Conceptual design of a macromolecular diffractometer for the Jülich high brilliance source.

In this work, a concept for a neutron diffractometer for high-resolution macromolecular structures has been developed within the Jülich High Brilliance Neutron Source (HBS) project. The SELENE optics are adapted to the requirements of the instrument to achieve a tunable low background neutron beam at mm2 scale sample area. With the optimized guide geometry, a low background neutron beam can be achieved at the small sample area with tunable divergence and size. For the 1 × 1 mm2 sample, a flux of 1.10 × 107 n/s/cm2 for 0.38° divergence is calculated in the 2-4 Å wavelength range, which is about 84.6% of the flux at MaNDi of the high-power spallation source SNS at ORNL. Virtual neutron scattering experiments have been performed to demonstrate the instrument's capabilities for studies of mm scale samples with large unit cells. Results of Vitesse simulations indicate that unit cell sizes of up to 200 Å are possible to be resolved with the proposed instrument.

Multi-angle in situ dynamic light scattering at a neutron spin echo spectrometer.

A new sample environment, called Bio-Oven, has been built for the Neutron Spin Echo (NSE) Spectrometer J-NSE Phoenix. It provides active temperature control and the possibility to perform Dynamic Light Scattering (DLS) measurements during the neutron measurement. DLS provides diffusion coefficients of the dissolved nanoparticles, and thus one can monitor the aggregation state of the sample on a time scale of minutes during the spin echo measurement times on the order of days. This approach helps to validate the NSE data or to replace the sample when its aggregation state influences the spin echo measurement results. The new Bio-Oven is an in situ DLS setup based on optical fibers decoupling the free space optics around the sample cuvette in a lightproof casing from the laser sources and the detectors. It collects light from three scattering angles simultaneously. Six different values of momentum transfer can be accessed by switching between two different laser colors. Test experiments were performed with silica nanoparticles with diameters ranging from 20 nm up to 300 nm. Their hydrodynamic radii were determined from DLS measurements and compared with the ones obtained by a commercial particle sizer. It was demonstrated that also the static light scattering signal can be processed and gives meaningful results. The protein sample apomyoglobin was used for a long-term test and in a first neutron measurement using the new Bio-Oven. The results prove that the aggregation state of the sample can be followed using in situ DLS along with the neutron measurement.

Olecranon fractures in children and adolescents: outcomes based on fracture fixation.

PURPOSE: Open reduction and internal fixation with a tension band construct is the standard treatment for displaced transverse intra-articular olecranon fractures. The purpose of this study is to describe the outcomes of tension band fixation of olecranon fractures in children, specifically assessing the need for revision fixation and hardware removal. METHODS: Patients less than 18 years of age diagnosed with a displaced transverse intra-articular olecranon fracture and treated with tension band fixation between 2008 and 2017 were retrospectively enrolled. Operative treatment was with tension band wire (TBW) or tension band suture (TBS) constructs. RESULTS: A total of 46 patients, 36 male and ten female with a mean age of 12.3 years (6 to 17), were included. Surgical fixation was with TBW in 17 patients and TBS in 29 patients. Revision fixation due to failure and fracture displacement was required in 6% of the TBW group and 14% of the TBS group (p = 0.19). The patients who required revision fixation in the TBS group were older (14.7 years versus 11.6 years, p = 0.05) and heavier (70.5 kg versus 48.5 kg, p = 0.05) than those in the same group who did not require revision fixation. CONCLUSION: Paediatric olecranon fractures treated with TBW or TBS fixation unite in the majority of patients with similar need for hardware removal due to prominence and/or pain between fixation techniques. In a select group of older patients weighing greater than 50 kg, TBS constructs demonstrate increased failure rates, requiring revision fixation, and should be avoided in this population group. LEVEL OF EVIDENCE: IV.

Molecular tweezers target a protein-protein interface and thereby modulate complex formation.

Molecular tweezers for lysine and arginine select a few residues on a protein surface and by their unique complexation mode disrupt a critical protein-protein interaction. Detailed structural information was gained by NMR experiments, strongly supported by QM/MM calculations and further substantiated by ITC, fluorescence anisotropy, ELISA and bio-layer-interference studies.

Unraveling the function of paralogs of the aldehyde dehydrogenase super family from Sulfolobus solfataricus.

Aldehyde dehydrogenases (ALDHs) have been well established in all three domains of life and were shown to play essential roles, e.g., in intermediary metabolism and detoxification. In the genome of Sulfolobus solfataricus, five paralogs of the aldehyde dehydrogenases superfamily were identified, however, so far only the non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase (GAPN) and α-ketoglutaric semialdehyde dehydrogenase (α-KGSADH) have been characterized. Detailed biochemical analyses of the remaining three ALDHs revealed the presence of two succinic semialdehyde dehydrogenase (SSADH) isoenzymes catalyzing the NAD(P)(+)-dependent oxidation of succinic semialdehyde. Whereas SSO1629 (SSADH-I) is specific for NAD(+), SSO1842 (SSADH-II) exhibits dual cosubstrate specificity (NAD(P)(+)). Physiological significant activity for both SSO-SSADHs was only detected with succinic semialdehyde and α-ketoglutarate semialdehyde. Bioinformatic reconstructions suggest a major function of both enzymes in γ-aminobutyrate, polyamine as well as nitrogen metabolism and they might additionally also function in pentose metabolism. Phylogenetic studies indicated a close relationship of SSO-SSALDHs to GAPNs and also a convergent evolution with the SSADHs from E. coli. Furthermore, for SSO1218, methylmalonate semialdehyde dehydrogenase (MSDH) activity was demonstrated. The enzyme catalyzes the NAD(+)- and CoA-dependent oxidation of methylmalonate semialdehyde, malonate semialdehyde as well as propionaldehyde (PA). For MSDH, a major function in the degradation of branched chain amino acids is proposed which is supported by the high sequence homology with characterized MSDHs from bacteria. This is the first report of MSDH as well as SSADH isoenzymes in Archaea.

Terahertz radiation induces spindle disturbances in human-hamster hybrid cells.

The aim of this study was to investigate and quantify the production of spindle disturbances in A(L) cells, a human-hamster hybrid cell line, by 0.106 THz radiation (continuous wave). Monolayer cultures in petri dishes were exposed for 0.5 h to 0.106 THz radiation with power densities ranging from 0.043 mW/cm(2) to 4.3 mW/cm(2) or were kept under sham conditions (negative control) for the same period. As a positive control, 100 µg/ml of the insecticide trichlorfon, which is an aneuploidy-inducing agent, was used for an exposure period of 6 h. During exposure, the sample containers were kept at defined environmental conditions in a modified incubator as required by the cells. Based on a total of 6,365 analyzed mitotic cells, the results of two replicate experiments suggest that 0.106 THz radiation is a spindle-acting agent as predominately indicated by the appearance of spindle disturbances at the anaphase and telophase (especially lagging and non-disjunction of single chromosomes) of cell divisions. The findings in the present study do not necessarily imply disease or injury but may be important for evaluating possible underlying mechanisms.

Integration of decentralized clinical data in a data warehouse: a service-oriented design and realization.

OBJECTIVES: In this paper we present a general concept and describe the difficulties for the integration of data from various clinical partners in one data warehouse using the Open European Nephrology Science Center (OpEN.SC) as an example. This includes a requirements analysis of the data integration process and also the design according to these requirements. METHODS: This conceptual approach based on the Rational Unified Process (RUP) and paradigm of Service-Oriented Architecture (SOA). RESULTS: Because we have to enhance the confidence of our partners in the OpEN.SC system and with this the willingness of them to participate, important requirements are controllability, transparency and security for all partners. Reusable and fine-grained components were found to be necessary when working with diverse data sources. With SOA the requested reusability is implemented easily. CONCLUSIONS: A key step in the development of a data integration process within such a health information system like OpEN.SC is to analyze the requirements. And to show that this is not only a theoretical work, we present a design - developed with RUP and SOA - which fulfills these requirements.

Toxicokinetics of p-tert-octylphenol in male and female Sprague-Dawley rats after intravenous, oral, or subcutaneous exposures.

This study was undertaken to characterize the toxicokinetics of p-tert-octylphenol (OP), a weak estrogenic compound, in male and female rats. Male and female Sprague-Dawley rats were given a single dose of OP either by oral gavage (50, 125 or 250 mg/kg), by intravenous (iv) injection (2, 4, or 8 mg/kg), or by subcutaneous (sc) injection (125 mg/kg). In a repeated dosing experiment, rats were given OP (oral) daily (25, 50, or 125 mg/kg) for 35 d (female) or 60 d (male). Blood and tissue samples were collected and analyzed for OP content using gas chromatography with detection by mass spectrometry. Blood OP concentrations were generally higher in female than male rats following a single oral or sc administration but were similar following a single iv injection. Tissue OP concentrations were also higher in female than male rats following oral exposure, consistent with the faster metabolism of OP observed in male rat liver microsomes. After subchronic administration, blood OP concentrations were higher at the end of exposure for female (33 d) (2.26-fold, not significant) and male (57 d) (3.47-fold) rats than single dosing but there was no change in the tissue OP concentrations. Gender differences in tissue OP concentrations may contribute, in part, to gender differences in the toxicity of OP in rats. The fact that OP was found in all reproductive tissues confirms its potential for direct endocrine-like effects.

[Anatomic pathology workflow. IHE: modeling based on current developments in HL7 and DICOM]. / Der Workflow in der Pathologie. IHE: Modellierung unter Berücksichtigung der aktuellen Entwicklungen in HL7 und DICOM.

AIMS: Consistent and complete information is essential for medical decision making. Anatomic pathology as a diagnostic discipline has a central role in the exchange of information between clinical departments throughout the diagnostic process. The IHE (Integrating the Healthcare Enterprise) has created an integration profile for information systems based on HL7 and DICOM standards. METHODS: Created by the IHE Anatomic Pathology working group, the integration profile (so-called Technical Framework) ensures the consistent management of data and material in the pathology laboratory information system (PLIS). HL7 and DICOM standards are taken into account. Communication processes both within and outside the institute are modelled using eight actors and 13 transactions. RESULTS: The IHE's Technical Framework covers basic business processes, provision of diagnostic services and includes requesting examinations, as well as image and report management. In particular, a consistent data model for incoming material, containers, cartridges and slides has been developed and approved by the standards committee.

The use of metabolising systems for in vitro testing of endocrine disruptors.

Legislation and prospective legislative proposals in for instance the USA, Europe, and Japan require, or may require that chemicals are tested for their ability to disrupt the hormonal systems of mammals. Chemicals found to test positive are considered to be endocrine active substances (EAS) and may be putative endocrine disruptors (EDs). To date, there is still little or no experience with incorporating metabolic and toxicokinetic aspects into in vitro tests for EAS. This is a situation in sharp contrast to genotoxicity testing, where in vitro tests are routinely conducted with and without metabolic capacity. Originally prepared for the Organisation of Economic Cooperation and Development (OECD), this detailed review paper reviews why in vitro assays for EAS should incorporate mammalian systems of metabolism and metabolic enzyme systems, and indicates how this could be done. The background to ED testing, the available test methods, and the role of mammalian metabolism in the activation and the inactivation of both endogenous and exogenous steroids are described. The available types of systems are compared, and the potential problems in incorporating systems in in vitro tests for EAS, and how these might be overcome, are discussed. Lastly, some recommendations for future activities are made.

Determination of p-tert-octylphenol in blood and tissues by gas chromatography coupled with mass spectrometry.

A sensitive and reproducible procedure using gas chromatography coupled with mass spectrometry is described for the determination of p-tert-octylphenol (OP), a persistent degradation product of alkylphenol ethoxylates that binds to the estrogen receptor in blood and tissues. The first step involved the extraction of blood (200 microL) or tissue homogenate (400 microL) with methyl tert-butyl ether, including p-tert-butylphenol (BP) as internal standard. After extraction, the sample was evaporated to dryness with a gentle stream of nitrogen at 45 degrees C, and OP and BP were derivatized with an acetylation reaction involving acetic anhydride and catalyzed by pyridine. Samples were then analyzed by a gas chromatograph equipped with a mass spectrometer (single ion monitoring) with a Varian VF-5ms capillary column. The limit of detection and the limit of quantification of the method in blood were 4.6 and 15.5 ng/mL, respectively. The linearity and reproducibility of the method were acceptable, with coefficients of variation of approximately 10% for blood and ranging between 9% and 27% for tissues. This method was applied to the determination of unchanged OP in blood and tissues obtained from Sprague-Dawley rats after oral and IV OP administration.

Ultrafast changes of molecular crystal structure induced by dipole solvation.

Femtosecond photoexcitation of organic chromophores in a molecular crystal induces strong changes of the electronic dipole moment via intramolecular charge transfer as is evident from transient vibrational spectra. The structural response of the crystal to the dipole change is mapped directly for the first time by ultrafast x-ray diffraction or diffuse scattering. Changes of diffracted and transmitted x-ray intensity demonstrate an angular rearrangement of molecules around excited dipoles following the 10 ps kinetics of charge transfer and leaving lattice plane spacings unchanged. Transient x-ray scattering is governed by solvation, masking changes of the chromophore molecular structure.

Secondary structure binding motifs of the jet cooled tetrapeptide model Ac-Leu-Val-Tyr(Me)-NHMe.

In this paper the structure of the isolated tetrapeptide model Ac-Leu-Val-Tyr(Me)-NHMe (Leu = leucine, Val = valine, Tyr = tyrosine) is investigated by mass- and isomer-selective IR/UV double resonance spectroscopy. Two isomers of this peptide are observed and in combination with force field, ab initio, and DFT calculations these structures are assigned to folded arrangements presenting two different secondary structure binding motifs: (a) a combined gamma-turn/beta-turn structure and (b) a triple gamma-turn structure, which is described for the first time for an isolated model system in the gas phase.

Formation of iodoacetic acids during cooking: interaction of iodized table salt with chlorinated drinking water.

Iodoacetic and chloroiodoacetic acids were formed when municipal chlorinated tap water was allowed to react with iodized (with potassium iodide) table salt or with potassium iodide itself. Iodoacetic acid was recently shown to be a potent cytotoxic and genotoxic agent. For analysis, samples were extracted with t-amyl methyl ether and converted to the corresponding methyl esters using methanol and sulfuric acid. The concentration of iodoacetic acid was determined by gas chromatography-mass spectrometry (GC-MS) using an authentic standard. The identities of iodoacetic and chloroiodoacetic acids were further confirmed by gas chromatography-high-resolution mass spectrometry (GC-HRMS). Certain influences of sodium hypochlorite and humic acid as well as the concentration of potassium iodide on the yields of these acids were investigated. The concentration of iodoacetic acid in tap water samples boiled with 2 g l-1 of iodized table salt was found to be in the 1.5 microg l-1 range, whilst the concentration of chloroiodoacetic acid was estimated to be three to five times lower.

Further examination of the effects of nitrosylation on Alternaria alternata mycotoxin mutagenicity in vitro.

Previously, Alternaria extract and metabolite mutagenicities+/-nitrosylation were characterized using Ames Salmonella strains TA98 and TA100, which are both reverted at GC sites. To examine other targets for mutation, the metabolites Altertoxin I (ATX I), Altenuene (ALT), Alternariol (AOH), Alternariol monomethyl ether (AME), Tentoxin (TENT), Tenuazonic acid (TA) and Radicinin (RAD) were reexamined+/-nitrosylation, using Ames Salmonella strain TA97, sensitive to frameshift mutations at a run of C's, as well as strains TA102 and TA104, reverted by base pair mutations at AT sites and more sensitive to oxidative damage. ATX I was also assessed for mammalian mutagenicity at the Hprt gene locus in Chinese hamster V79 lung fibroblasts and rat hepatoma H4IIE cells. When tested from 1 to 100 microg/plate without nitrosylation, ATX I was mutagenic in TA102+/-rat liver S9 for activation and weakly mutagenic in TA104+/-S9, demonstrating direct-acting AT base pair mutagenicity. AOH was also directly mutagenic at AT sites in TA102+/-S9 while AME was weakly mutagenic in TA102+/-S9 and TA104+S9. Nitrosylation of ATX I enhanced mutagenicity at AT sites in TA104+/-S9 but produced little change in TA102+/-S9 compared to native ATX I. However, nitrosylated ATX I generated a potent direct-acting frameshift mutagen at C sites in TA97+/-S9. While ATX I was not mutagenic in either V79 cells or H4IIE cells, 5 and 10 microg/ml nitrosylated ATX I produced a doubling of 6-thioguanine resistant V79 colonies and 0.5 and 1 microg/ml were mutagenic to H4IIE cells, becoming toxic at higher concentrations. These results suggest ATX I, AME and AOH induce mutations at AT sites, possibly through oxidative damage, with nitrosylation enhancing ATX I frameshift mutagenicity at runs of C's. Nitrosylated ATX I was also directly mutagenic in mammalian test systems.

[Study of efficiancy of teleconsultation: the Telepathology Consultation Service of the Professional Assoziation of German Pathologists for the screening program of breast carcinoma]. / Studie zur Effektivität der Telekonsultation: Der Telepathologie-konsultationsservice des Berufsverbandes Deutscher Pathologen im Rahmen des Mamma-Screening-Programms.

AIMS: In the autumn a German screening program was started for detecting breast cancer in the population of women fifty and above. For the first time in this program, quality assurance rules were established: All statements of the radiologists and pathologists have to be confirmed by a second opinion. This improvement in quality is combined with a delay in time and additional expence. A new Telepathology Consultation Service was developed based on the experiences of the Telepathology Consultation Center of the UICC to speed up the second opinion process. METHODS AND MATERIAL: The complete web-based service is operated under MS Windows 2003 Server, as web server the Internet Information Server, and the SQL-Server (both Microsoft) as the database. The websites, forms and control mechanism have been coded in by ASP scripts and JavaScript. A study to evaluate the effectiveness of telepathological consultation in comparison to conventional consultation has been carried out. Pathologists of the Professional Association of German Pathologists took part as well as requesting pathologists and as consultants for other participants. RESULTS AND CONCLUSION: The quality of telepathological diagnosis was comparable to the conventional diagnosis. Telepathology allows a faster respond of 1 to 2 day (conventional postal delay). The time to prepare a telepathology request is about twice as conventional. This ratio may be inverted by an interface between the Pathology Information System and the Telepathology Server and the use of virtual microscopy. The Telepathology Consultation Service of the Professional Association of German Pathologists is a fast and effective German-language, internet-based service for obtaining a second opinion.

New heterocyclic beta-sheet ligands with peptidic recognition elements.

A detailed and comprehensive overview is presented about the design, modeling, and synthesis, as well as spectroscopic characterization, of a new class of beta-sheet ligands. The characteristic feature of these compounds is a peptidic chimeric structure formed from a specific combination of aminopyrazolecarboxylic acids with naturally occurring alpha-amino acids. These hybrid peptides are designed with the aid of molecular modeling to exist mainly in an extended conformation. All their hydrogen bond donors and acceptors can be aligned at the bottom face in such a way that a perfect complementarity toward beta-sheets is obtained. Thus the aminopyrazoles impart rigidity and a highly efficient DAD sequence for the recognition of whole dipeptide fragments, whereas the natural alpha-amino acids are designed to mimick recognition sites in proteins, ultimately leading to sequence-selective protein recognition. The synthetic protocols either rely upon solution phase peptide coupling with a PMB protecting group strategy or solid-phase peptide coupling based on the Fmoc strategy, using the same protecting group. In solution, a key building block was prepared by catalytic reduction of a nitropyrazolecarboxylic acid precursor. Subsequently, it was (N-1)-protected with a PMB group, and elongated by HCTU- or T3P-assisted peptide coupling with dipeptide fragments, followed by PyClop-assisted coupling with another nitropyrazolecarboxylic acid building block. Final simultaneous deprotection of all PMB groups with hot TFA completed the high-yield protocol, which works racemization-free. After preparing a similar key building block with an Fmoc protection at N-3, we developed a strategy suitable for automated synthesis of larger hybrid ligands on a peptide synthesizer. Attachment of the first amino acid to a polystyrene resin over the Sieber amide linker is followed by an iterative sequence consisting of Fmoc deprotection with piperidine and subsequent coupling with natural alpha-amino acid via HATU/HOAt. High yields of free hybrid peptides are obtained after mild acidic cleavage from the resin, followed by deprotection of the PMB groups with hot TFA. The new aminopyrazole peptide hybrid compounds were characterized by various spectroscopic measurements including CD spectra, VT, and ROESY NMR experiments. All these accumulated data indicate the absence of any intramolecular hydrogen bonds and strongly support an extended conformation in solution, ideal for docking on to solvent-exposed beta-sheets in proteins. Initial results from aggregation tests of pathological proteins with these and related ligands look extremely promising.

Multipoint recognition of basic proteins at a membrane model.

Cell surface recognition achieves high efficiency and specificity because of its polyvalent nature. A biomimetic model has been designed, which consists of a stearic acid monolayer with embedded calixarene tetraphosphonate receptor molecules. This system is able to distinguish between proteins of varying pI at nanomolar concentrations.

[Esthetic rehabilitation of rhinophyma]. / Asthetische Rehabilitation beim Rhinophym.

BACKGROUND: Rhinophyma is an uncommon progressively disfiguring process of the nose which occurs most often in middle-aged white men. The supposed association with increased alcohol abuse often leads to psychological problems for the person concerned. PATIENTS AND METHODS: We describe ten cases of patients with slowly progressive tumorous deformation of the nose. They were treated with a stepwise surgical approach consisting of tangential excision for debulking, sculpting with scissors, and finally contouring by dermabrasion. RESULTS: An esthetically pleasing result was achieved in all cases, making social reintegration for the patients possible. In the follow-up of at least 12 months no recurrence was seen and no scars occurred.

A selective biomimetic tweezer for noradrenaline.

The new highly preorganized tweezer molecule 1 binds noradrenaline in polar solvents with unprecedented specificity. It uses a biomimetic recognition pattern and rejects almost all other neurotransmitters. LB experiments on a film balance reflect the same selectivity if 1 is incorporated into a stearic acid monolayer.