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1.
Graefes Arch Clin Exp Ophthalmol ; 260(9): 2887-2895, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35389059

RESUMO

PURPOSE: To report the long-term refractive outcomes and complications of two scleral fixation techniques for secondary intraocular lenses (IOL). METHODS: Consecutive patients who underwent secondary IOL insertion at a tertiary care academic hospital using either modified glued ("glued") or flanged intrascleral haptic fixation (FISHF) techniques with over 12 months of follow-up were retrospectively reviewed. Pre- and postoperative corrected distance visual acuity (CDVA), postoperative complications, and refractive surprises were reported. RESULTS: Thirty-eight patients underwent "glued" fixation and 22 underwent FISHF, with mean follow-up times of 3.1 ± 0.5 and 2.0 ± 1.2 years, respectively. Aphakia secondary to trauma was the main surgical indication. MA50BM or MA60AC IOLs (Alcon Laboratories Inc., Fort Worth, TX) were implanted in 92% of "glued" patients, while CT Lucia 602 IOLs (Carl Zeiss Meditec Inc., Dublin, CA) were used in 96% of FISHF patients. Postoperative spherical equivalent significantly improved compared to preoperative values (p < 0.001). No significant difference in CDVA was seen between the two techniques. FISHF resulted in mean hyperopic surprises of + 0.81D and + 0.69D using the Holladay 2 and Barrett Universal II formulae, respectively, which was significantly greater than the "glued" patients. A higher rate of IOL dislocation was seen in the "glued" cohort (13%) compared to FISHF (0%). CONCLUSIONS: Retrospective long-term outcomes of patients with complex ocular comorbidities undergoing a modified "glued" technique demonstrated a higher rate of IOL dislocation but more predictable refractive outcomes compared to the FISHF technique. The FISHF technique resulted in a significant hyperopic shift using fourth-generation IOL calculators.


Assuntos
Lentes Intraoculares , Adesivos , Tecnologia Háptica , Humanos , Implante de Lente Intraocular , Complicações Pós-Operatórias , Estudos Retrospectivos , Esclera , Técnicas de Sutura
2.
Pediatr Res ; 83(3): 669-676, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29261645

RESUMO

BackgroundThe growth trajectories of common measurements, including estimated fetal weight (EFW), head circumference (HC), and abdominal circumference (AC), in fetuses with congenital heart disease (CHD) have not been described for different cardiac lesions. We hypothesized that (i) fetuses with CHD have differential growth in utero, and (ii) different categories of CHD demonstrate different in utero growth curves.MethodsWe performed a retrospective observational cohort study of pregnancies with known fetal CHD seen from January 2000 to June 2013. For analysis, the infants were divided into single ventricle (SV), biventricular conotruncal, d-transposition of great arteries (d-TGA), biventricular septal defects (SD; including atrial, ventricular, and atrioventricular SD), and all others (Other).ResultsA total of 194 newborns met inclusion criteria. There was significant differential growth of EFW in all CHD types, except d-TGA, starting with low z-scores before 25 weeks gestation, improving toward normal around 30-32 weeks gestation, and then again differential growth with advancing gestation. SV and SD groups had significant differential growth of HC starting early in gestation and linearly progressing negative z-scores with advancing gestation.ConclusionWe observed differences in the fetal growth curves throughout gestation for the major categories of CHD, including significant differential growth in even "simple" CHD, such as SD.


Assuntos
Desenvolvimento Fetal/fisiologia , Cardiopatias Congênitas/diagnóstico por imagem , Cardiopatias Congênitas/fisiopatologia , Cardiopatias/fisiopatologia , Antropometria , Feminino , Peso Fetal , Idade Gestacional , Cabeça/anatomia & histologia , Ventrículos do Coração/fisiopatologia , Humanos , Recém-Nascido , Masculino , Gravidez , Estudos Retrospectivos , Risco , Ultrassonografia Pré-Natal
4.
Am J Physiol Renal Physiol ; 308(5): F459-72, 2015 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-25537742

RESUMO

Kidney fibrosis is the final common pathway for virtually every type of chronic kidney disease and is a consequence of a prolonged healing response that follows tissue inflammation. Chronic kidney inflammation ultimately leads to progressive tissue injury and scarring/fibrosis. Several pathways have been implicated in the progression of kidney fibrosis. In the present study, we demonstrate that G protein-coupled chemokine (C-X-C motif) receptor (CXCR)4 was significantly upregulated after renal injury and that sustained activation of Cxcr4 expression augmented the fibrotic response. We demonstrate that after unilateral ureteral obstruction (UUO), both gene and protein expression of Cxcr4 were highly upregulated in tubular cells of the nephron. The increased Cxcr4 expression in tubules correlated with their increased dedifferentiated state, leading to increased mRNA expression of platelet-derived growth factor (PDGF)-α, transforming growth factor (TGF)-ß1, and concurrent loss of bone morphogenetic protein 7 (Bmp7). Ablation of tubular Cxcr4 attenuated UUO-mediated fibrotic responses, which correlated with a significant reduction in PDGF-α and TGF-ß1 levels and preservation of Bmp7 expression after UUO. Furthermore, Cxcr4(+) immune cells infiltrated the obstructed kidney and further upregulate their Cxcr4 expression. Genetic ablation of Cxcr4 from macrophages was protective against UUO-induced fibrosis. There was also reduced total kidney TGF-ß1, which correlated with reduced Smad activation and α-smooth muscle actin levels. We conclude that chronic high Cxcr4 expression in multiple effector cell types can contribute to the pathogenesis of renal fibrosis by altering their biological profile. This study uncovered a novel cross-talk between Cxcr4-TGF-ß1 and Bmp7 pathways and may provide novel targets for interrupting the progression of fibrosis.


Assuntos
Proteína Morfogenética Óssea 7/metabolismo , Rim/metabolismo , Nefroesclerose/etiologia , Receptores CXCR4/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Animais , Benzilaminas , Ciclamos , Fibrose , Compostos Heterocíclicos , Rim/imunologia , Rim/patologia , Ativação de Macrófagos , Masculino , Camundongos Endogâmicos C57BL , Nefroesclerose/metabolismo , Receptores CXCR4/antagonistas & inibidores , Regulação para Cima , Obstrução Ureteral
5.
Biomedicines ; 11(5)2023 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-37238939

RESUMO

Choroidal caverns (CCs) have been described in association with age-related macular degeneration and pachychoroid disease. However, it is unknown if caverns are found in patients with chronic non-infectious uveitis (NIU). Herein, we evaluated patients with NIU who had optical coherence tomography and indocyanine green angiography for CCs. Clinical and demographic characteristics were extracted from the chart review. Univariate and multivariate mixed-effects logistical models were used to assess the association between clinical and demographic factors and the presence of CCs. One hundred thirty-five patients (251 eyes) met the inclusion criteria: 1 eye had anterior uveitis, 5 had intermediate uveitis, 194 had posterior uveitis, and 51 had panuveitis. The prevalence of CCs was 10%. CCs were only observed in patients with posterior and panuveitis, with a prevalence of 10.8% and 7.8%, respectively. Multifocal choroiditis (MFC) was the type of uveitis where CCs were most frequently observed, with 40% of eyes with MFC having CCs. In addition, male sex (p = 0.024) was associated with CCs. There was no significant difference in the degree of intraocular inflammation or mean subfoveal choroidal thickness between CC+ and CC- eyes. This is the first study to describe CCs in uveitis. Overall, these findings suggest that caverns may be a sequela of structural and/or vascular perturbations in the choroid from uveitis.

6.
Eur J Obstet Gynecol Reprod Biol X ; 18: 100191, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37065675

RESUMO

Objective: To investigate the rise and clearance of newborn creatinine in perinatal asphyxia as an adjunct biomarker to support or refute allegations of acute intrapartum asphyxia. Study design: In this retrospective chart review, newborns > 35 weeks gestational age were evaluated from closed medicolegal cases of confirmed perinatal asphyxia and reviewed for causation. Data collected included newborn demographic data, patterns of hypoxic ischemic encephalopathy, brain magnetic resonance imaging, Apgar scores, cord and initial newborn blood gases, and serial newborn creatinine levels during the first 96 h of life. Newborn serum creatinine values were collected at 0-12, 13-24, 25-48, and 49-96 h. Newborn brain magnetic resonance imaging was used to define 3 patterns of asphyxial injury: acute profound, partial prolonged, or Both. Results: Two hundred and eleven cases of neonatal encephalopathy from multiple institutions were reviewed from 1987 to 2019 with only 76 cases having serial creatinine values during the first 96 h of life. A total of 187 creatinine values were collected. Partial prolonged and Both had significantly greater degree of metabolic acidosis in the first newborn arterial blood gas in comparison to acute profound. Acute profound and Both had significantly lower 5- and 10- minute Apgar scores in comparison to partial prolonged. Newborn creatinine values were stratified by asphyxial injury. Acute profound injury showed minimally elevated creatinine trends with rapid normalization. Partial prolonged and Both demonstrated higher creatinine trends with delayed normalization. Mean creatinine values were significantly different between the three types of asphyxial injuries within 13-24 h of life at the time when creatinine values peaked (p = 0.01). Conclusion: Serial newborn serum creatinine levels taken within the first 96 h of life can provide objective data of timing and duration of perinatal asphyxia.

7.
Asia Pac J Ophthalmol (Phila) ; 11(2): 140-148, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35533333

RESUMO

ABSTRACT: Alzheimer disease (AD) is a significant cause of morbidity and mortality worldwide, with limited treatment options and considerable diagnostic challenges. Identification and validation of retinal changes that correlate with clinicopathologic features of AD could provide a noninvasive method of screening and monitoring progression of disease, with notable implications for developing new therapies, particularly in its preclinical stages. Retinal biomarkers that have been studied to date include structural changes in neurosensory retinal layers, alterations in vascular architecture and function, and pathologic deposition of proteins within the retina, which have all demonstrated variable correlation with the presence of preclinical or clinical AD. Evolution of specialized retinal imaging modalities and advances in artificial intelligence hold great promise for future study in this burgeoning field. The current status of research in retinal biomarkers, and some of the challenges that will need to be addressed in future work, are reviewed herein.


Assuntos
Doença de Alzheimer , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/metabolismo , Inteligência Artificial , Biomarcadores , Humanos , Programas de Rastreamento , Retina
8.
Artigo em Inglês | MEDLINE | ID: mdl-36729812

RESUMO

PURPOSE: To report a case of giant intraoperative corneal bulla formation in a patient with a history of recent phacoemulsification with clear corneal incision that was managed with a bandage contact lens intraoperatively. METHODS: Retrospective case report with anterior segment optical coherence tomography (AS-OCT). RESULTS: A 77-year-old woman with history of recent complicated cataract surgery with retained lens fragments underwent pars plana vitrectomy (PPV) and scleral fixated intraocular lens placement. During PPV, a large corneal bulla formed at the site of the main corneal incision, confirmed with AS-OCT. A bandage contact lens with viscoelastic was used to overcome visualization challenges and safely proceed with the surgery. CONCLUSION: This is the first report of corneal bullae formation during PPV that is confirmed by AS-OCT and successfully managed with a bandage contact lens intraoperatively.

9.
Taiwan J Ophthalmol ; 11(2): 122-131, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34295617

RESUMO

The management of Fuchs' endothelial corneal dystrophy (FECD) has evolved rapidly since the introduction of endothelial keratoplasty (EK). In recent years, advances in our understanding of endothelial cell biology, in particular with respect to the regenerative capacity of endothelial cells, have opened the door to novel therapeutic options that stray from the traditional paradigm of allograft transplantation. We review the development of descemetorhexis without EK (DWEK) as a primary treatment for FECD and discuss the lessons learned to date about the mechanism of wound healing, surgical technique, patient selection, and refractive outcomes. Multiple randomized clinical trials are currently underway to evaluate the potential for pharmacological supplementation with rho-associated kinase inhibitors to increase the success rate of corneal clearance following DWEK. Biologic supplementation with intracameral endothelial cell injection and acellular Descemet's membrane transplantation are other avenues of adjuvant therapy. DWEK is a promising surgical option for management of a subset of FECD patients.

10.
Am J Ophthalmol ; 230: 134-142, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33945819

RESUMO

OBJECTIVE: To optimize the flanged belt-loop technique of scleral fixation through biomechanical testing and report clinical outcomes of resultant modifications. DESIGN: Experimental study. METHODS: The force to disinsert flanged polypropylene suture from human cadaveric sclera was assessed using a tensile testing machine and compared to the breaking strengths of 9-0 and 10-0 polypropylene. The effects of modifying suture gauge (5-0, 6-0, 7-0, or 8-0), amount of suture cauterized (0.5 or 1.0 mm), and sclerotomy size (27, 30, 32, 33 gauge) were investigated. Belt-loop intrascleral fixation using 6-0 and 7-0 polypropylene with 30 and 32 gauge needles, respectively, was performed in 4 patients. Main outcome measures were flanged suture disinsertion forces in cadaveric sclera. RESULTS: The average force to disinsert a flange created by melting 1.0 mm of 5-0, 6-0, 7-0, and 8-0 polypropylene suture from human cadaveric sclera via 27, 30, 32, and 33 gauge needle sclerotomies was 3.0 ± 0.5 N, 2.1 ± 0.3 N, 0.9 ± 0.2 N, and 0.4 ± 0.1 N, respectively. The disinsertion forces for flanges formed by melting 0.5 mm of the same gauges were 72%-79% lower (P < .001). In comparison, the breaking strengths of 9-0 and 10-0 polypropylene were 0.91 ± 0.4 N and 0.52 ± 0.03 N. Belt-loop fixation using 6-0 and 7-0 polypropylene with 30 and 32 gauge sclerotomies demonstrated good outcomes at 6 months. CONCLUSIONS: The flanged belt-loop technique is a biomechanically sound method of scleral fixation using 1.0 mm flanges of 5-0 to 7-0 polypropylene paired with 27, 30, and 32 gauge sclerotomies. In contrast, 8-0 polypropylene and 0.5 mm flanges of any suture gauge will likely be unstable with this technique.


Assuntos
Lentes Intraoculares , Esclera , Humanos , Implante de Lente Intraocular , Polipropilenos , Esclera/cirurgia , Técnicas de Sutura , Suturas
11.
Cornea ; 40(7): 926-929, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33252384

RESUMO

PURPOSE: To describe a case of new-onset benign paroxysmal positional vertigo (BPPV) after uncomplicated Descemet stripping automated endothelial keratoplasty. METHODS: Case report and review of literature. RESULTS: A 61-year-old woman with a history of steroid-induced glaucoma and penetrating keratoplasty for Fuchs endothelial dystrophy, and no history of BPPV or other vertigo, underwent Descemet stripping automated endothelial keratoplasty for penetrating keratoplasty graft failure. On the third postoperative day, she developed acute spinning vertigo, nausea, and headache on sitting up after 3 days of strict supine positioning. Her ophthalmic examination was benign, with no evidence of a pupillary block, and she was diagnosed by an otologist with BPPV. Her symptoms resolved after 1 week without further intervention. CONCLUSIONS: BPPV is a benign but rare complication of nonotologic surgery and has not been previously reported with ophthalmic surgery. The overlap in symptomatology between BPPV and other serious and potentially vision-threatening causes of postoperative nausea and headache, such as pupillary block glaucoma, makes this a relevant etiology to consider in the spectrum of postendothelial keratoplasty complications.


Assuntos
Vertigem Posicional Paroxística Benigna/etiologia , Ceratoplastia Endotelial com Remoção da Lâmina Limitante Posterior , Cefaleia/etiologia , Náusea/etiologia , Complicações Pós-Operatórias , Doença Aguda , Vertigem Posicional Paroxística Benigna/diagnóstico , Feminino , Rejeição de Enxerto/cirurgia , Cefaleia/diagnóstico , Humanos , Pessoa de Meia-Idade , Náusea/diagnóstico
12.
Am J Ophthalmol ; 227: 45-52, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33626366

RESUMO

PURPOSE: Flanged intrascleral haptic fixation (FISHF) is a useful method for securing intraocular lenses (IOLs) in eyes without capsular support. Biomechanical studies were conducted to support the use of this technique. DESIGN: Laboratory investigation. METHODS: Haptics of 3-piece IOLs were passed through cadaveric human sclera using 30- and 27-gauge needles. Flanges were created by melting 1.0 mm from the haptic ends using cautery. The forces required to remove the flanged haptic from the sclera and disinsert the haptic from the optic were measured using a mechanical tester and a custom-fabricated mount. RESULTS: The mean FISHF dislocation force using 30-gauge needles was greatest with the CT Lucia 602 (2.04 ± 0.24 newtons [N]) compared to the LI61AO (0.93 ± 0.41 N; P = .001), ZA9003 (0.70 ± 0.34 N; P = <.001), and MA60AC (0.27 ± 0.19 N; P <.001). Using 27-gauge needles with the CT Lucia resulted in a lower dislocation force (0.56 ± 0.36 N; P <.001). The FISHF dislocation force was correlated with the flange-to-needle diameter ratio (r = 0.975). The FISHF dislocation forces of the CT Lucia and LI61AO using 30-gauge needles were not significantly different from their haptic-optic disinsertion forces (P = .79 and .27, respectively). There were no differences in flange diameters between 1.0 mm and 2.0 mm haptic melt lengths across the IOLs (P = .15-.85). CONCLUSIONS: These data strongly support the biomechanical stability of FISHF with the polyvinylidene fluoride haptics of the CT Lucia using small diameter instruments for the creation of an intrascleral tunnel. 1.0 mm of haptic may be the optimal melt length.


Assuntos
Fenômenos Biomecânicos/fisiologia , Implante de Lente Intraocular/métodos , Lentes Intraoculares , Esclera/cirurgia , Humanos , Desenho de Prótese , Pseudofacia/fisiopatologia , Técnicas de Sutura , Doadores de Tecidos , Acuidade Visual/fisiologia
13.
Digit J Ophthalmol ; 27(1): 17-21, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33907533

RESUMO

Fish hook open-globe injuries (OGIs) are challenging to repair surgically because of the backward-projecting barb near the hook's point that prevents withdrawal of the hook. The most commonly reported ophthalmic surgical technique for removal of barbed hooks is advance-and-cut, wherein the fish hook is pushed through an iatrogenic wound to the exterior of the globe, the barb is cut off, and the shank is backed out of the entry wound. We report 2 cases of zone I OGIs with retained fish hooks successfully repaired using the back-out technique. This strategy involves enlarging the entry wound to allow the entire hook and barb to be backed out, decreasing iatrogenic injuries and eliminating the need for wire cutters.


Assuntos
Remoção de Dispositivo/métodos , Corpos Estranhos no Olho/cirurgia , Ferimentos Oculares Penetrantes/cirurgia , Procedimentos Cirúrgicos Oftalmológicos/métodos , Corpos Estranhos no Olho/diagnóstico , Ferimentos Oculares Penetrantes/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios X , Adulto Jovem
14.
Ocul Immunol Inflamm ; 28(6): 854-859, 2020 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-31013173

RESUMO

PURPOSE: To report the clinical features, severity, and management of ocular immune-related adverse events (irAEs) in the setting of immune checkpoint inhibitor therapy for metastatic malignancies. METHODS: Retrospective chart review at three tertiary ophthalmology clinics. Electronic medical records were reviewed between 2000 and 2017 for patients with new ocular symptoms while undergoing checkpoint inhibition therapy. RESULTS: Eleven patients were identified. Ocular irAEs ranged from keratoconjunctivitis sicca to Vogt-Koyanagi-Harada-like findings. Average timing of irAEs from starting checkpoint inhibitor therapy was 15.7 weeks. Ocular inflammation was successfully controlled with corticosteroids in most cases, however three patients discontinue treatment as a result of ocular inflammation with decreased visual acuity, two discontinued due to progression of metastatic disease, and one discontinued due to severe systemic irAEs. CONCLUSION: We found a wide spectrum of ocular irAEs associated with immune checkpoint inhibitors. In most cases, ocular AEs did not limit ongoing cancer treatment.


Assuntos
Inibidores de Checkpoint Imunológico/efeitos adversos , Ceratoconjuntivite Seca/induzido quimicamente , Neoplasias/tratamento farmacológico , Doenças do Nervo Óptico/induzido quimicamente , Uveíte/induzido quimicamente , Síndrome Uveomeningoencefálica/induzido quimicamente , Adulto , Idoso , Feminino , Humanos , Ipilimumab/efeitos adversos , Ceratoconjuntivite Seca/diagnóstico , Masculino , Pessoa de Meia-Idade , Nivolumabe/efeitos adversos , Doenças do Nervo Óptico/diagnóstico , Estudos Retrospectivos , Uveíte/diagnóstico , Síndrome Uveomeningoencefálica/diagnóstico
15.
J Bone Miner Res ; 34(1): 75-82, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30281863

RESUMO

Atypical femoral fractures are rare fractures that occur in the subtrochanteric or diaphyseal region of the femur with minimal or no trauma. Though the association of atypical femoral fractures (AFFs) and bisphosphonate (BP) use is a growing concern in the management of osteoporosis, currently there is little knowledge about which patients may be at risk for an atypical femoral fracture. Given that these fractures initiate in the femoral cortex, we aimed to determine whether cortical bone tissue properties (bone material strength index; BMSi), as measured by in vivo impact microindentation, are altered in atypical fracture patients. We also aimed to identify factors associated with the BMSi measurements. We enrolled postmenopausal women with recent AFFs (n = 15) or hip fractures (Hip Fxs; n = 20), long-term (>5 years) BP users (n = 30), and treatment naïve controls (n = 88). We measured total hip and femoral neck BMD by DXA, cortical bone microstructure at the distal tibia by HR-pQCT, and BMSi at the midtibia by impact microindentation. BMSi values were similar in all groups, with no effects of long-term BP use or lower values in patients with AFFs or Hip Fxs, even after multivariable adjustment. BMSi measurements were independent of age, femoral BMD, duration of BP treatment, vitamin D level, and cortical bone microstructure, including cortical porosity and cortical tissue mineral density. In conclusion, impact microindentation values are not negatively affected by long-term BP use and do not appear to discriminate individuals who suffer AFFs. Thus, our results do not support clinical use of impact microindentation to identify those at risk for AFFs. This remains to be verified in larger studies. © 2018 American Society for Bone and Mineral Research.


Assuntos
Osso Cortical , Difosfonatos/administração & dosagem , Colo do Fêmur/metabolismo , Fraturas do Quadril/prevenção & controle , Pós-Menopausa/metabolismo , Tíbia/metabolismo , Idoso , Idoso de 80 Anos ou mais , Osso Cortical/metabolismo , Osso Cortical/patologia , Feminino , Colo do Fêmur/patologia , Fraturas do Quadril/metabolismo , Fraturas do Quadril/patologia , Humanos , Pessoa de Meia-Idade , Tíbia/patologia
16.
Bone ; 124: 47-52, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30998999

RESUMO

High-resolution peripheral quantitative computed tomography (HR-pQCT) is a non-invasive method of measuring volumetric bone mineral density (vBMD) and microarchitecture at the distal radius and tibia. With increasing use of this technology, it is crucial to understand the potential impact of overlying soft tissue on the accuracy of HR-pQCT measures. Thus, we examined the effects of a simulated increase in adiposity (via 6- and 12-mm thick layers of overlying circumferential fat) on HR-pQCT measures of a hydroxyapatite (HA) phantom and in women (n = 20, aged 18-75 years). In the phantom, increasing the amount of overlying fat tissue led to a corresponding decrease in the mean measured density for each HA rod. In women, fat-layering led to a decrease in total vBMD (-2.9 to -3.7%, p < 0.001), cortical vBMD (-1.4% to -5.5%, p < 0.001), and estimated failure load (-1.4 to -5.7%, p = 0.002) at the radius, with similar changes in the tibia. Trabecular microarchitectural measurements were also impacted by simulated adiposity, with fat-layering leading to decreased trabecular thickness and separation and increased trabecular number at the radius (Δ's = 5 to 12%) with more pronounced differences at the tibia (Δ's = 14 to 40%). At the tibia, fat-layering also led to decreased cortical thickness and increased cortical porosity. Altogether, these results demonstrate that overlying adipose tissue can lead to artifacts in bone measurements by HR-pQCT, resulting in an underestimation of vBMD and generally, an overestimation of bone microarchitecture impairment. Therefore, soft tissue artifact should be considered when interpreting HR-pQCT results, particularly in those with high BMI and/or marked changes in adiposity.


Assuntos
Densidade Óssea/fisiologia , Tomografia Computadorizada por Raios X , Adolescente , Adulto , Idoso , Durapatita/química , Feminino , Voluntários Saudáveis , Humanos , Pessoa de Meia-Idade , Imagens de Fantasmas , Rádio (Anatomia)/diagnóstico por imagem , Rádio (Anatomia)/fisiologia , Tíbia/diagnóstico por imagem , Tíbia/fisiologia , Adulto Jovem
18.
J Clin Endocrinol Metab ; 103(1): 336-345, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29121215

RESUMO

Context: Growth in healthy children is associated with changes in bone density and microarchitecture. Trabecular morphology is an additional important determinant of bone strength, but little is currently known about trabecular morphology in healthy young people. Objective: To investigate associations of trabecular morphology with increasing maturity and with body composition in healthy girls. Design: Cross-sectional study. Setting: Academic research center. Participants: Eighty-six healthy girls aged 9 to 18 years. Main Outcome Measures: High-resolution peripheral quantitative computed tomography and individual trabecula segmentation were used to assess volumetric bone density, microarchitecture, and trabecular morphology (plate-like vs rod-like) at the distal radius and tibia. Results: Plate-like bone volume divided by total volume (pBV/TV) increased statistically significantly at the tibia (R = 0.41, P < 0.001), whereas rod-like BV/TV (rBV/TV) decreased statistically significantly at both the radius and tibia (R = -0.34, P = 0.003 and R = -0.28, P = 0.008, respectively) with increasing bone age. In multivariable models, lean mass positively correlated with pBV/TV and plate number at the radius and with plate thickness at both sites. In contrast, fat mass negatively correlated with plate thickness at the tibia and plate surface at both sites. In addition, fat mass positively correlated with rBV/TV and number at the tibia. pBV/TV at both the distal radius and tibia was positively correlated with spine bone mineral density. Conclusions: Increasing maturity across late childhood and adolescence is associated with changes in trabecular morphology anticipated to contribute to bone strength. Body composition correlates with trabecular morphology, suggesting that muscle mass and adiposity in youth may contribute to long-term skeletal health.


Assuntos
Determinação da Idade pelo Esqueleto/métodos , Composição Corporal , Densidade Óssea , Osso Esponjoso/anatomia & histologia , Coluna Vertebral/anatomia & histologia , Tomografia Computadorizada por Raios X/métodos , Adolescente , Osso Esponjoso/diagnóstico por imagem , Criança , Estudos Transversais , Feminino , Seguimentos , Humanos , Prognóstico , Coluna Vertebral/diagnóstico por imagem
19.
Bone ; 112: 194-201, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29730277

RESUMO

Whole-bone analyses can obscure regional heterogeneities in bone characteristics. Quantifying these heterogeneities might improve our understanding of the etiology of injuries, such as lower-extremity stress fractures. Here, we performed regional analyses of high-resolution peripheral quantitative computed tomography images of the ultradistal tibia in young, healthy subjects (age range, 18 to 30 years). We quantified bone characteristics across four regional sectors of the tibia for the following datasets: white women (n = 50), black women (n = 51), white men (n = 50), black men (n = 34), and all subjects (n = 185). After controlling for potentially confounding variables, we observed statistically significant variations in most of the characteristics across sectors (p < 0.05). Most of the bone characteristics followed a similar trend for all datasets but with different magnitudes. Regardless of race or sex, the anterior sector had the lowest trabecular and total volumetric bone mineral density and highest trabecular separation (p < 0.001), while cortical thickness was lowest in the medial sector (p < 0.05). Accordingly, the anterior sector also had the lowest elastic modulus in the anterior-posterior and superior-inferior directions (p < 0.001). In all sectors, the mean anisotropy was ~3, suggesting cross-sector similarity in the ratios of loading in these directions. In addition, the bone characteristics from regional and whole-bone analyses differed in all datasets (p < 0.05). Our findings on the heterogeneous nature of bone microarchitecture in the ultradistal tibia may reflect an adaptation of the bone to habitual loading conditions.


Assuntos
Densidade Óssea/fisiologia , Tíbia/diagnóstico por imagem , Adolescente , Adulto , Negro ou Afro-Americano , Módulo de Elasticidade , Feminino , Humanos , Masculino , Tomografia Computadorizada por Raios X , População Branca , Adulto Jovem
20.
Bioeng Transl Med ; 3(1): 58-70, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29376134

RESUMO

The ability to perform laboratory testing near the patient and with smaller blood volumes would benefit patients and physicians alike. We describe our design of a miniaturized clinical laboratory system with three components: a hardware platform (ie, the miniLab) that performs preanalytical and analytical processing steps using miniaturized sample manipulation and detection modules, an assay-configurable cartridge that provides consumable materials and assay reagents, and a server that communicates bidirectionally with the miniLab to manage assay-specific protocols and analyze, store, and report results (i.e., the virtual analyzer). The miniLab can detect analytes in blood using multiple methods, including molecular diagnostics, immunoassays, clinical chemistry, and hematology. Analytical performance results show that our qualitative Zika virus assay has a limit of detection of 55 genomic copies/ml. For our anti-herpes simplex virus type 2 immunoglobulin G, lipid panel, and lymphocyte subset panel assays, the miniLab has low imprecision, and method comparison results agree well with those from the United States Food and Drug Administration-cleared devices. With its small footprint and versatility, the miniLab has the potential to provide testing of a range of analytes in decentralized locations.

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