Antibody-Mediated Neutralization of the Exotoxin Mycolactone, the Main Virulence Factor Produced by Mycobacterium ulcerans

Mycolactone, the macrolide exotoxin produced by Mycobacterium ulcerans, causes extensive tissue destruction by inducing apoptosis of host cells. In this study, we aimed at the production of antibodies that could neutralize the cytotoxic activities of mycolactone.; Using the B cell hybridoma technology, we generated a series of monoclonal antibodies with specificity for mycolactone from spleen cells of mice immunized with the protein conjugate of a truncated synthetic mycolactone derivative. L929 fibroblasts were used as a model system to investigate whether these antibodies can inhibit the biological effects of mycolactone. By measuring the metabolic activity of the fibroblasts, we found that anti-mycolactone mAbs can completely neutralize the cytotoxic activity of mycolactone.; The toxin neutralizing capacity of anti-mycolactone mAbs supports the concept of evaluating the macrolide toxin as vaccine target

Comparative effectiveness of initial computed tomography and invasive coronary angiography in women and men with stable chest pain and suspected coronary artery disease: multicentre randomised trial

To assess the comparative effectiveness of computed tomography and invasive coronary angiography in women and men with stable chest pain suspected to be caused by coronary artery disease

SPR-based fragment screening with neurotensin receptor 1 generates novel small molecule ligands

The neurotensin receptor 1 represents an important drug target involved in various diseases of the central nervous system. So far, the full exploitation of potential therapeutic activities has been compromised by the lack of compounds with favorable physicochemical and pharmacokinetic properties which efficiently penetrate the blood-brain barrier. Recent progress in the generation of stabilized variants of solubilized neurotensin receptor 1 and its subsequent purification and successful structure determination presents a solid starting point to apply the approach of fragment-based screening to extend the chemical space of known neurotensin receptor 1 ligands. In this report, surface plasmon resonance was used as primary method to screen 6369 compounds. Thereby 44 hits were identified and confirmed in competition as well as dose-response experiments. Furthermore, 4 out of 8 selected hits were validated using nuclear magnetic resonance spectroscopy as orthogonal biophysical method. Computational analysis of the compound structures, taking the known crystal structure of the endogenous peptide agonist into consideration, gave insight into the potential fragment-binding location and interactions and inspires chemistry efforts for further exploration of the fragments

Diagnosis of whooping cough in Switzerland: differentiating Bordetella pertussis from Bordetella holmesii by polymerase chain reaction.

Bordetella holmesii, an emerging pathogen, can be misidentified as Bordetella pertussis by routine polymerase chain reaction (PCR). In some reports, up to 29% of the patients diagnosed with pertussis have in fact B. holmesii infection and invasive, non-respiratory B. holmesii infections have been reported worldwide. This misdiagnosis undermines the knowledge of pertussis' epidemiology, and may lead to misconceptions on pertussis vaccine's efficacy. Recently, the number of whooping cough cases has increased significantly in several countries. The aim of this retrospective study was to determine whether B. holmesii was contributing to the increase in laboratory-confirmed cases of B. pertussis in Switzerland. A multiplex species-specific quantitative PCR assay was performed on 196 nasopharyngeal samples from Swiss patients with PCR-confirmed Bordetella infection (median age: 6 years-old, minimum 21 days-old, maximum 86 years-old), formerly diagnosed as Bordetella pertussis (IS481+). No B. holmesii (IS481+, IS1001-, hIS1001+) was identified. We discuss whether laboratories should implement specific PCR to recognize different Bordetella species. We conclude that in Switzerland B. holmesii seems to be circulating less than in neighboring countries and that specific diagnostic procedures are not necessary routinely. However, as the epidemiological situation may change rapidly, periodic reevaluation is suggested

[Enfants et adolescents avec variations du développement sexuel]

Wie werden heute Kinder mit unklarem Geschlecht in der Schweiz betreut? Diese und ähnliche Fragen beschäftigen nicht nur Spezialist(inn)en und Betroffene, sondern auch die Öffentlichkeit. Die Nationale Ethikkommission hat 2012 Empfehlungen zum Umgang mit Menschen mit Varianten der Geschlechtsentwicklung erarbeitet.Comment les enfants de sexe indéterminé sont-ils aujourd’hui pris en charge en Suisse? Cette question et des questions similaires préoccupent non seulement les spécialistes et les personnes touchées, mais également la société en général. En 2012, la Commission nationale d’éthique dans le domaine de la médecine humaine a élaboré des recommandations relatives à l’attitude à adopter à l’égard des personnes avec variations du développement sexuel

Overlay of binding curves (red) monitored by titration experiments of neurotensin peptides (NT_8-13, NT_8-13A₁₁, and NT_8-13A_11,12) on the NTS1-H4 surface with low receptor density and mathematically calculated curves for a one-to-one interaction binding model (black).

<p>(A) Binding curves for neurotensin peptides NT_8-13 titrated up to 25 nM in a single cycle kinetic experiment (dilution factor 2); (B) and (C) Binding curves for NT_8-13A₁₁, and NT_8-13A_11,12 titrated up to 100 or 500 nM in multiple cycle kinetic experiments (dilution factor 2), respectively.</p

NMR control experiments and binding data for fragment 2 measured with purified NTS1-H4 receptor.

<p>The affinity of fragments for L-MNG detergent used for the solubilization of NTS1-H4 was tested in preliminary experiments. The 1D ¹H aromatic spectrum of 10 μM fragment is shown in buffer without L-MNG detergent (green), in buffer with 0.01% L-MNG (blue), and in buffer with 0.01% L-MNG and 5 μM NTS1-H4 (red). All tested fragments showed no affinity for L-MNG detergent micelles, and the observed line broadening effect upon protein addition indeed originates from the interaction between fragment and NTS1-H4. (B) Overlay of fragment 2 1D ¹H NMR spectra that reflect a titration series up to 150 μM (10 (black), 20 (grey), 30 (orange), 40 (red), 60 (cyan), 100 (green) and 150 (blue) μM). (C) The interactive curve fitting program XLfit was used to determine K_D values from subtle chemical shift differences observed in 1D ¹H NMR spectra.</p

SPR screening workflow of the Roche fragment library on the thermostabilized NTS1 receptor NTS1-H4 and subsequent hit validation by NMR.

<p>SPR screening workflow of the Roche fragment library on the thermostabilized NTS1 receptor NTS1-H4 and subsequent hit validation by NMR.</p