[The role of ROS/TXNIP/NLRP3 pathway in the skin injury of trichloroethylene sensitized mice]

Objective: To explore the mechanism of reactive oxygen species/thioredoxin-interacting protein/nucleotide-binding oligomerization domain-like receptor 3 (ROS/TXNIP/NLRP3) pathway in the skin injury of trichloroethylene (TCE) sensitized mice. Methods: In August 2020, 40 female BALB/c mice were randomly divided into control group (n=5) , solvent control group (n=5) , TCE treatment group (n=15) and TCE+(2-(2, 2, 6, 6-Tetrameyhylpiperidin-1-oxyl-4-ylamino)-2-oxoethyl) triphenylphosphonium chloride (Mito TEMPO) treatment group (n=15) . The TCE sensitization model was established. Mice in the TCE treatment group and TCE+Mito TEMPO treatment group were divided into the sensitized positive group and the sensitized negative group according to the skin erythema and edema reactions on the back of the mice 24 h after the last stimulation. The mice were sacrificed 72 h after the last stimulation, the back skin of the mice was taken, and the skin lesions were observed. Immunohistochemistry (IHC) was used to detect the expression level of NLRP3, and the Western Blot was performed to detect the expression levels of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC) , cysteinyl aspartate specific proteinase 1 (Caspase 1) , Interleukin-1β (IL-1β) and TXNIP proteins in the skin of the mice, the reactive oxygen species (ROS) kit was used to detect the level of intracellular ROS in the back skin tissue. Results: The sensitization rates of TCE treatment group and TCE+Mito TEMPO treatment group were 40.0% (6/15) and 33.3% (5/15) , respectively, and there was no significant difference between the two groups (P>0.05) . The back skin of the mice in the TCE sensitized positive group was thickened and infiltrated by a large number of inflammatory cells. The number of mitochondria in the epidermis cells was significantly reduced, the mitochondrial crest disappeared and vacuolar degeneration occurred. TCE+Mito TEMPO sensitized positive group had less damage, more mitochondria and relatively normal cell structure. Compared with the solvent control group and corresponding sensitized negative groups, the expression levels of NLRP3, ASC, Caspase 1, IL-1β, TXNIP proteins and the content of ROS in the TCE sensitized positive group and TCE+Mito TEMPO sensitized positive group were significantly increased (P<0.05) . Compared with TCE sensitized positive group, the expression levels of NLRP3, ASC, Caspase 1, IL-1β, TXNIP proteins and the content of ROS in the TCE+Mito TEMPO sensitized positive group were significantly decreased (P<0.05) . Conclusion: ROS/TXNIP/NLRP3 pathway was activated and then encouraged the release of IL-1β, finally aggravated the TCE-induced skin injury.

Comparison of Modified Above-Knee and Conventional Surgery with the Stripping of the Great Saphenous Vein of Varicose Veins of the Lower Extremities: A Retrospective Study

OBJECTIVE

To compare the clinical effects of modified above-knee and conventional surgery with the stripping of the great saphenous vein of varicose veins of the lower extremities.

METHODS

Clinical data of patients with a varicose vein of the lower extremity from May 2016 to May 2018 were collected. A retrospective study was conducted on the patients receiving modified above-knee and conventional surgery with the great saphenous vein stripping. The baseline characteristics and long-term follow-up data were compared between the groups.

RESULTS

There were no significant differences in baseline characteristics between the two groups (P > 0.05). The surgeries were successfully performed by the same group of surgeons under local anesthesia and neuraxial anesthesia. The hospital stay, operation time, intraoperative blood loss, total length, and number of incisions in the above-knee group were comparable to those in the conventional surgery group (P > 0.05). The incidence of saphenous nerve injury and subcutaneous hematoma in the above-knee group was lower than that in the conventional surgery group (P < 0.05). There were no significant differences in recurrent varicose vein incidences (P > 0.05). After surgery, the venous clinical severity score (VCSS) and chronic venous insufficiency questionnaire (CIVIQ-14) scores of both groups were higher than those before operation (P < 0.05). There was no significant difference in VCSS score or CIVIQ-14 scores between the two groups postoperation (P > 0.05). At 24 months after surgery, the above-knee group (71.8%) and conventional surgery group (73.2%) resulted in changes of at least two CEAP-C clinical classes lower than baseline, respectively.

CONCLUSION

The modified above-knee technique can ensure clinical outcomes, reduce intraoperative blood loss and complication incidences, and shorten the operative time. This gives evidence that the modified above-knee technique is worthy of clinical application.

Two New Methods of Supine Venographically Guided Popliteal Vein Puncture: A Retrospective Study

OBJECTIVE

Presently, the prone position is necessary for popliteal vein puncture access, but it makes the patients uncomfortable and does not allow traditional femoral or jugular access. To address these deficiencies, this study introduces two new methods, anterior and medial access carried out in the supine position.

METHODS

Venous interventions with punctures in the popliteal vein of 120 limbs in 97 patients were performed during the period from February 2017 to April 2019. After puncture, venographic guidance was achieved by dorsal vein injection of contrast medium. Interventional therapy was performed after puncture and insertion of the introducer sheath.

RESULTS

In all, 120 limbs were punctured in the popliteal vein, with technical success in 118 (98.3% in total) cases: 100%, 96.1%, and 100% successful punctures in, respectively, 32 anterior, 49 medial, and 37 posterior access cases. A comparison of the three groups revealed that the fluoroscopy time and duration of puncture were longer in the medial and anterior access groups than in the posterior access group. The rate of intra-operative and post-operative complications was 7.5% (9/120), with no statistically significant difference between the three access groups. Compared with the pre-operative median score of 2.5, the post-operative SVS (Society of Vascular Surgery) score of the popliteal vein was reduced to 1.5 in the anterior and 0.5 in the medial groups.

CONCLUSION

Medial and anterior puncture of the popliteal vein in the supine position can be used as a safe alternative in venous endovascular therapy. The two new methods can mitigate frailty or respiratory problems resulting from the prone position and facilitate traditional femoral and jugular access.

Application of computed tomography venography in the diagnosis and severity assessment of iliac vein compression syndrome: A retrospective study

The objectives are to evaluate the application of computed tomography venography (CTV) in the diagnosis of iliac vein compression syndrome (IVCS), and to assess the factors related to the incidence and development of IVCS and the recurrence of varicose veins.Imaging data of 120 patients with chronic venous disease (CVD) of the lower extremity and 68 subjects without CVD (control) were retrospectively reviewed by radiologists blinded to the groups. CTV, conventional venography, and Doppler ultrasound were compared in the diagnosis and contributing factors for IVCS were also analyzed.CTV required less procedure time than venography or color ultrasonography (P < .001). The rate of iliac venous compression diagnosed by CTV was higher in the CVD group (53.3%) than in the control group (22.1%) (χ = 17.425, P < .001). Risk factors for IVCS included gender, hyperlipidemia, and course of disease (P < .05). Development of femoral vein collateral was more common in patients with IVCS (P < .05). The duration of disease was positively associated with the severity of iliac vein compression (r = 0.321, P < .001). IVCS was an important contributing factor for varicose vein recurrence (51.2%). In patients with IVCS and venous ulcer (C5-C6), the healing time of the ulcer treated with stent was significantly shorter compared with those without stent treatment (P < .001).CTV is accurate for the diagnosis and severity evaluation of IVCS. IVCS might be a contributing factor for varicose vein recurrence. Iliac vein stent implantation as a safe and effective interventional therapy promotes the healing of venous ulcer caused by IVCS.

MicroRNA‑26a protects vascular smooth muscle cells against H2O2‑induced injury through activation of the PTEN/AKT/mTOR pathway

Abdominal aortic aneurysm (AAA) is a common disease, which is characterized by the apoptosis of vascular smooth muscle cells (VSMCs). In previous years, microRNAs (miRNAs) have been associated with AAA and functionally implicated in the pathogenesis of this disease. However, the role of miRNAs in the apoptosis of VSMCs remains to be fully elucidated. The present study aimed to elucidate the role and mechanism of miRNAs in protecting against hydrogen peroxide (H₂O₂)-induced apoptosis in VSMCs. The expression of miRNAs in peripheral blood from patients diagnosed with AAA was analyzed using a microarray and reverse transcription polymerase chain reaction. A VSMC injury model induced by H₂O₂ was used to determine the potential role of miR-26a against cell injury. Cell viability, cell apoptosis and reactive oxygen species (ROS) generation were determined by a CCK8 assay, flow cytometry and a 2′,7′-DCF diacetate assay, respectively. It was observed that miRNA (miR)-26a (miR-26a-1-5p) was significantly downregulated in peripheral blood samples from patients with AAA. It was revealed that H₂O₂ treatment dose-dependently inhibited cell viability, enhanced apoptosis and induced the production of ROS, which indicated the success of the model establishment. It was also observed that miR-26a was downregulated in the VSMCs following H₂O₂ stimulation. The upregulation of miR-26a attenuated H₂O₂-induced cell injury, as evidenced by the enhancement of cell viability, and inhibition of the activity of caspase-3, apoptosis and ROS production. In addition, phosphatase and tensin homolog (PTEN), a well-known regulator of the AKT/mammalian target of rapamycin (mTOR) pathway, was found to be a direct target of miR-26a in the VSMCs and this was validated using a luciferase reporter assay. Overexpression of PTEN by pcDNA-PTEN plasmids markedly eliminated the protective effects of the overexpression of miR-26a on H₂O₂-induced cell injury. Finally, it was found that miR-26a mediated its anti-apoptotic action by reactivation of the AKT/mTOR pathway, as demonstrated by the upregulation of phosphorylated (p-)AKT and p-mTOR, and the Akt inhibitor API-2 reversing the protective effects on VSMCs mediated by miR-26a. These results indicated that miR-26a protected VSMCs against H₂O₂-induced injury through activation of the PTEN/AKT/mTOR pathway, and miR-26a may be considered as a potential prognostic biomarker and therapeutic target in the treatment of AAA.

[Interferon-β combined with all-trans retinoic acid supresses proliferation and promote apoptosis by inhibiting JAK2/STAT3 pathway in HepG2 human hepatocellular carcinoma cells]

Objective To investigate the effect of interferon-β (IFN-β) combined with all-trans retinoic acid (ATRA) on the proliferation and apoptosis of HepG2 human hepatocarcinoma cells and the role of Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signal pathway in the process. Methods HepG2 cells were randomly divided intro three groups and treated with 1000 U/mL IFN-β, 10 μmol/L ATRA and 1000 U/mL IFN-β combined with 10 μmol/L ATRA, respectively for 24 hours. Cell viability was measured by MTT assay and apoptosis rate was detected by flow cytometry. Western blotting was applied to detect the protein levels of p-JAK2, p-STAT3, gene associated with retinoid-interferon-induced mortality-19 (GRIM-19), Bcl-2, Bcl-xl and Bax. Results IFN-β or ATRA inhibited the proliferation and induced the apoptosis of HepG2 cells. The effect was enhanced when IFN-β was combined with ATRA. The expressions of p-JAK2 and p-STAT3 were down-regulated while the expressions of GRIM-19 and Bax were up-regulated after treated with IFN-β or ATRA on HepG2 cells, especially the combination of IFN-β and ATRA. Conclusion Combination of IFN-β and ATRA could suppress the proliferation and induced the apoptosis of HepG2 hepatocarcinoma cells by inhibiting JAK2/STAT3 signal pathway.

Nanostructured SnO(2) films prepared from evaporated Sn and their application as gas sensors

This paper describes the morphology, stoichiometry, microstructure and gas sensing properties of nanoclustered SnO(x) thin films prepared by Sn evaporation followed by a rheotaxial growth and thermal oxidation process. Electron microscopy was used to investigate, in detail, the evolution of the films as the oxidation temperature was increased. The results showed that the contact angle, perpendicular height, volume and microstructure of the clusters all changed significantly as a result of the thermal oxidation processes. Electron diffraction and x-ray photoelectron spectroscopy measurements revealed that after oxidation at a temperature of 600 °C, the Sn clusters were fully transformed into porous three-dimensional polycrystalline SnO(2) clusters. On the basis of these results, a prototype SnO(2) sensor was fabricated and sensing measurements were performed with H(2) and NO(2) gases. At operating temperatures of 150-200 °C the film produced measurable responses to concentrations of H(2) as low as 600 ppm and NO(2) as low as 500 ppb.

The immunosuppressive and protective ability of glucose-regulated protein 78 for improvement of alloimmunity in beta cell transplantation

An insulinoma cell line, NIT-1, transfected with glucose-regulated protein 78 (GRP78) was established, namely NIT-GRP78, and used to study the immunosuppressive and protective ability of GRP78. In extended cytotoxic T lymphocyte (CTL) killing assay, NIT-1-primed lymphocytes were more cytotoxic in killing beta cells than NIT-GRP78-primed lymphocytes. Severe necrosis was observed only when the NIT-1-primed lymphocytes were cultured with NIT-1 beta cells, but not with NIT-GRP78 cells. In addition, an increase of interleukin (IL)-4 secretion from beta cell-primed splenocytes when GRP78 presence was observed in cytokine enzyme-linked immunosorbent assay (ELISA). Diabetic mice reached normoglycaemia promptly and gained weight after transplantation of either NIT-1 or NIT-GRP78 cells. However, the recipient mice transplanted with NIT-GRP78 cells lived much longer than those recipients transplanted with NIT-1 cells, which was due apparently to prolonged insulin production by the transplanted NIT-GRP78 cells. In fact, we observed a significant increase of insulin concentration after glucose stimulation of diabetic mice received NIT-GRP78 cells at day 7 post-transplantation. From the results we propose that GRP78 could have a dual function in both protecting NIT-1 cells from CTL-mediated lysis and stimulating a population of T helper 2 cells to down-regulate the immune response to the transplanted beta cells.

[Study on the surface hydroxyl species of diatomite using DRIFT spectroscopy]

Using DRIFT spectroscopy, we detected surface hydroxyl structure of diatomite in this study. There were either isolated hydroxyl groups or H-bonded hydroxyl groups on the surface of the diatomite. At room temperature, the diatomite surface was predominantly covered by weakly adsorbed water in cavity and water bonded to surface hydroxyl groups via H-bonds. There appeared a broad band with middle wavenumber at 3,400-3,500 cm-1 as a result in the corresponding DRIFT spectra. With driving off adsorbed water by heating the sample from 200 degrees C to 1000 degrees C, the broad band fade away gradually, and a single band at about 3,745 cm-1, which is attributed to both isolated hydroxyl groups and partial H-bonded hydroxyl groups, became more and more intense with increasing temperature. Under the heat treatment conditions of 1,100 degrees C for one hour, the isolated hydroxyl groups were mostly desorbed from the surface, and the H-bonded hydroxyl groups that existed above the inner wall of micropores with diameter of circa 10 nm, however, had not yet condensed thoroughly. The thermal behavior was supposed to be a speciality of diatomite.

Location and migration of cations in Cu(2+)-adsorbed montmorillonite

Locations of Cu2+ ion in Cu(2+)-adsorbed montmorillonite have been studied by electron paramagnetic resonance (EPR), supplemented by X-ray diffraction (XRD) and differential thermal analysis (DTA). In the EPR spectra of Cu(2+)-adsorbed montmorillonite, three signals, corresponding to Cu2+ ion, have been simultaneously recorded. Some Cu2+ ions seemed to replace the original interlayer metal cations and some entered into the hexagonal cavities. A small fraction of Cu2+ ions penetrated into the octahedral vacancies. There were two ways for the adsorption of Cu2+ ion by montmorillonite--exchangeable and specific. On heating, the hydrated Cu2+ ion in the interlayer loses the coordinating water and then enters into the hexagonal cavities. When the heating temperature further increased, dehydroxylation occurs, which facilitates Cu2+ ion in the hexagonal cavities to penetrate into the octahedral vacancies.

Structural examination of the influence of phosphorylation on the binding of fibrinopeptide A to bovine thrombin

Upon addition of thrombin, fibrinopeptides A and B are cleaved off from the N-termini of four chains of fibrinogen (Aalpha Bbeta gamma)2, and sites of polymerization are exposed, resulting in formation of a fibrin clot. For the fibrinogen Aalpha chain, cleavage occurs most prevalently at the Arg16-Gly17 peptide bond. About 25-30% of the human fibrinogen Aalpha chains are phosphorylated in nature at the position of Ser3, but the function for this modification is not understood. Previous NMR studies indicated that the N-terminal portion (1ADSGE5) of unphosphorylated fibrinopeptide A does not interact with the surface of bovine thrombin. Kinetic and NMR studies have now been carried out to assess whether phosphorylation at Ser3 allows the N-terminal segment (1ADSGEGDFLAEGGGVR16) to become anchored on the thrombin surface, leading to formation of a catalytically more efficient enzyme-substrate complex. Kinetic results indicate that phosphorylation leads to an approximately 65% increase in substrate specificity (kcat/Km) toward hydrolysis of fibrinogen Aalpha(1-20). 31P NMR studies reveal that the phosphorylated group does interact with thrombin, and 1H line broadening studies suggest that phosphorylation does promote binding of amino acids 1-5. Two-dimensional transferred nuclear Overhauser effect spectroscopy studies of bound fibrinopeptide A(1-16 Ser3P) indicate that phosphorylation allows new through-space interactions involving amino acid residues 1ADSGE5 to be observed. Computational docking of the peptide onto the X-ray structure of thrombin suggests that the phosphate may interact with basic residues at the rim of the heparin binding site of thrombin. As a result, the phosphate may serve as an anionic linker between the fibrinopeptide and the enzyme thrombin.

Major grass pollen allergen Lol p 1 binds to diesel exhaust particles: implications for asthma and air pollution

BACKGROUND

Grass pollen allergens are known to be present in the atmosphere in a range of particle sizes from whole pollen grains (approx. 20 to 55 microns in diameter) to smaller size fractions < 2.5 microns (fine particles, PM25). These latter particles are within the respirable range and include allergen-containing starch granules released from within the grains into the atmosphere when grass pollen ruptures in rainfall and are associated with epidemics of thunderstorm asthma during the grass pollen season. The question arises whether grass pollen allergens can interact with other sources of fine particles, particularly those present during episodes of air pollution.

OBJECTIVE

We propose the hypothesis that free grass pollen allergen molecules, derived from dead or burst grains and dispersed in microdroplets of water in aerosols, can bind to fine particles in polluted air.

METHODS

We used diesel exhaust carbon particles (DECP) derived from the exhaust of a stationary diesel engine, natural highly purified Lol p 1, immunogold labelling with specific monoclonal antibodies and a high voltage transmission electron-microscopic imaging technique.

RESULTS

DECP are visualized as small carbon spheres, each 30-60 nm in diameter, forming fractal aggregates about 1-2 microns in diameter. Here we test our hypothesis and show by in vitro experiments that the major grass pollen allergen, Lol p 1, binds to one defined class of fine particles, DECP.

CONCLUSION

DECP are in the respirable size range, can bind to the major grass pollen allergen Lol p 1 under in vitro conditions and represent a possible mechanism by which allergens can become concentrated in polluted air and thus trigger attacks of asthma.

Chemical Signature of the Superconducting Phase in the Nd-Ce-Cu-O System

The electron-doped material Nd2-xCexCuO(4) becomes superconducting with a Ce(4+) composition around 0.16, but only after removal of a minuscule amount of extraneous oxygen. This enigmatic behavior was addressed here. A small fraction of copper in the CuO(2) planes of Nd2-xCexCuO(4) was substituted by cobalt-57, which serves as a microprobe of the chemical environment. Deoxygenation brought about little change in the Mössbauer spectra both above and below the optimal superconducting concentration; however, for x = 0.16 a change was observed. In the latter, a major fraction of the magnetically split, five-coordinate species showed itself as a paramagnetically relaxed doublet upon deoxygenation. The abundance of the paramagnetically relaxed species corresponds closely to the diamagnetic volume fraction and thus provides a microscopic signature of the superconducting phase.

Direct Observation of Microscopic Inhomogeneities with Energy-Dispersive Diffraction of Synchrotron-Produced X-rays

Evidence of structural inhomogeneities in two high-transition-temperature superconductors, YBa(2)Cu(3)O(7-delta) and Nd2-xCexCuO4-y, is presented. When samples were illuminated by highly collimated x-rays produced on a synchrotron wiggler, small changes in the lattice were detected over a spatial scale of 10 micrometers. These changes are interpreted as evidence of variations in the oxygen content in one case and in the cerium content in the other; both affect the superconducting properties. The existence of such structural inhomogeneities brings into question whether exotic experimental results obtained from superconducting materials with high transition temperatures actually reflect intrinsic properties.

[Effect of yizhiling granule on experimental pathological model of Alzheimer's disease]

Alzheimer's disease is an important problem of gerontology which manifested as serious loss of memory, especially of recent memory, decrease of brain weight. The pathological model of the disease in mice was made with administration of AlCl3 and then Yizhiling Granule was given to treat it.

RESULTS

In the experiment of one trial passive avoidance response there were significant difference between the normal group and the model group (P < 0.01) and significant difference between the treated group and the model group (P < 0.05-0.01); as for fresh brain weight, the treated group was significantly different from the normal group (P < 0.01) and model group (P < 0.05). They indicate that Yizhiling Granule could improve memory and increase brain weight. This research seems to provide experimental basis for treatment of the disease.