Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 852
Filtrar
1.
Cell Oncol (Dordr) ; 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38668817

RESUMO

PURPOSE: Acquired resistance to immune checkpoint blockers (ICBs) is a major barrier in cancer treatment, emphasizing the need for innovative strategies. Dectin-1 (gene Clec7a) is a C-type lectin receptor best known for its ability to recognize ß-glucan-rich structures in fungal cell walls. While Dectin-1 is expressed in myeloid cells and tumor cells, its significance in cancer remains the subject of controversy. METHODS: Using Celc7a-/- mice and curdlan administration to stimulate Dectin-1 signaling, we explored its impact. VISTA KO mice were employed to assess VISTA's role, and bulk RNAseq analyzed curdlan effects on neutrophils. RESULTS: Our findings reveal myeloid cells as primary Dectin-1 expressing cells in the tumor microenvironment (TME), displaying an activated phenotype. Strong Dectin-1 co-expression/co-localization with VISTA and PD-L1 in TME myeloid cells was observed. While Dectin-1 deletion lacked protective effects, curdlan stimulation significantly curtailed B16-F10 tumor progression. RNAseq and pathway analyses supported curdlan's role in triggering a cascade of events leading to increased production of pro-inflammatory mediators, potentially resulting in the recruitment and activation of immune cells. Moreover, we identified a heterogeneous subset of Dectin-1+ effector T cells in the TME. Similar to mice, human myeloid cells are the prominent cells expressing Dectin-1 in cancer patients. CONCLUSION: Our study proposes Dectin-1 as a potential adjunctive target with ICBs, orchestrating a comprehensive engagement of innate and adaptive immune responses in melanoma. This innovative approach holds promise for overcoming acquired resistance to ICBs in cancer treatment, offering avenues for further exploration and development.

2.
Front Mol Biosci ; 11: 1334876, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38645275

RESUMO

Heat shock protein 90 (Hsp90) is a molecular chaperone important for maintaining protein homeostasis (proteostasis) in the cell. Hsp90 inhibitors are being explored as cancer therapeutics because of their ability to disrupt proteostasis. Inhibiting Hsp90 increases surface density of the immunological receptor Major Histocompatibility Complex 1 (MHC1). Here we show that this increase occurs across multiple cancer cell lines and with both cytosol-specific and pan-Hsp90 inhibitors. We demonstrate that Hsp90 inhibition also alters surface expression of both IFNGR and PD-L1, two additional immunological receptors that play a significant role in anti-tumour or anti-immune activity in the tumour microenvironment. Hsp90 also negatively regulates IFN-γ activity in cancer cells, suggesting it has a unique role in mediating the immune system's response to cancer. Our data suggests a strong link between Hsp90 activity and the pathways that govern anti-tumour immunity. This highlights the potential for the use of an Hsp90 inhibitor in combination with another currently available cancer treatment, immune checkpoint blockade therapy, which works to prevent immune evasion of cancer cells. Combination checkpoint inhibitor therapy and the use of an Hsp90 inhibitor may potentiate the therapeutic benefits of both treatments and improve prognosis for cancer patients.

3.
Commun Chem ; 7(1): 84, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38609430

RESUMO

The ability Gram-negative pathogens have at adapting and protecting themselves against antibiotics has increasingly become a public health threat. Data-driven models identifying molecular properties that correlate with outer membrane (OM) permeation and growth inhibition while avoiding efflux could guide the discovery of novel classes of antibiotics. Here we evaluate 174 molecular descriptors in 1260 antimicrobial compounds and study their correlations with antibacterial activity in Gram-negative Pseudomonas aeruginosa. The descriptors are derived from traditional approaches quantifying the compounds' intrinsic physicochemical properties, together with, bacterium-specific from ensemble docking of compounds targeting specific MexB binding pockets, and all-atom molecular dynamics simulations in different subregions of the OM model. Using these descriptors and the measured inhibitory concentrations, we design a statistical protocol to identify predictors of OM permeation/inhibition. We find consistent rules across most of our data highlighting the role of the interaction between the compounds and the OM. An implementation of the rules uncovered in our study is shown, and it demonstrates the accuracy of our approach in a set of previously unseen compounds. Our analysis sheds new light on the key properties drug candidates need to effectively permeate/inhibit P. aeruginosa, and opens the gate to similar data-driven studies in other Gram-negative pathogens.

4.
Cureus ; 16(3): e56463, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38638782

RESUMO

Giant colonic diverticulum (GCD) is a well-recognized but infrequently encountered disease in clinical practice. GCD is its own unique entity and differs from commonly seen diverticular disease in both size and management. Initial clinical presentation is typically associated with diverticulitis and symptoms such as abdominal pain, fever, nausea, vomiting, rectal bleeding, or even a palpable abdominal mass. Surgery is the recommended treatment option largely due to the risk of associated complications including colonic perforation. We describe the case of a 56-year-old female diagnosed with a sigmoid GCD that was successfully stabilized medically and definitively treated surgically.

5.
Clin Nutr ; 43(4): 989-1000, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38484528

RESUMO

BACKGROUND & AIMS: Existing skeletal muscle index (SMI) thresholds for sarcopenia are inconsistent, and do not reflect severity of depletion. In this study we aimed to define criterion values for moderate and severe skeletal muscle depletion based on the risk of mortality in a population of patients with head and neck cancer (HNC). Additionally, we aimed to identify clinical and demographic predictors of skeletal muscle depletion, evaluate the survival impact of skeletal muscle depletion in patients with minimal nutritional risk or good performance status, and finally, benchmarking SMI values of patients with HNC against healthy young adults. METHODS: Population cohort of 1231 consecutive patients and external validation cohorts with HNC had lumbar SMI measured by cross-sectional imaging. Optimal stratification determined sex-specific thresholds for 2-levels of SMI depletion (Class I and II) based on overall survival (OS). Adjusted multivariable regression analyses (tumor site, stage, performance status, age, sex, dietary intake, weight loss) determined relationships between 2-levels of SMI depletion and OS. RESULTS: Mean SMI (cm2/m2) was 51.7 ± 9.9 (males) and 39.8 ± 7.1 (females). The overall and sex-specific population demonstrated an increased risk of mortality associated with decreasing SMI. Sex-specific SMI (cm2/m2) depletion thresholds for 2-levels of muscle depletion determined by optimal stratification for males and females, respectively (male: 45.2-37.5, and <37.5; female: 40.9-34.2, and <34.2). In the overall population, Normal SMI, Class I and II SMI depletion occurred in 65.0%, 24.0%, and 11.0%, respectively. Median OS was: Normal SMI (114 months, 95% CI, 97.1-130.8); Class I SMI Depletion (42 months, 95% CI, 28.5-55.4), and Class II SMI Depletion (15 months, 95% CI, 9.8-20.1). Adjusted multivariable analysis compared with Normal SMI (reference), Class I SMI Depletion (HR, 1.49; 95% CI, 1.18-1.88; P < .001), Class II SMI Depletion (HR, 1.91; 95% CI, 1.42-2.58; P < .001). CONCLUSIONS: Moderate and severe SMI depletion demonstrate discrimination in OS in patients with HNC. Moderate and severe SMI depletion is prevalent in patients with minimal nutrition risk and good performance status. Benchmarking SMI values against healthy young adults exemplifies the magnitude of SMI depletion in patients with HNC and may be a useful method in standardizing SMI assessment.


Assuntos
Neoplasias de Cabeça e Pescoço , Sarcopenia , Adulto Jovem , Humanos , Masculino , Feminino , Sarcopenia/etiologia , Tomografia Computadorizada por Raios X/métodos , Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/patologia , Neoplasias de Cabeça e Pescoço/complicações , Neoplasias de Cabeça e Pescoço/patologia , Estudos Retrospectivos , Prognóstico
6.
J Surg Oncol ; 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38534025

RESUMO

Locally advanced cutaneous squamous cell carcinoma can erode into blood vessels, leading to vascular blowout, requiring emergent surgical intervention. We describe a first case of this disease complication which was effectively managed with endovascular stenting as a bridge to effective systemic and regional therapy. We discuss the efficacy of this staged approach which is novel and timely in a clinical environment of increasingly effective systemic therapies.

7.
Nucleic Acids Res ; 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38416570

RESUMO

CSB (Cockayne syndrome group B) and SMARCAL1 (SWI/SNF-related, matrix-associated, actin-dependent, regulator of chromatin, subfamily A-like 1) are DNA translocases that belong to the SNF2 helicase family. They both are enriched at stalled replication forks. While SMARCAL1 is recruited by RPA32 to stalled forks, little is known about whether RPA32 also regulates CSB's association with stalled forks. Here, we report that CSB directly interacts with RPA, at least in part via a RPA32C-interacting motif within the N-terminal region of CSB. Modeling of the CSB-RPA32C interaction suggests that CSB binds the RPA32C surface previously shown to be important for binding of UNG2 and SMARCAL1. We show that this interaction is necessary for promoting fork slowing and fork degradation in BRCA2-deficient cells but dispensable for mediating restart of stalled forks. CSB competes with SMARCAL1 for RPA32 at stalled forks and acts non-redundantly with SMARCAL1 to restrain fork progression in response to mild replication stress. In contrast to CSB stimulated restart of stalled forks, SMARCAL1 inhibits restart of stalled forks in BRCA2-deficient cells, likely by suppressing BIR-mediated repair of collapsed forks. Loss of CSB leads to re-sensitization of SMARCAL1-depleted BRCA2-deficient cells to chemodrugs, underscoring a role of CSB in targeted cancer therapy.

8.
J Biol Chem ; 300(3): 105690, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38280428

RESUMO

The hydrolytic activity of the ATP synthase in bovine mitochondria is inhibited by a protein called IF1, but bovine IF1 has no effect on the synthetic activity of the bovine enzyme in mitochondrial vesicles in the presence of a proton motive force. In contrast, it has been suggested based on indirect observations that human IFI inhibits both the hydrolytic and synthetic activities of the human ATP synthase and that the activity of human IF1 is regulated by the phosphorylation of Ser-14 of mature IF1. Here, we have made both human and bovine IF1 which are 81 and 84 amino acids long, respectively, and identical in 71.4% of their amino acids and have investigated their inhibitory effects on the hydrolytic and synthetic activities of ATP synthase in bovine submitochondrial particles. Over a wide range of conditions, including physiological conditions, both human and bovine IF1 are potent inhibitors of ATP hydrolysis, with no effect on ATP synthesis. Also, substitution of Ser-14 with phosphomimetic aspartic and glutamic acids had no effect on inhibitory properties, and Ser-14 is not conserved throughout mammals. Therefore, it is unlikely that the inhibitory activity of mammalian IF1 is regulated by phosphorylation of this residue.


Assuntos
Trifosfato de Adenosina , Mitocôndrias , Proteínas Mitocondriais , ATPases Mitocondriais Próton-Translocadoras , Animais , Bovinos , Humanos , Trifosfato de Adenosina/biossíntese , Trifosfato de Adenosina/metabolismo , Aminoácidos/metabolismo , Hidrólise , Mitocôndrias/enzimologia , ATPases Mitocondriais Próton-Translocadoras/genética , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Serina/metabolismo , Fosforilação
9.
Curr Res Transl Med ; 72(1): 103420, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38262189

RESUMO

BACKGROUND: Myeloproliferative neoplasms (MPNs) are a group of disorders of clonal haemopoiesis associated with an inherent risk of arterial and venous thrombotic complications. The prevalence of thrombotic complications and the impact of cardiovascular risk factors (CVRFs) in contemporary patient cohorts within the current era of MPN treatments have not been completely defined. OBJECTIVES: We aim to characterise the cardiovascular risk of patients with MPN by identifying the prevalence of CVRFs and describing the pattern of thrombotic events. We also aim to utilise the QRISK3 algorithm, which is a validated model used to estimate an individual's risk of developing cardiovascular disease, to further phenotype this cohort of patients. METHODS: We perform a retrospective analysis on a single-centre cohort of 438 patients with MPN. RESULTS: MPN patients continue to carry a high burden of vascular morbidity with a prevalence of arterial thrombotic events in 15.8 % (69/438) and venous thrombotic events in 13.2 % (58/438) of the cohort. The novel use of the QRISK3 algorithm, which showed a mean score of 13.7 % across the MPN population, provides further evidence to suggest an increased cardiovascular risk in MPN patients. CONCLUSION: With an increased risk of cardiovascular disease in patients with MPN, we propose an integrated approach between primary and specialised healthcare services using risk stratification tools such as QRISK3, which will allow aggressive optimisation of CVRFs to prevent thrombosis and reduce the overall morbidity and mortality in patients with MPN.


Assuntos
Doenças Cardiovasculares , Transtornos Mieloproliferativos , Neoplasias , Trombose , Humanos , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/complicações , Estudos Retrospectivos , Fatores de Risco , Transtornos Mieloproliferativos/complicações , Transtornos Mieloproliferativos/epidemiologia , Transtornos Mieloproliferativos/genética , Trombose/etiologia , Trombose/genética , Fatores de Risco de Doenças Cardíacas , Neoplasias/complicações
10.
BMC Genomics ; 25(1): 107, 2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38267854

RESUMO

BACKGROUND: Junipers (Juniperus spp.) are woody native, invasive plants that have caused encroachment problems in the U.S. western rangelands, decreasing forage productivity and biodiversity. A potential solution to this issue is using goats in targeted grazing programs. However, junipers, which grow in dry and harsh environmental conditions, use chemical defense mechanisms to deter herbivores. Therefore, genetically selecting goats for increased juniper consumption is of great interest for regenerative rangeland management. In this context, the primary objectives of this study were to: 1) estimate variance components and genetic parameters for predicted juniper consumption in divergently selected Angora (ANG) and composite Boer x Spanish (BS) goat populations grazing on Western U.S. rangelands; and 2) to identify genomic regions, candidate genes, and biological pathways associated with juniper consumption in these goat populations. RESULTS: The average juniper consumption was 22.4% (± 18.7%) and 7.01% (± 12.1%) in the BS and ANG populations, respectively. The heritability estimates (realized heritability within parenthesis) for juniper consumption were 0.43 ± 0.02 (0.34 ± 0.06) and 0.19 ± 0.03 (0.13 ± 0.03) in BS and ANG, respectively, indicating that juniper consumption can be increased through genetic selection. The repeatability values of predicted juniper consumption were 0.45 for BS and 0.28 for ANG. A total of 571 significant SNP located within or close to 231 genes in BS, and 116 SNP related to 183 genes in ANG were identified based on the genome-wide association analyses. These genes are primarily associated with biological pathways and gene ontology terms related to olfactory receptors, intestinal absorption, and immunity response. CONCLUSIONS: These findings suggest that juniper consumption is a heritable trait of polygenic inheritance influenced by multiple genes of small effects. The genetic parameters calculated indicate that juniper consumption can be genetically improved in both goat populations.


Assuntos
Juniperus , Animais , Juniperus/genética , Cabras/genética , Estudo de Associação Genômica Ampla , Espectroscopia de Luz Próxima ao Infravermelho , Patrimônio Genético
11.
J Pharmacol Exp Ther ; 388(2): 232-240, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-37739806

RESUMO

Physical exercise induces physiologic adaptations and is effective at reducing the risk of premature death from all causes. Pharmacological exercise mimetics may be effective in the treatment of a range of diseases including obesity and metabolic syndrome. Previously, we described the development of SLU-PP-332, an agonist for the estrogen-related receptor (ERR)α, ß, and γ nuclear receptors that activates an acute aerobic exercise program. Here we examine the effects of this exercise mimetic in mouse models of obesity and metabolic syndrome. Diet-induced obese or ob/ob mice were administered SLU-PP-332, and the effects on a range of metabolic parameters were assessed. SLU-PP-332 administration mimics exercise-induced benefits on whole-body metabolism in mice including increased energy expenditure and fatty acid oxidation. These effects were accompanied by decreased fat mass accumulation. Additionally, the ERR agonist effectively reduced obesity and improved insulin sensitivity in models of metabolic syndrome. Pharmacological activation of ERR may be an effective method to treat metabolic syndrome and obesity. SIGNIFICANCE STATEMENT: An estrogen receptor-related orphan receptor agonist, SLU-PP-332, with exercise mimetic activity, holds promise as a therapeutic to treat metabolic diseases by decreasing fat mass in mouse models of obesity.


Assuntos
Resistência à Insulina , Síndrome Metabólica , Camundongos , Animais , Síndrome Metabólica/tratamento farmacológico , Obesidade/tratamento farmacológico , Obesidade/metabolismo , Metabolismo Energético , Receptores Citoplasmáticos e Nucleares , Estrogênios
12.
JAMA Surg ; 159(2): 179-184, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38055231

RESUMO

Importance: Individuals who are incarcerated represent a vulnerable group due to concerns about their ability to provide voluntary and informed consent, and there are considerable legal protections regarding their participation in medical research. Little is known about the quality of surgical care received by this population. Objective: To evaluate perioperative surgical care provided to patients who are incarcerated within the Texas Department of Criminal Justice (TDCJ) and compare their outcomes with that of the general nonincarcerated population. Design, Setting, and Participants: This cohort study analyzed data from patients who were incarcerated within the TDCJ and underwent general or vascular surgery at the University of Texas Medical Branch (UTMB) from 2012 to 2021. Case-specific outcomes for a subset of these patients and for patients in the general academic medical center population were obtained from the American College of Surgeons National Quality Improvement Program (ACS-NSQIP) and compared. Additional quality metrics (mortality index, length of stay index, and excess hospital days) from the Vizient Clinical Data Base were analyzed for patients in the incarcerated and nonincarcerated groups who underwent surgery at UTMB in 2020 and 2021 to provide additional recent data. Patient-specific demographics, including age, sex, and comorbidities were not available for analysis within this data set. Main Outcome and Measures: Perioperative outcomes (30-day morbidity, mortality, and readmission rates) were compared between the incarcerated and nonincarcerated groups using the Fisher exact test. Results: The sample included data from 6675 patients who were incarcerated and underwent general or vascular surgery at UTMB from 2012 to 2021. The ACS-NSQIP included data (2012-2021) for 2304 patients who were incarcerated and 602 patients who were not and showed that outcomes were comparable between the TDCJ population and that of the general population treated at the academic medical center with regard to 30-day readmission (6.60% vs 5.65%) and mortality (0.91% vs 1.16%). However, 30-day morbidity was significantly higher in the TDCJ population (8.25% vs 5.48%, P = .01). The 2020 and 2021 data from the Vizient Clinical Data Base included 629 patients who were incarcerated and 2614 who were not and showed that the incarcerated and nonincarcerated populations did not differ with regard to 30-day readmission (12.52% vs 11.30%) or morbidity (1.91% vs 2.60%). Although the unadjusted mortality rate was significantly lower in the TDCJ population (1.27% vs 2.68%, P = .04), mortality indexes, which account for case mix index, were similar between the 2 populations (1.17 vs 1.12). Conclusions and Relevance: Findings of this cohort study suggest that patients who are incarcerated have equivalent rates of mortality and readmission compared with a general academic medical center population. Future studies that focus on elucidating the potential factors associated with perioperative morbidity and exploring long-term surgical outcomes in the incarcerated population are warranted.


Assuntos
Direito Penal , Complicações Pós-Operatórias , Humanos , Complicações Pós-Operatórias/mortalidade , Estudos de Coortes , Procedimentos Cirúrgicos Vasculares , Melhoria de Qualidade , Atenção à Saúde
13.
Circulation ; 149(3): 227-250, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-37961903

RESUMO

BACKGROUND: Cardiac metabolic dysfunction is a hallmark of heart failure (HF). Estrogen-related receptors ERRα and ERRγ are essential regulators of cardiac metabolism. Therefore, activation of ERR could be a potential therapeutic intervention for HF. However, in vivo studies demonstrating the potential usefulness of ERR agonist for HF treatment are lacking, because compounds with pharmacokinetics appropriate for in vivo use have not been available. METHODS: Using a structure-based design approach, we designed and synthesized 2 structurally distinct pan-ERR agonists, SLU-PP-332 and SLU-PP-915. We investigated the effect of ERR agonist on cardiac function in a pressure overload-induced HF model in vivo. We conducted comprehensive functional, multi-omics (RNA sequencing and metabolomics studies), and genetic dependency studies both in vivo and in vitro to dissect the molecular mechanism, ERR isoform dependency, and target specificity. RESULTS: Both SLU-PP-332 and SLU-PP-915 significantly improved ejection fraction, ameliorated fibrosis, and increased survival associated with pressure overload-induced HF without affecting cardiac hypertrophy. A broad spectrum of metabolic genes was transcriptionally activated by ERR agonists, particularly genes involved in fatty acid metabolism and mitochondrial function. Metabolomics analysis showed substantial normalization of metabolic profiles in fatty acid/lipid and tricarboxylic acid/oxidative phosphorylation metabolites in the mouse heart with 6-week pressure overload. ERR agonists increase mitochondria oxidative capacity and fatty acid use in vitro and in vivo. Using both in vitro and in vivo genetic dependency experiments, we show that ERRγ is the main mediator of ERR agonism-induced transcriptional regulation and cardioprotection and definitively demonstrated target specificity. ERR agonism also led to downregulation of cell cycle and development pathways, which was partially mediated by E2F1 in cardiomyocytes. CONCLUSIONS: ERR agonists maintain oxidative metabolism, which confers cardiac protection against pressure overload-induced HF in vivo. Our results provide direct pharmacologic evidence supporting the further development of ERR agonists as novel HF therapeutics.


Assuntos
Insuficiência Cardíaca , Camundongos , Animais , Cardiomegalia/metabolismo , Mitocôndrias/metabolismo , Miócitos Cardíacos/metabolismo , Receptores de Estrogênio/genética , Receptores de Estrogênio/metabolismo , Ácidos Graxos/metabolismo
14.
Oncologist ; 29(1): 57-66, 2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-37648247

RESUMO

BACKGROUND: Adjuvant therapies have been approved for resected melanoma based on improved recurrence-free survival. We present early findings from a real-world study on adjuvant treatments for melanoma. METHODS: A comprehensive chart review was conducted for patients receiving adjuvant systemic therapy for resected high-risk stages III and IV melanoma. Statistical analysis was performed to assess recurrence-free survival and subgroup differences. RESULTS: A total of 149 patients (median age = 58.0 years, 61.1% men, 49.7% with BRAF V600E/K genotypes) were included, with 94.6% having resected stage III melanoma. Anti-PD-1 immunotherapy was received by 86.5% of patients, while 13.4% received BRAF-targeted therapy. At a median follow-up of 22.4 months, the recurrence rate was 31.5%, with 1-year and 2-year recurrence-free survival rates of 79% and 62%, respectively. Similar recurrence rates were observed between anti-PD-1 immunotherapy and BRAF-targeted therapy. Long-term toxicity affected 27.4% of patients, with endocrinopathies and late-emergent immune-related adverse events being common. CONCLUSIONS: Real-world adjuvant systemic therapy aligns with clinical trial practice. Recurrence rates remain high despite treatment, and long-term toxicities, including endocrinopathies and chronic inflammatory conditions, are not uncommon.


Assuntos
Melanoma , Neoplasias Cutâneas , Masculino , Humanos , Pessoa de Meia-Idade , Feminino , Melanoma/tratamento farmacológico , Melanoma/genética , Melanoma/cirurgia , Proteínas Proto-Oncogênicas B-raf/genética , Estudos Retrospectivos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Cutâneas/tratamento farmacológico
15.
J Vasc Interv Radiol ; 35(1): 122-126, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37696430

RESUMO

PURPOSE: To develop a reproducible in vitro model simulating central venous catheter (CVC) exchange with high potential for air embolization and test the hypothesis that a closed catheter clamp over hydrophilic guide wire exchange technique will significantly reduce the volume of air introduced during CVC exchange. MATERIALS AND METHODS: The model consisted of a 16-F valved sheath, 240-mL container, and pressure transducer submerged in water in a 1,200-mL suction canister system. Continuous wall suction was applied to the canister to maintain negative pressure at -7 mm Hg or -11 mm Hg. Each trial consisted of 0.035-inch hydrophilic guide wire introduction, over-the-wire catheter exchange, and wire removal following clinical protocol. A total of 256 trials were performed, 128 trials at each pressure with the catheter clamp open (n = 64) or closed (n = 64) around the hydrophilic guide wire. RESULTS: There was a statistically significant lower volume of air introduced with closed clamp over-the-wire exchanges than with open clamp exchanges at both pressures (2-tailed t-test, P < .001). At -7 mm Hg, a mean of 48.0 mL (SD ± 9.3) of air was introduced with open clamp and 20.6 mL (SD ± 4.7) of air was introduced with closed clamp. At -11 mm Hg, 97.8 mL (SD ± 11.9) of air was introduced with open clamp and 37.8 mL (SD ± 6.3) of air was introduced with closed clamp. CONCLUSIONS: This study demonstrated the use of a reproducible in vitro model mimicking conditions causing air embolism during CVC exchange. Results showed that CVC exchange using closed catheter clamp over hydrophilic guide wire exchange technique significantly reduced the volume of air introduced per exchange.


Assuntos
Cateterismo Venoso Central , Cateteres Venosos Centrais , Embolia Aérea , Humanos , Cateteres Venosos Centrais/efeitos adversos , Embolia Aérea/etiologia , Embolia Aérea/prevenção & controle , Cateterismo Venoso Central/efeitos adversos , Cateterismo Venoso Central/métodos
16.
J Immunol ; 212(4): 689-701, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38149922

RESUMO

The classical pathway (CP) is a potent mechanism for initiating complement activity and is a driver of pathology in many complement-mediated diseases. The CP is initiated via activation of complement component C1, which consists of the pattern recognition molecule C1q bound to a tetrameric assembly of proteases C1r and C1s. Enzymatically active C1s provides the catalytic basis for cleavage of the downstream CP components, C4 and C2, and is therefore an attractive target for therapeutic intervention in CP-driven diseases. Although an anti-C1s mAb has been Food and Drug Administration approved, identifying small-molecule C1s inhibitors remains a priority. In this study, we describe 6-(4-phenylpiperazin-1-yl)pyridine-3-carboximidamide (A1) as a selective, competitive inhibitor of C1s. A1 was identified through a virtual screen for small molecules that interact with the C1s substrate recognition site. Subsequent functional studies revealed that A1 dose-dependently inhibits CP activation by heparin-induced immune complexes, CP-driven lysis of Ab-sensitized sheep erythrocytes, CP activation in a pathway-specific ELISA, and cleavage of C2 by C1s. Biochemical experiments demonstrated that A1 binds directly to C1s with a Kd of ∼9.8 µM and competitively inhibits its activity with an inhibition constant (Ki) of ∼5.8 µM. A 1.8-Å-resolution crystal structure revealed the physical basis for C1s inhibition by A1 and provided information on the structure-activity relationship of the A1 scaffold, which was supported by evaluating a panel of A1 analogs. Taken together, our work identifies A1 as a new class of small-molecule C1s inhibitor and lays the foundation for development of increasingly potent and selective A1 analogs for both research and therapeutic purposes.


Assuntos
Complemento C1s , Via Clássica do Complemento , Animais , Ovinos , Peptídeo Hidrolases , Complemento C1/metabolismo , Endopeptidases , Piridinas/farmacologia
17.
Nature ; 624(7992): 621-629, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38049589

RESUMO

Type 2 diabetes mellitus (T2D), a major cause of worldwide morbidity and mortality, is characterized by dysfunction of insulin-producing pancreatic islet ß cells1,2. T2D genome-wide association studies (GWAS) have identified hundreds of signals in non-coding and ß cell regulatory genomic regions, but deciphering their biological mechanisms remains challenging3-5. Here, to identify early disease-driving events, we performed traditional and multiplexed pancreatic tissue imaging, sorted-islet cell transcriptomics and islet functional analysis of early-stage T2D and control donors. By integrating diverse modalities, we show that early-stage T2D is characterized by ß cell-intrinsic defects that can be proportioned into gene regulatory modules with enrichment in signals of genetic risk. After identifying the ß cell hub gene and transcription factor RFX6 within one such module, we demonstrated multiple layers of genetic risk that converge on an RFX6-mediated network to reduce insulin secretion by ß cells. RFX6 perturbation in primary human islet cells alters ß cell chromatin architecture at regions enriched for T2D GWAS signals, and population-scale genetic analyses causally link genetically predicted reduced RFX6 expression with increased T2D risk. Understanding the molecular mechanisms of complex, systemic diseases necessitates integration of signals from multiple molecules, cells, organs and individuals, and thus we anticipate that this approach will be a useful template to identify and validate key regulatory networks and master hub genes for other diseases or traits using GWAS data.


Assuntos
Diabetes Mellitus Tipo 2 , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Predisposição Genética para Doença , Ilhotas Pancreáticas , Humanos , Estudos de Casos e Controles , Separação Celular , Cromatina/metabolismo , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Diabetes Mellitus Tipo 2/fisiopatologia , Redes Reguladoras de Genes/genética , Estudo de Associação Genômica Ampla , Secreção de Insulina , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/patologia , Reprodutibilidade dos Testes
18.
Plast Reconstr Surg Glob Open ; 11(11): e5374, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37936827

RESUMO

Background: Poland syndrome is classically described as symbrachydactyly, with hypoplasia of the pectoralis major and other upper thoracic musculoskeletal structures. It is thought to be caused by intrauterine interruption in subclavian arterial flow and often includes breast hypoplasia. Affected vasculature can pose a challenge for reconstruction with free flaps because inflow may not be reliable in this patient population. Methods: We present the rare case of a 28-year-old woman with left-sided Poland syndrome, significant family history of breast cancer, and BRCA1+ mutation who underwent bilateral prophylactic nipple-sparing mastectomies with successful immediate bilateral deep inferior epigastric artery perforator free flap reconstruction. The surgical literature in this clinical scenario is also reviewed. Results: Preoperative computed tomography angiography of the chest successfully demonstrated the patency and quantified the caliber of the internal mammary vessels to support free flap breast reconstruction. Conclusions: Free tissue transfer is a viable option for breast reconstruction in patients with Poland syndrome undergoing mastectomy guided by preoperative computed tomography angiography to characterize the internal mammary vasculature.

19.
J Vis Exp ; (201)2023 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-37982512

RESUMO

The pancreatic islets of Langerhans, which are small 3D collections of specialized endocrine and supporting cells interspersed throughout the pancreas, have a central role in the control of glucose homeostasis through the secretion of insulin by beta cells, which lowers blood glucose, and glucagon by alpha cells, which raises blood glucose. Intracellular signaling pathways, including those mediated by cAMP, are key for regulated alpha and beta cell hormone secretion. The 3D islet structure, while essential for coordinated islet function, presents experimental challenges for mechanistic studies of the intracellular signaling pathways in primary human islet cells. To overcome these challenges and limitations, this protocol describes an integrated live-cell imaging and microfluidic platform using primary human pseudoislets generated from donors without diabetes that resemble native islets in their morphology, composition, and function. These pseudoislets are size-controlled through the dispersion and reaggregation process of primary human islet cells. In the dispersed state, islet cell gene expression can be manipulated; for example, biosensors such as the genetically encoded cAMP biosensor, cADDis, can be introduced. Once formed, pseudoislets expressing a genetically encoded biosensor, in combination with confocal microscopy and a microperifusion platform, allow for the synchronous assessment of fluorescent biosensor dynamics and alpha and beta cell hormone secretory profiles to provide more insight into cellular processes and function.


Assuntos
Células Secretoras de Insulina , Ilhotas Pancreáticas , Humanos , Glicemia , Transporte Biológico , Insulina , Corantes
20.
Mol Oncol ; 2023 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-37681284

RESUMO

Human papillomavirus (HPV)-associated cancer continues to evade the immune system by promoting a suppressive tumor microenvironment. Therefore, immunotherapy appears to be a promising approach for targeting HPV-associated tumors. We hypothesized that valproic acid (VA) as an epigenetic agent combined with avelumab may enhance the antitumor immunity in HPV-associated solid tumors. We performed bulk RNA-sequencing (RNA-Seq) on total peripheral blood mononuclear cells (PBMCs) of seven nonresponders (NRs) and four responders (Rs). A total of 39 samples (e.g., pretreatment, post-VA, postavelumab, and endpoint) were analyzed. Also, we quantified plasma analytes and performed flow cytometry. We observed a differential pattern in immune response following treatment with VA and/or avelumab in NRs vs. Rs. A significant upregulation of transcripts associated with NETosis [the formation of neutrophil extracellular traps (NETs)] and neutrophil degranulation pathways was linked to the presence of a myeloid-derived suppressor cell signature in NRs. We noted the elevation of IL-8/IL-18 cytokines and a distinct transcriptome signature at the baseline and endpoint in NRs. By using the receiver operator characteristics, we identified a cutoff value for the plasma IL-8/IL-18 to discriminate NRs from Rs. We found differential therapeutic effects for VA and avelumab in NRs vs. Rs. Thus, our results imply that measuring the plasma IL-8/IL-18 and bulk RNA-Seq of PBMCs may serve as valuable biomarkers to predict immunotherapy outcomes.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...