Imprint cytology of osteosarcoma of the jaw: a case report

Introduction. Osteosarcomas are highly malignant bone-forming neoplasms that account for about 20% of all sarcomas. In light of their aggressive behavior, early diagnosis is crucial for determining adequate treatment. Dental professionals may be the first to detect jaw osteosarcomas in their initial stages. The aim of this case report is to draw attention to the possibility of diagnosing this tumor based on clinical, radiographical and cytological characteristics before confirmation by histology. Case presentation. A 24-year-old Afro-Brazilian man presented with swelling and pain on the left side of the mandible in the region of the third molar (tooth 38). Radiography showed a poorly delimited intraosseous lesion with radiolucent and radiopaque areas. The cytological aspects were consistent with the diagnosis of osteosarcoma, which was confirmed by biopsy. Conclusion. Imprint cytology was found to be a reliable, rapid and easy complementary examination. An early diagnosis of osteosarcoma of the jaw is fundamental to the early determination of an adequate treatment. © 2009 Cabral et al; licensee BioMed Central Ltd

Nuclear magnetic resonance spectroscopy for structural characterization of bioactive compounds

The structural assignment of a new natural product molecule is not only to establish the 3D structure of a compound, but potentially to provide the basis for research in a multitude of disciplines, ultimately generating new therapeutic agents and/or new understanding of disease biology. The development of modern spectroscopic techniques has transformed the structure assignment process, which previously was essentially based on chemical degradation or derivatization followed by partial or total synthesis. Notably, it was only in the specialization era of the spectroscopic structural assignment of natural products that the field of marine natural products chemistry took shape. Today the processes of marine and terrestrial natural product isolation and structural determination are frequently streamlined and expeditious due to the spectacular advances in chromatographic and spectroscopic technologies as well as chemical synthesis. The NMR spectroscopy is a powerful tool in structure elucidation because the properties it displays can be related to the molecular structure. The chemical environment of a particular nucleus is associated with the chemical shift (d, ppm), and the area of a resonance, usually presented as its relative integral, is related to the number of nuclei giving rise to the NMR signal. The interactions between individual nuclei, mediated by electrons in a chemical bond, determine the coupling constant (J, Hz). In this chapter we will present the techniques commonly used, basic concepts, and how they are useful for chemists in the structural elucidation of mainly bioactive marine natural products. Its complex planar structure is determined by 1H and 13C NMR analysis strongly supported by other 1D (DEPT) and 2D (COSY, TOCSY, HSQC/HMQC, HMBC) NMR techniques. The stereochemistry is generally based on NOE experiments (NOE difference, NOESY, and ROESY), 1H–1H and 1H–13C coupling constants, chiral derivatizing agents, and also in empirical procedures comparing the chemical shifts of unknown vicinal and proximal centers with libraries of configurationally known stereomodels. However, the most reliable option to assign all the 3D structure of a marine natural product still is their total synthesis. The use of NMR hyphenated with other chromatographic and spectroscopic techniques and microcoil probes and narrow diameter tube probes for the structural elucidation of bioactive marine natural products, mainly associated with the quantitative NMR determinations, will be also briefly described. The chapter will finish with a description of the structural characterization of several types of marine natural products using all the referred NMR techniques followed by a small reference to the misassignments that still are very common

iOD907, the first genome-scale metabolic model for the milk yeast Kluyveromyces lactis

We describe here the first genome-scale metabolic model of Kluyveromyces lactis, iOD907. It is partially compartmentalized (4 compartments), composed of 1867 reactions and 1476 metabolites. The iOD907 model performed well when assessing the positive growth of K. lactis to Biolog experiments and to an online catalogue of strains that provides information on carbon sources in which K. lactis is able to grow. Chemostat experiments were used to adjust non-growth-associated energy requirements, and the model proved accurate when predicting the biomass, oxygen and carbon dioxide yields. In silico knockouts predicted in vivo phenotypes accurately when compared to published experiments. The iOD907 genome-scale metabolic model complies with the MIRIAM standards for the annotation of enzymes, transporters, metabolites and reactions. Moreover, it contains direct links to KEGG (for enzymes, metabolites and reactions) and to TCDB for transporters, allowing easy comparisons to other models. Furthermore, this model is provided in the well-established SBML format, which means that it can be used in most metabolic engineering platforms, such as OptFlux or Cobra. The model is able to predict the behavior of K. lactis under different environmental conditions and genetic perturbations. Furthermore, it can also be important in the design of minimal media and will allow insights on the milk yeast's metabolism, as well as identifying metabolic engineering targets for the improvement of the production of products of interest by performing simulations and optimizations.The authors thank strategic Project PEst-OE/EQB/LA0023/2013 and project "BioInd - Biotechnology and Bioengineering for improved Industrial and Agro-Food processes, REF. NORTE-07-0124-FEDER-000028" co-funded by the Programa Operacional Regional do Norte (ON.2 - O Novo Norte), QREN, FEDER. The authors would also like to acknowledge Steve Sheridan for proof reading this manuscript