A Simple Clear Technique in Observing Vascular Development of Grape Ovary

The vascular system of the grapevine (Vitis vinifera L.) flower is a channel for transporting water and nutrients to the ovary. It plays an important role in the development of the ovary and fertilization through pollination. However, the vascular bundles in the flower are so tiny that they are difficult to sample and observe by traditional slicing techniques. In this study, ‘Summer Black’ grape flowers were selected as the test materials, and the tissue samples were treated by the optical clearing technique. After simple compaction, the structure and development of the vasculature were observed by common microscopy, fluorescence microscopy and laser confocal microscopy. The results showed that the transparency effects of 3% NaOH and a saturated trichloroacetaldehyde composite agreed well with the observations of the vascular structure and the developmental process of the flower in different periods. Moreover, the samples after optical clearing could be reconstructed in 3D, which helped us know more about its development and function. According to these observations, the vasculature of the ‘Summer Black’ flower can be divided into ovule vascular bundles, peripheral vascular bundles and central vascular bundles. The peripheral vascular bundles were composed of the first-order vascular bundles and the inferior vascular bundles which branched from the superior vascular bundles. These bundles branched in different directions with no discernible pattern. The two different branching methods were as follows. First, the inferior vascular bundle was directly connected to a superior vascular bundle. Secondly, some of the superior vascular bundles bent in different ways, forming the inferior vascular bundle connecting the superior vascular bundles by a metamorphosed vessel with a triangular shape. In a comparison of the developmental changes in various periods, the growth of vascular bundles at each period was directly proportional to the growth of the flower. Laser confocal scanning was used to explore the three-dimensional morphology of the peripheral vascular bundle and showed that the peripheral vascular bundle of grapes was not completely parallel to the flower’s epidermal cells. As a result, the optical clearing technique was convenient and authentic compared with the traditional slicing operation for tiny flower organs. With these advantages according to the observations, this study provides a feasible technique and useful information for the study of vascular bundle development in grape flower organs.     

檀香吸器维管组织的个体发育

为了解檀香吸器维管组织的发育过程,采用激光共聚焦显微镜、光学显微镜和透射电镜观察檀香吸器维管组织的个体发育。结果表明,檀香维管组织的分化分为两个时期:入侵前和入侵后。吸器维管组织发育始于盘状吸器时期,起源于吸器基部具有分生能力的细胞,后分为两束。侵入前无向顶的分化,处于吸器基部。侵入后随吸管深入寄主根与寄主根维管束连通,形成具有吸收功能的维管组织。成熟吸器维管组织呈倒烧瓶结构,仅处于吸器烧瓶核心两边,由木质部组成而无韧皮部。檀香的吸器维管组织发育有两个因素诱导,一个是遗传因素,另一个为寄主。这些为檀香半寄生性特性研究提供了形态解剖学基础。     

Vascular Bundle Distribution Within Broad Bean Seed Coat and the Structure of Unloading Region

Cytological observations were made on developing seed coat of broad bean (Vicia faba L.) by use of light and electron microscopy. Attention was focused on vascular distribution. The seeds were attached by the funiculus to tile large vascular bundles of pericarp of broad bean. The vascular bundle passed through hilum and two layers of palisade, entered the pa- renchyma of seed coat, then diverged in to two routes. One was a complete vascular bundle composed of both'phloem and xylem elements, it stretched down through seed raphe, then upward and terminated near the radical. The other was a two-recurrent-vascular-bundle with only phloem constitutents, they extended forward detoured the micropyle and extended downward, but did not join with the upward complete vascular bundle. The recurrent vascular bundles branched out many small short branches. The obvious difference between phloem of recurrent vascular bundle and of complete vascular bundle was that the companion ceils of the former did not normally modify to transfer ceils, but connected to the adjoining parenchyma cells through abundant plasmodesmata. It is deduced from the structural analysis that the symplastic route may play an important role, particularly in the region of recurrent vascular bundle, in the course of importing assimilates unloading in seed coat and transporting to the embryo.     

Reactivity of isolated human chorionic vessels: analysis of some influencing variables

The aim of the study was to determine whether 24 h of cold storage of samples, mode of delivery, and gestational age influenced in vitro human chorionic vascular reactivity (35 arteries and 34 veins). The following groups were compared: (i) fresh versus 24-h cold-stored (4 degrees C in Krebs-Henseleit solution) chorionic vascular rings from normal term placentas, (ii) fresh chorionic vascular rings from normal term placentas obtained after vaginal delivery versus those obtained after elective caesarean section, and (iii) fresh chorionic vascular rings from normal term placentas versus those obtained from preterm deliveries. Isometric recording of the concentration-response curve to KCl (5-120 mM) was assessed in each group. In vitro human chorionic vascular reactivity was influenced negatively by the 24-h cold storage of samples, with only 30% of stored samples being weakly reactive to KCl. Human chorionic vascular reactivity to KCl was unaffected by the mode of delivery. However, the response to KCl was gestational-age dependent. Thus, preterm vascular rings exhibited a significantly (P<0.05) decreased response (Emax=9.8 +/- 0.0 mN; EC50=26.0 +/- 1.3 mM) compared with term samples (Emax=21.6 +/- 2 mN; EC50=13.9 +/- 1.6 mM). In conclusion, this study provides evidence that fresh term vascular rings are the tissues of choice for studying human chorionic vascular reactivity.     

根域限制对葡萄果实不同发育期维管束水分运输的影响

本文采用质外体染料示踪法研究了葡萄果实不同发育期根域限制和非根域限制（对照）处理果实维管束水分运输变化。结果表明,在葡萄果实发育的第一次快速生长期,根域限制和对照处理的果实周缘维管束被染色数量最多,染料溶液在葡萄果实中的运输速率也最高,分别为1.72和1.63cm·h-1,根域限制处理果实中周缘维管束和中央维管束中染料溶液的运输速度低于对照处理,但胚珠维管束中染料运输速度要高于对照,为1.32cm·h-1;进入生长停滞期后,根域限制和对照处理的葡萄果实中周缘维管束被染色数目降低,染料溶液在中央维管束中的运输速度分别降低为0.72和0.70cm·h-1;在果实的第二次快速生长期,根域限制和对照处理果实周缘维管束染色数目仍然低于果实发育的第一次快速生长期,根域限制果实周缘维管束染色范围和染料运输速率都高于对照处理。     

Distributions of vascular pressure and resistance in the lung

The low-viscosity bolus method was used to determine the longitudinal distributions of vascular resistance and intravascular pressure with respect to cumulative vascular volume from the lobar artery to the lobar vein in isolated dog lung lobes near functional residual capacity under zone 3 conditions. We found that the resistance distribution had two modes, a larger one upstream and a smaller one downstream from a local minimum. Over the range of vascular pressures studied the total vascular resistance decreased and the vascular volume increased with increasing vascular pressure. However, the shape of the normalized resistance distribution was independent of vascular pressure. Comparisons of the resistance distributions with the distributions of arterial, capillary, and venous volumes suggest that the modes represent regions of relatively high resistance proximal and distal to the capillary bed. These results are consistent with the concept that within the lobar vascular bed the highest resistance per unit blood volume is in the smallest arteries and veins, as suggested by morphometric data from other sources.     

Interaction of myeloperoxidase with vascular NAD(P)H oxidase-derived reactive oxygen species in vasculature: implications for vascular diseases

Vascular NAD(P)H oxidase-derived reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) have emerged as important molecules in the pathogenesis of atherosclerosis, hypertension, and diabetic vascular complications. Additionally, myeloperoxidase (MPO), a transcytosable heme protein that is derived from leukocytes, is also believed to play important roles in the above-mentioned inflammatory vascular diseases. Previous studies have shown that MPO-induced vascular injury responses are H2O2 dependent. It is well known that MPO can use leukocyte-derived H2O2; however, it is unknown whether the vascular-bound MPO can use vascular nonleukocyte oxidase-derived H2O2 to induce vascular injury. In the present study, ANG II was used to stimulate vascular NAD(P)H oxidases and increase their H2O2 production in the vascular wall, and vascular dysfunction was used as the vascular injury parameter. We demonstrated that vascular-bound MPO has sustained activity in the vasculature. MPO could use the vascular NAD(P)H oxidase-derived H2O2 to produce hypochlorus acid (HOCl) and its chlorinating species. More importantly, MPO derived HOCl and chlorinating species amplified the H2O2-induced vascular injury by additional impairment of endothelium-dependent relaxation. HOCl-modified low-density lipoprotein protein (LDL), a specific biomarker for the MPO-HOCl-chlorinating species pathway, was expressed in LDL and MPO-bound vessels with vascular NAD(P)H oxidase-derived H2O2. MPO-vascular NAD(P)H oxidase-HOCl-chlorinating species may represent a common pathogenic pathway in vascular diseases and a new mechanism involved in exacerbation of vascular diseases under inflammatory conditions.     

Exacerbation of vascular endothelial injury in the generalized Shwartzman reaction by the administration of anti-E-selectin antibody

Previously, we reported that the consecutive administration of lipopolysaccharide (LPS) into LPS-sensitized mice for the generalized Shwartzman reaction (GSR) induced systemic injury of vascular endothelial cells. The aim of this study was to investigate the participation of vascular adhesion molecules in the vascular endothelial injury of GSR. The administration of anti-E-selectin antibody in GSR-induced mice resulted in massive apoptosis of vascular endothelial cells and congestion in blood vessels. Further, marked hemorrhage was found in the pulmonary alveoli of those mice. GSR, especially lung injury, was definitely exacerbated by the administration of anti-E-selectin antibody. On the other hand, the administration of anti-VCAM-1 antibody did not induce such injury of vascular endothelial cells. The possible role of E-selectin in the exacerbation of vascular endothelial injury in GSR is discussed.     

miR-375在AGEs介导糖尿病血管损伤细胞中的生物学功能

目的：探讨miR-375在血管损伤细胞中的表达及生物学功能。方法：利用基因克隆技术构建miR-375表达载体;然后将miR-375表达质粒转染至血管损伤细胞中,同时分别设立Huvec12对照组,血管损伤细胞组,血管损伤抑制组,Huvec12转染miR-375组。24h后收集细胞,在mRNA和蛋白水平检测Mtpn、NFκB、profilin1、sICAM1的表达,经荧光染色观察细胞F-actin的变化,再用流式细胞仪检测细胞凋亡。结果：血管损伤细胞中过表达miR-375后,在mRNA和蛋白水平靶基因Mtpn下降,NFκB的表达活性下降,使糖尿病血管病变的标志profilin1下调;F-actin表达恢复;细胞粘附因子（sICAM1）表达下降,细胞凋亡减少。结论：初步证明miR-375可以抑制AGEs介导的糖尿病血管细胞损伤的发生,可能成为糖尿病血管损伤并发症基因治疗的靶点。     

Transformation of the collateral vascular bundles into amphivasal vascular bundles in an Arabidopsis mutant.

Arabidopsis inflorescence stems develop a vascular pattern similar to that found in most dicots. The arrangement of vascular tissues within the bundle is collateral, and vascular bundles in the stele are arranged in a ring. Although auxin has been shown to be an inducer of vascular differentiation, little is known about the molecular mechanisms controlling vascular pattern formation. By screening ethyl methanesufonate-mutagenized populations of Arabidopsis, we have isolated an avb1 (amphivasal vascular bundle) mutant with a novel vascular pattern. Unlike the collateral vascular bundles seen in the wild-type stems, the vascular bundles in the avb1 stems were similar to amphivasal bundles, i.e. the xylem completely surrounded the phloem. Furthermore, branching vascular bundles in the avb1 stems abnormally penetrated into the pith, which resulted in a disruption in the ring-like arrangement of vascular bundles in the stele. The avb1 mutation did not affect leaf venation pattern and root vascular organization. Auxin polar transport assay indicated that the avb1 mutation did not disrupt the auxin polar transport activity in inflorescence stems. The avb1 mutation also exhibited pleiotropic phenotypes, including curled stems and extra cauline branches. Genetic analysis indicated that the avb1 mutation was monogenic and partially dominant. The avb1 locus was mapped to a region between markers mi69 and ASB2, which is covered by a yeast artificial chromosome clone, CIC9E2, on chromosome 5. Isolation of the avb1 mutant provides a novel means to study the evolutionary mechanisms controlling the arrangement of vascular tissues within the bundle, as well as the mechanisms controlling the arrangement of vascular bundles in the stele.     

Alterations of vascular prostacyclin and thromboxane A2 in Dahl genetical strain susceptible to salt-induced hypertension

To assess the implications of vascular eicosanoids system in the hypertension of Dahl salt-sensitive (Dahl S) strain, we investigated the production of vascular vasodepressor and vasoconstrictor eicosanoids in Dahl S rats. 14-week-old Dahl S rats on a 0.11% NaCl diet (normotension) or a 0.3% NaCl diet (borderline hypertension) had a significantly lowered generation of vascular prostacyclin (PGI2), compared with Dahl salt-resistant (Dahl R) rats. The impairment of vascular PGI2 in Dahl S rats was restored to the normal level of Dahl R rats with the elevation of blood pressure induced by a high salt diet (4% NaCl). The production of vascular PGI2 was closely related to the height of blood pressure. The deterioration of vascular PGI2 was also found in 4-week-old Dahl S rats with normotension. Conversely, vascular thromboxane A2 (TXA2) was significantly enhanced in 14-week-old Dahl S rats in all of the feeding groups. Thus, it seems possible that the proved alterations of the vasodepressor and vasoconstrictor eicosanoids partially contribute to the genesis of salt hypertension. Although the exact mechanisms remain obscure, the adaptation of vascular PGI2 on a high salt diet may be suitable to compete with the high blood pressure and to protect against the vascular damage.     

辽藁本(Ligusticum jeholense)幼苗初生维管系统的发育

应用整体透明和石蜡连续切片等方法,对辽藁本幼苗初生维管系统的发育进行了观察。结果表明：该幼苗的轴向器官中,以子叶节区下部的初生维管系统先建立,向下发育形成了下胚轴和根的维管系统;再向上通过子叶节区中、上部的分生组织性组织与第1片真叶的叶迹相连;上胚轴一苗的维管系统向下发育与子叶迹相连,至此构成了该幼苗完整、连续的初生维管系统。此外,对幼苗侧生器官子叶片的三出一叉状脉的形成进行了观察,认为该叶脉序属于原始脉序类型。     

The prevalence of obesity-related hypertension and risk for new vascular events in patients with vascular diseases

Higher body weight is associated with an increased prevalence of vascular risk factors. Obesity leads to hypertension by various mechanisms, often referred to as obesity-related hypertension. Aim of the present study was to evaluate the prevalence and the vascular risk of the combination of obesity and hypertension in patients with vascular diseases. A cohort of patients with various clinical manifest vascular diseases (n = 4,868) was screened for vascular risk factors and followed (median follow-up 4.2 years) for the occurrence of vascular events (stroke, myocardial infarction, and vascular death). The prevalence of obesity was 18% (95% confidence interval (CI) 17-19%) and the prevalence of hypertension was 83% (95% CI 82-84%). The prevalence of the combination of obesity and hypertension was 16% (95% CI 15-17%). Patients with high blood pressure (BP) combined with a high weight (highest tertile systolic BP (SBP) in the highest tertile BMI) were not at higher risk for new vascular events (hazard ratios (HR) 1.29; 95% CI 0.89-1.88) or mortality (HR 1.18; 95% CI 0.81-1.73) compared to patients without high BP and high weight (patients in the lowest tertile of SBP in the lowest tertile of BMI). Patients with only high weight did not have an elevated risk either for vascular events (HR 1.34; 95% CI 0.91-1.98) or mortality (HR 1.22; 95% CI 0.81-1.83) compared to patients without high BP and high weight. The prevalence of the combination of hypertension and obesity is low in patients with vascular diseases and does not confer a higher risk for recurrent vascular diseases and mortality than each risk factor alone.     

Responses of plant vascular systems to auxin transport inhibition.

To assess the role of auxin flows in plant vascular patterning, the development of vascular systems under conditions of inhibited auxin transport was analyzed. In Arabidopsis, nearly identical responses evoked by three auxin transport inhibitor substances revealed an enormous plasticity of the vascular pattern and suggest an involvement of auxin flows in determining the sites of vascular differentiation and in promoting vascular tissue continuity. Organs formed under conditions of reduced auxin transport contained increased numbers of vascular strands and cells within those strands were improperly aligned. In leaves, vascular tissues became progressively confined towards the leaf margin as the concentration of auxin transport inhibitor was increased, suggesting that the leaf vascular system depends on inductive signals from the margin of the leaf. Staged application of auxin transport inhibitor demonstrated that primary, secondary and tertiary veins became unresponsive to further modulations of auxin transport at successive stages of early leaf development. Correlation of these stages to anatomical features in early leaf primordia indicated that the pattern of primary and secondary strands becomes fixed at the onset of lamina expansion. Similar alterations in the leaf vascular responses of alyssum, snapdragon and tobacco plants suggest common functions of auxin flows in vascular patterning in dicots, while two types of vascular pattern alterations in Arabidopsis auxin transport mutants suggest that at least two distinct primary defects can result in impaired auxin flow. We discuss these observations with regard to the relative contributions of auxin transport, auxin sensitivity and the cellular organisation of the developing organ on the vascular pattern.     

Distribution of lipid microspheres incorporating prostaglandin E1 to vascular lesions

The intravascular distribution of 0.2 mu lipid microspheres (LM) containing prostaglandin E1 (lipo-PGE1) injected intravenously in spontaneously hypertensive rats (SHR) and arteriosclerotic rabbits was investigated by electron microscopic observation and quantification of radiolabelled compounds. LM were observed under an electron microscope to concentrate in subendothelial space of vascular walls, particularly in vascular lesions associated with hypertension or arteriosclerosis. Radiolabelled lipo-PGE1 accumulated more densely in the vascular walls than did free PGE1, and the difference was more conspicuous in vascular lesions. This indicates that lipo-PGE1 penetrates vascular endothelium and then accumulates in blood vessels to result in augmentation of the pharmacological action of prostaglandin. These findings suggest the usefulness of LM as a carrier of prostaglandin to vascular lesions.     

Time course involvement of matrix metalloproteinases in the vascular alterations of renovascular hypertension

Increased vascular matrix metalloproteinases (MMPs) levels play a role in late phases of hypertensive vascular remodeling. However, no previous study has examined the time course of MMPs in the various phases of two-kidney, one-clip hypertension (2K1C). We examined structural vascular changes, collagen and elastin content, vascular oxidative stress, and MMPs levels/activities during the development of 2K1C hypertension. Plasma angiotensin converting enzyme (ACE) activity was measured to assess renin-angiotensin system activation. Sham or 2K1C hypertensive rats were studied after 2, 4, 6, and 10weeks of hypertension. Systolic blood pressure (SBP) was monitored weekly. Morphometry of structural changes in the aortic wall was studied in hematoxylin/eosin, orcein and picrosirius red sections. Aortic NADPH activity and superoxide production was evaluated. Aortic gelatinolytic activity was determined by in situ zymography, and MMP-2, MMP-14, and tissue inhibitor of MMPs (TIMP)-2 levels were determined by gelatin zymography, immunofluorescence and immunohistochemistry. 2K1C hypertension was associated with increased ACE activity, which decreased to normal after 10 weeks. We found increased aortic collagen and elastin content in the early phase of hypertension, which were associated with vascular hypertrophy, increased vascular MMP-2 and MMP-14 (but not TIMP-2) levels, and increased gelatinolytic activity, possibly as a result of increased vascular NADPH oxidase activity and oxidative stress. These results indicate that vascular remodeling of renovascular hypertension is an early process associated with early increases in MMPs activities, enhanced matrix deposition and oxidative stress. Using antioxidants or MMPs inhibitors in the early phase of hypertension may prevent the vascular alterations of hypertension.     

Morphological analysis of neovascularization at early stages of rat splenic autografts in comparison with tumor angiogenesis

Summary This study was undertaken to reveal the neovascularization at early stages of splenic autografts three-dimensionally, to illustrate the differences between it and tumor angiogenesis, and to establish its origin. Early vascular formation after transplantation of the rat spleen or Waker tumor into the major omentum was examined by using a video macroscope, vascular casting methods and the organ culture technique. A complex vascular network layer (vascular cortex) was first formed beneath the capsule of an autograft; later, vascular buds grew from this network toward the necrotic center. They anastomosed and changed into a form resembling with-ered twigs (vascular medulla). Tumor angiogenesis did not present such morphological features and was characterized by capillary loop formation with a columnar vertex resembling an inverted V. This fundamental structure did not change throughout angiogenesis except for dilation and irregularity of vascular diameter. The organ culture technique demonstrated that the preliminary vasculature was formed in splenic autografts by regeneration of preexisting vessels in the graft and not by invading capillaries. Transmission electron microscopy showed that the cells present had characteristics of sinus endothelial cells. These results suggest that preexisting sinus endothelial cells rearrange themselves after devascularization and reconstruct a new vasculature that an-astomoses with the penetrating capillaries. This mechanism establishes vascular circulation at an early stage, and accelerates regeneration of the splenic autograft before complete necrosis.     

Metabolic pathways of the fossil dinosaur bones Part II. Vascular canal in the communication system

Examination was made on the fossil dinosaur bone 80 million years old. Samples to be examined were prepared by specially elaborated methods. The vascular canal of the dinosaur bone was the object of study. The microscopic and ultrastructural images of the canal revealed three zones therein: proper, perivascular, and vascular. The zone proper was formed by the mineralized wall of the canal, the perivascular zone was a space between the proper and the vascular zone, and the vascular zone was made up of the canal contents identified with blood vessels. The perivascular zone contained collagen fibres; moreover, histochemical examinations revealed in it mucopolysaccharides and lipids. In the wall of the vascular canal (zone proper) the outlets of the bone canaliculi departing from the osteocyte lacunae were detected. The endings of these canaliculi were of two kinds: they were either of the same diameter as the rest of the canaliculus (more numerous) or assumed a widening funnel form as the canaliculi reached the vascular canal (less numerous). By analogy with modern bone appropriate functions may be ascribed to particular zones distinguished in the vascular canal and to the varied endings of the bone canaliculi in the system of conveyance of nutrient and conservative elements as well as metabolites.     

WR2721 ameliorates the radiation-induced depression in reactivity of rat abdominal aorta to U46619

Previous studies showed that 20 Gy whole-body gamma irradiation results in a decreased response of the abdominal aorta to the stable thromboxane A2 (TXA2) mimic, U46619. The present study evaluated the effect of WR2721 on this radiation-induced decrease in vascular responsiveness. Rats receiving WR2721 (200 mg/kg, i.p.) 20 min before irradiation showed no depression in vascular reactivity to U46619 compared to control. The abolition of the radiation-induced decrease in vascular responsiveness was not caused by a direct vasoconstrictor action of WR2721 or its metabolites. The vascular response of rat abdominal aortic rings to KCl was unchanged after in vivo exposure to ionizing radiation. WR2721 did not alter the vascular response to KCl. These studies confirm that exposure to whole-body ionizing radiation decreased abdominal aortic vascular responsiveness to U46619. This depressed vascular reactivity can be abolished by pretreatment with the radioprotectant, WR2721. These observations may provide a rapid initial screening method for evaluating the in vivo efficacy of radioprotectant drugs.     

血管病变机制与血管功能调控研究的现状与趋势

本文从4个方面综述并讨论了血管病变机制与血管功能调控研究的重要意义、现状与发展趋势:(1)血管病变的机制研究是重大的社会需求,而且是国际医学领域关注的重要热点问题;(2)血管病变机制与血管功能调控研究的现状、前沿热点和关键科学问题;(3)血管稳态与重构的调控机制研究面临的困难与挑战;(4)中国在血管病变相关重大疾病研究领域的主要方向.通过对血管生物医学领域具有普遍性、前沿性的重要科学问题进行讨论,提出阐明血管稳态和重构的调控机制是研究血管病变机制的关键.研究中应注重多学科交叉,利用基因组学、生物信息学、再生医学、影像学、组织工程与材料工程等领域的新进展,建立各种新方法、新技术和新的模式生物,为研究以血管病变为病理基础的多种重大疾病的机制、及实现早期预警和防治奠定基础.