Co-overexpression of bcl-2 and c-myc in uterine cervix carcinomas and premalignant lesions

To establish the role of co-overexpression of bcl-2 and c-myc protooncogenes in uterine cervix carcinogenesis, we examined 138 tissue samples of low grade cervical squamous intraepithelial lesions (SIL), high grade SIL, portio vaginalis uteri (PVU) carcinoma in situ and PVU carcinoma invasive, stage IA-IIA (study group) and 36 samples without SIL or malignancy (control group). The expression of bcl-2 and c-myc was detected immunohistochemically using a monoclonal antibody. Fisher’s exact test (P<0.05) was used to assess statistical significance. Overexpression of bcl-2 was found to increase in direct relation to the grade of the cervical lesions. High sensitivity was of great diagnostic significance for the detection of these types of changes in the uterine cervix. On the basis of high predictive values it can be said that in patients with bcl-2 overexpression there is a great possibility that they have premalignant or malignant changes in the uterine cervix. Co-overexpression of bcl-2 and c-myc oncogenes was found only in patients with PVU invasive carcinoma (6/26-23.0%). Statistically significant difference was not found in the frequency of co-overexpression in patients with PVU invasive carcinoma in relation to the control group (Fisher’s test; P=0.064). The method's sensitivity of determining these oncogenes with the aim of detecting PVU invasive carcinoma was 23%, while specificity was 72.2%. On the basis of high predictive values (100%), speaking in statistical terms, it can be concluded that all patients with co-overexpression of bcl-2 and c-myc oncogenes will have PVU invasive carcinoma. We confirmed in our research that co-overexpression of bcl-2 and c-myc oncogenes was increased only in PVU invasive carcinoma. However, a more extensive series of samples and additional tests are required to establish the prognostic significance of bcl-2 and c-myc co-overexpression in cervical carcinogenesis.     

Somatostatin modulates T cells development in adult rat thymus

It is well known that somatostatin modulates thymic functions, such as binding to receptors. In order to elucidate the influence of somatostatin on the thymus architecture and the T cells maturation, young adult male rats were treated with somatostatin-28. The results showed that somatostatin-28 decreased thymus weight and cellularity, probably due to alterations in the thymic morphometric parameters. Our results also demonstrated that SRIH treatment reduces number of cells with undetectable alphabetaTCR and cells with low expression of alphabetaTCR, while the number of TCRalphabeta(hi) cells remains approximately the same as the values obtained from the control rats. Besides, in the least mature thymocytes (DNTCR TCRalphabeta(-)) and among the most mature the SPCD4 TCRalphabeta(hi) subset remained unaltered, while SPCD8 TCRalphabeta(hi) decreased. At last, it should be noted that SRIH treatment increases DN thymocytes subsets expressing TCRalphabeta(low/hi) (TCRalphabeta(+)). These results suggest that somatostatin-28 induces reshaping of T cells maturation and, at least partly, contributes to thymic weight loss, through the modulation of the complex neuroendocrine-immune network.     

Isoaspartyl Formation in Creatine Kinase B Is Associated with Loss of Enzymatic Activity; Implications for the Linkage of Isoaspartate Accumulation and Neurological Dysfunction in the PIMT Knockout Mouse

Isoaspartate (isoAsp) formation is a common type of spontaneous protein damage that is normally kept in check by the repair enzyme protein-L-isoaspartyl methyltransferase (PIMT). PIMT-KO (knockout) mice exhibit a pronounced neuropathology highlighted by death from an epileptic seizure at 30 to 60 days after birth. The mechanisms by which isoaspartyl damage disrupts normal brain function are incompletely understood. Proteomic analysis of the PIMT-KO mouse brain has shown that a number of key neuronal proteins accumulate high levels of isoAsp, but the extent to which their cellular functions is altered has yet to be determined. One of the major neuronal targets of PIMT is creatine kinase B (CKB), a well-characterized enzyme whose activity is relatively easy to assay. We show here that (1) the specific activity of CKB is significantly reduced in the brains of PIMT-deficient mice, (2) that in vitro aging of recombinant CKB results in significant accumulation of isoAsp sites with concomitant loss of enzymatic activity, and (3) that incubation of in vitro aged CKB with PIMT and its methyl donor S-adenosyl-L-methionine substantially repairs the aged CKB with regard to both its isoAsp content and its enzymatic activity. These results, combined with similarity in phenotypes of PIMT-KO and CKB-KO mice, suggests that loss of normal CKB structure and function contributes to the mechanisms by which isoAsp accumulation leads to CNS dysfunction in the PIMT-KO mouse.     

Middle Triassic carbonate-platform break-up and formation of small-scale half-grabens (Julian and Kamnik–Savinja Alps, Slovenia)

In the Julian Alps (Mt. Prisojnik, NW Slovenia) and in the Kamnik–Savinja Alps (Mt. Kri?evnik, N Slovenia), both of which form part of the eastern Southern Alps, several meters of Upper Anisian pelagic red nodular, radiolarian-rich limestone (Loibl Formation) were deposited on the drowned platform carbonates of the Contrin Formation. The time of the platform drowning is dated with radiolarians and conodonts to the Illyrian, more precisely to the upper part of the Paraceratites trinodosus Ammonoid Zone. The red limestone is overlain by pyroclastics and volcanics (rhyolites) or carbonate (mega)breccia (Uggowitz Formation). The following unit consists of thin-bedded limestone, grainstone and subordinate marl (Buchenstein Formation) deposited during the final filling of the basin from the adjacent prograding carbonate platform (Schlern Formation) in the Ladinian. Map-scale geometry, neptunian dykes, the onset of volcanism, the presence of (mega)breccia and related paleo-escarpments, the lateral variations in thickness and the wedge-shaped geometry of the lithological units provide evidence of syn-sedimentary block faulting and the formation of small-scale, relatively shallow half-grabens within the previously uniform Slovenian Carbonate Platform. This analysis indicates a clear tectonic control over the development of the Middle Triassic stratigraphy. The described extensional event is well correlated and genetically connected with the syn-rift formation of the neighboring Slovenian Basin and other Southern Alpine basins that formed in connection with the opening of the Meliata-Maliac branch of the Neotethys Ocean.     

Biologically active fibers based on chitosan-coated lyocell fibers

The possibilities of obtaining biologically active cellulose–chitosan fibers were examined. An effective two-stage method was developed. The first stage involves the formation of dialdehyde cellulose by the potassium periodate oxidation of lyocell fibers, which is able to form Schiff’s base with chitosan. In the second stage, chitosan-coated lyocell fibers were prepared by subsequent treatment of oxidized lyocell fibers with a solution of chitosan in aqueous acetic acid. The impact of this two-stage protocol on the chemical and physical properties of lyocell fibers was evaluated by determining carbonyl group content, fineness and tensile strength of fibers, as well as chitosan content in the composite cellulose–chitosan fibers. Antibacterial activity of the chitosan-coated lyocell fibers against different pathogenens: Staphylococcus aureus and Escherichia coli, was confirmed in vitro experiments.     

Characteristics of the tonic stretch reflex in spastic spinal cord and head-injured patients

Spasticity is a known sequelae of spinal cord injury and head injury. We sought to examine whether there were any significant differences in the characteristics or underlying mechanisms of spasticity in these two groups in the chronic period which may be related to the level of injury of the neuraxis. The response to vibration applied to the muscle, or the tonic vibratory reflex, has been shown to be related to the degree of spasticity, and was therefore studied along with phasic reflexes and passive movements. These studies were carried out on cooperative, stabilized patients who were otherwise healthy, 5 with head injuries, and 5 with spinal cord injuries. The patients were examined in a supine position while surface EMG recordings were made of quadriceps and triceps surae muscles bilaterally. Tendon jerk responses, passive and volitional movements, and responses to a powerful vibratory stimulator were measured. In both head injury and spinal cord injury patient groups, a large EMG response was elicited by passive maneuvers, and tendon jerks were exaggerated. The tonic vibratory response, previously shown to be dependent upon brain influence, was present in both groups. These observations suggest that similar suprasegmental mechanisms may be responsible for hypertonia in both head-injured and spinal cord-injured patients.     

Frequency-dependent selection of alternative spinal pathways with common periodic sensory input

Electrical stimulation of the lumbar cord at distinct frequency ranges has been shown to evoke either rhythmical, step-like movements (25–50 Hz) or a sustained extension (5–15 Hz) of the paralysed lower limbs in complete spinal cord injured subjects. Frequency-dependent activation of previously silent spinal pathways was suggested to contribute to the differential responsiveness to distinct neuronal codes and the modifications in the electromyographic recordings during the actual implementation of the evoked motor tasks. In the present study we examine this suggestion by means of a simplified biology-based neuronal network. Involving two basic mechanisms, temporal summation of synaptic input and presynaptic inhibition, the model exhibits several patterns of mono- and/or oligo-synaptic motor output in response to different interstimulus intervals. It thus reproduces fundamental input–output features of the lumbar cord isolated from the brain. The results confirm frequency-dependent spinal pathway selection as a simple mechanism which enables the cord to respond to distinct neuronal codes with different motor behaviours and to control the actual performance of the latter.     

The adhesion receptor CD-31 can be primed to rapidly adjust the neutrophil cytoskeleton

The adhesion receptor CD-31 is expressed on neutrophils and endothelial cells and participates in transendothelial migration of neutrophils. Although necessary, information on CD-31-induced signaling and its influence on the shape-forming actin network is scarce. Here, we found that antibody engagement of CD-31 on suspended neutrophils triggered a prompt intracellular Ca(2+) signal, providing the cells had been primed with a chemotactic factor. Inhibition of Src-tyrosine kinases blocked this Ca(2+) signal, but not a fMet-Leu-Phe-induced Ca(2+) signal. Despite the ability of fMet-Leu-Phe to activate Src-tyrosine kinases, it did not per se induce tyrosine phosphorylation of CD-31. However, fMet-Leu-Phe did enable such a phosphorylation following an antibody-induced engagement of CD-31. This clustering also triggered a Ca(2+)-dependent depolymerization of actin and, surprisingly enough, a simultaneous polymerization. The ability of CD-31 to signal dynamic alterations in the cytoskeleton, particularly the Ca(2+)-induced actin depolymerization, further explains how neutrophils can squeeze themselves out between adjacent endothelial cells.     

Superoxide dismutase and catalase activities in purified Frankia vesicles

Superoxide dismutase (EC 1.15.1.1.) and catalase (EC 1.11.1.6.) activities of Frankia cells grown in the presence of ammonium were very high in comparison with those of other prokaryaotes and particularly Rhizobium . Furthermore, these activities were significantly enhanced under nitrogen-fixing conditions where vesicles were produced. By using a single-step sucrose gradient, Frankia vesicles were isolated and appeared intact and free of hyphal contamination. The contents of superoxide dismutase and catalase in the purified vesicles were similar to those in preparations containing both vesicles and hyphae. These results suggest an important role of superoxide dismutase and catalase in the protection of the overall nitrogen-fixation process against O₂ in Frankia vesicles. Beside the protective role played by the thick walls of the vesicles, the presence of specialized enzymes is emphasized.