Characterization and Expression of Glutamate Dehydrogenase in Response to Acute Salinity Stress in the Chinese Mitten Crab, Eriocheir sinensis

Glutamate dehydrogenase (GDH) is a key enzyme for the synthesis and catabolism of glutamic acid, proline and alanine, which are important osmolytes in aquatic animals. However, the response of GDH gene expression to salinity alterations has not yet been determined in macro-crustacean species.GDH cDNA was isolated from Eriocheir sinensis. Then, GDH gene expression was analyzed in different tissues from normal crabs and the muscle of crabs following transfer from freshwater (control) directly to water with salinities of 16‰ and 30‰, respectively. Full-length GDH cDNA is 2,349 bp, consisting of a 76 bp 5'- untranslated region, a 1,695 bp open reading frame encoding 564 amino acids and a 578 bp 3'- untranslated region. E. sinensis GDH showed 64-90% identity with protein sequences of mammalian and crustacean species. Muscle was the dominant expression source among all tissues tested. Compared with the control, GDH expression significantly increased at 6 h in crabs transferred to 16‰ and 30‰ salinity, and GDH expression peaked at 48 h and 12 h, respectively, with levels approximately 7.9 and 8.5 fold higher than the control. The free amino acid (FAA) changes in muscle, under acute salinity stress (16‰ and 30‰ salinities), correlated with GDH expression levels. Total FAA content in the muscle, which was based on specific changes in arginine, proline, glycine, alanine, taurine, serine and glutamic acid, tended to increase in crabs following transfer to salt water. Among these, arginine, proline and alanine increased significantly during salinity acclimation and accounted for the highest proportion of total FAA.E. sinensis GDH is a conserved protein that serves important functions in controlling osmoregulation. We observed that higher GDH expression after ambient salinity increase led to higher FAA metabolism, especially the synthesis of glutamic acid, which increased the synthesis of proline and alanine to meet the demand of osmoregulation at hyperosmotic conditions

Long-term Spectroscopic Variability of Two Oe Stars

HD 45314 and HD 60848 are poorly studied Oe-type stars. Spectroscopic monitoring over 5 years reveals strong variations in the strength of the emission lines and for HD 45314 in the V/R ratio of the double-peaked emissions. Part of these long-term variations could be recurrent.status: publishe

Early bifrontal brain injury: sequential neuropsychological developmental features

peer reviewe

Increased productivity of recombinant tissular plasminogen activator (t-PA) by butyrate and shift of temperature: a cell cycle phases analysis.

Directed control of cell metabolism by a modification of the physicochemical conditions (presence of Na-butyrate and modification of the temperature) was used to modulate the productivity of human recombinant tissular plasminogen activator (t-PA) expressed under control of SV40 promoter in Chinese Hamster Ovary (CHO) cell lines. We showed that both by adding Na-butyrate or lowering temperature from 37 degrees C to 32 degrees C there is an increase in the amount of t-PA excreted, while cell growth is significantly reduced. The treatments also increased the intracellular amount of t-PA. We measured the distribution of cell cycle phases by cytometry and used a modification of the equations of Kromenaker and Srienc (1991, 1994 a, b) to analyse the intracellular t-PA production rate in the different cell cycle phases. Intracellular t-PA was shown to accumulate in G1 phase in all conditions (at 37 degrees C, at 32 degrees C and in presence of butyrate). Moreover, we have shown that the distribution of the time cells treated by butyrate are maintained in the G1cell cycle phase is significantly increased. t-PA produced in the different cell culture conditions tested was analysed by zymogram and western blotting: neither butyrate, neither the shift of temperature changed significantly the overall quality of the protein. The N-glycan patterns of recombinant human t-PA was also analysed with carbohydrate-specific lectins. Butyrate caused a transitory increase in N-linked complex high-mannose oligosaccharides without any effect on the sialic acid content of t-PA.Journal ArticleSCOPUS: cp.jinfo:eu-repo/semantics/publishe

Cerebral metabolic correlates of four dementia scales in Alzheimer's disease

© 2005 Springer Medizin Verlag Gmb

Cerebral metabolic correlates of four dementia scales in Alzheimer's disease

Different scales can be used to evaluate dementia severity in Alzheimers disease (AD). They do assess different cognitive or functional abilities, but their global scores are frequently in mutual correlation. Functional imaging provides an objective method for the staging of dementia severity. Positron emission tomography was used to assess the relationship between brain metabolism and four dementia scales that reflect a patients global cognitive abilities (mini mental state), caregivers evaluation of cognitive impairment (newly designed scale), daily living functioning (instrumental activities of daily living) and global dementia (clinical dementia rating). We wondered whether different clinical dementia scales would be related to severity of metabolic impairment in the same brain regions, and might reflect impairment of common cognitive processes. 225 patients with probable AD were recruited in a prospective multicentre European study. All clinical scales were related to brain metabolism in associative temporal, parietal or frontal areas. A factorial analysis demonstrated that all scales could be classified in a single factor. That factor was highly correlated to decrease of cerebral activity in bilateral parietal and temporal cortices, precuneus, and left middle frontal gyrus. This finding suggests that global scores for all scales provided similar information on the neural substrate of dementia severity. Capitalizing on the neuroimaging literature, dementia severity reflected by reduced metabolism in posterior and frontal associative areas in AD might be related to a decrease of controlled processes