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1.
Dev Psychol ; 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38913756

RESUMO

A parent-directed intervention designed to foster growth-oriented mindsets about math was evaluated in a longitudinal randomized-control trial. Parents (N = 615; 61% White, 22% Black; 63% with at least a bachelor's degree) participated in the intervention or an active control condition in which they learned about the Common Core math curriculum. Parents reported on their math mindsets and parenting practices (e.g., autonomy-supportive math homework assistance) over 15-18 months; their young elementary school children's (Mage = 7.17 years; 50% girls) math adjustment (e.g., mindsets and achievement) was also assessed. The intervention (vs. control) led to sustained increases in parents' beliefs that math ability is malleable and math failure is beneficial for learning. The intervention, however, did not improve their math parenting practices or children's math adjustment relative to the control. Instead, there were generally improvements in math parenting practices and children's math adjustment over the course of the study regardless of condition, perhaps because the control condition provided parents with useful information about the Common Core math curriculum. Overall, the findings indicate that although the mindset intervention was effective in instilling stronger growth-oriented mindsets about math in parents, this did not translate into benefits for children's math learning over and above the active control condition. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

2.
Med Phys ; 50(7): 4459-4465, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37060293

RESUMO

BACKGROUND: High precision radiotherapy with small irradiator size has potential in many treatment applications involving small shallow targets, with small animal radio-neuromodulation as an intriguing example. A focused kV technique based on novel usage of polycapillary x-ray lenses can focus x-ray beams to <0.2 mm in diameter, which is ideal for such uses. PURPOSE: Such an application also requires high resolution CT images for treatment planning and setup. In this work, we demonstrate the feasibility of using a virtual focal spot generated with an x-ray lens to perform high-resolution CBCT acquisition. METHOD: The experiment with x-ray lens was set up on an x-ray tabletop system to generate a virtual focal spot. The flood field images with and without the x-ray lens were first compared. A pinhole image was acquired for the virtual focal spot and compared with the one acquired with the conventional focal spot without the lens. The planar imaging resolution with and without the lens were evaluated using a line pair resolution phantom. The spatial resolution of the two settings were estimated by reconstructing a 0.15-mm wire phantom and comparing its full width half maximum (FWHM). A CBCT scan of a rodent head was also acquired to further demonstrate the improved resolution using the x-ray lens. RESULT: The proposed imaging setup with x-ray lens had a limited exposure area of 5 cm by 5 cm on the detector, which was suitable for guiding radio-neuromodulation to a small target in rodent brain. Compared to conventional imaging acquisition with a measured x-ray focal spot of 0.395 mm FWHM, the virtual focal spot size was measured at 0.175 mm. The reduction in focal spot size with lens leads to an almost doubled planar imaging resolution and a 26% enhancement in 3D spatial resolution. A realistic CBCT acquisition of a rodent head mimicked the imaging acquisition step for radio-neuromodulation and further showed the improved visualization for fine structures. CONCLUSION: This work demonstrated that the focused kV x-ray technique was capable of generating small focal spot size of <0.2 mm, which substantially improved x-ray imaging resolution for small animal imaging.


Assuntos
Cabeça , Animais , Raios X , Radiografia , Imagens de Fantasmas , Cabeça/diagnóstico por imagem
3.
Biomed Phys Eng Express ; 8(5)2022 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-35623335

RESUMO

X-ray phase-contrast imaging can display subtle differences in low-density materials (e.g. soft tissues) more readily than conventional x-ray imaging. However, producing x-ray phase images requires significant spatial coherence of the beam which in turn requires highly specialized sources such as synchrotrons, small and low power microfocus sources, or complex procedures, such as multiple exposures with several carefully stepped precision gratings. To find appropriate approaches for producing x-ray phase-contrast imaging in a clinically meaningful way, we employed a grating-free method that utilized a low-cost, coarse wire mesh and simple processing. This method relaxes the spatial coherence constraint and allows quantitative phase retrieval for not only monochromatic but also polychromatic beams. We also combined the mesh-based system with polycapillary optics to significantly improve the accuracy of quantitative phase retrieval.


Assuntos
Óptica e Fotônica , Síncrotrons , Radiografia , Raios X
4.
Med Phys ; 48(11): 6642-6657, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34554583

RESUMO

PURPOSE: X-ray phase and dark-field (DF) imaging have been shown to improve the diagnostic capabilities of X-ray systems. However, these methods have found limited clinical use due to the need for multiple precision gratings with limited field of view or requirements on X-ray coherence that may not be easily translated to clinical practice. This work aims to develop a practicable X-ray phase and DF imaging system that could be translated and practiced in the clinic. METHODS: This work employs a conventional source to create structured illumination with a simple wire mesh. A mesh-shifting algorithm is used to allow wider Fourier windowing to enhance resolution. Deconvolution of the source spot width and camera resolution improves accuracy. Polycapillary optics are employed to enhance coherence. The effects of incorporating optics with two different focal lengths are compared. Information apparent in enhanced absorption images, phase images, and DF images of fat embedded phantoms were compared and subjected to a limited receiver operator characteristic (ROC) study. The DF images of the moist and dry porous object (sponges) were compared. RESULTS: The mesh-based phase and DF imaging system constructs images with three different information types: scatter-free absorption images, differential phase images, and scatter magnitude/DF images, simultaneously from the same original image. The polycapillary optic enhances the coherence of the beam. The deblurring technique corrects the phase signal error due to geometrical blur and the limitation of the camera modulation transfer function (MTF) and removes image artifacts to improve the resolution in a single shot. The mesh-shifting method allows the use of a wider Fourier processing window, which gives even higher resolution, at the expense of an increased dose. The limited ROC study confirms the efficacy of the system over the conventional system. DF images of moist and dry porous object show the significance of the system in the imaging of lung infections. CONCLUSION: The mesh-based X-ray phase and DF imaging system is an inexpensive and easy setup in terms of alignment and data acquisition and can produce phase and DF images in a single shot with wide field of view. The system shows significant potential for use in diagnostic imaging in a clinical setting.


Assuntos
Algoritmos , Iluminação , Processamento de Imagem Assistida por Computador , Imagens de Fantasmas , Radiografia , Raios X
5.
Public Health Nutr ; 13(5): 720-9, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-19889246

RESUMO

OBJECTIVE: To assess the impact of the 1996-2005 integrated community-based micronutrient and health (MICAH) programme on linear growth retardation (stunting) in Malawian preschool children living in rural areas. DESIGN: Prospective study of three large-scale cross-sectional surveys conducted in 1996, 2000 and 2004 in MICAH and Comparison populations. SETTING: Rural areas in Malawi. SUBJECTS: Preschool children (6.0-59.9 months) from randomly selected households (474 from the 1996 baseline survey; 1264 from 2000 MICAH areas; 1500 from 2000 Comparison areas; 1959 from 2004 MICAH areas; and 1008 from 2004 Comparison areas), who responded to a household questionnaire, were weighed and measured using standard protocols. RESULTS: At the baseline in 1996, the prevalence of stunting (60.2 %) was very high. By 2000, the prevalence of stunting had declined to 50.6 % and 56.0 % (chi2 = 7.8, P = 0.005) in MICAH and Comparison areas, respectively. In 2004, the prevalence of stunting did not differ significantly between MICAH and Comparison areas (43.0 % v. 45.1 %; chi2 = 1.11, P = 0.3). Severe stunting affected 34.7 % of children at baseline, which declined to 15.8 % and 17.1 % (chi2 = 0.86, P = 0.4) in MICAH and Comparison areas, respectively, by 2004. Regional variations existed, with proportionately fewer children from the Northern region being stunted compared to their Central and Southern region counterparts. CONCLUSION: Given the length of implementation, wide-scale coverage and positive impact on child growth in Phase I (1996-2000), the MICAH programme is a potential model for combating linear growth retardation in rural areas in Malawi, although the catch-up improvement in Comparison areas during Phase II (2000-2004) cannot be adequately explained.


Assuntos
Transtornos da Nutrição Infantil/epidemiologia , Transtornos do Crescimento/epidemiologia , Micronutrientes/administração & dosagem , População Rural/estatística & dados numéricos , Estatura/fisiologia , Transtornos da Nutrição Infantil/etiologia , Transtornos da Nutrição Infantil/prevenção & controle , Pré-Escolar , Estudos Transversais , Feminino , Transtornos do Crescimento/etiologia , Transtornos do Crescimento/prevenção & controle , Promoção da Saúde , Humanos , Lactente , Malaui/epidemiologia , Masculino , Prevalência , Avaliação de Programas e Projetos de Saúde , Estudos Prospectivos , Fatores de Risco , Saúde da População Rural
6.
Public Health Nutr ; 13(9): 1445-52, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19889247

RESUMO

OBJECTIVE: To assess the impact of an integrated community-based micronutrient and health (MICAH) programme on anaemia (Hb < 120 g/l) among non-pregnant rural Malawian women aged 15-49 years from communities that participated in the 1996-2005 MICAH programme. DESIGN: Prospective study of two large-scale cross-sectional surveys conducted in 2000 and 2004 as part of programme evaluation in MICAH and Comparison areas. SETTING: Rural areas across Malawi. The MICAH programme implemented a comprehensive package of interventions to reduce anaemia, based on a broad range on direct and indirect causes in Malawi. The project approaches included: Fe supplementation; dietary diversification and modification; food fortification; and strengthening primary health care. PARTICIPANTS: Non-pregnant women of childbearing age (15-49 years old, n 5422), from randomly selected households that responded to a household questionnaire, had their Hb measured from finger-prick blood samples using the HemoCue. RESULTS: In 2000, there was no significant difference in Hb concentration between MICAH and Comparison areas (mean (SE): 117.4 (0.4) v. 116.8 (0.5) g/l, P > 0.05) and the corresponding prevalence of anaemia (53.5 % v. 52.9 %, P > 0.05). By 2004, Hb concentration had increased significantly in MICAH but not in Comparison areas (mean (SE): 121.0 (0.4) v. 115.7 (0.6) g/l, P < 0.001), and the prevalence of anaemia had declined significantly in MICAH areas (53.5 % to 44.1 %, chi2 = 28.2, P < 0.0001) but not in Comparison areas (52.8 % to 54.0 %, chi2 = 0.3, P = 0.6). CONCLUSIONS: The MICAH programme was an effective public health nutrition programme that was associated with significant reductions in the prevalence of anaemia among non-pregnant rural Malawian women.


Assuntos
Anemia/sangue , Anemia/epidemiologia , Hemoglobinas/análise , Ferro da Dieta/administração & dosagem , Avaliação de Programas e Projetos de Saúde , Saúde Pública , Adolescente , Adulto , Serviços de Saúde Comunitária , Estudos Transversais , Suplementos Nutricionais , Feminino , Alimentos Fortificados , Humanos , Malaui/epidemiologia , Pessoa de Meia-Idade , Prevalência , Estudos Prospectivos , População Rural/estatística & dados numéricos , Adulto Jovem
7.
Curr Dev Nutr ; 4(1): nzz141, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31893262

RESUMO

BACKGROUND: Global recommendations on optimal maternal and child nutrition (MCN) practices are clear; however, there is limited literature 1) exploring how roles of family members influence those practices and on 2) designing programs accordingly. Researchers using a family-systems approach in the Global South find that grandmothers often play a vital role in MCN, yet most nutrition programs narrowly target mothers, thereby potentially limiting effectiveness. OBJECTIVES: This article reports on the results of qualitative research exploring the roles and influence of family members on MCN in southern Sierra Leone, the local MCN beliefs and practices, and how those findings informed the design of a culturally appropriate program. METHODS: Focus group discussions (FGDs) were conducted with mothers, fathers, and grandmothers in 9 communities in Bonthe District, Sierra Leone. We used participatory tools to explore family members' roles and local MCN beliefs and practices. Interviews were recorded by notetakers and coded and analyzed using a content analysis approach. RESULTS: A total of 88 mothers, 125 grandmothers, and 79 fathers participated in the FGDs. All groups indicated that 1) grandmothers are the culturally designated advisors and supervisors of women on MCN issues and 2) mothers are not autonomous decision makers and are greatly influenced by grandmothers. The research identified both beneficial MCN practices and gaps between optimal and existing MCN practices-particularly related to maternal diet during pregnancy and exclusive breastfeeding for 6 mo. Research findings were used to design a grandmother-inclusive program. CONCLUSIONS: Our research showed that mothers are embedded in a family system of caring and supervision where grandmothers have primary influence on MCN practices, clearly supporting the need for grandmothers to have a central role in community MCN programs. It also points to the need for increased use of a family-systems approach in designing public health nutrition programs.

8.
Med Phys ; 47(10): 5123-5134, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32683708

RESUMO

PURPOSE: Wet (neovascular) age-related macular degeneration (AMD) is the leading cause of blindness in the United States. The mainstay treatment requires monthly intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) drugs, associated with multiple visits, high cost, and the risk of procedural injury and infection. Anti-VEGF drugs inhibit the formation of neovasculature but do not directly attack it. Radiotherapy can destroy neovasculature and potentially also inhibit wet-AMD associated inflammation and fibrosis not addressed by VEGF inhibitors. However, the current collimation-based radiotherapy device uses fixed 4 mm beams, which are prone to overtreat or undertreat the choroidal neovascularization (CNV) lesions because of their various sizes and shapes. This simulation study evaluates personalized conformal treatment with focused kV radiation using cutting-edge polycapillary x-ray optics. METHODS: Simulation of the polycapillary optics was achieved via Monte Carlo (MC)-based three-dimensional (3D) geometric ray tracing. Phase-space files modeling the focused photons were generated. The method was previously verified by phantom measurements. The ultrasmall ~0.2 mm beam focal spot perpendicular to the beam direction enables spatially fractionated grid therapy, which has been shown to preferentially damage abnormal neovascular blood vessels vs normal ones. Geant4-based MC simulations of scanning while rotating beam delivery were performed to conformally treat three clinical cases of large, medium, and small CNV lesions with regular and grid deliveries. Dose delivery uncertainties due to positioning errors were analyzed, including ±0.75 mm displacement in the three orthogonal directions and ±5° vertical/horizontal rotation of the eyeball. RESULTS: The simulated CNV treatments by 60-kVp focused x-ray beams show highly conformal delivery of dose to the lesion plus margin (0.75 mm) with sharp dose fall-offs and controllable spatial modulation patterns. The 90%-10% isodose penumbra is <0.5 mm. With a prescription dose of 16 Gy to the lesions, the critical structure doses are well below the tolerance. The average CNV dose varies within 10% (mostly within 4%) due to 0.75-mm linear displacements and 5-degree gaze angle rotation of the eyeball. CONCLUSION: Focused kV technique allows personalized treatment of CNV lesions and reduces unwanted radiation to adjacent healthy tissue. The simulated dose distribution is superior to currently available techniques.


Assuntos
Degeneração Macular , Radiometria , Humanos , Método de Monte Carlo , Dosagem Radioterapêutica , Raios X
9.
Curr Dev Nutr ; 4(12): nzaa174, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33409444

RESUMO

BACKGROUND: Suboptimal infant and young child feeding (IYCF) practices contribute to child undernutrition. Sierra Leone Demographic and Health Survey data show that IYCF practices remain poor despite modest improvements. Recent studies have identified the role of grandmothers as critical to child nutrition; however, in Sierra Leone to date, the potential for grandmothers to influence IYCF practices has not been investigated. OBJECTIVES: We examined how an innovative grandmother-inclusive approach (GMIA) can be used to address suboptimal IYCF practices. METHODS: Using a quasi-experimental design, we compared IYCF beliefs and practices between GMIA intervention communities (receiving monthly dialogue sessions on nutrition, quarterly community praise sessions, and intergenerational forums) and comparison communities (receiving standard nutrition education) in Bum chiefdom from 2013 and 2016. The quantitative endline survey targeted 101 pregnant women, 291 women with children aged <2 y, and 219 grandmothers. Statistical analyses utilized t tests and χ2 tests to examine differences between intervention and comparison communities at endline. Multivariate regression was used to determine the intervention's effect on IYCF outcomes of interest. RESULTS: Awareness of and participation in the GMIA was high among mothers and grandmothers in intervention communities. The percentage of infants and young children aged 0-23 mo (n = 291) exclusively breastfed during the first week of life was significantly higher in the intervention group (90.2% compared with 79.4%, P = 0.01). Among infants aged 6-23 mo (n = 219), the percentage achieving minimum dietary diversity and minimum acceptable diet was significantly higher in the intervention group (77.2% compared with 51.8%, P < 0.001; and 53.8% compared with 22.6%, P < 0.001, respectively). Differences in percentages achieving minimum meal frequency (MMF) were only significant for infants aged 9-23 mo, with the intervention group achieving a higher MMF (54.6% compared with 36.9%, P = 0.02). CONCLUSIONS: Results suggest that a GMIA that recognizes grandmothers' roles and strengthens their knowledge can contribute to improved IYCF practices.

10.
Respir Physiol Neurobiol ; 260: 70-81, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30439529

RESUMO

Chronic exposure to intermittent hyperoxia causes abnormal carotid body development and attenuates the hypoxic ventilatory response (HVR) in neonatal rats. We hypothesized that concurrent exposure to intermittent hypercapnic hypoxia would influence this plasticity. Newborn rats were exposed to alternating bouts of hypercapnic hypoxia (10% O2/6% CO2) and hyperoxia (30-40% O2) (5 cycles h-1, 24 h d-1) through 13-14 days of age; the experiment was run twice, once in a background of 21% O2 and once in a background of 30% O2 (i.e., "relative hyperoxia"). Hyperoxia had only small effects on carotid body development when combined with intermittent hypercapnic hypoxia: the carotid chemoafferent response to hypoxia was reduced, but this did not affect the HVR. In contrast, sustained exposure to 30% O2 reduced carotid chemoafferent activity and carotid body size which resulted in a blunted HVR. When given alone, chronic intermittent hypercapnic hypoxia increased carotid body size and reduced the hypercapnic ventilatory response but did not affect the HVR. Overall, it appears that intermittent hypercapnic hypoxia counteracted the effects of hyperoxia on the carotid body and prevented developmental plasticity of the HVR.


Assuntos
Hipercapnia/fisiopatologia , Hiperóxia/fisiopatologia , Ventilação Pulmonar/fisiologia , Fatores Etários , Análise de Variância , Animais , Animais Recém-Nascidos , Gasometria , Corpo Carotídeo/patologia , Corpo Carotídeo/fisiopatologia , Feminino , Hemoglobinas/metabolismo , Pulmão/patologia , Masculino , Gravidez , Ratos , Ratos Sprague-Dawley , Mecânica Respiratória , Fatores de Tempo
11.
JCI Insight ; 3(5)2018 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-29515022

RESUMO

Loss-of-function mutations in genes encoding contractile proteins have been observed in thoracic aortic aneurysms (TAA). To gain insight into the contribution of contractile protein deficiency in the pathogenesis of TAA, we examined human aneurysm samples. We found multiple contractile gene products deficient in TAA samples, and in particular, expression of SM22α was inversely correlated with aneurysm size. SM22α-deficient mice demonstrated pregnancy-induced aortic dissection, and SM22α deficiency worsened aortic aneurysm in Fbn1C1039G/+ (Marfan) mice, validating this gene product as a TAA effector. We found that repression of SM22α was enforced by increased activity of the methyltransferase EZH2. TGF-ß effectors such as SMAD3 were excluded from binding SM22α-encoding chromatin (TAGLN) in TAA samples, while treatment with the EZH2 inhibitor GSK343 improved cytoskeletal architecture and restored SM22α expression. Finally, inhibition of EZH2 improved aortic performance in Fbn1C1039G/+ mice, in association with restoration of contractile protein expression (including SM22α). Together, these data inform our understanding of contractile protein deficiency in TAA and support the pursuit of chromatin modifying factors as therapeutic targets in aortic disease.


Assuntos
Aneurisma da Aorta Torácica/tratamento farmacológico , Proteína Potenciadora do Homólogo 2 de Zeste/antagonistas & inibidores , Indazóis/administração & dosagem , Músculo Liso Vascular/patologia , Piridonas/administração & dosagem , Animais , Aorta Torácica/patologia , Aorta Torácica/fisiopatologia , Aneurisma da Aorta Torácica/etiologia , Aneurisma da Aorta Torácica/patologia , Aneurisma da Aorta Torácica/fisiopatologia , Metilação de DNA/efeitos dos fármacos , Modelos Animais de Doenças , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Epigênese Genética/efeitos dos fármacos , Fibrilina-1/genética , Técnicas de Inativação de Genes , Histonas/metabolismo , Humanos , Losartan/administração & dosagem , Síndrome de Marfan/complicações , Síndrome de Marfan/genética , Camundongos , Camundongos Knockout , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/patologia , RNA Interferente Pequeno/metabolismo
12.
Med Phys ; 45(10): 4720-4733, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30133705

RESUMO

PURPOSE: Eye plaque brachytherapy is the most common approach for intraocular cancer treatment. It is, however, invasive and subject to large setup uncertainty due to the surgical operation. We propose a novel-focused kV x-ray technique with potential nanoparticle (NP) enhancement and evaluate its application in treating choroidal melanoma and iris melanoma by Monte Carlo (MC) dosimetry modeling. METHODS: A polycapillary x-ray lens was used to focus 45 kVp x rays to achieve pinpoint accuracy of dose delivery to small tumors near critical structures. In addition to allowing for beam focusing, the use of kV x rays takes advantage of the strong photoelectric absorption of metallic NPs in that energy regime and hence strong radiosensitization. We constructed an MC simulation program that takes into account the x-ray optic modeling and used GEANT4 for dosimetric calculation. Extensive phantom measurements using a prototype-focused x-ray system were carried out. The MC simulation of simple geometry phantom irradiation was first compared to measurements to verify the x-ray optic lens modeling in conjunction with the Geant4 dosimetric calculation. To simulate tumor treatment, a geometric eye model and two tumor models were constructed. Dose distributions of the simulated treatments were then calculated. NP radiosensitization was also simulated for two concentrations of 2 nm gold NP (AuNP) uniformly distributed in the tumor. RESULTS: The MC-simulated full width at half maximum (FWHM) and central-axis depth dose of the focused kV x-ray beam match those measured on EBT3 films within ~10% around the depth of focus of the beam. Dose distributions of the simulated ocular tumor treatments show that focused x-ray beams can concentrate the high-dose region in or close to the tumor plus margin. For the simulated posterior choroidal tumor treatment, with sufficient tumor coverage, the doses to the optic disc and fovea are substantially reduced with focused x-ray therapy compared to eye plaque treatment (3.8 vs 39.8 Gy and 11.1 vs 53.8 Gy, respectively). The eye plaque treatment was calculated using an Eye Physics plaque with I-125 seeds under TG43 assumption. For the energy spectrum used in this study, the average simulated dose enhancement ratios (DERs) are roughly 2.1 and 1.1 for 1.0% and 0.1% AuNP mass concentration in the tumor, respectively. CONCLUSION: Compared to eye plaque brachytherapy, the proposed focused kV x-ray technique is noninvasive and shows great advantage in sparing healthy critical organs without sacrificing the tumor control. The NP radiation dose enhancement is considerable at our proposed kV range even with a low NP concentration in the tumor, providing better critical structure protection and more flexibility for treatment planning.


Assuntos
Braquiterapia , Oftalmopatias/radioterapia , Modelos Biológicos , Método de Monte Carlo , Nanopartículas , Doses de Radiação , Radiossensibilizantes/farmacologia , Braquiterapia/instrumentação , Radiometria , Dosagem Radioterapêutica
13.
Circ Genom Precis Med ; 11(4): e001933, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29650765

RESUMO

BACKGROUND: Previous studies describing genetics evaluation in spontaneous coronary artery dissection (SCAD) have been retrospective in nature or presented as single case reports. As part of a dedicated clinical program, we evaluated patients in cardiovascular genetics clinic to determine the role of genetically triggered vascular disease and genetic testing in SCAD. METHODS AND RESULTS: Patient data were entered prospectively into the Massachusetts General Hospital SCAD registry database from July 2013 to September 2017. Clinically indicated genetic testing was conducted based on patient imaging, family history, physical examination, and patient preference. Of the 107 patients enrolled in the registry, 73 underwent cardiovascular genetics evaluation at our center (average age, 45.3±9.4 years; 85.3% female), and genetic testing was performed for 44 patients. A family history of aneurysm or dissection was not a prevalent feature in the study population, and only 1 patient had a family history of SCAD. Six patients (8.2%) had identifiable genetically triggered vascular disease: 3 with vascular Ehlers-Danlos syndrome (COL3A1), 1 with Nail-patella syndrome (LMX1B), 1 with autosomal dominant polycystic kidney disease (PKD1), and 1 with Loeys-Dietz syndrome (SMAD3). None of these 6 had radiographic evidence of fibromuscular dysplasia. CONCLUSIONS: In this series, 8.2% of the SCAD patients evaluated had a molecularly identifiable disorder associated with vascular disease. The most common diagnosis was vascular Ehlers-Danlos syndrome. Patients with positive gene testing were significantly younger at the time of their first SCAD event. A low threshold for genetic testing should be considered in patients with SCAD.


Assuntos
Anomalias dos Vasos Coronários/genética , Análise Mutacional de DNA/métodos , Testes Genéticos/métodos , Mutação , Doenças Vasculares/congênito , Adulto , Boston , Anomalias dos Vasos Coronários/diagnóstico por imagem , Bases de Dados Factuais , Feminino , Estudos de Associação Genética , Marcadores Genéticos , Predisposição Genética para Doença , Hereditariedade , Hospitais Gerais , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Fenótipo , Valor Preditivo dos Testes , Estudos Prospectivos , Sistema de Registros , Fatores de Risco , Centros de Atenção Terciária , Doenças Vasculares/diagnóstico por imagem , Doenças Vasculares/genética
14.
Nat Commun ; 9(1): 1009, 2018 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-29520069

RESUMO

Thoracic aortic aneurysm (TAA) has been associated with mutations affecting members of the TGF-ß signaling pathway, or components and regulators of the vascular smooth muscle cell (VSMC) actomyosin cytoskeleton. Although both clinical groups present similar phenotypes, the existence of potential common mechanisms of pathogenesis remain obscure. Here we show that mutations affecting TGF-ß signaling and VSMC cytoskeleton both lead to the formation of a ternary complex comprising the histone deacetylase HDAC9, the chromatin-remodeling enzyme BRG1, and the long noncoding RNA MALAT1. The HDAC9-MALAT1-BRG1 complex binds chromatin and represses contractile protein gene expression in association with gain of histone H3-lysine 27 trimethylation modifications. Disruption of Malat1 or Hdac9 restores contractile protein expression, improves aortic mural architecture, and inhibits experimental aneurysm growth. Thus, we highlight a shared epigenetic pathway responsible for VSMC dysfunction in both forms of TAA, with potential therapeutic implication for other known HDAC9-associated vascular diseases.


Assuntos
Aneurisma da Aorta Torácica/genética , DNA Helicases/genética , Histona Desacetilases/genética , Músculo Liso Vascular/patologia , Proteínas Nucleares/genética , RNA Longo não Codificante/genética , Proteínas Repressoras/genética , Fatores de Transcrição/genética , Fator de Crescimento Transformador beta/metabolismo , Actomiosina/genética , Actomiosina/metabolismo , Animais , Aorta/patologia , Aneurisma da Aorta Torácica/patologia , Linhagem Celular , Núcleo Celular/metabolismo , Cromatina/metabolismo , DNA Helicases/metabolismo , Metilação de DNA , Modelos Animais de Doenças , Feminino , Imunofluorescência , Histona Desacetilases/metabolismo , Histonas/metabolismo , Humanos , Masculino , Camundongos , Camundongos Knockout , Músculo Liso Vascular/citologia , Mutação , Miócitos de Músculo Liso , Proteínas Nucleares/metabolismo , Fenótipo , Cultura Primária de Células , Interferência de RNA , RNA Longo não Codificante/metabolismo , RNA Interferente Pequeno/metabolismo , Proteínas Repressoras/metabolismo , Transdução de Sinais/genética , Fatores de Transcrição/metabolismo
15.
J Med Imaging (Bellingham) ; 3(3): 033504, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27610397

RESUMO

Conventional mammography can suffer from poor contrast between healthy and cancerous tissues due to the small difference in attenuation properties. Coherent scatter slot scan imaging is an imaging technique which provides additional information and is compatible with conventional mammography. A Monte Carlo simulation of coherent scatter slot scan imaging was performed to assess its performance and provide system optimization. Coherent scatter could be exploited using a system similar to conventional slot scan mammography system with antiscatter grids tilted at the characteristic angle of cancerous tissues. System optimization was performed across several parameters, including source voltage, tilt angle, grid distances, grid ratio, and shielding geometry. The simulated carcinomas were detectable for tumors as small as 5 mm in diameter, so coherent scatter analysis using a wide-slot setup could be promising as an enhancement for screening mammography. Employing coherent scatter information simultaneously with conventional mammography could yield a conventional high spatial resolution image with additional coherent scatter information.

16.
J Med Imaging (Bellingham) ; 3(3): 030501, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27610395

RESUMO

A system using a wide-slot beam and simple antiscatter grids or slots has been designed to provide a localized map of tissue type that could be overlaid on the simultaneous conventional transmission image to provide an inexpensive, low dose adjunct to conventional screening mammography. Depth information is obtainable from the stereoscopic viewing angles. The system was demonstrated to produce observable contrast between adipose tissue and a phantom chosen to mimic carcinoma at an exposure comparable with screening mammography. Imaging data was collected over a range of system parameters to optimize contrast and to allow verification of simulation modeling.

17.
Int J Epidemiol ; 39(2): 613-29, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20202929

RESUMO

BACKGROUND: Evaluations of large-scale health and nutrition programmes in developing countries are needed for determining the effectiveness of interventions. This article critically analyses a non-governmental organization (NGO)-led large-scale, multi-country, 10-year micronutrient and health (MICAH) programme with an 'adequacy evaluation', that is, a documentation of time trends in the expected direction. METHODS: MICAH was implemented from 1996 to 2005 in selected areas of Ethiopia, Ghana, Malawi and Tanzania, reaching >6 million people with numerous health and nutrition interventions. Coverage and impact were monitored through surveys at baseline, midpoint and end of funding. The data were subjected to post-hoc methods of quality determination, and, if of suitable quality, included in the adequacy evaluation. RESULTS: Most collected data were of moderate or high quality and therefore included in the adequacy evaluation. There were moderate to large improvements in vitamin A status in Ethiopian school-age children, children <5 years of age in Tanzania and Ghana and mothers in Ghana. Iodine status improved in Malawi and Tanzania. Anaemia rates and malaria prevalence decreased in women, pregnant women and pre-school children in Ghana, Malawi and Tanzania, but anaemia increased in Ethiopian women. Large increases were reported for rates of exclusive breastfeeding and immunization. Child growth improved to the maximum that would be predicted with the given interventions. CONCLUSIONS: Numerous nutrition and health impacts were observed in the intervention areas, often of a magnitude equal to or larger than observed in controlled interventions or trials. These results show the value of integrated long-term interventions.


Assuntos
Suplementos Nutricionais , Promoção da Saúde , Indicadores Básicos de Saúde , Micronutrientes/uso terapêutico , Avaliação de Programas e Projetos de Saúde , Anemia Ferropriva/epidemiologia , Anemia Ferropriva/prevenção & controle , Pré-Escolar , Análise por Conglomerados , Etiópia , Gana , Humanos , Lactente , Iodo/deficiência , Malária/epidemiologia , Malária/prevenção & controle , Malaui , Masculino , Vacinação em Massa/estatística & dados numéricos , Prevalência , Tanzânia , Deficiência de Vitamina A/epidemiologia , Deficiência de Vitamina A/prevenção & controle
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