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Systemic administration of adeno-associated virus (AAV) vectors for spinal cord gene therapy has challenges including toxicity at high doses and pre-existing immunity that reduces efficacy. Intrathecal (IT) delivery of AAV vectors into cerebral spinal fluid can avoid many issues, although distribution of the vector throughout the spinal cord is limited, and vector entry to the periphery sometimes initiates hepatotoxicity. Here we performed biopanning in non-human primates (NHPs) with an IT injected AAV9 peptide display library. We identified top candidates by sequencing inserts of AAV DNA isolated from whole tissue, nuclei, or nuclei from transgene-expressing cells. These barcoded candidates were pooled with AAV9 and compared for biodistribution and transgene expression in spinal cord and liver of IT injected NHPs. Most candidates displayed increased retention in spinal cord compared with AAV9. Greater spread from the lumbar to the thoracic and cervical regions was observed for several capsids. Furthermore, several capsids displayed decreased biodistribution to the liver compared with AAV9, providing a high on-target/low off-target biodistribution. Finally, we tested top candidates in human spinal cord organoids and found them to outperform AAV9 in efficiency of transgene expression in neurons and astrocytes. These capsids have potential to serve as leading-edge delivery vehicles for spinal cord-directed gene therapies.
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Dependovirus , Terapia Genética , Vetores Genéticos , Medula Espinal , Dependovirus/genética , Animais , Medula Espinal/metabolismo , Vetores Genéticos/administração & dosagem , Vetores Genéticos/genética , Humanos , Terapia Genética/métodos , Transgenes , Técnicas de Transferência de Genes , Capsídeo/metabolismo , Distribuição Tecidual , Injeções Espinhais , Transdução Genética , Macaca mulatta , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/metabolismoRESUMO
BACKGROUND: Ultrasound is the imaging modality of choice in children presenting to the emergency department (ED) with soft tissue neck swelling. Point of care ultrasound (POCUS) has good accuracy when compared to comprehensive radiology department ultrasound (RADUS). POCUS could potentially improve ED length of stay (LOS) by improving efficiency. We aimed to evaluate the LOS of pediatric patients seen in ED with soft tissue neck swelling who received POCUS compared to RADUS. We determined unscheduled 30-day return visit rates in both groups as a balancing measure. METHODS: We performed a retrospective review of the electronic medical record for our cross-sectional study of discharged patients ≤21â¯years of age who had a neck ultrasound performed by a credentialed POCUS physician or by the radiology department between July 2014 and January 2020. We included patients who had both POCUS and RADUS in the POCUS group. We compared median ED LOS in both groups using the Mann Whitney U test and proportion of unscheduled return visits to the ED in both groups using odds ratio and 95% CI. RESULTS: There were 925 patients: 76 with only POCUS, 6 with POCUS and RADUS, and 843 with only RADUS performed. Median LOS in the POCUS group was 68.5 min (IQR 38.3120.3) versus 154.0 min (IQR 111.0, 211.0) in the RADUS group (pâ¯<â¯0.001). Return visit overall was 7.6%: 13.2% in the POCUS group versus 7.1% in the RADUS group (pâ¯=â¯0.07). CONCLUSION: Pediatric patients evaluated in the ED for soft tissue neck swelling had a shorter LOS with POCUS than with RADUS without a statistically significant increase in 30-day return visits. We suggest a "POCUS First" approach to the care of these patients.
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Abscesso/diagnóstico por imagem , Celulite (Flegmão)/diagnóstico por imagem , Edema/diagnóstico por imagem , Serviço Hospitalar de Emergência , Tempo de Internação/estatística & dados numéricos , Linfadenopatia/diagnóstico por imagem , Pescoço/diagnóstico por imagem , Parotidite/diagnóstico por imagem , Abscesso/complicações , Adolescente , Celulite (Flegmão)/complicações , Criança , Pré-Escolar , Edema/etiologia , Feminino , Humanos , Lactente , Recém-Nascido , Linfonodos/diagnóstico por imagem , Linfonodos/patologia , Linfadenopatia/complicações , Masculino , Necrose , Parotidite/complicações , Readmissão do Paciente/estatística & dados numéricos , Testes Imediatos , Estudos Retrospectivos , Ultrassonografia , Adulto JovemRESUMO
BACKGROUND: Acute heart failure (AHF) in children is associated with significant disease burden with high rates of morbidity, mortality, and resource utilization. These children often present to the emergency department with clinical features that mimic common childhood illnesses. Cardiac point-of-care ultrasound (POCUS) can be an effective tool for rapidly identifying abnormal cardiac function. CASE REPORTS: This case series documents 10 children presenting with AHF between 2016 and 2019 and demonstrates how pediatric emergency physicians used cardiac POCUS to expedite their diagnosis, management, and disposition. All cardiac POCUS was performed before comprehensive echocardiograms were completed. One case is described in detail; the other cases are summarized in a Table. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Early recognition of AHF is critical to reduce pediatric morbidity and mortality. With proper training, cardiac POCUS can be an effective adjunct and should be considered for the early diagnosis and treatment of infants and children with AHF.
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Insuficiência Cardíaca , Sistemas Automatizados de Assistência Junto ao Leito , Criança , Serviço Hospitalar de Emergência , Insuficiência Cardíaca/diagnóstico , Humanos , Lactente , Testes Imediatos , UltrassonografiaRESUMO
Fragile X syndrome (FXS) is the most common genetic form of intellectual disability caused by a CGG repeat expansion in the 5'-UTR of the Fragile X mental retardation gene FMR1, triggering epigenetic silencing and the subsequent absence of the protein, FMRP. Reactivation of FMR1 represents an attractive therapeutic strategy targeting the genetic root cause of FXS. However, largely missing in the FXS field is an understanding of how much FMR1 reactivation is required to rescue FMRP-dependent mutant phenotypes. Here, we utilize FXS patient-derived excitatory neurons to model FXS in vitro and confirm that the absence of FMRP leads to neuronal hyperactivity. We further determined the levels of FMRP and the percentage of FMRP-positive cells necessary to correct this phenotype utilizing a mixed and mosaic neuronal culture system and a combination of CRISPR, antisense and expression technologies to titrate FMRP in FXS and WT neurons. Our data demonstrate that restoration of greater than 5% of overall FMRP expression levels or greater than 20% FMRP-expressing neurons in a mosaic pattern is sufficient to normalize a FMRP-dependent, hyperactive phenotype in FXS iPSC-derived neurons.
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Síndrome do Cromossomo X Frágil , Células-Tronco Pluripotentes Induzidas , Epigênese Genética , Proteína do X Frágil da Deficiência Intelectual/genética , Síndrome do Cromossomo X Frágil/genética , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Neurônios/metabolismoRESUMO
The differential diagnosis for facial swelling is broad and can be a diagnostic challenge in the pediatric emergency department. We describe the first pediatric case of acute parotitis with sialolithiasis where the diagnosis was facilitated by point-of-care ultrasound.
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Parotidite/diagnóstico por imagem , Sistemas Automatizados de Assistência Junto ao Leito , Ultrassonografia/métodos , Pré-Escolar , Diagnóstico Diferencial , Edema/complicações , Edema/diagnóstico por imagem , Face , Humanos , Masculino , Glândula Parótida/diagnóstico por imagem , Glândula Parótida/patologia , Parotidite/complicações , Punica granatum , Cálculos das Glândulas Salivares/complicações , Cálculos das Glândulas Salivares/diagnóstico por imagemRESUMO
Organogenesis requires coordinated regulation of cellular differentiation and morphogenesis. Cartilage cells in the vertebrate skeleton form polarized stacks, which drive the elongation and shaping of skeletal primordia. Here we show that an atypical cadherin, Fat3, and its partner Dachsous-2 (Dchs2), control polarized cell-cell intercalation of cartilage precursors during craniofacial development. In zebrafish embryos deficient in Fat3 or Dchs2, chondrocytes fail to stack and misregulate expression of sox9a. Similar morphogenetic defects occur in rerea/atr2a-/- mutants, and Fat3 binds REREa, consistent with a model in which Fat3, Dchs2 and REREa interact to control polarized cell-cell intercalation and simultaneously control differentiation through Sox9. Chimaeric analyses support such a model, and reveal long-range influences of all three factors, consistent with the activation of a secondary signal that regulates polarized cell-cell intercalation. This coordinates the spatial and temporal morphogenesis of chondrocytes to shape skeletal primordia and defects in these processes underlie human skeletal malformations. Similar links between cell polarity and differentiation mechanisms are also likely to control organ formation in other contexts.
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Caderinas/genética , Cartilagem/crescimento & desenvolvimento , Diferenciação Celular/genética , Polaridade Celular/genética , Morfogênese/genética , Proteínas de Peixe-Zebra/genética , Animais , Caderinas/biossíntese , Comunicação Celular , Condrócitos/metabolismo , Desenvolvimento Embrionário , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Fatores de Transcrição SOX9/biossíntese , Peixe-Zebra/genética , Peixe-Zebra/crescimento & desenvolvimentoRESUMO
BACKGROUND: although nurses often place peripheral intravenous (IV) catheters, little is known about their perceptions regarding use of ultrasound guidance. AIM: the authors aimed to determine paediatric emergency department nurses' attitudes toward ultrasound-guided IV access techniques and assessed practice change after training. METHOD: In a cross-sectional study of nurses, they had didactic and hands-on practice sessions, using three short-axis ultrasound-guided IV access techniques on gel models. Outcomes included likability and ease of learning and performing the techniques. A 3-month follow-up questionnaire assessed attitudes and behavioural changes. RESULTS: 18 nurses were enrolled and 17 analysed. Participants liked all three techniques and thought they were easy to learn and perform. Eighty-two percent of the nurses used at least one technique clinically. The two-person self-guided technique was most preferred (65%) and used 3 months later (65%). CONCLUSIONS: nurses reported generally positive attitudes toward all three ultrasound-guided IV access techniques, but preferred the two-person self-guided technique. Owing to the small sample size, these results cannot be generalised and further research is needed.
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Atitude do Pessoal de Saúde , Cateterismo Periférico/métodos , Cateterismo Periférico/enfermagem , Serviço Hospitalar de Emergência , Recursos Humanos de Enfermagem Hospitalar , Ultrassonografia de Intervenção , Adulto , Estudos Transversais , Enfermagem em Emergência , Feminino , Hospitais Pediátricos , Humanos , Masculino , Enfermagem Pediátrica , Distribuição AleatóriaRESUMO
We report a case of a pediatric patient with an initial diagnosis of peritonsillar cellulitis made by otolaryngology. The findings from a subsequent transcutaneous point-of-care ultrasound by a pediatric emergency physician directly affected the decision to perform needle aspiration. Sonographic characteristics of a peritonsillar abscess may be helpful in the prompt diagnosis of peritonsillar abscess.
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Abscesso Peritonsilar/diagnóstico por imagem , Sistemas Automatizados de Assistência Junto ao Leito , Ultrassonografia/métodos , Adolescente , Antibacterianos/uso terapêutico , Diagnóstico Diferencial , Serviço Hospitalar de Emergência , Humanos , Masculino , Abscesso Peritonsilar/terapia , SucçãoRESUMO
PURPOSE OF REVIEW: We present data from recently conducted research on the diagnosis and management of skin and soft tissue infections (SSTIs) in children. RECENT FINDINGS: Current research in the area of SSTIs (cellulitis and abscess) has focused on the use of ultrasound, risk factors associated with bacteremia, antibiotic choice, and incision and drainage (I&D) practices. When clinical examination is equivocal at distinguishing abscess from cellulitis, ultrasound can aid in the diagnosis and alter management. Bacteremia is rare in immunocompetent children with uncomplicated SSTIs; blood cultures may be reserved for complicated cases and for those who are systemically ill. Despite the increased prevalence of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA), I&D without antibiotics remains the first-line therapy for abscess. Antibiotics for uncomplicated cellulitis should target ß-hemolytic streptococci and methicillin-susceptible S. aureus (MSSA). There are significant variations in pain and sedation practices for I&D, with substantive evidence for the use of topical anesthetics. Wound packing after I&D may not confer significant benefit. SUMMARY: Evidence to aid in the diagnosis and management of SSTIs in children has emerged in recent years; however, larger prospective pediatric studies are needed.
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Abscesso/microbiologia , Antibacterianos/uso terapêutico , Celulite (Flegmão)/microbiologia , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções dos Tecidos Moles/microbiologia , Infecções Cutâneas Estafilocócicas/microbiologia , Abscesso/epidemiologia , Abscesso/terapia , Bacteriemia , Celulite (Flegmão)/epidemiologia , Celulite (Flegmão)/terapia , Criança , Pré-Escolar , Terapia Combinada , Drenagem/métodos , Medicina Baseada em Evidências , Humanos , Prevalência , Estudos Prospectivos , Infecções dos Tecidos Moles/epidemiologia , Infecções dos Tecidos Moles/terapia , Infecções Cutâneas Estafilocócicas/epidemiologia , Infecções Cutâneas Estafilocócicas/terapiaRESUMO
BACKGROUND: Although renal colic in children in the United States remains relatively uncommon compared to in adults, its incidence has nearly doubled from 1999 to 2008. Noncontrast computed tomography (CT) is the current standard for the evaluation of suspected renal colic, given its high sensitivity and specificity. However, the greater lifetime risk of radiation-induced cancer from CT in pediatric patients has led to efforts to minimize radiation exposure. Additionally, pediatric renal colic is often recurrent, which might require multiple imaging studies during their lifetime. Point-of-care ultrasound (POCUS) by emergency physicians avoids radiation, has a low marginal cost, can be performed concurrently with other management, and allows for earlier diagnosis and more rapid treatment of renal colic. Adult randomized controlled trial evidence supports using POCUS as the initial approach to imaging and management of suspected renal colic. However, there remain limited data on POCUS in children for renal colic. CASE REPORT: This is a case series where the sonographic findings of hydronephrosis, ureteral jets, "twinkling artifact," and the identification of urinary tract stones were used to evaluate adolescent and pediatric patients with renal colic. We report five cases of renal colic in adolescent and pediatric patients where urolithiasis was confirmed by using POCUS and irradiation by CT was avoided in all 5 patients. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: POCUS can provide information about the presence or absence of urinary tract stones as well as obstruction of the collecting system without the cost and radiation exposure of CT.
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Sistemas Automatizados de Assistência Junto ao Leito , Cólica Renal/etiologia , Urolitíase/diagnóstico por imagem , Adolescente , Pré-Escolar , Feminino , Humanos , Hidronefrose/diagnóstico por imagem , Masculino , Ultrassonografia , Obstrução Ureteral/diagnóstico por imagem , Adulto JovemRESUMO
There is controversy regarding needle aspiration for primary spontaneous pneumothorax (PSP), with contradictory recommendations between the American College of Chest Physicians consensus statement (2001), which suggests that needle aspiration has little place in the management of PSP, and the British Thoracic Society guidelines (2010), which recommend that needle aspiration be attempted first for all cases of PSP where drainage is deemed necessary. Studies have shown that there is no significant difference between needle aspiration and tube thoracostomy with regard to safety, rates of immediate success, and early failure and has the advantages of decreasing pain and reducing rates of hospital admission and duration of hospital stay compared with tube thoracostomy. Point-of-care ultrasound (US) can facilitate needle aspiration by decreasing the risk of complications and detect pneumothorax resolution during or re-expansion after the procedure. This is a case series where the sonographic finding of the "lung point" on point-of-care US was used to facilitate needle aspiration to monitor pneumothorax resolution during or re-expansion after the procedure. We report 3 cases of PSP in adolescents presenting to the pediatric emergency department (ED), where needle aspiration was safely performed by using US to track the sonographic finding of the lung point. This technique allows the determination of pneumothorax resolution or re-expansion in real time. Point-of-care US may assist in the evaluation and management of spontaneous pneumothorax in the pediatric ED. Ultrasound-assisted needle aspiration may be a safe and less painful option for pediatric ED patients with PSP.
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Agulhas , Pneumotórax/diagnóstico por imagem , Pneumotórax/cirurgia , Sistemas Automatizados de Assistência Junto ao Leito , Sucção/instrumentação , Ultrassonografia de Intervenção , Adolescente , Humanos , Masculino , Adulto JovemRESUMO
Metastatic uveal melanoma (mUM) is a rare cancer with poor prognosis, but novel treatments are emerging. Currently, there are no mUM-specific health-related quality of life (HRQL) questionnaires available for clinical research. We aimed to explore how mUM and its treatment affect HRQL and assess the content validity of existing questionnaires. Participants were patients with mUM and healthcare professionals involved in their care. Qualitative data were collected using semi-structured interviews and focus groups. Data collection and analysis used an integrative approach involving inductive questions/coding to elicit new concepts and deductive questions/coding based on domains of existing HRQL questionnaires. Initial interviews/focus groups focussed on HRQL questionnaires designed for patients with uveal melanoma or liver metastases. As new concepts were elicited, domains and items from other questionnaires were subsequently added. Seventeen patients and 16 clinicians participated. HRQL concerns assessed by uveal melanoma-specific questionnaires were largely resolved by the time of metastasis. The Functional Assessment of Cancer Therapy - Immunotherapy Module (FACT-ICM) adequately captured most immunotherapy-related side effects during initial treatment cycles. However, most patients emphasised emotional impacts over physical ones, focussing on the existential threat posed by disease amidst uncertainty about treatment accessibility and effectiveness. Patients were also concerned with treatment burden, including time commitment, travel, need for hospitalisation, and expenses. The relative importance of HRQL issues varied over time and across treatment modalities, with no single questionnaire being sufficient. Pending further development and psychometric testing, clinical researchers may need to take a modular approach to measuring the HRQL impacts of mUM.
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Melanoma , Pesquisa Qualitativa , Qualidade de Vida , Neoplasias Uveais , Humanos , Neoplasias Uveais/psicologia , Neoplasias Uveais/patologia , Melanoma/psicologia , Feminino , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Idoso , Adulto , Metástase NeoplásicaRESUMO
Adeno-associated viruses (AAV) are promising vectors for gene therapy due to their efficacy in vivo. However, there is room for improvement to address key limitations such as the pre-existing immunity to AAV in patients, high-dose toxicity, and relatively low efficiency for some cell types. This study introduces a metabolic engineering approach, using knockout of the enzyme phosphatidylserine synthase 1 (PTDSS1) to increase the abundance of extracellular vesicle-enclosed AAV (EV-AAV) relative to free AAV in the supernatant of producer cells, simplifying downstream purification processes. The lipid-engineered HEK293T-ΔPTDSS1 cell line achieved a 42.7-fold enrichment of EV-AAV9 compared to free AAV9 in the supernatant. The rational genetic strategy also led to a 300-fold decrease of free AAV in supernatant compared to wild-type HEK293T. The membrane-engineered EV-AAV9 (mEV-AAV9) showed unique envelope composition alterations, including cholesterol enrichment and improved transduction efficiency in human AC16 cardiomyocytes by 1.5-fold compared to conventional EV-AAV9 and by 11-fold compared to non-enveloped AAV9. Robust in-vivo transduction four weeks after intraparenchymal administration of mEV-AAV9 was observed in the murine brain. This study shows promise in the potential of lipid metabolic engineering strategies to improve the efficiency and process development of enveloped gene delivery vectors. Keywords: membrane engineering, EV-AAV, upstream, downstream.
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INTRODUCTION: Utility values offer a quantitative means to evaluate the impact of novel cancer treatments on patients' quality of life (QoL). However, the multiple methods available for valuing QoL present challenges in selecting the most appropriate method across different contexts. AREAS COVERED: This review provides cancer clinicians and researchers with an overview of methods to value QoL for economic evaluations, including standalone and derived preference-based measures (PBMs) and direct preference elicitation methods. Recent developments are described, including the comparative performance of cancer-specific PBMs versus generic PBMs, measurement of outcomes beyond health-related QoL, and increased use of discrete choice experiments to elicit preferences. Recommendations and considerations are provided to guide the choice of method for cancer research. EXPERT OPINION: We foresee continued adoption of the QLU-C10D and FACT-8D in cancer clinical trials given the extensive use of the EORTC QLQ-C30 and FACT-G in cancer research. While these cancer-specific PBMs offer the convenience of eliciting utility values without needing a standalone PBM, researchers should consider potential limitations if they intend to substitute them for generic PBMs. As the field advances, there is a greater need for consensus on the approach to selection and integration of various methods in cancer clinical trials.
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Microglia are critical innate immune cells of the brain. In vivo targeting of microglia using gene-delivery systems is crucial for studying brain physiology and developing gene therapies for neurodegenerative diseases and other brain disorders such as NeuroAIDS. Historically, microglia have been extremely resistant to transduction by viral vectors, including adeno-associated virus (AAV) vectors. Recently, there has been some progress demonstrating the feasibility and potential of using AAV to transduce microglia after direct intraparenchymal vector injection. Data suggests that combining specific AAV capsids with microglia-specific gene expression cassettes to reduce neuron off-targeting will be key. However, no groups have developed AAV capsids for microglia transduction after intracerebroventricular (ICV) injection. The ICV route of administration has advantages such as increased brain biodistribution while avoiding issues related to systemic injection. Here, we performed an in vivo selection using an AAV peptide display library that enables recovery of capsids that mediate transgene expression in microglia. Using this approach, we identified a capsid, MC5, which mediated enhanced transduction of microglia after ICV injection compared to AAV9. Furthermore, MC5 enhanced both the efficiency (85%) and specificity (93%) of transduction compared to a recently described evolved AAV9 capsid for microglia targeting after direct injection into the brain parenchyma. Exploration of the use of MC5 in a mouse models of Alzheimer's disease revealed transduced microglia surrounding and within plaques. Overall, our results demonstrate that the MC5 capsid is a useful gene transfer tool to target microglia in vivo by direct and ICV routes of administration.
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Moderate- to high-impact exercise improves bone mineral density (BMD) across the lifespan, but its effects on bone structure, which predicts fracture independent of areal BMD, are unclear. This systematic review and meta-analysis investigated effects of impact exercise on volumetric BMD (vBMD) and bone structure. Four databases (PubMed, Embase, SPORTDiscus, Web of Science) were searched up to March 2022 for randomized controlled trials (RCTs) investigating the effects of impact exercise, with ground reaction forces equal to or greater than running, compared with sham or habitual activity, on bone vBMD and structure. Bone variables were measured by quantitative computed tomography or magnetic resonance imaging at the tibia, radius, lumbar spine, and femur. Percentage changes in bone variables were compared among groups using mean differences (MD) and 95% confidence intervals (CI) calculated via random effects meta-analyses. Subgroup analyses were performed in children/adolescents (<18 years), adults (18-50 years), postmenopausal women, and older men. Twenty-eight RCTs (n = 2985) were included. Across all studies, impact exercise improved trabecular vBMD at the distal tibia (MD = 0.54% [95% CI 0.17, 0.90%]), total vBMD at the proximal femur (3.11% [1.07, 5.14%]), and cortical thickness at the mid/proximal radius (1.78% [0.21, 3.36%]). There was no effect on vBMD and bone structure at the distal radius, femoral shaft, or lumbar spine across all studies or in any subgroup. In adults, impact exercise decreased mid/proximal tibia cortical vBMD (-0.20% [-0.24, -0.15%]). In postmenopausal women, impact exercise improved distal tibia trabecular vBMD (0.79% [0.32, 1.25%]). There was no effect on bone parameters in children/adolescents in overall analyses, and there were insufficient studies in older men to perform meta-analyses. Impact exercise may have beneficial effects on bone structure and vBMD at various skeletal sites, but additional high-quality RCTs in different age and sex subgroups are needed to identify optimal exercise protocols for improving bone health across the lifespan. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
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Densidade Óssea , Longevidade , Adulto , Masculino , Feminino , Adolescente , Criança , Humanos , Idoso , Ensaios Clínicos Controlados Aleatórios como Assunto , Exercício Físico , Tíbia/diagnóstico por imagem , Tíbia/patologia , Vértebras Lombares , Minerais , Rádio (Anatomia)/patologiaRESUMO
Although suboptimal bone health has been reported in children and adolescents with low motor competence (LMC), it is not known whether such deficits are present at the time of peak bone mass. We examined the impact of LMC on bone mineral density (BMD) in 1043 participants (484 females) from the Raine Cohort Study. Participants had motor competence assessed using the McCarron Assessment of Neuromuscular Development at 10, 14, and 17 years, and a whole-body dual-energy X-ray absorptiometry (DXA) scan at 20 years. Bone loading from physical activity was estimated from the International Physical Activity Questionnaire at the age of 17 years. The association between LMC and BMD was determined using general linear models that controlled for sex, age, body mass index, vitamin D status, and prior bone loading. Results indicated LMC status (present in 29.6% males and 21.9% females) was associated with a 1.8% to 2.6% decrease in BMD at all load-bearing bone sites. Assessment by sex showed that the association was mainly in males. Osteogenic potential of physical activity was associated with increased BMD dependent on sex and LMC status, with males with LMC showing a reduced effect from increasing bone loading. As such, although engagement in osteogenic physical activity is associated with BMD, other factors involved in physical activity, eg, diversity, movement quality, may also contribute to BMD differences based upon LMC status. The finding of lower peak bone mass for individuals with LMC may reflect a higher risk of osteoporosis, especially for males; however, further research is required. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
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Densidade Óssea , Osteoporose , Masculino , Criança , Adolescente , Feminino , Humanos , Adulto Jovem , Estudos de Coortes , Osteoporose/diagnóstico por imagem , Absorciometria de Fóton , Osso e Ossos/diagnóstico por imagemRESUMO
Systemic administration of adeno-associated virus (AAV) vectors for spinal cord gene therapy has challenges including toxicity at high doses and pre-existing immunity that reduces efficacy. Intrathecal delivery of AAV vectors into the cerebral spinal fluid (CSF) can avoid many of the issues of systemic delivery, although achieving broad distribution of the vector and transgene expression throughout the spinal cord is challenging and vector entry to the periphery occurs, sometimes initiating hepatotoxicity. Here we performed two rounds of in vivo biopanning in non-human primates (NHPs) with an AAV9 peptide display library injected intrathecally and performed insert sequencing on DNA isolated from either whole tissue (conventional selection), isolated nuclei, or nuclei from transgene-expressing cells. A subsequent barcoded pool of candidates and AAV9 was compared at the DNA (biodistribution) and RNA (expression) level in spinal cord and liver of intrathecally injected NHPs. Most of the candidates displayed enhanced biodistribution compared to AAV9 at all levels of spinal cord ranging from 2 to 265-fold. Nuclear isolation or expression-based selection yielded 4 of 7 candidate capsids with enhanced transgene expression in spinal cord (up to 2.4-fold), while no capsid obtained by conventional selection achieved that level. Furthermore, several capsids displayed lower biodistribution to the liver of up to 1,250-fold, compared to AAV9, providing a remarkable on target/off target biodistribution ratio. These capsids may have potential for gene therapy programs directed at the spinal cord and the selection method described here should be useful in clinically relevant large animal models.
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PURPOSE: To investigate associations between body mass index (BMI), body fat percentage, and components of sarcopenia (muscle mass and muscle strength/power), with bone microarchitecture measured by high-resolution peripheral computed tomography (HR-pQCT) in older adults with obesity. METHODS: Seventy-four adults aged ≥ 55 years with body fat percentage ≥ 30 % (men) or ≥40 % (women) were included. Fat mass, lean mass and total hip, femoral neck, and lumbar spine areal bone mineral density (aBMD) were measured by dual-energy X-ray absorptiometry. Appendicular lean mass (ALM) was calculated as the sum of lean mass in the upper- and lower-limbs. BMI was calculated and participants completed physical function assessments including stair climb power test. Distal tibial bone microarchitecture was assessed using HR-pQCT. Linear regression (ß-coefficients and 95 % confidence intervals) analyses were performed with adjustment for confounders including age, sex, smoking status, vitamin D and self-reported moderate to vigorous physical activity. RESULTS: BMI and ALM/height2 were both positively associated with total hip, femoral neck and lumbar spine aBMD and trabecular bone volume fraction after adjusting for confounders (all p < 0.05). Body fat percentage was not associated with aBMD or any trabecular bone parameters but was negatively associated with cortical area (p < 0.05). Stair climb power (indicating better performance) was positively associated with cortical area and negatively associated with bone failure load (both p < 0.05). CONCLUSION: Higher BMI, ALM/height2 and muscle power were associated with more favourable bone microarchitecture, but higher body fat percentage was negatively associated with cortical bone area. These findings suggest that high BMI may be protective for fractures and that this might be attributable to higher muscle mass and/or forces, while higher relative body fat is not associated with better bone health in older adults with obesity.