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1.
Phys Rev Lett ; 131(4): 041002, 2023 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-37566836

RESUMEN

The LUX-ZEPLIN experiment is a dark matter detector centered on a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility in Lead, South Dakota, USA. This Letter reports results from LUX-ZEPLIN's first search for weakly interacting massive particles (WIMPs) with an exposure of 60 live days using a fiducial mass of 5.5 t. A profile-likelihood ratio analysis shows the data to be consistent with a background-only hypothesis, setting new limits on spin-independent WIMP-nucleon, spin-dependent WIMP-neutron, and spin-dependent WIMP-proton cross sections for WIMP masses above 9 GeV/c^{2}. The most stringent limit is set for spin-independent scattering at 36 GeV/c^{2}, rejecting cross sections above 9.2×10^{-48} cm at the 90% confidence level.

2.
J Chem Phys ; 157(15): 154903, 2022 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-36272811

RESUMEN

Intrinsically disordered proteins (IDPs) are essential components for the formation of membraneless organelles, which play key functional and regulatory roles within biological systems. These complex assemblies form and dissolve spontaneously over time via liquid-liquid phase separation of IDPs. Mutations in their amino acid sequence can alter their phase behavior, which has been linked to the emergence of severe diseases. We study the conformation and phase behavior of a low-complexity domain of heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1) using coarse-grained implicit solvent molecular dynamics simulations. We systematically analyze how these properties are affected by the number of aromatic residues within the examined sequences. We find a significant compaction of the chains and an increase in the critical temperature with an increasing number of aromatic residues. The local persistence length is determined in single-chain simulations, revealing strong sequence-specific variations along the chain contour. Comparing single-chain and condensed-state simulations, we find many more collapsed polymer conformations in the dilute systems, even at temperatures near the estimated θ-temperature of the solution. These observations strongly support the hypothesis that aromatic residues play a dominant role in condensation, which is further corroborated by a detailed analysis of the intermolecular contacts, and conversely that important properties of condensates are captured in coarse-grained simulations. Interestingly, we observe density inhomogeneities within the condensates near criticality, which are driven by electrostatic interactions. Finally, we find that the relatively small fraction of hydrophobic residues in the IDPs results in interfacial tensions, which are significantly lower compared to typical combinations of immiscible simple liquids.


Asunto(s)
Fenómenos Bioquímicos , Proteínas Intrínsecamente Desordenadas , Proteínas Intrínsecamente Desordenadas/química , Ribonucleoproteína Nuclear Heterogénea A1/metabolismo , Polímeros/química , Solventes
3.
Osteoporos Int ; 32(6): 1217-1219, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33903925

RESUMEN

In patients with surgical repair of a low-trauma hip fracture, zoledronic acid (ZA) reduced the risk of subsequent fractures regardless of pretreatment femoral neck and total hip bone mineral density (BMD). INTRODUCTION: Zoledronic acid reduces the risk of subsequent fractures after repair of a hip fracture. It is still unclear whether the benefits in fracture reduction with ZA depend upon hip bone mineral density at the time of fracture. METHODS: We preformed additional post hoc analyses of data from the HORIZON Recurrent Fracture Trial to determine if ZA treatment reduced the risk of new clinical fractures regardless of pretreatment BMD. We modeled femoral neck and total hip BMD as both continuous and dichotomous variables (BMD T-score above and below -2.5). RESULTS: There are no evidence that baseline femoral neck and total hip BMD modified the anti-fracture efficacy of ZA when pretreatment BMD was analyzed as a continuous or a dichotomous variable (interaction p-values > 0.20). The clinical fracture efficacy of ZA was similar among patients with pretreatment femoral neck BMD values above and below -2.5 (relative hazards = 0.60 and 0.67, respectively, interaction p-value = 0.95). A similar result was obtained using pretreatment total hip BMD values (relative hazards = 0.72 and 0.57, respectively, interaction p-value = 0.41). CONCLUSION: There data should provide more comfort in prescribing ZA after surgical repair of a hip fracture, regardless of pretreatment BMD.


Asunto(s)
Conservadores de la Densidad Ósea , Fracturas de Cadera , Densidad Ósea , Conservadores de la Densidad Ósea/uso terapéutico , Cuello Femoral/cirugía , Fracturas de Cadera/prevención & control , Fracturas de Cadera/cirugía , Humanos , Ácido Zoledrónico/uso terapéutico
4.
Osteoporos Int ; 32(3): 515-527, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32930851

RESUMEN

The associations between objective measures of sleep duration and bone outcomes in older men are unknown. No consistent, significant association was identified between sleep duration and bone mineral density (BMD) in the current analysis. However, future research should determine if vitamin D status modifies this relationship. INTRODUCTION: Prior studies, predominantly in women, reported that long and short self-reported sleep duration are associated with lower BMD. Associations between actigraphy-determined sleep duration and BMD or bone turnover markers (BTMs) in older men are unknown. METHODS: Men in The Osteoporotic Fractures in Men (MrOS) Study with wrist actigraphy and concurrent BMD assessment but without comorbidities affecting bone health were included. Sleep duration was considered as a continuous (N = 1926) and dichotomized variable where men were classified as getting the recommended (7-8 h/night; N = 478) or short (< 6 h/night; N = 577) sleep. The cross-sectional association between BMD, BTMs, and sleep duration was examined using a t test or linear regression, where appropriate, in unadjusted and adjusted models. RESULTS: There were no clinically or statistically significant differences in BMD at the L-spine, total hip, or femoral neck between men getting the recommended vs. short sleep duration, using actigraphy or self-reported sleep duration (all p ≥ 0.07). When sleep duration was considered as a continuous variable, femoral neck BMD was higher in men with longer self-reported sleep duration (ß = 0.006 ±0.003, p = 0.02), but this was not significant after further adjustment. In men with low 25OHD (< 20 ng/mL), longer actigraphy-determined sleep duration was associated with higher total hip BMD (ß = 0.016 ± 0.008; p = 0.04). Sleep duration and BTMs were not associated. CONCLUSION: Sleep duration was not associated with hip or L-spine BMD or BTMs in older men. Future research should determine if vitamin D status or other factors modify this relationship.


Asunto(s)
Densidad Ósea , Cuello Femoral , Anciano , Estudios Transversales , Femenino , Humanos , Masculino , Sueño , Vitamina D
5.
Phys Rev Lett ; 127(6): 061801, 2021 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-34420312

RESUMEN

We present limits on spin-independent dark matter-nucleon interactions using a 10.6 g Si athermal phonon detector with a baseline energy resolution of σ_{E}=3.86±0.04(stat)_{-0.00}^{+0.19}(syst) eV. This exclusion analysis sets the most stringent dark matter-nucleon scattering cross-section limits achieved by a cryogenic detector for dark matter particle masses from 93 to 140 MeV/c^{2}, with a raw exposure of 9.9 g d acquired at an above-ground facility. This work illustrates the scientific potential of detectors with athermal phonon sensors with eV-scale energy resolution for future dark matter searches.

6.
Phys Rev Lett ; 127(8): 081802, 2021 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-34477436

RESUMEN

The Cryogenic Dark Matter Search low ionization threshold experiment (CDMSlite) achieved efficient detection of very small recoil energies in its germanium target, resulting in sensitivity to lightly ionizing particles (LIPs) in a previously unexplored region of charge, mass, and velocity parameter space. We report first direct-detection limits calculated using the optimum interval method on the vertical intensity of cosmogenically produced LIPs with an electric charge smaller than e/(3×10^{5}), as well as the strongest limits for charge ≤e/160, with a minimum vertical intensity of 1.36×10^{-7} cm^{-2} s^{-1} sr^{-1} at charge e/160. These results apply over a wide range of LIP masses (5 MeV/c^{2} to 100 TeV/c^{2}) and cover a wide range of ßγ values (0.1-10^{6}), thus excluding nonrelativistic LIPs with ßγ as small as 0.1 for the first time.

7.
J Neurophysiol ; 123(2): 658-669, 2020 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-31875485

RESUMEN

The otolith organs play a critical role in detecting linear acceleration and gravity to control posture and balance. Some afferents that innervate these structures can be activated by sound and are at risk for noise overstimulation. A previous report demonstrated that noise exposure can abolish vestibular short-latency evoked potential (VsEP) responses and damage calyceal terminals. However, the stimuli that were used to elicit responses were weaker than those established in previous studies and may have been insufficient to elicit VsEP responses in noise-exposed animals. The goal of this study was to determine the effect of an established noise exposure paradigm on VsEP responses using large head-jerk stimuli to determine if noise induces a stimulus threshold shift and/or if large head-jerks are capable of evoking VsEP responses in noise-exposed rats. An additional goal is to relate these measurements to the number of calyceal terminals and hair cells present in noise-exposed vs. non-noise-exposed tissue. Exposure to intense continuous noise significantly reduced VsEP responses to large stimuli and abolished VsEP responses to small stimuli. This finding confirms that while measurable VsEP responses can be elicited from noise-lesioned rat sacculi, larger head-jerk stimuli are required, suggesting a shift in the minimum stimulus necessary to evoke the VsEP. Additionally, a reduction in labeled calyx-only afferent terminals was observed without a concomitant reduction in the overall number of calyces or hair cells. This finding supports a critical role of calretinin-expressing calyceal-only afferents in the generation of a VsEP response.NEW & NOTEWORTHY This study identifies a change in the minimum stimulus necessary to evoke vestibular short-latency evoked potential (VsEP) responses after noise-induced damage to the vestibular periphery and reduced numbers of calretinin-labeled calyx-only afferent terminals in the striolar region of the sacculus. These data suggest that a single intense noise exposure may impact synaptic function in calyx-only terminals in the striolar region of the sacculus. Reduced calretinin immunolabeling may provide insight into the mechanism underlying noise-induced changes in VsEP responses.


Asunto(s)
Calbindina 2 , Neuronas Aferentes/fisiología , Ruido/efectos adversos , Terminales Presinápticos/fisiología , Sáculo y Utrículo/fisiopatología , Potenciales Vestibulares Miogénicos Evocados/fisiología , Animales , Células Ciliadas Vestibulares/fisiología , Movimientos de la Cabeza/fisiología , Estimulación Física , Ratas , Ratas Long-Evans , Sáculo y Utrículo/lesiones
8.
Anal Chem ; 92(13): 8722-8731, 2020 07 07.
Artículo en Inglés | MEDLINE | ID: mdl-32285664

RESUMEN

Worldwide, multiresistant bacterial strains are emerging at unprecedented rates. This development seriously threatens the ability of humanity to treat even common infections, resulting in disability and death. Furthermore, this development endangers all medical achievements including cancer therapy or organ transplantations. Therefore, the World Health Organization has endorsed antimicrobial resistance as a great threat to humanity. To still allow effective treatment of patients, rapid, automated, and reliable antibiotic susceptibility testing (AST) of bacterial pathogens is essential. Thereby, speed and sensitivity of the AST results are crucial for improving patient care. Here, Raman spectroscopy as a nondestructive technique providing chemical-specific information is employed to monitor the deuterium uptake of metabolically active bacteria during antibiotic treatment, enabling fast and reliable AST. For this purpose, a bulk sample-preparation method was developed, allowing a high-throughput analysis of a significant number of cells. A protocol was developed for Gram-positive (Enterococcus faecalis) and Gram-negative (Escherichia coli) reference strains and was tested on 51 clinical isolates with well-characterized resistance phenotypes against ampicillin, ciprofloxacin, meropenem, and vancomycin. Borderline resistant and heteroresistant phenotypes were observed and further investigated. This is of critical importance as the sensitive detection of low-frequency heteroresistance in bacterial populations is a huge challenge. Such isolates seem susceptible but are resistant to treatment in vivo. Automatable analysis detects strong phenotypes within 3 h. On the basis of experimental and modeled data, heteroresistance is estimated to be detectable down to frequencies of 10-6 and investigated on clinical isolates as a proof-of-concept study, but requiring longer incubation time.


Asunto(s)
Farmacorresistencia Bacteriana , Pruebas de Sensibilidad Microbiana/métodos , Espectrometría Raman , Antibacterianos/farmacología , Deuterio/química , Deuterio/metabolismo , Enterococcus faecalis/efectos de los fármacos , Enterococcus faecalis/aislamiento & purificación , Escherichia coli/efectos de los fármacos , Escherichia coli/aislamiento & purificación , Humanos
9.
Anal Chem ; 91(1): 881-887, 2019 01 02.
Artículo en Inglés | MEDLINE | ID: mdl-30507163

RESUMEN

Tuberculosis is currently the single most deadly infectious disease in the world and a public health priority as defined by WHO. Although the disease is in general curable, treatment success is hampered by the necessity of a long and side effect prone treatment. Low treatment efficiency may be partly due to the special growth states that mycobacteria enter to avoid being killed by antibiotics and to persist longer within the host. Such growth states have been recently defined as dormant or persistent. We produced dormant model-organism cultures using an acidification model and characterized those by a multilayered approach using mass spectrometry (MALDI-TOF), microscopy (SEM, Raman), and microbiological techniques (CFU, OD600, ATP-levels). With a fast and 96-well-adapted extraction protocol, mycobacteria could be inactivated and extracted for MALDI-TOF analysis. For the first time, we demonstrate growth-state-dependent changes in the mass signatures of the culture, allowing for a reliable differentiation of dormant state and exponential growth. We also demonstrate resuscitation from dormant state back to exponential growth. Viable mycobacteria were immobilized, and single organisms were analyzed individually by Raman microscopy. For single-cell Raman microscopy, Mycobacterium smegmatis cultures were fixed using a new fast and gentle single-step immobilization technique on a hydrophobic glass slide. We were able to distinguish single viable bacteria in the dormant state from their rapidly growing, genetically identical counterparts, identifying the growth state of the culture based on single-organism spectra. This allows for the separation of heterogeneous cultures depending on their growth state using the destruction-free optical method of Raman microscopy.


Asunto(s)
Técnicas Bacteriológicas/métodos , Mycobacterium smegmatis/clasificación , Mycobacterium smegmatis/crecimiento & desarrollo , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Espectrometría Raman/métodos , Análisis por Conglomerados , Análisis de Componente Principal
10.
Opt Express ; 27(22): 31465-31474, 2019 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-31684382

RESUMEN

We report a semiconductor saturable absorber mirror (SESAM)-modelocked thin-disk laser oscillator delivering a record 350-W average output power with 940-fs, 39-µJ pulses at 8.88-MHz repetition rate and 37-MW peak power. This oscillator is based on the Yb:YAG gain material and has a large pump spot on the disk. The cavity design includes an imaging scheme, which results in multiple reflections on the disk gain medium to enable a larger output coupling rate compared to those used in thin-disk oscillators with a single reflection on the disk. This reduces the intracavity power for a given output power, thus decreasing the stress on the intracavity components. We operate the laser in a low-pressure environment in order to limit the disk's thermal lensing and drastically reduce the nonlinearity picked up in the intracavity air medium. The combination of the imaging scheme and low-pressure operation paves the way to further power scaling of ultrafast thin-disk oscillators toward the kW milestone.

11.
Osteoporos Int ; 30(6): 1287-1295, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30809724

RESUMEN

The paper focuses on the identification of atypical fractures (AFFs). This paper examines the concordance between objective classification and expert subjective review. We believe the paper adds critical information about how to apply the American Society of Bone and Mineral Research (ASBMR) criteria to diagnose AFFs and is of high interest to the field. INTRODUCTION: Assess American Society of Bone and Mineral Research (ASBMR) criteria for identifying atypical femoral fractures (AFFs). METHODS: Two orthopedic surgeons independently evaluated radiographs of 372 fractures, applying ASBMR criteria. We assessed ease of applying ASBMR criteria and whether criteria-based assessment matched qualitative expert assessment. RESULTS: There was up to 27% uncertainty about how to classify specific features. 84% of films were classified similarly for the presence of AFF according to ASBMR criteria; agreement increased to 94% after consensus meeting. Of 37 fractures categorized as AFFs based on ASBMR criteria, 23 (62.2%) were considered AFFs according to expert assessment (not relying on criteria). Only one (0.5%) femoral shaft fracture that did not meet ASBMR criteria was considered an AFF per expert assessment. The number of major ASBMR features present (four vs five) and whether there was periosteal or endosteal thickening ("beaking" or "flaring") played major roles in the discrepancies between ASBMR criteria-based and expert-based determinations. CONCLUSIONS: ASBMR AFF criteria were useful for reviewers but several features were difficult to interpret. Expert assessments did not agree with the ASBMR classification in almost one-third of cases, but rarely identified an AFF when a femoral shaft fracture did not meet ASBMR AFF criteria. Experts identified lateral cortical transverse fracture line and associated new-bone formation along with no or minimal comminution as crucial features necessary for the definition of atypical femoral fractures.


Asunto(s)
Fracturas del Fémur/diagnóstico por imagen , Comités Consultivos , Anciano , Conservadores de la Densidad Ósea/efectos adversos , Competencia Clínica , Difosfonatos/efectos adversos , Registros Electrónicos de Salud , Testimonio de Experto , Femenino , Fracturas del Fémur/inducido químicamente , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Radiografía
13.
Pediatr Hematol Oncol ; 36(8): 494-503, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31633441

RESUMEN

Growth failure (GF) is a frequent problem after pediatric allogeneic hematopoietic stem cell transplantation (HSCT). Growth hormone deficiency (GHD) occurs in 20 to 85%, but published data on the efficacy of growth hormone treatment (GHT) are conflicting. Currently, there are no recommendations on screening for and treatment of GHD after HSCT. We aimed to describe the management of endocrine follow-up (FU)and details of GHT within European Society for Blood and Marrow Transplantation (EBMT) centers.In a retrospective questionnaire study, all EBMT centers performing pediatric HSCT were invited. Results were evaluated in correlation with the structure of endocrine aftercare (HSCT-clinicians and endocrinologists).The majority of centers (80%) reported endocrine FU by an endocrinologist - either within the HSCT-center or in a separate endocrine clinic. Fifty-four percent reported FU outside of the HSCT-center. As diagnostic tests the insulin-like growth factor IGF-I and insulin-like growth factor binding protein IGFBP3, insulin tolerance test and arginine stimulation test were most frequently used. Sixty-four percent of centers performed GHT and endocrinologists were more likely to prescribe GH (74%) compared to HSCT-clinicians (33%). The most frequent indication for GHT was GHD in 60%, with a distinct different approach of endocrinologists in comparison with HSCT-clinicians.Our study reveals substantial variation in practice and emphasizes the need for endocrine aftercare performed by dedicated endocrinologists in close collaboration with the HSCT-center. Our results indicate that the management of GHT depends on the structure of endocrine aftercare, which is important for the future development and distribution of studies and guidelines.


Asunto(s)
Hormona del Crecimiento/deficiencia , Trasplante de Células Madre Hematopoyéticas/métodos , Acondicionamiento Pretrasplante/métodos , Trasplante Homólogo/métodos , Endocrinólogos , Femenino , Humanos , Masculino , Estudios Retrospectivos , Encuestas y Cuestionarios
14.
J Intern Med ; 283(1): 56-72, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29034571

RESUMEN

BACKGROUND: Subclinical hyperthyroidism (SHyper) has been associated with increased risk of hip and other fractures, but the linking mechanisms remain unclear. OBJECTIVE: To investigate the association between subclinical thyroid dysfunction and bone loss. METHODS: Individual participant data analysis was performed after a systematic literature search in MEDLINE/EMBASE (1946-2016). Two reviewers independently screened and selected prospective cohorts providing baseline thyroid status and serial bone mineral density (BMD) measurements. We classified thyroid status as euthyroidism (thyroid-stimulating hormone [TSH] 0.45-4.49 mIU/L), SHyper (TSH < 0.45 mIU/L) and subclinical hypothyroidism (SHypo, TSH ≥ 4.50-19.99 mIU/L) both with normal free thyroxine levels. Our primary outcome was annualized percentage BMD change (%ΔBMD) from serial dual X-ray absorptiometry scans of the femoral neck, total hip and lumbar spine, obtained from multivariable regression in a random-effects two-step approach. RESULTS: Amongst 5458 individuals (median age 72 years, 49.1% women) from six prospective cohorts, 451 (8.3%) had SHypo and 284 (5.2%) had SHyper. During 36 569 person-years of follow-up, those with SHyper had a greater annual bone loss at the femoral neck versus euthyroidism: %ΔBMD = -0.18 (95% CI: -0.34, -0.02; I2 = 0%), with a nonstatistically significant pattern at the total hip: %ΔBMD = -0.14 (95% CI: -0.38, 0.10; I2 = 53%), but not at the lumbar spine: %ΔBMD = 0.03 (95% CI: -0.30, 0.36; I2 = 25%); especially participants with TSH < 0.10 mIU/L showed an increased bone loss in the femoral neck (%Δ BMD = -0.59; [95% CI: -0.99, -0.19]) and total hip region (%ΔBMD = -0.46 [95% CI: -1.05, -0.13]). In contrast, SHypo was not associated with bone loss at any site. CONCLUSION: Amongst adults, SHyper was associated with increased femoral neck bone loss, potentially contributing to the increased fracture risk.


Asunto(s)
Densidad Ósea , Fracturas Óseas , Hipertiroidismo , Hipotiroidismo , Anciano , Enfermedades Asintomáticas , Femenino , Fracturas Óseas/etiología , Fracturas Óseas/metabolismo , Fracturas Óseas/prevención & control , Humanos , Hipertiroidismo/diagnóstico , Hipertiroidismo/epidemiología , Hipertiroidismo/metabolismo , Hipotiroidismo/diagnóstico , Hipotiroidismo/epidemiología , Hipotiroidismo/metabolismo , Masculino , Factores de Riesgo
15.
Osteoporos Int ; 29(3): 699-705, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29204959

RESUMEN

Bone composition evaluated by FTIRI analysis of iliac crest biopsies from post-menopausal women treated with alendronate for 10 years, continuously or alendronate for 5 years, followed by a 5-year alendronate-holiday, only differed with the discontinued biopsies having increased cortical crystallinity and heterogeneity of acid phosphate substitution and decreased trabecular crystallinity heterogeneity. INTRODUCTION: Bisphosphonates (BP) are the most commonly used and effective drugs to prevent fragility fractures; however, concerns exist that prolonged use may lead to adverse events. Recent recommendations suggest consideration of a BP "holiday" in individuals taking long-term BP therapy not at high risk of fracture. Data supporting or refuting this recommendation based on bone quality are limited. We hypothesized that a "holiday" of 5 years would cause no major bone compositional changes. METHODS: We analyzed the 31 available biopsies from the FLEX-Long-term Extension of FIT (Fracture Intervention Trial) using Fourier transform infrared imaging (FTIRI). Biopsies from two groups of post-menopausal women, a "Continuously treated group" (N = 16) receiving alendronate for ~ 10 years and a "Discontinued group" (N = 15), alendronate treated for 5 years taking no antiresorptive medication during the following 5 years. Iliac crest bone biopsies were provided at 10 years. RESULTS: Key FTIRI parameters, mineral-to-matrix ratio, carbonate-to-phosphate ratio, acid phosphate substitution, and collagen cross-link ratio as well as heterogeneity of these parameters were similar for Continuously treated and Discontinued groups in age-adjusted models. The Discontinued group had 2% greater cortical crystallinity (p = 0.01), 31% greater cortical acid phosphate heterogeneity (p = 0.02), and 24% lower trabecular crystallinity heterogeneity (p = 0.02). CONCLUSIONS: Discontinuation of alendronate for 5 years did not affect key FTIRI parameters, supporting the hypothesis that discontinuation would have little impact on bone composition. Modest differences were observed in three parameters that are not likely to affect bone mechanical properties. These preliminary data suggest that a 5-year BP holiday is not harmful to bone composition.


Asunto(s)
Alendronato/administración & dosificación , Conservadores de la Densidad Ósea/administración & dosificación , Osteoporosis Posmenopáusica/tratamiento farmacológico , Anciano , Alendronato/farmacología , Alendronato/uso terapéutico , Biopsia , Densidad Ósea/efectos de los fármacos , Conservadores de la Densidad Ósea/farmacología , Conservadores de la Densidad Ósea/uso terapéutico , Método Doble Ciego , Femenino , Estudios de Seguimiento , Humanos , Ilion/efectos de los fármacos , Ilion/patología , Osteoporosis Posmenopáusica/patología , Osteoporosis Posmenopáusica/fisiopatología , Fracturas Osteoporóticas/prevención & control , Privación de Tratamiento
16.
Osteoporos Int ; 29(1): 49-59, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29090329

RESUMEN

Among older men, characteristics that predict longitudinal changes in trabecular bone score (TBS) are different from characteristics that predict changes in bone mineral density (BMD). Most notably, weight loss is strongly associated with concomitant loss in BMD but with concomitant increases in TBS, when measured on Hologic densitometers. INTRODUCTION: Our objective was to compare and contrast predictors of changes in TBS, total hip BMD, and lumbar spine BMD. METHODS: Our study population was 3969 Osteoporotic Fractures in Men (MrOS) cohort participants (mean age 72.8 years) with repeat measures of TBS, lumbar spine and total hip BMD, body mass index (BMI) less than 37 kg/m2, and no use of bisphosphonate or glucocorticoid medications. TBS was scored (Med-Imaps Software version 2.1) and BMD measured on Hologic densitometers. RESULTS: One thousand four hundred forty-four men had a TBS decrease > 0.04 units (estimated least significant change for TBS), 795 men had a TBS increase > 0.04 units, and 1730 men had TBS change ≤ 0.04 units over mean follow-up of 4.6 years. Older age was not associated with TBS change, but was associated with greater decline in lumbar spine and total hip BMD. Compared to stable weight, > 10% weight loss was strongly associated with an increase in TBS [effect size = 1.24 (95% CI 1.12, 1.36)] and strongly associated with a decrease in total hip BMD [- 1.16 (95% CI - 1.19, - 1.03)]. Other predictors discordant for longitudinal changes of TBS and BMD included baseline BMI, walk speed, and ACE inhibitor use. CONCLUSIONS: Predictors of changes in TBS are different from predictors of changes in lumbar spine and total hip BMD. At least when assessed on Hologic densitometers, weight loss is associated with subsequent declines in spine and total hip BMD but subsequent increase in TBS. Faster walk speed may protect against loss of hip BMD, but is not associated with longitudinal changes of TBS.


Asunto(s)
Densidad Ósea/fisiología , Hueso Esponjoso/fisiopatología , Fracturas Osteoporóticas/fisiopatología , Absorciometría de Fotón/métodos , Anciano , Índice de Masa Corporal , Hueso Esponjoso/diagnóstico por imagen , Estudios de Seguimiento , Articulación de la Cadera/fisiopatología , Humanos , Vértebras Lumbares/fisiopatología , Masculino , Osteoporosis/diagnóstico por imagen , Osteoporosis/fisiopatología , Fracturas Osteoporóticas/diagnóstico por imagen , Estudios Prospectivos , Fracturas de la Columna Vertebral/diagnóstico por imagen , Fracturas de la Columna Vertebral/fisiopatología , Pérdida de Peso/fisiología
17.
Osteoporos Int ; 29(1): 69-77, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29063213

RESUMEN

Dairy protein but not plant protein was associated with bone strength of the radius and tibia in older men. These results are consistent with previous results in women and support similar findings related to fracture outcomes. Bone strength differences were largely due to thickness and area of the bone cortex. INTRODUCTION: Our objective was to determine the association of protein intake by source (dairy, non-dairy animal, plant) with bone strength and bone microarchitecture among older men. METHODS: We used data from 1016 men (mean 84.3 years) who attended the Year 14 exam of the Osteoporotic Fractures in Men (MrOS) study, completed a food frequency questionnaire (500-5000 kcal/day), were not taking androgen or androgen agonists, and had high-resolution peripheral quantitative computed tomography (HR-pQCT) scans of the distal radius and distal or diaphyseal tibia. Protein was expressed as percentage of total energy intake (TEI); mean ± SD for TEI = 1548 ± 607 kcal/day and for total protein = 16.2 ± 2.9%TEI. We used linear regression with standardized HR-pQCT parameters as dependent variables and adjusted for age, limb length, center, education, race/ethnicity, marital status, smoking, alcohol intake, physical activity level, corticosteroids use, supplement use (calcium and vitamin D), and osteoporosis medications. RESULTS: Higher dairy protein intake was associated with higher estimated failure load at the distal radius and distal tibia [radius effect size = 0.17 (95% CI 0.07, 0.27), tibia effect size = 0.13 (95% CI 0.03, 0.23)], while higher non-dairy animal protein was associated with higher failure load at only the distal radius. Plant protein intake was not associated with failure load at any site. CONCLUSION: The association between protein intake and bone strength varied by source of protein. These results support a link between dairy protein intake and skeletal health, but an intervention study is needed to evaluate causality.


Asunto(s)
Densidad Ósea/efectos de los fármacos , Proteínas en la Dieta/administración & dosificación , Radio (Anatomía)/fisiología , Tibia/fisiología , Anciano , Anciano de 80 o más Años , Fenómenos Biomecánicos , Estudios Transversales , Proteínas en la Dieta/farmacología , Conducta Alimentaria , Humanos , Masculino , Proteínas de la Leche/administración & dosificación , Proteínas de la Leche/farmacología , Proteínas de Vegetales Comestibles/administración & dosificación , Proteínas de Vegetales Comestibles/farmacología , Tomografía Computarizada por Rayos X/métodos
18.
Phys Rev Lett ; 120(6): 061802, 2018 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-29481237

RESUMEN

We report the result of a blinded search for weakly interacting massive particles (WIMPs) using the majority of the SuperCDMS Soudan data set. With an exposure of 1690 kg d, a single candidate event is observed, consistent with expected backgrounds. This analysis (combined with previous Ge results) sets an upper limit on the spin-independent WIMP-nucleon cross section of 1.4×10^{-44} (1.0×10^{-44}) cm^{2} at 46 GeV/c^{2}. These results set the strongest limits for WIMP-germanium-nucleus interactions for masses >12 GeV/c^{2}.

19.
Phys Rev Lett ; 121(5): 051301, 2018 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-30118251

RESUMEN

We present the first limits on inelastic electron-scattering dark matter and dark photon absorption using a prototype SuperCDMS detector having a charge resolution of 0.1 electron-hole pairs (CDMS HVeV, a 0.93 g CDMS high-voltage device). These electron-recoil limits significantly improve experimental constraints on dark matter particles with masses as low as 1 MeV/c^{2}. We demonstrate a sensitivity to dark photons competitive with other leading approaches but using substantially less exposure (0.49 g d). These results demonstrate the scientific potential of phonon-mediated semiconductor detectors that are sensitive to single electronic excitations.

20.
Haemophilia ; 24(2): 307-315, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29271607

RESUMEN

INTRODUCTION: Haemophilic ankle arthropathy is caused by recurrent spontaneous joint haemorrhaging and leads to pain, deformity and loss of function. In the presence of advanced articular deterioration, therapeutic options are confined to either arthroplasty or arthrodesis, the latter still being referred to as the procedure of choice. However, total ankle replacement (TAR) has recently gained acceptance as an alternative. AIM: To investigate the mid- to long-term results of TAR in haemophilic ankle arthropathy. MATERIALS AND METHODS: Seventeen TARs in 14 male patients (mean age: 43 years [range, 27.4-57.6]), implanted between 1998 and 2012, were retrospectively analysed. Implant survival was estimated using Kaplan-Meier analysis. Haemophilic/viral status, complications and revision surgeries were recorded. Follow-up assessment of 12 TARs was performed 9.6 years (range, 3.3-17.8) postoperatively, including clinical examination, pain and satisfaction scales, the American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score, and the SF-36. Radiographic evaluation of pre- and follow-up radiographs was conducted. RESULTS: Estimated implant survival was 94% at 5, 85% at 10 and 70% at 15 years, respectively. Three cases required revision surgery. At follow-up, 9.6 years (range, 3.3-17.8) postoperatively, the level of satisfaction was 76% (range, 50-100) and of pain 2/10 (range, 0-6) on the VAS. Range of motion had increased significantly (P = .037). The SF-36 summary scores were comparable to those of a matched standard population. The AOFAS hindfoot score averaged 81 points (range, 73-90). All radiographs revealed component loosening or periprosthetic radiolucency. CONCLUSION: Total ankle replacement in the presence of advanced haemophilic arthropathy is a viable treatment option with favourable mid-/long-term results, maintaining mobility of the ankle joint.


Asunto(s)
Artroplastia de Reemplazo de Tobillo/métodos , Hemofilia A/complicaciones , Adulto , Femenino , Estudios de Seguimiento , Hemofilia A/patología , Humanos , Masculino , Persona de Mediana Edad , Factores de Tiempo
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