Vasoconstrictor stimulus determines the functional contribution of myoendothelial feedback to mesenteric arterial tone.

KEY POINTS: In isolated resistance arteries, endothelial modulation of vasoconstrictor responses to α1 -adrenoceptor agonists occurs via a process termed myoendothelial feedback: localized inositol trisphosphate (InsP3 )-dependent Ca2+ transients activate intermediate conductance Ca2+ -activated K+ (IKCa ) channels, hyperpolarizing the endothelial membrane potential to limit further reductions in vessel diameter. We demonstrate that IKCa channel-mediated myoendothelial feedback limits responses of isolated mesenteric arteries to noradrenaline and nerve stimulation, but not to the thromboxane A2 mimetic U46619 or to increases in intravascular pressure. In contrast, in the intact mesenteric bed, although responses to exogenous noradrenaline were limited by IKCa channel-mediated myoendothelial feedback, release of NO and activation of endothelial small conductance Ca2+ -activated K+ (SKCa ) channels in response to increases in shear stress appeared to be the primary mediators of endothelial modulation of vasoconstriction. We propose that (1) the functional contribution of myoendothelial feedback to arterial tone is determined by the nature of the vasoconstrictor stimulus, and (2) although IKCa channel-mediated myoendothelial feedback may contribute to local control of arterial diameter, in the intact vascular bed, increases in shear stress may be the major stimulus for engagement of the endothelium during vasoconstriction. ABSTRACT: Constriction of isolated resistance arteries in response to α1 -adrenoceptor agonists is limited by reciprocal engagement of inhibitory endothelial mechanisms via myoendothelial feedback. In the current model of feedback, agonist stimulation of smooth muscle cells results in localized InsP3 -dependent Ca2+ transients that activate endothelial IKCa channels. The subsequent hyperpolarization of the endothelial membrane potential then feeds back to the smooth muscle to limit further reductions in vessel diameter. We hypothesized that the functional contribution of InsP3 -IKCa channel-mediated myoendothelial feedback to limiting arterial diameter may be influenced by the nature of the vasoconstrictor stimulus. To test this hypothesis, we investigated the functional role of myoendothelial feedback in modulating responses of rat mesenteric resistance arteries to the adrenoceptor agonist noradrenaline, the thromboxane A2 mimetic U46619, increases in intravascular pressure and stimulation of perivascular sympathetic nerves. In isolated arteries, responses to noradrenaline and stimulation of sympathetic nerves, but not to U46619 and increases in intravascular pressure, were modulated by IKCa channel-dependent myoendothelial feedback. In the intact mesenteric bed perfused under conditions of constant flow, responses to exogenous noradrenaline were modulated by myoendothelial feedback, but shear stress-induced release of NO and activation of endothelial SKCa channels appeared to be the primary mediators of endothelial modulation of vasoconstriction to agonists and nerve stimulation. Thus, we propose that myoendothelial feedback may contribute to local control of diameter within arterial segments, but at the level of the intact vascular bed, increases in shear stress may be the major stimulus for engagement of the endothelium during vasoconstriction.

Characterization of a Yariv precipitated arabinogalactan-protein from fruits of rye (Secale cereale L.).

An arabinogalactan-protein (AGP) with a molecular mass of 110 kDa was isolated from whole grain of rye (Secale cereale L.) by double precipitation with (beta-D-Glc)3-Yariv-phenylglycoside (3GlcY) and its structure was analyzed. The AGP consists of a hydroxyproline-rich protein backbone of about 7 % and an arabinogalactan moiety of about 93%. By alkaline hydrolysis, hydroxyproline was identified as the main amino acid responsible for the binding between the protein and the carbohydrate subunits via an O-glycosidic linkage. The arabinogalactan moieties are highly branched consisting of 1,3-linked Galp residues, some of them linked in position 6 to 1,6-Galp side chains, terminating in Araf residues. With regard to its structure, the rye AGP is comparable to other cereal AGPs like those from oat or wheat grain.

[Palliative home care in Westfalia-Lippe--baseline study 12 and 36 months after coming into effect of the "agreement to the implementation of ambulant home palliative careforterminally ill patients"]. / Ambulante Palliativversorgung in Westfalen-Lippe--Strukturierte Bestandsaufnahme 12 und 36 Monate nach Inkrafttreten der "Vereinbarung zur Umsetzung der ambulanten palliativmedizinischen Versorgung von unheilbar Kranken im häuslichen Umfeld".

BACKGROUND: On 2009-04-01 the Association of Statutory Health Insurance Physicians Westfalia-Lippe and health insurance organizations made an agreement to implement palliative home care for terminally ill patients. Based on this agreement, family doctors and palliativecardoctorscooperate,supported by coordinators. METHOD: 12 and 36 months after coming into effect of the agreement a questionnaire was sent to the regional palliative care networks to collect data about supply structure, number of patients and their place of death. RESULTS: In the year 2011 85,410 people died in Westfalia-Lippe, 9.0% of them were included in palliative care structures. 69.5% of the included patients died at home, 9.9% in hospital (in 2010: 68.7% at home, 14.7% in hospital). A correlation between the population density or the number of included patients per palliative networkcould not be detected. CONCLUSION: Low-threshold access to palliative care networks(bothfamilydoctorand patientcancontact the palliative care team at any time) improves ambulant palliative care. Non-bureaucratic change from general home palliative care (German abbreviation: AAPV) to specialized home palliative care (SAPV) has proven successful in Westfalia-Lippe. Well-trained and experienced coordinators guarantee multidisciplinary and multiprofessional working of palliative care teams. In order to enhance palliative care in Westfalia-Lippe, data for quality assurance should be defined, periodically collected and evaluated in the future.

Immunomodulatory effects of arabinogalactan-proteins from Baptisia and Echinacea.

The influences of different arabinogalactan-proteins (AGPs) on proliferation and IgM-production of mouse lymphocytes as well as nitrite- and IL6-production of mouse macrophages were investigated in vitro. AGPs have been isolated and purified from roots of Baptisia tinctoria and Echinacea pallida and suspension culture of Echinacea purpurea. Comparing the AGPs, there are differences with regard to fine structure as well as to activities. AGPs from roots of B. tinctoria and E. pallida show high activity in all test systems. AGP from cell culture of E. purpurea shows no influence on proliferation of mouse lymphocytes, only weak influence on the IgM-production of mouse lymphocytes and weak stimulation of nitrite- and IL6-production in alveolar mouse macrophage culture.

Binding studies of an arabinogalactan-protein from Echinacea purpurea to leucocytes.

Flow cytometric investigations show binding of an isolated arabinogalactan-protein (AGP) from pressed juice of the aerial parts of Echinacea purpurea to the cell surface of human leucocytes. AGP demonstrates binding to lymphocytes, monocytes and granulocytes of different donors (n=8). Competition assays with two antibodies, directed against CD4 and CD8, revealed no interaction of AGP with these receptors, leading to the conclusion that binding of AGP to leucocytes is mediated via other structures.

The arabinogalactan-proteins from pressed juice of Echinacea purpurea belong to the hybrid class of hydroxyproline-rich glycoproteins.

Pressed juices from Echinacea purpurea are used as non-specific immunostimulants, and arabinogalactan-proteins (AGPs) are part of the active principle. An AGP fraction was isolated from pressed juice of E. purpurea by precipitation with ss-glucosyl Yariv reagent, followed by gel-permeation chromatography. Polyclonal antibodies directed against the carbohydrate moiety of this AGP fraction showed a preferential specificity for E. purpurea AGPs from pressed juice over those extracted from E. purpurea suspension culture and other plant species. Native AGPs purified from this AGP fraction by RP-HPLC were then deglycosylated for N-terminal protein sequencing resulting in the identification of three major polypeptides. They show characteristic motifs of classical AGPs but also some features of extensins, suggesting these may be "hybrid" hydroxyproline-rich glycoproteins (HRGPs).

Monoclonal antibodies against an arabinogalactan-protein from pressed juice of Echinacea purpurea.

Pressed juices of the aerial parts of Echinacea purpurea are used as non-specific immunostimulants, and arabinogalactan-proteins (AGPs) have been shown to be part of the active principle. Monoclonal antibodies against an AGP from pressed juice of Echinacea purpurea with complement-stimulating activity have been established by means of hybridoma techniques. To test the specificity of the antibodies, several other arabinogalactan-proteins from suspension cultures of Echinacea purpurea, the roots of Echinacea pallida, the aerial parts of Rudbeckia hirta, the roots of Baptisia tinctoria and gum arabic as well as an arabinogalactan from larch wood were tested in a competitive ELISA for cross reactivities. Chemical modifications at the periphery of the AGP molecules either by reduction of uronic acids or by dearabinosylation had no influence on the reactivity of the molecules towards the antibodies. For further characterization of the epitope, different Ara-Gal-oligosaccharides were used as antigens. A hexasaccharide consisting of a backbone of four molecules of 6-linked beta- D-Gal p, the second and the fourth of them branched at O-2 to an alpha- L-Ara f residue showed weak but reproducible cross reactivity, indicating that the antibodies may be at least in part directed to the carbohydrate moiety of the AGP. Testing of anti-AGP antibodies JIM 8 and LM 2 revealed good reactivity of LM 2 with the Echinacea AGP, whereas Jim 8 showed only very weak interaction.

Characterization of an arabinogalactan-protein isolated from pressed juice of Echinacea purpurea by precipitation with the beta-glucosyl Yariv reagent.

An arabinogalactan-protein (AGP) from pressed juice of Echinacea purpurea herb was isolated from a high molecular weight fraction by precipitation with the beta-glucosyl Yariv reagent, followed by gel-permeation chromatography. It revealed characteristic features of other AGPs: i.e., a high amount of polysaccharide (83%) with a ratio of galactose to arabinose of 1.8:1, some uronic acids (4-5%), and a low protein content (7%) with high levels of serine, alanine and hydroxyproline. The molecular weight was estimated to be 1.2 x 10(6) Da. Linkage and 13C NMR analyses showed that the AGP is composed of a highly branched core polysaccharide of 3-, 6-, and 3,6-linked Galp residues with terminal Araf, GlcAp and terminal units of Araf-(1-->5)-Araf-(1-->. Partial acid hydrolysis resulted in loss of Araf residues at the periphery of the molecule. Complete loss of reactivity toward the beta-glucosyl Yariv antigen was then noticed.

SH3 binding sites of ZG29p mediate an interaction with amylase and are involved in condensation-sorting in the exocrine rat pancreas.

ZG29p, a novel pancreas-specific zymogen granule protein, has been proposed to act as a 'helper protein' in granule formation. To address its function in more detail, we searched for putative binding partners of ZG29p. In zymogen complexes isolated by nondenaturing isoelectric focusing, ZG29p was associated with a protein complex consisting of amylase and cationic trysinogen. Amylase also coeluted with ZG29p after immunoaffinity chromatography using an antibody to recombinant ZG29p. Cross-linking experiments with granule content proteins revealed a direct interaction between recombinant ZG29p and amylase. An interaction was also observed when purified amylase was used, whereas no interaction with recombinant or purified cationic trypsinogen was seen. ZG29p could also be cross-linked to three membrane proteins with molecular masses of 40, 18, and 16 kDa. The binding of ZG29p to amylase and to the membrane proteins was inhibited in the presence of synthetic peptides matching the consensus sequence of proline-rich SH3 binding sites present in ZG29p. The synthetic peptides could be cross-linked to amylase and to three yet unidentified acidic content proteins with molecular masses of about 30 kDa. The peptides also interacted with purified or recombinant amylase, but not with recombinant or purified cationic trypsinogen. In a condensation-sorting assay, the binding (sorting) of zymogen complexes to the granule membrane was reduced in the presence of the peptides. Our results indicate that the interaction of ZG29p with amylase is mediated by SH3 binding domains and that these domains are involved in the sorting of amylase to the granule membrane.

High molecular weight acidic polysaccharides from Malva sylvestris and Alcea rosea.

Leaves and flowers of Malva sylvestris and Alcea rosea (Malvaceae) were compared by determination of the swelling index as well as the content and viscosity of their mucilages. The investigations showed mucilage from flowers of Alcea to be superior to mucilages from leaves or flowers from Malva. High molecular weight acidic polysaccharides (HMWAPs) were isolated from the mucilages of leaves and flowers of both species. The molecular weight of all HMWAPs was in a range of 1.3 to 1.6 x 10(6) D. HMWAP-content in mucilage from flowers of Alcea was highest compared to content in mucilages from leaves or flowers from Malva. HMWAPs were found to be composed mainly of glucuronic acid, galacturonic acid, rhamnose and galactose. Methylation analysis of the carboxyl-reduced and deuterium labeled sugar derivatives of HMWAPs from flowers of Malva sylvestris ssp. mauritiana and Alcea rosea enabled elucidation of the principal structural features of both polysaccharides.

Events which will influence intensive care units in future. A Delphi study.

OBJECTIVE: To find out and analyse the events which are expected to influence the future of Intensive Care Units (ICU). DESIGN: Three round Delphi study. SETTING: In a first preparation round 9 events were defined. In the two rating rounds an international panel of 60 experts heads of ICUs) estimated the time when the events may come true and whether they are desired or not. RESULTS: Computer tools are desired and expected in the near future (before the year 2000) for audit, quality assurance, record keeping and telecommunication; complex closed loops and nursing robots will not be used in clinical routine before 2005, they are not desired.

[The application of microwave energy in preparation of herbal drugs. 2]. / Der Einsatz von Mikrowellenenergie zur Aufbereitung von Arzneidrogen. 2. Mitteilung.

On the basis of various plant organs the relation between the used microwave energy and the drying processes, temperatures of the surface and the interior of the drying materials as well as the remaining moisture in the drugs was investigated. Leaf, flower and herb drugs showed a similar drying behaviour. Plant material of high humidity, e.g. meaty fruits or roots, should be dried by means of pulsed microwave application to avoid too high temperatures. In almost all investigated drugs microwave drying resulted in a lower remaining moisture than air drying. The effect of microwave irradiation on carbohydrates, fats and proteins in plant materials was preliminarily investigated.