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1.
Nature ; 602(7896): 251-257, 2022 02.
Article in English | MEDLINE | ID: mdl-35140390

ABSTRACT

The development of high-performance ultraelastic metals with superb strength, a large elastic strain limit and temperature-insensitive elastic modulus (Elinvar effect) are important for various industrial applications, from actuators and medical devices to high-precision instruments1,2. The elastic strain limit of bulk crystalline metals is usually less than 1 per cent, owing to dislocation easy gliding. Shape memory alloys3-including gum metals4,5 and strain glass alloys6,7-may attain an elastic strain limit up to several per cent, although this is the result of pseudo-elasticity and is accompanied by large energy dissipation3. Recently, chemically complex alloys, such as 'high-entropy' alloys8, have attracted tremendous research interest owing to their promising properties9-15. In this work we report on a chemically complex alloy with a large atomic size misfit usually unaffordable in conventional alloys. The alloy exhibits a high elastic strain limit (approximately 2 per cent) and a very low internal friction (less than 2 × 10-4) at room temperature. More interestingly, this alloy exhibits an extraordinary Elinvar effect, maintaining near-constant elastic modulus between room temperature and 627 degrees Celsius (900 kelvin), which is, to our knowledge, unmatched by the existing alloys hitherto reported.

3.
Zhonghua Jie He He Hu Xi Za Zhi ; 46(9): 930-935, 2023 Sep 12.
Article in Zh | MEDLINE | ID: mdl-37670648

ABSTRACT

Optical coherence tomography (OCT) is a specialized optical imaging technique with a history of more than 30 years, known as'optical biopsy' because of its high resolution and high sensitivity. OCT has been used in the airway for more than 20 years, and researchers have explored and improved the imaging methods of OCT in the airway, focusing mainly on expanding the imaging site and enriching the imaging content. In terms of broadening the imaging site, it covers the airway from generation 0 to 9. In terms of enriching imaging content, additional assessment of airway wall blood vessels, airway smooth muscle, fibrous tissue, and airway compliance can be performed. It plays an important role in the study of various respiratory diseases. Therefore, this paper mainly summarized the exploration of the imaging site and content of airway OCT as follows.


Subject(s)
Muscle, Smooth , Tomography, Optical Coherence , Biopsy
4.
Zhonghua Jie He He Hu Xi Za Zhi ; 44(12): 1071-1077, 2021 Dec 12.
Article in Zh | MEDLINE | ID: mdl-34915620

ABSTRACT

Objective: To evaluate the effectiveness and safety of the robotic assisted bronchoscope system for localizing and removing the spring coils that placed in the peripheral lung of beagle dogs. Methods: The study was conducted from June 18th to June 20th, 2021. Metallic lung coils were placed as the simulated lesions to the periphery of the lungs of two adult male beagle dogs using a bronchoscope under general anesthesia. The navigation path was planned by the navigation function that built in the robotic bronchoscope system. After training, the doctors operated the robotic bronchoscope system to locate and remove the coils from the lung. The navigation success rate, sampling success rate, position of the coil, navigation time, sampling time, and operation time were evaluated. The damage to the airway mucosa during the operation and the vital signs of the beagles during and post-operation were accessed. Chest computerized tomography (CT) was performed post-operation to detect if there were complications such as pneumothorax and bleeding. Results: A total of 12 spring coils were successfully inserted into the two beagles. All the navigation paths of the simulated lesions were successfully planned. The navigation success rate was 12/12. The navigation time was (43.9±19.8) seconds. The distance between the tip of the flexible endoscope arm and the target point measured by the navigation system was (6.93±2.15) mm. The locations of the simulated lesions were distributed in the 6th-8th generation of bronchi. The sampling success rate was 12/12. The sampling time was (42.4±11.3) seconds. There was no pneumothorax or mediastinal emphysema after the placement of the coil. The vital signs of the beagle dogs were stable throughout the operation, and no operation-related or postoperative complications occurred. Conclusions: The robotic bronchoscope system can be used to locate and remove the spring coils from the peripheral lung of beagle dogs, and the procedure is simple and safe. It suggests that the robotic bronchoscopy system has great clinical significance in the sampling and diagnosis of peripheral lung lesions.


Subject(s)
Bronchoscopy , Robotic Surgical Procedures , Animals , Bronchoscopes , Dogs , Lung/diagnostic imaging , Lung/surgery , Male , Pilot Projects
5.
Colorectal Dis ; 21(2): 138-155, 2019 02.
Article in English | MEDLINE | ID: mdl-30428157

ABSTRACT

AIM: Perineal wound complications after abdominoperineal resection (APR) have become a major clinical challenge. Myocutaneous flap closure has been proposed in place of primary closure to improve wound healing. We conducted this comprehensive meta-analysis to evaluate the current scientific evidence of primary closure vs myocutaneous flap closure of perineal defects following APR for colorectal disease. METHODS: We systematically searched the MEDLINE, Embase, PubMed, Web of Science and Cochrane Library databases to identify all relevant studies. After data extraction from the included studies, meta-analysis was performed to compare perioperative outcomes of primary closure and myocutaneous flap closure. RESULTS: Eighteen studies with a total of 17 913 patients (16 346 primary closure vs 1567 myocutaneous flap closure) were included. We found that primary closure was significantly associated with higher total perineal wound complications (P = 0.007), major perineal wound complications (P < 0.001) and perineal wound infection (P = 0.001). On the other hand, myocutaneous flap closure takes more operation time (P < 0.001) and increases the risk of perineal wound dehiscence (P = 0.01), deep surgical site infection (P < 0.001), enterocutaneous fistulas (P = 0.03) and return to the operating room (P = 0.0005). There were no significant differences between the two groups for other outcomes. CONCLUSIONS: This is the first systematic review with meta-analysis comparing primary closure with myocutaneous flap closure of perineal defects after APR for colorectal disease. Although taking more operation time and an increased risk of specific complications, the pooled results have validated the use of myocutaneous flaps for reducing total/major perineal wound complications. More investigations are needed to draw definitive conclusions on this dilemma.


Subject(s)
Colorectal Surgery/methods , Myocutaneous Flap , Perineum/surgery , Plastic Surgery Procedures/methods , Postoperative Complications/surgery , Surgical Wound Dehiscence/surgery , Humans
7.
Reprod Domest Anim ; 52(6): 1081-1092, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28758253

ABSTRACT

Proper HOXA10 expression was essential for endometrial receptivity what was crucial for successful embryo implantation in mammalian. This study confirmed that miR-182 regulated the expression levels of HOXA10 by binding to its 3' UTR, selectively downregulated HOXA10 in goat endometrial epithelium cells (gEECs) but not stromal cell (gESCs) in vitro. However, HOXA10 and miR-182 both up-expressed in the goat endometrium at gestational day 15 (D15) compared with gestational day 5 (D5), suggesting that there were some other factors regulated the expression of HOXA10 during the development of goat endometrium in vivo. What's more, HOXA10 gene silencing (HOXA10-siRNA) resulted in gEECs apoptosis in vitro, and it regulated the protein levels of oestrogen receptor a (ERa), progesterone receptor B (PRb), insulin-like growth factor 1 receptor (IGF1R), BCL-2, pleiotrophin (PTN), AKT and p-JNK in gEECs. Furthermore, HOXA10 might regulate the protein levels of endometrial receptivity biomarker genes, including vascular endothelial growth factor (VEGF), osteopontin (OPN), cyclooxygenase-2 (COX-2) and prolactin receptor (PRLR) in gEECs. In conclusion, miR-182 targeted HOXA10 selectively in EECs in vitro, and HOXA10 played an important role in maintaining the function of EECs in dairy goats.


Subject(s)
Endometrium/metabolism , Goats/metabolism , Homeodomain Proteins/metabolism , MicroRNAs/physiology , 3' Untranslated Regions , Animals , Apoptosis , Cells, Cultured , Endometrium/cytology , Epithelial Cells/physiology , Female , Gene Expression Regulation , Goats/genetics , Intercellular Signaling Peptides and Proteins/genetics , RNA, Small Interfering , Stromal Cells/physiology
8.
Zhonghua Jie He He Hu Xi Za Zhi ; 40(7): 499-503, 2017 Jul 12.
Article in Zh | MEDLINE | ID: mdl-28728273

ABSTRACT

Objective: To evaluate the safety of the procedures of whole lung lavage(WLL) for pulmonary alveolar proteinosis(PAP) in perioperative period. Methods: In this retrospective study, we collected clinical data from 78 WLL procedures of PAP patients from January 2006 to June 2016 in Guangzhou Institute of Respiratory Disease. The causes of perioperative complications were analyzed. Results: Eighteen (23.07%) of the 78 procedures developed complications, including pleural effusion(n=4), pneumonia(n=4), cardiac failure(n=2), cardiac arrhythmia (n=2), pneumothorax(n=2), atelectasis(n=1), lung edema(n=1), laryngeal edema(n=1), pleural effusion and pneumonia(n=1). All complications were mild and easy to treat. Seventy-four procedures had successful extubation, but 4 procedures developed a prolonged time of extubation. Age, DSS, PaCO(2,)FEV(1,)lavage volume, lavage times and underlying diseases were not predictors for any complications(each P>0.05). High fluid recovering rate had a protective effect against the occurring of complications (Wald=7.672, OR<0.01, P<0.05). Conclusions: Whole lung lavage was a safe procedure in the treatment of PAP. Complications could recovery after proper therapy. The perioperative complications showed a correlation with low fluid recover rate. Operation under guideline was the key to avoid complications.


Subject(s)
Bronchoalveolar Lavage/methods , Lung/pathology , Pulmonary Alveolar Proteinosis/therapy , Bronchoalveolar Lavage/statistics & numerical data , Bronchoalveolar Lavage Fluid , Humans , Lung/metabolism , Pneumothorax , Pulmonary Alveolar Proteinosis/epidemiology , Pulmonary Alveolar Proteinosis/metabolism , Respiratory Function Tests , Retrospective Studies
11.
Planta ; 238(5): 969-82, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23975011

ABSTRACT

The development and regulation of aerenchyma in waterlogged conditions were studied in the seminal roots of wheat. Evans blue staining and the first cell death position indicated that the cortical cell death began at the root mid-cortex cells in flooding conditions. Continuous waterlogging treatment caused the spread of cell death from the mid-cortex to the neighboring cells and well-developed aerenchyma was formed after 72 h. Meanwhile, the formation of radial oxygen loss barrier was observed in the exodermis owing to the induction of Casparian bands and lignin deposition. Analysis of aerenchyma along the wheat root revealed that aerenchyma formed at 10 mm from the root tip, significantly increased toward the center of the roots, and decreased toward the basal region of the root. In situ detection of radial oxygen species (ROS) showed that ROS accumulation started in the mid-cortex cells, where cell death began indicating that cell death was probably accompanied by ROS production. Further waterlogging treatments resulted in the accumulation of ROS in the cortical cells, which were the zone for aerenchyma development. Accumulation and distribution of H2O2 at the subcellular level were revealed by ultracytochemical localization, which further verified the involvement of ROS in the cortical cell death process (i.e., aerenchyma formation). Furthermore, gene expression analysis indicated that ROS production might be the result of up-regulation of genes encoding for ROS-producing enzymes and the down-regulation of genes encoding for ROS-detoxifying enzymes. These results suggest that aerenchyma development in wheat roots starts in the mid-cortex cells and its formation is regulated by ROS.


Subject(s)
Plant Roots/cytology , Plant Roots/metabolism , Reactive Oxygen Species/metabolism , Triticum/cytology , Triticum/metabolism , Water/pharmacology , Gene Expression Regulation, Plant/drug effects , Genes, Plant/genetics , Homeostasis/drug effects , Homeostasis/genetics , Meristem/cytology , Meristem/metabolism , Models, Biological , Plant Roots/drug effects , Plant Roots/ultrastructure , Seedlings/drug effects , Seedlings/growth & development , Triticum/genetics , Triticum/ultrastructure
12.
Acta Biol Hung ; 64(3): 328-40, 2013 Sep.
Article in English | MEDLINE | ID: mdl-24013894

ABSTRACT

This research was aimed to study the cell wall degradation and the dynamic changes of Ca2+ and related enzymes in developing aerenchyma of wheat root under waterlogging. An examination of morphological development by light and electron microscope revealed that the structure of cell wall in middle cortical cells remained intact after 12 h of waterlogging and turned thinner after waterlogging for 24 h. At 48 h, the aerenchyma has been formed. The cellulase activity gradually increased in middle cortical cells within 24 h of waterlogging, and decreased with the formation of aerenchyma. Fluorescence detection and subcellular localization of Ca2+ showed the dynamic changing of Ca2+ at the cellular and subcellular levels during the development of aerenchyma. The activity of Ca2+-ATPase enhanced markedly in intercellular space, plasma membrane and tonoplast of some middle cortical cells after 8 h of waterlogging and remained high after 24 h, but it decreased after 48 h of waterlogging. All these suggests that cellulase, Ca2+ and Ca2+-ATPase show a dynamic distribution during the aerenchyma development which associated with the cell wall degradation of middle cortical cells. Moreover, there is a feedback regulation between Ca2+ and Ca2+-ATPase.


Subject(s)
Calcium/metabolism , Cell Wall/metabolism , Plant Roots/enzymology , Triticum/enzymology , Water/physiology , Calcium-Transporting ATPases/metabolism , Cellulase/metabolism , Plant Roots/growth & development , Plant Roots/ultrastructure , Triticum/growth & development , Triticum/ultrastructure
13.
Plant Dis ; 96(4): 486-496, 2012 Apr.
Article in English | MEDLINE | ID: mdl-30727432

ABSTRACT

Apple ring rot and Botryosphaeria canker are severe diseases affecting apple production in China, but there is confusion regarding which pathogens cause these diseases and their similarity to other diseases, such as white rot of apple, and ring rot and Botryosphaeria canker of pear. In this study, the pathogen of apple ring rot in China was compared with the pathogen of apple ring rot in Japan and Korea, the pathogen of Botryosphaeria canker of apple and pear in China, the pathogen of pear ring rot in China, and the pathogen of white rot of apple in the United States. Comparisons were based on morphology, pathogenicity on branches and fruit, and sequences of rDNA in the internal transcribed spacer region and of the ß-tubulin and actin genes. Results showed that the causal agent of apple ring rot and Botryosphaeria canker of apple in China was Botryosphaeria dothidea, which has also been reported to be the pathogen of apple ring rot in Korea and Japan. Pathogenicity tests showed that B. dothidea infection on apple and pear branches may induce wart or canker symptoms depending on the conditions. These results are consistent with the hypothesis that the same pathogen causes the wart symptom of apple ring rot and the Botryosphaeria canker symptom on apple branches in China. The results also suggest that apple ring rot and white rot are the same disease and are caused by B. dothidea. Finally, B. dothidea isolates from pear and other fruit or forest trees may serve as inoculum for apple ring rot.

14.
Eur Rev Med Pharmacol Sci ; 26(20): 7349-7358, 2022 10.
Article in English | MEDLINE | ID: mdl-36314305

ABSTRACT

OBJECTIVE: In order to solve the problem of image real-time processing and correction for high-speed endoscopic swept-source optical coherence tomography (SS-OCT), we highly optimize a computer-unified device architecture-based platform and use a field-programmable gate array to summarize the application experience. MATERIALS AND METHODS: We use the Half-Sync/Half-Asyn mode to optimize memory in order to build a high-throughput data thread pool for CPU. We use asynchronous streaming architecture to multiplex multiple threads at high speed to accelerate data processing. At the same time, we design a rotary scanning position information encoding feedback module to suppress image drift, which can realize 25ns logic-timing sequence synchronization control through FPGA 40MHz clock. RESULTS: The maximum complete attainable axial-scan-processing rate (including memory transfer and display of B-scan frames) is 3.52 MHz for a 16-bit pixel depth and A-scans/s of 1024 pixels. To our knowledge, this is the fastest processing rate reported to date with a single-chip graphical processing unit for SS-OCT. Finally, the established high-speed SS-OCT is used to image mouse esophagus and human fingers, and the output images are stable. When the image size is 1024 × 1024 pixels, the real-time imaging rate is 200 frames per second. CONCLUSIONS: This paper develops a real-time image processing and reconstruction technology suitable for high-throughput SS-OCT systems, which can have high-density operation and efficient parallelism, while suppressing high-speed image drift. It lays the foundation for the non-destructive, in vivo, non-staining, fast and convenient early tumor diagnosis of high-speed endoscopic SS-OCT.


Subject(s)
Image Processing, Computer-Assisted , Tomography, Optical Coherence , Animals , Mice , Humans , Tomography, Optical Coherence/methods , Software , Acceleration
15.
Zhonghua Wei Chang Wai Ke Za Zhi ; 23(5): 480-485, 2020 May 25.
Article in Zh | MEDLINE | ID: mdl-32842428

ABSTRACT

Objective: To identify the factors associated with successful transrectal specimen extraction after laparoscopic rectal cancer resection. Methods: A retrospective case-control study was conducted. Clinical data of rectal cancer patients who did or did not successfully undergo transrectal specimen extraction in Shanghai East Hospital between January 2017 and December 2017 were retrieved through the rectal cancer database of Shanghai East Hospital. Case inclusion criteria: (1) tumor size ≤7 cm by pelvic MRI; (2) body mass index (BMI)≤ 30 kg/m(2); (3) no history of neoadjuvant chemoradiotherapy; (4) no anal stenosis. Clinical data including age, gender, BMI, tumor obstruction, distance from tumor to anal verge, history of abdominal operation, maximal diameter of tumor and width of mesorectum in the anteroposterior dimension measured by pelvic MRI, etc. were collected. The χ(2) test was used to perform univariate analysis. Multivariate logistic regression was used to identify factors affecting transrectal specimen extraction. Results: A total of 208 patients were included in the analysis. Of 208 patients, 132 were men and 76 were women; mean age was (63±11) years old and median tumor size was 3.8 (IQR, 3.0 to 5.0) cm. Sixty-six (31.7%) patients completed transrectal specimen extraction successfully. Univariate analysis showed that patients who completed transrectal specimen extraction were more likely to have a lower BMI (χ(2)=7.420, P=0.006), be free from malignant obstruction (χ(2)=8.972, P=0.003), have a shorter distance from tumor to the anal verge (<5.0 cm) (χ(2)=14.960, P<0.001), a smaller tumor size (≤5.0 cm) (χ(2)=18.495, P<0.001) and a thinner mesorectum in the anteroposterior dimension (≤6.0 cm) (χ(2)=34.612, P<0.001) than those who failed to perform transrectal specimen extraction. Gender, age or history of abdominal operation were not associated with the successful extraction (all P>0.05). Multivariate analysis revealed that BMI ≤25.0 kg/m(2) (OR=2.32, 95% CI: 1.06 to 5.06, P=0.034), free from malignant obstruction (OR=3.01, 95% CI: 1.82 to 6.69, P<0.001), the distance from tumor to the anal verge <5.0 cm (OR=3.73, 95% CI: 1.22 to 11.43, P=0.021), tumor size ≤ 5.0 cm (OR=4.43, 95% CI: 1.39 to 14.09, P=0.012), and the anteroposterior width of mesorectum ≤ 6.0 cm (OR=4.30, 95% CI: 2.02 to 9.18, P<0.001) were independent protective factors for successful transrectal specimen extraction. Conclusion: Preoperative assessment of BMI, malignant obstruction, distance from tumor to the anal verge, tumor size and anteroposterior width of mesorectum is beneficial to choose appropriate patients with rectal cancer to undergo transrectal specimen extraction.


Subject(s)
Natural Orifice Endoscopic Surgery , Proctectomy/methods , Rectal Neoplasms/surgery , Rectum/surgery , Aged , Case-Control Studies , China , Female , Humans , Male , Middle Aged , Proctoscopy , Retrospective Studies , Risk Factors , Treatment Outcome
16.
Trends Cell Biol ; 11(11): S10-4, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11684436

ABSTRACT

Members of the Myc family of transcription factors are key regulators of cell proliferation, and excessive levels of Myc lead to tumor formation. Mad family proteins are related to Myc, but they antagonize the oncogenic activity of Myc in cell-culture assays. Here, we examine current models of Mad function and the relationship between Mad and Myc in cell proliferation, differentiation and tumorigenesis.


Subject(s)
Cell Differentiation/physiology , Cell Division/physiology , DNA-Binding Proteins/metabolism , Proto-Oncogene Proteins c-myc/metabolism , Repressor Proteins , Animals , Apoptosis/physiology , Basic Helix-Loop-Helix Leucine Zipper Transcription Factors , DNA/metabolism , Models, Biological
17.
Biol Trace Elem Res ; 183(2): 254-260, 2018 Jun.
Article in English | MEDLINE | ID: mdl-28815405

ABSTRACT

Trace amounts of selenium (Se) are essential for several organisms, and deficiencies therein have adverse effects on growth, development, and reproduction; this is particularly significant in animals raised for milk and livestock production. To study the effect of Se on Guanzhong dairy goats, their diets were supplemented with different sources (inorganic or organic) and Se concentrations (0.2 or 0.4 mg Se/kg). A non-Se-fortified basal diet served as a negative control, and a sixth treatment group received both inorganic and organic Se sources (0.2 mg Se/kg diet each). Dietary Se supplementation increased milk production, with organic Se being more effective than inorganic Se. Selenium supplementation also increased Se concentration and glutathione peroxidase activity in whole blood, with organic Se more effective than inorganic Se at the same Se concentration. With increasing Se in diets, the Se content in milk increased markedly, reaching a plateau value at day 30 in all groups, and organic Se (0.4 mg/kg diet) had the best effect. In addition, dietary Se sources and concentrations markedly affected Se concentrations in different tissues and organs. Thus, organic Se supplementation of a basal diet at 0.4 mg/kg is practically applicable for Se-enriched milk and meat production in Guanzhong dairy goats.


Subject(s)
Lactation/drug effects , Milk/chemistry , Selenium/pharmacology , Animal Feed , Animals , Dietary Supplements , Goats
18.
Mol Cell Biol ; 16(11): 6553-62, 1996 Nov.
Article in English | MEDLINE | ID: mdl-8887684

ABSTRACT

ERCC4 is an essential human gene in the nucleotide excision repair (NER) pathway, which is responsible for removing UV-C photoproducts and bulky adducts from DNA. Among the NER genes, ERCC4 and ERCC1 are also uniquely involved in removing DNA interstrand cross-linking damage. The ERCC1-ERCC4 heterodimer, like the homologous Rad10-Rad1 complex, was recently found to possess an endonucleolytic activity that incises on the 5' side of damage. The ERCC4 gene, assigned to chromosome 16p13.1-p13.2, was previously isolated by using a chromosome 16 cosmid library. It corrects the defect in Chinese hamster ovary (CHO) mutants of NER complementation group 4 and is implicated in complementation group F of the human disorder xeroderma pigmentosum. We describe the ERCC4 gene structure and functional cDNA sequence encoding a 916-amino-acid protein (104 kDa), which has substantial homology with the eukaryotic DNA repair and recombination proteins MEI-9 (Drosophila melanogaster), Rad16 (Schizosaccharomyces pombe), and Rad1 (Saccharomyces cerevisiae). ERCC4 cDNA efficiently corrected mutants in rodent NER complementation groups 4 and 11, showing the equivalence of these groups, and ERCC4 protein levels were reduced in mutants of both groups. In cells of an XP-F patient, the ERCC4 protein level was reduced to less than 5%, consistent with XPF being the ERCC4 gene. The considerable identity (40%) between ERCC4 and MEI-9 suggests a possible involvement of ERCC4 in meiosis. In baboon tissues, ERCC4 was expressed weakly and was not significantly higher in testis than in nonmeiotic tissues.


Subject(s)
DNA Repair , DNA-Binding Proteins/biosynthesis , DNA-Binding Proteins/genetics , Drosophila Proteins , Nuclear Proteins , Recombination, Genetic , Amino Acid Sequence , Animals , Base Sequence , CHO Cells , Cell Survival/radiation effects , Cloning, Molecular , Cosmids , Cricetinae , DNA Damage , DNA Repair Enzymes , DNA-Binding Proteins/chemistry , Drosophila melanogaster/genetics , Endonucleases/chemistry , Exons , Fungal Proteins/chemistry , Humans , Introns , Molecular Sequence Data , Open Reading Frames , Papio , Proteins/chemistry , Recombinant Proteins/biosynthesis , Restriction Mapping , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae Proteins , Schizosaccharomyces/genetics , Schizosaccharomyces pombe Proteins , Sequence Homology, Amino Acid , Transfection , Ultraviolet Rays
20.
J Physiol Pharmacol ; 68(4): 619-628, 2017 Aug.
Article in English | MEDLINE | ID: mdl-29151079

ABSTRACT

Euphorbia humifusa Willd. (EH), rich in flavonoids, has long been used for the treatment of bacillary dysentery and enteritis in China, and is known to have antioxidant, hypotensive and hypolipidemic properties. However, the vasorelaxant effect of total flavonoids of EH (TFEH) and action mechanisms are not clearly defined yet. The aim of the present study was to investigate the effects of TFEH on the vascular tension and its underlying mechanisms. Experiments were performed in rat thoracic aorta using the organ bath system. TFEH (0.01 - 100 µg/ml) caused a concentration-dependent vasorelaxation, which was dependent on a functional endothelium, and were significantly attenuated by inhibitors of endothelial NO synthase, its upstream signaling pathway, PI3K/Akt, and soluble guanylate cyclase, but not by blockade of KCa channel, KATP channel, cyclooxygenase, muscarinic and ß-adrenergic receptors. Extracellular Ca2+ depletion, and pre-treatment with modulators of the store-operated Ca2+ entry channels, Gd3+ and 2-aminoethyl diphenylborinate, significantly attenuated the TFEH-induced vasorelaxation. Our findings suggest that TFEH elicit vasorelaxation via endothelium-dependent NO-cGMP pathway through activation of PI3K/Akt- and Ca2+-eNOS-NO signaling. Further, it is suggested that TFEH-induced activation of the NO-soluble guanylate cyclase-cGMP-protein kinase G signaling relaxes vascular smooth muscle cells through an inhibition of the L-type Ca2+ channel activity.


Subject(s)
Aorta, Thoracic/drug effects , Euphorbia/chemistry , Flavonoids/pharmacology , Vasodilation/drug effects , Vasodilator Agents/pharmacology , Animals , Aorta, Thoracic/metabolism , Calcium/metabolism , Calcium Channels/metabolism , Cyclic GMP/metabolism , Drugs, Chinese Herbal/pharmacology , Endothelium, Vascular/drug effects , Endothelium, Vascular/metabolism , Nitric Oxide/metabolism , Nitric Oxide Synthase Type III/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Plant Extracts/pharmacology , Prostaglandin-Endoperoxide Synthases/metabolism , Rats , Rats, Sprague-Dawley , Signal Transduction/drug effects , Soluble Guanylyl Cyclase/metabolism
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