Surgical treatment of skeletal metastases in proximal tibia: a multicenter case series of 74 patients

Background and purpose - The proximal tibia is a rare site for metastatic bone disease and is a challenging anatomical site to manage due to the proximity to the knee joint and poor soft tissue envelope. We investigated implant survival and complications of different surgical strategies in the treatment of proximal tibia pathological fractures. Patients and methods - The study comprised a 4 medical center, retrospective analysis of 74 patients surgically treated for metastases of the proximal tibia. Patient records were reviewed to identify outcome, incidence, and type of complications as well as contributing factors. Results - Reconstruction techniques comprised cement-augmented osteosynthesis (n = 33), tumor prosthesis (n = 31), and total knee arthroplasty with long cemented stems (n = 10). Overall implant survival was 88% at 6 months and 1 year, and 67% at 3 years. After stratification by technique, the implant survival was 82% and 71% at 1 and 3 years with tumor prosthesis, 100% at 1 and 3 years with total knee arthroplasty, and 91% at 1 year and 47% at 3 years with osteosynthesis. Preoperative radiotherapy decreased implant survival. Complications were observed in 19/74 patients. Treatment complications led to amputation in 5 patients. Interpretation - In this study, the best results were seen with both types of prothesis reconstructions, with good implant survival, when compared with treatment with osteosynthesis. However, patients treated with tumor prosthesis showed an increased incidence of postoperative infection, which resulted in poor implant survival. Osteosynthesis with cement is a good alternative for patients with short expected survival whereas endoprosthetic replacement achieved good medium-term results.Peer reviewe

Sequence Defined Disulfide-Linked Shuttle for Strongly Enhanced Intracellular Protein Delivery

Intracellular protein transduction technology is opening the door for a promising alternative to gene therapy. Techniques have to address all critical steps, like efficient cell uptake, endolysosomal escape, low toxicity, while maintaining full functional activity of the delivered protein. Here, we present the use of a chemically precise, structure defined three-arm cationic oligomer carrier molecule for protein delivery. This carrier of exact and low molecular weight combines good cellular uptake with efficient endosomal escape and low toxicity. The protein cargo is covalently attached by a bioreversible disulfide linkage. Murine 3T3 fibroblasts could be transduced very efficiently with cargo nlsEGFP, which was tagged with a nuclear localization signal. We could show subcellular delivery of the nlsEGFP to the nucleus, confirming cytosolic delivery and expected subsequent subcellular trafficking. Transfection efficiency was concentration-dependent in a directly linear mode and 20-fold higher in comparison with HIV-TAT-nlsEGFP containing a functional TAT transduction domain. Furthermore, β-galactosidase as a model enzyme cargo, modified with the carrier oligomer, was transduced into neuroblastoma cells in enzymatically active form

85 Low-Molecular-Weight metabolites in bovine In Vitro production culture media as embryo quality markers

The need for noninvasive embryo quality assessment techniques has increased as the in vitro production of cattle embryos has become more popular and necessary in the beef and milk production industries. In this study, we assessed the metabolomic profile of embryo culture media to determine whether it is possible to evaluate differences in low-molecular-weight metabolites in the culture media composition of morula stage embryos compared with embryos that develop to the blastocyst stage. Single bovine embryos were cultured in 60-µL SOF+0.4% BSA droplets under mineral oil. Twenty microliters of culture media was removed at Day 2, 5, and 8 post-fertilization. Cultured droplets without a zygote served as the control samples. A total of 42 samples were analysed using liquid chromatography-mass spectrometry (Q-Trap 3200, Ab Sciex, Framingham, MA, USA), followed by principal component analysis. Our preliminary results indicated significant differences (P < 0.00001) in 10 low-molecular-weight compounds between the groups. Three of those compounds (588, 589, and 702 Da) were represented in higher concentrations only in embryos that advanced into the blastocyst stage. These first results could allow the identification of embryos with improved viability and give better understanding of the development of pre-implantation embryo

Low molecular weight metabolites as possible new non-invasive tool for selecting bovine in vitro produced embryos

Selecting high quality preimplantation embryo for transfer has been the most difficult task when producing embryos in vitro. To date the most used non-invasive method is based on visual observation. Developing a non-invasive method for embryo assessment is essential to have a profitable in vitro embryo production (IVP) and embryo transfer system. Molecular characterization of embryo growth media has been proposed as an complementary method to visual assessment of embryo morphology. In this study we are demonstrating a novel method, allowing sample collection at different embryo development stages, without compromising embryo quality, to determine potential viability markers for bovine IVP. Single bovine embryos were cultured in 60µl SOF+0.4% BSA droplets under mineral oil. Twenty µl of culture media was removed at day 2, 5 and 8 post-fertilization. A total of 58 samples were analyzed using liquid chromatography-mass spectrometry (Q-Trap 3200), followed by principal component analysis. Our results indicate that there are significant differences (p<0,00001) in concentrations for proline (m/z = 116), inositol (m/z of sodium adduct = 203) and citrate (m/z of sodium adduct = 215) also in the amino acid group of leucine and isoleucine (m/z = 132), phenylalanine (m/z = 165) and arginine (m/z = 211) between the normally developed and retarded in development embryo culture media. Platelet activating factor (m/z = 524) (PAF) was roughly 3 fold increased in day 5 to day 8 embryo culture media. Unfortunately the increase of PAF was not statistically significant between normally developing and retarded embryos. These results demonstrate that it is possible to remove culture media samples from droplets and not significantly affect embryo development. Applying this method for embryo selection provides a possibility to identify well-developing embryos and provides an opportunity for improving the herds genetic value

In vitro culture and non-invasive metabolic profiling of single bovine embryos

Selecting high-quality embryos for transfer has been a difficult task when producing bovine embryos in vitro. The most used non-invasive method is based on visual observation. Molecular characterisation of embryo growth media has been proposed as a complementary method. In this study we demonstrate a culture medium sampling method for identifying potential embryonic viability markers to predict normal or abnormal embryonic development. During single embryo culture, 20 µL culture media was removed at Days 2, 5 and 8 after fertilisation from the same droplet (60 µL). In all, 58 samples were analysed using liquid chromatography–mass spectrometry. We demonstrate that it is possible to remove samples from the same culture medium droplets and not significantly affect blastocyst rate (25.2%). Changes in any single low molecular weight compound were not predictive enough. Combining multiple low molecular weight signals made it possible to predict Day 2 and 5 embryo development to the blastocyst stage with an accuracy of 64%. Elevated concentrations of lysophosphatidylethanolamines (m/z = 453, 566, 588) in the culture media of Day 8 well-developing embryos were observed. Choline (104 m/z) and citrate (215 m/z) concentrations were increased in embryos in which development was retarded. Metabolic profiling provides possibilities to identify well-developing embryos before transfer, thus improving pregnancy rates and the number of calves born

A Diagnostic Algorithm for Mitochondrial Disorders in Estonian Children

Item does not contain fulltextMitochondrial disorders are a heterogeneous group of disorders affecting energy production of the body. Different consensus diagnostic criteria for mitochondrial disorders in childhood are available - Wolfson, Nijmegen and modified Walker criteria. Due to the extreme complexity of mitochondrial disorders in children, we decided to develop a diagnostic algorithm, applicable in clinical practice in Estonia, in order to identify patients with mitochondrial disorders among pediatric neonatology and neurology patients. Additionally, it was aimed to evaluate the live-birth prevalence of mitochondrial disorders in childhood. During the study period (2003-2009), a total of 22 children were referred to a muscle biopsy in suspicion of mitochondrial disorder based on the preliminary biochemical, metabolic and instrumental investigations. Enzymatic and/or molecular analysis confirmed mitochondrial disease in 5 of them - an SCO2 gene (synthesis of cytochrome c oxidase, subunit 2) defect, 2 cases of pyruvate dehydrogenase complex deficiency and 2 cases of combined complex I and IV deficiency. The live-birth prevalence for mitochondrial defects observed in our cohort was 1/20,764 live births. Our epidemiological data correlate well with previously published epidemiology data on mitochondrial diseases in childhood from Sweden and Australia, but are lower than in Finland