A Judgment of Attribution of Increase in Urine β_2-Microglobulin after Environmental Cadmium Exposure

Urineβ_2-microglobulin (β_2-m) was measured in 433 persons with low-level, long-term environmental exposure to Cd, and in 124 control persons from unpolluted area. In 152 of the exposed persons, and some of the controls, the urine β-m exceeded the limit. Of the 433 exposed persons, 74 cases with both urine Cd and β_2-m exceeding the limit were matched by the control. This study suggests that after the stratification of the degrees of renal tubular injury according to the fractional β_2-m excretion (FE β_2-m) and coordination of clinical examination, FE β_2-m could contribute to identifying renal tubular dysfunction due to Cd exposure and kidney lesion when both Cd exposure and original nephropathy exist.

Comparative transcriptomics provide new insights into the mechanisms by which foliar silicon alleviates the effects of cadmium exposure in rice

Silicon(Si)has been shown to alleviate Cd stress in rice.Here,we investigated the beneficial effects of foliar Si in an indica rice Huanghuazhan(HHZ).Our results showed that foliar Si in-creases the dry weight and decreases Cd translocation in Cd-exposed rice at the grain-filling stage only,implying that the filling stage is critical for foliar Si to reduce Cd accumulation.We also investigated the transcriptomics in flag leaves(FLs),spikelets(SPs),and node Is(NIs)of Cd-exposed HHZ after foliar Si application at the filling stage.Importantly,the gene expression profiles associated with the Si-mediated alleviation of Cd stress were tissue spe-cific,while shared pathways were mediated by Si in Cd-exposed rice tissues.Furthermore,after the Si treatment of Cd-exposed rice,the ATP-binding cassette(ABC)-transporters were mostly upregulated in FL and SP,while the bivalent cation transporters were mostly down-regulated in FL and NI,possibly helping to reduce Cd accumulation.The genes associated with essential nutrient transporters,carbohydrate and secondary metabolite biosynthesis,and cytochrome oxidase activity were mostly upregulated in Cd-exposed FL and SP,which may help to alleviate oxidative stress and improve plant growth under Cd exposure.Inter-estingly,genes responsible for signal transduction were negatively regulated in FL,but pos-itively regulated in SP,by foliar Si.Our results provide transcriptomic evidence that foliar Si plays an active role in alleviating the effects of Cd exposure in rice.In particular,foliar Si may alter the expression pattern of genes associated with transport,biosynthesis and metabolism,and oxidation reduction.

Application of machine learning algorithms to screen potential biomarkers under cadmium exposure based on human urine metabolic profiles

Exposure to environmental cadmium increases the health risk of residents.Early urine metabolic detection using high-resolution mass spectrometry and machine learning algorithms would be advantageous to predict the adverse health effects.Here,we conducted machine learning approaches to screen potential biomarkers under cadmium exposure in 403 urine samples.In positive and negative ionization mode,4207 and 3558 features were extracted,respectively.We compared seven machine learning algorithms and found that the extreme gradient boosting(XGBoost)and random forest(RF)classifiers showed better accuracy and predictive performance than others.Following 5-fold cross-validation,the value of area under curve(AUC)was both 0.93 for positive and negative ionization modes in XGBoost classifier.In the RF classifier,AUC were 0.80 and 0.84 for positive and negative ionization modes,respectively.We then identified a biomarker panel based on XGBoost and RF classifiers.The incorporation of machine learning models into urine analysis using high-resolution mass spectrometry could allow a convenient assessment of cadmium exposure.

Exposure of silver carp (Hypophthalmichthys molitrix) to environmentally relevant levels of cadmium:hematology,muscle physiology,and implications for stock enhancement in the Xiangjiang River (Hunan,China)

Cadmium is a non-essential metal with a wide distribution that has severe toxic effects on aquatic animals. Changes in hematology and muscle physiology were examined in silver carp (Hypophthalmichthys molitrix) exposed to environmentally relevant levels of cadmium (0.01 mg L-1 ) for 96 h. Cadmium exposure induced significant increases in the red blood cell count, and in the plasma concentrations of cortisol, glucose, and lactate. This suggests that the dose of cadmium was sufficient to cause stress, possibly associated with impaired gas exchange at the gills. There were no changes in hemoglobin concentration or plasma protein concentration. Significant decreases in muscle energy fuels (ATP and glycogen), and increases in muscle lactate persisted until the end of the exposure period, respectively. The changes in muscle lactate and protein in silver carp differed from those observed in response to exposure of fish to cadmium and heavy metals in other studies. The study highlights the importance of selecting unpolluted release sites with suitable water conditions for the survival of newly released individuals for stock enhancement of the Xiangjiang River.

Cadmium in soybeans and the relevance to human exposure

Introduction Cadmium is considered a human carcinogen by the International Agency for Research on Cancer（IARC,1993）and the US National Toxicology Program（NTP,1997）.Cadmium contamination of food crops is a persistent issue for both the agricultural industry as well as consumers.This is an issue for agriculture because cadmium can be present in soils naturally or as a result of industrial processes and can contaminate foods that are consumed by humans.Industrial

Molecular cloning,sequencing,and expression profiles of heat shock protein 90 (HSP90) in Hyriopsis cumingii exposed to different stressors:Temperature,cadmium and Aeromonas hydrophila

Heat shock protein 90(HSP90)represents a suite of highly conserved and multi-functional molecular chaperone proteins that play an important role in cellular stress responses.In order to better understand the expression of HSP90 in mollusks,a full-length complementary DNA(cDNA)of HSP90(HcHSP90)was identified in Hyriopsis cumingii.HcHSP90 cDNA was 2659 bp in length,consisting of 30 and 50-untranslated regions and an open reading frame of 2187 bp,that encoded a 728 amino acid protein.Homology analyses showed that the HcHSP90 protein was highly conserved and had 5 well-conserved family signatures of HSP90 proteins.HcHSP90 mRNA expressed in various tissues of H.cumingii.The expression level of HcHSP90 was the highest in the digestive gland.In all tissues,with the exception of the digestive gland where it was down-regulated,HcHSP90 mRNA expression was significantly induced by temperature treatments(0,5,25,and 35℃)relative to the control(15℃).Exposure of H.cumingii to different concentrations of cadmium(50,100,and 200 mg/L),up-regulated HcHSP90 mRNA in the haemolymph and gill but without an obvious dose-dependent response.When H.cumingii were infected with Aeromonas hydrophila,HcHSP90 mRNA expression in the haemolymph was up-regulated and peaked 36 h post-infection,while in the gills it was significantly up-regulated 3 h post-infection in the gills,then remained constant until returning to pre-challenge expression levels at 36 h post-infection.The results show that HcHSP90 expression can be significantly regulated by changes in temperature,cadmium exposure and bacterial infection.We deduced that HSP90 may play an important role in helping H.cumingii to cope with environmental stress.