Structural Basis for Dual-Inhibition Mechanism of a Non-Classical Kazal-Type Serine Protease Inhibitor from Horseshoe Crab in Complex with Subtilisin

Serine proteases play a crucial role in host-pathogen interactions. In the innate immune system of invertebrates, multi-domain protease inhibitors are important for the regulation of host-pathogen interactions and antimicrobial activities. Serine protease inhibitors, 9.3-kDa CrSPI isoforms 1 and 2, have been identified from the hepatopancreas of the horseshoe crab, Carcinoscorpius rotundicauda. The CrSPIs were biochemically active, especially CrSPI-1, which potently inhibited subtilisin (Ki = 1.43 nM). CrSPI has been grouped with the non-classical Kazal-type inhibitors due to its unusual cysteine distribution. Here we report the crystal structure of CrSPI-1 in complex with subtilisin at 2.6 Å resolution and the results of biophysical interaction studies. The CrSPI-1 molecule has two domains arranged in an extended conformation. These two domains act as heads that independently interact with two separate subtilisin molecules, resulting in the inhibition of subtilisin activity at a ratio of 1:2 (inhibitor to protease). Each subtilisin molecule interacts with the reactive site loop from each domain of CrSPI-1 through a standard canonical binding mode and forms a single ternary complex. In addition, we propose the substrate preferences of each domain of CrSPI-1. Domain 2 is specific towards the bacterial protease subtilisin, while domain 1 is likely to interact with the host protease, Furin. Elucidation of the structure of the CrSPI-1: subtilisin (1∶2) ternary complex increases our understanding of host-pathogen interactions in the innate immune system at the molecular level and provides new strategies for immunomodulation

Utilisation des dispositifs à transfert de charges en traitement analogique du signal

Les dispositifs à transfert de charges (DTC) sont des dispositifs analogiques. Qu'ils soient analysés sous forme de ligne à retards ou de registre à décalage, ils constituent une mémoire analogique où sont stockés autant d'échantillons d'un signal, qu'ils comportent d'étages. Leur comportement est à caractériser autant par les concepts classiques analogiques : niveaux de signal et de bruit, distortion, bande passante ; que ceux caractéristiques des mémoires : durée de mémorisation et fréquence de sortie. La technologie de leur réalisation est entièrement compatible avec celle des circuits à transistors MOS. Les circuits que nous présentons, associent DTC et circuits périphériques analogiques. Les résultats obtenus sur cette génération de circuits peuvent se résumé à : . dynamique 60dB . distortion 1/100 . fréquence de transfert maximale 200KHz . bande passante 20KHz . impédance de sortie 10 KΩ. Ces circuits sont des véhicules de test, tant en ce qui concerne le fonctionnement analogique du UTC que de son association avec une circuiterie analogique MOS. A partir de ces résultats préliminaires, nous commençons l'analyse de l'impact de ces concepts de fonctionnement, sur ce que serait le calcul d'une transformée de Fourier, d'un produit de convolution, d'une fonction de corrélation au moyen de dispositifs entièrement intégrés mettant en oeuvre DTC et circuits périphériques à transistors MOS

Optimizing treatment of brain metastases in an era of novel systemic treatments: a single center consecutive series

Background: The multidisciplinary management of patients with brain metastases consists of surgical resection, radiation treatment and systemic treatment. Tailoring and timing these treatment modalities is challenging. This study presents real-world data from consecutively treated patients and assesses the impact of all treatment strategies and their relation with survival. The aim is to provide new insights to improve multidisciplinary decisions towards individualized treatment strategies in patients with brain metastases. Methods: A retrospective consecutive cohort study was performed. Patients with brain metastases were included between June 2018 and May 2020. Brain metastases of small cell lung carcinoma were excluded. Overall survival was analyzed in multivariable models. Results: 676 patients were included in the study, 596 (88%) received radiotherapy, 41 (6%) awaited the effect of newly started or switched systemic treatment and 39 (6%) received best supportive care. Overall survival in the stereotactic radiotherapy group was 14 months (IQR 5–32) and 32 months (IQR 11–43) in patients who started or switched systemic treatment and initially did not receive radiotherapy. In patients with brain metastases without options for local or systemic treatment best supportive care was provided, these patients had an overall survival of 0 months (IQR 0–1). Options for systemic treatment, Karnofsky Performance Score ≥ 70 and breast cancer were prognostic for a longer overall survival, while progressive extracranial metastases and whole-brain-radiotherapy were prognostic for shorter overall survival. Conclusions: Assessing prognosis in light of systemic treatment options is crucial after the diagnosis of brain metastasis for the consideration of radiotherapy versus best supportive care. Graphical Abstract: [Figure not available: see fulltext.

Performance analysis of a dedicated breast MR-HIFU system for tumor ablation in breast cancer patients

MR-guided HIFU ablation is a promising technique for the non-invasive treatment of breast cancer. A phase I study was performed to assess the safety and treatment accuracy and precision of MR-HIFU ablation in breast cancer patients (n = 10) using a newly developed MR-HIFU platform dedicated to applications in the breast. In this paper a technical analysis of the performance of the dedicated breast MR-HIFU system during breast tumors ablation is described. The main points of investigation were the spatial targeting accuracy and precision of the system and the performance of real-time respiration-corrected MR thermometry. The mean targeting accuracy was in the range of 2.4-2.6 mm, whereas the mean targeting precision was in the range of 1.5-1.8 mm. To correct for respiration-induced magnetic field fluctuations during MR temperature mapping a look-up-table (LUT)-based correction method was used. An optimized procedural sedation protocol in combination with the LUT-based correction method allowed for precise MR thermometry during the ablation procedure (temperature standard deviatio

A model for the Mullins effect during multicyclic equibiaxial loading

In this paper, we derive a model to describe the cyclic stress softening of a carbon-filled rubber vulcanizate through multiple stress–strain cycles with increasing values of the maximum strain, specializing to equibiaxial loading. Since the carbon-filled rubber vulcanizate is initially isotropic, we can show that following initial equibiaxial loading the material becomes transversely isotropic with preferred direction orthogonal to the plane defined by the equibiaxial loading. This is an example of strain-induced anisotropy. Accordingly, we derive nonlinear transversely isotropic models for the elastic response, stress relaxation, residual strain and creep of residual strain in order to model accurately the inelastic features associated with cyclic stress softening. These ideas are then combined with a transversely isotropic version of the Arruda–Boyce eight-chain model to develop a constitutive relation for the cyclic stress softening of a carbon-filled rubber vulcanizate. The model developed includes the effects of hysteresis, stress relaxation, residual strain and creep of residual strain. The model is found to compare extremely well with experimental data