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Sample records for afferent lymphatic flow

  1. Treg engage lymphotoxin beta receptor for afferent lymphatic transendothelial migration

    PubMed Central

    Brinkman, C. Colin; Iwami, Daiki; Hritzo, Molly K.; Xiong, Yanbao; Ahmad, Sarwat; Simon, Thomas; Hippen, Keli L.; Blazar, Bruce R.; Bromberg, Jonathan S.

    2016-01-01

    Regulatory T cells (Tregs) are essential to suppress unwanted immunity or inflammation. After islet allo-transplant Tregs must migrate from blood to allograft, then via afferent lymphatics to draining LN to protect allografts. Here we show that Tregs but not non-Treg T cells use lymphotoxin (LT) during migration from allograft to draining LN, and that LT deficiency or blockade prevents normal migration and allograft protection. Treg LTαβ rapidly modulates cytoskeletal and membrane structure of lymphatic endothelial cells; dependent on VCAM-1 and non-canonical NFκB signalling via LTβR. These results demonstrate a form of T-cell migration used only by Treg in tissues that serves an important role in their suppressive function and is a unique therapeutic focus for modulating suppression. PMID:27323847

  2. A High-Salt Diet Differentially Modulates Mechanical Activity of Afferent and Efferent Collecting Lymphatics in Murine Iliac Lymph Nodes

    PubMed Central

    Mizuno, Risuke; Ono, Nobuyuki; Nishimoto, Mitsuhiro; Fujita, Toshiro

    2015-01-01

    Abstract Background: The lymphatic system contributes to fluid homeostasis in various tissues. Recent evidence suggests that lymphangiogenesis induced by a high-salt diet (HSD) is associated with blood pressure regulation. Lymph nodes, located along lymphatic pathways, are not only important secondary lymphoid tissues for cancer metastasis, inflammation, and immune responses, but are also important for fluid homeostasis. Afferent lymphatics collect lymph from the pre-nodal area and efferent lymphatics drain lymph out of the lymph nodes. However, the difference in mechanical activity between afferent and efferent lymphatics and the effect of a HSD on these vessels have not been shown. Methods and Results: Changes in mechanical activity of isolated afferent and efferent lymphatics in normal salt diet (NSD) and 4-week HSD mice in response to increases in intraluminal pressures from 3 to 7 cmH2O were measured using video-microscopy. The higher intramural pressure equivalently decreased pumping activity of afferent and efferent lymphatics in NSD mice. A HSD suppressed the amplitude, ejection fraction, and stroke volume of afferent lymphatics, leading to marked reductions in pumping activity. In contrast, the pumping activities of efferent lymphatics were resistant to a HSD and were preserved by enhancing the contraction frequency. Conclusions: A HSD differentially modulated the mechanical activity of afferent and efferent collecting lymphatics in murine iliac lymph nodes. PMID:26091404

  3. Interleukin-7 is produced by afferent lymphatic vessels and supports lymphatic drainage

    PubMed Central

    Iolyeva, Maria; Aebischer, David; Proulx, Steven T.; Willrodt, Ann-Helen; Ecoiffier, Tatiana; Häner, Simone; Bouchaud, Grégory; Krieg, Carsten; Onder, Lucas; Ludewig, Burkhard; Santambrogio, Laura; Boyman, Onur; Chen, Lu; Finke, Daniela

    2013-01-01

    The cytokine interleukin (IL)-7 exerts essential roles in lymph node (LN) organogenesis and lymphocyte development and homeostasis. Recent studies have identified lymphatic endothelial cells (LECs) as a major source of IL-7 in LNs. Here, we report that LECs not only produce IL-7, but also express the IL-7 receptor chains IL-7Rα and CD132. Stimulation with recombinant IL-7 enhanced LEC in vitro activity and induced lymphangiogenesis in the cornea of wild-type (WT) mice. Whereas in IL-7Rα−/− mice, dermal lymphatic vessels (LVs) were abnormally organized and lymphatic drainage was compromised, transgenic overexpression of IL-7 in mice resulted in an expanded dermal LV network with increased drainage function. Moreover, systemic treatment with recombinant IL-7 enhanced lymphatic drainage in the skin of WT mice and of mice devoid of lymphocytes. Experiments in IL-7Rα−/− bone marrow chimeras demonstrated that the drainage-enhancing activity of IL-7 was exclusively dependent on IL-7Rα expression in stromal but not in hematopoietic cells. Finally, near-infrared in vivo imaging performed in IL-7Rα−/− mice revealed that the pumping activity of collecting vessels was normal but fluid uptake into lymphatic capillaries was defective. Overall, our data point toward an unexpected new role for IL-7 as a potential autocrine mediator of lymphatic drainage. PMID:23963040

  4. Lymphovenous hemostasis and the role of platelets in regulating lymphatic flow and lymphatic vessel maturation.

    PubMed

    Welsh, John D; Kahn, Mark L; Sweet, Daniel T

    2016-09-01

    Aside from the established role for platelets in regulating hemostasis and thrombosis, recent research has revealed a discrete role for platelets in the separation of the blood and lymphatic vascular systems. Platelets are activated by interaction with lymphatic endothelial cells at the lymphovenous junction, the site in the body where the lymphatic system drains into the blood vascular system, resulting in a platelet plug that, with the lymphovenous valve, prevents blood from entering the lymphatic circulation. This process, known as "lymphovenous hemostasis," is mediated by activation of platelet CLEC-2 receptors by the transmembrane ligand podoplanin expressed by lymphatic endothelial cells. Lymphovenous hemostasis is required for normal lymph flow, and mice deficient in lymphovenous hemostasis exhibit lymphedema and sometimes chylothorax phenotypes indicative of lymphatic insufficiency. Unexpectedly, the loss of lymph flow in these mice causes defects in maturation of collecting lymphatic vessels and lymphatic valve formation, uncovering an important role for fluid flow in driving endothelial cell signaling during development of collecting lymphatics. This article summarizes the current understanding of lymphovenous hemostasis and its effect on lymphatic vessel maturation and synthesizes the outstanding questions in the field, with relationship to human disease. PMID:27385789

  5. Lymph flow regulates collecting lymphatic vessel maturation in vivo.

    PubMed

    Sweet, Daniel T; Jiménez, Juan M; Chang, Jeremy; Hess, Paul R; Mericko-Ishizuka, Patricia; Fu, Jianxin; Xia, Lijun; Davies, Peter F; Kahn, Mark L

    2015-08-01

    Fluid shear forces have established roles in blood vascular development and function, but whether such forces similarly influence the low-flow lymphatic system is unknown. It has been difficult to test the contribution of fluid forces in vivo because mechanical or genetic perturbations that alter flow often have direct effects on vessel growth. Here, we investigated the functional role of flow in lymphatic vessel development using mice deficient for the platelet-specific receptor C-type lectin-like receptor 2 (CLEC2) as blood backfills the lymphatic network and blocks lymph flow in these animals. CLEC2-deficient animals exhibited normal growth of the primary mesenteric lymphatic plexus but failed to form valves in these vessels or remodel them into a structured, hierarchical network. Smooth muscle cell coverage (SMC coverage) of CLEC2-deficient lymphatic vessels was both premature and excessive, a phenotype identical to that observed with loss of the lymphatic endothelial transcription factor FOXC2. In vitro evaluation of lymphatic endothelial cells (LECs) revealed that low, reversing shear stress is sufficient to induce expression of genes required for lymphatic valve development and identified GATA2 as an upstream transcriptional regulator of FOXC2 and the lymphatic valve genetic program. These studies reveal that lymph flow initiates and regulates many of the key steps in collecting lymphatic vessel maturation and development.

  6. Initial Afferent Lymphatic Vessels Controlling Outbound Leukocyte Traffic from Skin to Lymph Nodes

    PubMed Central

    Teijeira, Alvaro; Rouzaut, Ana; Melero, Ignacio

    2013-01-01

    Tissue drains fluid and macromolecules through lymphatic vessels (LVs), which are lined by a specialized endothelium that expresses peculiar differentiation proteins, not found in blood vessels (i.e., LYVE-1, Podoplanin, PROX-1, and VEGFR-3). Lymphatic capillaries are characteristically devoid of a continuous basal membrane and are anchored to the ECM by elastic fibers that act as pulling ropes which open the vessel to avoid edema if tissue volume increases, as it occurs upon inflammation. LVs are also crucial for the transit of T lymphocytes and antigen presenting cells from tissue to draining lymph nodes (LN). Importantly, cell traffic control across lymphatic endothelium is differently regulated under resting and inflammatory conditions. Under steady-state non-inflammatory conditions, leukocytes enter into the lymphatic capillaries through basal membrane gaps (portals). This entrance is integrin-independent and seems to be mainly guided by CCL21 chemokine gradients acting on leukocytes expressing CCR7. In contrast, inflammatory processes in lymphatic capillaries involve a plethora of cytokines, chemokines, leukocyte integrins, and other adhesion molecules. Importantly, under inflammation a role for integrins and their ligands becomes apparent and, as a consequence, the number of leukocytes entering the lymphatic capillaries multiplies several-fold. Enhancing transmigration of dendritic cells en route to LN is conceivably useful for vaccination and cancer immunotherapy, whereas interference with such key mechanisms may ameliorate autoimmunity or excessive inflammation. Recent findings illustrate how, transient cell-to-cell interactions between lymphatic endothelial cells and leukocytes contribute to shape the subsequent behavior of leukocytes and condition the LV for subsequent trans-migratory events. PMID:24368908

  7. Lymphangion coordination minimally affects mean flow in lymphatic vessels.

    PubMed

    Venugopal, Arun M; Stewart, Randolph H; Laine, Glen A; Dongaonkar, Ranjeet M; Quick, Christopher M

    2007-08-01

    The lymphatic system returns interstitial fluid to the central venous circulation, in part, by the cyclical contraction of a series of "lymphangion pumps" in a lymphatic vessel. The dynamics of individual lymphangions have been well characterized in vitro; their frequencies and strengths of contraction are sensitive to both preload and afterload. However, lymphangion interaction within a lymphatic vessel has been poorly characterized because it is difficult to experimentally alter properties of individual lymphangions and because the afterload of one lymphangion is coupled to the preload of another. To determine the effects of lymphangion interaction on lymph flow, we adapted an existing mathematical model of a lymphangion (characterizing lymphangion contractility, lymph viscosity, and inertia) to create a new lymphatic vessel model consisting of several lymphangions in series. The lymphatic vessel model was validated with focused experiments on bovine mesenteric lymphatic vessels in vitro. The model was then used to predict changes in lymph flow with different time delays between onset of contraction of adjacent lymphangions (coordinated case) and with different relative lymphangion contraction frequencies (noncoordinated case). Coordination of contraction had little impact on mean flow. Furthermore, orthograde and retrograde propagations of contractile waves had similar effects on flow. Model results explain why neither retrograde propagation of contractile waves nor the lack of electrical continuity between lymphangions adversely impacts flow. Because lymphangion coordination minimally affects mean flow in lymphatic vessels, lymphangions have flexibility to independently adapt to local conditions.

  8. Lymphatic vessel development: fluid flow and valve-forming cells.

    PubMed

    Kume, Tsutomu

    2015-08-01

    Hemodynamic forces regulate many aspects of blood vessel disease and development, including susceptibility to atherosclerosis and remodeling of primary blood vessels into a mature vascular network. Vessels of the lymphatic circulatory system are also subjected to fluid flow-associated forces, but the molecular and cellular mechanisms by which these forces regulate the formation and maintenance of lymphatic vessels remain largely uncharacterized. This issue of the JCI includes two articles that begin to address how fluid flow influences lymphatic vessel development and function. Sweet et al. demonstrate that lymph flow is essential for the remodeling of primary lymphatic vessels, for ensuring the proper distribution of smooth muscle cells (SMCs), and for the development and maturation of lymphatic valves. Kazenwadel et al. show that flow-induced lymphatic valve development is initiated by the upregulation of GATA2, which has been linked to lymphedema in patients with Emberger syndrome. Together, these observations and future studies inspired by these results have potential to lead to the development of strategies for the treatment of lymphatic disorders.

  9. Clinical Feasibility of Noninvasive Visualization of Lymphatic Flow using Principles of Spin Labeling MRI: Implications for Lymphedema Assessment

    PubMed Central

    Rane, Swati; Donahue, Paula M. C.; Towse, Ted; Ridner, Sheila; Chappell, Michael; Jordi, John; Gore, John; Donahue, Manus J.

    2015-01-01

    Purpose To extend a commonly employed, noninvasive arterial spin labeling (ASL) MRI method for measuring blood flow to evaluate lymphatic flow. Materials and Methods All volunteers (n=12) provided informed consent in accordance with IRB and HIPAA regulations. Quantitative relaxation time (T1 and T2) measurements were made in extracted human lymphatic fluid at 3.0T. Guided by these parameters, an ASL MRI approach was adapted to measure lymphatic flow (flow-alternating-inversion-recovery lymphatic water labeling; 3×3×5 mm3) in healthy subjects (n=6; 30±1 yrs; recruitment duration=2 months). Lymphatic flow velocity was quantified by performing spin labeling measurements as a function of post-labeling delay time and measuring the time-to-peak of signal in axillary lymph nodes. Clinical feasibility was evaluated in Stage II lymphedema patients (n=3; 60yr/F, 43yr/F, 64yr/F) and control subjects with unilateral cuff-induced lymphatic stenosis (n=3; 31yr/M, 31yr/M, 35yr/F). Results T1 and T2 of lymphatic fluid at 3.0T were 3100±160 ms (range=2930-3210 ms; median=3200 ms) and 610±12 ms (range=598-618 ms; median=610 ms), respectively. Healthy lymphatic flow (afferent vessel to axillary node) velocity was found to be 0.61±0.13 cm/min (n=6). A reduction (P<0.005) in lymphatic flow velocity in the affected arms of patients and the affected arms of healthy subjects with manipulated cuff-induced flow reduction was observed. The ratio of unaffected to affected axilla lymphatic velocity (1.24±0.18) was significantly (P<0.005) higher than the Left/Right ratio in healthy subjects (0.91±0.18). Conclusion This work provides a foundation for clinical investigations whereby lymphedema etiogenesis and therapies may be interrogated without exogenous agents and with clinically available imaging equipment. PMID:23864103

  10. Nodal lymph flow quantified with afferent vessel input function allows differentiation between normal and cancer-bearing nodes

    PubMed Central

    DSouza, Alisha V.; Elliott, Jonathan T.; Gunn, Jason R.; Barth, Richard J.; Samkoe, Kimberley S.; Tichauer, Kenneth M.; Pogue, Brian W.

    2015-01-01

    Morbidity and complexity involved in lymph node staging via surgical resection and biopsy could ideally be improved using node assay techniques that are non-invasive. While visible blue dyes are often used to locate the sentinel lymph nodes from draining lymphatic vessels near a tumor, they do not provide an in situ metric to evaluate presence of cancer. In this study, the transport kinetics of methylene blue were analyzed to determine the potential for better in situ information about metastatic involvement in the nodes. A rat model with cancer cells in the axillary lymph nodes was used, with methylene blue injection to image the fluorescence kinetics. The lymphatic flow from injection sites to nodes was imaged and the relative kinetics from feeding lymphatic ducts relative to lymph nodes was quantified. Large variability existed in raw fluorescence and transport patterns within each cohort resulting in no systematic difference between average nodal uptake in normal, sham control and cancer-bearing nodes. However, when the signal from the afferent lymph vessel fluorescence was used to normalize the signal of the lymph nodes, the high signal heterogeneity was reduced. Using a model, the lymph flow through the nodes (FLN) was estimated to be 1.49 ± 0.64 ml/g/min in normal nodes, 1.53 ± 0.45 ml/g/min in sham control nodes, and reduced to 0.50 ± 0.24 ml/g/min in cancer-cell injected nodes. This summarizes the significant difference (p = 0.0002) between cancer-free and cancer-bearing nodes in normalized flow. This process of normalized flow imaging could be used as an in situ tool to detect metastatic involvement in nodes. PMID:25909014

  11. Regulation of lymphatic capillary regeneration by interstitial flow in skin.

    PubMed

    Goldman, Jeremy; Conley, Kelly A; Raehl, Alisha; Bondy, Dona M; Pytowski, Bronislaw; Swartz, Melody A; Rutkowski, Joseph M; Jaroch, David B; Ongstad, Emily L

    2007-05-01

    Decreased interstitial flow (IF) in secondary lymphedema is coincident with poor physiological lymphatic regeneration. However, both the existence and direction of causality between IF and lymphangiogenesis remain unclear. This is primarily because the role of IF and its importance relative to the action of the prolymphangiogenic growth factor vascular endothelial growth factor (VEGF)-C (which signals primarily through its receptor VEGFR-3) are poorly understood. To clarify this, we explored the cooperative roles of VEGFR-3 and IF in a mouse model of lymphangiogenesis in regenerating skin. Specifically, a region of lymphangiogenesis was created by substituting a portion of mouse tail skin with a collagen gel within which lymphatic capillaries completely regenerate over a period of 60 days. The relative importance of IF and VEGF-C signaling were evaluated by either inhibiting VEGFR-3 signaling with antagonistic antibodies or by reducing IF. In some cases, VEGF-C signaling was then increased with exogenous protein. To clarify the role of IF, the distribution of endogenous matrix metalloproteinases (MMPs) and VEGF-C within the regenerating region was determined. It was found that inhibition of either VEGFR-3 or IF suppressed endogenous lymphangiogenesis. Reduction of IF was found to decrease lymphatic migration and transport of endogenous MMP and VEGF-C through the regenerating region. Therapeutic VEGF-C administration restored lymphangiogenesis following inhibition of VEGFR-3 but did not increase lymphangiogenesis following inhibition of IF. These results identify IF as an important regulator of the pro-lymphangiogenic action of VEGF-C.

  12. Altered lymphatics in an ovine model of congenital heart disease with increased pulmonary blood flow.

    PubMed

    Datar, Sanjeev A; Johnson, Eric G; Oishi, Peter E; Johengen, Michael; Tang, Eric; Aramburo, Angela; Barton, Jubilee; Kuo, Hsuan-Chang; Bennett, Stephen; Xoinis, Konstantine; Reel, Bhupinder; Kalkan, Gokhan; Sajti, Eniko; Osorio, Oscar; Raff, Gary W; Matthay, Michael A; Fineman, Jeffrey R

    2012-03-15

    Abnormalities of the lymphatic circulation are well recognized in patients with congenital heart defects. However, it is not known how the associated abnormal blood flow patterns, such as increased pulmonary blood flow (PBF), might affect pulmonary lymphatic function and structure. Using well-established ovine models of acute and chronic increases in PBF, we cannulated the efferent lymphatic duct of the caudal mediastinal node and collected and analyzed lymph effluent from the lungs of lambs with acutely increased PBF (n = 6), chronically increased PBF (n = 6), and age-matched normal lambs (n = 8). When normalized to PBF, we found that lymph flow was unchanged following acute increases in PBF but decreased following chronic increases in PBF. The lymph:plasma protein ratio decreased with both acute and chronic increases in PBF. Lymph bioavailable nitric oxide increased following acute increases in PBF but decreased following chronic increases in PBF. In addition, we found perturbations in the transit kinetics of contrast material through the pleural lymphatics of lambs with chronic increases in PBF. Finally, there were structural changes in the pulmonary lymphatic system in lambs with chronic increases in PBF: lymphatics from these lambs were larger and more dilated, and there were alterations in the expression of vascular endothelial growth factor-C, lymphatic vessel endothelial hyaluronan receptor-1, and Angiopoietin-2, proteins known to be important for lymphatic growth, development, and remodeling. Taken together these data suggest that chronic increases in PBF lead to both functional and structural aberrations of lung lymphatics. These findings have important therapeutic implications that warrant further study.

  13. Inhibition of the active lymph pump by flow in rat mesenteric lymphatics and thoracic duct

    NASA Technical Reports Server (NTRS)

    Gashev, Anatoliy A.; Davis, Michael J.; Zawieja, David C.; Delp, M. D. (Principal Investigator)

    2002-01-01

    There are only a few reports of the influence of imposed flow on an active lymph pump under conditions of controlled intraluminal pressure. Thus, the mechanisms are not clearly defined. Rat mesenteric lymphatics and thoracic ducts were isolated, cannulated and pressurized. Input and output pressures were adjusted to impose various flows. Lymphatic systolic and diastolic diameters were measured and used to determine contraction frequency and pump flow indices. Imposed flow inhibited the active lymph pump in both mesenteric lymphatics and in the thoracic duct. The active pump of the thoracic duct appeared more sensitive to flow than did the active pump of the mesenteric lymphatics. Imposed flow reduced the frequency and amplitude of the contractions and accordingly the active pump flow. Flow-induced inhibition of the active lymph pump followed two temporal patterns. The first pattern was a rapidly developing inhibition of contraction frequency. Upon imposition of flow, the contraction frequency immediately fell and then partially recovered over time during continued flow. This effect was dependent on the magnitude of imposed flow, but did not depend on the direction of flow. The effect also depended upon the rate of change in the direction of flow. The second pattern was a slowly developing reduction of the amplitude of the lymphatic contractions, which increased over time during continued flow. The inhibition of contraction amplitude was dependent on the direction of the imposed flow, but independent of the magnitude of flow. Nitric oxide was partly but not completely responsible for the influence of flow on the mesenteric lymph pump. Exposure to NO mimicked the effects of flow, and inhibition of the NO synthase by N (G)-monomethyl-L-arginine attenuated but did not completely abolish the effects of flow.

  14. Disrupted NOS signaling in lymphatic endothelial cells exposed to chronically increased pulmonary lymph flow.

    PubMed

    Datar, Sanjeev A; Gong, Wenhui; He, Youping; Johengen, Michael; Kameny, Rebecca J; Raff, Gary W; Maltepe, Emin; Oishi, Peter E; Fineman, Jeffrey R

    2016-07-01

    Associated abnormalities of the lymphatic circulation are well described in congenital heart disease. However, their mechanisms remain poorly elucidated. Using a clinically relevant ovine model of a congenital cardiac defect with chronically increased pulmonary blood flow (shunt), we previously demonstrated that exposure to chronically elevated pulmonary lymph flow is associated with: 1) decreased bioavailable nitric oxide (NO) in pulmonary lymph; and 2) attenuated endothelium-dependent relaxation of thoracic duct rings, suggesting disrupted lymphatic endothelial NO signaling in shunt lambs. To further elucidate the mechanisms responsible for this altered NO signaling, primary lymphatic endothelial cells (LECs) were isolated from the efferent lymphatic of the caudal mediastinal node in 4-wk-old control and shunt lambs. We found that shunt LECs (n = 3) had decreased bioavailable NO and decreased endothelial nitric oxide synthase (eNOS) mRNA and protein expression compared with control LECs (n = 3). eNOS activity was also low in shunt LECs, but, interestingly, inducible nitric oxide synthase (iNOS) expression and activity were increased in shunt LECs, as were total cellular nitration, including eNOS-specific nitration, and accumulation of reactive oxygen species (ROS). Pharmacological inhibition of iNOS reduced ROS in shunt LECs to levels measured in control LECs. These data support the conclusion that NOS signaling is disrupted in the lymphatic endothelium of lambs exposed to chronically increased pulmonary blood and lymph flow and may contribute to decreased pulmonary lymphatic bioavailable NO.

  15. Flow modulates myogenic responses in isolated microperfused rabbit afferent arterioles via endothelium-derived nitric oxide.

    PubMed Central

    Juncos, L A; Garvin, J; Carretero, O A; Ito, S

    1995-01-01

    Flow may be a physiological stimulus of the endothelial release of nitric oxide (NO) and prostaglandins (PGs). We tested the hypothesis that pressure-induced constriction of the glomerular afferent arteriole (Af-Art) is modulated by luminal flow via endothelial production of NO. We microdissected the terminal segment of an interlobular artery together with two Af-Arts, their glomeruli (GL) and efferent arterioles (Ef-Art). The two Af-Arts were perfused simultaneously from the interlobular artery, while one Ef-Art was occluded. Since the arteriolar perfusate contained 5% albumin, oncotic pressure built up in the glomerulus with the occluded Ef-Art and opposed the force of filtration, resulting in little or no flow through the corresponding Af-Art. Thus this preparation allowed us to observe free-flow and no-flow Af-Arts simultaneously during stepwise 30-mmHg increases in intraluminal pressure (from 30 to 120 mmHg). Pressure-induced constriction was weaker in free-flow than no-flow Af-Arts, with the luminal diameter decreasing by 11.1 +/- 1.7 and 25.6 +/- 2.3% (n = 30), respectively, at 120 mmHg. To examine whether flow modulates myogenic constriction through endothelium-derived NO and/or PGs, we examined pressure-induced constriction before and after (a) disruption of the endothelium, (b) inhibition of NO synthesis with NW-nitro-L-arginine methyl ester (L-NAME), or (c) inhibition of cyclooxygenase with indomethacin. Both endothelial disruption and L-NAME augmented pressure-induced constriction in free-flow but not no-flow Af-Arts, abolishing the differences between the two. However, indomethacin had no effect in either free-flow or no-flow Af-Arts. These results suggest that intraluminal flow attenuates pressure-induced constriction in Af-Arts via endothelium-derived NO. Thus flow-stimulated NO release may be important in the fine control of glomerular hemodynamics. Images PMID:7769114

  16. An in situ optical imaging system for measuring lipid uptake, vessel contraction, and lymph flow in small animal lymphatic vessels

    NASA Astrophysics Data System (ADS)

    Kassis, Timothy; Weiler, Michael J.; Dixon, J. Brandon

    2012-03-01

    All dietary lipids are transported to venous circulation through the lymphatic system, yet the underlying mechanisms that regulate this process remain unclear. Understanding how the lymphatics functionally respond to changes in lipid load is important in the diagnosis and treatment of lipid and lymphatic related diseases such as obesity, hypercholesterolemia, and lymphedema. Therefore, we sought to develop an in situ imaging system to quantify and correlate lymphatic function as it relates to lipid transport. A custom-built optical set-up provides us with the capability of dual-channel imaging of both high-speed bright-field video and fluorescence simultaneously. This is achieved by dividing the light path into two optical bands. Utilizing high-speed and back-illuminated CCD cameras and post-acquisition image processing algorithms, we have the potential quantify correlations between vessel contraction, lymph flow and lipid concentration of mesenteric lymphatic vessels in situ. Local flow velocity is measured through lymphocyte tracking, vessel contraction through measurements of the vessel walls and lipid uptake through fluorescence intensity tracking of a fluorescent long chain fatty acid analogue, Bodipy FL C16. This system will prove to be an invaluable tool for both scientists studying lymphatic function in health and disease, and those investigating strategies for targeting the lymphatic system with orally delivered drugs.

  17. Determining the combined effect of the lymphatic valve leaflets and sinus on resistance to forward flow.

    PubMed

    Wilson, John T; van Loon, Raoul; Wang, Wei; Zawieja, David C; Moore, James E

    2015-10-15

    The lymphatic system is vital to a proper maintenance of fluid and solute homeostasis. Collecting lymphatics are composed of actively contracting tubular vessels segmented by bulbous sinus regions that encapsulate bi-leaflet check valves. Valve resistance to forward flow strongly influences pumping performance. However, because of the sub-millimeter size of the vessels with flow rates typically <1 ml/h and pressures of a few cmH2O, resistance is difficult to measure experimentally. Using a newly defined idealized geometry, we employed an uncoupled approach where the solid leaflet deflections of the open valve were computed and lymph flow calculations were subsequently performed. We sought to understand: 1) the effect of sinus and leaflet size on the resulting deflections experienced by the valve leaflets and 2) the effects on valve resistance to forward flow of the fully open valve. For geometries with sinus-to-root diameter ratios >1.39, the average resistance to forward flow was 0.95×10(6)[g/(cm4 s)]. Compared to the viscous pressure drop that would occur in a straight tube the same diameter as the upstream lymphangion, valve leaflets alone increase the pressure drop up to 35%. However, the presence of the sinus reduces viscous losses, with the net effect that when combined with leaflets the overall resistance is less than that of the equivalent continuing straight tube. Accurately quantifying resistance to forward flow will add to the knowledge used to develop therapeutics for treating lymphatic disorders and may eventually lead to understanding some forms of primary lymphedema. PMID:26315921

  18. Determining the combined effect of the lymphatic valve leaflets and sinus on resistance to forward flow.

    PubMed

    Wilson, John T; van Loon, Raoul; Wang, Wei; Zawieja, David C; Moore, James E

    2015-10-15

    The lymphatic system is vital to a proper maintenance of fluid and solute homeostasis. Collecting lymphatics are composed of actively contracting tubular vessels segmented by bulbous sinus regions that encapsulate bi-leaflet check valves. Valve resistance to forward flow strongly influences pumping performance. However, because of the sub-millimeter size of the vessels with flow rates typically <1 ml/h and pressures of a few cmH2O, resistance is difficult to measure experimentally. Using a newly defined idealized geometry, we employed an uncoupled approach where the solid leaflet deflections of the open valve were computed and lymph flow calculations were subsequently performed. We sought to understand: 1) the effect of sinus and leaflet size on the resulting deflections experienced by the valve leaflets and 2) the effects on valve resistance to forward flow of the fully open valve. For geometries with sinus-to-root diameter ratios >1.39, the average resistance to forward flow was 0.95×10(6)[g/(cm4 s)]. Compared to the viscous pressure drop that would occur in a straight tube the same diameter as the upstream lymphangion, valve leaflets alone increase the pressure drop up to 35%. However, the presence of the sinus reduces viscous losses, with the net effect that when combined with leaflets the overall resistance is less than that of the equivalent continuing straight tube. Accurately quantifying resistance to forward flow will add to the knowledge used to develop therapeutics for treating lymphatic disorders and may eventually lead to understanding some forms of primary lymphedema.

  19. Microparticle image velocimetry approach to flow measurements in isolated contracting lymphatic vessels

    NASA Astrophysics Data System (ADS)

    Margaris, Konstantinos N.; Nepiyushchikh, Zhanna; Zawieja, David C.; Moore, James; Black, Richard A.

    2016-02-01

    We describe the development of an optical flow visualization method for resolving the flow velocity vector field in lymphatic vessels in vitro. The aim is to develop an experimental protocol for accurately estimating flow parameters, such as flow rate and shear stresses, with high spatial and temporal resolution. Previous studies in situ have relied on lymphocytes as tracers, but their low density resulted in a reduced spatial resolution whereas the assumption that the flow was fully developed in order to determine the flow parameters of interest may not be valid, especially in the vicinity of the valves, where the flow is undoubtedly more complex. To overcome these issues, we have applied the time-resolved microparticle image velocimetry (μ-PIV) technique, a well-established method that can provide increased spatial and temporal resolution that this transient flow demands. To that end, we have developed a custom light source, utilizing high-power light-emitting diodes, and associated control and image processing software. This paper reports the performance of the system and the results of a series of preliminary experiments performed on vessels isolated from rat mesenteries, demonstrating, for the first time, the successful application of the μ-PIV technique in these vessels.

  20. Microparticle image velocimetry approach to flow measurements in isolated contracting lymphatic vessels.

    PubMed

    Margaris, Konstantinos N; Nepiyushchikh, Zhanna; Zawieja, David C; Moore, James; Black, Richard A

    2016-02-01

    We describe the development of an optical flow visualization method for resolving the flow velocity vector field in lymphatic vessels in vitro. The aim is to develop an experimental protocol for accurately estimating flow parameters, such as flow rate and shear stresses, with high spatial and temporal resolution. Previous studies in situ have relied on lymphocytes as tracers, but their low density resulted in a reduced spatial resolution whereas the assumption that the flow was fully developed in order to determine the flow parameters of interest may not be valid, especially in the vicinity of the valves, where the flow is undoubtedly more complex. To overcome these issues, we have applied the time-resolved microparticle image velocimetry (μ -PIV) technique, a well-established method that can provide increased spatial and temporal resolution that this transient flow demands. To that end, we have developed a custom light source, utilizing high-power light-emitting diodes, and associated control and image processing software. This paper reports the performance of the system and the results of a series of preliminary experiments performed on vessels isolated from rat mesenteries, demonstrating, for the first time, the successful application of the μ -PIV technique in these vessels.

  1. An in vitro model of the tumor-lymphatic microenvironment with simultaneous transendothelial and luminal flows reveals mechanisms of flow enhanced invasion.

    PubMed

    Pisano, M; Triacca, V; Barbee, K A; Swartz, M A

    2015-05-01

    The most common cancers, including breast and skin, disseminate initially through the lymphatic system, yet the mechanisms by which tumor cells home towards, enter and interact with the lymphatic endothelium remain poorly understood. Transmural and luminal flows are important biophysical cues of the lymphatic microenvironment that can affect adhesion molecules, growth factors and chemokine expression as well as matrix remodeling, among others. Although microfluidic models are suitable for in vitro reconstruction of highly complex biological systems, the difficult assembly and operation of these systems often only allows a limited throughput. Here we present and characterize a novel flow chamber which recapitulates the lymphatic capillary microenvironment by coupling a standard Boyden chamber setup with a micro-channel and a controlled fluidic environment. The inclusion of luminal and transmural flow renders the model more biologically relevant, combining standard 3D culture techniques with advanced control of mechanical forces that are naturally present within the lymphatic microenvironment. The system can be monitored in real-time, allowing continuous quantification of different parameters of interest, such as cell intravasation and detachment from the endothelium, under varied biomechanical conditions. Moreover, the easy setup permits a medium-high throughput, thereby enabling downstream quantitative analyses. Using this model, we examined the kinetics of tumor cell (MDA-MB-231) invasion and transmigration dynamics across lymphatic endothelium under varying flow conditions. We found that luminal flow indirectly upregulates tumor cell transmigration rate via its effect on lymphatic endothelial cells. Moreover, we showed that the addition of transmural flow further increases intravasation, suggesting that distinct flow-mediated mechanisms regulate tumor cell invasion. PMID:25896438

  2. Colonic insult impairs lymph flow, increases cellular content of the lymph, alters local lymphatic micro-environment and leads to sustained inflammation in the rat ileum

    PubMed Central

    Cromer, Walter; Wang, Wei; Zawieja, Scott D.; von der Weid, Pierre-Yves; Newell Rogers, M. Karen; Zawieja, David C.

    2015-01-01

    Background Lymphatic dysfunction has been linked to inflammation since the 1930’s. Lymphatic function in the gut and mesentery is grossly underexplored in models of IBD despite the use of lymphatic occlusion in early models of IBD. Activation of the innate and adaptive immune system is a hallmark of TNBS-induced inflammation and is linked to disruption of the intrinsic lymph pump. Recent identification of crosstalk between lymphatic vessel resident immune cells and regulation of lymphatic vessel contractility underscore the importance of the timing of lymphatic dysfunction during tissue inflammation in response to TNBS. Methods To evaluate lymphatic function in TNBS induced inflammation, lymph was collected and flow measured from mesenteric lymphatics. Cellularity and cytokine profile of the lymph was also measured. Histopathology was performed to determine severity of injury and immunofluorescent staining of the mesentery was done to evaluate changes in the population of immune cells that reside near and on gastro-intestinal collecting lymphatics. Results Lymph transport fell 24hrs after TNBS administration and began recovering at 72hrs. Significant reduction of lymph flow preceded significant increase in histopathological score and occurred simultaneously with increased MPO activity. These changes were preceded by increased MHCII+ cells surrounding mesenteric lymphatics leading to an altered lymphatic environment that would favor dysfunction. Conclusions Alterations in environmental factors that effect lymphatic function occur before the development of gross GI inflammation. Reduced lymphatic function in TNBS-mediated inflammation is likely an early factor in the development of injury and that recovery of function is associated with resolution of inflammation. PMID:25939039

  3. Pharmacological Approaches That Slow Lymphatic Flow As a Snakebite First Aid

    PubMed Central

    van Helden, Dirk F.; Thomas, Paul A.; Dosen, Peter J.; Imtiaz, Mohammad S.; Laver, Derek R.; Isbister, Geoffrey K.

    2014-01-01

    Background This study examines the use of topical pharmacological agents as a snakebite first aid where slowing venom reaching the circulation prevents systemic toxicity. It is based on the fact that toxin molecules in most snake venoms are large molecules and generally first enter and traverse the lymphatic system before accessing the circulation. It follows on from a previous study where it was shown that topical application of a nitric oxide donor slowed lymph flow to a similar extent in humans and rats as well as increased the time to respiratory arrest for subcutaneous injection of an elapid venom (Pseudonaja textilis, Ptx; Eastern brown snake) into the hind feet of anaesthetized rats. Methodology/Principal Findings The effects of topical application of the L-type Ca2+ channel antagonist nifedipine and the local anesthetic lignocaine in inhibiting lymph flow and protecting against envenomation was examined in an anaesthetized rat model. The agents significantly increased dye-measured lymph transit times by 500% and 390% compared to controls and increased the time to respiratory arrest to foot injection of a lethal dose of Ptx venom by 60% and 40% respectively. The study also examined the effect of Ptx venom dose over the lethal range of 0.4 to 1.5 mg/kg finding a negative linear relationship between increase in venom dose and time to respiratory arrest. Conclusions/Significance The findings suggest that a range of agents that inhibit lymphatic flow could potentially be used as an adjunct treatment to pressure bandaging with immobilization (PBI) in snakebite first aid. This is important given that PBI (a snakebite first aid recommended by the Australian National Health and Medical research Council) is often incorrectly applied. The use of a local anesthetic would have the added advantage of reducing pain. PMID:24587472

  4. Mechanical forces and lymphatic transport.

    PubMed

    Breslin, Jerome W

    2014-11-01

    This review examines the current understanding of how the lymphatic vessel network can optimize lymph flow in response to various mechanical forces. Lymphatics are organized as a vascular tree, with blind-ended initial lymphatics, precollectors, prenodal collecting lymphatics, lymph nodes, postnodal collecting lymphatics and the larger trunks (thoracic duct and right lymph duct) that connect to the subclavian veins. The formation of lymph from interstitial fluid depends heavily on oscillating pressure gradients to drive fluid into initial lymphatics. Collecting lymphatics are segmented vessels with unidirectional valves, with each segment, called a lymphangion, possessing an intrinsic pumping mechanism. The lymphangions propel lymph forward against a hydrostatic pressure gradient. Fluid is returned to the central circulation both at lymph nodes and via the larger lymphatic trunks. Several recent developments are discussed, including evidence for the active role of endothelial cells in lymph formation; recent developments on how inflow pressure, outflow pressure, and shear stress affect the pump function of the lymphangion; lymphatic valve gating mechanisms; collecting lymphatic permeability; and current interpretations of the molecular mechanisms within lymphatic endothelial cells and smooth muscle. An improved understanding of the physiological mechanisms by which lymphatic vessels sense mechanical stimuli, integrate the information, and generate the appropriate response is key for determining the pathogenesis of lymphatic insufficiency and developing treatments for lymphedema. PMID:25107458

  5. Mechanical Forces and Lymphatic Transport

    PubMed Central

    Breslin, Jerome W.

    2014-01-01

    This review examines current understanding of how the lymphatic vessel network can optimize lymph flow in response to various mechanical forces. Lymphatics are organized as a vascular tree, with blind-ended initial lymphatics, precollectors, prenodal collecting lymphatics, lymph nodes, postnodal collecting lymphatics and the larger trunks (thoracic duct and right lymph duct) that connect to the subclavian veins. The formation of lymph from interstitial fluid depends heavily on oscillating pressure gradients to drive fluid into initial lymphatics. Collecting lymphatics are segmented vessels with unidirectional valves, with each segment, called a lymphangion, possessing an intrinsic pumping mechanism. The lymphangions propel lymph forward against a hydrostatic pressure gradient. Fluid is returned to the central circulation both at lymph nodes and via the larger lymphatic trunks. Several recent developments are discussed, including: evidence for the active role of endothelial cells in lymph formation; recent developments on how inflow pressure, outflow pressure, and shear stress affect pump function of the lymphangion; lymphatic valve gating mechanisms; collecting lymphatic permeability; and current interpretations of the molecular mechanisms within lymphatic endothelial cells and smooth muscle. Improved understanding of the physiological mechanisms by lymphatic vessels sense mechanical stimuli, integrate the information, and generate the appropriate response is key for determining the pathogenesis of lymphatic insufficiency and developing treatments for lymphedema. PMID:25107458

  6. Mechanical forces and lymphatic transport.

    PubMed

    Breslin, Jerome W

    2014-11-01

    This review examines the current understanding of how the lymphatic vessel network can optimize lymph flow in response to various mechanical forces. Lymphatics are organized as a vascular tree, with blind-ended initial lymphatics, precollectors, prenodal collecting lymphatics, lymph nodes, postnodal collecting lymphatics and the larger trunks (thoracic duct and right lymph duct) that connect to the subclavian veins. The formation of lymph from interstitial fluid depends heavily on oscillating pressure gradients to drive fluid into initial lymphatics. Collecting lymphatics are segmented vessels with unidirectional valves, with each segment, called a lymphangion, possessing an intrinsic pumping mechanism. The lymphangions propel lymph forward against a hydrostatic pressure gradient. Fluid is returned to the central circulation both at lymph nodes and via the larger lymphatic trunks. Several recent developments are discussed, including evidence for the active role of endothelial cells in lymph formation; recent developments on how inflow pressure, outflow pressure, and shear stress affect the pump function of the lymphangion; lymphatic valve gating mechanisms; collecting lymphatic permeability; and current interpretations of the molecular mechanisms within lymphatic endothelial cells and smooth muscle. An improved understanding of the physiological mechanisms by which lymphatic vessels sense mechanical stimuli, integrate the information, and generate the appropriate response is key for determining the pathogenesis of lymphatic insufficiency and developing treatments for lymphedema.

  7. Mechanobiology of lymphatic contractions.

    PubMed

    Munn, Lance L

    2015-02-01

    The lymphatic system is responsible for controlling tissue fluid pressure by facilitating flow of lymph (i.e. the plasma and cells that enter the lymphatic system). Because lymph contains cells of the immune system, its transport is not only important for fluid homeostasis, but also immune function. Lymph drainage can occur via passive flow or active pumping, and much research has identified the key biochemical and mechanical factors that affect output. Although many studies and reviews have addressed how tissue properties and fluid mechanics (i.e. pressure gradients) affect lymph transport [1-3] there is less known about lymphatic mechanobiology. As opposed to passive mechanical properties, mechanobiology describes the active coupling of mechanical signals and biochemical pathways. Lymphatic vasomotion is the result of a fascinating system affected by mechanical forces exerted by the flowing lymph, including pressure-induced vessel stretch and flow-induced shear stresses. These forces can trigger or modulate biochemical pathways important for controlling the lymphatic contractions. Here, I review the current understanding of lymphatic vessel function, focusing on vessel mechanobiology, and summarize the prospects for a comprehensive understanding that integrates the mechanical and biomechanical control mechanisms in the lymphatic system.

  8. Lymphatic Diseases

    MedlinePlus

    The lymphatic system is a network of tissues and organs. It is made up of Lymph - a fluid that contains ... They are part of the system, too. The lymphatic system clears away infection and keeps your body fluids ...

  9. Lymphatic obstruction

    MedlinePlus

    ... certain directions based on the structure of the lymphatic system. This helps the lymph fluid drain through the ... always appropriate or effective. Alternative Names Lymphedema Images Lymphatic system Yellow nail syndrome References Kurklinsky AK, Rooke TW. ...

  10. Activation of GLP-1 receptors on vascular smooth muscle cells reduces the autoregulatory response in afferent arterioles and increases renal blood flow.

    PubMed

    Jensen, Elisa P; Poulsen, Steen S; Kissow, Hannelouise; Holstein-Rathlou, Niels-Henrik; Deacon, Carolyn F; Jensen, Boye L; Holst, Jens J; Sorensen, Charlotte M

    2015-04-15

    Glucagon-like peptide (GLP)-1 has a range of extrapancreatic effects, including renal effects. The mechanisms are poorly understood, but GLP-1 receptors have been identified in the kidney. However, the exact cellular localization of the renal receptors is poorly described. The aim of the present study was to localize renal GLP-1 receptors and describe GLP-1-mediated effects on the renal vasculature. We hypothesized that renal GLP-1 receptors are located in the renal microcirculation and that activation of these affects renal autoregulation and increases renal blood flow. In vivo autoradiography using (125)I-labeled GLP-1, (125)I-labeled exendin-4 (GLP-1 analog), and (125)I-labeled exendin 9-39 (GLP-1 receptor antagonist) was performed in rodents to localize specific GLP-1 receptor binding. GLP-1-mediated effects on blood pressure, renal blood flow (RBF), heart rate, renin secretion, urinary flow rate, and Na(+) and K(+) excretion were investigated in anesthetized rats. Effects of GLP-1 on afferent arterioles were investigated in isolated mouse kidneys. Specific binding of (125)I-labeled GLP-1, (125)I-labeled exendin-4, and (125)I-labeled exendin 9-39 was observed in the renal vasculature, including afferent arterioles. Infusion of GLP-1 increased blood pressure, RBF, and urinary flow rate significantly in rats. Heart rate and plasma renin concentrations were unchanged. Exendin 9-39 inhibited the increase in RBF. In isolated murine kidneys, GLP-1 and exendin-4 significantly reduced the autoregulatory response of afferent arterioles in response to stepwise increases in pressure. We conclude that GLP-1 receptors are located in the renal vasculature, including afferent arterioles. Activation of these receptors reduces the autoregulatory response of afferent arterioles to acute pressure increases and increases RBF in normotensive rats.

  11. Nonmalignant Adult Thoracic Lymphatic Disorders.

    PubMed

    Itkin, Maxim; McCormack, Francis X

    2016-09-01

    The thoracic lymphatic disorders are a heterogeneous group of uncommon conditions that are associated with thoracic masses, interstitial pulmonary infiltrates, and chylous complications. Accurate diagnosis of the thoracic lymphatic disorders has important implications for the newest approaches to management, including embolization and treatment with antilymphangiogenic drugs. New imaging techniques to characterize lymphatic flow, such as dynamic contrast-enhanced magnetic resonance lymphangiogram, are redefining approaches to disease classification and therapy. PMID:27514588

  12. Mapping superficial lymphatic territories in the rabbit.

    PubMed

    Soto-Miranda, Miguel A; Suami, Hiroo; Chang, David W

    2013-06-01

    Little is known about the anatomy of the lymphatic system in the rabbit with regard to relationships between the lymphatic vessel and lymph node. According to our previous studies in human cadavers and canines, the superficial lymphatic system could be divided into lymphatic territories. The aim of this study was to completely map the superficial lymphatic system in the rabbit. We used our microinjection technique and histological analysis for dissecting studies and recently developed indocyanine green (ICG) fluorescent lymphography for demonstrating dynamic lymph flow in living rabbits. Real-time ICG fluorescent lymphography was performed in two living New Zealand White rabbits, and direct dye microinjection of the lymphatic vessels was performed in eight dead rabbits. To assess the relationships between the vascular and lymphatic systems in rabbits, we performed radiocontrast injection into arteries in two dead rabbits prior to the lymphatic injection. The ICG fluorescent lymphography revealed eight lymphatic territories in the preauricular, submandibular, root of the lateral neck, axillary, lumbar, inguinal, root of the tail, and popliteal regions. We injected blue acrylic dye into every lymphatic vessel 0.1 mm in diameter or larger. We then dissected and chased the stained lymphatic vessels proximally until the vessels connected to the first tier lymph node. This procedure was repeated throughout the body until all the relationships between the lymphatic vessels and lymph nodes were defined. The lymphatic system of the rabbit could be defined as eight lymphatic territories, each with its own lymphatic vessels and lymph node.

  13. Lymphatic Filariasis

    MedlinePlus

    ... Search The CDC Cancel Submit Search The CDC Parasites - Lymphatic Filariasis Note: Javascript is disabled or is ... this? Submit Button Information For: Travelers Related Links Parasites A-Z Index Parasites Glossary Neglected Tropical Diseases ...

  14. [The prognostic value of evaluation of minimal residual disease using technique of flow cytofluorometry during application of therapy of chronic lymphatic leukemia].

    PubMed

    Kisilichina, D G; Lugovskaia, C A; Naumova, E V; Pochtar', M E; Nikitin, E A; Dolgov, V V

    2014-11-01

    The achievement of molecular remission is associated with increasing of survival of patients with chronic lymphatic leukemia. The important direction of research is seeking of parameters applicable to forecast of response to therapy. The purpose of the study was evaluating prognostic significance of indicator of minimal residual disease detected by technique of flow cytofluorometry of peripheral blood of patients with chronic lymphatic leukemia during therapy application. The sampling included 112 patients with chronic lymphatic leukemia aged from 43 to 82 years. All patients were given treatment consisted of 6 courses of immune chemotherapy combined with fludarabine with cyclophosphan and rituximab. The samples of peripheral blood were analyzed after 3 courses during therapy and after 6 courses after completion of treatment. The cells were analyzed using 5 and 6 color flow cytometry for the purpose of detection of immune phenotype associated with chronic lymphatic leukemia. The evaluation of minimal residual disease was implemented according international standardized protocol (Rawstron A.C. et al. 2007; 21 (5): 956-64). The minimal residual disease negative status was reached in 87 (78%) patients during evaluation of response after 6th course of treatment. The implementation of indicators of residual disease after 3 courses with fludarabine, cyclophosphan and rituximab permitted to sort out two groups of patients with chronic lymphatic leukemia i.e 67 patients with low (< 0.12%) level of minimal residual disease and 45 patients with high (> 0.12%) level of tumor cells. The rate of molecular remission after completion of treatment. in the given groups consisted 100% and 44% correspondingly. The study demonstrates possibilities of early immune phenotype evaluation of minimal residual disease to forecast differences in response to treatment in patients with chronic lymphatic leukemia that makes it possible to avoid undesirable toxicity of therapy or to choose method

  15. Fluid-solid modeling of lymphatic valves

    NASA Astrophysics Data System (ADS)

    Caulk, Alexander; Ballard, Matthew; Nepiyushchikh, Zhanna; Dixon, Brandon; Alexeev, Alexander

    2015-11-01

    The lymphatic system performs important physiological functions such as the return of interstitial fluid to the bloodstream to maintain tissue fluid balance, as well as the transport of immune cells in the body. It utilizes contractile lymphatic vessels, which contain valves that open and close to allow flow in only one direction, to directionally pump lymph against a pressure gradient. We develop a fluid-solid model of geometrically representative lymphatic valves. Our model uses a hybrid lattice-Boltzmann lattice spring method to capture fluid-solid interactions with two-way coupling between a viscous fluid and lymphatic valves in a lymphatic vessel. We use this model to investigate the opening and closing of lymphatic valves, and its effect on lymphatic pumping. This helps to broaden our understanding of the fluid dynamics of the lymphatic system.

  16. Lymphatic flow in humans as indicated by the clearance of /sup 125/I-labeled albumin from the subcutaneous tissue of the leg

    SciTech Connect

    Fernandez, M.J.; Davies, W.T.; Owen, G.M.; Tyler, A.

    1983-08-01

    Since the removal of albumin from the extracellular space and its return to the vascular compartment is the essential function of the lymphatic system, the rate at which it is removed from the interstitial tissue may be regarded as a means of estimating lymphatic efficiency. An objective measure of lymphatic function can be obtained by monitoring the rate of clearance following injection of /sup 125/I-labeled albumin (RIHSA) from the subcutaneous tissue of a limb. The clearance of /sup 125/I-RIHSA from lower limb was monitored in a group of patients with normal limbs, patients with unilateral edema due to deep vein thrombosis, and patients with bilateral edema due to hypoproteinemia. The mean T1/2 in normal legs was 32.7 hr, compared to 23.7 hr in edematous limbs due to deep vein thrombosis and 19.4 in edematous limbs due to hypoproteinemia. There is a clear-cut difference in clearance rate between edematous and nonedematous limbs. This suggests that lymphatic flow is increased in edema due to venous obstruction and hypoproteinemia.

  17. Preclinical lymphatic imaging.

    PubMed

    Zhang, Fan; Niu, Gang; Lu, Guangming; Chen, Xiaoyuan

    2011-08-01

    Noninvasive in vivo imaging of lymphatic vessels and lymphatic nodes is expected to fulfill the purpose of analyzing lymphatic vessels and their function, understanding molecular mechanisms of lymphangiogenesis and lymphatic spread of tumors, and utilizing lymphatic molecular markers as a prognostic or diagnostic indicator. In this review, we provide a comprehensive summary of in vivo imaging modalities for detecting lymphatic vessels, lymphatic drainage, and lymphatic nodes, which include conventional lymphatic imaging techniques such as dyes and radionuclide scintigraphy as well as novel techniques for lymphatic imaging such as optical imaging, computed tomography, magnetic resonance imaging, ultrasound, positron emission tomography using lymphatic biomarkers, photoacoustic imaging, and combinations of multiple modalities. The field of lymphatic imaging is ever evolving, and technological advances, combined with the development of new contrast agents, continue to improve the research of lymphatic vascular system in health and disease states as well as to improve the accuracy of diagnosis in the relevant diseases.

  18. Preclinical Lymphatic Imaging

    PubMed Central

    Zhang, Fan; Niu, Gang; Lu, Guangming; Chen, Xiaoyuan

    2011-01-01

    Non-invasive in vivo imaging of lymphatic vessels and lymphatic nodes is expected to fulfill the purpose of analyzing lymphatic vessels and their function, understanding molecular mechanisms of lymphangiogenesis and lymphatic spread of tumors, and utilizing lymphatic molecular markers as a prognostic or diagnostic indicator. In this review, we provide a comprehensive summary of in vivo imaging modalities for detecting lymphatic vessels, lymphatic drainage, lymphatic nodes, which include conventional lymphatic imaging techniques such as dyes and radionuclide scintigraphy as well as novel techniques for lymphatic imaging such as optical imaging, computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, positron emission tomography (PET) using lymphatic biomarkers, photoacoustic imaging and combinations of multiple modalities. The field of lymphatic imaging is ever evolving, and technological advances, combined with the development of new contrast agents, continue to improve the research of lymphatic vascular system in health and disease states as well as to improve the accuracy of diagnosis in the relevant diseases. PMID:20862613

  19. Blunted flow-mediated responses and diminished nitric oxide synthase expression in lymphatic thoracic ducts of a rat model of metabolic syndrome.

    PubMed

    Zawieja, Scott D; Gasheva, Olga; Zawieja, David C; Muthuchamy, Mariappan

    2016-02-01

    Shear-dependent inhibition of lymphatic thoracic duct (TD) contractility is principally mediated by nitric oxide (NO). Endothelial dysfunction and poor NO bioavailability are hallmarks of vasculature dysfunction in states of insulin resistance and metabolic syndrome (MetSyn). We tested the hypothesis that flow-dependent regulation of lymphatic contractility is impaired under conditions of MetSyn. We utilized a 7-wk high-fructose-fed male Sprague-Dawley rat model of MetSyn and determined the stretch- and flow-dependent contractile responses in an isobaric ex vivo TD preparation. TD diameters were tracked and contractile parameters were determined in response to different transmural pressures, imposed flow, exogenous NO stimulation by S-nitro-N-acetylpenicillamine (SNAP), and inhibition of NO synthase (NOS) by l-nitro-arginine methyl ester (l-NAME) and the reactive oxygen species (ROS) scavenging molecule 4-hydroxy-tempo (tempol). Expression of endothelial NO synthase (eNOS) in TD was determined using Western blot. Approximately 25% of the normal flow-mediated inhibition of contraction frequency was lost in TDs isolated from MetSyn rats despite a comparable SNAP response. Inhibition of NOS with l-NAME abolished the differences in the shear-dependent contraction frequency regulation between control and MetSyn TDs, whereas tempol did not restore the flow responses in MetSyn TDs. We found a significant reduction in eNOS expression in MetSyn TDs suggesting that diminished NO production is partially responsible for impaired flow response. Thus our data provide the first evidence that MetSyn conditions diminish eNOS expression in TD endothelium, thereby affecting the flow-mediated changes in TD lymphatic function.

  20. Lymphatic Anomalies Registry

    ClinicalTrials.gov

    2016-07-26

    Lymphatic Malformation; Generalized Lymphatic Anomaly (GLA); Central Conducting Lymphatic Anomaly; CLOVES Syndrome; Gorham-Stout Disease ("Disappearing Bone Disease"); Blue Rubber Bleb Nevus Syndrome; Kaposiform Lymphangiomatosis; Kaposiform Hemangioendothelioma/Tufted Angioma; Klippel-Trenaunay Syndrome; Lymphangiomatosis

  1. Lymphatic system: an active pathway for immune protection.

    PubMed

    Liao, Shan; von der Weid, P Y

    2015-02-01

    Lymphatic vessels are well known to participate in the immune response by providing the structural and functional support for the delivery of antigens and antigen presenting cells to draining lymph nodes. Recent advances have improved our understanding of how the lymphatic system works and how it participates to the development of immune responses. New findings suggest that the lymphatic system may control the ultimate immune response through a number of ways which may include guiding antigen/dendritic cells (DC) entry into initial lymphatics at the periphery; promoting antigen/DC trafficking through afferent lymphatic vessels by actively facilitating lymph and cell movement; enabling antigen presentation in lymph nodes via a network of lymphatic endothelial cells and lymph node stroma cell and finally by direct lymphocytes exit from lymph nodes. The same mechanisms are likely also important to maintain peripheral tolerance. In this review we will discuss how the morphology and gene expression profile of the lymphatic endothelial cells in lymphatic vessels and lymph nodes provides a highly efficient pathway to initiate immune responses. The fundamental understanding of how lymphatic system participates in immune regulation will guide the research on lymphatic function in various diseases.

  2. Anatomy of the lymphatics.

    PubMed

    Skandalakis, John E; Skandalakis, Lee J; Skandalakis, Panagiotis N

    2007-01-01

    The lymphatic system is perhaps the most complicated system of Homo sapiens. An introduction to the anatomy, embryology, and anomalies of the lymphatics is presented. The overall anatomy and drainage of the lymphatic vessels in outlined. The topographic anatomy, relations, and variations of the principle vessels of the lymphatic system (the right lymphatic duct, the thoracic duct, and the cisterna chyli) are presented in detail.

  3. An Image-Based Model of Fluid Flow Through Lymph Nodes.

    PubMed

    Cooper, Laura J; Heppell, James P; Clough, Geraldine F; Ganapathisubramani, Bharathram; Roose, Tiina

    2016-01-01

    The lymphatic system returns fluid to the bloodstream from the tissues to maintain tissue fluid homeostasis. Lymph nodes distributed throughout the system filter the lymphatic fluid. The afferent and efferent lymph flow conditions of lymph nodes can be measured in experiments; however, it is difficult to measure the flow within the nodes. In this paper, we present an image-based modelling approach to investigating how the internal structure of the node affects the fluid flow pathways within the node. Selective plane illumination microscopy images of murine lymph nodes are used to identify the geometry and structure of the tissue within the node and to determine the permeability of the lymph node interstitium to lymphatic fluid. Experimental data are used to determine boundary conditions and optimise the parameters for the model. The numerical simulations conducted within the model are implemented in COMSOL Multiphysics, a commercial finite element analysis software. The parameter fitting resulted in the estimate that the average permeability for lymph node tissue is of the order of magnitude of [Formula: see text]. Our modelling shows that the flow predominantly takes a direct path between the afferent and efferent lymphatics and that fluid is both filtered and absorbed across the blood vessel boundaries. The amount that is absorbed or extravasated in the model is dependent on the efferent lymphatic lumen fluid pressure. PMID:26690921

  4. Species differences in the reflex effects of lingual afferent nerve stimulation on lip blood flow and arterial pressure.

    PubMed

    Koeda, S; Yasuda, M; Izumi, H

    2003-11-01

    We evoked changes in lower lip blood flow and systemic arterial blood pressure by electrically stimulating the central cut end of the lingual nerve in artificially ventilated, urethane-anesthetized, cervically vago-sympathectomized cats, rats, rabbits, and guinea pig. The systemic arterial blood pressure changes were species-dependent: increases in rat, consistent decreases in rabbit and guinea pig, and variable among individuals in cat. In cat and rabbit, lip blood flow increases, which occurred only ipsilaterally to the stimulated nerve and showed no statistically significant correlation with the systemic arterial blood pressure changes. In rat, the ipsilateral lip blood flow increase was markedly greater than the contralateral one, and although there was a significant correlation between each of them and the systemic arterial blood pressure changes, the ipsilateral increase presumably included an active vasodilatation. In guinea pig, lip blood flow decreased on both sides in proportion to the systemic arterial blood pressure reductions. Thus, species variability exists in the sympathetic-mediated systemic arterial blood pressure changes and parasympathetic-mediated lip blood flow responses themselves, and in the relationship between them. PMID:12920546

  5. Imaging the lymphatic system.

    PubMed

    Munn, Lance L; Padera, Timothy P

    2014-11-01

    Visualization of the lymphatic system is clinically necessary during diagnosis or treatment of many conditions and diseases; it is used for identifying and monitoring lymphedema, for detecting metastatic lesions during cancer staging and for locating lymphatic structures so they can be spared during surgical procedures. Imaging lymphatic anatomy and function also plays an important role in experimental studies of lymphatic development and function, where spatial resolution and accessibility are better. Here, we review technologies for visualizing and imaging the lymphatic system for clinical applications. We then describe the use of lymphatic imaging in experimental systems as well as some of the emerging technologies for improving these methodologies.

  6. Imaging the lymphatic system

    PubMed Central

    Munn, Lance L.; Padera, Timothy P.

    2014-01-01

    Visualization of the lymphatic system is clinically necessary during diagnosis or treatment of many conditions and diseases; it is used for identifying and monitoring lymphedema, for detecting metastatic lesions during cancer staging and for locating lymphatic structures so they can be spared during surgical procedures. Imaging lymphatic anatomy and function also plays an important role in experimental studies of lymphatic development and function, where spatial resolution and accessibility are better. Here, we review technologies for visualizing and imaging the lymphatic system for clinical applications. We then describe the use of lymphatic imaging in experimental systems as well as some of the emerging technologies for improving these methodologies. PMID:24956510

  7. How Do Meningeal Lymphatic Vessels Drain the CNS?

    PubMed

    Raper, Daniel; Louveau, Antoine; Kipnis, Jonathan

    2016-09-01

    The many interactions between the nervous and the immune systems, which are active in both physiological and pathological states, have recently become more clearly delineated with the discovery of a meningeal lymphatic system capable of carrying fluid, immune cells, and macromolecules from the central nervous system (CNS) to the draining deep cervical lymph nodes. However, the exact localization of the meningeal lymphatic vasculature and the path of drainage from the cerebrospinal fluid (CSF) to the lymphatics remain poorly understood. Here, we discuss the potential differences between peripheral and CNS lymphatic vessels and examine the purported mechanisms of CNS lymphatic drainage, along with how these may fit into established patterns of CSF flow.

  8. Short time effects of radiotherapy on lymphatic vessels and restorative lymphatic pathways: experimental approaches ina mouse model.

    PubMed

    Pastouret, F; Lievens, P; Leduc, O; Bourgeois, P; Tournel, K; Lamote, J; Zirak, C; Leduc, A

    2014-06-01

    Radiotherapy (RT) is an important component in the therapeutic approach to oncologic conditions. This study presents the investigative results on the impact of RT on lymphatic vessels and on the regenerative response of the lymphatic system in a mouse model. We first irradiated 3 groups of ten mice using brachytherapy in a single treatment of 20 Gy. We then performed morphological examination of the irradiated lymphatic vessels using an in vivo microscopic transillumination technique at 2, 4, and 6 weeks. Next we evaluated lymphatic flow using lymphoscintigraphy and in vivo microscopy at 6 to 11 weeks in: 10 additional mice following irradiation as above (IR), in 10 mice following incision of a lymphatic vessel (I), and in a non-treated control group of 10 mice (N). Intact lymphatic vessels were observed in all mice at 2, 4, and 8 weeks following the single dose of radiotherapy in the first group of mice and normal lymphatic flow was fully restored in the irradiated (IR) and incised (I) mice indicating that the reparative substitution lymphatic pathways are functioning normally. We found that following irradiation with one dose of 20 Gy, lymphatic vessels were not visibly damaged and also that lymphatic flow was consistently restored and substitutive lymphatic pathways formed.

  9. Lymphatic anatomy and biomechanics.

    PubMed

    Negrini, Daniela; Moriondo, Andrea

    2011-06-15

    Lymph formation is driven by hydraulic pressure gradients developing between the interstitial tissue and the lumen of initial lymphatics. While in vessels equipped with lymphatic smooth muscle cells these gradients are determined by well-synchronized spontaneous contractions of vessel segments, initial lymphatics devoid of smooth muscles rely on tissue motion to form lymph and propel it along the network. Lymphatics supplying highly moving tissues, such as skeletal muscle, diaphragm or thoracic tissues, undergo cyclic compression and expansion of their lumen imposed by local stresses arising in the tissue as a consequence of cardiac and respiratory activities. Active muscle contraction and not passive tissue displacement is required to support an efficient lymphatic drainage, as suggested by the fact that the respiratory activity promotes lymph formation during spontaneous, but not mechanical ventilation. The mechanical properties of the lymphatic wall and of the surrounding tissue also play an important role in lymphatic function. Modelling of stress distribution in the lymphatic wall suggests that compliant vessels behave as reservoirs accommodating absorbed interstitial fluid, while lymphatics with stiffer walls, taking advantage of a more efficient transmission of tissue stresses to the lymphatic lumen, propel fluid through the lumen of the lymphatic circuit.

  10. Near infrared lymphatic imaging demonstrates the dynamics of lymph flow and lymphangiogenesis during the acute vs. chronic phases of arthritis in mice

    PubMed Central

    Zhou, Quan; Wood, Ronald; Schwarz, Edward M.; Wang, Yong-Jun; Xing, Lianping

    2010-01-01

    Objective Development of an in vivo imaging method to assess lymphatic draining function in the K/B×N mouse model of inflammatory arthritis. Methods Indocyanine green (ICG), a near-infrared (NIR) fluorescent dye, was injected intradermally into the footpad of wild-type mice, the limb was illuminated with an 806 nm NIR laser, and the movement of ICG from the injection site to the draining popliteal lymph node (PLN) was recorded with a CCD camera. ICG-NIR images were analyzed to obtain 5 measures of lymphatic function across time. K/B×N arthritic mice and control non-arthritic littermates were imaged at one-month of age when acute joint inflammation commenced, and repeated at 3 months when joint inflammation became chronic. Lymphangiogenesis in PLNs was assessed by immunochemistry. Results ICG and its transport within lymphatic vessels were readily visualized and quantitative measures derived. During the acute phase of arthritis, the lymphatic vessels were dilated with increased ICG signal intensity and lymphatic pulses, and PLNs became fluorescent quickly. During the chronic phase, new lymphatic vessels were present near the foot. However, ICG appearance in lymphatic vessels was delayed. The size and area of PLN lymphatic sinuses progressively increased in the K/B×N mice. Conclusion ICG-NIR lymphatic imaging is a valuable method to assess the lymphatic draining function in mice with inflammatory arthritis. ICG-NIR imaging of K/B×N mice identified two distinct lymphatic phenotypes during the acute and chronic phase of inflammation. This technique can be used to assess new therapies for lymphatic disorders. PMID:20309866

  11. Lymphatics, Cancer and Zebrafish.

    PubMed

    Astin, Jonathan W; Crosier, Philip S

    2016-01-01

    Many solid tumors are known to metastasize through the lymphatic vasculature. This process is facilitated by the generation of new lymphatic vessels (tumor lymphangiogenesis) and also by the remodelling of existing lymphatics. Together these processes enable the spread of tumor cells to distant sites. Currently our understanding of tumor lymphangiogenesis has been informed from mouse tumor models and from studies of developmental lymphangiogenesis. Since the discovery of bona fide lymphatic vessels in zebrafish in 2006, zebrafish have become a well-established model of developmental lymphangiogenesis. The attributes that make zebrafish such an important model of blood vessel development-the ability to live image developing vessels, genetic tractability and the conserved nature of development-also make fish an attractive model of lymphatic vessel development. In particular, zebrafish have made important contributions to our understanding of the processes of lymphatic vessel sprouting from veins and the mechanisms by which lymphatic precursors remodel into mature vessels. To date, zebrafish have not been used to directly model tumor lymphangiogenesis. In this chapter we will summarise the contributions zebrafish have made to our understanding of lymphangiogenesis and investigate the possibilities of combining zebrafish transgenic cancer lines or tumor transplantation models with existing lymphatic reporter lines, which could provide valuable insights into the process of tumor-induced lymphangiogenesis. In addition the utility of using the zebrafish lymphatic model as a platform to screen and develop novel anti-lymphatic therapeutics will also be discussed.

  12. Lymphatics, Cancer and Zebrafish.

    PubMed

    Astin, Jonathan W; Crosier, Philip S

    2016-01-01

    Many solid tumors are known to metastasize through the lymphatic vasculature. This process is facilitated by the generation of new lymphatic vessels (tumor lymphangiogenesis) and also by the remodelling of existing lymphatics. Together these processes enable the spread of tumor cells to distant sites. Currently our understanding of tumor lymphangiogenesis has been informed from mouse tumor models and from studies of developmental lymphangiogenesis. Since the discovery of bona fide lymphatic vessels in zebrafish in 2006, zebrafish have become a well-established model of developmental lymphangiogenesis. The attributes that make zebrafish such an important model of blood vessel development-the ability to live image developing vessels, genetic tractability and the conserved nature of development-also make fish an attractive model of lymphatic vessel development. In particular, zebrafish have made important contributions to our understanding of the processes of lymphatic vessel sprouting from veins and the mechanisms by which lymphatic precursors remodel into mature vessels. To date, zebrafish have not been used to directly model tumor lymphangiogenesis. In this chapter we will summarise the contributions zebrafish have made to our understanding of lymphangiogenesis and investigate the possibilities of combining zebrafish transgenic cancer lines or tumor transplantation models with existing lymphatic reporter lines, which could provide valuable insights into the process of tumor-induced lymphangiogenesis. In addition the utility of using the zebrafish lymphatic model as a platform to screen and develop novel anti-lymphatic therapeutics will also be discussed. PMID:27165355

  13. Lymphatic Pump Treatment Increases Thoracic Duct Lymph Flow in Conscious Dogs with Edema Due to Constriction of the Inferior Vena Cava

    PubMed Central

    Prajapati, Parna; Shah, Pankhil; King, Hollis H.; Williams, Arthur G.; Desai, Pratikkumar

    2010-01-01

    Abstract Background Osteopathic lymphatic pump treatments (LPT) are used to treat edema, but their direct effects on lymph flow have not been studied. In the current study, we examined the effects of LPT on lymph flow in the thoracic duct of instrumented conscious dogs in the presence of edema produced by constriction of the inferior vena cava (IVC). Methods and Results Six dogs were surgically instrumented with an ultrasonic flow transducer on the thoracic lymph duct and catheters in the descending thoracic aorta and in IVC. After postoperative recovery, lymph flow and hemodynamic variables were measured 1) pre-LPT, 2) during 4 min LPT, 3) post-LPT, in the absence and presence of edema produced by IVC constriction. This constriction increased abdominal girth from 60 ± 2.6 to 75 ± 2.9 cm. Before IVC constriction, LPT increased lymph flow (P < 0.05) from 1.9 ± 0.2 ml/min to a maximum of 4.7 ± 1.2 ml/min, whereas after IVC constriction, LPT increased lymph flow (P < 0.05) from 7.9 ± 2.2 to a maximum of 11.7 ± 2.2 ml/min. The incremental lymph flow mobilized by 4 min of LPT (ie, the flow that exceeded 4 min of baseline flow), was 10.6 ml after IVC constriction. This incremental flow was not significantly greater than that measured before IVC constriction. Conclusions Edema caused by IVC constriction markedly increased lymph flow in the thoracic duct. LPT increased thoracic duct lymph flow before and after IVC constriction. The lymph flow mobilized by 4 min of LPT in presence of edema was not significantly greater than that mobilized prior to edema. PMID:20863267

  14. Near-Infrared Fluorescence Lymphatic Imaging to Reconsider Occlusion Pressure of Superficial Lymphatic Collectors in Upper Extremities of Healthy Volunteers

    PubMed Central

    Vandermeeren, Liesbeth; Vankerckhove, Sophie; Valsamis, Jean-Baptiste; Malloizel-Delaunay, Julie; Moraine, Jean-Jacques; Liebens, Fabienne

    2016-01-01

    Abstract Background: There are very little scientific data on occlusion pressure for superficial lymphatic collectors. Given its importance in determining the transport capacity of lymphatic vessels, it is crucial to know its value. The novel method of near-infrared fluorescence lymphatic imaging (NIRFLI) can be used to visualize lymphatic flow in real time. The goal of this study was to see if this method could be used to measure the lymphatic occlusion pressure. Methods: We observed and recorded lymph flow in the upper limb of healthy volunteers through a transparent cuff using near-infrared fluorescence lymphatic imaging. After obtaining a baseline of the lymph flow without pressure inside the cuff, the cuff was inflated by increments of 10 mm Hg starting at 30 mm Hg. A NIRFLI guided manual lymphatic drainage technique named “Fill & Flush Drainage Method” was performed during the measurement to promote lymph flow. Lymphatic occlusion pressure was determined by observing when lymph flow stopped under the cuff. Results: We measured the lymphatic occlusion pressure on 30 healthy volunteers (11 men and 19 women). Mean lymphatic occlusion pressure in the upper limb was 86 mm Hg (CI ±3.7 mm Hg, α = 0.5%). No significant differences were found between age groups (p = 0.18), gender (p = 0.12), or limb side (p = 0.85). Conclusions: NIRFLI, a transparent sphygmomanometer cuff and the “Fill and Flush” manual lymphatic drainage method were used to measure the lymphatic occlusion pressure in 30 healthy humans. That combination of these techniques allows the visualization of the lymph flow in real time, while ensuring the continuous filling of the lymph collectors during the measurement session, reducing false negative observations. The measured occlusion pressures are much higher than previously described in the medical literature. PMID:27167187

  15. In vivo quantification of lymph viscosity and pressure in lymphatic vessels and draining lymph nodes of arthritic joints in mice

    PubMed Central

    Bouta, Echoe M; Wood, Ronald W; Brown, Edward B; Rahimi, Homaira; Ritchlin, Christopher T; Schwarz, Edward M

    2014-01-01

    Rheumatoid arthritis (RA) is a chronic inflammatory joint disease with episodic flares. In TNF-Tg mice, a model of inflammatory–erosive arthritis, the popliteal lymph node (PLN) enlarges during the pre-arthritic ‘expanding’ phase, and then ‘collapses’ with adjacent knee flare associated with the loss of the intrinsic lymphatic pulse. As the mechanisms responsible are unknown, we developed in vivo methods to quantify lymph viscosity and pressure in mice with wild-type (WT), expanding and collapsed PLN. While no differences in viscosity were detected via multiphoton fluorescence recovery after photobleaching (MP-FRAP) of injected FITC-BSA, a 32.6% decrease in lymph speed was observed in vessels afferent to collapsed PLN (P < 0.05). Direct measurement of intra-lymph node pressure (LNP) demonstrated a decrease in expanding PLN versus WT pressure (3.41 ± 0.43 vs. 6.86 ± 0.56 cmH2O; P < 0.01), which dramatically increased to 9.92 ± 1.79 cmH2O in collapsed PLN. Lymphatic pumping pressure (LPP), measured indirectly by slowly releasing a pressurized cuff occluding indocyanine green (ICG), demonstrated an increase in vessels afferent to expanding PLN versus WT (18.76 ± 2.34 vs. 11.04 ± 1.47 cmH2O; P < 0.01), which dropped to 2.61 ± 0.72 cmH2O (P < 0.001) after PLN collapse. Herein, we document the first in vivo measurements of murine lymph viscosity and lymphatic pressure, and provide evidence to support the hypothesis that lymphangiogenesis and lymphatic transport are compensatory mechanisms to prevent synovitis via increased drainage of inflamed joints. Furthermore, the decrease in lymphatic flow and loss of LPP during PLN collapse are consistent with decreased drainage from the joint during arthritic flare, and validate these biomarkers of RA progression and possibly other chronic inflammatory conditions. PMID:24421350

  16. Primary afferent depolarization and frequency processing in auditory afferents.

    PubMed

    Baden, Tom; Hedwig, Berthold

    2010-11-01

    Presynaptic inhibition is a widespread mechanism modulating the efficiency of synaptic transmission and in sensory pathways is coupled to primary afferent depolarizations. Axonal terminals of bush-cricket auditory afferents received 2-5 mV graded depolarizing inputs, which reduced the amplitude of invading spikes and indicated presynaptic inhibition. These inputs were linked to a picrotoxin-sensitive increase of Ca(2+) in the terminals. Electrophysiological recordings and optical imaging showed that in individual afferents the sound frequency tuning based on spike rates was different from the tuning of the graded primary afferent depolarizations. The auditory neuropil of the bush-cricket Mecopoda elongata is tonotopically organized, with low frequencies represented anteriorly and high frequencies represented posteriorly. In contrast graded depolarizing inputs were tuned to high-frequencies anteriorly and to low-frequencies posteriorly. Furthermore anterior and posterior axonal branches of individual afferents received different levels of primary afferent depolarization depending on sound frequency. The presence of primary afferent depolarization in the afferent terminals indicates that presynaptic inhibition may shape the synaptic transmission of frequency-specific activity to auditory interneurons.

  17. Lymph transport in rat mesenteric lymphatics experiencing edemagenic stress

    PubMed Central

    Rahbar, Elaheh; Akl, Tony; Coté, Gerard L.; Moore, James E.; Zawieja, David C.

    2014-01-01

    Objective To assess lymphatic flow adaptations to edema, we evaluated lymph transport function in rat mesenteric lymphatics under normal and edemagenic conditions in situ. Methods Twelve rats were infused with saline (intravenous infusion, 0.2 ml/min/100g body weight) to induce edema. We intravitally measured mesenteric lymphatic diameter and contraction frequency, as well as immune cell velocity and density before, during and after infusion. Results A 10-fold increase in lymph velocity (0.1–1 mm/s) and a 6-fold increase in flow rate (0.1–0.6 μL/min), were observed post-infusion, respectively. There were also increases in contraction frequency and fractional pump flow 1-minute post-infusion. Time-averaged wall shear stress increased 10 fold post-infusion to nearly 1.5 dynes/cm2. Similarly, maximum shear stress rose from 5 dynes/cm2 to 40 dynes/cm2. Conclusions Lymphatic vessels adapted to edemagenic stress by increasing lymph transport. Specifically, the increases in lymphatic contraction frequency, lymph velocity, and shear stress were significant. Lymph pumping increased post-infusion, though changes in lymphatic diameter were not statistically significant. These results indicate that edemagenic conditions stimulate lymph transport via increases in lymphatic contraction frequency, lymph velocity and flow. These changes, consequently, resulted in large increases in wall shear stress, which could then activate NO pathways and modulate lymphatic transport function. PMID:24397756

  18. Quantitative imaging of lymphatic function with liposomal indocyanine green.

    PubMed

    Proulx, Steven T; Luciani, Paola; Derzsi, Stefanie; Rinderknecht, Matthias; Mumprecht, Viviane; Leroux, Jean-Christophe; Detmar, Michael

    2010-09-15

    Lymphatic vessels play a major role in cancer progression and in postsurgical lymphedema, and several new therapeutic approaches targeting lymphatics are currently being developed. Thus, there is a critical need for quantitative imaging methods to measure lymphatic flow. Indocyanine green (ICG) has been used for optical imaging of the lymphatic system, but it is unstable in solution and may rapidly enter venous capillaries after local injection. We developed a novel liposomal formulation of ICG (LP-ICG), resulting in vastly improved stability in solution and an increased fluorescence signal with a shift toward longer wavelength absorption and emission. When injected intradermally to mice, LP-ICG was specifically taken up by lymphatic vessels and allowed improved visualization of deep lymph nodes. In a genetic mouse model of lymphatic dysfunction, injection of LP-ICG showed no enhancement of draining lymph nodes and slower clearance from the injection site. In mice bearing B16 luciferase-expressing melanomas expressing vascular endothelial growth factor-C (VEGF-C), sequential near-IR imaging of intradermally injected LP-ICG enabled quantification of lymphatic flow. Increased flow through draining lymph nodes was observed in mice bearing VEGF-C-expressing tumors without metastases, whereas a decreased flow pattern was seen in mice with a higher lymph node tumor burden. This new method will likely facilitate quantitative studies of lymphatic function in preclinical investigations and may also have potential for imaging of lymphedema or improved sentinel lymph detection in cancer. PMID:20823159

  19. Transcriptional profile in afferent lymph cells following vaccination with liposomes incorporating CpG

    PubMed Central

    Neeland, Melanie R; Elhay, Martin J; Powell, David R; Rossello, Fernando J; Meeusen, Els N T; de Veer, Michael J

    2015-01-01

    Vaccine formulations incorporating innate immune stimulants are highly immunogenic; however, the biological signals that originate in the peripheral tissues at the site of injection and are transmitted to the local lymph node to induce immunity remain unclear. By directly cannulating the ovine afferent lymphatic vessels, we have previously shown that it takes 72 hr for mature antigen-loaded dendritic cells and monocytes to appear within afferent lymph following injection of a liposomal formulation containing the Toll-like receptor ligand CpG. In this present study, we characterize the global transcriptional signatures at this time-point in ovine afferent lymph cells as they migrate from the injection site into the lymphatics following vaccination with a liposome antigen formulation incorporating CpG. We show that at 72 hr post vaccination, liposomes alone induce no changes in gene expression and inflammatory profiles within afferent lymph; however, the incorporation of CpG drives interferon, antiviral and cytotoxic gene programmes. This study also measures the expression of key genes within individual cell types in afferent lymph. Antiviral gene signatures are most prominent in lymphocytes, which may play a significant and unexpected role in sustaining the immune response to vaccination at the site of injection. These findings provide a comprehensive analysis of the in vivo immunological pathways that connect the injection site with the local draining lymph node following vaccination. PMID:25308816

  20. Tie1 is required for lymphatic valve and collecting vessel development

    PubMed Central

    Qu, Xianghu; Zhou, Bin; Baldwin, H. Scott

    2015-01-01

    Tie1 is a receptor tyrosine kinase with broad expression in embryonic endothelium. Reduction of Tie1 levels in mouse embryos with a hypomorphic Tie1 allele resulted in abnormal lymphatic patterning and architecture, decreased lymphatic draining efficiency, and ultimately, embryonic demise. Here we report that Tie1 is present uniformly throughout the lymphatics and from late embryonic/early postnatal stages, becomes more restricted to lymphatic valve regions. To investigate later events of lymphatic development, we employed Cre-loxP recombination utilizing a floxed Tie1 allele and an Nfatc1Cre line, to provide loxP excision predominantly in lymphatic endothelium and developing valves. Interestingly, unlike the early prenatal defects previously described by ubiquitous endothelial deletion, excision of Tie1 with Nfatc1Cre resulted in abnormal lymphatic defects in postnatal mice and was characterized by agenesis of lymphatic valves and a deficiency of collecting lymphatic vessels. Attenuation of Tie1 signaling in lymphatic endothelium prevented initiation of lymphatic valve specification by Prox1 high expression lymphatic endothelial cells that is associated with the onset of turbulent flow in the lymphatic circulation. Our findings reveal a fundamental role for Tie signaling during lymphatic vessel remodeling and valve morphogenesis and implicate it as a candidate gene involved in primary lymphedema. PMID:25576926

  1. Mechanisms of VIP-induced inhibition of the lymphatic vessel pump.

    PubMed

    von der Weid, Pierre-Yves; Rehal, Sonia; Dyrda, Peter; Lee, Stewart; Mathias, Ryan; Rahman, Mozibur; Roizes, Simon; Imtiaz, Mohammad S

    2012-06-01

    Lymphatic vessels serve as a route by which interstitial fluid, protein and other macromolecules are returned to the blood circulation and immune cells and antigens gain access to lymph nodes. Lymph flow is an active process promoted by rhythmical contraction-relaxation events occurring in the collecting lymphatic vessels. This lymphatic pumping is an intrinsic property of the lymphatic muscles in the vessel wall and consequent to action potentials. Compromised lymphatic pumping may affect lymph and immune cell transport, an action which could be particularly detrimental during inflammation. Importantly, many inflammatory mediators alter lymphatic pumping. Vasoactive intestinal peptide (VIP) is a neuro- and immuno-modulator thought to be released by nerve terminals and immune cells in close proximity to lymphatic vessels. We demonstrated the presence of the peptide in lymphatic vessels and in the lymph and examined the effects of VIP on mesenteric collecting lymphatic vessels of the guinea pig using pharmacological bioassays, intracellular microelectrode electrophysiology, immunofluorescence and quantitative real-time PCR. We showed that VIP alters lymphatic pumping by decreasing the frequency of lymphatic contractions and hyperpolarizing the lymphatic muscle membrane potential in a concentration-dependent manner. Our data further suggest that these effects are mainly mediated by stimulation of the VIP receptor VPAC2 located on the lymphatic muscle and the downstream involvement of protein kinase A (PKA) and ATP-sensitive K⁺ (KATP) channels. Inhibition of lymphatic pumping by VIP may compromise lymph drainage, oedema resolution and immune cell trafficking to the draining lymph nodes.

  2. Tie1 is required for lymphatic valve and collecting vessel development.

    PubMed

    Qu, Xianghu; Zhou, Bin; Scott Baldwin, H

    2015-03-01

    Tie1 is a receptor tyrosine kinase with broad expression in embryonic endothelium. Reduction of Tie1 levels in mouse embryos with a hypomorphic Tie1 allele resulted in abnormal lymphatic patterning and architecture, decreased lymphatic draining efficiency, and ultimately, embryonic demise. Here we report that Tie1 is present uniformly throughout the lymphatics and from late embryonic/early postnatal stages, becomes more restricted to lymphatic valve regions. To investigate later events of lymphatic development, we employed Cre-loxP recombination utilizing a floxed Tie1 allele and an Nfatc1Cre line, to provide loxP excision predominantly in lymphatic endothelium and developing valves. Interestingly, unlike the early prenatal defects previously described by ubiquitous endothelial deletion, excision of Tie1 with Nfatc1Cre resulted in abnormal lymphatic defects in postnatal mice and was characterized by agenesis of lymphatic valves and a deficiency of collecting lymphatic vessels. Attenuation of Tie1 signaling in lymphatic endothelium prevented initiation of lymphatic valve specification by Prox1 high expression lymphatic endothelial cells that is associated with the onset of turbulent flow in the lymphatic circulation. Our findings reveal a fundamental role for Tie1 signaling during lymphatic vessel remodeling and valve morphogenesis and implicate it as a candidate gene involved in primary lymphedema.

  3. Stress-driven lymphatic dissemination: An unanticipated consequence of communication between the sympathetic nervous system and lymphatic vasculature.

    PubMed

    Le, Caroline P; Sloan, Erica K

    2016-07-01

    Chronic stress drives cancer progression, but the routes of metastasis are unclear. We recently demonstrated that chronic stress activates a neural-inflammatory signaling axis to remodel lymphatic vasculature and increase lymph flow. This unanticipated crosstalk between stress and the lymphatic system provides pathways of tumor cell dissemination and accelerates metastasis. PMID:27652324

  4. Lymphatics and the breast

    MedlinePlus

    ... is often referred to as the body's "secondary circulatory system." The lymphatic system collects excess fluid in ... the exchange of fluid and molecules between the blood circulation and body tissues, blood capillaries may not reabsorb ...

  5. Lymphatic Muscle Cells in Rat Mesenteric Lymphatic Vessels of Various Ages

    PubMed Central

    Bridenbaugh, Eric A.; Nizamutdinova, Irina Tsoy; Jupiter, Daniel; Nagai, Takashi; Thangaswamy, Sangeetha; Chatterjee, Victor

    2013-01-01

    Abstract Background Recent studies on aging-associated changes in mesenteric lymph flow in situ demonstrated predominance of the severe negative chronotropic effect of aging on the contractility of aged mesenteric lymphatic vessels (MLV). At the same time, contraction amplitude of the aged vessels was only slightly diminished by aging and can be rapidly stimulated within 5–15 minutes. However, the detailed quantitative evaluation of potential aging-associated changes in muscle cells investiture in MLV has never been performed. Methods and Results In this study we, for the first time, performed detailed evaluation of muscle cells investiture in MLV in reference to the position of lymphatic valve in different zones of lymphangion within various age groups (3-mo, 9-mo and 24-mo Fischer-344 rats). Using visual and quantitative analyses of the images of MLV immunohistochemically labeled for actin, we confirmed that the zones located close upstream (pre-valve zones) and above lymphatic valves (valve zones) possess the lowest investiture of lymphatic muscle cells. Most of the high muscle cells investiture zones exist downstream to the lymphatic valve (post-valve zones). The muscle cells investiture of these zones is not affected by aging, while pre-valve and valve zones demonstrate significant aging-associated decrease in muscle cells investiture. Conclusions The low muscle cells investiture zones in lymphatic vessels consist of predominantly longitudinally oriented muscle cells which are positioned in pre-valve and valve zones and connect adjacent lymphangions. These cells may provide important functional impact on the biomechanics of the lymphatic valve gating and electrical coupling between lymphangions, while their aging-associated changes may delimit adaptive reserves of aged lymphatic vessels. PMID:23531183

  6. Osteopathic lymphatic pump techniques to enhance immunity and treat pneumonia

    PubMed Central

    Hodge, Lisa M.

    2012-01-01

    Pneumonia is a common cause of morbidity and mortality worldwide. While antibiotics are generally effective for the treatment of infection, the emergence of resistant strains of bacteria threatens their success. The osteopathic medical profession has designed a set of manipulative techniques called lymphatic pump techniques (LPT), to enhance the flow of lymph through the lymphatic system. Clinically, LPT is used to treat infection and oedemaand might be an effective adjuvant therapy in patients with pneumonia.The immune system uses the lymphatic and blood systems to survey to rid the body of pathogens; however, only recently have the effects of LPT on the lymphatic and immune systems been investigated. This short review highlightsclinical and basic science research studies that support the use of LPT to enhance the lymphatic and immune systems and treat pneumonia, and discusses the potential mechanisms by which LPT benefits patients with pneumonia. PMID:22977459

  7. How Do Meningeal Lymphatic Vessels Drain the CNS?

    PubMed

    Raper, Daniel; Louveau, Antoine; Kipnis, Jonathan

    2016-09-01

    The many interactions between the nervous and the immune systems, which are active in both physiological and pathological states, have recently become more clearly delineated with the discovery of a meningeal lymphatic system capable of carrying fluid, immune cells, and macromolecules from the central nervous system (CNS) to the draining deep cervical lymph nodes. However, the exact localization of the meningeal lymphatic vasculature and the path of drainage from the cerebrospinal fluid (CSF) to the lymphatics remain poorly understood. Here, we discuss the potential differences between peripheral and CNS lymphatic vessels and examine the purported mechanisms of CNS lymphatic drainage, along with how these may fit into established patterns of CSF flow. PMID:27460561

  8. [Medical treatment of lymphatic filariasis].

    PubMed

    Hovette, P; Laroche, R; Verrot, D; Molinier, S; Touze, J E

    1991-01-01

    Lymphatic filariasis remains in 1991 a major health problem. Ivermectine revolutionizes their treatment and, by suppressing microfilaremia, provides a new method of helping to control the vector-borne transmission of lymphatic filariasis. PMID:2072855

  9. Communication between lymphatic and venous systems in mice.

    PubMed

    Shao, Lenan; Takeda, Kazu; Kato, Shigeki; Mori, Shiro; Kodama, Tetsuya

    2015-09-01

    The lymphatic system in mice consists of lymphatic vessels and 22 types of lymph nodes. Metastatic tumor cells in the lymphatic system spread to distant organs through the venous system. However, the communication routes between the lymphatic and venous systems have not been fully elucidated. Here, we identify the communication routes between the lymphatic and venous systems in the axillary and subiliac regions of MXH10/Mo-lpr/lpr inbred mice, which develop systemic swelling of lymph nodes up to 10mm in diameter, allowing investigation of the topography of the lymph nodes and lymphatic vessels. Using a gross anatomy dissection approach, the efferent lymphatic vessels of the proper axillary lymph node were shown to communicate with the subclavian vein. Furthermore, we found that the thoracoepigastric vein, which connects the subclavian vein and inferior vena cava, runs adjacent to the subiliac and proper axillary lymph nodes, and receives venous blood from these lymph nodes routed through small branches. The direction of blood flow in the thoracoepigastric vein occurred in two directions in the intermediate region between the proper axillary lymph node and subiliac lymph node; one to the subclavian vein, the other to the inferior vena cava. This paper reveals the anatomy of the communication between the lymphatic and venous systems in the axillary and subiliac regions of the mouse, and provides new insights relevant to the investigation of the mechanisms of lymph node metastasis and cancer immunology, and the development of diagnostic and treatment methods for lymph node metastasis, including drug delivery systems.

  10. Exploring local immune responses to vaccines using efferent lymphatic cannulation.

    PubMed

    Mahakapuge, Thilini An; Every, Alison L; Scheerlinck, Jean-Pierre Y

    2015-04-01

    The early stages of the induction of a primary immune response to a vaccine can shape the overall quality of the immune memory generated and hence affect the success of the vaccine. This early interaction between a vaccine and the immune system occurs first at the site of vaccination and can be explored using afferent cannulation. Subsequently, the vaccine and adjuvant activates the local draining lymph node. These interactions can be studied in real time in vivo using efferent lymphatic duct cannulation in large animal models and are the subject of this review. Depending on how the vaccine is delivered, the draining lymph nodes of different organs can be accessed, facilitating the testing of tissue-specific vaccinations. The efferent lymphatic cannulation model provides an avenue to study the effect of both adjuvants and antigen on the local immune system, and hence opens a pathway toward developing more effective ways of inducing immunity.

  11. Itching for answers: how histamine relaxes lymphatic vessels.

    PubMed

    Scallan, Joshua P; Davis, Michael J

    2014-10-01

    In the current issue of Microcirculation, studies by Kurtz et al. and Nizamutdinova et al. together provide new evidence supporting a role for histamine as an endothelial-derived molecule that inhibits lymphatic muscle contraction. In particular, Nizamutdinova et al. show that the effects of flow-induced shear stress on lymphatic endothelium are mediated by both nitric oxide and histamine, since only blockade of both prevents contraction strength and frequency from being altered by flow. Separately, Kurtz et al. used confocal microscopy to determine a preferential expression of histamine receptors on the lymphatic endothelium and demonstrated that histamine applied to spontaneously contracting collecting lymphatics inhibits contractions. Previous studies disagreed on whether histamine stimulates or inhibits lymphatic contractions, but also used differing concentrations, species, and preparations. Together these new reports shed light on how histamine acts within the lymphatic vasculature, but also raise important questions about the cell type on which histamine exerts its effects and the signaling pathways involved. This editorial briefly discusses the contribution of each study and its relevance to lymphatic biology.

  12. Molecular and functional analyses of the contractile apparatus in lymphatic muscle

    NASA Technical Reports Server (NTRS)

    Muthuchamy, Mariappan; Gashev, Anatoliy; Boswell, Niven; Dawson, Nancy; Zawieja, David; Delp, Z. (Principal Investigator)

    2003-01-01

    Lymphatics are necessary for the generation and regulation of lymph flow. Lymphatics use phasic contractions and extrinsic compressions to generate flow; tonic contractions alter resistance. Lymphatic muscle exhibits important differences from typical vascular smooth muscle. In this study, the thoracic duct exhibited significant functional differences from mesenteric lymphatics. To understand the molecular basis for these differences, we examined the profiles of contractile proteins and their messages in mesenteric lymphatics, thoracic duct, and arterioles. Results demonstrated that mesenteric lymphatics express only SMB smooth muscle myosin heavy chain (SM-MHC), whereas thoracic duct and arterioles expressed both SMA and SMB isoforms. Both SM1 and SM2 isoforms of SM-MHC were detected in arterioles and mesenteric and thoracic lymphatics. In addition, the fetal cardiac/skeletal slow-twitch muscle-specific beta-MHC message was detected only in mesenteric lymphatics. All four actin messages, cardiac alpha-actin, vascular alpha-actin, enteric gamma-actin, and skeletal alpha-actin, were present in both mesenteric lymphatics and arterioles. However, in thoracic duct, predominantly cardiac alpha-actin and vascular alpha-actin were found. Western blot and immunohistochemical analyses corroborated the mRNA studies. However, in arterioles only vascular alpha-actin protein was detected. These data indicate that lymphatics display genotypic and phenotypic characteristics of vascular, cardiac, and visceral myocytes, which are needed to fulfill the unique roles of the lymphatic system.

  13. Lipopolysaccharide modulates neutrophil recruitment and macrophage polarization on lymphatic vessels and impairs lymphatic function in rat mesentery.

    PubMed

    Chakraborty, Sanjukta; Zawieja, Scott D; Wang, Wei; Lee, Yang; Wang, Yuan J; von der Weid, Pierre-Yves; Zawieja, David C; Muthuchamy, Mariappan

    2015-12-15

    Impairment of the lymphatic system is apparent in multiple inflammatory pathologies connected to elevated endotoxins such as LPS. However, the direct mechanisms by which LPS influences the lymphatic contractility are not well understood. We hypothesized that a dynamic modulation of innate immune cell populations in mesentery under inflammatory conditions perturbs tissue cytokine/chemokine homeostasis and subsequently influences lymphatic function. We used rats that were intraperitoneally injected with LPS (10 mg/kg) to determine the changes in the profiles of innate immune cells in the mesentery and in the stretch-mediated contractile responses of isolated lymphatic preparations. Results demonstrated a reduction in the phasic contractile activity of mesenteric lymphatic vessels from LPS-injected rats and a severe impairment of lymphatic pump function and flow. There was a significant reduction in the number of neutrophils and an increase in monocytes/macrophages present on the lymphatic vessels and in the clear mesentery of the LPS group. This population of monocytes and macrophages established a robust M2 phenotype, with the majority showing high expression of CD163 and CD206. Several cytokines and chemoattractants for neutrophils and macrophages were significantly changed in the mesentery of LPS-injected rats. Treatment of lymphatic muscle cells (LMCs) with LPS showed significant changes in the expression of adhesion molecules, VCAM1, ICAM1, CXCR2, and galectin-9. LPS-TLR4-mediated regulation of pAKT, pERK pI-κB, and pMLC20 in LMCs promoted both contractile and inflammatory pathways. Thus, our data provide the first evidence connecting the dynamic changes in innate immune cells on or near the lymphatics and complex cytokine milieu during inflammation with lymphatic dysfunction.

  14. Primary and secondary lymphatic valve development: molecular, functional and mechanical insights.

    PubMed

    Bazigou, Eleni; Wilson, John T; Moore, James E

    2014-11-01

    Fluid homeostasis in vertebrates critically relies on the lymphatic system forming a hierarchical network of lymphatic capillaries and collecting lymphatics, for the efficient drainage and transport of extravasated fluid back to the cardiovascular system. Blind-ended lymphatic capillaries employ specialized junctions and anchoring filaments to encourage a unidirectional flow of the interstitial fluid into the initial lymphatic vessels, whereas collecting lymphatics are responsible for the active propulsion of the lymph to the venous circulation via the combined action of lymphatic muscle cells and intraluminal valves. Here we describe recent findings on molecular and physical factors regulating the development and maturation of these two types of valves and examine their role in tissue-fluid homeostasis.

  15. Gut vagal afferents differentially modulate innate anxiety and learned fear.

    PubMed

    Klarer, Melanie; Arnold, Myrtha; Günther, Lydia; Winter, Christine; Langhans, Wolfgang; Meyer, Urs

    2014-05-21

    Vagal afferents are an important neuronal component of the gut-brain axis allowing bottom-up information flow from the viscera to the CNS. In addition to its role in ingestive behavior, vagal afferent signaling has been implicated modulating mood and affect, including distinct forms of anxiety and fear. Here, we used a rat model of subdiaphragmatic vagal deafferentation (SDA), the most complete and selective vagal deafferentation method existing to date, to study the consequences of complete disconnection of abdominal vagal afferents on innate anxiety, conditioned fear, and neurochemical parameters in the limbic system. We found that compared with Sham controls, SDA rats consistently displayed reduced innate anxiety-like behavior in three procedures commonly used in preclinical rodent models of anxiety, namely the elevated plus maze test, open field test, and food neophobia test. On the other hand, SDA rats exhibited increased expression of auditory-cued fear conditioning, which specifically emerged as attenuated extinction of conditioned fear during the tone re-exposure test. The behavioral manifestations in SDA rats were associated with region-dependent changes in noradrenaline and GABA levels in key areas of the limbic system, but not with functional alterations in the hypothalamus-pituitary-adrenal grand stress. Our study demonstrates that innate anxiety and learned fear are both subjected to visceral modulation through abdominal vagal afferents, possibly via changing limbic neurotransmitter systems. These data add further weight to theories emphasizing an important role of afferent visceral signals in the regulation of emotional behavior.

  16. Modulation of the spontaneous contractions of the initial lymphatics of the bat's wing by arterial and venous occlusion.

    PubMed

    Unthank, J L; Hogan, R D

    1988-01-01

    The spontaneous contractions of the initial lymphatics of the bat's wing were observed to be modulated by changes in local blood flow. Lymphatic pressure and frequency of contraction were measured with the servo-null technique during the occlusion of the ulnar artery or vein. Lymphatic contractile activity was decreased during arterial occlusion but was increased during venous occlusion and postocclusion hyperemia. These changes in lymphatic activity are not consistent with the hypothesis that flow-associated changes in lymphatic contractile activity is mediated primarily by metabolic factors. PMID:3359051

  17. The lymphatic vasculature in disease.

    PubMed

    Alitalo, Kari

    2011-11-07

    Blood vessels form a closed circulatory system, whereas lymphatic vessels form a one-way conduit for tissue fluid and leukocytes. In most vertebrates, the main function of lymphatic vessels is to collect excess protein-rich fluid that has extravasated from blood vessels and transport it back into the blood circulation. Lymphatic vessels have an important immune surveillance function, as they import various antigens and activated antigen-presenting cells into the lymph nodes and export immune effector cells and humoral response factors into the blood circulation. Defects in lymphatic function can lead to lymph accumulation in tissues, dampened immune responses, connective tissue and fat accumulation, and tissue swelling known as lymphedema. This review highlights the most recent developments in lymphatic biology and how the lymphatic system contributes to the pathogenesis of various diseases involving immune and inflammatory responses and its role in disseminating tumor cells.

  18. Recent Advance in Lymph Dynamic Analysis in Lymphatics and Lymph Nodes

    PubMed Central

    2012-01-01

    Lymphatics are a unidirectional transport system that carries fluid from the interstitial space and back into the blood stream. Initial lymphatics take up not only fluid but also high-molecular-weight substances, such as plasma proteins and hyaluronan; immune cells, such as lymphocytes, macrophages, and dendritic cells; and colloidal particles, such as carbon particles, bacteria, and tattoo dye. Interstitially injected colloidal particles are known to accumulate in the regional lymph nodes. This phenomenon is applied to find sentinel lymph nodes in cancer patients. Lymph flow rate and composition are influenced by interstitial fluid, lymphatic pump activity, and intra-lymphatic pressure. Lymph composition is changed during its flow downstream. In this review, the main focus is on the mechanisms of lymph formation at the initial lymphatics and lymph transport through the collecting lymphatics and lymph nodes. (*English Translation of J Jpn Coll Angiol, 2008, 48: 113-123.) PMID:23555523

  19. Isolation and Characterization of Human Lung Lymphatic Endothelial Cells.

    PubMed

    Lorusso, Bruno; Falco, Angela; Madeddu, Denise; Frati, Caterina; Cavalli, Stefano; Graiani, Gallia; Gervasi, Andrea; Rinaldi, Laura; Lagrasta, Costanza; Maselli, Davide; Gnetti, Letizia; Silini, Enrico M; Quaini, Eugenio; Ampollini, Luca; Carbognani, Paolo; Quaini, Federico

    2015-01-01

    Characterization of lymphatic endothelial cells from the respiratory system may be crucial to investigate the role of the lymphatic system in the normal and diseased lung. We describe a simple and inexpensive method to harvest, isolate, and expand lymphatic endothelial cells from the human lung (HL-LECs). Fifty-five samples of healthy lung selected from patients undergoing lobectomy were studied. A two-step purification tool, based on paramagnetic sorting with monoclonal antibodies to CD31 and Podoplanin, was employed to select a pure population of HL-LECs. The purity of HL-LECs was assessed by morphologic criteria, immunocytochemistry, flow cytometry, and functional assays. Interestingly, these cells retain in vitro several receptor tyrosine kinases (RTKs) implicated in cell survival and proliferation. HL-LECs represent a clinically relevant cellular substrate to study lymphatic biology, lymphoangiogenesis, interaction with microbial agents, wound healing, and anticancer therapy. PMID:26137493

  20. Isolation and Characterization of Human Lung Lymphatic Endothelial Cells

    PubMed Central

    Lorusso, Bruno; Falco, Angela; Madeddu, Denise; Frati, Caterina; Cavalli, Stefano; Graiani, Gallia; Gervasi, Andrea; Rinaldi, Laura; Lagrasta, Costanza; Maselli, Davide; Gnetti, Letizia; Silini, Enrico M.; Quaini, Eugenio; Ampollini, Luca; Carbognani, Paolo; Quaini, Federico

    2015-01-01

    Characterization of lymphatic endothelial cells from the respiratory system may be crucial to investigate the role of the lymphatic system in the normal and diseased lung. We describe a simple and inexpensive method to harvest, isolate, and expand lymphatic endothelial cells from the human lung (HL-LECs). Fifty-five samples of healthy lung selected from patients undergoing lobectomy were studied. A two-step purification tool, based on paramagnetic sorting with monoclonal antibodies to CD31 and Podoplanin, was employed to select a pure population of HL-LECs. The purity of HL-LECs was assessed by morphologic criteria, immunocytochemistry, flow cytometry, and functional assays. Interestingly, these cells retain in vitro several receptor tyrosine kinases (RTKs) implicated in cell survival and proliferation. HL-LECs represent a clinically relevant cellular substrate to study lymphatic biology, lymphoangiogenesis, interaction with microbial agents, wound healing, and anticancer therapy. PMID:26137493

  1. Photoacoustic lymphatic imaging with high spatial-temporal resolution

    NASA Astrophysics Data System (ADS)

    Martel, Catherine; Yao, Junjie; Huang, Chih-Hsien; Zou, Jun; Randolph, Gwendalyn J.; Wang, Lihong V.

    2014-11-01

    Despite its critical function in coordinating the egress of inflammatory and immune cells out of tissues and maintaining fluid balance, the causative role of lymphatic network dysfunction in pathological settings is still understudied. Engineered-animal models and better noninvasive high spatial-temporal resolution imaging techniques in both preclinical and clinical studies will help to improve our understanding of different lymphatic-related pathologic disorders. Our aim was to take advantage of our newly optimized noninvasive wide-field fast-scanning photoacoustic (PA) microcopy system to coordinately image the lymphatic vasculature and its flow dynamics, while maintaining high resolution and detection sensitivity. Here, by combining the optical-resolution PA microscopy with a fast-scanning water-immersible microelectromechanical system scanning mirror, we have imaged the lymph dynamics over a large field-of-view, with high spatial resolution and advanced detection sensitivity. Depending on the application, lymphatic vessels (LV) were spectrally or temporally differentiated from blood vessels. Validation experiments were performed on phantoms and in vivo to identify the LV. Lymphatic flow dynamics in nonpathological and pathological conditions were also visualized. These results indicate that our newly developed PA microscopy is a promising tool for lymphatic-related biological research.

  2. FOXC2 and fluid shear stress stabilize postnatal lymphatic vasculature.

    PubMed

    Sabine, Amélie; Bovay, Esther; Demir, Cansaran Saygili; Kimura, Wataru; Jaquet, Muriel; Agalarov, Yan; Zangger, Nadine; Scallan, Joshua P; Graber, Werner; Gulpinar, Elgin; Kwak, Brenda R; Mäkinen, Taija; Martinez-Corral, Inés; Ortega, Sagrario; Delorenzi, Mauro; Kiefer, Friedemann; Davis, Michael J; Djonov, Valentin; Miura, Naoyuki; Petrova, Tatiana V

    2015-10-01

    Biomechanical forces, such as fluid shear stress, govern multiple aspects of endothelial cell biology. In blood vessels, disturbed flow is associated with vascular diseases, such as atherosclerosis, and promotes endothelial cell proliferation and apoptosis. Here, we identified an important role for disturbed flow in lymphatic vessels, in which it cooperates with the transcription factor FOXC2 to ensure lifelong stability of the lymphatic vasculature. In cultured lymphatic endothelial cells, FOXC2 inactivation conferred abnormal shear stress sensing, promoting junction disassembly and entry into the cell cycle. Loss of FOXC2-dependent quiescence was mediated by the Hippo pathway transcriptional coactivator TAZ and, ultimately, led to cell death. In murine models, inducible deletion of Foxc2 within the lymphatic vasculature led to cell-cell junction defects, regression of valves, and focal vascular lumen collapse, which triggered generalized lymphatic vascular dysfunction and lethality. Together, our work describes a fundamental mechanism by which FOXC2 and oscillatory shear stress maintain lymphatic endothelial cell quiescence through intercellular junction and cytoskeleton stabilization and provides an essential link between biomechanical forces and endothelial cell identity that is necessary for postnatal vessel homeostasis. As FOXC2 is mutated in lymphedema-distichiasis syndrome, our data also underscore the role of impaired mechanotransduction in the pathology of this hereditary human disease.

  3. Photoacoustic lymphatic imaging with high spatial-temporal resolution.

    PubMed

    Martel, Catherine; Yao, Junjie; Huang, Chih-Hsien; Zou, Jun; Randolph, Gwendalyn J; Wang, Lihong V

    2014-11-01

    Despite its critical function in coordinating the egress of inflammatory and immune cells out of tissues and maintaining fluid balance, the causative role of lymphatic network dysfunction in pathological settings is still understudied. Engineered-animal models and better noninvasive high spatial-temporal resolution imaging techniques in both preclinical and clinical studies will help to improve our understanding of different lymphatic-related pathologic disorders. Our aim was to take advantage of our newly optimized noninvasive wide-field fast-scanning photoacoustic (PA) microcopy system to coordinately image the lymphatic vasculature and its flow dynamics, while maintaining high resolution and detection sensitivity. Here, by combining the optical-resolution PA microscopy with a fast-scanning water-immersible microelectromechanical system scanning mirror, we have imaged the lymph dynamics over a large field-of-view, with high spatial resolution and advanced detection sensitivity. Depending on the application, lymphatic vessels (LV) were spectrally or temporally differentiated from blood vessels. Validation experiments were performed on phantoms and in vivo to identify the LV. Lymphatic flow dynamics in nonpathological and pathological conditions were also visualized. These results indicate that our newly developed PA microscopy is a promising tool for lymphatic-related biological research.

  4. FOXC2 and fluid shear stress stabilize postnatal lymphatic vasculature

    PubMed Central

    Sabine, Amélie; Bovay, Esther; Demir, Cansaran Saygili; Kimura, Wataru; Jaquet, Muriel; Agalarov, Yan; Zangger, Nadine; Scallan, Joshua P.; Graber, Werner; Gulpinar, Elgin; Kwak, Brenda R.; Mäkinen, Taija; Martinez-Corral, Inés; Ortega, Sagrario; Delorenzi, Mauro; Kiefer, Friedemann; Davis, Michael J.; Djonov, Valentin; Miura, Naoyuki; Petrova, Tatiana V.

    2015-01-01

    Biomechanical forces, such as fluid shear stress, govern multiple aspects of endothelial cell biology. In blood vessels, disturbed flow is associated with vascular diseases, such as atherosclerosis, and promotes endothelial cell proliferation and apoptosis. Here, we identified an important role for disturbed flow in lymphatic vessels, in which it cooperates with the transcription factor FOXC2 to ensure lifelong stability of the lymphatic vasculature. In cultured lymphatic endothelial cells, FOXC2 inactivation conferred abnormal shear stress sensing, promoting junction disassembly and entry into the cell cycle. Loss of FOXC2-dependent quiescence was mediated by the Hippo pathway transcriptional coactivator TAZ and, ultimately, led to cell death. In murine models, inducible deletion of Foxc2 within the lymphatic vasculature led to cell-cell junction defects, regression of valves, and focal vascular lumen collapse, which triggered generalized lymphatic vascular dysfunction and lethality. Together, our work describes a fundamental mechanism by which FOXC2 and oscillatory shear stress maintain lymphatic endothelial cell quiescence through intercellular junction and cytoskeleton stabilization and provides an essential link between biomechanical forces and endothelial cell identity that is necessary for postnatal vessel homeostasis. As FOXC2 is mutated in lymphedema-distichiasis syndrome, our data also underscore the role of impaired mechanotransduction in the pathology of this hereditary human disease. PMID:26389677

  5. Blocking development of a CD8+ T cell response by targeting lymphatic recruitment of APC.

    PubMed

    Teoh, Denise; Johnson, Louise A; Hanke, Tomas; McMichael, Andrew J; Jackson, David G

    2009-02-15

    Generating a protective immune response to viral infection is known to depend upon the priming and clonal expansion of virus-specific CD8(+) T cells by Ag-loaded dendritic cells (DC) within secondary lymphoid tissue. However, the actual initiation of the response involves critical upstream events that control the recruitment of mature Ag-charged DC from the periphery via afferent lymphatics, events that are still only partly understood. Recent evidence has revealed that transmigration of lymphatic endothelium by DC is regulated by the adhesion molecules ICAM-1 and VCAM-1 both in vitro and in vivo. These findings imply that lymphatic entry may be an important rate-limiting step in primary immunity and a possible target for immune intervention. In this study, we have explored such possibilities using an F(5) TCR-transgenic mouse model to assess the contribution of lymphatic cell adhesion molecules in the CD8(+) T cell response to influenza virus nucleoprotein (NP). We show for the first time that immunization with ICAM-1- and VCAM-1-blocking mAbs can impair the T cell response in lymph node-draining sites of dermally administered nucleoprotein vaccine (MVA.HIVA.NP) by targeting lymphatic uptake of Ag-loaded DC ahead of other cell adhesion molecule-dependent events. These results reveal lymphatic entry as an important step that may be rate limiting in the development of immunity and reconfirm its potential as a target for localized immunotherapy in inflammation and tissue rejection.

  6. Measurement of cytosolic Ca2+ in isolated contractile lymphatics.

    PubMed

    Souza-Smith, Flavia M; Kurtz, Kristine M; Breslin, Jerome W

    2011-01-01

    ) over time in isolated, perfused lymphatics in order to study Ca(2+)-dependent and Ca(2+)-sensitizing mechanisms of lymphatic smooth muscle contraction. Using isolated rat mesenteric collecting lymphatics we studied stretch-induced changes in [Ca(2+)](i) and contractile activity. The isolated lymphatic model offers the advantage that pressure, flow, and the chemical composition of the bath solution can be tightly controlled. [Ca(2+)](i) was determined by loading lymphatics with the ratiometric, Ca(2+)-binding dye Fura-2. These studies will provide a new approach to the broader problem of studying the different molecular mechanisms that regulate phasic contractions versus tonic constriction in lymphatic smooth muscle.

  7. Cutaneous lymphatic sporotrichosis.

    PubMed

    Anandi, V; Kurien, T; Jacob, M; Koshi, G

    1994-01-01

    The first case of cutaneous lymphatic sporotrichosis from Nagaland and a case of cutaneous sporotrichosis from Kerala who had acquired infection from Assam are reported. The diagnosis in both cases were established by isolating Sporothrix schenckii from multiple cutaneous lesions. The dimorphic nature of fungus was established in vitro by demonstrating the mycelial phase at 25-30 degrees C and yeast phase at 37 degrees C and pathogenicity to white mice. Both the patients were successfully treated with oral administration of potassium iodide for 3 months. PMID:8088907

  8. Chronic lower limb wounds evoke systemic response of the lymphatic (immune) system

    PubMed Central

    Olszewski, W. L.; Jain, P.; Zaleska, M.; Stelmach, E.; Swoboda, E.

    2012-01-01

    Wound healing should not be considered as a process limited only to the damaged tissues. It is always accompanied by an intensive local immune response and in advanced stages, the systemic lymphatic (immune) structure. In this review we present evidence from our own studies as well as pertinent literature on the role of skin and subcutaneous tissue lymphatics at the wound site and of transport of antigens along with collecting afferent lymphatics to the lymph nodes. We also speculate the role of lymph nodes in raising cohorts of bacterial and own tissue antigen-specific lymphocytes and their participation in healing and not infrequently evoking uncontrolled chronic immune reaction causing a delay of healing. It is also speculated as to why there is a rapid response of lymph node cells to microbial antigens and tolerance to damaged-tissue-derived antigens occurs PMID:23162224

  9. Utricular afferents: morphology of peripheral terminals

    PubMed Central

    Huwe, J. A.; Logan, G. J.; Williams, B.; Rowe, M. H.

    2015-01-01

    The utricle provides critical information about spatiotemporal properties of head movement. It comprises multiple subdivisions whose functional roles are poorly understood. We previously identified four subdivisions in turtle utricle, based on hair bundle structure and mechanics, otoconial membrane structure and hair bundle coupling, and immunoreactivity to calcium-binding proteins. Here we ask whether these macular subdivisions are innervated by distinctive populations of afferents to help us understand the role each subdivision plays in signaling head movements. We quantified the morphology of 173 afferents and identified six afferent classes, which differ in structure and macular locus. Calyceal and dimorphic afferents innervate one striolar band. Bouton afferents innervate a second striolar band; they have elongated terminals and the thickest processes and axons of all bouton units. Bouton afferents in lateral (LES) and medial (MES) extrastriolae have small-diameter axons but differ in collecting area, bouton number, and hair cell contacts (LES >> MES). A fourth, distinctive population of bouton afferents supplies the juxtastriola. These results, combined with our earlier findings on utricular hair cells and the otoconial membrane, suggest the hypotheses that MES and calyceal afferents encode head movement direction with high spatial resolution and that MES afferents are well suited to signal three-dimensional head orientation and striolar afferents to signal head movement onset. PMID:25632074

  10. Lymphatic System in Cardiovascular Medicine.

    PubMed

    Aspelund, Aleksanteri; Robciuc, Marius R; Karaman, Sinem; Makinen, Taija; Alitalo, Kari

    2016-02-01

    The mammalian circulatory system comprises both the cardiovascular system and the lymphatic system. In contrast to the blood vascular circulation, the lymphatic system forms a unidirectional transit pathway from the extracellular space to the venous system. It actively regulates tissue fluid homeostasis, absorption of gastrointestinal lipids, and trafficking of antigen-presenting cells and lymphocytes to lymphoid organs and on to the systemic circulation. The cardinal manifestation of lymphatic malfunction is lymphedema. Recent research has implicated the lymphatic system in the pathogenesis of cardiovascular diseases including obesity and metabolic disease, dyslipidemia, inflammation, atherosclerosis, hypertension, and myocardial infarction. Here, we review the most recent advances in the field of lymphatic vascular biology, with a focus on cardiovascular disease.

  11. Renal afferents signaling diuretic activity in the cat.

    PubMed

    Genovesi, S; Pieruzzi, F; Wijnmaalen, P; Centonza, L; Golin, R; Zanchetti, A; Stella, A

    1993-11-01

    Mechanoreceptors and chemoreceptors have been identified inside the kidney, but their functional role is still largely unclear. The aim of this study was to investigate whether changes in urine output could modify the discharge rate of renal afferent fibers. Experiments were performed in anesthetized cats in which afferent renal nerve activity (ARNA) was recorded by standard electrophysiological techniques from a centrally cut renal nerve. Arterial pressure, renal blood flow velocity, urine flow rate, and renal pelvic pressure were also measured. Three diuretic maneuvers were tested in the same cat: intravenous administration of physiological saline (8 to 13 mL/min for 2 minutes), furosemide (1 mg/kg), and atrial natriuretic peptide (ANP, 1 microgram/kg). The three maneuvers increased urine flow rate and pelvic pressure, respectively, 137.0 +/- 20.6% and 136.8 +/- 21.1% (saline), 148.6 +/- 31.7% and 139.6 +/- 43.5% (furosemide), and 75.9 +/- 7.9% and 62.1 +/- 21.2% (ANP) at the time of the maximum response. Arterial pressure slightly increased after saline, did not change after furosemide, and slightly decreased after ANP. Renal blood flow increased after saline and did not change after furosemide and ANP. The three maneuvers increased ARNA by 98.4 +/- 15.2% (saline), 270.7 +/- 100.8% (furosemide), and 59.6 +/- 23.4% (ANP). Changes in ARNA significantly correlate with changes in both pelvic pressure and urine flow rate. Our data demonstrate that increments in urine flow rate increase the firing rate of renal afferent fibers and suggest that (1) pelvic pressure is the major determinant of the neural response, and (2) this increased afferent discharge is due to activation of renal mechanoreceptors.

  12. Immunology of lymphatic filariasis.

    PubMed

    Babu, S; Nutman, T B

    2014-08-01

    The immune responses to filarial parasites encompass a complex network of innate and adaptive cells whose interaction with the parasite underlies a spectrum of clinical manifestations. The predominant immunological feature of lymphatic filariasis is an antigen-specific Th2 response and an expansion of IL-10 producing CD4(+) T cells that is accompanied by a muted Th1 response. This antigen-specific T-cell hyporesponsiveness appears to be crucial for the maintenance of the sustained, long-standing infection often with high parasite densities. While the correlates of protective immunity to lymphatic filariasis are still incompletely understood, primarily due to the lack of suitable animal models to study susceptibility, it is clear that T cells and to a certain extent B cells are required for protective immunity. Host immune responses, especially CD4(+) T-cell responses clearly play a role in mediating pathological manifestations of LF, including lymphedema, hydrocele and elephantiasis. The main underlying defect in the development of clinical pathology appears to be a failure to induce T-cell hyporesponsiveness in the face of antigenic stimulation. Finally, another intriguing feature of filarial infections is their propensity to induce bystander effects on a variety of immune responses, including responses to vaccinations, allergens and to other infectious agents. The complexity of the immune response to filarial infection therefore provides an important gateway to understanding the regulation of immune responses to chronic infections, in general.

  13. Immunology of lymphatic filariasis

    PubMed Central

    Babu, Subash; Nutman, Thomas B.

    2013-01-01

    The immune responses to filarial parasites encompass a complex network of innate and adaptive cells whose interaction with the parasite underlies a spectrum of clinical manifestations. The predominant immunological feature of lymphatic filariasis is an antigen - specific Th2 response and an expansion of IL-10 producing CD4+ T cells that is accompanied by a muted Th1 response. This antigen specific T cell hypo-responsiveness appears to be crucial for the maintenance of the sustained, long-standing infection often with high parasite densities. While the correlates of protective immunity to lymphatic filariasis are still incompletely understood, primarily due to the lack of suitable animal models to study susceptibility, it is clear that T cells and to a certain extent B cells are required for protective immunity. Host immune responses, especially CD4+ T cell responses clearly play a role in mediating pathological manifestations of LF, including lymphedema, hydrocele and elephantiasis. The main underlying defect in the development of clinical pathology appears to be a failure to induce T cell hypo-responsiveness in the face of antigenic stimulation. Finally, another intriguing feature of filarial infections is their propensity to induce bystander effects on a variety of immune responses, including responses to vaccinations, allergens and to other infectious agents. The complexity of the immune response to filarial infection therefore provides an important gateway to understanding the regulation of immune responses to chronic infections, in general. PMID:24134686

  14. Lymphatic transport of exosomes as a rapid route of information dissemination to the lymph node

    PubMed Central

    Srinivasan, Swetha; Vannberg, Fredrik O.; Dixon, J. Brandon

    2016-01-01

    It is well documented that cells secrete exosomes, which can transfer biomolecules that impact recipient cells’ functionality in a variety of physiologic and disease processes. The role of lymphatic drainage and transport of exosomes is as yet unknown, although the lymphatics play critical roles in immunity and exosomes are in the ideal size-range for lymphatic transport. Through in vivo near-infrared (NIR) imaging we have shown that exosomes are rapidly transported within minutes from the periphery to the lymph node by lymphatics. Using an in vitro model of lymphatic uptake, we have shown that lymphatic endothelial cells actively enhanced lymphatic uptake and transport of exosomes to the luminal side of the vessel. Furthermore, we have demonstrated a differential distribution of exosomes in the draining lymph nodes that is dependent on the lymphatic flow. Lastly, through endpoint analysis of cellular distribution of exosomes in the node, we identified macrophages and B-cells as key players in exosome uptake. Together these results suggest that exosome transfer by lymphatic flow from the periphery to the lymph node could provide a mechanism for rapid exchange of infection-specific information that precedes the arrival of migrating cells, thus priming the node for a more effective immune response. PMID:27087234

  15. Newborn intraabdominal cystic lymphatic malformations.

    PubMed

    Lin, J I; Fisher, J; Caty, M G

    2000-08-01

    Cystic lymphatic malformations are rare causes of abdominal masses in the newborn. Also known as mesenteric, omental, or retroperitoneal cysts, they can present in a variety of ways including, intestinal obstruction, volvulus, nonspecific abdominal pain, intracystic hemorrhage, or as an asymptomatic abdominal mass. Abdominal ultrasound scan provides a definitive diagnosis in most suspected cases. Complete resection is possible in most patients except those with extensive retroperitoneal involvement. Recurrence is unusual when complete resection is accomplished. Because most case series with complete data suggest that these entities are lymphatic malformations, the authors suggest the more specific term, cystic lymphatic malformations, be used to describe these lesions.

  16. Frequency response properties of primary afferent neurons in the posterior lateral line system of larval zebrafish

    PubMed Central

    Levi, Rafael; Akanyeti, Otar; Ballo, Aleksander

    2014-01-01

    The ability of fishes to detect water flow with the neuromasts of their lateral line system depends on the physiology of afferent neurons as well as the hydrodynamic environment. Using larval zebrafish (Danio rerio), we measured the basic response properties of primary afferent neurons to mechanical deflections of individual superficial neuromasts. We used two types of stimulation protocols. First, we used sine wave stimulation to characterize the response properties of the afferent neurons. The average frequency-response curve was flat across stimulation frequencies between 0 and 100 Hz, matching the filtering properties of a displacement detector. Spike rate increased asymptotically with frequency, and phase locking was maximal between 10 and 60 Hz. Second, we used pulse train stimulation to analyze the maximum spike rate capabilities. We found that afferent neurons could generate up to 80 spikes/s and could follow a pulse train stimulation rate of up to 40 pulses/s in a reliable and precise manner. Both sine wave and pulse stimulation protocols indicate that an afferent neuron can maintain their evoked activity for longer durations at low stimulation frequencies than at high frequencies. We found one type of afferent neuron based on spontaneous activity patterns and discovered a correlation between the level of spontaneous and evoked activity. Overall, our results establish the baseline response properties of lateral line primary afferent neurons in larval zebrafish, which is a crucial step in understanding how vertebrate mechanoreceptive systems sense and subsequently process information from the environment. PMID:25355959

  17. [Lymphatic vascular system, development and lymph formation. Review].

    PubMed

    Bernaudin, J-F; Kambouchner, M; Lacave, R

    2013-04-01

    The lymphatic vascular system is widely developed among vertebrates. Lymphatic vessels provide the interstitial fluid (20% of the body weight) drainage through interstitial prelymphatic channels, capillaries, precollectors and collectors flowing into the venous blood. Endothelial cells of capillaries are overlapped and fixed to interstitial collagen and elastic fibres by anchoring filaments facilitating the fluid transfer. Precollectors and collectors have valves controlling the lymph flux direction. In addition to external mechanisms, the lymphangions of collectors have contracting muscle cells driving the flow. Lymphatic endothelial cells are routinely identified by the expression of podoplanin, LYVE-1 and VEGFR3. In the embryo, prelymphatic endothelial cells emerge from the cardinal veins and migrate into the mesenchyma forming embryonic lymphatic sacs. Prox1, Sox18 and COUP-TFII play a major role in the endothelial speciation, VEGFC as VEGFD combined to VEGFR3 in cell migration and proliferation and FoxC2 in valves development. In cancer or inflammation, various factors secreted by cancer cells and/or inflammatory cells induce a neolymphangiogenesis. Recently it has been shown that cells from the bone marrow could be potential precursors for lymphatic endothelial cells.

  18. Contractile activity of lymphatic vessels is altered in the TNBS model of guinea pig ileitis.

    PubMed

    Wu, Theresa F; Carati, Colin J; Macnaughton, Wallace K; von der Weid, Pierre-Yves

    2006-10-01

    The ability of the lymphatic system to actively remove fluid from the interstitium is critical to the resolution of edema. The response of the lymphatics to inflammatory situations is poorly studied, so we examined mesenteric lymphatic contractile activity in the 2,4,6-trinitrobenzenesulfonic acid (TNBS) model of guinea pig ileitis, a well-accepted animal model of intestinal inflammation, by videomicroscopy in vivo and in vitro 1, 3, and 6 days after induction of ileitis. Lymphatic function (diameter, constriction frequency, amplitude of constrictions, and calculated stroke volume and lymph flow rate) of isolated vessels from TNBS-treated guinea pigs were impaired compared with sham-treated controls. The dysfunction was well correlated with the degree of inflammation, with differences reaching significance (P < 0.05) at the highest inflammation-induced damage observed at day 3. In vivo, significantly fewer lymphatics exhibited spontaneous constrictions in TNBS-treated than sham-treated animals. Cyclooxygenase (COX) metabolites were suggested to be involved in this lymphatic dysfunction, since application of nonselective COX inhibitor (10 microM indomethacin) or a combination of COX-1 and COX-2 inhibitors (1 microM SC-560 and 10 microM celecoxib) markedly increased constriction frequency or induced them in lymphatics from TNBS-treated animals in vivo and in vitro. The present results demonstrate that lymphatic contractile function is altered in TNBS-induced ileitis and suggest a role for prostanoids in the lymphatic dysfunction.

  19. Lymphatic Regulation of Cellular Trafficking

    PubMed Central

    Jackson, David G.

    2016-01-01

    Lymphatic vessels play vital roles in immune surveillance and immune regulation by conveying antigen loaded dendritic cells, memory T cells, macrophages and neutrophils from the peripheral tissues to draining lymph nodes where they initiate as well as modify immune responses. Until relatively recently however, there was little understanding of how entry and migration through lymphatic vessels is organized or the specific molecular mechanisms that might be involved. Within the last decade, the situation has been transformed by an explosion of knowledge generated largely through the application of microscopic imaging, transgenic animals, specific markers and function blocking mAbs that is beginning to provide a rational conceptual framework. This article provides a critical review of the recent literature, highlighting seminal discoveries that have revealed the fascinating ultrastructure of leucocyte entry sites in lymphatic vessels, as well as generating controversies over the involvement of integrin adhesion, chemotactic and haptotactic mechanisms in DC entry under normal and inflamed conditions. It also discusses the major changes in lymphatic architecture that occur during inflammation and the different modes of leucocyte entry and trafficking within inflamed lymphatic vessels, as well as presenting a timely update on the likely role of hyaluronan and the major lymphatic endothelial hyaluronan receptor LYVE-1 in leucocyte transit.

  20. Cardiovascular effects of afferent renal nerve stimulation.

    PubMed

    Stella, A; Weaver, L; Golin, R; Genovesi, S; Zanchetti, A

    1987-01-01

    Electrical stimulation of afferent renal nerves elicits an increase in arterial pressure and heart rate. The hypertensive response is presumably due to the widespread activation of the sympathetic nervous system leading to peripheral vasoconstriction. Interestingly, the kidney does not appear involved in this reflex excitatory response to afferent renal nerve stimulation since changes in vascular conductances and excretory functions are equal in both the innervated and denervated kidney, and secondary to changes in renal perfusion pressure. In addition, no changes in renin release from either kidneys are observed during afferent renal nerve stimulation. It is likely that the electrical stimulation of afferent renal nerves activates other reflexes exerting an inhibitory influence on efferent renal nerve activity. Indeed, neural renorenal reflexes which tonically inhibit renal functions have clearly been demonstrated. Furthermore, preferential inhibition of efferent renal nerve activity by cardiopulmonary and sinoaortic receptors has recently been shown during activation of other visceral afferents.

  1. Lymphatic regulation in nonmammalian vertebrates.

    PubMed

    Hedrick, Michael S; Hillman, Stanley S; Drewes, Robert C; Withers, Philip C

    2013-08-01

    All vertebrate animals share in common the production of lymph through net capillary filtration from their closed circulatory system into their tissues. The balance of forces responsible for net capillary filtration and lymph formation is described by the Starling equation, but additional factors such as vascular and interstitial compliance, which vary markedly among vertebrates, also have a significant impact on rates of lymph formation. Why vertebrates show extreme variability in rates of lymph formation and how nonmammalian vertebrates maintain plasma volume homeostasis is unclear. This gap hampers our understanding of the evolution of the lymphatic system and its interaction with the cardiovascular system. The evolutionary origin of the vertebrate lymphatic system is not clear, but recent advances suggest common developmental factors for lymphangiogenesis in teleost fishes, amphibians, and mammals with some significant changes in the water-land transition. The lymphatic system of anuran amphibians is characterized by large lymphatic sacs and two pairs of lymph hearts that return lymph into the venous circulation but no lymph vessels per se. The lymphatic systems of reptiles and some birds have lymph hearts, and both groups have extensive lymph vessels, but their functional role in both lymph movement and plasma volume homeostasis is almost completely unknown. The purpose of this review is to present an evolutionary perspective in how different vertebrates have solved the common problem of the inevitable formation of lymph from their closed circulatory systems and to point out the many gaps in our knowledge of this evolutionary progression.

  2. Lymphatic regulation in nonmammalian vertebrates.

    PubMed

    Hedrick, Michael S; Hillman, Stanley S; Drewes, Robert C; Withers, Philip C

    2013-08-01

    All vertebrate animals share in common the production of lymph through net capillary filtration from their closed circulatory system into their tissues. The balance of forces responsible for net capillary filtration and lymph formation is described by the Starling equation, but additional factors such as vascular and interstitial compliance, which vary markedly among vertebrates, also have a significant impact on rates of lymph formation. Why vertebrates show extreme variability in rates of lymph formation and how nonmammalian vertebrates maintain plasma volume homeostasis is unclear. This gap hampers our understanding of the evolution of the lymphatic system and its interaction with the cardiovascular system. The evolutionary origin of the vertebrate lymphatic system is not clear, but recent advances suggest common developmental factors for lymphangiogenesis in teleost fishes, amphibians, and mammals with some significant changes in the water-land transition. The lymphatic system of anuran amphibians is characterized by large lymphatic sacs and two pairs of lymph hearts that return lymph into the venous circulation but no lymph vessels per se. The lymphatic systems of reptiles and some birds have lymph hearts, and both groups have extensive lymph vessels, but their functional role in both lymph movement and plasma volume homeostasis is almost completely unknown. The purpose of this review is to present an evolutionary perspective in how different vertebrates have solved the common problem of the inevitable formation of lymph from their closed circulatory systems and to point out the many gaps in our knowledge of this evolutionary progression. PMID:23640588

  3. lyve1 expression reveals novel lymphatic vessels and new mechanisms for lymphatic vessel development in zebrafish.

    PubMed

    Okuda, Kazuhide S; Astin, Jonathan W; Misa, June P; Flores, Maria V; Crosier, Kathryn E; Crosier, Philip S

    2012-07-01

    We have generated novel transgenic lines that brightly mark the lymphatic system of zebrafish using the lyve1 promoter. Facilitated by these new transgenic lines, we generated a map of zebrafish lymphatic development up to 15 days post-fertilisation and discovered three previously uncharacterised lymphatic vessel networks: the facial lymphatics, the lateral lymphatics and the intestinal lymphatics. We show that a facial lymphatic vessel, termed the lateral facial lymphatic, develops through a novel developmental mechanism, which initially involves vessel growth through a single vascular sprout followed by the recruitment of lymphangioblasts to the vascular tip. Unlike the lymphangioblasts that form the thoracic duct, the lymphangioblasts that contribute to the lateral facial lymphatic vessel originate from a number of different blood vessels. Our work highlights the additional complexity of lymphatic vessel development in the zebrafish that may increase its versatility as a model of lymphangiogenesis.

  4. Adaptation of Mesenteric Collecting Lymphatic Pump Function Following Acute Alcohol Intoxication

    PubMed Central

    Souza-Smith, Flavia M.; Kurtz, Kristine M.; Molina, Patricia E.; Breslin, Jerome W.

    2010-01-01

    Objective Acute alcohol intoxication increases intestinal lymph flow by unknown mechanisms, potentially impacting mucosal immunity. We tested the hypothesis that enhanced intrinsic pump function of mesenteric lymphatics contributes to increased intestinal lymph flow during alcohol intoxication. Methods Acute alcohol intoxication was produced by intragastric administration of 30% alcohol to concious, unrestrained rats through surgically-implanted catheters. Time-matched controls received either no bolus, vehicle, or isocaloric dextrose. Thirty minutes after alcohol administration, rats were anesthetized and mesenteric collecting lymphatics were isolated and cannulated to study intrinsic pumping parameters. In separate experiments, mesenteric lymphatics were isolated to examine direct effects of alcohol on intrinsic pump activity. Results Lymphatics isolated from alcohol-intoxicated animals displayed slgnificantly decreased contraction frequency (CF) than the dextrose group, elevated stroke volume index (SVI) versus all other groups, and decreased myogenic responsiveness compared to sham. Elevating pressure from 2 to 4 cm H2O increased the volume flow index 2.4-fold in the alcohol group versus 1.4-fold for shams. Isolated lymphatics exposed to 20 mM alcohol had reduced myogenic tone, without changes in CF or SVI. Conclusions Alcohol intoxication enhances intrinsic pumping by mesenteric collecting lymphatics. Alcohol directly decreases lymphatic myogenic tone, but effects on phasic contractions occur by an unidentified mechanism. PMID:21040117

  5. Impaired lymphatic contraction associated with immunosuppression.

    PubMed

    Liao, Shan; Cheng, Gang; Conner, David A; Huang, Yuhui; Kucherlapati, Raju S; Munn, Lance L; Ruddle, Nancy H; Jain, Rakesh K; Fukumura, Dai; Padera, Timothy P

    2011-11-15

    To trigger an effective immune response, antigen and antigen-presenting cells travel to the lymph nodes via collecting lymphatic vessels. However, our understanding of the regulation of collecting lymphatic vessel function and lymph transport is limited. To dissect the molecular control of lymphatic function, we developed a unique mouse model that allows intravital imaging of autonomous lymphatic vessel contraction. Using this method, we demonstrated that endothelial nitric oxide synthase (eNOS) in lymphatic endothelial cells is required for robust lymphatic contractions under physiological conditions. By contrast, under inflammatory conditions, inducible NOS (iNOS)-expressing CD11b(+)Gr-1(+) cells attenuate lymphatic contraction. This inhibition of lymphatic contraction was associated with a reduction in the response to antigen in a model of immune-induced multiple sclerosis. These results suggest the suppression of lymphatic function by the CD11b(+)Gr-1(+) cells as a potential mechanism of self-protection from autoreactive responses during on-going inflammation. The central role for nitric oxide also suggests that other diseases such as cancer and infection may also mediate lymphatic contraction and thus immune response. Our unique method allows the study of lymphatic function and its molecular regulation during inflammation, lymphedema, and lymphatic metastasis.

  6. Functional adaptation of bovine mesenteric lymphatic vessels to mesenteric venous hypertension

    PubMed Central

    Criscione, John C.; Kotiya, Akhilesh; Dongaonkar, Ranjeet M.; Hardy, Joanne; Wilson, Emily; Gashev, Anatoliy A.; Laine, Glen A.; Stewart, Randolph H.

    2014-01-01

    Lymph flow is the primary mechanism for returning interstitial fluid to the blood circulation. Currently, the adaptive response of lymphatic vessels to mesenteric venous hypertension is not known. This study sought to determine the functional responses of postnodal mesenteric lymphatic vessels. We surgically occluded bovine mesenteric veins to create mesenteric venous hypertension to elevate mesenteric lymph flow. Three days after surgery, postnodal mesenteric lymphatic vessels from mesenteric venous hypertension (MVH; n = 7) and sham surgery (Sham; n = 6) group animals were evaluated and compared. Contraction frequency (MVH: 2.98 ± 0.75 min−1; Sham: 5.42 ± 0.81 min−1) and fractional pump flow (MVH: 1.14 ± 0.30 min−1; Sham: 2.39 ± 0.32 min−1) were significantly lower in the venous occlusion group. These results indicate that postnodal mesenteric lymphatic vessels adapt to mesenteric venous hypertension by reducing intrinsic contractile activity. PMID:24671245

  7. Functional adaptation of bovine mesenteric lymphatic vessels to mesenteric venous hypertension.

    PubMed

    Quick, Christopher M; Criscione, John C; Kotiya, Akhilesh; Dongaonkar, Ranjeet M; Hardy, Joanne; Wilson, Emily; Gashev, Anatoliy A; Laine, Glen A; Stewart, Randolph H

    2014-06-15

    Lymph flow is the primary mechanism for returning interstitial fluid to the blood circulation. Currently, the adaptive response of lymphatic vessels to mesenteric venous hypertension is not known. This study sought to determine the functional responses of postnodal mesenteric lymphatic vessels. We surgically occluded bovine mesenteric veins to create mesenteric venous hypertension to elevate mesenteric lymph flow. Three days after surgery, postnodal mesenteric lymphatic vessels from mesenteric venous hypertension (MVH; n = 7) and sham surgery (Sham; n = 6) group animals were evaluated and compared. Contraction frequency (MVH: 2.98 ± 0.75 min(-1); Sham: 5.42 ± 0.81 min(-1)) and fractional pump flow (MVH: 1.14 ± 0.30 min(-1); Sham: 2.39 ± 0.32 min(-1)) were significantly lower in the venous occlusion group. These results indicate that postnodal mesenteric lymphatic vessels adapt to mesenteric venous hypertension by reducing intrinsic contractile activity.

  8. Mechanotransduction, PROX1, and FOXC2 cooperate to control connexin37 and calcineurin during lymphatic-valve formation.

    PubMed

    Sabine, Amélie; Agalarov, Yan; Maby-El Hajjami, Hélène; Jaquet, Muriel; Hägerling, René; Pollmann, Cathrin; Bebber, Damien; Pfenniger, Anna; Miura, Naoyuki; Dormond, Olivier; Calmes, Jean-Marie; Adams, Ralf H; Mäkinen, Taija; Kiefer, Friedemann; Kwak, Brenda R; Petrova, Tatiana V

    2012-02-14

    Lymphatic valves are essential for efficient lymphatic transport, but the mechanisms of early lymphatic-valve morphogenesis and the role of biomechanical forces are not well understood. We found that the transcription factors PROX1 and FOXC2, highly expressed from the onset of valve formation, mediate segregation of lymphatic-valve-forming cells and cell mechanosensory responses to shear stress in vitro. Mechanistically, PROX1, FOXC2, and flow coordinately control expression of the gap junction protein connexin37 and activation of calcineurin/NFAT signaling. Connexin37 and calcineurin are required for the assembly and delimitation of lymphatic valve territory during development and for its postnatal maintenance. We propose a model in which regionally increased levels/activation states of transcription factors cooperate with mechanotransduction to induce a discrete cell-signaling pattern and morphogenetic event, such as formation of lymphatic valves. Our results also provide molecular insights into the role of endothelial cell identity in the regulation of vascular mechanotransduction.

  9. Blood and lymphatic vessel formation.

    PubMed

    Bautch, Victoria L; Caron, Kathleen M

    2015-03-02

    Blood and lymphatic vessels deliver oxygen and nutrients, remove waste and CO2, and regulate interstitial pressure in tissues and organs. These vessels begin life early in embryogenesis using transcription factors and signaling pathways that regulate differentiation, morphogenesis, and proliferation. Here we describe how these vessels develop in the mouse embryo, and the signals that are important to their development.

  10. Immunopathogenesis of lymphatic filarial disease.

    PubMed

    Babu, Subash; Nutman, Thomas B

    2012-11-01

    Although two thirds of the 120 million people infected with lymph-dwelling filarial parasites have subclinical infections, ~40 million have lymphedema and/or other pathologic manifestations including hydroceles (and other forms of urogenital disease), episodic adenolymphangitis, tropical pulmonary eosinophilia, lymphedema, and (in its most severe form) elephantiasis. Adult filarial worms reside in the lymphatics and lymph nodes and induce changes that result in dilatation of lymphatics and thickening of the lymphatic vessel walls. Progressive lymphatic damage and pathology results from the summation of the effect of tissue alterations induced by both living and nonliving adult parasites, the host inflammatory response to the parasites and their secreted antigens, the host inflammatory response to the endosymbiont Wolbachia, and those seen as a consequence of secondary bacterial or fungal infections. Inflammatory damage induced by filarial parasites appears to be multifactorial, with endogenous parasite products, Wolbachia, and host immunity all playing important roles. This review will initially examine the prototypical immune responses engendered by the parasite and delineate the regulatory mechanisms elicited to prevent immune-mediated pathology. This will be followed by a discussion of the proposed mechanisms underlying pathogenesis, with the central theme being that pathogenesis is a two-step process-the first initiated by the parasite and host innate immune system and the second propagated mainly by the host's adaptive immune system and by other factors (including secondary infections). PMID:23053393

  11. Cerebral, subcortical, and cerebellar activation evoked by selective stimulation of muscle and cutaneous afferents: an fMRI study

    PubMed Central

    Wardman, Daniel L.; Gandevia, Simon C.; Colebatch, James G.

    2014-01-01

    Abstract We compared the brain areas that showed significant flow changes induced by selective stimulation of muscle and cutaneous afferents using fMRI BOLD imaging. Afferents arising from the right hand were studied in eight volunteers with electrical stimulation of the digital nerve of the index finger and over the motor point of the FDI muscle. Both methods evoked areas of significant activation cortically, subcortically, and in the cerebellum. Selective muscle afferent stimulation caused significant activation in motor‐related areas. It also caused significantly greater activation within the contralateral precentral gyrus, insula, and within the ipsilateral cerebellum as well as greater areas of reduced blood flow when compared to the cutaneous stimuli. We demonstrated separate precentral and postcentral foci of excitation with muscle afferent stimulation. We conclude, contrary to the findings with evoked potentials, that muscle afferents evoke more widespread cortical, subcortical, and cerebellar activation than do cutaneous afferents. This emphasizes the importance, for studies of movement, of matching the kinematic aspects in order to avoid the results being confounded by alterations in muscle afferent activation. The findings are consistent with clinical observations of the movement consequences of sensory loss and may also be the basis for the contribution of disturbed sensorimotor processing to disorders of movement. PMID:24771687

  12. Low-invasive lymphatic surgery and lymphatic imaging for completely healed intractable pudendal lymphorrhea after gynecologic cancer treatment.

    PubMed

    Mihara, Makoto; Hara, Hisako; Narushima, Mitsunaga; Mitsui, Kito; Murai, Noriyuki; Koshima, Isao

    2012-01-01

    Lower limb lymphedema and an accompanying lymphatic fistula (lymphorrhea) occur as complications after gynecologic surgery to treat cancer. Herein, we report the case of a 68-year-old woman who underwent resection and radiotherapy because of uterine cervical cancer (stage 2a) 20 years previously. Left lower limb and pudendal lymphedema and continuous lymphorrhea developed soon after surgery. Conservative treatment was administered; however, the edema increased, and a pudendal lymphatic fistula and cellulitis developed repeatedly. Lymphovascular anastomosis (LVA) and lymph vessel ligation were performed after preoperative evaluation via lymphoscintigraphy and indocyanine green (ICG) lymphography. A radioisotope injected into the first interdigit pedal region flowed into the pudendal region via the inguinal lymph nodes at preoperative lymphoscintigraphy. Linear patterns were observed up to the half level of the crus, and stardust patterns occurred over the lower abdominal and pudendal regions at ICG lymphography. During surgery, ICG lymphography was also used to identify the site of the fistula. With the patient under local anesthesia, LVA was applied in the half crus and left inguinal regions, followed by ligation and division of lymph vessels flowing into the fistula. The region around the fistula was excised as a 1 × 3-cm tissue block. As of 5 months after surgery, no recurrence of lymphatic fistula or exacerbation of lymphedema has occurred. This case shows the effectiveness of preoperative ICG lymphography and lymphoscintigraphy followed by treatment via lymph vessel ligation and LVA for curative resolution of a lymphatic fistula.

  13. Functional imaging in tumor-associated lymphatics

    NASA Astrophysics Data System (ADS)

    Kwon, Sunkuk; Sevick-Muraca, Eva M.

    2011-03-01

    The lymphatic system plays an important role in cancer cell dissemination; however whether lymphatic drainage pathways and function change during tumor progression and metastasis remains to be elucidated. In this report, we employed a non-invasive, dynamic near-infrared (NIR) fluorescence imaging technique for functional lymphatic imaging. Indocyanine green (ICG) was intradermally injected into tumor-free mice and mice bearing C6/LacZ rat glioma tumors in the tail or hindlimb. Our imaging data showed abnormal lymphatic drainage pathways and reduction/loss of lymphatic contractile function in mice with lymph node (LN) metastasis, indicating that cancer metastasis to the draining LNs is accompanied by transient changes of the lymphatic architectural network and its function. Therefore, functional lymphatic imaging may provide a role in the clinical staging of cancer.

  14. Piezo2 expression in corneal afferent neurons.

    PubMed

    Bron, Romke; Wood, Rhiannon J; Brock, James A; Ivanusic, Jason J

    2014-09-01

    Recently, a novel class of mechanically sensitive channels has been identified and have been called Piezo channels. In this study, we explored Piezo channel expression in sensory neurons supplying the guinea pig corneal epithelium, which have well-defined modalities in this species. We hypothesized that a proportion of corneal afferent neurons express Piezo2, and that these neurons are neurochemically distinct from corneal polymodal nociceptors or cold-sensing neurons. We used a combination of retrograde tracing to identify corneal afferent neurons and double label in situ hybridization and/or immunohistochemistry to determine their molecular and/or neurochemical profile. We found that Piezo2 expression occurs in ∼26% of trigeminal ganglion neurons and 30% of corneal afferent neurons. Piezo2 corneal afferent neurons are almost exclusively non-calcitonin gene-related peptide (CGRP)-immunoreactive (-IR), medium- to large-sized neurons that are NF200-IR, suggesting they are not corneal polymodal nociceptors. There was no coexpression of Piezo2 and transient receptor potential cation channel subfamily M member 8 (TRPM8) transcripts in any corneal afferent neurons, further suggesting that Piezo2 is not expressed in corneal cold-sensing neurons. We also noted that TRPM8-IR or CGRP-IR corneal afferent neurons are almost entirely small and lack NF200-IR. Piezo2 expression occurs in a neurochemically distinct subpopulation of corneal afferent neurons that are not polymodal nociceptors or cold-sensing neurons, and is likely confined to a subpopulation of pure mechano-nociceptors in the cornea. This provides the first evidence in an in vivo system that Piezo2 is a strong candidate for a channel that transduces noxious mechanical stimuli.

  15. Afferent Connectivity of the Zebrafish Habenulae

    PubMed Central

    Turner, Katherine J.; Hawkins, Thomas A.; Yáñez, Julián; Anadón, Ramón; Wilson, Stephen W.; Folgueira, Mónica

    2016-01-01

    The habenulae are bilateral nuclei located in the dorsal diencephalon that are conserved across vertebrates. Here we describe the main afferents to the habenulae in larval and adult zebrafish. We observe afferents from the subpallium, nucleus rostrolateralis, posterior tuberculum, posterior hypothalamic lobe, median raphe; we also see asymmetric afferents from olfactory bulb to the right habenula, and from the parapineal to the left habenula. In addition, we find afferents from a ventrolateral telencephalic nucleus that neurochemical and hodological data identify as the ventral entopeduncular nucleus (vENT), confirming and extending observations of Amo et al. (2014). Fate map and marker studies suggest that vENT originates from the diencephalic prethalamic eminence and extends into the lateral telencephalon from 48 to 120 hour post-fertilization (hpf). No afferents to the habenula were observed from the dorsal entopeduncular nucleus (dENT). Consequently, we confirm that the vENT (and not the dENT) should be considered as the entopeduncular nucleus “proper” in zebrafish. Furthermore, comparison with data in other vertebrates suggests that the vENT is a conserved basal ganglia nucleus, being homologous to the entopeduncular nucleus of mammals (internal segment of the globus pallidus of primates) by both embryonic origin and projections, as previously suggested by Amo et al. (2014). PMID:27199671

  16. Vestibular afferent responses to microrotational stimuli

    NASA Technical Reports Server (NTRS)

    Myers, Steven F.; Lewis, Edwin R.

    1991-01-01

    Intracellular microelectrode recording/labeling techniques were used to investigate vestibular afferent responses in the bullfrog, to very small amplitude (less than 5 deg p-p) sinusoidal rotations in the vertical plane over the frequency range of 0.063-4 Hz. Robust responses to peak accelerations as low as 0.031 deg/sec per sec were obtained from units subsequently traced to either the central portion of the anterior canal crista or the striolar region of the utricle. All of these microrotationally sensitive afferent neurons had irregular resting discharge rates, and the majority had transfer ratios (relative to rotational velocity) of 1-40 spikes/sec per deg/sec. Individual utricular afferent velocity transfer ratios were nearly constant over the frequency range of 0.125-4 Hz. Canal units displayed decreasing response transfer ratios as stimulus frequencies increased. These findings indicate that, although utricular striolar and central crista afferent velocity transfer ratios to microrotations were very similar, utricular striolar afferent neurons were more faithful sensors of very small amplitude rotational velocity in the vertical plane.

  17. Lymphatic function in the liver after hepatic venous pressure elevation.

    PubMed

    Elk, J R; Drake, R E; Williams, J P; Gabel, J C; Laine, G A

    1988-05-01

    The liver lymphatic system plays an important role in removing excess fluid from the hepatic tissue. A complete analysis of the liver lymphatic system would be difficult. However, we used a simple circuit-analysis technique to represent the intrahepatic portion of the lymph system as a single pressure source (PL) pushing lymph through a single resistance (RL). Liver lymphatic vessels were cannulated in nine halothane-anesthetized dogs. The lymphatic vessel outflow pressure (PO) was varied by raising the outflow end of the cannula. Lymph flow from the cannula (QL) decreased linearly with PO, and we calculated RL as -delta PO/delta QL and PL as the extrapolated PO at which QL = 0. At base line, PL = 8.5 +/- 2.9 cmH2O, and RL = 0.05 +/- 0.03 cmH2O.min/microliter. After we increased inferior vena caval pressure from 5.8 +/- 2.7 to 15.2 +/- 2.5 cmH2O, PL increased significantly to 13.7 +/- 3.4 cmH2O, and RL decreased to 0.02 +/- 0.02 cmH2O.min/microliter (P less than 0.05). The results indicate that increases in QL occur because the effective pressure pushing lymph from the liver (PL) increases, and the effective resistance of the intrahepatic lymph vessels (RL) decreases.

  18. Lymphatic Vascular Response to Acute Inflammation

    PubMed Central

    Lachance, Pier-Anne; Hazen, Amy; Sevick-Muraca, Eva M.

    2013-01-01

    During acute inflammation, functioning lymphatics are believed to reduce edema and to provide a transiting route for immune cells, but the extent at which the dermal lymphatic remodeling impacts lymphatic transport or the factors regulating these changes remains unclear. Herein we quantify the increase in lymphatic endothelial cells (LECs) and examine the expression of pro-angiogenenic and lymphangiogenic factors during acute cutaneous hypersensitivity (CHS). We found that LECs actively proliferate during CHS but that this proliferation does not affect the lymphatic vessel density. Instead, lymphatic remodeling is accompanied by lymphatic vessel leakiness and lower ejection of lymph fluid, which is observed only in the proximal lymphatic vessel draining the inflamed area. LECs and the immune cells release growth factors and cytokines during inflammation, which impact the lymphatic microenvironment and function. We identified that FGF-2, PLGF-2, HGF, EGF, and KC/CXCL17 are differentially expressed within tissues during acute CHS, but both VEGF-C and VEGF-D levels do not significantly change. Our results indicate that VEGF-C and VEGF-D are not the only players and other factors may be responsible for the LECs proliferation and altered lymphatic function in acute CHS. PMID:24086691

  19. Lymphatics and blood vessels.

    PubMed

    Millikan, Larry E

    2011-01-01

    The traditional nomenclature of vascular lesions has been enlarged and modified with the usage of newer diagnostic techniques. Digital technology has enhanced the precision of older analog tools such as Doppler flow studies. Angiograms have also more precisely delineated flow patterns to allow planned surgical intervention as an important therapeutic option. With the newer classification, it now is possible to plan and anticipate the course of lesions and medically intervene in tumors that potentially will enlarge and impinge on essential structures. Now, the routine workup will clarify if there is internal involvement (eg, liver, etc) and detect proliferative potential mandating medical or surgical intervention. Watchful waiting, the traditional approach is now changing with the newer delineation of syndromes such as PHACE (posterior fossa, hemangioma, arterial lesions, cardiac abnormalities/aortic coarctation, eye abnormalities), which mandate the fullest evaluation and, in many instances, the collaboration of multispecialty groups to treat those lesions as the data and group consensus determines.

  20. Lymphatic Territories (Lymphosomes) in a Canine: An Animal Model for Investigation of Postoperative Lymphatic Alterations

    PubMed Central

    Suami, Hiroo; Yamashita, Shuji; Soto-Miranda, Miguel A.; Chang, David W.

    2013-01-01

    Background Lymph node dissection is often performed as a part of surgical treatment for breast cancer and malignant melanoma to prevent malignant cells from traveling via the lymphatic system. Currently little is known about postoperative lymphatic drainage pattern alterations. This knowledge may be useful for management of recurrent cancer and prevention of breast cancer related lymphedema. We mapped the complete superficial lymphatic system of a dog and used this canine model to perform preliminary studies of lymphatic architectural changes in postoperative condition. Methods Lymphatic territories (lymphosomes) were mapped with 4 female mongrel carcasses using an indocyanine green (ICG) fluorescent lymphography and a radiographic microinjection technique. Two live dogs were then subjected to unilateral lymph node dissection of lymph basins of the forelimb, and ICG lymphography and lymphangiogram were performed 6 months after the surgery to investigate lymphatic changes. Lymphatic patterns in the carcass were then compared with postoperative lymphatic patterns in the live dogs. Results Ten lymphosomes were identified, corresponding with ten lymphatic basins. Postoperative fluorescent lymphographic images and lymphangiograms in the live dogs revealed small caliber lymphatic network fulfilling gaps in the surgical area and collateral lymphatic vessels arising from the network connecting to lymph nodes in the contralateral and ipsilateral neck in one dog and the ipsilateral subclavicular vein in another dog. Conclusion Our canine lymphosome map allowed us to observe lymphatic collateral formations after lymph node dissection in live dogs. This canine model may help clarify our understanding of postoperative lymphatic changes in humans in future studies. PMID:23894435

  1. Detection thresholds of macaque otolith afferents.

    PubMed

    Yu, Xiong-Jie; Dickman, J David; Angelaki, Dora E

    2012-06-13

    The vestibular system is our sixth sense and is important for spatial perception functions, yet the sensory detection and discrimination properties of vestibular neurons remain relatively unexplored. Here we have used signal detection theory to measure detection thresholds of otolith afferents using 1 Hz linear accelerations delivered along three cardinal axes. Direction detection thresholds were measured by comparing mean firing rates centered on response peak and trough (full-cycle thresholds) or by comparing peak/trough firing rates with spontaneous activity (half-cycle thresholds). Thresholds were similar for utricular and saccular afferents, as well as for lateral, fore/aft, and vertical motion directions. When computed along the preferred direction, full-cycle direction detection thresholds were 7.54 and 3.01 cm/s(2) for regular and irregular firing otolith afferents, respectively. Half-cycle thresholds were approximately double, with excitatory thresholds being half as large as inhibitory thresholds. The variability in threshold among afferents was directly related to neuronal gain and did not depend on spike count variance. The exact threshold values depended on both the time window used for spike count analysis and the filtering method used to calculate mean firing rate, although differences between regular and irregular afferent thresholds were independent of analysis parameters. The fact that minimum thresholds measured in macaque otolith afferents are of the same order of magnitude as human behavioral thresholds suggests that the vestibular periphery might determine the limit on our ability to detect or discriminate small differences in head movement, with little noise added during downstream processing.

  2. Renal afferents responsive to chemical and mechanical pelvic stimuli in the rabbit.

    PubMed

    Genovesi, S; Pieruzzi, F; Camisasca, P; Golin, R; Zanchetti, A; Stella, A

    1997-05-01

    1. Afferent nerve fibres sensitive to changes in the renal chemical environment have been found in the rat. To verify the existence of these fibres in the rabbit and their response pattern, afferent renal nerve activity was recorded during pelvic perfusions with NaCl solutions at different concentrations. 2. The experiments were carried out in 13 anaesthetized rabbits. Arterial pressure from a femoral catheter and afferent renal nerve activity from the distal stump of a cut renal nerve bundle were recorded. Three catheters were inserted into the renal pelvis to measure pelvic pressure, to allow pelvic perfusions at constant rates and to drain pelvic fluids. 3. After a control period, the pelvis was perfused with physiological saline (0.14 mol/l for 2 min), followed by one of a series of solutions containing increasing concentrations of NaCl (0.5, 0.75, 1.0 and 1.5 mol/l for 2 min). Pelvic perfusion was performed both at a low (0.2 ml/min) and a high (0.8 ml/min) flow rate for each solution tested. 4. In all animals arterial pressure was not modified during pelvic perfusions. Physiological saline did not change afferent renal nerve activity at the low perfusion rate, but it significantly increased afferent renal nerve activity and pelvic pressure at the high rate. Hypertonic NaCl solutions caused progressive increases in afferent renal nerve activity at both perfusion rates, and these effects were larger at the high perfusion rate. 5. These data demonstrate, in the rabbit, the existence of renal afferent nerves sensitive to discrete changes in pelvic ionic or osmotic concentration. The neural response is enhanced when renal mechano- and chemo-receptors are simultaneously activated.

  3. A dural lymphatic vascular system that drains brain interstitial fluid and macromolecules.

    PubMed

    Aspelund, Aleksanteri; Antila, Salli; Proulx, Steven T; Karlsen, Tine Veronica; Karaman, Sinem; Detmar, Michael; Wiig, Helge; Alitalo, Kari

    2015-06-29

    The central nervous system (CNS) is considered an organ devoid of lymphatic vasculature. Yet, part of the cerebrospinal fluid (CSF) drains into the cervical lymph nodes (LNs). The mechanism of CSF entry into the LNs has been unclear. Here we report the surprising finding of a lymphatic vessel network in the dura mater of the mouse brain. We show that dural lymphatic vessels absorb CSF from the adjacent subarachnoid space and brain interstitial fluid (ISF) via the glymphatic system. Dural lymphatic vessels transport fluid into deep cervical LNs (dcLNs) via foramina at the base of the skull. In a transgenic mouse model expressing a VEGF-C/D trap and displaying complete aplasia of the dural lymphatic vessels, macromolecule clearance from the brain was attenuated and transport from the subarachnoid space into dcLNs was abrogated. Surprisingly, brain ISF pressure and water content were unaffected. Overall, these findings indicate that the mechanism of CSF flow into the dcLNs is directly via an adjacent dural lymphatic network, which may be important for the clearance of macromolecules from the brain. Importantly, these results call for a reexamination of the role of the lymphatic system in CNS physiology and disease.

  4. A dural lymphatic vascular system that drains brain interstitial fluid and macromolecules

    PubMed Central

    Aspelund, Aleksanteri; Antila, Salli; Proulx, Steven T.; Karlsen, Tine Veronica; Karaman, Sinem; Detmar, Michael; Wiig, Helge

    2015-01-01

    The central nervous system (CNS) is considered an organ devoid of lymphatic vasculature. Yet, part of the cerebrospinal fluid (CSF) drains into the cervical lymph nodes (LNs). The mechanism of CSF entry into the LNs has been unclear. Here we report the surprising finding of a lymphatic vessel network in the dura mater of the mouse brain. We show that dural lymphatic vessels absorb CSF from the adjacent subarachnoid space and brain interstitial fluid (ISF) via the glymphatic system. Dural lymphatic vessels transport fluid into deep cervical LNs (dcLNs) via foramina at the base of the skull. In a transgenic mouse model expressing a VEGF-C/D trap and displaying complete aplasia of the dural lymphatic vessels, macromolecule clearance from the brain was attenuated and transport from the subarachnoid space into dcLNs was abrogated. Surprisingly, brain ISF pressure and water content were unaffected. Overall, these findings indicate that the mechanism of CSF flow into the dcLNs is directly via an adjacent dural lymphatic network, which may be important for the clearance of macromolecules from the brain. Importantly, these results call for a reexamination of the role of the lymphatic system in CNS physiology and disease. PMID:26077718

  5. Multivalent Vaccine for Lymphatic Filariasis

    PubMed Central

    Samykutty, Abhilash; Dakshinamoorthy, Gajalakshmi; Kalyanasundaram, Ramaswamy

    2011-01-01

    Lymphatic filariasis is a mosquito borne parasitic infection that cause severe economic burden in several parts of the world. Currently there is no vaccine available to prevent this infection in human. Multidrug therapy is effective, however, requires annual treatment and there is significant concern of drug resistance. In this manuscript we describe development of a multivalent DNA based vaccine comprising BmALT-2 and BmHSP antigens of lymphatic filariasis. Challenge experiments using third stage infective larvae of Brugia malayi in a mouse model suggested that nearly 90% protection can be achieved using the multivalent formulation in a DNA prime protein boost approach. The vaccination regimen induced significant IgG antibody responses and ELISPOT analysis for secreted cytokines from the spleen cells of vaccinated animals showed that these cells produce significant amount of IL-4. Results from this study thus show that a multivalent vaccine formulation of BmALT-2 and BmHSP is an excellent vaccine for lymphatic filariasis and significant protection can be achieved against a challenge infection with B. malayi in a mouse model. PMID:21709765

  6. Multivalent Vaccine for Lymphatic Filariasis.

    PubMed

    Samykutty, Abhilash; Dakshinamoorthy, Gajalakshmi; Kalyanasundaram, Ramaswamy

    2010-01-01

    Lymphatic filariasis is a mosquito borne parasitic infection that cause severe economic burden in several parts of the world. Currently there is no vaccine available to prevent this infection in human. Multidrug therapy is effective, however, requires annual treatment and there is significant concern of drug resistance. In this manuscript we describe development of a multivalent DNA based vaccine comprising BmALT-2 and BmHSP antigens of lymphatic filariasis. Challenge experiments using third stage infective larvae of Brugia malayi in a mouse model suggested that nearly 90% protection can be achieved using the multivalent formulation in a DNA prime protein boost approach. The vaccination regimen induced significant IgG antibody responses and ELISPOT analysis for secreted cytokines from the spleen cells of vaccinated animals showed that these cells produce significant amount of IL-4. Results from this study thus show that a multivalent vaccine formulation of BmALT-2 and BmHSP is an excellent vaccine for lymphatic filariasis and significant protection can be achieved against a challenge infection with B. malayi in a mouse model.

  7. Lymphatic Imaging: Focus on Imaging Probes

    PubMed Central

    Niu, Gang; Chen, Xiaoyuan

    2015-01-01

    In view of the importance of sentinel lymph nodes (SLNs) in tumor staging and patient management, sensitive and accurate imaging of SLNs has been intensively explored. Along with the advance of the imaging technology, various contrast agents have been developed for lymphatic imaging. In this review, the lymph node imaging agents were summarized into three groups: tumor targeting agents, lymphatic targeting agents and lymphatic mapping agents. Tumor targeting agents are used to detect metastatic tumor tissue within LNs, lymphatic targeting agents aim to visualize lymphatic vessels and lymphangionesis, while lymphatic mapping agents are mainly for SLN detection during surgery after local administration. Coupled with various signal emitters, these imaging agents work with single or multiple imaging modalities to provide a valuable way to evaluate the location and metastatic status of SLNs. PMID:25897334

  8. The Lymphatic Immune Response Induced by the Adjuvant AS01: A Comparison of Intramuscular and Subcutaneous Immunization Routes.

    PubMed

    Neeland, Melanie R; Shi, Wei; Collignon, Catherine; Taubenheim, Nadine; Meeusen, Els N T; Didierlaurent, Arnaud M; de Veer, Michael J

    2016-10-01

    The liposome-based adjuvant AS01 incorporates two immune stimulants, 3-O-desacyl-4'-monophosphoryl lipid A and the saponin QS-21. AS01 is under investigation for use in several vaccines in clinical development. i.m. injection of AS01 enhances immune cell activation and dendritic cell (DC) Ag presentation in the local muscle-draining lymph node. However, cellular and Ag trafficking in the lymphatic vessels that connect an i.m. injection site with the local lymph node has not been investigated. The objectives of this study were: 1) to quantify the in vivo cellular immune response induced by AS01 in an outbred ovine model, 2) to develop a lymphatic cannulation model that directly collects lymphatic fluid draining the muscle, and 3) to investigate the function of immune cells entering and exiting the lymphatic compartments after s.c. or i.m. vaccination with AS01 administered with hepatitis B surface Ag (HBsAg). We show that HBsAg-AS01 induces a distinct immunogenic cellular signature within the blood and draining lymphatics following both immunization routes. We reveal that MHCII(high) migratory DCs, neutrophils, and monocytes can acquire Ag within muscle and s.c. afferent lymph, and that HBsAg-AS01 uniquely induces the selective migration of Ag-positive neutrophils, monocytes, and an MHCII(high) DC-like cell type out of the lymph node via the efferent lymphatics that may enhance Ag-specific immunity. We report the characterization of the immune response in the lymphatic network after i.m. and s.c. injection of a clinically relevant vaccine, all in real time using a dose and volume comparable with that administered in humans. PMID:27549170

  9. Effects of renal lymphatic occlusion and venous constriction on renal function.

    PubMed Central

    Stolarczyk, J.; Carone, F. A.

    1975-01-01

    The effects of renal lymphatic occlusion or increased lymph flow due to renal vein constriction on renal function were investigated in rats. In each experiment, the renal lymphatics or vein of the left kidney were occluded or constricted and the right kidney served as a control. Occlusion of renal lymphatics caused renal enlargement, no change in glomerular filtration rate, a marked increase in urine flow and solute excretion without any change in urine osmolality, and enhanced urinary loss of urea, potassium, sodium and ammonium. Urea concentrations in medullary and papillary tissues were significantly elevated. Renal vein constriction caused renal enlargement and a marked drop in glomerular filtration rate, urine volume, urine osmolality and solute excretion. tissue concentrations of urea and potassium were decreased in the medulla and papilla and total tissue solute was significantly decreased in the papilla. The data indicate that in the rat, renal lymphatic occlusion traps urea in the medulla and induces a urea diuresis resulting in a large flow of normally concentrated urine. On the other hand, increased lymph flow secondary to renal vein constriction decreases medullary urea and potassium concentrations and papillary osmolality. These changes and the reduced glomerular filtration rate result in a small flow if dilute urine. Thus both renal lymphatic occlusion and enhanced lymph flow have a significant effect on renal function. Images Fig 1 PMID:1122006

  10. The discovery of the synovial lymphatic stomata and lymphatic reabsorption in knee effusion.

    PubMed

    Ping, Zepeng; Jiang, Tingting; Wang, Chong; Chen, Zhongyi; Chen, Zhongliang; Wang, Jiaxiong; Wang, Li; Wang, Beibei; Xu, Dandan; Liu, Changming; Li, Zhongjie; Li, Ji-Cheng

    2015-06-01

    To illustrate the mechanism of lymphatic reabsorption in knee joint effusion. The current investigation employed transmission electron microscopy (TEM) and scanning electron microscopy (SEM) techniques to reveal the ultrastructure of the knee synovial membrane in New Zealand rabbits and human. Ultrastructural changes of the synovial lymphatic stomata were observed by using trypan blue absorption and sodium hydroxide (NaOH) digestion methods, and the animal models of synovitis. New Zealand rabbits and human synovial membranes were composed of two types of synovial cells: type A and type B. No lymphatic stomata were found among type A synovial cells, whereas lymphatic stomata with the diameters ranging 0.74-3.26 µm were found in type B synovial cells, and some stomata were closed. After the NaOH digestion, a number of sieve pores, similar to lymphatic stomata in size and shape, were observed in the dense fibrous connective tissue underneath the type B synovial cells. After injecting trypan blue into the rabbit knee joint cavity, absorption of trypan blue through the lymphatic stomata was observed, suggesting the absorption function of the synovial lymphatic stomata. In the rabbit knee joint synovitis models, the synovial lymphatic stomata diameter enlarged. Some macrophages migrated from the lymphatic stomata, indicating that the synovial lymphatic stomata were involved in the joint effusion absorption and inflammatory response. Our study is the first to report the existence of synovial lymphatic stomata in the New Zealand rabbits and human knee joints. Lymphatic stomata may have an important role in the reabsorption of joint effusion.

  11. Acute neonatal presentation of a lymphatic malformation

    PubMed Central

    Tang, Chee Yan; Wijnen, M; Sambeeck van, S J; Halbertsma, F J J

    2013-01-01

    Oropharyngeal lymphatic malformations usually present with a mass either at birth or in the first 2 years of life. Rarely, lymphatic malformations present with extremely progressive respiratory problems shortly after birth, and usually occur in cases which have remained undetected in the absence of antenatal ultrasound. We report the case of a newborn that required tracheostomy and gastrostomy due to a rapidly expansive lymphatic malformation. MRI showed multilocular microcystic lymphatic malformation. Intralesional bleomycin injections proved to be successful in this patient. A short review of epidemiology, clinical manifestation and treatment is given. PMID:23907961

  12. Patterns of saccular afferent innervation in sciaenids.

    PubMed

    Selckmann, G M; Ramcharitar, J

    2013-09-01

    In this study, saccular afferent arborization patterns in Atlantic croaker Micropogonias undulatus, red drum Sciaenops ocellatus and spot Leiostomus xanthurus were characterized. Leiostomus xanthurus showed the simplest configuration while M. undulatus displayed the most complex. In addition, hair-cell densities at sites sampled along the rostro-caudal axis of the saccular epithelia correlated with the observed patterns of arborization. PMID:23991887

  13. Characterization of internodal collecting lymphatic vessel function after surgical removal of an axillary lymph node in mice.

    PubMed

    Kwon, Sunkuk; Price, Roger E

    2016-04-01

    Secondary lymphedema is an acquired lymphatic disorder, which occurs because of damage to the lymphatic system from surgery and/or radiation therapy for cancer treatment. However, it remains unknown how post-nodal collecting lymphatic vessels (CLVs) draining to the surgical wound area change in response to lymphadenectomy. We investigated functional and architectural changes of inguinal-to-axillary internodal CLVs (ICLVs) in mice after a single axillary LN (ALN) dissection using near-infrared fluorescence imaging. Our data showed no lymph flow in the ICLVs draining from the inguinal LN (ILN) at 2 days post-surgery. External compression enabled visualization of a small segment of contractile fluorescent ICLVs, but not all the way to the axillary region. At day 6, abnormal lymphatic drainage patterns, including lateral and retrograde lymph flow via vessels branching off the ICLVs were observed, which started to disappear beginning 9 days after surgery. The administration of vascular endothelial growth factor (VEGF)-C into the wound increased resolution of altered lymphatic drainage. Lymphatic drainage from the base of the tail to the ILN did not significantly change over time. These results demonstrate that lymph flow in the CLVs is dramatically affected by a LN dissection and long-term interruption of lymph flow might cause CLV dysfunction and thus contribute to chronic lymphatic disorders. PMID:27446639

  14. Interplay of mechanotransduction, FOXC2, connexins, and calcineurin signaling in lymphatic valve formation.

    PubMed

    Sabine, Amélie; Petrova, Tatiana V

    2014-01-01

    The directional flow of lymph is maintained by hundreds of intraluminal lymphatic valves. Lymphatic valves are crucial to prevent lymphedema, accumulation of fluid in the tissues, and to ensure immune surveillance; yet, the mechanisms of valve formation are only beginning to be elucidated. In this chapter, we will discuss the main steps of lymphatic valve morphogenesis, the important role of mechanotransduction in this process, and the genetic program regulated by the transcription factor Foxc2, which is indispensable for all steps of valve development. Failure to form mature collecting lymphatic vessels and valves causes the majority of postsurgical lymphedema, e.g., in breast cancer patients. Therefore, this knowledge will be useful for diagnostics and development of better treatments of secondary lymphedema.

  15. Short-latency afferent inhibition determined by the sensory afferent volley.

    PubMed

    Bailey, Aaron Z; Asmussen, Michael J; Nelson, Aimee J

    2016-08-01

    Short-latency afferent inhibition (SAI) is characterized by the suppression of the transcranial magnetic stimulation motor evoked potential (MEP) by the cortical arrival of a somatosensory afferent volley. It remains unknown whether the magnitude of SAI reflects changes in the sensory afferent volley, similar to that observed for somatosensory evoked potentials (SEPs). The present study investigated stimulus-response relationships between sensory nerve action potentials (SNAPs), SAI, and SEPs and their interrelatedness. Experiment 1 (n = 23, age 23 ± 1.5 yr) investigated the stimulus-response profile for SEPs and SAI in the flexor carpi radialis muscle after stimulation of the mixed median nerve at the wrist using ∼25%, 50%, 75%, and 100% of the maximum SNAP and at 1.2× and 2.4× motor threshold (the latter equated to 100% of the maximum SNAP). Experiment 2 (n = 20, age 23.1 ± 2 yr) probed SEPs and SAI stimulus-response relationships after stimulation of the cutaneous digital nerve at ∼25%, 50%, 75%, and 100% of the maximum SNAP recorded at the elbow. Results indicate that, for both nerve types, SAI magnitude is dependent on the volume of the sensory afferent volley and ceases to increase once all afferent fibers within the nerve are recruited. Furthermore, for both nerve types, the magnitudes of SAI and SEPs are related such that an increase in excitation within somatosensory cortex is associated with an increase in the magnitude of afferent-induced MEP inhibition. PMID:27226451

  16. Effects of dynamic shear and transmural pressure on wall shear stress sensitivity in collecting lymphatic vessels.

    PubMed

    Kornuta, Jeffrey A; Nepiyushchikh, Zhanna; Gasheva, Olga Y; Mukherjee, Anish; Zawieja, David C; Dixon, J Brandon

    2015-11-01

    Given the known mechanosensitivity of the lymphatic vasculature, we sought to investigate the effects of dynamic wall shear stress (WSS) on collecting lymphatic vessels while controlling for transmural pressure. Using a previously developed ex vivo lymphatic perfusion system (ELPS) capable of independently controlling both transaxial pressure gradient and average transmural pressure on an isolated lymphatic vessel, we imposed a multitude of flow conditions on rat thoracic ducts, while controlling for transmural pressure and measuring diameter changes. By gradually increasing the imposed flow through a vessel, we determined the WSS at which the vessel first shows sign of contraction inhibition, defining this point as the shear stress sensitivity of the vessel. The shear stress threshold that triggered a contractile response was significantly greater at a transmural pressure of 5 cmH2O (0.97 dyne/cm(2)) than at 3 cmH2O (0.64 dyne/cm(2)). While contraction frequency was reduced when a steady WSS was applied, this inhibition was reversed when the applied WSS oscillated, even though the mean wall shear stresses between the conditions were not significantly different. When the applied oscillatory WSS was large enough, flow itself synchronized the lymphatic contractions to the exact frequency of the applied waveform. Both transmural pressure and the rate of change of WSS have significant impacts on the contractile response of lymphatic vessels to flow. Specifically, time-varying shear stress can alter the inhibition of phasic contraction frequency and even coordinate contractions, providing evidence that dynamic shear could play an important role in the contractile function of collecting lymphatic vessels.

  17. Organization and developmental aspects of lymphatic vessels.

    PubMed

    Ohtani, Osamu; Ohtani, Yuko

    2008-05-01

    The lymphatic system plays important roles in maintaining tissue fluid homeostasis, immune surveillance of the body, and the taking up dietary fat and fat-soluble vitamins A, D, E and K. The lymphatic system is involved in many pathological conditions, including lymphedema, inflammatory diseases, and tumor dissemination. A clear understanding of the organization of the lymphatic vessels in normal conditions would be critically important to develop new treatments for diseases involving the lymphatic vascular system. Therefore, the present paper reviews the organization of the lymphatic vascular system of a variety of organs, including the thyroid gland, lung and pleura, small intestine, cecum and colon in the rat, the diaphragm in the rat, monkey, and human, Peyer's patches and the appendix in the rabbit, and human tonsils. Methods employed include scanning electron microscopy of lymphatic corrosion casts and tissues with or without treatment of alkali maceration technique, transmission electron microscopy of intact tissues, confocal microscopy in conjunction with immunohistochemistry to some lymphatic-specific markers (i.e., LYVE-1 and VEGFR-3), and light microscopy in conjunction with enzyme-histochemistry to 5'-nucleotidase. Some developmental aspects of the lymphatic vessels and lymphedema are also discussed.

  18. Lymphatic endothelial lineage assemblage during corneal lymphangiogenesis

    PubMed Central

    Connor, Alicia L.; Kelley, Philip M.; Tempero, Richard M.

    2015-01-01

    Post natal inflammatory lymphangiogenesis presumably requires precise regulatory processes to properly assemble proliferating lymphatic endothelial cells (LECs). The specific mechanisms that regulate the assembly of LECs during new lymphatic vessel synthesis are unclear. Dynamic endothelial shuffling and rearrangement has been proposed as a mechanism of blood vessel growth. We developed genetic lineage tracing strategies using an inductive transgenic technology to track the fate of entire tandem dimer tomato positive (tdT) lymphatic vessels or small, in some cases clonal, populations of LECs. We coupled this platform with a suture induced mouse model of corneal lymphangiogenesis and used different analytic microscopy techniques including serial live imaging to study the spatial properties of proliferating tdT+ LEC progenies. LEC precursors and their progeny expanded from the corneal limbal lymphatic vessel and were assembled contiguously to comprise a subunit within a new lymphatic vessel. VE-cadherin blockade induced morphologic abnormalities in newly synthesized lymphatic vessels, but did not disrupt the tdT+ lymphatic endothelial lineage assembly. Analysis of this static and dynamic data based largely on direct in vivo observations supports a model of lymphatic endothelial lineage assemblage during corneal inflammatory lymphangiogenesis. PMID:26658452

  19. Lymphatic endothelial lineage assemblage during corneal lymphangiogenesis.

    PubMed

    Connor, Alicia L; Kelley, Philip M; Tempero, Richard M

    2016-03-01

    Postnatal inflammatory lymphangiogenesis presumably requires precise regulatory processes to properly assemble proliferating lymphatic endothelial cells (LECs). The specific mechanisms that regulate the assembly of LECs during new lymphatic vessel synthesis are unclear. Dynamic endothelial shuffling and rearrangement has been proposed as a mechanism of blood vessel growth. We developed genetic lineage-tracing strategies using an inductive transgenic technology to track the fate of entire tandem dimer tomato-positive (tdT) lymphatic vessels or small, in some cases clonal, populations of LECs. We coupled this platform with a suture-induced mouse model of corneal lymphangiogenesis and used different analytic microscopy techniques including serial live imaging to study the spatial properties of proliferating tdT(+) LEC progenies. LEC precursors and their progeny expanded from the corneal limbal lymphatic vessel and were assembled contiguously to comprise a subunit within a new lymphatic vessel. VE-cadherin blockade induced morphologic abnormalities in newly synthesized lymphatic vessels, but did not disrupt the tdT(+) lymphatic endothelial lineage assembly. Analysis of this static and dynamic data based largely on direct in vivo observations supports a model of lymphatic endothelial lineage assemblage during corneal inflammatory lymphangiogenesis. PMID:26658452

  20. Pain processing by spinal microcircuits: afferent combinatorics.

    PubMed

    Prescott, Steven A; Ratté, Stéphanie

    2012-08-01

    Pain, itch, heat, cold, and touch represent different percepts arising from somatosensory input. How stimuli give rise to these percepts has been debated for over a century. Recent work supports the view that primary afferents are highly specialized to transduce and encode specific stimulus modalities. However, cross-modal interactions (e.g. inhibition or exacerbation of pain by touch) support convergence rather than specificity in central circuits. We outline how peripheral specialization together with central convergence could enable spinal microcircuits to combine inputs from distinctly specialized, co-activated afferents and to modulate the output signals thus formed through computations like normalization. These issues will be discussed alongside recent advances in our understanding of microcircuitry in the superficial dorsal horn.

  1. Pain processing by spinal microcircuits: afferent combinatorics.

    PubMed

    Prescott, Steven A; Ratté, Stéphanie

    2012-08-01

    Pain, itch, heat, cold, and touch represent different percepts arising from somatosensory input. How stimuli give rise to these percepts has been debated for over a century. Recent work supports the view that primary afferents are highly specialized to transduce and encode specific stimulus modalities. However, cross-modal interactions (e.g. inhibition or exacerbation of pain by touch) support convergence rather than specificity in central circuits. We outline how peripheral specialization together with central convergence could enable spinal microcircuits to combine inputs from distinctly specialized, co-activated afferents and to modulate the output signals thus formed through computations like normalization. These issues will be discussed alongside recent advances in our understanding of microcircuitry in the superficial dorsal horn. PMID:22409855

  2. Development, plasticity and modulation of visceral afferents

    PubMed Central

    Christianson, Julie A.; Bielefeldt, Klaus; Altier, Christophe; Cenac, Nicolas; Davis, Brian M.; Gebhart, Gerald F.; High, Karin W.; Kollarik, Marian; Randich, Alan; Undem, Brad; Vergnolle, Nathalie

    2010-01-01

    Visceral pain is the most common reason for doctor visits in the US. Like somatic pain, virtually all visceral pain sensations begin with the activation of primary sensory neurons innervating the viscera and/or the blood vessels associated with these structures. Visceral afferents also play a central role in tissue homeostasis. Recent studies show that in addition to monitoring the state of the viscera, they perform efferent functions through the release of small molecules (e.g. peptides like CGRP) that can drive inflammation, thereby contributing to the development of visceral pathologies (e.g. diabetes Razavi, R., Chan, Y., Afifiyan, F.N., Liu, X.J., Wan, X., Yantha, J., Tsui, H., Tang, L., Tsai, S., Santamaria, P., Driver, J.P., Serreze, D., Salter, M.W., Dosch, H.M., 2006. TRPV1+ sensory neurons control beta cell stress and islet inflammation in autoimmune diabetes, Cell 127 1123–1135). Visceral afferents are heterogeneous with respect to their anatomy, neurochemistry and function. They are also highly plastic in that their cellular environment continuously influences their response properties. This plasticity makes them susceptible to long-term changes that may contribute significantly to the development of persistent pain states such as those associated with irritable bowel syndrome, pancreatitis, and visceral cancers. This review examines recent insights into visceral afferent anatomy and neurochemistry and how neonatal insults can affect the function of these neurons in the adult. New approaches to the treatment of visceral pain, which focus on primary afferents, will also be discussed. PMID:19150371

  3. Label-free optical imaging of lymphatic vessels within tissue beds in vivo

    PubMed Central

    Yousefi, Siavash; Zhi, Zhongwei; Wang, Ruikang K.

    2015-01-01

    Lymphatic vessels are a part of circulatory system in vertebrates that maintain tissue fluid homeostasis and drain excess fluid and large cells that cannot easily find their way back into venous system. Due to the lack of non-invasive monitoring tools, lymphatic vessels are known as forgotten circulation. However, lymphatic system plays an important role in diseases such as cancer and inflammatory conditions. In this paper, we start to briefly review the current existing methods for imaging lymphatic vessels, mostly involving dye/targeting cell injection. We then show the capability of optical coherence tomography (OCT) for label-free non-invasive in vivo imaging of lymph vessels and nodes. One of the advantages of using OCT over other imaging modalities is its ability to assess label-free blood flow perfusion that can be simultaneously observed along with lymphatic vessels for imaging the microcirculatory system within tissue beds. Imaging the microcirculatory system including blood and lymphatic vessels can be utilized for imaging and better understanding pathologic mechanisms and treatment technique development in some critical diseases such as inflammation, malignant cancer angiogenesis and metastasis. PMID:25642129

  4. Lymphoedema: Pathophysiology and management in resource-poor settings - relevance for lymphatic filariasis control programmes

    PubMed Central

    Vaqas, Babar; Ryan, Terence J

    2003-01-01

    Low cost reduction of morbidity in lymphoedema is an essential goal in the management of lymphatic filariasis. This review emphasises the role of movement and elevation, and refers to the literature on the effects of these on the venous and lymphatic system. The patient with lymphoedema becomes increasingly immobile and the affected limb is often in a permanently dependent position causing venous hypertension and resultant overloading of the failing lymphatics. The evidence that breathing exercises are important for reducing venous hypertension and inducing lymphatic flow is discussed. The contribution of a damaged epidermis to lymphatic failure is emphasised. Loss of barrier function encourages penetration of bacteria and stimulates repair mechanisms that generate cytokines, which, in turn lead to inflammation. Management programmes that improve the health of the epidermis play a part in reducing lymphatic load. In taking morbidity management of lymphoedema into the general health services there are benefits in promoting skin hygiene and self-help regimes that can ameliorate many diseases along with lymphoedema. PMID:12685942

  5. Integrin Alpha 9 Blockade Suppresses Lymphatic Valve Formation and Promotes Transplant Survival

    PubMed Central

    Kang, Gyeong Jin; Truong, Tan; Huang, Eric; Su, Valerie; Ge, Shaokui; Chen, Lu

    2016-01-01

    Purpose The lymphatic pathway mediates transplant rejection. We recently reported that lymphatic vessels develop luminal valves in the cornea during lymphangiogenesis, and these valves express integrin alpha 9 (Itga-9) and play a critical role in directing lymph flow. In this study, we used an allogeneic corneal transplantation model to investigate whether Itga-9 blockade could suppress valvulogenesis after transplantation, and how this effect would influence the outcomes of the transplants. Methods Orthotopic corneal transplantation was performed between fully mismatched C57BL/6 (donor) and BALB/c (recipient) mice. The recipients were randomized to receive subconjunctival injections of either Itga-9 blocking antibody or isotype control twice a week for 8 weeks. Corneal grafts were assessed in vivo by ophthalmic slit-lamp biomicroscopy and analyzed using Kaplan-Meier survival curves. Additionally, whole-mount full-thickness corneas were evaluated ex vivo by immunofluorescent microscopy on both lymphatic vessels and valves. Results Anti–Itga-9 treatment suppressed lymphatic valvulogenesis after transplantation. Our treatment did not affect lymphatic vessel formation or their nasal polarized distribution in the cornea. More importantly, Itga-9 blockade led to a significant promotion of graft survival. Conclusions Lymphatic valvulogenesis is critically involved in transplant rejection. Itga-9 targeting may offer a new and effective strategy to interfere with the immune responses and promote graft survival. PMID:27806381

  6. Blockage of vibrissae afferents: I. Motor effects.

    PubMed

    Prchal, A; Albarracín, A L; Décima, E E

    2004-02-01

    In the past, it has been proposed that the rat vibrissae play an important role in other hand, postural abnormalities, muscle tone decreases and hypomotility after sensory organ destructions were proposed as evidence supporting the "level setting" or "tonic" hypothesis. This hypothesis postulates that afferent activity, besides its well know transductive functions, sets the excitability state of the central nervous system. We thought the vibrissal system to be a good model to dissect these two postulated roles because vibrissae trimming would annul the transductive function without affecting the integrity of nerve activity. Thus we compare the effects of trimming the whiskers with blocking the vibrissal afferent nerves on two types of motor behavior: activity in an open field and walking over a rope connecting two elevated platforms. We found that only vibrissal afferent blockage (both nerve section and local anaesthesia) produced severe failures in the motor performances studied. These effects could not be fully explained by the abolition of the vibrissae as a sensory modality because cutting the whiskers did not significantly affect the motor performance. These data are discussed in reference to a tonic or general excitatory function of sensory inputs upon the central nervous system. PMID:15143620

  7. [Morphogenesis, structure and properties of lymphatic vessels].

    PubMed

    Ratajska, Anna; Jankowska-Steifer, Ewa; Czarnowska, Elżbieta; Flaht, Aleksandra; Radomska-Leśniewska, Dorota

    2012-11-19

    In this paper, we present literature results related to structure and various manners of lymphatic vessel formation during embryonic development and in pathological events, such as tumorigenesis, wound healing, and other diseases. The functions of the lymphatic system include the collection of fluids that enter tissues from the circulation, absorption of lipids and lipid-soluble vitamins from the intestine and their subsequent transport, participation in antigen, dendritic cell, and lymphocyte migration. The lymphatic system is also a route for tumor cell and inflammatory cell transport. Native lymphatic capillaries differ from blood capillaries by having an irregular lumen, a discontinuous basement membrane, absence of pericytes, and a strong anchorage of their endothelial cells to the extracellular matrix via microfibrils built of emilin and fibrillin. Lymphatic endothelial cells express surface antigens such as Lyve-1, podoplanin, VEGFR3 (Flk4) and transcription factor Prox-1, as well as molecules which are common for blood endothelial cells and lymphatic endothelial cells (CD31, CD34, Flk-1, Tie-1, Tie-2, neuropilin 2). Lymphatic vessel formation during embryonic development starts with the occurrence of lymphatic sacs sprouting from systemic jugular veins and/or by co-option of lymphangioblasts or hematopoietic-derived cells. It can also proceed by dedifferentiation of venous endothelial cells after their detachment from the venous system, migration to the target places within the body and assembly in the lymphatic lumen. Mechanisms of lymphatic vessel formation during embryonic development and in pathological conditions, such as tumorigenesis, wound healing, and metastasis, is regulated by a plethora of growth factors and molecules, among which the most important are VEGF-C, VEGF-D, HGF, FGF, retinoic acid, IL-3, and IL-7. Macrophages and cells bearing CD45 phenotype seem to take part in the formation of lymphatics. Macrophages might act as a source of growth

  8. Antiedema effects of Siberian ginseng in humans and its molecular mechanism of lymphatic vascular function in vitro.

    PubMed

    Fukada, Kaedeko; Kajiya-Sawane, Mika; Matsumoto, Yuko; Hasegawa, Tatsuya; Fukaya, Yukitaka; Kajiya, Kentaro

    2016-07-01

    The lymphatic system in the skin plays a major role in tissue fluid homeostasis, in the afferent phase of the immune response, and in tumor metastasis. Although lymphangiogenic factors involved in embryonic development and the metastatic spread of tumor cells have been well studied, little is known about small-molecule compounds that activate lymphatic function, especially under physiological conditions. We hypothesized that the identification of a lymphatic-activating compound could provide a method for improving edema. Here, we show that Siberian ginseng (Eleutherococcus senticosus) and its component eleutheroside E induce phosphorylation of the endothelial-specific receptor Tie2 in vitro. The activation of Tie2 on lymphatic endothelial cells (LECs) is known to stabilize lymphatic vessels, so we examined the effects of Siberian ginseng on LECs. We found that Siberian ginseng induces the migration and cord formation of LECs. Permeability assays demonstrated that it stabilizes LECs by promoting the intercellular localization of vascular endothelial cadherin, which is an endothelium-specific cell-cell adhesion molecule involved in endothelial barrier function, and it induces the phosphorylation of endothelial nitric oxide synthase by LECs. These effects appear to be mediated by the activation of Tie2 in LECs. Finally, we investigated whether the consumption of Siberian ginseng powder improves edema in a 2-way, randomized, crossover study in 50 healthy female volunteers. Edema of the lower limbs was significantly attenuated at 2 and 4hours after ingestion as compared with the control group. Thus, we demonstrate that Siberian ginseng exerts its potent antiedema activity mainly by promoting lymphatic function. PMID:27333960

  9. Optimization of monoclonal antibody delivery via the lymphatics: the dose dependence

    SciTech Connect

    Steller, M.A.; Parker, R.J.; Covell, D.G.; Holton, O.D. 3d.; Keenan, A.M.; Sieber, S.M.; Weinstein, J.N.

    1986-04-01

    After interstitial injection in mice, antibody molecules enter local lymphatic vessels, flow with the lymph to regional lymph nodes, and bind to target antigens there. Compared with i.v. administration, delivery via the lymphatics provides a more efficient means for localizing antibody in lymph nodes. An IgG2a (36-7-5) directed against the murine class I major histocompatibility antigen H-2Kk has proved useful for studying the pharmacology of lymphatic delivery. At very low doses, most of the antibody remains at the injection site in Kk-positive animals. As the dose is progressively increased, most effective labeling occurs first in nodes proximal to the injection site and then in the next group of nodes along the lymphatic chain. At higher doses, antibody overflows the lymphatic system and enters the blood-stream via the thoracic duct and other lymphatic-venous connections. Once in the blood, antibody is rapidly cleared, apparently by binding to Kk-bearing cells. These findings indicate that the single-pass distribution of monoclonal antibodies in the lymphatics can be strongly dose dependent, a principle which may be of clinical significance in the improvement of immunolymphoscintigraphic imaging, especially with antibodies directed against normal and malignant lymphoid cells. Monoclonal antibodies directed against normal cell types in the lymph node may be useful for assessing the integrity of lymphatic chains by immunolymphoscintigraphy or, more speculatively, for altering the status of regional immune function. The results presented here indicate that a low or intermediate antibody dose may optimize the signal:noise ratio for imaging. In Kk-negative animals, the percentage of dose taken up in the major organs was essentially independent of the dose administered; there was no evidence for saturable sites of nonspecific binding.

  10. Dual-channel in-situ optical imaging system for quantifying lipid uptake and lymphatic pump function

    NASA Astrophysics Data System (ADS)

    Kassis, Timothy; Kohan, Alison B.; Weiler, Michael J.; Nipper, Matthew E.; Cornelius, Rachel; Tso, Patrick; Brandon Dixon, J.

    2012-08-01

    Nearly all dietary lipids are transported from the intestine to venous circulation through the lymphatic system, yet the mechanisms that regulate this process remain unclear. Elucidating the mechanisms involved in the functional response of lymphatics to changes in lipid load would provide valuable insight into recent implications of lymphatic dysfunction in lipid related diseases. Therefore, we sought to develop an in situ imaging system to quantify and correlate lymphatic function as it relates to lipid transport. The imaging platform provides the capability of dual-channel imaging of both high-speed bright-field video and fluorescence simultaneously. Utilizing post-acquisition image processing algorithms, we can quantify correlations between vessel pump function, lymph flow, and lipid concentration of mesenteric lymphatic vessels in situ. All image analysis is automated with customized LabVIEW virtual instruments; local flow is measured through lymphocyte velocity tracking, vessel contraction through measurements of the vessel wall displacement, and lipid uptake through fluorescence intensity tracking of an orally administered fluorescently labelled fatty acid analogue, BODIPY FL C16. This system will prove to be an invaluable tool for scientists studying intestinal lymphatic function in health and disease, and those investigating strategies for targeting the lymphatics with orally delivered drugs to avoid first pass metabolism.

  11. Dual-channel in-situ optical imaging system for quantifying lipid uptake and lymphatic pump function

    PubMed Central

    Kassis, Timothy; Kohan, Alison B.; Weiler, Michael J.; Nipper, Matthew E.; Cornelius, Rachel; Tso, Patrick

    2012-01-01

    Abstract. Nearly all dietary lipids are transported from the intestine to venous circulation through the lymphatic system, yet the mechanisms that regulate this process remain unclear. Elucidating the mechanisms involved in the functional response of lymphatics to changes in lipid load would provide valuable insight into recent implications of lymphatic dysfunction in lipid related diseases. Therefore, we sought to develop an in situ imaging system to quantify and correlate lymphatic function as it relates to lipid transport. The imaging platform provides the capability of dual-channel imaging of both high-speed bright-field video and fluorescence simultaneously. Utilizing post-acquisition image processing algorithms, we can quantify correlations between vessel pump function, lymph flow, and lipid concentration of mesenteric lymphatic vessels in situ. All image analysis is automated with customized LabVIEW virtual instruments; local flow is measured through lymphocyte velocity tracking, vessel contraction through measurements of the vessel wall displacement, and lipid uptake through fluorescence intensity tracking of an orally administered fluorescently labelled fatty acid analogue, BODIPY FL C16. This system will prove to be an invaluable tool for scientists studying intestinal lymphatic function in health and disease, and those investigating strategies for targeting the lymphatics with orally delivered drugs to avoid first pass metabolism. PMID:23224192

  12. Rapid Lymphatic Dissemination of Encapsulated Group A Streptococci via Lymphatic Vessel Endothelial Receptor-1 Interaction.

    PubMed

    Lynskey, Nicola N; Banerji, Suneale; Johnson, Louise A; Holder, Kayla A; Reglinski, Mark; Wing, Peter A C; Rigby, David; Jackson, David G; Sriskandan, Shiranee

    2015-09-01

    The host lymphatic network represents an important conduit for pathogen dissemination. Indeed, the lethal human pathogen group A streptococcus has a predilection to induce pathology in the lymphatic system and draining lymph nodes, however the underlying basis and subsequent consequences for disease outcome are currently unknown. Here we report that the hyaluronan capsule of group A streptococci is a crucial virulence determinant for lymphatic tropism in vivo, and further, we identify the lymphatic vessel endothelial receptor-1 as the critical host receptor for capsular hyaluronan in the lymphatic system. Interference with this interaction in vivo impeded bacterial dissemination to local draining lymph nodes and, in the case of a hyper-encapsulated M18 strain, redirected streptococcal entry into the blood circulation, suggesting a pivotal role in the manifestation of streptococcal infections. Our results reveal a novel function for bacterial capsular polysaccharide in directing lymphatic tropism, with potential implications for disease pathology.

  13. Rapid Lymphatic Dissemination of Encapsulated Group A Streptococci via Lymphatic Vessel Endothelial Receptor-1 Interaction

    PubMed Central

    Johnson, Louise A.; Holder, Kayla A.; Reglinski, Mark; Wing, Peter A. C.; Rigby, David; Jackson, David G.; Sriskandan, Shiranee

    2015-01-01

    The host lymphatic network represents an important conduit for pathogen dissemination. Indeed, the lethal human pathogen group A streptococcus has a predilection to induce pathology in the lymphatic system and draining lymph nodes, however the underlying basis and subsequent consequences for disease outcome are currently unknown. Here we report that the hyaluronan capsule of group A streptococci is a crucial virulence determinant for lymphatic tropism in vivo, and further, we identify the lymphatic vessel endothelial receptor-1 as the critical host receptor for capsular hyaluronan in the lymphatic system. Interference with this interaction in vivo impeded bacterial dissemination to local draining lymph nodes and, in the case of a hyper-encapsulated M18 strain, redirected streptococcal entry into the blood circulation, suggesting a pivotal role in the manifestation of streptococcal infections. Our results reveal a novel function for bacterial capsular polysaccharide in directing lymphatic tropism, with potential implications for disease pathology. PMID:26352587

  14. Minimally invasive method for determining the effective lymphatic pumping pressure in rats using near-infrared imaging.

    PubMed

    Nelson, Tyler S; Akin, Ryan E; Weiler, Michael J; Kassis, Timothy; Kornuta, Jeffrey A; Dixon, J Brandon

    2014-03-01

    The ability to quantify collecting vessel function in a minimally invasive fashion is crucial to the study of lymphatic physiology and the role of lymphatic pump function in disease progression. Therefore, we developed a highly sensitive, minimally invasive research platform for quantifying the pumping capacity of collecting lymphatic vessels in the rodent tail and forelimb. To achieve this, we have integrated a near-infrared lymphatic imaging system with a feedback-controlled pressure cuff to modulate lymph flow. After occluding lymphatic flow by inflating a pressure cuff on the limb or tail, we gradually deflate the cuff while imaging flow restoration proximal to the cuff. Using prescribed pressure applications and automated image processing of fluorescence intensity levels in the vessels, we were able to noninvasively quantify the effective pumping pressure (P(eff), pressure at which flow is restored after occlusion) and vessel emptying rate (rate of fluorescence clearance during flow occlusion) of lymphatics in the rat. To demonstrate the sensitivity of this system to changes in lymphatic function, a nitric oxide (NO) donor cream, glyceryl trinitrate ointment (GTNO), was applied to the tails. GTNO decreased P(eff) of the vessels by nearly 50% and the average emptying rate by more than 60%. We also demonstrate the suitability of this approach for acquiring measurements on the rat forelimb. Thus, this novel research platform provides the first minimally invasive measurements of P(eff) and emptying rate in rodents. This experimental platform holds strong potential for future in vivo studies that seek to evaluate changes in lymphatic health and disease.

  15. Nitric oxide permits hypoxia-induced lymphatic perfusion by controlling arterial-lymphatic conduits in zebrafish and glass catfish

    PubMed Central

    Dahl Ejby Jensen, Lasse; Cao, Renhai; Hedlund, Eva-Maria; Söll, Iris; Lundberg, Jon O.; Hauptmann, Giselbert; Steffensen, John Fleng; Cao, Yihai

    2009-01-01

    The blood and lymphatic vasculatures are structurally and functionally coupled in controlling tissue perfusion, extracellular interstitial fluids, and immune surveillance. Little is known, however, about the molecular mechanisms that underlie the regulation of bloodlymphatic vessel connections and lymphatic perfusion. Here we show in the adult zebrafish and glass catfish (Kryptopterus bicirrhis) that blood-lymphatic conduits directly connect arterial vessels to the lymphatic system. Under hypoxic conditions, arterial-lymphatic conduits (ALCs) became highly dilated and linearized by NO-induced vascular relaxation, which led to blood perfusion into the lymphatic system. NO blockage almost completely abrogated hypoxia-induced ALC relaxation and lymphatic perfusion. These findings uncover mechanisms underlying hypoxia-induced oxygen compensation by perfusion of existing lymphatics in fish. Our results might also imply that the hypoxia-induced NO pathway contributes to development of progression of pathologies, including promotion of lymphatic metastasis by modulating arterial-lymphatic conduits, in the mammalian system. PMID:19822749

  16. Afferent inhibition and the functional properties of neurons in the projection zone of the whiskers in the somatosensory cortex of the cat.

    PubMed

    Aleksandrov, A A

    2000-01-01

    The effects of afferent evoked inhibition on the functional properties of neurons in the whisker projection zone were studied in the cat brain. These investigations showed that afferent inhibition produced significant changes in the receptive fields of neurons, resulting in the induction of directional sensitivity. These data provide evidence for a defined topical ordering of intracortical inhibitory interactions. It is suggested that in natural conditions, movement of an object across the whisker field, resulting in sequential stimulation of the whiskers, results in sequential tuning of the detector properties of neurons receiving afferent flows from the whiskers. This process may form part of the mechanism for recognizing the direction of stimulus movement.

  17. Lymphatic Filariasis: Frequently Asked Questions (FAQs)

    MedlinePlus

    ... a parasitic disease caused by microscopic, thread-like worms. The adult worms only live in the human lymph system. The ... South America. You cannot get infected with the worms in the United States. How is lymphatic filariasis ...

  18. Afferent innervation patterns of the saccule in pigeons

    NASA Technical Reports Server (NTRS)

    Zakir, M.; Huss, D.; Dickman, J. D.

    2003-01-01

    The innervation patterns of vestibular saccular afferents were quantitatively investigated in pigeons using biotinylated dextran amine as a neural tracer and three-dimensional computer reconstruction. Type I hair cells were found throughout a large portion of the macula, with the highest density observed in the striola. Type II hair cells were located throughout the macula, with the highest density in the extrastriola. Three classes of afferent innervation patterns were observed, including calyx, dimorph, and bouton units, with 137 afferents being anatomically reconstructed and used for quantitative comparisons. Calyx afferents were located primarily in the striola, innervated a number of type I hair cells, and had small innervation areas. Most calyx afferent terminal fields were oriented parallel to the anterior-posterior axis and the morphological polarization reversal line. Dimorph afferents were located throughout the macula, contained fewer type I hair cells in a calyceal terminal than calyx afferents and had medium sized innervation areas. Bouton afferents were restricted to the extrastriola, with multi-branching fibers and large innervation areas. Most of the dimorph and bouton afferents had innervation fields that were oriented dorso-ventrally but were parallel to the neighboring reversal line. The organizational morphology of the saccule was found to be distinctly different from that of the avian utricle or lagena otolith organs and appears to represent a receptor organ undergoing evolutionary adaptation toward sensing linear motion in terrestrial and aerial species.

  19. CT demonstration of perirenal lymphatic cysts.

    PubMed

    De Maeyer, P; Baert, A L; Usewils, R; Wynants, P; De Pauw, A

    1982-01-01

    A case of perirenal lymphatic cysts demonstrated by computed tomography is reported. These lymphatic cysts, a histological subtype of lymphangiomata, are clearly visible as collections with clear fluid-type density surrounding both kidneys. The retroperitoneal localization of this rarity has been reported in the radiological literature, whereas, to our knowledge, the radiological demonstration of the perirenal localization has not. CT provides a unique method for direct radiological visualization of the cyst.

  20. Use of a PEG-conjugated bright near-infrared dye for functional imaging of rerouting of tumor lymphatic drainage after sentinel lymph node metastasis

    PubMed Central

    Proulx, Steven T.; Luciani, Paola; Christiansen, Ailsa; Karaman, Sinem; Blum, Katrin S.; Rinderknecht, Matthias; Leroux, Jean-Christophe; Detmar, Michael

    2013-01-01

    Tumor lymphangiogenesis promotes metastatic cancer spread to lymph nodes and beyond. However, the potential remodeling and functionality of tumor-draining lymphatic vessels has remained unclear. Thus, we aimed to develop non-invasive imaging methods for repeated quantitative imaging of lymphatic drainage and of contractile collecting lymphatic vessel function in mice, with colloidal near-infrared (NIR) tracers and a custom fluorescence stereomicroscope specially adapted for NIR sensitive imaging. Using these tools, we quantitatively determined pulse rates and valvular function of collecting lymphatic vessels with high resolution. Unexpectedly, we found that tumor-draining lymphatic vessels in a melanoma footpad model initially were dilated but remained functional, despite lower pulse rates. In two independent tumor models, impaired lymphatic function was detected once metastases were present in draining lymph nodes. Importantly, we found that lymphatic dysfunction, induced by metastatic tumor spread to sentinel lymph nodes, can lead to a rerouting of lymphatic flow away from the metastatic lymph node, via collateral lymphatic vessels, to alternate lymph nodes. These findings might have important clinical implications for the procedure of sentinel lymph node mapping that represents the standard of care for determining prognosis and treatment of melanoma and breast cancer patients. PMID:23566803

  1. Advances in Lymphatic Imaging and Drug Delivery

    SciTech Connect

    Nune, Satish K.; Gunda, Padmaja; Majeti, Bharat K.; Thallapally, Praveen K.; Laird, Forrest M.

    2011-09-10

    Cancer remains the second leading cause of death after heart disease in the US. While metastasized cancers such as breast, prostate, and colon are incurable, before their distant spread, these diseases will have invaded the lymphatic system as a first step in their progression. Hence, proper evaluation of the disease state of the lymphatics which drain a tumor site is crucial to staging and the formation of a treatment plan. Current lymphatic imaging modalities with visible dyes and radionucleotide tracers offer limited sensitivity and poor resolution; however, newer tools using nanocarriers, quantum dots, and magnetic resonance imaging promise to vastly improve the staging of lymphatic spread without needless biopsies. Concurrent with the improvement of lymphatic imaging agents, has been the development of drug carriers that can localize chemotherapy to the lymphatic system, thus improving the treatment of localized disease while minimizing the exposure of healthy organs to cytotoxic drugs. This review will focus on polymeric systems that have been developed for imaging and drug delivery to the lymph system, how these new devices improve upon current technologies, and where further improvement is needed.

  2. Platelets: Covert Regulators of Lymphatic Development

    PubMed Central

    Bertozzi, Cara C.; Hess, Paul R.; Kahn, Mark L.

    2010-01-01

    The field of platelet biology has rapidly expanded beyond the classical role of platelets in preventing blood loss and orchestrating clot formation. Despite the lack of transcriptional ability of these anuclear cell fragments, platelet function is now thought to encompass such diverse contexts as tissue repair, immune activation, primary tumor formation, and metastasis. Recent studies from multiple groups have turned the spotlight on an exciting new role for platelets in the formation of lymphatic vessels during embryonic development. Genetic experiments demonstrate that Podoplanin, a transmembrane protein expressed on lymphatic endothelial cells, engages the platelet CLEC-2 receptor when exposed to blood, leading to SYK-SLP-76-dependent platelet activation. When components of this pathway are disrupted, aberrant vascular connections form, resulting in blood-lymphatic mixing. Furthermore, platelet-null embryos manifest identical blood-lymphatic mixing. The identification of platelets as the critical cell type mediating blood-lymphatic vascular separation raises new questions in our understanding of lymphatic development and platelet biology. PMID:21071706

  3. Connexins in lymphatic vessel physiology and disease.

    PubMed

    Meens, Merlijn J; Sabine, Amélie; Petrova, Tatiana V; Kwak, Brenda R

    2014-04-17

    Connexins are transmembrane proteins that form gap junction- and hemi-channels. Once inserted into the membrane, hemi-channels (connexons) allow for diffusion of ions and small molecules (<1 kDa) between the extracellular space and the cytosol. Gap junction channels allow diffusion of similar molecules between the cytoplasms of adjacent cells. The expression and function of connexins in blood vessels has been intensely studied in the last few decades. In contrast, only a few studies paid attention to lymphatic vessels; convincing in vivo data with respect to expression patterns of lymphatic connexins and their functional roles have only recently begun to emerge. Interestingly, mutations in connexin genes have been linked to diseases of lymphatic vasculature, most notably primary and secondary lymphedema. This review summarizes the available data regarding lymphatic connexins. More specifically it addresses (i) early studies aimed at presence of gap junction-like structures in lymphatic vessels, (ii) more recent studies focusing on lymphatic connexins using genetically engineered mice, and (iii) results of clinical studies that have reported lymphedema-linked mutations in connexin genes.

  4. Role of RhoA in regulating the pump function of isolated lymphatics from hemorrhagic shock rats.

    PubMed

    Si, Yong-Hua; Niu, Chun-Yu; Zhao, Zi-Gang; Zhang, Li-Min; Zhang, Yu-Ping

    2013-07-01

    The aim of this present study was to examine changes in RhoA protein levels and the role in RhoA in lymphatic contractility and reactivity after hemorrhagic shock. Levels of RhoA and phospho-RhoA in lymphatic tissue isolated from hemorrhagic shock rats were measured, and the contractility and reactivity to substance P of lymphatics isolated from control rats and rats subjected to shock 0.5 and 2 h were determined with an isolated lymphatic perfusion system at a transmural pressure of 3 cmH2O. At the same time, lymphatics isolated from rats subjected to shock 0.5 and 2 h were incubated with agonists and antagonists of RhoA/Rho kinase signaling. Contractile frequency, end-diastolic and end-systolic diameter, and passive diameter were recorded and used to calculate lymphatic tonic index, contractile amplitude, and fractional pump flow. After stimulation with a gradient of substance P, the differences between the preadministration and postadministration values of contractile frequency, contractile amplitude, tonic index, and fractional pump flow were calculated to further assess lymphatic reactivity. RhoA protein levels were significantly increased at 0.5 h after shock but decreased at 2 and 3 h after shock; p-Rho levels were initially increased after shock and subsequently decreased. The contractility and reactivity of 0.5-h-shocked lymphatics were significantly reduced by the RhoA antagonist C3 transferase and the Rho kinase antagonist Y-27632. The RhoA agonist U-46619 increased the contractility and reactivity of 2-h-shocked lymphatics, whereas Y-27632 suppressed the effect of U-46619. Okadaic acid, an inhibitor of myosin light-chain phosphatase, had no effect on the contractility of 2-h-shocked lymphatics, but improved lymphatic reactivity. These results suggest that RhoA is involved in the modulation of lymphatic pump function during hemorrhagic shock and that its effects may be mediated by Rho kinase and MLCP.

  5. Role of lymphatic vasculature in regional and distant metastases.

    PubMed

    Podgrabinska, Simona; Skobe, Mihaela

    2014-09-01

    In cancer, lymphatic vasculature has been traditionally viewed only as a transportation system for metastatic cells. It has now become clear that lymphatics perform many additional functions which could influence cancer progression. Lymphangiogenesis, induced at the primary tumor site and at distant sites, potently augments metastasis. Lymphatic endothelial cells (LECs) control tumor cell entry and exit from the lymphatic vessels. LECs also control immune cell traffic and directly modulate adaptive immune responses. This review highlights advances in our understanding of the mechanisms by which lymphatic vessels, and in particular lymphatic endothelium, impact metastasis.

  6. The Lymphatic System in Disease Processes and Cancer Progression.

    PubMed

    Padera, Timothy P; Meijer, Eelco F J; Munn, Lance L

    2016-07-11

    Advances in our understanding of the structure and function of the lymphatic system have made it possible to identify its role in a variety of disease processes. Because it is involved not only in fluid homeostasis but also in immune cell trafficking, the lymphatic system can mediate and ultimately alter immune responses. Our rapidly increasing knowledge of the molecular control of the lymphatic system will inevitably lead to new and effective therapies for patients with lymphatic dysfunction. In this review, we discuss the molecular and physiological control of lymphatic vessel function and explore how the lymphatic system contributes to many disease processes, including cancer and lymphedema.

  7. CCR7 and IRF4-dependent dendritic cells regulate lymphatic collecting vessel permeability

    PubMed Central

    Ivanov, Stoyan; Scallan, Joshua P.; Kim, Ki-Wook; Werth, Kathrin; Johnson, Michael W.; Saunders, Brian T.; Wang, Peter L.; Kuan, Emma L.; Straub, Adam C.; Ouhachi, Melissa; Weinstein, Erica G.; Williams, Jesse W.; Briseño, Carlos; Colonna, Marco; Isakson, Brant E.; Gautier, Emmanuel L.; Förster, Reinhold; Davis, Michael J.; Zinselmeyer, Bernd H.

    2016-01-01

    Lymphatic collecting vessels direct lymph into and from lymph nodes (LNs) and can become hyperpermeable as the result of a previous infection. Enhanced permeability has been implicated in compromised immunity due to reduced flow of lymph and immune cells to LNs, which are the primary site of antigen presentation to T cells. Presently, very little is known about the molecular signals that affect lymphatic collecting vessel permeability. Here, we have shown that lymphatic collecting vessel permeability is controlled by CCR7 and that the chronic hyperpermeability of collecting vessels observed in Ccr7–/– mice is followed by vessel fibrosis. Reexpression of CCR7 in DCs, however, was sufficient to reverse the development of such fibrosis. IFN regulatory factor 4–positive (IRF4+) DCs constitutively interacted with collecting lymphatics, and selective ablation of this DC subset in Cd11c-Cre Irf4fl/fl mice also rendered lymphatic collecting vessels hyperpermeable and fibrotic. Together, our data reveal that CCR7 plays multifaceted roles in regulating collecting vessel permeability and fibrosis, with one of the key players being IRF4-dependent DCs. PMID:26999610

  8. Integrin-α9 is required for fibronectin matrix assembly during lymphatic valve morphogenesis

    PubMed Central

    Bazigou, Eleni; Xie, Sherry; Chen, Chun; Weston, Anne; Miura, Naoyuki; Sorokin, Lydia; Adams, Ralf; Muro, Andrés F.; Sheppard, Dean; Makinen, Taija

    2009-01-01

    Summary Dysfunction of lymphatic valves underlies human lymphedema, yet the process of valve morphogenesis is poorly understood. Here, we show that during embryogenesis lymphatic valve leaflet formation is initiated by upregulation of integrin-α9 expression and deposition of its ligand, fibronectin-EIIIA (FN-EIIIA), in the extracellular matrix. Endothelial cell specific deletion of Itga9 (encoding integrin-α9) in mouse embryos results in the development of rudimentary valve leaflets, characterized by disorganized FN matrix, short cusps and retrograde lymphatic flow. Similar morphological and functional defects are observed in mice lacking the EIIIA domain of FN. Mechanistically, we demonstrate that in primary human lymphatic endothelial cells the integrin-α9-EIIIA interaction directly regulates FN fibril assembly, which is essential for the formation of the extracellular matrix core of valve leaflets. Our findings reveal an important role for integrin-α9 signaling during lymphatic valve morphogenesis and implicate it as a candidate gene for primary lymphedema caused by valve defects. PMID:19686679

  9. Overcoming transport barriers for interstitial-, lymphatic-, and lymph node-targeted drug delivery

    PubMed Central

    Thomas, Susan N.; Schudel, Alex

    2015-01-01

    Despite drug formulation improving circulation times and targeting, efficacy is stymied by inadequate penetration into and retention within target tissues. This review highlights the barriers restricting delivery to the connective tissue interstitium, lymphatics, and lymph nodes as well as advances in engineering drug carriers to overcome these delivery challenges. Three-dimensional tissue physiology is discussed in the context of providing material design principles for delivery to these tissues; in particular the influence of interstitial and lymphatic flows as well as differential permeabilities of the blood and lymphatic capillaries. Key examples of materials with different characteristics developed to overcome these transport barriers are discussed as well as potential areas for further development. PMID:25745594

  10. Response properties of pigeon otolith afferents to linear acceleration

    NASA Technical Reports Server (NTRS)

    Si, X.; Angelaki, D. E.; Dickman, J. D.

    1997-01-01

    In the present study, the sensitivity to sinusoidal linear accelerations in the plane of the utricular macula was tested in afferents. The head orientation relative to the translation axis was varied in order to determine the head position that elicited the maximal and minimal responses for each afferent. The response gain and phase values obtained to 0.5-Hz and 2-Hz linear acceleration stimuli were then plotted as a function of head orientation and a modified cosine function was fit to the data. From the best-fit cosine function, the predicted head orientations that would produce the maximal and minimal response gains were estimated. The estimated maximum response gains to linear acceleration in the utricular plane for the afferents varied between 75 and 1420 spikes s-1 g-1. The mean maximal gains for all afferents to 0.5-Hz and 2-Hz sinusoidal linear acceleration stimuli were 282 and 367 spikes s-1 g-1, respectively. The minimal response gains were essentially zero for most units. The response phases always led linear acceleration and remained constant for each afferent, regardless of head orientation. These response characteristics indicate that otolith afferents are cosine tuned and behave as one-dimensional linear accelerometers. The directions of maximal sensitivity to linear acceleration for the afferents varied throughout the plane of the utricle; however, most vectors were directed out of the opposite ear near the interaural axis. The response dynamics of the afferents were tested using stimulus frequencies ranging between 0.25 Hz and 10 Hz (0.1 g peak acceleration). Across stimulus frequencies, most afferents had increasing gains and constant phase values. These dynamic properties for individual afferents were fit with a simple transfer function that included three parameters: a mechanical time constant, a gain constant, and a fractional order distributed adaptation operator.

  11. A study of the three-dimensional organization of the human diaphragmatic lymphatic lacunae and lymphatic drainage units.

    PubMed

    Li, J; Zhao, Z; Zhou, J; Yu, S

    1996-12-01

    The peritoneal stomata, lymphatic drainage units and subperitoneal terminal lymphatics, called lymphatic lacunae, form a specialized drainage system in the diaphragm, by which absorption of fluid in bulk, particles and cells is carried out in the peritoneal cavity. The aim of this study is to elucidate the three-dimensional organization and function of the subperitoneal lymphatic lacunae and lymphatic drainage units by using lymphatic casts in the scanning electron microscope (SEM), ODO (OsO4-DMSO-OsO4) freeze fracture, conventional SEM and the transmission electron microscope (TEM). The subperitoneal lymphatic lacuna is unique for its large size and its multiple morphology and can be recognized by its broad, flattened enlargement and the blind-ends of lymphatic vessels, from which extend numerous main lymphatic vessels and side branches. These lymphatic vessels communicate with each other and form a rich lymphatic plexus under the diaphragmatic peritoneum. Two layers of lymphatic networks, i.e. the subperitoneal plexus and the deeper plexus are found in the muscular portion. Only one layer is present in the tendinous portion of the human diaphragm. The lymphatic plexus is denser in the tendinous portion than that in the muscular portion. The lymphatic lacunae occur exclusively in the muscular portion of the human diaphragm. The lumina of lymphatic lacunae are separated from the peritoneal cavity by a barrier consisting of cuboidal mesothelial cells, endothelial cells of the lymphatic lacunae and intervening connective tissue forming a lymphatic drainage unit. All these three components of the lymphatic drainage unit abut upon each other, but are not linked by specialized junctions. The cuboidal mesothelial cells frequently extend valve-like cytoplasmic processes that bridge the subperitoneal channel and make give it a tortuous course. The fibrous layer of the connective tissue is arranged in fiber bundles and gives a three-dimensional network forming the floor of

  12. Effect of Microgravity on Afferent Innervation

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Presentations and publications are: (1) an audiovisual summary web presentation on results from SLM-MIR avian experiments. A color presentation summarizing results from the SLM-MIR and STS-29 avian experiments; (2) color threshold and ratio of S 100B MAP5, NF68/200, GABA and GAD; (3) chicken (Gallus domesticus) inner ear afferents; (4) microgravity in the STS-29 Space Shuttle Discovery affected the vestibular system of chick embryos; (5) expression of S 100B in sensory and secretory cells of the vertebrate inner ear; (6) otoconia biogenesis, phylogeny, composition and functional attributes;(7) the glycan keratin sulfate in inner ear crystals; (8) elliptical-P cells in the avian perilymphatic interface of the tegmentum vasculosum; and (9) LAMP2c and S100B upregulation in brain stem after VIIIth nerve deafferentation.

  13. Chicken (Gallus domesticus) inner ear afferents

    NASA Technical Reports Server (NTRS)

    Hara, H.; Chen, X.; Hartsfield, J. F.; Hara, J.; Martin, D.; Fermin, C. D.

    1998-01-01

    Neurons from the vestibular (VG) and the statoacoustic (SAG) ganglion of the chick (Gallus domesticus) were evaluated histologically and morphometrically. Embryos at stages 34 (E8 days), 39 (E13 days) and 44 (E18 days) were sacrificed and temporal bones microdissected. Specimens were embedded in JB-4 methacrylate plastic, and stained with a mixture of 0.2% toluidine blue (TB) and 0.1% basic Fuschin in 25% ethanol or with a mixture of 2% TB and 1% paraphenylenediamine (PDA) for axon and myelin measurement study. Images of the VIIIth nerve were produced by a V150 (R) color imaging system and the contour of 200-300 neuronal bodies (perikarya) was traced directly on a video screen with a mouse in real time. The cross-sectional area of VG perikarya was 67.29 micrometers2 at stage 34 (E8), 128.46 micrometers2 at stage 39 (E13) and 275.85 micrometers2 at stage 44 (E18). The cross-sectional area of SAG perikarya was 62.44 micrometers2 at stage 34 (E8), 102.05 micrometers2 at stage 39 (E13) and 165.02 micrometers2 at stage 44 (E18). A significant cross-sectional area increase of the VG perikarya between stage 39 (E13) and stage 44 (E18) was determined. We randomly measured the cross-sectional area of myelin and axoplasm of hatchling afferent nerves, and found a correspondence between axoplasmic and myelin cross-sectional area in the utricular, saccular and semicircular canal nerve branches of the nerve. The results suggest that the period between stage 34 (E8) and 39 (E13) is a critical period for afferent neuronal development. Physiological and behavioral vestibular properties of developing and maturing hatchlings may change accordingly. The results compliment previous work by other investigators and provide valuable anatomical measures useful to correlate physiological data obtained from stimulation of the whole nerve or its parts.

  14. Circadian variation in gastric vagal afferent mechanosensitivity.

    PubMed

    Kentish, Stephen J; Frisby, Claudine L; Kennaway, David J; Wittert, Gary A; Page, Amanda J

    2013-12-01

    Food intake is coordinated to cellular metabolism by clock gene expression with a master clock in the suprachiasmatic nucleus synchronized by light exposure. Gastric vagal afferents play a role in regulating food intake, but it is unknown whether they exhibit circadian variation in their mechanosensitivity. We aimed to determine whether gastric vagal afferents express clock genes and whether their response to mechanical stimuli oscillates throughout the light/dark cycle. Nodose ganglia were collected from 8-week-old female C57BL/6 mice every 3 h starting at lights off (1800 h) to quantify Bmal1, Per1, Per2, and Nr1d1 mRNA by qRT-PCR. Additionally in vitro single-fiber recordings of gastric vagal mechanoreceptors were taken at all time points. Per1, Per2, Bmal1, and Nr1d1 mRNA is expressed in the nodose ganglia and levels oscillated over a 24 h period. In mice fed ad libitum, gastric content was 3 times higher at 0000 h and 0300 h than 1200 h. The response of tension receptors to 3 g stretch was reduced by up to 70% at 2100 h, 0000 h, and 0300 h compared with 1200 h. Gastric mucosal receptor response to stroking with a 50 mg von Frey hair was 3 times greater at 1200 h and 1500 h than the response at 0000 h. Similar findings were obtained in mice fasted for 6 h or maintained in darkness for 3 d before study. Therefore, these changes do not result from food intake or the light/dark cycle. Thus, gastric vagal mechanoreceptors display circadian rhythm, which may act to control food intake differentially at different times of the day. PMID:24305819

  15. Monitoring of small lymphatics function under different impact on animal model by integrated optical imaging

    NASA Astrophysics Data System (ADS)

    Galanzha, Ekaterina I.; Tuchin, Valery V.; Chowdhury, Parimal; Zharov, Vladimir P.

    2004-08-01

    The digital transmission microscopy is very informative, noninvasive for vessels, simple and available method for studying and measuring lymph microvessels function in vivo. Rat mesentery can use as promising animal model of lymph microvessels in vivo. Such imaging system allowed visualizing the entire lymphangion (with input and output valves), its wall, lymphatic valves, lymph flow as well as single cells in flow; obtaining anew basic information on lymph microcirculation and quantitative data on lymphatic function including indexes of phasic contractions and valve function, the quantitative parameters of lymph-flow velocity. Rat mesentery is good model to create different types of lymphedemas in acute and chronic experiments. The obtained data revealed that significant edema started immediately after lymph node dissection in one-half of cases and was accompanied by lymphatic disturbances. The greatest degree of edema was found after 1 week. After 4 weeks, the degree of edema sometimes decreased, but functional lymphatic disturbances progressed. Nicotine had significant direct dose-dependent effect on microlymphatic function at the acute local application, but the same dose of this drug was not effect on microcirculation in chronic intoxication. Despite yielding interesting data, transmittance microscopy had some limitations when applied to microcirculation studies. The problems could be solved at the application of integrated measuring technique.

  16. Development of the lymphatic system: new questions and paradigms.

    PubMed

    Semo, Jonathan; Nicenboim, Julian; Yaniv, Karina

    2016-03-15

    The lymphatic system is a blind-ended network of vessels that plays important roles in mediating tissue fluid homeostasis, intestinal lipid absorption and the immune response. A profound understanding of the development of lymphatic vessels, as well as of the molecular cues governing their formation and morphogenesis, might prove essential for our ability to treat lymphatic-related diseases. The embryonic origins of lymphatic vessels have been debated for over a century, with a model claiming a venous origin for the lymphatic endothelium being predominant. However, recent studies have provided new insights into the origins of lymphatic vessels. Here, we review the molecular mechanisms controlling lymphatic specification and sprouting, and we discuss exciting findings that shed new light on previously uncharacterized sources of lymphatic endothelial cells.

  17. Differential permeability of lymphatic and blood vessels in determining the route of metastasis as demonstrated by indirect lymphography.

    PubMed

    Kim, U; Park, H C; Choi, K H

    1988-01-01

    Indirect mammo-lymphography with serial radiograms was made on rats bearing three established rat mammary carcinomas (SMT-2A, TMT-50, MT-W9B), with the water-soluble contrast medium, Iotasul. In the lymphogenously metastasizing SMT-2A, fine lymphatic sprouts from the tumor were seen converging into an afferent lymph vessel that was extending toward a metastatic regional lymph node, in 15-30 min. For 45 min, the dye remained localized in the primary tumor with no other vascular structures or viscera visible until it emerged in the urinary bladder, indicating that Iotasul was absorbed slowly into the systemic circulation via lymphatics and diluted beyond recognition by lymph and blood, and then reconcentrated in urine. In contrast, in the hematogenously metastasizing TMT-50, Iotasul was rapidly diffused into the blood stream, revealing the inferior caval vein within 5 min, and by 15 min the heart, aorta, common carotid arteries, kidney and ureter were all clearly revealed. In the non-metastasizing MT-W9B host, several small vascular markings around the tumor were seen by 10 min and the outline of kidneys and urinary bladder in 15 min, suggesting that the dye was also absorbed through blood capillaries but somewhat slowly. Thus, the differential vascular permeability in rat mammary tumors revealed by Iotasul has not only helped to distinguish lymphatics from blood vessels, but also to correlate it with their metastatic potential.

  18. Unmyelinated type II afferent neurons report cochlear damage

    PubMed Central

    Liu, Chang; Glowatzki, Elisabeth; Fuchs, Paul Albert

    2015-01-01

    In the mammalian cochlea, acoustic information is carried to the brain by the predominant (95%) large-diameter, myelinated type I afferents, each of which is postsynaptic to a single inner hair cell. The remaining thin, unmyelinated type II afferents extend hundreds of microns along the cochlear duct to contact many outer hair cells. Despite this extensive arbor, type II afferents are weakly activated by outer hair cell transmitter release and are insensitive to sound. Intriguingly, type II afferents remain intact in damaged regions of the cochlea. Here, we show that type II afferents are activated when outer hair cells are damaged. This response depends on both ionotropic (P2X) and metabotropic (P2Y) purinergic receptors, binding ATP released from nearby supporting cells in response to hair cell damage. Selective activation of P2Y receptors increased type II afferent excitability by the closure of KCNQ-type potassium channels, a potential mechanism for the painful hypersensitivity (that we term “noxacusis” to distinguish from hyperacusis without pain) that can accompany hearing loss. Exposure to the KCNQ channel activator retigabine suppressed the type II fiber’s response to hair cell damage. Type II afferents may be the cochlea’s nociceptors, prompting avoidance of further damage to the irreparable inner ear. PMID:26553995

  19. Lymphangiogenesis, Lymphatic Endothelial Cells and Lymphatic Metastasis in Head and Neck Cancer — A Review of Mechanisms

    PubMed Central

    Zhang, Zhuang; Helman, Joseph I; Li, Long-jiang

    2010-01-01

    Lymphatic metastasis is a continuous and complicated process. The detailed mechanisms of lymphatic metastasis are still not very clear, despite considerable research efforts in recent years. Previously, it was commonly accepted that there were no lymphatic vessels in the primary tumor. However, recent studies have demonstrated that lymphatic vessels are detectable in certain types of cancer, and more and more evidence has shown that cancer cells invade into local lymph nodes mainly via peritumoral lymphatic vessels. Moreover, activated endothelial cells may also be important, having an influence on lymphatic metastasis of cancer cells. This article, based on recent research findings, provides an in-depth discussion of the relationship between lymphangiogenesis, tumor-derived lymphatic endothelial cells and lymphatic metastasis in head and neck cancer. PMID:20690413

  20. Cerebral Lipiodol Embolism after Lymphatic Embolization for Plastic Bronchitis

    PubMed Central

    Kirschen, Matthew P.; Dori, Yoav; Itkin, Maxim; Licht, Daniel J.; Ichord, Rebecca; Vossough, Arastoo

    2016-01-01

    An adolescent with plastic bronchitis due to congenital heart disease had altered mental status after an interventional lymphatic procedure in which lipiodol contrast was used. Neuroimaging revealed cerebral lipiodol embolization due to direct shunting between lymphatic channels and pulmonary veins. Cerebral lipiodol embolization is a potential neurologic morbidity associated with interventional lymphatic procedures. PMID:27297208

  1. [Chylous reflux and chylous ascites in lymphatic dysplasia, with the lymphographic demonstration of mediastinal and retroperitoneal lymphatic cysts].

    PubMed

    Hermanutz, K D; Boldt, I; Frotscher, U

    1975-01-01

    Two patients with congenital dysplasia of the lymphatic system and with chylous ascites are described. In one 24-year old woman with this rare condition, it was possible to demonstrate for the first time numerous mediastinal lymphatic cysts during lymphangiography. Both patients showed an abnormality of the retroperitoneal lymphatics, consisting of lymphatic dilatation and cysts. In the investigation of chylous ascites, direct lymphangiography must be regarded as a valuable and necessary investigation.

  2. Firing of antagonist small-diameter muscle afferents reduces voluntary activation and torque of elbow flexors.

    PubMed

    Kennedy, David S; McNeil, Chris J; Gandevia, Simon C; Taylor, Janet L

    2013-07-15

    During muscle fatigue, firing of small-diameter muscle afferents can decrease voluntary activation of the fatigued muscle. However, these afferents may have a more widespread effect on other muscles in the exercising limb. We examined if the firing of fatigue-sensitive afferents from elbow extensor muscles in the same arm reduces torque production and voluntary activation of elbow flexors. In nine subjects we examined voluntary activation of elbow flexors by measuring changes in superimposed twitches evoked by transcranial magnetic stimulation of the motor cortex during brief (2-3 s) maximal voluntary contractions (MVC). Inflation of a blood pressure cuff following a 2-min sustained MVC blocked blood flow to the fatigued muscle and maintained firing of small-diameter afferents. After a fatiguing elbow flexion contraction, maximal flexion torque was lower (26.0 ± 4.4% versus 67.9 ± 5.2% of initial maximal torque; means ± s.d.; P < 0.001) and superimposed twitches were larger (4.1 ± 1.1% versus 1.8 ± 0.2% ongoing MVC, P = 0.01) with than without ischaemia. After a fatiguing elbow extensor contraction, maximal flexion torque was also reduced (82.2 ± 4.9% versus 91.4 ± 2.3% of initial maximal torque; P = 0.007), superimposed twitches were larger (2.7 ± 0.7% versus 1.3 ± 0.2% ongoing MVC; P = 0.02) and voluntary activation lower (81.6 ± 8.2% versus 95.5 ± 6.9%; P = 0.04) with than without ischaemia. After a fatiguing contraction, voluntary drive to the fatigued muscles is reduced with continued input from small-diameter muscle afferents. Furthermore, fatigue of the elbow extensor muscles decreases voluntary drive to unfatigued elbow flexors of the same arm. Therefore, firing of small-diameter muscle afferents from one muscle can affect voluntary activation and hence torque generation of another muscle in the same limb. PMID:23652589

  3. Ex-Vivo Lymphatic Perfusion System for Independently Controlling Pressure Gradient and Transmural Pressure in Isolated Vessels

    PubMed Central

    Kornuta, Jeffrey A.; Dixon, J. Brandon

    2015-01-01

    In addition to external forces, collecting lymphatic vessels intrinsically contract to transport lymph from the extremities to the venous circulation. As a result, the lymphatic endothelium is routinely exposed to a wide range of dynamic mechanical forces, primarily fluid shear stress and circumferential stress, which have both been shown to affect lymphatic pumping activity. Although various ex-vivo perfusion systems exist to study this innate pumping activity in response to mechanical stimuli, none are capable of independently controlling the two primary mechanical forces affecting lymphatic contractility: transaxial pressure gradient, ΔP, which governs fluid shear stress; and average transmural pressure, Pavg, which governs circumferential stress. Hence, the authors describe a novel ex-vivo lymphatic perfusion system (ELPS) capable of independently controlling these two outputs using a linear, explicit model predictive control (MPC) algorithm. The ELPS is capable of reproducing arbitrary waveforms within the frequency range observed in the lymphatics in vivo, including a time-varying ΔP with a constant Pavg, time-varying ΔP and Pavg, and a constant ΔP with a time-varying Pavg. In addition, due to its implementation of syringes to actuate the working fluid, a post-hoc method of estimating both the flow rate through the vessel and fluid wall shear stress over multiple, long (5 sec) time windows is also described. PMID:24809724

  4. Tumor cell entry into the lymph node is controlled by CCL1 chemokine expressed by lymph node lymphatic sinuses

    PubMed Central

    Das, Suvendu; Sarrou, Eliana; Podgrabinska, Simona; Cassella, Melanie; Mungamuri, Sathish Kumar; Feirt, Nikki; Gordon, Ronald; Nagi, Chandandeep S.; Wang, Yarong; Entenberg, David; Condeelis, John

    2013-01-01

    Lymphatic vessels are thought to contribute to metastasis primarily by serving as a transportation system. It is widely believed that tumor cells enter lymph nodes passively by the flow of lymph. We demonstrate that lymph node lymphatic sinuses control tumor cell entry into the lymph node, which requires active tumor cell migration. In human and mouse tissues, CCL1 protein is detected in lymph node lymphatic sinuses but not in the peripheral lymphatics. CCR8, the receptor for CCL1, is strongly expressed by human malignant melanoma. Tumor cell migration to lymphatic endothelial cells (LECs) in vitro is inhibited by blocking CCR8 or CCL1, and recombinant CCL1 promotes migration of CCR8+ tumor cells. The proinflammatory mediators TNF, IL-1β, and LPS increase CCL1 production by LECs and tumor cell migration to LECs. In a mouse model, blocking CCR8 with the soluble antagonist or knockdown with shRNA significantly decreased lymph node metastasis. Notably, inhibition of CCR8 led to the arrest of tumor cells in the collecting lymphatic vessels at the junction with the lymph node subcapsular sinus. These data identify a novel function for CCL1–CCR8 in metastasis and lymph node LECs as a critical checkpoint for the entry of metastases into the lymph nodes. PMID:23878309

  5. The embryonic origins of lymphatic vessels: an historical review.

    PubMed

    Ribatti, Domenico; Crivellato, Enrico

    2010-06-01

    Work on the lymphatic system began in the 17th century, and by the beginning of the 19th century the anatomy of most of the lymphatic system had been described. One of the most important questions in this field has been the determination of the embryological origin of the lymphatic endothelium. Two theories were proposed. The first suggested that lymphatic endothelium derived by sprouting from venous endothelium, the so-called centrifugal theory. The second, the so-called centripetal theory, suggested that lymphatic endothelium differentiates in situ from primitive mesenchyme, and secondarily acquires connection with the vascular system. More recent evidence has provided support for both hypotheses.

  6. Lymphatic Leak Complicating Central Venous Catheter Insertion

    SciTech Connect

    Barnacle, Alex M. Kleidon, Tricia M.

    2005-12-15

    Many of the risks associated with central venous access are well recognized. We report a case of inadvertent lymphatic disruption during the insertion of a tunneled central venous catheter in a patient with raised left and right atrial pressures and severe pulmonary hypertension, which led to significant hemodynamic instability. To our knowledge, this rare complication is previously unreported.

  7. Immunopathogenesis of lymphatic filarial disease1

    PubMed Central

    Babu, Subash; Nutman, Thomas B.

    2012-01-01

    Although two-thirds of the 120 million people infected with lymph-dwelling filarial parasites have subclinical infections, ~ 40 million have lymphedema and/or other pathologic manifestations including hydroceles (and other forms of urogenital disease), episodic adenolymphangitis, tropical pulmonary eosinophilia, lymphedema, and (in its most severe form) elephantiasis. Adult filarial worms reside in the lymphatics and lymph nodes and induce changes that result in dilatation of lymphatics and thickening of the lymphatic vessel walls. Progressive lymphatic damage and pathology results from the summation of the effect of tissue alterations induced by both living and nonliving adult parasites, the host inflammatory response to the parasites and their secreted antigens, the host inflammatory response to the endosymbiont Wolbachia, and those seen as a consequence of secondary bacterial or fungal infections. Inflammatory damage induced by filarial parasites appears to be multifactorial, with endogenous parasite products, Wolbachia, and host immunity all playing important roles. This review will initially examine the prototypical immune responses engendered by the parasite and delineate the regulatory mechanisms elicited to prevent immune-mediated pathology. This will be followed by a discussion of the proposed mechanisms underlying pathogenesis, with the central theme being that pathogenesis is a two-step process - the first initiated by the parasite and host innate immune system and the second propagated mainly by the host’s adaptive immune system and by other factors (including secondary infections). PMID:23053393

  8. The Role of the Mesentery in Crohn's Disease: The Contributions of Nerves, Vessels, Lymphatics, and Fat to the Pathogenesis and Disease Course.

    PubMed

    Li, Yi; Zhu, Weiming; Zuo, Lugen; Shen, Bo

    2016-06-01

    Crohn's disease (CD) is a complex gastrointestinal disorder involving multiple levels of cross talk between the immunological, neural, vascular, and endocrine systems. The current dominant theory in CD is based on the unidirectional axis of dysbiosis-innate immunity-adaptive immunity-mesentery-body system. Emerging clinical evidence strongly suggests that the axis be bidirectional. The morphologic and/or functional abnormalities in the mesenteric structures likely contribute to the disease progression of CD, to a less extent the disease initiation. In addition to adipocytes, mesentery contains nerves, blood vessels, lymphatics, stromal cells, and fibroblasts. By the secretion of adipokines that have endocrine functions, the mesenteric fat tissue exerts its activity in immunomodulation mainly through response to afferent signals, neuropeptides, and functional cytokines. Mesenteric nerves are involved in the pathogenesis and prognosis of CD mainly through neuropeptides. In addition to angiogenesis observed in CD, lymphatic obstruction, remodeling, and impaired contraction maybe a cause and consequence of CD. Lymphangiogenesis and angiogenesis play a concomitant role in the progress of chronic intestinal inflammation. Finally, the interaction between neuropeptides, adipokines, and vascular and lymphatic endothelia leads to adipose tissue remodeling, which makes the mesentery an active participator, not a bystander, in the disease initiation and precipitation CD. The identification of the role of mesentery, including the structure and function of mesenteric nerves, vessels, lymphatics, and fat, in the intestinal inflammation in CD has important implications in understanding its pathogenesis and clinical management. PMID:27167572

  9. Aging-related anatomical and biochemical changes in lymphatic collectors impair lymph transport, fluid homeostasis, and pathogen clearance

    PubMed Central

    Zolla, Valerio; Nizamutdinova, Irina Tsoy; Scharf, Brian; Clement, Cristina C; Maejima, Daisuke; Akl, Tony; Nagai, Takashi; Luciani, Paola; Leroux, Jean-Christophe; Halin, Cornelia; Stukes, Sabriya; Tiwari, Sangeeta; Casadevall, Arturo; Jacobs, William R; Entenberg, David; Zawieja, David C; Condeelis, John; Fooksman, David R; Gashev, Anatoliy A; Santambrogio, Laura

    2015-01-01

    The role of lymphatic vessels is to transport fluid, soluble molecules, and immune cells to the draining lymph nodes. Here, we analyze how the aging process affects the functionality of the lymphatic collectors and the dynamics of lymph flow. Ultrastructural, biochemical, and proteomic analysis indicates a loss of matrix proteins, and smooth muscle cells in aged collectors resulting in a decrease in contraction frequency, systolic lymph flow velocity, and pumping activity, as measured in vivo in lymphatic collectors. Functionally, this impairment also translated into a reduced ability for in vivo bacterial transport as determined by time-lapse microscopy. Ultrastructural and proteomic analysis also indicates a decrease in the thickness of the endothelial cell glycocalyx and loss of gap junction proteins in aged lymph collectors. Redox proteomic analysis mapped an aging-related increase in the glycation and carboxylation of lymphatic’s endothelial cell and matrix proteins. Functionally, these modifications translate into apparent hyperpermeability of the lymphatics with pathogen escaping from the collectors into the surrounding tissue and a decreased ability to control tissue fluid homeostasis. Altogether, our data provide a mechanistic analysis of how the anatomical and biochemical changes, occurring in aged lymphatic vessels, compromise lymph flow, tissue fluid homeostasis, and pathogen transport. PMID:25982749

  10. The renal nerves in chronic heart failure: efferent and afferent mechanisms

    PubMed Central

    Schiller, Alicia M.; Pellegrino, Peter R.; Zucker, Irving H.

    2015-01-01

    The function of the renal nerves has been an area of scientific and medical interest for many years. The recent advent of a minimally invasive catheter-based method of renal denervation has renewed excitement in understanding the afferent and efferent actions of the renal nerves in multiple diseases. While hypertension has been the focus of much this work, less attention has been given to the role of the renal nerves in the development of chronic heart failure (CHF). Recent studies from our laboratory and those of others implicate an essential role for the renal nerves in the development and progression of CHF. Using a rabbit tachycardia model of CHF and surgical unilateral renal denervation, we provide evidence for both renal efferent and afferent mechanisms in the pathogenesis of CHF. Renal denervation prevented the decrease in renal blood flow observed in CHF while also preventing increases in Angiotensin-II receptor protein in the microvasculature of the renal cortex. Renal denervation in CHF also reduced physiological markers of autonomic dysfunction including an improvement in arterial baroreflex function, heart rate variability, and decreased resting cardiac sympathetic tone. Taken together, the renal sympathetic nerves are necessary in the pathogenesis of CHF via both efferent and afferent mechanisms. Additional investigation is warranted to fully understand the role of these nerves and their role as a therapeutic target in CHF. PMID:26300788

  11. Baroreceptor afferents modulate brain excitation and influence susceptibility to toxic effects of hyperbaric oxygen.

    PubMed

    Demchenko, Ivan T; Gasier, Heath G; Zhilyaev, Sergei Yu; Moskvin, Alexander N; Krivchenko, Alexander I; Piantadosi, Claude A; Allen, Barry W

    2014-09-01

    Unexplained adjustments in baroreflex sensitivity occur in conjunction with exposures to potentially toxic levels of hyperbaric oxygen. To investigate this, we monitored central nervous system, autonomic and cardiovascular responses in conscious and anesthetized rats exposed to hyperbaric oxygen at 5 and 6 atmospheres absolute, respectively. We observed two contrasting phases associated with time-dependent alterations in the functional state of the arterial baroreflex. The first phase, which conferred protection against potentially neurotoxic doses of oxygen, was concurrent with an increase in baroreflex sensitivity and included decreases in cerebral blood flow, heart rate, cardiac output, and sympathetic drive. The second phase was characterized by baroreflex impairment, cerebral hyperemia, spiking on the electroencephalogram, increased sympathetic drive, parasympatholysis, and pulmonary injury. Complete arterial baroreceptor deafferentation abolished the initial protective response, whereas electrical stimulation of intact arterial baroreceptor afferents prolonged it. We concluded that increased afferent traffic attributable to arterial baroreflex activation delays the development of excessive central excitation and seizures. Baroreflex inactivation or impairment removes this protection, and seizures may follow. Finally, electrical stimulation of intact baroreceptor afferents extends the normal delay in seizure development. These findings reveal that the autonomic nervous system is a powerful determinant of susceptibility to sympathetic hyperactivation and seizures in hyperbaric oxygen and the ensuing neurogenic pulmonary injury.

  12. Effector T cell egress via afferent lymph modulates local tissue inflammation1

    PubMed Central

    Gómez, Daniela; Diehl, Malissa C.; Crosby, Erika J.; Weinkopff, Tiffany; Debes, Gudrun F.

    2015-01-01

    Memory/effector T cells recirculate through extralymphoid tissues by entering from blood and egressing via afferent lymph. While T cell entry into effector sites is key to inflammation, the relevance of T cell egress to this process is unknown. Here we found that antigen recognition at the effector site reduced the tissue egress of pro-inflammatory Th1 cells in a mouse model of delayed hypersensitivity. Transgenic expression of ‘tissue exit receptor’ CCR7 enhanced lymphatic egress of antigen-sequestered Th1 cells from the inflamed site and ameliorated inflammation. In contrast, lack of CCR7 on Th1 cells diminished their tissue egress while enhancing inflammation. Lymph-borne Th1 and Th17 cells draining the inflamed skin of sheep migrated toward the CCR7 ligand CCL21, suggesting the CCR7-CCL21 axis as a physiological target in regulating inflammation. In conclusion, exit receptors can be targeted to modulate T cell dwell time and inflammation at effector sites, revealing T cell tissue egress as a novel control point of inflammation. PMID:26355150

  13. Differential central projections of vestibular afferents in pigeons

    NASA Technical Reports Server (NTRS)

    Dickman, J. D.; Fang, Q.

    1996-01-01

    The question of whether a differential distribution of vestibular afferent information to central nuclear neurons is present in pigeons was studied using neural tracer compounds. Discrete tracing of afferent fibers innervating the individual semicircular canal and otolith organs was produced by sectioning individual branches of the vestibular nerve that innervate the different receptor organs and applying crystals of horseradish peroxidase, or a horseradish peroxidase/cholera toxin mixture, or a biocytin compound for neuronal uptake and transport. Afferent fibers and their terminal distributions within the brainstem and cerebellum were visualized subsequently. Discrete areas in the pigeon central nervous system that receive primary vestibular input include the superior, dorsal lateral, ventral lateral, medial, descending, and tangential vestibular nuclei; the A and B groups; the intermediate, medial, and lateral cerebellar nuclei; and the nodulus, the uvula, and the paraflocculus. Generally, the vertical canal afferents projected heavily to medial regions in the superior and descending vestibular nuclei as well as the A group. Vertical canal projections to the medial and lateral vestibular nuclei were observed but were less prominent. Horizontal canal projections to the superior and descending vestibular nuclei were much more centrally located than those of the vertical canals. A more substantial projection to the medial and lateral vestibular nuclei was seen with horizontal canal afferents compared to vertical canal fibers. Afferents innervating the utricle and saccule terminated generally in the lateral regions of all vestibular nuclei in areas that were separate from the projections of the semicircular canals. In addition, utricular fibers projected to regions in the vestibular nuclei that overlapped with the horizontal semicircular canal terminal fields, whereas saccular afferents projected to regions that received vertical canal fiber terminations. Lagenar

  14. Pkd1 regulates lymphatic vascular morphogenesis during development.

    PubMed

    Coxam, Baptiste; Sabine, Amélie; Bower, Neil I; Smith, Kelly A; Pichol-Thievend, Cathy; Skoczylas, Renae; Astin, Jonathan W; Frampton, Emmanuelle; Jaquet, Muriel; Crosier, Philip S; Parton, Robert G; Harvey, Natasha L; Petrova, Tatiana V; Schulte-Merker, Stefan; Francois, Mathias; Hogan, Benjamin M

    2014-05-01

    Lymphatic vessels arise during development through sprouting of precursor cells from veins, which is regulated by known signaling and transcriptional mechanisms. The ongoing elaboration of vessels to form a network is less well understood. This involves cell polarization, coordinated migration, adhesion, mixing, regression, and shape rearrangements. We identified a zebrafish mutant, lymphatic and cardiac defects 1 (lyc1), with reduced lymphatic vessel development. A mutation in polycystic kidney disease 1a was responsible for the phenotype. PKD1 is the most frequently mutated gene in autosomal dominant polycystic kidney disease (ADPKD). Initial lymphatic precursor sprouting is normal in lyc1 mutants, but ongoing migration fails. Loss of Pkd1 in mice has no effect on precursor sprouting but leads to failed morphogenesis of the subcutaneous lymphatic network. Individual lymphatic endothelial cells display defective polarity, elongation, and adherens junctions. This work identifies a highly selective and unexpected role for Pkd1 in lymphatic vessel morphogenesis during development.

  15. Afferent innervation of the utricular macula in pigeons

    NASA Technical Reports Server (NTRS)

    Si, Xiaohong; Zakir, Mridha Md; Dickman, J. David

    2003-01-01

    Biotinylated dextran amine (BDA) was used to retrogradely label afferents innervating the utricular macula in adult pigeons. The pigeon utriclar macula consists of a large rectangular-shaped neuroepithelium with a dorsally curved anterior edge and an extended medioposterior tail. The macula could be demarcated into several regions based on cytoarchitectural differences. The striola occupied 30% of the macula and contained a large density of type I hair cells with fewer type II hair cells. Medial and lateral extrastriola zones were located outside the striola and contained only type II hair cells. A six- to eight-cell-wide band of type II hair cells existed near the center of the striola. The reversal line marked by the morphological polarization of hair cells coursed throughout the epithelium, near the peripheral margin, and through the center of the type II band. Calyx afferents innervated type I hair cells with calyceal terminals that contained between 2 and 15 receptor cells. Calyx afferents were located only in the striola region, exclusive of the type II band, had small total fiber innervation areas and low innervation densities. Dimorph afferents innervated both type I and type II hair cells with calyceal and bouton terminals and were primarily located in the striola region. Dimorph afferents had smaller calyceal terminals with few type I hair cells, extended fiber branches with bouton terminals and larger innervation areas. Bouton afferents innervated only type II hair cells in the extrastriola and type II band regions. Bouton afferents innervating the type II band had smaller terminal fields with fewer bouton terminals and smaller innervation areas than fibers located in the extrastriolar zones. Bouton afferents had the most bouton terminals on the longest fibers, the largest innervation areas with the highest innervation densities of all afferents. Among all afferents, smaller terminal innervation fields were observed in the striola and large fields were

  16. Mast cells drive mesenteric afferent signalling during acute intestinal ischaemia

    PubMed Central

    Jiang, Wen; Kirkup, Anthony J; Grundy, David

    2011-01-01

    Abstract Acute intestinal ischaemia stimulates visceral afferent nerves but the mechanisms responsible for this excitation are not fully understood. Mast cells may participate in this process as they are known to signal to mesenteric afferents during intestinal anaphylaxis and contribute to early inflammation and neuronal damage in response to cerebral ischaemia. We therefore hypothesised that mast cells are early responders to acute intestinal ischaemia and their activation initiates rapid signalling to the CNS via the excitation of mesenteric afferents. Primary afferent firing was recorded from a mesenteric nerve bundle supplying a segment of jejunum in anaesthetized adult rats. Acute focal ischaemia was produced by clamping the mesenteric vessels for 8 min, and reperfusion followed removal of the vessel clip. Two episodes of ischaemia–reperfusion (I–R) separated by a 30 min interval were performed. Drugs or their vehicles were administered 10 min before the 2nd I–R episode. Ischaemia caused a reproducible, intense and biphasic afferent firing that was temporally dissociated from the concomitantly triggered complex pattern of intestinal motor activity. The L-type calcium channel blocker, nifedipine, significantly attenuated this afferent firing by a mechanism independent of its action on intestinal tone. Ischaemia-induced afferent firing was also abrogated by the mast cell stabilizer, doxantrazole, and the H1 histamine receptor antagonist, pyrilamine. In contrast, the nicotinic receptor antagonist, hexamethonium, and the N-type calcium channel toxin, ω-conotoxin GVIA, each reduced the ischaemia-evoked motor inhibition but not the concurrent afferent discharge. Similarly, the cyclooxygenase inhibitor, naproxen, had no effect on the ischaemic afferent response but reduced the intestinal tone shortly from the onset of ischaemia to the early period of reperfusion. These data support a critical role for mast cell-derived histamine in the direct chemoexcitation

  17. The mesenteric lymph duct cannulated rat model: application to the assessment of intestinal lymphatic drug transport.

    PubMed

    Trevaskis, Natalie L; Hu, Luojuan; Caliph, Suzanne M; Han, Sifei; Porter, Christopher J H

    2015-03-06

    The intestinal lymphatic system plays key roles in fluid transport, lipid absorption and immune function. Lymph flows directly from the small intestine via a series of lymphatic vessels and nodes that converge at the superior mesenteric lymph duct. Cannulation of the mesenteric lymph duct thus enables the collection of mesenteric lymph flowing from the intestine. Mesenteric lymph consists of a cellular fraction of immune cells (99% lymphocytes), aqueous fraction (fluid, peptides and proteins such as cytokines and gut hormones) and lipoprotein fraction (lipids, lipophilic molecules and apo-proteins). The mesenteric lymph duct cannulation model can therefore be used to measure the concentration and rate of transport of a range of factors from the intestine via the lymphatic system. Changes to these factors in response to different challenges (e.g., diets, antigens, drugs) and in disease (e.g., inflammatory bowel disease, HIV, diabetes) can also be determined. An area of expanding interest is the role of lymphatic transport in the absorption of orally administered lipophilic drugs and prodrugs that associate with intestinal lipid absorption pathways. Here we describe, in detail, a mesenteric lymph duct cannulated rat model which enables evaluation of the rate and extent of lipid and drug transport via the lymphatic system for several hours following intestinal delivery. The method is easily adaptable to the measurement of other parameters in lymph. We provide detailed descriptions of the difficulties that may be encountered when establishing this complex surgical method, as well as representative data from failed and successful experiments to provide instruction on how to confirm experimental success and interpret the data obtained.

  18. Mesenchymal status of lymphatic endothelial cell: enlightening treatment of lymphatic malformation.

    PubMed

    Cai, Xu; Zhang, Wei; Chen, Gang; Li, Rui-Fang; Sun, Yan-Fang; Zhao, Yi-Fang

    2015-01-01

    In contrast to blood capillaries, lymphatic capillaries in peripheral tissues are composed of a single-cell layer of lymphatic endothelial cells (LECs) without a covering of mural cells. However, in lymphatic malformations, the enlarged lymphatic vessels were covered with mural cells. This study aimed to understand the molecular mechanism of differences between human dermal lymphatic endothelial cells (HDLECs) and human umbilical vein endothelial cells (HUVECs) and to determine the changes of LECs in the pathological condition of lymphatic malformation. Results showed that HDLECs exhibited lower expression of endothelial proteins, including VE-cadherin and CD31, than HUVECs; HDLECs also showed higher expression of mesenchymal proteins, including α-SMA, SM22α, calponin, and epithelial mesenchymal transition-related transcription factor Slug, than HUVECs. Likewise, HDLECs displayed higher permeability and weaker recruitment of SMCs than HUVECs; HDLECs also exhibited low PDGF-BB expression. TGF-β2 treatment and FGF2 depletion enhanced mesenchymal marker expression with increased permeability and reduced SMC recruitment. By contrast, Slug depletion in HDLECs enhanced VE-cadherin expression, inhibited α-SMA expression, decreased permeability, and enhanced PDGF-BB expression. These results suggested that HDLECs were in a mesenchymal status, which contributed to their functions and might determine their identities. Our data also revealed that miR143/145 was implicated in the mesenchymal status of HDLECs. In lymphatic malformations (LMs) treated with OK-432 sclerotherapy, immunohistochemistry results showed that Prox1 expression was reduced and mural cell investment was increased; these results indicated that LECs lost their mesenchymal status after OK-432 treatment was administered. The decreased mesenchymal status of LECs in LMs may induce dilated vessel constriction, which could be the mechanism of OK-432 sclerotherapy. PMID:26550134

  19. Dopaminergic Modulation of the Voltage-Gated Sodium Current in the Cochlear Afferent Neurons of the Rat

    PubMed Central

    Valdés-Baizabal, Catalina; Soto, Enrique; Vega, Rosario

    2015-01-01

    The cochlear inner hair cells synapse onto type I afferent terminal dendrites, constituting the main afferent pathway for auditory information flow. This pathway receives central control input from the lateral olivocochlear efferent neurons that release various neurotransmitters, among which dopamine (DA) plays a salient role. DA receptors activation exert a protective role in the over activation of the afferent glutamatergic synapses, which occurs when an animal is exposed to intense sound stimuli or during hypoxic events. However, the mechanism of action of DA at the cellular level is still not completely understood. In this work, we studied the actions of DA and its receptor agonists and antagonists on the voltage-gated sodium current (INa) in isolated cochlear afferent neurons of the rat to define the mechanisms of dopaminergic control of the afferent input in the cochlear pathway. Experiments were performed using the voltage and current clamp techniques in the whole-cell configuration in primary cultures of cochlear spiral ganglion neurons (SGNs). Recordings of the INa showed that DA receptor activation induced a significant inhibition of the peak current amplitude, leading to a significant decrease in cell excitability. Inhibition of the INa was produced by a phosphorylation of the sodium channels as shown by the use of phosphatase inhibitor that produced an inhibition analogous to that caused by DA receptor activation. Use of specific agonists and antagonists showed that inhibitory action of DA was mediated both by activation of D1- and D2-like DA receptors. The action of the D1- and D2-like receptors was shown to be mediated by a Gαs/AC/cAMP/PKA and Gαq/PLC/PKC pathways respectively. These results showed that DA receptor activation constitutes a significant modulatory input to SGNs, effectively modulating their excitability and information flow in the auditory pathway. PMID:25768433

  20. Dopaminergic modulation of the voltage-gated sodium current in the cochlear afferent neurons of the rat.

    PubMed

    Valdés-Baizabal, Catalina; Soto, Enrique; Vega, Rosario

    2015-01-01

    The cochlear inner hair cells synapse onto type I afferent terminal dendrites, constituting the main afferent pathway for auditory information flow. This pathway receives central control input from the lateral olivocochlear efferent neurons that release various neurotransmitters, among which dopamine (DA) plays a salient role. DA receptors activation exert a protective role in the over activation of the afferent glutamatergic synapses, which occurs when an animal is exposed to intense sound stimuli or during hypoxic events. However, the mechanism of action of DA at the cellular level is still not completely understood. In this work, we studied the actions of DA and its receptor agonists and antagonists on the voltage-gated sodium current (INa) in isolated cochlear afferent neurons of the rat to define the mechanisms of dopaminergic control of the afferent input in the cochlear pathway. Experiments were performed using the voltage and current clamp techniques in the whole-cell configuration in primary cultures of cochlear spiral ganglion neurons (SGNs). Recordings of the INa showed that DA receptor activation induced a significant inhibition of the peak current amplitude, leading to a significant decrease in cell excitability. Inhibition of the INa was produced by a phosphorylation of the sodium channels as shown by the use of phosphatase inhibitor that produced an inhibition analogous to that caused by DA receptor activation. Use of specific agonists and antagonists showed that inhibitory action of DA was mediated both by activation of D1- and D2-like DA receptors. The action of the D1- and D2-like receptors was shown to be mediated by a Gαs/AC/cAMP/PKA and Gαq/PLC/PKC pathways respectively. These results showed that DA receptor activation constitutes a significant modulatory input to SGNs, effectively modulating their excitability and information flow in the auditory pathway. PMID:25768433

  1. Microcirculation-on-a-Chip: A Microfluidic Platform for Assaying Blood- and Lymphatic-Vessel Permeability

    PubMed Central

    Sato, Miwa; Sasaki, Naoki; Ato, Manabu; Hirakawa, Satoshi; Sato, Kiichi; Sato, Kae

    2015-01-01

    We developed a microfluidic model of microcirculation containing both blood and lymphatic vessels for examining vascular permeability. The designed microfluidic device harbors upper and lower channels that are partly aligned and are separated by a porous membrane, and on this membrane, blood vascular endothelial cells (BECs) and lymphatic endothelial cells (LECs) were cocultured back-to-back. At cell-cell junctions of both BECs and LECs, claudin-5 and VE-cadherin were detected. The permeability coefficient measured here was lower than the value reported for isolated mammalian venules. Moreover, our results showed that the flow culture established in the device promoted the formation of endothelial cell-cell junctions, and that treatment with histamine, an inflammation-promoting substance, induced changes in the localization of tight and adherens junction-associated proteins and an increase in vascular permeability in the microdevice. These findings indicated that both BECs and LECs appeared to retain their functions in the microfluidic coculture platform. Using this microcirculation device, the vascular damage induced by habu snake venom was successfully assayed, and the assay time was reduced from 24 h to 30 min. This is the first report of a microcirculation model in which BECs and LECs were cocultured. Because the micromodel includes lymphatic vessels in addition to blood vessels, the model can be used to evaluate both vascular permeability and lymphatic return rate. PMID:26332321

  2. Demonstrating the lymphatic system in rats with microinjection.

    PubMed

    Suami, Hiroo; Chang, David W; Matsumoto, Kumiko; Kimata, Yoshihiro

    2011-09-01

    The lymphatic system plays an important role in human health and disease. In addition to a role in the immune response, the lymphatics can serve as a pathway for cancer metastasis. Visualizing the lymphatic system has been a difficult part of anatomic dissection studies. Anatomists have attempted to map the lymphatic system using various methods and materials; vivisection of dogs, injection of mercury into the skin and lymphatic vessel in cadavers, and injection of dye indirectly into the skin of dead and living specimens. In this study, we introduce a method of using a mixture of acrylic blue dye and hydrogen peroxide to visualize the lymphatic system in rats. The lymphatic vessels were cannulated with micropipettes, and radio-opaque orange lead oxide was selectively injected. The lymphatic system became visible from the dorsal side of the hand and foot, and distal region of the tail to their termination at the left and right subclavicular veins via lymph nodes. Cisterna chyli in the abdominal cavity and thoracic duct ran along with the aorta. The advantage of this technique is that lymph nodes as well as lymphatic channels could be recorded not only photographically but also radiographically. This microinjection technique is useful for demonstrating the lymphatic system in rats and may provide further information that will help in cancer metastasis research.

  3. The lymphatic vasculature: development and role in shaping immunity.

    PubMed

    Betterman, Kelly L; Harvey, Natasha L

    2016-05-01

    The lymphatic vasculature is an integral component of the immune system. Lymphatic vessels are a key highway via which immune cells are trafficked, serving not simply as a passive route of transport, but to actively shape and coordinate immune responses. Reciprocally, immune cells provide signals that impact the growth, development, and activity of the lymphatic vasculature. In addition to immune cell trafficking, lymphatic vessels are crucial for fluid homeostasis and lipid absorption. The field of lymphatic vascular research is rapidly expanding, fuelled by rapidly advancing technology that has enabled the manipulation and imaging of lymphatic vessels, together with an increasing recognition of the involvement of lymphatic vessels in a myriad of human pathologies. In this review we provide an overview of the genetic pathways and cellular processes important for development and maturation of the lymphatic vasculature, discuss recent work revealing important roles for the lymphatic vasculature in directing immune cell traffic and coordinating immune responses and highlight the involvement of lymphatic vessels in a range of pathological settings.

  4. Comparison of approaches for microscopic imaging of skin lymphatic vessels.

    PubMed

    Wu, Xiufeng; Yu, Zheyuan; Liu, Ningfei

    2012-01-01

    Assessment of skin lymphatic vessels is of great significance in understanding their roles in many pathological conditions. Our aim was to identify the optimal approach for investigation of cutaneous lymphatic system. We performed comparative studies on skin lymphatic vessels using immunohistochemistry of tissue sections, computer graphic reconstruction method together with immunohistochemically stained serial sections and whole mount fluorescence in human lower limb. Lymphatic vessels were identified with podoplanin antibody. The relative merits and drawbacks of each method in evaluation of structure, spatial organization, and distribution of cutaneous lymphatic vessels were described. Immunohistology of tissue sections enabled the investigation of the structure and distribution of the whole cutaneous lymphatic system in two-dimensional slices, whereas three-dimensional morphology of only the most superficial lymph capillary network immediately under the epidermis could be evaluated with the whole mount technique. Meanwhile, only little segmentation of skin lymphatic vessel from five immunohistochemically stained serial sections was reconstructed and evaluated due to expense and special skills required using computer graphic three-dimensional reconstruction. Furthermore, a great number of artifacts and special skills required in its processes leaded to less accurate structure of skin lymphatic vessels. Our findings demonstrated that the use of either of the proposed techniques alone could not allow a comprehensive analysis of the skin lymphatic system due to their relative drawbacks. Combination of immunohistology of tissue sections and three-dimensional whole-mount preparations appears to be the best candidate for comprehensive evaluation of skin lymphatic system.

  5. The lymphatic vasculature: development and role in shaping immunity.

    PubMed

    Betterman, Kelly L; Harvey, Natasha L

    2016-05-01

    The lymphatic vasculature is an integral component of the immune system. Lymphatic vessels are a key highway via which immune cells are trafficked, serving not simply as a passive route of transport, but to actively shape and coordinate immune responses. Reciprocally, immune cells provide signals that impact the growth, development, and activity of the lymphatic vasculature. In addition to immune cell trafficking, lymphatic vessels are crucial for fluid homeostasis and lipid absorption. The field of lymphatic vascular research is rapidly expanding, fuelled by rapidly advancing technology that has enabled the manipulation and imaging of lymphatic vessels, together with an increasing recognition of the involvement of lymphatic vessels in a myriad of human pathologies. In this review we provide an overview of the genetic pathways and cellular processes important for development and maturation of the lymphatic vasculature, discuss recent work revealing important roles for the lymphatic vasculature in directing immune cell traffic and coordinating immune responses and highlight the involvement of lymphatic vessels in a range of pathological settings. PMID:27088921

  6. An overview of lymphatic vessels and their emerging role in cardiovascular disease.

    PubMed

    Jones, Dennis; Min, Wang

    2011-07-01

    Over the past decade, molecular details of lymphatic vessels (lymphatics) have been rapidly acquired due to the identification of lymphatic endothelial-specific markers. Separate from the cardiovascular system, the lymphatic system is also an elaborate network of vessels that are important in normal physiology. Lymphatic vessels have the unique task to regulate fluid homeostasis, assist in immune surveillance, and transport dietary lipids. However, dysfunctional lymphatic vessels can cause pathology, while normal lymphatics can exacerbate pathology. This review summarizes the development and growth of lymphatic vessels in addition to highlighting their critical roles in physiology and pathology. Also, we discuss recent work that suggests a connection between lymphatic dysfunction and cardiovascular disease.

  7. TRPA1 mediates amplified sympathetic responsiveness to activation of metabolically sensitive muscle afferents in rats with femoral artery occlusion

    PubMed Central

    Xing, Jihong; Lu, Jian; Li, Jianhua

    2015-01-01

    Autonomic responses to activation of mechanically and metabolically sensitive muscle afferent nerves during static contraction are augmented in rats with femoral artery occlusion. Moreover, metabolically sensitive transient receptor potential cation channel subfamily A, member 1 (TRPA1) has been reported to contribute to sympathetic nerve activity (SNA) and arterial blood pressure (BP) responses evoked by static muscle contraction. Thus, in the present study, we examined the mechanisms by which afferent nerves' TRPA1 plays a role in regulating amplified sympathetic responsiveness due to a restriction of blood flow directed to the hindlimb muscles. Our data show that 24–72 h of femoral artery occlusion (1) upregulates the protein levels of TRPA1 in dorsal root ganglion (DRG) tissues; (2) selectively increases expression of TRPA1 in DRG neurons supplying metabolically sensitive afferent nerves of C-fiber (group IV); and (3) enhances renal SNA and BP responses to AITC (a TRPA1 agonist) injected into the hindlimb muscles. In addition, our data demonstrate that blocking TRPA1 attenuates SNA and BP responses during muscle contraction to a greater degree in ligated rats than those responses in control rats. In contrast, blocking TRPA1 fails to attenuate SNA and BP responses during passive tendon stretch in both groups. Overall, results of this study indicate that alternations in muscle afferent nerves' TRPA1 likely contribute to enhanced sympathetically mediated autonomic responses via the metabolic component of the muscle reflex under circumstances of chronic muscle ischemia. PMID:26441669

  8. Interactions of immune cells and lymphatic vessels.

    PubMed

    Kataru, Raghu P; Lee, Yulia G; Koh, Gou Young

    2014-01-01

    In addition to fluid and lipid absorption, immune cell trafficking has now become recognized as one of the major functions of the lymphatic system. Recently, several critical roles of the lymphatic vessels (LVs) in modulating immune reactions during both physiological and pathological conditions have been emerging. As LVs serve as conduits for immune cells, they come to closely interact with macrophages/monocytes, dendritic cells, and T and B lymphocytes. Accumulating evidences indicate that reciprocal interactions between the LVs and immune cells exist which cause considerable influence over the process of immune cell migration, LV growth, and ultimately certain immune reactions. This chapter discusses on the interactions of macrophages/monocytes and dendritic cells with peripheral LVs and on those of sinusoidal macrophages and T and B lymphocytes with lymph node LVs.

  9. Lymphatic spreading and lymphadenectomy for esophageal carcinoma

    PubMed Central

    Ji, Xiang; Cai, Jie; Chen, Yao; Chen, Long-Qi

    2016-01-01

    Esophageal carcinoma (EC) is a highly lethal malignancy with a poor prognosis. One of the most important prognostic factors in EC is lymph node status. Therefore, lymphadenectomy has been recognized as a key that influences the outcome of surgical treatment for EC. However, the lymphatic drainage system of the esophagus, including an abundant lymph-capillary network in the lamina propria and muscularis mucosa, is very complex with cervical, mediastinal and celiac node spreading. The extent of lymphadenectomy for EC has always been controversial because of the very complex pattern of lymph node spreading. In this article, published literature regarding lymphatic spreading was reviewed and the current lymphadenectomy trends for EC are discussed. PMID:26843917

  10. Aberrant mural cell recruitment to lymphatic vessels and impaired lymphatic drainage in a murine model of pulmonary fibrosis.

    PubMed

    Meinecke, Anna-Katharina; Nagy, Nadine; Lago, Gabriela D'Amico; Kirmse, Santina; Klose, Ralph; Schrödter, Katrin; Zimmermann, Annika; Helfrich, Iris; Rundqvist, Helene; Theegarten, Dirk; Anhenn, Olaf; Orian-Rousseau, Véronique; Johnson, Randall S; Alitalo, Kari; Fischer, Jens W; Fandrey, Joachim; Stockmann, Christian

    2012-06-14

    Pulmonary fibrosis is a progressive disease with unknown etiology that is characterized by extensive remodeling of the lung parenchyma, ultimately resulting in respiratory failure. Lymphatic vessels have been implicated with the development of pulmonary fibrosis, but the role of the lymphatic vasculature in the pathogenesis of pulmonary fibrosis remains enigmatic. Here we show in a murine model of pulmonary fibrosis that lymphatic vessels exhibit ectopic mural coverage and that this occurs early during the disease. The abnormal lymphatic vascular patterning in fibrotic lungs was driven by expression of platelet-derived growth factor B (PDGF-B) in lymphatic endothelial cells and signaling through platelet-derived growth factor receptor (PDGFR)-β in associated mural cells. Because of impaired lymphatic drainage, aberrant mural cell coverage fostered the accumulation of fibrogenic molecules and the attraction of fibroblasts to the perilymphatic space. Pharmacologic inhibition of the PDGF-B/PDGFR-β signaling axis disrupted the association of mural cells and lymphatic vessels, improved lymphatic drainage of the lung, and prevented the attraction of fibroblasts to the perilymphatic space. Our results implicate aberrant mural cell recruitment to lymphatic vessels in the pathogenesis of pulmonary fibrosis and that the drainage capacity of pulmonary lymphatics is a critical mediator of fibroproliferative changes.

  11. In vivo albumin labeling and lymphatic imaging.

    PubMed

    Wang, Yu; Lang, Lixin; Huang, Peng; Wang, Zhe; Jacobson, Orit; Kiesewetter, Dale O; Ali, Iqbal U; Teng, Gaojun; Niu, Gang; Chen, Xiaoyuan

    2015-01-01

    The ability to accurately and easily locate sentinel lymph nodes (LNs) with noninvasive imaging methods would assist in tumor staging and patient management. For this purpose, we developed a lymphatic imaging agent by mixing fluorine-18 aluminum fluoride-labeled NOTA (1,4,7-triazacyclononane-N,N',N''-triacetic acid)-conjugated truncated Evans blue ((18)F-AlF-NEB) and Evans blue (EB) dye. After local injection, both (18)F-AlF-NEB and EB form complexes with endogenous albumin in the interstitial fluid and allow for visualizing the lymphatic system. Positron emission tomography (PET) and/or optical imaging of LNs was performed in three different animal models including a hind limb inflammation model, an orthotropic breast cancer model, and a metastatic breast cancer model. In all three models, the LNs can be distinguished clearly by the apparent blue color and strong fluorescence signal from EB as well as a high-intensity PET signal from (18)F-AlF-NEB. The lymphatic vessels between the LNs can also be optically visualized. The easy preparation, excellent PET and optical imaging quality, and biosafety suggest that this combination of (18)F-AlF-NEB and EB has great potential for clinical application to map sentinel LNs and provide intraoperative guidance. PMID:25535368

  12. In vivo albumin labeling and lymphatic imaging

    PubMed Central

    Wang, Yu; Lang, Lixin; Huang, Peng; Wang, Zhe; Jacobson, Orit; Kiesewetter, Dale O.; Ali, Iqbal U.; Teng, Gaojun; Niu, Gang; Chen, Xiaoyuan

    2015-01-01

    The ability to accurately and easily locate sentinel lymph nodes (LNs) with noninvasive imaging methods would assist in tumor staging and patient management. For this purpose, we developed a lymphatic imaging agent by mixing fluorine-18 aluminum fluoride-labeled NOTA (1,4,7-triazacyclononane-N,N',N''-triacetic acid)-conjugated truncated Evans blue (18F-AlF-NEB) and Evans blue (EB) dye. After local injection, both 18F-AlF-NEB and EB form complexes with endogenous albumin in the interstitial fluid and allow for visualizing the lymphatic system. Positron emission tomography (PET) and/or optical imaging of LNs was performed in three different animal models including a hind limb inflammation model, an orthotropic breast cancer model, and a metastatic breast cancer model. In all three models, the LNs can be distinguished clearly by the apparent blue color and strong fluorescence signal from EB as well as a high-intensity PET signal from 18F-AlF-NEB. The lymphatic vessels between the LNs can also be optically visualized. The easy preparation, excellent PET and optical imaging quality, and biosafety suggest that this combination of 18F-AlF-NEB and EB has great potential for clinical application to map sentinel LNs and provide intraoperative guidance. PMID:25535368

  13. Histaminergic afferent system in the cerebellum: structure and function.

    PubMed

    Li, Bin; Zhu, Jing-Ning; Wang, Jian-Jun

    2014-01-01

    Histaminergic afferent system of the cerebellum, having been considered as an essential component of the direct hypothalamocerebellar circuits, originates from the tuberomammillary nucleus in the hypothalamus. Unlike the mossy fibers and climbing fibers, the histaminergic afferent fibers, a third type of cerebellar afferents, extend fine varicose fibers throughout the cerebellar cortex and nuclei. Histamine receptors, belonging to the family of G protein-coupled receptors, are widely present in the cerebellum. Through these histamine receptors, histamine directly excites Purkinje cells and granule cells in the cerebellar cortex, as well as the cerebellar nuclear neurons. Therefore, the histaminergic afferents parallelly modulate these dominant components in the cerebellar circuitry and consequently influence the final output of the cerebellum. In this way, the histaminergic afferent system actively participates in the cerebellum-mediated motor balance and coordination and nonsomatic functions. Accordingly, histaminergic reagents may become potential drugs for clinical treatment of cerebellar ataxia and other cerebellar disease. On the other hand, considering the hypothalamus is a high regulatory center for autonomic and visceral activities, the hypothalamocerebellar histaminergic fibers/projections, bridging the nonsomatic center to somatic structure, may play a critical role in the somatic-nonsomatic integration.

  14. Thermal nociceptive properties of trigeminal afferent neurons in rats

    PubMed Central

    2010-01-01

    Background Although nociceptive afferents innervating the body have been heavily studied form many years, much less attention has been paid to trigeminal afferent biology. In particular, very little is known concerning trigeminal nociceptor responses to heat, and almost nothing in the rat. This study uses a highly controlled and reproducible diode laser stimulator to investigate the activation of trigeminal afferents to noxious skin heating. Results The results of this experiment demonstrate that trigeminal thermonociceptors are distinct from themonociceptors innervating the limbs. Trigeminal nociceptors have considerably slower action potential conduction velocities and lower temperature thresholds than somatic afferent neurons. On the other hand, nociceptors innervating both tissue areas separate into those that respond to short pulse, high rate skin heating and those that respond to long pulse, low rate skin heating. Conclusions This paper provides the first description in the literature of the in vivo properties of thermonociceptors in rats. These finding of two separate populations aligns with the separation between C and A-delta thermonociceptors innervating the paw, but have significant differences in terms of temperature threshold and average conduction velocities. An understanding of the temperature response properties of afferent neurons innervating the paw skin have been critical in many mechanistic discoveries, some leading to new pain therapies. A clear understanding of trigeminal nociceptors may be similarly useful in the investigation of trigeminal pain mechanisms and potential therapies. PMID:20609212

  15. In vitro Functional Characterization of Mouse Colorectal Afferent Endings

    PubMed Central

    Feng, Bin; Gebhart, G.F.

    2015-01-01

    This video demonstrates in detail an in vitro single-fiber electrophysiological recording protocol using a mouse colorectum-nerve preparation. The approach allows unbiased identification and functional characterization of individual colorectal afferents. Extracellular recordings of propagated action potentials (APs) that originate from one or a few afferent (i.e., single-fiber) receptive fields (RFs) in the colorectum are made from teased nerve fiber fascicles. The colorectum is removed with either the pelvic (PN) or lumbar splanchnic (LSN) nerve attached and opened longitudinally. The tissue is placed in a recording chamber, pinned flat and perfused with oxygenated Krebs solution. Focal electrical stimulation is used to locate the colorectal afferent endings, which are further tested by three distinct mechanical stimuli (blunt probing, mucosal stroking and circumferential stretch) to functionally categorize the afferents into five mechanosensitive classes. Endings responding to none of these mechanical stimuli are categorized as mechanically-insensitive afferents (MIAs). Both mechanosensitive and MIAs can be assessed for sensitization (i.e., enhanced response, reduced threshold, and/or acquisition of mechanosensitivity) by localized exposure of RFs to chemicals (e.g., inflammatory soup (IS), capsaicin, adenosine triphosphate (ATP)). We describe the equipment and colorectum–nerve recording preparation, harvest of colorectum with attached PN or LSN, identification of RFs in the colorectum, single-fiber recording from nerve fascicles, and localized application of chemicals to the RF. In addition, challenges of the preparation and application of standardized mechanical stimulation are also discussed. PMID:25651300

  16. Semicircular Canal Geometry, Afferent Sensitivity And Animal Behavior

    PubMed Central

    Hullar, Timothy A.

    2008-01-01

    The geometry of the semicircular canals has been used in evolutionary studies to predict the behaviors of extinct animals. These predictions have relied on an assumption that the responses of the canals can be determined from their dimensions, and that an organism’s behavior can be determined from these responses. However, the relationship between a canal’s sensitivity and its size is not well known. An intraspecies comparison among canal responses in each of three species (cat, squirrel monkey, and pigeon) was undertaken to evaluate various models of canal function and determine how their dimensions may be related to afferent physiology. All models predicted the responses of the cat afferents, but the models performed less well for squirrel monkey and pigeon. Possible causes for this discrepancy include incorrectly assuming that afferent responses accurately represent canal function, or errors in current biophysical models of the canals. These findings leave open the question as to how reliably canal anatomy can be used to estimate afferent responses and how closely afferent responses are related to behavior. Other labyrinthine features—such as orientation of the horizontal canal, which is reliably held near earth-horizontal across many species—may be better to use when extrapolating the posture and related behavior of extinct animals from labyrinthine morphology. PMID:16550591

  17. Lymphatic vessels arise from specialized angioblasts within a venous niche.

    PubMed

    Nicenboim, J; Malkinson, G; Lupo, T; Asaf, L; Sela, Y; Mayseless, O; Gibbs-Bar, L; Senderovich, N; Hashimshony, T; Shin, M; Jerafi-Vider, A; Avraham-Davidi, I; Krupalnik, V; Hofi, R; Almog, G; Astin, J W; Golani, O; Ben-Dor, S; Crosier, P S; Herzog, W; Lawson, N D; Hanna, J H; Yanai, I; Yaniv, K

    2015-06-01

    How cells acquire their fate is a fundamental question in developmental and regenerative biology. Multipotent progenitors undergo cell-fate restriction in response to cues from the microenvironment, the nature of which is poorly understood. In the case of the lymphatic system, venous cells from the cardinal vein are thought to generate lymphatic vessels through trans-differentiation. Here we show that in zebrafish, lymphatic progenitors arise from a previously uncharacterized niche of specialized angioblasts within the cardinal vein, which also generates arterial and venous fates. We further identify Wnt5b as a novel lymphatic inductive signal and show that it also promotes the ‘angioblast-to-lymphatic’ transition in human embryonic stem cells, suggesting that this process is evolutionarily conserved. Our results uncover a novel mechanism of lymphatic specification, and provide the first characterization of the lymphatic inductive niche. More broadly, our findings highlight the cardinal vein as a heterogeneous structure, analogous to the haematopoietic niche in the aortic floor.

  18. Emerging trends in the pathophysiology of lymphatic contractile function.

    PubMed

    Chakraborty, Sanjukta; Davis, Michael J; Muthuchamy, Mariappan

    2015-02-01

    Lymphatic contractile dysfunction is central to a number of pathologies that affect millions of people worldwide. Due to its critical role in the process of inflammation, a dysfunctional lymphatic system also compromises the immune response, further exacerbating a number of inflammation related diseases. Despite the critical physiological functions accomplished by the transport of lymph, a complete understanding of the contractile machinery of the lymphatic system lags far behind that of the blood vasculature. However, there has been a surge of recent research focusing on different mechanisms that underlie both physiological and pathophysiological aspects of lymphatic contractile function. This review summarizes those emerging paradigms that shed some novel insights into the contractile physiology of the lymphatics in normal as well as different disease states. In addition, this review emphasizes the recent progress made in our understanding of various contractile parameters and regulatory elements that contribute to the normal functioning of the lymphatics.

  19. Visualization of lymphatic vessel development, growth, and function.

    PubMed

    Pollmann, Cathrin; Hägerling, René; Kiefer, Friedemann

    2014-01-01

    Despite their important physiological and pathophysiological functions, lymphatic endothelial cells and lymphatic vessels remain less well studied compared to the blood vascular system. Lymphatic endothelium differentiates from venous blood vascular endothelium after initial arteriovenous differentiation. Only recently by the use of light sheet microscopy, the precise mechanism of separation of the first lymphatic endothelial progenitors from the cardinal vein has been described as delamination followed by mesenchymal cell migration of lymphatic endothelial cells. Dorsolaterally of the embryonic cardinal vein, lymphatic endothelial cells reaggregate to form the first lumenized lymphatic vessels, the dorsal peripheral longitudinal vessel and the more ventrally positioned primordial thoracic duct. Despite this progress in our understanding of the first lymph vessel formation, intravital observation of lymphatic vessel behavior in the intact organism, during development and in the adult, is prerequisite to a precise understanding of this tissue. Transgenic models and two-photon microscopy, in combination with optical windows, have made live intravital imaging possible: however, new imaging modalities and novel approaches promise gentler, more physiological, and longer intravital imaging of lymphatic vessels.

  20. Lymphatic imaging: Lymphography, computed tomography and scintigraphy, 2nd ed

    SciTech Connect

    Close, M.E.; Wallace, S.

    1985-01-01

    The latest addition to the Golden's Diagnostic Radiology series deals not only with imaging of the lymphatic system but also with lymphatic anatomy, its pathophysiology, and treatment of disorders. The first two chapters deal with the history of the discovery of the lymphatic system and its normal anatomy. The section on technique contains practical information and discussion of lymphatic physiology and the pathology of lymphomas. Half of the book's 16 chapters are devoted to problems encountered in clinical imaging. The approach is both by anatomy (thorax, neck, abdomen) and pathology (benign disease, lymphoma, solid tumors).

  1. Lymphatic communication: Connexin junction, what’s your function?

    PubMed Central

    Kanady, John D.; Simon, Alexander M.

    2012-01-01

    Summary This article reviews recent findings on expression and function of connexin proteins - the structural subunits of gap junction intercellular channels in the lymphatic vasculature - both during development and in the mature lymphatic vessel. Highlighted in particular are recent mouse connexin knockout studies which show that connexins are crucial for normal lymphatic development. We discuss, in general terms, both channel-dependent as well as channel-independent functions of connexins and raise some of the many unanswered questions about the mechanism(s) of action and physiological roles of connexins in the lymphatic vasculature. PMID:22165579

  2. Adipose afferent reflex: sympathetic activation and obesity hypertension.

    PubMed

    Xiong, X-Q; Chen, W-W; Zhu, G-Q

    2014-03-01

    Excessive sympathetic activity contributes to the pathogenesis of hypertension and the progression of the related organ damage. Adipose afferent reflex (AAR) is a sympatho-excitatory reflex that the afferent activity from white adipose tissue (WAT) increases sympathetic outflow and blood pressure. Hypothalamic paraventricular nucleus (PVN or PVH) is one of the central sites in the control of the AAR, and ionotropic glutamate receptors in the nucleus mediate the AAR. The AAR is enhanced in obesity and obesity hypertension. Enhanced WAT afferent activity and AAR contribute to the excessive sympathetic activation and hypertension in obesity. Blockage of the AAR attenuates the excessive sympathetic activity and hypertension. Leptin may be one of sensors in the WAT for the AAR, and is involved in the enhanced AAR in obesity and hypertension. This review focuses on the neuroanatomical basis and physiological functions of the AAR, and the important role of the enhanced AAR in the pathogenesis of obesity hypertension.

  3. A novel role for TRPM8 in visceral afferent function.

    PubMed

    Harrington, Andrea M; Hughes, Patrick A; Martin, Christopher M; Yang, Jing; Castro, Joel; Isaacs, Nicole J; Blackshaw, L Ashley; Brierley, Stuart M

    2011-07-01

    Transient receptor potential ion channel melastatin subtype 8 (TRPM8) is activated by cold temperatures and cooling agents, such as menthol and icilin. Compounds containing peppermint are reported to reduce symptoms of bowel hypersensitivity; however, the underlying mechanisms of action are unclear. Here we determined the role of TRPM8 in colonic sensory pathways. Laser capture microdissection, quantitative reverse transcription-polymerase chain reaction (RT-PCR), immunofluorescence, and retrograde tracing were used to localise TRPM8 to colonic primary afferent neurons. In vitro extracellular single-fibre afferent recordings were used to determine the effect of TRPM8 channel activation on the chemosensory and mechanosensory function of colonic high-threshold afferent fibres. TRPM8 mRNA was present in colonic DRG neurons, whereas TRPM8 protein was present on nerve fibres throughout the wall of the colon. A subpopulation (24%, n=58) of splanchnic serosal and mesenteric afferents tested responded directly to icilin (5 μmol/L). Subsequently, icilin significantly desensitised afferents to mechanical stimulation (P<.0001; n=37). Of the splanchnic afferents responding to icilin, 21 (33%) also responded directly to the TRPV1 agonist capsaicin (3 μmol/L), and icilin reduced the direct chemosensory response to capsaicin. Icilin also prevented mechanosensory desensitization and sensitization induced by capsaicin and the TRPA1 agonist AITC (40 μmol/L), respectively. TRPM8 is present on a select population of colonic high threshold sensory neurons, which may also co-express TRPV1. TRPM8 couples to TRPV1 and TRPA1 to inhibit their downstream chemosensory and mechanosensory actions. PMID:21489690

  4. Determinants of Spatial and Temporal Coding by Semicircular Canal Afferents

    PubMed Central

    Highstein, Stephen M.; Rabbitt, Richard D.; Holstein, Gay R.; Boyle, Richard D.

    2010-01-01

    The vestibular semicircular canals are internal sensors that signal the magnitude, direction, and temporal properties of angular head motion. Fluid mechanics within the 3-canal labyrinth code the direction of movement and integrate angular acceleration stimuli over time. Directional coding is accomplished by decomposition of complex angular accelerations into 3 biomechanical components—one component exciting each of the 3 ampullary organs and associated afferent nerve bundles separately. For low-frequency angular motion stimuli, fluid displacement within each canal is proportional to angular acceleration. At higher frequencies, above the lower corner frequency, real-time integration is accomplished by viscous forces arising from the movement of fluid within the slender lumen of each canal. This results in angular velocity sensitive fluid displacements. Reflecting this, a subset of afferent fibers indeed report angular acceleration to the brain for low frequencies of head movement and report angular velocity for higher frequencies. However, a substantial number of afferent fibers also report angular acceleration, or a signal between acceleration and velocity, even at frequencies where the endolymph displacement is known to follow angular head velocity. These non-velocity-sensitive afferent signals cannot be attributed to canal biomechanics alone. The responses of non-velocity-sensitive cells include a mathematical differentiation (first-order or fractional) imparted by hair-cell and/or afferent complexes. This mathematical differentiation from velocity to acceleration cannot be attributed to hair cell ionic currents, but occurs as a result of the dynamics of synaptic transmission between hair cells and their primary afferent fibers. The evidence for this conclusion is reviewed below. PMID:15845995

  5. The afferent pupillary defect in acute optic neuritis.

    PubMed Central

    Ellis, C J

    1979-01-01

    Twenty-two patients with acute optic neuritis were studied by the techniques of infrared pupillometry and visual evoked responses (VER) to pattern reversal. A relative afferent pupillary defect was found in all cases and the magnitude of this defect was found to be related to the amplitude, but not to the latency, of the VER. During follow-up the afferent defect was found to remain persistently abnormal while other methods of clinical evaluation could not demonstrate abnormality reliably. The amplitude of the VER also remained low. PMID:501365

  6. Measurement of lymphatic function with technetium-99m-labelled polyclonal immunoglobulin.

    PubMed

    Svensson, W; Glass, D M; Bradley, D; Peters, A M

    1999-05-01

    A reliable method for measuring lymph flow in physiological units would be valuable, especially in conditions in which it is uncertain whether lymph flow is increased or decreased. The requirements of a radiopharmaceutical for such measurement include stable radionuclide labelling and rapid access to lymphatic vessels following tissue injection but no access to blood vessels. A soluble macromolecule is likely to come closest to meeting these requirements. Technetium-99m-labelled human polyclonal immunoglobulin (HIG) was therefore investigated firstly in comparison with 99mTc-labelled human serum albumin (HSA) in patients undergoing routine lymphoscintigraphy and secondly with respect to injection site in a group of volunteers with post-mastectomy oedema (PMO). Subcutaneous injection of 99mTc-HIG into the web space of a distal extremity gave images in which lymphatic vessels were more clearly defined compared with images obtained after injection of 99mTc-HSA. Lymph nodes were also more clearly defined, suggesting specific retention of HIG, possibly through Fc-mediated binding. Peripheral blood sampling showed a delayed arrival in blood of radioactivity after 99mTc-HIG compared with 99mTc-HSA, although ultimately, the blood recovery of 99mTc-HIG was significantly higher (P < 0.05) than that of 99mTc-HSA. Clearance rates of radioactivity from the injection site were not significantly different, however, between the two agents. In patients with PMO, web space injection of 99mTc-HIG gave excellent images of normal lymphatic vessels, of lymph nodes and of abnormal lymph drainage such as dermal backflow in swollen arms. In contrast, neither lymphatic vessels nor lymph nodes were visualised after injection into the skin of the dorsum of the distal forearm. Although there was no difference in clearance rates from the injection sites between normal and swollen arms with either agent in PMO, clearance was significantly faster following injection into the web space (0.11% per

  7. Lymphatic drainage and CTV in pancreatic carcinoma.

    PubMed

    Morganti, Alessio G; Cellini, Numa; Mattiucci, Gian Carlo; Macchia, Gabriella; Smaniotto, Daniela; Luzi, Stefano; Balducci, Mario; Deodato, Francesco; Valentini, Vincenzo; Trodella, Lucio

    2003-01-01

    CTV definition in exclusive or adjuvant radiation therapy of pancreatic carcinoma is essentially based on the opinion of "expert" authors and on the knowledge of lymphatic pathways. The subject has been widely debated. Radiotherapy treatments of the entire upper abdomen (liver and pancreatic region), pancreas and lymph node stations, to volumes focused on macroscopic tumor only, have been proposed. Carcinoma of exocrine pancreas is characterized by the frequent, early appearance of metastasis via the lymphatic route. Most commonly involved lymph node stations include those of the celiac trunk, superior mesenteric, peripancreatic, lumboaortic lymph nodes, those of the hepatic portal (the latter in particular for pancreatic head tumors) and of the hilum of spleen (the latter in particular for pancreatic tail tumors). The possible multicentricity of pancreatic carcinoma, most likely due to intraductal spread, should lead to the inclusion in the CTV of the entire pancreatic parenchyma. This should be considered also for the frequent perineural intra- or extrapancreatic spread of pancreatic carcinoma present also in small tumors (T1). In extrapancreatic spread the retropancreatic adipose tissue should be included in the CTV at least at the GTV level. At the present state of knowledge, in the absence of pattern of failure analysis and of comparison of different treatment approaches, in terms of the definition of volumes of interest, CTV definitions which include lymphatic drainage stations, most part of pancreatic parenchyma and retropancreatic adipose tissue seem justified especially in treatments for cure. In palliation, the CTV may be limited to the GTV and the adipose tissue behind it. PMID:15018319

  8. Lymphatic vessels: new targets for the treatment of inflammatory diseases.

    PubMed

    Dieterich, Lothar C; Seidel, Catharina D; Detmar, Michael

    2014-04-01

    The lymphatic system plays an important role in the physiological control of the tissue fluid balance and in the initiation of immune responses. Recent studies have shown that lymphangiogenesis, the growth of new lymphatic vessels and/or the expansion of existing lymphatic vessels, is a characteristic feature of acute inflammatory reactions and of chronic inflammatory diseases. In these conditions, lymphatic vessel expansion occurs at the tissue level but also within the draining lymph nodes. Surprisingly, activation of lymphatic vessel function by delivery of vascular endothelial growth factor-C exerts anti-inflammatory effects in several models of cutaneous and joint inflammation. These effects are likely mediated by enhanced drainage of extravasated fluid and inflammatory cells, but also by lymphatic vessel-mediated modulation of immune responses. Although some of the underlying mechanisms are just beginning to be identified, lymphatic vessels have emerged as important targets for the development of new therapeutic strategies to treat inflammatory conditions. In this context, it is of great interest that some of the currently used anti-inflammatory drugs also potently activate lymphatic vessels.

  9. Heterogeneity in the lymphatic vascular system and its origin.

    PubMed

    Ulvmar, Maria H; Mäkinen, Taija

    2016-09-01

    Lymphatic vessels have historically been viewed as passive conduits for fluid and immune cells, but this perspective is increasingly being revised as new functions of lymphatic vessels are revealed. Emerging evidence shows that lymphatic endothelium takes an active part in immune regulation both by antigen presentation and expression of immunomodulatory genes. In addition, lymphatic vessels play an important role in uptake of dietary fat and clearance of cholesterol from peripheral tissues, and they have been implicated in obesity and arteriosclerosis. Lymphatic vessels within different organs and in different physiological and pathological processes show a remarkable plasticity and heterogeneity, reflecting their functional specialization. In addition, lymphatic endothelial cells (LECs) of different organs were recently shown to have alternative developmental origins, which may contribute to the development of the diverse lymphatic vessel and endothelial functions seen in the adult. Here, we discuss recent developments in the understanding of heterogeneity within the lymphatic system considering the organ-specific functional and molecular specialization of LECs and their developmental origin. PMID:27357637

  10. Consensus statement on the immunohistochemical detection of ocular lymphatic vessels.

    PubMed

    Schroedl, Falk; Kaser-Eichberger, Alexandra; Schlereth, Simona L; Bock, Felix; Regenfuss, Birgit; Reitsamer, Herbert A; Lutty, Gerard A; Maruyama, Kazuichi; Chen, Lu; Lütjen-Drecoll, Elke; Dana, Reza; Kerjaschki, Dontscho; Alitalo, Kari; De Stefano, Maria Egle; Junghans, Barbara M; Heindl, Ludwig M; Cursiefen, Claus

    2014-10-01

    There is currently considerable controversy about existence and classification of "lymphatic vessels" in the eye. Some of the confusion is certainly caused by inappropriate use (or nonuse) of the correct immunohistochemical markers. Many experts in the field expressed the need for a consensus statement, and, in this perspective, authors offer arguments and solutions to reliably continue with immunohistochemical ocular lymphatic research.

  11. Heterogeneity in the lymphatic vascular system and its origin.

    PubMed

    Ulvmar, Maria H; Mäkinen, Taija

    2016-09-01

    Lymphatic vessels have historically been viewed as passive conduits for fluid and immune cells, but this perspective is increasingly being revised as new functions of lymphatic vessels are revealed. Emerging evidence shows that lymphatic endothelium takes an active part in immune regulation both by antigen presentation and expression of immunomodulatory genes. In addition, lymphatic vessels play an important role in uptake of dietary fat and clearance of cholesterol from peripheral tissues, and they have been implicated in obesity and arteriosclerosis. Lymphatic vessels within different organs and in different physiological and pathological processes show a remarkable plasticity and heterogeneity, reflecting their functional specialization. In addition, lymphatic endothelial cells (LECs) of different organs were recently shown to have alternative developmental origins, which may contribute to the development of the diverse lymphatic vessel and endothelial functions seen in the adult. Here, we discuss recent developments in the understanding of heterogeneity within the lymphatic system considering the organ-specific functional and molecular specialization of LECs and their developmental origin.

  12. Lymphatic drug delivery using engineered liposomes and solid lipid nanoparticles

    PubMed Central

    Cai, Shuang; Zhang, Qiuhong; Bagby, Taryn; Forrest, M. Laird

    2011-01-01

    The lymphatic system plays a crucial role in the immune system’s recognition and response to disease, and most solid cancers initially spread from the primary site via the tumor’s surrounding lymphatics before hematological dissemination. Hence, the lymphatic system is an important target for developing new vaccines, cancer treatments, and diagnostic agents. Targeting the lymphatic system by subcutaneous, intestinal, and pulmonary routes has been evaluated and subsequently utilized to improve lymphatic penetration and retention of drug molecules, reduce drug-related systemic toxicities, and enhance bioavailability of poorly soluble and unstable drugs. Lymphatic imaging is an essential tool for the detection and staging of cancer. New nano-based technologies offer improved detection and characterization of the nodal diseases, while new delivery devices can better target and confine treatments to tumors within the nodal space while sparing healthy tissues. This manuscript reviews recent advances in the field of lymphatic drug delivery and imaging and focuses specifically on the development ofliposomes and solid lipid nanoparticles for lymphatic introduction via the subcutaneous, intestinal, and pulmonary routes. PMID:21712055

  13. Heterogeneity in the lymphatic vascular system and its origin

    PubMed Central

    Ulvmar, Maria H.; Mäkinen, Taija

    2016-01-01

    Lymphatic vessels have historically been viewed as passive conduits for fluid and immune cells, but this perspective is increasingly being revised as new functions of lymphatic vessels are revealed. Emerging evidence shows that lymphatic endothelium takes an active part in immune regulation both by antigen presentation and expression of immunomodulatory genes. In addition, lymphatic vessels play an important role in uptake of dietary fat and clearance of cholesterol from peripheral tissues, and they have been implicated in obesity and arteriosclerosis. Lymphatic vessels within different organs and in different physiological and pathological processes show a remarkable plasticity and heterogeneity, reflecting their functional specialization. In addition, lymphatic endothelial cells (LECs) of different organs were recently shown to have alternative developmental origins, which may contribute to the development of the diverse lymphatic vessel and endothelial functions seen in the adult. Here, we discuss recent developments in the understanding of heterogeneity within the lymphatic system considering the organ-specific functional and molecular specialization of LECs and their developmental origin. PMID:27357637

  14. Effects of LDL Receptor Modulation on Lymphatic Function

    PubMed Central

    Milasan, Andreea; Dallaire, François; Mayer, Gaétan; Martel, Catherine

    2016-01-01

    Atherosclerosis is driven by the accumulation of immune cells and cholesterol in the arterial wall. Although recent studies have shown that lymphatic vessels play an important role in macrophage reverse cholesterol transport, the specific underlying mechanisms of this physiological feature remain unknown. In the current report, we sought to better characterize the lymphatic dysfunction that is associated with atherosclerosis by studying the physiological and temporal origins of this impairment. First, we assessed that athero-protected Pcsk9−/− mice exhibited improved collecting lymphatic vessel function throughout age when compared to WT mice for up to six months, while displaying enhanced expression of LDLR on lymphatic endothelial cells. Lymphatic dysfunction was present before the atherosclerotic lesion formation in a mouse model that is predisposed to develop atherosclerosis (Ldlr−/−; hApoB100+/+). This dysfunction was presumably associated with a defect in the collecting lymphatic vessels in a non-specific cholesterol- but LDLR-dependent manner. Treatment with a selective VEGFR-3 agonist rescued this impairment observed early in the onset of this arterial disease. We suggest that LDLR modulation is associated with early atherosclerosis-related lymphatic dysfunction, and bring forth a pleiotropic role for PCSK9 in lymphatic function. Our study unveils new potential therapeutic targets for the prevention and treatment of atherosclerosis. PMID:27279328

  15. Ventral Tegmental Area Afferents and Drug-Dependent Behaviors

    PubMed Central

    Oliva, Idaira; Wanat, Matthew J.

    2016-01-01

    Drug-related behaviors in both humans and rodents are commonly thought to arise from aberrant learning processes. Preclinical studies demonstrate that the acquisition and expression of many drug-dependent behaviors involves the ventral tegmental area (VTA), a midbrain structure comprised of dopamine, GABA, and glutamate neurons. Drug experience alters the excitatory and inhibitory synaptic input onto VTA dopamine neurons, suggesting a critical role for VTA afferents in mediating the effects of drugs. In this review, we present evidence implicating the VTA in drug-related behaviors, highlight the diversity of neuronal populations in the VTA, and discuss the behavioral effects of selectively manipulating VTA afferents. Future experiments are needed to determine which VTA afferents and what neuronal populations in the VTA mediate specific drug-dependent behaviors. Further studies are also necessary for identifying the afferent-specific synaptic alterations onto dopamine and non-dopamine neurons in the VTA following drug administration. The identification of neural circuits and adaptations involved with drug-dependent behaviors can highlight potential neural targets for pharmacological and deep brain stimulation interventions to treat substance abuse disorders. PMID:27014097

  16. Changes in monkey horizontal semicircular canal afferent responses after spaceflight

    NASA Technical Reports Server (NTRS)

    Correia, M. J.; Perachio, A. A.; Dickman, J. D.; Kozlovskaia, I. B.; Sirota, M. G.; Iakushin, S. B.; Beloozerova, I. N.

    1992-01-01

    Extracellular responses from single horizontal semicircular canal afferents in two rhesus monkeys were studied after recovery from a 14-day biosatellite (Cosmos 2044) orbital spaceflight. On the 1st postflight day, the mean gain for 9 different horizontal canal afferents, tested using one or several different passive yaw rotation waveforms, was nearly twice that for 20 horizontal canal afferents similarly tested during preflight and postflight control studies. Adaptation of the afferent response to passive yaw rotation on the 1st postflight day was also greater. These results suggest that at least one component of the vestibular end organ (the semicircular canals) is transiently modified after exposure to 14 days of microgravity. It is unclear whether the changes are secondary to other effects of microgravity, such as calcium loss, or an adaptive response. If the response is adaptive, then this report is the first evidence that the response of the vestibular end organ may be modified (presumably by the central nervous system via efferent connections) after prolonged unusual vestibular stimulation. If this is the case, the sites of plasticity of vestibular responses may not be exclusively within central nervous system vestibular structures, as previously believed.

  17. Neck muscle afferents influence oromotor and cardiorespiratory brainstem neural circuits.

    PubMed

    Edwards, I J; Lall, V K; Paton, J F; Yanagawa, Y; Szabo, G; Deuchars, S A; Deuchars, J

    2015-01-01

    Sensory information arising from the upper neck is important in the reflex control of posture and eye position. It has also been linked to the autonomic control of the cardiovascular and respiratory systems. Whiplash associated disorders (WAD) and cervical dystonia, which involve disturbance to the neck region, can often present with abnormalities to the oromotor, respiratory and cardiovascular systems. We investigated the potential neural pathways underlying such symptoms. Simulating neck afferent activity by electrical stimulation of the second cervical nerve in a working heart brainstem preparation (WHBP) altered the pattern of central respiratory drive and increased perfusion pressure. Tracing central targets of these sensory afferents revealed projections to the intermedius nucleus of the medulla (InM). These anterogradely labelled afferents co-localised with parvalbumin and vesicular glutamate transporter 1 indicating that they are proprioceptive. Anterograde tracing from the InM identified projections to brain regions involved in respiratory, cardiovascular, postural and oro-facial behaviours--the neighbouring hypoglossal nucleus, facial and motor trigeminal nuclei, parabrachial nuclei, rostral and caudal ventrolateral medulla and nucleus ambiguus. In brain slices, electrical stimulation of afferent fibre tracts lateral to the cuneate nucleus monosynaptically excited InM neurones. Direct stimulation of the InM in the WHBP mimicked the response of second cervical nerve stimulation. These results provide evidence of pathways linking upper cervical sensory afferents with CNS areas involved in autonomic and oromotor control, via the InM. Disruption of these neuronal pathways could, therefore, explain the dysphagic and cardiorespiratory abnormalities which may accompany cervical dystonia and WAD. PMID:24595534

  18. Cell recruitment and antigen trafficking in afferent lymph after injection of antigen and poly(I:C) containing liposomes, in aqueous or oil-based formulations.

    PubMed

    de Veer, Michael; Neeland, Melanie; Burke, Melissa; Pleasance, Jill; Nathanielsz, Jackie; Elhay, Martin; Meeusen, Els

    2013-02-01

    After vaccination, innate cell populations transport antigen from the tissue, via the afferent lymphatic vessels, into the local lymph node where they provide critical signals for the generation of an adaptive immune response. The present study uses a unique lymphatic cannulation model to examine, in real time, changes in afferent lymph after injection of a liposome-based delivery system, incorporating diptheria toxoid (DT) and the innate stimulator, poly(I:C). There was a dramatic but temporal recruitment of innate cell populations over time, with neutrophils and monocytes peaking at 6h and 28h post vaccination respectively. The number of dendritic cells (DC) did not increase over the 198h time period, while lymphocytes were slightly elevated at the latest times, indicating the start of an adaptive response. Monocytes and neutrophils were the predominant cell types transporting antigen at the early time points while DC were the most dominant antigen-carrying cells after 78h, predominantly the Sirp-α(high) DC subtype. Resuspending liposomes in oil instead of aqueous solutions has recently been shown to dramatically increase the level and persistence of an immune response and forms the basis of the novel adjuvant formulations, Vaccimax© and Depovax©. In the present study, formulation of the DT and poly(I:C) containing liposomes in an oil carrier dramatically reduced antigen transport to the draining lymph nodes. Examination of the injection site revealed the creation of an ectopic lymphoid tissue with prominent antigen foci and organized lymphoid cells, providing a possible mechanism for the persistence of an immune response in liposome-in-oil adjuvant formulation. Together, the present studies demonstrate the real-time innate in vivo response to vaccination of two novel liposome-based adjuvant systems and the dramatic effect of different carrier formulations.

  19. Tissue contribution to the mechanical features of diaphragmatic initial lymphatics

    PubMed Central

    Moriondo, Andrea; Boschetti, Federica; Bianchin, Francesca; Lattanzio, Simone; Marcozzi, Cristiana; Negrini, Daniela

    2010-01-01

    The role of the mechanical properties of the initial lymphatic wall and of the surrounding tissue in supporting lymph formation and/or progression was studied in six anaesthetized, neuromuscularly blocked and mechanically ventilated rats. After mid-sternal thoracotomy, submesothelial initial lymphatics were identified on the pleural diaphragmatic surface through stereomicroscopy. An ‘in vivo’ lymphatic segment was prepared by securing two surgical threads around the vessel at a distance of ∼2.5 mm leaving the vessel in place. Two glass micropipettes were inserted into the lumen, one for intraluminar injections of 4.6 nl saline boluses and one for hydraulic pressure (Plymph) recording. The compliance of the vessel wall (Clymph) was calculated as the slope of the plot describing the change in segment volume as a function of the post-injection Plymph changes. Two superficial lymphatic vessel populations with a significantly different Clymph (6.7 ± 1.6 and 1.5 ± 0.4 nl mmHg−1 (mean ± s.e.m.), P < 0.001) were identified. In seven additional rats, the average elastic modulus of diaphragmatic tissue strips was determined by uniaxial tension tests to be 1.7 ± 0.3 MPa. Clymph calculated for an initial lymphatic completely surrounded by isotropic tissue was 0.068 nl mmHg−1, i.e. two orders of magnitude lower than in submesothelial lymphatics. Modelling of stress distribution in the lymphatic wall suggests that compliant vessels may act as reservoirs accommodating large absorbed fluid volumes, while lymphatics with stiffer walls serve to propel fluid through the lumen of the lymphatic vessel by taking advantage of the more efficient mechanical transmission of tissue stresses to the lymphatic lumen. PMID:20724369

  20. Lymphatic albumin clearance from psoriatic skin

    SciTech Connect

    Staberg, B.; Klemp, P.; Aasted, M.; Worm, A.M.; Lund, P.

    1983-12-01

    In nine patients with untreated psoriasis vulgaris, human serum albumin labelled with /sup 125/I or /sup 131/I was injected intradermally in symmetrically located involved and uninvolved skin. The activity of the depots was followed by external detection, and the arrival of labelled albumin in plasma was monitored. In involved psoriatic skin the local mean half-time (T1/2) for tracer disappearance was 20.8 +/- 8.2 (S.D.) hr and in clinically normal skin, 29.1 +/- 9.6 (S.D.) hr. The difference was significant (p less than 0.002). Accordingly, the tracer from involved skin reached higher plasma levels than the tracer from uninvolved skin. However, under slight lymphatic stasis the appearance rate of radiolabelled albumin in plasma from both tissues was minimal during 1 to 2 hours after the injection, indicating that a local direct transvascular drainage of plasma albumin from the interstitium of diseased and normal skin was negligible. We conclude that the previously demonstrated increased extravasation of plasma proteins in involved psoriatic skin is compensated by an increased lymphatic drainage of plasma proteins, and not by an increased local transvascular return.

  1. Thymus cell antigen 1 (Thy1, CD90) is expressed by lymphatic vessels and mediates cell adhesion to lymphatic endothelium.

    PubMed

    Jurisic, Giorgia; Iolyeva, Maria; Proulx, Steven T; Halin, Cornelia; Detmar, Michael

    2010-10-15

    The lymphatic vascular system plays an important role in inflammation and cancer progression, although the molecular mechanisms involved are poorly understood. As determined by comparative transcriptional profiling studies of ex vivo isolated mouse intestinal lymphatic endothelial cells versus blood vascular endothelial cells, thymus cell antigen 1 (Thy1, CD90) was expressed at much higher levels in lymphatic endothelial cells than in blood vascular endothelial cells. These findings were confirmed by quantitative PCR, and at the protein level by FACS and immunofluorescence analyses. Thy1 was also strongly expressed by tumor-associated lymphatic vessels, as evaluated in a B16 melanoma footpad model in mice. Blockade of Thy1 inhibited tumor cell adhesion to cultured mouse lymphatic endothelial cells. Importantly, treatment of human dermal microvascular endothelial cells with tumor necrosis factor or phorbol 12-myristate 13-acetate resulted in Thy1 upregulation in podoplanin-expressing lymphatic endothelial cells, but not in podoplanin-negative blood vascular endothelial cells. Moreover, adhesion of human polymorphonuclear and mononuclear leukocytes to human lymphatic endothelial cells was Thy1-dependent. Together, these results identify Thy1 as a novel lymphatic vessel expressed gene and suggest its potential role in the cell adhesion processes required for tumor progression and inflammation.

  2. Nature's rheologists: Lymphatic endothelial cells control migration in response to shear stress

    NASA Astrophysics Data System (ADS)

    Fuller, Gerald; Dunn, Alex; Surya, Vinay

    2015-03-01

    Endothelial cells (ECs) line the inner surface of blood and lymphatic vessels and are sensitive to fluid flow as part of their physiological function. EC organization, migration and vessel development are profoundly influenced by shear stresses, with important implications in cardiovascular disease and tumor metastasis. How ECs sense fluid flow is a central and unanswered question in cardiovascular biology. We developed a high-throughput live-cell flow chamber that models the gradients in wall shear stress experienced by ECs in vivo. Live-cell imaging allows us to probe cellular responses to flow, most notably EC migration, which has a key role in vessel remodeling. We find that most EC subtypes, including ECs from the venous, arterial, and microvascular systems, migrate in the flow direction. In contrast, human lymphatic microvascular ECs (hLMVECs) migrate against flow and up spatial gradients in wall shear stress. Further experiments reveal that hLMVECs are sensitive to the magnitude, direction, and the local spatial gradients in wall shear stress. Lastly, recent efforts have aimed to link this directional migration to spatial gradients in cell-mediated small molecule emission that may be linked to the gradient in wall shear stress.

  3. Pump function curve shape for a model lymphatic vessel.

    PubMed

    Bertram, C D; Macaskill, C; Moore, J E

    2016-07-01

    The transport capacity of a contractile segment of lymphatic vessel is defined by its pump function curve relating mean flow-rate and adverse pressure difference. Numerous system characteristics affect curve shape and the magnitude of the generated flow-rates and pressures. Some cannot be varied experimentally, but their separate and interacting effects can be systematically revealed numerically. This paper explores variations in the rate of change of active tension and the form of the relation between active tension and muscle length, factors not known from experiment to functional precision. Whether the pump function curve bends toward or away from the origin depends partly on the curvature of the passive pressure-diameter relation near zero transmural pressure, but rather more on the form of the relation between active tension and muscle length. A pump function curve bending away from the origin defines a well-performing pump by maximum steady output power. This behaviour is favoured by a length/active-tension relationship which sustains tension at smaller lengths. Such a relationship also favours high peak mechanical efficiency, defined as output power divided by the input power obtained from the lymphangion diameter changes and active-tension time-course. The results highlight the need to pin down experimentally the form of the length/active-tension relationship. PMID:27185045

  4. Rho Kinase Enhances Contractions of Rat Mesenteric Collecting Lymphatics

    PubMed Central

    Kurtz, Kristine H.; Souza-Smith, Flavia M.; Moor, Andrea N.; Breslin, Jerome W.

    2014-01-01

    The mechanisms that control phasic and tonic contractions of lymphatic vessels are poorly understood. We hypothesized that rho kinase ROCK, previously shown to increase calcium (Ca2+) sensitivity in vascular smooth muscle, enhances lymphatic contractile activity in a similar fashion. Contractions of isolated rat mesenteric lymphatic vessels were observed at a luminal pressure of 2 cm H2O in a 37°C bath. The expression of ROCK in isolated rat mesenteric lymphatic vessels was assessed by Western blotting and confocal microscopy. The role of ROCK in contractile function was tested using two specific yet structurally distinct inhibitors: H1152 (0.1–10 μM) and Y-27632 (0.5–50 μM). In addition, lymphatics were transfected with constitutively active (ca)-ROCK protein (2 μg/ml) to assess gain of contractile function. Vessel diameter and the concentration of intracellular free Ca2+ ([Ca2+]i) were simultaneously measured in a subset of isolated lymphatics loaded with the Ca2+-sensing dye fura-2. The results show expression of both the ROCK1 and ROCK2 isoforms in lymphatic vessels. Inhibition of ROCK increased lymphatic end diastolic diameter and end systolic diameter in a concentration-dependent manner. Significant reductions in lymphatic tone and contraction amplitude were observed after treatment 1–10 μM H1152 or 25–50 μM Y-27632. H1152 (10 μM) also significantly reduced contraction frequency. Transient increases in [Ca2+]i preceded each phasic contraction, however this pattern was disrupted by either 10 μM H1152 or 50 μM Y-27632 in the majority of lymphatics studied. The significant decrease in tone caused by H1152 or Y-27632 was not associated with a significant change in the basal [Ca2+]i between transients. Transfection with ca-ROCK protein enhanced lymphatic tone, but was not associated with a significant change in basal [Ca2+]i. Our data suggest that ROCK mediates normal tonic constriction and influences phasic contractions in lymphatics. We propose

  5. Rho kinase enhances contractions of rat mesenteric collecting lymphatics.

    PubMed

    Kurtz, Kristine H; Souza-Smith, Flavia M; Moor, Andrea N; Breslin, Jerome W

    2014-01-01

    The mechanisms that control phasic and tonic contractions of lymphatic vessels are poorly understood. We hypothesized that rho kinase ROCK, previously shown to increase calcium (Ca2+) sensitivity in vascular smooth muscle, enhances lymphatic contractile activity in a similar fashion. Contractions of isolated rat mesenteric lymphatic vessels were observed at a luminal pressure of 2 cm H2O in a 37°C bath. The expression of ROCK in isolated rat mesenteric lymphatic vessels was assessed by Western blotting and confocal microscopy. The role of ROCK in contractile function was tested using two specific yet structurally distinct inhibitors: H1152 (0.1-10 μM) and Y-27632 (0.5-50 μM). In addition, lymphatics were transfected with constitutively active (ca)-ROCK protein (2 μg/ml) to assess gain of contractile function. Vessel diameter and the concentration of intracellular free Ca2+ ([Ca2+]i) were simultaneously measured in a subset of isolated lymphatics loaded with the Ca2+-sensing dye fura-2. The results show expression of both the ROCK1 and ROCK2 isoforms in lymphatic vessels. Inhibition of ROCK increased lymphatic end diastolic diameter and end systolic diameter in a concentration-dependent manner. Significant reductions in lymphatic tone and contraction amplitude were observed after treatment 1-10 μM H1152 or 25-50 μM Y-27632. H1152 (10 μM) also significantly reduced contraction frequency. Transient increases in [Ca2+]i preceded each phasic contraction, however this pattern was disrupted by either 10 μM H1152 or 50 μM Y-27632 in the majority of lymphatics studied. The significant decrease in tone caused by H1152 or Y-27632 was not associated with a significant change in the basal [Ca2+]i between transients. Transfection with ca-ROCK protein enhanced lymphatic tone, but was not associated with a significant change in basal [Ca2+]i. Our data suggest that ROCK mediates normal tonic constriction and influences phasic contractions in lymphatics. We propose that

  6. Thresholds of cutaneous afferents related to perceptual threshold across the human foot sole.

    PubMed

    Strzalkowski, Nicholas D J; Mildren, Robyn L; Bent, Leah R

    2015-10-01

    Perceptual thresholds are known to vary across the foot sole, despite a reported even distribution in cutaneous afferents. Skin mechanical properties have been proposed to account for these differences; however, a direct relationship between foot sole afferent firing, perceptual threshold, and skin mechanical properties has not been previously investigated. Using the technique of microneurography, we recorded the monofilament firing thresholds of cutaneous afferents and associated perceptual thresholds across the foot sole. In addition, receptive field hardness measurements were taken to investigate the influence of skin hardness on these threshold measures. Afferents were identified as fast adapting [FAI (n = 48) or FAII (n = 13)] or slowly adapting [SAI (n = 21) or SAII (n = 20)], and were grouped based on receptive field location (heel, arch, metatarsals, toes). Overall, perceptual thresholds were found to most closely align with firing thresholds of FA afferents. In contrast, SAI and SAII afferent firing thresholds were found to be significantly higher than perceptual thresholds and are not thought to mediate monofilament perceptual threshold across the foot sole. Perceptual thresholds and FAI afferent firing thresholds were significantly lower in the arch compared with other regions, and skin hardness was found to positively correlate with both FAI and FAII afferent firing and perceptual thresholds. These data support a perceptual influence of skin hardness, which is likely the result of elevated FA afferent firing threshold at harder foot sole sites. The close coupling between FA afferent firing and perceptual threshold across foot sole indicates that small changes in FA afferent firing can influence perceptual thresholds.

  7. Lymphatic vessels regulate immune microenvironments in human and murine melanoma.

    PubMed

    Lund, Amanda W; Wagner, Marek; Fankhauser, Manuel; Steinskog, Eli S; Broggi, Maria A; Spranger, Stefani; Gajewski, Thomas F; Alitalo, Kari; Eikesdal, Hans P; Wiig, Helge; Swartz, Melody A

    2016-09-01

    Lymphatic remodeling in tumor microenvironments correlates with progression and metastasis, and local lymphatic vessels play complex and poorly understood roles in tumor immunity. Tumor lymphangiogenesis is associated with increased immune suppression, yet lymphatic vessels are required for fluid drainage and immune cell trafficking to lymph nodes, where adaptive immune responses are mounted. Here, we examined the contribution of lymphatic drainage to tumor inflammation and immunity using a mouse model that lacks dermal lymphatic vessels (K14-VEGFR3-Ig mice). Melanomas implanted in these mice grew robustly, but exhibited drastically reduced cytokine expression and leukocyte infiltration compared with those implanted in control animals. In the absence of local immune suppression, transferred cytotoxic T cells more effectively controlled tumors in K14-VEGFR3-Ig mice than in control mice. Furthermore, gene expression analysis of human melanoma samples revealed that patient immune parameters are markedly stratified by levels of lymphatic markers. This work suggests that the establishment of tumor-associated inflammation and immunity critically depends on lymphatic vessel remodeling and drainage. Moreover, these results have implications for immunotherapies, the efficacies of which are regulated by the tumor immune microenvironment. PMID:27525437

  8. Interaction of tumor cells and lymphatic vessels in cancer progression.

    PubMed

    Alitalo, A; Detmar, M

    2012-10-18

    Metastatic spread of cancer through the lymphatic system affects hundreds of thousands of patients yearly. Growth of new lymphatic vessels, lymphangiogenesis, is activated in cancer and inflammation, but is largely inactive in normal physiology, and therefore offers therapeutic potential. Key mediators of lymphangiogenesis have been identified in developmental studies. During embryonic development, lymphatic endothelial cells derive from the blood vascular endothelium and differentiate under the guidance of lymphatic-specific regulators, such as the prospero homeobox 1 transcription factor. Vascular endothelial growth factor-C (VEGF-C) and VEGF receptor 3 signaling are essential for the further development of lymphatic vessels and therefore they provide a promising target for inhibition of tumor lymphangiogenesis. Lymphangiogenesis is important for the progression of solid tumors as shown for melanoma and breast cancer. Tumor cells may use chemokine gradients as guidance cues and enter lymphatic vessels through intercellular openings between endothelial cell junctions or, possibly, by inducing larger discontinuities in the endothelial cell layer. Tumor-draining sentinel lymph nodes show enhanced lymphangiogenesis even before cancer metastasis and they may function as a permissive 'lymphovascular niche' for the survival of metastatic cells. Although our current knowledge indicates that the development of anti-lymphangiogenic therapies may be beneficial for the treatment of cancer patients, several open questions remain with regard to the frequency, mechanisms and biological importance of lymphatic metastases.

  9. Pkd1 regulates lymphatic vascular morphogenesis during development

    PubMed Central

    Coxam, Baptiste; Sabine, Amélie; Bower, Neil I.; Smith, Kelly A.; Pichol-Thievend, Cathy; Skoczylas, Renae; Astin, Jonathan W.; Frampton, Emmanuelle; Jaquet, Muriel; Crosier, Philip S.; Parton, Robert G.; Harvey, Natasha L.; Petrova, Tatiana V.; Schulte-Merker, Stefan; Francois, Mathias; Hogan, Benjamin M.

    2016-01-01

    Lymphatic vessels arise during development through sprouting of precursor cells from veins, which is regulated by well-studied signaling and transcriptional mechanisms. Less well understood is the ongoing elaboration of vessels to form a network. This involves cell polarisation, coordinated migration, adhesion, mixing, regression and cell shape rearrangements. We identified a zebrafish mutant, lymphatic and cardiac defects 1 (lyc1), with reduced lymphatic vessel development. We found a mutation in polycystic kidney disease 1a to be responsible for the phenotype. PKD1 is the most frequently mutated gene in autosomal dominant polycystic kidney disease (ADPKD). Initial sprouting of lymphatic precursors is normal in lyc1 mutants, but ongoing migration fails. Loss of Pkd1 in mice also has no effect on sprouting of precursors but leads to failed morphogenesis of the subcutaneous lymphatic network. Individual lymphatic endothelial cells display defective polarity, elongation and adherens junctions. This work identifies a highly selective and unexpected role for Pkd1 in lymphatic vessel morphogenesis during development. PMID:24767999

  10. Low-cost microcontroller platform for studying lymphatic biomechanics in vitro

    PubMed Central

    Kornuta, Jeffrey A.; Nipper, Matthew E.; Dixon, J. Brandon

    2012-01-01

    The pumping innate to collecting lymphatic vessels routinely exposes the endothelium to oscillatory wall shear stress and other dynamic forces. However, studying the mechanical sensitivity of the lymphatic endothelium remains a difficult task due to limitations of commercial or custom systems to apply a variety of time-varying stresses in vitro. Current biomechanical in vitro testing devices are very expensive, limited in capability, or highly complex; rendering them largely inaccessible to the endothelial cell biology community. To address these short-comings, the authors propose a reliable, low-cost platform for augmenting the capabilities of commercially available pumps to produce a wide variety of flow rate waveforms. In particular, the Arduino Uno, a microcontroller development board, is used to provide open-loop control of a digital peristaltic pump using precisely-timed serial commands. In addition, the flexibility of this platform is further demonstrated through its support of a custom-built cell-straining device capable of producing oscillatory strains with varying amplitudes and frequencies. Hence, this microcontroller development board is shown to be an inexpensive, precise, and easy-to-use tool for supplementing in vitro assays to quantify the effects of biomechanical forces on lymphatic endothelial cells. PMID:23178036

  11. Low-cost microcontroller platform for studying lymphatic biomechanics in vitro.

    PubMed

    Kornuta, Jeffrey A; Nipper, Matthew E; Dixon, J Brandon

    2013-01-01

    The pumping innate to collecting lymphatic vessels routinely exposes the endothelium to oscillatory wall shear stress and other dynamic forces. However, studying the mechanical sensitivity of the lymphatic endothelium remains a difficult task due to limitations of commercial or custom systems to apply a variety of time-varying stresses in vitro. Current biomechanical in vitro testing devices are very expensive, limited in capability, or highly complex; rendering them largely inaccessible to the endothelial cell biology community. To address these shortcomings, the authors propose a reliable, low-cost platform for augmenting the capabilities of commercially available pumps to produce a wide variety of flow rate waveforms. In particular, the Arduino Uno, a microcontroller development board, is used to provide open-loop control of a digital peristaltic pump using precisely timed serial commands. In addition, the flexibility of this platform is further demonstrated through its support of a custom-built cell-straining device capable of producing oscillatory strains with varying amplitudes and frequencies. Hence, this microcontroller development board is shown to be an inexpensive, precise, and easy-to-use tool for supplementing in vitro assays to quantify the effects of biomechanical forces on lymphatic endothelial cells.

  12. Variations in lung lymphatic drainage into the inferior tracheobronchial lymph nodes junction: Applications in lung cancer.

    PubMed

    Ndiaye, Assane; Dimarino, Vincent; Ndiaye, Aïnina; Gaye, Magaye; Ba, Papa Salmane; Nazarian, Serge

    2016-10-01

    The group of inferior tracheobronchial lymph nodes (ITB) is a lymphatic junction through which the lymph from both lungs is carried. Lymphatic activity in this area can be used to assess the lymphatic spreading of lung cancers. Our aim was to quantify lymph drainage from the lung segments towards the ITB group and to determine the direction of the lymph flow into other mediastinal and abdominal lymph nodes. We injected dye directly into the subpleural lymphatic vessels in 100 lung segments of 25 fresh cadaver subjects; the cadavers were then dissected. Thirty-eight segments (38%) drained into the ITB group in 18 subjects. The drainage into the ITB group involved 15.6% of the upper lobe segments, 87.5% of the middle lobe segments, and 70.6% of the lower lobe segments in the right lung. On the left, 6.9% of the upper lobe segments and 83.3% of the lower lobe segments were drained into the ITB group. For three subjects, the dye did not pass beyond the ITB group. The efferent vessels of the ITB group drained towards the right paratracheal and tracheoesophageal chains in 12 subjects and through the left ascending recurrent chain in five subjects. For six subjects, the efferent channels reached the abdominal lymph nodes. A contralateral drainage involved 14 segments (36%). The size and variety of the segments that drain into the ITB group, coupled with the efferent contralateral mediastinal and abdominal pathways, account for the severity of metastasis to this area. Clin. Anat. 29:955-962, 2016. © 2016 Wiley Periodicals, Inc. PMID:27480071

  13. Cdk5 controls lymphatic vessel development and function by phosphorylation of Foxc2.

    PubMed

    Liebl, Johanna; Zhang, Siwei; Moser, Markus; Agalarov, Yan; Demir, Cansaran Saygili; Hager, Bianca; Bibb, James A; Adams, Ralf H; Kiefer, Friedemann; Miura, Naoyuki; Petrova, Tatiana V; Vollmar, Angelika M; Zahler, Stefan

    2015-01-01

    The lymphatic system maintains tissue fluid balance, and dysfunction of lymphatic vessels and valves causes human lymphedema syndromes. Yet, our knowledge of the molecular mechanisms underlying lymphatic vessel development is still limited. Here, we show that cyclin-dependent kinase 5 (Cdk5) is an essential regulator of lymphatic vessel development. Endothelial-specific Cdk5 knockdown causes congenital lymphatic dysfunction and lymphedema due to defective lymphatic vessel patterning and valve formation. We identify the transcription factor Foxc2 as a key substrate of Cdk5 in the lymphatic vasculature, mechanistically linking Cdk5 to lymphatic development and valve morphogenesis. Collectively, our findings show that Cdk5-Foxc2 interaction represents a critical regulator of lymphatic vessel development and the transcriptional network underlying lymphatic vascular remodeling. PMID:26027726

  14. Cdk5 controls lymphatic vessel development and function by phosphorylation of Foxc2.

    PubMed

    Liebl, Johanna; Zhang, Siwei; Moser, Markus; Agalarov, Yan; Demir, Cansaran Saygili; Hager, Bianca; Bibb, James A; Adams, Ralf H; Kiefer, Friedemann; Miura, Naoyuki; Petrova, Tatiana V; Vollmar, Angelika M; Zahler, Stefan

    2015-06-01

    The lymphatic system maintains tissue fluid balance, and dysfunction of lymphatic vessels and valves causes human lymphedema syndromes. Yet, our knowledge of the molecular mechanisms underlying lymphatic vessel development is still limited. Here, we show that cyclin-dependent kinase 5 (Cdk5) is an essential regulator of lymphatic vessel development. Endothelial-specific Cdk5 knockdown causes congenital lymphatic dysfunction and lymphedema due to defective lymphatic vessel patterning and valve formation. We identify the transcription factor Foxc2 as a key substrate of Cdk5 in the lymphatic vasculature, mechanistically linking Cdk5 to lymphatic development and valve morphogenesis. Collectively, our findings show that Cdk5-Foxc2 interaction represents a critical regulator of lymphatic vessel development and the transcriptional network underlying lymphatic vascular remodeling.

  15. Autoimmune antibodies in chronic lymphatic leukaemia.

    PubMed

    Lewis, C M; Pegrum, G D

    1978-01-01

    In chronic lymphocytic leukaemia a factor in patients' serum enhances the in vitro viability of the abnormal cells and this has been identified as an antibody. The activity of this factor can be removed by interaction with anti-immunoglobulin and by ammonium sulphate precipitation with a degree of saturation in excess of 46%. Cohn fractionation and chromatography with A-50 Sephadex show that the factor is not a complex but an immunoglobulin. No activity is removed after reaction of sera with 2-mercapto-ethanol and di-thiothreitol. The evidence therefore suggests that a gamma-G immunoglobulin is involved. Concentrated washings from the leukaemic cells behave in exactly the same way as patients' sera and activity is retained in the same fraction during precipitation and purification procedure. The extensive cross-reactivity of the sera suggests a common chronic lymphatic leukaemic antibody and it is considered that an active autoimmune response may be an integral part of the disease.

  16. Lymphatic Vessels, Inflammation, and Immunity in Skin Cancer

    PubMed Central

    Lund, Amanda W.; Medler, Terry R.; Leachman, Sancy A.; Coussens, Lisa M.

    2015-01-01

    Skin is a highly ordered immune organ that coordinates rapid responses to external insult while maintaining self-tolerance. In healthy tissue, lymphatic vessels drain fluid and coordinate local immune responses; however, environmental factors induce lymphatic vessel dysfunction, leading to lymph stasis and perturbed regional immunity. These same environmental factors drive the formation of local malignancies, which are also influenced by local inflammation. Herein, we discuss clinical and experimental evidence supporting the tenet that lymphatic vessels participate in regulation of cutaneous inflammation and immunity, are important contributors to malignancy and potential biomarkers and targets for immunotherapy. PMID:26552413

  17. Lymphatic vascular morphogenesis in development, physiology, and disease.

    PubMed

    Schulte-Merker, Stefan; Sabine, Amélie; Petrova, Tatiana V

    2011-05-16

    The lymphatic vasculature constitutes a highly specialized part of the vascular system that is essential for the maintenance of interstitial fluid balance, uptake of dietary fat, and immune response. Recently, there has been an increased awareness of the importance of lymphatic vessels in many common pathological conditions, such as tumor cell dissemination and chronic inflammation. Studies of embryonic development and genetically engineered animal models coupled with the discovery of mutations underlying human lymphedema syndromes have contributed to our understanding of mechanisms regulating normal and pathological lymphatic morphogenesis. It is now crucial to use this knowledge for the development of novel therapies for human diseases.

  18. Laparoscopic excision of a retroperitoneal lymphatic malformation in a newborn.

    PubMed

    Solari, Valeria; Mullassery, Dhanya; Lansdale, Nick; Jesudason, Edwin C

    2011-02-01

    Abdominal lymphatic malformations may be challenging to eradicate. Retroperitoneal lesions may more difficult to resect than mesenteric ones; however, the latter may predispose to intestinal volvulus, leading to calls for their prompt excision. Such lesions identified perinatally may pose particular challenges: in one case, respiratory failure caused by abdominal distension required emergency drainage followed by later laparoscopic excision; laparoscopy has also been used promptly to diagnose and resect neonatal mesenteric lymphatic malformations with their inherent volvulus risk. We illustrate that even if neonatal laparoscopy identifies a retroperitoneal rather than mesenteric lymphatic malformation, curative endosurgical excision remains feasible.

  19. Distinct recurrent versus afferent dynamics in cortical visual processing.

    PubMed

    Reinhold, Kimberly; Lien, Anthony D; Scanziani, Massimo

    2015-12-01

    How intracortical recurrent circuits in mammalian sensory cortex influence dynamics of sensory representation is not understood. Previous methods could not distinguish the relative contributions of recurrent circuits and thalamic afferents to cortical dynamics. We accomplish this by optogenetically manipulating thalamus and cortex. Over the initial 40 ms of visual stimulation, excitation from recurrent circuits in visual cortex progressively increased to exceed direct thalamocortical excitation. Even when recurrent excitation exceeded thalamic excitation, upon silencing thalamus, sensory-evoked activity in cortex decayed rapidly, with a time constant of 10 ms, which is similar to a neuron's integration time window. In awake mice, this cortical decay function predicted the time-locking of cortical activity to thalamic input at frequencies <15 Hz and attenuation of the cortical response to higher frequencies. Under anesthesia, depression at thalamocortical synapses disrupted the fidelity of sensory transmission. Thus, we determine dynamics intrinsic to cortical recurrent circuits that transform afferent input in time.

  20. Predictive lymphatic mapping: a method for mapping lymphatic channels in patients with advanced unilateral lymphedema using indocyanine green lymphography.

    PubMed

    Mihara, Makoto; Seki, Yukio; Hara, Hisako; Iida, Takuya; Oka, Aiko; Kikuchi, Kazuki; Narushima, Mitsunaga; Haragi, Makiko; Furniss, Dominic; Hin-Lun, Lawrence; Mitsui, Kito; Murai, Noriyuki; Koshima, Isao

    2014-01-01

    In severe lymphedema, indocyanine green lymphography cannot be used to map lymphatic channels before lymphaticovenular anastomosis (LVA) because linear lymphatics cannot be detected in a severely affected leg. Here, we describe a new method, which we refer to as predictive lymphatic mapping, to predict the location of lymphatics for anastomosis in unilateral lymphedema, thereby improving surgical accuracy and efficiency. The approach consists of marking anatomical landmarks and joining selected landmarks with fixed lines. The distance from these fixed lines to lymphatic channels mapped by indocyanine green lymphography in the unaffected leg is then measured, scaled up based on the difference in circumference between the legs, and transposed to the affected leg. To date, we have used this method in 5 cases of unilateral or asymmetric lymphedema of the lower extremities. In no cases have we failed to find a lymphatic channel suitable for LVA within a 2-cm incision. These results suggest that predictive lymphatic mapping is a useful additional tool for surgeons performing LVA under local anesthesia, which will help to improve the accuracy of incisions and the efficiency of surgery.

  1. An investigation of the topography of the lymphatic system of the grey kangaroo (Macropus giganteus). 1. The superficial lymphatic system.

    PubMed Central

    Hopwood, P R

    1988-01-01

    The superficial lymphatic system of the grey kangaroo, Macropus giganteus is described. The description is based on dissections of 130 eastern grey kangaroos. The most significant difference found between the superficial lymphatic drainage pattern of kangaroos and that of the domestic species was the existence of large inguino-axillary lymphatic trunks in the kangaroo. Thus in the kangaroo, instead of lymph passing from the inguinal lymphocentre to the lumbar lymphatic trunks as is the situation in the domestic animals, lymph passes from the inguinal lymphocentre to the axillary lymphocentre. Apart from the lymph draining from the head and ventral neck (which passes to the superficial cervical lymphocentre) and lymph which may pass from the superficial lymphatic vessels to deeper lymphatic vessels, all the superficial lymphatic drainage of the kangaroo passes through the axillary lymphocentre. From the viewpoint of the meat inspection of the carcasses of kangaroos taken as game meat animals, pathology of the axillary lymphocentre may reflect disease in a much wider range of body regions than it would in a domestic animal. PMID:3198478

  2. Characterization of primary afferent spinal innervation of mouse uterus.

    PubMed

    Herweijer, Geraldine; Kyloh, Melinda; Beckett, Elizabeth A H; Dodds, Kelsi N; Spencer, Nick J

    2014-01-01

    The primary afferent innervation of the uterus is incompletely understood. The aim of this study was to identify the location and characteristics of primary afferent neurons that innervate the uterine horn of mice and correlate the different morphological types of putative primary afferent nerve endings, immunoreactive to the sensory marker, calcitonin gene related peptide (CGRP). Using retrograde tracing, injection of 5-10 μL of 1,1'-didodecyl-3,3,3,3'-tetramethylindocarbocyanine perchlorate (DiI) into discrete single sites in each uterine horn revealed a biomodal distribution of sensory neurons in dorsal root ganglia (DRG) with peak labeling occurring between T13-L3 and a second smaller peak between L6-S1. The mean cross sectional area of labeled cells was 463 μm(2) ± s.e.m. A significantly greater proportion of labeled neurons consisted of small cell bodies (<300 μm(2)) in the sacral spinal cord (S2) compared with peak labeling at the lumbar (L2) region. In both sections and whole mount preparations, immunohistochemical staining for CGRP revealed substantial innervation of the uterus by CGRP-positive nerve fibers located primarily at the border between the circular and longitudinal muscle layers (N = 4). The nerve endings were classified into three distinct types: "single," "branching," or "complex," that often aligned preferentially in either the circular or longitudinal axis of the smooth muscles. Complex endings were often associated with mesenteric vessels. We have identified that the cell bodies of primary afferent neurons innervating the mouse uterus lie primarily in DRG at L2 and S1 spinal levels. Also, the greatest density of CGRP immunoreactivity lies within the myometrium, with at least three different morphological types of nerve endings identified. These findings will facilitate further investigations into the mechanisms underlying sensory transduction in mouse uterus. PMID:25120416

  3. Coding of stimuli by ampullary afferents in Gnathonemus petersii.

    PubMed

    Engelmann, J; Gertz, S; Goulet, J; Schuh, A; von der Emde, G

    2010-10-01

    Weakly electric fish use electroreception for both active and passive electrolocation and for electrocommunication. While both active and passive electrolocation systems are prominent in weakly electric Mormyriform fishes, knowledge of their passive electrolocation ability is still scarce. To better estimate the contribution of passive electric sensing to the orientation toward electric stimuli in weakly electric fishes, we investigated frequency tuning applying classical input-output characterization and stimulus reconstruction methods to reveal the encoding capabilities of ampullary receptor afferents. Ampullary receptor afferents were most sensitive (threshold: 40 μV/cm) at low frequencies (<10 Hz) and appear to be tuned to a mix of amplitude and slope of the input signals. The low-frequency tuning was corroborated by behavioral experiments, but behavioral thresholds were one order of magnitude higher. The integration of simultaneously recorded afferents of similar frequency-tuning resulted in strongly enhanced signal-to-noise ratios and increased mutual information rates but did not increase the range of frequencies detectable by the system. Theoretically the neuronal integration of input from receptors experiencing opposite polarities of a stimulus (left and right side of the fish) was shown to enhance encoding of such stimuli, including an increase of bandwidth. Covariance and coherence analysis showed that spiking of ampullary afferents is sufficiently explained by the spike-triggered average, i.e., receptors respond to a single linear feature of the stimulus. Our data support the notion of a division of labor of the active and passive electrosensory systems in weakly electric fishes based on frequency tuning. Future experiments will address the role of central convergence of ampullary input that we expect to lead to higher sensitivity and encoding power of the system. PMID:20685928

  4. Neuropathic pain: Early spontaneous afferent activity is the trigger

    PubMed Central

    Xie, Wenrui; Strong, Judith A.; Meij, Johanna T.A.; Zhang, Jun-Ming; Yu, Lei

    2005-01-01

    Intractable neuropathic pain often results from nerve injury. One immediate event in damaged nerve is a sustained increase in spontaneous afferent activity, which has a well-established role in ongoing pain. Using two rat models of neuropathic pain, the CCI and SNI models, we show that local, temporary nerve blockade of this afferent activity permanently inhibits the subsequent development of both thermal hyperalgesia and mechanical allodynia. Timing is critical—the nerve blockade must last at least 3–5 days and is effective if started immediately after nerve injury, but not if started at 10 days after injury when neuropathic pain is already established. Effective nerve blockade also prevents subsequent development of spontaneous afferent activity measured electrophysiologically. Similar results were obtained in both pain models, and with two blockade methods (200 mg of a depot form bupivacaine at the injury site, or perfusion of the injured nerve just proximal to the injury site with TTX). These results indicate that early spontaneous afferent fiber activity is the key trigger for the development of pain behaviors, and suggest that spontaneous activity may be required for many of the later changes in the sensory neurons, spinal cord, and brain observed in neuropathic pain models. Many pre-clinical and clinical studies of pre-emptive analgesia have used much shorter duration of blockade, or have not started immediately after the injury. Our results suggest that effective pre-emptive analgesia can be achieved only when nerve block is administered early after injury and lasts several days. PMID:15964687

  5. Subcortical afferent connections of the amygdala in the monkey

    NASA Technical Reports Server (NTRS)

    Mehler, W. R.

    1980-01-01

    The cells of origin of the afferent connections of the amygdala in the rhesus and squirrel monkeys are determined according to the retrograde axonal transport of the enzyme horseradish peroxidase injected into various quadrants of the amygdala. Analysis of the distribution of enzyme-labeled cells reveals afferent amygdalar connections with the ipsilateral halves of the midline nucleus paraventricularis thalami and both the parvo- and magnocellular parts of the nucleus subparafascicularis in the dorsal thalamus, all the subdivisions of the midline nucleus centralis complex, the nucleus reuniens ventralis and the nucleus interventralis. The largest populations of enzyme-labeled cells in the hypothalamus are found to lie in the middle and posterior parts of the ipsilateral, lateral hypothalamus and the ventromedial hypothalamic nucleus, with scattered cells in the supramammillary and dorsomedial nuclei and the posterior hypothalamic area, Tsai's ventral tegmental area, the rostral and caudal subdivisions of the nucleus linearis in the midbrain and the dorsal raphe nucleus. The most conspicuous subdiencephalic source of amygdalar afferent connections is observed to be the pars lateralis of the nucleus parabrachialis in the dorsolateral pontine tegmentum, with a few labeled cells differentiated from pigmented cells in the locus coeruleus.

  6. Neck afferent involvement in cardiovascular control during movement

    NASA Technical Reports Server (NTRS)

    Bolton, P. S.; Ray, C. A.

    2000-01-01

    It is well established that labyrinth and neck afferent information contributes to the regulation of somatomotor function during movement and changes in posture. There is also convincing evidence that the vestibular system participates in the modulation of sympathetic outflow and cardiovascular function during changes in posture, presumably to prevent orthostatic hypotension. However, the labyrinth organs do not provide any signals concerning body movements with respect to the head. In contrast, the neck receptors, particularly muscle spindles, are well located and suited to provide information about changes in body position with respect to the head and vestibular signals. Studies in the cat suggest that neck afferent information may modulate the vestibulosympathetic reflex responses to head-neck movements. There is some evidence in the cat to suggest involvement of low threshold mechanoreceptors. However, human studies do not indicate that low threshold mechanoreceptors in the neck modulate cardiovascular responses. The human studies are consistent with the studies in the cat in that they demonstrate the importance of otolith activation in mediating cardiovascular and sympathetic responses to changes in posture. This paper briefly reviews the current experimental evidence concerning the involvement of neck afferent information in the modulation of cardiovascular control during movement and changes in posture.

  7. Transfer characteristics of the hair cell's afferent synapse

    NASA Astrophysics Data System (ADS)

    Keen, Erica C.; Hudspeth, A. J.

    2006-04-01

    The sense of hearing depends on fast, finely graded neurotransmission at the ribbon synapses connecting hair cells to afferent nerve fibers. The processing that occurs at this first chemical synapse in the auditory pathway determines the quality and extent of the information conveyed to the central nervous system. Knowledge of the synapse's input-output function is therefore essential for understanding how auditory stimuli are encoded. To investigate the transfer function at the hair cell's synapse, we developed a preparation of the bullfrog's amphibian papilla. In the portion of this receptor organ representing stimuli of 400-800 Hz, each afferent nerve fiber forms several synaptic terminals onto one to three hair cells. By performing simultaneous voltage-clamp recordings from presynaptic hair cells and postsynaptic afferent fibers, we established that the rate of evoked vesicle release, as determined from the average postsynaptic current, depends linearly on the amplitude of the presynaptic Ca2+ current. This result implies that, for receptor potentials in the physiological range, the hair cell's synapse transmits information with high fidelity. auditory system | exocytosis | glutamate | ribbon synapse | synaptic vesicle

  8. Putative roles of neuropeptides in vagal afferent signaling

    PubMed Central

    de Lartigue, Guillaume

    2014-01-01

    The vagus nerve is a major pathway by which information is communicated between the brain and peripheral organs. Sensory neurons of the vagus are located in the nodose ganglia. These vagal afferent neurons innervate the heart, the lung and the gastrointestinal tract, and convey information about peripheral signals to the brain important in the control of cardiovascular tone, respiratory tone, and satiation, respectively. Glutamate is thought to be the primary neurotransmitter involved in conveying all of this information to the brain. It remains unclear how a single neurotransmitter can regulate such an extensive list of physiological functions from a wide range of visceral sites. Many neurotransmitters have been identified in vagal afferent neurons and have been suggested to modulate the physiological functions of glutamate. Specifically, the anorectic peptide transmitters, cocaine and amphetamine regulated transcript (CART) and the orexigenic peptide transmitters, melanin concentrating hormone (MCH) are differentially regulated in vagal afferent neurons and have opposing effects on food intake. Using these two peptides as a model, this review will discuss the potential role of peptide transmitters in providing a more precise and refined modulatory control of the broad physiological functions of glutamate, especially in relation to the control of feeding. PMID:24650553

  9. Phylogeography of human lymphatic filarial parasite, Wuchereria bancrofti in India.

    PubMed

    Thangadurai, R; Hoti, S L; Kumar, N Pradeep; Das, P K

    2006-07-01

    Wuchereria bancrofti, a nematode parasite causing human lymphatic filariasis is widely distributed in India. The phylogeography of this parasite was studied by constructing RAPD profiles of parasite populations collected from 71 microfilaria carriers residing in different geoclimatic regions of India. The analysis showed that the phylogeography of W. bancrofti populations is complex, with a high genetic divergence and gene flow among populations. The total genetic diversity (H(T)) and genetic differentiation (G(ST)) estimated for all the parasite populations were 0.0926 and 0.5859, respectively. The gene flow (Nm) between different regions indicated that two strains of W. bancrofti were prevalent in the country, one in the eastern side and the other on the western side of the Western Ghats. A highly significant genetic differentiation (F(ST) [theta] = 0.7978) was estimated between these two strains (chi 2 = 308.2789; P < 0.001). The gene flow between these strains was very low (0.2338). These two strains appear to have drifted genetically because of their geographic isolation by this thickly forested mountain range. The strain in the eastern side was found to be monophyletic in origin and is undergoing genetic divergence as the major parasite population in the country, spanning from eastern peninsular region to the northern plains. The variable geoclimatic factors and the antifilarial chemotherapeutical pressure on the parasite, which is in place for the past half a century, might have contributed for the high genetic heterogeneity its strains/populations in the country. The route of entry of the parasite into Indian sub-continent possibly appeared to be from an ancient origin from the countries of the Southeast Asian archipelago, through the eastern coastal line of the southern peninsula.

  10. Anatomy and physiology of lymphatic drainage of the breast from the perspective of sentinel node biopsy.

    PubMed

    Tanis, P J; Nieweg, O E; Valdés Olmos, R A; Kroon, B B

    2001-03-01

    Knowledge of the anatomy and physiology of the lymphatic system is helpful when considering a particular sentinel node biopsy technique. The delicate balance between internal and external pressures in a lymphatic channel can be influenced by the injection volume and by massage in a negative or positive way. The narrow openings in the interendothelial junctions determine the speed of clearance of particles with a certain size, and this has implications for the timing of lymphoscintigraphy and surgery. Tracer uptake and lymph flow are highly variable and depend on a number of factors, some of which are beyond our control. The lymphatic anatomy is not completely understood despite numerous studies since the end of the 18th century. Several topics have been elucidated in more recent studies and through experience with sentinel node biopsy. First, although axillary drainage is the principal lymphatic path of the breast, any drainage pattern from any quadrant of the breast can occur. Second, most lymph from the breast flows to the nodal basins with a direct course, not passing through the subareolar plexus. Another relevant point is that gentle massage encourages lymph flow and facilitates sentinel node detection. What problems do we still face in clinical practice? The optimum size and number of labeled colloid particles remain to be established. The optimum volume of the tracer also remains to be determined. But the main controversy concerns the injection site. Although the intradermal injection technique has attractive practical features, there is currently insufficient certainty that drainage of tracer injected anywhere in or underneath the skin of the breast reflects drainage from the cancer. Connections between collecting lymphatic vessels from the tumor site and the collecting vessels from the skin and subdermal lymphatics can explain the concordance between intraparenchymal and superficial injections in most patients. To determine the technique that yields the

  11. Characterization of Mouse Lumbar Splanchnic and Pelvic Nerve Urinary Bladder Mechanosensory Afferents

    PubMed Central

    Xu, Linjing; Gebhart, G. F.

    2009-01-01

    Sensory information from the urinary bladder is conveyed via lumbar splanchnic (LSN) and sacral pelvic (PN) nerves to the spinal cord. In the present report we compared the mechanosensitive properties of single afferent fibers in these two pathways using an in vitro mouse bladder preparation. Mechanosensitive primary afferents were recorded from the LSN or PN and distinguished based on their response to receptive field stimulation with different mechanical stimuli: probing (160 mg to 2 g), stretch (1–25 g), and stroking of the urothelium (10–1,000 mg). Four different classes of afferent were recorded from the LSN and PN: serosal, muscular, muscular/urothielial, and urothelial. The LSN contained principally serosal and muscular afferents (97% of the total sample), whereas all four afferent classes of afferent were present in the PN (63% of which were muscular afferents). In addition, the respective proportions and receptive field distributions differed between the two pathways. Both low- and high-threshold stretch-sensitive muscular afferents were present in both pathways, and muscular afferents in the PN were shown to sensitize after exposure to an inflammatory soup cocktail. The LSN and PN pathways contain different populations of mechanosensitive afferents capable of detecting a range of mechanical stimuli and individually tuned to detect the type, magnitude, and duration of the stimulus. This knowledge broadens our understanding of the potential roles these two pathways play in conveying mechanical information from the bladder to the spinal cord. PMID:18003875

  12. Vestibular afferent responses to linear accelerations in the alert squirrel monkey

    NASA Technical Reports Server (NTRS)

    Somps, Christopher J.; Schor, Robert H.; Tomko, David L.

    1994-01-01

    The spontaneous activity of 40 otolith afferents and 44 canal afferents was recorded in 4 alert, intact squirrel monkeys. Polarization vectors and response properties of otolith afferents were determined during static re-orientations relative to gravity and during Earth-horizontal, sinusoidal, linear oscillations. Canal afferents were tested for sensitivity to linear accelerations. For regular otolith afferents, a significant correlation between upright discharge rate and sensitivity to dynamic acceleration in the horizontal plane was observed. This correlation was not present in irregular units. The sensitivity of otolith afferents to both static tilts and dynamic linear acceleration was much greater in irregularly discharging units than in regularly discharging units. The spontaneous activity and static and dynamic response properties of regularly discharging otolith afferents were similar to those reported in barbiturate-anesthetized squirrel monkeys. Irregular afferents also had similar dynamic response properties when compared to anesthetized monkeys. However, this sample of irregular afferents in alert animals had higher resting discharge rates and greater sensitivity to static tilts. The majority of otolith polarization vectors were oriented near the horizontal in the plane of the utricular maculae; however, directions of maximum sensitivity were different during dynamic and static testing. Canal afferents were not sensitive to static tilts or linear oscillations of the head.

  13. Intact cutaneous C fibre afferent properties in mechanical and cold neuropathic allodynia

    PubMed Central

    Hulse, Richard; Wynick, David; Donaldson, Lucy F.

    2010-01-01

    Patients with neuropathy, report changes in sensory perception, particularly mechanical and thermal allodynia, and spontaneous pain. Similar sensory changes are seen in experimental neuropathies, in which alteration in primary afferent properties can also be determined. The neural correlate of spontaneous pain is ongoing activity in sensory afferents. Mechanical and heat allodynia are thought to result from lowered activation thresholds in primary afferent and/or central neurones, but the mechanisms underlying cold allodynia are very poorly understood. We investigated nociceptive behaviours and the properties of C and A fibre intact afferents running adjacent to damaged afferents following a partial ligation injury of the saphenous nerve (PSNI). Animals developed mechanical and cold allodynia by 3 days after PSNI. Intact mechanosensitive C fibre afferents developed ongoing activity, and had slower conduction velocities 3 and 7 days following nerve injury, with no change in mechanical threshold. There was a large increase (∼46-fold) in calculated afferent input 3 days after nerve injury, as a result of the ongoing activity in these fibres. Mechano-cooling-sensitive C fibre afferents showed both enhanced cooling-evoked firing, and increased ongoing activity. The afferent barrage associated with mechano-cooling-sensitive afferents was increased 26-fold 7 days after nerve injury. We observed no differences in the properties of intact A fibre mechanosensitive afferents. These studies demonstrate for the first time that the altered nociception seen after PSNI is associated with ongoing activity and enhanced cooling-evoked activity in intact C fibre afferents in the saphenous nerve, with no concurrent alteration in A fibre afferents. PMID:19942464

  14. Roles of transcriptional network during the formation of lymphatic vessels.

    PubMed

    Watabe, Tetsuro

    2012-09-01

    The lymphatic vascular system, also known as the second vascular system in vertebrates, plays crucial roles in various physiological and pathological processes. It participates in the maintenance of normal tissue fluid balance, trafficking of the immune cells and absorption of fatty acids in the gut. Furthermore, lymphatic system is associated with the pathogenesis of a number of diseases, including lymphedema, inflammatory diseases and tumour metastasis. Lymphatic vessels are comprised of lymphatic endothelial cells (LECs), which are differentiated from blood vascular endothelial cells. This review highlights recent advances in our understanding of the transcriptional control of LEC fate determination and reflects on efforts to understand the roles of transcriptional networks during this discrete developmental process.

  15. Lymphatic dysfunction after ligation surgery for varicose vein

    PubMed Central

    Hara, Hisako; Mihara, Makoto; Hasegawa, Kyoko; Yamanaka, Kazuko

    2016-01-01

    Objective: Although the lymphatic complications such as lymphocele sometimes occur after surgery for varicose veins, the lymphatic function of such patients has not been evaluated. In this case report, we present a case of lymphocele after ligation surgery for varicose vein. We also detected subclinical dysfunction in lower limb using indocyanine green (ICG) lymphography. Case report: A 76 year- old female underwent ligation surgery for right lower leg varicose vein, and she noticed the squashy lesion in the medial side of the right knee. Three years later, she consulted our clinic and we performed ICG lymphography. We observed dermal backflow around the mass, which indicated lymphatic dysfunction. After injecting additional ICG around the knee, we punctured and drained the clear, yellow fluid from the mass and it was contrasted with ICG during the examination and the involvement of the lymphatic system was proven. PMID:27757234

  16. [Scintigraphic study of the lymphatic drainage of the anterior chamber of the mouse eye and its pathophysiological implications].

    PubMed

    Guignier, B; Bourahla, K; Bekaert, V; Brasse, D; Gaucher, D; Speeg-Schatz, C; Bourcier, T

    2013-12-01

    For many years, the intraocular lymphatic system and particularly the drainage of the aqueous humor by this system have been considered non-existant. Our study is the first to demonstrate, in a dynamic in vivo fashion, the existence of lymphatic drainage in the mouse eye. This has become possible with lymphoscintigraphy with nano-molecules of rhenium sulphide, marked by technetium-99m and injected into the anterior chamber of the mouse eye. Readings were taken using an experimental gamma camera specially built for the small animal. The hypothesis of a "uveolymphatic" drainage pathway within the ciliary body, contributing to aqueous outflow, has recently been highlighted by new improvements in microbiology (discovery of lymphatic endothelial-specific markers) and imaging. This new pathway may lead to many prospects: the development of techniques for visualization and quantification of this in vivo lymphatic flow may help to increase our understanding of the physiopathology and perhaps treatment of chronic glaucoma as well as neoplastic conditions. PMID:24099697

  17. An Immunological Fingerprint Differentiates Muscular Lymphatics from Arteries and Veins

    PubMed Central

    Bridenbaugh, Eric A.; Wang, Wei; Srimushnam, Maya; Cromer, Walter E.; Zawieja, Scott D.; Schmidt, Susan E.; Jupiter, Daniel C.; Huang, Hung-Chung; Van Buren, Vincent

    2013-01-01

    Abstract The principal function of the lymphatic system is to transport lymph from the interstitium to the nodes and then from the nodes to the blood. In doing so lymphatics play important roles in fluid homeostasis, macromolecular/antigen transport and immune cell trafficking. To better understand the genes that contribute to their unique physiology, we compared the transcriptional profile of muscular lymphatics (prenodal mesenteric microlymphatics and large, postnodal thoracic duct) to axillary and mesenteric arteries and veins isolated from rats. Clustering of the differentially expressed genes demonstrated that the lymph versus blood vessel differences were more profound than between blood vessels, particularly the microvessels. Gene ontology functional category analysis indicated that microlymphatics were enriched in antigen processing/presentation, IgE receptor signaling, catabolic processes, translation and ribosome; while they were diminished in oxygen transport, regulation of cell proliferation, glycolysis and inhibition of adenylate cyclase activity by G-proteins. We evaluated the differentially expressed microarray genes/products by qPCR and/or immunofluorescence. Immunofluorescence documented that multiple MHC class II antigen presentation proteins were highly expressed by an antigen-presenting cell (APC) type found resident within the lymphatic wall. These APCs also expressed CD86, a co-stimulatory protein necessary for T-cell activation. We evaluated the distribution and phenotype of APCs within the pre and postnodal lymphatic network. This study documents a novel population of APCs resident within the walls of muscular, prenodal lymphatics that indicates novel roles in antigen sampling and immune responses. In conclusion, these prenodal lymphatics exhibit a unique profile that distinguishes them from blood vessels and highlights the role of the lymphatic system as an immunovascular system linking the parenchymal interstitium, lymph nodes and the

  18. Current and Future Lymphatic Imaging Modalities for Tumor Staging

    PubMed Central

    Gao, Kuo; Liu, Tiegang; Tariq, Imran; Sajjad, Ashif; Niu, Meiying; Liu, Guokai; Mehmood, Zahid; Tian, Guihua

    2014-01-01

    Tumor progression is supported by the lymphatic system which should be scanned efficiently for tumor staging as well as the enhanced therapeutic outcomes. Poor resolution and low sensitivity is a limitation of traditional lymphatic imaging modalities; thus new noninvasive approaches like nanocarriers, magnetic resonance imaging, positron-emission tomography, and quantum dots are advantageous. Some newer modalities, which are under development, and their potential uses will also be discussed in this review. PMID:24757671

  19. Morphological and Molecular Characterization of Human Dermal Lymphatic Collectors

    PubMed Central

    Buttler, Kerstin; Ströbel, Philipp; Becker, Jürgen; Aung, Thiha; Felmerer, Gunther; Wilting, Jörg

    2016-01-01

    Millions of patients suffer from lymphedema worldwide. Supporting the contractility of lymphatic collectors is an attractive target for pharmacological therapy of lymphedema. However, lymphatics have mostly been studied in animals, while the cellular and molecular characteristics of human lymphatic collectors are largely unknown. We studied epifascial lymphatic collectors of the thigh, which were isolated for autologous transplantations. Our immunohistological studies identify additional markers for LECs (vimentin, CCBE1). We show and confirm differences between initial and collecting lymphatics concerning the markers ESAM1, D2-40 and LYVE-1. Our transmission electron microscopic studies reveal two types of smooth muscle cells (SMCs) in the media of the collectors with dark and light cytoplasm. We observed vasa vasorum in the media of the largest collectors, as well as interstitial Cajal-like cells, which are highly ramified cells with long processes, caveolae, and lacking a basal lamina. They are in close contact with SMCs, which possess multiple caveolae at the contact sites. Immunohistologically we identified such cells with antibodies against vimentin and PDGFRα, but not CD34 and cKIT. With Next Generation Sequencing we searched for highly expressed genes in the media of lymphatic collectors, and found therapeutic targets, suitable for acceleration of lymphatic contractility, such as neuropeptide Y receptors 1, and 5; tachykinin receptors 1, and 2; purinergic receptors P2RX1, and 6, P2RY12, 13, and 14; 5-hydroxytryptamine receptors HTR2B, and 3C; and adrenoceptors α2A,B,C. Our studies represent the first comprehensive characterization of human epifascial lymphatic collectors, as a prerequisite for diagnosis and therapy. PMID:27764183

  20. Sensitivity analysis of near-infrared functional lymphatic imaging

    NASA Astrophysics Data System (ADS)

    Weiler, Michael; Kassis, Timothy; Dixon, J. Brandon

    2012-03-01

    Background - Near-infrared (NIR) imaging of lymphatic drainage of injected indocyanine green (ICG) has emerged as a new technology for clinical imaging of lymphatic architecture and quantification of vessel function, offering better spatial and temporal resolution than competing imaging modalities. While NIR lymphatic imaging has begun to be reported in the literature, the technology is still in its infancy and its imaging capabilities have yet to be quantitatively characterized. The objective of this study, therefore, was to characterize the parameters of NIR lymphatic imaging to quantify its capabilities as a diagnostic tool for evaluating lymphatic disease. Methods - An NIR imaging system was developed using a laser diode for excitation, ICG as a fluorescent agent, and a CCD camera to detect emission. A tissue phantom with mock lymphatic vessels of known depths and diameters was used as an alternative to in vivo lymphatic vessels due to the greater degree of control with the phantom. Results and Conclusions - When dissolved in an albumin physiological salt solution (APSS) to mimic interstitial fluid, ICG experiences shifts in the excitation/emission wavelengths such that it is maximally excited at 805nm and produces peak fluorescence at 840nm. Premixing ICG with albumin induces greater fluorescence intensity, with the ideal concentration being: 900μM (60g/L) albumin and 193.5μM (150μg/mL) ICG. ICG fluorescence can be detected as deep as 6mm, but spatial resolution deteriorates severely below 3mm, thus skewing vessel geometry measurements. ICG packet travel, a common measure of lymphatic transport, can be detected as deep as 5mm.

  1. Quantum dots trace lymphatic drainage from the mouse eye

    NASA Astrophysics Data System (ADS)

    Tam, Alex L. C.; Gupta, Neeru; Zhang, Zhexue; Yücel, Yeni H.

    2011-10-01

    Glaucoma is a leading cause of blindness in the world, often associated with elevated eye pressure. Currently, all glaucoma treatments aim to lower eye pressure by improving fluid exit from the eye. We recently reported the presence of lymphatics in the human eye. The lymphatic circulation is known to drain fluid from organ tissues and, as such, lymphatics may also play a role in draining fluid from the eye. We investigated whether lymphatic drainage from the eye is present in mice by visualizing the trajectory of quantum dots once injected into the eye. Whole-body hyperspectral fluorescence imaging was performed in 17 live mice. In vivo imaging was conducted prior to injection, and 5, 20, 40 and 70 min, and 2, 6 and 24 h after injection. A quantum dot signal was observed in the left neck region at 6 h after tracer injection into the eye. Examination of immunofluorescence-labelled sections using confocal microscopy showed the presence of a quantum dot signal in the left submandibular lymph node. This is the first direct evidence of lymphatic drainage from the mouse eye. The use of quantum dots to image this lymphatic pathway in vivo is a novel tool to stimulate new treatments to reduce eye pressure and prevent blindness from glaucoma.

  2. The association of adult Onchocerca volvulus with lymphatic vessels.

    PubMed

    Mackenzie, C D; Huntington, M K; Wanji, S; Lovato, R V; Eversole, R R; Geary, T G

    2010-02-01

    Immunocytochemical examination of onchocercal nodule tissues containing adult Onchocerca volvulus using immuno-markers for blood and lymphatic vessels (vWF, D2-40, podoplanin, Prox-1, and Lyve1) shows a distinct pattern of distribution of these vessels within nodules. Blood vessels were commonly seen associated with organized lymphoid cellular aggregates in the both the outer and inner areas of the nodules. In contrast, the majority of the lymphatic vessel positivity was seen in the central zone in close apposition to the adult parasites, and the remainder usually associated with microfilariae in the outer areas of the nodule. These findings suggest an intimate relationship between adult O. volvulus and lymphatic vessels, including the likely proliferation of lymphatic endothelial cells (lymphangectasia) akin to that seen with other filariae. These findings indicate that adult O. volvulus may migrate via the lymphatic system, and that clinical manifestations of this disease that involve tissue edema may be the result of the location of these worms in the lymphatic system.

  3. Sensitivity analysis of near-infrared functional lymphatic imaging

    NASA Astrophysics Data System (ADS)

    Weiler, Michael; Kassis, Timothy; Dixon, J. Brandon

    2012-06-01

    Near-infrared imaging of lymphatic drainage of injected indocyanine green (ICG) has emerged as a new technology for clinical imaging of lymphatic architecture and quantification of vessel function, yet the imaging capabilities of this approach have yet to be quantitatively characterized. We seek to quantify its capabilities as a diagnostic tool for lymphatic disease. Imaging is performed in a tissue phantom for sensitivity analysis and in hairless rats for in vivo testing. To demonstrate the efficacy of this imaging approach to quantifying immediate functional changes in lymphatics, we investigate the effects of a topically applied nitric oxide (NO) donor glyceryl trinitrate ointment. Premixing ICG with albumin induces greater fluorescence intensity, with the ideal concentration being 150 μg/mL ICG and 60 g/L albumin. ICG fluorescence can be detected at a concentration of 150 μg/mL as deep as 6 mm with our system, but spatial resolution deteriorates below 3 mm, skewing measurements of vessel geometry. NO treatment slows lymphatic transport, which is reflected in increased transport time, reduced packet frequency, reduced packet velocity, and reduced effective contraction length. NIR imaging may be an alternative to invasive procedures measuring lymphatic function in vivo in real time.

  4. The surgical anatomy of the lymphatic system of the pancreas.

    PubMed

    Cesmebasi, Alper; Malefant, Jason; Patel, Swetal D; Du Plessis, Maira; Renna, Sarah; Tubbs, R Shane; Loukas, Marios

    2015-05-01

    The lymphatic system of the pancreas is a complex, intricate network of lymphatic vessels and nodes responsible for the drainage of the head, neck, body, and tail of the pancreas. Its anatomical divisions and embryological development have been well described in the literature with emphasis on its clinical relevance in regards to pancreatic pathologies. A thorough knowledge and understanding of the lymphatic system surrounding the pancreas is critical for physicians in providing diagnostic and treatment strategies for patients with pancreatic cancer and pancreatitis. Pancreatic cancer has an extremely poor prognosis and is a notable cause of morbidity and mortality worldwide. Although a surgeon may try to predict the routes for metastasis for pancreatic cancer, the complexity of this system presents difficulty due to variable drainage patterns. Pancreatitis also presents as another severe disease which has been shown to have an association with the lymphatics. The aim of this article is to review the literature on the lymphatics of the pancreas, pancreatic pathologies, and the available imaging methodologies used to study the pancreatic lymphatics.

  5. Lymphatic function is required prenatally for lung inflation at birth

    PubMed Central

    Jakus, Zoltán; Gleghorn, Jason P.; Enis, David R.; Sen, Aslihan; Chia, Stephanie; Liu, Xi; Rawnsley, David R.; Yang, Yiqing; Hess, Paul R.; Zou, Zhiying; Yang, Jisheng; Guttentag, Susan H.; Nelson, Celeste M.

    2014-01-01

    Mammals must inflate their lungs and breathe within minutes of birth to survive. A key regulator of neonatal lung inflation is pulmonary surfactant, a lipoprotein complex which increases lung compliance by reducing alveolar surface tension (Morgan, 1971). Whether other developmental processes also alter lung mechanics in preparation for birth is unknown. We identify prenatal lymphatic function as an unexpected requirement for neonatal lung inflation and respiration. Mice lacking lymphatic vessels, due either to loss of the lymphangiogenic factor CCBE1 or VEGFR3 function, appear cyanotic and die shortly after birth due to failure of lung inflation. Failure of lung inflation is not due to reduced surfactant levels or altered development of the lung but is associated with an elevated wet/dry ratio consistent with edema. Embryonic studies reveal active lymphatic function in the late gestation lung, and significantly reduced total lung compliance in late gestation embryos that lack lymphatics. These findings reveal that lymphatic vascular function plays a previously unrecognized mechanical role in the developing lung that prepares it for inflation at birth. They explain respiratory failure in infants with congenital pulmonary lymphangiectasia, and suggest that inadequate late gestation lymphatic function may also contribute to respiratory failure in premature infants. PMID:24733830

  6. Lymphatics at the crossroads of angiogenesis and lymphangiogenesis

    PubMed Central

    Scavelli, Claudio; Weber, Elisabetta; Aglianò, Margherita; Cirulli, Teresa; Nico, Beatrice; Vacca, Angelo; Ribatti, Domenico

    2004-01-01

    The lymphatic system is implicated in interstitial fluid balance regulation, immune cell trafficking, oedema and cancer metastasis. However, the sequence of events that initiate and coordinate lymphatic vessel development (lymphangiogenesis) remains obscure. In effect, the understanding of physiological regulation of lymphatic vasculature has been overshadowed by the greater emphasis focused on angiogenesis, and delayed by a lack of specific markers, thereby limiting this field to no more than a descriptive characterization. Recently, new insights into lymphangiogenesis research have been due to the discovery of lymphatic-specific markers and growth factors of vascular endothelial growth factor (VEGF) family, such as VEGF-C and VEGF-D. Studies using transgenic mice overexpressing VEGF-C and VEGF-D have demonstrated a crucial role for these factors in tumour lymphangiogenesis. Knowledge of lymphatic development has now been redefined at the molecular level, providing an interesting target for innovative therapies. This review highlights the recent insights and advances into the field of lymphatic vascular research, outlining the most important aspects of the embryo development, structure, specific markers and methods applied for studying lymphangiogenesis. Finally, molecular mechanisms involved in the regulation of lymphangiogenesis are described. PMID:15198686

  7. Mechanotransduction activates canonical Wnt/β-catenin signaling to promote lymphatic vascular patterning and the development of lymphatic and lymphovenous valves.

    PubMed

    Cha, Boksik; Geng, Xin; Mahamud, Md Riaj; Fu, Jianxin; Mukherjee, Anish; Kim, Yeunhee; Jho, Eek-Hoon; Kim, Tae Hoon; Kahn, Mark L; Xia, Lijun; Dixon, J Brandon; Chen, Hong; Srinivasan, R Sathish

    2016-06-15

    Lymphatic vasculature regulates fluid homeostasis by returning interstitial fluid to blood circulation. Lymphatic endothelial cells (LECs) are the building blocks of the entire lymphatic vasculature. LECs originate as a homogeneous population of cells predominantly from the embryonic veins and undergo stepwise morphogenesis to become the lymphatic capillaries, collecting vessels or valves. The molecular mechanisms underlying the morphogenesis of the lymphatic vasculature remain to be fully understood. Here we show that canonical Wnt/β-catenin signaling is necessary for lymphatic vascular morphogenesis. Lymphatic vascular-specific ablation of β-catenin in mice prevents the formation of lymphatic and lymphovenous valves. Additionally, lymphatic vessel patterning is defective in these mice, with abnormal recruitment of mural cells. We found that oscillatory shear stress (OSS), which promotes lymphatic vessel maturation, triggers Wnt/β-catenin signaling in LECs. In turn, Wnt/β-catenin signaling controls the expression of several molecules, including the lymphedema-associated transcription factor FOXC2. Importantly, FOXC2 completely rescues the lymphatic vessel patterning defects in mice lacking β-catenin. Thus, our work reveals that mechanical stimulation is a critical regulator of lymphatic vascular development via activation of Wnt/β-catenin signaling and, in turn, FOXC2.

  8. Mechanotransduction activates canonical Wnt/β-catenin signaling to promote lymphatic vascular patterning and the development of lymphatic and lymphovenous valves

    PubMed Central

    Cha, Boksik; Geng, Xin; Mahamud, Md. Riaj; Fu, Jianxin; Mukherjee, Anish; Kim, Yeunhee; Jho, Eek-hoon; Kim, Tae Hoon; Kahn, Mark L.; Xia, Lijun; Dixon, J. Brandon; Chen, Hong; Srinivasan, R. Sathish

    2016-01-01

    Lymphatic vasculature regulates fluid homeostasis by returning interstitial fluid to blood circulation. Lymphatic endothelial cells (LECs) are the building blocks of the entire lymphatic vasculature. LECs originate as a homogeneous population of cells predominantly from the embryonic veins and undergo stepwise morphogenesis to become the lymphatic capillaries, collecting vessels or valves. The molecular mechanisms underlying the morphogenesis of the lymphatic vasculature remain to be fully understood. Here we show that canonical Wnt/β-catenin signaling is necessary for lymphatic vascular morphogenesis. Lymphatic vascular-specific ablation of β-catenin in mice prevents the formation of lymphatic and lymphovenous valves. Additionally, lymphatic vessel patterning is defective in these mice, with abnormal recruitment of mural cells. We found that oscillatory shear stress (OSS), which promotes lymphatic vessel maturation, triggers Wnt/β-catenin signaling in LECs. In turn, Wnt/β-catenin signaling controls the expression of several molecules, including the lymphedema-associated transcription factor FOXC2. Importantly, FOXC2 completely rescues the lymphatic vessel patterning defects in mice lacking β-catenin. Thus, our work reveals that mechanical stimulation is a critical regulator of lymphatic vascular development via activation of Wnt/β-catenin signaling and, in turn, FOXC2. PMID:27313318

  9. Localization and proliferation of lymphatic vessels in the tympanic membrane in normal state and regeneration

    SciTech Connect

    Miyashita, Takenori; Burford, James L.; Hong, Young-Kwon; Gevorgyan, Haykanush; Lam, Lisa; Mori, Nozomu; Peti-Peterdi, Janos

    2013-10-25

    Highlights: •We newly developed the whole-mount imaging method of the tympanic membrane. •Lymphatic vessel loops were localized around the malleus handle and annulus tympanicus. •In regeneration, abundant lymphatic vessels were observed in the pars tensa. •Site-specific lymphatic vessels may play an important role in the tympanic membrane. -- Abstract: We clarified the localization of lymphatic vessels in the tympanic membrane and proliferation of lymphatic vessels during regeneration after perforation of the tympanic membrane by using whole-mount imaging of the tympanic membrane of Prox1 GFP mice. In the pars tensa, lymphatic vessel loops surrounded the malleus handle and annulus tympanicus. Apart from these locations, lymphatic vessel loops were not observed in the pars tensa in the normal tympanic membrane. Lymphatic vessel loops surrounding the malleus handle were connected to the lymphatic vessel loops in the pars flaccida and around the tensor tympani muscle. Many lymphatic vessel loops were detected in the pars flaccida. After perforation of the tympanic membrane, abundant lymphatic regeneration was observed in the pars tensa, and these regenerated lymphatic vessels extended from the lymphatic vessels surrounding the malleus at day 7. These results suggest that site-specific lymphatic vessels play an important role in the tympanic membrane.

  10. Role of the paraventricular nucleus in the reflex diuresis to pulmonary lymphatic obstruction in rabbits.

    PubMed

    Choudhary, Rishabh Charan; Sharma, Ravindra Kumar; Gulati, Kavita; Ravi, Krishnan

    2016-01-01

    The changes in urine flow and renal sympathetic nerve activity (RSNA) due to pulmonary lymphatic obstruction (PLO) were examined in anesthetized, artificially ventilated New Zealand white rabbits. PLO was produced by pressurizing an isolated pouch created in the right external jugular vein at the points of entry of the right lymphatic ducts. During this maneuver, urine flow increased from 8.5 ± 0.3 mL/10 min to 12 ± 0.5 mL/10 min (P < 0.0001) and RSNA increased from 24.0 ± 4 to 40.0 ± 5 μV·s (P < 0.0001). Bilateral lesioning of the paraventricular nucleus (PVN) of the hypothalamus or cervical vagotomy abolished these responses. PLO increased c-fos gene expression in the PVN. The increase in urine flow due to PLO was attenuated by muscimol and abolished by kynurenic acid microinjections into the PVN. The results show that (i) neurons in the PVN are an important relay site in the reflex arc, which is activated by PLO; and (ii) this activation is regulated by glutamatergic and partly by GABAergic input to the PVN.

  11. Differential roles of stretch-sensitive pelvic nerve afferents innervating mouse distal colon and rectum

    PubMed Central

    Brumovsky, Pablo R.; Gebhart, Gerald F.

    2010-01-01

    Information about colorectal distension (i.e., colorectal dilation by increased intraluminal pressure) is primarily encoded by stretch-sensitive colorectal afferents in the pelvic nerve (PN). Despite anatomic differences between rectum and distal colon, little is known about the functional roles of colonic vs. rectal afferents in the PN pathway or the quantitative nature of mechanosensory encoding. We utilized an in vitro mouse colorectum-PN preparation to investigate pressure-encoding characteristics of colorectal afferents. The colorectum with PN attached was dissected, opened longitudinally, and pinned flat in a Sylgard-lined chamber. Action potentials of afferent fibers evoked by circumferential stretch (servo-controlled force actuator) were recorded from the PN. Stretch-sensitive fibers were categorized into the following four groups: colonic muscular, colonic muscular/mucosal, rectal muscular, and rectal muscular/mucosal. Seventy-nine stretch-sensitive PN afferents evenly distributed into the above four groups were studied. Rectal muscular afferents had significantly greater stretch-responses than the other three groups. Virtually all rectal afferents (98%) had low thresholds for response and encoded stimulus intensity into the noxious range without obvious saturation. Most colonic afferents (72%) also had low thresholds (<14 mmHg), but a significant proportion (28%) had high thresholds (>18 mmHg) for response. These high-threshold colonic afferents were sensitized to stretch by inflammatory soup; response threshold was significantly reduced (from 23 to 12 mmHg), and response magnitude significantly increased. These results suggest that the encoding of mechanosensory information differs between colonic and rectal stretch-sensitive PN afferents. Rectal afferents have a wide response range to stretch, whereas high-threshold colonic afferents likely contribute to visceral nociception. PMID:20075141

  12. Effects of intratympanic gentamicin on vestibular afferents and hair cells in the chinchilla.

    PubMed

    Hirvonen, Timo P; Minor, Lloyd B; Hullar, Timothy E; Carey, John P

    2005-02-01

    Gentamicin is toxic to vestibular hair cells, but its effects on vestibular afferents have not been defined. We treated anesthetized chinchillas with one injection of gentamicin (26.7 mg/ml) into the middle ear and made extracellular recordings from afferents after 5-25 (early) or 90-115 days (late). The relative proportions of regular, intermediate, and irregular afferents did not change after treatment. The spontaneous firing rate of regular afferents was lower (P < 0.001) on the treated side (early: 44.3 +/- 16.3; late: 33.9 +/- 13.2 spikes x s(-1)) than on the untreated side (54.9 +/- 16.8 spikes x s(-1)). Spontaneous rates of irregular and intermediate afferents did not change. The majority of treated afferents did not measurably respond to tilt or rotation (82% in the early group, 76% in the late group). Those that did respond had abnormally low sensitivities (P < 0.001). Treated canal units that responded to rotation had mean sensitivities only 5-7% of the values for untreated canal afferents. Treated otolith afferents had mean sensitivities 23-28% of the values for untreated otolith units. Sensitivity to externally applied galvanic currents was unaffected for all afferents. Intratympanic gentamicin treatment reduced the histological density of all hair cells by 57% (P = 0.04). The density of hair cells with calyx endings was reduced by 99% (P = 0.03), although some remaining hair cells had other features suggestive of type I morphology. Type II hair cell density was not significantly reduced. These findings suggest that a single intratympanic gentamicin injection causes partial damage and loss of vestibular hair cells, particularly type I hair cells or their calyceal afferent endings, does not damage the afferent spike initiation zones, and preserves enough hair cell synaptic activity to drive the spontaneous activity of vestibular afferents.

  13. Differential roles of stretch-sensitive pelvic nerve afferents innervating mouse distal colon and rectum.

    PubMed

    Feng, Bin; Brumovsky, Pablo R; Gebhart, Gerald F

    2010-03-01

    Information about colorectal distension (i.e., colorectal dilation by increased intraluminal pressure) is primarily encoded by stretch-sensitive colorectal afferents in the pelvic nerve (PN). Despite anatomic differences between rectum and distal colon, little is known about the functional roles of colonic vs. rectal afferents in the PN pathway or the quantitative nature of mechanosensory encoding. We utilized an in vitro mouse colorectum-PN preparation to investigate pressure-encoding characteristics of colorectal afferents. The colorectum with PN attached was dissected, opened longitudinally, and pinned flat in a Sylgard-lined chamber. Action potentials of afferent fibers evoked by circumferential stretch (servo-controlled force actuator) were recorded from the PN. Stretch-sensitive fibers were categorized into the following four groups: colonic muscular, colonic muscular/mucosal, rectal muscular, and rectal muscular/mucosal. Seventy-nine stretch-sensitive PN afferents evenly distributed into the above four groups were studied. Rectal muscular afferents had significantly greater stretch-responses than the other three groups. Virtually all rectal afferents (98%) had low thresholds for response and encoded stimulus intensity into the noxious range without obvious saturation. Most colonic afferents (72%) also had low thresholds (<14 mmHg), but a significant proportion (28%) had high thresholds (>18 mmHg) for response. These high-threshold colonic afferents were sensitized to stretch by inflammatory soup; response threshold was significantly reduced (from 23 to 12 mmHg), and response magnitude significantly increased. These results suggest that the encoding of mechanosensory information differs between colonic and rectal stretch-sensitive PN afferents. Rectal afferents have a wide response range to stretch, whereas high-threshold colonic afferents likely contribute to visceral nociception.

  14. Lymphatic filariasis: Treatment, control and elimination.

    PubMed

    Ottesen, Eric A

    2006-01-01

    Lymphatic filariasis (LF) is a disease not just treatable or controllable; it is a disease that can be eliminated. Indeed, LF is currently the target of a major global initiative to do just that; a few visionaries of the past 50 years did hypothesize that LF elimination was feasible. However, for most of the scientific and global health communities, the elimination of such a broadly disseminated, mosquito-borne disease has seemed highly unlikely. During the past decade, however, both the treatment strategies and the control strategies for LF have undergone profound paradigm shifts-all because of a rapid increase in knowledge and understanding of LF that derived directly from a series of remarkable achievements by the scientific and medical research communities. As a result, a public health dimension with a focus on affected populations, now supplements the earlier, predominantly patient-oriented clinical approach to LF. The early uncertainties, then the essential steps leading to this change in outlook are outlined below, followed by descriptions of the new strategy for LF elimination, the Global Programme created to attain this goal and the successes achieved to date.

  15. Long-term sensitization of mechanosensitive and -insensitive afferents in mice with persistent colorectal hypersensitivity

    PubMed Central

    La, Jun-ho; Schwartz, Erica S.; Tanaka, Takahiro; McMurray, Timothy P.; Gebhart, G. F.

    2012-01-01

    Afferent input contributes significantly to the pain and colorectal hypersensitivity that characterize irritable bowel syndrome. In the present study, we investigated the contributions of mechanically sensitive and mechanically insensitive afferents (MIAs; or silent afferents) to colorectal hypersensitivity. The visceromotor response to colorectal distension (CRD; 15–60 mmHg) was recorded in mice before and for weeks after intracolonic treatment with zymosan or saline. After CRD tests, the distal colorectum with the pelvic nerve attached was removed for single-fiber electrophysiological recordings. Colorectal afferent endings were located by electrical stimulation and characterized as mechanosensitive or not by blunt probing, mucosal stroking, and circumferential stretch. Intracolonic zymosan produced persistent colorectal hypersensitivity (>24 days) associated with brief colorectal inflammation. Pelvic nerve muscular-mucosal but not muscular mechanosensitive afferents recorded from mice with colorectal hypersensitivity exhibited persistent sensitization. In addition, the proportion of MIAs (relative to control) was significantly reduced from 27% to 13%, whereas the proportion of serosal afferents was significantly increased from 34% to 53%, suggesting that MIAs acquired mechanosensitivity. PGP9.5 immunostaining revealed no significant loss of colorectal nerve fiber density, suggesting that the reduction in MIAs is not due to peripheral fiber loss after intracolonic zymosan. These results indicate that colorectal MIAs and sensitized muscular-mucosal afferents that respond to stretch contribute significantly to the afferent input that sustains hypersensitivity to CRD, suggesting that targeted management of colorectal afferent input could significantly reduce patients' complaints of pain and hypersensitivity. PMID:22268098

  16. Meningeal afferent signaling and the pathophysiology of migraine.

    PubMed

    Burgos-Vega, Carolina; Moy, Jamie; Dussor, Gregory

    2015-01-01

    Migraine is the most common neurological disorder. Attacks are complex and consist of multiple phases but are most commonly characterized by intense, unilateral, throbbing headache. The pathophysiology contributing to migraine is poorly understood and the disorder is not well managed with currently available therapeutics, often rendering patients disabled during attacks. The mechanisms most likely to contribute to the pain phase of migraine require activation of trigeminal afferent signaling from the cranial meninges and subsequent relay of nociceptive information into the central nervous system in a region of the dorsal brainstem known as the trigeminal nucleus caudalis. Events leading to activation of meningeal afferents are unclear, but nerve endings within this tissue are mechanosensitive and also express a variety of ion channels including acid-sensing ion channels and transient receptor-potential channels. These properties may provide clues into the pathophysiology of migraine by suggesting that decreased extracellular pH and environmental irritant exposure in the meninges contributes to headache. Neuroplasticity is also likely to play a role in migraine given that attacks are triggered by routine events that are typically nonnoxious in healthy patients and clear evidence of sensitization occurs during an attack. Where and how plasticity develops is also not clear but may include events directly on the afferents and/or within the TNC. Among the mediators potentially contributing to plasticity, calcitonin gene-related peptide has received the most attention within the migraine field but other mechanisms may also contribute. Ultimately, greater understanding of the molecules and mechanisms contributing to migraine will undoubtedly lead to better therapeutics and relief for the large number of patients across the globe who suffer from this highly disabling neurological disorder.

  17. Mechano- and thermosensitivity of regenerating cutaneous afferent nerve fibers.

    PubMed

    Jänig, Wilfrid; Grossmann, Lydia; Gorodetskaya, Natalia

    2009-06-01

    Crush lesion of a skin nerve is followed by sprouting of myelinated (A) and unmyelinated (C) afferent fibers into the distal nerve stump. Here, we investigate quantitatively both ongoing activity and activity evoked by mechanical or thermal stimulation of the nerve in 43 A- and 135 C-fibers after crush lesion of the sural nerve using neurophysiological recordings in anesthetized rats. The discharge patterns in the injured afferent nerve fibers and in intact (control) afferent nerve fibers were compared. (1) Almost all (98%) A-fibers were mechanosensitive, some of them exhibited additionally weak cold/heat sensitivity; 7% had ongoing activity. (2) Three patterns of physiologically evoked activity were present in the lesioned C-fibers: (a) C-fibers with type 1 cold sensitivity (low cold threshold, inhibition on heating, high level of ongoing and cold-evoked activity; 23%): almost all of them were mechanoinsensitive and 40% of them were additionally heat-sensitive; (b) C-fibers with type 2 cold sensitivity (high cold threshold, low level of ongoing and cold-evoked activity; 23%). All of them were excited by mechanical and/or heat stimuli; (c) cold-insensitive C-fibers (54%), which were heat- and/or mechanosensitive. (3) The proportions of C-fibers exhibiting these three patterns of discharge to physiological stimuli were almost identical in the population of injured C-fibers and in a population of 91 intact cutaneous C-fibers. 4. Ongoing activity was present in 56% of the lesioned C-fibers. Incidence and rate of ongoing activity were the same in the populations of lesioned and intact type 1 cold-sensitive C-fibers. The incidence (but not rate) of ongoing activity was significantly higher in lesioned type 2 cold-sensitive and cold insensitive C-fibers than in the corresponding populations of intact C-fibers (42/93 fibers vs. 11/72 fibers). PMID:19139872

  18. Kv1 channels and neural processing in vestibular calyx afferents.

    PubMed

    Meredith, Frances L; Kirk, Matthew E; Rennie, Katherine J

    2015-01-01

    Potassium-selective ion channels are important for accurate transmission of signals from auditory and vestibular sensory end organs to their targets in the central nervous system. During different gravity conditions, astronauts experience altered input signals from the peripheral vestibular system resulting in sensorimotor dysfunction. Adaptation to altered sensory input occurs, but it is not explicitly known whether this involves synaptic modifications within the vestibular epithelia. Future investigations of such potential plasticity require a better understanding of the electrophysiological mechanisms underlying the known heterogeneity of afferent discharge under normal conditions. This study advances this understanding by examining the role of the Kv1 potassium channel family in mediating action potentials in specialized vestibular afferent calyx endings in the gerbil crista and utricle. Pharmacological agents selective for different sub-types of Kv1 channels were tested on membrane responses in whole cell recordings in the crista. Kv1 channels sensitive to α-dendrotoxin and dendrotoxin-K were found to prevail in the central regions, whereas K(+) channels sensitive to margatoxin, which blocks Kv1.3 and 1.6 channels, were more prominent in peripheral regions. Margatoxin-sensitive currents showed voltage-dependent inactivation. Dendrotoxin-sensitive currents showed no inactivation and dampened excitability in calyces in central neuroepithelial regions. The differential distribution of Kv1 potassium channels in vestibular afferents supports their importance in accurately relaying gravitational and head movement signals through specialized lines to the central nervous system. Pharmacological modulation of specific groups of K(+) channels could help alleviate vestibular dysfunction on earth and in space. PMID:26082693

  19. Heat pulse excitability of vestibular hair cells and afferent neurons.

    PubMed

    Rabbitt, Richard D; Brichta, Alan M; Tabatabaee, Hessam; Boutros, Peter J; Ahn, JoongHo; Della Santina, Charles C; Poppi, Lauren A; Lim, Rebecca

    2016-08-01

    In the present study we combined electrophysiology with optical heat pulse stimuli to examine thermodynamics of membrane electrical excitability in mammalian vestibular hair cells and afferent neurons. We recorded whole cell currents in mammalian type II vestibular hair cells using an excised preparation (mouse) and action potentials (APs) in afferent neurons in vivo (chinchilla) in response to optical heat pulses applied to the crista (ΔT ≈ 0.25°C per pulse). Afferent spike trains evoked by heat pulse stimuli were diverse and included asynchronous inhibition, asynchronous excitation, and/or phase-locked APs synchronized to each infrared heat pulse. Thermal responses of membrane currents responsible for APs in ganglion neurons were strictly excitatory, with Q10 ≈ 2. In contrast, hair cells responded with a mix of excitatory and inhibitory currents. Excitatory hair cell membrane currents included a thermoelectric capacitive current proportional to the rate of temperature rise (dT/dt) and an inward conduction current driven by ΔT An iberiotoxin-sensitive inhibitory conduction current was also evoked by ΔT, rising in <3 ms and decaying with a time constant of ∼24 ms. The inhibitory component dominated whole cell currents in 50% of hair cells at -68 mV and in 67% of hair cells at -60 mV. Responses were quantified and described on the basis of first principles of thermodynamics. Results identify key molecular targets underlying heat pulse excitability in vestibular sensory organs and provide quantitative methods for rational application of optical heat pulses to examine protein biophysics and manipulate cellular excitability. PMID:27226448

  20. Effects of Bothrops asper Snake Venom on Lymphatic Vessels: Insights into a Hidden Aspect of Envenomation

    PubMed Central

    Mora, Javier; Mora, Rodrigo; Lomonte, Bruno; Gutiérrez, José María

    2008-01-01

    Background Envenomations by the snake Bothrops asper represent a serious medical problem in Central America and parts of South America. These envenomations concur with drastic local tissue pathology, including a prominent edema. Since lymph flow plays a role in the maintenance of tissue fluid balance, the effect of B. asper venom on collecting lymphatic vessels was studied. Methodology/Principal Findings B. asper venom was applied to mouse mesentery, and the effects were studied using an intravital microscopy methodology coupled with an image analysis program. B. asper venom induced a dose-dependent contraction of collecting lymphatic vessels, resulting in a reduction of their lumen and in a halting of lymph flow. The effect was reproduced by a myotoxic phospholipase A2 (PLA2) homologue isolated from this venom, but not by a hemorrhagic metalloproteinase or a coagulant thrombin-like serine proteinase. In agreement with this, treatment of the venom with fucoidan, a myotoxin inhibitor, abrogated the effect, whereas no inhibition was observed after incubation with the peptidomimetic metalloproteinase inhibitor Batimastat. Moreover, fucoidan significantly reduced venom-induced footpad edema. The myotoxic PLA2 homologue, known to induce skeletal muscle necrosis, was able to induce cytotoxicity in smooth muscle cells in culture and to promote an increment in the permeability to propidium iodide in these cells. Conclusions/Significance Our observations indicate that B. asper venom affects collecting lymphatic vessels through the action of myotoxic PLA2s on the smooth muscle of these vessels, inducing cell contraction and irreversible cell damage. This activity may play an important role in the pathogenesis of the pronounced local edema characteristic of viperid snakebite envenomation, as well as in the systemic biodistribution of the venom, thus representing a potential therapeutical target in these envenomations. PMID:18923712

  1. The effect of succinylcholine on cat gastrocnemius muscle spindle afferents of different types.

    PubMed

    Taylor, A; Rodgers, J F; Fowle, A J; Durbaba, R

    1992-10-01

    1. A population of 269 gastrocnemius muscle spindle afferents have been studied in anaesthetized cats for the effects of succinylcholine (SCh) on their response to ramp and hold stretches repeated every 6 s. The effectiveness and reliability of the SCh test was improved by prior stimulation of the muscle at 10 Hz for 30 s to increase the blood flow. 2. Responses have been assessed from averaged cycle histograms before and after a single I.V. dose of SCh of 200 micrograms kg-1. As for previous studies of jaw muscle spindles the basic measurements were initial frequency (IF), peak frequency (PF) and static index (SI), the frequency 0.5 s after the end of the ramp of stretch. Dynamic difference (DD = PF-IF), dynamic index (DI = PF-SI) and static difference (SD = SI-IF) were derived from these and increases caused by SCh indicated by the prefix delta. 3. delta DD and delta IF were each distributed bimodally and since they were uncorrelated formed the basis for a four-way classification. Since delta DD can be attributed to activation of bag1 (b1) intrafusal fibres and delta IF to bag2 (b2) fibres, while all afferents receive input from chain (c) fibres it is proposed as with the jaw spindles that the classes correspond to predominant influence from b1c, b1b2c, b2c and c intrafusal fibres. 4. The proportion of units in the different groups were similar to those in the jaw muscles except for there being very few b1c type in gastrocnemius. 5. Conduction velocity was bimodally distributed with the best dividing line at 63.2 m s-1. The b1b2c units were all, save one, in the fast group, while the b2c units were equally divided between fast and slow. 6. Mean control values for DD did not differ between the b1b2c and the b2c groups, which is taken to indicate that the b1 fibre does not contribute significantly to the dynamic stretch response of spindles with no intrafusal contraction. 7. The results emphasize the importance of recognizing that some apparently primary afferents

  2. Peripheral innervation patterns of vestibular nerve afferents in the bullfrog utriculus

    NASA Technical Reports Server (NTRS)

    Baird, Richard A.; Schuff, N. R.

    1994-01-01

    Vestibular nerve afferents innervating the bullfrog utriculus differ in their response dynamics and sensitivity to natural stimulation. They also supply hair cells that differ markedly in hair bundle morphology. To examine the peripheral innervation patterns of individual utricular afferents more closely, afferent fibers were labeled by the extracellular injection of horseradish peroxidase (HRP) into the vestibular nerve after sectioning the vestibular nerve medial to Scarpa's ganglion to allow the degeneration of sympathetic and efferent fibers. The peripheral arborizations of individual afferents were then correlated with the diameters of their parent axons, the regions of the macula they innervate, and the number and type of hair cells they supply. The utriculus is divided by the striola, a narrow zone of distinctive morphology, into media and lateral parts. Utiricular afferents were classified as striolar or extrastriolar according to the epithelial entrance of their parent axons and the location of their terminal fields. In general, striolar afferents had thicker parent axons, fewer subepithelial bifurcations, larger terminal fields, and more synaptic endings than afferents in extrstriolar regions. Afferents in a juxtastriolar zone, immediately adjacent to the medial striola, had innervation patterns transitional between those in the striola and more peripheral parts of the medial extrastriola. moast afferents innervated only a single macular zone. The terminal fields of striolar afferents, with the notable exception of a few afferents with thin parent axons, were generally confined to one side of the striola. Hair cells in the bullfrog utriculus have perviously been classified into four types based on hair bundle morphology. Afferents in the extrastriolar and juxtastriolar zones largely or exclusively innervated Type B hair cells, the predominant hair cell type in the utricular macula. Striolar afferents supplied a mixture of four hair cell types, but largely

  3. Lymphatic vessels in the developing diaphragm of the rat.

    PubMed

    Poggi, P; Marchetti, C; Calligaro, A; Casasco, A; Scelsi, R

    1991-01-01

    Diaphragms of fetal, neonatal and young albino rats have been observed both under light and electron microscopes to examine the presence and distribution of lymphatic vessels and their morphological features. In fetal diaphragms of between 18 and 22 days of gestation, no normal lymphatic vessels can be seen; only after birth, specifically in neonatal and 2-day-old rats, small lymphatic vessels appear; they are in close proximity to the blood vessels in the inner areas of the muscle. As the rats get older, lymphatic vessels are also observed in the subserosa where an abundant connective tissue is present. The fine structure of diaphragmatic lymphatic vessels is different at different ages. In neonatal rats of up to 2 days, the endothelial wall is very thin and often holed. The relationships between contiguous endothelial cells are characterized by simple end-to-end or overlapping structures. The basement membrane is virtually absent. Within the first week of life, the endothelial wall becomes more complex; along the wall, complex interdigitations between two contiguous endothelial cells often touch. A discontinuous basement membrane and collagen and elastic fibers surround the vessels. In the older rats (from 14 to 25 to 140 days), next to the complex interdigitations which characterize the junction between two contiguous endothelial cells, cellular flaps interdigitate forming a channel which opens out either to the exterior or the interior of the vessel. Dense bundles of elastic and collagen fibers are closely apposed to the endothelial wall.

  4. Structural and functional features of central nervous system lymphatic vessels.

    PubMed

    Louveau, Antoine; Smirnov, Igor; Keyes, Timothy J; Eccles, Jacob D; Rouhani, Sherin J; Peske, J David; Derecki, Noel C; Castle, David; Mandell, James W; Lee, Kevin S; Harris, Tajie H; Kipnis, Jonathan

    2015-07-16

    One of the characteristics of the central nervous system is the lack of a classical lymphatic drainage system. Although it is now accepted that the central nervous system undergoes constant immune surveillance that takes place within the meningeal compartment, the mechanisms governing the entrance and exit of immune cells from the central nervous system remain poorly understood. In searching for T-cell gateways into and out of the meninges, we discovered functional lymphatic vessels lining the dural sinuses. These structures express all of the molecular hallmarks of lymphatic endothelial cells, are able to carry both fluid and immune cells from the cerebrospinal fluid, and are connected to the deep cervical lymph nodes. The unique location of these vessels may have impeded their discovery to date, thereby contributing to the long-held concept of the absence of lymphatic vasculature in the central nervous system. The discovery of the central nervous system lymphatic system may call for a reassessment of basic assumptions in neuroimmunology and sheds new light on the aetiology of neuroinflammatory and neurodegenerative diseases associated with immune system dysfunction.

  5. FOXC2 and FLT4 Gene Variants in Lymphatic Filariasis.

    PubMed

    Sheik, Yasmeen; Qureshi, Sameera Fatima; Mohhammed, Basheeruddin; Nallari, Pratibha

    2015-06-01

    Lymphatic filariasis is the leading cause of secondary lymphedema wherein lymph transport is impaired due to lymphatic damage. FLT4 signaling and transcription factors such as FOXC2 play an important role in this type of lymphangiogenesis process induced by filarial parasites. The present study aims to assess the association of FLT4 and FOXC2 genes in lymphatic development/remodeling in lymphatic filariasis. A total of 118 lymphatic filariasis patients and 100 non-endemic and 50 endemic healthy subjects were enrolled for the present study. Allele-specific PCR and PCR-RFLP were adopted for the genotyping, and screening of FLT4 and FOXC2 genes was carried out by PCR-SSCP, followed by in-silico and statistical analysis. A novel variation (G357A SNP) was identified on FOXC2 gene screening that may have an effect on codon usage frequency during translational process. In FLT4, A3123G mutation was found in 3.39% of the case subjects but the functional role of this mutation, along with subject's clinical presentations and patient's age, emphasize its pathogenic role in lymphedema development. Two of the subjects exhibit compound heterozygosity (A3123G FLT4 mutation and G357A SNP of FOXC2 gene). As these two genes share a common pathway, we hypothesise a synergistic interaction of these two SNPs in inhibiting the downstream signaling resulting in lymphedema progression.

  6. Elimination of Lymphatic Filariasis in The Gambia

    PubMed Central

    Rebollo, Maria P.; Sambou, Sana Malang; Thomas, Brent; Biritwum, Nana-Kwadwo; Jaye, Momodou C.; Kelly-Hope, Louise; Escalada, Alba Gonzalez; Molyneux, David H.; Bockarie, Moses J.

    2015-01-01

    Background The prevalence of Wuchereria bancrofti, which causes lymphatic filariasis (LF) in The Gambia was among the highest in Africa in the 1950s. However, surveys conducted in 1975 and 1976 revealed a dramatic decline in LF endemicity in the absence of mass drug administration (MDA). The decline in prevalence was partly attributed to a significant reduction in mosquito density through the widespread use of insecticidal nets. Based on findings elsewhere that vector control alone can interrupt LF, we asked the question in 2013 whether the rapid scale up in the use of insecticidal nets in The Gambia had interrupted LF transmission. Methodology/Principal Finding We present here the results of three independently designed filariasis surveys conducted over a period of 17 years (1997–2013), and involving over 6000 subjects in 21 districts across all administrative divisions in The Gambia. An immunochromatographic (ICT) test was used to detect W. bancrofti antigen during all three surveys. In 2001, tests performed on stored samples collected between 1997 and 2000, in three divisions, failed to show positive individuals from two divisions that were previously highly endemic for LF, suggesting a decline towards extinction in some areas. Results of the second survey conducted in 2003 showed that LF was no longer endemic in 16 of 21 districts surveyed. The 2013 survey used a WHO recommended LF transmission verification tool involving 3180 6–7 year-olds attending 60 schools across the country. We demonstrated that transmission of W. bancrofti has been interrupted in all 21 districts. Conclusions We conclude that LF transmission may have been interrupted in The Gambia through the extensive use of insecticidal nets for malaria control for decades. The growing evidence for the impact of malaria vector control activities on parasite transmission has been endorsed by WHO through a position statement in 2011 on integrated vector management to control malaria and LF. PMID

  7. [Muscle afferent block for the treatment of writer's cramp].

    PubMed

    Sawamoto, N; Kaji, R; Katayama, M; Kubori, T; Kimura, J

    1995-11-01

    A 29-year-old man suffered from dystonic writer's cramp for over three years. When he wrote, typed and did other tasks using right hand, dystonic involuntary movement triggered medial rotation of the arm, wrist extension and shoulder elevation. Medication, biofeedback, and botulinum injection were performed without much success. We tried to block the sensory input from muscles by using lidocaine and ethanol. We made injections of 0.5% lidocaine 50ml and 99% ethanol 5ml into muscles with abnormal activity at the frequency of twice a week for about six months. After the treatment, dystonic movement was remarkably improved and he was then able to write, type and perform other tasks with the right hand. Side effects included pain of the injection site, nausea and dizziness, which lasted for a few hours. This "muscle afferent block" did not cause muscle weakness. We speculate that muscle afferent plays a pivotal role in dystonia so that its blocking may be of clinical use.

  8. Interactions between visceral afferent signaling and stimulus processing.

    PubMed

    Critchley, Hugo D; Garfinkel, Sarah N

    2015-01-01

    Visceral afferent signals to the brain influence thoughts, feelings and behavior. Here we highlight the findings of a set of empirical investigations in humans concerning body-mind interaction that focus on how feedback from states of autonomic arousal shapes cognition and emotion. There is a longstanding debate regarding the contribution of the body to mental processes. Recent theoretical models broadly acknowledge the role of (autonomically-mediated) physiological arousal to emotional, social and motivational behaviors, yet the underlying mechanisms are only partially characterized. Neuroimaging is overcoming this shortfall; first, by demonstrating correlations between autonomic change and discrete patterns of evoked, and task-independent, neural activity; second, by mapping the central consequences of clinical perturbations in autonomic response and; third, by probing how dynamic fluctuations in peripheral autonomic state are integrated with perceptual, cognitive and emotional processes. Building on the notion that an important source of the brain's representation of physiological arousal is derived from afferent information from arterial baroreceptors, we have exploited the phasic nature of these signals to show their differential contribution to the processing of emotionally-salient stimuli. This recent work highlights the facilitation at neural and behavioral levels of fear and threat processing that contrasts with the more established observations of the inhibition of central pain processing during baroreceptors activation. The implications of this body-brain-mind axis are discussed. PMID:26379481

  9. Cross-Modal Calibration of Vestibular Afference for Human Balance.

    PubMed

    Héroux, Martin E; Law, Tammy C Y; Fitzpatrick, Richard C; Blouin, Jean-Sébastien

    2015-01-01

    To determine how the vestibular sense controls balance, we used instantaneous head angular velocity to drive a galvanic vestibular stimulus so that afference would signal that head movement was faster or slower than actual. In effect, this changed vestibular afferent gain. This increased sway 4-fold when subjects (N = 8) stood without vision. However, after a 240 s conditioning period with stable balance achieved through reliable visual or somatosensory cues, sway returned to normal. An equivalent galvanic stimulus unrelated to sway (not driven by head motion) was equally destabilising but in this situation the conditioning period of stable balance did not reduce sway. Reflex muscle responses evoked by an independent, higher bandwidth vestibular stimulus were initially reduced in amplitude by the galvanic stimulus but returned to normal levels after the conditioning period, contrary to predictions that they would decrease after adaptation to increased sensory gain and increase after adaptation to decreased sensory gain. We conclude that an erroneous vestibular signal of head motion during standing has profound effects on balance control. If it is unrelated to current head motion, the CNS has no immediate mechanism of ignoring the vestibular signal to reduce its influence on destabilising balance. This result is inconsistent with sensory reweighting based on disturbances. The increase in sway with increased sensory gain is also inconsistent with a simple feedback model of vestibular reflex action. Thus, we propose that recalibration of a forward sensory model best explains the reinterpretation of an altered reafferent signal of head motion during stable balance. PMID:25894558

  10. Spontaneous hyperactivity in the auditory midbrain: relationship to afferent input.

    PubMed

    Robertson, Donald; Bester, Christofer; Vogler, Darryl; Mulders, Wilhelmina H A M

    2013-01-01

    Hyperactivity in the form of increased spontaneous firing rates of single neurons develops in the guinea pig inferior colliculus (IC) after unilateral loud sound exposures that result in behavioural signs of tinnitus. The hyperactivity is found in those parts of the topographic frequency map in the IC where neurons possess characteristic frequencies (CFs) closely related to the region in the cochlea where lasting sensitivity changes occur as a result of the loud sound exposure. The observed hyperactivity could be endogenous to the IC, or it could be driven by hyperactivity at lower stages of the auditory pathway. In addition to the dorsal cochlear nucleus (DCN) hyperactivity reported by others, specific cell types in the ventral cochlear nucleus (VCN) also show hyperactivity in this animal model suggesting that increased drive from several regions of the lower brainstem could contribute to the observed hyperactivity in the midbrain. In addition, spontaneous afferent drive from the cochlea itself is necessary for the maintenance of hyperactivity up to about 8 weeks post cochlear trauma. After 8 weeks however, IC hyperactivity becomes less dependent on cochlear input, suggesting that central neurons transition from a state of hyperexcitability to a state in which they generate their own endogenous firing. The results suggest that there might be a "therapeutic window" for early-onset tinnitus, using treatments that reduce cochlear afferent firing. PMID:22349094

  11. Cross-Modal Calibration of Vestibular Afference for Human Balance

    PubMed Central

    Héroux, Martin E; Law, Tammy C. Y.; Fitzpatrick, Richard C.; Blouin, Jean-Sébastien

    2015-01-01

    To determine how the vestibular sense controls balance, we used instantaneous head angular velocity to drive a galvanic vestibular stimulus so that afference would signal that head movement was faster or slower than actual. In effect, this changed vestibular afferent gain. This increased sway 4-fold when subjects (N = 8) stood without vision. However, after a 240 s conditioning period with stable balance achieved through reliable visual or somatosensory cues, sway returned to normal. An equivalent galvanic stimulus unrelated to sway (not driven by head motion) was equally destabilising but in this situation the conditioning period of stable balance did not reduce sway. Reflex muscle responses evoked by an independent, higher bandwidth vestibular stimulus were initially reduced in amplitude by the galvanic stimulus but returned to normal levels after the conditioning period, contrary to predictions that they would decrease after adaptation to increased sensory gain and increase after adaptation to decreased sensory gain. We conclude that an erroneous vestibular signal of head motion during standing has profound effects on balance control. If it is unrelated to current head motion, the CNS has no immediate mechanism of ignoring the vestibular signal to reduce its influence on destabilising balance. This result is inconsistent with sensory reweighting based on disturbances. The increase in sway with increased sensory gain is also inconsistent with a simple feedback model of vestibular reflex action. Thus, we propose that recalibration of a forward sensory model best explains the reinterpretation of an altered reafferent signal of head motion during stable balance. PMID:25894558

  12. Interactions between visceral afferent signaling and stimulus processing

    PubMed Central

    Critchley, Hugo D.; Garfinkel, Sarah N.

    2015-01-01

    Visceral afferent signals to the brain influence thoughts, feelings and behavior. Here we highlight the findings of a set of empirical investigations in humans concerning body-mind interaction that focus on how feedback from states of autonomic arousal shapes cognition and emotion. There is a longstanding debate regarding the contribution of the body to mental processes. Recent theoretical models broadly acknowledge the role of (autonomically-mediated) physiological arousal to emotional, social and motivational behaviors, yet the underlying mechanisms are only partially characterized. Neuroimaging is overcoming this shortfall; first, by demonstrating correlations between autonomic change and discrete patterns of evoked, and task-independent, neural activity; second, by mapping the central consequences of clinical perturbations in autonomic response and; third, by probing how dynamic fluctuations in peripheral autonomic state are integrated with perceptual, cognitive and emotional processes. Building on the notion that an important source of the brain's representation of physiological arousal is derived from afferent information from arterial baroreceptors, we have exploited the phasic nature of these signals to show their differential contribution to the processing of emotionally-salient stimuli. This recent work highlights the facilitation at neural and behavioral levels of fear and threat processing that contrasts with the more established observations of the inhibition of central pain processing during baroreceptors activation. The implications of this body-brain-mind axis are discussed. PMID:26379481

  13. Microsecond-Scale Timing Precision in Rodent Trigeminal Primary Afferents

    PubMed Central

    Bale, Michael R.; Campagner, Dario; Erskine, Andrew

    2015-01-01

    Communication in the nervous system occurs by spikes: the timing precision with which spikes are fired is a fundamental limit on neural information processing. In sensory systems, spike-timing precision is constrained by first-order neurons. We found that spike-timing precision of trigeminal primary afferents in rats and mice is limited both by stimulus speed and by electrophysiological sampling rate. High-speed video of behaving mice revealed whisker velocities of at least 17,000°/s, so we delivered an ultrafast “ping” (>50,000°/s) to single whiskers and sampled primary afferent activity at 500 kHz. Median spike jitter was 17.4 μs; 29% of neurons had spike jitter < 10 μs. These results indicate that the input stage of the trigeminal pathway has extraordinary spike-timing precision and very high potential information capacity. This timing precision ranks among the highest in biology. PMID:25878266

  14. Anatomy and development of the cardiac lymphatic vasculature: Its role in injury and disease.

    PubMed

    Norman, Sophie; Riley, Paul R

    2016-04-01

    Lymphatic vessels are present throughout the entire body in all mammals and function to regulate tissue fluid balance, lipid transport and survey the immune system. Despite the presence of an extensive lymphatic plexus within the heart, until recently the importance of the cardiac lymphatic vasculature and its origins were unknown. Several studies have described the basic anatomy of the developing cardiac lymphatic vasculature and more recently the detailed development of the murine cardiac lymphatics has been documented, with important insight into their cellular sources during embryogenesis. In this review we initially describe the development of systemic lymphatic vasculature, to provide the background for a comparative description of the spatiotemporal development of the cardiac lymphatic vessels, including detail of both canonical, typically venous, and noncanonical (hemogenic endothelium) cellular sources. Subsequently, we address the response of the cardiac lymphatic network to myocardial infarction (heart attack) and the therapeutic potential of targeting cardiac lymphangiogenesis.

  15. From sewer to saviour - targeting the lymphatic system to promote drug exposure and activity.

    PubMed

    Trevaskis, Natalie L; Kaminskas, Lisa M; Porter, Christopher J H

    2015-11-01

    The lymphatic system serves an integral role in fluid homeostasis, lipid metabolism and immune control. In cancer, the lymph nodes that drain solid tumours are a primary site of metastasis, and recent studies have suggested intrinsic links between lymphatic function, lipid deposition, obesity and atherosclerosis. Advances in the current understanding of the role of the lymphatics in pathological change and immunity have driven the recognition that lymph-targeted delivery has the potential to transform disease treatment and vaccination. In addition, the design of lymphatic delivery systems has progressed from simple systems that rely on passive lymphatic access to sophisticated structures that use nanotechnology to mimic endogenous macromolecules and lipid conjugates that 'hitchhike' onto lipid transport processes. Here, we briefly summarize the lymphatic system in health and disease and the varying mechanisms of lymphatic entry and transport, as well as discussing examples of lymphatic delivery that have enhanced therapeutic utility. We also outline future challenges to effective lymph-directed therapy.

  16. Anatomy and development of the cardiac lymphatic vasculature: Its role in injury and disease.

    PubMed

    Norman, Sophie; Riley, Paul R

    2016-04-01

    Lymphatic vessels are present throughout the entire body in all mammals and function to regulate tissue fluid balance, lipid transport and survey the immune system. Despite the presence of an extensive lymphatic plexus within the heart, until recently the importance of the cardiac lymphatic vasculature and its origins were unknown. Several studies have described the basic anatomy of the developing cardiac lymphatic vasculature and more recently the detailed development of the murine cardiac lymphatics has been documented, with important insight into their cellular sources during embryogenesis. In this review we initially describe the development of systemic lymphatic vasculature, to provide the background for a comparative description of the spatiotemporal development of the cardiac lymphatic vessels, including detail of both canonical, typically venous, and noncanonical (hemogenic endothelium) cellular sources. Subsequently, we address the response of the cardiac lymphatic network to myocardial infarction (heart attack) and the therapeutic potential of targeting cardiac lymphangiogenesis. PMID:26443964

  17. Recent advances in lymphatic targeted drug delivery system for tumor metastasis

    PubMed Central

    Zhang, Xiao-Yu; Lu, Wei-Yue

    2014-01-01

    The lymphatic system has an important defensive role in the human body. The metastasis of most tumors initially spreads through the surrounding lymphatic tissue and eventually forms lymphatic metastatic tumors; the tumor cells may even transfer to other organs to form other types of tumors. Clinically, lymphatic metastatic tumors develop rapidly. Given the limitations of surgical resection and the low effectiveness of radiotherapy and chemotherapy, the treatment of lymphatic metastatic tumors remains a great challenge. Lymph node metastasis may lead to the further spread of tumors and may be predictive of the endpoint event. Under these circumstances, novel and effective lymphatic targeted drug delivery systems have been explored to improve the specificity of anticancer drugs to tumor cells in lymph nodes. In this review, we summarize the principles of lymphatic targeted drug delivery and discuss recent advances in the development of lymphatic targeted carriers. PMID:25610710

  18. The Lymphatic Endothelial mCLCA1 Antibody Induces Proliferation and Growth of Lymph Node Lymphatic Sinuses.

    PubMed

    Jordan-Williams, Kimberly L; Ramanujam, Neela; Farr, Andrew G; Ruddell, Alanna

    2016-01-01

    Lymphocyte- and leukocyte-mediated lymph node (LN) lymphatic sinus growth (lymphangiogenesis) is involved in immune responses and in diseases including cancer and arthritis. We previously discovered a 10.1.1 Ab that recognizes the lymphatic endothelial cell (LEC) surface protein mCLCA1, which is an interacting partner for LFA1 and Mac-1 that mediates lymphocyte adhesion to LECs. Here, we show that 10.1.1 Ab treatment specifically induces LEC proliferation, and influences migration and adhesion in vitro. Functional testing by injection of mice with 10.1.1 Ab but not control hamster Abs identified rapid induction of LN LEC proliferation and extensive lymphangiogenesis within 23 h. BrdU pulse-chase analysis demonstrated incorporation of proliferating LYVE-1-positive LEC into the growing medullary lymphatic sinuses. The 10.1.1 Ab-induced LN remodeling involved coordinate increases in LECs and also blood endothelial cells, fibroblastic reticular cells, and double negative stroma, as is observed during the LN response to inflammation. 10.1.1 Ab-induced lymphangiogenesis was restricted to LNs, as mCLCA1-expressing lymphatic vessels of the jejunum and dermis were unaffected by 23 h 10.1.1 Ab treatment. These findings demonstrate that 10.1.1 Ab rapidly and specifically induces proliferation and growth of LN lymphatic sinuses and stroma, suggesting a key role of mCLCA1 in coordinating LN remodeling during immune responses. PMID:27224029

  19. The Lymphatic Endothelial mCLCA1 Antibody Induces Proliferation and Growth of Lymph Node Lymphatic Sinuses

    PubMed Central

    Jordan-Williams, Kimberly L.; Ramanujam, Neela; Farr, Andrew G.

    2016-01-01

    Lymphocyte- and leukocyte-mediated lymph node (LN) lymphatic sinus growth (lymphangiogenesis) is involved in immune responses and in diseases including cancer and arthritis. We previously discovered a 10.1.1 Ab that recognizes the lymphatic endothelial cell (LEC) surface protein mCLCA1, which is an interacting partner for LFA1 and Mac-1 that mediates lymphocyte adhesion to LECs. Here, we show that 10.1.1 Ab treatment specifically induces LEC proliferation, and influences migration and adhesion in vitro. Functional testing by injection of mice with 10.1.1 Ab but not control hamster Abs identified rapid induction of LN LEC proliferation and extensive lymphangiogenesis within 23 h. BrdU pulse-chase analysis demonstrated incorporation of proliferating LYVE-1-positive LEC into the growing medullary lymphatic sinuses. The 10.1.1 Ab-induced LN remodeling involved coordinate increases in LECs and also blood endothelial cells, fibroblastic reticular cells, and double negative stroma, as is observed during the LN response to inflammation. 10.1.1 Ab-induced lymphangiogenesis was restricted to LNs, as mCLCA1-expressing lymphatic vessels of the jejunum and dermis were unaffected by 23 h 10.1.1 Ab treatment. These findings demonstrate that 10.1.1 Ab rapidly and specifically induces proliferation and growth of LN lymphatic sinuses and stroma, suggesting a key role of mCLCA1 in coordinating LN remodeling during immune responses. PMID:27224029

  20. Search for lymphatic drainage of the monkey orbit

    SciTech Connect

    McGetrick, J.J.; Wilson, D.G.; Dortzbach, R.K.; Kaufman, P.L.; Lemke, B.N.

    1989-02-01

    Colloid solutions of technetium Tc-99m and india ink injected into the retrobulbar space of the cynomolgus monkey outside the extraocular muscle cone were removed from the orbit by the lymphatic vessels of the conjunctiva and eyelids and were then concentrated within the lymph nodes that drained the conjunctival and eyelid areas. Colloid solutions injected into the retrobulbar space inside the extraocular muscle cone did not reach the conjunctiva and did not collect in any lymph nodes over a 24-hour period. Within the orbit, the injected colloids spread along the planes of the connective-tissue septa. No lymphatic vessels were identified within the orbits posterior to the conjunctiva. Small amounts of india ink left the posterior orbit and ultimately entered the contralateral orbit. This posterior pathway did not lead to lymphatic vessels or lymph nodes and therefore does not appear to represent a prelymphatic pathway.

  1. Emerging lymphatic imaging technologies for mouse and man

    PubMed Central

    Sevick-Muraca, Eva M.; Kwon, Sunkuk; Rasmussen, John C.

    2014-01-01

    The lymphatic circulatory system has diverse functions in lipid absorption, fluid homeostasis, and immune surveillance and responds dynamically when presented with infection, inflammation, altered hemodynamics, and cancer. Visualization of these dynamic processes in human disease and animal models of disease is key to understanding the contributory role of the lymphatic circulatory system in disease and to devising effective therapeutic strategies. Longitudinal, non-destructive, and repeated imaging is necessary to expand our understanding of disease progression and regression in basic science and clinical investigations. Herein we summarize recent advances in in vivo lymphatic imaging employing magnetic resonance, computed tomography, lymphoscintigraphy, and emerging optical techniques with respect to their contributory roles in both basic science and clinical research investigations. PMID:24590275

  2. Mechanosensitive β-catenin signaling regulates lymphatic vascular development.

    PubMed

    Cha, Boksik; Srinivasan, R Sathish

    2016-08-01

    The Wnt/β-catenin signaling is an evolutionarily conserved pathway that plays a pivotal role in embryonic development and adult homeostasis. However, we have limited information about the involvement of Wnt/β-catenin signaling in the lymphatic vascular system that regulates fluid homeostasis by absorbing interstitial fluid and returning it to blood circulation. In this recent publication we report that canonical Wnt/β-catenin signaling is highly active and critical for the formation of lymphovenus valves (LVVs) and lymphatic valves (LVs). β-catenin directly associates with the regulatory elements of the lymphedema-associated transcription factor, FOXC2 and activates its expression in an oscillatory shear stress (OSS)-dependent manner. The phenotype of β-catenin null embryos was rescued by FOXC2 overexpression. These results suggest that Wnt/β-catenin signaling is a mechanotransducer that links fluid force with lymphatic vascular development. [BMB Reports 2016; 49(8): 403-404]. PMID:27418286

  3. Disorders of the lymphatic system of the abdomen.

    PubMed

    Patil, A R; Nandikoor, S; De Marco, J; Bhat, R; Shivakumar, S; Mallrajapatna, G

    2016-10-01

    The lymphatic system of the abdomen comprises of the cisterna chyli, its major and minor lymphatic tributaries, and lymph nodes. Disorders of the lymphatic system of the abdomen are rarely encountered and consist of primary and secondary types. Abdominal lymphangiomas constitute the majority and have characteristic imaging features. Complicated lymphangiomas may pose a diagnostic dilemma. Generalised systemic lymphangiomatosis is a rare condition and affects major organs with a poor prognosis. Retroperitoneal lymphangiectasia in the appropriate setting might predict underlying infection, such as filariasis. Other acquired conditions include iatrogenic or treatment-induced chylocoele. Chylous ascites can be secondary to multiple causes and can be confirmed by biochemical testing and lymphangiogram in appropriate settings. PMID:27450410

  4. Force-sensitive afferents recruited during stance encode sensory depression in the contralateral swinging limb during locomotion.

    PubMed

    Hochman, Shawn; Hayes, Heather Brant; Speigel, Iris; Chang, Young-Hui

    2013-03-01

    Afferent feedback alters muscle activity during locomotion and must be tightly controlled. As primary afferent depolarization-induced presynaptic inhibition (PAD-PSI) regulates afferent signaling, we investigated hindlimb PAD-PSI during locomotion in an in vitro rat spinal cord-hindlimb preparation. We compared the relation of PAD-PSI, measured as dorsal root potentials (DRPs), to observed ipsilateral and contralateral limb endpoint forces. Afferents activated during stance-phase force strongly and proportionately influenced DRP magnitude in the swinging limb. Responses increased with locomotor frequency. Electrical stimulation of contralateral afferents also preferentially evoked DRPs in the opposite limb during swing (flexion). Nerve lesioning, in conjunction with kinematic results, support a prominent contribution from toe Golgi tendon organ afferents. Thus, force-dependent afferent feedback during stance binds interlimb sensorimotor state to a proportional PAD-PSI in the swinging limb, presumably to optimize interlimb coordination. These results complement known actions of ipsilateral afferents on PAD-PSI during locomotion.

  5. Measurement of shear stress-mediated intracellular calcium dynamics in human dermal lymphatic endothelial cells

    PubMed Central

    Jafarnejad, M.; Cromer, W. E.; Kaunas, R. R.; Zhang, S. L.; Zawieja, D. C.

    2015-01-01

    The shear stress applied to lymphatic endothelial cells (LEC) by lymph flow changes dramatically under normal conditions as well as in response to disease conditions and immune reactions. In general, LEC are known to regulate the contraction frequency and strength of lymphatic pumping in response to shear stress. Intracellular calcium concentration ([Ca2+]i) is an important factor that regulates lymphatic contraction characteristics. In this study, we measured changes in the [Ca2+]i under different shear stress levels and determined the source of this calcium signal. Briefly, human dermal LEC were cultured in custom-made microchannels for 3 days before loading with 2 µM fura-2 AM, a ratiometric calcium dye to measure [Ca2+]i. Step changes in shear stress resulted in a rapid increase in [Ca2+]i followed by a gradual return to the basal level and sometimes below the initial baseline (45.2 ± 2.2 nM). The [Ca2+]i reached a peak at 126.2 ± 5.6 nM for 10 dyn/cm2 stimulus, whereas the peak was only 71.8 ± 5.4 nM for 1 dyn/cm2 stimulus, indicating that the calcium signal depends on the magnitude of shear stress. Removal of the extracellular calcium from the buffer or pharmocological blockade of calcium release-activated calcium (CRAC) channels significantly reduced the peak [Ca2+]i, demonstrating a role of extracellular calcium entry. Inhibition of endoplasmic reticulum (ER) calcium pumps showed the importance of intracellular calcium stores in the initiation of this signal. In conclusion, we demonstrated that the shear-mediated calcium signal is dependent on the magnitude of the shear and involves ER store calcium release and extracellular calcium entry. PMID:25617358

  6. [Simultaneous occurrence of hemophilia A and acute lymphatic leukemia].

    PubMed

    Schmid, L; Schafroth, U; Osterwalder, B; Senn, H J

    1987-11-14

    In this paper the case of a man with haemophilia A is presented. At the age of 18 years an acute lymphatic leukaemia was observed. The case report demonstrates that even in the presence of a severe plasmatic coagulopathy an acute lymphatic leukaemia can be successfully treated with intensive chemotherapy, if the monitoring of the coagulation values and the substitution of antihaemophilic globulin and thrombocytes are guaranteed. Only 4 cases of haemophilia and acute leukaemia in the same patient are described in the literature. So we believe that the association of these two rare disorders is merely accidental.

  7. Renal peripelvic lymphatic cysts (lymphangiomas) associated with generalized lymphangiomatosis.

    PubMed

    Younathan, C M; Kaude, J V

    1992-01-01

    Renal peripelvic lymphatic cysts (lymphangiomas) are usually seen as an isolated finding. They appear as multiple mass lesions with low attenuation on computed tomography (CT), and show no contrast enhancement. We present a case of renal peripelvic lymphatic cysts associated with generalized lymphangiomatosis, and examined with magnetic resonance imaging (MRI), CT, and lymphangiography. Multiplanar MRI demonstrated the extent of disease, including retroperitoneal lesions. The lesions had low-signal intensity on T1-weighted and high-signal intensity on T2-weighted images. The diagnosis of generalized lymphangiomatosis was verified by renal sinus cyst puncture, lymphangiography, and tissue biopsy.

  8. Lymphatic disorders after renal transplantation: new insights for an old complication

    PubMed Central

    Ranghino, Andrea; Segoloni, Giuseppe Paolo; Lasaponara, Fedele; Biancone, Luigi

    2015-01-01

    In renal transplanted patients, lymphoceles and lymphorrhea are well-known lymphatic complications. Surgical damage of the lymphatics of the graft during the procurement and of the lymphatic around the iliac vessels of the recipients has been associated with development of lymphatic complications. However, lymphatic complications may be related to medical factors such as diabetes, obesity, blood coagulation abnormalities, anticoagulation prophylaxis, high dose of diuretics, delay in graft function and immunosuppressive drugs. Consistently, immunosuppression regimens based on the use of mTOR inhibitors, especially in association with steroids and immediately after transplantation, has been associated with a high risk to develop lymphocele or lymphorrhea. In addition, several studies have demonstrated the association between rejection episodes and lymphatic complications. However, before the discovery of reliable markers of lymphatic vessels, the pathogenic mechanisms underlining the development of lymphatic complications during rejection and the influence of mTOR inhibitors remained not fully understood. The recent findings on the lymphatic systems of either native or transplanted kidneys together with the advances achieved on lymphangiogenesis shared some lights on the pathogenesis of lymphatic complications after renal transplantation. In this review, we describe the surgical and medical causes of lymphatic complications focusing on the rejection and immunosuppressive drugs as causes of lymphatic complications. PMID:26413290

  9. Lack of functioning intratumoral lymphatics in colon and pancreas cancer tissue.

    PubMed

    Olszewski, Waldemar L; Stanczyk, Marek; Gewartowska, Magdalena; Domaszewska-Szostek, Anna; Durlik, Marek

    2012-09-01

    There are controversial views as to whether intratumoral or peritumoral lymphatics play a dominant role in the metastatic process. Most clinical observations originate from studies of colon cancer. Colon contains mucosa and submucosa rich in lymphatics and with high lymph formation rate. This seems to be a prerequisite for easy metastasis of cancer cells to regional lymph nodes. However, there are other tissues as pancreas with a rudimentary lymphatic network where cancer metastasis formation is as intensive as in colon cancer. This contradicts the common notion that intratumor lymphatics play major role in metastases. We visualized interstitial space and lymphatics in the central and peripheral regions of colon and pancreas tumors using the color stereoscopic lymphography and simultaneously immunohistochemical performed stainings specific for lymphatic and blood endothelial cells. The density of open and compressed lymphatic and blood vessels was measured in the tumor core and edge. There were very few lymphatics in the colon and pancreas tumor core but numerous minor fluid "lakes" with no visible connection to the peritumoral lymphatics. Lining of "lakes" did not express molecular markers specific for lymphatic endothelial cells. Dense connective tissue surrounding tumor foci did not contain lymphatics. Peritumoral lymphatics were irregularly distributed in both types of tumor and only sporadically contained cells that might be tumor cells. Similar lymphoscintigraphic and histological pictures were seen in colon and pancreas cancer despite of different structure of both tissues. This suggests a uniform reaction of tissues to the growing cancer irrespective of the affected organ.

  10. Development of diaphragmatic lymphatics: the process of their direct connection to the peritoneal cavity.

    PubMed

    Shao, X J; Ohtani, O; Saitoh, M; Ohtani, Y

    1998-05-01

    The development of the lymphatic system in the rat diaphragm was studied from embryonic day 16 to 25 weeks after birth by histochemistry for 5'-nucleotidase, scanning electron microscopy of KOH-treated or intact tissues, and transmission electron microscopy of thin sections. On embryonic day 16, distinct lymphatics were noted in the subpleural space of the diaphragm periphery. The endothelial cells at this stage contained an abundance of rough endoplasmic reticulum, a developed Golgi apparatus and mitochondria, and fewer pinocytotic vesicles than those in adults. The subpleural lymphatics subsequently increased and formed a polygonal network. They possessed many valves, and by postnatal week 6, some thick collecting lymphatics became endowed with smooth muscle cells. On embryonic day 19, some lymphatics appeared in the subperitoneal space. They extended centripetally and had many lateral projections that subsequently became elongated and connected with those from adjacent lymphatics, thus forming a lattice-like network. During the early postnatal days, the subperitoneal lymphatics projected many bulges that subsequently became elongated, and came into contact with the pores among the mesothelial cells, thus forming lymphatic stomata connecting the lymphatic lacunae to the peritoneal cavity. The lymphatic stomata increased until postnatal week 10. The results show that lymphatics appear as early as embryonic day 16 in the subpleural space of the diaphragm periphery, and develop with age by sprouting to form networks in both the subpleural and the subperitoneal spaces, and that the direct connection of the lymphatic lacunae to the peritoneal cavity is formed after birth.

  11. 38 CFR 4.117 - Schedule of ratings-hemic and lymphatic systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and lymphatic systems. 4.117 Section 4.117 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS SCHEDULE FOR RATING DISABILITIES Disability Ratings The Hemic and Lymphatic Systems § 4.117 Schedule of ratings—hemic and lymphatic systems. Rating 7700Anemia, hypochromic-microcytic...

  12. 38 CFR 4.117 - Schedule of ratings-hemic and lymphatic systems.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... and lymphatic systems. 4.117 Section 4.117 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS SCHEDULE FOR RATING DISABILITIES Disability Ratings The Hemic and Lymphatic Systems § 4.117 Schedule of ratings—hemic and lymphatic systems. Rating 7700Anemia, hypochromic-microcytic...

  13. 38 CFR 4.117 - Schedule of ratings-hemic and lymphatic systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... and lymphatic systems. 4.117 Section 4.117 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS SCHEDULE FOR RATING DISABILITIES Disability Ratings The Hemic and Lymphatic Systems § 4.117 Schedule of ratings—hemic and lymphatic systems. Rating 7700Anemia, hypochromic-microcytic...

  14. 38 CFR 4.117 - Schedule of ratings-hemic and lymphatic systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... and lymphatic systems. 4.117 Section 4.117 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS SCHEDULE FOR RATING DISABILITIES Disability Ratings The Hemic and Lymphatic Systems § 4.117 Schedule of ratings—hemic and lymphatic systems. Rating 7700Anemia, hypochromic-microcytic...

  15. 38 CFR 4.117 - Schedule of ratings-hemic and lymphatic systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... and lymphatic systems. 4.117 Section 4.117 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS SCHEDULE FOR RATING DISABILITIES Disability Ratings The Hemic and Lymphatic Systems § 4.117 Schedule of ratings—hemic and lymphatic systems. Rating 7700Anemia, hypochromic-microcytic...

  16. Enzyme-histochemical study on postnatal development of rat stomach lymphatic vessels.

    PubMed

    Ji, R C; Kato, S

    1997-07-01

    Postnatal development of rat gastric lymphatics was studied by an enzyme-histochemical method to elucidate the morphological changes of lymphatics and their relationship to maturation and function, especially in the glandular portion. The significant features of 5'-Nase-positive lymphatics in distribution and structure were examined in different stages (within 24 hr, 4-21 days, and 2 months). Lymphatics in the greater curvature and anterior wall grew much slower than those in the lesser curvature and posterior wall of the stomach in newborn and infant rats. Lymphatic islands isolated from the primary lymphatic networks in the submucosa and subserosa underwent a morphological change during this early period. This is considered one of the basic steps in lymphatic development. Occurrence of lymphatic networks in the deep lamina propria indicates that development in the gastric wall is well characterized from Day 10. With further growth and modification of lymphatics, the networks in the different layers formed an extensive communication network and many lymphatic valves were found in the submucosa and subserosa. Pinocytotic vesicles, open junctions, and intraendothelial channels were frequently detected in the mucosal and submucosal lymphatic networks of the corpus-antrum and antrum-duodenum divisional zones in the adult rats. These findings suggest that developing lymphatics in the rat stomach may represent rapidly growing tissue not only with high 5'-Nase activity but also with high adaptability for future physiological demands.

  17. Functional recovery of anterior semicircular canal afferents following hair cell regeneration in birds

    NASA Technical Reports Server (NTRS)

    Boyle, Richard; Highstein, Stephen M.; Carey, John P.; Xu, Jinping

    2002-01-01

    Streptomycin sulfate (1.2 g/kg i.m.) was administered for 5 consecutive days to 5-7-day-old white Leghorn chicks; this causes damage to semicircular canal hair cells that ultimately regenerate to reform the sensory epithelium. During the recovery period, electrophysiological recordings were taken sequentially from anterior semicircular canal primary afferents using an indentation stimulus of the canal that has been shown to mimic rotational stimulation. Chicks were assigned to an early (14-18 days; n = 8), intermediate (28-34 days; n = 5), and late (38-58 days; n = 4) period based on days after treatment. Seven untreated chicks, 15-67 days old, provided control data. An absence of background and indent-induced discharge was the prominent feature of afferents in the early period: only "silent" afferents were encountered in 5/8 experiments. In several of these chicks, fascicles of afferent fibers were seen extending up to the epithelium that was void of hair cells, and intra- and extracellular biocytin labeling revealed afferent processes penetrating into the supporting cell layer of the crista. In 3/8 chicks 74 afferents could be characterized, and they significantly differed from controls (n = 130) by having a lower discharge rate and a negligible response to canal stimulation. In the intermediate period there was considerable variability in discharge properties of 121 afferents, but as a whole the number of "silent" fibers in the canal nerve diminished, the background rate increased, and a response to canal stimulation detected. Individually biocytin-labeled afferents had normal-appearing terminal specializations in the sensory epithelium by 28 days poststreptomycin. In the late period, afferents (n = 58) remained significantly different from controls in background discharge properties and response gain. The evidence suggests that a considerable amount of variability exists between chicks in the return of vestibular afferent function following ototoxic injury and

  18. Afferent and motoneuron activity in response to single neuromast stimulation in the posterior lateral line of larval zebrafish.

    PubMed

    Haehnel-Taguchi, Melanie; Akanyeti, Otar; Liao, James C

    2014-09-15

    The lateral line system of fishes contains mechanosensory receptors along the body surface called neuromasts, which can detect water motion relative to the body. The ability to sense flow informs many behaviors, such as schooling, predator avoidance, and rheotaxis. Here, we developed a new approach to stimulate individual neuromasts while either recording primary sensory afferent neuron activity or swimming motoneuron activity in larval zebrafish (Danio rerio). Our results allowed us to characterize the transfer functions between a controlled lateral line stimulus, its representation by primary sensory neurons, and its subsequent behavioral output. When we deflected the cupula of a neuromast with a ramp command, we found that the connected afferent neuron exhibited an adapting response which was proportional in strength to deflection velocity. The maximum spike rate of afferent neurons increased sigmoidally with deflection velocity, with a linear range between 0.1 and 1.0 μm/ms. However, spike rate did not change when the cupula was deflected below 8 μm, regardless of deflection velocity. Our findings also reveal an unexpected sensitivity in the larval lateral line system: stimulation of a single neuromast could elicit a swimming response which increased in reliability with increasing deflection velocities. At high deflection velocities, we observed that lateral line evoked swimming has intermediate values of burst frequency and duty cycle that fall between electrically evoked and spontaneous swimming. An understanding of the sensory capabilities of a single neuromast will help to build a better picture of how stimuli are encoded at the systems level and ultimately translated into behavior.

  19. Afferent and motoneuron activity in response to single neuromast stimulation in the posterior lateral line of larval zebrafish

    PubMed Central

    Haehnel-Taguchi, Melanie; Akanyeti, Otar

    2014-01-01

    The lateral line system of fishes contains mechanosensory receptors along the body surface called neuromasts, which can detect water motion relative to the body. The ability to sense flow informs many behaviors, such as schooling, predator avoidance, and rheotaxis. Here, we developed a new approach to stimulate individual neuromasts while either recording primary sensory afferent neuron activity or swimming motoneuron activity in larval zebrafish (Danio rerio). Our results allowed us to characterize the transfer functions between a controlled lateral line stimulus, its representation by primary sensory neurons, and its subsequent behavioral output. When we deflected the cupula of a neuromast with a ramp command, we found that the connected afferent neuron exhibited an adapting response which was proportional in strength to deflection velocity. The maximum spike rate of afferent neurons increased sigmoidally with deflection velocity, with a linear range between 0.1 and 1.0 μm/ms. However, spike rate did not change when the cupula was deflected below 8 μm, regardless of deflection velocity. Our findings also reveal an unexpected sensitivity in the larval lateral line system: stimulation of a single neuromast could elicit a swimming response which increased in reliability with increasing deflection velocities. At high deflection velocities, we observed that lateral line evoked swimming has intermediate values of burst frequency and duty cycle that fall between electrically evoked and spontaneous swimming. An understanding of the sensory capabilities of a single neuromast will help to build a better picture of how stimuli are encoded at the systems level and ultimately translated into behavior. PMID:24966296

  20. Hydrogen sulfide determines HNO-induced stimulation of trigeminal afferents.

    PubMed

    Wild, Vanessa; Messlinger, Karl; Fischer, Michael J M

    2015-08-18

    Endogenous NO and hydrogen sulfide form HNO, which causes CGRP release via TRPA1 channel activation in sensory nerves. In the present study, stimulation of intact trigeminal afferent neuron preparations with NO donors, Na2S or both was analyzed by measuring CGRP release as an index of mass activation. Combined stimulation was able to activate all parts of the trigeminal system and acted synergistic compared to stimulation with both substances alone. To investigate the contribution of both substances, we varied their ratio and tracked intracellular calcium in isolated neurons. Our results demonstrate that hydrogen sulfide is the rate-limiting factor for HNO formation. CGRP has a key role in migraine pathophysiology and HNO formation at all sites of the trigeminal system should be considered for this novel means of activation.

  1. Inflammation increases the excitability of masseter muscle afferents.

    PubMed

    Harriott, A M; Dessem, D; Gold, M S

    2006-08-11

    Temporomandibular disorder is a major health problem associated with chronic orofacial pain in the masticatory muscles and/or temporomandibular joint. Evidence suggests that changes in primary afferents innervating the muscles of mastication may contribute to temporomandibular disorder. However, there has been little systematic study of the mechanisms controlling the excitability of these muscle afferents, nor their response to inflammation. In the present study, we tested the hypotheses that inflammation increases the excitability of sensory neurons innervating the masseter muscle of the rat and that the ionic mechanisms underlying these changes are unique to these neurons. We examined inflammation-induced changes in the excitability of trigeminal ganglia muscle neurons following intramuscular injections of complete Freund's adjuvant. Three days after complete Freund's adjuvant injection acutely dissociated, retrogradely labeled trigeminal ganglia neurons were studied using whole cell patch clamp techniques. Complete Freund's adjuvant-induced inflammation was associated with an increase in neuronal excitability marked by a significant decrease in rheobase and increase in the slope of the stimulus response function assessed with depolarizing current injection. The increase in excitability was associated with significant decreases in the rate of action potential fall and the duration of the action potential afterhyperpolarization. These changes in excitability and action potential waveform were associated with significant shifts in the voltage-dependence of activation and steady-state availability of voltage-gated K(+) current as well as significant decreases in the density of voltage-gated K(+) current subject to steady-state inactivation. These data suggest that K(+) channel subtypes may provide novel targets for the treatment of pain arising from inflamed muscle. These results also support the hypothesis that the underlying mechanisms of pain arising from

  2. Interleukin-1β sensitizes abdominal visceral afferents of cats to ischaemia and histamine

    PubMed Central

    Fu, Liang-Wu; Longhurst, John C

    1999-01-01

    Activation of abdominal splanchnic visceral afferents during mesenteric ischaemia induces visceral pain and evokes excitatory cardiovascular responses. Previous studies have shown that interleukin-1β (IL-1β) concentration is increased locally in tissues during ischaemia and reperfusion. Local administration of IL-1β sensitizes somatic afferents to mechanical, thermal and chemical stimulation. Therefore, we hypothesized that IL-1β stimulates or sensitizes splanchnic visceral afferents to ischaemia and to the action of chemical stimuli such as histamine. The concentration of IL-1β in mesenteric lymph and portal venous plasma in anaesthetized cats was measured with an enzyme-linked immunosorbent assay before, during and after 10 min of abdominal ischaemia. The level of IL-1β was significantly increased during ischaemia in lymph, but not in plasma. Discharge activity of single-unit abdominal visceral C fibre afferents was measured from the right thoracic sympathetic chain. Ischaemically sensitive C fibre afferents were identified according to their response to 5–10 min of abdominal ischaemia. Intra-arterial (i.a.) injection of a high dose of IL-1β (500 ng kg−1), but not of a lower dose (i.e. 15, 50 or 150 ng kg−1), stimulated most (six of seven) abdominal visceral afferents. IL-1β (15 ng kg−1, i.a.) significantly enhanced the increased activity of 11 of 13 C fibre afferents during 10 min of ischaemia. Conversely, an IL-1 type I receptor antagonist (IL-1ra, 1·5 μg kg−1, i.a.) significantly attenuated the increased activity in six of seven other C fibre afferents during ischaemia. IL-1β (15 ng kg−1, i.a.) significantly augmented the responses of 13 of 16 ischaemically sensitive abdominal afferents to histamine (5–10 μg kg−1, i.a.). Conversely, IL-1ra (1·5 μg kg−1, i.a.) significantly attenuated the responses of five of six other C fibre afferents to histamine. These data strongly suggest that stimulation of IL-1 type I receptors by IL-1

  3. Improved computer-assisted analysis of the global lymphatic network in human cervical tissues.

    PubMed

    Balsat, Cédric; Signolle, Nicolas; Goffin, Frédéric; Delbecque, Katty; Plancoulaine, Benoit; Sauthier, Philippe; Samouëlian, Vanessa; Béliard, Aude; Munaut, Carine; Foidart, Jean-Michel; Blacher, Silvia; Noël, Agnès; Kridelka, Frédéric

    2014-06-01

    Lymphatic dissemination is a key event in cervical cancer progression and related tumor lymphatic markers are viewed as promising prognostic factor of nodal extension. However, validating such parameters requires an objective characterization of the lymphatic vasculature. Here, we performed a global analysis of the lymphatic network using a new computerized method applied on whole uterine cervical digital images. Sixty-eight cases of cervical neoplasia (12 CIN3, 10 FIGO stage 1A and 46 stage IB1) and 10 cases of normal cervical tissue were reacted with antibodies raised against D2-40, D2-40/p16 and D2-40/Ki67. Immunostained structures were automatically detected on whole slides. The lymphatic vessel density (D2-40), proliferating lymphatic vessel density (D2-40/ki67) and spatial lymphatic distribution in respect to the adjacent epithelium were assessed from normal cervix to early cervical cancer and correlated with lymphovascular space invasion and lymph node status. Prominent lymphatic vessel density and proliferating lymphatic vessel density are detected under the transformation zone of benign cervix and no further increase is noted during cancer progression. Notably, a shift of lymphatic vessel distribution toward the neoplastic edges is detected. In IB1 cervical cancer, although intra- and peritumoral lymphatic vessel density are neither correlated with lymphovascular space invasion nor with lymph node metastasis, a specific spatial distribution with more lymphatic vessels in the vicinity of tumor edges is predictive of lymphatic dissemination. Herein, we provide a new computerized method suitable for an innovative detailed analysis of the lymphatic network. We show that the transformation zone of the benign cervix acts as a baseline lymphangiogenic niche before the initiation of neoplastic process. During cancer progression, this specific microenvironment is maintained with lymphatic vessels even in closer vicinity to tumor cells. PMID:24309324

  4. The dual role of tumor lymphatic vessels in dissemination of metastases and immune response development.

    PubMed

    Stachura, Joanna; Wachowska, Malgorzata; Kilarski, Witold W; Güç, Esra; Golab, Jakub; Muchowicz, Angelika

    2016-07-01

    Lymphatic vasculature plays a crucial role in the immune response, enabling transport of dendritic cells (DCs) and antigens (Ags) into the lymph nodes. Unfortunately, the lymphatic system has also a negative role in the progression of cancer diseases, by facilitating the metastatic spread of many carcinomas to the draining lymph nodes. The lymphatics can promote antitumor immune response as well as tumor tolerance. Here, we review the role of lymphatic endothelial cells (LECs) in tumor progression and immunity and mechanism of action in the newest anti-lymphatic therapies, including photodynamic therapy (PDT).

  5. Intestinal and peri-tumoral lymphatic endothelial cells are resistant to radiation-induced apoptosis

    SciTech Connect

    Sung, Hoon Ki; Morisada, Tohru; Cho, Chung-Hyun; Oike, Yuichi; Lee, Jayhun; Sung, Eon Ki; Chung, Jae Hoon; Suda, Toshio; Koh, Gou Young . E-mail: gykoh@kaist.ac.kr

    2006-06-30

    Radiation therapy is a widely used cancer treatment, but it is unable to completely block cancer metastasis. The lymphatic vasculature serves as the primary route for metastatic spread, but little is known about how lymphatic endothelial cells respond to radiation. Here, we show that lymphatic endothelial cells in the small intestine and peri-tumor areas are highly resistant to radiation injury, while blood vessel endothelial cells in the small intestine are relatively sensitive. Our results suggest the need for alternative therapeutic modalities that can block lymphatic endothelial cell survival, and thus disrupt the integrity of lymphatic vessels in peri-tumor areas.

  6. The dual role of tumor lymphatic vessels in dissemination of metastases and immune response development

    PubMed Central

    Stachura, Joanna; Wachowska, Malgorzata; Kilarski, Witold W.; Güç, Esra; Golab, Jakub; Muchowicz, Angelika

    2016-01-01

    ABSTRACT Lymphatic vasculature plays a crucial role in the immune response, enabling transport of dendritic cells (DCs) and antigens (Ags) into the lymph nodes. Unfortunately, the lymphatic system has also a negative role in the progression of cancer diseases, by facilitating the metastatic spread of many carcinomas to the draining lymph nodes. The lymphatics can promote antitumor immune response as well as tumor tolerance. Here, we review the role of lymphatic endothelial cells (LECs) in tumor progression and immunity and mechanism of action in the newest anti-lymphatic therapies, including photodynamic therapy (PDT).

  7. The dual role of tumor lymphatic vessels in dissemination of metastases and immune response development

    PubMed Central

    Stachura, Joanna; Wachowska, Malgorzata; Kilarski, Witold W.; Güç, Esra; Golab, Jakub; Muchowicz, Angelika

    2016-01-01

    ABSTRACT Lymphatic vasculature plays a crucial role in the immune response, enabling transport of dendritic cells (DCs) and antigens (Ags) into the lymph nodes. Unfortunately, the lymphatic system has also a negative role in the progression of cancer diseases, by facilitating the metastatic spread of many carcinomas to the draining lymph nodes. The lymphatics can promote antitumor immune response as well as tumor tolerance. Here, we review the role of lymphatic endothelial cells (LECs) in tumor progression and immunity and mechanism of action in the newest anti-lymphatic therapies, including photodynamic therapy (PDT). PMID:27622039

  8. The dual role of tumor lymphatic vessels in dissemination of metastases and immune response development.

    PubMed

    Stachura, Joanna; Wachowska, Malgorzata; Kilarski, Witold W; Güç, Esra; Golab, Jakub; Muchowicz, Angelika

    2016-07-01

    Lymphatic vasculature plays a crucial role in the immune response, enabling transport of dendritic cells (DCs) and antigens (Ags) into the lymph nodes. Unfortunately, the lymphatic system has also a negative role in the progression of cancer diseases, by facilitating the metastatic spread of many carcinomas to the draining lymph nodes. The lymphatics can promote antitumor immune response as well as tumor tolerance. Here, we review the role of lymphatic endothelial cells (LECs) in tumor progression and immunity and mechanism of action in the newest anti-lymphatic therapies, including photodynamic therapy (PDT). PMID:27622039

  9. The Socioeconomic Impact of Lymphatic Filariasis in Tropical Countries

    ERIC Educational Resources Information Center

    Nwoke, Bertram Ekejiuba Bright; Nwoke, Eunice Anyalewechi; Dozie, Ikechukwu Nosike Simplicius

    2007-01-01

    Lymphatic filariasis (LF) is an endemic parasitic disease and a major cause of acute and chronic morbidity and incapacitation with devastating public health and socio-economic consequences. It exacerbates poor conditions of afflicted persons and endemic communities through reduced or lost labour supply and productivity. Stigmatisation and…

  10. Lymphatic vessels in the development of tissue and organ rejection.

    PubMed

    Hos, Deniz; Cursiefen, Claus

    2014-01-01

    The lymphatic vascular system-amongst other tasks-is critically involved in the regulation of adaptive immune responses as it provides an important route for APC trafficking to secondary lymphatic organs. In this context, the cornea, which is the transparent and physiologically avascular "windscreen" of the eye, has served as an excellent in vivo model to study the role of the blood and lymphatic vasculature in mediating allogenic immune responses after transplantation. Especially the mouse model of high-risk corneal transplantation, where corneal avascularity is abolished by a severe inflammatory stimulus prior to keratoplasty, allows for comparison to other transplantations performed in primarily vascularized tissues and solid organs. Using this model, we recently demonstrated that especially lymphatic vessels, but not blood vessels, define the high-risk status of vascularized corneas and that anti(lymph)angiogenic treatment significantly promotes corneal allograft survival. Since evidence for lymphangiogenesis and its potential association with graft rejection is nowadays also present in solid organ transplantation, studies are currently addressing the potential benefits of anti(lymph)angiogenic treatment as a novel therapeutic concept also in solid organ grafting with promising initial results.

  11. Monitoring contractile dermal lymphatic activity following uniaxial mechanical loading.

    PubMed

    Gray, R J; Worsley, P R; Voegeli, D; Bader, D L

    2016-09-01

    It is proposed that direct mechanical loading can impair dermal lymphatic function, contributing to the causal pathway of pressure ulcers. The present study aims to investigate the effects of loading on human dermal lymphatic vessels. Ten participants were recruited with ages ranging from 24 to 61 years. Participants had intradermal Indocyanine Green injections administrated between left finger digits. Fluorescence was imaged for 5min sequences with an infra-red camera prior to lymph vessel loading, immediately after axial loading (60mmHg) and following a recovery period. Image processing was employed to defined transient lymph packets and compare lymph function between each test phase. The results revealed that between 1-8 transient events (median=4) occurred at baseline, with a median velocity of 8.1mm/sec (range 4.1-20.1mm/sec). Immediately post-loading, there was a significant (p<0.05) reduction in velocity (median=6.4, range 2.2-13.5mm/sec), although the number of transient lymph packages varied between participants. During the recovery period the number (range 1-7) and velocity (recovery median=9.6mm/sec) of transient packets were largely restored to basal values. The present study revealed that some individuals present with impaired dermal lymphatic function immediately after uniaxial mechanical loading. More research is needed to investigate the effects of pressure and shear on lymphatic vessel patency. PMID:27245749

  12. Dermal lymphatic dilation in a mouse model of alopecia areata.

    PubMed

    Sundberg, John P; Pratt, C Herbert; Silva, Kathleen A; Kennedy, Victoria E; Stearns, Timothy M; Sundberg, Beth A; King, Lloyd E; HogenEsch, Harm

    2016-04-01

    Mouse models of various types of inflammatory skin disease are often accompanied by increased dermal angiogenesis. The C3H/HeJ inbred strain spontaneously develops alopecia areata (AA), a cell mediated autoimmune disorder that can be controllably expanded using full thickness skin grafts to young unaffected mice. This provides a reproducible and progressive model for AA in which the vascularization of the skin can be examined. Mice receiving skin grafts from AA or normal mice were evaluated at 5, 10, 15, and 20 weeks after engraftment. Lymphatics are often overlooked as they are small slit-like structures above the hair follicle that resemble artifact-like separation of collagen bundles with some fixatives. Lymphatics are easily detected using lymphatic vessel endothelial hyaluronan receptor 1 (LYVE1) by immunohistochemistry to label their endothelial cells. Using LYVE1, there were no changes in distribution or numbers of lymphatics although they were more prominent (dilated) in the mice with AA. Lyve1 transcripts were not significantly upregulated except at 10 weeks after skin grafting when clinical signs of AA first become apparent. Other genes involved with vascular growth and dilation or movement of immune cells were dysregulated, mostly upregulated. These findings emphasize aspects of AA not commonly considered and provide potential targets for therapeutic intervention.

  13. The meningeal lymphatic system: a route for HIV brain migration?

    PubMed

    Lamers, Susanna L; Rose, Rebecca; Ndhlovu, Lishomwa C; Nolan, David J; Salemi, Marco; Maidji, Ekaterina; Stoddart, Cheryl A; McGrath, Michael S

    2016-06-01

    Two innovative studies recently identified functional lymphatic structures in the meninges that may influence the development of HIV-associated neurological disorders (HAND). Until now, blood vessels were assumed to be the sole transport system by which HIV-infected monocytes entered the brain by bypassing a potentially hostile blood-brain barrier through inflammatory-mediated semi-permeability. A cascade of specific chemokine signals promote monocyte migration from blood vessels to surrounding brain tissues via a well-supported endothelium, where the cells differentiate into tissue macrophages capable of productive HIV infection. Lymphatic vessels on the other hand are more loosely organized than blood vessels. They absorb interstitial fluid from bodily tissues where HIV may persist and exchange a variety of immune cells (CD4(+) T cells, monocytes, macrophages, and dendritic cells) with surrounding tissues through discontinuous endothelial junctions. We propose that the newly discovered meningeal lymphatics are key to HIV migration among viral reservoirs and brain tissue during periods of undetectable plasma viral loads due to suppressive combinational antiretroviral therapy, thus redefining the migration process in terms of a blood-lymphatic transport system.

  14. Dermal lymphatic dilation in a mouse model of alopecia areata.

    PubMed

    Sundberg, John P; Pratt, C Herbert; Silva, Kathleen A; Kennedy, Victoria E; Stearns, Timothy M; Sundberg, Beth A; King, Lloyd E; HogenEsch, Harm

    2016-04-01

    Mouse models of various types of inflammatory skin disease are often accompanied by increased dermal angiogenesis. The C3H/HeJ inbred strain spontaneously develops alopecia areata (AA), a cell mediated autoimmune disorder that can be controllably expanded using full thickness skin grafts to young unaffected mice. This provides a reproducible and progressive model for AA in which the vascularization of the skin can be examined. Mice receiving skin grafts from AA or normal mice were evaluated at 5, 10, 15, and 20 weeks after engraftment. Lymphatics are often overlooked as they are small slit-like structures above the hair follicle that resemble artifact-like separation of collagen bundles with some fixatives. Lymphatics are easily detected using lymphatic vessel endothelial hyaluronan receptor 1 (LYVE1) by immunohistochemistry to label their endothelial cells. Using LYVE1, there were no changes in distribution or numbers of lymphatics although they were more prominent (dilated) in the mice with AA. Lyve1 transcripts were not significantly upregulated except at 10 weeks after skin grafting when clinical signs of AA first become apparent. Other genes involved with vascular growth and dilation or movement of immune cells were dysregulated, mostly upregulated. These findings emphasize aspects of AA not commonly considered and provide potential targets for therapeutic intervention. PMID:26960166

  15. Expression of Lymphatic Markers in the Adult Rat Spinal Cord

    PubMed Central

    Kaser-Eichberger, Alexandra; Schroedl, Falk; Bieler, Lara; Trost, Andrea; Bogner, Barbara; Runge, Christian; Tempfer, Herbert; Zaunmair, Pia; Kreutzer, Christina; Traweger, Andreas; Reitsamer, Herbert A.; Couillard-Despres, Sebastien

    2016-01-01

    Under physiological conditions, lymphatic vessels are thought to be absent from the central nervous system (CNS), although they are widely distributed within the rest of the body. Recent work in the eye, i.e., another organ regarded as alymphatic, revealed numerous cells expressing lymphatic markers. As the latter can be involved in the response to pathological conditions, we addressed the presence of cells expressing lymphatic markers within the spinal cord by immunohistochemistry. Spinal cord of young adult Fisher rats was scrutinized for the co-expression of the lymphatic markers PROX1 and LYVE-1 with the cell type markers Iba1, CD68, PGP9.5, OLIG2. Rat skin served as positive control for the lymphatic markers. PROX1-immunoreactivity was detected in many nuclei throughout the spinal cord white and gray matter. These nuclei showed no association with LYVE-1. Expression of LYVE-1 could only be detected in cells at the spinal cord surface and in cells closely associated with blood vessels. These cells were found to co-express Iba1, a macrophage and microglia marker. Further, double labeling experiments using CD68, another marker found in microglia and macrophages, also displayed co-localization in the Iba1+ cells located at the spinal cord surface and those apposed to blood vessels. On the other hand, PROX1-expressing cells found in the parenchyma were lacking Iba1 or PGP9.5, but a significant fraction of those cells showed co-expression of the oligodendrocyte lineage marker OLIG2. Intriguingly, following spinal cord injury, LYVE-1-expressing cells assembled and reorganized into putative pre-vessel structures. As expected, the rat skin used as positive controls revealed classical lymphatic vessels, displaying PROX1+ nuclei surrounded by LYVE-1-immunoreactivity. Classical lymphatics were not detected in adult rat spinal cord. Nevertheless, numerous cells expressing either LYVE-1 or PROX1 were identified. Based on their localization and overlapping expression with

  16. Expression of Lymphatic Markers in the Adult Rat Spinal Cord.

    PubMed

    Kaser-Eichberger, Alexandra; Schroedl, Falk; Bieler, Lara; Trost, Andrea; Bogner, Barbara; Runge, Christian; Tempfer, Herbert; Zaunmair, Pia; Kreutzer, Christina; Traweger, Andreas; Reitsamer, Herbert A; Couillard-Despres, Sebastien

    2016-01-01

    Under physiological conditions, lymphatic vessels are thought to be absent from the central nervous system (CNS), although they are widely distributed within the rest of the body. Recent work in the eye, i.e., another organ regarded as alymphatic, revealed numerous cells expressing lymphatic markers. As the latter can be involved in the response to pathological conditions, we addressed the presence of cells expressing lymphatic markers within the spinal cord by immunohistochemistry. Spinal cord of young adult Fisher rats was scrutinized for the co-expression of the lymphatic markers PROX1 and LYVE-1 with the cell type markers Iba1, CD68, PGP9.5, OLIG2. Rat skin served as positive control for the lymphatic markers. PROX1-immunoreactivity was detected in many nuclei throughout the spinal cord white and gray matter. These nuclei showed no association with LYVE-1. Expression of LYVE-1 could only be detected in cells at the spinal cord surface and in cells closely associated with blood vessels. These cells were found to co-express Iba1, a macrophage and microglia marker. Further, double labeling experiments using CD68, another marker found in microglia and macrophages, also displayed co-localization in the Iba1+ cells located at the spinal cord surface and those apposed to blood vessels. On the other hand, PROX1-expressing cells found in the parenchyma were lacking Iba1 or PGP9.5, but a significant fraction of those cells showed co-expression of the oligodendrocyte lineage marker OLIG2. Intriguingly, following spinal cord injury, LYVE-1-expressing cells assembled and reorganized into putative pre-vessel structures. As expected, the rat skin used as positive controls revealed classical lymphatic vessels, displaying PROX1+ nuclei surrounded by LYVE-1-immunoreactivity. Classical lymphatics were not detected in adult rat spinal cord. Nevertheless, numerous cells expressing either LYVE-1 or PROX1 were identified. Based on their localization and overlapping expression with

  17. Hair cell tufts and afferent innervation of the bullfrog crista ampullaris

    NASA Technical Reports Server (NTRS)

    Myers, Steven F.; Lewis, Edwin R.

    1990-01-01

    Within the bullfrog semicircular canal crista, hair cell tuft types were defined and mapped with the aid of scanning electron microscopy. Dye-filled planar afferent axons had mean distal axonal diameters of 1.6-4.9 microns, highly branched arbors, and contacted 11-24 hair cells. Dye-filled isthmus afferent axons had mean distal axonal diameters of 1.8-7.9 microns, with either small or large field arbors contacting 4-9 or 25-31 hair cells. The estimated mean number of contacts per innervated hair cell was 2.2 for planar and 1.3 for isthmus afferent neurons. Data on evoked afferent responses were available only for isthmus units that were observed to respond to our microrotational stimuli. Of 21 such afferent neurons, eight were successfully dye-filled. Within this sample, high-gain units had large field arbors and lower-gain units had small field arbors. The sensitivity of each afferent neuron was analyzed in terms of noise equivalent input (NEI), the stimulus amplitude for which the afferent response amplitude is just equivalent to the rms deviation of the instantaneous spike rate. NEI for isthmus units varied from 0.63 to 8.2 deg/s; the mean was 3.2 deg/s.

  18. Novel Afferent Terminal Structure in the Crista Ampullaris of the Goldfish, Carassius auratus

    NASA Technical Reports Server (NTRS)

    Lanford, Pamela J.; Popper, Arthur N.

    1996-01-01

    Using transmission electron microscopy, we have identified a new type of afferent terminal structure in the crista ampullaris of the goldfish Carassius auratus. In addition to the bouton-type afferent terminals previously described in the ear of this species, the crista also contained enlarged afferent terminals that enveloped a portion of the basolateral hair cell membrane. The hair cell membrane was evaginated and protruded into the afferent terminal in a glove-and-finger configuration. The membranes of the two cells were regularly aligned in the protruded region of the contact and had a distinct symmetrical electron density. The electron-dense profiles of these contacts were easily identified and were present in every crista sampled. In some cases, efferent terminals synapsed onto the afferents at a point where the hair cell protruded into the terminal. The ultrastructural similarities of the goldfish crista afferents to calyx afferents found in amniotes (birds, reptiles, and mammals) are discussed. The results of the study support the hypothesis that structural variation in the vertebrate inner ear may have evolved much earlier in evolution than previously supposed.

  19. Organization of afferents to the striatopallidal systems in the fire-bellied toad Bombina orientalis.

    PubMed

    Ramsay, Zachary J; Laberge, Frédéric

    2014-11-01

    The cerebral hemispheres of amphibians display paired dorsal and ventral striatum (commonly referred to as striatum proper and nucleus accumbens, respectively). Each striatal region is proposed to be closely associated with a pallidal structure located caudal to it to form a striatopallidal system. In the present study, afferents to the dorsal and ventral striatopallidal systems of the fire-bellied toad (Bombina orientalis) were investigated using the neuronal tracer biocytin. A quantitative analysis of the topographical distribution of afferent neurons from the thalamus and posterior tubercle/ventral tegmentum was emphasised. The main results show that inputs to the two striatopallidal systems originate from distinct dorsal thalamic nuclei, with dorsal and ventral striatopallidal afferent neurons favouring strongly the lateral/central and anterior thalamic nuclei, respectively. However, afferent neuron distribution in the dorsal thalamus does not differ in the rostrocaudal axis of the brain. Afferent neurons from the posterior tubercle and ventral tegmentum, on the other hand, are organised topographically along the rostrocaudal axis. About 85 % of afferent neurons to the dorsal striatopallidal system are located rostrally in the posterior tubercle, while 75 % of afferent neurons to the ventral striatopallidal system are found more caudally in the ventral tegmentum. This difference is statistically significant and confirms the presence of distinct mesostriatal pathways in an amphibian. These findings demonstrate that an amphibian brain displays striatopallidal systems integrating parallel streams of sensory information potentially under the influence of distinct ascending mesostriatal pathways.

  20. Technetium-99m HIDA hepatobiliary scanning in evaluation of afferent loop syndrome

    SciTech Connect

    Sivelli, R.; Farinon, A.M.; Sianesi, M.; Percudani, M.; Ugolotti, G.; Calbiani, B.

    1984-08-01

    A study of 118 patients, operated on with Billroth II gastrectomy for peptic disease and affected by postgastrectomy syndromes, was carried out. Fifty patients were investigated by means of technetium-99m HIDA hepatobiliary scanning. In 18 patients, in whom an afferent loop syndrome was clinically suspected, hepatobiliary scanning demonstrated an altered afferent loop emptying in 8 and atonic distension of the gallbladder without afferent loop motility changes in 10. Among the patients in the first group, four were treated with a biliary diversion surgical procedure and in the second group, two patients underwent cholecystectomy. Our findings indicate that biliary vomiting, right upper abdominal pain pyrosis, and biliary diarrhea in Billroth II gastrectomized patients are not always pathognomonic symptoms of afferent loop syndrome. Technetium-99m HIDA hepatobiliary scanning represents the only diagnostic means of afferent loop syndrome definition. A differential diagnosis of abnormal afferent loop emptying and gallbladder dyskinesia is necessary for the management planning of these patients, and furthermore, when a surgical treatment is required, biliary diversion with Roux-Y anastomosis or Braun's biliary diversion seems the treatment of choice for afferent loop syndrome, whereas cholecystectomy represents the best procedure for atonic distension of the gallbladder.

  1. Distribution of presumptive chemosensory afferents with FMRFamide- or substance P-like immunoreactivity in decapod crustaceans.

    PubMed

    Schmidt, M

    1997-01-23

    In five species of decapod crustaceans--Cherax destructor (crayfish), Carcinus maenas (crab), Homarus americanus (clawed lobster), Eriocheir sinensis (crab), Macrobrachium rosenbergii (shrimp)--immunocytochemical stainings revealed the presence of sensory afferents with FMRFamide-like immunoreactivity in the central nervous system. These afferents were extremely thin, very numerous, and innervated all sensory neuropils except the optic and olfactory lobes. In their target neuropils they gave rise to condensed net- or ball-like terminal structures. Only in Homarus americanus but not in any other studied species immunocytochemistry revealed a separate, non-overlapping class of sensory afferents with substance P-like immunoreactivity. Also the afferents with substance P-like immunoreactivity were very thin and numerous, innervated all sensory neuropils except optic and olfactory lobes, and gave rise to condensed terminal structures. From their morphological characteristics it can be concluded that likely both classes of afferents are chemosensory. The substance P-like immunoreactivity suggests a link with the nociceptor afferents of vertebrates, with which both classes of afferents share several other morphological features.

  2. The relationship between the size of a muscle afferent volley and the cerebral potential it produces.

    PubMed Central

    Gandevia, S; Burke, D; McKeon, B

    1982-01-01

    This study examined the relationship between the size of an afferent neural input produced by electrical stimulation of the posterior tibial nerve at the ankle and the size of the early components of the evoked cerebral potential. For five of six subjects the first peak of the afferent neural volley recorded in the popliteal fossa was uncontaminated by either motor efferents or cutaneous afferents. This was established by measuring the conduction times of motor fibres in the posterior tibial nerve and cutaneous fibres in the sural and posterior tibial nerves over the ankle to popliteal fossa segment. It is likely therefore that the first peak of the afferent volley contained predominantly, if not exclusively, activity in rapidly conducting afferents from the small muscles of the foot. The size of the two earliest components of the cerebral potential did not increase in direct proportion to the size of the afferent volley which produced it. The early components of the cerebral potential reached a maximum when the responsible muscle afferent volley was less than 50% of its maximum. PMID:6290605

  3. Smooth muscle–endothelial cell communication activates Reelin signaling and regulates lymphatic vessel formation

    PubMed Central

    Lutter, Sophie; Xie, Sherry; Tatin, Florence

    2012-01-01

    Active lymph transport relies on smooth muscle cell (SMC) contractions around collecting lymphatic vessels, yet regulation of lymphatic vessel wall assembly and lymphatic pumping are poorly understood. Here, we identify Reelin, an extracellular matrix glycoprotein previously implicated in central nervous system development, as an important regulator of lymphatic vascular development. Reelin-deficient mice showed abnormal collecting lymphatic vessels, characterized by a reduced number of SMCs, abnormal expression of lymphatic capillary marker lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1), and impaired function. Furthermore, we show that SMC recruitment to lymphatic vessels stimulated release and proteolytic processing of endothelium-derived Reelin. Lymphatic endothelial cells in turn responded to Reelin by up-regulating monocyte chemotactic protein 1 (MCP1) expression, which suggests an autocrine mechanism for Reelin-mediated control of endothelial factor expression upstream of SMC recruitment. These results uncover a mechanism by which Reelin signaling is activated by communication between the two cell types of the collecting lymphatic vessels—smooth muscle and endothelial cells—and highlight a hitherto unrecognized and important function for SMCs in lymphatic vessel morphogenesis and function. PMID:22665518

  4. Decline of lymphatic vessel density and function in murine skin during aging.

    PubMed

    Karaman, Sinem; Buschle, Dorina; Luciani, Paola; Leroux, Jean-Christophe; Detmar, Michael; Proulx, Steven T

    2015-10-01

    Lymphatic vessels play important roles in the pathogenesis of many conditions that have an increased prevalence in the elderly population. However, the effects of the aging process on the lymphatic system are still relatively unknown. We have applied non-invasive imaging and whole-mount staining techniques to assess the lymphatic vessel function and morphology in three different age groups of mice: 2 months (young), 7 months (middle-aged), and 18 months (aged). We first developed and validated a new method to quantify lymphatic clearance from mouse ear skin, using a lymphatic-specific near-infrared tracer. Using this method, we found that there is a prominent decrease in lymphatic vessel function during aging since the lymphatic clearance was significantly delayed in aged mice. This loss of function correlated with a decreased lymphatic vessel density and a reduced lymphatic network complexity in the skin of aged mice as compared to younger controls. The blood vascular leakage in the skin was slightly increased in the aged mice, indicating that the decreased lymphatic function was not caused by a reduced capillary filtration in aged skin. The decreased function of lymphatic vessels with aging might have implications for the pathogenesis of a number of aging-related diseases.

  5. Modulation of vagal afferent excitation and reduction of food intake by leptin and cholecystokinin.

    PubMed

    Peters, James H; Simasko, Steven M; Ritter, Robert C

    2006-11-30

    The gut-peptide, cholecystokinin (CCK), reduces food intake by acting at CCK-1 receptors on vagal afferent neurons, whereas the feeding effects of the adipokine hormone, leptin, are associated primarily with its action on receptors (ObRb) in the hypothalamus. Recently, however, ObRb mRNA has been reported in vagal afferent neurons, some of which also express CCK-1 receptor, suggesting that leptin, alone or in cooperation with CCK, might activate vagal afferent neurons, and influence food intake via a vagal route. To evaluate these possibilities we have been examining the cellular and behavioral effects of leptin and CCK on vagal afferent neurons. In cultured vagal afferent neurons leptin and CCK evoked short latency, transient depolarizations, often leading to action potentials, and increases in cytosolic calcium. There was a much higher prevalence of CCK and leptin sensitivity amongst cultured vagal afferent neurons that innervate stomach or duodenum than there was in the overall vagal afferent population. Furthermore, almost all leptin-responsive gastric and duodenal vagal afferents also were sensitive to CCK. Leptin, infused into the upper GI tract arterial supply, reduced meal size, and enhanced satiation evoked by CCK. These results indicate that vagal afferent neurons are activated by leptin, and that this activation is likely to participate in meal termination, perhaps by enhancing vagal sensitivity to CCK. Our findings are consistent with the view that leptin and CCK exert their influence on food intake by accessing multiple neural systems (viscerosensory, motivational, affective and motor) at multiple points along the neuroaxis. PMID:16872644

  6. Estradiol alters the chemosensitive cardiac afferent reflex in female rats by augmenting sympathoinhibition and attenuating sympathoexcitation.

    PubMed

    Pinkham, Maximilian I; Barrett, Carolyn J

    2015-06-01

    The chemosensitive cardiac vagal and sympathetic afferent reflexes are implicated in driving pathophysiological changes in sympathetic nerve activity (SNA) in cardiovascular disease states. This study investigated the impact of sex and ovarian hormones on the chemosensitive cardiac afferent reflex. Experiments were performed in anaesthetized, sinoaortic baroreceptor denervated male, female and ovariectomized female (OVX) Wistar rats with either intact cardiac innervation or bilateral vagotomy. To investigate the chemosensitive cardiac afferent reflexes renal SNA, heart rate (HR) and arterial pressure (AP) were recorded before and following application of capsaicin onto the epicardial surface of the left ventricle. Compared to males, ovary-intact females displayed similar cardiac afferent reflex mediated changes in renal SNA albeit with a reduced maximum sympathetic reflex driven increase in renal SNA. In females, ovariectomy significantly attenuated the cardiac vagal afferent reflex mediated inhibition of renal SNA (renal SNA decreased 2 ± 17% in OVX versus -50 ± 4% in ovary-intact females, P < 0.05) and augmented cardiac sympathetic afferent reflex mediated sympathoexcitation (renal SNA increased 91 ± 11% in OVX vs 62 ± 9% in ovary-intact females, P < 0.05) so that overall increases in reflex driven sympathoexcitation were significantly enhanced. Chronic estradiol replacement, but not progesterone replacement, begun at time of ovariectomy restored cardiac afferent reflex responses to be similar as ovary-intact females. Vagal denervation eliminated all group differences. The current findings show ovariectomy in female rats, mimicking menopause in women, results in greater chemosensitive cardiac afferent reflex driven sympathoexcitation and does so, at least partly, via the loss of estradiols actions on the cardiac vagal afferent reflex pathway.

  7. A novel method of selective ablation of afferent renal nerves by periaxonal application of capsaicin

    PubMed Central

    Foss, Jason D.; Wainford, Richard D.; Engeland, William C.; Fink, Gregory D.

    2014-01-01

    Renal denervation has been shown to lower arterial pressure in some hypertensive patients, yet it remains unclear whether this is due to ablation of afferent or efferent renal nerves. To investigate the role of afferent renal nerves in arterial pressure regulation, previous studies have used methods that disrupt both renal and nonrenal afferent signaling. The present study was conducted to develop and validate a technique for selective ablation of afferent renal nerves that does not disrupt other afferent pathways. To do this, we adapted a technique for sensory denervation of the adrenal gland by topical application of capsaicin and tested the hypothesis that exposure of the renal nerves to capsaicin (renal-CAP) causes ablation of afferent but not efferent renal nerves. Renal-CAP had no effect on renal content of the efferent nerve markers tyrosine hydroxylase and norepinephrine; however, the afferent nerve marker, calcitonin gene-related peptide was largely depleted from the kidney 10 days after intervention, but returned to roughly half of control levels by 7 wk postintervention. Moreover, renal-CAP abolished the cardiovascular responses to acute pharmacological stimulation of afferent renal nerves. Renal-CAP rats showed normal weight gain, as well as cardiovascular and fluid balance regulation during dietary sodium loading. To some extent, renal-CAP did blunt the bradycardic response and increase the dipsogenic response to increased salt intake. Lastly, renal-CAP significantly attenuated the development of deoxycorticosterone acetate-salt hypertension. These results demonstrate that renal-CAP effectively causes selective ablation of afferent renal nerves in rats. PMID:25411365

  8. New concept for the prevention and treatment of metastatic lymph nodes using chemotherapy administered via the lymphatic network

    PubMed Central

    Kodama, Tetsuya; Matsuki, Daisuke; Tada, Asuka; Takeda, Kazu; Mori, Shiro

    2016-01-01

    Intravenous chemotherapy has poor access to metastatic lymph nodes (LNs) and is limited by short-lived drug concentrations. Here, we describe the administration of chemotherapy via the lymphatic network as a new concept for the prevention and treatment of metastatic LNs. A metastatic LN can be treated by the injection of drugs into an upstream LN, either the sentinel LN (SLN) or another upstream LN. In a mouse model, tumor cells were inoculated into the subiliac LN (SiLN) to induce metastasis to the proper axillary LN (PALN). Two routes were used for drug delivery to the PALN, namely from the SiLN and from the accessory axillary LN (AALN). We found that tumor masses were formed in lymphatic vessels between the SiLN and PALN. The flow of fluorescent solution injected into the SiLN towards the PALN decreased with tumor mass formation. Delivery from the AALN (free of metastatic tumor cells) to the PALN was identified as an alternative route. Intranodal injection can deliver high concentrations of drugs to secondary metastatic LNs. The study advocates a new concept for the prevention and treatment of metastatic lymph nodes whereby drugs injected into upstream lymph nodes can reach metastatic lymph nodes via the lymphatic network. PMID:27581921

  9. New concept for the prevention and treatment of metastatic lymph nodes using chemotherapy administered via the lymphatic network.

    PubMed

    Kodama, Tetsuya; Matsuki, Daisuke; Tada, Asuka; Takeda, Kazu; Mori, Shiro

    2016-01-01

    Intravenous chemotherapy has poor access to metastatic lymph nodes (LNs) and is limited by short-lived drug concentrations. Here, we describe the administration of chemotherapy via the lymphatic network as a new concept for the prevention and treatment of metastatic LNs. A metastatic LN can be treated by the injection of drugs into an upstream LN, either the sentinel LN (SLN) or another upstream LN. In a mouse model, tumor cells were inoculated into the subiliac LN (SiLN) to induce metastasis to the proper axillary LN (PALN). Two routes were used for drug delivery to the PALN, namely from the SiLN and from the accessory axillary LN (AALN). We found that tumor masses were formed in lymphatic vessels between the SiLN and PALN. The flow of fluorescent solution injected into the SiLN towards the PALN decreased with tumor mass formation. Delivery from the AALN (free of metastatic tumor cells) to the PALN was identified as an alternative route. Intranodal injection can deliver high concentrations of drugs to secondary metastatic LNs. The study advocates a new concept for the prevention and treatment of metastatic lymph nodes whereby drugs injected into upstream lymph nodes can reach metastatic lymph nodes via the lymphatic network. PMID:27581921

  10. Platelet interaction with lymphatics aggravates intestinal inflammation by suppressing lymphangiogenesis.

    PubMed

    Sato, Hirokazu; Higashiyama, Masaaki; Hozumi, Hideaki; Sato, Shingo; Furuhashi, Hirotaka; Takajo, Takeshi; Maruta, Koji; Yasutake, Yuichi; Narimatsu, Kazuyuki; Yoshikawa, Kenichi; Kurihara, Chie; Okada, Yoshikiyo; Watanabe, Chikako; Komoto, Shunsuke; Tomita, Kengo; Nagao, Shigeaki; Miura, Soichiro; Hokari, Ryota

    2016-08-01

    Lymphatic failure is a histopathological feature of inflammatory bowel disease (IBD). Recent studies show that interaction between platelets and podoplanin on lymphatic endothelial cells (LECs) suppresses lymphangiogenesis. We aimed to investigate the role of platelets in the inflammatory process of colitis, which is likely to be through modulation of lymphangiogenesis. Lymphangiogenesis in colonic mucosal specimens from patients with IBD was investigated by studying mRNA expression of lymphangiogenic factors and histologically by examining lymphatic vessel (LV) densities. Involvement of lymphangiogenesis in intestinal inflammation was studied by administering VEGF-receptor 3 (VEGF-R3) inhibitors to the mouse model of colitis using dextran sulfate sodium and evaluating platelet migration to LVs. The inhibitory effect of platelets on lymphangiogenesis was investigated in vivo by administering antiplatelet antibody to the colitis mouse model and in vitro by coculturing platelets with lymphatic endothelial cells. Although mRNA expressions of lymphangiogenic factors such as VEGF-R3 and podoplanin were significantly increased in the inflamed mucosa of patients with IBD compared with those with quiescent mucosa, there was no difference in LV density between them. In the colitis model, VEGF-R3 inhibition resulted in aggravated colitis, decreased lymphatic density, and increased platelet migration to LVs. Administration of an antiplatelet antibody increased LV densities and significantly ameliorated colitis. Coculture with platelets inhibited proliferation of LECs in vitro. Our data suggest that despite elevated lymphangiogenic factors during colonic inflammation, platelet migration to LVs resulted in suppressed lymphangiogenesis, leading to aggravation of colitis by blocking the clearance of inflammatory cells. Modulating the interaction between platelets and LVs could be a new therapeutic means for treating IBD.

  11. Lymphatic Mapping in the Treatment of Chronic Seroma: A Case Series

    PubMed Central

    Aliano, Kristen; Stavrides, Steven; Davenport, Thomas

    2015-01-01

    Objective: Seromas or lymphoceles are common postoperative complications. This series presents 3 patients with lower extremity seromas refractory to treatment that required lymphatic mapping and lymphatic ligation for closure, and in 1 case, diagnosis. Methods: Lymphatic mapping procedure consisted of intraoperative injection of subcutaneous tissue with methylene blue distal to the seroma with observation of dye effluence from transected or injured lymphatics draining into area of seroma. Results: In 2 patients, methylene blue dye absorption into lymphatic vessels allowed for optimized visual identification of lymphatic leak and contrast against surrounding tissues. In the third patient, where no lymphocele leak was found, the study was diagnostic and helped to find an alternate etiology for the recurrent seroma. Conclusion: Lymphatic mapping with methylene blue dye is an effective tool in the evaluation and diagnosis of chronic seroma. PMID:25848444

  12. Efficient Assessment of Developmental, Surgical and Pathological Lymphangiogenesis Using a Lymphatic Reporter Mouse and Its Embryonic Stem Cells

    PubMed Central

    Jung, Wonhyuek; Seong, Young Jin; Park, Eunkyung; Bramos, Athanasios; Kim, Kyu Eui; Lee, Sunju; Daghlian, George; Seo, Jung In; Choi, Inho; Choi, In-Seon; Koh, Chester J.; Kobielak, Agnieszka; Ying, Qi-Long; Johnson, Maxwell; Gardner, Daniel; Wong, Alex K.; Choi, Dongwon; Hong, Young-Kwon

    2016-01-01

    Several lymphatic reporter mouse lines have recently been developed to significantly improve imaging of lymphatic vessels. Nonetheless, the usage of direct visualization of lymphatic vessels has not been fully explored and documented. Here, we characterized a new Prox1-tdTomato transgenic lymphatic reporter mouse line, and demonstrated how this animal tool enables the researchers to efficiently assess developmental, surgical and pathological lymphangiogenesis by direct visualization of lymphatic vessels. Moreover, we have derived embryonic stem cells from this reporter line, and successfully differentiated them into lymphatic vessels in vivo. In conclusion, these experimental tools and techniques will help advance lymphatic research. PMID:27280889

  13. Enterolith Causing Afferent Loop Obstruction: A Case Report and Literature Review

    SciTech Connect

    Lee, Michael C.; Bui, James T.; Knuttinen, M-Grace; Gaba, Ron C.; Scott Helton, W.; Owens, Charles A.

    2009-09-15

    Enterolith formation is a rare cause of afferent limb obstruction following Billroth II gastrectomy and Roux-en-Y hepaticojejunostomy surgery. A case of ascending cholangitis caused by an enterolith incarcerated in the afferent loop of a 15-year-old Roux-en-Y hepaticojejunostomy was emergently decompressed under direct ultrasound guidance prior to surgery. This is the thirteenth reported case of an enterolith causing afferent loop obstruction. A discussion of our management approach and a review of the relevant literature are presented.

  14. Vascular endothelial growth factor receptor-2 promotes the development of the lymphatic vasculature.

    PubMed

    Dellinger, Michael T; Meadows, Stryder M; Wynne, Katherine; Cleaver, Ondine; Brekken, Rolf A

    2013-01-01

    Vascular endothelial growth factor receptor 2 (VEGFR2) is highly expressed by lymphatic endothelial cells and has been shown to stimulate lymphangiogenesis in adult mice. However, the role VEGFR2 serves in the development of the lymphatic vascular system has not been defined. Here we use the Cre-lox system to show that the proper development of the lymphatic vasculature requires VEGFR2 expression by lymphatic endothelium. We show that Lyve-1(wt/Cre);Vegfr2(flox/flox) mice possess significantly fewer dermal lymphatic vessels than Vegfr2(flox/flox) mice. Although Lyve-1(wt/Cre);Vegfr2(flox/flox) mice exhibit lymphatic hypoplasia, the lymphatic network is functional and contains all of the key features of a normal lymphatic network (initial lymphatic vessels and valved collecting vessels surrounded by smooth muscle cells (SMCs)). We also show that Lyve-1(Cre) mice display robust Cre activity in macrophages and in blood vessels in the yolk sac, liver and lung. This activity dramatically impairs the development of blood vessels in these tissues in Lyve-1(wt/Cre);Vegfr2(flox/flox) embryos, most of which die after embryonic day14.5. Lastly, we show that inactivation of Vegfr2 in the myeloid lineage does not affect the development of the lymphatic vasculature. Therefore, the abnormal lymphatic phenotype of Lyve-1(wt/Cre);Vegfr2(flox/flox) mice is due to the deletion of Vegfr2 in the lymphatic vasculature not macrophages. Together, this work demonstrates that VEGFR2 directly promotes the expansion of the lymphatic network and further defines the molecular mechanisms controlling the development of the lymphatic vascular system.

  15. The effect of interstitial pressure on therapeutic agent transport: coupling with the tumor blood and lymphatic vascular systems.

    PubMed

    Wu, Min; Frieboes, Hermann B; Chaplain, Mark A J; McDougall, Steven R; Cristini, Vittorio; Lowengrub, John S

    2014-08-21

    Vascularized tumor growth is characterized by both abnormal interstitial fluid flow and the associated interstitial fluid pressure (IFP). Here, we study the effect that these conditions have on the transport of therapeutic agents during chemotherapy. We apply our recently developed vascular tumor growth model which couples a continuous growth component with a discrete angiogenesis model to show that hypertensive IFP is a physical barrier that may hinder vascular extravasation of agents through transvascular fluid flux convection, which drives the agents away from the tumor. This result is consistent with previous work using simpler models without blood flow or lymphatic drainage. We consider the vascular/interstitial/lymphatic fluid dynamics to show that tumors with larger lymphatic resistance increase the agent concentration more rapidly while also experiencing faster washout. In contrast, tumors with smaller lymphatic resistance accumulate less agents but are able to retain them for a longer time. The agent availability (area-under-the curve, or AUC) increases for less permeable agents as lymphatic resistance increases, and correspondingly decreases for more permeable agents. We also investigate the effect of vascular pathologies on agent transport. We show that elevated vascular hydraulic conductivity contributes to the highest AUC when the agent is less permeable, but to lower AUC when the agent is more permeable. We find that elevated interstitial hydraulic conductivity contributes to low AUC in general regardless of the transvascular agent transport capability. We also couple the agent transport with the tumor dynamics to simulate chemotherapy with the same vascularized tumor under different vascular pathologies. We show that tumors with an elevated interstitial hydraulic conductivity alone require the strongest dosage to shrink. We further show that tumors with elevated vascular hydraulic conductivity are more hypoxic during therapy and that the response

  16. The effect of interstitial pressure on therapeutic agent transport: coupling with the tumor blood and lymphatic vascular systems.

    PubMed

    Wu, Min; Frieboes, Hermann B; Chaplain, Mark A J; McDougall, Steven R; Cristini, Vittorio; Lowengrub, John S

    2014-08-21

    Vascularized tumor growth is characterized by both abnormal interstitial fluid flow and the associated interstitial fluid pressure (IFP). Here, we study the effect that these conditions have on the transport of therapeutic agents during chemotherapy. We apply our recently developed vascular tumor growth model which couples a continuous growth component with a discrete angiogenesis model to show that hypertensive IFP is a physical barrier that may hinder vascular extravasation of agents through transvascular fluid flux convection, which drives the agents away from the tumor. This result is consistent with previous work using simpler models without blood flow or lymphatic drainage. We consider the vascular/interstitial/lymphatic fluid dynamics to show that tumors with larger lymphatic resistance increase the agent concentration more rapidly while also experiencing faster washout. In contrast, tumors with smaller lymphatic resistance accumulate less agents but are able to retain them for a longer time. The agent availability (area-under-the curve, or AUC) increases for less permeable agents as lymphatic resistance increases, and correspondingly decreases for more permeable agents. We also investigate the effect of vascular pathologies on agent transport. We show that elevated vascular hydraulic conductivity contributes to the highest AUC when the agent is less permeable, but to lower AUC when the agent is more permeable. We find that elevated interstitial hydraulic conductivity contributes to low AUC in general regardless of the transvascular agent transport capability. We also couple the agent transport with the tumor dynamics to simulate chemotherapy with the same vascularized tumor under different vascular pathologies. We show that tumors with an elevated interstitial hydraulic conductivity alone require the strongest dosage to shrink. We further show that tumors with elevated vascular hydraulic conductivity are more hypoxic during therapy and that the response

  17. The effect of interstitial pressure on therapeutic agent transport: coupling with the tumor blood and lymphatic vascular systems

    PubMed Central

    Wu, Min; Frieboes, Hermann B.; Chaplain, Mark A.J.; McDougall, Steven R.; Cristini, Vittorio; Lowengrub, John

    2014-01-01

    Vascularized tumor growth is characterized by both abnormal interstitial fluid flow and the associated interstitial fluid pressure (IFP). Here, we study the effect that these conditions have on the transport of therapeutic agents during chemotherapy. We apply our recently developed vascular tumor growth model which couples a continuous growth component with a discrete angiogenesis model to show that hypertensive IFP is a physical barrier that may hinder vascular extravasation of agents through transvascular fluid flux convection, which drives the agents away from the tumor. This result is consistent with previous work using simpler models without blood flow or lymphatic drainage. We consider the vascular/interstitial/lymphatic fluid dynamics to show that tumors with larger lymphatic resistance increase the agent concentration more rapidly while also experiencing faster washout. In contrast, tumors with smaller lymphatic resistance accumulate less agents but are able to retain them for a longer time. The agent availability (area-under-the curve, or AUC) increases for less permeable agents as lymphatic resistance increases, and correspondingly decreases for more permeable agents. We also investigate the effect of vascular pathologies on agent transport. We show that elevated vascular hydraulic conductivity contributes to the highest AUC when the agent is less permeable, but leads to lower AUC when the agent is more permeable. We find that elevated interstitial hydraulic conductivity contributes to low AUC in general regardless of the transvascular agent transport capability. We also couple the agent transport with the tumor dynamics to simulate chemotherapy with the same vascularized tumor under different vascular pathologies. We show that tumors with an elevated interstitial hydraulic conductivity alone require the strongest dosage to shrink. We further show that tumors with elevated vascular hydraulic conductivity are more hypoxic during therapy and that the

  18. Coronary responses to cold air inhalation following afferent and efferent blockade

    PubMed Central

    Gao, Zhaohui; McQuillan, Patrick M.; Leuenberger, Urs A.; Sinoway, Lawrence I.

    2014-01-01

    Cardiac ischemia and angina pectoris are commonly experienced during exertion in a cold environment. In the current study we tested the hypotheses that oropharyngeal afferent blockade (i.e., local anesthesia of the upper airway with lidocaine) as well as systemic β-adrenergic receptor blockade (i.e., intravenous propranolol) would improve the balance between myocardial oxygen supply and demand in response to the combined stimulus of cold air inhalation (−15 to −30°C) and isometric handgrip exercise (Cold + Grip). Young healthy subjects underwent Cold + Grip following lidocaine, propranolol, and control (no drug). Heart rate, blood pressure, and coronary blood flow velocity (CBV, from Doppler echocardiography) were continuously measured. Rate-pressure product (RPP) was calculated, and changes from baseline were compared between treatments. The change in RPP at the end of Cold + Grip was not different between lidocaine (2,441 ± 376) and control conditions (3,159 ± 626); CBV responses were also not different between treatments. With propranolol, heart rate (8 ± 1 vs. 14 ± 3 beats/min) and RPP responses to Cold + Grip were significantly attenuated. However, at peak exercise propranolol also resulted in a smaller ΔCBV (1.4 ± 0.8 vs. 5.3 ± 1.4 cm/s, P = 0.035), such that the relationship between coronary flow and cardiac metabolism was impaired under propranolol (0.43 ± 0.37 vs. 2.1 ± 0.63 arbitrary units). These data suggest that cold air breathing and isometric exercise significantly influence efferent control of coronary blood flow. Additionally, β-adrenergic vasodilation may play a significant role in coronary regulation during exercise. PMID:24816257

  19. Functional specializations of primary auditory afferents on the Mauthner cells: interactions between membrane and synaptic properties.

    PubMed

    Curti, Sebastian; Pereda, Alberto E

    2010-01-01

    Primary auditory afferents are usually perceived as passive, timing-preserving, lines of communication. Contrasting this view, a special class of auditory afferents to teleost Mauthner cells, a command neuron that organizes tail-flip escape responses, undergoes potentiation of their mixed (electrical and chemical) synapses in response to high frequency cellular activity. This property is likely to represent a mechanism of input sensitization as these neurons provide the Mauthner cell with essential information for the initiation of an escape response. We review here the anatomical and physiological specializations of these identifiable auditory afferents. In particular, we discuss how their membrane and synaptic properties act in concert to more efficaciously activate the Mauthner cells. The striking functional specializations of these neurons suggest that primary auditory afferents might be capable of more sophisticated contributions to auditory processing than has been generally recognized. PMID:19941953

  20. Functional role of unmyelinated tactile afferents in human hairy skin: sympathetic response and perceptual localization.

    PubMed

    Olausson, Håkan; Cole, Jonathan; Rylander, Karin; McGlone, Francis; Lamarre, Yves; Wallin, B Gunnar; Krämer, Heidrun; Wessberg, Johan; Elam, Mikael; Bushnell, M Catherine; Vallbo, Ake

    2008-01-01

    In addition to A-beta fibres the human hairy skin has unmyelinated (C) fibres responsive to light touch. Previous functional magnetic resonance imaging (fMRI) studies in a subject with a neuronopathy who specifically lacks A-beta afferents indicated that tactile C afferents (CT) activate insular cortex, whereas no response was seen in somatosensory areas 1 and 2. Psychophysical tests suggested that CT afferents give rise to an inconsistent perception of weak and pleasant touch. By examining two neuronopathy subjects as well as control subjects we have now demonstrated that CT stimulation can elicit a sympathetic skin response. Further, the neuronopathy subjects' ability to localize stimuli which activate CT afferents was very poor but above chance level. The findings support the interpretation that the CT system is well suited to underpin affective rather than discriminative functions of tactile sensations.

  1. Pharmacologically Distinct Nicotinic Acetylcholine Receptors Drive Efferent-Mediated Excitation in Calyx-Bearing Vestibular Afferents

    PubMed Central

    Kewin, Kevin; Jordan, Paivi M.; Cameron, Peter; Klapczynski, Marcin; McIntosh, J. Michael; Crooks, Peter A.; Dwoskin, Linda P.; Lysakowski, Anna

    2015-01-01

    Electrical stimulation of vestibular efferent neurons rapidly excites the resting discharge of calyx/dimorphic (CD) afferents. In turtle, this excitation arises when acetylcholine (ACh), released from efferent terminals, directly depolarizes calyceal endings by activating nicotinic ACh receptors (nAChRs). Although molecular biological data from the peripheral vestibular system implicate most of the known nAChR subunits, specific information about those contributing to efferent-mediated excitation of CD afferents is lacking. We sought to identify the nAChR subunits that underlie the rapid excitation of CD afferents and whether they differ from α9α10 nAChRs on type II hair cells that drive efferent-mediated inhibition in adjacent bouton afferents. We recorded from CD and bouton afferents innervating the turtle posterior crista during electrical stimulation of vestibular efferents while applying several subtype-selective nAChR agonists and antagonists. The α9α10 nAChR antagonists, α-bungarotoxin and α-conotoxin RgIA, blocked efferent-mediated inhibition in bouton afferents while leaving efferent-mediated excitation in CD units largely intact. Conversely, 5-iodo-A-85380, sazetidine-A, varenicline, α-conotoxin MII, and bPiDDB (N,N-dodecane-1,12-diyl-bis-3-picolinium dibromide) blocked efferent-mediated excitation in CD afferents without affecting efferent-mediated inhibition in bouton afferents. This pharmacological profile suggested that calyceal nAChRs contain α6 and β2, but not α9, nAChR subunits. Selective blockade of efferent-mediated excitation in CD afferents distinguished dimorphic from calyx afferents by revealing type II hair cell input. Dimorphic afferents differed in having higher mean discharge rates and a mean efferent-mediated excitation that was smaller in amplitude yet longer in duration. Molecular biological data demonstrated the expression of α9 in turtle hair cells and α4 and β2 in associated vestibular ganglia. PMID:25716861

  2. Lysophosphatidic acid does not cause blood/lymphatic vessel plasticity in the rat mesentery culture model.

    PubMed

    Sweat, Richard S; Azimi, Mohammad S; Suarez-Martinez, Ariana D; Katakam, Prasad; Murfee, Walter L

    2016-07-01

    Understanding the mechanisms behind endothelial cell identity is crucial for the goal of manipulating microvascular networks. Lysophosphatidic acid (LPA) and serum stimulation have been suggested to induce a lymphatic identity in blood endothelial cells in vitro. The objective of this study was to determine if LPA or serum induces blood-to-lymphatic vessel phenotypic transition in microvascular networks. The rat mesentery culture model was used to observe the effect of stimulation on blood and lymphatic microvascular networks ex vivo. Vascularized mesenteric tissues were harvested from adult Wistar rats and cultured with LPA or 10% serum for up to 5 days. Tissues were then immunolabeled with PECAM to identify blood vessels and LYVE-1 or Prox1 to identify lymphatic vessels. We show that while LPA caused capillary sprouting and increased vascular length density in adult microvascular networks, LPA did not cause a blood-to-lymphatic phenotypic transition. The results suggest that LPA is not sufficient to cause blood endothelial cells to adopt a lymphatic identity in adult microvascular networks. Similarly, serum stimulation caused robust angiogenesis and increased lymphatic/blood vessel connections, yet did not induce a blood-to-lymphatic phenotypic transition. Our study highlights an understudied area of lymphatic research and warrants future investigation into the mechanisms responsible for the maintenance of blood and lymphatic vessel identity. PMID:27401461

  3. Angiopoietin 2 regulates the transformation and integrity of lymphatic endothelial cell junctions

    PubMed Central

    Zheng, Wei; Nurmi, Harri; Appak, Sila; Sabine, Amélie; Bovay, Esther; Korhonen, Emilia A.; Orsenigo, Fabrizio; Lohela, Marja; D’Amico, Gabriela; Holopainen, Tanja; Leow, Ching Ching; Dejana, Elisabetta; Petrova, Tatiana V.; Augustin, Hellmut G.; Alitalo, Kari

    2014-01-01

    Primitive lymphatic vessels are remodeled into functionally specialized initial and collecting lymphatics during development. Lymphatic endothelial cell (LEC) junctions in initial lymphatics transform from a zipper-like to a button-like pattern during collecting vessel development, but what regulates this process is largely unknown. Angiopoietin 2 (Ang2) deficiency leads to abnormal lymphatic vessels. Here we found that an ANG2-blocking antibody inhibited embryonic lymphangiogenesis, whereas endothelium-specific ANG2 overexpression induced lymphatic hyperplasia. ANG2 inhibition blocked VE-cadherin phosphorylation at tyrosine residue 685 and the concomitant formation of button-like junctions in initial lymphatics. The defective junctions were associated with impaired lymph uptake. In collecting lymphatics, adherens junctions were disrupted, and the vessels leaked upon ANG2 blockade or gene deletion. ANG2 inhibition also suppressed the onset of lymphatic valve formation and subsequent valve maturation. These data identify ANG2 as the first essential regulator of the functionally important interendothelial cell–cell junctions that form during lymphatic development. PMID:25030698

  4. Angiopoietin 2 regulates the transformation and integrity of lymphatic endothelial cell junctions.

    PubMed

    Zheng, Wei; Nurmi, Harri; Appak, Sila; Sabine, Amélie; Bovay, Esther; Korhonen, Emilia A; Orsenigo, Fabrizio; Lohela, Marja; D'Amico, Gabriela; Holopainen, Tanja; Leow, Ching Ching; Dejana, Elisabetta; Petrova, Tatiana V; Augustin, Hellmut G; Alitalo, Kari

    2014-07-15

    Primitive lymphatic vessels are remodeled into functionally specialized initial and collecting lymphatics during development. Lymphatic endothelial cell (LEC) junctions in initial lymphatics transform from a zipper-like to a button-like pattern during collecting vessel development, but what regulates this process is largely unknown. Angiopoietin 2 (Ang2) deficiency leads to abnormal lymphatic vessels. Here we found that an ANG2-blocking antibody inhibited embryonic lymphangiogenesis, whereas endothelium-specific ANG2 overexpression induced lymphatic hyperplasia. ANG2 inhibition blocked VE-cadherin phosphorylation at tyrosine residue 685 and the concomitant formation of button-like junctions in initial lymphatics. The defective junctions were associated with impaired lymph uptake. In collecting lymphatics, adherens junctions were disrupted, and the vessels leaked upon ANG2 blockade or gene deletion. ANG2 inhibition also suppressed the onset of lymphatic valve formation and subsequent valve maturation. These data identify ANG2 as the first essential regulator of the functionally important interendothelial cell-cell junctions that form during lymphatic development. PMID:25030698

  5. Angiopoietin 2 regulates the transformation and integrity of lymphatic endothelial cell junctions.

    PubMed

    Zheng, Wei; Nurmi, Harri; Appak, Sila; Sabine, Amélie; Bovay, Esther; Korhonen, Emilia A; Orsenigo, Fabrizio; Lohela, Marja; D'Amico, Gabriela; Holopainen, Tanja; Leow, Ching Ching; Dejana, Elisabetta; Petrova, Tatiana V; Augustin, Hellmut G; Alitalo, Kari

    2014-07-15

    Primitive lymphatic vessels are remodeled into functionally specialized initial and collecting lymphatics during development. Lymphatic endothelial cell (LEC) junctions in initial lymphatics transform from a zipper-like to a button-like pattern during collecting vessel development, but what regulates this process is largely unknown. Angiopoietin 2 (Ang2) deficiency leads to abnormal lymphatic vessels. Here we found that an ANG2-blocking antibody inhibited embryonic lymphangiogenesis, whereas endothelium-specific ANG2 overexpression induced lymphatic hyperplasia. ANG2 inhibition blocked VE-cadherin phosphorylation at tyrosine residue 685 and the concomitant formation of button-like junctions in initial lymphatics. The defective junctions were associated with impaired lymph uptake. In collecting lymphatics, adherens junctions were disrupted, and the vessels leaked upon ANG2 blockade or gene deletion. ANG2 inhibition also suppressed the onset of lymphatic valve formation and subsequent valve maturation. These data identify ANG2 as the first essential regulator of the functionally important interendothelial cell-cell junctions that form during lymphatic development.

  6. Lysophosphatidic acid does not cause blood/lymphatic vessel plasticity in the rat mesentery culture model.

    PubMed

    Sweat, Richard S; Azimi, Mohammad S; Suarez-Martinez, Ariana D; Katakam, Prasad; Murfee, Walter L

    2016-07-01

    Understanding the mechanisms behind endothelial cell identity is crucial for the goal of manipulating microvascular networks. Lysophosphatidic acid (LPA) and serum stimulation have been suggested to induce a lymphatic identity in blood endothelial cells in vitro. The objective of this study was to determine if LPA or serum induces blood-to-lymphatic vessel phenotypic transition in microvascular networks. The rat mesentery culture model was used to observe the effect of stimulation on blood and lymphatic microvascular networks ex vivo. Vascularized mesenteric tissues were harvested from adult Wistar rats and cultured with LPA or 10% serum for up to 5 days. Tissues were then immunolabeled with PECAM to identify blood vessels and LYVE-1 or Prox1 to identify lymphatic vessels. We show that while LPA caused capillary sprouting and increased vascular length density in adult microvascular networks, LPA did not cause a blood-to-lymphatic phenotypic transition. The results suggest that LPA is not sufficient to cause blood endothelial cells to adopt a lymphatic identity in adult microvascular networks. Similarly, serum stimulation caused robust angiogenesis and increased lymphatic/blood vessel connections, yet did not induce a blood-to-lymphatic phenotypic transition. Our study highlights an understudied area of lymphatic research and warrants future investigation into the mechanisms responsible for the maintenance of blood and lymphatic vessel identity.

  7. Excitation of rat colonic afferent fibres by 5-HT3 receptors

    PubMed Central

    Hicks, Gareth A; Coldwell, Jonathan R; Schindler, Marcus; Bland Ward, Philip A; Jenkins, David; Lynn, Penny A; Humphrey, Patrick P A; Blackshaw, L Ashley

    2002-01-01

    The gastrointestinal tract contains most of the body's 5-hydroxytryptamine (5-HT) and releases large amounts after meals or exposure to toxins. Increased 5-HT release occurs in patients with irritable bowel syndrome (IBS) and their peak plasma 5-HT levels correlate with pain episodes. 5-HT3 receptor antagonists reduce symptoms of IBS clinically, but their site of action is unclear and the potential for other therapeutic targets is unexplored. Here we investigated effects of 5-HT on sensory afferents from the colon and the expression of 5-HT3 receptors on their cell bodies in the dorsal root ganglia (DRG). Distal colon, inferior mesenteric ganglion and the lumbar splanchnic nerve bundle (LSN) were placed in a specialized organ bath. Eighty-six single fibres were recorded from the LSN. Three classes of primary afferents were found: 70 high-threshold serosal afferents, four low-threshold muscular afferents and 12 mucosal afferents. Afferent cell bodies were retrogradely labelled from the distal colon to the lumbar DRG, where they were processed for 5-HT3 receptor-like immunoreactivity. Fifty-six percent of colonic afferents responded to 5-HT (between 10−6 and 10−3 M) and 30 % responded to the selective 5-HT3 agonist, 2-methyl-5-HT (between 10−6 and 10−2 M). Responses to 2-methyl-5-HT were blocked by the 5-HT3 receptor antagonist alosetron (2 × 10−7 M), whereas responses to 5-HT were only partly inhibited. Twenty-six percent of L1 DRG cell bodies retrogradely labelled from the colon displayed 5-HT3 receptor-like immunoreactivity. We conclude that colonic sensory neurones expressing 5-HT3 receptors also functionally express the receptors at their peripheral endings. Our data reveal actions of 5-HT on colonic afferent endings via both 5-HT3 and non-5-HT3 receptors. PMID:12411529

  8. Genetic and pharmacological evidence for low-abundance TRPV3 expression in primary vagal afferent neurons.

    PubMed

    Wu, Shaw-Wen; Lindberg, Jonathan E M; Peters, James H

    2016-05-01

    Primary vagal afferent neurons express a multitude of thermosensitive ion channels. Within this family of ion channels, the heat-sensitive capsaicin receptor (TRPV1) greatly influences vagal afferent signaling by determining the threshold for action-potential initiation at the peripheral endings, while controlling temperature-sensitive forms of glutamate release at central vagal terminals. Genetic deletion of TRPV1 does not completely eliminate these temperature-dependent effects, suggesting involvement of additional thermosensitive ion channels. The warm-sensitive, calcium-permeable, ion channel TRPV3 is commonly expressed with TRPV1; however, the extent to which TRPV3 is found in vagal afferent neurons is unknown. Here, we begin to characterize the genetic and functional expression of TRPV3 in vagal afferent neurons using molecular biology (RT-PCR and RT-quantitative PCR) in whole nodose and isolated neurons and fluorescent calcium imaging on primary cultures of nodose ganglia neurons. We confirmed low-level TRPV3 expression in vagal afferent neurons and observed direct activation with putative TRPV3 agonists eugenol, ethyl vanillin (EVA), and farnesyl pyrophosphate (FPP). Agonist activation stimulated neurons also containing TRPV1 and was blocked by ruthenium red. FPP sensitivity overlapped with EVA and eugenol but represented the smallest percentage of vagal afferent neurons, and it was the only agonist that did not stimulate neurons from TRPV3(-/-1) mice, suggesting FPP has the highest selectivity. Further, FPP was predictive of enhanced responses to capsaicin, EVA, and eugenol in rats. From our results, we conclude TRPV3 is expressed in a discrete subpopulation of vagal afferent neurons and may contribute to vagal afferent signaling either directly or in combination with TRPV1. PMID:26843581

  9. Altered colorectal afferent function associated with TNBS-induced visceral hypersensitivity in mice.

    PubMed

    Feng, Bin; La, Jun-Ho; Tanaka, Takahiro; Schwartz, Erica S; McMurray, Timothy P; Gebhart, G F

    2012-10-01

    Inflammation of the distal bowel is often associated with abdominal pain and hypersensitivity, but whether and which colorectal afferents contribute to the hypersensitivity is unknown. Using a mouse model of 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis, we investigated colorectal hypersensitivity following intracolonic TNBS and associated changes in colorectum and afferent functions. C57BL/6 mice were treated intracolonically with TNBS or saline. Visceromotor responses to colorectal distension (15-60 mmHg) were recorded over 8 wk in TNBS- and saline-treated (control) mice. In other mice treated with TNBS or saline, colorectal inflammation was assessed by myeloperoxidase assay and immunohistological staining. In vitro single-fiber recordings were conducted on both TNBS and saline-treated mice to assess colorectal afferent function. Mice exhibited significant colorectal hypersensitivity through day 14 after TNBS treatment that resolved by day 28 with no resensitization through day 56. TNBS induced a neutrophil- and macrophage-based colorectal inflammation as well as loss of nerve fibers, all of which resolved by days 14-28. Single-fiber recordings revealed a net increase in afferent drive from stretch-sensitive colorectal afferents at day 14 post-TNBS and reduced proportions of mechanically insensitive afferents (MIAs) at days 14-28. Intracolonic TNBS-induced colorectal inflammation was associated with the development and recovery of hypersensitivity in mice, which correlated with a transient increase and recovery of sensitization of stretch-sensitive colorectal afferents and MIAs. These results indicate that the development and maintenance of colorectal hypersensitivity following inflammation are mediated by peripheral drive from stretch-sensitive colorectal afferents and a potential contribution from MIAs.

  10. Altered colorectal afferent function associated with TNBS-induced visceral hypersensitivity in mice

    PubMed Central

    La, Jun-Ho; Tanaka, Takahiro; Schwartz, Erica S.; McMurray, Timothy P.; Gebhart, G. F.

    2012-01-01

    Inflammation of the distal bowel is often associated with abdominal pain and hypersensitivity, but whether and which colorectal afferents contribute to the hypersensitivity is unknown. Using a mouse model of 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis, we investigated colorectal hypersensitivity following intracolonic TNBS and associated changes in colorectum and afferent functions. C57BL/6 mice were treated intracolonically with TNBS or saline. Visceromotor responses to colorectal distension (15–60 mmHg) were recorded over 8 wk in TNBS- and saline-treated (control) mice. In other mice treated with TNBS or saline, colorectal inflammation was assessed by myeloperoxidase assay and immunohistological staining. In vitro single-fiber recordings were conducted on both TNBS and saline-treated mice to assess colorectal afferent function. Mice exhibited significant colorectal hypersensitivity through day 14 after TNBS treatment that resolved by day 28 with no resensitization through day 56. TNBS induced a neutrophil- and macrophage-based colorectal inflammation as well as loss of nerve fibers, all of which resolved by days 14–28. Single-fiber recordings revealed a net increase in afferent drive from stretch-sensitive colorectal afferents at day 14 post-TNBS and reduced proportions of mechanically insensitive afferents (MIAs) at days 14–28. Intracolonic TNBS-induced colorectal inflammation was associated with the development and recovery of hypersensitivity in mice, which correlated with a transient increase and recovery of sensitization of stretch-sensitive colorectal afferents and MIAs. These results indicate that the development and maintenance of colorectal hypersensitivity following inflammation are mediated by peripheral drive from stretch-sensitive colorectal afferents and a potential contribution from MIAs. PMID:22859364

  11. Activation of guanylate cyclase-C attenuates stretch responses and sensitization of mouse colorectal afferents

    PubMed Central

    Feng, Bin; Kiyatkin, Michael E.; La, Jun-Ho; Ge, Pei; Solinga, Robert; Silos-Santiago, Inmaculada; Gebhart, G.F.

    2013-01-01

    Irritable bowel syndrome (IBS) is characterized by altered bowel habits, persistent pain and discomfort, and typically colorectal hypersensitivity. Linaclotide, a peripherally-restricted 14-amino acid peptide approved for the treatment of IBS with constipation, relieves constipation and reduces IBS-associated pain in these patients presumably by activation of guanylate cyclase-C (GC-C), which stimulates production and release of cyclic guanosine monophosphate (cGMP) from intestinal epithelial cells. We investigated whether activation of GC-C by the endogenous agonist uroguanylin or the primary downstream effector of that activation, cGMP, directly modulates responses and sensitization of mechanosensitive colorectal primary afferents. The distal 2 cm of mouse colorectum with attached pelvic nerve was harvested, pinned flat mucosal side up for in vitro single-fiber recordings and the encoding properties of mechanosensitive afferents (serosal, mucosal, muscular and muscular-mucosal) to probing and circumferential stretch studied. Both cGMP (10–300μM) and uroguanylin (1–1000nM) applied directly to colorectal receptive endings significantly reduced responses of muscular and muscular-mucosal afferents to stretch; serosal and mucosal afferents were not affected. Sensitized responses (i.e., increased responses to stretch) of muscular and muscular-mucosal afferents were reversed by cGMP, returning responses to stretch to control. Blocking the transport of cGMP from colorectal epithelia by probenecid, a mechanism validated by studies in cultured intestinal T84 cells, abolished the inhibitory effect of uroguanylin on muscular-mucosal afferents. These results suggest that GC-C agonists like linaclotide alleviate colorectal pain and hypersensitivity by dampening stretch-sensitive afferent mechanosensitivity and normalizing afferent sensitization. PMID:23739979

  12. Enhanced sympathetic activity and cardiac sympathetic afferent reflex in rats with heart failure induced by adriamycin.

    PubMed

    Zhang, Shujuan; Zhang, Feng; Sun, Haijian; Zhou, Yebo; Han, Ying

    2012-11-01

    Our previous studies have shown that the cardiac sympathetic afferent reflex is enhanced in rats with chronic heart failure (CHF) induced by coronary artery ligation and contributes to the over-excitation of sympathetic activity. We sought to determine whether sympathetic activity and cardiac sympathetic afferent reflex were enhanced in adriamycin-induced CHF and whether angiotensin II (Ang II) in the paraventricular nucleus (PVN) was involved in enhancing sympathetic activity and cardiac sympathetic afferent reflex. Heart failure was induced by intraperitoneal injection of adriamycin for six times during 2 weeks (15 mg/kg). Six weeks after the first injection, the rats underwent anesthesia with urethane and α-chloralose. After vagotomy and baroreceptor denervation, cardiac sympathetic afferent reflex was evaluated by renal sympathetic nerve activity and mean arterial pressure (MAP) response to epicardial application of capsaicin (1.0 nmol). The response of MAP to ganglionic blockade with hexamethonium in conscious rats was performed to evaluate sympathetic activity. The renal sympathetic nerve activity and cardiac sympathetic afferent reflex were enhanced in adriamycin rats and the maximum depressor response of MAP induced by hexamethonium was significantly greater in adriamycin rats than that in control rats. Bilateral PVN microinjection of angiotensin II (Ang II) caused larger responses of the cardiac sympathetic afferent reflex, baseline renal sympathetic nerve activity and MAP in adriamycin rats than control rats. These results indicated that both sympathetic activity and cardiac sympathetic afferent reflex were enhanced and Ang II in the PVN was involved in the enhanced sympathetic activity and cardiac sympathetic afferent reflex in rats with adriamycin-induced heart failure. PMID:23554781

  13. Influence of map scale on primary afferent terminal field geometry in cat dorsal horn.

    PubMed

    Millecchia, R J; Pubols, L M; Sonty, R V; Culberson, J L; Gladfelter, W E; Brown, P B

    1991-09-01

    1. Thirty-one physiologically identified primary afferent fibers were labeled intracellularly with horseradish peroxidase (HRP). 2. A computer analysis was used to determine whether the distribution of cutaneous mechanoreceptive afferent terminals varies as a function of location within the dorsal horn somatotopic map. 3. An analysis of the geometry of the projections of these afferents has shown that 1) terminal arbors have a greater mediolateral width within the region of the foot representation than lateral to it, 2) terminal arbors have larger length-to-width ratios outside the foot representation than within it, and 3) the orientation of terminal arbors near the boundary of the foot representation reflects the angle of the boundary. Previous attribution of mediolateral width variations to primary afferent type are probably in error, although there appear to be genuine variations of longitudinal extent as a function of primary afferent type. 4. Nonuniform terminal distributions represent the first of a three-component process underlying assembly of the monosynaptic portions of cell receptive fields (RFs) and the somatotopic map. The other two components consist of the elaboration of cell dendritic trees and the establishment of selective connections. 5. The variation of primary afferent terminal distributions with map location is not an absolute requirement for development of the map; for example, the RFs of postsynaptic cells could be assembled with the use of a uniform terminal distribution for all afferents, everywhere in the map, as long as cell dendrites penetrate the appropriate portions of the presynaptic neuropil and receive connections only from afferent axons contributing to their RFs.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1753281

  14. Innervation of enteric mast cells by primary spinal afferents in guinea pig and human small intestine.

    PubMed

    Wang, Guo-Du; Wang, Xi-Yu; Liu, Sumei; Qu, Meihua; Xia, Yun; Needleman, Bradley J; Mikami, Dean J; Wood, Jackie D

    2014-10-01

    Mast cells express the substance P (SP) neurokinin 1 receptor and the calcitonin gene-related peptide (CGRP) receptor in guinea pig and human small intestine. Enzyme-linked immunoassay showed that activation of intramural afferents by antidromic electrical stimulation or by capsaicin released SP and CGRP from human and guinea pig intestinal segments. Electrical stimulation of the afferents evoked slow excitatory postsynaptic potentials (EPSPs) in the enteric nervous system. The slow EPSPs were mediated by tachykinin neurokinin 1 and CGRP receptors. Capsaicin evoked slow EPSP-like responses that were suppressed by antagonists for protease-activated receptor 2. Afferent stimulation evoked slow EPSP-like excitation that was suppressed by mast cell-stabilizing drugs. Histamine and mast cell protease II were released by 1) exposure to SP or CGRP, 2) capsaicin, 3) compound 48/80, 4) elevation of mast cell Ca²⁺ by ionophore A23187, and 5) antidromic electrical stimulation of afferents. The mast cell stabilizers cromolyn and doxantrazole suppressed release of protease II and histamine when evoked by SP, CGRP, capsaicin, A23187, electrical stimulation of afferents, or compound 48/80. Neural blockade by tetrodotoxin prevented mast cell protease II release in response to antidromic electrical stimulation of mesenteric afferents. The results support a hypothesis that afferent innervation of enteric mast cells releases histamine and mast cell protease II, both of which are known to act in a diffuse paracrine manner to influence the behavior of enteric nervous system neurons and to elevate the sensitivity of spinal afferent terminals.

  15. LyP-1-conjugated doxorubicin-loaded liposomes suppress lymphatic metastasis by inhibiting lymph node metastases and destroying tumor lymphatics

    NASA Astrophysics Data System (ADS)

    Yan, Zhiqiang; Zhan, Changyou; Wen, Ziyi; Feng, Linglin; Wang, Fei; Liu, Yu; Yang, Xiangkun; Dong, Qing; Liu, Min; Lu, Weiyue

    2011-10-01

    Lymphatic metastasis can be greatly promoted by metastases growth and lymphangiogenesis in lymph nodes (LNs). LyP-1, a cyclic peptide, is able to specifically bind with tumor cells and tumor lymphatics in metastatic LNs. This work aimed to use LyP-1-conjugated liposomes (L-LS) loaded with doxorubicin (DOX) (L-LS/DOX) to suppress lymphatic metastasis by inhibiting both metastases and tumor lymphatics in LNs. L-LS were prepared and exhibited sizes around 90 nm and spherical morphology as characterized by transmission electron microscopy. The in vitro cellular studies showed that LyP-1 modification obviously increased liposome uptake by MDA-MB-435 tumor cells and enhanced the cytotoxicity of liposomal DOX. A popliteal and iliac LN metastases model was successfully established by subcutaneous inoculation of tumor cells to nude mice. The immunofluorescence staining analysis indicated that LyP-1 modification enabled specific binding of liposome with tumor lymphatics and enhanced the destroying effect of liposomal DOX on tumor lymphatics. The in vivo fluorescence imaging and pharmacodynamic studies showed that LyP-1 modification increased liposome uptake by metastatic LNs and that L-LS/DOX significantly decreased metastatic LN growth and LN metastasis rate. These results suggested that L-LS/DOX were an effective delivery system for suppressing lymphatic metastasis by simultaneously inhibiting LN metastases and tumor lymphatics.

  16. Quantitative study of the topographic distribution of conjunctival lymphatic vessels in the monkey.

    PubMed

    Guo, Wenyi; Zhu, Yuanfang; Yu, Paula K; Yu, Xiaobo; Sun, Xinghuai; Cringle, Stephen J; Su, Er-Ning; Yu, Dao-Yi

    2012-01-01

    The purpose of this study was to quantify the topographic distribution of bulbar conjunctival microlymphatic vessels in the monkey. Sixteen eyes from 8 rhesus monkeys were used. Full thickness pieces of globe wall were excised from each quadrant. Cryosections were stained for 5'-nucleotidase, an enzyme histochemical staining for lymphatic vessels, or vascular endothelial growth factor receptor-3, an immunohistochemical marker for the identification of lymphatic endothelial cells, and then counterstained by hematoxylin. The remaining bulbar conjunctiva was dissected and flat mounted. The tissue was then processed with 5'-nucleotidase and alkaline phosphatase, an enzyme histochemical stain with higher activity in blood vessels. Microscope images were further analysed by image processing. The density of lymphatics, diameter of lymphatic vessels, and the size of the drainage zone of each blind end of the initial lymphatics were studied. Conjunctival lymphatics consisted of initial lymphatics and pre-collectors. The initial lymphatics with blind ends were predominately distributed just under the epithelium. The density of these lymphatics (∼50%) and the drainage zone area (∼0.81 mm(2)) was similar in each quadrant, with no difference in the limbus and fornix regions. The average diameter of lymphatic vessels in each quadrant ranged from 82 to 111 μm, and was greater in the superior and nasal regions. Larger calibre pre-collectors with valve-like structures were mostly located sub Tenon's membrane and predominantly located in the region mid-way between the limbus and fornix. There was a marked depth difference in initial lymphatic distribution, with the initial lymphatics mostly confined to the region between Tenon's membrane and the conjunctival epithelium. Detailed knowledge of the topographic distribution of conjunctival lymphatics have significant relevance to a better understanding of immunology, drug delivery, glaucoma filtration surgery, and tumour

  17. Linear Path Integration Deficits in Patients with Abnormal Vestibular Afference

    PubMed Central

    Arthur, Joeanna C.; Kortte, Kathleen B.; Shelhamer, Mark; Schubert, Michael C.

    2014-01-01

    Effective navigation requires the ability to keep track of one’s location and maintain orientation during linear and angular displacements. Path integration is the process of updating the representation of body position by integrating internally-generated self-motion signals over time (e.g., walking in the dark). One major source of input to path integration is vestibular afference. We tested patients with reduced vestibular function (unilateral vestibular hypofunction, UVH), patients with aberrant vestibular function (benign paroxysmal positional vertigo, BPPV), and healthy participants (controls) on two linear path integration tasks: experimenter-guided walking and target-directed walking. The experimenter-guided walking task revealed a systematic underestimation of self-motion signals in UVH patients compared to the other groups. However, we did not find any difference in the distance walked between the UVH group and the control group for the target-directed walking task. Results from neuropsychological testing and clinical balance measures suggest that the errors in experimenter-guided walking were not attributable to cognitive and/or balance impairments. We conclude that impairment in linear path integration in UVH patients stem from deficits in self-motion perception. Importantly, our results also suggest that patients with a UVH deficit do not lose their ability to walk accurately without vision to a memorized target location. PMID:22726251

  18. Afference copy as a quantitative neurophysiological model for consciousness.

    PubMed

    Cornelis, Hugo; Coop, Allan D

    2014-06-01

    Consciousness is a topic of considerable human curiosity with a long history of philosophical analysis and debate. We consider there is nothing particularly complicated about consciousness when viewed as a necessary process of the vertebrate nervous system. Here, we propose a physiological "explanatory gap" is created during each present moment by the temporal requirements of neuronal activity. The gap extends from the time exteroceptive and proprioceptive stimuli activate the nervous system until they emerge into consciousness. During this "moment", it is impossible for an organism to have any conscious knowledge of the ongoing evolution of its environment. In our schematic model, a mechanism of "afference copy" is employed to bridge the explanatory gap with consciously experienced percepts. These percepts are fabricated from the conjunction of the cumulative memory of previous relevant experience and the given stimuli. They are structured to provide the best possible prediction of the expected content of subjective conscious experience likely to occur during the period of the gap. The model is based on the proposition that the neural circuitry necessary to support consciousness is a product of sub/preconscious reflexive learning and recall processes. Based on a review of various psychological and neurophysiological findings, we develop a framework which contextualizes the model and briefly discuss further implications. PMID:25012715

  19. Afference copy as a quantitative neurophysiological model for consciousness.

    PubMed

    Cornelis, Hugo; Coop, Allan D

    2014-06-01

    Consciousness is a topic of considerable human curiosity with a long history of philosophical analysis and debate. We consider there is nothing particularly complicated about consciousness when viewed as a necessary process of the vertebrate nervous system. Here, we propose a physiological "explanatory gap" is created during each present moment by the temporal requirements of neuronal activity. The gap extends from the time exteroceptive and proprioceptive stimuli activate the nervous system until they emerge into consciousness. During this "moment", it is impossible for an organism to have any conscious knowledge of the ongoing evolution of its environment. In our schematic model, a mechanism of "afference copy" is employed to bridge the explanatory gap with consciously experienced percepts. These percepts are fabricated from the conjunction of the cumulative memory of previous relevant experience and the given stimuli. They are structured to provide the best possible prediction of the expected content of subjective conscious experience likely to occur during the period of the gap. The model is based on the proposition that the neural circuitry necessary to support consciousness is a product of sub/preconscious reflexive learning and recall processes. Based on a review of various psychological and neurophysiological findings, we develop a framework which contextualizes the model and briefly discuss further implications.

  20. Cytosolic calcium regulation in rat afferent vagal neurons during anoxia.

    PubMed

    Henrich, Michael; Buckler, Keith J

    2013-12-01

    Sensory neurons are able to detect tissue ischaemia and both transmit information to the brainstem as well as release local vasoactive mediators. Their ability to sense tissue ischaemia is assumed to be primarily mediated through proton sensing ion channels, lack of oxygen however may also affect sensory neuron function. In this study we investigated the effects of anoxia on isolated capsaicin sensitive neurons from rat nodose ganglion. Acute anoxia triggered a reversible increase in [Ca2+]i that was mainly due to Ca2+-efflux from FCCP sensitive stores and from caffeine and CPA sensitive ER stores. Prolonged anoxia resulted in complete depletion of ER Ca2+-stores. Mitochondria were partially depolarised by acute anoxia but mitochondrial Ca2+-uptake/buffering during voltage-gated Ca2+-influx was unaffected. The process of Ca2+-release from mitochondria and cytosolic Ca2+-clearance following Ca2+ influx was however significantly slowed. Anoxia was also found to inhibit SERCA activity and, to a lesser extent, PMCA activity. Hence, anoxia has multiple influences on [Ca2+]i homeostasis in vagal afferent neurons, including depression of ATP-driven Ca2+-pumps, modulation of the kinetics of mitochondrial Ca2+ buffering/release and Ca2+-release from, and depletion of, internal Ca2+-stores. These effects are likely to influence sensory neuronal function during ischaemia. PMID:24189167

  1. The role of the renal afferent and efferent nerve fibers in heart failure

    PubMed Central

    Booth, Lindsea C.; May, Clive N.; Yao, Song T.

    2015-01-01

    Renal nerves contain afferent, sensory and efferent, sympathetic nerve fibers. In heart failure (HF) there is an increase in renal sympathetic nerve activity (RSNA), which can lead to renal vasoconstriction, increased renin release and sodium retention. These changes are thought to contribute to renal dysfunction, which is predictive of poor outcome in patients with HF. In contrast, the role of the renal afferent nerves remains largely unexplored in HF. This is somewhat surprising as there are multiple triggers in HF that have the potential to increase afferent nerve activity, including increased venous pressure and reduced kidney perfusion. Some of the few studies investigating renal afferents in HF have suggested that at least the sympatho-inhibitory reno-renal reflex is blunted. In experimentally induced HF, renal denervation, both surgical and catheter-based, has been associated with some improvements in renal and cardiac function. It remains unknown whether the effects are due to removal of the efferent renal nerve fibers or afferent renal nerve fibers, or a combination of both. Here, we review the effects of HF on renal efferent and afferent nerve function and critically assess the latest evidence supporting renal denervation as a potential treatment in HF. PMID:26483699

  2. Habenular and other midbrain raphe afferents demonstrated by a modified retrograde tracing technique.

    PubMed

    Aghajanian, G K; Wang, R Y

    1977-02-18

    Afferents to th midbrain dorsal and median raphe nuclei in the rat were studied by means of the horseradish peroxidase (HRP) retrograde transport method. The HRP was given by means of a modified iontophoretic delivery technique. This technique permitted an efficient and localized deposition of a high concentration of HRP into the raphe nuclei. Afferents to the raphe as determined by this method could be categorized into 2 classes; those exclusively to the raphe and those also positive for adjacent reticular formation. The most striking afferent area to the raphe, both in terms of selectivity and density, was the lateral habenula. This result is in accord with previous studies using degeneration methods which indicate an habenular projection to the raphe area. There were afferents exclusively positive for the dorsal raphe nucleus emanating from the nucleus of the solitary tract. Most other raphe afferent areas were also positive for the reticular formation (e.g;, prefrontal cortex, medial forebrain bundle, preoptic nuclei, and reticular formation). The existence of a major afferent system from the lateral habenula to the midbrain raphe is consistent with the concept of a "dorsal pathway" which might be responsible for relaying information from forebrain limbic structures to the "midbrain limbic areas".

  3. Classification of longissimus lumborum muscle spindle afferents in the anaesthetized cat.

    PubMed

    Durbaba, R; Taylor, A; Ellaway, P H; Rawlinson, S

    2006-03-01

    Recordings have been made from 127 single muscle spindle afferents from the longissimus lumborum muscles of anaesthetized cats. They have been characterized by their responses to passive muscle stretch and the effects of succinylcholine (SCh) and by their sensitivity to vibration. The use of SCh permitted the assessment for each afferent of the influence of bag1 (b1) and bag2 (b2) intrafusal muscle fibres. From this, on the assumption that all afferents were affected by chain (c) fibres, they were classified in four groups: b1b2c (41.9%), b2c (51.4%), b1c (1.3%) and c (5.4%). All the afferents with b1 influence were able to respond one to one to vibration at frequencies above 100 Hz and were considered to belong to primary endings. On the basis of the vibration test, 64% of the b2c type afferents appeared to be primaries and 36% secondaries. Of the units classified as primaries, 41% were designated as b2c and would not therefore be able to respond to dynamic fusimotor activity. The significance of this relatively high proportion of b2c-type spindle primary afferents is discussed in relation to the specialized postural function of the back muscles.

  4. Core content for training in venous and lymphatic medicine

    PubMed Central

    Min, Robert J; Comerota, Anthony J; Meissner, Mark H; Carman, Teresa L; Rathbun, Suman W; Jaff, Michael R; Wakefield, Thomas W; Feied, Craig F

    2014-01-01

    The major venous societies in the United States share a common mission to improve the standards of medical practitioners, the educational goals for teaching and training programs in venous disease, and the quality of patient care related to the treatment of venous disorders. With these important goals in mind, a task force made up of experts from the specialties of dermatology, interventional radiology, phlebology, vascular medicine, and vascular surgery was formed to develop a consensus document describing the Core Content for venous and lymphatic medicine and to develop a core educational content outline for training. This outline describes the areas of knowledge considered essential for practice in the field, which encompasses the study, diagnosis, and treatment of patients with acute and chronic venous and lymphatic disorders. The American Venous Forum and the American College of Phlebology have endorsed the Core Content. PMID:25059735

  5. Imaging blood vessels and lymphatic vessels in the zebrafish.

    PubMed

    Jung, H M; Isogai, S; Kamei, M; Castranova, D; Gore, A V; Weinstein, B M

    2016-01-01

    Blood vessels supply tissues and organs with oxygen, nutrients, cellular, and humoral factors, while lymphatic vessels regulate tissue fluid homeostasis, immune trafficking, and dietary fat absorption. Understanding the mechanisms of vascular morphogenesis has become a subject of intense clinical interest because of the close association of both types of vessels with pathogenesis of a broad spectrum of human diseases. The zebrafish provides a powerful animal model to study vascular morphogenesis because of their small, accessible, and transparent embryos. These unique features of zebrafish embryos permit sophisticated high-resolution live imaging of even deeply localized vessels during embryonic development and even in adult tissues. In this chapter, we summarize various methods for blood and lymphatic vessel imaging in zebrafish, including nonvital resin injection-based or dye injection-based vessel visualization, and alkaline phosphatase staining. We also provide protocols for vital imaging of vessels using microangiography or transgenic fluorescent reporter zebrafish lines. PMID:27263409

  6. The role of the lymphatic system in cholesterol transport

    PubMed Central

    Huang, Li-Hao; Elvington, Andrew; Randolph, Gwendalyn J.

    2015-01-01

    Reverse cholesterol transport (RCT) is the pathway for removal of peripheral tissue cholesterol and involves transport of cholesterol back to liver for excretion, starting from cellular cholesterol efflux facilitated by lipid-free apolipoprotein A1 (ApoA1) or other lipidated high-density lipoprotein (HDL) particles within the interstitial space. Extracellular cholesterol then is picked up and transported through the lymphatic vasculature before entering into bloodstream. There is increasing evidence supporting a role for enhanced macrophage cholesterol efflux and RCT in ameliorating atherosclerosis, and recent data suggest that these processes may serve as better diagnostic biomarkers than plasma HDL levels. Hence, it is important to better understand the processes governing ApoA1 and HDL influx into peripheral tissues from the bloodstream, modification and facilitation of cellular cholesterol removal within the interstitial space, and transport through the lymphatic vasculature. New findings will complement therapeutic strategies for the treatment of atherosclerotic vascular disease. PMID:26388772

  7. Setaria digitata in advancing our knowledge of human lymphatic filariasis.

    PubMed

    Perumal, A N I; Gunawardene, Y I N S; Dassanayake, R S

    2016-03-01

    Setaria digitata is a filarial parasite that causes fatal cerebrospinal nematodiasis in goats, sheep and horses, resulting in substantial economic losses in animal husbandry in the tropics. Due to its close resemblance to Wuchereria bancrofti, this nematode is also frequently used as a model organism to study human lymphatic filariasis. This review highlights numerous insights into the morphological, histological, biochemical, immunological and genetic aspects of S. digitata that have broadened our understanding towards the control and eradication of filarial diseases. PMID:25924635

  8. Imported lymphatic filariasis in an Indian immigrant to iran.

    PubMed

    Kia, Eshrat Beigom; Sharifdini, Meysam; Hajjaran, Homa; Shahbazi, Ali Ehsan; Sayyad Talaie, Zahra

    2014-03-01

    Lymphatic filariasis (LF), a nematode disease transmitted by arthropod vectors, is repeatedly reported in immigrant population. This disease is not endemic in Iran; however, different species of mosquitoes, capable of transmission of parasite microfilaria, are distributed in the country. Hereby, incidental detection of an imported case of LF due to Wuchereria bancrofti in an Indian worker in Iran is reported. Identification of the case was performed based on morphological and morphometrical characteristics of microfilaria and PCR sequencing. PMID:25642273

  9. [Lymphatic cyst of the retroperitoneal space (author's transl)].

    PubMed

    De Blasi, P; Scavelli, V; Martino, D

    1979-10-01

    The authors describe an enormous lymphatic cyst, occupying cephalad and of the retroperitoneal space on the left side, half of it filled with a liquid collection and the other half being solid, displacing and compressing the stomach, spleen, and left kidney and adrenal gland (the later showing evidence of athrophy as a result of compression), Witlial, the patient had no subjective complaints and gave no objective signs of illness beyond the mere evidence of a space-occupying mass.

  10. Purinergic 2 receptor blockade prevents the responses of group IV afferents to post-contraction circulatory occlusion

    PubMed Central

    Kindig, Angela E; Hayes, Shawn G; Kaufman, Marc P

    2007-01-01

    ATP, by activating purinergic 2 (P2) receptors on group III and IV afferents, is thought to evoke the metabolic component of the exercise pressor reflex. Previously we have shown that injection of PPADS, a P2 receptor antagonist, into the arterial supply of skeletal muscle of decerebrated cats attenuated the responses of group III and IV afferents to static contraction while the muscles were freely perfused. We have now tested the hypothesis that injection of PPADS (10 mg kg−1) attenuated the responses of group III (n = 13) and group IV afferents (n = 9) to post-contraction circulatory occlusion. In the present study, we found that PPADS attenuated the group III afferent responses to static contraction during circulatory occlusion (P < 0.05). Likewise, PPADS abolished the group IV afferent responses to static contraction during occlusion (P = 0.001). During a 1 minute period of post-contraction circulatory occlusion, four of the 13 group III afferents and eight of the nine group IV afferents maintained their increased discharge. A Fischer's exact probability test revealed that more group IV afferents than group III afferents were stimulated by post-contraction circulatory occlusion (P < 0.02). In addition, the nine group IV afferents increased their mean discharge rate over baseline levels during the post-contraction circulatory occlusion period, whereas the 13 group III afferents did not (P < 0.05). PPADS abolished this post-contraction increase in discharge by the group IV afferents (P < 0.05). Our findings suggest that P2 receptors on group IV afferents play a role in evoking the metabolic component of the exercise pressor reflex. PMID:17038431

  11. Lymphatic endothelial cells are a replicative niche for Mycobacterium tuberculosis

    PubMed Central

    Lerner, Thomas R.; de Souza Carvalho-Wodarz, Cristiane; Repnik, Urska; Russell, Matthew R.G.; Borel, Sophie; Diedrich, Collin R.; Rohde, Manfred; Wainwright, Helen; Collinson, Lucy M.; Wilkinson, Robert J.; Griffiths, Gareth; Gutierrez, Maximiliano G.

    2016-01-01

    In extrapulmonary tuberculosis, the most common site of infection is within the lymphatic system, and there is growing recognition that lymphatic endothelial cells (LECs) are involved in immune function. Here, we identified LECs, which line the lymphatic vessels, as a niche for Mycobacterium tuberculosis in the lymph nodes of patients with tuberculosis. In cultured primary human LECs (hLECs), we determined that M. tuberculosis replicates both in the cytosol and within autophagosomes, but the bacteria failed to replicate when the virulence locus RD1 was deleted. Activation by IFN-γ induced a cell-autonomous response in hLECs via autophagy and NO production that restricted M. tuberculosis growth. Thus, depending on the activation status of LECs, autophagy can both promote and restrict replication. Together, these findings reveal a previously unrecognized role for hLECs and autophagy in tuberculosis pathogenesis and suggest that hLECs are a potential niche for M. tuberculosis that allows establishment of persistent infection in lymph nodes. PMID:26901813

  12. Visualisation and stereological assessment of blood and lymphatic vessels.

    PubMed

    Lokmic, Zerina; Mitchell, Geraldine M

    2011-06-01

    The physiological processes involved in tissue development and regeneration also include the parallel formation of blood and lymphatic vessel circulations which involves their growth, maturation and remodelling. Both vascular systems are also frequently involved in the development and progression of pathological conditions in tissues and organs. The blood vascular system circulates oxygenated blood and nutrients at appropriate physiological levels for tissue survival, and efficiently removes all waste products including carbon dioxide. This continuous network consists of the heart, aorta, arteries, arterioles, capillaries, post-capillary venules, venules, veins and vena cava. This system exists in an interstitial environment together with the lymphatic vascular system, including lymph nodes, which aids maintenance of body fluid balance and immune surveillance. To understand the process of vascular development, vascular network stability, remodelling and/or regression in any research model under any experimental conditions, it is necessary to clearly and unequivocally identify and quantify all elements of the vascular network. By utilising stereological methods in combination with cellular markers for different vascular cell components, it is possible to estimate parameters such as surface density and surface area of blood vessels, length density and length of blood vessels as well as absolute vascular volume. This review examines the current strategies used to visualise blood vessels and lymphatic vessels in two- and three-dimensions and the basic principles of vascular stereology used to quantify vascular network parameters.

  13. Lymphatic endothelial cells are a replicative niche for Mycobacterium tuberculosis.

    PubMed

    Lerner, Thomas R; de Souza Carvalho-Wodarz, Cristiane; Repnik, Urska; Russell, Matthew R G; Borel, Sophie; Diedrich, Collin R; Rohde, Manfred; Wainwright, Helen; Collinson, Lucy M; Wilkinson, Robert J; Griffiths, Gareth; Gutierrez, Maximiliano G

    2016-03-01

    In extrapulmonary tuberculosis, the most common site of infection is within the lymphatic system, and there is growing recognition that lymphatic endothelial cells (LECs) are involved in immune function. Here, we identified LECs, which line the lymphatic vessels, as a niche for Mycobacterium tuberculosis in the lymph nodes of patients with tuberculosis. In cultured primary human LECs (hLECs), we determined that M. tuberculosis replicates both in the cytosol and within autophagosomes, but the bacteria failed to replicate when the virulence locus RD1 was deleted. Activation by IFN-γ induced a cell-autonomous response in hLECs via autophagy and NO production that restricted M. tuberculosis growth. Thus, depending on the activation status of LECs, autophagy can both promote and restrict replication. Together, these findings reveal a previously unrecognized role for hLECs and autophagy in tuberculosis pathogenesis and suggest that hLECs are a potential niche for M. tuberculosis that allows establishment of persistent infection in lymph nodes.

  14. Regional differences in pleural lymphatic albumin concentration in sheep

    SciTech Connect

    Albertine, K.H.; Schultz, E.L.; Wiener-Kronish, J.P.; Staub, N.C.

    1987-01-01

    We used quantitative reflectance autoradiography to compare the concentration of albumin in visceral pleural lymphatics at the cranial and caudal ends of the sheep's lung in the vertical (60 degrees head-up) and horizontal (supine) positions. Twelve to fourteen hours after injecting 125I-albumin intravenously we placed four anesthetized sheep in the vertical position to establish a microvascular hydrostatic pressure gradient along the vertical height of the lung. We placed two anesthetized sheep in the horizontal position. Four hours later, we fixed the left lung and removed visceral pleural tissue blocks from the cranial and caudal ends, separated by a 15-cm distance, along the costovertebral margin. We measured the silver grain density in the pleural lymphatic autoradiograms by dark-field reflectance microspectrophotometry. In the vertical position, the lymph albumin concentration at the cranial end (top) of the lung averaged 2.5 +/- 0.4 g/dl compared with the caudal end (bottom), which averaged 1.8 +/- 0.3 g/dl. The difference (42% greater at the top than the bottom) is significant (P less than 0.05). The computed gradient in perimicrovascular interstitial albumin osmotic pressure was 0.26 +/- 0.13 cmH2O/cm lung height. There were no differences between the cranial and caudal lymphatic groups in the two horizontal sheep. We conclude that in the sheep lung there is a gradient in perimicrovascular albumin concentration due to the vertical gradient in microvascular hydrostatic pressure.

  15. [Immunologic significance of lymphatic drainage of the brain].

    PubMed

    Weller, R O; Phillips, M J; Kida, S; Zhang, E T

    1997-04-01

    Despite the evidence for immunological reactions in the human CNS, in viral encephalitis and in multiple sclerosis, connections between the brain and the immune system are poorly understood. In rodents, tracers injected into the interstitial fluid of the brain drain to the cervical lymph nodes by perivascular pathways in the brain and nasal lymphatics. Similar pathways could serve as lymphatics in the human brain. In the present study, we test the hypothesis that lymphatic drainage of the brain and cervical lymph nodes play a key role in T-cell mediated immunity of the brain. Experimental allergic encephalomyelitis (EAE) was induced in Lewis rats by the injection of guinea pig spinal cord homogenate in complete Freund's adjuvant into the foot pads. This resulted in paralysis of the hind limbs and infiltration of lymphocytes and microglial activation centred mainly on the spinal cord; little inflammation was seen in the cerebrum. When a brain wound, in the form of cryolesion, was inflicted on one cerebral hemisphere, 8 days after the induction of EAE, there was a 6-fold enhancement of EAE lesions in the brain. This enhancement was reduced by 40% cervical lymphadenectomy at the time of the cryolesion. These results suggest that cervical lymph nodes play a pivotal role in cerebral EAE and may be a major source of brain-directed lymphocytes. If similar mechanisms apply in man, study of cervical lymphocytes and their manipulation could open new therapeutic avenues for the treatment of multiple sclerosis.

  16. A brief perspective on the diverging theories of lymphatic targeting with colloids

    PubMed Central

    Siram, Karthik; Marslin, Gregory; Raghavan, Chellan Vijaya; Balakumar, Krishnamoorthy; Rahman, Habibur; Franklin, Gregory

    2016-01-01

    For targeted delivery of colloids to the lymphatic system, the colloids should efficiently reach and remain in the lymphatics for a considerable period of time. As per the current knowledge, diffusion and phagocytosis are the two mechanisms through which colloids reach the lymphatic system. Several parameters including particle size and charge have been shown to affect the direct uptake of colloids by the lymphatic system. Although many researchers attached ligands on the surface of colloids to promote phagocytosis-mediated lymphatic delivery, another school of thought suggests avoidance of phagocytosis by use of carriers like polyethylene glycol (PEG)ylated colloids to impart stealth attributes and evade phagocytosis. In this perspective, we weigh up the paradoxical theories and approaches available in the literature to draw conclusions on the conditions favorable for achieving efficient lymphatic targeting of colloids. PMID:27366065

  17. Vegfc Regulates Bipotential Precursor Division and Prox1 Expression to Promote Lymphatic Identity in Zebrafish.

    PubMed

    Koltowska, Katarzyna; Lagendijk, Anne Karine; Pichol-Thievend, Cathy; Fischer, Johanna C; Francois, Mathias; Ober, Elke A; Yap, Alpha S; Hogan, Benjamin M

    2015-12-01

    Lymphatic vessels arise chiefly from preexisting embryonic veins. Genetic regulators of lymphatic fate are known, but how dynamic cellular changes contribute during the acquisition of lymphatic identity is not understood. We report the visualization of zebrafish lymphatic precursor cell dynamics during fate restriction. In the cardinal vein, cellular commitment is linked with the division of bipotential Prox1-positive precursor cells, which occurs immediately prior to sprouting angiogenesis. Following precursor division, identities are established asymmetrically in daughter cells; one daughter cell becomes lymphatic and progressively upregulates Prox1, and the other downregulates Prox1 and remains in the vein. Vegfc drives cell division and Prox1 expression in lymphatic daughter cells, coupling signaling dynamics with daughter cell fate restriction and precursor division. PMID:26655899

  18. The lymphatic vascular system in liver diseases: its role in ascites formation.

    PubMed

    Chung, Chuhan; Iwakiri, Yasuko

    2013-06-01

    The lymphatic system is part of the circulatory system and plays a key role in normal vascular function. Its failure plays a crucial role in the development and maintenance of various diseases including liver diseases. Lymphangiogenesis (the growth of lymphatic vessels) and changes in the properties of lymphatic vessels are associated with pathogenesis of tumor metastases, ascites formation, liver fibrosis/cirrhosis and portal hypertension. Despite its significant role in liver diseases and its importance as a potential therapeutic target for those diseases, the lymphatic vascular system of the liver is poorly understood. Therefore, how the lymphatic vascular system in general and lymphangiogenesis in particular are mechanistically related to the pathogenesis and maintenance of liver diseases are largely unknown. This article summarizes: 1) the lymphatic vascular system; 2) its role in liver tumors, liver fibrosis/cirrhosis and portal hypertension; and 3) its role in ascites formation.

  19. Immunohistochemical study of the lymphatic vessels in major salivary glands of the rat.

    PubMed

    Aiyama, Shigeo; Kikuchi, Kenichiro; Takada, Kiyomi; Ikeda, Rie; Sato, Sumie; Kuroki, Jyunya

    2011-02-01

    This study was designed to examine whether lymphatic vessels are present in the lobules of major salivary glands in the rat. Immunostaining with an antibody against podoplanin, a lymphatic endothelial cell marker, was performed on sections of the submandibular, sublingual and parotid glands. Light microscopy demonstrated podoplanin-positive lymphatic vessels around the interlobular ducts and the interlobular arteries and veins in the interlobular connective tissue in all of the major salivary glands. No podoplanin-positive lymphatic vessels were found in the lobules. Electron microscopy also demonstrated lymphatic endothelial cells showing podoplanin expression only in the interlobular connective tissue. These findings suggest that the lymphatic system of the rat major salivary glands originates in the interlobular connective tissue, and not in the lobules.

  20. Lymphatics in Neurological Disorders: A Neuro-Lympho-Vascular Component of Multiple Sclerosis and Alzheimer's Disease?

    PubMed

    Louveau, Antoine; Da Mesquita, Sandro; Kipnis, Jonathan

    2016-09-01

    Lymphatic vasculature drains interstitial fluids, which contain the tissue's waste products, and ensures immune surveillance of the tissues, allowing immune cell recirculation. Until recently, the CNS was considered to be devoid of a conventional lymphatic vasculature. The recent discovery in the meninges of a lymphatic network that drains the CNS calls into question classic models for the drainage of macromolecules and immune cells from the CNS. In the context of neurological disorders, the presence of a lymphatic system draining the CNS potentially offers a new player and a new avenue for therapy. In this review, we will attempt to integrate the known primary functions of the tissue lymphatic vasculature that exists in peripheral organs with the proposed function of meningeal lymphatic vessels in neurological disorders, specifically multiple sclerosis and Alzheimer's disease. We propose that these (and potentially other) neurological afflictions can be viewed as diseases with a neuro-lympho-vascular component and should be therapeutically targeted as such. PMID:27608759

  1. A brief perspective on the diverging theories of lymphatic targeting with colloids.

    PubMed

    Siram, Karthik; Marslin, Gregory; Raghavan, Chellan Vijaya; Balakumar, Krishnamoorthy; Rahman, Habibur; Franklin, Gregory

    2016-01-01

    For targeted delivery of colloids to the lymphatic system, the colloids should efficiently reach and remain in the lymphatics for a considerable period of time. As per the current knowledge, diffusion and phagocytosis are the two mechanisms through which colloids reach the lymphatic system. Several parameters including particle size and charge have been shown to affect the direct uptake of colloids by the lymphatic system. Although many researchers attached ligands on the surface of colloids to promote phagocytosis-mediated lymphatic delivery, another school of thought suggests avoidance of phagocytosis by use of carriers like polyethylene glycol (PEG)ylated colloids to impart stealth attributes and evade phagocytosis. In this perspective, we weigh up the paradoxical theories and approaches available in the literature to draw conclusions on the conditions favorable for achieving efficient lymphatic targeting of colloids. PMID:27366065

  2. Identified proprioceptive afferents and motor rhythm entrainment in the crayfish walking system.

    PubMed

    Elson, R C; Sillar, K T; Bush, B M

    1992-03-01

    1. In crayfish, Pacifastacus leniusculus, remotion of a walking leg stretches the thoraco-coxal (TC) muscle receptor organ (TCMRO), located at the leg's articulation with the thorax. In vitro, alternate stretch and release of the fourth leg's TCMRO entrained the centrally generated rhythmic motor output to that leg, with the remotor phase of the rhythm entraining to TCMRO stretch, the promoter phase to release. This coordination of motor bursts to afferent input corresponds to that of active, rhythmic movements in vivo. 2. Entrainment was rapid in onset (stable coordination resulting within the first or second stimulus cycle) and was relatively phase-constant (whatever the stimulus frequency, during 1:1 entrainment, remotor bursts began near the onset of stretch and promotor bursts began near the onset of release). Outside the range of 1:1 entrainment, 2:1, 1:2, and 1:3 coordination ratios (rhythm:stimulus) were encountered. Resetting by phasic stimulation of the TCMRO was complete and probabilistic: effective stimuli triggered rapid transitions between the two burst phases. 3. The TCMRO is innervated by two afferents, the nonspiking S and T fibers, which generate graded depolarizing receptor potentials in response to stretch. During proprioceptive entrainment, the more phasic T fiber depolarized and hyperpolarized more rapidly or in advance of the more tonic S fiber. These receptor potentials were modified differently in the two afferents by interaction with central synaptic inputs that were phase-locked to the entrained motor rhythm. 4. Injecting slow sinusoidal current into either afferent alone could entrain motor rhythms: promoter phase bursts were entrained to depolarization of the S fiber or hyperpolarization of the T fiber, whereas the converse response was obtained for remotor phase bursts. 5. During proprioceptive entrainment, tonic hyperpolarization of the S fiber weakened entrained promotor bursts and allowed remotor burst durations to increase

  3. Basement membrane protein distribution in LYVE-1-immunoreactive lymphatic vessels of normal tissues and ovarian carcinomas.

    PubMed

    Vainionpää, Noora; Bützow, Ralf; Hukkanen, Mika; Jackson, David G; Pihlajaniemi, Taina; Sakai, Lynn Y; Virtanen, Ismo

    2007-05-01

    The endothelial cells of blood vessels assemble basement membranes that play a role in vessel formation, maintenance and function, and in the migration of inflammatory cells. However, little is known about the distribution of basement membrane constituents in lymphatic vessels. We studied the distribution of basement membrane proteins in lymphatic vessels of normal human skin, digestive tract, ovary and, as an example of tumours with abundant lymphatics, ovarian carcinomas. Basement membrane proteins were localized by immunohistochemistry with monoclonal antibodies, whereas lymphatic capillaries were detected with antibodies to the lymphatic vessel endothelial hyaluronan receptor-1, LYVE-1. In skin and ovary, fibrillar immunoreactivity for the laminin alpha4, beta1, beta2 and gamma1 chains, type IV and XVIII collagens and nidogen-1 was found in the basement membrane region of the lymphatic endothelium, whereas also heterogeneous reactivity for the laminin alpha5 chain was detected in the digestive tract. Among ovarian carcinomas, intratumoural lymphatic vessels were found especially in endometrioid carcinomas. In addition to the laminin alpha4, beta1, beta2 and gamma1 chains, type IV and XVIII collagens and nidogen-1, carcinoma lymphatics showed immunoreactivity for the laminin alpha5 chain and Lutheran glycoprotein, a receptor for the laminin alpha5 chain. In normal lymphatic capillaries, the presence of primarily alpha4 chain laminins may therefore compromise the formation of endothelial basement membrane, as these truncated laminins lack one of the three arms required for efficient network assembly. The localization of basement membrane proteins adjacent to lymphatic endothelia suggests a role for these proteins in lymphatic vessels. The distribution of the laminin alpha5 chain and Lutheran glycoprotein proposes a difference between normal and carcinoma lymphatic capillaries.

  4. Targeting primary afferent nerves for novel antitussive therapy.

    PubMed

    Undem, Bradley J; Carr, Michael J

    2010-01-01

    The best available data support the hypothesis that there are at least two types of vagal nerves responsible for initiating coughing reflexes. One type of nerve conducts action potentials in the A-range and is characterized by rapidly adapting responses to mechanical probing or acidification of the large airway epithelium. Stimulation of these nerves can evoke cough in unconscious experimental animals and humans. These nerves are important in immediate cough evoked by aspiration and as such perform a critical role in airway defense. The other type of primary afferent nerve involved in cough is the vagal C-fiber. Inhalation of selective C-fiber stimulants leads to cough only in conscious animals. In clinical studies, inhalation of a low concentration of a C-fiber stimulant causes an irritating, itchy urge-to-cough sensation that mimics the urge-to-cough sensations associated with respiratory tract infection, post-infection, gastroesophageal reflux disorders, and inflammatory airway diseases. Here we discuss the recent advances in sensory neurobiology that allow for the targeting of vagal C-fibers for novel antitussive therapy. No attempts are made to be all-inclusive with respect to the numerous possible molecular targets being considered to accomplish this goal. Rather, two general strategies are discussed: decreasing generator potential amplitude and decreasing the efficiency by which a generator potential evokes action-potential discharge. For the first category we focus on two targets, transient receptor potential vanilloid 1 and transient receptor potential A1. For the latter category we focus on recent advances in voltage-gated sodium (Na(V)) channel biology.

  5. NEUROTROPHIN SELECTIVITY IN ORGANIZING TOPOGRAPHIC REGENERATION OF NOCICEPTIVE AFFERENTS

    PubMed Central

    Kelamangalath, Lakshmi; Tang, Xiaoqing; Bezik, Kathleen; Sterling, Noelle; Son, Young-Jin; Smith, George M.

    2015-01-01

    Neurotrophins represent some of the best candidates to enhance regeneration. In the current study, we investigated the effects of artemin, a member of the glial derived neurotrophic factor (GDNF) family, on sensory axon regeneration following a lumbar dorsal root injury and compared these effects with that observed after either NGF or GDNF expression in the rat spinal cord. Unlike previously published data, artemin failed to induce regeneration of large-diameter myelinated sensory afferents when expressed within either the spinal cord or DRG. However, artemin or NGF induced regeneration of calcitonin gene related peptide positive (CGRP+) axons only when expressed within the spinal cord. Accordingly, artemin or NGF enhanced recovery of only nociceptive behavior and showed a cFos distribution similar to the topography of regenerating axons. Artemin and GDNF signaling requires binding to different co-receptors (GFRα3 or GFRα1, respectively) prior to binding to the signaling receptor, cRet. Approximately 70% of DRG neurons express cRet, but only 35% express either co-receptor. To enhance artemin-induced regeneration, we co-expressed artemin with either GFRα3 or GDNF. Co-expression of artemin and GFRα3 only slightly enhanced regeneration of IB4+ non-peptidergic nociceptive axons, but not myelinated axons. Interestingly, this co-expression also disrupted the ability of artemin to produce topographic targeting and lead to significant increases in cFos immunoreactivity within the deep dorsal laminae. This study failed to demonstrate artemin-induced regeneration of myelinated axons, even with co-expression of GFR-α3, which only promoted mistargeted regeneration. PMID:26054884

  6. Endogenous bradykinin activates ischaemically sensitive cardiac visceral afferents through kinin B2 receptors in cats

    PubMed Central

    Tjen-A-Looi, Stephanie C; Pan, Hui-Lin; Longhurst, John C

    1998-01-01

    Activity of ischaemically sensitive cardiac visceral afferents during myocardial ischaemia induces both angina and cardiovascular reflexes. Increased production of bradykinin (BK) and cyclo-oxygenase products (i.e. prostaglandins (PGs)) occurs during myocardial ischaemia. However, the role of these agents in activation of ischaemically sensitive cardiac afferents has not been established. The present study tested the hypothesis that BK produced during ischaemia activates cardiac afferents through kinin B2 receptors. Single-unit activity of cardiac afferents innervating the left ventricle was recorded from the left thoracic sympathetic chain (T1–T4) of anaesthetized cats. Ischaemically sensitive cardiac afferents were identified according to their response to 5 min of myocardial ischaemia. The mechanism of BK in activation of ischaemically sensitive cardiac afferents was determined by injection of BK (1 μg kg−1 i.a.), des-Arg9-BK (1 μg kg−1 i.a., a specific kinin B1 receptor agonist), kinin B2 receptor antagonists: HOE140 (30 μg kg−1 i.v.) and NPC-17731 (40 μg kg−1 i.v.), cyclo-oxygenase inhibition with indomethacin (5 mg kg−1 i.v.) and NPC-17731 (40 μg kg−1 i.v.) after pretreatment with indomethacin (5 mg kg−1 i.v.). We observed that BK increased the discharge rate of all eleven ischaemically sensitive cardiac afferents from 0.39 ± 0.12 to 1.47 ± 0.37 impulses s−1 (P < 0.05). Conversely, des-Arg9-BK did not significantly increase the activity of eleven ischaemically sensitive fibres (0.58 ± 0.02 vs. 0.50 ± 0.18 impulses s−1). HOE140 significantly attenuated the response of twelve afferents to ischaemia (0.61 ± 0.22 to 1.85 ± 0.5 vs. 0.53 ± 0.16 to 1.09 ± 0.4 impulses s−1). NPC-17731, another kinin B2 receptor antagonist, had similar inhibitory effects on six other ischaemically sensitive cardiac afferents (0.35 ± 0.14 to 1.19 ± 0.29 vs. 0.22 ± 0.08 to 0.23 ± 0.07 impulses s−1). Indomethacin significantly reduced the

  7. Restoration of lymphatic function rescues obesity in Prox1-haploinsufficient mice

    PubMed Central

    Proulx, Steven T.; Dillard, Miriam E.; Johnson, Nicole; Detmar, Michael

    2016-01-01

    Prox1 heterozygous mice have a defective lymphatic vasculature and develop late-onset obesity. Chyle abnormally leaks from those vessels, accumulates in the surrounding tissues, and causes an increase in adipose tissue. We characterized the lymphatics of Prox1+/– mice to determine whether the extent of obesity correlated with the severity of lymphatic defects. The lymphatic vasculature in Prox1+/– mice exhibited reduced tracer clearance from the ear skin, dysfunctional perfusion of the lower legs, and reduced tracer uptake into the deep lymphatic collectors during mechanostimulation prior to the onset of obesity. Ear lymphatic vessels and leg collectors in Prox1+/– mice were disorganized and irregular, further confirming that defective lymphatic vessels are associated with obesity in Prox1+/– mice. We now provide conclusive in vivo evidence that demonstrates that leaky lymphatics mediate obesity in Prox1+/– mice, as restoration of lymphatic vasculature function was sufficient to rescue the obesity features in Prox1+/– mice. Finally, depth-lipomic profiling of lymph contents showed that free fatty acids induce adipogenesis in vitro. PMID:26973883

  8. A tale of two models: mouse and zebrafish as complementary models for lymphatic studies.

    PubMed

    Kim, Jun-Dae; Jin, Suk-Won

    2014-07-01

    Lymphatic vessels provide essential roles in maintaining fluid homeostasis and lipid absorption. Dysfunctions of the lymphatic vessels lead to debilitating pathological conditions, collectively known as lymphedema. In addition, lymphatic vessels are a critical moderator for the onset and progression of diverse human diseases including metastatic cancer and obesity. Despite their clinical importance, there is no currently effective pharmacological therapy to regulate functions of lymphatic vessels. Recent efforts to manipulate the Vascular Endothelial Growth Factor-C (VEGFC) pathway, which is arguably the most important signaling pathway regulating lymphatic endothelial cells, to alleviate lymphedema yielded largely mixed results, necessitating identification of new targetable signaling pathways for therapeutic intervention for lymphedema. Zebrafish, a relatively new model system to investigate lymphatic biology, appears to be an ideal model to identify novel therapeutic targets for lymphatic biology. In this review, we will provide an overview of our current understanding of the lymphatic vessels in vertebrates, and discuss zebrafish as a promising in vivo model to study lymphatic vessels.

  9. A New Technique to Map the Lymphatic Distribution and Alignment of the Penis.

    PubMed

    Long, Liu Yan; Qiang, Pan Fu; Ling, Tao; Wei, Zhang Yan; Long, Zhang Yu; Shan, Meng; Rong, Li Shi; Li, Li Hong

    2015-08-01

    The present study was to examine the distribution of lymphatic vessels in the penis of normal adult males, which could provide an anatomical basis for improvement of incisions in penile lengthening surgery, and may also help to prevent postoperative refractory edema. Thirteen normal adult male volunteers were recruited for this study. Contrast agent was injected subcutaneously in the foreskin of the penis, and after two minutes magnetic resonance lymphangiography (MRL) was performed. The acquired magnetic resonance images were analyzed to determine the changes in the number and diameter of lymphatic vessels in different parts of the penis. Maximum intensity projections (MIP) and materializes interactive medical image control system (MIMICS) were applied to analyze the overall distribution of lymphatic vessels in the penis. Magnetic resonance imaging (MRI) showed that the lymphatic vessels were in conspicuous contrast with surrounding tissues and could be clearly identified. Penile lymphatic vessels were clearly visible in the root of the penis. At the junction of the penis and the abdominal wall, all lymphatic vessels were found to be concentrated in the dorsal part of the penis. MIP two-dimensional reconstruction showed that the overall distribution of relatively large lymphatic vessels in the dorsal and ventral parts of the penis could be seen clearly on bilateral 45° position, but not inside the abdominal wall because some of lymphatic vessels were overlapped by other tissues in the abdomen. MIMICS three-dimensional reconstruction was able to reveal the overall spatial distribution of lymphatic vessels in the penis from any angle. The reconstruction results showed that there were 1-2 main lymphatic vessels on the root of dorsal penis, which coursed along the cavernous to the first physiological curvature of the penis. Lymphatic vessels merged on both sides of the ventral penis. At the root of the penis, lymphatic vessels gradually coursed to the dorsal surface

  10. Advanced drug delivery to the lymphatic system: lipid-based nanoformulations.

    PubMed

    Ali Khan, Arshad; Mudassir, Jahanzeb; Mohtar, Noratiqah; Darwis, Yusrida

    2013-01-01

    The delivery of drugs and bioactive compounds via the lymphatic system is complex and dependent on the physiological uniqueness of the system. The lymphatic route plays an important role in transporting extracellular fluid to maintain homeostasis and in transferring immune cells to injury sites, and is able to avoid first-pass metabolism, thus acting as a bypass route for compounds with lower bioavailability, ie, those undergoing more hepatic metabolism. The lymphatic route also provides an option for the delivery of therapeutic molecules, such as drugs to treat cancer and human immunodeficiency virus, which can travel through the lymphatic system. Lymphatic imaging is useful in evaluating disease states and treatment plans for progressive diseases of the lymph system. Novel lipid-based nanoformulations, such as solid lipid nanoparticles and nanostructured lipid carriers, have unique characteristics that make them promising candidates for lymphatic delivery. These formulations are superior to colloidal carrier systems because they have controlled release properties and provide better chemical stability for drug molecules. However, multiple factors regulate the lymphatic delivery of drugs. Prior to lymphatic uptake, lipid-based nanoformulations are required to undergo interstitial hindrance that modulates drug delivery. Therefore, uptake and distribution of lipid-based nanoformulations by the lymphatic system depends on factors such as particle size, surface charge, molecular weight, and hydrophobicity. Types of lipid and concentration of the emulsifier are also important factors affecting drug delivery via the lymphatic system. All of these factors can cause changes in intermolecular interactions between the lipid nanoparticle matrix and the incorporated drug, which in turn affects uptake of drug into the lymphatic system. Two lipid-based nanoformulations, ie, solid lipid nanoparticles and nanostructured lipid carriers, have been administered via multiple routes

  11. Advanced drug delivery to the lymphatic system: lipid-based nanoformulations

    PubMed Central

    Khan, Arshad Ali; Mudassir, Jahanzeb; Mohtar, Noratiqah; Darwis, Yusrida

    2013-01-01

    The delivery of drugs and bioactive compounds via the lymphatic system is complex and dependent on the physiological uniqueness of the system. The lymphatic route plays an important role in transporting extracellular fluid to maintain homeostasis and in transferring immune cells to injury sites, and is able to avoid first-pass metabolism, thus acting as a bypass route for compounds with lower bioavailability, ie, those undergoing more hepatic metabolism. The lymphatic route also provides an option for the delivery of therapeutic molecules, such as drugs to treat cancer and human immunodeficiency virus, which can travel through the lymphatic system. Lymphatic imaging is useful in evaluating disease states and treatment plans for progressive diseases of the lymph system. Novel lipid-based nanoformulations, such as solid lipid nanoparticles and nanostructured lipid carriers, have unique characteristics that make them promising candidates for lymphatic delivery. These formulations are superior to colloidal carrier systems because they have controlled release properties and provide better chemical stability for drug molecules. However, multiple factors regulate the lymphatic delivery of drugs. Prior to lymphatic uptake, lipid-based nanoformulations are required to undergo interstitial hindrance that modulates drug delivery. Therefore, uptake and distribution of lipid-based nanoformulations by the lymphatic system depends on factors such as particle size, surface charge, molecular weight, and hydrophobicity. Types of lipid and concentration of the emulsifier are also important factors affecting drug delivery via the lymphatic system. All of these factors can cause changes in intermolecular interactions between the lipid nanoparticle matrix and the incorporated drug, which in turn affects uptake of drug into the lymphatic system. Two lipid-based nanoformulations, ie, solid lipid nanoparticles and nanostructured lipid carriers, have been administered via multiple routes

  12. The role of the lymphatic system in endometriosis: a comprehensive review of the literature.

    PubMed

    Jerman, Laila F; Hey-Cunningham, Alison J

    2015-03-01

    Endometriosis is a benign gynecological disorder characterized by the presence of tissue resembling the endometrium in locations outside the uterus. The pathogenesis of endometriosis is still unknown; however, it is believed that the lymphatic system plays major roles in the development and progression of the disease. The lymphatic dissemination theory has been proposed to explain the presence of endometrial and/or endometriotic tissue in lymphatic vessels, lymph nodes, and rare sites, as well as high reoccurrence rates following treatment. Despite the importance of the lymphatic system in many aspects of endometriosis, there has been no previous thorough scientific update on its role in the disease. A review of scientific literature on the lymphatic system, lymphangiogenesis, and immunological changes associated with endometriosis was conducted. Lymphangiogenic potential is disturbed and lymphatic vessel density increased in the eutopic endometrium of women with endometriosis, likely promoting the entry of endometrial tissues into the lymphatic circulation. Endometriotic lesions and endometrial-like cells are present in uterine-draining nodes and various other pelvic lymph nodes. Immune responses are impaired in uterine-draining nodes, likely favoring the survival of endometrial cells and lesion establishment. In addition, lymphangiogenesis in endometriotic lesions may contribute to lesion growth and persistence, and promote the spread of endometrial cells to draining lymph nodes. The evidence reviewed in this paper supports the theory of lymphatic dissemination of endometriosis and highlights the roles of the lymphatic system in the pathogenesis and persistence of endometriosis. Understanding these roles is crucial for establishment of novel therapeutic approaches.

  13. A transgenic Prox1-Cre-tdTomato reporter mouse for lymphatic vessel research.

    PubMed

    Bianchi, Roberta; Teijeira, Alvaro; Proulx, Steven T; Christiansen, Ailsa J; Seidel, Catharina D; Rülicke, Thomas; Mäkinen, Taija; Hägerling, René; Halin, Cornelia; Detmar, Michael

    2015-01-01

    The lymphatic vascular system plays an active role in immune cell trafficking, inflammation and cancer spread. In order to provide an in vivo tool to improve our understanding of lymphatic vessel function in physiological and pathological conditions, we generated and characterized a tdTomato reporter mouse and crossed it with a mouse line expressing Cre recombinase under the control of the lymphatic specific promoter Prox1 in an inducible fashion. We found that the tdTomato fluorescent signal recapitulates the expression pattern of Prox1 in lymphatic vessels and other known Prox1-expressing organs. Importantly, tdTomato co-localized with the lymphatic markers Prox1, LYVE-1 and podoplanin as assessed by whole-mount immunofluorescence and FACS analysis. The tdTomato reporter was brighter than a previously established red fluorescent reporter line. We confirmed the applicability of this animal model to intravital microscopy of dendritic cell migration into and within lymphatic vessels, and to fluorescence-activated single cell analysis of lymphatic endothelial cells. Additionally, we were able to describe the early morphological changes of the lymphatic vasculature upon induction of skin inflammation. The Prox1-Cre-tdTomato reporter mouse thus shows great potential for lymphatic research.

  14. Central projections of the wing afferents in the hawkmoth, Agrius convolvuli.

    PubMed

    Ando, Noriyasu; Wang, Hao; Shirai, Koji; Kiguchi, Kenji; Kanzaki, Ryohei

    2011-11-01

    Flight behaviors in various insect species are closely correlated with their mechanical and neuronal properties. Compared to locusts and flies which have been intensively studied, moths have "intermediate" properties in terms of the neurogenic muscle activations, power generation by indirect muscles, and two-winged-insect-like flapping behavior. Despite these unique characteristics, little is known about the neuronal mechanisms of flight control in moths. We investigated projections of the wing mechanosensory afferents in the central nervous system (CNS) of the hawkmoth, Agrius convolvuli, because the mechanosensory proprioceptive feedback has an essential role for flight control and would be presumably optimized for insect species. We conducted anterograde staining of nine afferent nerves from the fore- and hindwings. All of these afferents projected into the prothoracic, mesothoracic and metathoracic ganglia (TG1, 2 and 3) and had ascending fibers to the head ganglia. Prominent projection areas in the TG1-3 and suboesophageal ganglion (SOG) were common between the forewing, hindwing and contralateral forewing afferents, suggesting that information from different wings are converged at multiple levels presumably for coordinating wing flapping. On the other hand, differences of projections between the fore- and hindwing afferents were observed especially in projection areas of the tegulae in the TG1 and contralateral projections of the anterior forewing nerve in the TGs and SOG, which would reflect functional differences between corresponding mechanoreceptors on each wing. Afferents comprising groups of the campaniform sensilla at the wing bases had prominent ascending pathways to the SOG, resembling the head-neck motor system for gaze control in flies. Double staining of the wing afferents and flight or neck motoneurons also indicated potential connectivity between them. Our results suggest multiple roles of the wing proprioceptive feedback for flight and provide

  15. Functional analysis of ultra high information rates conveyed by rat vibrissal primary afferents

    PubMed Central

    Chagas, André M.; Theis, Lucas; Sengupta, Biswa; Stüttgen, Maik C.; Bethge, Matthias; Schwarz, Cornelius

    2013-01-01

    Sensory receptors determine the type and the quantity of information available for perception. Here, we quantified and characterized the information transferred by primary afferents in the rat whisker system using neural system identification. Quantification of “how much” information is conveyed by primary afferents, using the direct method (DM), a classical information theoretic tool, revealed that primary afferents transfer huge amounts of information (up to 529 bits/s). Information theoretic analysis of instantaneous spike-triggered kinematic stimulus features was used to gain functional insight on “what” is coded by primary afferents. Amongst the kinematic variables tested—position, velocity, and acceleration—primary afferent spikes encoded velocity best. The other two variables contributed to information transfer, but only if combined with velocity. We further revealed three additional characteristics that play a role in information transfer by primary afferents. Firstly, primary afferent spikes show preference for well separated multiple stimuli (i.e., well separated sets of combinations of the three instantaneous kinematic variables). Secondly, neurons are sensitive to short strips of the stimulus trajectory (up to 10 ms pre-spike time), and thirdly, they show spike patterns (precise doublet and triplet spiking). In order to deal with these complexities, we used a flexible probabilistic neuron model fitting mixtures of Gaussians to the spike triggered stimulus distributions, which quantitatively captured the contribution of the mentioned features and allowed us to achieve a full functional analysis of the total information rate indicated by the DM. We found that instantaneous position, velocity, and acceleration explained about 50% of the total information rate. Adding a 10 ms pre-spike interval of stimulus trajectory achieved 80–90%. The final 10–20% were found to be due to non-linear coding by spike bursts. PMID:24367295

  16. The unsilent majority-TRPV1 drives "spontaneous" transmission of unmyelinated primary afferents within cardiorespiratory NTS.

    PubMed

    Andresen, Michael C; Hofmann, Mackenzie E; Fawley, Jessica A

    2012-12-15

    Cranial primary afferent sensory neurons figure importantly in homeostatic control of visceral organ systems. Of the two broad classes of visceral afferents, the role of unmyelinated or C-type class remains poorly understood. This review contrasts key aspects of peripheral discharge properties of C-fiber afferents and their glutamate transmission mechanisms within the solitary tract nucleus (NTS). During normal prevailing conditions, most information arrives at the NTS through myelinated A-type nerves. However, most of visceral afferent axons (75-90%) in NTS are unmyelinated, C-type axons. Centrally, C-type solitary tract (ST) afferent terminals have presynaptic transient receptor potential vanilloid type 1 (TRPV1) receptors. Capsaicin activation of TRPV1 blocks phasic or synchronous release of glutamate but facilitates release of glutamate from a separate pool of vesicles. This TRPV1-operated pool of vesicles is active at normal temperatures and is responsible for actively driving a 10-fold higher release of glutamate at TRPV1 compared with TRPV1- terminals even in the absence of afferent action potentials. This novel TRPV1 mechanism is responsible for an additional asynchronous release of glutamate that is not present in myelinated terminals. The NTS is rich with presynaptic G protein-coupled receptors, and the implications of TRPV1-operated glutamate offer unique targets for signaling in C-type sensory afferent terminals from neuropeptides, inflammatory mediators, lipid metabolites, cytokines, and cannabinoids. From a homeostatic view, this combination could have broad implications for integration in chronic pathological disturbances in which the numeric dominance of C-type endings and TRPV1 would broadly disturb multisystem control mechanisms.

  17. Capsaicin-sensitive vagal afferent neurons contribute to the detection of pathogenic bacterial colonization in the gut.

    PubMed

    Riley, T P; Neal-McKinney, J M; Buelow, D R; Konkel, M E; Simasko, S M

    2013-04-15

    Vagal activation can reduce inflammation and disease activity in various animal models of intestinal inflammation via the cholinergic anti-inflammatory pathway. In the current model of this pathway, activation of descending vagal efferents is dependent on a signal initiated by stimulation of vagal afferents. However, little is known about how vagal afferents are activated, especially in the context of subclinical or clinical pathogenic bacterial infection. To address this question, we first determined if selective lesions of capsaicin-sensitive vagal afferents altered c-Fos expression in the nucleus of the solitary tract (nTS) after mice were inoculated with either Campylobacter jejuni or Salmonella typhimurium. Our results demonstrate that the activation of nTS neurons by intraluminal pathogenic bacteria is dependent on intact, capsaicin sensitive vagal afferents. We next determined if inflammatory mediators could cause the observed increase in c-Fos expression in the nTS by a direct action on vagal afferents. This was tested by the use of single-cell calcium measurements in cultured vagal afferent neurons. We found that tumor necrosis factor alpha (TNFα) and lipopolysaccharide (LPS) directly activate cultured vagal afferent neurons and that almost all TNFα and LPS responsive neurons were sensitive to capsaicin. We conclude that activation of the afferent arm of the parasympathetic neuroimmune reflex by pathogenic bacteria in the gut is dependent on capsaicin sensitive vagal afferent neurons and that the release of inflammatory mediators into intestinal tissue can be directly sensed by these neurons. PMID:23481698

  18. Capsaicin-sensitive vagal afferent neurons contribute to the detection of pathogenic bacterial colonization in the gut

    PubMed Central

    Riley, T.P.; Neal-McKinney, J.M.; Buelow, D.R.; Konkel, M.E.; Simasko, S.M.

    2014-01-01

    Vagal activation can reduce inflammation and disease activity in various animal models of intestinal inflammation via the cholinergic anti-inflammatory pathway. In the current model of this pathway, activation of descending vagal efferents is dependent on a signal initiated by stimulation of vagal afferents. However, little is known about how vagal afferents are activated, especially in the context of subclinical or clinical pathogenic bacterial infection. To address this question, we first determined if selective lesions of capsaicin-sensitive vagal afferents altered c-Fos expression in the nucleus of the solitary tract (nTS) after mice were inoculated with either Campylobacter jejuni or Salmonella typhimurium. Our results demonstrate that the activation of nTS neurons by intraluminal pathogenic bacteria is dependent on intact, capsaicin sensitive vagal afferents. We next determined if inflammatory mediators could cause the observed increase in c-Fos expression in the nTS by a direct action on vagal afferents. This was tested by the use of single-cell calcium measurements in cultured vagal afferent neurons. We found that tumor necrosis factor alpha (TNFα) and lipopolysaccharide (LPS) directly activate cultured vagal afferent neurons and that almost all TNFα and LPS responsive neurons were sensitive to capsaicin. We conclude that activation of the afferent arm of the parasympathetic neuroimmune reflex by pathogenic bacteria in the gut is dependent on capsaicin sensitive vagal afferent neurons and that the release of inflammatory mediators into intestinal tissue can be directly sensed by these neurons. PMID:23481698

  19. Structure-function relationships in rat medullary and cervical dorsal horns. I. Trigeminal primary afferents.

    PubMed

    Jacquin, M F; Renehan, W E; Mooney, R D; Rhoades, R W

    1986-06-01

    Intracellular recording and horseradish peroxidase (HRP) labeling were used to examine structure-function relationships in the medullary dorsal horn (MDH) and rostral cervical dorsal horn. In Nembutal-anesthetized rats, 78 trigeminal (V) primary afferent fibers were physiologically characterized and injected with HRP. Axons were sufficiently well stained to reconstruct all of their collaterals in the MDH. Many also extended into the cervical dorsal horn. Except for four axons, which responded best to noxious stimuli, all responded at short (mean = 0.50 ms) latencies to V ganglion shocks and to innocuous stimulation. Forty-five of our recovered fibers were associated with facial vibrissae and responded in either a rapidly adapting, slowly adapting type I, slowly adapting type IIa, or slowly adapting type IIb fashion. The adequate stimuli consisted of either slow deflection, high-velocity deflection, or a noxious pinch of the vibrissa follicle. The collaterals of all of the above-described mystacial vibrissa primary afferents proceeded directly to their region of arborization in a plane perpendicular to the lateral border of the medulla to collectively form a largely continuous, circumscribed terminal column. This longitudinally oriented column of terminal and en passant boutons angled from lamina V rostrally to lamina III caudally. In the magnocellular laminae of the MDH, all mystacial vibrissa primary afferents gave rise to similarly shaped arbors, regardless of their functional classification. While morphological variability was observed both within and between individual axons, variance between functional classes was no greater than that within a class. Moreover, number of collaterals, number of boutons, or bouton size did not distinguish functional classes. Nonmystacial vibrissa afferent arbors, with more caudal peripheral fields, had their primary arbor focus in C1 and C2 dorsal horn. These arbors had relatively little rostrocaudal overlap with mystacial

  20. Ventral hippocampal afferents to the nucleus accumbens regulate susceptibility to depression

    PubMed Central

    Bagot, Rosemary C.; Parise, Eric M.; Peña, Catherine J.; Zhang, Hong-Xing; Maze, Ian; Chaudhury, Dipesh; Persaud, Brianna; Cachope, Roger; Bolaños-Guzmán, Carlos A.; Cheer, Joseph; Deisseroth, Karl; Han, Ming-Hu; Nestler, Eric J.

    2015-01-01

    Enhanced glutamatergic transmission in the nucleus accumbens (NAc), a region critical for reward and motivation, has been implicated in the pathophysiology of depression; however, the afferent source of this increased glutamate tone is not known. The NAc receives glutamatergic inputs from the medial prefrontal cortex (mPFC), ventral hippocampus (vHIP) and basolateral amygdala (AMY). Here, we demonstrate that glutamatergic vHIP afferents to NAc regulate susceptibility to chronic social defeat stress (CSDS). We observe reduced activity in vHIP in mice resilient to CSDS. Furthermore, attenuation of vHIP-NAc transmission by optogenetic induction of long-term depression is pro-resilient, whereas acute enhancement of this input is pro-susceptible. This effect is specific to vHIP afferents to the NAc, as optogenetic stimulation of either mPFC or AMY afferents to the NAc is pro-resilient. These data indicate that vHIP afferents to NAc uniquely regulate susceptibility to CSDS, highlighting an important, novel circuit-specific mechanism in depression. PMID:25952660

  1. Cutaneous afferent input does not modulate motor intracortical inhibition in ageing men.

    PubMed

    Smith, Ashleigh E; Ridding, Michael C; Higgins, Ryan D; Wittert, Gary A; Pitcher, Julia B

    2011-11-01

    Afferent input has been shown to be a powerful modulator of cortical inhibition. Such modulation is likely to be important for the control of ongoing movement, but may also play a role in facilitating neuroplastic reorganisation. Human motor control and neuroplasticity both decline with ageing, whereas the efficacy of short-interval intracortical inhibition (SICI) appears not to. We examined if ageing alters the efficacy of afferent modulation of SICI. Previously, electrical cutaneous stimulation of a finger has been shown to reduce SICI in the motor cortices of young adults. Paired-pulse transcranial magnetic stimulation was used to assess SICI in the cortical representation of the first dorsal interosseous muscle. SICI was assessed separately under two conditions: with and without prior afferent input from electrical cutaneous stimulation of the index finger. Fifteen 'young' (20.1 ± 2.1 years) and 15 'old' male humans (65.5 ± 3.9 years) were studied. SICI did not differ when young and old males were compared. However, when preceded by electrical cutaneous finger stimulation, SICI was reduced in young men but not old men. Reflex testing indicated preservation of the afferent volley to the cortex. These findings suggest that a contributing factor in the decline of motor function, and possibly neuroplasticity, with ageing is loss of SICI modulation, probably due to altered cortical sensorimotor integration of afferent input.

  2. Paraventricular nucleus is involved in the central pathway of adipose afferent reflex in rats.

    PubMed

    Shi, Zhen; Wang, Yuan-Fang; Wang, Gui-Hua; Wu, Yu-Long; Ma, Chun-Lei

    2016-05-01

    Increasing evidence indicates a link between sympathetic nervous system activation and obesity, but the underlying mechanisms remain elusive. The adipose afferent reflex (AAR) is a sympathoexcitatory reflex that is activated by afferent neurotransmission from the white adipose tissue (WAT). This study aimed to investigate whether the hypothalamic paraventricular nucleus (PVH) is an important component of the central neurocircuitry of the AAR. In anesthetized rats, the discharge activity of individual PVH neurons was recorded in vivo. Activation of WAT afferents was initiated by capsaicin injection, and the AAR was evaluated by monitoring renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) responses. The responses of PVH neurons to activation of WAT afferents were evaluated by c-fos immunoreactivity and the discharge activity of individual PVH neurons, which was recorded using extracellular single-unit recording. After activation of WAT afferents, both individual PVH neuron discharge activity and c-fos immunoreactivity increased. Bilateral selective lesions of the neurons in the PVH with kainic acid abolished the AAR. These results indicate that PVH is an important component of the central neurocircuitry of the AAR. PMID:26963333

  3. Inhibition of repulsive guidance molecule, RGMa, increases afferent synapse formation with auditory hair cells.

    PubMed

    Brugeaud, Aurore; Tong, Mingjie; Luo, Li; Edge, Albert S B

    2014-04-01

    The peripheral fibers that extend from auditory neurons to hair cells are sensitive to damage, and replacement of the fibers and their afferent synapse with hair cells would be of therapeutic interest. Here, we show that RGMa, a repulsive guidance molecule previously shown to play a role in the development of the chick visual system, is expressed in the developing, newborn, and mature mouse inner ear. The effect of RGMa on synaptogenesis between afferent neurons and hair cells, from which afferent connections had been removed, was assessed. Contact of neural processes with hair cells and elaboration of postsynaptic densities at sites of the ribbon synapse were increased by treatment with a blocking antibody to RGMa, and pruning of auditory fibers to achieve the mature branching pattern of afferent neurons was accelerated. Inhibition by RGMa could thus explain why auditory neurons have a low capacity to regenerate peripheral processes: postnatal spiral ganglion neurons retain the capacity to send out processes that respond to signals for synapse formation, but expression of RGMa postnatally appears to be detrimental to regeneration of afferent hair cell innervation and antagonizes synaptogenesis. Increased synaptogenesis after inhibition of RGMa suggests that manipulation of guidance or inhibitory factors may provide a route to increase formation of new synapses at deafferented hair cells.

  4. Unpredictability of lymphatic drainage patterns in melanoma patients.

    PubMed

    Statius Muller, Markwin G; Hennipman, Feitse A; van Leeuwen, Paul A M; Pijpers, Rik; Vuylsteke, Ronald J; Meijer, Sybren

    2002-02-01

    We analysed the localisations of sentinel nodes (SN) found with the SN procedure to compare these sites with those that would have been predicted by conventional clinical descriptions of cutaneous lymphatic drainage. We assessed the surplus value of performing the SN procedure in melanoma patients who underwent regional nodal surgery. The SN procedure was performed in 348 patients with melanomas who were referred to our institute between 1993 and 1999. The localisations of the melanomas with the corresponding SNs were meticulously recorded on drawings of the human body and grouped according to the conventional descriptions. Predictability of lymph drainage was defined as the percentage of melanomas whose draining pattern was to the ipsilateral nearest basin, without simultaneous drainage to other basins or to an interval node. In all patients the SN procedure visualised at least one SN. We found 410 lymphatic basins in 347 patients. These basins included basins that could not have been predicted by the conventional clinical descriptions, such as multiple basins and contralateral drainage sites. For the head/neck region, SNs could be found in any of the basins described in the literature. The trunk's drainage predictability depended strongly on the melanoma localisation, ranging from 0% in the midline to 92% in one of the upper quadrants. The lower extremities had a high predictability of almost 100%, and predictability of drainage for the upper extremities ranged from 77% to 100%. In total, 34% of the patients had a cutaneous lymphatic drainage that was unpredictable, either totally or partially. We therefore conclude that an SN procedure is indispensable if the drainage site(s) are to be accurately identified. PMID:11930886

  5. Lymphatic mapping and sentinel lymphadenectomy for breast cancer.

    PubMed Central

    Giuliano, A E; Kirgan, D M; Guenther, J M; Morton, D L

    1994-01-01

    OBJECTIVE: The authors report the feasibility and accuracy of intraoperative lymphatic mapping with sentinel lymphadenectomy in patients with breast cancer. SUMMARY BACKGROUND DATA: Axillary lymph node dissection (ALND) for breast cancer generally is accepted for its staging and prognostic value, but the extent of dissection remains controversial. Blind lymph node sampling or level I dissection may miss some nodal metastases, but ALND may result in lymphedema. In melanoma, intraoperative lymph node mapping with sentinel lymphadenectomy is an effective and minimally invasive alternative to ALND for identifying nodes containing metastases. METHODS: One hundred seventy-four mapping procedures were performed using a vital dye injected at the primary breast cancer site. Axillary lymphatics were identified and followed to the first ("sentinel") node, which was selectively excised before ALND. RESULTS: Sentinel nodes were identified in 114 of 174 (65.5%) procedures and accurately predicted axillary nodal status in 109 of 114 (95.6%) cases. There was a definite learning curve, and all false-negative sentinel nodes occurred in the first part of the study; sentinel nodes identified in the last 87 procedures were 100% predictive. In 16 of 42 (38.0%) clinically negative/pathologically positive axillae, the sentinel node was the only tumor-involved lymph node identified. The anatomic location of the sentinel node was examined in the 54 most recent procedures; ten cases had only level II nodal metastases that could have been missed by sampling or low (level I) axillary dissection. CONCLUSIONS: This experience indicates that intraoperative lymphatic mapping can accurately identify the sentinel node--i.e., the axillary lymph node most likely to contain breast cancer metastases--in some patients. The technique could enhance staging accuracy and, with further refinements and experience, might alter the role of ALND. Images Figure 1. Figure 2. Figure 3. PMID:8092905

  6. Lymphatic filariasis in Brazil: epidemiological situation and outlook for elimination

    PubMed Central

    2012-01-01

    Since the World Health Assembly’s (Resolution WHA 50.29, 1997) call for the elimination of lymphatic filariasis by the year 2020, most of the endemic countries identified have established programmes to meet this objective. In 1997, a National Lymphatic Filariasis Elimination Plan was drawn up by the Ministry of Health of Brazil, creating local programs for the elimination of Bancroftian filariasis in areas with active transmission. Based on a comprehensive bibliographic search for available studies and reports of filariasis epidemiology in Brazil, current status of this parasitic infection and the outlook for its elimination in the country were analysed. From 1951 to 1958 a nationwide epidemiological study conducted in Brazil confirmed autochthonous transmission of Bancroftian filariasis in 11 cities of the country. Control measures led to a decline in parasite rates, and in the 1980s only the cities of Belém in the Amazonian region (Northern region) and Recife (Northeastern region) were considered to be endemic. In the 1990s, foci of active transmission of LF were also described in the cities of Maceió, Olinda, Jaboatão dos Guararapes, and Paulista, all in the Northeastern coast of Brazil. Data provide evidence for the absence of microfilaremic subjects and infected mosquitoes in Belém, Salvador and Maceió in the past few years, attesting to the effectiveness of the measures adopted in these cities. Currently, lymphatic filariasis is a public health problem in Brazil only in four cities of the metropolitan Recife region (Northeastern coast). Efforts are being concentrated in these areas, with a view to eliminating the disease in the country. PMID:23181663

  7. Isolation, Characterization, and Functional Analysis of Ferret Lymphatic Endothelial Cells

    PubMed Central

    Berendam, Stella J.; Fallert-Junecko, Beth A.; Murphy-Corb, Michael A.; Fuller, Deborah H.; Reinhart, Todd A.

    2014-01-01

    The lymphatic endothelium (LE) serves as a conduit for transport of immune cells and soluble antigens from peripheral tissues to draining lymph nodes (LNs), contributing to development of host immune responses and possibly dissemination of microbes. Lymphatic endothelial cells (LECs) are major constituents of the lymphatic endothelium. These specialized cells could play important roles in initiation of host innate immune responses through sensing of pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors (PRRs), including toll-like receptors (TLRs). LECs secrete pro-inflammatory cytokines and chemokines to create local inflammatory conditions for recruitment of naïve antigen presenting cells (APCs) such as dendritic cells (DCs) to sites of infection and/or vaccine administration. In this study, we examined the innate immune potential of primary LEC populations derived from multiple tissues of an animal model for human infectious diseases -- the ferret. We generated a total of six primary LEC populations from lung, tracheal, and mesenteric LN tissues from three different ferrets. Standard RT-PCR characterization of these primary LECs showed that they varied in their expression of LEC markers. The ferret LECs were examined for their ability to respond to poly I:C (TLR3 and RIG-1 ligand) and other known TLR ligands as measured by production of proinflammatory cytokine (IFNα, IL6, IL10, Mx1, and TNFα) and chemokine (CCL5, CCL20, and CXCL10) mRNAs using real time RT-PCR. Poly I:C exposure induced robust proinflammatory responses by all of the primary ferret LECs. Chemotaxis was performed to determine the functional activity of CCL20 produced by the primary lung LECs and showed that the LEC-derived CCL20 was abundant and functional. Taken together, our results continue to reveal the innate immune potential of primary LECs during pathogen-host interactions and expand our understanding of the roles of LECs might play in health and disease in

  8. A microarray analysis of two distinct lymphatic endothelial cell populations.

    PubMed

    Schweighofer, Bernhard; Rohringer, Sabrina; Pröll, Johannes; Holnthoner, Wolfgang

    2015-06-01

    We have recently identified lymphatic endothelial cells (LECs) to form two morphologically different populations, exhibiting significantly different surface protein expression levels of podoplanin, a major surface marker for this cell type. In vitro shockwave treatment (IVSWT) of LECs resulted in enrichment of the podoplanin(high) cell population and was accompanied by markedly increased cell proliferation, as well as 2D and 3D migration. Gene expression profiles of these distinct populations were established using Affymetrix microarray analyses. Here we provide additional details about our dataset (NCBI GEO accession number GSE62510) and describe how we analyzed the data to identify differently expressed genes in these two LEC populations.

  9. Mathematical models and lymphatic filariasis control: monitoring and evaluating interventions.

    PubMed

    Michael, Edwin; Malecela-Lazaro, Mwele N; Maegga, Bertha T A; Fischer, Peter; Kazura, James W

    2006-11-01

    Monitoring and evaluation are crucially important to the scientific management of any mass parasite control programme. Monitoring enables the effectiveness of implemented actions to be assessed and necessary adaptations to be identified; it also determines when management objectives are achieved. Parasite transmission models can provide a scientific template for informing the optimal design of such monitoring programmes. Here, we illustrate the usefulness of using a model-based approach for monitoring and evaluating anti-parasite interventions and discuss issues that need addressing. We focus on the use of such an approach for the control and/or elimination of the vector-borne parasitic disease, lymphatic filariasis. PMID:16971182

  10. ACE Inhibitor in the treatment of cutaneous and lymphatic sarcoidosis.

    PubMed

    Kaura, Vinod; Kaura, Samantha H; Kaura, Claire S

    2007-01-01

    Angiotensin-converting enzyme is used as a marker for sarcoid activity. We describe a case of remission of cutaneous and lymphatic sarcoidosis in a patient treated with an ACE inhibitor for congestive heart failure and hypertension; the remission has continued over 4 years of follow-up. Because this is a report of only one case, there is a possibility of sampling error. Whether the patient's remission in this case was a serendipitous spontaneous remission that happened to occur during ACE inhibitor therapy or whether ACE inhibitor therapy can play a role in the treatment of sarcoidosis needs to be determined in a large clinical trial.

  11. [Retroperitoneal "lymphatic cysts" after radical operations in uterine cancer].

    PubMed

    Dekster, L I; Vasil'ev, B V

    1979-01-01

    The authors report the results of studying the complications of iliac lymphadenectomy--lymphocysts developed after radical operations in 16 of 415 operated patients with cancer of the uterus. The method of indirect radioisotope lymphography may be considered to be the most simple method of detecting lymphatic cysts. Small size lymphocysts require no special surgical intervention. Extensive incapsulated lymph accumulation renders mandatory the incision and drainage of the lymphocyst in the iliac region at the site of the involvement. The most rational prophylactic measures against lymphocysts seem to be the provision for active lymph outflow by vacuum drainage.

  12. Facilitation of the swallowing reflex with bilateral afferent input from the superior laryngeal nerve.

    PubMed

    Takahashi, Kojiro; Shingai, Tomio; Saito, Isao; Yamamura, Kensuke; Yamada, Yoshiaki; Kitagawa, Junichi

    2014-03-01

    To determine the cooperative effect of laryngeal afferent signals on the swallowing reflex, we examined whether afferent signals originating from the left and right superior laryngeal nerve (SLN) modulates elicitation of the swallowing reflex in urethane-anesthetized rats. Mylohyoid electromyographic activity was recorded to quantify the swallowing reflex. The onset latency of the swallowing reflex and the time intervals between successive swallows were used to quantify and compare the effects of unilateral and bilateral electrical stimulations of the SLN. The mean latency of the first swallow and the mean time interval between swallows evoked with low frequency stimulation were both significantly different between unilateral and bilateral stimulations of the SLN. These findings suggest that facilitatory effect of afferent signals originating from the SLN bilaterally increase the motoneuronal activity in the medullary swallowing center and enhance the swallowing reflex.

  13. Distribution of primary afferent fibres in the cochlear nuclei. A silver and horseradish peroxidase (HRP) study.

    PubMed Central

    Merchan, M A; Collia, F P; Merchan, J A; Saldana, E

    1985-01-01

    Horseradish peroxidase, when injected intracochlearly, is transported transganglionically to the brain stem cochlear nuclei, thus providing an excellent method for tracing the central projection of the spiral ganglion neurons. Silver impregnation using the Cajal-de Castro method, which stains axons even when inside the bone, was used as a reference technique. The combination of both procedures led to the following conclusions. Primary cochlear afferents are found only in the ventral zone of the dorsal cochlear nucleus. In this area they cover the deep and fusiform cell layers. The molecular layer shows no HRP label. The higher concentration of primary cochlear afferents in the ventral cochlear nucleus appears in its central zone; wide areas in this nucleus are not labelled at all. A thin bundle of primary cochlear afferents runs parallel to, and beneath, the granular region. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:4077711

  14. Primary afferent fibers establish dye-coupled connections in the frog central nervous system.

    PubMed

    Bácskai, Timea; Matesz, Clara

    Neurobiotin and Lucifer yellow, indicators of gap junctional coupling, were applied to primary afferent fibers of the frog. Following application of tracers to cervical or lumbar dorsal root fibers, a large number of labeled granule cells were detected in the corpus cerebelli, the brainstem, and the spinal cord. The vestibular nerve was found to be in dye-coupled connection with the granule cells of the auricular lobe of the cerebellum. After application of the tracers to the trigeminal nerve, elicited dye-coupled neurons located mainly in the termination area of the descending limb of the mesencephalic trigeminal nucleus. In control experiments with biotinylated dextrane amine, only primary afferent fibers were labeled. Our results suggest that gap junctional coupling exists between primary afferent fibers and their postsynaptic targets in the frog.

  15. Management of afferent loop obstruction from recurrent metastatic pancreatic cancer using a venting gastrojejunostomy

    PubMed Central

    Bakes, Debbie; Cain, Christian; King, Michael; Dong, Xiang Da (Eric)

    2013-01-01

    Pancreatic cancer is an aggressive malignancy potentially curable with surgical intervention. Following pancreaticoduodenectomy for suspected pancreatic head malignancy, patients have a high risk for both immediate and delayed problems due to surgical complications and recurrent disease. We report here a patient with pancreatic cancer treated with pancreaticoduodenectomy who developed recurrent disease resulting in obstruction of the afferent limb. The patient developed biliary obstruction and cholangitis at presentation. Her biliary tree failed to dilate which precluded safe percutaneous biliary decompression. During surgical exploration, she was found to have a dilated afferent limb at the level of the transverse mesocolon. The patient underwent decompression of the afferent limb as well as the biliary tree using a venting gastrojejunostomy to the blind loop. This represents a novel surgical approach for management of this complicated and difficult problem. PMID:24363832

  16. Investigational Lymphatic Imaging at the Bedside in a Pediatric Postoperative Chylothorax Patient

    PubMed Central

    Tan, I-Chih; Rasmussen, John C.; Sevick-Muraca, Eva M.; Balaguru, Duraisamy; Bricker, John T.; Guilliod, Renie; Douglas, William I.

    2014-01-01

    Background Chylothorax is a rare but serious complication in children who undergo heart surgery. Its pathogenesis is poorly understood, and invasive surgical treatments are considered only after conservative management fails. Current diagnostic imaging techniques, which could aid decision making for earlier surgical intervention, are difficult to apply. Herein, we deployed near-infrared fluorescence (NIRF) lymphatic imaging to allow the visualization of abnormal lymphatic drainage in an infant with postoperative chylothorax to guide the choice of surgical management. Methods A 5-week-old male infant, who developed chylothoraces after undergoing Norwood surgery for hypoplastic left heart syndrome, was intradermally administered trace doses of indocyanine green in both feet and the left hand. NIRF imaging was then performed at the bedside to visualize lymphatic drainage patterns. Results Imaging results indicated impeded lymphatic drainage from the feet toward the trunk with no fluorescence in the chest indicating no leakage of peripheral lymph at the thoracic duct. Instead, lymph drainage occurred from the axilla directly into the pleural cavity. As a result of imaging, left pleurodesis was performed to stop the pleural effusion with the result of temporary decrease of left chest tube drainage. Conclusion Although additional studies are required to understand normal and abnormal lymphatic drainage patterns in infants, we showed the potential of using NIRF lymphatic imaging at the bedside to visualize the lymphatic drainage pathway to guide therapy. Timely management of chylothorax may be improved by using NIRF imaging to understand lymphatic drainage pathways. PMID:24972649

  17. Development and validation of a custom made indocyanine green fluorescence lymphatic vessel imager.

    PubMed

    Pallotta, Olivia J; van Zanten, Malou; McEwen, Mark; Burrow, Lynne; Beesley, Jack; Piller, Neil

    2015-06-01

    Lymphoedema is a chronic progressive condition often producing significant morbidity. An in-depth understanding of an individual's lymphatic architecture is valuable both in the understanding of underlying pathology and for targeting and tailoring treatment. Severe lower limb injuries resulting in extensive loss of soft tissue require transposition of a flap consisting of muscle and/or soft tissue to close the defect. These patients are at risk of lymphoedema and little is known about lymphatic regeneration within the flap. Indocyanine green (ICG), a water-soluble dye, has proven useful for the imaging of lymphatic vessels. When injected into superficial tissues it binds to plasma proteins in lymph. By exposing the dye to specific wavelengths of light, ICG fluoresces with near-infrared light. Skin is relatively transparent to ICG fluorescence, enabling the visualization and characterization of superficial lymphatic vessels. An ICG fluorescence lymphatic vessel imager was manufactured to excite ICG and visualize real-time fluorescence as it travels through the lymphatic vessels. Animal studies showed successful ICG excitation and detection using this imager. Clinically, the imager has assisted researchers to visualize otherwise hidden superficial lymphatic pathways in patients postflap surgery. Preliminary results suggest superficial lymphatic vessels do not redevelop in muscle flaps.

  18. Development and validation of a custom made indocyanine green fluorescence lymphatic vessel imager

    NASA Astrophysics Data System (ADS)

    Pallotta, Olivia J.; van Zanten, Malou; McEwen, Mark; Burrow, Lynne; Beesley, Jack; Piller, Neil

    2015-06-01

    Lymphoedema is a chronic progressive condition often producing significant morbidity. An in-depth understanding of an individual's lymphatic architecture is valuable both in the understanding of underlying pathology and for targeting and tailoring treatment. Severe lower limb injuries resulting in extensive loss of soft tissue require transposition of a flap consisting of muscle and/or soft tissue to close the defect. These patients are at risk of lymphoedema and little is known about lymphatic regeneration within the flap. Indocyanine green (ICG), a water-soluble dye, has proven useful for the imaging of lymphatic vessels. When injected into superficial tissues it binds to plasma proteins in lymph. By exposing the dye to specific wavelengths of light, ICG fluoresces with near-infrared light. Skin is relatively transparent to ICG fluorescence, enabling the visualization and characterization of superficial lymphatic vessels. An ICG fluorescence lymphatic vessel imager was manufactured to excite ICG and visualize real-time fluorescence as it travels through the lymphatic vessels. Animal studies showed successful ICG excitation and detection using this imager. Clinically, the imager has assisted researchers to visualize otherwise hidden superficial lymphatic pathways in patients postflap surgery. Preliminary results suggest superficial lymphatic vessels do not redevelop in muscle flaps.

  19. Immunohistochemical identification of lymphatic vessels in the periodontium of equine cheek teeth.

    PubMed

    Staszyk, Carsten; Duesterdieck, Katja F; Gasse, Hagen; Bienert, Astrid

    2005-12-01

    Immunohistochemical detection of lymphatic capillaries was performed in the periodontium of maxillary and mandibular cheek teeth from 6 horses (aged 3-23 years). Tissue sections of the periodontium were taken at 4 different horizontal levels along the long axis of the tooth. The specimens were processed for immunoreaction with anti-Prox1, in order to distinguish lymphatic endothelium from blood vascular endothelium. Lymphatic vessels were detected in all periodontal tissues except for the dental cementum. Lymphatic capillaries were most densely distributed in the gingiva compared to other tissues of the periodontium. Lymphatic capillaries were found most consistently in samples taken from the gingival and subgingival regions in all horses examined. Within these levels, the gingiva as well as the spongiosa of the maxillary and mandibular bone had the greatest incidence of lymphatic vessels. Considering the distinct distribution of the lymphatic capillaries in the periodontium of the maxillary and mandibular cheek teeth, two complementary lymphatic drainage pathways are proposed: (1) superficial lymph drainage via the gingiva, emptying into the mandibular lymph nodes; (2) deep lymph drainage via the mandibular and maxillary spongiosa, emptying into the mandibular and retropharyngeal lymph nodes, respectively.

  20. Adipose veno-lymphatic transfer for management of post-radiation lymphedema

    SciTech Connect

    Pho, R.W.; Bayon, P.; Tan, L.

    1989-01-01

    In a patient who had post-radiation lymphedema after excision of liposarcoma, a method is described that is called adipose veno-lymphatic transfer. The technique involves transferring adipose tissue containing lymphatic vessels that surround the long saphenous vein, from the normal, healthy leg to the irradiated leg, with the creation of an arteriovenous fistula.

  1. Ischemia-Reperfusion Injury Enhances Lymphatic Endothelial VEGFR3 and Rejection in Cardiac Allografts.

    PubMed

    Dashkevich, A; Raissadati, A; Syrjälä, S O; Zarkada, G; Keränen, M A I; Tuuminen, R; Krebs, R; Anisimov, A; Jeltsch, M; Leppänen, V-M; Alitalo, K; Nykänen, A I; Lemström, K B

    2016-04-01

    Organ damage and innate immunity during heart transplantation may evoke adaptive immunity with serious consequences. Because lymphatic vessels bridge innate and adaptive immunity, they are critical in immune surveillance; however, their role in ischemia-reperfusion injury (IRI) in allotransplantation remains unknown. We investigated whether the lymphangiogenic VEGF-C/VEGFR3 pathway during cardiac allograft IRI regulates organ damage and subsequent interplay between innate and adaptive immunity. We found that cardiac allograft IRI, within hours, increased graft VEGF-C expression and lymphatic vessel activation in the form of increased lymphatic VEGFR3 and adhesion protein expression. Pharmacological VEGF-C/VEGFR3 stimulation resulted in early lymphatic activation and later increase in allograft inflammation. In contrast, pharmacological VEGF-C/VEGFR3 inhibition during cardiac allograft IRI decreased early lymphatic vessel activation with subsequent dampening of acute and chronic rejection. Genetic deletion of VEGFR3 specifically in the lymphatics of the transplanted heart recapitulated the survival effect achieved by pharmacological VEGF-C/VEGFR3 inhibition. Our results suggest that tissue damage rapidly changes lymphatic vessel phenotype, which, in turn, may shape the interplay of innate and adaptive immunity. Importantly, VEGF-C/VEGFR3 inhibition during solid organ transplant IRI could be used as lymphatic-targeted immunomodulatory therapy to prevent acute and chronic rejection. PMID:26689983

  2. An abnormal lymphatic phenotype is associated with subcutaneous adipose tissue deposits in Dercum’s disease

    PubMed Central

    Rasmussen, John C.; Herbst, Karen L.; Aldrich, Melissa B.; Darne, Chinmay D.; Tan, I-Chih; Zhu, Banghe; Guilliod, Renie; Fife, Caroline A.; Maus, Erik A.; Sevick-Muraca, Eva M.

    2014-01-01

    Objective Investigational, near-infrared fluorescence (NIRF) lymphatic imaging was used to assess lymphatic architecture and contractile function in participants diagnosed with Dercum’s disease, a rare, poorly understood disorder characterized by painful lipomas in subcutaneous adipose tissues. Design and Methods After informed consent and as part of an FDA-approved feasibility study to evaluate lymphatics in diseases in which their contribution has been implicated, three women diagnosed with Dercum’s disease and four control subjects were imaged. Each participant received multiple intradermal and subcutaneous injections of indocyanine green (ICG, total dose ≤400µg) in arms, legs, and/or trunk. Immediately after injection, ICG was taken up by the lymphatics and NIRF imaging was conducted. Results The lymphatics in the participants with Dercum’s disease were intact and dilated, yet sluggishly propelled lymph when compared to control lymphatics. Palpation of regions containing fluorescent lymphatic pathways revealed tender, fibrotic, tubular structures within the subcutaneous adipose tissue that were associated with painful nodules, and, in some cases, masses of fluorescent tissue indicating that some lipomas may represent tertiary lymphoid tissues. Conclusions These data support the hypothesis that Dercum’s disease may be a lymphovascular disorder and suggest a possible association between abnormal adipose tissue deposition and abnormal lymphatic structure and function. PMID:25044620

  3. Vascular Endothelial Growth Factor D Is Dispensable for Development of the Lymphatic System

    PubMed Central

    Baldwin, Megan E.; Halford, Michael M.; Roufail, Sally; Williams, Richard A.; Hibbs, Margaret L.; Grail, Dianne; Kubo, Hajime; Stacker, Steven A.; Achen, Marc G.

    2005-01-01

    Vascular endothelial growth factor receptor 3 (Vegfr-3) is a tyrosine kinase that is expressed on the lymphatic endothelium and that signals for the growth of the lymphatic vessels (lymphangiogenesis). Vegf-d, a secreted glycoprotein, is one of two known activating ligands for Vegfr-3, the other being Vegf-c. Vegf-d stimulates lymphangiogenesis in tissues and tumors; however, its role in embryonic development was previously unknown. Here we report the generation and analysis of mutant mice deficient for Vegf-d. Vegf-d-deficient mice were healthy and fertile, had normal body mass, and displayed no pathologic changes consistent with a defect in lymphatic function. The lungs, sites of strong Vegf-d gene expression during embryogenesis in wild-type mice, were normal in Vegf-d-deficient mice with respect to tissue mass and morphology, except that the abundance of the lymphatics adjacent to bronchioles was slightly reduced. Dye uptake experiments indicated that large lymphatics under the skin were present in normal locations and were functional. Smaller dermal lymphatics were similar in number, location, and function to those in wild-type controls. The lack of a profound lymphatic phenotype in Vegf-d-deficient mice suggests that Vegf-d does not play a major role in lymphatic development or that Vegf-c or another, as-yet-unknown activating Vegfr-3 ligand can compensate for Vegf-d during development. PMID:15743836

  4. Short latency activation of pyramidal tract cells by Group I afferent volleys in the cat

    PubMed Central

    Swett, John E.; Bourassa, Charles M.

    1967-01-01

    1. The contralateral bulbar pyramids were explored with low impedance micro-electrodes in cats anaesthetized with chloralose to reveal the effect of Group I afferent volleys (deep radial nerve of the forelimb) on pyramidal tract (Pt) cells. 2. Low rate (0·5/sec) stimulation of Group I afferents produced small responses (5-30 μV) in the bulbar pyramid which could be detected only with response averaging methods. The responses appeared with an initial latency of 7·0-11·2 msec and reached peak amplitude in 15·7 msec (mean latency). The pyramidal tract origin of the potential was demonstrated by its depression at stimulus rates above 1-2 sec and its disappearance at rates above 4/sec. 3. Recordings of neurones in the Group I cortical projection zone of the posterior sigmoid gyrus revealed that several types of cells, including Pt cells, were activated by Group I afferent volleys. 4. Pt cells responding to Group I afferent volleys frequently received convergent actions from low threshold cutaneous nerve volleys. 5. Averaged response recordings from electrodes positioned in the medial portions of the lateral funiculus of the spinal cord at the level of C2, revealed a response to Group I afferent volleys as early as 7·4 msec which possessed the same characteristics as the relayed response to Group I in the bulbar pyramids. Some Pt cells, activated by Group I volleys orthodromically, could also be antidromically activated by stimulation of the recording site in C2. 6. It was concluded that group I afferent volleys can influence, after short latencies, Pt and non-Pt cells and that some of these Pt cells gave rise to axons incorporated in the corticospinal tract. PMID:16992239

  5. Characterization of silent afferents in the pelvic and splanchnic innervations of the mouse colorectum.

    PubMed

    Feng, Bin; Gebhart, G F

    2011-01-01

    Hypersensitivity in inflammatory/irritable bowel syndrome is contributed to in part by changes in the receptive properties of colorectal afferent endings, likely including mechanically insensitive afferents (MIAs; silent afferents) that have the ability to acquire mechanosensitivity. The proportion and attributes of colorectal MIAs, however, have not previously been characterized. The distal ∼3 cm of colorectum with either pelvic (PN) or lumbar splanchnic (LSN) nerve attached was removed, opened longitudinally, pinned flat in a recording chamber, and perfused with oxygenated Krebs solution. Colorectal receptive endings were located by electrical stimulation and characterized as mechanosensitive or not by blunt probing, mucosal stroking, and circumferential stretch. MIA endings were tested for response to and acquisition of mechanosensitivity by localized exposure to an inflammatory soup (IS). Colorectal afferents were also tested with twin-pulse and repetitive electrical stimulation paradigms. PN MIAs represented 23% of 211 afferents studied, 71% (30/42) of which acquired mechanosensitivity after application of IS to their receptive ending. LSN MIAs represented 33% of 156 afferents studied, only 23% (11/48) of which acquired mechanosensitivity after IS exposure. Mechanosensitive PN endings uniformly exhibited significant twin-pulse slowing whereas LSN endings showed no significant twin-pulse difference. PN MIAs displayed significantly greater activity-dependent slowing than LSN MIAs. In conclusion, significant proportions of MIAs are present in the colorectal innervation; significantly more in the PN than LSN acquire mechanosensitivity in an inflammatory environment. This knowledge contributes to our understanding of the possible roles of MIAs in colon-related disorders like inflammatory/irritable bowel syndrome. PMID:21071510

  6. Impaired excitability of renal afferent innervation after exposure to the inflammatory chemokine CXCL1.

    PubMed

    Ditting, Tilmann; Freisinger, Wolfgang; Rodionova, Kristina; Schatz, Johannes; Lale, Nena; Heinlein, Sonja; Linz, Peter; Ott, Christian; Schmieder, Roland E; Scrogin, Karie E; Veelken, Roland

    2016-03-01

    Recently, we showed that renal afferent neurons exhibit a unique firing pattern, i.e., predominantly sustained firing, upon stimulation. Pathological conditions such as renal inflammation likely alter excitability of renal afferent neurons. Here, we tested whether the proinflammatory chemokine CXCL1 alters the firing pattern of renal afferent neurons. Rat dorsal root ganglion neurons (Th11-L2), retrogradely labeled with dicarbocyanine dye, were incubated with CXCL1 (20 h) or vehicle before patch-clamp recording. The firing pattern of neurons was characterized as tonic, i.e., sustained action potential (AP) firing, or phasic, i.e., <5 APs following current injection. Of the labeled renal afferents treated with vehicle, 58.9% exhibited a tonic firing pattern vs. 7.8%, in unlabeled, nonrenal neurons (P < 0.05). However, after exposure to CXCL1, significantly more phasic neurons were found among labeled renal neurons; hence the occurrence of tonic neurons with sustained firing upon electrical stimulation decreased (35.6 vs. 58.9%, P < 0.05). The firing frequency among tonic neurons was not statistically different between control and CXCL1-treated neurons. However, the lower firing frequency of phasic neurons was even further decreased with CXCL1 exposure [control: 1 AP/600 ms (1-2) vs. CXCL1: 1 AP/600 ms (1-1); P < 0.05; median (25th-75th percentile)]. Hence, CXCL1 shifted the firing pattern of renal afferents from a predominantly tonic to a more phasic firing pattern, suggesting that CXCL1 reduced the sensitivity of renal afferent units upon stimulation.

  7. Botulinum toxin in Migraine: Role of transport in trigemino-somatic and trigemino-vascular afferents

    PubMed Central

    Roshni, Ramachandran; Carmen, Lam; Yaksh Tony, L

    2015-01-01

    Migraine secondary to meningeal input is referred to extracranial regions innervated by somatic afferents that project to homologous regions in the trigeminal nucleus caudalis (TNC). Reported efficacy of extracranial botulinum toxin (BoNT) in treating migraine is surprising since a local extracranial effect of BoNT cannot account for its effect upon meningeal input. We hypothesize that intradermal BoNT acts through central transport in somatic afferents. Anesthetized C57Bl/6 mice (male) received unilateral supraorbital (SO) injections of BoNT-B (1.5 U/40 μl) or saline. 3 days later, mice received ipsilateral (ipsi) -SO capsaicin (2.5 μg/30 μl) or meningeal capsaicin (4 μl of 1mg/ml). Pre-treatment with ipsi-SO BONT-B i) decreased nocicsponsive ipsilateral wiping behavior following ipsi-SO capsaicin; ii) produced cleavage of VAMP in the V1 region of ipsi-TG and in TG neurons showing WGA after SO injection; iii) reduced expression of c-fos in ipsi-TNC following ipsi-SO capsaicin; iv) reduced c-fos activation and NK-1 internalization in ipsi-TNC secondary to ipsi-meningeal capsaicin; vi) SO WGA did not label dural afferents. We conclude that BoNT-B is taken up by peripheral afferents and transported to central terminals where it inhibits transmitter release resulting in decreased activation of second order neurons. Further, this study supports the hypothesis that SO BoNT exerts a trans-synaptic action on either the second order neuron (which receives convergent input from the meningeal afferent) or the terminal/TG of the converging meningeal afferent. PMID:25958249

  8. Characterization of silent afferents in the pelvic and splanchnic innervations of the mouse colorectum

    PubMed Central

    Gebhart, G. F.

    2011-01-01

    Hypersensitivity in inflammatory/irritable bowel syndrome is contributed to in part by changes in the receptive properties of colorectal afferent endings, likely including mechanically insensitive afferents (MIAs; silent afferents) that have the ability to acquire mechanosensitivity. The proportion and attributes of colorectal MIAs, however, have not previously been characterized. The distal ∼3 cm of colorectum with either pelvic (PN) or lumbar splanchnic (LSN) nerve attached was removed, opened longitudinally, pinned flat in a recording chamber, and perfused with oxygenated Krebs solution. Colorectal receptive endings were located by electrical stimulation and characterized as mechanosensitive or not by blunt probing, mucosal stroking, and circumferential stretch. MIA endings were tested for response to and acquisition of mechanosensitivity by localized exposure to an inflammatory soup (IS). Colorectal afferents were also tested with twin-pulse and repetitive electrical stimulation paradigms. PN MIAs represented 23% of 211 afferents studied, 71% (30/42) of which acquired mechanosensitivity after application of IS to their receptive ending. LSN MIAs represented 33% of 156 afferents studied, only 23% (11/48) of which acquired mechanosensitivity after IS exposure. Mechanosensitive PN endings uniformly exhibited significant twin-pulse slowing whereas LSN endings showed no significant twin-pulse difference. PN MIAs displayed significantly greater activity-dependent slowing than LSN MIAs. In conclusion, significant proportions of MIAs are present in the colorectal innervation; significantly more in the PN than LSN acquire mechanosensitivity in an inflammatory environment. This knowledge contributes to our understanding of the possible roles of MIAs in colon-related disorders like inflammatory/irritable bowel syndrome. PMID:21071510

  9. Regulation of lymphatic-blood vessel separation by endothelial Rac1

    PubMed Central

    D'Amico, Gabriela; Jones, Dylan T.; Nye, Emma; Sapienza, Karen; Ramjuan, Antoine R.; Reynolds, Louise E.; Robinson, Stephen D.; Kostourou, Vassiliki; Martinez, Dolores; Aubyn, Deborah; Grose, Richard; Thomas, Gareth J.; Spencer-Dene, Bradley; Zicha, Daniel; Davies, Derek; Tybulewicz, Victor; Hodivala-Dilke, Kairbaan M.

    2009-01-01

    Sprouting angiogenesis and lymphatic-blood vessel segregation both involve the migration of endothelial cells, but the precise migratory molecules that govern the decision of blood vascular endothelial cells to segregate into lymphatic vasculature are unknown. Here, we deleted endothelial Rac1 in mice (Tie1-Cre+;Rac1fl/fl) and revealed, unexpectedly, that whereas b