Chiari I malformation in adults: epileptiform events and schizophrenia-like psychosis

We would like to report on a very interesting clinical case of recurrent psychotic events caused with Chiari I malformation in adults. The mediosagital reconstruction of MR image of the brain and cranio-cervical region is the most important diagnostic approach in finding the cause of epileptiform events, neurological signs and psychotic illness caused by Chiari malformation.     

Strain difference in susceptibility to experimental autoimmune encephalomyelitis between Albino Oxford and Dark Agouti rats correlates with disparity in production of IL-17, but not nitric oxide

Albino Oxford (AO) rats, unlike Dark Agouti (DA) rats are resistant to the induction of experimental autoimmune encephalomyelitis (EAE). The reason for the resistance could be some restraining mechanism preventing auto-aggressive cell activation at the level of draining lymph nodes (DLN) during the induction phase of the disease. Such a mechanism could be anti-proliferative action of nitric oxide (NO), which has already been shown of importance for the resistance of several rat strains to the induction of the disease. Importantly, number of AO DLN cells (DLNC) is markedly lower and with lower proliferative response to myelin basic protein (MBP) ex vivo in comparison to DA DLNC in the inductive phase of EAE, thus implying that in AO rats DLNC do not proliferate as extensively as in DA rats. We show that AO rats do not produce larger quantities of NO than DA rats after immunization. Further, DLNC of immunized AO rats have significantly lower mRNA expression and synthesis of interferon (IFN)-gamma and interleukin (IL)-17 compared to DLNC of DA rats. Collectively, these results suggest that there is a substantial difference between EAE-resistant AO rats and EAE-prone DA rats in the initiation of autoimmune response. This difference seems to be independent of anti-proliferative actions of NO, but correlates with impaired IL-17 production in AO rats.     

Antioxidant Enzymes Show Adaptation to Oxidative Stress in Athletes and Increased Stress in Hemodialysis Patients

The aim of the study is to compare oxidative stress in hemodialysis patients in controls and in rowers. The patients are a model of decreased antioxidant capacity, and the athletes (rowers) are a model of the highest antioxidant capacity due to their chronic adaptation to demanding training. Thirty‐five subjects participated in the study, 9 patients with end‐stage renal disease treated by hemodialysis, 12 healthy young subjects from the normal population, and 14 rowers. The antioxidant enzymes catalase, superoxide dismutase, and glutathione peroxidase, as well as non‐transferrin‐bound iron as a promoter of free radical damage, were determined. Blood analysis was taken in dialysis patients in the morning, before the dialysis procedure. There was significantly higher activity of catalase in dialysis patients (catalase 4.26 ± 0.35 mkat/g Hb) compared to the controls (catalase 2.73 ± 0.38 mkat/g Hb) and rowers (catalase 1.71 ± 0.30 mkat/g Hb). Superoxide dismutase activity was significantly lower (10.42 ± 1.46 µkat/g Hb) than in the controls (11.94 ± 1.18 µkat/g Hb) and rowers (14.09 ± 0.92 µkat/g Hb). There was no significant differences between glutathione peroxidase activities in the three groups. Superoxide dismutase and Se were higher in rowers than in dialysis patients (P < 0.05). The concentrations of both non‐transferrin‐bound iron and ferritin were significantly higher in dialysis patients. Hemodialysis patients might have increased oxidative stress, which is characterized by significantly higher erythrocyte enzyme activity of catalase and lower activity of superoxide dismutase. Top rowers had increased superoxide dismutase and glutathione peroxidase, perhaps because of adaptation during training, which was not the case in dialysis patients and controls.     

Local application of concentrated trombocytes and the level of osseointegration of dental titanium implants: a histomorphometrical analysis

BACKGROUND/AIM: In order to achieve better, and, thus an increased bone-implant interface, growth factors have been used over the past few years. All growth factors considered have fundamental role in the growth and development of cells and tissues. Concentrated trombocytes from platelet-rich plasma (CT-PRP) are fraction of the blood. Thrombocytes contain a number of growth factors namely PDGF, TGF-beta, IGF, VEGF and many others, which contribute to the achievement of the increased bone-implant interface, the increased stability of implants and the faster functional loading of implants. The aim of this study was to establish the effect of CT-PRP on bone-implant interface. METHODS: This experimental study included six dogs in which 24 BCT implants were inserted (4 implants per dog). On the left side of the lower jaw 2 implants were placed with CT-PRP, while on the right side the implants were placed without CT-PRP. The animals were sacrificed after 42, 70, and 98 days. The specimens were examined histomorphometrically, and analyzed 42, 70 and 98 days after the implant insertion. The contacts bone to implant in 16 zones for each analyzed implant were measured according to the established protocol. RESULTS: Results obtained with histomorphometrical analysis imply the increased bone-to-implant contact by use CT-PRP. The difference of the bone-to-implant contacts between these two groups of inserted implants has been particularly pronounced at six weeks after the implant insertion. CONCLUSION: According to the obtained results in the measurement of the level of osseointegration of the inserted implants, it should be advisable to use the CT-PRP method because it provides the higher level of osseointegration.     

BACE1 expression and activity: relevance in Alzheimer's disease

A turning point of research in Alzheimer's disease was undoubtedly the discovery of BACE1, the amyloid-beta precursor protein-cleaving enzyme that initiates the generation of amyloid-beta, the peptide strongly suspected to be responsible for neuronal malfunction and death. Several research groups started a race to identify the best inhibitor of BACE1 activity. On the other hand, basic researchers are evaluating the changes in BACE1 expression and activity with the aim to better understand the pathogenetic process of the disease. Along this second line of research, in the last few years many important results have been reported in various experimental models, as well as in Alzheimer's disease patients. As a consequence, new pathogenetic paradigms have been developed. We have reviewed these reports trying to highlight contrasting viewpoints, data awaiting final confirmation, and promising perspectives.     

Irinotecan toxicity to human blood cells in vitro: relationship between various biomarkers

Toxic effects of the antineoplastic drug irinotecan on human blood cells at concentrations of 9.0 microg/ml and 4.6 microg/ml were evaluated in vitro. Using the alkaline and neutral comet assay significantly increased levels of primary DNA damage in lymphocytes were detected. The induction of apoptosis/necrosis, as determined by a fluorescent assay, was also notably increased. Cytogenetic outcomes of the treatment were assessed by the analysis of structural chromosome aberrations and fluorescence in situ hybridization. A significantly higher incidence of chromatid breaks and complex quadriradials was observed. Painted chromosomes 1, 2 and 4 were equally involved in translocations, but only the chromosome 1 was involved in the formation of quadriradials. Sister chromatid exchange analysis was performed in parallel with the analysis of lymphocyte proliferation kinetics. The higher concentration of irinotecan caused almost seven-time increase, while the lower one caused a five-time increase of the basal sister chromatid exchange frequency, accompanied with significant lowering of the lymphocyte proliferation index. Using the cytokinesis-block micronucleus assay, a dose-dependent increase in micronucleus frequency along with the formation of nuclear buds and nucleoplasmic bridges was noticed. Inhibitory effects of irinotecan on enzyme acetylcholinesterase (AChE) were studied in erythrocytes. An IC(50) value of 5.0 x 10(-7) was established. Irinotecan was found to be strong inhibitor of the acetylcholine hydrolysis and to cause a continuous decrease of catalytic activity of AChE. The results obtained on a single donor may contribute to the understanding of irinotecan toxicity, but further in vitro and in vivo studies are essential in order to clarify remaining issues, especially on possible inter-individual variability in genotoxic responses to the drug.     

Effect of parsley (Petroselinum crispum (Mill.) Nym. ex A.W. Hill, Apiaceae) extracts on some biochemical parameters of oxidative stress in mice treated with CCl(4)

The in vitro and in vivo antioxidant activity of different extracts of leaves and root of parsley (Petroselinum crispum (Mill.) Nym. ex A.W. Hill, Apiaceae) were studied. Free radical scavenging capacity (RSC) was evaluated measuring the scavenging activity on the 2,2-diphenyl-1-picrylhydrazil (DPPH) and OH radicals. Also, the effects on lipid peroxidation (LP) were evaluated. The results obtained showed that all examined extracts act as good scavengers of DPPH and OH radicals and reduce the intensity of LP. The in vivo effects were evaluated on some antioxidant systems (activities of LPx, GSH-Px, Px, CAT and XOD, and GSH content) in the mice liver and blood after treatment with the examined parsley extracts, or in combination with carbon tetrachloride (CCl(4)). On the basis of the results obtained it can be concluded that the examined extracts exhibited a certain protective effect. However, combined treatments with CCl(4) and the examined extracts showed both positive and negative synergism, inducing or suppressing the influence of CCl(4) alone.