pH, Lactate, and Hypoxia: Reciprocity in Regulating High-Affinity Monocarboxylate Transporter Expression in Glioblastoma.

Highly malignant brain tumors harbor the aberrant propensity for aerobic glycolysis, the excessive conversion of glucose to lactic acid even in the presence of ample tissue oxygen. Lactic acid is rapidly effluxed to the tumor microenvironment via a group of plasma-membrane transporters denoted monocarboxylate transporters (MCTs) to prevent "self-poisoning." One isoform, MCT2, has the highest affinity for lactate and thus should have the ability to respond to microenvironment conditions such as hypoxia, lactate, and pH to help maintain high glycolytic flux in the tumor.

Impact of time past exercise testing on prognostic variables in heart failure.

Background: Cardiopulmonary exercise testing (CPET) is considered a standard of care in heart failure (HF). The impact that duration of time post-evaluation has on the prognostic value of CPET, however, has not been explored. The purpose of this investigation was to examine the ability of peak oxygen consumption (VO(2)) and the minute ventilation-carbon dioxide production (VE/VCO(2)) slope to predict cardiac-related events at different time intervals post CPET.

Peak VO2 and VE/VCO2 slope in patients with heart failure: a prognostic comparison.

Background: Exercise testing with ventilatory expired gas analysis has proven to be a valuable tool for assessing patients with heart failure (HF). Peak oxygen consumption (peak VO2) continues to be considered the gold standard for assessing prognosis in HF. The minute ventilation--carbon dioxide production relationship (VE/VCO2 slope) has recently demonstrated prognostic significance in patients with HF, and in some studies, it has outperformed peak VO2.

Technical considerations related to the minute ventilation/carbon dioxide output slope in patients with heart failure.

Background: The minute ventilation (VE)-carbon dioxide output (VCO(2)) relationship has recently been demonstrated to have prognostic significance in the heart failure (HF) population. However, the method by which the VE/VCO(2) slope is expressed has been inconsistent.

Methods: One hundred eighty-eight subjects, who had received diagnoses of HF, underwent exercise testing.