PubMed · 13846753
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
A M ZADE-OPPEN. 1960. [Is hemolysis partial?].. https://pubmed.ncbi.nlm.nih.gov/13846753/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Transcription activator-like effectors (TALEs) in plant-pathogenic Xanthomonas bacteria activate expression of plant genes and support infection or cause a resistance response. PthA4AT is a TALE with a particularly short DNA-binding domain harboring only 7.5 repeats which triggers cell death in Nicotiana benthamiana; however, the genetic basis for this remains unknown. To identify possible target genes of PthA4AT that mediate cell death in N. benthamiana, we exploited the modularity of TALEs to stepwise enhance their specificity and reduce potential target sites. Substitutions of individual repeats suggested that PthA4AT-dependent cell death is sequence specific. Stepwise addition of repeats to the C-terminal or N-terminal end of the repeat region narrowed the sequence requirements in promoters of target genes. Transcriptome profiling and in silico target prediction allowed the isolation of two cell death inducer genes, which encode a patatin-like protein and a bifunctional monodehydroascorbate reductase/carbonic anhydrase protein. These two proteins are not linked to known TALE-dependent resistance genes. Our results show that the aberrant expression of different endogenous plant genes can cause a cell death reaction, which supports the hypothesis that TALE-dependent executor resistance genes can originate from various plant processes. Our strategy further demonstrates the use of TALEs to scan genomes for genes triggering cell death and other relevant phenotypes.
When the TCR is formed in the thymus, fragments of DNA are excised from the T cell progenitor chromosome. These TCR rearrangement excision circles (TRECs) are stable, are not replicated in cell division and are therefore most frequent in naive T cells that have recently left the thymus. During life, the average TREC content of peripheral naive T cells decreases between one and two orders of magnitude in humans. It is generally believed that the age-dependent decrease in the production of naive T cells by the thymus is sufficient to explain the decrease in the TREC content. Here, we demonstrate that this decrease in thymic production is required, but it is not sufficient to explain the TREC data. Only if the decrease in thymic output is compensated by homeostasis can one explain the decrease in the TREC content. The homeostatic response can take two forms: when the total number of naive T cells declines, there could be an increase in the renewal rate or an increase of the average cellular lifespan.
Treatment of Parkinson disease has improved dramatically over the past quarter of a century and promising therapies are emerging. Although treatment with levodopa results in marked symptomatic improvement, mortality rates of the disease have remained relatively unchanged. Recent findings of abnormal protein folding, coupled with oxidative stress, provide scientific rationale for novel therapeutic strategies designed to slow disease progression. To be effective, these disease-modifying and neuroprotective therapies must be instituted early in the course of the disease and early diagnosis therefore is critical. Consequently, primary care physicians will play an increasingly important role in early institution of such neuroprotective strategies. This review is designed to highlight some of the recent advances in our understanding of the mechanisms of neurodegeneration and to draw attention to the importance of early recognition and implementation of the new therapeutic interventions.