Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
Mais filtros











Intervalo de ano de publicação
1.
Adv Mater ; : e2408094, 2024 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-39096074

RESUMO

Multinuclear metal clusters are ideal candidates to catalyze small molecule activation reactions involving the transfer of multiple electrons. However, synthesizing active metal clusters is a big challenge. Herein, on constructing an unparalleled Co4(SO4)4 cluster within porphyrin-based metal-organic frameworks (MOFs) and the electrocatalytic features of such Co4(SO4)4 clusters for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is reported. The reaction of CoII sulfate and metal complexes of tetrakis(4-pyridyl)porphyrin under solvothermal conditions afforded Co4-M-MOFs (M═Co, Cu, and Zn). Crystallographic studies revealed that these Co4-M-MOFs have the same framework structure, having the Co4(SO4)4 clusters connected by metalloporphyrin units through Co─Npyridyl bonds. In the Co4(SO4)4 cluster, the four CoII ions are chemically and symmetrically equivalent and are each coordinated with four sulfate O atoms to give a distorted cube-like structure. Electrocatalytic studies showed that these Co4-M-MOFs are all active for electrocatalytic OER and ORR. Importantly, by regulating the activity of the metalloporphyrin units, it is confirmed that the Co4(SO4)4 cluster is active for oxygen electrocatalysis. With the use of Co porphyrins as connecting units, Co4-Co-MOF displays the highest electrocatalytic activity in this series of MOFs by showing a 10 mA cm-2 OER current density at 357 mV overpotential and an ORR half-wave potential at 0.83 V versus reversible hydrogen electrode (RHE). Theoretical studies revealed the synergistic effect of two proximal Co atoms in the Co4(SO4)4 cluster in OER by facilitating the formation of O─O bonds. This work is of fundamental significance to present the construction of Co4(SO4)4 clusters in framework structures for oxygen electrocatalysis and to demonstrate the cooperation between two proximal Co atoms in such clusters during the O─O bond formation process.

2.
Zhongguo Gu Shang ; 37(8): 818-23, 2024 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-39183008

RESUMO

OBJECTIVE: To observe the clinical efficacy of meridian massage in the treatment of cervical spondylotic radiculopathy. METHODS: Sixty-four patients with cervical radiculopathy treated from March 2020 to June 2023 were divided into the observation group and the treatment group, with 32 cases in each group. The observation group received conventional treatment, including 14 males and 18 females with an average age of (41.34±7.23) years old ranging from 32 to 55 years old;the disease duration ranged from 9 to 17 months with an average of (14.23±3.56) months;C5 and C6 nerve root compression occurred in 12 cases, C7 nerve root compression occurred in 17 cases, C8 nerve root compression occurred in 3 cases. The treatment group received massage therapy on the basis of conventional treatment, including 17 males and 15 females with an average age of (40.86±6.97) years old ranging from 30 to 54 years old;the disease duration ranged from 8 to 18 months with an average of (15.43±3.48) months;C5 and C6 nerve root compression occurred in 14 cases, C7 nerve root compression occurred in 16 cases, C8 nerve root compression occurred in 2 cases. The clinical efficacy was evaluated by visual analogue scale(VAS), neck disability index(NDI) and clinical assessment scale for cervical spondylosis(CASCS) before and after 2-week treatment, and the range of motion of cervical spine was compared before and after treatment. RESULTS: After 2-week treatment, the VAS and NDI scores of the treatment group and the observation group decreased, while the CASCS scores increased(P<0.001). After 2-week treatment, the VAS and NDI scores were lower and the CASCS scores were higher in the treatment group than those of the observation group(P<0.001). Comparing with those before treatment, the range of motion of flexion, extension, left flexion, right flexion, left rotation and right rotation after 2-week treatment increased in two groups(P<0.05). Comparing with the observation group, the range of motion of flexion, extension, left flexion, right flexion, left rotation and right rotation increased more significantly in the treatment group(P<0.05). CONCLUSION: Meridian massage is effective in the treatment of cervical Spondylotic radiculopathy, which can effectively relieve neck pain, improve clinical symptoms and improve patient satisfaction.


Assuntos
Massagem , Radiculopatia , Espondilose , Humanos , Feminino , Masculino , Radiculopatia/terapia , Pessoa de Meia-Idade , Adulto , Espondilose/terapia , Massagem/métodos , Meridianos , Vértebras Cervicais , Resultado do Tratamento
3.
Angew Chem Int Ed Engl ; 63(36): e202409793, 2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-38923266

RESUMO

Due to the challenge of cleaving O-O bonds at single Co sites, mononuclear Co complexes typically show poor selectivity for the four-electron (4e-) oxygen reduction reaction (ORR). Herein, we report on selective 4e- ORR catalyzed by a Co porphyrin with a hanged ZnII ion. Inspired by Cu/Zn-superoxide dismutase, we designed and synthesized 1-CoZn with a hanging ZnII at the second sphere of a Co porphyrin. Complex 1-CoZn is much more effective than its Zn-lacking analogues to catalyze the 4e- ORR in neutral aqueous solutions, giving an electron number of 3.91 per O2 reduction. With spectroscopic studies, the hanging ZnII was demonstrated to be able to facilitate the electron transfer from CoII to O2, through an electronic "pull effect", to give CoIII-superoxo. Theoretical studies further suggested that this "pull effect" plays crucial roles in assisting O-O bond cleavage. This work is significant to present a new strategy of hanging a ZnII to improve O2 activation and O-O bond cleavage.

4.
J Neuroendocrinol ; 36(4): e13381, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38468159

RESUMO

Hematological indicators of chronic systemic inflammation are significant biomarkers for gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs). We performed a systematic review and meta-analysis to assess the impact of certain factors on the overall survival (OS), progression-free survival (PFS), and disease-free survival (DFS) of patients with GEP-NENs. These factors include the neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), lymphocyte/monocyte ratio (LMR), and C-reactive protein (CRP) levels. After searching the Medline, Embase, and Cochrane Library databases from January 1, 2000 to October 20, 2022 and the American Society of Clinical Oncology conference proceedings from January 1, 2017, hazard ratios (HRs) and 95% confidence intervals (CIs) were extracted. Subgroup analyses were conducted to identify the origins of heterogeneity and examine the impact of factor grouping. The effects of the cut-off values and sample size were assessed by meta-regression. The results revealed that higher NLRs, PLRs, and CRP levels were associated with shorter OS (HR = 2.09, 95% CI = 1.55-2.8; HR = 1.79, 95% CI = 1.40-2.28; and HR = 2.88, 95% CI = 2.09-3.95, respectively; all p < 0.001). Higher NLRs and lower LMRs were associated with shorter DFS (HR = 3.34, 95% CI = 2.11-5.29 and HR = 2.71, 95% CI = 2.27-3.24, respectively; both p < 0.001). Higher PLRs and CRP levels were correlated with shorter PFS (HR = 3.48, 95% CI = 1.34-9.03, p = 0.01 and HR = 3.14, 95% CI = 1.63-6.08, p = 0.001). As demonstrated in the research, hematological indicators of systemic inflammation are promising biomarkers for GEP-NEN assessment.


Assuntos
Linfócitos , Tumores Neuroendócrinos , Humanos , Prognóstico , Biomarcadores/metabolismo , Linfócitos/metabolismo , Inflamação/metabolismo , Tumores Neuroendócrinos/diagnóstico , Tumores Neuroendócrinos/metabolismo
5.
J Integr Plant Biol ; 66(2): 166-168, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38294100

RESUMO

The Ti-TAN TurboID plasmid toolbox enables proximity labeling applications in transient assays in Nicotiana benthamiana in a fast and cost-efficient manner, making TurboID-based proximity labeling broadly accessible to plant scientists.


Assuntos
Nicotiana , Titânio , Nicotiana/genética , Plantas , Plasmídeos/genética
6.
Angew Chem Int Ed Engl ; 63(7): e202313034, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38097503

RESUMO

Oxygen reduction reaction (ORR) is of critical significance in the advancement of fuel cells and zinc-air batteries. The iron-nitrogen (Fe-Nx ) sites exhibited exceptional reactivity towards ORR. However, the task of designing and controlling the local structure of Fe species for high ORR activity and stability remains a challenge. Herein, we have achieved successful immobilization of Fe species onto the highly curved surface of S, N co-doped carbonaceous nanosprings (denoted as FeNS/Fe3 C@CNS). The induction of this twisted configuration within FeNS/Fe3 C@CNS arose from the assembly of chiral templates. For electrocatalytic ORR tests, FeNS/Fe3 C@CNS exhibits a half-wave potential (E1/2 ) of 0.91 V in alkaline medium and a E1/2 of 0.78 V in acidic medium. The Fe single atoms and Fe3 C nanoparticles are coexistent and play as active centers within FeNS/Fe3 C@CNS. The highly curved surface, coupled with S substitution in the coordination layer, served to reduce the energy barrier for ORR, thereby enhancing the intrinsic catalytic activity of the Fe single-atom sites. We also assembled a wearable flexible Zn-air battery using FeNS/Fe3 C@CNS as electrocatalysts. This work provides new insights into the construction of highly curved surfaces within carbon materials, offering high electrocatalytic efficacy and remarkable performance for flexible energy conversion devices.

7.
BMC Gastroenterol ; 23(1): 440, 2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-38097952

RESUMO

BACKGROUND: Type 1 gastric neuroendocrine tumors (NETs) are relatively rare to the extent that some physicians have little experience in diagnosing and treating them. The purpose of this study was to increase the understanding of the disease by analyzing and summarizing the management and prognoses of patients with type 1 gastric NETs at our center. METHODS: The data of 229 patients (59.4% female) with type 1 gastric NETs who were treated at our center during 2011-2022 were retrospectively analyzed. RESULTS: The average patient age was 50.5 ± 10.8 years. Multiple tumors affected 72.5% of the patients; 66.4% of the tumors were < 1 cm, 69.4% were NET G1, and 2.2% were stage III-IV. A total of 76.9% of the patients had received endoscopic management, 60.7% had received traditional Chinese medicine treatment, 10.5% received somatostatin analogues treatment, and 6.6% underwent surgical resection. Seventy patients (41.2%) experienced the first recurrence after a median follow-up of 31 months (range: 2-122 months), and the median recurrence-free time was 43 months. The 1-, 2-, and 3-year cumulative recurrence-free survival rates were 71.8%, 56.8%, and 50.3%, respectively. During a median follow-up of 39 months (range: 2-132 months), one patient had bilateral pulmonary metastasis, and no disease-related deaths were observed. CONCLUSION: Type 1 gastric NETs have a high recurrence rate and a long disease course, underscoring the importance of long-term and comprehensive management.


Assuntos
Tumores Neuroendócrinos , Neoplasias Gástricas , Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Masculino , Tumores Neuroendócrinos/diagnóstico , Tumores Neuroendócrinos/terapia , Tumores Neuroendócrinos/patologia , Estudos Retrospectivos , Prognóstico , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/terapia
8.
Zhongguo Gu Shang ; 36(9): 859-65, 2023 Sep 25.
Artigo em Chinês | MEDLINE | ID: mdl-37735079

RESUMO

OBJECTIVE: To investigate the clinical effect of "Tianji" orthopedic robot-assisted percutaneous vertebro plasty(PVP) surgery in the treatment of upper thoracic osteoporotic fracture. METHODS: A retrospective analysis was performed on 32 patients with upper thoracic osteoporotic fracture who underwent PVP surgery in Shenzhen Hospital of Traditional Chinese Medicine from August 2016 to June 2022. There were 8 males and 24 females, ranging in age from 58 to 90 years old, with a mean of (67.75±12.27) years old. Fifteen patients were treated with robot-assisted PVP surgery (robot group), including 3 males and 12 females, with an average age of (68.5±10.3) years. Fracture location:1 case of T2 fracture, 1 case of T3 fracture, 3 cases of T4 fracture, 3 cases of T5 fracture, and 7 cases of T6 fracture. The follow-up period ranged from 1.0 to 3.0 months, with a mean of (1.6±0.7) months. Seventeen patients underwent routine PVP surgery (conventional group), including 5 males and 12 females, with an average age of (66.8±11.6) years old. Fracture location:1 case of T1 fracture, 5 cases of T4 fracture, 2 cases of T5 fracture and 9 cases of T6 fracture. The follow-up period ranged from 0.5 to 4.0 months, with a mean of (1.5±0.6) months. Preoperative and postoperative visual analogue scale(VAS) and Oswestry disability index(ODI) scores were compared between the two groups, and the number of punctures, perspective times, operation time, intraoperative blood loss, bone cement distribution, bone cement leakage, and intraoperative radiation dose were compared between the two groups. RESULTS: Number of punctures times, perspective times, operation time, intraoperative blood loss, bone cement distribution, bone cement leakage and intraoperative radiation dose in the robot group were all significantly better than those in the conventional group(P<0.05). VAS of 2.03±0.05 and ODI of (22.16±4.03) % in the robot group were significantly better than those of the robot group before surgery, which were (8.67±0.25) score and (79.40±7.72)%(t=100.869, P<0.001;t=25.456, P<0.001). VAS of 2.17±0.13 and ODI of (23.88±6.15)% in the conventional group were significantly better than those before surgery, which were (8.73±0.18) score and (80.01±7.59)%(t=121.816, P<0.001;t=23.691, P<0.001). There was no significant difference in VAS and ODI between the two groups after operation (t=-3.917, P=0.476;t=-0.922, P=0.364). CONCLUSION: Robot-assisted PVP in the treatment of upper thoracic osteoporotic fractures can further improve surgical safety, reduce bone cement leakage, and achieve satisfactory clinical efficacy.


Assuntos
Fraturas por Osteoporose , Robótica , Feminino , Masculino , Humanos , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Fraturas por Osteoporose/cirurgia , Perda Sanguínea Cirúrgica , Cimentos Ósseos , Estudos Retrospectivos , Vértebras Torácicas/cirurgia
9.
Adv Mater ; 35(42): e2305659, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37620729

RESUMO

Oxygen evolution reaction (OER) plays a key role in proton exchange membrane water electrolysis (PEMWE), yet the electrocatalysts still suffer from the disadvantages of low activity and poor stability in acidic conditions. Here, a new class of CdRu2 IrOx nanoframes with distorted structure for acidic OER is successfully fabricated. Impressively, CdRu2 IrOx displays an ultralow overpotential of 189 mV and an ultralong stability of 1500 h at 10 mA cm⁻2 toward OER in 0.5 M H2 SO4 . Moreover, a PEMWE using the distorted CdRu2 IrOx can be steadily operated at 0.1 A cm⁻2 for 90 h. Microstructural analyses and X-ray absorption spectroscopy (XAS) demonstrate that the synergy between Ru and Ir in CdRu2 IrOx induces the distortion of Ru-O, Ir-O, and Ru-M (M = Ru, Ir) bonds. In situ XAS indicates that the applied potential leads to the deformation octahedral structure of RuOx /IrOx and the formation of stable Ru5+ species for OER. Theoretical calculations also reveal that the distorted structures can reduce the energy barrier of rate-limiting step during OER. This work provides an efficient strategy for constructing structural distortion to achieve significant enhancement on the activity and stability of OER catalysts.

10.
Nanomaterials (Basel) ; 13(7)2023 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-37049334

RESUMO

Exploiting cost-effective and durable non-platinum electrocatalysts for oxygen reduction reaction (ORR) is of great significance for the development of abundant renewable energy conversion and storage technologies. Herein, a series of Co3O4 supported on graphene-like carbon (Co3O4/C) samples were firstly effectively synthesized by one-step calcination of cobalt phthalocyanine and their electrocatalytic performances were measured for ORR under an alkaline medium. By systematically adjusting the calcination temperature of cobalt phthalocyanine, we found that the material pyrolyzed at 750 °C (Co3O4/C-750) shows the best ORR electrocatalytic performance (half-wave potentials of 0.77 V (vs. RHE) in 0.1 M KOH) among all the control samples. Moreover, it displays better stability and superior methanol tolerance than commercial 20% Pt/C. The further electrochemical test results reveal that the process is close in characteristics to the four-electron ORR process on Co3O4/C-750. In addition, Co3O4/C-750 applied in the zinc-air battery presents 1.34 V of open circuit potential. Based on all the characterizations, the enhanced electrocatalytic performances of Co3O4/C-750 composite should be ascribed to the synergistic effect between Co3O4 and the graphene-like carbon layer structure produced by pyrolysis of cobalt phthalocyanine, as well as its high specific surface area.

11.
PLoS Pathog ; 18(10): e1010909, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36256684

RESUMO

Viruses manipulate the cells they infect in order to replicate and spread. Due to strict size restrictions, viral genomes have reduced genetic space; how the action of the limited number of viral proteins results in the cell reprogramming observed during the infection is a long-standing question. Here, we explore the hypothesis that combinatorial interactions may expand the functional landscape of the viral proteome. We show that the proteins encoded by a plant-infecting DNA virus, the geminivirus tomato yellow leaf curl virus (TYLCV), physically associate with one another in an intricate network, as detected by a number of protein-protein interaction techniques. Importantly, our results indicate that intra-viral protein-protein interactions can modify the subcellular localization of the proteins involved. Using one particular pairwise interaction, that between the virus-encoded C2 and CP proteins, as proof-of-concept, we demonstrate that the combination of viral proteins leads to novel transcriptional effects on the host cell. Taken together, our results underscore the importance of studying viral protein function in the context of the infection. We propose a model in which viral proteins might have evolved to extensively interact with other elements within the viral proteome, enlarging the potential functional landscape available to the pathogen.


Assuntos
Begomovirus , Vírus de Plantas , Solanum lycopersicum , Proteínas Virais/genética , Proteínas Virais/metabolismo , Proteoma/metabolismo , Doenças das Plantas , Begomovirus/metabolismo , Vírus de Plantas/metabolismo
12.
World J Gastroenterol ; 28(20): 2163-2175, 2022 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-35721885

RESUMO

Pancreatic neuroendocrine neoplasms (PanNENs) are rare neoplasms with strong heterogeneity that have experienced an increasing incidence rate in recent years. For patients with locally advanced or distant metastatic PanNENs, systemic treatment options vary due to the different differentiations, grades and stages. The available options for systemic therapy include somatostatin analogs, mole-cularly targeted agents, cytotoxic chemotherapeutic agents, immune checkpoint inhibitors, and peptide receptor radionuclide therapy. In addition, the development of novel molecularly targeted agents is currently in progress. The sequence of selection between different chemotherapy regimens has been of great interest, and resistance to chemotherapeutic agents is the major limitation in their clinical application. Novel agents and high-level clinical evidence continue to emerge in the field of antiangiogenic agents. Peptide receptor radionuclide therapy is increasingly employed for the treatment of advanced neuroendocrine tumors, and greater therapeutic efficacy may be achieved by emerging radio-labeled peptides. Since immune checkpoint inhibitor monotherapies for PanNENs appear to have limited antitumor activity, dual immune checkpoint inhibitor therapies or combinations of antiangiogenic therapies and immune checkpoint inhibitors have been applied in the clinic to improve clinical efficacy. Combining the use of a variety of agents with different mechanisms of action provides new possibilities for clinical treatments. In the future, the study of systemic therapies will continue to focus on the screening of the optimal benefit population and the selection of the best treatment sequence strategy with the aim of truly achieving individualized precise treatment of PanNENs.


Assuntos
Antineoplásicos , Tumores Neuroendócrinos , Neoplasias Pancreáticas , Inibidores da Angiogênese/uso terapêutico , Antineoplásicos/uso terapêutico , Humanos , Inibidores de Checkpoint Imunológico , Tumores Neuroendócrinos/tratamento farmacológico , Tumores Neuroendócrinos/patologia , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Radioisótopos/uso terapêutico , Receptores de Peptídeos , Somatostatina
13.
Methods Mol Biol ; 2382: 115-127, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34705236

RESUMO

The availability of a fast and controlled mitotic model system that could simplify the generation of genetic material and reduce the experimental time from months to days would largely benefit research in plant cell division. In this protocol, we propose the use of pavement cells of Nicotiana benthamiana leaves to study cell division, which is artificially induced by Agrobacterium-mediated transient overexpression of the transcription factor E2Fb. The cell division-inducing overexpression of E2Fb can be combined with the expression of fluorescent protein-tagged proteins of interest or with dyes, which could be visualized throughout the cell cycle under the microscope. This simple and affordable method enables the study of cell cycle regulation and cell division in plants, from genome replication to cell wall formation, in a fast and controlled manner, and can be used for functional studies when coupled with chemical inhibitors or reverse genetic approaches.


Assuntos
Nicotiana , Agrobacterium/genética , Agrobacterium tumefaciens/genética , Divisão Celular , Fatores de Transcrição E2F , Folhas de Planta/genética , Plantas Geneticamente Modificadas/genética , Nicotiana/genética
14.
World J Clin Cases ; 9(24): 7146-7153, 2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34540971

RESUMO

BACKGROUND: Neuroendocrine carcinoma of the breast (NECB) is a rare type of malignant tumor. Due to the rarity of NECB, the relevant literature mostly comprises case reports. Available data on treatment options for NECB are very limited. CASE SUMMARY: A 62-year-old woman presented to our hospital in October 2016 for intermittent vomiting and diarrhea and masses in the liver found on abdominal computed tomography (CT) imaging. She was diagnosed in July 2012 with neuroendocrine carcinoma of the right breast in local hospital. The patient initially presented with a painful lesion of the right breast. She then undergone surgical resection and adjuvant chemotherapy with pirarubicin and paclitaxel for four cycles as well as endocrine therapy. She was regularly followed every 3 mo after surgery. Enhanced abdominal CT imaging at our hospital revealed multiple suspicious masses in the liver with the largest lesion measuring 8.4 cm × 6.3 cm. Chest CT revealed masses in the anterior chest wall and lung. Core needle biopsy of the lesion revealed liver metastases of NECB. A bone scan showed right second anterior rib metastases. Upper endoscopy and colonoscopy did not provide any evidence of another possible primary tumor. She stopped receiving endocrine therapy and then received etoposide and cisplatin (EP) chemotherapy as a first-line treatment regimen for six cycles at our hospital after liver, bone, and lung metastases. On October 2017, the chemotherapy regimen was changed to S-1 (40 mg twice daily, days 1-14) combined with temozolomide (200 mg once daily, days 10-14) (STEM) every 21 d as a second-line treatment regimen due to disease progression. Progression-free survival (PFS) and adverse effects after treatment were analyzed, and the efficacy of the STEM regimen was assessed using RECIST version 1.1. This patient achieved a partial response after using the STEM regimen, with a PFS of 23 mo. Adverse effects included only grade 1 digestive tract reactions with no need for a reduction in chemotherapy. CONCLUSION: This case report suggests that the STEM regimen may be effective and well tolerated as the second-line treatment for advanced NECB. STEM is still highly effective in patients who show disease progression with the EP regimen. More evidence is needed to prove the validity of STEM.

15.
Nat Commun ; 12(1): 4278, 2021 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-34257307

RESUMO

Geminiviruses are plant viruses with limited coding capacity. Geminivirus-encoded proteins are traditionally identified by applying a 10-kDa arbitrary threshold; however, it is increasingly clear that small proteins play relevant roles in biological systems, which calls for the reconsideration of this criterion. Here, we show that geminiviral genomes contain additional ORFs. Using tomato yellow leaf curl virus, we demonstrate that some of these small ORFs are expressed during the infection, and that the encoded proteins display specific subcellular localizations. We prove that the largest of these additional ORFs, which we name V3, is required for full viral infection, and that the V3 protein localizes in the Golgi apparatus and functions as an RNA silencing suppressor. These results imply that the repertoire of geminiviral proteins can be expanded, and that getting a comprehensive overview of the molecular plant-geminivirus interactions will require the detailed study of small ORFs so far neglected.


Assuntos
Begomovirus/patogenicidade , Geminiviridae/genética , Geminiviridae/patogenicidade , Genoma Viral/genética , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/fisiologia , Fases de Leitura Aberta/genética , Doenças das Plantas/virologia , Interferência de RNA/fisiologia , Nicotiana/ultraestrutura , Proteínas Virais/genética , Proteínas Virais/metabolismo , Virulência
16.
World J Gastroenterol ; 27(21): 2895-2909, 2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34135560

RESUMO

BACKGROUND: Poorly differentiated gastric neuroendocrine neoplasms (PDGNENs) include gastric neuroendocrine carcinoma (NEC) and mixed adenoneuroendocrine carcinoma, which are highly malignant and rare tumors, and their incidence has increased over the past few decades. However, the clinicopathological features and outcomes of patients with PDGNENs have not been completely elucidated. AIM: To investigate the clinicopathological characteristics and prognostic factors of patients with PDGNENs. METHODS: The data from seven centers in China from March 2007 to November 2019 were analyzed retrospectively. RESULTS: Among the 232 patients with PDGNENs, 191 (82.3%) were male, with an average age of 62.83 ± 9.11 years. One hundred and thirteen (49.34%) of 229 patients had a stage III disease and 86 (37.55%) had stage IV disease. Three (1.58%) of 190 patients had no clinical symptoms, while 187 (98.42%) patients presented clinical symptoms. The tumors were mainly (89.17%) solitary and located in the upper third of the stomach (cardia and fundus of stomach: 115/215, 53.49%). Most lesions were ulcers (157/232, 67.67%), with an average diameter of 4.66 ± 2.77 cm. In terms of tumor invasion, the majority of tumors invaded the serosa (116/198, 58.58%). The median survival time of the 232 patients was 13.50 mo (7, 31 mo), and the overall 1-year, 3-year, and 5-year survival rates were 49%, 19%, and 5%, respectively. According to univariate analysis, tumor number, tumor diameter, gastric invasion status, American Joint Committee on Cancer (AJCC) stage, and distant metastasis status were prognostic factors for patients with PDGNENs. Multivariate analysis showed that tumor number, tumor diameter, AJCC stage, and distant metastasis status were independent prognostic factors for patients with PDGNENs. CONCLUSION: The overall prognosis of patients with PDGNENs is poor. The outcomes of patients with a tumor diameter > 5 cm, multiple tumors, and stage IV tumors are worse than those of other patients.


Assuntos
Tumores Neuroendócrinos , Neoplasias Gástricas , Idoso , China/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Tumores Neuroendócrinos/patologia , Prognóstico , Estudos Retrospectivos , Neoplasias Gástricas/epidemiologia , Neoplasias Gástricas/patologia
17.
Nat Commun ; 12(1): 2780, 2021 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-33986276

RESUMO

Geminiviruses are causal agents of devastating diseases in crops. Geminiviruses have circular single-stranded (ss) DNA genomes that are replicated in the nucleus of the infected plant cell through double-stranded (ds) DNA intermediates by the plant DNA replication machinery. Which host DNA polymerase mediates geminiviral multiplication, however, has so far remained elusive. Here, we show that subunits of the nuclear replicative DNA polymerases α and δ physically interact with the geminivirus-encoded replication enhancer protein, C3, and that these polymerases are required for viral replication. Our results suggest that, while DNA polymerase α is essential to generate the viral dsDNA intermediate, DNA polymerase δ mediates the synthesis of new copies of the geminiviral ssDNA genome, and that the virus-encoded C3 may act selectively, recruiting DNA polymerase δ over ε to favour productive replication.


Assuntos
DNA Polimerase III/metabolismo , DNA Polimerase I/metabolismo , Replicação do DNA/genética , DNA Viral/biossíntese , Geminiviridae/genética , Replicação Viral/genética , Genoma Viral/genética , Plantas/virologia , Subunidades Proteicas/metabolismo , Proteínas Virais/metabolismo
18.
BMC Gastroenterol ; 21(1): 188, 2021 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-33892648

RESUMO

BACKGROUND: Currently, there are no circulating diagnostic biomarkers for gastric neuroendocrine neoplasms (g-NENs). In previous studies, we found that miRNA-202-3p is overexpressed in the tumour tissue of type 1 g-NEN. We speculated that miRNA-202-3p is also likely to be highly expressed in circulating blood. METHODS: A total of 27 patients with type 1 g-NEN and 27 age- and sex-matched control participants were enrolled in this study. The miRNA-202-3p levels in serum obtained from the participants were measured by qRT-PCR. The expression level of miRNA-202-3p in the samples was calculated by comparison with a standard curve. RESULTS: The clinical characteristics of the patients were similar to those of the patient samples in previous reports. Expression of miRNA-202-3p was significantly higher in the patient group (3.84 × 107 copies/nl) than in the control group (0.635 × 107 copies/nl). The area under the ROC curve (AUC) was 0.878 (95% CI: 0.788-0.968), and the optimal cut-off point was approximately 1.12 × 107 copies/nl. The sensitivity and specificity were 88.9% and 77.8%, respectively. CONCLUSION: This study suggests that miRNA-202-3p is potentially useful as a biomarker of type 1 g-NEN; further investigation and verification should be performed in future research.


Assuntos
MicroRNAs/sangue , Tumores Neuroendócrinos , Neoplasias Gástricas , Biomarcadores , Biomarcadores Tumorais/genética , Perfilação da Expressão Gênica , Humanos , Tumores Neuroendócrinos/diagnóstico , Tumores Neuroendócrinos/genética , Curva ROC , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/genética
19.
Neuroendocrinology ; 111(8): 752-763, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32668427

RESUMO

OBJECTIVE: The efficacy of the capecitabine/temozolomide (CAPTEM) regimen has been demonstrated in metastatic neuroendocrine neoplasms (NENs), but because of varying response rates among the patients, biomarkers to predict its response are greatly needed. Here, we investigated the clinical utility of a Ki-67 index to predict the CAPTEM regimen objective responses and select patients who could benefit from this regimen. METHODS: Metastatic NENs patients treated with the CAPTEM regimen from 4 high-volume medical centers were selected and grouped in a training and validation cohort. The classification and regression tree (CART) was generated to identify the optimal threshold of Ki-67 for stratifying the patients into different Ki-67 range groups based on their response to the CAPTEM regimen. RESULTS AND CONCLUSIONS: The overall response rate (ORR) and disease control rate of the entire cohort (N = 151) were 26.5 and 76.2%, respectively, with a median progression-free survival (PFS) of 12.0 months. CART analysis showed that patients in the Ki-67 range group 10-40% demonstrated a significantly higher ORR than those in Ki-67 >40 and <10% groups (p < 0.001 in the training cohort and p = 0.036 in the validation cohort). Response to the CAPTEM regimen was not influenced by the expression of O6-methylguanine-DNA methyltransferase or primary tumor location. Multivariate analysis identified the Ki-67 index as the only independent prognostic factor for overall survival (p = 0.031) and PFS (p = 0.006). The proposed Ki-67 index was externally validated and could be used to clinically identify suitable metastatic NENs patients who could achieve an optimal cytoreduction using the CAPTEM regimen.


Assuntos
Antineoplásicos/farmacologia , Capecitabina/farmacologia , Antígeno Ki-67/sangue , Tumores Neuroendócrinos/tratamento farmacológico , Avaliação de Resultados em Cuidados de Saúde , Temozolomida/farmacologia , Adolescente , Adulto , Idoso , Quimioterapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tumores Neuroendócrinos/sangue , Prognóstico , Estudos Retrospectivos , Adulto Jovem
20.
World J Gastrointest Oncol ; 12(12): 1416-1427, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33362912

RESUMO

BACKGROUND: For the rarity of type 3 gastric neuroendocrine tumours (g-NETs), their clinicopathological characteristics and prognosis are not well illustrated. AIM: To describe the clinicopathological features and outcome of type 3 g-NETs in the Chinese population. METHODS: Based on the 2019 WHO pathological classification, the clinicopathological characteristics and prognosis of patients with type 3 g-NETs in China were retrospectively analysed. RESULTS: A total of 77 patients (55.8% of females) with type 3 g-NETs were analysed, with a median age of 48 years (range: 28-79 years). The tumours were mainly located in the gastric fundus/body (83.1%) and were mostly solitary (83.1%), with a median size of 1.5 cm (0.8-3.5 cm). Of these, there were 37 G1 tumours (48.1%), 31 G2 (40.3%), and 9 G3 (11.7%). Ten (13.0%) and 24 (31.2%) patients had lymph node and distant metastasis, respectively. In addition, type 3 g-NETs were heterogeneous. Compared with G1 NETs, G2 NETs had a higher lymph node metastasis rate, and G3 NETs had a higher distant metastasis rate. G1 and G2 NETs with stage I/II disease (33/68) received endoscopic treatment, and no tumour recurrence or tumour-related death was observed within a median follow-up time of 36 mo. Grade and distant metastasis were identified to be independent risk factors for prognosis in multivariable analysis. CONCLUSION: Type 3 g-NETs are obviously heterogeneous, and the updated WHO 2019 pathological classification may be used to effectively evaluate their biological behaviors and prognosis. Also, endoscopic treatment should be considered for small (< 2 cm), low grade, superficial tumours.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA