Mouse embryonic stem cells derived from the epiblast contribute to the somatic lineages and the germline but are excluded from the extra-embryonic tissues that are derived from the trophectoderm and ...the primitive endoderm upon reintroduction to the blastocyst. Here we report that cultures of expanded potential stem cells can be established from individual eight-cell blastomeres, and by direct conversion of mouse embryonic stem cells and induced pluripotent stem cells. Remarkably, a single expanded potential stem cell can contribute both to the embryo proper and to the trophectoderm lineages in a chimaera assay. Bona fide trophoblast stem cell lines and extra-embryonic endoderm stem cells can be directly derived from expanded potential stem cells in vitro. Molecular analyses of the epigenome and single-cell transcriptome reveal enrichment for blastomere-specific signature and a dynamic DNA methylome in expanded potential stem cells. The generation of mouse expanded potential stem cells highlights the feasibility of establishing expanded potential stem cells for other mammalian species.
is a facultative intracellular pathogen that can replicate and disseminate in mammalian macrophages. In this study, we analyzed fungal proteins identified in murine macrophage-like cells after ...infection with
. To accomplish this, we developed a protocol to identify proteins released from cryptococcal cells inside macrophage-like cells; we identified 127 proteins of fungal origin in infected macrophage-like cells. Among the proteins identified was urease, a known virulence factor, and others such as transaldolase and phospholipase D, which have catalytic activities that could contribute to virulence. This method provides a straightforward methodology to study host-pathogen interactions. We chose to study further Yeast Oligomycin Resistance (Yor1), a relatively uncharacterized protein belonging to the large family of ATP binding cassette transporter (ABC transporters). These transporters belong to a large and ancient protein family found in all extant phyla. While ABC transporters have an enormous diversity of functions across varied species, in pathogenic fungi they are better studied as drug efflux pumps. Analysis of
strains revealed defects in nonlytic exocytosis, capsule size, and dimensions of extracellular vesicles, when compared to wild-type strains. We detected no difference in growth rates and cell body size. Our results indicate that
releases a large suite of proteins during macrophage infection, some of which can modulate fungal virulence and are likely to affect the fungal-macrophage interaction.
Background Unilateral neck exploration (UNE) is becoming the procedure of choice for treatment of primary hyperparathyroidism (PHPT). The aim of this study was to evaluate the role of99m Tc-sestamibi ...(MIBI) parathyroid scintigraphy as the sole technique in selecting patients for UNE. Method We selected 136 consecutive PHPT patients who had only 1 solitary uptake at a MIBI were for UNE. The technique was a single dual-phase using MIBI and a subtraction technique with99m Tc-pertechnetate. Imaging data were correlated with surgical results. Results In 3 cases, the sestamibi scan was falsely positive, 1 had a contralateral location relative to the uptake, and 2 had multiglandular hyperplasia. Overall, the positive predictive value (PPV) of MIBI for detecting a solitary parathyroid adenoma in patients with 1 solitary uptake was 97.8. Sixteen patients (12%) had evidence of multinodular goiter. Overall, the PPV of MIBI was 98.4% (2 false positive among 120 cases) in patients with no multinodular thyroid disease (MNG) and 93.7% (1 false negative among 16 cases) in patients with MNG. The mean duration of the surgical procedure was 34.17 minutes. Mean hospitalization was 0.6 days. Conversion to bilateral neck exploration was performed in 5 patients. After a period of follow-up of 40 months (range, 6–72 months), the cure rate was 98%. Conclusion Patients with PHPT and unequivocally positive preoperative99m Tc-sestamibi can safely be managed with UNE without additional localizing techniques.
Cryptococcus neoformans is a fungal pathogen that causes cryptococcosis primarily in immunocompromised patients, such as those with HIV/AIDS. One survival mechanism of C. neoformans during infection ...is melanin production, which catalyzed by laccase and protects fungal cells against immune attack. Hence, the comparative assessment of laccase activity is useful for characterizing cryptococcal strains. We serendipitously observed that culturing C. neoformans with food coloring resulted in degradation of some dyes with phenolic structures. Consequently, we investigated the color changes for the food dyes metabolized by C. neoformans laccase and by using this effect explored the development of a colorimetric assay to measure laccase activity. We developed several versions of a food dye-based colorimetric laccase assay that can be used to compare the relative laccase activities between different C. neoformans strains. We found that phenolic color degradation was glucose-dependent, which may reflect changes in the reduction properties of the media. Our food color-based colorimetric assay has several advantages, including lower cost, irreversibility, and not requiring constant monitoring , over the commonly used 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay for determining laccase activity. This method has potential applications to bioremediation of water pollutants in addition to its use in determining laccase virulence factor expression.IMPORTANCECryptococcus neoformans is present in the environment, and while infection is common, disease occurs mostly in immunocompromised individuals. C. neoformans infection in the lungs results in symptoms like pneumonia, and consequently, cryptococcal meningitis occurs if the fungal infection spreads to the brain. The laccase enzyme catalyzes the melanization reaction that serves as a virulence factor for C. neoformans. Developing a simple and less costly assay to determine the laccase activity in C. neoformans strains can be useful for a variety of procedures ranging from studying the relative virulence of cryptococci to environmental pollution studies.
The fungus Cryptococcus neoformans is a major human pathogen with a remarkable intracellular survival strategy that includes exiting macrophages through non-lytic exocytosis (Vomocytosis) and ...transferring between macrophages (Dragotcytosis) by a mechanism that involves sequential events of non-lytic exocytosis and phagocytosis. Vomocytosis and Dragotcytosis are fungal driven processes, but their triggers are not understood. We hypothesized that the dynamics of Dragotcytosis could inherit the stochasticity of phagolysosome acidification and that Dragotcytosis was triggered by fungal cell stress. Consistent with this view, fungal cells involved in Dragotcytosis reside in phagolysosomes characterized by low pH and/or high oxidative stress. Using fluorescent microscopy, qPCR, live cell video microscopy, and fungal growth assays we found that the that mitigating pH or oxidative stress reduced Dragotcytosis frequency, whereas ROS susceptible mutants of C. neoformans underwent Dragotcytosis more frequently. Dragotcytosis initiation was linked to phagolysosomal pH, oxidative stresses, and macrophage polarization state. Dragotcytosis manifested stochastic dynamics thus paralleling the dynamics of phagosomal acidification, which correlated with the inhospitality of phagolysosomes in differently polarized macrophages. Hence, randomness in phagosomal acidification randomly created a population of inhospitable phagosomes where fungal cell stress triggered stochastic C. neoformans non-lytic exocytosis dynamics to escape a non-permissive intracellular macrophage environment.
Antarctic soils generally have low temperatures and limited availability of liquid water and nutrients. However, animals can increase the nutrient availability of ice-free areas by transferring ...nutrients from marine to terrestrial ecosystems, mainly through their excreta. In this study, we employed shotgun metagenomics and population genome binning techniques to study the diversity of microbial communities in Antarctic soils impacted by marine pinnipeds and birds relative to soils with no evident animal presence. We obtained ~285,000 16S rRNA gene-carrying metagenomic reads representing ~60 phyla and 100 metagenome-assembled genomes (MAGs) representing eight phyla. Only nine of these 100 MAGs represented previously described species, revealing that these soils harbor extensive novel diversity. Proteobacteria, Actinobacteria, and Bacteroidetes were the most abundant phyla in all samples, with Rhodanobacter being one of the most abundant genera in the bird-impacted soils. Further, the relative abundance of genes related to denitrification was at least double in soils impacted by birds than soils without animal influence. These results advance our understanding of the microbial populations and their genes involved in nitrous oxide emissions in ice-free coastal Antarctic soils impacted by marine animals and reveal novel microbial diversity associated with these ecosystems.
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•Marine animals, birds and pinnipeds, enrich soil nutrients in ice-free coastal lands.•We assessed microbial diversity by shotgun metagenomics and population genome binning.•Animal-impacted soils from Antarctica have a novelty microbial diversity.•Rhodanobacter is one of the most abundant genera in soils impacted by marine animals.•Denitrification genes are highly abundant in bird-impacted soils from Antarctica.
Obesity is a common metabolic disorder that has become a widespread epidemic in several countries. Sex and gender disparities in the prevalence of cardiovascular disease (CVD) have been well ...documented with premenopausal women having a lower incidence of CVD than age‐matched men. However, women are more likely than men to suffer from obesity, which can predispose them to a greater risk of CVD. The mechanisms underlying high‐fat diet (HFD)‐ or obesity‐induced hypertension are not well defined, although immune system activation and inflammation have been implicated in several studies. Further, the sex of the subject can have a profound influence on the immune response to hypertensive stimuli. Therefore, the purpose of this review is to examine the effects of sex and gender on the role of the immune system in HFD‐induced hypertension and vascular dysfunction.
LINKED ARTICLES
This article is part of a themed section on The Importance of Sex Differences in Pharmacology Research. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.21/issuetoc
We report on the design of an ascorbate interference-free lactate biosensor that takes advantage of the redox properties of ceria (CeO
2
) nanoparticles that make this material suitable to be used in ...electrochemical biosensors operating in low oxygen conditions. First, ceria-free lactate biosensors were fabricated using a positively charged polymer, polyethylenimine (PEI), for the immobilization of lactate oxidase (LOx) and ascorbate oxidase (AOx) on Pt electrodes. When AOx was not immobilized on the electrode, the sensor was interfered by ascorbate. Immobilization of AOx on the electrode surface, however, resulted in a loss of interference by ascorbate due to the depletion of oxygen in the enzyme layer. To address this challenge, we exploited the oxygen storage capacity of ceria nanoparticles
.
Their introduction into the enzyme layer enabled the fabrication of lactate biosensors that are not interfered by ascorbate and yet can be operated under low oxygen conditions. The Pt/CeO
2
–3(PEI/LOx)-3(PEI/AOx) biosensors, if operated at a working voltage of 0.6 V (vs. Ag/AgCl) display a wide linear range (20 μM to 1 mM), a low detection limit (0.3 μM) and a sensitivity of 172.9 ± 11.7 μA∙mM
−1
∙cm
−2
. Evidently, the layer-by-layer configuration eliminates interferences by common species such as ascorbic acid, uric acid, and glucose. The practical applicability of the sensors was evaluated by detecting lactate in human serum.
Graphical abstract
Ascorbate interference-free amperometric lactate biosensors were constructed using layer by layer deposition of ceria nanoparticles, polyethylenimine, lactate oxidase, and ascorbate oxidase.
Guidelines recommend routine screening for colorectal cancer (CRC) in asymptomatic adults starting at age 50. The most extensively used noninvasive test for CRC screening is the fecal immunochemical ...test (FIT), which has an overall sensitivity for CRC of approximately 61.0%-91.0%, which drops to 27.0%-67.0% for advanced adenomas. These figures contain a high false-positive rate and a low positive predictive value. This work aimed to develop a new, noninvasive CRC screening tool based on fecal bacterial markers capable of decreasing FIT false-positive rates in a FIT-positive population. We defined a fecal bacterial signature (RAID-CRC Screen) in a proof-of-concept with 172 FIT-positive individuals and validated the obtained results on an external cohort of 327 FIT-positive subjects. All study participants had joined the national CRC screening program. In the clinical validation of RAID-CRC Screen, a sensitivity of 83.9% and a specificity of 16.3% were obtained for the detection of advanced neoplasm lesions (advanced adenomas and/or CRC). FIT 20 μg/g produced 184 false-positive results. Using RAID-CRC Screen, this value was reduced to 154, thus reducing the false-positive rate by 16.3%. The RAID-CRC Screen test could be implemented in CRC screening programs to allow a significant reduction in the number of colonoscopies performed unnecessarily for FIT-positive participants of CRC screening programs.
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