Human placenta sample

Analysis of Biological Samples 14.8.8.1 Human Placenta Sample... 

T. Vo-Dinh, J. P. Alarie, R. W. Johnson, M. J. Sepaniak, and R. M. Santella, Evaluation of the fiber-optic antibody-based fluoroimmunosensor for DNS abducts in human placenta samples, Clin. Chem. 37, 532-535 (1991). 

Watts H J, Lowe G R and Pollard-Knight D V 1994 Optical biosensor for monitoring microbial cells Anal. Chem. 66 2465-70 Vo-Dinh T, Alarie J P, Johnson R W, Sepaniak M J and Santella R M 1991 Evaluation of the fiber-optic antibody-based fluoroimmunosensor for DNA adducts in human placenta samples Clin. Chem. 37 532-5... 

Human placenta sample was dried at 105°C to a constant weight and crumbled. A portion (5 g) was mineralized with 15 ml of 12 M nitric acid for 12 h at 1 lO C in a teflon bomb. After mineralization. 

Human placenta (20 g) was completely dried at 105°C, crumbled, and a portion (5 g) was minerahzed by treating with nitric acid (12 M, 15 ml) at 110°C in a Teflon bomb. After mineralization, the contents were evaporated to dryness and the residue was dissolved in 1.0 ml of distilled water (termed sample A). An aliquot (10 pi) was chromatographed on RP-18 using MeOH -f HjO + CH3COOH (25 15 2) as the mobile phase. The separated spots of the metals were visualized by spraying the... 

As a result of the transfer of CDDs through the placenta to the fetus, by breast milk to infants and young children, and by lifelong dietary intakes from the consumption of meat, milk and dairy products, and fish, CDDs are found to be widespread in the adipose tissue of members of the general population (Orban et al. 1994). Human adipose samples from the recent 1987 NHATS Study provide a representative sample of CDD body burden in the general U.S. population (see Section 5.5.1). The average concentration of 2,3,7,8-TCDD in the U.S. population was estimated to be 5.38 pg/g ( 6%). The 1987 survey data clearly... 

Goyer and Cherian (1992) measured cadmium, zinc and copper, and metallothionein content of human placentas from 55 uncomplicated, full-term deliveries. The mothers ages ranged from 22 to 39 years, mean 29 years. All were current nonsmokers, but 16 (30%) acknowledged smoking in the past. None were on medication apart from iron and vitamin supplements. For 43 it was the first delivery, for 9 the second, for 1 the third, and for 2 the fourth. Samples of maternal and fetal blood were not obtained. Metals were measured by atomic absorption spectrophotometry and metallothionein by a silver saturation method (Scheuhammer and Cherian 1986). The results are shown in Table 1. Zinc levels of placentas were almost the same as those in the Kuhnert et al. (1988) study, but copper levels were considerably lower. No other comparable measurements of metallothionein were found in the literature. There is a strongly positive correlation between... 

The placental interface between maternal and fetal blood is in the chorionic villus and consists of capillary endothelial cells and cytotrophoblasts. Human and rodent placentas are hemochorial, where fetal chorionic villi bathe in lacunae of maternal blood. However, they differ in that rat chorionic villi contain a second layer of cytotrophoblasts. Sampling of human placenta should be from multiple sites because of variation in maturity in different areas and foci of degeneration. 

Mobile phase M, = toluene-chloroform (50 1) A/j = benzene-methyl isopropylketone (50 1) Mi = methanol-water-acetic acid (50 30 4). Conditions Ascending technique, run 15 cm. layer thickness 0.25 mm, activation at 120°C for 30 min. Detection (a) metal dithizonates were self detected, (b) 5% aqueous copper sulfate solution for metal diethyidithiocarbamates and (c) 0.25% PAN [l-(2-pyridylazo)-2-naphthol solution) in methanol followed by exposure to ammonia vapors for metal ions. Remarks (1) Best separations on RP-18 with My (2) The extracts of complexes of metals originating from biological samples require careful protection from environmental contamination and (3) The developed TLC method was applied for analysing human placentas collected from patients of the obstetrics Clinic in Tychi (Poland) for Pb. Cd, Zn, Cu, Ni, Mn. and Co content. 

The only other human tissue that has been analyzed for various BP compounds is the human placenta. Using a LC-MS/MS method, levels of several BPs were determined in 16 placental samples of women residing in Granada, Spain (Vela-Soria et al. 2011). The metabolite of BP, 4-OH BP, was detected in 68.8 % of the placenta samples in the range of 0.6-1.2 ng/g of tissue. Further research is needed to determine if the placenta could be used to monitor levels of BP metabolites in human populations. 

The very same principle was applied by Suzuki et al. [19] for the purification of the placental insulin receptor, starting with a prepurified sample, obtained from a plasma membrane fraction of human placenta by a fractionation protocol including affinity chromatography on Sepharose-concanavalin A as the last step. The following purification step was carried out, using insulin bound to dextran (M 40000) as the biospecific, water-soluble carrier. After filtration of the dextran-insulin-receptor complex on an adequate gel and then dissociation by mild acidification, the insulin receptor was obtained in a purified form. This method permitted a 8700 fold purification, from crude plasma membrane and, even more remarkable, a 60-fold purification after the affinity chromatography step. 

The adult form of Gaucher disease (type I) is currently the only sphingolipid storage disease for which a causal therapy is available [33]. The patients are treated with a modified glucocerebrosidase from human placenta or a recombinant sample. The protein carbohydrates contain the targeting information for the mannose receptor on macrophages. 

No information is available as to whether w-hexane or its metabolites cross the placenta in humans. Transfer across the placenta has been demonstrated in rats for -hexane and two resulting metabolites, 2-hexanone and 2,5-hexanedione (Bus et al. 1979) no preferential distribution to the fetus was observed for either -hexane or the metabolites. Due to its relatively rapid metabolism, storage of -hexane in body fat does not appear to occur at air concentrations to which humans are exposed thus, there is unlikely to be mobilization of maternally stored -hexane upon pregnancy or lactation. -Hcxanc has been detected in samples of human breast milk (Pellizzari et al. 1982) however, -hexane was not quantified, nor was any attempt made to assess the subjects exposure. A human milk/blood partition coefficient of 2.10 (Fisher et al. 1997) indicates there would be preferential distribution to this compartment if significant absorption occurred however no pharmacokinetic experiments have been... 

Blount and Valentin-Blasini [259] detected perchlorate in all amniotic fluid samples (n = 48) tested, ranging from 0.057 to 0.71 pg/L with a geometric mean of 0.18 pg/L. No comparison data for perchlorate in AF were available in the scientific literature. The perchlorate levels previously reported for human urine and milk are an order of magnitude higher than the levels found in this group of 48 AF samples [233, 256]. Lower levels of perchlorate in human AF compared with human milk could result from low NIS expression in the placenta compared to the lactating breast [265]. 

PCDDs, PCDFs and PCBs are highly fat-soluble and accumulate in adipose tissue. They can also pass through the placenta and are excreted in human breast milk, resulting in exposure of the nursing infant (Table 8.4). The results from UK participants in a WHO inter-laboratory trial showed that the concentrations of PCDDs and PCDFs fell from 29-37 ng I-TEQ/kg milk fat in 1987-1988 to 21-24 ng I-TEQ/kg milk fat in 1993-94.44 Although PCBs were not analysed in 1987-1988, the concentrations in the 1993-94 milk samples were 10-12 ng I-TEQ milk fat. The concentrations were similar to those reported by other European countries and other participants in the WHO trial. 

Schecter et al. (1996b) recently presented data on the levels of CDDs and CDFs in human fetuses (8-14 weeks gestational age with placenta removed) and in placentas from women from the general population who had normal deliveries. On a lipid basis, the total TEQs (CDDs plus CDFs) in a pool of 14 placentas was 10.1 ng/kg half this amount (5. 3 ng/kg) was measured in a pool of 10 fetuses. In an analysis of 43 samples of human milk, Schecter et al. (1996b) found that the total concentration of CDDs and CDFs was 16.7 ng/kg (expressed as TEQ). The authors also calculated that the TEQ body burden for the pooled fetal tissue was 0.034 ng/kg body weight for pooled placentas, they calculated a total TEQ of... 

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