Ryszard S. Romaniuk

Tracts of high or low sequence divergence in the mouse major histocompatibility complex.

The K, I and S regions of the mouse major histocompatibility complex (MHC) are composed of long tracts of DNA which differ in sequence divergence. A correlation exists between the location of an MHC gene in a variable or conserved chromosomal tract and the degree of polymorphism and diversity of the proteins encoded by its alleles. Variable tracts appear to be the result of mechanisms which mutate certain coding and non‐coding sequences to the same extent and selective pressures operating on the genes.

Left ventricular mass in coronary artery disease without hypertension. Haemodynamic and angiocardiographic study.

coronary artery disease as compared to those with normal coronary arteriograms. No correlation could be found between left ventricular mass and left ventricular stroke work. Significant correlations were observed with end-diastolic tension and pressure, and a lesser correlation with end-diastolic volume, in patients with advanced coronary arteriosclerosis. Higher end-diastolic wall tension represents compensation by the Frank-Starling mechanism to maintain adequate stroke work. Increased left ventricular