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A common feature in patients with abdominal aortic aneurysms (AAA) is the formation of a nonocclusive intraluminal thrombus (ILT) in regions of aortic dilation. Platelets are known to maintain hemostasis and propagate thrombosis through several redundant activation mechanisms, yet the role of platelet activation in the pathogenesis of AAA associated ILT is still poorly understood. Thus, we sought to investigate how platelet activation impacts the pathogenesis of AAA. Using RNA-sequencing, we identify that the platelet-associated transcripts are significantly enriched in the ILT compared to the adjacent aneurysm wall and healthy control aortas. We found that the platelet specific receptor glycoprotein VI (GPVI) is among the top enriched genes in AAA ILT and is increased on the platelet surface of AAA patients. Examination of a specific indicator of platelet activity, soluble GPVI (sGPVI), in two independent AAA patient cohorts is highly predictive of a AAA diagnosis and associates more strongly with aneurysm growth rate when compared to D-dimer in humans. Finally, intervention with the anti-GPVI antibody (JAQ1) in mice with established aneurysms blunted the progression of AAA in two independent mouse models. In conclusion, we show that levels of sGPVI in humans can predict a diagnosis of AAA and AAA growth rate, which may be critical in the identification of high-risk patients. We also identify GPVI as a novel platelet-specific AAA therapeutic target, with minimal risk of adverse bleeding complications, where none currently exist.
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A common feature in patients with abdominal aortic aneurysms (AAA) is the formation of a nonocclusive intraluminal thrombus (ILT) in regions of aortic dilation. Platelets are known to maintain hemostasis and propagate thrombosis through several redundant activation mechanisms, yet the role of platelet activation in the pathogenesis of AAA associated ILT is still poorly understood. Thus, we sought to investigate how platelet activation impacts the pathogenesis of AAA. Using RNA-sequencing, we identify that the platelet-associated transcripts are significantly enriched in the ILT compared to the adjacent aneurysm wall and healthy control aortas. We found that the platelet specific receptor glycoprotein VI (GPVI) is among the top enriched genes in AAA ILT and is increased on the platelet surface of AAA patients. Examination of a specific indicator of platelet activity, soluble GPVI (sGPVI), in two independent AAA patient cohorts is highly predictive of a AAA diagnosis and associates more strongly with aneurysm growth rate when compared to D-dimer in humans. Finally, intervention with the anti-GPVI antibody (J) in mice with established aneurysms blunted the progression of AAA in two independent mouse models. In conclusion, we show that levels of sGPVI in humans can predict a diagnosis of AAA and AAA growth rate, which may be critical in the identification of high-risk patients. We also identify GPVI as a novel platelet-specific AAA therapeutic target, with minimal risk of adverse bleeding complications, where none currently exist. KEY POINTS: Soluble glycoprotein VI, which is a platelet-derived blood biomarker, predicts a diagnosis of AAA, with high sensitivity and specificity in distinguishing patients with fast from slow-growing AAA.Blockade of glycoprotein VI in mice with established aneurysms reduces AAA progression and mortality, indicating therapeutic potential.
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BACKGROUND: Large-scale human and mechanistic mouse studies indicate a strong relationship between the microbiome-dependent metabolite trimethylamine N-oxide (TMAO) and several cardiometabolic diseases. This study aims to investigate the role of TMAO in the pathogenesis of abdominal aortic aneurysm (AAA) and target its parent microbes as a potential pharmacological intervention. METHODS: TMAO and choline metabolites were examined in plasma samples, with associated clinical data, from 2 independent patient cohorts (N=2129 total). Mice were fed a high-choline diet and underwent 2 murine AAA models, angiotensin II infusion in low-density lipoprotein receptor-deficient (Ldlr-/-) mice or topical porcine pancreatic elastase in C57BL/6J mice. Gut microbial production of TMAO was inhibited through broad-spectrum antibiotics, targeted inhibition of the gut microbial choline TMA lyase (CutC/D) with fluoromethylcholine, or the use of mice genetically deficient in flavin monooxygenase 3 (Fmo3-/-). Finally, RNA sequencing of in vitro human vascular smooth muscle cells and in vivo mouse aortas was used to investigate how TMAO affects AAA. RESULTS: Elevated TMAO was associated with increased AAA incidence and growth in both patient cohorts studied. Dietary choline supplementation augmented plasma TMAO and aortic diameter in both mouse models of AAA, which was suppressed with poorly absorbed oral broad-spectrum antibiotics. Treatment with fluoromethylcholine ablated TMAO production, attenuated choline-augmented aneurysm initiation, and halted progression of an established aneurysm model. In addition, Fmo3-/- mice had reduced plasma TMAO and aortic diameters and were protected from AAA rupture compared with wild-type mice. RNA sequencing and functional analyses revealed choline supplementation in mice or TMAO treatment of human vascular smooth muscle cells-augmented gene pathways associated with the endoplasmic reticulum stress response, specifically the endoplasmic reticulum stress kinase PERK. CONCLUSIONS: These results define a role for gut microbiota-generated TMAO in AAA formation through upregulation of endoplasmic reticulum stress-related pathways in the aortic wall. In addition, inhibition of microbiome-derived TMAO may serve as a novel therapeutic approach for AAA treatment where none currently exist.
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Aneurisma de la Aorta Abdominal , Microbioma Gastrointestinal , Humanos , Ratones , Animales , Porcinos , Ratones Endogámicos C57BL , Colina , Aneurisma de la Aorta Abdominal/inducido químicamente , Aneurisma de la Aorta Abdominal/genética , Aneurisma de la Aorta Abdominal/prevención & controlRESUMEN
Premature ovarian insufficiency is a complex condition with a heterogenous aetiology, and is defined as loss of ovarian function before the age of 40. Early diagnosis and initiation of hormone replacement therapy is essential to alleviate symptoms and prevent later complications as a result of premature oestrogen deficiency. In this clinical review article we present an update on the diagnostics and treatment of the condition.
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Insuficiencia Ovárica Primaria , Femenino , Terapia de Reemplazo de Hormonas/efectos adversos , Humanos , Insuficiencia Ovárica Primaria/diagnóstico , Insuficiencia Ovárica Primaria/tratamiento farmacológico , Insuficiencia Ovárica Primaria/etiologíaAsunto(s)
Hepatopatías , Trombosis de la Vena , Niño , Fibrinógeno , Humanos , Vena Porta , Trombosis de la Vena/etiologíaRESUMEN
Pulsed dipolar electron paramagnetic resonance (PDEPR) spectroscopy experiments measure the dipolar coupling, and therefore nanometer-scale distances and distance distributions, between paramagnetic centers. Of the family of PDEPR experiments, the most commonly used pulsed sequence is four-pulse double electron resonance (DEER, also known as PELDOR). There are several ways to analyze DEER data to extract distance distributions, and this may appear overwhelming at first. This work compares and reviews six of the packages, and a brief getting started guide for each is provided.
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This is a methodological guide to the use of deep neural networks in the processing of pulsed dipolar spectroscopy (PDS) data encountered in structural biology, organic photovoltaics, photosynthesis research, and other domains featuring long-lived radical pairs and paramagnetic metal ions. PDS uses distance dependence of magnetic dipolar interactions; measuring a single well-defined distance is straightforward, but extracting distance distributions is a hard and mathematically ill-posed problem requiring careful regularisation and background fitting. Neural networks do this exceptionally well, but their "robust black box" reputation hides the complexity of their design and training - particularly when the training dataset is effectively infinite. The objective of this paper is to give insight into training against simulated databases, to discuss network architecture choices, to describe options for handling DEER (double electron-electron resonance) and RIDME (relaxation-induced dipolar modulation enhancement) experiments, and to provide a practical data processing flowchart.
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Redes Neurales de la Computación , Espectroscopía de Resonancia por Spin del Electrón/métodosRESUMEN
Schistosomiasis control requires multisectoral approaches including praziquantel treatment, access to safe water, sanitation and hygiene, and health education. Community input can help ensure health education programs are culturally appropriate to effectively direct protective behavior change. This study reports on the three-stage development of an education program for Malagasy children, with an impact evaluation on their knowledge, attitudes, and practices (KAP) related to intestinal schistosomiasis. A cross-sectional study took place in 2017 with follow-up in 2018 in the hard-to-reach Marolambo district, Madagascar. A novel schistosomiasis education program (SEP) was designed in collaboration with researchers, stakeholders, and local community and included cartoon books, games, songs, puzzles, and blackboard lessons, costing $10 USD per school. KAP questionnaires were completed by 286 children pre-SEP and 273 children post-SEP in 2017, and by 385 and 337 children pre-SEP and post-SEP, respectively, in 2018. Improvements were observed in responses to all questions between pre- and post-education answers in 2017 (53-77%, P < 0.0001) and 2018 (72-98%, P < 0.0001) and in the pre-education answers between years (53-72%, P < 0.0001). Praziquantel mass drug administration attendance improved, rising from 64% to 91% (P < 0.0001), alongside improved latrine use, from 89% to 96% (P = 0.005). This community-consulted and -engaged SEP resulted in substantial improvements in children's understanding of schistosomiasis, with improvements in praziquantel uptake and latrine use. Socioculturally tailored education programs can help gain schistosomiasis control. Continued investment in SEP will help promote the future well-being of children through increased participation in control and treatment activities.
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Salud Infantil/etnología , Participación de la Comunidad/métodos , Educación en Salud/métodos , Conocimientos, Actitudes y Práctica en Salud , Evaluación de Programas y Proyectos de Salud , Esquistosomiasis/prevención & control , Adolescente , Niño , Preescolar , Estudios Transversales , Femenino , Estudios de Seguimiento , Humanos , Madagascar , MasculinoRESUMEN
In the study of biological structures, pulse dipolar spectroscopy (PDS) is used to elucidate spin-spin distances at nanometre-scale by measuring dipole-dipole interactions between paramagnetic centres. The PDS methods of Double Electron Electron Resonance (DEER) and Relaxation Induced Dipolar Modulation Enhancement (RIDME) are employed, and their results compared, for the measurement of the dipolar coupling between nitroxide spin labels and copper-II (Cu(II)) paramagnetic centres within the copper amine oxidase from Arthrobacter globiformis (AGAO). The distance distribution results obtained indicate that two distinct distances can be measured, with the longer of these at c.a. 5 nm. Conditions for optimising the RIDME experiment such that it may outperform DEER for these long distances are discussed. Modelling methods are used to show that the distances obtained after data analysis are consistent with the structure of AGAO. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00723-021-01321-6.
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School-aged children (SAC) have a considerable burden of intestinal schistosomiasis in Madagascar yet its burden in pre-school aged children (PSAC) is currently overlooked. To assess the at-risk status of PSAC, we undertook a pilot epidemiological survey in June 2019 examining children (n = 89), aged 2-4-years of balanced gender, in six remote villages in Marolambo District, Madagascar. Diagnosis included use of urine-circulating cathodic antigen (CCA) dipsticks and coproscopy of stool with duplicate Kato-Katz (K-K) thick smears. Prevalence of intestinal schistosomiasis by urine-CCA was 67.4% (95% confidence interval [CI]: 56.5-77.2%) and 35.0% (95% CI: 24.7-46.5%) by K-K. The relationship between faecal eggs per gram (epg) and urine-CCA G-scores (G1 to G10) was assessed by linear regression modelling, finding for every increment in G-score, epg increased by 20.4 (6.50-34.4, P = 0.006). Observed proportions of faecal epg intensities were light (78.6%), moderate (17.9%) and heavy (3.6%). Soil-transmitted helminthiasis was noted, prevalence of ascariasis was 18.8% and trichuriasis was 33.8% (hookworm was not reported). Co-infection of intestinal schistosomiasis and soil-transmitted helminthiasis occurred in 36.3% of PSAC. These results provide solid evidence highlighting the overlooked burden of intestinal schistosomiasis in PSAC, and they also offer technical guidance for better surveillance data for the Madagascan national control programme.
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Helmintiasis , Esquistosomiasis mansoni , Animales , Niño , Preescolar , Estudios Transversales , Heces , Humanos , Madagascar/epidemiología , Prevalencia , Schistosoma mansoni , Esquistosomiasis mansoni/epidemiologíaRESUMEN
Schistosomiasis is a major public health problem in Madagascar. The WHO recommends preventive chemotherapy by mass drug administration (MDA) with praziquantel as the primary approach to control Schistosoma mansoni-related morbidity in endemic populations, alongside complementary interventions such as health education. The impact of annual MDA and health education programs was assessed in the hard-to-reach Marolambo district of eastern Madagascar, an area endemic for S. mansoni. Repeated cross-sectional studies undertaken 2015-2019 examined between 300 and 381 school-aged children (aged 5-14 years) annually. The prevalence and infection intensity of S. mansoni were assessed by urine-circulating cathodic antigen (CCA) dipsticks and coproscopy using Kato-Katz (KK) methodologies. After four rounds of annual MDA, a reduction in S. mansoni prevalence was seen in CCA (93.9% in year 1-87.7% in year 5; P = 0.007) and KK (73.9% in year 1-59.4% in year 5; P < 0.0001). The prevalence of heavy-intensity infections roughly halved from 23.7% to 10.1% (P < 0.0001), and the mean intensity of infection fell by 55.0% (480.2-216.3 eggs per gram of feces). A malacological survey found Biomphalaria pfeifferi snail intermediate hosts in multiple water contact sites including rice paddies, streams, and Nosivolo River. Despite reductions in infection prevalence and intensity, schistosomiasis still poses a significant public health challenge in Marolambo district. Twice yearly MDA cycles and/or community-wide MDA are suggested to better reduce infections. Expanding health education, improving standards of water, sanitation and hygiene, and attention on snail-related control will also be important, especially in rice paddy irrigated areas.
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Esquistosomiasis mansoni/epidemiología , Esquistosomiasis mansoni/patología , Adolescente , Animales , Antihelmínticos/administración & dosificación , Antihelmínticos/uso terapéutico , Niño , Preescolar , Enfermedad Crónica , Femenino , Humanos , Madagascar/epidemiología , Masculino , Administración Masiva de Medicamentos , Praziquantel/administración & dosificación , Praziquantel/uso terapéutico , Prevalencia , Schistosoma mansoni/fisiología , Esquistosomiasis mansoni/tratamiento farmacológicoRESUMEN
AIMS: Examine and evaluate the overall effectiveness of age gates preventing access of underage users to alcohol websites. METHODS: Assess the characteristics of digital age gates among the top 25 alcohol brands among American adolescents, including type of age gate employed and resulting actions of repeated access requests indicating the user was under the legal drinking age. RESULTS: All official alcohol brand websites examined included an age gate, requiring either entering one's date of birth (DOB, 91%) or clicking a yes/no box indicating they were of legal drinking age (9%). Only one out of every five alcohol websites blocked futures attempts to gain access after entering a response indicating the user was under the legal drinking age. Users were allowed indefinite attempts to enter a DOB that was of legal drinking age, with the majority of websites subsequently granting access even after multiple underage entries. CONCLUSIONS: Alcohol website visitors with minimal arithmetic abilities, such as very young youth, are able to employ 'trial and error' to eventually enter an acceptable legal drinking DOB and gain access. Alcohol brand age gates are weak, at best, and likely an inconsequential barrier that someone with limited math abilities can easily overcome.
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Publicidad , Bebidas Alcohólicas , Internet , Consumo de Alcohol en Menores/prevención & control , Humanos , Estados UnidosRESUMEN
US ports and container/intermodal terminals are critical links in the marine transportation system. Disruption at a port can have a crippling economic effect in the coastal zone as well as the rest of the nation. Port stakeholders have a vested interest in the long-term function and viability of ports, but no standardized measures for performance or resilience exist for ports. The goal of this research is to demonstrate the utility of a predictive port resilience assessment tool. The developed tool encompasses a microscopic traffic simulation model (VISSIM) based hybrid multimodal analyzes of port operations and provides a quantifiable assessment of resilience. The application of this tool is shown on six ports in the Southeast US. The waterside port simulation models were developed using vessel automatic identification system data and programed within a VISSIM simulation of landside operations. This hybrid modeling approach was used to visualize vessels and allow them to interact in both time and space with each other and landside infrastructure. Local and regional resilience was quantified through the analysis of time-dependent resilience plots and used as a performance measure in this study. The utility of the predictive port resilience assessment was demonstrated in response to Hurricane Matthew (2016). However, the novel procedure described herein can be applied to any port hazard. This research grows the understanding of the regional consequences of hurricane events and enhances the knowledge in the development of a stakeholder-focused tool to assess resilience.
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The activated form of coagulation factor XIII (FXIII-A2B2), FXIII-A*, is a hemostatic enzyme essential for inhibiting fibrinolysis by irreversibly crosslinking fibrin and antifibrinolytic proteins. Despite its importance, there are no modulatory therapeutics. Guided by the observation that humans deficient in FXIII-B have reduced FXIII-A without severe bleeding, we hypothesized that a suitable small interfering RNA (siRNA) targeting hepatic FXIII-B could safely decrease FXIII-A. Here we show that knockdown of FXIII-B with siRNA in mice and rabbits using lipid nanoparticles resulted in a sustained and controlled decrease in FXIII-A. The concentration of FXIII-A in plasma was reduced by 90% for weeks after a single injection and for more than 5 months with repeated injections, whereas the concentration of FXIII-A in platelets was unchanged. Ex vivo, crosslinking of α2-antiplasmin and fibrin was impaired and fibrinolysis was enhanced. In vivo, reperfusion of carotid artery thrombotic occlusion was also enhanced. Re-bleeding events were increased after challenge, but blood loss was not significantly increased. This approach, which mimics congenital FXIII-B deficiency, provides a potential pharmacologic and experimental tool to modulate FXIII-A2B2 activity.
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Plaquetas/metabolismo , Deficiencia del Factor XIII , Factor XIII/metabolismo , Factor XIIIa/metabolismo , Hemorragia/sangre , Animales , Factor XIII/genética , Deficiencia del Factor XIII/sangre , Deficiencia del Factor XIII/inducido químicamente , Deficiencia del Factor XIII/genética , Factor XIIIa/genética , Técnicas de Silenciamiento del Gen , Hemorragia/genética , Ratones , Ratones Noqueados , Nanopartículas , ARN Interferente Pequeño , ConejosRESUMEN
BACKGROUND: A cross-sectional survey was performed to estimate the prevalence of periportal fibrosis in children based on ultrasound examination in the Marolambo district of the Atsinanana region of Madagascar. This is a remote area known to have a high prevalence of intestinal schistosomiasis. METHODS: School-aged children (5-14 y) were selected from six villages for parasitological and sonographic examination. Circulating cathodic antigen (CCA) tests and Kato Katz (KK) stool microscopy were performed. Video-clips of liver views were recorded with a SonoSite iViz and interpreted in the UK by comparison with standardised images (WHO protocol). RESULTS: The prevalence of schistosomiasis according to CCA testing was 97.8% (269/275) and 73.8% (203/275) by KK. Sonographic evidence of periportal fibrosis was observed in 11.3% (31/275). The youngest children with fibrosis were aged 6 y. Fibrosis was more common in older children (p=0.03) but was not associated with either infection intensity category (p=0.07) or gender (p=0.67). CONCLUSIONS: Findings of periportal fibrosis among children in these hard-to-reach villages suggests chronic Schistosoma mansoni infection from a very young age. This may reflect other similarly remote schistosomiasis-endemic areas and reinforces the need to investigate morbidity in neglected communities to understand the true extent of disease burden in endemic countries.
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Esquistosomiasis mansoni , Animales , Antígenos Helmínticos , Niño , Estudios Transversales , Heces , Humanos , Cirrosis Hepática/diagnóstico por imagen , Cirrosis Hepática/epidemiología , Madagascar/epidemiología , Prevalencia , Schistosoma mansoni , Esquistosomiasis mansoni/epidemiología , Instituciones AcadémicasAsunto(s)
Alergia e Inmunología , Vacuna contra el Herpes Zóster/inmunología , Herpes Zóster/inmunología , Herpesvirus Humano 3/fisiología , Hipersensibilidad/inmunología , Vacunación Masiva/economía , Proteínas del Envoltorio Viral/inmunología , Adulto , Costos y Análisis de Costo , Femenino , Herpes Zóster/economía , Herpes Zóster/epidemiología , Humanos , Hipersensibilidad/economía , Hipersensibilidad/epidemiología , Reembolso de Seguro de Salud , Lípido A/análogos & derivados , Lípido A/inmunología , Masculino , Persona de Mediana Edad , Guías de Práctica Clínica como Asunto , Saponinas/inmunología , Estados Unidos/epidemiología , Vacunas Sintéticas , Proteínas del Envoltorio Viral/genéticaAsunto(s)
Epinefrina , Hipersensibilidad , Alérgenos , Desensibilización Inmunológica , Humanos , InmunoterapiaRESUMEN
Abdominal aortic aneurysm (AAA) is associated with high morbidity and mortality and is an established cause of unbalanced hemostasis. A number of hemostatic biomarkers have been associated with AAA; however, the utility of hemostatic biomarkers in AAA diagnosis and prognosis is unclear. The aim of the present study was to characterize the potential prognostic value of D-dimer and markers of altered hemostasis in a large cohort of patients with AAAs characterized by either fast or slow aneurysm growth (frequency matched for baseline diameter) and subaneurysmal dilations. We measured plasma concentrations of thrombin-antithrombin (TAT) complex, platelet factor 4 (PF4), and D-dimer in 352 patients with either fast-growing AAAs (>2 mm/y), slow-growing AAAs (<2 mm/y), subaneurysmal aortic dilations, or nonaneurysmal aortas. Plasma D-dimer and TAT were significantly elevated in both AAA and subaneurysmal dilation patients compared with controls. Individuals with D-dimer levels ≥500 ng/mL had 3.09 times the odds of subaneurysms, 6.23 times the odds of slow-growing AAAs, and 7.19 times the odds of fast-growing AAAs than individuals with D-dimer level <500 ng/mL. However, no differences in D-dimer concentration were noted between fast- and slow-growing aneurysms. Plasma D-dimer and TAT were strong independent predictors of AAA growth rate with multivariate analysis revealing a 500-ng/mL increase in D-dimer or 1-µg/mL increase in TAT led to additional 0.21-mm and 0.24-mm changes in aortic diameter per year, respectively. Rising levels of plasma TAT, in addition to D-dimer, may predict disease progression and aneurysm growth in patients with AAA or subaneurysmal dilation.
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Aneurisma de la Aorta Abdominal/diagnóstico , Biomarcadores/sangre , Productos de Degradación de Fibrina-Fibrinógeno/análisis , Anciano , Antitrombina III , Aneurisma de la Aorta Abdominal/patología , Estudios de Casos y Controles , Progresión de la Enfermedad , Femenino , Humanos , Modelos Logísticos , Masculino , Oportunidad Relativa , Péptido Hidrolasas/sangre , Factor Plaquetario 4/sangre , Pronóstico , Factores de RiesgoRESUMEN
Abdominal aortic aneurysm (AAA) is a degenerative vascular pathology resulting in significant morbidity and mortality in older adults due to rupture and sudden death. Despite 150 000 new cases and nearly 15 000 deaths annually, the only approved treatment of AAA is surgical or endovascular intervention when the risk for aortic rupture is increased. The goal of the scientific community is to develop novel pharmaceutical treatment strategies to reduce the need for surgical intervention. Because most clinically relevant AAAs contain a complex structure of fibrin, inflammatory cells, platelets, and red blood cells in the aneurysmal sac known as an intraluminal thrombus (ILT), antithrombotic therapies have emerged as potential pharmaceutical agents for the treatment of AAA progression. However, the efficacy of these treatments has not been shown, and the effects of shrinking the ILT may be as detrimental as they are beneficial. This review discusses the prospect of anticoagulant and antiplatelet (termed collectively as antithrombotic) therapies in AAA. Herein, we discuss the role of the coagulation cascade and platelet activation in human and animal models of AAA, the composition of ILT in AAA, a possible role of the ILT in aneurysm stabilization, and the implications of antithrombotic drugs in AAA treatment.
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Aneurisma de la Aorta Abdominal/tratamiento farmacológico , Rotura de la Aorta/prevención & control , Fibrinolíticos/uso terapéutico , Inhibidores de Agregación Plaquetaria/orina , Animales , Aneurisma de la Aorta Abdominal/sangre , Aneurisma de la Aorta Abdominal/patología , Rotura de la Aorta/sangre , Rotura de la Aorta/patología , Coagulación Sanguínea/efectos de los fármacos , Fibrinolíticos/efectos adversos , Humanos , Inhibidores de Agregación Plaquetaria/efectos adversos , Trombosis/sangre , Trombosis/tratamiento farmacológico , Trombosis/patologíaRESUMEN
There are over two million individuals living with amputations in the United States. Almost all will experience the feeling of the amputated limb as still present, termed phantom limb sensation (PLS). Over 85% will also experience excruciatingly painful sensations known as phantom limb pain (PLP). Additionally some amputees also experience a sensation of the phantom limb in which the limb is immobile or stuck in a normal or abnormal anatomical position, termed frozen phantom sensations. When an amputee experiences a frozen limb they report that they are unable to move the limb, and sometimes report sensations of cramping and pain along with this immobility, fortunately not all frozen limbs are painful. Such sensations have previously been attributed to proprioceptive memories of the limb prior to amputation or a mismatch between visual feedback and proprioceptive feedback resulting from the initiation of a movement. Unfortunately there has been a dearth of research specifically focused on the frozen PLS. We conducted a survey to better elucidate and understand the characteristics and experiences of frozen PLSs. Results from the survey provided descriptions of a variety of frozen limb experiences, such as position and feelings experienced, combined with other phantom pain sensations, casting doubt on previous theories regarding frozen limbs. Further research needs to be focused on the etiology of phantom sensations and pain, which may not necessarily be maintained by the same processes, in order to understand better ways to treat PLP, increase mobility, and enhance amputees quality of life.