Isolated Lymphatic Vessel Perfusion System Design for Independently Controlling Hoop Stress and Shear Stress

2012 ◽  
Author(s):  
Jeffrey A. Kornuta ◽  
J. Brandon Dixon
Keyword(s):  
Shear Stress ◽  
Particulate Matter ◽  
Chronic Disease ◽  
Lymphatic Vessel ◽  
Hoop Stress ◽  
Lymphatic System ◽  
The Body ◽  
Tissue Homeostasis ◽  
Perfusion System ◽  
Clinical Problems

Most tissues in the body are supported by the lymphatic system for a variety of functions, including the regulation of fluid balance, the removal of particulate matter from the interstitium, as well as the transport of fat from the intestine to the blood, among others. Lymphedema, a chronic disease characterized by an inability of the lymphatics to maintain tissue homeostasis and estimated to affect over 130 million people worldwide, can result in serious clinical problems for which there are very few beneficial cures or therapies [1]. However, despite the importance of lymphatics and the prevalence of lymphatic disease, very little is known about the particular mechanisms through which the lymphatics fulfill its primary functions.

An In Vitro Model to Quantify the Effects of Fluid Shear Stress on Lymphatic Pump Function

2011 ◽  
Author(s):  
Jeffrey A. Kornuta ◽  
Arina Korneva ◽  
J. Brandon Dixon
Keyword(s):  
Fluid Balance ◽  
In Vitro Model ◽  
Lymphatic System ◽  
Fluid Shear Stress ◽  
Mechanical Load ◽  
Tissue Homeostasis ◽  
Fluid Shear ◽  
Vitro Model ◽  
Clinical Problems

Nearly all tissues are supported by the lymphatic system for a variety of functions, including the regulation of fluid balance, the removal of particulate matter from the interstitium, as well as the transport of fat from the intestine to the blood, among others. Despite these important functions, very little is known about the particular mechanisms through which the lymphatics fulfill these roles. Lymphedema, a chronic disease characterized by an inability of the lymphatics to maintain tissue homeostasis and estimated to affect over 130 million people worldwide, can result in serious clinical problems for which there are very few beneficial cures or therapies [1]. While fluid stagnation is the primary clinical manifestation of the disease, severe lymphedema is often correlated with tissue remodeling and the gross accumulation of lipid [1]. Given these symptoms, one must consider the breakdown in the lymphatic response to mechanical load (i.e. fluid balance) in order to understand the progression of the disease.

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.

Scanning electron microscopy of freeze-fractured prescapular lymph node of caprine

1984 ◽  
Vol 42 ◽  
pp. 244-245
Author(s):  
O. Faroon ◽  
F. Al-Bagdadi ◽  
T. G. Snider ◽  
C. Titkemeyer
Keyword(s):  
Lymph Node ◽  
Lymph Nodes ◽  
Lymphatic System ◽  
Three Dimensional ◽  
Meat Products ◽  
The Body ◽  
Morphological Data ◽  
The World ◽  
Cellular Constituent ◽  
Scanning Electron

The lymphatic system is very important in the immunological activities of the body. Clinicians confirm the diagnosis of infectious diseases by palpating the involved cutaneous lymph node for changes in size, heat, and consistency. Clinical pathologists diagnose systemic diseases through biopsies of superficial lymph nodes. In many parts of the world the goat is considered as an important source of milk and meat products.The lymphatic system has been studied extensively. These studies lack precise information on the natural morphology of the lymph nodes and their vascular and cellular constituent. This is due to using improper technique for such studies. A few studies used the SEM, conducted by cutting the lymph node with a blade. The morphological data collected by this method are artificial and do not reflect the normal three dimensional surface of the examined area of the lymph node. SEM has been used to study the lymph vessels and lymph nodes of different animals. No information on the cutaneous lymph nodes of the goat has ever been collected using the scanning electron microscope.

EFFECT OF DIFFERENT DOSES OF PREDNISOLONE AND ADRENOCORTICOTROPHIC HORMONE (ACTH) ON LYMPHATIC LUNG CLEARANCE AND ON EXPERIMENTAL SILICOSIS

1970 ◽  
Vol 63 (2) ◽  
pp. 325-337
Author(s):  
Carl-Johan Göthe
Keyword(s):  
Lymph Nodes ◽  
Lymphatic System ◽  
The Body ◽  
Lung Weight ◽  
Lung Clearance ◽  
Dust Transport ◽  
Fine Particulate ◽  
Quartz Dust ◽  
Different Doses ◽  
Stimulation Of

ABSTRACT The effect of three doses of prednisolone and ACTH respectively on the weight of the body, the lungs and the hilar lymph nodes was studied on rats killed one month after the intratracheal (i.t.) injection of 50 mg of fine-particulate quartz. The prednisolone was administered via the drinking water, and the ACTH was injected intraperitoneally during the period between the i.t. injection of quartz dust and the killing of the animals. Prednisolone causes the rats to become cachectic and reduces the weight of the hilar lymph nodes. It also retards the transport of quartz dust from the lungs via the lymphatics. All these effects increase with increasing doses of prednisolone. However, its effect on the lung weight is insignificant. ACTH does not affect the body weight, but retards the weight increase of the lungs and the hilar lymph nodes. These effects increase with increasing doses of ACTH, and seem to be connected with an ability of ACTH to promote the clearance of quartz dust from the lungs and hilar lymph nodes. The method used, however, does not make it possible to differentiate quantitatively between any ACTH effects on the bronchogenie and lymphatic lung-clearance mechanisms. Available data, however, indicate that the stimulation of the dust transport from the lungs and hilar lymph nodes is, at least to some extent, related to the lymphatic system.

scholarly journals Finite Element Analysis of Composite Repair for Damaged Steel Pipeline

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 301
Author(s):  
Jiaqi Chen ◽  
Hao Wang ◽  
Milad Salemi ◽  
Perumalsamy N. Balaguru
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Hoop Stress ◽  
Pipe Wall ◽  
Von Mises Stress ◽  
Repair System ◽  
Composite Repair ◽  
Steel Pipeline ◽  
Von Mises ◽  
Infill Material

Carbon fiber reinforced polymer (CFRP) matrix composite overwrap repair systems have been introduced and accepted as an alternative repair system for steel pipeline. This paper aimed to evaluate the mechanical behavior of damaged steel pipeline with CFRP repair using finite element (FE) analysis. Two different repair strategies, namely wrap repair and patch repair, were considered. The mechanical responses of pipeline with the composite repair system under the maximum allowable operating pressure (MAOP) was analyzed using the validated FE models. The design parameters of the CFRP repair system were analyzed, including patch/wrap size and thickness, defect size, interface bonding, and the material properties of the infill material. The results show that both the stress in the pipe wall and CFRP could be reduced by using a thicker CFRP. With the increase in patch size in the hoop direction, the maximum von Mises stress in the pipe wall generally decreased as the maximum hoop stress in the CFRP increased. The reinforcement of the CFRP repair system could be enhanced by using infill material with a higher elastic modulus. The CFRP patch tended to cause higher interface shear stress than CFRP wrap, but the shear stress could be reduced by using a thicker CFRP. Compared with the fully bonded condition, the frictional interface causes a decrease in hoop stress in the CFRP but an increase in von Mises stress in the steel. The study results indicate the feasibility of composite repair for damaged steel pipeline.

scholarly journals MERTK-Mediated LC3-Associated Phagocytosis (LAP) of Apoptotic Substrates in Blood-Separated Tissues: Retina, Testis, Ovarian Follicles

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1443
Author(s):  
Marina G. Yefimova ◽  
Celia Ravel ◽  
Antoine D. Rolland ◽  
Nicolas Bourmeyster ◽  
Bernard Jégou
Keyword(s):  
Sertoli Cells ◽  
Tyrosine Kinases ◽  
Acute Inflammation ◽  
The Body ◽  
Tissue Homeostasis ◽  
Ovarian Granulosa Cells ◽  
Males And Females ◽  
Retinal Pigmented Epithelial Cells ◽  
Related Proteins ◽  
Efficient Elimination

Timely and efficient elimination of apoptotic substrates, continuously produced during one’s lifespan, is a vital need for all tissues of the body. This task is achieved by cells endowed with phagocytic activity. In blood-separated tissues such as the retina, the testis and the ovaries, the resident cells of epithelial origin as retinal pigmented epithelial cells (RPE), testis Sertoli cells and ovarian granulosa cells (GC) provide phagocytic cleaning of apoptotic cells and cell membranes. Disruption of this process leads to functional ablation as blindness in the retina and compromised fertility in males and females. To ensure the efficient elimination of apoptotic substrates, RPE, Sertoli cells and GC combine various mechanisms allowing maintenance of tissue homeostasis and avoiding acute inflammation, tissue disorganization and functional ablation. In tight cooperation with other phagocytosis receptors, MERTK—a member of the TAM family of receptor tyrosine kinases (RTK)—plays a pivotal role in apoptotic substrate cleaning from the retina, the testis and the ovaries through unconventional autophagy-assisted phagocytosis process LAP (LC3-associated phagocytosis). In this review, we focus on the interplay between TAM RTKs, autophagy-related proteins, LAP, and Toll-like receptors (TLR), as well as the regulatory mechanisms allowing these components to sustain tissue homeostasis and prevent functional ablation of the retina, the testis and the ovaries.

scholarly journals Physiopathology of Spine Metastasis

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Giulio Maccauro ◽  
Maria Silvia Spinelli ◽  
Sigismondo Mauro ◽  
Carlo Perisano ◽  
Calogero Graci ◽  
...  
Keyword(s):  
Growth Factors ◽  
Bone Metastasis ◽  
Lymphatic System ◽  
Spinal Metastasis ◽  
Bone Destruction ◽  
The Body ◽  
Vicious Cycle ◽  
Patients With Cancer ◽  
Local Tumour ◽  
Neurological Injuries

The metastasis is the spread of cancer from one part of the body to another. Two-thirds of patients with cancer will develop bone metastasis. Breast, prostate and lung cancer are responsible for more than 80% of cases of metastatic bone disease. The spine is the most common site of bone metastasis. A spinal metastasis may cause pain, instability and neurological injuries. The diffusion through Batson venous system is the principal process of spinal metastasis, but the dissemination is possible also through arterial and lymphatic system or by contiguity. Once cancer cells have invaded the bone, they produce growth factors that stimulate osteoblastic or osteolytic activity resulting in bone remodeling with release of other growth factors that lead to a vicious cycle of bone destruction and growth of local tumour.

Indirect Lymphoscintigraphy in Patients with Limb Oedema

1986 ◽  
Vol 1 (3) ◽  
pp. 211-215 ◽  
Author(s):  
A. Pecking ◽  
R. Cluzan ◽  
J.P. Desprez-Curely ◽  
P. Guerin
Keyword(s):  
Lower Limb ◽  
Lymphatic System ◽  
Invasive Procedures ◽  
Non Invasive ◽  
Morphological Findings ◽  
Invasive Method ◽  
Varicose Disease ◽  
Post Traumatic ◽  
Web Space ◽  
Clinical Problems

One thousand four hundred and fifty-five lymphoscintigraphies using a radio-labelled colloid were performed as an objective test for the diagnosis and the survey of lower limb oedemas. It is a non-invasive method involving only a subdermic bipedal injection into the first web space of each foot. Our results demonstrate that in chronic swollen legs due to venous causes occuring from post-thrombotic syndrome or varicose disease the lymphatic system can be insufficient (14.9% and 19.8% of these cases). Abnormal results are found in 91.3% of clinically primary lymphoedemas. In unilateral primary lymphoedemas the clinically healthy controlateral limb can be insufficient (25%). In post-traumatic lower limb oedemas the lymphatic flow remains normal while perilymphatic extravasation and dermal filling are always to be found at the trauma site. The lymphoscintigraphy is a simple, physiological and reliable test. The morphological findings based upon 1455 examinations allow us to think that this method may resolve the clinical problems without recourse to more invasive procedures. We can expect that in a few years this morphological study will be completed with a functional lymphatic test.

scholarly journals Expected ages in the patients of chronic diseases

2016 ◽  
Vol 10 (4) ◽  
Author(s):  
Intesaruk Rashid Khan ◽  
Ahmed Imran Siddiqui ◽  
Wafa Aftab
Keyword(s):  
Heart Failure ◽  
Renal Failure ◽  
Retrospective Study ◽  
Chronic Disease ◽  
Chronic Renal Failure ◽  
Hepatic Cirrhosis ◽  
Disease Process ◽  
Chronic Illnesses ◽  
The Body ◽  
Medical Wards

This retrospective study was conducted to find out the expected ages in the patients of hepatic cirrhosis, chronic renal failure and heart failure. This study thus covers most of the patients of out medical wards presenting with chronic illnesses. On comparison of these expected ages it is also found that the expected age in all these three groups is not much different. So, the disease process or the mechanism of the chronic disease in the body may be different, but somehow the final out come is not much different in terms of life span.

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