Such misrepairs make the muscular tissue weak in functioning, and the fluid secreted by glands cannot be excreted completely. Then, the accumulation of fluid in glands increases the resistance of muscular tissue during the movements of contractions and dilations, and more and more myofibers will be broken and replaced by collagen fibers. Pathophysiology
As men age, the enzymes aromatase and 5-alpha reductase increase in activity. These enzymes are responsible for converting androgen hormones into estrogen and dihydrotestosterone, respectively. This metabolism of androgen hormones leads to a decrease in testosterone but increased levels of DHT and estrogen. Both the glandular epithelial cells and the stromal cells (including muscular fibers) undergo hyperplasia in BPH. Most sources agree that of the two tissues, stromal hyperplasia predominates, but the exact ratio of the two is unclear. :694Anatomically the median and lateral lobes are usually enlarged, due to their highly glandular composition. The anterior lobe has little in the way of glandular tissue and is seldom enlarged. (Carcinoma of the prostate typically occurs in the posterior lobe – hence the ability to discern an irregular outline per rectal examination). The earliest microscopic signs of BPH usually begin between the age of 30 and 50 years old in the PUG, which is posterior to the proximal urethra. :694 In BPH, the majority of growth occurs in the transition zone (TZ) of the prostate. :694 In addition to these two classic areas, the peripheral zone (PZ) is also involved to a lesser extent. :695 Prostatic cancer typically occurs in the PZ.
The mean terminal half-life was similar between pediatric and adult patients and ranged from 15.7 to 22.5 hours. The mean volume of distribution of rasburicase ranged from 110 to 127 mL/kg in pediatric patients and from 75.8 to 138 mL/kg in adult patients, respectively. Minimal accumulation of rasburicase ( < 1.3 fold) was observed between days 1 and 5 of dosing. In adults, age, gender, baseline liver enzymes and creatinine clearance did not impact the pharmacokinetics of rasburicase. A cross-study comparison revealed that after administration of rasburicase at 0.15 or 0.20 mg/kg, the geometric mean values of body-weight normalized clearance were approximately 40% lower in Japanese (n=20) than that in Caucasians (n=22). Society and culture
Economics
Rasburicase is much more expensive than the conventional uric acid lowering treatment for tophaceous gout. References
External links
"Rasburicase". Drug Information Portal. U.S. National Library of Medicine.