摘要:

In the light of known differences in bio-chemical, histological, and biophysical characteristics of fast and slow muscle, it was thought feasible to investigate possible differences in vascular properties. The present study has shown that vascular reactivity to α-adrenergic stimulation by both topical application of catecholamines (epinephrine and norepinephrine) and reflex activation of sympathetic nerves, is graded in both fast and slow muscles from precapillary sphincters which are the most sensitive, to small and then larger arterioles. In addition, the vessels of fast muscle are more sensitive to stimulation by those agents than are the vessels of slow muscle. The vascular bed in fast muscle is characterized by vasomotion (intermittency of flow rate and pattern) and many momentarily inactive capillaries (no moving red cells) in the resting state, whereas the flow in slow muscle capillaries is much more steady and uniform

ISSN:1018-1172    

DOI:10.1159/000157902

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

The activity of enzymes, extracted from the varicose human saphenous vein and the normal bovine saphenous vein, which intervene in the metabolism of mucopolysaccharides (glycosaminoglycanhydrolases) is inhibited in vitro by the action of certain fiavonoids (o-β-hydroxyaethylrutosidea, [+] catechine and certain of its derivatives). (+) Catechine, afteroxidation, shows the strongest inhibiting effect

ISSN:1018-1172    

DOI:10.1159/000157903

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

Fibrinolysis, the breaking up of the fibrin structure of thrombi into low molecular proteins, is a new principle in the treatment of occlusion of the retinal vessels. It has been tried in occlusion of both arterial and venous trunks and branches of the central retinal area. Good results can be obtained with this technique in selected patients. Attention must be paid, however, to the contraindications to the use of streptokinase for fibrinolysis, as these may prove fatal under certain circumstances. The subjective side effects resulting from the use of an extract of cultured β-hemolytic streptococci must be observed and treated

ISSN:1018-1172    

DOI:10.1159/000157904

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

The normal ultrastructure of a large cutaneous vein of the (hind) leg is described in an introductory chapter. This mentions, inter alia, the demonstration of acid mucopolysaccharides periodically attached to collagen fibrils, the immature character of most elastic fibres in the tunica intima and tunica media, and the mature aspect of elastic tissue in the tunica adventitia. Both varicose and non-varicose venous specimens of 60 patients with varicosis were examined. Two thirds of the varices were classified as belonging to the type which we have proposed to call C-type (C for collagen) with normally developed, mature elastic tissue in the tunica adventitia, but with foci of abnormal collagen fibrils in the vicinity of smooth muscle cells. The abnormal fibrils show swelling and helical splitting, resembling the findings of Peracchia and Vassallo (1966) in thromboangiitis obliterans. Collagen fibrils with periodical cloud-like attachments are also found. The relation of the latter to a possible coarsening of the periodically attached structures with acid groups remains unclear. Less than one third of the varices are described as the type which we have proposed to call E-type (E for elastic tissue) with an immature aspect of most elastic tissue of the tunica adventitia and only sparse abnormal collagen fibrils. The E-type cases are generally advanced varices, often with some sclerosis. Five mixed cases were found, showing characteristics both of the C-type and the E-type. Especially in patients with E-type varices, abnormal collagen fibrils were found in the non-varicose specimens, too. Such fibrils could not be demonstrated in the connective tissue of inguinal skin of varicosis patients. In non-varicose venae saphenae magnae of five coronary patients abnormal collagen fibrils were abundantly found. In a control case they occurred sporadically and in the vena tibialis of cattle not at all. In varicose and non-varicose specimens of the great saphenous vein of varicosis patients the vasa vasorum may show multiple laminae densae in the endothelial basement membrane. The discussion includes remarks on a possible pathophysiological enzymic influence of the smooth muscle cells on the surrounding connective tissue.

ISSN:1018-1172    

DOI:10.1159/000157905

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

If we suppose that the smooth muscle of the vessel wall develops an additional stress when the vessel wall is stretched, a mathematical analysis shows that in the absence of a natural positive damping of the pulse wave a negative damping constant might result, whereas the propagating speed of the pulse wave will be but slightly altered. This effect occurs only when the additional stress lags behind the elastic deformation. In reality, the positive damping due to visco-elasticity will generally be greater than the negative one due to muscle activity, in such a way that the positive damping will only be reduced by the latter. But some experiments on dogs let us surmise, that the negative damping exceeded the positive one.

ISSN:1018-1172    

DOI:10.1159/000157906

出版商:S. Karger AG    

年代:1971

数据来源: Karger

ISSN:1018-1172    

DOI:10.1159/000157907

出版商:S. Karger AG    

年代:1971

数据来源: Karger

ISSN:1018-1172    

DOI:10.1159/000157908

出版商:S. Karger AG    

年代:1971

数据来源: Karger

ISSN:1018-1172    

DOI:10.1159/000157901

出版商:S. Karger AG    

年代:1971

数据来源: Karger