Occurrence and spatiotemporal distribution of arsenic biotransformation genes in urban dust.

Microbially-mediated arsenic biotransformation plays a pivotal role in the biogeochemical cycling of arsenic; however, the presence of arsenic biotransformation genes (ABGs) in urban dust remains unclear. To investigate the occurrence and spatiotemporal distributions of ABGs, a total of one hundred and eighteen urban dust samples were collected from different districts of Xiamen city, China in summer and winter. Although inorganic arsenic species, including arsenate [As(V)] and arsenite [As(III)], were found to be predominant, the methylated arsenicals, particularly trimethylarsine oxide [TMAs(V)O] and dimethylarsenate [DMAs(V)], were detected in urban dust. Abundant ABGs were identified in urban dust via AsChip analysis (a high-throughput qPCR chip for ABGs), of which As(III) S-adenosylmethionine methyltransferase genes (arsM), As(V) reductase genes (arsC), As(III) oxidase genes (aioA), As(III) transporter genes (arsB), and arsenic-sensing regulator genes (arsR) were the most prevalent, collectively constituting more than 90 % of ABGs in urban dust. Microbes involved in arsenic methylation were assigned to bacteria (e.g., Actinomycetes and Alphaproteobacteria), archaea (e.g., Halobacteria), and eukaryotes (e.g., Chlamydomonadaceae) in urban dust via the arsM amplicon sequencing. Temperature, a season-dependent environmental factor, profoundly affected the abundance of ABGs and the composition of microbes involved in arsenic methylation. This study provides new insights into the presence of ARGs within the urban dust.

Comprehensive analysis of metal(loid)s and associated metal(loid) resistance genes in atmospheric particulate matter.

Despite global concerns about metal(loid)s in atmospheric particulate matter (PM), the presence of metal(loid) resistance genes (MRGs) in PM remains unknown. Therefore, we conducted a comprehensive investigation of the metal(loid)s and associated MRGs in PMs in two seasons (summer and winter) in Xiamen, China. According to the geoaccumulation index (Igeo), most metal(loid)s, except for V and Mn, exhibited enrichment in PM, suggesting potential anthropogenic sources. By employing Positive Matrix Factorization (PMF) model, utilizing a dataset encompassing both total and bioaccessible metal(loid)s, along with backward trajectory simulations, traffic emissions were determined to be the primary potential contributor of metal(loid)s in summer, whereas coal combustion was observed to have a dominant contribution in winter. The major contributor to the carcinogenic risk of metal(loid)s in both summer and winter was predominantly attributed to coal combustion, which serves as the main source of bioaccessible Cr. Bacterial communities within PMs showed lower diversity and network complexity in summer than in winter, with Pseudomonadales being the dominant order. Abundant MRGs, including the As(III) S-adenosylmethionine methyltransferase gene (arsM), Cu(I)-translocating P-type ATPase gene (copA), Zn(II)/Cd(II)/Pb(II)-translocating P-type ATPase gene (zntA), and Zn(II)-translocating P-type ATPase gene (ziaA), were detected within the PMs. Seasonal variations were observed for the metal(loid) concentration, bacterial community structure, and MRG abundance. The bacterial community composition and MRG abundance within PMs were primarily influenced by temperature, rather than metal(loid)s. This research offers novel perspectives on the occurrence of metal(loid)s and MRGs in PMs, thereby contributing to the control of air pollution.

Valve implantation for successful sealing of a balloon predilatation-induced annular rupture during transcatheter aortic valve replacement.

Annular rupture is a rare and dreaded complication of transcatheter aortic valve replacement (TAVR) and even rarer when caused by predilatation balloon aortic valvuloplasty. This complication often presents as sudden cardiac tamponade with hypotension and requires urgent intervention. The traditional rescue strategy for patients with annular rupture is emergency surgical repair. However, the mortality rate is still high, considering that most patients who undergo TAVR are not candidates for conventional cardiac surgery. Therefore, there is a need for additional emergency treatment strategies to decrease mortality. This report describes a case of predilatation-induced annular rupture during TAVR that was successfully sealed at the rupture site by valve implantation. This case suggests that continuing with valve deployment may be a successful treatment for predilatation-induced annular rupture during TAVR.

Bioaccessibility of microplastic-associated heavy metals using an in vitro digestion model and its implications for human health risk assessment.

Microplastics can act as carriers of heavy metals and may enter humans through ingestion and threaten human health. However, the bioaccessibility of heavy metals associated with microplastics and its implications for human health risk assessments are poorly understood. Therefore, in this study, four typical heavy metals (As(V), Cr(VI), Cd(II), and Pb(II)) and one typical microplastic (polyvinyl chloride, PVC) were chosen to estimate the human health risk of microplastic-associated heavy metals by incorporating bioaccessibility. Significant adsorption of heavy metals was observed with the following order for adsorption capacity: Pb(II) > Cr(VI) > Cd(II) > As(V); the efficiencies for desorption of these four heavy metals from PVC microplastics were all below 10%. The Fourier transform infrared spectroscopy results indicated that the functional groups on the surface of the virgin PVC microplastics did not play an important role in the capture process. Heavy metals in both gastric and small intestinal phases were prone to release from PVC microplastics when bioaccessibility was evaluated with the in vitro SBRC (Soluble Bioavailability Research Consortium) digestion model. In addition, Pb(II) bioaccessibility in the gastric phase was significantly higher than those in the other phases, while As(V), Cr(VI), and Cd(II) bioaccessibilities showed the opposite trend. After incorporating bioaccessibility adjustments, the noncarcinogenic hazards and carcinogenic risks determined were lower than those based on total metal contents. The individual hazard quotients (HQ) and carcinogenic risks (CR) for ingestion of these four heavy metals from PVC microplastics were all lower than the threshold values for adults and children. In summary, this study will provide a new view of the human health risks of heavy metals associated with microplastics.

[Occurrence Characteristics of Microplastics in Mangrove Sediments in the Jiulong River Estuary and the Association with Heavy Metals].

The abundance and morphological characteristics of microplastics in the surface sediments of mangrove wetlands in the Jiulong River estuary were analyzed. The main sources of microplastics were also explored in detail. The results showed that the abundance of microplastics ranged from 640 to 1140 n·kg-1 (dry sediment), with an average of 935 n·kg-1, exhibiting a medium level compared with other domestic and abroad mangrove areas. The microscopic observation found that the microplastics were granular (39%), fragmented (31%), and fibrous (30%); the color was mainly transparent (55%); and the particle size was less than 1 mm (92%). As observed via Raman spectroscopy, the main polymer types of the microplastics were identified to be polyethylene, polyethylene terephthalate, and polypropylene, accounting for 57%, 34%, and 9%, respectively. The main sources of microplastics were the plastic waste from aquaculture nearby, urban and rural domestic or industrial wastewater in the basin, and the plastic waste transported here by the tide. Additionally, SEM-EDS results showed that the surface of the microplastics had the characteristics of depression, porosity, and tearing, and some heavy metal elements such as Pb, Cd, Hg, Cr, Fe, Mn, Zn, and Cu were attached to the microplastics. Microplastics may be transferred to the sediments as carriers of heavy metals, posing a potential threat to wetland ecological security.

[Effects of low-dose dexmedetomidine combined with hydromorphone in postoperative analgesia and on the serum IL-6 and CRP levels of prostate cancer patients].

OBJECTIVE: To explore the effects of low-dose dexmedetomidine (DM) combined with hydromorphone (HM) in postoperative analgesia and on levels of serum interleukin-6 (IL-6) and C-reactive protein (CRP) in PCa patients. METHODS: Using the random number table, we divided 102 PCa patients undergoing radical prostatectomy from January 2019 to November 2020 into a trial group (n = 51) and a control group (n = 51), the former given HM and the latter low-dose DM + HM for postoperative analgesia. We recorded the postoperative resuscitation time, extubation time and pain, perioperative cognitive function, IL-6 and CRP levels, and drug-related adverse reactions of the patients, and compared them between the two groups. RESULTS: There was no statistically significant difference in postoperative resuscitation time and extubation time between the two groups of patients (P > 0.05). The frequency of patient-controlled epidural analgesia (PCEA) compressions was lower in the trial than in the control group within 24 hours after surgery (P < 0.05). The Visual Analogue Scale (VAS) scores were higher in both of the groups at 24 hours than at 4, 12, and 48 hours after surgery (P < 0.05), at 12 hours than at 4 and 48 hours (P < 0.05) and at 4 hours than at 48 hours (P < 0.05), but lower in the trial than in the control group at 4, 12 and 24 hours postoperatively (P < 0.05). No statistically significant difference was observed in the scores of the Mini Mental State Evaluation Scale between the two groups of patients (P > 0.05). The levels of IL-6 and CRP were higher in both of the groups at 24 hours after than before and at 4, 12 and 48 hours after surgery (P < 0.05), at 48 hours after than before and at 4 and 12 hours after surgery (P < 0.05), at 12 hours after than before and at 4 hours after surgery (P <0.05), and at 4 hours after than before surgery (P < 0.05), but lower in the trial than in the control group at 4, 12, 24 and 48 hours postoperatively (P < 0.05). There was no statistically significant difference in the total incidence rate of adverse reactions between the two groups (P > 0.05). CONCLUSIONS: Low-dose dexmedetomidine combined with hydromorphone is a safe and effective option for postoperative analgesia in PCa patients, and it can inhibit the expression of inflammatory factors.

Incorporating bioaccessibility and source apportionment into human health risk assessment of heavy metals in urban dust of Xiamen, China.

Heavy metals in urban dust could pose noticeable human health risks, but there are few studies focusing on comprehensive human health risk assessment with the incorporation of both bioaccessibility and source apportionment in urban dust. Thus, fifty-eight urban dust samples were collected from kindergartens in Xiamen to analyze the bioaccessibility-based, source-specific health risk of heavy metals (V, Co, Ni, As, Mo, Cr, Mn, Cu, Zn, and Pb). Most heavy metals, except for V and Mn, were significantly enriched in urban dust based on their values of geoaccumulation index (Igeo) and may be influenced by human activities. The oral bioaccessibility values of heavy metals, which were estimated by the Solubility/Bioaccessibility Research Consortium (SBRC) in vitro model, ranged from 1.563% to 76.51%. The source apportionment determined by applying the absolute principal component analysis-multiple linear regression (APCS-MLR) model indicated five main potential sources, coal combustion, traffic and industrial, natural, construction and furniture sources, and unidentified sources, with contributions of 34.09%, 20.72%, 18.72%, 7.597% and 18.87%, respectively, to the accumulation of heavy metals in urban dust. After incorporating bioaccessibility adjustments, lower non-carcinogenic and carcinogenic risks of heavy metals were observed than those based on total metal content, with the mean hazard index (HI) values being less than the threshold value (1) and the mean total carcinogenic risk (TCR) values exceeding the precautionary criterion (10-6) for both adults and children. By combining bioaccessibility-based health risk assessment and source apportionment, traffic and industrial emissions and coal combustion dominated the noncarcinogenic and carcinogenic risks induced by heavy metals in urban dust, respectively. This study is expected to promote the systematic integration of source apportionment and bioaccessibility into health risk estimation for heavy metal contamination in urban dust, thus providing useful implications for better human health protection.

Polymerase chain reaction-based tests for detecting Helicobacter pylori clarithromycin resistance in stool samples: A meta-analysis.

BACKGROUND: Helicobacter pylori (H. pylori) infection is closely associated with the etiology of a variety of gastric diseases. The effective eradication of H. pylori infection has been shown to reduce the incidence of gastric carcinoma. However, the rate of H. pylori eradication has significantly declined due to its increasing resistance to antibiotics, especially to clarithromycin. Therefore, the detection of clarithromycin resistance is necessary prior to the treatment of H. pylori. Although many studies have been conducted on the use of polymerase chain reaction (PCR)-based tests to detect clarithromycin resistance in stool samples, no accurate data on the feasibility of these tests are available. Here, we performed a meta-analysis to assess the feasibility of these noninvasive tests. AIM: To evaluate the reliability of PCR-based tests for detecting H. pylori clarithromycin resistance in stool samples. METHODS: We searched PubMed, Medline, Embase, and other databases for articles that evaluated the value of the PCR analysis of stool samples for detecting the resistance of H. pylori to clarithromycin. We collected cross-sectional studies that met the inclusion criteria. Diagnostic accuracy measures were pooled using a random-effects model. The risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Subgroup analysis was also conducted according to PCR type, purification technique, reference standard, mutation site, sample weight, number of patients, and age group, and the clinical utility of diagnostic tests was evaluated using the Likelihood Ratio Scatter Graph. RESULTS: Out of the 1818 identified studies, only 11 met the eligibility criteria, with a total of 592 patients assessed. A meta-analysis of the random-effect model showed that PCR-based analysis of stool samples had high diagnostic accuracy for detecting clarithromycin resistance in patients infected with H. pylori. The combined sensitivity was 0.91 [95% confidence interval (CI): 0.83-0.95], Q = 30.34, and I 2 = 67.04, and the combined specificity was 0.97 (95%CI: 0.62-1.00), Q = 279.54, and I 2 = 96.42. The likelihood ratio for a positive test was 33.25 (95%CI: 1.69-652.77), and that for a negative test was 0.10 (95%CI: 0.05-0.18), with an area under the curve of 0.94. The diagnostic odds ratio was 347.68 (95%CI: 17.29-6991.26). There was significant statistical heterogeneity, and the sub-analyses showed significant differences in the number of patients, sample weight, purification methods, PCR types, mutation points, and reference standards. The included studies showed no risk of publication bias. CONCLUSION: PCR-based tests on stool samples have high diagnostic accuracy for detecting H. pylori clarithromycin resistance.

Comparative study of allicin-containing quadruple therapy vs. bismuth-containing quadruple therapy for the treatment of Helicobacter pylori infection: a prospective randomized study.

BACKGROUND: Bismuth has antimicrobial activity and can improve the efficacy of triple Helicobacter pylori (H. pylori) therapy. Allicin added to conventional therapy for H. pylori infection also improves H. pylori eradication rates. Thus, this study aims to evaluate and compare the efficacy, safety and tolerability of allicin-containing quadruple therapy and bismuth-containing quadruple therapy and to investigate the factors that affect the eradication rates. METHODS: Two hundred twenty H. pylori-infected patients were included and randomly (1:1) assigned to 14-day quadruple therapy: ilaprazole (5 mg bid), doxycycline (100 mg bid), and furazolidone (100 mg bid) with an allicin soft capsule (40 mg of DATS tid) (IDFA) or colloidal bismuth tartrate (220 mg of elemental bismuth bid) (IDFB). Eradication was confirmed by urea breath tests. Symptom improvement, adverse events, and adherence were assessed by a questionnaire. RESULTS: In the intention-to-treat and per-protocol analysis, the eradication rates for IDFA and IDFB groups were 87.5% (70/80) vs. 86.3% (69/80, P = 0.815) and 91.9% (68/74) vs. 91.8% (67/73, P = 0.980) as first-line therapies; 83.3% (25/30) vs. 83.3% (25/30, P = 1) and 89.3% (25/28) vs. 88.9% (24/27, P = 1) as second-line therapies. Symptom improvement rates were 96.1% and 97.0% for IDFA and IDFB (P = 1). The adverse event rates were 10.9% in IDFA and 14.5% in IDFB groups (P = 0.418). Nausea occurred frequently in IDFB than IDFA (1.8% vs. 8.2%, P = 0.030). Smoking and sharing utensils significantly affected the efficacy. CONCLUSION: Allicin-containing quadruple therapy might be regarded as a promising alternative to bismuth-containing quadruple therapy in H. pylori eradication.

[Bioaccessibility and Health Risks of the Heavy Metals in Soil-Rice System of Southwest Fujian Province].

The bioaccessibility and health risks of heavy metals in soil-rice system of southwestern Fujian province were studied by combining a simple bioavailability extraction method (SBET) with a health risk assessment model. The results showed that some heavy metals in the agricultural soils and rice of southwestern Fujian province were enriched. The contents of Cd, Zn, Pb, and Cu were greater than the screening value of soil pollution risk for agricultural land (GB 15618-2018) by 32.4%, 15.5%, 14.1%, and 12.7% in the study areas, respectively. The accumulation ability of heavy metals was different and followed the approximately decreasing order of Cd > Zn > Cu > Ni > Hg > As > Cr > Pb. The bioaccessibility of heavy metals in soils and rice were quite different. The bioaccessibility of each heavy metal in rice was greater than the bioaccessibility of the heavy metals in soil, which indicated that the heavy metals in rice were more easily absorbed by the human body. The comprehensive non-carcinogenic risk index (HI) of heavy metals to adults and children was 2.71 and 4.06, respectively, indicating that there were non-carcinogenic risks. The comprehensive carcinogenic risk index (TCR) of heavy metals to adults and children was 1.42×10-3 and 5.28×10-4, respectively, indicating that there was a carcinogenic risk present. The non-carcinogenic risks were mainly due to As, while the carcinogenic risks were mainly contributed by Cd. The non-carcinogenic risk of children was higher than that of adults, while the carcinogenic risk of children was lower than that of adults. This result may be related to physiological characteristics, exposure period, and dietary intake. The dietary intake route may be the main pathway for heavy metals in the soil-rice system of southwest Fujian province to cause health risks. Therefore, more attention should be paid to the risks of dietary exposure in the risk management of heavy metals.

How does Helicobacter pylori cause gastric cancer through connexins: An opinion review.

Helicobacter pylori (H. pylori) is a Gram-negative bacterium with a number of virulence factors, such as cytotoxin-associated gene A, vacuolating cytotoxin A, its pathogenicity island, and lipopolysaccharide, which cause gastrointestinal diseases. Connexins function in gap junctional homeostasis, and their downregulation is closely related to gastric carcinogenesis. Investigations into H. pylori infection and the fine-tuning of connexins in cells or tissues have been reported in previous studies. Therefore, in this review, the potential mechanisms of H. pylori-induced gastric cancer through connexins are summarized in detail.

[Sources Analysis and Health Risk Assessment of Polycyclic Aromatic Hydrocarbons in the PM2.5 Fraction of Fugitive Dust in Nanchang City].

In order to understand the sources and health risks of polycyclic aromatic hydrocarbons in the PM2.5 fraction of road dust and soil dust in Nanchang city, PM2.5 samples were collected by a resuspension sampler and the concentrations of sixteen polycyclic aromatic hydrocarbons (PAHs) were detected. The results showed that the ΣPAHs of the road dust ranged from 48.85 to 166.16 µg·kg-1, with a mean of (114.22±39.95) µg·kg-1. The ΣPAHs of the soil dust ranged from 31.05 to 62.92 µg·kg-1 with a mean of (40.79±9.39) µg·kg-1. The PAHs in the PM2.5 fraction of fugitive dust were mainly composed of 4-5 rings. The results of the principal component analysis and multiple linear regression analysis indicated that the PAHs in PM2.5 samples of road dust mainly originated from motor vehicle emissions, coal sources, and oil leakage, with contribution rates of 51.7% and 48.3%, respectively. For children and adult males, the carcinogenic risk values of PAHs in different exposure pathways followed the order dermal contact > ingestion > inhalation, while those for adult females followed the order ingestion > dermal contact > inhalation. For all exposure pathways, the carcinogenic risks of the PAHs to adults were higher than those to children. For all populations, the total carcinogenic risk values of the PAHs were lower than the US EPA recommended carcinogenic risk threshold of 10-6, indicating no carcinogenic risk.

Comparison of clinical outcomes between intravascular optical coherence tomography-guided and angiography-guided stent implantation: A meta-analysis of randomized control trials and systematic review.

OBJECTIVE: This systematic review was designed to evaluate the overall efficacy of optical coherence tomography (OCT)-guided implantation versus angiography-guided for percutaneous coronary intervention. METHODS: The following electronic databases, such as CENTRAL, PubMed, Cochrane, and EMBASE were searched for systematic reviews to investigate OCT-guided and angiography-guided implantation. We measured the following 7 parameters in each patient: stent thrombosis, cardiovascular death, myocardial infarction, major adverse cardiac events (MACE), target lesion revascularization (TLR), target vessel revascularization (TVR), all-cause death. RESULTS: In all, 11 studies (6 RCTs and 5 observational studies) involving 4026 subjects were included, with 1903 receiving intravascular ultrasound-guided drug-eluting stent (DES) implantation and 2123 using angiography-guided DES implantation. With regard to MACE, MT, TLR, TVR, stent thrombosis and all-cause death, the group of OCT-guided implantation had no significant statistical association with remarkably improved clinical outcomes. However, its effect on cardiovascular death has a significant statistical difference in angiography-guided implantation group. CONCLUSION: In the present pool analysis, OCT-guided DES implantation showed a tendency toward improved clinical outcomes compared to angiography-guided implantation. More eligible randomized clinical trials are warranted to verify the findings and to determine the beneficial effect of OCT-guidance for patients.

Remote ischemic conditioning during primary percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction: a systematic review and meta-analysis.

OBJECTIVE: This systematic review was designed to evaluate the efficacy of remote ischemic conditioning (RIC) with primary percutaneous coronary intervention (PCI) versus primary PCI alone for ST-segment elevation myocardial infarction (STEMI). SEARCH STRATEGY: Computerized search for trials from PubMed, EMBASE, CENTRAL and Cochrane Database of Systematic Reviews databases. SELECTION CRITERIA: Trials investigating RIC plus primary PCI (group A) versus primary PCI alone (group B). OUTCOME MEASURES: Myocardial enzyme levels; left ventricular ejection fraction (LVEF); major adverse cardiac and cerebrovascular events (MACCEs); TIMI flow grade III; myocardial salvage index or infarct size per patients. RESULTS: In all, 14 studies involving 3165 subjects were included. There was a significant association of myocardial edema levels, myocardial salvage index and incidence of MACCEs in group A compared with group B (myocardial edema levels: SMD = - 0.36, 95% CI (- 0.59, - 0.13); myocardial salvage index: MD = 0.06, 95% CI (0.02, 0.10); MACCE: OR = 0.70, 95% CI (0.57, 0.85)). With regard to infarct size, TIMI flow grade III and LVEF, group A appeared to be equivalent with group B (infarct size: MD = - 1.67, 95% CI (- 3.46, 0.11); TIMI flow grade III: OR = 1.04, 95% CI (0.71, 1.52); LVEF: MD = 0.74, 95% CI (- 0.80, 2.28)). CONCLUSION: RIC was associated with lower myocardial edema levels, myocardial salvage index and incidence of MACCE, while non-significant beneficial effect on infarct size, TIMI flow grade III or LVEF. These findings suggest that RIC is a promising adjunctive treatment to PCI for the prevention of reperfusion injury in STEMI patients.

[Pollution Assessment and Source Analysis of Metals in PM2.5 in Haicang District, Xiamen City, China].

To determine the spatial-temporal distributions and potential sources of metals in PM2.5 and assess health risks from heavy metals, 348 PM2.5 samples were collected in the Haicang District of Xiamen, China from April 2015 to January 2016. Metals (K, Ca, Na, Mg, Al, Zn, Cu, Fe, Ti, As, V, Mn, Ba, Co) in PM2.5 were detected using an X-ray fluorescence analyzer (XRF). Pollution assessment was performed via enrichment factor calculation and health risk assessment. Potential sources were explored using Pearson's correlation coefficient, principal component analysis, and the HYSPLIT Trajectory Model. Results showed that the total concentration of 14 metal elements contributed to 5.4%-10.6% of PM2.5 during the sampling period. The total concentration of metals was higher in spring and winter than those in summer and autumn. The concentrations were higher in the port and the industrial areas than in residential areas and background locations, in agreement with the seasonal and spatial distribution of PM2.5. The frequency of PM2.5 daily concentrations exceeding the Chinese Ambient Air Quality Standards was higher in the port and residential areas in the summer due to operations at the port and the wind direction. Zn concentration was the highest in the industrial area followed by the background location. Meanwhile, the highest concentration of V was observed in the port area; V concentration in the residential area was high in the summer. These variations in Zn and V indicated that the elements emitted in the polluted areas migrated easily to residential and background areas. K concentrations were the highest in winter and As showed a higher rate of exceeding the standard in winter and spring, indicating that activities, such as biomass burning and coal combustion in the winter severely impacted air quality. The enrichment factors of Cu, Zn, As, Co, Na, and Mn varied considerably, from 67 to 8,449. The total risk level for non-carcinogenic heavy metals (Zn, Cu, Mn) was lower than the average level of risk acceptance (1×10-6 a-1) and Mn contributed 74%-88% of the total risk level of Zn, Cu, and Mn. The combined results of the correlation analysis and the principal component analysis revealed that metals in PM2.5 were mainly came from re-suspension of ground dust, motor vehicle emissions, coal combustion, industrial emissions, and heavy oil combustion, with contributions of 34.5%, 12.5%, 10.6%, and 7.8% respectively. The HYSPLIT Trajectory Model showed that Xiamen was affected by the local air mass in spring, autumn, and winter, but not in summer. Moreover, the rise of PM2.5 in spring and winter was attributed to air masses traveling through the Yangtze River Delta.

Robotic intrafractional US guidance for liver SABR: System design, beam avoidance, and clinical imaging.

PURPOSE: To present a system for robotic 4D ultrasound (US) imaging concurrent with radiotherapy beam delivery and estimate the proportion of liver stereotactic ablative body radiotherapy (SABR) cases in which robotic US image guidance can be deployed without interfering with clinically used VMAT beam configurations. METHODS: The image guidance hardware comprises a 4D US machine, an optical tracking system for measuring US probe pose, and a custom-designed robot for acquiring hands-free US volumes. In software, a simulation environment incorporating the LINAC, couch, planning CT, and robotic US guidance hardware was developed. Placement of the robotic US hardware was guided by a target visibility map rendered on the CT surface by using the planning CT to simulate US propagation. The visibility map was validated in a prostate phantom and evaluated in patients by capturing live US from imaging positions suggested by the visibility map. In 20 liver SABR patients treated with VMAT, the simulation environment was used to virtually place the robotic hardware and US probe. Imaging targets were either planning target volumes (PTVs, range 5.9-679.5 ml) or gross tumor volumes (GTVs, range 0.9-343.4 ml). Presence or absence of mechanical interference with LINAC, couch, and patient body as well as interferences with treated beams was recorded. RESULTS: For PTV targets, robotic US guidance without mechanical interference was possible in 80% of the cases and guidance without beam interference was possible in 60% of the cases. For the smaller GTV targets, these proportions were 95% and 85%, respectively. GTV size (1/20), elongated shape (1/20), and depth (1/20) were the main factors limiting the availability of noninterfering imaging positions. The robotic US imaging system was deployed in two liver SABR patients during CT simulation with successful acquisition of 4D US sequences in different imaging positions. CONCLUSIONS: This study indicates that for VMAT liver SABR, robotic US imaging of a relevant internal target may be possible in 85% of the cases while using treatment plans currently deployed in the clinic. With beam replanning to account for the presence of robotic US guidance, intrafractional US may be an option for 95% of the liver SABR cases.

Identification of genes associated with methotrexate resistance in methotrexate-resistant osteosarcoma cell lines.

BACKGROUND: This study aimed to better understand the mechanisms underlying methotrexate (MTX)-resistance in osteosarcoma. METHODS: The raw transcription microarray data GSE16089 collected from three MTX-sensitive osteosarcoma (Saos-2) cell samples and three MTX-resistant osteosarcoma (Saos-2) cell samples were downloaded from Gene Expression Omnibus. After data processing, the differentially expressed genes (DEGs) were identified. Next, DEGs were submitted to DAVID for functional annotation based on the GO (Gene Ontology) database, as well as pathway enrichment analysis based on the KEGG (Kyoto Encyclopedia of Genes and Genomes) database. Transcription factors (TFs) and tumor-associated genes (TAGs) were identified with reference to TRANSFAC and TAG, and TSGene databases, respectively. The protein-protein interaction (PPI) network of the gene-encoded products was constructed, and the subnetwork with the highest score was also detected using Search Tool for the Retrieval of Interacting Genes and BioNet package. RESULTS: A total of 690 up-regulated genes and down-regulated 626 genes were identified. Up-regulated DEGs (including AARS and PARS2) were associated to transfer RNA (tRNA) aminoacylation while down-regulated DEGs (including AURKA, CCNB1, CCNE2, CDK1, and CENPA) were correlated with mitotic cell cycle. Totally, 13 TFs (including HMGB2), 13 oncogenes (including CCNA2 and AURKA), and 19 tumor suppressor genes (TSGs) (including CDKN2C) were identified from the down-regulated DEGs. Ten DEGs, including nine down-regulated genes (such as AURKA, CDK1, CCNE2, and CENPA) and one up-regulated gene (GADD45A), were involved in the highest score subnetwork. CONCLUSION: AARS, AURKA, AURKB, CENPA, CCNB1, CCNE2, and CDK may contribute to MTX resistance via aminoacyl-tRNA biosynthesis pathway, cell cycle pathway, or p53 signaling pathway.

Endothelial progenitor cells in atherosclerosis.

Endothelial progenitor cells (EPCs) are involved in the maintenance of endothelial homoeostasis and in the process of new vessel formation. Experimental and clinical studies have shown that atherosclerosis is associated with reduced numbers and dysfunction of EPCs; and that medications alone are able to partially reverse the impairment of EPCs in patients with atherosclerosis. Therefore, novel EPC-based therapies may provide enhancement in restoring EPCs' population and improvement of vascular function. Here, for a better understanding of the molecular mechanisms underlying EPC impairment in atherosclerosis, we provide a comprehensive overview on EPC characteristics, phenotypes, and the signaling pathways underlying EPC impairment in atherosclerosis.

Sorafenib down-regulates c-IAP expression post-transcriptionally in hepatic carcinoma cells to suppress apoptosis.

Hepatocellular carcinoma (HCC) is one of leading causes of cancer-related death with a heterogeneous patient demographic and divergent pathogenic pathways. Sorafenib is the first effective drug approved for the treatment of HCC. Although it is known that sorafenib promotes apoptosis of HCC cells, the underlying mechanism remains largely obscure. Here we report that sorafenib down-regulates protein expression of the anti-apoptotic protein c-IAP1 in a time- and dose-dependent manner in HCC cells in vitro and in vivo. Furthermore, we demonstrate that sorafenib represses c-IAP1 levels without altering its transcription or protein stability. Instead, sorafenib attenuates c-IAP1 translation by targeting the internal ribosome entry site (IRES) within the c-IAP1 mRNA. Finally, ectopic expression of c-IAP1 alleviates sorafenib induced cancer cell apoptosis. In conclusion, our data highlight a previously unidentified pathway that contributes to sorafenib mediated HCC cell apoptosis and as such provide novel mechanistic insight into the rational use of sorafenib in treating HCC.

Association of MDR1 gene polymorphisms with susceptibility to hepatocellular carcinoma in the Chinese population.

OBJECTIVE: The objective of this study was to evaluate the association of MDR1 gene polymorphisms with susceptibility to hepatocellular carcinoma (HCC). METHODS: A total of 689 HCC patients and 680 cancer-free subjects were enrolled. Human MDR1 gene polymorphisms were investigated by created restriction site- polymerase chain reaction (CRS-PCR) and DNA sequencing methods. Multiple logistic regression models were applied to estimate the association between MDR1 gene polymorphisms and susceptibility to HCC. RESULTS: We detected a novel c.4125A>C polymorphism and our findings suggested that this variant was significantly associated with susceptibility to HCC. A significantly increased susceptibility to HCC was noted in the homozygote comparison (CC versus AA: OR=1.621, 95% CI 1.143-2.300, χ2=7.4095, P=0.0065), recessive model (CC versus AC+AA: OR=1.625, 95% CI 1.167-2.264, χ2=8.3544, P=0.0039) and allele contrast (C versus A: OR=1.185, 95% CI 1.011-1.389, χ2=4.4046, P=0.0358). However, no significant increase was observed in the heterozygote comparison (AC versus AA: OR=0.995, 95% CI 0.794-1.248, χ2=0.0017, P=0.9672) and dominant model (CC+AC versus AA: OR=1.106, 95% CI 0.894-1.369, χ2=0.8560, P=0.3549). CONCLUSIONS: These findings suggest that the c.4125A>C polymorphism of the MDR1 gene might contribute to susceptibility to HCC in the Chinese population. Further work will be necessary to clarify the relationship between the c.4125A>C polymorphism and susceptibility to HCC on larger populations of diverse ethnicity.