Protective effects of tumor necrosis factor-α blockade by adalimumab on articular cartilage and subchondral bone in a rat model of osteoarthritis

We aimed to investigate the effects of an anti-tumor necrosis factor-α antibody (ATNF) on cartilage and subchondral bone in a rat model of osteoarthritis. Twenty-four rats were randomly divided into three groups: sham-operated group (n=8); anterior cruciate ligament transection (ACLT)+normal saline (NS) group (n=8); and ACLT+ATNF group (n=8). The rats in the ACLT+ATNF group received subcutaneous injections of ATNF (20 μg/kg) for 12 weeks, while those in the ACLT+NS group received NS at the same dose for 12 weeks. All rats were euthanized at 12 weeks after surgery and specimens from the affected knees were harvested. Hematoxylin and eosin staining, Masson's trichrome staining, and Mankin score assessment were carried out to evaluate the cartilage status and cartilage matrix degradation. Matrix metalloproteinase (MMP)-13 immunohistochemistry was performed to assess the cartilage molecular metabolism. Bone histomorphometry was used to observe the subchondral trabecular microstructure. Compared with the rats in the ACLT+NS group, histological and Mankin score analyses showed that ATNF treatment reduced the severity of the cartilage lesions and led to a lower Mankin score. Immunohistochemical and histomorphometric analyses revealed that ATNF treatment reduced the ACLT-induced destruction of the subchondral trabecular microstructure, and decreased MMP-13 expression. ATNF treatment may delay degradation of the extracellular matrix via a decrease in MMP-13 expression. ATNF treatment probably protects articular cartilage by improving the structure of the subchondral bone and reducing the degradation of the cartilage matrix.

Delivery of the Sox9 gene promotes chondrogenic differentiation of human umbilical cord blood-derived mesenchymal stem cells in an in vitro model

SRY-related high-mobility-group box 9 (Sox9) gene is a cartilage-specific transcription factor that plays essential roles in chondrocyte differentiation and cartilage formation. The aim of this study was to investigate the feasibility of genetic delivery of Sox9 to enhance chondrogenic differentiation of human umbilical cord blood-derived mesenchymal stem cells (hUC-MSCs). After they were isolated from human umbilical cord blood within 24 h after delivery of neonates, hUC-MSCs were untreated or transfected with a human Sox9-expressing plasmid or an empty vector. The cells were assessed for morphology and chondrogenic differentiation. The isolated cells with a fibroblast-like morphology in monolayer culture were positive for the MSC markers CD44, CD105, CD73, and CD90, but negative for the differentiation markers CD34, CD45, CD19, CD14, or major histocompatibility complex class II. Sox9 overexpression induced accumulation of sulfated proteoglycans, without altering the cellular morphology. Immunocytochemistry demonstrated that genetic delivery of Sox9 markedly enhanced the expression of aggrecan and type II collagen in hUC-MSCs compared with empty vector-transfected counterparts. Reverse transcription-polymerase chain reaction analysis further confirmed the elevation of aggrecan and type II collagen at the mRNA level in Sox9-transfected cells. Taken together, short-term Sox9 overexpression facilitates chondrogenesis of hUC-MSCs and may thus have potential implications in cartilage tissue engineering.

La orientación empática en los estudiantes de medicina humana de la Universidad de San Martin de Porres / Empathetic orientation of the medical students from San Martin de Porres University

OBJETIVO: Conocer el nivel de orientación empática en los estudiantes de medicina de la Universidad San Martín de Porres. MATERIAL Y MÉTODOS: Es una investigación observacional, transversal descriptivo, realizada entre los meses de marzo y junio del año 2010. Participaron 193 alumnos de un universo de 1920, correspondientes a los años I, II, III, IV, V y VI de la carrera de Medicina Humana de la Universidad de San Martín de Porres. Se aplicó la Escala de Empatía Médica de Jefferson (EEMJ). Para el análisis de datos se emplearon medios descriptivos de frecuencia, porcentajes y desviaciones estándares. RESULTADOS: Los estudiantes de IV año obtuvieron el mayor puntaje (6,1) de orientación empática, sin embargo el I año obtuvo el menor puntaje (5,5). Las mujeres tuvieron un mayor puntaje de orientación empática que los hombres, 5,9 y 5,8 respectivamente. El grupo etario con mayor puntaje (5,9) de orientación empática fue el grupo de 25-28 años. CONCLUSIONES:Los alumnos que están en los niveles intermedios de la carrera de medicina humana (III y IV año de medicina), las mujeres y el grupo etario de 25 û 28 años obtuvieron mayores puntuaciones en la Escala de Empatía Médica de Jefferson...

OBJECTIVE: To know the empathetic orientation of the medical students from San Martin de Porres University. MATERIAL AND METHODS: This is an observational, cross-sectional descriptive study, carried out between the months on March and June, 2010. 193 out of 1920 students participated, who belonged to the levels I, II, II, IV, V and VI. The Jefferson Scale of Physician Empathy (JSPE) was applied. For the data analysis used descriptive means of frequency, percentages and standard deviations. RESULTS: The Fourth yearÆs students obtained the highest score (6,1) in the empathic guidance, however the first yearÆs students had the lowest score (5,5). Women had a higher score than men empathetic orientation, 5,9 and 5,8 respectively. The age group with the highest score (5,9) empathic orientation was the group of 25-28 years. CONCLUSIONS: The students who are level intermediate of human medicine carrier (III and IV levels of medicine), the female and the group of 25 to 28 years had the highest score in The Jefferson Scale Physician Empathy.