Vascular manifestations of extensive thermal skin injury in rat mesentery

1964 ◽  
Vol 207 (1) ◽  
pp. 137-143 ◽  
Author(s):  
Leif Horn ◽  
Ole J. Malm
Keyword(s):  
Blood Flow ◽  
Vessel Wall ◽  
Terminal Phase ◽  
Burn Shock ◽  
Red Cell ◽  
Skin Injury ◽  
Cell Agglutination ◽  
Vascular Contractility ◽  
Rat Mesentery ◽  
Mesenteric Microcirculation

After 40% body surface area skin burns, mesenteric microcirculation revealed initially augmented vasomotion and increased epinephrine responsiveness. Lowered precapillary epinephrine thresholds persisted throughout the terminal phase of early fatalities. Animals surviving 48 hr went through a phase with elevated epinephrine thresholds. Venodilatation coexisted with precapillary constriction. Initially most capillaries were empty; a few were dilated and congested with sluggish blood flow, indicating stasis. Lowered epinephrine responsiveness appeared first on the venous side coincident with apparent relief of stasis. Whitish aggregates or "clots" were frequently observed in circulation, but sludging or red cell agglutination was virtually absent. Morphologically the small blood vessels revealed endothelial swelling and there was a tendency for leukocytes to adhere to the vessel wall, the latter feature being more pronounced in later stages of burn shock. Other hemodynamic data indicated general peripheral vasoconstriction which gradually subsided in recovering animals. The circulatory changes are not consistent with circulating "burn toxins" impairing vascular contractility but with disruption of local control of vascular smooth muscle responsiveness, resulting in decompensatory venodilatation.

Effects of NO-Donors on Thrombus Formation and Microcirculation in Cerebral Vessels of the Rat

1996 ◽  
Vol 76 (01) ◽  
pp. 111-117 ◽  
Author(s):  
Yasuto Sasaki ◽  
Junji Seki ◽  
John C Giddings ◽  
Junichiro Yamamoto
Keyword(s):  
Blood Flow ◽  
Thrombus Formation ◽  
Dependent Manner ◽  
Red Cell ◽  
Cell Velocity ◽  
Red Cell Velocity ◽  
The Mean ◽  
Wall Shear ◽  
Dose Dependent

SummarySodium nitroprusside (SNP) and 3-morpholinosydnonimine (SIN-1), are known to liberate nitric oxide (NO). In this study the effects of SNP and SIN-1 on thrombus formation in rat cerebral arterioles and venules in vivo were assessed using a helium-neon (He-Ne) laser. SNP infused at doses from 10 Μg/kg/h significantly inhibited thrombus formation in a dose dependent manner. This inhibition of thrombus formation was suppressed by methylene blue. SIN-1 at a dose of 100 Μg/kg/h also demonstrated a significant antithrombotic effect. Moreover, treatment with SNP increased vessel diameter in a dose dependent manner and enhanced the mean red cell velocity measured with a fiber-optic laser-Doppler anemometer microscope (FLDAM). Blood flow, calculated from the mean red cell velocity and vessel diameters was increased significantly during infusion. In contrast, mean wall shear rates in the arterioles and venules were not changed by SNP infusion. The results indicated that SNP and SIN-1 possessed potent antithrombotic activities, whilst SNP increased cerebral blood flow without changing wall shear rate. The findings suggest that the NO released by SNP and SIN-1 may be beneficial for the treatment and protection of cerebral infarction

Blood Flow Pattern and Anastomotic Compliance for Interrupted versus Continuous Coronary Bypass Grafts

2005 ◽  
Vol 6 (2) ◽  
pp. 65 ◽  
Author(s):  
Marc Gerdisch ◽  
Thomas Hinkamp ◽  
Stephen D. Ainsworth
Keyword(s):  
Blood Flow ◽  
Vessel Wall ◽  
Coronary Bypass ◽  
Bypass Grafts ◽  
Cross Sectional ◽  
Coronary Bypass Grafts ◽  
Geometric Consistency ◽  
Suturing Technique ◽  
Suturing Techniques ◽  
Key Indicators

<P>Background: Use of the interrupted coronary anastomosis has largely been abandoned in favor of the more rapid continuous suturing technique. The Coalescent U-CLIP anastomotic device allows the surgeon to create an interrupted distal anastomosis in the same amount of time that it would take to create a continuous anastomosis. This acute bovine study examined the effect of the anastomotic technique on blood flow and vessel wall function. </P><P>Methods: End-to-side coronary anastomoses were created in an open chest bovine model using the left and right internal thoracic arteries and the left anterior descending coronary artery. All other variables except suturing technique were carefully controlled. In each animal, one anastomosis was completed using a continuous suturing technique and the other was performed in an interrupted fashion using the Coalescent U-CLIP anastomotic device. Volumetric flow curves through each graft were analyzed using key indicators of anastomotic quality, and anastomotic compliance was evaluated using intravascular ultrasound. Luminal castings were created of each vessel to examine the interior surface of each anastomosis for constrictions and deformities. </P><P>Results: The interrupted anastomoses created with the Coalescent U-CLIP anastomotic device showed significant differences with respect to anastomotic compliance, pulsatility index, peak flow, and percentage of diastolic flow. The cross-sectional area and degree of luminal deformity were also different for the two suturing techniques. </P><P>Conclusions: In this acute bovine model, interrupted coronary anastomoses demonstrated superior geometric consistency and greater physiologic compliance than did continuously sutured anastomoses. The interrupted anastomosis also caused fewer disturbances to the flow waveform, behaving similarly to a normal vessel wall. The combination of these effects may influence both acute and long-term patency of the coronary bypass grafts.</P>

Red cell agglutination, anaemia and a dermatomal rash

2019 ◽  
Vol 48 (11) ◽  
pp. 769-771
Author(s):  
Benjamin O Adeyemi ◽  
Edeghonghon Olayemi ◽  
Mahinath Bandara
Keyword(s):  
Red Cell ◽  
Cell Agglutination

Effect of Blood Viscosity on Thrombosis Potential Near a Step Wall Transition

2009 ◽  
Author(s):  
Scott C. Corbett ◽  
Amin Ajdari ◽  
Ahmet U. Coskun ◽  
Hamid N.-Hashemi
Keyword(s):  
Blood Flow ◽  
Vessel Wall ◽  
Coagulation Factors ◽  
Artificial Organs ◽  
Physical Factors ◽  
Local Geometry ◽  
Induce Platelet Aggregation ◽  
Shear Rates ◽  
Chemical Factors ◽  
Low Shear

Thrombosis and hemolysis are two problems encountered when processing blood in artificial organs. Physical factors of blood flow alone can influence the interaction of proteins and cells with the vessel wall, induce platelet aggregation and influence coagulation factors responsible for the formation of thrombus, even in the absence of chemical factors in the blood. These physical factors are related to the magnitude of the shear rate/stress, the duration of the applied force and the local geometry. Specifically, high blood shear rates (or stress) lead to damage (hemolysis, platelet activation), while low shear rates lead to stagnation and thrombosis [1].

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