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1.
The serum concentrations of collagen type IV,7S, collagen type IV,nc1, and aminoterminal type III procollagen peptide immunoreactive components were measured by means of specific radioimmunoassays during development of granulation tissue in rats. The results were compared with tissue deposition of basement membranes and interstitial collagens in the granulation as measured morphometrically. A parallel sequential pattern in tissue deposition of collagen types III and IV, and serum increase of collagen types III- and IV-related fragments, was observed. Serum collagen type IV was less sensitive as a marker for development of granulation tissue than the serum procollagen type III N-peptide. This was in accordance with a low collagen type IV/interstitial collagen ratio in the granulation tissue. However, a cross-sectional study showed that serum collagens types IV,7S and IV,nc1 may be useful as early quantitative indicators of granulation tissue formation. Simultaneously, measurement of collagen type IV- and procollagen type III N-peptide-related antigens in serum provides a differentiated reflection of the dynamic matrix processes in developing granulation tissue.  相似文献   

2.
In the present study, we demonstrate delayed-type hypersensitivity (DTH) to homologous type I collagen that cross-reacts with type IV collagen. Mice immunized with native or denatured type I collagens and challenged with these same antigens or native type IV collagen develop a peak DTH response on day 7. Challenge with denatured type IV collagen or collagenase-treated type IV collagen failed to elicit DTH in type I collagen-sensitized mice. Type I collagen-sensitized spleen cells adoptively transferred DTH to types IV and I collagen to normal recipients; T cell-depleted spleen cells failed to transfer immunity. Periodate-treated type IV collagen did not elicit DTH in mice sensitized to type I collagen; however, mice sensitized with type IV collagen displayed significant DTH when challenged with periodate- treated type IV collagen. Furthermore, treatment of type IV collagen with a mixed glycosidase or alpha-glucosidase before challenge eliminated the DTH response in type I collagen-sensitized mice; beta- galactosidase treatment of type IV collagen had no effect on this response. Mice sensitized with type IV collagen, however, displayed significant DTH when challenged with these glycosidase-treated antigens. Antibodies produced to types I and IV collagen by repeated immunizations were specific for the sensitizing antigen and did not react with other connective tissue antigens. These studies indicate that a CMI response to type I collagen recognizes similar antigenic determinants on the type IV collagen molecule. These cross-reacting determinants are dependent on conformation and contain carbohydrates, particularly glucose residues.  相似文献   

3.
Rat glomerular cells were cultured in vitro to evaluate their collagen phenotype. The enriched epithelial cell population that grew out from glomeruli in the initial stages of culture primarily synthesized type IV collagen. By 14 days, mesangial cell proliferation occurred with a coordinate change in collagen phenotype, after which time these cells mainly synthesized type I collagen and lesser amounts of types III, IV, and V collagens. In addition to the standard collagens, mesangial cells synthesized and accumulated in their extracellular matrix a small molecular weight collagenous protein that accounted for 16.6% of the total radioactivity incorporated into extracellular matrix proteins. This short-chain collagen, with an approximate molecular mass of 70,000 (70 kd), appears to be a unique product of mesangial cells. Collagen biosynthesis by the mesangial cells was down-regulated by dexamethasone in a time- and dose-dependent manner. Treatment with 10(-6) mol/L dexamethasone reduced synthesis of type I and type IV collagens by about 37% and 24%, respectively. Steady-state levels of the corresponding procollagen messenger RNAs were diminished in dexamethasone-treated mesangial cells. This effect of glucocorticoid was found to be specific because dexamethasone did not affect biosynthesis and secretion of noncollagenous proteins.  相似文献   

4.
BACKGROUND: Blood vessels contain different types of collagen, with types I and III being the major components of vascular collagen. Platelet adhesion under high shear stress has been suggested to depend on the binding of von Willebrand factor (VWF) to collagen. OBJECTIVE: We analyzed the collagen type specificity for the interaction with VWF and high shear stress platelet adhesion. METHODS: VWF binding to different types of immobilized collagen and effects of antibodies against glycoprotein Ib (gpIb) and integrin alpha(2)beta(1) on platelet adhesion to type I and III collagens under high shear were analyzed. RESULTS: VWF showed high-affinity, selective binding to human and bovine type III collagens, but weak or no affinity for types I, II, IV and V under static conditions. Anti-integrin alpha(2)beta(1) markedly inhibited adhesion to type I collagen, but did not affect that to type III collagen. Anti-gpIb antibody significantly inhibited adhesion to type III collagen. Adding both antibodies abrogated the adhesion to either type I or III collagen. CONCLUSIONS: Both the gpIb-VWF interaction and the integrin alpha(2)beta(1)-collagen interaction contribute to platelet adhesion to collagen under high shear stress, and integrin alpha(II)beta(1) makes a greater contribution to adhesion to type I collagen because less VWF is bound to it.  相似文献   

5.
We have recently described a new animal model of arthritis induced by intradermal injection of a distinct type of collagen found in cartilage (type II collagen). Since immunologic sensitivity to collagen could play a role in the pathogenesis of this type II collagen-induced arthritis in rats, the ability of purified types of native collagens to induce cellular and humoral responses was quantified by antigeninduced tritiated thymidine incorporation into lymphocytes by collagen and passive hemagglutination, respectively. Rats injected intradermally with native heterologous or homologous type II collagens in adjuvant developed type-specific cellular as well as humoral reactivity. Types I and III collagens were less immunogenic than was type II. The latter collagen induced brisk cellular and humoral responses that were equivalent whether complete Freund's adjuvant or incomplete Freund's adjuvant were employed. Both responses could be induced by native type II collagens modified by limited pepsin digestion, indicating that they are not attributable to determinants in the telopeptide regions of the molecule. Thus, these studies demonstrate the unique immunogenic as well as arthritogenic properties of the type II collagen molecule and indicate that both result from a helical conformation of its structurally distinct alpha-chains. Further, they suggest that type II collagen may, by humoral or cellular mechanisms, provoke or perpetuate inflammation in other arthritic diseases.  相似文献   

6.
BACKGROUND: Autofluoresence can be used to detect neoplasia in the colon. Two known fluorophores, collagen and elastin, are probably partly responsible for colonic emission spectra. Their contribution to colonic autofluorescence was investigated. METHODS: Autofluorescence spectra of normal, dysplastic, and malignant colonic tissue were studied by using excitation wavelengths from 280 nm to 350 nm. The wavelengths of peak emission and their widths at half maximum intensity were measured. Similar measurements were performed on collagen types I, III, IV, V, IX, and elastin. Colonic spectra were compared to those of collagen and elastin. Spectral differences between collagen types IV (basement membrane) I, III, V, and IX were studied. RESULTS: Four major emission peaks were noted whose wavelength of peak emission and full widths at half maximum intensity were independent of tissue histology. The emission spectra of type IV collagen differed markedly from that of nonbasement membrane collagens and elastin. CONCLUSIONS: Type IV (basement membrane) collagen is most likely responsible for the emission peak at 365 nm. The spectra of basement membrane collagen and not other types of collagen should be used in studies of epithelial tissue spectra. Elastin did not appear to be responsible for any of the four autofluorescence peaks observed in colonic tissue.  相似文献   

7.
Collagens mediate essential hemostasis by maintaining the integrity and stability of the vascular wall. Imbalanced turnover of collagens by uncontrolled formation and/or degradation may result in pathologic conditions such as fibrosis. Thickening of the vessel wall because of accumulation of collagens may lead to arterial occlusion or thrombosis. Thinning of the wall because of collagen degradation or deficiency may lead to rupture of the vessel wall or aneurysm. Preventing excessive hemorrhage or thrombosis relies on collagen‐mediated actions. Von Willebrand factor, integrins and glycoprotein VI, as well as clotting factors, can bind collagen to restore normal hemostasis after trauma. This review outlines the essential roles of collagens in mediating hemostasis, with a focus on collagens types I, III, IV, VI, XV, and XVIII.  相似文献   

8.
目的研究不同类型胶原蛋白与成纤维细胞及角质形成细胞的黏附情况,并用原子力显微镜观察其相互作用。方法分别用牛肌腱胶原、鼠尾胶原和标准Ⅳ型胶原包被培养板,接种相同数量的原代角质细胞,在不同时相用活细胞电子计数仪测定未黏附细胞的数量,观察不同类型胶原所未黏附的细胞数量的多少,并用原子力显微镜观察胶原蛋白与细胞的黏附情况。结果接种后5min,三种胶原(鼠尾胶原、牛肌腱胶原、标准Ⅳ型胶原)中未贴壁的细胞数差别较大,Ⅳ型胶原中未贴壁的细胞最少;但培养至1h,三种胶原中未贴壁的细胞数无明显差别,三者的贴壁率几乎相同;培养至第6小时三种胶原中未贴壁的细胞数仍然无明显差别,三者的贴壁率仍然基本相近。原子力显微镜可以清晰观察到胶原及胶原与细胞间黏附的微观结构。结论牛肌腱胶原和鼠尾胶原与Ⅳ型胶原对角质形成细胞的黏附作用无明显差别,原子力显微镜可以用于观察胶原及胶原与细胞间黏附的微观结构。  相似文献   

9.
10.
Serum concentration of type IV collagen peptide, the 7S domain of type IV collagen (type IV collagen 7S) and the amino terminal propeptide of type III procollagen (type III procollagen peptide) is thought to be a useful marker of progressive liver disease. In the present study, serum levels of these collagens in patients with thyroidal diseases with normal liver function were assayed. Increased levels in the hyperthyroid state and relatively decreased levels in the hypothyroid state were observed. The increased levels in hyperthyroidism was most prominent in type IV collagen peptide. The increased level became normal in the subsidence of hyperthyroidism by treatment with anti-thyroid drug. A positive correlation between serum type IV collagen peptide levels and serum thyroid hormone levels such as T4, T3, free T4 and free T3 was observed. These facts show that serum type IV collagen peptide may be influenced by not only liver disease but also serum thyroid hormone levels. Type IV collagen peptide may provide a useful biochemical marker of hyperthyroid state.  相似文献   

11.
We studied the adhesion of primitive and committed progenitors from chronic myelogenous leukemia (CML) and normal bone marrow to stroma and to several extracellular matrix components. In contrast to benign primitive progenitors from CML or normal bone marrow, Ph1-positive primitive progenitors from CML bone marrow fail to adhere to normal stromal layers and to fibronectin and its proteolytic fragments, but do adhere to collagen type IV, an extracellular matrix component of basement membranes. Similarly, multilineage colony-forming unit (CFU-MIX) progenitors from CML bone marrow do not adhere to fibronectin or its adhesion promoting fragments but adhere to collagen type IV. Unlike committed progenitors from normal bone marrow, CML single-lineage burst-forming units-erythroid and granulocyte/macrophage colony-forming units fail to adhere to fibronectin or its components but do adhere to both collagen type IV and laminin. Evaluation of adhesion receptor expression demonstrates that fibronectin receptors (alpha 4, alpha 5, and beta 1) are equally present on progenitors from normal and CML bone marrow. However, a fraction of CML progenitors express alpha 2 and alpha 6 receptors, associated with laminin and collagens, whereas these receptors are absent from normal progenitors. These observations indicate that the premature release of malignant Ph1-positive progenitors into the circulation may be caused by loss of adhesive interactions with stroma and/or fibronectin and acquisition of adhesive interactions with basement membrane components. Further study of the altered function of cell-surface adhesion receptors characteristic of the malignant clone in CML may lead to a better understanding of the mechanisms underlying both abnormal expansion and abnormal circulation of malignant progenitors in CML.  相似文献   

12.
Cutaneous neurofibromas, characteristic lesions of neurofibromatosis 1, are composed of an abundant extracellular matrix and nerve connective tissue-derived cell types: Schwann cells, perineurial cells, and fibroblasts. In this study, the extracellular matrix gene expression by these cells was examined under culture conditions that allowed them to be metabolically active and readily identifiable by morphologic and immunocytochemical criteria. Northern hybridizations demonstrated expression of genes for type I, III, IV, and VI collagens, as well as for fibronectin, laminin, and elastin. In situ hybridizations revealed that all three cell types expressed pro alpha 1 (I), pro alpha 2 (VI), and laminin B1 chain genes. However, fibroblasts did not contain [35S]cDNA-mRNA hybrids specific for type IV collagen, whereas both Schwann cells and perineurial cells expressed these genes. Perineurial cells and fibroblasts readily expressed the fibronectin gene whereas Schwann cells were essentially devoid of the corresponding mRNA. Perineurial cells also expressed the gene for laminin A chain. The results indicate that the extracellular matrix gene expression profiles of Schwann cells, perineurial cells, and fibroblasts are distinct: all three cell types are capable of expressing some of the genes for extracellular matrix components, such as type I and VI collagens, whereas Schwann cells and perineurial cells may have the primary role in synthesizing basement membrane zone components, type IV collagen and laminin. These observations potentially relate to the mechanisms of growth and development of human neurofibromas. The results attest to the applicability of the methodology utilized here to study other human tumors with mixed cell populations.  相似文献   

13.
背景天狼星红是一种强酸性阴离子染料,染色后不褪色且具特异性,是目前胶原染色的最佳染料.胶原作为细胞外基质的主要成分之一,具有许多特殊的生理功能,机体通过胶原的合成和改建使骨折修复得以完善.目的采用苦味酸天狼星红偏振光显微观察骨折愈合过程各型胶原的比例、分布的动态变化过程.设计观察对比实验.单位武汉大学人民医院骨外科,天津医院创伤骨科,北京大学医学部积水潭医院创伤骨科,解放军军事医学科学院基础医学研究所组织工程中心.材料实验于2002-03/2003-09在解放军军事医学科学院基础医学研究所组织工程中心完成.选取健康成年中国绵羊3只,雄性,体质量25~35 kg.方法全部动物麻醉消毒后在跖骨干中段截取1 cm长的骨缺损,骨折端用6孔加压钢板固定.术后1,3,6个月取骨折部位标本,乙二胺四乙酸脱钙制备切片,苦味酸天狼星红染色,偏振光显微镜观察胶原的类型和分布.主要观察指标骨折愈合不同时期骨缺损区胶原的类型及其分布.结果实验纳入3只绵羊,全部进入结果分析.①术后不同胶原纤维偏振光显微镜下的形态学表现Ⅰ型胶原纤维紧密排列,显示很强的双折光性,呈黄色、橙色和红色的粗纤维;Ⅱ型胶原纤维显示弱的双折光,呈各种不同颜色的疏松网状;Ⅲ型胶原纤维疏网状,显示弱的双折光,呈绿色的细纤维.②术后不同胶原纤维偏振光显微镜下的数量观察术后1个月,骨折处红色和黄色的Ⅰ型胶原极少见,绿色的Ⅲ型胶原纤维占大多数,胶原排列杂乱;术后3个月,骨折处红色和黄色的Ⅰ型胶原纤维明显增加,Ⅲ型胶原纤维的比例下降,胶原纤维的排列方向开始向有序的方向发展;术后6个月,粗大而鲜艳的红黄色Ⅰ型胶原成分占据了绝大部分,细小的绿色Ⅲ型胶原纤维的数量急剧减少,呈现明显的斜行螺旋性交叉的三维排列.结论苦味酸天狼星红偏振光显微观察不仅能区分骨折局部Ⅰ、Ⅲ型胶原的类型,还可以清晰显示Ⅰ、Ⅲ型胶原的形态、分布和比例关系,具有操作简便、特异性强、灵敏度高的特点.  相似文献   

14.
IMMUNOLOGIC RELATIONS AMONG VARIOUS ANIMAL COLLAGENS   总被引:2,自引:5,他引:2       下载免费PDF全文
By the use of complement fixation and in vivo immunofluorescence with cross-absorption studies it was shown that acid soluble collagens prepared from rat, mouse, guinea pig, chicken, carp, and man exhibit species specificity. Rat and mouse collagens were found to be indistinguishable and to cross-react with guinea pig collagen. Cross-reactions also occurred between the collagens of rat and man and chicken and man. Tissue specificity, or an antigen common to all of the collagens, was not demonstrated. There was complete agreement in the results of the two immunologic methods. The findings in this study support the conclusion that collagen in some form is present in the renal glomerular basement membranes.  相似文献   

15.
Human placenta specimens obtained at term were investigated for distribution of fibronectin, collagens and glycosaminoglycans. When examined by the immunofluorescence staining technique with anti-plasma fibronectin antiserum, fibronectin was shown to be present around the fetal blood vessels and in the stroma of placental villi. The distribution of type IV collagen also was examined with specific antiserum. It was found that its distribution was similar to that of fibronectin. Conventional alcian blue staining indicated that the placental villi contained only small amounts of glycosaminoglycans. These data suggest that fibronectin and type IV collagen play important roles in tissue organization of the placental villi.  相似文献   

16.
Whether parenchymal or nonparenchymal liver cells play a predominant role in the pathophysiology of hepatic fibrosis has not been firmly established in vivo. We have addressed this question by quantitating the relative abundance of specific mRNAs for collagen types I, III, and IV, and laminin in purified populations of hepatocytes, sinusoidal endothelial cells, and lipocytes from normal and fibrotic rat liver. In normal liver, type I collagen gene expression was minimal in all cell types; mRNA for types III and IV collagen were apparent in endothelial cells and lipocytes, but not in hepatocytes. Laminin mRNA was present in all cell types. Induction of fibrogenesis by either bile duct ligation or carbon tetrachloride administration was associated with a substantial increase in mRNA for types I and III collagen in nonparenchymal cells. Lipocytes from fibrotic animals exhibited a greater than 30-fold increase in type I collagen mRNA relative to normal lipocytes, and greater than 40-fold relative to hepatocytes. Type III collagen mRNA reached 5 times that in normal lipocytes and greater than 120 times that in hepatocytes. Endothelial cells exhibited an isolated increase in type I collagen mRNA, reaching five times that in normal liver. Type IV collagen and laminin gene expression were not significantly increased in nonparenchymal cells during fibrogenesis; in fact, mRNA for type IV collagen and laminin decreased by up to 50% in endothelial cells. Despite the pronounced changes that occurred in matrix gene expression in nonparenchymal cells during fibrogenesis, no change was noted in hepatocytes. We conclude that nonparenchymal liver cells, particularly lipocytes, are important effectors of hepatic fibrosis in vivo.  相似文献   

17.
Type XIX collagen is a minor collagen that localizes to basement membrane zones, together with types IV, XV, and XVIII collagens. Because several NC1 COOH-terminal domains of other chains from basement membrane collagens were reported to exhibit antitumor activity, we decided to study the effects of the NC1(XIX) collagen domain on tumor progression using an experimental in vivo model of mouse melanoma. We observed a 70% reduction in tumor volume in NC1(XIX)-treated mice compared with the corresponding controls. Histologic examination of the tumors showed a strong decrease in tumor vascularization in treated mice. In vitro, NC1(XIX) inhibited the migrating capacity of tumor cells and their capacity to invade Matrigel. It also inhibited the capacity of human microvascular endothelial cells to form pseudotubes in Matrigel. This effect was accompanied by a strong inhibition of membrane type-1 matrix metalloproteinase (matrix metalloproteinase-14) and vascular endothelial growth factor expression. Collectively, our data indicate that the NC1 domain of type XIX collagen exerts antitumor activity. This effect is mediated by a strong inhibition of the invasive capacities of tumor cells and antiangiogenic effects. NC1(XIX) should now be considered as a new member of the basement membrane collagen-derived matrikine family with antitumor and antiangiogenic activity.  相似文献   

18.
大肠正常组织和癌组织自体荧光差异病理学基础   总被引:8,自引:0,他引:8  
目的:比较胶原Ⅰ、Ⅲ、Ⅳ型在大肠正常组织和癌组织的分布差异,分析组织癌变后胶原的改变对自体荧光产生的影响。方法:采用免疫组化技术,半定量计分分析Ⅰ、Ⅲ、Ⅳ型胶原亚型在26例病人正常和腺癌组织中的分布差异。结果:正常组织的基底膜呈现很强的Ⅳ型胶原抗体阳性反应,在基底膜形成较粗的环形染色带;Ⅰ型和Ⅲ型胶原抗体反应在细胞外基质呈连续的细丝纤维样,紧贴基底膜,间质中染色较基底膜稍深。癌组织Ⅳ型胶原抗体反应在癌巢周边为阴性,或仅在残存的基底膜有片断的阳性反应;Ⅰ型和Ⅲ型胶原在癌巢周边的反应呈阴性或不连续性的阳性,但癌间质的阳性反应较正常间质内明显。癌细胞浸润深肌层后癌巢周边间质内三种胶原抗体反应均呈阴性。Ⅰ型、Ⅲ型和Ⅳ型在正常组织和癌组织中的分布存在十分显著性差异(P〈0.001),但在不同分化程度腺癌的分布上无明显差异  相似文献   

19.
肠镜检查并发肠穿孔42例报告   总被引:3,自引:0,他引:3  
随着大肠内镜 (纤维 /电子 )检查日趋普及 ,并发肠穿孔者仍时有发生 ,内镜医师应需警惕。为此 ,笔者截至 1995年调查收集全国 2 6所医院 ( 11个省市自治区 )在 382 86例次肠镜检查中并发肠穿孔 4 2例 ,发生率为 0 .11% ,其中死亡 3例。现就本组资料分析报告如下。1 一般资料4  相似文献   

20.
The increase of total collagen and its destruction were compared for whole calvaria and long bones from young growing rats prelabeled in utero with 3H-L-proline. Rats were compared from birth to 16 weeks of age. Long bones and calvaria were isolated as intact anatomical units for autoradiography or separated by collagenase into calified and uncalcified collagens. Autoradiography using 14C-L-proline demonstrated eccentric modeling of bone collagen. With growth the mass of calcified collagen (bone) increased rapidly in calvaria and long bones. A similar increase in the mass of uncalcified collagen (mainly cartilage) occured in the long bones; a very small increase occurred in the fibrous tissue of calvaria. Total and specific radioactivities of collagens at each age were compared to that present at birth. With growth remodeling an almost complete loss of pre-existing radioactive collagen occurred from uncalcified fibrous tissue of calvaria as compared to a smaller but substantial loss from the uncalcified cartilage of long bones. A marked loss of calcifed collagen occurred in long bones as compared to a smaller loss from calvarial bones. The istopic data indicate a large turnover of fibrous tissue (type I collagen) with growth remodeling as compared to a smaller turnover of bone (calcified, type I collagen) and cartilage (typc I collagen). The turnover rate of skeletal collagens depends upon whether the collagen is calcified or not, and not upon the type of collagen.  相似文献   

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