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PloS One 2021Prostaglandins are thought to be important mediators in the initiation of human labour, however the evidence supporting this is not entirely clear. Determining how, and...
Prostaglandins are thought to be important mediators in the initiation of human labour, however the evidence supporting this is not entirely clear. Determining how, and which, prostaglandins change during pregnancy and labour may provide insight into mechanisms governing labour initiation and the potential to predict timing of labour onset. The current study systematically searched the existing scientific literature to determine how biofluid levels of prostaglandins change throughout pregnancy before and during labour, and whether prostaglandins and/or their metabolites may be useful for prediction of labour. The databases EMBASE and MEDLINE were searched for English-language articles on prostaglandins measured in plasma, serum, amniotic fluid, or urine during pregnancy and/or spontaneous labour. Studies were assessed for quality and risk of bias and a qualitative summary of included studies was generated. Our review identified 83 studies published between 1968-2021 that met the inclusion criteria. As measured in amniotic fluid, levels of PGE2, along with PGF2α and its metabolite 13,14-dihydro-15-keto-PGF2α were reported higher in labour compared to non-labour. In blood, only 13,14-dihydro-15-keto-PGF2α was reported higher in labour. Additionally, PGF2α, PGF1α, and PGE2 were reported to increase in amniotic fluid as pregnancy progressed, though this pattern was not consistent in plasma. Overall, the evidence supporting changes in prostaglandin levels in these biofluids remains unclear. An important limitation is the lack of data on the complexity of the prostaglandin pathway outside of the PGE and PGF families. Future studies using new methodologies capable of co-assessing multiple prostaglandins and metabolites, in large, well-defined populations, will help provide more insight as to the identification of exactly which prostaglandins and/or metabolites consistently change with labour. Revisiting and revising our understanding of the prostaglandins may provide better targets for clinical monitoring of pregnancies. This study was supported by the Canadian Institutes of Health Research.
Topics: Amniotic Fluid; Body Fluids; Databases, Factual; Dinoprost; Female; Humans; Labor Onset; Labor, Obstetric; Oxytocics; Plasma; Pregnancy; Prostaglandins; Prostaglandins E; Prostaglandins F; Serum; Urine
PubMed: 34793529
DOI: 10.1371/journal.pone.0260115 -
Theriogenology Mar 2022Induction of farrowing with prostaglandins is a way of increasing farrowing supervision and to provide adequate care for piglets in the first hours of life. However,... (Meta-Analysis)
Meta-Analysis
Induction of farrowing with prostaglandins is a way of increasing farrowing supervision and to provide adequate care for piglets in the first hours of life. However, some studies observed negative effects associated with induction, including decreased piglet viability, reduced birth weight and decreased colostrum yield. Furthermore, the farrowing response of sows to prostaglandins treatment varies among studies, largely influenced by the induction protocol applied. Thus, a systematic review and meta-analysis was carried out to evaluate the effects of farrowing induction with prostaglandins on stillbirth rate, birth weight, pre-weaning mortality, weaning weight, farrowing duration and colostrum and milk characteristics as well as the farrowing response to prostaglandin treatment. The interval from farrowing induction to onset of farrowing (IFIOF) was 31 h, and a twice application of prostaglandin increased by 37% the proportion of sows farrowing during the next working day. Prostaglandins had no effect on farrowing duration (P > 0.05). Piglet birth weight and weaning weight were only decreased (P < 0.05) when farrowing was induced ≥3 days before the expected farrowing date (based on herd average or in gestational length of the control group). Induction three or two days before the expected farrowing date had no effect on stillbirth rate; conversely, stillbirth rate was reduced by 28% (P < 0.05) when induction was performed one day before the expected farrowing date. Farrowing induction had no influence on pre-weaning mortality. The present study strengthened the observations that farrowing induction with prostaglandins is a valuable tool to reduce gestational length variation and to synchronize farrowing during the working day, allowing better assistance to sows and piglets. To obtain the maximum benefit of farrowing induction, it is recommended that induction should be performed one or two days before the expected farrowing date.
Topics: Animals; Colostrum; Female; Oxytocics; Parturition; Pregnancy; Prostaglandins; Swine; Weaning
PubMed: 34929429
DOI: 10.1016/j.theriogenology.2021.12.010 -
Toxicology Letters Aug 2020Oxidative stress is defined as an imbalance between the production and elimination of reactive oxygen species (ROS) are associated with various inflammation-related... (Meta-Analysis)
Meta-Analysis
Oxidative stress is defined as an imbalance between the production and elimination of reactive oxygen species (ROS) are associated with various inflammation-related human disease. ROS can oxidize lipids, which subsequently undergo fragmentation to produce F2-isoprostanes (F2-IsoPs). Eight-isoprostane is one of the most extensively studied F2-IsoPs and the most commonly used biomarker for the assessment of oxidative stress in human studies. This urinary biomarker is quantified using either chemical or immunological techniques. A "physiological" range for 8-isoprostanes is needed to use this biomarker as a measure of excess oxidative stress originating from occupational exposures. However, ranges reported in the literature are inconsistent. We designed a standardized protocol of a systematic review and meta-analysis to assess baseline values for 8-isoprostane concentrations in urine of healthy adults and identify determinants of their inter- and intra-individual variability. We searched PubMed from journal inception and up to April 2019, and screened articles for studies containing F2-IsoPs concentrations in urine for healthy adult participants. We grouped studies in three biomarker groups: "8-isoprostane", "Isoprostanes" "15- F2t-Isoprostane". We computed geometric mean (GM) and geometric standard deviation (GSD) as the basis for the meta-analysis. Of the initial 1849 articles retrieved, 63 studies were included and 107 subgroups within these study populations were identified. We stratified the subgroups analyzed with the chemical methods by body mass index (BMI) reported. We provide pooled GM values for urinary 8-isoprostane concentrations in healthy adults, separately for chemical and immunological analysis in this review. The interquartile range (IQR) in subgroups with a mean BMI below 25 measured using chemical methods was 0.18 to 0.40 μg/g creatinine. We show that there is a significant positive association between BMI and urinary 8-isoprostane concentrations. We recommend adjusting urinary 8-isoprostane concentrations in spot urine with creatinine, quantifying 8-isoprostane with chemical analytical methods, and reporting results as median and quartiles. This will help in comparing results across studies.
Topics: Adult; Biomarkers; Dinoprost; Environmental Exposure; Humans; Oxidative Stress; Smoking; Xenobiotics
PubMed: 32320775
DOI: 10.1016/j.toxlet.2020.04.006 -
Ageing Research Reviews Feb 2022The association between F-isoprostanes and Alzheimer's disease (AD) has been controversially discussed in the literature since the 1990s. However, no systematic review... (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
The association between F-isoprostanes and Alzheimer's disease (AD) has been controversially discussed in the literature since the 1990s. However, no systematic review has been performed so far.
METHODS
A systematic review of observational studies on the associations of F-isoprostanes and the specific biomarker 8-iso-prostaglandin F with AD were conducted. Random-effects model meta-analyses were performed.
RESULTS
29 studies were included in the systematic review, including four longitudinal studies. In an overall meta-analysis of the 25 cross-sectional studies, F-isoprostane levels were statistically significantly associated with AD (Hedge's g [95% confidence interval]: 1.00 [0.69-1.32]). When studies were grouped by biomarker and sample specimen, F-isoprostane and 8-iso-prostaglandin F levels were statistically significantly elevated in tissue samples of the frontal lobe of AD patients. Moreover, F-isoprostane levels in cerebrospinal fluid and 8-iso-prostaglandin F levels in blood samples of AD patients were significantly increased. Meta-analyses of the few longitudinal studies did not reach statistical significance.
DISCUSSION
Increased concentrations of F-isoprostanes were found in AD patients. However, due to the lack of adjustment in most cross-sectional case-control studies, results must be interpreted carefully. In addition, the causality of the association is uncertain because evidence from well-conducted longitudinal studies was conflicting, and further longitudinal studies are required to reinforce the results.
Topics: Alzheimer Disease; Cross-Sectional Studies; Dinoprost; F2-Isoprostanes; Humans; Isoprostanes; Oxidative Stress
PubMed: 34954419
DOI: 10.1016/j.arr.2021.101552 -
International Journal of Molecular... May 2020Isoprostanes are physiopathologic mediators of oxidative stress, resulting in lipid peroxidation. 8-isoprostane seems particularly useful for measuring oxidative stress... (Meta-Analysis)
Meta-Analysis
Isoprostanes are physiopathologic mediators of oxidative stress, resulting in lipid peroxidation. 8-isoprostane seems particularly useful for measuring oxidative stress damage. However, no reference range values are available for 8-isoprosante in exhaled breath condensate (EBC) of healthy adults, enabling its meaningful interpretation as a biomarker. We conducted this systematic review and meta-analysis according to the protocol following PROSPERO (CRD42020146623). After searching and analyzing the literature, we included 86 studies. After their qualitative synthesis and risk of bias assessment, 52 studies were included in meta-analysis. The latter focused on studies using immunological analytical methods and investigated how the concentrations of 8-isoprostane differ based on gender. We found that gender had no significant effect in 8-isoprostane concentration. Among other studied factors, such as individual characteristics and factors related to EBC collection, only the device used for EBC collection significantly affected measured 8-isoprostane concentrations. However, adjustment for the factors related to EBC collection, yielded uncertainty whether this effect is due to the device itself or to the other factors. Given this uncertainty, we estimated the reference range values of 8-isoprostane stratified by gender and EBC collection device. A better standardization of EBC collection seems necessary; as well more studies using chemical analytical methods to extend this investigation.
Topics: Asthma; Biomarkers; Breath Tests; Dinoprost; Exhalation; Female; Healthy Volunteers; Humans; Inflammation; Lung; Male; Nitric Oxide; Oxidative Stress; Reference Values; Sex Factors
PubMed: 32481492
DOI: 10.3390/ijms21113822