ABSTRACT
The cellular response to DNA damage is emerging as a promising target for cancer therapy. In the present study, the authors exploited the relationship between the level of the phosphorylated form of histone H2AX (γH2AX) and the extent of DNA damage and developed a quantitative, cell-based, high-content screening system for measuring the DNA damage response (DDR). In this system, the authors quantified the level of γH2AX by measuring DNA damage-induced γH2AX nuclear foci using an automated cell imager. They found that the total area of γH2AX foci per cell exhibited a good correlation with the concentration of DNA damage-inducing agents, including etoposide. The effects of 2 well-known inhibitors of DNA damage could be quantified using this system, suggesting the suitability of the γH2AX-foci quantification method for large-scale screening applications. This was confirmed by using this method to screen a chemical library; the resulting "hits" included compounds that inhibited early signaling events in DDR, as well those that inhibited subsequent DNA damage repair processes. Overall, this γH2AX foci-measuring system may be an effective screening method for identifying DNA damage response inhibitors that could eventually be used to develop novel anticancer drugs.
Subject(s)
Antineoplastic Agents/pharmacology , DNA Damage/drug effects , High-Throughput Screening Assays , Histones/metabolism , Biomarkers, Tumor , Cell Line, Tumor , Cell Nucleus/drug effects , Cell Nucleus/metabolism , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Humans , Microscopy, Fluorescence , Phosphorylation/drug effects , Reproducibility of Results , Sensitivity and Specificity , Signal Transduction/drug effects , Small Molecule LibrariesABSTRACT
BACKGROUND: The selective unilateral administration of drugs into a single lung of a rat is difficult because of the small airway diameter. Therefore, a simple method for unilateral administration into rat lung is needed. METHODS: Rats were assigned to 1 of 2 groups according to the direction of the catheter used for drug administration. Anesthetized rats were intubated, and curved epidural catheters were rotated up to a maximum of 90 degrees toward the left lung (group L) or right lung (group R). Bronchial catheters were then inserted via a tracheal tube and fixed. Methylene blue (0.3 ml) was injected via the epidural catheter. Additionally, to compare survival rates, rats were assigned to one of two groups according to the drug administration route. In group T, bleomycin hydrochloride (20 mg/kg) in 0.3 ml of phosphate-buffered saline (PBS) was administrated into the lung intratracheally via a tracheal tube. In group B, the same dose of bleomycin was administrated into the lung intrabronchially via a bronchial catheter, targeting the left lung. RESULTS: Gross examination revealed that targeted administration was 100% successful. Methylene blue was observed in the right lung of all rats in the R group and in the left lung of all rats in the L group. The survival rate was higher in group B than in group T. CONCLUSIONS: The intrabronchial method offers an advantage over tracheal administration as it decreases mortality and allows the administration of a drug unilaterally into a single lung or into a localized area without the need for double-lumen tubes or more invasive procedures.
ABSTRACT
Thoracic outlet syndrome has neurologic symptoms caused by compression of brachial plexus, blood vessel symptoms are caused by compression of the artery or vein. The authors report a case of sudden decrease in blood pressure of the left arm after turning the patient from supine position to prone position. They confirmed that the patient had thoracic outlet syndrome after performing computed tomography.
