drugs like eculizumab. Terminal complement blockade should be further explored to treat acute AMR in recipients of heart allografts and possibly also in recipients of discordant xenografts in the future

Adrenergic Receptor Polymorphism and Maximal Exercise Capacity after Orthotopic Heart Transplantation.

BACKGROUND: Maximal exercise capacity after heart transplantion (HTx) is reduced to the 50-70% level of healthy controls when assessed by cardiopulmonary exercise testing (CPET) despite of normal left ventricular function of the donor heart. This study investigates the role of donor heart β1 and β2- adrenergic receptor (AR) polymorphisms for maximal exercise capacity after orthotopic HTx. METHODS: CPET measured peak VO2 as outcome parameter for maximal exercise in HTx recipients ≥9 months and ≤4 years post-transplant (n = 41; mean peak VO2: 57±15% of predicted value). Donor hearts were genotyped for polymorphisms of the β1-AR (Ser49Gly, Arg389Gly) and the β2-AR (Arg16Gly, Gln27Glu). Circumferential shortening of the left ventricle was measured using magnetic resonance based CSPAMM tagging. RESULTS: Peak VO2 was higher in donor hearts expressing the β1-Ser49Ser alleles when compared with β1-Gly49 carriers (60±15% vs. 47±10% of the predicted value; p = 0.015), and by trend in cardiac allografts with the β1-AR Gly389Gly vs. β1-Arg389 (61±15% vs. 54±14%, p = 0.093). Peak VO2 was highest for the haplotype Ser49Ser-Gly389, and decreased progressively for Ser49Ser-Arg389Arg > 49Gly-389Gly > 49Gly-Arg389Arg (adjusted R2 = 0.56, p = 0.003). Peak VO2 was not different for the tested β2-AR polymorphisms. Independent predictors of peak VO2 (adjusted R2 = 0.55) were β1-AR Ser49Gly SNP (p = 0.005), heart rate increase (p = 0.016), and peak systolic blood pressure (p = 0.031). Left ventricular (LV) motion kinetics as measured by cardiac MRI CSPAMM tagging at rest was not different between carriers and non-carriers of the β1-AR Gly49allele. CONCLUSION: Similar LV cardiac motion kinetics at rest in donor hearts carrying either β1-AR Gly49 or β1-Ser49Ser variant suggests exercise-induced desensitization and down-regulation of the β1-AR Gly49 variant as relevant pathomechanism for reduced peak VO2 in β1-AR Gly49 carriers

Three-Dimensional Self-Navigated T2 Mapping for the Detection of Acute Cellular Rejection After Orthotopic Heart Transplantation.

T2 mapping is a magnetic resonance imaging technique measuring T2 relaxation time, which increases with the myocardial tissue water content. Myocardial edema is a component of acute cellular rejection (ACR) after heart transplantation. This pilot study compares in heart transplantation recipients a novel high resolution 3-dimensional (3D) T2-mapping technique with standard 2-dimensional (2D) T2-mapping for ACR detection. Consecutive asymptomatic patients (n = 26) underwent both 3D T2 mapping and reference 2D T2 mapping magnetic resonance imaging on the day of endomyocardial biopsy (EMB). 3D T2 maps were obtained at an isotropic spatial resolution of 1.72 mm (voxel volume 5.1 mm(3)). 2D and 3D maps were matched anatomically, and maximum segmental T2 values were compared blinded to EMB results. In addition, all 3D T2 maps were rendered as 3D images and inspected for foci of T2 elevation. T2 values of segments from 2D and reformatted 3D T2 maps agreed (p > 0.5). The highest 2D segmental T2 values were 49.9 ± 4.0 ms (no ACR = 0R, n = 18), 48.9 ± 0.8 ms (mild ACR = 1R, n = 3), and 65.0 ms (moderate ACR = 2R). Rendered 3D T2 maps of cases with 1R showed foci with significantly elevated T2 signal (T2 = 58.2 ± 3.6 ms); 5 cases (28%) in the 0R group showed foci with increased T2 values (>2 SD above adjacent tissue) that were not visible on the 2D T2 maps. This pilot study in a small cohort suggests equivalency of standard segmental analysis between 3D and 2D T2-mapping. 3D T2 mapping provides a spatial resolution that permits detection of foci with elevated T2 in patients with mild ACR

Non-severe aortic regurgitation increases short-term mortality in acute heart failure with preserved ejection fraction.

Mild or moderate aortic regurgitation (AR) has only little effect on cardiovascular outcome in people with normal left ventricular ejection fraction (EF); therefore, it is not perceived as a major clinical problem. This study investigates whether mild or moderate AR is associated with increased short-term mortality in patients hospitalized for treatment of acute heart failure (AHF) and whether mild or moderate AR impacts differently on short-term mortality in AHF patients with reduced EF (AHFrEF), mid-range EF (AHFmrEF), or preserved EF (AHFpEF). This mono-centric study included 505 consecutive adult patients hospitalized for de novo or worsening chronic HF not related to acute ischaemia or severe valvular pathology in the echocardiogram at index hospitalization. Cox regression analysis studied the impact of AR on all-cause mortality (ACM) over the 150 days' study period. Mild or moderate AR was associated with increased ACM (HR 1.75 [95% CI: 1.1-2.7]; P = 0.009). The prevalence of mild or moderate AR in the study population was 42% and not significantly different between AHFpEF (n = 227), AHFmrEF (n = 86), and AHFrEF (n = 192) study participants (37.9% vs. 50.0% vs. 42.7%; P = 0.144). In AHFpEF patients, the age-adjusted hazard for ACM was increased in patients with AR compared with patients without AR (HR 2.17 [95% CI: 1.1-4.2]; P = 0.002). The age-adjusted hazard for ACM was increased by a trend in AHFmrEF with AR (HR 7.11, [95% CI: 0.9-57.8]; P = 0.067) and not different between the AHFrEF groups (HR 0.95 [95% CI: 0.5-1.8]; P = 0.875). Mild or moderate AR increased ACM only in AHFpEF patients, highlighting a distinct clinical relevance

Red cell distribution width and mortality in acute heart failure patients with preserved and reduced ejection fraction.

Elevated red blood cell distribution width (RDW) is a valid predictor of outcome in acute heart failure (AHF). It is unknown whether elevated RDW remains predictive in AHF patients with either preserved left ventricular ejection fraction (LVEF) ≥50% or reduced LVEF (<50%). Prospective local registry including 402 consecutive hospitalized AHF patients without acute coronary syndrome or need of intensive care. The primary outcome was all-cause mortality (ACM) at 1 year after admission. Demographic and clinical data derive from admission, echocardiographic examinations (n = 269; 67%) from hospitalization. The Cox proportional hazard model including all patients (P < 0.001) was adjusted for age, gender, and RDW quartiles. Independent predictors of 1-year ACM were cardiogenic shock (HR 2.86; CI: 1.3-6.4), male sex (HR 1.9; CI: 1.2-2.9), high RDW quartile (HR 1.66; CI: 1.02-2.8), chronic HF (HR 1.61; CI: 1.05-2.5), valvular heart disease (HR 1.61; CI: 1.09-2.4), increased diastolic blood pressure (HR 1.02 per mmHg; CI: 1.01-1.03), increasing age (HR 1.04 by year; CI: 1.02-1.07), platelet count (HR 1.002 per G/l; CI: 1.0-1.004), systolic blood pressure (HR 0.99 per mmHg; CI: 0.98-0.99), and weight (HR 0.98 per kg; CI: 0.97-0.99). A total of 114 patients (28.4%) died within the first year; ACM of all patients increased with quartiles of rising RDW (χ(2) 18; P < 0.001). ACM was not different between RDW quartiles of patients with reduced LVEF (n = 153; χ(2) 6.6; P = 0.084). In AHF with LVEF ≥50% the probability of ACM increased with rising RDW (n = 116; χ(2) 9.9; P = 0.0195). High RDW is associated with increased ACM in AHF patients with preserved but not with reduced LVEF in this study population

Acquisition and analysis of bispectral bidirectional reflectance distribution functions

In fluorescent materials, energy from a certain band of incident wavelengths is reflected or reradiated at larger wavelengths, i.e. with lower energy per photon. While fluorescent materials are common in everyday life, they have received little attention in computer graphics. Especially, no bidirectional reflectance measurements of fluorescent materials have been available so far. In this paper, we develop the concept of a bispectral BRDF, which extends the well-known concept of the bidirectional reflectance distribution function (BRDF) to account for energy transfer between wavelengths. Using a bidirectional and bispectral measurement setup, we acquire reflectance data of a variety of fluorescent materials, including vehicle paints, paper and fabric. We show bispectral renderings of the measured data and compare them with reduced versions of the bispectral BRDF, including the traditional RGB vector valued BRDF. Principal component analysis of the measured data reveals that for some materials the fluorescent reradiation spectrum changes considerably over the range of directions. We further show that bispectral BRDFs can be efficiently acquired using an acquisition strategy based on principal components

Already low drug dose antagonism of the renin-angiotensin aldosterone system decreases 1-year mortality and rehospitalization in old heart failure patients

Hospitalization for heart failure treatment (HHF) is an incisive event in the course of HF. Today, the large majority of HHF patients is ≥ 65 years and discharge HF drugs are most often not applied at dose levels acknowledged to provide prognostic benefit. This study therefore aims to investigate the treatment effect size of discharge HF drugs in old HHF patients. Drugs are analyzed according to pharmacological class. Individual discharge HF drug dose is reported as percentage of guidelines-recommended target dose. Primary endpoint was 1-year all-cause mortality (ACM) after discharge; the secondary endpoint combined 1-year ACM and first cardiovascular hospitalization within 1 year after discharge. Comparison between 65-80 years and > 80 years old study participants tested the relative treatment effect size as a function of respective age group. The 875 consecutive HHF patients had a median age of 82 years [76-87 years]; 48.6 % were females. Betablocker and diuretic treatment did not change the incidence of endpoints. Inhibition of the renin-angiotensin system (RASi), when compared to no treatment, decreased the incidence of endpoints both at the 1-25 % and the > 25 % target dose level. Antagonists of the mineralocorticoid receptor (MRA), when compared to no treatment, decreased the secondary endpoint at the 1-25 % target dose level but not at the > 25 % target dose level. The relative treatment effect size of RASi or MRA corresponded between the age strata for both endpoints. Low-dose RASi and MRA had beneficial effects in these old HHF patients