Optimal cultivation of Chlamydia requires testing of serum on individual species.

Objective: This report is a side product of experiments aimed at identifying serum for culturing obligate intracellular bacteria Chlamydia trachomatis and C. muridarum in mouse fibroblast L929 cells.

Results: Of five commercial serum samples tested, two showed optimal efficiencies at supporting growth of the human pathogen Chlamydia trachomatis as control fetal bovine serum, whereas two showed modest ~ 40% inhibitions in progeny production, and the remaining one showed a 20% inhibition.

Application of Biolayer Interferometry (BLI) for Studying Protein-Protein Interactions in Transcription.

A transcription factor (TF) is a protein that regulates gene expression by interacting with the RNA polymerase, another TF, and/or template DNA. GrgA is a novel transcription activator found specifically in the obligate intracellular bacterial pathogen Chlamydia. Protein pulldown assays using affinity beads have revealed that GrgA binds two σ factors, namely σ and σ, which recognize different sets of promoters for genes whose products are differentially required at developmental stages.

Role for GrgA in Regulation of σ-Dependent Transcription in the Obligate Intracellular Bacterial Pathogen Chlamydia trachomatis.

The obligate intracellular bacterial pathogen has a unique developmental cycle consisting of two contrasting cellular forms. Whereas the primary sigma factor, σ, is involved in the expression of the majority of chlamydial genes throughout the developmental cycle, expression of several late genes requires the alternative sigma factor, σ In prior work, we identified GrgA as a specific transcription factor that activates σ-dependent transcription by binding DNA and interacting with a nonconserved region (NCR) of σ Here, we extend these findings by showing GrgA can also activate σ-dependent transcription through direct interaction with σ We measure the binding affinity of GrgA for both σ and σ, and we identify regions of GrgA important for σ-dependent transcription. Similar to results obtained with σ, we find that GrgA's interaction with σ involves an NCR located upstream of conserved region 2 of σ Our findings suggest that GrgA is an important regulator of both σ- and σ-dependent transcription in and further highlight NCRs of bacterial RNA polymerase as targets for regulatory factors unique to particular organisms.

Engineering goals for future thoracic endografts-how can we make them more effective?

Endovascular treatments for catastrophic aortic conditions have gained increasing popularity over the past 20 years. Originally developed for abdominal aortic aneurysms (EVAR), treatment has been modified for use in thoracic aortic repair (TEVAR). As expanding numbers of patients with increasingly intractable conditions and more hostile anatomies are treated, endovascular stent designs are maturing to be suitable for these more demanding situations.

4-methylpyrazole decreases 1,4-butanediol toxicity by blocking its in vivo biotransformation to gamma-hydroxybutyric acid.

1,4-Butanediol (1,4-BD), a prodrug converted in vivo to gamma-hydroxybutyric acid by alcohol dehydrogenase, has resulted in life-threatening overdoses and deaths. We investigated whether 4-methylpyrazole (4-MP), an alcohol dehydrogenase antagonist, can be used as an antidote in a murine model of 1,4-BD overdose. CD-1 mice were overdosed with 1,4-BD, 600 mg/kg i.

Enzyme and receptor antagonists for preventing toxicity from the gamma-hydroxybutyric acid precursor 1,4-butanediol in CD-1 mice.

1,4-Butanediol (1,4-BD), the diol alcohol precursor of gamma-hydroxybutyric acid (GHB), undergoes in vivo enzymatic biotransformation to GHB by alcohol dehydrogenase (ADH) and aldehyde dehydrogenase. The subsequent metabolite, GHB, is pharmacologically active at GABA(B) and GHB receptors. GHB can be metabolized in vivo to gamma-aminobutyric acid (GABA) and trans-4-hydroxycrotonic acid (T-HCA), which are also pharmacologically active at GABA(B) receptors and GHB receptors, respectively.