Maxillary calcifying epithelial odontogenic tumor with sinus and buccal vestibule extension: a case report and immunohistochemical study

Background

Calcifying epithelial odontogenic tumor (CEOT) is a rare benign neoplasia, locally aggressive, that tends to invade bone and adjacent soft tissues. This case report describes the thirteenth known case of CEOT with maxillary sinus extension and the second one that also involves the buccal vestibule mucosa with peculiar histopathological and immunohistochemical data.

Case presentation

Here we report the case of a 45-year-old female with a CEOT diagnosed and treated at the Oral & Maxillofacial Surgery Department, County Clinical Emergency Hospital of Craiova, Romania. The clinical and imaging investigation revealed an intraosseous tumor developed from the left posterior maxilla with maxillary sinus and buccal vestibule mucosa extension. Histopathology found an epithelium-rich CEOT variant, but with scattered S100 positive clear cells, focal small rounded cementum-like deposits and areas with some degree of nuclear pleomorphism. The immunohistochemical investigations emphasised its local aggressiveness behavior with involvement of multiple molecular mechanisms that underlie tumor invasiveness. A subtotal maxillectomy was performed followed by defect reconstruction.

Conclusions

We discuss the relevant clinicopathological features of an aggressive rare case of CEOT with maxillary sinus extension and buccal vestibule mucosa involvement. The immunohistochemical study suggests its utility in attempting to assess the degree of local tumor aggressiveness and thus in adopting the most efficient therapeutic attitude.

     

Erythrocytes do not activate purified and platelet soluble guanylate cyclases even in conditions favourable for NO synthesis

Background

Direct interaction between Red blood cells (RBCs) and platelets is known for a long time. The bleeding time is prolonged in anemic patients independent of their platelet count and could be corrected by transfusion of RBCs, which indicates that RBCs play an important role in hemostasis and platelet activation. However, in the last few years, opposing mechanisms of platelet inhibition by RBCs derived nitric oxide (NO) were proposed. The aim of our study was to identify whether RBCs could produce NO and activate soluble guanylate cyclase (sGC) in platelets.

Methods

To test whether RBCs could activate sGC under different conditions (whole blood, under hypoxia, or even loaded with NO), we used our well-established and highly sensitive models of NO-dependent sGC activation in platelets and activation of purified sGC. The activation of sGC was monitored by detecting the phosphorylation of Vasodilator Stimulated Phosphoprotein (VASP^S239) by flow cytometry and Western blot. ANOVA followed by Bonferroni’s test and Student’s t-test were used as appropriate.

Results

We show that in the whole blood, RBCs prevent NO-mediated inhibition of ADP and TRAP6-induced platelet activation. Likewise, coincubation of RBCs with platelets results in strong inhibition of NO-induced sGC activation. Under hypoxic conditions, incubation of RBCs with NO donor leads to Hb-NO formation which inhibits sGC activation in platelets. Similarly, RBCs inhibit activation of purified sGC, even under conditions optimal for RBC-mediated generation of NO from nitrite.

Conclusions

All our experiments demonstrate that RBCs act as strong NO scavengers and prevent NO-mediated inhibition of activated platelets. In all tested conditions, RBCs were not able to activate platelet or purified sGC.

     

The Tomato Nucleotide-binding Leucine-rich Repeat Immune Receptor I-2 Couples DNA-binding to Nucleotide-binding Domain Nucleotide Exchange

Plant nucleotide-binding leucine-rich repeat (NLR) proteins enable plants to recognize and respond to pathogen attack. Previously, we demonstrated that the Rx1 NLR of potato is able to bind and bend DNA in vitro. DNA binding in situ requires its genuine activation following pathogen perception. However, it is unknown whether other NLR proteins are also able to bind DNA. Nor is it known how DNA binding relates to the ATPase activity intrinsic to NLR switch function required to immune activation. Here we investigate these issues using a recombinant protein corresponding to the N-terminal coiled-coil and nucleotide-binding domain regions of the I-2 NLR of tomato. Wild type I-2 protein bound nucleic acids with a preference of ssDNA ≈ dsDNA > ssRNA, which is distinct from Rx1. I-2 induced bending and melting of DNA. Notably, ATP enhanced DNA binding relative to ADP in the wild type protein, the null P-loop mutant K207R, and the autoactive mutant S233F. DNA binding was found to activate the intrinsic ATPase activity of I-2. Because DNA binding by I-2 was decreased in the presence of ADP when compared with ATP, a cyclic mechanism emerges; activated ATP-associated I-2 binds to DNA, which enhances ATP hydrolysis, releasing ADP-bound I-2 from the DNA. Thus DNA binding is a general property of at least a subset of NLR proteins, and NLR activation is directly linked to its activity at DNA.     

Volatile anesthetics affect the morphology of rat glioma C6 cells via RhoA, ERK, and Akt activation

Treatment of rat glioma C6 cells with the beta-receptor agonist isoproterenol induces a massive increase in cAMP. Concomitantly the cells change their morphology from a fibroblast-type to an astrocyte-like (stellated) cell shape. The stellated morphology can be completely reverted by thrombin and sphingosine-1-phosphate (S-1-P) but also to a certain extent by clinical concentrations of volatile anesthetics. The anesthetic-induced reversion of the stellated cell shape seems to be mediated by a number of cellular alterations. Central to the effect is most likely a RhoA/Rho-kinase activation, but also the MAPKK/MEK and the Akt/protein kinase B pathway are activated by the anesthetics. With the use of specific inhibitors we were able to show that activation of the MAPKK/MEK pathway inhibits, whereas activation of the Akt/protein kinase B pathway stimulates the reversal of the stellated cell shape by the anesthetics. In summary, volatile anesthetics affect the morphology of rat glioma C6 cells by activation of the RhoA/Rho kinase, the MAPKK/MEK, and the Akt/protein kinase B signaling pathways.     

A multi-endpoint matched molecular pair (MMP) analysis of 6-membered heterocycles

Aromatic rings, ubiquitous in pharmaceutical compounds, are often exchanged with another ring during the optimization process of drug discovery. Inevitably, the preferred ring system for one endpoint may prove detrimental to another, thus necessitating a holistic, multiple endpoint optimization approach for finding the ideal replacement. Accordingly, we conducted an extensive matched molecular pair (MMP) analysis of common 6-membered aromatic rings across 4 endpoints critical for drug discovery (log D lipophilicity, microsomal metabolism, P-gp efflux and passive permeability). We also investigated the effect of context by considering the connecting atom. Heat maps were created as a simple yet comprehensive way to view and analyze the vast amount of interrelated data. Paired difference statistical tests were used to identify transforms with changes that were significantly different from zero. We conclude that the heat maps of transforms provide a unique and powerful approach for multiparameter optimization.     

Evidence that tartrate-resistant acid phosphatases from osteoclastomas and hairy cell leukemia spleen are members of a multigene family.

1. Osteoclasts and hairy cell leukemia spleen both contain large amounts of a band 5-tartrate-resistant acid phosphatase (TrACP). 2. We have recently purified to homogeneity a band 5 TrACP from human osteoclastomas and two isoforms of band 5 TrACP (5a and 5b) from the spleen of a patient with hairy cell leukemia. 3. Although the N-terminal amino acid sequences and the apparent molecular weights of the osteoclastoma, hairy cell leukemia spleen TrACPs were identical, there were several differences in the physical and biochemical properties between the three isoenzymes. 4. Based on these findings, it is concluded that these isoenzymes are different enzymes, but that they could have originated from a similar ancestral gene. 5. It is proposed that the osteoclastoma and hairy cell leukemia band 5 TrACPs are members of a multigene family.     

The Position of His-Tag in Recombinant OspC and Application of Various Adjuvants Affects the Intensity and Quality of Specific Antibody Response after Immunization of Experimental Mice

Lyme disease, Borrelia burgdorferi-caused infection, if not recognized and appropriately treated by antibiotics, may lead to chronic complications, thus stressing the need for protective vaccine development. The immune protection is mediated by phagocytic cells and by Borrelia-specific complement-activating antibodies, associated with the Th1 immune response. Surface antigen OspC is involved in Borrelia spreading through the host body. Previously we reported that recombinant histidine tagged (His-tag) OspC (rOspC) could be attached onto liposome surfaces by metallochelation. Here we report that levels of OspC-specific antibodies vary substantially depending upon whether rOspC possesses an N'' or C'' terminal His-tag. This is the case in mice immunized: (a) with rOspC proteoliposomes containing adjuvants MPLA or non-pyrogenic MDP analogue MT06; (b) with free rOspC and Montanide PET GEL A; (c) with free rOspC and alum; or (d) with adjuvant-free rOspC. Stronger responses are noted with all N''-terminal His-tag rOspC formulations. OspC-specific Th1-type antibodies predominate post-immunization with rOspC proteoliposomes formulated with MPLA or MT06 adjuvants. Further analyses confirmed that the structural features of soluble N'' and C'' terminal His-tag rOspC and respective rOspC proteoliposomes are similar including their thermal stabilities at physiological temperatures. On the other hand, a change in the position of the rOspC His-tag from N'' to C'' terminal appears to affect substantially the immunogenicity of rOspC arguably due to steric hindrance of OspC epitopes by the C'' terminal His-tag itself and not due to differences in overall conformations induced by changes in the His-tag position in rOspC variants.