Iron supplementation for patients undergoing cardiac surgery: a systematic review and meta-analysis of randomized controlled trials.

PURPOSE: Iron supplementation has been evaluated in several randomized controlled trials (RCTs) for its potential to increase baseline hemoglobin and decrease red blood cell transfusion during cardiac surgery. This study's main objective was to evaluate the current evidence for iron administration in cardiac surgery patients. METHODS: We searched MEDLINE, EMBASE, CENTRAL, Web of Science databases, and Google Scholar from inception to 19 November 2020 for RCTs evaluating perioperative iron administration in adult patients undergoing cardiac surgery. The RCTs were assessed using a risk of bias assessment and the quality of evidence was assessed using the grading of recommendations, assessments, development, and evaluations. RESULTS: We reviewed 1,767 citations, and five studies (n = 554) met the inclusion criteria. The use of iron showed no statistical difference in incidence of transfusion (risk ratio, 0.86; 95% confidence interval, 0.65 to 1.13). Trial sequential analysis suggested an optimal information size of 1,132 participants, which the accrued information size did not reach. CONCLUSION: The current literature does not support or refute the routine use of iron therapy in cardiac surgery patients. TRIAL REGISTRATION: PROSPERO (CRD42020161927); registered 19 December 2019.

RéSUMé: OBJECTIF: La supplémentation en fer a été évaluée dans plusieurs études randomisées contrôlées (ERC) pour son potentiel à augmenter l'hémoglobine de base et à diminuer la transfusion d'érythrocytes pendant la chirurgie cardiaque. L'objectif principal de cette étude était d'évaluer les données probantes actuelles soutenant l'administration de fer chez les patients de chirurgie cardiaque. MéTHODE: Nous avons effectué des recherches dans les bases de données MEDLINE, EMBASE, CENTRAL, Web of Science et Google Scholar de leur création jusqu'au 19 novembre 2020 pour en extraire les ERC évaluant l'administration périopératoire de fer chez les patients adultes bénéficiant d'une chirurgie cardiaque. Les ERC ont été évaluées à l'aide d'une évaluation du risque de biais et la qualité des données probantes a été évaluée à l'aide du système de notation GRADE. RéSULTATS: Nous avons examiné 1767 citations et cinq études (n = 554) répondaient aux critères d'inclusion. L'administration de fer n'a montré aucune différence statistique dans l'incidence des transfusions (risque relatif, 0,86; intervalle de confiance à 95 %, 0,65 à 1,13). Selon l'analyse séquentielle des études, la taille d'information optimale serait de 1132 participants, une taille que l'information accumulée n'a pas atteint. CONCLUSION: La littérature actuelle ne soutient ni ne réfute l'utilisation systématique d'une thérapie à base de fer chez les patients de chirurgie cardiaque. ENREGISTREMENT DE L'éTUDE: PROSPERO (CRD42020161927); enregistrée le 19 décembre 2019.

Iron supplementation for patients undergoing cardiac surgery: a protocol for a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Iron administration has been evaluated in several randomized controlled trials for the potential of increasing baseline hemoglobin values and decreasing the incidence of red blood cell transfusion during cardiac surgery. We describe the protocol for a study aiming to evaluate the efficacy and safety of perioperative iron administration in patients undergoing cardiac surgery. METHODS: We will search MEDLINE, Embase, the Cochrane Central Register of Controlled Trials and the Web of Science, from inception to Nov. 19, 2020, for randomized controlled trials in any language evaluating the perioperative administration of iron in adult patients undergoing cardiac surgery; we will also include the first 50 results from Google Scholar. The primary outcome will be the incidence of red blood cell transfusion from the study intervention time until 8 weeks postoperatively. The secondary outcomes will be the number of red blood cell units transfused; change in ferritin level, reticulocyte count and hemoglobin concentration after iron administration; and adverse events. We will assess the risk of bias with the Cochrane Collaboration Risk of Bias Tool, and will analyze the primary and secondary outcomes using a random-effects model. INTERPRETATION: This study will summarize the current evidence about perioperative iron administration in patients undergoing cardiac surgery, help determine whether this intervention should be included in enhanced-recovery protocols, and shape future research if needed. The final manuscript will be submitted to a peer-reviewed journal. TRIAL REGISTRATION: PROSPERO no. CRD42020161927.

Metabolomic analysis of date palm seedlings exposed to salinity and silicon treatments.

Silicon is known to promote plant growth as well as stress tolerance of plants. The current study was undertaken to assess the growth promoting effect of silicon on date palm seedling development as well as its ability to abate some of the negative effects of salinity. In this study, date palm seedlings were treated with silicon and sodium chloride salts, and the effect of these salts on some physiological parameters of the plants was determined. In addition, a global nontargeted metabolomics analysis was performed for the leaf and root tissues using liquid chromatography-mass spectrometry (LC-MS). The results showed that under non-stress conditions, silicon treatment enhanced the growth of the date palm seedlings, however, under salinity, silicon slightly mitigates the negative effects of salt stress on the date palm seedlings although it enhances the potassium accumulation under this condition. The global metabolomics analysis has identified a total of 1,101 significant differentially accumulated (p, q ≤ 0.05) metabolites in leaves and roots under silicon, salinity or their combination. A differential pairwise metabolic profile comparison revealed the accumulation of distinct metabolites in response to silicon and salinity treatments such as antioxidant compounds pyridoxine, cepharanthine, allithiamine, myristic acid and boldine; osmoregulators such as mucic acid; along with the accumulation of detoxification intermediates such as S-D-lactoylglutathione, beta-cyano-L-alanine and gamma-glutamyl-conjugates. In addition, histochemical analyses revealed that application of silicon significantly (p ≤ 0.05) enhanced the formation of the Casparian strip. Identification of the differentially accumulated metabolites could offer an insight into how silicon is able to promote growth and salinity tolerance in date palms.

Overexpression of a Metallothionein 2A Gene from Date Palm Confers Abiotic Stress Tolerance to Yeast and Arabidopsis thaliana.

Although the date palm tree is an extremophile with tolerance to drought and certain levels of salinity, the damage caused by extreme salt concentrations in the soil, has created a need to explore stress-responsive traits and decode their mechanisms. Metallothioneins (MTs) are low-molecular-weight cysteine-rich proteins that are known to play a role in decreasing oxidative damage during abiotic stress conditions. Our previous study identified date palm metallothionein 2A (PdMT2A) as a salt-responsive gene, which has been functionally characterized in yeast and Arabidopsis in this study. The recombinant PdMT2A protein produced in Escherichia coli showed high reactivity against the substrate 5'-dithiobis-2-nitrobenzoic acid (DTNB), implying that the protein has the property of scavenging reactive oxygen species (ROS). Heterologous overexpression of PdMT2A in yeast (Saccharomyces cerevisiae) conferred tolerance to drought, salinity and oxidative stresses. The PdMT2A gene was also overexpressed in Arabidopsis, to assess its stress protective function in planta. Compared to the wild-type control, the transgenic plants accumulated less Na+ and maintained a high K+/Na+ ratio, which could be attributed to the regulatory role of the transgene on transporters such as HKT, as demonstrated by qPCR assay. In addition, transgenic lines exhibited higher chlorophyll content, higher superoxide dismutase (SOD) activity and improved scavenging ability for reactive oxygen species (ROS), coupled with a better survival rate during salt stress conditions. Similarly, the transgenic plants also displayed better drought and oxidative stress tolerance. Collectively, both in vitro and in planta studies revealed a role for PdMT2A in salt, drought, and oxidative stress tolerance.