Two ligand-binding sites on SARS-CoV-2 non-structural protein 1 revealed by fragment-based x-ray screening

The regular reappearance of coronavirus (CoV) outbreaks over the past 20 years has caused significant health consequences and financial burdens worldwide. The most recent and still ongoing novel CoV pandemic, caused by Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) has brought a range of devastating consequences. Due to the exceptionally fast development of vaccines, the mortality rate of the virus has been curbed to a significant extent. However, the limitations of vaccination efficiency and applicability, coupled with the still high infection rate, emphasise the urgent need for discovering safe and effective antivirals against SARS-CoV-2 through suppressing its replication and or attenuating its virulence. Non-structural protein 1 (nsp1), a unique viral and conserved leader protein, is a crucial virulence factor for causing host mRNA degradation, suppressing interferon (IFN) expression and host antiviral signalling pathways. In view of the essential role of nsp1 in the CoV life cycle, it is regarded as an exploitable target for antiviral drug discovery. Here, we report a variety of fragment hits against SARS-CoV-2 nsp1 identified by fragment-based screening via X-ray crystallography. We also determined the structure of nsp1 at atomic resolution (0.95 [A]). Binding affinities of hits against nsp1 were determined by orthogonal biophysical assays such as microscale thermophoresis and thermal sift assays. We identified two ligand-binding sites on nsp1, one deep and one shallow pocket, which are not conserved between the three medially relevant SARS, SARS-CoV-2 and MERS coronaviruses. Our study provides an excellent starting point for the development of more potent nsp1-targeting inhibitors and functional studies on SARS-CoV-2 nsp1.

Nationwide Survey of German Outpatient Gynecologic Oncology Practices during the Coronavirus Disease 2019 Pandemic: Reactions to the First Wave and Future Perspectives.

INTRODUCTION: In the spring of 2020, coronavirus disease 2019 posed a substantial challenge for countries and their healthcare systems. In Germany, over 70% of all cancer patients are treated in an outpatient setting, so gynecologic oncology practices are the guarantors of optimal patient care. We developed a survey to evaluate the management of gynecologic oncology patients. METHODS: The survey consisted of 38 questions and was sent to the members of the Berufsverband Niedergelassener Gynäkologischer Onkologen in Deutschland e.V. (BNGO), a professional association of gynecologic oncologists in the outpatient sector in Germany. RESULTS: The survey was completed by 54 out of 133 (41%) gynecologic oncologists from 14 out of 15 (93%) federal states where the BNGO is represented. Facing the pandemic, popular measures were mask requirements (100%), restriction of access to practices (94%), increased number of disinfectant dispensers (85%), installment of panes of acrylic glass (76%), or spatial alterations (67%). For most patients the pandemic had no influence on prioritization of therapies (82%) or prescribed systemic treatments (87%). Despite an increase in perceived psychological burden among the staff (72%), 85% (45/54) of the practices were not offered any additional psychological support. DISCUSSION AND CONCLUSION: As most cancer patients in Germany are treated in an outpatient setting, a suitable reaction of oncology centers to the new circumstances was crucial to secure optimal treatment and patient care. Nevertheless, the low prioritization of mental health or distress of healthcare workers poses a serious threat to the maintenance of optimal medical care in further waves of the pandemic.

Physical and Antibacterial Properties of Peppermint Essential Oil Loaded Poly (ε-caprolactone) (PCL) Electrospun Fiber Mats for Wound Healing.

The aim of this study was to fabricate and characterize various concentrations of peppermint essential oil (PEP) loaded on poly(ε-caprolactone) (PCL) electrospun fiber mats for healing applications, where PEP was intended to impart antibacterial activity to the fibers. SEM images illustrated that the morphology of all electrospun fiber mats was smooth, uniform, and bead-free. The average fiber diameter was reduced by the addition of PEP from 1.6 ± 0.1 to 1.0 ± 0.2 µm. Functional groups of the fibers were determined by Raman spectroscopy. Gas chromatography-mass spectroscopy (GC-MS) analysis demonstrated the actual PEP content in the samples. In vitro degradation was determined by measuring weight loss and their morphology change, showing that the electrospun fibers slightly degraded by the addition of PEP. The wettability of PCL and PEP loaded electrospun fiber mats was measured by determining contact angle and it was shown that wettability increased with the incorporation of PEP. The antimicrobial activity results revealed that PEP loaded PCL electrospun fiber mats exhibited inhibition against Staphylococcus aureus (gram-positive) and Escherichia coli (gram-negative) bacteria. In addition, an in-vitro cell viability assay using normal human dermal fibroblast (NHDF) cells revealed improved cell viability on PCL, PCLPEP1.5, PCLPEP3, and PCLGEL6 electrospun fiber mats compared to the control (CNT) after 48 h cell culture. Our findings showed for the first time PEP loaded PCL electrospun fiber mats with antibiotic-free antibacterial activity as promising candidates for wound healing applications.

Becoming sustainable: human determinants of change.

The author is a natural scientist and philosopher who has been involved in the global experience industry for more than 25 years. During this period of time he has developed a coherent, interdisciplinary body of knowledge that appears to be of essential interest as related to the transition towards a sustainable society: the Experience Science (Frank, 2011, 2012). Important scientific inputs come from underlying disciplines like cybernetics, system theory, psychology, and cognitive science. One of the key findings of the Experience Science is the innate structure of human experiencing. Any human experience includes 5 different experiential domains that influence and regulate each other: the emotional domain (feeling); the mental imagery domain (mental narrating); the sensorimotor domain (acting & perceiving); the linguistic domain (rational reasoning); the communicational domain (conversing). In the light of the Experience Science the dilemma of the current transition process towards a sustainable society becomes clearly visible. Any relevant attempt reduces the existing problems to more or less exclusively the linguistic, rational domain. Although ever evolving rational knowledge indeed is an indispensable prerequisite for a sustainable future this is not enough. Societal change towards a sustainable life-style can only happen if the whole experiential system gets a chance to reorganize itself. This leads to the following logical consequence. Any rational knowledge is embedded in a both emotional and narrative knowledge system that underlies and frames human reasoning. As long as human learning restricts itself to an exclusively rational attempt the underlying emotional and narrative program remains untouched. The learner hence continues orienting her attention into the direction determined by the underlying emotional and narrative paradigm. The paper delineates the experiential determinants of change and analyzes their specific, constitutive interrelations. From this a holistic choreography of change learning is outlined that pays tribute to the intrinsic transition principles represented by the human learner.

Generation of somatic electromechanical force by outer hair cells may be influenced by prestin-CASK interaction at the basal junction with the Deiter's cell.

The motor protein, prestin, situated in the basolateral plasma membrane of cochlear outer hair cells (OHCs), underlies the generation of somatic, voltage-driven mechanical force, the basis for the exquisite sensitivity, frequency selectivity and dynamic range of mammalian hearing. The molecular and structural basis of the ontogenetic development of this electromechanical force has remained elusive. The present study demonstrates that this force is significantly reduced when the immature subcellular distribution of prestin found along the entire plasma membrane persists into maturity, as has been described in previous studies under hypothyroidism. This observation suggests that cochlear amplification is critically dependent on the surface expression and distribution of prestin. Searching for proteins involved in organizing the subcellular localization of prestin to the basolateral plasma membrane, we identified cochlear expression of a novel truncated prestin splice isoform named prestin 9b (Slc26A5d) that contains a putative PDZ domain-binding motif. Using prestin 9b as the bait in a yeast two-hybrid assay, we identified a calcium/calmodulin-dependent serine protein kinase (CASK) as an interaction partner of prestin. Co-immunoprecipitation assays showed that CASK and prestin 9b can interact with full-length prestin. CASK was co-localized with prestin in a membrane domain where prestin-expressing OHC membrane abuts prestin-free OHC membrane, but was absent from this area for thyroid hormone deficiency. These findings suggest that CASK and the truncated prestin splice isoform contribute to confinement of prestin to the basolateral region of the plasma membrane. By means of such an interaction, the basal junction region between the OHC and its Deiter's cell may contribute to efficient generation of somatic electromechanical force.

Alexithymia and emotional distress in patients with central serous chorioretinopathy.

The authors studied 31 consecutive patients newly diagnosed with central serous chorioretinopathy (CSC) as compared with 31 age- and gender-matched control subjects, assessing emotional distress (ED), nine psychopathological symptoms, critical life events, and alexithymia. Results showed no difference in the number of critical life events; however CSC patients showed elevated ED and elevated scores on seven psychopathological symptoms, including hostility. Controlling for ED, CSC patients showed elevated alexithymia sum scores. Alexithymia was correlated with hostility. Our findings point to personality-based difficulties in emotional regulation associated with hostility in CSC.

Noise in magnetic resonance imaging: no risk for sensorineural function but increased amplitude variability of otoacoustic emissions.

OBJECTIVES: Objectives were to perform exact measurements of the noise exposure in a magnetic resonance imager and to investigate the effects of magnetic resonance imaging (MRI) noise on hearing sensitivity, which are still controversial, in a large number of patients. STUDY DESIGN: Prospective trial. METHODS: Acoustic noise during seven different MRI sequences was measured using a custom-made microphone containing no ferromagnetic parts. In 244 ears of 126 patients, pure-tone audiometry was performed once before and once after MRI noise, and distortion product otoacoustic emissions were measured once before and three times after MRI. RESULTS: The sound pressure level (SPL) at the patient's ear (with consideration of the sound-damping effect of the head support) ranged from 79.5 to 86.5 dB (A), depending on the MRI sequence, with brief sound pressure peaks up to 120 dB SPL. No significant incidence of temporary threshold shift and no reduction of mean distortion product otoacoustic emission amplitude were apparent. However, a significant increase in distortion product otoacoustic emission amplitude variability after noise exposure with equal distribution of increased and decreased amplitudes was observed. This variability showed a maximum at 15 minutes after noise, as demonstrated by continuous measurements. CONCLUSIONS: First, MRI noise does not impose a risk to hearing function under the measurement condition of a sound-damping head support or ear protectors. Second, a subtle effect is demonstrated by increased distortion product otoacoustic emission amplitude variability. Third, the increased otoacoustic emission amplitude variability is an audiometric parameter that is extremely sensitive to effects of acoustic stimulation, indicating more discrete changes in cochlear activity than pure-tone audiometry or otoacoustic emission amplitude reduction. A shift of the operation point (OP) of the outer hair cell (OHC) between basilar membrane and tectorial membrane is suggested as underlying cause.

Mechanical transduction in outer hair cells.

The outer hair cells are responsible for the exquisite sensitivity, frequency selectivity and dynamic range of the cochlea. These cells are part of a mechanical feedback system involving the basilar membrane and tectorial membrane. Transverse displacement of the basilar membrane results in relative motion between the tectorial membrane and the reticular lamina, causing deflection of the stereocilia and modulation of the open probability of their transduction channels. The resulting current causes a change of membrane potential, which in turn produces mechanical force, that is fed back into the motion of the basilar membrane. Experiments were conducted to address mechanical transduction mechanisms in both the stereocilia and the basolateral cell membrane, as well as modes of coupling of the outer hair cell force to the organ of Corti.

Nitrogen Photofixation at Nanostructured Iron Titanate Films.

Mild reducing agents such as ethanol, sodium formate, and humic acids effect the photofixation of nitrogen to ammonia and nitrate at thin films of nanostructured iron titanates. The reaction occurs in the presence of air and light, but is inhibited by the presence of carbon monoxide.