Discordant pair analysis for sample efficient model evaluation.

We present a new technique for assessing the effectiveness of a classification algorithm using discordant pair analysis. This method utilizes a known performance baseline algorithm and a large unlabeled dataset with an assumed class distribution to obtain overall performance estimates by only assessing the subset of examples that the algorithms classify discordantly. Our approach offers an efficient way to evaluate the performance of an algorithm that minimizes the human adjudications needed while also maintaining precision in the evaluation and in some cases improving the evaluation quality by reducing human adjudication errors.

Cancer Mortality Among Solid Organ Transplant Recipients in the United States During 1987-2018.

Background: Solid organ transplant recipients (ie, "recipients") have elevated cancer risk and reduced survival after a cancer diagnosis. Evaluation of cancer mortality among recipients can facilitate improved outcomes from cancers arising before and after transplantation.

Methods: We linked the US transplant registry to the National Death Index to ascertain the causes of 126 474 deaths among 671 127 recipients (1987-2018).

Impact of COVID-19 pandemic on the size of US transplant waiting lists.

Background: More patients are waitlisted for solid organs than transplants are performed each year. The COVID-19 pandemic immediately increased waitlist mortality and decreased transplants and listings.

Methods: To calculate the number of candidate listings after the pandemic began and short-term changes that may affect waiting time, we conducted a Scientific Registry of Transplant Recipients surveillance study from January 1, 2012 to February 28, 2021.

Outcomes of living liver donor candidate evaluations in the Living Donor Collective pilot registry.

Background: To gather information on long-term outcomes after living donation, the Scientific Registry of Transplant Recipients (SRTR) conducted a pilot on the feasibility of establishing a comprehensive donor candidate registry.

Methods: A convenience sample of 6 US living liver donor programs evaluated 398 consecutive donor candidates in 2018, ending with the March 12, 2020, COVID-19 emergency.

Results: For 333/398 (83.

Outcomes of Living Kidney Donor Candidate Evaluations in the Living Donor Collective Pilot Registry.

Background: Gaps in our knowledge of long-term outcomes affect decision making for potential living kidney donors.

Methods: The Scientific Registry of Transplant Recipients was asked to determine the feasibility of a candidate registry.

Results: Ten living kidney donor programs evaluated 2107 consecutive kidney donor candidates; 2099 of 2107 (99.

Mortality among solid organ waitlist candidates during COVID-19 in the United States.

We examined the effects of COVID-19 on solid organ waiting list mortality in the United States and compared effects across patient demographics (e.g., race, age, and sex) and donation service areas.

The Centers for Medicare and Medicaid Services' proposed metrics for recertification of organ procurement organizations: Evaluation by the Scientific Registry of Transplant Recipients.

On December 23, 2019, the US Centers for Medicare and Medicaid Services proposed 2 new standards that organ procurement organizations (OPOs) must meet for recertification. An OPO's organ donation rate (deceased donors/potential donors) and organ transplant rate (organs transplanted/potential donors) must not fall significantly below the 75th percentile for rates among all OPOs. We examined how OPOs would have fared under the proposed performance standards in 2016-2017.

Fast, fully Bayesian spatiotemporal inference for fMRI data.

We propose a spatial Bayesian variable selection method for detecting blood oxygenation level dependent activation in functional magnetic resonance imaging (fMRI) data. Typical fMRI experiments generate large datasets that exhibit complex spatial and temporal dependence. Fitting a full statistical model to such data can be so computationally burdensome that many practitioners resort to fitting oversimplified models, which can lead to lower quality inference.

Impaired Bottom-Up Effective Connectivity Between Amygdala and Subgenual Anterior Cingulate Cortex in Unmedicated Adolescents with Major Depression: Results from a Dynamic Causal Modeling Analysis.

Major depressive disorder (MDD) is a significant contributor to lifetime disability and frequently emerges in adolescence, yet little is known about the neural mechanisms of MDD in adolescents. Dynamic causal modeling (DCM) analysis is an innovative tool that can shed light on neural network abnormalities. A DCM analysis was conducted to test several frontolimbic effective connectivity models in 27 adolescents with MDD and 21 healthy adolescents.

A Naive Bayes machine learning approach to risk prediction using censored, time-to-event data.

Predicting an individual's risk of experiencing a future clinical outcome is a statistical task with important consequences for both practicing clinicians and public health experts. Modern observational databases such as electronic health records provide an alternative to the longitudinal cohort studies traditionally used to construct risk models, bringing with them both opportunities and challenges. Large sample sizes and detailed covariate histories enable the use of sophisticated machine learning techniques to uncover complex associations and interactions, but observational databases are often 'messy', with high levels of missing data and incomplete patient follow-up.

Preparation and certification of two new bulk welding fume reference materials for use in laboratories undertaking analysis of occupational hygiene samples.

Workers can be exposed to fume, arising from welding activities, which contain toxic metals and metalloids. Occupational hygienists need to assess and ultimately minimize such exposure risks. The monitoring of the concentration of particles in workplace air is one assessment approach whereby fume, from representative welding activities, is sampled onto a filter and returned to a laboratory for analysis.

Evaluation of sampling methods for measuring exposure to volatile inorganic acids in workplace air. Part 1: sampling hydrochloric acid (HCl) and nitric acid (HNO₃) from a test gas atmosphere.

Historically, workplace exposure to the volatile inorganic acids hydrochloric acid (HCl) and nitric acid (HNO(3)) has been determined mostly by collection on silica gel sorbent tubes and analysis of the corresponding anions by ion chromatography (IC). However, HCl and HNO(3) can be present in workplace air in the form of mist as well as vapor, so it is important to sample the inhalable fraction of airborne particles. As sorbent tubes exhibit a low sampling efficiency for inhalable particles, a more suitable method was required.

Gene expression alterations in immune system pathways in the thymus after exposure to immunosuppressive chemicals.

Background: Dysregulation of positive and negative selection, antigen presentation, or apoptosis in the thymus can lead to immunosuppression or autoimmunity. Diethylstilbestrol (DES), dexamethasone (DEX), cyclophosphamide (CPS), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) are immunosuppressive chemicals that induce similar immunotoxic effects in the thymus, however, the mechanism of toxicity is purported to be different for each compound.

Objectives: We hypothesized that genomic analysis of thymus after chemical-induced atrophy would yield transcriptional profiles that suggest pathways of toxicity associated with reduced function.

The sheep erythrocyte T-dependent antibody response (TDAR).

The sheep erythrocyte T-dependent antibody Response (TDAR) evaluates the ability of animals sensitized in vivo to produce primary IgM antibodies to sheep erythrocytes (sRBC). The assay enumerates the number of antigen specific IgM antibody producing cells in the spleen. When exposure to the test material takes place in vivo, as does sensitization, the actual quantification of the number of antibody producing cells occurs ex vivo.

Interlaboratory study of the primary antibody response to sheep red blood cells in outbred rodents following exposure to cyclophosphamide or dexamethasone.

EPA guidelines provide a choice in evaluating humoral immune system function in rats and mice immunized with sheep red blood cells (sRBC): an antibody-forming cell (AFC) assay or a sRBC-specific serum IgM enzyme-linked immunosorbent assay (ELISA). Four different laboratories used both methods to detect suppression of the antibody response by cyclophosphamide (CP) or dexamethasone (DEX). Attempts were made to minimize interlaboratory variability through the use of common reagents and vendors; each laboratory used the same source for rodents, immunosuppressive agents, and one sheep for sRBCs, and determined optimal sRBC concentration for immunization and peak day of antibody response in female CD rats and CD1 mice.

Vinclozolin modulates splenic natural killer cell activity, antibody-forming cell response and phenotypic marker expression in sprague dawley rats: a two-generation feeding study.

The potential effects of the fungicide vinclozolin (VCZ) on the immune system were evaluated in F(0) (dams) and F(1) generations of Sprague Dawley rats exposed to a soy-free diet containing VCZ at 10, 150 and 750 ppm. In dams, exposure to VCZ at the highest concentration from gestation day 7 to postpartum day 51 (65 days total exposure) produced a significant increase in the numbers of splenocytes, B cells, T cells, helper T cells and cytotoxic T cells and a decrease in the percentage of NK cells. In F(1) males, exposure to VCZ gestationally, lactationally and through feed from postnatal day 22 to 64 (78 days total exposure) produced no effect on spleen or thymus weights or splenocyte subsets.

Modulation of immune response following dietary genistein exposure in F0 and F1 generations of C57BL/6 mice: evidence of thymic regulation.

To further determine whether genistein (GEN) modulation of the immune responses was related to its endocrine-disrupting properties and time of exposure, pregnant C57BL/6 mice were exposed to GEN at 0-1250 ppm in feed starting on day 14 of gestation. The C57BL/6 offspring were exposed to GEN in utero and lactationally, and through feed after weaning until postnatal day 42. In dams, exposure to GEN increased the terminal body weight (250 and 1250 ppm), the number of splenic T cells and NK cells (250 ppm), and the activity of NK cells (250 ppm).

Myelotoxicity in genistein-, nonylphenol-, methoxychlor-, vinclozolin- or ethinyl estradiol-exposed F1 generations of Sprague-Dawley rats following developmental and adult exposures.

The myelotoxicity of five endocrine active chemicals was evaluated in F1 generation of Sprague-Dawley rats following developmental and adult exposures at three concentration levels. Rats were exposed to genistein (GEN: 25, 250 and 1250 ppm), nonylphenol (NPH: 25, 500 and 2000 ppm), methoxychlor (MXC: 10, 100 and 1000 ppm), vinclozolin (VCZ: 10, 150 and 750 ppm) and ethinyl estradiol (EE2: 5, 25 and 200 ppb) gestationally and lactationally through dams from day 7 of gestation and through feed after weaning on postnatal day (PND) 22 to PND 64. The parameters examined included the number of recovered bone marrow cells, DNA synthesis, and colony forming units (CFU) in the presence of granulocyte macrophage-colony stimulating factor (GM-CSF), macrophage colony-stimulating factor (M-CSF) and erythropoietin.

Oral exposure to atrazine modulates cell-mediated immune function and decreases host resistance to the B16F10 tumor model in female B6C3F1 mice.

Atrazine (ATZ) is used throughout North America to control annual broadleaf weeds and grasses in various crops including; corn, sorghum, and sugar cane. Unfortunately, contamination of surface and ground water has occurred as a result of ATZ's chemical and physical properties, and its widespread use throughout the U.S.

Thalidomide modulation of the immune response in female B6C3F1 mice: a host resistance study.

Previously, we have reported that thalidomide (Thd) treatment can modulate the immune responses in female B6C3F1 mice. The present study was designed to evaluate whether or not these immunomodulatory responses were of sufficient magnitude to alter host resistances in a number of pathogen and tumor models. B6C3F1 mice were treated intraperitoneally with Thd (30-150 mg/kg) for 14 or 28 days, then inoculated with either Plasmodium yeolii, PYB6 fibrosarcoma tumor cells, B16F10 melanoma tumor cells, Listeria monocytogenes, or Streptococcus pneumoniae.

Evaluation of the immunomodulatory effects of the disinfection by-product, sodium chlorite, in female B6C3F1 mice: a drinking water study.

Sodium chlorite is an inorganic by-product of chlorine dioxide formed during the chlorination of drinking water. Relatively little is known about the adverse health effects of exposure to sodium chlorite in drinking water. In this study, we evaluated sodium chlorite's immunomodulatory properties using female B6C3F1 mice and a panel of immune assays that were designed to evaluate potential changes in innate and acquired cellular and humoral immune responses.

Immunotoxicity of sodium bromate in female B6C3F1 mice: a 28-day drinking water study.

Bromate is one of the water disinfection by-products (DBPs) produced during the process of ozonation. The purpose of this study was to evaluate the immunotoxic potential of sodium bromate (SB) in female B6C3F1 mice. SB was administered in the drinking water for 28 days at doses of 80-800 mg/l.

Evaluation of the immunomodulatory effects of the macrolide antibiotic, clarithromycin, in female B6C3F1 mice: a 28-day oral gavage study.

The macrolide antibiotic, clarithromycin, is used extensively to treat bacterial infections associated with pneumonia, duodenal ulcers, and the advanced stages of human immunodeficiency viral (HIV) infection. In addition to its antimicrobial properties, several studies have indicated that clarithromycin also has anti-inflammatory and immunomodulatory properties. In this study, clarithromycin's immunomodulatory properties were evaluated using female B6C3F1 mice and a panel of immune assays that were designed to evaluate potential changes in innate, and acquired cellular and humoral immune responses.

Carbon tetrachloride is immunosuppressive and decreases host resistance to Listeria monocytogenes and Streptococcus pneumoniae in female B6C3F1 mice.

Carbon tetrachloride (CCl(4)) is an environmental contaminant that has been detected in ambient air, seawater, surface-water and snow. The immunotoxic potential of CCl(4) was evaluated in female B6C3F1 mice. The animals were administered with CCl(4) daily for 14 days at doses of 50, 100, 500 or 1000 mg/kg body weight by gavage with corn oil as a vehicle.