Degradation of chloroaromatics: structure and catalytic activities of wild-type chlorocatechol 2,3-dioxygenases and modified ones.

To improve the efficiency and to investigate the molecular determinants that direct substrate specificity of chlorocatechol 2,3-dioxygenase CbzE(GJ31) , several mutant enzymes were constructed. Loci for substitutions of amino acids were selected by sequence comparisons as well as by homology modelling of known chlorocatechol 2,3-dioxygenases (CbzE(BASF) , CbzE(SK1) and CbzE(16-6A)). Activity measurements with various catechols showed that most of the modifications influenced activity only to a minor degree.

Novel dehalogenase mechanism for 2,3-dichloro-1-propanol utilization in Pseudomonas putida strain MC4.

A Pseudomonas putida strain (MC4) that can utilize 2,3-dichloro-1-propanol (DCP) and several aliphatic haloacids and haloalcohols as sole carbon and energy source for growth was isolated from contaminated soil. Degradation of DCP was found to start with oxidation and concomitant dehalogenation catalyzed by a 72-kDa monomeric protein (DppA) that was isolated from cell lysate. The dppA gene was cloned from a cosmid library and appeared to encode a protein equipped with a signal peptide and that possessed high similarity to quinohemoprotein alcohol dehydrogenases (ADHs), particularly ADH IIB and ADH IIG from Pseudomonas putida HK.

Structural determinants of the β-selectivity of a bacterial aminotransferase.

Chiral β-amino acids occur as constituents of various natural and synthetic compounds with potentially useful bioactivities. The pyridoxal 5'-phosphate (PLP)-dependent S-selective transaminase from Mesorhizobium sp. strain LUK (MesAT) is a fold type I aminotransferase that can be used for the preparation of enantiopure β-Phe and derivatives thereof.

Interface micromechanics of transverse sections from retrieved cemented hip reconstructions: an experimental and finite element comparison.

In finite element analysis (FEA) models of cemented hip reconstructions, it is crucial to include the cement-bone interface mechanics. Recently, a micromechanical cohesive model was generated which reproduces the behavior of the cement-bone interface. The goal was to investigate whether this cohesive model was directly applicable on a macro level.

Experience of pre-hospital treatment of survivors of falls-related trauma by an Australian helicopter emergency medical service.

Background: Greater Sydney Area Helicopter Emergency Medical Service (GSA-HEMS) operates a doctor and paramedic team providing pre-hospital and inter-hospital retrieval. Falls are an important cause of morbidity and mortality among trauma patients. In NSW, patients injured by falling comprise 38% of those with serious to critical injuries (ISS>15).

Engineering methylaspartate ammonia lyase for the asymmetric synthesis of unnatural amino acids.

The redesign of enzymes to produce catalysts for a predefined transformation remains a major challenge in protein engineering. Here, we describe the structure-based engineering of methylaspartate ammonia lyase (which in nature catalyses the conversion of 3-methylaspartate to ammonia and 2-methylfumarate) to accept a variety of substituted amines and fumarates and catalyse the asymmetric synthesis of aspartic acid derivatives. We obtained two single-active-site mutants, one exhibiting a wide nucleophile scope including structurally diverse linear and cyclic alkylamines and one with broad electrophile scope including fumarate derivatives with alkyl, aryl, alkoxy, aryloxy, alkylthio and arylthio substituents at the C2 position.

On stabilization of loosened hip stems via cement injection into osteolytic cavities.

Background: Cement injection into osteolytic areas around the cement mantle is a technique for refixation of loose hip implants for patients who cannot undergo standard revision surgery. Preliminary clinical results show the improvement in walking distance, patients' independence and pain relief.

Methods: In this study, we use a detailed finite element model to analyze whether cement injection into osteolytic areas contributes to the overall implant stability.

Symptom distress in advanced chronic organ failure: disagreement among patients and family caregivers.

Background: Proxy reporting is frequently used to assess symptom distress of patients with advanced chronic organ failure. The aim of the present cross-sectional study was to examine agreement in severity of symptom distress, presence of symptom-related interventions, and satisfaction with medical treatment among patients with advanced chronic obstructive pulmonary disease (COPD), chronic heart failure (CHF) and chronic renal failure (CRF) and their family caregivers.

Methods: Outpatients with advanced COPD (n=73), CHF (n=45) and CRF (n=41) and their family caregivers rated severity of physical and psychological symptoms experienced by the patient using Visual Analogue Scales (VAS).

Complete nucleotide sequence of a severe isolate of cucumber vein yellowing virus from Jordan.

The complete genome of a severe isolate of Cucumber vein yellowing virus (CVYV) from Jordan was sequenced. Comparison with the genome of a Spanish CVYV isolate inducing very mild symptoms in cucumber cultivars revealed a nucleotide identity of 94% for the complete genome and an amino acid identity of 96% for the coding region. Comparison of synonymous and non-synonymous substitutions suggested a negative selection at amino acid and nucleotide levels with different degrees depending on the different coding regions.

A new approach to quantify trabecular resorption adjacent to cemented knee arthroplasty.

A new micro-computed tomography (μCT) image processing approach to estimate the loss of cement-bone interlock was developed using the concept that PMMA cement flows and cures around trabeculae during the total knee arthroplasty procedure. The initial mold shape of PMMA cement was used to estimate the amount of interdigitated bone at the time of implantation and following in vivo service using enbloc human postmortem retrievals. Laboratory prepared specimens, where there would be no biological bone resorption, were used as controls to validate the approach and estimate errors.

Toward a more realistic prediction of peri-prosthetic micromotions.

The finite element (FE) method has become a common tool to evaluate peri-prosthetic micromotions in cementless total hip arthroplasty. Often, only the peak joint load and a selected number of muscle loads are applied to determine micromotions. Furthermore, the applied external constraints are simplified (diaphyseal fixation), resulting in a non-physiological situation.

Mechanism-inspired engineering of phenylalanine aminomutase for enhanced β-regioselective asymmetric amination of cinnamates.

Turn to switch: A mutant of phenylalanine aminomutase was engineered that can catalyze the regioselective amination of cinnamate derivatives (see scheme, red) to, for example, β-amino acids. This regioselectivity, along with the X-ray crystal structures, suggests two distinct carboxylate binding modes differentiated by C(β)-C(ipso) bond rotation, which determines if β- (see scheme) or α-addition takes place.

Directed evolution strategies for enantiocomplementary haloalkane dehalogenases: from chemical waste to enantiopure building blocks.

We used directed evolution to obtain enantiocomplementary haloalkane dehalogenase variants that convert the toxic waste compound 1,2,3-trichloropropane (TCP) into highly enantioenriched (R)- or (S)-2,3-dichloropropan-1-ol, which can easily be converted into optically active epichlorohydrins-attractive intermediates for the synthesis of enantiopure fine chemicals. A dehalogenase with improved catalytic activity but very low enantioselectivity was used as the starting point. A strategy that made optimal use of the limited capacity of the screening assay, which was based on chiral gas chromatography, was developed.

Isolation and characterization of a Rhodococcus strain able to degrade 2-fluorophenol.

A pure bacterial culture able to utilize 2-fluorophenol (2-FP) as sole carbon and energy source was isolated by selective enrichment from sediments collected from a contaminated site in Northern Portugal. 16S rRNA gene analysis showed that the organism (strain FP1) belongs to the genus Rhodococcus. When grown aerobically on 2-FP, growth kinetics of strain FP1 followed the Luong model.

Predicting changes in preferences for life-sustaining treatment among patients with advanced chronic organ failure.

Background: For physicians discussing advance care planning with patients with life-limiting illness, it is important to understand the stability of the patients' preferences for life-sustaining treatments and the factors that predict a change in preferences. Our objectives were to investigate 1-year stability of preferences regarding CPR and mechanical ventilation (MV) for outpatients with advanced COPD, chronic heart failure (CHF), or chronic renal failure (CRF) and to identify predictors of changes in preferences.

Methods: In this study, 265 clinically stable outpatients with advanced COPD, CHF, or CRF were visited at baseline and every 4 months for 1 year to assess preferences regarding CPR and MV in their current health status.

Advance care planning in COPD.

The review aims to discuss current concepts in advance care planning (ACP) for patients with COPD, and to provide a narrative review of recent trends in ACP and end-of-life care for patients with COPD. ACP, which involves patient-clinician communication about end-of-life care, can improve outcomes for patients and their families, and may be especially relevant for patients with COPD. Effective patient-clinician communication is needed to inform and prepare patients about their diagnosis, treatment, prognosis and what dying might be like.

Characterization of a thermostable methylaspartate ammonia lyase from Carboxydothermus hydrogenoformans.

Methylaspartate ammonia lyase (MAL; EC 4.3.1.

Yellowing disease in zucchini squash produced by mixed infections of Cucurbit yellow stunting disorder virus and Cucumber vein yellowing virus.

Zucchini squash is host to Cucurbit yellow stunting disorder virus (CYSDV), a member of the genus Crinivirus, and Cucumber vein yellowing virus (CVYV), a member of the genus Ipomovirus, both transmitted by the whitefly Bemisia tabaci. Field observations suggest the appearance of new symptoms observed on leaves of zucchini squash crops when both viruses were present. When infected during controlled experiments with CYSDV only, zucchini plants showed no obvious symptoms and the virus titer decreased between 15 and 45 days postinoculation (dpi), after which it was no longer detected.

Effect of cementing technique and cement type on thermal necrosis in hip resurfacing arthroplasty--a numerical study.

Femoral fractures within resurfacing implants have been associated with bone necrosis, possibly resulting from heat generated by cement polymerization. The amount of heat generated depends on cement mantle volume and type of cement. Using finite element analysis, the effect of cement type and volume on thermal necrosis was analyzed.

Twice random, once mixed: applying mixed models to simultaneously analyze random effects of language and participants.

Psychologists, psycholinguists, and other researchers using language stimuli have been struggling for more than 30 years with the problem of how to analyze experimental data that contain two crossed random effects (items and participants). The classical analysis of variance does not apply; alternatives have been proposed but have failed to catch on, and a statistically unsatisfactory procedure of using two approximations (known as F(1) and F(2)) has become the standard. A simple and elegant solution using mixed model analysis has been available for 15 years, and recent improvements in statistical software have made mixed models analysis widely available.

The effect of bone ingrowth depth on the tensile and shear strength of the implant-bone e-beam produced interface.

New technologies, such as selective electron beam melting, allow to create complex interface structures to enhance bone ingrowth in cementless implants. The efficacy of such structures can be tested in animal experiments. Although animal studies provide insight into the biological response of new structures, it remains unclear how ingrowth depth is related to interface strength.

Out-of-theatre tracheal intubation: prospective multicentre study of clinical practice and adverse events.

Background: Tracheal intubation is commonly performed outside the operating theatre and is associated with higher risk than intubation in theatre. Recent guidelines and publications including the 4th National Audit Project of the Royal College of Anaesthetists have sought to improve the safety of out-of-theatre intubations.

Methods: We performed a prospective observational study examining all tracheal intubations occurring outside the operating theatre in nine hospitals over a 1 month period.

The mechanoreceptor TRPV4 is localized in adherence junctions of the human bladder urothelium: a morphological study.

Purpose: TRPV4 (transient receptor potential vanilloid 4 channel) is a nonselective cation channel involved in different sensory functions that was recently implicated in bladder mechanosensation. We investigated the cellular site of TRPV4 in bladder urothelium and explored a molecular connection between TRPV4 and urothelial adherence junctions.

Materials And Methods: We obtained healthy tissues sections from cystectomy in humans due to cancer in 3 and noncancerous conditions in 2.

Morphology based cohesive zone modeling of the cement-bone interface from postmortem retrievals.

In cemented total hip arthroplasty, the cement-bone interface can be considerably degenerated after less than one year in vivo service; this makes the interface much weaker relative to the direct post-operative situation. It is, however, still unknown how these degenerated interfaces behave under mixed-mode loading and how this is related to the interface morphology. In this study, we used a finite element (FE) approach to analyze the mixed-mode response of the cement-bone interface taken from postmortem retrievals.