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Each cargo in a cell employs a unique set of motor proteins for its transport. To dissect the roles of each type of motor, we developed optogenetic inhibitors of endogenous kinesin-1, -2, -3 and dynein motors and examined their effect on the transport of early endosomes, late endosomes, and lysosomes. While kinesin-1, -3, and dynein transport vesicles at all stages of endocytosis, kinesin-2 primarily drives late endosomes and lysosomes. Transient optogenetic inhibition of kinesin-1 or dynein causes both early and late endosomes to move more processively by relieving competition with opposing motors. Kinesin-2 and -3 support long-range transport, and optogenetic inhibition reduces the distances that their cargoes move. These results suggest that the directionality of transport is controlled through regulating kinesin-1 and dynein activity. On vesicles transported by several kinesin and dynein motors, modulating the activity of a single type of motor on the cargo is sufficient to direct motility.
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Background: Short-course tuberculosis (TB) prevention regimens, including 12 weeks of isoniazid and rifapentine (3HP), are increasingly used in high TB-burden countries. Despite established safety and tolerability in efficacy trials, 3HP-related adverse events (AE) could differ in routine settings. Real-world data on AE type, frequency, and timing is crucial for health systems considering 3HP programmatic scale-up. Methods: We reviewed AEs among people living with HIV (PLHIV) participating in a pragmatic implementation trial of facilitated 3HP taken by directly observed therapy (DOT) or self-administered therapy (SAT) in Kampala, Uganda, and classified them using the Common Terminology Criteria for Adverse Events. We assessed AE timing and summarized related clinical actions including lab tests, diagnoses made, medications prescribed, and treatment interruptions. Results: Among 1655 PLHIV treated between July 2020-September 2022, 270 (16.3%) reported 451 events; main issues included general (7%), nervous system (6%), musculoskeletal (5%), gastrointestinal (5%), and dermatologic (3%) disorders. Most (61%) occurred within 6 weeks of initiating 3HP. Among those with events, 211 (78%) required further clinician evaluation, 202 (75%) required laboratory testing, 102 (38%) had medications prescribed, 40 (15%) had treatment paused, and 14 (5%) discontinued 3HP. Women, those multidimensionally impoverished, and DOT recipients were more likely to report an AE. SAT users and later enrollees were more likely to have 3HP interrupted or stopped due to an AE. Conclusions: In a routine setting, 3HP was safe with 16% of PLHIV reporting AEs and only 3% requiring temporary or permanent treatment interruption. These findings support 3HP expansion in routine HIV/AIDS care settings for TB prevention.
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Organelles and vesicular cargoes are transported by teams of kinesin and dynein motors along microtubules. We isolated endocytic organelles from cells at different stages of maturation and reconstituted their motility along microtubules in vitro. We asked how the sets of motors transporting a cargo determine its motility and response to the microtubule-associated protein tau. Here, we find that phagosomes move in both directions along microtubules, but the directional bias changes during maturation. Early phagosomes exhibit retrograde-biased transport while late phagosomes are directionally unbiased. Correspondingly, early and late phagosomes are bound by different numbers and combinations of kinesins-1, -2, -3, and dynein. Tau stabilizes microtubules and directs transport within neurons. While single-molecule studies show that tau differentially regulates the motility of kinesins and dynein in vitro, less is known about its role in modulating the trafficking of endogenous cargoes transported by their native teams of motors. Previous studies showed that tau preferentially inhibits kinesin motors, which biases late phagosome transport towards the microtubule minus-end. Here, we show that tau strongly inhibits long-range, dynein-mediated motility of early phagosomes. Tau reduces forces generated by teams of dynein motors on early phagosomes and accelerates dynein unbinding under load. Thus, cargoes differentially respond to tau, where dynein complexes on early phagosomes are more sensitive to tau inhibition than those on late phagosomes. Mathematical modeling further explains how small changes in the number of kinesins and dynein on cargoes impact the net directionality but also that cargoes with different sets of motors respond differently to tau.
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Dineínas , Cinesinas , Microtúbulos , Proteínas tau , Cinesinas/metabolismo , Cinesinas/genética , Proteínas tau/metabolismo , Proteínas tau/genética , Dineínas/metabolismo , Dineínas/genética , Animales , Microtúbulos/metabolismo , Fagosomas/metabolismo , Transporte Biológico , Ratones , Humanos , Endocitosis/fisiologíaRESUMEN
BACKGROUND: Expanding access to shorter regimens for tuberculosis (TB) prevention, such as once-weekly isoniazid and rifapentine taken for 3 months (3HP), is critical for reducing global TB burden among people living with HIV (PLHIV). Our coprimary hypotheses were that high levels of acceptance and completion of 3HP could be achieved with delivery strategies optimized to overcome well-contextualized barriers and that 3HP acceptance and completion would be highest when PLHIV were provided an informed choice between delivery strategies. METHODS AND FINDINGS: In a pragmatic, single-center, 3-arm, parallel-group randomized trial, PLHIV receiving care at a large urban HIV clinic in Kampala, Uganda, were randomly assigned (1:1:1) to receive 3HP by facilitated directly observed therapy (DOT), facilitated self-administered therapy (SAT), or informed choice between facilitated DOT and facilitated SAT using a shared decision-making aid. We assessed the primary outcome of acceptance and completion (≥11 of 12 doses of 3HP) within 16 weeks of treatment initiation using proportions with exact binomial confidence intervals (CIs). We compared proportions between arms using Fisher's exact test (two-sided α = 0.025). Trial investigators were blinded to primary and secondary outcomes by study arm. Between July 13, 2020, and July 8, 2022, 1,656 PLHIV underwent randomization, with equal numbers allocated to each study arm. One participant was erroneously enrolled a second time and was excluded in the primary intention-to-treat analysis. Among the remaining 1,655 participants, the proportion who accepted and completed 3HP exceeded the prespecified 80% target in the DOT (0.94; 97.5% CI [0.91, 0.96] p < 0.001), SAT (0.92; 97.5% CI [0.89, 0.94] p < 0.001), and Choice (0.93; 97.5% CI [0.91, 0.96] p < 0.001) arms. There was no difference in acceptance and completion between any 2 arms overall or in prespecified subgroup analyses based on sex, age, time on antiretroviral therapy, and history of prior treatment for TB or TB infection. Only 14 (0.8%) participants experienced an adverse event prompting discontinuation of 3HP. The main limitation of the study is that it was conducted in a single center. Multicenter studies are now needed to confirm the feasibility and generalizability of the facilitated 3HP delivery strategies in other settings. CONCLUSIONS: Short-course TB preventive treatment was widely accepted by PLHIV in Uganda, and very high levels of treatment completion were achieved in a programmatic setting with delivery strategies tailored to address known barriers. TRIAL REGISTRATION: ClinicalTrials.gov NCT03934931.
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Infecciones por VIH , Tuberculosis Latente , Rifampin/análogos & derivados , Tuberculosis , Humanos , Isoniazida/efectos adversos , Tuberculosis/tratamiento farmacológico , Tuberculosis/prevención & control , Antituberculosos/efectos adversos , Uganda , Tuberculosis Latente/tratamiento farmacológico , Quimioterapia Combinada , Infecciones por VIH/complicaciones , Infecciones por VIH/tratamiento farmacológicoRESUMEN
Kinesins support many diverse cellular processes, including facilitating cell division through mechanical regulation of the mitotic spindle. However, how kinesin activity is controlled to facilitate this process is not well understood. Interestingly, posttranslational modifications have been identified within the enzymatic region of all 45 mammalian kinesins, but the significance of these modifications has gone largely unexplored. Given the critical role of the enzymatic region in facilitating nucleotide and microtubule binding, it may serve as a primary site for kinesin regulation. Consistent with this idea, a phosphomimetic mutation at S357 in the neck-linker of KIF18A alters the localization of KIF18A within the spindle from kinetochore microtubules to nonkinetochore microtubules at the periphery of the spindle. Changes in localization of KIF18A-S357D are accompanied by defects in mitotic spindle positioning and the ability to promote mitotic progression. This altered localization pattern is mimicked by a shortened neck-linker mutant, suggesting that KIF18A-S357D may cause the motor to adopt a shortened neck-linker-like state that decreases KIF18A accumulation at the plus-ends of kinetochore microtubules. These findings demonstrate that posttranslational modifications in the enzymatic region of kinesins could be important for biasing their localization to particular microtubule subpopulations.
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Cinesinas , Cinetocoros , Microtúbulos , Animales , Humanos , Células HeLa , Cinesinas/metabolismo , Cinetocoros/metabolismo , Microtúbulos/metabolismo , Mitosis , Huso Acromático/metabolismoRESUMEN
Background: Tuberculosis (TB) preventive treatment (TPT) is recommended for people living with HIV (PLHIV) in high TB burden settings. While 6 months of daily isoniazid remains widely used, shorter regimens are now available. However, little is known about preferences of PLHIV for key features of TPT regimens. Methods: We conducted a discrete choice experiment among adult PLHIV engaged in care at an urban HIV clinic in Kampala, Uganda. In nine random choice tasks, participants chose between two hypothetical TPT regimens with different features (pills per dose, frequency, duration, need for adjusted antiretroviral therapy [ART] dosage and side effects). We analyzed preferences using hierarchical Bayesian estimation, latent class analysis, and willingness-to-trade simulations. Results: Of 400 PLHIV, 392 (median age 44, 72% female, 91% TPT-experienced) had high quality choice task responses. Pills per dose was the most important attribute (relative importance 32.4%, 95% confidence interval [CI] 31.6 - 33.2), followed by frequency (20.5% [95% CI 19.7 - 21.3]), duration (19.5% [95% CI 18.6 - 20.5]), and need for ART dosage adjustment (18.2% [95% CI 17.2 - 19.2]). Latent class analysis identified three preference groups: one prioritized less frequent, weekly dosing (N=222; 57%); another was averse to ART dosage adjustment (N=107; 27%); and the last prioritized short and tolerable regimens (N=63; 16%). All groups highly valued fewer pills per dose. Participants were willing to accept a regimen of 2.8 months' additional duration [95% CI: 2.4 - 3.2] to reduce pills per dose from five to one, 3.6 [95% CI 2.4 - 4.8] months for weekly rather than daily dosing, and 2.2 [95% CI 1.3 - 3.0] months to avoid ART dosage adjustment. Conclusions: To align with preferences of PLHIV, decision-makers should prioritize the development and implementation of TPT regimens with fewer pills, less frequent dosing, and no need for ART dosage adjustment, rather than focus primarily on duration of treatment.
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The etiology of Tauopathies, a diverse class of neurodegenerative diseases associated with the Microtubule Associated Protein (MAP) Tau, is usually described by a common mechanism in which Tau dysfunction results in the loss of axonal microtubule stability. Here, we reexamine and build upon the canonical disease model to encompass other Tau functions. In addition to regulating microtubule dynamics, Tau acts as a modulator of motor proteins, a signaling hub, and a scaffolding protein. This diverse array of functions is related to the dynamic nature of Tau isoform expression, post-translational modification (PTM), and conformational flexibility. Thus, there is no single mechanism that can describe Tau dysfunction. The effects of specific pathogenic mutations or aberrant PTMs need to be examined on all of the various functions of Tau in order to understand the unique etiology of each disease state.
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Enfermedades Neurodegenerativas , Tauopatías , Humanos , Enfermedades Neurodegenerativas/genética , Enfermedades Neurodegenerativas/metabolismo , Transporte Axonal , Proteínas tau/genética , Proteínas tau/metabolismo , Tauopatías/genética , Tauopatías/metabolismo , Procesamiento Proteico-Postraduccional , Microtúbulos/metabolismoRESUMEN
99DOTS is a low-cost digital adherence technology that allows people with tuberculosis (TB) to self-report treatment adherence. There are limited data on its implementation, feasibility, and acceptability from sub-Saharan Africa. We conducted a longitudinal analysis and cross-sectional surveys nested within a stepped-wedge randomized trial at 18 health facilities in Uganda between December 2018 and January 2020. The longitudinal analysis assessed implementation of key components of a 99DOTS-based intervention, including self-reporting of TB medication adherence via toll-free phone calls, automated text message reminders and support actions by health workers monitoring adherence data. Cross-sectional surveys administered to a subset of people with TB and health workers assessed 99DOTS feasibility and acceptability. Composite scores for capability, opportunity, and motivation to use 99DOTS were estimated as mean Likert scale responses. Among 462 people with pulmonary TB enrolled on 99DOTS, median adherence was 58.4% (inter-quartile range [IQR] 38.7-75.6) as confirmed by self-reporting dosing via phone calls and 99.4% (IQR 96.4-100) when also including doses confirmed by health workers. Phone call-confirmed adherence declined over the treatment period and was lower among people with HIV (median 50.6% vs. 63.7%, p<0.001). People with TB received SMS dosing reminders on 90.5% of treatment days. Health worker support actions were documented for 261/409 (63.8%) people with TB who missed >3 consecutive doses. Surveys were completed by 83 people with TB and 22 health workers. Composite scores for capability, opportunity, and motivation were high; among people with TB, composite scores did not differ by gender or HIV status. Barriers to using 99DOTS included technical issues (phone access, charging, and network connection) and concerns regarding disclosure. 99DOTS was feasible to implement and highly acceptable to people with TB and their health workers. National TB Programs should offer 99DOTS as an option for TB treatment supervision.
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Kinesins support many diverse cellular processes, including facilitating cell division through mechanical regulation of the mitotic spindle. However, how kinesin activity is controlled to facilitate this process is not well understood. Interestingly, post-translational modifications have been identified within the enzymatic region of all 45 mammalian kinesins, but the significance of these modifications has gone largely unexplored. Given the critical role of the enzymatic region in facilitating nucleotide and microtubule binding, it may serve as a primary site for kinesin regulation. Consistent with this idea, a phosphomimetic mutation at S357 in the neck-linker of KIF18A alters the localization of KIF18A within the spindle from kinetochore microtubules to peripheral microtubules. Changes in localization of KIF18A-S357D are accompanied by defects in mitotic spindle positioning and the ability to promote mitotic progression. This altered localization pattern is mimicked by a shortened neck-linker mutant, suggesting that KIF18A-S357D may cause the motor to adopt a shortened neck-linker like state that prevents KIF18A from accumulating at the plus-ends of kinetochore microtubules. These findings demonstrate that post-translational modifications in the enzymatic region of kinesins could be important for biasing their localization to particular microtubule subpopulations.
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BACKGROUND: Ensuring the completion of treatment for tuberculosis (TB) remains a key challenge in many high-burden countries. 99DOTS is a low-cost digital adherence technology that has emerged as a promising tool for monitoring and supporting TB treatment completion. OBJECTIVE: We aimed to understand the feasibility and acceptability of 99DOTS, a mobile phone-based TB treatment support method, and characterize barriers and facilitators to its implementation during a pragmatic trial in Uganda. METHODS: Between April 1 and August 31, 2021, we conducted in-depth interviews with people with TB and key informant interviews with health workers and district and regional TB officers involved in the implementation of 99DOTS at 18 health facilities in Uganda. Semistructured interview guides were informed by the capability, opportunity, motivation, and behavior (COM-B) model and explored perceptions of, and experiences with, 99DOTS, including barriers and facilitators to its use. Qualitative analysis was conducted using the framework approach. RESULTS: Interviews were conducted with 30 people with TB, 12 health workers, and 7 TB officers. All people with TB, health workers, and TB officers noted that 99DOTS supported and encouraged people with TB to take their anti-TB medication, facilitated treatment monitoring, and improved relationships between people with TB and health workers. Participants also liked that the platform was free, easy to use, and improved TB treatment outcomes. Barriers to 99DOTS implementation for some people with TB were related to limited literacy, including technology literacy; limited access to electricity to charge their mobile phone to make dosing confirmation calls; and poor network connection. Gender differences in 99DOTS uptake also emerged. Specifically, women with TB were described to be more concerned that 99DOTS use would expose them to TB stigma and to be more likely to have mobile phone-access issues than men with TB. By contrast, men with TB not only had access to mobile phones but also received substantial support from their female partners to take their anti-TB medication and make 99DOTS dosing confirmation calls. Finally, although women with TB were described to face more barriers to 99DOTS use than men with TB, the women's narratives centered on the ways the platform facilitated and improved their adherence, whereas the men's narratives did not. CONCLUSIONS: Overall, 99DOTS seems to be a feasible and acceptable strategy to support anti-TB medication adherence in Uganda. However, access to mobile phones, inability to charge mobile phones, and concerns about stigma should be considered and addressed as part of programmatic implementation to maximize uptake among all people with TB, particularly women and those with fewer financial resources.
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Telemedicina , Tuberculosis , Masculino , Humanos , Femenino , Uganda , Tuberculosis/tratamiento farmacológico , Investigación Cualitativa , Telemedicina/métodos , Tecnología DigitalRESUMEN
Recent evidence suggests that imagined auditory and visual sensory stimuli can be integrated with real sensory information from a different sensory modality to change the perception of external events via cross-modal multisensory integration mechanisms. Here, we explored whether imagined voluntary movements can integrate visual and proprioceptive cues to change how we perceive our own limbs in space. Participants viewed a robotic hand wearing a glove repetitively moving its right index finger up and down at a frequency of 1 Hz, while they imagined executing the corresponding movements synchronously or asynchronously (kinesthetic-motor imagery); electromyography (EMG) from the participants' right index flexor muscle confirmed that the participants kept their hand relaxed while imagining the movements. The questionnaire results revealed that the synchronously imagined movements elicited illusory ownership and a sense of agency over the moving robotic hand-the moving rubber hand illusion-compared with asynchronously imagined movements; individuals who affirmed experiencing the illusion with real synchronous movement also did so with synchronous imagined movements. The results from a proprioceptive drift task further demonstrated a shift in the perceived location of the participants' real hand toward the robotic hand in the synchronous versus the asynchronous motor imagery condition. These results suggest that kinesthetic motor imagery can be used to replace veridical congruent somatosensory feedback from a moving finger in the moving rubber hand illusion to trigger illusory body ownership and agency, but only if the temporal congruence rule of the illusion is obeyed. This observation extends previous studies on the integration of mental imagery and sensory perception to the case of multisensory bodily awareness, which has potentially important implications for research into embodiment of brain-computer interface controlled robotic prostheses and computer-generated limbs in virtual reality.
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Ilusiones , Percepción del Tacto , Humanos , Ilusiones/fisiología , Percepción del Tacto/fisiología , Retroalimentación Sensorial , Mano/fisiología , Dedos , Propiocepción/fisiología , Percepción Visual/fisiología , Imagen CorporalRESUMEN
INTRODUCTION: High levels of treatment adherence are critical for achieving optimal treatment outcomes among patients with tuberculosis (TB), especially for drug-resistant TB (DR TB). Current tools for identifying high-risk non-adherence are insufficient. Here, we apply trajectory analysis to characterize adherence behavior early in DR TB treatment and assess whether these patterns predict treatment outcomes. METHODS: We conducted a retrospective analysis of Philippines DR TB patients treated between 2013 and 2016. To identify unique patterns of adherence, we performed group-based trajectory modelling on adherence to the first 12 weeks of treatment. We estimated the association of adherence trajectory group with six-month and final treatment outcomes using univariable and multivariable logistic regression. We also estimated and compared the predictive accuracy of adherence trajectory group and a binary adherence threshold for treatment outcomes. RESULTS: Of 596 patients, 302 (50.7%) had multidrug resistant TB, 11 (1.8%) extremely drug-resistant (XDR) TB, and 283 (47.5%) pre-XDR TB. We identified three distinct adherence trajectories during the first 12 weeks of treatment: a high adherence group (n = 483), a moderate adherence group (n = 93) and a low adherence group (n = 20). Similar patterns were identified at 4 and 8 weeks. Being in the 12-week moderate or low adherence group was associated with unfavorable six-month (adjusted OR [aOR] 3.42, 95% CI 1.90-6.12) and final (aOR 2.71, 95% 1.73-4.30) treatment outcomes. Adherence trajectory group performed similarly to a binary threshold classification for the prediction of final treatment outcomes (65.9% vs. 65.4% correctly classified), but was more accurate for prediction of six-month treatment outcomes (79.4% vs. 60.0% correctly classified). CONCLUSIONS: Adherence patterns are strongly predictive of DR TB treatment outcomes. Trajectory-based analyses represent an exciting avenue of research into TB patient adherence behavior seeking to inform interventions which rapidly identify and support patients with high-risk adherence patterns.
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Tuberculosis Resistente a Múltiples Medicamentos , Tuberculosis , Humanos , Antituberculosos/uso terapéutico , Estudios Retrospectivos , Filipinas/epidemiología , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Tuberculosis Resistente a Múltiples Medicamentos/epidemiología , Tuberculosis/tratamiento farmacológicoRESUMEN
Regulation of the neuronal microtubule cytoskeleton is achieved through the coordination of microtubule-associated proteins (MAPs). MAP-Tau, the most abundant MAP in the axon, functions to modulate motor motility, participate in signaling cascades, as well as directly mediate microtubule dynamics. Tau misregulation is associated with a class of neurodegenerative diseases, known as tauopathies, including progressive supranuclear palsy, Pick's disease, and Alzheimer's disease. Many disease-associated mutations in Tau are found in the C-terminal microtubule-binding domain. These mutations decrease microtubule-binding affinity and are proposed to reduce microtubule stability, leading to disease. N-terminal disease-associated mutations also exist, but the mechanistic details of their downstream effects are not as clear. Here, we investigate the effect of the progressive supranuclear palsy-associated N-terminal R5L mutation on Tau-mediated microtubule dynamics using an in vitro reconstituted system. We show that the R5L mutation does not alter Tau interactions with tubulin by fluorescence correlation spectroscopy. Using total internal reflection fluorescence microscopy, we determined that the R5L mutation has no effect on microtubule growth rate, catastrophe frequency, or rescue frequency. Rather, the R5L mutation increases microtubule shrinkage rate. We determine this is due to disruption of Tau patches, larger order Tau complexes known to form on the GDP-microtubule lattice. Altogether, these results provide insight into the role of Tau patches in mediating microtubule dynamics and suggesting a novel mechanism by which mutations in the N-terminal projection domain reduce microtubule stability.
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Parálisis Supranuclear Progresiva , Tauopatías , Proteínas tau , Humanos , Microtúbulos/metabolismo , Microtúbulos/patología , Mutación , Parálisis Supranuclear Progresiva/genética , Parálisis Supranuclear Progresiva/metabolismo , Proteínas tau/genética , Proteínas tau/metabolismo , Tauopatías/genética , Tauopatías/metabolismoRESUMEN
Microtubule-associated proteins (MAPs) modulate the motility of kinesin and dynein along microtubules to control the transport of vesicles and organelles. The neuronal MAP tau inhibits kinesin-dependent transport. Phosphorylation of tau at Tyr-18 by fyn kinase results in weakened inhibition of kinesin-1. We examined the motility of early endosomes and lysosomes in cells expressing wild-type (WT) tau and phosphomimetic Y18E tau. We quantified the effects on motility as a function of the tau expression level. Lysosome motility is strongly inhibited by tau. Y18E tau preferentially inhibits lysosomes in the cell periphery, while centrally located lysosomes are less affected. Early endosomes are more sensitive to tau than lysosomes and are inhibited by both WT and Y18E tau. Our results show that different cargoes have disparate responses to tau, likely governed by the types of kinesin motors driving their transport. In support of this model, kinesin-1 and -3 are strongly inhibited by tau while kinesin-2 and dynein are less affected. In contrast to kinesin-1, we find that kinesin-3 is strongly inhibited by phosphorylated tau.
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Dineínas , Cinesinas , Dineínas/metabolismo , Microtúbulos/metabolismo , Proteínas Asociadas a Microtúbulos/metabolismo , Lisosomas/metabolismo , Endosomas/metabolismo , Proteínas tau/metabolismo , Transporte BiológicoRESUMEN
The microtubule-associated protein (MAP) Tau is an intrinsically disordered protein (IDP) primarily expressed in axons, where it functions to regulate microtubule dynamics, modulate motor protein motility, and participate in signaling cascades. Tau misregulation and point mutations are linked to neurodegenerative diseases, including progressive supranuclear palsy (PSP), Pick's disease, and Alzheimer's disease. Many disease-associated mutations in Tau occur in the C-terminal microtubule-binding domain of the protein. Effects of C-terminal mutations in Tau have led to the widely accepted disease-state theory that missense mutations in Tau reduce microtubule-binding affinity or increase Tau propensity to aggregate. Here, we investigate the effect of an N-terminal arginine to leucine mutation at position 5 in Tau (R5L), associated with PSP, on Tau-microtubule interactions using an in vitro reconstituted system. Contrary to the canonical disease-state theory, we determine that the R5L mutation does not reduce Tau affinity for the microtubule using total internal reflection fluorescence microscopy. Rather, the R5L mutation decreases the ability of Tau to form larger-order complexes, or Tau patches, at high concentrations of Tau. Using NMR, we show that the R5L mutation results in a local structural change that reduces interactions of the projection domain in the presence of microtubules. Altogether, these results challenge both the current paradigm of how mutations in Tau lead to disease and the role of the projection domain in modulating Tau behavior on the microtubule surface.
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Microtúbulos/metabolismo , Proteínas tau/metabolismo , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Humanos , Microtúbulos/química , Microtúbulos/genética , Mutación , Proteínas tau/química , Proteínas tau/genéticaRESUMEN
BACKGROUND: Scaling up shorter regimens for tuberculosis (TB) prevention such as once weekly isoniazid-rifapentine (3HP) taken for 3 months is a key priority for achieving targets set forth in the World Health Organization's (WHO) END TB Strategy. However, there are few data on 3HP patient acceptance and completion in the context of routine HIV care in sub-Saharan Africa. METHODS AND FINDINGS: The 3HP Options Trial is a pragmatic, parallel type 3 effectiveness-implementation randomized trial comparing 3 optimized strategies for delivering 3HP-facilitated directly observed therapy (DOT), facilitated self-administered therapy (SAT), or informed choice between DOT and SAT using a shared decision-making aid-to people receiving care at a large urban HIV clinic in Kampala, Uganda. Participants and healthcare providers were not blinded to arm assignment due to the nature of the 3HP delivery strategies. We conducted an interim analysis of participants who were enrolled and exited the 3HP treatment period between July 13, 2020 and April 30, 2021. The primary outcome, which was aggregated across trial arms for this interim analysis, was the proportion who accepted and completed 3HP (≥11 of 12 doses within 16 weeks of randomization). We used Bayesian inference analysis to estimate the posterior probability that this proportion would exceed 80% under at least 1 of the 3HP delivery strategies, a coprimary hypothesis of the trial. Through April 2021, 684 participants have been enrolled, and 479 (70%) have exited the treatment period. Of these 479 participants, 309 (65%) were women, mean age was 41.9 years (standard deviation (SD): 9.2), and mean time on antiretroviral therapy (ART) was 7.8 years (SD: 4.3). In total, 445 of them (92.9%, 95% confidence interval (CI): [90.2 to 94.9]) accepted and completed 3HP treatment. There were no differences in treatment acceptance and completion by sex, age, or time on ART. Treatment was discontinued due to a documented adverse event (AE) in 8 (1.7%) patients. The probability that treatment acceptance and completion exceeds 80% under at least 1 of the three 3HP delivery strategies was greater than 99%. The main limitations are that the trial was conducted at a single site, and the interim analysis focused on aggregate outcome data to maintain blinding of investigators to arm-specific outcomes. CONCLUSIONS: 3HP was widely accepted by people living with HIV (PLHIV) in Uganda, and very high levels of treatment completion were achieved in a programmatic setting. These findings show that 3HP can enable effective scale-up of tuberculosis preventive therapy (TPT) in high-burden countries, particularly when delivery strategies are tailored to target known barriers to treatment completion. TRIAL REGISTRATION: ClinicalTrials.gov NCT03934931.
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Antituberculosos/uso terapéutico , Terapia por Observación Directa , Isoniazida/uso terapéutico , Rifampin/análogos & derivados , Tuberculosis/prevención & control , Adulto , Terapia por Observación Directa/clasificación , Quimioterapia Combinada , Femenino , Infecciones por VIH/etiología , Humanos , Masculino , Persona de Mediana Edad , Rifampin/uso terapéutico , UgandaRESUMEN
BACKGROUND: A 12-dose, once-weekly regimen of isoniazid and rifapentine (3HP) is effective in preventing tuberculosis (TB) among people living with HIV (PLHIV). We sought to identify potential barriers to and facilitators of acceptance and completion of 3HP treatment from the perspective of people living with HIV (PLHIV) and health workers in a routine HIV care setting in Kampala, Uganda. METHODS: We conducted semi-structured interviews with 25 PLHIV and 10 health workers at an HIV/AIDS clinic in Kampala, Uganda. For both groups, we explored their understanding and interpretations of TB and TB preventive therapy (TPT), and perceptions about social and contextual factors that might influence the willingness of PLHIV to initiate and complete 3HP. We analyzed the data using an inductive thematic approach and aligned the emergent themes to the Behavior Change Wheel framework to identify sources of behavior and targeted behavior change interventions. RESULTS: Facilitators of acceptance and completion of 3HP treatment among PLHIV were fear of contracting TB, awareness of being at risk of getting TB, willingness to take TPT, trust in health workers, and the perceived benefits of directly observed therapy (DOT) and self-administered therapy (SAT) 3HP delivery strategies. Barriers included inadequate understanding of TPT, fear of potential side effects, concerns about the effectiveness of 3HP, and the perceived challenges of DOT or SAT. Among health workers, perceived facilitators included knowledge that TB is a common cause of mortality for PLHIV, fear of getting TB, and trust in the health workers by PLHIV, the advantages of once-weekly 3HP dosing, and the benefits of DOT and SAT 3HP delivery strategies. Health worker-reported barriers for PLHIV included inadequate understanding of TB and benefits of TPT, TB-associated stigma, potential side effects pill burden, and challenges of DOT and SAT 3HP delivery strategies. Lack of experience in the use of digital technology to monitor patient care was identified as a health worker-specific barrier. Identified intervention functions to address the facilitators or barriers included education, persuasion, environmental restructuring, enablement, and training. CONCLUSIONS: Using a formative qualitative and comprehensive theoretical approach, we identified key barriers, facilitators, and appropriate interventions, including patient education, enhancing trust, and patient-centered treatment support that could be used to optimize the delivery of 3HP to PLHIV in our setting. These interventions are likely generalizable to other clinical interventions in similar populations in sub-Saharan Africa and other TB high-burden settings.
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BACKGROUND: Adherence to and completion of tuberculosis (TB) treatment remain problematic in many high-burden countries. 99DOTS is a low-cost digital adherence technology that could increase TB treatment completion. METHODS AND FINDINGS: We conducted a pragmatic stepped-wedge cluster-randomized trial including all adults treated for drug-susceptible pulmonary TB at 18 health facilities across Uganda over 8 months (1 December 2018-31 July 2019). Facilities were randomized to switch from routine (control period) to 99DOTS-based (intervention period) TB treatment supervision in consecutive months. Patients were allocated to the control or intervention period based on which facility they attended and their treatment start date. Health facility staff and patients were not blinded to the intervention. The primary outcome was TB treatment completion. Due to the pragmatic nature of the trial, the primary analysis was done according to intention-to-treat (ITT) and per protocol (PP) principles. This trial is registered with the Pan African Clinical Trials Registry (PACTR201808609844917). Of 1,913 eligible patients at the 18 health facilities (1,022 and 891 during the control and intervention periods, respectively), 38.0% were women, mean (SD) age was 39.4 (14.4) years, 46.8% were HIV-infected, and most (91.4%) had newly diagnosed TB. In total, 463 (52.0%) patients were enrolled on 99DOTS during the intervention period. In the ITT analysis, the odds of treatment success were similar in the intervention and control periods (adjusted odds ratio [aOR] 1.04, 95% CI 0.68-1.58, p = 0.87). The odds of treatment success did not increase in the intervention period for either men (aOR 1.24, 95% CI 0.73-2.10) or women (aOR 0.67, 95% CI 0.35-1.29), or for either patients with HIV infection (aOR 1.51, 95% CI 0.81-2.85) or without HIV infection (aOR 0.78, 95% CI 0.46-1.32). In the PP analysis, the 99DOTS-based intervention increased the odds of treatment success (aOR 2.89, 95% CI 1.57-5.33, p = 0.001). The odds of completing the intensive phase of treatment and the odds of not being lost to follow-up were similarly improved in PP but not ITT analyses. Study limitations include the likelihood of selection bias in the PP analysis, inability to verify medication dosing in either arm, and incomplete implementation of some components of the intervention. CONCLUSIONS: 99DOTS-based treatment supervision did not improve treatment outcomes in the overall study population. However, similar treatment outcomes were achieved during the control and intervention periods, and those patients enrolled on 99DOTS achieved high treatment completion. 99DOTS-based treatment supervision could be a viable alternative to directly observed therapy for a substantial proportion of patients with TB. TRIAL REGISTRATION: Pan-African Clinical Trials Registry (PACTR201808609844917).
Asunto(s)
Antituberculosos/uso terapéutico , Cumplimiento de la Medicación/estadística & datos numéricos , Tecnología/estadística & datos numéricos , Tuberculosis Pulmonar/tratamiento farmacológico , Adulto , Análisis por Conglomerados , Femenino , Humanos , Masculino , Persona de Mediana Edad , Uganda , Adulto JovenRESUMEN
BACKGROUND: Digital adherence technologies have been widely promoted as a means to improve tuberculosis medication adherence. However, uptake of these technologies has been suboptimal by both patients and health workers. Not surprisingly, studies have not demonstrated significant improvement in treatment outcomes. OBJECTIVE: This study aimed to optimize a well-known digital adherence technology, 99DOTS, for end user needs in Uganda. We describe the findings of the ideation phase of the human-centered design methodology to adapt 99DOTS according to a set of design principles identified in the previous inspiration phase. METHODS: 99DOTS is a low-cost digital adherence technology wherein tuberculosis medication blister packs are encased within an envelope that reveals toll-free numbers that patients can call to report dosing. We identified 2 key areas for design and testing: (1) the envelope, including the form factor, content, and depiction of the order of pill taking; and (2) the patient call-in experience. We conducted 5 brainstorming sessions with all relevant stakeholders to generate a suite of potential prototype concepts. Senior investigators identified concepts to further develop based on feasibility and consistency with the predetermined design principles. Prototypes were revised with feedback from the entire team. The envelope and call-in experience prototypes were tested and iteratively revised through focus groups with health workers (n=52) and interviews with patients (n=7). We collected and analyzed qualitative feedback to inform each subsequent iteration. RESULTS: The 5 brainstorming sessions produced 127 unique ideas that we clustered into 6 themes: rewards, customization, education, logistics, wording and imagery, and treatment countdown. We developed 16 envelope prototypes, 12 icons, and 28 audio messages for prototype testing. In the final design, we altered the pill packaging envelope by adding a front flap to conceal the pills and reduce potential stigma associated with tuberculosis. The flap was adorned with either a blank calendar or map of Uganda. The inside cover contained a personalized message from a local health worker including contact information, pictorial pill-taking instructions, and a choice of stickers to tailor education to the patient and phase of treatment. Pill-taking order was indicated with colors, chevron arrows, and small mobile phone icons. Last, the call-in experience when patients report dosing was changed to a rotating series of audio messages centered on the themes of prevention, encouragement, and reassurance that tuberculosis is curable. CONCLUSIONS: We demonstrated the use of human-centered design as a promising tool to drive the adaptation of digital adherence technologies to better address the needs and motivations of end users. The next phase of research, known as the implementation phase in the human-centered design methodology, will investigate whether the adapted 99DOTS platform results in higher levels of engagement from patients and health workers, and ultimately improves tuberculosis treatment outcomes.
RESUMEN
BACKGROUND: Variation in healthcare delivery is increasingly recognized as an important metric of healthcare quality. Directly observed therapy (DOT) has been the standard of care for tuberculosis (TB) treatment supervision for decades based on World Health Organization (WHO) guidelines. However, variation in implementation of DOT and associated TB treatment supervision practices remains poorly defined. METHODS: We collected individual patient data from TB treatment registers at 18â¯TB treatment units in Uganda including District Health Centers, District Hospitals, and Regional Referral Hospitals. We also administered a survey and did observations of TB treatment supervision practices by health workers at each site. We describe variation in TB treatment outcomes and TB treatment supervision practices. RESULTS: Of 2767 patients treated for TB across the 18 clinical sites between January 1 and December 31, 2017, 1740 (62.9%) were men, most were of working age (median 35â¯years, interquartile range [IQR] 27 - 46), 2546 (92.0%) had a new TB diagnosis, and nearly half (45.9%, nâ¯=â¯1283) were HIV positive. The pooled treatment success proportion was 69.4% (95% confidence interval [CI] 67.8 - 71.1) but there was substantial variation across sites (range 42.6 - 87.6%, I-squared 92.7%, pâ¯<â¯0.001). The survey and observation of TB treatment practices revealed that the majority of sites practice community-based DOT (66.7%, nâ¯=â¯12) and request a family member, who receives no additional training or supervision, to serve as a treatment supporter (77.8%, nâ¯=â¯14). At TB medication refill visits, all sites screen for side effects and most assess adherence via self-report (83.3%, nâ¯=â¯15). Only 7 (38.9%) sites followed-up patients who missed appointments using either phone calls (22.2%, nâ¯=â¯4/7) or community health workers (16.7%, nâ¯=â¯3/7). All 18 sites counseled patients at treatment initiation, but none provided additional counseling at refill visits other than addressing poor adherence or missed appointments. CONCLUSION: There was substantial variation in implementation of DOT, including observation and documentation of daily dosing, training and supervision of treatment supporters, and follow-up for missed clinic visits. Identifying best practices and reducing uncontrolled variation in the delivery of TB treatment is critical to improving treatment outcomes.