Abstract: CCL25 (also known as thymus-expressed chemokine) and CCL28 (also known as mucosae-associated epithelial chemokine) play important roles in mucosal immunity by recruiting IgA Ab-secreting cells (ASCs) into mucosal lamina propria. However, their exact roles in vivo still remain to be defined. In this study, we first demonstrated in mice that IgA ASCs in small intestine expressed CCR9, CCR10, and CXCR4 on the cell surface and migrated to their respective ligands CCL25, CCL28, and CXCL12 (also known as stromal cell-derived factor 1), whereas IgA ASCs in colon mainly expressed CCR10 and CXCR4 and migrated to CCL28 and CXCL12. Reciprocally, the epithelial cells of small intestine were immunologically positive for CCL25 and CCL28, whereas those of colon were positive for CCL28 and CXCL12. Furthermore, the venular endothelial cells in small intestine were positive for CCL25 and CCL28, whereas those in colon were positive for CCL28, suggesting their direct roles in extravasation of IgA ASCs. Consistently, in mice orally immunized with cholera toxin (CT), anti-CCL25 suppressed homing of CT-specific IgA ASCs into small intestine, whereas anti-CCL28 suppressed homing of CT-specific IgA ASCs into both small intestine and colon. Reciprocally, CT-specific ASCs and IgA titers in the blood were increased in mice treated with anti-CCL25 or anti-CCL28. Anti-CXCL12 had no such effects. Finally, both CCL25 and CCL28 were capable of enhancing α4 integrin-dependent adhesion of IgA ASCs to mucosal addressin cell adhesion molecule-1 and VCAM-1. Collectively, CCL25 and CCL28 play essential roles in intestinal homing of IgA ASCs primarily by mediating their extravasation into intestinal lamina propria.

Abstract: In der Offenstallhaltung von Pferden wird für die individuelle Fütterung der Fressstand, der eine art-typische synchrone Nahrungsaufnahme erlaubt, empfohlen (BMELV 2009). Seit einigen Jahren kommen jedoch vermehrt Abrufstationen für Kraft- und Raufutter zum Einsatz. Diese ermöglichen nur ein asynchrones Fressen, was das Risiko für Auseinandersetzungen im Fressbereich erhöht.
In einer repräsentativen Studie an insgesamt 567 individuell unterschiedenen Pferden in 32 Offen-laufställen mit Abrufstationen und 10 Betrieben mit Fressständen wurden die Aufenthaltsdauer und Besuchshäufigkeit sowie das Droh- und Meideverhalten der Pferde im Fütterungsbereich und die Häu-figkeit von Blockaden erfasst, des Weiteren Herzfrequenz und Integumentverletzungen. Fazit war, dass es an den Abrufstationen doppelt so oft zu Auseinandersetzungen kam als an den Fressständen. Als Ursache hierfür konnte die starke Frequentierung der Automaten eruiert werden. Umso wichtiger ist somit die tiergerechte Ausführung der Abrufautomaten. In der Studie konnte nachgewiesen werden, dass Durchlaufstationen pferdegerechter sind als Rücklaufstationen. Als nicht tiergerecht wurden Stationen mit Strom führender Austreibehilfe.eingestuft. Die für das fressende Pferd als verhaltens-gerecht empfohlene Variante (Fressstand mit Eingangssperre und ohne Austreibehilfe) führte zu einer Erhöhung der Besuchshäufigkeit und Aufenthaltsdauer und somit auch zu einer erhöhten Anzahl an Drohgesten je Tier und Tag. Die Herzfrequenz lag im Wartebereich bei den meisten Pferden im physio-logischen Bereich (45,1 ± 12,42 Schläge/min), erhöhte sich jedoch in der Abrufstation um ca. 20 Schlä-ge/min. Einige Tiere zeigten möglicherweise stressbedingt auffallend hohe Herzfrequenzwerte ( 100 Schläge/min). Integumentverletzungen im Zusammenhang mit dem Fütterungssystem traten nicht auf. Das Flächengebot und die Konzeption der Offenstallanlage sowie das Management erwiesen sich als maßgebliche Einflussfaktoren auf alle überprüften Kriterien zur Tiergerechtheit.
Um die Anzahl an Auseinandersetzungen im Fütterungsbereich von Abrufstationen zu mindern wird eine Reduzierung der Fütterungshäufigkeit von üblicherweise bis zu 24 Mahlzeiten auf nur 10 Mahlzeiten empfohlen, gemäß dem natürlichen Fressrhythmus von Pferden. Unabhängig vom Fütterungssystem traten die wenigsten Auseinandersetzungen auf, wenn die Pferde täglich etwa 1,5 kg Heu pro 100 kg Körpermasse erhielten bei zusätzlicher ad Libitum Fütterung von Stroh.
Nach bisherigen Erkenntnissen ergeben sich nachfolgende Checkpoints für Abrufautomaten:
Checkpunkte für Abrufstationen
 Schutz des Pferdes durch Trennwände über die gesamte Körperlänge
 Trennwände mit Sichtkontakt zu den anderen Pferden
 Durchlaufstationen mit separatem Ein- und Ausgang
 Eingangssperre für eine stressfreie Futteraufnahme
 Ausgang mit Pendeltüre und Rücklaufsperre
 Ausgang in einen anderen Funktionsbereich
 Ausreichend Ausweichmöglichkeiten für rangniedere Tiere
 Räumliche Trennung von Kraftfutter- und Heuautomaten
 Maximal je 10 Kraft- und Grobfutterrationen je Tier und Tag
 ≥ 1,5 kg Heu bzw. Heulage pro 100 kg Körpermasse je Pferd und Tag
 Stroh zur freien Verfügung (Möglichkeit zum synchronen Fressen)
 Individuelles Anlernen der Pferde am Automaten erforderlich

Abstract: Several years ago, Theorell and Czerlinski conducted experiments on the system of horse liver alcohol dehydrogenase, reduced nicotinamide adenine dinucleotide and imidazole, using the first version of the temperature jump apparatus with detection of changes in fluorescence. These early experiments were repeated with improved instrumentation and confirmed the early experiments in general terms. However, the improved detection system allowed to measure a slight concentration dependence of the relaxation time of around 3 ms. Furthermore, the chemical relaxation time was smaller than the one determined earlier (by factor 2). The data were evaluated much more rigorously than before, allowing an appropriate interpretation of the results. The observed relaxation time is largely due to rate constants in an interconversion of ternary complexes, which are faster than three (of the four) dissociation rate constants, determined previously by Theorell and McKinley-McKee.1,2 This fact contributed to earlier difficulties of finding any concentration dependence. However, the binding of imidazole to the binary enzyme-coenzyme complex can be made to couple kinetically into the interconversion rate of the two ternary complexes. The observed signal derives largely from the ternary complex(es). A substantial fluorescence signal change is associated with the observed relaxation process, suggesting a relocation of the imidazole in reference to the nicotinamide moiety of the bound coenzyme. Nine models are considered with two types of coupling of pre-equilibria (none-all). Quantitative evaluations favor the model with two ternary complexes connected by an interconversion outside the four-step (bimolecular) cycle. The ternary complex outside the cycle has much higher fluorescence yield than the one inside. The interconversion equilibrium is near unity for imidazole. If it would be shifted very much to the side of the “dead-end” complex (as in isobutyramide?!), stimulating action could not take place.

Abstract: Profound neuroplastic changes have been demonstrated in various limbic structures after chronic stress exposure and antidepressant treatment in animal models of mood disorders. Here, we examined in rats the effect of chronic social stress and concomitant antidepressant treatment on cell proliferation in the medial prefrontal cortex (mPFC). We also examined possible hemispheric differences. Animals were subjected to 5 weeks of daily social defeat by an aggressive conspecific and received concomitant, daily, oral fluoxetine (10 mg/kg) during the last 4 weeks. Bromodeoxyuridine (BrdU) labeling and quantitative stereological techniques were used to evaluate the treatment effects on proliferation and survival of newborn cells in limbic structures such as the mPFC and the hippocampal dentate gyrus, in comparison with nonlimbic structures such as the primary motor cortex and the subventricular zone. Phenotypic analysis showed that neurogenesis dominated the dentate gyrus, whereas in the mPFC most newborn cells were glia, with smaller numbers of endothelial cells. Chronic stress significantly suppressed cytogenesis in the mPFC and neurogenesis in the dentate gyrus, but had minor effect in nonlimbic structures. Fluoxetine treatment counteracted the inhibitory effect of stress. Hemispheric comparison revealed that the rate of cytogenesis was significantly higher in the left mPFC of control animals, whereas stress inverted this asymmetry, yielding a significantly higher incidence of newborn cells in the right mPFC. Fluoxetine treatment abolished hemispheric asymmetry in both control and stressed animals. These pronounced changes in gliogenesis after chronic stress exposure may relate to the abnormalities of glial cell numbers reported in the frontolimbic areas of depressed patients.

Abstract: Rats were exposed to a radial maze containing six black smooth arms and six wire-grid-covered arms and a striped 'exit arm' in experiment 1. The probability of a black or grid arm being baited (5/6 vs 1/6) with sunflower seeds was associated with its proximal cue for some rats (the Relevant Arm Cue group) but not for others (the Irrelevant Arm Cue group). All rats could terminate a trial and receive a highly preferred morsel of apple by entering the exit arm only after having sampled all six seed-baited arms. Relevant Arm Cue rats usually chose some arms from the more densely baited set before choosing an arm from the less densely baited set and made fewer reentries than Irrelevant Arm Cue rats. Although such clustered, higher choice accuracy in the Relevant Arm Cue group corresponds to human clustered, better recall of verbal items from lists hierarchically organized by categories, these rats did not similarly exhaustively retrieve items (arm locations). That is, when required to terminate a trial by entering the 'exit' arm for an apple morsel after having sampled all seed-baited arms, both groups were equally unable to withhold making nonrewarded premature exits. This nonexhaustive foraging search pattern was maintained in the next two experiments in which the radial maze was reduced to three black and three grid arms along with the striped 'exit' arm and in which black and grid arm cues were paired with number of seeds (eight or one) in an arm for Relevant Arm Cue rats. Although Relevant Arm Cue rats displayed perfect clustering by entering all eight-seeded arms before a one-seeded arm, they made more premature exits and reentries into eight-seeded arms in experiment 2 or when forced to enter all eight-seeded arms in experiment 3 than did Irrelevant Arm Cue rats. These foraging tendencies prevent accurate estimations of the amount of information (i.e., arm locations) rats can 'chunk'.