With the broadening of its diagnostic criteria of recent years, cases of MFH (malignant fibrous histiocytoma) have been on the increase, and its clinical feature also has come to greatly diversify. Nothing truly convincing has, however, been reported as regard the therapy effective against this particular disease.Eight cases have so far been diagnosed as MFH by this Department since 1978, and the patients so diagnosed were aged from 19to 72, or 44 years old on the average.Of the eight cases, three were located at the proximal portion of thigh, two at the distal portion of thigh, one near the knee, one at the proximal portion of upper arm, and one at the retroperitoneum, of which two were regarded as being of bone origin.For the purpose of reducing the local focus activity as well as of preventing the recurrence of the disease, the radiation therapy with about 4000 to 6000 Rad. has been administered on the patients by this Department before and after the surgery.Comparative studies made, principally, of observations which were obtained before and after the radiation therapy performed on the patients show that this radiation method of treatment can be expected to offer a considerable local effectiveness in some particular instances.
To develop advanced structural materials at very high temperatures, ball milling followed by reactive hot pressing was employed to fabricate binary Nb/Nb-silicide in-situ composites with 3.5 to 16 mol% silicon content. Changes in morphology during milling of niobium and silicon elemental powders were studied, and microstructures and mechanical properties of reactively hot pressed composites were evaluated by OM, SEM, XRD, DTA and EPMA. No detectable niobium silicide was formed during milling. Reactive hot pressing of the milled powders yields two kinds of silicides, Nb3Si and Nb5Si3, through in-situ reaction between heavily deformed niobium particles and fragmented silicon particles. DTA revealed that silicide formation occurs at 940 K for Nb3Si and 1050 K for Nb5Si3. Fully dense Nb/Nb-silicide in-situ composites with equiaxed grain microstructures are produced by the reactive hot pressing of milled powders. All of the composites exhibit considerable compressive ductility without cracking even at room temperature. Annealing at high temperature results in growth of equiaxed grains of niobium and silicide, thereby increasing high temperature strength.
We aimed to develop an argumentative writing strategy use scale for fifth–sixth-grade elementary students. The Study 1 results (N=426) indicated that the strategy can be classified based on five factors: reader awareness, consideration of opposing views, flow of composition, expressing one’s position, and proofreading. The content validity of this scale was examined by comparing the use of strategy between those with high and low subjective frequency or self-efficacy for writing essays. The results showed that the score for each strategy increased under both conditions, thereby indicating a degree of validity for the scale. Study 2 examined the relationship between the writing strategies for and evaluation of essays. Strategy use scores increased in the high essay quality group, rather than their low counterparts for three strategies: reader awareness, flow of composition, and expressing one’s position. Future research should examine whether essay quality can be improved by implementing the scale.
The effects of gallopamil, D600, a methoxy derivative of verapamil, on the mechanical and electrophysiological parameters of isolated guinea-pig myocardial preparations were compared with those of verapamil. Both gallopamil and verapamil produced concentration-dependent negative chronotropic and negative inotropic effects in isolated right atrial and right ventricular papillary muscles, respectively. The negative chronotropic and negative inotropic potencies of gallopamil were 7.2 and 4.3 times higher than those of verapamil, respectively. Gallopamil decreased the action potential duration of isolated papillary muscles without substantially affecting other action potential parameters, while verapamil decreased not only the action potential duration but also the maximum rate of rise and amplitude. In voltage-clamped single ventricular myocytes, gallopamil as well as verapamil decreased the L-type Ca2+ current amplitude. The potency orders for the shortening of the action potential duration and inhibitory effects of the L-type Ca2+ current amplitudes were verapamil > gallopamil. These results indicate that gallopamil has higher negative chronotropic and inotropic potency than verapamil as a result of factors other than L-type Ca2+ current inhibition.
In organ culture conditions, in the absence of in vivo factors, the newborn rat right atria acquire a high sensitivity to agonists similar to that seen before sympathetic innervation and after denervation. In the present study, we examined the effects of various extracts and substances on the development of supersensitivity to norepinephrine (NE) to obtain information on the in vivo factors that regulate myocardial sensitivity. Addition of rat serum, right atrial extract, superior cervical ganglionic extract, vas deferens extract, carbachol, insulin, cortisone, thyroxin, and neuropeptide Y in the culture medium did not prevent the development of supersensitivity. Addition of NE completely inhibited the development of supersensitivity. This effect of NE was blocked by sotalol but not by phentolamine. Addition of calcitonin gene related peptide, forskolin, and 8-bromo-cAMP partially inhibited the development of supersensitivity. These results are consistent with the view that NE released from sympathetic nerve terminals in the newborn atria maintains myocardial sensitivity at normal level by acting on beta-adrenergic receptors, and that the effect may be partially mediated by a rise in intracellular cAMP concentration.
Effect of abdominal aorto-venocaval shunt (AVS) on the automaticity of the pulmonary-vein myocardium was studied in the rat. Spontaneous electrical activity was observed in one third of the isolated pulmonary-vein preparations from the AVS rats, but scarcely in those from sham-operated rats; the activity was induced by tertiapin and suppressed by carbachol or chelation of intracellular Ca2+. The evoked action potentials in AVS rats had less negative resting membrane potential and longer action potential duration than those in sham-operated rats. These results suggest that the automaticity of the rat pulmonary-vein myocardium is manifested under chronic volume overload.
