Neoplastic blood vessels

Fibronectin. Fibronectin is expressed in and around neoplastic blood vessels during tumor growth and angiogenesis. Fibronectin is an extracellular adhesion glycoprotein that binds to integrin receptors and mediates interactions between cells and extracellular matrix components. Antibodies against fibronectin have been studied for targeting. " ... 

TothB. 1973a. 1,1-Dimethylhydrazine (unsymmetrical) carcinogenesis in mice. Light microscopic and ultrastructural studies on neoplastic blood vessels. J Natl Cancer Inst 50 181-194. 

Blood vessels penetrating tumors provide malignant cells with another point at which to enter the circulation. Evidence exists that in situation where cancers disseminate predominantly by the blood, the extent of metastasis depends upon the vasculature of the primary tumor. Thin-walled capillaries, especially those newly formed, provide poor resistance to invading cancer cells. Also, data from microscopy studies show that the endothelium of tumor vessels, particularly in areas of poor oxygenation, is often abnormal (Kl). These abnormalities may permit invasion by neoplastic cells (P3). Finally, tumors can spread by direct extension into body cavities such as pleural and peritoneal spaces. An example of this is the formation of peritoneal metastases from ovarian carcinoma. 

In addition, very recent work indicates that COX-2 may play a vital role in the regulation of angiogenesis associated with neoplastic tumor cells, hence COX-2 inhibitors may block the growth of blood vessels into developing tumors (56). Thus, according to epidemiological, clinical, and experimental data, COX-2 appears to be intimately related to the development and growth of some types of cancer, especially of colorectal cancer. 

Folkman, J. (1986). How is blood vessel growth regulated in normal and neoplastic tissue Cancer Res. 46, 467-473. 

In animals, HCl is a severe irritant of the eyes and respiratory system. The 30 min LC50 values in rats and mice are 4701 and 2644 ppm, respectively. Animals exposed to high concentrations of HCl gas developed necrosis of the tracheal and bronchial epithelium, pulmonary edema, atelectasis, emphysema, and damage to the pulmonary blood vessels and liver. Chronic exposure to 10 ppm for 6hday for life did not cause neoplastic lesions or serious irritant effects in the nasal epithelium of rats. In experimental animals, exposure to a concentration of 1350 ppm hydrogen chloride gas caused clouding of the cornea after 1.5 h and exposure to 3000 ppm for 6 h caused slight erosion of the corneal epithelium. 

Some epithelial mesotheliomas are composed of small cysts formed by uniform cuboidal mesothelial cells and associated numerous blood vessels (Fig. 12.68). This type of mesothelioma may be difficult to differentiate from a vascular neoplasm. The epithelial mesothelial cells may contain intracytoplasmic hemosiderin (Fig. 12.69). The immunophenotype of such neoplasms is identical to that of other epithelial mesotheliomas. The vascular proliferation may be related to an endothelial growth factor produced by neoplastic mesothelial cells.Adenomatoid tumors are localized benign mesothelial proliferations that most frequently occur in the epididymus and cornua of the uterus.Adenomatoid tumors have been identified in the adrenal gland and pancreas. These tumors are formed by uniform small cuboidal cells and can appear invasive. They express keratin and other markers of mesothelial cells and have the characteristic ultrastruc-tural features of mesothelial cells. Adenomatoid tumors have also been reported in the pleura. Hyperplastic... 

INTRAVASCULAR LYMPHOMA The CNS is One of the sites of predilection for intravascular lymphoma, a large B-cell lymphoma. The neoplastic cells fill the blood vessel lumina. The clinical presentation mimics vasculitis. Neoplastic cells are positive for CD20. 

Ausprunk DH, Knighton DR, Folkman J. Vascularization of normal and neoplastic tissues grafted to the chick chorioallantois. Role of host and preexisting graft blood vessels. Am J Pathol 1975 79 597-628. 

Neurofibromatosis type I (NFl) patients have a wide spectrum of clinical presentations, including developmental, pigment or neoplastic aberrations of the skin, nervous system, bones, endocrine organs, blood vessels and eyes. The cardinal features of NFl are cafe an lait macules, axillary and groin fieckhng, combined with multiple peripheral and central nerve tumors [1,2],... 

Fig. 5.1 Phases of cancer progression. When normal cells or tissues are subjected to genotoxic, cytotoxic, or carcinogenic insult, they may undergo transformation in a nitric-oxide-dependent manner. This process is characterized by activation of signaling cascades that result in increased proliferation and inhibition of apoptosis, causing neoplastic evolution in the process, which is accompanied by various biophysical and biochemical changes. Once the tumor is established, the release of angiogenic mediators is stimulated, leading to increased blood vessel formation, accompanied with increased vascularization of the tumor. Finally, in the metastatic phase, the tumors develop migratory and invasive properties that facihtate dissemination of the tumor and metastasis to secondary sites...

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