- 13C-methionine breath test detects distinct hepatic mitochondrial dysfunction in HIV-infected patients with normal serum lactate. Banasch, M., Goetze, O., Hollborn, I., Hochdorfer, B., Bulut, K., Schlottmann, R., Hagemann, D., Brockmeyer, N.H., Schmidt, W.E., Schmitz, F. J. Acquir. Immune Defic. Syndr. (2005)