Saturnispora sinensis sp. nov., a new ascomycetous yeast species from soil and rotten wood.

A yeast strain (CGMCC 2.6937T) belonging to the ascomycetous yeast genus Saturnispora was recently isolated from soil collected in Xinghuacun, Shanxi Province, PR China. The strain produces one or two ellipsoid or spherical ascospores in asci formed by the conjugation between a cell and its bud. Phylogenetic analyses of the internal transcribed spacer (ITS) region and the D1/D2 domain of the large subunit rRNA gene suggest that this strain is conspecific with strains NYNU 14639 isolated from rotten wood collected in Funiu Mountain, Henan province and ES13S05 from soil collected in Nantou County, Taiwan. The CGMCC 2.6937T group is most closely related to Saturnispora dispora and Saturnispora zaruensis. However, strain CGMCC 2.6937T differs from S. dispora by 17 (3.2 %, 13 substitutions and four gaps) and 77 (18.8 %, 52 substitutions and 25 gaps) mismatches, and from S. zaruensis by 15 (2.9 %, 12 substitutions and three gaps) and 64 (15.6 %, 44 substitutions and 20 gaps) mismatches, in the D1/D2 domain and ITS region, respectively. The results suggest that the CGMCC 2.6937T group represents an undescribed species in the genus Saturnispora, for which the name Saturnispora sinensis sp. nov. is proposed. The holotype strain is CGMCC 2.6937T.

A Radio Environment Map Updating Mechanism Based on an Attention Mechanism and Siamese Neural Networks.

A radio environment map (REM) is an effective spectrum management tool. With the increase in the number of mobile devices, the wireless environment changes more and more frequently, bringing new challenges to REM updates. Traditional update methods usually rely on the amount of data collected for updating without paying attention to whether the wireless environment has changed enough. In particular, a waste of computational resources results from the frequently updated REM when the wireless environment does not change much. When the wireless environment changes a lot, the REM is not updated promptly, resulting in a decrease in REM accuracy. To overcome the above problems, this work combines the Siamese neural network and an attention mechanism in computer vision and proposes an update mechanism based on the amount of wireless environmental change starting from image data. The method compares the newly collected crowdsourced data with the constructed REM in terms of similarity. It uses similarity to measure the necessity of the REM to be updated. The algorithm in this paper can achieve a controlled update by setting a similarity threshold with good controllability. In addition, the effectiveness of the algorithm in detecting changes of the wireless environment has been demonstrated by combing simulation data.

Two new flavonoids from Morus notabilis.

Phytochemical investigation of the twigs of Morus notabilis led to the isolation and characterization of two new flavonoids, notabilisin F (1) and notabilisin G (2). Their structures were elucidated on the basis of extensive spectroscopic analysis.

[Chemical constituents from Morus notabilis and their cytotoxic effect].

Une new flavonoids named as notabilisin K (1), together with four known compounds, morusin (2), mulberrofuran A (3), neocyclomorusin (4) and mornigrol F (5) are separated from 95% ethanol extracts of the twigs of Morus notabilis. Compounds 2-5 are separated from this plant for the first time. Notabilisin I, notabilisin J exhibits certain effect against cells of HCT-116, HepG2 and A2780 with IC50 values ranging from 1.47 µmol x L(-1) to 5.46 µmol x L(-1). Morusin exhibits strong effect against five kinds of human cancer cells (BGC823, A2780, HCT-116, HepG2 and NCI-H1650) with IC50 values ranging from 0.74 µmol x L(-1) to 1.58 µmol x L(-1).

Characterization of key aroma compounds in aged Qingxiangxing baijiu by comparative aroma extract dilution analysis, quantitative measurements, aroma recombination, and omission studies.

Aging aroma is an intriguing but an understudied phenomenon in baijiu. The aromatic characteristics of Qingxiangxing (QXX) baijiu stored for 45 years (aged) were investigated using the sensomics approach and were compared with those of young baijiu (0 year-old). Aroma extract dilution analysis revealed 59 odorants, with many long-retained components exhibiting greater flavor dilution values in the aged than the young sample. The analysis of variance of the quantitative data showed significant differences between the young and aged baijiu for 26 compounds. Based on the variations in the content of these compounds, QXX baijiu aged for 0, 5, 15, 20, and 45 years was analyzed and twelve compounds were significantly correlated with aging duration. Finally, eight positively correlated compounds were omitted from the recombinant model, and sotolon, methional, vanillin, dimethyl trisulfide, benzaldehyde, and 3-hydroxy-2-butanone were confirmed to primarily contribute toward the aging aroma of QXX baijiu.

Microbial communities and their correlation with flavor compound formation during the mechanized production of light-flavor Baijiu.

Light-flavor Baijiu fermentation is a typical spontaneous solid-state fermentation process fueled by a variety of microorganisms. Mechanized processes have been increasingly employed in Baijiu production to replace traditional manual operation processes, however, the microbiological and physicochemical dynamics in mechanized processes remain largely unknown. Here, we investigated the microbial community succession and flavor compound formation during a whole mechanized fermentation process of light-flavor Baijiu using the conventional dilution plating method, PacBio single-molecule real-time (SMRT) sequencing and headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry. The results showed that largely different fungal and bacterial communities were involved in the soaking and fermentation processes. A clear succession from Pantoea agglomerans to Bacillus (B.) smithii and B. coagulans in dominant bacterial species and from Cladosporium exasperatum to Saccharomyces cerevisiae and Lichtheimia ramosa in dominant fungal species occurred in the soaking processes. In the fermentation process, the most dominant bacterial species was shifted from Pantoea agglomerans to Lactobacillus (La.) acetotolerans and the most dominant fungal species were shifted from Lichtheimia ramose and Rhizopus arrhizus to Saccharomyces cerevisiae. The bacterial and fungal species positively associated with acidity and the formation of ethanol and different flavor compounds were specified. The microbial species exhibited strong co-occurrence or co-exclusion relationships were also identified. The results are helpful for the improvement of mechanized fermentation process of light-flavor Baijiu production.

Microbial Community Affects Daqu Quality and the Production of Ethanol and Flavor Compounds in Baijiu Fermentation.

Daqu is a traditional starter for Baijiu fermentation and is produced by spontaneous fermentation of ground and moistened barley or wheat. The quality of Daqu is traditionally evaluated based on physicochemical and subjective sensory parameters without microbiological analysis. Here, we compared the physicochemical characteristics of qualified (QD) and inferior (ID) Daqu, their microbial communities based on plate counting and PacBio SMRT sequencing of rRNA gene libraries, and their impacts on Baijiu fermentation. The results showed that the glucoamylase and α-amylase activities of QD were significantly higher than those of ID. The counts of yeasts and relative abundances of functional microbes, especially the amylolytic bacterium Bacillus licheniformis and fungi Saccharomycopsis fibuligera and Lichtheimia ramosa, were significantly higher in QD than in ID. The laboratory-scale Baijiu fermentation tests showed that the relative abundances of the amylolytic microbes were higher in the QD than the ID fermentation set, resulting in more efficient fermentation, as indicated by more weight loss and higher moisture content in the former. Consequently, more glycerol, acetic acid, ethanol, and other volatile compounds were produced in the QD than in the ID fermentation set. The results suggest that Daqu quality is determined by, and can be evaluated based on, its microbial community.

Deregulation of CLTC interacts with TFG, facilitating osteosarcoma via the TGF-beta and AKT/mTOR signaling pathways.

Although the treatment of osteosarcoma has improved, the overall survival rate of this common type of osseous malignancies has not changed for four decades. Thus, new targets for better therapeutic regimens are urgently needed. In this study, we found that high expression of clathrin heavy chain (CLTC) was an independent prognostic factor for tumor-free survival (HzR, 3.049; 95% CI, 1.476-6.301) and overall survival (HzR, 2.469; 95% CI, 1.005-6.067) of patients with osteosarcoma. Down-regulation of CLTC resulted in tumor-suppressive effects in vitro and in vivo. Moreover, we found that CLTC was transcriptionally regulated by a transcription factor-specificity protein 1 (SP1), which binds to the CLTC promoter at the -320 to -314-nt and +167 to +173-nt loci. Mechanistic investigations further revealed that CLTC elicited its pro-tumor effects by directly binding to and stabilizing trafficking from the endoplasmic reticulum to the Golgi regulator (TFG). Importantly, overexpression of TFG rescued both the tumor-suppressive effect and inhibition of the TGF-ß and AKT/mTOR pathways caused by CLTC down-regulation, which indicated that the activity of CLTC was TFG-dependent. Immunohistochemistry analysis confirmed that CLTC expression was positively correlated with TFG expression. These findings collectively highlight CLTC as a new prognostic biomarker for patients with osteosarcoma, and the interruption of the SP1/CLTC/TFG axis may serve as a novel therapeutic strategy for osteosarcoma.

Genetic diversity and population structure of the amylolytic yeast Saccharomycopsis fibuligera associated with Baijiu fermentation in China.

The amylolytic yeast Saccharomycopsis fibuligera is a predominant species in starters and the early fermentation stage of Chinese liquor (Baijiu). However, the genetic diversity of the species remains largely unknown. Here we sequenced the genomes of 97 S. fibuligera strains from different Chinese Baijiu companies. The genetic diversity and population structure of the strains were analyzed based on 1,133 orthologous genes and the whole genome single nucleotide polymorphisms (SNPs). Four main lineages were recognized. One lineage contains 60 Chinese strains which are exclusively homozygous with relatively small genome sizes (18.55-18.72 Mb) and low sequence diversity. The strains clustered in the other three lineages are heterozygous with larger genomes (21.85-23.72 Mb) and higher sequence diversity. The genomes of the homozygous strains showed nearly 100% coverage with the genome of the reference strain KPH12 and the sub-genome A of the hybrid strain KJJ81 at the above 98% sequence identity level. The genomes of the heterozygous strains showed nearly 80% coverage with both the sub-genome A and the whole genome of KJJ81, suggesting that the Chinese heterozygous strains are also hybrids with nearly 20% genomes from an unidentified source. Eighty-three genes were found to show significant copy number variation between different lineages. However, remarkable lineage specific variations in glucoamylase and α-amylase activities and growth profiles in different carbon sources and under different environmental conditions were not observed, though strains exhibiting relatively high glucoamylase activity were mainly found from the homozygous lineage.

Effect of Buyi Pishen acupuncture on inflammatory factor and cartilage matrix in adjuvant arthritis rats / 中国针灸

OBJECTIVE@#To observe the effect of Buyi Pishen acupuncture (acupuncture for invigorating spleen and kidney) on inflammatory factor and synovial cartilage matrix in adjuvant arthritis (AA) rats, and to explore the mechanism of acupuncture for rheumatoid arthritis (RA).@*METHODS@#A total of 60 clean male Wistar rats were randomized into a normal group, a model group, a tripterygium wilfordii polyglycoside tablet (TWP) group and an acupuncture group, 15 rats in each group. Rats in the model group, the TWP group and the acupuncture group received intradermal injection of Freund's complete adjuvant (FCA) at right hind foot pad to induce the AA model. TWP suspension of 8 mg/kg was given by gavage in the TWP group. Acupuncture was applied at "Shenshu" (BL 23), "Pishu" (BL 20) and right "Housanli" (ST 36), "Sanyinjiao" (SP 6), "Yanglingquan" (GB 34) in the acupuncture group, 15 min a time, once a day. The intervention was given 15 days in both TWP group and acupuncture group. The foot-pad swelling degree before modeling, before and after intervention and the arthritis index (AI) score before and after intervention were calculated; the serum levels of interleukin (IL)-1β, IL-4, IL-10 and tumor necrosis factor-α (TNF-α) were detected by ELISA method; the ultrastructure and histomorphological changes of synovium issue were observed by transmission electron microscope and HE staining; the positive expression of matrix metalloproteinase (MMP)-3 and MMP-9 in synovium issue was detected by immunohistochemistry method.@*RESULTS@#Before intervention, foot-pad swelling degree of the model group, the TWP group and the acupuncture group was increased compared with the normal group (P<0.01). After intervention, foot-pad swelling degree and AI score were increased compared with the normal group (P<0.01), foot-pad swelling degree and AI scores in the TWP group and the acupuncture group were lower than the model group (P<0.05), and those in the acupuncture group were decreased compared with the TWP group (P<0.05). The model group exhibited unclear nuclear membrane of synovial cells, chromatin pyknosis, massive inflammatory cell infiltration and hyperplasia in synovial tissue; the TWP group and the acupuncture group exhibited clear and smooth nuclear membrane of synovial cells, inapparent chromatin pyknosis, less inflammatory cell infiltration and hyperplasia in synovial tissue, the acupuncture group exhibited less matrix destruction as well. Compared with the normal group, serum levels of IL-1β and TNF-α and positive expression of MMP-3 and MMP-9 in synovium issue were increased (P<0.01), while serum levels of IL-4 and IL-10 were decreased (P<0.01) in the model group. Compared with the model group, serum levels of IL-1β and TNF-α and positive expression of MMP-3 and MMP-9 in synovium issue were decreased (P<0.05, P<0.01), while serum levels of IL-4 and IL-10 were increased (P<0.05) in the TWP group and the acupuncture group; compared with the TWP group, serum level of TNF-α and positive expression of MMP-3 and MMP-9 in synovium issue were decreased (P<0.05), while serum levels of IL-4 and IL-10 were increased (P<0.05) in the acupuncture group.@*CONCLUSION@#Buyi Pishen acupuncture can effectively improve the injury of articular cartilage in AA rats, its mechanism maybe related to reducing the inflammatory reaction in synovium and inhibiting the degradation of articular cartilage matrix.

Transmission Model of Tendon-Sheath System for Endoscopic Flexible Instrument and Experimental Study / 医用生物力学

Objective To establish the pushing transmission model of tendon-sheath system (TSS) for endoscopic flexible instrument, and study the key influencing factors of transmission efficiency. Methods The force and displacement transmission models of TSS in pushing configuration were built and simulated. The tendon-sheath transmission testing platform was designed to validate the model. The influencing factors, such as transmission velocity, tendon-sheath diameter ratio, curvature radius, were explored using this setup. Results There were obvious nonlinear phenomenon in force and displacement transmission. The model simulation results accorded quite well with the experiment results. Transmission velocity, tendon-sheath diameter ratio, curvature radius all had great effects on pushing force transmission of endoscopic flexible instrument, while they had a smaller effect on displacement transmission. Conclusions The proposed model can be used for calculating pushing force transmission of tendon-sheath system for endoscopic flexible instrument, so as to provide the doctors with force feedback at the tip of the end effector, and ensure the safe operation and improve the surgical effects. For better design and control of endoscopic flexible instrument, the transmission velocity, tendon-sheath diameter ratio, curvature radius must be comprehensively considered.

Design and Experimental Study on Flexible Articulation of Electric Stapler / 医用生物力学

Objective To design a notched flexible articulation applied to electric stapler and study its turning performance. Methods The notched flexible articulation was designed and modeled. The kinematics and statics models of the articulation were established for simulation calculations. The stress, deflection angle, top displacement and driving force of the articulation with 3 different turning structures were studied under equal and variable stiffness of symmetrical notches by using finite element simulation. An experimental platform for performance test of the turning structure was built to verify the simulation results and the model. Results The theoretical model of the turning structure in bending process was basically consistent with the experimental results. With the optimization of symmetrical notch stiffness, the maximum stress of the articulation with variable stiffness was reduced by 20.64% and 39.20%, respectively. The articulation with variable stiffness required the smallest tensile force during bending, which was 33.41% lower than that of the articulation with equal stiffness, and the tip displacement (30.8 mm) along the bending plane was the smallest. The maximum deflection angle for the articulation with 3 different turning structures all could reach 90°. Conclusions The kinematics and statics models of the articulation can be used for the calculation of its tensile force and position changes. The turning performance of the articulation with variable stiffness using symmetrical notch is better than that with equal stiffness. The notched flexible articulation meets the design requirements and the turning needs of electric stapler.

Postoperative Survival of Triple Negative Breast Cancer Patients After High Exposure to Traditional Chinese Medicine： A Cohort Study / 中国实验方剂学杂志

Objective:To evaluate the 3-year survival outcomes of postoperative patients after high exposure to traditional Chinese medicine （TCM） for triple negative breast cancer （TNBC）. Method:The complete 3-year follow-up data of 150 postoperative patients with stage I–III TNBC were retrospectively analyzed. All the patients received routine western medical treatments （surgery， chemotherapy， and/or radiotherapy） according to the National Comprehensive Cancer Network （NCCN） clinical practice guidelines in oncology as well as TCM. According to the degree of exposure to TCM， they were divided into the high- and low-exposure cohorts， with the oral administration of Chaihu Longmu Decoction with or without anti-cancer Chinese patent medicine for at least six months annually， or 18 months or more in the three years as the inclusion criterion for the former cohort. The metastatic sites of recurrent TNBC and the recurrent metastasis/death time were observed in both cohorts to compare the disease-free survival （DFS） and overall survival （OS）. The influences of onset age， pathological type， histopathological grade， vascular invasion， clinical stage， and exposure to TCM on survival were subjected to statistical analysis， followed by the observation of adverse effects. Result:There was no significant difference in the metastatic sites between the two cohorts （<italic>P</italic>>0.05）. The high-exposure cohort had a longer 3-year DFS than the low-exposure cohort， and the 3-year DFS rate in the high-exposure cohort was increased by 16.9% （χ²=6.995， <italic>P</italic>=0.008） as compared with that in the low-exposure cohort， exhibiting a significant difference （<italic>P</italic><0.05）. As revealed by the Cox proportional-hazards model， patients in the low-exposure cohort had a 3.724-fold as high risk of recurrent metastasis as that in the high-exposure cohort （95%CI 1.399~9.915）. There was no significant difference in the 3-year OS between the two cohorts （<italic>P</italic>>0.05）. The overall incidence of adverse effects in both groups was 7.3%， mainly manifested as gastrointestinal discomfort. Conclusion:High exposure to TCM contributes to reducing postoperative recurrence and metastasis and prolonging DFS.

Increasing Selenium and Yellow Pigment Concentrations in Foxtail Millet (Setaria italica L.) Grain with Foliar Application of Selenite.

Although addition of selenium (Se) is known to increase Se in crops, it is unclear whether exogenous Se is linked to nutritional and functional components in foxtail millet (Setaria italica L.). In this study, we examined the potential of increasing Se and yellow pigment (YP) in foxtail millet grain by foliar application of Se. Field experiments were conducted during the growing season of foxtail millet in 2013 and 2014 to assess the effects of foliar spray of sodium selenite (10-210 g Se ha(-1)) on the yield, Se uptake and accumulation, total YP, and microminerals in the grain. Average grain yields with Se application were 5.60 and 4.53 t ha(-1) in the 2 years, showing no significant differences from the unfertilized control. However, grain Se concentration increased linearly with Se application rate, by 8.92 and 6.09 µg kg(-1) in the 2 years with application of 1 g Se ha(-1) (maximum grain recovery rates of Se fertilizer, 52 and 28 %). Likewise, total grain YP concentration markedly increased by 0.038 and 0.031 mg kg(-1) in the 2 years with application of 1 g Se ha(-1). Grain Mn, Cu, Fe, and Zn concentrations were not significantly affected by Se application. This study indicated that foliar application of Se effectively and reliably increased the concentrations of Se and YP in foxtail millet grain without affecting the yield or mineral micronutrient concentrations. Thus, foliar-applied selenite has a significant potential to increase the concentrations of selenium and YP (putative lutein (Shen, J Cereal Sci 61:86-93, 2015; Abdel-Aal, Cereal Chem 79:455-457, 2002; Abdel-Aal, J Agric Food Chem 55:787-794, 2007)) of foxtail millet and, thus, the health benefits of this crop.

Design Optimization, Function Analysis and in vitro Experiments of an Electric Stapler for Minimally Invasive Surgery / 医用生物力学

Objective To develop a new type of electric stapler, so as to solve the problems of insufficient rotation angle, inconvenient operation and difficulty in controlling the pressing strength of existing products. Methods An electric stapler was designed and manufactured. The motion trajectory curve of the prototype was measured by using the three-coordinate imaging instrument to build functional test platform of the prototype, and the goodness of fit was used to evaluate consistency between the theoretical curve and the measured curve. The small intestine tissues of fresh pig were anastomosed at different bending angles of the front end, and the forming rate of the anastomotic stoma was measured. Results The goodness of fit between the test curve and the theoretical curve for both turning motion and shooting motion was ideal, while the goodness of fit between the test curve and the theoretical curve for pressing motion was not ideal when the turning joint was bent at 0°-30°, and was ideal when it was bent at 45°-60°. In performance test, the deformity rate of the nail was smaller than 1.14%, indicating that the bending angle had no significant impacts on the anastomotic effect. Conclusions The kinematics curves of shooting motion and turning motion are consistent with the theoretical curves. The pressing motion curves fluctuate at different bending angles, which will not affect the anastomotic effect, and the effect of the electric stapler meets the clinical requirements.

A study of the substance dependence effect of the ethanolic extract and iridoid-rich fraction from Valeriana jatamansi Jones in mice.

BACKGROUND: Recently we found the ethanolic extract and iridoid-rich fraction from Valeriana jatamansi Jones, which is a traditional Chinese medicine exhibited anxiolytic properties. OBJECTIVE: This study aims to the substance dependence effect of the ethanolic extract and iridoid-rich fraction. MATERIALS AND METHODS: The study included two experiments: Mice were given orally with ethanolic extract for 12 weeks or iridoid-rich fraction for 16 weeks in experiment I and experiment II, respectively. Diazepam was used as a control drug and the normal mice groups were administered with 0.5% carboxymethyl cellulose Na in both experiments. All groups were administered twice daily. Natural withdrawal symptoms, withdrawal-induced body weight change, audiogenic tail-erection test (in experiment I), and pentylenetetrazol (PTZ)-induced convulsion test (in experiment II) were measured. RESULTS: (1) Compared to normal group in both experiments, the diazepam-treated group exhibited obvious withdrawal symptoms of tail-erection, irritability, teeth chattering, etc; the body weight of them after withdrawal had a period of significant loss (P < 0.05 or P < 0.01); and the ratios of tail-erection and seizure in two experiments were improved significantly when mice were induced by mixer noise ringtone (experiment I) or PTZ (experiment II) (P < 0.05 or P < 0.01).(2) In experiment I and II, there were no significant differences between mice that received ethanolic extract or iridoid-rich fraction and normal group in terms of natural withdrawal symptoms and withdrawal-induced body weight change (P > 0.05); in audiogenic tail-erection test, it found that the significant difference compared with normal group was just in ethanolic extract 900 mg/kg dose group on week 8 (P < 0.05); in PTZ-induced convulsion test, mice in iridoid-rich fraction groups had a slightly tail-erection and seizure, all results of them were with no significant difference compare to normal mice (P > 0.05), while significant lower than diazepam group (P < 0.01). CONCLUSION: (1) The two experiments successfully established the physical dependence of diazepam by gradually increasing the dose.(2)There were just a few mice received with ethanolic extract for 12 weeks or iridoid-rich fraction for 16 weeks appearing some slight withdrawal symptoms after precipitated withdrawal, but it didn't show significant difference compared to normal mice. Therefore, these indicated that the risks of potential drug dependence about ethanolic extract and iridoid-rich fraction were far lower than that of diazepam.

Finite element analysis and experimental study of the performance of insulin pen needles / 国际生物医学工程杂志

Objective To compare and analyze the relationship between geometric parameters of the needle of different insulin pens and their puncture force, flow rate, and pressing force. Methods The human skin tissue model and needle model were established, and the finite element simulation analysis of needle puncture was performed. Using a test platform, 25 kinds of needles with different geometric parameters were tested for the puncture force, pushing pressure, flow rate and other parameters. The influence of geometric parameters on the performance of the needles were analyzed. Results The puncture force of the needle was closely related to its section design. Compared with the three-section needle, the five-section needle increases the secondary inclination angle and the condyle angle, increases the contact area between the needle and the tissue, and make the change of the contact angle more smoothly, which reduce the needle penetration force. The smaller the outer diameter of the needle, the smaller the penetrating power. The larger the inner diameter of the needle, the greater the fluid flow rate, the smaller the pushing pressure, and the higher the injection accuracy. Conclusions Five-section, ultra-thin-walled or ultra-thin-walled needles have more excellent performance. On the basis of ensuring the strength of the needle, the needle's geometry can be optimized to reduce the puncture force. The results of this study can provide theoretical basis and experimental basis for the design of needles for insulin pens.

Phytoestrogen α-Zearalanol attenuates homocysteine-induced apoptosis in human umbilical vein endothelial cells.

Hyperhomocysteinemia is an independent risk factor for cardiovascular diseases. The enhanced nitrative stress plays an important role in homocysteine-induced endothelial dysfunction. Previous studies have showed that phytoestrogen α -zearalanol alleviated endothelial injury in ovariectomized hyperhomocysteinemic rats; however, the underlying mechanism remains to be clarified. This study was to investigate the effects of α -zearalanol on homocysteine-induced endothelial apoptosis in vitro and explore the possible role of nitrative stress in these effects. Results showed that homocysteine (500 µ mol/L, 24 h) induced the apoptosis of human umbilical vein endothelial cells (HUVECs) obviously, and this effect was significantly attenuated by pretreatment with α -zearalanol (10(-8)~10(-6) mol/L). Moreover, α -zearalanol downregulated proapoptotic protein Bax, upregulated antiapoptotic proteins Bcl-2 and Bcl-XL, and decreased the expression and activity of caspase-9. These findings demonstrated that α -zearalanol could effectively alleviate homocysteine-induced endothelial apoptosis, and this antiapoptosis effect might be related to the inhibition of the intrinsic pathway. Western blot indicated an enhanced 3-nitrotyrosine expression in HUVECs when challenged with homocysteine, which was attenuated by pretreatment with α -zearalanol. This result implied that inhibition of nitrative stress might play a role in the protective effect of α -zearalanol on endothelial cells. Such discovery may shed a novel light on the antiatherogenic activities of α -zearalanol in hyperhomocysteinemia.

Construction and characterization of the stk and stp1 knockout mutant in streptococcus suis type 2 / 医学研究生学报

Objective Serine /threonine kinases (STK) and phosphatases (STP) regulate various physiological activities of prokaryotes by reversible phosphorylation of proteins .This paper aimed to study the effects of simultaneous deletion of the stk and stp1 genes on the biological characteristics and pathogenicity of streptococcus suis type 2, the Chinese virulent strain 05ZYH33. Methods The double mutant of the stk and stp1 genes of 05ZYH33 was constructed by homologous recombination .The biological characteristics of the wild strain 05ZYH33 and the mutant strain Δstk/stp1 were compared.The effects of the stk and stp1 deletion on bacterial virulence was analyzed using cell adhesion assay , anti-phagocytosis assay and the mouse model of infection . Results RT-PCR showed that the stk and stp1 genes were replaced by the spectinomycin resistance gene Spc r and the mutant strain was successfully constructed .Experi-ments of biological characterization revealed gradually increased value of 05ZYH33 and Δstk/stp1 at 2 hours after inoculation and a plateau period at 7 hours.The logarithmic phase of the mutant strain (A600≈0.4) was 1 hour later than that of the wild one , and the bacterial den-sity of the former was lower than that of the latter after the plateau pe -riod (0.8 vs 1.0).On the blood plates of 05ZYH33 and Δstk/stp1 were observed greyish, round, semitransparent, wet and smooth-sur-faced tiny bacterial colonies , around which there were hemolysis rings with no significant differences in colony morphology and hemolytic ac -tivity.In the experiment on pathogenicity , the mice of the 05ZYH33 group all died within 12 hours while 9 of the 30 mice in the Δstk/stp1 group died within 12 hours and all died within 24 hours. Conclusion The simultaneous deletion of the stk and stp1 genes may mainly affect the regulation of the proteins associated with bacte -rial proliferation and division.