Substantial evidence from epidemiological, pathological, and clinical reports suggests that vascular factors are critical in the pathogenesis of Alzheimer's disease (AD), and changes in blood flow ...are currently the most reliable indicators of the disease. We previously reported that older APP23 transgenic (tg) mice have significant blood flow alterations correlated with structural modifications of blood vessels. For the present study, our objective was to analyze the age-dependent morphological and architectural changes of the cerebral vasculature of APP23 tg mice. To visualize the 3D arrangement of the entire brain vasculature, we used vascular corrosion casts. Already at young ages, when typically parenchymal amyloid plaques are not yet present, APP23 tg mice had significant alterations, particularly of the microvasculature, often accompanied by small deposits attached to the vessels. In older animals, vasculature abruptly ended at amyloid plaques, resulting in holes. Often, small deposits were sitting near or at the end of truncated vessels. Between such holes, the surrounding vascular array appeared more dense and showed features typical for angiogenesis. We propose that small amyloid aggregates associated with the microvasculature lead to morphological and architectural alterations of the vasculature, resulting in altered local blood flow. The characteristic early onset of vascular alterations suggests that imaging blood flow and/or vasculature architecture could be used as a tool for early diagnosis of the disease and to monitor therapies.
Many studies of cardiovascular function require a realistic representation of vascular geometry. Corrosion casting has been used to acquire such geometries for many decades. However, the fidelity ...with which this method reproduces vascular anatomy has not been completely determined. Here we report on the non‐linear shrinkage characteristics and exothermic properties of Batson's #17, a widely used casting resin, in model systems and in aortas of rats and rabbits. The setting process was captured using high‐resolution photography. Shrinkage ranged from 3.4 ± 1.5% of the diameter in 1 ml plastic syringes (inner diameter 4.8 mm) to 19.6 ± 5.6% in the aorta of rats (diameter 1.5–2.6 mm). In addition, aortic curvature and branching angles changed during setting. These effects should be determined and corrected in studies of vascular geometry where high accuracy is required.
Vascular corrosion casting is frequently used to characterize arterial geometry. Here, we quantify the non‐linear shrinkage of the casting resin that can occur during such procedures.
The intricate (micro)vascular architecture of the liver has not yet been fully unravelled. Although current models are often idealized simplifications of the complex anatomical reality, correct ...morphological information is instrumental for scientific and clinical purposes. Previously, both vascular corrosion casting (VCC) and immunohistochemistry (IHC) have been separately used to study the hepatic vasculature. Nevertheless, these techniques still face a number of challenges such as dual casting in VCC and limited imaging depths for IHC. We have optimized both techniques and combined their complementary strengths to develop a framework for multilevel reconstruction of the hepatic circulation in the rat. The VCC and micro‐CT scanning protocol was improved by enabling dual casting, optimizing the contrast agent concentration, and adjusting the viscosity of the resin (PU4ii). IHC was improved with an optimized clearing technique (CUBIC) that extended the imaging depth for confocal microscopy more than five‐fold. Using in‐house developed software (DeLiver), the vascular network – in both VCC and IHC datasets – was automatically segmented and/or morphologically analysed. Our methodological framework allows 3D reconstruction and quantification of the hepatic circulation, ranging from the major blood vessels down to the intertwined and interconnected sinusoids. We believe that the presented framework will have value beyond studies of the liver, and will facilitate a better understanding of various parenchymal organs in general, in physiological and pathological circumstances.
The collateral network concept: A reassessment of the anatomy of spinal cord perfusion Etz, Christian D., MD, PhD; Kari, Fabian A., MD; Mueller, Christoph S., MD ...
Journal of thoracic and cardiovascular surgery/The Journal of thoracic and cardiovascular surgery/The journal of thoracic and cardiovascular surgery,
04/2011, Letnik:
141, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Objective Prevention of paraplegia after repair of thoracoabdominal aortic aneurysm requires understanding the anatomy and physiology of the spinal cord blood supply. Recent laboratory studies and ...clinical observations suggest that a robust collateral network must exist to explain preservation of spinal cord perfusion when segmental vessels are interrupted. An anatomic study was undertaken. Methods Twelve juvenile Yorkshire pigs underwent aortic cannulation and infusion of a low-viscosity acrylic resin at physiologic pressures. After curing of the resin and digestion of all organic tissue, the anatomy of the blood supply to the spinal cord was studied grossly and with light and electron microscopy. Results All vascular structures at least 8 μm in diameter were preserved. Thoracic and lumbar segmental arteries give rise not only to the anterior spinal artery but to an extensive paraspinous network feeding the erector spinae, iliopsoas, and associated muscles. The anterior spinal artery, mean diameter 134 ± 20 μm, is connected at multiple points to repetitive circular epidural arteries with mean diameters of 150 ± 26 μm. The capacity of the paraspinous muscular network is 25-fold the capacity of the circular epidural arterial network and anterior spinal artery combined. Extensive arterial collateralization is apparent between the intraspinal and paraspinous networks, and within each network. Only 75% of all segmental arteries provide direct anterior spinal artery–supplying branches. Conclusions The anterior spinal artery is only one component of an extensive paraspinous and intraspinal collateral vascular network. This network provides an anatomic explanation of the physiological resiliency of spinal cord perfusion when segmental arteries are sacrificed during thoracoabdominal aortic aneurysm repair.
The aim of this study was to visualize and describe the vascular architecture of the vaginal and supravaginal parts of the human uterine cervix. Uteri collected at autopsy (n = 42) were perfused via ...the afferent vessels with fixative followed by Mercox resin. After polymerization of the resin, corrosion was performed. The obtained vascular casts of the cervix, visualizing all vessels including capillaries, were examined using scanning electron microscopy. Both in the vaginal and supravaginal parts of the cervix, four distinct vascular zones were distinguished – the outer zone containing large arteries and veins, the arteriole and venule zone, the endocervical mucosal capillaries zone and the pericanalar zone containing small veins and capillaries. In the pericanalar zone ran small veins, responsible for draining the mucosal capillaries. Both in the muscular layer, as well as in the pericanalar zone, arterioles and venules passed close to each other, often adjoining. This study introduces the idea of two systems responsible for draining blood from the mucosal capillaries. It is also the first to suggest the possible existence of a countercurrent transport between adjoining veins and arteries.
Extracellular matrix (ECM) scaffolds, obtained through detergent-based decellularization of native kidneys, represent the most promising platform for investigations aiming at manufacturing kidneys ...for transplant purposes. We previously showed that decellularization of the human kidney yields renal ECM scaffolds (hrECMs) that maintain their basic molecular components, are cytocompatible, stimulate angiogenesis, and show an intact innate vasculature. However, evidence that the decellularization preserves glomerular morphometric characteristics, physiological parameters (pressures and resistances of the vasculature bed), and biological properties of the renal ECM, including retention of important growth factors (GFs), is still missing.
To address these issues, we studied the morphometry and resilience of hrECMs' native vasculature with resin casting at electronic microscopy and pulse-wave measurements, respectively. Moreover, we determined the fate of 40 critical GFs post decellularization with a glass chip-based multiplex enzyme-linked immunosorbent assay array and in vitro immunofluorescence.
Our method preserves the 3-dimensional conformation of the native glomerulus. Resin casting and pulse-wave measurements, showed that hrECMs preserves the microvascular morphology and morphometry, and physiological function. Moreover, GFs including vascular endothelial growth factor and its receptors are retained within the matrices.
Our results indicate that discarded human kidneys are a suitable source of renal scaffolds because they maintain a well-preserved structure and function of the vasculature, as well as GFs that are fundamental to achieve a satisfying recellularization of the scaffold in vivo due to their angiogenic properties.
Nintedanib, a tyrosine kinase inhibitor approved for the treatment of idiopathic pulmonary fibrosis, has anti-fibrotic, anti-inflammatory, and anti-angiogenic activity. We explored the impact of ...nintedanib on microvascular architecture in a pulmonary fibrosis model. Lung fibrosis was induced in C57Bl/6 mice by intratracheal bleomycin (0.5 mg/kg). Nintedanib was started after the onset of lung pathology (50 mg/kg twice daily, orally). Micro-computed tomography was performed via volumetric assessment. Static lung compliance and forced vital capacity were determined by invasive measurements. Mice were subjected to bronchoalveolar lavage and histologic analyses, or perfused with a casting resin. Microvascular corrosion casts were imaged by scanning electron microscopy and synchrotron radiation tomographic microscopy, and quantified morphometrically. Bleomycin administration resulted in a significant increase in higher-density areas in the lungs detected by micro-computed tomography, which was significantly attenuated by nintedanib. Nintedanib significantly reduced lung fibrosis and vascular proliferation, normalized the distorted microvascular architecture, and was associated with a trend toward improvement in lung function and inflammation. Nintedanib resulted in a prominent improvement in pulmonary microvascular architecture, which outperformed the effect of nintedanib on lung function and inflammation. These findings uncover a potential new mode of action of nintedanib that may contribute to its efficacy in idiopathic pulmonary fibrosis.
Detailed knowledge of the anatomy of human placenta vessels is clinically essential and requires the use of many different anatomical and histological techniques. One of the interesting methods of ...visualising vessels is the corrosion technique. It enables spatial visualisation of the vascular network of the analysed organ. The authors present a developed, own method of preparing the corrosive preparations from human placenta. They underline the advantages and disadvantages of this technique. They describe solutions aimed at reducing the costs of the process. They show that corrosion technology enables relatively fast and inexpensive visualisation of arterial and venous vessels of the human placenta.
In human medicine, magnetic resonance cholangiopancreatography (MRCP) is a valuable diagnostic tool for hepatobiliary and pancreatic diseases. In veterinary medicine, however, data evaluating the ...diagnostic value of MRCP are limited. The primary objectives of this prospective, observational, analytical investigation were to assess whether MRCP reliably visualizes the biliary tract and pancreatic ducts in cats without and with related disorders, and whether MRCP images and measurements of the ducts agree with those of fluoroscopic retrograde cholangiopancreatography (FRCP), corrosion casting and histopathology. A secondary objective was to provide MRCP reference diameters for bile ducts, GB, and pancreatic ducts. Donated bodies of 12 euthanized adult cats underwent MRCP, FRCP, and autopsy with corrosion casting of the biliary tract and pancreatic ducts using vinyl polysiloxane. Diameters of the biliary ducts, gallbladder (GB), and pancreatic ducts were measured using MRCP, FRCP, corrosion casts and histopathologic slides. There was an agreement between MRCP and FRCP in measuring diameters of the GB body, GB neck, cystic duct, and common bile duct (CBD) at papilla. Strong positive correlations existed between MRCP and corrosion casting for measuring GB body and neck, cystic duct, and CBD at the extrahepatic ducts’ junction. In contrast to the reference methods, post‐mortem MRCP did not visualize right and left extrahepatic ducts, and pancreatic ducts in most cats. Based on this study, MRCP with 1.5 Tesla can be regarded as a contributory method to improve the assessment of feline biliary tract and pancreatic ducts when their diameter is >1 mm.
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