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1.
BMJ Case Rep ; 16(12)2023 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-38160023

RESUMEN

A newborn male infant was pale, hypotonic, and had respiratory distress after delivery. Venous cord blood gas revealed a severe metabolic acidosis. His initial examination was consistent with moderate encephalopathy and laboratory testing uncovered severe congenital anaemia (haematocrit 0.127 L/L). He met the clinical criteria for therapeutic hypothermia (TH) and required red blood cell transfusions, but due to the severity of his anaemia, an exchange transfusion was favoured to prevent transfusion-associated circulatory overload. There are no previous reports of these procedures completed in tandem, but the benefits were perceived to outweigh the risks. During the 72 hours of TH, the infant received an isovolumetric partial exchange transfusion and tolerated both treatments without any adverse clinical events.Kleihauer-Betke testing detected a massive chronic fetomaternal haemorrhage with 475 mL (164 mL/kg) of blood. A brain MRI completed prior to discharge was normal. At 6 months of age, he is growing and developing normally.


Asunto(s)
Anemia , Transfusión Fetomaterna , Hipotermia Inducida , Embarazo , Femenino , Recién Nacido , Humanos , Masculino , Transfusión Fetomaterna/diagnóstico , Hemorragia , Recambio Total de Sangre
2.
J Perinatol ; 43(11): 1349-1356, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37667005

RESUMEN

Red blood cell (RBC) transfusions are common in neonates requiring intensive care. Recent studies have compared restricted versus liberal transfusion guidelines, but limitations exist on evaluations of outcomes in populations that never required a transfusion compared to those receiving any transfusion. Although there are well-established risks associated with RBC transfusions, new data has emerged that suggests additional clinically relevant associations, including adverse neurodevelopmental outcomes, donor sex differences, and inflammation or immunosuppression. Further research is needed to delineate the magnitude of these risks and to further improve the safety of transfusions. The goal of this review is to highlight underappreciated, yet clinically important risks associated with neonatal RBC transfusions and to introduce several areas in which neonates may uniquely benefit from alterations in practice.


Asunto(s)
Cuidados Críticos , Transfusión de Eritrocitos , Femenino , Recién Nacido , Humanos , Masculino , Transfusión de Eritrocitos/efectos adversos
3.
Heliyon ; 9(1): e12844, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36691535

RESUMEN

Three microwave-assisted digestion procedures, followed by analysis of digestates employing inductively coupled mass spectrometry (ICP-MS) were evaluated for use in the determination of elements at trace and ultra-trace levels in PM2.5 samples. Digestion procedure 1 used 2.5 mL HNO3 (65%) at 200 °C. Procedure 2, consisted of a two-stage digestion step at 200 °C with 2.5 mL HNO3 (65%) and 3 µL HF (48%) followed by 24 µL H3BO3 (5%). A 10-fold increase in the amounts of HF and H3BO3 was used for procedure 3. The addition of HF/H3BO3 was carried out to aid the dissolution of silicate matrices and refractory compounds. The digestions were carried out using PTFE ultra-trace inserts which increased the sample throughput threefold. The addition of small quantities of HF resulted in the effective solubilisation of Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Sr, Cd, Sb and Pb. The optimal method using HNO3/HF/H3BO3 digestion as in procedure 3 showed recovery efficiency greater than 70% for all elements. The validated method was applied to quantify the elemental content of indoor and outdoor PM2.5 (with samples <0.5 mg) at an urban background site in Malta.

4.
J Pediatr ; 246: 191-198.e4, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35460701

RESUMEN

OBJECTIVE: To examine the association between antibiotic and acid suppressant prescriptions in the first 2 years of life and subsequent treatment for childhood psychiatric disorders. STUDY DESIGN: This was a retrospective cohort study of children born between October 2001 and September 2012 in the Military Health System enrolled in TRICARE past age 2 years and within 35 days of birth, with an initial hospital stay <7 days, and without psychotropic agents dispensed during the first 2 years of life. Exposure was defined as a filled prescription for an antibiotic or acid suppressant before age 2 years, and the outcome was defined as a filled prescription for a psychotropic agent after age 2 years. RESULTS: For the 804 920 patients (51% males and 49% female) composing the study population, the mean age at first psychotropic prescription was 6.8 years. A total of 24 176 children (3%) were prescribed a proton pump inhibitor (PPI), 79 243 (10%) were prescribed a histamine-2 receptor antagonist (H2RA), and 607 348 (76%) were prescribed an antibiotic during the first 2 years of life. The adjusted hazard ratio (aHR) of a psychotropic prescription was significantly increased in children prescribed any H2RA (1.79; 95% CI, 1.63-1.96), PPI (1.47; 95% CI, 1.26-1.71), or antibiotic (1.71; 95% CI, 1.59-1.84). The aHR of psychotropic prescriptions increased commensurately with each additional antibiotic class added and with each additional class of medication (H2RA, PPI, or antibiotics) prescribed. CONCLUSIONS: Children prescribed antibiotic and acid suppressants in the first 2 years of life have a significant increase in future prescriptions for psychotropics, with a dose-related effect observed. This association represents a potential risk of early exposure to antibiotics and acid suppressants.


Asunto(s)
Antibacterianos , Antagonistas de los Receptores H2 de la Histamina , Antibacterianos/uso terapéutico , Niño , Preescolar , Femenino , Antagonistas de los Receptores H2 de la Histamina/uso terapéutico , Humanos , Masculino , Prescripciones , Inhibidores de la Bomba de Protones/uso terapéutico , Psicotrópicos/uso terapéutico , Estudios Retrospectivos
5.
Mil Med ; 187(11-12): e1483-e1486, 2022 10 29.
Artículo en Inglés | MEDLINE | ID: mdl-34679170

RESUMEN

The coronavirus disease 2019 (COVID-19) global pandemic has posed unique challenges to healthcare providers that work in austere environments. Military healthcare providers advise commanders on endemic disease risk, prevention, and management during field training exercises. Healthcare workers are at increased risk of exposure to infectious pathogens. We present a case of a military healthcare provider who presented with fever, cough, and fatigue during the COVID-19 global pandemic that was diagnosed with a primary pulmonary coccidioidal infection. Treatment after appropriate diagnosis consisted of supportive care. Respiratory and pain symptoms resolved by 2 months post-diagnosis. Although COVID-19 must be closely monitored in the field training environment, it is important to maintain a high index of suspicion of endemic infectious diseases as a potential etiology for respiratory illnesses.


Asunto(s)
COVID-19 , Pandemias , Humanos , Pandemias/prevención & control , SARS-CoV-2 , Personal de Salud , Fiebre/etiología , Dolor en el Pecho/etiología
6.
Proc Natl Acad Sci U S A ; 118(28)2021 07 13.
Artículo en Inglés | MEDLINE | ID: mdl-34260400

RESUMEN

Understanding the potential of nanomaterials (NMs) to cross the blood-brain barrier (BBB), as a function of their physicochemical properties and subsequent behavior, fate, and adverse effect beyond that point, is vital for evaluating the neurological effects arising from their unintentional entry into the brain, which is yet to be fully explored. This is not only due to the complex nature of the brain but also the existing analytical limitations for characterization and quantification of NMs in the complex brain environment. By using a fit-for-purpose analytical workflow and an in vitro BBB model, we show that the physiochemical properties of metallic NMs influence their biotransformation in biological matrices, which in turn modulates the transport form, efficiency, amounts, and pathways of NMs through the BBB and, consequently, their neurotoxicity. The data presented here will support in silico modeling and prediction of the neurotoxicity of NMs and facilitate the tailored design of safe NMs.


Asunto(s)
Barrera Hematoencefálica/metabolismo , Metales/química , Nanoestructuras/química , Astrocitos/metabolismo , Biotransformación , Encéfalo/irrigación sanguínea , Células Endoteliales/metabolismo , Exocitosis , Humanos , Microvasos/citología , Modelos Biológicos , Permeabilidad , Transcitosis
7.
Mater Sci Eng C Mater Biol Appl ; 126: 112158, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34082963

RESUMEN

The growing threat of bacterial resistance to antibiotics is driving an increasing need for new antimicrobial strategies. This work demonstrates the potential of magnesium oxychloride cements (MOC) to be used as inorganic antimicrobial biomaterials for bone augmentation. An injectable formulation was identified at a powder to liquid ratio of 1.4 g mL-1, with an initial setting time below 30 mins and compressive strength of 35 ± 9 MPa. Supplementation with Ag3PO4 to enhance the antimicrobial efficacy of MOC was explored, and shown via real time X-ray diffraction to retard the formation of hydrated oxychloride phases by up to 30%. The antimicrobial efficacy of MOC was demonstrated in vitro against Staphylococcus aureus and Pseudomonas aeruginosa, forming zones of inhibition and significantly reducing viability in broth culture. Enhanced efficacy was seen for silver doped formulations, with complete eradication of detectable viable colonies within 3 h, whilst retaining the cytocompatibility of MOC. Investigating the antimicrobial mode of action revealed that Mg and Ag release and elevated pH contributed to MOC efficacy. Sustained silver release was demonstrated over 14 days, suggesting the Ag3PO4 modified formulation offers two mechanisms of infection treatment, combining the inherent antimicrobial properties of MOC with controlled release of inorganic antimicrobials.


Asunto(s)
Antiinfecciosos , Magnesio , Antibacterianos/farmacología , Antiinfecciosos/farmacología , Cementos para Huesos , Suplementos Dietéticos , Magnesio/farmacología , Ensayo de Materiales , Fosfatos , Compuestos de Plata
8.
Environ Sci Technol ; 55(13): 8721-8729, 2021 07 06.
Artículo en Inglés | MEDLINE | ID: mdl-34110809

RESUMEN

Reliable chemical identification of specific polymers in environmental samples represents a major challenge in plastic research, especially with the wide range of commercial polymers available, along with variable additive mixtures. Thermogravimetric analysis-Fourier transform infrared-gas chromatography-mass spectrometry (TGA-FTIR-GC-MS) offers a unique characterization platform that provides both physical and chemical properties of the analyzed polymers. This study presents a library of 11 polymers generated using virgin plastics and post-consumer products. TGA inflection points and mass of remaining residues following pyrolysis, in some cases, proved to be indicative of the polymer type. FTIR analysis of the evolved gas was able to differentiate between all but polypropylene (PP) and polyethylene (PE). Finally, GC-MS was able to differentiate between the unique chemical fingerprints of all but one polymer in the library. This library was then used to characterize real environmental samples of mesoplastics collected from beaches in the U.K. and South Africa. Unambiguous identification of the polymer types was achieved, with PE being the most frequently detected polymer and with South African samples indicating variations that potentially resulted from aging and weathering.


Asunto(s)
Plásticos , Polímeros , Análisis de Fourier , Cromatografía de Gases y Espectrometría de Masas , Sudáfrica , Espectroscopía Infrarroja por Transformada de Fourier
9.
Sci Total Environ ; 720: 137470, 2020 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-32325566

RESUMEN

Particulate matter originated from traffic has attracted major interest over the last few years. The semi-volatile organic component of the particles may evaporate with dispersion away from the emission source, creating vapour which may oxidise to form secondary organic aerosol. Air samples were collected from a street canyon, the adjacent park and an urban background site during the winter-spring period in central London, UK. Emissions of semi-volatile organic compounds (SVOCs) and intermediate volatility organic compounds (IVOCs) ranging from C10 to C36 in both the gas phase and particle phase were measured by using thermal desorption coupled to comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (TD-GC × GC-ToF-MS). Main compound groups identified and quantified were grouped alkanes (n-alkanes and branched alkanes), monocyclic alkanes, bicyclic alkanes and monocyclic aromatics. The carbon preference index (CPI) of n-alkanes was estimated to distinguish the emission sources. Pearson correlations between I/SVOCs and traffic tracers (black carbon, NOx and benzene) in different locations were compared to analyse the influence of this emission source. The results indicate that while the major emission source at the roadside site is traffic, the lower correlations at background sites are indicative of other source contributions and/or differential reactivity of compounds. Gas-particle phase partitioning of n-alkanes is evaluated and compared between sites. The potential influence of gas phase I/SVOCs upon OH reactivity and secondary organic aerosol (SOA) formation is estimated and found to be relatively small.

10.
Tech Vasc Interv Radiol ; 22(3): 127-134, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31623752

RESUMEN

Intraductal biliary stones can result in significant acute and long-term complications. When patients' anatomy precludes more traditional management, the interventional radiologist may be called upon to provide well-established techniques for percutaneous biliary drainage and stone removal. This can be particularly challenging when the patient has excessively mobile, impacted, large or multiple stones. Percutaneous biliary endoscopy with adjunct interventional techniques can successfully treat these patients avoiding the patient dreaded "tube for life" scenario. Direct percutaneous visualization of the biliary tree can also diagnose and provide symptomatic relief for stone-mimicking pathologic conditions such as biliary tumors. This article will review the role, technique, and considerations for percutaneous biliary endoscopy and adjunct interventions in patients with isolated and complex, biliary stone disease and stone-mimicking pathologies.


Asunto(s)
Colelitiasis/terapia , Drenaje/métodos , Endoscopía del Sistema Digestivo/métodos , Radiografía Intervencional/métodos , Colelitiasis/diagnóstico por imagen , Diagnóstico Diferencial , Drenaje/efectos adversos , Drenaje/instrumentación , Endoscopía del Sistema Digestivo/efectos adversos , Endoscopía del Sistema Digestivo/instrumentación , Humanos , Selección de Paciente , Valor Predictivo de las Pruebas , Radiografía Intervencional/efectos adversos , Radiografía Intervencional/instrumentación , Factores de Riesgo , Resultado del Tratamiento
11.
Gut ; 68(1): 62-69, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30377188

RESUMEN

OBJECTIVE: Gut microbiota alterations are associated with obesity. Early exposure to medications, including acid suppressants and antibiotics, can alter gut biota and may increase the likelihood of developing obesity. We investigated the association of antibiotic, histamine-2 receptor antagonist (H2RA) and proton pump inhibitor (PPI) prescriptions during early childhood with a diagnosis of obesity. DESIGN: We performed a cohort study of US Department of Defense TRICARE beneficiaries born from October 2006 to September 2013. Exposures were defined as having any dispensed prescription for antibiotic, H2RA or PPI medications in the first 2 years of life. A single event analysis of obesity was performed using Cox proportional hazards regression. RESULTS: 333 353 children met inclusion criteria, with 241 502 (72.4%) children prescribed an antibiotic, 39 488 (11.8%) an H2RA and 11 089 (3.3%) a PPI. Antibiotic prescriptions were associated with obesity (HR 1.26; 95% CI 1.23 to 1.28). This association persisted regardless of antibiotic class and strengthened with each additional class of antibiotic prescribed. H2RA and PPI prescriptions were also associated with obesity, with a stronger association for each 30-day supply prescribed. The HR increased commensurately with exposure to each additional medication group prescribed. CONCLUSIONS: Antibiotics, acid suppressants and the combination of multiple medications in the first 2 years of life are associated with a diagnosis of childhood obesity. Microbiota-altering medications administered in early childhood may influence weight gain.


Asunto(s)
Antibacterianos/administración & dosificación , Microbioma Gastrointestinal/efectos de los fármacos , Antagonistas de los Receptores H2 de la Histamina/administración & dosificación , Obesidad/epidemiología , Inhibidores de la Bomba de Protones/administración & dosificación , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Estudios Retrospectivos , Factores de Riesgo , Estados Unidos/epidemiología
13.
Proc Math Phys Eng Sci ; 474(2220): 20180492, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30602933

RESUMEN

Diesel engine emissions are by far the largest source of nanoparticles in many urban atmospheres, in which they dominate the particle number count, and may present a significant threat to public health. This paper reviews knowledge of the composition and atmospheric properties of diesel exhaust particles, and exemplifies research in this field through a description of the FASTER project (Fundamental Studies of the Sources, Properties and Environmental Behaviour of Exhaust Nanoparticles from Road Vehicles) which studied the size distribution-and, in unprecedented detail, the chemical composition-of nanoparticles sampled from diesel engine exhaust. This information has been systematized and used to inform the development of computational modules that simulate the behaviour of the largely semi-volatile content of the nucleation mode particles, including consequent effects on the particle size distribution, under typical atmospheric conditions. Large-eddy model studies have informed a simpler characterization of flow around the urban built environment, and include aerosol processes. This modelling and engine-laboratory work have been complemented by laboratory measurements of vapour pressures, and the execution of two field measurement campaigns in London. The result is a more robust description of the dynamical behaviour on the sub-kilometre scale of diesel exhaust nanoparticles and their importance as an urban air pollutant.

14.
Inflamm Bowel Dis ; 23(10): 1777-1782, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28696957

RESUMEN

BACKGROUND: Urolithiasis is rare in pediatric patients. All patients with inflammatory bowel disease (IBD) have an increased risk of urolithiasis, but this risk is poorly quantified in children. The objective of this study is to evaluate the association of IBD with urolithiasis, assess surgical outcomes, and analyze the financial burden for children hospitalized with urolithiasis and comorbid IBD. METHODS: The triennial Healthcare Cost and Utilization Project Kids' Inpatient Database for years 1997 to 2012 was used to evaluate the association between urolithiasis and IBD in hospitalized, nonpregnant children ages 5 to 20 years old. Billing codes were used to define conditions. Logistic regression analysis quantified the association between IBD types and urolithiasis. Length of hospital stay, costs, procedures, and complications were compared between urolithiasis patients with and without IBD. RESULTS: Among 8,828,522 hospital admissions, we identified 36,771 admissions with a primary diagnosis of urolithiasis. Of these cases, 230 were associated with Crohn's disease (odds ratios, 1.99; 95% confidence interval, 1.74-2.27) and 102 with ulcerative colitis (odds ratio, 1.63; 95% confidence interval, 1.34-1.99). Urolithiasis patients with ulcerative colitis, but not Crohn's disease, had significantly increased length of stay and costs. Patients with either IBD had a decreased number of urologic procedures. CONCLUSIONS: The diagnosis of urolithiasis in pediatric patients is associated with IBD, and those with ulcerative colitis have longer hospital stays and greater costs. Patients with IBD have fewer urologic procedures associated with their urolithiasis diagnosis.


Asunto(s)
Colitis Ulcerosa/epidemiología , Enfermedad de Crohn/epidemiología , Urolitiasis/complicaciones , Adolescente , Niño , Preescolar , Estudios Transversales , Bases de Datos Factuales , Femenino , Costos de la Atención en Salud , Hospitalización , Humanos , Modelos Logísticos , Masculino , Oportunidad Relativa , Estados Unidos/epidemiología , Adulto Joven
15.
Abdom Radiol (NY) ; 42(11): 2609-2614, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28474176

RESUMEN

PURPOSE: To determine if hepatic venous pressure gradient (HVPG) correlates with advanced hepatic fibrosis, as a complement to transjugular (transvenous) core needle liver biopsy. MATERIALS AND METHODS: After institutional review board approval, a retrospective review was conducted on 340 patients who underwent transjugular (transvenous) core needle liver biopsy with concurrent pressure measurements between 6/1/2007 and 6/1/2013. Spearman correlation and linear regression were performed. A receiver operating characteristic (ROC) curve was created and sensitivity, specificity, predictive values and likelihood ratios were calculated. RESULTS: Indications included hepatitis C, abnormal liver function tests, non-alcoholic steatohepatitis, autoimmune hepatitis, and cirrhosis, among others. Biopsies showed stage 1 or 2 fibrosis in 15.6% each, stage 3 fibrosis in 21.6%, stage 4 fibrosis in 40.7%, and no fibrosis in 6.5%. Mean HVPG was 6.5 mm Hg (SD 5.0) with a range of 0-26 mm Hg. Spearman correlation coefficient for association between HVPG and fibrosis stage was 0.561 (p < 0.001). R2 on linear regression was 0.247 (p < 0.001). ROC curve for the prediction of stage 4 fibrosis had an area under the curve of 0.79 (95% CI 0.73-0.85). HVPG of ≥6 mm Hg had a sensitivity of 71.3%, specificity of 79.6%, positive predictive value of 70.5%, negative predictive value of 80.2%, positive likelihood ratio of 3.49 (95% CI 2.45-4.97) and negative likelihood ratio of 0.36 (95% CI 0.26-0.50) for diagnosis of stage 4 fibrosis. CONCLUSIONS: HVPG correlates with stage 4 (advanced) hepatic fibrosis.


Asunto(s)
Hipertensión Portal/patología , Cirrosis Hepática/patología , Adulto , Anciano , Anciano de 80 o más Años , Biopsia con Aguja Gruesa , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad
16.
Cardiovasc Intervent Radiol ; 39(11): 1658-1661, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27402306

RESUMEN

Intravascular papillary endothelial hyperplasia (IPEH), often referred to as Masson's tumor, is a benign non-neoplastic vascular lesion of the skin and subcutaneous tissues. Although it is rare, knowledge of the existence of IPEH is important as it can mimic other benign and malignant tumors, most notably angiosarcoma. IPEH remains an incompletely understood entity; however, most consider it to be the result of reactive endothelial proliferation following thrombus formation within a vessel, vascular malformation, or adjacent to a vessel. In this article, we report a case of IPEH arising within an arteriovenous malformation of the radial artery and present accompanying multimodality imaging and pathology figures. We will also describe the clinical presentation, pathophysiology, histology, imaging features, and management of IPEH.


Asunto(s)
Arteria Radial/diagnóstico por imagen , Arteria Radial/patología , Malformaciones Vasculares/diagnóstico por imagen , Malformaciones Vasculares/patología , Neoplasias Vasculares/diagnóstico por imagen , Neoplasias Vasculares/patología , Adulto , Diagnóstico Diferencial , Humanos , Hiperplasia , Imagen por Resonancia Magnética , Masculino , Arteria Radial/cirugía , Ultrasonografía Doppler , Malformaciones Vasculares/cirugía , Neoplasias Vasculares/cirugía
17.
Faraday Discuss ; 189: 69-84, 2016 07 18.
Artículo en Inglés | MEDLINE | ID: mdl-27137954

RESUMEN

A number of major research questions remain concerning the sources and properties of road traffic generated particulate matter. A full understanding of the composition of primary vehicle exhaust aerosol and its contribution to secondary organic aerosol (SOA) formation still remains elusive, and many uncertainties exist relating to the semi-volatile component of the particles. Semi-Volatile Organic Compounds (SVOCs) are compounds which partition directly between the gas and aerosol phases under ambient conditions. The SVOCs in engine exhaust are typically hydrocarbons in the C15-C35 range, and are largely uncharacterised because they are unresolved by traditional gas chromatography, forming a large hump in the chromatogram referred to as Unresolved Complex Mixture (UCM). In this study, thermal desorption coupled to comprehensive Two Dimensional Gas-Chromatography Time-of-Flight Mass-Spectrometry (TD-GC × GC-ToF-MS) was exploited to characterise and quantify the composition of SVOCs from the exhaust emission. Samples were collected from the exhaust of a diesel engine, sampling before and after a diesel oxidation catalyst (DOC), while testing at steady state conditions. Engine exhaust was diluted with air and collected using both filter and impaction (nano-MOUDI), to resolve total mass and size resolved mass respectively. Adsorption tubes were utilised to collect SVOCs in the gas phase and they were then analysed using thermal desorption, while particle size distribution was evaluated by sampling with a DMS500. The SVOCs were observed to contain predominantly n-alkanes, branched alkanes, alkyl-cycloalkanes, alkyl-benzenes, PAHs and various cyclic aromatics. Particle phase compounds identified were similar to those observed in engine lubricants, while vapour phase constituents were similar to those measured in fuels. Preliminary results are presented illustrating differences in the particle size distribution and SVOCs composition when collecting samples with and without a DOC. The results indicate that the DOC tested is of very limited efficiency, under the studied engine operating conditions, for removal of SVOCs, especially at the upper end of the molecular weight range.

18.
Physiol Rep ; 4(8)2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27117800

RESUMEN

Magnesium is one of the most abundant cations in the human body and plays a key role as a metabolic enzyme cofactor and regulatory ion for neurons and cardiomyocytes. Hypomagnesemia due to isolated primary renal magnesium wasting is a rare clinical condition typically associated with neurological hyperexcitability. Exercise-related gastrointestinal symptoms are caused by ischemic, mechanical, or neurohormonal changes. The role of hypomagnesemia in gastrointestinal symptoms is not well understood. We present a case of a 15-year-old male who presented with exercise-induced abdominal pain, nausea, and vomiting, who was found to have profound hypomagnesemia and inappropriately elevated fractional excretion of magnesium (FEMg). Testing for multiple intrinsic and extrinsic etiologies of renal magnesium wasting was inconclusive. He was diagnosed with primary renal magnesium wasting and his symptoms resolved acutely with intravenous magnesium sulfate and with long-term oral magnesium chloride. Primary renal magnesium wasting is a rare clinical entity that can cause extreme hypomagnesemia. It has not been associated previously with exercise-induced gastrointestinal symptoms. The effects of hypomagnesemia on the human gastrointestinal tract are not well established. This case offers unique insights into the importance of magnesium homeostasis in the gastrointestinal tract. Exercise-induced splanchnic hypoperfusion may contribute to gastrointestinal symptoms observed in this chronically hypomagnesemic patient.


Asunto(s)
Ejercicio Físico , Defectos Congénitos del Transporte Tubular Renal/fisiopatología , Adolescente , Humanos , Masculino
19.
Anal Chem ; 88(8): 4211-20, 2016 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-26981641

RESUMEN

Although GC×GC-ToF-MS allows the separation of thousands of peaks, many of these peaks are not positively identified owing to the lack of mass spectral library data and/or standard materials, leading to a substantial amount of information being inaccessible. The fragmentation patterns of molecules in mass spectrometers using electron impact ionization at 70 eV can be useful for molecule identification, provided a match is available in a published EI MS library, but are indistinguishable for many isomeric organic compounds (for example, linear and branched alkanes). Lower ionization energies have been exploited leading to organic compounds being ionized with lower excess internal energy and less fragmentation, retaining the molecular ion and maximizing its relative signal. This has enabled the identification of a large number of isomeric organic compounds, both aliphatic and aromatic, between C12-C36, in the previously unresolved complex mixture (UCM) of two motor oil samples. This technique also demonstrates problems associated with separation of coeluting isomers, particularly for the n-alkanes, which are routinely measured by 1D GC/MS and may be overestimated, due to coelution. As a consequence retention times in 2 dimensions and mass spectra at variable ionization energies are shown to give unparalleled power to identify specific isomers.

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