Amniotic fluid

Some data on specific organic acids in amniotic fluid near term were given by Raiha (1963), who used enzymic and colorimetric methods to determine lactate, pyruvate, 2-oxoglutarate and citrate concentrations in an investigation of neonatal metabolic acidosis. Silicic acid chromatography was also used to demonstrate the presence of citric, lactic and pyruvic acids. Typical concentrations observed were lactate 75.69 21.29 mg (100 ml) pyruvate 0.82 0.40 mg (100 ml) citrate 5.55 1.27 mg (100 ml) and 2-oxoglutarate 0.74 0.33 mg (100 ml) (all near-term). 

Acid Concentration (/imol 1 Early gestaton n = 35) ) Late gestation (n = 21)  

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In an interesting medical application, the formation of a stable black foam film from amniotic fluid can be used as an assessment of fetal lung maturity [206]. 

Purified by a [anti-human amniotic fluid-TIMP]-Sepharose immuno-affinity column eluted with 50mM glycine/HCl pH 3.0 buffer that is 0.5M in NaCl then by gel film [Cawston et al. Biochem J 238 677 1986]. 

Amnion-flusaigkelt, /. amniotic fluid. saure, /. amniotic acid (allantoin). wasaer, n. amniotic fluid. 

Hyperstimulation of the uterus during labor may lead to uterine Many with marked impairment of the uteroplacental blood flow, uterine rupture, cervical rupture, amniotic fluid embolism, and trauma to the infant. Overstimulation of the uterus is dangerousto both the fetusand the mother and may occur even when the drug is administered properly in a uterus that is hypersensitive to oxytocin. 

If the genetic lesion is understood and a specific probe is available, prenatal diagnosis is possible. DNA from cells collected from as little as 10 mL of amniotic fluid (or by chorionic villus biopsy) can be analyzed by Southern blot transfer. A fetus with the restriction pattern AA in Figure 40-10 does not have sickle cell disease, nor is it a carrier. A fetus with the SS pattern will develop the disease. Probes are now available for this type of analysis of many genetic diseases. 

Biochemical Analysis> The second principal use of cultured amniotic fluid cells is to determine the biochemical status of the fetus. Again, it should be pointed out that the individual biochemical disorders are quite low in incidence, but many of them are very serious in their manifestations and can occur with relatively high frequencies in specific families. If two parents are carriers of a gene for an autosomal recessive condition, then the risk to each child of having the disorder is 25%. 

There are important methodologic considerations which apply to the use of cultured amniotic fluid cells for the detection of biochemical disorders. The first is that the enzymes which can be sampled are those which are usually present in fibroblasts or fibroblast-like cells. Therefore, conditions such as phenylketonuria and glycogen storage disease type I, which are associated with deficiencies of enzymes present only in liver and kidney, are not amenable to this approach. The same also pertains to enzyme deficiencies affecting other specific tissues. 

The one present exception to this is hlstidase, an enzyme characteristic of epithelial cells. In this instance, it has been possible to select clones of epithelioid cells from the mixed cell population of the amniotic fluid cell cultures and to analyse them for this enzyme (55). 

The second methodologic consideration relates to the type of cells which are used as controls for the biochemical determinations. While less a problem now, there was a tendency in some early investigations to use cultured skin fibroblasts or similar cells as controls for the cultured amniotic fluid cells. 

It has been demonstrated that such controls are not valid and that there may be significant differences in enzyme concentrations between two cell types (56). For this reason, normal amniotic fluid cells themselves must be used as controls for amniotic fluid cell cultures being subjected to enzymologic inves t igat ion. 

Gerble, A. B. Melancon, S. B. Ryan, C. and Nadler, H. L. "Cultivated Eplthellal-Llke Cells and Fibroblasts from Amniotic Fluid Their Relationship to Enzymatic and Cytologic Analysis". Am. J. Obstet. Gynecol., (1972), 114, 314-320. 

Unfortunately, Perkin-Elmer whcTiras produced this instrument has built the instrument for the purpose of measuring bilirubin in amniotic fluid. As a result, the instriment does not read above a level of approximately 2 mg/100 ml. Therefore, it is necessary to dilute the serum from newborns in order to be read in this instrument. However, if one standardizes by making a 1 to 5 dilution of all newborn serum, one can use this method for screening purposes. One looks forward to the further development of this instrument so that readings can be made over a wide range. 

Still widely used is the method of scanning for bilirubin in amniotic fluid. A scan is run for some distance before and after 450 nm. From the baseline drawn between 2 points (e.g. 

Recently, in a study of the various methods for doing proteins in amniotic fluid it was noted that values ranging up to 12% have been reported in literature. What was being measured in these cases was the turbidity and the presence of hemolysis in amniotic fluid. When the Bloor s reagent extract is applied, substantially lower and more consistent values were obtained (47). 

Dubin, A. Application of multi-wavelength spectroscopy to analysis of amniotic fluid bilirubin, in Amniotic Fluid. Natelson, S. Scommegna, A. and Epstein, M. D., ed. John Wiley, N. Y. (1974) pp. 191 - 197. 

Lind, T. and Hytten, F. E. "Relation of Amniotic Fluid Volume to Fetal Weight in the First Half of Pregnancy". 

Later in intra-uterine life, the human infant is susceptible to early chemical prompting, but again the affector route is not known with certainty. Neonatal discrimination in favour of familiar (maternal) amniotic fluid is demonstrable, suggesting that the foetus already has active chemosensory capacities (Schaal, 1998). Smell and taste are operative in the near full-term foetus since it shows detection of about 120 mg/day maternal intake of anethole (as anise condiments) within a few days before parturition this exposure induced subsequent preferential responses by babies to anethole (Schaal et ai, 2000). The human neonate is not likely to have its organ as a fully functioning chemosensor,... 

Levy F. and Poindron P. (1987). The importance of amniotic fluid for the establishment of maternal behavior in experienced and inexperienced ewes. Anim Behav 35, 1188-1192. 

Schaal B., Marlier L. and Soussignan R. (1998). Olfactory function in the human fetus evidence from selective neonatal responsiveness to the odor of amniotic fluid. Behav Neurosci 112, 1438-1449. 

Pulmonary embolism Amniotic fluid embolism Tumor embolism... 

Birth asphyxia Hypothermia Meconium or amniotic fluid aspiration Necrotizing enterocolitis Respiratory distress syndrome Shock Obstetrics Abortion... 

Pesticides accumulate in fetal cells and reproductive organs in mammals, birds, and fish due to biochemical processes. This is noted especially often for OCPs, which were observed in large amounts (up to 6.8 mg/kg) in, for example, the sexual organs of hares, rabbits, pheasants, green-winged teals, and in white-eyed and red-headed ducks. They were found in animal embryos, as well as in black thrush eggs and in pheasant embryos and amniotic fluid (up to 73.0 mg/kg) [3]. 

Manya, H., et al. (2000). Comparative study of the asparagine-linked sugar chains of human lipocalin-type prostaglandin D synthase purified from urine and amniotic fluid, and recombinantly expressed in Chinese hamster ovary cells. 

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