scholarly journals The Modular Organization of the Pial Arterial System in Phylogeny

1984 ◽  
Vol 4 (3) ◽  
pp. 391-396 ◽  
Author(s):  
George McHedlishvili ◽  
Nina Kuridze
Keyword(s):  
Blood Supply ◽  
Arterial System ◽  
Modular Organization ◽  
Vertebrate Species ◽  
Spatial Regulation ◽  
Pial Vessels ◽  
Gradual Development ◽  
Adequate Blood Supply ◽  
Vasomotor Activity ◽  
Cerebral Neocortex

We have investigated the pial arterial microcircles formed by the consecutive ramifications and anastomoses of minute pial vessels on the surface of the cerebral neocortex in various vertebrate species, representatives of various levels of phylogenic development. We found that the pial arterial microcircles became gradually more complex in the following order: hen < rabbit < cat < dog < monkey. The gradual development of microcircles involves various features in these species: (a) They become formed predominantly of smaller pial arterial branches whose vasomotor activity is much higher as compared with that of the larger ones; (b) each circle occupies a smaller area, and hence the number of circles per surface of neocortex increases; (c) the density of arterial branches feeding the circles increases despite the smaller size of the latter; (d) the number of offshooting precortical and radial arteries penetrating the cortex increases; (e) the areas of neocortex fed by individual radial arteries get gradually smaller. Thus, the development of the pial arterial bed contributes more and more toward precise spatial regulation of an adequate blood supply to increasingly smaller areas of neocortical tissue as we rise toward higher levels in phylogeny.

scholarly journals Species functional traits and abundance as drivers of multiplex ecological networks: first empirical quantification of inter-layer edge weights

2020 ◽  
Vol 287 (1939) ◽  
pp. 20202127
Author(s):  
S. Hervías-Parejo ◽  
C. Tur ◽  
R. Heleno ◽  
M. Nogales ◽  
S. Timóteo ◽  
...  
Keyword(s):  
Species Traits ◽  
Abundant Species ◽  
Modular Organization ◽  
Vertebrate Species ◽  
Multilayer Network ◽  
Functional Roles ◽  
Different Types ◽  
Seed Dispersers ◽  
Natural Communities

Many vertebrate species act as both plant pollinators and seed-dispersers, thus interconnecting these processes, particularly on islands. Ecological multilayer networks are a powerful tool to explore interdependencies between processes; however, quantifying the links between species engaging in different types of interactions (i.e. inter-layer edges) remains a great challenge. Here, we empirically measured inter-layer edge weights by quantifying the role of individually marked birds as both pollinators and seed-dispersers of Galápagos plant species over an entire year. Although most species (80%) engaged in both functions, we show that only a small proportion of individuals actually linked the two processes, highlighting the need to further consider intra-specific variability in individuals' functional roles. Furthermore, we found a high variation among species in linking both processes, i.e. some species contribute more than others to the modular organization of the multilayer network. Small and abundant species are particularly important for the cohesion of pollinator seed-dispersal networks, demonstrating the interplay between species traits and neutral processes structuring natural communities.

scholarly journals The importance of pial blood supply to the development of peritumoral brain edema in meningiomas

1997 ◽  
Vol 2 (4) ◽  
pp. E6 ◽  
Author(s):  
Michael Bitzer ◽  
Lars Wöckel ◽  
Andreas R. Luft ◽  
Ajay K. Wakhloo ◽  
Dirk Petersen ◽  
...  
Keyword(s):  
Brain Edema ◽  
Blood Supply ◽  
Tumor Size ◽  
Tumor Volume ◽  
Volume Ratio ◽  
Total Tumor Volume ◽  
Pial Vessels ◽  
Peritumoral Brain Edema ◽  
Tumor Region ◽  
The Mean

The authors studied the pial and dural blood supplies in 74 intracranial meningiomas and quantified their associated peritumoral brain edema (PTBE). The extent and localization of pial blush in relation to the total tumor volume were determined angiographically. The amount of edema and tumor size were calculated using computerized tomography. The edema-tumor volume ratio was defined as Edema Index (EI). There were 49 meningiomas with PTBE; of those tumors, 46 were supplied by pial vessels, and three were supplied exclusively by dural vessels. Tumors without PTBE showed no pial blush. The mean EI in meningiomas with pial blush was significantly larger (EI = 3.0) than in meningiomas without pial supply (EI = 1.1; p < 0.0001). Meningiomas in which 10% of the whole tumor volume was supplied by pial vessels had only a small mean EI of 2.2, whereas tumors with pial blood supply greater than or equal to 20% had a mean EI of 3.3 (p < 0.026). In 69.9% of cases with pial blood supply, major portions of the edema were located adjacent to the tumor region supplied by pial vessels. Edema index differences among tumors of different subgroups, as defined by size or histology, were significantly related to the pial supply in each subset. Thus, pial blood supply may be causative for the development of PTBE in meningiomas.

scholarly journals Mechanisms Involved in Apice Closure of Pulpless Teeth – Literature Review

2021 ◽  
Vol 15 (1) ◽  
pp. 127-136
Author(s):  
Alexandrino Pereira dos Santos Neto ◽  
Sandra Maria Alves Sayão Maia ◽  
Jair Carneiro Leão ◽  
Iliana Lins Quidute ◽  
Carolina dos Santos Guimarães ◽  
...  
Keyword(s):  
Stem Cells ◽  
Literature Review ◽  
Blood Supply ◽  
Root Formation ◽  
Adequate Blood Supply ◽  
Revascularization Therapy ◽  
Oral Stem Cells ◽  
Pulp Revascularization ◽  
Professional Intervention

Background: Unfinished root formation has always offered challenges in endodontics due to technical difficulties and weakened teeth resistance during the lifetime of an individual. Pulp revascularization therapy appeared as a solution for apical closure and root maturation. The existence of oral stem cells involved in the process associated with traditional resident cells requires adequate blood supply given by induced controlled injury deliberately accomplished into the periapical zone. Objective: The aim of this work was to research, through literature review, the main mechanisms involved in the process of apical closure through the technique of pulp revascularization. Conclusion: Apice closure in pulpless teeth seems to happen as a result of professional intervention and biological activity. The success rate depends on the role of traditional local immune cells and stem cells associated with adequate blood supply to finish root formation.

The importance of pial blood supply to the development of peritumoral brain edema in meningiomas

1997 ◽  
Vol 87 (3) ◽  
pp. 368-373 ◽  
Author(s):  
Michael Bitzer ◽  
Lars Wöckel ◽  
Andreas R. Luft ◽  
Ajay K. Wakhloo ◽  
Dirk Petersen ◽  
...  
Keyword(s):  
Brain Edema ◽  
Blood Supply ◽  
Tumor Volume ◽  
Volume Ratio ◽  
Content Type ◽  
Total Tumor Volume ◽  
Pial Vessels ◽  
Peritumoral Brain Edema ◽  
Tumor Region ◽  
The Mean

✓ In a retrospective analysis, the authors studied the pial and dural blood supplies in 74 intracranial meningiomas and quantified their associated peritumoral brain edema (PTBE). The extent and localization of pial blush in relation to the total tumor volume were determined angiographically. The amount of edema and tumor size were calculated using computerized tomography. The edema—tumor volume ratio was defined as Edema Index (EI). There were 49 meningiomas with PTBE; of those tumors, 46 were supplied by pial vessels, and three were supplied exclusively by dural vessels. Tumors without PTBE showed no pial blush. The mean EI in meningiomas with pial blush was significantly larger (EI = 3) than in meningiomas without pial supply (EI = 1.1; p < 0.0001). Meningiomas with a smaller pial supply than dural supply had a significantly smaller mean EI than tumors with a pial supply equal to or greater than the dural supply (EI = 2.9 vs. EI = 3.7; p < 0.015). In 69.9% of cases with pial blood supply, major portions of the edema were located adjacent to the tumor region supplied by pial vessels. Edema index differences among tumors of different subgroups, as defined by size or histology, were significantly related to the pial supply in each subset. Thus, pial blood supply may be associated with the development of PTBE in meningiomas.

Nerve Grafts: the Importance of an Adequate Blood Supply

1945 ◽  
Vol 2 (1) ◽  
pp. 49-71 ◽  
Author(s):  
I. M. Tarlov ◽  
J. A. Epstein
Keyword(s):  
Blood Supply ◽  
Nerve Grafts ◽  
Adequate Blood Supply

scholarly journals KNOWLEDGE AND AWARENESS ABOUT ANGINA PECTORIS AMONG PHARMACY STUDENTS

2014 ◽  
Vol 4 ◽  
pp. 81
Author(s):  
Humera Khatoon ◽  
Keyword(s):  
Myocardial Infarction ◽  
Angina Pectoris ◽  
Blood Supply ◽  
Heart Muscle ◽  
Heart Attack ◽  
Pharmacy Students ◽  
Warning Sign ◽  
Chest Discomfort ◽  
Adequate Blood Supply ◽  
Disease Sign

Objective of this study is to determine the awareness among student of Pharm D with Angina Pectoris (AP) regarding the disease, sign & symptoms and treatment.The term Angina Pectoris is applied to varying forms of transient chest discomfort that are attributable to insufficient myocardial oxygen. The classic description of angina is a crushing pain that radiates through the chest and sometimes down the arm, neck, teeth /jaw or into the back, which is usually aggravated by exertion or stress. Angina is a warning sign that the heart muscle is not getting adequate blood supply and specially oxygen and it may lead to myocardial infarction or a heart attack

Extracranial-Intracranial Arterial Bypass to a Single Branch of the Middle Cerebral Artery in the Management of a Traumatic Aneurysm

Neurosurgery ◽  
1979 ◽  
Vol 4 (4) ◽  
pp. 334-337 ◽  
Author(s):  
Robert F. Spetzler ◽  
Michael P. Owen
Keyword(s):  
Middle Cerebral Artery ◽  
Blood Supply ◽  
Cerebral Artery ◽  
Superficial Temporal Artery ◽  
Temporal Artery ◽  
Low Flow ◽  
Traumatic Aneurysm ◽  
Flow Demand ◽  
Adequate Blood Supply ◽  
Single Branch

Abstract This case required the clipping of a single branch of the middle cerebral artery for the treatment of a traumatic aneurysm. To ensure an adequate blood supply distal to the occlusion, we anastomosed the superficial temporal artery to that branch of the middle cerebral artery (MCA) distal to the aneurysm. Despite the low flow required to irrigate only one branch of the MCA, the anastomosis remained patent. This case demonstrates the feasibility of performing small vessel anastomoses in spite of low flow demand.

scholarly journals Traumatic Arteriovenous Fistula of the Scalp in the Left Temporoparietal Region with Intra- and Extracranial Blood Supply

2016 ◽  
Vol 2016 ◽  
pp. 1-4 ◽  
Author(s):  
Feng Zheng ◽  
Herbert Augustus Pitts ◽  
Roland Goldbrunner ◽  
Boris Krischek
Keyword(s):  
Arteriovenous Fistula ◽  
Blood Supply ◽  
Superficial Temporal Artery ◽  
Temporal Artery ◽  
High Flow ◽  
Arterial System ◽  
Low Flow ◽  
Radiological Features ◽  
Feeding Vessels ◽  
Capillary Bed

Traumatic AVF of the scalp is a rare abnormal vascular disease. It is defined as a communication between the high flow arterial system and the low flow venous network, which directly connects the arterial feeding vessels of the scalp and the draining veins without an intervening capillary bed. The superficial temporal artery (STA) was involved in 90% of the cases, and 71% of the patients only had one dominant feeding STA. Here, we report the case of a rare large traumatic arteriovenous fistula (AVF) of the scalp that is fed by intra- and extracranial blood supply. The clinical and radiological features are presented, and the possible pathogenesis and surgical technique are discussed.

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