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Different Time-points (different + time-point)
Selected AbstractsSubjective mental time: the functional architecture of projecting the self to past and futureEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 10 2009Shahar Arzy Abstract Human experience takes place in the line of mental time (MT) created through ,self-projection' of oneself to different time-points in the past or future. Here we manipulated self-projection in MT not only with respect to one's life events but also with respect to one's faces from different past and future time-points. Behavioural and event-related functional magnetic resonance imaging activity showed three independent effects characterized by (i) similarity between past recollection and future imagination, (ii) facilitation of judgements related to the future as compared with the past, and (iii) facilitation of judgements related to time-points distant from the present. These effects were found with respect to faces and events, and also suggest that brain mechanisms of MT are independent of whether actual life episodes have to be re-experienced or pre-experienced, recruiting a common cerebral network including the anteromedial temporal, posterior parietal, inferior frontal, temporo-parietal and insular cortices. These behavioural and neural data suggest that self-projection in time is a fundamental aspect of MT, relying on neural structures encoding memory, mental imagery and self. [source] Modulation of oat arginine decarboxylase gene expression and genome organization in transgenic Trypanosoma cruzi epimastigotesFEBS JOURNAL, Issue 3 2006María P. Serra We have previously demonstrated that wild-type Trypanosoma cruzi epimastigotes lack arginine decarboxylase (ADC) enzymatic activity as well as its encoding gene. A foreign ADC has recently been expressed in T. cruzi after transformation with a recombinant plasmid containing the complete coding region of the oat ADC gene. In the present study, upon modulation of exogenous ADC expression, we found that ADC activity was detected early after transfection; subsequently it decreased to negligible levels between 2 and 3 weeks after electroporation and was again detected ,,4 weeks after electroporation. After this period, the ADC activity increased markedly and became expressed permanently. These changes of enzymatic activity showed a close correlation with the corresponding levels of ADC transcripts. To investigate whether the genome organization of the transgenic T. cruzi underwent any modification related to the expression of the heterologous gene, we performed PCR amplification assays, restriction mapping and pulse-field gel electrophoresis with DNA samples or chromosomes obtained from parasites collected at different time-points after transfection. The results indicated that the transforming plasmid remained as free episomes during the transient expression of the foreign gene. Afterwards, the free plasmid disappeared almost completely for several weeks and, finally, when the expression of the ADC gene became stable, two or more copies of the transforming plasmid arranged in tandem were integrated into a parasite chromosome (1.4 Mbp) bearing a ribosomal RNA locus. The sensitivity of transcription to ,-amanitin strongly suggests involvement of the protozoan RNA polymerase I in the transcription of the exogenous ADC gene. [source] Increased expression of non-interleukin-2 T cell growth factors and their implications during liver allograft rejection in ratsJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 7 2007Wei-Lin Wang Abstract Background and Aim:, Rejection remains a problem in the transplantation field. The aim of this study was to establish acute and chronic rejection models in rats and to investigate the roles of non-interleukin (IL)-2 T cell growth factors such as IL-15, IL-7 and IL-13 during rejection. Methods:, A liver transplant model was established using Dark Agouti and Brown Norway rats. The rats were divided into group A, left without treatment; group B, received cyclosporinee (1 mg/kg/day); and group C, cyclosporinee (4 mg/kg/day). Histopathological, reverse transcriptase-polymerase chain reaction and western blot were performed in liver specimens obtained from different time-points after transplantation in the three groups. Results:, In group A, the livers showed irreversible acute cellular rejection with cell infiltration. In group B, chronic liver rejection was found, with graft infiltration, ductular damage or proliferation, obliterative arteriopathy and liver fibrosis. No apparent histological alterations were observed in group C. IL-15, IL-7 and IL-13 messenger RNA and their protein were all highly expressed in the liver specimens of groups A and B. Upregulated expression was found in IL-15 since the first day after transplantation and in IL-7 and IL-13 since day 6. The extent of IL-15 upregulation was more than that of IL-7 and IL-13. Conclusions:, Liver transplantation in Dark Agouti to Brown Norway rats with low-dose immunosuppression can induce chronic rejection. In the process of acute and chronic allograft rejections, non-IL-2 T cell growth factors such as IL-15, IL-7 and IL-13 play roles. Strategies should pay more attention to regulating these cytokines after liver transplantation. [source] Neutralizing antibody response variation against dengue 3 strainsJOURNAL OF MEDICAL VIROLOGY, Issue 10 2008Mayling Alvarez Abstract To evaluate the neutralizing antibody activity of a human sera panel against seven strains of the homotypic virus. Sera were collected from DENV-3 immune individuals. Two DENV-3 genotypes and strains isolated at different time-points during the 2000 and 2001,2002 Havana epidemics were included. A panel of 20 late convalescent sera collected 16,18 months after acute illness from DF and DHF patients are studied. These individuals were infected during the 2001,2002 Havana DENV-3 epidemic. All but four sera collected from DF cases had a secondary DENV-1/DENV-3 infection. Sera neutralizing antibody titer against the seven DENV-3 strains were determined by plaque reduction neutralization technique. Sera samples were tested simultaneously. Studied sera showed higher levels of neutralizing antibodies to DENV-3 strains of genotype III compared to genotype V. Interesting, higher levels of neutralizing antibodies were detected to DENV-3 strain isolated at the end of the epidemic 2001,2002. An increased tendency of GMT of neutralizing antibodies according to epidemic evolution was observed for the 2001,2002 outbreak. In general, antibody levels in sera collected from DF cases were higher. Differences in the neutralization capacity of immune DENV-3 sera tested against two homologous genotypes including strains of the same genotype are demonstrated. Observed results suggest that virus changed in the course of the epidemic. The implications of this finding in terms of dengue pathogenesis and vaccine development need to be considered. J. Med. Virol. 80:1783,1789, 2008. © 2008 Wiley-Liss, Inc. [source] Changes of elbow kinematics and kinetics during 1 year after strokeMUSCLE AND NERVE, Issue 3 2008Mehdi M. Mirbagheri PhD Abstract A precise description of the natural history of motor recovery after stroke provides a framework for understanding the mechanisms underlying this improvement and for tracking the efficacy of rehabilitation treatments. To characterize the time course of this change in motor impairment, we examined voluntary elbow movements in hemiparetic stroke survivors over a period of 1 year after stroke. Based on the possibility that both central nervous system and muscle factors could contribute to the observed clinical state, we hypothesized that we should observe at least two major recovery patterns of motor impairment. To explore these predictions, we assessed elbow movement range, movement speed, and isometric force generation. Subjects were examined five times over the 12-month period. We used the "growth mixture" model to characterize recovery of these measures, and the Fugl-Meyer scale (FMS) of upper-extremity function at 1 month to predict the recovery. We observed two distinct recovery classes. Class 1 started with low values for the physiological measures, and these increased over time, whereas class 2 tended to start with higher values and showed widely divergent recovery patterns. Using the logistic regression model, the impact of FMS on class membership was estimated for each parameter. Based on these data, we were able to accurately predict arm impairment recovery at different time-points in the first year, information of great potential value for planning targeted therapeutic interventions. Muscle Nerve, 2008 [source] Systemic tetracycline delays degradation of three different collagen membranes in rat calvariaCLINICAL ORAL IMPLANTS RESEARCH, Issue 2 2009Ofer Moses Abstract Objectives: The aim of this study was to quantitatively evaluate the effect of systemic tetracycline (TTC) on the degradation of three different collagen membranes. Materials and methods: Collagen membranes were cut into 5 mm diameter membrane discs and labeled with aminohexanoyl-biotin- N -hydroxy-succinimide ester. One membrane disc each of a non-cross-linked [BioGide® (BG)], glutaraldehyde cross-linked [BioMend Extend® (BM)], and ribose cross-linked [OssixÔ (OS)] was implanted on the calvaria of 40 Wistar rats. Another 10 biotinylated collagen membrane discs from each membrane type were processed for histologic observation and served as baseline; half of them (five from each group) were also treated with formic acid to inspect possible interference with biotinilazation of collagen by formic acid used during the decalcification process. A 10 mg/kg dose of TTC (50% of the minimal recommended antibacterial dose) to the experimental (20 animals) and saline to the control (20 animals) group was administered intramuscularly every 3 days. From each group, block sections were retrieved in half of the animals after 14 days and in the remaining after 28 days. Decalcified tissue histology was stained with streptavidin horseradish peroxidase. A computer-assisted program measured the membranes' collagen contents. Statistical analysis consisted of analysis of variance (ANOVA) with repeated measures. Results: No statistically significant differences in collagen contents were appreciated between biotinylated non-implanted membranes treated or not treated by formic acid. Systemic TTC had a different effect on the bio-degradation of the membranes: while it significantly decreased the resorption of two of the membranes (BG and BM), it had minimal influence on the ribose cross-linked membrane (OS). ANOVA with repeated measures, tests of within-subjects effects, showed a statistically significant difference between the membranes (P<0.001), within the membranes at the different time-points (P<0.001), a significant interaction between membranes and time and between the membranes and administered TTC (P<0.001). Test of between-subject effects revealed a statistically significant interaction with time and with TTC (P<0.001). Conclusions: Systemically administered TTC in sub-antibacterial doses may offer a possible treatment alternative to reduce bio-degradation and enhance bio-durability of certain collagen membranes. The findings of the present study could have clinical application in large non-self-contained bone defects, where prolonged membrane barrier functions are desirable. [source] | |||||||||||||