Epigenetic Downregulation of Hsa-miR-193b-3p Increases Cyclin D1 Expression Level and Cell Proliferation in Human Meningiomas.

Meningiomas are common intracranial tumors in adults. Abnormal microRNA (miRNA) expression plays a role in their pathogenesis. Change in miRNA expression level can be caused by impaired epigenetic regulation of miRNA-encoding genes. We found the genomic region covering the MIR193B gene to be DNA hypermethylated in meningiomas based on analysis of genome-wide methylation (HumanMethylation450K Illumina arrays). Hypermethylation of MIR193B was also confirmed via bisulfite pyrosequencing. Both hsa-miR-193b-3p and hsa-miR-193b-5p are downregulated in meningiomas. Lower expression of hsa-miR-193b-3p and higher MIR193B methylation was observed in World Health Organization (WHO) grade (G) II/III tumors as compared to GI meningiomas. CCND1 mRNA was identified as a target of hsa-miR-193b-3p as further validated using luciferase reporter assay in IOMM-Lee meningioma cells. IOMM-Lee cells transfected with hsa-miR-193b-3p mimic showed a decreased cyclin D1 level and lower cell viability and proliferation, confirming the suppressive nature of this miRNA. Cyclin D1 protein expression (immunoreactivity) was higher in atypical than in benign meningiomas, accordingly to observations of lower hsa-miR-193b-3p levels in GII tumors. The commonly observed hypermethylation of MIR193B in meningiomas apparently contributes to the downregulation of hsa-miR-193b-3p. Since hsa-miR-193b-3p regulates proliferation of meningioma cells through negative regulation of cyclin D1 expression, it seems to be an important tumor suppressor in meningiomas.

The Influence of Heat Treatment on Low Cycle Fatigue Properties of Selectively Laser Melted 316L Steel.

The paper is a project continuation of the examination of the additive-manufactured 316L steel obtained using different process parameters and subjected to different types of heat treatment. This work contains a significant part of the research results connected with material analysis after low-cycle fatigue testing, including fatigue calculations for plastic metals based on the Morrow equation and fractures analysis. The main aim of this research was to point out the main differences in material fracture directly after the process and analyze how heat treatment affects material behavior during low-cycle fatigue testing. The mentioned tests were run under conditions of constant total strain amplitudes equal to 0.30%, 0.35%, 0.40%, 0.45%, and 0.50%. The conducted research showed different material behaviors after heat treatment (more similar to conventionally made material) and a negative influence of precipitation heat treatment of more porous additive manufactured materials during low-cycle fatigue testing.

Comparison of Different Heat Treatment Processes of Selective Laser Melted 316L Steel Based on Analysis of Mechanical Properties.

In this study, we analyzed the mechanical properties of selectively laser melted (SLM) steel obtained via different modifications during and after the manufacturing process. The aim was to determine the effects of precipitation heat treatment on the mechanical properties of elements additively manufactured using three different process parameters. Some samples were additionally obtained using hot isostatic pressing (HIP), while some were treated using two different types of heat treatment and a combination of those two processes. From each manufactured sample, a part of the material was taken for structural analysis including residual stress analysis and microstructural investigations. In the second part of the research, the mechanical properties were studied to define the scleronomic hardness of the samples. Finally, tensile tests were conducted using a digital image correlation (DIC) test and fracture analysis. The treated samples were found to be significantly elongated, thus indicating the advantages of using precipitation heat treatment. Additionally, precipitation heat treatment was found to increase the porosity of samples, which was the opposite compared to HIP-treated samples.

Motor cortex stimulation in the treatment of neuropathic pain.

BACKGROUND AND PURPOSE: Despite the rapid development of neuropharmacotherapy, medical treatment of neuropathic pain (NP) still constitutes a significant socioeconomic problem. The authors herein present a group of patients treated with motor cortex stimulation (MCS) for NP of various types and aetiologies. MATERIAL AND METHODS: Our cohort included 12 female and 11 male NP patients aged 53 ± 16 treated with MCS. Eleven patients were diagnosed with neuropathic facial pain (NFP), 8 with hemi-body neuropathic pain (HNP), and 4 with deafferentation pain (DP). Prior to surgery, 16 out of 23 patients were treated with repetitive transcranial magnetic stimulation (rTMS), with a positive response in 10 cases. Pain intensity in our group was evaluated with the visual analogue scale (VAS) one month before and three months after MCS implantation. RESULTS: Improvement on the VAS was reported in the whole group of patients (p < 0.001). The best results were reported in the NFP group (p < 0.001) while the worst ones were noted in the DP group (p = 0.04). Anamnesis duration positively correlated with outcome. Infection forced the authors to permanently remove the system in one case. There were no other complications in the group. CONCLUSIONS: Minimally invasive, safe neuromodulative treatment with MCS permits neuropathic pain control with good efficacy. The type of neuropathic pain might be a prognostic factor.

Statistical analysis of the intracranial procedures in Poland in 2008-2009.

BACKGROUND AND PURPOSE: Quantitative and qualitative analysis of neurosurgical procedures provides important data for assessment of the development and trends in the field of neurosurgery. The authors present statistical data on intracranial procedures (IPs) performed in Poland in 2008-2009. MATERIAL AND METHODS: Data on IPs come from reports of the National Health Fund, grouped according to the system of Diagnosis-Related Groups, group A - nervous system diseases. Data concerning the year 2009 include all IPs performed in Poland. Data from the second half of 2008 to 2009 (18 months) come from 35 neurosurgical centers in Poland, divided by provinces. We analyzed the number of IPs, the cost of procedures, duration of hospitalization and deaths. RESULTS: 20 849 IPs were performed in Poland in 2009. The most common procedure was A12 (6807; 32.65%), and the rarest was A04 (96; 0.46%). The annual cost of all IPs was 228 599 956 PLN. Average cost of the procedure ranged from 1578 PLN (A14) to 47 940 PLN (A03). Duration of the hospitalization ranged between 3 days (A14) and 12 days (A12). The highest percentage of deaths was reported for A01 (n = 1050, 19.06%). Reports from 35 neurosurgical centers in the second half of 2008 and 2009 showed the highest number of IPs per 100 000 population in Kujawsko-Pomorskie (93) and the lowest in Wielkopolskie (27) and Podkarpackie (27). The highest number of IPs (1669) was performed in neurosurgical center M1 (Malopolskie), and the lowest (99) in W1 (Wielkopolskie). CONCLUSIONS: A significant disparity in the number of IPs performed in different centers in Poland was observed.

Rosette-forming glioneuronal tumor of the fourth ventricle with advanced microvascular proliferation--a case report.

Rosette-forming glioneuronal tumor (RGNT) of the fourth ventricle is a recently described novel type of primary brain tumor that was included into the current WHO classification of CNS tumors. It is a very rare, slowly growing, mixed neoplasm at cerebellar localization with distinctive morphological pattern. We present an unusual case of a 20-year-old patient with RNGT of the fourth ventricle with advanced microvascular proliferation. MRI revealed the solid-cystic tumor mass largely involving the cerebellar vermis and left hemisphere with compression of the fourth ventricle. Microscopically, the tumor showed classical architectural pattern with two distinctive components. The main component consisted of neurocytic rosettes formed by round, isomorphic nuclei arranged around eosinophilic, fibrillar cores with strong synaptophysin expression. The perivascular rosettes with cell arrangement along blood vessels were observed only sporadically. The second neoplastic component consisted of spindle or stellate astroglial cells with piloid process and Rosenthal fibers, strongly resembling pilocytic astrocytoma. Focally, the astroglial cells showed increased cellularity but without marked nuclear atypia. The glial part of the tumor revealed advanced proliferation of microvessels. The vessels of glomeruloid type exhibited multilayered endothelial proliferation and marked mitotic activity. MIB1 labelling index was generally low; however, in areas exhibiting microvascular proliferation its expression was significantly increased up to 20%. This report demonstrates the unique case of RGNT with conspicuous microvascular proliferation of glomeruloid type and extensive endothelial proliferation. As there is still limited clinical experience with RGNT, further studies are necessary to evaluate the biology of this type of tumor.

Aggressive osteoblastoma of the sphenoid bone.

For osteoblastoma, with its predilection for the spinal column and appendicular skeleton, the skull is an unusual site, and paranasal sinus involvement is very rare. Herein, we report on a case in which the disease was located within the sphenoid bone. To the best of our knowledge, this is the 4th reported case of osteoblastoma with a sphenoid origin (1). We report an osteoblastoma of the sphenoid sinus in a 12-year-old girl who presented with exophthalmos. Computed tomography (CT) demonstrated an expansile lesion of the sphenoid which caused the orbital contents to be compressed and deviated to the right. In the magnetic resonance imaging scan, the lesion was found to invade the cranial base in the frontal and temporal region, approximating to the cavernous sinus and internal carotid artery on the right. Bilateral fronto-orbital craniotomy was performed. Histologically, the lesion was composed of proliferating osteoblasts along with vascular stroma. The tumor was described as an aggressive osteoblastoma. In the follow-up CT four months later, a pathological mass was observed in the area of the nasal septum, and a signal void was present on all sequences in the densely sclerotic areas. A second resection was performed. The patient has been disease-free for 61 months. Herein, we present the diagnosis and management of this unusual lesion. The histopathology and the imaging characteristics are shown.

[Skull base surgery techniques in the treatment of pituitary adenomas]. / Zastosowanie technik chirurgii podstawy czaszki w leczeniu gruczolaków przysadki.

The giant pituitary adenoma surgery remains a real challenge to any neurosurgeon. Despite an extensive development of transsphenoidal techniques, open craniotomy procedures still are required in 5-10% of all cases with pituitary adenoma. The skull base surgery techniques not only allow to minimize the surgery-related trauma of the brain, but also improve the access to the operating field. In the years 1998-2001 the authors operated on the total of 395 pituitary adenoma patients, mostly using the transsphenoidal approach (320 cases), with skull base surgery techniques applied in 75 cases (i.e. in 19% of all patients)--in 67 patients the transbasal-subfrontal approach was applied, and in 2 cases--lateral rhinotomy. There were two indications to the transbasal-subfrontal approach: a large size of the tumor causing visual disturbances, and extension of the adenoma to adherent anatomical spaces. In this group of patients the total removal of the tumour was achieved in 88% of cases. In the remaining patients remnants of the tumor were left in the cavernous sinuses. The skull base surgery techniques are most useful in the treatment of selected patients with pituitary adenoma.