Modulation of NK cell activation by exogenous calcium from alginate dressings in vitro.

Natural Killer (NK) cells participate in the defense against infection by killing pathogens and infected cells and secreting immuno-modulatory cytokines. Defects in NK cell activity have been reported in obese, diabetic, and elderly patients that are at high risk of developing infected chronic wounds. Calcium alginate dressings are indicated for the debridement during the inflammatory phase of healing. Since calcium ions are major activators of NK cells, we hypothesized that these dressings could enhance NK functions, as investigated in vitro herein. Primary human blood NK cells were freshly-isolated from healthy volunteers and exposed to conditioned media (CM) from two alginate dressings, Algosteril® (ALG, pure Ca2+ alginate) and Biatain® Alginate (BIA, Ca2+ alginate with CMC), in comparison with an exogenous 3mM calcium solution. Our results demonstrated that exogenous calcium and ALG-CM, but not BIA-CM, induced NK cell activation and enhanced their capacity to kill their targets as a result of increased degranulation. NK cell stimulation by ALG depended on the influx of extracellular Ca2+ via the SOCE Ca2+ permeable plasma membrane channels. ALG-CM also activated NK cell cytokine production of IFN-γ and TNF-α through a partly Ca2+-independent mechanism. This work highlights the non-equivalence between alginate dressings for NK cell stimulation and shows that the pure calcium alginate dressing Algosteril® enhances NK cell cytotoxic and immuno-modulatory activities. Altogether, these results underline a specific property of this medical device in innate defense that is key for the cutaneous wound healing process.

Epistaxis and its management: an observational pilot study carried out in 23 hospital centres in France.

OBJECTIVE: The purpose of this study is to describe the treatment of epistaxis in hospital emergency departments and to identify the principal risk factors for more severe episodes of bleeding. STUDY PROTOCOL: Prospective cross-sectional epidemiological study MATERIAL AND METHODS: This study was carried out in 23 hospital centres in France, most of them teaching hospitals. Every patient presenting non-traumatic epistaxis or else associated with hereditary hemangioma during two consecutive and separate 24-hour periods were included. RESULTS: Fifty patients were included in the study. Nasal bleeding was stopped within 30 minutes for 47 patients. Fourteen patients were hospitalized. The risk factors for severe epistaxis included either copious bleeding or else bleeding for more than 6 hours or patients aged 65 and over. A history of repeated nasal packing and/or taking medication with a known hemorrhagic risk was associated with the amount and duration of bleeding (p < 0.05). CONCLUSION: Risk factors for severe epistaxis should be identified as to improve patient care and avoid treatment failure or useless hospitalization.

Evaluation of calcium alginate nasal packing (Algostéril) versus Polyvinyl acetal (Merocel) for nasal packing after inferior turbinate resection.

Nasal packing is commonly used to control postoperative bleeding in patients undergoing endonasal surgical procedures. Bleeding and pain on packing removal are frequently reported. The principal objective of this study was to investigate the efficacy and safety of Algosteril to control post-operative nasal bleeding. The secondary objective was to assess nasal bleeding and pain on packing removal, and to evaluate the endoscopic appearance of nasal mucosa 9 days after the procedure. This open, multicenter, randomized, controlled study was conducted on 50 patients undergoing partial bilateral inferior turbinectomy, packed with Algosteril on one side versus Polyvinyl acetal tampon (Merocel) on the other side following a left/right randomization. Both nasal packs effectively prevented post-operative bleeding. However, bleeding on packing removal was statistically less frequent and less severe with Algosteril than with Polyvinyl acetal (p = 0.016). In addition, pain was statistically lower with Algosteril than with Polyvinyl acetal (p = 0.0001). A trend to a better healing of the wound on day 9 was observed with Algosteril, leading us to further investigations. Algosteril nasal packing is as effective as Polyvinyl acetal in preventing postoperative bleeding following partial inferior turbinate resection. Its removal, however, is less traumatic for the nasal mucosa and less painful for the patient, therefore improving patient's comfort.