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1.
Osteoporos Int ; 35(2): 285-291, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37864596

RESUMO

To understand whether the bone loss which occurs after vertical sleeve gastrectomy increases the risk of fracture, we used an engineering model to estimate risk in participants before and after surgery. We found that estimated risk decreased 1 year after surgery and remained lower, though had rebounded, at year 2. PURPOSE: Vertical sleeve gastrectomy (VSG) improves metabolic health in young people with obesity but is accompanied by substantial loss of bone mass and estimated bone strength. We thus estimated fracture risk following VSG using the load-to-strength ratio (LSR), which integrates bone strength estimates with the predicted force of a fall. METHODS: Prospective 2-year study of youth ages 13-24 years with obesity undergoing VSG (n = 24) or lifestyle therapy (n = 34). We performed high-resolution peripheral quantitative computed tomography of the distal radius and microfinite element analysis to estimate bone strength and calculated LSR. RESULTS: VSG participants lost 26.4 ± 8.1% weight at year 1 (p < 0.001), which was sustained at year 2, while control participants gained weight at year 2 (4.5 ± 8.3%, p = 0.009). The predicted impact force decreased at years 1 and 2 following VSG (p < 0.001) but increased at year 2 among controls (p = 0.011). Estimated bone strength was unchanged at year 1 but decreased (p < 0.001) at year 2 following VSG, while bone strength did not change in controls. At year 1, the LSR decreased among VSG participants (p < 0.001), implying a lower risk of fracture. At year 2, the LSR was lower than baseline (p < 0.001), but higher compared to year 1 (p = 0.001). LSR did not change in the control group. CONCLUSIONS: Short-term estimated fracture risk at the radius following VSG decreases. However, ongoing bone loss despite stable weight between years 1 and 2 leads to a concerning rise in estimated fracture risk. Longer follow-up will be critical to evaluate the trajectory of fracture risk. (ClinicalTrials.gov NCT02557438, registered 9/23/2015).


Assuntos
Fraturas Ósseas , Fraturas do Punho , Traumatismos do Punho , Humanos , Adolescente , Adulto Jovem , Estudos Prospectivos , Redução de Peso , Obesidade , Gastrectomia
2.
Telemed J E Health ; 29(8): 1261-1265, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36656168

RESUMO

Introduction: The COVID-19 pandemic has resulted in increased use of telemedicine. There are limited data on patient experience with telemedicine in adults with congenital heart disease (ACHD). We hypothesized that due to their complex medical history, ACHD would prefer in-person clinic visits over telemedicine. Methods: We conducted a nurse-administered telephone survey based on Agency for Healthcare Research and Quality recommendations to assess patient experience after ACHD telemedicine visits in the early part of the pandemic from March 2020 to June 2020. Results: Of 216 ACHD who had telemedicine visits, 136 (63%) agreed to participate in the survey. Mean age was 45 ± 18 years, majority (65%) being video encounters. Most (98%) patients expressed that the telemedicine visit was successful in addressing their health care needs. Only 21 (15%) patients reported technical issues. Most patients (76%) preferred telemedicine given testing was provided separately, 25 (18%) preferred in-person clinic visits, and 8 (6%) had no preference. Of the 25 patients over 65 years, 19 (76%) would choose telemedicine over the in-person clinic, and only 1 patient reported technical difficulties. Conclusion: ACHD reported a positive experience with telemedicine. Technical limitations were infrequent even among the elderly. The majority of patients felt that their health care needs were addressed and would consider telemedicine over clinic visits. These data are important as payors move away from supporting telemedicine and hospitals restructure, with and without ongoing COVID-19 concerns.


Assuntos
COVID-19 , Cardiopatias Congênitas , Telemedicina , Adulto , Humanos , Idoso , Pessoa de Meia-Idade , COVID-19/epidemiologia , Pandemias , Satisfação do Paciente , Instituições de Assistência Ambulatorial , Cardiopatias Congênitas/terapia , Avaliação de Resultados da Assistência ao Paciente
4.
Artigo em Inglês | MEDLINE | ID: mdl-31767721

RESUMO

N4-Hydroxycytidine (NHC) is an antiviral ribonucleoside analog that acts as a competitive alternative substrate for virally encoded RNA-dependent RNA polymerases. It exhibits measurable levels of cytotoxicity, with 50% cytotoxic concentration values ranging from 7.5 µM in CEM cells and up to >100 µM in other cell lines. The mitochondrial DNA-dependent RNA polymerase (POLRMT) has been shown to incorporate some nucleotide analogs into mitochondrial RNAs, resulting in substantial mitochondrial toxicity. NHC was tested in multiple assays intended to determine its potential to cause mitochondrial toxicity. NHC showed similar cytotoxicity in HepG2 cells incubated in a glucose-free and glucose-containing media, suggesting that NHC does not impair mitochondrial function in this cell line based on the Crabtree effect. We demonstrate that the 5'-triphosphate of NHC can be used by POLRMT for incorporation into nascent RNA chain but does not cause immediate chain termination. In PC-3 cells treated with NHC, the 50% inhibitory concentrations of mitochondrial protein expression inhibition were 2.7-fold lower than those for nuclear-encoded protein expression, but this effect did not result in selective mitochondrial toxicity. A 14-day incubation of HepG2 cells with NHC had no effect on mitochondrial DNA copy number or extracellular lactate levels. In CEM cells treated with NHC at 10 µM, a slight decrease (by ∼20%) in mitochondrial DNA copy number and a corresponding slight increase in extracellular lactate levels were detected, but these effects were not enhanced by an increase in NHC treatment concentration. In summary, the results indicate that mitochondrial impairment by NHC is not the main contributor to the compound's observed cytotoxicity in these cell lines.


Assuntos
Citidina/análogos & derivados , Mitocôndrias Hepáticas/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Meios de Cultura , Citidina/farmacologia , DNA Mitocondrial/genética , RNA Polimerases Dirigidas por DNA/metabolismo , Dosagem de Genes , Células Hep G2 , Humanos , Ácido Láctico/metabolismo , Fosfatos/farmacologia
5.
Clin Endocrinol (Oxf) ; 91(1): 48-57, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30972777

RESUMO

OBJECTIVE: 25-hydroxyvitamin D (25(OH)D) is critical for bone mineralization and may prevent fractures. Understanding vitamin D deficiency trends in midlife women is particularly important given their concurrent menopausal changes that increase risk for fracture. We aimed to evaluate changes in mean 25(OH)D over time and their determinants in a racially, ethnically and socioeconomically diverse cohort of midlife women. DESIGN: A multi-centre prospective cohort study. PATIENTS: 1585 women ages 42-52 years at baseline. MEASUREMENTS: We measured serum 25(OH)D at 2 time points (1998-2000 and 2009-2011). Between-visit change was assessed in the whole cohort and in socioeconomic and demographic subgroups. Among those with vitamin D deficiency (25(OH)D <30 nmol/L) at baseline, we evaluated determinants of persistent deficiency at follow-up. RESULTS: Mean 25(OH)D increased from 53.8 to 70.0 nmol/L (P < 0.001), and the prevalence of deficiency decreased from 20.4% to 9.7% (P < 0.001). While baseline 25(OH)D differed among subgroups, the changes in 25(OH)D were similar among groups. The proportion of women reporting dietary supplement use increased from 40.8% to 67.1% (P < 0.001), and the increase in 25(OH)D was significantly higher in supplement users. Among women with vitamin D deficiency at baseline, White women and supplement users were less likely to remain deficient at follow-up. CONCLUSIONS: Among midlife women, temporal increases in 25(OH)D concentrations are driven largely by increases in supplement use. The proportion of women with 25(OH)D <30 nmol/L and thus at high risk for skeletal consequences remains substantial. Targeted screening for vitamin D deficiency in populations at risk for fragility fracture may be advisable.


Assuntos
Vitamina D/análogos & derivados , Adulto , Suplementos Nutricionais , Feminino , Humanos , Estudos Longitudinais , Menopausa , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores Socioeconômicos , Vitamina D/sangue , Vitamina D/uso terapêutico , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/tratamento farmacológico , Saúde da Mulher
6.
Artigo em Inglês | MEDLINE | ID: mdl-29891600

RESUMO

Morbidity and mortality resulting from influenza-like disease are a threat, especially for older adults. To improve case management, next-generation broad-spectrum antiviral therapeutics that are efficacious against major drivers of influenza-like disease, including influenza viruses and respiratory syncytial virus (RSV), are urgently needed. Using a dual-pathogen high-throughput screening protocol for influenza A virus (IAV) and RSV inhibitors, we have identified N4-hydroxycytidine (NHC) as a potent inhibitor of RSV, influenza B viruses, and IAVs of human, avian, and swine origins. Biochemical in vitro polymerase assays and viral RNA sequencing revealed that the ribonucleotide analog is incorporated into nascent viral RNAs in place of cytidine, increasing the frequency of viral mutagenesis. Viral passaging in cell culture in the presence of an inhibitor did not induce robust resistance. Pharmacokinetic profiling demonstrated dose-dependent oral bioavailability of 36 to 56%, sustained levels of the active 5'-triphosphate anabolite in primary human airway cells and mouse lung tissue, and good tolerability after extended dosing at 800 mg/kg of body weight/day. The compound was orally efficacious against RSV and both seasonal and highly pathogenic avian IAVs in mouse models, reducing lung virus loads and alleviating disease biomarkers. Oral dosing reduced IAV burdens in a guinea pig transmission model and suppressed virus spread to uninfected contact animals through direct transmission. Based on its broad-spectrum efficacy and pharmacokinetic properties, NHC is a promising candidate for future clinical development as a treatment option for influenza-like diseases.


Assuntos
Antivirais/farmacologia , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Animais , Células Cultivadas , Cobaias , Humanos , Vírus da Influenza A/efeitos dos fármacos , Vírus da Influenza A/genética , Vírus da Influenza B/efeitos dos fármacos , Vírus da Influenza B/genética , Camundongos , RNA Viral/genética , Vírus Sincicial Respiratório Humano/genética , Vírus Sinciciais Respiratórios/efeitos dos fármacos , Vírus Sinciciais Respiratórios/genética
9.
Radiographics ; 36(6): 1871-1887, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27726750

RESUMO

Metabolic bone diseases are a diverse group of diseases that result in abnormalities of (a) bone mass, (b) structure mineral homeostasis, (c) bone turnover, or (d) growth. Osteoporosis, the most common metabolic bone disease, results in generalized loss of bone mass and deterioration in the bone microarchitecture. Impaired chondrocyte development and failure to mineralize growth plate cartilage in rickets lead to widened growth plates and frayed metaphyses at sites of greatest growth. Osteomalacia is the result of impaired mineralization of newly formed osteoid, which leads to characteristic Looser zones. Hypophosphatasia is a congenital condition of impaired bone mineralization with wide phenotypic variability. Findings of hyperparathyroidism are the result of bone resorption, most often manifesting as subperiosteal resorption in the hand. Renal osteodystrophy is the collection of skeletal findings observed in patients with chronic renal failure and associated secondary hyperparathyroidism and can include osteopenia, osteosclerosis, and "rugger jersey spine." Hypoparathyroidism is most commonly due to iatrogenic injury, and radiographic findings of hypoparathyroidism reflect an overall increase in bone mass. Thyroid hormone regulates endochondral bone formation; and congenital hypothyroidism, when untreated, leads to delayed bone age and absent, irregular, or fragmented distal femoral and proximal tibial epiphyses. Soft-tissue proliferation of thyroid acropachy is most often observed in the hands and feet. The findings of acromegaly are due to excess growth hormone secretion and therefore proliferation of the bones and soft tissues. Vitamin C deficiency, or scurvy, impairs posttranslational collagen modification, leading to subperiosteal hemorrhage and fractures. ©RSNA, 2016.


Assuntos
Doenças Ósseas Metabólicas/diagnóstico por imagem , Osso e Ossos/diagnóstico por imagem , Erros de Diagnóstico/prevenção & controle , Tomografia Computadorizada por Raios X/métodos , Diagnóstico Diferencial , Medicina Baseada em Evidências , Humanos , Aumento da Imagem/métodos , Posicionamento do Paciente/métodos
10.
Chemphyschem ; 16(3): 528-31, 2015 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-25488257

RESUMO

Radicals, including hydroxyl, superoxide, and nitric oxide, play key signaling roles in vivo. Reaction of these free radicals with a spin trap affords more stable paramagnetic nitroxides, but concentrations in vivo still are so low that detection by electron paramagnetic resonance (EPR) is challenging. Three innovative enabling technologies have been combined to substantially improve sensitivity for imaging spin-trapped radicals at 250 MHz. 1) Spin-trapped adducts of BMPO have lifetimes that are long enough to make imaging by EPR at 250 MHz feasible. 2) The signal-to-noise ratio of rapid-scan EPR is substantially higher than for conventional continuous-wave EPR. 3) An improved algorithm permits image reconstruction with a spectral dimension that encompasses the full 50 G spectrum of the BMPO-OH spin adduct without requiring the wide sweeps that would be needed for filtered backprojection. A 2D spectral-spatial image is shown for a phantom containing ca. 5 µM BMPO-OH.


Assuntos
Radical Hidroxila/química , Detecção de Spin , Óxidos N-Cíclicos/química , Espectroscopia de Ressonância de Spin Eletrônica
11.
J Chem Phys ; 141(23): 234306, 2014 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-25527934

RESUMO

Collisional energy transfer between vibrational ground state CO2 and highly vibrationally excited monofluorobenzene (MFB) was studied using narrow bandwidth (0.0003 cm(-1)) IR diode laser absorption spectroscopy. Highly vibrationally excited MFB with E' = ∼41,000 cm(-1) was prepared by 248 nm UV excitation followed by rapid radiationless internal conversion to the electronic ground state (S1→S0*). The amount of vibrational energy transferred from hot MFB into rotations and translations of CO2 via collisions was measured by probing the scattered CO2 using the IR diode laser. The absolute state specific energy transfer rate constants and scattering probabilities for single collisions between hot MFB and CO2 were measured and used to determine the energy transfer probability distribution function, P(E,E'), in the large ΔE region. P(E,E') was then fit to a bi-exponential function and extrapolated to the low ΔE region. P(E,E') and the biexponential fit data were used to determine the partitioning between weak and strong collisions as well as investigate molecular properties responsible for large collisional energy transfer events. Fermi's Golden rule was used to model the shape of P(E,E') and identify which donor vibrational motions are primarily responsible for energy transfer. In general, the results suggest that low-frequency MFB vibrational modes are primarily responsible for strong collisions, and govern the shape and magnitude of P(E,E'). Where deviations from this general trend occur, vibrational modes with large negative anharmonicity constants are more efficient energy gateways than modes with similar frequency, while vibrational modes with large positive anharmonicity constants are less efficient at energy transfer than modes of similar frequency.

12.
Artigo em Inglês | MEDLINE | ID: mdl-39056255

RESUMO

CONTEXT: Neuropathy and fracture are prevalent complications of type 1 diabetes (T1D). Although correlated in the clinical literature, it remains unknown whether neuropathy contributes to the initiation of bone loss at the earliest stages of disease. METHODS: We performed a single-center, cross-sectional study to quantify parameters of nerve and bone health in adolescent girls with T1D (n=21) and associated controls (n=12). Groups were well matched for age, height, strength, and physical activity. RESULTS: By HR-pQCT, participants with T1D had lower trabecular bone volume fraction at the distal radius (-14.6%, p-adj=0.095) and the tibia (-12.8%, p-adj=0.017) and decreased trabecular thickness (-8.3% radius, p-adj=0.007; -7.5% tibia, p-adj=0.034) after adjustment for body size. In the tibia only, cortical bone mineral density was increased by 8.6% (p-adj=0.024) and porosity was decreased by 52.9% with T1D (p-adj=0.012). There were no significant differences in bone density by DXA. Participants with T1D also had lower circulating levels of osteocalcin (-30%, p=0.057), and type I collagen cross-linked C-telopeptide (-36%, p=0.035), suggesting low bone formation and turnover in T1D. Based on the Michigan Neuropathy Screening Instrument, 9.5% of those with T1D had clinical evidence of diabetic peripheral neuropathy. However, consideration of neuropathy status failed to explain the widespread T1D-associated changes in bone. CONCLUSION: Our study defines early deficits in trabecular bone microarchitecture, decreased cortical porosity in the tibia, and suppression of biomarkers of bone turnover in adolescent girls with T1D, prior to the onset of symptomatic peripheral neuropathy. These findings inform our understanding of the rapid progression of skeletal disease in young girls with T1D and suggests that early detection and management strategies may help to prevent fracture and related co-morbidities later in life.

13.
Orphanet J Rare Dis ; 19(1): 164, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38637809

RESUMO

BACKGROUND: Hypoparathyroidism (HP) is a rare endocrine disease commonly caused by the removal or damage of parathyroid glands during surgery and resulting in transient (tHP) or chronic (cHP) disease. cHP is associated with multiple complications and comorbid conditions; however, the economic burden has not been well characterized. The objective of this study was to evaluate the healthcare resource utilization (HCRU) and costs associated with post-surgical cHP, using tHP as a reference. METHODS: This analysis of a US claims database included patients with both an insurance claim for HP and thyroid/neck surgery between October 2014 and December 2019. cHP was defined as an HP claim ≥ 6 months following surgery and tHP was defined as only one HP claim < 6 months following surgery. The cHP index date was the first HP diagnosis claim following their qualifying surgery claim, whereas the tHP index date was the last HP diagnosis claim following the qualifying surgery claim. Patients were continuously enrolled at least 1 year pre- and post-index. Patients' demographic and clinical characteristics, all-cause HCRU, and costs were descriptively analyzed. Total all-cause costs were calculated as the sum of payments for hospitalizations, emergency department, office/clinic visits, and pharmacy. RESULTS: A total of 1,406 cHP and 773 tHP patients met inclusion criteria. The average age (52.1 years cHP, 53.5 years tHP) and representation of females (83.2% cHP, 81.2% tHP) were similar for both groups. Neck dissection surgery was more prevalent in cHP patients (23.6%) than tHP patients (5.3%). During the 1-2 year follow-up period, cHP patients had a higher prevalence of inpatient admissions (17.4%), and emergency visits (26.0%) than the reference group -tHP patients (14.4% and 21.4% respectively). Among those with a hospitalization, the average number of hospitalizations was 1.5-fold higher for cHP patients. cHP patients also saw more specialists, including endocrinologists (28.7% cHP, 15.8% tHP), cardiologists (16.7% cHP, 9.7% tHP), and nephrologists (4.6% cHP, 3.3% tHP). CONCLUSION: This study demonstrates the increased healthcare burden of cHP on the healthcare system in contrast to patients with tHP. Effective treatment options are needed to minimize the additional resources utilized by patients whose HP becomes chronic.


Assuntos
Hipoparatireoidismo , Seguro , Feminino , Humanos , Estados Unidos , Pessoa de Meia-Idade , Estresse Financeiro , Estudos Retrospectivos , Atenção à Saúde , Hipoparatireoidismo/epidemiologia , Custos de Cuidados de Saúde
14.
J Clin Endocrinol Metab ; 109(8): 1961-1974, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38828942

RESUMO

CONTEXT: Low vitamin D status is common and is associated with various common medical conditions. OBJECTIVE: To support the development of the Endocrine Society's Clinical Practice Guideline on Vitamin D for the Prevention of Disease. METHODS: We searched multiple databases for studies that addressed 14 clinical questions prioritized by the guideline panel. Of the 14 questions, 10 clinical questions assessed the effect of vitamin D vs no vitamin D in the general population throughout the lifespan, during pregnancy, and in adults with prediabetes; 1 question assessed dosing; and 3 questions addressed screening with serum 25-hydroxyvitamin D (25[OH]D). The Grading of Recommendations Assessment, Development and Evaluation approach was used to assess certainty of evidence. RESULTS: Electronic searches yielded 37 007 citations, from which we included 151 studies. In children and adolescents, low-certainty evidence suggested reduction in respiratory tract infections with empiric vitamin D. There was no significant effect on select outcomes in healthy adults aged 19 to 74 years with variable certainty of evidence. There was a very small reduction in mortality among adults older than 75 years with high certainty of evidence. In pregnant women, low-certainty evidence suggested possible benefit on various maternal, fetal, and neonatal outcomes. In adults with prediabetes, moderate certainty of evidence suggested reduction in the rate of progression to diabetes. Administration of high-dose intermittent vitamin D may increase falls, compared to lower-dose daily dosing. We did not identify trials on the benefits and harms of screening with serum 25(OH)D. CONCLUSION: The evidence summarized in this systematic review addresses the benefits and harms of vitamin D for the prevention of disease. The guideline panel considered additional information about individuals' and providers' values and preferences and other important decisional and contextual factors to develop clinical recommendations.


Assuntos
Guias de Prática Clínica como Assunto , Deficiência de Vitamina D , Vitamina D , Humanos , Vitamina D/sangue , Vitamina D/análogos & derivados , Vitamina D/administração & dosagem , Vitamina D/uso terapêutico , Gravidez , Feminino , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/tratamento farmacológico , Deficiência de Vitamina D/prevenção & controle , Adulto , Sociedades Médicas/normas , Endocrinologia/normas , Endocrinologia/métodos , Suplementos Nutricionais , Idoso , Estado Pré-Diabético/sangue , Estado Pré-Diabético/tratamento farmacológico , Estado Pré-Diabético/diagnóstico , Vitaminas/uso terapêutico , Vitaminas/administração & dosagem
15.
J Clin Endocrinol Metab ; 109(8): 1907-1947, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38828931

RESUMO

BACKGROUND: Numerous studies demonstrate associations between serum concentrations of 25-hydroxyvitamin D (25[OH]D) and a variety of common disorders, including musculoskeletal, metabolic, cardiovascular, malignant, autoimmune, and infectious diseases. Although a causal link between serum 25(OH)D concentrations and many disorders has not been clearly established, these associations have led to widespread supplementation with vitamin D and increased laboratory testing for 25(OH)D in the general population. The benefit-risk ratio of this increase in vitamin D use is not clear, and the optimal vitamin D intake and the role of testing for 25(OH)D for disease prevention remain uncertain. OBJECTIVE: To develop clinical guidelines for the use of vitamin D (cholecalciferol [vitamin D3] or ergocalciferol [vitamin D2]) to lower the risk of disease in individuals without established indications for vitamin D treatment or 25(OH)D testing. METHODS: A multidisciplinary panel of clinical experts, along with experts in guideline methodology and systematic literature review, identified and prioritized 14 clinically relevant questions related to the use of vitamin D and 25(OH)D testing to lower the risk of disease. The panel prioritized randomized placebo-controlled trials in general populations (without an established indication for vitamin D treatment or 25[OH]D testing), evaluating the effects of empiric vitamin D administration throughout the lifespan, as well as in select conditions (pregnancy and prediabetes). The panel defined "empiric supplementation" as vitamin D intake that (a) exceeds the Dietary Reference Intakes (DRI) and (b) is implemented without testing for 25(OH)D. Systematic reviews queried electronic databases for publications related to these 14 clinical questions. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology was used to assess the certainty of evidence and guide recommendations. The approach incorporated perspectives from a patient representative and considered patient values, costs and resources required, acceptability and feasibility, and impact on health equity of the proposed recommendations. The process to develop this clinical guideline did not use a risk assessment framework and was not designed to replace current DRI for vitamin D. RESULTS: The panel suggests empiric vitamin D supplementation for children and adolescents aged 1 to 18 years to prevent nutritional rickets and because of its potential to lower the risk of respiratory tract infections; for those aged 75 years and older because of its potential to lower the risk of mortality; for those who are pregnant because of its potential to lower the risk of preeclampsia, intra-uterine mortality, preterm birth, small-for-gestational-age birth, and neonatal mortality; and for those with high-risk prediabetes because of its potential to reduce progression to diabetes. Because the vitamin D doses in the included clinical trials varied considerably and many trial participants were allowed to continue their own vitamin D-containing supplements, the optimal doses for empiric vitamin D supplementation remain unclear for the populations considered. For nonpregnant people older than 50 years for whom vitamin D is indicated, the panel suggests supplementation via daily administration of vitamin D, rather than intermittent use of high doses. The panel suggests against empiric vitamin D supplementation above the current DRI to lower the risk of disease in healthy adults younger than 75 years. No clinical trial evidence was found to support routine screening for 25(OH)D in the general population, nor in those with obesity or dark complexion, and there was no clear evidence defining the optimal target level of 25(OH)D required for disease prevention in the populations considered; thus, the panel suggests against routine 25(OH)D testing in all populations considered. The panel judged that, in most situations, empiric vitamin D supplementation is inexpensive, feasible, acceptable to both healthy individuals and health care professionals, and has no negative effect on health equity. CONCLUSION: The panel suggests empiric vitamin D for those aged 1 to 18 years and adults over 75 years of age, those who are pregnant, and those with high-risk prediabetes. Due to the scarcity of natural food sources rich in vitamin D, empiric supplementation can be achieved through a combination of fortified foods and supplements that contain vitamin D. Based on the absence of supportive clinical trial evidence, the panel suggests against routine 25(OH)D testing in the absence of established indications. These recommendations are not meant to replace the current DRIs for vitamin D, nor do they apply to people with established indications for vitamin D treatment or 25(OH)D testing. Further research is needed to determine optimal 25(OH)D levels for specific health benefits.


Assuntos
Suplementos Nutricionais , Deficiência de Vitamina D , Vitamina D , Humanos , Vitamina D/sangue , Vitamina D/uso terapêutico , Vitamina D/administração & dosagem , Vitamina D/análogos & derivados , Feminino , Deficiência de Vitamina D/prevenção & controle , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/tratamento farmacológico , Deficiência de Vitamina D/diagnóstico , Gravidez , Criança , Sociedades Médicas/normas , Adolescente , Adulto , Endocrinologia/normas , Endocrinologia/métodos , Endocrinologia/organização & administração , Masculino , Vitaminas/uso terapêutico , Vitaminas/administração & dosagem
16.
Biophys J ; 105(2): 338-42, 2013 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-23870255

RESUMO

The short lifetime of superoxide and the low rates of formation expected in vivo make detection by standard continuous wave (CW) electron paramagnetic resonance (EPR) challenging. The new rapid-scan EPR method offers improved sensitivity for these types of samples. In rapid-scan EPR, the magnetic field is scanned through resonance in a time that is short relative to electron spin relaxation times, and data are processed to obtain the absorption spectrum. To validate the application of rapid-scan EPR to spin trapping, superoxide was generated by the reaction of xanthine oxidase and hypoxanthine with rates of 0.1-6.0 µM/min and trapped with 5-tert-butoxycarbonyl-5-methyl-1-pyrroline-N-oxide (BMPO). Spin trapping with BMPO to form the BMPO-OOH adduct converts the very short-lived superoxide radical into a more stable spin adduct. There is good agreement between the hyperfine splitting parameters obtained for BMPO-OOH by CW and rapid-scan EPR. For the same signal acquisition time, the signal/noise ratio is >40 times higher for rapid-scan than for CW EPR. Rapid-scan EPR can detect superoxide produced by Enterococcus faecalis at rates that are too low for detection by CW EPR.


Assuntos
Limite de Detecção , Detecção de Spin/métodos , Superóxidos/análise , Espectroscopia de Ressonância de Spin Eletrônica/métodos , Enterococcus faecalis/química , Hipoxantina/química , Polipropilenos/química , Superóxidos/química , Xantina Oxidase/química
17.
Biotechnol Bioeng ; 110(7): 1936-44, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23359480

RESUMO

Electron paramagnetic resonance spectroscopy is used to observe hydroxyl radicals produced by an atmospheric pressure nonthermal plasma device at distances greater than 1 m from the discharge. The plasma device is an indirect treatment setup with closed loop airflow and hydrogen peroxide additives that is effective in deactivating bacteria on time scales of seconds. The generation of the detected hydroxyl radicals is shown to occur in secondary chemical processes near the point of delivery of the plasma treated air stream. The production of hydroxyl radicals is correlated with humidity of the air stream and ability to lyse bacterial membranes. The overall mechanisms of bacteria inactivation are found to be a combinatorial effect of effluent species. The results indicate the feasibility of selective plasma induced free radical delivery for biomedical applications even in the case of short-lived species like the hydroxyl radical.


Assuntos
Bactérias/efeitos dos fármacos , Fenômenos Químicos , Desinfetantes/farmacologia , Radical Hidroxila/farmacologia , Gases em Plasma/química , Viabilidade Microbiana/efeitos dos fármacos
18.
JBMR Plus ; 7(11): e10813, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38025039

RESUMO

Type 1 diabetes (T1D) confers an increased risk of fracture and is associated with lower bone mineral density (BMD) and altered microarchitecture compared with controls. Adequate calcium (Ca) intake promotes bone mineralization, thereby increasing BMD. The objective of this analysis was to evaluate the associations of total daily Ca intake with bone outcomes among youth with T1D. This was a cross-sectional analysis of girls ages 10-16 years with (n = 62) and without (n = 60) T1D. We measured Ca intake with a validated food-frequency questionnaire and BMD, microarchitecture, and strength estimates with dual-energy X-ray absorptiometry and high-resolution peripheral quantitative computed tomography. Total daily Ca intake did not differ between groups (950 ± 488 in T1D versus 862 ± 461 mg/d in controls, p = 0.306). Serum 25OHD was lower in T1D (26.3 ± 7.6 versus 32.6 ± 9.0 ng/mL, p = <0.001), and parathyroid hormone (PTH) was higher in T1D (38.9 ± 11 versus 33.4 ± 9.7 pg/mL, p = 0.004). Trabecular volumetric BMD and thickness at the tibia were lower in T1D (p = 0.013, p = 0.030). Ca intake correlated with trabecular BMD at the radius and tibia among T1D participants (ß = 0.27, p = 0.047, and ß = 0.28, p = 0.027, ß = 0.28, respectively) but not among controls (pinteraction = 0.009 at the radius, pinteraction = 0.010 at the tibia). Similarly, Ca intake was associated with estimated failure load at the tibia in T1D but not control participants (p = 0.038, ß = 0.18; pinteraction = 0.051). We observed the expected negative association of Ca intake with parathyroid hormone in controls (p = 0.022, ß = -0.29) but not in T1D participants (pinteraction = 0.022). Average glycemia as measured by hemoglobin A1c did not influence the relationship of Ca and PTH among participants with T1D (pinteraction = 0.138). These data suggest that youth with T1D may be particularly vulnerable to dietary Ca insufficiency. Increasing Ca intake may be an effective strategy to optimize bone health in this population. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

19.
Eur J Endocrinol ; 189(3): 346-354, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37633255

RESUMO

OBJECTIVE: To determine mechanisms contributing to impaired bone health in youth 24 months following sleeve gastrectomy (SG). DESIGN: Twenty-four-month longitudinal observational study. METHODS: Participants included 23 youth undergoing SG and 30 non-surgical controls (NS) 13-25 years old with moderate-to-severe obesity. Subjects underwent fasting labs for bone turnover markers (N-terminal propeptide of type 1 procollagen, C-telopeptide (CTX)), sex hormones, sex hormone binding globulin (SHBG), and enteric peptides, DXA for areal bone mineral density (aBMD) and body composition, high-resolution peripheral quantitative CT for volumetric BMD (vBMD) at the distal radius and tibia, and microfinite element analysis for strength estimates. RESULTS: Groups did not differ for mean age or BMI z-scores. Over 24 months, compared to NS, SG had greater reductions in BMI z-scores, and spine, hip, and femoral neck aBMD Z-scores (P ≤ .012), greater increases in serum CTX and SHBG (P ≤ .039), and greater decreases in estrone and ghrelin (P ≤ .021). Among females, estrone and free androgen index (FAI) decreased (P ≤ .022) in SG vs NS groups. After controlling for age and sex, decreases in BMI and lean mass were associated with decreases in total hip and femoral neck aBMD Z-scores, and decreases in radial total and trabecular vBMD and failure load, and tibial total and trabecular vBMD. Among females, after controlling for age, decreases in estrone were associated with decreases in spine aBMD Z-scores and radial total and trabecular vBMD, and decrease in FAI with decreases in radial failure load. CONCLUSION: Reductions in BMI, lean mass, and sex steroids over 24 months post-SG are associated with bone loss and could be targeted for preventative or therapeutic interventions. Clinical trial registration number: The study is registered in ClinicalTrials.gov (NCT02557438).


Assuntos
Estrona , Coluna Vertebral , Feminino , Adolescente , Humanos , Adulto Jovem , Adulto , Densidade Óssea , Composição Corporal , Gastrectomia
20.
J Clin Endocrinol Metab ; 108(4): 847-857, 2023 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-36314507

RESUMO

CONTEXT: Vertical sleeve gastrectomy (VSG) is an increasingly common tool to achieve weight loss and improve metabolic health in adolescents and young adults with obesity, although it may adversely affect bone health. OBJECTIVE: This work aimed to evaluate the effect of VSG on bone health in youth. METHODS: An observational 2-year study was conducted at a tertiary care center of 66 patients aged 13 to 24 years with moderate-to-severe obesity meeting criteria for VSG. The patients underwent VSG (n = 30) or nonsurgical (n = 36) management per the decision of patient and clinical team. Main outcome measures included dual-energy x-ray absorptiometry (DXA) and high-resolution peripheral quantitative computed tomography (HRpQCT) measures of bone mineral density (BMD), geometry, and microarchitecture. RESULTS: VSG patients achieved 25.3 ± 2.0% weight loss at 2 years (P < .001) while control subjects gained 4.0 ± 2.0% (P = .026). Total hip BMD declined 8.5 ± 1.0% following VSG compared with 0.1 ± 1.0% gain in controls (P < .001), with similar results at the femoral neck (P < .001). Total volumetric BMD (vBMD) decreased both at the distal radius and tibia following VSG (P < .001) driven primarily by trabecular vBMD loss (P < .001). Two-year changes in cortical vBMD did not differ between groups, though cortical porosity decreased following VSG both at the radius and tibia (P = .048 and P < .001). Cortical thickness increased in controls but not in VSG (P = .022 and P = .002 for between-group comparisons at the radius and tibia, respectively). Following VSG, estimated failure load decreased at the radius and did not demonstrate the physiologic increases at the tibia observed in controls. CONCLUSION: VSG leads to progressive changes in bone health over 2 years, and may lead to increased skeletal fragility in adolescents and young adults.


Assuntos
Densidade Óssea , Osso e Ossos , Humanos , Adolescente , Adulto Jovem , Estudos Longitudinais , Densidade Óssea/fisiologia , Absorciometria de Fóton , Obesidade , Rádio (Anatomia)/diagnóstico por imagem , Rádio (Anatomia)/fisiologia , Tíbia/diagnóstico por imagem , Tíbia/fisiologia
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