A rare variation of suprascapular artery originated from the axillary artery / Una rara variación de la arteria supraescapular originada de la arteria axilar

SUMMARY: The suprascapular artery (SSA) has been identified to be of clinical relevance to clavicular fracture, suprascapular neuropathy and surgical intervention of shoulder. Thus its origin and course have been intensively studied. In this case, we found a unilateral variation of the suprascapular artery, originating from the 1st segment of axillary artery, and sequentially penetrating the upper trunk of brachial plexus, passing through the suprascapular notch under the superior transverse scapular ligament. This case will be helpful to clinical management in cervical and shoulder region.

RESUMEN: Se ha identificado que la arteria supraescapular (ASS) tiene relevancia clínica en la fractura clavicular, la neuropatía supraescapular y la intervención quirúrgica del hombro. En consecuencia, su origen y su curso han sido ampliamente estudiados. En este caso, encontramos una variación unilateral de la arteria supraescapular, originada en el primer segmento de la arteria axilar, y que penetraba secuencialmente en el tronco superior del plexo braquial, pasando a través de la incisura supraescapular debajo del ligamento escapular transverso superior. Este caso será útil para el manejo clínico en la región cervical y del hombro.

Inhibition of autophagy alleviates the senescent state of rat mesenchymal stem cells during long-term culture.

Following a limited number of cell divisions, mesenchymal stem cells (MSCs) undergo senescence, and these senescent cells maintain metabolic modification and remain viable for long periods. Autophagy, an intracellular bulk degradation process, provides a survival effect for cells under stress. In this study, the effect of autophagy on senescent MSCs was analyzed. Following serial passaging, rat MSCs underwent replicative senescence, characterized by positive staining for senescence-associated ß-galactosidase (SA-ß-gal), and increased expression levels of p16 and p21. During MSC senescence, the levels of autophagic activity were increased, a greater number of autophagic vacuoles were observed in senescent MSCs by transmission electron microscopy, acridine orange staining was elevated and the expression levels of autophagy­related proteins (microtubule­associated protein 1A/1B­light chain 3-II, Atg7 and Atg12) were increased. The role of autophagy in MSC senescence was further investigated through pharmacological inhibition of autophagy with bafilomycin A1 and 3-methyladenine. Inhibition of autophagy by pharmacological means reduced the rate of positive staining for SA-ß-gal and the expression levels of senescence­related proteins. In conclusion, these findings suggest that autophagy is activated during senescence and the autophagic activity may be a requirement for maintaining the senescent state of MSCs.