Development of a Computationally Efficient Full Human Body Finite Element Model

<div><p><b>Introduction:</b> A simplified and computationally efficient human body finite element model is presented. The model complements the Global Human Body Models Consortium (GHBMC) detailed 50th percentile occupant (M50-O) by providing kinematic and kinetic data with a significantly reduced run time using the same body habitus.</p><p><b>Methods:</b> The simplified occupant model (M50-OS) was developed using the same source geometry as the M50-O. Though some meshed components were preserved, the total element count was reduced by remeshing, homogenizing, or in some cases omitting structures that are explicitly contained in the M50-O. Bones are included as rigid bodies, with the exception of the ribs, which are deformable but were remeshed to a coarser element density than the M50-O. Material models for all deformable components were drawn from the biomechanics literature. Kinematic joints were implemented at major articulations (shoulder, elbow, wrist, hip, knee, and ankle) with moment vs. angle relationships from the literature included for the knee and ankle. The brain of the detailed model was inserted within the skull of the simplified model, and kinematics and strain patterns are compared.</p><p><b>Results:</b> The M50-OS model has 11 contacts and 354,000 elements; in contrast, the M50-O model has 447 contacts and 2.2 million elements. The model can be repositioned without requiring simulation. Thirteen validation and robustness simulations were completed. This included denuded rib compression at 7 discrete sites, 5 rigid body impacts, and one sled simulation. Denuded tests showed a good match to the experimental data of force vs. deflection slopes. The frontal rigid chest impact simulation produced a peak force and deflection within the corridor of 4.63 kN and 31.2%, respectively. Similar results vs. experimental data (peak forces of 5.19 and 8.71 kN) were found for an abdominal bar impact and lateral sled test, respectively. A lateral plate impact at 12 m/s exhibited a peak of roughly 20 kN (due to stiff foam used around the shoulder) but a more biofidelic response immediately afterward, plateauing at 9 kN at 12 ms. Results from a frontal sled simulation showed that reaction forces and kinematic trends matched experimental results well. The robustness test demonstrated that peak femur loads were nearly identical to the M50-O model. Use of the detailed model brain within the simplified model demonstrated a paradigm for using the M50-OS to leverage aspects of the M50-O. Strain patterns for the 2 models showed consistent patterns but greater strains in the detailed model, with deviations thought to be the result of slightly different kinematics between models. The M50-OS with the deformable skull and brain exhibited a run time 4.75 faster than the M50-O on the same hardware.</p><p><b>Conclusions:</b> The simplified GHBMC model is intended to complement rather than replace the detailed M50-O model. It exhibited, on average, a 35-fold reduction in run time for a set of rigid impacts. The model can be used in a modular fashion with the M50-O and more broadly can be used as a platform for parametric studies or studies focused on specific body regions.</p></div

Urine heparanase levels inversely associate with eGFR in kidney transplanted patients.

<p>Heparanase/creatinine levels are plotted in relation to eGFR values. Note significant inverse association of urine heparanase with eGFR (p = 0.035, r = −0.2224) (Spearman nonparametric correlation test).</p

Heparanase levels in the urine and blood of study subjects.

<p>Determination of heparanase levels in urine (A, B) and plasma (C, D) of individuals from the study groups. Shown are average (±SE; A, C) and median (B, D) values quantified by an ELISA method, as described under ‘Materials and Methods’.</p

Characteristics of study population by diagnostic group.

<p>Data is presented as mean±S.D and/or as median values (min-max).</p>a<p>One-way analysis of variance (ANOVA) or the Kruskal-Wallis test were used to compare continuous variables across patient category (control, CKD and transplanted), followed post hoc by Bonferroni's pair wise analysis or the Mann-Whitney U-test, as appropriate.</p>b<p>Estimated glomerular filtration rate (eGFR) was determined by the abbreviated Modification of Diet in Renal Disease (MDRD) equation <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044076#pone.0044076-Levey1" target="_blank">[26]</a>.</p

Log transformed urinary heparanase/creatinine and log transformed urinary protein/creatinine.

<p>Log transformed urinary heparanase/creatinine and log transformed urinary protein/creatinine.</p

Association between log transformed urine heparanase/creatinine levels and studied parameters in transplanted (n = 100) and CKD (n = 41) patients^a.

a<p>Pearson's or Spearman's correlation coefficients are presented within CKD and transplant groups, respectively.</p>b<p>Estimated glomerular filtration rate (eGFR) was determined by the abbreviated Modification of Diet in Renal Disease (MDRD) equation <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044076#pone.0044076-Levey1" target="_blank">[26]</a>.</p

Efficacy and safety of sequential versus quadruple therapy as second-line treatment for helicobacter pylori infection—A randomized controlled trial

<div><p>Background and aims</p><p>Quadruple therapy is recommended as second-line treatment for <i>Helicobacter pylori</i> eradication failure. However, high cost, multiple side effects, and low adherence rates are major drawbacks to its routine use. Our aim was to compare the efficacy and safety of sequential versus quadruple regimens as second line treatment for persistent <i>Helicobacter pylori</i> infection.</p><p>Methods</p><p>Prospective, randomized, open label trial was conducted at a large academic, tertiary care center in Israel. Patients who previously failed a standard triple treatment eradication course were randomly assigned (1:1) to receive a 10-day sequential therapy course, or a 14-day quadruple regimen. Compliance and adverse events were evaluated by telephone questionnaires. The primary endpoint for analysis was the rate of <i>Helicobacter pylori</i> eradication as defined by either a negative 13C-urea breath-test, or stool antigen test, 4–16 weeks after treatment assessed under the non-inferiority hypothesis. The trial was terminated prematurely due to low recruitment rates.</p><p>See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0183302#pone.0183302.s001" target="_blank">S1 Checklist</a> for CONSORT checklist.</p><p>Results</p><p>One hundred and one patients were randomized. Per modified intention-to-treat analysis, eradication rate was 49% in the sequential versus 42.5% in the quadruple regimen group (p-value for non-inferiority 0.02). Forty-two (84.0%) versus 33 (64.7%) patients completed treatment in the sequential and quadruple groups respectively (p 0.027). Gastrointestinal side effects were more common in the quadruple regimen group.</p><p>Conclusion</p><p>Sequential treatment when used as a second line regimen, was non-inferior to the standard of care quadruple regimen in achieving <i>Helicobacter pylori</i> eradication, and was associated with better compliance and fewer adverse effects. Both treatment protocols failed to show an adequate eradication rate in the population of Southern Israel.</p><p>Trial registration</p><p>ClinicalTrials.gov <a href="https://clinicaltrials.gov/ct2/show/NCT01481844" target="_blank">NCT01481844</a></p></div

Comparison of side effect profile between the 2 regimens.

<p>Comparison of side effect profile between the 2 regimens.</p

Patient baseline characteristics.

<p>Patient baseline characteristics.</p

Comparison of outcomes between the two treatments arms.

<p>Comparison of outcomes between the two treatments arms.</p