scholarly journals Graph Theory for Modeling and Analysis of the Human Lymphatic System

Mathematics ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 2236
Author(s):  
Rostislav Savinkov ◽  
Dmitry Grebennikov ◽  
Darya Puchkova ◽  
Valery Chereshnev ◽  
Igor Sazonov ◽  
...  
Keyword(s):  
Graph Theory ◽  
Lymphatic System ◽  
Lymphatic Vessels ◽  
Oriented Graph ◽  
Mass Conservation ◽  
Graph Models ◽  
Modeling And Analysis ◽  
Anatomical Data ◽  
Graph Energy ◽  
Lymphatic Network

The human lymphatic system (HLS) is a complex network of lymphatic organs linked through the lymphatic vessels. We present a graph theory-based approach to model and analyze the human lymphatic network. Two different methods of building a graph are considered: the method using anatomical data directly and the method based on a system of rules derived from structural analysis of HLS. A simple anatomical data-based graph is converted to an oriented graph by quantifying the steady-state fluid balance in the lymphatic network with the use of the Poiseuille equation in vessels and the mass conservation at vessel junctions. A computational algorithm for the generation of the rule-based random graph is developed and implemented. Some fundamental characteristics of the two types of HLS graph models are analyzed using different metrics such as graph energy, clustering, robustness, etc.

Initial Steps Toward Development of a Lumped-Parameter Model of the Lymphatic Network

2013 ◽  
Author(s):  
Samira Jamalian ◽  
Christopher D. Bertram ◽  
James E. Moore
Keyword(s):  
Blood Circulation ◽  
Lymphatic Vessel ◽  
Lymphatic System ◽  
Lymphatic Vessels ◽  
The Body ◽  
Lumped Parameter Model ◽  
Circulation System ◽  
Blood Circulation System ◽  
Lumped Parameter ◽  
Lymphatic Network

One of the primary functions of the lymphatic system is maintaining fluid and protein balance in the body. The system holds this balance by collecting about four liters of fluid every day from the interstitial space and returning it back to the subclavian vein. In contrast to the blood circulation system that relies on the heart for pumping, there is no central pump in the lymphatic system. Thus, the transport of viscous fluid against gravity and pressure difference occurs by recruiting extrinsic and intrinsic pumping mechanisms. Extrinsic pumping is the transport of lymph due to the movements outside the lymphatic vessel such as the pulse in blood vessels, whereas the intrinsic pumping is transport of lymph by contraction of lymphatic muscle cells embedded in the walls of lymphatic vessels. Similar to the veins, the bi-leaflet valves throughout the lymphatic network prevent backflow. Lymphatic valves are biased open and allow for small amounts of back flow before they completely shut.

scholarly journals Optimal postnodal lymphatic network structure that maximizes active propulsion of lymph

2009 ◽  
Vol 296 (2) ◽  
pp. H303-H309 ◽  
Author(s):  
Arun M. Venugopal ◽  
Christopher M. Quick ◽  
Glen A. Laine ◽  
Randolph H. Stewart
Keyword(s):  
Critical Parameter ◽  
Interstitial Fluid ◽  
Lymphatic System ◽  
Lymphatic Vessels ◽  
Lymph Flow ◽  
Optimal Structure ◽  
Structural Parameter ◽  
Time Varying ◽  
Lymphatic Network ◽  
Algebraic Formula

The lymphatic system acts to return lower-pressured interstitial fluid to the higher-pressured veins by a complex network of vessels spanning more than three orders of magnitude in size. Lymphatic vessels consist of lymphangions, segments of vessels between two unidirectional valves, which contain smooth muscle that cyclically pumps lymph against a pressure gradient. Whereas the principles governing the optimal structure of arterial networks have been identified by variations of Murray's law, the principles governing the optimal structure of the lymphatic system have yet to be elucidated, although lymph flow can be identified as a critical parameter. The reason for this deficiency can be identified. Until recently, there has been no algebraic formula, such as Poiseuille's law, that relates lymphangion structure to its function. We therefore employed a recently developed mathematical model, based on the time-varying elastance model conventionally used to describe ventricular function, that was validated by data collected from postnodal bovine mesenteric lymphangions. From this lymphangion model, we developed a model to determine the structure of a lymphatic network that optimizes lymph flow. The model predicted that there is a lymphangion length that optimizes lymph flow and that symmetrical networks optimize lymph flow when the lymphangions downstream of a bifurcation are 1.26 times the length of the lymphangions immediately upstream. Measured lymphangion lengths (1.14 ± 0.5 cm, n = 74) were consistent with the range of predicted optimal lengths (0.1–2.1 cm). This modeling approach was possible, because it allowed a structural parameter, such as length, to be treated as a variable.

Infrared fluorescence lymphography in experimental and clinical practice

2018 ◽  
Vol 17 (2) ◽  
pp. 84-91 ◽  
Author(s):  
G. V. Papayan ◽  
A. L. Akopov ◽  
P. A. Antonyan ◽  
A. A. Ilin ◽  
N. N. Petrishchev
Keyword(s):  
Lymph Nodes ◽  
Near Infrared ◽  
Lymphatic System ◽  
Lymphatic Vessels ◽  
Diagnostic System ◽  
Biological Tissues ◽  
Peritumoral Injection ◽  
Intradermal Administration ◽  
Nir Fluorescence ◽  
Real Time Visualization

Introduction. Near infrared (NIR) fluorescent diagnostics is promising due to a deeper penetration into biological tissues. Material and methods. In experiments on rabbits and in clinical studies evaluation the lymphatic system with the use of the instrument complex FLUM-808 was analysed. Results. For visualization of the lymphatic vessels of the skin, the intradermal administration of ICG, dissolved in 20 % albumin in the order of 0.02 mg/ml, is optimal. Peritumoral injection of ICG allows visualizing sentinel lymph nodes in patients with lung cancer. Conclusions. The developed NIR fluorescence diagnostic system FLUM-808 allows to real time visualization of lymphatic vessels and lymph nodes.

scholarly journals Acute small intestinal inflammation results in persistent lymphatic alterations

2018 ◽  
Vol 314 (3) ◽  
pp. G408-G417 ◽  
Author(s):  
Sonia Rehal ◽  
Matthew Stephens ◽  
Simon Roizes ◽  
Shan Liao ◽  
Pierre-Yves von der Weid
Keyword(s):  
Dendritic Cell ◽  
Lymphatic System ◽  
Intestinal Inflammation ◽  
Critical Role ◽  
Lymphatic Vessels ◽  
Lymphoid Tissues ◽  
Functional Changes ◽  
Increased Risk ◽  
Small Intestinal ◽  
Acute Ileitis

Inflammatory bowel disease (IBD) has a complex pathophysiology with limited treatments. Structural and functional changes in the intestinal lymphatic system have been associated with the disease, with increased risk of IBD occurrence linked to a history of acute intestinal injury. To examine the potential role of the lymphatic system in inflammation recurrence, we evaluated morphological and functional changes in mouse mucosal and mesenteric lymphatic vessels, and within the mesenteric lymph nodes during acute ileitis caused by a 7-day treatment with dextran sodium sulfate (DSS). We monitored whether the changes persisted during a 14-day recovery period and determined their potential consequences on dendritic cell (DC) trafficking between the mucosa and lymphoid tissues. DSS administration was associated with marked lymphatic abnormalities and dysfunctions exemplified by lymphangiectasia and lymphangiogenesis in the ileal mucosa and mesentery, increased mesenteric lymphatic vessel leakage, and lymphadenopathy. Lymphangiogenesis and lymphadenopathy were still evident after recovery from intestinal inflammation and correlated with higher numbers of DCs in mucosal and lymphatic tissues. Specifically, a deficit in CD103+ DCs observed during acute DSS in the lamina propria was reversed and further enhanced during recovery. We concluded that an acute intestinal insult caused alterations of the mesenteric lymphatic system, including lymphangiogenesis, which persisted after resolution of inflammation. These morphological and functional changes could compromise DC function and movement, increasing susceptibility to further gastrointestinal disease. Elucidation of the changes in mesenteric and intestinal lymphatic function should offer key insights for new therapeutic strategies in gastrointestinal disorders such as IBD. NEW & NOTEWORTHY Lymphatic integrity plays a critical role in small intestinal homeostasis. Acute intestinal insult in a mouse model of acute ileitis causes morphological and functional changes in mesenteric and intestinal lymphatic vessels. While some of the changes significantly regressed during inflammation resolution, others persisted, including lymphangiogenesis and altered dendritic cell function and movement, potentially increasing susceptibility to the recurrence of gastrointestinal inflammation.

Lymphangiogenesis in development and disease

2007 ◽  
Vol 98 (08) ◽  
pp. 304-310 ◽  
Author(s):  
Ruediger Liersch ◽  
Michael Detmar
Keyword(s):  
Lymph Nodes ◽  
Cancer Metastasis ◽  
Lymphatic System ◽  
Vascular System ◽  
Malignant Tumors ◽  
Inflammatory Diseases ◽  
Transplant Rejection ◽  
Lymphatic Vessels ◽  
Lipid Uptake ◽  
Molecular Control

SummaryThe lymphatic vascular system plays an important role in the maintenance of fluid homeostasis, in the afferent immune response, in the intestinal lipid uptake and in the metastatic spread of malignant cells. The recent discovery of specific markers and growth factors for lymphatic endothelium and the establishment of genetic mouse models with impairment of lymphatic function have provided novel insights into the molecular control of the lymphatic system in physiology and in embryonic development. They have also identified molecular pathways whose mutational inactivation leads to human diseases associated with lymphedema. Moreover, the lymphatic system plays a major role in chronic inflammatory diseases and in transplant rejection. Importantly, malignant tumors can directly promote lymphangiogenesis within the primary tumor and in draining lymph nodes, leading to enhanced cancer metastasis to lymph nodes and beyond. Based upon these findings, novel therapeutic strategies are currently being developed that aim at inhibiting or promoting the formation and function of lymphatic vessels in disease.

scholarly journals Review on the Lymphatic Vessels in the Dental Pulp

Biology ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1257
Author(s):  
Kamila Wiśniewska ◽  
Zbigniew Rybak ◽  
Maria Szymonowicz ◽  
Piotr Kuropka ◽  
Maciej Dobrzyński
Keyword(s):  
Dental Pulp ◽  
Lymphatic System ◽  
Light And Electron Microscopy ◽  
Fluid Pressure ◽  
Lymphatic Vessels ◽  
Main Role ◽  
Reaction Products ◽  
Dental Tissues ◽  
Optical Electron ◽  
Antigen Antibody

Despite many studies, opinions on the lymphatic system of the teeth are still incompatible. Studies using light and electron microscopy and directly using methods such as a radioisotope (radionuclide) scan and interstitial fluid pressure measurement reported incomplete results. Immunohistochemistry (IHC) plays the main role in investigating presence of the lymphatic system in dental tissues. This method uses labeled antibodies against antigens typical of lymphatic vessels. The use of appropriate staining enables the detection of antigen-antibody reaction products using a light (optical), electron or fluorescence microscope. However, these studies do not show the system of vessels, their histologic structure under physiological conditions and inflammation as well as the lymphangiogenesis process in the dental pulp. Unfortunately, there is a lack of studies associating the presence of lymphatic vessels in the dental pulp with local lymphatic nodes or large vessels outside the tooth. In the scientific and research environment, the evaluation of the lymphatic system of the teeth is problematic because it is quite difficult to clearly distinguish lymphatic vessels from small blood vessels. Despite many indications of the presence of lymphatic vessels in the pulp chamber, this problem remains open and needs further research.

scholarly journals Cerebral Edema Formation After Stroke: Emphasis on Blood–Brain Barrier and the Lymphatic Drainage System of the Brain

2021 ◽  
Vol 15 ◽  
Author(s):  
Sichao Chen ◽  
Linqian Shao ◽  
Li Ma
Keyword(s):  
Blood Brain Barrier ◽  
Cerebral Edema ◽  
Lymphatic System ◽  
Vasogenic Edema ◽  
Lymphatic Vessels ◽  
Drainage System ◽  
Brain Barrier ◽  
Edema Formation ◽  
Blood Brain ◽  
The Brain

Brain edema is a severe stroke complication that is associated with prolonged hospitalization and poor outcomes. Swollen tissues in the brain compromise cerebral perfusion and may also result in transtentorial herniation. As a physical and biochemical barrier between the peripheral circulation and the central nervous system (CNS), the blood–brain barrier (BBB) plays a vital role in maintaining the stable microenvironment of the CNS. Under pathological conditions, such as ischemic stroke, the dysfunction of the BBB results in increased paracellular permeability, directly contributing to the extravasation of blood components into the brain and causing cerebral vasogenic edema. Recent studies have led to the discovery of the glymphatic system and meningeal lymphatic vessels, which provide a channel for cerebrospinal fluid (CSF) to enter the brain and drain to nearby lymph nodes and communicate with the peripheral immune system, modulating immune surveillance and brain responses. A deeper understanding of the function of the cerebral lymphatic system calls into question the known mechanisms of cerebral edema after stroke. In this review, we first discuss how BBB disruption after stroke can cause or contribute to cerebral edema from the perspective of molecular and cellular pathophysiology. Finally, we discuss how the cerebral lymphatic system participates in the formation of cerebral edema after stroke and summarize the pathophysiological process of cerebral edema formation after stroke from the two directions of the BBB and cerebral lymphatic system.

scholarly journals Late developing cardiac lymphatic vasculature supports adult zebrafish heart function and regeneration

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Michael RM Harrison ◽  
Xidi Feng ◽  
Guqin Mo ◽  
Antonio Aguayo ◽  
Jessi Villafuerte ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Lymphatic System ◽  
Vascular System ◽  
Heart Function ◽  
Lymphatic Vessels ◽  
Adult Zebrafish ◽  
Heart Patients ◽  
Scar Size ◽  
Lymphatic Vasculature ◽  
Zebrafish Heart

The cardiac lymphatic vascular system and its potentially critical functions in heart patients have been largely underappreciated, in part due to a lack of experimentally accessible systems. We here demonstrate that cardiac lymphatic vessels develop in young adult zebrafish, using coronary arteries to guide their expansion down the ventricle. Mechanistically, we show that in cxcr4a mutants with defective coronary artery development, cardiac lymphatic vessels fail to expand onto the ventricle. In regenerating adult zebrafish hearts the lymphatic vasculature undergoes extensive lymphangiogenesis in response to a cryoinjury. A significant defect in reducing the scar size after cryoinjury is observed in zebrafish with impaired Vegfc/Vegfr3 signaling that fail to develop intact cardiac lymphatic vessels. These results suggest that the cardiac lymphatic system can influence the regenerative potential of the myocardium.

Bond Graph Modeling and Analysis of HEV System Based on Ravigneaux Planetary Mechanism

2013 ◽  
Vol 724-725 ◽  
pp. 1402-1408
Author(s):  
Li He Xi ◽  
Hong Wei Chen ◽  
Xin Zhang
Keyword(s):  
Bond Graph ◽  
Structural Form ◽  
Graph Models ◽  
Modeling And Analysis ◽  
Electric System ◽  
Operating Modes ◽  
Graph Modeling ◽  
Time Requirements ◽  
Bond Graph Modeling ◽  
Planetary Mechanism

The bond graph method is used to analyse and model dynamics of hybrid electric system based on Ravigneaux Planetary Mechanism. Bond graph models are built in different structural form, general equations of torque and speed are derived, and operating modes achieved in different structural form are in consideration. At the same time, requirements of control system in different operating modes are illustrated and analysed, which help lay the foundations for modeling and simulation of HEV system based on Ravigneaux Planetary Mechanism.

scholarly journals LCZ696, an Angiotensin Receptor-Neprilysin Inhibitor, Improves Cardiac Hypertrophy and Fibrosis and Cardiac Lymphatic Remodeling in Transverse Aortic Constriction Model Mice

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Qing Ge ◽  
Li Zhao ◽  
Chen Liu ◽  
Xiaoming Ren ◽  
Yi-hui Yu ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Protein Expression ◽  
Lymphatic System ◽  
Lymphatic Vessels ◽  
Mouse Heart ◽  
Transverse Aortic Constriction ◽  
Aortic Constriction ◽  
Expression Levels ◽  
Factor C ◽  
Proinflammatory Factors

Cardiac hypertrophy and ventricular remodeling following heart failure are important causes of high mortality in heart disease patients. The cardiac lymphatic system has been associated with limited research, but it plays an important role in the improvement of myocardial edema and the promotion of fluid balance. LCZ696 is a novel combination of angiotensin and neprilysin inhibitors. Here, we studied the role played by LCZ696 during transverse aortic constriction (TAC) induced cardiac hypertrophy and changes in the lymphatic system. Mice undergoing aortic coarctation were constructed to represent a cardiac hypertrophy model and then divided into random groups that either received treatment with LCZ696 (60 mg/kg/d) or no treatment. Cardiac ultrasonography was used to detect cardiac function, and hematoxylin and eosin (H&E) and Masson staining were used to detect myocardial hypertrophy and fibrosis. The proinflammatory factors interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-α (TNF-α) were detected in the blood and heart tissues of mice. The protein expression levels of lymphatic-specific markers, such as vascular endothelial growth factor C (VEGF-C), VEGF receptor 3 (VEGFR3), and lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1) were detected in mouse heart tissues. We also examined the colocalization of lymphatic vessels and macrophages by immunofluorescence. The results showed that LCZ696 significantly improved heart dysfunction, cardiac hypertrophy, and fibrosis and inhibited the expression of proinflammatory factors IL-6, IL-1β, and TNF-α in the circulating blood and heart tissues of mice. LCZ696 also decreased the protein expression levels of VEGF-C, VEGFR3, and LYVE-1 in mouse heart tissues, ameliorated the transport load of lymphatic vessels to macrophages, and improved the remodeling of the lymphatic system in the hypertrophic cardiomyopathy model induced by TAC.

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