LOW O6-METHYLGUANINE-DNA METHYTRANSFERASE (MGMT) AND PAN-CYTOKERATIN (PAN-CK) EXPRESSION VIA IMMUNOHISTOCHEMISTRY IN PITUITARY ADENOMAS.

INTRODUCTION: Pituitary adenomas (PA) are the third most common intracranial tumors, with an incidence rate of 10-15%. More than half are invasive, infiltrating adjacent structures. The primary objective of this project was to determine whether MGMT expression is associated with the invasiveness of PA. MATERIAL AND METHOD: All patients who underwent surgical decompression consecutively between 2007-2012 were included. All data were obtained from the case records. Formalin-fixed paraffin-embedded (FFPE) tissue specimens were stained with hematoxylin and eosin (HE) and then examined via light microscope. Paraffin blocks that lacked necrosis and hemorrhage were chosen for histologic examination. In addition to an immunoprofile battery that consisted of Ki-67 and p53, MGMT, S-100 and Pan-CK were evaluated as well. RESULTS: The subjects included 25 women and 15 men. The mean age was 48.9 ± 14.5 years. Of these, 63% of cases involved the invasion of adjacent structures. Of the PA, 17 (42%) were non-functioning pituitary adenomas (NFPA). There was a statistically significant relationship between the invasiveness and Ki-67, p53, MGMT expression, and prolactinoma. Gonodotropinomas were mostly non-invasive. FPAs presented invasive features more frequently than NFPAs. Pan-CK was positive in GH-secreting adenomas but negative in FSH- and LH-secreting adenomas. CONCLUSION: Ki-67 and p53 in lower expression level can be used for evaluating invasiveness but not for recurrence. MGMT expression can be a useful IHC indicator for invasiveness. However, Pan-CK cannot be used for invasiveness or aggressiveness.

Clinical and radiological characteristics of tumefactive demyelinating lesions: follow-up study.

BACKGROUND: Demyelinating lesions over 20 mm in size, referred to as tumefactive demyelinating lesions, can be misdiagnosed as being either a tumor or an abscess. Although some radiological characteristics can help make a differential diagnosis easier, a cerebral biopsy may still be necessary. OBJECTIVE: Our objective was to assess the clinical characteristics of tumefactive lesions, with or without a diagnosis of multiple sclerosis (MS), and present follow-up data for 54 patients with tumefactive lesions. METHODS: Demographic, clinical, radiological and laboratory data were gathered and treatment responses were evaluated in a total of 54 patients from five medical centers. RESULT: Twenty-nine patients were diagnosed with tumefactive lesions at the onset, whereas 25 patients were diagnosed with tumefactive lesions after a diagnosis of MS. Median follow-up was 38.12 months. At final examination, 19 of the patients with a tumefactive lesion diagnosis at the onset eventually developed relapsing-remitting MS, while 10 remained with the condition as a clinically isolated syndrome. The tumefactive lesions studied were mostly focal, with closed-ring enhancement. We found that oligoclonal band positivity was less frequent in the patients with tumefactive onset. CONCLUSION: Although our demographic data were similar to formerly collected Turkish MS data, we found that the distribution of the patients' clinical course differed if there was an absence of primary progressive MS and that there was a lower frequency of secondary progressive MS cases in our group of patients. We believe that less frequent oligoclonal band positivity and the difference we witnessed in the clinical course of disease in our study groups suggest that there is a need for further studies to compare all the biological and immunological differences between MS and tumefactive lesion cases, in order to reveal whether there are different pathogenetic mechanisms involved.

Diagnostic approach to reveal retroperitoneal injury during lumbar discectomy.

For decades, lumbar discectomy has been one of the most common surgical practices performed by neurosurgeons. Although it has proved to be an effective and safe surgical procedure, life threatening complications may occur in rare cases, including iliac artery and/or vein injuries, superior rectal artery injury, common iliac artery aneurysms, iliac arteriovenous fistula, intestinal injuries, and ureteral injuries. Ureteral damage during the lumbar L4-5 microdiscectomy was reported in a slim 50 year-old male patient. Because of a small amount of bleeding occurred during the surgery as soon as the patient came out of anesthesia, an angio-computed tomography (CT) of the abdomen was performed. It showed no hematoma and no major vascular injury, but air bubbles were seen in the retroperitoneal region, indicating that perforation had occurred. The patient was then monitored carefully for immediate and possible subsequent injuries, in this way; ureteral damage was found and repaired. This is perhaps the first such case report in the literature of the early detection of ureteral damage using an angio CT scan. If there is a suspicion of perforation of the anterior annulus fibrosus and anterior longitudinal ligaments but no indication for an emergency laparotomy, an abdominal angio CT done immediately after the surgery and an abdominal non-contrast CT 4 hours later will give sufficient information concerning the potential occurrence of nearly all the major complications associated with lumbar discectomy.

Role of dopaminergic system in core part of nucleus accumbens in hyperlocomotion and rearing induced by MK-801 in rats: a behavioral and in vivo microdialysis study.

We investigated modification of the MK-801 effect on motor activity and extracellular amines concentration by 6-hydroxydopamine (6-OHDA)-induced lesion of core nucleus accumbens (cACC) of rats. In vivo microdialysis-HPLC showed that the concentrations (fmol/microl) of dopamine (DA), dihydroxyphenylacetic acid (DOPAC) and serotonin were 0.738 +/- 0.135, 155.34 +/- 41.01 and 0.334 +/- 0.024, respectively, in the cACC of intact rats. The DOPAC/DA ratio was 264.24 +/- 94.01. Unilateral lesion of the cACC with 6-OHDA (8 microg/microl) substantially reduced DA (-93%) and DOPAC (-97%) in desipramine (30 mg/kg, i.p.)-pretreated rats (6-OHDA+DMI rats) as compared to the 65% reduction rate of both amines in saline-pretreated rats (6-OHDA+saline rats). Moreover, DOPAC was reduced by 72% in 6-OHDA+DMI rats. MK-801 increased DOPAC (426-467%) and DOPAC/DA ratio (180-230%) in intact rats. On the other hand, MK-801 increased DA by 154% and 505% in 6-OHDA+saline and 6-OHDA+DMI rats, respectively. 6-OHDA reduced the effect of MK-801 on DOPAC and DOPAC/DA ratio. In the behavioral studies, MK-801 (0.01-0.3 mg/kg, i.p.) increased locomotor activity and rearing of intact rats. Bilateral 6-OHDA+DMI lesion of the cACC caused greater reduction in the effect of MK-801 (0.1 mg/kg) than that of the shell nucleus accumbens. These results suggest that increased extracellular DOPAC concentration (but not DA) and DOPAC/DA ratio in the cACC plays an important role in MK-801-hyperactivity.

Destruction of the noradrenergic system with DSP4 potentiates the behavioral effects of MK-801 in rats.

In this study we investigated the effect of lesioning the noradrenergic systems on the behavioral effects of (5R, 10S)-(+)-5-Methyl-10,11-dihydro-5H-dibenzo [a, d] cyclohepten-5,10-imine hydrogen maleate--MK-801, in rats. The noradrenergic system was lesioned with N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine hydrochloride--DSP4 (60 mg/kg IP). MK-801 increased the locomotor activity and rearing. DSP4 significantly further increased the hyperlocomotor activity, circling (especially to the left side), sniffing, rolling, and falling that were induced by MK-801. These results showed that destruction of the noradrenergic system increased MK-801-hyperlocomotor activity, ataxia and stereotypy.