Cord Blood Serum Samples Research Articles

Serum 25-Hydroxyvitamin D in Early Childhood Is Nonlinearly Associated with Allergy

Background: Vitamin D has several immunological functions. Data on the relation of vitamin D status and allergy are controversial. Methods: We investigated the association between serum concentrations of 25-hydroxyvitamin D (25-OHD) and allergy in childhood. The study population (n = 819) was part of a randomized, double-blind, placebo-controlled trial where the mothers of offspring with a high risk for allergy received a mixture of probiotics (or placebo) for the last 4 weeks of pregnancy, and the child received this from birth to 6 months. Study subjects were followed for the emergence of sensitization and allergic symptoms for a period of 5 years, with medical examinations at the ages of 3 and 6 months, 2 and 5 years and also in the event of allergic symptoms. Levels of 25-OHD were measured in umbilical cord blood (UCB) samples (n = 724) and serum samples drawn at the age of 2 years (n = 369); the data were categorized into tertiles (T1-T3) and quartiles (Q1-Q4). The relation between 25-OHD levels and sensitization and allergy was analyzed with multivariable logistic regression analysis. Results: 25-OHD levels in T2 in UCB were associated with a higher risk for sensitization by the age of 2 years and allergic disorders by the age of 5 years. In the serum samples, at the age of 2 years, 25-OHD levels in Q3 were associated with a higher risk of sensitization and IgE-mediated allergies by the age of 5 years. Conclusions: The 25-OHD levels in early childhood are associated with the emergence of allergy, but the association appears to be nonlinear.

Placental mtDNA content and environmental exposure: a multipollutant approach

Introduction: Exposure to environmental pollutants might affect placental functioning and thus also fetal growth. Placental mitochondrial DNA (mtDNA) content can be indicative of oxidative damage to the placenta during fetal development. However, discriminating between the relevant exposures that influence placental mtDNA from a mixture of pollutants is currently lacking. Methods: Four perfluoralkyl compounds, ten persistent organic pollutants and six heavy metals were quantified in cord blood serum samples of 239 newborns. mtDNA content was measured in placental tissue using qPCR. We first applied an adaptive LASSO (least absolute shrinkage and selection operator) penalized regression model to identify independent associations between environmental pollutants and placental mtDNA content, when adjusting for mother newborn-characteristics: newborn’s sex, gestational age, birth weight, season of birth, maternal age, education, pre-pregnancy BMI, parity, smoking during pregnancy and ethnicity which were not penalized. Then adjusted estimates were obtained using unpenalized multiple-exposure linear regression models evaluating the association with placental mtDNA content. Results: Based on adaptive LASSO penalized regression, perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHXS), p,p’-DDE, lindane, PCB146, PCB153, thallium and arsenic were identified to be independently predictive of placental mtDNA content. In an adjusted multiple exposure model we observed a significant percent change (95% CI) in mtDNA content for every doubling of the following pollutants: 10% increase (1 to 19%, p=0.02) mtDNA content for lindane, 15% decrease (-27 to -2%, p=0.02) for thallium and 5% increase (1 to 10%, p=0.02) for arsenic. Conclusion: In a multi-pollutant exposure model, environmental pollutants compromise placental mitochondrial function as exemplified by mtDNA content.

Occurrences of major polybrominated diphenyl ethers (PBDEs) in maternal and fetal cord blood sera in Korea

Polybrominated diphenyl ethers (PBDEs) are of growing public health concern because of their potential toxicities which range from endocrine disruption to neurodevelopment. However, information on their exposure among sensitive human populations is limited. The objectives of this study were to determine the levels of major PBDEs in blood sera of pregnant women and their matching newborn infants. For this purpose, a total of 198 maternal blood samples and 118 matching umbilical cord blood samples were collected from four regions of South Korea in 2011, and were determined for 19 PBDE congeners. Various demographic, dietary, and behavioral characteristics were asked in a questionnaire survey. Average concentration of total PBDEs in maternal blood serum was 3.34±8.42ng/g lipid weight (lw) at delivery and 3.14±7.46ng/g lw at 6months of pregnancy, respectively. In cord blood serum, an average of 9.37±12.60ng/g lw was detected. Among the measured PBDE congeners, BDE-47, BDE-99 and BDE-153 were most dominant in both maternal and cord blood sera. Relatively higher levels of BDE-99 were detected in cord blood serum. Strong positive correlations were detected between maternal and cord blood serum samples, indicating the importance of maternal transfer. Health consequences of transplacental exposure to PBDEs among fetuses and newborn infants warrant further investigation.

No association between exposure to perfluorinated compounds and congenital cryptorchidism: a nested case–control study among 215 boys from Denmark and Finland

Geographical differences in the occurrence of diseases in male reproductive organs, including malformation in reproductive tract, between Denmark and Finland have been reported. The reason for these differences is unknown, but differences in exposure to chemicals with endocrine-disrupting abilities have been suggested. Among these chemicals are perfluoro-alkylated substances (PFASs), a group of water- and grease-repellent chemicals used in outdoor clothes, cookware, food packaging, and textiles. In this study, we, therefore, investigated differences in PFAS exposure levels between Denmark and Finland and the association between cord blood PFAS levels and congenital cryptorchidism. Boys from a joint ongoing prospective birth cohort study were included. We analyzed PFAS levels in cord blood serum samples collected from 29 Danish boys with congenital cryptorchidism, 30 healthy Danish matched controls recruited from 1997 to 2001, 30 Finnish cases, and 78 Finnish healthy matched controls recruited from 1997 to 1999. Additionally, 48 Finnish cases recruited from 2000 to 2002 were included. Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) were detected in all the 215 Danish and Finnish cord blood samples with significantly higher levels being observed in the Danish samples (medians: PFOA, 2.6 ng/ml and PFOS, 9.1 ng/ml) than in the Finnish samples (medians: PFOA, 2.1 ng/ml and PFOS, 5.2 ng/ml). We found no associations between cord blood PFOA and PFOS levels and congenital cryptorchidism after adjustment for confounders. Our data indicate that women in Denmark and Finland are generally exposed to PFOA and PFOS but there are differences in exposure levels between countries. We found no statistically significant association between cord blood PFOA and PFOS levels and congenital cryptorchidism; however, our study was small and larger studies are warranted.

Maternal Weight Status, Cord Blood Leptin and Fetal Growth: a Prospective Mother–Child Cohort Study (Rhea Study)

Leptin is an adipocyte-secreted hormone that regulates energy homeostasis, while its role in fetal programming remains poorly understood. We aimed to evaluate the effect of maternal weight status on cord blood leptin levels and their combined effect on fetal growth. We included 638 mother-child pairs from the prospective mother-child cohort 'Rhea' study in Crete, Greece with singleton pregnancies, providing cord blood serum samples for leptin analysis and complete data on birth outcomes. Multivariable logistic and linear regression models were used adjusting for confounders. Generalised additive models were used to explore the form of the relationship between cord leptin and continuous birth outcomes. Log cord leptin was positively associated with birthweight {β-coef: 176.5 [95% confidence interval (CI): 133.0, 220.0] }, ponderal index (β-coef: 1.0 [95% CI: 0.6, 1.4] ) and gestational age (β-coef: 0.7 [95% CI: 0.5, 0.8] ). Excessive weight gain during pregnancy was associated with a threefold increased risk for cord hyperleptinaemia {relative risk (RR): 3.0, [95% CI: 1.5, 6.3] }. Maternal pre-pregnancy overweight/obesity [body mass index (BMI) ≥25 kg/m(2) ] increased the risk of giving birth to a hyperleptinaemic neonate (RR: 2.1 [95% CI: 1.4, 3.2] and the effect of log leptin on birthweight (β-coef: 219.1 [95% CI: 152.3, 285.9] compared with women with a BMI <25 kg/m(2) (β-coef: 150.5 [95% CI: 93.1, 207.9]. Higher cord blood leptin levels are associated with increased size at birth and gestational age, while maternal pre-pregnancy BMI and weight gain during pregnancy represent significant indicators of cord blood leptin.

Evaluation of the Liaison Automated Testing System for Diagnosis of Congenital Toxoplasmosis

Congenital toxoplasmosis is a worldwide health problem, and different screening strategies exist. Testing of toxoplasma-specific antibodies in infants identifies congenital toxoplasmosis during the first year of life. However, experience with commercial available immunoassays is limited. The aim of this study was to evaluate both the performance and analytical characteristics of the Liaison diagnostic system in infants. In a retrospective study, serum Toxoplasma gondii antibodies were measured in samples from 333 infants, including 212 noninfected infants and 121 infants with congenital toxoplasmosis. A total of 1,157 umbilical cord blood and peripheral serum samples were analyzed. Liaison toxoplasma-specific IgG and IgM antibodies and the IgG avidity index were compared to the infection status of the infant, determined by the Sabin-Feldman dye test and immunosorbent agglutination assay--IgM. All noninfected infants were seronegative by Liaison IgG within the first year of life. The Liaison system showed a sensitivity of 81.8%, a specificity of 100.0%, a positive predictive value of 100.0%, a negative predictive value of 90.6%, and overall agreement of 84.4% by comparison with the dye test. Overall agreement of both IgM test systems was 96.0%. In this study cohort, avidity did not show a potential diagnostic benefit for the detection of congenital infection. In conclusion, the Liaison system is a valuable tool to monitor the serologic course of infants at risk. A final serologic confirmatory test is recommended to improve the rate of detection of congenital toxoplasmosis at 1 year of life. Protocols of routine follow-up testing in infants and accurate diagnostic tools after acute gestational infections are needed to improve medical care.

A proteome signature for intrauterine growth restriction derived from multifactorial analysis of mass spectrometry‐based cord blood serum profiling

Intrauterine growth restriction (IUGR) is defined as a condition in which the fetus does not reach its genetically given growth potential, resulting in low birth weight. IUGR is an important cause of perinatal morbidity and mortality, thus contributing substantially to medically indicated preterm birth in order to prevent fetal death. We subjected umbilical cord blood serum samples either belonging to the IUGR group (n = 15) or to the control group (n = 15) to fractionation by affinity chromatography using a bead system with hydrophobic interaction capabilities. So prepared protein mixtures were analyzed by MALDI-TOF mass spectrometric profiling. The six best differentiating ion signals at m/z 8205, m/z 8766, m/z 13 945, m/z 15 129, m/z 15 308, and m/z 16 001 were collectively assigned as IUGR proteome signature. Separation confidence of our IUGR proteome signature reached a sensitivity of 0.87 and a specificity of 0.93. Assignment of ion signals in the mass spectra to specific proteins was substantiated by SDS-PAGE in conjunction with peptide mass fingerprint analysis of cord blood serum proteins. One constituent of this proteome signature, apolipoprotein C-III(0) , a derivative lacking glycosylation, has been found more abundant in the IUGR cord blood serum samples, irrespective of gestational age. Hence, we suggest apolipoprotein C-III(0) as potential key-marker of the here proposed IUGR proteome signature, as it is a very low-density lipoprotein (VLDL) and high-density lipoprotein (HDL) member and as such involved in triglyceride metabolism that itself is discussed as being of importance in IUGR pathogenesis. Our results indicate that subtle alterations in protein glycosylation need to be considered for improving our understanding of the pathomechanisms in IUGR.

OS079. Fetal deglycosylated apolipoprotein C-III (Apo C-III0) concentration is altered in intrauterine growth restriction

We recently demonstrated that serum lipid levels are altered in growth restricted fetuses (IUGR) [1]. We now aimed to analyse the proteome profile of umbilical cord blood in order to gain a greater understanding about metabolic changes in IUGR fetuses. umbilical cord blood serum samples of IUGR (n=15) and of gestational age matched controls (CN; n=15) were subjected to fractionation by affinity chromatography using a bead system with hydrophobic interaction capabilities. So prepared protein mixtures were forwarded to MALDI-TOF mass spectrometric profiling. Assignment of ion signals in the mass spectra to specific proteins was substantiated by SDS-PAGE in conjunction with peptide mass fingerprint analysis. Concentrations of proteins of interest were additionally measured by ELISA. Statistical estimations were performed by Student's t-test and calculation of Spearman's correlation coefficient. MALDI mass spectra showed on average more than 60 protein ion signals between m/z 4000 and 25,000. The six best differentiating ion signals were found at m/z 8205, m/z 8766, m/z 13,945, m/z 15,129, m/z 15,308, and m/z 16,001. One of the constituent of this proteome signature is the deglycosylated form of apolipoprotein C-III, apo C-III0 (8766 m/z) that is known to prevent triglycerides from catabolism. While total Apo CIII concentration tended to be decreased (IUGR 22.54μg/mL SD 10.25. CN 29.9μg/mL SD 15.46. p=0.1355) calculated Apo C-III0 concentration levels has been found to be more abundant in the IUGR cord blood serum samples (IUGR 1.99μg/mL SD 0.85. CN 1.15μg/mL SD 0.55. p<0.0001). Moreover, fetal triglycerid levels were significantly increased in IUGR (IUGR 16.7mg/dL SD 7.58. CN 56.5mg/dL SD 49.92. p-value after log transformation =0.0008)and apo C-III0 was highly correlated to fetal triglyceride levels (rho=0.694). Using mass spectrometric approaches we successfully developed an IUGR specific proteome signature derived from human umbilical cord blood samples. Most interesting the deglycosylated form of the apolipoprotein C-III (apoC-III0) was found to be significantly increased in IUGR and thus might lead to reduced triglyceride catabolism. This observation is in agreement with the known observation of triglyceride levels being increased in IUGR fetuses. Our results indicate that subtle alterations in protein glycosylation need to be considered for improving our understanding of the pathomechanisms in IUGR.

A novel method for the quantitative determination of free and conjugated bisphenol A in human maternal and umbilical cord blood serum using a two-step solid phase extraction and gas chromatography/tandem mass spectrometry

Bisphenol A is widely used as a monomer in the manufacture of polycarbonates and epoxy resins, as an antioxidant in polyvinyl chloride (PVC) plastics and as an inhibitor of end polymerisation in PVC. Several different methods have been used to quantify total BPA in biological specimens. However, quantification of both free and conjugated BPA continues to present challenges. Moreover, there is limited data concerning fetal exposure. Therefore, the objective of this study was to develop a new method for the analysis of both free and conjugated BPA in human maternal and umbilical cord blood serum. For the analysis of free BPA, the method consisted of a liquid–liquid extraction followed by a two-step solid-phase extraction sample cleanup on Florisil and Oasis HLB sorbents, derivatization of the extract using N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) and analysis by gas chromatography/tandem mass spectrometry (GC/EI-MS/MS). To determine the amount of conjugated BPA in serum samples, bisphenol A-d6 β-glucuronide (4-[1-(4-hydroxyphenyl)-1-methylethyl-d6]phenyl β-d-glucopyranosiduronic acid) was added to each sample prior to enzymatic deconjugation. The MDL and LOQ for BPA were 0.026ng/mL and 0.087ng/mL, respectively. The observed recoveries ranged between 65% and 88%. The new method was applied to the determination of paired human maternal and umbilical cord blood serum samples. The results demonstrated that total BPA concentrations in human maternal serum at mid-pregnancy and at delivery ranged from <0.026ng/mL to 10.425ng/mL (median 0.548ng/mL, n=12) and <0.026ng/mL to 3.048ng/mL (median 1.461ng/mL), respectively. Results for matching umbilical cord blood serum BPA concentrations were in the range of <0.026–2.569ng/mL (median 1.823ng/mL). The concentrations measured in this study agreed well with BPA levels in human serum reported internationally. Only 2 mid-pregnancy serum samples out of 12 contained quantifiable amounts of conjugated BPA, indicating that BPA–glucuronide is not abundant in either human maternal or umbilical cord blood serum.

Validación de pruebas ELISA IgM anti-Toxoplasma para uso en programas de tamización en recién nacidos

ObjectivesTo evaluate and validate the detection of anti-Toxoplasma IgM ELISA in umbilical cord blood by means of two different commercial assays and to correlate the results with the diagnosis of congenital infection in children by serological follow up and clinical data. Materials and methodsWe evaluated the commercial anti-Toxoplasma IgM ELISA kitÔ from Vircell (Granada, Spain) compared to the results of Toxoplasma IgM Western blotÔ (LDbio, Lyon, France) and IgM ELISA testÔ from Labsystems (Finland). We obtained the receptor-operator curve (ROC) for the IgM ELISA assay form Vircell and Labsystems. We studied 105 umbilical cord blood serum samples from Colombian children from six different cities by Western blot, and clinical and serological follow up for positive cases. The kappa agreement index was determined for the 105 sera obtained from umbilical cords. ResultsThe Vircell assay showed a better performance with a cut-off index of 8 against a 16 for Labsystems for enzyme immunounits (EUI). When the results were evaluated against the Western blot assay, the Vircell IgM assay had a sensitivity of 100% (IC95%: 71.8-100) and a specificity of 78% (IC95%: 69-85.7), the IgM assay from Labsystems had a sensitivity of 100% (IC95% 71.8-100) and a specificity of 100% (IC95% 96-100). Agreement between both tests (Labsystems and Vircell) was 80% and had a kappa index of 0.45. ConclusionsA cut-off point of 8 for the anti-Toxoplasma IgM ELISA assay from Vircell and 16 EIU for the Labsystems assay allow the identification of congenital infections in umbilical cord blood samples from Colombian children.

Fetal and maternal immune responses to methylmercury exposure: A cross-sectional study

Methylmercury (MeHg) is a ubiquitous environmental contaminant with known neurodevelopmental effects. In humans, prenatal exposures primarily occur through maternal consumption of contaminated fish. In this study, we evaluated the association between prenatal exposure to MeHg and titers of total immunoglobulins (Ig) and specific autoantibodies in both mothers and fetuses by analyzing maternal and cord blood serum samples. We examined multiple immunoglobulin isotypes to determine if these biomarkers could inform as to fetal or maternal responses since IgG but not IgM can cross the placenta. Finally, we evaluated serum cytokine levels to further characterize the immune response to mercury exposure. The study was conducted using a subset of serum samples ( N=61 pairs) collected from individuals enrolled in a population surveillance of MeHg exposures in the Brazilian Amazon during 2000/2001. Serum titers of antinuclear and antinucleolar autoantibodies were measured by indirect immunofluorescence. Serum immunoglobulins were measured by enzyme-linked immunosorbent assay (ELISA) and BioPlex multiplex assay. Serum cytokines were measured by BioPlex multiplex assay. In this population, the geometric mean mercury level was within the 95th percentile for US populations of women of childbearing age but the upper level of the range was significantly higher. Fetal blood mercury levels were higher (1.35 times) than those in their mothers, but highly correlated (correlation coefficient [ r]=0.71; 95% CI: 0.54, 0.89). Total IgG ( r=0.40; 95% CI: 0.19, 0.62) and antinuclear autoantibody (odds ratio [OR]=1.05; 95% CI: 1.02, 1.08) levels in paired maternal and fetal samples were also associated; in contrast, other immunoglobulin (IgM, IgE, and IgA) levels were not associated between pairs. Total IgG levels were significantly correlated with both maternal ( r=0.60; 95% CI: 0.25, 0.96) and cord blood mercury levels ( r=0.61; 95% CI: 0.25, 0.97), but individual isotypes were not. Serum cytokines, interleukin-1β ( r=0.37; 95% CI: 0.01, 0.73), interleukin-6 ( r=0.34; 95% CI: 0.03, 0.65), and tumor necrosis factor-α ( r=0.24; 95% CI: 0.015, 0.47), were positively correlated between maternal and fetal samples. Antinuclear and antinucleolar autoantibody titer and serum cytokine levels, in either maternal or cord blood, were not significantly associated with either maternal or cord blood mercury levels. These data provide further evidence that there are likely IgG biomarkers of mercury-induced immunotoxicity in this population since IgG levels were elevated with increased, and associated with, mercury exposure. However, unlike previous data from adult males and non-pregnant females, we found no evidence that antinuclear and antinucleolar autoantibody titer is a reliable biomarker of mercury immunotoxicity in this population.

Relationships of Umbilical and Maternal Adiponectin, Resistin and Osteoprotegerin to Maternaland Newborn Anthropometric Characteristics

Introduction. Adiponectin, resistin and osteoprotegerin (OPG) are cytokines expressed in the adipose tissue. Pregnancy is associated with gradually increased maternal levels of these molecules, also detected in significant amounts in umbilical cord blood serum samples. Aim, patients and methods. To establish the relationships of maternal and umbilical adiponectin, resistin and OPG levels to both maternal and fetal anthropometric measurements and insulin sensitivity, 28 mother-newborn pairs were enrolled in the study. Blood samples were collected in a fasting state, after delivery, and serum insulin, C-peptide, sex hormone-binding globulin, adipocytokines, OPG and bone specific alkaline phosphatase (BAP) were measured. Results. Compared to maternal values, umbilical serum adiponectin levels were about 3-fold higher; additionally, significantly higher resistin and lower OPG levels were observed. Stratification of umbilical and maternal adiponectin levels according to tertiles of birth body weight demonstrated significantly lower maternal adiponectin levels by tertiles of neonatal body weight. No relationships were noticed between infant birth weight and maternal or umbilical serum resistin and OPG, respectively. Umbilical resistin was significantly associated to both maternal resistin and umbilical adiponectin. Multiple regression analysis showed that maternal BMI, umbilical insulin, C-peptide and resistin explained 71.83% of umbilical serum adiponectin variability. Umbilical resistin was independently predicted by umbilical adiponectin, umbilical C-peptide and maternal BMI, and the model explained 81.49% of umbilical resistin levels. Conclusions. In human, umbilical serum adiponectin and resistin levels are significantly higher compared to adults. These adipokines may mediate the effects of maternal body mass on fetal development. The biology of the OPG/RANKL cytokine system in fetuses and newborns needs further research.

Transplacental Transport of IgG Antibodies Specific for Pertussis, Diphtheria, Tetanus, Haemophilus influenzae Type b, and Neisseria meningitidis Serogroup C Is Lower in Preterm Compared With Term Infants

Maternal antibodies, transported through the placenta during pregnancy, contribute to the protection of infants from infectious diseases during the first months of life. The aim of this study was to measure the concentration of antibodies against several vaccine-preventable diseases in paired maternal and cord blood serum samples in preterm and term infants and to assess placental transfer ratios and infant antibody concentrations against vaccine-preventable diseases. Antibody concentrations specific against pertussis proteins (pertussis toxin, filamentous hemagglutinin, pertactin, and fimbriae), diphtheria and tetanus toxins, and antibody concentrations specific against polysaccharides from Haemophilus influenzae type b and Neisseria meningitidis serogroup C were measured in cord blood samples from preterm (<32 weeks and 1500 g) and term infants and maternal serum samples, using a fluorescent bead-based multiplex immunoassay. A total of 96 preterm and 42 term infants and their mothers were included in the study. Placental transfer ratios of antibodies against all vaccine antigens were significantly lower in preterm infants (medians varied from 0.26 to 0.86) compared with term infants (medians, 0.74-1.89; all antibodies P < 0.05). Furthermore, polysaccharide-vaccine-specific antibodies showed lower transplacental transport ratios than protein-vaccine-specific antibodies. Maternal concentrations are the most important determinants of infant antibody concentrations against vaccine-preventable diseases. Preterm infants benefit to a lesser extent from maternal antibodies against vaccine-preventable diseases than term infants, posing them at higher risk for infectious diseases in the first months of life.

Association of cord blood cytokine levels with wheezy infants in the first year of life

As antenatal environment may influence the development of atopy-predisposing immune response, cord blood cytokine productions may be an important predictor for wheezing. We investigated cord blood cytokines in a prospective birth cohort, intensively monitored for wheezy infant outcome at 1 yr. Cord blood serum samples from 269 children were assayed for interleukin (IL)-1beta, -2, -4 to -8, -10, -12 (p70), -13, and -17, interferon-gamma, tumor necrosis factor-alpha, granulocyte-macrophage colony-stimulating factor, granulocyte colony-stimulating factor (G-CSF), monocyte chemotactic protein-1, and macrophage inflammatory protein-1beta. Associations between family histories, antenatal and perinatal factors, cord blood cytokine concentrations, and wheezy infant outcomes (wheezing more than two times) were analyzed. In cord blood sera from 269 children, there were associations between high levels of IL-6, -8 and G-CSF concentrations, and cesarean section. Data at 1 yr were obtained from 213 infants, including 33 wheezy infants. Risk of wheezing was related to gestational age, birth weight, cesarean section, and maternal eczema, but not to bacterial/viral infection during pregnancy, maternal asthma, maternal smoking, or paternal history. High level of cord blood IL-8 concentration had a significant association with wheezy infant outcomes at 1 yr (p = 0.025). By using multivariate logistic regression analysis, birth weight [odds ratio(OR) = 0.998, 95% confidence interval (CI) = 0.997-1.000] and maternal eczema (OR = 5.356, 95% CI = 1.340-21.41), but no other factors, were significant predictors of wheezy infants. Birth weight, gestational age, and maternal history were important risk factors for wheezing in the first year of life. Several cord blood cytokine productions were influenced by cesarean section, and IL-8 may be a predictor for recurrent wheezing at 1 yr.

Prenatal Exposure to Organochlorine Chemicals at Environmental Levels has a Negative Impact on Sex Steroids in Newborns

TM1-O-02 Introduction: Organochlorine chemicals such as dioxins and PCBs interact with endocrine systems and are therefore considered endocrine disruptors (IPCS, 2002). As yet, no data exist showing alterations of sex steroids in young children to be associated with low-level background exposure to organochlorines. We studied the associations between the background body burden of PCBs and PCDD/Fs in pregnant mothers and sex steroids (testosterone, estradiol) in their newborn babies. Methods: A total of 232 pregnant women between 19 and 42 years of age were recruited between 2000 and 2003; 196 healthy mother-infant pairs meeting the inclusion criteria participated. Maternal blood samples were taken in the 32nd week of pregnancy, and human spot milk samples (about 150 mL) were collected at around 2 weeks after birth. Cord blood serum samples (5–10 mL) were also collected. All samples were kept deep frozen until analysis. Organochlorine concentrations in maternal serum and milk were measured under strict quality control conditions by HRGC/HRMS. Testosterone and estradiol in cord serum were measured under stringent internal quality control conditions using a competitive immunoassay with direct chemiluminescent technology. Multiple linear regression analysis was used to model the associations between organochlorine levels and concentrations of testosterone/estradiol in cord serum after adjustment for confounding (mother's age, mother's nationality, alcohol before pregnancy, smoking and medication during pregnancy, APGAR score, parental education, parental occupation, mother's body mass index). Organochlorine levels were expressed as toxic equivalents of TCDD (WHO-TEq). Dioxin-like (DL) and non-dioxin-like PCBs (NDL) were distinguished. Results: After adjustment for confounding, both PCBs and PCDD/Fs in maternal blood and milk exhibited significant and robust negative associations with cord serum testosterone and estradiol concentrations. In most cases, these negative effects were stronger for dioxins and DL-PCBs as compared with NDL-PCBs. Furthermore, the effects on estradiol were stronger in male infants than in females, whereas the reverse was true for testosterone. Discussion and Conclusions: We have shown here that prenatal exposure to organochlorine chemicals at environmental levels of exposure has a significant negative impact on both testosterone and estradiol levels in newborns. This, to the best of our knowledge, has not been reported before. There is evidence for retarded sexual development in adolescents to be associated with environmental exposure to PCB/dioxins (Staessen et al, 2001). Our data are in line with experimental animal findings following prenatal exposure to an organochlorine mixture corresponding to that typically found in human milk (Kaya et al, 2001).

Umbilical Serum Insulin-like growth Factor 1 (IGF-1) in Newborns: Effects of Gestational Age, Postnatal Age, and Nutrition

The aim of this study was to determine the relationship between nutrition, gestational age, and birth weight, and serum insulin-like growth factor 1 (IGF-1) levels in newborns. The first study group consisted of sixty newborns: thirty were fed with human breast milk and the others were fed with infant formula. Serum samples were obtained from all the newborns on days one and seven of life. Seventy-two pregnant women and their neonatal cord blood serum samples were obtained in a labor ward in the study group. All the serum samples were analyzed for IGF-1 by immunoassay. Newborns fed with human milk had higher serum IGF-1 concentrations compared to formula-fed controls (p < 0.05). Cord IGF-1 levels showed a negative correlation with birthweight (p < 0.05) and a positive correlation with gestational age (p < 0.05). These findings suggest that IGF-1 levels during the neonatal period are influenced by gestational age, birth weight, and nutrition.

Association between antenatal cytokine production and the development of atopy and asthma at age 6 years

Various lines of evidence suggest that antenatal factors are important in determining susceptibility to atopy and asthma. One possible mechanism is cytokines, production of which in the placenta is high throughout gestation and which protect placental integrity via control of local immunological homoeostasis. We investigated antenatal cytokine concentrations in a prospective birth cohort, intensively monitored for atopy and asthma outcomes at age 6 years. Cryopreserved cord-blood serum samples from 407 children were assayed for interleukins 4, 5, 6, 10, 12, and 13, interferon gamma, and tumour necrosis factor alpha (TNFalpha). Associations between family, antenatal, and perinatal factors, cord-blood cytokine concentrations, and atopy or asthma outcomes were analysed by logistic regression. Causal effects of cytokines on outcomes were estimated by propensity scores based on family, antenatal, and perinatal factors. Detectable cord-blood concentrations of interleukin 4 and interferon gamma were each associated with lower risk of physician-diagnosed asthma (adjusted odds ratios 0.60 [95% CI 0.37-0.99] and 0.60 [0.37-0.97] respectively), current asthma (0.59 [0.33-1.00] and 0.39 [0.22-0.71]), and current wheeze (0.55 [0.32-0.93] and 0.52 [0.31-0.90]) and atopy (sensitisation to some inhalant allergens) outcomes at 6 years. High concentrations of TNFalpha were associated with lower risk of atopy but not with asthma risk. These associations were broadly unaltered by propensity-score adjustment. Maternal smoking was associated with higher risk of both wheeze at 6 years and lower concentrations of interleukin 4 and interferon gamma in cord blood. The mechanism underlying attenuated T-helper-1/T-helper-2 cytokine production in high-risk children also apparently operates in control of cytokine production in the fetoplacental unit. The finding that this mechanism is dysregulated by maternal smoking suggests it is a target for antenatal environmental factors relevant to asthma aetiology.

Measurement of bisphenol A levels in human blood serum and ascitic fluid by HPLC using a fluorescent labeling reagent

A sensitive column-switching HPLC method with fluorescence detection was developed for the determination of bisphenol A (BPA) in human blood serum and ascitic fluid samples. 4-(4,5-Diphenyl-1 H-imidazol-2-yl)benzoyl chloride (DIB-Cl) was used as the fluorescent label, and the excess reagent was removed by a column-switching technique. Liquid–liquid extraction with chloroform was used for the pretreatment of serum and ascitic fluid samples. BPA in both the samples could be determined in the concentration range of 0.1–7.0 ppb with the detection limit of 0.04 ppb at a signal-to-noise ratio of 3. The recoveries of BPA spiked to serum and ascitic fluid were 78.6 and 77.7%, respectively. The mean concentrations of BPA ( n=9) in maternal and umbilical cord blood sera obtained from healthy pregnant women were 0.46±0.20 and 0.62±0.13 ppb, respectively. BPA levels ( n=21) in blood sera and ascitic fluid obtained from the patients with sterility were also determined to be 0.46±0.20 and 0.56±0.19 ppb, respectively. Relationships of BPA concentrations were observed between maternal and umbilical cord blood serum samples ( r=0.626), as well as blood serum and ascitic fluid samples ( r=0.785).

Bilirubin–human serum albumin interaction monitored by capillary zone electrophoresis

Capillary zone electrophoresis was used to monitor the interaction between bilirubin and human serum albumin. Cord blood serum samples were injected directly into an uncoated fused-silica capillary (30 cm × 50 µm i.d.) and separation was accomplished within 4 min without extensive sample pretreatment. The most suitable running buffer to separate free bilirubin from albumin bound bilirubin was found to contain 1.0 mmol/L EDTA, 5% acetonitrile and 15 mmol/L phosphate with pH adjusted to 8.4. Approximately two bilirubin dianions could be bound per human serum albumin molecule in the cord blood serum. The binding constant was estimated to be 1.1 × 105 (L/mol) at 25°C and pH 8.4. The peak area ratio of free bilirubin to total bilirubin can be used to determine the bilirubin binding capacity of cord blood serum for the concentration range of total bilirubin from 204 to 340 µmol/L using 1:5 diluted cord blood seras. Copyright © 1999 John Wiley & Sons, Ltd.

Bilirubin-human serum albumin interaction monitored by capillary zone electrophoresis.

Capillary zone electrophoresis was used to monitor the interaction between bilirubin and human serum albumin. Cord blood serum samples were injected directly into an uncoated fused-silica capillary (30 cm x 50 microns i.d.) and separation was accomplished within 4 min without extensive sample pretreatment. The most suitable running buffer to separate free bilirubin from albumin bound bilirubin was found to contain 1.0 mmol/L EDTA, 5% acetonitrile and 15 mmol/L phosphate with pH adjusted to 8.4. Approximately two bilirubin dianions could be bound per human serum albumin molecule in the cord blood serum. The binding constant was estimated to be 1.1 x 10(5) (L/mol) at 25 degrees C and pH 8.4. The peak area ratio of free bilirubin to total bilirubin can be used to determine the bilirubin binding capacity of cord blood serum for the concentration range of total bilirubin from 204 to 340 mumol/L using 1:5 diluted cord blood seras.