Anaplastic Lymphoma Kinase (ALK) in Posterior Cranial Fossa Tumors: A Scoping Review of Diagnostic, Prognostic, and Therapeutic Perspectives

Anaplastic Lymphoma Kinase (ALK) has been implicated in several human cancers. This review aims at mapping the available literature on the involvement of ALK in non-glial tumors localized in the posterior cranial fossa and at identifying diagnostic, prognostic, and therapeutic considerations. Following the PRISMA-ScR guidelines, studies were included if they investigated ALK's role in primary CNS, non-glial tumors located in the posterior cranial fossa. A total of 210 manuscripts were selected for full-text review and 16 finally met the inclusion criteria. The review included 55 cases of primary, intracranial neoplasms with ALK genetic alterations and/or protein expression, located in the posterior fossa, comprising of medulloblastoma, anaplastic large-cell lymphoma, histiocytosis, inflammatory myofibroblastic tumors, and intracranial myxoid mesenchymal tumors. ALK pathology was investigated via immunohistochemistry or genetic analysis. Several studies provided evidence for potential diagnostic and prognostic value for ALK assessment as well as therapeutic efficacy in its targeting. The available findings on ALK in posterior fossa tumors are limited. Nevertheless, previous findings suggest that ALK assessment is of diagnostic and prognostic value in medulloblastoma (WNT-activated). Interestingly, a substantial proportion of ALK-positive/altered CNS histiocytoses thus far identified have been localized in the posterior fossa. The therapeutic potential of ALK inhibition in histiocytosis warrants further investigation.

Approaches in the risk assessment of genetically modified foods by the Hellenic Food Safety Authority

Risk analysis has become important to assess conditions and take decisions on control procedures. In this context it is considered a prerequisite in the evaluation of GM food. Many consumers worldwide worry that food derived from genetically modified organisms (GMOs) may be unhealthy and hence regulations on GMO authorisations and labelling have become more stringent. Nowadays there is a higher demand for non-GM products and these products could be differentiated from GM products using the identity preservation system (IP) that could apply throughout the grain processing system. IP is the creation of a transparent communication system that encompasses HACCP, traceability and related systems in the supply chain. This process guarantees that certain characteristics of the lots of food (non-GM origin) are maintained "from farm to fork". This article examines the steps taken by the Hellenic Food Safety Authority to examine the presence of GMOs in foods. The whole integrated European legislation framework currently in place still needs to be implemented in Greece. Penalties should be enforced to those who import, process GMOs without special licence and do not label those products. Similar penalties should be enforced to those companies that issue false certificates beyond the liabilities taken by the food enterprises for farmers' compensation. We argue that Greece has no serious reasons to choose the use of GMOs due to the fact that the structural and pedologic characteristics of the Greek agriculture favour the biological and integrated cultivation more. Greece is not in favour of the politics behind coexistence of conventional and GM plants and objects to the use of GMOs in the food and the environment because the processor has a big burden in terms of money, time and will suffer a great deal in order to prove that their products are GMO free or that any contamination is adventitious or technically unavoidable. Moreover, Greece owns a large variety of genetic material that should try to protect from patenting and commercialisation. Finally, we should be aware of the requirements of movement of GMOs within borders, i.e. GMOs grown or used in other countries but which are not intended to cross into Greece, since Greece is very close to countries that are non-EU. This is where the development of a new, integrated, trustworthy and transparent food quality control system will help to satisfy the societal demands for safe and quality products. On the other hand, Greece should not be isolated from any recent scientific technological development and should assess the possible advantages for some cultivation using a case by case approach. Finally, the safety assessment of GM foods and feed has been discussed according to the risk assessment methodology applied by EFSA.

Identification of a new endogenous platelet-activating factor-like molecule in gingival crevicular fluid

Periodontal disease is an inflammatory disease and the major cause of tooth loss in adults. Bacteria and their products are the causative agents of this disease. Endogenous molecules mediate the inflammatory process and play a major role in its amplification and perpetuation as well as in the ensuing tissue destruction. The relationship between platelet-activating factor (PAF) and periodontal disease has not so far been examined thoroughly. We have isolated a phospholipid molecule with PAF-like activity from gingival crevicular fluid. This molecule, purified on HPLC, causes washed platelet aggregation with EC50 value 0.1 microM, based on phosphorus determination. It acts through PAF-receptors and is inactivated by PAF-acetylhydrolase. In addition, this phospholipid presents biological activity towards human platelets. The combination of the results obtained from the chemical and enzymic treatments, the biological assays as well as results from the electrospray analysis, leads to the conclusion that this phospholipid is a hydroxyl-PAF analogue with relative molecular mass 703. This PAF-like molecule may be implicated in periodontal disease.

Synthesis of a new phosphoglycolipid with biological activity towards platelets

Various synthetic as well as naturally occurring compounds have been found to exhibit platelet-activating factor (PAF)-like activity or to act as specific PAF inhibitors. In this work we have synthesized a new phosphoglycolipid, methyl 2,3,4-tri-O-acetyl-6-(1'-O-stearoyl-2'-O- acetyl-DL-glycero-3'-phosphoryl)-alpha-D-glucopyranoside ammonium salt, using a combination of known synthetic steps. This phosphoglycolipid was first purified on TLC (Rf 0.7, using chloroform/methanol/water, 65:25:4, v/v/v as solvent system). It was further purified onto a high performance liquid chromatography silica column with an elution system that contained acetonitrile and methanol (retention time 13.5 min). Its identification was based on chemical determinations and electrospray mass spectrometry analysis. The above compound induced washed platelet aggregation with an EC50 value at 2 x 10(-4) M. The aggregation curve was biphasic, the first wave of which was through the PAF way while the second one was through the ADP way. Treatment with acetylhydrolase resulted in a rapid decrease of the first wave of aggregation and in a slow decrease of the second wave. In lower concentrations, the phosphoglycolipid inhibited PAF- and thrombin-induced aggregation with IC50 values of the order of 10(-7) M. In conclusion, this phosphoglycolipid has a diverse biological activity. The PAF-like activity of this new lipid enforces the conception that PAF is a member of a large family consisting of lipid mediators.