scholarly journals Molecular Drivers of Developmental Arrest in the Human Preimplantation Embryo: A Systematic Review and Critical Analysis Leading to Mapping Future Research

2021 ◽  
Vol 22 (15) ◽  
pp. 8353
Author(s):  
Konstantinos Sfakianoudis ◽  
Evangelos Maziotis ◽  
Eleni Karantzali ◽  
Georgia Kokkini ◽  
Sokratis Grigoriadis ◽  
...  
Keyword(s):  
Systematic Review ◽  
Critical Analysis ◽  
Common Ground ◽  
Preimplantation Embryo ◽  
Preimplantation Embryos ◽  
Future Research ◽  
Parental Factors ◽  
Arrested Development ◽  
Developmental Arrest ◽  
Mitochondrial Dna Copy Number

Developmental arrest of the preimplantation embryo is a multifactorial condition, characterized by lack of cellular division for at least 24 hours, hindering the in vitro fertilization cycle outcome. This systematic review aims to present the molecular drivers of developmental arrest, focusing on embryonic and parental factors. A systematic search in PubMed/Medline, Embase and Cochrane-Central-Database was performed in January 2021. A total of 76 studies were included. The identified embryonic factors associated with arrest included gene variations, mitochondrial DNA copy number, methylation patterns, chromosomal abnormalities, metabolic profile and morphological features. Parental factors included, gene variation, protein expression levels and infertility etiology. A valuable conclusion emerging through critical analysis indicated that genetic origins of developmental arrest analyzed from the perspective of parental infertility etiology and the embryo itself, share common ground. This is a unique and long-overdue contribution to literature that for the first time presents an all-inclusive methodological report on the molecular drivers leading to preimplantation embryos’ arrested development. The variety and heterogeneity of developmental arrest drivers, along with their inevitable intertwining relationships does not allow for prioritization on the factors playing a more definitive role in arrested development. This systematic review provides the basis for further research in the field.

scholarly journals Parent-child connectedness : moving beyond traditional attachment theory

2021 ◽  
Author(s):  
Rachel Lechcier-Kimel
Keyword(s):  
Systematic Review ◽  
Attachment Theory ◽  
Current Literature ◽  
Critical Analysis ◽  
Future Research ◽  
Gender Culture ◽  
Extensive Evaluation ◽  
Theoretical Foundations ◽  
Parent Child

The present paper provides a systematic review of the current literature on parent-child connectedness (PCC) through a critical analysis of existing research on the topic. By focusing on the numerous ways the construct of PCC extends beyond the scope of traditional attachment theory, this paper attempts to make PCC more relevant to individuals of varied age, gender, culture and socioeconomic backgrounds. An explanation of PCC as a dependent variable is presented as a means of strengthening the understanding of the construct, and an extensive evaluation of its theoretical foundations is included in order to operationalize this understanding. This paper concludes by suggesting the benefit in broadening the awareness of PCC and by providing recommendations for future research.

Cytogenetic analysis of human preimplantation embryos following developmental arrest in vitro

1998 ◽  
Vol 10 (6) ◽  
pp. 505 ◽  
Author(s):  
Paula A. Almeida ◽  
Virginia N. Bolton
Keyword(s):  
Chromosomal Abnormality ◽  
Cytogenetic Analysis ◽  
Chromosomal Abnormalities ◽  
Preimplantation Embryo ◽  
Preimplantation Embryos ◽  
Cell Stage ◽  
Developmental Arrest ◽  
The Relationship ◽  
Human Preimplantation Embryos

The relationship between chromosomal abnormalities in the human preimplantation embryo and developmental arrest in vitro was investigated. Cytogenetic analysis of 171 embryos that had arrested between the pronucleate and the 8-cell stages demonstrated that the overall incidence of chromosomal abnormality among these embryos was 63.4%. Of the embryos that arrested at the pronucleate stage (n = 48), 47.9% were chromosomally abnormal, compared with 59.5% of those that arrested between the 2- and 4-cell stages (n = 50), and 82.8% of those arrested between the 5- and 8-cell stage (n = 73). The rate of abnormality in embryos with poor morphology (irregular shaped blastomeres and considerable extracellular fragmentation) was significantly higher (86.8%; n = 33) than those with good morphology (60%; n = 51; P<0.005). These results suggest that there is an association between chromosomal abnormality, developmental arrest in vitro, and poor morphology.

scholarly journals Parent-child connectedness : moving beyond traditional attachment theory

2021 ◽  
Author(s):  
Rachel Lechcier-Kimel
Keyword(s):  
Systematic Review ◽  
Attachment Theory ◽  
Current Literature ◽  
Critical Analysis ◽  
Future Research ◽  
Gender Culture ◽  
Extensive Evaluation ◽  
Theoretical Foundations ◽  
Parent Child

The present paper provides a systematic review of the current literature on parent-child connectedness (PCC) through a critical analysis of existing research on the topic. By focusing on the numerous ways the construct of PCC extends beyond the scope of traditional attachment theory, this paper attempts to make PCC more relevant to individuals of varied age, gender, culture and socioeconomic backgrounds. An explanation of PCC as a dependent variable is presented as a means of strengthening the understanding of the construct, and an extensive evaluation of its theoretical foundations is included in order to operationalize this understanding. This paper concludes by suggesting the benefit in broadening the awareness of PCC and by providing recommendations for future research.

scholarly journals Metabolism of the preimplantation embryo: 40 years on

Reproduction ◽  
2012 ◽  
Vol 143 (4) ◽  
pp. 417-427 ◽  
Author(s):  
Henry J Leese
Keyword(s):  
Preimplantation Embryo ◽  
Early Embryo ◽  
Preimplantation Embryos ◽  
Future Research ◽  
Response Models ◽  
Health And Disease ◽  
Fundamental Research ◽  
Embryo Metabolism ◽  
Methodological Difficulties

This review considers how our understanding of preimplantation embryo metabolism has progressed since the pioneering work on this topic in the late 1960s and early 1970s. Research has been stimulated by a desire to understand how metabolic events contribute to the development of the zygote into the blastocyst, the need for biomarkers of embryo health with which to improve the success of assisted conception technologies, and latterly by the ‘Developmental Origins of Health and Disease’ (DOHaD) concept. However, arguably, progress has not been as great as it might have been due to methodological difficulties in working with tiny amounts of tissue and the low priority assigned to fundamental research on fertility and infertility, with developments driven more by technical than scientific advances. Nevertheless, considerable progress has been made in defining the roles of the traditional nutrients: pyruvate, glucose, lactate, and amino acids; originally considered as energy sources and biosynthetic precursors, but now recognized as having multiple, overlapping functions. Other nutrients; notably lipids, are beginning to attract the attention they deserve. The pivotal role of mitochondria in early embryo development and the DOHaD concept, and in providing a cellular focus for metabolic events is now recognized. Some unifying ideas are discussed; namely ‘stress–response models’ and the ‘quiet embryo hypothesis’; the latter aiming to relate the metabolism of individual preimplantation embryos to their subsequent viability. The review concludes by updating the state of knowledge of preimplantation embryo metabolism in the early 1970s and listing some future research questions.

scholarly journals Reporting on the Role of miRNAs and Affected Pathways on the Molecular Backbone of Ovarian Insufficiency: A Systematic Review and Critical Analysis Mapping of Future Research

2021 ◽  
Vol 8 ◽  
Author(s):  
Anna Rapani ◽  
Dimitra Nikiforaki ◽  
Dimitra Karagkouni ◽  
Konstantinos Sfakianoudis ◽  
Petroula Tsioulou ◽  
...  
Keyword(s):  
Critical Analysis ◽  
Common Ground ◽  
Gene Expression Regulation ◽  
Individualized Medicine ◽  
Gene Set Enrichment Analysis ◽  
Future Research ◽  
Common Denominator ◽  
Ovarian Insufficiency ◽  
The Common

Ovarian insufficiency is identified as a perplexing entity in the long list of pathologies impairing fertility dynamics. The three distinct classifications of ovarian insufficiency are poor ovarian response, premature ovarian insufficiency/failure, and advanced maternal age, sharing the common denominator of deteriorated ovarian reserve. Despite efforts to define clear lines among the three, the vast heterogeneity and overlap of clinical characteristics renders their diagnosis and management challenging. Lack of a consensus has prompted an empirically based management coupled by uncertainty from the clinicians’ perspective. Profiling of patients in the era of precision medicine seems to be the way forward, while the necessity for a novel approach is underlined. Implicating miRNAs in the quest for patient profiling is promising in light of their fundamental role in cellular and gene expression regulation. To this end, the current study sets out to explore and compare the three pathophysiologies—from a molecular point of view—in order to enable profiling of patients in the context of in vitro fertilization treatment and enrich the data required to practice individualized medicine. Following a systematic investigation of literature, data referring to miRNAs were collected for each patient category based on five included studies. miRNA–target pairs were retrieved from the DIANA-TarBase repository and microT-CDS. Gene and miRNA annotations were derived from Ensembl and miRbase. A subsequent gene-set enrichment analysis of miRNA targets was performed for each category separately. A literature review on the most crucial of the detected pathways was performed to reveal their relevance to fertility deterioration. Results supported that all three pathophysiologies share a common ground regarding the affected pathways, naturally attributed to the common denominator of ovarian insufficiency. As evidenced, miRNAs could be employed to explore the fine lines and diverse nature of pathophysiology since they constitute invaluable biomarkers. Interestingly, it is the differentiation through miRNAs and not through the molecular affected pathways that corresponds to the three distinctive categories. Alarming discrepancies among publications were revealed, pertaining to employment of empirical and arbitrary criteria in categorizing the patients. Following bioinformatic analysis, the final step of the current study consisted of a critical analysis of the molecular data sourced, providing a clear and unique insight into the physiological mechanisms involved. It is our intention to contribute to mapping future research dedicated to ovarian insufficiency and to help researchers navigate the overwhelming information published in molecular studies.

Telepractice for Adult Speech-Language Pathology Services: A Systematic Review

2020 ◽  
Vol 5 (1) ◽  
pp. 326-338 ◽  
Author(s):  
Kristen Weidner ◽  
Joneen Lowman
Keyword(s):  
Systematic Review ◽  
Primary Progressive Aphasia ◽  
Future Research ◽  
Service Delivery Model ◽  
Speech Language Pathology ◽  
Review Of The Literature ◽  
Research Designs ◽  
Assessment And Treatment ◽  
Language Pathology ◽  
Screening Assessment

Purpose We conducted a systematic review of the literature regarding adult telepractice services (screening, assessment, and treatment) from approximately 2014 to 2019. Method Thirty-one relevant studies were identified from a literature search, assessed for quality, and reported. Results Included studies illustrated feasibility, efficacy, diagnostic accuracy, and noninferiority of various speech-language pathology services across adult populations, including chronic aphasia, Parkinson's disease, dysphagia, and primary progressive aphasia. Technical aspects of the equipment and software used to deliver services were discussed. Some general themes were noted as areas for future research. Conclusion Overall, results of the review continue to support the use of telepractice as an appropriate service delivery model in speech-language pathology for adults. Strong research designs, including experimental control, across multiple well-described settings are still needed to definitively determine effectiveness of telepractice services.

Chasing the Anchor: A Systematic Review and Meta-analysis of Perceptual Anchoring Deficits in Developmental Dyslexia

2020 ◽  
Author(s):  
Kurt D Shulver ◽  
Nicholas A Badcock
Keyword(s):  
Systematic Review ◽  
Reading Ability ◽  
English Language ◽  
Prediction Interval ◽  
Meta Analysis ◽  
Visual Assessment ◽  
Individual Performance ◽  
Future Research ◽  
Significant Heterogeneity ◽  
Eligibility Criteria

We report the results of a systematic review and meta-analysis investigating the relationship between perceptual anchoring and dyslexia. Our goal was to assess the direction and degree of effect between perceptual anchoring and reading ability in typical and atypical (dyslexic) readers. We performed a literature search of experiments explicitly assessing perceptual anchoring and reading ability using PsycInfo (Ovid, 1860 to 2020), MEDLINE (Ovid, 1860 to 2019), EMBASE (Ovid, 1883 to 2019), and PubMed for all available years up to June (2020). Our eligibility criteria consisted of English-language articles and, at minimum, one experimental group identified as dyslexic - either by reading assessment at the time, or by previous diagnosis. We assessed for risk of bias using an adapted version of the Newcastle-Ottawa scale. Six studies were included in this review, but only five (n = 280 participants) were included in the meta-analysis (we were unable to access the necessary data for one study).The overall effect was negative, large and statistically significant; g = -0.87, 95% CI [-1.47, 0.27]: a negative effect size indicating less perceptual anchoring in dyslexic versus non-dyslexic groups. Visual assessment of funnel plot and Egger’s test suggest minimal bias but with significant heterogeneity; Q (4) = 9.70, PI (prediction interval) [-2.32, -0.58]. The primary limitation of the current review is the small number of included studies. We discuss methodological limitations, such as limited power, and how future research may redress these concerns. The variability of effect sizes appears consistent with the inherent variability within subtypes of dyslexia. This level of dispersion seems indicative of the how we define cut-off thresholds between typical reading and dyslexia populations, but also the methodological tools we use to investigate individual performance.

Impact of surgery timing for craniosynostosis on neurodevelopmental outcomes: a systematic review

2019 ◽  
Vol 23 (4) ◽  
pp. 442-454 ◽  
Author(s):  
Rachel Mandela ◽  
Maggie Bellew ◽  
Paul Chumas ◽  
Hannah Nash
Keyword(s):  
Systematic Review ◽  
Beneficial Effect ◽  
Data Extraction ◽  
Sociodemographic Factors ◽  
Future Research ◽  
Neurodevelopmental Outcomes ◽  
Age At Surgery ◽  
Data Extraction Form ◽  
Surgery Timing ◽  
Anesthetic Exposure

OBJECTIVEThere are currently no guidelines for the optimum age for surgical treatment of craniosynostosis. This systematic review summarizes and assesses evidence on whether there is an optimal age for surgery in terms of neurodevelopmental outcomes.METHODSThe databases MEDLINE, PsycINFO, CINAHL, Embase + Embase Classic, and Web of Science were searched between October and November 2016 and searches were repeated in July 2017. According to PICO (participants, intervention, comparison, outcome) criteria, studies were included that focused on: children diagnosed with nonsyndromic craniosynostosis, aged ≤ 5 years at time of surgery; corrective surgery for nonsyndromic craniosynostosis; comparison of age-at-surgery groups; and tests of cognitive and neurodevelopmental postoperative outcomes. Studies that did not compare age-at-surgery groups (e.g., those employing a correlational design alone) were excluded. Data were double-extracted by 2 authors using a modified version of the Cochrane data extraction form.RESULTSTen studies met the specified criteria; 5 found a beneficial effect of earlier surgery, and 5 did not. No study found a beneficial effect of later surgery. No study collected data on length of anesthetic exposure and only 1 study collected data on sociodemographic factors.CONCLUSIONSIt was difficult to draw firm conclusions from the results due to multiple confounding factors. There is some inconclusive evidence that earlier surgery is beneficial for patients with sagittal synostosis. The picture is even more mixed for other subtypes. There is no evidence that later surgery is beneficial. The authors recommend that future research use agreed-upon parameters for: age-at-surgery cut-offs, follow-up times, and outcome measures.

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