Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.182
Filtrar
1.
Ophthalmol Glaucoma ; 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-39004222

RESUMO

PURPOSE: To compare safety, effectiveness and baseline predictors of failure in standalone primary Xen45 gel stent (Xen) vs trabeculectomy (Trab) in glaucoma. DESIGN: Retrospective study SUBJECTS: Subjects that underwent primary Xen or Trab augmented by mitomycin-C with at least 12 months follow-up. METHODS: Multinational observational study of eyes in the Fight Glaucoma Blindness international registry MAIN OUTCOME MEASURES: The primary outcome was success at 12 months defined by IOP reduction ≥ 20% from baseline and ≤ threshold IOPs of 15mmHg, 18mmHg and 21mmHg with (qualified) or without (complete) medications and without secondary glaucoma surgery. Multivariable mixed effects cox regression models were used to identify risk factors for failure in each cohort. RESULTS: 701 eyes (Xen, 308; Trab, 393) of 596 subjects were included with baseline IOP being significantly higher (22.4 vs 19.9 mmHg, p < 0.001) and baseline medications significantly lower in the Xen vs the Trab group (2.9 vs 3.4, p <0.001). Baseline visual field (VF) mean deviation (MD) was less severe in the Xen group (-9.47 vs -13.04 dB, p < 0.001). The proportion of complete surgical success was significantly lower in the Xen vs Trab group across the three upper IOP limits at 12 months; 32% vs 52% at 15mmHg, 37% vs 54% at 18mmHg, and 39% vs 55% at 21mmHg (p < 0.001). The incidence of post-operative numerical and symptomatic hypotony was lower in the Xen vs Trab group. In the Xen cohort, a higher failure rate was associated with Asian ethnicity (HR, 1.97; 95% CI, 1.03-3.79) and use of oral acetazolamide at baseline (HR, 1.74; 1.13-2.70), while a lower failure rate was associated with diagnosis of ocular hypertension/open angle glaucoma suspect (HR, 0.52; 0.28-0.94) and secondary open angle glaucoma (HR, 0.45; 0.25-0.8). Exposure to prostaglandin analogue was associated with greater failure in the Trab group (HR, 2.66; 1.18-6.01). CONCLUSIONS: There was significantly greater complete success at 12 months across all complete success definitions for Trab compared to Xen, while the rate of post-operative hypotony was significantly lower in Xen group. Asian ethnicity and use of oral acetazolamide at baseline were associated with greater failure in Xen, while exposure to prostaglandin analogue was associated with greater failure in Trab patients. Such baseline predictors of success and failure may help guide patient selection for subconjunctival minimally invasive glaucoma surgery in patients undergoing surgical intervention.

2.
Org Lett ; 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38968424

RESUMO

The peptide sex-inducing pheromone SIP+ (1) bearing an unusual sulfated aspartic acid residue induces sexual reproduction in diatom populations. Herein, we report the first total synthesis of SIP+ using both a sulfated building block approach and a solid-phase peptide synthesis (SPPS)-compatible late-stage sulfation strategy to assemble the natural product. The modular approaches provide concise routes to useful quantities of the natural product for future structure activity relationship studies examining the role of SIP+ in diatom biology.

3.
Artigo em Inglês | MEDLINE | ID: mdl-38851398

RESUMO

Mast cell activation syndrome (MCAS) is a term applied to several clinical entities which have gained increased attention from patients and medical providers. While several descriptive publications about MCAS exist, there are many gaps in knowledge resulting in confusion about this clinical syndrome. Whether MCAS is a primary syndrome or exists as a constellation of symptoms in the context of known inflammatory, allergic, or clonal disorders associated with systemic mast cell (MC) activation is not well understood. More importantly, the underlying mechanisms and pathways that lead to MC activation in MCAS patients remain to be elucidated. The purpose of this manuscript is to summarize the known literature, identify gaps in knowledge, and highlight research needs. Several topics are covered: 1) Contextualization of MCAS and MCAS-like endotypes and related diagnostic evaluations; 2) Mechanistic research; 3) Management of typical and refractory symptoms, and 4) MCAS-specific education for patients and healthcare providers.

4.
RSC Chem Biol ; 5(6): 567-571, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38846076

RESUMO

Cyclotides are a diverse class of plant-derived cyclic, disulfide-rich peptides with a unique cyclic cystine knot topology. Their remarkable structural stability and resistance to proteolytic degradation can lead to improved pharmacokinetics and oral activity as well as selectivity and high enzymatic stability. Thus, cyclotides have emerged as powerful scaffold molecules for designing peptide-based therapeutics. The chemical engineering of cyclotides has generated novel peptide ligands of G protein-coupled receptors (GPCRs), today's most exploited drug targets. However key challenges potentially limit the widespread use of cyclotides in molecular grafting applications. Folding of cyclotides containing bioactive epitopes remains a major bottleneck in cyclotide synthesis. Here we present a modular 'plug and play' approach that effectively bypasses problems associated with the oxidative folding of cyclotides. By grafting onto a pre-formed acyclic cyclotide-like scaffold we show that difficult-to-graft sequences can be easily obtained and can target GPCRs with nanomolar affinities and potencies. We further show the suitability of this new method to graft other complex epitopes including structures with additional disulfide bonds that are not readily available via currently employed chemical methods, thus fully unlocking cyclotides to be used in drug design applications.

5.
Front Cell Infect Microbiol ; 14: 1346821, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38694515

RESUMO

Background: Microbial keratitis is one of the leading causes of blindness globally. An overactive immune response during an infection can exacerbate damage, causing corneal opacities and vision loss. This study aimed to identify the differentially expressed genes between corneal infection patients and healthy volunteers within the cornea and conjunctiva and elucidate the contributing pathways to these conditions' pathogenesis. Moreover, it compared the corneal and conjunctival transcriptomes in corneal-infected patients to cytokine levels in tears. Methods: Corneal and conjunctival swabs were collected from seven corneal infection patients and three healthy controls under topical anesthesia. RNA from seven corneal infection patients and three healthy volunteers were analyzed by RNA sequencing (RNA-Seq). Tear proteins were extracted from Schirmer strips via acetone precipitation from 38 cases of corneal infection and 14 healthy controls. The cytokines and chemokines IL-1ß, IL-6, CXCL8 (IL-8), CX3CL1, IL-10, IL-12 (p70), IL-17A, and IL-23 were measured using an antibody bead assay. Results: A total of 512 genes were found to be differentially expressed in infected corneas compared to healthy corneas, with 508 being upregulated and four downregulated (fold-change (FC) <-2 or > 2 and adjusted p <0.01). For the conjunctiva, 477 were upregulated, and 3 were downregulated (FC <-3 or ≥ 3 and adjusted p <0.01). There was a significant overlap in cornea and conjunctiva gene expression in patients with corneal infections. The genes were predominantly associated with immune response, regulation of angiogenesis, and apoptotic signaling pathways. The most highly upregulated gene was CXCL8 (which codes for IL-8 protein). In patients with corneal infections, the concentration of IL-8 protein in tears was relatively higher in patients compared to healthy controls but did not show statistical significance. Conclusions: During corneal infection, many genes were upregulated, with most of them being associated with immune response, regulation of angiogenesis, and apoptotic signaling. The findings may facilitate the development of treatments for corneal infections that can dampen specific aspects of the immune response to reduce scarring and preserve sight.


Assuntos
Túnica Conjuntiva , Córnea , Citocinas , Ceratite , Lágrimas , Transcriptoma , Humanos , Lágrimas/metabolismo , Citocinas/metabolismo , Citocinas/genética , Córnea/metabolismo , Córnea/imunologia , Feminino , Masculino , Pessoa de Meia-Idade , Adulto , Túnica Conjuntiva/metabolismo , Túnica Conjuntiva/imunologia , Ceratite/genética , Ceratite/imunologia , Ceratite/metabolismo , Idoso , Perfilação da Expressão Gênica
6.
Digit Discov ; 3(5): 977-986, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38756224

RESUMO

Deep learning can create accurate predictive models by exploiting existing large-scale experimental data, and guide the design of molecules. However, a major barrier is the requirement of both positive and negative examples in the classical supervised learning frameworks. Notably, most peptide databases come with missing information and low number of observations on negative examples, as such sequences are hard to obtain using high-throughput screening methods. To address this challenge, we solely exploit the limited known positive examples in a semi-supervised setting, and discover peptide sequences that are likely to map to certain antimicrobial properties via positive-unlabeled learning (PU). In particular, we use the two learning strategies of adapting base classifier and reliable negative identification to build deep learning models for inferring solubility, hemolysis, binding against SHP-2, and non-fouling activity of peptides, given their sequence. We evaluate the predictive performance of our PU learning method and show that by only using the positive data, it can achieve competitive performance when compared with the classical positive-negative (PN) classification approach, where there is access to both positive and negative examples.

7.
Digit Discov ; 3(5): 1069-1070, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38756226

RESUMO

[This corrects the article DOI: 10.1039/D3DD00217A.].

8.
Artigo em Inglês | MEDLINE | ID: mdl-38816017

RESUMO

BACKGROUND: Hereditary hemorrhagic telangiectasia is an autosomal dominant vascular dysplasia characterized by mucocutaneous telangiectasias, recurrent epistaxis, and organ vascular malformations including in the brain, which occur in about 10% of patients. These brain vascular malformations include high-flow AVMs and AVFs as well as low-flow capillary malformations. High-flow lesions can rupture, causing neurologic morbidity and mortality. STATE OF PRACTICE: International guidelines for the diagnosis and management of hereditary hemorrhagic telangiectasia recommend screening children for brain vascular malformations with contrast enhanced MR imaging at hereditary hemorrhagic telangiectasia diagnosis. Screening has not been uniformly adopted by some practitioners who contend that screening is not justified. Arguments against screening include application of short-term data from the adult A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA) trial of unruptured sporadic brain AVMs to children with hereditary hemorrhagic telangiectasia as well as concerns about administration of sedation or IV contrast and causing patients or families increased anxiety. ANALYSIS: In this article, a multidisciplinary group of experts on hereditary hemorrhagic telangiectasia reviewed data that support screening guidelines and counter arguments against screening. Children with hereditary hemorrhagic telangiectasia have a preponderance of high-flow lesions including AVFs, which have the highest rupture risk. The rupture risk among children is estimated at about 0.7% per lesion per year and is additive across lesions and during a lifetime. ARUBA, an adult clinical trial of expectant medical management versus treatment of unruptured brain AVMs, favored medical management at 5 years but is not applicable to pediatric patients with hereditary hemorrhagic telangiectasia given the life expectancy of a child. Additionally, interventional, radiosurgical, and surgical techniques have improved with time. Experienced neurovascular experts can prospectively determine the best treatment for each child on the basis of local resources. The "watch and wait" approach to imaging means that children with brain vascular malformations will not be identified until a potentially life-threatening and deficit-producing intracerebral hemorrhage occurs. This expert group does not deem this to be an acceptable trade-off.

9.
Br J Ophthalmol ; 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38789132

RESUMO

OBJECTIVE: To evaluate efficacy and safety outcomes of the Xen 45 gel stent implant over 24 months of follow-up. METHODS: A retrospective analysis of prospectively collected data from the Fight Glaucoma Blindness observational registry. Complete success (CS) was defined as intraocular pressure (IOP) reduction ≥20% from preoperative and an IOP ≤18 mm Hg and ≥6 mm Hg with no secondary procedure at 2 years and without IOP-lowering medications. Qualified success (QS) was defined similarly, allowing the use of IOP-lowering medications. RESULTS: The Xen 45 gel stent implant was implanted in 646 eyes of 515 patients. Preoperative IOP was 21.4±7.6 (mean±SD) mm Hg on 2.7±1.3 IOP-lowering medication and mean deviation was -10.2±8.4 dB. After 24-month follow-up, IOP was 16.8±7.3 mm Hg (mean reduction of 21.7%) on 1.2±1.4 IOP-lowering medications. CS and QS rates at 24 months were 26% and 48%, respectively. CS and QS were higher in the Xen stand-alone group (33% and 52%, respectively) than in the Xen+cataract group (16% and 42%, respectively). Bleb needling was performed in 28.4% of cases, and 18% underwent a secondary procedure. CONCLUSIONS: The Xen 45 gel stent implant offers acceptable long-term efficacy for the treatment of open-angle glaucoma. However, there is a significant rate of reoperation and needling, and outcomes are less effective if combined with cataract surgery.

10.
Nat Mach Intell ; 6(5): 525-535, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38799228

RESUMO

Large language models (LLMs) have shown strong performance in tasks across domains but struggle with chemistry-related problems. These models also lack access to external knowledge sources, limiting their usefulness in scientific applications. We introduce ChemCrow, an LLM chemistry agent designed to accomplish tasks across organic synthesis, drug discovery and materials design. By integrating 18 expert-designed tools and using GPT-4 as the LLM, ChemCrow augments the LLM performance in chemistry, and new capabilities emerge. Our agent autonomously planned and executed the syntheses of an insect repellent and three organocatalysts and guided the discovery of a novel chromophore. Our evaluation, including both LLM and expert assessments, demonstrates ChemCrow's effectiveness in automating a diverse set of chemical tasks. Our work not only aids expert chemists and lowers barriers for non-experts but also fosters scientific advancement by bridging the gap between experimental and computational chemistry.

11.
Front Immunol ; 15: 1387454, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38799468

RESUMO

Introduction: Mycobacteria are known to exert a range of heterologous effects on the immune system. The mycobacteria-based Freund's Complete Adjuvant is a potent non-specific stimulator of the immune response used in immunization protocols promoting antibody production, and Mycobacterium bovis Bacille Calmette Guérin (BCG) vaccination has been linked with decreased morbidity and mortality beyond the specific protection it provides against tuberculosis (TB) in some populations and age groups. The role of heterologous antibodies in this phenomenon, if any, remains unclear and under-studied. Methods: We set out to evaluate antibody responses to a range of unrelated pathogens following infection with Mycobacterium tuberculosis (M.tb) and vaccination with BCG or a candidate TB vaccine, MTBVAC, in non-human primates. Results: We demonstrate a significant increase in the titer of antibodies against SARS-CoV-2, cytomegalovirus, Epstein-Barr virus, tetanus toxoid, and respiratory syncytial virus antigens following low-dose aerosol infection with M.tb. The magnitude of some of these responses correlated with TB disease severity. However, vaccination with BCG administered by the intradermal, intravenous or aerosol routes, or intradermal delivery of MTBVAC, did not increase antibody responses against unrelated pathogens. Discussion: Our findings suggest that it is unlikely that heterologous antibodies contribute to the non-specific effects of these vaccines. The apparent dysregulation of B cell responses associated with TB disease warrants further investigation, with potential implications for risk of B cell cancers and novel therapeutic strategies.


Assuntos
Vacina BCG , Mycobacterium tuberculosis , Tuberculose , Vacinação , Animais , Vacina BCG/imunologia , Vacina BCG/administração & dosagem , Tuberculose/imunologia , Tuberculose/prevenção & controle , Mycobacterium tuberculosis/imunologia , Anticorpos Antibacterianos/imunologia , Anticorpos Antibacterianos/sangue , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/sangue , Vacinas contra a Tuberculose/imunologia , Vacinas contra a Tuberculose/administração & dosagem , Feminino , Macaca mulatta , SARS-CoV-2/imunologia , COVID-19/imunologia , COVID-19/prevenção & controle , Imunidade Heteróloga , Masculino
12.
J Am Chem Soc ; 146(19): 13391-13398, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38691098

RESUMO

Inverted p-i-n perovskite solar cells (PSCs) are easy to process but need improved interface characteristics with reduced energy loss to prevent efficiency drops when increasing the active photovoltaic area. Here, we report a series of poly ferrocenyl molecules that can modulate the perovskite surface enabling the construction of small- and large-area PSCs. We found that the perovskite-ferrocenyl interaction forms a hybrid complex with enhanced surface coordination strength and activated electronic states, leading to lower interfacial nonradiative recombination and charge transport resistance losses. The resulting PSCs achieve an enhanced efficiency of up to 26.08% for small-area devices and 24.51% for large-area devices (1.0208 cm2). Moreover, the large-area PSCs maintain >92% of the initial efficiency after 2000 h of continuous operation at the maximum power point under 1-sun illumination and 65 °C.

13.
Res Sq ; 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38746473

RESUMO

Oral tumors are relatively common in dogs, and canine oral squamous cell carcinoma (COSCC) is the most prevalent oral malignancy of epithelial origin. COSCC is locally aggressive with up to 20% of patients showing regional or distant metastasis at the time of diagnosis. The treatment of choice most typically involves wide surgical excision. Although long-term remission is possible, treatments are associated with significant morbidity and can negatively impact functionality and quality of life. OSCCs have significant upregulation of the RAS-RAF-MEK-MAPK signaling axis, and we had previously hypothesized that small-molecule inhibitors that target RAS signaling might effectively inhibit tumor growth and progression. Here, we demonstrate that the MEK inhibitor trametinib, an FDA-approved drug for human cancers, significantly blocks the growth of several COSCC cell lines established from current patient tumor samples. We further show clinical evidence that the drug is able to cause significant tumor regression in some patients with spontaneously occurring COSCC. Given the limited treatment options available and the high rate of owner rejection of these offered options, these findings provide new hope that more acceptable treatment options may soon enter the veterinary clinic.

14.
NPJ Parkinsons Dis ; 10(1): 107, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38773105

RESUMO

Alpha-synuclein (αS)-rich Lewy bodies and neurites in the cerebral cortex correlate with the presence of dementia in Parkinson disease (PD) and Dementia with Lewy bodies (DLB), but whether αS influences synaptic vesicle dynamics in human cortical neurons is unknown. Using a new iPSC-based assay platform for measuring synaptic vesicle cycling, we found that in human cortical glutamatergic neurons, increased αS from either transgenic expression or triplication of the endogenous locus in patient-derived neurons reduced synaptic vesicle cycling under both stimulated and spontaneous conditions. Thus, using a robust, easily adopted assay platform, we show for the first time αS-induced synaptic dysfunction in human cortical neurons, a key cellular substrate for PD dementia and DLB.

16.
Pigment Cell Melanoma Res ; 37(4): 480-495, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38613320

RESUMO

Melanocyte stem cells (McSCs) of the hair follicle are a rare cell population within the skin and are notably underrepresented in whole-skin, single-cell RNA sequencing (scRNA-seq) datasets. Using a cell enrichment strategy to isolate KIT+/CD45- cells from the telogen skin of adult female C57BL/6J mice, we evaluated the transcriptional landscape of quiescent McSCs (qMcSCs) at high resolution. Through this evaluation, we confirmed existing molecular signatures for qMcCS subpopulations (e.g., Kit+, Cd34+/-, Plp1+, Cd274+/-, Thy1+, Cdh3+/-) and identified novel qMcSC subpopulations, including two that differentially regulate their immune privilege status. Within qMcSC subpopulations, we also predicted melanocyte differentiation potential, neural crest potential, and quiescence depth. Taken together, the results demonstrate that the qMcSC population is heterogeneous and future studies focused on investigating changes in qMcSCs should consider changes in subpopulation composition.


Assuntos
Melanócitos , Camundongos Endogâmicos C57BL , Análise de Sequência de RNA , Análise de Célula Única , Células-Tronco , Animais , Melanócitos/metabolismo , Melanócitos/citologia , Células-Tronco/metabolismo , Células-Tronco/citologia , Feminino , Camundongos , Diferenciação Celular , Folículo Piloso/citologia , Folículo Piloso/metabolismo , Heterogeneidade Genética
17.
Neurosurgery ; 95(1): 179-185, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38634693

RESUMO

BACKGROUND AND OBJECTIVES: Dual antiplatelet therapy (DAPT) is necessary to minimize the risk of periprocedural thromboembolic complications associated with aneurysm embolization using pipeline embolization device (PED). We aimed to assess the impact of platelet function testing (PFT) on reducing periprocedural thromboembolic complications associated with PED flow diversion in patients receiving aspirin and clopidogrel. METHODS: Patients with unruptured intracranial aneurysms requiring PED flow diversion were identified from 13 centers for retrospective evaluation. Clinical variables including the results of PFT before treatment, periprocedural DAPT regimen, and intracranial complications occurring within 72 h of embolization were identified. Complication rates were compared between PFT and non-PFT groups. Differences between groups were tested for statistical significance using the Wilcoxon rank sum, Fisher exact, or χ 2 tests. A P -value <.05 was statistically significant. RESULTS: 580 patients underwent PED embolization with 262 patients dichotomized to the PFT group and 318 patients to the non-PFT group. 13.7% of PFT group patients were clopidogrel nonresponders requiring changes in their pre-embolization DAPT regimen. Five percentage of PFT group [2.8%, 8.5%] patients experienced thromboembolic complications vs 1.6% of patients in the non-PFT group [0.6%, 3.8%] ( P = .019). Two (15.4%) PFT group patients with thromboembolic complications experienced permanent neurological disability vs 4 (80%) non-PFT group patients. 3.7% of PFT group patients [1.5%, 8.2%] and 3.5% [1.8%, 6.3%] of non-PFT group patients experienced hemorrhagic intracranial complications ( P > .9). CONCLUSION: Preprocedural PFT before PED treatment of intracranial aneurysms in patients premedicated with an aspirin and clopidogrel DAPT regimen may not be necessary to significantly reduce the risk of procedure-related intracranial complications.


Assuntos
Clopidogrel , Embolização Terapêutica , Aneurisma Intracraniano , Inibidores da Agregação Plaquetária , Testes de Função Plaquetária , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Embolização Terapêutica/métodos , Aneurisma Intracraniano/cirurgia , Inibidores da Agregação Plaquetária/administração & dosagem , Inibidores da Agregação Plaquetária/efeitos adversos , Inibidores da Agregação Plaquetária/uso terapêutico , Estudos Retrospectivos , Idoso , Clopidogrel/administração & dosagem , Clopidogrel/uso terapêutico , Tromboembolia/prevenção & controle , Tromboembolia/etiologia , Tromboembolia/epidemiologia , Aspirina/administração & dosagem , Aspirina/uso terapêutico , Complicações Pós-Operatórias/prevenção & controle , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Adulto
19.
Appl Radiat Isot ; 208: 111307, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38564840

RESUMO

Early works that used thermoluminescent dosimeters (TLDs) to measure absorbed dose from alpha particles reported relatively high variation (10%) between TLDs, which is undesirable for modern dosimetry applications. This work outlines a method to increase precision for absorbed dose measured using TLDs with alpha-emitting radionuclides by applying an alpha-specific chip factor (CF) that individually characterizes the TLD sensitivity to alpha particles. Variation between TLDs was reduced from 21.8% to 6.7% for the standard TLD chips and 7.9% to 3.3% for the thin TLD chips. It has been demonstrated by this work that TLD-100 can be calibrated to precisely measure the absorbed dose to water from alpha-emitting radionuclides.


Assuntos
Dosímetros de Radiação , Dosimetria Termoluminescente , Dosimetria Termoluminescente/métodos , Radioisótopos , Radiometria/métodos , Calibragem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...