Comparison of time to clinically meaningful improvement in quality of life in neurological disorders in patients treated with natalizumab versus ocrelizumab

Aim: To assess time to improvement in Quality of Life in Neurological Disorders (Neuro-QoL) domains for patients treated with natalizumab versus ocrelizumab. Methods: Patients enrolled in the MS PATHS network who initiated treatment with either natalizumab or ocrelizumab rated the Neuro-QoL domains of physical function, symptoms, emotional health, cognitive function and social ability. Results: Time to clinically meaningful improvement was significantly shorter with natalizumab versus ocrelizumab for cognitive function (event time ratio [95% CI]: 0.37 [0.24-0.57]; p < 0.001), sleep disturbance (0.45 [0.28-0.72]; p = 0.001), social role participation (0.37 [0.21-0.66]; p = 0.001) and social role satisfaction (0.5 [0.31-0.8]; p = 0.004). Conclusion: Natalizumab had shorter time to clinically meaningful improvement in cognitive, sleep, and social role Neuro-QoL domains versus ocrelizumab.

Precision medicine analysis of heterogeneity in individual-level treatment response to amyloid beta removal in early Alzheimer's disease

INTRODUCTION

Alzheimer's disease (AD) is a neurological disorder with variability in pathology and clinical progression. AD patients may differ in individual-level benefit from amyloid beta removal therapy.

METHODS

Random forest models were applied to the EMERGE trial to create an individual-level treatment response (ITR) score which represents individual-level benefit of high-dose aducanumab relative to the placebo. This ITR score was used to test the existence of heterogeneity in treatment effect (HTE).

RESULTS

We found statistical evidence of HTE in the Clinical Dementia Rating-Sum of Boxes (CDR-SB;P =  0.034). The observed CDR-SB benefit was 0.79 points greater in the group with the top 25% of ITR score compared to the remaining 75% (P = 0.020). Of note, the highest treatment responders had lower hippocampal volume, higher plasma phosphorylated tau 181 and a shorter duration of clinical AD at baseline.

DISCUSSION

This ITR analysis provides a proof of concept for precision medicine in future AD research and drug development.

HIGHLIGHTS

Emerging trials have shown a population-level benefit from amyloid beta (Aβ) removal in slowing cognitive decline in early Alzheimer's disease (AD). This work demonstrates significant heterogeneity of individual-level treatment effect of aducanumab in early AD. The greatest clinical responders to Aβ removal therapy have a pattern of more severe neurodegenerative process.

Evaluating hybrid controls methodology in early-phase oncology trials: A simulation study based on the MORPHEUS-UC trial

Phase Ib/II oncology trials, despite their small sample sizes, aim to provide information for optimal internal company decision-making concerning novel drug development. Hybrid controls (a combination of the current control arm and controls from one or more sources of historical trial data [HTD]) can be used to increase statistical precision. Here we assess combining two sources of Roche HTD to construct a hybrid control in targeted therapy for decision-making via an extensive simulation study. Our simulations are based on the real data of one of the experimental arms and the control arm of the MORPHEUS-UC Phase Ib/II study and two Roche HTD for atezolizumab monotherapy. We consider potential complications such as model misspecification, unmeasured confounding, different sample sizes of current treatment groups, and heterogeneity among the three trials. We evaluate two frequentist methods (with both Cox and Weibull accelerated failure time [AFT] models) and three different commensurate priors in Bayesian dynamic borrowing (with a Weibull AFT model), and modifications within each of those, when estimating the effect of treatment on survival outcomes and measures of effect such as marginal hazard ratios. We assess the performance of these methods in different settings and the potential of generalizations to supplement decisions in early-phase oncology trials. The results show that the proposed joint frequentist methods and noninformative priors within Bayesian dynamic borrowing with no adjustment on covariates are preferred, especially when treatment effects across the three trials are heterogeneous. For generalization of hybrid control methods in such settings, we recommend more simulation studies.

Enhancement of blue and ultraviolet components in PCF-based supercontinuum generation through inter-modal dispersive-wave radiation

Broadband supercontinuum (SC) light sources generated through nonlinear effects in solid-core photonic crystal fibers (PCFs) have been widely used in spectroscopy, metrology, and microscopy, leading to great application successes. The short-wavelength extension of such SC sources, a longstanding challenge, has been the subject of intensive study over the past two decades. However, the exact mechanism of blue and ultraviolet light generation, especially for some resonance spectral peaks in the short-wavelength regime, is not yet fully understood. Here, we demonstrate that the effect of inter-modal dispersive-wave radiation, which results from phase matching between pump pulses at the fundamental optical mode and packets of linear waves at some higher-order modes (HOMs) propagating in the PCF core, might be one of the critical mechanisms that can result in some resonance spectral components with wavelengths much shorter than that of the pump light. We observed in an experiment that several spectral peaks resided in the blue and ultraviolet regimes of the SC spectrum, whose central wavelengths can be tuned by varying the PCF-core diameter. These experimental results can be interpreted well using the inter-modal phase-matching theory, providing some useful insights into the SC generation process.

Extracellular vesicles derived from Akkermansia muciniphila promote placentation and mitigate preeclampsia in a mouse model

Preeclampsia (PE) is a multisystem disorder with high maternal morbidity and mortality rates. Currently, no practical therapeutic approach is available to prevent PE progression, except for early delivery. Gut dysbiosis is associated with PE development. Previous data showed that the abundance of Akkermansia muciniphila (Am) was lower in patients with PE than in normotensive pregnant women. Here, in this study, decreased abundance of Am was observed in a PE mouse model. Also, we found that administration with Am could significantly attenuate systolic blood pressure, promote foetal growth and improve the placental pathology in mice with PE. Moreover, Am-derived extracellular vesicles (AmEVs) were transferred from the gastrointestinal (GI) tract to the placenta and mitigated pre-eclamptic symptoms in PE mice. These beneficial effects of AmEVs were mediated by enhanced trophoblast invasion of the spiral artery (SpA) and SpA remodelling through activation of the epidermal growth factor receptor (EGFR)-phosphatidylinositol-3-kinase (PI3K)-protein kinase B (AKT) signalling pathway. Collectively, our findings revealed the potential benefit of using AmEVs for PE treatment and highlighted important host-microbiota interactions.

Effect of reduction in brain amyloid levels on change in cognitive and functional decline in randomized clinical trials: An instrumental variable meta-analysis

INTRODUCTION

Whether the reduction in brain amyloid beta (Aβ) plaque alone may substantially slow cognitive and functional decline in patients with dementia or mild cognitive impairment due to Alzheimer's disease (AD) remains debated.

METHODS

An instrumental variable meta-analysis was performed to infer the effect of change in positron emission tomography (PET)-measured Aβ standardized uptake value ratio (SUVR) on cognitive and functional decline.

RESULTS

Pooling data from 16 randomized trials demonstrates that each 0.1-unit decrease in PET Aβ SUVR is associated with a reduction (95% confidence interval) by 0.09 (0.034-0.15), 0.33 (0.12-0.55), and 0.13 (0.017-0.24) point in the average change of the Clinical Dementia Rating-Sum of Boxes, the Alzheimer's Disease Assessment Scale-Cognitive Subscale, and the Mini-Mental State Examination, respectively.

DISCUSSION

This meta-analysis provides statistically significant evidence of a likely causal relationship between a reduction in Aβ plaque and a reduction in cognitive and functional decline in patients with AD.

HIGHLIGHTS

A widely cited meta-analysis article concluded amyloid beta reduction does not substantially improve cognition. We identified data inconsistencies in the initial publication and found new trial data. We repeated the meta-analysis after correcting data inconsistencies and adding new trial data. Updated results suggested statistically significant clinical benefit of amyloid beta reduction. Amyloid beta is a viable biological target for the treatment and prevention of AD.

Psychometric properties of the Alzheimer's Disease Cooperative Study - Activities of Daily Living for Mild Cognitive Impairment (ADCS-MCI-ADL) scale: a post hoc analysis of the ADCS ADC-008 trial

BACKGROUND

The Alzheimer's Disease Cooperative Study - Activities of Daily Living Scale for use in Mild Cognitive Impairment (MCI), the ADCS-ADL-MCI, is an evaluation scale with information provided by an informant/caregiver to describe the functional impairment of patients with MCI. As the ADCS-ADL-MCI has yet to undergo a full psychometric evaluation, this study aimed to evaluate the measurement properties of the ADCS-ADL-MCI in subjects with amnestic MCI.

METHODS

Measurement properties, including item-level analysis, internal consistency reliability, test-retest reliability, construct validity (convergent/discriminant, known-groups validity), and responsiveness were evaluated using data from the ADCS ADC-008 trial, a 36-month, multicenter, placebo-controlled study in 769 subjects with amnestic MCI (defined by clinical criteria and a global clinical dementia rating, CDR, score of 0.5). Due to most subjects' mild condition at baseline and resulting low variance in scores, psychometric properties were assessed using both baseline and 36-month data.

RESULTS

Ceiling effects were not apparent at the total score level, with 3% of the cohort reaching the maximum score of 53, despite most subjects having a relatively high score at baseline (mean score = 46.0 [standard deviation = 4.8]). Item-total correlations were overall weak at baseline, most likely due to low variability in responses; however, at month 36, good item homogeneity was found. Cronbach's alpha values ranged from acceptable (0.64 at baseline) to good (0.87 at month 36), indicating overall very good internal consistency reliability. Further, moderate to good test-retest reliability was found (intraclass correlation coefficients ranging from 0.62-0.73). The analyses also largely supported convergent/discriminant validity, especially at month 36. Finally, the ADCS-ADL-MCI discriminated well between groups showing good known-groups validity, and was responsive in patients who indicated a longitudinal change in other instruments.

CONCLUSIONS

This study provides a comprehensive psychometric evaluation of the ADCS-ADL-MCI. Findings suggest that the ADCS-ADL-MCI is a reliable, valid and responsive measure capable of capturing functional abilities in patients with amnestic MCI.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00000173.

[A descriptive analysis of tea consumption in adult twins in China]

Objective: To describe the distribution characteristics of tea consumption in adult twins recruited in the Chinese National Twin Registry (CNTR) and provide clues to genetic and environmental influences on tea consumption. Methods: Enrolled in CNTR during 2010-2018, 25 264 twin pairs aged 18 years and above were included in subsequent analysis. Random effect models were used to estimate tea consumption in the population and regional distribution characteristics. The concordance rate of the behavior and difference in consumption volume of tea within pairs were also described. Results: The mean age of all subjects was (35.38±12.45) years old. The weekly tea consumers accounted for 17.0%, with an average tea consumption of (3.36±2.44) cups per day. The proportion of weekly tea consumers was higher among males, 50-59 years old, southern, urban, educated, and the first-born in the twin pair (P<0.05), and lower among unmarried individuals (P<0.001). Within-pair analysis showed that the concordance rate of tea consumption of monozygotic (MZ) twins was higher than that of dizygotic (DZ) twins and the overall heritability of tea consumption was 13.45% (11.38%-15.51%). Stratified by the characteristics mentioned above, only in males, the concordance rate of MZ showed a tendency to be greater than that of DZ (all P<0.05). The differences in consumption volume of tea within twin pairs were minor in MZ among males (P<0.05), while the differences were not significant in female twins. Conclusion: There were discrepancies in the distribution of tea consumption among twins of different demographic and regional characteristics. Tea consumption was mainly influenced by environmental factors and slightly influenced by genetic factors. The size of genetic factors varied with gender, age, and region, and gender was a potential modified factor.

Knockdown of ENTPD5 inhibits tumor metastasis and growth via regulating the GRP78/p-eIF-2α/CHOP pathway in serous ovarian cancer

Background

Dysregulation of Ectonucleoside Triphospahate Diphosphohydrolase 5 (ENTPD5) in tumors might be associated with tumor progression, while the role of ENTPD5 in the growth and metastasis of serous ovarian cancer (SOC) is still unclear.

Methods

ENTPD5 expression patterns in ovarian cancer tissues were analyzed by qRT-PCR and immunohistochemistry assay (IHC). Two SOC cell lines, SKOV3 and OVCAR8, were stably transfected with lentivirus to build knockdown and overexpression cell lines. Clone formation assay, collagen gel droplet culture technology, wound healing assay and flow cytometry were used to assess the migration and growth traits of SOC cells. Expression levels of ENTPD5, glucose regulated protein 78 (GRP78), eukaryotic translation initiation factor 2 alpha (eIF-2α), phosphorylated -eIF-2α and, C/EBP homologous protein (CHOP) in SOC cells were detected by Western blot.

Results

Compared to fallopian tube tissues, the expression of ENTPD5 was significantly higher in tumor tissues obtained from SOC patients, and positively correlated with clinical stage and metastasis. ENTPD5 knockdown robustly inhibited cell proliferation, migration, whereas ENTPD5 overexpression elicited the opposite effect on SOC cells. ENTPD5 knockdown arrested cell cycle in G0/G1 phase and increased apoptosis. Importantly, ENTPD5 knockdown was associated with significantly decreased protein levels for GRP78, CHOP, and p-eIF-2α, suggesting possible involvement of ENTPD5 in endoplasmic reticulum stress (ERS).

Conclusions

Our study demonstrates that ENTPD5 knockdown inhibited SOC cell proliferation, migration and restrained the activation of the GRP78/p-eIF-2α/CHOP pathway, which provides a potentially effective therapeutic target for the treatment of SOC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-022-00996-0.

[A descriptive analysis on coronary heart disease in adult twins in China]

Objective: To describe the distribution characteristics of coronary heart disease in adult twins recruited from Chinese Twin Registry (CNTR), and provide clues and evidence for the effect of genetic and environmental influences on coronary heart disease. Methods: By using the data of CNTR during 2010-2018, a total of 34 583 twin pairs aged ≥18 years who completed questionnaire survey and had related information were included in the current study to analyze the population and area distribution characteristics of coronary heart disease. Random effect models were used to compare the differences between groups. The concordane rate of coronary heart disease were calculated respectively in monozygotic (MZ) twin pairs and dizygotic (DZ) twin pairs to estimate the heritability. Results: The twin pairs included in this analysis were aged (34.2±12.4) years. The overall prevalence rate of coronary heart disease in twin pairs was 0.7%. Twin pairs who were women, older, obese and lived in northern China had higher prevalence of coronary heart disease (P<0.05). Intra-pair analysis in the same-sex twin pairs found that the concordane rate of coronary heart disease was higher in MZ twin pairs (25.3%) than in DZ twins (7.4%), and the difference was statistically significant (P<0.001). The overall heritability of coronary heart disease was 19.3% (95%CI: 11.8%-26.8%). Stratified by gender, age and area, the concordane rate was still higher in MZ twin pairs than in DZ pairs. Participants who were women, aged 18-30 years or ≥60 years and lived in northern China had a higher heritability of coronary heart disease. Conclusion: The distribution of coronary heart disease in twin pairs differed in populations and areas. The prevalence of coronary heart disease was affected by genetic factors, but the effect varied with age, gender and area.

[A descriptive analysis on type 2 diabetes in twins in China]

Objective: To describe the distribution characteristics of type 2 diabetes in twins in Chinese National Twin Registry (CNTR), provide clues and evidence for revealing the influence of genetic and environmental factors for type 2 diabetes. Methods: Of all twins registered in the CNTR during 2010-2018, a total 18 855 twin pairs aged ≥30 years with complete registration information were included in the analysis. The random effect model was used to describe the population and area distribution characteristics and concordance of type 2 diabetes in twin pairs. Results: The mean age of the subjects was (42.8±10.2) years, the study subjects included 10 339 monozygotic (MZ) twin pairs and 8 516 dizygotic (DZ) twin pairs. The self-reported prevalence rate of type 2 diabetes was 2.2% in total population and there was no sighificant difference between MZ and DZ. Intra-twin pairs analysis showed that the concordance rate of type 2 diabetes was 38.2% in MZ twin pairs, and 16.0% in DZ twin pairs, the difference was statistically significant (P<0.001). The concordance rate of type 2 diabetes in MZ twin parts was higher than that in DZ twin pairs in both men and women, in different age groups and in different areas (P<0.05). Further stratified analysis showed that in northern China, only MZ twin pairs less than 60 years old were found to have a higher concordance rate of type 2 diabetes compared with DZ twin pairs (P<0.05). In southern China, the co-prevalence rate in male MZ twin pairs aged ≥60 years was still higher than that in DZ twin pairs (P<0.05). Conclusion: The twin pairs in this study had a lower self-reported prevalence of type 2 diabetes than the general population. The study results suggested that genetic factors play a role in type 2 diabetes prevalence in both men and women, in different age groups and in different areas, however, the effect might vary.

"Translating" All-Cause Mortality Rate Ratios or Hazard Ratios to Age-, Longevity-, and Probability-Based Measures

Epidemiologists commonly use an adjusted hazard ratio or incidence density ratio, or a standardized mortality ratio, to measure a difference in all-cause mortality rates. They seldom translate it into an age-, time-, or probability-based measure that would be easier to communicate and to relate to. Several articles have shown how to translate from a standardized mortality ratio or hazard ratio to a longevity difference, a difference in actuarial ages, or a probability of being outlived. In this paper, we describe the settings where these translations are and are not appropriate and provide some of the heuristics behind the formulae. The tools that yield differences in "effective age" and in longevity are applicable when both 1) the mortality rate ratio (hazard ratio) is constant over age and 2) the rates themselves are log-linear in age. The "probability/odds of being outlived" metric is applicable whenever the first condition holds, and thus it provides no direct information on the magnitude of the effective age/longevity difference.

Flexible extension of the accelerated failure time model to account for nonlinear and time-dependent effects of covariates on the hazard

The accelerated failure time model is an alternative to the Cox proportional hazards model in survival analysis. However, conclusions regarding the associations of prognostic factors with event times are valid only if the underlying modeling assumptions are met. In contrast to several flexible methods for relaxing the proportional hazards and linearity assumptions in the Cox model, formal investigation of the constant-over-time time ratio and linearity assumptions in the accelerated failure time model has been limited. Yet, in practice, prognostic factors may have time-dependent and/or nonlinear effects. Furthermore, parametric accelerated failure time models require correct specification of the baseline hazard function, which is treated as a nuisance parameter in the Cox proportional hazards model, and is rarely known in practice. To address these challenges, we propose a flexible extension of the accelerated failure time model where unpenalized regression B-splines are used to model (i) the baseline hazard function of arbitrary shape, (ii) the time-dependent covariate effects on the hazard, and (iii) nonlinear effects for continuous covariates. Simulations evaluate the accuracy of the time-dependent and/or nonlinear estimates, and of the resulting survival functions, in multivariable settings. The proposed flexible extension of the accelerated failure time model is applied to re-assess the effects of prognostic factors on mortality after septic shock.

Immune checkpoint inhibitors and cellular treatment for lymphoma immunotherapy

Malignant lymphoma (ML) is a common hematological malignancy with many subtypes. Patients with ML usually undergo traditional treatment failure and become relapsed or refractory (R/R) cases. Recently, immunotherapy, such as immune checkpoint inhibitors (ICIs) and cellular treatment, has gradually emerged and used in clinical trials with encouraging achievements for ML treatment, which exerts anti-tumor activity by blocking the immune evasion of tumor cells and enhancing the attack ability of immune cells. Targets of immune checkpoints include programmed cell death-1 (PD-1), programmed cell death-ligand 1 (PD-L1), cytotoxic T lymphocyte-associated protein 4 (CTLA-4), T cell immunoglobulin and ITIM domain (TIGIT), T cell immunoglobulin-3 (TIM-3) and lymphocyte activation gene 3 (LAG-3). Examples of cellular treatment are chimeric antigen receptor (CAR) T cells, cytokine-induced killer (CIK) cells and natural killer (NK) cells. This review aimed to present the current progress and future prospects of immunotherapy in lymphoma, with the focus upon ICIs and cellular treatment.

Structure and thermal properties of beeswax-based oleogels with different types of vegetable oil

Beeswax-based oleogels with different types of vegetable oil, including camellia oil (CO), soybean oil (SO), sunflower oil (SFO), or flaxseed oil (FO), were prepared and their structure and thermal properties were evaluated. The critical concentration of oleogel obtained from each of CO, SO, and SFO at 25 °C was 3% (w/w), and that from FO was 4%. Thermal measurements revealed similar thermodynamic curves for oleogels in different lipid phases. X-Ray diffraction showed orthorhombic perpendicular subcell packing and characteristic peaks of the β’ form. Furthermore, a morphology analysis of the crystals showed that they were needle shaped. Fourier transform-infrared spectra revealed that beeswax-based oleogels were formed via non-covalent bonds and may be stabilized with physical entanglements. The oleogels showed oil type-dependent oxidative abilities, but they were all stable and showed no obvious changes in peroxide value during 90 days of storage at 5 °C.

Effectiveness and safety among direct oral anticoagulants in nonvalvular atrial fibrillation: A multi-database cohort study with meta-analysis

AIMS

There are conflicting signals in the literature about comparative safety and effectiveness of direct oral anticoagulants (DOACs) for nonvalvular atrial fibrillation (NVAF).

METHODS

We conducted multicentre matched cohort studies with secondary meta-analysis to assess safety and effectiveness of dabigatran, rivaroxaban and apixaban across 9 administrative healthcare databases. We included adults with NVAF initiating anticoagulation therapy (dabigatran, rivaroxaban or apixaban), and constructed 3 cohorts to compare DOACs pairwise. The primary outcome was pooled hazard ratio (pHR) of ischaemic stroke or systemic thromboembolism. Secondary outcomes included pHR of major bleeding, and a composite of stroke, major bleeding, or all-cause mortality. We used proportional hazard Cox regressions models, and pooled estimates were obtained with random effect meta-analyses.

RESULTS

The cohorts included 73 414 new users of dabigatran, 92 881 of rivaroxaban, and 61 284 of apixaban. After matching, the pHRs (95% confidence intervals) comparing rivaroxaban initiation to dabigatran were: 1.11 (0.93, 1.32) for ischaemic stroke or systemic thromboembolism, 1.26 (1.09, 1.46) for major bleeding, and 1.17 (1.05, 1.30) for the composite endpoint. For apixaban vs dabigatran, they were: 0.91 (0.74, 1.12) for ischaemic stroke or systemic thromboembolism, 0.89 (0.75, 1.05) for major bleeding, and 0.94 (0.78 to 1.14) for the composite endpoint. For apixaban vs rivaroxaban, they were: 0.85 (0.74, 0.99) for ischaemic stroke or systemic thromboembolism, 0.61 (0.53, 0.70) for major bleeding, and 0.82 (0.76, 0.88) for the composite endpoint.

CONCLUSION

We found that apixaban use is associated with lower risks of stroke and bleeding compared with rivaroxaban, and similar risks compared with dabigatran.

[Clinical, myopathological and genetic features of two Chinese families with paramyotonia congenita]

Objective: To investigate the clinical, myopathological and genetic mutation characteristics in two Chinese families with paramyotonia congenita (PMC). Methods: Clinical manifestations, electrophysiology, muscle pathology and gene sequencing of two Chinese families with PMC were analyzed retrospectively. Results: Family 1 involved 12 patients in 4 consecutive generations and family 2 involved only 1 patient in 3 generations. The onset of symptoms in all patients started at early childhood. Both probands presented with myotonia triggered by cold and paroxysmal weakness. However, the other 11 patients in family 1 only manifested cold-induced myotonia. Serum creatine kinase (CK) was slightly elevated between attacks of weakness in the 2 probands, and was even greater than 10 000 U/L during the episodes of weakness in the second proband, whose lower limb MRI revealed edema in bilateral medial gastrocnemius. Electromyography showed diffuse myotonia discharge and myogenic impairment in both probands, and myotonia discharge in the first proband's mother. Muscle pathology of both probands showed mild myopathic changes, and tube aggregation was occasionally observed in the second one. Genetic testing revealed a maternally inherited heterozygous R1448H mutation of SCN4A gene in the first proband and part of his family. A novel heterozygous R1448G mutation of SCN4A gene was reported in the second proband. Conclusions: Cold-triggered myotonia with or without paroxysmal weakness are the common characteristics of PMC. Myotonic potential and myogenic impairment can be tested in electromyography. The p.R1448G mutation is a new missense mutation.

Spline-based accelerated failure time model

The accelerated failure time (AFT) model has been suggested as an alternative to the Cox proportional hazards model. However, a parametric AFT model requires the specification of an appropriate distribution for the event time, which is often difficult to identify in real-life studies and may limit applications. A semiparametric AFT model was developed by Komárek et al based on smoothed error distribution that does not require such specification. In this article, we develop a spline-based AFT model that also does not require specification of the parametric family of event time distribution. The baseline hazard function is modeled by regression B-splines, allowing for the estimation of a variety of smooth and flexible shapes. In comprehensive simulations, we validate the performance of our approach and compare with the results from parametric AFT models and the approach of Komárek. Both the proposed spline-based AFT model and the approach of Komárek provided unbiased estimates of covariate effects and survival curves for a variety of scenarios in which the event time followed different distributions, including both simple and complex cases. Spline-based estimates of the baseline hazard showed also a satisfactory numerical stability. As expected, the baseline hazard and survival probabilities estimated by the misspecified parametric AFT models deviated from the truth. We illustrated the application of the proposed model in a study of colon cancer.

Comparative effectiveness and safety of direct oral anticoagulants versus vitamin K antagonists in nonvalvular atrial fibrillation: a Canadian multicentre observational cohort study

BACKGROUND

Direct oral anticoagulants (DOACs) have widely replaced warfarin for stroke prevention in nonvalvular atrial fibrillation. Our objective was to compare the safety and effectiveness of DOACs (dabigatran, rivaroxaban, apixaban) versus warfarin for stroke prevention in nonvalvular atrial fibrillation in the Canadian setting.

METHODS

We conducted a population-based observational multicentre cohort study with propensity score matching and subsequent meta-analysis. We used health care databases from 7 Canadian provinces (British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Quebec and Nova Scotia). Patients with nonvalvular atrial fibrillation who initiated anticoagulation therapy in 2009-2017 were matched to an equal number who initiated warfarin. The primary outcome was the pooled hazard ratio (HR) for ischemic stroke or systemic embolization. Secondary outcomes included pooled HRs for major bleeding; a composite outcome of stroke, systemic embolization, major bleeding and all-cause mortality; and myocardial infarction. We modelled HRs using proportional hazard Cox regression with inverse probability of censoring weights, and estimated pooled HRs with random-effect meta-analyses.

RESULTS

We included 128 273 patients who initiated anticoagulation with a DOAC (40 503 dabigatran, 49 498 rivaroxaban and 38 272 apixaban) and 128 273 patients who initiated anticoagulation with warfarin. The pooled HR for ischemic stroke or systemic embolization comparing DOACs to warfarin was 1.02 (95% confidence interval [CI] 0.87 to 1.19). Direct oral anticoagulants were associated with lower rates of major bleeding (pooled HR 0.81, 95% CI 0.69 to 0.97), the composite outcome (pooled HR 0.81, 95% CI 0.74 to 0.89) and all-cause mortality (pooled HR 0.81, 95% CI 0.78 to 0.85).

INTERPRETATION

In this real-world study, DOACs were associated with similar risks of ischemic stroke or systemic embolization, and lower risks of bleeding and total mortality compared to warfarin. These findings support the use of DOACs for anticoagulation in nonvalvular atrial fibrillation.

TRIAL REGISTRATION

ClinicalTrials.gov, no. NCT03596502.

Single-scan, dual-functional interferometer for fast spatio-temporal characterization of few-cycle pulses

Accurate and fast characterization of spatio-temporal information of high-intensity, ultrashort pulses is crucial in the field of strong-field laser science and technology. While conventional self-referenced interferometers were widely used to retrieve the spatial profile of the relative spectral phase of pulses, additional measurements of temporal and spectral information at a particular position of the laser beam, however, were necessary to remove the indeterminacy, which increases the system complexity. Here we report an advanced, dual-functional interferometer that is able to reconstruct the complete spatio-temporal information of ultrashort pulses with a single scan of the interferometer arm. The setup integrates an interferometric frequency-resolved optical gating (FROG) with a radial shearing Michelson interferometer. Through scanning one arm of the interferometer, both the cross-correlated FROG trace at the central part of the laser beam and the delay-dependent interferograms of the entire laser profile are simultaneously obtained, allowing a fast three-dimensional reconstruction of few-cycle laser pulses.

Neuropsychiatric Symptoms and Risk Factors in Mild Cognitive Impairment: A Cohort Investigation of Elderly Patients

BACKGROUND

Neuropsychiatric symptoms (NPS) have been shown to affect the progression and development of Alzheimer's disease (AD) in the elderly. However, the published data are still controversial and limited in large cohort-based NPS study.

AIM

To explore the potential relationship between NPS and mild cognitive impairment (MCI) among the elderly of Chinese community.

METHODS

A total of 465 Chinese community-dwelling elderly (age ≥ 60 years) with mild cognitive impairment (MCI) were recruited into this investigation. At baseline, enrolled participants were assessed for Clinical Dementia Rating (CDR), mini-psychiatric examination. They were also subjected to categorical language fluency test, list learning and delayed recall. We assessed the NPS severity by Neuropsychological Inventory (NPI). The global cognitive status (GCS) of the participants at the end of the 3-year study period were measured with the CDR.

RESULTS

Approximately 41.6% of subjects had 1 or more NPS (total NPI score ≥ 1) at baseline. The most common NPSs were nocturnal behavior (20.8%), depression (17.3%), apathy (12.7%) and anxiety (13.2%). At the end of 3-year follow-up, 26.9% of baseline depressed patients developed AD, while 15.2% of baseline non-depressed patients developed AD (χ2 = 4.86, P=0. 04). Abnormal motor behavior was significantly correlated with cognitive deterioration as well (χ2 = 5.75, P=0. 03). Logistic regression analysis revealed that depression was considered as a risk factor for AD progression at baseline (95% CI: 1.12-5.67, OR=2.37, P=0.03).

CONCLUSIONS

Depression may be an independent factor representing early neurodegeneration in elder patients with MCI. Further studies are warranted to assess whether effective management of NPS promotes the cognitive functions.

Formation of optical supramolecular structures in a fibre laser by tailoring long-range soliton interactions

Self-assembly of fundamental elements through weak, long-range interactions plays a central role in both supramolecular DNA assembly and bottom-up synthesis of nanostructures. Optical solitons, analogous in many ways to particles, arise from the balance between nonlinearity and dispersion and have been studied in numerous optical systems. Although both short- and long-range interactions between optical solitons have attracted extensive interest for decades, stable soliton supramolecules, with multiple aspects of complexity and flexibility, have thus far escaped experimental observation due to the absence of techniques for enhancing and controlling the long-range inter-soliton forces. Here we report that long-range soliton interactions originating from optoacoustic effects and dispersive-wave radiations can be precisely tailored in a fibre laser cavity, enabling self-assembly of large numbers of optical solitons into highly-ordered supramolecular structures. We demonstrate several features of such optical structures, highlighting their potential applications in optical information storage and ultrafast laser-field manipulation.

Route from single-pulse to multi-pulse states in a mid-infrared soliton fiber laser

State-of-the-art ultrafast mid-IR fiber lasers deliver optical solitons with durations of several hundred femtoseconds. The Er- or Ho-doped fluoride gain fibers generally used in these lasers have strong anomalous dispersion at ∼3 µm, which generally forces them to operate in the soliton regime. Here we report that a pulse-energy clamping effect, caused by the buildup of intracavity nonlinearities, limits the shortest obtainable pulse durations in these mid-infrared soliton fiber lasers. Excessive intra-cavity energy results in soliton instability, collapse and fragmentation into a variety of stable multi-pulse states, including phase-locked soliton molecules and harmonically mode-locked states. We report that the spectral evolution of the mid-IR laser pulses can be recorded between roundtrips through stretching their second-harmonic signal in a 25-km-length of single-mode fiber. Using a modified dispersive Fourier transform set-up, we were able to perform for the first time spectro-temporal measurements of mid-IR laser pulses both in the pulsed state and during pulse collapse and fragmentation. The results provide insight into the complex nonlinear dynamics of mid-IR soliton fiber lasers and open up new opportunities for obtaining a variety of stable multi-pulse mode-locked states at mid-IR wavelengths.

Continuously wavelength-tunable blueshifting soliton generated in gas-filled photonic crystal fibers

We experimentally report the generation of wavelength-tunable blueshifting soliton in the visible spectral region through a gas-filled single-ring photonic crystal fiber (SR-PCF). In particular, in a He-filled SR-PCF, we observed a sharp narrow-band spectral peak at the first resonant spectral region of the SR-PCF, which results from phase-matched nonlinear processes. To the best of our knowledge, this is the first time investigating the influence of the core-cladding resonance on the blueshifting soliton. In addition, when Ar gas was filled into the SR-PCF, some interference fringes on the blueshifting soliton were observed at high pulse-energy levels due to plasma-induced pulse fission. These two experimental observations are confirmed by numerical simulations. Furthermore, through properly adjusting input pulse energy, we found that the blueshifting soliton can obtain a high conversion efficiency (∼84%) and its wavelength can be tuned over hundreds of nanometers (∼240  nm).

[Skeletal muscle MRI of lower limbs in patients with facioscapulohumeral dystrophy]

Objective: To investigate MRI features of lower limbs in patients with facioscapulohumeral dystrophy(FSHD). Methods: The clinical manifestations, myopathological findings and MRI images of 5 FSHD patients were studied retrospectively from June 2016 to December 2017 at Department of Neurology, Henan Provincial People's Hospital, 3 of which had a family history. Analysis of T(1)WI images enabled us to describe muscle fatty infiltration and STIR images to describe muscle edema. Each muscle was scored according to its fatty degeneration (fat replacement score range from 0-4). Results: The 5 patients were all asymmetrically involved. At the thigh level, the hamstrings were more affected than anterior muscles in 4 patients, and anterior muscles were more affected than hamstrings in only 1 patient. The most affected thigh muscles were usually the adductor magnus, semimembranosus, semitendinosus, femoral biceps long head and vastus medialis muscles (average fat replacement score of each muscle was more than 3). The calves were less affected than thighs.The average fat replacement score of the calf muscles was 1.0 for soleus, 0.9 for medial gastrocnemius, 0.8 for tibialis anterior, and 0.4 for lateral gastrocnemius. There was no fatty infiltration in peroneus and tibialis posterior. 4 out of 5 patients had edema in the lower limb muscles. Conclusion: Asymmetric involvement is a definitely helpful clue suggesting FSHD, and edema is a common phenomenon. At the thigh level, no unique imaging pattern can be highlighted in all the FSHD patients, overall, the hamstring, adductor magnus and vastus medialis are usually the most severely affected muscles. The calf muscles are less affected than the thigh muscles or spared. Soleus, medial gastrocnemius, and tibialis anterior are preferentially involved at the calf level.

[Analysis of survival and treatment outcome of patients with primary diffuse large B cell lymphoma in reproductive system]

Objective: To analyze clinical feature and treatment outcome of patients with primary diffuse large B cell lymphoma(DLBCL) in reproductive system. Methods: A total of 26 patients with DLBCL in reproductive system were retrospectively analyzed, and the clinical features, laboratory data were included in Kaplan-Meier and prognostic analysis. Results: In our center, the incidence of primary diffuse large B cell lymphoma in reproductive system was 3.5% in all DLBCL patients, and the median age was 62.0 years. Male are more common with unilateral testicular involvement, and 38.5% patients belong to Ⅲ and Ⅳstage while 84.6% patients belong to non-germinal center B cell-like subgroup. The overall response rate(ORR) for the whole group was 88.5%. The complete response rate was 76.9%. The 3, 5-year progression free survival rate was 70.5% and 62.7% , and the 3, 5-year overall survival rate was 83.5% and 69.6%, respectively. The most common recurrent sites were contralateral testis and central nervous system. Rituximab can improve the survival of patients and combined with contralateral irradiation can furtherly improve progression free survival of patients(P=0.047). Clinical stage, B symptom, IPI, the level of LDH, and CRP, age>60 years, and initial treatment outcome were predictive of overall survival. Conclusion: Primary diffuse large B cell lymphoma in reproductive system is a rare type of extranodal DLBCL which occurs in older men with aggressive features. The most common sites of recurrence were contralateral testis and central nervous system. Surgery, rituximab , radiotherapy and prophylactic intrathecal injection can improve the survival of patients and may be the first-line treatment.

Neuropeptide Y Y2 antagonist treated ovariectomized mice exhibit greater bone mineral density

Osteoporosis, a disease characterized by progressive bone loss and increased risk of fracture, often results from menopausal loss of estrogen in women. Neuropeptide Y has been shown to negatively regulate bone formation, with amygdala specific deletion of the Y2 receptor resulting in increased bone mass in mice. In this study, ovariectomized (OVX) mice were injected once daily with JNJ-31020028, a brain penetrant Y2 receptor small molecule antagonist to determine the effects on bone formation. Antagonist treated mice had reduced weight and showed increased whole-body bone mineral density compared to vehicle-injected mice. Micro computerized tomography (micro-CT) demonstrated increased vertebral trabecular bone volume, connectivity density and trabecular thickness. Femoral micro-CT analysis revealed increased bone volume within trabecular regions and greater trabecular number, without significant difference in other parameters or within cortical regions. A decrease was seen in serum P1NP, a measure used to confirm positive treatment outcomes in bisphosphonate treated patients. C-terminal telopeptide 1 (CTX-1), a blood biomarker of bone resorption, was decreased in treated animals. The higher bone mineral density observed following Y2 antagonist treatment, as determined by whole-body DEXA scanning, is indicative of either enhanced mineralization or reduced bone loss. Additionally, our findings that ex vivo treatment of bone marrow cells with the Y2 antagonist did not affect osteoblast and osteoclast formation suggests the inhibitor is not affecting these cells directly, and suggests a central role for compound action in this system. Our results support the involvement of Y2R signalling in bone metabolism and give credence to the hypothesis that selective pharmacological manipulation of Y2R may provide anabolic benefits for treating osteoporosis.

Effect Estimation in Point-Exposure Studies with Binary Outcomes and High-Dimensional Covariate Data - A Comparison of Targeted Maximum Likelihood Estimation and Inverse Probability of Treatment Weighting

Inverse probability of treatment weighting (IPW) and targeted maximum likelihood estimation (TMLE) are relatively new methods proposed for estimating marginal causal effects. TMLE is doubly robust, yielding consistent estimators even under misspecification of either the treatment or the outcome model. While IPW methods are known to be sensitive to near violations of the practical positivity assumption (e. g., in the case of data sparsity), the consequences of this violation in the TMLE framework for binary outcomes have been less widely investigated. As near practical positivity violations are particularly likely in high-dimensional covariate settings, a better understanding of the performance of TMLE is of particular interest for pharmcoepidemiological studies using large databases. Using plasmode and Monte-Carlo simulation studies, we evaluated the performance of TMLE compared to that of IPW estimators based on a point-exposure cohort study of the marginal causal effect of post-myocardial infarction statin use on the 1-year risk of all-cause mortality from the Clinical Practice Research Datalink. A variety of treatment model specifications were considered, inducing different degrees of near practical non-positivity. Our simulation study showed that the performance of the TMLE and IPW estimators were comparable when the dimension of the fitted treatment model was small to moderate; however, they differed when a large number of covariates was considered. When a rich outcome model was included in the TMLE, estimators were unbiased. In some cases, we found irregular bias and large standard errors with both methods even with a correctly specified high-dimensional treatment model. The IPW estimator showed a slightly better root MSE with high-dimensional treatment model specifications in our simulation setting. In conclusion, for estimation of the marginal expectation of the outcome under a fixed treatment, TMLE and IPW estimators employing the same treatment model specification may perform differently due to differential sensitivity to practical positivity violations; however, TMLE, being doubly robust, shows improved performance with richer specifications of the outcome model. Although TMLE is appealing for its double robustness property, such violations in a high-dimensional covariate setting are problematic for both methods.

Gigahertz-repetition-rate Tm-doped fiber laser passively mode-locked by optoacoustic effects in nanobore photonic crystal fiber

We report a Tm-doped soliton fiber laser passively mode-locked by intense optoacoustic interactions in a short length of solid-core silica photonic crystal fiber (PCF) with a nanobore in core-center. A repetition rate of 1.446 GHz pulse is achieved, corresponding to the 52nd harmonic of the 27.8 MHz cavity round-trip frequency. Strong optoacoustic interactions in this PCF-based, Tm-doped fiber laser ensure stable and repeatable gigahertz-rate pulse train generation at 1.85 μm wavelength, with a high supermode noise suppression ratio and low pulse timing jitter.

Studying noncollapsibility of the odds ratio with marginal structural and logistic regression models

One approach to quantifying the magnitude of confounding in observational studies is to compare estimates with and without adjustment for a covariate, but this strategy is known to be defective for noncollapsible measures such as the odds ratio. Comparing estimates from marginal structural and standard logistic regression models, the total difference between crude and conditional effects can be decomposed into the sum of a noncollapsibility effect and confounding bias. We provide an analytic approach to assess the noncollapsibility effect in a point-exposure study and provide a general formula for expressing the noncollapsibility effect. Next, we provide a graphical approach that illustrates the relationship between the noncollapsibility effect and the baseline risk, and reveals the behavior of the noncollapsibility effect for a range of different exposure and covariate effects. Various observations about noncollapsibility can be made from the different scenarios with or without confounding; for example, the magnitude of effect of the covariate plays a more important role in the noncollapsibility effect than does that of the effect of the exposure. In order to explore the noncollapsibility effect of the odds ratio in the presence of time-varying confounding, we simulated an observational cohort study. The magnitude of noncollapsibility was generally comparable to the effect in the point-exposure study in our simulation settings. Finally, in an applied example we demonstrate that collapsibility can have an important impact on estimation in practice.

Mouse Models of Frailty: an Emerging Field

Frailty is highly prevalent in the elderly, increasing the risk of poor outcomes that include falls, incident disability, hospitalization, and mortality. Thus, a great need exists to characterize the underlying mechanisms and ultimately identify strategies that prevent, delay, and even reverse frailty. Mouse models can provide insight into molecular mechanisms of frailty by reducing variability in lifestyle and genetic factors that can complicate interpretation of human clinical data. Frailty, generally recognized as a syndrome involving reduced homeostatic reserve in response to physiologic challenges and increasing susceptibility to poor health outcomes, is predominantly assessed using two independent strategies, integrated phenotype and deficit accumulation. The integrated phenotype defines frailty by the presentation of factors affecting functional capacity such as weight loss, exhaustion, low activity levels, slow gait, and grip strength. The deficit accumulation paradigm draws parameters from a greater range of physiological systems, such as the ability to perform daily activities, coordination and gait, mental components, physiological problems, and history and presence of medical morbidities. This strategic division also applies within the emerging field of mouse frailty models, with both methodologies showing usefulness in providing insight into physiologic mechanisms and testing interventions. Our review will explore the strategies used, caveats in methodology, and future directions in the application of animal models for the study of the frailty syndrome.

Effects of microwave ablation or its combination with whole-body chemotherapy on serum vascular endothelial growth factor levels in patients with stage IIIB/IV NSCLC

We aimed to analyze the changes of serum vascular endothelial growth factor (VEGF) before and after microwave ablation (MWA) in patients with stage IIIB-IV non-small cell lung cancer (NSCLC), and to observe the effects of MWA combined with chemotherapy on short-term therapeutic efficacy and long-term survival. Concentrations of serum VEGF in 20 healthy subjects were considered as controls. Changes of serum VEGF were detected by ELISA before and after MWA (1 and 7 days after treatment). Seven days after MWA, patients were divided into a combination chemotherapy group of 22 subjects and a MWA alone group of 18 subjects. Serum VEGF was measured 1 month after MWA and 4 cycles after chemotherapy (3 months) to evaluate term effects; and 1- and 2-year survival rates. Serum VEGF concentrations declined sharply 1 day after MWA, and were significantly different from the levels before treatment. Subsequently, VEGF rebounded 7 days after ablation, higher than that before treatment. At 1 and 3 months, serum VEGF levels in both treatment groups were remarkably lower than that before treatment; efficiency, or for the 1-year survival rate. However, the 2-year survival rates were significantly different between the two groups. We demonstrated that after MWA, the serum VEGF concentration undergoes a process of increasing, which might promote metastasis and recurrence of NSCLC. MWA combined with whole-body chemotherapy appears to be an effective method to increase the disease control rate, reduce the probability of metastasis and recurrence, and thus improve long-term survival.

On the role of marginal confounder prevalence - implications for the high-dimensional propensity score algorithm

PURPOSE

The high-dimensional propensity score algorithm attempts to improve control of confounding in typical treatment effect studies in pharmacoepidemiology and is increasingly being used for the analysis of large administrative databases. Within this multi-step variable selection algorithm, the marginal prevalence of non-zero covariate values is considered to be an indicator for a count variable's potential confounding impact. We investigate the role of the marginal prevalence of confounder variables on potentially caused bias magnitudes when estimating risk ratios in point exposure studies with binary outcomes.

METHODS

We apply the law of total probability in conjunction with an established bias formula to derive and illustrate relative bias boundaries with respect to marginal confounder prevalence.

RESULTS

We show that maximum possible bias magnitudes can occur at any marginal prevalence level of a binary confounder variable. In particular, we demonstrate that, in case of rare or very common exposures, low and high prevalent confounder variables can still have large confounding impact on estimated risk ratios.

CONCLUSIONS

Covariate pre-selection by prevalence may lead to sub-optimal confounder sampling within the high-dimensional propensity score algorithm. While we believe that the high-dimensional propensity score has important benefits in large-scale pharmacoepidemiologic studies, we recommend omitting the prevalence-based empirical identification of candidate covariates.

T-cell receptor ζ mRNA with an alternatively spliced 3' untranslated region is generated predominantly in the peripheral blood T cells of systemic lupus erythematosus patients

Abstract  To investigate the mechanism of the downregulation of T-cell receptor ζ chain (TCRζ) expression in the peripheral blood T cells (PBTs) of systemic lupus erythematosus (SLE) patients, we analyzed the 3' untranslated region (3'UTR) of TCRζ mRNA, because the 3'UTR in mRNA is responsible for posttranscriptional regulation. Use of the reverse transcriptase polymerase chain reaction (RT-PCR) to amplify the 917 bp TCRζ 3'UTR cDNA demonstrated that the short variant cDNA (355 bp), expressed as an alternatively spliced 3'UTR with 562-bp deletion, was predominated in the PBTs of 11 of 14 SLE patients, whereas mainly the wild-form cDNA (917 bp) was detected in the PBTs of seven negative controls (two systemic sclerosis patients, five normal controls) and in two T-cell line hybridomas. Semiquantitative PCR also revealed the predominant expression of the TCRζ mRNA with alternatively spliced 3'UTR (TCRζ mRNA/as-3'UTR), and a decreased expression of TCRζ mRNA with the wild form 3'UTR (TCRζ mRNA/w-3'UTR) in SLE T cells. However, there was no difference in the expression of the open reading frame (ORF) TCRζ mRNA between the negative controls and SLE patients. The TCRζ protein expression level according to Western blot analysis correlated well with that of TCRζ mRNA/w-3'UTR (r= 0.931) and reversibly with TCRζ mRNA/as-3'UTR (r=-0.614), but not with ORF TCRζ mRNA (r=-0.296). It can be concluded that the reduced expression of TCRζ mRNA/w-3'UTR and the predominant expression of TCRζ mRNA/as-3'UTR lead to downregulation of the TCRζ protein in SLE T cells.