Cementless unicompartmental knee replacement allows early return to normal activity

Background: Physical activity and regular participation in recreational sports gain importance in patients’ lifestyle after knee arthroplasty. Cementless unicompartimental Knee replacement with the Oxford System has been introduced into clinical routine. Currently there is no data reporting on the physical activity, return to sports rate and quality of live after medial cementless Oxford Unicompartimental Knee Replacement (OUKR). Methods: This retrospective cohort study reports on the functional outcome of the first 27 consecutive patients (30 knees) that were consecutively treated with a cementless medial OUKR between 2007 and 2009 in our hospital. Physical activity and quality of life were measured using the Tegner-Score, the UCLA-Activity Score, the Schulthess Clinical Activity Questionnaire and the SF-36 Score. The patients’ satisfaction with the outcome was measured using a visual analogue scale. Results: Mean age at surgery was 62.5 years. Patients showed a rapid recovery with 17 out of 27 patients returning to sports within 3 months, 24 within 6 months after surgery. The Return-to-activity-rate was 100%. 10 out of 27 patients showed a high activity level (UCLA ≥7 points) with a mean postoperative UCLA-Score of 6.1 points. Conclusions: Patients recover rapidly after cementless OUKR with a return to sports rate of 100% and patients are able to participate in high impact sports disciplines

Fluorescence activated enrichment of CD146+ cells during expansion of human bone-marrow derived mesenchymal stromal cells augments proliferation and GAG/DNA content in chondrogenic media

Background: While numerous subpopulations of BM-MSCs have been identified, the relevance of these findings regarding the functional properties remains mostly unclear. With regards to attempts of enhancing differentiation results by preselecting certain MSC subtypes, we have evaluated the efficiency of CD146 purification during expansion, and evaluated whether these measures enhanced MSC differentiation results. Methods: Human MSCs were derived from bone marrow of six donors and cultured in two different culture media. After P1, MSCs were purified by either magnetic or fluorescence sorting for CD146, with unsorted cells as controls. Growth characteristics and typical MSC surface markers were assessed from P0 to P3. After P3, chondrogenic, osteogenic and adipogenic differentiation potential were assessed. Results: Despite a high variability of CD146 expression among the donors, fluorescence sorting significantly increased the number of CD146+ cells compared to control MSCs, while magnetic sorting led to a lesser enrichment. Osteogenic and adipogenic differentiation potential was not affected by the sorting process. However, FACS-sorted cells showed significantly increased GAG/DNA content after chondrogenic differentiation compared to control MSCs. Conclusion: FACS sorting of CD146+ cells was more efficient than magnetic sorting. The underlying mechanism of increased GAG/DNA content after enrichment during expansion remains unclear, but may be linked to increased proliferation rates in these cells

Cortical hypertrophy with a short, curved uncemented hip stem does not have any clinical impact during early follow-up

Background: Short stems have become more and more popular for cementless total hip arthroplasty in the past few years. While conventional, uncemented straight stems for primary total hip arthroplasty (THA) have shown high survival rates in the long term, it is not known whether uncemented short stems represent a reasonable alternative. As cortical hypertrophy has been reported for short stems, the aim of this study was to determine the radiographic prevalence of cortical hypertrophy and to assess the clinical outcome of a frequently used short, curved hip stem. Methods: We retrospectively studied the clinical and radiographic results of our first 100 consecutive THAs (97 patients) using the Fitmore® hip stem. Mean age at the time of index arthroplasty was 59 years (range, 19 – 79 years). Clinical outcome and radiographic results were assessed with a minimum follow-up of 2 years, and Kaplan-Meier survivorship analysis was used to estimate survival for different endpoints. Results: After a mean follow-up of 3.3 years (range, 2.0 – 4.4 years), two patients (two hips) had died, and three patients (four hips) were lost to follow-up. Kaplan-Meier analysis estimated a survival rate of 100 % at 3.8 years, with revision for any reason as the endpoint. No femoral component showed radiographic signs of loosening. No osteolysis was detected. Cortical hypertrophy was found in 50 hips (63 %), predominantly in Gruen zone 3 and 5. In the cortical hypertrophy group, two patients (two hips; 4 %) reported some thigh pain in combination with pain over the greater trochanter region during physical exercise (UCLA Score 6 and 7). There was no significant difference concerning the clinical outcome between the cortical hypertrophy and no cortical hypertrophy group. Conclusions: The survival rate and both clinical and the radiographic outcome confirm the encouraging results for short, curved uncemented stems. Postoperative radiographs frequently displayed cortical hypertrophy but it had no significant effect on the clinical outcome in the early follow-up. Further clinical and radiographic follow-up is necessary to detect possible adverse, long-term, clinical effects of cortical hypertrophy

The Role of a Double Molecular Anchor on the Mobility and Self-Assembly of Thiols on Au(111): The Case of Mercaptobenzoic Acid

The dynamics of the self-assembly process of thiol molecules on Au(111) is affected by the interplay between molecule–substrate and molecule–molecule interactions. Therefore, it is interesting to explore the effect of a second anchor to the gold surface, in addition to the S atom, on both the order and the feasibility of phase transitions in self-assembled monolayers. To assess the role of an additional O anchor, we have compared the adsorption of two mercaptobenzoic acid isomers, 2-mercaptobenzoic acid (2-MBA) and 4-mercaptobenzoic acid (4-MBA), on Au(111). Results from scanning tunneling microscopy, X-ray photoelectron spectroscopy, electrochemical techniques, and density functional theory calculations show that the additional O anchor in 2-MBA hinders surface mobility, reducing domain size and impeding the molecular reorganization involved in phase transition to denser phases on the Au(111) substrates. This knowledge can help to predict the range order and molecular density of the thiol SAM depending on the chemical structure of the adsorbate.Fil: Rodríguez González, Miriam C.. Universidad de La Laguna; EspañaFil: Carro, Pilar. Universidad de La Laguna; EspañaFil: Pensa, Evangelina Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Vericat, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Salvarezza, Roberto Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Hernández Creus, Alberto. Universidad de La Laguna; Españ

Grain Structure Evolution of Al−Cu Alloys in Powder Bed Fusion with Laser Beam for Excellent Mechanical Properties

Powder Bed Fusion with Laser Beam of Metals (PBF-LB/M) is one of the fastest growing technology branches. More and more metallic alloys are being qualified, but processing of aluminum wrought alloys without cracks and defects is still challenging. It has already been shown that small parts with low residual porosity can be produced. However, suffering from microscopic hot cracks, the fracture behavior has been rather brittle. In this paper different combinations of temperature gradients and solidification rates are used to achieve specific solidification conditions in order to influence the resulting microstructure, as well as internal stresses. By this approach it could be shown that EN AW-2024, an aluminum-copper wrought alloy, is processable via PBF-LB/M fully dense and crack-free with outstanding material properties, exceeding those reported for commonly manufactured EN AW-2024 after T4 heat treatment

Construcción del género y sexualidad en la primera infancia: rol de la matrona en Chile

Objetivo: Identificar los elementos asociados a la construcción del género en la primera infancia y determinar las intervenciones educativas en salud sexual de la matrona en Chile. Método: Revisión bibliográfica en diferentes bases de datos académicas (CINAHL, PubMed, Web of Science, LILACS, Dialnet y Scielo), complementada con sitios web institucionales de Chile. Resultados: Emergieron cuatro categorías centrales: 1) contexto familiar; 2) contexto escolar; 3) contexto social, y 4) rol del profesional matrón/matrona en las intervenciones educativas en salud sexual. Conclusión: La construcción del género en la primera infancia se produce en contextos familiares a través de los cuidadores principales: en contextos educativos mediante la función docente, y en contextos sociales a través de los medios de comunicación y actividades lúdicas. Sin embargo, los contextos familiares y educativos refieren no estar suficientemente preparados para abordar la sexualidad en esta etapa. Aunque el profesional matrón/matrona no ha podido involucrarse aún en la primera infancia, a pesar de lo señalado por las entidades nacionales, su rol puede ser fundamental, tanto por su preparación académica como por su experiencia técnica

Impact of c-MYC expression on proliferation, differentiation, and risk of neoplastic transformation of human mesenchymal stromal cells

Background: Mesenchymal stromal cells isolated from bone marrow (MSC) represent an attractive source of adult stem cells for regenerative medicine. However, thorough research is required into their clinical application safety issues concerning a risk of potential neoplastic degeneration in a process of MSC propagation in cell culture for therapeutic applications. Expansion protocols could preselect MSC with elevated levels of growth-promoting transcription factors with oncogenic potential, such as c-MYC. We addressed the question whether c-MYC expression affects the growth and differentiation potential of human MSC upon extensive passaging in cell culture and assessed a risk of tumorigenic transformation caused by MSC overexpressing c-MYC in vivo. Methods: MSC were subjected to retroviral transduction to induce expression of c-MYC, or GFP, as a control. Cells were expanded, and effects of c-MYC overexpression on osteogenesis, adipogenesis, and chondrogenesis were monitored. Ectopic bone formation properties were tested in SCID mice. A potential risk of tumorigenesis imposed by MSC with c-MYC overexpression was evaluated. Results: C-MYC levels accumulated during ex vivo passaging, and overexpression enabled the transformed MSC to significantly overgrow competing control cells in culture. C-MYC-MSC acquired enhanced biological functions of c-MYC: its increased DNA-binding activity, elevated expression of the c-MYC-binding partner MAX, and induction of antagonists P19ARF/P16INK4A. Overexpression of c-MYC stimulated MSC proliferation and reduced osteogenic, adipogenic, and chondrogenic differentiation. Surprisingly, c-MYC overexpression also caused an increased COL10A1/COL2A1 expression ratio upon chondrogenesis, suggesting a role in hypertrophic degeneration. However, the in vivo ectopic bone formation ability of c-MYC-transduced MSC remained comparable to control GFP-MSC. There was no indication of tumor growth in any tissue after transplantation of c-MYC-MSC in mice. Conclusions: C-MYC expression promoted high proliferation rates of MSC, attenuated but not abrogated their differentiation capacity, and did not immediately lead to tumor formation in the tested in vivo mouse model. However, upregulation of MYC antagonists P19ARF/P16INK4A promoting apoptosis and senescence, as well as an observed shift towards a hypertrophic collagen phenotype and cartilage degeneration, point to lack of safety for clinical application of MSC that were manipulated to overexpress c-MYC for their better expansion