Purification and characterization of Cdr1, the drug-efflux pump conferring azole resistance in Candida species.

Candida albicans and C. glabrata express exporters of the ATP-binding cassette (ABC) superfamily and address them to their plasma membrane to expel azole antifungals, which cancels out their action and allows the yeast to become multidrug resistant (MDR). In a way to understand this mechanism of defense, we describe the purification and characterization of Cdr1, the membrane ABC exporter mainly responsible for such phenotype in both species.

[Management of tubal ectopic pregnancies with methotrexate : is it an effective treatment ?].

Ectopic pregnancy is a gynecological emergency. The hCG level, the clinical presentation and the ultrasound remain the key steps for the diagnosis. The criteria tend to be more and more codified to decide on the optimal treatment, however, there is no consensus.

Molecular elucidation of drug-induced abnormal assemblies of the hepatitis B virus capsid protein by solid-state NMR.

Hepatitis B virus (HBV) capsid assembly modulators (CAMs) represent a recent class of anti-HBV antivirals. CAMs disturb proper nucleocapsid assembly, by inducing formation of either aberrant assemblies (CAM-A) or of apparently normal but genome-less empty capsids (CAM-E). Classical structural approaches have revealed the CAM binding sites on the capsid protein (Cp), but conformational information on the CAM-induced off-path aberrant assemblies is lacking.

Pharmacomodulation of a ligand targeting the HBV capsid hydrophobic pocket.

Hepatitis B virus (HBV) is a small enveloped retrotranscribing DNA virus and an important human pathogen. Its capsid-forming core protein (Cp) features a hydrophobic pocket proposed to be central notably in capsid envelopment. Indeed, mutations in and around this pocket can profoundly modulate, and even abolish, secretion of enveloped virions.

Fast Magic-Angle-Spinning NMR Reveals the Evasive Hepatitis B Virus Capsid C-Terminal Domain.

Experimentally determined protein structures often feature missing domains. One example is the C-terminal domain (CTD) of the hepatitis B virus capsid protein, a functionally central part of this assembly, crucial in regulating nucleic-acid interactions, cellular trafficking, nuclear import, particle assembly and maturation. However, its structure remained elusive to all current techniques, including NMR.

Large-Scale Recombinant Production of the SARS-CoV-2 Proteome for High-Throughput and Structural Biology Applications.

The highly infectious disease COVID-19 caused by the SARS-CoV-2 poses a severe threat to humanity and demands the redirection of scientific efforts and criteria to organized research projects. The international consortium seeks to provide such new approaches by gathering scientific expertise worldwide. In particular, making available viral proteins and RNAs will pave the way to understanding the SARS-CoV-2 molecular components in detail.

A pocket-factor-triggered conformational switch in the hepatitis B virus capsid.

Viral hepatitis is growing into an epidemic illness, and it is urgent to neutralize the main culprit, hepatitis B virus (HBV), a small-enveloped retrotranscribing DNA virus. An intriguing observation in HB virion morphogenesis is that capsids with immature genomes are rarely enveloped and secreted. This prompted, in 1982, the postulate that a regulated conformation switch in the capsid triggers envelopment.

Combining Cell-Free Protein Synthesis and NMR Into a Tool to Study Capsid Assembly Modulation.

Modulation of capsid assembly by small molecules has become a central concept in the fight against viral infection. Proper capsid assembly is crucial to form the high molecular weight structures that protect the viral genome and that, often in concert with the envelope, allow for cell entry and fusion. Atomic details underlying assembly modulation are generally studied using preassembled protein complexes, while the activity of assembly modulators during assembly remains largely open and poorly understood, as necessary tools are lacking.

Cyclophilin A allows the allosteric regulation of a structural motif in the disordered domain 2 of NS5A and thereby fine-tunes HCV RNA replication.

Implicated in numerous human diseases, intrinsically disordered proteins (IDPs) are dynamic ensembles of interconverting conformers that often contain many proline residues. Whether and how proline conformation regulates the functional aspects of IDPs remains an open question, however. Here, we studied the disordered domain 2 of nonstructural protein 5A (NS5A-D2) of hepatitis C virus (HCV).

Retrospective study of pneumonia due to Panton-Valentine leukocidin-producing Staphylococcus aureus in Reunion.

Objective: Panton-Valentine leukocidin-producing Staphylococcus aureus necrotizing pneumonia is an unusual cause of community-acquired pneumonia, although associated with a high case fatality. This infection mainly affects young individuals, without any history, and is most often preceded by flu-like symptoms.

Method: We focused on patients presenting with Staphylococcus aureus necrotizing pneumonia in Reunion (Indian Ocean) admitted to the emergency department.

X-ray structure of alisporivir in complex with cyclophilin A at 1.5 Å resolution.

Alisporivir (ALV) is an 11-amino-acid hydrophobic cyclic peptide with N-methyl-D-alanine and N-ethyl-L-valine (NEV) residues at positions 3 and 4, respectively. ALV is a non-immunosuppressive cyclosporin A (CsA) derivative. This inhibitor targets cyclophilins (Cyps), a family of proteins with peptidyl-prolyl cis/trans isomerase enzymatic activity.

Interaction study between HCV NS5A-D2 and NS5B using F NMR.

The non structural protein 5A (NS5A) regulates the replication of the hepatitis C viral RNA through a direct molecular interaction of its domain 2 (NS5A-D2) with the RNA dependent RNA polymerase NS5B. Because of conflicting data in the literature, we study here this molecular interaction using fluorinated versions of the NS5A-D2 protein derived from the JFH1 Hepatitis C Virus strain. Two methods to prepare fluorine-labelled NS5A-D2 involving the biosynthetic incorporation of a F-tryptophan using 5-fluoroindole and the posttranslational introduction of fluorine by chemical conjugation of 2-iodo-N-(trifluoromethyl)acetamide with the NS5A-D2 cysteine side chains are presented.

Crystal Structure of the Full-Length Feline Immunodeficiency Virus Capsid Protein Shows an N-Terminal β-Hairpin in the Absence of N-Terminal Proline.

Feline immunodeficiency virus (FIV) is a member of the Retroviridae family. It is the causative agent of an acquired immunodeficiency syndrome (AIDS) in cats and wild felines. Its capsid protein (CA) drives the assembly of the viral particle, which is a critical step in the viral replication cycle.

NMR reveals the intrinsically disordered domain 2 of NS5A protein as an allosteric regulator of the hepatitis C virus RNA polymerase NS5B.

Non-structural protein 5B (NS5B) is the RNA-dependent RNA polymerase that catalyzes replication of the hepatitis C virus (HCV) RNA genome and therefore is central for its life cycle. NS5B interacts with the intrinsically disordered domain 2 of NS5A (NS5A-D2), another essential multifunctional HCV protein that is required for RNA replication. As a result, these two proteins represent important targets for anti-HCV chemotherapies.

A Proline-Tryptophan Turn in the Intrinsically Disordered Domain 2 of NS5A Protein Is Essential for Hepatitis C Virus RNA Replication.

Hepatitis C virus (HCV) nonstructural protein 5A (NS5A) and its interaction with the human chaperone cyclophilin A are both targets for highly potent and promising antiviral drugs that are in the late stages of clinical development. Despite its high interest in regards to the development of drugs to counteract the worldwide HCV burden, NS5A is still an enigmatic multifunctional protein poorly characterized at the molecular level. NS5A is required for HCV RNA replication and is involved in viral particle formation and regulation of host pathways.

Struma ovarii: role of imaging?

As clinical features in struma ovarii patients in the absence of thyrotoxicosis are generally non-specific and resemble ovarian malignancy, preoperative radiological diagnosis becomes all the more relevant in order to avoid ovarian cancer type surgery (including bilateral salpingo-oophorectomy, hysterectomy, omentectomy and occasionally appendectomy) for this usually benign and rare ovarian mass. As struma ovarii is an uncommon entity, it is all the more important to perform state-of-the-art magnetic resonance (MR) imaging, including high-resolution imaging and diffusion-weighted imaging. The goal of this review paper is to give an update of the key findings of both benign and malignant struma ovarii and to present an unusual case of a purely cystic ovarian struma.

Magnetic resonance imaging findings in cardiac lipoma.

Cardiac lipomas are exceedingly rare benign tumors of the heart. They are usually asymptomatic. Occasionally, they are found on MRI as an incidental finding.

Quantification of cerebral tumour blood flow and permeability with T1-weighted dynamic contrast enhanced MRI: a feasibility study.

Objectives: Recently, T1-weighted DCE-MRI was proposed as an alternative to T2*-weighted DSC-MRI for the quantification of perfusion and permeability in brain tumors. The aim of the present feasibility study was to explore the clinical potential of the technique in different tumor types using a case-based review of initial results.

Patients And Methods: The method for data analysis was adapted from cerebral perfusion CT and applied in this study to a small group of patients with grade IV glioma and other brain tumors.

Phase II study of sunitinib malate in patients with recurrent high-grade glioma.

Receptor tyrosine kinase signaling causes profound neo-angiogenesis in high-grade gliomas (HGG). The KIT, PDGFR-α, and VEGFR2 genes are frequently amplified and expressed in HGG and are molecular targets for therapeutic inhibition by the small-molecule kinase inhibitor sunitinib malate. Twenty-one patients with progressive HGG after prior radiotherapy and chemotherapy received a daily dose of 37.

Cystic lesions of the female reproductive system: a review.

In order to avoid unnecessary therapy or treatment delay, it is important for the radiologist to be aware of the wide range of differential diagnoses for cystic lesions of the female reproductive system. This paper gives an overview of radiological findings in the variety of physiologic and pathologic cysts which may be encountered in this field.

Intramyometrial ectopic pregnancy in an ICSI patient following uterine artery embolization.

Myometrial pregnancy represents a rare subtype of ectopic pregnancy. A history of uterine artery embolization (UAE) because of symptomatic uterine fibroids, and assisted reproductive treatment may predispose to this unusual implantation site. A 40-year-old woman with a history of uterine fibroids underwent a transfer of two embryos after intracytoplasmic sperm injection treatment.

Age dependence of T1 perfusion MRI-based hemodynamic parameters in human kidneys.

Purpose: To determine the association between renal cortical perfusion parameters from T1-DCE magnetic resonance imaging (MRI) and age in human kidney.

Materials And Methods: Thirty-five patients (mean age: 53 years, SD = 15 years) were imaged using inversion recovery (IR)-prepared FLASH (pulse repetition time [TR] = 4.4 msec, echo time [TE] 2.

Deconvolution-based dynamic contrast-enhanced MR imaging of breast tumors: correlation of tumor blood flow with human epidermal growth factor receptor 2 status and clinicopathologic findings--preliminary results.

Purpose: To prospectively determine whether breast carcinomas possess characteristic values of tumor blood flow (TBF) that correlate with pathologic and molecular prognostic markers.

Materials And Methods: The institutional ethics committee approved this study. After informed consent was obtained, 57 women (age range, 31-80 years) with histologically proved breast cancer underwent routine magnetic resonance (MR) mammography, which included a whole-breast dynamic contrast material-enhanced (DCE) sequence.