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1.
Phytomedicine ; 84: 153495, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33611210

RESUMO

BACKGROUND: Ulcerative colitis (UC) is a chronic relapsing inflammatory disease that markedly elevates the risk of colon cancers and results in disability. The disrupted immune homeostasis has been recognized as a predominant player in the pathogenesis of UC. However, the overall remission rate of current therapies based on immunoregulation is still unsatisfactory. Si-Ni-San (SNS) has been found effective in relieving UC through thousands of years of clinical practice, yet the specific mechanisms of the protective effect of SNS were not fully elucidated. PURPOSE: We aim to investigate the therapeutic effects of SNS against the development of chronic colitis and the underlying mechanisms. METHODS: We established a DSS-induced chronic experimental colitis mouse model to evaluate the effect of SNS. RNA-sequencing, bioinformatic analysis, and in vitro studies were performed to investigate the underlying mechanisms. RESULTS: Our data demonstrated that SNS significantly ameliorated chronic experimental colitis via inhibiting the expression of genes associated with inflammatory responses. Interestingly, SNS significantly suppressed DSS-induced type I interferon (IFN) responses instead of directly downregulating the production of pro-inflammatory cytokines, such as Il-6. In vitro study further found that SNS selectively inhibited STING and RIG-I pathway-induced type I IFN responses by modulating TBK1- and IRF3-dependent signaling transduction. SNS also suppressed the expression of IFN-stimulated genes by directly inhibiting STAT1 and STAT2 activation. CONCLUSION: Our study not only provides novel insights into the pathogenic role of type I IFN responses in colitis but also suggested that SNS or bioactive compounds derived from SNS may serve as novel therapeutic strategies for the treatment of UC via interfering type I IFN-mediated inflammation.

2.
Plant Biotechnol J ; 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33567155

RESUMO

A few reports have indicated that a single gene confer resistance to bacterial blight, sheath blight, and rice blast. In this study, we identified a novel disease resistance mutant gene, methyl esterase-like (osmesl) in rice. Mutant rice with T-DNA insertion displayed significant resistance to bacterial blight caused by Xanthomonas oryzae pv. oryzae (Xoo), sheath blight caused by Rhizoctonia solani and rice blast caused by Magnaporthe oryzae. Additionally, CRISPR-Cas9 knockout mutants and RNAi lines displayed resistance to these pathogens. Complementary T-DNA mutants demonstrated a phenotype similar to the wild type (WT), thereby indicating that osmesl confers resistance to pathogens. Protein interaction experiments revealed that OsMESL affects reactive oxygen species (ROS) accumulation by interacting with thioredoxin OsTrxm in rice. Moreover, qRT-PCR results showed significantly reduced mRNA levels of multiple ROS scavenging-related genes in osmesl mutants. Nitroblue tetrazolium staining showed that the pathogens cause ROS accumulation, and quantitative detection revealed significantly increased levels of H2 O2 in the leaves of osmesl mutants and RNAi lines after infection. The abundance of JA, a hormone associated with disease resistance, was significantly more in osmesl mutants than in WT plants. Overall, these results suggested that osmesl enhances disease resistance to Xoo, R. solani and M. oryzae by modulating the ROS balance.

4.
Eur Radiol ; 2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33409796

RESUMO

OBJECTIVES: To develop a nanoparticle-based MRI protocol based on transrectal administration of intestine-absorbable nanoparticle contrast agents to evaluate ulcerative colitis (UC). METHODS: Solid lipid nanoparticles (SLNs) were synthesized by loading gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) and octadecylamine-fluorescein isothiocyanate to produce Gd-FITC-SLNs as T1 contrast agents. Twenty mice with acute UC were divided into four groups: enema with Gd-FITC-SLNs, intravenous injection of Gd-FITC-SLNs, enema with Gd-DTPA, and intravenous injection of Gd-DTPA. Five mice with chronic UC and five mice without UC underwent enema with Gd-FITC-SLNs. Axial T1- and T2-weighted MR images were obtained before and 20, 40, 60, 80,100, and 120 min after enema or intravenous injection of the contrast agent. The signal-to-noise ratios (SNRs) of the colorectal wall were measured in both groups. The MRI findings were correlated with subsequent histological confirmation. RESULTS: At 20 min after enema with Gd-FITC-SLNs, MRI showed the following contrast enhancement pattern: acute UC > normal intestinal wall > chronic UC. A continuous enhancement effect was observed in mice with acute UC, whereas a slight continuous enhancement of the colorectal wall was observed in mice with chronic UC. The normal intestinal wall rapidly metabolized the contrast agent, and the enhancement decreased on sequential scans. There was no significant difference between the SNRs of the intestinal wall at 20 min after intravenous Gd-DTPA and transrectal Gd-FITC-SLN administration. CONCLUSIONS: Enema with Gd-FITC-SLNs may be helpful for the diagnosis and differential diagnosis of acute and chronic UC and can confer the same or better results than with intravenous Gd-DTPA. KEY POINTS: • Enema with Gd-FITC-SLNs may be helpful for the diagnosis and differential diagnosis of acute and chronic UC. • Enema with Gd-FITC-SLNs can achieve the same or better result than that with intravenous Gd-DTPA. • SLN-based MR colonography enhances the colorectal wall inflammation, based on the colonic absorption of the nanoparticle contrast agents.

6.
Nature ; 589(7841): 214-219, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33408416

RESUMO

Quantum key distribution (QKD)1,2 has the potential to enable secure communication and information transfer3. In the laboratory, the feasibility of point-to-point QKD is evident from the early proof-of-concept demonstration in the laboratory over 32 centimetres4; this distance was later extended to the 100-kilometre scale5,6 with decoy-state QKD and more recently to the 500-kilometre scale7-10 with measurement-device-independent QKD. Several small-scale QKD networks have also been tested outside the laboratory11-14. However, a global QKD network requires a practically (not just theoretically) secure and reliable QKD network that can be used by a large number of users distributed over a wide area15. Quantum repeaters16,17 could in principle provide a viable option for such a global network, but they cannot be deployed using current technology18. Here we demonstrate an integrated space-to-ground quantum communication network that combines a large-scale fibre network of more than 700 fibre QKD links and two high-speed satellite-to-ground free-space QKD links. Using a trusted relay structure, the fibre network on the ground covers more than 2,000 kilometres, provides practical security against the imperfections of realistic devices, and maintains long-term reliability and stability. The satellite-to-ground QKD achieves an average secret-key rate of 47.8 kilobits per second for a typical satellite pass-more than 40 times higher than achieved previously. Moreover, its channel loss is comparable to that between a geostationary satellite and the ground, making the construction of more versatile and ultralong quantum links via geosynchronous satellites feasible. Finally, by integrating the fibre and free-space QKD links, the QKD network is extended to a remote node more than 2,600 kilometres away, enabling any user in the network to communicate with any other, up to a total distance of 4,600 kilometres.

8.
Sci Total Environ ; 770: 144664, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33513517

RESUMO

Selenium (Se) content of crops depends on the local soil Se content and/or its bioavailability, and identifying the influence factors of soil Se bioavailability is a significant basis for adopting targeted agronomic measures to improve the Se nutritional status of humans. In this study, the main wheat-producing region in Shaanxi province with similar parent material and climate conditions was selected as the study area. The total Se contents of 602 soil samples and their corresponding wheat grains were determined, and the distribution characteristics of soil Se bioavailability and its dominant influential factors were investigated. Results showed that the total Se content ranged from 0.02 mg/kg to 1.67 mg/kg (average of 0.25 ± 0.25 mg/kg) in soil, which was lower than that content in China (0.29 mg/kg). The Se content of wheat grain was 0.001-1.50 mg/kg (average of 0.11 ± 0.19 mg/kg). The distribution trend of the Se content in wheat grains was different from that of the total soil Se, but it was consistent with the distribution of soil bioavailable Se content. The bioavailable Se accounted for 11.1% of the total soil Se. This could be attributed to relatively high soil Se bioavailability of the study area belonging to alkaline soil (with a pH of approximately 8). Both redundancy analysis and path analysis revealed that soil pH and organic matter were the dominant influential factors of soil Se bioavailability in Shaanxi wheat-producing area, and the soil Se bioavailability increased with these two parameters raising. On this basis, a prediction model was established to predict the Se content in wheat grain. The results show that the various agronomic measures could be used to produce Se-enriched wheat by regulating the soil pH and the organic matter content in Se biofortification practice.

10.
Lung Cancer ; 153: 66-72, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33454519

RESUMO

PURPOSE: The distribution of genetic mutations differs between pure pulmonary sarcomatoid carcinoma (PSC) and biphasic PSC; however, most of the enrolled cases in previous studies are biphasic PSC. The current study aimed to investigate the genomic and immunologic profiles of pure PSC in the Chinese population. MATERIALS AND METHODS: Next-generation sequencing analysis of a panel of 1021 genes was performed on surgical specimens of 58 pure PSCs. The tumor mutational burden (TMB) was calculated from 0.69 megabases (Mbs) of sequenced DNA. PD-L1 expression was evaluated by immunohistochemistry. Microsatellite instability (MSI) was evaluated by fluorescence-labeled microsatellite marker polymerase chain reaction followed by capillary electrophoresis fragment size analysis. RESULTS: The top mutational genes of pure PSC were TP53 (74 %, 43/58), KRAS (24 %, 14/58), SMARCA4 (14 %, 8/58), MET (12 %, 7/58), EGFR (10 %, 6/58), MLL4 (10 %, 6/58), NF1 (10 %, 6/58), NOTCH4 (10 %, 6/58), and TERT (10 %, 6/58). The median TMB was 8.6 mutations/Mb; 37.9 % of cases (22/58) had a TMB > 10 mutations/Mb and 12.1 % of cases (7/58) had a TMB > 20 mutations/Mb. The median TMB was higher in TP53-mutant tumors than in wild-type tumors (10.1 versus 7.2 mutations/Mb, p = 0.019). Thirty-five patients had microsatellite-stable pure PSC, and four patients carried MSI-H tumors. The MSI status was independent of MET exon 14 status. Twenty-six patients (45 %) had PD-L1-positive tumors (≥1%) and 14 (24 %) had high PD-L1 expression (≥50 %). CONCLUSION: In our cohort, 45 % of patients with pure PSC harbored at least one actionable alteration. More importantly, more than 60 % of patients (65.5 %, 38/58) had either MSI-H, PD-L1-positive, or high-TMB tumors, and these might derive survival benefits from immune checkpoint inhibitors.

11.
Lung Cancer ; 153: 143-149, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33508527

RESUMO

INTRODUCTION: Previous clinical investigations have demonstrated that patients with non-small-cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutation have moderate responses to programmed cell death-1 and it's ligand-1 (PD-1/PD-L1) inhibitors, while some patients who failed EGFR-tyrosine kinase inhibitor (TKI) therapy could benefit from immunotherapy. As a result, we have explored alterations in the tumor immune microenvironment (TIME) before and after EGFR-TKI treatment to detect the chances and proper timing of immunotherapy among patients. METHODS: We identified 16 paired tissue samples pre- and post-EGFR-TKI treatment. Sections 4 µm thick were utilized to evaluate CD8, PD-L1, PD-1, LAG-3, and TIM-3 expressions by multiplexed fluorescent immunohistochemical staining. Five to ten representative original multispectral images of each sample were employed in the analysis. RESULTS: Patients with positive CD8 + T-cell infiltration accounted for 37.5 % at baseline. Positive expression of PD-L1, PD1, LAG-3, and TIM-3 cells were observed in seven (43.8 %), four (25 %), one (6.25 %) and five (31.25 %) of the patients, respectively. PD-1 expression and infiltration of CD8+PD-1+-exhausted T cells increased significantly in patients with EGFR L858R mutation compared to patients with EGFR 19DEL. Patients who acquired T790 M after TKI treatment had less infiltrations of CD8+PD-1+ T cells and CD8+TIM-3+ T cells in the TIME at baseline. Positive expression of checkpoint proteins-including PD-1, TIM-3, and LAG-3-significantly correlated with shorter progression-free survival. LAG-3 was significantly upregulated after TKI treatment (p = 0.003), while other checkpoint proteins remained stationary. CONCLUSION: The present study is the first work to report LAG-3 upregulation after EGFR-TKI failure in advanced NSCLC, which proposed novel insights for rational use of LAG-3 inhibitors in advanced NSCLC patients with EGFR mutation.

12.
Curr Opin Oncol ; 33(1): 87-94, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33122578

RESUMO

PURPOSE OF REVIEW: Despite the significant advances in EGFR-mutant nonsmall cell lung cancer (NSCLC), some challenges remain. One of the permanent and inevitable issues is the emergence of acquired resistance. Therefore, blocking the activation of EGFR pathway and overcoming drug resistance with novel agents are still in high demand. Here, we review the development of novel drugs in EGFR-mutant, advanced NSCLC, including targeting EGFR exon 20 insertion (EGFR20ins), and novel role of epidermal growth factor receptor, tyrosine kinase inhibitor (EGFR-TKIs) in early-stage NSCLC. RECENT FINDINGS: EGFR-TKIs as adjuvant therapy or neoadjuvant therapy in patients with early-stage NSCLC with EGFR-sensitizing mutations have shown promising efficacy. The resistance mechanisms of third-generation EGFR-TKIs can be divided into two types: EGFR dependent and EGFR independent. Several clinical trials have demonstrated that the addition of MET inhibitors to EGFR-TKIs was an effective option for patients who had acquired resistance to EGFR-TKIs caused by hepatocyte growth factor receptor gene (MET) amplification or overexpression. Novel compounds that selectively and potently inhibit EGFR20ins are being investigated in phase III studies. SUMMARY: A better characterization and understanding of resistance mechanisms to first-line osimertinib and adjuvant osimertinib is helpful to guide further treatment.

13.
Food Chem ; 338: 127661, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32882487

RESUMO

Understanding the effects of processing on the Se content and bioaccessibility in food is critical in guiding the development of Se-enriched products. In this study, Se-enriched Pleurotus eryngii was obtained by applying different Se supplements to the substrate. Selenium content and its bioaccessibility among raw and processed fruit bodies were compared. The application of exogenous Se had no significant effect on the yield of P. eryngii, while amendment Se yeast could slightly promote the growth of P. eryngii. The enrichment ability of P. eryngii among different Se supplements declined in the order of Na2SeO3 > Se yeast > Na2SeO4. However, the processing treatments resulted in 6.6%-45.9% Se loss. The Se bioaccessibility of P. eryngii was 78.4%-89.7%. Frying treatment reduced Se bioaccessibility in samples, whereas boiling treatment enhanced it. Therefore, Se yeast and boiling treatment are recommended as the ideal Se supplement and processing method for Se-enriched P. eryngii.


Assuntos
Pleurotus/química , Selênio/química , Biotransformação , Suplementos Nutricionais/análise , Pleurotus/crescimento & desenvolvimento , Pleurotus/metabolismo , Selênio/metabolismo , Fermento Seco/química
14.
Medicine (Baltimore) ; 99(52): e23831, 2020 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-33350770

RESUMO

ABSTRACT: The International Society on Thrombosis and Haemostasis (ISTH) scoring system has been used for diagnosing overt disseminated intravascular coagulation (DIC). However, the cut-off points of fibrin-related markers remain unclear. The ability of the ISTH DIC score and Multiple Organ Dysfunction (MODS) score to predict mortality in cases of exertional heat illness (EHI) was tested. In the process, 3 different D-dimer cut-off values for diagnosing overt DIC were evaluated.Data were obtained on the first day of hospitalization for 76 patients with EHI. The DIC score was calculated according to the ISTH scoring system using 3 D-dimer cut-off values.In predicting mortality, methods 1 and 2 had the same sensitivity and specificity, which were 85% and 73.2%, respectively. The sensitivity for method 3 was 70%. Furthermore, the specificity of the DIC score for method 3 was 89%, which was higher than that of the other 2 methods. The correlation coefficients of the DIC and MODS scores of these 3 methods were 0.757, 0.748, and 0.756, respectively. For the prediction of mortality, the area under the receiver operating characteristic (ROC) curve for the DIC scores of these 3 methods was 0.838, 0.842, and 0.85, respectively. Furthermore, the area under the ROC curve of the MODS score was 0.927.The DIC score had a certain predictive power of a poor outcome of EHI patients, but this was not better than the MODS score. The present data may serve as a reference in selecting the appropriate D-dimer cut-off point for the ISTH DIC score.


Assuntos
Coagulação Intravascular Disseminada , Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Transtornos de Estresse por Calor , Escores de Disfunção Orgânica , Adulto , China , Coagulação Intravascular Disseminada/sangue , Coagulação Intravascular Disseminada/diagnóstico , Feminino , Transtornos de Estresse por Calor/sangue , Transtornos de Estresse por Calor/diagnóstico , Transtornos de Estresse por Calor/mortalidade , Humanos , Masculino , Avaliação de Resultados em Cuidados de Saúde/métodos , Valor Preditivo dos Testes , Prognóstico , Curva ROC , Projetos de Pesquisa/normas , Sensibilidade e Especificidade
15.
Food Chem Toxicol ; 146: 111827, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33184029

RESUMO

Acteoside is one of the most widespread phenylethanoid glycosides with pharmacological activities, including antioxidant, neuroprotective property, etc. However, its bioavailability is poor due to the low absorption and P-gp efflux. This study aimed to select food derived P-gp inhibitors for promoting the acteoside absorption and investigate whether the inhibitors could increase the bioavailability and stability of acteoside. Results showed that EGCG and quercetin significantly decreased the BL-to-AP efflux and promoted the AP-to-BL influx of acteoside across Caco-2 monolayers with optimum concentrations of 320 µM EGCG or 240 µM quercetin adding to 320 µM acteoside. EGCG increased the bioavailability of acteoside to 1.43-fold, but quercetin had no such effect. Further study showed that EGCG and quercetin had no effects on the storage and digestion stability of acteoside. This work revealed that EGCG could improve the acteoside absorption across the Caco-2 monolayers and enhance the bioavailability of acteoside in rats.

16.
Sci Total Environ ; : 143119, 2020 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-33158520

RESUMO

Selenium (Se) bioaccessibility in soil and crops from seleniferous areas is closely relevant to Se intake risks of local residents. The current in vitro digestion methods used for Se bioaccessibility evaluation are single and inconsistent, and most of them are only for food and neglect soil. In this study, 14 Se-contaminated soils and their corresponding crops in Naore Village (seleniferous area) were used as the research objects. Four in vitro digestion assays, including Solubility Bioaccessibility Research Consortium method (SBRC), physiologically-based extraction test (PBET), in vitro gastrointestinal method (IVG), and Unified Bioaccessibility Method (UBM) were used to determine the bioaccessible Se concentration in soil and edible parts of crops. Results showed that the Se in natural seleniferous soil mainly existed in relatively stable forms, i.e., residual and Fe-Mn oxide-bound Se (average of 80%). Only 10.6% of the total Se was distributed in water-soluble and exchangeable Se fractions. The Se content in crops was significantly positively correlated with the organic-bound and phosphate-extractable Se contents in the corresponding soil (p < 0.05). The organic-bound Se was clearly a potentially bioavailable Se source in soil. The Se bioaccessibility in soil and crops measured using the four in vitro methods in gastric/intestinal digestions were in the same order, which was PBET > UBM > SBRC > IVG. Similar to the absorption and utilization of soil Se fractions by crops, the water-soluble, organic-bound and exchangeable Se in soil were the main contributors of bioaccessible Se in the digestive juices in various in vitro methods. Furthermore, the bioaccessible Se in crops and soil measured via PBET method demonstrated the most significant correlation between the total Se in crops and the phosphate-extractable Se in soil. Therefore, the PBET method was the optimum in vitro method for the evaluation of Se bioaccessibility in crops and soil.

17.
Front Oncol ; 10: 595466, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33194761

RESUMO

Radiation resistance is linked to immune escaping and radiation sensitivity. In this study, we found that the PD-L1 expressions of non-killed tumor cells in NSCLC were enhanced after radiotherapy, and dihydroartemisinin (DHA) could synergistically enhance the antitumor effect of radiotherapy in NSCLC. A total of 48 NSCLC patients with sufficient tumor tissues for further analyses were enrolled. The PD-L1 expressions of NSCLC were evaluated by immunohistochemistry. Cell apoptosis was measured by flow cytometry, and the relationship between the PD-L1 expression and radiation resistance was investigated in patient specimens, xenograft model, and cell lines. First, the results indicate that the PD-L1 expression of NSCLC was positively related with the radiation resistance. Second, we found that DHA could eliminate the radiation resistance and synergistically enhance the antitumor effect of radiotherapy in the NSCLC cells lines and xenograft model. Finally, mechanistically, DHA could inhibit the PD-L1 expression to avoid immune escaping by inhibiting TGF-ß, PI3K/Akt, and STAT3 signaling pathways. In addition, DHA could activate TRIM21 and regulate the EMT-related proteins by inhibiting the PD-L1 so as to enhance the radiation sensitivity and eliminate radiation resistance to NSCLC. Collectively, this study established a basis for the rational design of integrated radiotherapy and DHA for the treatment of NSCLC.

18.
Pest Manag Sci ; 2020 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-33201594

RESUMO

BACKGROUND: Weeds, diseases and pests pose serious threats to rice production and cause significant economic losses. Cultivation of rice varieties with resistance to herbicides, diseases and pests is believed to be the most economical and environment-friendly method to deal with these problems. RESULTS: In this study, a highly efficient transgene stacking system was used to assembly the synthetic glyphosate-tolerance gene (I. variabilis-EPSPS*), lepidopteran pest resistance gene (Cry1C*), brown planthopper resistance genes (Bph14* and OsLecRK1*), bacterial blight resistance gene (Xa23*) and rice blast resistance gene (Pi9*) onto a TAC vector. The construct was transferred into ZH11 (a widely used japonica rice cultivar Zhonghua 11) via Agrobacterium-mediated transformation, and "multi-resistance rice" (MRR) with desirable agronomic traits was obtained. The results showed that MRR had significantly improved resistance to glyphosate, borers, brown planthopper, bacterial blight and rice blast relative to the recipient cultivar ZH11. Besides, under the natural occurrence of pests and diseases in the field, the yield of MRR was significantly higher than that of ZH11. CONCLUSION: A multi-gene transformation strategy was employed to successfully develop rice lines with multi-resistance to glyphosate, borers, brown planthopper, bacterial blight and rice blast, and the obtained MRR is expected to have great application potential.

19.
Cell Mol Immunol ; 2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33177696

RESUMO

Great advances in immune checkpoint blockade have resulted in a paradigm shift in patients with lung cancer. Immune-checkpoint inhibitor (ICI) treatment, either as monotherapy or combination therapy, has been established as the standard of care for patients with locally advanced/metastatic non-small cell lung cancer without EGFR/ALK alterations or extensive-stage small cell lung cancer. An increasing number of clinical trials are also ongoing to further investigate the role of ICIs in patients with early-stage lung cancer as neoadjuvant or adjuvant therapy. Although PD-L1 expression and tumor mutational burden have been widely studied for patient selection, both of these biomarkers are imperfect. Due to the complex cancer-immune interactions among tumor cells, the tumor microenvironment and host immunity, collaborative efforts are needed to establish a multidimensional immunogram to integrate complementary predictive biomarkers for personalized immunotherapy. Furthermore, as a result of the wide use of ICIs, managing acquired resistance to ICI treatment remains an inevitable challenge. A deeper understanding of the underlying biological mechanisms of acquired resistance to ICIs is helpful to overcome these obstacles. In this review, we describe the cutting-edge progress made in patients with lung cancer, the optimal duration of ICI treatment, ICIs in some special populations, the unique response patterns during ICI treatment, the emerging predictive biomarkers, and our understanding of primary and acquired resistance mechanisms to ICI treatment.

20.
J Orthop Surg Res ; 15(1): 537, 2020 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-33203406

RESUMO

BACKGROUND: To evaluate the biomechanical properties of short-segment Schanz screw implanted in an oblique downward direction for the treatment of lumbar 1 burst fracture using a finite element analysis. METHODS: The Universal Spine System (USS) fixation model for adjacent upper and lower vertebrae (T12 and L2) of lumbar 1 vertebra burst fracture was established. During flexion/extension, lateral bending, and rotation, the screw stress and the displacement of bone defect area of the injured vertebrae were evaluated when the downward inserted angle between the long axis of the screws and superior endplate of the adjacent vertebrae was set to 0° (group A), 5° (group B), 10° (group C), and 15°(group D). There were 6 models in each group. RESULTS: There were no significant differences in the maximum screw stress among all the groups during flexion/extension, lateral bending, and rotation (P > 0.05). There were no significant differences in the maximum displacement of the bone defect area of the injured vertebrae among all the groups during flexion/extension, lateral bending, and rotation (P > 0.05). CONCLUSION: Short-segment Schanz screw implanted in an oblique downward direction with different angles (0°/parellel, 5°, 10°, and 15°) did not change the maximum stress of the screws, and there was a lower risk of screw breakage in all groups during flexion/extension, lateral bending, and rotation. In addition, the displacement of the injured vertebra defect area had no significant changes with the change of angles.

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