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1.
Am J Gastroenterol ; 119(4): 700-711, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37929952

RESUMO

INTRODUCTION: Portal hypertension progression can be relieved after controlling the etiology of liver cirrhosis. Whether beta-blockers could additionally enhance the effects during treatment, particularly for small esophageal varices (EV), was unclear. This study aims to assess the efficacy of add-on carvedilol to delay EV progression during anti-hepatitis B virus (HBV) treatment in HBV-related cirrhosis. METHODS: This randomized controlled trial enrolled patients with virologically suppressed HBV-compensated cirrhosis and small/medium EV. The participants were randomly assigned to receive nucleos(t)ide analog (NUC) or carvedilol 12.5 mg plus NUC (1:1 allocation ratio). The primary end point was the progression rate of EV at 2 years of follow-up. RESULTS: A total of 238 patients (small EV, 77.3%) were randomized into 119 NUC and 119 carvedilol plus NUC (carvedilol [CARV] combination group). Among them, 205 patients (86.1%) completed paired endoscopies. EV progression rate was 15.5% (16/103) in the NUC group and 12.7% (13/102) in the CARV combination group (relative risk = 0.79, 95% confidence interval 0.36-1.75, P = 0.567). Subgroup analysis on medium EV showed the CARV combination group had a more favorable effect in promoting EV regression (43.5% vs 13.1%, P = 0.022) than NUC alone, but not in small cases ( P = 0.534). The incidence of liver-related events (decompensation, hepatocellular carcinoma, or death/liver transplantation) within 2 years was similar between the 2 groups (11.2% vs 10.4%, P = 0.881). DISCUSSION: The overall results did not show statistically significant differences between the added carvedilol strategy and NUC monotherapy in preventing EV progression in patients with virologically suppressed HBV-compensated cirrhosis. However, the carvedilol-added approach might offer improved outcomes specifically for patients with medium EV (NCT03736265).


Assuntos
Vírus da Hepatite B , Neoplasias Hepáticas , Humanos , Carvedilol/uso terapêutico , Antivirais/uso terapêutico , Cirrose Hepática/tratamento farmacológico
2.
BMC Gastroenterol ; 24(1): 139, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38649806

RESUMO

BACKGROUND: Gastric hamartomatous inverted polyps (GHIPs) are not well characterized and remain diagnostically challenging due to rarity. Therefore, this study aims to investigate the clinicopathologic and endoscopic characteristics of patients with GHIP. METHODS: We retrospectively reviewed clinicopathologic and endoscopic features of ten patients with GHIP who were admitted to Beijing Friendship Hospital from March 2013 to July 2022. All patients were treated successfully by endoscopic resection. RESULTS: GHIPs were usually asymptomatic and found incidentally during gastroscopic examination. They may be sessile or pedunculated, with diffuse or local surface redness or erosion. On endoscopic ultrasonography, the sessile submucosal tumor-type GHIP demonstrated a heterogeneous lesion with cystic areas in the third layer of the gastric wall. Histologically, GHIPs were characterized by a submucosal inverted proliferation of cystically dilated hyperplastic gastric glands accompanied by a branching proliferation of smooth muscle bundles. Inflammatory cells infiltration was observed in the stroma, whereas only one patient was complicated with glandular low-grade dysplasia. Assessment of the surrounding mucosa demonstrated that six patients (60%) had atrophic gastritis or Helicobacter pylori-associated gastritis, and four patients (40%) had non-specific gastritis. Endoscopic resection was safe and effective. CONCLUSIONS: GHIPs often arise from the background of abnormal mucosa, such as atrophic or H.pylori-associated gastritis. We make the hypothesis that acquired inflammation might lead to the development of GHIPs. We recommend to make a full assessment of the background mucosa and H. pylori infection status for evaluation of underlying gastric mucosal abnormalities, which may be the preneoplastic condition of the stomach.


Assuntos
Pólipos Adenomatosos , Endossonografia , Mucosa Gástrica , Gastroscopia , Hamartoma , Pólipos , Neoplasias Gástricas , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Estudos Retrospectivos , Hamartoma/patologia , Hamartoma/diagnóstico por imagem , Hamartoma/cirurgia , Neoplasias Gástricas/patologia , Neoplasias Gástricas/cirurgia , Neoplasias Gástricas/diagnóstico por imagem , Mucosa Gástrica/patologia , Mucosa Gástrica/diagnóstico por imagem , Mucosa Gástrica/cirurgia , Adulto , Idoso , Pólipos/patologia , Pólipos/cirurgia , Pólipos/diagnóstico por imagem , Gastropatias/patologia , Gastropatias/cirurgia , Gastropatias/diagnóstico por imagem , Infecções por Helicobacter/complicações , Infecções por Helicobacter/patologia , Helicobacter pylori/isolamento & purificação , Gastrite/patologia , Gastrite/complicações , Gastrite/diagnóstico por imagem , Gastrite Atrófica/patologia , Gastrite Atrófica/complicações , Ressecção Endoscópica de Mucosa
3.
Ecol Lett ; 26(5): 816-826, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36958943

RESUMO

Global greening, characterized by an increase in leaf area index (LAI), implies an increase in foliar carbon (C). Whether this increase in foliar C under climate change is due to higher photosynthesis or to higher allocation of C to leaves remains unknown. Here, we explored the trends in foliar C accumulation and allocation during leaf green-up from 2000 to 2017 using satellite-derived LAI and solar-induced chlorophyll fluorescence (SIF) across the Northern Hemisphere. The accumulation of foliar C accelerated in the early green-up period due to both increased photosynthesis and higher foliar C allocation driven by climate change. In the late stage of green-up, however, we detected decreasing trends in foliar C accumulation and foliar C allocation. Such stage-dependent trends in the accumulation and allocation of foliar C are not represented in current terrestrial biosphere models. Our results highlight that a better representation of C allocation should be incorporated into models.


Assuntos
Carbono , Mudança Climática , Fotossíntese , Folhas de Planta , Ecossistema
4.
Glob Chang Biol ; 29(11): 3147-3158, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36883758

RESUMO

Canopy greening, which is associated with significant canopy structure changes, is the most notable signal of ecosystem changes in response to anthropogenic climate change. However, our knowledge of the changing pattern of canopy development and senescence, and its endogenous and climatic drivers is still limited. Here, we used the Normalized Difference Vegetation Index (NDVI) to quantify the changes in the speed of canopy development and senescence over the Tibetan Plateau (TP) during 2000-2018, and used a solar-induced chlorophyll fluorescence dataset as a proxy for photosynthesis, in combination with climate datasets to decipher the endogenous and climatic drivers of the interannual variation in canopy changes. We found that the canopy development during the early green-up stage (April-May) is accelerating at a rate of 0.45-0.8 × 10-3  month-1  year-1 . However, this accelerating canopy development was largely offset by a decelerating canopy development during June and July (-0.61 to -0.51 × 10-3  month-1  year-1 ), leading to the peak NDVI over the TP increasing at a rate of only one fifth of that in northern temperate regions, and less than one tenth of that in the Arctic and boreal regions. During the green-down period, we observed a significant accelerating canopy senescence during October. Photosynthesis was found to be the dominant driver for canopy changes over the TP. Increasing photosynthesis stimulates canopy development during the early green-up stage. However, slower canopy development and accelerated senescence was found with larger photosynthesis in late growth stages. This negative relationship between photosynthesis and canopy development is probably linked to the source-sink balance of plants and shifts in the allocation regime. These results suggest a sink limitation for plant growth over the TP. The impact of canopy greening on the carbon cycle may be more complicated than the source-oriented paradigm used in current ecosystem models.


Assuntos
Ecossistema , Fotossíntese , Tibet , Estações do Ano , Fotossíntese/fisiologia , Plantas
5.
J Biochem Mol Toxicol ; 37(3): e23264, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36482494

RESUMO

Ovarian cancer is the leading cause of gynecological cancer-related death in women, and is difficult to treat. The aim of our study is to explore the role and action mechanism of hsa_circ_0000119 in ovarian cancer, thus to analyze whether the circular RNA is a potential target for the treatment of the disease. In this present study, our data shows that hsa_circ_0000119 and DNA methyltransferase 1 (DNMT1) was increased, while miR-142-5p was decreased in ovarian cancer. Overexpression of hsa_circ_0000119 promoted tumor growth, while silencing of hsa_circ_0000119 resulted in an opposite effects. Decreasing of hsa_circ_0000119 also notably inhibited the proliferation, migration, and invasion of the ovarian cancer cells. Moreover, the data proves that hsa_circ_0000119 negatively regulated miR-142-5p and cadherin 13 (CDH13) expression, but positively regulated DNMT1 expression. miR-142-5p could interact with hsa_circ_0000119 and DNMT1 3'-UTR. Silencing of DNMT1 could reverse the inhibition of hsa_circ_0000119 to miR-142-5p and CDH13 expression. Importantly, higher level of CDH13 promoter methylation existed in the ovarian tumors than that in matched normal tissues. DNA methyltransferase inhibitor could increase the expression of CDH13 in ovarian cancer cells. In addition, our results also prove that increasing of CDH13 or miR-142-5p effectively reversed the inhibition of hsa _circ_0000119 to the cell malignant phenotypes. Overall, our data demonstrate that hsa_circ_0000119 facilitated ovarian cancer development through increasing CDH13 expression via promoting DNMT1 expression by sponging miR-142-5p. Our data demonstrate the potential role of hsa_circ_0000119 in the treatment of ovarian cancer.


Assuntos
Carcinoma Epitelial do Ovário , Neoplasias Ovarianas , RNA Circular , Carcinoma Epitelial do Ovário/genética , Carcinoma Epitelial do Ovário/metabolismo , Carcinoma Epitelial do Ovário/patologia , Linhagem Celular Tumoral , Metilação de DNA , Processos Neoplásicos , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , RNA Circular/genética , RNA Circular/metabolismo
6.
Int J Biometeorol ; 67(9): 1409-1421, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37479847

RESUMO

Evaluating the interactions between cold requirements for leaf coloration and environmental cues is crucial for understanding the mechanisms of leaf senescence and accurately predicting autumn phenology. Based on remote sensing-derived and ground-observed leaf coloration dates for deciduous broadleaf forests during 1981-2014, we determined location-specific cold requirements for autumn leaf coloration and assessed their spatiotemporal changes. Then, we revealed the major environmental cues of cold requirements and their spatial differentiation. Results show that cold requirements have nonsignificant trends during the past decades at 57.9% of pixels. The interannual variation of cold requirements was mainly influenced by growing-season accumulated temperature (GDDgs) at 35.8% of pixels and accumulated growing season index (AGSI) at 23.2% of pixels, but less affected by leaf unfolding and low precipitation index (LPI). The increase in GDDgs or AGSI may decrease cold requirements, and vice versa. The spatial differentiations of the effects of GDDgs and AGSI depend highly on local summer temperature among climatic classifications with similar humidity conditions. Specifically, the effects of GDDgs on cold requirements concentrated in humid regions with warmer summers, while that of AGSI mainly occurred in humid and winter dry regions with cooler summers. Higher summer temperatures would strengthen the effects of GDDgs and reduce the effects of AGSI on cold requirements. These findings deepen the understanding of the influences of environmental factors on leaf senescence progress and suggest that the shifts of factors affecting cold requirements under global warming may enlarge the uncertainty in predicting autumn leaf coloration dates.


Assuntos
Sinais (Psicologia) , Árvores , Florestas , Estações do Ano , Temperatura , Folhas de Planta , Mudança Climática
7.
Environ Toxicol ; 38(7): 1732-1742, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37014014

RESUMO

Preliminary researches have confirmed that the number of apoptosis of adipose tissue-derived stem cells (ADSCs) in patients with diabetes is significantly increased, leading to a difficult healing wound. Increasing researches revealed that circular RNAs (circRNAs) can control apoptosis. However, it is still unclear whether and how circRNAs are critical for regulating ADSCs apoptosis. In this study, we utilized in vitro model in which ADSCs were cultivated with normal glucose (NG) (5.5 mM) or high glucose (HG) (25 mM) medium, respectively, and found that more apoptotic ADSCs were observed in HG medium comparing to ADSCs in NG medium. Furthermore, we found that hsa_circ_0008500 attenuated HG-mediated ADSCs apoptosis. In addition, Hsa_circ_0008500 could directly interact with hsa-miR-1273h-5p, acting as a miRNA sponge, which subsequently suppressed Ets-like protein-1(ELK1) expression, the downstream target of hsa-miR-1273h-5p. Thus, these results indicated that targeting the hsa_circ_0008500/hsa-miR-1273h-5p/ELK1 signaling pathway in ADSCs may be a potential target for repairing diabetic wounds.


Assuntos
MicroRNAs , RNA Circular , Humanos , RNA Circular/genética , RNA Circular/metabolismo , Linhagem Celular Tumoral , MicroRNAs/genética , MicroRNAs/metabolismo , Células-Tronco , Apoptose/genética , Glucose/farmacologia , Proliferação de Células/genética , Proteínas Elk-1 do Domínio ets
8.
Glob Chang Biol ; 28(23): 6961-6972, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36054628

RESUMO

Global vegetation greening has been widely confirmed in previous studies, yet the changes in the velocity of green-up in each month of green-up period (GUP) remains unclear. Here, we defined the velocity of vegetation green-up as VNDVI (the monthly increase of Normalized Difference Vegetation Index [NDVI] during GUP) and further explored its response to climate change in middle-high-latitude Northern Hemisphere. We found that in early GUP, VNDVI generally showed positive trends from 1982 to 2015, whereas in late GUP, it showed negative trends in most areas. Such contrasting trends were mainly due to a positive temperature effect on VNDVI in early GUP, but this effect turned negative in late GUP. The increase of soil moisture also in part explained the accelerated vegetation green-up, especially in the arid and semi-arid ecosystems of inland areas. Our analyses also indicate that the first month of the GUP was the key stage impacting vegetation greenness in summer. Future warming may continuously speed up the early growth of vegetation, altering the seasonal trajectory of vegetation and its feedbacks to the Earth system.


Assuntos
Mudança Climática , Ecossistema , Temperatura , Estações do Ano , Solo , China
9.
Mol Cell Biochem ; 477(6): 1669-1679, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35235125

RESUMO

Dysregulated circRNAs have potential roles in the progression of various cancer types, including cervical cancer (CaCx). The carcinogenic roles of circRNA Wolf-Hirschhorn syndrome candidate gene-1 (circWHSC1) are described in the development of diverse cancers. The objective of this study was to investigate the expression and the underlying role of circWHSC1 in CaCx. The expression of circWHSC1 was detected by real-time PCR. After the suppression of circWHSC1 expression, the changes in the proliferation, migration, invasion, and apoptosis capacities were detected by CCK-8 assay, colony formation assay, Transwell assays, flow cytometry, and the determination of apoptosis-related proteins. The interplay among circWHSC1, miR-532-3p, and latent transforming growth factor-ß binding protein 2 (LTBP2) was confirmed by luciferase reporter and biotinylated RNA pull-down assays. A nude mice xenograft tumor model was established to evaluate the anti-tumorigenic role of circWHSC1 silencing in vivo. CircWHSC1 was overexpressed in CaCx tissues and cell lines and its high expression was inversely associated with the survival rate of patients with CaCx. CircWHSC1 silencing was capable of suppressing the proliferation, metastasis, and invasion of tumor cells and inducing apoptosis. Investigation to its molecular mechanism revealed that circWHSC1 functioned as a competitive endogenous RNA (ceRNA), mediating LTBP2 expression by targeting miR-532-3p. The in vivo experiments further confirmed the inhibition of tumor growth and metastasis by circWHSC1 knockdown. The circWHSC1-mediated miR-532-3p/LTBP2 signaling axis might be a novel therapeutic target for CaCx.


Assuntos
MicroRNAs , Neoplasias do Colo do Útero , Animais , Apoptose/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Proteínas de Ligação a TGF-beta Latente/genética , Proteínas de Ligação a TGF-beta Latente/metabolismo , Camundongos , Camundongos Nus , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Circular/genética , Neoplasias do Colo do Útero/genética
10.
J Gastroenterol Hepatol ; 37(7): 1275-1283, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35342997

RESUMO

BACKGROUND AND AIM: Duodenal ulcers, especially caused by increasingly drug-resistant Helicobacter pylori, are a concern in Asia. We compared oral vonoprazan versus lansoprazole for efficacy (healing duodenal ulcers) and safety in non-Japanese Asian patients. METHODS: In this phase 3, randomized (1:1), double-blind, double-dummy, parallel-group, non-inferiority study (April 5, 2017, to July 19, 2019), patients with ≥ 1 endoscopically confirmed duodenal ulcer, at 52 hospitals (China, South Korea, and Taiwan), received vonoprazan 20 mg once daily (QD) or lansoprazole 30 mg QD for 6 weeks maximum. Patients with H. pylori received bismuth-containing quadruple therapy including vonoprazan 20 mg twice daily (BID) or lansoprazole 30 mg BID, for 2 weeks, followed by vonoprazan or lansoprazole monotherapy QD (4 weeks maximum). Endpoints were endoscopically confirmed duodenal ulcer healing (Week 4/6; primary) and H. pylori eradication (4 weeks post-treatment; secondary); non-inferiority margins were -6% and -10%, using a two-sided 95% confidence interval (CI). RESULTS: Of 533 enrolled patients, one was lost to follow-up and one withdrew (full analysis set: 531 patients [vonoprazan, n = 263; lansoprazole, n = 268]; 85.4% = H. pylori positive). Vonoprazan was non-inferior to lansoprazole for duodenal ulcer healing (96.9% vs 96.5%; difference 0.4% [95% CI -3.00, 3.79]). H. pylori eradication rates were 91.5% (vonoprazan) and 86.8% (lansoprazole; difference 4.7% [95% CI -1.28, 10.69]). Vonoprazan and lansoprazole were well tolerated, with similar safety profiles, no new safety signals; no deaths occurred. CONCLUSIONS: Vonoprazan was well tolerated and non-inferior to lansoprazole for duodenal ulcer healing and achieved H. pylori eradication above the clinically meaningful threshold (90%), in non-Japanese Asian patients.


Assuntos
Antiulcerosos , Úlcera Duodenal , Infecções por Helicobacter , Helicobacter pylori , Amoxicilina , Antiulcerosos/efeitos adversos , Claritromicina , Método Duplo-Cego , Quimioterapia Combinada , Úlcera Duodenal/induzido quimicamente , Úlcera Duodenal/tratamento farmacológico , Infecções por Helicobacter/tratamento farmacológico , Humanos , Lansoprazol/efeitos adversos , Recidiva Local de Neoplasia , Pirróis , Sulfonamidas
11.
Small ; 17(4): e2005493, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33369100

RESUMO

It has long been demonstrated the gecko-inspired micropillar array with T-shape tips possesses the best adhesion performance of a given material. The further enhancement of the adhesion performances of T-shape micropillars can offer redundant adhesion to compensate for the inevitable improper contacts. Here, the array of T-shape polydimethylsiloxane (PDMS) micropillars is incorporated with gradient dispersed calcium carbonate nanoparticles in the micropillar stalk, termed as T-shape gradient micropillars (TG), possessing the modulus gradient with stiff tip and soft root. The gradient modulus in TG facilitates the contact formation and regulates the stress at the detaching interface, resulting in a 4.6 times adhesion and 2.4 times friction as compared with the pure PDMS T-shape micropillar arrays. The study here provides a new design strategy for the super-strong structured dry adhesives.


Assuntos
Lagartos , Nanopartículas , Adesivos , Animais , Anuros , Fricção
12.
BMC Surg ; 21(1): 361, 2021 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-34627222

RESUMO

INTRODUCTION: Although the traditional bilateral surgical approach to treat hiatal hernia (HH) with gastroesophageal reflux disease (GERD) can provide local protection of the vagus nerve, the integrity of the entire vagus nerve cannot be evaluated. Therefore, we developed and described the total left-side surgical approach (TLSA), which theoretically reduces injury to the vagus nerve, and described the detailed surgical procedure. METHODS: Initially, we performed a cadaver study to explore the characteristics of the vagus nerve. Then, we prospectively evaluated the TLSA in 5 patients with HH and GERD between June 2020 and September 2020. Demographic characteristics, surgical parameters, perioperative outcomes, and follow-up findings were analyzed. RESULTS: The TLSA was successfully used in five patients (40-64 years old), and no major complications were noted. The median total operative time was 114 min, median blood loss was 50 mL, and median postoperative hospital stay was 3.8 days. Gastrointestinal function recovered within 4 days of surgery in all the patients. The 6-month follow-up gastroscopy examination showed well-established gastroesophageal flap valves. Compared with the baseline results, the 6-month follow-up results showed lower values for the total GerdQ score (12.4 vs. 6.2) and the total esophageal acid exposure time (3.48% vs. 0.38%). Based on the European Organization for Research and Treatment of Cancer quality of life questionnaire-stomach module 52 results, the incidence of dysphagia and flatulence decreased over time after the TLSA. CONCLUSIONS: The TLSA provides a clear and broad surgical field, less trauma, and rapid recovery; moreover, it is technically simple. Although our results suggest that the TLSA provides safety and short-term efficacy and is feasible for patients with HH and GERD, long-term results from a larger clinical trial are needed to validate these findings. Trial registration ChiCTR2000034028, registration date is June 21, 2020. The study was registered prospectively.


Assuntos
Refluxo Gastroesofágico , Hérnia Hiatal , Laparoscopia , Adulto , Refluxo Gastroesofágico/cirurgia , Hérnia Hiatal/cirurgia , Humanos , Pessoa de Meia-Idade , Qualidade de Vida , Resultado do Tratamento
13.
Dig Endosc ; 33(7): 1110-1119, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33527576

RESUMO

OBJECTIVE: The topical antispasmodic agent l-menthol is commonly used for gastric peristalsis suppression during diagnostic upper gastrointestinal (GI) endoscopy. We evaluated the efficacy and safety of a single dose l-menthol solution in suppressing gastric peristalsis during upper GI endoscopy in Chinese patients. METHODS: In this phase III, multicenter, randomized, double-blind, placebo-controlled study (ClinicalTrials.gov: NCT03263910), 220 patients scheduled to undergo upper GI endoscopy at five Chinese referral centers received a single dose of either 160 mg of l-menthol (n = 109) or placebo (n = 111). Both treatments were sprayed endoscopically on the gastric mucosa. An independent committee evaluated the degree of gastric peristalsis (peristaltic score: grade 1-5). RESULTS: At baseline, the proportion of patients with grade 1 peristalsis (no peristalsis) did not differ between the groups. The proportion of patients with grade 1 peristalsis post-treatment was significantly higher in the l-menthol group (40.37%, 44/109) versus the placebo group (16.22%, 18/111; P < 0.001); the difference between the groups was 24.15% (95% confidence interval: 12.67%-35.63%; P < 0.001). In the l-menthol group, 61.47% of patients had grade 1 peristalsis after endoscopy versus 24.55% in the placebo group (P < 0.001). The ease of intragastric examination correlated significantly with the grade of peristalsis. The incidence of adverse events was comparable between the groups (P = 0.340). CONCLUSIONS: During upper GI endoscopy, a single dose of l-menthol solution (160 mg) sprayed on the gastric mucosa significantly attenuated gastric peristalsis versus placebo, thereby improving the visual stability without any safety concerns.


Assuntos
Antidiarreicos , Mentol , China , Método Duplo-Cego , Endoscopia Gastrointestinal , Mucosa Gástrica , Humanos
14.
Glob Chang Biol ; 26(9): 5189-5201, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32475002

RESUMO

Understanding how the temperature sensitivity of phenology changes with three spatial dimensions (altitude, latitude, and longitude) is critical for the prediction of future phenological synchronization. Here we investigate the spatial pattern of temperature sensitivity of spring and autumn phenology with altitude, latitude, and longitude during 1982-2016 across mid- and high-latitude Northern Hemisphere (north of 30°N). We find distinct spatial patterns of temperature sensitivity of spring phenology (hereafter "spring ST ") among altitudinal, latitudinal, and longitudinal gradient. Spring ST decreased with altitude mostly over eastern Europe, whereas the opposite occurs in eastern North America and the north China plain. Spring ST decreased with latitude mainly in the boreal regions of North America, temperate Eurasia, and the arid/semi-arid regions of Central Asia. This distribution may be related to the increased temperature variance, decreased precipitation, and radiation with latitude. Compared to spring ST , the spatial pattern of temperature sensitivity of autumn phenology (hereafter "autumn ST ") is more heterogeneous, only showing a clear spatial pattern of autumn ST along the latitudinal gradient. Our results highlight the three-dimensional view to understand the phenological response to climate change and provide new metrics for evaluating phenological models. Accordingly, establishing a dense, high-quality three-dimensional observation system of phenology data is necessary for enhancing our ability to both predict phenological changes under changing climatic conditions and to facilitate sustainable management of ecosystems.


Assuntos
Mudança Climática , Ecossistema , China , Europa Oriental , América do Norte , Estações do Ano , Temperatura
15.
Glob Chang Biol ; 26(4): 2630-2641, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31883193

RESUMO

Warming in cold regions alters freezing and thawing (F-T) of soil in winter, exposing soil organic carbon to decomposition. Carbon-rich permafrost is expected to release more CO2 to the atmosphere through ecosystem respiration (Re) under future climate scenarios. However, the mechanisms of the responses of freeze-thaw periods to climate change and their coupling with Re in situ are poorly understood. Here, using 2 years of continuous data, we test how changes in F-T events relate to annual Re under four warming levels and precipitation addition in a semi-arid grassland with discontinuous alpine permafrost. Warming shortened the entire F-T period because the frozen period shortened more than the extended freezing period. It decreased total Re during the F-T period mainly due to decrease in mean Re rate. However, warming did not alter annual Re because of reduced soil water content and the small contribution of total Re during the F-T period to annual Re. Although there were no effects of precipitation addition alone or interactions with warming on F-T events, precipitation addition increased total Re during the F-T period and the whole year. This decoupling between changes in soil freeze-thaw events and annual Re could result from their different driving factors. Our results suggest that annual Re could be mainly determined by soil water content rather than by change in freeze-thaw periods induced by warming in semi-arid alpine permafrost.

16.
Exp Mol Pathol ; 117: 104522, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32866521

RESUMO

OBJECTIVE: This study aimed to investigate whether the protection of miR-302a-3p in myocardial ischemia-reperfusion injury (MIRI) is mediated through the suppression of mitophagy. METHODS: We constructed a mouse I/R model in vivo by the ligation of left anterior descending coronary artery for 45 min followed by 2 h reperfusion, and an in vitro model by treating mouse cardiomyocytes with hypoxia-reoxygenation (H/R). Knockdown experiments were then performed in vivo and in vitro to determine the effects of miR-302a-3p knockdown on the mitophagy, mitochondrial dysfunction and oxidative stress and apoptosis. The potential targets of miR-302a-3p were further studied by bioinformatics analysis, luciferase assays, quantitative real-time PCR and western blotting. RESULTS: MiR-302a-3p expression was significantly upregulated in mice subjected to MIRI and in H/R-treated mouse cardiomyocytes. Functional analyses demonstrated that inhibition of miR-302a-3p protected cardiac tissues against I/R-induced apoptosis and mitophagy, mitochondrial damage and mitochondrial oxidative stress. Furthermore, FOXO3 was identified as the direct target of miR-302a-3p. Mechanistically, knockdown of FOXO3 partially reversed the cardioprotective effects of miR-302a-3p inhibitor. CONCLUSION: Our study suggested that inhibition of miR-302a-3p promoted mitochondrial autophagy and inhibited oxidative stress by targeting FOXO3 to suppress myocardial apoptosis, representing a potential target for MIRI treatment.


Assuntos
Proteína Forkhead Box O3/genética , MicroRNAs/genética , Isquemia Miocárdica/genética , Traumatismo por Reperfusão/genética , Animais , Apoptose/genética , Vasos Coronários/patologia , Vasos Coronários/cirurgia , Modelos Animais de Doenças , Regulação da Expressão Gênica/genética , Técnicas de Silenciamento de Genes , Humanos , Ligadura , Camundongos , Mitofagia/genética , Isquemia Miocárdica/patologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Estresse Oxidativo/genética , Traumatismo por Reperfusão/patologia
17.
Philos Trans A Math Phys Eng Sci ; 377(2150): 20190131, 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31177956

RESUMO

Enlarged adhesive toe pads on the tip of each digit allow tree frogs to climb smooth vertical and overhanging surfaces, and are effective in generating reversible adhesion under both dry and wet conditions. In this review, we discuss the complexities of the structure of tree frog toe pads in relation to their function and review their biomimetic potential. Of particular importance are the (largely) hexagonal epithelial cells surrounded by deep channels that cover the surface of each toe pad and the array of nanopillars on their surface. Fluid secreted by the pads covers the surface of each pad, so the pads adhere by wet adhesion, involving both capillarity and viscosity-dependent forces. The fabrication and testing of toe pad mimics are challenging, but valuable both for testing hypotheses concerning tree frog toe pad function and for developing toe pad mimics. Initial mimics involved the fabrication of hexagonal pillars mimicking the toe pad epithelial structure. More recent ones additionally replicate the nanostructures on their surface. Finally we describe some of the biomimetic applications that have been developed from toe pad mimics, which include both bioinspired adhesives and friction-generating devices. This article is part of the theme issue 'Bioinspired materials and surfaces for green science and technology (part 2)'.


Assuntos
Adesivos , Anuros , Materiais Biomiméticos , Adesividade , Adesivos/química , Adesivos/normas , Animais , Materiais Biomiméticos/química , Propriedades de Superfície
18.
Can J Microbiol ; 65(5): 365-376, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30566369

RESUMO

Intact Tibetan meadows provide significant defense against soil-borne pathogen dispersal. However, dramatic meadow degradation has been observed due to climate change and pika damage, but their impacts on soil-borne pathogens are still unclear. With approximately 40% of the world's population living in Tibetan Plateau and its downstream watersheds, this lack of knowledge should be of great concern. Here, we used Illumina amplicon sequencing to characterize the changes in potential human, domestic animal, plant, and zoonotic bacterial and fungal pathogens in nondegraded, desertified, and pika-burrowed meadows. The relative abundance of bacterial domestic animal pathogens and zoonotic pathogens were significantly increased by desertification. Pika burrowing significantly increased the relative abundance of bacterial human pathogens and zoonotic pathogens. The species richness and relative abundance of fungal pathogens was significantly increased by desertification and pika burrowing. Accordingly, fungal plant and animal pathogens categorized by FUNGuid significantly increased in desertified and pika-burrowed meadows. Soil chemical and plant properties explained 38% and 64% of the bacterial and fungal pathogen community variance, respectively. Therefore, our study indicates for the first time that both alpine meadow desertification and pika burrowing could potentially increase infectious disease risks in the alpine ecosystem, especially for fungal diseases.


Assuntos
Doenças Transmissíveis/microbiologia , Fungos , Pradaria , Lagomorpha/microbiologia , Doenças das Plantas/microbiologia , Plantas/microbiologia , Microbiologia do Solo , Animais , Mudança Climática , Ecossistema , Humanos , Medição de Risco , Solo/química , Tibet , Tundra
19.
J Cell Biochem ; 119(10): 8611-8622, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29923216

RESUMO

Betulinic acid (BA), a natural product with a broad range of biological properties, is a lupane-type pentacyclic triterpene isolated from various plants. Evidence is accumulating that BA is cytotoxic against multiple types of human cancer cells; however, its effects on renal carcinoma cells remain obscure. This study aimed to evaluate the anticancer activity of BA in human renal cancer cells in vitro and in vivo. In the current study, we found that BA inhibited renal cancer cell proliferation in a time-dependent and dose-dependent manner in vitro. Moreover, flow cytometry analysis revealed that BA affected the survival of renal cancer cells via the induction of apoptosis. Western blot analysis showed that the occurrence of apoptosis was associated with upregulation of Bcl2-associated X protein and cleaved caspase-3 and downregulation of B-cell lymphoma 2 in renal cancer cells. Additionally, BA treatment augmented the production of reactive oxygen species and induced a significant loss of mitochondrial membrane potential in renal cancer cells, suggesting that BA may trigger apoptosis via the mitochondria-mediated apoptotic pathway. Furthermore, the migrative and invasive capabilities of renal cancer cells were markedly repressed by BA treatment, which was related to upregulation of matrix metalloproteinase (MMP)2, MMP9, and vimentin, and downregulation of tissue inhibitor of metalloproteinase 2 and E-cadherin. Notably, administration of BA retarded tumor growth in 786-O-bearing mice in vivo. Taken together, our results demonstrated the anticancer potential of BA in human renal cancer cells by triggering apoptosis and suppressing migration and invasion.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Apoptose/efeitos dos fármacos , Carcinoma de Células Renais/tratamento farmacológico , Neoplasias Renais/tratamento farmacológico , Triterpenos/uso terapêutico , Análise de Variância , Animais , Carcinoma de Células Renais/secundário , Caspase 3/metabolismo , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Neoplasias Renais/patologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Invasividade Neoplásica , Metástase Neoplásica , Triterpenos Pentacíclicos , Espécies Reativas de Oxigênio/metabolismo , Resultado do Tratamento , Carga Tumoral , Ensaios Antitumorais Modelo de Xenoenxerto , Proteína X Associada a bcl-2/metabolismo , Ácido Betulínico
20.
Surg Endosc ; 31(11): 4665-4672, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28411346

RESUMO

BACKGROUND: This study retrospectively compared the safety and efficacy of two endoscopic techniques for treating newly diagnosed achalasia, pneumatic dilation (PD), and peroral endoscopic myotomy (POEM). METHODS: Demographics, clinical and manometric data, and outcomes were collected from the medical records of patients who received POEM or PD as the primary therapy for achalasia at our hospital from January 2012 to August 2015. RESULTS: Of 72 patients, 32 and 40 received POEM and PD, respectively. The two groups had similar preoperative features. On short-term follow-up, improvements in high-resolution esophageal manometry and barium esophagogram parameters were similar. For PD, the success rates at 3, 6, 12, 24, and 36 months were 95, 88, 75, 72, and 60%, respectively. For POEM, these were 96, 96, 96, 93, and 93% (P = 0.013, log-rank test). On subgroup analysis, the success rate was higher with POEM than that with PD in all 3 manometric subtypes, but only that of type III was statistically significant. POEM required significantly longer operative time and hospitalization than did PD (P < 0.001). Four POEM patients experienced subcutaneous emphysema. The rate of gastroesophageal reflux was higher in patients treated by POEM (18.8%) than that in PD (10%; P = 0.286). CONCLUSIONS: In the intermediate term, the remission rate of symptoms associated with POEM therapy was better than that with PD for newly diagnosed achalasia, especially in patients with type III achalasia. The short-term outcomes of the two therapies were similar.


Assuntos
Endoscopia/métodos , Acalasia Esofágica/cirurgia , Esfíncter Esofágico Inferior/cirurgia , Miotomia/métodos , Adulto , Idoso , Dilatação/efeitos adversos , Dilatação/métodos , Endoscopia/efeitos adversos , Esôfago/fisiopatologia , Esôfago/cirurgia , Feminino , Seguimentos , Humanos , Masculino , Manometria/métodos , Pessoa de Meia-Idade , Miotomia/efeitos adversos , Cirurgia Endoscópica por Orifício Natural/efeitos adversos , Cirurgia Endoscópica por Orifício Natural/métodos , Duração da Cirurgia , Estudos Retrospectivos , Análise de Sobrevida , Resultado do Tratamento
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