Measurement of the beta+ and orbital electron-capture decay rates in fully ionized, hydrogenlike, and heliumlike 140Pr ions

We report on the first measurement of the beta+ and orbital electron-capture decay rates of 140Pr nuclei with the simplest electron configurations: bare nuclei, hydrogenlike, and heliumlike ions. The measured electron-capture decay constant of hydrogenlike 140Pr58+ ions is about 50% larger than that of heliumlike 140Pr57+ ions. Moreover, 140Pr ions with one bound electron decay faster than neutral 140Pr0+ atoms with 59 electrons. To explain this peculiar observation one has to take into account the conservation of the total angular momentum, since only particular spin orientations of the nucleus and of the captured electron can contribute to the allowed decay.

Polar nano-rods under shear: from equilibrium to chaos

The orientational dynamics of rod-like particles with permanent (electric or magnetic) dipole moments in a plane Couette shear flow is investigated using mesoscopic relaxation equations combined with a generalized Landau free energy. The free energy contribution due to the coupling between average alignment and dipole orientation is derived on a microscopic basis. Numerical results of the resulting eight-dimensional dynamical system are presented for the case of longitudinal dipoles and thermodynamic conditions where the equilibrium state is a (polar or non-polar) nematic. Solution diagrams reveal presence of a large variety of periodic, transient chaotic, and chaotic dynamic states of the average alignment and dipole moment, respectively, appearing as a function of Deborah number and tumbling parameter. Compared to rods without dipoles we observe a significant preference of out-of-plane kayaking-tumbling states and, generally, a higher sensitivity to the initial conditions including bistability. We also demonstrate that the average (electric) dipole moment characterizing most of the observed states yields electrodynamic (magnetic) fields of measurable strength.

Effect of structural and conformation modifications, including backbone cyclization, of hydrophilic hexapeptides on their intestinal permeability and enzymatic stability

A library of 18 hexapeptide analogs was synthesized, including sub-libraries of N- or C-methylation of the parent hexapeptide Phe-Gly-Gly-Gly-Gly-Phe, as well as backbone cyclized analogs of each linear analog with various ring sizes. N- or C-methylation as well as cyclization (but not backbone cyclization) have been suggested to improve intestinal permeability and metabolic stability of peptides in general. Here we aimed to assess their applicability to hydrophilic peptides. The intestinal permeability (Papp) of the 18-peptide library was in the range of 0.2-6.8 x 10-6 cm/sec. Based on several tests, we concluded that the absorption mechanism of all tested analogs is paracellular, regardless of the structural or conformational modifications. In all cases, backbone cyclization increased Papp (5-fold) in comparison to the linear analogs due to the smaller 3D size and also dramatically decreased peptide proteolysis by brush border enzymes. N- or C-methylation did not enhance the permeability of the linear analogs in this series.

Radiative electron capture to the continuum and the short-wavelength limit of electron-nucleus bremsstrahlung in 90A MeV U88 + ((1s2)(2s2))+N2 Collisions

We have measured the continuum momentum distribution for radiative electron capture to the continuum (RECC) cusp electrons in 90A MeV U88+ + N2-->U88+ + N2 +* + ecusp(0 degrees ) + hnu (RECC) collisions. We demonstrate that x rays coincident with RECC cusp electrons originate from the short-wavelength limit of the electron-nucleus bremsstrahlung and explain the asymmetric cusp shape by comparison with theory within the relativistic impulse approximation.

Endothelial cell-matrix interactions determine maturation of dendritic cells

The fate of allo- and xenogeneic endothelial cell (EC) implants is regulated by EC-matrix interactions. While free EC are destroyed by a vigorous immune reaction, EC embedded within 3D collagen cells are well tolerated. Given the critical role DC serve in immune reactivity, we hypothesized that EC-driven DC maturation depends on EC-matrix contact. In marked contrast to DC co-cultured with a cytokine cocktail or with allo- and xenogeneic EC grown to confluence on 2D tissue culture plates, DC exposed to 3D matrix-embedded allo- and xenogeneic EC failed to mature, retaining their endocytic activity and exhibiting significantly reduced expression of maturation markers (costimulatory molecules, HLA-DR, CD83; p <0.01). Matrix-embedded EC also limited cytokine-induced maturation and activity of DC. Incubation with matrix-embedded EC inhibited DC induction of allogeneic lymphocyte proliferation (p <0.002) and EC cross-activation (ICAM-1, VCAM-1, HLA-DR, TLR2 and 4; p <0.01). The endothelium in its quiescent state is confluent and substrate adherent. The former ensures secretion of growth inhibitors rather than promoters, and the latter may ensure immune acceptance. We now demonstrate for the first time that interactions of EC with an underlying 3D matrix affect the ability of EC to drive DC maturation.

Endothelial immunogenicity--a matter of matrix microarchitecture

The endothelium is a highly specialized active interface between blood and the underlying tissues, maintaining vascular tone, thrombo-resistance and selective permeability to cells and proteins. It is also an important regulator of inflammatory diseases, and endothelial-leukocyte interactions often herald complex diseases with an inflammatory component. Yet, the exact mechanisms promoting immune activation of endothelial cells (EC) are incompletely understood. Knowledge is accumulating that the immediate environment defines the cellular phenotype, whereby matrix composition and spatial formation (three- versus two-dimensional) seem to act as pivotal mediators. Here we summarize current findings denoting a key role of matrix environment in regulating endothelial immunogenicity. The immune response to three-dimensional matrix-embedded EC stands in stark contrast to the response engendered by injection of these same cells in their free state. Matrix-embedding confers a quiescent endothelial state with reduced expression levels of chemokines, adhesion, costimulatory, and major histocompatibility complex II molecules. Compared to EC grown on two-dimensional tissue culture plates, cytokine-stimulation of matrix-embedded EC results in significantly reduced adhesion of natural killer cells and proliferation of co-cultivated allogeneic T cells. On the contrary, matrix-embedded EC induce an immune-inhibitory phenotype of dendritic cells and T regulatory cells to a greater extent than non-embedded EC. As vascular diseases are associated with profound changes in basement membrane composition and overall tissue architecture, our results indicate that the immediate environment of EC might play a pivotal role in initiating and regulating of different vascular diseases. Cell-matrix interconnections appear to govern endothelial immunogenicity and interactions between EC and immune cells.

Effect of MCM09, an active site-directed inhibitor of factor Xa, on B16-BL6 melanoma lung colonies in mice

BACKGROUND

Treatment with anticoagulant drugs has shown potential inhibitory effect on tumor invasion, although the relationship with clotting inhibition was not clear.

AIM

The aim of our study was to evaluate the potential antitumor activity of MCM09, a newly developed, active site-directed, small molecule inhibitor of factor Xa (FXa) [WO0216312], and to relate the findings to anticlotting potency.

METHODS

MCM09 (0.1-10 mg kg(-1)) or heparin (H; 10 mg kg(-1)) was injected intravenously (i.v.), with 5 x 10(4) B16-BL6 melanoma cells, in C57BL/6 mice. Mice were killed after 18 days, to count lung colonies. Ex vivo anticoagulant activity was measured by activated partial thromboplastin time (APTT) on mouse plasma.

RESULTS AND CONCLUSIONS

MCM09, a selective inhibitor of FXa (IC-50 = 2.4 nm against human FXa), inhibited in a dose-dependent manner B16-BL6 melanoma lung colonies in mice. Mean lung metastasis number was 20.9 +/- 4.8 in controls (n = 10), 1.2 +/- 0.4 in mice treated with H, 10 mg kg(-1) i.v. (P < 0.01), 0.9 +/- 0.3, 9.2 +/- 2.2 and 15.5 +/- 2.6 in mice treated with MCM09, at 10 (P < 0.01), 1 (P < 0.05) and 0.1 mg kg(-1) i.v. (ns), respectively. MCM09 (10 mg kg(-1) i.v.) significantly prolonged APTT (57.1 +/- 10.2 s) 30 min after i.v. injection when compared with controls (25.3 +/- 1.6 s; P < 0.05). Lung colonies were 74.2-72.6% reduced by MCM09 (10 mg kg(-1)) given 60 or 120 min before cells, but not by MCM09 given 60 min thereafter, suggesting a direct cell interaction as a mechanism underlying antitumor activity.

Keratoacanthoma centrifugum marginatum accompanied by extensive granulomatous foreign body reaction

We describe a 58-year-old woman with a 4-year history of papular lesions with a partly verruciform appearance on the eyelids and the adjacent areas of the nose. The lesions progressed slowly but constantly into the surrounding areas with central scarring. Histopathology showed epidermal endophytic proliferations under a pronounced hyperparakeratosis. In the adjacent dermis a lymphohistiocytic infiltrate with giant cells of the foreign-body-reaction type was seen in close contact to extracellular keratin deposits. Although some cytopathological signs typical for viropathic effects were observed, no human papilloma virus-DNA was detected within the lesions by polymerase chain reaction. According to the histological picture and the clinical course we diagnosed a keratoacanthoma centrifugum marginatum. We present this case because of the strong granulomatous foreign body reaction which might complicate the diagnosis and has not been described for this keratoacanthoma variant so far.

Investigation of the enhancing mechanism of sodium N-[8-(2-hydroxybenzoyl)amino]caprylate effect on the intestinal permeability of polar molecules utilizing a voltage clamp method

Oral administration of sodium N-[8-(2-hydroxybenzoyl)amino]caprylate (SNAC) has been reported to increase the bioavailability of various macromolecules. The present study was aimed to study the effect of SNAC on the intestinal tissue permeability of polar charged molecules, using 6-carboxy-fluorescein (6-CF) as a model. The effects of SNAC on rat intestinal permeability was investigated ex vivo by utilizing voltage clamp experiments in a side-by-side diffusion chamber model in comparison with the effect of EDTA (10mM). The intestinal permeability of 6-CF was increased two-fold in the presence of 33-66 mM SNAC, and by 6.5-fold in the presence of 10mM EDTA. The voltage clamp experiments show that the effect of SNAC was particularly on the transcellular 7-folds increase (that was five times larger than the paracellular transport of the model agent). While EDTA affected predominantly paracellular pathway transport, SNAC 33-66 mM had no effect on [(3)H]-mannitol transport or any toxic effect on tissue integrity measured by TEER values. In conclusion, this study demonstrates that SNAC can facilitate passive transport of polar charged molecules through the membrane of epithelial enterocytes. This is noteworthy in view of the very low tendency of a charged molecule to permeate across the lipophilic inter-phase of the enterocytes membrane.

Red-light cameras for the prevention of road traffic crashes

BACKGROUND

Road crashes are a prime cause of death and disability and red-light running is a common cause of crashes at signalised intersections. Red-light cameras are increasingly used to promote compliance with traffic signals. Manual enforcement methods are resource intensive and high risk, whereas red-light cameras can operate 24 hours a day and do not involve high-speed pursuits.

OBJECTIVES

To quantify the impact of red-light cameras on the incidence and severity of road crashes and casualties, and the incidence of red-light violations.

SEARCH STRATEGY

We searched the following electronic databases: TRANSPORT (NTIS, TRIS, IRRD,TRANSDOC), Cochrane Injuries Group Specialised Register, Cochrane Controlled Trials Register, MEDLINE, EMBASE and the Australian Transport Index. We checked the reference lists of relevant papers and contacted research and advocacy organisations.

SELECTION CRITERIA

Randomised or quasi-controlled trials and controlled before-after studies of red-light cameras. For crash impact evaluation, the before and after periods each had to be at least one year in length. For violation studies, the after period had to occur at least one year after camera installation.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data on study type, characteristics of camera and control areas, and data collection period. Before-after data were collected on number of crashes by severity, collision type, deaths and injuries, and red-light violations. Rate ratio was calculated for each study. Where there was more than one, rate ratios were pooled to give an overall estimate, using a generic inverse variance method and a random-effects model.

MAIN RESULTS

No randomised controlled trials were identified but 10 controlled before-after studies from Australia, Singapore and the USA met our inclusion criteria. We grouped them according to the extent to which they adjusted for regression to the mean (RTM) and spillover effects. Total casualty crashes: the only study that adjusted for both reported a rate ratio of 0.71 (95% CI to 0.55, 0.93); for three that partially adjusted for RTM but failed to consider spillover, rate ratio was 0.87 (95% CI to 0.77, 0.98); one that made no adjustments had a rate ratio of 0.80 (95% CI 0.58 to 1.12). Right-angle casualty crashes: rate ratio for two studies that partially addressed RTM was 0.76 (95% CI 0.54 to 1.07). Total crashes: the study addressing both RTM and spillover reported a rate ratio of 0.93 (95% CI 0.83 to 1.05); one study that partially addressed RTM had a rate ratio of 0.92 (95% CI 0.73 to 1.15); the pooled rate ratio from the five studies with no adjustments was 0.74 (95% CI 0.53 to 1.03). Red-light violations: one study found a rate ratio of 0.53 (95% CI 0.17 to 1.66).

AUTHORS' CONCLUSIONS

Red-light cameras are effective in reducing total casualty crashes. The evidence is less conclusive on total collisions, specific casualty collision types and violations, where reductions achieved could be explained by the play of chance. Most evaluations did not adjust for RTM or spillover, affecting their accuracy. Larger and better controlled studies are needed.

Petasites hybridus extracts in vitro inhibit COX-2 and PGE2 release by direct interaction with the enzyme and by preventing p42/44 MAP kinase activation in rat primary microglial cells

Rhizomes of butterbur, Petasites hybridus L. (Asteraceae), have been used since ancient times for the treatment of inflammatory diseases. In the present study, the effects of lipophilic extracts from rhizomes of Petasites hybridus on the formation and release of prostaglandin E2 were investigated. The extracts had different contents of petasin and isopetasin: A: 2.1 % and 0.4 %, B: 0.2 % and 0.1 %, C: 12.1 % and 6.1 % and D: 21.9 % and 9.4 %, respectively. Direct inhibition of cyclooxygenase (COX) -1 and -2 isoenzymes and inhibition of the expression of COX-2 and p42/44 MAP kinase in rat primary microglial cells were tested. All extracts were found to be only weak direct inhibitors of COX-1 (IC50> 400 microg/mL). However, most extracts revealed a strong inhibitory activity against the inducible isoform COX-2 ( A: IC50=30.4 microg/mL; B: IC50=60.6 microg/mL; C: IC50=22.6 microg/mL; D: IC50=20.0 microg/mL). This activity was not correlated to the content of petasin and isopetasin. Pure petasin and isopetasin neither inhibited COX-1 nor COX-2 (IC50 > 400 microM for both compounds and enzymes). Petasites extracts dose-dependently inhibited LPS-induced and thus COX-2-mediated PGE2 release in primary rat microglial cells (A: IC50= 2.4 microg/mL; C: IC50=5.8 microg/mL and D: IC50=4.6 microg/mL). Also this effect was independent from the petasin and isopetasin content. COX-2 synthesis in microglia was totally blocked with 5 microg/mL of C whereas COX-1 synthesis was not influenced. C and D did not affect the LPS-induced activation of p38 MAPK and IkappaBalpha, but they prevented the LPS-induced activation of p42/44 MAPK. Therefore, these Petasites hybridus extracts can be regarded as natural selective inhibitors of COX-2 and its expression, an effect which is independent from the petasin content.

Femtosecond time-resolved guanine oxidation in acridine modified alanyl peptide nucleic acids

Alanyl peptide nucleic acids have been designed to generate linear and rigid pairing complexes. Femtosecond time resolved electron transfer dynamics studies of alanyl-PNA double strands where both strands contain an intercalated 9-amino-6-chloro-2-methoxy-acridine in its protonated state reveal a strong similarity to nearest neighbor interstrand/intrastrand guanine oxidation in the corresponding B-DNA fragment. This observation implies that the combined influence of electronic couplings and energetic parameters, driving force and reorganization energy, on electron transfer dynamics is similar in both structures. With respect to the alanyl-PNA structure, this result is consistent with the notion of stacking distances in the nucleobase staple similar to the one in B-DNA and thus provides additional structural evidence for nucleobase stacking in alanyl-PNA double strands.

Evaluation of shoulder internal rotator muscle strength in baseball players with physical signs of glenohumeral joint instability

OBJECTIVES

To identify whether subjects with glenohumeral translational instability present with a strength deficit in their internal rotator musculature, and therefore to determine if general strengthening exercises are warranted for the management of this condition.

METHODS

Eighteen male baseball players were allocated to two groups on the basis of expert clinical evaluation of the presence (n=8) or absence (n=10) of shoulder translational instability. A strain gauge was used to calculate the force generated during maximal isometric internal rotation contractions in neutral shoulder rotation and 30 degrees of internal rotation.

RESULTS

The Mann-Whitney test identified no significant difference in force production during the maximum contractions in neutral rotation between the two subject groups. In the position of 30 degrees shoulder internal rotation, subjects with glenohumeral translational instability produced significantly greater force than the control group (p<0.05).

CONCLUSIONS

High load strength testing cannot be used as a diagnostic tool to identify people with glenohumeral instability. Similarly, heavy resistance strengthening exercises for the internal rotator musculature are not warranted during rehabilitation.

Validierung von microMESAM® als Screeningsystem für schlafbezogene Atmungsstörungen

INTRODUCTION

Polysomnography (PSG) is considered the gold standard in the diagnosis of sleep disordered breathing (SDB). Because of costs and labor-intensity it is, however, performed last in graded diagnostic protocols that often involve respiratory pressure measurements via nasal canula as an alternative sensitive method for SDB detection. MicroMESAM, a newly developed screening device based on this method, allows automated analysis of apnoeas, hypopnoeas and snoring.

AIM AND METHODS

To validate the device, we first compared signal quality of MicroMESAM flow-time curves with those generated by a pneumotachograph. Then, in 50 patients suspected of having obstructive sleep apnoea, we compared MicroMESAM-generated automated analysis with manually scored results of simultaneously collected PSG data.

RESULTS

MicroMESAM-generated flow-time curves correspond with pneumotachograph-generated curves in 95% of respiratory events, resulting in less 4 +/- 2% difference in respective area under the curves. MicroMESAM and PSG generated numbers of apnoeas (r = 0.99) and hypopnoea (r = 0.81), as well as AHI (r = 0.98) correlated highly, displaying mean differences in AHI of 3.8, and in 1.96 sigma interval of + 11.1 to - 3.5/h. Sensitivities and specificities for SDB were 97.3%, respective 46% at SDB-defining AHI of 5, and 100%, respective 87.5%, at SDB-defining AHI of 10.

SUMMARY

MicroMESAM-generated flow-time curves correspond well with pneumotachograph generated curves, producing automated AHIs that are highly sensitive in detecting SDB. MicroMESAM, therefore, is suitable as a screening device for SDB.

The molecular structure of spider dragline silk: folding and orientation of the protein backbone

The design principles of spider dragline silk, nature's high-performance fiber, are still largely unknown, in particular for the noncrystalline glycine-rich domains, which form the bulk of the material. Here we apply two-dimensional solid-state NMR to determine the distribution of the backbone torsion angles (phi,psi) as well as the orientation of the polypeptide backbone toward the fiber at both the glycine and alanine residues. Instead of an "amorphous matrix," suggested earlier for the glycine-rich domains, these new data indicate that all domains in dragline silk have a preferred secondary structure and are strongly oriented, with the chains predominantly parallel to the fiber. As proposed previously, the alanine residues are predominantly found in a beta sheet conformation. The glycine residues are partly incorporated into the beta sheets and otherwise form helical structures with an approximate 3-fold symmetry.

Ultrafast electron transfer in the complex between fluorescein and a cognate engineered lipocalin protein, a so-called anticalin

Anticalins are a novel class of engineered ligand-binding proteins with tailored specificities derived from the lipocalin scaffold. The anticalin FluA complexes fluorescein as ligand with high affinity, and it effects almost complete quenching of its steady-state fluorescence. To study the underlying mechanism, we have applied femtosecond absorption spectroscopy, which revealed excited-state electron transfer within the FluA*Fl complex to be responsible for the strong fluorescence quenching. On the basis of a comparison of redox potentials, either tryptophan or tyrosine may serve as electron donor to the bound fluorescein group in its excited singlet state, thus forming the fluorescein trianion radical within 400 fs. The almost monoexponential rate points to a single, well-defined binding site, and its temperature independence suggests an (almost) activationless process. Applying conventional electron transfer theory to the ultrafast forward and slower back-rates, the resulting electronic interaction is rather large, with approximately 140 cm(-1) for tyrosine, which would be consistent with a coplanar arrangement of both aromatic moieties within van der Waals distance. The weak residual steady-state fluorescence originates from a small (approximately 10%) component with a time constant in the 40-60 ps range. These results demonstrate the power of time-resolved absorption spectroscopy as a diagnostic tool for the elucidation of a fluorescence quenching mechanism and the temporal profiles of the processes involved. The high structural and dynamic definition of the complexation site suggests the anticalin FluA to be a promising model in order to tailor and probe electronic interactions and energetics in proteins.

Profiling indomethacin impurities using high-performance liquid chromatography and nuclear magnetic resonance

The anti-inflammatory drug indomethacin was investigated regarding new related impurities. Therefore, related substances 2-9 were prepared by independent synthesis and physicochemically characterized. To determine indomethacin and its related substances, a new HPLC-UV method was developed and validated. Indomethacin and its impurities were eluted on a C(18) column with a mobile phase consisting of methanol and an aqueous solution of 0.2% phosphoric acid at a flow rate of 1.5 ml/min and were quantified by UV detection at 320 nm. Overall, the HPLC-UV method was simple and reliable for the detection of eight impurities in indomethacin. In addition to the HPLC-UV method, 1H nuclear magnetic resonance (NMR) was used to investigate indomethacin regarding impurities. For that purpose, related substances 2-9 were systematically added to indomethacin and investigated. The NMR method was found to be very useful for the identification of impurities in bulk substance without prior separation. Both HPLC-UV and NMR were used to analyze 38 batches of indomethacin available on the European market. The outcome was that 42% of the batches did not meet the compendial requirements although they met the specifications of current compendial methods. Some batches contained the previously undescribed impurity 8, while other batches contained by-products from two distinct synthetic routes. The methods presented herein are important contributions to the ongoing efforts to reduce impurities and therefore the risk of adverse side-effects in drugs that are no longer under patent protection.

Solid-state NMR data support a helix-loop-helix structural model for the N-terminal half of HIV-1 Rev in fibrillar form

Rev is a 116 residue basic protein encoded by the genome of human immunodeficiency virus type 1 (HIV-1) that binds to multiple sites in the Rev response element (RRE) of viral mRNA transcripts in nuclei of host cells, leading to transport of incompletely spliced and unspliced viral mRNA to the cytoplasm of host cells in the latter phases of the HIV-1 life cycle. Rev is absolutely required for viral replication. Because Rev aggregates and fibrillizes in solution at concentrations required for crystal growth or liquid state NMR measurements, high-resolution structural characterization of full-length Rev has not been possible. Previously, circular dichroism studies have shown that approximately 50 % of the Rev sequence adopts helical secondary structure, predicted to correspond to a helix-loop-helix structural motif in the N-terminal half of the protein. We describe the application of solid-state NMR techniques to Rev fibrils as a means of obtaining site-specific, atomic-level structural constraints without requiring a high degree of solubility or crystallinity. Solid-state NMR measurements, using the double-quantum chemical shift anisotropy and constant-time double-quantum-filtered dipolar recoupling techniques, provide constraints on the phi and psi backbone dihedral angles at sites in which consecutive backbone carbonyl groups are labeled with (13)C. Quantitative analysis of the solid-state NMR data, by comparison with numerical simulations, indicates helical phi and psi angles at residues Leu13 and Val16 in the predicted helix 1 segment, and at residues Arg39, Arg 42, Arg43, and Arg44 in the predicted helix 2 segment. These data represent the first site-specific structural constraints from NMR spectroscopy on full-length Rev, and support the helix-loop-helix structural model for its N-terminal half.