Photosensitised Multiheme Cytochromes as Light-Driven Molecular Wires and Resistors.

Multiheme cytochromes possess closely packed redox-active hemes arranged as chains spanning the tertiary structure. Here we describe five variants of a representative multiheme cytochrome engineered as biohybrid phototransducers for converting light into electricity. Each variant possesses a single Cys sulfhydryl group near a terminus of the heme chain, and this was efficiently labelled with a RuII (2,2'-bipyridine)3 photosensitiser. When irradiated in the presence of a sacrificial electron donor (SED) the proteins exhibited different types of behaviour. Certain proteins were rapidly and fully reduced. Other proteins were rapidly semi-reduced but resisted complete photoreduction. These findings reveal that photosensitised multiheme cytochromes can be engineered to act as resistors, with intrinsic regulation of light-driven electron accumulation, and also as molecular wires with essentially unhindered photoreduction. It is proposed that the observed behaviour arises from interplay between the site of electron injection and the distribution of heme reduction potentials along the heme chain.

Acute Whole-Body Vibration does not Facilitate Peak Torque and Stretch Reflex in Healthy Adults.

The acute effect of whole-body vibration (WBV) training may enhance muscular performance via neural potentiation of the stretch reflex. The purpose of this study was to investigate if acute WBV exposure affects the stretch induced knee jerk reflex [onset latency and electromechanical delay (EMD)] and the isokinetic knee extensor peak torque performance. Twenty-two subjects were randomly assigned to the intervention or control group. The intervention group received WBV in a semi-squat position at 30° knee flexion with an amplitude of 0.69 mm, frequency of 45 Hz, and peak acceleration of 27.6 m/s(2) for 3 minutes. The control group underwent the same semii-squatting position statically without exposure of WBV. Two-way mixed repeated measures analysis of variance revealed no significant group effects differences on reflex latency of rectus femoris (RF) and vastus lateralis (VL; p = 0.934 and 0.935, respectively) EMD of RF and VL (p = 0.474 and 0.551, respectively) and peak torque production (p = 0.483) measured before and after the WBV. The results of this study indicate that a single session of WBV exposure has no potentiation effect on the stretch induced reflex and peak torque performance in healthy young adults. Key PointsThere is no acute potentiation of stretch reflex right after whole body vibration.Acute whole body vibration does not improve mus-cle peak torque performance in healthy young adults.

Taming Reversible Halftoning via Predictive Luminance.

Traditional halftoning usually drops colors when dithering images with binary dots, which makes it difficult to recover the original color information. We proposed a novel halftoning technique that converts a color image into a binary halftone with full restorability to its original version. Our novel base halftoning technique consists of two convolutional neural networks (CNNs) to produce the reversible halftone patterns, and a noise incentive block (NIB) to mitigate the flatness degradation issue of CNNs. Furthermore, to tackle the conflicts between the blue-noise quality and restoration accuracy in our novel base method, we proposed a predictor-embedded approach to offload predictable information from the network, which in our case is the luminance information resembling from the halftone pattern. Such an approach allows the network to gain more flexibility to produce halftones with better blue-noise quality without compromising the restoration quality. Detailed studies on the multiple-stage training method and loss weightings have been conducted. We have compared our predictor-embedded method and our novel method regarding spectrum analysis on halftone, halftone accuracy, restoration accuracy, and the data embedding studies. Our entropy evaluation evidences our halftone contains less encoding information than our novel base method. The experiments show our predictor-embedded method gains more flexibility to improve the blue-noise quality of halftones and maintains a comparable restoration quality with a higher tolerance for disturbances.

Oxidative addition or Werner coordination complex? Reactivity of ß-diketiminate supported main group and first-row transition metal complexes towards ammonia.

A series of neutral LM (L = [HC{(H3C)C(Dipp)N}2], Dipp = 2,6-iPr2C6H3, M = group 13: B-In, TM: Fe, Co, Ni, Cu) and L'M (L' = [HC{(CCH2)(CCH3)(DippN)2}], M = group 14: C-Pb) compounds including a main group 13/14 and first-row transition metal complexes were studied computationally by density functional theory (DFT). The optimised complexes were assessed in terms of structural parameters and electronic structures to find trends and characteristics that could be used to predict their reactivity towards ammonia. In addition, the differences in oxidative addition and Werner coordination complex formation depending on the identity of the central element were investigated and the Werner complexes were evaluated by QTAIM and EDA-NOCV approaches. The computational results complement the earlier experimental studies and shed light on the feasibility of isolating novel main group Werner complexes or transition metal oxidative addition products.

Indoor radon exposure and its correlation with the radiometric map of uranium in Sweden.

Indoor radon concentrations are controlled by both human factors and geological factors. It is important to separate the anthropogenic and geogenic contributions. We show that there is a positive correlation between the radiometric map of uranium in the ground and the measured radon in the household in Sweden. A map of gamma radiation is used to obtain an equivalent uranium concentration (ppm eU) for each postcode area. The aggregated uranium content is compared to the yearly average indoor radon concentration for different types of houses. Interestingly, modern households show reduced radon concentrations even in postcode areas with high average uranium concentrations. This shows that modern construction is effective at reducing the correlation with background uranium concentrations and minimizing the health risk associated with radon exposure. These correlations and predictive housing parameters could assist in monitoring higher risk areas.

Difluoroethylamines as an amide isostere in inhibitors of cathepsin K.

The trifluoroethylamine group found in cathepsin K inhibitors like odanacatib can be replaced by a difluoroethylamine group. This change increased the basicity of the nitrogen which positively impacted the log D. This translated into an improved oral bioavailability in pre-clinical species. Difluoroethylamine compounds exhibit a similar potency against cathepsin K and selectivity profile against other cathepsins when compared to trifluoroethylamine analogs.

The discovery of MK-0674, an orally bioavailable cathepsin K inhibitor.

MK-0674 is a potent and selective cathepsin K inhibitor from the same structural class as odanacatib with a comparable inhibitory potency profile against Cat K. It is orally bioavailable and exhibits long half-life in pre-clinical species. In vivo studies using deuterated MK-0674 show stereoselective epimerization of the alcohol stereocenter via an oxidation/reduction cycle. From in vitro incubations, two metabolites could be identified: the hydroxyleucine and the glucuronide conjugate which were confirmed using authentic synthetic standards.

CHARGE syndrome patient with novel CHD7 mutation presenting with severe laryngomalacia and feeding difficulty.

We report a case of CHARGE syndrome with atypical phenotype and a novel mutation in the CHD7 gene. Laryngomalacia and swallowing difficulties are prominent features in this case. These are commonly found in patients with CHARGE syndrome and are well described in previous studies. However, with the traditional diagnostic criteria, diagnosis is difficult without the presence of coloboma or choanal atresia. Early diagnosis is possible with the aid of clinical genetics. The current diagnostic criteria would need to be broadened with the inclusion of pathogenic CHD7 variant status as a major criterion. Further research on the function of CHD7 gene may also give us more insight on the pathogenic mechanism of various clinical features of CHARGE syndrome.

Discovery of [(3-bromo-7-cyano-2-naphthyl)(difluoro)methyl]phosphonic acid, a potent and orally active small molecule PTP1B inhibitor.

A series of quinoline/naphthalene-difluoromethylphosphonates were prepared and were found to be potent PTP1B inhibitors. Most of these compounds bearing polar functionalities or large lipophilic residues did not show appreciable oral bioavailability in rodents while small and less polar analogs displayed moderate to good oral bioavailability. The title compound was found to have the best overall potency and pharmacokinetic profile and was found to be efficacious in animal models of diabetes and cancer.

Hemodynamic Effects of Noninvasive Positive-Pressure Ventilation Assessed Using Transthoracic Echocardiography.

AIMS: The aim of this study is to measure the effect of positive-pressure ventilation on heart chamber dimensions, left ventricular (LV) systolic function, LV diastolic function, right ventricular (RV) systolic function, and RV pressure using transthoracic echocardiography. SETTINGS AND DESIGN: This is a prospective study in a single secondary health-care center. MATERIALS AND METHODS: A total of 107 patients with obstructive sleep apnea on continuous positive airway pressure (CPAP) therapy were recruited as participants between April and September 2016. Transthoracic echocardiography was performed twice on each participant, before and 15 min after, they used their own CPAP machines, and the echocardiography parameters of both scans were compared. STATISTICAL ANALYSIS USED: The parametric paired t-test was used to compare heart chamber dimensions, left heart diastolic function, left heart systolic function, right heart systolic function, and right heart pressure effect, without and with CPAP. These data were further examined among several subgroups defined by CPAP when the cutoff point was set at 8 cmH2O and 10 cmH2O. The level of significance was set at 0.05. Statistical analyses were performed using IBM SPSS version 22 (IBM, Armonk, NY, USA). RESULTS: There were statistically significant reductions, after the application of CPAP, in the heart dimensions, and LV and RV systolic function. There were no significant changes in diastolic function. Concerning right heart pressure, with CPAP, there was a significant increase in the inferior vena cava (IVC) diameter and there was also a significant decrease in IVC variability from 44.56% ± 14.86% to 36.12% ± 11.42%. The maximum velocity of tricuspid regurgitation (TR) decreased significantly from 180.66 ± 6.95 cm/s to 142.30 ± 52.73 cm/s. Such changes were observed in both low and high CPAP subgroups. CONCLUSIONS: When placed on positive pressure, the clinically significant change in IVC diameter and variability and change in trans-TR velocity mean that it would be inaccurate to predict right heart chamber pressure through echocardiogram. Alternative methods for predicting right heart pressure are recommended.

Functionalized silk assembled from a recombinant spider silk fusion protein (Z-4RepCT) produced in the methylotrophic yeast Pichia pastoris.

Functional biological materials are a growing research area with potential applicability in medicine and biotechnology. Using genetic engineering, the possibility to introduce additional functions into spider silk-based materials has been realized. Recently, a recombinant spider silk fusion protein, Z-4RepCT, was produced intracellularly in Escherichia coli and could after purification self-assemble into silk-like fibers with ability to bind antibodies via the IgG-binding Z domain. In this study, the use of the methylotrophic yeast Pichia pastoris for production of Z-4RepCT has been investigated. Temperature, pH and production time were influencing the amount of soluble Z-4RepCT retrieved from the extracellular fraction. Purification of secreted Z-4RepCT resulted in a mixture of full-length and degraded silk proteins that failed to self-assemble into fibers. A position in the C-terminal domain of 4RepCT was identified as being subjected to proteolytic cleavage by proteases in the Pichia culture supernatant. Moreover, the C-terminal domain was subjected to glycosylation during production in P. pastoris. These observed alterations of the CT domain are suggested to contribute to the failure in fiber assembly. As alternative approach, Z-4RepCT retrieved from the intracellular fraction, which was less degraded, was used and shown to retain ability to assemble into silk-like fibers after enzymatic deglycosylation.

The C3a receptor antagonist SB 290157 has agonist activity.

The anaphylatoxin C3a is an important immune regulator with a number of distinct functions in both innate and adaptive immunity. Many of these roles have been ascribed to C3a based on studies in mice genetically modified to lack its precursor, C3, or its receptor, C3aR. However, other presumed functions of C3a are based on results obtained with a recently described small molecule ligand of C3aR, SB 290157. Although this compound was originally described as an antagonist and appears to act as such in some systems, it has recently been shown to have effects that cannot be explained by simple antagonism of C3aR. In the current study, SB 290157 is shown to have full agonist activity on C3aR in a variety of cell systems, including a calcium mobilization assay in transfected RBL cells, a beta-lactamase assay in CHO-NFAT-bla-Galpha(16) cells and an enzyme-release assay in differentiated U-937 cells. On the other hand, the compound lacks agonist activity in guinea pig platelets, cells known to express C3aR at very low levels. SB 290157 agonism of C3aR is consistent with recent discrepant data obtained using this molecule. These results caution against attributing novel roles to C3a based on data obtained with SB 290157 and highlight a continuing need for the identification of true small molecule C3aR antagonists.

Detection and prevention of medication misadventures in general practice.

BACKGROUND: Adverse drug events are leading categories of iatrogenic patient injury. Development of preventive strategies for general practice setting depends on effective detection of events. OBJECTIVE: The aim of the study is to compare the strengths and weaknesses of voluntary reporting, chart review and patient survey in measuring medication misadventures in general practice and to analyze the events by severity and preventability, drug groups and patients' and doctors' characteristics, for the formulation of preventive strategies. METHOD: In the 2-month study period, we applied voluntary report, chart review and patient survey to collect data related to medication misadventures and compared their detection rate. RESULTS: The chart review demonstrated the highest yield for detecting overall medication misadventures (2.03% medication orders), followed by patient survey (1.46% medication orders) and voluntary reporting (0.52% medication orders). Chart review and patient survey were better than voluntary reporting in uncovering preventable adverse drug events. However, voluntary reporting was pivotal in capturing sentinel events. Beta-blocker, diuretic, angiotensin-converting enzyme inhibitor, aspirin and non-steroidal anti-inflammatory drugs had caused 82.0% of all adverse drug events. These events were more common with advanced age of patients, greater number of consultation problems and prescribed drug items. Additional resources implicated were minimal. CONCLUSION: We suggested a complementary approach using chart review and voluntary reporting in measuring and monitoring medication misadventures in general practice. Close monitoring of the events was necessary for older patients, multiple medical problems and poly-pharmacy and for patients using beta-blocker, diuretic, angiotensin-converting enzyme inhibitor, aspirin or non-steroidal anti-inflammatory drugs on a long-term basis.

Conformation-assisted inhibition of protein-tyrosine phosphatase-1B elicits inhibitor selectivity over T-cell protein-tyrosine phosphatase.

PTP-1B represents an attractive target for the treatment of type 2 diabetes and obesity. Given the role that protein phosphatases play in the regulation of many biologically relevant processes, inhibitors against PTP-1B must be not only potent, but also selective. It has been extremely difficult to synthesize inhibitors that are selective over the highly homologous TCPTP. We have successfully exploited the conservative Leu119 to Val substitution between the two enzymes to synthesize a PTP-1B inhibitor that is an order of magnitude more selective over TCPTP. Structural analyses of PTP-1B/inhibitor complexes show a conformation-assisted inhibition mechanism as the basis for selectivity. Such an inhibitory mechanism may be applicable to other homologous enzymes.

Synthesis of a novel peptidic photoaffinity probe for the PTP-1B enzyme.

The synthesis of a novel radioactive peptidic photoaffinity probe for the PTP-1B enzyme as well as some SAR leading to the choice of this compound as a photoaffinity probe are presented.

Pyridazinones as selective cyclooxygenase-2 inhibitors.

Pyridazinone was found to be an excellent core template for selective COX-2 inhibitors. Two potent, selective and orally active COX-2 inhibitors, which were highly efficacious in rat paw edema and rat pyresis models, have been obtained.

Structure based design of a series of potent and selective non peptidic PTP-1B inhibitors.

A series of benzotriazole phenyldifluoromethylphosphonic acids were found to be potent PTP-1B inhibitors. Molecular modeling on the X-ray crystal structure of the lead structure led to the design of potent PTP-1B inhibitors that show moderate selectivity against TC-PTP, a very closely related protein tyrosine phosphatase.

The structural basis for the selectivity of benzotriazole inhibitors of PTP1B.

Protein tyrosine phosphatase 1B (PTP1B) has been implicated in the regulation of the insulin signaling pathway and represents an attractive target for the design of inhibitors in the treatment of type 2 diabetes and obesity. Inspection of the structure of PTP1B indicates that potent PTP1B inhibitors may be obtained by targeting a secondary aryl phosphate-binding site as well as the catalytic site. We report here the crystal structures of PTP1B in complex with first and second generation aryldifluoromethyl-phosphonic acid inhibitors. While all compounds bind in a previously unexploited binding pocket near the primary binding site, the second generation compounds also reach into the secondary binding site, and exhibit moderate selectivity for PTP1B over the closely related T-cell phosphatase. The molecular basis for the selectivity has been confirmed by single point mutation at position 52, where the two phosphatases differ by a phenylalanine-to-tyrosine switch. These compounds present a novel platform for the development of potent and selective PTP1B inhibitors.