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Notes: Summary A psychiatric unit that is characterized by rapid staff and patient turnover was studied longitudinally on four occasions at 6-week intervals, using measures of ward atmosphere, ward activities, perception of patients, and population characteristics. Although the ward did show a great deal of change demographically, perceptions of it were highly stable for patient and staff groups. It was further shown that, in addition to stable perceptions of specific activities or aspects of the milieu, there were also broader underlying perceptual dimensions that were consistent across time. Stable staff-versus-patient and intra-staff differences in perceptions were also found. The results are discussed in terms of the factors that might contribute to the maintenance of such a stable environment, and in terms of the importance of attending to individual variations in perceptions of ward atmosphere.

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Notes: Conclusion The high potency of the small intestine to inactivate vasoactive biogenic amines is a combined effect of diamine and monoamine oxidase activity. Histamine, however, is specifically deaminated by diamine oxidase.

Notes: Summary The effects of ramp stretches applied to triceps surae muscle on the discharge patterns of single Ia inhibitory interneurones, monosynaptically invaded from various nerves, were studied in either decerebrate or anesthetized cats. Interneurones which received direct excitatory Ia input from the stretched muscle exhibited augmented activity both during the dynamic and static phase of stretch, which was, however, interrupted by a transient inhibitory influence during the dynamic phase of stretch. The influences on Ia inhibitory interneurones, monosynaptically invaded from hamstring or tibial nerve, were exclusively inhibitory. These stretch-induced inhibitions were better demonstrable in decerebrate than in anesthetized preparations. The timing of the discharge patterns of additionally recorded Renshaw cells during stretch, and the disappearance or reduction of the above described inhibitory effects after administration of DHE, strongly support the idea that these inhibitory actions are caused by Renshaw inhibition. In Ia inhibitory interneurones, monosynaptically activated from the antagonistic peroneal nerve, stretch induced also pronounced inhibitory effects, which were most probably caused by mutual inhibition between Ia inhibitory interneurones. The suppression of agonistic Ia inhibitory interneurone activity below the tonic resting activity corresponded to an enhancement of the monosynaptic reflex amplitude of the antagonistic motoneurone pool. The findings suggest that normal orthodromic activation of Renshaw cells, and consequently the recurrent inhibition of the Ia inhibitory interneurones, is predominantly linked with rapid phasic, rather than slow tonic, motoneuronal firing. The functional role of this mechanism for the performance of rapidly alternating movements and the damping of ballistic agonist contractions is discussed.

Notes: Summary Peptidases capable of releasing proline residues from polypeptides are present in the cytoplasmic fraction of rabbit polymorphonuclear granulocytes. This was shown with peptide substrates where proline is present either at the carboxy-terminal or within the polypeptide chain. Lysosomal and plasma membrane enzymes were inactive towards such polypeptides. The proline residue was hydrolyzed at either its amino end or its carboxy end. It is noteworthy that a Pro:Pro bond was cleaved both in the pentapeptide Thr-Lys-Pro-Pro-Arg and the dipeptide Pro:Pro.

Notes: Zusammenfassung Die folgenden Feststellungen beziehen sich, soweit nicht anders vermerkt, auf die lebende Sagitta setosa. 1. In den dorsalen und ventralen Muskelbändern (auch anderer Chaetognathen: s. W. J. Schmidt 1928; 1930) lassen sich zwischen gekreuzten Nicols doppelbrechende Lipoide nachweisen, in einer Anhäufung, die bei Wirbellosen bisher einzig dasteht: sie füllen einerseits als ausgedehnte Längsstreifen die Spalten zwischen den Bündeln der Muskelblätter und finden sich anderseits als kürzere aber breitere spindelförmige Gebilde mit der Längsachse der Faserung parallel, dicht gedrängt an der Innenfläche der Muskelblätter. Beiderlei Bildungen, die sich also innerhalb des Coelomepithels bzw. der davon gelieferten Muskellage befinden, wirken optisch negativ zum Faserverlauf. Mit der Lösung der Lipoide durch Alkohol oder nach Zugabe von Osmiumsäure verschwinden die geschilderten Doppelbrechungserscheinungen. 2. In den lateralen Muskelbändern (gleiches dürfte für die medianen gelten, obwohl hier eine Prüfung nicht möglich war) treten ebenfalls doppelbrechende Lipoide auf, wohl in Längsspalten der kontraktilen Masse gelegen. Sie verleihen den 2 J-Gliedern der Fasern negative Doppelbrechung, und zwar stärkere als die positive der Q-Glieder. Unter der Wirkung von Alkohol und Osmiumsäure stellt sich das vom fixierten Präparat bekannte optische Verhalten ein, nämlich stärker doppelbrechende positive Q-Glieder und nur sehr schwach positiv doppelbrechende 2 J-Glieder. Mit dem Absterben der lateralen Muskelbänder kommt es zu der am Dauerpräparat zu beobachtenden auffallenden Unregelmäßigkeit im Abstand der Q-Glieder. 3. Die Flossenstrahlen wirken positiv doppelbrechend zur Länge; Phenole beeinflussen ihr optisches Verhalten nicht; auch thermische Verkürzung läßt sich an ihnen nicht auslösen; ihr Material ist daher nicht kollagenartiger Natur. Gelegentlich fanden sich längs den Strahlen geordnet stäbchenartige doppelbrechende Lipoidgebilde von negativem Vorzeichen. 4. Die Sinneshaare auf den Tastorganen sind positiv doppelbrechend zur Länge; dies gilt sowohl für Haarbüschel als auch für Tastborsten. 5. Die Greifhaken zeigen schon im lebendfrischen Zustande die anomalen Polarisationsfarben, die für das fixierte Material bekannt sind und auf Kompensation von Form- und Eigendoppelbrechung hinweisen (W. J. Schmidt, 1941); wie am fixierten Material, so ruft auch am lebendfrischen der durch Zerdrücken hervorgerufene fibrilläre Zerfall der „Bänder“ kräftige positive Doppelbrechung hervor. 6. Die von verschiedenen Forschern hervorgehobene eigentümliche homogene Beschaffenheit des Cytoplasmas der Epidermiszellen beruht, wie das Polarisationsmikroskop bei Sagitta hexaptera zeigt, auf der mächtigen Entwicklung von doppelbrechendem Material, das am Querschnitt des Tieres positiv zur Tangente wirkt und als Wandlung des Cytoplasmas in eine tonofibrillenartige Masse aufzufassen ist. Die eigenartig zackigen Umrisse der Epidermiszellen in Flächenansicht kommen durch den Übertritt von Tonofibrillen. aus einer Zelle in die benachbarten zustande.

Notes: Summary For the system tert-butyl acetate/polystyrene (M= 670000) the phase separation behaviour (upper critical solution temperatures, upper critical solution pressures) is investigated by means of visual and turbidimetric cloud-point measurements and by viscometry. For near-critical concentrations the visually determined cloud-points are found at higher, for low concentrations at lower temperatures as compared with the turbidimetrically determined binodal temperature,T bin Plots of the invers of the turbidity measured atT bin as a function of the polymer concentration,w 2 , yield a minimum from which the critical composition can be determined. The viscometrically obtained demixing points (break-down of the viscosity at normal and at elevated pressures) show that the polymer solutions are stabilized at moderate concentrations. Irrespective of the preselected temperatures and of the present shear-rates (90-640 s−1, the demixing pressures are reduced by almost 20 bar. At sufficiently dilute or concentrated solutions the viscometric demixing points approach the binodal points. The above influences of the shear-field are explained by the rupture of intermolecular segment/segment contacts, which will be most efficient in the neighbourhood of the critical concentration for the formation of entanglements. In the case of the homogeneous solutions, the viscosity coefficientn increases in a fairly exponential manner by a factor of 3-4 per 1000 bar within the range ofp,T,w 2 and shear-rate under investigation (1–1000 bar, -25 to f20 °C, 4–10 wt-% and 25–640 s−1). In plots of logn or ofV* (volume of activation) vs. concentration, extra effects show up when the critical conditions are approached; they result in a “hump” in logn vs.wn2 and in a minimum in V* vs.w 2 .