Primer: genomic and proteomic tools for the molecular dissection of disease

Host biomarkers and paediatric infectious diseases: from molecular profiles to clinical application

Infectious diseases are an important cause of death among children under the age of 5 (Stein et al., 2004). Most of these deaths are caused by preventable or curable infections. Limited access to medical care, antibiotics, and vaccinations remains a major problem in developing countries. But infectious diseases also continue to be an important public health issue in developed countries. With the help of modern technologies, some infections have been effectively controlled; however, new diseases such as SARS and West Nile virus infections are constantly emerging. In addition, other diseases such as malaria, tuberculosis, and bacterial pneumonia are increasingly resistant to antimicrobial treatment.

Patched-one or smoothened gene mutations are infrequent in chondrosarcoma

Constitutive hedgehog signaling has been implicated in the tumorigenesis of cartilaginous neoplasia; however, a common mutational mechanism remains unknown. Some tumors exhibiting hedgehog pathway activation such as basal cell cancer frequently harbor PATCHED-ONE (PTCH-1) or SMOOTHENED (SMO) gene mutations. We therefore asked whether mutations of the hedgehog receptor genes PTCH-1 or SMO occur in cartilage tumors. Singlestrand conformation polymorphism (SSCP) analysis with subsequent manual sequencing was performed to detect alterations of PTCH-1 and SMO in 46 cartilage tumors. SSCP detected five shifts in the PTCH-1 gene and two shifts in SMO. Direct DNA sequencing revealed the five shifts in PTCH-1 were caused by silent nucleotide alterations. The two SMO shifts were the result of the same missense mutation (783G>A) and occurred in one dedifferentiated chondrosarcoma and a synovial chondromatosis. The patient with chondromatosis also carried this same mutation in the germline. However, this mutation was also identified in leukocyte DNA from three of 127 (2.4%) control subjects without cartilage tumors, suggesting it may represent a rare SMO variant. Constitutive activation of the hedgehog signaling pathway in chondrosarcoma is rarely caused by PTCH-1 or SMO mutations. [corrected]

Immunoaffinity capillary electrophoresis as a powerful strategy for the quantification of low-abundance biomarkers, drugs, and metabolites in biological matrices

In the last few years, there has been a greater appreciation by the scientific community of how separation science has contributed to the advancement of biomedical research. Despite past contributions in facilitating several biomedical breakthroughs, separation sciences still urgently need the development of improved methods for the separation and detection of biological and chemical substances. In particular, the challenging task of quantifying small molecules and biomolecules, found in low abundance in complex matrices (e.g., serum), is a particular area in need of new high-efficiency techniques. The tandem or on-line coupling of highly selective antibody capture agents with the high-resolving power of CE is being recognized as a powerful analytical tool for the enrichment and quantification of ultra-low abundance analytes in complex matrices. This development will have a significant impact on the identification and characterization of many putative biomarkers and on biomedical research in general. Immunoaffinity CE (IACE) technology is rapidly emerging as the most promising method for the analysis of low-abundance biomarkers; its power comes from a three-step procedure: (i) bioselective adsorption and (ii) subsequent recovery of compounds from an immobilized affinity ligand followed by (iii) separation of the enriched compounds. This technology is highly suited to automation and can be engineered to as a multiplex instrument capable of routinely performing hundreds of assays per day. Furthermore, a significant enhancement in sensitivity can be achieved for the purified and enriched affinity targeted analytes. Thus, a compound that exists in a complex biological matrix at a concentration far below its LOD is easily brought to well within its range of quantification. The present review summarizes several applications of IACE, as well as a chronological description of the improvements made in the fabrication of the analyte concentrator-microreactor device leading to the development of a multidimensional biomarker analyzer.