Бесплатный обязательный экземпляр полиграфических и других изданий как один из источников комплектования Латвийской академической библиотеки

Aggregation of amyloid beta (Aβ) into oligomers and fibrils is believed to play an important role in the development of Alzheimer's disease (AD). To gain further insight into the principles of aggregation, we have investigated the induction of β-sheet secondary conformation from disordered native peptide sequences through lipidation, in 1-2% hexafluoroisopropanol (HFIP) in phosphate buffered saline (PBS). Several parameters, such as type and number of lipid chains, peptide sequence, peptide length and net charge, were explored keeping the ratio peptide/HFIP constant. The resulting lipoconjugates were characterized by several physico-chemical techniques: Circular Dichroism (CD), Attenuated Total Reflection InfraRed (ATR-IR), Thioflavin T (ThT) fluorescence, Dynamic Light Scattering (DLS), solid-state Nuclear Magnetic Resonance (ssNMR) spectroscopy and Electron Microscopy (EM). Our data demonstrate the generation of β-sheet aggregates from numerous unstructured peptides under physiological pH, independent of the amino acid sequence. The amphiphilicity pattern and hydrophobicity of the scaffold were found to be key factors for their assembly into amyloid-like structures

(5,6:19,20-Dibenzo-1,4,11,14-tetra­oxa-8,17-diaza­cyclo­eicosane-κ4 N 8,O 11,O 14,N 17)dinitrato-κ4 O,O′-cadmium(II)

In the title compound, [Cd(NO3)2(C22H30N2O4)], the CdII atom is eight-coordinated by two amine N atoms and two O atoms from the 5,6:19,20-dibenzo-1,4,11,14-tetra­oxa-8,17-diaza­cyclo­eicosane ligand and four O atoms from two nitrate groups. The coordination geometry about Cd is antiprismatic. One nitro O atom is disordered equally over two positions

Структурные изменения в системе гемостаза у больных меланомой кожи на ранней стадии ее развития

Мета дослідження – оцінка показників системи гемостазу у 27 хворих на меланому шкіри. Виявлено подовження активованого часткового тромбопластинового часу, подовження часткового тромбопластинового часу, подовження часу рекальцифікації, зниження рівня антитромбіну III, підвищення рівня розчинних фібрін-мономерних комплексів. Таким чином, мають місце серйозні структурні зміни системного гемостазу - гіпокоагуляція і гіперфібриноліз. Діагностика та корекція цих змін допоможе поліпшити клінічний перебіг і прогноз захворювання.A research aim is an estimation of indexes of the system of hemostasis at 27 patients by the melanoma of skin. Lengthening of the activated partial tromboplastin time, lengthening of partial tromboplastin time, lengthening of time of recalcification, decline of level of antithrombin of III, increase of level of soluble fibrinmonomers complexes is educed. Thus, the serious structural changes in the system of hemostasis - incoagulability and hyperfibrinolysis take place. Diagnostics and correction of these changes will help to improve a clinical flow and prognosis of disease

Discovery and Structure Activity Relationship of Small Molecule Inhibitors of Toxic β-Amyloid-42 Fibril Formation

Increasing evidence implicates Aβ peptides self-assembly and fibril formation as crucial events in the pathogenesis of Alzheimer disease. Thus, inhibiting Aβ aggregation, among others, has emerged as a potential therapeutic intervention for this disorder. Herein, we employed 3-aminopyrazole as a key fragment in our design of non-dye compounds capable of interacting with Aβ42 via a donor-acceptor-donor hydrogen bond pattern complementary to that of the β-sheet conformation of Aβ42. The initial design of the compounds was based on connecting two 3-aminopyrazole moieties via a linker to identify suitable scaffold molecules. Additional aryl substitutions on the two 3-aminopyrazole moieties were also explored to enhance π-π stacking/hydrophobic interactions with amino acids of Aβ42. The efficacy of these compounds on inhibiting Aβ fibril formation and toxicity in vitro was assessed using a combination of biophysical techniques and viability assays. Using structure activity relationship data from the in vitro assays, we identified compounds capable of preventing pathological self-assembly of Aβ42 leading to decreased cell toxicity

T cell independent antibody responses with class switch and memory using peptides anchored on liposomes

Abstract Vaccines generally require T lymphocytes for B-cell activation and immunoglobulin class switching in response to peptide or protein antigens. In the absence of T cells, limited IgG class switch takes place, germinal centers are short-lived, and the B cells lack memory. Here, immunization of mice with liposomes containing 15mer peptides and monophosphoryl lipid A (MPLA) as adjuvant, induced T-cell independent (TI) IgG class switch within three days, as well as germinal center formation. The antibody responses were long-lived, strictly dependent on Toll-like receptor 4 (TLR4) signaling, partly dependent on Bruton’s tyrosine kinase (BTK) signal transmission, and independent of signaling through T-cell receptors, MHC class II and inflammasome. The antibody response showed characteristics of both TI type 1 and TI type 2. All IgG subclasses could be boosted months after primary immunization, and the biological function of the secreted antibodies was demonstrated in murine models of allergic anaphylaxis and of bacterial infection. Moreover, antibody responses after immunization with peptide- and MPLA-loaded liposomes could be triggered in neonatal mice and in mice receiving immune-suppressants. This study demonstrates T-cell independent endogenous B-cell memory and recall responses in vivo using a peptide antigen. The stimulation of these antibody responses required a correct and dense assembly and administration of peptide and adjuvant on the surface of liposomes. In the future, TI vaccines may prove beneficial in pathological conditions in which T-cell immunity is compromised through disease or medicines or when rapid, antibody-mediated immune protection is needed

Characterization of β-sheet amyloid-like aggregates of Palm1–15.

<p>A) CD spectra at 30 µM peptide Palm1–15 (green) and controls Acetyl1–15 (red) and Aβ1–15 (orange) in 2% HFIP/PBS (v/v). B) Profile of ThT emission with different peptide concentrations in the presence of 24 µM of dye. Fluorescence was measured at 485 nm with excitation at 440 nm. C, D, E) ssNMR of Palm1–15 uniformly labeled at Ala2, Ser8 and Gly9: (¹³C-¹³C) 2D PDSD correlation spectra with mixing times of 20 ms (C) and 150 ms (D); ¹H-¹³C FSLG-HETCOR spectra (E) together with chemical shift predictions based on secondary structure <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0105641#pone.0105641-Wang1" target="_blank">[38]</a> (red for random coil, green for β-sheet, blue for α-helix). F) Electron micrographs of negatively stained Palm1–15 aggregates formed over 24 hour incubation in 2% HFIP/PBS (v/v). Samples were negatively stained with 2% Uranyl Acetate in water. Scale bar 0.1 µm. Magnification 22000 x.</p

Peptide sequences of lipopeptides and controls.

<p>Peptide sequences of lipopeptides and controls.</p

Parameters influencing scaffold conformation.

<p>A) CD spectra and B) ThT fluorescence of tetrapalmitoylated peptides with shortened length, 9 or 5 amino acids (Palm1–9 in blue and Palm1–5 in orange respectively) or different order of amino acids, reverse or scrambled (Palm15-1 in green and scPalm15 in red, respectively) to model sequence Palm1–15. C) CD and D) ThT of tetrapalmitoylated peptides with different isoelectric point with pI (and net charge) value indicated on top of each column (Palm1–15(D7K) in green, Palm1–15(E3A, D7K) in blue, Palm1–15(E3K, D7K) in orange, Palm1–15(E3K, D7K, E11K) in red and Palm1–15 in black). E) CD and F) ThT of peptides with different number/position of palmitic chains (Palm1–15(1C) in orange, Palm1–15(2C) in red, Palm1–15(1N1C) in green, Palm1–15(4C) in blue and Palm1–15 in black). G) CD and H) ThT of peptides acylated with different lipid chain length (Acetyl1–15 in orange, Butyl1–15 in blue, Octyl1–15 in green, Dodecyl1–15 in red and Palm1–15 in black). Peptides were 30 µM in 2% HFIP/PBS (v/v) (CD) and 15 µM in 1% HFIP/PBS (v/v) (ThT, 24 µM). Fluorescence was measured at 485 nm with excitation at 440 nm. Values are the average of 3 replicates, normalized to the Palm1–15 emission (taken as 100%).</p

Regret about surgical decisions among early-stage breast cancer patients: Effects of the congruence between patients' preferred and actual decision-making roles

Early-stage breast cancer patients generally receive either a mastectomy or a lumpectomy, either by their own choice or that of their surgeon. Sometimes, there is regret about the decision afterward. To better understand regret about surgical decisions, this study examined 2 possibilities: The first is that women who take a dominant or collaborative role in decision making about the surgery express less regret afterward. The second is that congruence between preferred role and actual role predicts less regret. We also explored whether disease stage moderates the relationship between role congruence and decisional regret. In a cross-sectional design, 154 women diagnosed with breast cancer completed a survey assessing decisional role preference and actual decisional role, a measure of post-decision regret, and a measure of disturbances related to breast cancer treatment. Hierarchical regression was used to investigate prediction of decisional regret. Role congruence, not actual decisional role, was significantly associated with less decisional regret, independent of all the control variables. The interaction between disease stage and role congruence was also significant, showing that mismatch relates to regret only in women with more advanced disease. Our findings suggest that cancer patients could benefit from tailored decision support concerning their decisional role preferences in the complex scenario of medical and personal factors during the surgical decision