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1.
Artigo em Inglês | MEDLINE | ID: mdl-33586540

RESUMO

The cervical spine injury is a complicated procedure in the combination of different injury loads and postures. The aim of this study is to investigate the injury mechanism considering different types of cervical curvatures subjected to contusion loads. A finite element model of a cervical spinal cord was constructed. Gray matter, white matter and pia matter were modeled and hyperelastic material properties were assigned. Convergence analysis and validation analysis were carried out. The model was simulated in 3 different spinal curvatures and loaded by 2 directions with 4 compression degrees. The maximum von Mises stress in the whole model was concentrated in the pia matter in all loading cases. When investigating spinal cord injury, the pia matter must be considered. For all three curvatures, the stress in the gray matter and white matter was higher in front-to-back loading condition than that in back-to-front loading condition. The front-to-back impact may cause a larger damage. A back-to-front load damaged the structure around the central canal and a front-to-back contusion load damaged the anterior horn of the spinal cord at most time. From the view of the maximum stress, the lordotic curvature did not show significant buffering effect. However, the pathological curvature had large areas affected and the lordotic curvature showed some benefits to some degree from the view of stress distribution.

2.
Environ Int ; 146: 106305, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33395947

RESUMO

BACKGROUND: Bisphenol A (BPA) can cause detrimental effects on fetal growth. However, the effects of BPA alternatives, such as bisphenol F (BPF) and bisphenol S (BPS), on fetal growth are less known. OBJECTIVE: To investigate the relationships of prenatal BPA, BPF, and BPS exposures with fetal growth parameters and gestational age. METHODS: Urinary BPA, BPF, and BPS were measured in 1,197 pregnant women before delivery in a Chinese cohort. The associations of prenatal exposure to BPA, BPF, and BPS with fetal growth parameters and gestational age were examined, and associations stratified by fetal sex were also conducted. We used a restricted cubic splines (RCS) model to examine the dose-response associations between exposures and outcomes. RESULTS: Maternal urinary BPA and BPF were negatively related to birth length (-0.30 cm, 95% CI: -0.44, -0.15 and -0.21 cm, 95% CI: -0.36, -0.07 comparing the extreme exposure groups, respectively, both p for trends < 0.01). These associations were more pronounced in girls with inverted U-shaped dose-response relationships. Maternal urinary BPA and BPF were positively related to ponderal index (0.05 g/cm3 × 100, 95% CI: 0.01, 0.09 and 0.04 g/cm3 × 100, 95% CI: 0.01, 0.08 comparing the extreme exposure groups, respectively, both p for trends = 0.02), and maternal urinary BPS was associated with shorter gestational age (-0.20 weeks, 95% CI: -0.37, -0.03 comparing the extreme exposure groups, p for trend = 0.02). These associations were only observed in girls and exhibited a linear dose-response relationship. CONCLUSIONS: Prenatal BPA, BPF, and BPS exposures were associated with detrimental effects on fetal growth parameters, and stronger effects were noted in female infants.


Assuntos
Efeitos Tardios da Exposição Pré-Natal , Compostos Benzidrílicos/toxicidade , Estudos de Coortes , Feminino , Desenvolvimento Fetal , Idade Gestacional , Humanos , Lactente , Recém-Nascido , Masculino , Fenóis , Gravidez , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente
3.
Curr Med Sci ; 40(5): 817-821, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33123896

RESUMO

In the period of regular epidemic prevention and control of Coronavirus disease 2019 (COVID-19) in our country, work resumption has been fully advanced. But there are still new sporadic local cases and imported cases across the country. In this situation, whether kindergartens reopening will increase the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread still remains uncertain. We reviewed two pediatric patients with moderate COVID-19, collected the epidemiologic information and monitored the cycle threshold value of rectal specimen and the viral loads, and discussed the transmission of SARS-CoV-2 in pediatric patients and the virulence of feces in children with moderate COVID-19, in order to analyze the risk of kindergartens reopening.


Assuntos
Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/prevenção & controle , Fezes/virologia , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Betacoronavirus/genética , Betacoronavirus/patogenicidade , Pré-Escolar , China/epidemiologia , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/transmissão , Feminino , Humanos , Pandemias/estatística & dados numéricos , Pais , Pneumonia Viral/epidemiologia , Pneumonia Viral/transmissão , Instituições Acadêmicas , Carga Viral , Eliminação de Partículas Virais
4.
Technol Health Care ; 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32538887

RESUMO

BACKGROUND: The volar locking plate technique with an L-shaped incision of the PQ muscle through the classic volar Henry approach is a popular method for treating distal radius fractures. Recently we revised and improved this traditional technique by performing mini-invasive surgery. OBJECTIVE: The purpose of this study was to evaluate the clinical effects after fixation of distal radius fracture with volar locking palmar plates while preserving the pronator quadratus through minimally invasive approach. METHODS: From May 2014 to March 2017, 58 patients (38 males and 21 females) with an age range of 22-72 years (mean age 44.6 years) and with distal radius fractures underwent open reduction and internal fixation with volar locking palmar plates. The patients were classified as 23A-2 through 23C-2 according to the Orthopedic Trauma Association fracture classification system. All surgeries were completed by one trained team. The group that received volar locking palmar plates of distal radius performed with the traditional method through Henry approach involved 33 patients (21 males and 12 females) and the group that received PQ through minimally invasive approach group involved 25 patients (16 males and 9 females). We compared the two groups for wrist pain, forearm range of motion, grip strength, preoperative complications and wrist functional recovery score. RESULTS: The minimum follow-up for the whole cohort was one year. The differences between the two groups were significant in terms of wrist pain, forearm range of motion, grip strength and wrist function at 1, 2, 6 weeks postoperatively, but insignificant at 3 and 12 months postoperatively. In the minimally invasive group a case of limited extension of the forefinger 3 months postoperatively was found. No significant differences were found for preoperative complications and radiographs postoperatively. CONCLUSION: Fixation with volar locking palmar plates through minimally invasive approach is a satisfactory and optional method in the treatment of distal radius fractures. This technique yields better early wrist function, shortens rehabilitation time and gets high psychological satisfaction.

5.
Math Biosci Eng ; 17(3): 2272-2283, 2020 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-32233534

RESUMO

Injury of cervical spine is a common injury of locomotor system usually accompanied by spinal cord injury, however the injury mechanism of contusion load to the spinal cord is not clear. This study aims to investigate its injury mechanism associated with the contusion load, with different extents of spinal cord compression. A finite element model of cervical spinal cord was established and two scenarios of contusion injury loading conditions, i.e. back-to-front and front-to-back loads, were adopted. Four different compression displacements were applied to the middle section of the cervical spinal cord. The distributions of von Mises stress in middle transverse cross section were obtained from the finite element analysis. For the back-to-front loading scenario, the stress concentration was found in the area at and near the central canal and the damage may lead to the central canal syndrome from biomechanical point of view. With the front-to-back load, the maximum von Mises stress located in central canal area of gray matter when subject to 10% compression, whilst it appeared at the anterior horn when the compression increased. For the white matter, the maximum von Mises stress appeared in the area of the anterior funiculus. This leads to complicated symptoms given rise by damage to multiple locations in the cervical spinal cord. The illustrative results demonstrated the need of considering different loading scenarios in understanding the damage mechanisms of the cervical spinal cord, particularly when the loading conditions were given rise by different pathophysiological causes.

6.
ACS Nano ; 14(1): 927-936, 2020 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-31927974

RESUMO

Image-guided surgery plays a crucial role in realizing complete tumor removal, reducing postoperative recurrence and increasing patient survival. However, imaging of tumor lesion in the typical metabolic organs, e.g., kidney and liver, still has great challenges due to the intrinsic nonspecific accumulation of imaging probes in those organs. Herein, we report an in situ self-assembled near-infrared (NIR) peptide probe with tumor-specific excretion-retarded (TER) effect in tumor lesions, enabling high-performance imaging of human renal cell carcinoma (RCC) and achieving complete tumor removal, ultimately reducing postoperative recurrence. The NIR peptide probe first specifically recognizes αvß3 integrin overexpressed in renal cancer cells, then is cleaved by MMP-2/9, which is up-regulated in the tumor microenvironment. The probe residue spontaneously self-assembles into nanofibers that exhibit an excretion-retarded effect in the kidney, which contributes to a high signal-to-noise (S/N) ratio in orthotopic RCC mice. Intriguingly, the TER effect also enables precisely identifying eye-invisible tiny lesions (<1 mm), which contributes to complete tumor removal and significantly reduces the postoperative recurrence compared with traditional surgery. Finally, the TER strategy is successfully employed in high-performance identification of human RCC in an ex vivo kidney perfusion model. Taken together, this NIR peptide probe based on the TER strategy is a promising method for detecting tumors in metabolic organs in diverse biomedical applications.

7.
Neural Regen Res ; 15(8): 1437-1450, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31997803

RESUMO

Spinal cord injury is linked to the interruption of neural pathways, which results in irreversible neural dysfunction. Neural repair and neuroregeneration are critical goals and issues for rehabilitation in spinal cord injury, which require neural stem cell repair and multimodal neuromodulation techniques involving personalized rehabilitation strategies. Besides the involvement of endogenous stem cells in neurogenesis and neural repair, exogenous neural stem cell transplantation is an emerging effective method for repairing and replacing damaged tissues in central nervous system diseases. However, to ensure that endogenous or exogenous neural stem cells truly participate in neural repair following spinal cord injury, appropriate interventional measures (e.g., neuromodulation) should be adopted. Neuromodulation techniques, such as noninvasive magnetic stimulation and electrical stimulation, have been safely applied in many neuropsychiatric diseases. There is increasing evidence to suggest that neuromagnetic/electrical modulation promotes neuroregeneration and neural repair by affecting signaling in the nervous system; namely, by exciting, inhibiting, or regulating neuronal and neural network activities to improve motor function and motor learning following spinal cord injury. Several studies have indicated that fine motor skill rehabilitation training makes use of residual nerve fibers for collateral growth, encourages the formation of new synaptic connections to promote neural plasticity, and improves motor function recovery in patients with spinal cord injury. With the development of biomaterial technology and biomechanical engineering, several emerging treatments have been developed, such as robots, brain-computer interfaces, and nanomaterials. These treatments have the potential to help millions of patients suffering from motor dysfunction caused by spinal cord injury. However, large-scale clinical trials need to be conducted to validate their efficacy. This review evaluated the efficacy of neural stem cells and magnetic or electrical stimulation combined with rehabilitation training and intelligent therapies for spinal cord injury according to existing evidence, to build up a multimodal treatment strategy of spinal cord injury to enhance nerve repair and regeneration.

8.
Chin Med J (Engl) ; 132(22): 2690-2697, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31765355

RESUMO

BACKGROUND: Previously, the authors modified the surgical technique to preserve tibial bone mass for Oxford unicompartmental knee arthroplasty (UKA). The purpose of this study was to determine the clinical outcomes and values of this modified technique. METHODS: Clinical data of 34 consecutive patients who underwent the unilateral modified UKA technique (modified group, 34 knees) were retrospectively analyzed. To compare the outcome, a match-paired control group (conventional group, 34 knees) of an equal number of patients using the conventional technique system in the same period were selected and matched with respect to diagnosis, age, pre-operative range of motion (ROM), and radiological grade of knee arthrosis. Clinical outcomes including knee Hospital for Special Surgery (HSS) score, ROM, and complications were compared between the two groups. Post-operative radiographic assessments included hip-knee-ankle angle (HKA), joint line change, implant position, and alignment. RESULTS: The mean follow-up time was 38.2 ±â€Š6.3 months. There was no difference in baseline between the two groups. The amount of proximal tibial bone cut in the modified group was significantly less than that of the conventional group (4.7 ±â€Š1.1 mm vs. 6.7 ±â€Š1.3 mm, t = 6.45, P < 0.001). Joint line was elevated by 2.1 ±â€Š1.0 mm in the modified group compared with -0.5 ±â€Š1.7 mm in the conventional group (t = -7.46, P < 0.001). No significant differences were observed between the two groups after UKA with respect to HSS score, VAS score, ROM, and HKA. Additionally, the accuracy of the post-operative implant position and alignment was similar in both groups. As for implant size, the tibial implant size in the modified group was larger than that in the conventional group (χ = 4.95, P = 0.035). CONCLUSIONS: The modified technique for tibial bone sparing was comparable with the conventional technique in terms of clinical outcomes and radiographic assessments. It can preserve tibial bone mass and achieve a larger cement surface on the tibial side.


Assuntos
Artroplastia do Joelho/métodos , Osteoartrite do Joelho/cirurgia , Idoso , Humanos , Articulação do Joelho/cirurgia , Pessoa de Meia-Idade , Osteoartrite do Joelho/fisiopatologia , Amplitude de Movimento Articular/fisiologia , Estudos Retrospectivos , Tíbia
9.
J Chromatogr B Analyt Technol Biomed Life Sci ; 1126-1127: 121738, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31377566

RESUMO

Myocardial Infarction (MI) is one of the most common causes of deaths worldwide. Thiols have been reported to play a key role in physiological and pathological processes of MI. Comprehensive analysis of thiols would be conducive to fully elucidate the relation between thiols and MI. In the current study, we analyze the metabolomic differences of thiols in serum between MI patients (n = 30) and healthy controls (HCs, n = 30) by stable isotope labeling-dispersive solid phase extraction-liquid chromatography-full scan-Orbitrap-mass spectrometry analysis (IL-DSPE-LC-full scan-Orbitrap MS) method. We detected 300 potential thiols in serum of MI patients and HCs, among which, 67 thiols were positively or putatively identified. Furthermore, we found that the levels of 71 thiols in serum exhibited significant difference between MI patients and HCs. In the transsulfuration pathway, we observed that Cys and Hcys were upregulated, while GSH were downregulated. Our results provide a comprehensive understanding of thiols metabolome in human serum between MI patients and HCs.


Assuntos
Metabolômica/métodos , Infarto do Miocárdio/metabolismo , Compostos de Sulfidrila/sangue , Compostos de Sulfidrila/metabolismo , Cromatografia Líquida/métodos , Análise por Conglomerados , Humanos , Marcação por Isótopo/métodos , Espectrometria de Massas , Metaboloma/fisiologia , Infarto do Miocárdio/sangue
10.
Environ Int ; 123: 301-309, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30553203

RESUMO

BACKGROUND: Bisphenol F (BPF) and bisphenol S (BPS) are increasingly used as alternatives to endocrine disrupting chemical bisphenol A (BPA). Evidence from in vitro and animal studies demonstrates that BPA, BPF and BPS induce oxidative stress, a proposed mechanism that is relevant to various adverse health effects. Evaluation in humans is hampered by the potentially high within-subject variability of urinary measurements. OBJECTIVE: To evaluate the variability and associations of levels of BPA, BPS, BPF and 3 oxidative stress markers [i.e., 8-hydroxy-2-deoxyguanosine (8-OHdG), 8-iso-prostaglandin F2α (8-isoPGF2α) and 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA)] in urine collected on multiple occasions over 3 months. METHOD: A total of 529 spot urine samples, including 88 first morning voids (FMVs) and 24-h specimens, were gathered from 11 adult men on days 0, 1, 2, 3, 4, 30, 60 and 90 and analyzed for BPA, BPF, BPS, 8-OHdG, 8-isoPGF2α and HNE-MA. Intraclass correlation coefficients (ICCs) were estimated to characterize the reproducibility of urinary bisphenols and oxidative stress markers, and linear mixed models were applied to assess the associations between markers of exposure and response. RESULTS: BPA and BPF were detected in ≥85% of the spot samples, while BPS in 13% of the samples. High degrees of within-subject variability were found for BPA, BPF, 8-OHdG, 8-isoPGF2α and HNE-MA in spot samples, FMVs and 24-h specimens (creatinine-corrected ICCs ≤ 0.37). The sensitivities were low-to-moderate (0.30-0.63) when using single spot samples or FMVs to predict high (>27th, or 36th percentile) 3-month average urinary levels of BPA, BPF, 8-OHdG, 8-isoPGF2α and HNE-MA. Collecting repeated specimens at different time points improved the accuracy of classification for markers of exposure and response. Elevated urinary BPA and BPF were associated with significantly higher levels of oxidative stress markers. CONCLUSIONS: Repeated urinary specimens are required to characterize bisphenol exposure levels and the oxidative stress status of individuals. Exposure to BPA and BPF may partly contribute to the elevated urinary levels of oxidative stress makers in adult men.


Assuntos
Compostos Benzidrílicos/urina , Estresse Oxidativo , Fenóis/urina , Sulfonas/urina , 8-Hidroxi-2'-Desoxiguanosina , Adulto , Animais , Variação Biológica Individual , Biomarcadores/urina , Desoxiguanosina/análogos & derivados , Desoxiguanosina/urina , Humanos , Masculino , Reprodutibilidade dos Testes
11.
Sci Rep ; 8(1): 9988, 2018 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-29968807

RESUMO

This study investigatedthe different effects of long-term glucocorticoid (GC) interventions on the microarchitectures of cortical and cancellous bones of the femoral head. Eighteen female skeletal mature sheep were randomly allocated into 3 groups, 6 each. Group 1 received prednisolone interventions (0.60 mg/kg/day, 5 times weekly) for 7 months. Group 2 received the same interventions as Group 1 and then further observed 3 months without interventions. Control Group was left nonintervention. After killing the animals, all femoral heads were scanned by micro-CT to determine their microstructural properties. In cancellous bone of femoral head, GC interventions led to significant decrease of bone volume fraction, trabecular thickness, trabecular separation, but increase of structure model index and bone surface density (p < 0.05). While in cortical bone, there were no differences between the Group 1 and in microstructural properties (p > 0.05) except greater trabecular thickness in the control group. In addition, three months after cessation of glucocorticoid interventions, most microstructural properties of cancellous bone were significant reversed, but not cortical thickness of femoral head. In contrast to cancellous bone, the microarchitectures of cortical bone were not changed obviously after long-term GC interventions.


Assuntos
Osso Esponjoso/efeitos dos fármacos , Osso Cortical/efeitos dos fármacos , Cabeça do Fêmur/efeitos dos fármacos , Animais , Densidade Óssea/efeitos dos fármacos , Feminino , Fêmur/efeitos dos fármacos , Cabeça do Fêmur/anatomia & histologia , Glucocorticoides/efeitos adversos , Glucocorticoides/farmacologia , Prednisolona/efeitos adversos , Prednisolona/farmacologia , Ovinos , Microtomografia por Raio-X/métodos
12.
J Orthop Translat ; 12: 36-44, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29662777

RESUMO

Background/Objective: This is a multicentre, randomised, double-blind, placebo-controlled clinical trial to investigate the safety and efficacy of Chinese herbal Fufang Xian Ling Gu Bao (XLGB) with antiadipogenic compounds for the prevention of corticosteroid (CS)-induced osteonecrosis of femoral head (ONFH). Methods: Patients of both genders, aged between 18 and 65 years, with diseases such as systemic lupus erythematosus, nephrosis, dermatosis and rheumatoid arthritis indicated for CS treatment and who did not show magnetic resonance imaging of ONFH at baseline were recruited into the study and then randomised into either XLGB group (n = 129) with daily oral administration of XLGB or placebo group (n = 146). Results: Magnetic resonance imaging revealed a total of 30 ONFH cases at 6 months after CS treatment, with 6.98% (9 of 129 cases) and 14.4% (21 of 146 cases) in the XLGB group and placebo group, respectively, (p < 0.05), i.e., a 2-fold significantly less ONFH identified in the XLGB treatment group. Blood tests suggested that XLGB significantly inhibited the elevation of activated protein C resistance induced by CS treatment. Conclusion: This is the first multicentre clinical study to demonstrate that the antiadipogenic compounds-rich herbal Fufang (formula) XLGB is effective in preventing CS-associated ONFH in patients with immune-inflammatory diseases under CS treatment. The translational potential of this article: The translation potential of this clinical trial is that the initially officially approved clinical indication for XLGB for treatment of osteoporosis has been now also proven to be effective for a new clinical application.

13.
Biomed Res Int ; 2018: 4517471, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29511680

RESUMO

The normal physiological loads from muscles experienced by the spine are largely unknown due to a lack of data. The aim of this study is to investigate the effects of varying muscle directions on the outcomes predicted from finite element models of human lumbar spine. A nonlinear finite element model of L3-L5 was employed. The force of the erector spinae muscle, the force of the rectus abdominis muscle, follower loads, and upper body weight were applied. The model was fixed in a neural standing position and the direction of the force of the erector spinae muscle and rectus abdominis muscle was varied in three directions. The intradiscal pressure, reaction moments, and intervertebral rotations were calculated. The intradiscal pressure of L4-L5 was 0.56-0.57 MPa, which agrees with the in vivo pressure of 0.5 MPa from the literatures. The models with the erector spinae muscle loaded in anterior-oblique direction showed the smallest reaction moments (less than 0.6 Nm) and intervertebral rotations of L3-L4 and L4-L5 (less than 0.2 degrees). In comparison with loading in the vertical direction and posterior-oblique direction, the erector spinae muscle loaded in the anterior-oblique direction required lower external force or moment to keep the lumbar spine in the neutral position.


Assuntos
Vértebras Lombares/fisiologia , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Coluna Vertebral/fisiologia , Fenômenos Biomecânicos , Análise de Elementos Finitos , Humanos , Região Lombossacral/fisiologia , Modelos Biológicos , Postura , Pressão , Suporte de Carga
14.
Artigo em Inglês | MEDLINE | ID: mdl-29518632

RESUMO

Low-molecular-weight thiols play important roles in a variety of pathological processes and are closely associated with a wide range of diseases. In this study, a selective and sensitive method was developed for the simultaneous determination of all the 7 thiols occurring in the transsulfuration pathway (Cysteine (Cys), homocysteine (Hcys), glutathione (GSH), N-acetylcysteine (Nac), cysteinylglycine (CysGly), glutamylcysteine (GluCys) and cysteamine (CA)) in human serum by in-vitro stable isotope labeling - dispersive solid phase extraction - liquid chromatography - tandem mass spectrometry analysis (IL-DSPE-LC-MS/MS). In the proposed method, a pair of stable isotope-labeling reagents, BQB (ω-bromoacetonylquinolinium bromide) and BQB-D7, were utilized to label thiols in human serum samples and thiol standards, respectively. The BQB labeled thiols which carry a positive charge were extracted and purified with C8-SO3H-based DSPE followed by LC-MS/MS analysis. Good linearities for 7 thiols occurring in the transsulfuration pathway were obtained with the coefficient of determination (R2) >0.9901. The limits of detection (LODs) were in the range of 0.7-6.0 nmol/L. The method was further applied to investigate the contents change of 7 thiols in human serum samples of type 2 diabetes mellitus (T2DM) patients and breast cancer (BC) patients. The results showed that the contents of these thiols occurring in the transsulfuration pathway significantly changed and were highly diseases-related. In addition, partial least squares discriminant analysis (PLS-DA) suggested excellent classification performance between patients and healthy controls. The findings indicated that these significantly changed thiols occurring in the transsulfuration pathway in T2DM patients and BC patients might serve as the indicator for the diagnosis of T2DM and BC. Taken together, the developed IL-DSPE-LC-MS/MS method provides a promising tool for the sensitive analysis of thiols from complex biological samples, which may promote the in-depth investigation of the functions of thiols.


Assuntos
Cromatografia Líquida/métodos , Marcação por Isótopo/métodos , Extração em Fase Sólida/métodos , Compostos de Sulfidrila/sangue , Espectrometria de Massas em Tandem/métodos , Neoplasias da Mama/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Feminino , Humanos , Análise dos Mínimos Quadrados , Limite de Detecção , Modelos Lineares , Curva ROC , Reprodutibilidade dos Testes
15.
Chin Med J (Engl) ; 131(2): 194-199, 2018 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-29336368

RESUMO

BACKGROUND: The quality of the lateral compartment cartilage is important to preoperative evaluation and prognostic prediction of unicompartmental knee arthroplasty (UKA). Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) enables noninvasive assessment of glycosaminoglycan (GAG) content in cartilage. This study aimed to determine the GAG content of the lateral compartment cartilage in knees scheduled to undergo Oxford medial UKA. METHODS: From December 2016 to May 2017, twenty patients (20 osteoarthritic knees) conforming to the indications for Oxford medial UKA were included as the osteoarthritis (OA) group, and 20 healthy volunteers (20 knees) paired by sex, knee side, age (±3 years), and body mass index (BMI) (±3 kg/m2) were included as the control group. The GAG contents of the weight-bearing femoral cartilage (wbFC), the posterior non-weight-bearing femoral cartilage (pFC), the lateral femoral cartilage (FC), and tibial cartilage (TC) were detected using dGEMRIC. The dGEMRIC indices (T1Gd) were calculated in the middle three consecutive slices of the lateral compartment. Paired t-tests were used to compare the T1Gd in each region of interest between the OA group and control group. RESULTS: The average age and BMI in the two groups were similar. In the OA group, T1Gd of FC and TC was 386.7 ± 50.7 ms and 429.6 ± 59.9 ms, respectively. In the control group, T1Gd of FC and TC was 397.5 ± 52.3 ms and 448.6 ± 62.5 ms, respectively. The respective T1Gd of wbFC and pFC was 380.0 ± 47.8 ms and 391.0 ± 66.3 ms in the OA group and 400.3 ± 51.5 ms and 393.6 ± 57.9 ms in the control group. Although the T1Gd of wbFC and TC tended to be lower in the OA group than the control group, there was no significant difference between groups in the T1Gd in any of the analyzed cartilage regions (P value of wbFC, pFC, FC, and TC was 0.236, 0.857, 0.465, and 0.324, respectively). CONCLUSIONS: The GAG content of the lateral compartment cartilage in knees conforming to indications for Oxford medial UKA is similar with those of age- and BMI-matched participants without OA.


Assuntos
Artroplastia do Joelho/métodos , Cartilagem Articular/química , Glicosaminoglicanos/análise , Osteoartrite do Joelho/cirurgia , Idoso , Índice de Massa Corporal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/metabolismo
16.
Chin Med J (Engl) ; 130(21): 2563-2568, 2017 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-29067955

RESUMO

BACKGROUND: Lateral compartmental osteoarthritis (LCOA), a major complication after medial mobile-bearing unicompartmental knee arthroplasty (UKA), is highly associated with the increased stress of the lateral compartment. This study aimed to analyze the effects on the stress and load distribution of the lateral compartment induced by lower limb alignment and coronal inclination of the tibial component in UKA through a finite element analysis. METHODS: Eight three-dimensional models were constructed based on a validated model for analyzing the biomechanical effects of implantation parameters on the lateral compartment after medial Oxford UKA: postoperative lower limb alignment of 3° valgus, neutral and 3° varus, and the inclination of tibial components placed in 4°, 2° valgus, square, and 2° and 4° varus. The contact stress of femoral and tibial cartilage and load distribution were calculated for all models. RESULTS: In the 3° valgus lower limb alignment model, the contact stress of femoral (3.38 MPa) and tibial (3.50 MPa) cartilage as well as load percentage (45.78%) was highest compared to any other model, and was increased by 36.75%, 47.70%, and 27.63%, respectively when compared to 3° varus. In the condition of a neutral position, the outcome was comparable for the different tibial tray inclination models. The inclination did not greatly affect the lateral compartmental stress and load distribution. CONCLUSIONS: This study suggested that slightly varus (undercorrection) lower limb alignment might be a way to prevent LCOA in medial mobile-bearing UKA. However, the inclination (4° varus to 4° valgus) of the tibial component in the coronal plane would not be a risk factor for LCOA in neutral position.


Assuntos
Artroplastia do Joelho/efeitos adversos , Adulto , Artroplastia do Joelho/métodos , Fenômenos Biomecânicos , Análise de Elementos Finitos , Humanos , Prótese do Joelho , Masculino , Osteoartrite do Joelho/cirurgia , Tíbia/cirurgia
17.
Chin Med J (Engl) ; 130(21): 2569-2574, 2017 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-29067956

RESUMO

BACKGROUND: The lateral pillar of the femoral head is an important site for disease development such as osteonecrosis of the femoral head. The femoral head consists of medial, central, and lateral pillars. This study aimed to determine the biomechanical effects of early osteonecrosis in pillars of the femoral head via a finite element (FE) analysis. METHODS: A three-dimensional FE model of the intact hip joint was constructed from the image data of a healthy control. Further, a set of six early osteonecrosis models was developed based on the three-pillar classification. The von Mises stress and surface displacements were calculated for all models. RESULTS: The peak values of von Mises stress in the cortical and cancellous bones of normal model were 6.41 MPa and 0.49 MPa, respectively. In models with necrotic lesions in the cortical and cancellous bones, the von Mises stress and displacement of lateral pillar showed significant variability: the stress of cortical bone decreased from 6.41 MPa to 1.51 MPa (76.0% reduction), while cancellous bone showed an increase from 0.49 MPa to 1.28 MPa (159.0% increase); surface displacements of cortical and cancellous bones increased from 52.4 µm and 52.1 µm to 67.9 µm (29.5%) and 61.9 µm (18.8%), respectively. In addition, osteonecrosis affected not only pillars but also adjacent structures in terms of the von Mises stress and surface displacement levels. CONCLUSIONS: This study suggested that the early-stage necrosis in the femoral head could increase the risk of collapse, especially in lateral pillar. On the other hand, the cortical part of lateral pillar was found to be the main biomechanical support of femoral head.


Assuntos
Cabeça do Fêmur/fisiopatologia , Análise de Elementos Finitos , Osteonecrose/fisiopatologia , Humanos , Estresse Mecânico
18.
J Healthc Eng ; 2017: 7981513, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29065645

RESUMO

Facetectomy is an important intervention for spinal stenosis but may lead to spinal instability. Biomechanical knowledge for facetectomy can be beneficial when deciding whether fusion is necessary. Therefore, the aim of this study was to investigate the biomechanical effect of different grades of facetectomy. A three-dimensional nonlinear finite element model of L3-L5 was constructed. The mobility of the model and the intradiscal pressure (IDP) of L4-L5 for standing were inside the data from the literature. The effect of graded facetectomy on intervertebral rotation, IDP, facet joint forces, and maximum von Mises equivalent stresses in the annuli was analyzed under flexion, extension, left/right lateral bending, and left/right axial rotation. Compared with the intact model, under extension, unilateral facetectomy increased the range of intervertebral rotation (IVR) by 11.7% and IDP by 10.7%, while the bilateral facetectomy increased IVR by 40.7% and IDP by 23.6%. Under axial rotation, the unilateral facetectomy and the bilateral facetectomy increased the IVR by 101.3% and 354.3%, respectively, when turned to the right and by 1.1% and 265.3%, respectively, when turned to the left. The results conclude that, after unilateral and bilateral facetectomy, care must be taken when placing the spine into extension and axial rotation posture from the biomechanical point of view.


Assuntos
Fusão Vertebral , Estenose Espinal/cirurgia , Articulação Zigapofisária/cirurgia , Adulto , Fenômenos Biomecânicos , Simulação por Computador , Análise de Elementos Finitos , Humanos , Instabilidade Articular , Laminectomia , Vértebras Lombares , Região Lombossacral , Masculino , Modelos Anatômicos , Postura , Pressão , Amplitude de Movimento Articular , Rotação
19.
Clin Biomech (Bristol, Avon) ; 41: 34-38, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27918892

RESUMO

BACKGROUND: Whether muscle weakness is a cause, or result, of degenerative spondylolisthesis is not currently well understood. Little biomechanical evidence is available to offer an explanation for the mechanism behind exercise therapy. Therefore, the aim of this study is to investigate the effects of back muscle weakness on degenerative spondylolisthesis and to tease out the biomechanical mechanism of exercise therapy. METHODS: A nonlinear 3-D finite element model of L3-L5 was constructed. Forces representing global back muscles and global abdominal muscles, follower loads and an upper body weight were applied. The force of the global back muscles was reduced to 75%, 50% and 25% to simulate different degrees of back muscle weakness. An additional boundary condition which represented the loads from other muscles after exercise therapy was set up to keep the spine in a neutral standing position. Shear forces, intradiscal pressure, facet joint forces and von Mises equivalent stresses in the annuli were calculated. FINDINGS: The intervertebral rotations of L3-L4 and L4-L5 were within the range of in vitro experimental data. The calculated intradiscal pressure of L4-L5 for standing was 0.57MPa, which is similar to previous in vivo data. With the back muscles were reduced to 75%, 50% and 25% force, the shear force moved increasingly in a ventral direction. Due to the additional stabilizing force and moment provided by boundary conditions, the shear force varied less than 15%. INTERPRETATION: Reducing the force of global back muscles might lead to, or aggravate, degenerative spondylolisthesis with forward slipping from biomechanical point of view. Exercise therapy may improve the spinal biomechanical environment. However, the intrinsic correlation between back muscle weakness and degenerative spondylolisthesis needs more clinical in vivo study and biomechanical analysis.


Assuntos
Músculos do Dorso/fisiopatologia , Debilidade Muscular/fisiopatologia , Espondilolistese/fisiopatologia , Adulto , Fenômenos Biomecânicos , Terapia por Exercício , Análise de Elementos Finitos , Humanos , Vértebras Lombares/fisiologia , Masculino , Postura/fisiologia , Espondilolistese/reabilitação , Articulação Zigapofisária/fisiologia
20.
Medicine (Baltimore) ; 95(8): e2866, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26937919

RESUMO

The purpose of this study is to explore the risk factors affecting the postoperative transfusion of allogeneic blood in patients undergoing orthopedics surgery with intraoperative blood salvage (IBS). A retrospective study of 279 patients undergoing orthopedic surgeries with IBS from May 2013 to May 2015 was enrolled. The binary logistic regression was used to find out the risk factors associated with postoperative transfusion of allogeneic blood in orthopedics patients with IBS, and then receiver operating characteristic (ROC) curve was drawn to determine the optimal threshold of the regression model.Single factor analysis showed that age, American Society of Anesthesiologists (ASA) grade, preoperative hemoglobin, operation time, received autologous blood, the laying time of autologous blood, bleeding volume, and postoperative drainage volume had significant effects on postoperative allogeneic blood transfusion.In binary logistic regression analysis, the independent factors predicting orthopedic patients with IBS need to transfuse allogeneic blood after surgeries were age (odds ratio [OR] = 0.415, P = 0.006), ASA grade (OR = 2.393, P = 0.035), preoperative hemoglobin (OR = 0.532, P = 0.022), and postoperative drainage volume (OR = 4.279, P = 0.000). The area under ROC curve was 0.79 and the predicted accuracy rate of the model was 81.58%.After operation, the orthopedic patients with IBS still have a high allogeneic blood transfusion rate, and IBS is not a perfect blood protection method. The logistic regression model of our study provides a reliable prediction for postoperative transfusion of allogeneic blood in orthopedic patients with IBS, which have a certain reference value.


Assuntos
Perda Sanguínea Cirúrgica/prevenção & controle , Transfusão de Sangue/estatística & dados numéricos , Recuperação de Sangue Operatório , Procedimentos Ortopédicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco
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