Conventional Electron Microscopy, Cryogenic Electron Microscopy, and Cryogenic Electron Tomography of Viruses.

Electron microscopy (EM) techniques have been crucial for understanding the structure of biological specimens such as cells, tissues and macromolecular assemblies. Viruses and related viral assemblies are ideal targets for structural studies that help to define essential biological functions. Whereas conventional EM methods use chemical fixation, dehydration, and staining of the specimens, cryogenic electron microscopy (cryo-EM) preserves the native hydrated state.

The Basic Architecture of Viruses.

Viruses are elegant macromolecular assemblies and constitute a paradigm of the economy of genomic resources; they must use simple general principles to complete their life cycles successfully. Viruses need only one or a few different capsid structural subunits to build an infectious particle, which is possible for two reasons: extensive use of symmetry and built-in conformational flexibility. Although viruses come in many shapes and sizes, two major symmetric assemblies are found: icosahedral and helical.

Efficacy of high doses of intravenous fosfomycin for treatment of urinary tract infection caused by KPC carbapenemase-producing Klebsiella pneumoniae. An observational study.

Objectives: To evaluate the efficacy of high-dose intravenous fosfomycin for the treatment of urinary tract infections (UTI) caused by KPC carbapenemase-producing Klebsiella pneumoniae (KPC-Kp). A secondary objective was to evaluate the impact of the results of fosfomycin susceptibility testing on prognosis.

Methods: This is an observational and retrospective study.

A RNA Dodecahedral Cage Inside a Human Virus Plays a Dual Biological Role in Virion Assembly and Genome Release Control.

Human rhinoviruses (RV) are among the most frequent human pathogens. As major causative agents of common colds they originate serious socioeconomic problems and huge expenditure every year, and they also exacerbate severe respiratory diseases. No anti-rhinoviral drugs or vaccines are available so far.

Structure of the aminoterminal domain of the birnaviral multifunctional VP3 protein and its unexplored critical role.

To overcome their limited genetic capacity, numerous viruses encode multifunctional proteins. The birnavirus VP3 protein plays key roles during infection, including scaffolding of the viral capsid during morphogenesis, recruitment, and regulation of the viral RNA polymerase, shielding of the double-stranded RNA genome and targeting of host endosomes for genome replication, and immune evasion. The dimeric form of VP3 is critical for these functions.