Visualisation of the extent of damage in a rat spinal cord injury model using MR microsopy of the water diffusion tensor

Magnetic Resonance Diffusion Tensor Imaging (DTI) of the control and traumatic injured spinal cord of a rat in vitro is reported. Experiments were performed on excised spinal cords from 10 Wistar rats, using a home-built 6.4 T MR microscope. MRI and histopathological results were compared. Presented results show that DTI of the spinal cord, perfused with formalin 10 minutes after the injury, can detect changes in water diffusion in white matter (WM) and in gray matter (GM), in areas extending well beyond the region of direct impact. Histology of neurons of the GM shows changes that can be attributed to ischemia. This is in agreement with the observed decrease of diffusion in the injured regions, which may be attributed to the cytotoxic edema due to ischemia. However, the diffusion changes in highly anisotropic WM seem to be caused by a direct action of mechanical force of impact, which significantly distorts the nerve fibers.     

Silver-Staining Nucleolar Organizer Region Quantification in Pituitary Adenomas

Nucleolar organizer regions (NORs) are segments of DNA, encoding for ribosomal RNA. They are associated with argyrophilic proteins and, thus, they can be localized through silver staining. A correlation has been shown between the number, the size, or the intranuclear localization of AgNORs, and the proliferative activity of cells. The aim of this study was to examine numerous features of AgNORs in pituitary adenomas and to relate them to immunohistochemical typing of tumor. Histologic slides from 32 pituitary tumors and one normal pituitary were silver-stained and analyzed with a computerized system for microscopic image analysis, supported by an AgNORmeter95 program. All the tumors were also immunocyto chemically characterized. We have found that gonadotropinomas, when compared with plurihormonal adenomas, revealed a lower proportion of nuclei with a single AgNOR and a higher percentage of marginal dots. Recurrent adenomas, when compared with primary adenomas, showed a higher proportion of nuclei with three AgNOR dots, a larger total area of dots in the nuclei, and a higher standard deviation of the AgNOR dot area in the nucleus. Adenomas immunopositive for prolactin, when compared with immunonegative ones, showed a larger mean area of the AgNOR dot, a larger area of the biggest dot in the nucleus, and a higher proportion of nuclei within a single dot. These results suggest that the estimated parameters of AgNOR dots differ according to tumor aggressiveness and to the hormone immunopositivity of pituitary adenomas.     

Dopamine, serotonin and noradrenaline changes in the striatum of C57BL mice following myelin oligodendrocyte glycoprotein (MOG) 35-55 and complete Freund adjuvant (CFA) administration.

Many data suggest involvement of inflammation in neurodegeneration. However, the exact mechanisms of this cooperation are poorly understood. We have previously shown that induction of inflammatory reaction, both before and after injury of the striatum, affects regeneration of dopaminergic neurons. In the present research we studied the role of inflammatory reaction in non-injured striatum. We used myelin oligodendrocyte glycoprotein (MOG) 35-55 in complete Freund's adjuvant (CFA) to elicit experimental autoimmune encephalomyelitis (EAE) mice model. As determined by HPLC, striatal dopamine (DA) and serotonin levels in mice treated with either MOG 35-55 in CFA or CFA alone were significantly higher compared to vehicle-treated controls on 13th day after induction. The ratio of homovanilic acid/dopamine (HVA/DA) and 3, 4 dihydroxyphenylacetic acid/dopamine (DOPAC/DA) were significantly lower in the MOG and CFA groups on 13th day, indicating decreased DA metabolism. Noradrenaline (NA) concentration did not differ between groups. Moreover, the striatal mRNA IL-1beta and TNF-alpha levels were elevated during induction phase of EAE in both groups, as determined by RT-PCR. Our data indicate regulatory connection between dopaminergic and immune systems.     

Nuclear translocation of survivin in hepatocellular carcinoma: a key to cancer cell growth?

Survivin is a recently described anti-apoptosis protein and regulator of cell division. Its expression and localization in hepatocellular carcinoma (HCC) and in normal liver tissue has not been fully elucidated. We examined the expression of survivin, Fas, proliferating cell nuclear antigen (PCNA), and apoptosis in 47 specimens of hepatocellular carcinoma (HCC) and surrounding nonmalignant hepatic tissues. To further determine the relationship between survivin expression and cell proliferation and apoptosis, we performed double immunostaining for survivin and PCNA TUNEL staining in the same HCC specimens. Positive immunostaining for survivin was present in 35 of 47 (74%) HCCs. Twenty-two of 35 survivin-positive HCCs (63%) showed punctate nuclear staining in HCC cells, and the remaining 13 showed predominant cytoplasmic staining. In contrast, nonmalignant hepatocytes showed only cytoplasmic staining. HCC cells had significantly higher PCNA-labeling and apoptotic indices compared with the case of nonmalignant hepatic tissue (P<0.001). Furthermore, nucleus-positive HCC specimens for survivin showed the highest PCNA labeling index. The nuclear localization of survivin in HCC cells correlated with tumor cell de-differentiation with the exception of the HepG2 cell line. Survivin expression was inversely associated with apoptosis and was strongly associated with Fas expression (P=0.01). All 4 HCC cell lines examined showed survivin expression and punctate nuclear localization. Our results indicate that survivin is localized to the cytoplasm in quiescent nonmalignant liver cells to suppress apoptosis and translocates into the nucleus in HCC cells. In conclusion, translocation of survivin from the cytoplasm to the nucleus may constitute an important regulatory mechanism for cell proliferation and differentiation in HCC.     

Polymerisationsauslösung mit substituierten ethanen, 2. Trennung der Oligomeren aus Methylmethacrylat und 1,1,2,2-Tetraphenyl-1,2-diphenoxyethan

The telechelics 1 from methyl methacrylate and 1,1,2,2-tetraphenyl-1,2-diphenoxyethane, can be separated by adsorption chromatography. The structure of the dimers and trimers was identified by ¹H NMR-spectroscopy. The free radical oligomerization is a process in which the syndiotactic structure is favoured above the isotactic one.     

Synthesis and properties of well-defined multiblock copolymers: poly(4,4′-isopropylidenediphenyl carbonate)-block-polystyrene

Well-defined poly(4,4′-isopropylidenediphenyl carbonate)-block-polystyrene multiblock copolymers, PC-b-PS, were prepared by condensation of PC prepolymers having chloroformyl end-groups with PS prepolymers having hydroxyl end-groups. Both prepolymers had narrow molecular weight distribution (PC prepolymer: M?_w/M?_n ≤ 1,31, PS prepolymer: M?_w/M?_n ≤ 1,03). The course of the polycondensation reaction depends on the molecular weight of the prepolymers used as substrates. After fractionation, the obtained multiblock copolymers are homogeneous in chemical composition and have a narrow molecular weight distribution. The mechanical properties of the copolymers depend on the weight fraction of the PS blocks. All copolymers exhibit two glass transition temperatures, close to those of the parent homopolymers.     

Formation of the intermediate cyclic six-membered oxonium ion in the cationic polymerization of β-propiolactone initiated with CH3CO⊕SbF

Analysis of the ¹H NMR spectra of \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm CH}_{\rm 3} \mathop {\rm C}\limits^ \oplus {\rm OSbF}_{\rm 6}^ \ominus $\end{document} /β-propiolactone and of the model systems \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm CH}_{\rm 3} \mathop {\rm C}\limits^ \oplus {\rm OSbF}_{\rm 6}^ \ominus $\end{document}/(CH₃)₂O and \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm CH}_{\rm 3} \mathop {\rm C}\limits^ \oplus {\rm OSbF}_{\rm 6}^ \ominus $\end{document}/CH₃COOCH₃ in liquid SO₂ in the temperature region ?70 to ?20°C revealed that the reaction of the acetylium cation with β-propiolactone leads to the cyclic six-membered oxonium ion 4 , participating as an intermediate in the initial stage of polymerization.     

Influence of exposure mode on vinyl chloride action

Rats were subjected to 4 h continuous or intermittent exposure to vinyl chloride (VC) at different time-weighted average concentrations (15, 50, 150, 500 and 15,000 mg/m³). Hepatic non-protein sulfhydryl content (NPSH) and excretion of thiodiglycolic acid (TdGA) in urine were determined. VC at concentrations from 50 mg/m³ to 15,000 mg/m³ caused a dose-dependent depression of NPSH, but no difference in the magnitude of this depression induced by continuous or intermittent exposure at the same average concentration of VC was noted. At average concentrations of 50 mg/m³ and 150 mg/m³, the urinary excretion of TdGA under continuous exposure did not differ from that under intermittent exposure, whereas at VC concentrations of 500 mg/m³ and 15,000 mg/m³ it was higher following continuous exposure.     

Methylation and Expression of FTO and PLAG1 Genes in Childhood Obesity: Insight into Anthropometric Parameters and Glucose–Lipid Metabolism

The occurrence of childhood obesity is influenced by both genetic and epigenetic factors. FTO (FTO alpha-ketoglutarate dependent dioxygenase) is a gene of well-established connection with adiposity, while a protooncogene PLAG1 (PLAG1 zinc finger) has been only recently linked to this condition. We performed a cross-sectional study on a cohort of 16 obese (aged 6.6–17.7) and 10 healthy (aged 11.4–16.9) children. The aim was to evaluate the relationship between methylation and expression of the aforementioned genes and the presence of obesity as well as alterations in anthropometric measurements (including waist circumference (WC), body fat (BF_kg) and body fat percent (BF_%)), metabolic parameters (lipid profile, blood glucose and insulin levels, presence of insulin resistance) and blood pressure. Expression and methylation were measured in peripheral blood mononuclear cells using a microarray technique and a method based on restriction enzymes, respectively. Multiple regression models were constructed to adjust for the possible influence of age and sex on the investigated associations. We showed significantly increased expression of the FTO gene in obese children and in patients with documented insulin resistance. Higher FTO expression was also associated with an increase in WC, BF_kg, and BF_% as well as higher fasting concentration of free fatty acids (FFA). FTO methylation correlated positively with WC and BF_kg. Increase in PLAG1 expression was associated with higher BF%. Our results indicate that the FTO gene is likely to play an important role in the development of childhood adiposity together with coexisting impairment of glucose-lipid metabolism.