Bożena Jarosz

Therapeutic doses of topiramate are not toxic to the developing rat brain.

Antiepileptic drugs (AEDs) used to treat seizures in pregnant women, infants, and young children may cause cognitive impairment. One of the implicated mechanisms is enhancement of apoptotic neuronal death, which occurs physiologically in the developing brain. We investigated whether topiramate, one of the newer antiepileptic drugs, has neurotoxic properties in the developing rat brain. Topiramate slightly but significantly enhanced apoptotic neuronal death in the 7-day-old rat brain at doses of 50 mg/kg and above. These doses are several folds higher than reported ED(50) doses in infant rodent seizure models that respond to topiramate. Electron microscopy confirmed that dying neurons following topiramate treatment displayed the same morphological features as neurons undergoing physiological cell death during development. When compared to the neurotoxicity profile of phenytoin, valproate, and phenobarbital, the separation between the effective anticonvulsant dose and the neurotoxic dose was greater for topiramate and the neurotoxic effect was lower.

Anticancer agents are potent neurotoxins in vitro and in vivo

Neurotoxicity of anticancer agents complicates treatment of children with cancer. We investigated neurotoxic effects of common cytotoxic drugs in neuronal cultures and in the developing rat brain. When neurons were exposed to cisplatin (5–100μM), cyclophosphamide (5–100μM), methotrexate (5–100μM), vinblastin (0.1–1μM), or thiotepa (5–100μM), a concentration‐dependent neurotoxic effect was observed. Neurotoxicity was potentiated by nontoxic glutamate concentrations. The N‐methyl‐D‐aspartate receptor antagonist MK 801 (10μM), the AMPA receptor antagonists GYKI 52466 (10μM) and NBQX (10μM), and the pancaspase inhibitor Ac‐DEVD‐CHO (1nM) ameliorated neurotoxicity of cytotoxic drugs. To investigate neurotoxicity in vivo, we administered to 7‐day‐old rats the following: cisplatin (5–15mg/kg IP), cyclophosphamide (200–600mg/kg IP), thiotepa (15–45mg/kg), or ifosfamide (100–500mg/kg) and their brains were analyzed at 4 to 24 hours. Cytotoxic drugs produced widespread lesions within cortex, thalamus, hippocampal dentate gyrus, and caudate nucleus in a dose‐dependent fashion. Early histological analysis demonstrated dendritic swelling and relative preservation of axonal terminals, which are morphological features indicating excitotoxicity. After longer survival periods, degenerating neurons displayed morphological features consistent with active cell death. These results demonstrate that anticancer drugs are potent neurotoxins in vitro and in vivo; they activate excitotoxic mechanisms but also trigger active neuronal death. Ann Neurol 2004

Conversion of epidermal growth factor receptor 2 and hormone receptor expression in breast cancer metastases to the brain

IntroductionWe investigated the status of estrogen receptor alpha (ERα), progesterone receptor (PR), and epidermal growth factor receptor 2 (HER2) in primary tumor and in the corresponding brain metastases in a consecutive series of breast cancer patients. Additionally, we studied factors potentially influencing conversion and evaluated its association with survival.MethodsThe study group included 120 breast cancer patients. ERα, PR, and HER2 status in primary tumors and in matched brain metastases was determined centrally by immunohistochemistry and/or fluorescence in situ hybridization.ResultsUsing the Allred score of ≥ 3 as a threshold, conversion of ERα and PR in brain metastases occurred in 29% of cases for both receptors, mostly from positive to negative. Conversion of HER2 occurred in 14% of patients and was more balanced either way. Time to brain relapse and the use of chemotherapy or trastuzumab did not influence conversion, whereas endocrine therapy induced conversion of ERα (P = 0.021) and PR (P = 0.001), mainly towards their loss. Receptor conversion had no significant impact on survival.ConclusionsReceptor conversion, particularly loss of hormone receptors, is a common event in brain metastases from breast cancer, and endocrine therapy may increase its incidence. Receptor conversion does not significantly affect survival.

Kynurenic acid inhibits proliferation and migration of human glioblastoma T98G cells.

BACKGROUND Kynurenic acid (KYNA), tryptophan metabolite synthesized in the kynurenine pathway, is an endogenous antagonist of α-7 nicotinic receptor and all ionotropic glutamate receptors: N-methyl-D-aspartate (NMDA) receptor, α-amino-3-hydroxy-5-methyl-4-isoxasole propionate (AMPA) receptor and kainate receptor. The antiproliferative activity of KYNA toward colon and renal cancer cells has recently been discovered. The aim of the study was to verify whether human Glioblastoma tumors contain KYNA and if KYNA influences glioma cell proliferation and migration. METHODS KYNA content in Glioblastoma tumor samples was determined using HPLC. Proliferation of human glioblastoma T98G cells was measured by means of MTT and BrdU assays. Wound assay was used to evaluate the effect of KYNA on cancer cell migration. RESULTS KYNA was detected in all tested Glioblastoma tumor samples (100.3 ± 17.6 pmol/g wet weight). In a series of experiments the antiproliferative activity of KYNA against T98G cells was revealed (IC(50) = 1.3 mM). Moreover, KYNA reversed the stimulatory effect of glutamate on glioma cell proliferation and enhanced antiproliferative effect of glutamate receptor antagonists MK801 and GYKI 52466. Next, KYNA at concentrations much lower than those needed to reduce cell proliferation elicited a prominent inhibitory effect on glioma cell motility. Moreover, co-incubation of temozolomide, a drug commonly used in antiglioblastoma therapy, with KYNA gave a superior effect than each of the substances applied alone. CONCLUSIONS We demonstrate the antiproliferative and antimigrative potential of KYNA against glioma cells in vitro.

Quantitative HER2 and p95HER2 levels in primary breast cancers and matched brain metastases

BACKGROUND Patients with advanced breast cancer positive for human epidermal growth factor receptor 2 (HER2) are at high risk for brain metastasis (BM). The prevalence and significance of expression of HER2 and its truncated form p95HER2 (p95) in BM is unknown. METHODS Seventy-five pairs of formalin-fixed paraffin-embedded samples from matched primary breast cancers (PBCs) and BM were assayed for quantitative p95 and HER2-total (H2T) protein expression using the p95 VeraTag and HERmark assays, respectively. RESULTS There was a net increase in p95 and H2T expression in BM relative to the matched PBC (median 1.5-fold, P = .0007 and 2.1-fold, P < .0001, respectively). Cases with H2T-positive tumors were more likely to have the largest (≥5-fold) increase in p95 (odds ratio = 6.3, P = .018). P95 positivity in PBC correlated with progression-free survival (hazard ratio [HR] = 2.2, P = .013), trended with shorter time to BM (HR = 1.8, P = .070), and correlated with overall survival (HR = 2.1, P = .042). P95 positivity in BM correlated with time to BM (HR = 2.0, P = .016) but did not correlate with overall survival from the time of BM diagnosis (HR = 1.2, P = .61). CONCLUSIONS This is the first study of quantitative p95 and HER2 expression in matched PBC and BM. BM of breast cancer shows significant increases in expression of both biomarkers compared with matched PBC. These data provide a rationale for future correlative studies on p95 and HER2 levels in BM.

An in vivo model of anti-inflammatory activity of subdural dexamethasone following the spinal cord injury

Current therapies to limit the neural tissue destruction following the spinal cord injury are not effective. Our recent studies indicate that the injury to the white matter of the spinal cord results in a severe inflammatory response where macrophages phagocytize damaged myelin and the fluid-filled cavity of injury extends in size with concurrent and irreversible destruction of the surrounding neural tissue over several months. We previously established that a high dose of 4mg/rat of dexamethasone administered for 1 week via subdural infusion remarkably lowers the numbers of infiltrating macrophages leaving large amounts of un-phagocytized myelin debris and therefore inhibits the severity of inflammation and related tissue destruction. But this dose was potently toxic to the rats. In the present study the lower doses of dexamethasone, 0.125-2.0mg, were administered via the subdural infusion for 2 weeks after an epidural balloon crush of the mid-thoracic spinal cord. The spinal cord cross-sections were analyzed histologically. Levels of dexamethasone used in the current study had no systemic toxic effect and limited phagocytosis of myelin debris by macrophages in the lesion cavity. The subdural infusion with 0.125-2.0mg dexamethasone over 2 week period did not eliminate the inflammatory process indicating the need for a longer period of infusion to do so. However, this treatment has probably lead to inhibition of the tissue destruction by the severe, prolonged inflammatory process.

Increase in intra-abdominal pressure raises brain venous pressure, leads to brain ischaemia and decreases brain magnesium content.

BACKGROUND Intra-abdominal hypertension (IAH) may increase brain venous pressure, which may lead to brain injury. The aim of the present study was to analyse the effect of IAH on brain venous pressure and brain total and ionised magnesium (tMg and iMg), calcium (Ca) and zinc (Zn) contents in rats. MATERIAL AND METHODS Forty four adult Wistar rats were examined. Animals were divided into two groups: control, and IAH: rats with intra-abdominal pressure (IAP) elevated to 25 mmHg. IAP was measured directly in the abdominal cavity. After retrograde cannulation of the jugular vein, the jugular venous pressure (JVP) was measured as the brain venous pressure. JVP and IAP were noted after induction of anaesthesia, immediately following induction of IAH and 90 min after induction of IAH. In all rats, brains were removed for biochemical and histological analysis. RESULTS Biochemical analysis was performed in 30 rats, histological visualisation in 14. IAP elevated to 25 mmHg increased JVP in the IAH group. After 90 min, JVP decreased; however, its value was still higher compared with pre-IAH. In the IAH group, tMg and iMg were significantly lower than in the control group. Moreover, Ca and Zn levels were higher in the IAH group compared with the control group. The histological examination showed changes indicative of ischaemic neuronal cell stress. CONCLUSIONS Firstly, increase in IAP elevates JVP. Secondly, raised JVP decreases tMg and iMg. Thirdly, raised JVP increases the Ca and Zn content in the rat brain. Fourthly, IAH leads to changed characteristics of brain ischaemia.

Prevalence of rare EGFR gene mutations in nonsmall-cell lung cancer: a multicenter study on 3856 Polish Caucasian patients

Department of Pneumonology, Oncology and Allergology, Medical University of Lublin, Poland GENIM Ltd. Institute of Genetics and Immunology, Lublin, Poland Department of Clinical Oncology, Medical University of Poznan, Poland Department of Pathology, Specialist Pulmonary Hospital of Sokolowski, Zakopane, Poland Regional Centre of Oncology M. Kopernik Hospital, Lodz, Poland Mazovian Centre for Treatment of Lung Diseases and Tuberculosis, Otwock, Poland Department of Neurosurgery and Pediatric Neurosurgery, Medical University of Lublin, Poland E.J. Zeyland Wielkopolska Center of Pulmonology and Thoracic Surgery, Poznan, Poland Regional Oncology Centre in Gdansk, Poland Department of Clinical Patomorphology, Medical University of Lublin, Poland

Quantitative HER2 levels and steroid receptor expression in primary breast cancers and in matched brain metastases.

603 Background: MMR deficiency (dMMR) has been reported in 15% of CRC, but with a lower frequency in advanced disease. Most cases are due to sporadic MLH1 promoter hypermethylation (often with BRAF mutations), with a minority reflecting germline mutations in MLH1, MSH2, PMS2, or MSH6 (Lynch Syndrome [LS]). The Revised Bethesda Guidelines (RBG) are one means of selecting individuals at risk of LS for further assessment, but will miss a proportion of cases. METHODS We screened all consenting patients for eligibility for CRC trials recruiting specific genetic aberrations, which included MMR assessment. RESULTS Of 314 patients, immunohistochemistry (IHC) for MMR protein expression is complete on 171. Staining was reduced/absent in 19.3% of tests, and heterogeneous in 12.1%. The dMMR rate was 6.4%. 2 dMMR patients* were identified as at risk of LS, and referred to genetics by their treating clinician before IHC results were known. However 4 other cases† were not referred, and an underlying predisposition would have been missed without this unbiased approach. 4 patients developed metastatic disease, with none experiencing a partial response to chemotherapy thus far. (Table.) Conclusions: This data is representative of a practice with a high proportion of metastatic disease. It suggests that within oncology, an unbiased screening approach for LS is preferable. Whilst the RBG detect the majority of cases, they may be underutilised as other management issues take precedence in oncology clinics. A cost-effective alternative may be the introduction of a nurse-led programme to identify cases at risk, as is being introduced at our centre. A spectrum of clinical behavior exists amongst metastatic dMMR CRC, and larger numbers will reveal if this affects therapeutic response. [Table: see text].

Langerhans cell histiocytosis of the parietal bone with epidural and extracranial expansion – case report and a review of the literature

Langerhans cell histiocytosis is a rare neoplasm that belongs to the histiocytic and dendritic cell neoplasm group according to the 2008 WHO classification. It has been defined as neoplastic proliferation of Langerhans cells that express CD1a and S-100 proteins and have Birbeck granules on the ultrastructural examination. Clinical presentation and behaviour are heterogeneous and can range from a solitary lytic bone lesion with a favourable course to a fatal disseminated leukaemia-like form, with a wide spectrum of intermediate clinical presentations between these two extremes. Here, we present a case report of a solitary calvarial lesion in an adolescent boy along with a review of the literature. Presenting features, initial diagnostic evaluation and treatment protocol of a unifocal monosystemic calvarial location of LCH are presented.