Structural characterization, molecular dynamic simulation, and conformational visualization of a water-soluble glucan with high molecular weight from Gastrodia elata Blume.

Polysaccharides have been widely used in the development of natural drugs and health food. However, polysaccharide characterization lags due to inherently complicated features and the limitations of existing detection approaches. We aimed to provide new insight into the fine structure and conformational visualization of polysaccharides from Gastrodia elata Blume, a medicinal and edible plant. A water-soluble polysaccharide (GEP2-6) with the high molecular weight of 2.7 × 106 Da was first obtained, and its purity reached 99.2 %. Chemical and spectroscopic analyses jointly revealed that GEP2-6 was a glucan linked by α-(1 â†’ 4) and α-(1 â†’ 6) glycosidic bonds. After enzymolysis, the local structure of GEP2-6 included α-1,4-Glcp, α-1,6-Glcp, α-1,4,6-Glcp, and α-1-Glcp at a molar ratio of 31.27∶1.32∶1.08∶0.93. The glycosidic linkage pattern of repeating units was further simulated by a glycan database and spatial examination software. The good dissolution performance was interpreted by dynamics simulation and practical molecular characteristics. Spherical flexible chains and the porous stable conformation were corroborated using atomic force microscopy. In addition, GEP2-6 could effectively scavenge DPPH and hydroxyl radicals as a promising natural antioxidant. These efforts will contribute to the expansion of clinical applications of this G. elata polysaccharide and the structural elucidation for macromolecular polysaccharides combined with traditional and modern analysis techniques.

[LC-MS fingerprint and multi-indicator components analysis of classical formula Gualou Xiebai Banxia Decoction].

This study developed an optimal pre-processing technique for the reference substance of the classic formula Gualou Xiebai Banxia Decoction(GXBD) and established a comprehensive quality control method for GXBD reference substance to provide a reference for its overall quality evaluation. The authors prepared 15 batches of GXBD samples and innovatively used the extracted ion chromatogram under the base peak chromatogram mode to establish a liquid chromatography-mass spectrometry(LC-MS) fingerprint, identify characteristic peaks, and perform quantitative analysis of indicator components. The yield of the 15 batches of GXBD samples ranged from 50.28% to 76.20%. In the positive ion mode, 12 common characteristic peaks were detected in the LC-MS fingerprint, and the structures of five common peaks were identified by comparison with reference standards. The similarity between the fingerprint profiles of different batches of samples and the reference fingerprint profile ranged from 0.920 to 0.984. Finally, liquid chromatography-triple quadrupole mass spectrometry(LC-QQQ/MS) in multiple reaction monitoring(MRM) mode was used to determine the content of eight indicator components in GXBD, including loliolide, chrysoeriol, rutin, cucurbitacin D, macrostemonoside Ⅰ, 25S-timosaponin B Ⅱ, 25R-timosaponin B Ⅱ, and peptide proline-tryptophan-valine-proline-glycine(PWVPG). The method established in this study can reduce matrix interference in the compound, and it has good accuracy, stability, and practical value. It effectively reflects the quality attributes of GXBD samples and can be used for the comprehensive quality control of GXBD.

Tension-Tension Fatigue Behavior of High-Toughness Zr61Ti2Cu25Al12 Bulk Metallic Glass.

Bulk metallic glasses have application potential in engineering structures due to their exceptional strength and fracture toughness. Their fatigue resistance is very important for the application as well. We report the tension-tension fatigue damage behavior of a Zr61Ti2Cu25Al12 bulk metallic glass, which has the highest fracture toughness among BMGs. The Zr61Ti2Cu25Al12 glass exhibits a tension-tension fatigue endurance limit of 195 MPa, which is higher than that of high-toughness steels. The fracture morphology of the specimens depends on the applied stress amplitude. We found flocks of shear bands, which were perpendicular to the loading direction, on the surface of the fatigue test specimens with stress amplitude higher than the fatigue limit of the glass. The fatigue cracking of the glass initiated from a shear band in a shear band flock. Our work demonstrated that the Zr61Ti2Cu25Al12 glass is a competitive structural material and shed light on improving the fatigue resistance of bulk metallic glasses.

Efficacy of Dexamethasone for Reducing Edema and Ecchymosis After Rhinoplasty: A Systematic Review and Meta-analysis.

BACKGROUND: Rhinoplasty is one of the most challenging cosmetic surgical operations. The procedure has been known to precipitate higher levels of edema and ecchymosis in the periorbital and paranasal regions. The literature recommends the use of corticosteroids such as dexamethasone to alleviate these postoperative morbidities. In this review, we aim to provide a current state of evidence concerning the influence of dexamethasone together with rhinoplasty on intraoperative and postoperative morbidities. METHODS: A systematic identification of the literature was performed according to PRISMA guidelines on four academic databases: MEDLINE, Scopus, EMBASE and CENTRAL. A meta-analysis compared the influence of dexamethasone and normal saline administered during rhinoplasty on the amount of intraoperative blood loss, postoperative edema and ecchymosis. RESULTS: Out of 1045 records, ten articles including 374 participants (mean age: 25.8 ± 2.5 years) were included in this review. This systematic review presents a 1b level of evidence supporting the use of dexamethasone during rhinoplasty to reduce the amount of intraoperative blood loss, edema and ecchymosis as compared to normal saline. The meta-analysis reveals beneficial effects for dexamethasone interventions by demonstrating medium to large effect reduction of the amount of intraoperative blood loss (Hedge's g: - 0.69), mean edema score (- 1.09) and mean ecchymosis score (- 1.03) as compared to placebo groups using normal saline. CONCLUSION: The current systematic review and meta-analysis recommend the administration of dexamethasone with rhinoplasty. The review reports beneficial effects of dexamethasone's administration as compared to normal saline for reducing the amount of intraoperative blood loss, postoperative edema and ecchymosis. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Shengui Sansheng Pulvis maintains blood-brain barrier integrity by vasoactive intestinal peptide after ischemic stroke.

Background Shengui Sansheng Pulvis (SSP) has about 300 years history used for stroke treatment, and evidences suggest it has beneficial effects on neuro-angiogenesis and cerebral energy metabolic amelioration post-stroke. However, its protective action and mechanisms on blood-brain barrier (BBB) is still unknown. Purpose Based on multiple neuroprotective properties of vasoactive intestinal peptide (VIP) in neurological disorders, we investigate if SSP maintaining BBB integrity is associated with VIP pathway in rat permanent middle cerebral artery occlusion (MCAo) model. Methods Three doses of SSP extraction were administered orally. Evaluations of motor and balance abilities and detection of brain edema were performed, and BBB permeability were assessed by Evans blue (EB) staining. Primary brain microvascular endothelial cells (BMECs) were subjected to oxygen-glucose deprivation, and incubated with high dose SSP drug-containing serum and VIP-antagonist respectively. Transendothelial electrical resistance (TEER) assay and Tetramethylrhodamine isothiocyanate (TRITC)-dextran (4.4 kDa) and fluorescein isothiocyanate (FITC)-dextran (70 kDa) were used to evaluate the features of paracellular junction. Western blot detected the expressions of Claudin-5, ZO-1, Occludin and VE-cadherin, matrix metalloproteinase (MMP) 2/9 and VIP receptors 1/2, and immunofluorescence staining tested VIP and Claudin-5 expressions. Results Our results show that SSP significantly reduces EB infiltration in dose-dependent manner in vivo and attenuates TRITC- dextran and FITC-dextran diffusion in vitro, and strengthens endothelial junctional complexes as represented by decreasing Claudin-5, ZO-1, Occludin and VE-cadherin degradations and MMP 2/9 expression, as well as promoting TEER in BMECs after ischemia. Moreover, it suggests that SSP notably enhances VIP and its receptors 1/2 expressions. VIP-antagonist exacerbates paracellular barrier of BMECs, while the result is reversed after incubation with high dose SSP drug-containing serum. Additionally, SSP also improve brain edema and motor and balance abilities after ischemic stroke. Conclusions we firstly demonstrate that the ameliorated efficacy of SSP on BBB permeability is related to the enhancements of VIP and its receptors, suggesting SSP might be an effective therapeutic agent on maintaining BBB integrity post-stroke.

Edaravone reduces oxidative stress and intestinal cell apoptosis after burn through up-regulating miR-320 expression.

BACKGROUND: Intestinal mucosa barrier dysfunction after burn injury is an important factor for causing mortality of burn patients. The current study established a burn model in rats and used a free radical scavenger edaravone (ED) to treat the rats, so as to investigate the effect of edaravone on intestinal mucosa barrier after burn injury. METHODS: Anesthetized rats were subjected to 40% total body surface area water burn immediately, followed by treatment with ED, scrambled antagomir, or antagomiR-320. Intestinal mucosa damage was observed by hematoxylin-eosin staining and graded by colon mucosal damage index (CMDI) score. The contents of total sulfhydryl (TSH), superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) were determined by spectrophotometry. Cell apoptosis, protein relative expression,and the in situ expressions of p-Akt and p-Bad were detected by flow cytometry, Western blotting and immunohistochemistry, respectively. The miR-320 expression was determined by quantitative real-time polymerase chain reaction. RESULTS: ED alleviated intestinal mucosal damage caused by burn injury, down-regulated the levels of MDA, cytochrome C, cleaved caspase-9 and cleaved caspase-3, but up-regulated the levels of TSH, SOD, CAT and Bcl-2. We also found that ED could reduce oxidative stress, inhibit cell apoptosis, increase the expressions of p-Akt, p-Bad and miR-320, and decrease PTEN expression. PTEN was predicted to be the target gene for miR-320, and cell apoptosis could be promoted by inhibiting miR-320 expression. CONCLUSION: ED regulates Akt/Bad/Caspase signaling cascade to reduce apoptosis and oxidative stress through up-regulating miR-320 expression and down-regulating PTEN expression, thus protecting the intestinal mucosal barrier of rats from burn injury.

Pharmacological modulation of the voltage-gated neuronal Kv7/KCNQ/M-channel alters the intrinsic excitability and synaptic responses of pyramidal neurons in rat prefrontal cortex slices.

The prefrontal cortex (PFC) critical for higher cognition is implicated in neuropsychiatric diseases, such as Alzheimer's disease, depression and schizophrenia. The voltage-activated Kv7/KCNQ/M-channel or M-current modulates the neuronal excitability that defines the fundamental mechanism of brain function. However, whether M-current functions to regulate the excitability of PFC neurons remains elusive. In this study, we recorded the native M-current from PFC layer V pyramidal neurons in rat brain slices and showed that it modulated the intrinsic excitability and synaptic responses of PFC pyramidal neurons. Application of a specific M-channel blocker XE991 (40 µmol/L) or opener retigabine (10 µmol/L) resulted in inhibition or activation of M-current, respectively. In the current-clamp recordings, inhibition of M-current was evidenced by the increased average spike frequency and the reduced first inter-spike interval (ISI), spike onset latency and fast afterhyperpolarization (fAHP), whereas activation of M-current caused opposite responses. Furthermore, inhibition of M-current significantly increased the amplitude of excitatory postsynaptic potentials (EPSPs) and depolarized the resting membrane potential (RMP) without affecting the miniature EPSC (mEPSC) frequency. These data demonstrate that voltage-gated neuronal Kv7/KCNQ/M-current modulates the excitability and synaptic transmission of PFC neurons, suggesting that pharmacological modulation of M-current in the PFC may exert beneficial effects on cognitive deficits implicated in the pathophysiology of neuropsychiatric disorders.

Identification and in vitro pharmacological characterization of a novel and selective α7 nicotinic acetylcholine receptor agonist, Br-IQ17B.

AIM: Alpha7-nicotinic acetylcholine receptor (α7 nAChR) is a ligand-gated Ca(2+)-permeable ion channel implicated in cognition and neuropsychiatric disorders. Activation of α7 nAChR improves learning, memory, and sensory gating in animal models. To identify novel α7 nAChR agonists, we synthesized a series of small molecules and characterized a representative compound, Br-IQ17B, N-[(3R)-1-azabicyclo[2,2,2]oct-3-yl]-5-bromoindolizine-2-carboxamide, which specifically activates α7 nAChR. METHODS: Two-electrode voltage clamp (TEVC) recordings were primarily used for screening in Xenopus oocytes expressing human α7 nAChR. Assays, including radioisotope ligand binding, Western blots, whole-cell recordings of hippocampal culture neurons, and spontaneous IPSC recordings of brain slices, were also utilized to evaluate and confirm the specific activation of α7 nAChR by Br-IQ17B. RESULTS: Br-IQ17B potently activates α7 nAChR with an EC50 of 1.8±0.2 µmol/L. Br-IQ17B is selective over other subtypes such as α4ß2 and α3ß4, but it blocks 5-HT3A receptors. Br-IQ17B displaced binding of the α7 blocker [(3)H]-MLA to hippocampal crude membranes with a Ki of 14.9±3.2 nmol/L. In hippocampal neurons, Br-IQ17B evoked α7-like currents that were inhibited by MLA and enhanced in the presence of the α7 PAM PNU-120596. In brain slice recordings, Br-IQ17B enhanced GABAergic synaptic transmission in CA1 neurons. Mechanistically, Br-IQ17B increased ERK1/2 phosphorylation that was MLA-sensitive. CONCLUSION: We identified the novel, potent, and selective α7 agonist Br-IQ17B, which enhances synaptic transmission. Br-IQ17B may be a helpful tool to understand new aspects of α7 nAChR function, and it also has potential for being developed as therapy for schizophrenia and cognitive deficits.

Structure determination of two new indole-diterpenoids from Penicillium sp. CM-7 by NMR spectroscopy.

Two new indole-diterpenoids 4b-deoxy-1'-O-acetylpaxilline (1) and 4b-deoxypenijanthine A (2) were isolated from the fermentation broth and the mycelia of the soil fungus Penicillium sp. CM-7, along with three known structurally related compounds, 1'-O-acetylpaxilline (3), paspaline (4) and 3-deoxo-4b-deoxypaxilline (5). The structures of compounds 1 and 2 were elucidated by extensive spectroscopic methods, especially 2D NMR, and their absolute configurations were suggested on the basis of the circular dichroism spectral analysis and the NOESY data.

[Effects of oxymatrine on the expressions of pro-collagen and fibronectin of fibroblasts derived from human hyperplastic scars].

OBJECTIVE: To study the effects of oxymatrine (OM) on the expressions of pro-collagen I (PC I), pro-collagen II (PC III), fibronectin (FN), matrix metalloproteinase-1 (MMP-1) mRNA of fibroblasts from keloid (KFb), hyperplastic scar (HFb), and normal skin (NFb), and to compare with hydrocortisone (HC). METHODS: The primary KFb, HFb and NFb were derived from patients and cultured in vitro using tissue block culture method. The fibroblasts were treated with 500 microg/mL OM, 2 microg/mL HC, or without any medicine (as the control). The mRNA expressions of PC I, PC III, FN, MMP-1 of the fibroblasts were detected using RT-PCR. RESULTS: Under the normal condition, when compared with NFb, the mRNA expressions of PC I of KFb and HFb increased by 31.7% and 34.2% (both P < 0.05). Besides, the mRNA expression of PC III of KFb increased by 44.9% (P < 0.01). OM down-regulated the mRNA expressions of FN and PC I of HFb by 18.8% and 23.6% respectively (both P < 0.05). HC decreased the mRNA expressions of FN and PC I of HFb by 26.8% and 43.6% respectively (P < 0.05, P < 0.01). Meantime, OM up-regulated the mRNA expression of MMP-1 of KFb by 21.8% (P < 0.05). CONCLUSIONS: OM suppressed the synthesis of extracellular matrix (ECM) possibly through down-regulating the mRNA expressions of PC I and FN. Compared with HC, OM could promote the degradation of ECM through inducing the MMP-1 mRNA expressions of KFb. Therefore, OM could be potentially used in treatment of hypertrophic scar and keloid.

[Effect of periostin on the function of human umbilical vein endothelial cells in acidic environment].

OBJECTIVE: To observe the effect of recombinant periostin protein on the proliferation, apoptosis and migration of human umbilical vein endothelial cells (HUVECs) in acidic environment. METHODS: HUVECs were divided into three groups: normal control (pH 7.31±0.03), acidic control (pH 6.95±0.05) and experimental groups [(periostin 100 µg/L, (pH 6.95±0.05)]. The cellular proliferation,apoptosis and migration were measured by Cell Counting Kit-8(CCK-8) assay, Annexin V-FITC with Flow Cytometer(at 60 h after periostin was given) and Transwell chamber assay (at 20 h after periostin was given). RESULTS: In CCK-8 assay, the optical density values D450 nm (at 72 h after periostin was given) of normal control, acidic control and experimental groups were 0.71± 0.05, 0.62±0.04, 0.69±0.02, respectively. In the same order, the total apoptotic rate (%) of the three groups were 13.06±1.35, 16.95±0.46, 12.97±1.60, respectively; the numbers of migrated cells of the three groups were 67.45±11.88,44.89±8.67,64.60±9.63, respectively. Compared with normal control, the D(450 nm) value and the number of migrated cells of acidic control reduced 12.68% (P<0.01) and 33.44% (P<0.01) respectively. Otherwise, the total apoptotic rate (%) increased by 29.79% (P<0.05). Compared with acidic control, the D(450 nm) value and the number of migrated cells of experimental group increased by 11.29% (P<0.01) and 43.90% (P<0.01), respectively. Meantime, the total apoptotic rate (%) reduced 23.48% (P<0.05). CONCLUSION: In acidic environment, the HUVECs' abilities of proliferation and migration were lower; while, the apoptotic value was raised. The recombinant periostin protein could counteract the acidic influence by enhancing the cellular abilities of proliferation and migration. Periostin could make endothelial cells reisist acidosis and keep growing to form blood vessels so that the local histiocytes could get enough nutrients for survival.

[Community structure and distribution pattern of a natural secondary forest in Beigou forest farm].

Taking the 4 hm2 fixed sampling plot in the Beigou forest farm of Weichang County in Hebei Province as test object, and by adopting the parameters (point pattern distribution, mingling, and size differentiation), this paper analyzed the community structure and distribution pattern of a natural secondary forest in the farm. There were eleven populations in the arbor layer of the forest, among which, Populus davidiana and Betula platyphylla had the obvious advantage in population density and basal area, being the dominant and constructive species of the arbor layer. Spatially, these two species all presented cluster modes remarkably, and competed each other greatly. The main accompanying species Larix principis-rupprechti and Acer truncatum also presented cluster modes, but the density and volume were significantly lower than the two dominant species', not able to compete with the dominate species. Affected by the low mingling of dominant species, the average mingling of the whole stand was only 0.40, while the mingling of accompanying species generally presented moderate or high. The mean size differentiation of the whole stand was 0.49, and P. davidiana, B. platyphylla, L. principis-rupprechti, and Quercus mongolica were of dominance or sub-dominance in the spatial structural units, while the other accompanying species had no obvious dominance.

Purification and characterization of laccase from Pycnoporus sanguineus and decolorization of an anthraquinone dye by the enzyme.

The white rot fungus Pycnoporus sanguineus produced high amount of laccase in the basal liquid medium without induction. Laccase was purified using ultrafiltration, anion-exchange chromatography, and gel filtration. The molecular weight of the purified laccase was estimated as 61.4 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme oxidized typical substrates of laccases including 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonate), 2,6-dimethoxyphenol, and syringaldazine. The optimum pH and temperature for the purified laccase were 3.0 and 65 degrees C, respectively. The enzyme was stable up to 40 degrees C, and high laccase activity was maintained at pH 2.0-5.0. Sodium azide, L-cysteine, and dithiothreitol strongly inhibited the laccase activity. The purified enzyme efficiently decolorized Remazol Brilliant Blue R in the absence of added redox mediators. The high production of P. sanguineus laccase as well as its decolorization ability demonstrated its potential applications in dye decolorization.