ABSTRACT
AIMS: Tumour angiogenesis is essential for carcinogenesis and facilitates the process of tumour development and metastasis. Vascular endothelial growth factor (VEGF) is a well characterised angiogenetic factor and is known to play a crucial role in new vessel development. To gain further insight into the effects of microvessel density and VEGF expression in colon cancer, their relation with tumour proliferation, ploidy status, and p53 expression was investigated in colon cancer. METHODS: Tissue samples of 50 archived colon cancers were analysed by immunohistochemistry for VEGF, p53, and the endothelial cell marker, von Willebrand factor (VWF), using specific antibodies. The same samples were re-cut for flow cytometric studies to obtain S phase fraction (SPF) and ploidy status. RESULTS: A positive significant correlation was found between SPF and angiogenesis. The median microvessel count in high SPF tumours was significantly higher than in low SPF ones. No association was found between VEGF expression and SPF. A positive correlation was found between ploidy status and p53 expression and microvessel count. Furthermore, a positive correlation was established between DNA ploidy, VEGF expression, and microvessel count. CONCLUSION: This study provides evidence that in colon cancer, tumour growth may be stimulated by vascular supply, and the lack of a correlation between tumour cell proliferation and VEGF expression indicates that these two parameters may be regulated by separate mechanisms. Furthermore, the positive correlation between microvessel density, VEGF expression, and ploidy status provides more evidence that genetic alterations are involved in tumour angiogenesis.
Subject(s)
Colonic Neoplasms/pathology , Neovascularization, Pathologic/pathology , Ploidies , Adult , Aged , Aged, 80 and over , Cell Proliferation , Colonic Neoplasms/blood supply , Colonic Neoplasms/genetics , DNA, Neoplasm/genetics , Female , Flow Cytometry , Humans , Male , Middle Aged , Neoplasm Proteins/metabolism , Neovascularization, Pathologic/genetics , Neovascularization, Pathologic/metabolism , S Phase , Tumor Suppressor Protein p53/metabolism , Vascular Endothelial Growth Factor A/metabolism , von Willebrand Factor/metabolismABSTRACT
A 28-year-old woman presented with abdominal pain. Ultrasonograhic examination showed a pre-sacral mass, with complex structure and well delimitated cystss with thick walls. The resected specimen was 7.5 x 6 x 4 cm in size, well circumscribed and yellow in colour, with cysstic change containing mucoid-like material. Histologically, the lesion was composed of spindle cells with high cellularity and rich vascularization with a haemangiopericytoma-like pattern. The diagnosis of solitary fibrous tumour (SFT) was made. The differential diagnosis for SFT of the pre-sacral spaace involves haemangiopericytoma, GIST, malignant mesothelioma, synovial sarcoma, leiomyomatous tumours and granulosa cell tumour. Immunohistochemical studies revealed reactivity for CD34, CD99 and Bcl-2, but no staining for desmin, inhibin, c-kit, EMA, CK, SMA, S-100 and CD31, confirming a diagnosis of SFT. Although SFT is usually associated with a favourable prognosis, close follow-up is recommended because of the limited information on its long-term behaviour.
Subject(s)
Fibroma/pathology , Retroperitoneal Neoplasms/pathology , Adult , Biomarkers, Tumor/analysis , Diagnosis, Differential , Female , Fibroma/chemistry , Fibroma/surgery , Gastrointestinal Neoplasms/diagnosis , Granulosa Cell Tumor/diagnosis , Hemangiopericytoma/diagnosis , Humans , Immunoenzyme Techniques , Leiomyoma/diagnosis , Mesothelioma/diagnosis , Retroperitoneal Neoplasms/chemistry , Retroperitoneal Neoplasms/surgery , Sacrococcygeal Region , Sarcoma, Synovial/diagnosis , Stromal Cells/pathology , Treatment OutcomeABSTRACT
In operant tasks, control rats maintain high response rates under positive contingencies, when the probability of reinforcement is greater following a response (contingent reinforcement) than during the absence of that response. However, as contingencies approach zero, response rates decrease. In this experiment, under immediate contingent reinforcement, rats with medial septal lesions reduced their response rates, just like controls, when contingencies were shifted from positive toward zero. However, the septal rats were less sensitive to this contingency shift, compared with controls, when there was a 5-s delay between lever presses and contingent reinforcements. This lesion effect appeared to be due to a failure of voluntary response memory, which impaired sensitivity to operant contingencies when there was a delay between action and outcome.
Subject(s)
Association , Conditioning, Operant/physiology , Discrimination Learning/physiology , Reinforcement, Psychology , Septum of Brain/physiology , Animals , Behavior, Animal , Brain Diseases/physiopathology , Electrolysis/methods , Male , Rats , Rats, Long-Evans , Reaction Time/physiology , Reinforcement Schedule , Septum of Brain/anatomy & histology , Septum of Brain/injuries , Statistics, NonparametricABSTRACT
A stability-indicating, reversed-phase HPLC method was developed to assay betamethasone 17-benzoate in lipophylic bases. An on-line precolumn sample clean-up system was used to protect the analytical column from contamination; it consisted of the Waters Guard-Pak Precolumn Module and the muBondapak C18 Precolumn Insert. The method is simple, specific, accurate, and precise. It is also cost effective because it extends the life of the HPLC column.
