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1.
PLoS One ; 15(2): e0228388, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32045422

RESUMO

BACKGROUND: Amphenicols have been widely used in the pig industry in China, leading to varying degrees of drug resistance. METHODS: The systematic review was performed according to PRISMA (Preferred Reported Items for Systematic Reviews and Meta-Analysis) recommendations on studies investigating the prevalence of amphenicol-resistant Escherichia coli (E. coli) isolated from pig in mainland China from 2000 to 2018, a random-effects model was selected, then followed by meta-analysis. RESULTS: A total of 103 articles were included in the study. The results of the meta-analysis revealed that the pooled summarized prevalence of resistance to chloramphenicol (CAP) was 72.31% (95% confidence interval (95% CI) = 67.12%-77.23%) and to florfenicol (FF) was 58.64% (95% CI = 52.48%-64.67%). During the past 18 years, the resistance rate to CAP remained high initially but then declined rapidly after 2012, whereas the resistance rate to FF plateaued (54.13%-59.60%) from 2000-2018. In different parts of China, the rate of resistance to amphenicols among E. coli isolates was fairly consistent, with the exception of the north and northwest regions. CONCLUSIONS: In 2002, the veterinary use of CAP was prohibited and its resistance levels in E. coli isolated from pigs was initially maintained at a high level but then showed an obvious downward trend in recent years. Resistance to commonly used FF remained at a high but stable level.

2.
J Biomol Struct Dyn ; : 1-9, 2020 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-31918625

RESUMO

In recent years, deep neural networks have begun to receive much attention, which has obvious advantages in feature extraction and modeling. However, in the using of deep neural networks for the QSAR modeling process, the selection of various parameters (number of neurons, hidden layers, transfer functions, data set partitioning, number of iterations, etc.) becomes difficult. Thus, we proposed a new and easy method for optimizing the model and selecting Deep Neural Networks (DNN) parameters through uniform design ideas and orthogonal design methods. By using this approach, 222 chloroquine (CQ) derivatives with half maximal inhibitory concentration values reported in different kinds of literature were selected to establish DNN models and a total number of 128,000 DNN models were built to determine the optimized parameters for selecting the better models. Comparing with linear and Artificial Neural Network (ANN) models, we found that DNN models showed better performance.Communicated by Ramaswamy H. Sarma.

3.
BMC Health Serv Res ; 19(1): 955, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31829178

RESUMO

BACKGROUND: For rabies prevention and treatment, the Chinese government has been establishing standardized rabies clinics since 2016. This study aimed to investigate the distribution of rabies clinics and the achievements of newly-implemented standardized rabies clinics in mainland China, for the purpose of providing further rabies control strategies. METHODS: The number of rabies clinics, including per million inhabitants in each region, was determined. We sampled 1200 clinics from 8 provinces by multi-stage stratified sampling, and a questionnaire survey was carried out to record each clinic's achievements. Data collected from 1185 questionnaires were analyzed. RESULTS: We found that rabies clinics were mostly located in the southwest, central, and eastern regions of China; these accounted for 67.1% of all clinics. The eastern and south regions showed the lowest number of rabies clinics per million inhabitants (0.15 and 0.12, respectively). The total standard-reaching rate of rabies clinics in mainland China was only 11.0%, with significant differences in the rate among regions (X2 = 33.004, p <  0.001). Specifically, the qualified rates of supporting facilities and functional areas were 13.9% (X2 = 34.003, p <  0.001) and 56.1% (X2 = 9.943, p = 0.019), respectively. Vaccines with 2 different substrates and professional flushing equipment were provided by 40.5% (X2 = 27.935, p = 0.001) and 37.7% (X2 = 54.922, p = 0.001) of clinics, respectively. CONCLUSION: Regional differences do exist in the distribution of rabies clinics in mainland China, with relative low number per million population in south and eastern China. There are few standardized rabies clinics in mainland China. Efforts are needed to establish supporting facilities, especially for wound treatment and vaccination. Future research should focus on the improvement of rabies clinics standardization.

4.
Food Sci Nutr ; 7(10): 3146-3160, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31660129

RESUMO

The quality of agricultural products relates to the internal structure, which has long been a matter of interest in agricultural scientists. However, inspection methods of the opaque nature of internal information on agricultural products are usually destructive and require sample separation or preparation. X-ray computed tomography (X-ray CT) technology is one of the important nondestructive testing (NDT) technologies without sample separation and preparation. In this study, X-ray CT technology is used to obtain two-dimensional slice images and three-dimensional tomographic images of samples. The purpose of the review was to provide an overview of the working principle of X-ray CT technology, image processing, and analysis. This review aims to focus on the development of the agricultural products (e.g., wheat, maize, rice, apple, beef) and its applications (e.g., internal quality evaluation, microstructure observation, mechanical property measurement, and others) using CT scanner. This paper covers the aspects regarding the advantages and disadvantages of NDT technology, especially the unique advantages and limitations of X-ray CT technology on the quality inspection of agricultural products. Future prospects of X-ray CT technology are also put forward to become indispensable to the quality evaluation and product development on agricultural products.

5.
Arch Toxicol ; 93(11): 3207-3218, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31552475

RESUMO

Prediction of pEC50 values of dioxins binding with the aryl hydrocarbon receptor (AhR) is of great significance for exploring how dioxins induce toxicity in human body and evaluating their environmental behaviors and risks. To reveal the factors that influence the toxicity of dioxins, provide more accurate mathematical models for predicting the pEC50 values of dioxins, and supplement the toxicity database of persistent organic pollutants, qualitative structure-activity relationship (SAR) and two-dimensional quantitative structure-activity relationship (2D-QSAR) were used in this study. The research objects in this study were 60 organic compounds with pEC50 values and 162 compounds without pEC50 values, which included polychlorinated dibenzofurans (PCDFs), polychlorinated dibenzo-p-dioxins (PCDDs), and polybrominated dibenzo-p-dioxins (PBDDs). The qualitative structure-activity relationship (SAR) was performed first and concluded that halogen substitutions at any of the 2, 3, 7, and 8 sites increased the pEC50 value of the compound. Moreover, two-dimensional quantitative structure-activity relationship (2D-QSAR) models were established by employing multiple linear regression (MLR) method and artificial neural network (ANN) algorithm to investigate the factors affecting the pEC50 values of dioxins molecules. MLR was used to establish the well-understood linear model and ANN was used to establish a more accurate non-linear model. Both models have good fitting, robustness, and predictive ability. Importantly, the ability of dioxins binding to AhR is mainly determined by molecular descriptors including E1m, SM09_AEA (dm), RDF065u, F05 [Cl-Cl], and Neoplastic-80. In addition, the pEC50 values of the 162 dioxins without toxicity data were predicted by MLR and ANN models, respectively.

6.
Materials (Basel) ; 12(12)2019 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-31226740

RESUMO

A thin-film thermocouples (TFTCs) sensor based on silicon carbide substrate, 95 wt% tungsten-5 wt% rhenium (W-5Re) and 74 wt% tungsten-26 wt% rhenium (W-26Re) thermosensitive part with aluminum oxide protective coating layer was designed and fabricated by radio frequency (RF) magnetron sputtering. It exhibited a high thermoelectric voltage of 35.51 mV when the temperature difference was 1240 °C (the hot junction temperature was 1420 °C), with an average Seebeck coefficient of 28.63 µV/°C, which was 27% larger than the standard C-type thermocouple wires at the same temperature difference. The repeatability error was ±4.1%, the drift rate was 9.6 °C/h for 10 h and the laser response time was 0.36 ms. Compared to the traditional thermocouple, it could provide long-term temperature testing within 1420 °C for the requirement of high-temperature measurement and high response speed.

8.
J Biomed Mater Res B Appl Biomater ; 107(7): 2388-2396, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30684307

RESUMO

We investigated the effects of magnesium (Mg) on osteogenesis and bone resorption at a porous structure interface. A three-dimensional (3D)-printed porous Ti6Al4V implant coated with Mg was introduced, and polyether-ether-ketone wear particles were added to generate an animal model of implant loosening. We also examined the effects of Mg leach liquor on osteoblast/osteoclast gene expression, alkaline phosphatase activity, collagen secretion, tartrate-resistant acid phosphatase activity, and bone resorption in vitro. Mg inhibited the early stage of osteoclast differentiation and inhibited bone resorption in vitro and in vivo. However, Mg did not enhance osteogenesis in vitro or in vivo in the porous structures or in peripheral areas around the implants. For implants with porous structures, the Mg coating did not improve the osteogenic ability by itself, but could restrain peri-implant osteolysis, which may make it favorable for use in patients with osteoporosis. Further studies are needed to examine the precise mechanism of Mg-induced anti-osteolysis and the long-term effects of Mg-coated implants in humans. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2388-2396, 2019.

9.
Biomed Res Int ; 2018: 8194670, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30426016

RESUMO

Background: Although magnetic resonance imaging (MRI) can provide superior detailed images of tissues without ionizing radiation, the imaging evaluation of total knee arthroplasty (TKA) complications and posttherapy changes can be limited because of abundant artifacts on MRI scans due to metallic implants and endoprosthesis in limb salvage and fracture fixation. This study aimed to develop a novel model of TKA using a polyetheretherketone- (PEEK-) on-highly cross-linked polyethylene (HXLPE) implant and to investigate its feasibility for MRI monitoring of peri-implant bone formation, the healing process, signs of infection, and tumor recurrence after TKA. Methods: Three skeletally mature goats underwent TKA with the PEEK-on-HXLPE implant. Radiographic and MRI examinations were performed at 4 weeks postoperatively. Images were analyzed for the existence of artifact interruption and postoperative changes in the bone and peripheral soft tissue. Results: The results showed that PEEK and HXLPE were invisible, but the metal wires were clearly visualized on X-rays. On MRI scans, PEEK and HXLPE materials showed a low signal intensity, fine metal wires generated no obvious metal artifacts on MRI scans, and the marrow and soft tissue showed a continuous signal intensity without artifact interruption. Conclusions: This preliminary study introduced a novel model using PEEK-on-HXLPE knee implant for in vivo MRI monitoring of the region around the implant without metal artifacts. This novel model may be used to apply MRI to observe bone formation and the healing process around the prosthesis and the signs of infection and tumor recurrence after TKA. This model may be used to improve the diagnostic accuracy of postoperative complications of TKA clinically.


Assuntos
Articulação do Joelho/cirurgia , Metais/química , Animais , Artroplastia do Joelho/métodos , Artefatos , Cabras , Humanos , Cetonas/química , Prótese do Joelho , Imagem por Ressonância Magnética/métodos , Polietilenoglicóis/química , Período Pós-Operatório , Desenho de Prótese , Falha de Prótese , Radiografia/métodos
10.
Nanomaterials (Basel) ; 8(11)2018 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-30453623

RESUMO

Platinum-based nanomaterials have attracted much interest for their promising potentials in fields of energy-related and environmental catalysis. Designing and controlling the surface/interface structure of platinum-based nanomaterials at the atomic scale and understanding the structure-property relationship have great significance for optimizing the performances in practical catalytic applications. In this review, the strategies to obtain platinum-based catalysts with fantastic activity and great stability by composition regulation, shape control, three-dimension structure construction, and anchoring onto supports, are presented in detail. Moreover, the structure-property relationship of platinum-based nanomaterials are also exhibited, and a brief outlook are given on the challenges and possible solutions in future development of platinum-based nanomaterials towards catalytic reactions.

11.
ACS Appl Mater Interfaces ; 10(49): 42681-42687, 2018 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-30474966

RESUMO

Vacuum-ultraviolet (VUV) detector equipped on satellites has extensive application in space exploration and cosmic science. For a VUV detector, a semiconductor material with a sufficiently wide band gap is eagerly desired. In this work, a wide-band gap amorphous-MgGaO (a-MGO) film was epitaxially grown on n-type GaN substrate by atomic layer deposition and a p-i-n-type heterojunction device for VUV detection was constructed with a-MGO film as a photosensitive layer and p-type graphene as a transparent conductive layer. The device exhibits a good spectral selectivity of VUV with photovoltaic response, a high responsivity (2 mA W-1) under zero bias, and an ultrafast response speed (rise and decay time of 0.76 µs and 0.56 ms, respectively) under nanosecond VUV pulse irradiation. This newly developed device shows great potential in VUV detection for space exploration.

12.
Biomed Pharmacother ; 103: 588-597, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29677546

RESUMO

Bacitracin, a widely used metallopeptide antibiotic, has been reported to be locally used in treating wounds without systemic adverse reactions. Our preliminary study showed that bacitracin might enhance the osteogenic differentiation of human bone marrow mesenchymal stem cells (HBMSCs). The present study investigated whether bacitracin affects the osteogenic differentiation of HBMSCs and the molecular mechanisms involved. The proliferation of HBMSCs in the presence of bacitracin was examined using a cell counting kit-8 (CCK-8) assay. The effects of bacitracin on the cell cycle and apoptosis of HBMSCs were observed using flow cytometry assay. Staining and quantitative assays for alkaline phosphatase (ALP) staining, collagen deposition (Sirius Red), and mineralization (Alizarin Red) were used to study osteogenic differentiation of HBMSCs. The expression of osteogenic differentiation markers was detected using quantitative reverse transcription polymerase chain reaction (RT-qPCR) analyses. The activation of related signaling pathways was examined using a luciferase reporter assay and western blotting. Bacitracin treatment increased osteogenic differentiation of HBMSCs without cytotoxicity and did not adversely affect cell cycle progression or apoptosis. The luciferase reporter assay showed that bacitracin activated the transcription of bone morphogenetic protein-2 (BMP2) gene, a key gene in the BMP2/Smad signaling axis. Western blotting indicated that this axis was markedly activated by bacitracin stimulation of osteogenesis. Moreover, the activation of Smad phosphorylation and osteogenic differentiation by bacitracin was inhibited by a transforming growth factor (TGF)-ß/Smad inhibitor (LDN-193189 HCl) and small interfering RNA (siRNA) gene silencing (si-BMP2). In conclusion, our results suggest that bacitracin can promote osteogenesis of HBMSCs by activating the BMP2/Smad signaling axis.


Assuntos
Bacitracina/farmacologia , Proteína Morfogenética Óssea 2/metabolismo , Diferenciação Celular/fisiologia , Células-Tronco Mesenquimais/metabolismo , Osteogênese/efeitos dos fármacos , Proteínas Smad/metabolismo , Anti-Infecciosos Locais/farmacologia , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Humanos , Células-Tronco Mesenquimais/efeitos dos fármacos , Osteogênese/fisiologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
13.
Oncotarget ; 9(13): 11197-11208, 2018 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-29541407

RESUMO

T-cells, second only to macrophages, are often considered as the potential cells involved in debris-related failure of arthroplasty. Here, we assessed the effects of particulate wear debris on T-cells and inflammatory reactions. Blood samples from 25 donors were incubated with polyether-ether-ketone (PEEK) and cobalt-chromium-molybdenum (CoCrMo) particles generated by custom cryo-milling and pulverization. The T-cell phenotypes were assessed using immunostaining and flow cytometry. For the in vivo study, 0.1 mL of each particle suspension (approximately 1.0 × 108 wear particles) was injected into murine knee joints; the synovium and spleen were collected one week after the operation for histological examination and immunofluorescence staining. The T-cell responses observed included low-level activation of Th1, Th2, Th17, and CD8+ pathways after 72 h of co-culture of the particles with peripheral blood mononuclear cells. Obvious CD8+ T-cell responses were observed in local synovium and peripheral spleen, with higher inflammatory cytokine expression in the CoCrMo group. Relatively minor cytotoxic and immunological reactions were observed in vitro, with PEEK and CoCrMo particle-induced immune responses being primarily mediated by CD8+ T-cells, rather than CD4+ T-cells, in vivo. Overall, PEEK wear particles induced fewer inflammatory reactions than CoCrMo particles. This study verified that PEEK was suitable as a potential alternative for metals in total knee replacements in terms of the immunological reaction to PEEK particles, and shed light on the effects of wear particles from polymer and metal-based implants on immune responses.

14.
J Orthop Surg Res ; 13(1): 23, 2018 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-29386035

RESUMO

BACKGROUND: Polyether-ether-ketone (PEEK), cobalt-chromium-molybdenum (CoCrMo), and highly cross-linked polyethylene (HXLPE) are biomaterials used in orthopedic implants; their wear particles are considered to induce peri-implant osteolysis. We examined whether different particle types induce the same degree of peri-implant osteolysis. METHODS: Forty female rabbits were randomly divided into four groups-the control group (n = 10), which received implantation operation and sham operation at 1 month postoperation; three experimental groups (n = 10 in each group), which received implantation operation along with administration of 0.1 mL of particle suspension (approximately 1.0 × 108 PEEK, CoCrMo, or HXLPE wear particles) into the knee joint at 1 month postoperation. All rabbits were sacrificed at 2 months postoperation. The synovium was removed and histologically assessed. The distal femurs with the implants were analyzed via micro-computed tomography (CT) and hard tissue biopsy. RESULTS: The average size of almost 90% of the particles was < 5 µm, indicating no significant difference in the three particle types. IL-1ß, IL-8, TNFα, RANKL, and MCP-1 expression in PEEK and CoCrMo groups was high, while that in the HXLPE group was low. The bone density (BD) and bone volume/total volume (BV/TV) of the porous structures (part of the implants in all groups) in experimental groups did not decrease markedly (p > 0.05), while BD in the peripheral regions in experimental groups decreased markedly compared to control groups (p < 0.05). BV/TV in the peripheral regions was significantly decreased in PEEK and CoCrMo groups when compared to control group (p < 0.05), while no significant difference was noted between HXLPE and control groups (p > 0.05). The changes in BV observed in the hard tissue sections were consistent with those noted in the micro-CT findings. CONCLUSION: PEEK, CoCrMo, and HXLPE wear particles (approximately having the same size and doses) induce peri-implant osteolysis to a different degree: HXLPE particles induce peri-implant osteolysis to a mild degree, while PEEK and CoCrMo particles caused significant peri-implant osteolysis. In case of a porous implant, osteolysis occurred primarily in the peripheral region, rather than in the porous structures. Our findings would be helpful for implant designers to choose friction pairs in orthopedic components.


Assuntos
Implantes Experimentais/efeitos adversos , Cetonas/toxicidade , Osteólise/induzido quimicamente , Polietilenoglicóis/toxicidade , Polietileno/toxicidade , Titânio/toxicidade , Vitálio/toxicidade , Animais , Materiais Biocompatíveis/metabolismo , Materiais Biocompatíveis/toxicidade , Feminino , Cetonas/metabolismo , Articulação do Joelho/diagnóstico por imagem , Articulação do Joelho/cirurgia , Modelos Animais , Osteólise/diagnóstico por imagem , Osteólise/metabolismo , Tamanho da Partícula , Polietileno/metabolismo , Polietilenoglicóis/metabolismo , Porosidade , Coelhos , Titânio/metabolismo , Vitálio/metabolismo
15.
Artif Organs ; 42(8): E204-E214, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29435992

RESUMO

Polyether-ether-ketone (PEEK) is a potential alternative to metal alloys for use in the orthopedic implants; however, an in vivo study in an appropriate animal model is essential and has not yet been initiated. The aim of the present study was to gather some preliminary evidence regarding the performance and safety of a cemented PEEK-based knee replacement device in a goat model. Fifteen adult goats were randomly divided into two groups; the control group (n = 5), which received a sham operation, and the experimental group (n = 10), which received a total knee arthroplasty with a PEEK-based knee replacement device. The animals were sacrificed at 12 (control n = 5; experimental n = 5) or 24 weeks (experimental n = 5). Blood parameter measurements and radiographs of the knee joints were obtained. The synovium and main organs were removed and histologically assessed. The knee joints with the prosthesis were analyzed via micro-computed tomography and laser confocal microscopy. There was no occurrence of implant fracture or prosthesis sinking during the 24 weeks of radiological observations, except for one case of prosthesis dislocation at 4 weeks. There was a 6% decrease in femoral bone density (BD) at 12 weeks, but no further decrease by 24 weeks. No changes in BD were observed in the tibial ends. The bulk implant was biocompatible in terms of histological analysis of the local synovium and organs. There were no optical scratches on the surface of the retrieved components; the femoral component surface was rougher, while the tibial insert was smoother after 24 weeks. The novel PEEK-based knee replacement device in a goat model was feasible and safe; however, prior to use in humans, further studies concerning PEEK high load-bearing implant designs should be carried out to expand on our results.


Assuntos
Artroplastia do Joelho/instrumentação , Cimentos para Ossos/farmacologia , Fêmur/cirurgia , Articulações/cirurgia , Cetonas/química , Prótese do Joelho , Polietilenoglicóis/química , Tíbia/cirurgia , Animais , Artroplastia do Joelho/efeitos adversos , Densidade Óssea , Estudos de Viabilidade , Fêmur/diagnóstico por imagem , Fêmur/patologia , Fêmur/fisiopatologia , Cabras , Articulações/diagnóstico por imagem , Articulações/patologia , Articulações/fisiopatologia , Teste de Materiais , Microscopia Confocal , Modelos Animais , Dados Preliminares , Desenho de Prótese , Tíbia/diagnóstico por imagem , Tíbia/patologia , Tíbia/fisiopatologia , Fatores de Tempo , Microtomografia por Raio-X
16.
Water Res ; 123: 361-368, 2017 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-28686938

RESUMO

Microbial degradation of estrogenic compounds can be affected by the nitrogen source and background carbon in the environment. However, the underlying mechanisms are not well understood. The objective of this study was to elucidate the molecular mechanisms of estrone (E1) biodegradation at the protein level under various background nitrogen (nitrate or ammonium) and carbon conditions (no background carbon, acetic acid, or humic acid as background carbon) by a newly isolated bacterial strain. The E1 degrading bacterial strain, Hydrogenophaga atypica ZD1, was isolated from river sediments and its proteome was characterized under various experimental conditions using quantitative proteomics. Results show that the E1 degradation rate was faster when ammonium was used as the nitrogen source than with nitrate. The degradation rate was also faster when either acetic acid or humic acid was present in the background. Proteomics analyses suggested that the E1 biodegradation products enter the tyrosine metabolism pathway. Compared to nitrate, ammonium likely promoted E1 degradation by increasing the activities of the branched-chain-amino-acid aminotransferase (IlvE) and enzymes involved in the glutamine synthetase-glutamine oxoglutarate aminotransferase (GS-GOGAT) pathway. The increased E1 degradation rate with acetic acid or humic acid in the background can also be attributed to the up-regulation of IlvE. Results from this study can help predict and explain E1 biodegradation kinetics under various environmental conditions.


Assuntos
Estrona/genética , Proteômica , Biodegradação Ambiental , Carbono , Monitoramento Ambiental , Estrona/análise , Nitrogênio/química
17.
BMC Musculoskelet Disord ; 18(1): 166, 2017 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-28427385

RESUMO

BACKGROUND: The cross-sectional morphology of the prosthetic knee is crucial to understanding patellar motion and quadriceps strength after total knee arthroplasty. However, few comparative evaluations of the cross-sectional morphology of the femoral trochlea have been performed in the native knee and currently available femoral implants, and the relationship between the trochlear anatomy of prosthetic components and post-operative patellofemoral complications remains unclear. We aimed to investigate the differences in cross-sectional morphology of the femoral trochlea between native knees and prosthetic femoral components. METHODS: Virtual total knee arthroplasty was performed, whereby four different femoral components (medial-pivot, Triathlon, NRG and NexGen) were virtually superimposed onto three-dimensional models of 42 healthy femurs. The following morphological parameters were measured in three cross-sections (0, 45 and 90°) of the femoral trochlea: sulcus height, lateral tilt angle, medial tilt angle and sulcus angle. Only statistically significant differences are described further (p < 0.05). RESULTS: In the 0° cross-section, sulcus height was smaller in the native knee than in the Triathlon, NRG and NexGen components; all prosthetic components had smaller lateral tilt angles and larger medial tilt angles. In the 45° cross-section, sulcus height was larger in the native knee than in the medial-pivot, Triathlon and NexGen components; both lateral and medial tilt angles were smaller in the prosthetic components. In the 90° cross-section, sulcus height was smaller in the native knee than in the medial-pivot component; all prosthetic components had a larger lateral tilt angle and smaller medial tilt angle. In all cross-sections, the sulcus angle was smaller in the native knee. CONCLUSIONS: The discrepancy between native and prosthetic trochlear geometries suggests altered knee mechanics after total knee arthroplasty, but further cadaveric, computational or fluoroscopic investigations are necessary to clarify the implications of this observation. Our findings can be used to optimize biomechanical guidelines for total knee arthroplasty (patellar resurfacing or non-resurfacing) in Chinese individuals so as to decrease the risk of patellar lateral dislocation, to maintain stability and to optimize extensor kinematics.


Assuntos
Prótese do Joelho , Articulação Patelofemoral/anatomia & histologia , Adulto , Artroplastia do Joelho , Feminino , Voluntários Saudáveis , Humanos , Imagem Tridimensional , Masculino , Pessoa de Meia-Idade , Articulação Patelofemoral/diagnóstico por imagem
18.
BMC Musculoskelet Disord ; 18(1): 4, 2017 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-28061849

RESUMO

BACKGROUND: Our study aimed to investigate whether geometrical features (size, shape, or alignment parameters) of the femoral condyle affect the morphology of the trochlear groove. METHODS: Computed tomography models of 195 femurs (97 and 98 knees from male and female subjects, respectively) were reconstructed into three-dimensional models and categorised into four types of trochlear groove morphology based on the position of the turning point in relation to the mechanical axis (types 45°, 60°, 75°, and 90°). Only subjects with healthy knees were included, whereas individuals with previous knee trauma or knee pain, soft tissue injury, osteoarthritis, or other chronic diseases of the musculoskeletal system were excluded. The size parameters were: radius of the best-fit cylinder, anteroposterior dimension of the lateral condyles (AP), and distal mediolateral dimension (ML). The shape parameters were: aspect ratio (AP/ML), arc angle, and proximal- and distal- end angles. The alignment parameters were: knee valgus physiologic angle (KVPA), mechanical medial distal femoral angle (mMDFA), and hip-knee-ankle angle (HKA). All variables were measured in the femoral condyle models, and the means for each groove type were compared using one-way analysis of variance. RESULTS: No significant difference among groove types was observed regarding size parameters. There were significant differences when comparing type 45° with types 60°, 75°, and 90° regarding aspect ratio and distal-end angle (p < 0.05), but not regarding proximal-end angle. There were significant differences when comparing type 90° with types 45°, 60°, and 75° regarding KVPA, mMDFA, and HKA (p < 0.05). CONCLUSION: Among size, shape, and alignment parameters, the latter two exhibited partial influence on the morphology of the trochlear groove. Shape parameters affected the trochlear groove for trochlear type 45°, for which the femoral condyle was relatively flat, whereas alignment parameters affected the trochlear groove for trochlear type 90°, showing that knees in type 90° tend to be valgus. The morphometric analysis based on trochlear groove classification may be helpful for the future design of individualized prostheses.


Assuntos
Grupo com Ancestrais do Continente Asiático , Fêmur/diagnóstico por imagem , Imagem Tridimensional/métodos , Articulação do Joelho/diagnóstico por imagem , Modelos Anatômicos , Tomografia Computadorizada por Raios X/métodos , Adulto , Feminino , Fêmur/anatomia & histologia , Humanos , Articulação do Joelho/anatomia & histologia , Masculino , Pessoa de Meia-Idade
19.
Knee Surg Sports Traumatol Arthrosc ; 25(10): 3163-3170, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27395356

RESUMO

PURPOSE: This study aimed to investigate the natural morphology of the femoral trochlear groove based on quantitative measurement. METHODS: Computed tomographic femur models of 50 male and 50 female healthy Chinese adults (30-60 years) were analysed using three-dimensional software. Coaxial cutting planes (15° increments) rotating about the trochlear groove axis from the proximal to distal point were created, followed by the deepest point of the trochlear groove marked at each cross section. The shape, position, and orientation of the trochlear groove were analysed. RESULTS: The trochlear groove was located laterally relative to the mechanical axis and consisted of the laterally oriented proximal part and medially oriented distal part. Based on the turning points located on different cross sections, the trochlear groove was classified into four types: types 45°, 60°, 75°, and 90°. The mediolateral position relative to the mechanical axis was types 45°, 60°, 75°, and 90°, from the lateral to medial side, while the distal parts of them extended along the same path. The orientation of the trochlear groove was relatively consistent and smooth, which oriented at approximately 1° medially between two adjacent segments, except at approximately 10° medially at the turning point. CONCLUSION: The trochlear groove tracking varies greatly amongst a population that is mainly categorized into four types. This study may be helpful for better understanding of the natural trochlear groove anatomy, prosthetic design modification, and provide the reference value for studying patellofemoral diseases such as patellar maltracking and trochlear dysplasia. LEVEL OF EVIDENCE: Prospective study, Level II.


Assuntos
Fêmur/anatomia & histologia , Imagem Tridimensional , Modelos Anatômicos , Articulação Patelofemoral/anatomia & histologia , Tomografia Computadorizada por Raios X , Adulto , Feminino , Fêmur/diagnóstico por imagem , Voluntários Saudáveis , Humanos , Prótese do Joelho , Masculino , Pessoa de Meia-Idade , Articulação Patelofemoral/diagnóstico por imagem , Estudos Prospectivos , Desenho de Prótese
20.
Int J Pharm ; 505(1-2): 223-33, 2016 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-27034000

RESUMO

Supercritical fluid assisted atomization introduced by a hydrodynamic cavitation mixer (SAA-HCM) was proposed as a green technique to fabricate insulin-loaded dry powders for inhalation administration. N-trimethyl chitosan (TMC), a polymeric mucoadhesive absorption enhancer, was synthesized and successfully micronized from aqueous solution using SAA-HCM. The prepared well-defined spherical TMC microparticles with preserved structure and thermal stability were potential carriers for delivery of proteins. Then, insulin-loaded TMC microparticles with high loading efficiency were coprecipitated from aqueous solutions using SAA-HCM without use of any organic solvents. The polymer/protein ratio revealed to be a factor influencing the particle morphology, and non-coalescing composite microparticles in amorphous state mainly ranging from 1µm to 5µm could be obtained in this work. Aerodynamic properties were assessed by next generation impactor (NGI) and the mass median aerodynamic diameter (MMAD) lied inside the inhalable range of 1-5µm, while fine particle fraction (FPF) reached above 60%. The structural integrity of encapsulated insulin was confirmed by HPLC, circular dichroism and fluorescence spectroscopy. In vivo study demonstrated that TMC could enhance the absorption and bioavailability of the pulmonarily administered insulin formulation for SD rats. These results suggest that TMC microparticles could be efficiently prepared as a promising vehicle for drug delivery, and SAA-HCM is a promising technique to prepare inhalable polymer/protein composite dry powders.


Assuntos
Quitosana/química , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Insulina/administração & dosagem , Administração por Inalação , Animais , Química Farmacêutica/métodos , Cromatografia Líquida de Alta Pressão , Dicroísmo Circular , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/química , Hipoglicemiantes/farmacocinética , Insulina/química , Insulina/farmacocinética , Masculino , Microesferas , Nebulizadores e Vaporizadores , Tamanho da Partícula , Pós , Ratos , Ratos Sprague-Dawley , Espectrometria de Fluorescência
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