Publications by authors named "J Mark Powell"

3,769 Publications

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Bovine respiratory microbiota of feedlot cattle and its association with disease.

Vet Res 2022 Jan 12;53(1). Epub 2022 Jan 12.

Division of Agriculture, Department of Animal Science, University of Arkansas, Fayetteville, AR, 72701, USA.

Bovine respiratory disease (BRD), as one of the most common and costly diseases in the beef cattle industry, has significant adverse impacts on global food security and the economic stability of the industry. The bovine respiratory microbiome is strongly associated with health and disease and may provide insights for alternative therapy when treating BRD. The niche-specific microbiome communities that colonize the inter-surface of the upper and the lower respiratory tract consist of a dynamic and complex ecological system. The correlation between the disequilibrium in the respiratory ecosystem and BRD has become a hot research topic. Hence, we summarize the pathogenesis and clinical signs of BRD and the alteration of the respiratory microbiota. Current research techniques and the biogeography of the microbiome in the healthy respiratory tract are also reviewed. We discuss the process of resident microbiota and pathogen colonization as well as the host immune response. Although associations between the microbiota and BRD have been revealed to some extent, interpreting the development of BRD in relation to respiratory microbial dysbiosis will likely be the direction for upcoming studies, which will allow us to better understand the importance of the airway microbiome and its contributions to animal health and performance.
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http://dx.doi.org/10.1186/s13567-021-01020-xDOI Listing
January 2022

The sphingosine 1-phosphate receptor 2/4 antagonist JTE-013 elicits off-target effects on sphingolipid metabolism.

Sci Rep 2022 Jan 10;12(1):454. Epub 2022 Jan 10.

Molecular Therapeutics Laboratory, Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, Australia.

Sphingosine 1-phosphate (S1P) is a signaling lipid that has broad roles, working either intracellularly through various protein targets, or extracellularly via a family of five G-protein coupled receptors Agents that selectively and specifically target each of the S1P receptors have been sought as both biological tools and potential therapeutics. JTE-013, a small molecule antagonist of S1P receptors 2 and 4 (S1P and S1P) has been widely used in defining the roles of these receptors in various biological processes. Indeed, our previous studies showed that JTE-013 had anti-acute myeloid leukaemia (AML) activity, supporting a role for S1P in the biology and therapeutic targeting of AML. Here we examined this further and describe lipidomic analysis of AML cells that revealed JTE-013 caused alterations in sphingolipid metabolism, increasing cellular ceramides, dihydroceramides, sphingosine and dihydrosphingosine. Further examination of the mechanisms behind these observations showed that JTE-013, at concentrations frequently used in the literature to target S1P, inhibits several sphingolipid metabolic enzymes, including dihydroceramide desaturase 1 and both sphingosine kinases. Collectively, these findings demonstrate that JTE-013 can have broad off-target effects on sphingolipid metabolism and highlight that caution must be employed in interpreting the use of this reagent in defining the roles of S1P.
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http://dx.doi.org/10.1038/s41598-021-04009-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8748775PMC
January 2022

Finally, an FDA Approval for an Immunization Against COVID-19: Hope on the Horizon.

Ann Pharmacother 2022 Jan 10:10600280211058387. Epub 2022 Jan 10.

UF Health Physicians-Physician Practices, UF Health Family Medicine-Haile Plantation, Gainesville, FL, USA.

Objective: Coronavirus disease 2019 (COVID-19) is a respiratory infection known as severe respiratory acute syndrome coronavirus 2 (SARS-CoV-2). The purpose of this manuscript is to review information leading to the Food and Drug Administration (FDA) approval of the Pfizer-BioNTech COVID-19 Vaccine.

Data Sources: A literature search was conducted of PubMed and clinicaltrials.gov (August 2018-October 2021) to identify trials related to the FDA approval of Pfizer-BioNTech COVID-19 Vaccine.

Study Selection And Data Extraction: Trials included are those the FDA deemed significant and accurate enough to be included in the FDA approval process. Information not recognized by the Centers of Disease Control and Prevention (CDC) nor FDA is omitted to not add to further confusion and misinformation.

Data Synthesis: In persons 16 years or older without evidence of prior SARS-CoV-2 infection, a total of 77 COVID-19 cases (0.39%) in the vaccine group from 7 days onward after the second dose vs 833 (4.1%) in the placebo group (Vaccine efficacy 91.1%; 95% confidence interval [CI]: 88.8-93.1). According the CDC definition of severe infection, there were no severe infections in the vaccine group 7 days and onward after the second dose, compared to 31 (0.15%) in the placebo group (Vaccine efficacy 100%; 95% CI: 87.6-100.0). Relevance to Patient Care and Clinical Practice: Reduction of infection by SARS-COV-2 is a top priority in protecting the health of all people and the official approval of the Pfizer-BioNTech vaccination may improve this goal.

Conclusions: Data available show a high efficacy rate of preventing SARS -CoV-2 with relatively low rates of ADE after full vaccination with Pfizer-BioNTech COVID-19 vaccine.
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http://dx.doi.org/10.1177/10600280211058387DOI Listing
January 2022

Trends in Glycemic Control Among Youth and Young Adults With Diabetes: The SEARCH for Diabetes in Youth Study.

Diabetes Care 2022 Jan 7. Epub 2022 Jan 7.

Department of Pediatrics, University of Washington, Seattle, WA.

Objectives: To describe temporal trends and correlates of glycemic control in youth and young adults (YYA) with youth-onset diabetes.

Research Design And Methods: The study included 6,369 participants with type 1 or type 2 diabetes from the SEARCH for Diabetes in Youth study. Participant visit data were categorized into time periods of 2002-2007, 2008-2013, and 2014-2019, diabetes durations of 1-4, 5-9, and ≥10 years, and age groups of 1-9, 10-14, 15-19, 20-24, and ≥25 years. Participants contributed one randomly selected data point to each duration and age group per time period. Multivariable regression models were used to test differences in hemoglobin A1c (HbA1c) over time by diabetes type. Models were adjusted for site, age, sex, race/ethnicity, household income, health insurance status, insulin regimen, and diabetes duration, overall and stratified for each diabetes duration and age group.

Results: Adjusted mean HbA1c for the 2014-2019 cohort of YYA with type 1 diabetes was 8.8 ± 0.04%. YYA with type 1 diabetes in the 10-14-, 15-19-, and 20-24-year-old age groups from the 2014-2019 cohort had worse glycemic control than the 2002-2007 cohort. Race/ethnicity, household income, and treatment regimen predicted differences in glycemic control in participants with type 1 diabetes from the 2014-2019 cohort. Adjusted mean HbA1c was 8.6 ± 0.12% for 2014-2019 YYA with type 2 diabetes. Participants aged ≥25 years with type 2 diabetes had worse glycemic control relative to the 2008-2013 cohort. Only treatment regimen was associated with differences in glycemic control in participants with type 2 diabetes.

Conclusions: Despite advances in diabetes technologies, medications, and dissemination of more aggressive glycemic targets, many current YYA are less likely to achieve desired glycemic control relative to earlier cohorts.
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http://dx.doi.org/10.2337/dc21-0507DOI Listing
January 2022

Premature rejection in science: The case of the Younger Dryas Impact Hypothesis.

Sci Prog 2022 Jan-Mar;105(1):368504211064272

5116University of Southern California, Los Angeles, CA, USA.

The progress of science has sometimes been unjustifiably delayed by the premature rejection of a hypothesis for which substantial evidence existed and which later achieved consensus. Continental drift, meteorite impact cratering, and anthropogenic global warming are examples from the first half of the twentieth century. This article presents evidence that the Younger Dryas Impact Hypothesis (YDIH) is a twenty-first century case.The hypothesis proposes that the airburst or impact of a comet ∼12,850 years ago caused the ensuing ∼1200-year-long Younger Dryas (YD) cool period and contributed to the extinction of the Pleistocene megafauna in the Western Hemisphere and the disappearance of the Clovis Paleo-Indian culture. Soon after publication, a few scientists reported that they were unable to replicate the critical evidence and the scientific community at large came to reject the hypothesis. By today, however, many independent studies have reproduced that evidence at dozens of YD sites. This article examines why scientists so readily accepted the early false claims of irreproducibility and what lessons the premature rejection of the YDIH holds for science.
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http://dx.doi.org/10.1177/00368504211064272DOI Listing
January 2022
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