Effects of Dopamine on stem cells and its potential roles in the treatment of inflammatory disorders: a narrative review.

Inflammation is the host's protective response against harmful external stimulation that helps tissue repair and remodeling. However, excessive inflammation seriously threatens the patient's life. Due to anti-inflammatory effects, corticosteroids, immunosuppressants, and monoclonal antibodies are used to treat various inflammatory diseases, but drug resistance, non-responsiveness, and severe side effect limit their development and application. Therefore, developing other alternative therapies has become essential in anti-inflammatory therapy. In recent years, the in-depth study of stem cells has made them a promising alternative drug for the treatment of inflammatory diseases, and the function of stem cells is regulated by a variety of signals, of which dopamine signaling is one of the main influencing factors. In this review, we review the effects of dopamine on various adult stem cells (neural stem cells, mesenchymal stromal cells, hematopoietic stem cells, and cancer stem cells) and their signaling pathways, as well as the application of some critical dopamine receptor agonists/antagonists. Besides, we also review the role of various adult stem cells in inflammatory diseases and discuss the potential anti-inflammation function of dopamine receptors, which provides a new therapeutic target for regenerative medicine in inflammatory diseases.

Is Hypercalcemia a Frequent Complication following Local Use of Calcium Sulfate with Antibiotics for the Treatment of Extremity Posttraumatic Osteomyelitis? A Preliminary Study.

BACKGROUND: Previous study had reported hypercalcemia as a frequent complication (20%) following local use of antibiotic-eluting calcium sulfate (CS) during treatment of periprosthetic joint infections (PJIs). However, whether this complication may occur in patients who receive local CS implantation for management of posttraumatic osteomyelitis (OM) remains unclear. METHODS: Between April 2016 and May 2017, we included 55 patients with extremity posttraumatic OM who received local antibiotic-loaded CS therapy. Serum calcium levels were detected preoperatively and on the 1st, 3rd, and 7th postoperative days (PODs). Comparisons were performed regarding serum calcium levels among the four time points and between two different CS volume groups (≤ 20 cc group and > 20 cc group). Additionally, potential associations were examined regarding CS volume and preoperative calcium level with postoperative calcium levels, respectively. RESULTS: Altogether 46 males and 9 females were included, with a median CS volume of 20 cc. Outcomes showed that prevalence of asymptomatic hypocalcemia was more frequent, with 16.4% before surgery and 60%, 53.8%, and 25% on the 1st, 3rd, and 7th PODs, respectively. Hypercalcemia was not found in any patients, at any time point. In addition, significant differences were identified regarding serum calcium levels among different time points, suggesting significantly decreased calcium levels on the 1st (P < 0.001) and 3rd PODs (P < 0.001) and back to near preoperative level on the 7th POD (P = 0.334). However, no statistical differences were observed regarding serum calcium levels between the two CS volume groups at any time points (P > 0.05). Moreover, no significant links were identified between CS volume and postoperative calcium levels (P > 0.05). Serum calcium levels on the 3rd (P = 0.019) and 7th PODs (P = 0.036) were significantly associated with the preoperative calcium level. CONCLUSIONS: In contrast to what had occurred in PJI patients, asymptomatic hypocalcemia appeared to be more frequent in this cohort with posttraumatic OM. Hypercalcemia may be an infrequent complication before and after local CS use for the treatment of extremity posttraumatic OM.