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Carrier Screening For Inherited Genetic Conditions
Published in Vincenzo Berghella, Obstetric Evidence Based Guidelines, 2022
Whitney Bender, Lorraine Dugoff
Alpha-thalassemia results from a gene deletion of two or more copies of the four alpha-globin genes on chromosome 16. It is common among individuals of Southeast Asian, African, West Indian, and Mediterranean ancestry. Deletion of two genes, alpha-thalassemia trait, causes a mild hemolytic anemia. The deletions may occur on the same chromosome (cis aa/-) or on two different chromosomes (trans a-/a-). Individuals of Southeast Asian descent are more likely to carry the cis configuration compared to their African counterparts. Individuals with alpha-thalassemia trait are at increased risk for having a child with a more severe form of alpha-thalassemia. Hemoglobin H disease is caused by the deletion of three alpha-globin genes. Affected individuals have mild to moderate hemolytic anemia. Alpha-thalassemia major (Hb Bart disease) results from the absence of functional alpha-globin genes. Fetal hydrops and intrauterine fetal demise is the expected outcome in these cases due to the inability to produce functional HbF. Hemoglobin Bart disease does not usually occur in fetuses of alpha-thalassemia carriers of African origin, since individuals of African descent usually have the trans-configuration genotype. See Chap. 14 in Maternal-Fetal Medicine Evidence Based Guidelines.
Testicular Cancer
Published in Karl H. Pang, Nadir I. Osman, James W.F. Catto, Christopher R. Chapple, Basic Urological Sciences, 2021
Selma Masic, Abhishek Srivastava, Alexander Kutikov
Schiller–Duval bodies (pathognomonic):Cellular structures resembling a glomerulus.Contain AFP and alpha 1-antitrypsin.Identified in 50% of the tumours.
Second-trimester screening for fetal abnormalities
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
Jolene C. Muscat, Anthony M. Vintzileos
Alpha-fetoprotein (AFP) is a normal fetal protein found in high concentrations in the fetal serum. It is present in amniotic fluid in normal pregnancies, presumably reaching the fluid through excretion in the fetal urine. From the amniotic fluid, AFP diffuses across the fetal membranes and can be detected in the maternal serum beginning at approximately 12 weeks of gestation (2). In cases of fetal anencephaly or open spina bifida, increased levels of AFP reach the amniotic fluid secondary to the concentration gradient from fetal serum to amniotic fluid. This increased AFP concentration can then be detected in the maternal serum. Ventral wall defects (i.e., omphalocele or gastroschisis) can also result in similar elevations in MSAFP through this same mechanism. Other causes of elevated MSAFP are listed in Table 1.
Correlation between elevated maternal serum alpha-fetoprotein and ischemic placental disease: a retrospective cohort study
Published in Clinical and Experimental Hypertension, 2023
Xiaoqing Dai, Huimin Zhang, Bin Wu, Wenwen Ning, Yijie Chen, Yiming Chen
Maternal serum alpha-fetoprotein (AFP) is a glycoprotein composed of 590 amino acids that is mainly produced by fetal liver cells and the soft yolk sac during pregnancy (1). AFP synthesis by the proliferating fetal liver increases through 20 weeks gestation, after which synthesis remains fairly constant until 30–32 week gestation, then decreases until birth (2). During pregnancy, AFP is excreted into fetal urine and diffuses into maternal serum through the placenta or fetal membranes. Adverse pregnancy reactions, such as fetal open neural tube defect (ONTD), congenital nephrotic syndrome, placental injury, serum, or cerebrospinal fluid leakage, and gastrointestinal tract damage, result in rapid protein filtration, placental channel changes, or obstruction, and maternal serum AFP levels increase (3,4).
Long-Term Alpha-Lipoic Acid (ALA) Antioxidant Therapy Reduces Damage in the Cardiovascular System of Streptozotocin-Induced Diabetic Rats
Published in Journal of Dietary Supplements, 2023
Cristiane Simões Coelho Britto Ramos, Vivian Alves Pereira da Silva, Lanna Beatriz Neves Silva Corrêa, Renato de Souza Abboud, Gilson Teles Boaventura, Mauricio Alves Chagas
Alpha-lipoic acid (ALA) is a potent antioxidant. In fact, it is one of the most effective agents in reducing the damage caused by reactive oxygen species (ROS), and is usually found in small amounts in meat and vegetables (24,25). In the tissues, it is readily distributed and rapidly converted into its most active form: dihydrolipoic acid (26). ALA is a nutraceutical whose beneficial effect has been related to its ability to repair cellular oxidative damage in various body tissues (27,28), in addition to its anti-inflammatory effect (29). Owing to its small size and high lipophilicity, it easily crosses biological membranes and inhibits the deleterious effect of reactive oxygen species, thus reducing the oxidation of cellular components (30). It has antioxidant activity in lipo and water-soluble media, either in its oxidized or reduced form (31).
Alpha-1 antitrypsin deficiency: current therapy and emerging targets
Published in Expert Review of Respiratory Medicine, 2023
Oisín F. McElvaney, Daniel D. Fraughen, Oliver J. McElvaney, Tomás P. Carroll, Noel G. McElvaney
Alpha-1 antitrypsin (AAT) is a glycosylated protein produced mainly in the liver [1]. It first came to prominence in the 1960s when Laurell and Eriksson, in Malmo, Sweden discovered that a lack of this protein was associated with an increased risk for emphysema [2]. Further work showed that the major role of AAT in the lung was to inhibit neutrophil elastase (NE), an omnivorous protease produced by neutrophils, which is capable of digesting many structural components of the lung in addition to proteins involved in immunity and inflammation [3]. This led to the development of the protease-antiprotease theory of emphysema in which the antiprotease protection in the lung, mainly provided by AAT, is markedly reduced, either functionally, in theory by cigarette smoke, or quantitatively by AAT deficiency (AATD), leading to the unopposed action of NE and subsequent lung destruction [4–6]. Further work elucidated the liver disease associated with AATD [7] and determined that the major cause of low levels of AAT in the blood and lungs of people with AATD was due to polymerization and retention of misfolded AAT protein in the liver [8,9].