Coronary collateral vessels reduce damage to ischemic myocardium after coronary obstruction. Factors that stimulate collateral formation are expected to have ameliorating effects on myocardial infarction. In a canine experimental myocardial infarct model, intracoronary injection of basic fibroblast growth factor (bFGF) improved cardiac systolic function and reduced infarct size. Treatment with bFGF increased the number of arterioles and capillaries in the infarct. Thus, the angiogenic action of bFGF might lead to a reduction in infarct size. The application of bFGF might bring about a therapeutic modality for the salvage of infarcted myocardium.

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par Le Bret. On différencie d'abord les régions diluée et semidiluée de ces solutions. On sépare ensuite la région semidiluée en trois régimes, qui sont, par ordre de concentration décroissante, les régimes isotrope, de transition et de réseau. On sépare aussi la région diluée en deux régimes, l'un ordonné et l'autre désordonné. Les régimes isotrope et de réseau ont été décrits par de Gennes, et le régime de transition par Odijk. Les régimes ordonné et désordonné peuvent être distingués selon l'existence de corrélations causées par les répulsions électrostatiques. On utilise la diffusion des rayons X aux petits angles pour confirmer la concentration du passage dilué-semidilué dans des solutions de poly(styrène sulfonate) de sodium. D'autre part, une analyse préliminaire de la distribution des distances confirme la concentration de fusion C*m entre les régimes isotrope et de transition. A présent nous n'avons pas d'information sur le passage entre les régimes de réseau et de transition, ni sur le passage ordonné-désordonné.

The structure of poly(vinyl alcohol) (PVA) gels formed in a mixture of deuterated dimethyl sulfoxide (DMSO-de) and heavy water at 23 °C has been investigated by wideand small-angle neutron scattering techniques. It was directly confirmed from the wide-angle neutron scattering measurements that cross-linking points or junction points in the gels are crystallites. In the small-angle scattering measurements, it was found that the scattering intensity I(Q) decreases with Q according to the -4th power law (Porod's law) in the Q range above 0.05 A-1 where Q = 4 sin 6/ (26 and are scattering angle and wavelength of neutron, respectively), suggesting that the surface of the crystallites has a clear boundary. On the other hand, the Q dependence of the scattering intensity 7(Q) can be described by 7(0)/[l + £2Q2] in the Q range below 0.035 A-1, where £ is a correlation length. The correlation length £ was assigned to the average distance between the neighboring crystallites. Distance distribution function P(r) which is defined by inverse Fourier transformation of scattering intensity 7(Q) was also calculated in order to see another aspect of the scattering intensity. Two peaks or shoulders at about 70 and 200 A were recognized in the calculated P(r). The former and the latter have been attributed to the intraand intercrystallite correlations, respectively. By separating the two correlations, the distribution of the crystallites is discussed.

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