Your browser doesn't support javascript.
loading
Montrer: 20 | 50 | 100
Résultats 1 - 20 de 20.573
Filtrer
1.
J. optom. (Internet) ; 17(3): [100514], jul.-sept2024. tab
Article de Anglais | IBECS | ID: ibc-231876

RÉSUMÉ

Purpose: To analyze binocular vision of individuals aged 18 to 35 years diagnosed with keratoconus, utilizing spectacles and rigid gas-permeable (RGP) contact lenses. Research was led by the Universidad Autónoma de Aguascalientes, México and Fundación Universitaria del Área Andina Pereira, Colombia. Methods: A single center, prospective non-randomized, comparative, interventional, open-label study, in which the differences in binocular vision performance with both spectacles and RGP contact lenses was carried out from December 2018 to December 2019. Sampling was performed according to consecutive cases with keratoconus that met the inclusion criteria until the proposed sample size was reached. Results: Rigid gas-permeable (RGP) contact lenses notably enhanced distance and near visual acuity in keratoconus patients compared to spectacles. Visual alignment analysis shows exophoria at both distances and is slightly higher with RGP contact lenses. The difference was statistically significant (p<0.05), with 82.5 % presenting compensated phoria with spectacles and pnly 42.50% with RGP contact lenses. Stereoscopic vision improved while wearing RGP contact lenses (42.59 %), although accommodation and accommodative flexibility remained within normal ranges. Conclusions: Patients with keratoconus fitted with RGP contact lenses have improved binocular vision skills such as visual acuity, stereopsis, and accommodative flexibility. However, even when the vergence and motor system is decompensated with respect to normal ranges, the range between break and recovery points for both fusional reserves and the near point of convergence (NPC) improves with the use of RGP contact lenses, giving indications of an adaptive condition of the motor system from the medium to the long term.(AU)


Sujet(s)
Humains , Mâle , Femelle , Adolescent , Jeune adulte , Kératocône , Lunettes correctrices , Lentilles de contact , Vision binoculaire , Tests de vision , Colombie , Mexique , Ophtalmologie , Études prospectives
2.
Front Cell Dev Biol ; 12: 1279723, 2024.
Article de Anglais | MEDLINE | ID: mdl-39086660

RÉSUMÉ

Cell-cell contact formation of polarized epithelial cells is a multi-step process that involves the co-ordinated activities of Rho family small GTPases. Consistent with the central role of Rho GTPases, a number of Rho guanine nucleotide exchange factors (GEFs) and Rho GTPase-activating proteins (GAPs) have been identified at cell-cell junctions at various stages of junction maturation. As opposed to RhoGEFs and RhoGAPs, the role of Rho GDP dissociation inhibitors (GDIs) during cell-cell contact formation is poorly understood. Here, we have analyzed the role of RhoGDI1/ARHGDIA, a member of the RhoGDI family, during cell-cell contact formation of polarized epithelial cells. Depletion of RhoGDI1 delays the development of linear cell-cell junctions and the formation of barrier-forming tight junctions. In addition, RhoGDI1 depletion impairs the ability of cells to stop migration in response to cell collision and increases the migration velocity of collectively migrating cells. We also find that the cell adhesion receptor JAM-A promotes the recruitment of RhoGDI1 to cell-cell contacts. Our findings implicate RhoGDI1 in various processes involving the dynamic reorganization of cell-cell junctions.

3.
Int J Dermatol ; 2024 Aug 02.
Article de Anglais | MEDLINE | ID: mdl-39092474

RÉSUMÉ

INTRODUCTION: Chronic actinic dermatitis (CAD) is an immunologically mediated photodermatosis that has been effectively treated with azathioprine and mycophenolate mofetil (MMF) in uncontrolled studies. We conducted a prospective randomized controlled trial to compare the efficacy and safety of azathioprine and MMF in CAD treatment, aiming to address existing evidence gaps. MATERIALS AND METHODS: Consecutive CAD patients were randomized into two groups: azathioprine (Group A) or MMF (Group B) for 12 weeks. Primary outcomes included Eczema Area and Severity Index (EASI) and Dermatology Life Quality Index (DLQI) at baseline and Week 12. Secondary outcomes included various clinicodemographic factors predictive of treatment response, defined at least a 75% reduction in EASI score (EASI75) by Week 12. RESULTS: The median (IQR) percentage reduction in EASI at 12 weeks was higher in Group B than in Group A [78.3% (75.0-83.30%) vs. 68.3% (31.2-80.10%), P = 0.034]. Baseline DLQI scores indicated a moderate impact on quality of life, with significant reductions by Week 12 in both groups and no intergroup differences at baseline (P = 0.291) or Week 12 (P = 0.599). Overall, 23 patients were classified as non-responders, with more extended illness duration (P = 0.026) and outdoor occupations (P = 0.042) associated with poorer responses. Adverse effects were consistent with known profiles, with one patient discontinuing azathioprine due to hypersensitivity. CONCLUSION: Our study highlights the efficacy and safety of azathioprine and MMF in CAD treatment, with MMF showing superior outcomes. However, further research is warranted to explore emerging therapies and prognostic factors in CAD management.

4.
Adv Mater ; : e2409261, 2024 Aug 02.
Article de Anglais | MEDLINE | ID: mdl-39092687

RÉSUMÉ

The bottom contact in perovskite solar cells (PSCs) is easy to cause deep trap states and severe instability issues, especially under maximum power point tracking (MPPT). In this study, sodium gluconate (SG) is employed to disperse tin oxide (SnO2) nanoparticles (NPs) and regulate the interface contact at the buried interface. The SG-SnO2 electron transfer layer (ETL) enabled the deposition of pinhole-free perovskite films in ambient air and improved interface contact by bridging effect. SG-SnO2 PSCs achieved an impressive power conversion efficiency (PCE) of 25.34% (certified as 25.17%) with a high open-circuit voltage (VOC) exceeding 1.19 V. The VOC loss is less than 0.34 V relative to the 1.53 eV bandgap, and the fill factor (FF) loss is only 2.02% due to the improved contact. The SG-SnO2 PSCs retained around 90% of their initial PCEs after 1000 h operation (T90 = 1000 h), higher than T80 = 1000 h for the control SnO2 PSC. Microstructure analysis revealed that light-induced degradation primarily occurred at the buried holes and grain boundaries and highlighted the importance of bottom-contact engineering.

5.
ACS Sens ; 2024 Aug 08.
Article de Anglais | MEDLINE | ID: mdl-39115965

RÉSUMÉ

Ion-selective electrodes (ISEs) have widespread use in the fields of clinical and environmental analyses. Tetrahydrofuran (THF) is the most used solvent for the preparation of modern ISEs, equipped with ion-selective membranes (ISMs). Until now, the influence of impurities in THF toward potentiometric instability of ion-selective membrane based ISEs was probably associated with the presence of either residual water or peroxide. To address this issue, most literature recommends redistilling THF prior to use in the preparation of the potentiometric membranes. Current study reveals that the actual THF impurity that is responsible for potential instability in the ISM includes products from the oxidation of THF, which contains the hydroxyl group and possibly carbonyl group with a boiling point of above 200 °C. The density functional theory calculation supported pathway of the chemical reaction of THF oxidation, hence, the chemical structure of the uncertain impurities was predicted. The underlying reason for the deteriorating potential stability of the ISEs is proposed as the significant hydrophilicity of these impurities that affect the partitioning of the ion sensing components in the membrane, thus enhancing the leaching of the membrane components from the membrane phase. This finding explains why redistillation of aged THF is advised.

6.
BMC Med Res Methodol ; 24(1): 173, 2024 Aug 08.
Article de Anglais | MEDLINE | ID: mdl-39118030

RÉSUMÉ

OBJECTIVE: In order to facilitate the tracing of infectious diseases in a small area and to effectively carry out disease control and epidemiological investigations, this research proposes a novel spatiotemporal model to estimate effective reproduction number(Re)for infectious diseases, based on the fundamental concept of contact tracing. METHODS: This study utilizes the incidence of hand, foot, and mouth disease (HFMD) among children in Bishan District, Chongqing, China from 2015 to 2019. The study incorporates the epidemiological characteristics of HFMD and aims to construct a Spatiotemporal Correlation Discrimination of HFMD. Utilizing ARC ENGINE and C# programming for the creation of a spatio-temporal database dedicated to HFMD to facilitate data collection and analysis. The scientific validity of the proposed method was verified by comparing the effective reproduction number obtained by the traditional SEIR model. RESULTS: We have ascertained the optimal search radius for the spatiotemporal search model to be 1.5 km. Upon analyzing the resulting Re values, which range from 1.14 to 4.75, we observe a skewed distribution pattern from 2015 to 2019. The median and quartile Re value recorded is 2.42 (1.98, 2.72). Except for 2018, the similarity coefficient r of the years 2015, 2016, 2017, and 2019 were all close to 1, and p <0.05 in the comparison of the two models, indicating that the Re values obtained by using the search model and the traditional SEIR model are correlated and closely related. The results exhibited similarity between the Re curves of both models and the epidemiological characteristics of HFMD. Finally, we illustrated the regional distribution of Re values obtained by the search model at various time intervals on Geographic Information System (GIS) maps which highlighted variations in the incidence of diseases across different communities, neighborhoods, and even smaller areas. CONCLUSION: The model comprehensively considers both temporal variation and spatial heterogeneity in disease transmission and accounts for each individual's distinct time of onset and spatial location. This proposed method differs significantly from existing mathematical models used for estimating Re in that it is founded on reasonable scientific assumptions and computer algorithms programming that take into account real-world spatiotemporal factors. It is particularly well-suited for estimating the Re of infectious diseases in relatively stable mobile populations within small geographical areas.


Sujet(s)
Syndrome mains-pieds-bouche , Analyse spatio-temporelle , Syndrome mains-pieds-bouche/épidémiologie , Humains , Chine/épidémiologie , Taux de reproduction de base/statistiques et données numériques , Incidence , Enfant , Maladies transmissibles/épidémiologie , Enfant d'âge préscolaire , Femelle , Mâle , Modèles épidémiologiques
7.
Contact Dermatitis ; 2024 Aug 08.
Article de Anglais | MEDLINE | ID: mdl-39118172

RÉSUMÉ

BACKGROUND: The woods of trees of the genus Dalbergia are a frequent cause of allergic contact dermatitis. OBJECTIVES: To describe the different patterns of symptoms and sensitisation to woods of the genus Dalbergia in four patients whose regular work is linked to music, either as performers (two patients) or instrument makers. RESULTS: The patients showed extensive cross-reactivity between the different Dalbergia woods. The two musicians exhibited symptoms exclusively in the contact areas, while the instrument makers showed a pattern of airborne symptoms. The period from sensitisation to the development of symptoms varied greatly among the patients. CONCLUSIONS: The symptoms of allergic contact dermatitis to Dalbergia woods differ markedly depending on the route of contact. Cross-reactivity between the woods of this genus is very wide. The sensitising potential varies between the various Dalbergia woods, which require different contact periods depending on their sensitising power.

8.
Adv Sci (Weinh) ; : e2407045, 2024 Aug 09.
Article de Anglais | MEDLINE | ID: mdl-39120024

RÉSUMÉ

Contact lenses have been instrumental in vision correction and are expected to be utilized in augmented reality (AR) displays through the integration of electronic and optical components. In optics, metasurfaces, an array of sub-wavelength nanostructures, have offered optical multifunctionality in an ultra-compact form factor, facilitating integration into various imaging, and display systems. However, transferring metasurfaces onto contact lenses remains challenging due to the non-biocompatible materials of extant imprinting methods and the structural instability caused by the swelling and shrinking of the wetted surface. Here, a biocompatible method is presented to transfer metasurfaces onto contact lenses using hyaluronic acid (HA) as a soft mold and to allow for holographic light projection. A high-efficiency metahologram is obtained with an all-metallic 3D meta-atom enhanced by the anisotropy of a rectangular structure, and a reflective background metal layer. A corrugated metal layer on the HA mold is supported with a SiO2 capping layer, to avoid unwanted wrinkles and to ensure structural stability when transferred to the surface of pliable and wettable contact lenses. Biocompatible method of transferring metasurfaces onto contact lenses promises the integration of diverse optical components, including holograms, lenses, gratings and more, to advance the visual experience for AR displays and human-computer interfaces.

9.
EFSA J ; 22(8): e8960, 2024 Aug.
Article de Anglais | MEDLINE | ID: mdl-39104808

RÉSUMÉ

The EFSA Panel on Food Contact Materials (FCM) assessed the safety of the substances 'wax, rice bran, oxidised' and 'wax, rice bran, oxidised, calcium salt', used as additives up to 0.3% in polyethylene terephthalate (PET), polyamide (PA), thermoplastic polyurethane (TPU), polylactic acid (PLA) and poly(vinyl chloride) (PVC) in contact with all food types for long-term storage at room temperature and below, after hot-fill and/or heating. The substances consist of the chemical classes wax esters, carboxylic acids, alcohols and calcium salts of acids, along with an unidentified organic fraction up to ■■■■■ w/w. Migration into 10% ethanol and 4% acetic acid was below 0.012 mg/kg for each chemical class, and about 0.001 mg/kg for the unidentified fraction. In isooctane, migration was up to 0.297 mg/kg food for wax esters, below 0.01 mg/kg food for the other chemical classes and about 0.02 mg/kg food for the unidentified fraction. The contact with dry food and food simulated by 20% ethanol were considered covered by the migration tests with aqueous simulants. Based on genotoxicity assays and compositional analyses, the constituents of the chemical classes did not raise a concern for genotoxicity. The potential migration of individual constituents or groups of chemically-related compounds of the unidentified fraction would result in exposures below (for aqueous food) and above (for fatty food) the threshold of toxicological concern for genotoxic carcinogens. Therefore, the FCM Panel concluded that the substances are not of safety concern for the consumer, if used as additives up to 0.3% w/w in PET, PLA and rigid PVC materials and articles intended for contact with all food types except for fatty foods, for long-term storage at room temperature and below, including hot-fill and/or heating up to 100°C for up to 2 h.

10.
Food Chem ; 460(Pt 2): 140657, 2024 Jul 30.
Article de Anglais | MEDLINE | ID: mdl-39106809

RÉSUMÉ

In recent years, the wine industry has shifted towards plant-based fining agents for food safety reasons and consumer preferences. This study analysed the interaction of five plant fibers with red wine phenolic compounds to determinate their performance as fining agents. Chemical composition, polysaccharide profile, and physical properties were examined. Pea, cellulose, and Sauvignon Blanc pomace fibers effectively reduced tannin content while minimally affecting the concentration of anthocyanins, flavonols and wine color. Contrary to previous beliefs, the presence of pectins in fibers didn't play a crucial role in phenolic compound interaction since cellulose-rich fibers with low pectin concentration also bound tannins effectively, especially those with small particle size and high contact surface. Pea fiber, rich in cellulose and pectins, showed remarkable tannin retention while minimally affecting wine color. This research highlights the potential of plant fibers as effective fining agents in wine production and how their composition affects their performance.

11.
Cont Lens Anterior Eye ; : 102285, 2024 Aug 05.
Article de Anglais | MEDLINE | ID: mdl-39107158

RÉSUMÉ

PURPOSE: Extended wear has long been considered as the ultimate contact lens modality in terms of user convenience. The purpose of this work is to update earlier surveys by describing international trends in extended wear soft lens fitting between 2000 and 2023, inclusive. METHOD: An annual contact lens prescribing survey was sent to eye care practitioners in up to 71 countries between 2000 and 2023, inclusive. Data relating to 282,142 soft contact lens fits undertaken in 20 countries returning reliable longitudinal data were analysed in respect of extended wear soft lens fitting. RESULTS: Over the duration of the work there was a very small decrease in the prescribing of extended wear soft lenses (p < 0.0001). More detailed inspection shows that prescribing of these lenses steadily increased from 5.8 % of all soft lens fits in 2000 to 11.6 % in 2007, then steadily decreased to 5.2 % in 2023. Of all soft contact lenses prescribed to males, 9.2 % were fitted for extended wear, compared with 6.7 % for females (p < 0.0001). The mean age of extended wear soft lens wearers at fitting was 34.7 ± 14.7 years, compared to 31.1. ± 14.10 years for daily soft lens wearers (p < 0.0001). Analysis of 1,948 recent extended wear soft lens fits (2019-2023, inclusive), in terms of material type, revealed that, on average, 86 % and 14 % of extended wear soft lenses were fitted using silicone hydrogel and hydrogel materials, respectively. CONCLUSION: A modest increase in extended wear soft lens prescribing from 2000 to 2007 corresponded with the introduction of high oxygen transmissibility silicone hydrogel lenses. However, prescribing of this lens type declined thereafter, probably due to ongoing concerns over their increased rate of microbial keratitis, resulting in a prescribing rate in 2023 (5.2%) that was little different to that observed in 2000 (5.8%).

12.
Mikrochim Acta ; 191(9): 517, 2024 Aug 06.
Article de Anglais | MEDLINE | ID: mdl-39107632

RÉSUMÉ

Solid-state contact ion-selective electrodes (SC-ISEs) are an efficacious means of monitoring heavy metal contamination. Instability of the electrode potential is a key factor limiting their development, with biofouling in real water samples posing a significant challenge to maintaining stability. Therefore, addressing biofouling is crucial for optimizing solid-state ion-selective electrodes. In this work, high stability and antibiofouling capability in a solid-state contact lead ion-selective electrode (SC-Pb2+-ISE) based on polyaniline (PANI) was achieved through cathodic polarization. Specifically, PANI played a dual role in the ion-selective membrane (ISM) as an ion-to-electron transducer and antifouling agent. Given the excellent electrochemical performance of PANI, the prepared electrode (GC/PANI-Pb2+-ISM) demonstrated a remarkable antibiofouling efficiency of 98.2% under a cathodic polarization of -0.2 V. Furthermore, a standard deviation of standard potential (Eθ) as low as ± 0.5 mV was realized successfully. The excellent chrono-potentiometric stability of 17.0 ± 2.9 µV/s was also demonstrated. The electrode maintained a Nernstian response slope of 30.7 ± 0.2 (R2 = 0.998) after applying a cathode potential (-0.2 V) for 30 min. The developed GC/PANI-Pb2+-ISM electrode is suitable for practical applications in real environmental water sample monitoring.

13.
Article de Anglais | MEDLINE | ID: mdl-39107948

RÉSUMÉ

BACKGROUND: When using lesion size index (LSI) to guide catheter ablation, it is unclear what combination of power, contact force and time would be preferable to use and what LSI target value to aim for. This study aimed at identifying desirable ablation settings and LSI targets by using tissue impedance drop as indicator of lesion formation. METHODS: Consecutive patients, undergoing their first left atrial (LA) catheter ablation for atrial fibrillation, with radiofrequency energy (RF) powers of 20, 30 and 40 W were enrolled. Tissue impedance, contact force (CF), Force Time Integral (FTI) and LSI values were continuously recorded during ablation and sampled at 100 Hz. Mean CF and Contact Force Variability (CFV) were calculated for every lesion. The effect of RF power, ablation time, CF and CFV on impedance drop and LSI were assessed. RESULTS: A total of 3258 lesions were included in the analysis. For any target LSI value, use of higher RF powers translated into progressively higher impedance drops. The impact of lower CF and higher CFV on impedance drop was more relevant when using lower powers. Target LSI values corresponding to maximum impedance drop were identified depending on RF power, mean CF and CFV used. CONCLUSIONS: Even in the context of an LSI-guided ablation strategy, use of lower or higher powers might lead to different lesion sizes. Different LSI targets might be needed depending on the combination of RF power, CF and CFV used for ablation. Incorporating indicators of catheter stability, like CFV, in the LSI formula could improve the predictive value of LSI for lesion size. Studies with clinical outcomes are required to confirm the clinical relevance of these findings.

14.
Front Neurosci ; 18: 1457590, 2024.
Article de Anglais | MEDLINE | ID: mdl-39108309

RÉSUMÉ

[This corrects the article DOI: 10.3389/fnins.2024.1349436.].

15.
Evolution ; 2024 Aug 07.
Article de Anglais | MEDLINE | ID: mdl-39110094

RÉSUMÉ

Range expansion and contraction are among the most common biotic responses to changing environmental conditions, yet much is to be learned about the mechanisms that underlie range-edge population dynamics, especially when those areas are points of secondary contact between closely related species. Here, we present field-measured parentage data that document the reproductive outcomes of changes in mate availability at a secondary contact zone between two species of woodrat in the genus Neotoma. Changes in mate availability resulted from drought-driven differential survival between the species and their hybrids. As the availability of conspecific mates declined, rates of hybridization increased, leading to the accumulation of admixed individuals in the zone of contact. Patterns of reproductive success in the wild appear to be the result of a combination of both pre-mating isolation and post-zygotic selection resulting from genomic incompatibilities between the parental lineages. Evidence of asymmetric mate preference between the parental lineages came from both skewed reproductive output in the field and laboratory preference trials. Moreover, partial genomic incompatibility was evident from the near-zero reproductive success of F1 males and because nearly all surviving hybrids had one pure parent. Nonetheless, high reproductive success of F1 females and backcrossing in both parental directions allow for introgression between the parental species. These findings reveal how climate change may alter evolutionary outcomes for species at the edge of their ranges through an interplay of behavioral, demographic, and genetic mechanisms.

16.
Article de Anglais | MEDLINE | ID: mdl-39110197

RÉSUMÉ

PURPOSE: To evaluate tear meniscus parameters in soft contact lens wearers (SCL) using optical coherence tomography (OCT) and ImageJ software. METHODS: This prospective study included 50 soft contact lens wearers (group 1: 25 symptomatic SCL wearers (SCLW), group 2: 25 asymptomatic SCL wearers (ASCW)) and 25 healthy non-CL wearers (group 3 (NCLW)). SCLs were fitted on each eye of CL wearers, and the lower tear meniscus was imaged using OCT before CL insertion, immediately afterward, and reimaged 2, 5 and 10 h after insertion. Tear meniscus parameters, including tear meniscus height (TMH), depth (TMD), turbidity, and percentage area occupied by particles (PAOP) were measured in all groups. RESULTS: Turbidity and PAOP measurements at baseline in SCLW were significantly higher than in other groups (p < 0.05). There was no significant difference between TMH, TMD, turbidity, and PAOP parameters calculated at baseline visit and two hours after SCL insertion in all groups (p > 0.05 for 2 comparisons). The symptomatic SCL users had a significant decrease in TMH and TMD in the fifth hour. The turbidity and PAOP measurements of SCLW and ASCW at the fifth and tenth hours were significantly higher than those of NCLW (p < 0.05). CONCLUSION: TMD and height TMH decrease throughout the day in all participants; however, a significant decrease in these parameters was observed only in symptomatic SCL users at the fifth hour, at the earliest. As the duration of CL wear increases, turbidity and PAOP even in asymptomatic SCL wearers become significantly higher than those in healthy non-CL wearers. KEY MESSAGES: What Is Known • Contact lens wear is associated with an increased risk of dry eye. • Tear volume decreases gradually during contact lens wear. What Is New • Tear meniscus turbidity and particle area occupied by particles (PAOP) were higher in symptomatic contact lens wearers and they increase gradually during contact lens wear. • Tear meniscus turbidity and PAOP may be measures of how well the tear film and meniscus are functioning in contact lens wearers.

17.
Sci Rep ; 14(1): 17848, 2024 08 01.
Article de Anglais | MEDLINE | ID: mdl-39090157

RÉSUMÉ

Case investigation and contact tracing (CICT) are public health measures that aim to break the chain of pathogen transmission. Changes in viral characteristics of COVID-19 variants have likely affected the effectiveness of CICT programs. We estimated and compared the cases averted in Vermont when the original COVID-19 strain circulated (Nov. 25, 2020-Jan. 19, 2021) with two periods when the Delta strain dominated (Aug. 1-Sept. 25, 2021, and Sept. 26-Nov. 20, 2021). When the original strain circulated, we estimated that CICT prevented 7180 cases (55% reduction in disease burden), compared to 1437 (15% reduction) and 9970 cases (40% reduction) when the Delta strain circulated. Despite the Delta variant being more infectious and having a shorter latency period, CICT remained an effective tool to slow spread of COVID-19; while these viral characteristics did diminish CICT effectiveness, non-viral characteristics had a much greater impact on CICT effectiveness.


Sujet(s)
COVID-19 , Traçage des contacts , Santé publique , SARS-CoV-2 , COVID-19/épidémiologie , COVID-19/prévention et contrôle , COVID-19/transmission , COVID-19/virologie , Traçage des contacts/méthodes , Vermont/épidémiologie , Humains , SARS-CoV-2/isolement et purification
18.
Elife ; 122024 Aug 06.
Article de Anglais | MEDLINE | ID: mdl-39106189

RÉSUMÉ

Numerous lipids are heterogeneously distributed among organelles. Most lipid trafficking between organelles is achieved by a group of lipid transfer proteins (LTPs) that carry lipids using their hydrophobic cavities. The human genome encodes many intracellular LTPs responsible for lipid trafficking and the function of many LTPs in defining cellular lipid levels and distributions is unclear. Here, we created a gene knockout library targeting 90 intracellular LTPs and performed whole-cell lipidomics analysis. This analysis confirmed known lipid disturbances and identified new ones caused by the loss of LTPs. Among these, we found major sphingolipid imbalances in ORP9 and ORP11 knockout cells, two proteins of previously unknown function in sphingolipid metabolism. ORP9 and ORP11 form a heterodimer to localize at the ER-trans-Golgi membrane contact sites, where the dimer exchanges phosphatidylserine (PS) for phosphatidylinositol-4-phosphate (PI(4)P) between the two organelles. Consequently, loss of either protein causes phospholipid imbalances in the Golgi apparatus that result in lowered sphingomyelin synthesis at this organelle. Overall, our LTP knockout library toolbox identifies various proteins in control of cellular lipid levels, including the ORP9-ORP11 heterodimer, which exchanges PS and PI(4)P at the ER-Golgi membrane contact site as a critical step in sphingomyelin synthesis in the Golgi apparatus.


Sujet(s)
Réticulum endoplasmique , Sphingomyéline , Sphingomyéline/métabolisme , Sphingomyéline/biosynthèse , Humains , Réticulum endoplasmique/métabolisme , Appareil de Golgi/métabolisme , Protéines de transport/métabolisme , Protéines de transport/génétique , Multimérisation de protéines , Récepteurs aux stéroïdes/métabolisme , Récepteurs aux stéroïdes/génétique , Techniques de knock-out de gènes , Phosphates phosphatidylinositol/métabolisme , Phosphates phosphatidylinositol/biosynthèse
19.
Contact (Thousand Oaks) ; 7: 25152564231223480, 2024.
Article de Anglais | MEDLINE | ID: mdl-39108634

RÉSUMÉ

In this News and Views, I discuss our recent publication that established how steroidogenic acute regulatory-related lipid transfer domain-3 (STARD3), a membrane contact protein situated at lysosomal membranes, plays a role in the detoxification of cholesterol hydroperoxide. STARD3's methionine residues can be oxidized to methionine sulfoxide by cholesterol hydroperoxide, after which methionine sulfoxide reductases reduce the methionine sulfoxide residues back to methionine. The reaction also results in the reduction of the cholesterol hydroperoxide to an alcohol. The cyclic oxidation and reduction of methionine residues in STARD3 at membrane contact sites creates a catalytically efficient mechanism for detoxification of cholesterol hydroperoxide during cholesterol transport, thus protecting membrane contact sites and the entire cell against the toxicity of cholesterol hydroperoxide.

20.
Front Sports Act Living ; 6: 1419088, 2024.
Article de Anglais | MEDLINE | ID: mdl-39108981

RÉSUMÉ

Introduction: Basketball, introduced by Naismith as a contactless and indoor alternative to sports such as American football, now frequently involves physical contact among players, challenging the traditional notion. Up to date, a thorough understanding of these contacts and their implications remains limited. This study aims to analyze player contacts, embedding it within overall load monitoring to optimize performance and reduce injury risk. Methods: Using a mixed-method design, video-based observations and quantitative analysis were employed to study contact characteristics during ten professional male basketball matches. Fisher exact tests and chi-squared tests (p < .05) were conducted to examine positional variations across different contact variables. Results: A total of 2,069 player contacts were examined, showing centers had the most contacts at 40.5%, followed by power forwards (19.6%), point guards (17.7%), shooting guards (12.9%), and small forwards (9.3%). Notably, half-court defense (46.1%) and set offense (48.9%) emerged as the primary game phases associated with the majority of contacts across all playing positions. Key play actions leading to physical contact included screening/picking (25.7%), box outs (22.9%), and fights for position (FFP) (18%). Post hoc analyses identified significant associations between centers (32.6%, 5.93) and point guards (21.5%, -1.98) during screening/picking maneuvers. Moreover, the torso/upper body (48.1%) and upper extremities (38.2%) were identified as the most affected contact points, while lower extremities and the head/neck exhibited minimal impact. Additionally, 81.4% (n = 1,684) of contacts resulted in kinematic displacement, whereas 18.6% (n = 385) exhibited no change. Post hoc analyses indicated significant associations of physical contacts against opposing counterparts for each playing position. Discussion: Basketball entails frequent physical contacts across all playing positions, with distinct patterns observed for each playing position. Integrating contact monitoring alongside traditional load metrics offers a more comprehensive understanding of physical demands in professional basketball. Practical implications include the developing of tailored training strategies based on playing position-specific contact profiles and recognizing the physiological and biomechanical impacts of contacts. Future research should consider whether the number of contacts between players has increased over the years, and it should acknowledge the impact of player contacts on performance in basketball in order to refine training strategies and enhance player well-being.

SÉLECTION CITATIONS
DÉTAIL DE RECHERCHE