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1.
Summary Meta-maleimidobenzoyl derivative of L-thyroxine methyl ester (MBTM) was synthesized and coupled to -galactosidase at molar ratio of over 5 to 1. More than 97% of the enzyme was found to be labeled with MBTM. A thyroxine enzyme immunoassay was carried out with sensitivity in the 0–10 g/100 ml range.  相似文献   

2.
Summary Cortisone acetate (25 g/g b.wt/day) administration to 8-day-old suckling mice induces a premature increase of trehalase activity along the entire small intestine. On the other hand, thyroxine (1 g/g b.wt/day) is unable to provoke a precocious increase of trehalase activity. Trehalase appears to be the only brush border membrane disaccharidase controlled solely by glucocorticoid hormones during the postnatal maturation of the intestine.Supported by grant MA-5969 from the Medical Research Council of Canada to D.M. C.M. is a recipient of a studentship from MRC of Canada.  相似文献   

3.
Summary Daily administration for 3 days of cortisone (25 g/g b.wt), thyroxine (1 g/g b.wt) or insulin (12.5 mU/g b.wt) to 8-day-old suckling mice does not induce a premature decrease of the phosphohydrolase activity of intestinal glucose-6-phosphatase.Supported by grant MA-5969 from the Medical Research Council of Canada (D.M.). C.M. is a recipient of a studentship from MRC of Canada. D.M. is a chercheur-boursier du Conseil de la recherche en santé du Québec.  相似文献   

4.
Summary Infusion of 1 g thyroxine into the left cerebral ventricle of the dog did not change body temperature at rest, but it caused significantly higher increases in Tre during physical exercise.  相似文献   

5.
Summary Yellow phenocopies ofDrosophila melanogaster were produced by raising larvae on -DMT contaminated media. Using a survivorship test, the sensitive period for phenocopy induction was found to occur during the third larval instar of development, with increased survivorship at 1% -DMT compared with lower concentrations. It was also found that treatment with -DMT significantly slowed development. These findings are related to the relevant morphological and behavioral developmental pathways and to phenocopy induction.Publication No. 35 from the Evolutionary Genetics Laboratory, University of Auckland.Acknowledgments. We thank the New Zealand Entomology Society for a grant from their Anniversary Fund to R. D. Newcomb and the University Grants Committee, Research Grant No. 394.597 to D.M. Lambert.  相似文献   

6.
Summary Unconjugated and conjugated bile salts inhibited the conversion of thyroxine to 3,3,5 triiodothyronine in rat liver homogenate.This work was supported in part by a grant from the Imanaga Foundation, Nagoya, Japan.  相似文献   

7.
Résumé On a analysé au moyen d'électrophorèse sur gel d'amidon les protéines qui, dans le sérum humain, lient le fer, le cuivre et l'hormone thyroïdienne, en utilisant comme témoins des protéines purifiées et la radioactivité. Le fer est lié par la -globuline qui, dans certaines familles, paraît se diviser en deux composants. Le cuivre est lié par la céruloplasmine, qui émigre dans la position 2 rapide. La protéine principale liant la thyroxine est la préalbumine.  相似文献   

8.
Summary Induction of -glycosidases by hydrocortisone in suckling rats is inhibited by the daily administration of an antiglucocorticoid (RU-38486). Conversely, RU-38486 injected daily in 15-day-old rats for 7 days does not prevent the spontaneous development of -glycosidases.  相似文献   

9.
Summary The administration of thiocyanate to rats caused a significant increase of serum free thyroxine fraction, which coincided with the significant decrease of TSH level. The other components (AFT4, T4, T3) in serum at this time were decreased or unchanged. The finding suggests the role of free thyroxine fraction in feed-back regulation of TSH secretion.Acknowledgment. We thank Dr A. Parlow and the NIAMDD, Rat Pituitary Hormone Distribution Program, for material for rat TSH immunoassay; Dr J. Nauman (Inst. Postgrad. Med., Warsaw, Poland) for T3 antibody, and to Ing. J. Sadlo, Mrs M. t'astná and Miss R Fajkoová for technical assistance.  相似文献   

10.
Summary Concentration-response curves for the chronotropic and inotropic effects of isoprenaline, in the absence and presence of propranolol, were obtained on heart atria isolated from normo- or dysthyroid rats. Hyperthyroidism increased the chronotropic potency and efficacy of the -adrenergic agonist. The results are compatible with the view that thyroid hormone increases the density of functional -adrenoceptors in cardiac pacemaker tissue.This study was supported by the Swiss National Science Foundation grant No. 3.374.-0.78. We thank Dr Bachmann from the Central Laboratory of the University Hospital Bern for the estimation of plasma thyroxine levels.  相似文献   

11.
Summary Experimental results indicate that rat's paw oedema development by PGs is inhibited by 35 AMP and increased by 35 GMP. This research confirms the opposite effect to that of cyclic nucleotides. The respective behaviour of 35 AMP and 35GMP in their primary oedema-induced activity is discussed.We gratefully acknowledge the technical assistence of Mr.Sauro Pellegrini.  相似文献   

12.
Summary Considerably higher thyroxine and triiodothyronine concentrations in sera of bovine fetuses than in maternal samples were found during the last trimester of pregnancy.Acknowledgment. We wish to thank Miss.R. Fajkoová for skilled technical assistance.  相似文献   

13.
Summary A previous experiment withEranthis showed thatRoentgen irradiation of undivided embryos led to a change in the number of cotyledons. In the present publication, the induction of anomalies of the cotyledon was shown after irradiation of early embryo stages on the mother plant in Arabidopsis thaliana, an example of a plant with complete embryos.Which aberration type (synkotyl, anisokotyl, trikotyl, tetrakotyl or multiple seedlings) will arise, seems to be determined neither by theRoentgen dose nor by the stage of development on irradiation. The appearance of predominately regular trikotyl types after application of 2000r, and their gradual disappearance with increasing doses in favour of the irregular trikotyl types, suggests that in the lower doses the main influences are upon the purely chemical reactions in the embryos, which are overlaid by cell damages occurring in a directly biophysical way with increase of the physical primary acts and lead to irregular growth.

Die Arbeit wurde mit Unterstützung der Deutschen Forschungsgemeinschaft durchgeführt.  相似文献   

14.
Summary The glucose-evoked recovery of Type I thyroxine 5-deiodinase activity in the hepatic microsomes of fasted rat was not inhibited by either cycloheximide, puromycin or actinomycin D during 3 h after glucose feeding; however, [3H]-leucine uptake by the liver or the hepatic microsomal fraction was significantly inhibited by cycloheximide and puromycin but not by actinomycin D. These results indicate that the glucose-evoked recovery of deiodinase activity may be independent of de novo protein synthesis.  相似文献   

15.
Summary Acute treatment with 1-tetrahydrocannabinol (1-THC) elevated the concentration of -endorphin-like immunoreactivity (-ELIR) in plasma and in the hypothalamus, but not in the hippocampus of rats habituated to the injection procedure. These effects were not obtained with the psychotropically inert analog of (1-THC), cannabidiol. In animals that had not been habituated to the injection procedure, placebo treatment induced a decrease in hippocampal -ELIR.The authors acknowledge the skillful technical assistance of Mrs Willeke Logtenberg.  相似文献   

16.
Summary In the astronomical treatise ryabhatya of ryabhata several verses are interpolated, namely all those verses in which either Brahman was mentioned or extremely large periods were introduced. The interpolator was known to AlBrn as ryabhata of Kusumapura, who belongs to the school of the elder ryabhata. The aim of the interpolator was to bring the teaching of the elder ryabhata into accordance with the revelation of Svayambh. Svayambh is another name for Brahm.  相似文献   

17.
Summary The author's purpose is to read the main work of Euclid with modern eyes and to find out what knowledge a mathematician of today, familiar with the works of V. D. Waerden and Bourbaki, can gain by studying Euclid's theory of magnitudes, and what new insight into Greek mathematics occupation with this subject can provide.The task is to analyse and to axiomatize by modern means (i) in a narrower sense Book V. of the Elements, i.e. the theory of proportion of Eudoxus, (ii) in a wider sense the whole sphere of magnitudes which Euclid applies in his Elements. This procedure furnishes a clear picture of the inherent structure of his work, thereby making visible specific characteristics of Greek mathematics.After a clarification of the preconditions and a short survey of the historical development of the theory of proportions (Part I of this work), an exact analysis of the definitions and propositions of Book V. of the Elements is carried out in Part II. This is done word by word. The author applies his own system of axioms, set up in close accordance with Euclid, which permits one to deduce all definitions and propositions of Euclid's theory of magnitudes (especially those of Books V. and VI.).In this way gaps and tacit assumptions in the work become clearly visible; above all, the logical structure of the system of magnitudes given by Euclid becomes evident: not ratio — like something sui generis — is the governing concept of Book V., but magnitudes and their relation of having a ratio form the base of the theory of proportions. These magnitudes represent a well defined structure, a so-called Eudoxic Semigroup with the numbers as operators; it can easily be imbedded in a general theory of magnitudes equally applicable to geometry and physics.The transition to ratios — a step not executed by Euclid — is examined in Part III; it turns out to be particularly unwieldy. An elegant way opens up by interpreting proportion as a mapping of totally ordered semigroups. When closely examined, this mapping proves to be an isomorphism, thus suggesting the application of the modern theory of homomorphism. This theory permits a treatment of the theory of proportions as developed by Eudoxus and Euclid which is hardly surpassable in brevity and elegance in spite of its close affinity to Euclid. The generalization to a classically founded theory of magnitudes is now self-evident.

Vorgelegt von J. E. Hofmann  相似文献   

18.
19.
The paper reports on the molecular analysis of samples of approximately 5,300-year-old grass found at the alpine archaeological site where the so-called Tyrolean Iceman was discovered. The grass comes from a cloak made of long grass blades and/or the stuffing of the snow footwear worn by the Iceman. The results show that while the largest fraction of the DNA extractable from the grass is of foreign origin, a much smaller part belongs to the original genetic material of the grass itself, and can be used as a valuable taxonomic clue to the plant species utilized by neolithic men to manufacture their equipment. On the other hand, the foreign DNA, or at least a portion of it, comes from microorganisms-mainly filamentous fungi and unicellular algae-which seem to have been associated with the grass since the time the grass was harvested.  相似文献   

20.
Summary An ectomycorrhiza, a specialized root organ, is the result of a complex interaction leading to a finely-tuned symbiosis between a plant and a compatible ectomycorrhizal fungus. Ultrastructural observations combined with cytochemical and biochemical studies reveal that structural and metabolic changes in the symbiont cells lead to the final phenotype of the active ectomycorrhiza. In the present review these changes are interpreted as changes in gene expression and discussed within the context of ectomycorrhiza development. Recent genetic data indicate that the continued vegetative growth of the ectomycorrhizal hyphae and the root tissues, and their ability to switch to symbiotic organ formation, is basically controlled by developmentally critical genes. The activity of these symbiotic genes during the differentiation of ectomycorrhizas is associated with extensive changes in the concentration of particular polypeptides and protein biosynthesis. The present state of knowledge about the developmental biology of ectomycorrhizas allows only speculation about the events during their development.Puisant mes forces aux sources des galaxies En buvant la sève des arbres M. Jonasz  相似文献   

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