Expression and Purification of Recombinant GHK Tripeptides Are Able to Protect against Acute Cardiotoxicity from Exposure to Waterborne-Copper in Zebrafish.

In this study, an alternative method is developed to replace chemical synthesis to produce glycyl-histidyl-lysine (GHK) tripeptides with a bacterial fermentation system. The target GHK tripeptides are cloned into expression plasmids carrying histidine-glutathione-S-transferase (GST) double tags and TEV (tobacco etch virus) cleavage sites at the N-terminus. After overexpression in Escherichia coli (E. coli) BL21 cells, the recombinant proteins are purified and recovered by high-pressure liquid chromatography (HPLC). UV-vis absorption spectroscopy was used to investigate the chemical and biological properties of the recombinant GHK tripeptides. The results demonstrated that one recombinant GHK tripeptide can bind one copper ion to form a GHK-Cu complex with high affinity, and the recombinant GHK peptide to copper ion ratio is 1:1. X-ray absorption near-edge spectroscopy (XANES) of the copper ions indicated that the oxidation state of copper in the recombinant GHK-Cu complexes here was Cu(II). All of the optical spectrum evidence suggests that the recombinant GHK tripeptide appears to possess the same biophysical and biochemical features as the GHK tripeptide isolated from human plasma. Due to the high binding affinity of GHK tripeptides to copper ions, we used zebrafish as an in vivo model to elucidate whether recombinant GHK tripeptides possess detoxification potential against the cardiotoxicity raised by waterborne Cu(II) exposure. Here, exposure to Cu(II) induced bradycardia and heartbeat irregularity in zebrafish larvae; however, the administration of GHK tripeptides could rescue those experiencing cardiotoxicity, even at the lowest concentration of 1 nM, where the GHK-Cu complex minimized CuSO4-induced cardiotoxicity effects at a GHK:Cu ratio of 1:10. On the other hand, copper and the combination with the GHK tripeptide did not significantly alter other cardiovascular parameters, including stroke volume, ejection fraction, and fractional shortening. Meanwhile, the heart rate and cardiac output were boosted after exposure with 1 nM of GHK peptides. In this study, recombinant GHK tripeptide expression was performed, along with purification and chemical property characterization, which revealed a potent cardiotoxicity protection function in vivo with zebrafish for the first time.

Changes in the relationship between ambient fine particle concentrations and childhood lung function over 5 years.

BACKGROUND: Exposure to ambient fine particles, particulate matter with an aerodynamic diameter of ≤2.5 µm (PM2.5), is a public health concern. Concentrations of ambient PM2.5 have changed temporally in the past 10 years after a series of action policies for improving air quality were implemented in Taiwan. In this study, temporal changes in the relationship between PM2.5 and lung function among children were investigated. METHODS: A nationwide respiratory health survey was conducted among Taiwanese elementary and middle school students in 2011 and again in 2016-2017. A questionnaire was administered to students, for whom forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) were measured using spirometry. During the study period, monthly concentrations of ambient PM2.5 were obtained from the monitoring stations of the Environmental Protection Administration. Lung function measurements were compared with ambient PM2.5 exposure using mixed-effects models. RESULTS: In the 2011 survey (mean PM2.5: 40.6 µg/m3), exposure to PM2.5 in the preceding 1-2 months was associated with a 2.2% decrease (95% confidence interval [CI]: -4.1%, -0.3%) in FVC and a 2.3% decrease (95% CI: -4.0%, -0.5%) in FEV1. By contrast, a significant relationship between PM2.5 concentrations and lung function was not observed in the 2016-2017 survey (mean PM2.5: 30.0 µg/m3). CONCLUSIONS: As improvement in air quality over time, the negative relationship between PM2.5 and childhood lung function tend to be not significant.

Changes in the relationship between childhood asthma and ambient air pollution in Taiwan: Results from a nationwide survey repeated 5 years apart.

BACKGROUND: Childhood asthma is a common disease whose prevalence is changing. Shift in environmental exposure was one of the plausible explanations. This study investigated changes in the association between childhood asthma and ambient air pollution occurring over time. METHOD: A nationwide questionnaire survey concerning respiratory illness and symptoms was administered to Taiwanese elementary and middle school students in 2011 and repeatedly in 2016-2017. During the study period, the concentrations of ambient air pollutants were obtained from the Environmental Protection Administration (EPA) monitoring stations. Generalized estimating equation models were applied to examine the association between air pollution in the past year and the risk of current asthma. RESULTS: A total of 6346 children from the 2011 survey and 11 585 children from the 2016-2017 survey attended schools located within a 1-km radius of Taiwan EPA monitoring stations. The prevalence of childhood current asthma (children with physician-diagnosed asthma and persistent asthma symptoms in the past year) increased from 7.5% to 9.6% during this period. The level of exposure to particulate matter with an aerodynamic diameter of ≤2.5 µm (PM2.5 ) in the past year was found to be associated with current asthma both in the 2011 survey (odds ratio (OR): 1.90, 95% confidence interval (CI): 1.41-2.57) and in the 2016-2017 survey (OR: 1.24, 95% CI: 1.04-1.48). CONCLUSION: Improved air quality has reduced the effect of PM2.5 on childhood asthma, but air quality remains a health concern in Taiwan.

Occupational Hazard Exposures and Depressive Symptoms of Pregnant Workers.

OBJECTIVES: The aim of this study was to explore the prevalence of exposure to occupational hazards and depressive mood with associated underlying risk factors among pregnant workers. METHODS: Women at 12 weeks of gestation (n = 172) were recruited during regular prenatal screening. Data were obtained via questionnaires that explored job details and Edinburgh Postnatal Depression Scale. RESULTS: The most commonly encountered hazard was prolonged standing. The majority of women reported that the workplace provided no information on the safety or rights of pregnant women, but those exposed to at least four hazards had more access to such services (P < 0.05). Thirteen percent may have suffered from depressive symptomatology. Higher-level work-related burnout, lower job control, and reduced workplace support were significantly associated with possible antenatal depressive symptoms. CONCLUSION: Pregnant workers are exposed to substantial levels of occupational hazards and may experience depressive symptoms; thus, their work conditions require monitoring and improvement.

Lifetime exposure to particulate air pollutants is negatively associated with lung function in non-asthmatic children.

BACKGROUND: Pulmonary function is known to be affected by acute and subacute exposure to ambient air pollution. However, the impacts of lifetime exposure to air pollution on the pulmonary function of children have been inconsistent. The present study investigated the impact of lifetime residential exposure to intermediate levels of air pollution on the pulmonary function of schoolchildren. METHODS: In 2011, a survey of children aged 6-15 years was conducted in 44 schools in Taiwan. Atopic history, residential history, and environmental factors were recorded. Spirograms were obtained from a random sample of children without asthma. A total of 535 girls and 481 boys without a history of asthma were enrolled. Lifetime residential exposure to air pollutants, including particulate matter with an aerodynamic diameter less than 10 µm (PM10), ozone (O3), sulfur dioxide (SO2), nitrogen dioxide (NO2), and carbon monoxide (CO), was estimated using the kriging method, based on monitored data from the Taiwan Environmental Protection Administration. Multiple linear regression was used to analyze the association between lifetime air pollution exposure and pulmonary function, after adjustment for potential confounders and recent exposure. RESULTS: After adjustment for 7-day average air pollutant levels, a 10 µg/m3 increase in PM10 was related to reductions in the forced expiratory volume in 1 s (-2.00%; 95% confidence interval [CI] -3.09% to -0.90%), forced vital capacity (-1.86%; CI: -2.96% to -0.75%), and maximal midexpiratory flow (-2.28%; CI: -4.04% to -0.51%). These associations were independent of the other pollutants. CONCLUSION: Lifetime exposure to 25-85 µg/m3 of PM10 has negative impacts on the pulmonary function of children.

Synthesis, X-ray Structure, Optical, and Electrochemical Properties of a White-Light-Emitting Molecule.

A new white-light-emitting molecule (1) was synthesized and characterized by NMR spectroscopy, high resolution mass spectrometry, and single-crystal X-ray diffraction. Compound 1 crystallizes in the orthorhombic space group Pnma, with a = 12.6814(6), b = 7.0824(4), c = 17.4628(9) Å, α = 90°, ß = 90°, γ = 90°. In the crystal, molecules are linked by weak intermolecular C-H···O hydrogen bonds, forming an infinite chain along [100], generating a C(10) motif. Compound 1 possesses an intramolecular six-membered-ring hydrogen bond, from which excited-state intramolecular proton transfer (ESIPT) takes place from the phenolic proton to the carbonyl oxygen, resulting in a tautomer that is in equilibrium with the normal species, exhibiting a dual emission that covers almost all of the visible spectrum and consequently generates white light. It exhibits one irreversible one-electron oxidation and two irreversible one-electron reductions in dichloromethane at modest potentials. Furthermore, the geometric structures, frontier molecular orbitals (MOs), and the potential energy curves (PECs) for 1 in the ground and the first singlet excited state were fully rationalized by density functional theory (DFT) and time-dependent DFT calculations. The results demonstrate that the forward and backward ESIPT may happen on a similar timescale, enabling the excited-state equilibrium to be established.

Using wavelet transform and fuzzy neural network for VPC detection from the Holter ECG.

A novel method for detecting ventricular premature contraction (VPC) from the Holter system is proposed using wavelet transform (WT) and fuzzy neural network (FNN). The basic ideal and major advantage of this method is to reuse information that is used during QRS detection, a necessary step for most ECG classification algorithm, for VPC detection. To reduce the influence of different artifacts, the filter bank property of quadratic spline WT is explored. The QRS duration in scale three and the area under the QRS complex in scale four are selected as the characteristic features. It is found that the R wave amplitude has a marked influence on the computation of proposed characteristic features. Thus, it is necessary to normalize these features. This normalization process can reduce the effect of alternating R wave amplitude and achieve reliable VPC detection. After normalization and excluding the left bundle branch block beats, the accuracies for VPC classification using FNN is 99.79%. Features that are extracted using quadratic spline wavelet were used successfully by previous investigators for QRS detection. In this study, using the same wavelet, it is demonstrated that the proposed feature extraction method from different WT scales can effectively eliminate the influence of high and low-frequency noise and achieve reliable VPC classification. The two primary advantages of using same wavelet for QRS detection and VPC classification are less computation and less complexity during actual implementation.