[Analysis of fast-growing culturable bacteria and pathogenic bacteria in the surface water of the northeast coast of Hainan Island in China]

Objective: To obtain the diversity and abundance of fast-growing bacteria in the surface water of the northeast coast of Hainan Island in China, different cultivation methods were employed. This study also aims to provide a reference for isolating bacterial samples from seawater sources and preventing marine-derived pathogens. Methods: Based on the principles of taxonomic design, surface seawater samples were collected from six locations along the northeast coast of Hainan Island in China in March, June, October, and December 2021. Then, bacterial enrichment was performed based on traditional cultivation methods for Salmonella, Vibrio, Burkholderia pseudomallei, Actinomycetes, and general marine bacteria. After that, bacterial species identification was conducted by 16S rDNA amplicon sequencing and metagenomic sequencing. Results: A total of 1 151 fast-growing cultivable bacteria belonging to 66 genera and 213 species were identified using five different culture protocols. In different cultivation protocols, Bacillus and Klebsiella demonstrated extensive discriminatory advantages and ranked among the top genera in terms of abundance. Protocol 1 had Escherichia, Klebsiella, and Citrobacter as dominant genera. Pathogenic bacteria detected by protocol 1 included Klebsiella pneumoniae and Escherichia coli, with 37 and 29 strains respectively, while Salmonella enterica was uniquely detected with seven isolates. Proteus, Enterococcus, and Providencia were the dominant genera in protocol 2, and Proteus mirabilis was the most abundant pathogenic bacteria detected with 66 isolates. Vibrio cholerae was uniquely detected with six isolates at a higher abundance. Klebsiella, Escherichia, and Acinetobacter were the dominant genera in protocol 3, and Klebsiella pneumoniae was the most abundant pathogenic bacteria detected with 53 isolates, while Acinetobacter nosocomialis was uniquely detected with seven isolates. Vibrio and Pseudoalteromonas were the dominant genera in protocol 4, and they showed advantages in isolating and cultivating Marine-derived Vibrio. Exiguobacterium, Staphylococcus, and Bacillus were the dominant genera in protocol 5. Bacillus cereus and Lactococcus lactis were the most abundant pathogenic bacteria detected with 20 and 15 isolates, respectively, while Lactococcus lactis was uniquely detected at higher abundance. Metagenomic sequencing showed that Klebsiella pneumoniae was significantly dominant with a gene abundance of 51.11%, followed by Alcanivorax sp. at 12.57%. Conclusion: The surface water of the northeast coast of Hainan Island in China exhibits a rich diversity of bacteria, with Klebsiella pneumoniae being highly abundant in the studied area. Different cultivation methods demonstrate distinct selective advantages in culturing bacterial genera and pathogens. Therefore, it is necessary to optimize cultivation conditions for specific marine bacteria.

Regulatory enhancer profiling of mesenchymal-type gastric cancer reveals subtype-specific epigenomic landscapes and targetable vulnerabilities

OBJECTIVE

Gastric cancer (GC) comprises multiple molecular subtypes. Recent studies have highlighted mesenchymal-subtype GC (Mes-GC) as a clinically aggressive subtype with few treatment options. Combining multiple studies, we derived and applied a consensus Mes-GC classifier to define the Mes-GC enhancer landscape revealing disease vulnerabilities.

DESIGN

Transcriptomic profiles of ~1000 primary GCs and cell lines were analysed to derive a consensus Mes-GC classifier. Clinical and genomic associations were performed across >1200 patients with GC. Genome-wide epigenomic profiles (H3K27ac, H3K4me1 and assay for transposase-accessible chromatin with sequencing (ATAC-seq)) of 49 primary GCs and GC cell lines were generated to identify Mes-GC-specific enhancer landscapes. Upstream regulators and downstream targets of Mes-GC enhancers were interrogated using chromatin immunoprecipitation followed by sequencing (ChIP-seq), RNA sequencing, CRISPR/Cas9 editing, functional assays and pharmacological inhibition.

RESULTS

We identified and validated a 993-gene cancer-cell intrinsic Mes-GC classifier applicable to retrospective cohorts or prospective single samples. Multicohort analysis of Mes-GCs confirmed associations with poor patient survival, therapy resistance and few targetable genomic alterations. Analysis of enhancer profiles revealed a distinctive Mes-GC epigenomic landscape, with TEAD1 as a master regulator of Mes-GC enhancers and Mes-GCs exhibiting preferential sensitivity to TEAD1 pharmacological inhibition. Analysis of Mes-GC super-enhancers also highlighted NUAK1 kinase as a downstream target, with synergistic effects observed between NUAK1 inhibition and cisplatin treatment.

CONCLUSION

Our results establish a consensus Mes-GC classifier applicable to multiple transcriptomic scenarios. Mes-GCs exhibit a distinct epigenomic landscape, and TEAD1 inhibition and combinatorial NUAK1 inhibition/cisplatin may represent potential targetable options.

Chromatin Rewiring by Mismatch Repair Protein MSH2 Alters Cell Adhesion Pathways and Sensitivity to BET Inhibition in Gastric Cancer

Mutations in the DNA mismatch repair gene MSH2 are causative of microsatellite instability (MSI) in multiple cancers. Here, we discovered that besides its well-established role in DNA repair, MSH2 exerts a novel epigenomic function in gastric cancer. Unbiased CRISPR-based mass spectrometry combined with genome-wide CRISPR functional screening revealed that in early-stage gastric cancer MSH2 genomic binding is not randomly distributed but rather is associated specifically with tumor-associated super-enhancers controlling the expression of cell adhesion genes. At these loci, MSH2 genomic binding was required for chromatin rewiring, de novo enhancer-promoter interactions, maintenance of histone acetylation levels, and regulation of cell adhesion pathway expression. The chromatin function of MSH2 was independent of its DNA repair catalytic activity but required MSH6, another DNA repair gene, and recruitment to gene loci by the SWI/SNF chromatin remodeler SMARCA4/BRG1. Loss of MSH2 in advanced gastric cancers was accompanied by deficient cell adhesion pathway expression, epithelial-mesenchymal transition, and enhanced tumorigenesis in vitro and in vivo. However, MSH2-deficient gastric cancers also displayed addiction to BAZ1B, a bromodomain-containing family member, and consequent synthetic lethality to bromodomain and extraterminal motif (BET) inhibition. Our results reveal a role for MSH2 in gastric cancer epigenomic regulation and identify BET inhibition as a potential therapy in MSH2-deficient gastric malignancies.

SIGNIFICANCE

DNA repair protein MSH2 binds and regulates cell adhesion genes by enabling enhancer-promoter interactions, and loss of MSH2 causes deficient cell adhesion and bromodomain and extraterminal motif inhibitor synthetic lethality in gastric cancer.

Epigenetic promoter alterations in GI tumour immune-editing and resistance to immune checkpoint inhibition

OBJECTIVES

Epigenomic alterations in cancer interact with the immune microenvironment to dictate tumour evolution and therapeutic response. We aimed to study the regulation of the tumour immune microenvironment through epigenetic alternate promoter use in gastric cancer and to expand our findings to other gastrointestinal tumours.

DESIGN

Alternate promoter burden (APB) was quantified using a novel bioinformatic algorithm (proActiv) to infer promoter activity from short-read RNA sequencing and samples categorised into APB_high, APB_int and APB_low. Single-cell RNA sequencing was performed to analyse the intratumour immune microenvironment. A humanised mouse cancer in vivo model was used to explore dynamic temporal interactions between tumour kinetics, alternate promoter usage and the human immune system. Multiple cohorts of gastrointestinal tumours treated with immunotherapy were assessed for correlation between APB and treatment outcomes.

RESULTS

APB_high gastric cancer tumours expressed decreased levels of T-cell cytolytic activity and exhibited signatures of immune depletion. Single-cell RNAsequencing analysis confirmed distinct immunological populations and lower T-cell proportions in APB_high tumours. Functional in vivo studies using 'humanised mice' harbouring an active human immune system revealed distinct temporal relationships between APB and tumour growth, with APB_high tumours having almost no human T-cell infiltration. Analysis of immunotherapy-treated patients with GI cancer confirmed resistance of APB_high tumours to immune checkpoint inhibition. APB_high gastric cancer exhibited significantly poorer progression-free survival compared with APB_low (median 55 days vs 121 days, HR 0.40, 95% CI 0.18 to 0.93, p=0.032).

CONCLUSION

These findings demonstrate an association between alternate promoter use and the tumour microenvironment, leading to immune evasion and immunotherapy resistance.

Integrative epigenomic and high-throughput functional enhancer profiling reveals determinants of enhancer heterogeneity in gastric cancer

BACKGROUND

Enhancers are distal cis-regulatory elements required for cell-specific gene expression and cell fate determination. In cancer, enhancer variation has been proposed as a major cause of inter-patient heterogeneity-however, most predicted enhancer regions remain to be functionally tested.

METHODS

We analyzed 132 epigenomic histone modification profiles of 18 primary gastric cancer (GC) samples, 18 normal gastric tissues, and 28 GC cell lines using Nano-ChIP-seq technology. We applied Capture-based Self-Transcribing Active Regulatory Region sequencing (CapSTARR-seq) to assess functional enhancer activity. An Activity-by-contact (ABC) model was employed to explore the effects of histone acetylation and CapSTARR-seq levels on enhancer-promoter interactions.

RESULTS

We report a comprehensive catalog of 75,730 recurrent predicted enhancers, the majority of which are GC-associated in vivo (> 50,000) and associated with lower somatic mutation rates inferred by whole-genome sequencing. Applying CapSTARR-seq to the enhancer catalog, we observed significant correlations between CapSTARR-seq functional activity and H3K27ac/H3K4me1 levels. Super-enhancer regions exhibited increased CapSTARR-seq signals compared to regular enhancers, even when decoupled from native chromatin contexture. We show that combining histone modification and CapSTARR-seq functional enhancer data improves the prediction of enhancer-promoter interactions and pinpointing of germline single nucleotide polymorphisms (SNPs), somatic copy number alterations (SCNAs), and trans-acting TFs involved in GC expression. We identified cancer-relevant genes (ING1, ARL4C) whose expression between patients is influenced by enhancer differences in genomic copy number and germline SNPs, and HNF4α as a master trans-acting factor associated with GC enhancer heterogeneity.

CONCLUSIONS

Our results indicate that combining histone modification and functional assay data may provide a more accurate metric to assess enhancer activity than either platform individually, providing insights into the relative contribution of genetic (cis) and regulatory (trans) mechanisms to GC enhancer functional heterogeneity.

Exchange bias and Verwey transition in Fe5C2/Fe3O4 core/shell nanoparticles

This report presents new findings of exchange bias and related structural and magnetic properties in iron carbide/magnetite (Fe₅C₂/Fe₃O₄) core/shell nanoparticles. The exchange bias emerges from an energetic landscape, namely a first-order phase transition-the Verwey transition at 125 K, during which the Fe₃O₄ shell changes from the cubic to monoclinic structure. The phase transition leads to the exchange bias because it results in abrupt changes in magnetocrystalline anisotropy and exchange coupling. Another unique phenomenon identified in this composite system is enhanced magnetic coercivity due to the uniaxial anisotropy of the monoclinic phase. An analysis of the correlations between the observed phenomena is given based on the temperature dependence of the coercivity, the exchange bias field values, and the Verwey transition temperature.

Highly recurrent CBS epimutations in gastric cancer CpG island methylator phenotypes and inflammation

Background

CIMP (CpG island methylator phenotype) is an epigenetic molecular subtype, observed in multiple malignancies and associated with the epigenetic silencing of tumor suppressors. Currently, for most cancers including gastric cancer (GC), mechanisms underlying CIMP remain poorly understood. We sought to discover molecular contributors to CIMP in GC, by performing global DNA methylation, gene expression, and proteomics profiling across 14 gastric cell lines, followed by similar integrative analysis in 50 GC cell lines and 467 primary GCs.

Results

We identify the cystathionine beta-synthase enzyme (CBS) as a highly recurrent target of epigenetic silencing in CIMP GC. Likewise, we show that CBS epimutations are significantly associated with CIMP in various other cancers, occurring even in premalignant gastroesophageal conditions and longitudinally linked to clinical persistence. Of note, CRISPR deletion of CBS in normal gastric epithelial cells induces widespread DNA methylation changes that overlap with primary GC CIMP patterns. Reflecting its metabolic role as a gatekeeper interlinking the methionine and homocysteine cycles, CBS loss in vitro also causes reductions in the anti-inflammatory gasotransmitter hydrogen sulfide (H₂S), with concomitant increase in NF-κB activity. In a murine genetic model of CBS deficiency, preliminary data indicate upregulated immune-mediated transcriptional signatures in the stomach.

Conclusions

Our results implicate CBS as a bi-faceted modifier of aberrant DNA methylation and inflammation in GC and highlights H₂S donors as a potential new therapy for CBS-silenced lesions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13059-021-02375-2.

[Serological study of Lyme disease antibody in 2 311 patients with arthritis symptoms in Hainan Province]

Objective: To understand the infectious status of Lyme disease among patients with arthritis symptoms in Hainan Province, and to provide a theoretical basis for prevention and control of Lyme disease. Methods: From 2013 to 2018, sampling surveys had been conducted in medical institutions in 8 cities in Hainan Province(Haikou, Sanya, Danzhou, Dongfang, Wenchang, Qionghai, Qiongzhong, Wuzhishan), 2 311 patients serum samples were collected with arthritis symptoms, and descriptive research were conducted base on the collected clinical data. The Indirect Fluorescent-Antibody Test (IFA) method was used for preliminary screening of Lyme disease antibody, the Western Blot (WB) method was used for IFA positive samples confirmation. Statistical analysis using χ² test. Results: 2 311 serum samples were tested by IFA, and 166 were positive with the positive rate of 7.18%. Further confirmed by WB method, 62 samples were positive, the positive rate of Lyme disease antibody was 2.68%(62/2 311). The positive rate of Lyme disease antibody among patients with arthritis in different regions of Hainan was statistically significant (χ²=40.636,P<0.001), and the positive rate in Qiongzhong city was the highest (8.81%, 14/159). Danzhou's positive rate was the second highest, 5.62%(5/89). Dongfang city had the lowest positive rate (0.51%, 2/394). The positive rates of Lyme disease serum antibody in men and women were 2.79% (33/1 182) and 2.57% (29/1 129), respectively; the positive rates of antibodies between each age groups were in the range of 1.74% to 3.64%. The antibody positive rate of Lyme disease showed no significant difference between gender and age (χ²=0.110,P=0.740 ;χ²=1.938,P=0.747). Conclusion: Patients with arthritis symptoms caused by Borrelia burgdorferi infection were found in 8 cities in Hainan province, but the Lyme disease antibody positive rate was different among cities, with Qiongzhong County being the highest.

Magnetic-field-induced self-assembly of FeCo/CoFe2O4 core/shell nanoparticles with tunable collective magnetic properties

Self-assembly of nanoparticles into ordered patterns is a novel approach to build up new consolidated materials with desired collective physical properties. Herein, nanoparticle assemblies of composition-modulated bimagnetic nanoparticles have been produced via slow evaporation of their colloidal suspension in the absence or presence of magnetic fields. The assemblies obtained in the presence of the magnetic fields exhibit oriented nanoparticle chains in face-centered cubic superlattice structures, compared with the hexagonal closed-packed superlattice obtained without the magnetic field. The oriented structure has an alignment of the easy magnetization axis along the chains. This alignment leads to enhanced intra-superlattice interactions. As a result, the field-induced assembly displays collective magnetic properties with significantly enhanced magnetic anisotropy, remanent magnetization and coercivity. It is also found that the bimagnetic FeCo/CoFe2O4 core/shell nanostructure enhances the intra-particle interaction and thus is beneficial for the growth of oriented assembly of nanoparticles. Furthermore, the collective magnetic behavior is evidenced by the observation of a superferromagnetic-like magnetization relaxation in the ac-susceptibility curves.

Genomic and epigenomic EBF1 alterations modulate TERT expression in gastric cancer

Transcriptional reactivation of telomerase catalytic subunit (TERT) is a frequent hallmark of cancer, occurring in 90% of human malignancies. However, specific mechanisms driving TERT reactivation remain obscure for many tumor types and in particular gastric cancer (GC), a leading cause of global cancer mortality. Here, through comprehensive genomic and epigenomic analysis of primary GCs and GC cell lines, we identified the transcription factor early B cell factor 1 (EBF1) as a TERT transcriptional repressor and inactivation of EBF1 function as a major cause of TERT upregulation. Abolishment of EBF1 function occurs through 3 distinct (epi)genomic mechanisms. First, EBF1 is epigenetically silenced via DNA methyltransferase, polycomb-repressive complex 2 (PRC2), and histone deacetylase activity in GCs. Second, recurrent, somatic, and heterozygous EBF1 DNA-binding domain mutations result in the production of dominant-negative EBF1 isoforms. Third, more rarely, genomic deletions and rearrangements proximal to the TERT promoter remobilize or abolish EBF1-binding sites, derepressing TERT and leading to high TERT expression. EBF1 is also functionally required for various malignant phenotypes in vitro and in vivo, highlighting its importance for GC development. These results indicate that multimodal genomic and epigenomic alterations underpin TERT reactivation in GC, converging on transcriptional repressors such as EBF1.

Cross-species chromatin interactions drive transcriptional rewiring in Epstein-Barr virus-positive gastric adenocarcinoma

Epstein-Barr virus (EBV) is associated with several human malignancies including 8-10% of gastric cancers (GCs). Genome-wide analysis of 3D chromatin topologies across GC lines, primary tissue and normal gastric samples revealed chromatin domains specific to EBV-positive GC, exhibiting heterochromatin-to-euchromatin transitions and long-range human-viral interactions with non-integrated EBV episomes. EBV infection in vitro suffices to remodel chromatin topology and function at EBV-interacting host genomic loci, converting H3K9me3⁺ heterochromatin to H3K4me1⁺/H3K27ac⁺ bivalency and unleashing latent enhancers to engage and activate nearby GC-related genes (for example TGFBR2 and MZT1). Higher-order epigenotypes of EBV-positive GC thus signify a novel oncogenic paradigm whereby non-integrative viral genomes can directly alter host epigenetic landscapes ('enhancer infestation'), facilitating proto-oncogene activation and tumorigenesis.

Integrated paired-end enhancer profiling and whole-genome sequencing reveals recurrent CCNE1 and IGF2 enhancer hijacking in primary gastric adenocarcinoma

OBJECTIVE

Genomic structural variations (SVs) causing rewiring of cis-regulatory elements remain largely unexplored in gastric cancer (GC). To identify SVs affecting enhancer elements in GC (enhancer-based SVs), we integrated epigenomic enhancer profiles revealed by paired-end H3K27ac ChIP-sequencing from primary GCs with tumour whole-genome sequencing (WGS) data (PeNChIP-seq/WGS).

DESIGN

We applied PeNChIP-seq to 11 primary GCs and matched normal tissues combined with WGS profiles of >200 GCs. Epigenome profiles were analysed alongside matched RNA-seq data to identify tumour-associated enhancer-based SVs with altered cancer transcription. Functional validation of candidate enhancer-based SVs was performed using CRISPR/Cas9 genome editing, chromosome conformation capture assays (4C-seq, Capture-C) and Hi-C analysis of primary GCs.

RESULTS

PeNChIP-seq/WGS revealed ~150 enhancer-based SVs in GC. The majority (63%) of SVs linked to target gene deregulation were associated with increased tumour expression. Enhancer-based SVs targeting CCNE1, a key driver of therapy resistance, occurred in 8% of patients frequently juxtaposing diverse distal enhancers to CCNE1 proximal regions. CCNE1-rearranged GCs were associated with high CCNE1 expression, disrupted CCNE1 topologically associating domain (TAD) boundaries, and novel TAD interactions in CCNE1-rearranged primary tumours. We also observed IGF2 enhancer-based SVs, previously noted in colorectal cancer, highlighting a common non-coding genetic driver alteration in gastric and colorectal malignancies.

CONCLUSION

Integrated paired-end NanoChIP-seq and WGS of gastric tumours reveals tumour-associated regulatory SV in regions associated with both simple and complex genomic rearrangements. Genomic rearrangements may thus exploit enhancer-hijacking as a common mechanism to drive oncogene expression in GC.

HNF4α pathway mapping identifies wild-type IDH1 as a targetable metabolic node in gastric cancer

OBJECTIVE

Gastric cancer (GC) is a leading cause of cancer mortality. Previous studies have shown that hepatocyte nuclear factor-4α (HNF4α) is specifically overexpressed in GC and functionally required for GC development. In this study, we investigated, on a genome-wide scale, target genes of HNF4α and oncogenic pathways driven by HNF4α and HNF4α target genes.

DESIGN

We performed HNF4α chromatin immunoprecipitation followed by sequencing across multiple GC cell lines, integrating HNF4α occupancy data with (epi)genomic and transcriptome data of primary GCs to define HNF4α target genes of in vitro and in vivo relevance. To investigate mechanistic roles of HNF4α and HNF4α targets, we performed cancer metabolic measurements, drug treatments and functional assays including murine xenograft experiments.

RESULTS

Gene expression analysis across 19 tumour types revealed HNF4α to be specifically upregulated in GCs. Unbiased pathway analysis revealed organic acid metabolism as the top HNF4α-regulated pathway, orthogonally supported by metabolomic analysis. Isocitrate dehydrogenase 1 (IDH1) emerged as a convergent HNF4α direct target gene regulating GC metabolism. We show that wild-type IDH1 is essential for GC cell survival, and that certain GC cells can be targeted by IDH1 inhibitors.

CONCLUSIONS

Our results highlight a role for HNF4α in sustaining GC oncogenic metabolism, through the regulation of IDH1. Drugs targeting wild-type IDH1 may thus have clinical utility in GCs exhibiting HNF4α overexpression, expanding the role of IDH1 in cancer beyond IDH1/2 mutated malignancies.

HoxC5 and miR-615-3p target newly evolved genomic regions to repress hTERT and inhibit tumorigenesis

The repression of telomerase activity during cellular differentiation promotes replicative aging and functions as a physiological barrier for tumorigenesis in long-lived mammals, including humans. However, the underlying mechanisms remain largely unclear. Here we describe how miR-615-3p represses hTERT expression. mir-615-3p is located in an intron of the HOXC5 gene, a member of the highly conserved homeobox family of transcription factors controlling embryogenesis and development. Unexpectedly, we found that HoxC5 also represses hTERT expression by disrupting the long-range interaction between hTERT promoter and its distal enhancer. The 3'UTR of hTERT and its upstream enhancer region are well conserved in long-lived primates. Both mir-615-3p and HOXC5 are activated upon differentiation, which constitute a feed-forward loop that coordinates transcriptional and post-transcriptional repression of hTERT during cellular differentiation. Deregulation of HOXC5 and mir-615-3p expression may contribute to the activation of hTERT in human cancers.

Genomic and Epigenomic Profiling of High-Risk Intestinal Metaplasia Reveals Molecular Determinants of Progression to Gastric Cancer

Intestinal metaplasia (IM) is a pre-malignant condition of the gastric mucosa associated with increased gastric cancer (GC) risk. We performed (epi)genomic profiling of 138 IMs from 148 cancer-free patients, recruited through a 10-year prospective study. Compared with GCs, IMs exhibit low mutational burdens, recurrent mutations in certain tumor suppressors (FBXW7) but not others (TP53, ARID1A), chromosome 8q amplification, and shortened telomeres. Sequencing identified more IM patients with active Helicobacter pylori infection compared with histopathology (11%-27%). Several IMs exhibited hypermethylation at DNA methylation valleys; however, IMs generally lack intragenic hypomethylation signatures of advanced malignancy. IM patients with shortened telomeres and chromosomal alterations were associated with subsequent dysplasia or GC; conversely patients exhibiting normal-like epigenomic patterns were associated with regression.

Epigenomic Consequences of Coding and Noncoding Driver Mutations

Chromatin alterations are integral to the pathogenic process of cancer, as demonstrated by recent discoveries of frequent mutations in chromatin-modifier genes and aberrant DNA methylation states in different cancer types. Progress is being made on elucidating how chromatin alterations, and how proteins catalyzing these alterations, mechanistically contribute to tissue-specific tumorigenesis. In parallel, technologies enabling the genome-wide profiling of histone modifications have revealed the existence of noncoding driver genetic alterations in cancer. In this review, we survey the current knowledge of coding and noncoding cancer drivers, and discuss their impact on the chromatin landscape. Translational implications of these findings for novel cancer therapies are also presented.

[Cross-sectional study of family drug stockpile and children medication in China]

OBJECTIVE

To investigate the current situation of family medicine stockpile and children medication in China, analyze the existing problems and provide the rationalized suggestions.

METHODS

The questionnaire was designed and convenient sampling survey was performed in 20 children hospitals in China. Descriptive analysis was conducted on the survey results.

RESULTS

A total of 13 940 completed questionnaires were returned, 98.33% of the families had medicine stockpile, the top three types of the medicine for children were cold medicine(73.95%), oral paregoric/febrifuge(48.01%)and external used drugs for skin disease(wound)(41.10%). The medicine was bought according to physician's prescription and guide(71.18%). Drug poisoning occurred in children of 238 families(1.71%), overdose use was the first cause(44.96%). 22.33% of the parents didn't read the specification carefully before medicine use. The non-appropriate medication for children were mainly the use of adult medicine(32.70%), untimely medication(30.90%), non-rational or unneeded use of febrifuge(26.35%).

CONCLUSIONS

In China, the families mainly store common medicine for their children. The parents bought medicine mainly according to physician' s prescription and paid attention to the safety and efficiency of the medicine, but non-appropriate use of medicine was still common. It is necessary to improve the rational use of medicine for children through expert counsel and guidance.

Repetitive transcranial magnetic stimulation enhances spatial learning and synaptic plasticity via the VEGF and BDNF-NMDAR pathways in a rat model of vascular dementia

This study aimed to evaluate the effects of repetitive transcranial magnetic stimulation (rTMS) on learning and memory in a rat model of vascular dementia (VaD) and to analyze the associated mechanisms. Bilateral carotid artery occlusion (2-VO) was used to establish a rat model of VaD. High-frequency (5Hz) rTMS was performed on rats for four weeks. Spatial learning and memory abilities were evaluated using the Morris water maze (MWM), and synaptic plasticity in the hippocampus was assessed via long-term potentiation (LTP). Hippocampal expression of vascular endothelial growth factor (VEGF), brain-derived neurotrophic factor (BDNF) and three subunits of the N-methyl-D-aspartic acid receptor (NMDAR), NR1, NR2A and NR2B, was analyzed by Western blotting. Compared with the VaD group, escape latency was decreased (P<0.05) and the time spent in the target quadrant and the percentage of swimming distance within that quadrant were increased (P<0.05) in the rTMS group. LTP at hippocampal CA3-CA1 synapses was enhanced by rTMS (P<0.05). VEGF expression was up-regulated following 2-VO and was further increased by rTMS (P<0.05). BDNF, NR1 and NR2B expression was decreased in the VaD group and increased by rTMS (P<0.05). There were no significant differences in NR2A expression among the three groups. These results suggest that rTMS improved learning and memory in the VaD model rats via the up-regulation of VEGF, BDNF and NMDARs. In addition, NR2B may be more important than NR2A for LTP induction in the hippocampus during rTMS treatment of VaD.

Mating system patterns of natural populations of Pinus koraiensis along its post-glacial colonization route in northeastern China

To understand the genetic mechanisms underlying the endangerment of Pinus koraiensis, we studied the mating system of 49 families of this species in 3 natural populations along its post-glacial colonization route across ~1500 km in northeastern China using the chloroplast simple sequence repeat technique. We analyzed 11 polymorphic loci with clear and repeating bands, and we calculated the multi-locus outcrossing rate (tm), single-locus outcrossing rate, inbreeding index, and fixation index (F). Intra-population variation was not observed, but a large inter-population variation was observed in the outcrossing rate, and the tm increased from 0.767 (the south population) to 0.962 (the north population) along the post-glacial colonization route. The tm values within a population did not change with time over 2 consecutive years. The F values for the 3 populations were <0, which indicates an excess of heterozygotes. The mean effective number of alleles, Shannon diversity index, and Nei's genetic diversity index did not show a south-north pattern. The north population had the highest outcrossing rate but the lowest genetic diversity. The average genetic differentiation of P. koraiensis populations was 0.1251, which was within the average range of woody plants with outcrossing and wind pollination. This study suggests that the current endangerment of P. koraiensis is not related to its genetic structure; perhaps it is mainly caused by man-made and natural disturbances such as deforestation and fire. Therefore, reducing disturbances and enhancing habitats, rather than the genetic aspects, play more important roles in the long-term protection of P. koraiensis.

Mussel-inspired nanofibrous sheet for suture-less stomach incision surgery

We report a dopamine-based crosslinker-conjugated gelatin/polycaprolactone nanofibrous sheet. The nanosheet was then employed to treat stomach incisions without sutures during surgery.