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1.
Bioengineering (Basel) ; 11(5)2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38790314

RESUMO

Excessive fibrosis and resultant poor control of intraocular pressure (IOP) reduce the efficacy of glaucoma surgeries. Historically, corticosteroids and anti-fibrotic agents, such as mitomycin C (MMC) and 5-fluorouracil (5-FU), have been used to mitigate post-surgical fibrosis, but these have unpredictable outcomes. Therefore, there is a need to develop novel treatments which provide increased effectiveness and specificity. This review aims to provide insight into the pathophysiology behind wound healing in glaucoma surgery, as well as the current and promising future wound healing agents that are less toxic and may provide better IOP control.

2.
Biochem Pharmacol ; 222: 116052, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38354957

RESUMO

The cannabinoid CB1 receptor (CB1) is a G protein-coupled receptor (GPCR) with widespread expression in the central nervous system. This canonically G⍺i/o-coupled receptor mediates the effects of Δ9-tetrahydrocannabinol (THC) and synthetic cannabinoid receptor agonists (SCRAs). Recreational use of SCRAs is associated with serious adverse health effects, making pharmacological research into these compounds a priority. Several studies have hypothesised that signalling bias may explain the different toxicological profiles between SCRAs and THC. Previous studies have focused on bias between G protein activation measured by cyclic adenosine monophosphate (cAMP) inhibition and ß-arrestin translocation. In contrast, the current study characterises bias between G⍺ subtypes of the G⍺i/o family and ß-arrestins; this method facilitates a more accurate assessment of ligand bias by assessing signals that have not undergone major amplification. We have characterised G protein dissociation and translocation of ß-arrestin 1 and 2 using real-time BRET reporters. The responses produced by each SCRA across the G protein subtypes tested were consistent with the responses produced by the reference ligand AMB-FUBINACA. Ligand bias was probed by applying the operational analysis to determine biases within the G⍺i/o family, and between G protein subtypes and ß-arrestins. Overall, these results confirm SCRAs to be balanced, high-efficacy ligands compared to the low efficacy ligand THC, with only one SCRA, 4CN-MPP-BUT7IACA, demonstrating statistically significant bias in one pathway comparison (towards ß-arrestin 1 when compared with G⍺oA/oB). This suggests that the adverse effects caused by SCRAs are due to high potency and efficacy at CB1, rather than biased agonism.


Assuntos
Agonistas de Receptores de Canabinoides , Canabinoides , Agonistas de Receptores de Canabinoides/farmacologia , Agonistas de Receptores de Canabinoides/metabolismo , beta-Arrestinas/metabolismo , Receptores de Canabinoides/metabolismo , beta-Arrestina 1/metabolismo , Ligantes , Proteínas de Ligação ao GTP/metabolismo , Canabinoides/farmacologia , Receptor CB1 de Canabinoide/metabolismo , Receptor CB2 de Canabinoide/metabolismo
3.
J Natl Compr Canc Netw ; 22(2D)2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-38181507

RESUMO

Ampullary carcinomas are rare but increasing in incidence. Ampullary cancers have molecular alterations that guide choice of therapy, particularly in nonresectable cases. These alterations can be more common by subtype (intestinal, pancreaticobiliary, or mixed), and next-generation sequencing is recommended for all patients who cannot undergo surgery. In this article, we review the approach to tissue acquisition and consideration for molecular testing. Common molecular targets of interest in ampullary cancer are also discussed in this review, including HER2/ERBB2, HER3, tumor mutational burden, microsatellite instability, KRAS, and germline BRCA and ATM mutations, along with emerging and rarer alterations.


Assuntos
Ampola Hepatopancreática , Neoplasias do Ducto Colédoco , Terapia de Alvo Molecular , Humanos , Ampola Hepatopancreática/patologia , Terapia de Alvo Molecular/métodos , Neoplasias do Ducto Colédoco/terapia , Neoplasias do Ducto Colédoco/diagnóstico , Neoplasias do Ducto Colédoco/genética , Neoplasias do Ducto Colédoco/patologia , Mutação , Biomarcadores Tumorais/genética
4.
Eur Heart J ; 45(3): 181-194, 2024 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-37634192

RESUMO

BACKGROUND AND AIMS: Coronary flow capacity (CFC) is associated with an observed 10-year survival probability for individual patients before and after actual revascularization for comparison to virtual hypothetical ideal complete revascularization. METHODS: Stress myocardial perfusion (mL/min/g) and coronary flow reserve (CFR) per pixel were quantified in 6979 coronary artery disease (CAD) subjects using Rb-82 positron emission tomography (PET) for CFC maps of artery-specific size-severity abnormalities expressed as percent left ventricle with prospective follow-up to define survival probability per-decade as fraction of 1.0. RESULTS: Severely reduced CFC in 6979 subjects predicted low survival probability that improved by 42% after revascularization compared with no revascularization for comparable severity (P = .0015). For 283 pre-and-post-procedure PET pairs, severely reduced regional CFC-associated survival probability improved heterogeneously after revascularization (P < .001), more so after bypass surgery than percutaneous coronary interventions (P < .001) but normalized in only 5.7%; non-severe baseline CFC or survival probability did not improve compared with severe CFC (P = .00001). Observed CFC-associated survival probability after actual revascularization was lower than virtual ideal hypothetical complete post-revascularization survival probability due to residual CAD or failed revascularization (P < .001) unrelated to gender or microvascular dysfunction. Severely reduced CFC in 2552 post-revascularization subjects associated with low survival probability also improved after repeat revascularization compared with no repeat procedures (P = .025). CONCLUSIONS: Severely reduced CFC and associated observed survival probability improved after first and repeat revascularization compared with no revascularization for comparable CFC severity. Non-severe CFC showed no benefit. Discordance between observed actual and virtual hypothetical post-revascularization survival probability revealed residual CAD or failed revascularization.


Assuntos
Doença da Artéria Coronariana , Humanos , Radioisótopos de Rubídio , Estudos Prospectivos , Tomografia por Emissão de Pósitrons/métodos , Angiografia Coronária/métodos
6.
JCO Oncol Pract ; 19(10): 899-906, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37708434

RESUMO

PURPOSE: Prime childbearing years occur during medical training and early career, leaving physicians with tough choices between family planning and career growth. Restrictive workplace parental leave (PL) policies may negatively affect physician well-being. We evaluate existing PL and lactation policies, as well as return-to-work experiences, among oncology trainees and early-career faculty. METHODS: An anonymous 43-question cross-sectional survey was distributed via e-mail and social media channels between May and June 2021 to oncology trainees and physicians within 5 years of terminal training in the United States. The survey was administered through SurveyMonkey. Descriptive statistics were used to analyze data. Two hundred seventy-five participants were recruited via social media and outreach to program directors and coordinators in adult hematology/oncology and radiation oncology program directors. RESULTS: The average duration of PL was <6 weeks for most participants. Among those who used PL, 50% felt pressured to work while on PL, 60% felt guilty asking coworkers for help, and 79% were overwhelmed with demands of work and home, whereas only 27% had resources available at workplace to assist with transition back to work. Among those who breastfed at return to work, 31% did not have access to a lactation room, 56% did not have adequate pumping breaks, and 66% did not have pumping breaks mandated in contract. CONCLUSION: Our findings underline the immense magnitude of problems surrounding inadequate PL and support for lactating mothers among trainees and early-career physicians in oncology subspecialities. Policies and practices around PL and lactation should be restructured to meet the needs of the evolving oncology workforce.

7.
Cancer Med ; 12(11): 12802-12812, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37151163

RESUMO

BACKGROUND: Although barriers to trial accrual are well-reported, few studies have explored trial eligibility and trial offers as potential drivers of disparities in cancer clinical trial enrollment. METHODS: We identified patients with gastrointestinal (GI) or head/neck (HN) malignancies who were seen as new patients at the University of Michigan Health Rogel Cancer Center in 2016. By exhaustive review of the electronic medical record, we assessed the primary outcomes: (1) eligibility for, (2) documented offer of, and (3) enrollment in a clinical trial. All 41 of the clinical trials available to these patients were considered. Independent variables included clinical and non-clinical patient-related factors. We assessed associations between these variables and the primary outcomes using multivariable regression. RESULTS: Of 1446 patients, 43% were female, 15% were over age 75, 6% were Black. 305 (21%) patients were eligible for a clinical trial. Among eligible patients, 154 (50%) had documentation of a trial offer and 90 (30%) enrolled. Among the GI cohort, bivariate analyses demonstrated that older age was associated with decreased trial eligibility. Bivariate analyses also demonstrated that Black race was associated with increased trial offer. After adjustment, patients 75 or older were less likely to be eligible for a clinical trial in the GI cohort; however, we found no significant associations between race and any of the outcomes after adjustment. Among eligible GI patients, we found no significant associations between non-clinical factors and enrollment. Among the HN cohort, bivariate analyses demonstrated that female sex, older age, Black race, and unpartnered marital status were associated with decreased likelihood of trial offer; however, we found no significant associations between race, age, and marital status and any of the outcomes after adjustment. We found no significant associations between non-clinical factors and eligibility after adjustment; however, women were less likely to be offered and to enroll in a clinical trial in the HN cohort. CONCLUSION: Factors associated with eligibility, documented offer, and enrollment differed between disease site cohorts at our institution. Future work is needed to ensure the equitable inclusion of women and elderly patients in clinical trials.


Assuntos
Ensaios Clínicos como Assunto , Neoplasias , Seleção de Pacientes , Idoso , Feminino , Humanos , Masculino , Modelos Logísticos , Neoplasias/epidemiologia , Neoplasias/terapia , Negro ou Afro-Americano
8.
Cureus ; 14(7): e26989, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35989742

RESUMO

Fusobacterium nucleatum is a strict anaerobe that is indigenous to the human oral cavity, where it coexists with more than 500 other species. It is associated with paranasal sinus, odontogenic, and pulmonary infections. In literature, cases of Fusobacterium nucleatum are rare. Here we report a case of a patient with multiple brain abscesses caused by Fusobacterium nucleatum. This case report looks to assist clinicians in determining the true etiology of this organism, which can change patient management based on the current literature review and similar case studies.

9.
J Clin Oncol ; 40(24): 2751-2762, 2022 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-35839430

RESUMO

Immunotherapy (IO) agents have led to significant improvements in patient outcomes across many tumor types. There have been great efforts to introduce immune checkpoint inhibitors into the treatment paradigm of esophagogastric cancers as well. A number of randomized phase III trials, which will be reviewed here, established the role of these agents in both early-stage and advanced-stage disease. Adjuvant nivolumab is US Food and Drug Administration-approved after neoadjuvant chemoradiation and resection of esophageal and gastroesophageal junction cancers on the basis of the phase III CheckMate 577 trial. In the advanced setting, patients with programmed death receptor ligand-1-positive tumors should be recommended IO in combination with chemotherapy in the first-line setting on the basis of the results from KEYNOTE 590, CheckMate 649, and CheckMate 648. Across trials, chemotherapy continues to play a critical role in the first-line setting and should be offered to all patients who are eligible for systemic therapy, including those with biomarker select tumors. In the later lines of treatment, IO has modest activity, and prior studies have grown largely irrelevant because of the enrollment of IO-naive patients. Similar to other disease types, patients with microsatellite unstable (microsatellite instability high) tumors represent a unique cohort that is more sensitive to IO. However, there are no randomized studies evaluating how best to apply IO in early or advanced stages specifically for the treatment of patients with microsatellite instability high upper GI tumors. Questions remain how to best select patients who benefit from IO treatments, how to augment IO activity in programmed death receptor ligand-1-negative tumors, and how to incorporate IO in late-line settings or for recurrent disease that has been treated with IO-containing regimens during early stages.


Assuntos
Neoplasias Esofágicas , Neoplasias Gástricas , Neoplasias Esofágicas/tratamento farmacológico , Neoplasias Esofágicas/terapia , Humanos , Imunoterapia/métodos , Ligantes , Instabilidade de Microssatélites , Receptores de Morte Celular , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/terapia
11.
Curr Treat Options Oncol ; 22(11): 103, 2021 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-34586537

RESUMO

OPINION STATEMENT: ACs are rare tumors, and thus, there is a lack of prospective trials supporting treatment decisions. Moreover, although anatomically uniform, ACs comprise of biologically distinct entities, depending on what cell type they arise from. This makes the interpretation of limited data even more challenging. Overall, the clinical outcomes of patients with AC are better than those with pancreatic cancer. However, recurrence rates remain high after curative resection. Despite the absence of definitive evidence, we believe that these high recurrence rates are a rational justification for consideration of adjuvant therapy in resected disease, and therapy selection should take tumor biology, stage, resection margins, as well as patient comorbidities and performance status into account. Largely extrapolating from pancreas cancer, we recommend consideration of adjuvant chemotherapy with 6 months of dose-modified FOLFIRINOX in fit patients with pancreatobiliary subtype tumors. Alternative regimens include gemcitabine in combination with capecitabine. If chemoradiotherapy is being added, 6 weeks of radiotherapy in conjunction with 5-FU or capecitabine can be considered. For intestinal subtypes, we recommend 3-6 months of adjuvant FOLFOX. Future studies are needed to evaluate the role of contemporary, multi-agent chemotherapy and chemoradiotherapy in patients with resected and advanced ampullary adenocarcinoma. However, the logistics of performing large randomized trials in patients with a rare cancer is challenging, and the data collection, even in a carefully designed study, would likely take many years. As such, relying on data from basket trials and retrospective analysis will likely serve as guidance for treatment decisions in the near future. Treatment of metastatic disease should employ regimens that are typically used to treat pancreas cancer for tumors of pancreatobiliary subtype and 5-FU-based regimens for intestinal subtypes. Studies specific for patients with advanced AC are much needed. Molecular testing using next-generation sequencing and testing for microsatellite instability (MSI) should be performed on all tumors. We now have disease agnostic options based on these results. Pembrolizumab is approved for MSI-H tumors and tumors with high tumor mutational burden regardless of the primary site. Larotrectinib is approved for tumors with NTRK fusions. At a time when numerous therapeutic agents are in development, for example, those targeting specific K-RAS alterations or NRG fusions, identifying molecular aberrations can significantly impact patient outcomes as well as provide further insights into the biology of disease. In addition, based on recent data suggesting a significant prevalence of germline alterations in patients with ampullary tumors, referral to genetics counselors and germline testing is warranted in a significant proportion of patients with AC.


Assuntos
Adenocarcinoma/terapia , Ampola Hepatopancreática/patologia , Neoplasias do Ducto Colédoco/terapia , Adenocarcinoma/diagnóstico , Adenocarcinoma/etiologia , Adenocarcinoma/mortalidade , Tomada de Decisão Clínica , Terapia Combinada/efeitos adversos , Terapia Combinada/métodos , Neoplasias do Ducto Colédoco/diagnóstico , Neoplasias do Ducto Colédoco/etiologia , Neoplasias do Ducto Colédoco/mortalidade , Gerenciamento Clínico , Suscetibilidade a Doenças , Humanos , Prognóstico , Resultado do Tratamento
12.
J Oncol Pharm Pract ; 27(8): 2014-2017, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33765873

RESUMO

INTRODUCTION: We report the case of a patient who experienced severe neurological symptoms collectively characterized as being "frozen" following a second oxaliplatin infusion. CASE REPORT: A 52-year-old woman with metastatic colon cancer developed severe motor slowing, delayed and incomplete grip and dorsiflexion, speech difficulty, visual impairment, leg cramping and tingling after her second infusion of oxaliplatin. She was transferred from the infusion center to the emergency room and admitted to the hospital for further evaluation. Motor, verbal, and ocular symptoms gradually resolved within 24 hours, and she was discharged home without sequela.Management and outcome: Oxaliplatin dose was subsequently lowered and infusion time increased, and she tolerated future treatments without motor, verbal, or ocular disturbance. DISCUSSION: In this case report, we describe a rare form of neurological toxicity involving severe motor slowing, slurred speech, and blurry vision secondary to oxaliplatin.


Assuntos
Neoplasias do Colo , Neoplasias do Colo/tratamento farmacológico , Feminino , Humanos , Pessoa de Meia-Idade , Oxaliplatina
13.
Breast Cancer Res Treat ; 184(2): 507-518, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32757135

RESUMO

PURPOSE: Although many studies clearly demonstrate disparities in cancer clinical trial enrollment, there is a lack of consensus on potential causes. Furthermore, virtually nothing is known about associations between patients' decision-making style and their participation in clinical trials. METHODS: Women with newly diagnosed, stage 0-II breast cancer reported to the Georgia and Los Angeles County Surveillance, Epidemiology, and End Results (SEER) registries in 2013-2014 were surveyed approximately seven months after diagnosis. We investigated two primary outcome variables: (1) invitation to participate in a clinical trial, (2) participation in a clinical trial. We evaluated bivariate associations using Chi-squared tests and used multivariable logistic regression models to investigate associations between patient variables, including decision-making style, and the primary outcomes. RESULTS: 2578 patients responded (71% response rate); 30% were > age 65, 18% were black, 18% were Latina, 29% had ≤ high school education. 10% of patients reported invitation to participate in a clinical trial; 5% reported participation in a clinical trial. After adjustment younger age, receipt of chemotherapy or radiation, disease stage, and a more rational (versus more intuitive) decision-making style were associated with a higher odds of invitation to participate. Being married was associated with a higher odds of participation; having an annual family income ≥ $40,000 was associated with a lower odds of participation. CONCLUSIONS: 10% of patients reported invitation to participate in a clinical trial, and half of these reported participation. Invitation to participate varied by age and decision-making style, and participation varied by marital status and income.


Assuntos
Neoplasias da Mama , Adulto , Negro ou Afro-Americano , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/terapia , Feminino , Georgia , Hispânico ou Latino , Humanos , Pessoa de Meia-Idade , Participação do Paciente , Programa de SEER
14.
Biochem Pharmacol ; 175: 113871, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32088263

RESUMO

Synthetic cannabinoid receptor agonists (SCRAs) represent the most rapidly proliferating class of "designer drugs" or "new psychoactive substances". SCRAs offer unregulated alternatives to cannabis that evade routine drug tests, but their use is increasingly associated with severe toxicity and death worldwide. Little is currently known about SCRA molecular pharmacology, or the mechanisms underpinning their toxicity, although the effects are believed to be primarily mediated by the type 1 cannabinoid receptor (CB1). In this study, we aimed to characterise the signalling profiles of a structurally diverse panel of novel SCRAs at CB1. We compare SCRAs to traditional reference cannabinoids CP55,940, WIN55,212-2, and THC. The activity of the SCRAs was assessed in key receptor signalling and regulatory pathways, including cAMP production, translocation of ß-arrestin 1 and 2, and receptor internalisation. The activity profiles of the ligands were also evaluated using operational analysis to identify ligand bias. Results revealed that SCRAs activities were relatively balanced in the pathways evaluated (compared to WIN55,212-2), although 5F-CUMYL-P7AICA and XLR-11 possessed partial efficacy in cAMP stimulation and ß-arrestin translocation. Notably, the SCRAs showed distinct potency and efficacy profiles compared to THC. In particular, while the majority of SCRAs demonstrated robust ß-arrestin translocation, cAMP stimulation, and internalisation, THC failed to elicit high efficacy responses in any of these assays. Further study is required to delineate if these pathways could contribute to SCRA toxicity in humans.


Assuntos
Agonistas de Receptores de Canabinoides/farmacologia , Canabinoides/farmacologia , Drogas Desenhadas/farmacologia , Indóis/farmacologia , Receptor CB1 de Canabinoide/metabolismo , Receptor CB2 de Canabinoide/metabolismo , Agonistas de Receptores de Canabinoides/química , Agonistas de Receptores de Canabinoides/metabolismo , Canabinoides/química , Canabinoides/metabolismo , AMP Cíclico , Drogas Desenhadas/química , Drogas Desenhadas/metabolismo , Relação Dose-Resposta a Droga , Células HEK293 , Humanos , Indóis/química , Indóis/metabolismo , Ligantes , Transporte Proteico , Receptor CB1 de Canabinoide/genética , Receptor CB2 de Canabinoide/genética , Transdução de Sinais , Transfecção , beta-Arrestinas/metabolismo
15.
JACC CardioOncol ; 2(5): 721-731, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33511355

RESUMO

BACKGROUND: Atrial fibrillation (AF) during high-dose melphalan and autologous stem-cell transplantation (HDM/SCT) for light-chain (AL) amyloidosis confers significant morbidity. Traditional risk factors provide limited prediction for development of paroxysmal AF during this vulnerable period. OBJECTIVES: We sought to assess the association of clinical and echocardiographic parameters, including left atrial (LA) mechanics and development of AF in patients undergoing HDM/SCT therapy. METHODS: Baseline echocardiograms, electrocardiograms, and electronic medical records were retrospectively assessed among patients with AL amyloidosis before HDM/SCT (n = 91). LA function analysis was performed using speckle-tracking echocardiography. RESULTS: In this study, 42 patients (46%) had cardiac involvement; in the peri-transplant period, 12 (13%) developed AF (7 with cardiac involvement). No significant differences in age, sex, cardiac biomarkers, or cardiac risk factors were seen between patients with and without development of AF; one-third of patients with AF peri-transplant had previous AF. Although LA reservoir strain was reduced in patients with development of AF, time to peak strain rate indexed to R-R interval (TPSRI) (p = 0.001) was prolonged in patients with development of AF compared with sinus rhythm patients in the total cohort but also in subgroups with and without cardiac involvement. CONCLUSIONS: TPSRI, a parameter of mechanical dispersion in the early reservoir phase of LA function, is associated with development of AF among patients undergoing HDM/SCT for AL amyloidosis. These findings require validation in larger prospective cohorts.

16.
ACS Chem Neurosci ; 10(10): 4350-4360, 2019 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-31513380

RESUMO

Recreational consumption of synthetic cannabinoid receptor agonists (SCRAs) is a growing crisis in public health in many parts of the world. AMB-FUBINACA is a member of this class of drugs and is responsible for a large proportion of SCRA-related toxicity both in New Zealand and internationally. Strikingly, little is currently known about the mechanisms by which SCRAs exert toxic effects or whether their activity through the CB1 cannabinoid receptor (the mediator of cannabinoid-related psychoactivity) is sufficient to explain clinical observations. The current study therefore set out to perform a basic molecular pharmacology characterization of AMB-FUBINACA (in comparison to traditional research cannabinoids CP55,940, WIN55,212-2, and Δ9-THC) in fundamental pathways of receptor activity, including cAMP inhibition, pERK activation, ability to drive CB1 internalization, and ability to induce translocation of ß-arrestins-1 and -2. Activity pathways were then compared by operational analysis to indicate whether AMB-FUBINACA may be a biased ligand. Results revealed that AMB-FUBINACA is highly efficacious and potent in all pathways assayed. However, surprisingly, bias analysis suggested that Δ9-THC, not AMB-FUBINACA, may be a biased ligand, with it being less active in both arrestin pathways than predicted by the activity of the other ligands tested. These data may help predict molecular characteristics of SCRAs. However, more research is required to determine whether these molecular effects manifest in toxicity at tissue/system level.


Assuntos
Agonistas de Receptores de Canabinoides/farmacologia , Indazóis/farmacologia , Transdução de Sinais/efeitos dos fármacos , Valina/análogos & derivados , AMP Cíclico/metabolismo , Células HEK293 , Humanos , Fosforilação/efeitos dos fármacos , Valina/farmacologia , beta-Arrestinas/metabolismo
17.
Eur Heart J Cardiovasc Imaging ; 20(7): 751-762, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31056681

RESUMO

AIMS: To evaluate effects of caffeine on quantitative myocardial perfusion by positron emission tomography (PET) and associated major adverse cardiovascular events (MACE). METHODS AND RESULTS: Serum caffeine was measured for all 6087 PETs with 328 positive results (5.4%). Paired caffeine positive/negative PETs (84 patients for dipyridamole with median caffeine 1.6 mg/L, and additional 25 volunteers for regadenoson with median caffeine 7.4 mg/L) were compared for quantitative perfusion. Multivariate regression analysis for associations among caffeine, clinical/imaging variables, predicted caffeine probability was performed. MACEs were followed up to 9 years after PETs. For caffeine vs. no caffeine, respectively, stress flow was 1.74 ± 0.55 vs. 2.14 ± 0.53 for dipyridamole and 1.82 ± 0.61 vs. 2.33 ± 0.49 mL/min/g for regadenoson, and coronary flow reserve (CFR) was 2.26 ± 0.67 vs. 2.67 ± 0.72 for dipyridamole and 1.84 ± 0.33 vs. 2.31 ± 0.41 for regadenoson (all P < 0.001). Subjects were reclassified from high-risk CFR ≤2.0 with caffeine to low-risk CFR >2.0 without caffeine in 66.7% and 80% of dipyridamole and regadenoson caffeine-no-caffeine pairs, respectively. While relative images showed no differences, caffeine significantly altered coronary flow capacity (CFC) to false negative and false positive severity in 2.1% and 5.5% of the 328 caffeine positives, respectively (0.1% and 0.3% of 6087 PETs) but without change in severity guided management in most patients (92.4% of 328 caffeine or 99.6% of total 6087 PETs). CONCLUSION: Even low serum caffeine levels reduce quantitative perfusion during vasodilatory stress with false positive or false negative results minimized by empathic instruction, CFC analysis or repeat PET after strict caffeine abstention for definitive individualized risk stratification and management.


Assuntos
Cafeína/sangue , Doenças Cardiovasculares/diagnóstico por imagem , Circulação Coronária/efeitos dos fármacos , Imagem de Perfusão do Miocárdio/métodos , Tomografia por Emissão de Pósitrons/métodos , Adenosina/farmacologia , Agonistas do Receptor A2 de Adenosina/farmacologia , Idoso , Cafeína/administração & dosagem , Doenças Cardiovasculares/fisiopatologia , Dipiridamol/farmacologia , Teste de Esforço , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Purinas/farmacologia , Pirazóis/farmacologia
18.
Biophys J ; 114(5): 1142-1152, 2018 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-29539400

RESUMO

Muscles have evolved to power a wide variety of movements. A protein component critical to varying power generation is the myosin isoform present in the muscle. However, how functional variation in muscle arises from myosin structure is not well understood. We studied the influence of the converter, a myosin structural region at the junction of the lever arm and catalytic domain, using Drosophila because its single myosin heavy chain gene expresses five alternative converter versions (11a-e). We created five transgenic fly lines, each forced to express one of the converter versions in their indirect flight muscle (IFM) fibers. Electron microscopy showed that the converter exchanges did not alter muscle ultrastructure. The four lines expressing converter versions (11b-e) other than the native IFM 11a converter displayed decreased flight ability. IFM fibers expressing converters normally found in the adult stage muscles generated up to 2.8-fold more power and displayed up to 2.2-fold faster muscle kinetics than fibers with converters found in the embryonic and larval stage muscles. Small changes to stretch-activated force generation only played a minor role in altering power output of IFM. Muscle apparent rate constants, derived from sinusoidal analysis of the chimeric converter fibers, showed a strong positive correlation between optimal muscle oscillation frequency and myosin attachment kinetics to actin, and an inverse correlation with detachment related cross-bridge kinetics. This suggests the myosin converter alters at least two rate constants of the cross-bridge cycle with changes to attachment and power stroke related kinetics having the most influence on setting muscle oscillatory power kinetics.


Assuntos
Músculos/fisiologia , Miosinas/química , Miosinas/metabolismo , Sequência de Aminoácidos , Animais , Drosophila melanogaster , Regulação da Expressão Gênica , Cinética , Modelos Moleculares , Movimento , Músculos/metabolismo , Miosinas/genética , Domínios Proteicos
19.
Artigo em Inglês | MEDLINE | ID: mdl-28213449

RESUMO

BACKGROUND: Different adenosine stress imaging protocols have not been systemically validated for absolute myocardial perfusion and coronary flow reserve (CFR) by positron emission tomography, where submaximal stress precludes assessing physiological severity of coronary artery disease. METHODS AND RESULTS: In 127 volunteers, serial rest-stress positron emission tomography scans using rubidium-82 with various adenosine infusion protocols identified (1) the protocol with maximum stress perfusion and CFR, (2) test-retest precision in same subject, (3) stress perfusion and CFR after adenosine compared with dipyridamole, (4) heterogeneity of coronary flow capacity combining stress perfusion and CFR, and (5) potential relevance for patients with risk factors or coronary artery disease. The adenosine 6-minute infusion with rubidium-82 injection at 3 minutes caused CFR that was significantly 15.7% higher than the 4-minute adenosine infusion with rubidium-82 injection at 2 minutes and significantly more homogeneous by Kolmogorov-Smirnov analysis for histograms of 1344 pixel range of perfusion in paired positron emission tomographies. In a coronary artery disease cohort separate from volunteers of this study, compared with the 3/6-minute protocol, the 2/4-minute adenosine protocol would potentially have changed 332 of 1732 (19%) positron emission tomographies at low-risk physiological severity CFR ≥2.3 to CFR <2.0, thereby implying high-risk quantitative severity potentially appropriate for interventions but because of suboptimal stress of the 2/4 protocol in some patients. CONCLUSIONS: The 6-minute adenosine infusion with rubidium-82 activation at 3 minutes produced CFR that averaged 15.7% higher than that in the 2/4-minute protocol, thereby potentially providing essential information for personalized management in some patients.


Assuntos
Adenosina/administração & dosagem , Doença da Artéria Coronariana/diagnóstico por imagem , Vasos Coronários/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Imagem de Perfusão do Miocárdio/métodos , Tomografia por Emissão de Pósitrons , Vasodilatadores/administração & dosagem , Velocidade do Fluxo Sanguíneo , Estudos de Casos e Controles , Doença da Artéria Coronariana/fisiopatologia , Doença da Artéria Coronariana/terapia , Vasos Coronários/fisiopatologia , Dipiridamol/administração & dosagem , Feminino , Reserva Fracionada de Fluxo Miocárdico , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Compostos Radiofarmacêuticos/administração & dosagem , Reprodutibilidade dos Testes , Radioisótopos de Rubídio/administração & dosagem , Estatísticas não Paramétricas , Fatores de Tempo
20.
Bioorg Med Chem Lett ; 26(2): 466-471, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26687487

RESUMO

Poor solubility and cationic amphiphilic drug-likeness were liabilities identified for a lead series of S1P3-sparing, S1P1 agonists originally developed from a high-throughput screening campaign. This work describes the subsequent optimization of these leads by balancing potency, selectivity, solubility and overall molecular charge. Focused SAR studies revealed favorable structural modifications that, when combined, produced compounds with overall balanced profiles. The low brain exposure observed in rat suggests that these compounds would be best suited for the potential treatment of peripheral autoimmune disorders.


Assuntos
Oxidiazóis/farmacologia , Receptores de Lisoesfingolipídeo/agonistas , Tiadiazóis/farmacologia , Animais , Encéfalo/metabolismo , Ácido Glutâmico/metabolismo , Células Hep G2 , Humanos , Ligação de Hidrogênio , Cinética , Oxidiazóis/sangue , Oxidiazóis/síntese química , Ratos , Solubilidade , Relação Estrutura-Atividade , Tiadiazóis/sangue , Tiadiazóis/síntese química
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