China
Africa
Explore chapters and articles related to this topic
The Lymphatic/Immune System and Its Disorders
Published in Walter F. Stanaszek, Mary J. Stanaszek, Robert J. Holt, Steven Strauss, Understanding Medical Terms, 2020
Walter F. Stanaszek, Mary J. Stanaszek, Robert J. Holt, Steven Strauss
The initial lymphatics are extremely permeable. Lymphatic capillary walls consist of a single layer of flat endothelial cells attached to the surrounding tissues with anchoring ligaments, which are thin filaments extending between surrounding cells and holding the lymphatic capillary in place. The endothelial cells slightly overlap, so the edge of one cell forms a flap over the adjacent cell, serving as a one-way valve into the initial lymphatic and increasing the vessel's porosity. The high permeability of the initial lymphatics allows interstitial fluid, particles, and protein molecules to flow into the vessel. The fluid is essentially overflow from the interstitial spaces and has the same constituents. It is known as lymph from the Latin word lympha, meaning water. Along the course of the lymphatics, particularly where several smaller vessels join to form a larger one, the lymph passes through lymph nodes (also called lymphaden), organs whose function is to filter particles out of the lymph before it empties into the veins.
Application of Microcirculation Research to Clinical Disease
Published in John H. Barker, Gary L. Anderson, Michael D. Menger, Clinically Applied Microcirculation Research, 2019
Bengt Fagrell, Alfred Bollinger
Visualization of lymphatic capillaries by FITC-dextran 150’000 is a prerequisite for insertion of glass micropipettes by a micromanipulator and measurement of intralymphatic pressure by servo-nulling systems.14 In primary lymphedema, lymphatic capillary pressure is increased as has been published recently.15 Mean lymphatic capillary pressure and standard deviations were 7.9 ± 3.4 mmHg in control subjects and 15.0 ± 5.1 mmHg in patients with primary lymphedema manifesting after puberty (p < 0.001). Site of measurement was the forefoot in recumbent position.15 Microlymphatic hypertension seems to be an important feature for disease pathophysiology.
Dermal Lymph and Lymphatics
Published in Waldemar L. Olszewski, Lymph Stasis: Pathophysiology, Diagnosis and Treatment, 2019
The functional characteristics of the lymphatics which are effective not only for the human skin lymphatics but also for the human and animal lymphatics of all other organs are: The lymphatic capillary possesses open endothelial junction and scanty basal lamina with an increased permeability to the macromolecules and the cells passing to the lymph node. This makes it perform lysosomal digestion or clearing of the causative organism in cases of infection, of toxic foreign body, and of damaged tissue and also makes it undertake a prompt immunological response by transporting the antigen, antibody, immune complex, and immunologically active cell to the lymph node.The lymphatic capillary has a thin endothelial cell, loose or open endothelial junction, scanty basal lamina, and no pericyte and anchoring filament attached to the endothelial cell. This makes it possible for the capillary to dilate remarkably to compensate edema state of any extent, for example, in the case of urticaria.The initial lymphatic shows positive enzyme histochemical staining of the capillary for adenylate and guanylate cyclase. This may be associated with the more active transendothelial fluid intake.A safety valve function of the lymphatic system is its potent ability to compensate any pathological condition which is not observed in the physiologic state. For instance, after skin operation or transplantation the fluid leaks out of the thrombosed small blood vasculature or cut blood capillary. The lymphatic can absorb this extra fluid which should have been taken in by the intact or cut venules. Foeldi called it “safety valve function”.35
The role of MPL and imiquimod adjuvants in enhancement of immune response and protection in BALB/c mice immunized with soluble Leishmania antigen (SLA) encapsulated in nanoliposome
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Tara Emami, Seyed Mahdi Rezayat, Ali Khamesipour, Rasool Madani, Gholamreza Habibi, Mansure Hojatizade, Mahmoud Reza Jaafari
Synthetic phospholipids affect the charge of liposomes, according to the head groups [48]. Because of the presence of neutral PC (DSPC) and negative PG(DSPG) head groups of phospholipids, the liposome charge has shown a negative charge, which could be influenced by adjuvants and antigen charges (Figure 1(c)). The average size of liposomal formulations was around 95 nm. Lymphatic capillary uptake depends on size, charge and hydrophobicity [49]. The size of the vehicle is important for lymphatic drainage and uptaking through endocytosis by dendritic cells [50]. Particle sizes between 10 and 100 nm removed by lymphatic vessels as a choice, particles larger than 100 nm remain at the site of injection as a reservoir, and particles smaller than 10 nm removed by blood vessels [49]. Zeta potential of liposomal formulations was between ∼−16 mV (lip/MPL/buffer) and ∼−37 mV (liposome/buffer), which implies the impact of antigen and adjuvants charges on zeta potential of liposome formulations (Figure 1(c)).
Improved lymphatic targeting: effect and mechanism of synthetic borneol on lymph node uptake of 7-ethyl-10-hydroxycamptothecin nanoliposomes following subcutaneous administration
Published in Drug Delivery, 2018
Tiantian Ye, Yue Wu, Lei Shang, Xueqing Deng, Shujun Wang
Impact of S-BO on injection site and lymph node irritation was histopathologically investigated via H&E staining. Blank feet and lymph nodes were served as negative controls without administration. The injection site results of histopathological examination in the three borneol group in the concentrations of 1, 2 and 5 mg/mL were shown in Figure 5(A). The lymphatic wall and vein wall were complete and didn’t have any significant expansion. The endothelial cells without swelling and necrosis were clear. There is no obvious inflammation around the lymphatic capillary and capillaries. Muscle structures were normal and the texture was clear. There was no bleeding and edema phenomenon in the interstitial. Thus morphological observation showed three borneol groups in the concentrations of 1, 2 and 5 mg/mL didn’t have obvious irritation for the interstitial tissue. As shown in Figure 5(B), there was no necrosis occurred in the lymph nodes of three administration groups. However, comparing with blank lymph nodes, threes S-BO groups had relative hyperplasia. The number of lymphoid follicles increased, and the germinal center was significantly enlarged and proliferated. There were a large number of various transformed lymphocytes with large nuclei. Therefore, it can be discriminated that there was a reactive hyperplasia in the lymph nodes of the administration group. And the degree of hyperplasia increased with the increase of S-BO concentration. The lymph nodes in the 1 and 2 mg/mL S-BO group only had slight hyperplasia. But the lymph nodes in the 5 mg/mL S-BO group appeared severe hyperplasia, which may be that 5 mg/mL S-BO didn’t not further increase lymph node uptake compared with 2 mg/mL S-BO. Thus, irritability of 2 mg/mL S-BO for lymph nodes could be acceptable.
Modelling uptake and transport of therapeutic agents through the lymphatic system
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2022
T. D. Jayathungage Don, V. Suresh, J. E. Cater, R. J. Clarke
The computational mesh was created using the Octree method in ANSYS ICEM CFD, and consists of unstructured tetrahedral volumes and triangular surface mesh elements. The lymphatic capillary wall was modeled as a one-cell thick prismatic layer covering the lymphatic capillary surface. This layer was defined as a porous region, with specified permeability.