基于AFM形态学观察的细胞铺展机理的假想

本研究提出了细胞铺展机理的三个可能模型：“橡皮泥”模型、“钢筋混泥土”模型和“自我膨胀”模型。应用原子力显微镜观察了处于不同铺展程度、具有不同形态的人骨髓间充质干细胞的整体和局部外部形貌，并根据观察结果，初步推断“钢筋混泥土”模型可能就是细胞铺展的机理。尽管证据还不够充分，需要进一步的研究，却为今后的研究提供了可能的模型和研究手段。细胞铺展机理的解决必将进一步促进细胞生物学和生物医学工程等学科的发展。     

Genome profiles of bilateral dysgerminomas, a unilateral gonadoblastoma, and a metastasis from a 46, XY phenotypic female

We present a case report of a 16-year-old, phenotypic female with bilateral dysgerminomas, a unilateral gonadoblastoma, and a peritoneal metastasis. The patient's constitutional karyotype was 46,XY. The chromosomal copy number, examined by the comparative genomic hybridization technique, showed 3 gains in the dysgerminoma of the right ovary, 6 gains in the dysgerminoma of the left ovary, and 2 gains and 1 loss in the gonadoblastoma of the left ovary. The metastasis showed 5 gains of which 4 were also observed in the dysgerminoma of the left ovary. The DNA ploidy classifications of the gonadoblastoma and the dysgerminoma in the right ovary were tetraploid, whereas the dysgerminoma in the left ovary and the metastasis were aneuploid. We therefore propose that the metastasis most probably developed from the dysgerminoma of the left ovary.     

胰腺实性-假乳头状肿瘤内PTEN和nestin的表达

目的 探讨胰腺实体假乳头肿瘤（SPTP）细胞可能的组织学起源。方法 复习25例SPTP的临床病理特征，常规HE和超微结构观察，免疫组化EnVision法染色检测肿瘤细胞PTEN和nestin等的表达。结果 25例SPTP中女性22例，男性3例，中位年龄22．3岁。肿瘤主要位于胰腺内，1例位于后腹膜并与胰腺相连。1例伴有肝转移。肿瘤呈囊实性，出血、坏死明显。肿瘤细胞大小形态较一致，实性和假乳头状排列，部分似“室管膜样”菊形团。核卵圆形，有核沟，核仁不明显，核分裂象少见。肿瘤细胞均有PTEN阳性表达（18／18，100％），44％（8／18）的病例有nestin的表达。超微结构观察细胞内可见酶原样分泌颗粒和神经内分泌颗粒。结论 胰腺实体假乳头肿瘤可能起源于胰腺多能干细胞。     

Classification of Breast Masses Using Selected Shape,Edge-sharpness,and Texture Features with Linear and Kernel-based Classifiers

Breast masses due to benign disease and malignant tumors related to breast cancer differ in terms of shape, edge-sharpness, and texture characteristics. In this study, we evaluate a set of 22 features including 5 shape factors, 3 edge-sharpness measures, and 14 texture features computed from 111 regions in mammograms, with 46 regions related to malignant tumors and 65 to benign masses. Feature selection is performed by a genetic algorithm based on several criteria, such as alignment of the kernel with the target function, class separability, and normalized distance. Fisher's linear discriminant analysis, the support vector machine (SVM), and our strict two-surface proximal (S2SP) classifier, as well as their corresponding kernel-based nonlinear versions, are used in the classification task with the selected features. The nonlinear classification performance of kernel Fisher's discriminant analysis, SVM, and S2SP, with the Gaussian kernel, reached 0.95 in terms of the area under the receiver operating characteristics curve. The results indicate that improvement in classification accuracy may be gained by using selected combinations of shape, edge-sharpness, and texture features.     

Primitive Cerebral Tumor with Rhabdoid Features: A Case of Phenotypic Rhabdoid Tumor of the Central Nervous System

The rhabdoid tumor (RT) was first described as an aggressive neoplasm of unknown histogenesis affecting the kidneys of infants and young children, but has since been reported in all ages and in many other primary sites, including the central nervous system. It has been shown, however, that the histologic and cytologic features of RT can be mimicked by many other tumors of known histogenesis. For this and other reasons it remains controversial whether cases of putative extrarenal RT represent the same histogenetic entity as RT of the kidney (RTK), another entity or entities, or merely a diverse collection of unrelated tumors sharing a common morphologic phenotype. The present paper describes a lethal primary cerebral tumor in a 26-month-old Hispanic boy that was composed predominantly of cells exhibiting the “classic” rhabdoid phenotype by light microscopy. lmmunocytochemical and ultrastructural studies disclosed features of primitive neuroglial differentiation not seen in RTK. The findings in this case, as well as evidence from other studies, would seem to support the notion that primary RT of the brain may in fact constitute a morphologic and clinicopathologic entity. However, hat entity likely represents a distinctive type of neuroglial neoplasm, more closely related t o other primitive brain tumors than t o RTK.     

Investigation of feline brain anatomy for the detection of cortical spreading depression with magnetic resonance imaging

Cortical spreading depression (CSD) and peri‐infarct depolarisation (PID) are related phenomena that have been associated with the human clinical syndromes of migraine (CSD), head injury and stroke (PID). Nevertheless the existence of CSD in man remains controversial, despite the detection of this phenomenon in the brains of most, if not all, other animal species investigated. This failure to unambiguously detect CSD clinically may be at least partly due to the anatomically complex, gyrencephalic structure of the human brain. This study was designed to establish conditions for the study of CSD in the brain of a gyrencephalic species using the noninvasive technique of magnetic resonance imaging (MRI). The 3‐dimensional (3D) gyrencephalic anatomy of the cat brain was examined to determine the imaging conditions necessary to detect CSD events. Orthogonal transverse, sagittal and horizontal T₁‐weighted image slices showed that the marginal and suprasylvian gyri were the most appropriate cortical structures to study CSD. This was in view of (1) their simple geometry: (2) their lengthy extent of grey matter orientated rostrocaudally in the cortex: (3) their separation by a sulcus across which CSD spread could be studied and (4) the discontinuity in the grey matter in these regions between the right and left hemispheres dorsal to the corpus callosum. The structure suggested by the T₁‐weighted images was corroborated by systematic diffusion tensor imaging to map the fractional anisotropy and diffusion trace. Thus a single horizontal image plane could visualise the neighbouring suprasylvian and marginal gyri of both cerebral hemispheres, whereas its complex shape and position ruled out the ectosylvian gyrus for CSD studies. With the horizontal imaging plane, CSD events were reproducibly detected by animating successive diffusion‐weighted MR images following local KCl stimulation of the cortical surface. In single image frames, CSD detection and characterisation required image subtraction or statistical mapping methods that, nevertheless, yielded concordant results. In repeat experiments, CSD events were qualitatively similar in appearance whether elicited by sustained or transient KCl applications. Our experimental approach thus successfully describes cat brain anatomy in vivo, and elucidates the necessary conditions for the application of MRI methods to detect CSD propagation.     

Intertubular growth in pure seminomas: associations with poor prognostic parameters

Clinical stage I seminomas are effectively treated with surgery raising concerns as to when to give adjuvant radiation therapy given the risk of secondary malignancies. A recent randomized trial found tumor size and rete testis invasion to be the strongest predictors of relapse in clinical stage I seminomas. These 2 parameters may be surrogate measures of tumor volume. Intertubular seminoma (ITS) of the testis describes the presence of neoplastic germ cells within the interstitium of the testis. These cells are detected away from the main macroscopic mass. Because ITS can infiltrate in a 3-dimensional fashion, it may also represent a measure of tumor volume not usually noted in standard pathology reporting. The goal of this study was to determine the incidence of ITS in pure seminomas and its association with other prognostic parameters. One hundred twenty consecutive pure seminomas surgically removed between 1998 and 2003 were evaluated. ITS was defined as the presence of an interstitial or intertubular growth pattern of tumor cells, which was noncontiguous with the main tumor and present at least 3 high-power fields away from the tumor mass. The average tumor size was 3.4 cm. Of the entire cohort of patients, which included pathological stages T1 through T3, 11% had invasion through the tunica albuginea, 51% had rete testis invasion, 51% had lymphovascular invasion, 93% had associated intratubular germ-cell neoplasia, and 36% had ITS. ITS was significantly associated with rete testis invasion ( P = .001). Logistic regression analysis looking at ITS, tumor size, patient age, and lymphovascular invasion revealed that only ITS was associated with rete testis invasion (RR, 4.1, P < .0001). ITS is present in a significant proportion of pure seminomas and has a significant association with rete testis invasion. The presence of ITS may therefore be an important prognostic factor, not only because it alters the calculated size of the tumor but also because it has an association with rete testis invasion.