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1.
J Infect Dis ; 214(2): 182-8, 2016 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-26740276

RESUMEN

BACKGROUND: In the northeastern United States, tick-borne diseases are a major public health concern. In controlled studies, a single springtime application of acaricide has been shown to kill 68%-100% of ticks. Although public health authorities recommend use of acaricides to control tick populations in yards, the effectiveness of these pesticides to prevent tick bites or human tick-borne diseases is unknown. METHODS: We conducted a 2-year, randomized, double-blinded, placebo-controlled trial among 2727 households in 3 northeastern states. Households received a single springtime barrier application of bifenthrin or water according to recommended practices. Tick drags were conducted 3-4 weeks after treatment on 10% of properties. Information on human-tick encounters and tick-borne diseases was collected through monthly surveys; reports of illness were validated by medical record review. RESULTS: Although the abundance of questing ticks was significantly lower (63%) on acaricide-treated properties, there was no difference between treatment groups in human-tick encounters, self-reported tick-borne diseases, or medical-record-validated tick-borne diseases. CONCLUSIONS: Used as recommended, acaricide barrier sprays do not significantly reduce the household risk of tick exposure or incidence of tick-borne disease. Measures for preventing tick-borne diseases should be evaluated against human outcomes to confirm effectiveness.


Asunto(s)
Acaricidas/administración & dosificación , Mordeduras de Garrapatas/prevención & control , Enfermedades por Picaduras de Garrapatas/prevención & control , Garrapatas/efectos de los fármacos , Garrapatas/crecimiento & desarrollo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Niño , Preescolar , Método Doble Ciego , Composición Familiar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , New England , Placebos/administración & dosificación , Piretrinas/administración & dosificación , Mordeduras de Garrapatas/epidemiología , Enfermedades por Picaduras de Garrapatas/epidemiología , Adulto Joven
2.
Emerg Infect Dis ; 21(10): 1794-9, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26402378

RESUMEN

An Ehrlichia muris-like (EML) pathogen was detected among 4 patients in Minnesota and Wisconsin during 2009. We characterized additional cases clinically and epidemiologically. During 2004-2013, blood samples from 75,077 patients from all 50 United States were tested by PCR from the groEL gene for Ehrlichia spp. and Anaplasma phagocytophilum. During 2007-2013, samples from 69 (0.1%) patients were positive for the EML pathogen; patients were from 5 states: Indiana (1), Michigan (1), Minnesota (33), North Dakota (3), and Wisconsin (31). Most (64%) patients were male; median age was 63 (range 15-94) years; and all 69 patients reported likely tick exposure in Minnesota or Wisconsin. Fever, malaise, thrombocytopenia, and lymphopenia were the most common symptoms. Sixteen (23%) patients were hospitalized (median 4 days); all recovered, and 96% received doxycycline. Infection with the EML pathogen should be considered for persons reporting tick exposure in Minnesota or Wisconsin.


Asunto(s)
Anaplasma phagocytophilum/patogenicidad , Anaplasmataceae/patogenicidad , Pruebas Serológicas/métodos , Garrapatas/parasitología , Zoonosis/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anaplasma phagocytophilum/genética , Anaplasmataceae/genética , Animales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Minnesota/epidemiología , Wisconsin/epidemiología , Zoonosis/transmisión , Zoonosis/virología
3.
J Pharmacol Exp Ther ; 352(1): 77-89, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25347994

RESUMEN

Activation of M1 macrophages in nonalcoholic steatohepatitis (NASH) is produced by several external or endogenous factors: inflammatory stimuli, oxidative stress, and cytokines are known. However, any direct role of oxidative stress in causing M1 polarization in NASH has been unclear. We hypothesized that CYP2E1-mediated oxidative stress causes M1 polarization in experimental NASH, and that nitric oxide (NO) donor administration inhibits CYP2E1-mediated inflammation with concomitant attenuation of M1 polarization. Because CYP2E1 takes center stage in these studies, we used a toxin model of NASH that uses a ligand and a substrate of CYP2E1 for inducing NASH. Subsequently, we used a methionine and choline-deficient diet-induced rodent NASH model where the role of CYP2E1 in disease progression has been shown. Our results show that CYP2E1 causes M1 polarization bias, which includes a significant increase in interleukin-1ß (IL-1ß) and IL-12 in both models of NASH, whereas CYP2E1-null mice or diallyl sulfide administration prevented it. Administration of gadolinium chloride (GdCl3), a macrophage toxin, attenuated both the initial M1 response and the subsequent M2 response, showing that the observed increase in cytokine levels is primarily from macrophages. Based on the evidence of an adaptive NO increase, the NO donor administration in vivo that mechanistically inhibited CYP2E1 catalyzed the oxidative stress during the entire study in NASH-abrogated M1 polarization and NASH progression. The results obtained show the association of CYP2E1 in M1 polarization, and that inhibition of CYP2E1 catalyzed oxidative stress by an NO donor (DETA NONOate [(Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate]) can be a promising therapeutic strategy in NASH.


Asunto(s)
Citocromo P-450 CYP2E1/metabolismo , Progresión de la Enfermedad , Macrófagos/efectos de los fármacos , Compuestos Nitrosos/farmacología , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Estrés Oxidativo/efectos de los fármacos , Animales , Citocromo P-450 CYP2E1/genética , Regulación de la Expresión Génica/efectos de los fármacos , Peroxidación de Lípido/efectos de los fármacos , Hígado/efectos de los fármacos , Hígado/metabolismo , Macrófagos/citología , Macrófagos/inmunología , Masculino , Ratones , Ratones Obesos , Donantes de Óxido Nítrico/farmacología , Donantes de Óxido Nítrico/uso terapéutico , Compuestos Nitrosos/uso terapéutico , Enfermedad del Hígado Graso no Alcohólico/inmunología , Enfermedad del Hígado Graso no Alcohólico/patología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Tirosina/metabolismo
4.
Int J Biol Macromol ; 264(Pt 1): 130454, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38417758

RESUMEN

The demand for the functionalization of additive materials based on bacterial cellulose (BC) is currently high due to their potential applications across various sectors. The preparation of BC-based additive materials typically involves two approaches: in situ and ex situ. In situ modifications entail the incorporation of additive materials, such as soluble and dispersed substances, which are non-toxic and not essential for bacterial cell growth during the production process. However, these materials can impact the yield and self-assembly of BC. In contrast, ex situ modification occurs subsequent to the formation of BC, where the additive materials are not only adsorbed on the surface but also impregnated into the BC pellicle, while the BC slurry was homogenized with other additive materials and gelling agents to create composite films using the casting method. This review will primarily focus on the in situ and ex situ functionalization of BC then sheds light on the pivotal role of functionalized BC in advancing biomedical technologies, wound healing, tissue engineering, drug delivery, bone regeneration, and biosensors.


Asunto(s)
Celulosa , Ingeniería de Tejidos , Celulosa/metabolismo , Bacterias/metabolismo , Materiales Biocompatibles/metabolismo
5.
Clin Infect Dis ; 57(11): 1587-92, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23956169

RESUMEN

During 2009-2010, we examined 217 patients hospitalized with laboratory-confirmed pandemic influenza in 9 Influenza Hospitalization Surveillance Network sites and 413 age- and community-matched controls and found that a single dose of monovalent nonadjuvanted influenza A(H1N1)pdm09 vaccine was 50% (95% confidence interval, 13%-71%) effective in preventing hospitalization associated with A(H1N1)pdm09 virus infection.


Asunto(s)
Subtipo H1N1 del Virus de la Influenza A/inmunología , Vacunas contra la Influenza/administración & dosificación , Gripe Humana/prevención & control , Adolescente , Adulto , Anciano , Estudios de Casos y Controles , Niño , Preescolar , Femenino , Hospitalización/estadística & datos numéricos , Humanos , Lactante , Subtipo H1N1 del Virus de la Influenza A/genética , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Vacunas contra la Influenza/inmunología , Gripe Humana/diagnóstico , Gripe Humana/epidemiología , Gripe Humana/inmunología , Masculino , Persona de Mediana Edad , Pandemias , Reacción en Cadena de la Polimerasa , Vigilancia en Salud Pública , Estados Unidos/epidemiología , Adulto Joven
6.
Zookeys ; 1145: 131-167, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37234698

RESUMEN

A new species of Dipsas Laurenti, 1768, from Central Panama is described based on molecular analyses, hemipenial morphology, and external characters. This is the sixth species of Dipsas to be described for the country; the snake has been suspected to exist since 1977 and has not been thoroughly studied until now. Additionally, morphological comparations including scale counts are done with other species within the genus, and the current geographic distribution of Dipsastemporalis (Werner, 1909), the sister species, is updated. Finally, a key to the species of Dipsas currently known from Middle America is presented.


ResumenDescribimos una nueva especies de Dipsas Laurenti, 1768 de la región central de Panamá en base a análisis moleculares, morfología hemipenial y caracteres de morfología externa. Esta es la sexta especie del género Dipsas descrita para el país. Se sospechaba su existencia desde 1977 pero no había sido estudiada exhaustivamente hasta ahora. Adicionalmente, presentamos comparaciones morfológicas (incluyendo lepidosis) con otras especies del género y actualizamos la distribución geográfica de su especie hermana Dipsastemporalis (Werner, 1909). Finalmente, presentamos una clave para las especies de Dipsas distribuidas en Centroamérica.

7.
Methods Mol Biol ; 2546: 119-128, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36127583

RESUMEN

Monitoring urinary free cortisol (UFC) excretion helps assess adrenal function and is used to screen for endogenous Cushing's syndrome caused by an adrenal or pituitary tumor. While serum cortisol levels fluctuate in response to time of day, stress, and concentrations of cortisol-binding globulin (CBG), a 24-h urine collection measures the cortisol produced over the entire day and does not suffer from as much variability as a serum measurement.We describe here a method of measurement of urinary free cortisol (UFC) and cortisone using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Urine samples, combined with stable isotope-labeled internal standards, are extracted by liquid-liquid extraction using ethyl acetate and hexane. An API 5500 mass spectrometer operated in positive atmospheric pressure chemical ionization (APCI) mode is used for detection.


Asunto(s)
Cortisona , Globulinas , Cromatografía Liquida/métodos , Cortisona/orina , Hexanos , Hidrocortisona , Espectrometría de Masas en Tándem/métodos
8.
Clin Chim Acta ; 534: 173-175, 2022 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-35931175

RESUMEN

Cushing syndrome (CS) is caused by an excess of glucocorticoids that results in a variety of symptoms such as central obesity, moon facies, hirsutism, and reddish-purple stretch marks. Cortisol is the most potent endogenous glucocorticoid, and measuring the total amount excreted in the urine over a 24-hour period is useful to screen for CS caused by a tumor. However, most cases of CS are believed to be caused by exogenous glucocorticoids, such as prednisone and prednisolone, which are administered for anti-inflammatory and immunosuppressive treatments. This is often referred to as iatrogenic (drug-related or exogenous) CS. We modified an LC-MS/MS method for urine free cortisol to detect the presence of prednisone and prednisolone in patient samples. We wanted to understand the potential prevalence of exogenous CS in our patient population.


Asunto(s)
Síndrome de Cushing , Cromatografía Liquida/métodos , Síndrome de Cushing/inducido químicamente , Síndrome de Cushing/diagnóstico , Glucocorticoides , Humanos , Hidrocortisona , Enfermedad Iatrogénica , Prednisolona , Prednisona , Espectrometría de Masas en Tándem/métodos
9.
PLoS One ; 17(3): e0264930, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35245325

RESUMEN

Natural history collections are essential to a wide variety of studies in biology because they maintain large collections of specimens and associated data, including genetic material (e.g., tissues) for DNA sequence data, yet they are currently under-funded and collection staff have high workloads. With the advent of aggregate databases and advances in sequencing technologies, there is an increased demand on collection staff for access to tissue samples and associated data. Scientists are rapidly developing large DNA barcode libraries, DNA sequences of specific genes for species across the tree of life, in order to document and conserve biodiversity. In doing so, mistakes are made. For instance, inconsistent taxonomic information is commonly taken from different lending institutions and deposited in data repositories, such as the Barcode of Life Database (BOLD) and GenBank, despite explicit disclaimers regarding the need for taxonomic verification by the lending institutions. Such errors can have profound effects on subsequent research based on these mis-labelled sequences in data repositories. Here, we present the production of a large DNA barcode library of reptiles from the National Museum of Natural History tissue holdings. The library contains 2,758 sequences (2,205 COI and 553 16S) from 2260 specimens (four crocodilians, 37 turtles, and 2,219 lizards, including snakes), representing 583 named species, from 52 countries. In generating this library, we noticed several common mistakes made by scientists depositing DNA barcode data in public repositories (e.g., BOLD and GenBank). Our goal is to raise awareness of these concerns and offer advice to avoid such mistakes in the future to maintain accurate DNA barcode libraries to properly document Earth's biodiversity.


Asunto(s)
Código de Barras del ADN Taxonómico , Museos , Animales , Biodiversidad , ADN , Historia Natural , Reptiles/genética
10.
Science ; 367(6479): 814-816, 2020 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-32054766

RESUMEN

Biodiversity is declining at unprecedented rates worldwide. Yet cascading effects of biodiversity loss on other taxa are largely unknown because baseline data are often unavailable. We document the collapse of a Neotropical snake community after the invasive fungal pathogen Batrachochytrium dendrobatidis caused a chytridiomycosis epizootic leading to the catastrophic loss of amphibians, a food source for snakes. After mass mortality of amphibians, the snake community contained fewer species and was more homogeneous across the study site, with several species in poorer body condition, despite no other systematic changes in the environment. The demise of the snake community after amphibian loss demonstrates the repercussive and often unnoticed consequences of the biodiversity crisis and calls attention to the invisible declines of rare and data-deficient species.


Asunto(s)
Anfibios/microbiología , Biodiversidad , Quitridiomicetos/patogenicidad , Especies en Peligro de Extinción , Extinción Biológica , Serpientes , Animales
11.
Pract Lab Med ; 17: e00131, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31538105

RESUMEN

OBJECTIVES: Competitive immunoenyzmatic assays for estradiol (E2) and unconjugated estriol (uE3) on UniCel DxI 800 Access immunoassay systems (Beckman Coulter) utilize bovine alkaline phosphatase (ALP) for amplification. In these assays, rare 'IND' error flags indicate that a relative light unit (RLU) raw result is past the high or low end of the calibration curve but cannot be differentiated from an instrument error or analytical interference. The present studies were conducted to establish a protocol to identify analytical interference and to characterize its mechanism when present. DESIGN AND METHODS: Matrix and recovery studies were conducted to establish a protocol for interference identification. Spiking experiments with inactivated calf intestinal ALP were performed to determine whether interference could be blocked. Commercial anti-ALP antibodies (Abs) were spiked into human serum to model assay interference. Three E2 immunoassays which do not include ALP as a reagent component (cobas e602, Roche; Centaur XP, Siemens; ARCHITECT i2000SR, Abbott) were tested for comparative purposes. RESULTS: 1:2 dilution of specimen into Access Sample Diluent A (Beckman) differentiated IND error flags due to true low results (e.g. less than the analytical measurement range; AMR) from those due to assay interference. Interferences were reduced by pre-incubation with inactivated ALP and could be replicated by spiking with commercial anti-ALP Abs. CONCLUSIONS: Patient anti-bovine ALP Abs can cause interference on DxI 800 E2 and uE3 assays. This model can be used to investigate interference risk with other ALP-dependent assays.

12.
Science ; 359(6383): 1517-1519, 2018 03 30.
Artículo en Inglés | MEDLINE | ID: mdl-29599242

RESUMEN

Infectious diseases rarely end in extinction. Yet the mechanisms that explain how epidemics subside are difficult to pinpoint. We investigated host-pathogen interactions after the emergence of a lethal fungal pathogen in a tropical amphibian assemblage. Some amphibian host species are recovering, but the pathogen is still present and is as pathogenic today as it was almost a decade ago. In addition, some species have defenses that are more effective now than they were before the epidemic. These results suggest that host recoveries are not caused by pathogen attenuation and may be due to shifts in host responses. Our findings provide insights into the mechanisms underlying disease transitions, which are increasingly important to understand in an era of emerging infectious diseases and unprecedented global pandemics.


Asunto(s)
Enfermedades de los Animales/microbiología , Anuros/microbiología , Quitridiomicetos/patogenicidad , Enfermedades Transmisibles/epidemiología , Brotes de Enfermedades , Interacciones Huésped-Patógeno , Modelos Biológicos , Animales , Panamá
13.
Drug Test Anal ; 9(10): 1555-1560, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28182836

RESUMEN

Chronic use of opioid medications has been reported to cause altered sexual function. It is not known if non-opioid pain medications have similar effects. Assessment of this effect through the measurement of concentrations of free hormones is limited. Positivity of opioid medications (hydrocodone, oxycodone, morphine, methadone, tramadol and fentanyl) and non-opioid pain medications (gabapentin or pregabalin) in human serum and plasma samples from adult men and women were evaluated for association with concentrations of free testosterone (fTe) and free estradiol (fE2) measured using equilibrium dialysis-liquid chromatography-tandem mass spectrometry methods. Lower concentrations of fTe (p = 0.0253) were observed in samples positive for the hydrocodone, oxycodone and morphine group compared to age matched controls. The presence of methadone, tramadol, fentanyl and pregabalin had no effect on fTe. When compared with age-matched controls, women between 48-55 years of age showed reduced fE2 concentrations in samples positive for tramadol, fentanyl and gabapentin (p = 0.0243, 0.0045 and 0.0050, respectively). Particular opioid medications such as methadone, tramadol or fentanyl and non-opioid medications such as pregabalin or gabapentin may offer advantages over opioid medications for treating pain with fewer endocrinologic side effects. Measurement of free hormones in pain medication users could be important in determining their association with sexual function. Copyright © 2017 John Wiley & Sons, Ltd.


Asunto(s)
Analgésicos Opioides/farmacología , Analgésicos/farmacología , Estradiol/sangre , Dolor/tratamiento farmacológico , Testosterona/sangre , Adulto , Anciano , Anciano de 80 o más Años , Analgésicos/efectos adversos , Analgésicos/uso terapéutico , Analgésicos Opioides/efectos adversos , Analgésicos Opioides/uso terapéutico , Estradiol/metabolismo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dolor/sangre , Testosterona/metabolismo , Adulto Joven
14.
Methods Mol Biol ; 1378: 99-108, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26602122

RESUMEN

We describe a direct method of measurement of free estradiol using equilibrium dialysis followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Serum aliquots and internal standards are extracted by liquid-liquid extraction using methyl-tert-butyl ether (MTBE) followed by derivatization with dansyl chloride. An API 5500 mass spectrometer operated in positive electrospray mode is used for detection.


Asunto(s)
Análisis Químico de la Sangre/métodos , Cromatografía Liquida/métodos , Estradiol/sangre , Espectrometría de Masas en Tándem/métodos , Estradiol/química , Estradiol/aislamiento & purificación , Humanos , Extracción Líquido-Líquido , Éteres Metílicos/química
15.
Lancet Infect Dis ; 16(5): 556-564, 2016 05.
Artículo en Inglés | MEDLINE | ID: mdl-26856777

RESUMEN

BACKGROUND: Lyme borreliosis is the most common tick-borne disease in the northern hemisphere. It is a multisystem disease caused by Borrelia burgdorferi sensu lato genospecies and characterised by tissue localisation and low spirochaetaemia. In this study we aimed to describe a novel Borrelia species causing Lyme borreliosis in the USA. METHODS: At the Mayo clinic, from 2003 to 2014, we tested routine clinical diagnostic specimens from patients in the USA with PCR targeting the oppA1 gene of B burgdorferi sensu lato. We identified positive specimens with an atypical PCR result (melting temperature outside of the expected range) by sequencing, microscopy, or culture. We collected Ixodes scapularis ticks from regions of suspected patient tick exposure and tested them by oppA1 PCR. FINDINGS: 100 545 specimens were submitted by physicians for routine PCR from Jan 1, 2003 to Sept 30, 2014. From these samples, six clinical specimens (five blood, one synovial fluid) yielded an atypical oppA1 PCR product, but no atypical results were detected before 2012. Five of the six patients with atypical PCR results had presented with fever, four had diffuse or focal rash, three had symptoms suggestive of neurological inclusion, and two were admitted to hospital. The sixth patient presented with knee pain and swelling. Motile spirochaetes were seen in blood samples from one patient and cultured from blood samples from two patients. Among the five blood specimens, the median oppA1 copy number was 180 times higher than that in 13 specimens that tested positive for B burgdorferi sensu stricto during the same time period. Multigene sequencing identified the spirochaete as a novel B burgdorferi sensu lato genospecies. This same genospecies was detected in ticks collected at a probable patient exposure site. INTERPRETATION: We describe a new pathogenic Borrelia burgdorferi sensu lato genospecies (candidatus Borrelia mayonii) in the upper midwestern USA, which causes Lyme borreliosis with unusually high spirochaetaemia. Clinicians should be aware of this new B burgdorferi sensu lato genospecies, its distinct clinical features, and the usefulness of oppA1 PCR for diagnosis. FUNDING: US Centers for Disease Control and Prevention Epidemiology and Laboratory Capacity for Infectious Diseases (ELC) Cooperative Agreement and Mayo Clinic Small Grant programme.


Asunto(s)
Borrelia burgdorferi/clasificación , Borrelia burgdorferi/aislamiento & purificación , Enfermedad de Lyme/diagnóstico , Infecciones por Spirochaetales/sangre , Animales , Borrelia burgdorferi/genética , ADN Bacteriano/genética , Humanos , Enfermedad de Lyme/microbiología , Reacción en Cadena de la Polimerasa/métodos , Estados Unidos
17.
Clin Chim Acta ; 438: 330-6, 2015 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-25110813

RESUMEN

BACKGROUND: Challenges for steroid analysis by LC-MS/MS include low ionization efficiency, endogenous isobars with similar fragmentation patterns and chromatographic retention. Differential ion mobility spectrometry (DMS) provides an additional degree of separation prior to MS/MS detection, and shows promise in improving specificity of analysis. We developed a sensitive and specific method for measurement of corticosterone, 11-deoxycortisol, 11-deoxycorticosterone, 17-hydroxyprogesterone and progesterone in human serum and plasma using an ABSciex 5500 mass spectrometer equipped with a differential ion mobility interface. METHODS: 250µL aliquots of serum were spiked with deuterated internal standards and extracted with MTBE. The samples were analyzed using positive mode electrospray LC-DMS-MS/MS. The method was validated and compared with immunoassays and LC-MS/MS methods of reference laboratories. RESULTS: Inter and intra assay imprecision was <10%. Limits of quantification and detection in nmol/L were 0.18, 0.09 for corticosterone and 17-hydroxyprogesterone, 0.30, 0.16 for 11-deoxycortisol, 0.12, 0.06 for progesterone and 0.06, 0.03 for 11-deoxycorticosterone. Comparison for progesterone and 17-hydroxyprogesterone with immunoassay showed slopes of 0.97 and 1.0, intercepts of 0.16 and 0.10 and coefficients of determination (r(2)) of 0.92 and 0.97, respectively. Progesterone by immunoassay showed positive bias in samples measuring <3.18nmol/L. Reference intervals for progesterone and 11-deoxycorticosterone in post-menopausal women were found to be <2.88 and <0.28nmol/L respectively. CONCLUSIONS: We developed and validated an LC-DMS-MS/MS method for analysis of five endogenous steroids suitable for routine measurements in clinical diagnostic laboratories. Specificity gained with DMS allows reducing the complexity of sample preparation, decreasing LC run times and increasing speed of the analysis.


Asunto(s)
17-alfa-Hidroxiprogesterona/sangre , Corticosterona/sangre , Cortodoxona/sangre , Desoxicorticosterona/sangre , Progesterona/sangre , Análisis Espectral/normas , Cromatografía Liquida , Humanos , Estándares de Referencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Análisis Espectral/métodos , Espectrometría de Masas en Tándem
18.
Artículo en Inglés | MEDLINE | ID: mdl-25247493

RESUMEN

BACKGROUND: Accurate measurement of aldosterone is important for the standardized testing of primary hyperaldosteronism. Commercial immunoassays show substantial between-method variations resulting in significant clinical consequences. We developed a specific two dimensional (2D)-LC-MS/MS method for measuring aldosterone in human serum and plasma and compared it with three commercial immunoassays and an LC-MS/MS method. METHODS: 250 µL samples, controls and calibrators spiked with d4-aldosterone were subjected to liquid-liquid extraction. The samples were analyzed using negative mode electrospray and 2D-LC followed by MS detection using an ABSciex 5500 mass spectrometer and compared with immunoassays of Siemens (Coat-A-Count), DiaSorin (CLIA-LIAISON), and IBL (ELISA). Data was acquired using multiple reaction-monitoring mode. RESULTS: LOQ and LOD of the method were 0.04 and 0.02 nmol/L respectively. The assay was linear up to 166 nmol/L. Inter and intra-assay imprecision at 0.13, 1.38 and 8.30 nmol/L were <10%. Interferences were absent and no differences were observed between serum and plasma matrices. Method recovery ranged from 95% to 113%. Ion suppression was not observed. Evaluated immunoassays showed positive biases ranging between 22% and 37% when compared with the developed method. CONCLUSIONS: We developed and validated an accurate method for measurement of aldosterone in human serum and plasma using 2D-LC-MS/MS which is suitable for clinical purposes. The method is faster than previously published LC-MS/MS methods, uses less sample, has adequate sensitivity while being able to preserve high specificity in a cost effective manner. Linearity of the assay makes it promising for urine and adrenal venous samples. Comparison with three commercial immunoassays demonstrates the advantages of the developed method.


Asunto(s)
Aldosterona/sangre , Cromatografía Liquida/métodos , Inmunoensayo/métodos , Espectrometría de Masas en Tándem/métodos , Aldosterona/química , Humanos , Modelos Lineales , Extracción Líquido-Líquido , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
19.
Clin Chim Acta ; 413(11-12): 1008-14, 2012 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-22421268

RESUMEN

BACKGROUND: Measurement of free estradiol offers a better representation of the bioactive fraction of the hormone. We describe a direct equilibrium dialysis-liquid chromatography-tandem mass spectrometry (ED-LC-MS/MS) method for serum free estradiol. METHODS: Two hundred fifty microliter aliquots of serum were dialyzed for 22h followed by liquid-liquid extraction and derivatization with dansyl chloride. Free estradiol was measured using LC-MS/MS with an AB SCIEX 5500 mass spectrometer in positive ion and multiple reaction monitoring (MRM) mode. RESULTS: The limits of detection and quantification for free estradiol were 0.25 and 0.5pg/ml (0.9 and 1.8pmol/l) respectively. Total imprecision was less than 10%. Results of method comparison showed 3 times overestimation using indirect methods of measurement. Reference intervals in pre-menopausal women in follicular, mid-cycle, and luteal phases of cycle were <2.4, <3.1 and <2.6pg/ml (8.8, 11.4, 9.5pmol/l) respectively; in post menopausal women the concentrations were ≤0.5pg/ml (1.8pmol/l). CONCLUSIONS: ED-LC-MS/MS is a direct method for accurately measuring free estradiol, independent of total estradiol or sex hormone binding globulin concentrations. Imprecision and sensitivity of the method are adequate for clinical diagnostic applications. The degree of variation observed in the method comparison reinforces the relevance of method specific reference ranges.


Asunto(s)
Cromatografía Liquida/métodos , Estradiol/sangre , Ciclo Menstrual/sangre , Espectrometría de Masas en Tándem/métodos , Adulto , Diálisis/métodos , Femenino , Humanos , Posmenopausia/sangre , Premenopausia , Valores de Referencia , Globulina de Unión a Hormona Sexual/metabolismo
20.
Clin Chim Acta ; 412(13-14): 1221-8, 2011 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-21420944

RESUMEN

BACKGROUND: We developed a high sensitivity method for simultaneous measurement of cortisol, cortisone and dexamethasone. Using this method, we compared concentrations of cortisol, cortisone and their ratios in samples from intensive care unit (ICU) and non-ICU patients, and cortisol and dexamethasone concentrations in patients with Cushing's and suspected Cushing's syndrome. METHODS: Two hundred microliters of human serum aliquots were extracted using solid phase extraction and analyzed using liquid chromatography-tandem mass spectrometry. Primary mass transitions monitored for cortisol, cortisone and dexamethasone were m/z 363/121, 361/163 and 393/373 respectively. RESULTS: The limits of quantification for cortisol and cortisone were 0.3 µg/l (0.8 nmol/l) and for dexamethasone it was 0.5 µg/l (1.2 nmol/l). Total imprecision was <10.9%. Median cortisol to cortisone ratio of ICU patient samples was found to be 2 times higher than non-ICU samples. 54.2% of patients after 1mg dose of overnight dexamethasone could be categorized as consistent with Cushing's syndrome. CONCLUSIONS: The method has high sensitivity and specificity. High cortisol to cortisone ratios in samples from ICU patients suggest change in activity of 11ß-hydroxysteroid dehydrogenase in modulation of systemically available cortisol. Simultaneous measurement of dexamethasone and cortisol can be used to differentially diagnose diseases causing increased concentrations of cortisol.


Asunto(s)
Cromatografía Liquida/métodos , Cortisona/sangre , Dexametasona/sangre , Hidrocortisona/sangre , Enfermedades Renales/sangre , Enfermedades Renales/fisiopatología , Espectrometría de Masas en Tándem/métodos , Adolescente , Adulto , Anciano , Síndrome de Cushing/sangre , Síndrome de Cushing/fisiopatología , Femenino , Tasa de Filtración Glomerular , Humanos , Unidades de Cuidados Intensivos , Masculino , Persona de Mediana Edad , Adulto Joven
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