1,721,097 research outputs found
Robbins e Cotran Atlante di Anatomia Patologica
No full textL'Atlante racchiude le conoscenze di base dei testi di Robbins in un formato essenzialmente visivo, pensato per agevolare lo studio e l'apprendimento. Le immagini macroscopiche, microscopiche e radiologiche utilizzate nell'Atlante servono a rinforzare i contenuti presentati nel volume e nelle altre opere della serie Robbins. L'approccio all'insegnamento della Medicina adottato dall'autore è un approccio integrativo che combina, all'interno dei materiali didattici, elementi attinti dalle scienze di base, da quelle cliniche e dalle scienze comportamentali, promuovendo lo sviluppo delle conoscenze a favore di chi necessita dell'assistenza sanitaria
Involvement of μ-protocadherin in colorectal carcinogenesis: a promise for clinico-pathological evaluation.
Full text linkCell-cell adhesion is a fundamental activity to allow the maintenance of epithelial integrity, and defects impairing this process promote the formation of tumors such as colorectal cancer (CRC). In this regard, a crucial role is played by adhesion molecules, named cadherins, which exert their function through the inhibition of the beta-catenin signaling proliferation pathway, constitutively activated in CRC. A number of reports, published over the last decade, have highlighted the existence of a novel cadherin family member, called μ-protocadherin, to underline the hybrid nature of its extra-cellular region, including both cadherin-like and mucin-like domains. Is has been shown that this protein plays an important role in inter-cellular adhesion processes, inhibits beta-catenin activity in normal colorectal mucosa, undergoes a down-regulated expression in CRC and is up-regulated upon treatment with chemoprevention agents against this tumor
Assessment of K-ras, Smad4 and p53 gene alterations in colorectal metastases and their role in the metastatic process
No full textTo date there is no genetic marker that gives accurate information on the prognostic impact for patients with colorectal cancer. A particular clone, not detected in the tumor, could be responsible for the metastatic process. To overcome this problem, genetic alterations were analyzed in metastatic tissues from 58 patients who developed metastases after curative surgery for colorectal cancer. K-ras, p53 and Smad4 alterations were observed in respectively 38, 60 and 27% of the metastases. These frequencies are similar to the ones reported in primary colorectal tumors. Thus, these genetic alterations cannot be used as prognostic biomarkers in patients with colorectal cancer. The metastases were stratified into 3 groups, according to the metastatic localization. K-ras mutations were detected in respectively 75, 26 and 11% of the distant, peritoneal and liver metastases. Loss of Smad4 expression was observed more frequently in the liver (62%) than in other metastases (13%). These results suggest that the genetic changes of the tumor cells indicate the location of the metastases and thus, the route of metastatic spread
Loss of Smad4 expression predicts liver metastasis in human colorectal cancer
No full textDistant metastases represent the major cause of death after curative surgery of colorectal cancer. The aim of this study was to evaluate the role of Smad4 and KRAS genetic alterations in colorectal metastases taking into account both the site (hepatic versus extrahepatic) and the time (synchronous versus metachronous) of recurrence. We examined the immunohistochemical expression of Smad4 and frequency of KRAS mutation in primary colorectal tumors and in their corresponding metastatic tissues. Loss of Smad4 expression was noted in 37% (26/71) of the primary tumors and the corresponding metastases. Absence of Smad4 protein was more frequently observed in hepatic metastases, whether they were metachronous or synchronous, than in extrahepatic metastases (p<0.005). The frequency of KRAS mutations was high in the synchronous and extrahepatic metachronous metastases (68-80%), but was significantly lower in the hepatic metachronous metastases (11%). Our results indicate that absence of Smad4 expression correlated significantly with liver metastases regardless of the time of their occurrence and represents a promising new biomarker to predict liver metastasis in colorectal cancer patients. Therefore, this group of patients could benefit from a specific and appropriate pre- and/or post-operative therapy
Pigment epithelial-derived factor: a new player in dermal elastic fibre calcification?
Full text linkPigment epithelium-derived factor (PEDF) is an endogenously produced glycoprotein expressed in several organs during developmental stages and adulthood mainly acting on cell differentiation.(1) In vitro and in vivo studies have demonstrated that PEDF has neurotrophic and antioxidant activities as well as the ability to counteract angiogenesis, tumorigenesis, atherosclerosis, thrombosis and inflammation.(1,2) In addition, PEDF has been also related to bone metabolism, increasing alkaline phosphatase (ALP) expression and promoting osteoblast differentiation.(3) This article is protected by copyright. All rights reserved
ONCOGENES AND GROWTH FACTORS IN OVARIAN EPITHELIAL TUMORS.
No full textThe present data underline the existence of over-expression of several oncogenes in common epithelial tumours. The detection of oncogene expression in ovarian tumours may be useful in predicting tumor prognosis, and in determining genetic relationships between histologically similar but clinically dissimilar tumor types
Rare prostatic carcinomas: histogenesis and morphologic pattern.
No full textMost prostate cancers (90%) are acinar adenocarcinomas originating in the peripheral or other prostatic regions. The pathological finding, clinical course and immunohistochemical studies, indicate that the small cell carcinoma of the prostate is most likely to be a neuroendocrine neoplasm
Nucleolar organizer regions in malignant melanoma and melanocytic nevi. Comparison of two counting methods.
No full textUsing a silver staining technique, we studied nucleolar organizer regions (AgNOR) in paraffin sections of junctional nevi, compound nevi, intradermal nevi, blue nevi, dysplastic nevi, Spitz nevi, lentigo maligna, malignant melanomas in nevus, superficial spreading melanomas, and nodular melanomas. Two methods of counting black dots within nuclei were employed. One method was to count the discrete black dots within the nuclei, including the tiny black dots seen within the nucleolus; the second method did not take into account the subsidary cluster of tiny black dots seen within the nucleolus, instead treating these dots as a single structure. Whichever method we used, a significant difference was found between the pooled mean AgNOR numbers for benign and malignant lesions. We found an overlap, however, between benign, in particular Spitz and dysplastic nevi, and malignant lesions when considering individual counts of AgNOR using both methods. We conclude that studying AgNOR does not seem to be a useful technique to differentiate Spitz and dysplastic nevi from malignant melanomas
Migration cholécysto-cholédocienne de végétations adénomateuses papillaires
No full textL'adénome de la vésicule biliaire peut se cancériser; il entraine exceptionnellement une obstruction du canal cystique ou du choledoque par migration de ses végétations papillaires. Notre observation en est un exemple typique
Myxoid metastases of melanoma: report of three cases and review of the literature
No full textWe report three cases of melanoma whose metastases to skin and regional lymph nodes showed myxoid foci, findings absent in their cutaneous primary tumors
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