An investigation of pulsatile flow in a model cavo-pulmonary vascular system

2009 ◽  
Vol 25 (11) ◽  
pp. 1061-1083 ◽  
Author(s):  
K. Chitra ◽  
S. Vengadesan ◽  
T. Sundararajan ◽  
P. Nithiarasu
Keyword(s):  
Pulsatile Flow ◽  
Vascular System

A Scanning Electron Microscopic Study of Pro-Vascular Cellular Morphology in Chaetophora Incressata

1985 ◽  
Vol 43 ◽  
pp. 638-639
Author(s):  
A. E. Hotchkiss ◽  
A. T. Hotchkiss ◽  
R. P. Apkarian
Keyword(s):  
Green Algae ◽  
Vascular Plants ◽  
Vascular System ◽  
Higher Plants ◽  
Wall Structure ◽  
Electron Microscopic ◽  
Physiological Processes ◽  
Scanning Electron Microscopic Study ◽  
Scanning Electron Microscopic ◽  
Scanning Electron

Multicellular green algae may be an ancestral form of the vascular plants. These algae exhibit cell wall structure, chlorophyll pigmentation, and physiological processes similar to those of higher plants. The presence of a vascular system which provides water, minerals, and nutrients to remote tissues in higher plants was believed unnecessary for the algae. Among the green algae, the Chaetophorales are complex highly branched forms that might require some means of nutrient transport. The Chaetophorales do possess apical meristematic groups of cells that have growth orientations suggestive of stem and root positions. Branches of Chaetophora incressata were examined by the scanning electron microscope (SEM) for ultrastructural evidence of pro-vascular transport.

Protective Effects of Pulsatile Flow during Cardio-Pulmonary Bypass

2016 ◽  
Vol 64 (S 02) ◽  
Author(s):  
A. Salameh ◽  
L. Kuehne ◽  
M. Grassl ◽  
M. Gerdom ◽  
S. von Salisch ◽  
...  
Keyword(s):  
Pulsatile Flow ◽  
Protective Effects ◽  
Cardio Pulmonary Bypass ◽  
Pulmonary Bypass

Lasertechniques treatment of vascular malformations

Phlebologie ◽  
2010 ◽  
Vol 39 (03) ◽  
pp. 167-175
Author(s):  
M. Poetke ◽  
P. Urban ◽  
H.-P. Berlien
Keyword(s):  
Endothelial Cells ◽  
Spontaneous Regression ◽  
Vascular System ◽  
Vascular Malformations ◽  
Clinical Importance ◽  
Vascular Structure ◽  
Laser Application ◽  
Vascular Morphogenesis ◽  
Structural Abnormalities

SummaryVascular malformations are structural abnormalities, errors of vascular morphogenesis, which can be localized in all parts of the vascular system. All vascular malformations by definition, are present at birth and grow proportionately with the child; their volume can change. In contrast to the haemangiomas, which only proliferate from the endothelial cells the division in stages is of clinical importance. Vascular malformations are divided from the part of vascular system, which is affected.In principle the techniques of laser application in congenital vascular tumours like haemangiomas and in vascular malformations are similar, but the aim is different. In tumours the aim is to induce regression, in vascular malformations the aim is to destroy the pathologic vascular structure because there is no spontaneous regression. This means that the parameters for treatment of vascular malformations must be more aggressive than for vascular tumours.

Adrenergic Stimulation of Regional Plasminogen Activator Release in Rabbits

1992 ◽  
Vol 68 (05) ◽  
pp. 545-549 ◽  
Author(s):  
W L Chandler ◽  
S C Loo ◽  
D Mornin
Keyword(s):  
Lower Extremity ◽  
Plasminogen Activator ◽  
Beta Blocker ◽  
Time Course ◽  
Vascular System ◽  
Adrenergic Stimulation ◽  
Epinephrine Administration ◽  
Adrenergic Antagonist ◽  
Vascular Beds ◽  
Stimulation Of

SummaryThe purpose of this study was to determine whether different regions of the rabbit vascular system show variations in the rate of plasminogen activator (PA) secretion. To start, we evaluated the time course, dose response and adrenergic specificity of PA release. Infusion of 1 µg/kg of epinephrine stimulated a 116 ± 60% (SD) increase in PA activity that peaked 30 to 60 s after epinephrine administration. Infusion of 1 µg/kg of norepinephrine, isoproterenol and phenylephrine had no effect on PA activity. Pretreatment with phentolamine, an alpha adrenergic antagonist, blocked the release of PA by epinephrine while pretreatment with the beta blocker propranolol had no effect. This suggests that PA release in the rabbit was mediated by some form of alpha receptor.Significant arterio-venous differences in basal PA activity were found across the pulmonary and splanchnic vascular beds but not the lower extremity/pelvic bed. After stimulation with epinephrine, PA activity increased 46% across the splanchnic bed while no change was seen across the lower extremity/pelvic bed. We conclude that several vascular beds contribute to circulating PA activity in the rabbit, and that these beds secrete PA at different rates under both basal and stimulated conditions.

A Study of Doppler Waveform Using Pulsatile Flow Model

1997 ◽  
Vol 37 (2) ◽  
pp. 225 ◽  
Author(s):  
Hye Won Chung ◽  
Myung Jin Chung ◽  
Jae Hyung Park ◽  
Jin Wook Chung ◽  
Dong Hyuk Lee ◽  
...  
Keyword(s):  
Pulsatile Flow ◽  
Flow Model ◽  
Doppler Waveform

Enzymic Correlates of Development, Secretory Function and Regression of Follicles and Corpora Lutea in the Bovine Ovary. PART II: Formation, Development and Involution of Corpora Lutea

1968 ◽  
Vol 59 (2_Suppl) ◽  
pp. S35-S51 ◽  
Author(s):  
B. L. Lobel ◽  
E. Levy
Keyword(s):  
Corpus Luteum ◽  
Vascular System ◽  
Hydrolytic Enzymes ◽  
Sharp Decrease ◽  
Cellular Growth ◽  
Corpora Lutea ◽  
Cell Nuclei ◽  
Steroid Synthesis ◽  
Luteal Cells ◽  
Vascular Walls

ABSTRACT Activities of various hydrolases and dehydrogenases were studied during the formation, development and involution of cyclic corpora lutea and in the corpora lutea of early pregnancy. At 24 hours postovulation the luteal cells, whether of granulosal or thecal origin, contained demonstrable levels of Δ5-3β-hydroxysteroid dehydrogenase and the NADP and NADPH2 diaphorases. During the period of proliferation and cellular growth, enzymic activities in the luteal cells were moderate at first, and then increased. In the mature corpus luteum, activities of the dehydrogenases occurred in all luteal cells but were most intense in the large polymorphic luteal cells. Activities of hydrolytic enzymes, low in the immediate postovulatory period, increased with the development of the vascular system. Enzymic characteristics of corpora lutea of gestation were similar to those of cyclic corpora, except for phosphorylase activity which was observed in luteal cells in gestational corpora, but confined to the vascular walls in cyclic corpora. No increase in activities of 17β- and 20β-hydroxysteroid dehydrogenases (above those seen in pre-ovulatory follicles) were observed after incubation of sections of either mature cyclic or gestational corpora. Involution of cyclic corpora lutea began with degenerative changes in the blood vessels: pyknosis of the endothelial cell nuclei and a sudden decline in activities of hydrolytic enzymes in the vascular walls. Subsequently, the luteal cells showed a sharp decrease in activities of the dehydrogenases as well as other signs of regressive change. The cytochemical findings are discussed in relation to biochemical observations on steroid synthesis by the bovine corpus luteum.

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