Analysis of the molecular and behavioral effects of acute social isolation on rats.

The mechanism underlying depression, anxiety, and stress-related psychiatric disorders is far from understood. The utilization of animal models of anxiety and stress can improve our knowledge of the pathology of these disorders as well as aiding in the identification of pharmacological therapeutic targets. The involvement of inflammation in the pathology of stress-related disorders is widely acknowledged. This study was therefore undertaken to assess depressive and anxiety-like behavior as well as neuroinflammation in acute-isolated rats. The study design comprised two main groups:1) rats in acute isolation (one rat per cage) and 2) standard housing (two rats per cage). Within ten days of acute isolation, we carried behavioral tests including Sucrose Neophobia (SNP), Sucrose Preference Test (SPT), Open field (OPF), and a Forced swim test (FST). In a separate set of experiments, we examined the molecular changes after five days of isolations, we examined the mRNA expression of Toll-like receptors (TLRs) and inflammatory markers in the hippocampal brain region. We found that acute social isolation did not have profound functional effects and the behavioral analysis revealed similarities between the isolated and standard housed rats. However, the molecular studies showed a significant increase in TLRs. An increase in Interleukin 6 (IL-6) and Tumor necrosis factor-alpha (TNF-alpha) was observed in the hippocampus of isolated rats but not the control rats. The results suggest that acute environmental isolation does not significantly affect depressive and anxiety-like behavior but does contribute to upregulations in neuroinflammatory responses. This indicates the initiation of neuronal insults following exposure to short-term isolation.

QIAGEN Therascreen KRAS RGQ Assay, QIAGEN KRAS Pyro Assay, and Dideoxy Sequencing for Clinical Laboratory Analysis of KRAS Mutations in Tumor Specimens.

OBJECTIVE: To compare the performance of assays used to assess KRAS mutations in tumor specimens. METHODS: We analyzed DNA extracted from 30 formalin-fixed paraffin-embedded (FFPE) tumor specimens using the QIAGEN Therascreen KRAS RGQ and QIAGEN Pyro reagents, with dideoxy sequencing (colloquially considered to be the gold standard) as the reference method. RESULTS: We detected 22 codon 12 or 13 KRAS mutations using the Pyro assay, whereas the RGQ assay detected 19 mutations. For mutation detection, the clinical sensitivity was 86% for the RGQ assay compared with 100% for the Pyro but 100% for the KRAS mutations that the RGQ was predesigned to detect. The Pyro could detect rare mutations. The RGQ demonstrated a lower limit of detection compared with the Pyro; However, the Pyro required less DNA input than the RGQ. CONCLUSION: The 2 assays that we tested yielded comparable performance in detecting KRAS mutations, as we had expected based on assay design. Overall, the Pyro assay detects more mutations and requires less DNA input but is less analytically sensitive, compared with the RGQ assay.