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Age-induced changes in skeletal muscle mitochondrial DNA synthesis, quantity, and quality in genetically unique rats.

Mitochondrial genomic integrity is a key element of physiological processes and health. Changes in the half-life of the mitochondrial genome are implicated in the generation and accumulation of age-induced mitochondrial DNA (mtDNA) mutations, which are implicated in skeletal muscle aging and sarcopenia. There are conflicting data on the half-life of mtDNA, and there is limited information on how aging affects half-life in skeletal muscle. We hypothesized that skeletal muscle mtDNA synthesis rates would decrease with age in both female and male rats concomitant with changes in mtDNA integrity reflected in mtDNA copy number and mutation frequency. We measured mitochondrial genome half-life using stable isotope labeling over a period of 14 days and assessed mtDNA copy number and deletion mutation frequency using digital PCR in the quadriceps muscle of 9-month-old and 26-month-old male and female OKC-HET rats. We found a significant age-related increase in mtDNA half-life, from 132 days at 9 months to 216 days at 26 months of age in OKC-HET quadriceps. Concomitant with the increase in mtDNA half-life, we found an age-related increase in mtDNA deletion mutation frequency in both male and female rats. Notably, 26-month-old female rats had a lower mutation frequency than male rats, and there were no changes in mtDNA copy number with sex, age, or mitochondrial genotype. These data reveal several key findings: (1) mtDNA turnover in rat skeletal muscle decreases with age, (2) mtDNA half-lives in skeletal muscle are approximately an order of magnitude longer than what is reported for other tissues, and (3) muscle mtDNA turnover differs significantly from the turnover of other mitochondrial macromolecules including components of the mitochondrial nucleoid. These findings provide insight into the factors driving age-induced mtDNA mutation accumulation, which contribute to losses of mitochondrial genomic integrity and may play a role in skeletal muscle dysfunction.

Animals

A third-generation, high-affinity biparatopic anti-tau antibody inhibits intracellular tau aggregation seeded by Alzheimer's brain extracts.

BACKGROUND: Tau immunotherapy has recently shown clinical promise but required high dosing. We developed NIDB-3101, a novel third-generation, high-affinity anti-tau biparatopic antibody designed for superior tau binding, aggregation inhibition, and extended half-life. METHODS: NIDB-3101 binds tau's microtubule-binding region and C-terminal domains. Various binding and cellular functional assays using recombinants, but more importantly human AD extracts were used to assess NIDB-3101 benefits. Half-life mutations impact was assessed via FcRn binding and cellular assays recycling. RESULTS: NIDB-3101 exhibited sub-nanomolar affinity, binding a broad spectrum of pathological tau species in AD homogenates, inhibited AD extracts-induced cellular effect compared to benchmark antibodies. Mutations enhanced hFcRn-mediated cellular recycling. CONCLUSIONS: NIDB-3101 captures a broad spectrum of pathological tau species leading to strong cellular efficacy using human AD extracts, supporting further clinical development as a potential disease-modifying therapy for AD and related tauopathies.

tau Proteins

Pharmacokinetic Differences Between Fast-Acting, Standard, and Placebo Cannabis Edibles.

INTRODUCTION: Edibles have become the second-most used cannabis product in legal U.S. states, wherein 64% of cannabis consumers reported using edibles within the past year. Among expansions to the legal cannabis industry are the newly marketed "fast-acting" edible compounds, which may address many of the issues associated with edible use related to overdose and dose management. The study hypotheses were that fast-acting edibles would reach peak concentration significantly faster than standard edibles and placebo edibles. MATERIALS AND METHODS: Twenty participants completed three arms within-subjects designed study to test hypotheses. The three arms were ingestion of a (1) fast-acting edible, (2) a standard edible, and (3) a Δ9-tetrahydrocannabinol (THC) terpene-derived placebo edible that was indistinguishable from the two THC-containing edibles. Blood plasma was analyzed for the presence of THC and THC analytes. The pharmacokinetic parameters tested were time to max concentration (Tmax), maximum concentration (Cmax), terminal half-life (t1/2), and area under the curve (AUC). RESULTS: Results supported study hypotheses in that Tmax was significantly faster for the fast-acting edible, observed 30 min post-ingestion and, on average, 30 min earlier than the Tmax for the standard edible. There were no significant differences between the fast-acting and standard edibles on Cmax, t1/2, and AUC; however, both the fast-acting and standard edibles were significantly different compared with the placebo across all pharmacokinetic parameters. DISCUSSION: The results indicate that the microencapsulation technology used to create the fast-acting edible enabled analyte concentrations to peak significantly faster compared to the standard and placebo edibles.

Humans

Melatonin Levels in 89 Individuals With Smith Magenis Syndrome.

In patients with Smith-Magenis syndrome (SMS), an inverted circadian rhythm of melatonin (MT) contributes to the sleep disturbance. Standard treatment of sleep disturbance with MT often leads to extremely high daytime MT levels, resulting in even more sleep disorders. We therefore retrospectively evaluated the MT data of 89 SMS patients. Mean MT levels in participants on exogenous MT were significantly higher than in participants that did not use MT (p&#x2009;=&#x2009;<&#x2009;0.0001). In 9 participants with very high MT levels, these dropped significantly after discontinuation of exogenous MT (p&#x2009;=&#x2009;0.0037). In 12 participants, MT levels were significantly higher after MT therapy start compared to MT levels before MT start (p&#x2009;=&#x2009;0.028). MT is catabolized principally by the CYP1A2 enzyme, with a half-life of about 40&#x2009;min. CYP1A2 genotyping was performed in five participants with high MT levels during MT use. Although clinically suspected to be a poor CYP1A2 metabolizer, all five turned out to have haplotype CYP1A2*1F, which is associated with increased enzyme activity. This shows that genotyping of CYP1A2 is not suitable to estimate the level of CYP1A2 enzyme activity. When prescribing MT, it is strongly recommended to measure a MT level prior to treatment in order to determine the dose to be given. Checks of the MT level during treatment are necessary due to the frequent occurrence of poor CYP1A2 metabolism. Since CYP1A2 genotyping does not provide adequate information about the level of CYP1A2 enzyme activity, we propose a simple way to determine CYP1A2 phenotype.

Humans

Iron-Deprivation Liposomes for Cancer Therapy.

Targeting iron homeostasis in tumor cells represents a promising anticancer strategy, as iron plays essential roles in tumor growth, invasion, and metastasis. Although deferoxamine can effectively chelate iron, its clinical application is limited by poor membrane permeability, short half-life, and lack of targeting capability. To overcome these challenges, we designed and synthesized a family of DFO-bearing lipids by modifying the molecule with dual fatty acid chains of varying lengths, and co-assembled them with auxiliary lipids via microfluidics to construct "iron-deprivation" liposomes. Among them, the medium-chain DFO-C12-liposomes exhibited the highest cellular uptake, iron-deprivation efficiency, and anticancer activity in vitro, markedly depleting mitochondrial iron, disrupting Fe-S cluster synthesis, suppressing mitochondrial respiration, and inducing autophagy. Furthermore, DFO-C12-liposomes efficiently coordinated Mn2 + via DFO-Mn2 + chelation, providing MRI capability while inducing iron deprivation-mediated ferroptosis. In addition, the iron-deprivation liposomes can encapsulate anticancer drugs such as doxorubicin, leading to an enhanced antitumor effect through the combination of iron deprivation and chemotherapy for osteosarcoma treatment. In summary, the "iron-deprivation" liposomes integrate iron chelation, imaging functionality, and chain-length-dependent cellular uptake into a versatile nanoplatform for regulating tumor iron homeostasis and achieving enhanced antitumor efficacy through multimodal therapeutic strategies.

alkyl chain&#x2010;length engineering

Assessment of mRNA Decay and Calculation of Codon Occurrence to mRNA Stability Correlation Coefficients after 5-EU Metabolic Labeling.

mRNA translation and decay are tightly connected. This chapter describes a method to assess the influence of each codon identity on mRNA stability in cultured cells. The technique involves metabolic labeling of the nascent mRNAs by addition of the nucleoside analog 5-ethynyluridine (5-EU), purification of the RNA at different time-points after chase of the 5-EU, then biotinylation with Click chemistry, pull-down, and sequencing. The transcripts' half-lives are calculated from the expression level of each mRNA at the different time-points. Finally, the method describes the calculation of the Codon occurrence to mRNA Stability correlation Coefficient, or CSC, as a correlation between the codon occurrence in a transcript and the transcript half-life, for each codon.

RNA Stability

Netupitant versus aprepitant: model-predicted neurokinin-1 receptor occupancy and implications for long-delayed nausea and vomiting prevention.

PURPOSE: Nausea and vomiting beyond 5&#xa0;days after emetogenic chemotherapy or antibody-drug conjugate (ADC) therapy are common, yet the role of neurokinin-1 (NK1) receptor antagonists in this setting remains underrecognized. We used pharmacokinetic/pharmacodynamic (PK/PD) modeling to estimate the NK1 receptor occupancy (RO), a proxy for clinical efficacy, for up to 20&#xa0;days after a single 300&#xa0;mg dose of oral netupitant, 3-day oral aprepitant (125&#xa0;mg on day 1; 80&#xa0;mg on days 2-3), or a single 165&#xa0;mg dose of oral aprepitant. METHODS: Data from previous PK studies were analyzed by compartmental modeling. Positron emission tomography studies assessing striatal NK1 RO were used to develop maximum drug effect PD models, which were fitted to NK1 RO data as a function of plasma concentrations. RESULTS: Model predicted NK1 RO exceeded 90% at 3&#xa0;h for all treatments. Thereafter, RO declined more gradually with netupitant (76%, 70%, 60%, and 21% on days 5, 7, 10, and 20, respectively) than with 3-day aprepitant (81%, 39%, 3%, and negligible) or single-dose aprepitant (45%, 10%, <&#x2009;1%, and negligible). The half-life of netupitant was ~&#x2009;6.1 times longer than aprepitant's. Netupitant plasma concentration remained above the effective concentration for 50% NK1 RO (EC50) through day 10, whereas aprepitant concentrations fell below the EC50 by ~&#x2009;days 7 and 5 after repeated and single dosing, respectively. CONCLUSIONS: Single-dose netupitant maintained NK1 RO substantially longer than repeated- and single-dose aprepitant, suggesting greater potential for prolonged prevention of nausea and vomiting in ADC-treated patients. Prospective clinical validation of these model predictions would be beneficial.

Aprepitant

Unlocking the molecular engineering of Geobacillus glycoside hydrolases as a source of industrial biocatalysts.

This review examines Geobacillus sensu stricto as a source of thermostable glycoside hydrolases (GH) for biomass conversion, food processing, and enzyme engineering. Recent peer-reviewed literature was assessed with emphasis on taxonomy, genome-based Carbohydrate-Active Enzymes (CAZyme) prediction, biochemical validation, structural data, and engineering case studies. Taxonomic boundaries were interpreted using current Anoxybacillaceae frameworks, with Parageobacillus treated as a related comparator rather than as Geobacillus. The strongest evidence supports GH13 alpha-amylases, xylan-active systems, beta-xylosidases, and selected accessory enzymes. Recent studies also show that genome mining must be coupled with enzymatic assays and product profiling because CAZyme annotation alone does not prove industrial function. Molecular engineering has improved relevant traits, including the longer thermal half-life of engineered G. stearothermophilus alpha-amylase variants, the increased catalytic efficiency of oligo-alpha-1,6-glucosidase variants, and improved AmyS expression in Bacillus subtilis. Geobacillus glycoside hydrolases are best interpreted as process-specific, engineerable biocatalytic templates. Their translation requires reliable taxonomy, functional validation, structural interpretation, scalable expression and testing on realistic substrates. This synthesis also recognises current limitations: many predicted CAZymes still lack biochemical validation, complete cellulolytic systems remain less mature than xylan- and starch-active systems, and scale-up data remain scarce.

Geobacillus

PRDX1 facilitates USP7-dependent stabilization of SCD1 and promotes bladder cancer progression.

Bladder cancer is characterized by redox adaptation and metabolic plasticity, but the mechanisms linking these processes remain incompletely understood. Integrating bulk, single-cell, and spatial transcriptomic analyses, we identified PRDX1 as a malignant epithelial cell-associated factor linked to adverse outcome. Genetic gain- and loss-of-function studies showed that PRDX1 promoted proliferation, motility, and xenograft growth while limiting reactive oxygen species accumulation and mitochondrial apoptosis. Proteomic and biochemical analyses identified an association between PRDX1 and SCD1. PRDX1 prolonged the SCD1 protein half-life without detectably altering SCD1 transcript abundance and increased USP7-SCD1 co-precipitation. USP7 removed K48-linked polyubiquitin chains from SCD1 and prevented its proteasomal degradation, whereas catalytically inactive USP7 failed to deubiquitinate SCD1. Deletion of PRDX1 residues 157-199 weakened its association with SCD1 and reduced USP7-SCD1 co-precipitation. Depletion of SCD1 or USP7 suppressed PRDX1-dependent growth in vitro and in xenografts. These findings support a model in which PRDX1 facilitates USP7-dependent stabilization of SCD1 and promotes bladder cancer progression.

Bladder cancer

A Phase I Study Assessing the Safety, Tolerability, and Pharmacokinetics of Yinfenidone: A Novel, Potent Drug for Idiopathic Pulmonary Fibrosis Treatment in Healthy Chinese Subjects.

PURPOSE: Idiopathic pulmonary fibrosis (IPF) is a fatal interstitial lung disease with a median survival of only 2-3 years after diagnosis. Yinfenidone (HEC585) possesses the potential to inhibit the proliferation of pulmonary fibroblasts, making it a promising candidate for the treatment of IPF. This study assessed the safety, tolerability, pharmacokinetics, and metabolic profile of Yinfenidone hydrochloride capsule in healthy Chinese subjects. METHODS: This single-center, randomized, double-blind, placebo-controlled, single ascending-dose trial included seven dose groups(20, 50, 100, 200, 400, 600, and 800 mg). Each group enrolled8 healthy subjects: 6 received Yinfenidone hydrochloride capsules and 2 received matching placebo under fasting conditions. Serial pharmacokinetic (PK) blood samples were collected pre-dose and post-dose, liquid chromatography-tandem mass spectrometry was used to analyze the plasma concentrations of Yinfenidone. Additionally, metabolic biotransformation of Yinfenidone in plasma were conducted in the 100 mg dose group. Safety and tolerability endpoints were monitored via physical examinations, vital signs measurements, clinical laboratory tests, 12-lead electrocardiography (ECG), and adverse events (AEs) documentation throughout the trial. FINDINGS: Yinfenidone was rapidly absorbed, with a median maximum plasma concentration (Tmax) of 1.8-3.0 hours, and had a mean half-life (t1/2) ranging from 31.9 to 62.0 hours. Within the 20-100 mg dose range, systemic drug exposure generally increased with ascending dose, above 100 mg, exposure increased less than proportionally to dose. Metabolite profiling in the 100 mg group revealed that the parentcompound predominated in plasma, with metabolic pathways including mono-oxygenation and N-dealkylation. All reported AEswere mild, classified as Common Terminology Criteria for Adverse Events (CTCAE) version 4.03 grade 1. No serious AEs observed; no subject discontinued the trial due to AEs. Single oral doses of 20-800 mg Yinfenidone hydrochloride capsules administered under fasting conditions demonstrated favorable safety and tolerability profiles in healthy Chinese subjects. IMPLICATIONS: Yinfenidone exhibited rapid absorption (median Tmax, 1.8-3.0 hours) and a long terminal t1/2 ranging from 31.9 to 62.0 hours in this single ascending-dose study, indicating that Yinfenidone can be taken once a day in subsequent clinical studies. Yinfenidone mainly exists in human plasma as the original drug and is metabolized through a variety of metabolic pathways. The AEs observed with Yinfenidone in this study, such as diarrhea, nausea, and dizziness, were similar to those reported with pirfenidone. Overall, Yinfenidone demonstrated a favorable safety and tolerability profile in this cohort of healthy subjects.

Adult

A phase I clinical study of the safety, tolerability, pharmacokinetics and pharmacodynamics of SHR-2106, an anti-CD40 antibody, following single intravenous or subcutaneous administration in healthy participants.

BACKGROUND: SHR-2106 is a humanized IgG1 monoclonal antibody that blocks CD40-CD40L interactions and has demonstrated immunosuppressive activity and graft-prolonging effects in preclinical studies. This first-in-human Phase I study evaluated the safety, pharmacokinetics, pharmacodynamics, and immunogenicity of single intravenous or subcutaneous doses of SHR-2106 in healthy adults. METHODS: This randomized, double-blind, placebo-controlled Phase I study enrolled healthy participants. Fifty-one participants were enrolled in seven cohorts and received five intravenous doses (50-1200&#x202f;mg) or two subcutaneous doses (300 and 600&#x202f;mg). Safety, serum pharmacokinetics, CD40 occupancy on B cells, and anti-drug antibodies were assessed using standard clinical and bioanalytical methods. RESULTS: SHR-2106 demonstrated a favorable safety and tolerability profile, and most treatment-emergent adverse events were mild to moderate laboratory abnormalities with incidence rates comparable to placebo. SHR-2106 exhibited nonlinear pharmacokinetics consistent with target-mediated drug disposition, with a dose-dependent increase in geometric mean terminal half-life following intravenous administration (1.83-10.7 days). Absolute bioavailability after subcutaneous administration was approximately 60%. CD40 occupancy exceeded 80% within 24&#x202f;h at all doses, with saturation duration increasing from 7 to 70 days across the intravenous dose range and remaining comparable between routes at matched doses. Anti-drug antibody incidence decreased with increasing intravenous dose and did not significantly affect pharmacokinetics or pharmacodynamics. CONCLUSION: SHR-2106 was well tolerated and achieved rapid and sustained CD40 engagement, supporting dose and route selection for Phase II studies.

Humans

Structure-guided discovery of non-catechol dopamine D1 receptor ligands with biased agonism and antagonism.

The catechol L-DOPA, a cornerstone of Parkinson's disease (PD) treatment, has two major drawbacks: poor pharmacokinetics and, more significantly, debilitating dyskinesias from chronic dopamine D1 receptor (D1R) activation. Preclinical rodent studies suggest that D1R antagonism or &#x3b2;-arrestin-biased agonism can alleviate these motor complications, highlighting the need for next-generation non-catechol ligands. Through virtual screening, we identified eight novel chemotypes as D1R ligands, including two G protein-biased agonists, two &#x3b2;-arrestin-biased agonists and four antagonists. Structure-activity relationship (SAR) optimization led to the development of A82R, a non-catechol D1R antagonist (Ki 733 nM) with high D1 family over D2 family selectivity. Additionally, we present A69, a novel non-catechol &#x3b2;-arrestin-biased partial agonist for D1R (Ki 86.9 nM, stronger than representative D1R commercial drugs) with a sustained half-life of 1 h in the mouse brain. We show that the observed selectivity patterns are consistent with structural and information-theoretic limits on dopamine's ability to encode receptor subtype identity. Within these bounds, the non-catechol ligand chemotypes represent promising leads for developing therapies that modulate D1R signaling and reduce L-DOPA-induced dyskinesia in PD.

Receptors, Dopamine D1

A validated sensitive LC-MS/MS method and its application in elucidating the unique ocular pharmacokinetic profile of 0.01% atropine underpinning its clinical utility for myopia.

A sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated to quantify atropine in ten rabbit ocular tissues enabling systematic characterization of the ocular pharmacokinetic profile of 0.01% atropine sulfate eye drops after a single topical administration. The method demonstrated excellent linearity (coefficient of determination, R2&#xa0;&#x2265;&#xa0;0.9908) across all matrices, with lower limits of quantification (LLOQ) of 0.05&#xa0;ng/mL for most tissues and 0.10&#xa0;ng/mL for retina and lens; intra- and inter-day accuracy, precision, matrix effects, extraction recoveries, and stability all met the acceptance criteria. Following a single bilateral topical dose (50&#xa0;&#x3bc;L/eye) in New Zealand White rabbits, atropine distributed rapidly into all 12 ocular compartments (the sclera further divided into three anatomical regions) with marked heterogeneity-the highest exposures were found in conjunctiva and cornea, a distinct anterior-to-posterior concentration gradient was observed in the sclera, sustained retention was noted in the retina (mean residence time from zero to the last measurable time point, MRT0-t 3.30&#xa0;h), while aqueous and vitreous humor eliminated rapidly (elimination half-life, t&#x2081;/&#x2082;&#xa0;<&#xa0;0.7&#xa0;h), and all tissues except aqueous humor followed a two-compartment model. This validated method and the comprehensive pharmacokinetic data reveal that topically applied 0.01% atropine achieves sustained exposure in key myopia-regulating tissues (retina, choroid, posterior sclera) with low exposure in side-effect target tissues (iris, ciliary body, lens).

Animals

Characterization of a series of patients with GNE-related thrombocytopenia: insights into pathogenesis, diagnosis, and treatment.

BACKGROUND: GNE-related thrombocytopenia (GNE-RT) is a very rare disorder caused by biallelic variants in GNE, which encodes a key enzyme in sialic acid biosynthesis. Patients usually present with severe thrombocytopenia and excessive bleeding. Knowledge of this condition remains limited. There are no recognized diagnostic tests for the diagnosis of GNE-RT. A previous study showed reduced platelet half-life as a mechanism of thrombocytopenia; however, it remains unclear whether the sialylation defect also impairs platelet biogenesis. OBJECTIVES: To gain insights into the clinical aspects and platelet biogenesis of GNE-RT. METHODS: We investigated 4 new GNE-RT patients (3 families). A recently standardized flow cytometry assay was used to characterize platelet sialylation. Patients' megakaryocytes were cultured to study megakaryopoiesis and proplatelet formation. A validated 3-dimensional bone marrow model was used to investigate platelet production. RESULTS: We characterized 3 novel GNE variants and demonstrated the pathogenicity of 2 variants of uncertain significance. In all individuals, platelet flow cytometry showed increased RCA-1 and ECL lectin binding and decreased MAL-II binding. Sialylation of serum transferrin showed no clear alterations. Despite the sialylation defect, patients' megakaryocytes showed preserved differentiation, maturation, and proplatelet formation. Ex vivo, megakaryocytes produced a normal number of normal-sized platelets. Two patients received eltrombopag and achieved a durable clinical response (38- and 72-month follow-up). CONCLUSION: The profound megakaryocyte sialylation defect induced by GNE variants does not affect platelet biogenesis. Platelet flow cytometry assessing RCA-1 and MAL-II binding is a reliable, simple assay for diagnosing GNE-RT. Based on a literature review, 55% of GNE-RT patients respond to thrombopoietin mimetics.

GNE gene

Parasite clearance in patients with Plasmodium vivax monoinfection treated with artesunate in Cambodia: an observational secondary analysis of trial data.

BACKGROUND: Artemisinin-based combination therapies are the frontline drugs for the treatment of malaria infections, but, for Plasmodium falciparum, the efficacy of artemisinin is threatened by the spread of resistance. Plasmodium vivax is the second most common cause of human malaria, but there is little information on its susceptibility to artemisinin due to the lack of an in-vitro culture system. This study aims to characterise the response of P vivax to artesunate using clinical, genomic, and transcriptomic data from infected individuals in Cambodia. METHODS: We analysed 161 P vivax infections from 87 patients (six female and 81 male; median age 20 years [IQR 17-26]) enrolled between Nov 10, 2021, and Nov 18, 2022, in a drug efficacy study in Cambodia and treated with 2 mg/kg/day of artesunate for 7 days. To determine clearance rates, we measured parasitaemia before, and 1 h, 2 h, 4 h, 8 h, and 16 h after the first dose of artesunate, and then at 24-h intervals during the 7 days of artesunate therapy. We also examined the parasites' genome sequences and used RNA sequencing of 31 infections to analyse changes in parasite gene expression upon treatment. FINDINGS: All infections were successfully cleared by day 3. However, 49 of the infections displayed a slow clearance after treatment, including nine (6%) infections with a parasite clearance slope half-life greater than 5 h. We observed no significant association between slow clearance and either patient or infection characteristics (including the infection's stage composition). Analyses of gene expression showed that, while fast-clearing parasites displayed significant changes in gene expression immediately upon treatment, slow-clearing parasites had a delayed gene expression response characterised notably by a downregulation of genes associated with haemoglobin endocytosis and digestion. INTERPRETATION: Some Cambodian P vivax parasites clear slowly after artesunate treatment, possibly due to a downregulation of haemoglobin metabolism that might reduce the efficiency of the artesunate. The slow clearance could allow parasites to outlast artesunate treatment and facilitate emergence of resistance to the artemisinin-combination therapy partner drug, threatening malaria elimination effort. FUNDING: US National Institutes of Health.

Adolescent

Proteome Dynamics in iPSC-Derived Human Dopaminergic Neurons.

Dopaminergic neurons participate in fundamental physiological processes and are the cell type primarily affected in Parkinson's disease. Their analysis is challenging due to the intricate nature of their function, involvement in diverse neurological processes, and heterogeneity and localization in deep brain regions. Consequently, most of the research on the protein dynamics of dopaminergic neurons has been performed in animal cells ex&#xa0;vivo. Here we use iPSC-derived human mid-brain-specific dopaminergic neurons to study general features of their proteome biology and provide datasets for protein turnover and dynamics, including a human axonal translatome. We cover the proteome to a depth of 9409 proteins and use dynamic SILAC to measure the half-life of more than 4300 proteins. We report uniform turnover rates of conserved cytosolic protein complexes such as the proteasome and map the variable rates of turnover of the respiratory chain complexes in these cells. We use differential dynamic SILAC labeling in combination with microfluidic devices to analyze local protein synthesis and transport between axons and soma. We report 105 potentially novel axonal markers and detect translocation of 269 proteins between axons and the soma in the time frame of our analysis (120&#xa0;h). Importantly, we provide evidence for local synthesis of 154 proteins in the axon and their retrograde transport to the soma, among them several proteins involved in RNA editing such as ADAR1 and the RNA helicase DHX30, involved in the assembly of mitochondrial ribosomes. Our study provides a workflow and resource for the future applications of quantitative proteomics in iPSC-derived human neurons.

Humans

Safety and Tolerability of Oral Islatravir Once Monthly as Pre-exposure Prophylaxis in Cisgender Men and Transgender Women Who Have an Elevated Likelihood of HIV-1 Exposure: Results From the IMPOWER-24 Randomized Phase 3 Study.

BACKGROUND: Islatravir once monthly (qm), a nucleoside reverse transcriptase translocation inhibitor with a long half-life, was evaluated for safety and tolerability in cisgender men and transgender women who have sex with men and are at increased likelihood of HIV-1 (HIV) exposure. METHODS: IMPOWER-24 (NCT04652700) was a double-blind, Phase 3 study. Participants were randomized 2:1 to islatravir 60 mg oral qm or emtricitabine (FTC; 200 mg) coformulated with either tenofovir disoproxil (245 mg) or tenofovir alafenamide (TAF; 25 mg) once daily (qd). After &#x223c;9 months, blinded islatravir was discontinued due to lymphocyte reductions; participants were offered open-label comparator for 20 months. RESULTS: In total, 494 participants were enrolled (328 islatravir; 166 comparator): 91.5% were cisgender men, 41.7% were White, and median age was 27 years. Mean blinded dosing duration was 4.7 months (islatravir) versus 4.3 months (comparator). Overall, 211 participants (64.3%) in the islatravir group and 128 (77.1%) in the comparator group had &#x2265;1 adverse event (AE). Most AEs were mild or moderate, with 1 AE leading to product discontinuation (islatravir; gastroesophageal reflux). Serious AEs occurred in <2%; none were related to study product. Change in total lymphocytes in the islatravir group at Month 3 was -7.4%; a trend toward recovery was observed after islatravir was stopped. Mean total lymphocytes remained within normal range. No HIV infections occurred in either group during the double-blind phase. CONCLUSIONS: Islatravir qm was generally well tolerated; decreases in total lymphocytes were observed with islatravir. Original primary efficacy objectives were not assessed due to early study stoppage.

Humans

Recent advances in Strongyloides screening, diagnostics, therapeutics, and management.

PURPOSE OF REVIEW: Strongyloidiasis affects an estimated 30-100 million people globally and can have life-threatening consequences in immunocompromised hosts, yet it remains underdiagnosed due to limited access and performance of available diagnostics. Novel assays and anthelmintics may reshape screening, diagnosis, treatment, and prevention for at-risk populations. RECENT FINDINGS: Advances in molecular diagnostics coupled with robust stool extraction methods have supplanted traditional parasitologic methods in settings where nucleic acid amplification is feasible. Transition from standard immunoglobulin G (IgG)-based immunoassays to the new IgG- and IgG4-based rapid diagnostic tests using recombinant Strongyloides stercoralis nematode immunodominant E antigen (NIE) and/or S. stercoralis immunoreactive antigen (SsIR) has facilitated serologic screening at the point of care. The World Health Organization now conditionally recommends community-wide ivermectin mass drug administration in highly endemic settings. Regarding new treatment options, moxidectin is noninferior to ivermectin with 93-94% cure rates and a longer half-life, while emodepside shows 80-90% predicted cure rates in early trials and offers a mechanistically distinct option. Understanding of immunosuppressed populations at risk for hyperinfection has expanded, prompting updated screening recommendations. SUMMARY: Serologic and molecular tools are improving screening and diagnosis, and moxidectin and emodepside may broaden treatment options, but data in severe disease and special populations remain limited. Priorities include harmonized screening algorithms and prospective studies in high-risk groups.

Humans