A BESS-T-Scan analysis of cDNA COL1A1 and COL1A2 obtained by RT-PCR derived from five patients with sporadic forms of ostegenesis imperfecta was performed. The study was done in four patients with type I and one patient with type III OI. The analysis revealed the presence of structural changes in two regions of cDNA COL1A1 in two patients. No quantitative changes referring to COL1A2 gene were noted in any patient. The above analysis was the first application of the BESS-T-Scan technique in a molecular diagnosis of OI. The applied method seems to be useful and fulfil the basic criteria of the screening method to detect and locate mutations.
Leukotrienes are lipid mediators produced via 5-lipooxygenase pathway of arachidonic acid. At least two cysteinyl-leukotrienes receptors are highly expressed in the heart, including the conduction system. Coronary angiography or angioplasty is accompanied by release of cysteinyl leukotrienes into coronary circulation and into urine. We tested the hypothesis that inhibition of leukotrienes biosynthesis would affect the conductance system function. In a double-blind placebo controlled study, patients with stable angina undergoing elective coronary catheterization or angioplasty were randomly assigned to 48 hrs treatment with a 5-lipoxgenase inhibitor (n=54) or placebo (n=49). ECG Holter recording was carried out for 24 hrs before and after the procedure and urinary leukotriene E4 measurements were done. Inhibition of 5-lipoxygenase caused 26% reduction of urinary leukotriene E4, associated with: 1) decrease in heart rate by about 7%, 2) enhanced heart rate variability; 3) protection against depressions in atrioventricular conductance and ventricular repolarization induced by the procedure. No effects on either arrhythmias, or ECG patterns of ischemia were noted. We conclude that pharmacological inhibition of 5-lipoxygenase, shortly before percutaneous coronary intervention, reveals specific actions of leukotrienes on the heart rhythm. Inhibitors of 5-lipoxygenase might be of interest as a novel class of cardiac drugs affecting the conductive system.