Chaperonin genes on the rise: new divergent classes and intense duplication in human and other vertebrate genomes

Background  

Chaperonin proteins are well known for the critical role they play in protein folding and in disease. However, the recent identification of three diverged chaperonin paralogs associated with the human Bardet-Biedl and McKusick-Kaufman Syndromes (BBS and MKKS, respectively) indicates that the eukaryotic chaperonin-gene family is larger and more differentiated than previously thought. The availability of complete genome sequences makes possible a definitive characterization of the complete set of chaperonin sequences in human and other species.     

Effect of O2, N2, and CO2 composition on nonlinearity of Fleisch pneumotachograph characteristics

Although the Fleisch pneumotachograph has many advantages, its flow-conductance characteristics are nonlinear and sensitive to changes in gas composition. The purpose of this study was to assess the effect of different O2, N2, and CO2 compositions on the nonlinearity of the Fleisch pneumotachograph flow-conductance characteristics, by use of a recently developed computerized calibration method. Hospital-grade O2 was mixed with room air to obtain seven gas mixtures (containing O2 percentages of 20.9, 28.3, 38.7, 52.8, 66.7, 78.7, and 99.6%). Within the accuracy of the applied method, the measured flow-conductance curves of the pneumotachograph had the same shape. Relative flow resistance of gas mixtures to room air was directly proportional to their O2 composition. Two O2-N2-CO2 mixtures were also tested. Their relative flow resistance compared with room air was proportional to the viscosity ratios. We concluded that the change in O2, N2, and CO2 composition does not affect the nonlinearity of the Fleisch pneumotachograph flow-conductance characteristics. However, the relative flow resistance compared with room air does change in a predictable way.