Identification of distinct subgroups in moderately severe rheumatic mitral stenosis using data-driven phenotyping of longitudinal hemodynamic progression

Background

Rheumatic mitral stenosis (MS) is a significant cause of valvular heart disease. Pulmonary artery systolic pressure (PASP) reflects the hemodynamic consequences of MS and is used to determine treatment strategies. However, PASP progression and expected outcomes in patients with moderately severe MS remain unclear.

Purpose

We aimed to examine the impact of progression rate of PASP in moderately severe MS.

Methods

A cohort of 866 consecutive patients with moderately severe rheumatic MS (1.0 cm2.

Results

Data-driven phenotyping identified two distinct trajectories based on PASP progression: a rapid progression group (N=38, 8.7%) and a slow progression group (N=398, 91.3%). Patients in the rapid progression group were older and had more comorbidities than patients in the slow progression group, including diabetes, and atrial fibrillation (all P<0.05). The initial mean diastolic pressure gradient and PASP were higher in the rapid progression group than in the slow progression group (6.2±2.4 mmHg vs. 5.1±2.0 mmHg, P=0.001, and 42.3±13.3 mmHg vs. 33.0±9.2 mmHg, P<0.001, respectively). During a mean follow-up of 7.0±3.0 years, the event-free survival rate was significantly lower in the rapid progression group than in the slow progression group (log-rank P<0.001). Rapid PASP progression was a significant risk factor for composite outcomes even after adjusting for comorbidities (hazard ratio: 3.08, 95% confidence interval (CI): 1.68–5.64, P<0.001). Multivariate regression analysis revealed that PASP>40 mmHg was independently associated with the probability of rapid progression group allocation (odds ratio: 4.95, 95% CI: 2.08–11.99, P<0.001).

Conclusions

Two groups with distinct patterns of PASP progression were identified. Rapid PASP progression was associated with a significantly higher risk of the composite outcomes. The main independent echocardiographic predictor for rapid progression group allocation was initial PASP>40 mmHg.

Funding Acknowledgement

Type of funding sources: Private hospital(s). Main funding source(s): This study was supported by a Severance Hospital Research fund for Clinical excellence (SHRC) (C-2020-0041) and a faculty research grant of Yonsei University College of Medicine (6-2020-0156).

Prognostic value of liver stiffness in patients with tricuspid regurgitation

Background

It has been known that liver stiffness (LS) assessed by transient elastography is associated with right heart dysfunction and the severity of the tricuspid regurgitation. However, the predictive value of LS for adverse outcome in patients with tricuspid regurgitation (TR) is uncertain.

Objectives

The aim of this study was to identify the prognostic value of LS in patients with moderate or greater degree of TR.

Methods

A total of 257 patients with moderate or severe TR who underwent both echocardiography and liver transient elastography were retrospectively analysed. Patients who have congenital heart disease or chronic liver disease including, viral hepatitis, alcoholic liver disease, autoimmune hepatitis, hepatocellular carcinoma were excluded. Severe LS was defined as elevated kilopascal (kPa) ≥11 (High kPa). Primary outcome was defined as the composite of all-cause death and unplanned admission for heart failure.

Results

One hundred forty-one patients had moderate TR and 116 patients had severe TR. One hundred twenty-eight (50%) patients had severe liver stiffness. During a follow-up period (median 637 days, IQR 1317), 116 (45.1%) primary outcomes occurred. In Kaplan-Meier analysis, patients who had severe TR with high kPa showed the worst outcome. Moreover, patients who had high kPa were associated with worse clinical outcome both moderate TR group and severe TR group than patients with low kPa. In multivariate Cox regression analysis, severe liver stiffness was independently associated with primary outcomes (HR=1.66, 95% CI: 1.28–2.16), p<0.001).

Conclusions

LS is independently associated with adverse clinical outcomes in both patients with moderate and severe TR. The degree of liver fibrosis measured by transient elastography may be a useful marker of cardiac hepatopathy related to TR, and this may contribute to predict the prognosis of TR.

Funding Acknowledgement

Type of funding sources: None.

Development and validation of interpretable machine learning models for inpatient fall events and electronic medical record integration

OBJECTIVE

Falls are one of the most frequently occurring adverse events among hospitalized patients. The Morse Fall Scale, which has been widely used for fall risk assessment, has the two limitations of low specificity and difficulty in practical implementation. The aim of this study was to develop and validate an interpretable machine learning model for prediction of falls to be integrated in an electronic medical record (EMR) system.

METHODS

This was a retrospective study involving a tertiary teaching hospital in Seoul, Korea. Based on the literature, 83 known predictors were grouped into seven categories. Interpretable fall event prediction models were developed using multiple machine learning models including gradient boosting and Shapley values.

RESULTS

Overall, 191,778 cases with 272 fall events (0.1%) were included in the analysis. With the validation cohort of 2020, the area under the receiver operating curve (AUROC) of the gradient boosting model was 0.817 (95% confidence interval [CI], 0.720-0.904), better performance than random forest (AUROC, 0.801; 95% CI, 0.708-0.890), logistic regression (AUROC, 0.802; 95% CI, 0.721-0.878), artificial neural net (AUROC, 0.736; 95% CI, 0.650-0.821), and conventional Morse fall score (AUROC, 0.652; 95% CI, 0.570-0.715). The model's interpretability was enhanced at both the population and patient levels. The algorithm was later integrated into the current EMR system.

CONCLUSION

We developed an interpretable machine learning prediction model for inpatient fall events using EMR integration formats.

First report of pepino mosaic virus infecting tomato in South Korea

Pepino mosaic virus (PepMV), a member of the genus Potexvirus in the family Alphaflexiviridae, has been responsible for economic losses in tomato across Africa, Asia, Europe, and the Americas over the last two decades, but has not previously been reported in South Korea. In December 2020, virus-like symptoms (foliar interveinal chlorosis and unevenly discolored fruits) were observed on ~5% of tomato (Solanum lycopersicum) plants growing in a greenhouse in Jeolla province, South Korea. To identify the causal virus, total RNA from a leaf sample of the symptomatic tomato was extracted using an RNeasy Plant Mini Kit (Qiagen, Germany) and analyzed by high-throughput sequencing. Ribosomal RNA was removed and a cDNA library was prepared using an Illumina TruSeq Stranded Total RNA LT Sample Prep Kit (Plants) and sequenced on an Illumina NovaSeq 6000 system (Macrogen, Korea), yielding 151 nt paired end reads. De novo assembly of the 74,417,192 reads was performed using Trinity software (r20140717) while the 308,940 initially assembled contigs were screened against the NCBI viral genome database using BLASTN. Two contigs of 6,419 and 6,391 bp (GenBank LC656469, JKT1; and LC656470, JKT2) shared 94.81% and 98.34% nucleotide (nt) identities with isolates of the CH2 group (MK133092 and MF422613) and US1 group (FJ940225), respectively. No contigs representing other plant viruses were identified. A phylogenetic tree of the genomes of 44 isolates encompassing different PepMV strains (Abrahamian et al., 2020) also placed JKT1 in the CH2 clade, and JKT2 in the US1 clade. Leaf samples from 24 randomly selected plants from the same greenhouse were tested by reverse transcription-polymerase chain reaction (RT-PCR) with PepMV-specific primers, Pep3/Pep4 and PepCP-D/PepCP-R (Souiri et al., 2019), yielding products of the expected sizes (625 bp for Pep3/Pep4 and 848 bp for PepCP-D/PepCP-R) from all samples. Amplicons were cloned into the pGEM-T Easy Vector (Promega, USA); two clones for each amplicon were bidirectionally sequenced (BIONEER, Korea) and deposited in GenBank. The 848 bp amplicon (accession no. LC637517) showed 99.65% nt identity to the JKT1 genome (LC656469) and 94.69% identity to a CH2 isolate (JN835466); the 625 bp amplicon (LC637518) had 99.36% nt identity to the JKT2 genome (LC656470) and 97.28% identity to a US1 isolate (FJ940225). Primers specific to the coat protein gene of each isolate (JKT1-F/JKT1-R, CGCTTGCTGGTGCTGTTCAAG/ACGTCTAGACAAAGCAGGGTT, 934 bp; JKT2-F/JKT2-R, CACTAAATGCAGCAGTTTCTG/AGTTTCATTAGCAGCCAGTC, 830 bp) also yielded the expected amplicons from all 24 samples, indicating mixed infections of PepMV strains CH2 and US1. The PCR products from three randomly-selected samples shared 79.93-80.17% nt identity between (JKT1/JKT2) two JKT1-derived sequences (LC683791 and LC683792) and two JKT2-derived sequences (LC683793 and LC683794), further supporting the presence of mixed infections in the samples. To our knowledge, this is the first report of PepMV infecting tomato in South Korea. The virus is carried on tomato seeds (Córdoba-Sellés et al., 2007; Hanssen et al., 2010), and efficiently transmitted by mechanical means leading to rapid spread in tomato crops, and the severe strain CH2 may be a serious threat to tomato production in South Korea. It is important to concentrate on the phytosanitary control for both importation and exportation to manage and prevent further spread of contaminated seeds or infected transplants.

First report of zucchini yellow mosaic virus infecting bitter melon (Momordica charantia) in South Korea

Bitter melon (Momordica charantia L., family Cucurbitaceae) is used in traditional medicine for diabetes, cancer, and inflammation-associated diseases due to bioactive compounds in Asia and tropical Africa (Bortolotti et al. 2019). In July 2021, approximately 10% of bitter melon plants in the field showed symptoms such as mosaic, yellowing, and leaf deformation on the leaves, in Samchcuk, South Korea. Cucumber and zucchini plants growing in the same field exhibited symptoms like those of bitter melon plants (Ali et al. 2012). To investigate the causative virus, leaf dip preparations from three symptomatic bitter melon leaf samples with symptoms were analyzed by transmission electron microscopy (TEM). Potyvirus-like particles (approximately 680-730 nm in length and 11-13 nm in diameter) were observed in all samples. To further identify the causal viral pathogens, leaf extracts from five symptomatic bitter melon plants were tested by DAS-ELISA using specific antibodies (Agdia, Elkhart, IN, USA) against cucumber mosaic virus, zucchini yellow mosaic virus (ZYMV), watermelon mosaic virus, and papaya ring spot virus. Positive controls from commercial kits and negative controls from healthy bitter melon plants were included in ELISA assay. The serological assay revealed that all five symptomatic samples positively reacted with the antiserum against ZYMV, but not for other viruses. Total RNA extracted from the five ELISA-positive samples and two healthy bitter melon plants (as negative controls), using Clear-S Total RNA extraction kit (InVirusTech Co., Gwangju, Korea), was tested by RT-PCR with ZYMV-specific primers as previously described (Cho et al. 2011). All amplicons of the expected size (~822 bp) were individually cloned into the pGEM-T Easy Vector (Promega, Madison, WI), and sequenced in both orientations. Thereafter, all the sequenced clones shared 100% nucleotide identity. The sequence of ZYMV-MC1 isolated from bitter melon was deposited in the GenBank (accession no. LC652434). Pairwise comparison of the nucleotide sequence with that of ZYMV isolates in the GenBank revealed 99% sequence identity with ZYMV-chk (MG020559) from Korea, 98% with ZYMV-14-HY-SCS (KU743321) from China, 97% with ZYMV-Y21 (MW345249) from Turkey, 96% with ZYMV-AUIKTPK (KR261951) from Pakstan. Leaf saps from the ZYMV-positive bitter melon samples, prepared in 10 mM phosphate buffer (pH 7.0), were mechanically inoculated in five young, healthy bitter melon plants to fulfil Koch's postulates. ZYMV-MC1 isolate caused mosaic and leaf deformation on bitter melon plants 10 days post-inoculation. The presence of ZYMV in the symptomatic leaves was confirmed by RT-PCR using the mentioned above primers mentioned above followed by nucleotide sequencing of the amplicons. Several cotton aphids (Aphis gossypii) were observed in the bitter melon field, which indicated that they might transmit the virus from ZYMV-infected cucumber or zucchini plants. ZYMV is one of the economically important viruses of cucurbits worldwide and has been recently reported from various crops as natural hosts, including Chayote (Yoon et al. 2018) and balloon flowers (Kim et al. 2021). To the best of our knowledge, this is the first report of ZYMV naturally infecting bitter melon in South Korea. Further large -scale surveys are required to determine its incidence, yield losses, and management in bitter melon in Korea.

Differential characteristics associated with progression of mitral and aortic regurgitation in patients undergoing kidney transplantation

Background

Heart valve regurgitation is common in patients with end-stage renal disease (ESRD). However, there are no data on the fate of mitral regurgitation (MR) and aortic regurgitation (AR) after kidney transplantation (KT). In this study, we sought to investigate regression or progression rates of MR and AR after KT in patients with ESRD. Moreover, we aimed to explore clinical and echocardiographic factors associated with the progression of MR and AR in patients undergoing KT.

Methods

Among 1,734 patients who underwent KT from 2005 to 2018 at a single tertiary hospital, 674 patients (407 men; mean 48±12 years) who underwent both pre- and post-KT echocardiography were analyzed comprehensively. Pre-KT echocardiography was performed within three months of KT, and post-KT echocardiography was done between 6 months and 24 months after KT. Severities of MR and AR were graded as no/trivial, mild, moderate, and severe according to the current guidelines. Regression was defined if the severity decreased by one or more grades, while progression was defined if the severity increased by one or more grades.

Results

Figure 1 shows the regression or progression of MR and AR after KT. 78 (11%) patients showed MR regression, but 41 (6%) experienced MR progression. 13 (2%) revealed AR regression, while 23 (4%) presented AR progression. In patients with MR progression, there were more cases of receiving a second KT, having mitral annular calcification, and showing lesser reduction of left atrial volume after KT. Patients with AR progression showed a longer hemodialysis duration, persistent hypertension after KT, and aortic root dilatation. Factors related to the progression of MR and AR showed statistically meaningful predictive values in a stepwise manner (Figure 2)

Conclusions

In patients undergoing KT, MR and AR may progress in patients with certain distinct characteristics. Different clinical and echocardiographic characteristics before KT, and reduction of hemodynamic loads after KT determine the progression of MR and AR. Further echocardiographic surveillances after KT are needed in patients with clinical and echocardiographic factors for progression of valve regurgitation.

Funding Acknowledgement

Type of funding sources: None.

Factors determining mitral valve dysfunction in patients who underwent surgical mitral valve replacement with bio-prosthetic valves

Background

There is increasing Interest in bio-prosthetic MVD as recent advances in transcatheter MV interventions, but there is limited data.

Objectives

The aim of this study was to identify the factors determining mitral valve (MV) dysfunction (MVD) in patients who underwent MV replacement with bio-prosthetic valves. Also, we sought to investigate clinical outcomes in patients with bio-prosthetic MVD.

Methods

A total of 233 patients underwent surgical bio-prosthetic MV replacement between June 1996 and May 2015. Finally, 226 patients (mean age 66.9±11.5 years, 74.3% of women) were analyzed, excluding patients who followed-up for less than 5 years and patients whose baseline or follow-up echocardiography could not be analyzed. Clinical, echocardiographic, and laboratory data were collected early after the surgery and during follow-up. MVD was defined as an increase in mean gradient ≥5 mmHg with leaflet motion limitation and/or newly developed MV regurgitation during follow-up. Clinical outcome was defined as a composite of cardiovascular death, redo MV surgery or intervention, and hospitalization for heart failure.

Results

During a median of 102.0 months (interquartile range 72.0 to 132.0 months), 65 patients (28.8%) revealed MVD. 8 (12.3%) patients revealed predominant MV obstruction, and 57 (87.7%) showed predominant MV regurgitation. Factors associated with bio-prosthetic MVD by multivariate regression analysis were young age at operation (hazard ratio 0.97, 95% CI 0.95–0.99, p=0.001), end-stage renal disease (hazard ratio 4.29, 95% CI 1.45–12.71, p=0.007), elevated mean diastolic pressure gradient>5.5 mmHg across the bio-prosthetic MV early after operation (hazard ratio 1.86, 95% CI 0.97–3.74, p=0.063) and anemia after operation (hazard ratio 0.84, 95% CI 0.74–0.95, p=0.007). However, the presence of hypertension, dyslipidemia, or porcine bio-prosthesis was not related to the bio-prosthetic MVD. Kaplan-Meier curves revealed significant differences in event-free survivals for the occurrence of bio-prosthetic MVD according to each factor (Figure 1). Patients with bio-prosthetic MVD showed significantly poor clinical outcomes compared with those without bio-prosthetic MVD (event-free survival 43.1% vs. 91.9%, log-rank p<0.001) during the follow-up.

Conclusions

Young age at operation, end-stage renal disease, elevated mean pressure gradient early after the operation, and anemia after operation were associated with bio-prosthetic MVD in patients who underwent bio-prosthetic MV replacement.

Funding Acknowledgement

Type of funding sources: None.

First report of a resistance-breaking strain of Tomato spotted wilt orthotospovirus infecting Capsicum annuum carrying the Tsw resistance gene in South Korea

Tomato spotted wilt orthotospovirus (TSWV) was first reported in 2004 from paprika in South Korea (Kim et al., 2004), where it is currently widespread. TSWV infections were reported in chili pepper, tomato, weeds, and ornamental plant species in South Korea (Choi et al., 2014; Choi and Choi, 2015; Yoon et al., 2016; Yoon et al., 2018; Yoon et al., 2019). One of the best strategies for TSWV management is planting resistant cultivars containing the Tsw gene. In 2019 virus-like symptoms were observed in chili pepper (Capsicum annuum) plants bearing the Tsw gene in Anseong-si, South Korea. The infected chili peppers showed mosaic and wilting followed by necrosis on leaves and fruits in the field. To identify the causal virus, symptomatic leaf samples were analyzed using ImmunoStrip kits (Agdia, USA); we detected three pepper-infecting viruses: Pepper mild mottle virus, Cucumber mosaic virus, and TSWV. TSWV was only detected from 40 naturally infected chili pepper plants exhibiting virus-like symptoms. To further confirm the presence of TSWV (named TSWV-P1), we amplified reverse-transcription polymerase chain reaction (RT-PCR) products for L, M, and S RNA segments using tospovirus-specific and TSWV-specific primers (Batuman et al., 2014). Expected fragments of 445, 868, and 777 bp in length were amplified and sequenced. The complete genome sequences of TSWV-P1 from a symptomatic chili pepper plant were also determined using TSWV-specific primers (Choi et al., 2014; Lian et al., 2013). The complete genome sequences of TSWV-P1 were deposited to GenBank (LC549179, LC549180, and LC549181). The sequences of each fragment were identical to a consensus sequence, showing 99.1%, 98.5%, and 98.6% identity with TSWV-L, M, and S RNA (KP008132, AY744492, and KP008134), respectively. These results clearly showed only a single TSWV infection among the naturally infected chili pepper plants, without reassortment between TSWV and another tospovirus. To confirm whether TSWV-P1 is a resistance-breaking (RB) strain, Nicotiana rustica was mechanically inoculated with sap from leaves of the infected pepper samples to propagate TSWV-P1. A non-RB TSWV isolate (TSWV-Kor-lisianthus) from lisianthus was used as a control (Yoon et al., 2017). Two resistant (with Tsw) and two susceptible chili pepper cultivars (20 plants per cultivar) were mechanically inoculated with sap from leaves of the TSWV-infected N. rustica. The incidence rates of disease caused by TSWV-P1 were 90-100% for resistant and 95-100% for susceptible cultivars. In contrast, TSWV-Kor-lisianthus caused symptoms only in the susceptible pepper cultivars (90-100% incidence). TSWV infection in representative plants was confirmed using the TSWV- ImmunoStrip kit and RT-PCR. The NSs gene of TSWV-P1 consists of 1,404 nucleotides (468 amino acids); sequence analysis of the TSWV-P1 NSs gene showed high nucleotide (99.7%) and amino acid identities (99.8%) with the NSs sequences of two TSWV isolates (FR693035, CBX24121). Protein sequence analysis of TSWV-P1 NSs revealed that no amino acid mutation was associated with those of a representative TSWV RB strain, as previously described (Almási et al., 2017), suggesting that TSWV-P1 is a RB strain. Because this TSWV-P1 can overcome resistance conferred by the Tsw gene in commercially grown chili pepper cultivars, it represents a potential threat to pepper production in South Korea.

First report of Cucurbit chlorotic yellows virus infecting Cucumis melo (muskmelon and oriental melon) in Korea

In December 2018, virus-like symptoms (yellowing, vein clearing) were observed on 2% of muskmelon (Cucumis melo L.) plants in plastic houses on a farm in Gyeongsang province, Korea Total RNA from two symptomatic and two asymptomatic plants was extracted using RNeasy Plant Mini Kit (Qiagen, Germany) for high throughput sequencing (HTS). After pre-processing and Ribo-Zero rRNA removal, a cDNA library was prepared (Illumina TruSeq Stranded Total RNA kit) and sequenced (Illumina NovaSeq 6000 system: Macrogen Inc. Korea). De novo assembly of 88,222,684 HTS reads with Trinity software (r20140717) yielded 146,269 contigs of 201-28,442 bp, which were screened against the NCBI viral genome database by BLASTn. Contigs from cucumber mosaic virus (CMV), melon necrotic spot virus (MNSV), tobacco mosaic virus (TMV) and watermelon mosaic virus (WMV) were identified, all previously reported in Korea. Two contigs (8,539 and 8,040 bp) with 99.9% sequence identity to distinct cucurbit chlorotic yellows virus (CCYV) isolates (JN641883, RNA1, Taiwan; MH819191, RNA2, China) were also identified. The ten sequences most closely related to each RNA of the Korean isolate (≥99% coverage, ≥99.6% nt identity) were from Japan, China, Taiwan, or Israel. CCYV presence was confirmed by reverse transcription-PCR (RT-PCR) using newly designed specific primers, RdRp-F/RdRp-R (5'-ACCGAACACTTGGCTATCCAA-3'/5'-CTTAATGCCGCGTATGAACTCA-3') span style="font-family:'Times New Roman'; letter-spacing:-0.5pt">and HSP-F/HSP-R (5'-TGAACGACACTGAGTTCATTCCTA-3'/5'-CGCCAAGATCGTACATGAGGAA-3'), against RNA dependent RNA polymerase (RdRp; RNA1) and the heat shock protein 70 homolog (HSP70h; RNA2). Symptomatic samples yielded products of expected sizes (RdRp,450 bp; HSP70h, 510 bp) while asymptomatic samples did not. The amplicons were cloned, and two clones of each were sequenced (BIONEER, Korea; GenBank acc. nos. LC592226 and LC592227) showing 100% and 99.2% nt identity with RdRp and HSP70h genes of Chinese CCYV isolate SD (MH819190 and MH819191, respectively) and other Asian isolates. Primers specific for CMV, WMV, beet pseudo-yellows virus (BPYV) (Okuda et al., 2007), TMV (Kim et al., 2018), MNSV (F/R, 5'-ATCTCGCATTTGGCATTACTC-3'/5'-ATTTGTAGAGATGCCAACGTA-3'), cucurbit yellow stunting disorder virus (CYSDV; Zeng et al., 2011) and cucurbit aphid-borne yellows virus (CABYV; F/R, 5'-CGGTCTATTGTCTGCAGTACCA-3'/5'- GTAGAGGATCTTGAATTGGTCCTCA-3') were also used. None of these viruses were detected in the symptomatic samples, but both asymptomatic plants were positive for CMV and WMV, and one also for MNSV. In June and September 2020, muskmelon and oriental melon (Cucumis melo L. var. makuwa) plants with yellowing disease (incidence 80-90%) and whiteflies were observed in all investigated plastic houses of one muskmelon and one oriental melon farm in Gyeonggi and Jeolla provinces. Symptomatic samples (14 muskmelon; 6 oriental melon) were collected and RT-PCR tested as above; 19/20 samples were positive for CCYV, but none for the other viruses. The oriental melon sequence (LC592895, LC592230) showed 99.7% and 100% nt identity with the RdRp and HSP70h genes of Chinese isolate SD, respectively. CCYV was first reported in Japan (Okuda et al., 2010), Taiwan, and China (Huang et al., 2010; Gu et al., 2011); to our knowledge, this is the first report of CCYV infecting muskmelon and oriental melon in Korea. Whitefly-transmitted CCYV could present a serious threat of yield losses to cucurbit crops in Korea, requiring control of vector populations to prevent spread of CCYV.

First report of Passiflora latent virus(Passiflora latent virus;PLV) infecting persimmon in Korea

Passiflora latent virus (PLV), a member of the genus Carlavirus in the family Betaflexiviridae has been reported in Passiflora species in Australia, Germany, Israel, the United States, and New Zealand (Tang et al., 2008). In September 2019, leaves showing a virus-like disease with mosaic, curling and necrosis were collected from ten persimmon (Diospyros kaki Thunb.) orchards in Gyeongsang province, Korea. Total RNA from a pooled sample of leaves from 21 trees was extracted using RNeasy Plant Mini Kit (Qiagen, Germany) and subjected to high throughput sequencing. After pre-processing and Ribo-Zero rRNA Removal, a cDNA library was prepared using an Illumina TruSeq Stranded Total RNA Kit and sequenced on an Illumina NovaSeq 6000 system (Macrogen Inc. Korea). De novo assembly of the 74,862,810 reads was performed using Trinity software (r20140717); the initially assembled 213,476 contigs were screened against the NCBI viral genome database using BLASTN. By these means, 12 contigs derived from PLV were identified. Contigs with lengths of 209 to 802 nt shared nt identities of 90.70 to 94.82% with PLV isolates, covering a total of 5,169 nt (~61.6% of the full PLV genome). Two additional viruses were also detected from the pooled sample: persimmon cryptic virus (PeCV) and persimmon virus A (PeVA). To confirm PLV infection, reverse transcription-polymerase chain reaction (RT-PCR) was performed using virus-specific primers, PLV-F (5'-ACACAAAACTGCGTGTTGGA-3') and PLV-R (5'-CAAGACCCACCTACCTCAGTGTG-3'), designed based on a 633 nt contig sequence in the polymerase gene. RT-PCR products of the expected 571 bp were obtained from two of 21 individual original samples; no asymptomatic plants were tested. Amplicons were cloned into the pGEM-T Easy Vector, and two clones per sample Sanger sequenced bidirectionally (BIONEER, Korea). The identical Sequence (GenBank LC556232) showed 99.65% nt identity to the contig, and 93.87% identity with the corresponding polymerase sequence of PLV-Rehovot isolate from passion fruit in Israel (MH379331). The two PLV positive samples showing leaf necrosis were also co-infected with PeVA, identified by RT-PCR using previously reported primers PeVAfor/ PeVArev (Morell et al., 2014), but not with PeCV (mixed with PeVA in only 1/21 plants; PeVA was found in 19/21 plants). None of the tested viruses were detected in two trees, displaying mosaic, and leaf curling, respectively. The foliar symptoms of PLV infection on passionfruit have been reported to vary throughout the year (Spiegel et al., 2007). No such observations in persimmon was possible, as the infected persimmon trees were removed and destroyed because they might pose a threat to the cultivation of passion fruits in Korea. To our knowledge, this is the first report of persimmon as a host of PLV anywhere in the world, and the first report of PLV in Korea in any host. A further survey is needed to determine possible presence of PLV on persimmon and Passiflora species.

Evaluation of phenolic compounds from viroid-free and viroid-infected apples using HPLC-PDA-ESI-MS/MS

INTRODUCTION

Apples are the most consumed fruits in Korea and have played an economically important role in Korean agriculture. However, widespread viroid infection in apples had been reported in recent years.

OBJECTIVES

The objective of this study was to clarify the relationships between viroid-disease resistance and phenols content of three apple cultivars: "Fuji", "Gamhong", and "Hongro". A model for distinguishing between viroid-free and viroid-infected apples was also developed.

METHODOLOGY

Phenolic compounds in samples were detected using high-performance liquid chromatography photodiode array tandem mass spectrometry (HPLC-PDA-MS/MS) and quantified using an ultraviolet detector at 280 nm. A C₁₈ -column and 0.5% aqueous acetic acid-methanol were used as the stationary and mobile phase. The HPLC method was validated with respect to linearity, precision, accuracy, and recovery. Multivariate analysis was performed using phenols content as variables to classify viroid-free and viroid-infected apples.

RESULTS

An accurate method for identifying and quantifying phenol compounds in apple samples was developed and validated. In response to viroid infection, considerable increases in the content of dihydrochalcones (in all three cultivars), hydroxycinnamic acid (in "Fuji"), and flavonols (in "Hongro") were observed. The flavonols content in "Fuji" viroid-infected samples, however, decreased dramatically. An effective linear discriminant model, with 98.2% accuracy and 94.6% predictive ability, was achieved to discriminate between viroid-free and viroid-infected samples.

CONCLUSION

The developed HPLC method is suitable to identify and quantify phenol compounds in viroid-free and viroid-infected apples. A hypothesis about the significance of these compounds in viroid-disease resistance was proposed. The linear discriminant model with high predictive ability is useful for identifying viroid-infected apples in the orchards.

Strategies for controlling dog-mediated human rabies in Asia: using 'One Health' principles to assess control programmes for rabies

Over 99% of human rabies cases in endemic areas are transmitted by dogs. Without the elimination of dog rabies, it is not easy to reduce human rabies infection. Controlling dog rabies, especially in ownerless or free-roaming dogs, is critical if we are to decrease the rate of human rabies infection. There are several components in a strategy to eliminate dog-mediated rabies in Asia. Each government must make sure that rabies is either a reportable disease or a notifiable disease and enforce the reporting requirements accordingly. They must also focus on organising and operating special rabies control committees that work with relevant agencies under the 'One Health' banner. They should also implement a national rabies control programme that includes mass dog vaccination, laboratory-based surveillance, stable budget allocation, a rapidreporting system, management of dog populations, international cooperation, prevention of animal introductions from other countries, and risk assessment to analyse the programme's weaknesses. As several developed countries have shown, an effective rabies control strategy leads to rabies-free status. In the Republic of Korea, human rabies has not occurred since 2004, and there have not been any confirmed cases of dog rabies or cases of rabies in wild animals, including raccoon dogs, since 2014. The successful implementation of the key strategies used to eliminate rabies in the Republic of Korea will enable other Asian countries to eliminate dog-mediated human rabies.

Kushenol A and 8-prenylkaempferol, tyrosinase inhibitors, derived from Sophora flavescens

Tyrosinase is known for an enzyme that plays a key role in producing the initial precursor of melanin biosynthesis. Inhibition of the catalytic reaction of this enzyme led to some advantage such as skin-whitening and anti-insect agents. To find a natural compound with inhibitory activity towards tyrosinase, the five flavonoids of kushenol A (1), 8-prenylkaempferol (2), kushenol C (3), formononetin (4) and 8-prenylnaringenin (5) were isolated by column chromatography from a 95% methanol extract of Sophora flavescens. The ability of these flavonoids to block the conversion of L-tyrosine to L-DOPA by tyrosinase was tested in vitro. Compounds 1 and 2 exhibited potent inhibitory activity, with IC50 values less than 10 µM. Furthermore, enzyme kinetics and molecular docking analysis revealed the formation of a binary encounter complex between compounds 1–4 and the enzyme. Also, all of the isolated compounds (1–5) were confirmed to possess antioxidant activity.

Tyrosinase inhibitory components from the seeds of Cassia tora

Ten compounds (1-10) isolated from the seeds of Cassia tora were evaluated for tyrosinase inhibition. Compounds 3, 4, and 7 inhibited tyrosinase enzymatic activity in a dose-dependent manner, with IC₅₀ values of 3.0 ± 0.8, 7.0 ± 0.4, and 9.2 ± 3.4 μM, respectively. Kinetic analyses revealed a mechanism consistent with competitive inhibition. In silico molecular docking showed that compounds 3 and 4 docked in the active site of tyrosinase, whereas 7 interacted with Ala246 and Val248 at outside of the active site, and His244 and Glu256 at inside. Additionally, compounds 3, 4, and 7 suppressed melanogenesis in α-MSH-treated B16F10 melanoma cells at a concentration of 10 μM.

Inhibitory Components from Glycosmis stenocarpa on Pepper Mild Mottle Virus

The goal of this study was to identify a source of natural plant compounds with inhibitory activity against pepper mild mottle virus (PMMoV). We showed, using a half-leaf assay, that murrayafoline-A (1) and isomahanine (2) isolated from the aerial parts of Glycosmis stenocarpa have inhibitory activity against PMMoV through curative, inactivation, and protection effects. Using a leaf-disk assay, we confirmed that 2 inhibited virus replication in Nicotiana benthamiana. Using electron microscopy, we found that a mixture of the virus with 2 resulted in damage to the rod-shaped virus.

Tyrosinase inhibitory components from Aloe vera and their antiviral activity

A new compound, 9-dihydroxyl-2'-O-(Z)-cinnamoyl-7-methoxy-aloesin (1), and eight known compounds (2-9) were isolated from Aloe vera. Their structures were elucidated using 1D/2D nuclear magnetic resonance and mass spectra. Compound 9 exhibited reversible competitive inhibitory activity against the enzyme tyrosinase, with an IC₅₀ value of 9.8 ± 0.9 µM. A molecular simulation revealed that compound 9 interacts via hydrogen bonding with residues His244, Thr261, and Val283 of tyrosinase. Additionally, compounds 3 and 7 were shown by half-leaf assays to exhibit inhibitory activity towards Pepper mild mottle virus.

First Report of Cucumber mosaic virus in Saintpaulia ionantha in Korea

African violet (Saintpaulia ionantha) is an ornamental species of the family Gesneriaceae and is characterized by fleshy leaves and colorful flowers. This popular, exotic ornamental, originally from Kenya and Tanzania, is vegetatively produced from cutting and tissue culture (1). In May 2013, virus-like foliar symptoms, including a mosaic with dark green islands and chlorosis surrounding the veins, were observed on an African violet plant in a greenhouse located in Icheon, Korea. Cucumber mosaic virus (CMV) was identified in the symptomatic plant by serological testing for the presence of CMV coat protein (CP) with a commercial immunostrip kit (Agdia, Elkhart, IN). The presence of CMV was confirmed by serological detection with a commercially available double-antibody sandwich (DAS)-ELISA kit (Agdia). Sap from the serologically positive sample was mechanically inoculated to test plants using 10 mM phosphate buffer (pH 7.0). The virus (named CMV-AV1) caused necrotic local lesions on Chenopodium amaranticolor at 5 days post-inoculation (dpi), while mild to severe mosaic was observed in Nicotiana glutinosa, N. tabacum 'Samsun NN,' Cucurbita pepo 'Super-Top,' Physalis angulate, and Solanum lycopersicum 'Unicorn' 10 to 14 dpi. Examination of the inoculated plant leaves by DAS-ELISA and electron microscopy (leaf dips) showed positive reactions to CMV and the presence of spherical virions ∼28 nm in diameter, respectively. To verify whether CMV-AV1 is the cause of disease symptoms observed in African violet, virus-free African violet (10 plants) was mechanically inoculated by sap from local lesions on C. amaranticolor inoculated with CMV-AV1. At 8 weeks after inoculation, all plants produced systemic mosaic and chlorosis surrounding veins, resulting in strong DAS-ELISA reactions for CMV, whereas mock-inoculated African violet plants remained symptomless and virus-free. The presence of CMV-AV1 in all naturally infected and mechanically inoculated plants was further verified by reverse transcription (RT)-PCR. Total RNAs were extracted with the RNeasy Plant Mini Kit (Qiagen, Hilden, Germany), according to the manufacturer's instructions. RT-PCR was carried out with the One-Step RT-PCR Kit (Invitrogen, Carlsbad, CA) using a pair of primers, CPTALL3 and CPTALL5 (2), amplifying the entire CP gene and part of an intergenic region and 3'-noncoding region of CMV RNA3. RT-PCR products (960 bp) were obtained from all naturally infected and mechanically inoculated plants as well as from positive control (viral RNAs from virions), but not from healthy tissues. The amplified RT-PCR products were purified with QIAquick PCR Purification Kit (Qiagen) and sequenced using BigDye Termination kit (Applied Biosystems, Foster City, CA). Multiple alignment of the CMV-AV1 CP sequence (Accession No. AB842275) with CP sequences of other CMV isolates using MEGA5 software revealed that 91.8 to 99.0% and 71.0 to 73.0% identities to those of CMV subgroup I and subgroup II, respectively. These results provide additional confirmation of CMV-AV1 infection. CMV may pose a major threat for production of African violet since the farming of African violet plants is performed using the vegetative propagation of the African violet leaves in Korea. In particular, mosaic and chlorosis symptoms in African violet cause damage to ornamental quality of African violet. To our knowledge, this is the first report of CMV infection of African violet in the world. References: (1) S. T. Baatvik. Fragm. Flor. Geobot. Suppl. 2:97, 1993. (2) S. K. Choi et al. J. Virol. Methods 83:67, 1999.

First Report of Cherry necrotic rusty mottle virus Infecting Sweet Cherry Trees in Korea

Cherry necrotic rusty mottle virus (CNRMV), an unassigned member in the family Betaflexiviridae, has been reported in sweet cherry in North America, Europe, New Zealand, Japan, China, and Chile. The virus causes brown, angular necrotic spots, shot holes on the leaves, gum blisters, and necrosis of the bark in several cultivars (1). During the 2012 growing season, 154 sweet cherry trees were tested for the presence of CNRMV by RT-PCR. Samples were randomly collected from 11 orchards located in Gyeonggi and Gyeongsang provinces in Korea. RNA was extracted from leaves using the NucliSENS easyMAG system (bioMérieux, Boxtel, The Netherlands). The primer pair CGRMV1/2 (2) was used to amplify the coat protein region of CNRMV. Although none of the collected samples showed any notable symptoms, CNRMV PCR products of the expected size (949 bp) were obtained from three sweet cherry samples from one orchard in Gyeonggi province. The PCR products were cloned into a pGEM-T easy vector (Promega, Madison, WI) and sequenced. BLAST analyses of the three Korean sequences obtained (GenBank Accession Nos. AB822635, AB822636, and AB822637) showed 97% nucleotide sequence identity with a flowering cherry isolate from Japan (EU188439), and shared 98.8 to 99.6% nucleotide and 99.6 to 100% amino acid similarities to each other. The CNRMV positive samples were also tested for Apple chlorotic leaf spot virus (ACLSV), Cherry mottle leaf virus (CMLV), Cherry rasp leaf virus (CRLV), Cherry leafroll virus (CLRV), Cherry virus A (CVA), Little cherry virus 1 (LChV-1), Prune dwarf virus (PDV), and Prunus necrotic ringspot virus (PNRSV) by RT-PCR. One of the three CNRMV-positive samples was also infected with CVA. To confirm CNRMV infection by wood indexing, Prunus serrulata cv. Kwanzan plants were graft-inoculated with chip buds from the CNRMV-positive sweet cherry trees. At 3 to 4 weeks post-inoculation, the Kwanzan plants showed quick decline with leaves wilting and dying; CNRMV infection of the indicators was confirmed by RT-PCR. To our knowledge, this is the first report of CNRMV infection of sweet cherry trees in Korea. Screening for CNRMV in propagation nurseries should minimize spread of this virus within Korea. References: (1) R. Li and R. Mock. Arch. Virol. 153:973, 2008. (2) R. Li and R. Mock. J. Virol. Methods 129:162, 2005.

Bovine spongiform encephalopathy surveillance in the Republic of Korea

National surveillance for bovine spongiform encephalopathy (BSE) began in the Republic of Korea (ROK) in 1996. Surveillance programmes changed overtime to comply with the guidelines of the World Organisation for Animal Health (OIE). Bovine spongiform encephalopathy was designated as a notifiable disease in 1997. From July 2008, the BSE surveillance programme was intensified to test cattle in designated high-risk populations more effectively. New measures included the compulsory testing of all non-ambulatory cattle at abattoirs, and encouraging the testing of all dead cattle examined and recorded under the Mutual Aid Insurance Scheme (fallen stock). In addition, there was a vigorous search for animals suspected of being clinically infected. As a result, a total of 426,919 OIE points were achieved over a period of seven consecutive years to the end of October 2009. This enabled the submission of a successful application to the OIE in 2010 for recognition of the ROK's BSE disease status as being one of controlled risk, in accordance with Chapter 11.5. of the OIE Terrestrial Animal Health Code.

Actin Cytoskeleton and Golgi Involvement in Barley stripe mosaic virus Movement and Cell Wall Localization of Triple Gene Block Proteins

Barley stripe mosaic virus (BSMV) induces massive actin filament thickening at the infection front of infected Nicotiana benthamiana leaves. To determine the mechanisms leading to actin remodeling, fluorescent protein fusions of the BSMV triple gene block (TGB) proteins were coexpressed in cells with the actin marker DsRed: Talin. TGB ectopic expression experiments revealed that TGB3 is a major elicitor of filament thickening, that TGB2 resulted in formation of intermediate DsRed:Talin filaments, and that TGB1 alone had no obvious effects on actin filament structure. Latrunculin B (LatB) treatments retarded BSMV cell-to-cell movement, disrupted actin filament organization, and dramatically decreased the proportion of paired TGB3 foci appearing at the cell wall (CW). BSMV infection of transgenic plants tagged with GFP-KDEL exhibited membrane proliferation and vesicle formation that were especially evident around the nucleus. Similar membrane proliferation occurred in plants expressing TGB2 and/or TGB3, and DsRed: Talin fluorescence in these plants colocalized with the ER vesicles. TGB3 also associated with the Golgi apparatus and overlapped with cortical vesicles appearing at the cell periphery. Brefeldin A treatments disrupted Golgi and also altered vesicles at the CW, but failed to interfere with TGB CW localization. Our results indicate that actin cytoskeleton interactions are important in BSMV cell-to-cell movement and for CW localization of TGB3.

Insights into Alternanthera mosaic virus TGB3 Functions: Interactions with Nicotiana benthamiana PsbO Correlate with Chloroplast Vesiculation and Veinal Necrosis Caused by TGB3 Over-Expression

Alternanthera mosaic virus (AltMV) triple gene block 3 (TGB3) protein is involved in viral movement. AltMV TGB3 subcellular localization was previously shown to be distinct from that of Potato virus X (PVX) TGB3, and a chloroplast binding domain identified; veinal necrosis and chloroplast vesiculation were observed in Nicotiana benthamiana when AltMV TGB3 was over-expressed from PVX. Plants with over-expressed TGB3 showed more lethal damage under dark conditions than under light. Yeast-two-hybrid analysis and bimolecular fluorescence complementation (BiFC) reveal that Arabidopsis thaliana PsbO1 has strong interactions with TGB3; N. benthamiana PsbO (NbPsbO) also showed obvious interaction signals with TGB3 through BiFC. These results demonstrate an important role for TGB3 in virus cell-to-cell movement and virus-host plant interactions. The Photosystem II oxygen-evolving complex protein PsbO interaction with TGB3 is presumed to have a crucial role in symptom development and lethal damage under dark conditions. In order to further examine interactions between AtPsbO1, NbPsbO, and TGB3, and to identify the binding domain(s) in TGB3 protein, BiFC assays were performed between AtPsbO1 or NbPsbO and various mutants of TGB3. Interactions with C-terminally deleted TGB3 were significantly weaker than those with wild-type TGB3, and both N-terminally deleted TGB3 and a TGB3 mutant previously shown to lose chloroplast interactions failed to interact detectably with PsbO in BiFC. To gain additional information about TGB3 interactions in AltMV-susceptible plants, we cloned 12 natural AltMV TGB3 sequence variants into a PVX expression vector to examine differences in symptom development in N. benthamiana. Symptom differences were observed on PVX over-expression, with all AltMV TGB3 variants showing more severe symptoms than the WT PVX control, but without obvious correlation to sequence differences.

First Report of Blueberry red ringspot virus Infecting Highbush Blueberry in Korea

Blueberry red ringspot virus (BRRSV) of the Soymovirus genus in the family Caulimovididae causes red ringspot diseases in highbush blueberry (Vaccinium corymbosum L.) on leaves, stems, and fruits. The virus has been identified in the United States, Japan, Czech Republic, Slovenia, and Poland (1). In July 2010, highbush blueberry with red ringspots on leaves and circular blotches on ripening fruits was found in one plant of cv. Duke in Pyeongtaek, Korea. The symptoms were similar to red ringspot disease caused by BRRSV (3), although stems did not show any characteristic symptoms. Red ringspots on the upper surface of leaves were the most visible symptom and became more prominent as leaves matured in August through October. Leaves of the symptomatic plant were collected and tested for BRRSV infection by PCR, and were also embedded for electron microscopy. DNA was extracted from leaves using DNeasy Plant Mini Kit (Qiagen, Valencia, CA) according to the manufacturer's instructions. Primer pairs BR1512F/BR2377R (5'-ACAGGACGATTAGAAGATGG-3'/5'-CCTTTAGGGCAATATTTCTG-3', amplifying a fragment of the coat protein region with an expected size of 865 bp) and BR2961F/BR3726R (5'-ACCGATACATCACAGTTCAC-3'/5'-TGGTTGTGATAAGATGATTCC-3', amplifying a fragment of the reverse transcriptase region with an expected size of 766 bp) were used to amplify the indicated region of BRRV in PCR. Primers were designed on the basis of the BRRSV isolate from New Jersey (GenBank Accession No. AF404509). DNA fragments of the expected sizes were obtained from the symptomatic plant, while no amplification products were obtained from highbush blueberry without symptoms. The PCR products were cloned into pGEM-T easy vector (Promega, Madison, WI) and sequenced. BLAST analyses of obtained fragments revealed 91 to 98% nucleotide sequence identity with the coat protein gene (GenBank Accession No. JQ706341) and 96 to 98% nucleotide sequence identity with the reverse transcriptase gene (GenBank Accession No. JQ706340) of known BRRV isolates. Electron microscopy of thin sections revealed particles approximately 50 nm diameter within electron-dense inclusion bodies, characteristic of BRRSV (2) To our knowledge, this is the first report of BRRSV infection of highbush blueberry in Korea. Highbush blueberries are usually propagated by cutting, so BRRSV suspicious plants should be tested with PCR before they are propagated. References: (1) E. Kalinowska et al. Virus Genes. DOI 10.1007/s11262-011-0679-4, 2011. (2) K. S. Kim et al. Phytopathology 71:673, 1981. (3) M. Isogai et al. J. Gen. Plant Pathol. 75:140, 2009.

Gigacycle fatigue behavior by ultrasonic nanocrystalline surface modification

Nanocrystalline surface layer up to 84 microm in thick is produced on a specimen made of Al6061-T6 alloy by means of surface treatment called ultrasonic nanocrystalline surface modification (UNSM) technique. The refined grain size is produced in the top-layer and it is increased with increasing depth from the top surface. Vickers microhardness measurement for each nanocrystalline surface layer is performed and measurement results showed that the microhardness is increased from 116 HV up to 150 HV, respectively. In this study, fatigue behavior of Al6061-T6 alloy was studied up to 10(7)-10(9) cycles by using a newly developed ultrasonic fatigue testing (UFT) rig. The fatigue results of the UNSM-treated Al6061-T6 alloy specimens were compared with those of the untreated specimens. The microstructure of the untreated and UNSM-treated specimens was characterized by means of scanning electron microscopey (SEM) and transmission electron microscopey (TEM).

Diagnosis and control measures of the 2010 outbreak of foot-and-mouth disease A type in the Republic of Korea

In January 2010, foot-and-mouth disease (FMD) occurred for the first time in 8 years in Korea. The outbreaks were because of A serotype, different from the O type, which had occurred previously in 2000 and 2002. The FMD outbreaks were identified in seven farms, consisting of six cattle farms where viruses were detected and one deer farm where only FMDV antibody was detected. The seven farms were within 9.3 km of each other. All susceptible animals within 10 km radius of the outbreak farms were placed under movement restrictions for 3-11 weeks. No vaccination took place to facilitate the clinical observation of infected animals and virus detection. After clinical observations and serological tests within the control zones showed no evidence of FMD infection, the movement restrictions were lifted, followed by FMD-free declaration (23 March) at 80 days after the first outbreak on 2 January. This communication describes the outbreak of FMD A serotype, and control measures applied to eradicate the disease in Korea.

Student Experience and Satisfaction with Clinical Nursing Practice in Women's Health Nursing

PURPOSE

The purpose of this study was to identify students' experiences of performance and their satisfaction with clinical nursing practice in Women's health nursing.

METHODS

Data was collected using questionnaire consisting of 104; 89,; and 82 nursing activities with 12; 10; and 7 domains for delivery floor, obstetric, and gynecologic wards retrospectively. Five hundred ninety nursing students from 10 four year and one three year colleges, were recruited and selected for data collection.

RESULTS

Site specific core nursing activities among top 15 items of performed experience were: interpreting fetal monitoring; massage for pain reduction; breathing technique; perineal pad change; non stress test; manual check for uterine contraction; and position change for the delivery floor. Experiences of clinical nursing practice for the obstetric ward and the gynecologic ward were identified and ranked as well. Observation of delivery, measurement & test during labor and observation of anesthesia and operation were the highest ranked activity domains of satisfaction for delivery floor, obstetric and gynecologic wards retrospectively.

CONCLUSION

Discussions are needed to standardize curriculum for clinical practice in women's health nursing initiated at the level of Korean Society of Womens' Health Nursing by reflecting this result. Strategic approaches are emphasized in order to enhance a collaboration between clinical fields and colleges.

Knowledge representation of critical laboratory results in using the SAGE framework and challenges to its implementation

When a laboratory result is abnormal, the Computerized Critical Laboratory Results Alerting System should notify clinicians promptly. Use of this system can decrease the length of time spent in life-threatening situations, the average length of stay and the cost. 10 criteria oriented not to the individual but to a large number of patients were defined, these criteria were encoded using the SAGE framework. This type of modeling is utilized to validate a knowledge converter that converts the SAGE output to a knowledge engine.

Development and verification of a hypertension guideline encoding model

For encoding sharable and interoperable guideline knowledge for hypertension management, standard guidelines including JNC7 were chosen. The knowledge modeling process consisted of defining scenarios for describing workflow and identifying knowledge logics. Evaluation of the encoding model was conducted by scenario-based testing. Two experts inverted exclamation mark recommendations were compared with those inferred from the encoding model. The agreement level ranged from 77% to 100%.

Matching between the concepts of knowledge representation for a hypertension guideline and SNOMED CT

To support knowledge representation for the development of an interoperable clinical decision support system for hypertension management, matching of 228 concepts for HT management was conducted between knowledge representation concepts and SNOMED CT. 86.8% of the concepts were covered by direct matching. 7.5% were covered by compositional matching, and 5.7% were covered by general matching. The authors concluded that SNOMED CT is useful for representing knowledge concepts but does not cover all concepts without loss of semantics.

Pathogenic characteristics of the Korean 2002 isolate of foot-and-mouth disease virus serotype O in pigs and cattle

Experimental infection of susceptible cattle and pigs showed that the O/SKR/AS/2002 pig strain of foot-and-mouth disease virus (FMDV) causes an infection that is highly virulent and contagious in pigs but very limited in cattle. Pigs directly inoculated with, or exposed to swine infected with, strain O/SKR/AS/2002 showed typical clinical signs, including gross vesicular lesions in mouth and pedal sites. In addition, FMDV was isolated from, and FMDV genomic RNA was detected in, blood, serum, nasal swabs and oesophageal-pharyngeal (OP) fluid early in the course of infection. Antibodies against the non-structural protein (NSP) 3ABC were detected in both directly inoculated and contact pigs, indicating active virus replication. In contrast, the disease in cattle was atypical. After inoculation, lesions were confined to the infection site. A transient viraemia occurred 1 and 2 days after inoculation, and this was followed by the production of antibodies to NSP 3ABC, indicating subclinical infection. No clinical disease was seen, and no antibodies to NSP 3ABC were present in contact cattle. Additionally, no virus or viral nucleic acid was detected in blood, nasal swab and OP fluid samples from contact cattle. Thus, the virus appeared not to be transmitted from infected cattle to contact cattle. In its behaviour in pigs and cattle, strain O/SKR/AS/2002 resembled the porcinophilic FMDV strain of Cathay origin, O/TAW/97. However, the latter, unlike O/SKR/AS/2002, has reduced ability to grow in bovine-derived cells. The porcinophilic character of O/TAW/97 has been attributed to a deletion in the 3A coding region of the viral genome. However, O/SKR/AS/2002 has an intact 3A coding region.

The contribution of nursing data to the development of a predictive model for the detection of acute pancreatitis

The increasing use of information system has resulted in the accumulation of a large volume of nursing data in electronic medical records. These data have great potential for supporting the various clinical decisions made by physicians, nurses, and managers. However, how to re-use of nursing data remains largely an issue of informatics. The aim of this study was to demonstrate how these nursing data can be used and how much they could contribute to developing a predictive model for an expert system for early detection of acute pancreatitis. We employed a probability-based model consisting of a Bayesian network and trained this model with the patient data retrospectively retrieved from the enterprise data warehouse of a tertiary hospital. The performance of the predictive model was measured based on the error rate and the area under receiver operating characteristics curve, which were 13.89 % and 0.93, respectively. The sensitivity of the acute pancreatitis to the findings from each nursing data was measured using a test of sensitivity. The results showed that the role of nursing data is as important as laboratory data in formulating a model for an expert system.

Transition Model of Middle-aged Women

PURPOSE

The purpose of this study was to develop and test a model to explain the transition state for Korean middle-aged women focusing on the transition concept.

METHOD

A hypothetical model was constructed based on the transition model of Schumacher & Meleis(1994) and tested. The hypothetical model consisted of 5 latent variables and 11 observed variables. Exogenous variables were demographic characteristics, obstetric characteristics, and health behavior. Endogenous variables were transition state and quality of life with 6 paths. The data from 221 middle-aged women selected by convenience was analyzed using covariance structure analysis.

RESULT

The final model which was modified from the hypothetical model improved to GFI=0.97, AGFI=0.94, NFI=0.94, and NNFI=0.95. The transition state was influenced directly by demographic characteristics, quality of life, and also indirectly by health behaviors. However, the influence of obstetric characteristics was not significant. The transition state was accountable for 68% of the variance by these factors.

CONCLUSION

These results suggest that enhancing health behaviors of the women are necessary to increase quality of life and it consequently contributes to improving the transition state. This model could be used to explain the health related vulnerability in these ages and to diagnosis individual women.

Catalytically inactive lipoprotein lipase expression in muscle of transgenic mice increases very low density lipoprotein uptake: direct evidence that lipoprotein lipase bridging occurs in vivo

Lipoprotein lipase (LPL) is the central enzyme in plasma triglyceride hydrolysis. In vitro studies have shown that LPL also can enhance lipoprotein uptake into cells via pathways that are independent of catalytic activity but require LPL as a molecular bridge between lipoproteins and proteoglycans or receptors. To investigate whether this bridging function occurs in vivo, two transgenic mouse lines were established expressing a muscle creatine kinase promoter-driven human LPL (hLPL) minigene mutated in the catalytic triad (Asp156 to Asn). Mutated hLPL was expressed only in muscle and led to 3,100 and 3,500 ng/ml homodimeric hLPL protein in post-heparin plasma but no hLPL catalytic activity. Less than 5 ng/ml hLPL was found in preheparin plasma, indicating that proteoglycan binding of mutated LPL was not impaired. Expression of inactive LPL did not rescue LPL knock-out mice from neonatal death. On the wild-type (LPL2) background, inactive LPL decreased very low density lipoprotein (VLDL)-triglycerides. On the heterozygote LPL knock-out background (LPL1) background, plasma triglyceride levels were lowered 22 and 33% in the two transgenic lines. After injection of radiolabeled VLDL, increased muscle uptake was observed for triglyceride-derived fatty acids (LPL2, 1.7x; LPL1, 1.8x), core cholesteryl ether (LPL2, 2.3x; LPL1, 2.7x), and apolipoprotein (LPL1, 1.8x; significantly less than cholesteryl ether). Skeletal muscle from transgenic lines had a mitochondriopathy with glycogen accumulation similar to mice expressing active hLPL in muscle. In conclusion, it appears that inactive LPL can act in vivo to mediate VLDL removal from plasma and uptake into tissues in which it is expressed.