Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Crystallization and preliminary X-ray diffraction analysis of a cold-adapted catalase from Vibrio salmonicida

Monoclinic (P21) crystals of a His-tagged form of V. salmonicida catalase without cofactor diffract X-rays to 1.96 Å

Use of interferon gamma-based assay to diagnose tuberculosis infection in health care workers after short term exposure

<p>Abstract</p> <p>Background</p> <p>We intended to assess the risk for health care workers (HCWs) of acquiring <it>M. tuberculosis </it>infection after exposure to patients with sputum-smear positive pulmonary tuberculosis at three University Hospitals (Ullevål, Akershus, and Haukeland) in Norway.</p> <p>Methods</p> <p>We tested 155 exposed health care workers and 48 healthy controls both with a tuberculin skin test (Mantoux) and the T-SPOT.<it>TB </it>test, a recently developed interferon-γ release assays based on the <it>M. tuberculosis</it>-specific ESAT-6 and CFP10 antigens, to investigate if this test might improve infection control measures.</p> <p>Results</p> <p>Among the 155 exposed HCWs tested in this study, 27 individuals were defined as newly infected cases by TST after recent exposure, while only 3 of these had a positive T-SPOT.<it>TB </it>test. The number of T-SPOT.<it>TB </it>positives represents 11% of the individuals defined as recently infected by TST after exposure (3/27) and 2% of the total number of exposed people tested (3/155). In addition, 15 individuals had been previously defined as infected by TST before exposure of whom 2 subjects were T-SPOT.<it>TB </it>positive. All individuals detected as T-SPOT.<it>TB </it>positive belonged to the TST positive group (> 15 mm), and the percentage concordance between T-SPOT.<it>TB </it>and TST, including both previously and newly infected subjects, was 12% (5/42). The 48 control participants used in the study were all T-SPOT.<it>TB </it>negative, but 3 of these subjects were TST positive.</p> <p>Conclusion</p> <p>Our data indicate that the frequency of latent TB in the total cohort of HCWs is 3%, whereas the rate of transmission of TB to exposed individuals is approximately 2% and occurs through exposure periods of short duration. Thus, the risk of TB transmission to HCWs following TB exposure in a hospital setting in Norway is low, and improved screening approaches will benefit from the application of specific interferon-γ release assays.</p