Derviş Mansuri Yılmaz

Effect of neutralization of rat interleukin 6 bioactivity on inducible nitric oxide synthase up-regulation and cerebral ischemic damage

Abstract Objectives: Our aim was to investigate whether neutralization of rat interleukin 6 (IL-6) bioactivity attenuates inducible nitric oxide synthase (iNOS) up-regulation and ameliorates cerebral ischemic damage in a model of focal central nervous system (CNS) ischemia. Methods: Seventy rats were randomly allocated to groups: Group I (n=10) consisted of normal controls; Group II (n=20) underwent surgical exposure of the middle cerebral artery but no cauterization; the remaining 40 rats were subjected to middle cerebral artery occlusion. Immediately after occlusion, each of these 40 rats was randomly assigned to either the occlusion-only group (Group III, n=20) or the occlusion plus IL-6 antibody treatment group (Group IV, n=20). Half of the rats from each of Groups II, III and IV were eternized at 24 hours and the other half at 72 hours. The samples were used for iNOS immunohistochemistry and structural analysis. Results: A single dose of the antibody had no effect on structural changes and iNOS at 24 hours after occlusion. However, administering three doses of the antibody resulted in markedly decreased quantitative and qualitative levels of iNOS-positive stained cells and milder subcellular damage compared with the findings in the occlusion-only group at 72 hours after occlusion. Discussion: Our findings prove that IL-6 bioactivity is one of the pathological events that trigger the induction of iNOS in the process of CNS ischemic injury. It appears that there may be therapeutic value in neutralization of IL-6 bioactivity to attenuate iNOS up-regulation and ameliorate cerebral ischemic damage in long-term recovery.

Effects of arginine vasopressin and v1 receptor antagonist on cerebral vasospasm secondary to subarachnoid hemorrhage: an experimental study

AIM To examine morphological, radiological and biochemical effects of arginine vasopressin (AV) and V1 receptor antagonist on cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH) in rabbits. MATERIAL AND METHODS Forty male New Zealand white rabbits were randomly divided into four groups comprising 10 rabbits each. The groups were; 1) Control group, 2) SAH group, 3) SAH+AV group, 4) SAH+V1 antagonist group. Diameters of the basilar artery in all groups were measured on angiograms. All animals were sacrificed two days following basilar angiography and tissue samples of basilar artery were obtained under microscope immediate after craniectomy for ultrastructural and biochemical examinations. RESULTS The artery diameters were found to be 50% and 50% at the 30th minute in the groups 2 and 3 respectively. In group 3, CVS was 13% more in comparison with the 2nd group. In group 4, vascular constriction was 34.5% at the 30th minute and about 30.9% at the 300th minute. Despite the increase in regional blood flow, AV did not provide morphological change. Histological appearance was related to vascular stenosis due to CVS. Histological outcome was the best in group 4 because of less CVS. CONCLUSION Arginine vasopressin plays an important role in CVS. We detected morphological and radiological recovery in basilar artery, besides moderate improvement due to AV receptor antagonist in CVS.

Serebral Anevrizma Cerrahi Komplikasyonları

Serebral anevrizmalarin kraniotomi ile klipaji yillardir kullanilagelen en onemli cerrahi tedavi seklidir. Cerrahi ekipmanlar ve intraoperatif monitorizasyon tekniklerindeki gelismeler bu cerrahiyi daha da guvenilir bir hale getirmistir. Anevrizmayi tamamen kapamaya yonelik cerrahi yeniden kanama riskini anlamli oranda azaltsa da, intraoperatif ve postoperatif komplikasyonlar hala cerrahi tedavinin faydalarini kisitlayan onemli faktorlerdir. Beyin cerrahi ekibi hastayi yakindan takip etmelidir. Hastalarin buyuk cogunlugunda en az bir norolojik veya cerrahi komplikasyon gelismektedir, bu nedenle tedavi sonuclarinin iyilestirilebilmesi bu komplikasyonlarin erkenden teshis ve tedavisi icin surekli tetikte olmayi gerektirmektedir.