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Discovery and research
Published in Peter S. Harper, The Evolution of Medical Genetics, 2019
Anencephaly and spina bifida, the most frequent forms of neural tube defect, have been a major challenge and topic for research by those in medical genetics since the 1950s. Rather than being a single isolated discovery, advances have come from a series of workers ranging into the allied fields of epidemiology, malformation pathology, paediatrics and nutrition. The exceptionally high frequency of the condition across much of Britain (not forgetting Ireland) by comparison with America and much of continental Europe, along with marked regional variations, prompted a search for environmental factors, but family studies, initially by Cedric Carter and Michael Laurence [13] in South Wales (Carter et al. 1968) and by Norman Nevin [26] in Belfast (Elwood and Nevin 1973), among others, showed that genetic factors were relevant too, though ruling out any clear mendelian pattern. John Edwards (1961), working with McKeown and Record in Lancelot Hogben's Birmingham unit, had already noted seasonal variation, while all studies found a marked association with deprivation and poor nutrition, the frequency being highest in the poorer parts of the country.
Prenatal diagnosis, antenatal screening and reproductive aspects of medical genetics
Published in Angus Clarke, Alex Murray, Julian Sampson, Harper's Practical Genetic Counselling, 2019
In general, these methods of prenatal diagnosis of neural tube defects have proved reliable and free from major problems. However, several points need to be borne in mind. There are a number of other causes of a raised serum AFP level (Box 9.4), including normal twin pregnancy. These other causes can often be distinguished by the level of acetylcholinesterase in amniotic fluid, which is specifically raised in open neural tube defects.Routine obstetric ultrasound scanning is an inadequate substitute for high-resolution ultrasonography performed by an expert, at the optimal gestation (usually at least 18 weeks).Pregnancies already known to be at high risk (before screening) must be considered separately from general population screening and the risks estimated appropriately.Any pregnancy terminated should have an expert fetal autopsy, since numerous syndromes associated with neural tube defects exist, some Mendelian, others chromosomal (see Chapter 14).
Epidemiology of Neural Tube Defects
Published in Michele Kiely, Reproductive and Perinatal Epidemiology, 2019
Neural tube defects include anencephalus (including craniorachischisis), spina bifida (including meningocele, myelocele and usually encephalocele) and iniencephaly. Few data specific to iniencephaly or encephalocele are available. Therefore attention will be focused on anencephalus and spina bifida. More evidence is available on isolated anencephalus than on spina bifida as investigators usually have greater confidence in the completeness of ascertainment of cases with anencephalus.
Polystyrene nanoplastics exposure caused defective neural tube morphogenesis through caveolae-mediated endocytosis and faulty apoptosis
Published in Nanotoxicology, 2021
Jia-hui Nie, Yao Shen, Mohamed Roshdy, Xin Cheng, Guang Wang, Xuesong Yang
The nervous system originates from embryonic neurulation via the formation of neural primordia (Karfunkel 1974), which is a complex multistep event that is implicated in the accurately spatiotemporal regulation of gene expression (Smith and Schoenwolf 1997; Tanabe and Jessell 1996). In this study, we discovered that early chick embryos exposed to PS-NPs exhibited a high frequency of neural tube failure at both the cranial and trunk levels in addition to other developmental abnormalities (Figure 4). This finding implies that PS-NP-induced neural developmental abnormalities occur during gastrulation. Of course, one of the important reasons is that neurulation initiates at a very early stage; thus, neural precursors in the developing neural tube are also exposed to PS-NPs for a long period of time. Additionally, the neural tube undergoes dramatic morphological changes that are also extremely vulnerable to external environmental factors. Cecconi et al. reported that the etiology of neural tube defects was stalwartly multifactorial with both environmental and genetic factors and involved in numerous pathological mechanisms, including faulty cell death during neurulation (Cecconi, Piacentini, and Fimia 2008).
Concordance between creatinine- and cystatin C-based eGFR in clinical practice
Published in Scandinavian Journal of Clinical and Laboratory Investigation, 2021
Emil den Bakker, Marin Musters, Isabelle Hubeek, Joanna A. E. van Wijk, Reinoud J. B. J. Gemke, Arend Bokenkamp
In the cases with low agreement a majority of 130 (62.5%) were due to higher FAScys compared to FASage. This is visualized in Figure 1, where the intersection lines represent 40% of the respective axes. We compared eGFR, BMI, sex, age, diagnosis group and glucocorticosteroid use between measurements with high vs. low agreement (Table 1). Patients with low agreement were significantly younger than those with high agreement, while BMI z-score and mean eGFR did not differ between the groups. Among the diagnoses only neural tube defects were significantly more frequent in the low agreement group. In this group, low agreement was due to high FASage compared to FAScys as shown in Figure 2(a). Agreement was much higher in nephritis patients (Figure 2(b)) and measurements with low agreement were distributed evenly.
Adherence to iron prophylactic therapy during pregnancy in an urban regional hospital in South Africa
Published in South African Family Practice, 2019
Princess Z Mkhize, T Naicker, OA Onyangunga, J Moodley
Iron is necessary for haemoglobin synthesis and its requirement increases during pregnancy, therefore women receive prophylactic iron and folic acid supplementation throughout pregnancy and the puerperium.1,3,6 Folic acid prevents neural tube defects and macrocytic anaemia, especially when initiated prior to conception and continued in early pregnancy during neural system development.7 In pregnancy, the physiological demands of a growing foetus, changes in red cell volume, vomiting and increasing nutrient demand support the need for iron supplementation.8 A decrease in iron stores during pregnancy is accompanied by a significant rise in the reticulocyte count (RC) that eventuates in an increase in erythropoiesis, therefore RC is used to monitor progress after iron supplementation.9