Evaluation of ALK gene rearrangement in central nervous system metastases of non-small-cell lung cancer using two-step RT-PCR technique

Purpose. RT-PCR technique has showed a promising value as pre-screening method for detection of mRNA containing abnormal ALK sequences, but its sensitivity and specificity is still discussable. Previously, we determined the incidence of ALK rearrangement in CNS metastases of NSCLC using IHC and FISH methods. Materials. We evaluated ALK gene rearrangement using two-step RT-PCR method with EML4-ALK Fusion Gene Detection Kit (Entrogen, USA). The studied group included 145 patients (45 females, 100 males) with CNS metastases of NSCLC and was heterogeneous in terms of histology and smoking status. Results. 21% of CNS metastases of NSCLC (30/145) showed presence of mRNA containing abnormal ALK sequences. FISH and IHC tests confirmed the presence of ALK gene rearrangement and expression of ALK abnormal protein in seven patients with positive result of RT-PCR analysis (4.8% of all patients, 20% of RT-PCR positive patients). RT-PCR method compared to FISH analysis achieved 100% of sensitivity and only 82.7% of specificity. IHC method compared to FISH method indicated 100% of sensitivity and 97.8% of specificity. In comparison to IHC, RT-PCR showed identical sensitivity with high number of false positive results. Conclusion. Utility of RT-PCR technique in screening of ALK abnormalities and in qualification patients for molecularly targeted therapies needs further validation (AU)

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Evaluation of ALK gene rearrangement in central nervous system metastases of non-small-cell lung cancer using two-step RT-PCR technique.

PURPOSE: RT-PCR technique has showed a promising value as pre-screening method for detection of mRNA containing abnormal ALK sequences, but its sensitivity and specificity is still discussable. Previously, we determined the incidence of ALK rearrangement in CNS metastases of NSCLC using IHC and FISH methods. MATERIALS: We evaluated ALK gene rearrangement using two-step RT-PCR method with EML4-ALK Fusion Gene Detection Kit (Entrogen, USA). The studied group included 145 patients (45 females, 100 males) with CNS metastases of NSCLC and was heterogeneous in terms of histology and smoking status. RESULTS: 21% of CNS metastases of NSCLC (30/145) showed presence of mRNA containing abnormal ALK sequences. FISH and IHC tests confirmed the presence of ALK gene rearrangement and expression of ALK abnormal protein in seven patients with positive result of RT-PCR analysis (4.8% of all patients, 20% of RT-PCR positive patients). RT-PCR method compared to FISH analysis achieved 100% of sensitivity and only 82.7% of specificity. IHC method compared to FISH method indicated 100% of sensitivity and 97.8% of specificity. In comparison to IHC, RT-PCR showed identical sensitivity with high number of false positive results. CONCLUSION: Utility of RT-PCR technique in screening of ALK abnormalities and in qualification patients for molecularly targeted therapies needs further validation.

Sensitive methods for screening of the MEK1 gene mutations in patients with central nervous system metastases of non-small cell lung cancer

Background: The mitogen-activated protein kinases 1 and 2 (MEK1, MEK2) are fundamental partners in the RAS-RAF-MEK-ERK pathway that is involved in regulation of cell proliferation, differentiation and survival. Downregulation of the MEK cascades has been implicated in acquiring of the malignant phenotype in various cancers. Somatic mutations in MEK1 gene (substitutions K57N, Q56P, D67N) were described in < 1 % of non-small cell lung cancer (NSCLC) and they were more commonly reported in adenocarcinoma patients with current or former smoking status. Materials and methods: In the following study, we assessed the MEK1 gene mutations in 145 FFPE tissue samples from central nervous system (CNS) metastases of NSCLC using HRM-PCR and ASP-qPCR techniques. The studied group was heterogeneous in terms of histopathology and smoking status. The prevalence of the MEK1 gene mutation was correlated with the occurrence of mutations in KRAS, EGFR, DDR2, PIK3CA, NRAS, HER2, AKT1 and PTEN genes. Results: Using HRM and ASP-qPCR methods we identified one (0.7 %; 1/145) MEK1 substitution (Q56P) in CNS metastases of NSCLC. The mutation was identified in a single, 50-year-old, current smoking men with adenocarcinoma (1.25 %; 1/80 of all adenocarcinomas). Conclusions: According to the current knowledge, the incidence of MEK1 gene mutation in CNS metastatic lesion of NSCLC is the first such report worldwide. The analysis of gene profile in cancer patients may extend the scope of molecularly targeted therapies used both in patients with primary and metastatic tumors of NSCLC (AU)

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Sensitive methods for screening of the MEK1 gene mutations in patients with central nervous system metastases of non-small cell lung cancer.

BACKGROUND: The mitogen-activated protein kinases 1 and 2 (MEK1, MEK2) are fundamental partners in the RAS-RAF-MEK-ERK pathway that is involved in regulation of cell proliferation, differentiation and survival. Downregulation of the MEK cascades has been implicated in acquiring of the malignant phenotype in various cancers. Somatic mutations in MEK1 gene (substitutions K57N, Q56P, D67N) were described in <1 % of non-small cell lung cancer (NSCLC) and they were more commonly reported in adenocarcinoma patients with current or former smoking status. MATERIALS AND METHODS: In the following study, we assessed the MEK1 gene mutations in 145 FFPE tissue samples from central nervous system (CNS) metastases of NSCLC using HRM-PCR and ASP-qPCR techniques. The studied group was heterogeneous in terms of histopathology and smoking status. The prevalence of the MEK1 gene mutation was correlated with the occurrence of mutations in KRAS, EGFR, DDR2, PIK3CA, NRAS, HER2, AKT1 and PTEN genes. RESULTS: Using HRM and ASP-qPCR methods we identified one (0.7 %; 1/145) MEK1 substitution (Q56P) in CNS metastases of NSCLC. The mutation was identified in a single, 50-year-old, current smoking men with adenocarcinoma (1.25 %; 1/80 of all adenocarcinomas). CONCLUSIONS: According to the current knowledge, the incidence of MEK1 gene mutation in CNS metastatic lesion of NSCLC is the first such report worldwide. The analysis of gene profile in cancer patients may extend the scope of molecularly targeted therapies used both in patients with primary and metastatic tumors of NSCLC.

Cowden syndrome and the associated Lhermitte-Duclos disease--Case presentation.

We report a patient with features of Cowden syndrome (CS). A 35-year old woman has been suffering from headache, vertigo and mild imbalance since 2 years. Examination showed subtle mucocutaneous lesions: papillomatous papules on the gingival mucosa, a few verrucous acral skin lesions and macrocephaly. Magnetic resonance imaging (MRI) revealed a tumor of the left cerebellar hemisphere with "tiger-striped" pattern on T2-weighted image (T2WI), typical of Lhermitte-Duclos disease (LDD)--one of the pathognomonic but infrequent features of CS. A pathogenic de novo heterozygous PTEN mutation: c.49C>T variant has been identified in exon 1 of the PTEN gene by sequencing.

How intracranial aneurysm rupture damages the brain.

SUMMARY: Intracranial aneurysm rupture causes arterial bleeding into the subarachnoid space (SAH). In the acute stage lasting around 5 minutes intracranial pressure (ICP) rises rapidly up to the level between systolic and diastolic blood pressures, which slows down the outflow of blood, facilitates clot formation in the site of rupture and leads to arrest of bleeding. Increased ICP lowers cerebral perfusion pressure, causing brain ischemia, which is unevenly distributed throughout the brain as a result of interhemispheric pressure gradients, arterial spasms and other factors. No-reflow phenomenon in the capillaries following temporary arrest or considerable slowing of circulation produces areas of hypoperfusion and reduced capacity of blood flow autoregulation scattered irregularly in the brain in the subacute stage up to 30 minutes following haemorrhage. Disturbed regional cerebral blood flow is accompanied by spots of damaged blood brain barrier resulting in brain oedema. After SAH the brain remains vulnerable to reduction of blood flow and hypoxaemia, which explains greater brain damage after secondary haemorrhage, and in some cases persistent neurological deficits or global brain dysfunction.

Cerebrospinal fluid and blood propofol concentration during total intravenous anaesthesia for neurosurgery.

BACKGROUND: The aim of this paper is to compare the propofol concentration in blood and cerebrospinal fluid (CSF) in patients scheduled for different neurosurgical procedures and anaesthetized using propofol as part of a total intravenous anaesthesia technique. METHODS: Thirty-nine patients (ASA I-III) scheduled for elective intracranial procedures, were studied. Propofol was infused initially at 12 mg kg(-1) h(-1) and then reduced in steps to 9 and 6 mg kg(-1) h(-1). During anaesthesia, bolus doses of fentanyl and cis-atracurium were administered as necessary. After tracheal intubation the lungs were ventilated to achieve normocapnia with an oxygen-air mixture (FI(O(2))=0.33). Arterial blood and CSF samples for propofol examination were obtained simultaneously directly after intracranial drainage insertion and measured using high-performance liquid chromatography. The patients were divided into two groups depending on the type of neurosurgery. The Aneurysm group consisted of 13 patients who were surgically treated for ruptured intracranial aneurysm. The Tumour group was composed of 26 patients who were undergoing elective posterior fossa extra-axial tumour removal. RESULTS: Blood propofol concentrations in both groups did not differ significantly (P>0.05). The propofol concentration in CSF was 86.62 (SD 37.99) ng ml(-1) in the Aneurysm group and 50.81 (26.10) ng ml(-1) in the Tumour group (P<0.005). CONCLUSIONS: Intracranial pathology may influence CSF propofol concentration. However, the observed discrepancies may also result from quantitative differences in CSF composition and from restricted diffusion of the drug in the CSF.

Endovascular treatment of giant p1/p2 aneurysm by direct puncture of the vertebral artery. Case report.

SUMMARY: Vascular access is usually achieved through a femoral arterial puncture using a modified Seldinger technique. However, selective catheterization of the great cerebral vessels by femoral approach fails completely when the vessel is tortuous or atheromatous. In case of posterior vascular circulation aneurysms, transbrachial approach or direct puncture of the vertebral artery (VA) is an alternative. The aneurysms of the posterior cerebral artery (PCA) are reported to be rare. Due to unfavorable anatomic location, the PCA aneurysms are difficult to reach during surgical procedure. Endovascular embolization is at present considered to be more effective and safer treatment of the PCA aneurysms arising from different segments, offering a viable alternative to the surgical approach. We report the case of the giant left PCA aneurysm, located at the junction of P1/P2 segments, successfully treated by parent artery occlusion achieved after the direct puncture of the right VA which was used because both VAs were tortuous, irregular and their ostia were not accessible by femoral approach. According to different authors, parent artery occlusion appears to be safe in the treatment of P2 segment aneurysms, whatever the location of the occlusion. In our case we decided to perform this kind of treatment believing it was the only possible one.

Spontaneous Thrombosis of the Pseudoaneurysm of Right SCA after an Attempt at Embolisation. A Case Report.

SUMMARY: Spontaneous thrombosis of intracranial aneurysms rare, mostly affecting giant aneurysms with narrow necks. We present the case of 34 y/o man with pseudoaneurysm that developed in the course of SAH. The initial CT scan showed an isolated, well-defined hematoma within the right cerebellar hemisphere, digital subtraction angiogram (DSA) performed in a regional hospital showed an irregular shaped aneurysm of the distal segment of the right SCA. The patient was sent to our department, where diagnostic DSA, performed before embolisation revealed an entirely different morphology of the aneurysm. It became larger, round and no other functional branches distal to it were found (picture of "a balloon on a string"). During supraselective catheterization, when microcatheter and microguidewire were already in the right SCA a technical problem of our angio-machine occurred, so the intervention had to be postponed. A week later, a second attempt at embolisation was made. This time an initial DSA showed a lack of filling of the aneurysm sac and thrombosis of the main trunk of the right SCA. The patient remained clinically stable. He was discharged from our hospital five days later.

Intensive care management of head-injured patients in Europe: a survey from the European brain injury consortium.

OBJECTIVES: (a) to describe current practice in the monitoring and treatment of moderate and severe head injuries in Europe; (b) to report on intracranial pressure and cerebral perfusion pressure monitoring, occurrence of measured and reported intracranial hypertension, and complications related to this monitoring; (c) to investigate the relationship between the severity of injury, the frequency of monitoring and management, and outcome. METHODS: A three-page questionnaire comprising 60 items of information has been compiled by 67 centres in 12 European countries. Information was collected prospectively regarding all severe and moderate head injuries in adults (> 16 years) admitted to neurosurgery within 24 h of injury. A total of 1005 adult head injury cases were enrolled in the study from 1 February 1995 to 30 April 1995. The Glasgow Outcome Scale was administered at 6 months. RESULTS: Early surgery was performed in 346 cases (35%); arterial pressure was monitored invasively in 631 (68%), ICP in 346 (37%), and jugular bulb saturation in 173 (18%). Artificial ventilation was provided to 736 patients (78%). Intracranial hypertension was noted in 55% of patients in whom ICP was recorded, while it was suspected in only 12% of cases without ICP measurement. There were great differences in the use of ventilation and CPP monitoring among the centres. Mortality at 6 months was 31%. There was an association between an increased frequency of monitoring and intervention and an increased severity of injury; correspondingly, patients who more frequently underwent monitoring and ventilation had a less favourable outcome. CONCLUSIONS: In Europe there are great differences between centres in the frequency of CPP monitoring and ventilatory support applied to head-injured patients. ICP measurement disclosed a high rate of intracranial hypertension, which was not suspected in patients evaluated on a clinical basis alone. ICP monitoring was associated with a low rate of complications. Cases with severe neurological impairment, and with the worse outcome, were treated and monitored more intensively.

[Assessment of p53 dependent apoptosis in glia-derived tumors of the brain]. / Ocena zjawiska apoptozy w glejopochodnych guzach mózgu w oparciu o badanie antyonkogenu p53.

There are conflicting reports in connection with the association of the p53 tumour suppressor gene mutation with the clinical and histopathological progression of gliomas. Glia-derived neoplasms frequently show mutational changes in the p53 gene which result in enhancement of tumorigenesis. The aim of the paper was an assessment of the frequency of mutations in the exon 8 of this gene. The specimens from 14 patients operated for glial tumors were investigated by polymerase chain reaction-assisted--single strand conformation polymorphism (PCR-SSCP). We found aberrant bands in 64.3% of specimens. The percentage of mutations was similar in patients with benign and malignant tumours. There was no correlation between the alteration of the gene and intensity of necrosis in histological examination in patients with glioblastoma. Changes in activity of the p53 gene were more frequent in younger patients and in males when compared to women.

[Expression of bcl-2 gene in glia-derived tumors of the brain]. / Ekspresja genu bcl-2 w glejopochodnych guzach mózgu.

Bcl-2 gene is an important factor in regulation of apoptosis as an inhibitor of this process. Its increased expression is observed in numerous neoplasms, what points out on importance of this gene in the process of oncogenesis. The aim of this paper was to assess the expression of bcl-2 gene in the cells of the glia-derived tumours of the brain. The method of Chomczynski and Sacchi with guanidine tiocyanate was applied to isolate a whole cellular RNA. Expression of bcl-2 gene was measured with a reverse transcription method by a synthesis of cDNA and amplification of gene fragment with specific oligonucleotides in polymerase chain reaction (RT-PCR). The expression of bcl-2 gene was found in cells of all examined glial tumours at the level of transcript. We carried out the discussion of the results and an attempt to explain the importance of bcl-2 gene expression of these neoplasms.

[The application and evaluation of TachoComb in repair of lacerations of dural sac]. / Zastosowanie i ocena przydatnosci Tachocombu w operacyjnym zaopatrywaniu uszkodzen worka oponowego.

The opening of dural sac (deliberate or accidental) during operation of the spine should be watertightly closed because of the risk of cerebro-spinal fluid leakage and infectious complications. Suturing the dural sac is sometimes difficult and time-consuming in cases of dural sac lacerations in a narrow confined space or in the proximity of radices. This occurs particularly in the case of reoperation in presence of scar involving the dural sac, that increases the risk of laceration. The aim of this paper is to asses the usefulness of a new sealing and haemostatic material--TachoComb in a watertight closure of the dural sac during spinal operation. We compared the frequency of complications related to closing of the dural sac in patients operated before and after introduction of TachoComb. The results indicate that the rate of liquorrhoea and infections is lower in the postoperative period with addition of TachoComb. Addition of TachoComb allows to shorten the time of operation, while its application is relatively easy.

Continuing education--the EANS concepts.

Continuing Medical Education (CME) is becoming to be an important part of professional conduct of neurosurgeons in the member countries of EANS. It is therefore a task for the EANS to harmonize various systems of CME and to offer a compatible programme of continuing education that would meet the expectations and needs of the neurosurgeons. It should help choose fields in which updating knowledge is indispensable, offer teaching and training opportunities and provide systems of evaluation and certification of progress in neurosurgical CME.

[The influence of radiation doses on the results of radiosurgery of brain arteriovenous malformations]. / Wplyw dawki promieniowania na wyniki radiochirurgicznego leczenia naczyniaków mózgu.

Stereotactic radiosurgery as a method of treatment of inoperable brain angiomas has been in use in the Neurosurgery Department, Medical Academy in Lublin since 1990. The patients receive radiation from a Neptune 10P linear accelerator of 9 MeV photon energy (X radiation). The Laitinen stereoadapter used by us makes possible precise targeting and radiation application in time suitable for the patient and the whole treatment team. This frame produces no disturbances of CT image and is not covering the target. Non-invasive head immobilization in the frame is highly stable, although it requires good communication with the patient and his full cooperation. The purpose of the study was a comparison of the results of radiosurgery applied in the treatment of inoperable brain angiomas of various size with radiation doses 4000 cGy and 3000 cGy. The material comprises 40 first cases out of over 120 patients treated in this way for inoperable angiomas. The first group of 20 patients received 4000 cGy and the second group of 20 patients received 3000 cGy doses. Complete obliteration of angiomas was achieved in 16 (80%) cases treated with the 4000 cGy dose, and in 17 (85%) cases treated with the 3000 cGy dose. Late postradiation reactions developed in 15 (75%) patients in the first group with permanent changes in 5 (25%) patients. In the second group late postradiation reactions developed in only 6 (30%) cases and regressed in all. Treatment effectiveness (complete obliteration) after doses of 3000 and 4000 cGy was similar, and it decreased with greater size of angiomas. The per cent of postradiation complications after lower doses was much smaller, and permanent neurological changes were seen only after higher doses. The obtained results of the method are comparable with those of the authors using invasive methods of fixation of stereotactic frames.