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Showing posts from February, 2023

Ivermectin Inhibits Growth of Chlamydia trachomatis in Epithelial Cells

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    by  Matthew A. Pettengill, Verissa W. Lam, Ikechukwu Ollawa, Camila Marques-da-Silva, David M. Ojcius.   Ivermectin is currently approved for treatment of both clinical and veterinary infections by nematodes, including  Onchocerca cervicalis  in horses and  Onchocerca volvulus  in humans. However, ivermectin has never been shown to be effective against bacterial pathogens. Here we show that ivermectin also inhibits infection of e pithelial cells by the bacterial pathogen,  Chlamydia trachomatis , at doses that could be envisioned clinically for sexually-transmitted or ocular infections by  Chlamydia .

Interactions between silica and titanium nanoparticles and oral and gastrointestinal epithelia: Consequences for inflammatory diseases and cancer

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by Cassio Luiz Coutinho Almeida-da-Silva, Leticia Ferreira Cabido, Wei-Chun Chin, Ge Wang, David M. Ojcius and Changqing Li.  Engineered nanoparticles (NPs) composed of elements such as silica and titanium, smaller than 100 nm in diameter and their aggregates, are found in consumer products such as cosmetics, food, antimicrobials and drug delivery systems, and oral health products such as toothpaste and dental materials. They may also interact accidently with epithelial tissues in the intestines and oral cavity, where they can aggregate into larger particles and induce inflammation through pathways such as inflammasome activation. Persistent inflammation can lead to precancerous lesions. Both the particles and lesions are difficult to detect in biopsies, especially in clinical settings that screen large numbers of patients. As diagnosis of early stages of disease can be lifesaving, there is growing interest in better understanding interactions between NPs and epithelium and develop...

An end to the H5N1 saga?

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Ojcius, David. "An end to the H5N1 saga?"  Nature Reviews Microbiology , vol. 10, no. 6, June 2012, p. 380.  In recent weeks the debate over the publication of two controversial H5N1 influenza virus articles has escalated, but a resolution finally seems to be on the cards. The research deals with the creation of mutant avian H5N1 variants that can spread among mammals by the aerosol route. Having initially ruled that the experimental details should be redacted from both papers, the US National Science Advisory Board for Biosecurity (NSABB) reversed this decision in March 2012 after reviewing revised versions of both papers, and the work of Kawaoka and colleagues was recently published in  Nature . The authors describe the generation of a reassortant virus in which the haemagglutinin (HA) protein of the 2009 human pandemic H1N1 influenza virus was replaced by an H5N1 HA carrying four mutations that facilitate transmission of the reassortant virus among ferrets through resp...

Stories by David M. Ojcius, Toni Darville and Patrik M. Bavoil

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News and research about Stories by  David  M.  Ojcius , Toni Darville and Patrik M. Bavoil, including commentary and archival articles published in Scientific American.

How do pandemics begin? There's a new theory — and a new strategy to thwart them

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  Most new pathogens, up to 75%, come from animals. They're often viruses that have been circulating in animals for decades, even centuries. At some point, they spill over into people.

Is a return to nature a piece of the health puzzle?

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In 1896, a German bookseller and self-educated man named Adolf Just founded the Jungborn sanatorium to promote a natural healing approach based on the effects of sunlight, food, water, air, plants, and the earth. In this outpost of civilization, people from all walks of life would make a “return to nature” to recover health, getting as much sunlight as possible, eating fresh and unprocessed food, walking barefooted on wet lawns, and sleeping on the bare ground in light-frame dwellings [ 1 ]. According to Just, humans had developed chronic diseases because they had been out of touch with nature for too long, living in cities and houses and using technologies that had not been designed for the human body. Words of reported health benefits spread fast and even Franz Kafka spent several weeks at Jungborn for a much needed break.   by Jan Martel and David M. Ojcius

Towards multiomic analysis of oral mucosal pathologies

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Oral mucosal pathologies comprise an array of diseases with worldwide prevalence and medical relevance. Affecting a confined space with crucial physiological and social functions, oral pathologies can be mutilating and drastically reduce quality of life. Despite their relevance, treatment for these diseases is often far from curative and remains vastly understudied. While multiple factors are involved in the pathogenesis of oral mucosal pathologies, the host’s immune system plays a major role in the development, maintenance, and resolution of these diseases. Consequently, a precise understanding of immunological mechanisms implicated in oral mucosal pathologies is critical (1) to identify accurate, mechanistic biomarkers of clinical outcomes; (2) to develop targeted immunotherapeutic strategies; and (3) to individualize prevention and treatment approaches. Here, we review key elements of the immune system’s role in oral mucosal pathologies that hold promise to overcome limitations in c...

Inactivation of mitochondrial pyruvate carrier promotes NLRP3 inflammasome activation and gout development via metabolic reprogramming

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The nucleotide-binding and oligomerization domain, leucine-rich repeats, and pyrin domain-containing protein 3 (NLRP3) inflammasome plays a crucial role in innate immunity and is involved in the pathogenesis of autoinflammatory diseases. Glycolysis regulates NLRP3 inflammasome activation in macrophages. However, how lactic acid fermentation and pyruvate oxidation controlled by the mitochondrial pyruvate carrier (MPC) affect NLRP3 inflammasome activation and autoinflammatory disease remains elusive. We found that the inactivation of MPC with genetic depletion or pharmacological inhibitors, MSDC-0160 or pioglitazone, increased NLRP3 inflammasome activation and IL-1β secretion in macrophages. Glycolytic reprogramming induced by MPC inhibition skewed mitochondrial ATP-associated oxygen consumption into cytosolic lactate production, which enhanced NLRP3 inflammasome activation in response to monosodium urate (MSU) crystals. As pioglitazone is an insulin sens MSDC-itizer used for diabetes, i...

Single-dose antibiotic prevents maternal sepsis and death

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Sepsis is 1 of the leading causes of maternal mortality. A single oral dose of the antibiotic azithromycin can reduce the risk of postpartum sepsis & death among women who deliver vaginally by 1/3, according to a large multi-country clinical trial.