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121.
The identification of genes mediating susceptibility to type 1 diabetes (T1D) remains a challenging task. Using a positional
cloning approach based on the analysis of nonobese diabetic (NOD) mice congenic over the Idd6 diabetes susceptibility region, we found that the NOD allele at this locus mediates lower mRNA expression levels of the lymphoid
restricted membrane protein gene (Lrmp/Jaw1). Analysis of thymic populations indicates that Lrmp is expressed mainly in immature thymocytes. The Lrmp gene encodes a type 1 transmembrane protein that localizes to the ER membrane and has homology to the inositol 1,4,5-triphosphate
receptor-associated cGMP kinase substrate gene, which negatively regulates intracellular calcium levels. We hypothesize that
the observed decrease in expression of the Lrmp gene in NOD mice may constitute a T1D susceptibility factor in the Idd6 region. 相似文献
122.
Mesembryanthemum crystallinum L. (Aizoaceae) is a facultative annual halophyte and a C(3)-photosynthesis/crassulacean acid metabolism intermediate species currently used as a model plant in stress physiology. Both salinity and high light irradiance stress are known to induce CAM in this species. The present study was performed to provide a diagnosis of alterations at the photosystem II level during salinity and irradiance stress. Plants were subjected for up to 13 days to either 0.4M NaCl salinity or high irradiance of 1000 micromol m(-2)s(-1), as well as to both stress factors combined (LLSA=low light plus salt; HLCO=high light of 1000 micromol m(-2)s(-1), no salt; HLSA=high light plus salt). A control of LLCO=low light of 200 micromol m(-2)s(-1), no salt was used. Parameters of chlorophyll a fluorescence of photosystem II (PSII) were measured with a pulse amplitude modulated fluorometer. HLCO and LLSA conditions induced a weak degree of CAM with day/night changes of malate levels (Deltamalate) of approximately 12mM in the course of the experiment, while HLSA induced stronger CAM of Deltamalate approximately 20 mM. Effective quantum yield of PSII, DeltaF/F'(m), was only slightly affected by LLSA, somewhat reduced during the course of the experiment by HLCO and clearly reduced by HLSA. Potential quantum efficiency of PSII, F(v)/F(m), at predawn times was not affected by any of the conditions, always remaining at 0.8, showing that there was no acute photoinhibition. During the course of the days HL alone (HLCO) also did not elicit photoinhibition; salt alone (LLSA) caused acute photoinhibition which was amplified by the combination of the two stresses (HLSA). Non-photochemical, NPQ, quenching remained low (<0.5) under LLCO, LLSA and HLCO and increased during the course of the experiment under HLSA to 1-2. Maximum apparent photosynthetic electron transport rates, ETR(max), declined during the daily courses and were reduced by LLSA and to a similar extent by HLSA. It is concluded that M. crystallinum expresses effective stress tolerance mechanisms but photosynthetic capacity is reduced by the synergistic effects of salinity and light irradiance stress combined. 相似文献
123.
Rosmaninho-Salgado J Araújo IM Alvaro AR Duarte EP Cavadas C 《Journal of neurochemistry》2007,103(3):896-903
The adrenal chromaffin cells synthesize and release catecholamine (mostly epinephrine and norepinephrine) and different peptides, such as the neuropeptide Y (NPY). NPY stimulates catecholamine release through NPY Y1 receptor in mouse chromaffin cells. The aim of our study was to determine the intracellular signaling events coupled to NPY Y1 receptor activation that lead to stimulation of catecholamine release from mouse chromaffin cells. The stimulatory effect of NPY mediated by NPY Y1 receptor activation was lost in the absence of extracellular Ca2+. On the other hand, inhibition of nitric oxide synthase and guanylyl cyclase also decreased the stimulatory effect of NPY. Moreover, catecholamine release stimulated by NPY or by the nitric oxide donor (NOC-18) was inhibited by mitogen-activated protein kinase (MAPK) and protein kinase C inhibitors. In summary, in mouse chromaffin cells, NPY evokes catecholamine release by the activation the NPY Y1 receptor, in a Ca2+-dependent manner, by activating mitogen-activated protein kinase and promoting nitric oxide production, which in turn regulates protein kinase C and guanylyl cyclase activation. 相似文献
124.
Lula I Denadai AL Resende JM de Sousa FB de Lima GF Pilo-Veloso D Heine T Duarte HA Santos RA Sinisterra RD 《Peptides》2007,28(11):2199-2210
We report the complete sequence-specific hydrogen NMR assignments of vasoactive peptide angiotensin-(1-7) (Ang-(1-7)). Assignments of the majority of the resonances were accomplished by COSY, TOCSY, and ROESY peak coordinates at 400MHz and 600MHz. Long-side-chain amino acid spin system identification was facilitated by long-range coherence transfer experiments (TOCSY). Problems with overlapped resonance signals were solved by analysis of heteronuclear 2D experiments (HSQC and HMBC). Nuclear Overhauser effects (NOE) results were used to probe peptide conformation. We show that the inclusion of the angiotensin-(1-7) tyrosine residue is favored in inclusion complexes with beta-cyclodextrin. QM/MM simulations at the DFTB/UFF level confirm the experimental NMR findings and provide detailed structural information on these compounds in aqueous solution. 相似文献
125.
Ana Carolina Luchiari Cristiane Regina do Amaral Duarte Fúlvio Aurélio de Morais Freire Kari Nissinen 《Journal of Ethology》2007,25(2):169-175
We studied the colour preference of isolated Nile tilapia (Oreochromis niloticus) and whether previous residence or body size can affect environmental colour choice. In the first phase, a cylindrical tank
was divided into five differently coloured compartments (yellow, blue, green, white and red), a single fish was introduced
into the tank and the frequency at which this fish visited each compartment was recorded over a 2-day study period. An increasingly
larger fish (approx +2 cm in length each time) was then added into the tank on each of days 3, 5 and 7 (=four fish in the
tank by day 7), and the frequency at which each fish visited the different compartments of the tank was observed twice a day
to obtain visit frequency data on the differently sized fishes. This experiment was replicated six times. In the first phase,
the solitary fish established residence inside the yellow compartment on the first and second days. Following the
introduction of a larger fish, the smaller fish was displaced from the occupied compartment. Nile tilapia possibly shows this
preference for yellow as a function of its visual spectral sensitivity and/or the spectral characteristics of its natural
environment. Moreover, body size is an important factor in determining hierarchical dominance and territorial defence, and
dominant fish chose the preferred environmental colour compartment as their territory. 相似文献
126.
Several species of bivalves coexist at the lower intertidal of large tidal flats located in the enclosed or inland coast of
the northern area of the Nord-Patagonic archipelagos on the Chilean coast (ca. 40–42°S): Tagelus dombeii (Lamarck), Mulinia edulis (King & Broderip), Venus antiqua King & Broderip, Semele solida (Gray), Gari solida (Gray) and Diplodonta insconspicua Philippi. To explore possible spatial variation in the community structure of the macroinfauna inhabiting sediments with
different assemblages of these bivalves, seasonal sampling was carried out during 2003–2004 at two tidal flats of that area.
Higher species richness and specimen densities of the macroinfauna occurred in sediments with the higher densities of bivalves,
especially in sediments where the deep burrower T. dombeii reaches its greatest abundances. Our results suggest that, apart from presence of bivalves, the burrowing depth of these
organisms is also important in promoting the abundance of macroinfauna. Our results are in contrast with earlier conceptualizations
for community organization of the soft bottom macroinfauna inhabiting intertidal flats, related to biological interactions
occurring among different phyletic groups, such as that arguing that suspension feeding bivalves (such as T. dombeii and V. antiqua) will negatively affect the recruitment of species with planktonic larvae, by filtering them before they become established
in the substrate. Thus, it is concluded that beneficial effects of bivalve bioturbation overcome that negative effects on
the macroinfauna, although detrimental effects may well occur at bivalve densities higher than those studied here.
Electronic supplementary material Supplementary material is available for this article at and accessible for authorised users 相似文献
127.
Duarte CD Tributino JL Lacerda DI Martins MV Alexandre-Moreira MS Dutra F Bechara EJ De-Paula FS Goulart MO Ferreira J Calixto JB Nunes MP Bertho AL Miranda AL Barreiro EJ Fraga CA 《Bioorganic & medicinal chemistry》2007,15(6):2421-2433
We describe herein the discovery of LASSBio-881 (3c) as a novel in vivo antinociceptive, anti-inflammatory, and in vitro antiproliferative and antioxidant compound, with a cannabinoid ligand profile. We observed that LASSBio-881 (3c) was able to bind to CB1 receptors (71% at 100microM) and also to inhibit T-cell proliferation (66% at 10microM) probably by binding to CB2 receptors, in a non-proapoptotic manner, different from anandamide (1). It was also demonstrated that LASSBio-881 (3c) had an important antioxidant profile toward free radicals (DPPH and hydroxyl), probably due to its particular redox behavior, which reflects the presence of both nitro and 3,5-di-tert-butyl-4-hydroxyphenyl sub-units, as demonstrated by cyclic voltammetry studies. In addition, we showed that these structural sub-units are essential for the observed pharmacological activity. 相似文献
128.
Duarte FS Codeço Martins PR Romeiro GA Monteiro De Lima TC 《Bioorganic & medicinal chemistry》2007,15(4):1645-1650
This study investigated the antidepressant-like effect of 4-amine derivatives of 10,11-dihydro-5H-dibenzo-alkylamine-cycloheptane, 4-amine (3-N,N-dimethylpropylamine)-10,11-dihydro-5H-dibenzo[a,d]cycloheptane-5-one (ADDCH1) and 1,2,3,4,8,9-hexahydro-dibenzocyclohepta[4,4a,5-ef]1,4-diazepin (ADDCH2), in a validated experimental model of depression, the forced swimming test (FST) in mice. Female adult mice were sub-chronically (three doses in 24 h) or repeatedly (once a day for 10 days) treated with either of the compounds and evaluated in the FST. The sub-chronic treatment promoted a dose-dependent reduction in the immobility time in the FST with the doses of 50 mg/kg (ADDCH1) and 30 mg/kg (ADDCH2) ip being the most effective (33% and 37% of reduction, respectively). A similar profile of action was observed in the animals repeatedly treated with ADDCH1 50 mg/kg or ADDCH2 30 mg/kg ip (for 10 days) and there was no sign of motor impairment or locomotor activation as evaluated in the rota-rod and open-field tests, respectively. These findings suggest that these amine derivatives of the system dibenzocycloheptane have an antidepressant-like action which could be of clinical interest and, therefore, deserves further investigation. In addition, putative underlying mechanisms of action are discussed. 相似文献
129.
The pulping of Cynara cardunculus L. (cardoon) was performed under conditions for kraft, kraft-AQ and soda-AQ processes. The best results in terms of delignification degree, expressed as kappa number, pulp viscosity and screened yield, were obtained for the kraft-AQ process with 0.20% of anthraquinone (AQ). The papermaking potential of the selected pulp was studied attending to biometric fibre characterisation, refining aptitude, optical and strength properties. All properties were compared against a Eucalyptus globulus pulp at different refining degrees. The cardoon pulp was also evaluated concerning its potential to board manufacture, alone and in mixtures with pine pulp, giving rise to promising results for liner manufacture. 相似文献
130.
The impact of polyadenylation signals on plasmid nuclease-resistance and transgene expression 总被引:1,自引:0,他引:1
BACKGROUND: Efficient delivery and expression of plasmids (pDNA) is a major concern in gene therapy and DNA vaccination using non-viral vectors. Besides the use of adjuvants, the pDNA vector itself can be designed to maximize survival in nuclease-rich environments. Homopurine-rich tracts in polyadenylation sequences have been previously shown to be especially important in pDNA resistance. METHODOLOGY: The effect of modifications in the poly A sequence of a model pDNA vector (pVAX1GFP) on nuclease resistance and transgene expression was investigated. Four poly A sequences were studied: bovine growth hormone (BGH), mutant BGH, SV40 and a synthetic poly A. Plasmid resistance (half-life) was assessed through in vitro incubations with mammalian nucleases. The impact in transgene expression was studied by quantifying pDNA, mRNA, and GFP expression in CHO, hybridoma and HeLa cells. RESULTS AND CONCLUSIONS: In vitro and cell culture studies indicate that plasmids containing the SV40 and the synthetic poly A sequences present significant improvements in nuclease resistance (up to two-fold increase in half-life). However, RT-PCR analysis demonstrated that significant reduction in mRNA steady-state levels were responsible for a decrease in transgene expression and detected transfection level of CHO and hybridoma cells when using the more resistant plasmids. Interestingly, transfection of HeLa cells demonstrated that both poly A efficiency and plasmid resistance interfere significantly in transgene expression. The results strongly suggest that the choice of the poly A is important, not only for mRNA maturation/stability, but also for pDNA resistance, and should thus be taken into consideration in the design and evaluation of pDNA vectors. 相似文献