Deep learning-based precise prediction and early detection of radiation-induced temporal lobe injury for nasopharyngeal carcinoma.

Background: Radiotherapy is the mainstay of treatment for nasopharyngeal carcinoma. Radiation-induced temporal lobe injury (TLI) can regress or resolve in the early phase, but it is irreversible at a later stage. However, no study has proposed a risk-based follow-up schedule for its early detection. Planning evaluation is difficult when dose-volume histogram (DVH) parameters are similar and optimization is terminated. Methods: This multicenter retrospective study included 6065 patients between 2014 and 2018. A 3D ResNet-based deep learning model was developed in training and validation cohorts and independently tested using concordance index in internal and external test cohorts. Accordingly, the patients were stratified into risk groups, and the model-predicted risks were used to develop risk-based follow-up schedules. The schedule was compared with the Radiation Therapy Oncology Group (RTOG) recommendation (every 3 months during the first 2 years and every 6 months in 3-5 years). Additionally, the model was used to evaluate plans with similar DVH parameters. Findings: Our model achieved concordance indexes of 0.831, 0.818, and 0.804, respectively, which outperformed conventional prediction models (all P < 0.001). The temporal lobes in all the cohorts were stratified into three groups with discrepant TLI-free survival. Personalized follow-up schedules developed for each risk group could detect TLI 1.9 months earlier than the RTOG recommendation. According to a higher median predicted 3-year TLI-free survival (99.25% vs. 99.15%, P < 0.001), the model identified a better plan than previous models. Interpretation: The deep learning model predicted TLI more precisely. The model-determined risk-based follow-up schedule detected the TLI earlier. The planning evaluation was refined because the model identified a better plan with a lower risk of TLI. Funding: The Sun Yat-sen University Clinical Research 5010 Program (2015020), Guangdong Basic and Applied Basic Research Foundation (2022A1515110356), Medical Scientific Research Foundation of Guangdong Province (A2022367), and Guangzhou Science and Technology Program (2023A04J1788).

Dosiomics Risk Model for Predicting Radiation Induced Temporal Lobe Injury and Guiding Individual Intensity-Modulated Radiation Therapy.

PURPOSE: We aimed to assess the value of dose distribution-based dosiomics and planning computed tomography-based radiomics to predict radiation-induced temporal lobe injury (TLI) and guide individualized intensity modulated radiation therapy. METHODS AND MATERIALS: A total of 5599 nasopharyngeal carcinoma patients were enrolled, including 2503, 1072, 988, and 1036 patients in the training, validation, prospective test, and external test cohorts, respectively. The concordance index (C-index) was used to compare the performance of the radiomics and dosiomics models with that of the quantitative analyses of normal tissue effects in the clinic and Wen's models. The predicted TLI-free survival rates of redesigned simulated plans with the same dose-volume histogram but different dose distributions for same patient in a cohort of 30 randomly selected patients were compared by the Wilcoxon matched-pairs signed-rank test. RESULTS: The radiomics and dosiomics signatures were constructed based on 30 selected computed tomography features and 10 selected dose distribution features, respectively, which were important predictors of TLI-free survival (all P <.001). However, the radiomics signature had a low C-index. The dosiomics risk model combining the dosiomics signature, D1cc, and age had favorable performance, with C-index values of 0.776, 0.811, 0.805, and 0.794 in the training, validation, prospective test, and external test cohorts, respectively, which were better than those of the quantitative analyses of normal tissue effects in the clinic model and Wen's model (all P <.001). The dosiomics risk model can further distinguish patients in a same risk category divided by other models (all P <.05). Conversely, the other models were unable to separate populations classified by the dosiomics risk model (all P > .05). Two simulated plans with the same dose-volume histogram but different dose distributions had different TLI-free survival rates predicted by dosiomics risk model (all P ≤ .002). CONCLUSIONS: The dosiomics risk model was superior to traditional models in predicting the risk of TLI. This is a promising approach to precisely predict radiation-induced toxicities and guide individualized intensity modulated radiation therapy.

Nitrate Quantification in Fresh Vegetables in Shanghai: Its Dietary Risks and Preventive Measures.

To investigate nitrate and nitrite content in fresh vegetables, 264 samples were randomly collected in the farmers' markets in Shanghai, Southeast China. The results indicate that 25.0% of the fresh vegetables were critically or more contaminated by nitrate [>1440 mg/kg FW (Fresh weight)]. Generally, leafy vegetables were more highly enriched in nitrate than root-tuber and fruit vegetables. About 22.6% of the leafy vegetables had a nitrate content exceeding the limit for edible permission (>3000 mg/kg FW). Nitrite content in the fresh vegetables was all within the safe level (<1 mg/kg FW). It was estimated that the daily nitrate intake through eating vegetables in Shanghai exceeded the WHO/FAO allowable limit. The field experiment indicated that the hyper-accumulation of nitrate and nitrite in the vegetables was mainly attributed to the excessive application of chemical fertilizers. The maxima of nitrate and nitrite in the vegetables were attained one week after applying chemical fertilizer, and thus they cannot be picked for dietary use. Applying organic manure can effectively lower the risk of nitrate and nitrite contamination in vegetables. The old leaves and leaf petioles were more easily enriched in nitrate due to their weaker metabolic activity. Vegetables with high nitrate content had a high risk of nitrite toxicity during storage due to the biological conversion of nitrate into nitrite, which is easily triggered by suitable temperature and mechanical damage processing. Therefore, fresh vegetables should be stored by rapid cooling and in undamaged forms to prevent nitrite accumulation.

UV-light-assisted gas sensor based on PdSe2/InSe heterojunction for ppb-level NO2 sensing at room temperature.

The fabrication of van der Waals (vdWs) heterostructures mainly extends to two-dimensional (2D) materials. Nevertheless, the current processes for obtaining high-quality 2D films are mainly exfoliated from their bulk counterparts or by high-temperature chemical vapor deposition (CVD), which limits industrial production and is often accompanied by defects. Herein, we first fabricated the type-II p-PdSe2/n-InSe vdWs heterostructure using the ultra-high vacuum laser molecular beam epitaxy (LMBE) technique combined with the vertical 2D stacking strategy, which is reproducible and suitable for high-volume manufacturing. This work found that the introduction of 365 nm UV light illumination can significantly improve the electrical transport properties and NO2 sensing performance of the PdSe2/InSe heterojunction-based device at room temperature (RT). The detailed studies confirm that the sensor based on the PdSe2/InSe heterojunction delivers the comparable sensitivity (Ra/Rg = ∼2.6 at 10 ppm), a low limit of detection of 52 ppb, and excellent selectivity for NO2 gas under UV light illumination, indicating great potential for NO2 detection. Notably, the sensor possesses fast response and full recovery properties (275/1078 s) compared to the results in the dark. Furthermore, the mechanism of enhanced gas sensitivity was proposed based on the energy band alignment of the PdSe2/InSe heterojunction with the assistance of investigating the surface potential variations. This work may pave the way for the development of high-performance, room-temperature gas sensors based on 2D vdWs heterostructures through the LMBE technique.

Effect of Roucongrong (Herba Cistanches Deserticolae) decoction on the substantia nigra through Wnt/ß-catenin signaling pathway in rats with Parkinson's disease induced by 6-hydroxydopamine hydrochloride.

OBJECTIVE: To investigate the effect of Roucongrong (Herba Cistanches Deserticolae) decoction on the substantia nigra in rats with Parkinson's disease (PD) induced by 6-hydroxydopamine hydrochloride (6-OHDA). To further determine whether the Wnt/ß-catenin signaling pathway is involved in the action. METHODS: A rat model of PD was established by intracranial injection of 6-OHDA. Subsequently, three concentrations of Roucongrong (Herba Cistanches Deserticolae) decoction were prepared and administered to rats by gavage therapy for 14 d. Behavioral changes were measured in PD rats. In vivo tyrosine hydroxylase (TH) levels in the substantia nigra were examined by immunohistochemistry. Additionally, gene and protein expression levels of members of the Wnt/ß-catenin signaling pathway were examined by Western blotting and polymerase chain reaction. Lastly, a Wnt/ß-catenin inhibitor was used to investigate the mechanism of action in 1-methyl-4-phenylpyridinium (MPP + )- treated MES23.5 cells in vitro. RESULTS: Roucongrong (Herba Cistanches Deserticolae) decoction improved performance in the stride and gait adjustment tests in PD rats. It also increased TH in the substantia nigra and altered the expression of genes and proteins in the Wnt/ß-catenin signaling pathway. Wnt/ß-catenin inhibitor reduced the effect of Roucongrong (Herba Cistanches Deserticolae) decoction in MPP +-treated MES23.5 cells. CONCLUSION: Roucongrong (Herba Cistanches Deserticolae) decoction may promote neuronal survival in PD in vivo and in vitro by increasing TH content in the substantia nigra and by activating the Wnt/ß-catenin signaling pathway.

Assessment of Survival Model Performance Following Inclusion of Epstein-Barr Virus DNA Status in Conventional TNM Staging Groups in Epstein-Barr Virus-Related Nasopharyngeal Carcinoma.

Importance: Nonanatomic prognostic factors complement the traditional anatomic staging system and could be incorporated into the tumor-node-metastasis (TNM) framework. Several diseases have incorporated nonanatomic prognostic factors into the determination of TNM staging groups. Objective: To refine TNM staging groups for Epstein-Barr virus (EBV)-related nonmetastatic nasopharyngeal carcinoma (NPC) by incorporating EBV DNA status. Design, Setting, and Participants: This multicenter prognostic study included patients with NPC treated with radiotherapy at 2 hospitals in China from January 2008 to December 2016. Progression-free survival and overall survival according to EBV DNA status and the TNM staging system were compared. Recursive partitioning analysis (RPA) combined with supervised clustering was applied to derive prognostic groupings, and then a refined RPA staging schema was developed, validated, and compared with existing staging schemes. Statistical analyses were conducted from October 1, 2020, to June 15, 2021. Exposures: Curative intensity-modulated radiotherapy with or without platinum-based chemotherapy. Main Outcomes and Measures: The primary end point was progression-free survival. The performance of the staging system was assessed using the time-dependent area under the receiver operating characteristic curves and the TNM stage system's evaluation methodology. Results: A total of 2354 patients (1709 men [72.6%]; median [interquartile range] age, 45 [38-53] years) were split into training (1372 [58.3%]), internal validation (672 [28.5%]), and external validation (310 [13.2%]) cohorts. Pretreatment EBV DNA was detected in 1338 (56.8%) patients. EBV DNA status was an independent prognostic factor: lower survival probability by higher TNM stage was evident in EBV DNA-positive patients but not in those with EBV DNA-negative disease. After integrating EBV DNA status and TNM stage, nonmetastatic NPC cases were categorized into RPA-I (T1-3N0 or EBV DNA-negative T1-3N1 cancers), RPA-II (EBV DNA-positive T1-3N1-2 or EBV DNA-negative T1-3N2-3/T4N0-3 cancers), and RPA-III (EBV DNA-positive T4N0-3/T1-3N3 cancers) groups, each with distinctly different prognosis. This system of RPA staging outperformed the current TNM stage system and 2 reported RPA staging schemes. These results were internally and externally validated. Conclusions and Relevance: An RPA-based staging system for EBV-related NPC cases was associated with improved outcomes. This staging system may facilitate prognostic stratification and clinical trial designs.

Evaluation of the efficiency and safety of botulinum toxin A injection on improving facial scars: A protocol for systematic review and meta-analysis.

BACKGROUND: Botulinum toxin A injection is an established method of treatment. Clinical practitioners use it widely in their practice to prevent the occurrence of facial scars. However, the effectiveness and safeness of has not been comprehensively established. The objective of the current systematic review is to evaluate the efficacy and safety of using botulinum toxin A injection to improve facial scars. METHODS AND ANALYSIS: This systematic review involves browsing a number of electronic databases to search for related articles. The search will include databases in both English (PubMed, EMBASE, Web of Science, Spocus, and Cochrane Central Register of Controlled Trials) and Chinese (WanFang database, China Nation Knowledge Infrastructure, and VIP database), the periods of searching will be from inception till the 15th of September 2020. Completing the search in databases allows to consider randomized controlled studies that compares botulinum toxin A interventions to any comparison interventions in those who have facial scars. The review will be inclusive of papers in both languages, English and Chinese. The independent screening of studies for eligibility is conducted by 2 independent authors. Discussion was used to resolve discrepancies between the authors. The Cochrane Risk of Bias Tool V.2.0 is adopted for evaluating the methodological quality of each study. Data extraction was performed by 2 independent authors. For dichotomous outcomes, the were expressed as relative risk (RR) with 95% confidence intervals (CI). For continuous outcomes the results were expressed as the mean difference (MD) or standardized mean difference (SMD) with 95% CI. The statistical analysis of the present study is carried out in RevMan 5.3 software. RESULTS: This study will output a comprehensive synthesis of existing evidence in relation to botulinum toxin A. Moreover, the results will also provide an interpretation of the effectiveness and safety of botulinum toxin A. CONCLUSION: The present review contributes to the existing body of knowledge by adding more evidence to evaluate if botulinum toxin A is effective and safe to be used as an intervention for improving facial scars. OSF REGISTRATION NUMBER: DOI 10.17605/OSF.IO/94TXP (https://osf.io/94TXP/).

Mercury exposure, cardiovascular disease, and mortality: A systematic review and dose-response meta-analysis.

BACKGROUND: There is evidence that exposure to mercury (Hg) may be a risk factor for cardiovascular disease (CVD). OBJECTIVE: To conduct a systematic review of published studies and a meta-analysis of the results to examine the associations between chronic Hg exposure and CVD outcomes. METHODS: We searched PubMed, Embase, and TOXLINE using previously developed strategies. Studies were selected according to a priori-defined inclusion criteria, and their qualities were assessed. Study estimates were extracted, and subgroup analyses were conducted to explore potential sources of heterogeneity: 1) fatal vs. nonfatal events, 2) cohort study vs. non-cohort study, and 3) inorganic Hg vs. methyl mercury (MeHg). Dose-response meta-analyses were conducted for MeHg exposure and fatal/nonfatal ischemic heart disease (IHD), stroke, and all CVD. RESULTS: A total of 14 studies reporting results collected from more than 34,000 participants in 17 countries were included in the meta-analysis. Hg exposure was associated with an increase in nonfatal IHD (relative risk (RR): 1.21 (0.98, 1.50)), all-cause mortality (RR: 1.21 (0.90, 1.62)), CVD mortality (RR: 1.68 (1.15, 2.45)), and mortality due to other heart diseases (RR: 1.50 (1.07, 2.11)). No association was observed between Hg exposure and stroke. A heterogeneous relationship was found between studies reporting fatal and nonfatal outcomes and between cohort and non-cohort studies. However, these differences were mainly due to differences in Hg exposure level. Occupational inorganic Hg exposure was associated with similar increases in different mortality outcomes. A J-shaped relationship between Hg exposure and different fatal/nonfatal outcomes was observed, with turning points at hair Hg concentrations of 1 µg/g for IHD and 2 µg/g for stroke and all CVD. CONCLUSION: Chronic exposure to Hg was associated with an increased risk of all-cause mortality and fatal/nonfatal IHD. The risk of multiple cardiovascular endpoints starts to increase consistently at a hair Hg concentration of 2 µg/g.

Inhibition or Facilitation? Contrasted Inter-Specific Interactions in Sphagnum under Laboratory and Field Conditions.

In a natural environment, plants usually interact with their neighbors predominantly through resource competition, allelopathy, and facilitation. The occurrence of the positive effect of allelopathy between peat mosses (Sphagnum L.) is rare, but it has been observed in a field experiment. It is unclear whether the stability of the water table level in peat induces positive vs. negative effects of allelopathy and how that is related to phenolic allelochemical production in Sphagnum. Based on field experiment data, we established a laboratory experiment with three neighborhood treatments to measure inter-specific interactions between Sphagnum angustifolium (Russ.) C. Jens and Sphagnum magellanicum Brid. We found that the two species were strongly suppressed by the allelopathic effects of each other. S. magellanicum allelopathically facilitated S. angustifolium in the field but inhibited it in the laboratory, and relative allelopathy intensity appeared to be positively related to the content of released phenolics. We conclude that the interaction type and intensity between plants are dependent on environmental conditions. The concentration of phenolics alone may not explain the type and relative intensity of allelopathy. Carefully designed combined field and laboratory experiments are necessary to reveal the mechanism of species interactions in natural communities.

Cohort profile: health effects monitoring programme in Ndilǫ, Dettah and Yellowknife (YKHEMP).

PURPOSE: The Yellowknife Health Effects Monitoring Programme (YKHEMP) was established to examine the relationship of exposure to arsenic and other chemicals of potential concern such as antimony, cadmium, lead, manganese and vanadium and health outcomes. PARTICIPANTS: A total of 2037 individuals were recruited, including children (age 3-19) and adults (age 20+), residing in Dettah, NdilÇ« and Yellowknife, in the Northwest Territories, Canada, in two waves in Fall 2017 and Spring 2018. In Yellowknife, there were 891 (675 adults, 216 children), randomly selected participants with a participation rate of 64%. In addition, we also recruited a total of 875 (669 adults, 206 children) volunteer participants. A total of 225 (137 adults, 88 children) of the Yellowknives Dene First Nation (YKDFN), and 46 (33 adults, 13 children) of the North Slave Métis Alliance participated in the study. Each participant answered a lifestyle questionnaire as well as provided toenail clippings and urine for contaminant testing and saliva samples for testing of genetic polymorphisms associated with arsenic metabolism. Participants also provided consent to have their medical records reviewed by the research team for the past 5 years to allow for the investigation between exposure and health outcomes. FINDINGS TO DATE: The adult YKHEMP participants had lower urinary total arsenic but the children had higher inorganic arsenic than the general Canadian population. There was no difference in urinary total arsenic concentrations between adults and children, however, urinary inorganic arsenic concentrations were generally higher in children than in adults in all four YKHEMP sampling groups. The adult YKDFN participants had lower urinary total arsenic and inorganic arsenic concentrations compared with the random selected and volunteer participants. FUTURE PLANS: YKHEMP is designed as a prospective cohort study; the children participants will be re-examined in 2022 and both adult and children participants in 2027.

Health risk assessment of arsenic exposure among the residents in Ndilǫ, Dettah, and Yellowknife, Northwest Territories, Canada.

There are concerns in Yellowknife, Northwest Territories, Canada, about arsenic exposure due to past mining operations, particularly the former Giant Mine. The objective of this study was to characterize the risk of arsenic exposure and associated risk factors among the local residents. Arsenic (As) and its species were quantified in urine (n = 1966) using inductively coupled mass spectrometry. Children in the study were found to have significantly higher (p < 0.05) urinary inorganic-related As (uiAs) concentrations than children in the general Canadian population, as well as adults in the study. Additionally, uiAs concentrations in children, particularly those above the 95th percentile, are above the Biomonitoring Equivalents (BE) levels that are associated with dermal effects, vascular problems and cancer risks. Multiple linear regression results showed that market seafood (fish and shellfish) and rice consumption frequency were significantly positively associated with uiAs. Specific to children, drinking lake water was positively associated with uiAs. Specific to adults, consumption of local mushrooms and berries were significantly positively associated with uiAs while there was a significant negative association with age, smoking and recreational water activities. The risk factors identified in this research can be used for public health education to lower arsenic intake. Overall, these results support the need for an ongoing monitoring program.

Perinatal risk factors for pulmonary hemorrhage in extremely low-birth-weight infants.

BACKGROUND: Pulmonary hemorrhage (PH) is a life-threatening respiratory complication of extremely low-birth-weight infants (ELBWIs). However, the risk factors for PH are controversial. Therefore, the purpose of this study was to analyze the perinatal risk factors and short-term outcomes of PH in ELBWIs. METHODS: This was a retrospective cohort study of live born infants who had birth weights that were less than 1000 g, lived for at least 12 hours, and did not have major congenital anomalies. A logistic regression model was established to analyze the risk factors associated with PH. RESULTS: There were 168 ELBWIs born during this period. A total of 160 infants were included, and 30 infants were diagnosed with PH. Risk factors including gestational age, small for gestational age, intubation in the delivery room, surfactant in the delivery room, repeated use of surfactant, higher FiO2 during the first day, invasive ventilation during the first day and early onset sepsis (EOS) were associated with the occurrence of PH by univariate analysis. In the logistic regression model, EOS was found to be an independent risk factor for PH. The mortality and intraventricular hemorrhage rate of the group of ELBWIs with PH were significantly higher than those of the group of ELBWIs without PH. The rates of periventricular leukomalacia, moderate-to-severe bronchopulmonary dysplasia and severe retinopathy of prematurity, and the duration of the hospital stay were not significantly different between the PH and no-PH groups. CONCLUSIONS: Although PH did not extend hospital stay or increase the risk of bronchopulmonary dysplasia, it increased the mortality and intraventricular hemorrhage rate in ELBWIs. EOS was the independent risk factor for PH in ELBWIs.

Seafood Consumption and Its Contribution to Nutrients Intake among Canadians in 2004 and 2015.

Fish and seafood are excellent sources of nutrients such as omega-3 fatty acids, Vitamin D, and selenium. The aims of this study were to examine the pattern of seafood consumption among Canadians and determine their contribution to intakes of energy and nutrients. Day-1 24-h dietary recalls data collected from a national survey, the Canadian Community Health Survey-Nutrition in 2004 and 2015, were used to estimate food and nutrient intakes among Canadians. Seafood was classified according to the Bureau of Nutritional Sciences food list. Descriptive statistics were used to calculate the consumption rate and the average consumption amount of seafood by different age groups and sociodemographic characteristics. Population ratios were used to assess the contribution of seafood to the total intake of energy and nutrients. The overall consumption rate of seafood was around 17%, and the rate was similar between males and females, and slightly higher in 2015 (17.71%) compared to 2004 (16.38%). The average portion size is approximately 100 g, which translates into a ≈36 kg annual intake among the consumers and ≈6.2 kg per capita consumption. Adults (especially 30 years and above), Asians, individuals who were married, and with post-secondary education were more likely to consume seafood. Salmon, tuna, shrimp, cod, and crab were the most frequently consumed seafood in Canada, the consumption rate of which all increased from 2004 to 2015. Seafood provided up to 75% of n-3 PUFAs, 18% of Vitamin D, 19% Vitamin B12, 6% of niacin, and 4% of Vitamin B6 from all food sources. Seafood consumers had a healthier diet, as seafood consumption was related to a higher intake of key nutrients and a lower intake of total sugar and saturated fatty acids. Therefore, fish consumption should be promoted among Canadians.

Circulating Selenium Concentration Is Inversely Associated With the Prevalence of Stroke: Results From the Canadian Health Measures Survey and the National Health and Nutrition Examination Survey.

Background Observational studies have suggested that selenium (Se) may have beneficial effects against certain cardiovascular outcomes, with a possible U-shaped association. We assessed the hypothesis that blood Se concentration might be inversely associated with the prevalence of stroke and the relationship would be nonlinear. Methods and Results Data collected from adult participants (aged ≥20 years) in the Canadian Health Measures Survey ( CHMS 2007-2011, n=7065) and the US National Health and Nutrition Examination Survey ( NHANES 2011-2012, n=5030) were analyzed. A total of 82 (1.16%) and 202 (4.02%) stroke cases were identified in CHMS and NHANES . Respondents with stroke had lower Se levels than those without stroke, with a mean difference of 16 µg/L and 12 µg/L for CHMS and NHANES , respectively. Respondents with high blood Se concentration (tertile 3) had a lower prevalence of stroke compared with those with low Se concentration (tertile 1). The adjusted odds ratios were 0.38 (95% CI : 0.15, 0.92) and 0.57 (95% CI : 0.31, 1.03) for CHMS and NHANES , respectively. A continuous decreasing trend of stroke with whole blood selenium was observed in CHMS , whereas the curve plateaued starting at 190 µg/L for NHANES , based on the cubic restricted spline regression. Sensitivity analysis using the serum and urinary Se concentrations demonstrates that our results were consistent across different selenium biomarkers. Conclusions We observed inverse cross-sectional associations between whole blood Se and the prevalence of stroke in representative samples of the Canadian and the US population.

Hydrothermal derived protoporphyrin IX nanoparticles for inactivation and imaging of bacteria strains.

Overuse and abuse of antibiotics greatly hasten the development of microbial drug resistance and substantially threat to global public health. Developing alternative methods for combating bacterial infections is urgently required. In this work, a simple hydrothermal approach was employed to prepare the protoporphyrin IX-polyethylenimine nanoparticles (PPIX-PEI NPs) containing abundant amine groups and PPIX moieties. The as-obtained PPIX-PEI NPs exhibit antibacterial properties against both Gram-positive and Gram-negative bacteria. The presence of PPIX in the PPIX-PEI NPs can generate reactive oxygen species (ROS) under 635 nm laser irradiation, which enhance the antibacterial properties of the PPIX-PEI NPs against Gram-positive bacteria. Thus, the PPIX-PEI NPs display a synergistic antibacterial activity against Gram-positive bacteria in the combination of antibacterial photodynamic therapy (PDT). In addition, emission of red fluorescence by the PPIX-PEI NPs can help to differentiate bacteria and observe the bacterial morphologies using a confocal laser scanning microscope (CLSM).

Deposition of catechol-functionalized chitosan and silver nanoparticles on biomedical titanium surfaces for antibacterial application.

The titanium (Ti) and its alloys have been widely used for dental and orthopedic implants. However, the Ti-based implants may suffer from bacterial infection, which would result in insufficient healing, implant failure and repeated surgical intervention. It is of great interest to inhibit the bacterial adhesion and colonization on the Ti-based implants by introducing proper surface coatings. In this work, a simple method was employed to synthesize the water-soluble catechol-containing chitosan (CACS). The CACS coatings can be deposited onto various substrate surfaces and exhibit substrate-independent behavior. The CACS-coated Ti surfaces were further deposited with silver nanoparticles (Ag NPs) via in-situ reduction of Ag+ ions using catechol moieties as the reducing agents. The resulting AgNPs/CACS-coated Ti surfaces exhibit antibacterial properties and can prevent the surface adhesion of bacterial cells, as evidenced by the inhibition zone test, live/dead bacterial staining assay and spread plate method. In addition, they show negligible cytotoxicity to L929 mouse fibroblast cells.

Potential impact of restricted caribou (Rangifer tarandus) consumption on anemia prevalence among Inuit adults in northern Canada.

BACKGROUND: Caribou (Rangifer tarandus) is the top dietary source of iron and several micronutrients necessary for red blood cell production (erythropoiesis) in the contemporary diet of Inuit adults across Canada. Many caribou populations across the circumpolar north, however, have experienced dramatic declines in recent decades. Restricted access to caribou may negatively impact the nutrition and health of Inuit communities. METHODS: We used data from the Inuit Health Survey, a cross-sectional survey of 2550 Inuit adults in thirty-six communities across northern Canada (conducted in 2007-2008) to examine the relationship between caribou consumption, hemoglobin (Hb), and blood biomarkers of nutrient intake and contaminant exposure. Multivariable linear regression was used to investigate the potential public health impact of a theoretical restriction in caribou consumption, by estimating the response of Hb concentrations (and the attendant change in anemia prevalence), to theoretical changes in caribou consumption (with and without substitution of caribou with other country food meat). RESULTS: Mean (95% CI) daily caribou meat consumption differed by an order of magnitude 4.3 (3.9-4.7), 51.1 (48.5-53.8), and 236.7 (224.7-248.7) grams/day between tertiles of caribou consumption. Mean (95% CI) hemoglobin levels increased from 129.1 (128.1-130.2) g/L to 132.5 (131.3-133.7) g/L between the highest and lowest tertiles of caribou consumption. In multivariable regression analyses, average daily caribou meat consumption was positively associated (P< 0.001) with hemoglobin levels. This relationship translated into approximately 4 g/L hemoglobin increase in participants in the third tertile of caribou consumption. The overall prevalence of anemia observed in the study population was 26.5% (24.5 - 28.3%) and a modelled restriction in caribou consumption (i.e. caribou = 0) increased the overall prevalence of anemia by approximately 6%. The maximum negative effect of caribou restrictions was related to a complete restriction on caribou consumption, coupled with the substitution of caribou with other country food meat (35.4% prevalence). CONCLUSIONS: Given the importance of caribou to Inuit culture, health and wellbeing, and the high price of healthful market foods in remote northern communities, strategies to promote the sustainable harvest of country foods are urgently required to ensure the health and nutrition security of the Inuit, in the context of rapidly changing Arctic environments and ecosystems.

Exposure to triclosan among the Canadian population: Results of the Canadian Health Measures Survey (2009-2013).

Triclosan is a broad-spectrum antimicrobial additive in consumer products that has been detected in human populations globally. The purpose of this study was to assess triclosan exposure among the Canadian population using urinary triclosan as a biomarker. Data from the Canadian Health Measures Survey (CHMS) that reported triclosan concentrations in 8195 urine samples collected from Cycle 2 (2009-2011) and Cycle 3 (2012-2013) were analyzed. Triclosan was detected in 69.8% of samples with the geometric mean concentrations of 16 µg/L (16 µg/g creatinine) for the total population, 13 µg/L (13 µg/g creatinine) for children (3-19 years of age), and 16 µg/L (17 µg/g creatinine) for adults. Triclosan concentrations significantly differed by age, income, education, and employment in healthcare occupations, but not by race/ethnicity, sex, region of residence, or drinking water preferences or sources. Linear regression models were used to identify factors associated with urinary triclosan concentration. Results showed that household income was associated with higher urinary triclosan concentrations in both children and adults. Employed in healthcare occupations were associated with higher urinary triclosan concentrations in adults. Triclosan exposure at the 99th percentile was below the Biomonitoring Equivalents based on reference dose, suggesting that health risks to the Canadian population from triclosan exposure were low.

Prevalence of heart attack and stroke and associated risk factors among Inuit in Canada: A comparison with the general Canadian population.

BACKGROUND: It is generally believed that cardiovascular disease (CVD) is rare in the Inuit population because of their traditional marine-based diet, but the evidence is inconsistent. OBJECTIVE: To describe the cardiovascular health profile of Canadian Inuit, including disease prevalence, risk factors, country food consumption, and contaminant exposure, and compare to that of the general Canadian population. METHODS: Cardiovascular outcomes and risk factors were obtained for 2070 Inuit adults aged 20-79 years from the Inuit Health Survey (IHS, 2007-2008) and for 3464 general Canadian adults aged 20-79 years from the Canadian Health Measures Survey, Cycle 1 (CHMS, 2007-2009) and Cycle 3 (2012-2013). Sex- and age-specific (20-39, 40-59, 60-79) estimates are reported. To compare results between the IHS and CHMS, age-standardized estimates were calculated for males and females, using the CHMS as the reference population. RESULTS: Inuit had higher prevalence of heart attack (3.1% vs. 1.8% females), stroke (2.1% vs. 0.8% males and 2.2% vs. 1.0% females), diabetes (14.6% vs. 9.0% elderly females), obesity (35.8% vs. 24.2% females), and hypertension (12.2% vs. 2.5% young males and 7.5% vs. 2.5% young females). However, Inuit had better blood lipid profile (hyperlipidemia: 29.0% vs. 46.5% males and 28.4% vs. 35.2% females). Metals and persistent organic pollutant exposures were higher among the Inuit compared with general Canadians. CONCLUSION: Inuit and the general Canadian population differ in cardiovascular health profiles. Further research is needed to characterize the health transition among Inuit, especially among the youth and female.

Factors associated with the blood and urinary selenium concentrations in the Canadian population: Results of the Canadian Health Measures Survey (2007-2011).

OBJECTIVE: The objective of the present work is to assess the factors associated with whole blood and urinary selenium (Se) concentrations in Canadians aged 6-79 years old, and to interpret the data in the context of exposure guidance values. METHODS: Whole blood Se concentrations data collected from 10740 participants as part of the Canadian Health Measures Survey (CHMS) Cycle 1 (2007-09) and Cycle 2 (2010-11) were analyzed for associations with the demographic and dietary characteristics of the Canadian population; whereas the urinary Se concentrations were only assessed for their association with the demographic variables. Whole blood and urinary Se concentrations were compared to biomonitoring equivalents established for exposure guidance values. RESULTS: The geometric means of whole blood Se concentrations (µg/L) were 197.42 (95% CI: 194.79, 200.08) and 192.35 (95% CI: 189.68, 195.06) for males and females, respectively. The corresponding urinary Se concentrations (µg/L) were 56.91 (95% CI: 54.81, 59.10) and 44.10 (95% CI: 41.89, 46.43) respectively. Males, participants born in Asia, older individuals, and participants who frequently consumed nuts and vegetables had higher whole blood Se, whereas current smokers, residents of Quebec and Ontario, participants who frequently consumed meat, fruits or dairy products were associated with lower whole blood Se. Sociodemographic factors were also significantly associated with urinary Se although the direction of association sometimes differed from those observed with blood Se. More than 99.9% of the Canadian population covered by the survey had whole blood Se concentrations within the range from the lower (100 µg/L) and higher (400 µg/L) biomonitoring equivalents set for the protection from deficiency and selenosis, respectively. CONCLUSIONS: The CHMS data provide a baseline for Se exposure among Canadians and indicated that the population is generally not at risk of deficiency or toxicity.