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1.
Adv Skin Wound Care ; 37(3): 155-161, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-37590441

RESUMEN

OBJECTIVE: To compare the effectiveness of an antishear mattress overlay (ASMO) with a standard ambulance stretcher surface in reducing pressure and shear and increasing patient comfort. METHODS: In this randomized, crossover design, adults in three body mass index categories served as their own controls. Pressure/shear sensors were applied to the sacrum, ischial tuberosity, and heel. The stretcher was placed in sequential 0°, 15°, and 30° head-of-bed elevations with and without an ASMO. The ambulance traveled a closed course, achieving 30 mph, with five stops at each head-of-bed elevation. Participants rated discomfort after each series of five runs. RESULTS: Thirty individuals participated. Each participant had 30 runs (15 with an ASMO, 15 without), for a total of 900 trial runs. The peak-to-peak shear difference between support surfaces was -0.03 N, indicating that after adjustment for elevation, sensor location, and body mass index, peak shear levels at baseline (starting pause) were 0.03 N lower for the ASMO than for the standard surface ( P = .02). The peak-to-peak pressure difference between surfaces was -0.16 mm Hg, indicating that prerun peak-to-peak pressure was 0.16 mm Hg lower with the ASMO versus standard surface ( P = .002). The heel received the most pressure and shear. Discomfort score distributions differed between surfaces at 0° ( P = .004) and 30° ( P = .01); the overall score across all elevations was significantly higher with the standard surface than with the ASMO ( P = .046). CONCLUSIONS: The ASMO reduced shear, pressure, and discomfort. During transport, the ambulance team should provide additional heel offloading.


Asunto(s)
Servicios Médicos de Urgencia , Úlcera por Presión , Adulto , Humanos , Estudios Cruzados , Talón , Presión , Lechos , Úlcera por Presión/prevención & control
2.
Crit Rev Food Sci Nutr ; 63(11): 1587-1611, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-34404303

RESUMEN

Traditional food processing techniques can no longer meet the ever increasing demand for high quality food across the globe due to its low process efficiency, high energy consumption and low product yield. This review article is focused on the mechanism and application of Infrared (IR) and ultrasound (US) technologies in physical processing of food. We herein present the individual use of IR and US (both mono-frequency and multi-frequency levels) as well as IR and US supported with other thermal and non-thermal technologies to improve their food processing performance. IR and US are recent thermal and non-thermal technologies which have now been successfully used in food industries to solve the demerits of conventional processing technologies. These environmentally-friendly technologies are characterized by low energy consumption, reduced processing time, high mass-transfer rates, better nutrient retention, better product quality, less mechanical damage and improved shelf life. This work could be, with no doubt, useful to the scientific world and food industries by providing insights on recent advances in the use of US and IR technology, which can be applied to improve food processing technologies for better quality and safer products.


Asunto(s)
Manipulación de Alimentos , Calidad de los Alimentos , Manipulación de Alimentos/métodos , Alimentos , Conservación de Alimentos/métodos
3.
Radiographics ; 42(4): E125-E131, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35622490

RESUMEN

The Kaizen method is an approach to lean process improvement that is based on the idea that small ongoing positive changes can lead to major improvements in efficiency and reduction of waste. The hospital-based CT division at Mayo Clinic Arizona had been receiving numerous concerns of delays in the performance of examinations from inpatients, outpatients, and patients presenting to the emergency department. These concerns, along with a planned hospital expansion, provided the impetus to perform a process improvement project with the goal of reducing inpatient, emergency department, and outpatient turnaround times by 20%. Kaizen process improvement was chosen because of the emphasis on reduction of waste, standardization, and empowerment of frontline staff. The project was led by a process improvement coach who was trained in lean process improvement and A3 thinking. At the end of a weeklong Kaizen event, inpatient turnaround time decreased by 54%, emergency department turnaround time decreased by 29%, and outpatient turnaround time decreased by 45%. These results were achieved and sustained by establishing standardized work, developing frontline problem solvers, instituting visual management, aligning with relevant metrics, emphasizing patient and staff satisfaction, and reducing lead time and non-value-added work. When done properly, a Kaizen event can be an effective tool for process improvement in the health care setting. Online supplemental material is available for this article. ©RSNA, 2022.


Asunto(s)
Servicio de Urgencia en Hospital , Hospitales , Eficiencia Organizacional , Humanos , Mejoramiento de la Calidad , Tomografía Computarizada por Rayos X
4.
Radiographics ; 42(3): 919-928, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35333633

RESUMEN

Kaizen process improvement is an element of lean production that is an approach to creating continuous improvement. Kaizen is based on the idea that small ongoing positive changes in workflow and elimination of waste can yield major improvements over time. A focused Kaizen event, or rapid process improvement event, can lead to sustainable process improvement in health care settings that are resistant to change. This approach has been proven to be successful in health care. These events are led by a trained facilitator and coach who provides appropriate team education and engagement. To ensure success, the team must embrace the Kaizen culture, which emphasizes the development of a "learning organization" that is focused on relentless pursuit of perfection. The culture empowers all staff to improve the work they perform, with an emphasis on the process and not the individual. Respect for individual people is key in Kaizen. In radiology, this method has been successful in empowering frontline staff to improve their individual workflows. A 5-day Kaizen event has been successful in increasing on-time starts, decreasing lead time, increasing patient and staff satisfaction, and ensuring sustainability. Sustainable success can occur when the team stays true to lean principles, engages leaders, and empowers team members with the use of timely data to drive decision making. Online supplemental material is available for this article. ©RSNA, 2022.


Asunto(s)
Mejoramiento de la Calidad , Radiología , Humanos
5.
J Appl Clin Med Phys ; 23(3): e13520, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35066975

RESUMEN

Magnetic resonance imaging (MRI) is a valuable imaging modality for the assessment of both cardiac and non-cardiac structures. With a growing population of patients with cardiovascular implantable electronic devices (CIEDs), 50%-75% of these patients will need an MRI. MRI-conditional CIEDs have demonstrated safety of MRI scanning with such devices, yet non-conditional devices such as hybrid CIEDs which have generator and lead brand mismatch may pose a safety risk. In this retrospective study, we examined the outcomes of patients with hybrid CIEDs undergoing MRI compared to those patients with non-hybrid CIEDs. A total of 349 patients were included, of which 24 patients (7%) had hybrid CIEDs. The primary endpoint was the safety of MRI for patients with hybrid CIEDs as compared to those with non-hybrid devices, measured by the rate of adverse events, including death, lead or generator failure needing immediate replacement, loss of capture, new onset arrhythmia, or power-on reset. Secondary endpoints consisted of pre- and post-MRI changes of decreased P-wave or R-wave sensing by ≥50%, changes in pacing lead impedance by ≥50 ohms, increase in pacing thresholds by ≥ 0.5 V at 0.4 ms, and decreasing battery voltage of ≥ 0.04 V. The primary endpoint of any adverse reaction was present in 1 (4.2%) patient with a hybrid device, and consistent of atrial tachyarrhythmia, and in 10 (3.1%) patients with a non-hybrid device, and consisted of self-limited atrial and non-sustained ventricular arrhythmias; this was not statistically significant. No significant differences were found in the secondary endpoints. This study demonstrates that MRI in patients with hybrid CIEDs does not result in increased patient risk or significant device changes when compared to those patients who underwent MRI with non-hybrid CIEDs.


Asunto(s)
Desfibriladores Implantables , Marcapaso Artificial , Electrónica , Humanos , Imagen por Resonancia Magnética/métodos , Estudios Retrospectivos
6.
Alzheimer Dis Assoc Disord ; 35(1): 44-47, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-32960856

RESUMEN

INTRODUCTION: We examined the association between androgen deprivation therapy (ADT) use and the risk of mild cognitive impairment (MCI) among prostate cancer patients. METHODS: We included 241 cognitively unimpaired men, aged 70 to 90, with a history of prostate cancer before enrollment in the population-based Mayo Clinic Study of Aging. Using the Rochester Epidemiology Project medical records-linkage system, ADT use and length of exposure were abstracted. Follow-up visits occurred every 15 months and MCI diagnoses were made based on clinical consensus. Cox proportional hazards models, with age as the timescale, were used to examine the association between ADT use (yes/no) and length of exposure with the risk of MCI adjusting for education, apolipoprotein E, depression, and the Charlson Index score. RESULTS: There was no association between any ADT use (27.8% of participants) and the risk of MCI in the multivariable model [hazard ratio (HR), 1.25; 95% confidence interval (CI), 0.75-2.10]. Although not significant, there was an ADT dose-response relationship for risk of MCI: <5 years versus no use (HR, 1.08; 95% CI, 0.60-1.96) and ≥5 years versus not use (HR, 1.89; 95% CI, 0.83-4.27). CONCLUSION: ADT use among prostate cancer patients was not associated with an increased risk of developing MCI.


Asunto(s)
Antagonistas de Andrógenos/efectos adversos , Disfunción Cognitiva/epidemiología , Neoplasias de la Próstata/epidemiología , Anciano , Anciano de 80 o más Años , Envejecimiento , Humanos , Masculino , Registro Médico Coordinado , Neoplasias de la Próstata/tratamiento farmacológico
7.
Genet Med ; 22(12): 2120-2124, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32820244

RESUMEN

PURPOSE: Copy-number variants (CNVs) of uncertain clinical significance are routinely reported in a clinical setting only when exceeding predetermined reporting thresholds, typically based on CNV size. Given that very few genes are associated with triplosensitive phenotypes, it is not surprising that many interstitial duplications <1 Mb are found to be inherited and anticipated to be of limited or no clinical significance. METHODS: In an effort to further refine our reporting criteria to maximize diagnostic yield while minimizing the return of uncertain variants, we performed a retrospective analysis of all clinical microarray cases reported in a 10-year window. A total of 1112 reported duplications had parental follow-up, and these were compared by size, RefSeq gene content, and inheritance pattern. De novo origin was used as a rough proxy for pathogenicity. RESULTS: Approximately 6% of duplications 500 kb-1 Mb were de novo observations, compared with approximately 14% for 1-2 Mb duplications (p = 0.0005). On average, de novo duplications had higher gene counts than inherited duplications. CONCLUSION: Our data reveal limited diagnostic utility for duplications of uncertain significance <1 Mb. Considerations for revised reporting criteria are discussed and are applicable to CNVs detected by any genome-wide exploratory methodology, including exome/genome sequencing.


Asunto(s)
Variaciones en el Número de Copia de ADN , Exoma , Variaciones en el Número de Copia de ADN/genética , Análisis por Micromatrices , Estudios Retrospectivos , Secuenciación del Exoma
8.
Bioorg Med Chem ; 28(3): 115262, 2020 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-31882369

RESUMEN

The serotonin 5-HT7 G protein-coupled receptor (GPCR) is a proposed pharmacotherapeutic target for a variety of central and peripheral indications, albeit, there are no approved drugs selective for binding 5-HT7. We previously reported that a lead analog based on the 5-substituted-N,N-disubstituted-1,2,3,4-tetrahydronaphthalen-2-amine (5-substituted-2-aminotetralin, 5-SAT) scaffold binds with high affinity at the 5-HT7 GPCR, and can treat symptoms of autism in mouse models; subsequently, the lead was found to have high affinity at the 5-HT1A GPCR. Herein, we report the synthesis of novel 5-SAT analogs to develop a 3-dimensional quantitative structure-affinity relationship (3D-QSAR) at the human 5-HT7 receptor for comparison with similar studies at the highly homologous 5-HT1A receptor. We report 35 new 5-SAT ligands, some with very high affinity (Ki ≤ 1 nM) and stereoselectivity at 5-HT7 + or 5-HT1A receptors, several with modest selectivity (up to 12-fold) for binding at 5-HT7, and, several ligands with high selectivity (up to 40-fold) at the 5-HT1A receptor. 3D-QSAR results indicate that steric extensions at the C(5)-position improve selectivity for the 5-HT7 over 5-HT1A receptor, while steric and hydrophobic extensions at the chiral C(2)-amino position impart 5-HT1A selectivity. In silico receptor homology modeling studies, supplemented with molecular dynamics simulations and binding free energy calculations, were used to rationalize experimentally-determined receptor selectivity and stereoselective affinity results. The data from these studies indicate that the 5-SAT chemotype, previously shown to be safe and efficacious in rodent paradigms of neurodevelopmental and neuropsychiatric disorders, is amenable to structural modification to optimize affinity at serotonin 5-HT7 vs. 5-HT1A GPCRs, as may be required for successful clinical translation.


Asunto(s)
Relación Estructura-Actividad Cuantitativa , Receptor de Serotonina 5-HT1A/metabolismo , Receptores de Serotonina/metabolismo , Tetrahidronaftalenos/farmacología , Relación Dosis-Respuesta a Droga , Humanos , Ligandos , Modelos Moleculares , Estructura Molecular , Estereoisomerismo , Tetrahidronaftalenos/síntesis química , Tetrahidronaftalenos/química
9.
Echocardiography ; 37(11): 1792-1802, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-33012034

RESUMEN

INTRODUCTION: The right ventricle (RV) strain measured by speckle tracking (RVS) is an echocardiographic parameter used to assess RV function. We compared RVS to RV fractional area change (FAC%), tricuspid annular plane systolic excursion (TAPSE) and Doppler tissue imaging-derived peak systolic velocity (S') in the assessment of right ventricular (RV) systolic function measured using cardiac magnetic resonance imaging (MRI). METHODS: We enrolled consecutive patients who underwent cardiac MRI between Jan 2012 and Dec 2017 and a transthoracic echocardiogram (TTE) within 1 month of the MRI with no interval event. Baseline clinical characteristics and MRI parameters were extracted from chart review. Echocardiographic parameters were measured prospectively. TTE parameters including RVS, TAPSE, S', and FAC% were tested for accuracy to identify impaired RV EF (EF < 45% & <30%) using receiver operator curves. RESULTS: The study cohort included 500 patients with mean age 55 years ± 18 and peak tricuspid regurgitation velocity 2.7 ± 1.4 m/s. The area under ROC for RVS was 0.69 (95% CI 0.63-0.75) and 0.78 (95% CI 0.70-0.88) to predict RVEF < 45% & RVEF < 30%, respectively. The RV FAC% had second highest accuracy of predicting RVEF among all the TTE parameters tested in study. CONCLUSION: Right ventricular strain is the most accurate echocardiographic method to detect impaired right ventricular systolic function when using MRI as the gold standard.


Asunto(s)
Disfunción Ventricular Derecha , Función Ventricular Derecha , Ecocardiografía , Humanos , Imagen por Resonancia Magnética , Persona de Mediana Edad , Sensibilidad y Especificidad , Volumen Sistólico , Disfunción Ventricular Derecha/diagnóstico por imagen
10.
Anal Bioanal Chem ; 411(12): 2493-2509, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30911800

RESUMEN

Inhalation of Bacillus anthracis spores can cause a rapidly progressing fatal infection. B. anthracis secretes three protein toxins: lethal factor (LF), edema factor (EF), and protective antigen (PA). EF and LF may circulate as free or PA-bound forms. Both free EF (EF) and PA-bound-EF (ETx) have adenylyl cyclase activity converting ATP to cAMP. We developed an adenylyl cyclase activity-based method for detecting and quantifying total EF (EF+ETx) in plasma. The three-step method includes magnetic immunocapture with monoclonal antibodies, reaction with ATP generating cAMP, and quantification of cAMP by isotope-dilution HPLC-MS/MS. Total EF was quantified from 5PL regression of cAMP vs ETx concentration. The detection limit was 20 fg/mL (225 zeptomoles/mL for the 89 kDa protein). Relative standard deviations for controls with 0.3, 6.0, and 90 pg/mL were 11.7-16.6% with 91.2-99.5% accuracy. The method demonstrated 100% specificity in 238 human serum/plasma samples collected from unexposed healthy individuals, and 100% sensitivity in samples from 3 human and 5 rhesus macaques with inhalation anthrax. Analysis of EF in the rhesus macaques showed that it was detected earlier post-exposure than B. anthracis by culture and PCR. Similar to LF, the kinetics of EF over the course of infection were triphasic, with an initial rise (phase-1), decline (phase-2), and final rapid rise (phase-3). EF levels were ~ 2-4 orders of magnitude lower than LF during phase-1 and phase-2 and only ~ 6-fold lower at death/euthanasia. Analysis of EF improves early diagnosis and adds to our understanding of anthrax toxemia throughout infection. The LF/EF ratio may also indicate the stage of infection and need for advanced treatments.


Asunto(s)
Carbunco/patología , Antígenos Bacterianos/sangre , Bacillus anthracis/patogenicidad , Toxinas Bacterianas/sangre , Cromatografía Líquida de Alta Presión/métodos , Infecciones del Sistema Respiratorio/patología , Espectrometría de Masas en Tándem/métodos , Toxemia/patología , Adenosina Trifosfato/metabolismo , Animales , Carbunco/sangre , Estudios de Casos y Controles , AMP Cíclico/biosíntesis , Progresión de la Enfermedad , Ensayo de Inmunoadsorción Enzimática , Humanos , Límite de Detección , Macaca mulatta , Reacción en Cadena de la Polimerasa , Infecciones del Sistema Respiratorio/sangre , Toxemia/sangre , Toxemia/microbiología
11.
Radiographics ; 38(6): 1823-1832, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30303781

RESUMEN

The term never event in medicine was originally coined by Kenneth W. Kizer, MD, MPH, former chief executive officer of the National Quality Forum, to describe particularly shocking medical errors that should never occur, such as wrong-site surgery or death associated with introduction of a metallic object into the MRI area. With time, the National Quality Forum's list of never events, or "serious reportable events," has been expanded to include adverse events that are unambiguous, serious, and usually preventable. In this article, the never event framework has been used to describe (a) the errors that may occur in an imaging department that are serious and usually preventable with a review of the causative factors and (b) strategies to eliminate and reduce the adverse effects of these avoidable errors. These errors are often rooted in communication breakdowns and can only be eliminated with a true shift to a culture of open reporting and patient safety. ©RSNA, 2018.


Asunto(s)
Comunicación , Errores Diagnósticos/prevención & control , Diagnóstico por Imagen/normas , Errores Médicos/prevención & control , Garantía de la Calidad de Atención de Salud , Servicio de Radiología en Hospital/normas , Administración de la Seguridad/normas , Humanos , Cultura Organizacional , Seguridad del Paciente , Estados Unidos
13.
Int J Geriatr Psychiatry ; 33(8): 1114-1120, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29873112

RESUMEN

OBJECTIVE: To determine the cross-sectional and longitudinal associations between diabetes treatment type and cognitive outcomes among type II diabetics. METHODS: We examined the association between metformin use, as compared to other diabetic treatment (ie, insulin, other oral medications, and diet/exercise) and cognitive test performance and mild cognitive impairment (MCI) diagnosis among 508 cognitively unimpaired at baseline type II diabetics enrolled in the Mayo Clinic Study of Aging. We created propensity scores to adjust for treatment effects. We used multivariate linear and logistic regression models to investigate the cross-sectional association between treatment type and cognitive test z scores, respectively. Mixed effects models and competing risk regression models were used to determine the longitudinal association between treatment type and change in cognitive test z scores and risk of developing incident MCI. RESULTS: In linear regression analyses adjusted for age, sex, education, body mass index, APOE ε4, insulin treatment, medical comorbidities, number of medications, duration of diabetes, and propensity score, we did not observe an association between metformin use and cognitive test performance. Additionally, we did not observe an association between metformin use and cognitive test performance over time (median = 3.7-year follow-up). Metformin was associated with an increased risk of MCI (subhazard ratio (SHR) = 2.75; 95% CI = 1.64, 4.63, P < .001). Similarly, other oral medications (SHR = 1.96; 95% CI = 1.19, 3.25; P = .009) and insulin (SHR = 3.17; 95% CI = 1.27, 7.92; P = .014) use were also associated with risk of MCI diagnosis. CONCLUSIONS: These findings suggest that metformin use, as compared to management of diabetes with other treatments, is not associated with cognitive test performance. However, metformin was associated with incident MCI diagnosis.


Asunto(s)
Disfunción Cognitiva/inducido químicamente , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hipoglucemiantes/efectos adversos , Metformina/efectos adversos , Anciano , Anciano de 80 o más Años , Índice de Masa Corporal , Cognición/fisiología , Estudios Transversales , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/psicología , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Análisis de Regresión
14.
Handb Exp Pharmacol ; 252: 227-260, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29532180

RESUMEN

Recent, well-controlled - albeit small-scale - clinical trials show that serotonergic psychedelics, including psilocybin and lysergic acid diethylamide, possess great promise for treating psychiatric disorders, including treatment-resistant depression. Additionally, fresh results from a deluge of clinical neuroimaging studies are unveiling the dynamic effects of serotonergic psychedelics on functional activity within, and connectivity across, discrete neural systems. These observations have led to testable hypotheses regarding neural processing mechanisms that contribute to psychedelic effects and therapeutic benefits. Despite these advances and a plethora of preclinical and clinical observations supporting a central role for brain serotonin 5-HT2A receptors in producing serotonergic psychedelic effects, lingering and new questions about mechanisms abound. These chiefly pertain to molecular neuropharmacology. This chapter is devoted to illuminating and discussing such questions in the context of preclinical experimental approaches for studying mechanisms of action of serotonergic psychedelics, classic and new.


Asunto(s)
Alucinógenos/farmacología , Trastornos Mentales/tratamiento farmacológico , Receptor de Serotonina 5-HT2A/efectos de los fármacos , Animales , Encéfalo/efectos de los fármacos , Evaluación Preclínica de Medicamentos , Humanos , Dietilamida del Ácido Lisérgico/farmacología , Psilocibina/farmacología
15.
Alzheimers Dement ; 14(8): 989-997, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29626426

RESUMEN

INTRODUCTION: We examined and compared plasma phospho-tau181 (pTau181) and total tau: (1) across the Alzheimer's disease (AD) clinical spectrum; (2) in relation to brain amyloid ß (Aß) positron emission tomography (PET), tau PET, and cortical thickness; and (3) as a screening tool for elevated brain Aß. METHODS: Participants included 172 cognitively unimpaired, 57 mild cognitively impaired, and 40 AD dementia patients with concurrent Aß PET (Pittsburgh compound B), tau PET (AV1451), magnetic resonance imaging, plasma total tau, and pTau181. RESULTS: Plasma total tau and pTau181 levels were higher in AD dementia patients than those in cognitively unimpaired. Plasma pTau181 was more strongly associated with both Aß and tau PET. Plasma pTau181 was a more sensitive and specific predictor of elevated brain Aß than total tau and was as good as, or better than, the combination of age and apolipoprotein E (APOE). DISCUSSION: Plasma pTau181 may have utility as a biomarker of AD pathophysiology and as a noninvasive screener for elevated brain Aß.


Asunto(s)
Enfermedad de Alzheimer/diagnóstico por imagen , Péptidos beta-Amiloides/metabolismo , Disfunción Cognitiva/diagnóstico por imagen , Tomografía de Emisión de Positrones , Proteínas tau/metabolismo , Anciano , Enfermedad de Alzheimer/metabolismo , Disfunción Cognitiva/metabolismo , Femenino , Humanos , Imagen por Resonancia Magnética , Fosforilación , Proteínas tau/sangre
16.
J Biol Chem ; 291(42): 22021-22029, 2016 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-27555325

RESUMEN

The protective antigen (PA) moiety of anthrax toxin binds to cellular receptors and mediates the translocation of the two enzymatic moieties of the toxin to the cytosol. Two PA receptors are known, with capillary morphogenesis protein 2 (CMG2) being the more important for pathogenesis and tumor endothelial marker 8 (TEM8) playing a minor role. The C-terminal PA domain 4 (PAD4) has extensive interactions with the receptors and is required for binding. Our previous study identified PAD4 variants having enhanced TEM8 binding specificity. To obtain PA variants that selectively bind to CMG2, here we performed phage display selections using magnetic beads having bound CMG2. We found that PA residue isoleucine 656 plays a critical role in PA binding to TEM8 but has a much lesser effect on PA binding to CMG2. We further characterized the role of residue 656 in distinguishing PA binding to CMG2 versus TEM8 by substituting it with the other 19 amino acids. Of the resulting variants, PA I656Q and PA I656V had significantly reduced activity on TEM8-expressing CHO cells but maintained their activity on CMG2-expressing CHO cells. The preference of these PA mutants for CMG2 over TEM8 was further demonstrated using mouse embryonic fibroblast cells and mice deficient in the CMG2 and/or the TEM8 receptors. The structural basis of the alterations in the receptor binding activities of these mutants is also discussed.


Asunto(s)
Antígenos Bacterianos/metabolismo , Bacillus anthracis/metabolismo , Toxinas Bacterianas/metabolismo , Biomarcadores de Tumor/metabolismo , Mutación Missense , Receptores de Péptidos/metabolismo , Sustitución de Aminoácidos , Animales , Antígenos Bacterianos/genética , Bacillus anthracis/genética , Toxinas Bacterianas/genética , Biomarcadores de Tumor/genética , Células CHO , Cricetinae , Cricetulus , Embrión de Mamíferos , Fibroblastos , Ratones , Proteínas de Microfilamentos , Unión Proteica , Dominios Proteicos , Receptores de Superficie Celular , Receptores de Péptidos/genética , Relación Estructura-Actividad
19.
Am J Obstet Gynecol ; 217(3): 344.e1-344.e6, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28502758

RESUMEN

BACKGROUND: Postpartum hemorrhage is a major cause of maternal morbidity and mortality, but the association between postpartum hemorrhage and hospital length of stay has not been rigorously investigated. OBJECTIVE: We explored the impact of postpartum hemorrhage on hospital length of stay and inpatient mortality, as these outcomes have both clinical and economic significance. STUDY DESIGN: We performed a retrospective analysis using data from the National Inpatient Sample database during the 2012 through 2013 time period. Deliveries were classified as postpartum hemorrhage due to uterine atony, nonatonic postpartum hemorrhage, or not complicated by postpartum hemorrhage (nonpostpartum hemorrhage). Average length of stay and inpatient mortality rates were compared between groups. RESULTS: Over the study interval, postpartum hemorrhage occurred in 3% of deliveries. Among deliveries complicated by postpartum hemorrhage, 76.6% were attributed to uterine atony and 23.4% were nonatonic. Women with nonatonic postpartum hemorrhage had the highest average length of stay (3.67 days) followed by atonic postpartum hemorrhage (2.98 days) and nonpostpartum hemorrhage (2.63 days); P < .001, all comparisons. Inpatient mortality rate of nonatonic postpartum hemorrhage over the entire study period was 104 per 100,000 compared to 019 per 100,000 for atonic postpartum hemorrhage and 3 per 100,000 for nonpostpartum hemorrhage deliveries (P < .001). CONCLUSION: From 2012 through 2013, women with postpartum hemorrhage experienced significantly longer length of stay and higher inpatient mortality rates than women without postpartum hemorrhage, largely attributable to nonatonic causes of postpartum hemorrhage. As hospital length of stay and inpatient mortality are important outcomes from both clinical and societal perspectives, interventions to reduce morbidity and mortality related to postpartum hemorrhage may simultaneously facilitate delivery of more cost-effective care and improve both maternal and population health.


Asunto(s)
Mortalidad Hospitalaria , Tiempo de Internación/estadística & datos numéricos , Hemorragia Posparto/epidemiología , Adulto , Femenino , Humanos , Embarazo , Estudios Retrospectivos , Estados Unidos/epidemiología , Inercia Uterina/epidemiología
20.
J Biol Chem ; 290(10): 6584-95, 2015 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-25564615

RESUMEN

Anthrax disease is caused by a toxin consisting of protective antigen (PA), lethal factor, and edema factor. Antibodies against PA have been shown to be protective against the disease. Variable domains of camelid heavy chain-only antibodies (VHHs) with affinity for PA were obtained from immunized alpacas and screened for anthrax neutralizing activity in macrophage toxicity assays. Two classes of neutralizing VHHs were identified recognizing distinct, non-overlapping epitopes. One class recognizes domain 4 of PA at a well characterized neutralizing site through which PA binds to its cellular receptor. A second neutralizing VHH (JKH-C7) recognizes a novel epitope. This antibody inhibits conversion of the PA oligomer from "pre-pore" to its SDS and heat-resistant "pore" conformation while not preventing cleavage of full-length 83-kDa PA (PA83) by cell surface proteases to its oligomer-competent 63-kDa form (PA63). The antibody prevents endocytosis of the cell surface-generated PA63 subunit but not preformed PA63 oligomers formed in solution. JKH-C7 and the receptor-blocking VHH class (JIK-B8) were expressed as a heterodimeric VHH-based neutralizing agent (VNA2-PA). This VNA displayed improved neutralizing potency in cell assays and protected mice from anthrax toxin challenge with much better efficacy than the separate component VHHs. The VNA protected virtually all mice when separately administered at a 1:1 ratio to toxin and protected mice against Bacillus anthracis spore infection. Thus, our studies show the potential of VNAs as anthrax therapeutics. Due to their simple and stable nature, VNAs should be amenable to genetic delivery or administration via respiratory routes.


Asunto(s)
Carbunco/inmunología , Anticuerpos Antibacterianos/inmunología , Antígenos Bacterianos/inmunología , Toxinas Bacterianas/inmunología , Cadenas Pesadas de Inmunoglobulina/inmunología , Animales , Carbunco/microbiología , Carbunco/patología , Carbunco/terapia , Anticuerpos Antibacterianos/administración & dosificación , Bacillus anthracis/inmunología , Bacillus anthracis/patogenicidad , Toxinas Bacterianas/antagonistas & inhibidores , Camélidos del Nuevo Mundo/inmunología , Epítopos/inmunología , Humanos , Ratones , Esporas/inmunología , Esporas/patogenicidad
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