120 research outputs found
Stimulation of glucose transport in osteoblastic cells by parathyroid hormone and insulin-like growth factor I
Insulin and parathyroid hormone (PTH) regulate glucose metabolism in bone cells. In order to differentiate between the effects of these hormones and to compare the potency of insulin with that of insulin-like growth factor (IGF) I, we treated rat bone-derived osteoblastic (PyMS) cells for different time periods and at different concentrations with insulin, IGF I, or PTH, and measured [1-14C]-2-deoxy-d-glucose (2DG) uptake and incorporation of d-[U-14C] glucose into glycogen. 2DG uptake was Na-independent with an apparent affinity constant (K M) of ~2mmol/l. Expression of the high affinity glucose transporters (GLUT), GLUT1 and GLUT3 but not of GLUT4, was found by Northern and Western analysis. Similar to the findings with primary rat osteoblasts, but distinct from those in rat fibroblasts, 2DG uptake and glycogen synthesis were increased in this cell line after exposure to low concentrations (0.1nmol/l and above) of PTH. IGF I at low doses (0.3nmol/l and above) or insulin at higher doses (1nmol/l and above) stimulated 2DG uptake and [3H] thymidine incorporation into DNA. 2DG transport was enhanced already after 30min of IGF I treatment whereas the effect of PTH became significant after 6h. It is concluded that IGF I rather than insulin may be a physiological regulator of 2DG transport and glycogen synthesis in osteoblast
Selenium-dependent antioxidant enzymes: Actions and properties of selenoproteins
Unlike other essential trace elements that interact with proteins in the form of cofactors, selenium (Se) becomes co-translationally incorporated into the polypeptide chain as part of 21st naturally occurring amino acid, selenocysteine (Sec), encoded by the UGA codon. Any protein that includes Sec in its polypeptide chain is defined as selenoprotein. Members of the selenoproteins family exert various functions and their synthesis depends on specific cofactors and on dietary Se. The Se intake in productive animals such as chickens affect nutrient utilization, production performances, antioxidative status and responses of the immune system. Although several functions of selenoproteins are unknown, many disorders are related to alterations in selenoprotein expression or activity. Selenium insufficiency and polymorphisms or mutations in selenoproteins’ genes and synthesis cofactors are involved in the pathophysiology of many diseases, including cardiovascular disorders, immune dysfunctions, cancer, muscle and bone disorders, endocrine functions and neurological disorders. Finally, heavy metal poisoning decreases mRNA levels of selenoproteins and increases mRNA levels of inflammatory factors, underlying the antagonistic effect of Se. This review is an update on Se dependent antioxidant enzymes, presenting the current state of the art and is focusing on results obtained mainly in chicken
Between a Rock and a Hard Place: Habitat Selection in Female-Calf Humpback Whale (Megaptera novaeangliae) Pairs on the Hawaiian Breeding Grounds
The Au'au Channel between the islands of Maui and Lanai, Hawaii comprises critical breeding habitat for humpback whales (Megaptera novaeangliae) of the Central North Pacific stock. However, like many regions where marine mega-fauna gather, these waters are also the focus of a flourishing local eco-tourism and whale watching industry. Our aim was to establish current trends in habitat preference in female-calf humpback whale pairs within this region, focusing specifically on the busy, eastern portions of the channel. We used an equally-spaced zigzag transect survey design, compiled our results in a GIS model to identify spatial trends and calculated Neu's Indices to quantify levels of habitat use. Our study revealed that while mysticete female-calf pairs on breeding grounds typically favor shallow, inshore waters, female-calf pairs in the Au'au Channel avoided shallow waters (<20 m) and regions within 2 km of the shoreline. Preferred regions for female-calf pairs comprised water depths between 40–60 m, regions of rugged bottom topography and regions that lay between 4 and 6 km from a small boat harbor (Lahaina Harbor) that fell within the study area. In contrast to other humpback whale breeding grounds, there was only minimal evidence of typical patterns of stratification or segregation according to group composition. A review of habitat use by maternal females across Hawaiian waters indicates that maternal habitat choice varies between localities within the Hawaiian Islands, suggesting that maternal females alter their use of habitat according to locally varying pressures. This ability to respond to varying environments may be the key that allows wildlife species to persist in regions where human activity and critical habitat overlap
Effects of Different Selenium Levels on Gene Expression of a Subset of Selenoproteins and Antioxidative Capacity in Mice
Driven far astray A reading of ancient Greek thought
Available from British Library Document Supply Centre-DSC:DXN047840 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo
Spektroskopische Untersuchung statischer und dynamischer wechselwirkungsinduzierter Effekte durch ferninfrarote Absorption und depolarisierte Rayleigh-Streuung. Fluessige CS_2/C_6H_6-Mischungen
Available from TIB Hannover: DW 8338 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
Far-infrared interaction-induced absorption spectra of CS2C6H6 liquid mixtures
Far-infrared absorption spectra of liquid mixtures CS2C6H6 at three concentrations display excess values of the absorption and the effective dipole moment with respect to both components. These spectral features are interpreted in terms of the dynamics of the local environmental fluctuation. We believe that these interaction-induced spectra reflect the formation and the decay of transient clusters rather than binary complexes. © 1992
Stimulation of glucose transport in osteoblastic cells by parathyroid hormone and insulin-like growth factor I
Insulin and parathyroid hormone (PTH) regulate glucose metabolism in bone cells. In order to differentiate between the effects of these hormones and to compare the potency of insulin with that of insulin-like growth factor (IGF) I, we treated rat bone-derived osteoblastic (PyMS) cells for different time periods and at different concentrations with insulin, IGF I, or PTH, and measured [1-(14)C]-2-deoxy-D: -glucose (2DG) uptake and incorporation of D: -[U-(14)C] glucose into glycogen. 2DG uptake was Na-independent with an apparent affinity constant (K (M)) of ~2 mmol/l. Expression of the high affinity glucose transporters (GLUT), GLUT1 and GLUT3 but not of GLUT4, was found by Northern and Western analysis. Similar to the findings with primary rat osteoblasts, but distinct from those in rat fibroblasts, 2DG uptake and glycogen synthesis were increased in this cell line after exposure to low concentrations (0.1 nmol/l and above) of PTH. IGF I at low doses (0.3 nmol/l and above) or insulin at higher doses (1 nmol/l and above) stimulated 2DG uptake and [(3)H] thymidine incorporation into DNA. 2DG transport was enhanced already after 30 min of IGF I treatment whereas the effect of PTH became significant after 6 h. It is concluded that IGF I rather than insulin may be a physiological regulator of 2DG transport and glycogen synthesis in osteoblasts
An intriguing and facile one-pot catalytic synthesis of N-alkylated lactams
Catalyzed by Raney nickel, hydrogenation of 1,2-adamantane oxime esters or cyano esters afforded the unexpected N-alkylated lactams in good to moderate yields, probably proceeding through the so-called hydrogen autotransfer process. This reaction provided an efficient one-pot method for synthesis of N-alkylated lactams which had significant anti-influenza A activity. © 2012 Springer-Verlag Wien
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