The effect of polyphenols in post stroke adults: A systematic review of randomised controlled trials

BACKGROUND

After a stroke, survivors are often left with significant disabilities and are at a greater risk of recurrent strokes. It is vital stroke survivors receive effective treatments to assist with rehabilitation and reduce risk factors for secondary stroke. Observational and preclinical studies have highlighted the promising role of polyphenols in these regards.

METHODS

A systematic review of original research which assessed the role of polyphenols on health outcomes in post stroke adults was conducted. PROQUEST, SCOPUS (Elsevier), MEDLINE (EBSCO), Embase and Cochrane Library databases were searched up to the 29th of October 2021.

RESULTS

A total of 9 studies met the full inclusion criteria and were included in this review. Several classes of polyphenols were assessed including hydroxybenzoic acids, stilbenes and flavonoids. Numerous health outcomes were assessed including vascular function, stroke disability, blood pressure, blood glucose and c-reactive protein. The majority of the studies included in this review (n = 8) note improvements in the polyphenol groups for at least one outcome measure. However, small sample sizes, short trial length and reporting bias prevent firm conclusions from being drawn.

CONCLUSION

This review provides promising preliminary evidence that polyphenols may be beneficial for post stroke adults, however, more research is required. To ensure reliable methodology and replication of results, future studies should include outcome statistics and effect sizes. Trials with a longer duration and large sample size should also be considered.

Analysis of meiosis in Pristionchus pacificus reveals plasticity in homolog pairing and synapsis in the nematode lineage

Meiosis is conserved across eukaryotes yet varies in the details of its execution. Here we describe a new comparative model system for molecular analysis of meiosis, the nematode Pristionchus pacificus, a distant relative of the widely studied model organism Caenorhabditis elegans. P. pacificus shares many anatomical and other features that facilitate analysis of meiosis in C. elegans. However, while C. elegans has lost the meiosis-specific recombinase Dmc1 and evolved a recombination-independent mechanism to synapse its chromosomes, P. pacificus expresses both DMC-1 and RAD-51. We find that SPO-11 and DMC-1 are required for stable homolog pairing, synapsis, and crossover formation, while RAD-51 is dispensable for these key meiotic processes. RAD-51 and DMC-1 localize sequentially to chromosomes during meiotic prophase and show nonoverlapping functions. We also present a new genetic map for P. pacificus that reveals a crossover landscape very similar to that of C. elegans, despite marked divergence in the regulation of synapsis and crossing-over between these lineages.

IRAK-dependent phosphorylation of Stat1 on serine 727 in response to interleukin-1 and effects on gene expression

Interleukin-1 (IL-1) induces the phosphorylation of Stat1 on serine 727 but not on tyrosine 701. Analyses of mutant I1A cells, which lack the IL-1 receptor-associated kinase (IRAK), and of I1A cells reconstituted with deletion mutants of IRAK show that the IL-1-mediated phosphorylation of Stat1 on serine requires the IRAK protein but not its kinase activity and does not involve phosphatidylinositol-3'-kinase (PI3K) or the mitogen-activated protein (MAP) kinases p38 or ERK. IRAK and Stat1 interact in vivo, and this interaction is increased in response to IL-1, suggesting that IRAK may serve to recruit the as yet unknown IL-1-induced Stat1 serine kinase. Chemical inhibitors or dominant-negative forms of signaling components required to activate NF-kappa B, ATF, or AP-1 in response to IL-1 do not affect the phosphorylation of Stat1 on serine. IL-1 and tumor necrosis factor (TNF) enhance the serine phosphorylation of Stat1 that occurs in response to interferon-gamma (IFN-gamma) and potentiate IFN-gamma-mediated, Stat1-driven gene expression, thus contributing to the synergistic activities of these proinflammatory cytokines.

Roles of phosphatidylinositol 3-kinase in interferon-gamma-dependent phosphorylation of STAT1 on serine 727 and activation of gene expression

STAT1 must be phosphorylated on serine 727 to be fully active in transcription. We show that phosphatidylinositol 3-kinase (PI3K) and its effector kinase Akt play an important role in the serine phosphorylation of STAT1 and in the activation of gene expression in response to interferon-gamma (IFN gamma). IFN gamma activates PI3K as well as Akt in a variety of cell lines. Specific inhibition of PI3K abrogates IFN gamma-induced, but not interleukin-1- or tumor necrosis factor-alpha-induced, phosphorylation of STAT1 on serine and reduces STAT1-dependent transcription and gene expression by approximately 7-fold. Constitutively active forms of PI3K or Akt activate and their dominant-negative derivatives inhibit STAT1-driven transactivation in response to IFN gamma. In addition to PI3K and Akt, JAK1, JAK2, and the tyrosine 440 STAT1 docking residue of IFNGR1 are required for STAT1 to be phosphorylated on serine. Taken together, these results suggest that the following events lead to the activation of STAT1 upon IFN gamma stimulation: 1) PI3K and Akt are activated by the occupied receptor and Tyr-440 is phosphorylated by the activated JAKs; 2) STAT1 docks to Tyr-440; and 3) Tyr-701 is phosphorylated by the JAKs and Ser-727 is phosphorylated by a kinase downstream of Akt.

[Standard versus decreasing weight loss. Better tolerance and comfort in hemodialysis]

The usual procedure to eliminate an overweight in hemodialysis consist in eliminating the whole amount of water distributed in an equitable way during the four hours hemodialysis session. This approach has tried to establish in what way the comfort of patients under dialysis improved, varying this loss in a decreasing way from the beginning to the end of the session.