Electrical injuries in children-a 6-year retrospective study.

BACKGROUND: This study aimed to assess the clinical epidemiological characteristics of children with electrical injuries and discuss the countermeasures for the prevention of electrical injuries in children. METHODS: The children with electrical injuries were grouped according to whether or not they were admitted to the hospital for treatment into inpatient and outpatient groups. Clinical data such as gender, causes of injury and injury-causing voltage distribution in different age groups were analyzed. The factors affecting hospitalization were subjected to χ2 test, Kruskal-Wallis H test, and logistic regression analysis. RESULTS: A total of 321 children were included with 37 divided into inpatient group and 284 divided into outpatient group. The incidence of electrical injuries was highest in children ≤6 years old and in the summer. There were significantly different in gender, place of occurrence, cause of injury and injury-causing voltage between the two groups (p < 0.05). Injury-causing voltage is an independent risk factor affecting hospitalization of children with electrical injuries (OR = 0.116, 95 %CI = 0.040-0.334, p = 0.000). In children ≤6 years old, boys suffered electrical injuries more frequently than girls; battery powered vehicle (47.53 %) was primarily the cause of injury; most of the patients (64.64 %) were exposed to low voltage below 100 Vs, mainly in the case of adolescent children. CONCLUSION: Male preschoolers accounted for the majority of electrical injury cases, and these accidents mostly happened in household electrical appliances and household battery cars. Overall, it is necessary to improve family electrical safety education and reinforce protective measures against electric injury to children.

O6-methylguanine DNA methyltransferase is upregulated in malignant transformation of gastric epithelial cells via its gene promoter DNA hypomethylation.

BACKGROUND: O6-methylguanine-DNA methyltransferase (MGMT) is a suicide enzyme that repairs the mispairing base O6-methyl-guanine induced by environmental and experimental carcinogens. It can transfer the alkyl group to a cysteine residue in its active site and became inactive. The chemical carcinogen N-nitroso compounds (NOCs) can directly bind to the DNA and induce the O6-methylguanine adducts, which is an important cause of gene mutation and tumorigenesis. However, the underlying regulatory mechanism of MGMT involved in NOCs-induced tumorigenesis, especially in the initiation phase, remains largely unclear. AIM: To investigate the molecular regulatory mechanism of MGMT in NOCs-induced gastric cell malignant transformation and tumorigenesis. METHODS: We established a gastric epithelial cell malignant transformation model induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) or N-methyl-N-nitroso-urea (MNU) treatment. Cell proliferation, colony formation, soft agar, cell migration, and xenograft assays were used to verify the malignant phenotype. By using quantitative real-time polymerase chain reaction (qPCR) and Western blot analysis, we detected the MGMT expression in malignant transformed cells. We also confirmed the MGMT expression in early stage gastric tumor tissues by qPCR and immunohistochemistry. MGMT gene promoter DNA methylation level was analyzed by methylation-specific PCR and bisulfite sequencing PCR. The role of MGMT in cell malignant transformation was analyzed by colony formation and soft agar assays. RESULTS: We observed a constant increase in MGMT mRNA and protein expression in gastric epithelial cell malignant transformation induced by MNNG or MNU treatment. Moreover, we found a reduction of MGMT gene promoter methylation level by methylation-specific PCR and bisulfite sequencing PCR in MNNG/MNU-treated cells. Inhibition of the MGMT expression by O6-benzylguanine promoted the MNNG/MNU-induced malignant phenotypes. Overexpression of MGMT partially reversed the cell malignant transformation process induced by MNNG/MNU. Clinical gastric tissue analysis showed that MGMT was upregulated in the precancerous lesions and metaplasia tissues, but downregulated in the gastric cancer tissues. CONCLUSION: Our finding indicated that MGMT upregulation is induced via its DNA promoter hypomethylation. The highly expressed MGMT prevents the NOCs-induced cell malignant transformation and tumorigenesis, which suggests a potential novel approach for chemical carcinogenesis intervention by regulating aberrant epigenetic mechanisms.

SARS-CoV-2-Triggered Mast Cell Rapid Degranulation Induces Alveolar Epithelial Inflammation and Lung Injury

SARS-CoV-2 infection-induced hyper-inflammation links to the acute lung injury and COVID-19 severity. Identifying the primary mediators that initiate the uncontrolled hypercytokinemia is essential for treatments. Mast cells (MCs) are strategically located at the mucosa and beneficially or detrimentally regulate immune inflammations. Here we showed that SARS-CoV-2-triggeed MC degranulation initiated alveolar epithelial inflammation and lung injury. SARS-CoV-2 challenge induced MC degranulation in ACE-2 humanized mice and rhesus macaques, and a rapid MC degranulation could be recapitulated with Spike-RBD binding to ACE2 in cells; MC degranulation alterred various signaling pathways in alveolar epithelial cells, particularly, led to the production of pro-inflammatory factors and consequential disruption of tight junctions. Importantly, the administration of clinical MC stabilizers for blocking degranulation dampened SARS-CoV-2-induced production of pro-inflammatory factors and prevented lung injury. These findings uncover a novel mechanism for SARS-CoV-2 initiating lung inflammation, and suggest an off-label use of MC stabilizer as immunomodulators for COVID-19 treatments. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=135 SRC="FIGDIR/small/449680v1_ufig1.gif" ALT="Figure 1"> View larger version (29K): org.highwire.dtl.DTLVardef@899996org.highwire.dtl.DTLVardef@1c26c0eorg.highwire.dtl.DTLVardef@1442cdcorg.highwire.dtl.DTLVardef@dd4204_HPS_FORMAT_FIGEXP M_FIG C_FIG In BriefSARS-CoV-2 triggers an immediate mast cell (MC) degranulation, which initiates the alveolar epithelial inflammation and disrupts the tight junction. MC stabilizers that block degranulation reduce virus-induced lung inflammation and injury. HighlightsO_LIThe binding of RBD of Spike protein of SARS-CoV-2-to ACE2 receptor protein triggers an immediate MC degranulation C_LIO_LIMC degranulation induces transcriptomic changes include an upregulated inflammatory signaling and a downregulated cell-junction signaling C_LIO_LIMC degranulation leads to alveolar epithelial inflammation and disruption of tight junctions C_LIO_LIMC stabilizer that inhibits degranulation reduces SARS-CoV-2-induced lung inflammation and injury in vivo C_LI

Association between Lipoprotein (a) Levels and Metabolic Syndrome in a Middle-aged and Elderly Chinese Cohort.

OBJECTIVE: The association between lipoprotein (a) [Lp(a)] levels and metabolic syndrome (MetS) remains uncertain, especially in the Asian population. The purpose of this study was to demonstrate the association between Lp(a) levels and MetS in a middle-aged and elderly Chinese cohort. METHODS: A cross-sectional study of 10,336 Chinese adults aged 40 years or older was conducted in Jiading District, Shanghai, China. Logistic regression analysis was used to evaluate the association between serum Lp(a) levels and MetS. RESULTS: In the overall population, 37.5% of participants had MetS. Compared with individuals in the lowest quartile of serum Lp(a) levels, those in the highest quartile had a lower prevalence of MetS (30.9% vs. 46.9%, P for trend < 0.0001). Multivariate logistic regression analyses showed that compared with participants in the bottom quartile of serum Lp(a) levels, those in the top quartile had decreased odds ratio (OR) for prevalent MetS [multivariate-adjusted OR 0.45 (95% confidence interval 0.39-0.51); P < 0.0001]. Additionally, Lp(a) level was conversely associated with the risk of central obesity, high fasting glucose, high triglycerides, and low HDL cholesterol, but not with hypertension. Stratified analyses suggested that increasing levels of Lp(a) was associated with decreased risk of MetS in all the subgroups. CONCLUSION: Serum Lp(a) level was inversely associated with the risk of prevalent MetS in a middle-aged and elderly Chinese cohort.

An oriental melon 9-lipoxygenase gene CmLOX09 response to stresses, hormones, and signal substances.

In plants, lipoxygenases (LOXs) play a crucial role in biotic and abiotic stresses. In our previous study, five 13-LOX genes of oriental melon were regulated by abiotic stress but it is unclear whether the 9-LOX is involved in biotic and abiotic stresses. The promoter analysis revealed that CmLOX09 (type of 9-LOX) has hormone elements, signal substances, and stress elements. We analyzed the expression of CmLOX09 and its downstream genes-CmHPL and CmAOS-in the leaves of four-leaf stage seedlings of the oriental melon cultivar "Yumeiren" under wound, hormone, and signal substances. CmLOX09, CmHPL, and CmAOS were all induced by wounding. CmLOX09 was induced by auxin (indole acetic acid, IAA) and gibberellins (GA3); however, CmHPL and CmAOS showed differential responses to IAA and GA3. CmLOX09, CmHPL, and CmAOS were all induced by hydrogen peroxide (H2O2) and methyl jasmonate (MeJA), while being inhibited by abscisic acid (ABA) and salicylic acid (SA). CmLOX09, CmHPL, and CmAOS were all induced by the powdery mildew pathogen Podosphaera xanthii. The content of 2-hexynol and 2-hexenal in leaves after MeJA treatment was significantly higher than that in the control. After infection with P. xanthii, the diseased leaves of the oriental melon were divided into four levels-levels 1, 2, 3, and 4. The content of jasmonic acid (JA) in the leaves of levels 1 and 3 was significantly higher than that in the level 0 leaves. In summary, the results suggested that CmLOX09 might play a positive role in the response to MeJA through the hydroperoxide lyase (HPL) pathway to produce C6 alcohols and aldehydes, and in the response to P. xanthii through the allene oxide synthase (AOS) pathway to form JA.

Expression and clinical significance of periostin in oral lichen planus.

Oral lichen planus (OLP) is a chronic inflammatory lesion involving the oral mucosa, which has a high likelihood of progressing to cancer. The present study investigated the periostin expression in the mucosa and serum of patients with OLP and its correlation with serum cytokines. A total of 117 patients with OLP and 110 healthy controls were included in the study. The protein expression of periostin were measured in the OLP and normal oral mucosa by immunohistochemistry. ELISA was performed to measure the serum levels of periostin, tumour necrosis factor-α (TNF-α), interleukin (IL)-6, interferon-γ (IFN-γ), IL-4 and thymic stromal lymphopoietin (TSLP). Compared with the control group the OLP group had a significantly increased number of cases with high periostin expression in the oral mucosa and a significantly increased serum periostin level (P<0.05). Among all 117 OLP subjects, high periostin expression was associated with higher serum IL-6, TNF-α, TSLP and tissue mast cell density. High periostin expression was also significantly associated with a lower IFN-γ/IL-4 ratio (P<0.05). The present study concluded that periostin expression was increased in the oral mucosa and serum of patients with OLP and was associated with inflammatory response, T helper 2 cytokine-predominant immune imbalance, increased mast cell count and TSLP. The modulation of periostin may represent an attractive novel therapeutic target.

Nitric oxide induced by polyamines involves antioxidant systems against chilling stress in tomato (Lycopersicon esculentum Mill.) seedling.

Polyamines (PAs) and nitric oxide (NO) are vital signals in modulating plant response to abiotic stress. However, to our knowledge, studies on the relationship between NO and PAs in response to cold stress in tomato are limited. Accordingly, in this study, we investigated the effects of putrescine (Put) and spermidine (Spd) on NO generation and the function of Spd-induced NO in the tolerance of tomato seedling under chilling stress. Spd increased NO release via the nitric oxide synthase (NOS)-like and nitrate reductase (NR) enzymatic pathways in the seedlings, whereas Put had no such effect. Moreover, H2O2 might act as an upstream signal to stimulate NO production. Both exogenous NO donor (sodium nitroprusside (SNP)) and Spd enhanced chilling tolerance in tomato, thereby protecting the photosynthetic system from damage. Compared to chilling treatment alone, Spd enhanced the gene expressions of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and their enzyme activities in tomato leaves. However, a scavenger or inhibitor of NO abolished Spd-induced chilling tolerance and blocked the increased expression and activity due to Spd of these antioxidant enzymes in tomato leaves under chilling stress. The results showed that NO induced by Spd plays a crucial role in tomato's response to chilling stress.

[Bioconversion of cellulose to methane by a consortium consisting of four microbial strains].

Cellulose was usually degraded by microbial communities in natural habitats. Construction of a simple cellulolytic consortium is necessary to understand the underlying interaction within microorganisms involved in cellulose conversion. A screening approach was developed to obtain a simple microbial community with the ability of cellulose degradation to methane. This technique was based on the method of enrichment culture accompanying with denaturing gel gradient electrophoresis (DGGE) fingerprint detection technology and roll-tube method. Moreover, a four-strain mixed culture capable of degrading cellulose to methane was isolated from Zoige alpine wetland of the Tibetan Plateau. The results showed that the microbial consortia consisted of three functional groups: the cellulolytic bacterium Clostridium glycolicum, the non-celluloytic bacteria group of Trichococcus flocculiformis and Parabacteroides merdae, and the methanogenic bacterium Methanobacterium subterraneum. This four-strain co-culture can convert cellulose to methane. In the future, the isolated cellulolytic consortia could provide a platform for controlling metabolic pathways and genetic modification involved in methane production from cellulose.

[Regulation of different calcium forms on the photosynthesis of tomato leaves under heat stress].

The regulation of different calcium forms, namely CaCl2, Nano-calcium and Manntiol-calcuim, on the gas exchange and fluorescence of tomato leaves under heat stress was investigated. The results showed that all forms of calcium alleviated the decrease of chlorophyll a and carotenoid contents in leaves of tomato seedlings under heat stress, enhanced the net photosynthesis rate (Pn), transpiration rate (Tr) and stomatal conductance (g(s)) to varying degrees, reduced the quantum yield of non-regulated energy dissipation [Y(NO)] of PSII and quantum yield of non-photochemical energy dissipation in PSI due to acceptor side limitation [Y(NA)], promoted the regulated energy dissipation [Y(NPQ)] and quantum yield of non-photochemical energy dissipation in PSI due to donor side limitation [Y(ND)], and increased the calcium content in leaves. Generally, manntiol-calcium and nano-calcium were more effective than CaCl2, and more suitable to enhance the photosynthesis of leaves oftomato seedlings under heat stress.

[Comparison between transgenic insect-resistant cotton expressing Cry1Ac protein and its parental variety in rhizospheric fungal diversity].

The dynamics of rhizospheric fungal diversity and biomass at different sampling stages associated with two transgenic insectresistant cottons expressing Cry1Ac protein and their control varieties were studied under greenhouse conditions, followed by PCR-denaturing gradient gel electrophoresis (PCR-DGGE) and quantitative real-time polymerase chain reaction (Q-PCR), in order to evaluate the ecological security of planting transgenic cotton expressing Cry1Ac protein. The results indicated that the fungal superior bands in rhizosphere of transgenic Bt cotton were similar with that of control cotton at four sampling stages, the more obvious difference in the blurred bands among transgenic Bt cotton, JM20 and SHIYUAN321 was detected. The rhizospheric fungal biomass of transgenic Bt cotton SGK321 was significantly lower than that of its parental control cotton at seedling stage, while the slight decrease in fungal biomass of transgenic Bt cotton XP188 was detected at boll forming stage, the ill-defined decrease, even growing tendency in two transgenic Bt cottons was detected at other stages. However, the difference of rhizospheric fungal community compositions and biomass was not only existed between transgenic cotton and its control, but also between SHIYUAN321 and JM20, and the same phenomenon was also detected between transgenic Bt cotton SGK321 and XP188. Hence, Bt protein is not the only incentive resulting in the difference in fungal community composition and diversity, the decrease in biomass between transgenic cotton and untransgenic cotton, different cotton varieties has an effect on them.

[Microbial community structure analysis of unexploited oil and gas fields by PCR-DGGE].

Microbial communities of different depths (30, 60, 100, 150, 200cm) from the unexploited oilfield, gas field and control area were studied by PCR-DGGE and sequencing methods. The objectives of this study were to understand the microbial distribution in the regions of unexploited oil and gas fields, and to investigate the potential microbial indicators of oil and gas resources. The results showed that the Dice coefficients between different depths were very low (26-69.9). The microbial communities in the soil of 150 cm and 200 cm depth had greater richness (S > or = 19), diversity (H > or = 2.69) and evenness (E > or = 0. 90). The results of sequencing demonstrated that the bands from oilfield were mainly grouped into alpha-Proteobacteria, gamma-Proteobacteria, Actinobacteria, Acidobacteria with the predominance of gamma-Proteobacteria (75%). Most of the bands were related to oil-associated and hydrocarbon degrading bacteria, such as Methylophaga and Alcanivorax. While the gas field had alpha, beta, gamma, delta-Proteobacteria and Bacteroidetes, and gamma-Proteobacteria accounted for only 24%. More strains showed relativity to methanotrophs, such as Methylocystaceae. Thus, 150 cm and 200 cm were more suitable as the oil-gas exploration sampling depth. Methylocystaceae may act as potential indicators for gas resources, Methylophaga and Alcanivorax for oil.

Grafting helps improve photosynthesis and carbohydrate metabolism in leaves of muskmelon.

The most important quality for muskmelon (Cucumis melo L.) is their sweetness which is closely related to the soluble sugars content. Leaves are the main photosynthetic organs in plants and thus the source of sugar accumulation in fruits since sugars are translocated from leaves to fruits. The effects of grafting muskmelon on two different inter-specific (Cucurbita maxima×C. moschata) rootstocks was investigated with respect to photosynthesis and carbohydrate metabolism. Grafting Zhongmi1 muskmelon on RibenStrong (GR) or Shengzhen1 (GS) rootstocks increased chlorophyll a, chlorophyll b and chlorophyll a+b content and the leaf area in middle and late developmental stages of the plant compared to the ungrafted Zhongmi1 check (CK). Grafting enhanced the net photosynthesis rate, the stomatal conductance, concentration of intercellular CO(2) and transpiration rate. Grafting influenced carbohydrates contents by changing carbohydrate metabolic enzymes activities which was observed as an increase in acid invertase and neutral invertase activity in the functional leaves during the early and middle developmental stages compared to CK. Grafting improved sucrose phosphate synthase and stachyose synthase activities in middle and late developmental stages, thus translocation of sugars (such as sucrose, raffinose and stachyose) in GR and GS leaves were significantly enhanced. However, compared with CK, translocation of more sugars in grafted plants did not exert feedback inhibition on photosynthesis. Our results indicate that grafting muskmelon on inter-specific rootstocks enhances photosynthesis and translocation of sugars in muskmelon leaves.

[Distribution patterns of heavy metals in surface sediments of the Yangtze estuary and its adjacent areas and environmental quality assessment].

The concentrations of six heavy metals were determined in the fine fraction ( < 63 microm) of surface sediments in the Yangtze Estuary and its adjacent areas by an inductively coupled plasma mass spectroscopy (ICP-MS). The average contents of As, Cd, Cu, Pb, Cr and Zn are 10.47, 0.19, 37.68, 36.86, 97.80 and 98.65 mg x kg(-1), respectively. The contents of As, Cd and Cu appear gradually degressive from west to east, while the contents of Pb, Cr and Zn appear no apparent difference. In generally, the concentrations of heavy metals are higher in the south sea areas than those in the north sea areas. Environmental assessment with single factor method suggests that As, Cu, Pb, Cr and Zn are moderately contaminated, while Cd is not polluted. The values of As,Cu and Cr are between effect range-low (ERL) and effect range-median (ERM), which indicate they occasionally bring adverse biological effect at most stations, and the values of Cd,Pb and Zn are below ERL mean they rarely bring adverse biological effect by sediment quality guidelines assessment. From the results of factor analysis and cluster analysis, we conclude that the outer sea areas of the Yangtze Estuary and the Hangzhou Bay have lower sediment environmental quality, therefore much attention should be paid to these areas.

[Biosorption of Ag+ by heavy metals hyperresistant Bacillus cereus strain HQ-1].

A newly isolated Bacillus cereus strain HQ-1 was found to possess high capability to absorb silver ions. The study showed that the biosorption process could be described well by pseudo-second-order kinetic model and Freundlich isotherm model. Higher cell concentration was favorable to the biosorption. Temperature's effect on the biosorption was not obvious. The oxygenous and nitrogenous functional groups on the cell wall played a very important role in the process of biosorption. Microdeposits were formed by interaction between silver ions and biopolymers from the cell wall (such as polysaccharides, proteins and some hydrolysis).

Detection, isolation, and identification of cadmium-resistant bacteria based on PCR-DGGE.

This study focused on the screening of cadmium-resistant bacterial strains from Pb-Zn tailing. We investigated the diversity of microbial community inhabiting Dong-san-cha Pb-Zn tailing in Beijing, China, by polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene of bacterial strain, and found two dominant strains in the DGGE profile. Using special culture media, we isolated two strong cadmium-resistant bacterial strains. On the basis of morphological, physiological, and biochemical characteristics, BIOLOG, and 16S rDNA sequencing, the two strains were identified as Bacillus cereus and Enterobacter cloacae. Minimal inhibitory concentrations (MICs) of heavy metals for the bacteria were determined. E. cloacae showed higher MIC values for heavy metals and a larger range of antibiotic resistance than B. cereus.

Bacterial diversity in soils around a lead and zinc mine.

Five samples of soil collected from a lead and zinc mine were used to assess the effect of combined contamination of heavy metals on soil bacterial communities using a polyphasic approach including characterization of isolates by culture method, community level catabolic profiling in BIOLOG GN microplates, and genetic community fingerprinting by denaturing gradient gel electrophoresis of 16S rDNA fragments amplified by PCR from community DNA (PCR-DGGE). The structure of the bacterial community was affected to a certain extent by heavy metals. The PCR-DGGE analysis of 16S rRNA genes showed that there were significant differences in the structure of the microbial community among the soil samples, which were related to the contamination levels. The number of bacteria and the number of denaturing gradient gel electrophoresis (DGGE) bands in the soils increased with increasing distance from the lead and zinc mine tailing, whereas the concentration of lead (Pb) and cadmium (Cd) was decreased. Heavily polluted soils could be characterized by a community that differs from those of lightly polluted soils in richness and structure of dominating bacterial populations. The clustering analysis of the DGGE profiles showed that the bacteria in all the five samples of soil belonged to three clusters. The data from the BIOLOG analysis also showed the same result. This study showed that heavy metal contamination decreased both the biomass and diversity of the bacterial community in soil.

[Isolation, molecular characterization and resistance mechanism study on a cadmium hyperresistant Bacillus cereus].

A Gram-positive, aerobic, motile, spore-forming bacterium was isolated from a Pb-Zn mine tailing at suburb of Beijing City. The bacterial strain isolated could resist cadmium efficiently and it was able to grow well on media plates containing 1 000 mg/L cadmium. The DNA G + C content were found to be 60%. Phylogenetic analysis of the 16S rRNA gene revealed that this isolate was a member of the genus Bacillus. Two growth curves about this strain were drawn on media with and without cadmium. This strain harbors a plasmid putatively bearing essential cadmium resistant genes as demonstrated by a plasmid elimination experiment. The results of this study indicate that this strain has a better potential for cadmium resistance compared to other reports. The physiological characterization of the isolates also indicates the possible application of this strain for bioremediation of sites contaminated with cadmium.

Localization of S genes on extended DNA fibers (EDFs) in Brassica oleracea by high-resolution FISH.

The compactness of plant chromosome and the structures of plant cell wall and cytoplasm pose a great resistance to fluorescence in situ hybridization (FISH), and consequently many new methods for improving spatial resolution are being exploited to overcome these problems. However, for plants with small chromosomes like rice and Brassica, there are still many difficulties. In this article a new and effective technique for preparation of extended DNA fibers (EDFs), using a series of treatments to prophase I chromosomes of Brassica oleracea PMCs, is presented. This technique allows longitudinal extension of the chromosomes 30-107 times longer than those of their metaphase counterparts. The length of the extended DNA fibers is between 89 microm and 273 microm, and the space resolution is 42.8-53.0 kb. Stretching ratios were assessed in a number of FISH experiments with super-stretched chromosomes from meiotic prophase I nuclei of B. olerecea. Through FISH to EDFs of pachytene chromosomes hybridized in situ with SRK (S-locus receptor kinase) and SPII (S-locus protein II) probes, for the first time we localized the accurate positions of S-locus and quantitatively analyzed the features of S genes in B. oleracea genome to show all S genes were single-copied. In addition, the length between two linked genes was measured to be about one micron. As a result, the highest space resolution which was about 4 kb was obtained.