Search results for "oxygenation"
showing 10 items of 237 documents
Hypoxia and Aggressive Tumor Phenotype: Implications for Therapy and Prognosis
2008
Abstract Tumor hypoxia, mostly resulting from poor perfusion and anemia, is one of the key factors in inducing the development of cell clones with an aggressive and treatment-resistant phenotype that leads to rapid progression and poor prognosis. Studies in patients with solid tumors suggest that there is a range of hemoglobin (Hb) concentrations that is optimum for tumor oxygenation. When used to achieve an Hb level within this range, erythropoiesis-stimulating agents (ESAs) can be expected to increase tumor oxygenation, and this may favorably influence sensitivity to treatment as well as quality of life. There is no robust evidence that ESAs, when used as indicated, have a negative effect…
Prognostic Potential Of The Pretherapeutic Tumor Oxygenation Status
2009
Hypoxia, a characteristic feature of locally advanced solid tumors, has emerged as a key factor of the tumor pathophysiome, since it can promote tumor progression and resistance to therapy. Independent of established prognostic parameters, such as clinical tumor stage, histology, histological grade and nodal status, hypoxia has been identified as an adverse prognostic factor for patient outcome. Studies of pretreatment tumor hypoxia involving direct assessment (polarographic oxygen tension measurements) have suggested a poor prognosis for patients with hypoxic tumors. These investigations indicate a worse disease-free survival for patients with hypoxic cancers of the uterine cervix or soft …
Detection and characterization of tumor hypoxia using pO2 histography.
2007
Data from 125 studies describing the pretreatment oxygenation status as measured in the clinical setting using the computerized Eppendorf pO2 histography system have been compiled in this article. Tumor oxygenation is heterogeneous and severely compromised as compared to normal tissue. Hypoxia results from inadequate perfusion and diffusion within tumors and from a reduced O2 transport capacity in anemic patients. The development of tumor hypoxia is independent of a series of relevant tumor characteristics (e.g., clinical size, stage, histology, and grade) and various patient demographics. Overall median pO2 in cancers of the uterine cervix, head and neck, and breast is 10 mm Hg with the ov…
Blood flow and oxygenation status of human tumors. Clinical investigations.
1999
There is a large body of evidence suggesting that blood flow and oxygenation of human tumors are important research topics which may explain, in particular, resistance to radiation and to many antineoplastic drugs, which can limit the curability of solid tumors by radiotherapy and chemotherapy.This manuscript reviews the clinical investigations which have been performed regarding blood flow and oxygenation status of human tumors in radiation oncology.The possible uses and limitations of the prognostic significance and the changes under therapy measuring blood flow and oxygenation in human tumors were discussed. In addition, several approaches were summarized, which can improve the microvasc…
The Role of Oxygen Tension Distribution on the Radiation Response of Human Breast Carcinoma
1994
The response of tumors to radiation is heterogeneous even in animal tumor systems where tumors all originate from the same cell culture, are implanted in genetically similar age-matched animals in a constant anatomic locationl. Hence great heterogeneity of response exists even in situations where intrinsic genetic or epigenetic factors are minimally variable. Several metabolic factors are known to influence the probability of tumor control after radiation. These metabolic factors are also known to vary widely between tumors in humans2,3 and even in animal tumor models. Heterogeneous variables include tumor oxygen tension distribution, glutathione content, glucose delivery and utilization ra…
Oxygenation of Mammary Tumors: From Isotransplanted Rodent Tumors to Primary Malignancies in Patients*
1992
The role of oxygen in tumor cell proliferation, radiosensitivity, cytotoxicity of anticancer drugs and hyperthermia treatment has been the subject of a series of investigations (for reviews see Hall, 1988; Teicher et al., 1990, Vaupel et al., 1989a; Vaupel, 1990a,b). Despite the apparent importance of tumor oxygenation, data on pO2 values in solid tumors are mostly derived from experiments on rodents which might not necessarily reflect the variability of the clinical situation. Due to feasible techniques available now, considerable advances have been made in the past few years in the assessment of tumor hypoxia in patients (for reviews see Vaupel et al., 1989a; Vaupel, 1990a). The latter in…
Intratumoral PO2 Histography as Predictive Assay in Advanced Cancer of the Uterine Cervix
1994
Experimental evidence suggests that the hypoxic fraction in a solid tumor may increase its malignant potential and reduce its sensitivity towards nonsurgical treatment modalities such as standard irradiation and certain anticancer agents1–5. However, the clinical importance of tumor hypoxia remains uncertain since valid methods for the routine measurement of intratumoral O2-tensions in patients have so far been lacking.
High flow nasal therapy in perioperative medicine: from operating room to general ward
2018
Abstract Background High flow nasal therapy (HFNT) is a technique in which humidified and heated gas is delivered to the airways through the nose via small nasal prongs at flows that are higher than the rates generally applied during conventional oxygen therapy. The delivered high flow rates combine mixtures of air and oxygen and enable different inspired oxygen fractions ranging from 0.21 to 1. HFNT is increasingly used in critically ill adult patients, especially hypoxemic patients in different clinical settings. Main body Noninvasive ventilation delivers positive pressure (end-expiratory and inspiratory pressures or continuous positive airway pressure) via different external interfaces. …
Traditional Chinese herbal medicine at the forefront battle against COVID-19: Clinical experience and scientific basis.
2020
Abstract Background Throughout the 5000-year history of China, more than 300 epidemics were recorded. Traditional Chinese herbal medicine (TCM) has been used effectively to combat each of these epidemics’ infections, and saved many lives. To date, there are hundreds of herbal TCM formulae developed for the purpose of prevention and treatment during epidemic infections. When COVID-19 ravaged the Wuhan district in China in early January 2020, without a deep understanding about the nature of COVID-19, patients admitted to the TCM Hospital in Wuhan were immediately treated with TCM and reported later with >90% efficacy. Approach We conducted conduct a systematic survey of various TCM herbal pre…
Quantitative Topography of the Hemodynamic-Oxidative Metabolic Interrelation by Multispot Measurement Approach in Rat Ischemia Models
2001
We applied the multispot measurement approach for both laser Doppler (LD) and a microspectrophotometric method to measure local cerebral blood flow (1CBF) and local tissue hemoglobin oxygenation (IHbO2). We demonstrated that the current technology permits in vivo observation, allowing us to establish a close topographical relation between CBF and HbO2. We measured 1CBF by LD flowmetry and tissue HbO2 by a microspectrophotometric method at multiple corresponding locations using a “scanning” technique that employs a computer-controlled micromanipulator. CBF and HbO2 data from predefined locations were correlated to the topographical situation and then arranged in a three-dimensional (3D) imag…