Test of Lepton-Flavor Universality in B→K^{*}ℓ^{+}ℓ^{-} Decays at Belle

We present a measurement of R_{K^{*}}, the branching fraction ratio B(B→K^{*}μ^{+}μ^{-})/B(B→K^{*}e^{+}e^{-}), for both charged and neutral B mesons. The ratio for the charged case R_{K^{*+}} is the first measurement ever performed. In addition, we report absolute branching fractions for the individual modes in bins of the squared dilepton invariant mass q^{2}. The analysis is based on a data sample of 711  fb^{-1}, containing 772×10^{6}  BB[over ¯] events, recorded at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. The obtained results are consistent with standard model expectations.

A compact and stable incidence-plane-rotating second harmonics detector

We describe a compact and stable setup for detecting the optical second harmonics, in which the incident plane rotates with respect to the sample. The setup is composed of rotating Fresnel rhomb optics and a femtosecond ytterbium-doped fiber laser source operating at the repetition frequency of 10 MHz. The setup including the laser source occupies an area of 1 m² and is stable so that the intensity fluctuation of the laser harmonics can be less than 0.2% for 4 h. We present the isotropic harmonic signal of a gold mirror of 0.5 pW and demonstrate the integrity and sensitivity of the setup. We also show the polarization-dependent six-fold pattern of the harmonics of a few-layer WSe₂, from which we infer the degree of local-field effects. Finally, we describe the extensibility of the setup to investigate the samples in various conditions such as cryogenic, strained, ultrafast non-equilibrium, and high magnetic fields.

Evidence for X(3872)→J/ψπ^{+}π^{-} Produced in Single-Tag Two-Photon Interactions

We report the first evidence for X(3872) production in two-photon interactions by tagging either the electron or the positron in the final state, exploring the highly virtual photon region. The search is performed in e^{+}e^{-}→e^{+}e^{-}J/ψπ^{+}π^{-}, using 825  fb^{-1} of data collected by the Belle detector operated at the KEKB e^{+}e^{-} collider. We observe three X(3872) candidates, where the expected background is 0.11±0.10 events, with a significance of 3.2σ. We obtain an estimated value for Γ[over ˜]_{γγ}B(X(3872)→J/ψπ^{+}π^{-}) assuming the Q^{2} dependence predicted by a cc[over ¯] meson model, where -Q^{2} is the invariant mass squared of the virtual photon. No X(3915)→J/ψπ^{+}π^{-} candidates are found.

Risk factors for local recurrence and long term survival after minimally invasive intersphincteric resection for very low rectal cancer: Multivariate analysis in 161 patients

INTRODUCTION

Intersphincteric resection (ISR) is the ultimate anal-sparing technique as an alternative to abdominoperineal resection in selected patients. Oncological safety is still debated. This study analyses long-term oncological results and evaluates risk factors for local recurrence (LR) and overall survival (OS) after minimally-invasive ISR.

MATERIALS AND METHODS

Retrospective single-center data were collected from a prospectively maintained colorectal database. A total of 161 patients underwent ISR between 2008 and 2018. OS and local recurrence-free survival (LRFS) were assessed using Kaplan-Meier analysis (log-rank test). Risk factors for OS and LRFS were assessed with Cox-regression analysis.

RESULTS

Median follow-up was 55 months. LR occurred in 18 patients. OS and LRFS rates at 1, 3, and 5 years were 96%, 91%, and 80% and 96%, 89%, and 87%, respectively. Tumor size (p = 0.035) and clinical T-stage (p = 0.029) were risk factors for LRFS on univariate analysis. On multivariate analysis, tumor size (HR 2.546 (95% CI: 0.976-6.637); p = 0.056) and clinical T-stage (HR 3.296 (95% CI: 0.941-11.549); p = 0.062) were not significant. Preoperative CEA (p < 0.001), pathological T-stage (p = 0.033), pathological N-stage (p = 0.016) and adjuvant treatment (p = 0.008) were prognostic factors for OS on univariate analysis. Preoperative CEA (HR 4.453 (95% CI: 2.015-9.838); p < 0.001) was a prognostic factor on multivariate analysis.

CONCLUSIONS

This study confirms the oncological safety of minimally-invasive ISR for locally advanced low-lying rectal tumors when performed in experienced centers. Despite not a risk factor for LR, tumor size and, locally advanced T-stage with anterior involvement should be carefully evaluated for optimal surgical strategy. Preoperative CEA is a prognostic factor for OS.

Developing a predictive model for distinguishing invasive nail unit melanoma from nail unit melanoma in situ

BACKGROUND

Clinical information that distinguishes invasive nail unit melanoma from nail unit melanoma in situ before surgery would aid physicians in the decision-making process and estimating prognosis. However, limited information is available on the detailed demographic and dermoscopic features of invasive nail unit melanoma and nail unit melanoma in situ for differential diagnosis.

OBJECTIVE

This study aimed to investigate the demographic data and dermoscopic features of invasive nail unit melanoma and nail unit melanoma in situ and establish a predictive model for differentiating these two forms of nail unit melanoma.

METHODS

A retrospective observational study of ninety-seven patients diagnosed with nail unit melanoma (59 in situ and 38 invasive cases) in four healthcare centres in South Korea (three tertiary referral hospitals and one second referral hospital) from March 2014 to December 2019.

RESULTS

A multivariable analysis revealed that ulcer (odds ratio = 21.6, confidence interval = 2.1-219.8, P = 0.009), total melanonychia (odds ratio = 17.6, confidence interval = 3.0-104.0, P = 0.002), nail plate destruction (odds ratio = 10.9, confidence interval = 2.0-59.4, P = 0.006) and polychromia (odds ratio = 5.3, confidence interval = 1.36-20.57, P = 0.016) were distinctive dermoscopic features of invasive nail unit melanoma. A predictive model with scores ranging from 0 to 6 points demonstrated a reliable diagnostic value (C-statistic = 0.902) in differentiating invasive nail unit melanoma from nail unit melanoma in situ.

CONCLUSIONS

Invasive nail unit melanoma and nail unit melanoma in situ have different dermoscopic features. A predictive model based on morphologic dermoscopic features could aid in differentiating invasive nail unit melanoma from nail unit melanoma in situ.

Search for Axionlike Particles Produced in e^{+}e^{-} Collisions at Belle II

We present a search for the direct production of a light pseudoscalar a decaying into two photons with the Belle II detector at the SuperKEKB collider. We search for the process e^{+}e^{-}→γa, a→γγ in the mass range 0.2<m_{a}<9.7  GeV/c^{2} using data corresponding to an integrated luminosity of (445±3)  pb^{-1}. Light pseudoscalars interacting predominantly with standard model gauge bosons (so-called axionlike particles or ALPs) are frequently postulated in extensions of the standard model. We find no evidence for ALPs and set 95% confidence level upper limits on the coupling strength g_{aγγ} of ALPs to photons at the level of 10^{-3}  GeV^{-1}. The limits are the most restrictive to date for 0.2<m_{a}<1  GeV/c^{2}.

Frontal plane dynamics of the centre of mass during quadrupedal locomotion on a split-belt treadmill

Our previous study of cat locomotion demonstrated that lateral displacements of the centre of mass (COM) were strikingly similar to those of human walking and resembled the behaviour of an inverted pendulum (Park et al. 2019 J. Exp. Biol.222, 14. (doi:10.1242/jeb.198648)). Here, we tested the hypothesis that frontal plane dynamics of quadrupedal locomotion are consistent with an inverted pendulum model. We developed a simple mathematical model of balance control in the frontal plane based on an inverted pendulum and compared model behaviour with that of four cats locomoting on a split-belt treadmill. The model accurately reproduced the lateral oscillations of cats' COM vertical projection. We inferred the effects of experimental perturbations on the limits of dynamic stability using data from different split-belt speed ratios with and without ipsilateral paw anaesthesia. We found that the effect of paw anaesthesia could be explained by the induced bias in the perceived position of the COM, and the magnitude of this bias depends on the belt speed difference. Altogether, our findings suggest that the balance control system is actively involved in cat locomotion to provide dynamic stability in the frontal plane, and that paw cutaneous receptors contribute to the representation of the COM position in the nervous system.

Conducting a national burden of disease study in South Korea: from past to present

South Korea has been measuring its own burden of disease since the early 2000s and has developed a methodology for its calculation. Since 2012, South Korea has been carrying out disease burden research through the Research and Development Project, supported by the Ministry of Health and Welfare. Because the Korean health insurance system covers the entire population of the country, the Korean National Burden of Disease (KNBD) study is based on individual claims data. Disease prevalence, incidence, and mortality rates, which are the epidemiologic indicators used to calculate burden of disease, are based on actual data, and the incidence-based approach is used for Years Lived with disability (YLD), Years of Life Lost (YLL), and Disability Adjusted Life Year (DALY). The KNBD study is conducted for 260 diseases and injuries and subdivided into sub-national levels. Disability weights (DW) are calculated to reflect the sociocultural characteristics of a disease. For cause-specific DWs, we conducted a self-administered web-based survey for medical doctors and students. Using a ranking method, we calculated cause-specific DWs. For this reason, KNBD study results cannot be directly compared with GBD results.

The major findings of the KNBD study are as follows. In Korea, the DALY rate (per 100,000 people) steadily increased for all income levels. The higher the income, the lower the burden of disease; low-income people had a higher burden of disease than high-income people. However, thyroid cancer, refraction and accommodation disorders had a high burden of disease in the high-income group. Growth in the YLD rate was faster than in the YLL rate. In 2016 the leading causes of disease burden were diabetes mellitus, low back pain, and chronic obstructive pulmonary disease.

We will present South Korea's disease burden calculation methodology and its results and share the efforts to calculate disease burden in other countries.

Variation in training requirements within general surgery: comparison of 23 countries

Background

Many differences exist in postgraduate surgical training programmes worldwide. The aim of this study was to provide an overview of the training requirements in general surgery across 23 different countries.

Methods

A collaborator affiliated with each country collected data from the country's official training body website, where possible. The information collected included: management, teaching, academic and operative competencies, mandatory courses, years of postgraduate training (inclusive of intern years), working‐hours regulations, selection process into training and formal examination.

Results

Countries included were Australia, Belgium, Canada, Colombia, Denmark, Germany, Greece, Guatemala, India, Ireland, Italy, Kuwait, the Netherlands, New Zealand, Russia, Saudi Arabia, South Africa, South Korea, Sweden, Switzerland, UK, USA and Zambia. Frameworks for defining the outcomes of surgical training have been defined nationally in some countries, with some similarities to those in the UK and Ireland. However, some training programmes remain heterogeneous with regional variation, including those in many European countries. Some countries outline minimum operative case requirement (range 60–1600), mandatory courses, or operative, academic or management competencies. The length of postgraduate training ranges from 4 to 10 years. The maximum hours worked per week ranges from 38 to 88 h, but with no limit in some countries.

Conclusion

Countries have specific and often differing requirements of their medical profession. Equivalence in training is granted on political agreements, not healthcare need or competencies acquired during training.

AB0770 DESCRIBING A COHORT OF PATIENTS WITH PSORIATIC ARTHRITIS ACCORDING TO THE BODY MASS INDEX: EXPERIENCE IN A JOINT RHEUMATOLOGY-DERMATOLOGY CLINIC

Background:

Obesity is a predictor for the development of psoriatic arthritis (PsA) with a negative prognostic impact.

Objectives:

We aimed to describe and characterize patients with PsA according to the Body Mass Index (BMI) in a joint Rheumatology-Dermatology unit (PAIDER).

Methods:

We retrospectively reviewed patients diagnosed with PsA according to CASPAR criteria visited between May 2012 and May 2019 at the PAIDER clinic of our center. Data on demographic and anthropometric features, serologic findings, source of referral, cardiovascular risk factors and biological treatment were collected from clinical records. Patients were classified according to the WHO International Classification of nutritional status in normal weight (BMI 18.5-24.9 Kg/m2), overweight (BMI 25-29.9 Kg/m2) and obesity (BMI≥30 Kg/m2). A descriptive analysis was performed, and the differences between groups were evaluated using Chi2, T-Student and ANOVA tests. P-values <0.05 were accepted as significant.

Results:

During the study period 393 patients (50.6% women) with a mean age of 52.47 ± 13.21 years were evaluated. Baseline characteristics are shown in table 1.

Table 1.Baseline characteristicsTotaln=393Female, n (%)199 (50,6)Age, yrs, mean ±SD52,47 (13,21)Source of referral, n (%) Dermatology117 (29,8) Rheumatology219 (55,7) Primary Care and Others22 (5,6)Smoker, n (%)97 (25,8)High Blood Pressure (HBP), n (%)106 (27,7)Diabetes, n (%)48 (12,5)Hypercholesterolemia, n (%)98 (25,8)Hyperuricemia, n (%)32 (8,6)HLA-B27 positive, n (%)68 (21,6)BMI, Kg/m2, mean ±SD28,15 (5,87)Biological treatment, n (%)166 (43,2)

The mean BMI was 28.15 ± 5.87 kg/m2. 112 patients (32%) were overweight with a mean BMI of 27.46 ± 1.55 kg/m2and 118 patients (34%) were obese with a mean BMI of 34.42 ± 5.08 kg/m2. Of the obese patients, 80 (67.8%) had obesity grade 1, 28 (23.7%) grade 2 and 10 (8.5%) grade 3.

Characteristics of the patients according to BMI categories are shown in Table 2.

Table 2.Characteristics according to BMINormal weightn= 118Overweightn= 112Obesityn=118P valueFemale, n (%)66 (55,9)52 (46,4)62 (52,5)nsAge, yrs, mean ±SD47,92 (14,08)54,71 (11,75)54,48 (11,54)<0,001Source of referral, n (%)Ns Dermatology35 (33,7)37 (35,2)34 (30,9) Rheumatology63 (60,6)61 (58,1)70 (63,6) Primary Care and Others6 (5,8)7 (6,7)6 (5,5)Smoker, n (%)37 (33)23 (21,1)31 (26,7)nsHigh Blood Pressure (HBP), n (%)12 (10,5)37 (34,3)41 (35)<0,001Diabetes, n (%)7 (6)9 (8,3)30 (25,6)<0,001Hypercholesterolemia, n (%)19 (17)24 (22,2)45 (38,5)0,001Hyperuricemia, n (%)5 (4,4)7 (6,8)19 (16,7)0,004HLA-B27, n (%)27 (28,7)17 (17,9)13 (12,6)0,016BMI, Kg/m2, media ±DE22,58 (1,78)27,46 (1,55)34,42 (5,08)-Biological treatment, n (%)47 (41,2)45 (40,9)66 (55,9)0,032

We observed that mean age was significantly higher in obese patients (p <0.001), as well as the prevalence of cardiovascular risk factors such as HBP (p <0.001), Diabetes (p <0.001), dyslipidemia (p = 0.001) and hyperuricemia (p = 0.004). Obese patients also received more biological therapy (p=0.032). A higher prevalence of HLA-B27 was observed in patients with normal weight (p=0.016). No differences were found according to BMI regarding gender and source of referral.

Conclusion:

- Almost 70% of patients with PsA visited in the PAIDER clinic of our center have a BMI above normal and more than a third of them are obese, mostly grade 1.

- In our joint clinic there are no differences in BMI regarding the source of referral of the patients.

- Patients with obesity are older, have more cardiovascular comorbidities and receive more biological treatment significantly, which increases the complexity of their management and worsens the prognosis.

Disclosure of Interests:

Andrea García-Guillén: None declared, Ana Laiz: None declared, Anna Lopez-Ferrer: None declared, HyeSang Park: None declared, Patricia Moya: None declared, Berta Magallares: None declared, Ivan Castellví Consultant of: Boehringer Ingelheim, Actelion, Kern Pharma, Speakers bureau: Boehringer Ingelheim, Actelion, Bristol-Myers Squibb, Roche, Ana Milena Millán Arciniegas: None declared, Cesar Díaz-Torné: None declared, Sicylle Jeria: None declared, Hector Corominas: None declared

AB0997 IS HEIGHT ADJUSTMENT NECESSARY IN PEDIATRIC DENSITOMETRY IN ALL CHILDREN?

Background:

The current guidelines of the International Society for Clinical Densitometry (1) recommend that in children with linear growth or maturational delay, Z score results should be adjusted. Height for age Z score (HAZ) adjustment is valid and can be calculated using the formula the formula proposed by Zemmel et al(2).

It is possible that pediatric populations without linear growth or maturational delay, also benefit from HAZ, to prevent bone size from influencing the final Z score.

Objectives:

To evaluate Z score variability adjusted and without adjusting for height for age.

Methods:

We analysed data from densitometry performed on patients 2-20 years of age, from 2016 to 2018, assessed in the pediatric rheumatology office of our hospital for presenting risk factors for low bone mass/osteoporosis. The HAZ was calculated according to Zemel’s formula.

Results:

Data from 103 patients are presented. Its characteristics are summarized in Table 1

Table 1.Mean age9,8 yearsFemale52,4%Height Percentil ≤ 36,8%Height Percentil ≥ 974,9%LBM (Z score ≤ -2) spine8,2%LBM HAZ spine6,4%LBM whole body10,5%LBM HAZ whole body7,2%

The table shows that the proportion of patients with BMD decreases in both the spine region and the whole body when adjusting for HAZ.

When evaluating the relationship between densitometric measurements we found that spine Z score (ZsS) and whole body Z score (ZsWB) had a correlation coefficient of 0,73 (p<0,001). There were no differences between their averages (p=0,170).

At the LBM cut-off point (Z score ≤ -2) there were discrepancies in 7%, where 5% presented LBM in ZsWB but not in ZsS. The concordance index at this point was 0,557.

When comparing these measures with their HAZ adjusted equivalents, we observe:

Conclusion:

There are discrepancies at the LBM cut-off point depending on the HAZ adjustment.

The pediatric population without linear growth or maturational delay, can also benefit from HAZ adjustment, especially those with high height percentiles in which their size can hide a diagnosis of LBM.

References:

[1]Weber DR, Boyce A, Gordon C, Hogler W, Kecskemethy HH, Misra M, et al. The Utility of DXA Assessment at the Forearm, Proximal Femur, and Lateral Distal Femur, and Vertebral Fracture Assessment in the Pediatric Population: 2019 ISCD Official Position. Journal of clinical densitometry: the official journal of the International Society for Clinical Densitometry. 2019;22(4):567-89.

[2]Zemel BS, Leonard MB, Kelly A, Lappe JM, Gilsanz V, Oberfield S, et al. Height adjustment in assessing dual energy x-ray absorptiometry measurements of bone mass and density in children. The Journal of clinical endocrinology and metabolism. 2010;95(3):1265-73.

Disclosure of Interests:

None declared