Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017638 (glioma)
 30,880 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to identify differences in functional activity, we compared the reactivity of glioma vasculature and the native cerebral vasculature to both dilate and constrict in response to altered P(a)CO(2). Gliomas were generated by unilateral implantation of U87MGdEGFR human glioma tumor cells into the striatum of adult female athymic rats. Relative changes in total and microvascular cerebral blood volume were determined by steady state contrast agent-enhanced magnetic resonance imaging for transitions from normocarbia to hypercarbia and hypocarbia. Although hypercarbia induced a significant increase in both total and microvascular blood volume in normal brain and glioma, reactivity of glioma vasculature was significantly blunted in comparison to normal striatum; glioma total +/- CBV increased by 0.6 +/- 0.1%/mm Hg CO(2) whereas normal striatum increased by 1.5 +/- 0.2%/mm Hg CO(2), (P <.0001, group t-test). Reactivity of microvascular blood volume was also significantly blunted. In contrast, hypocarbia decreased both total and microvascular blood volumes more in glioma than in normal striatum. These results indicate that cerebral blood vessels derived by tumor-directed angiogenesis do retain reactivity to CO(2). Furthermore, reduced reactivity of tumor vessels to a single physiological perturbation, such as hypercarbia, should not be construed as a generalized reduction of functional activity of the tumor vascular bed.
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PMID:Functional response of tumor vasculature to PaCO2: determination of total and microvascular blood volume by MRI. 1451 4

Red blood cells from patients with sickle cell disease will sickle under conditions of hypoxemia and acidosis which is a similar milieu found in malignant tumors. While control of tumor angiogenesis has long been a goal of cancer therapy, selective occlusion of tumor blood supply may be achieved by transfusion of sickle cells into patients who suffer metastatic cancer. Although this potential therapy has not been previously reported in the medical literature, the concept may have been elusive to medical mainstream thinking because it requires transfusion of diseased cells. For this therapy to be effective, other environmental factors may need to be manipulated such inducing mild hypoxemia or hypercarbia (respiratory acidosis) to induce red cell sickling. Preliminary evidence supportive of this therapeutic approach to cancer treatment is provided by case evidence that sickle cell occlusion of a malignant brain tumor (glioma) produced tumor necrosis. Also sickle cells have been successfully transfused into primates. Furthermore, donor blood is crossmatched and transfused into patients suffering from sickle cell disease regularly in clinics and this procedure is associated with acceptable morbidity. Most importantly, animal models of sickle cell disease and cancer currently exist, and this theory could be tried with available technologies including ultrasound detection of vaso-occlusion. While the proposed therapy may not cure metastatic cancer, this treatment could prove useful for decreasing the size and perhaps the pain from metastatic tumor burden. Therefore, it is hypothesized that ABO Rh compatible crossmatched sickle cells transfused into patients who suffer metastatic cancer under controlled conditions of blood oxygenation and pH will selectively produce vaso-occlusive infarcts in malignant tumors and be a useful therapy. The author hopes for further investigations.
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PMID:Transfusion of sickle cells may be a therapeutic option for patients suffering metastatic disease. 2044 56