Current knowledge on selected rehabilitative methods used in post-stroke recovery

Understanding brain plasticity after stroke is important in developing rehabilitation strategies. Active movement therapies show considerable promise but their individual application is still not fully implemented. Among the analysed, available therapeutic modalities, some became widely used in therapeutic practice. Thus, we selected three relatively new methods, i.e. mirror therapy, motor imagery and constraint-induced movement therapy (CIMT). Mirror therapy was initially used in the treatment of phantom pain in patients with amputated limbs and later, in stroke patients. Motor imagery is widely used in sport to improve performance, which raises the possibility of applying it both as a rehabilitative method and in accessing the motor network independently of recovery. Whereas CIMT is based on the paradigm that impairment of arm function is exacerbated by learned non-use and that this, in turn, leads to loss of cortical representation in the upper limb

Human coronavirus NL63 utilizes heparan sulfate proteoglycans for attachment to target cells

Human coronavirus NL63 (HCoV-NL63) is an alphacoronavirus that was first identified in 2004 in the nasopharyngeal aspirate from a 7-month-old patient with a respiratory tract infection. Previous studies showed that HCoV-NL63 and the genetically distant severe acute respiratory syndrome (SARS)-CoV employ the same receptor for host cell entry, angiotensin-converting enzyme 2 (ACE2), but it is largely unclear whether ACE2 interactions are sufficient to allow HCoV-NL63 binding to cells. The present study showed that directed expression of angiotensin-converting enzyme 2 (ACE2) on cells previously resistant to HCoV-NL63 renders them susceptible, showing that ACE2 protein acts as a functional receptor and that its expression is required for infection. However, comparative analysis showed that directed expression or selective scission of the ACE2 protein had no measurable effect on virus adhesion. In contrast, binding of HCoV-NL63 to heparan sulfates was required for viral attachment and infection of target cells, showing that these molecules serve as attachment receptors for HCoV-NL63. IMPORTANCE ACE2 protein was proposed as a receptor for HCoV-NL63 already in 2005, but an in-depth analysis of early events during virus infection had not been performed thus far. Here, we show that the ACE2 protein is required for viral entry but that it is not the primary binding site on the cell surface. Conducted research showed that heparan sulfate proteoglycans function as adhesion molecules, increasing the virus density on cell surface and possibly facilitating the interaction between HCoV-NL63 and its receptor. Obtained results show that the initial events during HCoV-NL63 infection are more complex than anticipated and that a newly described interaction may be essential for understanding the infection process and, possibly, also assist in drug design