Identification of a Crohn's disease specific transcript with potential as a diagnostic marker

Cloning and identification of differentially expressed transcripts in primary culture of GABAergic neurons

A RNA based arbitrarily primed polymerase chain reaction (RAP-PCR) was used to identify differentially expressed transcripts in primary cultures of cerebral cortical neurons prepared from E16 mouse cerebral cortex. The majority of neurons found in this culture preparation are known to be GABAergic. Different primer combinations were used, and the PCR products were separated on PAGE. Visualization by silver staining revealed a high resolution RNA fingerprint pattern with a total of about 200 transcripts. Six differentially expressed cDNA fragments were recovered, cloned and sequenced. The results of a NCBI database search showed that 6 clones were highly homologous to known genes and expressed sequence tags (ESTs), and that they were either up-regulated or down-regulated during development. Among these clones, Clone 3.1.7 shared 99% sequence homology to mouse Reelin, a neuronal migration and positioning related protein. Clone 4.6.2 shared 91% homology to Rat prepro bone morphogenetic protein-3 mRNA. Clone 6.10.2 had 90% homology to a novel orphan gene of calcium-independent alpha-latrotoxin receptor, which stimulates presynaptic neurotransmitter release. Northern blot analysis confirmed the up-regulated expression profile of Clone 6.10.2 in neuron from Day 2 to 7 during stages of differentiation and development.

Diagnostic markers of inflammatory bowel disease

The diagnosis of inflammatory bowel disease is usually straightforward, based on a detailed history and physical examination, along with standard radiographic and endoscopic investigations, biopsies, and laboratory parameters. More challenging is the search for clinically useful, noninvasive markers for Crohn disease and ulcerative colitis to accurately screen cases with nonspecific and indolent symptoms. Equally required are diagnostic markers that discriminate between these two disorders in cases with indeterminate colitis. Another dilemma for clinicians is that there are no simple measures to observe disease activity and predict relapses. This review describes the recent advances in diagnostic markers that afford the ability to screen for inflammatory bowel disease, discriminate between its types, and monitor disease activity. These include serological, fecal, and tissue markers; permeability tests; and diagnostic imaging using color Doppler ultrasonography.