The use of morphological characteristics and texture analysis in the identification of tissue composition in prostatic neoplasia

Quantitative examination of prostate histology offers clues in the diagnostic classification of lesions and in the prediction of response to treatment and prognosis. To facilitate the collection of quantitative data, the development of machine vision systems is necessary. This study explored the use of imaging for identifying tissue abnormalities in prostate histology. Medium-power histological scenes were recorded from whole-mount radical prostatectomy sections at × 40 objective magnification and assessed by a pathologist as exhibiting stroma, normal tissue (nonneoplastic epithelial component), or prostatic carcinoma (PCa). A machine vision system was developed that divided the scenes into subregions of 100 × 100 pixels and subjected each to image-processing techniques. Analysis of morphological characteristics allowed the identification of normal tissue. Analysis of image texture demonstrated that Haralick feature 4 was the most suitable for discriminating stroma from PCa. Using these morphological and texture measurements, it was possible to define a classification scheme for each subregion. The machine vision system is designed to integrate these classification rules and generate digital maps of tissue composition from the classification of subregions; 79.3% of subregions were correctly classified. Established classification rates have demonstrated the validity of the methodology on small scenes; a logical extension was to apply the methodology to whole slide images via scanning technology. The machine vision system is capable of classifying these images. The machine vision system developed in this project facilitates the exploration of morphological and texture characteristics in quantifying tissue composition. It also illustrates the potential of quantitative methods to provide highly discriminatory information in the automated identification of prostatic lesions using computer vision.

Properties of SEPT9 Isoforms and the requirement for GTP binding

Members of the evolutionarily conserved septin family of genes are emerging as key components of several cellular processes including membrane trafficking, cytokinesis, and cell-cycle control events. SEPT9 has been shown to have a complex genomic architecture, such that up to 15 different isoforms are possible by the shuffling of five alternate amino termini and three alternate carboxy termini. Genomic and transcriptional alterations of SEPT9 have been associated with neoplasia. The present study has used a Sept9-specific antibody to determine the pattern of isoform expression in a range of tumour cell lines. Western blot analysis indicated considerable variation in the relative amounts and isoform content of Sept9. Immunofluorescence studies showed a range of patterns of cytoplasmic localization ranging from mainly particulate to mainly filamentous. Expression constructs were also generated for each amino terminal isoform to investigate the patterns of localization of individual isoforms and the effects on cells of ectopic expression. The present study shows that the epsilon isoform appears filamentous in this overexpression system while the remaining isoforms are particulate and cytoplasmic. Transient transfection of individual constructs into tumour cell lines results in cell-cycle perturbation with a G2/M arrest and dramatic growth suppression, which was greatest in cell lines with the lowest amounts of endogenous Sept9. Similar phenotypic observations were made with GTP-binding mutants of all five N-terminal variants of Sept9. However, dramatic differences were observed in the kinetics of accumulation of wild-type versus mutant septin protein in transfected cells. In conclusion, the present study shows that the expression patterns of Sept9 protein are very varied in a panel of tumour cell lines and the functional studies are consistent with a model of septin function as a component of a molecular scaffold that contributes to diverse cellular functions. Alterations in the levels of Sept9 protein by overexpression of individual isoforms can clearly perturb cellular behaviour and may thus provide a mechanistic explanation for observations of deranged septin expression in neoplasia. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

SEPT9_v4 expression induces morphological change, increased motility and disturbed polarity

Several lines of evidence indicate that altered expression of SEPT9 is seen in human neoplasia. In particular there is evidence of altered expression of the SEPT9_v4 isoform. The functional consequences of this remain unclear. We have studied the expression of wild-type- and GTP-binding mutants (G144V and S148N) of the SEPT9_v4 isoform in the MCF7 cell line as a model for its deregulation in neoplasia. We find that SEPT9_v4 expression induces dramatic actin cytoskeletal reorganization with the formation of processes around the cell periphery. Expression of the SEPT9_v4 isoform and a G144V mutant cause delocalization of endogenous SEPT9 from filamentous structures but the S148N mutant does not have this effect. In addition SEPT9_v4 isoform expression enhances cell motility and is associated with perturbation of directional movement. Expression of SEPT9_v4 GTP binding mutants also has potent effects on morphology and motility and causes loss of normal polarity, as judged by Golgi reorientation assays. The phenotypes induced by expression of the SEPT9_v4 isoform and the GTP mutants provide an insight into possible mechanisms of SEPT9_v4 function and suggest that the GTPase functions have both ras- and rab-like features. We propose a model in which overexpression of the SEPT9_v4 isoform in neoplasia is associated with perturbation of SEPT9 complexes, leading to phenotypes associated with neoplasia. Copyright (c) 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

The CTLA4 + 49A/G and CT60 polymorphisms and chronic inflammatory arthropathies in Northern Ireland

Rheumatoid and juvenile idiopathic arthritis (RA, JIA) are chronic inflammatory arthropathies with an autoimmune background. The cytotoxic T-lymphocyte antigen-4 (CTLA-4) protein plays a key role in the down-regulation of T cell activation. We analyzed the CTLA4 +49A/G and CT60 polymorphisms in cohorts of Northern Irish RA and JIA patients and healthy control subjects using restriction fragment length polymorphism methods. The +49 A allele was increased in RA (61.2%; P=0.02; OR=1.28; 95% C.I.=1.04-1.58) and JIA (61.8%; P=0.14) patients compared to the control population (55.3%). No significant association was observed for the CT60 polymorphism. Haplotype analysis revealed a significantly different distribution of +49 A/G-CT60 haplotypes in RA and JIA patients compared to controls (P value

Temporal characteristics of cardiomyocyte hypertrophy in the spontaneously hypertensive rat.

Background The spontaneously hypertensive rat (SHR) is frequently used as model of cardiovascular disease, with considerable disparity in reported parameters of hypertrophy. The aim of this study was to assess the temporal changes occurring during the development and progression of cardiomyocyte hypertrophy in SHR, subsequent to pressure overload, compared to changes associated with normal aging using the normotensive Wistar–Kyoto (WKY) rat. Methods Ventricular cardiomyocytes were isolated from rats at 8, 12, 16, 20 and 24 weeks, and parameters of hypertrophy (cell dimensions, protein mass, de novo protein synthesis, and gene expression) and function (contraction and hypertrophic responsiveness in vitro) were assessed. Results Hypertension was evident at =7 weeks in SHRs. Heart:body mass ratio, cardiomyocyte protein mass and width were elevated (P

The Apperceptive Personality Test located in personality space.

The Apperceptive Personality Test is a projective test that claims to show good psychometric properties but which has not been related to the main, Eysenckian, personality traits. This study investigated the overlap between these two tests using a sample of students. Correlational and regression analyses showed a modest degree of overlap between Extraversion, Neuroticism and some of the scales from the Apperceptive Personality Test.

Altered expression of the septin gene, SEPT9, in ovarian neoplasia.

The septin family of genes has been implicated in a variety of cellular processes including cytokinesis, membrane transport and fusion, exocytosis, and apoptosis. One member of the septin family maps to chromosome 17q25.3, a region commonly deleted in sporadic ovarian and breast tumours, and has also been identified as a fusion partner of MLL in acute myeloid leukaemias. The present study demonstrates that the pattern of expression of multiple splice variants of this septin gene is altered in ovarian tumours and cell lines. In particular, expression of the zeta transcript is detectable in the majority of tumours and cell lines, but not in a range of non-malignant adult and fetal tissues. Zeta expression is accompanied by loss of the ubiquitous beta transcript. Somatic mutations of the gene were not detected in ovarian tumours, but it was demonstrated that beta expression in tumour cell lines can be reactivated by 5-azacytidine treatment, suggesting a role for methylation in the control of expression of this gene. Copyright © 2003 John Wiley & Sons, Ltd.