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Activity-dependent CREB phosphorylation and gene expression are critical for long-term neuronal plasticity. Local signaling at CaV1 channels triggers these events, but how information is relayed onward to the nucleus remains unclear. Here, we report a mechanism that mediates long-distance communication within cells: a shuttle that transports Ca(2+)/calmodulin from the surface membrane to the nucleus. We show that the shuttle protein is γCaMKII, its phosphorylation at Thr287 by ßCaMKII protects the Ca(2+)/CaM signal, and CaN triggers its nuclear translocation. Both ßCaMKII and CaN act in close proximity to CaV1 channels, supporting their dominance, whereas γCaMKII operates as a carrier, not as a kinase. Upon arrival within the nucleus, Ca(2+)/CaM activates CaMKK and its substrate CaMKIV, the CREB kinase. This mechanism resolves long-standing puzzles about CaM/CaMK-dependent signaling to the nucleus. The significance of the mechanism is emphasized by dysregulation of CaV1, γCaMKII, ßCaMKII, and CaN in multiple neuropsychiatric disorders.
Assuntos
Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Animais , Cálcio/metabolismo , Canais de Cálcio/metabolismo , Calmodulina/metabolismo , Núcleo Celular/metabolismo , Neurônios/metabolismo , Fosforilação , Ratos Sprague-Dawley , Transcrição GênicaRESUMO
Excitation-transcription coupling (E-TC) links synaptic and cellular activity to nuclear gene transcription. It is generally accepted that E-TC makes a crucial contribution to learning and memory through its role in underpinning long-lasting synaptic enhancement in late-phase long-term potentiation and has more recently been linked to late-phase long-term depression: both processes require de novo gene transcription, mRNA translation and protein synthesis. E-TC begins with the activation of glutamate-gated N-methyl-D-aspartate-type receptors and voltage-gated L-type Ca2+ channels at the membrane and culminates in the activation of transcription factors in the nucleus. These receptors and ion channels mediate E-TC through mechanisms that include long-range signalling from the synapse to the nucleus and local interactions within dendritic spines, among other possibilities. Growing experimental evidence links these E-TC mechanisms to late-phase long-term potentiation and learning and memory. These advances in our understanding of the molecular mechanisms of E-TC mean that future efforts can focus on understanding its mesoscale functions and how it regulates neuronal network activity and behaviour in physiological and pathological conditions.
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Plasticidade Neuronal , Receptores de N-Metil-D-Aspartato , Humanos , Receptores de N-Metil-D-Aspartato/metabolismo , Plasticidade Neuronal/fisiologia , Potenciação de Longa Duração/fisiologia , Neurônios/metabolismo , Sinapses/metabolismo , Expressão Gênica , Hipocampo/fisiologiaRESUMO
Here, we use single-molecule techniques to study the aggregation of α-synuclein, the protein whose misfolding and deposition is associated with Parkinson's disease. We identify a conformational change from the initially formed oligomers to stable, more compact proteinase-K-resistant oligomers as the key step that leads ultimately to fibril formation. The oligomers formed as a result of the structural conversion generate much higher levels of oxidative stress in rat primary neurons than do the oligomers formed initially, showing that they are more damaging to cells. The structural conversion is remarkably slow, indicating a high kinetic barrier for the conversion and suggesting that there is a significant period of time for the cellular protective machinery to operate and potentially for therapeutic intervention, prior to the onset of cellular damage. In the absence of added soluble protein, the assembly process is reversed and fibrils disaggregate to form stable oligomers, hence acting as a source of cytotoxic species.
Assuntos
alfa-Sinucleína/química , alfa-Sinucleína/metabolismo , Animais , Células Cultivadas , Endopeptidase K/metabolismo , Transferência Ressonante de Energia de Fluorescência , Humanos , Cinética , Modelos Moleculares , Neurônios/metabolismo , Estresse Oxidativo , RatosRESUMO
Multivalent proteins and nucleic acids, collectively referred to as multivalent associative biomacromolecules, provide the driving forces for the formation and compositional regulation of biomolecular condensates. Here, we review the key concepts of phase transitions of aqueous solutions of associative biomacromolecules, specifically proteins that include folded domains and intrinsically disordered regions. The phase transitions of these systems come under the rubric of coupled associative and segregative transitions. The concepts underlying these processes are presented, and their relevance to biomolecular condensates is discussed.
Assuntos
Proteínas Intrinsicamente Desordenadas , Ácidos Nucleicos , Transição de Fase , Proteínas , Proteínas Intrinsicamente Desordenadas/metabolismoRESUMO
Dieldrin is an organochlorine insecticide that was widely used until 1970 when its use was banned because of its liver carcinogenicity in mice. Several long-term rodent bioassays have reported dieldrin to induce liver tumors in in several strains of mice, but not in rats. This article reviews the available information on dieldrin liver effects and performs an analysis of mode of action (MOA) and human relevance of these liver findings. Scientific evidence strongly supports a MOA based on CAR activation, leading to alterations in gene expression, which result in increased hepatocellular proliferation, clonal expansion leading to altered hepatic foci, and ultimately the formation of hepatocellular adenomas and carcinomas. Associative events include increased liver weight, centrilobular hypertrophy, increased expression of Cyp2b10 and its resulting increased enzymatic activity. Other associative events include alterations of intercellular gap junction communication and oxidative stress. Alternative MOAs are evaluated and shown not to be related to dieldrin administration. Weight of evidence shows that dieldrin is not DNA reactive, it is not mutagenic, and it is not genotoxic in general. Furthermore, activation of other pertinent nuclear receptors, including PXR, PPARα, AhR, and estrogen are not related to dieldrin-induced liver tumors nor is there liver cytotoxicity. In previous studies, rats, dogs, and non-human primates did not show increased cell proliferation or production of pre-neoplastic or neoplastic lesions following dieldrin treatment. Thus, the evidence strongly indicates that dieldrin-induced mouse liver tumors are due to CAR activation and are specific to the mouse, which are qualitatively not relevant to human hepatocarcinogenesis. Thus, there is no carcinogenic risk to humans. This conclusion is also supported by a lack of positive epidemiologic findings for evidence of liver carcinogenicity. Based on current understanding of the mode of action of dieldrin-induced liver tumors in mice, the appropriate conclusion is that dieldrin is a mouse specific liver carcinogen and it does not pose a cancer risk to humans.
Assuntos
Dieldrin , Neoplasias Hepáticas , Dieldrin/toxicidade , Animais , Humanos , Neoplasias Hepáticas/induzido quimicamente , Medição de Risco , Inseticidas/toxicidade , Camundongos , Ratos , Receptor Constitutivo de Androstano , Fígado/efeitos dos fármacos , Fígado/patologiaRESUMO
Biomolecular condensates are viscoelastic materials defined by time-dependent, sequence-specific complex shear moduli. Here, we show that viscoelastic moduli can be computed directly using a generalization of the Rouse model that leverages information regarding intra- and inter-chain contacts, which we extract from equilibrium configurations of lattice-based Metropolis Monte Carlo (MMC) simulations of phase separation. The key ingredient of the generalized Rouse model is a graph Laplacian that we compute from equilibrium MMC simulations. We compute two flavors of graph Laplacians, one based on a single-chain graph that accounts only for intra-chain contacts, and the other referred to as a collective graph that accounts for inter-chain interactions. Calculations based on the single-chain graph systematically overestimate the storage and loss moduli, whereas calculations based on the collective graph reproduce the measured moduli with greater fidelity. However, in the long time, low-frequency domain, a mixture of the two graphs proves to be most accurate. In line with the theory of Rouse and contrary to recent assertions, we find that a continuous distribution of relaxation times exists in condensates. The single crossover frequency between dominantly elastic vs dominantly viscous behaviors does not imply a single relaxation time. Instead, it is influenced by the totality of the relaxation modes. Hence, our analysis affirms that viscoelastic fluid-like condensates are best described as generalized Maxwell fluids. Finally, we show that the complex shear moduli can be used to solve an inverse problem to obtain the relaxation time spectra that underlie the dynamics within condensates. This is of practical importance given advancements in passive and active microrheology measurements of condensate viscoelasticity.
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Condensados Biomoleculares , Método de Monte Carlo , Viscosidade , Condensados Biomoleculares/química , ElasticidadeRESUMO
This special article is the 17th in an annual series for the Journal of Cardiothoracic and Vascular Anesthesia. The authors thank the editor in chief, Dr Kaplan, and the editorial board for the opportunity to continue this series, namely, the research highlights of the past year in the specialty of cardiothoracic and vascular anesthesiology.1 The major themes selected for 2024 are outlined in this introduction, and each highlight is reviewed in detail in the main article. The literature highlights in the specialty for 2024 begin with an update on perioperative rehabilitation and enhanced recovery in cardiothoracic surgery, with a focus on novel methods to best assess our patients in the preoperative period and the impact of implementing enhanced recovery care models on outcomes. The second major theme is focused on cardiac surgery, with the authors discussing new insights into anemia, transfusions, and coronary artery bypass grafting outcomes with a focus on gender disparities. The third theme is focused on cardiothoracic transplantation, with discussions focusing on techniques related to lung transplantation, including mechanical circulatory support. The 4th theme is focused on mechanical circulatory support, with discussions exploring advancements in left ventricular assist devices highlight the evolving landscape of mechanical circulatory support and discussion of anticoagulation practices. The fifth and final theme is an update on medical cardiology, with a focus on the outcomes of transcatheter management of regurgitant pathology, device management in heart failure, and new techniques in catheter ablation. The themes selected for this article are only a few of the diverse advances in the specialty during 2024. These highlights will inform the reader of key updates on a variety of topics, leading to improvement in perioperative outcomes for patients with cardiothoracic and vascular disease.
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Carbon tetrachloride (CCl4) has been extensively used and reported to produce toxicity, most notably involving the liver. Carbon tetrachloride metabolism involves CYP450-mediated bioactivation to trichloromethyl and trichloromethyl peroxy radicals, which are capable of macromolecular interaction with cell components including lipids and proteins. Radical interaction with lipids produces lipid peroxidation which can mediate cellular damage leading to cell death. Chronic exposure with CCl4 a rodent hepatic carcinogen with a mode of action (MOA) exhibits the following key events: 1) metabolic activation; 2) hepatocellular toxicity and cell death; 3) consequent regenerative increased cell proliferation; and 4) hepatocellular proliferative lesions (foci, adenomas, carcinomas). The induction of rodent hepatic tumors is dependent upon the dose (concentration and exposure duration) of CCl4, with tumors only occurring at cytotoxic exposure levels. Adrenal benign pheochromocytomas were also increased in mice at high CCl4 exposures; however, these tumors are not of relevant importance to human cancer risk. Few epidemiology studies that have been performed on CCl4, do not provide credible evidence of enhanced risk of occurrence of liver or adrenal cancers, but these studies have serious flaws limiting their usefulness for risk assessment. This manuscript summarizes the toxicity and carcinogenicity attributed to CCl4, specifically addressing MOA, dose-response, and human relevance.
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Neoplasias das Glândulas Suprarrenais , Neoplasias Hepáticas , Feocromocitoma , Camundongos , Humanos , Animais , Tetracloreto de Carbono/toxicidade , Tetracloreto de Carbono/metabolismo , Neoplasias Hepáticas/induzido quimicamente , LipídeosRESUMO
The 1958 Delaney amendment to the Federal Food Drug and Cosmetics Act prohibited food additives causing cancer in animals by appropriate tests. Regulators responded by adopting chronic lifetime cancer tests in rodents, soon challenged as inappropriate, for they led to very inconsistent results depending on the subjective choice of animals, test design and conduct, and interpretive assumptions. Presently, decades of discussions and trials have come to conclude it is impossible to translate chronic animal data into verifiable prospects of cancer hazards and risks in humans. Such conclusion poses an existential crisis for official agencies in the US and abroad, which for some 65 years have used animal tests to justify massive regulations of alleged human cancer hazards, with aggregated costs of $trillions and without provable evidence of public health advantages. This article addresses suitable remedies for the US and potentially worldwide, by critically exploring the practices of regulatory agencies vis-á-vis essential criteria for validating scientific evidence. According to this analysis, regulations of alleged cancer hazards and risks have been and continue to be structured around arbitrary default assumptions at odds with basic scientific and legal tests of reliable evidence. Such practices raise a manifold ethical predicament for being incompatible with basic premises of the US Constitution, and with the ensuing public expectations of testable truth and transparency from government agencies. Potential remedies in the US include amendments to the US Administrative Procedures Act, preferably requiring agencies to justify regulations compliant with the Daubert opinion of the Daubert ruling of the US Supreme Court, which codifies the criteria defining reliable scientific evidence. International reverberations are bound to follow what remedial actions may be taken in the US, the origin of current world regulatory procedures to control alleged cancer causing agents.
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Neoplasias , Saúde Pública , Animais , Humanos , Estados Unidos , Carcinógenos/toxicidade , Neoplasias/induzido quimicamente , Neoplasias/prevenção & controleRESUMO
In contrast to genotoxic carcinogens, there are currently no internationally agreed upon regulatory tools for identifying non-genotoxic carcinogens of human relevance. The rodent cancer bioassay is only used in certain regulatory sectors and is criticized for its limited predictive power for human cancer risk. Cancer is due to genetic errors occurring in single cells. The risk of cancer is higher when there is an increase in the number of errors per replication (genotoxic agents) or in the number of replications (cell proliferation-inducing agents). The default regulatory approach for genotoxic agents whereby no threshold is set is reasonably conservative. However, non-genotoxic carcinogens cannot be regulated in the same way since increased cell proliferation has a clear threshold. An integrated approach for the testing and assessment (IATA) of non-genotoxic carcinogens is under development at the OECD, considering learnings from the regulatory assessment of data-rich substances such as agrochemicals. The aim is to achieve an endorsed IATA that predicts human cancer better than the rodent cancer bioassay, using methodologies that equally or better protect human health and are superior from the view of animal welfare/efficiency. This paper describes the technical opportunities available to assess cell proliferation as the central gateway of an IATA for non-genotoxic carcinogenicity.
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Carcinogênese , Carcinógenos , Animais , Humanos , Carcinógenos/toxicidade , Agroquímicos , Bioensaio , Proliferação de CélulasRESUMO
The non-genotoxic synthetic pyrethroid insecticide permethrin produced hepatocellular adenomas and bronchiolo-alveolar adenomas in female CD-1 mice, but not in male CD-1 mice or in female or male Wistar rats. Studies were performed to evaluate possible modes of action (MOAs) for permethrin-induced female CD-1 mouse liver and lung tumor formation. The MOA for liver tumor formation by permethrin involves activation of the peroxisome proliferator-activated receptor alpha (PPARα), increased hepatocellular proliferation, development of altered hepatic foci, and ultimately liver tumors. This MOA is similar to that established for other PPARα activators and is considered to be qualitatively not plausible for humans. The MOA for lung tumor formation by permethrin involves interaction with Club cells, followed by a mitogenic effect resulting in Club cell proliferation, with prolonged administration producing Club cell hyperplasia and subsequently formation of bronchiolo-alveolar adenomas. Although the possibility that permethrin exposure may potentially result in enhancement of Club cell proliferation in humans cannot be completely excluded, there is sufficient information on differences in basic lung anatomy, physiology, metabolism, and biologic behavior of tumors in the general literature to conclude that humans are quantitatively less sensitive to agents that increase Club cell proliferation and lead to tumor formation in mice. The evidence strongly indicates that Club cell mitogens are not likely to lead to increased susceptibility to lung tumor development in humans. Overall, based on MOA evaluation it is concluded that permethrin does not pose a tumorigenic hazard for humans, this conclusion being supported by negative data from permethrin epidemiological studies.
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Adenoma , Neoplasias Hepáticas , Neoplasias Pulmonares , Adenoma/metabolismo , Animais , Feminino , Humanos , Fígado , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/metabolismo , Masculino , Camundongos , PPAR alfa/metabolismo , PPAR alfa/farmacologia , Permetrina/toxicidade , Ratos , Ratos WistarRESUMO
Protein self-assembly into amyloid fibrils underlies several neurodegenerative conditions, including Alzheimer's and Parkinson's diseases. It has become apparent that the small oligomers formed during this process constitute neurotoxic molecular species associated with amyloid aggregation. Targeting the formation of oligomers represents, therefore, a possible therapeutic avenue to combat these diseases. However, it remains challenging to establish which microscopic steps should be targeted to suppress most effectively the generation of oligomeric aggregates. Recently, we have developed a kinetic model of oligomer dynamics during amyloid aggregation. Here, we use this approach to derive explicit scaling relationships that reveal how key features of the time evolution of oligomers, including oligomer peak concentration and lifetime, are controlled by the different rate parameters. We discuss the therapeutic implications of our framework by predicting changes in oligomer concentrations when the rates of the individual microscopic events are varied. Our results identify the kinetic parameters that control most effectively the generation of oligomers, thus opening a new path for the systematic rational design of therapeutic strategies against amyloid-related diseases.
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Amiloide , Doenças Neurodegenerativas , Amiloide/metabolismo , Proteínas Amiloidogênicas , Humanos , CinéticaRESUMO
Concern over substances that may cause cancer has led to various classification schemes to recognize carcinogenic threats and provide a basis to manage those threats. The least useful schemes have a binary choice that declares a substance carcinogenic or not. This overly simplistic approach ignores the complexity of cancer causation by considering neither how the substance causes cancer, nor the potency of that mode of action. Consequently, substances are classified simply as "carcinogenic", compromising the opportunity to properly manage these kinds of substances. It will likely be very difficult, if not impossible, to incorporate New Approach Methodologies (NAMs) into binary schemes. In this paper we propose a new approach cancer classification scheme that segregates substances by both mode of action and potency into three categories and, as a consequence, provides useful guidance in the regulation and management of substances with carcinogenic potential. Examples are given, including aflatoxin (category A), trichlorethylene (category B), and titanium dioxide (category C), which demonstrate the clear differentiation among these substances that generate appropriate levels of concern and management options.
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Carcinógenos , Neoplasias , Carcinógenos/toxicidade , Humanos , Neoplasias/induzido quimicamente , Medição de RiscoRESUMO
Epyrifenacil (trademark name: Rapidicil®), a novel protoporphyrinogen oxidase (PPO)-inhibiting herbicide, induces hepatocellular adenomas and carcinomas in male CD-1 mice after 78 weeks treatment. The mode of action (MOA) of these mouse liver tumors and their relevance to humans was assessed based on the 2006 International Programme on Chemical Safety (IPCS) Human Relevance Framework. Epyrifenacil is not genotoxic and induced liver tumors via the postulated porphyria-mediated cytotoxicity MOA with the following key events: (#1) PPO inhibition; (#2) porphyrin accumulation; (#3) hepatocellular injury; with (#4) subsequent regenerative cell proliferation; and ultimately (#5) development of liver tumors. This article evaluates the weight of evidence for this MOA based on the modified Bradford Hill criteria. The MOA data were aligned with the dose and temporal concordance, biological plausibility, coherence, strength, consistency, and specificity for a porphyria-mediated cytotoxicity MOA while excluding other alternative MOAs. Although the postulated MOA could qualitatively potentially occur in humans, we demonstrate that it is unlikely to occur in humans because of quantitative toxicodynamic and toxicokinetic differences between mice and humans. Therefore, this MOA is considered not relevant to humans, utilizing the IPCS Human Relevance Framework; consequently, a nonlinear, threshold dose response would be appropriate for human risk assessment.
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Carcinógenos , Neoplasias Hepáticas , Humanos , Camundongos , Masculino , Animais , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Hepáticas/patologia , Proliferação de Células , Medição de RiscoRESUMO
PURPOSE: To systematically review the literature to (1) describe arthroscopic subscapularis repair constructs and outcomes in patients with isolated and combined subscapularis tears and (2) compare outcomes after single- and double-row subscapularis repair in both of these settings. METHODS: A systematic review was performed using PRISMA guidelines. PubMed, SCOPUS, and Cochrane Central Register of Controlled Trials were searched for Level I-IV evidence studies that investigated outcomes after arthroscopic subscapularis repair for the treatment of isolated subscapularis tears or subscapularis tears combined with posterosuperior rotator cuff tears in adult human patients. Data recorded included study demographics, repair construct, shoulder-specific outcome measures, and subscapularis retears. Study methodological quality was analyzed using the MINORS score. Heterogeneity and low levels of evidence precluded meta-analysis. RESULTS: The initial search yielded 811 articles (318 duplicates, 493 screened, 67 full-text review). Forty-three articles (2406 shoulders, 57% males, mean age range 42 to 67.5 years, mean MINORS score 13.4 ± 4.1) were included and analyzed. Articles reported on patients with isolated subscapularis tears (n = 15), combined tears (n = 17), or both (n = 11). The majority of subscapularis repairs used single-row constructs (89.4% of isolated tears, 88.9% of combined tears). All except for one study reporting on outcome measures found clinically significant improvements after subscapularis repair, and no clinically significant differences were detected in 5 studies comparing isolated to combined tears. Subscapularis retear rates ranged from 0% to 17% for isolated tears and 0% to 32% for combined subscapularis and posterosuperior rotator cuff tears. Outcomes and retear rates were similar in studies comparing single-row to double-row repair for isolated and combined subscapularis tears (P > .05 for all). CONCLUSION: Arthroscopic subscapularis repair resulted in significant improvements across all outcome measures, regardless of whether tears were isolated or combined or if repairs were single or double row. LEVEL OF EVIDENCE: Level IV, systematic review of Level II-IV studies.
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Lesões do Manguito Rotador , Manguito Rotador , Adulto , Idoso , Artroscopia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Manguito Rotador/cirurgia , Lesões do Manguito Rotador/cirurgia , Resultado do TratamentoRESUMO
PURPOSE: Rising patient out-of-pocket (OOP) costs and financial distress have been associated with reduced access to and delays in care. We evaluated whether OOP and total costs for common hand procedures have increased from 2008 to 2016 and identified key drivers of these costs. METHODS: Using the IBM MarketScan Research Databases, we identified patients who underwent trigger finger release, open carpal tunnel release, thumb carpometacarpal joint arthroplasty, cubital tunnel release, or open treatment of distal radius fracture in the outpatient setting between 2008 and 2016. Patient OOP costs included copayment, coinsurance, and deductible payments. Costs not directly related to medical care, such as transportation and childcare costs, were not included. The overall cost was defined as the sum of the patient OOP cost and insurer reimbursements. We calculated changes in OOP and total overall costs over the study period. We also performed multivariable linear regressions to evaluate the associations between costs and procedure type, insurance type, region, and site of service. RESULTS: The mean patient OOP cost increased by 55% to 71% and the total overall cost increased by 20% to 45%, depending on the procedure, between 2008 and 2016. Facility overall costs increased by 38%, whereas professional overall costs increased by 9%. Procedures performed in an office-based setting were associated with the lowest patient OOP and total overall costs, whereas high-deductible health plans were associated with the highest OOP costs. CONCLUSIONS: Patient OOP and total overall costs increased for the most common hand procedures between 2008 and 2016, driven by a substantial increase in facility costs. Office-based procedures were associated with the lowest costs. CLINICAL RELEVANCE: To alleviate the rising patient cost burden, hand surgeons could incorporate OOP cost considerations into shared decision-making tools, identify patients who may benefit from financial counseling, and shift procedures to an office-based setting.
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Gastos em Saúde , Humanos , Bases de Dados FactuaisRESUMO
PURPOSE: Continuous measurement of aortic pressure and aortic flow velocity signals in the operating theatre allows us to draw velocity-pressure (Vel-Pre) loops. The global afterload angle (GALA), derived from the Vel-Pre loops, has been linked to cardiac afterload indicators. As age is the major determinant of constitutive arterial stiffness, we aimed to describe (1) the evolution of the GALA according to age in a large cohort of anesthetized patients and (2) GALA variations induced by haemodynamic interventions. METHODS: We included patients for whom continuous monitoring of arterial pressure and cardiac output were indicated. Fluid challenges or vasopressors were administered to treat intra-operative hypotension. The primary endpoint was the comparison of the GALA values between young and old patients. The secondary endpoint was the difference in the GALA values before and after haemodynamic interventions. RESULTS: We included 133 anaesthetized patients: 66 old and 67 young patients. At baseline, the GALA was higher in the old patients than in young patients (38 ± 6 vs. 25 ± 4 degrees; p < 0.001). The GALA was positively associated with age (p < 0.001), but the mean arterial pressure (MAP) and cardiac output were not. The GALA did not change after volume expansion, regardless of the fluid response, but it did increase after vasopressor administration. Furthermore, while a vasopressor bolus led to a similar increase in MAP, phenylephrine induced a more substantial increase in the GALA than noradrenaline (+ 12 ± 5° vs. + 8 ± 5°; p = 0.01). CONCLUSION: In non-cardiac surgery, the GALA seems to be associated with both intrinsic rigidity (reflected by age) and pharmacologically induced vasoconstriction changes (by vasopressors). In addition, the GALA can discriminate the differential effects of phenylephrine and noradrenaline. These results should be confirmed in a prospective, ideally randomized, trial.
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Hipotensão , Vasoconstritores , Débito Cardíaco , Humanos , Hipotensão/tratamento farmacológico , Norepinefrina/farmacologia , Fenilefrina/farmacologia , Estudos Prospectivos , Vasoconstritores/farmacologia , Vasoconstritores/uso terapêuticoRESUMO
BACKGROUND: Plastic surgeons are increasingly turning to social media to market their services. The newly released Twitter Academic Research Product Track (TARPT) database provides free, customizable analysis of keywords that are included in tweets on the Twitter platform. The TARPT tool may provide valuable insight into public interest in cosmetic surgery procedures. OBJECTIVES: The aim of this study was to determine TARPT's utility in tracking and predicting public interest in cosmetic surgery procedures and to examine temporal trends in tweets related to cosmetic facial and body procedures. METHODS: The TARPT tool was used to calculate the total number of tweets containing keywords related to 10 facial cosmetic procedures and 7 cosmetic body procedures from 2010 to 2020. Annual volumes for respective procedures were obtained from annual statistics reports of The Aesthetic Society from 2010 to 2020. Tweet volumes and procedure volumes were compared by univariate linear regression, taking P < 0.05 as the cutoff for significance. RESULTS: Variations in tweet volume were observed. Univariate linear regression analysis demonstrated statistically significant positive correlations between tweet volumes and procedure volumes for 7 search terms: "eyelid lift," "facelift," "lip injections," "mastopexy," "butt lift," "butt implants," and "liposuction." Many procedure-related keywords were not significant, demonstrating the importance of careful selection of Twitter search terms. CONCLUSIONS: The TARPT database represents a promising novel source of information for plastic surgeons, with the potential to inform marketing and advertising decisions for emerging trends in plastic surgery interest before these patterns become apparent in surgical or clinical volumes.
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Lipectomia , Mamoplastia , Mídias Sociais , Cirurgia Plástica , Estética , HumanosRESUMO
BACKGROUND: The utilization of social media in plastic surgery is expanding. The Twitter Academic Research Product Tract (TARPT) database provides plastic surgeons the opportunity to monitor public interest in plastic surgery procedures. Previously, TARPT was shown to be effective in tracking public interest in surgical cosmetic facial and body procedures. OBJECTIVES: The authors sought to determine the ability of the TARPT tool to track and predict public interest in nonsurgical cosmetic procedures and to examine temporal public interest trends in nonsurgical cosmetic procedures. METHODS: The authors employed the TARPT tool to calculate the total number of tweets containing keywords related to 15 nonsurgical cosmetic procedures from 2010 to 2020. Annual case volumes were obtained for each of the 15 procedures from annual reports provided by the American Society of Plastic Surgeons. Univariate linear regression was employed to compare tweet volumes and procedure volumes, with Pâ <â 0.05 as a threshold for significance. RESULTS: Univariate linear regression revealed significant positive correlations between tweet volumes and American Society of Plastic Surgeons procedure volumes for 10 search terms representing 6 nonsurgical cosmetic procedures: "xeomin," "microdermabrasion," "facial filler," "fat filler," "fat injections," "fat transfer," "hyaluronic acid filler," "hyaluronic acid injection," "HA filler," and "PRP filler." Thirty-two search terms did not demonstrate a significant relationship. CONCLUSIONS: The TARPT tool is an informative data source for plastic surgeons with the potential to guide marketing and advertising strategies, and monitor public interest in nonsurgical cosmetic procedures, helping surgeons respond to patients' evolving needs.
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Procedimentos de Cirurgia Plástica , Mídias Sociais , Cirurgia Plástica , Humanos , Estados Unidos , Ácido Hialurônico , Face/cirurgiaRESUMO
Exposure of Sprague-Dawley (SD) rats to acrylamide (AA) or di-butyl-phthalate (DBP) from the 12th gestational day to the 16th postnatal week (PNW) has been shown to reduce the effectiveness of orchiopexy in recovering the testicular alterations associated with experimental cryptorchidism established at weaning. Herein, we provide information about the long-term effects of AA or DBP on the testes of cryptorchid/orchiopexic rats. Male offspring exposed in utero to 10 mg/kg/day AA or 500 mg/kg/day DBP underwent bilateral surgical cryptorchidism at the 3rd PNW and orchiopexy at the 6th week, with continuous exposure to the chemicals through diet until the 58th week. Regardless of the test chemical, there were severe qualitative/quantitative alterations in the seminiferous tubules and increased numbers of Leydig cells. There was an increase and decrease in the number of tubules with c-Kit- and placental alkaline phosphatase-labeled germ cells, respectively, as compared to those in the control group, suggesting an imbalance between apoptosis and cell proliferation processes. The histological scores of the testicular lesions at the end of this one-year study were higher than those in the previous 16-week study, indicating that exposure of rats to the toxicants AA or DBP enhanced the testicular alterations induced by the chemicals beginning at the intra-uterine life, and impaired the effectiveness of orchiopexy in restoring the testes to normal morphology. Although the present experimental protocol does not completely replicate the natural human undescended testes, our findings may contribute to understanding the alterations occurring in cryptorchid/orchiopexic testes potentially exposed to exogenous chemicals for extended periods.