Role of placental barrier on trace element transfer in maternal fetal system and hypertensive disorders complicating pregnancy and gestational diabetes mellitus.

BACKGROUND: Hypertensive disorders complicating pregnancy (HDCP) and gestational diabetes mellitus (GDM) can affect the placental barrier function to varying degrees. However, current studies show that the transfer and distribution characteristics of trace elements in the maternal-fetal system are still unclear. This study investigated the effect of the placental barrier on the transfer of trace elements from mother to fetus and its relationship with HDCP and GDM. METHODS: A case-control method was used in this study. 140 pairs of samples were collected; 60 were from healthy pregnant women, and 80 were from patients with pregnancy complications. The contents of trace elements in paired samples were determined by inductively coupled plasma-mass spectrometry (ICP-MS). SPSS software was used to analyze the differences in trace element levels in matched samples of each group. The correlations were analyzed based on Pearson's correlation factor (r). RESULTS: The distribution characteristics of Fe content in the pathological group (HDCP group and GDM group) were the same as those in the normal group (umbilical cord blood > maternal blood > placenta), but there was no significant difference in the iron content in maternal blood and cord blood of pathological group. The distribution characteristics of Mn content in the pathological group (placenta > umbilical cord blood > maternal blood) were changed compared with those in the normal group (placenta > maternal blood > umbilical cord blood). In addition, the placental Cr content and cord blood Cr and Ni content of the pathological group were higher than those of the normal group. HDCP placental Cr and GDM placental Fe levels were significantly correlated with the Apgar score. CONCLUSIONS: The transfer of Fe and Mn and the placental barrier function of Cr and Ni in the maternal-fetal system of HDCP and GDM are significantly altered, which directly or indirectly increases the maternal and fetal health risk.

Placental Barrier on Cadmium Transfer from Mother to Fetus in Related to Pregnancy Complications.

Purpose: As two of the most severe and common medical disorders during pregnancy, gestational diabetes mellitus (GDM) and hypertensive disorder complicating pregnancy (HDCP) cause adverse effects on placental barrier function and thus may lead to a high risk of intrauterine exposure to toxic metals from mother to fetus. This study investigates the impact of the placental barrier on the transfer of cadmium (Cd) from mother to fetus and the relationship between pregnancy complications. Methods: A total of 107 pairs of samples were collected in Kunming, China; 29 were from healthy pregnant women, and 78 were from patients with pregnancy complications. Cd was measured in each mother's placenta and maternal and umbilical cord blood. The expressions of MT and Cd-MT complex in blood and placental tissue samples were determined by enzyme-linked immunosorbent assay (ELISA). Results: The cesarean section rate in the whole pathological group (60.7%) was higher than that in the normal group (20.7%), and the ratio of the effective barrier (ratio of maternal blood to umbilical cord blood>1) in the pathological group (74%) was lower than that in the normal group (79%). In addition, the proportion of practical placental barriers in women aged 20-25 years was 83.3%, 76.3% in women aged 26-30 years, 74.3% in women aged 31-35 years, 70% in women aged 36-40 years, and 71% in women aged 40-45 years. The Cd content in the placenta of the three pathological groups was significantly higher than that in maternal and umbilical cord blood (P<0.05), and the distribution of Cd was the same as that in the normal group. However, there was no significant difference between maternal and umbilical cord blood Cd concentrations in the pathological group. The Cd concentration in the normal group's maternal blood was significantly higher than that in cord blood (P<0.05). In addition, the expression levels of both metallothionein (MT) and Cd-MT complex in placenta is much higher than in maternal and umbilical blood, and which in normal group are significantly higher than those in pathological group. Conclusion: Both mothers and fetuses are at increased health risk for pregnancy disorders when maternal age, BMI, or body weight increases. Increased maternal age increases the likelihood of Cd transfer from the mother to the fetus. Pregnancy complications may induce lower expression of MT, thus reducing the Cd-MT complex in the placenta, weakening the placental barrier, and increasing the risk of Cd transfer and exposure to the fetus.

Pregnancy complications effect on the nickel content in maternal blood, placenta blood and umbilical cord blood during pregnancy.

BACKGROUND: Nickel (Ni) may accumulate in the human body and has biological toxicity and carcinogenicity. Ni has an extensive impact on the health of pregnant women and fetuses during gestation. AIM: To evaluate Ni exposure in pregnant women in Kunming, Yunnan Province, China; to describe the distribution of Ni in the maternal-fetal system and placental barrier function; and to investigate the effect of Ni exposure on fetal health in mothers with pregnancy complications. METHODS: Seventy-two pregnant women were selected using a case-control design. The women were divided into two groups: The control group (no disease; n = 29) and the disease group [gestational diabetes (GDM), hypertensive disorder complicating pregnancy (HDCP), or both; n = 43]. The pregnant women in the disease group were further divided as follows: 14 cases with GDM (GDM group), 13 cases with HDCP (HDCP group) and 16 cases with both GDM and HDCP (disease combination group). Basic information on the pregnant women was collected by questionnaire survey. Maternal blood, placenta blood and cord blood were collected immediately after delivery. The Ni content in paired samples was determined using inductively coupled plasma mass spectrometry. RESULTS: Compared to the control group, age was higher and body mass index was greater in pregnant women in the disease groups (28.14 ± 2.54 vs 28.42 ± 13.89, P < 0.05; 25.90 ± 3.86 vs 31.49 ± 5.30, P < 0.05). The birth weights of newborns in the HDCP group and the control group were significantly different (2.52 ± 0.74 vs 3.18 ± 0.41, P < 0.05). The content of Ni in umbilical cord blood in the entire disease group was higher than that in the control group (0.10 ± 0.16 vs 0.05 ± 0.07, P < 0.05). CONCLUSION: In the maternal-fetal system of women with pregnancy complications, the barrier effect of the placenta against Ni is weakened, thus affecting healthy growth of the fetus in the uterus.

Highly sensitive aflatoxin B1 sensor based on DNA-guided assembly of fluorescent probe and TdT-assisted DNA polymerization.

A novel aptasensor, based on a perylene probe (PAPDI; N,N'-bis(propylenetrimethylammonium)-3,4,9,10-perylenediimide), was developed for the detection of aflatoxin B1 (AFB1) in maize samples. AuNPs/DNA composites were synthesized and integrated with aptamers-modified magnetic nanoparticles (MNPs) via DNA hybridization. For AFB1 determination, AuNPs/DNA composites were released from MNPs through specific binding of AFB1 with the aptamer and used for assembly of the PAPDI probe. To enhance the method sensitivity, terminal deoxynucleotidyl transferase (TdT)-catalyzed DNA polymerization was performed to elongate DNA on AuNPs/DNA composites. As a result, more PAPDI probes were assembled on the AuNPs/DNA composites. Through a multiple signal amplification strategy, the proposed method exhibited high sensitivity towards AFB1, with a detection limit of 0.01 nM (3.1 pg/mL). In summary, the proposed method has great potential to be a universal strategy for monitoring AFB1 in food samples.

A Label-Free Aptasensor for Ochratoxin a Detection Based on the Structure Switch of Aptamer.

A label-free sensing platform is developed based on switching the structure of aptamer for highly sensitive and selective fluorescence detection of ochratoxin A (OTA). OTA induces the structure of aptamer, transforms into G-quadruplex and produces strong fluorescence in the presence of zinc(II)-protoporphyrin IX probe due to the specific bind to G-quadruplex. The simple method exhibits high sensitivity towards OTA with a detection limit of 0.03 nM and excellent selectivity over other mycotoxins. In addition, the successful detection of OTA in real samples represents a promising application in food safety.

DNA-induced synthesis of biomimetic enzyme for sensitive detection of superoxide anions released from live cell.

In this work, we successfully fabricate a rapid, sensitive sensor for the detection of superoxide anions O2˙- based on graphene/DNA/Mn3(PO4)2 biomimetic enzyme. In the design, graphene is served as excellent carrier to improve the catalysis of Mn3(PO4)2 nanoparticles; and DNA adsorbed on graphene acts as medium to assist the growth of Mn3(PO4)2 on graphene. The fabricated graphene/DNA/Mn3(PO4)2 composites exhibit excellently electrochemical activity, significantly decrease the response time and increase the sensitivity of the sensor towards O2˙-. The successful detection of O2˙- released from cancer cell demonstrated its potential applications in biology and medicine.

Hierarchical Nafion enhanced carbon aerogels for sensing applications.

This work describes the fabrication of hierarchical 3D Nafion enhanced carbon aerogels (NECAGs) for sensing applications via a fast freeze drying method. Graphene oxide, multiwalled carbon nanotubes and Nafion were mixed and extruded into liquid nitrogen followed by the removal of ice crystals by freeze drying. The addition of Nafion enhanced the mechanical strength of NECAGs and effective control of the cellular morphology and pore size was achieved. The resultant NECAGs demonstrated high strength, low density, and high specific surface area and can achieve a modulus of 20 kPa, an electrical conductivity of 140 S m(-1), and a specific capacity of 136.8 F g(-1) after reduction. Therefore, NECAG monoliths performed well as a gas sensor and as a biosensor with high sensitivity and selectivity. The remarkable sensitivity of 8.52 × 10(3)µA mM(-1) cm(-2) was obtained in dopamine (DA) detection, which is two orders of magnitude better than the literature reported values using graphene aerogel electrodes made from a porous Ni template. These outstanding properties make the NECAG a promising electrode candidate for a wide range of applications. Further in-depth investigations are being undertaken to probe the structure-property relationship of NECAG monoliths prepared under various conditions.

Signal matching wavelet for ultrasonic flaw detection in high background noise.

The wavelet transform (WT) is widely used in ultrasonic flaw detection (UFD) systems because of its property of multiresolution time-frequency analysis. Those traditional WT-based methods for UFD use a wavelet basis with limited types to match various echo signals (called wavelet matching signals), so it is difficult for those methods to achieve the optimal match between echo signal and wavelet basis. This results in limited detection ability in high background noise for those WT-based methods. In this paper, we propose a signal matching wavelet (SMW) method for UFD to solve this problem. Unlike traditional UFD systems, in the proposed SMW, the transmitted signal is designed to be a wavelet function for matching a wavelet basis. This makes it possible to obtain the optimal match between the echo signal and the wavelet basis. To achieve the optimal match from the aspect of energy, we derive three rules for designing the transmitted signal and selecting the wavelet basis. Further, the parameter selection in applying the proposed SMW method to a practical UFD system is analyzed. In addition, a low-rate discrete WT structure is designed to decrease the hardware cost, which facilitates the practical application of the proposed SMW. The simulation results show that the proposed SMW can efficiently detect flaws in high background noise even with SNR lower than -20 dB, outperforming the existing methods by 5 dB.