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1.
Heliyon ; 10(3): e24849, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38317990

RESUMO

Whether receptor activity-modifying proteins (RAMPs) play a key role in human cancer prognosis and immunity remains unknown. We used data from the public databases, The Cancer Genome Atlas, Therapeutically Applicable Research to Generate Effective Treatments, and the Genotype-Tissue Expression project. We utilized bioinformatics methods, R software, and a variety of online databases to analyze RAMPs. In general, RAMPs were significantly and differentially expressed in multiple tumors, and RAMP expression was closely associated with prognosis, immune checkpoints, RNA-editing genes, tumor mutational burden, microsatellite instability, ploidy, and stemness indices. In addition, the expression of RAMPs is strongly correlated with tumor-infiltrating lymphocytes in human cancers. Moreover, the RAMP co-expression network is largely involved in many immune-related biological processes. Quantitative reverse transcription polymerase chain reaction and Western blot proved that RAMP3 was highly expressed in glioma, and RAMP3 promoted tumor proliferation and migration. RAMPs exhibit potential as prognostic and immune-related biomarkers in human cancers. Moreover, RAMPs can be potentially developed as therapeutic targets or used to enhance the efficacy of immunotherapy.

2.
Updates Surg ; 75(6): 1533-1540, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37458902

RESUMO

Careful preoperative planning is key in minimally invasive radical antegrade modular pancreatosplenectomy (MI-RAMPS). This retrospective study aims to show the practical implications of computed tomography distance between the right margin of the tumor and either the left margin of the spleno-mesenteric confluence (d-SMC) or the gastroduodenal artery (d-GDA). Between January 2011 and June 2022, 48 minimally invasive RAMPS were performed for either pancreatic cancer or malignant intraductal mucinous papillary neoplasms. Two procedures were converted to open surgery (4.3%). Mean tumor size was 31.1 ± 14.7 mm. Mean d-SMC was 21.5 ± 18.5 mm. Mean d-GDA was 41.2 ± 23.2 mm. A vein resection was performed in 10 patients (20.8%) and the pancreatic neck could not be divided by an endoscopic stapler in 19 operations (43.1%). In patients requiring a vein resection, mean d-SMC was 10 mm (1.5-15.5) compared to 18 mm (10-37) in those without vein resection (p = 0.01). The cut-off of d-SMC to perform a vein resection was 17 mm (AUC 0.75). Mean d-GDA was 26 mm (19-39) mm when an endoscopic stapler could not be used to divide the pancreas, and 46 mm (30-65) when the neck of the pancreas was stapled (p = 0.01). The cut-off of d-GDA to safely pass an endoscopic stapler behind the neck of the pancreas was 43 mm (AUC 0.75). Computed tomography d-SMC and d-GDA are key measurements when planning for MI-RAMPS.


Assuntos
Laparoscopia , Neoplasias Pancreáticas , Humanos , Pancreatectomia/métodos , Estudos Retrospectivos , Esplenectomia/métodos , Neoplasias Pancreáticas/cirurgia , Neoplasias Pancreáticas/patologia , Pâncreas/cirurgia , Laparoscopia/métodos
3.
Environ Sci Technol ; 57(23): 8628-8637, 2023 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-37254500

RESUMO

Reactive oxygen species (ROS) play key roles in driving biogeochemical processes. Recent studies have revealed nonphotochemical electron transfer from redox-active substances (e.g., iron minerals) to oxygen as a new route for ROS production. Yet, naturally occurring iron minerals mainly exist in thermodynamically stable forms, restraining their potential for driving ROS production. Here, we report that tide-induced redox oscillations can activate thermodynamically stable iron minerals for enhanced ROS production. •OH production in intertidal soils (15.8 ± 0.5 µmol/m2) was found to be 5.9-fold more efficient than those in supratidal soils. Moreover, incubation of supratidal soils under tidal redox fluctuations dramatically enhanced •OH production by 4.3-fold. The tidal hydrology triggered redox alternation between biotic reduction and abiotic oxidation and could accelerate the production of reactive ferrous ions and amorphous ferric oxyhydroxides, making thermodynamically stable iron minerals into redox-active metastable iron phases (RAMPs) with reduced crystallinity and promoting surface electrochemical activities. Those RAMPs displayed enhanced redox activity for ROS production. Investigations of nationwide coastal soils verified that tide-induced redox oscillations could ubiquitously activate soils for enhanced ROS production. Our study demonstrates the effective formation of RAMPs from redox oscillations by hydrological perturbations, which provides new insights into natural ROS sources.


Assuntos
Ferro , Minerais , Ferro/química , Espécies Reativas de Oxigênio , Minerais/química , Compostos Férricos , Oxirredução , Solo
4.
J Biol Chem ; 299(5): 104664, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37003505

RESUMO

Cholestatic itch is a severe and debilitating symptom in liver diseases with limited treatment options. The class A G protein-coupled receptor (GPCR) Mas-related GPCR subtype X4 (MRGPRX4) has been identified as a receptor for bile acids, which are potential cholestatic pruritogens. An increasing number of GPCRs have been shown to interact with receptor activity-modifying proteins (RAMPs), which can modulate different aspects of GPCR biology. Using a combination of multiplexed immunoassay and proximity ligation assay, we show that MRGPRX4 interacts with RAMPs. The interaction of MRGPRX4 with RAMP2, but not RAMP1 or 3, causes attenuation of basal and agonist-dependent signaling, which correlates with a decrease of MRGPRX4 cell surface expression as measured using a quantitative NanoBRET pulse-chase assay. Finally, we use AlphaFold Multimer to predict the structure of the MRGPRX4-RAMP2 complex. The discovery that RAMP2 regulates MRGPRX4 may have direct implications for future drug development for cholestatic itch.


Assuntos
Prurido , Proteínas Modificadoras da Atividade de Receptores , Receptores Acoplados a Proteínas G , Membrana Celular/metabolismo , Proteína 1 Modificadora da Atividade de Receptores/metabolismo , Proteína 2 Modificadora da Atividade de Receptores/metabolismo , Proteína 3 Modificadora da Atividade de Receptores/metabolismo , Proteínas Modificadoras da Atividade de Receptores/química , Proteínas Modificadoras da Atividade de Receptores/metabolismo , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais , Prurido/metabolismo , Ligação Proteica , Humanos
5.
MethodsX ; 10: 102142, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37007621

RESUMO

Capillary Dynamic Light Scattering (DLS), has recently been introduced as a simple and enabling technique that increases the measurement range of traditional DLS analysis with minimized sample volumes (Ruseva et al., 2018). The previously published protocol for the preparation of samples for analysis within a capillary called for sealing of the capillary end using a clay compound (Ruseva et al., 2019). This material is not, however, compatible with organic solvents, nor with elevated sample temperatures. To extend the uses of capillary DLS to more complex assays like thermal aggregation studies, a new sealing method is demonstrated using a UV curing compound. This further motivates the use of capillary DLS to minimize volumes of destroyed precious samples in pharmaceutical development assays to study thermal kinetics.•Use of UV curing compound to seal capillaries used in DLS to preserve low volumes of sample.

6.
Accid Anal Prev ; 183: 106970, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36669457

RESUMO

This paper proposes an iterative learning control framework for lane changing to improve traffic operation and safety at a diverging area nearby a highway off-ramp in an environment with connected and automated vehicles (CAVs). This framework controls CAVs in the off-ramp bottlenecks by imitating the trajectories optimized by machine learning algorithms. Next Generation Simulation (NGSIM) dataset is utilized as the raw data and filtered by cost function. The traffic models, including lane-changing decision (LCD) models and lane-changing execution (LCE) models, are completed by Random Forest (RF) and Back Propagation Neural Network (BPNN) algorithms. Based on simulation results, simulation data satisfying the predetermined criterion will be added to dataset in the next iteration. Various metrics are considered to evaluate the proposed framework systematically from both lateral and longitudinal aspects, including time exposed time-to collision (TET), time integrated time-to-collision (TIT), rear-end collision risk indexes (RCRI) and lane-changing risk index (LCRI). The results present that the iterative framework can decrease the longitudinal risk of the system by a factor of two times, and can reduce the lateral risk by 28.7%. When the CAVs market penetration rate (MPR) reaches 100%, the longitudinal and lateral risk values of the off-ramp system can be reduced by 90% and 35%, respectively. However, it is worth noting that only when the CAVs MPR reaches 50% does the system's value at risk change significantly.


Assuntos
Acidentes de Trânsito , Condução de Veículo , Humanos , Acidentes de Trânsito/prevenção & controle , Algoritmos , Simulação por Computador , Aprendizado de Máquina , Segurança
7.
Chinese Journal of Biologicals ; (12): 626-630, 2023.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-996381

RESUMO

@#Receptor activity-modifying proteins(RAMPs) are type I transmembrane proteins,which are activity-modifying proteins of a variety of G-protein-coupled receptors(GPCRs).RAMPs are related to physiological and pathological phenomena such as neurological diseases,cardiovascular diseases,renal function,skeletal development and obesity,and of great significance for disease prevention,which are potential targets for the treatment of various diseases and also closely related to the prognosis of diseases.At present,there are few studies on proteins that may regulate the expression of RAMPs.This paper focuses on the sterol regulatory element-binding factor-2(SREBF-2) that may regulate the transcription and expression of RAMP3, and reviews the research progress of RAMPs in biology,pathology and pharmacology,providing a reference for the further research on RAMPs and the prevention and detection of related diseases.

8.
Clin Toxicol (Phila) ; 60(12): 1309-1317, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36301078

RESUMO

INTRODUCTION: The Veratrum genus is composed of plants containing a diverse set of steroidal alkaloids. Veratrum plant material has been utilized for centuries as herbal medicines, however the alkaloids have such a low therapeutic index that they are not used in modern medicine. Here we report an incident of inadvertent ingestion of V. parviflorum by hikers in Georgia that allowed detection, and in several instances identification of alkaloids from the plant, and correlated their presence within patient blood and breast milk specimens. CASE HISTORY: Eight patients, three male and five female, presented in the spring of 2020 and 2021 with symptoms requiring emergent medical attention after ingestion of Veratrum parviflorum. All patients believed the plants to be a local native species of wild leek, Allium tricoccum, locally known as ramps. Plants were identified using photographs as well as fresh and cooked plant material provided by patients, in consultation with botanists at the University of Georgia Herbarium. Written consent was obtained from all patients for collection of blood and breast milk specimens for laboratory identification of Veratrum alkaloids. METHODS: V. parviflorum plant material, and patient serum and breast milk were analyzed by high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-QTOF) to identify steroidal alkaloids. RESULTS: The V. parviflorum extract was confirmed to contain cyclopamine, veratramine, jervine, and muldamine. Two out of the eight patients had detectable concentrations of Veratrum alkaloids. Of the alkaloids identified in the plant, cyclopamine and jervine were detected within patient serum, and cyclopamine and veratramine were observed to be present in breast milk. DISCUSSION: Toxicity resulting from Veratrum steroidal alkaloids has primarily been reported from V. album and V. viride. This is the second report of V. parviflorum poisoning. The present work reports for the first time the presence of muldamine and jervine within V. parviflorum. This work provides the first instance of identification of Veratrum alkaloids in breast milk. Thus, the findings presented herein add to literature record causative agents contributing to the toxicity of V. parviflorum when ingested and potential for secondary poisoning through breastfeeding. CONCLUSION: V. parviflorum toxicity was observed to cause nausea, vomiting, hypotension, bradycardia, abdominal pain, light-headedness, blurred vision, and tingling in the arms. Patients experiencing mild symptoms improved with supportive care, IV fluids, and antiemetics, but hemodynamically unstable patients required atropine and vasopressors. This study demonstrated that more lipophilic Veratrum alkaloids can be passed along in breast milk, which suggests additional precautions may be critical to limit further poisonings.


Assuntos
Alcaloides , Intoxicação por Plantas , Veratrum , Feminino , Humanos , Leite Humano , Alcaloides de Veratrum , Intoxicação por Plantas/tratamento farmacológico
9.
Front Surg ; 9: 981591, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36117824

RESUMO

Background: Laparoscopic radical antegrade modular pancreatosplenectomy (LRAMPS) is a validated surgical treatment for patients with left-sided pancreatic ductal adenocarcinoma (PDAC). In addition, laparoscopic distal pancreatectomy (LDPS) has purported benefits. However, there is a limited analysis comparing the results between LRAMPS and LDPS. Thus, this study aims to compare the short-term and long-term outcomes of patients who underwent LRAMPS and LDPS for PDAC treatment. Methods: Patients with left-sided PDAC that underwent LRAMPS or LDPS from 2015 to 2021 were retrospectively identified. Demographic and clinic pathologic data were collected. Disease-free survival (DFS) and overall survival (OS) probabilities were obtained. Results: The number of lymph nodes retrieved was significantly greater in the LRAMPS group than in the LDPS group. Several clinicopathological factors, including CA19-9 levels greater than 37 U/ml, positive lymph nodes, moderate to poor tumor differentiation, and peripancreas fat invasion, were associated with DFS. Moderate with poor tumor differentiation was associated with poor DFS (HR 0.568; 95% CI 0.373-0.921; P = 0.021). Levels of CA19-9 greater than 37 U/ml, CEA levels greater than 5 µg/ml, larger tumor size, positive lymph nodes, moderate with poor tumor differentiation, peripancreas fat invasion, and adjuvant chemotherapy were all associated with OS. LRAMPS nearly improved OS but did not reach statistical significance. Serum carcinoembryonic antigen (CEA) levels greater than 5 ug/ml (HR 1.693; 95% CI 1.200-1.132; P = 0.001), and positive lymph nodes (HR 2.410; 95% CI 1.453-3.995; P = 0.001) were independently associated with poor OS. Treatment with adjuvant chemotherapy was associated with improved OS (HR 0.491; 95% CI 0.248-0.708; P = 0.001). Conclusions: The LRAMPS procedure achieved comparable results to standard LDPS in terms of postoperative outcomes. Treatment with chemotherapy is important for the prognosis of patients with left-sided pancreatic cancer.

10.
Wilderness Environ Med ; 33(3): 340-343, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35691768

RESUMO

Allium tricoccum (commonly known as "ramps") is an edible plant known for its strong garlic-like odor and onion flavor. Unfortunately, A tricoccum mimics such as Lily of the Valley (Convallaria majalis) and False Hellebore (Veratrum viride) can lead to foraging errors and subsequent patient harm/toxicity. We describe 3 adults who foraged and ate what they believed were A tricoccum and then subsequently became symptomatic with detectable digoxin concentrations. A 41-y-old woman, 41-y-old man, and a 31-y-old man presented to the emergency department after ingesting an unknown plant that was believed to be A tricoccum. On arrival to the emergency department, the patients were hypotensive and bradycardic. They had detectable digoxin concentrations ranging from 0.08 ng·mL-1 to 0.13 ng·mL-1. One patient received 20 vials of digoxin antibody fragments. All 3 patients recovered without complication. Laboratory analysis of plant specimen was positive for cyclopamine, a teratogenic alkaloid found in Veratrum californicum. A tricoccum foraging errors can be a source of morbidity given their similarity in appearance to plants like C majalis and V viride. C majalis causes a detectable digoxin concentration via its cardiac steroid compound (convallatoxin) that is similar to digoxin. V viride contains alkaloid compounds (such as veratridine) that can cross react with digoxin assays and lead to a falsely elevated digoxin concentration. Clinicians should be prompted to think about ingestion of C majalis or Veratrum spp. when patients present with bradycardia, gastrointestinal symptoms, and detectable digoxin concentrations after plant ingestion and/or foraging for A tricoccum.


Assuntos
Gastroenteropatias , Veratrum , Adulto , Digoxina , Feminino , Humanos , Fragmentos de Imunoglobulinas , Masculino , Veratridina
11.
Front Cell Infect Microbiol ; 12: 812848, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35651757

RESUMO

Detection and transduction of environmental signals, constitute a prerequisite for successful parasite invasion; i.e., Leishmania transmission, survival, pathogenesis and disease manifestation and dissemination, with diverse molecules functioning as inter-cellular signaling ligands. Receptors [i.e., G protein-coupled receptors (GPCRs)] and their associated transduction mechanisms, well conserved through evolution, specialize in this function. However, canonical GPCR-related signal transduction systems have not been described in Leishmania, although orthologs, with reduced domains and function, have been identified in Trypanosomatidae. These inter-cellular communication means seem to be essential for multicellular and unicellular organism's survival. GPCRs are flexible in their molecular architecture and may interact with the so-called receptor activity-modifying proteins (RAMPs), which modulate their function, changing GPCRs pharmacology, acting as chaperones and regulating signaling and/or trafficking in a receptor-dependent manner. In the skin, vasoactive- and neuro- peptides released in response to the noxious stimuli represented by the insect bite may trigger parasite physiological responses, for example, chemotaxis. For instance, in Leishmania (V.) braziliensis, sensory [Substance P, SP, chemoattractant] and autonomic [Vasoactive Intestinal Peptide, VIP, and Neuropeptide Y, NPY, chemorepellent] neuropeptides at physiological levels stimulate in vitro effects on parasite taxis. VIP and NPY chemotactic effects are impaired by their corresponding receptor antagonists, suggesting that the stimulated responses might be mediated by putative GPCRs (with essential conserved receptor domains); the effect of SP is blocked by [(D-Pro 2, D-Trp7,9]-Substance P (10-6 M)] suggesting that it might be mediated by neurokinin-1 transmembrane receptors. Additionally, vasoactive molecules like Calcitonin Gene-Related Peptide [CGRP] and Adrenomedullin [AM], exert a chemorepellent effect and increase the expression of a 24 kDa band recognized in western blot analysis by (human-)-RAMP-2 antibodies. In-silico search oriented towards GPCRs-like receptors and signaling cascades detected a RAMP-2-aligned sequence corresponding to Leishmania folylpolyglutamate synthase and a RAMP-3 aligned protein, a hypothetical Leishmania protein with yet unknown function, suggesting that in Leishmania, CGRP and AM activities may be modulated by RAMP- (-2) and (-3) homologs. The possible presence of proteins and molecules potentially involved in GPCRs cascades, i.e., RAMPs, signpost conservation of ancient signaling systems associated with responses, fundamental for cell survival, (i.e., taxis and migration) and may constitute an open field for description of pharmacophores against Leishmania parasites.


Assuntos
Peptídeo Relacionado com Gene de Calcitonina , Leishmania , Peptídeo Relacionado com Gene de Calcitonina/farmacologia , Comunicação Celular , Humanos , Leishmania/metabolismo , Proteínas Modificadoras da Atividade de Receptores/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Substância P/farmacologia
12.
Int J Surg ; 103: 106676, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35577311

RESUMO

BACKGROUND: Laparoscopic radical antegrade modular pancreatosplenectomy (l-RAMPS) provides a new surgical approach for patients with pancreatic cancers of the body and tail. However, whether it can achieve comparable outcomes to the open RAMPS (o-RAMPS) remains an issue. METHODS: To evaluate the safety and effectiveness of l-RAMPS, the studies in the databases of Medline, Embase, and the Cochrane Library published before September 13, 2021 were searched and a meta-analysis was performed using the 2020 Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline. The perioperative and oncological outcomes were analyzed. RESULTS: Five retrospective cohorts involving 189 patients were included for final pooled analysis. There were no significant differences in the patients' operation time, intra-abdominal bleeding rate, intra-abdominal infection rate, mild morbidity (Clavien-Dindo classification = 1), moderate to severe morbidity (Clavien-Dindo classification ≥2), overall morbidity, wound infection rate, pancreatic fistula rate, delayed gastric emptying rate, reoperation rate, length of hospital stay, postoperative mortality, R0 resection rate, and 2-year overall survival between the 2 approaches. Besides, l-RAMPS was associated with less blood loss (mean difference (MD) = -232.69, 95% confidence interval (CI) = -316.93 to -148.46, P < 0.00001) and shorter days until oral feeding (MD = -0.79, 95% CI = -1.35 to -0.22, P = 0.006). However, the pooled analysis also indicated a significantly fewer lymph nodes dissected (MD = -3.01, 95% CI = -5.59 to -0.43, P = 0.02) in l-RAMPS approach. CONCLUSIONS: Although l-RAMPS provides similar outcomes associated with benefits of minimal invasiveness compared to o-RAMPS, it harvested significantly fewer lymph nodes which might have potentially negative influence on the patients' long-term survival. L-RAMPS is still in the infancy stage and further investigation is needed to verify its feasibility.


Assuntos
Laparoscopia , Neoplasias Pancreáticas , Humanos , Laparoscopia/efeitos adversos , Excisão de Linfonodo , Pancreatectomia/efeitos adversos , Estudos Retrospectivos , Esplenectomia , Neoplasias Pancreáticas
13.
Front Physiol ; 13: 840763, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35422711

RESUMO

Signalling of the calcitonin-like receptor (CLR) is multifaceted, due to its interaction with receptor activity modifying proteins (RAMPs), and three endogenous peptide agonists. Previous studies have focused on the bias of G protein signalling mediated by the receptor and receptor internalisation of the CLR-RAMP complex has been assumed to follow the same pattern as other Class B1 G Protein-Coupled Receptors (GPCRs). Here we sought to measure desensitisation of the three CLR-RAMP complexes in response to the three peptide agonists, through the measurement of ß-arrestin recruitment and internalisation. We then delved further into the mechanism of desensitisation through modulation of ß-arrestin activity and the expression of GPCR kinases (GRKs), a key component of homologous GPCR desensitisation. First, we have shown that CLR-RAMP1 is capable of potently recruiting ß-arrestin1 and 2, subsequently undergoing rapid endocytosis, and that CLR-RAMP2 and -RAMP3 also utilise these pathways, although to a lesser extent. Following this we have shown that agonist-dependent internalisation of CLR is ß-arrestin dependent, but not required for full agonism. Overexpression of GRK2-6 was then found to decrease receptor signalling, due to an agonist-independent reduction in surface expression of the CLR-RAMP complex. These results represent the first systematic analysis of the importance of ß-arrestins and GRKs in CLR-RAMP signal transduction and pave the way for further investigation regarding other Class B1 GPCRs.

14.
Cancer Diagn Progn ; 2(2): 144-149, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35399180

RESUMO

Distal pancreatectomy with splenectomy is the gold-standard surgery for the treatment of left-sided pancreatic cancer. Margin negative resection accompanied by effective lymphadenectomy are the deciding factors affecting the outcome of tail-body pancreatic adenocarcinoma. Radical antegrade modular pancreatosplenectomy (RAMPS) is considered as a reasonable approach for margin-negative and systemic lymph node clearance. Herein, we aim to present all existing data regarding this novel approach including surgical technique and comparison with standardized procedures. RAMPS has shown oncological superiority comparing to distal pancreatectomy with splenectomy due to radical lymphadenectomy and improved dissection of the posterior pancreatic aspects. Robotic-assisted RAMPS has recently been described as a valuable alternative to open RAMPS. With this novel technique, anterior, posterior or modified approaches can be achieved; favorable clinical and oncological outcomes have been reported in the current literature, with reduced conversion rates compared to other minimally invasive approaches, as well as vastly improved maneuverability, accuracy and vision. Robotic-assisted RAMPS is not only technically feasible but also oncologically safe in cases of well-selected, left-sided pancreatic cancer.

15.
Curr Biol ; 32(5): 1077-1087.e9, 2022 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-35114098

RESUMO

Reinforcement learning models of the basal ganglia map the phasic dopamine signal to reward prediction errors (RPEs). Conventional models assert that, when a stimulus predicts a reward with fixed delay, dopamine activity during the delay should converge to baseline through learning. However, recent studies have found that dopamine ramps up before reward in certain conditions even after learning, thus challenging the conventional models. In this work, we show that sensory feedback causes an unbiased learner to produce RPE ramps. Our model predicts that when feedback gradually decreases during a trial, dopamine activity should resemble a "bump," whose ramp-up phase should, furthermore, be greater than that of conditions where the feedback stays high. We trained mice on a virtual navigation task with varying brightness, and both predictions were empirically observed. In sum, our theoretical and experimental results reconcile the seemingly conflicting data on dopamine behaviors under the RPE hypothesis.


Assuntos
Dopamina , Recompensa , Animais , Aprendizagem , Camundongos , Reforço Psicológico , Incerteza
16.
Br J Pharmacol ; 179(3): 371-380, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34411289

RESUMO

Migraine is one of the most common of neurological disorders with a global prevalence of up to 15%. One in five migraineurs have frequent episodic or chronic migraine requiring prophylactic treatment. In recent years, specific pharmacological treatments targeting calcitonin gene-related peptide (CGRP) signalling molecules have provided safe and effective treatments, monoclonal antibodies for prophylaxis and gepants for acute therapy. Albeit beneficial, it is important to understand the molecular mechanisms of these new drugs to better understand migraine pathophysiology and improve therapy. Here, we describe current views on the role of the CGRP family of peptides - CGRP, calcitonin, adrenomedullin, amylin - and their receptors in the trigeminovascular system. All these molecules are present within the trigeminovascular system but differ in expression and localization. It is likely that they have different roles, which can be utilized in providing additional drug targets. LINKED ARTICLES: This article is part of a themed issue on Advances in Migraine and Headache Therapy (BJP 75th Anniversary). To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.3/issuetoc.


Assuntos
Peptídeo Relacionado com Gene de Calcitonina , Transtornos de Enxaqueca , Calcitonina , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Antagonistas do Receptor do Peptídeo Relacionado ao Gene de Calcitonina/farmacologia , Antagonistas do Receptor do Peptídeo Relacionado ao Gene de Calcitonina/uso terapêutico , Humanos , Transtornos de Enxaqueca/tratamento farmacológico , Receptores de Peptídeo Relacionado com o Gene de Calcitonina/metabolismo
17.
J R Soc Interface ; 18(184): 20210648, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34814729

RESUMO

We present methods for building a Java Runtime-Alterable-Model Platform (RAMP) of complex dynamical systems. We illustrate our methods by building a multivariant SEIR (epidemic) RAMP. Underlying our RAMP is an individual-based model that includes adaptive contact rates, pathogen genetic drift, waning and cross-immunity. Besides allowing parameter values, process descriptions and scriptable runtime drivers to be easily modified during simulations, our RAMP can used within R-Studio and other computational platforms. Process descriptions that can be runtime altered within our SEIR RAMP include pathogen variant-dependent host shedding, environmental persistence, host transmission and within-host pathogen mutation and replication. They also include adaptive social distancing and adaptive application of vaccination rates and variant-valency of vaccines. We present simulation results using parameter values and process descriptions relevant to the current COVID-19 pandemic. Our results suggest that if waning immunity outpaces vaccination rates, then vaccination rollouts may fail to contain the most transmissible variants, particularly if vaccine valencies are not adapted to deal with escape mutations. Our SEIR RAMP is designed for easy use by others. More generally, our RAMP concept facilitates construction of highly flexible complex systems models of all types, which can then be easily shared as stand-alone application programs.


Assuntos
COVID-19 , Deriva Genética , Humanos , Pandemias , SARS-CoV-2 , Vacinação
18.
J Leukoc Biol ; 110(6): 1023-1031, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34643294

RESUMO

The 78-kDa glucose-regulated protein (GRP78) has extracellular, anti-inflammatory properties that can aid resolving inflammation. It has been established previously that GRP78 induced myeloid CD11c+ cell differentiation into distinct tolerogenic cells. This tolerance induction makes GRP78 a potential therapeutic agent for transplanted allogeneic grafts and autoimmune diseases, such as type 1 diabetes. In this research, it is revealed that rmGRP78-treated NOD mice bone marrow-derived CD11c+ cells (GRP78-DCs) highly expressed B7-H4 but down-regulated CD86 and CD40, and retained a tolerogenic signature even after stimulation by LPS. In the assessment of in vivo therapeutic efficacy after the adoptive transfer of GRP78-DCs into NOD mice, fluorescent imaging analyses revealed that the transfer specifically homed in inflamed pancreases, promoting ß-cell survival and alleviating insulitis in NOD mice. The adoptive transfer of GRP78-DCs also helped reduce Th1, Th17, and CTL, suppressing inflammatory cytokine production in vivo. The findings suggest that adoptive GRP78-DC transfer is critical to resolving inflammation in NOD mice and may have relevance in a clinical setting.


Assuntos
Células Dendríticas/transplante , Diabetes Mellitus Tipo 1/imunologia , Chaperona BiP do Retículo Endoplasmático , Tolerância Imunológica/imunologia , Ilhotas Pancreáticas , Transferência Adotiva , Animais , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/imunologia , Células Dendríticas/imunologia , Chaperona BiP do Retículo Endoplasmático/imunologia , Chaperona BiP do Retículo Endoplasmático/metabolismo , Chaperona BiP do Retículo Endoplasmático/farmacologia , Feminino , Ilhotas Pancreáticas/imunologia , Ilhotas Pancreáticas/patologia , Camundongos , Camundongos Endogâmicos NOD , Pancreatite/imunologia
19.
Biomedicines ; 9(10)2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34680407

RESUMO

Radical antegrade modular pancreatosplenectomy (RAMPS) is considered an effective procedure for left-sided pancreatic ductal adenocarcinoma (PDAC). However, whether there are differences in perioperative outcomes, pathologies, or survival outcomes between anterior RAMPS (aRAMPS) and posterior RAMPS (pRAMPS) has not been reported previously. We retrospectively reviewed and compared the demographic, perioperative, histopathologic, and survival data of patients who underwent aRAMPS or pRAMPS for PDAC. We also compared these two groups among patients without periadrenal infiltration or adrenal invasion. A total of 112 aRAMPS patients and 224 pRAMPS patients were evaluated. Periadrenal infiltration, neoadjuvant treatment, and concurrent vessel resection were more prevalent in the pRAMPS group. After excluding patients with periadrenal infiltration, 106 aRAMPS patients were compared with 157 pRAMPS patients. There were no significant differences between the aRAMPS and pRAMPS groups in the pathologic tumor size, resection margin, proportion of tangential margin in the R1 resection, and number of harvested lymph nodes. The median overall survival and disease-free survival also did not differ significantly between the two groups. We cautiously suggest that pRAMPS will not necessarily provide more beneficial histopathologic outcomes and survival rates for left-sided PDAC cases without periadrenal infiltration. If periadrenal infiltration is not suspected, aRAMPS alone should be sufficiently effective.

20.
Accid Anal Prev ; 163: 106461, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34700250

RESUMO

The objective of this study was to evaluate the effects of geometric design on crash risk on freeway segments with closely spaced entrance and exit ramps. Traffic flow, geometric design features and crash data from 80 segments on 14 freeways in the state of California, United States were applied. A multilevel logistic regression model with cross-level interactions was developed, where traffic variables were put on the case level, and their estimated coefficients were defined as a function of geometric design variables on the segment level. A basic logistic model and a multilevel logistic model without cross-level interactions were developed for comparison. The result shows that the one with cross-level interactions provides the best goodness of fit. The results indicate that six categories of geometric design variables are significantly associated with crash risk, i.e. lane configuration, basic number of lanes, ramp spacing, theoretical gore, inner shoulder width and speed limit. All but one (inner should width) geometric design variables have significant interaction terms with traffic flow variables. The effects of geometric design variables on crash risk are not fixed but vary with traffic conditions. The findings of this study can provide design guidance to improve road safety of freeway segments with closely spaced entrance and exit ramps.


Assuntos
Condução de Veículo , Acidentes de Trânsito , Humanos , Modelos Logísticos , Análise Multinível , Estados Unidos
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