[Consensus paper--adequate medication for neurologic and geriatric patients with dysphagia]. / Konsensuspapier--Bedarfsgerechte Medikation bei neurologischen und geriatrischen Dysphagie-Patienten.

BACKGROUND: The incidence for dysphagia amounts to 44-50% in nursing homes. Dysphagia is one of the main reasons for pneumonia in elderly. METHOD: Consensus paper. RESULTS AND CONCLUSIONS: For the advisory board consisting of 2 physicians, 2 pharmacists, a speech therapist, and a respresentative of nursing service it is common understanding that for the ideal maintenance and support of patients with dysphagia an interdisciplinary approach is crucial. Despite high clinical relevance of dysphagia the basic knowledge of this field is often underdeveloped. Specific and validated screening procedures for dysphagia have to be developed and implemented into the relevant guidelines. Specifically in this field an active and discipline spanning risk management should find its way into stationary geriatric care and nursing homes. Just as important is the provision of necessary patient information on the progress of the disease, on therapeutic actions and possible diet forms in a dysphagia pass. Additionally, the mentioned disciplines require an online risk screening (for dysphagia) of the pharmacist concerning the overall medication as well as information of galenic properties like facts regarding the possibility of crushing, portioning or tube feeding of the prescribed medication. In this way health risks due to administration errors concerning the medication can be significantly reduced for this patient group. Adequate oral liquids for adapted application of drugs are missing so far.

Analysis of SM4 sulfatide as a P-selectin ligand using model membranes.

Carcinoma tumor cells express highly glycosylated mucins acting as ligands for selectin adhesion receptors and thus facilitating the metastatic process. Recently, a sulfated galactocerebroside SM4 was detected as solely P-selectin ligand on MC-38 colon carcinoma cells. Here we characterize the functionality of SM4 as selectin ligand using model membrane approaches. SM4 was found concentrated in lipid rafts of MC-38 cells indicating a local clustering that may increase the avidity of P-selectin recognition. To confirm this, SM4 was incorporated at various concentrations into POPC model membranes and lateral clustering was analyzed by fluorescence microscopy and found to be comparable to glycolipids carrying the sLe(x) epitope. SM4 containing liposomes were used as cell models, binding to immobilized P-selectin. Quartz crystal microbalance data confirmed SM4/P-selectin liposome binding that was inhibited dose-dependently by heparin. Comparable binding characteristics of SM4 and sLe(x) liposomes underscore the similarity of these epitopes. Thus, clustering of SM4 on tumor cells is a principle for binding P-selectin.

Binding between heparin and the integrin VLA-4.

Heparin possesses antimetastatic effects that were related to various molecular mechanisms beyond anticoagulant activities. The ability of heparin to interfere with the function of adhesion receptors in the metastatic course appears as a promising therapeutic approach. This refers to numerous findings that heparin attenuates metastasis in a selectin-dependent manner. We recently demonstrated that heparin interferes with the integrin VLA-4 on murine melanoma cells binding to VCAM-1. To confirm this activity and to obtain further insight into molecular recognition of heparin by VLA-4, we investigated the inhibition of VLA-4 mediated binding of human melanoma MV3 cells to immobilised VCAM-1 by different heparins. The size of heparin has an important impact on inhibition. Unfractionated heparin (UFH) and tinzaparin, a low-molecular-weight heparin (LMWH) representing a mean of about 18-20 monomers, displayed high inhibitory activity. Fractionating tinzaparin to 14-18 monomers reduced inhibition slightly, while the pentasaccharide fondaparinux was without effects. To confirm molecular recognition of tinzaparin by VLA-4, a surface acoustic wave-biosensor was applied. A VLA-4 containing membrane preparation of MV3 cells was immobilised at the sensors to allow for detection of kinetic binding constants of tinzaparin compared to VCAM-1. Tinzaparin binds to VLA-4 with affinity in the low micromolar range (4.61 x 10(-6) M), which clearly indicates specific molecular recognition. Furthermore, tinzaparin displays a nearly identical k(off) compared to VCAM-1 (5.13 x 10(-3) s(-1) versus 3.44 x 10(-3) s(-1)) which is evident for interference with the ligand binding. The data provide evidence for a direct confirmation of heparin binding to VLA-4 and thus, contribute to understand the antimetastatic activity of heparin.

Melanoma cell adhesion can be blocked by heparin in vitro: suggestion of VLA-4 as a novel target for antimetastatic approaches.

The clinical benefit of heparin in cancer patients to prolong survival can be attributed to non-anticoagulant mechanisms. Since adhesion molecules are crucially involved in tumour cell metastasis, their inhibition offers an attractive approach for interfering with the metastatic cascade. Heparin is known to attenuate metastasis in a selectin-dependent manner and possesses a variety of additional effects that are thought to influence tumour cell dissemination, proliferation, and angiogenesis. We investigated the adhesion behaviour of B16F10 melanoma cells in vitro regarding selectin- and VLA-4/VCAM-1-mediated binding to get an insight into underlying mechanisms of melanoma cell metastasis. We show that B16F10 cells display binding ability to P- and L-selectin as well as to isolated platelets. In contrast, B16F10 cells did not adhere to immobilized P-selectin under flow. This contributes to recent findings that elucidate a major role of platelet P-selectin for microemboli formation and thus, facilitating metastasis. In contrast, B16F10 cells adhered to endothelial cells under flow, which could partly be inhibited by a function-blocking anti-VCAM-1 mAb. To emphasize VCAM-1 function, we analyzed cell adhesion at immobilized VCAM-1 and observed an integrin dependency. Inhibition experiments reveal that heparin influences VLA-4-mediated binding pathways. By a combination of different techniques we prove that the site of heparin action is rather VLA-4 than VCAM-1. To our knowledge, this is the first time that heparin is shown to interfere with the VLA-4/VCAM-1 interaction leading to the suggestion of a novel heparin target. Our results may contribute to the understanding of how heparin exerts its anti-metastatic activity.

Affinity and kinetics of different heparins binding to P- and L-selectin.

Selectins are adhesion receptors that participate in inflammation and tumor cell metastasis. The anti-inflammatory and antimetastatic activities of heparins have been related partly to their ability to interact with P- and L-selectin. The recent findings that various heparins differ in antimetastatic activity were explained by differences in their P- and L-selectin binding ability. To obtain data to illustrate the binding characteristics, we detected for the first time the binding kinetics and affinity of the two low molecular weight heparins (LMWHs) enoxaparin and nadroparin, and of the unfractionated heparin Liquemin N to P- and L-selectin using a quartz crystal microbalance biosensor. Enoxaparin and nadroparin behave nearly identical in their binding affinity to both P-selectin ( KD 4.60 x 10 (- 6) M versus 7.61 x 10 (- 6) M) and L-selectin ( KD 2.01 x 10 (- 6) M versus 2.84 x 10 (- 6) M). Liquemin N displayed slightly higher affinities to both selectins ( KD 6.07 x 10 (- 7) M versus 1.07 x 10 (- 7) M). The differences are caused by a higher association rate compared with that of the LMWHs. These data support recent findings of antimetastatic activities, but illustrate that the intrinsic selectin binding does not entirely reflect the antimetastatic activities in vivo.

Kinetic analysis of heparin and glucan sulfates binding to P-selectin and its impact on the general understanding of selectin inhibition.

P-Selectin, expressed on activated endothelial cells and platelets, is a high kinetic adhesion receptor involved in leukocyte rolling of the inflammatory response, or in tumor cell binding in the course of metastasis. Thus, P-selectin inhibition is a promising therapeutic target. The anti-inflammatory and anti-metastatic activities of heparin have partly been related to the inhibition of P-selectin binding. Here we apply a quartz crystal microbalance (QCM) biosensor to determine the kinetic constants of heparin and other sulfated polysaccharides binding to immobilized P-selectin. Binding kinetics of the derivatives were correlated with their inhibitory capacity in a P-selectin cell rolling assay. Three commercial heparins differ in cell rolling inhibition and display slightly different affinities (KD 1.21 x 10(-6) M to 5.86 x 10(-7) M). Inhibitory capacity appears to be mainly driven by a slow off-rate from the receptor (2.27 x 10(-3) s-1 to 1.23 x 10(-3) s-1). To correlate the impact of binding kinetics on inhibitory capacity structurally, we analyzed six semisynthetic glucan sulfates. They display different degrees of sulfation (DS), which has a strong influence on inhibitory activity. Kinetic data illustrate that the inhibitory capacity correlates excellently with the off-rate of these polysaccharides (R = 0.99), while the association (on-rate) affects activity to a lesser extent. In general, the consideration of binding kinetics sheds new light on the mechanism of selectin inhibition. A much slower dissociation of the inhibitors from the receptor than the physiological ligands is key for inhibitory capacity. Structurally, highly charged compounds with a slow off-rate, such as heparin or glucan sulfates, appear as potent candidates for P-selectin inhibition.