The Experts below are selected from a list of 129 Experts worldwide ranked by ideXlab platform
A Bollinger - One of the best experts on this subject based on the ideXlab platform.
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effect of postural changes on human Lymphatic Capillary pressure of the skin
The Journal of Physiology, 1996Co-Authors: U K Franzeck, M Fischer, U Costanzo, I Herrig, A BollingerAbstract:1. The influence of postural changes on cutaneous Lymphatic Capillary pressure and venous pressure was measured at the dorsum of the foot in twelve healthy volunteers. Measurements were performed in the supine and sitting positions. 2. Lymphatic skin capillaries were visualized by fluorescence microlymphography with fluorescein isothiocyanate (FITC)-Dextran 150000. Subsequently a Lymphatic Capillary was punctured with a glass micropipette and pressure was measured using the servo-nulling technique. Lymphatic Capillary pressure, venous pressure, heart and respiration rates were recorded simultaneously. 3. Mean Lymphatic Capillary pressure was significantly higher (P = 0.0096) in the sitting (9.9 +/- 3.0 mmHg) than in the supine (3.9 +/- 4.2 mmHg) position. There was no significant difference (P = 0.09) between Lymphatic Capillary pressure and venous pressure (6.8 +/- 3.4 mmHg) in the supine position. During sitting mean Lymphatic Capillary pressure was significantly lower (P = 0.0022) than mean venous pressure (53.3 +/- 4.1 mmHg). The smaller increase in Lymphatic Capillary pressure may be caused by the discontinuous fluid column in the Lymphatic system and enhanced orthostatic contractile activity of Lymphatic collectors and precollectors. Spontaneous low frequency pressure fluctuations occurred in 89% of recordings during sitting, which was significantly (P = 0.02) higher than in the supine position (54%). 4. The present results support the suggestion of enhanced intrinsic contractile activity of lymph precollectors and collectors in the dependent position. This mechanism is primarily responsible for the propulsion of lymph from the periphery to the thoracic duct during quiet sitting, when extrinsic pumping by the calf muscles is not active.
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Flow velocity of single Lymphatic capillaries in human skin.
The American journal of physiology, 1996Co-Authors: M Fischer, U K Franzeck, U Costanzo, I Herrig, M Schiesser, U. Hoffmann, A BollingerAbstract:The purpose of this study was to investigate the previously unknown flow velocity in single Lymphatic capillaries of humans in the supine position. Fifteen healthy subjects (10 women and 5 men; mean age 35.8 +/- 13.1 yr) were studied. Ten microliters of fluorescein isothiocyanate-dextran (150,000 mol wt) were injected into the subepidermal layer of the foot dorsum. The filling of the microLymphatics from the resulting depot was visualized by fluorescence video microscopy and stored on videotape. Flow velocity in the microLymphatics was determined on the video screen by direct measurement of the advancement of dyed lymph during a given time. The following median velocities were obtained: 0.51 mm/s (0.27 and 0.61 mm/s for lower and upper quartiles, respectively) for velocity during initial network filling and 9.7 microns/s (6.9 and 14.2 microns/s for lower and upper quartiles, respectively) for resting velocity at the end of the filling period. Mean Lymphatic Capillary diameter was 54.8 +/- 8.2 microns, and mean network extension was 8.3 +/- 3.2 mm. The high filling velocities are probably due to increased interstitial pressure and volume caused by dye microinjection, whereas the values measured during the end of network filling seem to approach resting flow velocities.
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fluctuation of skin Lymphatic Capillary pressure in controls and in patients with primary lymphedema
Journal of Vascular Research, 1994Co-Authors: J Dorfflermelly, U K Franzeck, I Herrig, M Schiesser, A BollingerAbstract:The microLymphatic pressure was monitored by using the servo-nulling technique at the forefoot skin in 24 healthy volunteers (number of capillaries studied: 97) and in 27 patients with primary lymphedema (Capillary number: 67). The Lymphatic capillaries were stained by fluorescence microlymphography with fluorescein isothiocyanate-dextran 150 and cannulated using glass needles with a diameter between 7 and 9 µm. The Lymphatic Capillary hypertension described recently in primary lymphedema was confirmed in this series (mean pressure of controls 6.7 ± 3.8 and, of patients 12.8 ± 5.9 mm Hg; p
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Lymphatic Capillary pressure in patients with primary lymphedema
Microvascular Research, 1993Co-Authors: Beatrice R Zauggvesti, U K Franzeck, J Dorfflermelly, Michael Spiegel, A BollingerAbstract:Flow and pressure dynamics in minute human Lymphatics are unexplored. Lymphatic Capillary pressure was measured by the servo-nulling technique at the foot dorsum of 14 patients with primary lymphedema and 15 healthy controls. Glass micropipettes (7-9 μm) were inserted under microscopic control into Lymphatic microvessels previously stained by fluorescence microlymphography (FITC-Dextran 150,000). Mean Lymphatic Capillary pressure was 7.9 ± 3.4 mm Hg in the controls and 15.0 ± 5.1 mm Hg in the patients. The difference was significant at the P < 0.001 level. In about half of the patients and control subjects studied pressure fluctuated by more than 3 mm Hg. The mean intraLymphatic pressure of lymphedema patients was slightly below mean interstitial pressure measured by J. T. Christensen, N. J. Shaw, M. M. Hamas and H. K. Al Hassan (1985, Microcirc., Endothelium, Lymphatics2, 267-384) (17.9 mm Hg) in lower leg lymphedema. MicroLymphatic hypertension present in patients with primary lymphedema is probably an important factor for edema formation.
U K Franzeck - One of the best experts on this subject based on the ideXlab platform.
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effect of postural changes on human Lymphatic Capillary pressure of the skin
The Journal of Physiology, 1996Co-Authors: U K Franzeck, M Fischer, U Costanzo, I Herrig, A BollingerAbstract:1. The influence of postural changes on cutaneous Lymphatic Capillary pressure and venous pressure was measured at the dorsum of the foot in twelve healthy volunteers. Measurements were performed in the supine and sitting positions. 2. Lymphatic skin capillaries were visualized by fluorescence microlymphography with fluorescein isothiocyanate (FITC)-Dextran 150000. Subsequently a Lymphatic Capillary was punctured with a glass micropipette and pressure was measured using the servo-nulling technique. Lymphatic Capillary pressure, venous pressure, heart and respiration rates were recorded simultaneously. 3. Mean Lymphatic Capillary pressure was significantly higher (P = 0.0096) in the sitting (9.9 +/- 3.0 mmHg) than in the supine (3.9 +/- 4.2 mmHg) position. There was no significant difference (P = 0.09) between Lymphatic Capillary pressure and venous pressure (6.8 +/- 3.4 mmHg) in the supine position. During sitting mean Lymphatic Capillary pressure was significantly lower (P = 0.0022) than mean venous pressure (53.3 +/- 4.1 mmHg). The smaller increase in Lymphatic Capillary pressure may be caused by the discontinuous fluid column in the Lymphatic system and enhanced orthostatic contractile activity of Lymphatic collectors and precollectors. Spontaneous low frequency pressure fluctuations occurred in 89% of recordings during sitting, which was significantly (P = 0.02) higher than in the supine position (54%). 4. The present results support the suggestion of enhanced intrinsic contractile activity of lymph precollectors and collectors in the dependent position. This mechanism is primarily responsible for the propulsion of lymph from the periphery to the thoracic duct during quiet sitting, when extrinsic pumping by the calf muscles is not active.
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Flow velocity of single Lymphatic capillaries in human skin.
The American journal of physiology, 1996Co-Authors: M Fischer, U K Franzeck, U Costanzo, I Herrig, M Schiesser, U. Hoffmann, A BollingerAbstract:The purpose of this study was to investigate the previously unknown flow velocity in single Lymphatic capillaries of humans in the supine position. Fifteen healthy subjects (10 women and 5 men; mean age 35.8 +/- 13.1 yr) were studied. Ten microliters of fluorescein isothiocyanate-dextran (150,000 mol wt) were injected into the subepidermal layer of the foot dorsum. The filling of the microLymphatics from the resulting depot was visualized by fluorescence video microscopy and stored on videotape. Flow velocity in the microLymphatics was determined on the video screen by direct measurement of the advancement of dyed lymph during a given time. The following median velocities were obtained: 0.51 mm/s (0.27 and 0.61 mm/s for lower and upper quartiles, respectively) for velocity during initial network filling and 9.7 microns/s (6.9 and 14.2 microns/s for lower and upper quartiles, respectively) for resting velocity at the end of the filling period. Mean Lymphatic Capillary diameter was 54.8 +/- 8.2 microns, and mean network extension was 8.3 +/- 3.2 mm. The high filling velocities are probably due to increased interstitial pressure and volume caused by dye microinjection, whereas the values measured during the end of network filling seem to approach resting flow velocities.
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fluctuation of skin Lymphatic Capillary pressure in controls and in patients with primary lymphedema
Journal of Vascular Research, 1994Co-Authors: J Dorfflermelly, U K Franzeck, I Herrig, M Schiesser, A BollingerAbstract:The microLymphatic pressure was monitored by using the servo-nulling technique at the forefoot skin in 24 healthy volunteers (number of capillaries studied: 97) and in 27 patients with primary lymphedema (Capillary number: 67). The Lymphatic capillaries were stained by fluorescence microlymphography with fluorescein isothiocyanate-dextran 150 and cannulated using glass needles with a diameter between 7 and 9 µm. The Lymphatic Capillary hypertension described recently in primary lymphedema was confirmed in this series (mean pressure of controls 6.7 ± 3.8 and, of patients 12.8 ± 5.9 mm Hg; p
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Lymphatic Capillary pressure in patients with primary lymphedema
Microvascular Research, 1993Co-Authors: Beatrice R Zauggvesti, U K Franzeck, J Dorfflermelly, Michael Spiegel, A BollingerAbstract:Flow and pressure dynamics in minute human Lymphatics are unexplored. Lymphatic Capillary pressure was measured by the servo-nulling technique at the foot dorsum of 14 patients with primary lymphedema and 15 healthy controls. Glass micropipettes (7-9 μm) were inserted under microscopic control into Lymphatic microvessels previously stained by fluorescence microlymphography (FITC-Dextran 150,000). Mean Lymphatic Capillary pressure was 7.9 ± 3.4 mm Hg in the controls and 15.0 ± 5.1 mm Hg in the patients. The difference was significant at the P < 0.001 level. In about half of the patients and control subjects studied pressure fluctuated by more than 3 mm Hg. The mean intraLymphatic pressure of lymphedema patients was slightly below mean interstitial pressure measured by J. T. Christensen, N. J. Shaw, M. M. Hamas and H. K. Al Hassan (1985, Microcirc., Endothelium, Lymphatics2, 267-384) (17.9 mm Hg) in lower leg lymphedema. MicroLymphatic hypertension present in patients with primary lymphedema is probably an important factor for edema formation.
J Dorfflermelly - One of the best experts on this subject based on the ideXlab platform.
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fluctuation of skin Lymphatic Capillary pressure in controls and in patients with primary lymphedema
Journal of Vascular Research, 1994Co-Authors: J Dorfflermelly, U K Franzeck, I Herrig, M Schiesser, A BollingerAbstract:The microLymphatic pressure was monitored by using the servo-nulling technique at the forefoot skin in 24 healthy volunteers (number of capillaries studied: 97) and in 27 patients with primary lymphedema (Capillary number: 67). The Lymphatic capillaries were stained by fluorescence microlymphography with fluorescein isothiocyanate-dextran 150 and cannulated using glass needles with a diameter between 7 and 9 µm. The Lymphatic Capillary hypertension described recently in primary lymphedema was confirmed in this series (mean pressure of controls 6.7 ± 3.8 and, of patients 12.8 ± 5.9 mm Hg; p
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Lymphatic Capillary pressure in patients with primary lymphedema
Microvascular Research, 1993Co-Authors: Beatrice R Zauggvesti, U K Franzeck, J Dorfflermelly, Michael Spiegel, A BollingerAbstract:Flow and pressure dynamics in minute human Lymphatics are unexplored. Lymphatic Capillary pressure was measured by the servo-nulling technique at the foot dorsum of 14 patients with primary lymphedema and 15 healthy controls. Glass micropipettes (7-9 μm) were inserted under microscopic control into Lymphatic microvessels previously stained by fluorescence microlymphography (FITC-Dextran 150,000). Mean Lymphatic Capillary pressure was 7.9 ± 3.4 mm Hg in the controls and 15.0 ± 5.1 mm Hg in the patients. The difference was significant at the P < 0.001 level. In about half of the patients and control subjects studied pressure fluctuated by more than 3 mm Hg. The mean intraLymphatic pressure of lymphedema patients was slightly below mean interstitial pressure measured by J. T. Christensen, N. J. Shaw, M. M. Hamas and H. K. Al Hassan (1985, Microcirc., Endothelium, Lymphatics2, 267-384) (17.9 mm Hg) in lower leg lymphedema. MicroLymphatic hypertension present in patients with primary lymphedema is probably an important factor for edema formation.
Ye Li - One of the best experts on this subject based on the ideXlab platform.
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the correlation between ultrastructure of Lymphatic Capillary and neck lymph node metastasis laryngeal carcinoma
Journal of clinical otorhinolaryngology head and neck surgery, 2007Co-Authors: Ye LiAbstract:Objective To study the correlation between ultrastructure of Lymphatic Capillary in pericancerous tissue and neck lymph node metastasis in laryngeal carcinoma. Method Transmission electronic microscope was applied to observe and compare ultrastructure of Lymphatic Capillary in 8 normal laryngeal epithelial tissue and 12 pericancerous tissue of laryngeal cancer. Result Lymphatic Capillary of pericancerous tissue was significantly dilated compared with normal laryngeal tissue. A large amount of endothelial cell junction was open and devoid of basement membrane. Some endothelial cells of Lymphatic Capillary were destroyed or broken completely. Conclusion Ultrastructure of Lymphatic Capillary in pericancerous tissue is an important factor of laryngeal cancer metastasis through Lymphatic system. This research offers theoretic basis for laryngeal carcinoma metastasis mechanism and prevention.
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The correlation between ultrastructure of Lymphatic Capillary and neck lymph node metastasis laryngeal carcinoma
Journal of clinical otorhinolaryngology head and neck surgery, 2007Co-Authors: Ye LiAbstract:OBJECTIVE: To study the correlation between ultrastructure of Lymphatic Capillary in pericancerous tissue and neck lymph node metastasis in laryngeal carcinoma. METHOD: Transmission electronic microscope was applied to observe and compare ultrastructure of Lymphatic Capillary in 8 normal laryngeal epithelial tissue and 12 pericancerous tissue of laryngeal cancer. RESULT: Lymphatic Capillary of pericancerous tissue was significantly dilated compared with normal laryngeal tissue. A large amount of endothelial cell junction was open and devoid of basement membrane. Some endothelial cells of Lymphatic Capillary were destroyed or broken completely. CONCLUSION: Ultrastructure of Lymphatic Capillary in pericancerous tissue is an important factor of laryngeal cancer metastasis through Lymphatic system. This research offers theoretic basis for laryngeal carcinoma metastasis mechanism and prevention.
M. A. Swartz - One of the best experts on this subject based on the ideXlab platform.
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Multiscale modeling of Lymphatic drainage from tissues using homogenization theory
Journal of Biomechanics, 2012Co-Authors: Tiina Roose, M. A. SwartzAbstract:Lymphatic Capillary drainage of interstitial fluid under both steady-state and inflammatory conditions is important for tissue fluid balance, cancer metastasis, and immunity. Lymphatic drainage function is critically coupled to the fluid mechanical properties of the interstitium, yet this coupling is poorly understood. Here we sought to effectively model the Lymphatic-interstitial fluid coupling and ask why the Lymphatic Capillary network often appears with roughly a hexagonal architecture. We use homogenization method, which allows tissue-scale lymph flow to be integrated with the microstructural details of the Lymphatic capillaries, thus gaining insight into the functionality of Lymphatic anatomy. We first describe flow in Lymphatic capillaries using the Navier-Stokes equations and flow through the interstitium using Darcy's law. We then use multiscale homogenization to derive macroscale equations describing Lymphatic drainage, with the mouse tail skin as a basis. We find that the limiting resistance for fluid drainage is that from the interstitium into the capillaries rather than within the capillaries. We also find that between hexagonal, square, and parallel tube configurations of Lymphatic Capillary networks, the hexagonal structure is the most efficient architecture for coupled interstitial and Capillary fluid transport; that is, it clears the most interstitial fluid for a given network density and baseline interstitial fluid pressure. Thus, using homogenization theory, one can assess how vessel microstructure influences the macroscale fluid drainage by the Lymphatics and demonstrate why the hexagonal network of dermal Lymphatic capillaries is optimal for interstitial tissue fluid clearance. © 2011 Elsevier Ltd.
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Interstitial flow as a guide for lymphangiogenesis
Circulation Research, 2003Co-Authors: Kendrick C. Boardman, M. A. SwartzAbstract:The Lymphatic system is important in tissue fluid balance regulation, immune cell trafficking, edema, and cancer metastasis, yet very little is known about the sequence of events that initiate and coordinate lymphangiogenesis. Here, we characterize the process of Lymphatic regeneration by uniquely correlating interstitial fluid flow and Lymphatic endothelial cell migration with Lymphatic function. A new model of skin regeneration using a collagen implant in a mouse tail has been developed, and it shows that (1) interstitial fluid channels form before Lymphatic endothelial cell organization and (2) Lymphatic cell migration, vascular endothelial growth factor-C expression, and Lymphatic Capillary network organization are initiated primarily in the direction of lymph flow. These data suggest that interstitial fluid channeling precedes and may even direct lymphangiogenesis (in contrast to blood angiogenesis, in which fluid flow proceeds only after the vessel develops); thus, a novel and robust model is introduced for correlating molecular events with functionality in lymphangiogenesis.
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Transport in Lymphatic capillaries. II. Microscopic velocity measurement with fluorescence photobleaching.
The American journal of physiology, 1996Co-Authors: D A Berk, M. A. Swartz, R K JainAbstract:Despite its relevance to the physiology of lymph formation and propulsion, the instantaneous flow velocity in single Lymphatic capillaries has not been measured to date. The method of fluorescence recovery after photobleaching (FRAP) was adapted for this purpose and used to characterize flow in the Lymphatic capillaries in tail skin of anesthetized mice during a constant-pressure intradermal injection of fluorescein isothiocyanate-dextran (mol wt 2 x 10(6). The median lymph flow velocity was 4.7 microns/s, and the velocity magnitude ranged from 0 to 29 microns/s. The direction of flow was generally proximal, but stasis and backflow toward the site of injection was also detected. Evidence for oscillatory flow was detected in some FRAP experiments, and in separate experiments a periodicity of approximately 120 min-1, directly correlated to respiration frequency, was measured by tracking the motion of fluorescent latex microspheres (1 micron diam) introduced into the Lymphatic Capillary network. The velocity magnitude showed a correlation with duration of infusion but not with distance from injection site. It is speculated that the temporal decay of mean velocity magnitude could be related to the relaxation of local pressure gradients as partially collapsed vessels expand during the infusion.
