Humoral Rejection in Cardiac Transplantation: Management of Antibody-Mediated Rejection

After a successful heart transplantation, fundamental keys to achieve good results in the long term are to establish immunosuppressive therapy in the postoperative period in an appropriate manner and to ensure continuity of follow-ups. Despite the fact that these stages are maintained perfectly, patients may face one or more rejection episodes. T-cell-mediated acute cellular rejection of the cardiac allograft has well-established treatment algorithms, whereas antibody-mediated rejection (AMR) is challenging to diagnose, and its treatment varies between centers. Investigators reported that AMR is among the most important factors to improving long-term outcomes. Improved understanding of the roles of acute and chronic AMR has evolved in recent years following a major progress in the technical ability to detect and quantify recipient antihuman leukocyte antigen (HLA) antibody production. Recently, a study of the immunobiology of B cells and plasma cells that pertains to allograft rejection and tolerance has emerged. There are some questions regarding the classification of AMR, the diagnostic approaches, and the treatment strategies for managing. In this chapter, we are discuss the effector mechanisms that are used by antibodies to eliminate antigens and clinical experience about AMR and its treatment with a discussion about the latest articles

Prognostic Value of Neutrophil to Lymphocyte Ratio and Platelet to Lymphocyte Ratio in Lung Cancer

Numerous studies determined that the neutrophil/lymphocyte (NLR) and platelet/lymphocyte ratios (PLR) had prognostic value in several cancer types. This study aimed to evaluate the relationship between NLR and PLR values with the survival time of lung cancer patients. Patients diagnosed with lung cancer between January 2014 and December 2016, were retrospectively evaluated. Demographic characteristics, disease stages, laboratory parameters recorded, and the relationship of NLR and PLR values with the survival time and the disease stage evaluated. NLR and PLR were categorized into two groups. SPSS 17.0 software package was used for the statistical analysis. ROC analysis, Student T-test, Chi-square, and Mann-Whitney U test were used. Mean age of 62±8 years were included in the study. In the NSCLC group, the average NLR and PLR values were 4±3.35 and 194.6±144.4 respectively. Regarding the NSCLC group, the overall survival time was shorter in the subgroup with an NLR >3.43 (13.1 months) compared to the subgroup with an NLR ≤3.43 (24.3 months). The mean survival time was shorter in the group with a PLR > 136.9 compared to the group with a PLR ≤136.9 (15.9 and 24.6 months respectively). Subgroups consisting of survivors and non-survivors in the NSCLC group showed a statistically significant difference considering neutrophil and lymphocyte count, CRP, NLR, and PLR values (

Creatinine Clearance in Patients with Obstructive Sleep Apnea

During an apnea, hemodynamic complications such as hypoxemia, a rise in systemic and pulmonary arterial pressure, and changes in heart rate occur in patients with obstructive sleep apnea (OSA). Potential mechanisms of OSA-associated renal dysfunction include renal hypoxia, hypertension, endothelial dysfunction. Hypertension is common in patients with OSA. This study aims to assess OSA patients' renal functions and investigate the creatinine clearance (CC) values across OSA patients with and without hypertension. The study included 530 individuals with OSA and 60 individuals with an apnea-hypopnea index (AHI) of 0.05). A statistically significant difference was detected in urea and creatinine levels between the OSA and control groups (p=0.005; p=0.012). Creatinine clearance decreases in patients with OSA in the presence of HT. Patients with OSA often experience cardiovascular disorders, and glomerular endothelial dysfunction occurs in OSA patients

Assessment of Knowledge-Based Planning for Prostate Intensity Modulated Proton Therapy

Purpose: To assess the performance of a proton-specific knowledge based planning (KBPP) model in creation of robustly optimized intensity-modulated proton therapy (IMPT) plans for treatment of patients with prostate cancer. Materials and Methods: Forty-five patients with localized prostate cancer, who had previously been treated with volumetric modulated arc therapy, were selected and replanned with robustly optimized IMPT. A KBPP model was generated from the results of 30 of the patients, and the remaining 15 patient results were used for validation. The KBPP model quality and accuracy were evaluated with the model-provided organ-at-risk regression plots and metrics. The KBPP quality was also assessed through comparison of expert and KBPP-generated IMPT plans for target coverage and organ-at-risk sparing. Results: The resulting R (2) (mean ± SD, 0.87 ± 0.07) between dosimetric and geometric features, as well as the χ(2) test (1.17 ± 0.07) between the original and estimated data, showed the model had good quality. All the KBPP plans were clinically acceptable. Compared with the expert plans, the KBPP plans had marginally higher dose-volume indices for the rectum V65Gy (0.8% ± 2.94%), but delivered a lower dose to the bladder (-1.06% ± 2.9% for bladder V65Gy). In addition, KBPP plans achieved lower hotspot (-0.67Gy ± 2.17Gy) and lower integral dose (-0.09Gy ± 0.3Gy) than the expert plans did. Moreover, the KBPP generated better plans that demonstrated slightly greater clinical target volume V95 (0.1% ± 0.68%) and lower homogeneity index (-1.13 ± 2.34). Conclusions: The results demonstrated that robustly optimized IMPT plans created by the KBPP model are of high quality and are comparable to expert plans. Furthermore, the KBPP model can generate more-robust and more-homogenous plans compared with those of expert plans. More studies need to be done for the validation of the proton KBPP model at more-complicated treatment sites

The effect of CRP/albumin ratio on prognosis of hospitalized patients due to COVID-19

Introduction: COVID-19 disease caused by the SARS-Cov-2 virus is characterized by clinical spectra of varying severity. Coagulopathy and inflammation are the most important factors associated with COVID-19 severity. The use of a biomarker of inflammation and coagulation factors has not yet been clarified. The present study aimed to examine the role of CRP/Albumin, an inflammation marker, in predicting the course of COVID-19 disease.Methods: The Demographic, laboratory, and prognosis of 457 patients who were hospitalized during the COVID-19 pandemic service between April and May 2020 were analyzed retrospectively. The relationship between the patients' CRP/Albumin ratio and disease severity, length of hospital stays, and prognosis were analyzed.Results: The rate of hospitalization in the intensive care unit was 10.5% (n=48), mechanical ventilation was 8.1% (n=37), and death was 1.3% (n=6). The CRP/albumin ratio was statistically higher in those with lung infiltration (p=0.005), those who were taken to the intensive care unit (p lt;0.001), and those who needed mechanical ventilation (p lt;0.001). A positive significant correlation was found between the length of hospital stay and the CRP/albumin ratio(r=0.412, p lt; 0.001).Conclusion: The CRP/Albumin ratio is thought to be an auxiliary marker for doctors in the early transfer of patients to the intensive care unit, the early detection of those in need of MV, and the determination of lung infiltration.Keywords: COVID-19, CRP/albumin ratio, prognosi

Comparison of the efficacy of once- and twice-daily colchicine dosage in pediatric patients with familial Mediterranean fever - a randomized controlled noninferiority trial

Background: In this study, we examined the efficacy and safety of a once-daily dosage schema of colchicine compared with a twice-daily dosage schema in pediatric patients with familial Mediterranean fever (FMF). Methods: In this 24-week, multicenter, randomized controlled noninferiority trial, pediatric patients newly diagnosed with FMF carrying a homozygous or compound heterozygous mutation and not receiving any treatment were included. Patients were randomly assigned using a block randomization method to receive treatment with a once- or twice-daily dosage. Clinical and laboratory characteristics and medication side effects were recorded and compared between groups. The study was carried out in compliance with Good Clinical Practice and the Consolidated Standards for Reporting of Trials (CONSORT) statement. Results: A total of 92 patients were selected, and 79 patients completed the study. There were 42 patients in the once-daily dosage group and 37 in the twice-daily dosage group. The results indicated that the once-daily dosage was not inferior to the twice-daily dosage regarding decrease in attack frequency and duration as well as improvement in clinical findings and Mor severity scores. Alterations in laboratory findings indicating inflammation, such as erythrocyte sedimentation rate, C-reactive protein, and serum amyloid A, were similar in both groups. The rates of drug side effects were similar between the once- and twice-daily dosage groups, implying comparable safety of colchicine, with the exception of diarrhea, which was slightly higher in the once-daily dosage group. Conclusions: Using colchicine with either a once- or twice-daily dosage provides similar clinical and laboratory improvements. Considering both efficacy and safety, colchicine can be prescribed with a once-daily dosage. Trial Registration ID: ClinicalTrials.gov identifier NCT02602028. Registered 5 November 2015

IMRT commissioning: multiple institution planning and dosimetry comparisons, a report from AAPM Task Group 119.

AAPM Task Group 119 has produced quantitative confidence limits as baseline expectation values for IMRT commissioning. A set of test cases was developed to assess the overall accuracy of planning and delivery of IMRT treatments. Each test uses contours of targets and avoidance structures drawn within rectangular phantoms. These tests were planned, delivered, measured, and analyzed by nine facilities using a variety of IMRT planning and delivery systems. Each facility had passed the Radiological Physics Center credentialing tests for IMRT. The agreement between the planned and measured doses was determined using ion chamber dosimetry in high and low dose regions, film dosimetry on coronal planes in the phantom with all fields delivered, and planar dosimetry for each field measured perpendicular to the central axis. The planar dose distributions were assessed using gamma criteria of 3%/3 mm. The mean values and standard deviations were used to develop confidence limits for the test results using the concept confidence limit = /mean/ + 1.96sigma. Other facilities can use the test protocol and results as a basis for comparison to this group. Locally derived confidence limits that substantially exceed these baseline values may indicate the need for improved IMRT commissioning

Multiple Compton scatter camera for gamma ray imaging.

A gamma ray imaging camera which utilizes multiple Compton scatterings has been investigated for technological feasibility. The analytical calculations for choosing an appropriate detector layer thickness were performed for both germanium and silicon. Silicon strip detectors were chosen for our proposed design because of their ability to operate at room temperature and their excellent position and energy resolution. The proposed design has 20 layers of 0.1 cm thick, 4 inch diameter silicon strip detectors surrounded with a CsI annular side counter. Monte Carlo simulations were performed for the proposed design over the range of 150-1000 keV. The proposed design gave angular resolutions around 2-6\sp\circ assuming 1 keV for the noise term with efficiencies of 8-26%, excluding electron escape from the detector layers and double Compton scatterings within a detector layer, over the energy range of 150-1000 keV. Two and three dimensional source reconstruction techniques for Compton scatter cameras have also been investigated. The intersection of the cones, the event circle, and the maximum likelihood methods were implemented. The maximum likelihood method produced much better images compared to the intersection of the cones and the event circle method. A new three-dimensional source reconstruction method was also derived for Compton scatter cameras. The method uses parametric line equations and the shortest distance between the lines as a convergence criteria. Although this simple technique did produce reasonable images for simple source geometries, the images can be also used as initial guesses for more sophisticated iterative reconstruction algorithms, such as ART (Algebraic Reconstruction Technique), SIRT (Simultaneous Iterative Reconstruction Technique), and ML (Maximum Likelihood). The influence of gamma ray polarization on multiple Compton scatterings was investigated and implemented in the Integrated Tiger Series of Photon/Electron Monte Carlo codes. A new source reconstruction method which uses the polarization dependence of double Compton scattering was also derived and tested. This method reduces the azimuthal ambiguity associated with determining the incoming gamma ray direction.Ph.D.Nuclear EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/103569/1/9332047.pdfDescription of 9332047.pdf : Restricted to UM users only

Surface and build-up region dosimetry for obliquely incident intensity modulated radiotherapy 6 MV x rays

This study investigates the surface dose and build-up region dosimetry for oblique IMRT beams. The dependence of surface and build-up region doses of 0° (perpendicular incidence) and 75° (oblique incidence) IMRT fields on field size was measured and compared with open field dosimetry. Measurements were performed using a parallel-plate chamber and KODAK EDR2 films in a polystyrene phantom for a 6  cm ×6  cm and a 12  cm ×12  cm , 6 MV photon beam at depths of 0 mm (surface) through d max . Data were normalized to the d max value of each field. Four intensity modulated delivery patterns were created and delivered using step-and-shoot IMRT: (1) six static 1  cm ×6  cm strips ( IMRT strip ), (2) 12 static 1  cm ×12  cm strips ( IMRT strip ), (3) intensity modulated beam patterns created by using the inverse planning optimization software ( IMRT opt ) for 6  cm ×6  cm , and (4) IMRT opt for 12  cm ×12  cm field sizes. The percent depth doses (PDDs) of 0°, 6  cm ×6  cm IMRT strip beam at the surface and 5 mm were lower by 8.8% and 1.6%, respectively, compared to the open field. The PDDs of 75°, 6  cm ×6  cm IMRT strip beam at the surface and 5 mm were lower by 6.7% and 2.4%, respectively, compared to the open field. This study showed that IMRT itself is not contributing to greater skin doses

El analisis estructural semi-rigido: definicion, camp y mood de applicacion

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