The fate of the arachnoid villi in humans

Villi arachnoidales undergoes in the course of life changes in relation to the skull bones and sinuses. Our aim was to determine the relations of the villi arachnoidales to the skull bone and/or sinuses from the neonatal period to adults. The investigations were performed on collection of 50 disarticulated macerated skull bones from the new-born to 30 years of age and on 20 skulls from individuals in the life period from 30 to 80 years of age. Villi arachnoidales produced imprints on the skull bones in the shape of holes and/or furrows corresponding to different shape of the villi arachnoidales. These imprints appeared very early in the period when the bony sprouts of the large skull bones received a thin covering of compact bone, the future lamina vitrea. At that time villi arachnoidales had no connection with the dural sinuses but with the diploe and with the diploic veins. By agglomeration of the villi in larger and large formations, granula meningea, Pacchionian granulations, the contact to sinuses was realized by means of short channels. The structural changes of villi arachnoidales may produce thrombophlebitis and hydrocephalus externus, especially in children. The fate and the relations of the villi arachnoidales are therefore of great importance for neurologist, neurosurgeon and otorhinolaryngologist.     

Construction of Saccharomyces cerevisiae strain FAV20 useful in detection of immunosuppressants produced by soil actinomycetes

The screening of microbial natural products continues to represent an important route to the discovery of novel chemicals for development of new therapeutic agents. The aim of this work was to develop an efficient method for the detection of immunosuppressive compounds produced by soil actinomycetes. Mutant strain of Saccharomyces cerevisiae, named FAV20, sensitive to FK506 was constructed by disrupting VMA22 gene using the selectable marker kanMX4 which allowed detection of integration events. Actinomycetes were isolated from different soil samples and in a newly developed test with S. cerevisiae FAV20, six strains have been identified that produce bioactive compounds with the same mechanism of action as FK506. S. cerevisiae FAV20 can be easily used as a test strain in drug screening programs based on inhibition of the calcineurin phosphatase dependent signaling pathway in the cell.     

5-Aryl-4-(5-substituted-2,4-dihydroxyphenyl)-1,2,3-thiadiazoles as inhibitors of Hsp90 chaperone

A series of 5-aryl-4-(5-substituted-2,4-dihydroxyphenyl)-1,2,3-thiadiazoles were synthesized and their binding to several constructs of human Hsp90 chaperone measured by isothermal titration calorimetry (ITC). The most potent compound bound Hsp90 with the dissociation constant of about 5 nM.     

Glatiramer Acetate Increases Phagocytic Activity of Human Monocytes In Vitro and in Multiple Sclerosis Patients

Beside its effects on T cells, a direct influence on cells of the myelo-monocytic lineage by GA becomes evident. Recently, we demonstrated that GA drives microglia to adopt properties of type II antigen presenting cells (APC) and increases their phagocytic activity. In the present work, we focused on human blood monocytes in order to examine whether GA may increase phagocytic activity in vivo and to evaluate the molecular mechanisms explaining this new discovered mode of action. Peripheral blood mononuclear cells (PBMC) were obtained using a Biocoll-Isopaque gradient and monocytes were subsequently isolated by using CD14 MicroBeads. Phagocytic activity was determined by flow cytometric measurement of the ingestion of fluorescent beads. Flow cytometry was also used to assess monocytic differentiation and expression of phagocytic receptors. Monocytes of GA treated MS patients exhibited a significantly higher phagocytic activity than those of healthy controls or non-treated MS patients. In vitro, a significant phagocytic response was already detectable after 1 h of GA treatment at the concentrations of 62.5 and 125 µg/ml. A significant increase at all concentrations of GA was observed after 3 h and 24 h, respectively. Only monocytes co-expressing CD16, particularly CD14⁺⁺CD16⁺ cells, were observed to phagocytose. Treatment of monocytes with IL-10 and supernatants from GA-treated monocytes did not alter phagocytosis. We observed a decrease in CD11c expression by GA while no changes were found in the expression of CD11b, CD36, CD51/61, CD91, TIM-3, and CD206. In our blocking assays, treatment with anti-CD14, anti-CD16, anti-TIM3, anti-CD210, and particularly anti-CD36 antibodies led to a decrease in phagocytosis. Our results demonstrate a new mechanism of action of GA treatment that augments phagocytic activity of human monocytes in vivo and in vitro. This activity seems to arise from the CD14⁺⁺CD16⁺ monocyte subset.     

Effects of Radiofrequency Catheter Ablation of Atrial Fibrillation on Soluble P-Selectin,Von Willebrand Factor and IL-6 in the Peripheral and Cardiac Circulation

Background

Catheter ablation (CA) of atrial fibrillation (AF) is associated with inflammatory response, endothelial damage and with increased risk of thrombosis. However, whether these processes differ in peripheral and cardiac circulation is unknown.

Methods

Plasma markers (von Willebrand factor (vWf), soluble P-selectin (sPsel) and interleukin-6 (IL-6)) were measured by ELISA at three time points in 80 patients (62±10 years, 63% males, 41% paroxysmal AF) undergoing CA. These were at baseline – from femoral vein (FV) and left atrium (LA) before ablation; directly after ablation – from the pulmonary vein (PV), LA and FV; and 24 hours after procedure – from a cubital vein (CV).

Results

The levels of vWF and IL6 – but not sP-sel – increased significantly 24h after procedure (p<0.001). Baseline vWF was significantly associated with persistent AF (Beta = .303, p = 0.006 and Beta = .300, p = 0.006 for peripheral and cardiac levels, respectively), while persistent AF (Beta = .250, p = 0.031) and LAA flow pattern (Beta = .386, p<0.001) remained associated with vWF in cardiac blood after ablation. Advanced age was significantly associated with IL6 levels at baseline and after ablation in peripheral and cardiac blood. There were no clinical, procedural or anti-coagulation characteristics associated with sP-sel levels in cardiac blood, while peripheral sP-sel levels were associated with hypertension before (Beta = −.307, p = 0.007) and with persistent AF after ablation (Beta = −.262, p = 0.020).

Conclusions

vWF levels are higher in persistent AF and are associated with LAA rheological pattern after AF ablation. Increase of peripheral vWF and IL6 levels after procedure supports current AF ablation management with careful control of post-procedural anticoagulation to avoid ablation-related thromboembolism.     

The role of rat Crry, a complement regulatory protein, in proliferation of thymocytes

In our previous work we showed that 3F10 monoclonal antibody (mAb), which recognizes the rat complement receptor 1-related/gene protein y (Crry), induces homotipic aggregation of thymocytes. In this work we studied the effect of 3F10 mAb on proliferation of rat thymocytes stimulated with concanavalin A (ConA) or by cross-linking the T cell receptor (TCR) by anti-alphabetaTCR mAb (R73), in vitro, and the mechanisms involved in the process. Our results show that 3F10 mAb stimulates proliferation of total thymocytes triggered by suboptimal concentrations of ConA or TCR cross-linking, in a dose-dependent manner. Maximal stimulation was observed using 10 microg/ml and 20 microg/ml of 3F10 mAb, respectively. The 3F10-induced stimulation of thymocytes proliferation in the presence of ConA, that was followed by increased production of interleukin-2 (IL-2), up-regulation of the expression of IL-2 receptor alpha (IL-2Ralpha) and was inhibited by anti-CD11a and anti-CD18 mAbs. Purified thymocytes did not respond by proliferation to 3F10 mAb, either alone or in combination with R73 mAb or ConA. Proliferation of these cells was achieved only in the presence of OX-6+ antigen-presenting cells (APC) and additional signals transmitted by TCR or ConA. These results suggest that Crry is involved in the LFA-1 dependent proliferation of thymocytes, a phenomenon that has not been recognized so far.     

Saccharomyces cerevisiae nucleolar protein Nop7p is necessary for biogenesis of 60S ribosomal subunits

To identify new gene products that participate in ribosome biogenesis, we carried out a screen for mutations that result in lethality in combination with mutations in DRS1, a Saccharomyces cerevisiae nucleolar DEAD-box protein required for synthesis of 60S ribosomal subunits. We identified the gene NOP7that encodes an essential protein. The temperature-sensitive nop7-1 mutation or metabolic depletion of Nop7p results in a deficiency of 60S ribosomal subunits and accumulation of halfmer polyribosomes. Analysis of pre-rRNA processing indicates that nop7 mutants exhibit a delay in processing of 27S pre-rRNA to mature 25S rRNA and decreased accumulation of 25S rRNA. Thus Nop7p, like Drs1p, is required for essential steps leading to synthesis of 60S ribosomal subunits. In addition, inactivation or depletion of Nop7p also affects processing at the A0, A1, and A2 sites, which may result from the association of Nop7p with 35S pre-rRNA in 90S pre-rRNPs. Nop7p is localized primarily in the nucleolus, where most steps in ribosome assembly occur. Nop7p is homologous to the zebrafish pescadillo protein necessary for embryonic development. The Nop7 protein contains the BRCT motif, a protein-protein interaction domain through which, for example, the human BRCA1 protein interacts with RNA helicase A.