脊髓压迫性损伤神经纤维溃变和髓鞘碱性蛋白的表达变化

目的　观察脊髓压迫性损伤中白质神经纤维溃变及MBP的表达变化。 方法　采用自行设计的压迫装置制作脊髓压迫性损伤模型,运用luxol fast blue（LFB）、免疫荧光和western blot等方法来检测脊髓受压1、3、7 d后的白质纤维变化及MBP表达变化。 结果　脊髓受压后,白质髓鞘化神经纤维出现水肿,排列疏松、髓鞘缺失等退行性溃变;髓鞘化纤维数目逐渐减少。蛋白MBP表达随着压迫时间进行性下降。 结论　脊髓压迫性损伤可导致神经纤维溃变,MBP表达下调是神经纤维溃变的原因之一。     

猫视网膜S100蛋白和髓鞘碱性蛋白表达的老年性变化

目的:比较老年猫与青年猫视网膜S100与髓鞘碱性蛋白(MBP)表达的变化.方法:用免疫组织化学ABC法显示S100、MBP阳性结构.显微镜下观察S100、MBP阳性反应,并对S100阳性细胞进行计数.结果:老年猫、青年猫S100免疫反应阳性结构均见于神经节细胞层和神经纤维层的星形胶质细胞.与青年猫相比较,老年猫视网膜中S100阳性反应强于青年猫,阳性细胞显著增加.老年猫MBP免疫反应阳性结构见于外网状层和内网状层的神经纤维,青年猫阳性反应很弱.结论:猫视网膜衰老过程中S100和MBP表达增强.     

边缘系创伤反应性髓鞘碱性蛋白表达与超微结构观察

目的：探讨创伤反应性中枢神经系统（ＣＮＳ）间接受损的可能机制。方法：借助犬双后肢低、高速投射物致伤模型,观察了边缘系下丘脑、海马及颞顶区脑组织髓鞘碱性蛋白（ＭＢＰ）表达及超微结构改变。结果：伤后８ｈ低速组下丘脑ＭＢＰ－ｍＲＮＡ表达增强（Ｐ〈０．０１）;高速组下丘脑、海马ＭＢＰ含量明显增高（Ｐ〈０．０１）,ＭＢＰ－ｍＲＮＡ表达增强（Ｐ〈０．０１）;超微结构改变以高速组下丘脑、海马为著,多集中于神经元     

Myelin basic protein immunohistochemistry: a study of the early stages of myelination in the brainstem of the rat.

An immunohistochemical study of MBP distribution in the brainstem of neonate till 16 d old rats based on the peroxidase-antiperoxidase method is described. Axons already invested with immunoreactive sheaths were found in neonate rats in the ventral funiculus of the cervical spinal cord and in the medial longitudinal fascicle of the medulla oblongata. Fibres commencing with myelination showed a closely spaced array of varicosities in longitudinal sections which diminished gradually. A caudo-rostral decrease in density of myelinated fibres in the brainstem was found in the medial and dorsal longitudinal fascicles. In contrast to other pathways, myelination in the fibres of the corticospinal tract in the brainstem occurred in a strictly synchronized pattern. The same temporal pattern of myelination was also observed in the cervical corticospinal tract, except that a few myelinated fibres had been visible much earlier within the area of the tract. At the exit of cranial nerves, the transitorial zone from central to peripheral myelin was outlined by a decrease in immunostaining.     

嗅鞘细胞移植实验性自身免疫性脑脊髓炎后髓鞘碱性蛋白的表达和小胶质细胞的捕获

目的:研究嗅鞘细胞(OECs)移植实验性自身免疫性脑脊髓炎(EAE)后髓鞘碱性蛋白(Myelin basic protein,MBP)的表达及小胶质细胞捕获OECs情况。方法:用新生近交系Wistar大鼠嗅球培养出OECs,经荧光染料羧基荧光素二乙酸盐琥珀酰亚胺酯(CFSE)标记后注入同系EAE Wistar大鼠侧脑室,免疫组化检测OECs髓鞘碱性蛋白(MBP)、单核巨噬细胞诱导分子1(ED1)和CFSE共表达情况。结果:培养OECs不表达MBP,经侧脑室移植后在EAE大鼠脑内出现多量MBP+CFSE+细胞,同时在大脑广泛区域及血管周围间隙出现多量ED1+CFSE+细胞,与对照组相比差异显著。结论:OECs在EAE环境下表达MBP分子,其抗原能被脑内小胶质细胞或巨噬细胞捕获。     

Multiple sclerosis: effect of myelin basic protein on interleukin 1, interleukin 2 production and interleukin 2 receptor expression in vitro.

The production of interleukin 1 (IL-1) and interleukin 2 (IL-2) by peripheral blood mononuclear cells (PBMC) stimulated with human myelin basic protein (MBP) was assessed in vitro in multiple sclerosis (MS) patients in relapse, patients with other neurological diseases (OND) and healthy subjects. Myelin basic protein significantly increased both IL-1 and IL-2 production by PBMC from MS patients during relapse when compared to OND patients or healthy controls. The most efficient concentration of MBP for the induction of IL-1 and IL-2 was 50 micrograms/ml. The optimal IL-1 production occurred after 48 h of PBMC culture and optimal IL-2 production after 72 h of PBMC culture. Anti-Tac monoclonal antibody (MoAb) was used to study IL-2 receptor expression on the same sample of PBM used for IL-2 study in MS patients in relapse. In addition IL-2 receptor expression was studied in PBMC from chronic progressive MS patients. In both MS groups IL-2 receptor expression on PBMC stimulated with MBP appeared higher than in control groups, but these differences were not statistically significant. IL-2 receptor expression on cerebrospinal fluid lymphocytes (CSF-L) either unstimulated or MBP-stimulated was, however, significantly higher in both MS groups when compared to OND patients. These results confirm the presence of activated lymphocytes in the CSF of MS patients during active stages of disease and suggest that this activation may be related to expansion of MBP specific cells.     

Mucin gene transcripts in benign and borderline mucinous tumours of the ovary: an in situ hybridization study

Mucinous tumours of the ovary are characterized by mucin-secreting cells exhibiting a variable endocervical, intestinal, gastric or pancreatobiliary phenotype as ascertained by microscopy, electron microscopy, histochemistry or immunohistochemistry. The molecular mechanisms underlying the tumourigenesis process are not well understood. The mucin glycoproteins expressed by ovarian mucinous tumours have not been fully characterized, but mucins are known to be implicated in tumour progression in various epithelial neoplasms. The purpose of this study was to evaluate the expression of mucin genes (MUC1, MUC2, MUC3, MUC4, MUC5AC, MUC5B, MUC6) in ovarian mucinous tumour cells, to relate MUC gene expression to the histological diagnosis, and to compare the expression patterns with those observed in normal tissues. The expression of mucin genes was evaluated by in situ hybridization in 21 mucinous tumours (11 adenomas and ten borderline tumours). Heterogeneity of expression correlated with morphological heterogeneity. Intense expression of the MUC5AC gene, suggesting a gastric surface cell phenotype, was demonstrated in 18/21 tumours (86%). Goblet cells expressing the MUC2 gene and columnar cells expressing the MUC3 gene were consistent with an intestinal phenotype, which was observed in 15 tumours (71%) including nine adenomas and six borderline tumours. Major expression of MUC4 and MUC5B consistent with an endocervical phenotype was observed in seven benign (64%) and three borderline (30%) tumours. In all, the MUC profiles suggested gastrointestinal-type cells in 13 cases (62%), gastric-type cells in five cases (24%), and intestinal-type cells in two cases (one benign, one borderline) (9%); the results were inconclusive in one borderline tumour (5%). It is concluded that gastric and, to a lesser degree, intestinal differentiation are early and almost constant events in ovarian mucinous tumourigenesis.     

Developmental regulation of phosphoprotein gene expression in the caudate-putamen of rat: an in situ hybridization study.

The regional and cellular ontogeny of the mRNA encoding the dopamine- and cAMP-regulated phosphoprotein, DARPP-32, has been studied in rat striatum by quantitative in situ hybridization histochemistry. The mRNA for DARPP-32 exhibited a characteristic developmental profile. The hybridization signal was first visible on the day of birth, at which time DARPP-32 mRNA was concentrated in patches in the caudate-putamen. By the end of the first postnatal week, the majority of neurons in the caudate-putamen expressed the DARPP-32 message. Levels of mRNA per cell increased markedly during the second postnatal week, and peaked around the beginning of the third week. The adult level of DARPP-32 mRNA was lower than that observed at the apex of mRNA expression, on a per cell basis, while the proportion of neurons expressing detectable levels of message remained relatively constant. In the nucleus accumbens and olfactory tubercle, DARPP-32 mRNA development lagged somewhat behind that observed in the caudate-putamen, but was similar in other respects. A non-quantitative study employing an oligonucleotide probe complementary to the mRNA encoding another cAMP-regulated phosphoprotein, ARPP-21, revealed a similar developmental sequence to DARPP-32. The present results suggest that for DARPP-32 mRNA, genetic and, possibly, environmental factors play a role in determining the developmental patterns observed.     

The nature of cryptic epitopes within the self-antigen myelin basic protein

Mechanisms that allow potentially autoreactive T cells to escapecentral tolerance and persist in the peripheral lymphoid organsof healthy individuals are poorly defined. It has been proposedthat such cells are specific for epitopes which normally arenot well presented to the immune system or, in other words,are cryptic. We have used synthetic peptides to define potentialT cell epitopes within the N-terminal portion of myelin basicprotein (MBP). These were defined in terms of their relativeaffinity for the MHC-restriction element I-A^u and their abilityto activate T cells in mice of the H-2^u haplotype. Three epitopeswere identified, one of which corresponded to the known dominantN-terminal epitope (Ac1-9). The other two epitopes (9–20and 5–20) bound to their MHC-restriction element withrelatively high affinity but were cryptic, as defined by thepoor response to these epitopes following immunization withintact MBP. Even the longer of these two epitopes did not induceautoimmune encephalomyelitis in H-2^u mice. These results demonstratethat antigen processing can control both the induction of andeffector function of autoreactive T cells, and is thereforea principal mechanism involved in limiting the autoreactiveT cell repertoire.     

二乙基二硫化氨基甲酸盐对大鼠外侧嗅束髓鞘碱性蛋白表达的影响

目的:检测二乙基二硫化氨基甲酸盐(DDTC)干预后大鼠外侧嗅束髓鞘碱性蛋白(MBP)表达的变化.方法:成年SD大鼠分为DDTC干预组、溶媒对照组和空白对照组,实验动物分别存活3、7、14和28 d,免疫组织化学和免疫印迹检测大鼠外侧嗅束MBP的表达变化.结果:正常大鼠和溶媒对照组大鼠外侧嗅束MBP免疫组织化学显色均匀,呈点状分布特征,免疫印迹主要显示相对分子质量为21 500、18 000、17 000和14 000等阳性条带.模型组大鼠外侧嗅束MBP的免疫组织化学显色和免疫印迹条带分布末见明显变化,但其表达在3 d和7 d时逐渐下调,14 d和28 d表达逐渐上调.结论:DDTC处理后早期大鼠外侧嗅束町能出现脱髓鞘化,晚期可能出现再髓鞘化.     

Prognostic value of HER2 expression in meningiomas: an immunohistochemical and fluorescence in situ hybridization study

The aggressiveness of meningiomas is unpredictable. HER2 represents a well-known prognostic factor in various tumors such as breast carcinomas. This work was designed to study HER2 protein expression and HER2 gene amplification in meningiomas and to evaluate their prognostic value. Frozen sections of 35 meningiomas were immunostained for HER2, estrogen receptor, progesterone receptor, E-cadherin, and MIB-1. Meningiomas immunostained for HER2 were further examined for the HER2 gene amplification by dual-color fluorescence in situ hybridization using probes for centromere 17 and 17q11.2-q12. Complete clinical information was obtained in all cases. The study included 15 atypical meningiomas, 3 anaplastic meningiomas, and 17 classic meningiomas. Five atypical/anaplastic meningiomas and 5 classic meningiomas of the whole 35 (28.5%) meningiomas expressed HER2 protein. This was considered as an overexpression in comparison with negative normal meninges. Fluorescence in situ hybridization demonstrated more HER2 gene copy in 4 of these 10 HER2-positive meningiomas. At equivalent histologic grading, meningiomas with HER2 overexpression exhibited similar immunohistochemical parameters of prognostic value than their HER2-negative counterparts; however, the rate of tumor recurrence was significantly higher in meningiomas with HER2 overexpression than in HER2-negative meningiomas. Conversely, HER2 amplification was not associated with recurrence. Some meningiomas exhibit HER2 protein overexpression in part induced by gene amplification. However, only HER2 overexpression could represent an independent prognostic factor in meningiomas.     

Osteocalcin expression in primary bone tumors--in situ hybridization and immunohistochemical study.

Osteocalcin is one of the most abundant noncollagenous proteins found in adult bone. It is a highly conserved gamma-carboxyglutamic acid-containing protein that is believed to be produced exclusively by osteoblasts. In this study, intracellular and extracellular localization of osteocalcin in osteosarcoma was examined with anti-osteocalcin antibody and in situ hybridization using a synthetic oligonucleotide. Immunohistochemically, osteoblastic osteosarcomas were all positive for osteocalcin. The chondroblastic osteosarcomas were positive on the neoplastic chondrocytes. The five fibroblastic osteosarcomas out of seven were positive for osteocalcin immunostaining over the neoplastic spindle cells. Five cases of osteoblastic osteosarcomas out of seven were positive for osteocalcin in situ hybridization. Two cases of chondroblastic osteosarcomas and three cases of fibroblastic osteosarcomas were positive for in situ demonstration of osteocalcin. The malignant tumor giant cells were positive for osteocalcin immunostaining 83%. They were also positive for in situ hybridization. The benign giant cells in five giant cell tumors and five aneurysmal bone cysts were negative for osteocalcin immunostaining. The benign giant cells in three chondroblastoma and three Paget''s disease were positive for osteocalcin. In this study, the osteocalcin in situ hybridization and immunostaining has very important meaning for making differential diagnoses of, especially giant cell rich bone forming tumors.     

The exon 2b region of the spinal muscular atrophy protein, SMN, is involved in self-association and SIP1 binding

Spinal muscular atrophy (SMA) is caused by mutations in the SMN (survival of motor neurons) gene and there is a correlation between disease severity and levels of functional SMN protein. Studies of structure-function relationships in SMN protein may lead to a better understanding of SMA pathogenesis. Self-association of the spinal muscular atrophy protein, SMN, is important for its function in RNA splicing. Biomolecular interaction analysis core analysis now shows that SMN self-association occurs via SMN regions encoded by exons 2b and 6, that exon 2b encodes a binding site for SMN-interacting protein-1 and that interaction occurs between exon 2- and 4-encoded regions within the SMN monomer. The presence of two separate self-association sites suggests a novel mechanism by which linear oligomers or closed rings might be formed from SMN monomers.