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Sodium thiosulfate has been used for decades in the treatment of calciphylaxis and cyanide detoxification, and has recently shown initial therapeutic promise in critical diseases such as neuronal ischemia, diabetes mellitus, heart failure and acute lung injury. However, the precise mechanism of sodium thiosulfate remains incompletely defined and sometimes contradictory. Although sodium thiosulfate has been widely accepted as a donor of hydrogen sulfide (H2S), emerging findings suggest that it is the executive signaling molecule for H2S and that its effects may not be dependent on H2S. This article presents an overview of the current understanding of sodium thiosulfate, including its synthesis, biological characteristics, and clinical applications of sodium thiosulfate, as well as the underlying mechanisms in vivo. We also discussed the interplay of sodium thiosulfate and H2S. Our review highlights sodium thiosulfate as a key player in sulfide signaling with the broad clinical potential for the future.
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Sulfuro de Hidrógeno , Transducción de Señal , Tiosulfatos , Tiosulfatos/química , Sulfuro de Hidrógeno/metabolismo , Sulfuro de Hidrógeno/química , Humanos , Animales , Transducción de Señal/efectos de los fármacosRESUMEN
Solid-state NMR has been a vital tool for the study of structural evolution of cathodes in lithium-ion and sodium-ion batteries. However, the differentiation of relaxation parameters for certain sites is difficult owing to limited spectral resolution associated with strong anisotropic hyperfine interaction. Here we propose a novel IR-pjMATPASS method that can measure T1 relaxation with site-specific resolution for paramagnetic solids. We apply this method to the characterization of ball-milling induced order-disorder phase transition in Li6CoO4 as a case study. The quasi-quantitate 7Li NMR enables the synthetic optimization of high energy ball-milling conditions to harvest a disordered cubic phase through site-specific 7Li T1 measurements. The example study shown here provides a quantitative strategy for NMR studies of paramagnetic solids.
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The ability to monitor lithium deposition on the anodes in real time is becoming progressively more important due to the development of advanced anode technology. Given the fact that the detrimental Li deposits are always on the micron scale, electron paramagnetic resonance (EPR) happens to be a very effective and selective detection technology due to the skin effect. Here, quantitative in situ 1D EPR imaging is carried out with a magnetic field gradient to achieve a one-dimensional spatial resolution along the Li growth direction in a capillary cell. The quantification of Li deposits is carefully calibrated using a 1,1-diphenyl-2-picrylhydrazyl standard, and a processing method is presented to correct the double integration of the Dysonian line from the metallic Li. The Li deposition processes are compared in two different electrolytes. For the electrolyte containing fluoroethylene carbonate (FEC) additive, the fitting results of Dysonian lines suggest that the plated Li has a larger dimension of the microstructure and the stripping proceeds more uniformly. It thus accounts for the higher Coulombic efficiency in the electrolyte with FEC. In situ EPR imaging also suggests that the Sand's capacity varies with the electrolytes. The forced growth of dendritic Li is carried out at a very large current density using a derivative operando EPR method to monitor the growth locus of the Li dendrites, indicating a tip-growing mechanism. This work can be instructive for those who are engaged in the study of electro-deposited lithium using in situ EPR imaging technology.
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Carbonatos , Litio , Litio/química , Espectroscopía de Resonancia por Spin del Electrón , ElectrodosRESUMEN
Hydrophobic biomolecules realize their functions in vivo in aqueous environments, often through a delicate balance of amphiphilicity and chaperones. Introducing exogenous hydrophobic biomolecules into in vivo aqueous systems is a challenge in drug delivery and regenerative medicine, where labile linkers, carriers, and fusions or chimeric molecules are often designed to facilitate such aqueous interfaces. Here, we utilize naturally derived silk nanofiber shuttles with the capacity to transport hydrophobic cargos directly into aqueous solutions. These nanofibers disperse in organic solvents and in aqueous solutions because of their inherent amphiphilicity, with enriched hydrophobicity and strategically interspersed negatively charged groups. Hydrophobic molecules loaded on these shuttles in organic solvent-water systems separated from the solvent after centrifugation. These concentrated hydrophobic molecule-loaded nanofibers could then be dispersed into aqueous solution directly without modification. These shuttle systems were effective for different hydrophobic molecules such as drugs, vitamins, and dyes. Improved biological stability and functions of hydrophobic cargos after loading on these nanofibers suggest potential applications in drug delivery, cosmetology, medical diagnosis, and related health fields, with a relatively facile process.
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Interacciones Hidrofóbicas e Hidrofílicas , Nanofibras , Seda/química , Seda/metabolismo , Agua/metabolismo , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Humanos , Interacciones Hidrofóbicas e Hidrofílicas/efectos de los fármacos , Células MCF-7 , Nanofibras/administración & dosificación , Nanofibras/química , Seda/administración & dosificación , Soluciones/química , Soluciones/metabolismo , Agua/químicaRESUMEN
Functional vascularization is critical for the clinical regeneration of complex tissues such as kidney, liver or bone. The immobilization or delivery of growth factors has been explored to improve vascularization capacity of tissue engineered constructs, however, the use of growth factors has inherent problems such as the loss of signaling capability and the risk of complications such as immunological responses and cancer. Here, a new method of preparing water-insoluble silk protein scaffolds with vascularization capacity using an all aqueous process is reported. Acid was added temporally to tune the self-assembly of silk in lyophilization process, resulting in water insoluble scaffold formation directly. These biomaterials are mainly noncrystalline, offering improved cell proliferation than previously reported silk materials. These systems also have appropriate softer mechanical property that could provide physical cues to promote cell differentiation into endothelial cells, and enhance neovascularization and tissue ingrowth in vivo without the addition of growth factors. Therefore, silk-based degradable scaffolds represent an exciting biomaterial option, with vascularization capacity for soft tissue engineering and regenerative medicine.
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Chronic wound infections are associated with biofilm formation, which in turn has been correlated with drug resistance. However, the mechanism by which bacteria form biofilms in clinical environments is not clearly understood. This study was designed to investigate the biofilm formation potency of Acinetobacter baumannii and the potential association of biofilm formation with genes encoding efflux pumps, quorum-sensing regulators, and outer membrane proteins. A total of 48 clinically isolated A. baumannii strains, identified by enterobacterial repetitive intergenic consensus (ERIC)-PCR as types A-II, A-III, and A-IV, were analyzed. Three representative strains, which were designated A. baumannii ABR2, ABR11, and ABS17, were used to evaluate antimicrobial susceptibility, biofilm inducibility, and gene transcription (abaI, adeB, adeG, adeJ, carO, and ompA). A significant increase in the MICs of different classes of antibiotics was observed in the biofilm cells. The formation of a biofilm was significantly induced in all the representative strains exposed to levofloxacin. The levels of gene transcription varied between bacterial genotypes, antibiotics, and antibiotic concentrations. The upregulation of adeG correlated with biofilm induction. The consistent upregulation of adeG and abaI was detected in A-III-type A. baumannii in response to levofloxacin and meropenem (1/8 to 1/2× the MIC), conditions which resulted in the greatest extent of biofilm induction. This study demonstrates a potential role of the AdeFGH efflux pump in the synthesis and transport of autoinducer molecules during biofilm formation, suggesting a link between low-dose antimicrobial therapy and a high risk of biofilm infections caused by A. baumannii. This study provides useful information for the development of antibiofilm strategies.
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Acinetobacter baumannii/crecimiento & desarrollo , Acinetobacter baumannii/genética , Proteínas Bacterianas/genética , Biopelículas/crecimiento & desarrollo , Regulación Bacteriana de la Expresión Génica/genética , Proteínas de Transporte de Membrana/genética , Infecciones por Acinetobacter/tratamiento farmacológico , Acinetobacter baumannii/efectos de los fármacos , Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Farmacorresistencia Bacteriana Múltiple/genética , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Pruebas de Sensibilidad Microbiana/métodos , Percepción de Quorum/genética , Transcripción Genética/efectos de los fármacos , Transcripción Genética/genética , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/genéticaRESUMEN
Collagen (Coll), as the basic material of matrix scaffolds for cell growth, has been widely used in the field of tissue engineering and regenerative medicine. In this study, collagen protein was modified by L-lysine (Lys), and cross-linked by genipin (GN) to prepare the L-lysine-modified collagen (Lys-Coll-GN) scaffolds. Microstructure, pore size, porosity, stability and biocompatibility of Lys-Coll-GN scaffolds were observed. The results showed that the bond between L-lysine and collagen protein molecule was formed by generating amide linkage, and mouse embryo fibroblasts proliferation was not inhibited in the Lys-Coll-GN scaffolds. In the multiple comparisons of Coll-scaf- folds, Coll-GN scaffolds and Lys-Coll-GN scaffolds, Coll-scaffolds was the worst in mechanical characteristics while the highest in biodegradation rate. Compared to Coll-GN scaffolds, Lys-Coll-GN scaffolds had more fiber structure, higher interval porosity (P<0. 01). Although the tensile stress of Lys-Coll-GN scaffolds reduced significantly, its e- longation length extended when the scaffolds was fractured (P<0. 01). The percentage of Lys-Coll-GN scaffolds residual weight was lower than that of Coll-GN scaffolds after all the scaffolds were treated by collagenase for 5 days (P<0. 01). This study suggested that Lys-Coll-GN scaffold had good biocompatibility, and it improved the mechanical property and degradation velocity for collagen-based scaffold. This study gave a new predominant type of tissue engineering scaffold for the regenerative medicine.
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Materiales Biocompatibles/química , Colágeno/química , Iridoides/química , Lisina/química , Andamios del Tejido , Animales , Proliferación Celular , Reactivos de Enlaces Cruzados , Fibroblastos/citología , Ratones , Porosidad , Ingeniería de TejidosRESUMEN
In this letter, we advocate recognizing the genus Fusarium as the sole name for a group that includes virtually all Fusarium species of importance in plant pathology, mycotoxicology, medicine, and basic research. This phylogenetically guided circumscription will free scientists from any obligation to use other genus names, including teleomorphs, for species nested within this clade, and preserve the application of the name Fusarium in the way it has been used for almost a century. Due to recent changes in the International Code of Nomenclature for algae, fungi, and plants, this is an urgent matter that requires community attention. The alternative is to break the longstanding concept of Fusarium into nine or more genera, and remove important taxa such as those in the F. solani species complex from the genus, a move we believe is unnecessary. Here we present taxonomic and nomenclatural proposals that will preserve established research connections and facilitate communication within and between research communities, and at the same time support strong scientific principles and good taxonomic practice.
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Fusarium/clasificación , Plantas/microbiología , Fusarium/genética , Filogenia , Enfermedades de las Plantas/microbiologíaRESUMEN
The long-term cycling stability of LiCoO2 under high-voltage operation in lithium-ion batteries is still not satisfactory and the mechanism of capacity decay is not well understood. Here we mainly apply 17O MAS NMR spectroscopy to probe the phase transformation of cycled LiCoO2 cathodes in both liquid cells and solid cells. It turns out that deterioration into the spinel phase is the main cause.
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Suministros de Energía Eléctrica , Litio , ElectrodosRESUMEN
All-solid-state batteries with ultrathin lithium metal, close to the anode-free solid-state batteries, could achieve high energy density. However, it is not trivial to plate an ultrathin lithium metal layer on a Cu current collector (Cu-CC). In situ electron paramagnetic resonance (EPR) imaging showed that the pre-plating on Cu-CC in a Li-In|Li6PS5Cl|Cu cell without pressure holding produced a lithium metal layer with a small area. However, when a Li-In|Li6PS5Cl|Cu cell was held under a considerable pressure, this cell would produce a lithium metal layer with a large area. The Cu-CC with the ultrathin lithium metal layer of a small surface could be extracted and then assembled with LiNiO2 and Li6PS5Cl to achieve better electrochemical performance compared to that of a large surface, because a small area of the lithium metal layer would lead to fewer side reactions and less consumption of lithium ions. This work suggests the importance of the control of the lithium plating and the observation of lithium plating by in situ EPR imaging.
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The mechanism of action underlying the intriguing prominent bioactivity of urinary bladder matrix (UBM) for in situ tissue regeneration of soft tissue defects remains to be elucidated. It is speculated that the activity of UBM for cell adhesion, migration, and activation is inherent. The bioactivity of UBM for in situ tissue regeneration and its relation with the structure and intact soluble components of UBM were investigated in comparison to a collagen-based scaffold, PELNAC (PEL). We isolated the soluble component of the two materials with urea buffer, and evaluated the respective effect of these soluble components on the in vitro adhesion and migration of L929 fibroblasts. The spatiotemporal pattern of endogenous-cell ingrowth into the scaffolds and cell activation were investigated using a model of murine subcutaneous implantation. UBM is more capable of promoting the adhesion, migration, and proliferation of fibroblasts than PEL in a serum-independent manner. In vivo, as compared with PEL, UBM exhibits significantly enhanced activity for fast endogenous cell ingrowth and produces a more prominent pro-regenerative and pro-remodeling microenvironment by inducing the expression of TGF-ß1, VEGF, MMP-9, and murine type I collagen. Overall, our results suggest the prominent bioactivity of UBM for in situ tissue regeneration is inherent.
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Matriz Extracelular , Vejiga Urinaria , Ratones , Animales , Vejiga Urinaria/química , Matriz Extracelular/metabolismo , Andamios del Tejido/química , Colágeno Tipo I/metabolismo , Adherencias Tisulares/metabolismo , FibroblastosRESUMEN
Interfacial side reactions and space charge layers between the oxide cathode material and the sulfide solid-state electrolytes (SSEs), along with the structural degradation of the active material, significantly compromise the electrochemical performance of all-solid-state batteries (ASSLBs). Surface coating and bulk doping of the cathodes are considered the most effective approaches to mitigate the interface issues between the cathode and SSEs and enhance the structural integrity of composite cathodes. Here, a one-step low-cost means is ingeniously designed to modify LiCoO2 (LCO) with heterogeneous Li2 TiO3 /Li(TiMg)1/2 O2 surface coating and bulk gradient Mg doping. When applied in Li10 GeP2 S12 -based ASSLBs, the Li2 TiO3 and Li(TiMg)1/2 O2 coating layers effectively suppress interfacial side reactions and weaken space charge layer effect. Furthermore, gradient Mg doping stabilizes the bulk structure to mitigate the formation of spinel-like phases during local overcharging caused by solid-solid contact. The modified LCO cathodes exhibit excellent cycle performance with a capacity retention of 80 % after 870 cycles. This dual-functional strategy provides the possibility for large-scale commercial implementation of cathodes modification in sulfide based ASSLBs in the future.
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All-solid-state lithium batteries (ASSLBs) with high volumetric energy density and enhanced safety are considered one of the most promising next-generation batteries. Elucidating the capacity-fading mechanism caused by the space-charge layer (SCL) and the interfacial side reaction (ISR) is crucial for the future development of high-energy-density ASSLBs with a longer cycle life. Here, a systematic study to probe the electrochemical performance of Li10GeP2S12-based ASSLBs with stoichiometric-controlled LixCoO2 was performed with the aid of density functional theory (DFT) calculations, X-ray photoelectron spectroscopy (XPS), focused ion beam-field emission scanning electron microscopy (FIB-SEM), and solid-state nuclear magnetic resonance (NMR) spectroscopy. We discovered that the overstoichiometric Li1.042CoO2 shows a high capacity at first cycle with the smallest overpotential, but the capacity gradually decreases, which is ascribed to the weak SCL effect and strong interfacial side reactions. On the contrary, the lithium-deficient Li0.945CoO2 achieves the best cycling stability with a very low capacity associated with the strongest SCL effect and weak interfacial side reactions. The SCL effect is indeed coupled with ISR, which eventually leads to capacity fading in long-term operation. We believe that the new insights gained from this work will accelerate the future development of LiCoO2/LGPS-based ASSLBs with both a mitigated SCL effect and a longer cycle life.
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Introduction: Numerous studies have shown that mesenchymal stem cells (MSCs) promote cutaneous wound healing via paracrine signaling. Our previous study found that the secretome of MSCs was significantly amplified by treatment with IFN-γ and TNF-α (IT). It has been known that macrophages are involved in the initiation and termination of inflammation, secretion of growth factors, phagocytosis, cell proliferation and collagen deposition in wound, which is the key factor during wound healing. In the present study, we used a unique supernatant of MSCs from human umbilical cord-derived MSCs (UC-MSCs) pretreated with IT, designated S-IT MSCs, to explore whether S-IT MSCs have a better effect on improving wound healing by improving the biological function of macrophages than the control supernatant of MSCs (S-MSCs). Methods: In the present study, we used a unique supernatant of MSCs pretreated with IT subcutaneously injected into a mice total skin excision. We evaluated the effect of S-IT MSCs on wound healing and the quality of wound repair via promoting macrophages migration and M2 polarization in vivo. In addition, the effect of S-IT MSCs on macrophages migration, converting toward M2 phenotype and phagocytosis were also investigated in vitro. Results: Indeed, S-IT MSCs were found to be more potent in promoting macrophage migration, M2 polarization, phagocytosis, and promoting wound closure than S-MSCs during the wound repair. High levels of CCL2 and IL-6 were found in S-IT MSCs, which indicated that the optimization of macrophage function by S-IT MSCs may be achieved through their high expression of CCL2 and IL-6. Conclusions: Our results suggest that the beneficial paracrine effect of MSCs on wound healing can be amplified by pretreatment with IT, which may represent a new strategy for optimizing the therapeutic effect of MSCs on wound healing.
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Human dermal fibroblasts (HDFs) play important roles in all stages of wound healing. However, in nonhealing wounds, fibroblasts are prone to aging, resulting in insufficient migration, proliferation and secretion functions. Recent studies have suggested that mesenchymal stromal cells (MSCs) are conducive to wound healing and cell growth through paracrine cytokine signaling. In our studies, we found that conditioned medium of MSCs pretreated with IFN-γ and TNF-α (IT MSC-CM) has abundant growth factors associated with wound repair. Our in vitro results showed that the effects of IT MSC-CM on promoting cell migration, proliferation and activation in HDFs were better than those of conditioned medium from mesenchymal stromal cells (MSC-CM). Moreover, we embedded a scaffold material containing IT MSC-CM and reconfirmed that cell migration and activation were superior to that in the presence of MSC-CM in vivo. Generally, PDGF-BB is perceived as a promoter of the migration and proliferation of HDFs. Moreover, a high level of PDGF-BB in IT MSC-CM was detected, according to which we guess that the effect on HDFs may be mediated by the upregulation of PDGF-BB. These studies all showed the potential of IT MSC-CM to promote rapid and effective wound healing.
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Citocinas , Células Madre Mesenquimatosas , Becaplermina/metabolismo , Movimiento Celular , Proliferación Celular , Medios de Cultivo Condicionados/metabolismo , Medios de Cultivo Condicionados/farmacología , Citocinas/metabolismo , Fibroblastos/metabolismo , HumanosRESUMEN
BACKGROUND: Numerous studies have shown that mesenchymal stromal cells (MSCs) promote cutaneous wound healing via paracrine signaling. Our previous study found that the secretome of MSCs was significantly amplified by treatment with IFN-γ and TNF-α (IT). It has been known that macrophages are involved in the initiation and termination of inflammation, secretion of growth factors, phagocytosis, cell proliferation, and collagen deposition in wound, which is the key factor during wound healing. In this study, we aim to test whether the supernatant of MSCs pretreated with IT (S-IT MSCs) possesses a more pronounced effect on improving wound healing and describe the interplay between S-IT MSCs and macrophages as well as the potential mechanism in skin wound healing. METHODS: In the present study, we used a unique supernatant of MSCs from human umbilical cord-derived MSCs (UC-MSCs) pretreated with IT, designated S-IT MSCs, subcutaneously injected into a mice total skin excision. We evaluated the effect of S-IT MSCs on the speed and quality of wound repair via IT MSCs-derived IL-6-dependent M2 polarization in vivo by hematoxylin-eosin staining (H&E), immunohistochemistry (IHC), immunofluorescence (IF), Masson's trichrome staining, Sirius red staining, quantitative real-time PCR (qPCR). In addition, the effect of S-IT MSCs on the polarization of macrophages toward M2 phenotype and the potential mechanism of it were also investigated in vitro by flow cytometry (FCM), enzyme-linked immunosorbent assay (ELISA), tube formation assay, and western blot analysis. RESULTS: Compared with control supernatant (S-MSCs), our H&E and IF results showed that S-IT MSCs were more effectively in promoting macrophages convert to the M2 phenotype and enhancing phagocytosis of M2 macrophages. Meanwhile, the results of tube formation assay, IHC, Masson's trichrome staining, Sirius red staining showed that the abilities of M2 phenotype to promote vascularization and collagen deposition were significantly enhanced by S-IT MSCs-treated, thereby accelerating higher quality wound healing. Further, our ELISA, FCM, qPCR and western blot results showed that IL-6 was highly enriched in S-IT MSCs and acted as a key regulator to induce macrophages convert to the M2 phenotype through IL-6-dependent signaling pathways, ultimately achieving the above function of promoting wound repair. CONCLUSIONS: These findings provide the first evidence that the S-IT MSCs is more capable of eliciting M2 polarization of macrophages via IL-6-dependent signaling pathways and accelerating wound healing, which may represent a new strategy for optimizing the therapeutic effect of MSCs on wound healing.
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Citocinas , Células Madre Mesenquimatosas , Animales , Citocinas/metabolismo , Humanos , Interleucina-6/metabolismo , Células Madre Mesenquimatosas/metabolismo , Ratones , Comunicación Paracrina , Cicatrización de HeridasRESUMEN
  Abstract: In-vitro cultured autologous and allogenic keratinocytes were mixed in single-cell suspension and transplanted for the treatment of full-thickness, third-degree burns. Ten patients were selected according to a protocol approved by the authors' local Institutional Review Board. After epifascial necrectomy, the burns were temporarily covered with fresh allografts, and a mixed suspension of in-vitro cultured autologous and allogenic keratinocytes in fibrin glue with a density of 107 cells/mL was transplanted to the wounds by injection with a syringe in multipoint underneath the allograft. The grafting density was 5 × 106 cells per 100 cm2. The transplanted keratinocytes proliferated on the epifascial surface and grew into confluent epithelial layer 28 ± 7 days after transplantation. Complete re-epithelialization and stable skin conditions were achieved 62 ± 11 days after transplantation. This method decreased in-vitro cell culture time to 5 days and resulted in permanent re-epithelialization of third-degree burn wounds. To the authors' knowledge, this is the first report where autologous and allogenic keratinocytes were mixed and transplanted together to treat third-degree burn wounds. The performance and density of the keratinocytes remain to be studied .
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OBJECTIVE: We used tri5-PCR technique to identify the toxin-producing Fusarium strains, the toxogenic characteristics and toxicogenic condition of tri5 positive strains. We also evaluated the potential trichothecene-producing level of the Fusarium strains from the air and solid materials in poultry houses. METHODS: tri5 gene, the start gene encoding trichothecene synthase, was taken to detect 139 Fusarium isolates by PCR. Toxogenic culture was carried out for tri5 positive Fusarium strains, and the quantities of T-2 and HT-2 toxins in toxogenic cultures were measured by high performance liquid chromatography (HPLC) after immune-affinity column clear-up. RESULTS: Among the 42 tri5 positive strains determined by tri5-PCR, all 10 tri5 positive strains from the air in poultry houses were found to produce T-2 toxin (1.36-5 ng/mL) or HT-2 toxin (6.1-17.1 ng/mL) after culture. The optimal conditions for toxogenic culture were 9 days of culture with 5 degrees C-20 degrees C temperature fluctuation and light-dark alternating at 24 h intervals, shaking at early stage and non-shaking at later stage. The toxin production of tri5 positive strains was significantly affected by temperature and time, but it has no correlation with the dry mass of mycelium. CONCLUSION: In comparison with the traditional method, tri5-PCR is a rapid method for accurate detection of toxogenic Fusarium isolates in large amounts of environmental samples from poultry houses. The results provide a technical support and theoretical basis for early hazard warning and control of toxogenic Fusarium strains in animal raising environments.
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Microbiología Ambiental , Proteínas Fúngicas/genética , Fusarium/enzimología , Fusarium/aislamiento & purificación , Vivienda para Animales , Animales , Pollos , Proteínas Fúngicas/metabolismo , Fusarium/clasificación , Fusarium/genética , Tricotecenos/biosíntesisRESUMEN
Stem cells have potential utility in wound therapy, however the benefits are often limited due to cell injury from shear stress during injection and poor retention at the wound site. Here, shear-thinning silk nanofiber hydrogels were used to load bone marrow derived mesenchymal stem cells (BMSCs) and inject into wound sites to optimize cell retention and accelerate wound healing. The BMSCs in the silk nanofiber hydrogels maintained stemness better than the cells cultured on plates, and the expression of wound healing-related genes was significantly higher in the hydrogels with higher silk concentrations (2 wt%). The silk nanofibers physically prevented migration of BMSCs from the deposition site in the wound bed. In addition to faster wound healing, these BMSC-loaded hydrogels mediated angiogenesis and inflammation and improved collagen deposition and hair follicle regeneration in vivo in rats. Considering that these silk nanofiber hydrogels were successfully used here as carriers for stem cells to accelerate wound healing, further study for skin regeneration may be warranted.
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Hidrogeles/química , Nanofibras/química , Seda/química , Cicatrización de Heridas , Animales , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Movimiento Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Hidrogeles/farmacología , Masculino , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/metabolismo , Ratas , Ratas Sprague-Dawley , Andamios del Tejido/química , Cicatrización de Heridas/efectos de los fármacosRESUMEN
Dysangiogenesis and chronic inflammation are two critical reasons for diabetic foot ulcers. Desferrioxamine (DFO) was used clinically in the treatment of diabetic foot ulcers by repeated injections because of its capacity to induce vascularization. Biocompatible carriers that release DFO slowly and facilitate healing simultaneously are preferable options to accelerate the healing of diabetic wounds. Here, DFO-laden silk nanofiber hydrogels that provided a sustained release of DFO for more than 40 days were used to treat diabetic wounds. The DFO-laden hydrogels stimulated the healing of diabetic wounds. In vitro cell studies revealed that the DFO-laden hydrogels modulated the migration and gene expression of endothelial cells, and they also tuned the inflammation behavior of macrophages. These results were confirmed in an in vivo diabetic wound model. The DFO-laden hydrogels alleviated dysangiogenesis and chronic inflammation in the diabetic wounds, resulting in a more rapid wound healing and increased collagen deposition. Both in vitro and in vivo studies suggested potential clinical applications of these DFO-laden hydrogels in the treatment of diabetic ulcers.