Transport in rat vessel walls. II. Macromolecular leakage and focal spot size growth in rat arteries and veins

2007 ◽  
Vol 292 (6) ◽  
pp. H2881-H2890 ◽  
Author(s):  
Yixin Shou ◽  
Kung-ming Jan ◽  
David S. Rumschitzki

Transendothelial lipid transport into and spread in the subendothelial intima of large arteries, and subsequent lipid accumulation, appear to start plaque formation. We experimentally examine transendothelial horseradish peroxidase (HRP) transport in vessels that are usually, e.g., pulmonary artery (PA), or almost always, e.g., inferior vena cava (IVC), atherosclerosis resistant vs. disease prone, e.g., aorta, vessels. In these vessels, HRP traverses the endothelium at isolated, focal spots, rather than uniformly, for short circulation times. For femoral vein HRP introduction, PA spots have 30-s radii [∼53.2 μm (SD10.4); compare aorta: 54.6 μm (SD8.75)] and grow quickly from 30 s to 1 min (40%, P < 0.05) and more slowly afterward ( P > 0.05). This trend resembles the aorta, suggesting the PA has a similarly sparse intima. With carotid artery (CA) HRP introduction, the 30-s spot (132.86 ± 37.32 μm) is far larger than the PAs, grows little (∼28%, P < 0.05) from 30 to 60 s, and is much flatter than the artery curves. Transverse electron microscopic sections after ∼10 min HRP circulation show thin, intense staining immediately beneath both vessels’ endothelia with an almost step change to diffuse staining beyond. This indicates the existence of a sparse, subendothelial intima, even when there is no internal elastic lamina (IVC). This motivates a simple model that translates growth rates into lower bounds for the flow through focal leaks. The model results and our earlier wall and medial hydraulic conductivity data explain these spot growth curves and point to differences in transport patterns that might be relevant in understanding the immunity of IVC to disease initiation.

The numbers of plasmalemmal vesicles in endothelial cells of rat blood vessels were determined on electron microscopic sections. In all vessels examined which included aorta and carotid and femoral arteries, vena cava and femoral vein, and lung and brain capillaries, the numbers were of the same order of magnitude. For arteries the numbers were about double those for the corresponding veins. About one-third of all vesicles could be stained with ruthenium red after its infusion into the vessels. The results make it improbable that differences in numbers of ‘transport’ vesicles in different types of blood vessel contribute significantly to the selective accumulation of atherogenic plasma proteins in arteries.


1981 ◽  
Vol 45 (03) ◽  
pp. 276-281 ◽  
Author(s):  
S Ishimaru ◽  
E Berglin ◽  
H-A Hansson ◽  
A-C Teger-Nilsson ◽  
G William-Olsson

SummaryA segment of the inferior vena cava was replaced by an expanded polytetrafluoroethylene graft in 13 dogs. Five of them served as a control group, while the other 8 were moderately or severely defibrinogenated with subcutaneous batroxobin. Plasma fibrinogen decreased to extremely low values throughout the experiment in the defibrinogenated dogs except in the moderately treated group in which it temporarily rose to 0.72-0.87 g/1 on the first postoperative day.Scanning electron microscopic observations of the haemostatic clot formed at the anastomoses of the graft revealed no significant morphological differences in platelet adhesion and/or aggregation between the three groups. These findings confirmed that platelets play a key role in primary haemostasis during defibrinogenation.The fibrin network was slightly diminished and only short fibrin filaments could be seen in the moderately and severely defibrinogenated groups respectively. These differences in composition of the clots are discussed in relation to their haemostatic capacity.


1994 ◽  
Vol 13 (1) ◽  
pp. 40-47 ◽  
Author(s):  
C.J. Perkin ◽  
R. Stejskal

Continuous intravenous infusion allows the intended clinical dosing regime to be better evaluated during preclinical studies. Depending on the test material and vehicle, infusion for up to 6 months in primates and 12 months in beagle dogs is possible, but 28 days is the most frequent duration. Under general anesthesia, medical grade catheters are placed in the vena cava via the femoral vein, passed subcutaneously, and exteriorized between the scapulae. A jacket and tether system are used to connect the catheter to an external pump for dosing and the animals are allowed to move freely within the cages. Dosing usually commences after a 1-week recovery period. Body weight gain, food intake, and general observations indicate that the procedure does not adversely affect the normal laboratory behavior of the animals. Test article infusion periods from a few minutes up to 24 h a day, 7 days a week are used; a low infusion rate ofsaline is used for the balance of the 24-h period. Dosage volumes up to 120 ml/kg/day can be infused for 28 days and larger volumes for shorter periods. Up to three separate catheters can be inserted to allow coadministration of compounds for assessment of potential interactions. Body weight, ophthalmoscopy, blood sampling, electrocardiography, and indirect blood pressure measurement can be performed during infusion. Histopathologic common changes in all species include thrombosis, proliferation of vascular intima, and various local inflammatory changes at the infusion site in the vicinity of the catheter tip. These generally are considered to be due to physical irritation by the catheter. Secondary changes include pulmonary microemboli or thrombosis and histiocytosis in hepatic sinusoids often with erythrophago-cytosis. The main findings associated with infusion of very large volumes are reticulocytosis and increased hematopoiesis. These spontaneous findings must be distinguished from those possibly related to administration of the test material and/or vehicle.


Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Yusuke Shimoda ◽  
Naoki Nakayama ◽  
Masaaki Hokari ◽  
Takeo Abumiya ◽  
Hideo Shichinohe ◽  
...  

Background and Purpose: Although recent researches on cerebral aneurysms (CAs) have been performed with the hydrodynamic or the molecular biological technique, the mechanisms of rupture are not fully understood. The aim of this study is to assess the mechanism by a comparison between ruptured and un-ruptured CAs with histopathological and electron-microscopic analysis. Methods: We analyzed 33 CAs (24 ruptured, 9 un-ruptured) collected surgically after neck clipping. As for the ruptured CAs, we operated them within 24 hours from the onset. HE staining, Elastica Masson staining, PTAH staining, and CD68 immunohistochemical staining were performed with paraffin sections. Morphological analysis with Scanning Electron Microscopy (SEM) was performed with 6 CAs (3 ruptured, 3 un-ruptured). Results: The common histopathological finding in both ruptured and un-ruptured CAs was that the aneurysmal wall consisted mostly of thick collagen layer without normal internal elastic lamina and media. The characteristic histopathological finding in ruptured CAs was inside intramural thrombus formation with infiltration of CD68 positive cells at the rupture point. The common SEM finding in both ruptured and un-ruptured CAs was the denudation of endothelial cells and the exposure of a subendothelial amorphous or a fibrous surface. The characteristic SEM finding in ruptured CAs was the cluster formation of thick fibrin fibers with incorporation of macrophages and platelets. Conclusions: While the endothelial denudation, the disappearance of internal elastic lamina and media, and the predominance of collagen layer in the aneurysmal wall were common in both ruptured and un-ruptured CAs, inside intramural thrombus formation with inflammatory reactions was characteristic only in ruptured CAs. This result suggests that thrombo-inflammatory reactions in CAs may act as a trigger for ruptures.


1994 ◽  
Vol 267 (1) ◽  
pp. R97-R106 ◽  
Author(s):  
H. S. Huang ◽  
J. C. Longhurst

The cardiovascular effects of regional abdominal ischemia and reperfusion were studied in cats anesthetized with alpha-chloralose. In group 1 (n = 9), central venous pressure was kept constant by a servo-controller while the celiac and superior mesenteric arteries were occluded by loop snares for 10 min. In group 2 (n = 9), a constant-perfusion circuit to the celiac and superior mesenteric arteries that could divert flow to the femoral vein was used to induce abdominal ischemia. In group 3 (n = 7), venous return from the inferior vena cava was controlled, and a constant-perfusion circuit was used to induce abdominal ischemia. Abdominal ischemia significantly (P < 0.05) increased portal venous blood lactate from 4.3 +/- 0.6 to 6.0 +/- 0.6 mM in group 3. The early increases in blood pressure caused by passive volume shifts in groups 1 and 2 were abolished in group 3. The late, i.e., 10 min, response to abdominal ischemia consisted of significant (P < 0.05) increases in mean arterial pressure (29 +/- 7, 24 +/- 7, and 33 +/- 8 mmHg in groups 1, 2, and 3, respectively). Abdominal ischemia also significantly (P < 0.05) increased the first derivative of left ventricular pressure at 40 mmHg developed pressure from 4,355 +/- 377 to 4,839 +/- 407 mmHg/s in group 3. Celiac and superior mesenteric ganglionectomy abolished the late but not the early hemodynamic changes. Ganglionectomy also significantly (P < 0.05) enhanced the decrease in mean arterial pressure during reperfusion in all groups. We conclude that the pressor and contractile responses during 10 min of abdominal ischemia and the relative maintenance of blood pressure during reperfusion after ischemia are reflex in nature.


2020 ◽  
pp. 1-8
Author(s):  
Ovidiu Tirnavean ◽  
Christophe Van Bellinghen ◽  
Luc Monfort ◽  
Bruno Coulier ◽  
Michel Buche ◽  
...  

CJEM ◽  
2009 ◽  
Vol 11 (06) ◽  
pp. 558-559
Author(s):  
Truptesh H. Kothari ◽  
Shivangi Kothari ◽  
Mahima Pandey ◽  
Harshit Khara ◽  
Nishant Dhungel

A 38-year-old man with a history of polyposis syndrome diagnosed 3 years previously, with poor compliance for follow-up, presented to the emergency department with symptoms of retrosternal chest pain associated with dizziness and shortness of breath. His blood pressure was 94/43 mm Hg, his pulse was 123 beats/min and he had an oxygen saturation of 84% on room air. The patient’s initial laboratory results showed a hemoglobin of 80 g/L and blood gas with a pH of 7.23. He had a normal chest radiograph and electrocardiogram, but had an elevated troponin I at 0.12 μg/L. He was given acetylsalicylic acid for suspicion of acute coronary syndrome. On physical examination, the patient was found to have right calf tenderness. With this finding and the presenting symptoms, he underwent computed tomography angiography (CTA) of the chest. The chest CTA showed a massive saddle embolus with a filling defect completely occluding the right pulmonary artery and extending through the main pulmonary artery segment to involve the left pulmonary artery. There were also diffuse filling defects involving bilateral pulmonary segmental arteries (Fig. 1 and Fig. 2). The patient received alteplase and underwent a workup for a hypercoagulable state. His workup revealed positive anticardiolipin antibodies and factor V Leiden. The Doppler ultrasound of his lower extremities showed an extensive thrombus measuring more than 6 cm extending in the right superficial femoral vein. The patient was then referred for placement of an inferior vena cava filter.


Author(s):  
Vivek A. Wadhawa ◽  
Kartik G. Patel ◽  
Chirag P. Doshi ◽  
Jigar K. Shah ◽  
Jaydip A. Ramani ◽  
...  

Objective One of the major challenges faced in minimally invasive pediatric cardiac surgery is cannulation strategy for cardiopulmonary bypass. Central aortic cannulation through the same incision has been the usual strategy, but it has the disadvantage of cluttering of the operative field. We hereby present the results of femoral cannulation in minimally invasive pediatric cardiac surgery in terms of adequacy and safety. Methods From January 2013 to June 2016, 200 children (122 males) with mean ± SD age of 9.2 ± 4.51 years (median = 6 years, range = 3–18 years) and weight of 19.22 ± 8.49 kg (median = 15 kg, range = 8–45 kg) were operated for congenital cardiac defects through anterolateral thoracotomy. The most common diagnosis was atrial septal defect (144 patients). In all the patients, femoral artery and femoral vein were cannulated along with direct superior vena cava cannulation for institution of cardiopulmonary bypass. Results There were no deaths or any major complications related to femoral cannulation. Femoral artery cannulation provided adequate arterial inflow, whereas femoral vein with direct superior vena cava cannulation provided adequate venous return in all the patients. No patient required vacuum-assisted venous drainage. No patient required conversion to sternotomy or developed vascular, neurological complications. At discharge and at 1-year follow-up, both femoral artery and vein were patent without a significant stenosis on color Doppler ultrasonography in all the patients. At mean ± SD follow-up period of 30.63 ± 10.09 months, all the patients were doing well without any wound-related, neurological, or vascular complications. Conclusions Femoral arterial and venous cannulation is a feasible, reliable, and efficient method for institution of cardiopulmonary bypass in minimally invasive pediatric cardiac surgery.


2020 ◽  
Vol 7 ◽  
Author(s):  
Tongwei Ren ◽  
Qingrong Mo ◽  
Yuxu Wang ◽  
Hao Wang ◽  
Zuorong Nong ◽  
...  

Getah virus (GETV) has caused many outbreaks in animals in recent years. Monitoring of the virus and its related diseases is crucial to control the transmission of the virus. In the summer of 2018, we conducted routine tests on clinical samples from different pig farms in Guangxi province, South China, and isolated and characterized a GETV strain, named GX201808. Cytopathic effects were observed in BHK-21 cells inoculated with GX201808. The expression of E2 protein of GETV could be detected in virus-infected cells by indirect immunofluorescence assays. Electron microscopic analysis showed that the virus particles were spherical and ~70 nm in diameter with featured surface fibers. The multistep growth curves showed the virus propagated well in the BHK-21 cells. Molecular genetic analysis revealed that GX201808 belongs to Group 3, represented by Kochi-01-2005 isolated in Japan in 2005, and it clustered closely with the recently reported Chinese strains isolated from pigs, cattle, and foxes. A comparison of the identities of nucleotides and amino acids in the coding regions demonstrated that the GX201808 showed the highest amino acid identity (99.6%) with the HuN1 strain, a highly pathogenic isolate resulting in an outbreak of GETV infection in swine herds in Hunan province in 2017. In the present study, GETV was identified and isolated for the first time in Guangxi province of southern China, suggesting that future surveillance of this virus should be strengthened.


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