Oddershedeeaton9417

Axial malignant bone tumours are rare in children and adolescents, and their prognosis is still relatively poor due to non-specific symptoms, such as back or groin pain, which may result in late hospital presentation. Therefore, it is very important to raise awareness regarding this pathology.

We performed a narrative review, including scientific publications published in English. We searched Medline and Google Scholar databases for information on the incidence and prognosis of axial malignant bone tumours in children and adolescents (< 18 years). Outcomes of different surgical management strategies and reconstruction options were assessed.

The incidence of primary malignant bone tumours before the age of 18 years is approximately five per one million population; around 25% of these tumours are located in the axial skeleton. With a five-year survival rate of 50%, tumours in an axial location (chest cage, spine, pelvis) are associated with a poorer prognosis than tumours in more peripheral locations.

excision with clear margins has been shown to improve local control and overall survival, even though obtaining adequate surgical margins is difficult due to the close location of large neurovascular structures and other major organs. Spinal reconstruction options include instrumented fusion with allograft or expandable cage. Pelvic reconstruction is needed in internal hemipelvectomy, and the options include biological, endoprosthetic reconstructions, hip transposition, arthrodesis or creation of pseudoarthrosis and lumbopelvic instrumentation.

Early diagnosis, a timely adequate multidisciplinary management, appropriate

excision, and reconstruction improve survival and quality of life in these patients.

V.

V.

Osteosarcoma and Ewing sarcoma are the most frequent malignant bone tumours of childhood and adolescence. This review summarizes the oncologist's view of these diseases and their treatment.

A non-systematic literature review was performed, the personal impressions and experience of the authors is described.

Local therapy and chemotherapy, each on their own, will not cure patients with malignant bone sarcomas. Together, they present a highly efficacious combination. While the most effective drugs were defined decades ago, progress since then has been limited. It is hoped that substances shown to be active in relapsed disease will be forwarded into even more efficacious frontline treatments. Good palliative therapy is necessary when cure is no longer an option.

Close interdisciplinary collaboration is the key to successful treatment of bone sarcomas in paediatric patients.

Close interdisciplinary collaboration is the key to successful treatment of bone sarcomas in paediatric patients.

The main challenge in reconstruction after malignant bone tumour resection in young children remains how and when growth-plates can be preserved and which options remain if impossible.

We describe different strategies to assure best possible long-term function for young children undergoing resection of malignant bone tumours.

Different resources are available to treat children with malignant bones tumours a) preoperative planning simulates scenarios for tumour resection and limb reconstruction, facilitating decision-making for surgical and reconstructive techniques in individual patients; b) allograft reconstruction offers bone-stock preservation for future needs. Most allografts are intact at long-term follow-up, but limb-length inequalities and corrective/revision surgery are common in young patients; c) free vascularized fibula can be used as stand-alone reconstruction, vascularized augmentation of structural allograft or devitalized autograft. Longitudinal growth and joint remodelling potential can be preserved, if transferred with vascularized proximal physis; d) epiphysiolysis before resection with continuous physeal distraction provides safe resection margins and maintains growth-plate and epiphysis; e) 3D printing may facilitate joint salvage by reconstruction with patient-specific instruments. Very short stems can be created for fixation in (epi-)metaphysis, preserving native joints; f) growing endoprosthesis can provide for remaining growth after resection of epi-metaphyseal tumours. At ten-year follow-up, limb survival was 89%, but multiple surgeries are often required; g) rotationplasty and amputation should be considered if limb salvage is impossible and/or would result in decreased function and quality of life.

Several biological and technological reconstruction options must be merged and used to yield best outcomes when treating young children with malignant bone tumours.

Level V Expert opinion.

Level V Expert opinion.

Although malignant bone tumours in children are infrequent, it is important to know how to properly diagnose and stage them, in order to establish an adequate treatment.

We present a review of the diagnostic workflow of malignant bone tumours in children, including history and clinical examination, imaging, laboratory tests and biopsy techniques. Moreover, the two most commonly used staging systems are reviewed.

History, clinical examination and laboratory tests are nonspecific for diagnosing malignant bone tumours in children. Entinostat solubility dmso Radiographs remain the mainstay for initial diagnosis, with MRI the modality of choice for local assessment and staging. Fluorine-18 labelled fluoro-deoxy-glucose-positron emission tomography scans provide a noninvasive method to assess the aggressiveness of the tumour and to rule out metastasis and is replacing the use of the bone scintigraphy. Biopsy must be always performed under the direction of the surgeon who is to perform the surgical treatment and after all diagnostic evaluation has been done. Staging systems are useful to study the extent of the tumour and its prognosis. They are expected to evolve as we better understand new molecular and genetic findings.

When a malignant bone tumour is suspected in a child, it is essential to make a correct diagnosis and referral to an experienced centre. Following an appropriate workflow for diagnosis and staging facilitates, prompt access to treatment improves outcomes.

Level V Expert opinion.

Level V Expert opinion.In the last decades, numerous stimuli-responsive polymers have been developed and investigated regarding their switching properties. In particular, thermoresponsive polymers, which form a miscibility gap with the ambient solvent with a lower or upper critical demixing point depending on the temperature, have been intensively studied in solution. For the application of such polymers in novel sensors, drug delivery systems or as multifunctional coatings, they typically have to be transferred into specific arrangements, such as micelles, polymer films or grafted nanoparticles. However, it turns out that the thermodynamic concept for the phase transition of free polymer chains fails, when thermoresponsive polymers are assembled into such sterically confined architectures. Whereas many published studies focus on synthetic aspects as well as individual applications of thermoresponsive polymers, the underlying structure-property relationships governing the thermoresponse of sterically constrained assemblies, are still poorly understood. Furthermore, the clear majority of publications deals with polymers that exhibit a lower critical solution temperature (LCST) behavior, with PNIPAAM as their main representative. In contrast, for polymer arrangements with an upper critical solution temperature (UCST), there is only limited knowledge about preparation, application and precise physical understanding of the phase transition. This review article provides an overview about the current knowledge of thermoresponsive polymers with limited mobility focusing on UCST behavior and the possibilities for influencing their thermoresponsive switching characteristics. It comprises star polymers, micelles as well as polymer chains grafted to flat substrates and particulate inorganic surfaces. The elaboration of the physicochemical interplay between the architecture of the polymer assembly and the resulting thermoresponsive switching behavior will be in the foreground of this consideration.Two or more indole molecules tailored to a single non-metal central atom, through any of their C2-7 positions are not only structurally engaging but also constitute a class of important pharmacophores. Although the body of such multi-indolyl non-metallide molecules are largely shared to the anticancer agent bis(indolyl)methane, other heteroatomic analogs also possess similar medicinal properties. This concise review will discuss various catalytic and uncatalytic synthetic strategies adopted for the synthesis of the non-ionic (non-metallic) versions of these important molecules till date.Additive manufacturing or 3D printing as an umbrella term for various materials processing methods has distinct advantages over many other processing methods, including the ability to generate highly complex shapes and designs. However, the performance of any produced part not only depends on the material used and its shape, but is also critically dependent on its surface properties. Important features, such as wetting or fouling, critically depend mainly on the immediate surface energy. To gain control over the surface chemistry post-processing modifications are generally necessary, since it's not a feature of additive manufacturing. Here, we report on the use of initiator and catalyst-free photografting and photopolymerization for the hydrophilic modification of microfiber scaffolds obtained from hydrophobic medical-grade poly(ε-caprolactone) via melt-electrowriting. Contact angle measurements and Raman spectroscopy confirms the formation of a more hydrophilic coating of poly(2-hydroxyethyl methacrylate). Apart from surface modification, we also observe bulk polymerization, which is expected for this method, and currently limits the controllability of this procedure.The use of mono-substituted malonic acid half oxyesters (SMAHOs) has been hampered by the sporadic references describing their preparation. An evaluation of different approaches has been achieved, allowing to define the best strategies to introduce diversity on both the malonic position and the ester function. A classical alkylation step of a malonate by an alkyl halide followed by a monosaponification gave access to reagents bearing different substituents at the malonic position, including functionalized derivatives. On the other hand, the development of a monoesterification step of a substituted malonic acid derivative proved to be the best entry for diversity at the ester function, rather than the use of an intermediate Meldrum acid. Both these transformations are characterized by their simplicity and efficiency, allowing a straightforward access to SMAHOs from cheap starting materials.A procedure for the enantioselective synthesis of α-substituted glutamates and pyroglutamates via a cyclopropenimine-catalyzed Michael addition of amino ester imines is described. Enantioselectivities of up to 94% have been achieved, and a variety of functional groups were found to be compatible. The impact of the catalyst structure and imine substitution is discussed. Compared to other methods, this protocol allows for a broader and more enantioselective access to pyroglutamate derivatives.