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1.

Background

The purpose of this study was to introduce a novel, simple and effective technique for creating a reliable rabbit model of abdominal aortic aneurysm (AAA) via a combination of periaortic calcium chloride (CaCl2) and elastase incubation.

Methods

Forty-eight New Zealand white rabbits were divided into four groups. The AAA model was developed via a 20-minute periaortic incubation of CaCl2 (0.5 mol/L) and elastase (1 Unit/µL) in a 1.5-cm aortic segment (Group CE). A single incubation of CaCl2 (Group C) or elastase (Group E) and a sham operation group (Sham Group) were used for the controls. Diameter was measured by serial digital subtraction angiography imaging on days 5, 15 and 30. Animals were sacrificed on day 5 and day 30 for histopathological and immunohistochemical studies.

Results

All animals in Group CE developed aneurysm, with an average dilation ratio of 65.3%±8.9% on day 5, 86.5%±28.7% on day 15 and 203.6%±39.1% on day 30. No aneurysm was found in Group C, and only one aneurysm was seen on day 5 in Group E. Group CE exhibited less intima-media thickness, endothelial recovery, elastin and smooth muscle cell (SMC) content, but stronger expression of matrix metalloproteinase-2, matrix metalloproteinase-9 and RAM11 compared to the controls.

Conclusions

The novel rabbit model of AAA created by using a combination of periaortic CaCl2 and elastase incubation is simple and effective to perform and is valuable for elucidating AAA mechanisms and therapeutic interventions in experimental studies.  相似文献   

2.
目的建立兔实验性动脉粥样硬化和心肌梗死双模型,比较血管新生在动脉粥样硬化和缺血心肌中发生机制的差异。方法选择20只雄性新西兰兔,随机分为两组,A组10只为普通饮食对照组,B组10只为高脂饮食组,共喂养9周。第3周末心导管封堵冠状动脉血管致急性心肌梗死。测定不同时期血脂水平。实验终点,苏丹Ⅲ染色测定主动脉斑块阳性面积;免疫组化染色测定不同心肌区域和主动脉血管壁CD34阳性反应强度,测定不同心肌区域新生血管密度;Western blot检测hypoxia-inducible factor1α(HIF-1α)在动脉粥样硬化和缺血心肌中的表达。结果高脂组血脂水平进行性增高。高脂组主动脉斑块阳性面积高于对照组,差异有显著性。在心肌正常区、梗死区和梗死边缘区:CD34阳性反应强度和新生血管密度各组间差异有显著性,HIF-1α的表达各组间差异有显著性;均为梗死边缘区最高,梗死区次之,正常区最低。在高脂组和对照组主动脉:CD34阳性反应强度两组间差异有显著性,HIF-1α的表达两组间差异有显著性;高脂组强于对照组。结论成功建立兔实验性动脉粥样硬化和心肌梗死双模型,提示动脉粥样硬化和缺血心肌中均有血管新生的参与。  相似文献   

3.

Objective

The aim of this study was to compare the effects of hypotensive and normotensive resuscitation with a novel combination of fluids via lactate Ringer’s solution (LRS), 6% hydroxyethyl starch 130/0.4 solution (HES), and 7.5% hypertonic saline solution (HSS) at early stage of uncontrolled hemorrhagic shock (UHS) before hemostasis.

Methods

New Zealand white rabbits (n = 32) underwent UHS by transecting the splenic parenchyma, followed by blood withdrawal via the femoral artery to target mean arterial pressure (MAP) of 40–45 mmHg. Animals were distributed randomly into 4 groups (n = 8): in group Sham, sham operation was performed; in group HS, UHS was untreated; in group HS-HR, UHS was treated by hypotensive resuscitation with HSS and LRS+HES (ratio of 2∶1) to MAP of 50–55 mmHg; in group HS-NR, UHS was treated by normotensive resuscitation with HSS and LRS+HES (ratio of 2∶1) to MAP of 75–80 mmHg. Outcomes of hemodynamics, inflammatory and oxidative response, and other metabolic variables were measured and the histopathological studies of heart, lung and kidney were performed at the end of resusucitation.

Results

Hypotensive resuscitation with the novel combination of fluids for UHS rabbits decreased blood loss, maintained better stabilization of hemodynamics, and resulted in relatively higher hematocrit and platelet count, superior outcomes of blood gas, and lower plasma lactate concentration. Besides, hypotensive resuscitation attenuated the inflammatory and oxidative response significantly in UHS rabbits.

Conclusion

Hypotensive resuscitation with the novel combination of fluids via HSS and LRS+HES (ratio of 2∶1) has an effective treatment at early stage of UHS before hemostasis.  相似文献   

4.
1. Brief interruption of spinal cord blood flow resulting from transient abdominal aortic occlusion may lead to degeneration of specific spinal cord neurons and to irreversible loss of neurological function. The alteration of nitric oxide/nitric oxide synthase (NO/NOS) pool occurring after ischemic insult may play a protective or destructive role in neuronal survival of affected spinal cord segments.2. In the present study, the spatiotemporal changes of NOS following transient ischemia were evaluated by investigating neuronal NOS immunoreactivity (nNOS-IR), reduced nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd) histochemistry, and calcium-dependent NOS (cNOS) conversion of [3H] l-arginine to [3H] l-citrulline.3. The greatest levels of these enzymes and activities were detected in the dorsal horn, which appeared to be most resistant to ischemia. In that area, the first significant increase in NADPHd staining and cNOS catalytic activity was found immediately after a 15-min ischemic insult.4. Increases in the ventral horn were observed later (i.e., after a 24-h reperfusion period). While the most intense increase in nNOS-IR was detected in surviving motoneurons of animals with a shorter ischemic insult (13 min), the greatest increase of cNOS catalytic activity and NADPHd staining of the endothelial cells was found after stronger insult (15 min).5. Given that the highest levels of nNOS, NADPHd, and cNOS were found in the ischemia-resistant dorsal horn, and nNOS-IR in surviving motoneurons, it is possible that NO production may play a neuroprotective role in ischemic/reperfusion injury.  相似文献   

5.
目的:探讨瑞舒伐他汀对兔动脉粥样硬化斑块及血清妊娠相关血浆蛋白(PAPP-A)的影响.方法:新西兰家兔18只,随机分为正常对照组(Normal组,n=6)、动物粥样梗化模型组(AS组,n=6)和瑞舒伐他汀治疗组(RSV组,n=6).于治疗前、治疗后,检测血清总胆固醇(TC)、三酰甘油(TG)、血清低密度脂蛋白胆固醇(LDL-C)及高密度脂蛋白胆固醇(HDL-C)含量,酶联免疲吸附法(ELISA)检测血清PAPP-A水平.同时,用血管内超声检查(IVUS)测定病变部位的血管外弹力膜面积(EEMA)、管腔面积(LA)和斑块面积(PA),计算管腔面积狭窄百分率(LAS%).结果:治疗前,AS组和RSV组兔的血清TC、TG、LDL-C及PAPP-A的水平较Normal组高(P<0.01),HDL-C的水平较Normal组低(P<0.01);治疗后,RSV组兔的血清TC、TG、LDL-C及PAPP-A比AS组低(P<0.01).HDL-C的水平比AS组高(P<0.01),且RSV组兔的血清TC、TG、LDL-C及PAPP-A的水平较治疗前低(P<0.01),HDL-C的水平较治疗前高(P<0.01).血管内超声检查结果显示,治疗后,RSV组兔的LAS%(30.87%±5.27%)比AS组低(37.42%±6.12%)(P<0.01).结论:瑞舒伐他汀能改善对AS兔血脂,减少AS斑块形成及降低血清PAPP-A水平.  相似文献   

6.
目的:采用DNA甲基化芯片技术探讨高脂饮食对Apo E-/-小鼠动脉粥样硬化模型全基因组DNA甲基化的影响。方法:30只雄性Apo E-/-小鼠随机分为正常组与高脂组,每组15只,正常组给予正常饲料喂养,高脂组给予高脂饲料喂养。16周后,测其血脂、血清同型半胱氨酸水平(Hcy)水平、血清DNA甲基化与血清DNA甲基化转移酶(DNMTs)水平;采用DNA甲基化芯片检测两组小鼠主动脉组织全基因组甲基化情况。结果:与正常组相比,高脂组小鼠血清CHOL、TG、LDL-C均显著升高,HDL-C显著下降;血清DNA甲基化水平与血清DNA甲基化转移酶(DNMTs)水平均显著升高。甲基化芯片结果显示:与正常组相比,高脂组主动脉全基因组中共有875个基因甲基化发生改变,差异具有统计学意义(P0.05),其中高甲基化基因数目496,占总数56.69%;低甲基化基因数目379,占总数的43.31%。结论:高脂饲料可升高主动脉基因组甲基化水平,降低基因组的表达,可能是Apo E-/-小鼠容易形成动脉粥样硬化的机制之一。  相似文献   

7.
Inflammation and oxidative stress play fundamental roles in the pathogenesis of atherosclerosis. Myeloperoxidase has been extensively implicated as a key mediator of inflammatory and redox-dependent processes in atherosclerosis. However, the effect of synthetic myeloperoxidase inhibitors on atherosclerosis has been insufficiently studied. In this study, ApoE−/− mice were randomized to low- and high-dose INV-315 groups for 16 weeks on high-fat diet. INV-315 resulted in reduced plaque burden and improved endothelial function in response to acetylcholine. These effects occurred without adverse events or changes in body weight or blood pressure. INV-315 treatment resulted in a decrease in iNOS gene expression, superoxide production and nitrotyrosine content in the aorta. Circulating IL-6 and inflammatory CD11b+/Ly6Glow/7/4hi monocytes were significantly decreased in response to INV-315 treatment. Acute pretreatment with INV-315 blocked TNFα-mediated leukocyte adhesion in cremasteric venules and inhibited myeloperoxidase activity. Cholesterol efflux was significantly increased by high-dose INV-315 via ex-vivo reverse cholesterol transport assays. Our results suggest that myeloperoxidase inhibition may exert anti-atherosclerotic effects via inhibition of oxidative stress and enhancement of cholesterol efflux. These findings demonstrate a role for pharmacologic modulation of myeloperoxidase in atherosclerosis.  相似文献   

8.
目的:探讨高脂高糖饮食对自发性高血压大鼠(spontaneously hypertensive rats,SHR)腹主动脉血管舒张功能及血管间粘附分子-1 (vascular adhesion molecule-1,VCAM-1)和细胞间粘附分子-1(intercellular adhesion molecule-1,ICAM-1)mRNA表达的影响.方法:将24只6周龄雄性SHR大鼠随机分成高脂高糖饲料组(实验组,n=12)和普通饲料组(对照组,n=12).每3周测量其空腹体重,12周后处死大鼠,分别取两组动物的腹主动脉做离体血管环对乙酰胆碱(Acetylcholine,Ach)的舒张功能实验,并提取主动脉总RNA,通过实时定量RT-PCR实验检测其VCAM-1和ICAM-1 mRNA的表达.结果:从第6周开始,实验组SHR的体重较对照组明显增加(P<0.01).12周时,实验组血管环对Ach的最大舒张率较对照组明显降低(69.20± 5.25 vs.79.10± 3.84,P<0.01);实验组动脉VCAM-1 mRNA的相对表达量是对照组的1.97倍,差异有统计学意义(197.91±22.16 vs.100.33±11.44,P<0.01),而两组ICAM-1mRNA表达的比较差异无统计学意义(97.75±8.05 vs.100.25±10.83,P>0.05).结论:高脂高糖饮食能致SHR腹主动脉血管舒张功能明显降低,可能与其显著增加其主动脉VCAM-1 mRNA的表达有关.  相似文献   

9.
Folate and other methyl-donor pathway components are widely supplemented due to their ability to prevent prenatal neural tube defects. Several lines of evidence suggest that these supplements act through epigenetic mechanisms (e.g. altering DNA methylation). Primary among these are the experiments on the mouse viable yellow allele of the agouti locus (Avy). In the Avy allele, an Intracisternal A-particle retroelement has inserted into the genome adjacent to the agouti gene and is preferentially methylated. To further test these effects, we tested the same diet used in the Avy studies on wild-derived Peromyscus maniculatus, a native North American rodent. We collected tissues from neonatal offspring whose parents were fed the high-methyl donor diet as well as controls. In addition, we assayed coat-color of a natural variant (wide-band agouti = ANb) that overexpresses agouti as a phenotypic biomarker. Our data indicate that these dietary components affected agouti protein production, despite the lack of a retroelement at this locus. Surprisingly, the methyl-donor diet was associated with defects (e.g. ovarian cysts, cataracts) and increased mortality. We also assessed the effects of the diet on behavior: We scored animals in open field and social interaction tests. We observed significant increases in female repetitive behaviors. Thus these data add to a growing number of studies that suggest that these ubiquitously added nutrients may be a human health concern.  相似文献   

10.
杨林  杨楠 《生物工程学报》2000,16(3):403-407
198 8年 ,Yanagisawa和其同事在培养的猪主动脉内皮细胞上清中分离到能对离体的猪冠状动脉产生收缩作用的多肽即内皮素 (Endothelin) ,简称为ET[1] 。ET不仅具有强大的缩血管作用 ,而且是体内多种细胞的促分裂剂 ,对心血管、肾脏、呼吸、消化、神经、生殖、内分泌各系统均有作用 ;更为重要的是 ,在多种疾病中 ,它又作为一种致病因子参与疾病的发生 ,具有重要的病理生理意义。ET只有与靶细胞上特异的ET受体结合 ,启动一系列细胞内信息传递系统 ,其中主要是磷酸肌醇系统 ,调节胞内钙浓度 ,才得以发挥其效应。在人…  相似文献   

11.
Endothelin(ET)is the most potent mammalian vasoconstrictor identified to data. As a pathogenic factor,ET is involved in the genesis of many diseases. In this study, a pair of primers was designed and synthesized according to the human ETB receptor gene (hETBR)sequence. A 394bp of DNA fragment was amplified by polymerase chain reaction(PCR) and labeled with a-32p-CTP using Random Primer-Labeling method. With this probe, rabbit lung cDNA library was screened by in situ hybridization and 11 positive clones were identified. Sequencing result showed that a complete reading frame of rabbit ETB receptor(rETBR)cDNA could be produced from three positive clones of eleven. By a series of subcloning,a recombinant plasmid including the 1326 bp of rETBR coding sequences, named pBlu Script-rETBR, was constructed. The deduced amino acid sequence indicated that the rETBR is 441 residues in length, with an expected molecular mass of approximately 49.44 kD. N-terminal 18 residues is the potential signal peptide (Score=11.11)and therefore the molecular mass of mature rETBR is 47.65 kD with 423 amino acid residues. Analysis of the rETBR hydropathy profile indicates the presence of seven hydrophobic regions, putative transmembrane domains. Potential N-glycosylation sites are the 60th and the 118 th. The structure exhibits a significant sequence and topographical similarity with G protein-coupled receptors.  相似文献   

12.
A suitable small animal model may help in the screening and evaluation of new drugs, especially those from natural products, which can be administered at lower dosages, fulfilling an urgent worldwide need. In this study, we explore whether zebrafish could be a model organism for carrageenan-induced abdominal edema. The research results showed that intraperitoneal (i.p.) administration of 1.5% λ-carrageenan in a volume of 20 µL significantly increased abdominal edema in adult zebrafish. Levels of the proinflammatory proteins tumor necrosis factor-α (TNF-α) and inducible nitric oxide synthase (iNOS) were increased in carrageenan-injected adult zebrafish during the development of abdominal edema. An associated enhancement was also observed in the leukocyte marker, myeloperoxidase (MPO). To support these results, we further observed that i.p. methylprednisolone (MP; 1 µg), a positive control, significantly inhibited carrageenan-induced inflammation 24 h after carrageenan administration. Furthermore, i.p. pretreatment with either an anti-TNF-α antibody (1∶5 dilution in a volume of 20 µL) or the iNOS-selective inhibitor aminoguanidine (AG; 1 µg) inhibited carrageenan-induced abdominal edema in adult zebrafish. This new animal model is uncomplicated, easy to develop, and involves a straightforward inducement of inflammatory edema for the evaluation of small volumes of drugs or test compounds.  相似文献   

13.
To try to establish whether mechanical stress and muscular activity in earlier life influence the incidence and severity of spinal osteoporosis in old age lateral x-ray films of the lumbar vertebrae were obtained from three matched groups, each of 100 women 50 to 90 years old. Group A was of rural Bantu accustomed to carrying heavy loads on their heads. Group B was of urban Bantu, mainly in domestic service. Group C was of women of European origin.Severe osteoporosis occurred in three cases from group A, two from group B, and 14 from group C. Lesser degrees of osteoporosis could not be assessed precisely enough for inclusion in these figures. Evenly biconcave vertebral bodies, strongly suggestive of osteomalacia, were seen in 10 from group A, five from group B, and one from group C. In many Bantu subjects the fifth lumbar vertebra appeared flattened though of good radiodensity and with no marked changes in the other vertebrae. Twenty-eight of these were from group A, 16 from group B, and none from group C.About a third of each group showed severe degenerative changes in the spine; another third showed milder changes. More cases of spondylolisthesis occurred in the Bantu groups than in the white group. Severe calcification in the abdominal aorta was noted in 24 women in group C. Mild signs occurred in 35 further women from group C, in six from group B, and in only one from group A.  相似文献   

14.

Objectives

Polymorphonuclear neutrophils (PMN) in atherosclerotic plaques have been identified only recently, and their contribution to plaque development is not yet fully understood. In this study, production of elastase, interleukin (IL)-8 and vascular endothelial growth factor (VEGF) by PMN was investigated in subjects with carotid stenosis undergoing carotid endarterectomy (CEA).

Methods

The study enrolled 50 patients (Pts) and 10 healthy subjects (HS). Circulating PMN (cPMN) isolated from venous blood (in both Pts and HS) and from plaques (pPMN, in Pts) were cultured, alone or with 0.1 μM fMLP. Elastase, IL-8 and VEGF mRNA were analyzed by real-time PCR. In CEA specimens, PMN were localized by immunohistochemistry.

Results

In both Pts cPMN and pPMN, IL-8 mRNA was higher at rest but lower after fMLP (P<0.01 vs HS), and VEGF mRNA was higher both at rest and after fMLP (P<0.01 vs HS), while elastase mRNA was not significantly different. On the contrary, protein production was always higher in cPMN of HS with respect to values measured in cells of Pts. In CEA specimens, CD66b+ cells localized to areas with massive plaque formation close to neovessels. Pts with soft and mix plaques, as defined by computed tomography, did not differ in cPMN or pPMN IL-8, VEGF or elastase mRNA, or in intraplaque CD66b+ cell density. However, Pts with soft plaques had higher white blood cell count due to increased PMN.

Conclusions

In Pts with carotid plaques, both circulating and intraplaque PMN produce IL-8, VEGF and elastase, which are crucial for plaque development and progression. These findings suggest mechanistic explanations to the reported correlation between PMN count and cardiovascular mortality in carotid ATH.  相似文献   

15.

Introduction

Composite biomaterials designed for the repair of abdominal wall defects are composed of a mesh component and a laminar barrier in contact with the visceral peritoneum. This study assesses the behaviour of a new composite mesh by comparing it with two latest-generation composites currently used in clinical practice.

Methods

Defects (7x5cm) created in the anterior abdominal wall of New Zealand White rabbits were repaired using a polypropylene mesh and the composites: PhysiomeshTM; VentralightTM and a new composite mesh with a three-dimensional macroporous polyester structure and an oxidized collagen/chitosan barrier. Animals were sacrificed on days 14 and 90 postimplant. Specimens were processed to determine host tissue incorporation, gene/protein expression of neo-collagens (RT-PCR/immunofluorescence), macrophage response (RAM-11-immunolabelling) and biomechanical resistance. On postoperative days 7/14, each animal was examined laparoscopically to quantify adhesions between the visceral peritoneum and implant.

Results

The new composite mesh showed the lowest incidence of seroma in the short term. At each time point, the mesh surface covered with adhesions was greater in controls than composites. By day 14, the implants were fully infiltrated by a loose connective tissue that became denser over time. At 90 days, the peritoneal mesh surface was lined with a stable mesothelium. The new composite mesh induced more rapid tissue maturation than PhysiomeshTM, giving rise to a neoformed tissue containing more type I collagen. In VentralightTM the macrophage reaction was intense and significantly greater than the other composites at both follow-up times. Tensile strengths were similar for each biomaterial.

Conclusions

All composites showed optimal peritoneal behaviour, inducing good peritoneal regeneration and scarce postoperative adhesion formation. A greater foreign body reaction was observed for VentralightTM. All composites induced good collagen deposition accompanied by optimal tensile strength. The three-dimensional macroporous structure of the new composite mesh may promote rapid tissue regeneration within the mesh.  相似文献   

16.
利用Phenyl-Sepharose和Sephacryl S-200柱层析,从家兔阑尾B淋巴细胞中,部分纯化了一种新的钙结合蛋白(caBP)。用SDS-聚丙烯酰胺凝胶电泳(SDSPAGE)测得CaBP表观分子量为10400,而用凝胶过滤法测得分子量为21000,故称为CaBP_(21)。显然CaBP_(21)是由两个相同的亚基组成。CaBP_(21)等电点为5.4,在SDS-PAGE中的迁移不受Ca~(2+)的影响,而在非变性甘油PAGE中,有Ca~(2+)时迁移比缺Ca~(2+)时慢。CaBP_(21)对猪脑环核苷酸磷酸二酯酶(PDE)和鸡砂囊肌球蛋白轻链激酶(MLCK)活性均无影响。  相似文献   

17.
The Warburg effect and tumor hypoxia underlie a unique cancer metabolic phenotype characterized by glucose dependency and aerobic fermentation. We previously showed that two non-toxic metabolic therapies – the ketogenic diet with concurrent hyperbaric oxygen (KD+HBOT) and dietary ketone supplementation – could increase survival time in the VM-M3 mouse model of metastatic cancer. We hypothesized that combining these therapies could provide an even greater therapeutic benefit in this model. Mice receiving the combination therapy demonstrated a marked reduction in tumor growth rate and metastatic spread, and lived twice as long as control animals. To further understand the effects of these metabolic therapies, we characterized the effects of high glucose (control), low glucose (LG), ketone supplementation (βHB), hyperbaric oxygen (HBOT), or combination therapy (LG+βHB+HBOT) on VM-M3 cells. Individually and combined, these metabolic therapies significantly decreased VM-M3 cell proliferation and viability. HBOT, alone or in combination with LG and βHB, increased ROS production in VM-M3 cells. This study strongly supports further investigation into this metabolic therapy as a potential non-toxic treatment for late-stage metastatic cancers.  相似文献   

18.
19.
Low HDL-C levels are associated with atherosclerosis and non-alcoholic steatohepatitis, and increased levels may reduce the risk of these diseases. Inhibition of cholesteryl ester transfer protein (CETP) activity is considered a promising strategy for increasing HDL-C levels. Since CETP is a self-antigen with low immunogenicity, we developed a novel CETP vaccine (Fc-CETP6) to overcome the low immunogenicity of CETP and for long-term inhibition of CETP activity. The vaccine consists of a rabbit IgG Fc domain for antigen delivery to antigen-presenting cells fused to a linear array of 6 repeats of a CETP epitope to efficiently activate B cells. Rabbits were fed a high fat/cholesterol (HFC) diet to induce atherosclerosis and NASH, and immunized with Fc-CETP6 vaccine. The Fc-CETP6 vaccine successfully elicited anti-CETP antibodies and lowered plasma CETP activity. The levels of plasma HDL-C and ApoA-I were higher, and plasma ox-LDL lower, in the Fc-CETP6-immunized rabbits as compared to the unimmunized HFC diet-fed rabbits. Pathological analyses revealed less lipid accumulation and inflammation in the aorta and liver of the Fc-CETP6-immunized rabbits. These results show that the Fc-CETP6 vaccine efficiently elicited antibodies against CETP and reduced susceptibility to both atherosclerosis and steatohepatitis induced by the HFC diet. Our findings suggest that the Fc-CETP6 vaccine may improve atherosclerosis and NASH and has high potential for clinical use.  相似文献   

20.
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