Cytokine Expression on Microglial Proliferation and Apoptosis in Rat Lumbar Spinal Cord Following Unilateral Sciatic Nerve Transection

This study was carried out to elucidate the cytokine mRNAs expression and morphological features according to a microglial proliferation and apoptosis in a rat lumbar spinal cord, after a right sciatic nerve transection. The control group was composed of 5 rats (Spraque-Dawley) and the experimental group was composed of 70 rats. On post operation day (pod) 1, 2, 3, 5, and 7 eight rats were sacrificed on those days. On pod 10 five rats were sacrificed as well as five rats sacrificed on post operation weeks 2, 3, 4, 5, and 6. On light microscopy, activated microglia were often found in a perineuronal position around motoneurons in the ventral gray matter and more randomly distributed throughout the neuropil in the dorsal gray matter of lumbar spinal cord. GSA I-B4-positive microglia began to increase from 1 day after transection, and reached peak at 2~3 days and it persisted at 5~7 days and decreased thereafter. TUNEL-positive microglia was not observed in control group and began to increase from 5 days after transection and increased gradually until 3 weeks and decreased thereafter. On in situ RT-PCR, the positive signal for IL-1alpha and IL-6 mRNA was found mainly in the cytoplasm of the activated microglia and astrocytes at 1 day after transection and showed stronger signal at 3 days and decreased gradually until 10 days. TNF-alpha mRNA was detected 1 day after transection and remained for 7 days and localized to activated microglia as well as probably some astrocytes. The signal intensity of IL-1alpha and IL-6 mRNA was generally stronger than TNF-alpha mRNA. On transmission electron microscopy, there were chromatin condensation with margination toward nuclear membrane and condensation of cytoplasm at 3 days after transection. Apoptotic bodies were found after 5 days and increased gradually until 3 weeks. According to the above findings, it is concluded that apoptosis appears to be one mechanism by which activated microglia are gradually eliminated and cytokine expression seems to played an active role in the microglial turnover.

The Change of Clinical Characteristics of Prostatic Cancer before and after the Introduction of Prostate Specific Antigen Assay / 대한비뇨기과학회지

OBJECTIVE: To evaluate the change of clinical characteristics of prostatic cancer after the introduction of PSA (Prostate specific antigen) assay and TRUS (Transrectal ultrasonography), we retrospectively reviewed the medical records of 155 patients with prostatic adenocarcinoma who were managed at Seoul National University Hospital from January 1985 to December 1994. MATERIALS AND METHODS: Patients were stratified into 2 groups (Group I: 45pts{1985-1989} and Group II: 110pts{1990-1994}) by the year 1990 when our hospital began to use PSA assay and TRUS to detect prostatic cancer. PSA was measured by monoclonal radioimmunometric assay (ELSA-PSA). Tumor staging consisted of DRE (digital rectal. examination), TRUS, CT, MRI, simple bone X-ray and radionuclide bone scan. Clinical characteristics of 2 groups were compared. RESULT: Proportion of younger pts increased in group II but this was not statistically significant (p>0.05 by chi-square test). Number of pts were annually increasing , especially after the year 1990 when PSA assay and TRUS were introduced into clinical practice. Despite use of PSA and TRUS, the number of clinically localized pts did not differ between 2 groups. There was no difference in distribution of chief complaints between 2 groups. There were 3 pts who were detected by increased PSA alone. CONCLUSION: Prostate cancer incidence is increasing and will substantially increase in the future on the basis of increasing tendency to the old population, improved cancer detection and improved public awareness. More than 70% of pts have metastases or regional extension (Stage C or D). These dismal statistics constitute the main reason for early detection programs in the population at large.