125I] 3-quinuclidinyl 4-iodobenzilate: a high affinity, high specific activity radioligand for the M1 and M2-acetylcholine receptors

We have prepared a radioiodinated ligand which binds with high affinity to the muscarinic acetylcholine receptor (m-AChR). A derivative of 3-quinuclidinyl benzilate, [125I] labeled (R) 1-aza-bicyclo(2.2.2)oct-3-yl (R,S)-alpha-hydroxy-alpha-(4-[125I]iodophenyl)phenyl acetate (4- IQNB ) exhibits an affinity for the m-AChR from corpus striatum higher than that of (R) [3H] QNB. Additionally, [125I] 4- IQNB exhibits receptor selectivity for the M1 receptor since the affinity for the receptor from dog and rat heart is lower than that using dog or rat corpus striatum.     

Prognostic usefulness of certain defined indicators for achieving complete remission and survival of ANLL in adults: proposal of a prognostic scale

Retrospective analysis has included 323 patients with acute nonlymphocytic leukaemia. The comparable patient groups were treated since 1981, according to protocols used by the Polish Acute Leukaemia Group. The prognostic value for achieving complete remission and survival of 67 pre-treatment factors (42 quantitative and 25 qualitative) was evaluated. The most important 9 parameters were scored according to their prognostic value as follows: age, percent of blasts in bone marrow, peripheral blood blast count, morphological subtype, percent of granulocytes in bone marrow, percent of blasts with CD-15 antigen, thrombocyte count, spleen/liver enlargement, CSF protein levels. Proposed scoring system enables classification of ANLL patients to a standard and high risk groups.     

Oral Administration of Polymyxin B Modulates the Activity of Lipooligosaccharide E. coli B against Lung Metastases in Murine Tumor Models

Introduction

Polymyxin B (PmB) belongs to the group of cyclic peptide antibiotics, which neutralize the activity of LPS by binding to lipid A. The aim of this study was to analyze the effect of PmB on the biological activity of lipooligosaccharide (LOS E. coli B,rough form of LPS) in vitro and in experimental metastasis models.

Results

Cultures of murine macrophage J774A.1 cells and murine bone marrow-derived dendritic cells (BM-DC) stimulated in vitro with LOS and supplemented with PmB demonstrated a decrease in inflammatory cytokine production (IL-6, IL-10, TNF-α) and down-regulation of CD40, CD80, CD86 and MHC class II molecule expression. Additionally, PmB suspended in drinking water was given to the C57BL/6 mice seven or five days prior to the intravenous injection of B16 or LLC cells and intraperitoneal application of LOS. This strategy of PmB administration was continued throughout the duration of the experiments (29 or 21 days). In B16 model, statistically significant decrease in the number of metastases in mice treated with PmB and LOS (p<0.01) was found on the 14th day of the experiments, whereas the most intensive changes in surface-antigen expression and ex vivo production of IL-6, IL-1β and TNF-α by peritoneal cells were observed 7 days earlier. By contrast, antigen expression and ex vivo production of IL-6, IL-10, IFN-γ by splenocytes remained relatively high and stable. Statistically significant decrease in LLC metastases number was observed after the application of LOS (p<0.01) and in the group of mice preconditioned by PmB and subsequently treated with LOS (LOS + PmB, p<0.01).

Conclusions

In conclusion, prolonged in vivo application of PmB was not able to neutralize the LOS-induced immune cell activity but its presence in the organism of treated mice was important in modulation of the LOS-mediated response against the development of metastases.     

Monitoring the correction of glycogen storage disease type 1a in a mouse model using [(18)F]FDG and a dedicated animal scanner

Monitoring gene therapy of glycogen storage disease type 1a in a mouse model was achieved using [(18)F]FDG and a dedicated animal scanner. The G6Pase knockout (KO) mice were compared to the same mice after infusion with a recombinant adenovirus containing the murine G6Pase gene (Ad-mG6Pase). Serial images of the same mouse before and after therapy were obtained and compared with wild-type (WT) mice of the same strain to determine the uptake and retention of [(18)F]FDG in the liver. Image data were acquired from heart, blood pool and liver for twenty minutes after injection of [(18)F]FDG. The retention of [(18)F]FDG was lower for the WT mice compared to the KO mice. The mice treated with adenovirus-mediated gene therapy had retention similar to that found in age-matched WT mice. These studies show that FDG can be used to monitor the G6Pase concentration in liver of WT mice as compared to G6Pase KO mice. In these mice, gene therapy returned the liver function to that found in age matched WT controls as measured by the FDG kinetics in the liver compared to that found in age matched wild type controls.     

Identification of metabolites of fluorine-18-labeled M2 muscarinic receptor agonist, 3-(3-[(3-fluoropropyl)thio]-1,2,5-thiadiazol-4-yl)-1,2,5,6-tetrahydro-1-methylpyridine, produced by human and rat hepatocytes

An accurate, rapid method for the determination of unmetabolized 3-(3-[(3-[18F]fluoropropyl)thio]-1,2,5-thiadiazol-4-yl)-1.2,5,6-tetrahydro-1-methylpyridine (FP-TZTP), a selective M2 muscarinic agonist, is necessary in order to obtain quantitative information from positron emission tomography (PET) imaging. Using LC-MS-MS to analyze products from cultured human and rat hepatocytes, we identified metabolites resulting from oxidation of the nitrogen in the tetrahydropyridine ring, sulfur-oxidation, demethylation of the tertiary amine, and oxidation of the tetrahydropyridine ring. From the knowledge of the structure of the metabolites, we have developed a two-step extraction sequence that allows rapid determination of the parent fraction in plasma without time-consuming chromatographic analysis.     

<Emphasis Type="Italic">TRAF1/C5</Emphasis>polymorphism is not associated with increased mortality in rheumatoid arthritis: two large longitudinal studies

Introduction  

Recently an association between a genetic variation in TRAF1/C5 and mortality from sepsis or cancer was found in rheumatoid arthritis (RA). The most prevalent cause of death, cardiovascular disease, may have been missed in that study, since patients were enrolled at an advanced disease stage. Therefore, we used an inception cohort of RA patients to investigate the association between TRAF1/C5 and cardiovascular mortality, and replicate the findings on all-cause mortality. As TRAF1/C5 associated mortality may not be restricted to RA, we also studied a large cohort of non-RA patients.     

Mesenchymal stem cells in autoimmune diseases: hype or hope?

Intervention with mesenchymal stem cells (MSCs) represents a promising therapeutic tool in treatment-refractory autoimmune diseases. A new report by Schurgers and colleagues in a previous issue of Arthritis Research & Therapy sheds novel mechanistic insight into the pathways employed by MSCs to suppress T-cell proliferation in vitro, but, at the same time, indicates that MSCs do not influence T-cell reactivity and the disease course in an in vivo arthritis model. Such discrepancies between the in vitro and in vivo effects of potent cellular immune modulators should spark further research and should be interpreted as a sign of caution for the in vitro design of MSC-derived interventions in the setting of human autoimmune diseases.     

Pentacycloundecane lactam vs lactone norstatine type protease HIV inhibitors: binding energy calculations and DFT study

Background

Novel pentacycloundecane (PCU)-lactone-CO-EAIS peptide inhibitors were designed, synthesized, and evaluated against wild-type C-South African (C-SA) HIV-1 protease. Three compounds are reported herein, two of which displayed IC₅₀ values of less than 1.00 μM. A comparative MM-PB(GB)SA binding free energy of solvation values of PCU-lactam and lactone models and their enantiomers as well as the PCU-lactam-NH-EAIS and lactone-CO-EAIS peptide inhibitors and their corresponding diastereomers complexed with South African HIV protease (C-SA) was performed. This will enable us to rationalize the considerable difference between inhibitory concentration (IC₅₀) of PCU-lactam-NH-EAIS and PCU-lactone-CO-EAIS peptides.

Results

The PCU-lactam model exhibited more negative calculated binding free energies of solvation than the PCU-lactone model. The same trend was observed for the PCU-peptide inhibitors, which correspond to the experimental activities for the PCU-lactam-NH-EAIS peptide (IC₅₀ = 0.076 μM) and the PCU-lactone-CO-EAIS peptide inhibitors (IC₅₀ = 0.850 μM). Furthermore, a density functional theory (DFT) study on the natural atomic charges of the nitrogen and oxygen atoms of the three PCU-lactam, PCU-lactim and PCU-lactone models were performed using natural bond orbital (NBO) analysis. Electrostatic potential maps were also used to visualize the electron density around electron-rich regions. The asymmetry parameter (η) and quadrupole coupling constant (χ) values of the nitrogen and oxygen nuclei of the model compounds were calculated at the same level of theory. Electronic molecular properties including polarizability and electric dipole moments were also calculated and compared. The Gibbs theoretical free solvation energies of solvation (∆G_solv) were also considered.

Conclusions

A general trend is observed that the lactam species appears to have a larger negative charge distribution around the heteroatoms, larger quadrupole constant, dipole moment and better solvation energy, in comparison to the PCU-lactone model. It can be argued that these characteristics will ensure better eletronic interaction between the lactam and the receptor, corresponding to the observed HIV protease activities in terms of experimental IC₅₀ data.

Electronic supplementary material

The online version of this article (doi:10.1186/s12929-015-0115-5) contains supplementary material, which is available to authorized users.