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Nutritional Deficiencies
Published in Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw, Hankey's Clinical Neurology, 2020
Deepa Bhupali, Fernando D. Testai
Neurologic: Depression.Cognitive decline.Myelopathy.Neuropathy.Seizures (infancy).Neural tube defect (embryogenesis).
Developmental Disorders
Published in Jeremy R. Jass, Understanding Pathology, 2020
The pathology of development encompasses processes related to extra-embryonic tissues (placenta), formation of the embryo (embryogenesis), growth of the fetus, birth and adaptation to life outside the uterus (Wigglesworth, 1992). In this brief overview the focus will be on problems presenting at or after birth. The principal categories are congenital malformations and tumours of a developmental nature. Distinction must be made between hereditary disorders which could recur in subsequent pregnancies, and those with a polygenic or environmental aetiology for which the risk of recurrence is not increased significantly.
Expression of Major Histocompatibility Antigens on Fetal and Placental Cells
Published in Gérard Chaouat, The Immunology of the Fetus, 2020
For both the Kd and Q10 genes, we did not observe any modification in the ratio between the amounts of the two splicing products.30 Therefore, molecular mechanisms ensuring the alternative splicing of their transcripts do not appear to be developmentally regulated. The two alternative spliced products of the Q7 and Q9 genes are expressed in equal amounts in all the tissues analyzed.22 During late embryogenesis, it was shown that the fetal liver and the visceral yolk sac (VYS) synthesize similar sets of serum proteins.31 We detected Q10 transcripts in the endodermal layer of the VYS (Figure 4) until Day 14 of gestation, though confirming in the DBA2 strain the results obtained by Stein et al.32 in the outbred mouse strain CD1. Additionally, we found that the Q10 gene was also expressed in the cardiac area until Day 13 of gestation.30 Therefore we concluded that the expression of the Q10 gene is not strictly associated with endodermal cells or tissues from endodermal, embryonic, or extra-embryonic origin, as it may have been hypothesized from the results previously obtained in VYS and liver. In situ hybridization on histological sections of different organs from the adult and the embryo are in progress and should help to define more accurately which cell type expresses the Q10 gene during development.
Clinical Presentations and Diagnostic Imaging of VACTERL Association
Published in Fetal and Pediatric Pathology, 2023
Gabriele Tonni, Çağla Koçak, Gianpaolo Grisolia, Giuseppe Rizzo, Edward Araujo Júnior, Heron Werner, Rodrigo Ruano, Waldo Sepulveda, Maria Paola Bonasoni, Mario Lituania
In 1996, a study carried out by Damian et al. [3] was the first to demonstrate a molecular basis for VACTERL association, consisting of a mitochondrial cytopathy characterized by an A-G point mutation at nucleotide position 3243 of mitochondrial (mt) DNA. This mtDNA mutation was discovered in 100% of the renal tissue in a female infant who died at 1 month as a consequence of multicystic dysplastic kidney disease (MCDKD) associated with renal failure. The Sonic hedgehog (Shh) gene programs the development and differentiation of target cells of the growing embryo in a concentration-dependent manner. As a morphogen, it helps orchestrate precise temporal and spatial events during embryogenesis. Specifically, in the absence of an Shh signal, GLI2 and GLI3 act as suppressors, while in the presence of an Shh signal GLI2 and GLI3 are activators of Shh on targeted genes. Defective Shh signaling causes multiple developmental anomalies in the murine model similar to those of VACTERL association [4]. The findings of familial cases and chromosomal abnormalities are considered nonrandom interactions, and therefore VACTERL is considered an association [5,6]. Human candidate gene sequencing has identified TRAP1 and ZIC3 as causative genes for VATER/VACTERL phenotypes and isolated anorectal malformation [7,8]. FOXF1 may also be involved, but without a significant key role [9]. In the case of congenital anomalies of the kidneys and urinary tract (CAKUT), especially presenting a wide range of renal anomalies, pathogenic variants have been identified in B9D1, FREM1, ZNF157, SP8, ACOT9, and TTLL11 [10].
Renal Yolk Sac Tumor Clinically Misdiagnosed as Nephroblastoma: A Case Report
Published in Fetal and Pediatric Pathology, 2023
Meng Zhu, Chengmao Xia, Jie Yang, Zhe Liu, Xiaowen Zhao, Yaling Li, Bin Liu, Yanli Yang, Yali She
Extragonadal germ cell tumors (EGGCTs) are tumors that originate in extragonadal anatomical locations without evidence of primary gonadal origin. EGGCT includes seminoma, embryonal carcinoma, mature/immature teratoma, yolk sac tumor, and choriocarcinoma. EGGCTs composed of two or more tissue types are called mixed germ cell tumors. In 1959, a Danish pathologist, Teilum [5] described the histological morphological characteristics of yolk sac tumor for the first time, clearly pointing out that yolk sac tumor belongs to germ cell tumor, and its pathological morphology and occurrence sites are diverse. Since the basic histological characteristics of yolk sac tumor are similar to the differentiation of yolk sac during embryonic development [6], the yolk sac tumor outside the gonad may be the result of incorrect capture of germ cell precursors during embryogenesis [3]. According to this theory, yolk sac tumor can occur at any site [7].
Developing a Reflexive, Anticipatory, and Deliberative Approach to Unanticipated Discoveries: Ethical Lessons from iBlastoids
Published in The American Journal of Bioethics, 2022
Rachel A. Ankeny, Megan J. Munsie, Joan Leach
In less than a week, a fertilized human egg develops from a single cell to a cluster of around 240 cells referred to as a blastocyst. Studying early stages of human development, including the various cell types in the blastocyst, has always been difficult. Animal models provide some insights but key differences in how embryos form and develop limit their relevance (Rossant and Tam 2017). While it is possible to study the cellular and molecular interplay underpinning blastocyst formation and implantation using donated human embryos, their use is limited due to technical, legal, and ethical concerns. Thus researchers have sought to generate models that recapitulate different aspects of early human development in order to shed light into this process. These models rely on human pluripotent stem cells–embryonic stem cells (ESC) or induced pluripotent stem cells (iPSC)–to explore the formation and development of human embryos (known as embryogenesis). While researchers have been able to use pluripotent stem cells to create 3-D structures in vitro that mimic how organs such as the eye, brain, kidney, and liver develop for many years (broadly termed “organoids,” which provides part of the etymology for the neologism “iBlastoid”) (Lancaster and Knoblich 2014), extending directed differentiation of pluripotent stem cells to mimic the earliest stages of human development has only been pursued in recent years.