Vessel Occlusions in Plants: Morphological, Functional and Evolutionary Aspects

IAWA Journal ◽  
1990 ◽  
Vol 11 (4) ◽  
pp. 393-399 ◽  
Author(s):  
Karel J. M. Bonsen ◽  
Ladislav J. Kučera
Keyword(s):  
Functional Significance ◽  
Vessel Wall ◽  
Plant Evolution ◽  
Anatomical Feature ◽  
Vessel Occlusion ◽  
Aperture Diameter ◽  
Primitive Angiosperms ◽  
Evolutionary Hypothesis ◽  
Evolutionary Aspects

The minimum pit aperture diameter of a vessel-parenchyma pit pair was found as the decisive wood anatomical feature for vessel occlusion by either tyloses or gums. Based on this observation, as well as on considerations and established knowledge about the functional significance of vessel occlusions, an evolutionary hypothesis is presented. In order to withstand microorganisms and embolisms, plants are able to occlude their vessels with tyloses or gums. The most primitive Angiosperms show tylosis formation. With the decreasing pit sizes in the vessel wall during plant evolution, gum formation was developed, whereas the increasing vessel sizes led in some plants to renewed tylosis formation.

A case report: Early findings of distal vessel occlusion pre and post-thrombolysis using three-dimensional black blood vessel wall imaging in acute stroke.

2021 ◽  
Vol 3 (1) ◽  
pp. 156-158
Author(s):  
Mohd Fandi Al Khafiz Kamis ◽  
Chia Peck Kee ◽  
Mohd Naim Mohd Yaakob ◽  
Ezamin Abdul Rahim ◽  
Ahmad Sobri Muda ◽  
...  
Keyword(s):  
Blood Vessel ◽  
Acute Stroke ◽  
Vessel Wall ◽  
Three Dimensional ◽  
Vessel Wall Imaging ◽  
Black Blood ◽  
Blood Vessel Wall ◽  
Vessel Occlusion ◽  
Distal Vessel ◽  
Wall Imaging

Distal vessel occlusion of an eloquent area in acute stroke may lead to significant disability. Advances in magnetic resonance imaging enable direct visualization of thrombus within the small distal intracranial artery. The evolution of medical devices for mechanical thrombectomy has allowed the smaller distal vessels to be treated. It may change the approach to how we treat distal vessel occlusion in the future. This case highlights the value of three-dimensional black blood vessel wall imaging assessing distal vessel occlusion and respond towards reperfusion therapy. 

scholarly journals The Many Faces of Intracranial Arterial Dissections

2010 ◽  
Vol 16 (2) ◽  
pp. 151-160 ◽  
Author(s):  
T. Krings ◽  
I-S. Choi
Keyword(s):  
Vessel Wall ◽  
Combined Treatment ◽  
Treatment Protocol ◽  
Treatment Strategies ◽  
Intramural Hematoma ◽  
Mass Effect ◽  
Vasa Vasorum ◽  
Parent Vessel ◽  
Vessel Occlusion ◽  
Parent Vessel Occlusion

Intracranial arterial dissecting diseases are rare and challenging diseases with a high associated morbidity and mortality. Their common pathomechanic origin is related to blood entering the vessel wall via an endothelial and intimal tear. Depending on the fate of the thus established intramural hematoma, different symptoms may ensue including mass effect, subarachnoid hemorrhage or ischemia. If the mural hematoma ruptures all vascular layers of the intradural artery, a subarachnoid hemorrhagic will occur. If the intramural hematoma reopens distally into the parent vessel on the other hand, ischemic embolic events may happen following intramural clot formation. If the mural hematoma does neither open itself into the parent vessel nor into the subarachnoid space, the vessel wall may dilate leading to occlusion of perforator branches and local ischemia. Organization of the mural hematoma may result in a chronic dissecting process which may eventually lead to formation of a “giant partially thrombosed” aneurysm with thrombus of varying ages within the vessel wall, ingrowth of vasa vasorum and recurrent dissections with subsequent growth of the aneurysm from the periphery. Treatment strategies of these diseases should take the underlying pathomechanism into consideration and include, depending on the presentation medical treatment, parent vessel occlusion, flow reversal or diversion, surgical options or a combined treatment protocol.

Interventional stroke treatment – Is it also safe for arteries? Looking at thrombectomy wall damage through clot histology

2020 ◽  
pp. 159101992097667
Author(s):  
Frank Donnerstag ◽  
Friedrich Götz ◽  
Mete Dadak ◽  
Peter Raab ◽  
Enrico Calvino Iglesias ◽  
...  
Keyword(s):  
Vessel Wall ◽  
Morphological Evidence ◽  
Time Interval ◽  
Vessel Occlusion ◽  
Aspiration Thrombectomy ◽  
Stroke Treatment ◽  
Vessel Injury ◽  
Formalin Fixed Paraffin ◽  
Formalin Fixed Paraffin Embedded ◽  
Wall Injury

Background and purpose The aim of this study was to investigate whether morphological evidence of intracranial vascular injury can be found in the occluding thrombi of patients with ischemic stroke. Methods From 2015 until 2018 specimens of thrombi from patients with large vessel occlusion treated either by stent-assisted aspiration thrombectomy (TE) or by aspiration thrombectomy were prospectively collected. Thrombus specimens were formalin-fixed, paraffin-embedded and stained. Architectural features, presence of parts of vessel wall or atheromatous material, organisation of the thrombi, technique and number of thrombectomy manoeuvers were evaluated. Results Thrombus specimens from 302 patients were analyzed. 238 (80%) patients were treated with stent-assisted aspiration TE and 64 (20%) patients with aspiration TE only. 286 (95%) had fresh thrombi, 14 (4.6%) showed initial/complete thrombus organisation and multi-staged thrombi were found in 2 (<1%) patients. In 8 patients (2.6%) we found atypical thrombus content after a time interval longer 6 hours after onset and final thrombectomy manoeuvre: 4 with atheromatous material and 4 with parts of a vessel wall. In 1 patient with parts of vessel wall angiographically a dissection was detected. No parts of the vessel wall were found after sole aspiration thrombectomy. Conclusions The overall risk of arterial vessel wall injury aspiration thrombectomy was low in our study. Aspiration thrombectomy and the procedure related with a retrieving device together with an ischemia time longer than 6 hours may increase the risk of vessel injury through the thrombectomy procedure. Further investigations are necessary to elucidate the influence of the mentioned aspects.

Vessel Wall Injury and Arterial Thrombosis Induced by a Photochemical Reaction

1995 ◽  
Vol 73 (05) ◽  
pp. 868-872 ◽  
Author(s):  
Abby R Saniabadi ◽  
Kazuo Umemura ◽  
Nobuteru Matsumoto ◽  
Sadayuki Sakuma ◽  
Mitsuyoshi Nakashima
Keyword(s):  
Electron Microscopy ◽  
Rose Bengal ◽  
Arterial Thrombosis ◽  
Photochemical Reaction ◽  
Vessel Wall ◽  
Cell Injury ◽  
Green Light ◽  
Vessel Occlusion ◽  
Vessel Injury ◽  
Wall Injury

SummaryArterial thrombosis may be initiated in an experimental animal by a photochemical reaction between transmural green light and i.v. administered Rose Bengal, a photosensitizer dye. In this study, scanning electron microscopy has been used to reveal the nature of vessel injury and the cellular composition of the photochemically induced thrombus. A 5 mm segment of the guinea pig femoral artery was occluded by a thrombus about 10 min after irradiation with green light in the presence of systemically administered Rose Bengal. Electron microscopy revealed that following photochemical reaction, endothelial cells first contract and, with further irradiation, become detached from the vessel wall, with their cell membrane being destroyed at the irradiated site where an occlusive platelet-rich thrombus was formed. Endothelial cell injury and vessel occlusion could be completely inhibited by the aminothiol, DL-cysteine administered i.v. 1 min after Rose Bengal. The mechanism of endothelial injury in this model appears to be by singlet molecular oxygen, 1O2 formed by energy transfer from the photo-excited dye to O2.

scholarly journals Why Weightlifters Grunt: A Classroom Exercise That Introduces Students to Evolution

2019 ◽  
Vol 81 (7) ◽  
pp. 474-478
Author(s):  
H. Charles Romesburg
Keyword(s):  
College Students ◽  
Cultural Evolution ◽  
Biological Evolution ◽  
Plant Evolution ◽  
Evolutionary Hypothesis ◽  
Classroom Exercise

A classroom exercise is described in which college students take part in creating and supporting an evolutionary hypothesis that explains effort grunting. The exercise holds their interest throughout and readies them to understand hypotheses of animal and plant evolution. It informs them about the dependence of cultural evolution upon biological evolution, and it connects widely to curricula.

Functional significance of preserved color patterns of mollusks from the Gosport Sand (Eocene) of Alabama

1988 ◽  
Vol 62 (01) ◽  
pp. 83-87 ◽  
Author(s):  
Patricia H. Kelley ◽  
Charles T. Swann
Keyword(s):  
Functional Morphology ◽  
Functional Significance ◽  
Intraspecific Variability ◽  
Color Pattern ◽  
Color Patterns ◽  
Historical Factors ◽  
Life Mode ◽  
Molluscan Fauna ◽  
Excellent Preservation ◽  
Architectural Constraints

The excellent preservation of the molluscan fauna from the Gosport Sand (Eocene) at Little Stave Creek, Alabama, has made it possible to describe the preserved color patterns of 15 species. In this study the functional significance of these color patterns is tested in the context of the current adaptationist controversy. The pigment of the color pattern is thought to be a result of metabolic waste disposal. Therefore, the presence of the pigment is functional, although the patterns formed by the pigment may or may not have been adaptive. In this investigation the criteria proposed by Seilacher (1972) for testing the functionality of color patterns were applied to the Gosport fauna and the results compared with life mode as interpreted from knowledge of extant relatives and functional morphology. Using Seilacher's criteria of little ontogenetic and intraspecific variability, the color patterns appear to have been functional. However, the functional morphology studies indicate an infaunal life mode which would preclude functional color patterns. Particular color patterns are instead interpreted to be the result of historical factors, such as multiple adaptive peaks or random fixation of alleles, or of architectural constraints including possibly pleiotropy or allometry. The low variability of color patterns, which was noted within species and genera, suggests that color patterns may also serve a useful taxonomic purpose.

Complex Vesicles, Microtubules, and Cytoplasmic Filaments in the Endothelial Cells of Normal Dog Aorta

1968 ◽  
Vol 26 ◽  
pp. 172-173
Author(s):  
C. N. Sun ◽  
J. J. Ghidoni
Keyword(s):  
Electron Microscopy ◽  
Endothelial Cells ◽  
Cross Sections ◽  
Functional Significance ◽  
Tubular Structures ◽  
Aldehyde Fixation ◽  
Cytoplasmic Filaments

Endothelial cells in longitudinal and cross sections of aortas from 3 randomly selected “normal” mongrel dogs were studied by electron microscopy. Segments of aorta were distended with cold cacodylate buffered 5% glutaraldehyde for 10 minutes prior to being cut into small, well oriented tissue blocks. After an additional 1-1/2 hour period in glutaraldehyde, the tissue blocks were well rinsed in buffer and post-fixed in OsO4. After dehydration they were embedded in a mixture of Maraglas, D.E.R. 732, and DDSA.Aldehyde fixation preserves the filamentous and tubular structures (300 Å and less) for adequate demonstration and study. The functional significance of filaments and microtubules has been recently discussed by Buckley and Porter; the precise roles of these cytoplasmic components remains problematic. Endothelial cells in canine aortas contained an abundance of both types of structures.

The molecular mechanism of mechanotransduction in vascular homeostasis and disease

2020 ◽  
Vol 134 (17) ◽  
pp. 2399-2418
Author(s):  
Yoshito Yamashiro ◽  
Hiromi Yanagisawa
Keyword(s):  
Shear Stress ◽  
Blood Vessels ◽  
Vessel Wall ◽  
Vascular Diseases ◽  
Cell Interactions ◽  
Aortic Aneurysms ◽  
Cyclic Stretch ◽  
Mechanical Stimuli ◽  
Vascular Homeostasis ◽  
Matrix Cell

Abstract Blood vessels are constantly exposed to mechanical stimuli such as shear stress due to flow and pulsatile stretch. The extracellular matrix maintains the structural integrity of the vessel wall and coordinates with a dynamic mechanical environment to provide cues to initiate intracellular signaling pathway(s), thereby changing cellular behaviors and functions. However, the precise role of matrix–cell interactions involved in mechanotransduction during vascular homeostasis and disease development remains to be fully determined. In this review, we introduce hemodynamics forces in blood vessels and the initial sensors of mechanical stimuli, including cell–cell junctional molecules, G-protein-coupled receptors (GPCRs), multiple ion channels, and a variety of small GTPases. We then highlight the molecular mechanotransduction events in the vessel wall triggered by laminar shear stress (LSS) and disturbed shear stress (DSS) on vascular endothelial cells (ECs), and cyclic stretch in ECs and vascular smooth muscle cells (SMCs)—both of which activate several key transcription factors. Finally, we provide a recent overview of matrix–cell interactions and mechanotransduction centered on fibronectin in ECs and thrombospondin-1 in SMCs. The results of this review suggest that abnormal mechanical cues or altered responses to mechanical stimuli in EC and SMCs serve as the molecular basis of vascular diseases such as atherosclerosis, hypertension and aortic aneurysms. Collecting evidence and advancing knowledge on the mechanotransduction in the vessel wall can lead to a new direction of therapeutic interventions for vascular diseases.

Sign in / Sign up

Export Citation Format

Share Document