Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0728731 (prematurity)
 7,134 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Research related to maternal-child transmission of human immunodeficiency virus (HIV) has been advanced by standardization of case definitions and transmission rate calculation methodologies as well as enhanced diagnostic options for detecting infant HIV-1 infection. Standardization guidelines have yielded vertical transmission rate estimates of 25-30% in developing countries and 14-25% in developed countries. Mathematical modeling suggests that 95% of infant infections occur later than the last 2 months before delivery. Serial polymerase chain reaction evaluation has identified a 7.7% risk of in utero transmission, a 17.6% risk of combined in utero and intrapartum transmission, and a 4.9% incidence of late postnatal transmission. The risk of transmission through breast feeding has been estimated at 14%, with increases with longer durations. Advanced maternal clinical HIV status, primary infection, decreased maternal cell-mediated immunity, placentitis, ascending genital infection during the peripartum period, and syncytium-inducing HIV-1 strains have been associated with higher rates of maternal-child transmission. Prematurity, lack of cellular immunity, and vitamin A deficiency may be infant risk factors. The finding in an AIDS Clinical Trial Group that zidovudine (AZT) treatment was associated with a 67.5% reduction in risk has prompted widespread use of this regimen in developed countries; however, AZT is expensive and logistically difficult to administer in most developing country contexts. Randomized clinical trials currently underway are assessing the benefits of cesarean section delivery, postpartum HIV-specific immunoglobulin administration to infants, avoidance of breast feeding or early weaning, and antenatal maternal vitamin A administration. Selected intervention strategies should be regionally designed to take into account variations in viral, host, and obstetric factors.
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PMID:Mother-to-child transmission of human immunodeficiency virus type 1. 902 9

The purpose of this review is to give an update of the recent progress in research on erythropoietin (Epo), the hormone that regulates red blood cell production. Epo is a glycoprotein with a molecular mass of approx 30 kDa, which circulates in plasma of the human with 165 amino acids with three N-linked and one O-linked acidic oligosaccharide side chains in the molecule. Both the alpha (39% CHO) and beta (24% CHO) forms are available for clinical use, and there does not appear to be any difference in the pharmacokinetics of these two forms of Epo. Radioimmunoassays and enzyme-linked immunoabsorbant (ELISA) assays are available in a kit form. Serum levels of Epo in normal human subjects range between 1 and 27 mmu/ml or approx 5 pmol/l. It seems clear that the cells in the adult mammalian kidney which produce Epo are the interstitial cells in the peritubular capillary bed and the perivenous hepatocytes in the liver. Expression of the human Epo gene sequences that direct expression in the kidney are located 6-14 kilobases 5' to the gene; whereas the sequences that control hepatocyte-specific expression are located within 0.7 KS to the 3'-flanking region and 0.5 KS to the 5'-flanking region. The signal transduction pathways postulated to be involved in the expression of Epo are: kinases A, G and C; both a constitutive factor and a second hypoxia-inducible factor-1 (HIF-1) located in the 5' end of an hypoxia inducible enhancer region of the Epo gene; and reactive oxygen species. The primary target cell in the bone marrow acted on by Epo is the colony-forming unit erythroid (CFU-E) which has the highest number of Epo receptors. It has been postulated that Epo decreases the rate which Epo-dependent progenitor cells undergo programed cell death (apoptosis). There are two major signal transduction pathways activated by the Epo receptor: the JAK2-STAT5 pathway and the ras pathway. Both pathways involve tyrosine phosphorylation. The approved clinical uses of Epo are the anemias associated with end-stage renal disease, cancer chemotherapeutic agents, and patients with HIV infection receiving AZT. Other anemias reported to respond to Epo therapy are anemia of prematurity, rheumatoid arthritis, and myelodysplasia. Other uses of Epo under investigation are in perioperative surgery and preoperative autologous blood donation.
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PMID:Erythropoietin: physiologic and pharmacologic aspects. 940 40

An increasing number of HIV-infected women of childbearing age are initiating antiretroviral therapy (ART) worldwide. This review aims to discuss updated data of the eligible ART regimens and their role in inducing birth defects in utero. Zidovudine and lamivudine plus a non-nucleoside reverse-transcriptase inhibitor or protease inhibitor (PI) is the first-line regimen applied. The role of zidovudine exposition monotherapy or associated with other ART in inducing birth defects remains inconclusive. The main organ systems involved are genitourinary and cardiovascular. For HIV-infected pregnant women, World Health Organization (WHO) guidelines up to 2010 recommend the same group of drugs that are prescribed to nonpregnant women. The exception is efavirenz, which has been associated with an increase in the risk of teratogenicity. Increased rates of birth defects were found in large cohorts and computational studies conducted recently in infants exposed to efavirenz-containing regimens. The combination of zidovudine and lamivudine and lopinavir/ritonavir is one of the most used ART regimens for prevention of mother-to-child-transmission. Conflicting data about the role of PI exposure in utero and birth defects have been reported. However, a reduced number of studies evaluating the role of PI in inducing birth defects in women are available. An association between prematurity and PI exposure in pregnancy was extensively described. Some questions arise due to the tendency of initiating ART early in the life of HIV-infected individuals or those at risk of infection. Longtime exposure to different ART regimens and the potential effect of birth-defect induction in pregnancy are not completely understood. Developing regions harbor the highest numbers of women of reproductive age exposed to ART. Most of the largest and expressive data come from developed countries, and could not be sufficiently representative of pregnant women living in developing countries.
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PMID:Antiretroviral therapy, pregnancy, and birth defects: a discussion on the updated data. 2394 59