Analysis of the DNA-binding sequence specificity of the archaeal transcriptional regulator Ss-LrpB from Sulfolobus solfataricus by systematic mutagenesis and high resolution contact probing

To determine the sequence specificity of dimeric Ss-LrpB, a high resolution contact map was constructed and a saturation mutagenesis conducted on one half of the palindromic consensus box. Premodification binding interference indicates that Ss-LrpB establishes most of its tightest contacts with a single strand of two major groove segments and interacts with the minor groove at the center of the box. The requirement for bending is reflected in the preference for an A+T rich center and confirmed with C·G and C·I substitutions. The saturation mutagenesis indicates that major groove contacts with C·G at position 5 and its symmetrical counterpart are most critical for the specificity and strength of the interaction. Conservation at the remaining positions improved the binding. Hydrogen bonding to the O(6) and N(7) acceptor atoms of the G(5′) residue play a major role in complex formation. Unlike many other DNA-binding proteins Ss-LrpB does not establish hydrophobic interactions with the methyls of thymine residues. The binding energies determined from the saturation mutagenesis were used to construct a sequence logo, which pin-points the overwhelming importance of C·G at position 5. The knowledge of the DNA-binding specificity will constitute a precious tool for the search of new physiologically relevant binding sites for Ss-LrpB in the genome

Transitional cell carcinoma of suspected ureteral origin, with intra-abdominal and distant metastases in two horses

The present paper describes two cases of suspected urothelial carcinomas with local lymphatic metastases, and distant metastases in the lungs. In one case, liver metastases were also present. Both cases are documented with an extensive clinical report, using bloodwork, rectal examination, ultrasonography, cytology of abdominal fluid and, in one case, also urine analysis, radiography and transrectal biopsy to come to a diagnosis of abdominal malignancy. Subsequently, the post-mortem exam, histopathology and immunohistochemistry are described and illustrated

Prevention and control of cholera with household and community water, sanitation and hygiene (WASH) interventions: A scoping review of current international guidelines.

INTRODUCTION: Cholera remains a frequent cause of outbreaks globally, particularly in areas with inadequate water, sanitation and hygiene (WASH) services. Cholera is spread through faecal-oral routes, and studies demonstrate that ingestion of Vibrio cholerae occurs from consuming contaminated food and water, contact with cholera cases and transmission from contaminated environmental point sources. WASH guidelines recommending interventions for the prevention and control of cholera are numerous and vary considerably in their recommendations. To date, there has been no review of practice guidelines used in cholera prevention and control programmes. METHODS: We systematically searched international agency websites to identify WASH intervention guidelines used in cholera programmes in endemic and epidemic settings. Recommendations listed in the guidelines were extracted, categorised and analysed. Analysis was based on consistency, concordance and recommendations were classified on the basis of whether the interventions targeted within-household or community-level transmission. RESULTS: Eight international guidelines were included in this review: three by non-governmental organisations (NGOs), one from a non-profit organisation (NPO), three from multilateral organisations and one from a research institution. There were 95 distinct recommendations identified, and concordance among guidelines was poor to fair. All categories of WASH interventions were featured in the guidelines. The majority of recommendations targeted community-level transmission (45%), 35% targeted within-household transmission and 20% both. CONCLUSIONS: Recent evidence suggests that interventions for effective cholera control and response to epidemics should focus on case-centred approaches and within-household transmission. Guidelines did consistently propose interventions targeting transmission within households. However, the majority of recommendations listed in guidelines targeted community-level transmission and tended to be more focused on preventing contamination of the environment by cases or recurrent outbreaks, and the level of service required to interrupt community-level transmission was often not specified. The guidelines in current use were varied and interpretation may be difficult when conflicting recommendations are provided. Future editions of guidelines should reflect on the inclusion of evidence-based approaches, cholera transmission models and resource-efficient strategies

Confocal Depolarized Dynamic Light Scattering: a Novel Technique for the Characterization of Nanoparticles in Complex Fluids

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Vestibular Infant Screening (VIS)–Flanders : results after 1.5 years of vestibular screening in hearing-impaired children

Due to the close anatomical relationship between the auditory and vestibular end organs, hearing-impaired children have a higher risk for vestibular dysfunction, which can affect their (motor) development. Unfortunately, vestibular dysfunction often goes unnoticed, as vestibular assessment in these children is not standard of care nowadays. To timely detect vestibular dysfunction, the Vestibular Infant Screening–Flanders (VIS–Flanders) project has implemented a basic vestibular screening test for hearing-impaired infants in Flanders (Belgium) with a participation rate of 86.7% during the first year and a half. The cervical Vestibular Evoked Myogenic Potentials (cVEMP) test was applied as vestibular screening tool to map the occurrence of vestibular (mainly saccular) dysfunction in this population. At the age of 6 months, 184 infants were screened. No refers on vestibular screening were observed in infants with permanent conductive hearing loss. In infants with permanent sensorineural hearing loss, a cVEMP refer rate of 9.5% was observed. Failure was significantly more common in infants with severe-profound compared to those with mild-moderate sensorineural hearing loss (risk ratio = 9.8). Since this is the first regional study with a large sample size and successful participation rate, the VIS–Flanders project aims to set an example for other regions worldwide

Setting priorities for humanitarian water, sanitation and hygiene research: a meeting report

Recent systematic reviews have highlighted a paucity of rigorous evidence to guide water, sanitation and hygiene (WASH) interventions in humanitarian crises. In June 2017, the Research for Health in Humanitarian Crises (R2HC) programme of Elhra, convened a meeting of representatives from international response agencies, research institutions and donor organisations active in the field of humanitarian WASH to identify research priorities, discuss challenges conducting research and to establish next steps. Topics including cholera transmission, menstrual hygiene management, and acute undernutrition were identified as research priorities. Several international response agencies have existing research programmes; however, a more cohesive and coordinated effort in the WASH sector would likely advance this field of research. This report shares the conclusions of that meeting and proposes a research agenda with the aim of strengthening humanitarian WASH policy and practice

The protein–DNA contacts in RutR·carAB operator complexes

Pyrimidine-specific regulation of the upstream carP1 promoter of the carbamoylphosphate synthase operon of Escherichia coli requires numerous trans-acting factors: the allosteric transcription regulator RutR, the nucleoid-associated protein integration host factor, and the trigger enzymes aminopeptidase A and PyrH (UMP-kinase). RutR, a TetR family member, binds far upstream of carP1. Here, we establish a high-resolution contact map of RutR•carP1 complexes for backbone and base-specific contacts, analyze DNA bending, determine the DNA sequence specificity of RutR binding by saturation mutagenesis, demonstrate that uracil but not thymine is the physiologically relevant ligand that inhibits the DNA binding capacity of RutR and build a model of the RutR·operator DNA complex based on the crystal structures of RutR and of the DNA-bound family member QacR. Finally, we test the validity of this model with site-directed mutagenesis of the helix–turn–helix DNA binding motif and in vitro binding studies with the cognate purified mutant RutR proteins

STAT2 signaling restricts viral dissemination but drives severe pneumonia in SARS-CoV-2 infected hamsters

Emergence of SARS-CoV-2 causing COVID-19 has resulted in hundreds of thousands of deaths. In search for key targets of effective therapeutics, robust animal models mimicking COVID-19 in humans are urgently needed. Here, we show that Syrian hamsters, in contrast to mice, are highly permissive to SARS-CoV-2 and develop bronchopneumonia and strong inflammatory responses in the lungs with neutrophil infiltration and edema, further confirmed as consolidations visualized by micro-CT alike in clinical practice. Moreover, we identify an exuberant innate immune response as key player in pathogenesis, in which STAT2 signaling plays a dual role, driving severe lung injury on the one hand, yet restricting systemic virus dissemination on the other. Our results reveal the importance of STAT2-dependent interferon responses in the pathogenesis and virus control during SARS-CoV-2 infection and may help rationalizing new strategies for the treatment of COVID-19 patients. SARS-CoV-2 infection can result in severe lung inflammation and pathology, but host response remains incompletely understood. Here the authors show in Syrian hamsters that STAT2 signaling restricts systemic virus dissemination but also drives severe lung injury, playing a dual role in SARS-CoV-2 infection