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1.
Eur J Neurol ; 27(1): 100-104, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31309642

RESUMO

BACKGROUND AND PURPOSE: Tapering immunosuppressants is desirable in patients with well-controlled myasthenia gravis (MG). However, the association between tapering of calcineurin inhibitor dosage and reduction-associated exacerbation is not known. The aim of this study was to clarify the frequency of reduction-associated exacerbation when tacrolimus is tapered in stable patients with anti-acetylcholine receptor antibody-positive MG, and to determine the factors that predict exacerbations. METHODS: We retrospectively analyzed 115 patients in whom tacrolimus dosage was tapered. The reduction-associated exacerbation was defined as the appearance or worsening of one or more MG symptoms <3 months after the reduction. RESULTS: Tacrolimus dosage was successfully tapered in 110 patients (96%) without any exacerbation. Five patients (4%) experienced an exacerbation, but symptoms were reversed in all patients when the tacrolimus dose was increased to the previous maintenance level. No patient developed an MG crisis. The age at onset was significantly earlier (30 vs. 56 years, P = 0.025) and the reduction in dosage was significantly larger (2.0 vs. 1.0 mg/day, P = 0.002) in patients with reduction-associated exacerbation than in those without exacerbation. The cut-off values determined in a receiver-operating characteristic curve analysis were 52 years (sensitivity, 57%; specificity, 100%) for the age at onset and 1.5 mg (sensitivity, 80%; specificity, 100%) for the dose reduction. CONCLUSION: Tapering of tacrolimus was possible in most patients with well-controlled anti-acetylcholine receptor antibody-positive MG. Early age at onset and a large reduction from maintenance dosage were associated with exacerbation. Reductions ≤1.5 mg/day from the maintenance dosage should be considered for patients with late-onset disease.


Assuntos
Imunossupressores/administração & dosagem , Imunossupressores/uso terapêutico , Miastenia Gravis/tratamento farmacológico , Miastenia Gravis/imunologia , Receptores Colinérgicos/imunologia , Tacrolimo/administração & dosagem , Tacrolimo/uso terapêutico , Adulto , Idade de Início , Anticorpos/análise , Redução da Medicação , Feminino , Humanos , Imunossupressores/efeitos adversos , Masculino , Pessoa de Meia-Idade , Curva ROC , Estudos Retrospectivos , Sensibilidade e Especificidade , Tacrolimo/efeitos adversos
2.
Osteoporos Int ; 29(9): 2121-2127, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29947865

RESUMO

Postmenopausal (PM) women using inhaled glucocorticoids (IGCs) had substantial abnormalities in volumetric BMD (vBMD), microarchitecture, and stiffness using high resolution peripheral computed tomography (HRpQCT) compared to age- and race-matched controls. Abnormalities were most severe at the radius. These preliminary results suggest that there may be major, heretofore unrecognized, skeletal deficits in PM women using IGCs. INTRODUCTION: While oral glucocorticoids are well recognized to have destructive skeletal effects, less is known about the effects of IGCs. The detrimental skeletal effects of IGCs may be greatest in PM women, in whom they compound negative effects of estrogen loss and aging. The goal of this study was to evaluate microarchitecture and stiffness in PM women using chronic IGCs. METHODS: This case-control study compared PM women using IGCs for ≥ 6 months (n = 20) and controls matched for age and race/ethnicity (n = 60). Skeletal parameters assessed included areal BMD (aBMD) by DXA, trabecular and cortical vBMD and microarchitecture by HRpQCT of the radius and tibia, and whole bone stiffness by finite element analysis. RESULTS: By DXA, mean values in both groups were in the osteopenic range; hip aBMD was lower in IGC users (P < 0.04). By HRpQCT, IGC users had lower total, cortical, and trabecular vBMD at both radius and tibia (all P < 0.05). IGC users had lower cortical thickness, lower trabecular number, greater trabecular separation and heterogeneity at the radius (all P < 0.03), and greater heterogeneity at the tibia (P < 0.04). Whole bone stiffness was lower in IGC users at radius (P < 0.03) and tended to be lower at the tibia (P = 0.09). CONCLUSIONS: PM women using IGCs had substantial abnormalities in vBMD, microarchitecture, and stiffness compared to controls. These abnormalities were most severe at the radius. These preliminary results suggest that there may be major, heretofore unrecognized, skeletal deficits in PM women using IGCs.


Assuntos
Glucocorticoides/efeitos adversos , Osteoporose Pós-Menopausa/induzido quimicamente , Absorciometria de Fóton/métodos , Administração por Inalação , Idoso , Densidade Óssea/efeitos dos fármacos , Estudos de Casos e Controles , Esquema de Medicação , Elasticidade/efeitos dos fármacos , Feminino , Glucocorticoides/administração & dosagem , Glucocorticoides/farmacologia , Humanos , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/fisiopatologia , Rádio (Anatomia)/fisiopatologia , Tíbia/fisiopatologia , Tomografia Computadorizada por Raios X
3.
Osteoporos Int ; 29(11): 2581, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30155687

RESUMO

The second name of the ninth author, X.E. Guo, was incorrectly coded as part of his surname. The publisher apologises for the inconvenience caused.

4.
Osteoporos Int ; 29(4): 871-879, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29387910

RESUMO

We found that HIV+/HCV+ women had 7-8% lower areal bone mineral density (aBMD) by dual-energy x-ray absorptiometry (DXA) at the spine, hip, and radius (p < 0.01) and 5-7% lower volumetric BMD (vBMD) by central quantitative computed tomography (cQCT) at the spine and hip (p < 0.05). These data suggest that true deficits in vBMD may contribute to bone fragility and excess fractures reported in HIV+/HCV+ women. INTRODUCTION: aBMD by DXA is lower in persons coinfected with HIV and HCV (HIV+/HCV+) than with HIV monoinfection (HIV+). However, weight is often also lower with HCV infection, and measurement of aBMD by DXA can be confounded by adiposity; we aimed to determine whether true vBMD is also lower in HIV+/HCV+ coinfection. METHODS: We measured aBMD of the lumbar spine (LS), total hip (TH), femoral neck (FN), and ultradistal radius (UDR) by DXA and vBMD of the spine and hip by cQCT and of the distal radius and tibia by high-resolution peripheral QCT (HRpQCT) in 37 HIV+/HCV+ and 119 HIV+ postmenopausal women. Groups were compared using Student's t tests with covariate adjustment by multiple regression analysis. RESULTS: HIV+/HCV+ and HIV+ women were of similar age and race/ethnicity. HIV+/HCV+ women had lower body mass index (BMI) and trunk fat and were more likely to smoke and less likely to have a history of AIDS. In HIV+/HCV+ women, aBMD by DXA was 7-8% lower at the LS, TH, and UDR (p < 0.01). Similarly, vBMD by cQCT was 5-7% lower at the LS and TH (p < 0.05). Between-group differences in LS aBMD and vBMD remained significant after adjustment for BMI, smoking, and AIDS history. Tibial total vBMD by HRpQCT was 10% lower in HIV+/HCV+ women. CONCLUSION: HIV+/HCV+ postmenopausal women had significantly lower spine aBMD and vBMD. These deficits in vBMD may contribute to bone fragility and excess fractures reported in HIV+/HCV+ women.


Assuntos
Coinfecção/complicações , Infecções por HIV/complicações , Hepatite C/complicações , Osteoporose Pós-Menopausa/virologia , Absorciometria de Fóton/métodos , Negro ou Afro-Americano/estatística & dados numéricos , Densidade Óssea/fisiologia , Coinfecção/etnologia , Coinfecção/fisiopatologia , Feminino , Infecções por HIV/etnologia , Infecções por HIV/fisiopatologia , Hepatite C/fisiopatologia , Articulação do Quadril/diagnóstico por imagem , Articulação do Quadril/fisiopatologia , Hispânico ou Latino/estatística & dados numéricos , Humanos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/fisiopatologia , Pessoa de Meia-Idade , Grupos Minoritários/estatística & dados numéricos , Osteoporose Pós-Menopausa/diagnóstico por imagem , Osteoporose Pós-Menopausa/etnologia , Osteoporose Pós-Menopausa/fisiopatologia , Rádio (Anatomia)/diagnóstico por imagem , Rádio (Anatomia)/fisiopatologia , Tíbia/diagnóstico por imagem , Tíbia/fisiopatologia , Tomografia Computadorizada por Raios X/métodos , Estados Unidos/epidemiologia
5.
Osteoporos Int ; 28(7): 2147-2154, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28341899

RESUMO

Hispanic men have smaller bone size but thicker and denser cortices compared to white men, leading to similar mechanical competence. INTRODUCTION: The purpose of this study was to assess differences in vBMD and microarchitecture in young Caribbean Hispanic (n = 30) and non-Hispanic Caucasian (n = 30) men. METHODS: We measured areal bone mineral density (aBMD) at the spine, total hip (TH), femoral neck (FN), and forearm by dual-energy X-ray absorptiometry (DXA) and bone geometry, mass, microarchitecture, and mechanical competence by high-resolution peripheral quantitative computed tomography (HRpQCT), individual trabecula segmentation (ITS), and finite element analysis (FEA). RESULTS: Hispanic men were slightly older, shorter, and heavier and had higher BMI compared with white men. aBMD, measured by DXA, did not differ at the spine, TH, or forearm before or after adjustment for age, height, weight, and the interaction of height and weight. At the FN, marginally significant higher BMD in Hispanics prior to adjustment was attenuated and no longer differed after adjustment for covariates. Adjusted HRpQCT indices indicated smaller total and trabecular area at the radius but greater total volumetric density and cortical thickness in Hispanic versus white men. The adjusted difference in cortical density at the radius was of borderline significance. Trabecular and ITS microstructure tended not to differ at the radius. At the tibia, results were similar. Bone size tended to be smaller and covariate-adjusted cortical density and cortical thickness were greater in Hispanic versus white men. Additionally, cortical porosity was lower at the tibia in Hispanic compared to white men. Stiffness and failure load did not differ at either skeletal site by ethnicity. CONCLUSION: In conclusion, greater cortical thickness and density as well as lower cortical porosity tend to compensate for smaller bone size in Hispanic men, leading to similar mechanical competence compared with white men.


Assuntos
Densidade Óssea/fisiologia , Hispânico ou Latino/estatística & dados numéricos , Absorciometria de Fóton , Adulto , Antropometria/métodos , Colo do Fêmur/fisiologia , Análise de Elementos Finitos , Articulação do Quadril/fisiologia , Humanos , Vértebras Lombares/fisiologia , Masculino , Rádio (Anatomia)/anatomia & histologia , Rádio (Anatomia)/fisiologia , Tíbia/anatomia & histologia , Tíbia/fisiologia , Tomografia Computadorizada por Raios X , População Branca/estatística & dados numéricos
6.
Osteoporos Int ; 28(2): 549-558, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27638138

RESUMO

This is a cross-sectional study to assess differences in bone quality in young Asian and Caucasian (n = 30/group) men between 25 and 35 years. We found that Asians had smaller bones, thicker and denser cortices, and more plate-like trabeculae, but stiffness did not differ between groups. INTRODUCTION: We conducted a cross-sectional study to assess differences in bone quality in young Asian and Caucasian (n = 30/group) men between 25 and 35 years. METHODS: We measured bone mineral density (BMD) at the spine, total hip (TH), femoral neck (FN), and forearm by dual energy X-ray absorptiometry (DXA), and bone geometry, density, microarchitecture, and mechanical competence at the radius and tibia by high-resolution peripheral quantitative computed tomography (HR-pQCT) with application of individual trabecula segmentation (ITS) and trabecular and whole bone finite element analysis (FEA). We measured load-to-strength ratio to account for differences in bone size and height, respectively. We used Wilcoxon rank sum and generalized linear models adjusted for height, weight, and their interaction for comparisons. RESULTS: Asians were 3.9 % shorter and weighed 6.5 % less than Caucasians. In adjusted models: by DXA, there were no significant race-based differences in areal BMD; by HR-pQCT, at the radius, Asians had smaller total and trabecular area (p = 0.003 for both), and denser (p = 0.01) and thicker (p = 0.04) cortices at the radius; by ITS, at the radius Asians, had more plate-like than rod-like trabeculae (PR ratio p = 0.01), greater plate trabecular surface (p = 0.009) and longer rod length (p = 0.002). There were no significant race-based differences in FEA or the load-to-strength ratio. CONCLUSIONS: Asians had smaller bones, thicker and denser cortices, and more plate-like trabeculae, but biomechanical estimates of bone strength did not differ between groups. Studies are needed to determine whether these differences persist later in life.


Assuntos
Povo Asiático/estatística & dados numéricos , Densidade Óssea/fisiologia , População Branca/estatística & dados numéricos , Absorciometria de Fóton/métodos , Adulto , Estudos Transversais , Colo do Fêmur/anatomia & histologia , Colo do Fêmur/diagnóstico por imagem , Colo do Fêmur/fisiologia , Análise de Elementos Finitos , Articulação do Quadril/anatomia & histologia , Articulação do Quadril/diagnóstico por imagem , Articulação do Quadril/fisiologia , Humanos , Vértebras Lombares/anatomia & histologia , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/fisiologia , Masculino , Rádio (Anatomia)/anatomia & histologia , Rádio (Anatomia)/diagnóstico por imagem , Rádio (Anatomia)/fisiologia , Tomografia Computadorizada por Raios X/métodos
7.
Osteoporos Int ; 28(1): 245-257, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27475931

RESUMO

In this study, we determined that operator positioning precision contributes significant measurement error in high-resolution peripheral quantitative computed tomography (HR-pQCT). Moreover, we developed software to quantify intra- and inter-operator variability and demonstrated that standard positioning training (now available as a web-based application) can significantly reduce inter-operator variability. INTRODUCTION: HR-pQCT is increasingly used to assess bone quality, fracture risk, and anti-fracture interventions. The contribution of the operator has not been adequately accounted in measurement precision. Operators acquire a 2D projection ("scout view image") and define the region to be scanned by positioning a "reference line" on a standard anatomical landmark. In this study, we (i) evaluated the contribution of positioning variability to in vivo measurement precision, (ii) measured intra- and inter-operator positioning variability, and (iii) tested if custom training software led to superior reproducibility in new operators compared to experienced operators. METHODS: To evaluate the operator in vivo measurement precision, we compared precision errors calculated in 64 co-registered and non-co-registered scan-rescan images. To quantify operator variability, we developed software that simulates the positioning process of the scanner's software. Eight experienced operators positioned reference lines on scout view images designed to test intra- and inter-operator reproducibility. Finally, we developed modules for training and evaluation of reference line positioning. We enrolled six new operators to participate in a common training, followed by the same reproducibility experiments performed by the experienced group. RESULTS: In vivo precision errors were up to threefold greater (Tt.BMD and Ct.Th) when variability in scan positioning was included. The inter-operator precision errors were significantly greater than the short-term intra-operator precision (p < 0.001). New trained operators achieved comparable intra-operator reproducibility to experienced operators and lower inter-operator reproducibility (p < 0.001). Precision errors were significantly greater for the radius than for the tibia. CONCLUSION: Operator reference line positioning contributes significantly to in vivo measurement precision and is significantly greater for multi-operator datasets. Inter-operator variability can be significantly reduced using a systematic training platform, now available online ( http://webapps.radiology.ucsf.edu/refline/ ).


Assuntos
Competência Clínica , Osteoporose/diagnóstico por imagem , Tomografia Computadorizada por Raios X/normas , Idoso , Idoso de 80 Anos ou mais , Pontos de Referência Anatômicos , Feminino , Humanos , Capacitação em Serviço/métodos , Masculino , Rádio (Anatomia)/diagnóstico por imagem , Reprodutibilidade dos Testes , Design de Software , Tíbia/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos
8.
Osteoporos Int ; 27(10): 2955-66, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27155883

RESUMO

UNLABELLED: Bone strength is dependent on bone density and microstructure. High-resolution peripheral quantitative computed tomography (HR-pQCT) can measure microstructure but is somewhat limited due to its resolution. We compared a new HR-pQCT scanner to existing technology and found very good agreement for most parameters. This study will be important when interpreting results from different devices. INTRODUCTION: Recently, a second-generation HR-pQCT scanner (XCT2) has been developed with a higher nominal isotropic resolution (61 µm) compared to the first-generation device (XCT1, 82 µm). It is unclear how in vivo measurements from these two devices compare. In this study, we obtained and analyzed in vivo XCT1 and XCT2 measurements of bone microarchitecture and estimated strength. METHODS: We scanned 51 adults (16 men and 35 women, age 44.8 ± 16.0) on both XCT2 and XCT1 on the same day. We first compared XCT1 and XCT2 measurements obtained using their respective standard patient protocols. In XCT1, microarchitecture parameters were derived, while XCT2 measurements were directly measured. We also compared XCT2-D with XCT1 by finding the overlapping regions of interest and using the standard patient protocol for XCT1. RESULTS: We obtained excellent agreement between XCT1 and XCT2 for most of the volumetric bone mineral density (vBMD), trabecular and cortical measurements (All R (2) > 0.820) except for cortical porosity at the radius (R (2) = 0.638), trabecular number (R (2) = 0.694, 0.787) and trabecular thickness (R (2) = 0.569, 0.527) at both radius and tibia, respectively. XCT1 and XCT2-D measurements also had excellent agreement for most of the measurements (all R (2) > 0.870) except trabecular number (R (2) = 0.524, 0.706), trabecular thickness (R (2) = 0.758, 0.734) at both radius and tibia, respectively, and trabecular separation (R (2) = 0.656) at the radius. CONCLUSION: While some caution should be exercised for parameters that are more dependent on image resolution, results from our study indicate that second-generation scans can be compared to more widely available first-generation data and may be beneficial for multicenter and longitudinal studies using both scanner generations.


Assuntos
Densidade Óssea , Osso e Ossos/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Rádio (Anatomia) , Tíbia
9.
Epidemiol Infect ; 144(4): 787-95, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26243450

RESUMO

Although outbreaks of acute respiratory infection (ARI) at shelters are hypothesized to be associated with shelter crowding, no studies have examined this relationship. We conducted a retrospective study by reviewing medical records of evacuees presenting to one of the 37 clinics at the shelters in Ishinomaki city, Japan, during the 3-week period after the Great Eastern Japan Earthquake and tsunami in 2011. On the basis of a locally weighted scatter-plot smoothing technique, we categorized 37 shelters into crowded (mean space <5·5 m2/per person) and non-crowded (⩾5·5 m2) shelters. Outcomes of interest were the cumulative and daily incidence rate of ARI/10 000 evacuees at each shelter. We found that the crowded shelters had a higher median cumulative incidence rate of ARI [5·4/10 000 person-days, interquartile range (IQR) 0-24·6, P = 0·04] compared to the non-crowded shelters (3·5/10 000 person-days, IQR 0-8·7) using Mann-Whitney U test. Similarly, the crowded shelters had an increased daily incidence rate of ARI of 19·1/10 000 person-days (95% confidence interval 5·9-32·4, P < 0·01) compared to the non-crowded shelters using quasi-least squares method. In sum, shelter crowding was associated with an increased incidence rate of ARI after the natural disaster.


Assuntos
Aglomeração , Surtos de Doenças , Espaço Pessoal , Infecções Respiratórias/epidemiologia , Doença Aguda , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Desastres , Terremotos , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Infecções Respiratórias/etiologia , Estudos Retrospectivos , Tsunamis , Adulto Jovem
10.
Osteoporos Int ; 25(2): 619-26, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23948875

RESUMO

UNLABELLED: We used quantitative computed tomography and finite element analysis to classify women with and without hip fracture. Highly accurate classifications were achieved indicating the potential for these methods to be used for subject-specific assessment of fracture risk. INTRODUCTION: Areal bone mineral density (aBMD) is the current clinical diagnostic standard for assessing fracture risk; however, many fractures occur in people not defined as osteoporotic by aBMD. Finite element (FE) analysis based on quantitative computed tomography (QCT) images takes into account both bone material and structural properties to provide subject-specific estimates of bone strength. Thus, our objective was to determine if FE estimates of bone strength could classify women with and without hip fracture. METHODS: Twenty women with femoral neck fracture and 15 women with trochanteric fractures along with 35 age-matched controls were scanned with QCT at the hip. Since it is unknown how a specific subject will fall, FE analysis was used to estimate bone stiffness and bone failure load under loading configurations with femoral neck internal rotation angles ranging from -30° to 45° with 15° intervals. Support vector machine (SVM) models and a tenfold cross-validation scheme were used to classify the subjects with and without fracture. RESULTS: High accuracy was achieved when using only FE analysis for classifying the women with and without fracture both when the fracture types were pooled (82.9 %) and when analyzed separately by femoral neck fracture (87.5 %) and trochanteric fracture (80.0 %). The accuracy was further increased when FE analysis was combined with volumetric BMD (pooled fractures accuracy, 91.4 %) CONCLUSIONS: While larger prospective studies are needed, these results demonstrate that FE analysis using multiple loading configurations together with SVM models can accurately classify individuals with previous hip fracture.


Assuntos
Fraturas do Quadril/diagnóstico por imagem , Fraturas por Osteoporose/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Densidade Óssea/fisiologia , Estudos de Casos e Controles , Feminino , Fraturas do Colo Femoral/diagnóstico por imagem , Fraturas do Colo Femoral/fisiopatologia , Análise de Elementos Finitos , Fraturas do Quadril/fisiopatologia , Humanos , Fraturas por Osteoporose/fisiopatologia , Medição de Risco/métodos , Sensibilidade e Especificidade , Máquina de Vetores de Suporte , Tomografia Computadorizada por Raios X/métodos , Suporte de Carga/fisiologia
12.
Meat Sci ; 214: 109517, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38696994

RESUMO

The objective of the study was to independently validate a calibrated commercial handheld near infrared (NIR) spectroscopic device and test its repeatability over time using phenotypically diverse populations of Australian lamb. Validation testing in eight separate data sub-groups (n = 1591 carcasses overall) demonstrated that the NIR device had moderate precision (R2 = 0.4-0.64, RMSEP = 0.70-1.22%) but fluctuated in accuracy between experimental site demonstrated by variable slopes (0.50-0.94) and biases (-0.86-0.02). The repeatability experiment (n = 10 carcasses) showed that time to scan post quartering affected NIR measurement from 0 to 24 h (P < 0.001). On average, NIR IMF% was 0.97% lower (P < 0.001) at 24 h (4.01% ± 0.166), compared to 0 h. There was no difference (P > 0.05) between Time 0 and 1 h or Time 0 and 4 h or between replicate scans within each time point. This study demonstrated the SOMA NIR device could predict lamb chemical IMF% with moderate precision and accuracy, however additional work is required to understand how loin preparation, blooming and surface hydration affect NIR measurement.


Assuntos
Músculo Esquelético , Carne Vermelha , Carneiro Doméstico , Espectroscopia de Luz Próxima ao Infravermelho , Animais , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Espectroscopia de Luz Próxima ao Infravermelho/instrumentação , Carne Vermelha/análise , Austrália , Músculo Esquelético/química , Reprodutibilidade dos Testes , Tecido Adiposo
13.
Osteoporos Int ; 24(5): 1733-40, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23179565

RESUMO

UNLABELLED: High-resolution peripheral quantitative computed tomography (HR-pQCT) measurements of distal radius and tibia bone microarchitecture and finite element (FE) estimates of bone strength performed well at classifying postmenopausal women with and without previous fracture. The HR-pQCT measurements outperformed dual energy x-ray absorptiometry (DXA) at classifying forearm fractures and fractures at other skeletal sites. INTRODUCTION: Areal bone mineral density (aBMD) is the primary measurement used to assess osteoporosis and fracture risk; however, it does not take into account bone microarchitecture, which also contributes to bone strength. Thus, our objective was to determine if bone microarchitecture measured with HR-pQCT and FE estimates of bone strength could classify women with and without low-trauma fractures. METHODS: We used HR-pQCT to assess bone microarchitecture at the distal radius and tibia in 44 postmenopausal women with a history of low-trauma fracture and 88 age-matched controls from the Calgary cohort of the Canadian Multicentre Osteoporosis Study (CaMos) study. We estimated bone strength using FE analysis and simulated distal radius aBMD from the HR-pQCT scans. Femoral neck (FN) and lumbar spine (LS) aBMD were measured with DXA. We used support vector machines (SVM) and a tenfold cross-validation to classify the fracture cases and controls and to determine accuracy. RESULTS: The combination of HR-pQCT measures of microarchitecture and FE estimates of bone strength had the highest area under the receiver operating characteristic (ROC) curve of 0.82 when classifying forearm fractures compared to an area under the curve (AUC) of 0.71 from DXA-derived aBMD of the forearm and 0.63 from FN and spine DXA. For all fracture types, FE estimates of bone strength at the forearm alone resulted in an AUC of 0.69. CONCLUSION: Models based on HR-pQCT measurements of bone microarchitecture and estimates of bone strength performed better than DXA-derived aBMD at classifying women with and without prior fracture. In future, these models may improve prediction of individuals at risk of low-trauma fracture.


Assuntos
Fraturas por Osteoporose/diagnóstico , Rádio (Anatomia)/patologia , Tíbia/patologia , Absorciometria de Fóton/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Densidade Óssea/fisiologia , Estudos de Casos e Controles , Feminino , Colo do Fêmur/fisiopatologia , Análise de Elementos Finitos , Traumatismos do Antebraço/diagnóstico por imagem , Traumatismos do Antebraço/fisiopatologia , Humanos , Vértebras Lombares/fisiopatologia , Pessoa de Meia-Idade , Fraturas por Osteoporose/diagnóstico por imagem , Fraturas por Osteoporose/fisiopatologia , Estudos Prospectivos , Rádio (Anatomia)/diagnóstico por imagem , Rádio (Anatomia)/fisiopatologia , Medição de Risco/métodos , Tíbia/diagnóstico por imagem , Tíbia/fisiopatologia , Tomografia Computadorizada por Raios X/métodos , Adulto Jovem
14.
Nat Genet ; 16(1): 44-53, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9140394

RESUMO

Huntington disease (HD) is associated with the expansion of a polyglutamine tract, greater than 35 repeats, in the HD gene product, huntingtin. Here we describe a novel huntingtin interacting protein, HIP1, which co-localizes with huntingtin and shares sequence homology and biochemical characteristics with Sla2p, a protein essential for function of the cytoskeleton in Saccharomyces cerevisiae. The huntingtin-HIP1 interaction is restricted to the brain and is inversely correlated to the polyglutamine length in huntingtin. This provides the first molecular link between huntingtin and the neuronal cytoskeleton and suggests that, in HD, loss of normal huntingtin-HIP1 interaction may contribute to a defect in membrane-cytoskeletal integrity in the brain.


Assuntos
Encéfalo/fisiologia , Proteínas de Transporte/genética , Proteínas de Ligação a DNA/genética , Proteínas Fúngicas/genética , Proteínas do Tecido Nervoso/metabolismo , Proteínas Nucleares/metabolismo , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Sequência de Aminoácidos , Animais , Western Blotting , Encéfalo/citologia , Caenorhabditis elegans/química , Caenorhabditis elegans/genética , Proteínas de Transporte/metabolismo , Sistema Nervoso Central/metabolismo , Mapeamento Cromossômico , Cromossomos Humanos Par 7 , Clonagem Molecular , Proteínas do Citoesqueleto , Proteínas de Ligação a DNA/imunologia , Proteínas de Ligação a DNA/metabolismo , Feminino , Proteínas de Helminto/genética , Humanos , Proteína Huntingtina , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/imunologia , Proteínas Nucleares/genética , Proteínas Nucleares/imunologia , Peptídeos/química , Peptídeos/metabolismo , Testes de Precipitina , Coelhos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Homologia de Sequência de Aminoácidos , Relação Estrutura-Atividade , Frações Subcelulares , Distribuição Tecidual
15.
J Dairy Sci ; 95(5): 2248-60, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22541454

RESUMO

To establish cheese as a dairy product with health benefits, we embarked on examining the multifunctional role of cheeses, especially in the field of cancer prevention. The current study was designed to investigate whether different types of commercial goat cheeses may possess antiproliferative activity, using an HL-60 human promyelocytic leukemia cell line as a cancer cell model. Among 11 cheese extracts tested at 500µg/mL, 6 (Crottin de Chavignol, Pouligny Saint-Pierre, Chabichou du Poitou, Valencay, Kavli, and Sainte-Maure de Touraine) resulted in a significant decrease of cell viability, which is consistent with a decrease in viable cell number. Compared with the half-maximal inhibitory concentration (IC(50)) value of individual cheeses in cellular proliferation assays, the Pouligny Saint-Pierre extract showed strong inhibition. Incubation of cells in the presence of Pouligny Saint-Pierre extract resulted in induction of cellular morphological changes and apoptotic DNA fragmentation as well as expression of the active form of caspase-3 protein. Based on the quantification of the ratio of free fatty acids to triglycerides in different cheese samples, a significant correlation was detected between lipolytic ripeness and IC(50) values for antiproliferative capacity tested in HL-60 cells. Collectively, these results support a potential role of highly lipolyzed goat cheeses in the prevention of leukemic cell proliferation.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Queijo , Dano ao DNA/efeitos dos fármacos , Células HL-60/efeitos dos fármacos , Animais , Western Blotting , Núcleo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Queijo/análise , Ácidos Graxos não Esterificados/análise , Cabras , Humanos , Leucemia/prevenção & controle , Lipólise , Triglicerídeos/análise
16.
Br J Cancer ; 104(5): 808-18, 2011 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-21304530

RESUMO

BACKGROUND: On the base of the microRNA (miRNA) expression signature of bladder cancer (BC), we found that miR-1 and miR-133a were significantly downregulated in BC. In this study, we focussed on the functional significance of miR-1 and miR-133a in BC cell lines and identified a molecular network of these miRNAs. METHODS AND RESULTS: We investigated the miRNA expression signature of BC clinical specimens and identified several downregulated miRNAs (miR-133a, miR-204, miR-1, miR-139-5p, and miR-370). MiR-1 and miR-133a showed potential role of tumour suppressors by functional analyses of BC cells such as cell proliferation, apoptosis, migration, and invasion assays. Molecular target searches of these miRNAs showed that transgelin 2 (TAGLN2) was directly regulated by both miR-1 and miR-133a. Silencing of TAGLN2 study demonstrated significant inhibitions of cell proliferation and increase of apoptosis in BC cell lines. The immunohistochemistry showed a positive correlation between TAGLN2 expression and tumour grade in clinical BC specimens. CONCLUSIONS: The downregulation of miR-1 and miR-133a was a frequent event in BC, and these miRNAs were recognised as tumour suppressive. TAGLN2 may be a target of both miRNAs and had a potential oncogenic function. Therefore, novel molecular networks provided by miRNAs may provide new insights into the underlying molecular mechanisms of BC.


Assuntos
MicroRNAs/farmacologia , Proteínas dos Microfilamentos/genética , Proteínas Musculares/genética , Neoplasias da Bexiga Urinária/genética , Apoptose , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Regulação para Baixo , Humanos , Transfecção
17.
Br J Cancer ; 104(2): 376-86, 2011 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-21063397

RESUMO

BACKGROUND: The aim of this study is to find a novel molecular target based on chromosomal alteration and array-based gene expression analyses in bladder cancer (BC). We investigated a cancer testis antigen, LY6K, which is located on chromosome 8q24.3. METHODS: Five BC cell lines were subjected to high-resolution array-comparative genomic hybridisation with 244 000 probes. The expression levels of LY6K mRNA were evaluated in BC cell lines and clinical BC specimens by real-time reverse transcription-PCR. The cell lines were subjected to fluorescence in situ hybridisation of LY6K. Cell viability was evaluated by cell growth, wound healing, and matrigel invasion assays. RESULTS: Typical gained loci (P<0.0001) at 6p21.33-p21.32, 8q24.3, 9q34.13, 11q13.1-q14.1, 12q13.12-q13.13, 16p13.3, and 20q11.21-q13.33 were observed in all of the cell lines. We focused on 8q24.3 locus where LY6K gene harbours, and it was the top upregulated one in the gene profile from the BC cell line. LY6K mRNA expression was significantly higher in 91 BCs than in 37 normal bladder epitheliums (P<0.0001). Fluorescence in situ hybridisation validated that the high LY6K mRNA expression was due to gene amplification in the region where the gene harbours. Cell viability assays demonstrated that significant inhibitions of cell growth, migration, and invasion occured in LY6K knock down BC cell lines; converse phenomena were observed in a stable LY6K transfectant; and LY6K knockdown of the transfectant retrieved the original phenotype from the LY6K transfectant. CONCLUSION: Upregulation of the oncogenic LY6K gene located on the gained locus at 8q24.3 may contribute BC development.


Assuntos
Antígenos Ly/genética , Genoma Humano , Neoplasias da Bexiga Urinária/genética , Mapeamento Cromossômico , Proteínas Ligadas por GPI/genética , Técnicas de Silenciamento de Genes , Humanos , Hibridização in Situ Fluorescente , Invasividade Neoplásica , Metástase Neoplásica , RNA Mensageiro/genética , RNA Interferente Pequeno , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Neoplasias da Bexiga Urinária/patologia
18.
Clin Genet ; 80(5): 484-8, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21062273

RESUMO

Ohtahara syndrome (OS) is one of the most severe and earliest forms of epilepsy. We have recently identified that the de novo mutations of STXBP1 are important causes for OS. Here we report a paternal somatic mosaicism of an STXBP1 mutation. The affected daughter had onset of spasms at 1 month of age, and interictal electroencephalogram showed suppression-burst pattern, leading to the diagnosis of OS. She had a heterozygous c.902+5G>A mutation of STXBP1, which affects donor splicing of exon 10, resulting in 138-bp insertion of intron 10 sequences in the transcript. The mutant transcript had a premature stop codon, and was degraded by nonsense-mediated mRNA decay in lymphoblastoid cells derived from the patient. High-resolution melting analysis of clinically unaffected parental DNAs suggested that the father was somatic mosaic for the mutation, which was also suggested by sequencing. Cloning of PCR products amplified with the paternal DNA samples extracted from blood, saliva, buccal cells, and nails suggested that 5.3%, 8.7%, 11.9%, and 16.9% of alleles harbored the mutation, respectively. This is a first report of somatic mosaicism of an STXBP1 mutation, which has implications in genetic counseling of OS.


Assuntos
Epilepsia/genética , Mosaicismo , Proteínas Munc18/genética , Espasmos Infantis/genética , Pai , Feminino , Humanos , Lactente , Recém-Nascido , Masculino
19.
Br J Surg ; 98(11): 1561-5, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22059233

RESUMO

BACKGROUND: Adjuvant trastuzumab for small, node-negative, human epidermal growth factor receptor 2 (HER2)-positive breast cancer remains controversial. The purpose of this study was to investigate the risk of recurrence in women with pathological tumour node (pTN) T1 N0 tumours. METHODS: Patients with pT1 N0 breast cancer diagnosed at the National Kyushu Cancer Centre between 2001 and 2007 were reviewed. Patients were categorized according to HER2 status. RESULTS: Four hundred and fifty-four patients who had pT1 N0 tumours, and had not received adjuvant trastuzumab, were identified. The HER2-negative and -positive groups comprised 376 and 78 patients (17·2 per cent) respectively. At a median follow-up of 46·3 months, there were 18 recurrences.The 5-year relapse-free survival (RFS) rates were 97·2 and 88 per cent in the HER2-negative and -positive groups respectively (P < 0·001). Multivariable analysis identified HER2-positive tumour as an independent predictor of RFS in patients with pT1 N0 tumours (hazard ratio 6·65, 95 per cent confidence interval 2·53 to 17·49; P < 0·001). CONCLUSION: Women with pT1 N0 HER2-positive breast cancer have a high risk of recurrence.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Carcinoma Ductal de Mama/tratamento farmacológico , Recidiva Local de Neoplasia/etiologia , Receptor ErbB-2/metabolismo , Idoso , Neoplasias da Mama/etiologia , Neoplasias da Mama/metabolismo , Carcinoma Ductal de Mama/etiologia , Carcinoma Ductal de Mama/metabolismo , Quimioterapia Adjuvante , Intervalo Livre de Doença , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/metabolismo , Estudos Retrospectivos , Fatores de Risco , Trastuzumab
20.
Osteoporos Int ; 22(1): 357-62, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20458576

RESUMO

UNLABELLED: We used high-resolution peripheral quantitative computed tomography (HR-pQCT) to monitor changes in bone microarchitecture and strength at the distal radius and tibia associated with 18 months of teriparatide therapy in postmenopausal women with osteoporosis. Despite treatment-associated declines in total and cortical BMD, trabecular thinning and reduced trabecular bone volume, bone strength did not change significantly from baseline. INTRODUCTION: Teriparatide is an established anabolic therapy for osteoporosis; however, treatment effects at the distal radius are unclear. Therefore, we aimed to monitor changes in bone microarchitecture and estimated strength at the distal radius and tibia in osteoporotic postmenopausal women. METHODS: We used high-resolution peripheral quantitative computed tomography (Scanco Medical, Switzerland) to perform a standard three-dimensional morphological analysis of the distal radius and tibia in 11 osteoporotic postmenopausal women (mean age, 68.7 ± 12.7 years) at baseline, 6, 12, and 18 months after initiation of 20 µg/day of teriparatide. Ten of the women received bisphosphonate therapy prior to starting on teriparatide. In addition to the standard analysis, we quantified cortical bone mineral density (BMD), porosity, and thickness using an automated segmentation procedure and estimated bone strength (ultimate stress) using finite element analysis. RESULTS: After 18 months, we observed a decrease in total BMD (p = 0.03) at the distal radius and a decrease in cortical BMD at the distal radius (p = 0.05) and tibia (p = 0.01). The declines in cortical BMD were associated with trends for increased cortical porosity at both sites. At the distal radius, 18 months of teriparatide treatment was also associated with trabecular thinning (p = 0.009) and reduced trabecular bone volume ratio (p = 0.08). We observed similar trends at the distal tibia. Despite these changes in bone quality, bone strength was maintained over the 18-month follow-up. CONCLUSIONS: The observed changes in cortical bone structure are consistent with the effects of parathyroid hormone on intracortical bone remodeling. Controlled trials involving larger sample sizes are required to confirm the effects of teriparatide therapy on trabecular and cortical microarchitecture in the peripheral skeleton.


Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Osteoporose Pós-Menopausa/tratamento farmacológico , Teriparatida/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Densidade Óssea/efeitos dos fármacos , Conservadores da Densidade Óssea/administração & dosagem , Esquema de Medicação , Monitoramento de Medicamentos/métodos , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/patologia , Osteoporose Pós-Menopausa/fisiopatologia , Rádio (Anatomia)/efeitos dos fármacos , Rádio (Anatomia)/patologia , Rádio (Anatomia)/fisiopatologia , Estresse Mecânico , Teriparatida/administração & dosagem , Tíbia/efeitos dos fármacos , Tíbia/patologia , Tíbia/fisiopatologia , Tomografia Computadorizada por Raios X/métodos
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