Mechanistic Characterisation of Collinodiene Synthase, a Diterpene Synthase from Streptomyces collinus.

Two homologs of the diterpene synthase CotB2 from Streptomyces collinus (ScCotB2) and Streptomyces iakyrus (SiCotB2) were investigated for their products by in vitro incubations of the recombinant enzymes with geranylgeranyl pyrophosphate, followed by compound isolation and structure elucidation by NMR. ScCotB2 produced the new compound collinodiene, besides the canonical CotB2 product cyclooctat-9-en-7-ol, dolabella-3,7,18-triene and dolabella-3,7,12-triene, while SiCotB2 gave mainly cyclooctat-9-en-7-ol and only traces of dolabella-3,7,18-triene. The cyclisation mechanism towards the ScCotB2 products and their absolute configurations were investigated through isotopic labelling experiments.

Concerning the photophysics of fluorophores towards tailored bioimaging compounds: a case study involving S100A9 inflammation markers.

A full understanding concerning the photophysical properties of a fluorescent label is crucial for a reliable and predictable performance in biolabelling applications. This holds true not only for the choice of a fluorophore in general, but also for the correct interpretation of data, considering the complexity of biological environments. In the frame of a case study involving inflammation imaging, we report the photophysical characterization of four fluorescent S100A9-targeting compounds in terms of UV-vis absorption and photoluminescence spectroscopy, fluorescence quantum yields (ΦF) and excited state lifetimes (τ) as well as the evaluation of the radiative and non-radiative rate constants (kr and knr, respectively). The probes were synthesized based on a 2-amino benzimidazole-based lead structure in combination with commercially available dyes, covering a broad color range from green (6-FAM) over orange (BODIPY-TMR) to red (BODIPY-TR) and near-infrared (Cy5.5) emission. The effect of conjugation with the targeting structure was addressed by comparison of the probes with their corresponding dye-azide precursors. Additionally, the 6-FAM and Cy5.5 probes were measured in the presence of murine S100A9 to determine whether protein binding influences their photophysical properties. An interesting rise in ΦF upon binding of 6-FAM-SST177 to murine S100A9 enabled the determination of its dissociation equilibrium constant, reaching up to KD = 324 nM. This result gives an outlook for potential applications of our compounds in S100A9 inflammation imaging and fluorescence assay developments. With respect to the other dyes, this study demonstrates how diverse microenvironmental factors can severely impair their performance while rendering them poor performers in biological media, showing that a preliminary photophysical screening is key to assess the suitability of a particular luminophore.

Conjugated Pt(II) Complexes as Luminescence-Switch-On Reporters Addressing the Microenvironment of Bacterial Biofilms.

In this work, the synthesis, structural and photophysical characterization of six phosphorescent H2O-soluble Pt(II) complexes are reported while addressing their emission maxima, photoluminescence quantum yields (ΦL), lifetimes (τ), aggregation tendency, and microenvironment sensitivity as a function of the substitution pattern on the main tridentate luminophore. Different ancillary ligands, namely, a trisulfonated phosphane and maltohexaose-conjugated pyridines (with or without amide bridges), were introduced and evaluated for the realization of switch-on-photoluminescent labels reporting on the microenvironment sensed in biofilms of Gram+ and Gram- models, namely, Staphylococcus aureus and Escherichia coli. With the aid of confocal luminescence micro(spectro)scopy, we observed that selected complexes specifically interact with the biofilms while leaving planktonic cells unlabeled. By using photoluminescence lifetime imaging microscopy, excited-state lifetimes within S. aureus biofilms were measured. The photoluminescence intensities were drastically boosted, and the excited state lifetimes were significantly prolonged upon binding to the viscous biofilm matrix, mainly due to the suppression of radiationless deactivation pathways upon shielding from physical quenching processes, such as interactions with solvent molecules and 3O2. The best performances were attained for non-aggregating complexes with maltohexaose targeting units and without amide bridges. Notably, in the absence of the maltodextrin, a hydrophobic adamantyl moiety suffices to attain a sizeable labeling capacity. Moreover, photoluminescence studies showed that selected complexes can also effectively interact with E. coli biofilms, where the bacterial cells are able to partially uptake the maltodextrin-based agents. In summary, the herein introduced concepts enable the development of specific biofilm reporters providing spatial resolution as well as lifetime- and spectrum-based readouts. Considering that most theragnostic agents reported so far mainly address metabolically active bacteria at the surface of biofilms but without reaching cells deeply immersed in the matrix, a new platform with a clear structure-property correlation is provided for the early detection of such bacterial arrays.

The effect of visual feedback on people suffering from chronic back and neck pain - a systematic review.

Objectives: Visual feedback as an intervention for people suffering from chronic back or chronic neck pain is a novel approach based on the person's perception of the painful body part. Visual feedback is an innovative therapeutic approach whose effects have not yet been systematically reviewed specifically for people with chronic back or chronic neck pain. Therefore, a systematic review was performed on the literature to evaluate the effects of visual feedback on pain intensity in people with chronic back or neck pain. Methods: This systematic review investigated the magnitude and clinical relevance of the reported effects, as well as the reporting quality of the included studies. Pain intensity was defined as the outcome of interest to judge the clinical relevance of the findings. The quality of reporting and the risk of bias were assessed. Results: The original search revealed 359 studies of which five were included following screening of the title and abstract, application of the inclusion/exclusion criteria and reading the full texts. All five studies had investigated chronic back pain. Most studies showed either a momentary decrease of pain intensity during the application of a visual feedback method or a habitual decrease after treatment for 2 weeks. Discussion: While visual feedback does appear to alter pain intensity in people with chronic back pain, there is limited evidence from these studies to support visual feedback as an adjunct to therapy. These issues point out that future studies may be indicated.

A Family of Related Fungal and Bacterial Di- and Sesterterpenes: Studies on Fusaterpenol and Variediene.

The absolute configuration of fusaterpenol (GJ1012E) has been revised by an enantioselective deuteration strategy. A bifunctional enzyme with a terpene synthase and a prenyltransferase domain from Aspergillus brasiliensis was characterised as variediene synthase, and the absolute configuration of its product was elucidated. The uniform absolute configurations of these and structurally related di- and sesterterpenes together with a common stereochemical course for the geminal methyl groups of GGPP unravel a similar conformational fold of the substrate in the active sites of the terpene synthases. For variediene, a thermal reaction observed during GC/MS analysis was studied in detail for which a surprising mechanism was uncovered.

Diterpene Biosynthesis in Actinomycetes: Studies on Cattleyene Synthase and Phomopsene Synthase.

Three diterpene synthases from actinomycetes have been studied. The first enzyme from Streptomyces cattleya produced the novel compound cattleyene. The other two enzymes from Nocardia testacea and Nocardia rhamnosiphila were identified as phomopsene synthases. The cyclisation mechanism of cattleyene synthase and the EIMS fragmentation mechanism of its product were extensively studied by incubation experiments with isotopically labelled precursors. Oxidative transformations expanded the chemical space of these unique diterpenes.

Excessive alcohol consumption in young men: is there an association with their earlier family situation? A baseline-analysis of the C-SURF-study (Cohort Study on Substance Use Risk Factors).

AIMS: To determine whether parental factors earlier in life (parenting, single parent family, parental substance use problem) are associated with patterns of alcohol consumption among young men in Switzerland. METHODS: This analysis of a population based sample from the Cohort Study on Substance Use Risk Factors (C-SURF) included 5,990 young men (mean age 19.51 years), all attending a mandatory recruitment process for the army. These conscripts reported on parental monitoring and rule-setting, parental behaviour and family structure. The alcohol use pattern was assessed through abstention, risky single occasion drinking (RSOD), volume drinking and dependence. Furthermore, the impact of age, family socio-economic status, educational level of the parents, language region and civil status was analysed. RESULTS: A parental substance use problem was positively associated with volume drinking and alcohol dependence in young Swiss men. Active parenting corresponded negatively with RSOD, volume drinking and alcohol dependence. Single parent family was not associated with a different alcohol consumption pattern compared to standard family. CONCLUSION: Parental influences earlier in life such as active parenting (monitoring, rule-setting and knowing the whereabouts) and perceived parental substance use problem are associated with alcohol drinking behaviour in young male adults. Therefore, health professionals should stress the importance of active parenting and parental substance use prevention in alcohol prevention strategies.

[There is something amiss]. / Neuromuskuläre Irrwege.

We report the case of a 54-year old man with slowly progressive symmetrical weakness of the proximal legs and atactic gait. The diagnostic work-up is reviewed. It revealed the diagnosis of a Lambert-Eaton myasthenic syndrome(LEMS) and SIADH caused by a small cell lung cancer (SCLC).

Betablockers in heart failure: Carvedilol Safety Assessment (CASA 2-trial).

BACKGROUND: Betablockers are a cornerstone in the treatment of patients with chronic heart failure (CHF). The purpose of the present study was to assess safety and tolerability of carvedilol in CHF-patients. METHODS: 66 general practitioners, who were supervised by a local cardiologist, enrolled 151 CHF-patients. All patients were on standard therapy with ACE-inhibitors and diuretics. Carvedilol treatment was started with 3.125 mg twice daily and slowly uptitrated in 2-week intervals to 2x25 mg per day. Mean follow-up was 12 weeks. RESULTS: 145 of the 151 patients (96%) finished the study according to protocol, six patients were lost to follow-up (4%). 59 patients (41%) experienced minor and nine (6%) serious adverse events. 68 were under maximal therapy with 50 mg daily, 33 received 25 mg, and 15 12.5 mg. Overall tolerability was good and NYHA-class fell significantly from 2.2 to 1.8 (P<0.001). Mean heart rate decreased from 78 to 69 bpm (P<0.001), mean systolic blood pressure from 137 to 132 mmHg (P<0.001) and mean diastolic blood pressure from 80 to 76 mmHg (P<0.001). Quality of life significantly improved under carvedilol with a reduction in the Minnesota living with heart failure score from 1.28 to 0.88 (P<0.001). CONCLUSIONS: Carvedilol is well tolerated in CHF-patients treated by general practitioners. Serious adverse events and hospitalisations are rare. Thus, carvedilol is a safe drug in the treatment of CHF-patients and can be easily initiated and managed by the general practitioner.