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1.
Mol Cancer Ther ; 2020 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-32220969

RESUMO

Renal cell carcinoma (RCC) bone metastases (RCCBM) are typically osteolytic. We previously showed that BIGH3 (beta Ig-h3/TGFbI), secreted by 786-O RCC, plays a role in osteolytic bone lesion in RCCBM through inhibition of osteoblast (OSB) differentiation. To study this interaction, we employed three-dimensional (3D) hydrogels to co-culture bone-derived 786-O RCC cells (Bo-786) with MC3T3-E1 pre-osteoblasts (OSB). Culturing pre-osteoblasts in the 3D hydrogels preserved their ability to differentiate into mature OSB; however, this process was decreased when pre-osteoblasts were co-cultured with Bo-786 cells. Knockdown of BIGH3 in Bo-786 cells recovered OSB differentiation. Further, treatment with bone morphogenetic protein 4 (BMP4), which stimulates osteoblast differentiation, or cabozantinib (CBZ), which inhibits VEGFR1 and MET tyrosine kinase activities, also increased OSB differentiation in the co-culture. CBZ also inhibited pre-osteoclast RAW264.7 cell differentiation. Using RCCBM mouse models, we showed that CBZ inhibited Bo-786 tumor growth in bone. CBZ treatment also increased bone volume and OSB number, and decreased osteoclast number and blood vessel density. When tested in SN12PM6 RCC cells that have been transduced to overexpress BIGH3, CBZ also inhibited SN12PM6 tumor growth in bone. These observations suggest that enhancing OSB differentiation could be one of the therapeutic strategies for treating RCCBM that exhibit OSB inhibition characteristics, and that this 3D co-culture system is an effective tool for screening osteoanabolic agents for further in vivo studies.

2.
World Neurosurg ; 2020 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-32081827

RESUMO

BACKGROUND: Surgical resection of intramedullary tumors remains technically challenging. The role of intraoperative ultrasound and contrast-enhanced ultrasound (CEUS) in these surgeries has not yet been well defined. This study was aimed to evaluate the potential of intraoperative ultrasonography, especially CEUS, in visualizing intramedullary spinal cord tumors, and to assess the values for improving surgical outcomes. METHODS: This prospective study recruited 14 patients with intramedullary spinal cord tumor. All patients underwent tumor resection with intraoperative ultrasound and CEUS. The first ultrasonographic scanning was performed before the dural incision. After the dural incision, further ultrasonographic scanning was performed over the surface of the spinal cord. During and after the tumor removal, repeat ultrasonographic scanning was conducted to assess the extent of surgical resection. Follow-up data were collected and analyzed. RESULTS: Seven patients had small tumors involving 1 or 2 spinal segments, and 7 patients showed relatively large tumors involving ≥3 spinal segments. Intraoperatively, ultrasonography was able to visualize the lesion clearly in all cases. Using intraoperative ultrasound with CEUS, the tumor boundaries were clearly defined. After an average follow-up period of 15.93 months, neurologic function improved in 10 cases (71.4%) and remained unchanged in 4 cases (28.6%); there was no deterioration in individual neurologic function. CONCLUSIONS: Intraoperative ultrasound is of great value for localizing lesions and determining the extent of dural opening and myelotomy, therefore reducing the invasiveness of spinal surgery for intramedullary tumors. CEUS helps to delineate the tumor margins and perfusion features.

3.
Acc Chem Res ; 53(3): 547-560, 2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32077681

RESUMO

ConspectusElectrochemistry has been used as a tool to drive chemical reactions for over two centuries. With the help of an electrode and a power source, chemists are bestowed with an imaginary reagent whose potential can be precisely dialed in. The theoretically infinite redox range renders electrochemistry capable of oxidizing or reducing some of the most tenacious compounds (e.g., F- to F2 and Li+ to Li0). Meanwhile, a granular level of control over the electrode potential allows for the chemoselective differentiation of functional groups with minute differences in potential. These features make electrochemistry an attractive technique for the discovery of new modes of reactivity and transformations that are not readily accessible with chemical reagents alone. Furthermore, the use of an electrical current in place of chemical redox agents improves the cost-efficiency of chemical processes and reduces byproduct generation. Therefore, electrochemistry represents an attractive approach to meet the prevailing trends in organic synthesis and has seen increasingly broad use in the synthetic community over the past several years.While electrochemical oxidation or reduction can provide access to reactive intermediates, redox-active molecular catalysts (i.e., electrocatalysts) can also enable the generation of these intermediates at reduced potentials with improved chemoselectivity. Moreover, electrocatalysts can impart control over the chemo-, regio-, and stereoselectivities of the chemical processes that take place after electron transfer at electrode surfaces. Thus, electrocatalysis has the potential to significantly broaden the scope of organic electrochemistry and enable a wide range of new transformations. Our initial foray into electrocatalytic synthesis led to the development of two generations of alkene diazidation reactions, using transition-metal and organic catalysis, respectively. In these reactions, the electrocatalysts play two critical roles; they promote the single-electron oxidation of N3- at a reduced potential and complex with the resultant transient N3• to form persistent reactive intermediates. The catalysts facilitate the sequential addition of 2 equiv of azide across the alkene substrates, leading to a diverse array of synthetically useful vicinally diaminated products.We further applied this electrocatalytic radical mechanism to the heterodifunctionalization of alkenes. Anodically coupled electrolysis enables the simultaneous anodic generation of two distinct radical intermediates, and the appropriate choice of catalyst allowed the subsequent alkene addition to occur in a chemo- and regioselective fashion. Using this strategy, a variety of difunctionalization reactions, including halotrifluoromethylation, haloalkylation, and azidophosphinoylation, were successfully developed. Importantly, we also demonstrated enantioselective electrocatalysis in the context of Cu-promoted cyanofunctionalization reactions by employing a chiral bisoxazoline ligand. Finally, by introducing a second electrocatalyst that mediates oxidatively induced hydrogen atom transfer, we expanded scope of electrocatalysis to hydrofunctionalization reactions, achieving hydrocyanation of conjugated alkenes in high enantioselectivity. These developments showcase the generality of our electrocatalytic strategy in the context of alkene functionalization reactions. We anticipate that electrocatalysis will play an increasingly important role in the ongoing renaissance of synthetic organic electrochemistry.

4.
J Chem Ecol ; 2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-32016775

RESUMO

Polyphenol oxidases (PPOs) as inducible defense proteins, contribute to tea (Camellia sinensis) resistance against tea geometrid larvae (Ectropis grisescens), and this resistance has been associated with the jasmonic acid (JA) signaling by testing geometrid performance in our previous work. However, the regulation of PPO-based defense by JA and other hormone signaling underlying these defense responses is poorly understood. Here, we investigated the role of phytohormones in regulating the PPO response to tea geometrids. We profiled levels of defense hormones, PPO activity and CsPPO genes in leaves infested with tea geometrids. Then, hormone levels were manipulated by exogenous application of methyl jasmonate (MeJA), gibberellin acid (GA3), abscisic acid (ABA), JA biosynthesis inhibitors (sodium diethyldithiocarbamate trihydrate, DIECA and salicylhydroxamic acid, SHAM) and GA inhibitor (uniconazole, UNI). Upon geometrid attack, JA levels significantly increased, whereas GA levels notably decreased and ABA level was slightly decreased. And the PPO activity significantly increased in line with the transcript levels of CsPPO2 and CsPPO4 but not CsPPO1. There were an obvious antagonistic cross-talk between JA and GA signals and an association among JA signals, PPO response and herbivore resistance in tea plants. Pretreatment with MeJA increased PPO activity by activating the transcripts of CsPPO2 and CsPPO4, whereas application of JA inhibitor DIECA suppressed PPO activity. GA3 strongly enhanced PPO activity, but ABA did not alter PPO activity. These findings strongly suggest that JA is a central player in PPO-mediated tea resistance against tea geometrids in a manner that prioritizes defense over growth.

6.
Anal Bioanal Chem ; 412(5): 1215-1234, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31940090

RESUMO

Acute lung injury (ALI) is a clinically common and serious disease, underscoring the urgent need for clarification of its pathogenesis. According to traditional Chinese medicine (TCM) theories on the "lung-spleen-intestine axis" and its correlation with ALI, a high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-QTOF-MS) metabolomic platform was applied to identify biomarkers from five bio-samples of control and model rats challenged with intratracheally administered lipopolysaccharide (LPS) based on multivariate mathematical statistical analysis. As a result, 19, 24, 24, 15 and 29 altered metabolites were identified in serum, lung, bronchoalveolar lavage fluid (BALF), spleen and feces samples, respectively. Metabolic pathway analysis showed that linoleic acid, sphingolipid, glycerophospholipid and bile acid metabolism pathways were mainly altered by ALI. Additionally, ROC curves were applied to assess the specificity and sensitivity of the biomarkers. ALI characteristic metabolomic spectra were then established to differentiate the control from the model group with a similarity discriminative threshold of 0.7. Additionally, to compare the metabolomic profiles of the five bio-samples and establish metabolic similarities and differences among them, correlation analysis was conducted in order to delineate an objective law of endogenous linkage along the lung-spleen-intestine axis. Therefore, this study provides insights into the mechanisms involved in ALI from a metabolomics perspective, which can be applied in characterization of the mechanism and early disease detection. Graphical abstract.

7.
J Phys Chem Lett ; 11(3): 960-967, 2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-31957438

RESUMO

InP quantum dots (QDs) are considered as one of the most promising candidates of Cd- or Pb-based QDs in the applications of display and lighting. However, the performances of blue InP QDs and the corresponding light emitting devices (LEDs) are far inferior to those of their red and green counterparts, which strongly limits the development of InP QD based LEDs (QLEDs) technology. Here, high quantum yield (∼81%) and large size (∼7.0 ± 0.9 nm) InP/GaP/ZnS//ZnS QDs with a thick shell have been successfully synthesized by a shell engineering approach, and the corresponding QLEDs exhibit a record brightness and external quantum efficiency of 3120 cd·m-2 and 1.01%, respectively. Large-scale density functional theory calculations on thousands-of-atoms QDs indicate that thicker-shell ones favor a more balanced carrier injection in the QD film and simultaneously suppress the FRET between closely packed QDs, which collectively contribute to the improved blue device performances.

8.
J Am Chem Soc ; 142(5): 2087-2092, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31951390

RESUMO

We describe a new electrophotocatalytic strategy that harnesses the power of light and electricity to generate an excited radical anion with a reducing potential of -3.2 V vs SCE, which can be used to activate substrates with very high reduction potentials (Ered ≈ -1.9 to -2.9 V). The resultant aryl radicals can be engaged in various synthetically useful transformations to furnish arylboronate, arylstannane, and biaryl products.

9.
Kaohsiung J Med Sci ; 36(2): 122-128, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31670477

RESUMO

Cyclophilin A (CypA), secreted from vascular smooth muscle cells and inflammatory cells in response to oxidative stress, promotes vascular atherosclerosis and development of carotid stenosis. Increased concentration of plasma CypA in acute cerebral infarction was demonstrated clinically. The primary aim of this study was to investigate the prognostic impact between CypA level and outcome in patients with acute ischemic stroke. Admission serum CypA concentrations were detected in 66 acute cerebral infarction patients and in 52 healthy individuals. Inflammatory biomarkers, including high-sensitivity C-reactive protein, adhesion molecules, interleukins, and matrix-metalloproteases, were also assessed. We also examined the relationship between plasma biomarkers, blood pressure (BP), pulse pressure, the carotid artery velocity, the prognostic assessment with modified Rankin scale, and stroke recurrence. Plasma CypA concentration was higher on the first day of hospitalization in the high BP stroke group than in normal BP stroke group, which was statistically significant, which was observed even in the third month and sixth month follow-up outpatient periods. For stroke recurrence prediction, there was an important association between the higher (>60) pulse pressure on the seventh day of hospitalization and CypA level on the third month and sixth month follow-up outpatient periods. Our study revealed higher circulating serum levels of CypA in the hypertensive stroke group than in the non-hypertensive stroke group. We expect that elevated plasma CypA level and raised pulse pressure during hospitalization to become valuable biomarkers in predicting stroke recurrence in the sixth month assessment of acute cerebral infarction.

10.
Angew Chem Int Ed Engl ; 59(1): 409-417, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31617271

RESUMO

Riboflavin-derived photocatalysts have been extensively studied in the context of alcohol oxidation. However, to date, the scope of this catalytic methodology has been limited to benzyl alcohols. In this work, mechanistic understanding of flavin-catalyzed oxidation reactions, in either the absence or presence of thiourea as a cocatalyst, was obtained. The mechanistic insights enabled development of an electrochemically driven photochemical oxidation of primary and secondary aliphatic alcohols using a pair of flavin and dialkylthiourea catalysts. Electrochemistry makes it possible to avoid using O2 and an oxidant and generating H2 O2 as a byproduct, both of which oxidatively degrade thiourea under the reaction conditions. This modification unlocks a new mechanistic pathway in which the oxidation of unactivated alcohols is achieved by thiyl radical mediated hydrogen-atom abstraction.

11.
Food Funct ; 11(1): 370-377, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31815260

RESUMO

Anti-tuberculosis (TB) drugs can induce a series of gastrointestinal adverse events, which can seriously affect patients' quality of life and may lead to treatment failure. Studies have shown that probiotics treatments can improve antibiotic-induced gastrointestinal symptoms. In this randomized, open-label, dose-response clinical trial, we investigated the preventive effects of Lactobacillus casei on anti-TB-induced gastrointestinal adverse events. In total, 429 adult patients who underwent intensive-phase anti-TB therapy were included and randomly assigned to consume one bottle of L. casei of per day (low-dose group, n = 142), two bottles of L. casei per day (high-dose group, n = 143), or no intervention (control group, n = 144) for 2 months. Each bottle of L. casei contained 10 billion colony-forming units of live L. casei. Patients' daily gastrointestinal symptoms were recorded during the intervention period. After 2 months of L. casei consumption, 397 patients had completed the intervention. Both the high and low dose L. casei groups (37.6% and 29.4%, respectively) had lower incidences of anti-TB-associated total gastrointestinal adverse events than the control group (50.0%). The high and low dose L. casei groups (3.5 d and 5.8 d, respectively) also had shorter duration anti-TB-associated adverse gastrointestinal symptoms than the control group (6.2 d). Regarding individual symptoms, the higher L. casei dose resulted in a lower incidence of vomiting and appetite loss. Similar dose-dependent protective effects of L. casei were observed regarding the duration of vomiting and appetite loss. These findings indicated that daily L. casei consumption prevented anti-TB-associated gastrointestinal adverse events. This trial was registered at the Chinese Clinical Trial Register (ChiCTR-IOR-17013210).

12.
Magn Reson Imaging ; 65: 129-135, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31644925

RESUMO

PURPOSE: To investigate the correlation between the FA parameters and Ki-67 labeling index, and their diagnostic performance in grading supratentorial non-enhancing gliomas and neuronal-glial tumors (GNGT). METHODS: This institutional review board-approved, Health Insurance Portability and Accountability (HIPAA) compliant retrospective study enrolled 35 patients, including 19 with low grade GNGT and 16 with high grade GNGT. The mean FA, maximal FA and mean maximal FA values derived from diffusion tensor imaging were measured. The correlation between the FA parameters and the Ki-67 labeling index was assessed by Spearman rank test. The receiver operating characteristic curve analysis and multivariate logistic regression analysis were performed to detect the optimal imaging parameters in grading GNGT. RESULTS: The three FA parameters of low grade GNGT were significantly lower than the high grade GNGT (p < 0.001). The mean FA, maximal FA and mean maximal FA had significant positive correlation with Ki-67 labeling index (p = 0.001, p < 0.001, p < 0.001 respectively). The maximal FA showed a higher sensitivity and specificity in grading of non-enhancing GNGT with specificity of 78.9%, sensitivity of 100.0%, respectively. CONCLUSIONS: The FA parameters correlated with Ki-67 labeling index, and were useful surrogates in preoperative grading supratentorial non-enhancing GNGT.

13.
Sci Rep ; 9(1): 18635, 2019 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-31819067

RESUMO

Disseminated tumor cells (DTCs) undergo a dormant state in the distant metastatic site(s) before becoming overt metastatic diseases. In prostate cancer (PCa), bone metastasis can occur years after prostatectomy, suggesting that bone may provide dormancy-inducing factors. To search for these factors, we prepared conditioned media (CM) from calvariae. Using live-cell imaging, we found that Calvarial-CM treatment increased cellular quiescence in C4-2B4 PCa cells. Mass spectrometry analysis of Calvarial-CM identified 132 secreted factors. Western blot and ELISA analyses confirmed the presence of several factors, including DKK3, BMP1, neogenin and vasorin in the Calvarial-CM. qRT-PCR analysis of total calvariae versus isolated osteoblasts showed that DKK3, BMP1, vasorin and neogenin are mainly expressed by osteoblasts, while MIA, LECT1, NGAL and PEDF are expressed by other calvarial cells. Recombinant human DKK3, BMP1, vasorin, neogenin, MIA and NGAL treatment increased cellular quiescence in both C4-2b and C4-2B4 PCa cells. Mechanistically, DKK3, vasorin and neogenin, but not BMP1, increased dormancy through activating the p38MAPK signaling pathway. Consistently, DKK3, vasorin and neogenin failed to induce dormancy in cells expressing dominant-negative p38αMAPK while BMP1 remained active, suggesting that BMP1 uses an alternative dormancy signaling pathway. Thus, bone secretes multiple dormancy-inducing factors that employ distinct signaling pathways to induce DTC dormancy in bone.

14.
J Mater Sci Mater Med ; 30(11): 122, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31677119

RESUMO

To reduce the long-term side effects of permanent metallic stents, a new generation of cardiovascular stents called "biodegradable stents" is being extensively developed. Zinc has been considered as a promising candidate material for biodegradable cardiovascular stents due to its excellent biocompatibility and appropriate biodegradability. However, weak mechanical properties limit its further clinic application. In this study, hot extruded pure Zn and Zn-0.02 Mg alloy were prepared. Compared with pure Zn, Zn-0.02 Mg alloy showed more homogeneous microstructure, much smaller grain size and higher mechanical strength. Zn-0.02 Mg alloy presented uniform corrosion morphologies during the immersion process, and its corrosion rates was higher than that of pure Zn. Hemocompatibility results showed that the Zn-based alloy had extremely low hemolysis rate (0.74 ± 0.15%) and strong inhibitory effect on blood coagulation, platelet adhesion and aggregation. Zn-0.02 Mg alloy also exhibited excellent cytocompatibility. Its extracts could significantly promote the proliferation of endothelial cells. Moreover, the antibacterial activities of the Zn-based alloy were demonstrated by spread plate assay, live/dead viability assay and bacterial morphology observation. These results indicate that the extruded Zn-0.02 Mg alloy has a potential in biodegradable cardiovascular stents.

15.
Aging (Albany NY) ; 11(22): 10301-10315, 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31760384

RESUMO

BACKGROUND: In this paper, we aim to explore clinical value of skeletal muscle index (SMI) and prognostic nutrition index (PNI) on resected colorectal cancer liver metastasis (CRLM). RESULTS: Among the 539 patients, 355 were males. Baseline lower SMI was associated with smaller BMI, smaller PNI, smaller pre-albumin and longer hospitalization days (P<0.05). Patients with lower SMI and PNI had significantly shorter duration of PFS and OS (P<0.05). SMI can reflect the postoperative treatment response. Postoperative 6-month's and 12-month's SMI and PNI can indicate overall prognosis. When combined SMI and PNI, prognostic AUC of ROC curves improved significantly. CONCLUSION: Combined monitor of SMI and PNI can improve the power at predicting prognosis. Postoperative 6-month's record of SMI and PNI was more accurate and predictive for CRLM prognosis. METHOD: A total of 539 resected CRLM patients between January 2013 to December 2016 with complete clinical data were included. Computed tomography image was collected from each patient. Receiver-operating characteristic (ROC) curves were constructed; area under curves (AUC) were also determined. All clinical variables were analyzed in proper way.

16.
Zhen Ci Yan Jiu ; 44(11): 840-2, 2019 Nov 25.
Artigo em Chinês | MEDLINE | ID: mdl-31777236

RESUMO

OBJECTIVE: To observe the clinical effect of "Yinqi Guiyuan" needling in the treatment of primary insomnia. METHODS: A total of 79 primary insomnia outpatients were randomly divided into treatment group (n=40) and control group (n=39). The patients in the control group were given oral Estazolam tablets once a day, for successive 4 weeks. For patients of the treatment group, Zhongwan (CV12), Xiawan (CV10), Qihai (CV6), Guanyuan (CV4), Baihui (GV20), etc., were punctured with filiform needles for 30 min. The treatment was conducted three times per week for 4 successive weeks. The sleep quality (sleeping quality, falling asleep time, sleep duration, sleep efficiency, sleep disorders, hypnotic and daytime dysfunction, 0 to 21 points) was evaluated by using Pittsburgh Sleep Quality Index (PSQI). The severity of insomnia (self-perception, sleep satisfaction, daytime function damage, sensibility change, and concern for sleep problems, 0 to 28 points) was assessed using insomnia severity index (ISI) score. The therapeutic effect was evaluated according to the PSQI score reduction rate = (pre-treatment PSQI score-post-treatment PSQI score)/pre-treatment PSQI score ×100%. RESULTS: After treatment, the total score of PSQI, ISI and the score of each item were all significantly reduced in the two groups relevant to their own pre-treatment (P<0.05). The total score, and scores of hypnotic and daytime dysfunction were significantly lower in the treatment group than in the control group (P<0.05). Of the 40 and 39 cases in the treatment and control groups, 5 (12.50%) and 4 (10.25%) were cured, 20 (50.00%) and 18 (46.15%) experienced marked improvement, 12 (30.00%) and 13 (33.33%) were effective, and 3 (7.50%) and 4 (10.25%) ineffective, with the total effective rate being 92.50% and 89.74%, respectively. No significant difference was found between the two groups in the effective rate (P>0.05). CONCLUSION: "Yinqi Guiyuan" needling and Estazolam are comparable in treatment primary insomnia, and the former is superior to the latter in avoiding hypnotic drug use and in improving daytime function.


Assuntos
Terapia por Acupuntura , Distúrbios do Início e da Manutenção do Sono , Pontos de Acupuntura , Humanos , Sono , Distúrbios do Início e da Manutenção do Sono/terapia , Resultado do Tratamento
17.
Sci Rep ; 9(1): 16567, 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31719557

RESUMO

Atrophy gastritis harbor a high risk for the development of dysplasia and gastric cancer. The study investigated the relationships of specific dietary patterns and endoscopic gastric mucosal atrophy. In this cross-sectional study, we enrolled 574 consecutive outpatients who were diagnosed as chronic gastritis according to endoscopic examination. Dietary intakes of study individuals was assessed using the semi-quantitative food group frequency questionnaire. Logistic regression analyses were used to evaluate the relationship between dietary patterns and endoscopic gastric mucosal atrophy adjusted for potential confounders. A total of 574 participants were included, 286 with endoscopic gastric mucosal atrophy. Three dietary patterns were identified by factor analysis. "Alcohol and fish" (tertile 1 vs. tertile 3: adjusted odds ratio = 1.85, 95% confidence interval: 1.06-3.22) and "coarse cereals" (tertile 1 vs. tertile 3: adjusted odds ratio = 2.05, 95% confidence interval: 1.24-3.39) were associated with an increased risk for endoscopic gastric mucosal atrophy but a "traditional" pattern was not. Dietary pattern was not associated with gastric mucosal atrophy in women or in participants with H. pylori infection. A high adherence to both "Alcohol and Fish" and "Coarse cereals" dietary patterns seem to be associated with higher odds of endoscopic gastric mucosal atrophy in men and in patients without H. pylori infection. Further prospective cohort studies needed to confirm these findings.

18.
J Org Chem ; 84(22): 14369-14380, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31647872

RESUMO

New catalytic strategies that leverage single-electron redox events have provided chemists with useful tools for solving synthetic problems. In this context, Ti offers opportunities that are complementary to late transition metals for reaction discovery. Following foundational work on epoxide reductive functionalization, recent methodological advances have significantly expanded the repertoire of Ti radical chemistry. This Synopsis summarizes recent developments in the burgeoning area of Ti radical catalysis with a focus on innovative catalytic strategies such as radical redox-relay and dual catalysis.

19.
J Exp Clin Cancer Res ; 38(1): 417, 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31623651

RESUMO

BACKGROUND: MEIS2 has been identified as one of the key transcription factors in the gene regulatory network in the development and pathogenesis of human cancers. Our study aims to identify the regulatory mechanisms of MEIS2 in hepatocellular carcinoma (HCC), which could be targeted to develop new therapeutic strategies. METHODS: The variation of MEIS2 levels were assayed in a cohort of HCC patients. The proliferation, clone-formation, migration, and invasion abilities of HCC cells were measured to analyze the effects of MEIS2C and MEIS2D (MEIS2C/D) knockdown with small hairpin RNAs in vitro and in vivo. Chromatin immunoprecipitation (ChIP) was performed to identify MEIS2 binding site. Immunoprecipitation and immunofluorescence assays were employed to detect proteins regulated by MEIS2. RESULTS: The expression of MEIS2C/D was increased in the HCC specimens when compared with the adjacent noncancerous liver (ANL) tissues. Moreover, MEIS2C/D expression negatively correlated with the prognosis of HCC patients. On the other hand, knockdown of MEIS2C/D could inhibit proliferation and diminish migration and invasion of hepatoma cells in vitro and in vivo. Mechanistically, MESI2C activated Wnt/ß-catenin pathway in cooperation with Parafibromin (CDC73), while MEIS2D suppressed Hippo pathway by promoting YAP nuclear translocation via miR-1307-3p/LATS1 axis. Notably, CDC73 could directly either interact with MEIS2C/ß-catenin or MEIS2D/YAP complex, depending on its tyrosine-phosphorylation status. CONCLUSIONS: Our studies indicate that MEISC/D promote HCC development via Wnt/ß-catenin and Hippo/YAP signaling pathways, highlighting the complex molecular network of MEIS2C/D in HCC pathogenesis. These results suggest that MEISC/D may serve as a potential novel therapeutic target for HCC.


Assuntos
Carcinoma Hepatocelular/patologia , Proteínas de Ciclo Celular/metabolismo , Regulação Neoplásica da Expressão Gênica , Proteínas de Homeodomínio/metabolismo , Neoplasias Hepáticas/patologia , Proteínas Serina-Treonina Quinases/metabolismo , Fatores de Transcrição/metabolismo , Via de Sinalização Wnt , Adulto , Idoso , Animais , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Progressão da Doença , Feminino , Proteínas de Homeodomínio/genética , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Masculino , Camundongos , Camundongos Nus , MicroRNAs/genética , Pessoa de Meia-Idade , Metástase Neoplásica , Fatores de Transcrição/genética , Células Tumorais Cultivadas , Proteínas Supressoras de Tumor/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
20.
Research (Wash D C) ; 2019: 2602414, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31549053

RESUMO

4-Hydroxyphenylpyruvate dioxygenase (HPPD) is a promising target for drug and pesticide discovery. The unknown binding mode of substrate is still a big challenge for the understanding of enzymatic reaction mechanism and novel HPPD inhibitor design. Herein, we determined the first crystal structure of Arabidopsis thaliana HPPD (AtHPPD) in complex with its natural substrate (HPPA) at a resolution of 2.80 Å. Then, combination of hybrid quantum mechanics/molecular mechanics (QM/MM) calculations confirmed that HPPA takes keto rather than enol form inside the HPPD active pocket. Subsequent site-directed mutagenesis and kinetic analysis further showed that residues (Phe424, Asn423, Glu394, Gln307, Asn282, and Ser267) played important roles in substrate binding and catalytic cycle. Structural comparison between HPPA-AtHPPD and holo-AtHPPD revealed that Gln293 underwent a remarkable rotation upon the HPPA binding and formed H-bond network of Ser267-Asn282-Gln307-Gln293, resulting in the transformation of HPPD from an inactive state to active state. Finally, taking the conformation change of Gln293 as a target, we proposed a new strategy of blocking the transformation of HPPD from inactive state to active state to design a novel inhibitor with K i value of 24.10 nM towards AtHPPD. The inhibitor has entered into industry development as the first selective herbicide used for the weed control in sorghum field. The crystal structure of AtHPPD in complex with the inhibitor (2.40 Å) confirmed the rationality of the design strategy. We believe that the present work provides a new starting point for the understanding of enzymatic reaction mechanism and the design of next generation HPPD inhibitors.

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