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61.
62.
Guillaume Eppe Pauline Peltier Richard Daniellou Caroline Nugier-Chauvin Vincent Ferrières Stéphane P. Vincent 《Bioorganic & medicinal chemistry letters》2009,19(3):814-816
UDP-galactopyranose mutase (UGM) catalyzes the isomerization of UDP-galactopyranose (UDP-Galp) into UDP-galactofuranose (UDP-Galf), an essential step of the mycobacterial cell wall biosynthesis. UDP-(6-deoxy-6-fluoro)-d-galactofuranose 1 was tested as substrate of UGM. Turnover could be observed by HPLC. The kcat (7.4 s?1) and the Km (24 mM) of 1 were thus measured and compared with those of UDP-Galf and other fluorinated analogs. The presence of the fluorine atom at the 6-position had a moderate effect on the rate of the reaction but a huge one on the interactions between the enzyme and its substrate. This result demonstrated that key interactions occur at the vicinity of the 6-position of UDP-galactose in the Michaelis complex. 相似文献
63.
A M Robbe A Peltier F Belleville P Nabet P Paysant 《Comptes rendus des séances de la Société de biologie et de ses filiales》1976,170(6):1256-1262
The authors show that the ovine prolactine promote induction of N. acetyl lactosamine synthetase in tissue culture of mammary glands of pregnant mice. A crude extract of human placenta has also a lactogenic activity as tested by the same method, but in this case the blank values are very high for large concentration of crude extract. The molecular forms of HCS are tested: the slow band has a lactogenic activity, the intermediate band has no activity and the rapid band seems to be inhibitory. 相似文献
64.
V. M. ST.J. READ F.L.S. 《Zoological Journal of the Linnean Society》1988,93(3):225-257
This paper brings together the scattered literature on the Onychophora from Trinidad, Tobago and the Lesser Antilles. The 11 known species from this area are described, incorporating new material collected by the author. Scanning electron micrographs of the dorsal integument are presented for all but one species. Parthenogenesis is reported in a population of Epiperipatus imthurni from Trinidad. 相似文献
65.
NICOLAS S. Piuzzi MASSIMO DOMINICI MARC LONG CECILIA PASCUAL-GARRIDO SCOTT RODEO JOHNNY HUARD JÉROME GUICHEUX RICHARD MCFARLAND LAURIE R. GOODRICH STÉPHANE MADDENS PAMELA G. ROBEY THOMAS W BAUER JOHN BARRETT FRANK BARRY DAVID KARLI CONSTANCE R. CHU DANIEL J. WEISS IVAN MARTIN GEORGE F. MUSCHLER 《Cytotherapy》2018,20(11):1381-1400
The Signature Series Symposium “Cellular Therapies for Orthopaedics and Musculoskeletal Disease Proven and Unproven Therapies—Promise, Facts and Fantasy” was held as a pre-meeting of the 26th International Society for Cellular Therapy (ISCT) annual congress in Montreal, Canada, May 2, 2018. This was the first ISCT program that was entirely dedicated to the advancement of cell-based therapies for musculoskeletal diseases. Cellular therapies in musculoskeletal medicine are a source of great promise and opportunity. They are also the source of public controversy, confusion and misinformation. Patients, clinicians, scientists, industry and government share a commitment to clear communication and responsible development of the field. Therefore, this symposium convened thought leaders from around the world in a forum designed to catalyze communication and collaboration to bring the greatest possible innovation and value to patients with musculoskeletal conditions. 相似文献
66.
Gilles Peltier Laurent Cournac Valérie Despax Bernard Dimon Laurent Fina Bernard Genty Dominique Rumeau 《Planta》1995,196(4):732-739
Carbonic anhydrase activity of intactCommelina communis L. leaves was measured using mass spectrometry, by following the18O-exchange kinetics between18O-enriched carbon dioxide and water. A gas-diffusion model (Gerster, 1971, Planta97, 155–172) was used to interpret the18O-exchange kinetics and to determine two constants, one (k) related to the hydration of CO2 and the other (ke), related to the diffusion of CO2. Both constants were determined inCommelina communis L. leaves after stripping the lower epidermis to remove any stomatal influence. The hydration constant (k) was 17200 +2200 ·min–1 (mean±SD, 12 experiments), i.e., about 8 600 times the uncatalyzed hydration of CO2 in pure water, and was specifically inhibited by ethoxyzolamide, a powerful inhibitor of carbonic anhydrases, half-inhibition occurring around 10–5 Methoxyzolamide. The diffusion constant (ke) was 1.18±0.28·min–1 (mean±SD, 12 experiments) and was only slightly inhibited (about 20%) by ethoxyzolamide. Carbonic anhydrase activity of stripped leaves was not affected by the leaf water status (up to 50% relative water deficits), was strongly inhibited by monovalent anions such as Cl– or NO
3
–
, and decreased by about 50% when the photon flux density during growth was increased from 100 to 500 mol photons·m–2·s–1. By studying the effect of ethoxyzolamide (10–4 M) on photosynthetic O2 exchange, measured using18O2 and mass spectrometry, we found that inhibition of carbonic anhydrase activity by 92–95% had little effect on the response curves of net O2 evolution to increased CO2 concentrations. Ethoxyzolamide had no effect on the photosynthetic electron-transport rate, measured as gross O2 photosynthesis at high CO2 concentration (>350 l·–1), but was found to increase both gross O2 photosynthesis and O2 uptake at lower CO2 levels. The chloroplastic CO2 concentration calculated from O2-exchange data was not significantly modified by ethoxyzolamide. We conclude from these results that, under normal conditions of photosynthesis, most of the carbonic anhydrase activity is not involved in CO2 assimilation. Measurement of carbonic anhydrase activity using18O-isotope exchange therefore provides a suitable model to study the in-vivo regulation of this chloroplastic enzyme in plants submitted to various environmental conditions.Abbreviations CA
carbonic anhydrase
- Ccc
chloroplastic CO2 concentration
- Ce
external CO2 concentration
- EZA
ethoxyzolamide
- k
CO2 hydration rate constant
- ke
CO2 diffusion rate constan
- PPFD
photosynthetic photon flux density
- Rubisco
ribulose-1,5 bisphosphate carboxylase oxygenase
- RWD
relative water deficit
The authors wish to thank P. Carrier for technical assistance with mass-spectrometric experiments and Dr. P. Thibault for helpful suggestions and comments. Dr. A. Vavasseur is gratefully acknowledged for supplyingCommelima communis. cultures. P.C., P.T. and A.V. are all from the CEA, Département de Physiologie Végétale et Ecosystèmes, Cadarache, France. 相似文献
67.
The objective of this study was to determine whether supplemental beta-carotene would influence reproductive function in mares maintained on spring and summer pastures and to characterize plasma carotene concentrations during the estrous cycle. Carotene concentrations in plasma did not vary with day of estrous cycle (P = 0.7455). Mares receiving every other day injections of beta-carotene (400 mg; n = 4) or saline (10 ml; n = 4) during proestrus/estrus did not differ in plasma estradiol (E(2)) concentrations (P = 0.6313), follicle development (P = 0.8068), or plasma progesterone (P(4)) concentrations during the following diestrus (P = 0.4954). Moreover, no differences in plasma P(4) concentrations (P = 0.9047) were detected between mares receiving every other day injections of beta-carotene (400 mg; n = 4) or saline (10 ml; n = 4) during diestrus. However, administration of beta-carotene raised plasma carotene concentrations relative to controls when injected during proestrus/estrus (P = 0.0096) and diestrus (P = 0.0099). Pregnancy rates (P = 0.4900) and number of cycles required for pregnancy (P = 0.2880) were similar for mares administered injections of saline (10 ml; n = 37), beta-carotene (400 mg; n = 37), vitamin A (160,000 IU; n = 38), or vitamin A + beta-carotene (160,000 IU + 400 mg; n = 43), on the first or second day of estrus and on the day of breeding. Therefore, these results collectively suggest that supplemental beta-carotene does not affect the reproductive function of mares fed adequate dietary carotene. Whether supplemental beta-carotene would enhance reproductive function in mares on low carotene diets warrants further investigation. 相似文献
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70.
The numerous data in the International Whaling Statistics relating foetal length to date of catch have been studied. They can be used as alternatives to cube roots of foetal weights to give rates of foetal growth and for the computation of data of conception and foetal ages. There are major differences between the Mysticeti and Odontoceti. The main gestation period for the former is 10.8.±1-2 months and for the latter 14 ± 2 months. In both groups the greatest birth-weight is attained by an increased foetal growth rate, to such an extent in the rorquals that the gestation period in the largest is actually shorter than in the smaller species. There are dietetic and metabolic differences between the two sub-cohorts. The outstanding one is that pregnant mysticetes appear to stop feeding and lose body fat to the foetus during late pregnancy, at the time when the foetal increase in size is maximal. The causes of the differences in growth and metabolism of the two groups are unknown, apart from those imposed by differences in their ecology. 相似文献