RESUMO
Oxetane synthase (TmCYP1), a novel cytochrome P450 enzyme from Taxus×media cell cultures, has been functionally characterized to efficiently catalyse the formation of the oxetane ring in tetracyclic taxoids. Transient expression of TmCYP1 in Nicotiana benthamiana using 2α,5α,7ß,9α,10ß,13α-hexaacetoxytaxa-4(20),11(12)-diene (1) as a substrate led to the production of a major oxetane derivative, 1ß-dehydroxybaccatin IV (1 a), and a minor 4ß,20-epoxide derivative, baccatin I (1 b). However, feeding the substrate decinnamoyltaxinine J (2), a 5-deacetylated derivative of 1, yielded only 5α-deacetylbaccatin I (2 b), a 4ß,20-epoxide. A possible reaction mechanism was proposed on the basis of substrate-feeding, 2H and 18O isotope labelling experiments, and density functional theory calculations. This reaction could be an intramolecular oxidation-acetoxyl rearrangement and the construction of the oxetane ring may occur through a concerted process; however, the 4ß,20-epoxide might be a shunt product. In this process, the C5-O-acetyl group in substrate is crucial for the oxetane ring formation but not for the 4(20)-epoxy ring formation by TmCYP1. These findings provide a better understanding of the enzymatic formation of the oxetane ring in paclitaxel biosynthesis.
Assuntos
Sistema Enzimático do Citocromo P-450 , Éteres Cíclicos , Paclitaxel , Sistema Enzimático do Citocromo P-450/metabolismo , Paclitaxel/biossíntese , Paclitaxel/química , Paclitaxel/metabolismo , Éteres Cíclicos/química , Éteres Cíclicos/metabolismo , Taxus/enzimologia , Taxus/metabolismo , Biocatálise , Nicotiana/metabolismo , Nicotiana/enzimologia , Estrutura MolecularRESUMO
Rapid and sensitive monitoring of pH and histamine is crucial for bridging biological and food systems and identifying corresponding abnormal situations. Herein, N-doped carbon dots (CDs) are fabricated by a hydrothermal method employing dipicolinic acid and o-phenylenediamine as precursors. The CDs exhibit colorimetric and fluorescent dual-mode responses to track pH and histamine variations in living cells and food freshness, respectively. The aggregation-induced emission enhancement and intramolecular charge transfer result in a decrease in absorbance and an increase in fluorescence, which become readily apparent as the pH changes from acidic to neutral. This property enables precise differentiation between normal and cancerous cells. Furthermore, given the intrinsic basicity of histamine, pH-responsive CDs are advantageous for additional colorimetric and fluorescent monitoring of histamine in food freshness, achieving linearities of 25-1000 µM and 30-1000 µM, respectively, which are broader than those of alternative nanoprobes. Interestingly, the smartphone-integrated sensing platform can portably and visually evaluate pH and histamine changes due to sensitive color changes. Therefore, the sensor not only establishes a dynamic connection between pH and histamine for the purposes of biological and food monitoring, but also presents a novel approach for developing a multifunctional biosensor that can accomplish environmental monitoring and biosensing simultaneously.
Assuntos
Carbono , Colorimetria , Histamina , Pontos Quânticos , Histamina/análise , Carbono/química , Colorimetria/métodos , Concentração de Íons de Hidrogênio , Pontos Quânticos/química , Humanos , Técnicas Biossensoriais/métodos , Espectrometria de Fluorescência , Smartphone , Análise de Alimentos/métodos , Nitrogênio/química , Fluorescência , Corantes Fluorescentes/químicaRESUMO
PRCIS: We developed a modified iris cerclage technique that improves best corrected visual acuity, pupillary parameters, self-assessed photophobia, and visual function index-14 questionnaire scores in patients with acute primary angle closure and permanent mydriasis after cataract surgery. PURPOSE: To evaluate the efficacy of a modified iris cerclage technique in patients with acute primary angle closure (PAC) and permanent mydriasis after cataract surgery. PATIENTS AND METHODS: 12 eyes of 12 patients with acute PAC and permanent mydriasis at more than 3 months after phacoemulsification combined with intraocular lens (IOL) implantation underwent modified iris cerclage. Best corrected visual acuity (BCVA), intraocular pressure (IOP), pupil diameter, and visual function index-14 (VF-14) questionnaire and self-assessed photophobia scores before surgery and at 1 week, 1 month, and 3 months postoperatively were compared. Further, the postoperative pupil position and morphology and complications were evaluated. RESULTS: BCVA improved from 0.48±0.23 preoperatively to 0.28±0.15, 0.27±0.15, and 0.26±0.14 at 1 week, 1 month, and 3 months postoperatively, respectively (P=0.008). No significant difference was observed between the preoperative and postoperative IOP (P=0.974). Pupil diameter improved from 6.34±0.51 mm preoperatively to 3.59±0.33, 3.59±0.34, and 3.58±0.32 mm at 1 week, 1 month, and 3 months postoperatively, respectively (P<0.001). Self-assessed photophobia scores improved from 3.33±0.78 preoperatively to 0.83±0.72, 0.51±0.15, and 0.45±0.14 at 1 week, 1 month, and 3 months postoperatively, respectively (P<0.001). VF-14 scores improved from 47.6±6.1 points preoperatively to 67.9±6.2, 72.1±6.1, and 73.5±6.0 points at 1 week, 1 month, and 3 months postoperatively, respectively (P<0.001). Postoperatively, all pupils were centered and round. No postoperative complications, such as iris-suture slippage, iridodialysis, or exposure of the IOL's optical zone edge, were observed. CONCLUSION: Modified iris cerclage creates a centered, precisely sized, round pupil. It improves visual quality in patients with acute PAC and permanent mydriasis after cataract surgery.
RESUMO
PURPOSE: To evaluate the safety and efficacy of sutureless intrascleral intraocular lens (IOL) fixation combined with modified iris cerclage pupilloplasty for treating aphakia and traumatic mydriasis. METHODS: Five patients with aphakia and traumatic mydriasis were operated on by the same surgeon. All patients underwent sutureless intrascleral IOL fixation combined with modified iris cerclage pupilloplasty and were followed up for ≥6 months. Best-corrected visual acuity (BCVA) was measured using the logarithm of the minimum angle of resolution (logMAR). BCVA, intraocular pressure (IOP), pupil diameter, and corneal endothelial cell count (CECC) preoperatively and postoperatively were statistically analyzed. The pupil shape, photophobia, IOL position, and surgical complications were evaluated. RESULTS: The mean BCVA was significantly improved 6 months postoperatively (0.26 ± 0.17 logMAR, P = 0.042) than preoperatively (0.50 ± 0.30 logMAR). No significant difference was observed between the preoperative and postoperative IOP (P = 0.138). The mean pupil diameter significantly reduced postoperatively than preoperatively (3.44 ± 0.35 mm vs. 7.28 ± 0.35 mm, P = 0.043). There was no significant decrease in CECC postoperatively (P = 0.225). The pupil shape was round-like, and photophobia disappeared in all patients. No intraoperative or postoperative complications occurred. CONCLUSION: Sutureless intrascleral IOL fixation combined with modified iris cerclage pupilloplasty is a safe and efficient procedure for treating aphakia traumatic mydriasis patients without sufficient capsular support.
Assuntos
Afacia , Traumatismos Oculares , Lentes Intraoculares , Midríase , Humanos , Midríase/diagnóstico , Midríase/etiologia , Midríase/cirurgia , Implante de Lente Intraocular/métodos , Fotofobia , Acuidade Visual , Iris/cirurgia , Afacia/cirurgia , Traumatismos Oculares/cirurgia , Estudos Retrospectivos , Esclera/cirurgiaRESUMO
INTRODUCTION: This study aimed to evaluate the combined administration of anti-vascular endothelial growth factor (anti-VEGF) drugs before and during pars plana vitrectomy (PPV) and to explore its efficacy and safety in the treatment of patients with severe proliferative diabetic retinopathy (PDR). METHODS: This retrospective case series included consecutive patients who underwent PPV. Patients were categorized into two groups: the preoperative group was injected with anti-VEGF drugs before PPV, and the combination group was injected with anti-VEGF drugs before and during PPV. Preoperative, intraoperative, and postoperative clinical data were collected for analysis. The main outcome measures were changes in best-corrected visual acuity (BCVA) and central retinal thickness (CRT) and occurrence of postoperative vitreous cavity haemorrhage (POVCH). RESULTS: In total, 63 eyes of 60 patients with severe PDR were analysed. The operative duration and occurrence of intraoperative haemorrhage, iatrogenic retinal breaks, and silicone oil tamponade were similar between the two groups. The benefits on BCVA, and CRT after 1 week postoperatively, were more obvious in the combination group (P < 0.01). Combination therapy had the potential to reduce the incidence of POVCH. No ocular or systemic adverse events occurred in either group. CONCLUSIONS: The combined use of anti-VEGF drugs before and during PPV in patients with severe PDR not only includes the advantages of preoperative injection, but also has more significant prognostic benefits and favourable safety profiles.
RESUMO
Microbial electrolysis cells (MECs) are considered as green technologies for H2 production with simultaneously wastewater treatment. Low H2 recovery and production rate are two key bottlenecks of MECs fed with real H2 fermentation effluent of biomass wastes. This work established a 1 L cylindrical single chamber MEC and enriched electroactive anodic biofilms from cow dung compost to overcome the bottlenecks. These MEC components (platinum-coated cylindrical titanium mesh cathode and cylindrical graphite felt anode) were arranged in a concentric configuration. A high H2 production rate of 6.26 ± 0.23 L L-1 day-1 with H2 yield of 5.75 ± 0.16 L H2 L-1 fermentation effluent was achieved at 0.8 V. The degradation of acetate and butyrate (main components of H2 fermentation effluent) could reach to 95.3 ± 2.1% and 78.4 ± 3.6%, respectively. The microbial community analysis for anode showed the abundance of Geobacter (22.6%), Syntrophomonas (8.7%), and Dysgonomonas (6.3%) which are responsible to complex substrate oxidation, electrical current generation, and H2 production. These results prove the feasibility of cylindrical single-chamber MEC for high H2 production rate and high acetate and butyrate removal from H2 fermentation effluent.
Assuntos
Fontes de Energia Bioelétrica , Hidrogênio , Fermentação , Biomassa , Hidrogênio/metabolismo , Eletrólise/métodos , Eletrodos , Acetatos/metabolismo , ButiratosRESUMO
Eight C6-C3-based bibenzyl derivatives (dengraphenols A-G, K), three mono-bibenzyls (dengraphenols I, L-M), one bis-bibenzyl (dengraphenol H), one oxyneolignane (dengraphenol J), one phenanthrene (dengraphenol N), and one picrotoxane-type sesquiterpene (dengrasusane A) were isolated from the stems of Dendrobium gratiosissimum. The resolution of dengraphenols A-J by chiral HPLC afforded ten pairs of enantiomers [(±)-dengraphenols A-J]. Their structures with absolute configurations were elucidated on the basis of comprehensive spectroscopic analyses, computational calculation methods and single-crystal X-ray diffraction, among which twenty-four [(±)-dengraphenols A-E, (+)-dengraphenol F, (±)-dengraphenols G-J, dengraphenols K-N, dengrasusane A] were undescribed. Ten compounds [(±)-dengraphenol B, (±)-dengraphenols D-E, (±)-dengraphenol H, (-)-dengraphenol I and dengraphenol N)] showed potent cytotoxicity against eight human cancer cell lines (A431, A2780, H460, HCT8, BGC823, SW1990, Daoy, and HGC27) with IC50 values of 3.77-9.75 µM. At a concentration of 10 µM, (-)-dengraphenol C, (±)-dengraphenol F, and (±)-dengraphenol K exhibited remarkable hepatoprotective activity against APAP-induced toxicity with a cell survival rate of 65.8%, 70.6% and 73.5%, respectively; dengraphenol N displayed significant anti-inflammatory effects; and dengraphenol K showed strong inhibitory activity against α-glucosidase with IC50 values of 5.71 µM. These results would provide potential compounds for drug discovery.
Assuntos
Bibenzilas , Dendrobium , Neoplasias Ovarianas , Bibenzilas/química , Bibenzilas/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular , Dendrobium/química , Feminino , Humanos , Estrutura Molecular , Caules de PlantaRESUMO
BACKGROUND: After severe trauma of lower limbs, bone, tendon or plate graft exposure is common. The traditional repair method is to use a variety of skin flap transplantation to cover the exposed part, but the wound often can not heal after operation, or the wound is cracked, ulcer, sinus, bone and steel plate are exposed again after wound healing. The reason for this result is that when the flap is covered, the space around the bone plate is not well closed, forming a dead cavity, blood and exudate accumulation, hematoma formation or infection, and finally the wound ruptures again. In addition, due to the swelling and contracture of the flap after operation, the suture tension between the flap and the receiving area becomes larger, the skin becomes thinner and broken, and then the wound is formed. In order to solve the above problems, we carried out the study of artificial true skin embedding combined with fascial sleeve flap transplantation in the treatment of chronic bone plate exposed wounds of lower limbs. METHODS: In this paper, 11 cases of chronic wounds with bone exposure and skin necrosis after steel plate implantation were selected. First stage is the wound bed preparation including primary wound expansion, removal of necrotic tissue and incision of sinus wall, removal of deep necrotic bone and fibrotic scarred skin on the outer wall of steel plate to normal tissue on the outer edge of the wound, removal of precipitated peptone and purulent fur in the hole, periphery and bone space of the steel plate, and removal of tendon tissue with basal necrosis and disintegration of the wound. After vacuum sealing drainage (VSD) 1-2 weeks, the peritraumatic basal granulation tissue grew well and there was no necrotic tissue in the wound. In the second stage, the exposed bone was covered with artificial dermis, the steel plate hole or the periphery and the basal space were filled, and the exposed steel plate was completely embedded, and then the fascia sleeve flap was transplanted to cover the wound. The sural neurovascular flap was performed in nine cases and the lateral superior malleolar artery perforator flap in two case. RESULTS: The flap survived well in all 11 cases. During the follow-up of 6 months to the removal of the plate, there was no case of rupture, exposure and sinus formation. CONCLUSIONS: Artificial dermal covering combined with fascial sleeve flap transplantation can effectively avoid wound dehiscence or sinus formation caused by foreign body retention, infection and flap contracture. It has good effect in repairing chronic wounds with bone plate exposure after severe trauma of lower limbs.
Assuntos
Retalho Perfurante , Procedimentos de Cirurgia Plástica , Lesões dos Tecidos Moles , Placas Ósseas , Humanos , Extremidade Inferior/cirurgia , Transplante de Pele/métodos , Lesões dos Tecidos Moles/cirurgia , Resultado do TratamentoRESUMO
INTRODUCTION: Peters' anomaly (PA) and Axenfeld-Rieger syndrome (ARS) are typical classifications of anterior segment dysgenesis (ASD) and ascribed to congenital eye diseases that encompass developmental defects in anterior segment structures. The aim of this study is to discuss the unusual association between PA and ARS and to determine the results of penetrating keratoplasty combined with extracapsular cataract extraction and anterior vitrectomy for this unusual ophthalmic phenotype. PATIENT CONCERNS: A 72-year-old female was referred to Changzhou No. 2 People's Hospital for a progressive decrease in visual acuity in both eyes in the past few decades. DIAGNOSES: The patient was diagnosed with PA with cone-shaped polar cataracts in the left eye based on a series of ophthalmic examinations. ARS with retinal detachment was diagnosed in the right eye 2 years prior. INTERVENTIONS: Penetrating keratoplasty combined with extracapsular cataract extraction and anterior vitrectomy were performed to manage PA with cataracts in the left eye. OUTCOMES: Her best corrected visual acuity did not improve significantly after the operation. Patients with ARS and PA should be treated cautiously because of fundus lesions. CONCLUSION: This study revealed that cases with PA accompanied by iridocorneal adhesions, or other ocular anomalies, need to be treated cautiously for a very low success rate. It is of reference value for the evaluation of treatment prognosis for this joint occurrence of ophthalmic phenotypes.
Assuntos
Catarata , Opacidade da Córnea , Anormalidades do Olho , Idoso , Segmento Anterior do Olho/anormalidades , Segmento Anterior do Olho/diagnóstico por imagem , Catarata/complicações , Opacidade da Córnea/complicações , Opacidade da Córnea/diagnóstico , Opacidade da Córnea/cirurgia , Anormalidades do Olho/complicações , Anormalidades do Olho/diagnóstico , Oftalmopatias Hereditárias , Feminino , HumanosRESUMO
Lytic bacteriophages are re-considered as a solution to resolve antibiotic-resistant rampage. Despite frequent foodborne outbreaks caused by the top six non-O157 Shiga-toxin-producing Escherichia coli (STEC), the current interventions are not sufficiently effective against each serogroup, particularly O45. Therefore, this study aimed to characterize a new short-tailed phage, vB_EcoP-Ro45lw (or Ro45lw), as an alternative antimicrobial agent for STEC O45 strains. Phage Ro45lw belongs to the Kayfunavirus genus within the Autographiviridae family and shares no close evolutionary relationship with any reference phages. Ro45lw contains a tail structure composed of a unique tail fiber and tail tubular proteins A and B, likely to produce enzymatic activity against the target bacterial cells besides structural function. Additionally, the phage genome does not contain virulent, antibiotic-resistant, or lysogenic genes. The phage has a latent period of 15 min with an estimated burst size of 55 PFU/CFU and is stable at a wide range of pH (pH4 to pH11) and temperatures (30 °C to 60 °C). Regardless of the MOIs (MOI = 0.1, 1, and 10) used, Ro45lw has a strong antimicrobial activity against both environmental (E. coli O45:H-) and clinical (E. coli O45:H2) strains at 25 °C. These findings indicate that phage Ro45lw has antimicrobial potential in mitigating pathogenic STEC O45 strains.
RESUMO
Diabetic retinopathy, a common complication of diabetes, is the leading cause of blindness globally. Müller cells are key players in diabetes-associated retinal inflammation and dysfunction. However, the pathological changes of Müller cells in response to high glucose (HG) and the underlying mechanism remain unclear. The aim of the present study was to investigate the key role of heat shock protein 47 (HSP47) in HG-induced unfolded protein and inflammatory responses. Primary mouse Müller cells were starved in serum-free DMEM overnight and then treated with HG (30 mM) for 0, 6, 12 or 24 h. It was observed that HG (30 mM) significantly induced the protein expression of HSP47, inositol-requiring transmembrane kinase and endonuclease-1α (IRE1α) and spliced X-box-binding protein 1 (XBP1s) in primary mouse Müller cells compared with the untreated group. In addition, the immunoprecipitation results revealed that HSP47 directly interacted with IRE1α, and this interaction was significantly enhanced by HG exposure for 12 or 24 h compared with the untreated group. Furthermore, small interfering RNA-mediated silencing of HSP47 significantly suppressed HG-induced activation of the IRE1α/XBP1s/hypoxia inducible factor-1 subunit α (HIF-1α) pathway and upregulation of the mRNA expression levels of the inflammatory cytokines vascular endothelial growth factor, platelet-derived growth factor subunit B, inducible nitric oxide synthase and angiopoietin-2 in Müller cells. Furthermore, overexpression of IRE1α or HIF-1α partially attenuated HSP47-siRNA-mediated inhibition of inflammatory cytokine expression in Müller cells. Collectively, these results indicated that HG may induce HSP47 expression and promote the inflammatory response through enhancing the interaction between HSP47 and IRE1α, and activating the IRE1α/XBP1s/HIF-1α pathway in retinal Müller cells.
RESUMO
Previously, a polysaccharide produced by Chaetomiumglobosum CGMCC 6882 was found to have antibacterial activity, but its toxic effects on body health and gut microbiota were concealed. Recent results showed that this polysaccharide was safe to Caco-2 cells and mice, while it reduced the body weight gain of mice from 10.5 ± 1.21 g to 8.4 ± 1.17 g after 28 days administration. Acetate, propionate, butyrate and total short-chain fatty acids concentrations increased from 23.85 ± 1.37 µmol/g, 10.23 ± 0.78 µmol/g, 7.15 ± 0.35 µmol/g and 41.23 ± 0.86 µmol/g to 42.77 ± 1.29 µmol/g, 20.03 ± 1.44 µmol/g, 12.06 ± 0.51 µmol/g and 74.86 ± 2.07 µmol/g, respectively. Furthermore, this polysaccharide enriched the abundance of gut microbiota and the Firmicutes/Bacteroidetes ratio was increased from 0.5172 to 0.7238. Overall, this study provides good guidance for the promising application of polysaccharides as preservatives in foods and in other fields in the future.
RESUMO
Purpose: We verified whether fetal RPE (fRPE) cells and mesenchymal stem cells (MSCs) cotransplantation can combine the features of these two cell types and alleviate retinal degeneration in a retinal degenerative disease mouse model. Methods: Tail vein injection of sodium iodate (NaIO3) was conducted to establish the retinal degenerative disease mouse model. MSCs and fRPE cells were transplanted either separately or combined in the subretinal space of retinal degenerative disease animals. ERG, optical coherence tomography, histologic, and immunofluorescence analyses were performed. Furthermore, the expression level of Crx, rhodopsin, Iba1, F4/80, Caspase 3, nerve growth factor, and brain-derived neurotrophic factor were assessed to investigate the mechanisms involved in cell transplantation effects. Results: Cotransplantation of fRPE and MSC cells promoted significant improvements in ERG results and in the survival rate of transplanted cells. In addition, MSC and fRPE cell cotransplantation resulted in an increase in the thickness of the total retina, as well as in the outer and inner nuclear layers. Combined transplantation also upregulated the expression level of Crx and rhodopsin and downregulated caspase 3 expression, highlighting its better photoreceptor rescue effect in relation to the single cell type transplantation. Finally, combined transplantation suppressed the expression of Iba1 and F4/80 factors while increasing the endogenous expression of nerve growth factor and brain-derived nerve growth factor neurotrophic factors. These data suggest that MSC and fRPE cell cotransplantation is able to suppress immunoreactions and promote neurotrophic factor excretion. Conclusions: Combined transplantation of MSCs and fRPE cells results in a better retinal rescue effect than single cell type transplantation in NaIO3-induced retinopathy.
Assuntos
Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/citologia , Degeneração Retiniana/terapia , Epitélio Pigmentado da Retina/embriologia , Animais , Células Cultivadas , Modelos Animais de Doenças , Eletrorretinografia , Humanos , Iodatos/toxicidade , Camundongos , Camundongos Endogâmicos C57BL , Degeneração Retiniana/induzido quimicamente , Degeneração Retiniana/diagnóstico , Resultado do TratamentoRESUMO
Currently, rapid, sensitive, and convenient visual detection methods for Staphylococcus aureus (S. aureus) are scarce. In this study, a novel detection method based on recombinase polymerase amplification (RPA) and polymer flocculation sedimentation (PFS) was developed. Twelve effective primer combinations derived from four forward primers F1, F2, F3, F4, and three reverse primers R1, R2, R3 targeting the nuc gene of S. aureus were designed and screened by a polymerase chain reaction and RPA methods. RPA reaction conditions, including temperature, time, and volume as well as PEG8000 and NaCl concentrations range, were optimized. Moreover, the specificity and sensitivity of the RPA-PFS assay were further analyzed. Finally, the potential use of the RPA-PFS assay was evaluated using artificially S. aureus contaminated food samples, including pork, beef, shrimp, fish, cheese, cabbage, leftover rice, egg, milk, and orange juice. Results showed that the SA5 (F2/R2) combination was the optimal primer candidate. The optimal temperature range, the shortest time and the minimal volume of RPA reaction were 40-42 °C, 10 min and 10 µL, respectively and the optimal PEG8000/NaCl concentrations were 0.2 g/mL and 2.5 M, respectively, for the adsorption between magnetic beads and RPA products. The RPA-PFS method could detect as little as 13 fg genomic DNA of S. aureus and was also specific for five target S. aureus as well as twenty-seven non-target foodborne bacteria. The limit of detection of RPA-PFS for S. aureus in artificially contaminated food samples was 38 CFU/mL (g). Besides, RPA-PFS has directly been judged by the naked eye and has totally taken less than 20 min. In short, the assay RPA-PFS developed in this study is a rapid, sensitive, and specific visual detection method for S. aureus.
Assuntos
Floculação , Microbiologia de Alimentos/métodos , Técnicas de Amplificação de Ácido Nucleico , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Animais , Leite/microbiologia , Reação em Cadeia da Polimerase , Polímeros/química , Alimentos Marinhos/microbiologia , Sensibilidade e Especificidade , Infecções Estafilocócicas/prevenção & controleRESUMO
Rapid analytical methods are urgently needed to evaluate Escherichia coli (E. coli) O157:H7 in food. In this work, a novel recombinase polymerase amplification (RPA)-based lateral flow dipstick (LFD) method was developed to detect E. coli. Briefly, suitable primers and probes were designed and screened. Then, RPA reaction parameters, including volume, time, and temperature, were optimized. The specificity and sensitivity of RPA-LFD were analyzed, and a contaminated milk sample was used to test the detection performance of the proposed method. The optimal RPA reaction conditions included a minimum volume of 10 µL, incubation time of 10 min, temperature range of 39-42 °C, the primer pair EOF4/EOR3, and the probe EOProb. RPA-LFD was highly sensitive, it could detect as little as 1 fg of the genomic DNA of E. coli O157:H7, and 19 nontarget DNA of foodborne bacteria did not yield amplification products. Finally, the limit of detection of RPA-LFD for E. coli O157:H7 in artificially contaminated raw milk was 4.4 CFU/mL. In summary, the RPA-LFD assay developed in this study is an effective tool for the rapid investigation of E. coli O157:H7 contamination in raw milk samples.
Assuntos
Sondas de DNA/genética , Escherichia coli O157/genética , Escherichia coli O157/isolamento & purificação , Nucleotídeos/genética , Reação em Cadeia da Polimerase/métodos , Recombinases/metabolismo , Animais , Bovinos , Primers do DNA/genética , Contaminação de Alimentos/análise , Leite/microbiologia , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
To improve the accuracy of midterm power load forecasting, a forecasting model is proposed by combing kernel principal component analysis (KPCA) with back propagation neural network. First, the dimension of the input space is reduced by KPCA, then input the data set to the neural network model, optimized by particle swarm optimization. The monthly average of daily peak loads is forecasted to modify the daily forecast values and output the daily peak load in the end. Using the data provided by European Network on Intelligent Technologies to test the model, the mean absolute percent error of load forecasting model is only 1.39%. The feasibility and validity of the model have been proven.
Assuntos
Redes Neurais de Computação , Análise de Componente Principal , Previsões , Máquina de Vetores de SuporteRESUMO
Glaucoma is characterized by the death of retinal ganglion cells (RGCs) and visual field defects, and is a leading cause of blindness worldwide. Caffeic acid phenethyl ester (CAPE), a natural polyphenolic found in propolis from honeybee hives, can inhibit the activation of nuclear factor κ lightchainenhancer of activated B cells (NFκB) and has therapeutic potential in inflammatory disease. The present study used a rat model of optic nerve crush (ONC) injury to investigate the effect of CAPE on glaucoma. The death of RGCs at day 14 was significantly reduced in CAPEtreated animals compared with the nontreated group according to Brn3a and TUNEL staining. In addition, CAPE decreased the severity of inflammation in the retina, reflected by the decreased expression of inflammatory cytokines, including interleukin (IL)8, IL6, inducible nitric oxide synthase, cycloooxygenase2, tumor necrosis factorα and chemokine CC ligand2, in CAPEtreated rats. The hypertrophy of astrocytes and Müller cells (gliosis) caused by ONC was also found to be attenuated by CAPE, accompanied by the inhibition of NFκB signaling. Similarly, in vitro, CAPE suppressed the proliferation and migration of primary astrocytes induced by lipopolysaccharide, as well as the activation of NFκB. These results suggest that CAPE protected against RGC and attenuated inflammatory responses in a rat model of ONC by suppressing NFκB activation.
Assuntos
Ácidos Cafeicos/farmacologia , Ácidos Cafeicos/uso terapêutico , Células Ependimogliais/metabolismo , NF-kappa B/metabolismo , Álcool Feniletílico/análogos & derivados , Células Ganglionares da Retina/metabolismo , Animais , Astrócitos/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Quimiocina CCL2/metabolismo , Ciclo-Oxigenase 2/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Células Ependimogliais/efeitos dos fármacos , Células Ependimogliais/patologia , Glaucoma/tratamento farmacológico , Glaucoma/patologia , Gliose/tratamento farmacológico , Marcação In Situ das Extremidades Cortadas/métodos , Inflamação/tratamento farmacológico , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Lipopolissacarídeos/efeitos adversos , Masculino , NF-kappa B/efeitos dos fármacos , Óxido Nítrico Sintase Tipo II/metabolismo , Traumatismos do Nervo Óptico/metabolismo , Álcool Feniletílico/farmacologia , Álcool Feniletílico/uso terapêutico , Ratos , Ratos Sprague-Dawley , Retina/efeitos dos fármacos , Retina/patologia , Células Ganglionares da Retina/efeitos dos fármacos , Células Ganglionares da Retina/patologia , Transdução de Sinais/efeitos dos fármacos , Fator de Transcrição Brn-3A/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Composting is a complex biodegradable process that converts organic materials into nutrients to facilitate crop yields, and, if well managed, can render bactericidal effects. Majority of research focused on detection of enteric pathogens, such as Shiga toxin-producing Escherichia coli (STEC) in fecal composts. Recently, attention has been emphasized on bacteriophages, such as STEC-specific bacteriophages, associated with STEC from the fecal-contaminated environment because they are able to sustain adverse environmental condition during composting process. However, little is known regarding the isolation of STEC-specific bacteriophages in non-fecal composts. Thus, the objectives were to isolate and genomically characterize STEC-specific bacteriophages, and to evaluate its association with STEC in non-fecal composts. For bacteriophage isolation, the samples were enriched with non-pathogenic E. coli (3 strains) and STEC (14 strains), respectively. After purification, host range, plaque size, and phage morphology were examined. Furthermore, bacteriophage genomes were subjected to whole-genome sequencing using Illumina MiSeq and genomic analyses. Isolation of top six non-O157 and O157 STEC utilizing culture methods combined with PCR-based confirmation was also conducted. The results showed that various STEC-specific bacteriophages, including vB_EcoM-Ro111lw, vB_EcoM-Ro121lw, vB_EcoS-Ro145lw, and vB_EcoM-Ro157lw, with different but complementary host ranges were isolated. Genomic analysis showed the genome sizes varied from 42kb to 149kb, and most bacteriophages were unclassified at the genus level, except vB_EcoM-Ro111lw as FelixO1-like viruses. Prokka predicted less than 25% of the ORFs coded for known functions, including those essential for DNA replication, bacteriophage structure, and host cell lysis. Moreover, none of the bacteriophages harbored lysogenic genes or virulence genes, such as stx or eae. Additionally, the presence of these lytic bacteriophages was likely attributed to zero isolation of STEC and could also contribute to additional antimicrobial effects in composts, if the composting process was insufficient. Current findings indicate that various STEC-specific bacteriophages were found in the non-fecal composts. In addition, the genomic characterization provides in-depth information to complement the deficiency of biological features regarding lytic cycle of the new bacteriophages. Most importantly, these bacteriophages have great potential to control various serogroups of STEC.
RESUMO
Salmonella Typhimurium (S. Typhimurium) can cause serious foodborne diseases. In this study, an assay combining recombinase polymerase amplification (RPA) with lateral flow dipsticks (LFD) was developed to detect S. Typhimurium in milk. The RPA forward primers STF1, STF2, STF3, the reverse primer STR labeled with digoxin, and the probe STProb labeled with FAM were designed and screened to produce RPA products for LFD detection. The RPA reaction volume, temperature, and time were then optimized, and the sensitivity and specificity of the developed method were analyzed. Finally, the RPA-LFD method was evaluated using milk artificially contaminated with S. Typhimurium. Results indicated that the primer pair STF1/STR is the optimal combination for detecting the bacterium. The minimum volume, shortest time, and optimal temperature of the RPA reaction were 10⯵L, 10â¯min, and 40-42⯰C, respectively. The limit of detection of RPA-LFD for detecting the genomic DNA of S. Typhimurium was 1â¯fg, which is 5 and 10 times lower than the corresponding limits of RPA-agarose gel electrophoresis (AGE) and PCR-AGE, respectively. Testing with 29 other foodborne bacteria as controls revealed that RPA-LFD was highly specific for S. Typhimurium. RPA-LFD can detect S. Typhimurium at concentrations as low as 1.95â¯CFU/mL in artificially inoculated milk samples and is thus 10 times more sensitive than PCR. Hence, the RPA-LFD assay established in this study could be a potential point-of-care/need test for S. Typhimurium, especially in areas with limited resources.
Assuntos
Contaminação de Alimentos/análise , Leite/microbiologia , Técnicas de Amplificação de Ácido Nucleico , Salmonella typhimurium/enzimologia , Animais , Cromatografia de Afinidade , Microbiologia de Alimentos , Fitas Reagentes/química , Recombinases/química , Salmonella typhimurium/isolamento & purificação , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: With the progress of surgical techniques and instruments, various minimally invasive surgical therapies were developed to treat benign prostatic hyperplasisa (BPH). However, the efficacy and safety of different transurethral procedures for the treatment of BPH are still undefined. METHOD: A systematic search was performed for all randomized controlled trials (RCTs), which compared the transurethral procedures for BPH from 1995 to 2016. The clinical baseline characteristics, International Prostate Symptom Score (IPSS), quality of life (QoL), postvoid residual (PVR), maximum flow rate (Qmax), short-term and long-term complications were analyzed using RevMan and ADDIS software. RESULT: Eighty-eight randomly controlled trials and fifteen procedures were included in the network meta-analysis. HoLEP greatly inproved PVR. TmLRP had the best efficacy in improving QoL score. Diode laser vaporization of prostate was superior in improving IPSS and Qmax. Diode laser through vaporization required the shortest time in catheterization, while Nd:YAG was the longest procedure. For the hospitalization time, TUR was the longest and HoLEP was the shortest. TmLRP was related to the lowest postoperative hemoglobin decrease. TmLEP had the least rates of occurrence of hematuria, reoperation and erectile dysfunction. HoLEP was the best choice to reduce the incidence of recatheterization, urinary retention, urinary tract infection, stress urinary incontinence and retrograde ejaculation. The complications such as blood transfusion, urethral stricture, bladder neck contracture were relatively rare in the patients who underwent diode laser vaporization of prostate. CONCLUSION: Compared with other transurethral procedures, thulium, holmium and diode lasers were associated with better efficacy and fewer complications.