Fetal membranes as a source of stem cells

In recent years, a constant growth of knowledge and clinical applications of stem cells have been observed. Mesenchymal stromal cells, also described as mesenchymal stem cells (MSCs) represent a particular cell type for research and therapy because of their ability to differentiate into mesodermal lineage cells. The most investigated source of MSCs is bone marrow (BM). Yet, collection of BM is an invasive procedure associated with significant discomfort to the patient. The procedure results in a relatively low number of these cells, which can decrease with donor's age. Therefore, it seems to be very important to find other sources of mesenchymal stem cells nowadays. A human placenta, which is routinely discarded postpartum, in spite of its natural aging process, is still a rich source of stem cells capable to proliferate and in vitro differentiate in many directions. Besides homing and differentiation in the area of injury, MSCs there elicit strong paracrine effects stimulating the processes of repair. In this review, we focus on the biology, characteristics and potential clinical applications of cells derived from human fetal membranes: amnion and chorion.     

Discovery of novel protein tyrosine phosphatase sigma inhibitors through the virtual screening with modified scoring function

Protein tyrosine phosphatase sigma (PTPσ) is a promising target for the development of therapeutics for the neurological diseases caused by the impaired recovery from neural injury. Based on the virtual screening with the scoring function involving a new accurate solvation energy term and in vitro enzyme assay, we identified seven competitive PTPσ inhibitors with the associated IC₅₀ values ranging from 5 to 11 μM. These inhibitors are structurally diverse and expected to have desirable physicochemical properties as a drug candidate. Therefore, they deserve consideration for further development by structure–activity relationship studies to optimize the inhibitory activities against the neurological diseases. Structural features relevant to the stabilization of the newly identified inhibitors in the active site of PTPσ are discussed in detail.     

Mechanoreceptors of the ligaments and tendons around the knee

Proprioceptive inputs from the joints and limbs arise from mechanoreceptors in the muscles, ligaments and tendons. The knee joint has a wide range of movements, and proper neuroanatomical organization is critical for knee stability. Four ligaments (the anterior (ACL) and posterior (PCL) cruciate ligaments and the medial (MCL) and lateral (LCL) collateral ligaments) and four tendons (the semitendinosus (STT), gracilis (GT), popliteal (PoT), and patellar (PaT) tendons) from eight fresh frozen cadavers were harvested. Each harvested tissue was divided into its bone insertion side and its tendinous part for immunohistochemical examination using S100 staining. Freeman–Wyke's classification was used to identify the mechanoreceptors. The mechanoreceptors were usually located close to the bone insertion. Free nerve endings followed by Ruffini endings were the most common mechanoreceptors overall. No Pacini corpuscles were observed; free nerve endings and Golgi‐like endings were most frequent in the PCL (PCL‐PaT: P = 0.0.1, PCL‐STT: P = 0.00), and Ruffini endings in the popliteal tendon (PoT‐PaT: P = 0.00, Pot‐STT: P = 0.00, PoT‐LCL: P = 0.00, PoT‐GT: P = 0.00, PoT‐ACL: P = 0.09). The cruciate ligaments had more mechanoreceptors than the medial structures (MS) or the patellar tendon (CR‐Pat: P = 0.000, CR‐MS: P = 0.01). The differences in mechanoreceptor distributions between the ligaments and tendons could reflect the different roles of these structures in the dynamic coordination of knee motion. Clin. Anat. 29:789–795, 2016. © 2016 Wiley Periodicals, Inc.     

Recurrent polymyositis triggered by bronchiectasis‐associated infections

Polymyositis is a cell‐mediated autoimmune disease and various systemic infections can trigger it. However, there have been only rare reports of recurrent polymyositis triggered by systemic infections. We report the case of a 69‐year‐old woman with recurrent polymyositis triggered by bronchiectasis‐associated infections. This case indicates that recurrent polymyositis triggered by systemic infections suggests a non‐specific autoimmune antigenic response of polymyositis.