Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 1.168
Filter
1.
Lancet ; 2024 May 20.
Article in English | MEDLINE | ID: mdl-38797180

ABSTRACT

National action plans enumerate many interventions as potential strategies to reduce the burden of bacterial antimicrobial resistance (AMR). However, knowledge of the benefits achievable by specific approaches is needed to inform policy making, especially in low-income and middle-income countries (LMICs) with substantial AMR burden and low health-care system capacity. In a modelling analysis, we estimated that improving infection prevention and control programmes in LMIC health-care settings could prevent at least 337 000 (95% CI 250 200-465 200) AMR-associated deaths annually. Ensuring universal access to high-quality water, sanitation, and hygiene services would prevent 247 800 (160 000-337 800) AMR-associated deaths and paediatric vaccines 181 500 (153 400-206 800) AMR-associated deaths, from both direct prevention of resistant infections and reductions in antibiotic consumption. These estimates translate to prevention of 7·8% (5·6-11·0) of all AMR-associated mortality in LMICs by infection prevention and control, 5·7% (3·7-8·0) by water, sanitation, and hygiene, and 4·2% (3·4-5·1) by vaccination interventions. Despite the continuing need for research and innovation to overcome limitations of existing approaches, our findings indicate that reducing global AMR burden by 10% by the year 2030 is achievable with existing interventions. Our results should guide investments in public health interventions with the greatest potential to reduce AMR burden.

2.
Sci Rep ; 14(1): 11658, 2024 05 22.
Article in English | MEDLINE | ID: mdl-38778036

ABSTRACT

Clinical application of cardiac magnetic resonance (CMR) is expanding but CMR assessment of LV diastolic function is still being validated. The purpose of this study was to validate assessments of left ventricular (LV) diastolic dysfunction (DD) using CMR by comparing with transthoracic echocardiography (TTE) performed on the same day. Patients with suspected or diagnosed cardiomyopathy (n = 63) and healthy volunteers (n = 24) were prospectively recruited and included in the study. CMR diastolic parameters were measured on cine images and velocity-encoded phase contrast cine images and compared with corresponding parameters measured on TTE. A contextual correlation feature tracking method was developed to calculate the mitral annular velocity curve. LV DD was classified by CMR and TTE following 2016 guidelines. Overall DD classification was 78.1% concordant between CMR and TTE (p < 0.0001). The trans-mitral inflow parameters correlated well between the two modalities (E, r = 0.78; A, r = 0.90; E/A, r = 0.82; all p < 0.0001) while the remaining diastolic parameters showed moderate correlation (e', r = 0.64; E/e', r = 0.54; left atrial volume index (LAVi), r = 0.61; all p < 0.0001). Classification of LV diastolic function by CMR showed good concordance with standardized grades established for TTE. CMR-based LV diastolic function may be integrated in routine clinical practice.Name of the registry: Technical Development of Cardiovascular Magnetic Resonance Imaging. Trial registration number: NCT00027170. Date of registration: November 26, 2001. URL of trial registry record: https://clinicaltrials.gov/ct2/show/NCT00027170.


Subject(s)
Diastole , Echocardiography , Magnetic Resonance Imaging, Cine , Humans , Male , Female , Echocardiography/methods , Middle Aged , Diastole/physiology , Magnetic Resonance Imaging, Cine/methods , Adult , Ventricular Dysfunction, Left/diagnostic imaging , Ventricular Dysfunction, Left/physiopathology , Aged , Ventricular Function, Left/physiology , Prospective Studies , Cardiomyopathies/diagnostic imaging , Cardiomyopathies/physiopathology
3.
Dev Comp Immunol ; : 105195, 2024 May 16.
Article in English | MEDLINE | ID: mdl-38762098

ABSTRACT

This study investigated the impact of hyperthermal (34 °C) and hypothermal (14 °C) stress on the expression of the octopamine/tyramine receptor (LvOA/TA-R) and immune parameters in Litopenaeus vannamei, which is a species critical to the aquaculture industry. Given the sensitivity of aquatic organisms to climate change, understanding the physiological and immune responses of L. vannamei to temperature variations is essential for developing strategies to mitigate adverse effects. This research focuses on the immune response and expression changes of LvOA/TA-R under acute (0.5, 1, and 2 hours) and chronic (24, 72, and 168 hours) thermal stress conditions. Our findings reveal that thermal stress induces changes in LvOA/TA-R expression and impacts immune responses. Immune parameters such as total haemocyte count, differential haemocyte count, phenoloxidase activity, respiratory bursts, lysozyme activity, clearance efficiency, and phagocytosis exhibited a general trend of significant decline under the stress conditions. LvOA/TA-R had a higher expression in haemocyte under hyperthermal stress. The study elucidated that thermal stress modifies the expression of the LvOA/TA-R and diminishes immune functionality in L. vannamei, underscoring the potential influence of climate change on industry.

4.
Nat Commun ; 15(1): 3791, 2024 May 06.
Article in English | MEDLINE | ID: mdl-38710704

ABSTRACT

Fas-associated protein with death domain (FADD), procaspase-8, and cellular FLICE-inhibitory proteins (cFLIP) assemble through death-effector domains (DEDs), directing death receptor signaling towards cell survival or apoptosis. Understanding their three-dimensional regulatory mechanism has been limited by the absence of atomic coordinates for their ternary DED complex. By employing X-ray crystallography and cryogenic electron microscopy (cryo-EM), we present the atomic coordinates of human FADD-procaspase-8-cFLIP complexes, revealing structural insights into these critical interactions. These structures illustrate how FADD and cFLIP orchestrate the assembly of caspase-8-containing complexes and offer mechanistic explanations for their role in promoting or inhibiting apoptotic and necroptotic signaling. A helical procaspase-8-cFLIP hetero-double layer in the complex appears to promote limited caspase-8 activation for cell survival. Our structure-guided mutagenesis supports the role of the triple-FADD complex in caspase-8 activation and in regulating receptor-interacting protein kinase 1 (RIPK1). These results propose a unified mechanism for DED assembly and procaspase-8 activation in the regulation of apoptotic and necroptotic signaling across various cellular pathways involved in development, innate immunity, and disease.


Subject(s)
Apoptosis , CASP8 and FADD-Like Apoptosis Regulating Protein , Caspase 8 , Fas-Associated Death Domain Protein , Humans , CASP8 and FADD-Like Apoptosis Regulating Protein/metabolism , CASP8 and FADD-Like Apoptosis Regulating Protein/genetics , CASP8 and FADD-Like Apoptosis Regulating Protein/chemistry , Caspase 8/metabolism , Cryoelectron Microscopy , Crystallography, X-Ray , Fas-Associated Death Domain Protein/metabolism , Fas-Associated Death Domain Protein/genetics , HEK293 Cells , Models, Molecular , Protein Binding , Protein Domains , Receptor-Interacting Protein Serine-Threonine Kinases/metabolism , Receptor-Interacting Protein Serine-Threonine Kinases/genetics , Signal Transduction
5.
Cell Calcium ; 121: 102895, 2024 Apr 30.
Article in English | MEDLINE | ID: mdl-38703416

ABSTRACT

Liver fibrosis is characterized by excessive deposition of extracellular matrix (ECM) as a wound healing process. Activated hepatic stellate cells (HpSCs) are the major producer of the ECM and play a central role in liver fibrogenesis. It has been widely accepted that elimination of activated HpSCs or reversion to a quiescent state can be a feasible strategy for resolving the disease, further highlighting the urgent need for novel therapeutic targets. Calreticulin (CRT) is a molecular chaperone that normally resides in the endoplasmic reticulum (ER), important in protein folding and trafficking through the secretory pathway. CRT also plays a critical role in calcium (Ca2+) homeostasis, with its Ca2+ storage capacity. In the current study, we aimed to demonstrate its function in directing HpSC activation. In a mouse liver injury model, CRT was up-regulated in HpSCs. In cellular experiments, we further showed that this activation was through modulating the canonical TGF-ß signaling. As down-regulation of CRT in HpSCs elevated intracellular Ca2+ levels through a form of Ca2+ influx, named store-operated Ca2+ entry (SOCE), we examined whether moderating SOCE affected TGF-ß signaling. Interestingly, blocking SOCE had little effect on TGF-ß-induced gene expression. In contrast, inhibition of ER Ca2+ release using the inositol trisphosphate receptor inhibitor 2-APB increased TGF-ß signaling. Treatment with 2-APB did not alter SOCE but decreased intracellular Ca2+ at the basal level. Indeed, adjusting Ca2+ concentrations by EGTA or BAPTA-AM chelation further enhanced TGF-ß-induced signaling. Our results suggest a crucial role of CRT in the liver fibrogenic process through modulating Ca2+ concentrations and TGF-ß signaling in HpSCs, which may provide new information and help advance the current discoveries for liver fibrosis.

6.
Lifetime Data Anal ; 2024 May 28.
Article in English | MEDLINE | ID: mdl-38805095

ABSTRACT

Risk stratification based on prediction models has become increasingly important in preventing and managing chronic diseases. However, due to cost- and time-limitations, not every population can have resources for collecting enough detailed individual-level information on a large number of people to develop risk prediction models. A more practical approach is to use prediction models developed from existing studies and calibrate them with relevant summary-level information of the target population. Many existing studies were conducted under the population-based case-control design. Gail et al. (J Natl Cancer Inst 81:1879-1886, 1989) proposed to combine the odds ratio estimates obtained from case-control data and the disease incidence rates from the target population to obtain the baseline hazard function, and thereby the pure risk for developing diseases. However, the approach requires the risk factor distribution of cases from the case-control studies be same as the target population, which, if violated, may yield biased risk estimation. In this article, we propose two novel weighted estimating equation approaches to calibrate the baseline risk by leveraging the summary information of (some) risk factors in addition to disease-free probabilities from the targeted population. We establish the consistency and asymptotic normality of the proposed estimators. Extensive simulation studies and an application to colorectal cancer studies demonstrate the proposed estimators perform well for bias reduction in finite samples.

7.
Chemosphere ; 358: 142124, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38677614

ABSTRACT

Metformin, the most commonly prescribed drug for the treatment of diabetes, is increasingly used during pregnancy to address various disorders such as diabetes, obesity, preeclampsia, and metabolic diseases. However, its impact on neocortex development remains unclear. Here, we investigated the direct effects of metformin on neocortex development, focusing on ERK and p35/CDK5 regulation. Using a pregnant rat model, we found that metformin treatment during pregnancy induces small for gestational age (SGA) and reduces relative cortical thickness in embryos and neonates. Additionally, we discovered that metformin inhibits neural progenitor cell proliferation in the sub-ventricular zone (SVZ)/ventricular zone (VZ) of the developing neocortex, a process possibly mediated by ERK inactivation. Furthermore, metformin induces neuronal apoptosis in the SVZ/VZ area of the developing neocortex. Moreover, metformin retards neuronal migration, cortical lamination, and differentiation, potentially through p35/CDK5 inhibition in the developing neocortex. Remarkably, compensating for p35 through in utero electroporation partially rescues metformin-impaired neuronal migration and development. In summary, our study reveals that metformin disrupts neocortex development by inhibiting neuronal progenitor proliferation, neuronal migration, cortical layering, and cortical neuron maturation, likely via ERK and p35/CDK5 inhibition. Consequently, our findings advocate for caution in metformin usage during pregnancy, given its potential adverse effects on fetal brain development.


Subject(s)
Cell Proliferation , Cyclin-Dependent Kinase 5 , Metformin , Neocortex , Metformin/pharmacology , Animals , Female , Pregnancy , Neocortex/drug effects , Cyclin-Dependent Kinase 5/metabolism , Rats , Cell Proliferation/drug effects , Neural Stem Cells/drug effects , Neural Stem Cells/metabolism , MAP Kinase Signaling System/drug effects , Neurons/drug effects , Rats, Sprague-Dawley , Cell Differentiation/drug effects , Neurogenesis/drug effects , Cell Movement/drug effects , Apoptosis/drug effects , Signal Transduction/drug effects
8.
Genet Epidemiol ; 2024 Apr 12.
Article in English | MEDLINE | ID: mdl-38606632

ABSTRACT

Genetic factors play a fundamental role in disease development. Studying the genetic association with clinical outcomes is critical for understanding disease biology and devising novel treatment targets. However, the frequencies of genetic variations are often low, making it difficult to examine the variants one-by-one. Moreover, the clinical outcomes are complex, including patients' survival time and other binary or continuous outcomes such as recurrences and lymph node count, and how to effectively analyze genetic association with these outcomes remains unclear. In this article, we proposed a structured test statistic for testing genetic association with mixed types of survival, binary, and continuous outcomes. The structured testing incorporates known biological information of variants while allowing for their heterogeneous effects and is a powerful strategy for analyzing infrequent genetic factors. Simulation studies show that the proposed test statistic has correct type I error and is highly effective in detecting significant genetic variants. We applied our approach to a uterine corpus endometrial carcinoma study and identified several genetic pathways associated with the clinical outcomes.

9.
Article in English | MEDLINE | ID: mdl-38653906

ABSTRACT

PURPOSE: Mammographic density phenotypes, adjusted for age and body mass index (BMI), are strong predictors of breast cancer risk. BMI is associated with mammographic density measures, but the role of circulating sex hormone concentrations is less clear. We investigated the relationship between BMI, circulating sex hormone concentrations, and mammographic density phenotypes using Mendelian randomization (MR). METHODS: We applied two-sample MR approaches to assess the association between genetically predicted circulating concentrations of sex hormones [estradiol, testosterone, sex hormone-binding globulin (SHBG)], BMI, and mammographic density phenotypes (dense and non-dense area). We created instrumental variables from large European ancestry-based genome-wide association studies and applied estimates to mammographic density phenotypes in up to 14,000 women of European ancestry. We performed analyses overall and by menopausal status. RESULTS: Genetically predicted BMI was positively associated with non-dense area (IVW: ß = 1.79; 95% CI = 1.58, 2.00; p = 9.57 × 10-63) and inversely associated with dense area (IVW: ß = - 0.37; 95% CI = - 0.51,- 0.23; p = 4.7 × 10-7). We observed weak evidence for an association of circulating sex hormone concentrations with mammographic density phenotypes, specifically inverse associations between genetically predicted testosterone concentration and dense area (ß = - 0.22; 95% CI = - 0.38, - 0.053; p = 0.009) and between genetically predicted estradiol concentration and non-dense area (ß = - 3.32; 95% CI = - 5.83, - 0.82; p = 0.009), although results were not consistent across a range of MR approaches. CONCLUSION: Our findings support a positive causal association between BMI and mammographic non-dense area and an inverse association between BMI and dense area. Evidence was weaker and inconsistent for a causal effect of circulating sex hormone concentrations on mammographic density phenotypes. Based on our findings, associations between circulating sex hormone concentrations and mammographic density phenotypes are weak at best.

10.
Int J Rehabil Res ; 47(2): 129-134, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38587088

ABSTRACT

This study aimed to translate and validate the traditional Chinese version of the Community Integration Questionnaire-Revised (TC-CIQ-R) in patients with traumatic brain injury (TBI). We included participants aged ≥20 years and diagnosed as having TBI for ≥6 months from neurosurgical clinics. The 18-item TC-CIQ-R, Participation Measure - 3 Domains, 4 Dimensions (PM-3D4D), Extended Glasgow Outcome Scale (GOSE), and Taiwanese Quality of Life After Brain Injury (TQOLIBRI) were completed. The sample included 180 TBI survivors (54% male, mean age 47 years) of whom 87% sustained a mild TBI. Exploratory factor analysis extracted four factors - home integration, social integration, productivity, and electronic social networking - which explained 63.03% of the variation, after discarding the tenth item with a factor loading of 0.25. For criterion-related validity, the TC-CIQ-R was significantly correlated with the PM-3D4D; convergent validity was exhibited by demonstrating the associations between the TC-CIQ-R and TQOLIBRI. Known-group validity testing revealed significant differences in the subdomain and total scores of the TC-CIQ-R between participants with a mean GOSE score of ≤6 and >7 (all P  < 0.001). The TC-CIQ-R exhibited acceptable Cronbach's α values (0.68-0.88). We suggest the 17-item TC-CIQ-R as a valid tool for rehabilitation professionals, useful for both clinical practice and research in assessing community integration levels following TBI.


Subject(s)
Brain Injuries, Traumatic , Community Integration , Psychometrics , Quality of Life , Humans , Male , Female , Brain Injuries, Traumatic/rehabilitation , Brain Injuries, Traumatic/psychology , Middle Aged , Adult , Surveys and Questionnaires , Factor Analysis, Statistical , Taiwan , Reproducibility of Results , Glasgow Outcome Scale , Survivors/psychology , Translations , Social Integration , Aged
11.
J Pharm Pharm Sci ; 27: 12398, 2024.
Article in English | MEDLINE | ID: mdl-38577255

ABSTRACT

Bioequivalence (BE) studies are considered the standard for demonstrating that the performance of a generic drug product in the human body is sufficiently similar to that of its comparator product. The objective of this article is to describe the recommendations from participating Bioequivalence Working Group for Generics (BEWGG) members of the International Pharmaceutical Regulators Programme (IPRP) regarding the conduct and acceptance criteria for BE studies of immediate release solid oral dosage forms. A survey was conducted among BEWGG members regarding their BE recommendations and requirements related to study subjects, study design, sample size, single or multiple dose administration, study conditions (fasting or fed), analyte to be measured, selection of product strength, drug content, handling of endogenous substances, BE acceptance criteria, and additional design aspects. All members prefer conducting single dose cross-over designed studies in healthy subjects with a minimum of 12 subjects and utilizing the parent drug data to assess BE. However, differences emerged among the members when the drug's pharmacokinetics and pharmacodynamics become more complex, such that the study design (e.g., fasting versus fed conditions) and BE acceptance criteria (e.g., highly variable drugs, narrow therapeutic index drugs) may be affected. The survey results and discussions were shared with the ICH M13 Expert Working Group (EWG) and played an important role in identifying and analyzing gaps during the harmonization process. The draft ICH M13A guideline developed by the M13 EWG was endorsed by ICH on 20 December 2022, under Step 2.


Subject(s)
Drugs, Generic , Research Design , Humans , Therapeutic Equivalency
12.
Front Genet ; 15: 1345559, 2024.
Article in English | MEDLINE | ID: mdl-38544800

ABSTRACT

T-cell receptor (TCR) plays critical roles in recognizing antigen peptides and mediating adaptive immune response against disease. High-throughput technologies have enabled the sequencing of TCR repertoire at the single nucleotide level, allowing researchers to characterize TCR sequences with high resolutions. The TCR sequences provide important information about patients' adaptive immune system, and have the potential to improve clinical outcome prediction. However, it is challenging to incorporate the TCR repertoire data for prediction, because the data is unstructured, highly complex, and TCR sequences vary widely in their compositions and abundances across different individuals. We introduce TCRpred, an analytic tool for incorporating TCR repertoire for clinical outcome prediction. The TCRpred is able to utilize features that can be extracted from the TCR amino acid sequences, as well as features that are hidden in the TCR amino acid sequences and are hard to extract. Simulation studies show that the proposed approach has a good performance in predicting clinical outcome and tends to be more powerful than potential alternative approaches. We apply the TCRpred to real cancer datasets and demonstrate its practical utility in clinical outcome prediction.

14.
J Neurosci ; 44(18)2024 May 01.
Article in English | MEDLINE | ID: mdl-38438260

ABSTRACT

Locomotion allows us to move and interact with our surroundings. Spinal networks that control locomotion produce rhythm and left-right and flexor-extensor coordination. Several glutamatergic populations, Shox2 non-V2a, Hb9-derived interneurons, and, recently, spinocerebellar neurons have been proposed to be involved in the mouse rhythm generating networks. These cells make up only a smaller fraction of the excitatory cells in the ventral spinal cord. Here, we set out to identify additional populations of excitatory spinal neurons that may be involved in rhythm generation or other functions in the locomotor network. We use RNA sequencing from glutamatergic, non-glutamatergic, and Shox2 cells in the neonatal mice from both sexes followed by differential gene expression analyses. These analyses identified transcription factors that are highly expressed by glutamatergic spinal neurons and differentially expressed between Shox2 neurons and glutamatergic neurons. From this latter category, we identified the Lhx9-derived neurons as having a restricted spinal expression pattern with no Shox2 neuron overlap. They are purely glutamatergic and ipsilaterally projecting. Ablation of the glutamatergic transmission or acute inactivation of the neuronal activity of Lhx9-derived neurons leads to a decrease in the frequency of locomotor-like activity without change in coordination pattern. Optogenetic activation of Lhx9-derived neurons promotes locomotor-like activity and modulates the frequency of the locomotor activity. Calcium activities of Lhx9-derived neurons show strong left-right out-of-phase rhythmicity during locomotor-like activity. Our study identifies a distinct population of spinal excitatory neurons that regulates the frequency of locomotor output with a suggested role in rhythm-generation in the mouse alongside other spinal populations.


Subject(s)
Interneurons , LIM-Homeodomain Proteins , Locomotion , Spinal Cord , Transcription Factors , Animals , Interneurons/physiology , Mice , LIM-Homeodomain Proteins/genetics , LIM-Homeodomain Proteins/metabolism , Locomotion/physiology , Spinal Cord/physiology , Spinal Cord/cytology , Transcription Factors/genetics , Transcription Factors/metabolism , Male , Female , Glutamic Acid/metabolism , Animals, Newborn , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism
15.
bioRxiv ; 2024 Feb 27.
Article in English | MEDLINE | ID: mdl-38464010

ABSTRACT

While deep brain stimulation (DBS) is widely employed for managing motor symptoms in Parkinson's disease (PD), its exact circuit mechanisms remain controversial. To identify the neural targets affected by therapeutic DBS in PD, we analyzed DBS-evoked whole brain activity in female hemi-parkinsonian rats using function magnetic resonance imaging (fMRI). We delivered subthalamic nucleus (STN) DBS at various stimulation pulse repetition rates using optogenetics, allowing unbiased examinations of cell-type specific STN feed-forward neural activity. Unilateral STN optogenetic stimulation elicited pulse repetition rate-dependent alterations of blood-oxygenation-level-dependent (BOLD) signals in SNr (substantia nigra pars reticulata), GP (globus pallidus), and CPu (caudate putamen). Notably, these manipulations effectively ameliorated pathological circling behavior in animals expressing the kinetically faster Chronos opsin, but not in animals expressing ChR2. Furthermore, mediation analysis revealed that the pulse repetition rate-dependent behavioral rescue was significantly mediated by optogenetically induced activity changes in GP and CPu, but not in SNr. This suggests that the activation of GP and CPu are critically involved in the therapeutic mechanisms of STN DBS.

16.
J Dent Sci ; 19(1): 387-396, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38303827

ABSTRACT

Background/purpose: It has been known that genetic factors influence orthodontic tooth movement, however, scientific research on humans is lacking. Therefore, this study aimed to investigate dynamic changes to the genetic profile in human periodontal ligament (PDL) tissue and cytokine release in gingival crevicular fluid (GCF) during the first 28 days of orthodontic treatment. Materials and methods: Fifteen teeth from three patients were recruited. Full-mouth fixed appliances with extraction of four premolars and one maxillary third molar was planned for orthodontic treatment. GCF collection and tooth extraction were performed following force application for 0, 1, 3, 7, and 28 days. GCF was analyzed using multiplex immunoassay for 27 cytokines. PDL tissue was collected after extraction and submitted for RNA exome-sequencing using Illumina sequencing platform. Further analysis of differentially expressed genes (DEGs), gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, and heatmaps were conducted. Results: GCF cytokine levels varied among three patients; some patients exhibited a peak cytokine level on Day 0 whereas others did so on Days 1-3. In RNA exome sequencing data, GO and KEGG analyses showed that genes associated with sensory receptors were upregulated on Day 1, genes involved in bone remodeling were upregulated on Days 3 and 28, and genes related to osteoclast differentiation were upregulated on Day 7. Conclusion: RNA sequencing data demonstrate that the specific types of genes are expressed at different time points, whereas the data on cytokine changes show a large variation in concentration levels and dynamic change patterns among the patients.

17.
Eur J Pharm Sci ; 195: 106718, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38316168

ABSTRACT

To ensure therapeutic equivalence between the long-acting injectable (LAI) products, additional PK metrics other than Cmax and AUC were considered necessary. However, regarding the selection of additional PK metrics for bioequivalence (BE) assessment of exenatide LAI, a discrepancy existed between EMA's and USFDA's product-specific guidance. The EMA recommends that both the maximum plasma concentration in the initial-release phase (Cmax,1) and the extended-release phase (Cmax,2) should be determined. Nevertheless, the USFDA recommends the use of the partial area under the curve (i.e., the area under the curve from week 4 to the last sampling point; pAUC4w-t). The focus of this study was to compare the sensitivity of different PK metrics, including Cmax,1, Cmax,2, pAUC4w-t, early and late pAUC metrics truncated at different time points (three, four, five, six and seven weeks), to formulation-related parameters and pharmacodynamic (PD) markers of glycemic control. A sensitivity analysis was conducted using the published PK/PD model of exenatide LAI. The results indicated that Cmax,1 and Cmax,2 exhibited comparable sensitivities. AUC4w-t was sensitive to changes in detecting the differences in formulation-related parameters and PD markers of glycemic control, but did not provide superior sensitivity performance compared to Cmax,1 and Cmax,2. Among all tested PK metrics, AUC7w-t was found to be the most sensitive. The optimal cut-off time point for the pAUC should be set at the time of maximum plasma concentration in the extended-release phase (approximately 6-7 weeks). These results may provide useful insights into the selection of appropriate PK metrics for BE determination of exenatide LAI.


Subject(s)
Therapeutic Equivalency , United States , Exenatide , United States Food and Drug Administration , Area Under Curve , Cross-Over Studies
18.
Stat Med ; 43(9): 1790-1803, 2024 Apr 30.
Article in English | MEDLINE | ID: mdl-38402690

ABSTRACT

Missing data in covariates can result in biased estimates and loss of power to detect associations. We consider Cox regression in which some covariates are subject to missing. The inverse probability weighted approach is often applied to regression analysis with missing covariates. Inverse probability weighted estimators typically are less efficient than likelihood-based estimators, but in general are more robust against model misspecification. In this article, we propose a robust best linear weighted estimator for Cox regression with missing covariates. Our proposed estimator is the projection of the simple inverse probability weighted estimator onto the orthogonal complement of the score space based on a working regression model of the observed data. The efficiency gain is from the use of the association between the survival outcome variable and the available covariates, which is the working regression model. The asymptotic distribution is derived, and the finite sample performance of the proposed estimator is examined via extensive simulation studies. The methods are applied to a colorectal cancer study to assess the association of the microsatellite instability status with colorectal cancer-specific mortality.


Subject(s)
Colorectal Neoplasms , Models, Statistical , Humans , Likelihood Functions , Survival Analysis , Probability , Regression Analysis , Computer Simulation
19.
Genet Epidemiol ; 48(4): 164-189, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38420714

ABSTRACT

Gene-environment (GxE) interactions play a crucial role in understanding the complex etiology of various traits, but assessing them using observational data can be challenging due to unmeasured confounders for lifestyle and environmental risk factors. Mendelian randomization (MR) has emerged as a valuable method for assessing causal relationships based on observational data. This approach utilizes genetic variants as instrumental variables (IVs) with the aim of providing a valid statistical test and estimation of causal effects in the presence of unmeasured confounders. MR has gained substantial popularity in recent years largely due to the success of genome-wide association studies. Many methods have been developed for MR; however, limited work has been done on evaluating GxE interaction. In this paper, we focus on two primary IV approaches: the two-stage predictor substitution and the two-stage residual inclusion, and extend them to accommodate GxE interaction under both the linear and logistic regression models for continuous and binary outcomes, respectively. Comprehensive simulation study and analytical derivations reveal that resolving the linear regression model is relatively straightforward. In contrast, the logistic regression model presents a considerably more intricate challenge, which demands additional effort.


Subject(s)
Gene-Environment Interaction , Genome-Wide Association Study , Mendelian Randomization Analysis , Humans , Logistic Models , Linear Models , Polymorphism, Single Nucleotide , Models, Genetic , Genetic Variation , Computer Simulation
20.
Phys Chem Chem Phys ; 26(8): 7190-7202, 2024 Feb 22.
Article in English | MEDLINE | ID: mdl-38349743

ABSTRACT

Light-triggered molecular switches are extensively researched for their applications in medicine, chemistry and material science and, if combined, particularly for their use in multifunctional smart materials, for which orthogonally, i.e. individually, addressable photoswitches are needed. In such a multifunctional mixture, the switching properties, efficiencies and the overall performance may be impaired by undesired mutual dependences of the photoswitches on each other. Within this study, we compare the performance of the pure photoswitches, namely an azobenzene derivative (Azo) and a donor-acceptor Stenhouse adduct (DASA), with the switching properties of their mixture using time-resolved temperature-dependent UV/VIS absorption spectroscopy, time-resolved IR absorption spectroscopy at room temperature and quantum mechanical calculations to determine effective cross sections, switching kinetics as well as activation energies of thermally induced steps. We find slightly improved effective cross sections, percentages of switched molecules and no increased activation barriers of the equimolar mixture compared to the single compounds. Thus, the studied mixture Azo + DASA is very promising for future applications in multifunctional smart materials.

SELECTION OF CITATIONS
SEARCH DETAIL
...