Factors contributing to cognitive deficits in elderly residents of rural areas.

OBJECTIVE: Due to the growing aging of societies an increasingly large group of people suffers from age-related impairment of cognitive functions and thus reducing the quality of life of the elderly. The purpose of the study was to evaluate the efficiency of cognitive functions in a group of aging residents of rural areas. PATIENTS AND METHODS: The inhabitants of a rural area were recruited and assessed: cognitive function as well as intellectual and physical activity, number of years of education, presence of diseases, using stimulants, diet, sources of living, marital status and family situation Subjects were divided into two groups: persons above 65 and older, constituting the studied group and persons between 40 and 64 years of age, constituting the control group. Both groups did not significantly differ in terms of sex or years of education. RESULTS: Statistically significant differences (p < 0.05) were found in the results of the tests concerning such functions as the sight recognition memory and spatial recognition memory, spatial operating memory both on the strategy level and on the level of committed errors. An analysis of the results obtained in the group of elderly people did not indicate any major differences between men and women as regards the analyzed cognitive functions, no statistically significant differences were found in cognitive testing depending on the number of years of education. The studied persons included in the physically active group scored better in the visual memory and learning tests. CONCLUSIONS: The conducted studies elucidated the dependence of the level of cognitive functions on age, a positive impact of physical activity on some cognitive functions, however we could not find differences between the efficiency of those functions and education, sex, presence of somatic diseases and activity of persons aged > 65.

Donor-specific regulatory T cells generated on donor B cells are superior to CD4+CD25high cells in controlling alloimmune responses in humanized mice.

CD4(+)CD25highFOXP3(+) regulatory T cells (Tregs) can control allospecific immune responses in vitro and in titrated lymphopenic transplantation models. However, under non-lymphopenic conditions, as seen in patients with autoimmune diseases or after organ transplantation, polyspecific Tregs so far have been largely ineffective to control immune responses in animal models. Yet currently polyspecific CD4(+)CD25high Tregs are being tested in clinical trials. Donor materials are usually limited for the generation of donor-specific Tregs. Herein we have developed a method to produce large quantities of activated donor B cells by stimulation of donor peripheral blood mononuclear cells with 3T3 fibroblasts expressing CD40L. These activated donor B cells are potent stimulators of CD4(+)CD25high Tregs, which were expanded efficiently to inhibit an allo-MLR in donor-specific fashion. They were far more potent in inhibiting alloimmune responses in humanized mice compared with the polyspecific CD4(+)CD25high Tregs. Generation of donor-specific Tregs could be performed under good manufacturing practice conditions. Donor-reactive Tregs may be a valuable tool to control immune responses after transplantation a setting in which polyspecific Tregs have failed to date.

Cognitive reappraisal modulates performance following negative feedback in patients with major depressive disorder.

BACKGROUND: Depressed patients show impaired performance following negative feedback; the probability of committing an error is increased immediately after an error. This deficit is assumed to be highly specific and to represent a trait marker of major depressive disorder (MDD). Inconsistencies in currently available data could reflect inter-individually different strategies to regulate negative affect. The present study examined modulation of performance following negative feedback by cognitive reappraisal to regulate aversive affect in depressed patients. METHOD: Thirty-three depressed patients and 33 control subjects performed tasks of varying difficulty over a prolonged time. Emotional feedback was given immediately after each trial. Performance was further analysed within subgroups using cognitive reappraisal of aversive events with high and low frequency. RESULTS: A significant group by task difficulty interaction for absolute number of subsequent errors revealed that depressed patients were especially impaired when receiving negative feedback more frequently. An increased probability of subsequent errors was shown in patients irrespective of task difficulty. Analysis of subgroups revealed higher absolute number and probability of subsequent errors only in depressed patients habitually not using cognitive reappraisal to regulate aversive emotions. Depressed patients using this strategy did not differ from controls. CONCLUSIONS: The present results replicate the observation of impaired performance in depressed patients following failure feedback. Most importantly, a subgroup of patients who habitually rely on cognitive reappraisal of aversion-eliciting events, such as negative performance feedback, was not impaired. This modulatory influence of emotion regulation strategies on performance subsequent to negative feedback suggests that training emotion regulation in achievement situations should be incorporated in current concepts to prevent relapse.

Exploring the sequence space for tetracycline-dependent transcriptional activators: novel mutations yield expanded range and sensitivity.

Regulatory elements that control tetracycline resistance in Escherichia coli were previously converted into highly specific transcription regulation systems that function in a wide variety of eukaryotic cells. One tetracycline repressor (TetR) mutant gave rise to rtTA, a tetracycline-controlled transactivator that requires doxycycline (Dox) for binding to tet operators and thus for the activation of P(tet) promoters. Despite the intriguing properties of rtTA, its use was limited, particularly in transgenic animals, because of its relatively inefficient inducibility by doxycycline in some organs, its instability, and its residual affinity to tetO in absence of Dox, leading to elevated background activities of the target promoter. To remove these limitations, we have mutagenized tTA DNA and selected in Saccharomyces cerevisiae for rtTA mutants with reduced basal activity and increased Dox sensitivity. Five new rtTAs were identified, of which two have greatly improved properties. The most promising new transactivator, rtTA2(S)-M2, functions at a 10-fold lower Dox concentration than rtTA, is more stable in eukaryotic cells, and causes no background expression in the absence of Dox. The coding sequences of the new reverse TetR mutants fused to minimal activation domains were optimized for expression in human cells and synthesized. The resulting transactivators allow stringent regulation of target genes over a range of 4 to 5 orders of magnitude in stably transfected HeLa cells. These rtTA versions combine tightness of expression control with a broad regulatory range, as previously shown for the widely applied tTA.

Generation of conditional mutants in higher eukaryotes by switching between the expression of two genes.

A regulatory system for the in-depth study of gene functions in higher eukaryotic cells has been developed. It is based on the tetracycline-controlled transactivators and reverse tTA, which were remodeled to discriminate efficiently between two different promoters. The system permits one to control reversibly the activity of two genes, or two alleles of a gene, in a mutually exclusive way, and also allows one to abrogate the activities of both. This dual regulatory circuit, which can be operated by a single effector substance such as doxycycline, overcomes limitations of conventional genetic approaches. The conditional mutants that can now be generated will be useful for the study of gene function in vitro and in vivo. In addition, the system may be of value for a variety of practical applications, including gene therapy.

Tetracycline-controlled transcription in eukaryotes: novel transactivators with graded transactivation potential.

Several tetracycline-controlled transactivators (tTA) were generated which differ in their activation potential by >3 orders of magnitude. The transactivators are fusions between the Tet repressor and minimal transcriptional activation domains derived from Herpes simplex virus protein 16 (VP16). By reducing the VP16 moiety of the previously described tTA to 12 amino acids, potential targets for interactions with various cellular transcription factors were eliminated, as were potential epitopes which may elicit a cellular immune response. When compared with the originally described tTA, these new transactivators are tolerated at higher intracellular concentrations. This will facilitate establishment of tet regulatory systems under a variety of conditions, but particularly when cell type-restricted tetracycline-controlled gene expression is to be achieved in transgenic organisms via homologous recombination.

cDNA cloning of the constant region genes of the guinea pig alpha/beta T-cell receptor.

A lambda gt11 cDNA library was prepared from activated guinea pig T-lymphocyte blasts. cDNA clones coding for the alpha-chain and beta-chain of the constant region of the guinea pig T-cell receptor were isolated by means of crosshybridization using the corresponding mouse cDNA genes. The guinea pig and the corresponding mouse cDNA genes hybridized in Northern blots with mouse mRNA of the same size. Guinea pig T-cell receptor mRNA showed the same size like its mouse counterpart. In contrast to the alpha-chain clone, genomic Southern blot analysis showed that the identified beta-chain gene fragment undergoes genomic rearrangement during T-cell differentiation.