Herpes simplex encephalomyelitis (HSE) is a rare disease with a high mortality rate. Correct diagnosis is established on the basis of the combination of the clinical and investigative features. Unfortunately, precise diagnosis remains difficult due to several clinical similarities and false negative or inconclusive results of diagnostic tests. Here, we present two cases of HSE together with the morphological and ultrastructural picture. The first case was a 45-year-old man with acute symptoms of encephalitis, and the other one was a 28-year-old woman presenting subacute encephalomyelitis. Both cases had negative serologic and molecular results for Herpes simplex in the blood and cerebrospinal fluid. Brain and spinal cord samples taken from both cases were stained typically with histological and immunohistochemical methods and small tissue fragments were examined with the transmission electron microscope (TEM). Microscopic examination confirmed viral encephalomyelitis in both cases. An electron micrograph showed typical intranuclear viral particles inside of damaged neurons, which together with topography of brain and spinal cord changes suggest HHV-1/HHV-2 in the first case and/or HHV-3 in the other case. Thus, morphological and ultrastructural examinations may be a useful tool to set up correct diagnosis and help to determine the pathogenic factor in patients suspected of viral encephalomyelitis. Meningiomas comprises of awide variety of histological entities with heterogeneous biological behaviour and prognosis. The plethora of genetic data are yet to produce relevant biomarkers for routine use. In contrast, epigenetic alterations are less elucidated. The expression of the key molecules involved in the two principal epigenetic systems, i.e. DNA methylation (DNA methyltransferases [DNMT-1, -3A and -3B]) and histone modification (Enhancer of Zeste homolog-2 [EZH2] and trimethyl histone-3 [H3K27me3]) were assessed in 149 cases of meningiomas (grade I- 102, grade II - 47) by immunohistochemistry. Immunopositivity for EZH2 (38.3% vs. 6.0%) and negativity for H3K27me3 (10.6% vs. 1.0%) were significantly more common in grade II tumours. Both were associated with significantly higher proliferative activity. The majority of the cases of both grades showed expression of all three DNMTs. However, high expression of DNMT-1 was significantly more common in grade II tumours (87.8% vs. 66.2%). Expression of EZH2 and loss of H3K27me3 were associated with significantly shorter progression-free survival (hazard ratio [HR] = 4.07 and 0.24, respectively). The key epigenetic regulators play important roles in the pathobiology of meningiomas. EZH2 positivity and H3K27me3 negativity are associated with aggressive tumour-biology and poor prognosis. Both these markers can easily be assessed by immunohistochemistry and can be incorporated in routine practice. The key epigenetic regulators play important roles in the pathobiology of meningiomas. EZH2 positivity and H3K27me3 negativity are associated with aggressive tumour-biology and poor prognosis. Both these markers can easily be assessed by immunohistochemistry and can be incorporated in routine practice.Nowadays molecular investigations have a significant impact on the understanding of primary brain tumour biology,as well as on their classification and progress in the treatment modalities. Among novel type of biomarkers with potential therapeutic value, microRNAs (miRNAs) are considered in some cases. miRNAs are small molecules regu-lating gene expression, including genes encoding key proteins involved in signalling pathways responsible for growth and cell survival during tumour formation. Incorrectly hyperactivated pathways implicated in brain tumour development are inter alia the PI3K/AKT/mTOR and RAS/MAPK/ERK cascades associated with worse prognosis and decreased patient survival. This work presents relationships between changes in the expression of individual miRNAs and the genes involved in the regulation of PI3K/AKT/mTOR and RAS/MAPK/ERK signalling pathways in primary brain tumours. Herein we present the preliminary results of miR-17-5p and miR-20a (key representatives of the miR-17-92 oncogenic cluster) expression analysis and their connection with signalling pathway activation in two of the most frequent paediatric tumours medulloblastoma and ependymoma. https://www.selleckchem.com/products/vx-661.html Our study was performed using the microarray and qPCR techniques and showed PI3K/AKT/mTOR and RAS/MAPK/ERK among the forefront of the list of pathways with the largest number of genes involved in their activation compared to the control. Predicted target analysis indicated the agents from miR-17-92 cluster within miRNAs regulating activity of PI3K/AKT/mTOR and RAS/MAPK/ERK deregulated genes. The expression level of key representatives of the oncogenic cluster, miR-17-5p, and miR-20a, increased with the WHO grade of the analysed cases; the highest levels were found in medulloblastomas.Lipopolysaccharide (LPS) is a potent immunogen when administered locally and/or systemically. The peripheral immunization with LPS could contribute to the progression of neurological diseases because a strong link between neuroinflammation and dopaminergic degeneration has been found. The switch between the survival and neuronal death in substantia nigra could be related to M1 (neurotoxic) and M2 (neuroprotective) microglia phenotypes. In this review, we present the current findings about microglia roles, biomarkers, and natural or synthetic immune modulators determined in the LPS-based murine model.A hypothesis is proposed to explain the pathogenesis of neurodegenerative disease and the diversity of its phenotypes. The hypothesis is based on seven main propositions 1) neurodegenerative disease is associated with multiple risk factors, 2) age is the most important of the risk factors, 3) aging differentially affects neuroanatomical pathways, 4) degeneration of these pathways results in the formation of pathogenic proteins, 5) pathogenic proteins spread along anatomical pathways, 6) the phenotypes of familial and sporadic forms of disease are similar and 7) neurodegenerative disease is characterised by heterogeneity, overlapping phenotypes, and multiple pathology. It is hypothesised that most cases of neurodegenerative disease are multifactorial in which interactions between external environmental and internal genetic risk factors act cumulatively over a lifetime to determine the 'allostatic load' of an individual. The allostatic load determines the rate of neural aging and results in the differential breakdown of neuro-anatomical pathways influenced by their relative use or disuse during life.