High order kinoforms as a broadband achromatic diffractive optics for terahertz beams

We discuss thin optical structures that allow chromatic aberrations to be avoided in the THz domain. The paper contains the theoretical considerations, computer modeling and experimental evaluation of the high order kinoform diffractive elements in the THz range. According to the obtained results application of the high order kinoforms enables broadband operation in the THz range.

A uniform approach to the description of multicenter bonding

A novel method for investigating the multicenter bonding patterns in molecular systems by means of the so-called Electron Density of Delocalized Bonds (EDDB) is introduced and discussed.

Using the polymeric ouzo effect for the preparation of polysaccharide-based nanoparticles

The polymeric ouzo effect, a nanoprecipitation process, is used for the preparation of polysaccharide-based nanoparticles. Dextran, pullulan, and starch were esterified with hydrophobic carboxylic acid anhydrides to obtain hydrophobic polysaccharides, which are insoluble in water. The additional introduction of methacroyl residues offers the possibility to cross-link the generated nanostructures, which become insoluble in organic solvents. To make use of the ouzo effect for the formation of nanoparticles, the polymer has to be soluble in an organic solvent, which is miscible with water. Here, acetone and THF were used. Immediately after the organic polymer solution is added to water, nanoparticles are generated. The size of the nanoparticles can be adjusted between 50 and 200 nm by changing the concentration of the initial polysaccharide solution. The degree of hydrophobic substitution was shown to have a very minor effect on the particle size. Dispersions with solids contents of up to 2% were obtained. Furthermore, the mechanical properties of the nanoparticles were investigated with force microscopy, and it was shown by fluorescence correlation spectroscopy that a fluorescent dye could be encapsulated in the nanoparticles by the applied nanoprecipitation procedure.

Role of preprocedural glutathione concentrations in the prediction of major adverse cardiac events in patients with acute coronary syndrome treated with percutaneous coronary intervention

INTRODUCTION

Poor antioxidant protection of cardiomyocytes due to cardiac ischemia and low serum levels of reduced glutathione (GSH) may be associated with enhanced risk of coronary restenosis after primary percutaneous coronary intervention (pPCI).

OBJECTIVES

The aim of this study was to investigate whether preprocedural serum reduced GSH, reflecting the antioxidant status, may be predictive of major adverse cardiac events (MACE) in patients with acute coronary syndrome (ACS) treated with pPCI.

PATIENTS AND METHODS

Preprocedural serum GSH level was evaluated in 141 patients with ACS treated with pPCI with bare-metal stent (BMS) deployment. During a 15-month follow-up, 30 patients (mean age, 61 ±10 years) experienced a MACE. The remaining 111 subjects constituted the non-MACE group (mean age, 63 ±10 years).

RESULTS

The MACE group had significantly lower GSH levels compared with the non-MACE group (P <0.001); significant differences were also observed in a subgroup of type 2 diabetic patients (P <0.001). All patients were arbitrarily classified as having low (median, ≤1.39; 1.04-1.55 μmol/l) or high serum GSH (median, >2.26; 2.09-2.99 μmol/l; P <0.001). The Kaplan-Meier analysis showed a significantly longer MACE-free survival in patients with higher serum GSH (P <0.004). The Cox proportional hazards regression indicated that patients with lower GSH were 2.2 times more likely to experience MACE (95% confidence interval [CI], 1.2-3.9; P <0.02 for the whole group and 1.8-11.8 for diabetic patients; P <0.002).

CONCLUSIONS

Preprocedural GSH levels may be useful in the prediction of MACE in patients with ACS scheduled for pPCI and BMS deployment, especially in diabetic subjects.

Modeling of the optical system illuminated by quasi-monochromatic spatially incoherent light: new numerical approach

This Letter presents a new method for modeling of complex optical setups illuminated by quasi monochromatic spatially incoherent light. The algorithm provides better performance and quality than other modeling methods both for isoplanatic and nonisoplanatic systems. The algorithm maintains energy relations, image orientation, and magnification of the system. Computer modeling and experimental results are presented.

Mechanical properties of poly(dimethylsiloxane)-block-poly(2-methyloxazoline) polymersomes probed by atomic force microscopy

Poly(dimethylsiloxane)-block-poly(2-methyloxazoline) (PDMS-b-PMOXA) vesicles were characterized by a combination of dynamic light scattering (DLS), cryogenic transmission electron microscopy (cryo-TEM), and atomic force microscopy imaging and force spectroscopy (AFM). From DLS data, a hydrodynamic radius of ~150 nm was determined, and cryo-TEM micrographs revealed a bilayer thickness of ~16 nm. In AFM experiments on a silicon wafer substrate, adsorption led to a stable spherical caplike conformation of the polymersomes, whereas on mica, adsorption resulted also in vesicle fusion and formation of bilayer patches or multilayer stacks. This indicates a delicate balance between the mechanical stability of PDMS-b-PMOXA polymersomes on one hand and the driving forces for spreading on the other. A Young's modulus of 17 ± 11 MPa and a bending modulus of 7 ± 5 × 10(-18) J were derived from AFM force spectroscopy measurements. Therefore, the elastic response of the PDMS-b-PMOXA polymersomes to external stimuli is much closer to that of lipid vesicles compared to other types of polymersomes, such as polystyrene-block-poly(acrylic acid) (PS-b-PAA).

Application of explicitly localized molecular orbitals to electronic structure calculations

We have recently generalized the method for localizing orbitals on a set of predefined molecular fragments [Phys. Chem. Chem. Phys. 2012, 14, 546]. The regional localized molecular orbitals (RLMO) are well suited for exploiting the locality of electronic correlation at post-Hartree-Fock level of theory. In this paper, the adequacy of RLMO representation is tested in the second-order local Møller-Plesset (LMP2) perturbation theory. Two model systems, namely, n-pentadecane and trans-retinal, are considered. Adequacy of RLMO/LMP2 method is discussed in conjunction with 'exact' MP2 and Pipek-Mezey LMP2 calculations. It is demonstrated that RLMO/MP2 method reduces correlation space and reproduces more than 99% of the correlation energy.

Magnetosomes on surface: an imaging study approach

In this study, we deposited isolated magnetosomes from magnetotactic bacteria Magnetospirillum strain AMB-1 onto solid surfaces using spin coating (SC) and drop coating (DC) techniques. Four imaging techniques have been used to visualize the sample structure: scanning and transmission electron microscopy (SEM, TEM), atomic and magnetic force microscopy (AFM, MFM). Additionally, dynamic light scattering was applied to measure the hydrodynamic radius of agglomerated/aggregated magnetosomes in a liquid environment. This manuscript discusses observed differences between structures obtained by two deposition techniques, i.e. possible interactions and factors responsible for magnetosomes' formation, their morphology on surfaces as a result of agglomeration and aggregation phenomena. Moreover, topography and homogeneity of obtained structures as well as thickness of protein-based membrane were also examined and described. Using high-resolution TEM, we analyzed the size of magnetic cores, their crystal structure and quality. We found that the SC technique provides a homogenous layer of magnetosomes and hydrophilization of silicon surfaces improves the deposition of magnetosomes. However, due to strong hydrogen interaction to the hydrophilic silicone surface, the organic membrane of magnetosomes is mostly flattened. As a matter of fact, the size distributions of magnetosomes deposited by SC and DC techniques (logarithmic-normal tendency) differ from the Feret diameter distribution (normal). Furthermore, our study confirms the good crystalline quality of magnetosomes' cores. It also shows that they are magnetic in the all their volume.

[Tako-tsubo syndrome - a form of acute coronary syndrome or completely different clinical entity - a case report]

Tako-tsubo cardiomyopathy, also known as stress-induced cardiomyopathy, is a temporary left ventricular dysfunction characterised by acute retrosternal rest pain, ST - segment elevation, slight elevation of cardiac necrosis markers, preferential apical akinesia or hypokinesia with basal hypercontractility in echocardiography. Its clinical picture mimics an acute coronary syndrome. Coronary angiography reveals normal coronary arteries. The characteristic symptoms occur after emotional or physical strain. We report a case of woman admitted to the hospital who presented with symptoms of acute coronary syndrome with ST - segment elevation. Patient clinical presentation and tests results led to a diagnosis of tako-tsubo cardiomyopathy.

Proteasome inhibition potentiates antitumor effects of photodynamic therapy in mice through induction of endoplasmic reticulum stress and unfolded protein response

Photodynamic therapy (PDT) is an approved therapeutic procedure that exerts cytotoxic activity toward tumor cells by inducing production of reactive oxygen species such as singlet oxygen. PDT leads to oxidative damage of cellular macromolecules, including proteins that undergo multiple modifications such as fragmentation, cross-linking, and carbonylation that result in protein unfolding and aggregation. Because the major mechanism for elimination of carbonylated proteins is their degradation by proteasomes, we hypothesized that a combination of PDT with proteasome inhibitors might lead to accumulation of carbonylated proteins in endoplasmic reticulum (ER), aggravated ER stress, and potentiated cytotoxicity toward tumor cells. We observed that Photofrin-mediated PDT leads to robust carbonylation of cellular proteins and induction of unfolded protein response. Pretreatment of tumor cells with three different proteasome inhibitors, including bortezomib, MG132, and PSI, gave increased accumulation of carbonylated and ubiquitinated proteins in PDT-treated cells. Proteasome inhibitors effectively sensitized tumor cells of murine (EMT6 and C-26) as well as human (HeLa) origin to PDT-mediated cytotoxicity. Significant retardation of tumor growth with 60% to 100% complete responses was observed in vivo in two different murine tumor models (EMT6 and C-26) when PDT was combined with either bortezomib or PSI. Altogether, these observations indicate that combination of PDT with proteasome inhibitors leads to potentiated antitumor effects. The results of these studies are of immediate clinical application because bortezomib is a clinically approved drug that undergoes extensive clinical evaluations for the treatment of solid tumors.

Pentapeptides containing two dehydrophenylalanine residues--synthesis, structural studies and evaluation of their activity towards cathepsin C

Synthesis, structural and biological studies of pentapeptides containing two DeltaPhe residues (Z and E isomers) in position 2 and 4 in peptide chain were performed. All the investigated peptides adopted bent conformation and majority of them could exist as two different conformers in solution. Only pentapeptides, containing free N-termini appeared to act as weak inhibitors of cathepsin C with the slow-binding, competitive mechanism of inhibition, free acids being bound slightly better than their methyl esters. Results of molecular modeling suggested significant difference between peptides, depending of the type of amino acid residue in position 5 in peptide chain. Dehydropeptides containing Gly residue in this position may act as competitive slow-reacting substrates and therefore exhibit inhibitory-like properties.

[Dynamic sequences of MR in evaluation of anatomy and function of pelvic floor by perimenopausal women]

Pelvic organ prolapse is one of the most common disorders and it concerns over 50% of women over the age of fifty who gave birth.

BACKGROUND

The purpose of this study was to establish a clinically useful protocol of MR investigation in the assessment of pelvic organs position changes during rest and in time of Velsalva test

OBJECTIVE

The material includes 17 postmenopausal women (48- 59-years-old) who were examined due of lumbosacralis discopathy in MR division of USK 1 in Lodz since 2007. The examination was extended to pelvic organs imaging with the help of Velsalva test.

RESULTS

Having compared static and dynamic images of investigated group and results of reference lines measurements, we have found normal pelvic organ position comparing to the H line in case of 10 women, in case of 5 women there was just a small displacement--up to 2 cm under the H line--and in case of 2 other women 2 cm above the H line. We have also found substantial increase of P line length (over 25% during tenesmus) in women with pelvic floor disorders.

CONCLUSION

Dynamic MR imaging proves extremely useful in evaluation of pelvic organs position changes during rest and in time of Velsalva test.

Statins impair antitumor effects of rituximab by inducing conformational changes of CD20

BACKGROUND

Rituximab is used in the treatment of CD20+ B cell lymphomas and other B cell lymphoproliferative disorders. Its clinical efficacy might be further improved by combinations with other drugs such as statins that inhibit cholesterol synthesis and show promising antilymphoma effects. The objective of this study was to evaluate the influence of statins on rituximab-induced killing of B cell lymphomas.

METHODS AND FINDINGS

Complement-dependent cytotoxicity (CDC) was assessed by MTT and Alamar blue assays as well as trypan blue staining, and antibody-dependent cellular cytotoxicity (ADCC) was assessed by a 51Cr release assay. Statins were found to significantly decrease rituximab-mediated CDC and ADCC of B cell lymphoma cells. Incubation of B cell lymphoma cells with statins decreased CD20 immunostaining in flow cytometry studies but did not affect total cellular levels of CD20 as measured with RT-PCR and Western blotting. Similar effects are exerted by other cholesterol-depleting agents (methyl-beta-cyclodextrin and berberine), but not filipin III, indicating that the presence of plasma membrane cholesterol and not lipid rafts is required for rituximab-mediated CDC. Immunofluorescence microscopy using double staining with monoclonal antibodies (mAbs) directed against a conformational epitope and a linear cytoplasmic epitope revealed that CD20 is present in the plasma membrane in comparable amounts in control and statin-treated cells. Atomic force microscopy and limited proteolysis indicated that statins, through cholesterol depletion, induce conformational changes in CD20 that result in impaired binding of anti-CD20 mAb. An in vivo reduction of cholesterol induced by short-term treatment of five patients with hypercholesterolemia with atorvastatin resulted in reduced anti-CD20 binding to freshly isolated B cells.

CONCLUSIONS

Statins were shown to interfere with both detection of CD20 and antilymphoma activity of rituximab. These studies have significant clinical implications, as impaired binding of mAbs to conformational epitopes of CD20 elicited by statins could delay diagnosis, postpone effective treatment, or impair anti-lymphoma activity of rituximab.

Pioglitazone, a PPAR-gamma ligand, exerts cytostatic/cytotoxic effects against cancer cells, that do not result from inhibition of proteasome

Thiazolidinediones are oral antidiabetic agents that activate peroxisome proliferator-activated receptor-gamma (PPAR-gamma) and exert potent antioxidant and anti-inflammatory properties. It has also been shown that PPAR-gamma agonists induce G0/G1 arrest and apoptosis of malignant cells. Some of these effects have been suggested to result from inhibition of proteasome activity in target cells. The aim of our studies was to critically evaluate the cytostatic/cytotoxic effects of one of thiazolidinediones (pioglitazone) and its influence on proteasome activity. Pioglitazone exerted dose-dependent cytostatic/cytotoxic effects in MIA PaCa-2 cells. Incubation of tumor cells with pioglitazone resulted in increased levels of p53 and p27 and decreased levels of cyclin D1. Accumulation of polyubiquitinated proteins within cells incubated with pioglitazone suggested dysfunction of proteasome activity. However, we did not observe any influence of pioglitazone on the activity of isolated proteasome and on the proteolytic activity in lysates of pioglitazone-treated MIA PaCa-2 cells. Further, treatment with pioglitazone did not cause an accumulation of fluorescent proteasome substrates in transfected HeLa cells expressing unstable GFP variants. Our results indicate that pioglitazone does not act as a direct or indirect proteasome inhibitor.

Pioglitazone, a PPAR-gamma ligand, exerts cytostatic/cytotoxic effects against cancer cells, that do not result from inhibition of proteasome

Thiazolidinediones are oral antidiabetic agents that activate peroxisome proliferator-activated receptor-gamma (PPAR-gamma) and exert potent antioxidant and anti-inflammatory properties. It has also been shown that PPAR-gamma agonists induce G0/G1 arrest and apoptosis of malignant cells. Some of these effects have been suggested to result from inhibition of proteasome activity in target cells. The aim of our studies was to critically evaluate the cytostatic/cytotoxic effects of one of thiazolidinediones (pioglitazone) and its influence on proteasome activity. Pioglitazone exerted dose-dependent cytostatic/cytotoxic effects in MIA PaCa-2 cells. Incubation of tumor cells with pioglitazone resulted in increased levels of p53 and p27 and decreased levels of cyclin D1. Accumulation of polyubiquitinated proteins within cells incubated with pioglitazone suggested dysfunction of proteasome activity. However, we did not observe any influence of pioglitazone on the activity of isolated proteasome and on the proteolytic activity in lysates of pioglitazone-treated MIA PaCa-2 cells. Further, treatment with pioglitazone did not cause an accumulation of fluorescent proteasome substrates in transfected HeLa cells expressing unstable GFP variants. Our results indicate that pioglitazone does not act as a direct or indirect proteasome inhibitor.

Ser326Cys polymorphism in DNA repair genes hOGG1 in breast cancer women

Reduced DNA repair capacity can render a high risk of developing many types of cancer; including breast cancer. Polymorphisms in DNA repair genes may contribute the genetic instability and carcinogenesis. In the present work the distribution of genotypes and frequency of alleles of the Ser326Cys polymorphism of hOGG1 gene in breast cancer women were analysed. Blood samples were obtained from 100 women with breast cancer and control (n = 106). The polymorphism was determined by PCR-RFLP methods. No association between Ser326Cys polymorphism of hOGG1 and breast cancer risk was observed. The distribution of the genotypes of the Ser326Cys polymorphism in both control and patients did not differ significantly (p > 0.05) from those predicted by the Hardy-Weinberg distribution. There were no significant differences (p > 0.05) in genotype distributions and allele frequencies between subgroups assigned to histological stage. The results suggest that the Ser326Cys polymorphism of hOGG1 gene may not be linked with appearance and development of breast cancer in polish women.