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1.
bioRxiv ; 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38559052

RESUMO

In-space manufacturing of nanomaterials is a promising concept while having limited successful examples. DNA-inspired Janus base nanomaterials (JBNs), used for therapeutics delivery and tissue regeneration, are fabricated via a controlled self-assembly process in water at ambient temperature, making them highly suitable for in-space manufacturing. For the first time, we designed and accomplished the production of JBNs on orbit during the Axiom-2 (Ax-2) mission demonstrating great promising and benefits of in-space manufacturing of nanomaterials.

2.
J Environ Manage ; 356: 120581, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38518495

RESUMO

Prescribed burning can be an effective land management tool. Here, we study changes in plant diversity and composition following experimental fire disturbance in microcosm units extracted from a twenty-five-year-old historically reclaimed grassland located at Highland Valley Copper mine in British Columbia (B.C.), Canada. Experimental microcosm units were dominated by agronomic grass species Elymus lanceolatus, Thinopyrum intermedium and Bromus inermis. The disturbance treatment was fire intensity, represented by three levels (light, moderate, and heavy), replicated six times per treatment. Fire intensity was controlled by modifying the weight of dried litter applied to each microcosm unit (50 g,150 g, 200g), along with the time each grass turf was burned (10 s, 15 s, 20 s). One day after the fire treatment was applied, microcosm units were seeded with a native species mix consisting of six grassland species common to southern B.C. to examine effectiveness of plant establishment postburn. Disturbance treatments resulted in higher overall alpha diversity, richness, evenness, and beta diversity. Plant community changes included colonization of seeded native forbs, grasses, and legumes in response to disturbance. Aboveground net primary productivity (ANPP) was net neutral within the light and moderate burning disturbance treatments but resulted in increased ANPP with heavy disturbance. Litter mass reduced plant diversity and ANPP, indicating that litter was a major factor in plant community dynamics. These results suggest disturbance by burning leads to short term positive plant community response towards increasing diversity of semi-arid grasslands, and aids in shifting plant communities to higher diversity composed of an increase in native plant species. Our results also suggest that without active management the gains observed in native species establishment might quickly be out shadowed and restricted by the previously dominant agronomic plant community.


Assuntos
Pradaria , Poaceae , Plantas , Agricultura , Colúmbia Britânica , Ecossistema
3.
J Endocr Soc ; 8(5): bvae027, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38487212

RESUMO

Context: Metabolic surgery remains the most effective and durable treatment for severe obesity and related metabolic diseases. Objective: We examined cardiometabolic improvements after metabolic surgery and associated presurgery demographic and clinical factors in a large multiracial cohort. Methods: Included were 7804 patients (20-79 years) undergoing first-time metabolic surgery at Vanderbilt University Medical Center from 1999 to 2022. Pre- and 1-year postsurgery cardiometabolic profiles were extracted from medical records, including body mass index (BMI), blood pressure, blood lipids, glucose, and hemoglobin A1c. The 10-year atherosclerotic cardiovascular disease (ASCVD) risk was estimated per American College of Cardiology/American Heart Association equations. Pre- to postsurgery cardiometabolic profiles were compared by paired t-test, and associated factors were identified by multivariable linear and logistic regression. Results: Among 7804 patients, most were women and White, while 1618 were men and 1271 were Black; median age and BMI were 45 years [interquartile range (IQR): 37-53] and 46.4 kg/m2 (IQR: 42.1-52.4). At 1-year postsurgery, patients showed significant decreases in systolic blood pressure (10.5 [95% confidence interval: 10.1, 10.9] mmHg), total cholesterol (13.5 [10.3, 16.7] mg/dL), glucose (13.6 [12.9, 14.4] mg/dL), hemoglobin A1c (1.13% [1.06, 1.20]), and 10-year ASCVD risk (absolute reduction: 1.58% [1.22, 1.94]; relative reduction: 34.4% [29.4, 39.3]); all P < .0001. Older, male, or Black patients showed less reduction in 10-year ASCVD risk and lower odds of diabetes/hypertension/dyslipidemia remission than younger, female, or White patients. Patients with a history of diabetes, hypertension, dyslipidemia, or cardiovascular disease showed less cardiometabolic improvements than those without. Results were similar with or without further adjusting for weight loss and largely sustained at 2-year postsurgery. Conclusion: Metabolic surgery results in significant cardiometabolic improvements, particularly among younger, female, or White patients and those without comorbidities.

4.
medRxiv ; 2024 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-38293039

RESUMO

Background: Bariatric surgery is an effective intervention for obesity, but it requires comprehensive postoperative self-management to achieve optimal outcomes. While patient portals are generally seen as beneficial in engaging patients in health management, the link between their use and post-bariatric surgery weight loss remains unclear. Objective: This study investigated the association between patient portal engagement and postoperative body mass index (BMI) reduction among bariatric surgery patients. Methods: This retrospective longitudinal study included patients who underwent Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) at Vanderbilt University Medical Center (VUMC) between January 2018 and March 2021. Using generalized estimating equations, we estimated the association between active days of postoperative patient portal use and the reduction of BMI percentage (%BMI) at 3, 6, and 12 months post-surgery. Covariates included duration since surgery, the patient's age at the time of surgery, gender, race and ethnicity, type of bariatric surgery, severity of comorbid conditions, and socioeconomic disadvantage. Results: The study included 1,415 patients, mostly female (80.9%), with diverse racial and ethnic backgrounds. 805 (56.9%) patients underwent RYGB and 610 (43.1%) underwent SG. By one-year post-surgery, the mean (SD) %BMI reduction was 31.1% (8.3%), and the mean (SD) number of patient portal active days was 61.0 (41.2). A significantly positive association was observed between patient portal engagement and %BMI reduction, with variations revealed over time. Each 10-day increment of active portal use was associated with a 0.57% ([95% CI: 0.42- 0.72], P < .001) and 0.35% ([95% CI: 0.22- 0.49], P < .001) %BMI reduction at 3 and 6 months postoperatively. The association was not statistically significant at 12 months postoperatively (ß=-0.07, [95% CI: -0.24- 0.09], P = .54). Various portal functions, including messaging, visits, my record, medical tools, billing, resources, and others, were positively associated with %BMI reduction at 3- and 6-months follow-ups. Conclusions: Greater patient portal engagement, which may represent stronger adherence to postoperative instructions, better self-management of health, and enhanced communication with care teams, was associated with improved postoperative weight loss. Future investigations are needed to identify important portal features that contribute to the long-term success of weight loss management.

5.
Am Surg ; 90(4): 810-818, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37927010

RESUMO

BACKGROUND: Perforated marginal ulcers (PMUs) are a rare but known complication of bariatric surgery. Management typically involves prompt surgical intervention, but limited data exists on non-operative approaches. This study reviews published data on non-operative management of PMUs and presents a case series of patients who were managed non-operatively. Our hypothesis is that certain patients with signs of perforation can be successfully managed non-operatively with close observation. METHODS: We completed a systematic review searching PubMed, Embase, Web of Science, Cochrane, and clinicaltrials.gov. Ultimately 3 studies described the presentation and non-operative management of 5 patients. Additionally, we prospectively collected data from our institution on all patients who presented between Dec. 2022 and Dec. 2023 with PMUs confirmed on imaging and managed non-operatively. RESULTS: In our literature review, three patients had Roux-en-Y gastric bypass (RYGB), while two had one anastomosis gastric bypass. One patient required surgery two days after admission. Another underwent elective conversion surgery weeks later for a non-healing ulcer. Two received endoscopic interventions. One patient recovered with nil-per-os (NPO) status, and intravenous proton pump inhibitor (PPI) treatment. The patients in our case series presented with normal vital signs, an average of 30 months after RYGB, and with CT scan signs of perforation. None of these patients required surgical or endoscopic intervention. CONCLUSION: In conclusion, while perforated marginal ulcers have traditionally been considered a surgical emergency, some patients can be successfully treated with non-operative management. More research is needed to identify the clinical presentation features, comorbidities, and imaging findings of this group.


Assuntos
Derivação Gástrica , Úlcera Péptica , Humanos , Úlcera , Pesquisa , Administração Intravenosa , Derivação Gástrica/efeitos adversos
6.
Exp Neurol ; 371: 114572, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37852467

RESUMO

Cuprizone (CPZ)-induced alterations in axonal myelination are associated with a period of neuronal hyperexcitability and increased activity of hyperpolarization-activated and cyclic nucleotide-gated (HCN) channels in the thalamocortical (TC) system. Substances used for the treatment of multiple sclerosis (MS) have been shown to normalize neuronal excitability in CPZ-treated mice. Therefore, we aimed to examine the effects of diroximel fumarate (DRF) and the sphingosine 1-phospate receptor (S1PR) modulator siponimod on action potential firing and the inward current (Ih) carried by HCN ion channels in naive conditions and during different stages of de- and remyelination. Here, DRF application reduced Ih current density in ex vivo patch clamp recordings from TC neurons of the ventrobasal thalamic complex (VB), thereby counteracting the increase of Ih during early remyelination. Siponimod reduced Ih in VB neurons under control conditions but had no effect in neurons of the auditory cortex (AU). Furthermore, siponimod increased and decreased AP firing properties of neurons in VB and AU, respectively. Computational modeling revealed that both DRF and siponimod influenced thalamic bursting during early remyelination by delaying the onset and decreasing the interburst frequency. Thus, substances used in MS treatment normalize excitability in the TC system by influencing AP firing and Ih.


Assuntos
Fármacos Neuroprotetores , Remielinização , Camundongos , Animais , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização , Modelos Teóricos
7.
Spine (Phila Pa 1976) ; 48(15): E257-E265, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37075330

RESUMO

STUDY DESIGN: Preclinical study. OBJECTIVE: Develop and test a drug delivery system (DDS) composed of anti-inflammatories and growth factors in the rabbit disk injury model. SUMMARY OF BACKGROUND DATA: Biological therapies that inhibit inflammation or enhance cell proliferation can alter intervertebral disk (IVD) homeostasis to favor regeneration. As biological molecules have short half-lives and one molecule may not cover multiple disease pathways, effective treatments may require a combination of growth factors and anti-inflammatory agents delivered in a sustained manner. MATERIALS AND METHODS: Biodegradable microspheres were generated separately to encapsulate tumor necrosis factor alpha (TNFα) inhibitors [etanercept (ETN)] or growth differentiation factor 5 (GDF5) and were embedded into a thermoresponsive hydrogel. Release kinetics and activity of ETN and GDF5 were measured in vitro . For in vivo testing, New Zealand White rabbits (n=12) underwent surgery for disk puncture and treatment with blank-DDS, ETN-DDS, or ETN+GDF5-DDS at levels L34, L45, and L56. Radiographic and magnetic resonance images of the spines were obtained. The IVDs were isolated for histologic and gene expression analyses. RESULTS: ETN and GDF5 were encapsulated into poly (L-lactide-co-glycolide) microspheres and had average initial bursts of 2.4±0.1 and 11.2±0.7 µg from DDS, respectively. In vitro studies confirmed that ETN-DDS inhibited TNFα-induced cytokine release and GDF5-DDS induced protein phosphorylation. In vivo studies showed that rabbit IVDs treated with ETN+GDF5-DDS had better histologic outcomes, higher levels of extracellular, and lower levels of inflammatory gene expression than IVDs treated with blank-DDS or ETN-DDS. CONCLUSIONS: This pilot study demonstrated that DDS can be fabricated to deliver sustained and therapeutic dosages of ETN and GDF5. In addition, ETN+GDF5-DDS may have greater anti-inflammatory and regenerative effects than ETN-DDS alone. Thus, intradiscal injection of controlled release TNF-α inhibitors and growth factors may be a promising treatment to reduce disk inflammation and back pain.


Assuntos
Inibidores do Fator de Necrose Tumoral , Fator de Necrose Tumoral alfa , Coelhos , Animais , Microesferas , Hidrogéis , Fator 5 de Diferenciação de Crescimento/farmacologia , Projetos Piloto , Sistemas de Liberação de Medicamentos , Inflamação/tratamento farmacológico , Anti-Inflamatórios
8.
JOR Spine ; 6(1): e1238, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36994456

RESUMO

Background: In vitro studies using nucleus pulposus (NP) cells are commonly used to investigate disc cell biology and pathogenesis, or to aid in the development of new therapies. However, lab-to-lab variability jeopardizes the much-needed progress in the field. Here, an international group of spine scientists collaborated to standardize extraction and expansion techniques for NP cells to reduce variability, improve comparability between labs and improve utilization of funding and resources. Methods: The most commonly applied methods for NP cell extraction, expansion, and re-differentiation were identified using a questionnaire to research groups worldwide. NP cell extraction methods from rat, rabbit, pig, dog, cow, and human NP tissue were experimentally assessed. Expansion and re-differentiation media and techniques were also investigated. Results: Recommended protocols are provided for extraction, expansion, and re-differentiation of NP cells from common species utilized for NP cell culture. Conclusions: This international, multilab and multispecies study identified cell extraction methods for greater cell yield and fewer gene expression changes by applying species-specific pronase usage, 60-100 U/ml collagenase for shorter durations. Recommendations for NP cell expansion, passage number, and many factors driving successful cell culture in different species are also addressed to support harmonization, rigor, and cross-lab comparisons on NP cells worldwide.

9.
J Acquir Immune Defic Syndr ; 90(S1): S65-S73, 2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35703757

RESUMO

BACKGROUND: Community health worker (CHW) interventions are an evidence-based practice adopted by health care settings to increase retention in care and viral suppression for people living with HIV (PLWH) from racial/ethnic minority communities. However, disparate funding, unclear roles vis a vis other care team members, limited training and promotion opportunities, and a lack of standards for wages and tasks limit the ability to effectively use CHWs as part of the health care team. Guided by the Exploration, Preparation, Implementation, and Sustainment and Reach, Effectiveness, Adoption, Implementation, and Maintenance frameworks, this study describes the key determinants for CHW integration and sustainability at 3 agencies in Shelby County, TN, to improve viral suppression and reduce disparities among rural and urban people living with HIV. SETTING: Memphis Transitional Grant Area (TGA) which includes 8 rural and urban counties in west Tennessee, Arkansas, and Mississippi. METHODS: Seventeen key informants were identified using purposeful and snowball sampling techniques, including community and agency leadership staff, frontline staff, and faith leaders. RESULTS: Key determinants of CHW integration include establishing clear and standardized CHW roles within and across organizations, facilitating interorganizational networks, and leveraging funds for livable CHW wages and sustainable positions. Training strategies that strengthen the CHW workforce include content related to trauma-informed care, managing stress, and cultural humility. CONCLUSION: Several inner and outer settings and innovation and bridging factors affect CHW positions. Data collected will inform the implementation and sustainment of future policies and interventions intended to improve HIV care continuum outcomes and reduce disparities for PLWH.


Assuntos
Agentes Comunitários de Saúde , Infecções por HIV , Agentes Comunitários de Saúde/educação , Etnicidade , Humanos , Ciência da Implementação , Grupos Minoritários , Recursos Humanos
10.
Int J Mol Sci ; 23(11)2022 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-35682964

RESUMO

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system that is characterized by the progressive loss of oligodendrocytes and myelin and is associated with thalamic dysfunction. Cuprizone (CPZ)-induced general demyelination in rodents is a valuable model for studying different aspects of MS pathology. CPZ feeding is associated with the altered distribution and expression of different ion channels along neuronal somata and axons. However, it is largely unknown whether the copper chelator CPZ directly influences ion channels. Therefore, we assessed the effects of different divalent cations (copper; zinc) and trace metal chelators (EDTA; Tricine; the water-soluble derivative of CPZ, BiMPi) on hyperpolarization-activated cyclic nucleotide-gated (HCN) channels that are major mediators of thalamic function and pathology. In addition, alterations of HCN channels induced by CPZ treatment and MS-related proinflammatory cytokines (IL-1ß; IL-6; INF-α; INF-ß) were characterized in C57Bl/6J mice. Thus, the hyperpolarization-activated inward current (Ih) was recorded in thalamocortical (TC) neurons and heterologous expression systems (mHCN2 expressing HEK cells; hHCN4 expressing oocytes). A number of electrophysiological characteristics of Ih (potential of half-maximal activation (V0.5); current density; activation kinetics) were unchanged following the extracellular application of trace metals and divalent cation chelators to native neurons, cell cultures or oocytes. Mice were fed a diet containing 0.2% CPZ for 35 days, resulting in general demyelination in the brain. Withdrawal of CPZ from the diet resulted in rapid remyelination, the effects of which were assessed at three time points after stopping CPZ feeding (Day1, Day7, Day25). In TC neurons, Ih was decreased on Day1 and Day25 and revealed a transient increased availability on Day7. In addition, we challenged naive TC neurons with INF-α and IL-1ß. It was found that Ih parameters were differentially altered by the application of the two cytokines to thalamic cells, while IL-1ß increased the availability of HCN channels (depolarized V0.5; increased current density) and the excitability of TC neurons (depolarized resting membrane potential (RMP); increased the number of action potentials (APs); produced a larger voltage sag; promoted higher input resistance; increased the number of burst spikes; hyperpolarized the AP threshold), INF-α mediated contrary effects. The effect of cytokine modulation on thalamic bursting was further assessed in horizontal slices and a computational model of slow thalamic oscillations. Here, IL-1ß and INF-α increased and reduced oscillatory bursting, respectively. We conclude that HCN channels are not directly modulated by trace metals and divalent cation chelators but are subject to modulation by different MS-related cytokines.


Assuntos
Doenças Desmielinizantes , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização , Animais , Cátions Bivalentes , Quelantes/farmacologia , Cobre , Citocinas , Doenças Desmielinizantes/induzido quimicamente , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/genética , Camundongos , Camundongos Endogâmicos C57BL
11.
Diabetes Care ; 45(8): 1914-1916, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35724307

RESUMO

OBJECTIVE: To evaluate changes in insulin sensitivity, hormone secretion, and hepatic steatosis immediately after caloric restriction, vertical sleeve gastrectomy (VSG), and Roux-en-Y gastric bypass (RYGB). RESEARCH DESIGN AND METHODS: Obese subjects were assessed for 1) insulin sensitivity with hyperinsulinemic-euglycemic clamp with glucose tracer infusion, 2) adipokine concentrations with serum and subcutaneous adipose interstitial fluid sampling, and 3) hepatic fat content with MRI before and 7-10 days after VSG, RYGB, or supervised caloric restriction. RESULTS: Each group exhibited an ∼5% total body weight loss, accompanied by similar improvements in hepatic glucose production and hepatic, skeletal muscle, and adipose tissue insulin sensitivity. Leptin concentrations in plasma and adipose interstitial fluid were equally decreased, and reductions in hepatic fat were similar. CONCLUSIONS: The improvements in insulin sensitivity and adipokine secretion observed early after bariatric surgery are replicated by equivalent caloric restriction and weight loss.


Assuntos
Cirurgia Bariátrica , Derivação Gástrica , Resistência à Insulina , Adipocinas , Glicemia/metabolismo , Restrição Calórica , Gastrectomia , Glucose/metabolismo , Humanos , Resistência à Insulina/fisiologia , Redução de Peso/fisiologia
12.
Pain Med ; 23(2): 288-294, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34601612

RESUMO

The Liaison Committee on Medical Education (LCME) require medical schools to teach their students how to recognize and work toward eliminating health disparities. However, time constraints and a dearth of guidance for educators in teaching pain disparities curricula pose significant challenges. Herein we describe successes and lessons learned after designing, implementing, and evaluating an innovative pain disparities curriculum that was embedded in a longitudinal health equity curriculum for third year medical school students at an academic institution. Although the curriculum was developed for medical school students, the concepts may be broadly applicable to other training settings such as residency and fellowship programs.


Assuntos
Educação Médica , Internato e Residência , Currículo , Humanos , Dor , Faculdades de Medicina
13.
Front Microbiol ; 12: 708904, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34367114

RESUMO

Both acute and chronic cutaneous wounds are often difficult to treat due to the high-risk for bacterial contamination. Once hospitalized, open wounds are at a high-risk for developing hospital-associated infections caused by multi drug-resistant bacteria such as Staphylococcus aureus and Pseudomonas aeruginosa. Treating these infections is challenging, not only because of antibiotic resistance, but also due to the production of biofilms. New treatment strategies are needed that will help in both stimulating the wound healing process, as well as preventing and eliminating bacterial wound infections. Fusaricidins are naturally occurring cyclic lipopeptides with antimicrobial properties that have shown to be effective against a variety of fungi and Gram-positive bacteria, with low toxicity. Continuing with our efforts toward the identification of novel cyclic lipopeptides Fusaricidin analogs, herein we report the synthesis and evaluation of the antimicrobial activity for two novel cyclic lipopeptides (CLP), CLP 2605-4 and CLP 2612-8.1 against methicillin resistant S. aureus and P. aeruginosa, respectively, in in vivo porcine full thickness wound model. Both CLPs were able to reduce bacterial counts by approximately 3 log CFU/g by the last assessment day. Peptide 2612-8.1 slightly enhanced the wound healing, however, wounds treated with peptide 2605-4, have shown higher levels of inflammation and impaired wound healing process. This study highlights the importance of identifying new antimicrobials that can combat bacterial infection while not impeding tissue repair.

14.
Soc Work Public Health ; 36(6): 647-664, 2021 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-34251984

RESUMO

Memphis, Tennessee and its surrounding counties have been profoundly affected by the HIV epidemic. Using a participatory research approach this study identified from a community perspective: 1) the barriers and facilitators for providing support to achieve viral suppression to the most at-risk groups living with HIV in the Memphis Transitional Grant Area and 2) opportunities to strengthen the health care system through the use of community health workers (CHWs) to do outreach and engage with people living with HIV. Themes of barriers include intersectional stigma, HIV criminal laws, abstinence-only sex education, housing, transportation, and limited access to HIV case management and mental health services. Strategies to address these barriers included HIV education to youth in schools and community-wide campaigns, more testing sites, involving faith leaders, funding for housing options, innovative transportation services, rapid start of culturally appropriate HIV medical treatment, intensive case management services, and mental health counseling. Two opportunities to utilize CHWs to address the barriers identified in this geographic area are as policy advocates and as an integrated member of the HIV primary care team. The findings of this study can inform a strategy to build the CHW workforce which may have widespread implications for ending the HIV epidemic in this geographic area and across the United States.


Assuntos
Epidemias , Infecções por HIV , Adolescente , Agentes Comunitários de Saúde , Atenção à Saúde , Epidemias/prevenção & controle , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Humanos , Estigma Social , Estados Unidos
15.
Nat Commun ; 12(1): 1669, 2021 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-33723257

RESUMO

Immune checkpoint inhibitors are used for treating patients with metastatic melanoma. Since the response to treatment is variable, biomarkers are urgently needed to identify patients who may benefit from such therapy. Here, we combine single-cell RNA-sequencing and multiparameter flow cytometry to assess changes in circulating CD8+ T cells in 28 patients with metastatic melanoma starting anti-PD-1 therapy, followed for 6 months: 17 responded to therapy, whilst 11 did not. Proportions of activated and proliferating CD8+ T cells and of mucosal-associated invariant T (MAIT) cells are significantly higher in responders, prior to and throughout therapy duration. MAIT cells from responders express higher level of CXCR4 and produce more granzyme B. In silico analysis support MAIT presence in the tumor microenvironment. Finally, patients with >1.7% of MAIT among peripheral CD8+ population show a better response to treatment. Our results thus suggest that MAIT cells may be considered a biomarker for patients responding to anti-PD-1 therapy.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Células T Invariantes Associadas à Mucosa/imunologia , Células T Invariantes Associadas à Mucosa/metabolismo , Receptor de Morte Celular Programada 1/imunologia , Idoso , Idoso de 80 Anos ou mais , Biomarcadores , Linfócitos T CD8-Positivos/imunologia , Feminino , Granzimas/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Receptores CXCR4/metabolismo
16.
Curr Opin Plant Biol ; 59: 101988, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33388626

RESUMO

Grafting is an ancient technique that involves the physical joining of genotypically distinct shoot and root systems, in order to achieve a desirable compound plant. This practice is widely used in modern agriculture to improve biotic and abiotic stress tolerance, modify plant architecture, induce precocious flowering and rejuvenate old perennial varieties, boost yield, and more. Beneficial new rootstock-scion combinations are currently identified through an inefficient trial and error process, which presents a significant bottleneck for the application of grafting to combat new environmental challenges. Identifying the mechanisms that underlie beneficial grafting-induced traits will facilitate rapid breeding and genetic engineering of new rootstock x scion combinations that exhibit superior performance across varying agricultural environments.


Assuntos
Agricultura , Raízes de Plantas , Raízes de Plantas/genética
17.
Bioorg Med Chem Lett ; 30(11): 127144, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32276831

RESUMO

Ras proteins are small GTPases which regulate cellular proliferation, differentiation, and apoptosis. Constitutively active mutant Ras are expressed in ~15-20% human cancers, and K-Ras mutations account for ~85% of all Ras mutations. Despite the significance of Ras proteins in refractory cancers, there is no anti-Ras drug available in clinic. Since K-Ras must interact with the plasma membrane (PM) for biological activity, inhibition of the K-Ras/PM interaction is a tractable approach to block oncogenic K-Ras activity. Here, we discovered chalcones 1 and 8 exhibit anti-K-Ras activity, and show that the compounds mislocalize K-Ras from the PM and block oncogenic K-Ras signal output. Also, 1 inhibits the growth of K-Ras-driven human cancer cells. Our data suggest that 1 could be a promising starting point for developing anti-K-Ras cancer drug.


Assuntos
Chalconas/química , Transdução de Sinais , Proteínas ras/antagonistas & inibidores , Animais , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Chalconas/metabolismo , Chalconas/farmacologia , Cães , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Células Madin Darby de Rim Canino , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteínas ras/metabolismo
18.
Acta Histochem ; 122(1): 151460, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31668740

RESUMO

BACKGROUND: Diabetic nephropathy is a progressive condition which develops for many years. We analyzed expression of Snail and serum response factor (SRF), epithelial-mesenchymal transition (EMT) regulatory transcription factors with a key role in renal fibrosis, in different renal areas of diabetic rats during ageing. METHODS: Male Sprague-Dawley rats were treated with 55 mg/kg streptozotocin (model of type 1 diabetes mellitus; DM group) or citrate buffer (control). DM group received insulin weekly to prevent ketoacidosis. After 2 weeks, 2, 6 and 12 months kidney samples were collected and analysed in different renal areas. RESULTS: Snail expression was located within cortex in proximal convoluted tubules, in control and DM groups, in the cytoplasm. Percentage of Snail-positive cells in control groups was high and decreased with time, whereas in DM groups the highest percentage was after 2 weeks. In all time points, smaller percentage of Snail expression was seen in DM groups compared to controls. SRF expression was mostly located in the proximal convoluted tubules, always in the cytoplasm. In control groups SRF was expressed in all time periods in proximal convoluted tubules, with decrement after 12 months. Percentage of SRF-positive cells was higher in control groups compared to DM in all time points, with the exception of 12 months. To a smaller degree, SRF expression was seen in the glomeruli and distal convoluted tubules, with more SRF positive cells in DM compared to their control groups. CONCLUSIONS: While Snail expression remained lower in diabetic tissues, compared to controls, expression of SRF increased in diabetic tissues in the second part of the year. These changes may need long time to develop, and, in line with earlier reports, it is possible that insulin treatment of DM rats once a week reduces possibility of EMT and development of renal fibrosis even in the long term.


Assuntos
Envelhecimento , Diabetes Mellitus Experimental , Nefropatias Diabéticas , Regulação da Expressão Gênica , Rim , Fatores de Transcrição da Família Snail/biossíntese , Fatores de Transcrição/biossíntese , Envelhecimento/metabolismo , Envelhecimento/patologia , Animais , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/patologia , Rim/metabolismo , Rim/patologia , Masculino , Ratos , Ratos Sprague-Dawley
19.
Chem Sci ; 11(12): 3146-3151, 2020 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-34122819

RESUMO

Design and implementation of the first (asymmetric) Fe-catalyzed intra- and intermolecular difunctionalization of vinyl cyclopropanes (VCPs) with alkyl halides and aryl Grignard reagents has been realized via a mechanistically driven approach. Mechanistic studies support the diffusion of alkyl radical intermediates out of the solvent cage to participate in an intra- or intermolecular radical cascade with a range of VCPs followed by re-entering the Fe radical cross-coupling cycle to undergo (stereo)selective C(sp2)-C(sp3) bond formation. This work provides a proof-of-concept of the use of vinyl cyclopropanes as synthetically useful 1,5-synthons in Fe-catalyzed conjunctive cross-couplings with alkyl halides and aryl/vinyl Grignard reagents. Overall, we provide new design principles for Fe-mediated radical processes and underscore the potential of using combined computations and experiments to accelerate the development of challenging transformations.

20.
Exp Neurol ; 320: 113012, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31301285

RESUMO

Transcranial focal electrical stimulation (TFS) via tripolar concentric ring electrodes (TCRE), tripolar TFS, is proposed to treat pharmacoresistant epilepsy. We determined the effect of tripolar TFS on electrical amygdaloid kindling (AK) in freely moving cats. Fifteen cats were bilaterally implanted with electrodes in the amygdala (AM) and prefrontal cortex and assigned to three groups: the control group, which only received AK; the tripolar TFS before AK group, in which TCREs were placed over the vertex and tripolar TFS (300 Hz, 200 µs biphasic equal charge, square pulses) was delivered for 40 min just prior to AK; and the tripolar TFS after AK group, in which the TCREs were placed over the temporal bone ipsilateral to the kindled AM, while tripolar TFS was administered for 2 min just after AK onset for 40 days, and, thereafter, only AK was applied. AK was applied daily until all animals reached kindling stage VI. A three concentric spheres finite element cat head model was developed to analyze the electric fields caused by tripolar TFS. Tripolar TFS after AK inhibited kindling development. Animals with tripolar TFS after AK remained at the focal seizure stages for 20 days after tripolar TFS cessation and required 80.0 ±â€¯15.42 AK stimulations to reach stage VI, significantly higher than TFS before AK, and control (P < .001). Tripolar TFS before AK did not show signs of protection against epileptogenesis. The finite modeling of tripolar TFS showed that the electric field is >0.3 mV/mm at depths less than approximately 12.6 mm in the cat brain, which should be strong enough to alter brain activity. In conclusion, tripolar TFS applied via a TCRE over the ipsilateral temporal area significantly delayed AK. This taken together with other reports of tripolar TFS aborting seizures in acute seizure models suggests that tripolar TFS is a promising new modality that should be considered for further testing.


Assuntos
Encéfalo , Eletrodos , Estimulação Transcraniana por Corrente Contínua/instrumentação , Animais , Gatos , Excitação Neurológica , Masculino , Movimento , Convulsões/prevenção & controle
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