Spectral characteristics of the bioelectrical activity of the cerebral cortex upon electric stimulation of subcortical structures

A spectral-correlation analysis of electrical activity of the rabbit cerebral cortex was made with the use of Dnieper computer, after electrical stimulation (100-250 c/s) of the midbrain reticular formation, the thalamic nonspecific formations (midline nuclei) and different nuclei of the posterior part of the hypothalamic area (ventromedial and posterior hypothalamic nuclei and the lateral field). The background spectrograms were characterized by a high variability; their frequencies ranged from 0,5 to 12 c/s. Under the influence of the electrical stimulation of the indicated formations, a well-pronounced, dominating peak appeared in the spectrograms of the cortical EEG, in the band from 4 to 7 c/s, and the similarity of biopotentials in this rhythm increased. The experimental data show that enhancement of spatial synchronization of the cortical biopotentials under conditions of electrical stimulation of the indicated subcortical formations is based on increased rhythmic oscillations within the theta-band and on a greater coherence in this range.     

Lanthanide(III) halides: Thermodynamic properties and their correlation with crystal structure

Temperatures and enthalpies of phase transitions of 17 lanthanide(III) halides determined experimentally are reported. Correlations were made between temperature of fusion of lanthanide(III) halides, on the one hand, and enthalpy of fusion, on the other, versus atomic number of lanthanide. According to this classification, the lanthanide(III) halides split into groups, as also do the corresponding crystal structures. A correlation between the crystal structure of lanthanide(III) halides and their respective entropy of fusion (or entropy of fusion + entropy of solid–solid phase transition) was inferred from the aforementioned features. Fusion in those halides with hexagonal, UCl₃-type and orthorhombic, PuBr₃-type, structures entails an entropy of fusion change (or entropy of fusion + entropy of solid–solid phase transition change) by 50 ± 4 J mol⁻¹ K⁻¹. The homologous entropy change within the group of halides having the rhomboedric, FeCl₃-type, structure, is smaller and equals 40 ± 4 J mol⁻¹ K⁻¹. Halides with monoclinic, AlCl₃-type, crystal structure constitute a third group associated to an even smaller entropy change upon fusion, only 31 ± 4 J mol⁻¹ K⁻¹. The halides with lower entropies of fusion also have a lower S_1300 K − S_298 K indicating either a higher degree of order in the liquid or a higher entropy in the solid at room temperatures.     

miR 31-3p Has the Highest Expression in Cesarean Scar Endometriosis

Micro-RNAs expression can vary between different forms of endometriosis, but data on miRNA expression in cesarean scar endometriosis is lacking. The present study is comprised of 30 patients with endometriosis in the cesarean scar (scar endometriosis, SE), 14 patients with deep infiltrating endometriosis (DIE), 47 patients with endometrioma (ovarian endometrial cyst, OE), and 33 patients with healthy ovarian tissue as the control group (CG). In the initial experiment to identify possible dysregulated miRNAs, the levels of 754 miRNAs in formalin-fixed paraffin-embedded tissue (FFPE) samples from OE, high-grade ovarian cancer, endometrioid ovarian cancer, and CG were measured. We identified seven potentially dysregulated miRNAs: miR-1-3p, miR-31-3p, miR-125b-1-3p, miR-200b-3p, miR-548d, miR-502, and miR-503. We then examined the expression profiles of each of these miRNAs individually in the SE, DIE, OE, and CG FFPE samples using RT-qPCR. miR-31-3p had significantly higher levels of expression and miR-125b-1-3p had significantly lower levels of expression in SE compared to the controls. Overall, the higher expression levels of miR-31-3p and the lower expression levels of miR-125b-1-3p are consistent with the benign nature of SE. Importantly, the results of the present study demonstrate the possibility of using miRNA to monitor the risk of malignant transformation of endometriosis tissue.     

Staurosporine inhibits interferon alpha-induced gene expression in Friend erythroleukemia cells through a PKC independent pathway

Diabetes mellitus is associated with typical patterns of long term vascular complications which vary with the organ involved. The microvascular kidney disease (Olgemoller and Schleicher, 1993) is characterized by thickening of the capillary basement membranes and increased deposition of extracellular matrix components (ECM), while loss of microvessels with subsequent neovascularisation is predominant in the eye and peripheral nerves. On the other hand macrovascular disease is characterized by accelerated atherosclerosis. These complications are dependent on long term hyperglycemia. Specific biochemical pathways linking hyperglycaemia to microvascular changes were proposed: the polyol pathway (Greene et al., 1987), non-enzymatic glycation of proteins (Brownlee et al., 1988), glucose autooxidation and oxidative stress (Hunt et al., 1990), hyperglycemic pseudohypoxia (Williamson et al., 1993) enhanced activation of protein kinase C by de novo-synthesis of diacyl glycerol (Lee et al., 1989; DeRubertis and Craven 1994) and others. These pathways are not mutually exclusive (Larkins and Dunlop, 1992; Pfeiffer and Schatz, 1992). They may be linked to alterations in the synthesis of growth factors particularly since atherosclerosis and angioneogenesis are associated with increased proliferation of endothelial and smooth muscle cells. Increased synthesis of ECM components is stimulated by growth factors like transforming growth factor beta (TGF beta) (Derynck et al., 1984) and insulin-like growth factor I (IGF-I) (Moran et al., 1991). This review will summarize some of the recent evidence for an involvement of growth factors in diabetic vascular complications and will attempt to assign their emergence in the sequence of events leading to vascular complications.     

Synthesis of modified oligodeoxyribonucleotides containing 9-(2'-amino-2'-deoxy-beta-D-arabinofuranosyl)adenine

A method for preparing a modified derivative of 2'-amino-2'-deoxy-arabino-adenosine ready for directed insertion into an oligonucleotide chain during solid-phase synthesis was elaborated. A series of the title oligonucleotides (6-25-mers) containing a 2'-amino-2'-deoxy-arabino-adenosine fragment were prepared. A high reactivity of the 2'-amino group during the acylation with carboxylic acid anhydrides was demonstrated. It was shown that the insertion of the modified fragments into oligonucleotides did not inhibit the formation of the DNA duplex.     

Gangliocytoma--magnetic resonance imaging characteristics

An atypical presentation of a temporal lobe gangliocytoma in an adult female with headaches is reported. Computed tomography showed a hypodense enhancing mass in the right temporal lobe with vasogenic oedema and mass effect. MRI demonstrated a well demarcated mass of low signal on T1W, intermediate signal on PDW, high signal on T2W and homogeneous enhancement on post-gadolinium scan. This case is an addition to the current literature for the characteristic MR features of a ganglion cell tumour.     

A new method of nonradioactive labelling of oligonucleotides and their use as allele-specific probes for detecting mutations causing beta-thalassemia

We have developed simple and efficient methods for synthesis of biotin and horseradish peroxidase (HRP)-labeled oligonucleotides. Biotinylated oligonucleotides were obtained in quantitative yields, and oligonucleotide conjugates with HRP in 60-80% yields. Allele-specific oligonucleotide probes for the diagnostics of IVS 1-110 mutation in the beta-globin gene causing beta-thalassemia were thus obtained. Temperature conditions for the non-radioactive ASO hybridization with the amplified segment of the human beta-globin gene and wash conditions were selected. HRP-labelled probes were used in hybridization without preliminary separation after synthesis. To decrease nonspecific enzyme binding we have elaborated special conditions for membrane blocking. Detection of the biotinylated probe was carried out with the help of a streptavidin--HRP conjugate. O-Dianisidine was used as a chromogenic substrate. We have demonstrated the usefulness of this method in the analysis of amplified samples of DNA obtained from blood of patients homozygous in the mutant gene, and heterozygous carriers.     

Reversal of advanced liver fibrosis in rabbits with Schistosomiasis japonica

Advanced liver fibrosis is generally considered to be irreversible. We studied the reversibility of marked liver fibrosis in rabbits infected with Schistosoma japonicum. We determined liver collagen content, collagen biosynthesis, and collagenase activity using serial biopsy specimens obtained 20, 40, and 60 weeks after infection. Reversibility of this process was investigated in rabbits cured of infection at 21 weeks; control rabbits not cured of infection were also studied. At 20 weeks, liver collagen content was 16-fold greater than normal, with accumulation of collagen types I, III, and V. Synthesis of collagen within fibrotic liver slices was 10-fold greater than normal. Liver collagenolytic activity for a type I substrate was 19-fold greater than normal. After parasitologic cure, a striking morphologic reversal of fibrosis occurred during the subsequent 40 weeks, with the return of liver collagen content to three-fold greater than normal and a 75% decrease in synthetic rates compared with those at 20 weeks (P < 0.01). Collagenolytic activity remained elevated to the same degree noted at 20 weeks. A similar but lesser resolution of fibrosis also occurred in untreated control rabbits, coincident with a spontaneous decrease in new egg deposition known to occur in this model system. We conclude that advanced liver fibrosis in S. japonicum-infected rabbits is slowly reversible after cure or senescence of the infection. A possible mechanism for this reversal is persistently increased collagenolysis as collagen synthesis diminishes.     

Low doses of eicosapentaenoic acid, docosahexaenoic acid, and hypolipidemic eicosapentaenoic acid derivatives have no effect on lipid peroxidation in plasma

It was of interest to investigate the influence of both high doses of eicosapentaenoic acid (EPA) and low doses of 2- or 3-methylated EPA on the antioxidant status, as they all cause hypolipidemia, but the dose required is quite different. We fed low doses (250 mg/d/kg body wt) of different EPA derivatives or high doses (1500 mg/d/kg body wt) of EPA and DHA to rats for 5 and 7 d, respectively. The most potent hypolipidemic EPA derivative, 2,2-dimethyl-EPA, did not change the malondialdehyde content in liver or plasma. Plasma vitamin E decreased only after supplementation of those EPA derivatives that caused the greatest increase in the fatty acyl-CoA oxidase activity. Fatty acyl-CoA oxidase activity increased after administration of both EPA and DHA at high doses. High doses of EPA and DHA decreased plasma vitamin E content, whereas only DHA elevated lipid peroxidation. In liver, however, both EPA and DHA increased lipid peroxidation, but the hepatic level of vitamin E was unchanged. The glutathione-requiring enzymes and the glutathione level were unaffected, and no significant changes in the activities of xanthine oxidase and superoxide dismutase were observed in either low- or high-dose experiments. In conclusion, increased peroxisomal beta-oxidation in combination with high amounts of polyunsaturated fatty acids caused elevated lipid peroxidation. At low doses of polyunsaturated fatty acids, lipid peroxidation was unchanged, in spite of increased peroxisomal beta-oxidation, indicating that polyunsaturation is the most important factor for lipid peroxidation.