[Genistein loaded by PRF improved bone healing in obese mice].

PURPOSE: To clarify the effect of genistein(GEN) on osteogenic differentiation and explore the effect of GEN loaded by platelet-rich fibrin (PRF) on the repair process of bone defects in obese mice. METHODS: In in vitro experiments, the effect of GEN(0, 0.1, 1, 10, 50 µmol/L) on the proliferation of mouse embryonic osteoblast precursor cells (MC3T3-E1) was determined by CCK 8. Alkaline phosphatase(ALP) staining and quantitative detection of ALP activity were performed to determine the changes of ALP activity in cells; RNA and protein expression levels of ALP, osteopontin (OPN) and osteocalcin (OCN) were detected by quantitative real-time PCR(qRT-PCR) and Western blot. Alizarin red staining was used to define the effect of GEN on mineralization of MC3T3-E1. To verify the feasibility of the PRF drug loading, the ultrastructure of PRF was subsequently observed under SEM. In in vivo experiments, obese C57 mouse models were established by high-fat diet feeding. On this basis, skull defect models with a diameter of 2.8 mm were established, and the prepared GEN/PRF complexes were placed into the bone defect area. The effects of GEN on skull defect repair in obese mice were evaluated by Micro-CT scanning and hematoxylin-eosin(H-E) staining. Statistical analysis was performed with GraphPad Prism 5.0 software package. RESULTS: CCK 8 results showed that 0.1, 1 µmol/L GEN promoted cell proliferation within 7 days(P＜0.05); 10 µmol/L GEN had no significant effect on the process of cell proliferation. From the second day, 50 µmol/L GEN significantly inhibited cell growth and showed cytotoxicity(P＜0.05). These two concentrations had similar effects in promoting cellular osteogenic differentiation. SEM results showed that PRF presented a 3-dimensional network structure, providing space for loading drug molecules. In in vivo experiments, the body weight of mice in the high-fat diet (HFD) group was 27.7% greater than that in the normal diet group(P＜0.05) and had abnormal glucose tolerance (P＜0.05). Micro-CT showed that compared with the normal diet group, the number of bone trabeculae in the femur of obese mice was decreased(P＜0.05), the distance between bone trabeculae was widened(P＜0.05), and the bone density was decreased (P＜0.05). In addition, GEN (0.1, 1.0 µmol/L) loaded by PRF increased bone volume fraction in the skull of obese mice (P＜0.05). H-E results showed that GEN/PRF promoted the healing of the bone defects. CONCLUSIONS: GEN promotes osteogenic differentiation of MC3T3-E1, and it can effectively accelerate the healing of cranial bone defects after loading with PRF in obese mice.

The relationship between jumping and sprinting performance in teenage sprinters / Relación entre el desempeño del salto y el sprint en velocistas adolescentes / Relação entre o desempenho de salto e sprint em velocistas adolescentes

ABSTRACT Objectives: This study aimed to examine the relationship between vertical jumping at forces of specific time phase and sprint performance in teenage sprinters. Methods: Fifteen male teenage sprinters (age: 14±2 years, height: 168±2 cm, weight: 61±1 kg) participated in the study. The subjects performed the following bilateral/unilateral jumps on a force platform: a) squat jump (SJ), b) unilateral SJ (USJ), c) 40cm drop jump (DJ), and d) 20cm unilateral DJ (UDJ). The 60m sprint test was administered on the second day. Brower split timers were positioned to record subjects' 5m, 10m, 50m and 60m split times. The variables for inclusion were vertical jump height, maximum force, and force output at 120ms in all jumps and sprint time measures. Results: The results of the Pearson Product Moment Correlation analysis showed that SJ120ms was correlated to 5m and USJ120ms was correlated to 10m. UDJ120ms showed a stronger correlation with 50m than DJ120ms. Although significant correlations using maximum force and height were observed, there were inconsistent results between bilateral and unilateral jumps. Conclusion: Our results highlighted that jumps that have similar form with certain force outputs at specific event timing could more precisely predict sprint performance in teenage sprinters. USJ120ms and UDJ120ms could better predict the acceleration (10m) and high-speed phase (50m) in sprint performance, respectively. Moreover, coaches and practitioners should be cautious when using only jump height or maximum force to predict sprint performance, since the results could be inaccurate when specific movement variables are not thoughtfully considered. Level of evidence III.

RESUMEN Objetivos: Este estudio tuvo como objetivo examinar la relación entre el salto vertical y la fuerza en tiempo específico y el desempeño del sprint en velocistas adolescentes. Métodos: Participaron en el estudio quince adolescentes varones velocistas (edades: 14 ± 2 años, estatura: 168 ± 2 cm, peso: 61 ± 1 kg). Los individuos realizaron los siguientes saltos bilaterales y unilaterales en una plataforma de fuerza: a) squat jump (SJ), b) SJ unilateral (USJ), c) drop jump (DJ) de 40 cm e d) DJ unilateral (UDJ) de 20 cm. La prueba de sprint de 60 m se realizó el segundo día. Los cronómetros en el entrenamiento fraccionado se ajustaron para registrar tiempos de 5 m, 10 m, 50 m y 60 m. Las variables que se incluyeron fueron la altura del salto vertical, la fuerza máxima y la salida de fuerza a 120 m en todos los saltos y mediciones del tiempo del sprint. Resultados: Los resultados del análisis de correlación producto-tiempo de Pearson revelaron que el SJ de 120 m estaba correlacionado con 5 m y el USJ de 120 m estaba correlacionado con 10 m. El UDJ de 120 m tuvo una mayor correlación con el DJ de 50 m que con el de 120 m. Aunque se observaron correlaciones significativas con la fuerza y la altura máximas, algunos resultados fueron inconsistentes entre los saltos bilaterales y unilaterales. Conclusiones: Nuestros resultados pusieron de manifiesto que los saltos con una forma similar a determinadas salidas de fuerza en un tiempo específico del evento pueden predecir con mayor precisión el desempeño en el sprint en adolescentes velocistas. El USJ de 120 m y el UDJ de 120 m pueden predecir mejor, respectivamente, la aceleración (10 m) y la fase de alta velocidad (50 m) en el desempeño del sprint. Además, los entrenadores y practicantes deben ser cautelosos a la hora de utilizar únicamente la altura del salto o la fuerza máxima para predecir el desempeño en el sprint, ya que los resultados pueden ser inexactos cuando no se tienen en cuenta con precisión las variables específicas del movimiento. Nivel de evidencia III.

RESUMO Objetivos: Este estudo teve como objetivo examinar a relação entre o salto vertical e a força em tempo específico e o desempenho de sprint em velocistas adolescentes. Métodos: Quinze adolescentes velocistas do sexo masculino (idade: 14 ± 2 anos, estatura: 168 ± 2 cm, peso: 61 ± 1 kg) participaram do estudo. Os indivíduos realizaram os seguintes saltos bilaterais e unilaterais em uma plataforma de força: a) squat jump (SJ), b) SJ unilateral (USJ), c) drop jump (DJ) de 40 cm e d) DJ unilateral (UDJ) de 20cm. O teste de sprint de 60 m foi realizado no segundo dia. Os cronômetros rastreadores para treinos fracionados foram posicionados para registrar os tempos fracionados de 5 m, 10 m, 50 m e 60 m. As variáveis para inclusão foram altura do salto vertical, força máxima e saída de força a 120 m em todos os saltos e medidas de tempo do sprint. Resultados: Os resultados da análise da correlação produto-tempo de Pearson mostraram que o SJ de 120 m foi correlacionado com 5 m e USJ de 120 m foi correlacionado com 10 m. O UDJ de 120 m teve correlação mais forte com DJ de 50 m do que de 120 m. Embora tenham sido observadas correlações significativas com força e altura máximas, alguns resultados foram inconsistentes entre os saltos bilaterais e unilaterais. Conclusões: Nossos resultados destacaram que os saltos com forma semelhante a certas saídas de força no tempo específico do evento podem prever com mais precisão o desempenho no sprint em adolescentes velocistas. O USJ de 120 m e o UDJ de 120 m podem prever melhor, respectivamente, a aceleração (10 m) e a fase de alta velocidade (50 m) no desempenho no sprint. Além disso, treinadores e praticantes devem ser cautelosos ao usar apenas a altura do salto ou a força máxima para prever o desempenho no sprint, uma vez que os resultados podem ser imprecisos quando variáveis específicas do movimento não forem consideradas com precisão. Nível de evidência III.

[Comparison of early clinical outcomes between mobile-bearing and fixed-bearing total knee arthroplasty for the valgus knee].

OBJECTIVE: To compare the early clinical outcomes of primary total knee arthroplasty in the valgus knee between mobile-bearing prosthesis and fixed-bearing prosthesis. METHODS: From January 2011 to December 2013, 17 patients (23 knees) treated by the same surgeon were selected for a retrospective study in the First Hospital of Jilin University, including 2 males and 15 females with a mean age of 61.5 years old (48 to 75 years). The pre-operative diagnosis included osteoarthritis (14 patients, 19 knees) and rheumatoid arthritis (3 patients, 4 knees). The patients with valgus deformity were divided into group A and group B. The patients in group A were treated with the fixed-bearing prosthesis (9 patients, 12 knees), and the patients in group B were treated with the mobile-bearing prosthesis (8 patients, 11 knees). The Knee Society Score (KSS), Hosptial for Special Surgery (HSS), Western Ontario MacMaster (WOMAC), the range of motion (ROM) and femorotibial angle were collected at pre-operation and post-operation follow-up for statistical analysis. RESULTS: All the patients were followed up, and the duration ranged from 6 to 36 months (mean 25 months). The valgus deformity was corrected in all patients, and there were significant differences for all patients between pre-operation and post-operation at the latest follow-up with regard to the KSS knee score, function score, HSS score, WOMAC score, ROM and femorotibial angle (P<0.01). There were no significant differences in KSS knee score, function score, HSS score, WOMAC score, improvement in ROM and femorotibial angle between two groups at the latest follow-up. However there were significant differences in ROM (P<0.05) between fixed-bearing group (101.8±8.8)° and mobile-bearing group (108.4±7.2)° at the latest follow-up. No case with spin-out of mobile bearing was observed. There were no complications in any patient, such as infection, common peroneal nerve injury, dislocation and instability. The X-ary imaging showed no osteolysis or implant loosening. CONCLUSION: The early clinical outcomes of primary total knee arthroplasty by using mobile-bearing prosthesis and fixed-bearing prosthesis are satisfactory for the treatment of the valgus knee, and the short term clinical outcomes of mobile-bearing TKA and fixed-bearing TKA are similar.

[Application of microwave irradiation technology to the field of pharmaceutics].

Microwaves can be directly transformed into heat inside materials because of their ability of penetrating into any substance. The degree that materials are heated depends on their dielectric properties. Materials with high dielectric loss are more easily to reach a resonant state by microwaves field, then microwaves can be absorbed efficiently. Microwave irradiation technique with the unique heating mechanisms could induce drug-polymer interaction and change the properties of dissolution. Many benefits such as improving product quality, increasing energy efficiency and reducing times can be obtained by microwaves. This paper summarized characteristics of the microwave irradiation technique, new preparation techniques and formulation process in pharmaceutical industry by microwave irradiation technology. The microwave technology provides a new clue for heating and drying in the field of pharmaceutics.