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1.
BMJ Mil Health ; 2022 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-35878971

RESUMEN

BACKGROUND: In the face of the COVID-19 pandemic, the Defence Science and Technology Laboratory (Dstl) and Defence Pathology combined to form the Defence Clinical Lab (DCL), an accredited (ISO/IEC 17025:2017) high-throughput SARS-CoV-2 PCR screening capability for military personnel. LABORATORY STRUCTURE AND RESOURCE: The DCL was modular in organisation, with laboratory modules and supporting functions combining to provide the accredited SARS-CoV-2 (envelope (E)-gene) PCR assay. The DCL was resourced by Dstl scientists and military clinicians and biomedical scientists. LABORATORY RESULTS: Over 12 months of operation, the DCL was open on 289 days and tested over 72 000 samples. Six hundred military SARS-CoV-2-positive results were reported with a median E-gene quantitation cycle (Cq) value of 30.44. The lowest Cq value for a positive result observed was 11.20. Only 64 samples (0.09%) were voided due to assay inhibition after processing started. CONCLUSIONS: Through a sustained effort and despite various operational issues, the collaboration between Dstl scientific expertise and Defence Pathology clinical expertise provided the UK military with an accredited high-throughput SARS-CoV-2 PCR test capability at the height of the COVID-19 pandemic. The DCL helped facilitate military training and operational deployments contributing to the maintenance of UK military capability. In offering a bespoke capability, including features such as testing samples in unit batches and oversight by military consultant microbiologists, the DCL provided additional benefits to the UK Ministry of Defence that were potentially not available from other SARS-CoV-2 PCR laboratories. The links between Dstl and Defence Pathology have also been strengthened, benefitting future research activities and operational responses.

2.
J Bone Miner Res ; 35(1): 81-91, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31499590

RESUMEN

Muscle mass is a commonly cited mediator of the relationship between physical activity (PA) and bone, representing the mechanical forces generated during PA. However, neuromuscular properties (eg, peak force) also account for unique portions of variance in skeletal outcomes. We used serial multiple mediation to explore the intermediary role of muscle mass and force in the relationships between cortical bone and moderate-to-vigorous intensity PA (MVPA). In a cross-sectional sample of young adults (n = 147, 19.7 ± 0.7 years old, 52.4% female) cortical diaphyseal bone was assessed via peripheral quantitative computed tomography at the mid-tibia. Peak isokinetic torque in knee extension was assessed via Biodex dynamometer. Thigh fat-free soft tissue (FFST) mass, assessed via dual-energy X-ray absorptiometry, represented the muscular aspect of tibial mechanical forces. Habitual MVPA was assessed objectively over 7 days using Actigraph GT3X+ accelerometers. Participants exceeded MVPA guidelines (89.14 ± 27.29 min/day), with males performing 44.5% more vigorous-intensity activity relative to females (p < 0.05). Males had greater knee extension torque and thigh FFST mass compared to females (55.3%, and 34.2%, respectively, all p < 0.05). In combined-sex models, controlling for tibia length and age, MVPA was associated with strength strain index (pSSI) through two indirect pathways: (i) thigh FFST mass (b = 1.11 ± 0.37; 95% CI, 0.47 to 1.93), and (i) thigh FFST mass and knee extensor torque in sequence (b = 0.30 ± 0.16; 95% CI, 0.09 to 0.73). However, in sex-specific models MVPA was associated with pSSI indirectly through its relationship with knee extensor torque in males (b = 0.78 ± 0.48; 95% CI, 0.04 to 2.02) and thigh FFST mass in females (b = 1.12 ± 0.50; 95% CI, 0.37 to 2.46). Bootstrapped CIs confirmed these mediation pathways. The relationship between MVPA and cortical structure appears to be mediated by muscle in young adults, with potential sex-differences in the muscular pathway. If confirmed, these findings may highlight novel avenues for the promotion of bone strength in young adults. © 2019 American Society for Bone and Mineral Research.


Asunto(s)
Densidad Ósea , Hueso Cortical , Absorciometría de Fotón , Hueso Cortical/diagnóstico por imagen , Estudios Transversales , Ejercicio Físico , Femenino , Humanos , Masculino , Adulto Joven
3.
Clin Nutr ; 39(8): 2609-2616, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-31839431

RESUMEN

BACKGROUND & AIMS: Overall diet quality is a key predictor of disease risk and mortality. Diets higher in animal protein have been associated with increased disease risk and all-cause mortality. However, the source of protein consumed will inevitably influence the intake of other macronutrients and micronutrients which can also play a role in the onset of disease. The aim of the present study was to assess the relationship between animal and plant protein intake and overall diet quality in young adult females and males. METHODS: Dietary intake was assessed via 3-day food log (n = 150; 53% females) and data were analyzed using the Nutrition Data Systems for Research (NDSR). RESULTS: Females and males consuming <70% of their protein from animal sources had higher scores on a modified Healthy Eating Index (HEI) compared those consuming >70% of their protein from animal sources. Males scored lower than females on the modified HEI regardless of protein source intake variation. CONCLUSIONS: Our findings suggest that overall diet quality differs with varying protein source consumption and eating <70% of protein from animal sources might lead to a better score on the HEI. Future research investigating protein source and disease risk should examine overall dietary quality as a potential effect modifier.


Asunto(s)
Proteínas Dietéticas Animales/análisis , Dieta Saludable/estadística & datos numéricos , Proteínas de Plantas/análisis , Índice de Masa Corporal , Encuestas sobre Dietas , Ingestión de Alimentos , Conducta Alimentaria , Femenino , Humanos , Masculino , Micronutrientes/análisis , Nutrientes/análisis , Adulto Joven
4.
Arthritis Rheumatol ; 71(9): 1426-1436, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-30883031

RESUMEN

OBJECTIVE: Rheumatoid arthritis (RA) patients with the lowest circulating low-density lipoprotein (LDL) concentrations are at heightened risk of cardiovascular events. However, the atherosclerosis burden within this subgroup is unknown. METHODS: RA patients pooled from 4 cohort studies of cardiovascular disease (CVD; n = 546) were compared with non-RA controls from the Multi-Ethnic Study of Atherosclerosis (n = 5,279). Those taking lipid-lowering medications were excluded. Differences in cardiac computed tomography-derived Agatston coronary artery calcium (CAC) scores between the RA and control groups were compared across strata of LDL concentration. RESULTS: Among those with low LDL concentrations (<70 mg/dl), mean adjusted CAC scores were >4-fold higher for RA patients than for controls (18.6 versus 4.6 Agatston units, respectively; P < 0.001), a difference significantly greater than that in any other LDL concentration stratum except LDL concentration ≥160 mg/dl. Similarly, 32% of the RA patients with low LDL concentration had a CAC score of ≥100 Agatston units compared with only 7% of controls in the same LDL concentration stratum (odds ratio 5.97; P < 0.001), a difference significantly greater than that in all of the other LDL concentration strata. Low LDL concentration was most strongly associated with higher CAC score among RA patients who were white, had ever smoked, or were not obese. Other than a higher frequency of current smokers, RA patients with low LDL concentrations did not have more CVD risk factors or higher measures of RA disease activity or severity than RA patients with higher LDL concentrations. CONCLUSION: RA patients with low LDL concentration may represent a group for whom heightened screening and prevention of atherosclerotic CVD is appropriate.


Asunto(s)
Artritis Reumatoide/complicaciones , Aterosclerosis/etiología , Enfermedad de la Arteria Coronaria/etiología , Lipoproteínas LDL/sangre , Anciano , Artritis Reumatoide/sangre , Artritis Reumatoide/patología , Aterosclerosis/sangre , Calcinosis/sangre , Calcinosis/etiología , Calcio/análisis , Enfermedades Cardiovasculares/sangre , Enfermedades Cardiovasculares/etiología , Estudios de Casos y Controles , Enfermedad de la Arteria Coronaria/sangre , Vasos Coronarios/patología , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Factores de Riesgo
5.
Med Sci Sports Exerc ; 50(7): 1433-1441, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29462101

RESUMEN

PURPOSE: Muscle cross-sectional area (MCSA) is often used as a surrogate for the forces applied to bones during physical activity. Although MCSA is a strong predictor of cortical bone status, its use makes assumptions about the relationship between muscle size and force that are inaccurate. Furthermore, to measure MCSA and other muscle force surrogates typically requires expensive and/or radiative laboratory equipment. Thus, this study aimed to determine whether clinical laboratory- and field-based methodologies for measuring muscular force capacity accounted for similar variance in diaphyseal cortical bone status as a commonly used muscular force surrogate, MCSA, at the midtibia in young men and women. METHODS: Healthy young adults (n = 142, 19.7 ± 0.7 yr old, 52.8% female) were assessed via peripheral quantitative computed tomography at the midtibia for cortical bone status and MCSA. Muscle force capacity was measured via Biodex dynamometer, Nottingham leg extensor power rig, and Vertec vertical jump. Regression analysis compared the independent variance predicted by each muscle force measure with that of MCSA, accounting for relevant confounders. RESULTS: MCSA, knee extension peak torque, and peak anaerobic power from vertical jump were independent predictors of select cortical structural outcomes (cortical thickness and area, periosteal and endosteal circumference, and estimated strength) accounting for up to 78.4% of the variance explained (all P < 0.05). However, cortical volumetric bone mineral density was unrelated to any measure or surrogate of muscle force capacity. CONCLUSIONS: MCSA is a strong independent predictor of cortical bone structure; however, both laboratory- and field-based measures of peak torque and/or peak anaerobic power are promising alternatives, explaining similar and sometimes greater variance than MCSA.


Asunto(s)
Densidad Ósea , Hueso Cortical/anatomía & histología , Hueso Cortical/diagnóstico por imagen , Fuerza Muscular , Músculo Esquelético/fisiología , Femenino , Humanos , Masculino , Análisis de Regresión , Tibia/anatomía & histología , Tibia/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Torque , Adulto Joven
6.
J Am Heart Assoc ; 5(1)2016 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-26727968

RESUMEN

BACKGROUND: Cardiovascular disease (CVD) is the leading cause of death in rheumatoid arthritis (RA) patients. This study is the first to report the association of hydroxychloroquine (an antirheumatic medication that has been associated with decreased risk of diabetes, a less atherogenic lipid profile, and antithrombotic properties) with CVD in RA. METHODS AND RESULTS: A retrospective incident RA cohort from January 1, 2001, to October 31, 2013, excluding patients with CVD prior to RA diagnosis, was constructed. Patients were categorized as hydroxychloroquine users versus nonusers and were allowed to contribute time to either group according to hydroxychloroquine exposure. The primary outcome was adjudicated incident CVD defined as a composite of coronary artery disease, stroke, transient ischemic attack, sudden cardiac death, and peripheral artery disease with arterial revascularization procedure. The secondary outcome was a composite of incident coronary artery disease, stroke, and transient ischemic attack. Cox time-varying regression models were used to estimate the association between hydroxychloroquine exposure and development of CVD, after adjusting for propensity score and relevant confounders, including demographics, CVD-related comorbidities, RA severity, and activity indicators and medications. We included 1266 RA patients, 547 hydroxychloroquine users, and 719 nonusers. During the observation period, 102 CVD events occurred, 3 in hydroxychloroquine users and 99 in nonusers. The fully adjusted Cox model showed a hazard ratio of 0.28 (95% CI 0.12-0.63, P=0.002) for incident CVD and 0.30 (95% CI 0.13-0.68, P=0.004) for incident composite coronary artery disease, stroke, and transient ischemic attack for hydroxychloroquine users versus nonusers, respectively. CONCLUSION: In this hypothesis-generating study, hydroxychloroquine use was associated with a 72% decrease in the risk of incident CVD in RA patients. If these preliminary results are confirmed in larger studies, our findings may be used as a rationale for a randomized study of hydroxychloroquine use for primary prevention of CVD in RA or nonrheumatic high-risk patients.


Asunto(s)
Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Enfermedades Cardiovasculares/prevención & control , Hidroxicloroquina/uso terapéutico , Adulto , Anciano , Artritis Reumatoide/diagnóstico , Artritis Reumatoide/epidemiología , Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/epidemiología , Comorbilidad , Femenino , Humanos , Incidencia , Estimación de Kaplan-Meier , Modelos Logísticos , Masculino , Persona de Mediana Edad , Pennsylvania/epidemiología , Puntaje de Propensión , Modelos de Riesgos Proporcionales , Factores Protectores , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento
8.
Diabetologia ; 58(10): 2336-43, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26197707

RESUMEN

AIMS/HYPOTHESIS: Hydroxychloroquine (HCQ), an antimalarial drug with anti-inflammatory properties, is employed in rheumatic diseases. In observational studies, patients with rheumatic diseases treated with HCQ have a lower risk of developing diabetes. However, the physiological mechanisms remain unexplained. We hypothesised that HCQ may have favourable effects on insulin sensitivity and/or beta cell function. METHODS: This was a randomised, double-blind, parallel-arm (placebo vs HCQ 400 mg/day) trial at the University of Pittsburgh. Randomisation was conducted by a computer system with concealment by sealed envelopes. Treatment duration was 13 ± 1 weeks. Randomised participants (HCQ n = 17; placebo n = 15) were non-diabetic volunteers, age >18, overweight or obese, with one or more markers of insulin resistance. All participants were included in intention-to-treat analysis. Outcomes were changes in insulin sensitivity and beta cell function measured by intravenous glucose tolerance tests and minimal model analysis. RESULTS: There was a positive change in insulin sensitivity with HCQ but not placebo (mean ± SEM: +20.0% ± 7.1% vs -18.4% ± 7.9%, respectively; p < 0.01; difference: 38.3% ± 10.6%; 95% CI: 17%, 60%). Improvement in beta cell function was also observed with HCQ but not placebo (+45.4% ± 12.3% vs -19.7% ± 13.6%; p < 0.01; difference: 65% ± 19%; 95% CI: 27%, 103%). There were modest treatment effects on fasting plasma glucose and HbA(1c) (p < 0.05) but circulating markers of inflammation (IL-6, IL-1, TNF-α, soluble intercellular adhesion molecule) were not affected in either group. In contrast, adiponectin levels increased after HCQ treatment but not after placebo (+18.7% vs +0.7%, respectively; p < 0.001). Both low- and high-molecular-weight adiponectin forms accounted for the increase. There were no serious or unexpected adverse effects. CONCLUSIONS/INTERPRETATION: HCQ improves both beta cell function and insulin sensitivity in non-diabetic individuals. These metabolic effects may explain why HCQ treatment is associated with a lower risk of type 2 diabetes. An additional novel observation is that HCQ improves adiponectin levels, possibly being a mediator of the favourable effects on glucose metabolism. Our findings suggest that HCQ is a drug with considerable metabolic effects that warrant further exploration in disorders of glucose metabolism. TRIAL REGISTRATION: Clinicaltrials.gov NCT01326533 FUNDING: This study was funded by National Institutes of Health no. 5R21DK082878, UL1-RR024153 and UL-1TR000005.


Asunto(s)
Hidroxicloroquina/farmacología , Resistencia a la Insulina/fisiología , Células Secretoras de Insulina/efectos de los fármacos , Sobrepeso/metabolismo , Adulto , Glucemia/metabolismo , Citocinas/sangre , Método Doble Ciego , Femenino , Humanos , Insulina/sangre , Células Secretoras de Insulina/metabolismo , Molécula 1 de Adhesión Intercelular/sangre , Masculino , Persona de Mediana Edad , Obesidad/sangre , Obesidad/metabolismo , Sobrepeso/sangre , Resultado del Tratamiento
9.
Heredity (Edinb) ; 114(3): 309-17, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25370212

RESUMEN

Cytological studies have shown many newly formed allopolyploids (neoallopolyploids) exhibit chromosomal variation as a result of meiotic irregularities, but few naturally occurring neoallopolyploids have been examined. Little is known about how long chromosomal variation may persist and how it might influence the establishment and evolution of allopolyploids in nature. In this study we assess chromosomal composition in a natural neoallotetraploid, Tragopogon mirus, and compare it with T. miscellus, which is an allotetraploid of similar age (~40 generations old). We also assess whether parental gene losses in T. mirus correlate with entire or partial chromosome losses. Of 37 T. mirus individuals that were karyotyped, 23 (62%) were chromosomally additive of the parents, whereas the remaining 14 individuals (38%) had aneuploid compositions. The proportion of additive versus aneuploid individuals differed from that found previously in T. miscellus, in which aneuploidy was more common (69%; Fisher's exact test, P=0.0033). Deviations from parental chromosome additivity within T. mirus individuals also did not reach the levels observed in T. miscellus, but similar compensated changes were observed. The loss of T. dubius-derived genes in two T. mirus individuals did not correlate with any chromosomal changes, indicating a role for smaller-scale genetic alterations. Overall, these data for T. mirus provide a second example of prolonged chromosomal instability in natural neoallopolyploid populations.


Asunto(s)
Cromosomas de las Plantas/genética , Genética de Población , Poliploidía , Tragopogon/genética , ADN de Plantas/genética , Evolución Molecular , Reordenamiento Génico , Genoma de Planta , Cariotipo
10.
Rheumatol Int ; 35(6): 1059-67, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25540049

RESUMEN

The aim of this article was to examine the association of glucocorticoid use and dose and changes in the lipid profile in rheumatoid arthritis (RA) patients. RA patients between January 1, 2001, and November 30, 2011, who received oral or intravenous glucocorticoids and who had lipid levels within 1 year before and 1 year after ongoing (at least 3 months) glucocorticoids use along with RA patients who did not take glucocorticoids (controls) were included. Glucocorticoid exposure was calculated as a weighted daily dose in prednisone equivalents and analyzed using as cutoff dose prednisone equivalent of 7.5 mg/day. Outcomes were changes in high-density lipoprotein (HDL), low-density lipoprotein (LDL), total cholesterol (TC), triglycerides, and TC/HDL ratio and were calculated in linear regression models adjusting for relevant confounders. In total, 202 subjects on glucocorticoids and 436 controls were included. The glucocorticoid group of ≥7.5 mg/day had the greatest increase in HDL of 6.0 mg/dL (p = 0.003 compared to controls) with lower increases of 3.1 and 2.4 mg/dL in the glucocorticoid group of <7.5 mg/day and controls, respectively. There were no significant differences in other parameters of the lipid profile between the two glucocorticoid groups and controls. In this RA cohort, glucocorticoid dose equivalent of prednisone ≥7.5 mg/day was associated with increased HDL and no change in LDL or TC/HDL ratio compared to no glucocorticoid use These results suggest that this glucocorticoid dose is not associated with an atherogenic lipid profile in RA, a finding that is important in this patient population at high risk for cardiovascular disease.


Asunto(s)
Antirreumáticos/administración & dosificación , Artritis Reumatoide/tratamiento farmacológico , Glucocorticoides/administración & dosificación , Lipoproteínas HDL/sangre , Prednisona/administración & dosificación , Antirreumáticos/efectos adversos , Artritis Reumatoide/sangre , Artritis Reumatoide/diagnóstico , Biomarcadores/sangre , Esquema de Medicación , Registros Electrónicos de Salud , Glucocorticoides/efectos adversos , Humanos , Prednisona/efectos adversos , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento , Regulación hacia Arriba
11.
Arthritis Care Res (Hoboken) ; 66(3): 355-63, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24023053

RESUMEN

OBJECTIVE: To determine the association of tumor necrosis factor α (TNFα) inhibitors with risk for cardiovascular disease (CVD) in rheumatoid arthritis (RA) patients. METHODS: A retrospective cohort of 2,101 incident RA patients was established. Medication exposure was categorized into the following groups: TNFα inhibitors alone or in combination with methotrexate (MTX; aTNF group); MTX alone or in combination with other nonbiologic disease-modifying antirheumatic drugs (DMARDs; MTX group); and no MTX, nonbiologic DMARDs (reference group). Primary outcome was adjudicated incident coronary artery disease (CAD), defined as myocardial infarction, unstable angina, or coronary revascularization procedure. Secondary outcome was adjudicated incident CVD, defined as a composite of CAD, stroke, transient ischemic attack, abdominal aortic aneurysm, peripheral arterial disease, or arterial revascularization procedure. Cox regression models were used to calculate the hazard ratio for CAD and CVD for the aTNF and MTX groups compared to the reference group. RESULTS: There were 46 incident CAD and 82 incident CVD events. Adjusting for covariates associated with CAD and CVD, the hazard ratio for incident CAD was 0.45 (95% confidence interval [95% CI] 0.21-0.96) for the aTNF group and 0.54 (95% CI 0.27-1.09) for the MTX group compared to the reference group. Use of TNFα inhibitors for >16.1 months was associated with a relative risk for CAD of 0.18 (95% CI 0.06-0.50) and for CVD of 0.31 (95% CI 0.15-0.65) compared to the reference group. A similar, although not significant, trend was seen with the MTX group. CONCLUSION: Use of TNFα inhibitors is associated with a decreased risk for CAD in RA; the risk decreases further with long-term use. This should be considered when weighing the risks versus benefits of these medications.


Asunto(s)
Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Enfermedad de la Arteria Coronaria/prevención & control , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Adulto , Anciano , Antirreumáticos/farmacología , Artritis Reumatoide/complicaciones , Femenino , Humanos , Masculino , Metotrexato/uso terapéutico , Persona de Mediana Edad , Estudios Retrospectivos
12.
Arthritis Rheum ; 65(2): 334-42, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23044791

RESUMEN

OBJECTIVE: While medications used to treat rheumatoid arthritis (RA) may affect survival in RA, few studies take into account the propensity for medication use, which may reflect selection bias in treatment allocation in survival models. We undertook this study to examine the relationship between methotrexate (MTX) use and mortality in RA, after controlling for individual propensity scores for MTX use. METHODS: We studied 5,626 RA patients prospectively for 25 years to determine the risk of death associated with MTX use, modeled in time-varying Cox regression models. We used the random forest method to generate individual propensity scores for MTX use at study entry and during followup in a time-varying manner; these scores were included in the multivariate model. We also investigated whether selective discontinuation of MTX immediately prior to death altered the risk of mortality, and we examined the association of duration of MTX use with survival. RESULTS: During followup, 666 patients (12%) died. MTX use was associated with reduced risk of death (adjusted hazard ratio 0.30 [95% confidence interval 0.09-1.03]). Selective MTX cessation immediately before death did not account for the protective association of MTX use with mortality. Only MTX use for >1 year was associated with lower risks of mortality, but associations were not stronger with longer durations of use. CONCLUSION: MTX use was associated with a 70% reduction in mortality in RA.


Asunto(s)
Antirreumáticos/uso terapéutico , Artritis Reumatoide/mortalidad , Metotrexato/uso terapéutico , Adulto , Anciano , Artritis Reumatoide/tratamiento farmacológico , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Encuestas y Cuestionarios , Factores de Tiempo , Resultado del Tratamiento
13.
Int J Dev Neurosci ; 30(7): 570-7, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22982053

RESUMEN

The plasticity and vulnerability of the rat spinal cord (SC) during postnatal development has been less investigated compared to other CNS structures. In this study, we determined the effects of thyroid hormonal (TH) deficiency and excess on postnatal growth and neurochemical development of the rat SC. The growth as well as the specific and total activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) enzymes of the SC were determined in hypo- and hyperthyroid rat pups at postnatal (P) days P1, P5, P10 and P21 (weaning), and were compared to age-matched untreated normal controls. AChE is a cholinergic synaptic enzyme while BuChE is a metabolic enzyme mainly found in glial cells and neurovascular cells. The SC is rich in somatic motor, autonomic cholinergic neurons and associated interneurons. Daily subcutaneous injection of pups with thyroxine (T4) and administration of antithyroid goitrogen propylthiouracil (PTU) in the litter's drinking water were used to induce hyper- and hypothyroidism, respectively. Enzyme assays were carried out spectrophotometrically at the above-mentioned ages, using SC homogenates with acetylthiocholine-chloride as the substrate, together with specific cholinesterase inhibitors, which specifically target AChE and BuChE. SC weights were significantly lower at P10 and P21 in hypothyroid pups but unchanged in the hyperthyroid ones. Hypothyroidism significantly reduced both specific and total AChE activity in SC of P10 and P21 rat pups, while having no effects on the BuChE activity, although total BuChE activity was decreased due to reduced total tissue weight. In contrast both specific and total AChE activities were markedly and significantly increased (>100%) in the P10 and P21 hyperthyroid pups. However, BuChE specific activity was unaffected by this treatment. The results indicate that hypothyroid condition significantly reduces, while hyperthyroidism increases, the postnatal development of cholinergic synapses, thereby influencing the functional development of this major sensory and motor structure. However, the neurochemical development of glia and other non-neuronal cells, where BuChE is mainly localized, is comparatively unaffected in these abnormal developmental conditions.


Asunto(s)
Acetilcolinesterasa/fisiología , Butirilcolinesterasa/fisiología , Hipertiroidismo/enzimología , Hipotiroidismo/enzimología , Médula Espinal/enzimología , Médula Espinal/crecimiento & desarrollo , Animales , Animales Recién Nacidos , Antitiroideos , Peso Corporal/efectos de los fármacos , Peso Corporal/fisiología , Femenino , Hipertiroidismo/inducido químicamente , Hipertiroidismo/patología , Hipotiroidismo/inducido químicamente , Hipotiroidismo/patología , Embarazo , Propiltiouracilo , Ratas , Ratas Sprague-Dawley , Tiroxina
14.
Int J Dev Neurosci ; 30(7): 578-83, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22922167

RESUMEN

The effects of growth hormone (GH) deficiency on the developmental changes in the abundance and activity of cholinesterase enzymes were studied in the developing spinal cord (SC) of postnatal rats by measuring the specific activity of acetylcholinesterase (AChE), a marker for cholinergic neurons and their synaptic compartments, and butyrylcholinesterase (BuChE), a marker for glial cells and neurovascular cells. Specific activities of these two enzymes were measured in SC tissue of 21- and 90 day-old (P21, weaning age; P90, young adulthood) GH deficient spontaneous dwarf (SpDwf) mutant rats which lack anterior pituitary and circulating plasma GH, and were compared with SC tissue of normal age-matched control animals. Assays were carried out for AChE and BuChE activity in the presence of their specific chemical inhibitors, BW284C51 and iso-OMPA, respectively. Results revealed that mean AChE activity was markedly and significantly reduced [28% at P21, 49% at P90, (p<0.01)] in the SC of GH deficient rats compared to age-matched controls. GH deficiency had a higher and more significant effect on AChE activity of the older (P90) rats than the younger ones (P21) ones. In contrast, BuChE activity in SC showed no significant changes in GH deficient rats at either of the two ages studied. Results imply that, in the absence of pituitary GH, the postnatal proliferation of cholinergic synapses in the rat SC, a CNS structure, where AChE activity is abundant, is markedly reduced during both the pre- and postweaning periods; more so in the postweaning than preweaning ages. In contrast, the absence of any effects on BuChE activity implies that GH does not affect the development of non-neuronal elements, e.g., glia, as much as the neuronal and synaptic compartments of the developing rat SC.


Asunto(s)
Acetilcolinesterasa/metabolismo , Butirilcolinesterasa/metabolismo , Hormona del Crecimiento/deficiencia , Médula Espinal/enzimología , Médula Espinal/crecimiento & desarrollo , Envejecimiento/fisiología , Animales , Enanismo/genética , Femenino , Hormona del Crecimiento/genética , Indicadores y Reactivos , Masculino , Embarazo , Ratas , Ratas Sprague-Dawley , Hormonas Tiroideas/farmacología
15.
Bioorg Med Chem Lett ; 22(9): 3287-90, 2012 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-22480433

RESUMEN

Described is the synthesis of two biotinylated derivatives of a cytotoxic macrocycle. Pull-down assays indicate that this macrocycle targets the N-middle domain of Hsp90. Untagged compound can effectively compete away tagged compound-Hsp90 protein complexes, confirming the binding specificity of the macrocycle for Hsp90. The macrocycle is similar in potency to other structurally-related analogs of Sansalvamide A (San A) and induces apoptosis via a caspase 3 mechanism. Unlike other San A derivatives, we show that the macrocycle does not inhibit binding between C-terminal client proteins and co-chaperones and Hsp90, suggesting that it has a unique mechanism of action.


Asunto(s)
Proteínas HSP90 de Choque Térmico/efectos de los fármacos , Compuestos Macrocíclicos/farmacología , Animales , Apoptosis/efectos de los fármacos , Biotinilación , Caspasa 3 , Depsipéptidos/farmacología , Descubrimiento de Drogas , Humanos , Compuestos Macrocíclicos/síntesis química , Unión Proteica
16.
Vox Sang ; 102(1): 55-64, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21592135

RESUMEN

BACKGROUND AND OBJECTIVES: Weak expression of A/B histo-blood group antigens is often explained by single nucleotide substitutions at the ABO locus. However, hybrid alleles containing segments from different ABO alleles can result in unexpected phenotypes and may complicate genotype analysis. We investigated the basis of weak B phenotype in a referred sample. MATERIALS AND METHODS: A healthy young woman was serologically phenotyped as AB(weak) and RBCs were characterized by flow cytometry. All seven ABO exons, five introns plus the 5'-region including the CCAAT-binding factor/Nuclear Factor Y (CBF/NF-Y) binding enhancer were sequenced. ABO transcript levels were measured in fresh peripheral blood samples. Expression of B antigen was semiquantified following transfection of HeLa cells. RESULTS: A new B(weak) allele with 53G>T resulted in a characteristic pattern of moderately weakened B antigen expression on RBCs. Its sequence revealed a novel hybrid between O(2) [O03] and B [B101] alleles with a crossingover region in intron 4 as defined by allele-specific polymorphisms. B transcript levels were similar to normal controls despite the O(2) -related single CBF/NF-Y-binding 43-bp motif in the enhancer region. Expression of the glycosyltransferase including the O(2) -specific Arg18Leu substitution resulted in a slight decrease in B-antigen-positive cells. CONCLUSION: We describe here the first hybrid between an O(2) and a B allele and characterized the associated decrease in B antigen expression. Although it lacks three enhancer repeat units compared to common B alleles, the resulting transcript level was unaltered. This study challenges previous suggestions that the number of 43-bp motifs in the ABO enhancer determines transcription rates in erythroid cells.


Asunto(s)
Sistema del Grupo Sanguíneo ABO/genética , Elementos de Facilitación Genéticos/genética , Hematología/métodos , Alelos , Anticuerpos/inmunología , Antígenos/inmunología , Eritrocitos/inmunología , Células Eritroides/citología , Exones , Genotipo , Células HeLa , Humanos , Sistema Inmunológico , Intrones , Fenotipo , Análisis de Secuencia de ADN , Transcripción Genética
17.
Arthritis Care Res (Hoboken) ; 64(2): 215-21, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21972198

RESUMEN

OBJECTIVE: To examine the association of tumor necrosis factor α (TNFα) inhibitor use and the risk of developing diabetes mellitus in a rheumatoid arthritis (RA) inception cohort. METHODS: Adults diagnosed with RA between January 1, 2001, and December 31, 2009, were identified (n = 1,881). Prevalent cases of diabetes mellitus (n = 294) were excluded. Information on sociodemographic data, medical history, body mass index (BMI), laboratory measures, and medications was collected from the electronic health record. Incident diabetes mellitus was defined using the 2010 American Diabetes Association criteria or physician-established diagnosis. Time-varying Cox proportional hazards regression models were used to adjust for age, sex, race, BMI, rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibodies (anti-CCP), erythrocyte sedimentation rate (ESR), and use of nonsteroidal antiinflammatory drugs (NSAIDs), glucocorticoids, hydroxychloroquine, and methotrexate. RESULTS: A total of 1,587 incident RA patients without diabetes mellitus were included. The anti-TNFα users (n = 522) had a lower median age but greater baseline BMI; maximum ESR, RF, and anti-CCP positivity; and NSAID, glucocorticoid, or methotrexate use. The median followup time for the ever and never TNFα inhibitor users was 44.9 months (interquartile range [IQR] 23.7-73.0 months) and 37.1 months (IQR 16.3-65.1 months), respectively (P < 0.001). Of the 91 patients developing diabetes mellitus, 16 were ever and 75 were never TNFα inhibitor users, yielding incidence rates of 8.6 and 17.2 per 1,000 person-years (P = 0.048), respectively. Adjusting for covariates, the hazard ratio for incident diabetes mellitus in TNFα inhibitor users was 0.49 (95% confidence interval 0.24-0.99, P = 0.049) compared to the never users. CONCLUSION: In this inception RA cohort, anti-TNFα use was associated with a 51% reduction in risk of developing diabetes mellitus.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Antirreumáticos/uso terapéutico , Artritis Reumatoide , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Anciano , Artritis Reumatoide/diagnóstico , Artritis Reumatoide/tratamiento farmacológico , Artritis Reumatoide/epidemiología , Comorbilidad , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/epidemiología , Diabetes Mellitus/prevención & control , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pennsylvania/epidemiología , Modelos de Riesgos Proporcionales , Factores de Riesgo
18.
Nature ; 476(7361): 421-4, 2011 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-21866154

RESUMEN

Supermassive black holes have powerful gravitational fields with strong gradients that can destroy stars that get too close, producing a bright flare in ultraviolet and X-ray spectral regions from stellar debris that forms an accretion disk around the black hole. The aftermath of this process may have been seen several times over the past two decades in the form of sparsely sampled, slowly fading emission from distant galaxies, but the onset of the stellar disruption event has not hitherto been observed. Here we report observations of a bright X-ray flare from the extragalactic transient Swift J164449.3+573451. This source increased in brightness in the X-ray band by a factor of at least 10,000 since 1990 and by a factor of at least 100 since early 2010. We conclude that we have captured the onset of relativistic jet activity from a supermassive black hole. A companion paper comes to similar conclusions on the basis of radio observations. This event is probably due to the tidal disruption of a star falling into a supermassive black hole, but the detailed behaviour differs from current theoretical models of such events.

19.
Phys Ther ; 91(9): 1367-76, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21719635

RESUMEN

BACKGROUND: Individuals with rheumatoid arthritis (RA) often are sedentary and have an increased risk of developing comorbid conditions. Women with RA are more likely to experience challenges in maintaining an active lifestyle over their life span than men with RA or people who are healthy. As the benefits of physical activity (PA) are well known, measuring PA accurately in this population is important. OBJECTIVES: The purposes of this study were: (1) to characterize PA as measured with the SenseWear Armband (SWA) in women with RA and (2) to determine the measurement time frame to obtain consistent estimates of PA and daily energy expenditure (EE) in women with RA. DESIGN: This was a cross-sectional study. METHODS: Participants wore the SWA for 7 days. Measurements of daily total energy expenditure (TEE), physical activity energy expenditure (PAEE) during activities at or above 1 metabolic equivalent (MET) level (PAEE≥1MET), PAEE during activities at or above 2 METs (PAEE≥2METs), PAEE during activities at or above 3 METs (PAEE≥3METs), and number of steps were obtained. RESULTS: Fifty-three women participated. Complete data were obtained for 47 participants (89%). Daily usage of the SWA was 98% of the time (23:31 hours/24 hours). Means (SD) were 2,099 (340) kcal/d for TEE, 1,050 (331) kcal/d for PAEE≥1MET, 642 (309) kcal/d for PAEE≥2METs, 239 (178) kcal/d for PAEE≥3METs, and 7,260 (2,710) for number of steps. Results of intraclass correlation coefficient analyses and multiple linear regressions indicated that 2 days were needed to reliably estimate TEE; 3 days for PAEE≥1MET, PAEE≥2METs, and number of steps; and 4 days for PAEE≥3METs. LIMITATIONS: The sample was composed of well-educated women with RA who had mild to moderate difficulty performing daily activities. CONCLUSION: The SWA may be useful to quantify PA in women with RA and to monitor effectiveness of interventions aiming to increase PA levels. Minimizing the number of days necessary for data collection will reduce the individual's burden and may improve adherence in studies of PA behaviors.


Asunto(s)
Artritis Reumatoide/fisiopatología , Monitoreo Ambulatorio/instrumentación , Actividad Motora/fisiología , Actividades Cotidianas , Brazo , Estudios Transversales , Evaluación de la Discapacidad , Metabolismo Energético , Femenino , Humanos , Persona de Mediana Edad , Encuestas y Cuestionarios
20.
Arthritis Care Res (Hoboken) ; 63(4): 530-4, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21452265

RESUMEN

OBJECTIVE: Cardiovascular disease (CVD) is the leading cause of death in patients with rheumatoid arthritis (RA). Disease-modifying therapies that improve risk factors for CVD, such as dyslipidemia, are desired. This study used an electronic health record to determine if hydroxychloroquine (HCQ) use was associated with an improvement in lipid levels in an inception RA cohort. METHODS: All adult individuals with the initial diagnosis of RA between January 1, 2001, and March 31, 2008, were identified (n=1,539). Only patients with at least one lipid level post-RA diagnosis were included (n=706). Information on demographics, medical history, body mass index (BMI), laboratory measures, and medications were collected at office visits. Potential risk and protective factors for dyslipidemia were controlled for in linear mixed-effects regression models for low-density lipoprotein (LDL), high-density lipoprotein (HDL), total cholesterol, triglycerides, LDL/HDL, and total cholesterol/HDL. RESULTS: Patients were 69% women and 98% white, with a median age of 65 years and a median BMI of 29.8 kg/m2. In the adjusted regression models, HCQ use was associated with the following average differences in lipids: LDL decrease of 7.55 mg/dl (P<0.001), HDL increase of 1.02 mg/dl (P=0.20), total cholesterol decrease of 7.70 mg/dl (P=0.002), triglycerides decrease of 10.91 mg/dl (P=0.06), LDL/HDL decrease of 0.136 (P=0.008), and total cholesterol/HDL decrease of 0.191 (P=0.006), which were stable over time. CONCLUSION: Use of HCQ in this RA cohort was independently associated with a significant decrease in LDL, total cholesterol, LDL/HDL, and total cholesterol/HDL. Considering these results, its safety profile, and low cost, HCQ remains a valuable initial or adjunct therapy in this patient population at high risk for CVD.


Asunto(s)
Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Artritis Reumatoide/metabolismo , Hidroxicloroquina/uso terapéutico , Metabolismo de los Lípidos/efectos de los fármacos , Anciano , Artritis Reumatoide/sangre , Colesterol/biosíntesis , Colesterol/sangre , HDL-Colesterol/biosíntesis , HDL-Colesterol/sangre , LDL-Colesterol/biosíntesis , LDL-Colesterol/sangre , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad
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