China
Africa
Explore chapters and articles related to this topic
Introduction
Published in Nilanjana Maulik, Personalized Nutrition as Medical Therapy for High-Risk Diseases, 2020
Scientists have determined that genetic expression is influenced by ‘endogenous and exogenous factors and therefore particularly prone to nutritional imprinting’ (Ruemmele and Garnier-Lengline 2012). Moreover, nutrition and genes interact in two different ways. The term ‘nutrigenomics,’ where the impact of nutritional factors on gene regulation and expression is considered. The other way, ‘nutrigenetics,’ examines the influence genetic variation has on, or predetermines, nutritional requirements. Both interactions are important considerations for designing a personalized nutrition concept.
Estrogens and Immunity: Long-Term Consequences of Neonatal Imprinting of the Immune System by Diethylstilbestrol
Published in Takao Mori, Hiroshi Nagasawa, Toxicity of Hormones in Perinatal Life, 2020
Classic teratology has concentrated on morphological alterations induced by developmental insults. The long-term effects of DES on the endocrine and immune systems demonstrate that more subtle although permanent alterations not evident as gross organ malformations may be induced during development. Such functional teratogenesis may pass unattended due to the wide biological variation in the response of individuals in biological assays. With the increasing awareness of the importance of the immune system in the defense against infections and tumors, the possible role of perinatal exposure to agents with imprinting activity on the immune system, as demonstrated for DES, should be carefully considered. One of the major unresolved problems in immunology today is a proper understanding of the tolerance phenomenon, i.e., the lack of reactivity towards self. Tolerance induction is mainly a characteristic of the immature immune system and can be regarded as imprinting by self components. Tolerance is the central issue of immune deviations such as allergy and autoimmune disease. The demonstration that exogenous factors can have strong imprinting effects on the immature immune system emphasizes that similar effects should not be excluded in the search for an etiology of immune disturbances manifested later in life.
Genetics
Published in Rachel U Sidwell, Mike A Thomson, Concise Paediatrics, 2020
Rachel U Sidwell, Mike A Thomson
Genomic imprinting is the differential activation of genes depending on which parent they were inherited from. Examples are Prader–Willi, Angelman syndrome and Beckwith–Wiedemann syndromes.
Original antigen sin and COVID-19: implications for seasonal vaccination
Published in Expert Opinion on Biological Therapy, 2022
Antigenic sin has been observed in a variety of species [12–14]. Mice immunized sequentially with two related influenza virus antigens produce a secondary antibody response with two different specificities [15]. The amplitude of these responses may vary according to a variety of factors that, in some cases, may suggest immune imprinting. However, the very existence of original antigenic sin remains controversial. Sequential infection of ferrets with serologically related influenza viruses led to a marked increase in the number of antibody molecules reacting with the first virus and avidity was inversely related to infection [16]. T cells were shown to modulate this response by either enhancing or suppressing antibody secretion by B-memory cells, and this response changes with time [17]. Although initial work focused on influenza, it is now known that immune imprinting occurs after exposure to rotavirus, respiratory syncytial virus, cytomegalovirus, and seasonal coronaviruses, although the frequency of these reactions is unknown [18–21].
Establishing perinatal and neonatal features of Prader-Willi syndrome for efficient diagnosis and outcomes
Published in Expert Opinion on Orphan Drugs, 2020
Lili Yang, Bo Ma, Shujiong Mao, Qiong Zhou, Chaochun Zou
Some studies have revealed that the application of human-assisted reproductive technologies (ART) is correlated with increased incidence of imprinting disorders including PWS [33–36]. Hattori et al. studied 931 patients with imprinting disorders including 520 PWS confirmed the association of imprinting disorders and ART [33]. They found that the rate of DNA methylation errors in ART-PWS patients was significantly higher than that of spontaneously conceived (Sp)-PWS patients when maternal age was ≤37 years, while the rate of UPD(15)mat in ART-PWS patients was significantly increased compared with that in Sp-PWS patients with a maternal age ≥ 38 years [33]. Their results suggested that the increasing incidence of ART-PWS might be affected not only by maternal age but also DNA methylation altered by ART [33]. However, another review on eight epidemiological studies revealed no significant associations between the incidence of PWS and ART including in vitro fertilization (IVF) or intracytoplasmic sperm injection [37]. A large Danish National IVF cohort study on 6052 IVF children revealed no indications of an increased risk of imprinting diseases after IVF [38]. Therefore, ART as a risk factor for PWS is still conflicting and needs further study.
Design, synthesis and characterization of enzyme-analogue-built polymer catalysts as artificial hydrolases
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2019
Divya Mathew, Benny Thomas, Karakkattu Subrahmanian Devaky
p-nitrophenol [13] from N-carbobenzoxy-L-tyrosine p-nitrophenyl ester, nitrophenyl esters of acetic acid, hydrocinnamic acid and carbobenzoxyglycine. Even though biocatalysts increase the rate to several orders and are highly specific, they suffer from several limitations, for instance, incompatibility with organic solvents, extreme pH, and elevated temperatures. The developing technique of molecular imprinting advances a promising and advantageous alternative to overcome the problems associated with biomolecules. The most archaic and extensive efforts toward MIP catalysts have used the “catalytic triad” motif of serine, histidine, and aspartic acid found in the family of serine proteases to serve as a model [14]. Chymotrypsin, an enzyme with a well-recognized catalytic mechanism has long been a model of choice for MIP catalysts. Rate enhancements by MIPs, however, have yet to reach the catalytic rate of this enzyme, which enhances the rate of the hydrolysis of peptide bonds by a factor of ∼1010.