Enantioselective Synthesis of (R)-Sitagliptin via Phase-Transfer Catalytic aza-Michael Addition

The highly enantioselective synthesis of (R)-sitagliptin has been achieved through a series of key steps, including the aza-Michael addition and Baeyer-Villiger oxidation. The enantioselective aza-Michael addition involved the reaction of tert-butyl β-naphthylmethoxycarbamate with (E)-1-(4-methoxyphenyl)-4-(2,4,5-trifluorophenyl)but-2-en-1-one, utilizing a quinine-derived C(9)-urea ammonium catalyst under phase-transfer catalytic conditions. The aza-Michael addition successfully introduced chirality to the amine in (R)-sitagliptin with 96% ee. The subsequent Baeyer-Villiger oxidation of the aza-Michael adduct led to the formation of 4-methoxyphenyl ester. Hydrolysis and amide coupling were then employed to construct the amide moiety. Further deprotections were performed to complete the synthesis of (R)-sitagliptin (7 steps, 41%, 96% ee).

XPA tumor variant leads to defects in NER that sensitize cells to cisplatin

Nucleotide excision repair (NER) reduces efficacy of treatment with platinum (Pt)-based chemotherapy by removing Pt lesions from DNA. Previous study has identified that missense mutation or loss of the NER genes Excision Repair Cross Complementation Group 1 and 2 (ERCC1 and ERCC2) leads to improved patient outcomes after treatment with Pt-based chemotherapies. Although most NER gene alterations found in patient tumors are missense mutations, the impact of mutations in the remaining nearly 20 NER genes is unknown. Towards this goal, we previously developed a machine learning strategy to predict genetic variants in an essential NER protein, Xeroderma Pigmentosum Complementation Group A (XPA), that disrupt repair. In this study, we report in-depth analyses of a subset of the predicted variants, including in vitro analyses of purified recombinant protein and cell-based assays to test Pt agent sensitivity in cells and determine mechanisms of NER dysfunction. The most NER deficient variant Y148D had reduced protein stability, weaker DNA binding, disrupted recruitment to damage, and degradation. Our findings demonstrate that tumor mutations in XPA impact cell survival after cisplatin treatment and provide valuable mechanistic insights to improve variant effect prediction. Broadly, these findings suggest XPA tumor variants should be considered when predicting chemotherapy response.

A simplified cranial cavity model to understand the relationship between intracranial pressure and dural sinus pressure

Although accurate intracranial pressure (ICP) monitoring is essential for the diagnosis and treatment of severe brain diseases, current methods are performed invasively. Therefore, a safe and less invasive ICP measurement is required. The purpose of our study was to develop a simplified cranial cavity model for a better understanding of the relationship between the ICP and the pressure measurement within the dural venous sinus (DVS) to support the validity of using sinus pressure as the surrogate of the ICP. The in-house cranial cavity model had three components: the brain part, the DVS part, and the subarachnoid space (SAS) part. Pressure in other parts was measured when the pressure in the SAS part and, separately, brain part was increased from 0 (baseline) to 50 mmHg at intervals of 10 mmHg. When the pressure in the SAS part was increased from 10 to 50 mmHg at 10 mmHg interval, pressures of both the brain and DVS parts increased without significant difference (all P > 0.05). However, pressures in both the SAS and DVS parts differed while the pressure in the brain part was increased. The pressures in both parts showed about 70% of the increase in the brain part. Nevertheless, the pressures in the SAS and DVS parts were not significantly different (P > 0.05). A simplified in-house cranial cavity model was developed consisting of three compartments to represent the actual intracranial spaces. The pressure measurement within the DVS was feasible to use as a surrogate for the ICP measurement.

GPCR-IPL score: multilevel featurization of GPCR-ligand interaction patterns and prediction of ligand functions from selectivity to biased activation

G-protein-coupled receptors (GPCRs) mediate diverse cell signaling cascades after recognizing extracellular ligands. Despite the successful history of known GPCR drugs, a lack of mechanistic insight into GPCR challenges both the deorphanization of some GPCRs and optimization of the structure-activity relationship of their ligands. Notably, replacing a small substituent on a GPCR ligand can significantly alter extracellular GPCR-ligand interaction patterns and motion of transmembrane helices in turn to occur post-binding events of the ligand. In this study, we designed 3D multilevel features to describe the extracellular interaction patterns. Subsequently, these 3D features were utilized to predict the post-binding events that result from conformational dynamics from the extracellular to intracellular areas. To understand the adaptability of GPCR ligands, we collected the conformational information of flexible residues during binding and performed molecular featurization on a broad range of GPCR-ligand complexes. As a result, we developed GPCR-ligand interaction patterns, binding pockets, and ligand features as score (GPCR-IPL score) for predicting the functional selectivity of GPCR ligands (agonism versus antagonism), using the multilevel features of (1) zoomed-out 'residue level' (for flexible transmembrane helices of GPCRs), (2) zoomed-in 'pocket level' (for sophisticated mode of action) and (3) 'atom level' (for the conformational adaptability of GPCR ligands). GPCR-IPL score demonstrated reliable performance, achieving area under the receiver operating characteristic of 0.938 and area under the precision-recall curve of 0.907 (available in gpcr-ipl-score.onrender.com). Furthermore, we used the molecular features to predict the biased activation of downstream signaling (Gi/o, Gq/11, Gs and β-arrestin) as well as the functional selectivity. The resulting models are interpreted and applied to out-of-set validation with three scenarios including the identification of a new MRGPRX antagonist.

XPA tumor variants lead to defects in NER that sensitize cells to cisplatin

Nucleotide excision repair (NER) neutralizes treatment with platinum (Pt)-based chemotherapy by removing Pt lesions from DNA. Previous study has identified that missense mutation or loss of either of the NER genes Excision Repair Cross Complementation Group 1 and 2 ( ERCC1 and ERCC2 ) leads to improved patient outcomes after treatment with Pt-based chemotherapies. Although most NER gene alterations found in patient tumors are missense mutations, the impact of such mutations in the remaining nearly 20 NER genes is unknown. Towards this goal, we previously developed a machine learning strategy to predict genetic variants in an essential NER scaffold protein, Xeroderma Pigmentosum Complementation Group A (XPA), that disrupt repair activity on a UV-damaged substrate. In this study, we report in-depth analyses of a subset of the predicted NER-deficient XPA variants, including in vitro analyses of purified recombinant protein and cell-based assays to test Pt agent sensitivity in cells and determine mechanisms of NER dysfunction. The most NER deficient variant Y148D had reduced protein stability, weaker DNA binding, disrupted recruitment to damage, and degradation resulting from tumor missense mutation. Our findings demonstrate that tumor mutations in XPA impact cell survival after cisplatin treatment and provide valuable mechanistic insights to further improve variant effect prediction efforts. More broadly, these findings suggest XPA tumor variants should be considered when predicting patient response to Pt-based chemotherapy.

Significance

A destabilized, readily degraded tumor variant identified in the NER scaffold protein XPA sensitizes cells to cisplatin, suggesting that XPA variants can be used to predict response to chemotherapy.

Development of a scintillator-based optical soft x-ray (OSXR) diagnostic system for KSTAR tokamak

We have developed a new scintillator-based optical soft x-ray (OSXR) diagnostic system for KSTAR. By utilizing fiber optic faceplates, mm-size lens arrays, and fiber bundles, we have successfully constructed a novel optical system for scintillator-based soft x-ray detection to overcome the limited vacuum-port conditions in KSTAR. P47 (Y2SiO5), which has a fast rise (∼7 ns) and decay (∼100 ns) time sufficient for detecting plasma instabilities observed in the kHz-MHz spectral range, was selected as the scintillator material for the KSTAR OSXR system. Scintillation toward each detection channel is collected by the lens arrays coupled to optical fiber cores, which are connected to the photodetector system. Initial results obtained during the 2022 KSTAR experimental campaign support the validity of the OSXR data through the consistency of OSXR measurement results with other diagnostics. We also observe that the OSXR system can capture magnetohydrodynamic activities, such as sawtooth oscillations, and provide valuable information for disruption mitigation studies using shattered pellet injection.

A disease-associated XPA allele interferes with TFIIH binding and primarily affects transcription-coupled nucleotide excision repair

XPA is a central scaffold protein that coordinates the assembly of repair complexes in the global genome (GG-NER) and transcription-coupled nucleotide excision repair (TC-NER) subpathways. Inactivating mutations in XPA cause xeroderma pigmentosum (XP), which is characterized by extreme UV sensitivity and a highly elevated skin cancer risk. Here, we describe two Dutch siblings in their late forties carrying a homozygous H244R substitution in the C-terminus of XPA. They present with mild cutaneous manifestations of XP without skin cancer but suffer from marked neurological features, including cerebellar ataxia. We show that the mutant XPA protein has a severely weakened interaction with the transcription factor IIH (TFIIH) complex leading to an impaired association of the mutant XPA and the downstream endonuclease ERCC1-XPF with NER complexes. Despite these defects, the patient-derived fibroblasts and reconstituted knockout cells carrying the XPA-H244R substitution show intermediate UV sensitivity and considerable levels of residual GG-NER (~50%), in line with the intrinsic properties and activities of the purified protein. By contrast, XPA-H244R cells are exquisitely sensitive to transcription-blocking DNA damage, show no detectable recovery of transcription after UV irradiation, and display a severe deficiency in TC-NER-associated unscheduled DNA synthesis. Our characterization of a new case of XPA deficiency that interferes with TFIIH binding and primarily affects the transcription-coupled subpathway of nucleotide excision repair, provides an explanation of the dominant neurological features in these patients, and reveals a specific role for the C-terminus of XPA in TC-NER.

Real-Time Visualizing Nucleation and Growth of Electrodes for Post-Lithium-Ion Batteries

ConspectusUntil recently, most studies on nucleation and growth mechanisms have employed electrochemical transient measurements, and numerous models have been established on various metal electrode elements. Contrary to the conventional tip-induced nucleation and growth model, a base-induced nucleation and growth mode was discovered not so long ago, which highlighted the importance of direct real-time observations such as visualization. As analysis techniques developed, diverse in situ/operando imaging methods have spurred the fundamental understanding of complex and dynamic battery electrochemistry. Experimental observations of alkali Li and Na metals are limited and difficult because their high reactivity makes not only the fabrication but also the analysis itself challenging. Na metal has high reactivity to electrolytes. Accordingly, it is difficult to visualize the Na deposition in real-time due to gas evolution and resolution limitation. Only a few studies have examined the Na deposition and dissolution reactions in operando. It is generally believed that the Mg anode is free from the dendrite growth of Mg metal, and Mg deposition preferentially occurs along the surface direction. However, whether the Mg anode always follows the dendrite-free growth has currently become a controversial topic and is being discussed and redefined based on real-time imaging analyses. In addition, a variety of morphological evolutions in the metal anodes are required to be systematically distinguished by key parameters. Real-time imaging analysis can directly confirm the solid-liquid-solid multiphase conversion reactions of S and Se cathodes. S and Se elements belong to the same chalcogen group, but their crystal structures and morphological changes significantly differ in each electrode during deposition and dissolution reactions. Therefore, it is necessitated to discuss the nucleation and growth behaviors by examining intrinsic properties of each element in chalcogen cathodes. Considering that a mechanistic understanding of the Se cathode is in its infancy, its nucleation and growth behaviors must be further explored through fundamental studies. In this Account, we aim to discuss the nucleation and growth behaviors of metal (Li, Na, and Mg) anodes and chalcogen (S and Se) cathodes. To elucidate their nucleation and growth mechanisms, we overview the morphological evolutions on the electrode surface and interface by in situ/operando visualizations. Our recent studies covering Li, Na, Mg, S, and Se electrodes verified by operando X-ray imaging are used as critical resources in understanding their nucleation and growth behaviors. Overall, with validation of the complex and dynamic nucleation and growth behaviors of metal and chalcogen electrodes by in situ/operando visualization methods, we hope that this Account can contribute to supporting the fundamental knowledge for the development of high-energy-density metal and chalcogen electrodes.

Effect of early hysterectomy on a risk of incident cardiovascular disease in women: a nationwide population-based cohort study

Aim

Women who inevitably underwent surgical hysterectomy before natural menopause may have an earlier increase in hematocrit and storage iron than women who continue menstruation, thereby increasing the risk of cardiovascular disease (CVD) early. We aimed to evaluate the association of women with hysterectomy vs. without hysterectomy before their 50s with the risk of incident CVD.

Methods

This was a retrospective-cohort study, 135,575 women aged 40 to 50 years in 2011–2014 were extracted from the Korean Health Insurance Review and Assessment Service data and after propensity score matching, 55,539 pairs were included in hysterectomy and non-hysterectomy group respectively. The primary endpoint was major adverse cardiac and cerebrovascular events (MACCE), a composite of cardiovascular death, myocardial infarction (MI), stroke, and coronary artery revascularization.

Results

After adjustment for confounding factors, hysterectomy group had an increased risk of MACCE compared with non-hysterectomy group (hazard ratio [HR], 1.25; 95% confidence interval [CI], 1.09–1.44). Regarding individual outcomes, cardiovascular death, MI, and coronary revascularization were comparable between the groups, whereas, the risk of stroke was significantly higher in hysterectomy group than non-hysterectomy group (HR, 1.31; 95% CI, 1.12–1.53). Even after excluding women who underwent oophorectomy, hysterectomy group had a higher risk of MACCE than non-hysterectomy group (HR, 1.24; 95% CI 1.06–1.44).

Conclusions

Early surgical menopause due to hysterectomy, not hormonal menopause, was associated with an increased risk for a composite of CVD, especially stroke. This suggest that the role of “uterus” as well as sex hormones may be important for the sharp increase in the risk of CVD in women after menopause.

Funding Acknowledgement

Type of funding sources: None.

Blunted atrial reverse remodeling a year after catheter ablation for atrial fibrillation and their long-term rhythm outcome

Background

Although active rhythm control by atrial fibrillation (AF) catheter ablation (AFCA) reduces left atrial (LA) dimension, blunted atrial reverse remodeling can be observed in patients with significant atrial myopathy. We explored the characteristics and long-term outcomes of AF patients who showed blunted atrial reverse remodeling despite no AF recurrence within a year after AFCA.

Methods

Among a total of 2,756 patients with AFCA, we included 1,685 patients (74.8% male, 60.2±10.1 years old, 54.5% paroxysmal AF) who underwent both baseline and 1-year follow-up echocardiogram, baseline LA>40mm, and did not recur within a year. We divided them into tertile groups (T1–T3) based on one-year percent change of LA dimension after propensity matching for age, sex, AF type, and baseline LA dimension. We also investigated the patients' genetic characteristics with blunted LA reverse remodeling (T1) using a genome-wide association study (GWAS).

Results

Patients with blunted LA reverse remodeling (T1, n=424) were independently associated with body mass index (OR 1.082 [1.010–1.160], p=0.025), LA peak pressure (OR 1.010 [1.002–1.019], p=0.019), LA wall thickness (OR 0.448 [0.252–0.789], p=0.006), LA voltage (OR 0.651 [0.463–0.907], p=0.012), and pericardial fat volume (OR 1.004 [1.001–1.008], p=0.014). Throughout 65.9±37.4 months of follow-up, the incidence of AF recurrence a year after the procedure was significantly higher in the T1 group than in T2 or T3 groups (Log-rank p<0.001). Among 894 patients with GWAS, ATXN1, XPO7, KRR1_PHLDA1, ZFHX3, and their polygenic risk score were associated with blunted LA reverse remodeling.

Conclusions

Patients with blunted LA reverse remodeling after AFCA were independently associated with low LA voltage, thin wall thickness, high LA pressure, and fat volume, and have a genetic background. Long-term clinical recurrence a year after AFCA was higher in this patient group with suspicious atrial myopathy.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Health and WelfareNational Research Foundation of Korea

Two interaction surfaces between XPA and RPA organize the preincision complex in nucleotide excision repair

The xeroderma pigmentosum protein A (XPA) and replication protein A (RPA) proteins fulfill essential roles in the assembly of the preincision complex in the nucleotide excision repair (NER) pathway. We have previously characterized the two interaction sites, one between the XPA N-terminal (XPA-N) disordered domain and the RPA32 C-terminal domain (RPA32C), and the other with the XPA DNA binding domain (DBD) and the RPA70AB DBDs. Here, we show that XPA mutations that inhibit the physical interaction in either site reduce NER activity in biochemical and cellular systems. Combining mutations in the two sites leads to an additive inhibition of NER, implying that they fulfill distinct roles. Our data suggest a model in which the interaction between XPA-N and RPA32C is important for the initial association of XPA with NER complexes, while the interaction between XPA DBD and RPA70AB is needed for structural organization of the complex to license the dual incision reaction. Integrative structural models of complexes of XPA and RPA bound to single-stranded/double-stranded DNA (ss/dsDNA) junction substrates that mimic the NER bubble reveal key features of the architecture of XPA and RPA in the preincision complex. Most critical among these is that the shape of the NER bubble is far from colinear as depicted in current models, but rather the two strands of unwound DNA must assume a U-shape with the two ss/dsDNA junctions localized in close proximity. Our data suggest that the interaction between XPA and RPA70 is key for the organization of the NER preincision complex.

Active DNA damage eviction by HLTF stimulates nucleotide excision repair

Nucleotide excision repair (NER) counteracts the onset of cancer and aging by removing helix-distorting DNA lesions via a "cut-and-patch"-type reaction. The regulatory mechanisms that drive NER through its successive damage recognition, verification, incision, and gap restoration reaction steps remain elusive. Here, we show that the RAD5-related translocase HLTF facilitates repair through active eviction of incised damaged DNA together with associated repair proteins. Our data show a dual-incision-dependent recruitment of HLTF to the NER incision complex, which is mediated by HLTF's HIRAN domain that binds 3'-OH single-stranded DNA ends. HLTF's translocase motor subsequently promotes the dissociation of the stably damage-bound incision complex together with the incised oligonucleotide, allowing for an efficient PCNA loading and initiation of repair synthesis. Our findings uncover HLTF as an important NER factor that actively evicts DNA damage, thereby providing additional quality control by coordinating the transition between the excision and DNA synthesis steps to safeguard genome integrity.

Asymmetric Epoxidation of Enones: Effect of Surfactants, Radical Scavengers and Morphology of Catalysts on Reaction Rates, Chemical Yields and Enantioselectivities in Phase-Transfer Catalysis

Highly enantioselective epoxidation of enones has been accomplished with asymmetric phase-transfer catalysis (PTC) using cinchona alkaloid-derived meta-dimer catalysts. An intensive study of structure-reactivity relationships among catalysts and oxidants in terms...

Chitosan-Alginate-Pectin-coated Suspended-Liquid-Encapsulating (CAPSuLE) marbles for therapeutic agent storage and delivery

Developing a cutting-edge system capable of ensuring long-lasting functionality of therapeutic agents and implementing diverse delivery modes is challenging. A quasi-spherical triple-layered capsule containing suspended liquid droplets and allowing multi-modal delivery of therapeutic agents in the aqueous phase was developed, primarily by adopting the core principles for creating liquid marbles. A naturally derived wettable polysaccharide-pectin-was utilized as a liquid-air interfacial barrier to keep the liquid droplets in the core zone. To tailor the pectin-coated droplet as a therapeutic agent carrier, anionic alginate and cationic chitosan layers were sequentially formed via additional interactions: physically stacking substances with structural chirality (pectin-alginate) and inducing electrostatic association to create the reversible complex coacervates (alginate-chitosan). The resulting system, which is called a Chitosan-Alginate-Pectin-coated Suspended-Liquid-Encapsulating (CAPSuLE) marble, had sufficient mechanical strength to resist external harsh environments and exhibited unique features: ecofriendly sustainability, responsiveness to external stimuli, coacervate-driven coalescence for linking adjacent marbles, and a self-repairing ability. The proposed CAPSuLE system can facilitate the adoption of the liquid-marble concept to biomedical fields, extending its applicability in the fields of biology and applied engineering.

Observation of Coulomb-Assisted Nuclear Bound State of Ξ^{-}-^{14}N System

In an emulsion-counter hybrid experiment performed at J-PARC, a Ξ^{-} absorption event was observed which decayed into twin single-Λ hypernuclei. Kinematic calculations enabled a unique identification of the reaction process as Ξ^{-}+^{14}N→_{Λ}^{10}Be+_{Λ}^{5}He. For the binding energy of the Ξ^{-} hyperon in the Ξ^{-}-^{14}N system a value of 1.27±0.21  MeV was deduced. The energy level of Ξ^{-} is likely a nuclear 1p state which indicates a weak ΞN-ΛΛ coupling.

Comparison of biopsy strategies for prostate biopsy according to lesion size and PSA density in MRI-directed biopsy pathway

PURPOSE

To investigate whether the detection of clinically significant prostate cancer (csPCa) and the added value of focal saturation biopsy and systematic biopsy (SBx) differ according to index lesion size, and to compare the current guidelines for csPCa detection.

METHODS

This retrospective study included consecutive men who underwent MRI and subsequent SBx and MRI-targeted biopsy (TBx) for a suspicious lesion between April 2019 and February 2020. Lesion visibility on transrectal ultrasound (US) and added value of focal saturation biopsy and SBx were compared according to index lesion size using chi-square and McNemar tests. csPCa detection rates and the proportion of biopsy-indicated men were compared among four biopsy strategies based on current guidelines.

RESULTS

Of 313 men evaluated (median age, 65; interquartile range 60‒71), csPCa was detected in 110 (35%). In lesions < 10 mm, greater US invisibility (42.7% of lesions < 10 mm versus 20.0% of lesions ≥ 10 mm; p < 0.001) and higher added value of focal saturation biopsy and SBx (11.1% and 17.1% in lesions < 10 mm versus 4.2% and 6.3% in lesions ≥ 10 mm) were observed, compared with lesions ≥ 10 mm. Consideration of prostate-specific antigen (PSA) density > 0.15 ng/mL/mL as a cutoff in unsuspicious MRI led to a 14% reduction (44/313) in men who needed biopsy.

CONCLUSION

Determination of the biopsy strategy in terms of the need for focal saturation biopsy or SBx should be made considering lesion size. The use of PSA density in non-suspicious MRI can lead to a reduction in biopsy-indicated men.

Transverse Single-Spin Asymmetry for Very Forward Neutral Pion Production in Polarized p+p Collisions at sqrt[s]=510 GeV

Transverse single-spin asymmetries of very forward neutral pions generated in polarized p+p collisions allow us to understand the production mechanism in terms of perturbative and nonperturbative strong interactions. During 2017, the RHICf Collaboration installed an electromagnetic calorimeter in the zero-degree region of the STAR detector at the Relativistic Heavy Ion Collider (RHIC) and measured neutral pions produced at pseudorapidity larger than 6 in polarized p+p collisions at sqrt[s]=510  GeV. The large nonzero asymmetries increasing both in longitudinal momentum fraction x_{F} and transverse momentum p_{T} have been observed at low transverse momentum p_{T}<1  GeV/c for the first time, at this collision energy. The asymmetries show an approximate x_{F} scaling in the p_{T} region where nonperturbative processes are expected to dominate. A non-negligible contribution from soft processes may be necessary to explain the nonzero neutral pion asymmetries.

Major Lipids, Apolipoproteins, and Alterations of Gut Microbiota

The gut microbiota has been linked to blood lipids. However, the relationship between the gut microbiome and other lipid markers like apolipoproteins A1 (apoA1) and B (apoB) as well as classical lipid markers in Asians remain unclear. Here, we examined the associations between gut microbial diversity and taxonomic compositions with both apolipoproteins and lipid markers in a large number of Korean patients. The fecal 16S rRNA gene sequencing data from 1141 subjects were analyzed and subjects were categorized into control group (G0) or abnormal group (G1) according to blood lipid measurements. The microbial diversity and several taxa of the gut microbiota were significantly associated with triglyceride, apoA1, and apoB levels, but not with total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol levels. The alpha diversity of the gut microbiota was inversely associated with high triglyceride level. Interestingly, G1 of apoA1 showed increased microbial richness and distinct microbial community compared with G0 of apoA1. A high abundance of Fusobacteria and low abundance of Oscillospira were found in the hypertriglyceridemia group. In this large-scale study, we identified associations of gut microbiota with apolipoproteins and classical lipid markers, indicating that the gut microbiota may be an important target for regulating blood lipids.

Predictors of permanent stoma creation in patients with mid or low rectal cancer: results of a multicentre cohort study with preoperative evaluation of anal function

AIM

Preoperative factors predictive of permanent stoma creation were investigated in a long-term follow-up of patients with mid or low rectal cancer.

METHOD

We included patients who underwent radical resection for mid or low rectal cancer with available data for preoperative anal function measured by manometry and Faecal Incontinence Severity Index questionnaire between January 2005 and December 2015 in three tertiary referral hospitals. A permanent stoma was defined as a stoma present until the patient's last follow-up visit or death. Preoperative factors that predicted permanent stoma creation were analysed.

RESULTS

Over a median follow-up of 57.4 months (range 12-143 months), a permanent stoma was created in 144/577 (25.0%) patients, including 89 (15.4%) who underwent abdominoperineal resection, one (0.2%) who underwent Hartmann's operation without reversal, 15 (2.6%) with a diverting ileostomy at the time of initial sphincter-preserving surgery without undergoing stoma reversal, and 39 (6.8%) who underwent permanent ileostomy formation after sphincter-preserving surgery. Patients with permanent stoma creation had a shorter tumour distance from the anal verge (P < 0.001), larger tumour size (P = 0.020) and higher preoperative Faecal Incontinence Severity Index score (P = 0.020). On multivariable analysis, tumour distance from the anal verge predicted permanent stoma formation (relative risk 0.53 per centimetre increase; 95% confidence interval 0.46-0.60; P < 0.001) but preoperative anal function did not.

CONCLUSION

Tumour distance from the anal verge was the only preoperative determinant of permanent stoma creation in rectal cancer patients. These data may help mid and low rectal cancer patients understand the need for permanent stoma.

Effect of intraoperative Hartmann's versus hypotonic solution administration on FLACC pain scale scores in children: A prospective randomized controlled trial

Background

In healthy children, an isotonic solution containing no glucose or a small amount of glucose (1–2%) has been recommended as an intraoperative maintenance fluid due to the potential risk of hyponatremia associated with hypotonic solutions. However, a hypotonic solution with glucose is still widely used as a maintenance fluid for pediatric anesthesia. We speculated that the hypotonic solution may worsen postoperative discomfort and irritability in pediatric patients due to hyponatremia.

Patients and methods

In the current study, we compared the post-operative Face, Legs, Activity, Cry, Consolability(FLACC) scale scores of pediatric patients aged 3–10 years who received either a 1:2 dextrose solution or Hartmann's solution during Nuss Bar removal.

Results

The FLACC scale score in the post-anesthesia care unit was higher in the 1:2 dextrose solution group(HYPO) (n = 20) than in the Hartmann’s solution group(ISO) (n = 20) (6.30 vs 4.70, p = 0.044, mean difference and 95% Confidence Interval(CI) was 1.6 (0.04 to 3.16)). We also compared opioid consumption at the post-anesthesia care unit. Total dose of fentanyl per body weight in the post-anesthesia care unit was also higher in the HYPO (0.59 vs 0.37 mcg/kg, p = 0.042, mean difference and 95% CI was 0.22 mcg/kg (0.030 to 0.402)).

Conclusions

Intraoperative use of the hypotonic solution in children causes increased FLACC scale scores, leading to higher opioid consumption in post-anesthesia care unit.

A Stilbenoid Isorhapontigenin as a Potential Anti-Cancer Agent against Breast Cancer through Inhibiting Sphingosine Kinases/Tubulin Stabilization

Isorhapontigenin (ISO), a tetrahydroxylated stilbenoid, is an analog of resveratrol (Rsv). The various biological activities of Rsv and its derivatives have been previously reported in the context of both cancer and inflammation. However, the anti-cancer effect of ISO against breast cancer has not been well established, despite being an orally bioavailable dietary polyphenol. In this study, we determine the anti-cancer effects of ISO against breast cancer using MCF7, T47D, and MDA-MB-231 cell lines. We observed that ISO induces breast cancer cell death, cell cycle arrest, oxidative stress, and the inhibition of cell proliferation. Additionally, sphingosine kinase inhibition by ISO controlled tubulin polymerization and cancer cell growth by regulating MAPK/PI3K-mediated cell cycle arrest in MCF7 cells. Interestingly, SPHK1/2 gene silencing increased oxidative stress, cell death, and tubulin destabilization in MCF7 cells. This suggests that the anti-cancer effect of ISO can be regulated by SPHK/tubulin destabilization pathways. Overall, ISO successfully induced breast cancer cell death and cell growth arrest, suggesting this phytochemical is a better alternative for breast cancer treatment. Further studies in animal models could confirm the potency and usability of ISO over Rsv for targeting breast cancer, potentially posing an alternative candidate for improved therapy in the near future.

P4791Performance of the HAS-BLED, ATRIA, and PRECISE-DAPT Bleeding Risk Scores in Atrial Fibrillation Patients Using Antiplatelet Agents or Oral Anticoagulants

Background

Various bleeding risk scores have been proposed to assess the risk of bleeding in atrial fibrillation (AF) patients undergoing anticoagulation. PRECISE DAPT score has been developed to assess the out-of hospital bleeding risk in patients receiving dual antiplatelet therapy (DAPT). Our objective was to compare the predictive performance between the HAS-BLED (Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History or Predisposition, Labile International Normalized Ratio, Elderly, Drugs/Alcohol), ATRIA (Anticoagulation and Risk Factors in Atrial Fibrillation), and PRECISE-DAPT (Predicting Bleeding Complication in Patients Undergoing Stent Implantation and Subsequent Dual Antiplatelet therapy) score in AF patients using antiplatelet agents or anticoagulants

Methods

We recruited 1,114 consecutive AF patients (51% male; median age, 71 years) receiving antiplatelet agents or oral anticoagulants from January 2014 through December 2018. Major bleeding was defined as according to the Bleeding Academic Research Consortium (BARC) criteria (type 3 or 5: hemodynamic instability, need for transfusion, drop in hemoglobin ≥3 g, and intracranial, intraocular or fatal bleeding). The performance of risk scores were assessed by C-statistic.

Results

Bleeding events occurred in 135 patients (12.1%) during 30 days, and 72 patients (6.5%) from 30 days till 1-year follow-up. Based on the C-statistic, PRECISE-DAPT score (AUC: 0.72, 95% CI: 0.69–0.75) had a good performance, significantly better than HAS-BLED (AUC: 0.64, 95% CI: 0.61–0.67) (p=0.008) or ATRIA scores (AUC: 0.57, 95% CI: 0.54–0.60) (p<0.001) for 30-days bleeding prediction. Also, PRECISE-DAPT score had a good C-statistic (AUC: 0.72, 95% CI: 0.69–0.75) for 1-year bleeding events compared with HAS-BLED (AUC: 0.64, 95% CI: 0.60–0.67) (p=0.02) or ATRIA (AUC: 0.61, 95% CI: 0.58–0.65) (p=0.01).

ROC curve for bleeding

Conclusions

The PRECISE-DAPT score has been used for assessing bleeding events during DAPT. Also, the PRECISE-DAPT score predicted bleedings better than HAS-BLED or ATRIA scores in AF patients. So, the PRECISE-DAPT score may be considered as bleeding risk score during DAPT or oral anticoagulation in clinical practice.

P4776Age-dependent anti-thrombotic therapy for atrial fibrillation patients with intermediate risk (CHA2DS2-VASc Score of 1 or 2) of ischemic stroke

Background

Although older age is one of the most important risk factor for stroke in atrial fibrillation (AF), it is unclear whether oral anticoagulants are beneficial for AF patients with intermediate CHA2DS2-VASc score (1 for male or 2 for female) according to age threshold. We sought to investigate the effect of age-dependent antithrombotic therapy for ischemic stroke in Korean intermediate risk AF patients.

Methods

We enrolled 29,592 patients (males with CHA2DS2-VASc score of 1 and females with CHA2DS2-VASc score of 2) using the Korean National Health Insurance Service database. The clinical endpoint was the occurrence of ischemic stroke. The propensity score matching method was used to balance covariates across treated and untreated patients.

Results

Treated male AF patients were 6,570 (67.1%) with age <55 years, 7,115 (70.9%) with 55–64 years and 6,470 (68.3%) with 65–74 years in each age risk criterion. Also, treated female AF patients were 3,156 (71.3%) with age <55 years, 2,838 (71.0%) with 55–64 years and 3,440 (72.6%) with 65–74 years in each age risk criterion. Among male and female patients (age <55 years and 55–64 years) with 1 risk factor, an annual ischemic stroke rate was not significantly different between treated and untreated patients at full follow-up. However, treated AF patients who are in age 65–74 year without other risk factor had a much lower annual risk of ischemic stroke [(1.05%/year (male) and 1.04%/year (female)] compared with untreated patients [(1.77%/year (male) (p<0.026) and 1.86%/year (female) (p<0.041).

Conclusions

Age is an important predictor in determining the risk of ischemic stroke in AF patients with intermediate CHA2DS2-VASc scores (1 for male or 2 for female). We suggest that the benefit of anti-thrombotic therapy for intermediate risk AF patients depends on age threshold.

P5661Validation of CHA2DS2-VA score (excluding female sex) in non-valvular atrial fibrillation patients: a nationwide population-based study

Background

Sex category (Sc, ie, female sex) confers 1 point on CHA2DS2-VASc score. So, no woman with atrial fibrillation (AF) can have a CHA2DS2-VASc score of 0. This study aimed to compare CHA2DS2-VA (excluding female sex) and CHA2DS2-VASc score in Korean AF patients.

Methods

Using the Korean National Health Insurance Service database, we analyzed the risk of ischemic stroke in non-valvular AF patients between 2013 and 2017. The predictive value of the CHA2DS2-VA and CHA2DS2-VASc scores for ischemic stroke was evaluated by c-statistic difference and net reclassification improvement (NRI). The propensity score matching method was used to balance covariates across male and female AF patients.

Results

A total of 182,133 patients with AF (49.2% women) were included to this study. The adjusted incidence rate (IR) of ischemic stroke was not significantly different between males and females (0.89%/y and 0.90%/y, respectively, p=0.411) in low-risk patients without risk factor. Also, no sex difference was found in high-risk patients with above 2 risk factors for ischemic stroke (4.46%/y for male and 4.49%/y for male, p=0.498). In c-statistic analysis for ischemic stroke, there was no significant difference between the CHA2DS2-VA and CHA2DS2-VASc scores (AUC 0.662 vs. 0.664, z=1.572, p=0.116). When compared with CHA2DS2-VASc score, CHA2DS2-VA score was not significantly inferior in net reclassification improvement (NRI 0.031, 95% CI 0.002–0.037, p=0.118) for ischemic stroke.

C-statistics

Conclusions

In Korean AF patients, the CHA2DS2-VA score excluding female sex is a useful risk scoring system for ischemic stroke.

The impact of social media on citation rates in coloproctology

AIM

This study aimed to investigate the association between Twitter exposure and the number of citations for coloproctology articles.

METHOD

Original articles from journals using Twitter between June 2015 and May 2016 were evaluated for the following characteristics: publishing journal; article subject; study design; nationality, speciality and affiliation of the author(s); and reference on Twitter. Citation data for these articles were retrieved from Google Scholar (https://scholar.google.com) in January 2018. We performed a univariate analysis using these data followed by a multivariate, logistic regression analysis to search for factors associated with a high citation level, which was defined as accrual of more than five citations.

RESULTS

Out of six coloproctology journals listed on the InCites JCR database, three (Diseases of the Colon & Rectum, Colorectal Disease and Techniques in Coloproctology) used Twitter, where 200 (49.5%) out of a total of 404 articles had been featured. Citation rates of articles that featured on Twitter were significantly higher than those that did not (11.4 ± 9.2 vs 4.1 ± 3.1, P < 0.001). In multivariate analysis, Twitter exposure (OR 8.6, P = 0.001), European Union nationality (OR 2.4, P = 0.004), Colorectal Disease journal (OR 3.3, P = 0.005) and systematic review articles (OR 3.4, P = 0.009) were associated with higher citation levels.

CONCLUSION

Article exposure on Twitter was strongly associated with a high citation level. Medical communities should encourage journals as well as physicians to actively utilize social media to expedite the spread of new ideas and ultimately benefit medical society as a whole.

The Tingathe Surge: a multi-strategy approach to accelerate HIV case finding in Malawi

Setting

Nineteen health facilities in rural, southeastern Malawi.

Objective

To describe the implementation and results of a 6-week intervention to accelerate human immunodeficiency virus (HIV) case finding.

Design

Six HIV testing strategies were simultaneously implemented. Routinely collected data from Ministry of Health registers were used to determine the number of HIV tests performed and of new cases identified. The weekly averages of the total number of tests and new cases before and during the intervention were compared. Testing by age group and sex was described. The percentage yield of new cases was compared by testing strategy.

Results

Of 29 703 HIV tests conducted, 1106 (3.7%) were positive. Of the total number of persons tested, 69.5% were women and 75.5% were aged >15 years. The yield of positive test results was 3.5% among women, 4.3% among men, 4.4% among those aged >15 years and 1.5% among those aged ⩽15 years. The average weekly number of tests increased 106.7% from 3337 to 6896 (P = 0.002). The average weekly number of positive cases identified increased 51.9% from 158 to 240 (P = 0.017). The testing strategy with the highest yield resulted in a 6.0% yield; the lowest was 1.3%. The yield for all strategies, except one, was highest in adult men.

Conclusion

A multi-strategy approach to HIV testing and counseling can be an effective means of accelerating HIV case finding.

Highly Efficient and Practical N-Heterocyclic Carbene Organocatalyzed Chemoselective N1/C3-Functionalization of Isatins with Green Chemistry Principles

Ecofriendly N-heterocyclic carbene (NHC) organocatalysis can control the N₁-functionalization (aza-Michael addition) and C₃-functionalization (Morita-Baylis-Hillman reaction, MBH) of isatins in the absence of (1) a protecting group, (2) a stoichiometric reagent, and (3) heat energy. The challengeable N₁-functionalization of N-unsubstituted isatins into N-substituted (NS) isatins was realized through 10 mol % NHC and 10 mol % 1,8-diazabicyclo[5.4.0]undec-7-ene catalysts within 10 min with up to 98% isolation yield. The subsequent MBH adducts of as-synthesized NS-isatins (N₁/C₃-functionalization) was perfectly acquired in 10 mol % NHC and 10 mol % 1,4-diazabicyclo[2.2.2]octane catalysis within 30 min with superiority to C₃/N₁-functionalization (MBH/aza-Michael). For guiding the application to a versatile druggable isatin library, the NHC catalysis was compared with reported functionalization of isatins in view of green chemistry principles including solvent scoring of ACS GCI pharmaceutical roundtable, E-factor, atom economy, and so on.

Pseudorapidity Dependence of Particle Production and Elliptic Flow in Asymmetric Nuclear Collisions of p+Al, p+Au, d+Au, and ^{3}He+Au at sqrt[s_{NN}]=200 GeV

Asymmetric nuclear collisions of p+Al, p+Au, d+Au, and ^{3}He+Au at sqrt[s_{NN}]=200  GeV provide an excellent laboratory for understanding particle production, as well as exploring interactions among these particles after their initial creation in the collision. We present measurements of charged hadron production dN_{ch}/dη in all such collision systems over a broad pseudorapidity range and as a function of collision multiplicity. A simple wounded quark model is remarkably successful at describing the full data set. We also measure the elliptic flow v_{2} over a similarly broad pseudorapidity range. These measurements provide key constraints on models of particle emission and their translation into flow.

Kidney Transplantation Using Expanded-Criteria Deceased Donors: A Comparison With Ideal Deceased Donors and Non-Expanded-Criteria Deceased Donors

PURPOSE

The use of expanded-criteria deceased-donor (ECD) kidneys must be evaluated within the objective perspective of critical organ shortage and graft function and survival. In this study, we aimed to compare the clinical outcomes of ECD reliance with concurrent use of ideal-criteria deceased donors (IDDs) and non-ECDs in adult renal transplantation.

METHODS

Between February 2000 and December 2015, we analyzed 405 deceased-donor renal transplants, specifically 129 grafts (31.9%) from ECDs, 233 grafts (57.5%) from non-ECDs, and 43 grafts (10.6%) from IDDs. ECDs were classified according to the United Network for Organ Sharing guidelines, while an IDD was defined as a younger person (10-39 years of age) with no medical risk factors who died from a traumatic head injury. Donor and recipient risk factors were separately analyzed and correlated with recipient graft function, and survival was evaluated.

RESULTS

ECDs were older (56.8 ± 6.3 years); showed increased incidence of hypertension, diabetes, and cerebrovascular brain death; and had a higher pre-retrieval serum creatinine level than the other groups. ECD kidney recipients were also older (50.6 ± 9.8 years), had a shorter waiting time (P = .031), and demonstrated a low frequency of re-transplantation (P = .028). Long-term renal function followed longitudinally was lower in ECD kidney recipients until five years after transplantation, while the glomerular filtration rate (GFR) level at 7 and 10 years did not differ significantly among the groups (P = .074 and .262, respectively). There were no significant differences in terms of graft survival (P = .394) or patient survival (P = .737) among the groups.

CONCLUSIONS

Although the long-term renal function followed longitudinally was lower in ECD kidney recipients, the use of renal grafts from ECDs is an acceptable method to resolve the disparity of critical organ shortage. However, the classification of the high-risk group should be updated with consideration given to differences in regional characteristics.

Effects of visual cue and cognitive motor tasks on standing postural control following a chronic stroke

[Purpose] The objective of the study was to examine the effects of visual cue and cognitive motor tasks on quiet standing posture center of pressure (COP) and the weight loads to the paretic and non-paretic legs in chronic stroke patients. [Subjects and Methods] Twenty chronic stroke patients were included in the study. COP total distance, sway velocity, and the weight loads to the paretic and non-paretic legs of the participants were measured while they performed a visual cue task, cognitive motor task, and dual task. The parameters were compared using a repeated three-way analysis of variance. [Results] When the visual cue was provided, the COP total distance and sway velocity were significantly reduced compared with when no visual cue was given. When the cognitive motor task was performed, the COP total distance and sway velocity decreased significantly compared to when the task was not performed. [Conclusion] These findings suggest that visual cue and cognitive motor tasks could be used as parts of a rehabilitative training program to improve the control of standing in chronic stroke patients. In addition, visual cues can be used as an intervention to train the paretic leg of stroke patients.

The relationship between clinical characteristics including presence of exposed lesions and health-related quality of life (HRQoL) in patients with psoriasis: analysis from the nationwide epidemiologic study for psoriasis in Korea (EPI-PSODE study)

BACKGROUND

Psychological aspect and quality of life should be considered in treating patients with psoriasis.

OBJECTIVE

We sought to ascertain which clinical characteristics including presence of exposed lesions are associated with impairment of health-related quality of life (HRQoL) in patients with psoriasis.

METHODS

The EPI-PSODE study was a nationwide, multicenter, cross-sectional study conducted in Korea that included 1260 adult patients with psoriasis. In addition to clinical characteristics including presence of exposed lesions, data were collected using the Psoriatic Arthritis (PsA) Screening and Evaluation (PASE), Dermatology Life Quality Index (DLQI), MOS 36-Item Short-Form Health Survey (SF-36), Work Productivity and Activity Impairment Questionnaire Psoriasis (WPAI: PSO) and Medication Satisfaction Questionnaire (MSQ).

RESULTS

Patients with a DLQI score > 5 (n = 990) were younger, had an earlier onset of psoriasis, scored higher on the Psoriasis Area and Severity Index (PASI), had higher body surface area (BSA) and had higher PASE scores than patients with DLQI ≤ 5 (n = 266). The group of patients with exposed lesions (n = 871) were younger and male predominance, earlier onset of psoriasis, longer disease duration, higher PASI/BSA score and a higher proportion with drinking and smoking history each than the group of patients without exposed lesions (n = 389). Presence of exposed lesions negatively influenced DLQI, 36-Item Short-Form Health Survey (SF-36) (mental component), presenteeism, total work productivity impairment and total activity impairment in the WPAI: PSO. In multiple regression model, PASI score was the only variable which was significantly associated with all HRQoL measures. Presence of exposed lesions was a significant factor affecting DLQI and SF-36 (mental).

CONCLUSION

The presence of exposed lesions has a negative impact on quality of life, mental health and work productivity. Therefore, effective treatments are particularly needed for psoriasis patients with exposed lesions.

Measurements of Multiparticle Correlations in d+Au Collisions at 200, 62.4, 39, and 19.6 GeV and p+Au Collisions at 200 GeV and Implications for Collective Behavior

Recently, multiparticle-correlation measurements of relativistic p/d/^{3}He+Au, p+Pb, and even p+p collisions show surprising collective signatures. Here, we present beam-energy-scan measurements of two-, four-, and six-particle angular correlations in d+Au collisions at sqrt[s_{NN}]=200, 62.4, 39, and 19.6 GeV. We also present measurements of two- and four-particle angular correlations in p+Au collisions at sqrt[s_{NN}]=200  GeV. We find the four-particle cumulant to be real valued for d+Au collisions at all four energies. We also find that the four-particle cumulant in p+Au has the opposite sign as that in d+Au. Further, we find that the six-particle cumulant agrees with the four-particle cumulant in d+Au collisions at 200 GeV, indicating that nonflow effects are subdominant. These observations provide strong evidence that the correlations originate from the initial geometric configuration, which is then translated into the momentum distribution for all particles, commonly referred to as collectivity.

Non-communicable diseases and risk of tuberculosis in Korea

BACKGROUND

It is possible that the increasing burden of non-communicable diseases (NCDs) and their risk factors are an obstacle to the reduction of tuberculosis (TB) incidence in the Republic of Korea.

OBJECTIVE

To estimate population-attributable fractions (PAF) of NCDs and their risk factors related to TB in Korea.

DESIGN

The prevalence of diabetes mellitus (DM), current smoking, heavy drinking and undernutrition was estimated from the Korean National Health and Nutrition Examination Survey (KNHANES) conducted in 2013. Estimates of effect for risk factors were obtained from meta-analyses. The PAF was calculated based on these data.

RESULTS

The PAF of DM, current smoking, heavy drinking and undernutrition was 20.0%, 18.8%, 18.4% and 9.6%, respectively. Current smoking has the highest PAF among men, while undernutrition was the highest among women. Current smoking and heavy drinking were significantly attributed to TB among the younger population, while DM was the most common responsible factor among the older population. Major risk factors such as current smoking and DM were more prevalent in the lower income level population.

CONCLUSION

NCDs and their risk factors play an important role at the population level in TB epidemics in Korea. Collaborative TB and NCD activities in TB control should therefore be intensified.

Burden of disease and risk factors for death among children treated for tuberculosis in Malawi

SETTING

Tuberculosis (TB) is a leading cause of childhood death. Patient-level data on pediatric TB in Malawi that can be used to guide programmatic interventions are limited.

OBJECTIVE

To describe pediatric TB case burden, disease patterns, treatment outcomes, and risk factors for death and poor outcome.

DESIGN

We conducted a retrospective cohort study utilizing routine data. Odds ratios (ORs) for factors associated with poor outcome and death were calculated using generalized estimating equations.

RESULTS

Children represented 8% (371/4642) of TB diagnoses. The median age was 7 years (interquartile range 2.8-11); 32.8% (113/345) were human immunodeficiency virus (HIV) infected. Of these, 54.0% were on antiretroviral therapy (ART) at the time of anti-tuberculosis treatment (ATT) initiation, 21.2% started ART during ATT, and 24.8% had no documented ART. The treatment success rate was 77.3% (11.2% cured, 66.1% completed treatment), with 22.7% experiencing poor outcomes (9.5% died, 13.2% were lost to follow-up). Being on ART at the time of ATT initiation was associated with increased odds of death compared to beginning ART during treatment (adjusted OR 2.75, 95%CI 1.27-5.96).

CONCLUSION

Children represent a small proportion of diagnosed TB cases and experience poor outcomes. Higher odds of death among children already on ART raises concerns over the management of these children. Further discussion of and research into pediatric-specific strategies is required to improve case finding and outcomes.

Nuclear Dependence of the Transverse-Single-Spin Asymmetry for Forward Neutron Production in Polarized p+A Collisions at sqrt[s_{NN}]=200 GeV

During 2015, the Relativistic Heavy Ion Collider (RHIC) provided collisions of transversely polarized protons with Au and Al nuclei for the first time, enabling the exploration of transverse-single-spin asymmetries with heavy nuclei. Large single-spin asymmetries in very forward neutron production have been previously observed in transversely polarized p+p collisions at RHIC, and the existing theoretical framework that was successful in describing the single-spin asymmetry in p+p collisions predicts only a moderate atomic-mass-number (A) dependence. In contrast, the asymmetries observed at RHIC in p+A collisions showed a surprisingly strong A dependence in inclusive forward neutron production. The observed asymmetry in p+Al collisions is much smaller, while the asymmetry in p+Au collisions is a factor of 3 larger in absolute value and of opposite sign. The interplay of different neutron production mechanisms is discussed as a possible explanation of the observed A dependence.