Prediction of motor outcome using remaining corticospinal tract in patients with pontine infarct: Diffusion tensor imaging study

The aim of this study was to investigate the relationship between the remaining corticospinal tract (CST) as determined by diffusion tensor imaging (DTI) and 6-month motor outcome in patients with pontine infarct. Ratios of fractional anisotropy (FA), fiber number (FN), and CST area were calculated, and the FN ratio and CST area ratio showed significant correlation with all 6-month motor outcome. Thus, the remaining CST in the pons measured using DTI at early stage of stroke could predict motor outcome in patients with pontine infarct.     

Measurement of water fluxes and potentials in a single root-soil system

Summary The construction and operation of a novel tensiometer-potometer system capable of measuring the xylem water potential and flux of water into the root is described. The validity of its measurements has been illustrated and it was shown that a unique linear relationship exists between the resistance to water flow and the water status of the root tissues.     

Quantitative relationship between the protein secondary structure in cardiac sarcolemma and the activity of the membrane-bound Ca2+-ATPase

In the absence of ATP, increasing concentrations of calcium within a range between 0.1--8.0 mmol . 1(-1) gradually lowered the alpha-helix content of proteins in rat heart sarcolemma requiring no energy supply. In the presence of ATP, similar concentrations of calcium stepwise activated the sarcolemmal low-affinity Ca2+-ATPase. A mathematical analysis of the data obtained revealed a quantitative relationship between calcium-induced stimulation of the Ca2+-ATPase activity and a diminution of the alpha-helix contents of membrane proteins in cardiac sarcolemma. The cooperation between changes in protein conformation and energy consumption in relation to the supposed role of low-affinity Ca2+-ATPase in gating the calcium channel are discussed.     

Age-dependent changes in the distribution and concentration of human lens cholesterol and phospholipids

Analyses of total lipid in individual lenses 1.8-63 years of age indicate that both the cholesterol and the phospholipid concentrations have reached a high level of 10 and 14 micrograms/mg lens dry weight, respectively, after the first ten years of growth. Thereafter, the rate of phospholipid accumulation was greatly reduced to a value of 0.05 microgram/mg per year while that of cholesterol reduced to 0.19. Analyses of the distribution of lipid in successive lens fiber layers indicate that both the cholesterol and phospholipid levels increase in the entire lens between the age of 1.8 and 9 years. Older lenses showed a continuous increase in the accumulation of cholesterol in the deep cortical fibers, while little or no increase in phospholipid concentration was observed. These results indicate that the accumulation of lipids is greater than that of lens dry mass (protein) during the first decade of lens growth. Since more than 90% of lenticular lipids are associated with fiber cell membranes, these data suggest a gradual change in the differentiation of the newly formed secondary fibers from the epithelium during this period. Analyses of the phospholipid composition of the successive fiber fractions indicate that the major phospholipids of phosphatidyl ethanolamine (PE), phosphatidylserine (PS) and sphingomyelin maintained a uniform distribution in the 1.8- and 5-year-old lenses. While no change was observed with the cortical fibers, older lenses showed a gradual loss of PE and PS in the nuclear fiber up to 63 years of age. By the late teen years, nuclear PS can no longer be detected, while high levels of PE are maintained in lens nucleus. The disappearance of nuclear PE begins in the teen years and is completed by the age of 40. The decrease in PE and PS resulted in a continuous increase in the cholesterol/phospholipid ratio, a measure of membrane rigidity in the nuclear fiber in lenses 20 years of age and older. This decrease is also responsible for the exceedingly high rigidity of the nuclear fibers of lenses 60 years of age and older. Possible lamellar cholesterol organization in the lens fiber membrane is discussed.