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1.
Reproduction ; 165(4): 347-362, 2023 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-36633493

RESUMEN

In brief: Maternal obesity can impair metabolism in the embryo and the resulting offspring. This study shows that metabolic disruptions through α-ketoglutarate may link altered metabolism with epigenetic changes in embryos. Abstract: Maternal obesity can impair offspring metabolic health; however, the precise mechanism underpinning programming is unknown. Ten-Eleven translocase (TET) enzymes demethylate DNA using the TCA cycle intermediary α-ketoglutarate and may be involved in programming offspring health. Whether TETs are disrupted by maternal obesity is unknown. Five to six week-old C57Bl/6 female mice were fed a control diet (CD; 6% fat, n = 175) or a high-fat diet (HFD; 21% fat, n = 158) for 6 weeks. After superovulation, oocytes were collected for metabolic assessment, or females were mated and zygotes were cultured for embryo development, fetal growth, and assessment of global DNA methylation (5-methylcytosine (5mC), 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxycytosine (5caC)) in the two-cell embryo. Zygotes collected from superovulated CBAF1 females were cultured in media containing α-ketoglutarate (0, 1.4, 3.5, or 14.0 mM) or with 2-hydroxyglutarate (2HG) (0 or 20 mM), a competitive inhibitor of α-ketoglutarate, with methylation and blastocyst differentiation assessed. After HFD, oocytes showed increased pyruvate oxidation and intracellular ROS, with no changes in Tet3 expression, while two-cell embryo global 5hmC DNA methylation was reduced and 5fC increased. Embryos cultured with 1.4 mM α-ketoglutarate had decreased two-cell 5mC, while 14.0 mM α-ketoglutarate increased the 5hmC:5mC ratio. In contrast, supplementation with 20 mM 2HG increased 5mC and decreased 5fC:5mC and 5caC:5mC ratios. α-ketoglutarate up to 3.5 mM did not alter embryo development, while culturing in 14.0 mM α-ketoglutarate blocked development at the two-cell. Culture with 2HG delayed embryo development past the four-cell and decreased blastocyst total cell number. In conclusion, disruptions in metabolic intermediates in the preimplantation embryo may provide a link between maternal obesity and programming offspring for ill health.


Asunto(s)
Metilación de ADN , Obesidad Materna , Animales , Femenino , Humanos , Ratones , Embarazo , 5-Metilcitosina/metabolismo , Citosina/metabolismo , Dieta Alta en Grasa , Ácidos Cetoglutáricos/farmacología , Obesidad Materna/metabolismo , Cigoto/metabolismo
2.
Mol Reprod Dev ; 90(7): 621-633, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-35986715

RESUMEN

The mitochondrial genome resides in the mitochondria present in nearly all cell types. The porcine (Sus scrofa) mitochondrial genome is circa 16.7 kb in size and exists in the multimeric format in cells. Individual cell types have different numbers of mitochondrial DNA (mtDNA) copy number based on their requirements for ATP produced by oxidative phosphorylation. The oocyte has the largest number of mtDNA of any cell type. During oogenesis, the oocyte sets mtDNA copy number in order that sufficient copies are available to support subsequent developmental events. It also initiates a program of epigenetic patterning that regulates, for example, DNA methylation levels of the nuclear genome. Once fertilized, the nuclear and mitochondrial genomes establish synchrony to ensure that the embryo and fetus can complete each developmental milestone. However, altering the oocyte's mtDNA copy number by mitochondrial supplementation can affect the programming and gene expression profiles of the developing embryo and, in oocytes deficient of mtDNA, it appears to have a positive impact on the embryo development rates and gene expression profiles. Furthermore, mtDNA haplotypes, which define common maternal origins, appear to affect developmental outcomes and certain reproductive traits. Nevertheless, the manipulation of the mitochondrial content of an oocyte might have a developmental advantage.


Asunto(s)
ADN Mitocondrial , Oocitos , ADN Mitocondrial/genética , Oocitos/metabolismo , Mitocondrias/genética , Mitocondrias/metabolismo , Oogénesis/genética , Desarrollo Embrionario/genética
3.
Int J Mol Sci ; 24(8)2023 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-37108708

RESUMEN

Oocytes can be supplemented with extra copies of mitochondrial DNA (mtDNA) to enhance developmental outcome. Pigs generated through supplementation with mtDNA derived from either sister (autologous) or third-party (heterologous) oocytes have been shown to exhibit only minor differences in growth, physiological and biochemical assessments, and health and well-being do not appear affected. However, it remains to be determined whether changes in gene expression identified during preimplantation development persisted and affected the gene expression of adult tissues indicative of high mtDNA copy number. It is also unknown if autologous and heterologous mtDNA supplementation resulted in different patterns of gene expression. Our transcriptome analyses revealed that genes involved in immune response and glyoxylate metabolism were commonly affected in brain, heart and liver tissues by mtDNA supplementation. The source of mtDNA influenced the expression of genes associated with oxidative phosphorylation (OXPHOS), suggesting a link between the use of third-party mtDNA and OXPHOS. We observed a significant difference in parental allele-specific imprinted gene expression in mtDNA-supplemented-derived pigs, with shifts to biallelic expression with no effect on expression levels. Overall, mtDNA supplementation influences the expression of genes in important biological processes in adult tissues. Consequently, it is important to determine the effect of these changes on animal development and health.


Asunto(s)
Variaciones en el Número de Copia de ADN , ADN Mitocondrial , Animales , Porcinos , ADN Mitocondrial/metabolismo , Oocitos/metabolismo , Mitocondrias/metabolismo , Sus scrofa/metabolismo
4.
Proc Natl Acad Sci U S A ; 116(19): 9263-9268, 2019 05 07.
Artículo en Inglés | MEDLINE | ID: mdl-31010930

RESUMEN

The motion and mixing of granular media are observed in several contexts in nature, often displaying striking similarities to liquids. Granular dynamics occur in geological phenomena and also enable technologies ranging from pharmaceuticals production to carbon capture. Here, we report the discovery of a family of gravitational instabilities in granular particle mixtures subject to vertical vibration and upward gas flow, including a Rayleigh-Taylor (RT)-like instability in which lighter grains rise through heavier grains in the form of "fingers" and "granular bubbles." We demonstrate that this RT-like instability arises due to a competition between upward drag force increased locally by gas channeling and downward contact forces, and thus the physical mechanism is entirely different from that found in liquids. This gas channeling mechanism also generates other gravitational instabilities: the rise of a granular bubble which leaves a trail of particles behind it and the cascading branching of a descending granular droplet. These instabilities suggest opportunities for patterning within granular mixtures.

5.
Sensors (Basel) ; 22(6)2022 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-35336477

RESUMEN

With the ongoing digitalization of industry, imaging sensors are becoming increasingly important for industrial process control. In addition to direct imaging techniques such as those provided by video or infrared cameras, tomographic sensors are of interest in the process industry where harsh process conditions and opaque fluids require non-intrusive and non-optical sensing techniques. Because most tomographic sensors rely on complex and often time-multiplexed excitation and measurement schemes and require computationally intensive image reconstruction, their application in the control of highly dynamic processes is often hindered. This article provides an overview of the current state of the art in fast process tomography and its potential for use in industry.


Asunto(s)
Procesamiento de Imagen Asistido por Computador , Tomografía Computarizada por Rayos X , Procesamiento de Imagen Asistido por Computador/métodos
6.
Magn Reson Med ; 79(6): 3256-3266, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-28983969

RESUMEN

PURPOSE: The goal of this study was to devise a gradient system for MRI in humans that reconciles cutting-edge gradient strength with rapid switching and brings up the duty cycle to 100% at full continuous amplitude. Aiming to advance neuroimaging and short-T2 techniques, the hardware design focused on the head and the extremities as target anatomies. METHODS: A boundary element method with minimization of power dissipation and stored magnetic energy was used to design anatomy-targeted gradient coils with maximally relaxed geometry constraints. The design relies on hollow conductors for high-performance cooling and split coils to enable dual-mode gradient amplifier operation. With this approach, strength and slew rate specifications of either 100 mT/m with 1200 mT/m/ms or 200 mT/m with 600 mT/m/ms were reached at 100% duty cycle, assuming a standard gradient amplifier and cooling unit. RESULTS: After manufacturing, the specified values for maximum gradient strength, maximum switching rate, and field geometry were verified experimentally. In temperature measurements, maximum local values of 63°C were observed, confirming that the device can be operated continuously at full amplitude. Testing for peripheral nerve stimulation showed nearly unrestricted applicability in humans at full gradient performance. In measurements of acoustic noise, a maximum average sound pressure level of 132 dB(A) was determined. In vivo capability was demonstrated by head and knee imaging. Full gradient performance was employed with echo planar and zero echo time readouts. CONCLUSION: Combining extreme gradient strength and switching speed without duty cycle limitations, the described system offers unprecedented options for rapid and short-T2 imaging. Magn Reson Med 79:3256-3266, 2018. © 2017 International Society for Magnetic Resonance in Medicine.


Asunto(s)
Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , Encéfalo/diagnóstico por imagen , Diseño de Equipo , Humanos , Rodilla/diagnóstico por imagen , Masculino , Dinámicas no Lineales , Fantasmas de Imagen , Temperatura
7.
J Clin Monit Comput ; 31(1): 167-175, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26686691

RESUMEN

The nature of hemodynamic instability typical of circulatory shock is not well understood, but an improved interpretation of its dynamic features could help in the management of critically ill patients. The objective of this work was to introduce new metrics for the analysis of arterial blood pressure (ABP) in order to characterize the risk of catastrophic outcome in splanchnic arterial occlusion (SAO) shock. Continuous ABP (fs = 1 kHz) was measured in rats during experimental SAO shock, which induced a fatal pressure drop (FPD) in ABP. The FPD could either be slow (SFPD) or fast (FFPD), with the latter causing cardiovascular collapse. Time series of mean arterial pressure, systolic blood pressure and heart period were derived from ABP. The sample asymmetry-based algorithm Heart Rate Characteristics was adapted to compute the Heart Period Characteristics (HPC) and the Blood Pressure Characteristics (BPC). Baroreflex sensitivity (BRS) was assessed by means of a bivariate model. The approach to FPD of the animals who collapsed (FFPD) was characterized by higher BRS in the low frequency band versus SFPD animals (0.36 ± 0.15 vs. 0.19 ± 0.12 ms/mmHg, p value = 0.0196), bradycardia as indicated by the HPC (0.76 ± 0.57 vs. 1.94 ± 1.27, p value = 0.0179) and higher but unstable blood pressure as indicated by BPC (3.02 ± 2.87 vs. 1.47 ± 1.29, p value = 0.0773). The HPC and BPC indices demonstrated promise as potential clinical markers of hemodynamic instability and impending cardiovascular collapse, and this animal study suggests their test in data from intensive care patients.


Asunto(s)
Determinación de la Presión Sanguínea , Presión Sanguínea , Choque/fisiopatología , Circulación Esplácnica , Algoritmos , Animales , Barorreflejo , Enfermedades Cardiovasculares/fisiopatología , Cuidados Críticos , Corazón/fisiopatología , Frecuencia Cardíaca , Hemodinámica , Humanos , Unidades de Cuidados Intensivos , Masculino , Modelos Estadísticos , Ratas , Ratas Wistar , Riesgo , Factores de Tiempo , Resultado del Tratamiento
8.
J Pediatr Gastroenterol Nutr ; 62(2): 317-27, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26230900

RESUMEN

OBJECTIVES: Parents of children with autism spectrum disorders (ASDs) often report gastrointestinal (GI) dysfunction in their children. The objectives of the present study were to determine whether infants at high risk for developing ASD (ie, siblings of children diagnosed as having ASD) show greater prevalence of GI problems and whether this prevalence is associated with diet and age at weaning from breast milk. METHODS: Using questionnaires, diet history and GI problems were tracked prospectively and retrospectively in 57 high-risk infants and for comparison in 114 low-risk infants (infants from families without ASD history). RESULTS: In low-risk infants, prevalence of GI symptoms, in aggregate, did not vary with diet or age of weaning. By contrast, high-risk infants with GI symptoms were weaned earlier than those without symptoms (P < 0.04), and high-risk infants showed greater prevalence of GI symptoms, in aggregate, on a no breast milk diet than on an exclusive breast milk diet (P < 0.017). Constipation, in particular, was more prevalent in high-risk infants compared with low-risk infants (P = 0.01), especially on a no breast milk diet (P = 0.002). High-risk infants who completed weaning earlier than 6 months showed greater prevalence of constipation (P = 0.001) and abdominal distress (P = 0.004) than those fully weaned after 6 months. CONCLUSIONS: The greater prevalence of GI symptoms in high-risk infants suggests that GI dysfunction during early infant development may be a part of the ASD endophenotype. Late weaning and exclusive breast milk were associated with protection against GI symptoms in high-risk infants.


Asunto(s)
Trastorno del Espectro Autista , Trastorno Autístico , Lactancia Materna , Estreñimiento/prevención & control , Dieta , Leche Humana , Destete , Adulto , Trastorno del Espectro Autista/complicaciones , Trastorno Autístico/complicaciones , Preescolar , Estreñimiento/complicaciones , Enfermedades Gastrointestinales/complicaciones , Enfermedades Gastrointestinales/prevención & control , Humanos , Lactante , Persona de Mediana Edad , Fenotipo , Encuestas y Cuestionarios , Adulto Joven
9.
J Pediatr Gastroenterol Nutr ; 59(3): 365-73, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24840512

RESUMEN

OBJECTIVES: Fat is digested in the intestine into free fatty acids (FFAs), which are detergents and therefore toxic to cells at micromolar concentration. The mucosal barrier protects cells in the adult intestine, but this barrier may not be fully developed in premature infants. Lipase-digested infant formula, but not fresh human milk, has elevated FFAs and is cytotoxic to intestinal cells, and therefore could contribute to intestinal injury in necrotizing enterocolitis (NEC), but even infants exclusively fed breast milk may develop NEC. Our objective was to determine whether stored milk and milk from donor milk (DM) banks could also become cytotoxic, especially after digestion. METHODS: We exposed cultured rat intestinal epithelial cells or human neutrophils to DM and milk collected fresh and stored at 4°C or -20°C for up to 12 weeks and then treated for 2 hours (37°C) with 0.1 or 1 mg/mL pancreatic lipase and/or trypsin and chymotrypsin. RESULTS: DM and milk stored 3 days (at 4°C or -20°C) and then digested were cytotoxic. Storage at -20°C for 8 and 12 weeks resulted in an additional increase in cytotoxicity. Protease digestion decreased, but did not eliminate cell death. CONCLUSIONS: Present storage practices may allow milk to become cytotoxic and contribute to intestinal damage in NEC.


Asunto(s)
Digestión , Ácidos Grasos no Esterificados/metabolismo , Almacenamiento de Alimentos , Lipasa/metabolismo , Leche Humana/metabolismo , Animales , Muerte Celular/efectos de los fármacos , Células Cultivadas , Quimotripsina/metabolismo , Células Epiteliales , Ácidos Grasos no Esterificados/farmacología , Humanos , Mucosa Intestinal/citología , Bancos de Leche Humana , Leche Humana/química , Neutrófilos , Ratas , Temperatura , Factores de Tiempo , Tripsina/metabolismo
10.
Phys Chem Chem Phys ; 16(6): 2715-26, 2014 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-24390268

RESUMEN

Cation diffusion was investigated in La0.6Sr0.4CoO3-δ (LSC) thin films on (100) yttria stabilized zirconia in the temperature range 625-800 °C. Isotopic ((86)Sr) and elemental tracers (Fe, Sm) were used to establish diffusion profiles of the cations in bi- and multi-layered thin films. The profiles were analyzed by time of flight-secondary ion mass spectrometry (ToF-SIMS). Grain and grain boundary diffusion coefficients of the cations were determined for LSC thin films with columnar grains - diffusion along grain boundaries is shown to be about three orders of magnitude faster than in grains. This could be verified for thin films with different grain size. A- and B-site cations showed very similar temperature dependencies with activation energies of ∼3.5 eV for bulk and ∼4.1 eV for grain boundary diffusion. The importance of cation diffusivities for surface segregation of Sr and thus for a major degradation mechanism of LSC cathodes in solid oxide fuel cells is discussed.

11.
Solid State Ion ; 256: 38-44, 2014 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-27570330

RESUMEN

The oxygen exchange and diffusion properties of La0.6Sr0.4CoO3 - Î´ thin films on yttria stabilized zirconia were analyzed by impedance spectroscopy and 18O tracer experiments. The investigations were performed on the same thin film samples and at the same temperature (400 °C) in order to get complementary information by the two methods. Electrochemical impedance spectroscopy can reveal resistive and capacitive contributions of such systems, but an exact interpretation of the spectra of complex oxide electrodes is often difficult from impedance data alone. It is shown that additional isotope exchange depth profiling can significantly help interpreting impedance spectra by giving reliable information on the individual contribution and exact location of resistances (surface, electrode bulk, interface). The measurements also allowed quantitative comparison of electrode polarization resistances obtained by different methods.

12.
Shock ; 61(6): 869-876, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38319752

RESUMEN

ABSTRACT: Combat casualty care can be complicated by transport times exceeding the "golden hour," with intervention and resuscitation limited to what the medic can carry. Pharmaceutical albumin comes highly saturated with nonesterified fatty acids (NEFAs). We recently showed that treatment with 25% bovine serum albumin (BSA) loaded with oleic acid, but not NEFA-free BSA, improved survival for hours after severe hemorrhage and often eliminated the need for resuscitation in rats. However, it was unknown whether pharmaceutical albumin, derived from human sources and loaded with caprylic acid (CA), would have the same benefits. We compared adjunct treatment with oleic acid-saturated BSA, CA-saturated BSA, pharmaceutical human serum albumin, or a no-albumin control in a similar rat hemorrhagic shock model to determine whether the three NEFA-albumin groups provided the same benefits relative to control. We found almost no significant differences among the NEFA-albumin groups in any measure. Mortality in controls was too low to allow for detection of improvement in survival, but NEFA-albumin groups had significantly improved hemodynamics, lactate clearance, and greatly reduced fluid requirements compared with controls. Contrary to expectations of "dehydration," 25% albumins shifted little additional fluid into the vasculature. Rather, they restored protein to the autotransfusion fluid. Nonesterified fatty acids-albumin did not worsen lung permeability, but we observed a loss of circulating protein suggesting it may have increased overall vascular permeability. Our findings suggest that, though imperfect, 25% human serum albumin could be a solution for resuscitation in austere conditions requiring prolonged field care.


Asunto(s)
Hemodinámica , Resucitación , Albúmina Sérica , Choque Hemorrágico , Animales , Ratas , Resucitación/métodos , Humanos , Hemodinámica/efectos de los fármacos , Choque Hemorrágico/terapia , Choque Hemorrágico/tratamiento farmacológico , Masculino , Albúmina Sérica/uso terapéutico , Ratas Sprague-Dawley , Modelos Animales de Enfermedad , Heridas y Lesiones/terapia , Heridas y Lesiones/tratamiento farmacológico , Albúmina Sérica Humana , Albúmina Sérica Bovina , Ácido Oléico , Ácidos Grasos no Esterificados/sangre , Caprilatos/farmacología , Servicios Médicos de Urgencia , Hemorragia/tratamiento farmacológico , Hemorragia/terapia
13.
iScience ; 26(2): 105956, 2023 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-36711242

RESUMEN

Introducing extra mitochondrial DNA (mtDNA) into oocytes at fertilization can rescue poor quality oocytes. However, supplementation alters DNA methylation and gene expression profiles of preimplantation embryos. To determine if these alterations impacted offspring, we introduced mtDNA from failed-to-mature sister (autologous) or third party (heterologous) oocytes into mature oocytes and transferred zygotes into surrogates. Founders exhibited significantly greater daily weight gain (heterologous) and growth rates (heterologous and autologous) to controls. In weaners, cholesterol, bilirubin (heterologous and autologous), anion gap, and lymphocyte count (autologous) were elevated. In mature pigs, potassium (heterologous) and bicarbonate (autologous) were altered. mtDNA and imprinted gene analyses did not reveal aberrant profiles. Neither group exhibited gross anatomical, morphological, or histopathological differences that would lead to clinically significant lesions. Female founders were fertile and their offspring exhibited modified weight and height gain, biochemical, and hematological profiles. mtDNA supplementation induced minor differences that did not affect health and well-being.

14.
Pediatr Res ; 72(6): 560-7, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23007028

RESUMEN

BACKGROUND: Premature infants fed formula are more likely to develop necrotizing enterocolitis (NEC) than those who are breastfed, but the mechanisms of intestinal necrosis in NEC and protection by breast milk are unknown. We hypothesized that after lipase digestion, formula, but not fresh breast milk, contains levels of unbound free fatty acids (FFAs) that are cytotoxic to intestinal cells. METHODS: We digested multiple term and preterm infant formulas or human milk with pancreatic lipase, proteases (trypsin and chymotrypsin), lipase + proteases, or luminal fluid from a rat small intestine and tested FFA levels and cytotoxicity in vitro on intestinal epithelial cells, endothelial cells, and neutrophils. RESULTS: Lipase digestion of formula, but not milk, caused significant death of neutrophils (ranging from 47 to 99% with formulas vs. 6% with milk) with similar results in endothelial and epithelial cells. FFAs were significantly elevated in digested formula vs. milk and death from formula was significantly decreased with lipase inhibitor pretreatment, or treatments to bind FFAs. Protease digestion significantly increased FFA binding capacity of formula and milk but only enough to decrease cytotoxicity from milk. CONCLUSION: FFA-induced cytotoxicity may contribute to the pathogenesis of NEC.


Asunto(s)
Muerte Celular , Enterocolitis Necrotizante/etiología , Alimentos Infantiles , Leche Humana , Animales , Bovinos , Enterocolitis Necrotizante/patología , Humanos , Técnicas In Vitro , Recién Nacido , Recien Nacido Prematuro
15.
Shock ; 55(6): 832-841, 2021 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-32991552

RESUMEN

ABSTRACT: Decompensation is a major prehospital threat to survival from trauma/hemorrhage shock (T/HS) after controlling bleeding. We recently showed higher than expected mortality from a combat-relevant rat model of T/HS (27 mL/kg hemorrhage) with tourniquet (TQ) and permissive hypotensive resuscitation (PHR) with Plasmalyte. Mortality and fluid requirements were reduced by resuscitation with 25% albumin presaturated with oleic acid (OA-sat) compared with fatty-acid -free albumin or Plasmalyte. The objective of this follow-up analysis was to determine the role of decompensation and individual compensatory mechanisms in those outcomes. We observed two forms of decompensation: slow (accelerating fluid volumes needed to maintain blood pressure) and acute (continuous fluid administration unable to prevent pressure drop). Combined incidence of decompensation was 71%. Nearly all deaths (21 of 22) were caused by acute decompensations that began as slow decompensations. The best hemodynamic measure for predicting acute decompensation was diastolic arterial pressure. Decompensation was due to vascular decompensation rather than loss of cardiac performance. Albumin concentration was lower in decompensating groups, suggesting decreased stressed volume, which may explain the association of low albumin on admission with poor outcomes after trauma. Our findings suggest that acute decompensation may be common after trauma and severe hemorrhage treated with TQ and PHR and OA-sat albumin may benefit early survival and reduce transfusion volume by improving venous constriction and preventing decompensation.


Asunto(s)
Albúminas/administración & dosificación , Ácidos Grasos/administración & dosificación , Resucitación , Choque Hemorrágico/terapia , Torniquetes , Animales , Terapia Combinada , Modelos Animales de Enfermedad , Masculino , Ratas , Ratas Sprague-Dawley
16.
Shock ; 53(2): 179-188, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-30829851

RESUMEN

Military prehospital care for hemorrhage is often characterized by use of tourniquets (TQ) and permissive hypotensive resuscitation (PHR) with crystalloids or colloids, but these treatments have not been previously combined in an animal model. Although albumin resuscitation solutions have been tested, the potential effects of nonesterified fatty acids (NEFAs) bound to albumin have not been evaluated in vivo, and few studies have investigated concentrated albumin solutions to reduce fluid requirements. We created a militarily relevant rat model of trauma and hemorrhagic shock (T/HS) (27 mL/kg hemorrhage) with TQ and PHR. We investigated the ability of resuscitation with concentrated (250 mg/mL) albumin, followed by Plasmalyte as needed to maintain PHR, to reduce fluid volumes (vs. Plasmalyte alone, N = 17). Albumin was free of nonesterified fatty acids (N = 15) or saturated with oleic acid (OA; N = 13). The model resulted in high (53%) mortality within 3 h of injury. Only OA-saturated albumin was able to significantly reduce mortality (from 47% to 8%) and fluid requirements (from 56 to 6 mL/kg) compared to Plasmalyte alone. Plasma NEFA-binding capacity was saturated earliest in the OA-saturated albumin group. Likewise, OA-saturated albumin tended to increase cell-free hemoglobin in the broncheoalveolar lavage fluid, which was significantly associated with survival. Our findings suggest incorporating TQ and PHR in T/HS models may result in high mortality and fluid requirements and that OA-saturated albumin, but not NEFA-free albumin or Plasmalyte alone, may provide a benefit to early survival and resuscitation volume, though a hemolytic mechanism may have later consequences, so caution is advised.


Asunto(s)
Hipotensión/sangre , Hipotensión/terapia , Choque Hemorrágico/terapia , Torniquetes , Albúminas , Animales , Ácidos Grasos no Esterificados/sangre , Hemodinámica/fisiología , Estimación de Kaplan-Meier , Masculino , Ratas , Ratas Sprague-Dawley , Choque Hemorrágico/sangre
17.
Semin Pediatr Surg ; 27(1): 3-10, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29275814

RESUMEN

Better means to diagnose and define necrotizing enterocolitis are needed to guide clinical practice and research. Adequacy of Bell's staging system for clinical practice and clarity of cases used in NEC clinical datasets has been a topic of controversy for some time. This article provides reasons why a better global definition for NEC is needed and offers a simple alternative bedside definition for preterm NEC called the "Two out of Three" rule. Some argue that biomarkers may fill knowledge gaps and provide greater precision in defining relevant features of a clinical disease like NEC. NEC biomarkers include markers of inflammation, intestinal dysfunction, hematologic changes, and clinical features. Development and reporting of NEC biomarkers should be guided by the FDA's BEST Consensus resource, "Biomarkers, EndpointS, & other Tools" and consistently report metrics so that studies can be compared and results pooled. Current practice in the NICU would be enhanced by clinical tools that effectively inform the clinical team that a baby is at increasing risk of NEC. Ideally, these tools will incorporate both clinical information about the baby as well as molecular signals that are indicative of NEC. While meaningful biomarkers for NEC and clinical tools exist, translation into practice is mediocre.


Asunto(s)
Enterocolitis Necrotizante/diagnóstico , Enfermedades del Prematuro/diagnóstico , Biomarcadores/metabolismo , Toma de Decisiones Clínicas/métodos , Enterocolitis Necrotizante/metabolismo , Humanos , Recién Nacido , Recien Nacido Prematuro , Enfermedades del Prematuro/metabolismo , Radiografía , Índice de Severidad de la Enfermedad
18.
Shock ; 27(3): 296-304, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17304111

RESUMEN

Recent evidence indicates that shock is accompanied by a failure of the mucosal barrier in the intestine and entry of pancreatic digestive enzymes into the wall of the intestine. To investigate the formation of cytotoxic mediators produced by enzymatic digestion of the intestine, we applied homogenates of rat small intestinal wall to human neutrophils and used flow cytometry measurements of propidium iodide uptake to determine cytotoxicity. We show that homogenates of the small intestine after ischemia by occlusion of the superior mesenteric and celiac arteries for 3 h, but not without ischemia, are cytotoxic. Digestion of homogenates of nonischemic intestinal wall with purified trypsin, chymotrypsin, or elastase, proteases normally present in the intestinal lumen, yielded cytotoxic mediators. Before cell death, we saw cell damage in the form of bleb formation and flow cytometry measurements of cell size changes due to blebbing. Cytotoxicity was prevented by serine protease inhibition with phenylmethylsulfonyl fluoride (PMSF) before, but not after proteolytic digestion of the wall homogenates, indicating that enzymatic action of proteases on the homogenate is necessary for cytotoxicity. Cytotoxicity of wall homogenates digested by enzymes in the fluid collected from the lumen of the intestine was greater than digests by the individual purified proteases. Cytotoxicity is undetectable if digestive enzymes in the luminal fluid are inhibited with a combination of enzyme inhibitors PMSF and 6-amidino-2-naphthyl p-guanidinobenzoate dimethanesulfonate before addition of wall homogenates. Passage of digested intestinal wall homogenates across a hydrophobic glass-fiber filter reduced cytotoxicity. Furthermore, we found that luminal fluid itself may be cytotoxic, possibly because of digestion of ingested food. To test whether digested food can be cytotoxic, we homogenized rat food and digested it in vitro with chymotrypsin or endogenous enzymes in luminal fluid. Cytotoxicity was significantly increased after digestion of food by luminal fluid compared with luminal fluid or undigested food. These results indicate the presence of a previously unknown mechanism for hemorrhagic necrosis in shock.


Asunto(s)
Citotoxinas/metabolismo , Intestinos/enzimología , Páncreas/enzimología , Animales , Apoptosis , Quimotripsina/química , Quimotripsina/metabolismo , Citometría de Flujo/métodos , Humanos , Inflamación , Isquemia/metabolismo , Masculino , Neutrófilos/metabolismo , Ratas , Ratas Wistar , Choque
19.
Shock ; 48(4): 449-458, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28328710

RESUMEN

The use of albumin for resuscitation has not proven as beneficial in human trials as expected from numerous animal studies. One explanation could be the practice of adding fatty acid (FA) during manufacture of pharmaceutical albumin. During ischemia, unbound free FAs (FFA) in the circulation could potentially induce cellular damage. We hypothesized that albumins with higher available binding capacities (ABC) for FFAs may prevent that damage. Therefore, we developed a technique to measure ABC, determined if pharmaceutical human serum albumin (HSA) has decreased ABC compared with FA-free bovine serum albumin (BSA), and if binding capacity would affect hemolysis when blood is mixed with exogenous FFA at levels similar to those observed in shock. The new assay used exogenous oleic acid (OA), glass fiber filtration, and a FFA assay kit. RBC hemolysis was determined by mixing 0 to 5 mM OA with PBS, HSA, FA-free BSA, or FA-saturated BSA and measuring plasma hemoglobin after incubation with human blood. 5% HSA contained 4.7±0.2 mM FFA, leaving an ABC of 5.0 ±â€Š0.6 mM, compared with FA-free BSAs ABC of 7.0 ±â€Š1.3 mM (P < 0.024). Hemolysis after OA was reduced with FA-free BSA but increased with FA-saturated BSA. HSA provided intermediate results. 25% solutions of FA-free BSA and HSA were more protective, while 25% FA-saturated BSA was more damaging than 5% solutions. These findings suggest that increased FA saturation may reverse albumin's potential benefit to lessen cellular damage and may explain, at least in part, its failure in human trauma studies.


Asunto(s)
Sustitutos Sanguíneos , Eritrocitos/metabolismo , Ácidos Grasos , Hemólisis/efectos de los fármacos , Resucitación , Albúmina Sérica Humana , Choque/terapia , Sustitutos Sanguíneos/análisis , Sustitutos Sanguíneos/química , Sustitutos Sanguíneos/farmacología , Eritrocitos/patología , Ácidos Grasos/análisis , Ácidos Grasos/química , Ácidos Grasos/farmacología , Humanos , Albúmina Sérica Humana/análisis , Albúmina Sérica Humana/química , Albúmina Sérica Humana/farmacología , Choque/metabolismo
20.
Sci Adv ; 3(9): e1701879, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28929140

RESUMEN

Granular dynamics govern earthquakes, avalanches, and landslides and are of fundamental importance in a variety of industries ranging from energy to pharmaceuticals to agriculture. Nonetheless, our understanding of the underlying physics is poor because we lack spatially and temporally resolved experimental measurements of internal grain motion. We introduce a magnetic resonance imaging methodology that provides internal granular velocity measurements that are four orders of magnitude faster compared to previous work. The technique is based on a concerted interplay of scan acceleration and materials engineering. Real-time probing of granular dynamics is explored in single- and two-phase systems, providing fresh insight into bubble dynamics and the propagation of shock waves upon impact of an intruder. We anticipate that the methodology outlined here will enable advances in understanding the propagation of seismic activity, the jamming transition, or the rheology and dynamics of dense suspensions.

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