Mental health and academic outcomes over the first year at university in international compared to domestic Canadian students

OBJECTIVE

To compare risk factors and associated mental health and academic outcomes between international and domestic students.

PARTICIPANTS

Canadian university undergraduate students.

METHODS

Electronic surveys were completed at university entry and the end of first year. Surveys assessed demographics, risk factors, symptoms of mental disorders, and access to support. Academic outcomes were obtained from university databases.

RESULTS

International students had comparable or lower rates of clinically significant anxiety, depression, and insomnia. Domestic female students reported the highest screening rates for common mental disorders. However, international students were more likely to report having attempted suicide. International students felt less connected to the university community and had lower academic performance. Psychosocial risk factor profiles and proportions accessing mental health services were similar.

CONCLUSIONS

The scope of mental health need appears more similar than different between international and domestic students; however, international students may benefit from targeted academic and social support initiatives.

Passivation effect on Cd0.95Mn0.05Te0.98Se0.02 radiation detection performance

CdTe-based detectors have the problem of Te-rich surface layers caused by Br etching, which is one of fabrication steps. Te-rich layer acts as a trapping center and serves as an additional source of charge carriers, thereby degrading transport property of charge carriers and enriching leakage current on surface of detector. To solve this problem, we introduced sodium hypochlorite (NaOCl) as a passivant, and investigated its effect on Cd0.95Mn0.05Te0.98Se0.02 (CMTS), by analyzing chemical state of surface and its performance. After passivation with NaOCl, the results of X-ray photoelectron spectroscopy (XPS) shows the formation of tellurium oxide and elimination of water on CMTS surface, and CMTS presented enhanced performance with Am-241 radioisotope. Consequently, it is demonstrated that the passivation with NaOCl reduces leakage current, compensates defect, and elevates transport of charge carriers, thereby decreasing charge loss of carriers and improving performance of CMTS detector.

Development and evaluation of photon-counting Cd0.875Zn0.125Te0.98Se0.02 detector for measuring bone mineral density

Cadmium zinc telluride (CZT) has been actively researched and developed by researchers in various fields. In medical applications, especially photon-counting, CZT enables improved image quality, multi-material decomposition, and improved dose efficiency. Moreover, band gap engineering and selenium addition on CZT improved electrical, spectroscopic and structural properties, thereby supporting performance of CZT as a photon-counting detector. In this study, it is shown that Cd_0.875Zn_0.125Te_0.98Se_0.02 (CZTS) shows sufficient performance without loss of detection efficiency. We carried out a study involving the application of this CZTS on calculating bone mineral density (BMD) values, because this application has a novelty of new material for BMD sensor which follows the CdTe- or CdZnTe- based BMD detector. Anatomical images from different energy bins contained different information of attenuation although the images were taken in the same region at the same time. Moreover, calculated BMD values had a proper tendency depending on the amount of bone in that region. The final BMD value was 1.1972 g/cm², which is close to the real value of 1.2 g/cm². The introduction with a bone filter and a smaller pixel size will improve the accuracy and precision of photon-counting CZTS detectors for measuring BMD values. However, in this study the CZTS showed the feasibility that a photon-counting CZTS detector can help the measurement of BMD values and the diagnosis of osteoporosis.

1197 Utility of Fitbit Charge 2 for Sleep Monitoring in Patients With Obstructive Sleep Apnea

Introduction

The wearable device may be useful in monitoring sleep. Many studies reported reliable data in detecting sleep-wake states and sleep stage proportion in healthy adults, However, only a few validation studies were performed evaluating sleep using the wearable devices in patients with obstructive sleep apnea(OSA), which showed insufficient accuracy. We aimed to evaluate the reliability of multi-sensory wristband (Fitbit Charge 2) in patients with OSA.

Methods

This was a preliminary analysis of a prospective single-center observational study. Consecutive patients underwent standard Polysomnography (PSG) for evaluation of OSA with Fitbit Charge 2. Sleep data from PSG and Fitbit charge 2 were compared using paired t-tests and Bland-Altman plots.

Results

A total of eighty-six patients were analyzed. Four of them had poor data quality, 18 of them did not show sleep stages. Compared with the PSG, Fitbit Charge 2 showed higher total sleep time (419.1±194.0 vs 269.8±22.6, p<0.001) and sleep efficiency (95.8±2.5 vs 84.6±7.1, p<0.001). Those with sleep stage data showed higher sleep efficacy (87.7±5.5 vs 82.37.5, p=0.024) and a lower proportion of N1 sleep (33.7±19.9 vs 65.3±38.8, p=0.01).

Conclusion

Fitbit Charge 2 showed limited utility in monitoring sleep in patients with obstructive sleep apnea.

Support

none

Occupational exposure and idiopathic pulmonary fibrosis: a multicentre case-control study in Korea

SETTING

Multicentred hospital-based cases and control subjects in Korea.

OBJECTIVE

To evaluate the association between idiopathic pulmonary fibrosis (IPF) and hazardous materials to which people are occupationally exposed.

DESIGN

A multicentre, hospital-based, matched case-control study was performed. The ratio of IPF cases to controls was 1:1 (n = 78 in each group). IPF cases and controls were matched in terms of age group, sex and place of residence. Conditional logistic regression analysis was performed.

RESULTS

In simple logistic regression analysis, exposure to metal dust and any exposure for >1 year in an occupational setting were significantly associated with IPF (metal dust OR 4.00, 95%CI 1.34-11.97; any exposure OR 3.67, 95%CI 1.02-13.14). After adjustment for environmental and military exposures and smoking history, the OR for metal dust exposure was 4.97 (95%CI 1.36-18.17) in multiple logistic regression analysis.

CONCLUSIONS

Metal dust was associated with incident IPF in Seoul and Gyeonggi Provinces in Korea. This information will be used to support a tailored preventive strategy in specific industries or occupations.

Rapid extraction of uranium ions from seawater using novel porous polymeric adsorbents

Nanoporous polymeric networks, are firstly exploited for uranium capture from seawater. Amidoxime PIM-1 is capable of uptake 95% of uranium in 24 h, and the U extraction efficiency is to be intact throughout three cycles of sorbent regeneration.

Observation of the wrapping mechanism in amine carbon dioxide molecular interactions on heterogeneous sorbents

CO₂ binds multiple amines if nearby, leading to higher heats of adsorption, a previously unknown observation.

CR6-interacting factor 1 is a key regulator in Aβ-induced mitochondrial disruption and pathogenesis of Alzheimer's disease

Mitochondrial dysfunction, often characterized by massive fission and other morphological abnormalities, is a well-known risk factor for Alzheimer's disease (AD). One causative mechanism underlying AD-associated mitochondrial dysfunction is thought to be amyloid-β (Aβ), yet the pathways between Aβ and mitochondrial dysfunction remain elusive. In this study, we report that CR6-interacting factor 1 (Crif1), a mitochondrial inner membrane protein, is a key player in Aβ-induced mitochondrial dysfunction. Specifically, we found that Crif1 levels were downregulated in the pathological regions of Tg6799 mice brains, wherein overexpressed Aβ undergoes self-aggregation. Downregulation of Crif1 was similarly observed in human AD brains as well as in SH-SY5Y cells treated with Aβ. In addition, knockdown of Crif1, using RNA interference, induced mitochondrial dysfunction with phenotypes similar to those observed in Aβ-treated cells. Conversely, Crif1 overexpression prevented Aβ-induced mitochondrial dysfunction and cell death. Finally, we show that Aβ-induced downregulation of Crif1 is mediated by enhanced reactive oxygen species (ROS) and ROS-dependent sumoylation of the transcription factor specificity protein 1 (Sp1). These results identify the ROS-Sp1-Crif1 pathway to be a new mechanism underlying Aβ-induced mitochondrial dysfunction and suggest that ROS-mediated downregulation of Crif1 is a crucial event in AD pathology. We propose that Crif1 may serve as a novel therapeutic target in the treatment of AD.

Dilute-acid pretreatment of distillers' grains and corn fiber

Distillers' grains and corn fiber are the coproducts of the dry grind and wet corn milling industries, respectively. Availability of distillers' grains and corn fiber at the ethanol plant and their high levels of lignocellulosic material make them attractive feedstock for conversion to ethanol. In this study, dilute sulfuric acid hydrolysis for the conversion of distillers' grains and corn fiber to monomeric sugars and the formation of furfural were investigated. The extent of solubilization of biomass beyond monomeric sugars was also monitored. Biomass loadings in the range of 5-20 wt.% at 5% intervals, acid concentrations in the range of 0.5-1.5 vol.% at 0.5% intervals, and temperatures of 120 and 140 degrees C were studied. The highest yields of monomeric sugars were observed when the least amount of biomass loading was pretreated with the highest concentration of sulfuric acid and when the temperature was 140 degrees C. For the majority of the cases under consideration, the most effective period of hydrolysis appeared to be during the initial 20-30 min of the reaction. Formation of furfural during the course of hydrolysis was significantly lower at 120 degrees C and also lower for the distillers' grains samples compared with the corn fiber samples. The total amount of the solubilized matter during the hydrolysis was significantly higher than the amount of the monomeric sugars. Analyses according to standard procedure were performed to quantify moisture, oil, carbohydrates, and ash in distillers' grains and corn fiber samples. The total carbohydrate content of distillers' grains and corn fiber were 57.7+/-2.0 and 77.0+/-1.0 wt.%, respectively. The presented results will provide a foundation for the suitability of the pretreated distillers' grains and corn fiber for enzymatic hydrolysis step.

Prognostic significance of metabolic adaptation for hypoxic environment in oral squamous cell carcinoma

6082

Background: During tumor growth, tumor adapts the hypoxic environment and increases glycolysis. This metabolic switch is related to the aggressive malignant behavior. We investigated the connection between the biomarkers related to the glycolytic metabolism (HIF-1α, PDK-1, LDH-5) and clinicopathologic characteristics in oral cavity and oropharynx squamous cell carcinoma (SCC). Methods: Eligibility criteria was the patients diagnosed oral SCC, received curative radical resection and had available tissue samples. Immunohistochemical stain of the HIF-1α, PDK-1, and LDH-5 was done. Statistical analysis was performed to compare biomarkers between patients and time point. Results: Overall 74 patients were enrolled and stage grouping of the patients was as follows: stage I, 25 (33.8%) patients; stage II 17 (23.0%); stage III 8 (10.8%); stage IV 24 (32.4%). 25 patients were relapsed and 5-year disease-free survival (DFS) rate was 61.4%. High expression of HIF-1α was related to the advanced T stage (p = 0.029), more invasive tumor (p = 0.003) and tumor recurrence (p = 0.037). High expression of PDK-1 was related to the advanced N stage (p = 0.026) and high expression of LDH-5 was related to the lymphatics invasion (p = 0.028), advanced N stage (p = 0.020) and more invasive tumor (p = 0.015). The high expression of HIF-1α, PDK-1, and LDH-5 showed a significant correlation to each other. 16 (21.6%) patients were highly expressed all three markers. High expression of all three markers correlated with more invasive tumor (p = 0.004) and tumor recurrence (p = 0.017). In survival analysis, high expression of HIF-1α and LDH-5 associated with shorter DFS in log rank test (p = 0.002 and p = 0.016, respectively). High expression of all three markers was also associated with shorter DFS (p = 0.002). In multivariate Cox regression analysis, high expression of all three markers was strong independent prognostic factor for DFS (p = 0.021). Conclusions: The oral SCC which glycolytic metabolism was changed showed a more invasive and aggressive phenotype. Taken together, biomarkers related tumor metabolism may be independent prognostic markers for the DFS in the patients with oral SCC.

No significant financial relationships to disclose.

Distribution of phosphorus compounds in corn processing

Distillers dried grains with solubles (DDGS) and corn gluten feed (CGF) are major coproducts of ethanol production from corn dry grind and wet milling facilities, respectively. These coproducts contain important nutrients, nevertheless, high levels of phosphorus (P). About 50-80% of the P in these products is in an organically bound form known as phytate. The phytate P in these products cannot be digested by nonruminant animals. Consequently, large quantities of phytate are deposited into the soil with the animal wastes which potentially could cause P pollution in soil and underground water resources. As regulations on the concentration of P material in ethanol production coproducts become more restrictive, measures need to be taken for effective extraction of phytate P from the coproducts to make these processes more environmentally compatible. Proper marketing of coproducts is critical to the overall economy of ethanol production facilities. In this study, distribution of P compounds in different streams of dry grind and wet milling operations was determined. In the dry grind process, the highest P concentration was found to be in the condensed distillers solubles (CDS) at about 1.34 wt.% (db). About 59% of P in this stream was in phosphates form. The highest concentration of P in the wet milling process was found in the light steep water at about 3.4 wt.% (db). In this stream, about 22% of P was attributed to phosphates.

A novel chimeric promoter that is highly responsive to hypoxia and metals

To develop a potent hypoxia-inducible promoter, we evaluated the usefulness of chimeric combinations of the (Egr-1)-binding site (EBS) from the Egr-1 gene, the metal-response element (MRE) from the metallothionein gene, and the hypoxia-response element (HRE) from the phosphoglycerate kinase 1 gene. In transient transfection assays, combining three copies of HRE (3 x HRE) with either EBS or MRE significantly increased hypoxia responsiveness. When a three-enhancer combination was tested, the EBS-MRE-3 x HRE (E-M-H) gave a hypoxia induction ratio of 69. The expression induced from E-M-H-pGL3 was 2.4-fold higher than that induced from H-pGL3 and even surpassed the expression from a human cytomegalovirus promoter-driven vector. The high inducibility of E-M-H was confirmed by validation studies in different cells and by expressing other cDNAs. Gel shift assays together with functional overexpression studies suggested that increased levels of hypoxia-inducible factor 1alpha, metal transcription factor-1 and Egr-1 may be associated with the high inducibility of the E-M-H chimeric promoter. E-M-H was also induced by hypoxia mimetics such as Co2+ and deferoxamine (DFX) and by hydrogen peroxide. Gene expression from the E-M-H was reversible as shown by the reduced expression of the transgene upon removal of inducers such as hypoxia and DFX. In vivo evaluation of the E-M-H in ischemic muscle revealed that erythropoietin secretion and luciferase and LacZ expression were significantly higher in the E-M-H group than in a control or H group. With its high induction capacity and versatile means of modulation, this novel chimeric promoter should find wide application in the treatment of ischemic diseases and cancer.

Blockade of p38 mitogen-activated protein kinase pathway inhibits interleukin-6 release and expression in primary neonatal cardiomyocytes

The induction of interleukin-6 (IL-6) using combined proinflammatory agents (LPS/IFN-gamma or TNF-alpha/IFN-gamma) was studied in relation to p38 mitogen-activated protein kinase (MAPK) and NF-kappaB transcriptional factor in primary neonatal cardiomyocytes. When added to cultures of cardiomyocytes, the combined agents (LPS/IFN-gamma or TNF-alpha/IFN-gamma) had stimulatory effect on the production of IL-6 and the elevation was significantly reduced by SB203580, a specific p38 MAPK inhibitor. SB203580 inhibited protein production and gene expression of IL-6 in a concentration-dependent manner. In this study, IFN-gamma enhancement of TNF-alpha-induced NF-kappaB binding affinity as well as p38 MAP kinase activation was observed. However, a specific inhibitor of p38 MAPK, SB203580, had no effect on TNF-alpha/IFN-gamma or LPS/IFN-gamma-induced NF-kappaB activation. This study strongly suggests that these pathways about TNF-alpha/IFN-gamma or LPS/IFN-gamma-activated IL-6 release can be primarily dissociated in primary neonatal cardiomyocytes.

NADPH oxidase of neutrophils elevates o,o'-dityrosine cross-links in proteins and urine during inflammation

Reactive intermediates generated by phagocytic white blood cells are of central importance in destroying microorganisms, but they may also damage normal tissue at sites of inflammation. To investigate the potential role of such oxidants in tissue injury, we used gas chromatography/mass spectrometry to quantify levels of o,o'-dityrosine in mouse peritoneal neutrophils and urine. In wild-type animals, neutrophils markedly increased their content of protein-bound dityrosine when they were activated in vivo. This increase failed to occur in mice that were deficient in the phagocyte NADPH oxidase. Levels of o,o'-dityrosine in urine mirrored those in neutrophil proteins. When o,o'-[(14)C]dityrosine was injected intravenously into mice, the radiolabel was not metabolized or incorporated into tissue proteins: instead, it was recovered in urine with near-quantitative yield. Patients with sepsis markedly increased their output of o,o'-dityrosine into urine, suggesting that systemic inflammation also may be a potent source of oxidative stress in humans. These observations demonstrate that activated neutrophils produce o,o'-dityrosine cross-links in tissue proteins, which may subsequently be degraded into free amino acids and excreted into urine. Our results indicate that mouse phagocytes use oxidants produced by the NADPH oxidase to create o,o'-dityrosine cross-links in vivo and raise the possibility that reactive intermediates produced by this pathway promote inflammatory tissue damage in humans.

Neutrophils employ the myeloperoxidase system to generate antimicrobial brominating and chlorinating oxidants during sepsis

The myeloperoxidase system of neutrophils uses hydrogen peroxide and chloride to generate hypochlorous acid, a potent bactericidal oxidant in vitro. In a mouse model of polymicrobial sepsis, we observed that mice deficient in myeloperoxidase were more likely than wild-type mice to die from infection. Mass spectrometric analysis of peritoneal inflammatory fluid from septic wild-type mice detected elevated concentrations of 3-chlorotyrosine, a characteristic end product of the myeloperoxidase system. Levels of 3-chlorotyrosine did not rise in the septic myeloperoxidase-deficient mice. Thus, myeloperoxidase seems to protect against sepsis in vivo by producing halogenating species. Surprisingly, levels of 3-bromotyrosine also were elevated in peritoneal fluid from septic wild-type mice and were markedly reduced in peritoneal fluid from septic myeloperoxidase-deficient mice. Furthermore, physiologic concentrations of bromide modulated the bactericidal effects of myeloperoxidase in vitro. It seems, therefore, that myeloperoxidase can use bromide as well as chloride to produce oxidants in vivo, even though the extracellular concentration of bromide is at least 1,000-fold lower than that of chloride. Thus, myeloperoxidase plays an important role in host defense against bacterial pathogens, and bromide might be a previously unsuspected component of this system.

Intracardiac echocardiographic guidance and monitoring during percutaneous endomyocardial gene injection in porcine heart

In an effort to develop a guiding and monitoring tool for transmyocardial gene transfer, we have evaluated the feasibility of intracardiac echocardiography (ICE) to guide percutaneous endomyocardial gene transfer (PEGT), and monitor complications, in a pig model. ICE (5.5-10 MHz), complemented by fluoroscopy, was utilized to guide a needle injection into the heart in 19 normal pigs. Using this system, we injected Evans blue dye into eight pigs (group I), a mixture of pCK-CAT plasmid and India ink into seven pigs (group II), and pCK-LacZ plasmid into four pigs (group III). In all pigs, ICE contributed to the injection procedure by guiding the catheter to anatomically distinct sites, and by assisting stabilization of the catheter-endocardial contact. ICE predicted the injection sites correctly in 56 of 64 sites (87.5%) in group I, and in 42 of 42 sites (100%) in group II. Leakage of injectate into the left ventricular cavity could be detected by the microbubbles generated. The sites of injections appeared as foci of bright myocardial echodensity, which persisted until the end of the procedure. The procedures were not associated with significant morbidity or mortality. The expression of the chloramphenicol acetyltransferase (CAT) gene was identified in 40 sites from 42 injections (95.2%) in group II. In group III, histology showed positive beta-galactosidase staining of myocytes limited around the needle track with low transfection efficiency (<1%). These results suggest that real-time ICE monitoring proves safe and useful during PEGT for guiding needle injection, monitoring leakage, ensuring delivery of injectate into the myocardium, and instantly diagnosing cardiac complications, resulting in successful gene transfer.