Precision Measurement of the n=2 Triplet P J=1 to J=0 Fine Structure of Atomic Helium Using Frequency-Offset Separated Oscillatory Fields

Increasing accuracy of the theory and experiment of the n=2 ^{3}P fine structure of helium has allowed for increasingly precise tests of quantum electrodynamics (QED), determinations of the fine-structure constant α, and limitations on possible beyond the standard model physics. Here we present a 2 ppb measurement of the J=1 to J=0 interval. The measurement is performed using frequency-offset separated-oscillatory fields. Our result of 29 616 955 018(60) Hz represents a landmark for helium fine-structure measurements, and, for the first time, will allow for a 1-ppb determination of the fine-structure constant when QED theory for the interval is improved.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Tislelizumab versus chemotherapy as second-line treatment for European and North American patients with advanced or metastatic esophageal squamous cell carcinoma: a subgroup analysis of the randomized phase III RATIONALE-302 study

BACKGROUND

The phase III RATIONALE-302 study evaluated tislelizumab, an anti-programmed cell death protein 1 antibody, as second-line (2L) treatment for advanced/metastatic esophageal squamous cell carcinoma (ESCC). This prespecified exploratory analysis investigated outcomes in patients from Europe and North America (Europe/North America subgroup).

PATIENTS AND METHODS

Patients with tumor progression during/after first-line systemic treatment were randomized 1 : 1 to open-label tislelizumab or investigator's choice of chemotherapy (paclitaxel, docetaxel, or irinotecan).

RESULTS

The Europe/North America subgroup comprised 108 patients (tislelizumab: n = 55; chemotherapy: n = 53). Overall survival (OS) was prolonged with tislelizumab versus chemotherapy (median: 11.2 versus 6.3 months), with a hazard ratio (HR) of 0.55 [95% confidence interval (CI) 0.35-0.87]; HR was similar irrespective of programmed death-ligand 1 score [≥10%: 0.47 (95% CI 0.18-1.21); <10%: 0.55 (95% CI 0.30-1.01)]. Median progression-free survival was 2.3 versus 2.7 months with tislelizumab versus chemotherapy [HR: 0.97 (95% CI 0.64-1.47)]. Overall response rate was greater with tislelizumab (20.0%) versus chemotherapy (11.3%), with more durable response (median duration of response: 5.1 versus 2.1 months). Tislelizumab had a favorable safety profile versus chemotherapy, with fewer patients experiencing ≥grade 3 treatment-related adverse events (13.0% versus 51.0%). Those on tislelizumab experienced less deterioration in health-related quality of life, physical functioning, and/or disease- and treatment-related symptoms (i.e. fatigue, pain, and eating problems) as compared to those on chemotherapy, per the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (QLQ-C30) and QLQ-OES18 scores.

CONCLUSIONS

As a 2L therapy for advanced/metastatic ESCC, tislelizumab improved OS and had a favorable safety profile as compared to chemotherapy in European/North American ESCC patients in the randomized phase III RATIONALE-302 study.

Generalized Verrucosis on a Background of 3C Syndrome Treated With Subcutaneous IgG Supplementation

This case report describes a man in his 20s with 3C/Ritscher-Schinzel syndrome who presented to the dermatology department after developing multiple skin lesions.

Gain-of-function MYCN causes a megalencephaly-polydactyly syndrome manifesting mirror phenotypes of Feingold syndrome

MYCN, a member of the MYC proto-oncogene family, regulates cell growth and proliferation. Somatic mutations of MYCN are identified in various tumors, and germline loss-of-function variants are responsible for Feingold syndrome, characterized by microcephaly. In contrast, one megalencephalic patient with a gain-of-function variant in MYCN, p.Thr58Met, has been reported, and additional patients and pathophysiological analysis are required to establish the disease entity. Herein, we report two unrelated megalencephalic patients with polydactyly harboring MYCN variants of p.Pro60Leu and Thr58Met, along with the analysis of gain-of-function and loss-of-function Mycn mouse models. Functional analyses for MYCN-Pro60Leu and MYCN-Thr58Met revealed decreased phosphorylation at Thr58, which reduced protein degradation mediated by FBXW7 ubiquitin ligase. The gain-of-function mouse model recapitulated the human phenotypes of megalencephaly and polydactyly, while brain analyses revealed excess proliferation of intermediate neural precursors during neurogenesis, which we determined to be the pathomechanism underlying megalencephaly. Interestingly, the kidney and female reproductive tract exhibited overt morphological anomalies, possibly as a result of excess proliferation during organogenesis. In conclusion, we confirm an MYCN gain-of-function-induced megalencephaly-polydactyly syndrome, which shows a mirror phenotype of Feingold syndrome, and reveal that MYCN plays a crucial proliferative role, not only in the context of tumorigenesis, but also organogenesis.

Structure of the endosomal Commander complex linked to Ritscher-Schinzel syndrome

The Commander complex is required for endosomal recycling of diverse transmembrane cargos and is mutated in Ritscher-Schinzel syndrome. It comprises two sub-assemblies: Retriever composed of VPS35L, VPS26C, and VPS29; and the CCC complex which contains twelve subunits: COMMD1-COMMD10 and the coiled-coil domain-containing (CCDC) proteins CCDC22 and CCDC93. Combining X-ray crystallography, electron cryomicroscopy, and in silico predictions, we have assembled a complete structural model of Commander. Retriever is distantly related to the endosomal Retromer complex but has unique features preventing the shared VPS29 subunit from interacting with Retromer-associated factors. The COMMD proteins form a distinctive hetero-decameric ring stabilized by extensive interactions with CCDC22 and CCDC93. These adopt a coiled-coil structure that connects the CCC and Retriever assemblies and recruits a 16th subunit, DENND10, to form the complete Commander complex. The structure allows mapping of disease-causing mutations and reveals the molecular features required for the function of this evolutionarily conserved trafficking machinery.

Associations of fat mass index with hot flashes and lean mass index with insomnia in middle-aged women

OBJECTIVE

This cross-sectional study examined the relationship between body composition and physical and mental symptom severity in middle-aged women.

METHODS

The first-visit records of 554 women aged 40-64 years were examined. The fat mass index (FMI) and lean mass index (LMI) were defined as fat mass and lean mass divided by the height squared, respectively. The participants were divided into two groups according to their median values.

RESULTS

The only menopausal symptom with significantly different severity between the high and low FMI groups was hot flashes (HF) on the Menopausal Health-Related Quality of Life Questionnaire. The factors associated with severe HF were investigated using multiple logistic regression analysis. After adjusting, the FMI (kg/m²) was independently positively associated with severe HF (odds ratio, 1.08; 95% confidence interval, 1.02-1.15). Insomnia was the only menopausal symptom with significantly different severity between the LMI groups (defined as Athens Insomnia Scale score ≥10 points). The factors associated with moderate-to-severe insomnia were investigated using multiple logistic regression analysis. After adjusting, the LMI (kg/m²) was independently negatively associated with moderate-to-severe insomnia (odds ratio, 0.72; 95% confidence interval, 0.55-0.94).

CONCLUSIONS

The FMI was positively associated with severe HF, whereas the LMI was negatively associated with moderate-to-severe insomnia in middle-aged women.

Clinical diversity and molecular mechanism of VPS35L-associated Ritscher-Schinzel syndrome

PURPOSE

The Retriever subunit VPS35L is the third responsible gene for Ritscher-Schinzel syndrome (RSS) after WASHC5 and CCDC22. To date, only one pair of siblings have been reported and their condition was significantly more severe than typical RSS. This study aimed to understand the clinical spectrum and underlying molecular mechanism in VPS35L-associated RSS.

METHODS

We report three new patients with biallelic VPS35L variants. Biochemical and cellular analyses were performed to elucidate disease aetiology.

RESULTS

In addition to typical features of RSS, we confirmed hypercholesterolaemia, hypogammaglobulinaemia and intestinal lymphangiectasia as novel complications of VPS35L-associated RSS. The latter two complications as well as proteinuria have not been reported in patients with CCDC22 and WASHC5 variants. One patient showed a severe phenotype and the other two were milder. Cells established from patients with the milder phenotypes showed relatively higher VPS35L protein expression. Cellular analysis found VPS35L ablation decreased the cell surface level of lipoprotein receptor-related protein 1 and low-density lipoprotein receptor, resulting in reduced low-density lipoprotein cellular uptake.

CONCLUSION

VPS35L-associated RSS is a distinct clinical entity with diverse phenotype and severity, with a possible molecular mechanism of hypercholesterolaemia. These findings provide new insight into the essential and distinctive role of Retriever in human development.

Revisiting Mt Fuji's groundwater origins with helium, vanadium and environmental DNA tracers

Known locally as the water mountain, for millennia Japan's iconic Mt Fuji has provided safe drinking water to millions of people via a vast network of groundwater and freshwater springs. Groundwater, which is recharged at high elevations, flows down Fuji's flanks within three basaltic aquifers, ultimately forming countless pristine freshwater springs among Fuji's foothills. Here we challenge the current conceptual model of Fuji being a simple system of laminar groundwater flow with little to no vertical exchange between its three aquifers. This model contrasts strongly with Fuji's extreme tectonic instability due to its unique location on top of the only known continental trench-trench-trench triple junction, its complex geology and its unusual microbial spring water communities. On the basis of a unique combination of microbial environmental DNA, vanadium and helium tracers, we provide evidence for prevailing deep circulation and a previously unknown deep groundwater contribution to Fuji's freshwater springs. The most substantial deep groundwater upwelling has been found along Japan's most tectonically active region, the Fujikawa-kako Fault Zone. Our findings broaden the hydrogeological understanding of Fuji and demonstrate the vast potential of combining environmental DNA, on-site noble gas and trace element analyses for groundwater science.

Calmodulinopathy is a common cause of critical cardiac phenotypes in fetus and infancy

Background

Cardiac calmodulinopathy is a life-threatening arrhythmia syndrome which presents several phenotypes of inherited primary arrhythmia syndrome (IPAS), and caused by mutations in calmodulin-encoded genes (CALM1–3). We aimed clarify the frequency and their clinical characteristics of calmodulinopathy in our IPAS cohort.

Methods

By using next generation sequencing, we screened arrhythmia related genes including calmodulin-encoding genes in 322 unrelated symptomatic children (0–12 years) who were suspected as IPAS; they included 40 cases with lethal arrhythmic attacks (LAE) under 6-year-old. After gene screening, we investigated their physiological and clinical characteristics about mutation carriers.

Results

Among 322 children, we identified 6 mutations of calmodulin-encoded genes in 9 probands (2.8%); one CALM1 in 2 probands (N98S), and 5 CALM2 in 7 probands (E46K, D96V, D96G, N98S, E141K). Their clinical diagnoses were long QT syndrome (LQTS, n=4), catecholaminergic polymorphic ventricular tachycardia (CPVT, n=3) and both (n=2). Their age of diagnosis ranges at 0–9 with the median of 5 years. There were three major clinical phenotypes; 1) CALM2-D96V, and E141K: two infants with advanced atrio-ventricular block, significant QTc prolongation, severe heart failure from their fetal period – both of them deceased within 1.5-year-old. Their clinical phenotypes resembled classical Timothy syndrome caused by CACNA1C mutations. 2) CALM1-N98S (n=2), CALM2-N98S (n=2), and CALM2-D96G: four preschoolers with LAEs and one syncope: all of them were 3–5 years old. In addition, a T wave morphology of CALM2-D96G carrier was very similar to LQT1. 3) CALM2-E46K (n=2): two were first diagnosed with neurological and developmental disorders, and showed phenotype of CPVT: their cardiac phenotypes were milder compared with that of 1) or 2). Overall, these phenotypes seemed to be mutation specific (indicated in figure). Their cardiac features were severer, and the onset of LAEs was earlier compared with other genotypes of LQTS/CPVT. As the treatment, β-blocker was effective for control of LAEs.

Conclusion

Cardiac calmodulinopathy presented serious and potentially lethal phenotypes in fetus or infancy. To prevent cardiac death in them, we must correctly diagnose and start the treatment as earlier as possible.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): MEXT KAKENHI from the Ministry of Education, Culture, Sports, Science, and Technology of Japan

Different prognosis of ARVC patients between DSG2 and PKP2 variant carriers

Background

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy mainly caused by desmosomal gene variants. In Europe and North America, pathogenic variants in PKP2 were identified in most of the ARVC patients. On the other hand, we have reported that the genetic backgrounds of ARVC in Japanese were different from those in European; pathogenic variants in DSG2 were predominant in Japanese. Genotype-phenotype correlations, however, have not been clarified yet.

Purpose

In this study, we aimed to examine whether the genotype affect the phenotype and outcome in Japanese ARVC patients.

Methods and results

This study included 167 Japanese ARVC patients who received genetic testing (128 males [77%]). Their median age at diagnosis was 44 [24–55] years old and median follow-up duration was 10 [4–21] years. We found 90 patients with pathogenic variants: 52 in DSG2 (31%), 30 in PKP2 (18%), 3 in DSP (1.8%), 1 in DSC (0.6%), 1 in JUP (0.6%) and 3 in DES (1.8%). The age of the first sustained ventricular arrhythmia (SVT) were older in the patients with DSG2 than those with PKP2 variants (48±15 years vs. 35±15 years, P=0.008) but younger in DSG2 variant carriers at the first hospitalization for heart failure (41 [22–61] years vs. 67 [61–74] years, P=0.03). The left ventricular ejection fractions of DSG2 variant carriers were significantly lower at diagnosis than that of PKP2 (52 [41–60] % vs. 61 [56–66] %, P=0.002). Kaplan-Meier survival curve for lethal arrhythmic events including SVT, ventricular fibrillation and sudden death revealed that the event rate of DSG2 variant carriers was significantly lower than that of PKP2 (log-rank test, P=0.02) (Fig. 1).

Among 11 patients who had both SVT and hospitalizations for HF, 7 PKP2 variant carriers had SVT first, then, hospitalized for HF (48 [35–53] years and 67 [55–71] years, P=0.02). Contrary, the clinical course of 4 DSG2 variants carriers were different from those with PKP2 (54 [40–68] years for SVT and 65 [56–70, P=0.1] years for HF) (Fig. 2).

Conclusion

The patients with DSG2, which is the major causative gene for ARVC in Japanese, show different phenotype and outcome from those with PKP2. We should examine the effect of variants on the prognosis of ARVC patients in more large population including various ethnics.

Funding Acknowledgement

Type of funding sources: None.

Whole-exome analysis of 177 pediatric patients with undiagnosed diseases

Recently, whole-exome sequencing (WES) has been used for genetic diagnoses of patients who remain otherwise undiagnosed. WES was performed in 177 Japanese patients with undiagnosed conditions who were referred to the Tokai regional branch of the Initiative on Rare and Undiagnosed Diseases (IRUD) (TOKAI-IRUD). This study included only patients who had not previously received genome-wide testing. Review meetings with specialists in various medical fields were held to evaluate the genetic diagnosis in each case, which was based on the guidelines of the American College of Medical Genetics and Genomics. WES identified diagnostic single-nucleotide variants in 66 patients and copy number variants (CNVs) in 11 patients. Additionally, a patient was diagnosed with Angelman syndrome with a complex clinical phenotype upon detection of a paternally derived uniparental disomy (UPD) [upd(15)pat] wherein the patient carried a homozygous DUOX2 p.E520D variant in the UPD region. Functional analysis confirmed that this DUOX2 variant was a loss-of-function missense substitution and the primary cause of congenital hypothyroidism. A significantly higher proportion of genetic diagnoses was achieved compared to previous reports (44%, 78/177 vs. 24-35%, respectively), probably due to detailed discussions and the higher rate of CNV detection.

Tislelizumab versus chemotherapy as second-line treatment of advanced or metastatic esophageal squamous cell carcinoma (RATIONALE 302): impact on health-related quality of life

Background

RATIONALE 302 (NCT03430843) an open-label, phase III study of second-line treatment of advanced/metastatic esophageal squamous cell carcinoma (ESCC), reported that tislelizumab, relative to investigator-chosen chemotherapy (ICC), was associated with improvements in overall survival and a favorable safety profile. This study assessed the health-related quality of life (HRQoL) and ESCC-related symptoms of patients in RATIONALE 302.

Methods

Adults with advanced/metastatic ESCC whose disease progressed following prior systemic therapy were randomized 1 : 1 to receive either tislelizumab or ICC (paclitaxel, docetaxel, or irinotecan). HRQoL was measured using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 items (EORTC QLQ-C30), the EORTC Quality of Life Questionnaire Oesophageal Cancer Module 18 items (QLQ-OES18), and the EuroQoL Five-Dimensions Five-Levels (EQ-5D-5L) visual analogue scale. Mixed effect modeling for repeated measurements examined changes from baseline to weeks 12 and 18. The Kaplan–Meier method was used to examine time to deterioration.

Results

Overall, 512 patients were randomized to tislelizumab (n = 256) or ICC (n = 256). The tislelizumab arm maintained QLQ-C30 global health status/quality whereas the ICC arm worsened at week 12 {difference in least square (LS) mean change: 5.8 [95% confidence interval (CI): 2.0-9.5], P = 0.0028} and week 18 [difference in LS mean change: 8.1 (95% CI: 3.4-12.8), P = 0.0008]. Physical functioning (week 18) and fatigue (weeks 12 and 18) worsened less in the tislelizumab compared with the ICC arm. The tislelizumab arm improved in reflux symptoms, whereas the ICC worsened at week 12 [difference in LS mean change: −4.1 (95% CI: −7.6 to −0.6), P = 0.0229]. The visual analogue scale remained consistent in the tislelizumab arm whereas it worsened in the ICC arm. The hazard of time to deterioration was lower in tislelizumab patients compared with ICC for physical functioning and reflux.

Conclusions

HRQoL, including fatigue symptoms and physical functioning, was maintained in patients with advanced or metastatic ESCC receiving tislelizumab compared with ICC-treated patients. These results provide additional support for the benefits of tislelizumab in this patient population.

•

Global health status and HRQoL remained consistent in the tislelizumab arm whereas the ICC arm experienced worsening.

•

Fatigue and physical functioning worsened in both arms; however, the worsening was greater in the ICC arm.

•

The tislelizumab arm was at lower risk of reaching the threshold for worsening in physical functioning and reflux.

Imaging-based feedback cooling of a levitated nanoparticle

Imaging-based detection of the motion of levitated nanoparticles complements a widely used interferometric detection method, providing a precise and robust way to estimate the position of the particle. Here, we demonstrate a camera-based feedback cooling scheme for a charged nanoparticle levitated in a linear Paul trap. The nanoparticle levitated in vacuum was imaged using a complementary metal-oxide semiconductor (CMOS) camera system. The images were processed in real-time with a microcontroller integrated with a CMOS image sensor. The phase-delayed position signal was fed back to one of the trap electrodes, resulting in cooling by velocity damping. Our study provides a simple and versatile approach applicable for the control of low-frequency mechanical oscillators.

O-272 Letrozole-induced endometrial preparation improved pregnancy outcomes after frozen blastocyst transfer compared to the natural cycle

Study question

Does letrozole-induced endometrial preparation affect pregnancy outcomes, perinatal outcomes, and congenital anomalies after single vitrified-warmed blastocyst transfers (SVBTs) when compared with the natural cycle?

Summary answer

Letrozole-induced endometrial preparation improved live birth rate without any adverse effects on perinatal outcomes and congenital anomalies after SVBTs.

What is known already

Letrozole treatment is considered an effective option in endometrial preparation for frozen embryo transfers in patients with ovulation disorders or irregular menstruation; however, the effectiveness of letrozole-induced endometrial preparation is still unclear in ovulatory patients. Furthermore, there is no comparative study reporting on pregnancy complications and congenital anomalies after frozen embryo transfers comparing natural and letrozole-assisted cycles.

Study design, size, duration

This retrospective study, at a major academic fertility centre, analysed a total of 14,611 clinical records of women who underwent SVBTs comprising both natural and letrozole-assisted cycles between July 2015 and June 2020. The cycle characteristics, pregnancy outcomes (clinical pregnancy, ongoing pregnancy, and live birth), and the incidence of pregnancy complications and congenital anomalies were statistically compared between the natural and letrozole groups.

Participants/materials, setting, methods

The study reviewed ovulatory patients who underwent their first SVBT during the study period. Some patients took letrozole during the early proliferative phase to promote follicular development and maturation (letrozole group). Ovulation was triggered by GnRH agonist and SVBTs were performed on day five after ovulation. Propensity score matching was performed to reduce any bias from patient characteristics. Multivariate logistic analysis was performed to evaluate the effects of letrozole administration on pregnancy and perinatal outcomes.

Main results and the role of chance

After propensity score matching, the characteristics of patients and transferred blastocysts were comparable between groups. The serum progesterone level was also significantly increased in the letrozole group (P &lt; 0.0001). Although no difference was observed regarding implantation rate between groups, the rates of clinical pregnancy, ongoing pregnancy, and delivery in the letrozole group were all significantly higher than that in the natural group (P = 0.0273, P = 0.0162, P = 0.0479, respectively). The incidence of early pregnancy loss, miscarriage, and stillbirth were comparable between groups. Multivariate logistic regression analysis also demonstrated that the administration of letrozole during an SVBT cycle significantly improved the live birth rate (AOR, 1.160; P = 0.0355). The incidence of pregnancy complications was comparable between groups. The caesarean section rate was significantly lower in the letrozole group than that in the natural group (P = 0.0464). Gestational age, birth length, birth weight, and infant sex, as well as the incidence of pregnancy complications and birth defects, were statistically comparable between groups. Furthermore, multivariate logistic regression analysis showed that perinatal outcomes were not affected by letrozole-induced endometrial preparation, although the incidence of caesarean section was decreased in the letrozole group (AOR, 0.788; P = 0.0355).

Limitations, reasons for caution

Our findings are not compared with reported incidences of pregnancy complications and congenital anomalies in natural pregnancy. Furthermore, the study was retrospective in nature, and further multicentre studies are required to ascertain the generalisability of these findings for other clinics with different protocols and/or patient demographics.

Wider implications of the findings

Letrozole administration both extended the proliferative phase and increased luteal function, resulting in an improvement of live birth rates without any adverse effects. Therefore, letrozole-induced endometrial preparation might be a safe and more effective strategy for patients with shortened proliferative phase or insufficient luteal function.

Trial registration number

not applicable

O-064 Recovery culture of human cryopreserved blastocysts with prolactin after warming improves trophoblast outgrowth

Study question

Does prolactin (PRL) treatment during recovery culture affect human blastocyst outgrowth?

Summary answer

PRL treatment for 120 min promoted trophoblast outgrowth in cryopreserved human blastocysts by upregulating the expressions of epithelial-to-mesenchymal transition (EMT) and focal adhesion-related genes.

What is known already

Human embryos express the PRL receptor at the morula and the blastocyst stages. This expression correlates with the blastocyst diameter and the time required for the embryos to reach the blastocyst stage. Treatment with PRL from cleavage to the blastocyst stage improves blastocyst outgrowth to fibronectin. However, whether PRL treatment after warming cryopreserved blastocysts cultured to the blastocyst stage without PRL influences outgrowth competence remains unknown. Furthermore, the optimal time for post-warming PRL treatment remains to be ascertained.

Study design, size, duration

A total of 374 discarded human vitrified blastocysts donated for research by consenting couples were used. The study was approved by the Institutional Review Board. The blastocysts were randomly allocated to two groups, to be cultured in medium either with PRL (n = 208) or without PRL (control; n = 166). The gene expression level, blastocyst adhesion, outgrowth area, and distance of trophoblast migration were compared between the groups.

Participants/materials, setting, methods

Vitrified human blastocysts were cultured for 120 min after warming. Some blastocysts were treated with PRL for 15–120 min during the recovery period. The blastocysts were plated on fibronectin-coated dishes and cultured to assess blastocyst adhesion and outgrowth. The expressions of PRL-interacting genes were assessed by quantitative RT-PCR 12 h after outgrowth culture. The migration distance at the outer edge of the trophoblast cells was examined using time-lapse systems.

Main results and the role of chance

The mRNA expressions of ezrin, radixin, and moesin, which regulate cell adhesion and invasion by controlling actin reorganisation during EMT, was stimulated by PRL treatment for 120 min. The expressions of EMT-related genes, transforming growth factor β1, snail1, and twist1 were also promoted by treatment with PRL for 120 min. The blastocysts treated with PRL also exhibited augmented expression of cadherin2 and transcriptional repression of cadherin1. Higher mRNA expressions of integrin-based focal adhesion-related genes, ITGA5 and ITGB1, were observed after treatment with PRL for 120 min compared to that in the other groups. PRL treatment for 120 min did not alter the rate of blastocyst adhesion to fibronectin-coated dishes 96 h after the outgrowth culture assay. However, multiple linear regression analysis revealed that the outgrowth area was significantly increased in blastocysts treated with PRL. The migration distance of trophoblast cells was significantly increased after PRL treatment. Furthermore, a more beneficial effect of prolactin treatment on blastocyst outgrowth was observed when the blastocysts were vitrified on day 5 compared to that when the blastocysts were vitrified on day 6. Moreover, the outgrowth area was increased by PRL treatment when the blastocyst diameter was larger than 180 µm.

Limitations, reasons for caution

The results may vary between in vivo and in vitro conditions. Further clinical studies are required to explore the clinical efficacy of PRL treatment.

Wider implications of the findings

This study showed that PRL treatment for 120 min improved trophoblast migration in cryopreserved human blastocysts. Therefore, recovery culture with PRL treatment post-warming followed by blastocyst transfer could improve pregnancy outcomes.

Trial registration number

not applicable