Search results for "Tumor Hypoxia"
showing 6 items of 56 documents
Current Status of Knowledge and Critical Issues in Tumor Oxygenation
1998
In 1972 we started the systematic investigation of oxygenation status in (a) experimental tumor systems in rats and mice [e.g., 1–6], (b) in human tumors xenotransplanted into immune-deficient rnu/rnu-rats [e.g., 7–9], (c) in tumors derived from spontaneously tumorigenic or ras-transformed cell lines [10], and (d) in human tumors in situ [e.g., 11–15] under various pathophysiological conditions using polarographic O2 needle electrodes. In the earlier studies a cryospectrophotometric ex vivomicrotechnique was also used that allowed the measurement of HbO2 saturation in individual red blood cells in tumor microvessels [e.g., 16, 17]. Besides polarographic and cryospectrophotometric microtechn…
Tumor Vascularity, Hypoxia, and Malignant Progression in Solid Neoplasms
1998
Malignant progression designates the biologic process which transforms a phenotypically normal cell fixed and cooperating within a tissue into a disseminated therapy-resistant lethal disease. In clinical terms this process consists of three major steps (Fig. 1): () the transition from regulated to deregulated cell proliferation, () the emerging ability of the neoplastic cell collectives to induce angiogenesis and to invade other tissues, () the development of metastases and of resistance towards anti-tumor therapies.
Evidence for and Against Hypoxia as the Primary Cause of Tumor Aggressiveness
2003
In clinical trials, tumor hypoxia has consistently been associated with tumor aggressiveness. The evidence for an association between hypoxia and metastasis and more rapid tumor progression and death is seen in uterine cervical cancer, and sarcoma of soft tissue. Evidence is building in prostate, vulva, head and neck, and breast cancers. A major question is whether hypoxia precedes tumor aggressiveness or whether aggressive tumors incidentally are also hypoxic.
A minireview on NHE1 inhibitors. A rediscovered hope in oncohematology.
2015
Background: Na+/H+ exchanger-1 (NHE-1) is involved in pH regulation and is up-regulated in different malignancies. Activation of NHE-1 is one way for allowing cells to avoid intracellular acidification and protect them against apoptosis. Inhibitors of NHE-1 are able to decrease intracellular pH and induce apoptosis. Some statins can also act by partial inhibition of NHE-1. This review presents progress in understanding the mechanisms of action of these inhibitors, connections with certain genetic mutations and acquired treatment resistance, as well as new patents on them. Methods: A MEDLINE search for original and review articles using key terms, Na+/H+ exchanger, leukemia, cariporide, and …
Tumor Oxygenation Under Normobaric and Hyperbaric Hyperoxia
1997
Tumor hypoxia is an important factor limiting the efficiency of sparsely ionizing ra-diation and O2-dependent chemotherapy. Since the tumor pO2 is the result of a dynamic steady state between oxygen supply and O2 consumption of the tumor tissue, hypoxia could be reduced either by increasing the O2-supply or by reducing the O2 demand of the tumor cells. The O2 supply can be improved for instance by (i) increasing the arterial oxy-gen partial pressure, (ii) improving (and homogenizing) the tumor perfusion, or (iii) en-hancing the O2 release from blood into the tissue by right-shifting the HbO2 dissociation curve. Theoretically, it should also be possible to improve tumor oxygenation by a rela…
Relationship between hemoglobin levels and tumor oxygenation
2008
Tissue hypoxia is a powerful and independent adverse prognostic factor in solid tumors. As outlined in Chapter 11, one major factor causing tumor hypoxia is a decreased O2 transport capacity of the blood resulting from tumor-associated and/or therapy-induced anemia, which is a frequent complication seen in cancer patients (Ludwig et al. 2004; Birgegard et al. 2005).