Nitrative stress in refractory asthma.

Background: Most asthma is mild and moderate and can be well controlled by low-dose inhaled steroid with or without bronchodilators. However, 5% to 10% of patients with asthma have more troublesome disease despite using such medication. Recent reports showed that nitrative stress induced tissue remodeling in vitro, which is associated with a component of refractoriness in asthma.

Efavirenz-induced neurological symptoms in rare homozygote CYP2B6 *2/*2 (C64T).

Some of the HIV-1-infected patients who were given highly active anti-retroviral therapy (HAART) including efavirenz (EFV) presented adverse central nervous system (CNS) symptoms such as fatigue and insomnia. The incidence of adverse CNS symptoms is associated with hepatic cytochrome P450 isozymes (CYP2B6) polymorphisms. For example, CYP2B6 *6 (G516T and A785G) and *7 (G516T, A785G and C1459T) prolonged the EFV half-life despite discontinuation of EFV.

Decreased expression of antioxidant enzymes and increased expression of chemokines in COPD lung.

The involvement of inflammation in the pathogenesis of chronic obstructive pulmonary disease (COPD) has been investigated using samples from relatively central airways such as airway biopsies, but there have been fewer studies in the peripheral lung, which is thought to be the main site of the disease process. To determine the molecules that relate to the mechanisms underlying the pathogenesis of COPD, we evaluated the mRNA expression of inflammatory cytokines, chemokines, oxidant enzymes, antioxidant enzymes, proteinases and antiproteinases in peripheral lung tissues from 33 COPD and non-COPD subjects who were undergoing lung resection for lung cancer using an RT-PCR technique. Among the 42 studied candidate genes, the expressions of mRNA for catalase, glutathion S-transferase P1 (GSTP1), glutathion S-transferase M1 (GSTM1), microsomal epoxide hydrolase (mEPHX) and tissue inhibitor of metalloproteinase 2 (TIMP2) were significantly decreased in COPD lung tissues compared with those in non-COPD tissues, and most of these decreases were significantly correlated with the degree of airflow limitation.

Cytokine-mediated xanthine oxidase upregulation in chronic obstructive pulmonary disease's airways.

Reactive oxygen species have been reported to be involved in the airway inflammatory process of chronic obstructive pulmonary disease (COPD). The aim of this study was to quantify the activity of xanthine oxidase (XO), which generates a potent radical superoxide anion in COPD airways. Thirteen stable COPD patients and 10 healthy subjects participated in this study.

Quantitative assessment of protein-bound tyrosine nitration in airway secretions from patients with inflammatory airway disease.

Because reactive nitrogen species (RNS) have potent inflammatory activity, they may be involved in the inflammatory process in pulmonary diseases. We recently reported increased numbers of 3-nitrotyrosine immunopositive cells, which are evidences of RNS production, in the sputum of patients with chronic obstructive pulmonary disease (COPD) and patients with asthma compared with healthy subjects. In the present study, we attempted to quantify this protein nitration in the airways by means of high-performance liquid chromatography (HPLC) used together with an electrochemical detection system that we developed.