1,720,966 research outputs found
Meningioma: the impact of new techniques for the diagnosis and prognosis
No full textOur knowledge of meningioma has expanded considerably in the last few years. Immunohistochemistry, cytogenetics and molecular biology have given an important contribution to this improvement. Meningiomas can have almost endless variations in cellular morphology, architectural patterns and metaplastic changes. The majority of them have no prognostic implications. But a few variants should be recognised because of peculiar clinico-pathologic correlations or biological behavior. Histological features useful in distinguishing benign from potentially aggressive meningiomas have been identified. According to the WHO classification meningiomas are classified as benign (Grade 1), atypical (Grade 2) and anaplastic (Grade 3). Since histological appearance fails to predict accurately the clinical behaviour in a significant percentage of meningiomas, the attention has turned from tumor histology to tumor biology. Proliferative indices can be used, together with other histologic features, in assessing the prognosis as well as the postoperative management of the patients. Karyotyping may be of use to identify a subgroup of patients at higher risk for recurrence who may need special follow-up and treatment. The most consistent chromosome aberration in meningiomas seems to be a monosomy 22. As the karyotype becomes progressively abnormal, the tumor becomes more aggressive. Molecular genetic analysis has shown that TP53 gene mutation may be considered as a marker for malignant transformation in meningioma. P53 immunoreactivity is not always associated with the gene mutation but is not detectable in benign meningiomas
Microvessel quantitation in intraductal and early invasive breast carcinomas.
No full textOBJECTIVE: To study the angiogenic process in intraductal carcinoma of the breast, with and without a small focus of stromal infiltration, and to compare the microvessel density between the in situ phase and the early infiltration phases of breast cancer.
STUDY DESIGN: Microvessel density (number of microvessels per square millimeter of neoplasia) was quantitatively evaluated on anti-factor VIII-immunostained histologic sections obtained from 10 ductal carcinomas in situ (DCIS) (category A), 22 DCIS with a small focus of stromal infiltration (category B), 10 microinvasive carcinomas (category C), 12 T1a carcinomas (category D) and 20 T1b carcinomas (category E).
RESULTS: The five categories of lesion had different values for microvessel density (P = .0017). Category A had microvessel density lower than category B (P = .0005). Category B had microvessel density higher than categories C, D and E (P = .0028, .0133 and .0033, respectively).
CONCLUSION: Microvessel density seems to be a feature related to each crucial step in the early phases of neoplastic progression
Epithelial tumors of the adult kidney: evaluation of the current diagnostic and prognostic criteria.
No full textProstate tissue and serum markers.
No full textSerum prostate specific antigen (PSA) is elevated beyond the arbitrary cut-off point of 4.0 ng/ml in the majority of patients with prostate cancer (PCa). It may also be greater than 4.0 ng/ml in some benign conditions, including benign prostatic hyperplasia (BPH). Therefore, serum PSA lacks high sensitivity and specificity for PCa. This problem has been partially overcome by calculating several PSA-related indices (such as PSA density, PSA velocity, percent free PSA) and/or evaluating other serum markers (such as human glandular kallikreins and prostate specific membrane antigen). Atypical small acinar proliferation (ASAP) often represents the underdiagnosis of cancer in biopsy material; patients with cancer on the repeat biopsy usually have an elevated serum PSA. Whether the determination of serum PSA can be of help in the identification of patients with isolated prostatic intraepithelial neoplasia (PIN), i.e., long before PCa develops, is still being debated
Image processing, diagnostic information extraction and quantitative assessment in pathology.
No full textAs we enter the information age we hold strong beliefs in the benefits of digital technology applied to pathology: numerical representation offers objectivity. Digital knowledge may indeed lead to significant information discovery, and, processing systems might be designed to allow a true evolution of capabilities. Questions arise whether the methodology underlying quantitative analysis provides the information that we need and whether it is appropriate for some of the problems encountered in diagnostic and prognostic histopathology. While one certainly would not dispute the value of statistical procedures, the clinical needs call for individual patient targeted prognosis
Prostatic intraepithelial neoplasia and prostate cancer: analytical evaluation.
No full textFor urologists and pathologists one of the two main issues in prostate pathology is the identification of those prognostic factors that could predict the exact outcome of individual patients with prostate cancer (PC). Therefore, the goal is to tailor the therapeutic approach to the clinical, morphological and biological features of each patient. The other issue involves the early detection of PC, preferably in the preinvasive phase, in order to treat the patient efficaciously. For this reason, understanding the biology of preinvasive or precursors lesions has become increasingly important. Prostatic intraepithelial neoplasia is only one of these lesions, and the best known to date. The role of others, such as atypical adenomatous hyperplasia, is considered as worth exploring. Prostatic intraepithelial neoplasia (PIN) represents the putative precancerous end of the morphologic continuum of cellular proliferations within prostatic ducts and acini. Two grades of PIN are identified (low grade and high grade), and high grade PIN is considered the direct precursor of invasive carcinoma. The continuum which culminates in high grade PIN and early invasive cancer is characterised by basal cell layer disruption, basement membrane disruption, progressive loss of markers of secretory differentiation, increasing nuclear and nucleolar abnormalities, increasing proliferative potential, and increasing variation in DNA content (aneuploidy). Clinical studies suggest that PIN predates carcinoma by ten years or more, with low grade PIN first emerging in men in the third decade of life. The clinical importance of recognising PIN is based on its strong association with carcinoma; its identification in biopsy specimens of the prostate warrants further search for concurrent invasive carcinoma. The issue of precursors of prostate cancer has several facets which reflect the multiplicity of patterns and variants of PC. A big step forward in understanding some basic aspects has already been made, especially in relation to PIN. More will be available soon. A large contribution to the management of isolated PiN lesions found in prostate biopsies is expected from molecular pathology and quantitation analysis
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
- …
