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- Hess, Paul R, et al.
(författare)
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Platelets mediate lymphovenous hemostasis to maintain blood-lymphatic separation throughout life.
- 2014
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Ingår i: Journal of Clinical Investigation. - 0021-9738 .- 1558-8238. ; 124:1
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Tidskriftsartikel (refereegranskat)abstract
- Mammals transport blood through a high-pressure, closed vascular network and lymph through a low-pressure, open vascular network. These vascular networks connect at the lymphovenous (LV) junction, where lymph drains into blood and an LV valve (LVV) prevents backflow of blood into lymphatic vessels. Here we describe an essential role for platelets in preventing blood from entering the lymphatic system at the LV junction. Loss of CLEC2, a receptor that activates platelets in response to lymphatic endothelial cells, resulted in backfilling of the lymphatic network with blood from the thoracic duct (TD) in both neonatal and mature mice. Fibrin-containing platelet thrombi were observed at the LVV and in the terminal TD in wild-type mice, but not Clec2-deficient mice. Analysis of mice lacking LVVs or lymphatic valves revealed that platelet-mediated thrombus formation limits LV backflow under conditions of impaired valve function. Examination of mice lacking integrin-mediated platelet aggregation indicated that platelet aggregation stabilizes thrombi that form in the lymphatic vascular environment to prevent retrograde blood flow. Collectively, these studies unveil a newly recognized form of hemostasis that functions with the LVV to safeguard the lymphatic vascular network throughout life.
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| 2. |
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| 3. |
- Schiebe, Christian, et al.
(författare)
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Semiochemical diversity diverts bark beetle attacks from Norway spruce edges
- 2011
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Ingår i: Journal of applied entomology. - : WILEY. - 0931-2048 .- 1439-0418. ; 135:10, s. 726-737
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Tidskriftsartikel (refereegranskat)abstract
- The semiochemical diversity hypothesis (SDH) states that interference with host-selection from non-host volatiles (NHV) is an important mechanism for associational resistance. Inhibition of bark beetle attraction to point sources by non-host volatiles (NHV) is well established and might be a signal serving in host-selection also at the habitat scale. In forests dominated by Norway spruce in middle and northern Europe (N Slovakia 2006 & 2007, SE Sweden 2007), we applied a blend of NHV and verbenone, released from dispensers fixed at 2 and 6 m height at forest edges with high Ips typographus populations. In Slovakia, three different doses (0.2–0.7 dispensers/m forest edge) were tested in 20-tree zones of spruce stand edges. The Swedish experiments used only the middle dose. In Slovakia, there was high tree mortality but dispensers with the anti-attractants reduced killed trees in a dose-dependent manner. The reduction in tree killing ranged from 35 to 76% compared to untreated zones. Regression analysis of relative tree kill on log dispenser density was highly significant (R2ADJ= 0.34, corresponding effect size d≈ 0.98). In Sweden, with lower beetle populations, most attacks (99%) were found outside the experimental areas, with high attack rates (15 trees/ha) in a range of 15–30 m from treated groups, indicating an active inhibitory radius exceeding the previous estimates. The SDH as a functional aspect of biodiversity was tested by converting spruce monocultures into an artificial semiochemically mixed forests. The use of NHV provides the only non-insecticidal method of direct protection of conifer forests. The demonstrated principle of protection is still too expensive for area-wide use, but viable for high-value areas (nature reserves). Further development of push–pull strategies or area-wide applications may prove more cost efficient. In the long-term, the only sustainable approach is a forest landscape of mixed habitats.
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