HYPERVITAMINOSIS A-INDUCED CENTRAL NERVOUS SYSTEM DEFECTS
In this investigation the effects of excess vitamin A administration during the early embryonic period were studied. Intramuscular injection of a single dose of 15000,20000 or 25000 IU/kg vitamin A to pregnant Balb/c strain mice on either day 7,8,9 or 10 of gestation (vaginal plug= day 0 of gestation) produced major malformations in the central nervous system (CNS) including exencephaly, hydrocephalus, microcephalia, spina bifid a and myelocystocele and also a few other defects such as limb malformations. The incidence and severity of these malformations was positively correlated with the dosage and time of exposure. Among experimental groups, the most effective dose of vitamin A which produced a high incidence of CNS defects was 25000 IU/kg injected on day 8 of gestation (35%) compared to the control group (0%). Histological studies on 18 day old experimental fetuses revealed spina bifid a with and/or without spinal cord defect. These studies showed excessive embryonic cell death localized in the neural tube region following vitamin A exposure. In conclusion, excess vitamin A exposure in the early days and critical periods of development may interfere with certain developmental phenomena, resulting in various detectable CNS defects among newborn infants.
in this investigation the effects of excess vitamin a administration during the early embryonic period were studied. intramuscular injection of a single dose of 15000,20000 or 25000 iu/kg vitamin a to pregnant balb/c strain mice on either day 7,8,9 or 10 of gestation (vaginal plug= day 0 of gestation) produced major malformations in the central nervous system (cns) including exencephaly, hydroc...متن کامل
Besides being a metabolite of nucleotides like ATP, adenosine is a mediator of neuronal function in the central nervous system. Its actions are mediated by at least three extracellular receptors. In this review different aspects of adenosine such as biosynthesis, release, inactivation and its receptors are discussed. It also covers pre- and postsynaptic effects as well as postreceptor mecha...متن کامل
Listeriosis is one of the CNS inflammatory diseases which is happened majority in the form of sporadic. Listeriosis is ingested with the food. Infection occurrence in an exposed person depends on the number of organisms ingested, the virulence of the organisms strain and the individual condition. It is known that Listeriosis has decisive importance as an infection which the cellular immunodefen...متن کامل
objective primary central nervous system lymphoma (pcnsl) is an extremely rare condition in childhood. we report the first case of pcnsl in a child in iran. clinical presentation a nine-year-old boy was referred to mofid hospital with the history of headache of four months and seizure of 2 months duration. magnetic resonance imaging of the brain revealed a hyper-intense lesion in left fronto-pa...متن کامل
Linezolid Induced Twice Pure Red Cell Aplasia in a Patient with Central Nervous System Infection after Allogeneic Stem Cell Transplantation
Linezolid (LZD), severed as the ﬁrst oxazolidinone antibiotic, was active against multidrug-resistant gram-positive strains. LZD can induce thrombocytopenia, anemia and leukocytopenia. Currently, reports on pure red cell aplasia (PRCA) cases induced by LZD are relatively rare [4-7]. In this paper, we reported a patient with PRCA twice induced by LZD. A 37-year-old man was diagnosed with myelody...متن کامل
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دوره 12 شماره 3
صفحات 279- 283
تاریخ انتشار 1998-11
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