Protein amniotic fluid

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). 

Genetic tests are performed on a sample of blood, hair, skin, amniotic fluid (the fluid that surrounds a fetus during pregnancy), or other tissue. For example, a procedure called a buccal smear uses a small brush or cotton swab to collect a sample of cells from the inside surface of the cheek. The sample is sent to a laboratory where technicians look for specific changes in chromosomes, DNA, or proteins, depending on the suspected disorder. The laboratory reports the test results in writing to a person s doctor or genetic counselor. 

Human serum is relatively more characterised than other biological samples and as a result some information on various metal binding proteins exists in various reference books. However, in samples for which such information is not available most investigators have resorted to calibrating the column with proteins or molecules of known molecular masses. Sample types to which this approach has been applied include serum, milk, amniotic fluid, urine and tissue homogenates. Some of the applications of SEC are summarised in Table 1. 

Amniotic Fluid Cu, Fe and Zn GFAAS and Inununonephelometry Identification of proteins associated with the metals by immunonepheldmetry 39)... 

Steroids have been measured by GC-MS in umbilical cord blood, amniotic fluid, and infancy urine of affected infants, and almost no steroids are found [73]. Only traces of progesterone metabolites were detected. Serum samples from women carrying an LAH fetus have normal concentrations of progesterone metabolites, formed pla-centally, since this organ produces the hormone independently of the StAR protein mechanism. 

AMNIOTIC FLUID. Determination of estriol in amniotic fluid using the preceding procedure is somewhat different due to the fact that amniotic fluid contains protein, and it is more difficult to remove the steroids because of protein binding. 

FIGURE 7 Group B streptococcus infection-induced differential protein expression in nonhuman primate (A) and human (B) amniotic fluid samples by surface-enhanced laser desorption/ionization (SELDI-TOF MS) using normal-phase protein chip arrays. Spectrum from 2.5 to 15 kDa collected at 235 nm laser intensity. Detailed spectra show increased expression of the 3.5 and 10.8 kDa peaks between control and infected. Arrows indicate the unique peaks represented by polypeptides overexpressed in infection. 

These have been found in saliva, amniotic fluid, plasma, granulocytes, platelets, milk, and gastric juice, and it was suggested by Stenman (S8) that the R-protein in these different cells and fluids is a single microhetero-... 

Renal clearance of ciprofloxacin averages 300 179 mL/min in adults with normal renal function, and the drug is 16-43% bound to serum protein in vitro. It crosses the placenta and is distributed into the amniotic fluid in humans. The usual human dosage has not revealed evidence of harm to the fetus. 

Prenatal diagnosis of I-cell disease has been based on greatly reduced phosphotransferase activity (cf. Biochemical Perspectives section) and abnormal intracellular-extracellular distribution of lysosomal enzymes in cultured amni-otic fluid cells (Table 17-3).As indicated in Table 17-3, amniotic fluid cells secrete large amounts of lysosomal enzymes into the extracellular medium. Decreased levels of lysosomal enzymes in chorionic villi obtained by biopsy have also been observed in I-cell disease however, the characteristic secondary effect (i.e.,increased levels of lysosomal enzymes in the extracellular compartment) is only partially expressed or not expressed at all in chorionic villi, suggesting an alternative mechanism for the transport of lysosomal proteins. Although... 

Data from Parvathy et al. (1989) and Besley et al. (1990). Intracellular activities are expressed as nmol substrate cleaved/ h/mg cell protein. Extracellular activities are expressed as the activity secreted into the medium/24 h/mg cell protein. Activities in amniotic fluid are expressed as nmol/h/mg protein. 

AS can be studied in human or animal lung extracts as well as in the amniotic fluid (AF) where AS molecules are present [2,4-6]. Along with the biochemical, cytochemical and other techniques of AS investigation, very useful information can be derived from the model studies of lipid and protein/lipid monolayers at liquid substrates. These models provide important data about lung mechanics [e.g. 7-11]. 

The results on formation and stability of black foam films, on the first place those on bilayer foam films (NBF) (see Sections 3.4.1.2 and 3.4.4) have promoted the development of methods which enable lung maturity evaluation. The research on stability of amphiphile bilayers and probability for their observation in the grey foam films laid the grounds of the method for assessment of foetal lung maturity created by Exerowa et al. [20,24]. Cordova et al. [25] named it Exerowa Black Film Method. It involves formation of films from amniotic fluid to which 47% ethanol and 7-10 2 mol dm 3 NaCl are added [20,24]. In the presence of alcohol the surface tension of the solution is 29 mN m 1 and the adsorption of proteins from the amniotic fluid at the solution/air interface is suppressed, while that of phospholipids predominates. On introducing alcohol, the CMC increases [26], so that the phospholipids are present also as monomers in the solution. The electrolyte reduces the electrostatic disjoining pressure thus providing formation of black foam lipid films (see Sections 3.4.1.2 and 3.4.4). 

As it is well known [36,37], the natural lipid/protein mixtures (such as amniotic fluid) can undergo different phase transitions due to variation in temperature or composition. Of special importance for the natural bilayer lipid membranes is the so-called main phase transition between the lipid crystalline and gel states at which a melting of the hydrocarbon tails of the lipid molecules occurs. For example, it has been demonstrated [36] that there exists an upper limit of the gel phase content in membranes above which the membrane morphology and permeability change dramatically thus making the execution of the physiological functions of the membrane impossible. 

Detected in utero by examination of amniotic fluid cells at week 13 of pregnancy. Values are expressed as micromoles of p-nitrophenol formed per hour per miorogram of protein. 

The proteins most amenable to routine laboratory evaluation die those in blood, urine, CSF amniotic fluid, saliva, feces, and peritoneal or pleural fluids. With few exceptions, the proteins found in all of these are derived from blood plasma. The following discussion is limited to (1) the most abundant plasma proteins, (2) changes of their concentrations in the most accessible body fluids, and (3) a few of the analytical techniques used to measure them. 

Proteins in Amniotic Fluid, Saliva, Feces, and Peritoneal and Pleural Cavities... 

When pulmonary surfactant is present in amniotic fluid in sufficient concentrations, the fluid is able to form a highly stable surface film that can support bubbles. Other substances in the fluid, including proteins, bile salts, and salts of free fatty acids, are also capable of forming stable bubbles, but they can be removed from the film by ethanol, which competes with the other substrates for a position in the surface fihn. The test makes use of the principle that more surfactant activity is necessary to support a stable foam as the fraction of ethanol in the mixture is increased. Therefore a fixed volume of undiluted amniotic fluid is mixed with increasing volumes of ethanol, and the largest fraction of ethanol in which the amniotic fluid is stfll capable... 

Pryhuber GS, Hull WM, Fink I, McMahan MJ, Whit-sett JA. Ontogeny of surfactant proteins A and B in human amniotic fluid as indices of fetal lung maturity. Pediatr Res 1991 30 597-605. 

Wu CH, Mennuti MT, Mikhail G. Free and protein-bound steroids in amniotic fluid of midpregnancy. Am J Obstet Gynecol 1979 133 666-72. 

The answer is c. (Murray, pp 812-828. Scriver, pp 3-45. Sack, pp 167-180. Wilson, pp 395-421.) Any defect of the fetal skin may elevate the amniotic a-fetoprotein (AFP) level, causing a parallel rise of this substance in the maternal blood. Neural tube defects such as anencephaly or spina bifida elevate the AFP in amniotic fluid or maternal serum other causes of increased AFP include fetal kidney disease with leakage of fetal proteins... 

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