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1.
Emerg Med Clin North Am ; 41(2): 295-305, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37024165

RESUMEN

Pregnancy-related emergency department visits are common in the United States. Although typically managed safely in the outpatient setting, patients with spontaneous abortion may also present with life-threatening hemorrhage or infection. Management strategies for spontaneous abortion are similarly wide-ranging from expectant management to emergent surgical intervention. Surgical management of complicated therapeutic abortion is similar to that of spontaneous abortion. The dramatic changes in the legal status of abortion in the United States may have significant influence on the incidence of complicated therapeutic abortion, and we encourage emergency physicians to familiarize themselves with the diagnosis and management of these conditions.


Asunto(s)
Aborto Espontáneo , Embarazo , Femenino , Humanos , Estados Unidos/epidemiología , Aborto Espontáneo/diagnóstico , Aborto Espontáneo/terapia , Aborto Terapéutico , Servicio de Urgencia en Hospital
2.
Development ; 150(2)2023 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-36458554

RESUMEN

Adenosine deaminase acting on RNA 1 (ADAR1) is an RNA-binding protein that deaminates adenosine (A) to inosine (I). A-to-I editing alters post-transcriptional RNA processing, making ADAR1 a crucial regulator of gene expression. Consequently, Adar1 has been implicated in organogenesis. To determine the role of Adar1 in pancreatic development and homeostasis, we conditionally deleted Adar1 from the murine pancreas (Ptf1aCre/+; Adar1Fl/Fl). The resulting mice had stunted growth, likely due to malabsorption associated with exocrine pancreatic insufficiency. Analyses of pancreata revealed ductal cell expansion, heightened interferon-stimulated gene expression and an increased influx of immune cells. Concurrent deletion of Adar1 and Mavs, a signaling protein implicated in the innate immune pathway, rescued the degenerative phenotype and resulted in normal pancreatic development. Taken together, our work suggests that the primary function of Adar1 in the pancreas is to prevent aberrant activation of the Mavs-mediated innate immune pathway, thereby maintaining pancreatic homeostasis.


Asunto(s)
Páncreas Exocrino , Animales , Ratones , Páncreas Exocrino/metabolismo , Interferones/genética , Interferones/metabolismo , Fenotipo , Adenosina Desaminasa/genética , Adenosina Desaminasa/metabolismo
3.
Cancer Res ; 82(15): 2761-2776, 2022 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-35666804

RESUMEN

Conventional genetically engineered mouse models (GEMM) are time-consuming, laborious, and offer limited spatiotemporal control. Here, we describe the development of a streamlined platform for in vivo gene activation using CRISPR activation (CRISPRa) technology. Unlike conventional GEMMs, this model system allows for flexible, sustained, and timed activation of one or more target genes using single or pooled lentiviral guides. Myc and Yap1 were used as model oncogenes to demonstrate gene activation in primary pancreatic organoid cultures in vitro and enhanced tumorigenic potential in Myc-activated organoids when transplanted orthotopically in vivo. Implementation of this model as an autochthonous lung cancer model showed that transduction-mediated activation of Myc led to accelerated tumor progression and significantly reduced overall survival relative to nontargeted tumor controls. Furthermore, Myc activation led to the acquisition of an immune suppressive, "cold" tumor microenvironment. Cross-species validation of these results using publicly available RNA/DNA-seq datasets linked MYC to a previously described immunosuppressive molecular subtype in patient tumors, thus identifying a patient cohort that may benefit from combined MYC- and immune-targeted therapies. Overall, this work demonstrates how CRISPRa can be used for rapid functional validation of putative oncogenes and may allow for the identification and evaluation of potential metastatic and oncogenic drivers through competitive screening. SIGNIFICANCE: A streamlined platform for programmable CRISPR gene activation enables rapid evaluation and functional validation of putative oncogenes in vivo.


Asunto(s)
Adenocarcinoma del Pulmón , Neoplasias Pulmonares , Proteínas Proto-Oncogénicas c-myc , Adenocarcinoma del Pulmón/genética , Animales , Carcinogénesis/genética , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Ratones , Oncogenes/genética , Proteínas Proto-Oncogénicas c-myc/genética , Microambiente Tumoral/genética
4.
Emerg Med Clin North Am ; 39(4): 781-794, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34600637

RESUMEN

Postprocedural complications encompass a wide array of conditions that vary in acuity, symptoms, index procedure, and treatment. Continued advancements in diagnostic and therapeutic procedures have led to a significant shift of procedures to the ambulatory setting. This trend is of particular interest to the emergency physician, as patients who develop complications often present to an emergency department for evaluation and treatment. Here the authors examine a high-yield collection of procedures, both ambulatory and inpatient, notable for their frequent utilization and unique complication profiles including common laparoscopic surgical procedures, bariatric surgery, endoscopic procedures, interventional radiology procedures, and hernia repairs with implantable mesh.


Asunto(s)
Complicaciones Posoperatorias , Apendicectomía/efectos adversos , Cirugía Bariátrica/efectos adversos , Endoscopía/efectos adversos , Herniorrafia/efectos adversos , Humanos , Laparoscopía/efectos adversos , Nutrición Parenteral/efectos adversos
6.
Am J Emerg Med ; 48: 249-254, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34000525

RESUMEN

Fever of unknown origin (FUO) is defined as persistent fevers without an identifiable cause despite extensive medical workup. Emergency physicians caring for patients reporting a persistent, nonspecific, febrile illness should carefully consider potentially serious non-infectious causes of FUO. We present a case of a 35-year-old man who presented to the emergency department (ED) three times over a 10-day period for persistent febrile illness and was ultimately diagnosed with Adult-Onset Still's Disease (AOSD) after a serum ferritin level was found to be over 42,000 µg/L. AOSD, along with macrophage activation syndrome, catastrophic antiphospholipid syndrome, and septic shock comprise the four hyperferritinemic syndromes. These are potentially life-threatening febrile illnesses that characteristically present with elevated ferritin levels. In this article, we highlight the value of a serum ferritin level in the workup of a patient with prolonged febrile illness and its utility in facilitating early diagnosis and prompt treatment of hyperferritinemic syndromes in the ED.


Asunto(s)
Fiebre de Origen Desconocido/fisiopatología , Hiperferritinemia/sangre , Enfermedad de Still del Adulto/diagnóstico , Adulto , Síndrome Antifosfolípido/sangre , Síndrome Antifosfolípido/complicaciones , Servicio de Urgencia en Hospital , Fiebre de Origen Desconocido/etiología , Humanos , Hiperferritinemia/etiología , Síndrome de Activación Macrofágica/sangre , Síndrome de Activación Macrofágica/complicaciones , Masculino , Choque Séptico/sangre , Choque Séptico/complicaciones , Enfermedad de Still del Adulto/sangre , Enfermedad de Still del Adulto/complicaciones , Enfermedad de Still del Adulto/fisiopatología
7.
Emerg Med Clin North Am ; 39(2): 347-360, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33863464

RESUMEN

Care of geriatric patients with abdominal pain can pose significant diagnostic and therapeutic challenges to emergency physicians. Older adults rarely present with classic signs, symptoms, and laboratory abnormalities. The incidence of life-threatening emergencies, including abdominal aortic aneurysm, mesenteric ischemia, perforated viscus, and other surgical emergencies, is high. This article explores the evaluation and management of several important causes of abdominal pain in geriatric patients with an emphasis on high-risk presentations.


Asunto(s)
Dolor Abdominal/etiología , Enfermedades del Sistema Digestivo/diagnóstico , Dolor Abdominal/terapia , Anciano , Enfermedades del Sistema Digestivo/terapia , Humanos
8.
Nat Cancer ; 2(12): 1338-1356, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-35121902

RESUMEN

Despite efforts in understanding its underlying mechanisms, the etiology of chromosomal instability (CIN) remains unclear for many tumor types. Here, we identify CIN initiation as a previously undescribed function for APOBEC3A (A3A), a cytidine deaminase upregulated across cancer types. Using genetic mouse models of pancreatic ductal adenocarcinoma (PDA) and genomics analyses in human tumor cells we show that A3A-induced CIN leads to aggressive tumors characterized by enhanced early dissemination and metastasis in a STING-dependent manner and independently of the canonical deaminase functions of A3A. We show that A3A upregulation recapitulates numerous copy number alterations commonly observed in patients with PDA, including co-deletions in DNA repair pathway genes, which in turn render these tumors susceptible to poly (ADP-ribose) polymerase inhibition. Overall, our results demonstrate that A3A plays an unexpected role in PDA as a specific driver of CIN, with significant effects on disease progression and treatment.


Asunto(s)
Citidina Desaminasa , Neoplasias Pancreáticas , Animales , Inestabilidad Cromosómica/genética , Citidina Desaminasa/genética , Humanos , Ratones , Neoplasias Pancreáticas/genética , Proteínas/genética , Neoplasias Pancreáticas
9.
Am J Emerg Med ; 39: 151-153, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33039224

RESUMEN

The Cheiro-Oral (COS) Syndrome is a rare neurologic condition characterized by sensory disturbances involving the peri-oral area and the upper extremity, typically isolated to the hand or fingers. The thalamus contralateral to the symptomatic side is the brain region most commonly involved. Most cases are caused by ischemic or hemorrhagic strokes, although other structural lesions have been implicated. These include tumors, subdural hematomas, aneurysms, and infections. The unusual and seemingly unrelated nature of the symptoms may contribute to misdiagnosis and incomplete workup for potentially serious conditions. We are unable to identify a report of this condition in the emergency medicine literature despite the emergency department being the likely point of presentation for patients with COS. In this report, we describe two patients with COS who presented to our emergency department and review the features of COS as described in published case reports.


Asunto(s)
Hemorragia Cerebral/complicaciones , Mano/fisiopatología , Enfermedades de la Boca/diagnóstico , Trastornos Somatosensoriales/diagnóstico , Accidente Cerebrovascular/complicaciones , Anciano , Hemorragia Cerebral/diagnóstico por imagen , Angiografía por Tomografía Computarizada , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Enfermedades de la Boca/etiología , Trastornos Somatosensoriales/etiología , Accidente Cerebrovascular/diagnóstico por imagen , Síndrome , Tálamo/diagnóstico por imagen
10.
Emerg Med Clin North Am ; 38(4): 857-869, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32981622

RESUMEN

The obesity pandemic now affects hundreds of millions of people worldwide. As obesity rates continue to increase, emergency physicians are called on with increasing frequency to resuscitate obese patients. This article discusses important anatomic, physiologic, and practical challenges imposed by obesity on resuscitative care. Impacts on hemodynamic monitoring, airway and ventilator management, and pharmacologic therapy are discussed. Finally, several important clinical scenarios (trauma, cardiac arrest, and sepsis), in which alterations to standard treatments may benefit obese patients, are highlighted.


Asunto(s)
Obesidad/complicaciones , Resucitación/métodos , Manejo de la Vía Aérea/métodos , Analgésicos/administración & dosificación , Antibacterianos/administración & dosificación , Composición Corporal , Fármacos Cardiovasculares/administración & dosificación , Enfermedades Cardiovasculares/complicaciones , Relación Dosis-Respuesta a Droga , Servicio de Urgencia en Hospital , Paro Cardíaco/terapia , Humanos , Hipnóticos y Sedantes/administración & dosificación , Mediciones del Volumen Pulmonar , Consumo de Oxígeno , Farmacocinética , Respiración con Presión Positiva , Sepsis/complicaciones , Sepsis/terapia , Heridas y Lesiones/complicaciones , Heridas y Lesiones/terapia
11.
Anal Chem ; 91(12): 7516-7523, 2019 06 18.
Artículo en Inglés | MEDLINE | ID: mdl-31072097

RESUMEN

Oncology research is increasingly incorporating molecular detection of circulating tumor DNA (ctDNA) as a tool for cancer surveillance and early detection. However, noninvasive monitoring of conditions with low tumor burden remains challenging, as the diagnostic sensitivity of most ctDNA assays is inversely correlated with total DNA concentration and ctDNA abundance. Here we present the Multiplex Enrichment using Droplet Pre-Amplification (MED-Amp) method, which combines single-molecule emulsification and short-round polymerase chain reaction (PCR) preamplification with digital droplet PCR detection of mutant DNA template. The MED-Amp assay increased mutant signal by over 50-fold with minimal distortion in allelic frequency. We demonstrate detection of as few as three mutant copies in wild-type DNA concentrations ranging from 5 to 50 ng. The MED-Amp assay successfully detected KRAS mutant ctDNA in 86% plasma samples obtained from patients with metastatic pancreatic ductal adenocarcinoma. This assay for high-sensitivity rare variant detection is appropriate for liquid biopsy samples or other limited clinical biospecimens.


Asunto(s)
ADN Tumoral Circulante/sangre , Gotas Lipídicas/química , Proteínas Proto-Oncogénicas p21(ras)/genética , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Femenino , Colorantes Fluorescentes/química , Frecuencia de los Genes , Humanos , Límite de Detección , Biopsia Líquida , Masculino , Persona de Mediana Edad , Mutación , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patología , Reacción en Cadena de la Polimerasa
12.
Emerg Med Clin North Am ; 37(2): 193-205, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30940366

RESUMEN

Variations in estrogen levels across a woman's lifetime lead to important changes in genital physiology and pathophysiology. Low estrogen states like menopause and the prepubertal period share important physiologic changes, including more friable, dry, and inelastic mucosa that is prone to irritation, injury, and infection. These and other factors lead to unique gynecologic pathologic conditions encountered at the extremes of age. Age-specific pathologic conditions and differences in examination techniques are discussed.


Asunto(s)
Enfermedades de los Genitales Femeninos/diagnóstico , Factores de Edad , Anciano , Niño , Servicio de Urgencia en Hospital , Femenino , Enfermedades de los Genitales Femeninos/terapia , Genitales Femeninos/lesiones , Humanos
13.
West J Emerg Med ; 20(2): 323-330, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30881553

RESUMEN

Emergency physicians (EP) frequently resuscitate and manage critically ill patients. Resuscitation of the crashing obese patient presents a unique challenge for even the most skilled physician. Changes in anatomy, metabolic demand, cardiopulmonary reserve, ventilation, circulation, and pharmacokinetics require special consideration. This article focuses on critical components in the resuscitation of the crashing obese patient in the emergency department, namely intubation, mechanical ventilation, circulatory resuscitation, and pharmacotherapy. To minimize morbidity and mortality, it is imperative that the EP be familiar with the pearls and pitfalls discussed within this article.


Asunto(s)
Enfermedad Crítica/terapia , Obesidad/complicaciones , Paro Cardíaco Extrahospitalario/terapia , Resucitación/métodos , Antiinfecciosos/uso terapéutico , Anticoagulantes/uso terapéutico , Reanimación Cardiopulmonar/métodos , Fármacos Cardiovasculares/uso terapéutico , Sistema Cardiovascular , Manejo de la Enfermedad , Cálculo de Dosificación de Drogas , Servicio de Urgencia en Hospital , Tratamiento de Urgencia/métodos , Humanos , Hipnóticos y Sedantes/uso terapéutico , Posicionamiento del Paciente , Respiración Artificial/métodos
14.
Emerg Med Clin North Am ; 37(1): 109-119, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30454773

RESUMEN

Tracheostomy is a common procedure for long-term airway management. Although the overall complication rate is greater than 50%, the incidence of serious complications is low. These serious complications can, however, lead to significant morbidity and mortality and it is incumbent on the emergency provider to be prepared to deal with such tracheostomy-related emergencies. The greatest life threats to the tracheostomy patient are decannulation, obstruction, and hemorrhage. Other important but lower-acuity complications include tracheoesophageal fistula formation, tracheal stenosis, infection, and tracheocutaneous fistula formation.


Asunto(s)
Urgencias Médicas , Traqueostomía , Humanos , Hemorragia Bucal/etiología , Hemorragia Bucal/terapia , Traqueostomía/efectos adversos , Traqueostomía/métodos
15.
Clin Pract Cases Emerg Med ; 2(4): 348-352, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30443624

RESUMEN

A 61-year-old male with a recent diagnosis of pemphigus vulgaris was brought to the emergency department for altered mental status. He had recently started taking prednisone to manage his autoimmune disease and had a progressive decline in his mental status along with decreased oral intake. Evaluation revealed hyperosmolar hyperglycemic state (HHS) and occlusive arterial thrombosis, a rare but known complication of HHS. He was resuscitated aggressively with intravenous fluids, insulin, and heparin and admitted to the intensive care unit. Emergency physicians should remain vigilant for ischemic complications in patients with HHS. Early recognition and treatment can reduce the morbidity and mortality associated with this endocrine emergency.

16.
PLoS One ; 13(10): e0204875, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30332430

RESUMEN

BACKGROUND: Physical activity is associated with a lower risk of disease recurrence among colon cancer patients. Circulating tumor cells (CTC) are prognostic of disease recurrence among stage I-III colon cancer patients. The pathways through which physical activity may alter disease outcomes are unknown, but may be mediated by changes in CTCs. METHODS: Participants included 23 stage I-III colon cancer patients randomized into one of three groups: usual-care control, 150 min∙wk-1 of aerobic exercise (low-dose), and 300 min∙wk-1 of aerobic exercise (high-dose) for six months. CTCs from venous blood were quantified in a blinded fashion using an established microfluidic antibody-mediated capture device. Poisson regression models estimated the logarithmic counts of CTCs. RESULTS: At baseline, 78% (18/23) of patients had ≥1 CTC. At baseline, older age (-0.12±0.06; P = 0.04), lymphovascular invasion (0.63±0.25; P = 0.012), moderate/poor histology (1.09±0.34; P = 0.001), body mass index (0.07±0.02; P = 0.001), visceral adipose tissue (0.08±0.04; P = 0.036), insulin (0.06±0.02; P = 0.011), sICAM-1 (0.04±0.02; P = 0.037), and sVCAM-1 (0.06±0.03; P = 0.045) were associated with CTCs. Over six months, significant decreases in CTCs were observed in the low-dose (-1.34±0.34; P<0.001) and high-dose (-1.18±0.40; P = 0.004) exercise groups, whereas no significant change was observed in the control group (-0.59±0.56; P = 0.292). Over six months, reductions in body mass index (-0.07±0.02; P = 0.007), insulin (-0.08±0.03; P = 0.014), and sICAM-1 (-0.07±0.03; P = 0.005) were associated with reductions in CTCs. The main limitations of this proof-of-concept study are the small sample size, heterogenous population, and per-protocol statistical analysis. CONCLUSION: Exercise may reduce CTCs among stage I-III colon cancer patients. Changes in host factors correlated with changes in CTCs. Exercise may have a direct effect on CTCs and indirect effects through alterations in host factors. This hypothesis-generating observation derived from a small pilot study warrants further investigation and replication.


Asunto(s)
Neoplasias del Colon/rehabilitación , Terapia por Ejercicio/métodos , Células Neoplásicas Circulantes/patología , Anciano , Recuento de Células , Neoplasias del Colon/patología , Neoplasias del Colon/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Cooperación del Paciente , Proyectos Piloto , Distribución de Poisson , Distribución Aleatoria
17.
Nat Commun ; 8(1): 1728, 2017 11 23.
Artículo en Inglés | MEDLINE | ID: mdl-29170413

RESUMEN

Intratumoral phenotypic heterogeneity has been described in many tumor types, where it can contribute to drug resistance and disease recurrence. We analyzed ductal and neuroendocrine markers in pancreatic ductal adenocarcinoma, revealing heterogeneous expression of the neuroendocrine marker Synaptophysin within ductal lesions. Higher percentages of Cytokeratin-Synaptophysin dual positive tumor cells correlate with shortened disease-free survival. We observe similar lineage marker heterogeneity in mouse models of pancreatic ductal adenocarcinoma, where lineage tracing indicates that Cytokeratin-Synaptophysin dual positive cells arise from the exocrine compartment. Mechanistically, MYC binding is enriched at neuroendocrine genes in mouse tumor cells and loss of MYC reduces ductal-neuroendocrine lineage heterogeneity, while deregulated MYC expression in KRAS mutant mice increases this phenotype. Neuroendocrine marker expression is associated with chemoresistance and reducing MYC levels decreases gemcitabine-induced neuroendocrine marker expression and increases chemosensitivity. Altogether, we demonstrate that MYC facilitates ductal-neuroendocrine lineage plasticity in pancreatic ductal adenocarcinoma, contributing to poor survival and chemoresistance.


Asunto(s)
Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patología , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , Proteínas Proto-Oncogénicas c-myc/metabolismo , Animales , Antineoplásicos/uso terapéutico , Carcinoma Neuroendocrino/tratamiento farmacológico , Carcinoma Neuroendocrino/metabolismo , Carcinoma Neuroendocrino/patología , Carcinoma Ductal Pancreático/tratamiento farmacológico , Diferenciación Celular , Línea Celular Tumoral , Linaje de la Célula , Desoxicitidina/análogos & derivados , Desoxicitidina/uso terapéutico , Resistencia a Antineoplásicos , Femenino , Xenoinjertos , Humanos , Queratinas/metabolismo , Masculino , Ratones , Ratones de la Cepa 129 , Ratones Endogámicos C57BL , Ratones Transgénicos , Trasplante de Neoplasias , Células Neuroendocrinas/metabolismo , Células Neuroendocrinas/patología , Neoplasias Pancreáticas/tratamiento farmacológico , Pronóstico , Sinaptofisina/metabolismo , Gemcitabina
18.
Proc Natl Acad Sci U S A ; 114(36): 9659-9664, 2017 09 05.
Artículo en Inglés | MEDLINE | ID: mdl-28827327

RESUMEN

Factor V Leiden (F5L ) is a common genetic risk factor for venous thromboembolism in humans. We conducted a sensitized N-ethyl-N-nitrosourea (ENU) mutagenesis screen for dominant thrombosuppressor genes based on perinatal lethal thrombosis in mice homozygous for F5L (F5L/L ) and haploinsufficient for tissue factor pathway inhibitor (Tfpi+/- ). F8 deficiency enhanced the survival of F5L/LTfpi+/- mice, demonstrating that F5L/LTfpi+/- lethality is genetically suppressible. ENU-mutagenized F5L/L males and F5L/+Tfpi+/- females were crossed to generate 6,729 progeny, with 98 F5L/LTfpi+/- offspring surviving until weaning. Sixteen lines, referred to as "modifier of Factor 5 Leiden (MF5L1-16)," exhibited transmission of a putative thrombosuppressor to subsequent generations. Linkage analysis in MF5L6 identified a chromosome 3 locus containing the tissue factor gene (F3). Although no ENU-induced F3 mutation was identified, haploinsufficiency for F3 (F3+/- ) suppressed F5L/LTfpi+/- lethality. Whole-exome sequencing in MF5L12 identified an Actr2 gene point mutation (p.R258G) as the sole candidate. Inheritance of this variant is associated with suppression of F5L/LTfpi+/- lethality (P = 1.7 × 10-6), suggesting that Actr2p.R258G is thrombosuppressive. CRISPR/Cas9 experiments to generate an independent Actr2 knockin/knockout demonstrated that Actr2 haploinsufficiency is lethal, supporting a hypomorphic or gain-of-function mechanism of action for Actr2p.R258G Our findings identify F8 and the Tfpi/F3 axis as key regulators in determining thrombosis balance in the setting of F5L and also suggest a role for Actr2 in this process.


Asunto(s)
Factor V/genética , Trombosis/genética , Proteína 2 Relacionada con la Actina/genética , Secuencia de Aminoácidos , Animales , Mapeo Cromosómico , Modelos Animales de Enfermedad , Etilnitrosourea , Factor VIII/genética , Femenino , Pruebas Genéticas , Haploinsuficiencia , Homocigoto , Humanos , Lipoproteínas/deficiencia , Lipoproteínas/genética , Masculino , Ratones , Ratones Noqueados , Ratones Mutantes , Ratones Transgénicos , Mutagénesis , Embarazo , Factores de Riesgo , Trombosis/prevención & control , Secuenciación del Exoma
19.
mSphere ; 1(4)2016.
Artículo en Inglés | MEDLINE | ID: mdl-27536734

RESUMEN

The bacterial SOS response is a DNA damage repair network that is strongly implicated in both survival and acquired drug resistance under antimicrobial stress. The two SOS regulators, LexA and RecA, have therefore emerged as potential targets for adjuvant therapies aimed at combating resistance, although many open questions remain. For example, it is not well understood whether SOS hyperactivation is a viable therapeutic approach or whether LexA or RecA is a better target. Furthermore, it is important to determine which antimicrobials could serve as the best treatment partners with SOS-targeting adjuvants. Here we derived Escherichia coli strains that have mutations in either lexA or recA genes in order to cover the full spectrum of possible SOS activity levels. We then systematically analyzed a wide range of antimicrobials by comparing the mean inhibitory concentrations (MICs) and induced mutation rates for each drug-strain combination. We first show that significant changes in MICs are largely confined to DNA-damaging antibiotics, with strains containing a constitutively repressed SOS response impacted to a greater extent than hyperactivated strains. Second, antibiotic-induced mutation rates were suppressed when SOS activity was reduced, and this trend was observed across a wider spectrum of antibiotics. Finally, perturbing either LexA or RecA proved to be equally viable strategies for targeting the SOS response. Our work provides support for multiple adjuvant strategies, while also suggesting that the combination of an SOS inhibitor with a DNA-damaging antibiotic could offer the best potential for lowering MICs and decreasing acquired drug resistance. IMPORTANCE Our antibiotic arsenal is becoming depleted, in part, because bacteria have the ability to rapidly adapt and acquire resistance to our best agents. The SOS pathway, a widely conserved DNA damage stress response in bacteria, is activated by many antibiotics and has been shown to play central role in promoting survival and the evolution of resistance under antibiotic stress. As a result, targeting the SOS response has been proposed as an adjuvant strategy to revitalize our current antibiotic arsenal. However, the optimal molecular targets and partner antibiotics for such an approach remain unclear. In this study, focusing on the two key regulators of the SOS response, LexA and RecA, we provide the first comprehensive assessment of how to target the SOS response in order to increase bacterial susceptibility and reduce mutagenesis under antibiotic treatment.

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