cfDNA screening and diagnosis of monogenic disorders – where are we heading?

Cell-free fetal DNA analysis for non-invasive prenatal screening of fetal chromosomal aneuploidy has been widely adopted for clinical use. Fetal monogenic diseases have also been shown to be amenable to non-invasive detection by maternal plasma DNA analysis. A number of recent technological developments in this area has increased the level of clinical interest, particularly as one approach does not require customized reagents per mutation. The mutational status of the fetus can be assessed by determining which parental haplotype that fetus has inherited based on the detection of haplotype-associated SNP alleles in maternal plasma. Such relative haplotype dosage analysis requires the input of the parental haplotype information for interpretation of the fetal inheritance pattern from the maternal plasma DNA data. The parental haplotype information can be obtained by direct means, reducing the need to infer haplotypes using DNA from other family members. The technique also allows the assessment of complex mutations and has multiplexing capabilities where a number of genes and mutations can be assessed at the same time. These advantages allow non-invasive prenatal diagnosis of fetal monogenic diseases to be much more scalable. These applications may drive the next wave of clinical adoption of cell-free fetal DNA testing. © 2018 The Authors Prenatal Diagnosis Published by John Wiley & Sons Ltd     

Postnatal management and long-term outcome for survivors with congenital diaphragmatic hernia

Significant advances in the postnatal management of patients with congenital diaphragmatic hernia (CDH) have resulted in a remarkable improvement in survival rates over the past two decades. The success of current postnatal management of CDH patients has rendered fetal intervention to be limited to the most severe cases, and the role for prenatal treatment of CDH patients remains unclear. The adoption of lung-preserving strategies including high-frequency oscillatory ventilation (HFOV) and extracorporeal membrane oxygenation (ECMO) have improved CDH outcomes especially in those patients with significant ventilatory or circulatory compromise. Survival rates of up to 90% are being reported in some high-volume centers. However, the increased survival in CDH patients has been accompanied by an increase in neurological, nutritional and musculoskeletal morbidity among the long-term survivors. This has resulted in the need to provide resources for the long-term follow-up and support of this patient population. In this article, the postnatal management strategies and primary and secondary outcomes of high-volume international pediatric surgical centers will be reviewed. Finally, the role of a multidisciplinary management team for the follow-up of long-term CDH survivors will be discussed. Copyright © 2008 John Wiley & Sons, Ltd.     

Characterization of contamination in and toxicities of a shipyard area in Hong Kong

This is the first integrated study on the contaminant characterization and toxicities of a shipyard area. This site in Hong Kong contained 3.6-33.4 mg kg(-1) dichlorodiphenyltrichloroethane and 5-79 g kg(-1) oil and grease. Other pollutants exceeding the Dutch intervention values were total polyaromatic hydrocarbons, total petroleum hydrocarbons, and metals Cu, Pb and Zn. These pollutants persisted partially owing to the poor fertility with <125 mg N kg(-1) and <530 mg P kg(-1) typical of coastal soil. Sediments collected within 100 m also showed contamination exceeding the China and Hong Kong intervention levels. The shipyard soil killed two bacteria Pseudomonas stutzeri and Acinetobacter sp. isolated from a clean coastal soil, inhibited germination of three exogenous plants Triticum aestivum, Brassica chinense and Lolium perenne, and inhibited proliferation of three indigenous bacteria: Methylobacterium sp., Pseudomonas aeruginosa and Bacillus cereus. Thus, ex situ remediation was needed.     

Benefits of clean development mechanism application on the life cycle assessment perspective: a case study in the palm oil industry

This study performed an assessment on the beneficial of the Clean Development Mechanism (CDM) application on waste treatment system in a local palm oil industry in Malaysia. Life cycle assessment (LCA) was conducted to assess the environmental impacts of the greenhouse gas (GHG) reduction from the CDM application. Calculations on the emission reduction used the methodology based on AM002 (Avoided Wastewater and On-site Energy Use Emissions in the Industrial Sector) Version 4 published by United Nations Framework Convention on Climate Change (UNFCC). The results from the studies showed that the introduction of CDM in the palm oil mill through conversion of the captured biogas from palm oil mill effluent (POME) treatment into power generation were able to reduce approximate 0.12 tonnes CO2 equivalent concentration (tCO2e) emission and 30 kW x hr power generation per 1 tonne of fresh fruit bunch processed. Thus, the application of CDM methodology on palm oil mill wastewater treatment was able to reduce up to 1/4 of the overall environment impact generated in palm oil mill.     

Trace metals in mussels from mariculture zones, Hong Kong

In 1997, concentrations of cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb) and nickel (Ni) were analysed in green-lipped mussels (Perna viridis) from three mariculture zones located in the north-east (Kat O), south (Lo Tik Wan) and to the west (Ma Wan) of Hong Kong. Spatial differences in the concentration of metals were found, chromium and copper were higher at Ma Wan and Lo Tik Wan compared to Kat O in the north-east. In contrast, the highest levels of lead (mean = 4.37 microg/g dry wt) were recorded at Kat O. There were no differences in the level of nickel between the study sites. A comparison of the metal concentrations in mussels with the results of a previous study seven years before, in 1990, showed a twofold increase in the mean levels of cadmium for all three sites. However, levels of the other metals in 1997 were lower by 12-32% for chromium, 32-39% for copper and 24-25% for nickel. The greatest reductions were recorded for lead: Kat O (39%), Ma Wan (51%) and Lo Tik Wan (75%). This may be related to the introduction of lead-free petrol in 1991. Despite the apparent reduction in some heavy metal bioaccumulation between 1990 and 1997, from a public health risk perspective, the data suggest a continued need for monitoring of heavy metals in mussels from mariculture zones.     

Biohydrogen production by Clostridium butyricum and Rhodopseudomonas palustris in Co-cultures

This study evaluated biohydrogen production by co-culture of Clostridium butyricum and Rhodopseudomonas palustris. C. butyricum and R. palustris were grown separately and together as batch cultures. Hydrogen production, growth, NH₄-N, total volatile fatty acid production, and sucrose degradation were monitored. The hydrogen production of the co-culture produced 562 ml, R. palustris 426 ml, and C. butyricum 333 ml. The co-culture produced 2.16 mol H₂/mol sucrose, C. butyricum and R. palustris produced 1.77 and 1.64 mol H₂/mol sucrose, respectively. The co-culture was more efficient in the hydrogen production. Therefore, the co-culture is a good method for biohydrogen fermentation.     

Emission factor of exhaust gas constituents during the pyrolysis of zinc chloride immersed biosolid

Pyrolysis enables ZnCl₂ immersed biosolid to be reused, but some hazardous air pollutants are emitted during this process. Physical characteristics of biosolid adsorbents were investigated in this work. In addition, the constituents of pyrolytic exhaust were determined to evaluate the exhaust characteristics. Results indicated that the pyrolytic temperature was higher than 500 °C, the specific surface area was >900 m²/g, and the total pore volume was as much as 0.8 cm³/g at 600 °C. For non-ZnCl₂ immersed biosolid pyrolytic exhaust, VOC emission factors increased from 0.677 to 3.170 mg-VOCs/g-biosolid with the pyrolytic temperature increase from 400 to 700 °C, and chlorinated VOCs and oxygenated VOCs were the dominant fraction of VOC groups. VOC emission factors increased about three to seven times, ranging from 1.813 to 21.448 mg/g for pyrolytic temperatures at 400–700 °C, corresponding to the mass ratio of ZnCl₂ and biosolid ranging from 0.25–2.5.     

Partitioning Gas Tracer Tests for Measurement of Water in Municipal Solid Waste

Abstract

A key component in the operation of almost all bioreactor landfills is the addition of water to maintain optimal moisture conditions. To determine how much water is needed and where to add it, in situ methods are required to measure water within solid waste. Existing technologies often result in measurements of unknown accuracy, because of the variability of solid waste materials and time-dependent changes in packing density, both of which influence most measurement methods. To overcome these problems, a new technology recently developed by hydrologists for measuring water in the vadose zone—the partitioning gas tracer test—was tested. In this technology, the transport behavior of two gas tracers within solid waste is used to measure the fraction of the void space filled with water. One tracer is conservative and does not react with solids or liquids, while a second tracer partitions into the water and is separated from the conservative tracer during transport. This technology was tested in four different solid waste packings and was capable of determining the volumetric water content to within 48% of actual values, with most measurement errors less than 15%. This technology and the factors that affect its applicability to landfills are discussed in this paper.     

An overview on the properties of eco-friendly concrete paving blocks incorporating selected waste materials as aggregate

Environmental Science and Pollution Research - Paving block is a widely used pavement material due to its long service life, fast and easy production and easily replaced for maintenance purpose....