Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 331
Filtrar
1.
J Orthop ; 59: 76-81, 2025 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39351272

RESUMO

Aim & objectives: To evaluate functional and radiological outcomes of Free Vascularized Fibula grafting in management of Covid-19 associated Osteonecrosis of Femur Head. Design: Prospective Case Series. Methods: 14 hips (10 patients) with ONFH following COVID-19 were treated with Free Vascularized Fibula graft from June 2021 to December 2022 and were subsequently evaluated monthly for 6 months and then every 3 months post operatively for functionality (Harris Hip Score), Femur head collapse and related complications. Results: Mean age of patients was 29.3 years (Range: 20-38 years). 14 diseased hips were classified on the basis of Steinberg classification as 4 stage 2B, 4 stage 3B and 6 stage 3C. The average follow up period was 2.1 years (Range: 12 months-34 months).Eight of fourteen hips survived and six progressed to collapse. Mean HHS at final follow-up was 68.3 in comparison to 65.8 pre-operatively. 4 fair and 4 poor HH scores were converted to 4 excellent and 4 good scores post-operatively.Two late complications were noted-one FHL contracture and one CPN neuroma. Conclusion: Free Vascularized Fibula Graft, as a hip salvage modality, showed optimal results in the treatment of COVID-19 related ONFH, which is associated with aggressive disease course and extensive involvement of femur head.

2.
J Pharm Sci ; 2024 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-39245324

RESUMO

Multiple iterations required to design ocular implants, which will last for the desired operational period of months or even years, necessitate the use of in-silico models for ocular drug delivery. In this study, we developed an in-silico model to simulate the flow of Aqueous Humor (AH) and drug delivery from an implant to the Trabecular Meshwork (TM). The implant, attached to the side of the intraocular lens (IOL), and the TM are treated as porous media, with their effects on AH flow accounted for using the Darcy equation. This model accurately predicts the physiological values of Intraocular Pressure (IOP) for both healthy individuals and glaucoma patients, as reported in the literature. Results reveal that the effective diffusivity of the drug within the implant is the critical parameter that can alter the bioavailability time period (BTP) from a few days to months. Intuitively, BTP should increase as effective diffusivity decreases. However, we discovered that with lower levels of initial drug loading, BTP declines when effective diffusivity falls below a specific threshold. Our findings further reveal that, while AH flow has a minimal effect on the drug release profile at the implant site, it significantly impacts drug availability at the TM.

3.
Chem Biodivers ; : e202401010, 2024 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-39175307

RESUMO

Cancer is a chronic disease reported with alarming rates of mortalities every year.  Herein, we reported the synthesis of nitrogen based novel heterocyclic disubstituted derivatives and evaluated them against L929 and A549 cell lines using MTT assay. Among all, 6a2 and 6c1 were significantly active against L929 with IC50 value of 2.61±9.58 and 2.64±8.97 µg/mL respectively. Compounds 6a2 and 6c1 were also active against A549 with IC50 value of 2.36±9.20 and 2.43±6.28 µg/mL respectively and were found to be more potent than the standard drug Doxorubicin. A molecular docking study of the active compounds was also done against EGFR, conferring good binding affinity and binding interactions. Further biological investigations may provide valuable insights towards exploring the therapeutic potential of the active compounds in future.

4.
ACS Nano ; 18(35): 24379-24390, 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39159430

RESUMO

The emerging moiré superstructure of twisted transition metal dichalcogenides (TMDs) leads to various correlated electronic and optical properties compared to those of twisted bilayer graphene. In such a versatile architecture, phonons can also be renormalized and evolve due to atomic reconstruction, which, in turn, depends on the twist angle. However, observing this reconstruction and its relationship to phonon behavior with conventional, cost-effective imaging methods remains challenging. Here, we used noninvasive Raman spectroscopy on twisted WSe2/WSe2 (t-WSe2) homobilayers to examine the evolution of phonon modes due to interlayer coupling and atomic reconstruction. Unlike in the natural bilayer (NB), ∼0° as well as ∼60° t-WSe2 samples, the nearly degenerate A1g/E2g mode in the twisted samples (1-7°) split into a doublet in addition to the nondegenerate B2g mode, and the maximum splitting is observed around 2-3°. Our detailed theoretical calculations qualitatively capture the splitting and its dependence as a function of the twist angle and highlight the role of the moiré potential in phonon hybridization. Additionally, we found that around the 2° twist angle, the anharmonic phonon-phonon interaction is higher than the natural bilayer and decreases for larger twist angles. Interestingly, we observed anomalous Raman frequency softening and line-width increase with the decreasing temperature below 50 K, pointing to the combined effect of enhanced electron-phonon coupling and cubic anharmonic interactions in moiré superlattice.

5.
Indian J Nephrol ; 34(3): 246-251, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39114397

RESUMO

Background: The role of induction in low-risk, living-donor kidney transplants being treated with tacrolimus, mycophenolate mofetil, and prednisolone is debatable. Materials and Methods: This was a retrospective study that consisted of patients undergoing living kidney transplantation between February 2010 and June 2021 with a related haplomatch donor, with maintenance immunosuppression of tacrolimus, mycophenolate mofetil, and prednisolone. High-risk transplants, such as second or more transplants, immunologically incompatible transplants, and steroid-free transplants, were excluded. Patients were divided into three groups: no induction, basiliximab induction, and thymoglobulin induction, and the outcomes of all three were compared. Results: A total of 350 transplants were performed. There was a significant difference in the recipient sex distribution (P = 0.0373) and the number of preemptive transplants (P = 0.0272) between the groups. Other parameters were comparable. Biopsy-proven acute rejection (BPAR) was significantly less frequent in the thymoglobulin group than in the no-induction (5.3% vs. 17.5%; P = 0.0051) or basiliximab (5.3% vs. 18.8%; P = 0.0054) group. This persisted even after we performed multivariate regression analysis (thymoglobulin vs. no-induction group, P = 0.0146; thymoglobulin vs. basiliximab group, P = 0.0237). There was no difference in BPAR between the basiliximab and no-induction groups. There were no differences in other outcomes between the groups. Conclusion: In a low-risk haplomatch, related, living-donor kidney transplant on tacrolimus, mycophenolate mofetil, and prednisolone, BPAR was significantly lower with thymoglobulin as opposed to no induction or basiliximab induction with a similar short-term patient and death-censored graft survival and infection rates. Basiliximab did not provide any benefit over no induction.

6.
Water Environ Res ; 96(8): e11110, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39155465

RESUMO

This study introduces draw solutions for application in forward osmosis (FO) processes, combining mono propylene glycol propyl ether (PGPE) with the cellulose derivative hydroxypropyl cellulose (HPC). A total of 16 unique single-solute and ternary organic draw solutions were prepared and evaluated, leading to the selection of three promising solutions for further investigation. Notably, eight of the initial organic draw solutions demonstrated osmotic pressures exceeding 2.4 MPa. The dynamic viscosities of all draw solutions exhibited a significant reduction with increasing temperature. Among the investigated solutions, the 0.25HPC-3.75PGPE demonstrated the most favorable FO performance, achieving average experimental water fluxes of 11.062 and 9.852 Lm-2 h-1 (LMH) against a 1 g/L NaCl brackish feed solution across two FO runs. PRACTITIONER POINTS: Hydroxypropyl cellulose (HPC, MW ~100,000) was mixed with propylene glycol propyl ether (PGPE) as draw solutes for FO processes. Seven combinations of HPC and PGPE produced osmolalities greater than 1000 mOsm/kg. 0.5HPC-7.5PGPE ternary draw solution achieved experimental water fluxes of 11.062 and 9.852 LMH against 1 g/L NaCl brackish feed solution. Leveraging the LCSTs of these ternary organic solutions holds promise for improved separation and regeneration processes.


Assuntos
Celulose , Osmose , Águas Salinas , Purificação da Água , Celulose/química , Celulose/análogos & derivados , Purificação da Água/métodos , Águas Salinas/química , Propilenoglicóis/química
7.
Life Sci ; 352: 122908, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39004270

RESUMO

AIM: Coronary artery disease (CAD) is the leading cause of mortality. Though percutaneous transluminal angioplasty followed by stenting is still the default treatment of choice for revascularization of obstructive CAD, the high rate of restenosis compromises the outcomes of endovascular procedures. To overcome restenosis, drug-eluting stents (DES) and drug-coated balloons (DCB) are designed that release antiproliferative drugs like sirolimus, paclitaxel, everolimus, etc., over time to inhibit cell growth and proliferation. Our review aims to summarize the challenges and progress of DES/DCBs in clinical settings. MATERIAL AND METHODS: The comprehensive review, search and selection encompasses in relevant articles through Google Scholar, Springer online, Cochrane library and PubMed that includes research articles, reviews, letters and communications, various viewpoints, meta-analyses, randomized trials and quasi-randomized trials. Several preclinical and clinical data have been included from National Institutes of Health and clinicaltrials.gov websites. KEY FINDINGS: Challenges like delayed endothelialization, stent thrombosis (ST), and inflammation was prominent in first-generation DES. Second-generation DES with improved designs and drug coatings enhanced biocompatibility with fewer complications. Gradual absorption of bioresorbable DES over time mitigated long-term issues associated with permanent implants. Polymer-free DES addressed the inflammation concerns but still, they leave behind metallic stents in the vasculature. As an alternative therapeutic strategy, DCB were developed to minimize inflammation in the vessel. Although both DES and DCBs have shown considerable progress, challenges persist. SIGNIFICANCE: This review illustrates the advancements in the designs, preparation technologies, biodegradable materials, and drugs used as well as challenges associated with DES and DCBs in clinical settings.


Assuntos
Doença da Artéria Coronariana , Stents Farmacológicos , Humanos , Doença da Artéria Coronariana/terapia , Materiais Revestidos Biocompatíveis , Animais , Reestenose Coronária/prevenção & controle , Angioplastia Coronária com Balão/métodos , Paclitaxel/administração & dosagem , Paclitaxel/uso terapêutico
8.
Nano Lett ; 24(30): 9245-9252, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39012311

RESUMO

At near-parallel orientation, twisted bilayers of transition metal dichalcogenides exhibit interlayer charge transfer-driven out-of-plane ferroelectricity. Here, we report detailed electrical transport in a dual-gated graphene field-effect transistor placed on a 2.1° twisted bilayer WSe2. We observe hysteretic transfer characteristics and an emergent charge inhomogeneity with multiple local Dirac points evolving with an increasing electric displacement field (D). Concomitantly, we also observe a strong nonlocal voltage signal at D ∼ 0 V/nm that decreases rapidly with increasing D. A linear scaling of the nonlocal signal with longitudinal resistance suggests edge mode transport, which we attribute to the breaking of valley symmetry of graphene due to the spatially fluctuating electric field from the underlying polarized moiré domains. A quantitative analysis suggests the emergence of finite-size domains in graphene that modulate the charge and the valley currents simultaneously. This work underlines the impact of interfacial ferroelectricity that can trigger a new generation of devices.

9.
Vaccine ; 42(24): 126077, 2024 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-38960788

RESUMO

BACKGROUND: India aims to eliminate rubella and congenital rubella syndrome (CRS) by 2023. We conducted serosurveys among pregnant women to monitor the trend of rubella immunity and estimate the CRS burden in India following a nationwide measles and rubella vaccination campaign. METHODS: We surveyed pregnant women at 13 sentinel sites across India from Aug to Oct 2022 to estimate seroprevalence of rubella IgG antibodies. Using age-specific seroprevalence data from serosurveys conducted during 2017/2019 (prior to and during the vaccination campaign) and 2022 surveys (after the vaccination campaign), we developed force of infection (FOI) models and estimated incidence and burden of CRS. RESULTS: In 2022, rubella seroprevalence was 85.2% (95% CI: 84.0, 86.2). Among 10 sites which participated in both rounds of serosurveys, the seroprevalence was not different between the two periods (pooled prevalence during 2017/2019: 83.5%, 95% CI: 82.1, 84.8; prevalence during 2022: 85.1%, 95% CI: 83.8, 86.3). The estimated annual incidence of CRS during 2017/2019 in India was 218.3 (95% CI: 209.7, 226.5) per 100, 000 livebirths, resulting in 47,120 (95% CI: 45,260, 48,875) cases of CRS every year. After measles-rubella (MR) vaccination campaign, the estimated incidence of CRS declined to 5.3 (95% CI: 0, 21.2) per 100,000 livebirths, resulting in 1141 (95% CI: 0, 4,569) cases of CRS during the post MR-vaccination campaign period. CONCLUSION: The incidence of CRS in India has substantially decreased following the nationwide MR vaccination campaign. About 15% of women in childbearing age in India lack immunity to rubella and hence susceptible to rubella infection. Since there are no routine rubella vaccination opportunities for this age group under the national immunization program, it is imperative to maintain high rates of rubella vaccination among children to prevent rubella virus exposure among women of childbearing age susceptible for rubella.


Assuntos
Anticorpos Antivirais , Síndrome da Rubéola Congênita , Vacina contra Rubéola , Rubéola (Sarampo Alemão) , Humanos , Feminino , Índia/epidemiologia , Síndrome da Rubéola Congênita/epidemiologia , Síndrome da Rubéola Congênita/prevenção & controle , Estudos Soroepidemiológicos , Gravidez , Rubéola (Sarampo Alemão)/epidemiologia , Rubéola (Sarampo Alemão)/prevenção & controle , Rubéola (Sarampo Alemão)/imunologia , Adulto , Adulto Jovem , Adolescente , Anticorpos Antivirais/sangue , Incidência , Vacina contra Rubéola/imunologia , Vacina contra Rubéola/administração & dosagem , Programas de Imunização , Prevalência , Imunoglobulina G/sangue , Vacinação , Complicações Infecciosas na Gravidez/epidemiologia , Complicações Infecciosas na Gravidez/imunologia , Complicações Infecciosas na Gravidez/prevenção & controle , Vírus da Rubéola/imunologia
10.
Neurochem Res ; 49(9): 2573-2599, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38896196

RESUMO

Autism spectrum disorders (ASD) are neurodevelopmental disorders manifested mainly in children, with symptoms ranging from social/communication deficits and stereotypies to associated behavioral anomalies like anxiety, depression, and ADHD. While the patho-mechanism is not well understood, the role of neuroinflammation has been suggested. Nevertheless, the triggers giving rise to this neuroinflammation have not previously been explored in detail, so the present study was aimed at exploring the role of glutamate on these processes, potentially carried out through increased activity of inflammatory cells like astrocytes, and a decline in neuronal health. A novel chlorpyrifos-induced paradigm of ASD in rat pups was used for the present study. The animals were subjected to tests assessing their neonatal development and adolescent behaviors (social skills, stereotypies, sensorimotor deficits, anxiety, depression, olfactory, and pain perception). Markers for inflammation and the levels of molecules involved in glutamate excitotoxicity, and neuroinflammation were also measured. Additionally, the expression of reactive oxygen species and markers of neuronal inflammation (GFAP) and function (c-Fos) were evaluated, along with an assessment of histopathological alterations. Based on these evaluations, it was found that postnatal administration of CPF had a negative impact on neurobehavior during both the neonatal and adolescent phases, especially on developmental markers, and brought about the generation of ASD-like symptoms. This was further corroborated by elevations in the expression of glutamate and downstream calcium, as well as certain cytokines and neuroinflammatory markers, and validated through histopathological and immunohistochemical results showing a decline in neuronal health in an astrocyte-mediated cytokine-dependent fashion. Through our findings, conclusive evidence regarding the involvement of glutamate in neuroinflammatory pathways implicated in the development of ASD-like symptoms, as well as its ability to activate further downstream processes linked to neuronal damage has been obtained. The role of astrocytes and the detrimental effect on neuronal health are also concluded. The significance of our study and its findings lies in the evaluation of the involvement of chlorpyrifos-induced neurotoxicity in the development of ASD, particularly in relation to glutamatergic dysfunction and neuronal damage.


Assuntos
Astrócitos , Transtorno do Espectro Autista , Clorpirifos , Ácido Glutâmico , Doenças Neuroinflamatórias , Astrócitos/metabolismo , Astrócitos/efeitos dos fármacos , Animais , Transtorno do Espectro Autista/induzido quimicamente , Transtorno do Espectro Autista/metabolismo , Ácido Glutâmico/metabolismo , Clorpirifos/toxicidade , Doenças Neuroinflamatórias/induzido quimicamente , Doenças Neuroinflamatórias/metabolismo , Doenças Neuroinflamatórias/patologia , Masculino , Ratos Wistar , Ratos , Animais Recém-Nascidos , Feminino , Inflamação/induzido quimicamente , Inflamação/metabolismo , Inflamação/patologia
11.
Trials ; 25(1): 378, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38863076

RESUMO

BACKGROUND: There is no known effective pharmacological therapy for long COVID, which is characterized by wide-ranging, multisystemic, fluctuating, or relapsing symptoms in a large proportion of survivors of acute COVID. This randomized controlled trial aims to assess the safety and efficacy of an anti-inflammatory agent colchicine, to reduce symptoms among those at high risk of developing long COVID. METHODS: This multi-centre, parallel arm, 1:1 individual randomized, placebo-controlled, double-blind superiority trial will enrol 350 individuals with persistent post-COVID symptoms. Participants will be randomized to either colchicine 0.5 mg once daily (< 70 kg) or twice daily (≥ 70 kg) or matched placebo for 26 weeks and will be followed up until 52 weeks after randomization. The primary trial objective is to demonstrate the superiority of colchicine over a placebo in improving distance walked in 6 min at 52 weeks from baseline. The secondary objectives are to assess the efficacy of colchicine compared to placebo with respect to lung function, inflammatory markers, constitutional symptoms, and mental health state. In a sub-sample of 100 participants, cardiac biomarkers of myocardial injury and myocardial oedema using MRI will be compared. DISCUSSION: Persistent inflammatory response following SARS-CoV-19 is one of the postulated pathophysiological mechanisms of long COVID. Colchicine, a low-cost anti-inflammatory agent, acts via multiple inflammatory pathways and has an established safety profile. This trial will generate evidence for an important health priority that can rapidly translate into practice. TRIAL REGISTRATION: This clinical trial has been registered prospectively on www. CLINICALTRIALS: gov with registration CTRI/2021/11/038234 dated November 24, 2021.


Assuntos
Tratamento Farmacológico da COVID-19 , COVID-19 , Colchicina , Humanos , Colchicina/uso terapêutico , Colchicina/efeitos adversos , Método Duplo-Cego , COVID-19/complicações , SARS-CoV-2 , Síndrome de COVID-19 Pós-Aguda , Anti-Inflamatórios/uso terapêutico , Anti-Inflamatórios/efeitos adversos , Inflamação/tratamento farmacológico , Doenças Cardiovasculares/prevenção & controle , Estudos Multicêntricos como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento , Adulto
12.
Science ; 384(6702): eadn6354, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38753765

RESUMO

AlphaFold2 (AF2) models have had wide impact but mixed success in retrospective ligand recognition. We prospectively docked large libraries against unrefined AF2 models of the σ2 and serotonin 2A (5-HT2A) receptors, testing hundreds of new molecules and comparing results with those obtained from docking against the experimental structures. Hit rates were high and similar for the experimental and AF2 structures, as were affinities. Success in docking against the AF2 models was achieved despite differences between orthosteric residue conformations in the AF2 models and the experimental structures. Determination of the cryo-electron microscopy structure for one of the more potent 5-HT2A ligands from the AF2 docking revealed residue accommodations that resembled the AF2 prediction. AF2 models may sample conformations that differ from experimental structures but remain low energy and relevant for ligand discovery, extending the domain of structure-based drug design.


Assuntos
Aprendizado Profundo , Descoberta de Drogas , Simulação de Acoplamento Molecular , Receptor 5-HT2A de Serotonina , Agonistas do Receptor 5-HT2 de Serotonina , Antagonistas do Receptor 5-HT2 de Serotonina , Humanos , Microscopia Crioeletrônica , Desenho de Fármacos , Descoberta de Drogas/métodos , Ligantes , Conformação Proteica , Dobramento de Proteína , Receptor 5-HT2A de Serotonina/química , Receptor 5-HT2A de Serotonina/ultraestrutura , Receptores sigma/química , Receptores sigma/metabolismo , Bibliotecas de Moléculas Pequenas/química , Agonistas do Receptor 5-HT2 de Serotonina/química , Agonistas do Receptor 5-HT2 de Serotonina/farmacologia , Antagonistas do Receptor 5-HT2 de Serotonina/química , Antagonistas do Receptor 5-HT2 de Serotonina/farmacologia
13.
BMJ Open Qual ; 13(Suppl 1)2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38719495

RESUMO

Triaging of obstetric patients by emergency care providers is paramount. It helps provide appropriate and timely management to prevent further injury and complications. Standardised trauma acuity scales have limited applicability in obstetric triage. Specific obstetric triage index tools improve maternal and neonatal outcomes but remain underused. The aim was to introduce a validity-tested obstetric triage tool to improve the percentage of correctly triaged patients (correctly colour-coded in accordance with triage index tool and attended to within the stipulated time interval mandated by the tool) from the baseline of 49% to more than 90% through a quality improvement (QI) process.A team of nurses, obstetricians and postgraduates did a root cause analysis to identify the possible reasons for incorrect triaging of obstetric patients using process flow mapping and fish bone analysis. Various change ideas were tested through sequential Plan-Do-Study-Act (PDSA) cycles to address issues identified.The interventions included introduction and application of an obstetric triage index tool, training of triage nurses and residents. We implemented these interventions in eight PDSA cycles and observed outcomes by using run charts. A set of process, output and outcome indicators were used to track if changes made were leading to improvement.Proportion of correctly triaged women increased from the baseline of 49% to more than 95% over a period of 8 months from February to September 2020, and the results have been sustained in the last PDSA cycle, and the triage system is still sustained with similar results. The median triage waiting time reduced from the baseline of 40 min to less than 10 min. There was reduction in complications attributable to improper triaging such as preterm delivery, prolonged intensive care unit stay and overall morbidity. It can be thus concluded that a QI approach improved obstetric triaging in a rural maternity hospital in India.


Assuntos
Melhoria de Qualidade , Triagem , Humanos , Triagem/métodos , Triagem/normas , Triagem/estatística & dados numéricos , Feminino , Índia , Gravidez , Hospitais Rurais/estatística & dados numéricos , Hospitais Rurais/normas , Hospitais Rurais/organização & administração , Adulto , Obstetrícia/normas , Obstetrícia/métodos
14.
Nat Commun ; 15(1): 3830, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38714672

RESUMO

One of the central challenges in condensed matter physics is to comprehend systems that have strong disorder and strong interactions. In the strongly localized regime, their subtle competition leads to glassy electron dynamics which ceases to exist well before the insulator-to-metal transition is approached as a function of doping. Here, we report on the discovery of glassy electron dynamics deep inside the good metal regime of an electron-doped quantum paraelectric system: KTaO3. We reveal that upon excitation of electrons from defect states to the conduction band, the excess injected carriers in the conduction band relax in a stretched exponential manner with a large relaxation time, and the system evinces simple aging phenomena-a telltale sign of glassy dynamics. Most significantly, we observe a critical slowing down of carrier dynamics below 35 K, concomitant with the onset of quantum paraelectricity in the undoped KTaO3. Our combined investigation using second harmonic generation technique, density functional theory and phenomenological modeling demonstrates quantum fluctuation-stabilized soft polar modes as the impetus for the glassy behavior. This study addresses one of the most fundamental questions regarding the potential promotion of glassiness by quantum fluctuations and opens a route for exploring glassy dynamics of electrons in a well-delocalized regime.

16.
Nature ; 628(8008): 664-671, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38600377

RESUMO

Bitter taste sensing is mediated by type 2 taste receptors (TAS2Rs (also known as T2Rs)), which represent a distinct class of G-protein-coupled receptors1. Among the 26 members of the TAS2Rs, TAS2R14 is highly expressed in extraoral tissues and mediates the responses to more than 100 structurally diverse tastants2-6, although the molecular mechanisms for recognizing diverse chemicals and initiating cellular signalling are still poorly understood. Here we report two cryo-electron microscopy structures for TAS2R14 complexed with Ggust (also known as gustducin) and Gi1. Both structures have an orthosteric binding pocket occupied by endogenous cholesterol as well as an intracellular allosteric site bound by the bitter tastant cmpd28.1, including a direct interaction with the α5 helix of Ggust and Gi1. Computational and biochemical studies validate both ligand interactions. Our functional analysis identified cholesterol as an orthosteric agonist and the bitter tastant cmpd28.1 as a positive allosteric modulator with direct agonist activity at TAS2R14. Moreover, the orthosteric pocket is connected to the allosteric site via an elongated cavity, which has a hydrophobic core rich in aromatic residues. Our findings provide insights into the ligand recognition of bitter taste receptors and suggest activities of TAS2R14 beyond bitter taste perception via intracellular allosteric tastants.


Assuntos
Colesterol , Espaço Intracelular , Receptores Acoplados a Proteínas G , Paladar , Humanos , Regulação Alostérica/efeitos dos fármacos , Sítio Alostérico , Colesterol/química , Colesterol/metabolismo , Colesterol/farmacologia , Microscopia Crioeletrônica , Interações Hidrofóbicas e Hidrofílicas , Espaço Intracelular/química , Espaço Intracelular/metabolismo , Ligantes , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/ultraestrutura , Reprodutibilidade dos Testes , Paladar/efeitos dos fármacos , Paladar/fisiologia , Transducina/química , Transducina/metabolismo , Transducina/ultraestrutura
17.
BMJ Open Qual ; 13(Suppl 1)2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38626941

RESUMO

OBJECTIVE: Our aim was to refine the essential newborn care practices by employing the multidisciplinary peer team-led quality improvement (QI) projects. DESIGN: In 2017, concerning the same, the department focused on early initiation of breast feeding, prevention of hypothermia within an hour of life and rational usage of antibiotics among babies admitted to neonatal intensive care unit (NICU). Baseline data reported the rate of initiation of breast feeding, hypothermia and antibiotic exposure rate as 35%, 78% and 75%, respectively. Root causes were analysed and a series of Plan-Do-Study-Act cycles were conducted to test the changes. The process of change was studied through run charts (whereas control charts were used for study purpose). RESULT: After the implementation of the QI projects, the rate of initiation of breast feeding was found to be improved from 35% to 90%, the incidence of hypothermia got reduced from 78% to 10% and the antibiotic exposure rate declined from 75% to 20%. Along with the improvement in indicators related to essential newborn care, down the stream we found a decrease in the percentage of culture-positive sepsis rate in the NICU. CONCLUSION: Peer team-led QI initiatives in a resource-limited setting proved beneficial in improving essential newborn care practices.


Assuntos
Hipotermia , Melhoria de Qualidade , Recém-Nascido , Lactente , Feminino , Humanos , Hipotermia/prevenção & controle , Hospitais de Ensino , Índia , Antibacterianos/uso terapêutico , Hospitais Públicos
18.
bioRxiv ; 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38659786

RESUMO

The dopamine D1 receptor (D1R) has fundamental roles in voluntary movement and memory and is a validated drug target for neurodegenerative and neuropsychiatric disorders. However, previously developed D1R selective agonists possess a catechol moiety which displays poor pharmacokinetic properties. The first selective non-catechol D1R agonists were recently discovered and unexpectedly many of these ligands showed G protein biased signaling. Here, we investigate both catechol and non-catechol D1R agonists to validate potential biased signaling and examine if this impacts agonist-induced D1R endocytosis. We determined that most, but not all, non-catechol agonists display G protein biased signaling at the D1R and have reduced or absent Beta-arrestin recruitment. A notable exception was compound (Cmpd) 19, a non-catechol agonist with full efficacy at both D1R-G protein or D1R Beta-arrestin pathways. In addition, the catechol ligand A-77636 was a highly potent, super agonist for D1R Beta-arrestin activity. When examined for agonist-induced D1R endocytosis, balanced agonists SKF-81297 and Cmpd 19 induced robust D1R endocytosis while the G protein biased agonists did not. The Beta-arrestin super agonist, A-77636, showed significantly increased D1R endocytosis. Moreover, Beta-arrestin recruitment efficacy of tested agonists strongly correlated with total D1R endocytosis. Taken together, these results indicate the degree of D1R signaling functional selectivity profoundly impacts D1R endocytosis regardless of pharmacophore. The range of functional selectivity of these D1R agonists will provide valuable tools to further investigate D1R signaling, trafficking and therapeutic potential.

19.
J Asthma ; 61(10): 1181-1189, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38488853

RESUMO

INTRODUCTION: Once-daily inhalers have been shown to improve adherence leading to lesser discontinuation compared to twice- or thrice-daily inhalers in management of asthma. Combination of Vilanterol and Fluticasone Furoate (VI/FF) is approved for management of asthma and COPD and is available as a dry powder inhaler. Pressurized-Metered Dose Inhalers (pMDIs) offer ease-of-use and therapy alternatives for patients with low inspiratory flow. This study assessed the efficacy and safety of a new once-daily pMDI containing VI/FF in individuals diagnosed with persistent asthma. METHODS: This phase 3, double-blind, randomized controlled study assessed the non-inferiority of VI/FF (12.5 mcg/50 mcg & 12.5 mcg/100 mcg; 2 puffs once-daily) over Formoterol Fumarate and Fluticasone Propionate (FOR/FP, 6 mcg/125 mcg & 6 mcg/250 mcg; 2 puffs twice-daily) in patients with persistent asthma. Primary outcome was change from baseline in trough FEV1 at the end of study (12 weeks). Adverse events and number of exacerbations were used to evaluate safety. RESULTS: A total of 330 patients were randomized into VI/FF (165) and FOR/FP (165). Trough FEV1 significantly improved in both the groups at week 12, with a mean difference (VI/FF minus FOR/FP) being 54.75 mL (95% CI, 8.42-101.08 mL, p = 0.02). The low dose VI/FF had similar efficacy to that of low dose FOR/FP and high dose VI/FF had similar efficacy to high dose FOR/FP. No serious adverse events were reported during the study. CONCLUSION: Once daily VI/FF pMDI was non-inferior to twice daily FOR/FP pMDI in patients with persistent asthma.


Assuntos
Androstadienos , Asma , Álcoois Benzílicos , Clorobenzenos , Combinação de Medicamentos , Humanos , Asma/tratamento farmacológico , Álcoois Benzílicos/administração & dosagem , Álcoois Benzílicos/efeitos adversos , Álcoois Benzílicos/uso terapêutico , Masculino , Feminino , Método Duplo-Cego , Pessoa de Meia-Idade , Clorobenzenos/administração & dosagem , Clorobenzenos/efeitos adversos , Clorobenzenos/uso terapêutico , Adulto , Androstadienos/administração & dosagem , Androstadienos/efeitos adversos , Androstadienos/uso terapêutico , Administração por Inalação , Broncodilatadores/administração & dosagem , Broncodilatadores/efeitos adversos , Broncodilatadores/uso terapêutico , Inaladores Dosimetrados , Idoso , Volume Expiratório Forçado/efeitos dos fármacos , Resultado do Tratamento , Adulto Jovem , Esquema de Medicação
20.
Nat Commun ; 15(1): 2335, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38485946

RESUMO

This paper presents our findings on the recursive band gap engineering of chiral fermions in bilayer graphene doubly aligned with hBN. Using two interfering moiré potentials, we generate a supermoiré pattern that renormalizes the electronic bands of the pristine bilayer graphene, resulting in higher order fractal gaps even at very low energies. These Bragg gaps can be mapped using a unique linear combination of periodic areas within the system. To validate our findings, we use electronic transport measurements to identify the position of these gaps as a function of the carrier density. We establish their agreement with the predicted carrier densities and corresponding quantum numbers obtained using the continuum model. Our study provides strong evidence of the quantization of the momentum-space area of quasi-Brillouin zones in a minimally incommensurate lattice. It fills important gaps in the understanding of band structure engineering of Dirac fermions with a doubly periodic superlattice spinor potential.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...