Insects are the most abundant animals on Earth, and the microbiota within their guts play important roles by engaging in beneficial and pathological interactions with these hosts. In this study, we ...comprehensively characterized insect-associated gut bacteria of 305 individuals belonging to 218 species in 21 taxonomic orders, using 454 pyrosequencing of 16S rRNA genes. In total, 174,374 sequence reads were obtained, identifying 9,301 bacterial operational taxonomic units (OTUs) at the 3% distance level from all samples, with an average of 84.3 (± 97.7) OTUs per sample. The insect gut microbiota were dominated by Proteobacteria (62.1% of the total reads, including 14.1% Wolbachia sequences) and Firmicutes (20.7%). Significant differences were found in the relative abundances of anaerobes in insects and were classified according to the criteria of host environmental habitat, diet, developmental stage, and phylogeny. Gut bacterial diversity was significantly higher in omnivorous insects than in stenophagous (carnivorous and herbivorous) insects. This insect-order-spanning investigation of the gut microbiota provides insights into the relationships between insects and their gut bacterial communities.
Shoot regeneration can be achieved in vitro through a two‐step process involving the acquisition of pluripotency on callus‐induction media (CIM) and the formation of shoots on shoot‐induction media. ...Although the induction of root‐meristem genes in callus has been noted recently, the mechanisms underlying their induction and their roles in de novo shoot regeneration remain unanswered. Here, we show that the histone acetyltransferase HAG1/AtGCN5 is essential for de novo shoot regeneration. In developing callus, it catalyzes histone acetylation at several root‐meristem gene loci including WOX5, WOX14, SCR, PLT1, and PLT2, providing an epigenetic platform for their transcriptional activation. In turn, we demonstrate that the transcription factors encoded by these loci act as key potency factors conferring regeneration potential to callus and establishing competence for de novo shoot regeneration. Thus, our study uncovers key epigenetic and potency factors regulating plant‐cell pluripotency. These factors might be useful in reprogramming lineage‐specified plant cells to pluripotency.
Synopsis
Shoot regeneration from Arabidopsis callus can be achieved via a two‐step process that involves pluripotency acquisition. The histone acetyltransferase HAG1/AtGCN5 is essential for de novo shoot formation by regulating pluripotency‐inducing transcription factors.
HAG1 targets several root meristem gene loci specifically in developing callus.
In callus, HAG1 reprograms and activates expression of root genes by histone acetylation.
The HAG1‐regulated root genes encode key potency factors essential for de novo shoot regeneration.
Expression of HAG1 and its target genes enhance the regeneration ability of plant cells.
Histone acetyltransferase activity in the developing callus is essential for de novo shoot regeneration by regulating key pluripotency factors.
Abstract
A submerged dielectric barrier discharge plasma reactor (underwater DBD) has been used to inactivate biofilm produced by three different food-borne pathogens, namely
Escherichia coli
O157:H7 ...(ATCC 438),
Cronobacter sakazakii
(ATCC 29004), and
Staphylococcus aureus
(KCCM 40050). The inactivation that were obtained after 90 minutes of plasma operation were found to measure 5.50 log CFU/coupon, 6.88 log CFU/coupon and 4.20 log CFU/coupon for
Escherichia coli
O157:H7 (ATCC 438),
Cronobacter sakazakii
(ATCC 29004), and
Staphylococcus aureus
(KCCM 40050), respectively. Secondary Electron Images (SEI) obtained from Field Emission Scanning Electron Microscopy (FE-SEM) show the biofilm morphology and its removal trend by plasma operation at different time intervals. An attenuated total reflectance Fourier transform infrared (ATR-FTIR) measurement was performed to elucidate the biochemical changes that occur on the bacterial cell and extracellular polymeric substance (EPS) of biofilm during the plasma inactivation process. The ATR-FTIR measurement shows the gradual reduction of carbohydrates, proteins, and lipid and DNA peak regions with increased plasma exposure time. The presence of an EPS layer on the upper surface of the biofilm plays a negative and significant role in its removal from stainless steel (SS) coupons.
Because the digital workflow can begin directly in the oral cavity, intraoral scanners are being adopted in dental treatments. However, studies of the relationship between the experience of the ...practitioner and the accuracy of impression data are needed.
The purpose of this clinical study was to investigate the effect of the experience curve on changes in trueness when a patient’s complete dental arch is scanned.
Twenty dental hygienists with more than 3 years of experience in dental clinical practice (group 1 had 3 to 5 years; group 2 had >6 years) were recruited to learn to operate 2 intraoral scanner systems. All learners scanned the assigned patient’s oral cavity 10 times during the experience sessions. Precision was calculated as the mean deviation among all superimposition combinations from the 10 scanned data sets of each learner n=10C2=45. Trueness was evaluated by superimposing the 10 consecutive intraoral scan data onto the impression scan data from each patient’s rubber impression body (n=10). The acquired images were processed and analyzed using a 3-dimensional analysis software. For statistical analysis, the independent 2-sample t test and repeated measures ANOVA were performed (α=.05).
The mean precision of the Trios scanner was greater than that of the iTero (Trios, 52.30 μm; iTero, 60.46 μm; P<.01). The iTero group showed an improvement in trueness upon repeated experience (P<.05), whereas the Trios group did not (P>.05). In the iTero group but not in the Trios group, the length of clinical experience influenced the change of trueness as a result of repeated experience (P<.05). In terms of the scanned region, the results for trueness were better for the maxillary arch than the mandibular arch with repeated scanning in the iTero group (P<.05).
The single-image based system required repeated learning sessions for effective clinical application. The newer system offered better trueness and precision and was less likely to be influenced by the length of clinical career or the region being scanned.
Lipotoxic hepatocyte injury is a primary event in non-alcoholic steatohepatitis (NASH), but the mechanisms of lipotoxicity are not fully defined. Sphingolipids and free cholesterol (FC) mediate ...hepatocyte injury, but their link in NASH has not been explored. We examined the role of free cholesterol and sphingomyelin synthases (SMSs) that generate sphingomyelin (SM) and diacylglycerol (DAG) in hepatocyte pyroptosis, a specific form of programmed cell death associated with inflammasome activation, and NASH.
Wild-type C57BL/6J mice were fed a high fat and high cholesterol diet (HFHCD) to induce NASH. Hepatic SMS1 and SMS2 expressions were examined in various mouse models including HFHCD-fed mice and patients with NASH. Pyroptosis was estimated by the generation of the gasdermin-D N-terminal fragment. NASH susceptibility and pyroptosis were examined following knockdown of SMS1, protein kinase Cδ (PKCδ), or the NLR family CARD domain-containing protein 4 (NLRC4).
HFHCD increased the hepatic levels of SM and DAG while decreasing the level of phosphatidylcholine. Hepatic expression of
but not
was higher in mouse models and patients with NASH. FC in hepatocytes induced
expression, and
knockdown prevented HFHCD-induced NASH. DAG produced by SMS1 activated PKCδ and NLRC4 inflammasome to induce hepatocyte pyroptosis. Depletion of
prevented hepatocyte pyroptosis and the development of NASH. Conditioned media from pyroptotic hepatocytes activated the NOD-like receptor family pyrin domain containing 3 inflammasome (NLRP3) in Kupffer cells, but
knockout mice were not protected against HFHCD-induced hepatocyte pyroptosis.
SMS1 mediates hepatocyte pyroptosis through a novel DAG-PKCδ-NLRC4 axis and holds promise as a therapeutic target for NASH.
Abstract We developed an intra-articular (IA) drug delivery system to treat osteoarthritis (OA) that consisted of kartogenin conjugated chitosan (CHI-KGN). Kartogenin, which promotes the selective ...differentiation of mesenchymal stem cells (MSCs) into chondrocytes, was conjugated with low-molecular-weight chitosan (LMWCS) and medium-molecular-weight chitosan (MMWCS) by covalent coupling of kartogenin to each chitosan using an ethyl(dimethylaminopropyl) carbodiimide (EDC)/N-hydroxysuccinimide (NHS) catalyst. Nanoparticles (NPs, 150 ± 39 nm) or microparticles (MPs, 1.8 ± 0.54 μm) were fabricated from kartogenin conjugated-LMWCS and –MMWCS, respectively, by an ionic gelation using tripolyphosphate (TPP). The in vitro release profiles of kartogenin from the particles showed sustained release for 7 weeks. When the effects of the CHI-KGN NPs or CHI-KGN MPs were evaluated on the in vitro chondrogenic differentiation of human bone marrow MSCs (hBMMSCs), the CHI-KGN NPs and CHI-KGN MPs induced higher expression of chondrogenic markers from cultured hBMMSCs than unconjugated kartogenin. In particular, hBMMSCs treated with CHI-KGN NPs exhibited more distinct chondrogenic properties in the long-term pellet cultures than those treated with CHI-KGN MPs. The in vivo therapeutic effects of CHI-KGN NPs or CHI-KGN MPs were investigated using a surgically-induced OA model in rats. The CHI-KGN MPs showed longer retention time in the knee joint than the CHI-KGN NPs after IA injection in OA rats. The rats treated with CHI-KGN NPs or CHI-KGN MPs by IA injection showed much less degenerative changes than untreated control or rats treated with unconjugated kartogenin. In conclusion, CHI-KGN NPs or CHI-KGN MPs can be useful polymer-drug conjugates as an IA drug delivery system to treat OA.
The degradation of two organophosphates, chlorpyrifos and diazinon, in water using microplasma equipment to produce ozone and the identification of their products were studied by using liquid ...chromatography–mass spectrometry. The organophosphates gradually decreased with time and were completely removed after 10 min, and diazinon was degraded at a relatively fast rate compared to chlorpyrifos. The products formed during the process were identified and determined with accurate mass measurements and tandem mass spectrometry spectra, providing reliable structural determination. Chlorpyrifos oxon was formed through the oxidation of chlorpyrifos, followed by the formation of 3,5,6‐trichloro‐2‐pyridinol and diethyl phosphate by hydrolysis. Diazinon formed various products through more complicated degradation processes than those of chlorpyrifos. The major products of diazinon degradation were 2‐isopropyl‐6‐methyl‐4‐pyrimidinol and diethyl phosphate by hydrolysis after oxidation, exhibiting diazoxon as an intermediate at trace levels. Direct hydrolysis of diazinon also occurred, producing diethyl thiophosphate, which was observed at a low concentration for a transient time and exhibited a less favorable process than sequential oxidation and hydrolysis. The other products, hydroxy diazinons and hydroxy‐2‐isopropyl‐6‐methyl‐4‐pyrimidinols, formed by hydroxylation, were also identified, but they were present in low amounts. Degradation mechanisms of chlorpyrifos and diazinon were proposed with the quantitatively evaluated products.
Abstract
This is the first report, to our knowledge, of the preparation of an injectable in situ–forming click-crosslinked hyaluronic acid (Cx-HA) hydrogel (Cx-HA-CM) containing chemical immobilized ...cytomodulin-2 (CM), a chondrogenic differentiation factor, and on the utility of human periodontal ligament stem cells (hPLSCs) as a cell source for cartilage tissue engineering. hPLSCs served here as a stem cell source tolerant to ex vivo manipulation. CM induced in vitro chondrogenic differentiation of hPLSCs comparable to induction with traditional TGF-β. Cx-HA was prepared via a click-reaction between tetrazine-modified HA and transcyclooctene-modified HA. Cx-HA displayed significantly more features of a stiff hydrogel than HA. Cx-HA had a three-dimensional porous interconnected structure, absorbed a large volume of biological medium, and showed excellent biocompatibility. In contrast to HA, the Cx-HA hydrogel persisted in vitro and in vivo for an extended period, as evidenced by in vivo near-infrared fluorescence imaging. CM covalently linked to Cx-HA (Cx-HA-CM) remained inside Cx-HA for a prolonged period compared with CM physically loaded onto Cx-HA Cx-HA (+CM). Cx-HA-CM also caused better chondrogenic differentiation of hPLSCs, as evidenced by Alcian blue and Safranin O staining, and greater increases in the expression of type II collagen, glycosaminoglycan content and SOX9, aggrecan, and type 2α1 collagen mRNA levels. Thus, compared to Cx-HA (+CM), the hPLSC-loaded Cx-HA-CM hydrogel induced greater chondrogenic differentiation of hPLSCs via CM that was retained in the hydrogel for a much longer period of time.
Several intervention studies have suggested that vegetarian or vegan diets have clinical benefits, particularly in terms of glycemic control, in patients with type 2 diabetes (T2D); however, no ...randomized controlled trial has been conducted in Asians who more commonly depend on plant-based foods, as compared to Western populations. Here, we aimed to compare the effect of a vegan diet and conventional diabetic diet on glycemic control among Korean individuals.
Participants diagnosed with T2D were randomly assigned to follow either a vegan diet (excluding animal-based food including fish; n = 46) or a conventional diet recommended by the Korean Diabetes Association 2011 (n = 47) for 12 weeks. HbA1c levels were measured at weeks 0, 4, and 12, and the primary study endpoint was the change in HbA1c levels over 12 weeks.
The mean HbA1c levels at weeks 0, 4, and 12 were 7.7%, 7.2%, and 7.1% in the vegan group, and 7.4%, 7.2%, and 7.2% in the conventional group, respectively. Although both groups showed significant reductions in HbA1C levels, the reductions were larger in the vegan group than in the conventional group (-0.5% vs. -0.2%; p-for-interaction = 0.017). When only considering participants with high compliance, the difference in HbA1c level reduction between the groups was found to be larger (-0.9% vs. -0.3%). The beneficial effect of vegan diets was noted even after adjusting for changes in total energy intake or waist circumference over the 12 weeks.
Both diets led to reductions in HbA1c levels; however, glycemic control was better with the vegan diet than with the conventional diet. Thus, the dietary guidelines for patients with T2D should include a vegan diet for the better management and treatment. However, further studies are needed to evaluate the long-term effects of a vegan diet, and to identify potential explanations of the underlying mechanisms.
CRiS KCT0001771.
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