• Gene expression differences in infected and noninfected middle ear complementary DNA libraries.

Gene expression differences in infected and noninfected middle ear complementary DNA libraries.

Archives of otolaryngology--head & neck surgery (2009-01-21)
Joseph E Kerschner, Edward Horsey, Azad Ahmed, Christy Erbe, Pawjai Khampang, Joseph Cioffi, Fen Ze Hu, James Christopher Post, Garth D Ehrlich

To investigate genetic differences in middle ear mucosa (MEM) with nontypeable Haemophilus influenzae (NTHi) infection. Genetic upregulation and downregulation occurs in MEM during otitis media (OM) pathogenesis. A comprehensive assessment of these genetic differences using the techniques of complementary DNA (cDNA) library creation has not been performed. The cDNA libraries were constructed from NTHi-infected and noninfected chinchilla MEM. Random clones were picked, sequenced bidirectionally, and submitted to the National Center for Biotechnology Information (NCBI) Expressed Sequence Tags database, where they were assigned accession numbers. These numbers were used with the basic local alignment search tool (BLAST) to align clones against the nonredundant nucleotide database at NCBI. Analysis with the Web-based statistical program FatiGO identified several biological processes with significant differences in numbers of represented genes. Processes involved in immune, stress, and wound responses were more prevalent in the NTHi-infected library. S100 calcium-binding protein A9 (S100A9); secretory leukoprotease inhibitor (SLPI); beta(2)-microglobulin (B2M); ferritin, heavy-chain polypeptide 1 (FTH1); and S100 calcium-binding protein A8 (S100A8) were expressed at significantly higher levels in the NTHi-infected library. Calcium-binding proteins S100A9 and S100A8 serve as markers for inflammation and have antibacterial effects. Secretory leukoprotease inhibitor is an antibacterial protein that inhibits stimuli-induced MUC1, MUC2, and MUC5AC production. A number of genes demonstrate changes during the pathogenesis of OM, including SLPI, which has an impact on mucin gene expression; this expression is known to be an important regulator in OM. The techniques described herein provide a framework for future investigations to more thoroughly understand molecular changes in the middle ear, which will likely be important in developing new therapeutic and intervention strategies.

Product Number
Product Description

Thiamine hydrochloride, tested according to Ph. Eur.
Thiamine hydrochloride, meets USP testing specifications
Thiamine hydrochloride, BioReagent, suitable for cell culture, suitable for insect cell culture, suitable for plant cell culture
Thiamine hydrochloride, reagent grade, ≥99% (HPLC)
Thiamine hydrochloride, ≥98%, FCC, FG
Thiamine hydrochloride, Pharmaceutical Secondary Standard; Certified Reference Material