Thesis (M.A.)--Boston University

All the evidence contained in the investigation of 722 junior high school students points to the fact that there is no connection between the speed of writing and handedness; between the amount of written material produced in 5-minute themes and handedness; and between the effects of writing on subjective evaluations of 5-minute written themes and handedness. The figures show that the incidence of handicap in writing is approximately the same for both right- and left-handed groups. / Arts, Faculty of / Psychology, Department of / Graduate

Left ventricular hypertrophy (LVH) is more frequently associated with LV dilatation and systolic chamber dysfunction in males than in females. The mechanisms of this effect are uncertain. As excessive adrenergic stimulation may be responsible for LV dilatation and systolic chamber dysfunction in hypertension, in my dissertation I aimed to assess whether gender determines the adverse effects on LV chamber remodeling following 6 months of daily β-adrenergic receptor (AR) stimulation (isoproterenol [ISO] at 0.04 mg.kg-1day-1) in spontaneously hypertensive rats (SHR). LV dilatation was assessed in vivo from LV end diastolic diameter (EDD) (echocardiography) and ex vivo from the volume intercept at 0 mm Hg pressure (V0) of the LV diastolic pressure-volume relationship (isolated, perfused heart technique). LV systolic function was determined in vivo from LV endocardial fractional shortening (FSend) and ex vivo from the slope (LV end systolic elastance [LV Ees]) of the LV end systolic pressure-volume relationship (isolated, perfused heart technique). As compared to saline-treated male SHR (n=13), male SHR receiving ISO for 6 months (n=13) developed an increased LV EDD (Male Saline: 6.56±0.20 mm; Male ISO: 7.78±0.29 mm; p<0.05) and LV V0 (Male Saline: 0.22±0.01 ml; Male ISO: 0.31±0.02 ml; p<0.05). In contrast, ISO administration failed to modify LV EDD (Female Saline, n=13: 6.06±0.15 mm; Female ISO, n=12: 6.33±0.15 mm) or LV V0 (Female Saline: 0.17±0.01ml; Female ISO: 0.17±0.01 ml) in female SHR. In addition, there was a gender-ISO interactive effect on LV Ees (p<0.05; Male Saline: 2268±336 mmHg.ml-1; Male ISO: 1623±164 mmHg.ml-1; Female Saline: 1910±219 mmHg.ml-1; Female ISO: 2302±230 mmHg.ml-1). In conclusion, as compared to female SHR, male SHR are more susceptible to the adverse effects of chronic β-AR activation on LV cavity dimensions and systolic chamber function. These results suggest that the higher prevalence of LV dilatation and systolic chamber dysfunction in males than in females with LVH may be attributed to an increased susceptibility to the adverse effects of adrenergic stimulation.

No description available.

No description available.

No description available.

No description available.

<p>Knowledge of the leftventricular (LV) pressure-volume relation, along withparameters derived from this relation, have led to newpossibilities for the characterisation of cardiac pumpfunction, in both experimental studies and clinicalsettings.</p><p>The pressure-volume diagram is apowerful tool for visualising LV performance, but in order tobe clinically useful it is necessary to make plots continuouslyand on-line. The conductance catheter technique offers thispossibility. The conductance catheter system has experiencedgrowing interest among cardiologists, physiologists, surgeons,and anaesthesiologists around the world as a powerful newresearch tool, but the invasiveness of this technique has beena limiting factor for most clinical applications. The catheterneeds to be thinner and softer in order to make this techniquemore suitable for human use.</p><p>This thesis reports of a newthin and soft conductance catheter for continuously and on-linemeasurements of LV pressure and volume.</p><p>One way to reduce both cathetersize and stiffness is to decrease the number of electrodes onthe catheter. Theoretical calculations shown in this thesisproves that it is possible to obtain the same performance witha single segment catheter as with a five-segment catheter. Thethin catheter has been tested and compared to a commercialfive-segment conductance catheter in animal studies.</p><p>We conclude that the thin singlesegment conductance catheter can measure left ventricularvolume and pessure. The regression coefficient between the twomethods is good independent of loading condition and duringbaseline conditions the catheters produce very similar volumecurves. During preload reduction the estimated volume reductionis different in the two systems.</p><p>Our thin catheter does notdisturb the heart's normal electrophysiology, neither by thecatheter current nor by any mechanical stimuli. The resultsdemonstrates that our thin, soft, single segment conductancecatheter has performance characteristics which warrant furtherdevelopment, with the goal to make the method available forhuman use.</p>

No description available.

Thesis (Ed.D.)--Teachers College, Columbia University, 1970. / Typescript; issued also on microfilm. Sponsor: Paul E. Eiserer. Dissertation Committee: Anne Selley McKillop. Includes bibliographical references.