Involvement of D-amino acid oxidase in elimination of D-serine in mouse brain

The physiological role of D-amino acid oxidase (EC 1. 4. 3. 3) in mouse brain is described. The presence of D-enantiomers of neutral common amino acids was surveyed in the brain. D-serine was shown to be present at high concentration only in regions where the enzyme activity was low. In normal mice whose D-amino acid oxidase activity was much higher in the cerebellum than in the cerebrum, free D-serine content was apparently lower in the cerebellum than in the cerebrum. In mice of a mutant strain lacking D-amino acid-oxidase activity, the free D-serine level was remarkably high both in the cerebrum and cerebellum. The results suggest that the enzyme is involved in the elimination of free D-serine in the cerebellum.     

Involvement of D-amino acid oxidase in elimination of D-serine in mouse brain.

The physiological role of D-amino acid oxidase (EC 1. 4. 3. 3) in mouse brain is described. The presence of D-enantiomers of neutral common amino acids was surveyed in the brain. D-serine was shown to be present at high concentration only in regions where the enzyme activity was low. In normal mice whose D-amino acid oxidase activity was much higher in the cerebellum than in the cerebrum, free D-serine content was apparently lower in the cerebellum than in the cerebrum. In mice of a mutant strain lacking D-amino acid-oxidase activity, the free D-serine level was remarkably high both in the cerebrum and cerebellum. The results suggest that the enzyme is involved in the elimination of free D-serine in the cerebellum.     

Collagenolytic activity of eosinophilic granuloma in vitro.

Lytic activity of eosinophilic granuloma and other tumours was studied in vitro on collagen substrate. Collagen degradation was measured through the release of hydroxyproline-rich peptides into the medium. The in vitro lytic action was at a maximum in the case of EG and was correlated with the presence of histiocytic cells.     

Frühe Stadien der Erholung bei bestrahlten ratten und Mäusen

Summary A split dose experiment was performed in 12-, 24- or 32-day-old Wistar rats. About 4000 animals were used. The first dose given was 200 R whole-body X-irradiation in the 2 younger groups, and 260 R in the oldest group. At intervals from 6–48 h after the first, a second irradiation was given in order to estimate the LD50(30). No recovery was seen in terms of the LD50(30) differences between preirradiated and normal animals 6 h after the first dose. At the 12 h interval marked recovery was found in all 3 age groups, but less recovery was apparent at the later intervals.     

Nociception,neurogenic inflammation and thermoregulation in TRPV1 knockdown transgenic mice

Transgenic mice with a small hairpin RNA construct interfering with the expression of transient receptor potential vanilloid 1 (TRPV1) were created by lentiviral transgenesis. TRPV1 expression level in transgenic mice was reduced to 8% while the expression of ankyrin repeat domain 1 (TRPA1) was unchanged. Ear oedema induced by topical application of TRPV1 agonist capsaicin was completely absent in TRPV1 knockdown mice. Thermoregulatory behaviour in relation to environmental thermopreference (30 vs. 35°C) was slightly impaired in male knockdown mice, but the reduction of TRPV1 function was not associated with enhanced hyperthermia. TRPV1 agonist resiniferatoxin induced hypothermia and tail vasodilatation was markedly inhibited in knockdown mice. In conclusion, shRNA-mediated knock down of the TRPV1 receptor in mice induced robust inhibition of the responses to TRPV1 agonists without altering the expression, gating function or neurogenic oedema provoked by TRPA1 activation. Thermoregulatory behaviour in response to heat was inhibited, but enhanced hyperthermia was not observed.     

Peroxidase activity in mitochondria of Prototheca moriformis

Summary Peroxidase activity was investigated by the use of diaminobenzidine method in fixed cells of Prototheca moriformis. A strong peroxidase activity was observed in the mitochondria. DAB staining was unaffected by KCN, aminotriazole and antimycin A, but it was completely inhibited by methanol-nitroferricyanide.     

Cholinesterase in the atherosclerotic intima and in fibroblast cultures

Summary Cholinesterase activity was present in the atheromatous plaque of the rabbit's atherosclerotic aorta. Cholinesterase activity was significantly increased in rat fibroblast cultures grown in the presence of hypercholesterolemic serum. Cholesterol ester synthesis in these cultures was inhibited by neostigmine, a cholinesterase inhibitor.Acknowledgments. We thank Patricia Fontaine for technical assistance and Patricia Candow and Barbara English for secretarial help. This work was supported by a grant from the Canadian Heart Foundation. Part of this work was presented at 1977 annual meeting of the Biochemical Society in London.     

Intercellular dye-coupling in intestinal smooth muscle. Are gap junctions required for intercellular coupling?

Summary The dye Lucifer Yellow was injected into single smooth muscle cells in the guinea pig small intestine in order to study intercellular coupling. Dye-coupling was observed in both the circular and longitudinal muscle layers and was markedly reduced when the intercellular pH was lowered. These results suggest the presence of gap junctions among intestinal muscle cells, but are inconsistent with previous ultrastructural studies that failed to demonstrate such junctions in the longitudinal muscle.     

Das Verhalten des Quotienten Harnstoff-N:Rest-N bei normalen und nephrektomierten,urämischen Ratten

Summary (1) The quotient urea nitrogen: non-protein nitrogen was determined in nephrectomized uremic rats and compared with the quotient in control animals. The quotient in nephrectomized uremic animals was 0.74, in control animals 0.35. The elevation of the quotient is of hepatic origin.(2) The desamination was increased in the liver of nephrectomized uremic animals in comparison to controls; the urea production was unchanged.     

The electron microscopy of fluorescent dextrans (FITC-dextrans) in thin sections of tissue

Summary Fluorescein-coupled dextrans (FITC-Ds) were detected in sections in the electron microscope using 4 different contrasting methods when tissue was postfixed in osmium tetroxide. Endogeneous glycogen was also stained by the methods used, but FITC-D particles appeared smaller and more irregular, and in other locations. In dextranase treated specimens glycogen was still visible, while FITC-D was not.Acknowledgments. The author is grateful to Susan Max-Jacobsen, Kjeld Stub and Sonja Fich for excellent technical assistance. The author was supported by a research fellowship from the Danish Medical Research Council (12–1688).     

Diurnal change in stature: effects of sleep deprivation in young men and middle-aged men

Summary Sleep deprivation was associated with decreased stature and it blunted the normal 24-h rhythm in young and in middle-aged men. Loss in stature was regained during the first recovery night of sleep. The 24-h rhythm in height is not an endogenous circadian rhythm but depends upon the periods of recumbency over the sleep/wake cycle.Acknowledgments. The first author was a Medical Research Council scholar; the second was supported by the Scottish Hospital Endowments Research Trust.     

Neural discharge can be modulated by carotid arterial injection of gastrin-17 in rat hypothalamic paraventricular nucleus

Neural discharge in the hypothalamic paraventricular nucleus (PVN) was examined after gastrin-17 injection into the carotid artery in anesthetized rats. Neural discharge was increased by gastrin-17 injection into the carotid artery close to the cranium, and the response due to the gastrin was dose-dependent. No discharge response was seen when gastrin was injected into the jugular vein. These results suggest that gastrin circulating in the arterial blood can penetrate the blood brain barrier, and modulate neural PVN activity which is responsible for gastric acid secretion.     

Brain catecholamines and sleep states in offspring of caffeine-treated rats

Summary Caffeine was administered in the diet to rats throughout gestation. In the 2 consecutive untreated generations, an increase of parodoxical sleep was observed at maturity. In the 1st generation, the dopamine level was markedly reduced in the locus coeruleus, whereas that of noradrenaline remained constant. The effect was less pronounced in the 2nd generation.     

Opsonic activity against zymosan of normal human serum of different blood types

Summary Serum opsonic activity against zymosan was found to be decreased more markedly in highly diluted O type serum than in the other 3 types, among which no difference was noted. Heat-killed bacteria were equally well opsonized with any type of serum. This peculiar activity of O type serum against zymosan was not affected by the removal of isohemagglutinins. No inhibitory activity was demonstrable in O type serum.This work was supported in part by a Grant-in-Aid from the Japan Medical Research Foundation and Grants-in-Aid (Project Nos. 157253 and 544050) from the Ministry of Education, Science and Culture of Japan.     

Cholinesterase in the atherosclerotic intima and in fibroblast cultures.

Cholinesterase activity was present in the atheromatous plaque of the rabbit's atherosclerotic aorta. Cholinesterase activity was significantly increased in rat fibroblast cultures grown in the presence of hypercholesterolemic serum. Cholesterol ester synthesis in these cultures was inhibited by neostigmine, a cholinesterase inhibitor.     

The union of arts and sciences in the eighteenth century: Lorenz Spengler (1720–1807), artistic turner and natural scientist

The life and career of Lorenz Spengler (1720–1807) provides evidence to support the view that the eighteenth century was a period when there was a fruitful interrelationship between the arts, crafts, and sciences in the courts and capitals of Europe. Spengler was trained as a turner, and was appointed teacher of ornamental turning to the Danish royal family and turner of the court in 1745. Even in the early years of his artistic career Spengler was interested in electricity and its role in healing, and he became an avid collector of shells and naturalia. Over the years, Spengler's interests turned more to the natural sciences, and in 1771 he was appointed director of the King's Kunstkammer. Only by considering both aspects of Spengler's career can his scientific activities be placed in their proper historical context.     

Differential alterations in branched-chain amino acid decarboxylation in liver of hypophysectomized rats

Summary Valine decarboxylation was significantly increased and leucine decarboxylation was significantly decreased in rat liver slices following hypophysectomy. In both normal and hypophysectomized rats decarboxylation of leucine exceeded that of valine in slices whereas the reverse was observed with the respective keto acids and mitochondria.Acknowledgments. This study was supported by the National Institutes of Health and the Samuel A. Berger Foundation.     

Translocation of hepatic cytosol androgen receptor to the nucleus in vivo in male rats

Summary Testosterone, which was injected s.c. into adult male rats castrated 15 h prior to the injection, decreased the number of androgen-specific binding sites in the cytosol at 30 min. Coincidentally, a substantial increase was observed in the nucleus. The decreased number of the sites in the cytosol was restored to the initial level at 60 min; on the contrary, a decrease was observed in the nucleus.     

Y型明渠交汇水流分离区的数值分析

针对Y型明渠交汇口的水流特性，应用三维各向异性的雷诺应力模型，采用交错网格上的有限体积法离散控制方程，用SIMPLE算法求解压力-速度场。数值计算结果与物理模型试验结果吻合较好，并据此重点探讨了不同交汇角条件下交汇口分离区尺寸的变化规律，提出Y型交汇水流分离区的定义和分离区尺寸与汇流比的函数关系。     

Distribution of glycerophosphorylcholine diesterase in rat brain.

The distribution of glycerylphosphorylcholine diesterase in the rat brain has been examined. The enzyme was evenly distributed throughout the brain but was localized in the synaptosome (nerve ending) fraction which was prepared by ultracentrifugation.