Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.1.7 (acetylcholinesterase)
28,390 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The synthesis of plasma proteins directed by mRNA from human brain tissues was studied by combining in vitro or in ovo translation of mRNAs with crossed immunoelectrophoresis of the mRNA-directed labeled polypeptides, followed by autoradiography of the washed plates. Poly(A)-containing mRNA was prepared from different developmental stages of fetal and postnatal human brain and also from primary glioblastomas and meningiomas. Several plasma protein-like polypeptides were identified in the autoradiographs by their migration coordinates in the two-dimensional gels, compared with immunoprecipitates formed by mature, unlabeled, stainable proteins. These included polypeptides migrating like Gc globulin, haptoglobin, fibrinogen, alpha-fetoprotein, transferrin, cholinesterase, and alpha 2-macroglobulin; other, yet unidentified plasma proteins, were also observed. In general, the synthesis of these plasma proteins appeared to be more pronounced in fetal and neoplastic brain tissues than in postnatal tissues. However, clear immunoprecipitates for some of these plasma proteins could also be detected in products directed by mRNA from particular regions of mature, normal brains, indicating that some synthesis of plasma proteins takes place in the human brain even as late as 40 years of age. mRNAs for several proteins were also identified in samples of neoplastic brain. mRNA for transferrin was identified in normal fetal and adult brain but not in either the glioblastomas or meningiomas studied. Microinjected Xenopus oocytes, in which post-translational processing occurs as well, were also used to translate fetal brain mRNA. Several plasma proteins could be detected in the translation products which were induced and stored in the oocytes. These included hemopexin, which could not be detected in the in vitro system. Others, such as cholinesterase, were found to be secreted by the oocytes. These findings indicate that different cell types in the human brain may produce and either store or secrete particular plasma proteins at defined stages in their development.
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PMID:Synthesis of plasma proteins in fetal, adult, and neoplastic human brain tissue. 242 74

A pilot project to detect neural tube defects (NTD) of the fetus by maternal serum alpha-fetoprotein (MSAFP) screening of women in early pregnancy was initiated in Tel Aviv in 1982 at the instigation of the Israel Ministry of Health. The program was designed to be an extension of routine pregnancy care, which in this city is provided in municipal family clinics that are attended by about 50% of pregnant women before the 20th week of pregnancy. Of these women, 89% complied with the program. Women with a MSAFP level above a cutoff point of 2.4 multiples of the median (MOM) were invited for an ultrasound examination of the fetus, without having to repeat the MSAFP test, thereby reducing maternal anxiety. This deviation from the usual test system protocol did not impair sensitivity (87%), or specificity of the test on its own (95.6%), or in combination with ultrasound examination of the fetus and alpha-fetoprotein and acetylcholinesterase testing of the amniotic fluid (99.9%). The program detected 13 fetuses with an NTD; there were two false-negative results and one false-positive. The predictive value of a positive test was 93%. Its effectiveness as a preventive measure was impaired by the fact that 50% of pregnant women did not attend the family clinic before the 20th gestational week. An educational program for professionals and for the public is contemplated in order to reduce this proportion. Only 50% of normal twin pregnancies had an elevated MSAFP. A check on compliance with other screening systems during the interview for MSAFP screening led to the detection and elective abortion of two fetuses with Tay-Sachs disease. MSAFP screening in Israel is cost-effective rather than cost-beneficial.
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PMID:Early pregnancy screening for neural tube defects in Israel. 242 75

Eight pregnancies with open neural tube defects were detected in 70 midtrimester patients referred for sonography and amniocentesis because of elevated maternal serum alpha-fetoprotein levels. Two cases of anencephaly were detected by sonography, aborted without amniocentesis, and confirmed by pathologic examination. Six cases of open spina bifida were detected through amniocentesis by elevation of alpha-fetoprotein and acetylcholinesterase levels. In only three of these six was the abnormality seen on sonography. All six pregnancies were terminated, and open spina bifida defects were confirmed on pathologic examination. Amniocentesis was 100% sensitive for diagnosis of open spina bifida, while sonography was only 50% sensitive. Our results indicate that, in patients with elevated serum alpha-fetoprotein and a normal fetal sonogram, amniocentesis should be performed to rule out open spina bifida.
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PMID:Midtrimester screening for open neural tube defects: correlation of sonography with amniocentesis results. 243 18

We describe a fetus with epidermolysis bullosa dystrophica and a fetus with aplasia cutis congenita who were normal by careful ultrasound examination but whose midtrimester amniotic fluids exhibited elevated concentrations of alpha-fetoprotein and presence of acetylcholinesterase. These cases show that serious fetal skin pathology can be a source of amniotic fluid acetylcholinesterase and elevated alpha-fetoprotein concentration and should be considered as part of the differential diagnosis of these amniotic fluid findings.
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PMID:The association of congenital skin disorders with acetylcholinesterase in amniotic fluid. 244 9

Anencephaly in twin B was accompanied by elevated amniotic fluid alpha-fetoprotein (AFP) and a positive acetylcholinesterase (AChE) band on gel electrophoresis in both twin sacs, although twin A was normal. AChE results did not help distinguish the false positive AFP in this set of twins, implying that AChE may diffuse transamniotically as has been previously postulated for AFP. In light of the low concordance rate for neural tube defects in twins, patient counselling in this situation must include the information that AFP and AChE may be falsely elevated in normal twin when the other twin has a neural tube defect.
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PMID:Biamnial elevated alpha-fetoprotein and positive acetylcholinesterase in twins, one with anencephaly. 244 77

Prenatal screening was carried out in Havana City, Cuba, as part of a National Medical Genetics Programme, in order to detect elevated alpha-fetoprotein concentration in maternal serum (MS-AFP). A total of 97,900 pregnant women between 15 and 19 weeks of pregnancy were tested from 1982 to 1985. A double-antibody-sandwich technique was used. 173 malformed fetuses were detected. Confirmation was by ultrasonography, elevated AFP values in a second serum sample and in amniotic fluid and acetylcholinesterase. No termination of a normal pregnancy occurred. The screening of all pregnancies is easy, economical and useful for detecting not only fetuses suffering from open Neural Tube Defects (NTDs) and other severe disorders but also pregnancies at risk of further complications.
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PMID:Prenatal diagnosis of neural tube defects by measurement of serum alpha-fetoprotein in Havana City. 244 78

During a 6-year period 19,647 consecutively received amniotic fluid samples were analyzed for the alpha-fetoprotein (AFP) concentration. In samples with an AFP concentration above the 95% upper normal limit the fraction of AFP non-reactive with concanavalin A (con A) was determined by crossed affinity immunoelectrophoresis. Of 436 samples from normal pregnancies with a moderate elevation of AFP (between the 95% limit and 2.5 times the median) the con A fraction was normal in 92 to 98% of the cases, depending on the gestational age. At significantly elevated AFP concentrations (above 2.5 times the median), the fractions were normal in 78% of the 50 cases with a normal outcome. In 80 of 89 cases of fetal malformations, abnormally low fractions were found, and in all 19 cases of abdominal wall defects and congenital nephrosis the fractions were low. No significant difference was found in the sensitivity for detection of fetal malformations by con A analysis compared to quantitative analysis for acetylcholinesterase (AChE). However, significantly more false positive results were found in normal pregnancies for the con A analysis compared to the AChE analysis. Both analyses performed significantly better than ultrasound scanning in terms of sensitivity. It is concluded that AChE is the test of choice in prenatal diagnosis of fetal neural tube defects. However, a sensitivity of 1.00 and a predictive value of a negative test of 1.00 were found for the con A analysis for fetal abdominal wall defects. The AchE analysis performed less well in this context.
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PMID:Con A non-reactive fractions of human amniotic fluid alpha-fetoprotein in prenatal diagnosis of fetal neural tube defects and fetal abdominal wall defects. Predictive values, sensitivity, and specificity, and comparison to acetylcholinesterase and ultrasound scanning. 245 43

Placental membrane anatomy was evaluated after delivery in 65 twin pregnancies undergoing genetic amniocentesis with amniotic fluid alpha-fetoprotein and acetylcholinesterase determinations when indicated. Each twin member in the 57 uncomplicated twin pregnancies was found to have an amniotic fluid alpha-fetoprotein concentration similar to that of singleton pregnancies of an equivalent gestational age. Eight twin pregnancies were found to be discordant for fetal anomalies associated with an elevated amniotic fluid alpha-fetoprotein and acetylcholinesterase level. The amniotic fluid alpha-fetoprotein concentration in the unaffected fetus in these eight cases was found to be dependent on placental membrane structure. Of the five discordant twin pregnancies with diamnionic-dichorionic placentas, all unaffected twins demonstrated an amniotic fluid alpha-fetoprotein concentration within the normal range for gestational age with a normal acetylcholinesterase level. In three twin pairs with diamnionic-monochorionic placentas, the unaffected twin member had significantly elevated amniotic fluid alpha-fetoprotein and acetylcholinesterase levels, which suggested diffusion of alpha-fetoprotein and acetylcholinesterase through the amnion-amnion interface.
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PMID:Amniotic fluid alpha-fetoprotein concentrations in twin gestations: dependence on placental membrane anatomy. 245 15

A case of an infant with aplasia cutis congenita, a fetus papyraceus, abnormal maternal serum alpha-fetoprotein (MSAFP), elevated amniotic alpha-fetoprotein, and positive amniotic acetylcholinesterase activity represents an uncommon abnormality. Such a case came to our attention as a result of MSAFP screening. The delivery of a neurologically intact infant in the presence of amniotic acetylcholinesterase activity is described.
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PMID:Increased amniotic acetylcholinesterase activity with a fetus papyraceus and aplasia cutis congenita. 245 23

Early identification of fetal abnormalities is possible as a result of improved ultrasound resolution, chorionic villus sampling, and early genetic amniocentesis. A potential advantage of early genetic amniocentesis over chorionic villus sampling is its ability to detect neural tube defects. We obtained 476 amniotic fluid samples between ten and 15 weeks' gestation and analyzed them for karyotype and alpha-fetoprotein (AFP); 142 were also tested for acetylcholinesterase. Amniotic fluid AFP levels rose to a peak at 12-13 weeks' gestation and then gradually declined, closely approximating the pattern in fetal blood. The rate of inconclusive acetylcholinesterase results (a faint but true band) was four times higher than that later in pregnancy (10.6 versus 2.46%, respectively). However, the rate of associated fetal congenital anomalies was lower than that later in pregnancy. Chromosomal abnormalities were detected in the study group, and the association with low amniotic fluid AFP in early genetic amniocentesis levels was identical to that further along in pregnancy. These data help establish normal values for AFP in early pregnancy. With AFP and cautious interpretation of acetylcholinesterase, early genetic amniocentesis can be used for neural tube defect detection.
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PMID:Amniotic fluid alpha-fetoprotein and acetylcholinesterase in early genetic amniocentesis. 246 1


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