Fluctuations of levels of several endogenous plant hormones in isolated rice ( Oryza sativa ssp. japonica) embryos during early and mid-embryogenesis and early stages of germination were studied by enzyme-linked immun...Fluctuations of levels of several endogenous plant hormones in isolated rice ( Oryza sativa ssp. japonica) embryos during early and mid-embryogenesis and early stages of germination were studied by enzyme-linked immunosorbent assay (ELISA). Embryos were collected at different days after pollination (DAP) and different days after imbibition (DAI) of mature seeds. The contents of gibberellin(1) (GA(1)), abscisic acid (ABA), isopentenyladenine and isopentenyladenosine ( iPAs), zeatin and zeatin riboside ( ZRs) were immunochemically assayed. The GA(1) level was the highest among all hormones tested. The variations of GA(1) levels were opposite with the ABA levels, with some exceptions. During early and mid-embryogenesis, the levels of GA(1) and ABA were the highest at 4 DAP. From 8 to 18 DAP, GA(1) level declined, whereas the ABA level increased. During germination, GA(1) level increased at 2 DAI whereas simultaneously the ABA content decreased. The highest ratio of GA(1)/ABA was observed at 2 DAI The levels of iPAs and ZRs were maxima in the embryos at 4 DAP, decreased to a very low level and maintained constant thereafter. Our results provide further evidence that GA(1) plays an important role in the early stages of embryo development and germination. The balance between GA(1) and ABA, rather than their absolute contents, controls these processes throughout the development, whereas iPAs and ZRs may play important roles in early embryogenesis. The use of isolated embryos as starting material avoids the usual interferences with other tissues such as the endosperm. In addition, this is the first report dealing with the hormonal balance of early-embryos in rice.展开更多
Mangrove endophytic fungus 1893 was isolated from Kandelia candel from an estuarine mangrove on the South China Sea Coast Two new lactones 1893A and 1893B, together with other known compounds, have been isolated from ...Mangrove endophytic fungus 1893 was isolated from Kandelia candel from an estuarine mangrove on the South China Sea Coast Two new lactones 1893A and 1893B, together with other known compounds, have been isolated from its fermentation broth. To classify the endophyte correctly for further industrial application, a combination of morphological and molecular techniques was used to approach its identity. The endophyte was compared with similar species having trichogynes or trichogyne-like hyphae which apparently fused with an- theridium-like hyphae, and perithecia initials developing from an ascogonial coil surrounded by enveloping hyphae in early developmental stages on pure culture. Further morphological characteristics on host and non-host were used for comparison with similar species when the endophyte was cultivated on leaves ofKandelia candel and Mangifera indica, respectively, which resulted in classifying the endophyte as a Phomopsis specics. The ITS sequence of rDNA was used to infer its phylogenetic relationships with Phomopsis species that resembled the strain in morphology or ecology. Finally, the endophyte was identified as Diaporthe phaseolorum var. sojae based on morphological and molecular evidence. Our study is a first report ofDiaporthephaseolorum var. sojae isolated from mangrove Kandelia candel.展开更多
The oligosaccharide elicitor from the mycelial wall of an endophytic Colletotrichum sp. B501 promoted the production of artemisinin in Artemisia annua L. hairy root culture. When hairy roots of 22-day-old cultures (la...The oligosaccharide elicitor from the mycelial wall of an endophytic Colletotrichum sp. B501 promoted the production of artemisinin in Artemisia annua L. hairy root culture. When hairy roots of 22-day-old cultures (later growth phase) were exposed to the elicitor (20 mg/L) for 4 d, the maximum content of artemisinin reached 1.15 mg/g, a 64.29% increment over the control. The electron X-ray microanalysis disclosed the rapid accumulation of Ca 2+ in the elicited cortical cells of hairy root. The electronic microscope observation revealed the high electron density area in vacuole of elicited cells. During the first day of elicitation the peroxidase activity of hairy roots was improved sharply. Some cellular morphological changes including cell shrinkage, condensation of cytoplasm and nuclear fragmentation, coincident with the appearance of DNA ladders, were observed after the third day of elicitation. It was suggested that the oligosaccharide elicitor triggered the programmed cell death, which may provide the substance or chemical signal for artemisinin biosynthesis.展开更多
With the identification of more than a dozen novel Hermansky-Pudlak Syndrome （HPS） proteins in vesicle trafficking in higher eukaryotes, a new class of trafficking pathways has been described. It mainly consists of ...With the identification of more than a dozen novel Hermansky-Pudlak Syndrome （HPS） proteins in vesicle trafficking in higher eukaryotes, a new class of trafficking pathways has been described. It mainly consists of three newly-defined protein com- plexes, BLOC-l, -2, and -3. Compelling evidence indicates that these complexes together with two other well-known complexes, AP3 and HOPS, play important roles in endosomal transport. The interactions between these complexes form a network in protein trafficking via endosomes and cytoskeleton. Each node of this network has intra-complex and extra-complex interactions. These complexes are connected by direct interactions between the subunits from different complexes or by indirect interactions through coupling nodes that interact with two or more subunits from different complexes. The dissection of this network facilitates the understanding of a dynamic but elaborate transport machinery in protein/membrane trafficking. The disruption of this network may lead to abnormal trafficking or defective organellar development as described in patients with Hermansky-Pudlak syndrome.展开更多
Microshoots of Castanea mollissima cv.＇yanshanhong＇ in vitro acquired an enhanced rooting capability with increasing numbers of subculture.In this study,we investigated the effect of successive subculture on adventi...Microshoots of Castanea mollissima cv.＇yanshanhong＇ in vitro acquired an enhanced rooting capability with increasing numbers of subculture.In this study,we investigated the effect of successive subculture on adventitious root formation in vitro by the determination of the endogenous hormone level and the enzyme activity.The levels of indoleacetic acid（IAA）,abscisic acid（ABA）,cytokinins（CTK） and gibberellic acid（GA3） were determined by high performance liquid chromatography（HPLC）,and the activities of indoleacetic acid oxidase（IAAO）,peroxidase oxidase（POD）,and polyphenol oxidase（PPO） were measured by ultraviolet-spectrophotometer assay after the induction of rooting at 2nd,4th,6th and 8th subculture.The relationships between physiological characteristics and subculture numbers or rooting rate were as follows：The levels of endogenous IAA in microshoots gradually increased,and endogenous levels of ABA,CTK and GA3 in microshoots decreased slightly after serial subcultures.The level of IAA was highly correlated with subculture numbers and rooting rates.The ratios of IAA/ABA and IAA/CTK both acutely raised with increasing rooting rate during successive subcultures and had high correlations with rooting rate.The activity of IAAO and POD are significantly negatively related with subculture numbers,and the activity of PPO increased after subcultures.展开更多
AIM： TO investigate the significance of angiopoietins, Tie2 and vascular endothelial growth factor （VEGF） expression in the angiogenesis and progress of hepatocellular carcinoma （HCC）. METHODS： Fresh surgically ...AIM： TO investigate the significance of angiopoietins, Tie2 and vascular endothelial growth factor （VEGF） expression in the angiogenesis and progress of hepatocellular carcinoma （HCC）. METHODS： Fresh surgically resected specimens of HCC and noncancerous liver （NCL） tissue from 38 patients with HCC were obtained, and expression of angiopoietin-1 （Ang-1）, angiopoietin-2 （Ang-2）, Tie2, and VEGF messenger RNA （mRNA） was examined by real-time quantitative reverse transcription-polymerase chain reaction （RT-PCR）. Expression pattern of each gene in HCC and NCL tissue specimens was compared and the potential role and interaction in angiogenesis of HCC were analyzed. Genes＇ expression level and its relationship with tumor＇s clinicopathological parameters were also investigated. Immunohistochemical staining of CD34 was performed to determine the microvessel density （MVD） and Ang-2/Ang-1 ratio was calculated. Relationships between Ang-2/Ang-1 ratio, VEGF and MVD and clinicopathological features were also tested so as to evaluate their significance in the progression of HCC. RESULTS： Ang-2 and VEGF mRNAs in HCC were significantly higher than those in NCL tissue （P 〈 0.05）, whereas the Ang-1 and Tie2 mRNAs showed no statistical significance （P 〉 0.05）, though slightly lower level of Ang-1 mRNA in HCC was observed. Ang-2/ Ang-1 ratio and VEGF were both positively correlated to MVD. The Ang-2/Ang-1 ratio, Ang-2 and VEGF were all associated with tumor＇s clinicopathological parameters （P 〈 0.05） except for histological grades （P 〉 0.05）. Ang-1 and Tie2 levels in different clinicopathological groups were not significantly different （P 〉 0.05）. CONCLUSION： Dominant Ang-2 expression against Ang-1 through Tie2 receptor in the presence of VEGF plays a critical role in initiating early neovascularization and transformation of noncancerous liver to hepatocellular carcinoma. Its consequently constant operation in formed HCC induces further angiogenesis and progression of HCC.展开更多
AIM： To evaluate whether urokinase perfusion of non-heart-beating cadaveric donor livers reduces the incidence of intrahepatic ischemic-type biliary lesions （IITBLs）. METHODS： A prospective study was conducted to ...AIM： To evaluate whether urokinase perfusion of non-heart-beating cadaveric donor livers reduces the incidence of intrahepatic ischemic-type biliary lesions （IITBLs）. METHODS： A prospective study was conducted to investigate potential microthrombosis in biliary microcirculation when non-heart-beating cadaveric livers were under warm or cold ischemic conditions. The experimental group included 140 patients who underwent liver transplantation during the period of January 2006 to December 2007, and survived for more than 1 year. The control group included 220 patients who received liver transplantation between July 1999 and December 2005 and survived for more than 1 year. In the experimental group, the arterial system of the donor liver was perfused twice with urokinase during cold perfusion and after trimming of the donor liver. The incidence of IITBLs was compared between the two groups. RESULTS： In the control group, the incidence of IITBLs was 5.9% （13/220 cases） after 3-11 mo of transplantation. In the experimental group, two recipients （1.4%） developed IITBLs at 3 and 6 mo after transplantation, respectively. The difference in the incidence between the two groups was statistically significant （P 〈 0.05）. CONCLUSION： Double from non-heart-beating perfusion of cadaveric livers donors with urokinase may reduce the incidence of IITBLs.展开更多
Objective: To observe the inhibition of intracranial glioma tumorigenesis by vascular endothelial growth factor (VEGF) antisense oligodeoxynucleotide (ODN) in rats. Methods: Totally 20 μ1 Hank's liquid containing...Objective: To observe the inhibition of intracranial glioma tumorigenesis by vascular endothelial growth factor (VEGF) antisense oligodeoxynucleotide (ODN) in rats. Methods: Totally 20 μ1 Hank's liquid containing 1×106 C6 glioma cells was seeded into rat right caudate putaraen in high-flow microinfusion with stereotactic technique. VEGF antisense ODN was simultaneously used with glioma cell. Each rat of the treated group Ⅰ and the treated group Ⅱ was treated with 1 000 μmol/L VEGF antisense ODN. Each rat of the treated group Ⅲ and the treated group Ⅳ was treated with 2 000 μmol/L VEGF antisense ODN. The experimental periods of the treated group Ⅰ , the treated group Ⅲ and the control group Ⅰ were 2 weeks, those of the treated group Ⅱ , the treated group Ⅳ and the control group Ⅱ were 3 weeks. Before sacrifice, MRI was performed on each rat. Tumor magnitude and pathologic examination were detected after samples were dissected. Results: The survival state of all treated rats was better, and that of the control rats was in severe danger. The tumor volumes of the treated group Ⅰ and the treated group Ⅱ were remarkably lessened. Tumor tissue could not be found macroscopically in the brain samples of the treated group Ⅲ and the treated group Ⅳ, but tumor nest could be found with microscopy. Tumors of the treated group I and the treated group Ⅱ had weak expressions of VEGF mRNA and VEGF, while normal brains and the samples of the treated group Ⅲ and the treated group Ⅳ had negative expressions, but tumors of the control groups had strong expressions. Conclusion: VEGF antisense ODN used early in situ can suppress angiogenesis and growth of rat intracranial glioma to retard tumorigenesis.展开更多
This paper presents a KIVA-3 code based numerical model for three-dimensional transient intake flow in the intake port-valve-cylinder system of internal combustion engine using body-fitted technique, which can be used...This paper presents a KIVA-3 code based numerical model for three-dimensional transient intake flow in the intake port-valve-cylinder system of internal combustion engine using body-fitted technique, which can be used in numerical study on internal combustion engine with vertical and inclined valves, and has higher calculation precision. A numerical simulation (on the intake process of a two-valve engine with a semi-sphere combustion chamber and a radial intake port) is provided for analysis of the velocity field and pressure field of different plane at different crank angles. The results revealed the formation of the tumble motion, the evolution of flow field parameters and the variation of tumble ratios as important information for the design of engine in-take system.展开更多
Although VEGFR-3 deficiency disrupts blood vascular development during early embryogenesis, the underlying mechanism was not clear. To characterize its function in angiogenesis and lymphangiogenesis, we employed two g...Although VEGFR-3 deficiency disrupts blood vascular development during early embryogenesis, the underlying mechanism was not clear. To characterize its function in angiogenesis and lymphangiogenesis, we employed two genetically modified mouse models in this study, targeting the coding region for the ligand-binding domain （Vegfr△LBD） or the tyrosine kinase domain with an inactivation point mutation （Vegfr3^TKmat）. We show that lymphatic growth was disrupted in Vegfr3△LBD/△LBD and Vegfr3^TKmut3^TKmat mice, but blood vessels developed normally in both embryo and yolk sac. Interestingly, in Vegfr3△LBD/△LBD but not Vegfr3^TKmut3^TKmat mice, lymph sac was present but there was lack of iym- phangiogenic sprouting. We further demonstrate that both the wild-type and mutant forms of VEGFR-3 could form heterodimers with VEGFR-2, and decreased the level of phospho-VEGFR-2 and the downstream phospho-Erk1/2 in endothelial cells when they were treated with VEGF-A. These findings indicate that signaling mediated via VEGFR-3 activation by its cognate ligands （VEGF-C/-D） is not required for angiogenesis, and that VEGFR-3 may play a role in this process by modulating VEGFR-2-mediated signals.展开更多
Traditional opinion considers that natural resources play an important positive role in economic development, while resource curse theory holds that natural resources usually obstruct economic increase. This debate ne...Traditional opinion considers that natural resources play an important positive role in economic development, while resource curse theory holds that natural resources usually obstruct economic increase. This debate needs further exploration. In most of empirical studies on resource curse theory, the economic development of an area is mainly evaluated by the Gross Domestic Product(GDP), however, the social and cultural contents of economic development are seldom considered. Thus, the Human Developing Index(HDI) was chosen to describe the comprehensive developing situation of an area in our study. Based on the panel data from the year of 2000 to 2011, the relationship between Human Developing Index and resource exploitation degree(RED) of 30 provinces in China(Tibet, Taiwan, Hong Kong and Macao were not included because of the restriction of data acquisition) was investigated by correlation coefficient analysis and regression analysis. We found that resource curse did exist over the entire country and its effect on 30 provinces were not exactly the same. According to the effects of resource curse, these provinces could be classified into four types: no resource curse provinces, slight resource curse provinces, severe resource curse provinces, and extreme resource curse provinces. Testing from two short time periods 2000–2005, and 2006–2011, the resource curse effect was not prominent. However, testing from the entire period of 2000–2011, the effect was obvious among each province.展开更多
Social capital has played an increasingly important role in regional development.China is a country with high stocks of social capital.Using several different indicators of social capital,this study tries to research ...Social capital has played an increasingly important role in regional development.China is a country with high stocks of social capital.Using several different indicators of social capital,this study tries to research the regional disparities in social capital and the influence of social capital on economic growth of China in 1978-2004.Measuring social capital with indicators of associations,charities and blood donation rates,this study finds significant regional disparities in social capital at provincial level in China.Those indicators for social capital are highly correlated with regional economic performance.Statistical analysis shows that social capital has a significant and positive effect on a long-term provincial economic growth.This relationship exists after controlling policy,macro location factors,and per capita GDP in the initial year.The empirical findings indicate that institutions,culture and social relations are critical for regional development in China.Therefore,the creation and support of social capital should be paid more attention to when making regional policy.展开更多
Fermentation experiments to produce validamycins from crude substrates by Streptomyces hygroscopicus were carried out in an external-loop airlift bioreactor (0.0115 m^3 ) with a low ratio of height to diameter of the ...Fermentation experiments to produce validamycins from crude substrates by Streptomyces hygroscopicus were carried out in an external-loop airlift bioreactor (0.0115 m^3 ) with a low ratio of height to diameter of the riser of 2.9 and a ratio of riser to downcomer diameter of 6.6. The influences of gas flow rate and liquid volume on fermentation of validamycins were investigated. Comparisons of validamycin fermentation were made among the external-loop airlift bioreactor, a mechanically stirred tank bioreactor (0.010m^3 ) and shaking flasks. Under the same operation conditions including fermentation medium composition, inoculum ratio and culture temperature, the fermentation time in the external-loop airlift bioreactor (45 h) was shorter than that in the shaking flasks (100 h) and the same as that in the mechanically stirred tank bioreactor. After a total fermentation time of 45 h under optimized operation conditions, average validamycin concentration obtained in the external-loop airlift bioreactor was close to 19630 μg·ml^-1 validamycin concentration in the mechanically stirred tank bioreactor. It was demonstrated that the external-loop airlift bioreactor could substitute for the mechanically stirred tank bioreactor in production of validamycins from crude substrates with dregs by Streptomyces hygroscopicus.展开更多
Advances in molecular cell biology over the last de- cade have clarified the mechanisms involved in can- cer growth, invasion, and metastasis, and enabled the development of molecular-targeted agents. To date, sorafen...Advances in molecular cell biology over the last de- cade have clarified the mechanisms involved in can- cer growth, invasion, and metastasis, and enabled the development of molecular-targeted agents. To date, sorafenib is the only molecular-targeted agent whose survival benefit has been demonstrated in two global phase 111 randomized controlled trials, and has been approved worldwide. Phase 111 clinical trials of other molecular targeted agents comparing them with sorafenib as first-line treatment agents are ongoing. Those agents target the vascular endothelial growth factor, platelet-derived growth factor receptors, as well as target the epidermal growth factor receptor, insulin- like growth factor receptor and mammalian target of rapamycin, in addition to other molecules targeting other components of the signal transduction pathways. In addition, the combination of sorafenib with standard treatment, such as resection, ablation, transarterial em- bolization, and hepatic arterial infusion chemotherapy are ongoing. This review outlines the main pathways involved in the development and progression of hepato- cellular carcinoma and the new agents that target these pathways. Finally, the current statuses of clinical trials of new agents or combination therapy with sorafenib and standard treatment will also be discussed.展开更多
Thymidine phosphorylase (TP) is a key enzyme that contributes to the composition and decomposition of pyrimidine nucleotides. TP seems homologous to platelet-derived endothelial cell growth factor, and its effects on ...Thymidine phosphorylase (TP) is a key enzyme that contributes to the composition and decomposition of pyrimidine nucleotides. TP seems homologous to platelet-derived endothelial cell growth factor, and its effects on inducing vascularization and anti-apoptosis are closely related to growth and metastasis of colorectal carcinoma. In addition, TP is a key enzyme that catalyzes the transformation from 5-fluorouracil (FU) prodrugs of 5′-deoxy-5-fluorouridine (5′- DFUR) to 5-FU. The activity of TP is closely related to the sensitivity of colorectal carcinoma cells to fluorouracil drugs and targeted therapy. Given the important functions of TP in growth, metastasis, tumor treatment, and prognosis, determining its expression mechanism is significant. This article summarizes the research development of TP expression in colorectal carcinoma, tumor neovascularization, cytotoxicity activation of 5′-DFUR, and colorectal carcinoma therapy.展开更多
Bacillus amyloliquefaciens 4-3 is an excellent plant endophyte that can be used as a good raw material for microecological preparations.For this reason,it is important to optimize the culture conditions of this strain...Bacillus amyloliquefaciens 4-3 is an excellent plant endophyte that can be used as a good raw material for microecological preparations.For this reason,it is important to optimize the culture conditions of this strain.The number of viable bacteria of strain 4-3 in this study was the evaluation index,and the culture conditions of the liquid fermentation were optimized by single factor experiment.The optimized culture condition was as follows:incubating temperature 32°C,initial pH value 7.2,rotation speed 220 r/min,inoculum concentration 3%and incubating 56 h,under which higher concentrations of Bacillus amyloliquefaciens could be obtained.展开更多
Five cases of arytenoid dislocation after intubation under general anesthesia are reported in this article. The anatomical and anesthetic causes of this complication were studied restrospectively, and the methods of t...Five cases of arytenoid dislocation after intubation under general anesthesia are reported in this article. The anatomical and anesthetic causes of this complication were studied restrospectively, and the methods of treatment were discussed. The result showed that the incidence of arytenoid dislocation was about 0. 09% (5/5 826). Hoarseness, dysphonia and difficulty in feeding were the prevalent symptoms, and poor mobili- ty of the vocal fold was the most common sign. The treatment included closed reduction of the displaced arytenoid under local anesthesia, steroid and physical therapy. The possible causes of arytenoid dislocation were summarized as follows: (1) trauma produced by the blade tip of laryngoscope, (2) the use of stylet, (3) overstretching of aryepiglottic fold and vocal cord during laryngoscopy and intubation, and (4) cough- ing and movement of the endotracheal tube on the larynx during the endotracheal tube in place. It was sug- gested that correct technique and gentle manipulation during intubation could reduce the incidence of the complication. Timely postoperative follow-up and early reduction of arytenoid cartilage should be empha-sized in the diagnosis and treatment of the complication.展开更多
The term "hemangioma" refers to the common tumor of infancy that exhibits rapid postnatal growth and slow regression during childhood. It may cause confusion with venous malformations that are often incorrec...The term "hemangioma" refers to the common tumor of infancy that exhibits rapid postnatal growth and slow regression during childhood. It may cause confusion with venous malformations that are often incorrectly called "cavernous hemangioma". Venous malformations comprise abnormally formed channels that are lined by quiescent endothelium. Accurate diagnosis is required for selecting the appropriate treatment.展开更多
文摘Fluctuations of levels of several endogenous plant hormones in isolated rice ( Oryza sativa ssp. japonica) embryos during early and mid-embryogenesis and early stages of germination were studied by enzyme-linked immunosorbent assay (ELISA). Embryos were collected at different days after pollination (DAP) and different days after imbibition (DAI) of mature seeds. The contents of gibberellin(1) (GA(1)), abscisic acid (ABA), isopentenyladenine and isopentenyladenosine ( iPAs), zeatin and zeatin riboside ( ZRs) were immunochemically assayed. The GA(1) level was the highest among all hormones tested. The variations of GA(1) levels were opposite with the ABA levels, with some exceptions. During early and mid-embryogenesis, the levels of GA(1) and ABA were the highest at 4 DAP. From 8 to 18 DAP, GA(1) level declined, whereas the ABA level increased. During germination, GA(1) level increased at 2 DAI whereas simultaneously the ABA content decreased. The highest ratio of GA(1)/ABA was observed at 2 DAI The levels of iPAs and ZRs were maxima in the embryos at 4 DAP, decreased to a very low level and maintained constant thereafter. Our results provide further evidence that GA(1) plays an important role in the early stages of embryo development and germination. The balance between GA(1) and ABA, rather than their absolute contents, controls these processes throughout the development, whereas iPAs and ZRs may play important roles in early embryogenesis. The use of isolated embryos as starting material avoids the usual interferences with other tissues such as the endosperm. In addition, this is the first report dealing with the hormonal balance of early-embryos in rice.
基金supported partly by the Guangzhou Natural Science Foundation (Grant No.2007Z3-EO581)the Guangdong Provincial Natural Science Foundation (Grant No.2007A0200300001-7)+1 种基金the Chinese High-Tech 863 Project (Grant No.2006AA09Z422)the National Natural Science Foundation of China(Grant No. 20572136).
文摘Mangrove endophytic fungus 1893 was isolated from Kandelia candel from an estuarine mangrove on the South China Sea Coast Two new lactones 1893A and 1893B, together with other known compounds, have been isolated from its fermentation broth. To classify the endophyte correctly for further industrial application, a combination of morphological and molecular techniques was used to approach its identity. The endophyte was compared with similar species having trichogynes or trichogyne-like hyphae which apparently fused with an- theridium-like hyphae, and perithecia initials developing from an ascogonial coil surrounded by enveloping hyphae in early developmental stages on pure culture. Further morphological characteristics on host and non-host were used for comparison with similar species when the endophyte was cultivated on leaves ofKandelia candel and Mangifera indica, respectively, which resulted in classifying the endophyte as a Phomopsis specics. The ITS sequence of rDNA was used to infer its phylogenetic relationships with Phomopsis species that resembled the strain in morphology or ecology. Finally, the endophyte was identified as Diaporthe phaseolorum var. sojae based on morphological and molecular evidence. Our study is a first report ofDiaporthephaseolorum var. sojae isolated from mangrove Kandelia candel.
文摘The oligosaccharide elicitor from the mycelial wall of an endophytic Colletotrichum sp. B501 promoted the production of artemisinin in Artemisia annua L. hairy root culture. When hairy roots of 22-day-old cultures (later growth phase) were exposed to the elicitor (20 mg/L) for 4 d, the maximum content of artemisinin reached 1.15 mg/g, a 64.29% increment over the control. The electron X-ray microanalysis disclosed the rapid accumulation of Ca 2+ in the elicited cortical cells of hairy root. The electronic microscope observation revealed the high electron density area in vacuole of elicited cells. During the first day of elicitation the peroxidase activity of hairy roots was improved sharply. Some cellular morphological changes including cell shrinkage, condensation of cytoplasm and nuclear fragmentation, coincident with the appearance of DNA ladders, were observed after the third day of elicitation. It was suggested that the oligosaccharide elicitor triggered the programmed cell death, which may provide the substance or chemical signal for artemisinin biosynthesis.
基金This work was supported in part by the National Science Fund for Distinguished Young Scholars (No. 30525007)National Basic Research Program of China (No. 2006CB504103+1 种基金 No. 2006CB500704)Hi-Tech Research and Development Program of China (No. 2006AA02Z322)
文摘With the identification of more than a dozen novel Hermansky-Pudlak Syndrome （HPS） proteins in vesicle trafficking in higher eukaryotes, a new class of trafficking pathways has been described. It mainly consists of three newly-defined protein com- plexes, BLOC-l, -2, and -3. Compelling evidence indicates that these complexes together with two other well-known complexes, AP3 and HOPS, play important roles in endosomal transport. The interactions between these complexes form a network in protein trafficking via endosomes and cytoskeleton. Each node of this network has intra-complex and extra-complex interactions. These complexes are connected by direct interactions between the subunits from different complexes or by indirect interactions through coupling nodes that interact with two or more subunits from different complexes. The dissection of this network facilitates the understanding of a dynamic but elaborate transport machinery in protein/membrane trafficking. The disruption of this network may lead to abnormal trafficking or defective organellar development as described in patients with Hermansky-Pudlak syndrome.
基金supported by Special Scientific Research Fund for Doctor Subjects of Universities(NO20060022010)China National key Tech R&D Program (No2006BAD18B0202)
文摘Microshoots of Castanea mollissima cv.＇yanshanhong＇ in vitro acquired an enhanced rooting capability with increasing numbers of subculture.In this study,we investigated the effect of successive subculture on adventitious root formation in vitro by the determination of the endogenous hormone level and the enzyme activity.The levels of indoleacetic acid（IAA）,abscisic acid（ABA）,cytokinins（CTK） and gibberellic acid（GA3） were determined by high performance liquid chromatography（HPLC）,and the activities of indoleacetic acid oxidase（IAAO）,peroxidase oxidase（POD）,and polyphenol oxidase（PPO） were measured by ultraviolet-spectrophotometer assay after the induction of rooting at 2nd,4th,6th and 8th subculture.The relationships between physiological characteristics and subculture numbers or rooting rate were as follows：The levels of endogenous IAA in microshoots gradually increased,and endogenous levels of ABA,CTK and GA3 in microshoots decreased slightly after serial subcultures.The level of IAA was highly correlated with subculture numbers and rooting rates.The ratios of IAA/ABA and IAA/CTK both acutely raised with increasing rooting rate during successive subcultures and had high correlations with rooting rate.The activity of IAAO and POD are significantly negatively related with subculture numbers,and the activity of PPO increased after subcultures.
文摘AIM： TO investigate the significance of angiopoietins, Tie2 and vascular endothelial growth factor （VEGF） expression in the angiogenesis and progress of hepatocellular carcinoma （HCC）. METHODS： Fresh surgically resected specimens of HCC and noncancerous liver （NCL） tissue from 38 patients with HCC were obtained, and expression of angiopoietin-1 （Ang-1）, angiopoietin-2 （Ang-2）, Tie2, and VEGF messenger RNA （mRNA） was examined by real-time quantitative reverse transcription-polymerase chain reaction （RT-PCR）. Expression pattern of each gene in HCC and NCL tissue specimens was compared and the potential role and interaction in angiogenesis of HCC were analyzed. Genes＇ expression level and its relationship with tumor＇s clinicopathological parameters were also investigated. Immunohistochemical staining of CD34 was performed to determine the microvessel density （MVD） and Ang-2/Ang-1 ratio was calculated. Relationships between Ang-2/Ang-1 ratio, VEGF and MVD and clinicopathological features were also tested so as to evaluate their significance in the progression of HCC. RESULTS： Ang-2 and VEGF mRNAs in HCC were significantly higher than those in NCL tissue （P 〈 0.05）, whereas the Ang-1 and Tie2 mRNAs showed no statistical significance （P 〉 0.05）, though slightly lower level of Ang-1 mRNA in HCC was observed. Ang-2/ Ang-1 ratio and VEGF were both positively correlated to MVD. The Ang-2/Ang-1 ratio, Ang-2 and VEGF were all associated with tumor＇s clinicopathological parameters （P 〈 0.05） except for histological grades （P 〉 0.05）. Ang-1 and Tie2 levels in different clinicopathological groups were not significantly different （P 〉 0.05）. CONCLUSION： Dominant Ang-2 expression against Ang-1 through Tie2 receptor in the presence of VEGF plays a critical role in initiating early neovascularization and transformation of noncancerous liver to hepatocellular carcinoma. Its consequently constant operation in formed HCC induces further angiogenesis and progression of HCC.
文摘AIM： To evaluate whether urokinase perfusion of non-heart-beating cadaveric donor livers reduces the incidence of intrahepatic ischemic-type biliary lesions （IITBLs）. METHODS： A prospective study was conducted to investigate potential microthrombosis in biliary microcirculation when non-heart-beating cadaveric livers were under warm or cold ischemic conditions. The experimental group included 140 patients who underwent liver transplantation during the period of January 2006 to December 2007, and survived for more than 1 year. The control group included 220 patients who received liver transplantation between July 1999 and December 2005 and survived for more than 1 year. In the experimental group, the arterial system of the donor liver was perfused twice with urokinase during cold perfusion and after trimming of the donor liver. The incidence of IITBLs was compared between the two groups. RESULTS： In the control group, the incidence of IITBLs was 5.9% （13/220 cases） after 3-11 mo of transplantation. In the experimental group, two recipients （1.4%） developed IITBLs at 3 and 6 mo after transplantation, respectively. The difference in the incidence between the two groups was statistically significant （P 〈 0.05）. CONCLUSION： Double from non-heart-beating perfusion of cadaveric livers donors with urokinase may reduce the incidence of IITBLs.
文摘Objective: To observe the inhibition of intracranial glioma tumorigenesis by vascular endothelial growth factor (VEGF) antisense oligodeoxynucleotide (ODN) in rats. Methods: Totally 20 μ1 Hank's liquid containing 1×106 C6 glioma cells was seeded into rat right caudate putaraen in high-flow microinfusion with stereotactic technique. VEGF antisense ODN was simultaneously used with glioma cell. Each rat of the treated group Ⅰ and the treated group Ⅱ was treated with 1 000 μmol/L VEGF antisense ODN. Each rat of the treated group Ⅲ and the treated group Ⅳ was treated with 2 000 μmol/L VEGF antisense ODN. The experimental periods of the treated group Ⅰ , the treated group Ⅲ and the control group Ⅰ were 2 weeks, those of the treated group Ⅱ , the treated group Ⅳ and the control group Ⅱ were 3 weeks. Before sacrifice, MRI was performed on each rat. Tumor magnitude and pathologic examination were detected after samples were dissected. Results: The survival state of all treated rats was better, and that of the control rats was in severe danger. The tumor volumes of the treated group Ⅰ and the treated group Ⅱ were remarkably lessened. Tumor tissue could not be found macroscopically in the brain samples of the treated group Ⅲ and the treated group Ⅳ, but tumor nest could be found with microscopy. Tumors of the treated group I and the treated group Ⅱ had weak expressions of VEGF mRNA and VEGF, while normal brains and the samples of the treated group Ⅲ and the treated group Ⅳ had negative expressions, but tumors of the control groups had strong expressions. Conclusion: VEGF antisense ODN used early in situ can suppress angiogenesis and growth of rat intracranial glioma to retard tumorigenesis.
文摘This paper presents a KIVA-3 code based numerical model for three-dimensional transient intake flow in the intake port-valve-cylinder system of internal combustion engine using body-fitted technique, which can be used in numerical study on internal combustion engine with vertical and inclined valves, and has higher calculation precision. A numerical simulation (on the intake process of a two-valve engine with a semi-sphere combustion chamber and a radial intake port) is provided for analysis of the velocity field and pressure field of different plane at different crank angles. The results revealed the formation of the tumble motion, the evolution of flow field parameters and the variation of tumble ratios as important information for the design of engine in-take system.
基金Acknowledgments We thank Dr Lena Claesson-Welsh （Uppsala University）, and PIs of Model Animal Research Center （MARC, Nanjing University） for the helpful discussion about the work, and Yanlan Cao, Wenting Shi and all the staff in the MARC Animal facility of Nanjing University for excellent technical assistance. This work wasfinancially supported by grants from the National Natural Science Foundation of China （30771069, 30671038, and 30930028）, the Ministry of Science and Technology of China （2006CB943500）, and the Ministry of Education of China （NCET： Program for New Century Excellent Talents in University）.
文摘Although VEGFR-3 deficiency disrupts blood vascular development during early embryogenesis, the underlying mechanism was not clear. To characterize its function in angiogenesis and lymphangiogenesis, we employed two genetically modified mouse models in this study, targeting the coding region for the ligand-binding domain （Vegfr△LBD） or the tyrosine kinase domain with an inactivation point mutation （Vegfr3^TKmat）. We show that lymphatic growth was disrupted in Vegfr3△LBD/△LBD and Vegfr3^TKmut3^TKmat mice, but blood vessels developed normally in both embryo and yolk sac. Interestingly, in Vegfr3△LBD/△LBD but not Vegfr3^TKmut3^TKmat mice, lymph sac was present but there was lack of iym- phangiogenic sprouting. We further demonstrate that both the wild-type and mutant forms of VEGFR-3 could form heterodimers with VEGFR-2, and decreased the level of phospho-VEGFR-2 and the downstream phospho-Erk1/2 in endothelial cells when they were treated with VEGF-A. These findings indicate that signaling mediated via VEGFR-3 activation by its cognate ligands （VEGF-C/-D） is not required for angiogenesis, and that VEGFR-3 may play a role in this process by modulating VEGFR-2-mediated signals.
基金Under the auspices of Specialized Research Fund for Doctoral Program of Higher Education of China(No.20120043110012)Fundamental Research Funds for Central Universities(No.12SSXT109)
文摘Traditional opinion considers that natural resources play an important positive role in economic development, while resource curse theory holds that natural resources usually obstruct economic increase. This debate needs further exploration. In most of empirical studies on resource curse theory, the economic development of an area is mainly evaluated by the Gross Domestic Product(GDP), however, the social and cultural contents of economic development are seldom considered. Thus, the Human Developing Index(HDI) was chosen to describe the comprehensive developing situation of an area in our study. Based on the panel data from the year of 2000 to 2011, the relationship between Human Developing Index and resource exploitation degree(RED) of 30 provinces in China(Tibet, Taiwan, Hong Kong and Macao were not included because of the restriction of data acquisition) was investigated by correlation coefficient analysis and regression analysis. We found that resource curse did exist over the entire country and its effect on 30 provinces were not exactly the same. According to the effects of resource curse, these provinces could be classified into four types: no resource curse provinces, slight resource curse provinces, severe resource curse provinces, and extreme resource curse provinces. Testing from two short time periods 2000–2005, and 2006–2011, the resource curse effect was not prominent. However, testing from the entire period of 2000–2011, the effect was obvious among each province.
基金Under the auspices of National Natural Science Foundation of China(No.40871065,40830747)
文摘Social capital has played an increasingly important role in regional development.China is a country with high stocks of social capital.Using several different indicators of social capital,this study tries to research the regional disparities in social capital and the influence of social capital on economic growth of China in 1978-2004.Measuring social capital with indicators of associations,charities and blood donation rates,this study finds significant regional disparities in social capital at provincial level in China.Those indicators for social capital are highly correlated with regional economic performance.Statistical analysis shows that social capital has a significant and positive effect on a long-term provincial economic growth.This relationship exists after controlling policy,macro location factors,and per capita GDP in the initial year.The empirical findings indicate that institutions,culture and social relations are critical for regional development in China.Therefore,the creation and support of social capital should be paid more attention to when making regional policy.
基金Supported by the Natural Science Foundation of Zhejiang Province (No. ZB0106)the National Natural Science Foundation of China (No. 20176055).
文摘Fermentation experiments to produce validamycins from crude substrates by Streptomyces hygroscopicus were carried out in an external-loop airlift bioreactor (0.0115 m^3 ) with a low ratio of height to diameter of the riser of 2.9 and a ratio of riser to downcomer diameter of 6.6. The influences of gas flow rate and liquid volume on fermentation of validamycins were investigated. Comparisons of validamycin fermentation were made among the external-loop airlift bioreactor, a mechanically stirred tank bioreactor (0.010m^3 ) and shaking flasks. Under the same operation conditions including fermentation medium composition, inoculum ratio and culture temperature, the fermentation time in the external-loop airlift bioreactor (45 h) was shorter than that in the shaking flasks (100 h) and the same as that in the mechanically stirred tank bioreactor. After a total fermentation time of 45 h under optimized operation conditions, average validamycin concentration obtained in the external-loop airlift bioreactor was close to 19630 μg·ml^-1 validamycin concentration in the mechanically stirred tank bioreactor. It was demonstrated that the external-loop airlift bioreactor could substitute for the mechanically stirred tank bioreactor in production of validamycins from crude substrates with dregs by Streptomyces hygroscopicus.
文摘Advances in molecular cell biology over the last de- cade have clarified the mechanisms involved in can- cer growth, invasion, and metastasis, and enabled the development of molecular-targeted agents. To date, sorafenib is the only molecular-targeted agent whose survival benefit has been demonstrated in two global phase 111 randomized controlled trials, and has been approved worldwide. Phase 111 clinical trials of other molecular targeted agents comparing them with sorafenib as first-line treatment agents are ongoing. Those agents target the vascular endothelial growth factor, platelet-derived growth factor receptors, as well as target the epidermal growth factor receptor, insulin- like growth factor receptor and mammalian target of rapamycin, in addition to other molecules targeting other components of the signal transduction pathways. In addition, the combination of sorafenib with standard treatment, such as resection, ablation, transarterial em- bolization, and hepatic arterial infusion chemotherapy are ongoing. This review outlines the main pathways involved in the development and progression of hepato- cellular carcinoma and the new agents that target these pathways. Finally, the current statuses of clinical trials of new agents or combination therapy with sorafenib and standard treatment will also be discussed.
文摘Thymidine phosphorylase (TP) is a key enzyme that contributes to the composition and decomposition of pyrimidine nucleotides. TP seems homologous to platelet-derived endothelial cell growth factor, and its effects on inducing vascularization and anti-apoptosis are closely related to growth and metastasis of colorectal carcinoma. In addition, TP is a key enzyme that catalyzes the transformation from 5-fluorouracil (FU) prodrugs of 5′-deoxy-5-fluorouridine (5′- DFUR) to 5-FU. The activity of TP is closely related to the sensitivity of colorectal carcinoma cells to fluorouracil drugs and targeted therapy. Given the important functions of TP in growth, metastasis, tumor treatment, and prognosis, determining its expression mechanism is significant. This article summarizes the research development of TP expression in colorectal carcinoma, tumor neovascularization, cytotoxicity activation of 5′-DFUR, and colorectal carcinoma therapy.
文摘Bacillus amyloliquefaciens 4-3 is an excellent plant endophyte that can be used as a good raw material for microecological preparations.For this reason,it is important to optimize the culture conditions of this strain.The number of viable bacteria of strain 4-3 in this study was the evaluation index,and the culture conditions of the liquid fermentation were optimized by single factor experiment.The optimized culture condition was as follows:incubating temperature 32°C,initial pH value 7.2,rotation speed 220 r/min,inoculum concentration 3%and incubating 56 h,under which higher concentrations of Bacillus amyloliquefaciens could be obtained.
文摘Five cases of arytenoid dislocation after intubation under general anesthesia are reported in this article. The anatomical and anesthetic causes of this complication were studied restrospectively, and the methods of treatment were discussed. The result showed that the incidence of arytenoid dislocation was about 0. 09% (5/5 826). Hoarseness, dysphonia and difficulty in feeding were the prevalent symptoms, and poor mobili- ty of the vocal fold was the most common sign. The treatment included closed reduction of the displaced arytenoid under local anesthesia, steroid and physical therapy. The possible causes of arytenoid dislocation were summarized as follows: (1) trauma produced by the blade tip of laryngoscope, (2) the use of stylet, (3) overstretching of aryepiglottic fold and vocal cord during laryngoscopy and intubation, and (4) cough- ing and movement of the endotracheal tube on the larynx during the endotracheal tube in place. It was sug- gested that correct technique and gentle manipulation during intubation could reduce the incidence of the complication. Timely postoperative follow-up and early reduction of arytenoid cartilage should be empha-sized in the diagnosis and treatment of the complication.
文摘The term "hemangioma" refers to the common tumor of infancy that exhibits rapid postnatal growth and slow regression during childhood. It may cause confusion with venous malformations that are often incorrectly called "cavernous hemangioma". Venous malformations comprise abnormally formed channels that are lined by quiescent endothelium. Accurate diagnosis is required for selecting the appropriate treatment.
