VEGF induces HUVECs to produce extracellular H2O2 and its proliferation role

AIM:To study the effect of VEGF on extracellular H₂O₂ production in HUVECs and the role of H₂O₂ in the VEGF-induced proliferation. METHODS:HUVECs was stimulated with 500 μg/L VEGF. Products of extracellular H₂O₂ was detected by H₂DCFDA staining. MTT method was used to value the influences of 3×10⁶ U/L catalase and 5-20 mmol/L H₂O₂ to VEGF function. RESULTS:After treatment for 15 min with VEGF, HUVECs appeared fluorescence, and continued to become stronger, peaked at 45 min then decreased. HUVECs, which was treated simultaneity with VEGF and 3×10⁶ U/L catalase, only appeared very faint fluorescence. The proliferation of HUVECs by VEGF was restrained when treated with 3×10⁶ U/L catalase. The extrinsic H₂O₂ at concentration of 5-10 mmol/L promoted the proliferation of HUVECs but inhibited the proliferation effect of VEGF on HUVECs (P<0.01). CONCLUSION:These findings indicate that VEGF induces HUVECs to produce extracellular H₂O₂ and plays role in proliferation, but extrinsic H₂O₂ restrains VEGF function.     

Adipocyte-derived relaxing factor,a new vasodilative factor

Although our knowledge of ADRF (adipocyte-derived relaxing factor) is extremely limited,the little that is known has already revealed a promising future in this newly found factor.Firstly,it is secreted by adipose tissue,which is a abundantly and extensively distributed in human body and has become a hot spot for research work in recent years.Secondly,ADRF has shown a significant vasodilative action in a considerable number of experiments conducted on arteries of various sizes,from different body parts of different species of animals,including human.In this article,we introduce the development of ADRF research,sum up its known properties,including its Ca2+,protein tyrosine kinase,and protein kinase A dependent releasing,K+ channel mediated functioning,and interfered effect in different pathological models,and propose problems surrounding this factor and directions for future research work.     

淮河流域(安徽段)主要湿地维管植物研究

淮河流域(安徽段)主要湖泊湿地维管植物有68科165属259种;科、属、种分别占全省维管植物科的30.2%、属的13.4%、种的7.1%。包含5种以上的11个较大科构成了淮河流域湿地植物的主体,其中禾本科和莎草科种类最多。区系分布区类型:蕨类植物主要有4种分布区类型,世界分布为主要类型;种子植物属有14种分布类型,其中温带分布类型占总属数的38.4%,该区湿地维管植物具有典型温带性质。湿地植物资源包括食品类,工业原料类,绿肥类,观赏类,环保类及种质资源类等。     

Anatomical Characteristics of the Formation of Crown Root Primordia in Unelongated Stems of Wheat

Abstract

Anatomical observations were conducted to clarify some characteristics of the crown root primordia (CRP) formation in wheat stems. Unelongated portions of main stems were sampled from the plant at 3.2 and 7.2 plant age in leaf number, which were adopted as indexes because of the similarity to rice plants. Then, serial cross sections were made to investigate the position of CRP in the unelongated stem taking into consideration the running of vascular bundles in the stem. CRP were formed just outside tissues of the peripheral cylinder of longitudinal vascular bundles. The positions of CRP were not successive along the stem axis. They showed no definite relation to the running of vascular bundles. Diameters of CRP at the upper portion of the stems were larger than those at the lower portion. The positions of CRP along the stem axis were not distinguishable into nodal and internodal position. CRP and emerged CRs were not classified by the well-known ‘nodal root’ or ‘shoot unit root’, or the ‘unit’, which have been applied recently to rice plants. Further studies are necessary to clarify the factors controlling CRP formation anatomically and quantitatively.     

Understory plant communities of boreal mixedwood forests in western Canada: Natural patterns and response to variable-retention harvesting

We examined patterns of variation in richness, diversity, and composition of understory vascular plant communities in mixedwood boreal forests of varying composition (broadleaf, mixedwood, conifer) in Alberta, Canada, before and for 2 years following variable-retention harvesting (clearcut, 20 and 75% dispersed green tree retention, control). Broadleaf-dominated forests differed from mixedwood or conifer-dominated forests in that they had greater canopy cover, litter depth, soil nitrogen, warmer soils, as well as greater shrub cover, herb and shrub richness and diversity (plot scale). In contrast, conifer, and to a lesser extent mixedwood, forest had greater β diversity than broadleaf forest. Overall, mixedwood and conifer forests were similar to one another, both differed from broadleaf forest. Several species were found to be significant indicators of broadleaf forest but most of these also occurred in the other forest types. Understory composition was related to canopy composition and edaphic conditions. Variable-retention harvesting had little effect on understory cover, richness, or diversity but resulted in reduced richness and β diversity at a larger scale. The clearcut and 20% treatments affected composition in all forest types. Early successional species and those common in disturbed sites were indicators of harvesting while evergreen, shade-tolerant understory herbs were indicators of the control forest and 75% retention harvest. We conclude that it is important to maintain a range of variation in canopy composition of mixedwood forests in order to conserve the associated understory communities. The presence of conifers in these forests has a particularly important influence on understory communities. The threshold for a lifeboat effect of variable-retention harvesting is between 20 and 75% retention. Examination of richness and β diversity at a variety of scales can provide interesting information on effects of harvesting on spatial reorganization and homogenization of understory plant communities.     

华中神农架箭竹(Fargesia spathacea)群落之海拔多样性(英文)

通过对华中神农架海拔1500米至2600米之间11个箭竹样方的研究,阐述了箭竹群落物种丰富度,物种多样性,物种均匀性,生活型谱及群落类型的海拔变化。从最低样方(1680米)到最高样地(2570米),微管束植物从30种降为7种,服从线性模型:Y=55.991.83X(R2=0.84,P<0.001);物种多样性从3.18降为1.78,服从线性模型:Y=4.670.10X (R2=0.72,P=0.001;物种均匀度在0.83至0.99之间变化,但与海拔并不相关。在生活型谱中,一年生植物,地下芽植物和大高位芽树木的百分比随海拔升高而升高;灌木和中高位芽树木随海拔升高而降低;多年生草本和半灌木与海拔关系不大。箭竹群落可分为5种类型:常绿阔叶林下,落叶阔叶林下,温性针叶林下,寒温性针叶林与混交林下,纯箭竹林。图4表2参19。     

Serum vascular endothelial growth factor in dogs with haemangiosarcoma and haematoma

Splenic haemangiosarcomas are frequently seen in dogs. Because of their bad prognosis differentiation from other benign splenic lesions are of prognostic importance.     

Persistent Hematuria as a Result of Chronic Renal Hypertension Secondary to Nephritis in a Stallion

A 13-year-old Lusitano stallion was referred to our institution with a history of severe hematuria for 8.5 months. The origin of the hematuria was determined to be the left kidney. The diagnostic workup failed to identify obstructive, infectious, or neoplastic conditions. The history and ultrasonographic examination suggested a chronic condition. The stallion was subjected to left nephrectomy because of the persistent hematuria and anemia. A histopathological examination detected lesions, which were compatible with chronic nephritis and vascular renal hypertension. It is hypothesized that changes in the normal parenchymal architecture produced a vascular aberration that led to renal hypertension, with subsequent blood extravasation and hematuria. The horse recovered completely after nephrectomy.     

Expression Pattern of Vascular Endothelial Growth Factor in Canine Folliculogenesis and its Effect on the Growth and Development of Follicles after Ovarian Organ Culture

In this study, the expressions of VEGF in dog follicles were detected by immunohistochemistry and the effects of VEGF treatment on the primordial to primary follicle transition and on subsequent follicle progression were examined using a dog ovary organ culture system. The frozen‐thawed canine ovarian follicles within slices of ovarian cortical tissue were cultured for 7 and 14 days in presence or absence of VEGF. After culture, the ovaries were fixed, sectioned, stained and counted for morphologic analysis. The results showed that VEGF was expressed in the theca cells of antral follicles and in the granulosa cells nearest the oocyte in preantral follicle but not in granulosa cells of primordial and primary follicles; however, the VEGF protein was expressed in CL. After in vitro culture, VEGF caused a decrease in the number of primordial follicles and concomitant increase in the number of primary follicles that showed growth initiation and reached the secondary and preantral stages of development after 7 and 14 days. Follicular viability was also improved in the presence of VEGF after 7 and 14 days in culture. In conclusion, treatment with VEGF was found to promote the activation of primordial follicle development that could provide an alternative approach to stimulate early follicle development in dogs.     

MiRNA－93－5p 对 VEGF 的转录调控及其与梅花鹿茸细胞增殖的关系1）

为了探讨miRNA－93－5p对梅花鹿血管内皮生长因子（ VEGF）的转录调控作用及其与鹿茸细胞生长的关系,分离了鹿茸顶端软骨组织细胞,利用Trizol试剂法提取细胞总RNA,反转录合成cDNA。根据GenBank已发表的相关序列设计梅花鹿VEGF基因的3′端非编码区部分序列（3′UTR）特异引物并进行克隆,构建VEGF基因的3′UTR野生型及其突变体序列双荧光素酶报告基因载体并进行荧光素酶活性检测。再将人工合成的miRNA－93－5p模拟物转染鹿茸软骨细胞,MTT法检测鹿茸细胞体外增殖的变化;Western blotting分析VEGF蛋白的表达丰度。结果表明：成功获得了鹿茸组织VEGF基因的3′UTR序列,野生型序列长度为356 bp,突变体长度为336 bp。荧光素酶活性检测结果表明,转染野生型质粒组细胞荧光素酶活性降低,而转染突变体组细胞荧光素酶活性无明显变化。 MTT法和Western blotting结果显示,鹿茸细胞的体外增殖受到抑制,VEGF蛋白的表达水平下降,且呈时间依赖性。