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1.
Sci Transl Med ; 16(749): eabp8334, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38809966

RESUMO

Fibrodysplasia ossificans progressiva (FOP) is a rare genetic disease driven by gain-of-function variants in activin receptor-like kinase 2 (ALK2), the most common variant being ALK2R206H. In FOP, ALK2 variants display increased and dysregulated signaling through the bone morphogenetic protein (BMP) pathway resulting in progressive and permanent replacement of skeletal muscle and connective tissues with heterotopic bone, ultimately leading to severe debilitation and premature death. Here, we describe the discovery of BLU-782 (IPN60130), a small-molecule ALK2R206H inhibitor developed for the treatment of FOP. A small-molecule library was screened in a biochemical ALK2 binding assay to identify potent ALK2 binding compounds. Iterative rounds of structure-guided drug design were used to optimize compounds for ALK2R206H binding, ALK2 selectivity, and other desirable pharmacokinetic properties. BLU-782 preferentially bound to ALK2R206H with high affinity, inhibiting signaling from ALK2R206H and other rare FOP variants in cells in vitro without affecting signaling of closely related homologs ALK1, ALK3, and ALK6. In vivo efficacy of BLU-782 was demonstrated using a conditional knock-in ALK2R206H mouse model, where prophylactic oral dosing reduced edema and prevented cartilage and heterotopic ossification (HO) in both muscle and bone injury models. BLU-782 treatment preserved the normal muscle-healing response in ALK2R206H mice. Delayed dosing revealed a short 2-day window after injury when BLU-782 treatment prevented HO in ALK2R206H mice, but dosing delays of 4 days or longer abrogated HO prevention. Together, these data suggest that BLU-782 may be a candidate for prevention of HO in FOP.


Assuntos
Modelos Animais de Doenças , Miosite Ossificante , Ossificação Heterotópica , Animais , Miosite Ossificante/tratamento farmacológico , Miosite Ossificante/metabolismo , Ossificação Heterotópica/tratamento farmacológico , Ossificação Heterotópica/metabolismo , Ossificação Heterotópica/prevenção & controle , Camundongos , Humanos , Receptores de Activinas Tipo II/metabolismo , Receptores de Ativinas Tipo I/metabolismo , Receptores de Ativinas Tipo I/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos
2.
mSystems ; 9(3): e0118823, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38415636

RESUMO

Members of the "Candidatus Accumulibacter" genus are widely studied as key polyphosphate-accumulating organisms (PAOs) in biological nutrient removal (BNR) facilities performing enhanced biological phosphorus removal (EBPR). This diverse lineage includes 18 "Ca. Accumulibacter" species, which have been proposed based on the phylogenetic divergence of the polyphosphate kinase 1 (ppk1) gene and genome-scale comparisons of metagenome-assembled genomes (MAGs). Phylogenetic classification based on the 16S rRNA genetic marker has been difficult to attain because most "Ca. Accumulibacter" MAGs are incomplete and often do not include the rRNA operon. Here, we investigate the "Ca. Accumulibacter" diversity in pilot-scale treatment trains performing BNR under low dissolved oxygen (DO) conditions using genome-resolved metagenomics. Using long-read sequencing, we recovered medium- and high-quality MAGs for 5 of the 18 "Ca. Accumulibacter" species, all with rRNA operons assembled, which allowed a reassessment of the 16S rRNA-based phylogeny of this genus and an analysis of phylogeny based on the 23S rRNA gene. In addition, we recovered a cluster of MAGs that based on 16S rRNA, 23S rRNA, ppk1, and genome-scale phylogenetic analyses do not belong to any of the currently recognized "Ca. Accumulibacter" species for which we propose the new species designation "Ca. Accumulibacter jenkinsii" sp. nov. Relative abundance evaluations of the genus across all pilot plant operations revealed that regardless of the operational mode, "Ca. A. necessarius" and "Ca. A. propinquus" accounted for more than 40% of the "Ca. Accumulibacter" community, whereas the newly proposed "Ca. A. jenkinsii" accounted for about 5% of the "Ca. Accumulibacter" community.IMPORTANCEOne of the main drivers of energy use and operational costs in activated sludge processes is the amount of oxygen provided to enable biological phosphorus and nitrogen removal. Wastewater treatment facilities are increasingly considering reduced aeration to decrease energy consumption, and whereas successful BNR has been demonstrated in systems with minimal aeration, an adequate understanding of the microbial communities that facilitate nutrient removal under these conditions is still lacking. In this study, we used genome-resolved metagenomics to evaluate the diversity of the "Candidatus Accumulibacter" genus in pilot-scale plants operating with minimal aeration. We identified the "Ca. Accumulibacter" species enriched under these conditions, including one novel species for which we propose "Ca. Accumulibacter jenkinsii" sp. nov. as its designation. Furthermore, the MAGs obtained for five additional "Ca. Accumulibacter" species further refine the phylogeny of the "Ca. Accumulibacter" genus and provide new insight into its diversity within unconventional biological nutrient removal systems.


Assuntos
Betaproteobacteria , Metagenoma , RNA Ribossômico 16S/genética , Metagenoma/genética , Filogenia , Águas Residuárias , Fósforo
3.
Psychol Health ; : 1-19, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37654203

RESUMO

Objective: Medically unexplained symptoms (MUS), such as chronic fatigue syndrome, irritable bowel syndrome, and Gulf War Illness (GWI), are difficult to treat. Concordance-shared understanding between patient and provider about illness causes, course, and treatment-is an essential component of high-quality care for people with MUS. This qualitative paper focuses on the experiences of United States military Veterans living with GWI who have endured unique healthcare challenges. Methods & Measures: Qualitative interviews were conducted with 31 Veterans with GWI to explore factors that contribute to and detract from concordance with their Veteran Affairs (VA) healthcare providers. In addition to being seen by VA primary care, over half of participants also sought care at a War Related Illness and Injury Study Center, which specializes in post-deployment health. Deductive and inductive codes were used to organize the data, and themes were identified through iterative review of coded data. Results: Major themes associated with patient-provider concordance included validation of illness experiences, perceived provider expertise in GWI/MUS, and trust in providers. Invalidation, low provider expertise, and distrust detracted from concordance. Conclusion: These findings suggest providers can foster concordance with MUS patients by legitimizing patients' experiences, communicating knowledge about MUS, and establishing trust.

4.
Stem Cell Res ; 71: 103191, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37659345

RESUMO

Developmental and epileptic encephalopathies (DEEs) are a group of severe, early-onset epilepsies which are often caused by genetic mutations in ion channels. Mutations in KCNQ2, which encodes the voltage-gated potassium channel Kv7.2, is known to cause DEE. Here, we generated three iPSC lines from dermal fibroblasts of a 5 year-old male patient with the KCNQ2 c.881C > T (p.Ala294Val) pathogenic heterozygous variant and three iPSC lines from a healthy sibling control. These iPSC lines have been validated by SNP karyotyping, STR analysis, expression of pluripotent genes, the capacity to differentiate into three germ layers and confirmation of the mutation in the patient.


Assuntos
Encefalopatias , Células-Tronco Pluripotentes Induzidas , Masculino , Humanos , Pré-Escolar , Camadas Germinativas , Heterozigoto , Cariotipagem , Canal de Potássio KCNQ2/genética
5.
Int J Mol Sci ; 24(12)2023 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-37373396

RESUMO

The spinal cord has a poor ability to regenerate after an injury, which may be due to cell loss, cyst formation, inflammation, and scarring. A promising approach to treating a spinal cord injury (SCI) is the use of biomaterials. We have developed a novel hydrogel scaffold fabricated from oligo(poly(ethylene glycol) fumarate) (OPF) as a 0.08 mm thick sheet containing polymer ridges and a cell-attractive surface on the other side. When the cells are cultured on OPF via chemical patterning, the cells attach, align, and deposit ECM along the direction of the pattern. Animals implanted with the rolled scaffold sheets had greater hindlimb recovery compared to that of the multichannel scaffold control, which is likely due to the greater number of axons growing across it. The immune cell number (microglia or hemopoietic cells: 50-120 cells/mm2 in all conditions), scarring (5-10% in all conditions), and ECM deposits (Laminin or Fibronectin: approximately 10-20% in all conditions) were equal in all conditions. Overall, the results suggest that the scaffold sheets promote axon outgrowth that can be guided across the scaffold, thereby promoting hindlimb recovery. This study provides a hydrogel scaffold construct that can be used in vitro for cell characterization or in vivo for future neuroprosthetics, devices, or cell and ECM delivery.


Assuntos
Organofosfonatos , Traumatismos da Medula Espinal , Ratos , Animais , Hidrogéis/química , Organofosfonatos/metabolismo , Cicatriz/patologia , Ratos Sprague-Dawley , Regeneração Nervosa , Traumatismos da Medula Espinal/tratamento farmacológico , Traumatismos da Medula Espinal/metabolismo , Medula Espinal/metabolismo , Axônios/patologia , Alicerces Teciduais/química
6.
Stem Cell Res ; 69: 103093, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37071954

RESUMO

KCNQ2 encodes the potassium-gated voltage channel Kv7.2, responsible for the M-current, which contributes to neuronal resting membrane potential. Pathogenic variants in KCNQ2 cause early onset epilepsies, developmental and epileptic encephalopathies. In this study, we generated three iPSC lines from dermal fibroblasts of a 5 year-old female patient with the KCNQ2 c.638C > T (p.Arg213Gln) pathogenic heterozygous variant and three iPSC lines from a healthy sibling control. These iPSC lines were validated by confirming the targeted mutation, SNP karyotyping, STR analysis, pluripotent gene expression, differentiation capacity into three germ layers, and were free of transgene integration and Mycoplasma.


Assuntos
Encefalopatias , Células-Tronco Pluripotentes Induzidas , Feminino , Humanos , Pré-Escolar , Células-Tronco Pluripotentes Induzidas/metabolismo , Neurônios , Diferenciação Celular , Encefalopatias/genética , Mutação , Canal de Potássio KCNQ2/genética , Canal de Potássio KCNQ2/metabolismo
7.
Water Sci Technol ; 85(2): 578-590, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35100140

RESUMO

Sensor driven aeration control strategies have recently been developed as a means to efficiently carry out biological nutrient removal (BNR) and reduce aeration costs in wastewater treatment plants. Under load-based aeration control, often implemented as ammonia-based aeration control (ABAC), airflow is regulated to meet desired effluent standards without specifically setting dissolved oxygen (DO) targets. Another approach to reduce aeration requirements is to constantly maintain low DO conditions and allow the microbial community to adapt to the low-DO environment. In this study, we compared the performance of two pilot-scale BNR treatment trains that simultaneously used ABAC and low-DO operation to evaluate the combination of these two strategies. One pilot plant was operated with continuous ABAC while the other one used intermittent ABAC. Both processes achieved greater than 90% total Kjehldal nitrogen (TKN) removal, 60% total nitrogen removal, and nearly 90% total phosphorus removal. Increasing the solids retention time (SRT) during the period of cold (∼12 °C) water temperatures helped maintain ammonia removal performance under low-DO conditions. However, both processes experienced poor solids settling characteristics during winter. While settling was recovered under warmer temperatures, improving settling quality remains a challenge under low-DO operation.


Assuntos
Amônia , Eliminação de Resíduos Líquidos , Reatores Biológicos , Nutrientes , Oxigênio , Esgotos
8.
Arch Pathol Lab Med ; 146(4): 440-450, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-34003251

RESUMO

CONTEXT.­: The original guideline, "Validating Whole Slide Imaging for Diagnostic Purposes in Pathology," was published in 2013 and included 12 guideline statements. The College of American Pathologists convened an expert panel to update the guideline following standards established by the National Academies of Medicine for developing trustworthy clinical practice guidelines. OBJECTIVE.­: To assess evidence published since the release of the original guideline and provide updated recommendations for validating whole slide imaging (WSI) systems used for diagnostic purposes. DESIGN.­: An expert panel performed a systematic review of the literature. Frozen sections, anatomic pathology specimens (biopsies, curettings, and resections), and hematopathology cases were included. Cytology cases were excluded. Using the Grading of Recommendations Assessment, Development, and Evaluation approach, the panel reassessed and updated the original guideline recommendations. RESULTS.­: Three strong recommendations and 9 good practice statements are offered to assist laboratories with validating WSI digital pathology systems. CONCLUSIONS.­: Systematic review of literature following release of the 2013 guideline reaffirms the use of a validation set of at least 60 cases, establishing intraobserver diagnostic concordance between WSI and glass slides and the use of a 2-week washout period between modalities. Although all discordances between WSI and glass slide diagnoses discovered during validation need to be reconciled, laboratories should be particularly concerned if their overall WSI-glass slide concordance is less than 95%.


Assuntos
Interpretação de Imagem Assistida por Computador , Microscopia , Humanos , Biópsia , Interpretação de Imagem Assistida por Computador/métodos , Laboratórios , Microscopia/métodos , Variações Dependentes do Observador , Revisões Sistemáticas como Assunto
9.
J Sch Health ; 92(3): 325-329, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34918341

RESUMO

BACKGROUND: Dental caries is the most common chronic illness for children. Caries can reduce the quality of life, cause missed classroom hours, and decrease cognition. Strategies to improve children's oral health must be evidence-based, developed, and implemented in consultation with communities. METHODS: A community-academic partnership was formed between East Carolina University School of Dental Medicine and the Bertie County Public School District to develop and implement a school-based oral health prevention program using the PRECEDE-PROCEED Model. RESULTS: The PRECEDE component involved social, epidemiological, environmental, educational, ecological, administrative, and policy factors that informed the development of the oral health program. The PROCEED component consisted of implementation and evaluation. CONCLUSIONS: School-based oral health programs can increase access to care for vulnerable children and improve learning. The application of the PRECEDE-PROCEED model proved to be a valuable method for developing, implementing, and evaluating a school-based oral health program.


Assuntos
Cárie Dentária , Saúde Bucal , Criança , Cárie Dentária/epidemiologia , Cárie Dentária/prevenção & controle , Humanos , North Carolina , Qualidade de Vida , População Rural
10.
Appl Magn Reson ; 52(8): 995-1015, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34720439

RESUMO

In the study of biological structures, pulse dipolar spectroscopy (PDS) is used to elucidate spin-spin distances at nanometre-scale by measuring dipole-dipole interactions between paramagnetic centres. The PDS methods of Double Electron Electron Resonance (DEER) and Relaxation Induced Dipolar Modulation Enhancement (RIDME) are employed, and their results compared, for the measurement of the dipolar coupling between nitroxide spin labels and copper-II (Cu(II)) paramagnetic centres within the copper amine oxidase from Arthrobacter globiformis (AGAO). The distance distribution results obtained indicate that two distinct distances can be measured, with the longer of these at c.a. 5 nm. Conditions for optimising the RIDME experiment such that it may outperform DEER for these long distances are discussed. Modelling methods are used to show that the distances obtained after data analysis are consistent with the structure of AGAO. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00723-021-01321-6.

11.
Breast ; 60: 223-229, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34739890

RESUMO

Oligometastatic breast cancer (OMBC) is a heterogeneous disease with intrinsic biological diversity. It is increasingly accepted in clinical practice that patients with OMBC could be treated with the expectation of long-term disease remission. Local ablative treatments, such as radiotherapy or surgery have a role in this setting. At present, patients that may benefit are characterised by low tumour burden, long disease-free interval and the capacity to completely ablate all sites of disease. In the future, biological or genomic classifiers may help predict which patients may benefit the most from local ablative treatments. This review provides an overview of the proposed classifications of oligometastatic disease and outlines the standard systemic treatment options of endocrine therapy, chemotherapy, and immunotherapy. The evidence for localized treatment with stereotactic ablative body radiotherapy (SABR) is presented. We discuss current active trials in oligometastatic cancer and discuss potential future directions for the use of SABR in the treatment of OMBC.


Assuntos
Neoplasias da Mama , Radiocirurgia , Neoplasias da Mama/terapia , Intervalo Livre de Doença , Feminino , Humanos , Carga Tumoral
13.
Elife ; 102021 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-33779546

RESUMO

While the mechanisms by which chemical signals control cell fate have been well studied, the impact of mechanical inputs on cell fate decisions is not well understood. Here, using the well-defined system of keratinocyte differentiation in the skin, we examine whether and how direct force transmission to the nucleus regulates epidermal cell fate. Using a molecular biosensor, we find that tension on the nucleus through linker of nucleoskeleton and cytoskeleton (LINC) complexes requires integrin engagement in undifferentiated epidermal stem cells and is released during differentiation concomitant with decreased tension on A-type lamins. LINC complex ablation in mice reveals that LINC complexes are required to repress epidermal differentiation in vivo and in vitro and influence accessibility of epidermal differentiation genes, suggesting that force transduction from engaged integrins to the nucleus plays a role in maintaining keratinocyte progenitors. This work reveals a direct mechanotransduction pathway capable of relaying adhesion-specific signals to regulate cell fate.


Assuntos
Epiderme/fisiologia , Mecanotransdução Celular/fisiologia , Lâmina Nuclear/fisiologia , Plaquinas/genética , Animais , Diferenciação Celular , Feminino , Integrinas/metabolismo , Lamina Tipo A/metabolismo , Camundongos , Plaquinas/metabolismo
14.
Cartilage ; 12(2): 211-221, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33722083

RESUMO

OBJECTIVE: To investigate the diffusion trajectory of a cationic contrast medium (CA4+) into equine articular cartilage, and to assess normal and degenerative equine articular cartilage using cationic contrast-enhanced computed tomography (CECT). DESIGN: In the first experiment (Exp1), equine osteochondral specimens were serially imaged with cationic CECT to establish the diffusion time constant and time to reach equilibrium in healthy articular cartilage. In a separate experiment (Exp2), articular cartilage defects were created on the femoral trochlea (defect joint) in a juvenile horse, while the opposite joint was a sham-operated control. After 7 weeks, osteochondral biopsies were collected throughout the articular surfaces of both joints. Biopsies were analyzed for cationic CECT attenuation, glycosaminoglycan (GAG) content, mechanical stiffness (Eeq), and histology. Imaging, biochemical and mechanical data were compared between defect and control joints. RESULTS: Exp1: The mean diffusion time constant was longer for medial condyle cartilage (3.05 ± 0.1 hours) than lateral condyle cartilage (1.54 ± 0.3 hours, P = 0.04). Exp2: Cationic CECT attenuation was lower in the defect joint than the control joint (P = 0.005) and also varied by anatomic location (P = 0.045). Mean cationic CECT attenuation from the lateral trochlear ridge was lower in the defect joint than in the control joint (2223 ± 329 HU and 2667 ± 540 HU, respectively; P = 0.02). Cationic CECT attenuation was strongly correlated with both GAG (ρ = 0.79, P < 0.0001) and Eeq (ρ = 0.61, P < 0.0001). CONCLUSIONS: The equilibration time of CA4+ into equine articular cartilage is affected by tissue volume. Quantitative cationic CECT imaging reflects the biochemical, biomechanical and histological state of normal and degenerative equine articular cartilage.


Assuntos
Cartilagem Articular/diagnóstico por imagem , Meios de Contraste , Osteoartrite/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Animais , Fenômenos Biomecânicos , Cartilagem Articular/fisiopatologia , Modelos Animais de Doenças , Glicosaminoglicanos/metabolismo , Cavalos , Osteoartrite/fisiopatologia , Osteoartrite/veterinária , Amplitude de Movimento Articular
15.
Int J Yoga Therap ; 31(1)2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33444458

RESUMO

The primary objective of this work was to determine the feasibility of a randomized trial of individualized yoga for children receiving intensive chemotherapy and for hematopoietic stem cell transplantation (HSCT) recipients outside of the principal coordinating institution. We evaluated the feasibility of a randomized trial of individualized yoga versus an iPad control program at a site where external yoga instructors were hired and compensated per session. Subjects were children receiving intensive chemotherapy for hematological malignancies and autologous or allogeneic HSCT recipients expected to be hospitalized for 3 weeks. Yoga or iPad control contact occurred daily for 21 days (excluding weekends and holidays); fatigue and quality-of-life outcomes were measured at baseline, day 10, and day 21. Ten eligible subjects were identified; six subjects consented and were enrolled. Three were randomized to the individualized yoga intervention and three to the iPad control program. The median age of participants was 12 (range 8-15) years, and 2 (33%) were boys. Challenges primarily related to the hiring of yoga instructors who were not trained in research methods. We found issues with: (1) logistics of hiring, training, and retaining instructors; (2) communication between teams; (3) fidelity to the protocol and outcome assessments; and (4) ensuring safety. We found that a randomized trial of individualized yoga presented new challenges when relying on externally contracted yoga instructors. Future multicenter studies of yoga should seek to better integrate practitioners within the research team to improve processes, communication, fidelity to the protocol, and safety.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Meditação , Neoplasias , Yoga , Adolescente , Criança , Fadiga , Humanos , Masculino
17.
Exp Brain Res ; 238(9): 2053-2066, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32632574

RESUMO

The rubber-hand illusion is an illusion where a person embodies a rubber hand as if it were their own. After embodiment, many studies have threatened the false hand and measured physiological responses to the threat for the purposes of verification. For the first time, we tested if embodiment of the false hand could be modulated with a fearful stimulus already present prior to the elicitation of the illusion. This was done by having a live huntsman spider placed on top of the false hand for the entire duration of testing. We also examined if the procedure could change implicit attitudes towards spiders. The results revealed that the embodiment of the false hand with the fearful stimulus on top of it occurred as strongly as when the latter was not there, suggesting that the top-down processing of fearful stimuli is not strong enough to influence bottom-up processes. However, implicit attitudes towards spiders did not change.


Assuntos
Ilusões , Aranhas , Percepção do Tato , Animais , Imagem Corporal , Mãos , Humanos , Propriocepção
18.
Sci Rep ; 10(1): 6598, 2020 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-32313087

RESUMO

Triple negative breast cancer (TNBC) is an aggressive breast cancer subtype. Recent studies have shown that MHC class II (MHCII) expression and tumor infiltrating lymphocytes are important prognostic factors in patients with TNBC, although the relative importance of lymphocyte subsets and associated protein expression is incompletely understood. NanoString Digital Spatial Profiling (DSP) allows for spatially resolved, highly multiplexed quantification of proteins in clinical samples. In this study, we sought to determine if DSP could be used to characterize expression of MHCII and other immune related proteins in tumor epithelial versus stromal compartments of patient-derived TNBCs (N = 10) using a panel of 39 markers. We confirmed that a subset of TNBCs have elevated expression of HLA-DR in tumor epithelial cells; HLA-DR expression was also significantly higher in the tumors of patients with long-term disease-free survival when compared to patients that relapsed. HLA-DR expression in the epithelial compartment was correlated with high expression of CD4 and ICOS in the stromal compartment of the same tumors. We also identified candidate protein biomarkers with significant differential expression between patients that relapsed versus those that did not. In conclusion, DSP is a powerful method that allows for quantification of proteins in the immune microenvironment of TNBCs.


Assuntos
Proteínas de Neoplasias/metabolismo , Neoplasias de Mama Triplo Negativas/imunologia , Microambiente Tumoral/imunologia , Antígenos CD4/metabolismo , Linhagem Celular Tumoral , Antígenos HLA-DR/imunologia , Humanos , Proteína Coestimuladora de Linfócitos T Induzíveis/metabolismo , Linfócitos/patologia , Prognóstico , Recidiva , Células Estromais/patologia , Neoplasias de Mama Triplo Negativas/patologia
20.
Med Eng Phys ; 73: 1-8, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31526590

RESUMO

Understanding hip osteoarthritis requires new investigational tools for quantitative studies of biophysical and biomechanical properties as well as for determination of structure. Three new protocols to study pathological changes in cartilage and to measure cartilage thickness in intact human hips are described using synchrotron contrast enhanced computed tomography (sCECT) with the iodinated contrast agent CA4+. Ten human cadaver hips were prepared and injected with CA4+ using three different methods, all of which included rotation and distraction of the joint. CA4+ diffusion into cartilage was monitored using sCECT. The thickness of acetabular and femoral cartilage was also measured. Diffusion times ranged from 2 h to 75 h, depending on the injection protocol and the cartilage region. Direct single injection of the contrast through the labrum resulted in the fastest diffusion times. The iodine attenuation coefficient, which reflects the contrast agent distribution in the cartilage, ranged from 0.0142/cm to 0.1457/cm. Three injections at the head/neck conjunction area yielded the highest iodine attenuation coefficients in cartilage. The femoral cartilage in the Superior-Medial compartment was significantly thicker than in the other 3 femoral compartments, and femoral cartilage in the Superior-Anterior compartment was significantly thinner than the other 3 femoral compartments. The acetabular cartilage in the Superior compartment was significantly thicker than that in the Superior-Posterior compartment. sCECT with CA4+ allows assessment of hip cartilage thickness with 0.1 mm isotropic voxel size, sufficient for evaluating cartilage pathology and biomechanics.


Assuntos
Cartilagem Articular/diagnóstico por imagem , Meios de Contraste , Articulação do Quadril/diagnóstico por imagem , Síncrotrons , Tomografia Computadorizada por Raios X/instrumentação , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
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