Expression of Laminin in Oral Squamous Cell Carcinomas

Background and objectives: Laminin is a significant basement membrane (BM) glycoprotein, the expression ofwhich reflects BM integrity more precisely than do other ECM proteins. The present study aimed to evaluate lamininexpression in oral squamous cell carcinomas OSCC and to determine any associations with clinico-pathologicalparameters (surgical margin status, lymph node involvement, survival and recurrence). Methods: Laminin expression wasevaluated in 31 cases of biopsy-proven OSCC by immunohistochemical staining and its association with prognosticatorsand the Brynes grading system was determined by appropriate statistical analysis. Results: We observed a significantincrease in linear staining pattern (p<0.001) at the tumour-host interface in well-differentiated OSCC cases, in contrastto poorly differentiated lesions which exhibited intense cytoplasmic expression within tumour cells. Higher cytoplasmiclaminin expression was seen in 33.3% of cases with involved surgical margins and 69.2% of cases with lymph nodemetastasis (along with weak/absent staining of laminin around the tumour-host interface – Basement membrane aroundtumour islands). Similarly, in 60% of the cases who died and in 81.8% of cases with tumour recurrence, moderatelyintense cytoplasmic laminin expression was seen within tumour cells. On comparing variables of the Brynes gradingsystem, significant cytoplasmic expression of laminin was linked with mild inflammation (p<0.0016) and increasedmitotic activity (p<0.008). Conclusion: Based on these observations, immunohistochemical expression of lamininmight be useful to evaluate histological differentiation and aggressiveness of OSCCs.     

Basal lamina molecules are concentrated in myogenic regions of the mouse limb bud

 Molecular components of basal lamina, such as laminin, stimulate the differentiation of skeletal muscle cells in culture, while interstitial matrix components such as fibronectin are inhibitory. However, the role of extracellular matrix (ECM) molecules in muscle cell differentiation in the embryo is less well understood. As a first step toward understanding the role of the ECM in embryonic myogenesis, the localization of basal lamina molecules in the mouse limb bud before and during muscle cell differentiation was determined by immunofluorescence. Laminin, collagen type IV and nidogen (entactin) were concentrated in myogenic regions of the limb bud both before and during differentiation of skeletal muscle cells. Punctate immunofluorescence for basal lamina molecules was concentrated in dorsal and ventral premuscle and muscle masses, when compared with other regions of limb mesenchyme. In contrast, immunofluorescence for fibronectin, an interstitial extracellular matrix molecule, was decreased in premuscle and muscle masses. These results suggest that basal lamina components play an important stimulatory role in early stages of skeletal muscle differentiation in the developing mouse limb bud. Accepted: 7 May 1998     

支持鸡胚前脑神经元生长的人羊膜基膜经酶消化后的成分分析

本研究采用聚丙烯酰胺凝胶电泳和细胞体外培养方法,观察酶消化后人羊膜基膜的成分,以及它能否支持鸡胚前脑神经细胞的生长。肝素酶Ⅱ消化后的人羊膜基膜,对前脑神经元生长的支持作用,比未消化的基膜增强150％。电泳分析的结果表明,肝素酶Ⅱ消化后,类胶原多肽2α_1(260kD)和2α_2(225kD)减少,类基板蛋白多肽(212kD和200kD)增多;而经肝素酶Ⅰ、胶原酶Ⅰ消化后,基板蛋白减少。本文提示,基板蛋白是人羊膜基膜中促鸡胚前脑神经细胞生长的主要成分。     

Intracellular localization of lipoplexed siRNA in vascular endothelial cells of different mouse tissues

Liposomally formulated siRNA can be used for RNAi applications in vivo. Intravenous bolus administration of lipoplexed siRNA has been shown to reduce gene expression in the vascular endothelium. Here, we applied immunofluorescence staining for different endothelial markers (PECAM-1, CD34, laminin) on paraffin sections to compare the respective expression pattern with the intracellular localization of intravenously administered, fluorescently labeled siRNA (siRNA-Cy3-lipoplex). By confocal microscopy, lipoplexed siRNA-Cy3 was detected inside vascular endothelial cells in vivo, which where identified with co-staining of endothelial markers. Consequently, the finding of intracellular siRNA uptake by vascular endothelial cells correlated with RNAi based specific protein reduction in situ as revealed by PECAM-1 specific immunofluorescence staining in lung tissue sections. Therefore, by using a cell biological approach these in situ data emphasize the functional uptake of liposomal siRNA molecules in vascular endothelial cells of different mouse tissues as indicated in our previous molecular study.     

Basement membranes in the kidney of the dromedary camel (Camelus dromedarius): An immunohistochemical and ultrastructural study

Basement membranes consist of various proteins, the major ones being laminin and collagen type IV. Primary defects in these two proteins have been extensively associated with kidney pathologies. This study aimed to establish baseline information on the immunohistochemical distribution of laminin and collagen type IV, and to corelate these with the ultrastructure of basal laminae in the uriniferous tubules of the dromedary camel. Tissue samples were taken from the kidneys of eight adult female camels, and processed for immunohistochemical and ultrastructural investigations. Strong intensity of collagen type IV was observed within the basement membranes of Bowman’s capsule. The thickness of the basal lamina of the parietal layer of Bowman's capsule varied extensively depending on the region of the renal corpuscle; the thicker areas were always associated with cuboidal epithelial cells. The glomerular basement membrane revealed strong immunostaining of laminin, whereas the mesangial matrix was strongly immunoreactive to collagen type IV. Abundant amount of laminin was found in the basement membranes of proximal convoluted tubules, thin limbs of the loop of Henle, and collecting ducts. Dense immunostainings of laminin and collagen type IV were observed in the medullary regions of uriniferous tubule, in which numerous projections extended from the basal laminae into the subjacent connective tissue. Overall, the present study revealed marked variations in the distribution of the basement membrane markers laminin and collagen type IV in the uriniferous tubules of camel kidney. The results have also shown difference in the thickness of basal laminae. This variation in thickness, however, was unlikely to be influenced by the amount of laminin and collagen type IV.     

层粘连蛋白对腺样囊性癌细胞侵袭和转移的影响

目的 研究层粘连蛋白（ＬＮ）与人涎腺腺样囊性癌转移的关系。方法 应用免疫组织化学染色,Ｂｏｙｄｅｎ小室体外移动试验和体外粘附试验,对人涎腺腺样囊性癌细胞系Ａｃｃ－２和其克隆出的肺高转移细胞株Ａｃｃ－Ｍ进行比较研究。结果 发现ＬＮ和层粘连蛋白受体（ＬＮＲ）在Ａｃｃ－Ｍ表达明显高于Ａｃｃ－２。在加入外源性ＬＮ后,Ａｃｃ－２体外移动性、粘附率均明显提高,而Ａｃｃ－Ｍ无明显变化。结论 层粘连蛋白在Ａｃｃ转     

Structure and vascularization of the cruciate ligaments of the human knee joint

The structure and vascularization of the human anterior and posterior cruciate ligament were investigated by light microscopy, transmission electron microscopy, injection techniques and by immunohistochemistry. The major part of the anterior and posterior cruciate ligament is composed of bundles of type I collagen. Type III collagen-positive fibrils separate the bundles. The major cell type is the elongated fibroblast, lying solitarily between the parallel collagen fibrils. The histologic structure of the cruciate ligaments is not homogeneous. In both ligaments there is a zone where the tissue resembles fibrocartilage. In the anterior cruciate ligament the fibrocartilaginous zone is located 5–10 mm proximal of the tibial ligament insertion in the anterior portion of the ligament. In the posterior cruciate ligament the fibrocartilage is located in the central part of the middle third. Within those zones the cells are arranged in columns and the cell shape is round to ovoid. Transmission electron microscopy reveals typical features of chondrocytes. The chondrocytes are surrounded by a felt-like pericellular matrix, a high content of cellular organelles and short processes on the cell surface. The pericellular collagen is positive for type II collagen. The major blood supply of the cruciate ligaments arises from the middle geniculate artery. The distal part of both cruciate ligaments is vascularized by branches of the lateral and medial inferior geniculate artery. Both ligaments are surrounded by a synovial fold where the terminal branches of the middle and inferior arteries form a periligamentous network. From the synovial sheath blood vessels penetrate the ligament in a horizontal direction and anastomose with a longitudinally orientated intraligamentous vascular network. The density of blood vessels within the ligaments is not homogeneous. In the anterior cruciate ligament an avascular zone is located within the fibrocartilage of the anterior part where the ligament faces the anterior rim of the intercondylar fossa. The fibrocartilaginous zone of the middle third of the posterior cruciate ligament is also avascular. According to Pauwel’s theory of the ”causal histogenesis” (1960) the stimulus for the development of fibrocartilage within dense connective tissue is shearing and compressive stress. In the anterior cruciate ligament this biomechanical situation may occur when the ligament impinges on the anterior rim of the intercondylar fossa when the knee is fully extended. Compressive and shearing stress in the center of the middle third of the posterior cruciate ligament may result from twisting of the fiber bundles. Accepted: 12 March 1999     

Blood and lymph supply of the posterior cruciate ligament: a cadaver study

Injection techniques, immunohistochemical (antibodies against laminin), and histochemical (5′-nucleotidase activity) methods were employed to describe the vascular pattern of the human posterior cruciate ligament (PCL); in parallel we used conventional light microscopy and immunohistochemical techniques to visualize the histological structure of the PCL. The blood supply of the PCL mainly arises from the middle geniculate artery. The ligament is covered by a synovial fold where the terminal branches of the middle geniculate artery form a periligamentous network. From the synovial sheath, the blood vessels penetrate the ligament in a horizontal direction and anastomose with a longitudinally orientated intraligamentous network. Within the ligament the blood vessels are located in the loose connective tissue that is sited between longitudinal fibre bundles. Histologically the longitudinal fibre bundles of the ligament consist of dense connective tissue. Lymphatics accompany most of the smaller blood vessels, showing similar regional distribution. Compared to the surrounding synovial layer, the amount of vessels in the substance of the ligament is lower. The distribution of blood vessels within the PCL is not homogenous: we detected three avascular areas within the ligament. Both fibrocartilaginous entheses of the PCL are devoid of blood vessels, and a third avascular zone is located in the central part of the middle third. The histological structure of this zone varies from the rest of the PCL which consists of the characteristic dense connective tissue. In the central part of the PCL the tissue resembles fibrocartilage: the cell shape is round, the pericellular matrix of those cells is rich in acid glycosaminoglycans and the immunohistochemical demonstration of type II collagen is positive. The occurrence of an avascular zone within the central part of the middle third of the PCL where the tissue consists of fibrocartilage has not been described in the literature. Received: 10 March 1998 Accepted: 8 July 1998     

应用Laminin促进周围神经再生的研究

目的探讨局部应用Laminin（LN）对周围神经再生的影响。方法将34只SD大鼠分为4组,1～3组每组10只,手术切除双侧10mm坐骨神经并用硅胶管套接,左侧套管内注入LN0．6μg,右侧注入生理盐水作对照。术后1、3、4个月分别进行电生理和组织学检查。另4只鼠于术后3个月行辣根过氧化物酶逆行示踪检查。结果LN治疗组术后1、3、4个月时的神经肌肉动作电位、运动神经传导速度、再生有髓神经纤维数量及髓鞘厚度均明显优于对照组。相应节段脊髓前角和背根神经节标记神经元明显多于对照组。结论LN可促进周围神经损伤后的再生。     

血清HA、PLD、PCⅢ、LN、Ⅳ—C联合检测对慢性肝病的诊断价值探讨

目的:寻找肝纤维化等慢性肝病敏感可靠的血清学诊断指标。方法:对196例各型肝病联合检测血清透明质酸(HA)、脯氨酸肽酶(PLD)、Ⅲ型前胶原(PCⅢ)、层粘蛋白(LN)、Ⅳ型胶原(Ⅳ-C),并与10例肝组织学和30例健康献血员做对照研究。结果:五项指标分别在急性肝炎、慢性肝炎和肝硬变中依次升高,差异显著(P<0.05或P<0.01),其改变情况与轻、中、重型纤维化程度呈同步性,有良好的正相关。结论:五项指标联合检测可极大地增加慢性肝病临床诊断的准确性与可靠性,动态观察其变化可掌握病情演变。