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1.
Chemosphere ; 249: 126039, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-32062202

RESUMO

Many research focused on the removal of perfluorooctane sulfonic acid (PFOS) and hexavalent chromium (Cr(VI)) in some industrial wastewater (e.g. electroplating wastewater), but few research reported the combined toxicity of PFOS and Cr(VI) to soil bacteria. Therefore, the toxicity and mechanisms of the combined PFOS and Cr(VI) to bacteria (with Bacillus subtilis as a model) are explored. The results show that the combined PFOS and Cr(VI) exhibits much higher toxicity to the bacteria than that of Cr(VI) alone. The growth profile of Bacillus subtilis exposed by the combined pollution decreased by 18% and 56%, respectively, compared with that of single Cr(VI) and the control, indicating the combined toxicity to Bacillus subtilis is synergistic. Moreover, the changes of EPSs in Bacillus subtilis, such as decreased potential, increased extracellular polysaccharides, decreased extracellular proteins and irregular morphology, also confirmed that the combined PFOS and Cr(VI) caused greater toxicity. The increase of intracellular ROS and permeability of dye 4', 6-diamidino-2-phenylindoledihydrochloride (DAPI) suggest that oxidative damage and increased membrane permeability are the main mechanisms of toxicity induced by the combined PFOS and Cr(VI). This work could provide useful information for the risk assessment of co-exposure to PFOS and heavy metals in the natural environment.

2.
Biosci Rep ; 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31904088

RESUMO

Parietal cells of the gastric mucosa contain a complex and extensive secretory membrane system that harbors gastric H+, K+-adenosine triphosphatase, the enzyme primarily responsible for gastric lumen acidification. Here, we describe the characterization of mice deficient in the H+, K+-ATPase α subunit (Atp4a-/-) to determine the role of this protein in the biosynthesis of this membrane system and the biology of the gastric mucosa. Wild-type and Atp4a-/- mice, paired for age, were examined at 10, 12, 14 and 16 weeks for histopathology, and the expression of MUC2, AMACR, Ki-67, and p53 proteins was analyzed by immunohistochemistry. For further information, PI3K, AKT, mTOR, HIF-1α, LDHA, and SIRT6 were detected by western blotting. Compared to the WT mice,  Atp4a-/- mice developed parietal cell atrophy and significant antral inflammation and intestinal metaplasia with elevated MUC2 expression. Areas of dysplasia in the Atp4a-/- mouse stomach showed increased AMACR and Ki-67 expression. Consistent with elevated antral proliferation, tissue isolated from Atp4a-/- mice showed elevated p53 expression. The expression of P-PI3K, P-AKT, P-mTOR, HIF-1α, LDHA, and SIRT6 was significantly higher in tissue from the Atp4a-/- mice compared with the WT mice. The H+, K+-ATPase α subunit is required for acid-secretory activity of parietal cells in vivo, the normal development and cellular homeostasis of the gastric mucosa, and attainment of the normal structure of the secretory membranes. Chronic achlorhydria and hypergastrinemia in aged Atp4a-/- mice produced progressive hyperplasia and mucolytic and intestinal metaplasia and activated the Warburg effect via PI3K/AKT/mTOR signaling.

3.
Science ; 367(6475): 272-277, 2020 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-31949075

RESUMO

One great challenge in understanding the history of life is resolving the influence of environmental change on biodiversity. Simulated annealing and genetic algorithms were used to synthesize data from 11,000 marine fossil species, collected from more than 3000 stratigraphic sections, to generate a new Cambrian to Triassic biodiversity curve with an imputed temporal resolution of 26 ± 14.9 thousand years. This increased resolution clarifies the timing of known diversification and extinction events. Comparative analysis suggests that partial pressure of carbon dioxide (Pco2) is the only environmental factor that seems to display a secular pattern similar to that of biodiversity, but this similarity was not confirmed when autocorrelation within that time series was analyzed by detrending. These results demonstrate that fossil data can provide the temporal and taxonomic resolutions necessary to test (paleo)biological hypotheses at a level of detail approaching those of long-term ecological analyses.

4.
Sci Total Environ ; 703: 135015, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-31733496

RESUMO

As a carrier of perfluorooctane sulfonate, nano-plastics are ubiquitous and finally enriched in the sludge, which is widely used as a raw material for the production of bioenergy (hydrogen or methane) by anaerobic digestion. However, there are still many unknowns about their metabolic toxicity to functional microbes (e.g. hydrogen-producing thermophilic bacteria). Therefore, single and combined effects of amino polystyrene (NPS: 70 nm; 0.2 mg/L) and perfluorooctane sulfonate (PFOS: 0.1, 1 and 5 mg/L) on hydrogen-producing thermophilic bacteria were investigated after exposure for 7 days at 55 °C and pH = 5.7. Single NPS exhibited obvious interference to the metabolism of thermophilic bacteria, resulting in a 53.9% reduction in hydrogen production. However, the combined NPS + PFOS produced an antagonistic effect, leading to a 31.6% reduction in hydrogen production. Nonetheless, the single and combined exposure did not alter the type of hydrogen production (acetic acid-type hydrogen fermentation). Moreover, single NPS and combined NPS + PFOS not only induced the changes of the composition of extracellular polymers (EPSs) and π bond structure of the protein in EPSs, but also decreased the activity of hydrolase in EPSs and surface charge of EPSs. Compared to single NPS exposure, NPS + PFOS-exposed thermophilic bacteria was less permeable to a semi-membrane permeable dye and produced less reactive oxygen species, but were still significantly higher than control group. In short, the main mechanisms of single NPS and combined NPS + PFOS were both to increase cell permeability and to induce oxidative stress. The addition of PFOS alleviated the toxic effect of NPS, but did not change its mechanism of toxicity.

5.
Spec Care Dentist ; 40(1): 71-78, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31858622

RESUMO

AIMS: The dental activities test (DAT), designed to assess individuals' ability to perform oral health-related activities, was initially tested among 90 assisted living residents with normal to severely impaired cognition. This study aimed to examine the reliability (internal consistency), convergent validity, and structural validity of DAT among individuals with stroke. METHODS AND RESULTS: This study was a secondary analysis of data collected for a cross-sectional study that aimed to understand oral disease patterns among 207 individuals with stroke from three hospitals in China. Convergent validity was examined using Spearman's Correlation coefficient (rs ) for correlation between DAT scores and the assessments of physical function and cognition. Structural validity was examined using Confirmatory Factor Analysis (CFA). The DAT demonstrated good estimates for internal consistency (Kuder Richardson-20 = 0.85, 95% confidence of interval [CI] = 0.82, 0.88), convergent validity (rs range: 0.43-0.61, all P < .001), and good structural validity with a one-factor structure. CONCLUSION: Findings supported the reliability and validity of DAT as a unidimensional construct in measuring the ability to perform oral health-related activities in persons with stroke. Further testing among different patient populations and care settings is needed to accumulate evidence and expand the use of the test.


Assuntos
Acidente Vascular Cerebral , China , Estudos Transversais , Análise Fatorial , Humanos , Psicometria , Reprodutibilidade dos Testes , Inquéritos e Questionários
6.
Onco Targets Ther ; 12: 9239-9248, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31819473

RESUMO

Background: Ovarian cancer is characterized by high metastatic potential and high mortality. More than 80% of primary ovarian malignancies are epithelial ovarian cancers. There is increasing evidence that Speckle-type POZ protein (SPOP) is highly correlated with the development of various types of cancer. However, the effects of SPOP on epithelial ovarian cancer and the associated molecular mechanisms remain unclear. Materials and methods: We compared SPOP expression between epithelial ovarian cancer tissues and normal ovarian tissues by using immunohistochemical staining. To determine the role of SPOP in epithelial ovarian cancer cells, we overexpressed or knocked down SPOP in the epithelial ovarian cancer cell line OVCAR-3 using lentiviral vectors. Results: Our results from the present study indicated that SPOP expression was significantly downregulated in human epithelial ovarian cancer and was associated with the FIGO stage and the histopathologic grading of the tumor. The overexpression and knockdown experiments revealed that SPOP inhibited proliferation while promoting apoptosis in ovarian cancer cells. Inhibition of SPOP mis-activated the Hedgehog (Hh) signaling pathway, thereby inhibiting apoptosis in ovarian cancer cells. Conclusion: SPOP suppresses proliferation and promotes apoptosis in human ovarian cancer cells by inhibiting the Hh signaling pathway, offering the possibility of new approaches for the treatment of ovarian cancer.

7.
Medicine (Baltimore) ; 98(49): e18030, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31804309

RESUMO

BACKGROUND: This study systematically reviews the data for transcatheter arterial chemoembolization (TACE) alone or combined TACE and cryoablation therapy of hepatocellular carcinoma, aiming to provide clinical choice references for treatment of cancer. METHODS: Electronic databases (PubMed, EMBASE, China National Knowledge Infrastructure, and Google Scholar) were systematically searched to include relevant studies published in English and Chinese between Jan 1, 2000, to July 31, 2017. The analysis was conducted in RevMan 5.3 based on random effects models. RESULTS: Nineteen trials (n = 1427) were included. Combined TACE and cryoablation therapy had higher survival rate (1-year survival [RR 1.37; 95%-CI 1.26,1.49], 2-year survival [RR 1.50; 95%-CI 1.25,1.79], 3-year survival [RR 1.67; 95%-CI 1.16,2.40]), complete necrosis [RR 2.53; 95%-CI 2.07,3.10] and tumor control [RR 1.57; 95%-CI 1.40,1.75], which is more favorable for long-term efficacy of non-surgical hepatocellular carcinoma. Tumor recurrence of control group was above combination therapy [RR 0.27; 95%-CI 0.17, 0.43]. Compared with transcatheter arterial chemoembolization, effect of combination therapy occurred mainly in the survival, complete necrosis, tumor control, and recurrence. Taking combination therapy was generally more effective than taking TACE only. CONCLUSION: Compared with TACE only used to treat cancer, combination therapy had the best effect profile in general, and it had better survival in HCC when taking an integrated approach. The prognosis of treatments based on combination therapy is modulated by cryoablation.


Assuntos
Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica/métodos , Criocirurgia/métodos , Neoplasias Hepáticas/terapia , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/cirurgia , Terapia Combinada , Humanos , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/cirurgia , Recidiva Local de Neoplasia , Taxa de Sobrevida
8.
Ann Clin Lab Sci ; 49(6): 785-793, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31882430

RESUMO

Diabetes-induced hyperglycemia has a direct damaging effect on ovarian function. Despite its deadly impact on ovaries, the mechanism of this condition has not been fully elucidated. Glucose transporters are involved in glucose uptake and utilization. Many transporters have been detected in the ovaries, but their roles in diabetes-induced ovarian impairment are still unclear. In this study, the goal is to analyze glucose transporter expression in the ovarian follicles of type 1 diabetes mellitus patients and determine their roles within ovarian function impairment. The ovarian function of a mouse model of type 1 diabetes mellitus was evaluated by observing its estrus cycle, follicular development, and ovulation. Subtypes of the glucose transporter (GLUT2, GLUT3, GLUT4, SGLT1, and SGLT2), adenosine monophosphate-activated protein kinase (AMPK), and phosphorylated AMPK (Thr172) were found to be simultaneously present in follicle cells. Compared with nondiabetic control mice, the diabetic mice showed a dysregulated estrus cycle and a significantly higher number of abnormal ova. Furthermore, the expression of multiple glucose transporters was lower than that of phosphorylated AMPK. Phosphorylated AMPK possessed more follicular granulosa cells and oocytes of diabetic mice than in those of the control mice. These results suggest that diabetes-induced hyperglycemia reduces the capability of ovarian follicle cells by downregulating glucose transporter expression, causing decreased glucose uptake and energy deprivation. This impact can potentially impair egg maturation and ovulation.

9.
Medicine (Baltimore) ; 98(50): e18285, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31852104

RESUMO

RATIONALE: Compressive myelopathy and compression fracture of aggressive vertebral hemangioma after parturition is a rare condition. Vertebral body compression fracture and high serum progesterone lead to extraosseous hemangioma enlargment cause narrowing the spinal canal which contribute to compressive myelopathy relate to pregnancy. PATIENT CONCERNS: We report a case of compressive myelopathy and compression fracture of aggressive vertebral hemangioma after parturition in a 35-year-old woman. The patient complained unable to walk and experienced intense pain in the back. DIAGNOSIS: Based on the clinical features and imaging studies, the patient underwent a T4-T6 laminectomy. Histopathology consistent with vertebral hemangioma. INTERVENTIONS: The patient underwent laminectomy for decompression. After subperiosteal dissection of the paraspinal muscles and exposure of the laminae, there was no involvement of the lamina by the tumor. The epidural tumor was removed through the spaces lateral to the thecal sac. Vertebroplasty was performed through T5 pedicles bilaterally and 7 ml of polymethylmethacrylate (PMMA) cement was injected. T4-T6 pedicle screw fixation was performed for segmental fixation and fusion. OUTCOMES: Six months after resection of the tumor the patient remained asymptomatic. She reported no low back pain and had returned to her normal daily activities, with no radiographic evidence of recurrence on MRI. Physical examination revealed that superficial and deep sensation was restored to normal levels in the lower extremities. LESSONS: The occurrence of compressive myelopathy of pregnancy related vertebral hemangiomas is quite unusual. It can lead to serious neurologic deficits if not treated immediately. So, prompt diagnosis is important in planning optimal therapy and preventing morbidity for patients.


Assuntos
Fraturas por Compressão/complicações , Hemangioma/complicações , Parto , Compressão da Medula Espinal/etiologia , Fraturas da Coluna Vertebral/complicações , Neoplasias da Coluna Vertebral/complicações , Vértebras Torácicas , Adulto , Descompressão Cirúrgica/métodos , Feminino , Fraturas por Compressão/diagnóstico , Fraturas por Compressão/cirurgia , Hemangioma/diagnóstico , Hemangioma/cirurgia , Humanos , Imagem por Ressonância Magnética , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons , Compressão da Medula Espinal/diagnóstico , Compressão da Medula Espinal/cirurgia , Fraturas da Coluna Vertebral/diagnóstico , Fraturas da Coluna Vertebral/cirurgia , Neoplasias da Coluna Vertebral/diagnóstico , Neoplasias da Coluna Vertebral/cirurgia , Vertebroplastia/métodos
10.
Polymers (Basel) ; 11(11)2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31766151

RESUMO

Polymer stabilized liquid crystal (PSLC) devices can be used as smart privacy windows that switch between transparent and opaque states. The polyimide alignment layer of a PSLC device is usually obtained by the treatment of polyamide acid (PAA) with temperatures over 200 °C. This hinders the fabrication of PSLC devices on flexible substrates, which melt at these high temperatures. In this work, the fabrication of a PSLC alignment layer using a lower temperature that is compatible with most flexible substrates, is demonstrated. It was found that the treatment of PAA at 150 °C could generate the same alignment for liquid crystals. Based on this, a PSLC device was successfully fabricated on a flexible polyethylene terephthalate (PET) substrate, demonstrating excellent electro-optic performances.

11.
Acta Haematol ; : 1-10, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31597158

RESUMO

BACKGROUND: The aim of this study was to detect the expression of long noncoding RNA small nucleolar RNA host gene 18 (SNHG18) andsemaphorin 5A (SEMA5A) genes in multiple myeloma (MM) patients and to explore the correlation of the expression of these genes with the clinical characteristics and prognosis of MM patients. METHODS: Forty-seven newly diagnosed MM, 18 complete remission MM, 13 refractory/relapse MM, and 22 iron deficiency anemia (serving as control) samples were extracted at the Department of Hematology, Second Affiliated Hospital of Xian Jiaotong University between January 2015 and December 2016. The clinical features of the MM patients are summarized. Real-time quantitative PCR was performed to analyze the relative expression levels of the SNHG18 and SEMA5Agenes. The clinical characteristics and overall survival (OS) of the MM patients were statistically analyzed while measuring different levels of SNHG18 and SEMA5Agene expression. At the same time, the correlation between the expression of SNHG18 and SEMA5A was also analyzed. RESULTS: The analysis confirmed that SNHG18 and its possible target gene SEMA5A were both highly expressed in newly diagnosed MM patients. After analyzing the clinical significance of SNHG18 and SEMA5A in MM patients, we found that the expression of SNHG18 and SEMA5A was related to the Durie-Salmon (DS), International Staging System (ISS), and Revised International Staging System (R-ISS) classification systems, and the Mayo Clinic Risk Stratification for Multiple Myeloma (mSMART; p < 0.05). Moreover, we observed a significant difference in OS between the SNHG18/SEMA5A high expression group and the low expression group. We found a positive correlation between SNHG18 and SEMA5A expression (r = 0.709, p < 0.01). Surprisingly, the expected median OS times of both the SNHG18 and SEMA5Ahigh expression groups were significantly decreased, which was in contrast to those of both the SNHG18 and SEMA5Alow expression groups and the single-gene high expression group (p < 0.05). CONCLUSION: High expression of both SNHG18 and SEMA5A is associated with poor prognosis in patients with MM.

12.
ACS Appl Mater Interfaces ; 11(43): 40916-40922, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31597426

RESUMO

The paper presents a methodology to control the motion and orientation of suspended reflective cholesteric flakes in a nematic liquid crystal (LC) matrix. The flakes exhibit a dielectric anisotropy which controls their alignment with their in-plane axes parallel to an external electrical dc field. The elastic forces imposed by the LC host affect the switching behavior of the flakes and take care of the realignment to the planar state as soon as the dc field is switched off. When the LC host has a positive dielectric anisotropy, the switching voltage of the flakes is reduced by a factor of 2 in comparison with a LC host with negative dielectric anisotropy or in comparison with an isotropic host. We discovered that the LC host further regulates the back relaxation of cholesteric to return to the planar state upon retrieving the electric field. Whereas, in the isotropic fluid, flakes do not exhibit a preferred orientation when relaxed. Based on this newly proposed principle, we demonstrated its application as an optical switch for smart windows. Depending on the pitch of the cholesteric helix of the flakes, the light of a preset wavelength is reflected. Upon application of an electric field, the embedded flakes rotate their planes perpendicular to the substrate and consequently the incident light becomes fully transmitted without reflection or scattering of light.

13.
Ann Transl Med ; 7(14): 331, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31475201

RESUMO

Background: To ascertain whether concurrent chemotherapy using liposomal paclitaxel and cisplatin could improve the outcomes of patients with locally advanced esophageal squamous cell carcinoma receiving intensity-modulated radiotherapy (IMRT). Methods: A total of 72 patients with locally advanced esophageal squamous cell carcinoma, which were admitted to our hospital from October 2011 to December 2013, were retrospectively analyzed in this study. Results: Thirty-six patients (50%) were treated with IMRT alone, while the other 36 patients (50%) were treated by IMRT combined with chemotherapy containing liposomal paclitaxel and cisplatin. Patients treated with chemoradiotherapy showed significantly superior overall survival (OS) and progression-free survival (PFS) compared to patients treated with IMRT alone (median OS: respectively, 29.7 vs. 12.9 months, P=0.0287; median PFS: respectively, 14.0 vs. 6.5 months, P=0.0186). Multivariate Cox analysis confirmed the inclusion of chemotherapy as an independent predictor of favorable OS and PFS. Both chemoradiotherapy and IMRT were well-tolerated in our cohort. Conclusions: Chemotherapy improved the prognosis of locally advanced esophageal squamous cell carcinoma treated with IMRT. Large prospective studies are needed to confirm the therapeutic value of IMRT combined with chemotherapy in locally advanced esophageal squamous cell carcinoma.

14.
Int J Mol Sci ; 20(17)2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31480549

RESUMO

Normal mammalian palatogenesis is a complex process that requires the occurrence of a tightly regulated series of specific and sequentially regulated cellular events. Cleft lip/palate (CLP), the most frequent craniofacial malformation birth defects, may occur if any of these events undergo abnormal interference. Such defects not only affect the patients, but also pose a financial risk for the families. In our recent study, the miniature pig was shown to be a valuable alternative large animal model for exploring human palate development by histology. However, few reports exist in the literature to document gene expression and function during swine palatogenesis. To better understand the genetic regulation of palate development, an mRNA expression profiling analysis was performed on miniature pigs, Sus scrofa. Five key developmental stages of miniature pigs from embryonic days (E) 30-50 were selected for transcriptome sequencing. Gene expression profiles in different palate development stages of miniature pigs were identified. Nine hundred twenty significant differentially expressed genes were identified, and the functional characteristics of these genes were determined by gene ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Some of these genes were associated with HH (hedgehog), WNT (wingless-type mouse mammary tumor virus integration site family), and MAPK (mitogen-activated protein kinase) signaling, etc., which were shown in the literature to affect palate development, while some genes, such as HIP (hedgehog interacting protein), WNT16, MAPK10, and LAMC2 (laminin subunit gamma 2), were additions to the current understanding of palate development. The present study provided a comprehensive analysis for understanding the dynamic gene regulation during palate development and provided potential ideas and resources to further study normal palate development and the etiology of cleft palate.

15.
Ying Yong Sheng Tai Xue Bao ; 30(7): 2218-2230, 2019 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-31418224

RESUMO

Quercus mongolica and Phellodendron amurense are two important broad-leaved species in temperate forests of Northeast China. It is critical to explore their responses to climate change for supporting management, protection, and restoration of the broad-leaved forest in Northeast China under the future climate change scenario. Three sampling sites along a longitude gradient, Heilun, Tieli and Yichun, were set up in the Xiaoxing'an Mountains. Dendrochronological methods were used to establish standard chronologies for Q. mongolica and P. amurense. Correlation analyses were conducted between these chronologies and local climatic factors to establish the spatial and temporal variations in growth-climate relationship of Q. mongolica and P. amurense. The results showed that the radial growth of P. amurense was sensitive to temperature, while that of Q. mongolica was limi-ted by both temperature and precipitation. The temperature sensitivities of these two species were different. High spring temperature inhibited the radial growth of Q. mongolica, but promoted that of P. amurense. The limiting effect of high maximum temperature in summer on radial growth of Q. mongolica was significantly higher than that of P. amurense. With the increases of longitude (water availability), the correlation coefficients between radial growth of Q. mongolica and precipitation gradually weakened, while P. amurense didn't change. The physiological characteristics of those tree species was the key factors affecting their growth-climate relationship. With the significant warming since the 1976, the growth trend of P. amurense increased, whilst that of Q. mongolica decreased. Deteriorated drought stress caused by warming and difference in the species' ability to cope with water deficits might be the main reasons for different responses of two species, and for the divergence phenomenon occurring for Q. mongolica. If warming continues or worsens in the future, the growth of Q. mongolica may decline due to the intensified drought stress, while that of P. amurense may be less affected or be slightly enhanced.


Assuntos
Mudança Climática , Phellodendron/crescimento & desenvolvimento , Quercus/crescimento & desenvolvimento , China , Florestas , Árvores
16.
Physiol Rep ; 7(16)2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31448579

RESUMO

Elevated H2 O2 is implicated in many cardiovascular diseases. We previously demonstrated that H2 O2 -induced endothelial nitric oxide synthase (eNOS) activation and excessive NO production contribute to vascular cell injury and increases in microvessel permeability. However, the mechanisms of excessive NO-mediated vascular injury and hyperpermeability remain unknown. This study aims to examine the functional role of NO-derived peroxynitrite (ONOO- ) in H2 O2 -induced vascular barrier dysfunction by elucidating the interrelationships between H2 O2 -induced NO, superoxide, ONOO- , and changes in endothelial [Ca2+ ]i and microvessel permeability. Experiments were conducted on intact rat mesenteric venules. Microvessel permeability was determined by measuring hydraulic conductivity (Lp). Endothelial [Ca2+ ]i , NO, and O2 - were assessed with fluorescence imaging. Perfusion of vessels with H2 O2 (10 µmol/L) induced marked productions of NO and O2 - , resulting in extensive protein tyrosine nitration, a biomarker of ONOO- . The formation of ONOO- was abolished by inhibition of NOS with NG -Methyl-L-arginine. Blocking NO production or scavenging ONOO- by uric acid prevented H2 O2 -induced increases in endothelial [Ca2+ ]i and Lp. Additionally, the application of exogenous ONOO- to microvessels induced delayed and progressive increases in endothelial [Ca2+ ]i and microvessel Lp, a pattern similar to that observed in H2 O2 -perfused vessels. Importantly, ONOO- caused further activation of eNOS with amplified NO production. We conclude that the augmentation of NO-derived ONOO- is essential for H2 O2 -induced endothelial Ca2+ overload and progressively increased microvessel permeability, which is achieved by self-promoted amplifications of NO-dependent signaling cascades. This novel mechanism provides new insight into the reactive oxygen and/or reactive nitrogen species-mediated vascular dysfunction in cardiovascular diseases.

17.
Microb Pathog ; 136: 103687, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31442572

RESUMO

Mussels, randomly collected from fish markets in China, were analyzed by a semi-nested PCR to detect B1 gene of Toxoplasma gondii. Out of the 2215 samples, fifty-five (2.48%) were detected T. gondii-positive. The prevalence in Shandong province, Liaoning province and Zhejiang province were 2.51%, 2.26% and 2.69%, respectively. T. gondii oocysts were more frequently detected in digestive glands (1.04%) and haemolymph (1.49%) when compared with gills (0.23%). Of the 55 positive DNA, only two samples showed complete genotype at 11 locus and were authenticated as ToxoDB Genotype #9. To our knowledge, the present study is the first to confirm the presence of T. gondii in market-sold mussels in China. The findings point to the risk of humans acquiring T. gondii infection by consuming mussels bought in the aquatic product market.

18.
Environ Pollut ; 254(Pt B): 113042, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31454583

RESUMO

The bio-reduction of hexavalent chromium (Cr(VI)) by anaerobic fermentation is considered as a promising, low-cost and environment-friendly way. However, it is unclear for the reduction mechanisms of Cr(VI) in an anaerobic hydrogen fermenter, such as reduction kinetics, related electron donors, migration and transformation, reduction site and key components, and related microorganisms. To clarify these issues, a hydrogen fermenter was designed to reduce Cr(VI) at 55 °C with glucose as initial substrate. Results show that 100 mg/L Cr(VI) can be completely reduced (99.5%) to trivalent chromium (Cr(III) through chemical and biological reactions. Bio-reduction dominates Cr(VI) removal in a first-order exponential decay mode with both glucose and its metabolites (volatile fatty acids) as electron donors. Moreover, volatile fatty acids are more suitable as electron donors for Cr(VI) bio-reduction than glucose. Bacilli, Clostridia and Thermotogae in the fermenter dominated the reduction of Cr(VI) by regulating the production and composition of extracellular polymers (EPSs), in which carboxyl and hydroxyl groups play an important role for Cr(VI) reduction by coordination. The results can guide us to regulate the bio-reduction of Cr(VI), and provide reference for the development of bio-reduction technology of Cr(VI).


Assuntos
Cromo/metabolismo , Fermentação , Anaerobiose , Bactérias , Biodegradação Ambiental , Reatores Biológicos , Hidrogênio , Concentração de Íons de Hidrogênio , Cinética , Oxirredução
19.
J Mol Recognit ; 32(11): e2804, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31373076

RESUMO

Microplastic pollution attracted extensive attention because of its global presence and adverse effects on ecosystem. However, it is insufficient to clear the effects of nanoplastics on organisms at the molecular level. Herein, a nanopolystyrene (50 nm) was used to examine molecular responses of superoxide dismutase (SOD) and desoxyribonucleic acid (DNA) using spectroscopy (UV-vis, circular dichroism spectra, and fluorescence measurements) and single cell gel electrophoresis methods. Results showed that nanopolystyrene induced oxidative stress, involving in the increase of SOD activity and malondialdehide (MDA) content, and DNA damage because of the significant increase of olive tail moment, head optical density, and tail DNA percentage in the groups at exposure concentrations above 5 × 10-6  mol/L. The second structural and microenvironment of aromatic amino acids of SOD were changed with nanopolystyrene exposure. The fluorescence of SOD was quenched by nanopolystyrene at exposure concentration above 1 × 10-5  mol/L, and the quenching mode could be ascribed to the static type. The results and the combined methods are favorable to explore the molecular toxicity of other nanoplastics and the interaction mechanism.

20.
Micromachines (Basel) ; 10(7)2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31266204

RESUMO

Polymer cholesteric liquid crystal (PCLC) flakes are gaining increasing interest for a wide variety of applications because of their unique optical properties and capabilities. Soft lithography is the most effective way to fabricate regularly shaped PCLC flakes. However, it is not easy to peel the flakes from the mold without breaking them. In order to peel the PCLC flakes from the patterned polydimethylsiloxane (PDMS) mold in a convenient way, in this paper, a method of coating a layer of polyvinyl alcohol (PVA) on a PDMS mold was proposed. The influence of the thickness of the PVA layer on the shape of the PCLC flakes and the release time from the PDMS mold were investigated. The results show that the presence of the PVA layer can speed up the release of the PCLC flakes and help maintain the shape effectively. Notably, the utilization of a PVA layer makes the PDMS mold recyclable. The influence of PCLC flake shape was also studied. This work will promote the development of switchable PCLC flake-based technologies.

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