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Journal of Trace Elements in Medicine... Jul 2024Contamination with heavy metals (HM) has great environmental consequences in the environment due to lack of biodegradation, in addition, accumulation in living beings... (Review)
Review
STATEMENT OF PROBLEM
Contamination with heavy metals (HM) has great environmental consequences in the environment due to lack of biodegradation, in addition, accumulation in living beings causes defects in tissues and organs, deteriorating their function and inducing a wide spectrum of diseases. Human biomonitoring consists of the periodic measurement of a certain chemical substance or metabolite in a particular population, using matrices that can be acute or chronic. Teeth are chronic matrices that have great characteristics of resistance and chronological storage of information. This review aims to identify the mechanisms, spatial location, and affinity of HM within teeth, along with understanding its applicability as a chronological record matrix in the face of HM contamination.
MATERIAL AND METHODS
A systematic search review was performed using the PubMed/Medline, Web of Science, and Scopus metasearch engines, and the terms "teeth" OR "dental" OR "tooth" AND "heavy metals" were intersected. Complete articles are included in Spanish, English and Portuguese without time restrictions, involving studies in humans or in vitro; Letters to the editor, editorials and those that did not refer to information on the incorporation and relationship of HM with the teeth were excluded.
RESULTS
837 published articles were detected, 91 were adjusted to the search objective, and 6 were manually included. Teeth are structures with a great capacity for information retention in the face of HM contamination due to low physiological turnover and their long processes of marked formations by developmental biorhythm milestones such as the neonatal line (temporal reference indicator). The contamination mechanisms inside the tooth are linked to the affinity of hydroxyapatite for HM; this incorporation can be in the soft matrix during the apposition phase or as part of the chemical exchanges between hydroxyapatite and the elements of the environment.
CONCLUSION
The teeth present unique characteristics of great resistance and affinity for HM, as well as a chronological biomarker for human biomonitoring, so they can be used as means of expertise or evidence to confirm or rule out a fact of environmental characteristics in the legal field.
Topics: Humans; Biomarkers; Metals, Heavy; Tooth, Deciduous; Dentition, Permanent
PubMed: 38547726
DOI: 10.1016/j.jtemb.2024.127435 -
International Journal of Molecular... May 2023Recurrent miscarriage (RM) can be defined as two or more consecutive miscarriages before 20 weeks' gestation. Vascular endothelial growth factors (VEGFs) play an... (Review)
Review
Recurrent miscarriage (RM) can be defined as two or more consecutive miscarriages before 20 weeks' gestation. Vascular endothelial growth factors (VEGFs) play an important role in endometrial angiogenesis and decidualization, prerequisites for successful pregnancy outcomes. We conducted a systematic review of the published literature investigating the role of VEGFs in RM. In particular, we explored the methodological inconsistencies between the published reports on this topic. To our knowledge, this is the first systematic literature review to examine the role of VEGFs in RM. Our systematic search followed PRISMA guidelines. Three databases, Medline (Ovid), PubMed, and Embase, were searched. Assessment-bias analyses were conducted using the Joanna Bigger Institute critical appraisal method for case-control studies. Thirteen papers were included in the final analyses. These studies included 677 cases with RM and 724 controls. Endometrial levels of VEGFs were consistently lower in RM cases compared to controls. There were no consistent significant findings with respect to VEGFs levels in decidua, fetoplacental tissues, and serum when RM cases were compared to controls. The interpretation of studies that explored the relationship between VEGFs and RM is hampered by inconsistencies in defining clinical, sampling, and analytical variables. To clarify the association between VEGF and RM in future studies, researchers ideally should use similarly defined clinical groups, similar samples collected in the same way, and laboratory analyses undertaken using the same methods.
Topics: Pregnancy; Female; Humans; Vascular Endothelial Growth Factor A; Abortion, Habitual; Vascular Endothelial Growth Factors; Pregnancy Outcome; Endometrium
PubMed: 37298399
DOI: 10.3390/ijms24119449 -
Biology of Reproduction Aug 2023The fallopian tubes (FTs) are part of the female upper genital tract. The healthy FT provides the biological environment for successful fertilization and facilitates the...
The fallopian tubes (FTs) are part of the female upper genital tract. The healthy FT provides the biological environment for successful fertilization and facilitates the subsequent movement of the conceptus to the endometrial cavity. However, when the FT is damaged, as with salpingitis, pyosalpinx, and hydrosalpinx, it may increase the risk of an ectopic pregnancy, a life-threatening condition. Decidualization refers to a multifactorial process by which the endometrium changes to permit blastocyst implantation. The decidualization reaction is vital for endometrial receptivity during the window of implantation. To date, no comprehensive review that collates evidence on decidualization in the human FT has been conducted. Therefore, the aim of this review is to compile the current evidence on cellular decidualization occurring in the healthy and pathological FT in women of reproductive age. A literature search was conducted using five databases and identified 746 articles, 24 of which were analyzed based on inclusion and exclusion criteria. The available evidence indicates that the FT are able to undergo decidual changes under specific circumstances; however, the exact mechanism by which this occurs is poorly understood. Further research is needed to elucidate the mechanism by which decidualization can occur in the FT.
Topics: Pregnancy; Female; Humans; Fallopian Tubes; Endometrium; Embryo Implantation; Uterus; Decidua; Stromal Cells
PubMed: 37265359
DOI: 10.1093/biolre/ioad062 -
Gynecologic and Obstetric Investigation 2023The uterine caesarean scar defect, also known as uterine niche or isthmocele, is an irregularity in the anterior uterine wall at the site of a previous cesarean section...
INTRODUCTION
The uterine caesarean scar defect, also known as uterine niche or isthmocele, is an irregularity in the anterior uterine wall at the site of a previous cesarean section scar. It is associated with obstetrical complications such as caesarean scar, ectopic pregnancy, uterine rupture, and the placenta accreta spectrum. Women with cesarean scar defects are frequently asymptomatic but may also experience abnormal vaginal bleeding, chronic pelvic pain, and infertility.
METHODS
This systematic review aims to determine the best hysterotomy closure technique to prevent subsequent development of uterine scar defects. An electronic search in Medline, Embase, Cochrane Database of Systematic Reviews, ClinicalTrials.gov was performed from January 2001 until December 2020 for studies evaluating hysterotomy closure techniques.
RESULTS
Our systematic search strategy identified 1,781 titles. Six studies fulfilled inclusion criteria and were included in the final analysis. The results supported the superiority of the double-layer closure over the single-layer closure.
CONCLUSIONS
Hysterotomy closure with continuous running sutures in two layers represents a suitable option to prevent cesarean scar defect formation. Particularly, the first layer should include the decidua and the second layer should overlap the first.
Topics: Female; Humans; Pregnancy; Cesarean Section; Cicatrix; Hysterotomy; Uterus
PubMed: 36724750
DOI: 10.1159/000528144 -
Frontiers in Immunology 2022Recurrent spontaneous abortion (RSA) is defined as two or more pregnancy loss, affecting the happiness index of fertility couples. The mechanisms involved in the...
Recurrent spontaneous abortion (RSA) is defined as two or more pregnancy loss, affecting the happiness index of fertility couples. The mechanisms involved in the occurrence of RSA are not clear to date. The primary problem for the maternal immune system is how to establish and maintain the immune tolerance to the semi-allogeneic fetuses. During the pregnancy, decidual macrophages mainly play an important role in the immunologic dialogue. The purpose of this study is to explore decidual macrophages, and to understand whether there is a connection between these cells and RSA by analyzing their phenotypes and functions. Pubmed, Web of Science and Embase were searched. The eligibility criterion for this review was evaluating the literature about the pregnancy and macrophages. Any disagreement between the authors was resolved upon discussion and if required by the judgment of the corresponding author. We summarized the latest views on the phenotype, function and dysfunction of decidual macrophages to illuminate its relationship with RSA.
Topics: Pregnancy; Humans; Female; Decidua; Abortion, Habitual; Macrophages; Abortion, Induced
PubMed: 36569856
DOI: 10.3389/fimmu.2022.994888 -
Fertility and Sterility Jun 2022Implantation is a critical step in the establishment of a successful pregnancy, depending on a complex immune-endocrine dialogue between the developing embryo and... (Meta-Analysis)
Meta-Analysis Review
Implantation is a critical step in the establishment of a successful pregnancy, depending on a complex immune-endocrine dialogue between the developing embryo and maternal endometrium. Research suggests that altered immunity in the maternal decidua results in implantation impairment and failure. Immunomodulatory drugs have, thus, been widely used in assisted conception to aid embryo implantation, despite an absence of consensus on their effectiveness and safety. We conducted a systematic review and meta-analysis of interventional studies investigating the use of immunomodulators in women undergoing assisted reproduction. Evidence was uncertain of an effect for most of the included interventions, owing to heterogeneous findings and a paucity of high-quality studies. For certain patient subgroups, however, the use of specific immunomodulatory therapies may offer some benefit. There is a need for further large randomized controlled trials to corroborate these findings.
Topics: Embryo Implantation; Endometrium; Female; Fertilization in Vitro; Humans; Immunotherapy; Infertility; Pregnancy
PubMed: 35618357
DOI: 10.1016/j.fertnstert.2022.04.015 -
Frontiers in Immunology 2022Mesenchymal stromal cells (MSCs) possess profound immunomodulatory and regenerative properties that are of clinical use in numerous clinical indications with unmet... (Meta-Analysis)
Meta-Analysis
Mesenchymal stromal cells (MSCs) possess profound immunomodulatory and regenerative properties that are of clinical use in numerous clinical indications with unmet medical need. Common sources of MSCs include among others, bone marrow (BM), fat, umbilical cord, and placenta-derived decidua stromal cells (DSCs). We here summarize our more than 20-years of scientific experience in the clinical use of MSCs and DSCs in different clinical settings. BM-MSCs were first explored to enhance the engraftment of autografts in hematopoietic cell transplantation (HCT) and osteogenesis imperfecta around 30 years ago. In 2004, our group reported the first anti-inflammatory use of BM-MSCs in a child with grade IV acute graft-versus-host disease (GvHD). Subsequent studies have shown that MSCs appear to be more effective in acute than chronic GvHD. Today BM-MSC-therapy is registered for acute GvHD in Japan and for GvHD in children in Canada and New Zeeland. MSCs first home to the lung following intravenous injection and exert strong local and systemic immunomodulatory effects on the host immune system. Thus, they were studied for ameliorating the cytokine storm in acute respiratory distress syndrome (ARDS). Both, MSCs and DSCs were used to treat SARS-CoV-2 coronavirus-induced disease 2019 (COVID-19)-induced ARDS. In addition, they were also used for other novel indications, such as pneumomediastinum, colon perforation, and radiculomyelopathy. MSC and DSCs trigger coagulation and were thus explored to stop hemorrhages. DSCs appear to be more effective for acute GvHD, ARDS, and hemorrhages, but randomized studies are needed to prove superiority. Stromal cell infusion is safe, well tolerated, and only gives rise to a slight fever in a limited number of patients, but no major side effects have been reported in multiple safety studies and metaanalysis. In this review we summarize current evidence from studies, animal models, and importantly our clinical experience, to support stromal cell therapy in multiple clinical indications. This encloses MSC's effects on the immune system, coagulation, and their safety and efficacy, which are discussed in relation to prominent clinical trials within the field.
Topics: Animals; COVID-19; Female; Graft vs Host Disease; Hematopoietic Stem Cell Transplantation; Hemorrhage; Humans; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Pregnancy; Respiratory Distress Syndrome; SARS-CoV-2
PubMed: 35371003
DOI: 10.3389/fimmu.2022.839844 -
Human Reproduction Update Jun 2022Uterine natural killer cells (uNK) are the most abundant lymphocytes found in the decidua during implantation and in first trimester pregnancy. They are important for... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Uterine natural killer cells (uNK) are the most abundant lymphocytes found in the decidua during implantation and in first trimester pregnancy. They are important for early placental development, especially trophoblast invasion and transformation of the spiral arteries. However, inappropriate uNK function has been implicated in reproductive failure, such as recurrent miscarriage (RM) or recurrent implantation failure (RIF). Previous studies have mainly focussed on peripheral NK cells (pNK), despite the well-documented differences in pNK and uNK phenotype and function. In recent years, there has been an explosion of studies conducted on uNK, providing a more suitable representation of the immune environment at the maternal-foetal interface. Here, we summarize the evidence from studies published on uNK in women with RM/RIF compared with controls.
OBJECTIVE AND RATIONALE
The objectives of this systematic review and meta-analysis are to evaluate: differences in uNK level in women with RM/RIF compared with controls; pregnancy outcome in women with RM/RIF stratified by high and normal uNK levels; correlation between uNK and pNK in women with RM/RIF; and differences in uNK activity in women with RM/RIF compared with controls.
SEARCH METHODS
MEDLINE, EMBASE, Web of Science and Cochrane Trials Registry were searched from inception up to December 2020 and studies were selected in accordance with PRISMA guidelines. Meta-analyses were performed for uNK level, pregnancy outcome and uNK/pNK correlation. Narrative synthesis was conducted for uNK activity. Risk of bias was assessed by ROBINS-I and publication bias by Egger's test.
OUTCOMES
Our initial search yielded 4636 articles, of which 60 articles were included in our systematic review. Meta-analysis of CD56+ uNK level in women with RM compared with controls showed significantly higher levels in women with RM in subgroup analysis of endometrial samples (standardized mean difference (SMD) 0.49, CI 0.08, 0.90; P = 0.02; I2 88%; 1100 women). Meta-analysis of CD56+ uNK level in endometrium of women with RIF compared with controls showed significantly higher levels in women with RIF (SMD 0.49, CI 0.01, 0.98; P = 0.046; I2 84%; 604 women). There was no difference in pregnancy outcome in women with RM/RIF stratified by uNK level, and no significant correlation between pNK and uNK levels in women with RM/RIF. There was wide variation in studies conducted on uNK activity, which can be broadly divided into regulation and receptors, uNK cytotoxicity, cytokine secretion and effect of uNK on angiogenesis. These studies were largely equivocal in their results on cytokine secretion, but most studies found lower expression of inhibitory receptors and increased expression of angiogenic factors in women with RM.
WIDER IMPLICATIONS
The observation of significantly increased uNK level in endometrium of women with RM and RIF may point to an underlying disturbance of the immune milieu culminating in implantation and/or placentation failure. Further research is warranted to elucidate the underlying pathophysiology. The evidence for measuring pNK as an indicator of uNK behaviour is sparse, and of limited clinical use. Measurement of uNK level/activity may be more useful as a diagnostic tool, however, a standardized reference range must be established before this can be of clinical use.
Topics: Abortion, Habitual; Cytokines; Embryo Implantation; Endometrium; Female; Humans; Killer Cells, Natural; Placenta; Pregnancy; Uterus
PubMed: 35265977
DOI: 10.1093/humupd/dmac006 -
Frontiers in Immunology 2021Several studies report the role of Regulatory T-cells (Tregs) in the pathophysiology of pregnancy adverse outcomes. (Meta-Analysis)
Meta-Analysis
BACKGROUND
Several studies report the role of Regulatory T-cells (Tregs) in the pathophysiology of pregnancy adverse outcomes.
OBJECTIVE
The aim of this systematic review and meta-analysis was to determine whether there is an association between regulatory T cell levels and pregnancy adverse outcomes (PAOs), including pre-eclampsia and preterm birth (PTB).
METHOD
Literature searches were conducted in PubMed/MEDLINE, Embase, and Cochrane CENTRAL databases. Inclusion criteria were original articles (clinical trials, case-control studies and cohort studies) comparing Tregs, sampled from the decidua or maternal blood, in healthy pregnant women women with pre-eclampsia or PTB. The outcome was standardised mean difference (SMD) in Treg numbers. The tau-squared (Tau²), inconsistency index (I²), and chi-squared (χ²) test quantified heterogeneity among different studies. Analyses were performed in RevMan software V.5.4.0 for Mac using a random-effects model with outcome data reported with 95% confidence intervals (CI). This study was prospectively registered with PROSPERO (CRD42020205469). PRISMA guidelines were followed.
RESULTS
From 4,085 unique studies identified, 36 were included in qualitative synthesis, and 34 were included in quantitative synthesis (meta-analysis). In total, there were 1,783 participants in these studies: healthy controls=964, pre-eclampsia=759, PTB=60. Thirty-two studies compared Tregs in healthy pregnant women and women with pre-eclampsia, and 30 of these sampled Tregs from peripheral blood showing significantly higher Treg numbers in healthy pregnancies (SMD; 1.46; 95% CI, 1.03-1.88; I²=92%). Four studies sampled Tregs from the maternal decidua showing higher Tregs in healthy pregnancies (SMD, 0.76; 95% CI, -0.13-1.65; I²=84%). No difference was found in the number of Tregs between early late pre-eclampsia (SMD,-1.17; 95% CI, -2.79-0.44; I²=94%). For PTB, two studies compared Tregs sampled from the peripheral blood with a tendency for higher Tregs in healthy pregnancies but this did not reach significance (SMD, 2.18; 95% CI, -1.34-5.70; I²=96%). Subcohort analysis using Treg analysis (flow cytometry qPCR immunofluorescence tissue staining) showed similar associations.
CONCLUSION
Lower Tregs in pregnancy, sampled from the maternal peripheral blood, are associated with pre-eclampsia. There is a need for further studies to confirm a relationship between low Tregs and PTB. As the precise mechanisms by which Tregs may mediate pre-eclampsia and PTB remain unclear, further fundamental research is necessary to elucidate the underlying processes and highlight the causative link.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO, identifier CRD42020205469.
Topics: Adult; CD4 Lymphocyte Count; Female; Humans; Phenotype; Predictive Value of Tests; Pregnancy; Pregnancy Complications; Pregnancy Outcome; Risk Assessment; Risk Factors; T-Lymphocytes, Regulatory
PubMed: 34777347
DOI: 10.3389/fimmu.2021.737862 -
Frontiers in Physiology 2021Genome-wide transcriptomic studies on gestational tissues in labor provide molecular insights in mechanism of normal parturition. This systematic review aimed to...
Genome-wide transcriptomic studies on gestational tissues in labor provide molecular insights in mechanism of normal parturition. This systematic review aimed to summarize the important genes in various gestational tissues around labor onset, and to dissect the underlying molecular regulations and pathways that trigger the labor in term pregnancies. PubMed and Web of Science were searched from inception to January 2021. Untargeted genome-wide transcriptomic studies comparing the gene expression of various gestational tissues in normal term pregnant women with and without labor were included. Every differentially expressed gene was retrieved. Consistently expressed genes with same direction in different studies were identified, then gene ontology and KEGG analysis were conducted to understand molecular pathways and functions. Gene-gene association analysis was performed to determine the key regulatory gene(s) in labor onset. A total of 15 studies, including 266 subjects, were included. 136, 26, 15, 7, and 3 genes were significantly changed during labor in the myometrium (seven studies, = 108), uterine cervix (four studies, = 64), decidua (two studies, = 42), amnion (two studies, = 44) and placenta (two studies, = 41), respectively. These genes were overrepresented in annotation terms related to inflammatory and immune responses. TNF and NOD-like receptor signaling pathways were overrepresented in all mentioned tissues, except the placenta. was the only gene included in both pathways, the most common reported gene in all included studies, and also the gene in the central hub of molecular regulatory network. This systematic review identified that genes involved in immunological and inflammatory regulations are expressed in specific gestational tissues in labor. We put forward the hypothesis that IL6 might be the key gene triggering specific mechanism in different gestational tissues, eventually leading to labor onset through inducing uterine contraction, wakening fetal membranes and stimulating cervical ripening. Identifier [CRD42020187975].
PubMed: 34566691
DOI: 10.3389/fphys.2021.730030