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1.
Nat Commun ; 11(1): 5838, 2020 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-33203860

RESUMO

Emergence of SARS-CoV-2 causing COVID-19 has resulted in hundreds of thousands of deaths. In search for key targets of effective therapeutics, robust animal models mimicking COVID-19 in humans are urgently needed. Here, we show that Syrian hamsters, in contrast to mice, are highly permissive to SARS-CoV-2 and develop bronchopneumonia and strong inflammatory responses in the lungs with neutrophil infiltration and edema, further confirmed as consolidations visualized by micro-CT alike in clinical practice. Moreover, we identify an exuberant innate immune response as key player in pathogenesis, in which STAT2 signaling plays a dual role, driving severe lung injury on the one hand, yet restricting systemic virus dissemination on the other. Our results reveal the importance of STAT2-dependent interferon responses in the pathogenesis and virus control during SARS-CoV-2 infection and may help rationalizing new strategies for the treatment of COVID-19 patients.

2.
Int J Biol Macromol ; 2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-33181208

RESUMO

Polycyclic aromatic hydrocarbons are environmental pollutants with strong carcinogenicity, indirect teratogenicity, and mutagenicity. This study explored the interaction mechanism of benzo(a)pyrene with free DNA in vitro by using various analytical methods. UV-vis spectra showed that benzo(a)pyrene and DNA formed a new benzo(a)pyrene-DNA complex. The thermal melting temperature of DNA increased by 12.7 °C, showing that the intercalation of benzo(a)pyrene into DNA could promote the stability of the DNA double helix structure. The intercalation of benzo(a)pyrene with DNA in vitro was further confirmed by fluorescence microscopy with magnetic beads. Fluorescence spectra showed that the interaction between DNA and benzo(a)pyrene decreased the fluorescence intensity of benzo(a)pyrene, and the maximum quenching rate was 27.89%. The quenching mode of benzo(a)pyrene was static quenching. Thermodynamic data showed that the main driving forces were van der Waals forces and hydrogen bonds, and the reaction was spontaneous. The results of this study provided a novel insight for the establishment of polycyclic aromatic hydrocarbon capture and elimination through polycyclic aromatic hydrocarbon-DNA intercalation.

3.
Front Immunol ; 11: 561948, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33042141

RESUMO

Sepsis is a life-threating multi-organ disease induced by host innate immunity to pathogen-derived endotoxins including lipopolysaccharide (LPS). Direct sensing of LPS by caspase-11 activates inflammasomes and causes lethal sepsis in mice. Inhibition of caspase-11 inflammasomes is important for the prevention of LPS-induced septic shock; however, whether a caspase-11 inflammasome-specific suppressive mechanism exists is unclear. Here we show that deficiency of GABARAP autophagy-related proteins results in over-activation of caspase-11 inflammasomes but not of canonical inflammasomes. Gate-16 -/- Gabarap -/- macrophages exhibited elevated guanylate binding protein 2 (GBP2)-dependent caspase-11 activation and inflammatory responses. Deficiency of GABARAPs resulted in formation of GBP2-containing aggregates that promote IL-1ß production. High mortality after low dose LPS challenge in Gate-16 -/- Gabarap -/- mice primed with poly(I:C) or polymicrobial sepsis was ameliorated by compound GBP2 deficiency. These results reveal a critical function of Gate-16 and Gabarap to suppress GBP2-dependent caspase-11-induced inflammation and septic shock.

4.
Crit Rev Food Sci Nutr ; : 1-17, 2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33034198

RESUMO

Frozen foods are among the most popular food products and the development of techniques for the rapid detection of their structures and quality is important for the frozen food industry. In the current review, the principles and applications of Raman spectroscopic techniques in detecting and evaluating the structure changes and quality of frozen foods are discussed and merits and drawbacks of each Raman type are presented. These techniques include dispersive, Fourier transform, spatially offset, micro Raman spectroscopies. Raman spectroscopy can assess the compositional, physicochemical, and sensory characteristics of the frozen foods without any pretreatment. It can also be applied to investigate the structural alterations of protein, lipid, water and other components. Further trends of developing the Raman spectroscopy in monitoring the frozen foods should focus on reducing overlapping signals, achieving real noninvasive detection, eliminating misclassification and quantification errors, establishing standardized Raman database, and controlling cost.

5.
J Am Chem Soc ; 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33078947

RESUMO

Structurally well-defined graphene nanoribbons (GNRs) have emerged as highly promising materials for the next-generation nanoelectronics. The electronic properties of GNRs critically depend on their edge topologies. Here, we demonstrate the efficient synthesis of a curved GNR (cGNR) with a combined cove, zigzag, and armchair edge structure, through bottom-up synthesis. The curvature of the cGNR is elucidated by the corresponding model compounds tetrabenzo[a,cd,j,lm]perylene (1) and diphenanthrene-fused tetrabenzo[a,cd,j,lm]perylene (2), the structures of which are unambiguously confirmed by the X-ray single-crystal analysis. The resultant multi-edged cGNR exhibits a well-resolved absorption at the near-infrared (NIR) region with a maximum peak at 850 nm, corresponding to a narrow optical energy gap of ∼1.22 eV. Employing THz spectroscopy, we disclose a long scattering time of ∼60 fs, corresponding to a record intrinsic charge carrier mobility of ∼600 cm2 V-1 s-1 for photogenerated charge carriers in cGNR.

6.
Artigo em Inglês | MEDLINE | ID: mdl-33112494

RESUMO

Here, we demonstrate a novel one-pot synthetic method towards a series of boron-doped polycyclic aromatic hydrocarbons (B-PAHs, 1a - 1o ), including hitherto unknown B-doped zethrene derivatives, from ortho -aryl substituted diarylalkynes with high atom efficiency and broad substrate scopes. A reaction mechanism is proposed based on the experimental investigation together with the theoretical calculations, which involves a unique 1,4-boron migration process. The resultant benchtop-stable B-PAHs are thoroughly investigated by X-ray crystallography, cyclic voltammetry, UV/Vis absorption, and fluorescence spectroscopies. The blue and green organic light-emitting diode (OLED) devices based on 1f and 1k are further fabricated, demonstrating the promising application potential of B-PAHs in organic optoelectronics.

7.
Medicine (Baltimore) ; 99(44): e22741, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-33126311

RESUMO

Percutaneous balloon dilatation for benign biliary-enteric anastomosis stricture has been the most widely used alternative to endoscopic treatment. However, patency results from the precedent literature are inconsistent.The objective of this study was to evaluate the safety and feasibility of repeated balloon dilatation with long-term biliary drainage for the treatment of benign biliary-enteric anastomosis strictures.Data from patients with benign biliary-enteric anastomosis strictures who underwent percutaneous transhepatic cholangiography (PTC), repeated balloon dilatation with long-term biliary drainage (repeated-dilatation group; n = 23), or PTC and single balloon dilatation with long-term biliary drainage (single-dilatation group; n = 26) were reviewed. Postoperative complications, jaundice remission, and sustained anastomosis patency were compared between the groups.All procedures were successful. No severe intraoperative complications, such as biliary bleeding and perforation, were observed. The jaundice remission rate in the first week was similar in the 2 groups. During the 26-month follow-up period, 3 patients in the repeated-dilatation group had recurrences (mean time to recurrence: 22.84 ±â€Š0.67 months, range: 18-26 months). In the single-dilatation group, 15 patients had recurrences (mean time to recurrence = 15.28 ±â€Š1.63 months, range: 3-18 months). The duration of patency after dilatation was significantly better in the repeated-dilatation group (P = .01). All patients with recurrence underwent repeat PTC followed by balloon dilatation and biliary drainage.Repeated balloon dilatation and biliary drainage is an effective, minimally invasive, and safe procedure for treating benign biliary-enteric anastomosis strictures, and provides significantly higher patency rates than single dilatation.


Assuntos
Cateterismo/métodos , Dilatação/métodos , Drenagem/métodos , Complicações Pós-Operatórias/cirurgia , Estomas Cirúrgicos/efeitos adversos , Adulto , Idoso , Anastomose Cirúrgica/efeitos adversos , Ductos Biliares/patologia , Ductos Biliares/cirurgia , Constrição Patológica/etiologia , Constrição Patológica/cirurgia , Estudos de Viabilidade , Feminino , Humanos , Intestino Delgado/patologia , Intestino Delgado/cirurgia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos , Estomas Cirúrgicos/patologia , Resultado do Tratamento
8.
Artigo em Inglês | MEDLINE | ID: mdl-33124510

RESUMO

In this study, DNA-functionalize-magnetic beads were investigated as sorbent materials for effective removing 1,2-benzanthracene (BaA) from water. In order to reveal the removal mechanism, the interaction mode between BaA and DNA was evaluated by using various characterization tools such as UV-visible and circular dichroism spectroscopy, fluorescence and resonance scattering spectroscopy, and agarose gel electrophoresis. In the presence of BaA, the melting temperature of DNA increased from 76.2 °C to 82.3 °C, which closely related to the intercalating of BaA. It was found that a part of the ethidium bromide (EB) binding sites to DNA were occupied by BaA in EB competing study. The results indicated that a new complex appeared between hsDNA and BaA, and the number of the binding sites (n) and the binding constants (KA) at different temperatures were obtained. DNA binding saturation value (≈0.80) was obtained by resonance scattering spectra study. BaA could be enriched and removed by DNA-functionalize-magnetic beads via the intercalation, and the removal efficiency was 97.73% when the initial concentration was 2.45 x10-6 mol·L-1 (559.31 µg/L).

9.
Zhongguo Gu Shang ; 33(10): 943-7, 2020 Oct 25.
Artigo em Chinês | MEDLINE | ID: mdl-33107258

RESUMO

OBJECTIVE: To explore clinical application of the new three-dimensional foramen guide in percutaneous endoscopic lumbar discectomy. METHODS: Based on the principle of reverse positioning, a new three-dimensional foramen guide was designed. From May 2016 to May 2018, totally 40 patients with segmental lumbar disc herniation were underwent percutaneous endoscopic lumbar discectomy. The patients were divided into guide and control group, and 20 patients in each group. In guide group, there were 9 males and 11 females with an average age of (46.0±11.0) years old;5 patients on L3,4, 15 patients on L4,5; BMI was (25.4±3.2) kg /m2;three dimensional foramen guide was used to assist the operation. While in control group, there were 10 males and 10 females with an average age of (51.8±9.8) years old;4 patients on L3,4, 16 patients on L4,5;BMI was (24.8±3.5) kg /m2;the operation was completed with bare hands according to the experience. The puncture time, times of fluoroscopy and puncture between two groups were compared, as well as the preoperative and postoperative visual analogue scale (VAS) score and Japanese Orthopaedic Association (JOA) were compared. RESULTS: All patients had no serious complications, and successfully completed operation. Operation time, the times of fluoroscopy and puncture in guide group were better than those of control group (P<0.05). VAS score and JOA score between two groups were significantly relieved after operation (P<0.05), but there was no significant difference between two groups (P>0.05). CONCLUSION: The three dimensional foramen guide is compact in structure, simple in operation, which could reduce the time of puncture and damage of radiation, shorten the learning curve of puncture for beginners, and has certain clinical feasibility.


Assuntos
Discotomia Percutânea , Deslocamento do Disco Intervertebral , Adulto , Discotomia , Feminino , Humanos , Deslocamento do Disco Intervertebral/cirurgia , Vértebras Lombares/cirurgia , Região Lombossacral , Masculino , Pessoa de Meia-Idade
10.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 51(5): 630-635, 2020 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-32975076

RESUMO

Objective: To investigate the effect of overexpression of miR-382-5p overexpression on malignant biological behavior of human glioma U251 cells. Methods: U251 cells were transfected with miR-382-5pmimic. Then miR-382-5p and PTEN mRNA levels were detected by reverse transcription-polymerase chain reaction (RT-PCR) after transfection. Used bioinformatics to predicted the presence of base binding sites between miR-382-5p and PTEN, and constructed PTEN pcDNA vector overexpression plasmid was constructed. Luciluciase reporting experiment was used to detect the targeting relationship between miR-382-5p and PTEN. Cells were randomly divided into four groups: control group, mimics group, pc-PTEN group and mimics+pc-PTEN group for follow-up experiments. RT-PCR was carried out to detect the level of PTEN mRNA in each group. Cell proliferation was detected by clone formation method. The mRNA levels of Ki67, Survivin and c-Myc were detected by RT-PCR. Transwell experiment was used to assayed cell invasion ability. The expression levels of E-cadherin, N-cadherin and Vimentin were determined by Western blot. Results: Results showed that miR-382-5p directly targeted PTEN. Compared with the control group, miR-382-5p and c-Myc mRNA levels and E-cadherin protein level were increased (P<0.05),PTEN, Ki67 and Survivin mRNA levels were decreased (P<0.05), cell clonal formation rate and cell invasion number were decreased (P<0.05), N-cadherin and Vimentin protein levels were decreased (P<0.05) in the mimics group; In pc-PTEN group, miR-382-5p mRNA and c-Myc mRNA levels and E-cadherin protein level were decreased (P<0.05),PTEN, Ki67 and Survivin mRNA levels were increased (P<0.05), cell clonal formation rate and cell invasion number were increased (P<0.05), N-cadherin and Vimentin protein levels were increased (P<0.05). Compared with pc-PTEN group, PTEN, Ki67 and Survivin mRNA levels, the cell clone formation rate, the number of invasion cells and the N-cadherin and Vimentin levels of mimics+PC-PTEN group decreased significantly (P<0.05), while the c-Myc mRNA level and E-cadherin protein level increased significantly (P<0.05). Conclusion: Overexpression of miR-382-5p mediates the downregulation of PTEN expression, causing the inhibition of the proliferation, invasion, growth and EMT of U251 glioma cells.

11.
J Colloid Interface Sci ; 582(Pt B): 1107-1115, 2020 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-32942066

RESUMO

In this study, we try to find possible solutions to synchronously solving energy and environmental problems. In our design, orange peel is used as a carbon source to synthesize low-cost Fe3O4/C composites, which are employed as adsorbents to purify Cr(vi)-contaminated water. After that, these Cr(vi)-laden Fe3O4/C composites are used and tested as anodes in potassium-ion batteries. It is found that their K-storage capacity is more than 300 mAh g-1 at a current density of 0.1 A g-1, depending on the mass content of Fe3O4. The more Fe3O4 component in composite, the more adsorbed Cr(vi) species through chemisorption, and the larger K-storage capacity. The good electrical conductivity of cabon-based anodes endows them with superior rate performance. At current densities of 0.1, 0.5, 1 and 2 A g-1, K-storage capacity amounts to 357.8, 316.3, 276.3 and 236.8 mAh g-1, respectively. The reuse of contaminant-laden adsorbents as anodes will shed new light on the disposal of exhausted adsorbents after water treatment and development of anode materials for secondary batteries.

12.
Water Sci Technol ; 82(3): 587-602, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32960802

RESUMO

This study focused on using pH as a single indicator to evaluate/control the performance of the nitritation system under the influence of three major operational parameters, and a total of fifteen batch tests were conducted. Results indicated that there were important interactions among different operational parameters and pH in the nitritation system; it was possible to propose the optimal nitritation operation scheme to compensate for negative changes in operational parameters. The optimal carbon to nitrogen (C/N) ratio was kept at 2.0 to ensure efficient removal of ammonium. The reaction time was the lowest (150 min) with the temperature = 20 °C, C/N = 0, and sludge/water ratio = 1:1. However, the C/N ratio could be adjusted to close to zero by reducing the temperature to about 10 °C, weakening the heterotrophic bacteria, and supplying sufficient biomass. The C/N ratio and sludge/water ratio could also be set at 4.0 and 1:3 respectively to deal with the impact of low temperature and organic matter. Results of this study might be useful to explain the optimal conditions and process control schemes with pH as a single indicator.


Assuntos
Compostos de Amônio , Reatores Biológicos , Concentração de Íons de Hidrogênio , Nitritos , Nitrogênio , Esgotos
13.
J Vet Diagn Invest ; 32(6): 928-932, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32996410

RESUMO

North American porcine reproductive and respiratory syndrome virus (NA-PRRSV), especially NADC30-like PRRSV, has evolved and is prevalent in China. We collected 503 samples from pig breeding farms across 4 provinces in northern China from 2016 to 2018. The samples were screened by PCR testing with specific primers that could differentiate groups of NA-PRRSV; phylogenetic trees were constructed and analyzed. Overall, 175 of 503 (34.8%) samples were positive for NA-PRRSV. Dual (NADC30-like and highly pathogenic [HP]-PRRSV; NADC30-like and typical PRRSV; HP and typical PRRSV) and triple (NADC30-like, HP, and typical PRRSV) infections (92 of 175, 52.6%) were common in coinfections by NADC30-like and HP-PRRSV. Notably, 18 of 125 (14.4%) semen samples were positive for PRRSV, and 17 of the 18 positive semen samples contained NADC30-like PRRSV. Phylogenetic analysis based on GP5 amino acids revealed that the novel NADC30-like PRRSV with a unique single amino acid deletion at position 34 has become widespread and has evolved into a new subgroup.

14.
Fish Physiol Biochem ; 46(6): 2227-2242, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32948974

RESUMO

Environmental changes in intensive aquaculture commonly lead to hypoxic stress for cultured largemouth bass (Micropterus salmoides). To better to understand the hypoxic stress response mechanisms, the miRNA expression profiles of the livers of largemouth bass exposed for 24 h to three different dissolved oxygen levels (7.0 ± 0.2 mg/L as control, 3.0 ± 0.2 mg/L and 1.2 ± 0.2 mg/L) were compared. In this study, a total of 266 known miRNAs were identified, 84 of which were differentially expressed compared with the control group. Thirteen of the differentially expressed miRNAs (miR-15b-5p, miR-30a-3p, miR-133a-3p, miR-19d-5p, miR-1288-3p, miR456, miR-96-5p, miR-23a-3p, miR-23b-5p, miR-214, miR-24, miR-20a-3p, and miR-2188-5p) were significantly enriched in VEGF signaling pathway, MAPK signaling pathway, and phosphatidylinositol signaling system. These miRNAs were significantly downregulated during stress, especially after a 4-h exposure to hypoxia. In contrast, their target genes (vegfa, pla2g4a, raf1a, pik3c2a, clam2a, inpp1, pi4k2b, mtmr14, ip6k, itpkca, map3k7, and Jun) were significant upregulated after 4 h of hypoxic stress. Moreover, two potential hypoxia-tolerance signal transduction pathways (MAPK signaling pathway and phosphatidylinositol signaling system) were revealed, both of which may play important roles in responding to acute hypoxic stress. We see that miRNAs played an important role in regulating gene expression related to physiological responses to hypoxia. Potential functional network regulated by miRNAs under hypoixic stress in the liver of largemouth bass (Micropterus salmoides). Blue boxes indicated that the expression of miRNA or target genes were down-regulated. Red boxes indicated that the expression of miRNA or target genes wasere up-regulated.

15.
J Orthop Surg (Hong Kong) ; 28(3): 2309499020959516, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32985369

RESUMO

OBJECTIVE: Despite the wide use of tranexamic acid (TXA) in the perioperative period of total hip arthroplasty (THA), whether the hemostatic state changes after the application of intravenous (IV)-TXA are still unknown. The aim of this study was to investigate whether IV administration of TXA changes the blood coagulation following primary THA via thrombelastography (TEG) analysis and conventional laboratory tests. METHODS: A total of 174 patients who underwent primary THA from September 2016 to July 2018 were selected. They were randomly divided into two groups, 86 patients with IV administration of 15 mg/kg TXA and 88 controls without TXA usage. Demographic data, TEG paremeters, d-dimer levels, fibrin degradation products, hemoglobin, hematocrit concentration, platelet, transfusion rates, perioperative blood loss, and the occurrence of deep vein thrombosis were collected. TEG and conventional laboratory tests were performed the day before operation, the first day after operation, and seventh day after operation. RESULTS: There were no differences with regard to TEG or conventional laboratory tests between the two groups (p > 0.05). The total blood loss and drain blood loss in the TXA group were significantly lower than those in the control group (p < 0.05). The transfusion rates and the volume of blood transfusion of the control group were higher than those of the TXA group (p < 0.05). CONCLUSION: The administration of IV-TXA resulted in a significant reduction in total blood loss, transfusion volumes, and transfusion rates without the increase of thromboembolic complications. Moreover, it was confirmed that TXA would not change the coagulation via the TEG analysis.

17.
Talanta ; 218: 121161, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32797916

RESUMO

In this work, a portable and reliable optical emission spectrometric (OES) instrument based on solid acid hydride generation (HG) and subsequent in situ dielectric barrier discharge (DBD) preconcentration was first developed for simultaneous and field analysis of ultratrace As and Sb in environmental water. In situ DBD fulfilled both gas phase enrichment (GPE) and excitation; effective enrichment made it possible to use a low-cost charge coupled device (CCD) as detector. To simplify field protocol, solid tablet made from sulfamic acid was first used to replace hydrochloric acid for co-generation of As and Sb hydrides. Moisture interference was eliminated by carrier gas sweeping without any desiccant. After calculating peak volume for emission data handling, detection limits (LODs) were 0.5 µg L-1 for As and 0.2 µg L-1 for Sb, respectively, with <3% relative standard deviations (RSDs) at 10 µg L-1; linear dynamic ranges (R2>0.995) were 2-200 µg L-1 for As and 1-200 µg L-1 for Sb, respectively. The results agreed with certified values of CRMs and recoveries were 87-97% vs. inductively coupled plasma mass spectrometry. The running costs can be controlled within one dollar per use. This HG-in situ DBD trap-OES scheme, with demonstrated advantages in sensitivity, low-cost, power (<60 W), size (0.6 m × 0.5 m × 0.3 m), weight (15 kg), gas consumption (300 measurements per 4 L tank), and multi-element capability, was implemented in a miniature spectrometer for field analysis.

18.
Bioorg Med Chem Lett ; 30(21): 127499, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32858124

RESUMO

Agonism of the endothelial receptor APJ (putative receptor protein related to AT1; AT1: angiotensin II receptor type 1) has the potential to ameliorate congestive heart failure by increasing cardiac output without inducing hypertrophy. Although the endogenous agonist, pyr-apelin-13 (1), has shown beneficial APJ-mediated inotropic effects in rats and humans, such effects are short-lived given its extremely short half-life. Here, we report the conjugation of 1 to a fatty acid, providing a lipidated peptide (2) with increased stability that retains inotropic activity in an anesthetized rat myocardial infarction (MI) model. We also report the preparation of a library of 15-mer APJ agonist peptide-lipid conjugates, including adipoyl-γGlu-OEG-OEG-hArg-r-Q-hArg-P-r-NMeLeuSHK-G-Oic-pIPhe-P-DBip-OH (17), a potent APJ agonist with high plasma protein binding and a half-life suitable for once-daily subcutaneous dosing in rats. A correlation between subcutaneous absorption rate and lipid length/type of these conjugates is also reported.

19.
Plant Dis ; 2020 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-32815485

RESUMO

Polygonatum cyrtonema Hua, also known as Huangjing, is an important traditional Chinese herb for treating diabetes and asthma. This plant is commercially planted (approximately 700 ha) in the highland of Anhui Province in China (Liu et al. 2016). In June 2019, brown spots on the leaves of P. cyrtonema Hua were frequently observed in the field in Jinzhai County, Anhui Province. Disease incidence varied from 20 to 30% in a survey site (3 ha) of approximately 25,000 plants. Initially circular or elliptical, reddish colored spots with well-defined brown margin were observed on infected leaves. With time, the spots expanded to large elliptical or shuttle-shaped, pale to dark brown lesions within 10-15 days. To identify the pathogen, symptomatic tissues from the lesion margin were excised from fifteen infected leaves, surface sterilized with 2% NaClO for 2 min, 70% ethanol for 30 s, rinsed three times with sterile water, air dried, plated on potato dextrose agar (PDA) medium supplemented with cefotaxime sodium salt (150 µg/ml), and incubated at 26°C for 3 to 4 days in the dark. Eight morphologically similar fungal isolates were obtained by single-sporing. On PDA, colonies were initially white, and turned pale gray with age. On the reverse side, colonies were initially pale brown and later turned dark black. Conidia were hyaline, curved or slightly curved, aseptate, with a truncate base and acute apex, and measured 14.38 to 20.57 × 2.03 to 5.28 µm (n = 50). The appressoria were solitary, dark brown, ovoid or irregularly shaped, with diameters from 5.61 to 12.43 µm (n = 50). These morphological characteristics are consistent with the description of a Colletotrichum species (Damm et al. 2009). For molecular identification, the primers ITS4/ITS5, T1/T2 and GDF/GDR were used to amplify the partial region of rDNA-ITS, ß-tubulin (TUB2) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from fresh mycelia of all eight isolates, respectively. The resulting sequences of ITS, TUB2 and GAPDH were identical with each other, and sequences from strain PCCS-3 were submitted to Genbank. BlastN revealed that ITS (MN305792), TUB2 (MN307740) and GAPDH (MN307739) shared 99.8%, 100%, 98.8% similarity with the published ITS, TUB2 and GADPH sequences from the ex-epitype culture of C. spaethianum CBS 167.49 (Damm et al. 2009), respectively. To prove Koch's postulates, a pathogenicity test was conducted by spraying 3 ml of conidial suspension of each the eight isolates (105 conidia/ml) on three-month-old healthy P. cyrtonema seedlings (3 seedlings per isolate). As a control, three seedlings were sprayed with 3 ml of distilled water. All inoculated plants were maintained in a moist chamber (RH>90%) at 26°C, with an 8-h photoperiod under fluorescent light. The disease assays were repeated thrice. Brown spots identical to those observed in field were noted 7 to 10 days after inoculation, whereas control plants remained symptomless. The same pathogen was reisolated and confirmed as C. spaethianum by sequencing of ITS, GAPDH and Tub2, fulfilling Koch's postulates. Presently, C. spaethianum causing leaf spot on Polygonatum odoratum was reported from Jilin Province in China (Liu et al. 2020). To our knowledge, this is the first report of C. spaethianum infecting P. cyrtonema in Anhui Province, China. Our result expanded the geographic location of C. spaethianum as the pathogen on plants belonging to Asparagaceae family in China, and effective control strategies need to be considered to minimize the losses.

20.
BMC Cancer ; 20(1): 667, 2020 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-32680466

RESUMO

BACKGROUND: Lymph node metastasis in the cervical region posterior to level V (PLV) can occurs in patients with nasopharyngeal carcinoma (NPC), but the significance of lymph node metastasis in this region and the delineation of the radiotherapy target area have not been reported. We aimed to explore the distribution pattern and prognosis of metastatic lymph nodes in the PLV region in patients with NPC. METHODS: We retrospectively studied 605 cases of NPC diagnosed by pathological detection from December 2011 to November 2017. The nodal distribution at each level was assessed in accordance with the Radiation Therapy Oncology Group (RTOG) guidelines proposed in 2013. The central points of the metastatic lymph nodes of the PLV region in the patients were recreated proportionally on the CT images of a standard patient with N0 NPC in reference to the normal anatomy of the PLV area. The correlation between the PLV region and the other levels, the nodal location, and the characteristics and prognosis of the PLV region were analyzed. RESULTS: Lymph node metastasis occurred in 557 (92.06%) of 605 patients. There were 30 patients (4.95%) with lymph node metastasis in the PLV region. A total of 49 metastatic lymph nodes from the PLV region were counted, and the mean vertical distance of the central point of each lymph node from the anterior surface of the trapezius muscle was 14 mm. Linear regression correlation analysis suggested that lymph node metastasis in the PLV region was associated with ipsilateral level IVa (P = 0.018), level Va, level Vb, and level Vc lymph node metastasis (all P <  0.001). The 5-year OS, PFS, LRFS, and DMFS of 29 patients with lymph node metastasis in the PLV region were 41.6, 27.7, 89.1, and 47.3%, respectively. Multivariate analysis showed that lymph node metastasis in the PLV region was an independent prognostic factor for DMFS (P <  0.05). CONCLUSION: NPC patients with lymph node metastasis in the PLV region had a poor prognosis and a high risk of distant metastasis. We recommend that the margin of the PLV region may be a new cervical lymph node segment for NPC.

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