Motion-Corrected versus Conventional Diffusion-Weighted Magnetic Resonance Imaging of the Liver Using Non-Rigid Registration

It is challenging to overcome motion artifacts in diffusion-weighted imaging (DWI) of the abdomen. This study aimed to evaluate the image quality of motion-corrected DWI of the liver using non-rigid registration in comparison with conventional DWI (c-DWI) in patients with liver diseases. Eighty-nine patients who underwent 3-T magnetic resonance imaging (MRI) of the liver were retrospectively included. DWI was performed using c-DWI and non-rigid motion-corrected (moco) DWI was performed in addition to c-DWI. The image quality and conspicuity of hepatic focal lesions were scored using a five-point scale by two radiologists and compared between the two DWI image sets. The apparent diffusion coefficient (ADC) was measured in three regions of the liver parenchyma and in hepatic focal lesions, and compared between the two DWI image sets. Moco-DWI achieved higher scores in image quality compared to c-DWI in terms of liver edge sharpness and hepatic vessel margin delineation. The conspicuity scores of hepatic focal lesions were higher in moco-DWI. The standard deviation values of ADC of the liver parenchyma were lower in the moco-DWI than in the c-DWI. Moco-DWI using non-rigid registration showed improved overall image quality and provided more reliable ADC measurement, with an equivalent scan time, compared with c-DWI.

All-cause mortality, cardiovascular mortality, and incidence of cardiovascular disease according to a screening program of cardiovascular risk in South Korea among young adults: a nationwide cohort study

OBJECTIVES

We aimed to determine whether there are any differences in all-cause and cause-specific mortality with cardiovascular disease (CVD) risk between health screening attenders and non-attenders among young adults.

STUDY DESIGN

We performed a retrospective cohort study using claim data from the Korean National Health Insurance Service database.

METHODS

Individuals aged 20-39 years who had received health screening at least once between 2002 and 2005 were classified as attenders, and the others were classified as non-attenders. After propensity score matching according to attendance of health screening, 2,060,409 attenders and 2,060,409 non-attenders were included. We estimated adjusted hazard ratios (HRs) and 95% confidence interval (CI) for all-cause mortality, cause-specific mortality, and hospitalization of CVD from 2006 to 2015.

RESULTS

Survival from all-cause mortality was greater among attenders than among non-attenders (log rank P < 0.001). Similarly, death from CVD (log rank P = 0.007) and CVD events (log rank P < 0.001) were less likely among attenders. The risk for all-cause mortality in attenders was significantly lower than that in non-attenders (HR = 0.83, 95% CI = 0.81 to 0.84). The risk for CVD mortality (HR = 0.80, 95% CI = 0.73 to 0.87) and hospitalization of CVD (HR = 0.92, 95% CI = 0.91 to 0.94) were lower in attenders. In stratified analyses, the risk for all-cause and cause-specific mortalities was lower among attenders regardless of insurance type.

CONCLUSIONS

Among young adults, the risk for all-cause mortality, CVD mortality, and hospitalization of CVD were lower for those who underwent health screenings. Future studies that evaluate the cost-effectiveness of health screening with additional consideration of psychosocial aspects are needed.

The association between muscle mass deficits and arterial stiffness in middle-aged men

BACKGROUND AND AIMS

Early diagnosis of arteriosclerosis is fundamental for the prevention of cardiovascular morbidity and mortality. The current study was performed to identify major predictors of arteriosclerosis and to assess the association between arterial stiffness as measured by cardio-ankle vascular index (CAVI) and muscle mass deficit (MMD) estimated by bioelectrical impedance analysis (BIA) in middle-aged men.

METHODS AND RESULTS

Data were gathered from 3356 middle-aged men who visited a health promotion center. CAVI was measured as an index of arterial stiffness. Body composition analysis was performed using BIA. MMD was positively associated with CAVI in the regression model. The odds ratios for high-CAVI (≥9.0) rose with MMD grade in a dose-dependent manner after adjusting for age, lifestyle factors and current medication use. The estimated mean CAVI rose as MMD grade increased (P for trend >0.001).

CONCLUSIONS

MMD estimated from BIA was positively associated with arterial stiffness in middle-aged men. These findings show a close interaction between low muscle mass and cardiovascular risk.

Acute toxicity of organic antifouling biocides to phytoplankton Nitzschia pungens and zooplankton Artemia larvae

The toxicity of the antifouling biocides Irgarol 1051, Diuron, Chlorothalonil, Dichlofluanid, Sea-nine 211, Copper pyrithione, Zinc pyrithione, Ziram and Zineb were evaluated on Nitzschia pungens and Artemia larvae. Results showed that EC₅₀ for Irgarol 1051 was 0.586μgl^-1 was the strongest effect on N. pungens following by Copper pyrithione (4.908μgl^-1), Ziram (5.421μgl^-1), Zinc pyrithione (5.513μgl^-1), Diuron (6.640μgl^-1), Zineb (232.249μgl^-1), Sea-nine 211(267.368μgl^-1), Chlorothalonil (360.963μgl^-1) and Dichlofluanid (377.010μgl^-1) in 96h. In Artemia larvae, the biocides were evaluated the LC₅₀ for larval survivals at 48h. Sea-nine 211 and Copper pyrithione were 0.318 and 0.319mgl^-1. Chlorothalonil, Zinc pyrithione and Ziram were 2.683, 3.147 and 4.778mgl^-1. Irgarol 1051, Diuron, Zineb and Dichlofluanid were 9.734, 30.573, 41.170 and 154.944mgl^-1. These results provide baseline data concerning the toxicity of antifouling biocides against marine environment.

Surveillance of the Middle East respiratory syndrome (MERS) coronavirus (CoV) infection in healthcare workers after contact with confirmed MERS patients: incidence and risk factors of MERS-CoV seropositivity

Given the mode of transmission of Middle East respiratory syndrome (MERS), healthcare workers (HCWs) in contact with MERS patients are expected to be at risk of MERS infections. We evaluated the prevalence of MERS coronavirus (CoV) immunoglobulin (Ig) G in HCWs exposed to MERS patients and calculated the incidence of MERS-affected cases in HCWs. We enrolled HCWs from hospitals where confirmed MERS patients had visited. Serum was collected 4 to 6 weeks after the last contact with a confirmed MERS patient. We performed an enzyme-linked immunosorbent assay (ELISA) to screen for the presence of MERS-CoV IgG and an indirect immunofluorescence test (IIFT) to confirm MERS-CoV IgG. We used a questionnaire to collect information regarding the exposure. We calculated the incidence of MERS-affected cases by dividing the sum of PCR-confirmed and serology-confirmed cases by the number of exposed HCWs in participating hospitals. In total, 1169 HCWs in 31 hospitals had contact with 114 MERS patients, and among the HCWs, 15 were PCR-confirmed MERS cases in study hospitals. Serologic analysis was performed for 737 participants. ELISA was positive in five participants and borderline for seven. IIFT was positive for two (0.3%) of these 12 participants. Among the participants who did not use appropriate personal protective equipment (PPE), seropositivity was 0.7% (2/294) compared to 0% (0/443) in cases with appropriate PPE use. The incidence of MERS infection in HCWs was 1.5% (17/1169). The seroprevalence of MERS-CoV IgG among HCWs was higher among participants who did not use appropriate PPE.

Apolipoprotein B: novel indicator of elevated intraocular pressure

PURPOSE

Many studies have reported associations between elevated intraocular pressure (IOP) and systemic health parameters, which suggest a common mechanism links IOP elevation and various related cardiometabolic risk factors. Furthermore, according to a recent study, serum apolipoprotein B (APO B) level is a predictor of coronary artery disease. This study was undertaken to analyse the relationship between serum apolipoprotein levels and IOP.

METHODS

Healthy people (28,852) who attended a community hospital for a health checkup between January 2011 and December 2013 were enroled in the study. We measured age, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), serum levels of total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and apolipoprotein A1 (APO A1) and APO B, APO B/APO A1 ratios, and IOP.

RESULTS

Univariate regression analysis showed IOP was positively correlated with BMI, SBP, DBP, TC, LDL-C, TG, APO B, and APO B/APO A1 (P<0.001), and negatively correlated with HDL-C (P<0.001). On the other hand, multivariate regression analysis adjusted for age, BMI, SBP, and DBP, revealed IOP was positive correlated with TC, TG, LDL-C, APO B, and APO B/APO A1, and negatively correlated with HDL-C (all <0.05).

CONCLUSIONS

Among the various lipid profiles investigated, APO B was found to be most strongly correlated with IOP, regardless of sex. Additional studies are required to confirm the validity of apolipoprotein level as an index for predicting IOP.

Predictors of uropathogens other than Escherichia coli in patients with community-onset acute pyelonephritis

AIM

A constant reduction in the incidence of community-onset acute pyelonephritis (CO-APN) caused by Escherichia coli has been shown with a parallel increase incidence caused by other organisms. Therefore, we evaluated the risk factors and outcome of non-E. coli as uropathogens in patients with community-onset APN.

METHODS

As a part of a nationwide multicentre surveillance study conducted in Korea, a total of 416 patients with CO-APN were collected with their epidemiological, antibiotic treatment and outcome data.

RESULTS

The risk factors and outcomes of non-E. coli as uropathogens were evaluated in a total of 416 patients with culture-confirmed CO-APN. Non-E. coli caused 127 cases (30.5%) of CO-APN. CO-APN caused by non-E. coli resulted in higher inappropriate empirical therapy (38.6% vs. 20.1%, p < 0.001), longer hospital stay (12.6 days vs. 6.7 days, p = 0.005) and higher 30-day mortality (9.4% vs. 3.8% p = 0.020) compared with CO-APN caused by E. coli. Multivariate analyses showed that male gender (OR, 3.48; CI, 2.13-5.67; p < 0.001), underlying haematological disease (OR, 5.32; CI, 1.17-24.254; p = 0.031), underlying benign prostate hyperplasia (OR, 2.61; CI, 1.02-6.74; p = 0.046), chronic indwelling urethral catheter (OR, 6.34; CI, 1.26-31.84; p = 0.025) and admission history in the previous 6 months (OR, 2.12; CI, 1.23-3.58; p = 0.005) were predictors for CO-APN caused by a non-E. coli isolate.

CONCLUSIONS

Community-onset APN caused by non-E. coli represents a distinct subset of urinary tract infections with worse outcomes. The defined risk factors related with non-E. coli should be taken into consideration when empirical antibiotic therapy is prescribed in patients with community-onset APN.

Isolation and characterization of a lytic Myoviridae bacteriophage PAS-1 with broad infectivity in Aeromonas salmonicida

To search for candidate control agents against Aeromonas salmonicida subsp. salmonicida infections in aquaculture, one bacteriophage (phage), designated as PAS-1, was isolated from the sediment samples of the rainbow trout (Oncorhynchus mykiss) culture farm in Korea. The PAS-1 was morphologically classified as Myoviridae and possessed approximately 48 kb of double-strand genomic DNA. The phage showed broad host ranges to other subspecies of A. salmonicida as well as A. salmonicida subsp. salmonicida including antibiotic-resistant strains. Its latent period and burst size were estimated to be approximately 40 min and 116.7 PFU/cell, respectively. Furthermore, genomic and structural proteomic analysis of PAS-1 revealed that the phage was closely related to other Myoviridae phages infecting enterobacteria or Aeromonas species. The bacteriolytic activity of phage PAS-1 was evaluated using three subspecies of A. salmonicida strain at different doses of multiplicity of infection, and the results proved to be efficient for the reduction of bacterial growth. Based on these results, PAS-1 could be considered as a novel Aeromonas phage and might have potentiality to reduce the impacts of A. salmonicida infections in aquaculture.

Complete genome sequence of a newly isolated lytic bacteriophage, EFAP-1 of Enterococcus faecalis, and antibacterial activity of its endolysin EFAL-1

AIMS

In this work, we aimed to identify an effective treatment of infections caused by Enterococcus spp. strains resistant to conventional antibiotics.

METHODS AND RESULTS

We report the isolation and characterization of a new lytic bacteriophage, designated bacteriophage EFAP-1, that is capable of lysing Enterococcus faecalis bacteria that exhibit resistance to multiple antibiotics. EFAP-1 has low sequence similarity to all known bacteriophages. Transmission electron microscopy confirmed that EFAP-1 belongs to the Siphoviridae family. A putative lytic protein of EFAP-1, endolysin EFAL-1, is encoded in ORF 2 and was expressed in Escherichia coli. Recombinant EFAL-1 had broad-spectrum lytic activity against several Gram-positive pathogens, including Ent. faecalis and Enterococcus faecium.

CONCLUSIONS

The complete genome sequence of the newly isolated enterococcal lytic phage was analysed, and it was demonstrated that its recombinant endolysin had broad lytic activity against various Gram-positive pathogens.

SIGNIFICANCE AND IMPACT OF THE STUDY

Bacteriophage EFAP-1 and its lytic protein, EFAL-1, can be utilized as potent antimicrobial agents against Enterococcus spp. strains resistant to conventional antibiotics in hospital infections and also as environmental disinfectants to control disease-causing Enterococcus spp. in dairy farms.

Post-growth annealing effects of Mg doped GaAs epitaxial layers on microstructural and optical properties

The post-growth thermal annealing effects of Mg doped GaAs epitaxial layers on the microstructural and optical properties grown by molecular beam epitaxy (MBE) have been investigated. The properties of Mg doped GaAs are estimated after the process of rapid thermal annealing (RTA) in the temperature range of 600 approximately 750 degrees C. The photoluminescence (PL) peak position of as-grown sample blueshifted from 1.473 to 1.485 eV as well as the pronounced enhancement in PL intensity by annealing at 600 degrees C. In the sample grown at the temperature of T(s) = 475 degrees C, the full-width at half maximum (FWHM) of double crystal X-ray diffraction (DCXRD) decreased form 27 to 8 arcsec with increasing of annealing temperature (600 approximately 700 degrees C). The crystalline quality variation of Mg doped GaAs layers by RTA is greatly dependent upon the doping level.

Cryopreservation of Taxus chinensis suspension cell cultures

A simple cryopreservation method for suspension cells of Taxus chinensis was established. In this procedure 7 days old suspension cells were used without any pre-culture treatment. At first, cells were incubated in cryoprotectant solution (0.5M DMSO and 0.5M glycerol) on ice for 30 min and then frozen at a cooling rate of 1 degree C/min to -40 degrees C prior to immersion in liquid nitrogen. The average viability of frozen-thawed cells was between 30 to 40%. The recovery of cryopreserved cells in liquid nitrogen for 1 month was accomplished. After rapid thawing, cells were transferred to solid medium and cultivated for 4-6 weeks. The treatment of trehalose as a cryoprotectant enhanced re-growth of frozen-thawed cells. The stable maintenance of paclitaxel biosynthetic ability in cryopreserved cells was confirmed by comparing with that of regularly sub-cultured suspension cells.

Role of jasmonic acid in biotransformation of (--)-isopiperitenone in suspension cell culture of Mentha piperita

The role of jasmonic acid was studied in biotransformation of (--)-isopiperitenone to (--)-7-hydroxyisopiperitenone using alpha suspension cells were treated with (--)-isopiperitenone, mRNA of a cytochrome P450 was induced in a similar time-course pattern as the biotransformation shown in a previous study (Park et al., 1997). The induction of P450 mRNA and the biotransformation of (--)-isopiperitenone were increased by methyl jasmonate, but decreased by salicylhydroxamic acid, and inhibitor of jasmonic acid synthesis. These results suggest that the biotransformation involves the induction of P450 which is mediated by jasmonic acid as a signaling molecule.