Changes in glial fibrillary acidic protein mRNA expression after corticospinal axotomy in the adult hamster

We examined changes in the expression of glial fibrillary acidic protein (GFAP) mRNA during Wallerian degeneration in the corticospinal system of the adult Golden hamster following axotomy. GFAP is the product of a type III intermediate filament (IF) gene that is expressed specifically in mature astrocytes. A well-studied component of a complex response termed reactive astrogliosis that occurs after various types of CNS injury is the increased production of astrocytic processes filled with GFAP-containing IFs. While increased expression of GFAP during reactive astrogliosis has been well established at the protein level, little is known about whether or not changes in GFAP mRNA levels occur after CNS injury. In the present study we used in situ hybridization methods to examine this issue. A 35S-labeled mouse GFAP cDNA probe was used for in situ hybridizations of sections of the brain stem obtained 2, 7, and 14 days after unilateral transections of the corticospinal tract in the caudal medulla. Film as well as emulsion autoradiography showed a dramatic increase in GFAP mRNA labeling associated with the degenerating corticospinal tract. GFAP mRNA levels were already dramatically increased in the injured corticospinal tract by 2 days post axotomy and remained elevated at 14 days. Interestingly, in addition to the robust increase in GFAP mRNA levels specifically associated with the degenerating tract, a diffuse increase in GFAP mRNA labeling was observed throughout the grey matter of the brain stem at 2 days post-axotomy, but not after this time. Immunoblotting and immunocytochemical experiments verified that the increased GFAP mRNA levels in the degenerating corticospinal system were accompanied by an increased expression of the protein. These results demonstrate that an increase in GFAP mRNA levels occurs during Wallerian degeneration in the CNS and suggest that increased expression of the GFAP gene is a major contributor to CNS scarring that results after direct traumatic injury.     

Presence of beta human papillomaviruses in nonmelanoma skin cancer from organ transplant recipients and immunocompetent patients in the West of Scotland

Background  Nonmelanoma skin cancer (NMSC) has been linked to cutaneous human papillomaviruses of the genus beta (betaPV).
Objectives  We sought to assess the presence of betaPV in NMSC biopsies from a group of Scottish skin cancer patients, both immunocompetent (IC) patients and immunosuppressed (IS) organ transplant recipients.
Methods  One hundred and twenty-one paraffin-embedded skin tumours (27 actinic keratosis, 41 intraepidermal carcinoma, 53 squamous cell carcinoma) and 11 normal skin samples were analysed for the presence of betaPV by a polymerase chain reaction–reverse hybridization assay designed to detect the presence of the 25 known betaPV genotypes.
Results  In IC patients, betaPV was detected in 30 of 59 (51%) tumours and two of 11 (18%) normal skin samples ( P  =   0·046). In IS patients, betaPV was found in 27 of 62 (44%) tumours; no normal skin samples were available for comparison. The most frequently found genotypes were HPV-24, HPV-15 and HPV-38. Of those tumours infected with betaPV, 28 of 57 (49%) were infected with more than one genotype (range 2–8). Tumours from IS patients were from a younger age group (mean age 57·4 years) than IC patients (mean age 73·8 years). Multiple infections were more common in tumours from IC patients (21 of 30; 70%) compared with those from IS patients (seven of 27; 26%) ( P  <   0·001). In the IC group, age did not appear to influence the distribution of single and multiple infections whereas in IS patients the proportion of multiple infections to single infections increased with age. There were no multiple infections in normal skin.
Conclusions  A wide spectrum of betaPV types was detected in our samples. Further characterization of betaPV in vivo is needed in order to determine the mechanisms by which the virus contributes to cutaneous carcinogenesis.     

Detergent fractionation with subsequent subtractive suppression hybridization as a tool for identifying genes coding for plasma membrane proteins

Abstract:  The identification of tumor-specific proteins located at the plasma membrane is hampered by numerous methodological pitfalls many of which are associated with the post-translational modification of such proteins. Here, we present a new combination of detergent fractionation of cells and of subtractive suppression hybridization (SSH) to gain overexpressed genes coding for membrane-associated or secreted proteins. Fractionation of subcellular components by digitonin allowed sequestering mRNA of the rough Endoplasmatic reticulum and thereby increasing the percentage of sequences coding for membrane-bound proteins. Fractionated mRNAs from the cutaneous T-cell lymphoma (CTCL) cell line HuT78 and from normal peripheral blood monocytes were used for SSH leading to the enrichment of sequences overexpressed in the tumor cells. We identified some 21 overexpressed genes, among them are GPR137B, FAM62A, NOMO1, HSP90, SLIT1, IBP2, CLIF, IRAK and ARC. mRNA expression was tested for selected genes in CTCL cell lines, skin specimens and peripheral blood samples from CTCL patients and healthy donors. Several of the detected sequences are clearly related to cancer, but have not yet been associated with CTCL. qPCR confirmed an enrichment of these mRNAs in the rough endoplasmic reticulum fraction. RT-PCR confirmed the expression of these genes in skin specimens and peripheral blood of CTCL patients. Western blotting verified protein expression of HSP90 and IBP2 in HuT78. GPR137B could be detected by immunohistology in HuT78 and in keratinocytes of dysplastic epidermis, but also in sweat glands of healthy skin. In summary, we developed a new technique, which allows identifying overexpressed genes coding preferentially for membrane-associated proteins.     

Comparing histological data from different brains: Sources of error and strategies for minimizing them

The recent development of brain atlases with computer graphics templates, and of huge databases of neurohistochemical data on the internet, has forced a systematic re-examination of errors associated with comparing histological features between adjacent sections of the same brain, between brains treated in the same way, and between brains from groups treated in different ways. The long-term goal is to compare as accurately as possible a broad array of data from experimental brains within the framework of reference atlases. Main sources of error, each of which ideally should be measured and minimized, include intrinsic biological variation, linear and nonlinear distortion of histological sections, plane of section differences between each brain, section alignment problems, and sampling errors. These variables are discussed, along with approaches to error estimation and minimization in terms of a specific example—the distribution of neuroendocrine neurons in the rat paraventricular nucleus. Based on the strategy developed here, the main conclusion is that the best long-term solution is a high-resolution 3D computer graphics model of the brain that can be sliced in any plane and used as the framework for quantitative neuroanatomy, databases, knowledge management systems, and structure–function modeling. However, any approach to the automatic annotation of neuroanatomical data—relating its spatial distribution to a reference atlas—should deal systematically with these sources of error, which reduce localization reliability.     

人胎冠状动脉原位杂交c-myc和jun原癌基因表达

目的研究原癌基因c-myc和jun在人胎冠状动脉发育过程中的表达与平滑肌细胞增殖的关系.方法用原位杂交方法检测,胎龄分别为16周、22周(因治疗需要引产)的胎儿和意外死亡的足月胎儿冠状动脉前降支c-myc mRNA和jun mRNA的表达水平.杂交反应产物用图像分析仪(MIAS300)作定量分析.结果C-myc mRNA原位杂交反应产物与被测血管区域面积的百分比在16周、22周和足月胎儿分别是70、56和10;Jun mRNA的杂交信反应产物与被测血管区域面积的百分比在这三个时期分别是68、53和8.两个原癌基因在不同阶段的表达均具有显著性差异.结论本实验首次报道c-myc和jun在人胎冠状动脉发育过程中平滑肌的表达图型,c-myc和jun在胎儿冠状动脉平滑肌细胞增殖和内膜的形成过程中可能具有重要的调控作用.     

Comparative genomic hybridization (CGH) of augmentation cystoplasties

OBJECTIVE: Tumors arising within augmentation cystoplasties are aggressive, have poor prognosis and the majority are not detected at follow-up cystoscopy. Genetic changes in tumors precede morphological abnormalities. Therefore, the aim of this study was to investigate whether genetic abnormalities detected by comparative genomic hybridization (CGH) could be used to identify those patients with augmentation cystoplasties at increased risk of tumorigenesis. METHODS: Bladder biopsy samples were obtained from 16 augmentation cystoplasty patients both distant from and near to the enterovesical anastomosis. CGH was used to detect genetic abnormalities in DNA extracted from the biopsies, archival specimens of two augmentation cystoplasties and two de novo bladder adenocarcinomas. RESULTS: A greater number of amplifications on 2p, 3q, 8q, 9p, 17p, 18pq and 20pq, were observed in bladder biopsies obtained near to the enterovesical anastomosis compared to those taken distant to the suture line. CGH of archival augmentation cystoplasty tumor DNA indicated abnormalities at several loci with amplifications at 2q, 5q, 10p and 21pq, while deletions occurred at 5p and 16p. CONCLUSIONS: The results of this study suggest that the urothelium adjacent to the bladder and/or bowel anastomosis in augmentation cystoplasties is genetically unstable. Furthermore, longitudinal studies are required to establish whether or not patients exhibiting genetic instability following augmentation cystoplasty are at greater risk of developing tumors than those with genetically stable epithelia.     

胎盘型谷胱甘肽S转移酶mRNA在大鼠肝癌癌前病变组织中的原位表达

应用原位杂交技术，观察了二乙基亚硝胺（ＤＥＮ）诱发大鼠肝癌前病变组织中胎盘型谷胱甘肽Ｓ转移酶（ＧＳＴ－Ｐ）ｍＲＮＡ的表达。结果显示，ＧＳＴ－ＰｍＲＮＡ主要在癌前病变肝组织中的变异灶及灶外卵圆形细胞内表达，且在变异灶间或和同一灶内阳性细胞间表达程度不尽一致，而正常肝、再生肝组织中未见其表达。提示在分子水平上变异灶细胞及卵圆型细胞可能成为实验性肝癌的癌前期细胞