Novel Coronavirus (2019-nCoV) in Disguise

Novel coronavirus (2019-nCoV) pandemic is currently one of the most influential topics as it not only impacts the field of medicine but most importantly, it affects the lives of many individuals throughout the world. We report an interesting 2019-nCoV case in a tertiary community hospital with the initial concern of acute pyelonephritis without respiratory symptoms that ultimately led to the quarantine of a number of healthcare providers. This case emphasizes the importance of radiological evidence in diagnosing 2019-nCoV in the setting of an initial atypical presentation. It also serves as an example of how healthcare providers may need to increase their suspicion for COVID-19 to ensure self-protection and prompt diagnosis in the era of an ongoing pandemic

Stick index of knots and links in the cubic lattice

The cubic lattice stick index of a knot type is the least number of sticks necessary to construct the knot type in the 3-dimensional cubic lattice. We present the cubic lattice stick index of various knots and links, including all (p,p+1)-torus knots, and show how composing and taking satellites can be used to obtain the cubic lattice stick index for a relatively large infinite class of knots. Additionally, we present several bounds relating cubic lattice stick index to other known invariants.Comment: 16 pages, 12 figure

Single-cell tracking demonstrates copper chaperone Atox1 to be required for breast cancer cell migration

Copper ions are needed for several hallmarks of cancer. However, the involved pathways, mechanisms, and copper-binding proteins are mostly unknown. We recently found that cytoplasmic Antioxidant 1 copper chaperone (Atox1), which is up-regulated in breast cancer, is localized at the lamellipodia edges of aggressive breast cancer cells. To reveal molecular insights into a putative role in cell migration, we here investigated breast cancer cell (MDA-MB-231) migration by video microscopy as a function of Atox1. Tracking of hundreds of individual cells (per condition) over a 9-h time series revealed that cell migration velocity and directionality are significantly reduced upon Atox1 silencing in the cells. Because silencing of the copper transporter ATP7A also reduced cell migration, these proteins appear to be on the same pathway, suggesting that their well-known copper transport activity is involved. In-cell proximity ligation assays demonstrated that Atox1, ATP7A, and the proenzyme of lysyl oxidase (LOX; copper-loaded via ATP7A) are all in close proximity and that LOX activity is reduced upon Atox1 silencing in the cells. Since LOX is an established player in cancer cell migration, our results imply that Atox1 mediates breast cancer cell migration via coordinated copper transport in the ATP7A-LOX axis. Because individual cell migration is an early step in breast cancer metastasis, Atox1 levels in tumor cells may be a predictive measure of metastasis potential and serve as a biomarker for copper depletion therapy

Altered chemomechanical coupling causes impaired motility of the kinesin-4 motors KIF27 and KIF7.

Kinesin-4 motors play important roles in cell division, microtubule organization, and signaling. Understanding how motors perform their functions requires an understanding of their mechanochemical and motility properties. We demonstrate that KIF27 can influence microtubule dynamics, suggesting a conserved function in microtubule organization across the kinesin-4 family. However, kinesin-4 motors display dramatically different motility characteristics: KIF4 and KIF21 motors are fast and processive, KIF7 and its Drosophila melanogaster homologue Costal2 (Cos2) are immotile, and KIF27 is slow and processive. Neither KIF7 nor KIF27 can cooperate for fast processive transport when working in teams. The mechanistic basis of immotile KIF7 behavior arises from an inability to release adenosine diphosphate in response to microtubule binding, whereas slow processive KIF27 behavior arises from a slow adenosine triphosphatase rate and a high affinity for both adenosine triphosphate and microtubules. We suggest that evolutionarily selected sequence differences enable immotile KIF7 and Cos2 motors to function not as transporters but as microtubule-based tethers of signaling complexes