Potential novel therapeutic strategies in cystic fibrosis: antimicrobial and anti-biofilm activity of natural and designed α-helical peptides against Staphylococcus aureus, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia.

BACKGROUND: Treatment of cystic fibrosis-associated lung infections is hampered by the presence of multi-drug resistant pathogens, many of which are also strong biofilm producers. Antimicrobial peptides, essential components of innate immunity in humans and animals, exhibit relevant in vitro antimicrobial activity although they tend not to select for resistant strains. RESULTS: Three α-helical antimicrobial peptides, BMAP-27 and BMAP-28 of bovine origin, and the artificial P19(9/B) peptide were tested, comparatively to Tobramycin, for their in vitro antibacterial and anti-biofilm activity against 15 Staphylococcus aureus, 25 Pseudomonas aeruginosa, and 27 Stenotrophomonas maltophilia strains from cystic fibrosis patients. All assays were carried out in physical-chemical experimental conditions simulating a cystic fibrosis lung. All peptides showed a potent and rapid bactericidal activity against most P. aeruginosa, S. maltophilia and S. aureus strains tested, at levels generally higher than those exhibited by Tobramycin and significantly reduced biofilm formation of all the bacterial species tested, although less effectively than Tobramycin did. On the contrary, the viability-reducing activity of antimicrobial peptides against preformed P. aeruginosa biofilms was comparable to and, in some cases, higher than that showed by Tobramycin. CONCLUSIONS: The activity shown by α-helical peptides against planktonic and biofilm cells makes them promising "lead compounds" for future development of novel drugs for therapeutic treatment of cystic fibrosis lung disease.

A new dose-intense epoetin alfa regimen effective in anemic cancer patients receiving chemotherapy: an open-label, non randomized, pilot study.

BACKGROUND: Chronic anemia is a well-recognized complication of both cancer and cytotoxic treatments and is associated with symptoms (e.g., fatigue, dyspnea) that may induce or exacerbate functional deterioration. The use of recombinant human erythropoetin (rHuEPO epoetin alfa) clearly increased haemoglobin (Hb) levels, decreased transfusion needs and allowed recovery of quality of life in anemic cancer patients (pts) undergoing chemotherapy (CT). The purpose of this open-label, non randomized, pilot study was to assess the safety and efficacy of an intensive 19-day epoetin alfa treatment in anemic patients with solid tumors receiving chemotherapy. TREATMENT: patients received a single induction s.c. dose of epoetin alfa 40,000 IU day 1 and twice a dose of 10,000 IU s.c. (8.00 a.m.- 8:00 p.m.) on days 3, 5, 8, 10, 12, 15, 17 and 19. The total dose of epoetin alfa per patient was 200, 000 IU. Iron supplementation: 125 mg i.v. days and 8. Soluble transferrin receptor (sTfR) levels were performed on days 1,8 and 15. This epoetin induction regimen was not followed by an epoetin maintenance therapy. PATIENTS: Twenty-nine anemic (Hb< or =11.5 g/dL) pts with non myeloid malignancies undergoing CT were included in the study. RESULTS: At baseline the mean Hb level was 9.41 g/dl. On day 8, the mean Hb level increased to 10.07 g/dl (p<0.0001), reaching 10.68 g/dl on day 15 (p<0.0001). On days 22 and 29, the mean Hb levels increased to 10.93 and 11.05 g/dl, (p=0.002 and 0.033, respectively). No patient received blood transfusions. The global mean increase of Hb level was 1.64 g/dl (basal to d 29). It was defined as a major response: an increase of Hb levels > 1.5 g/dl. A rate of 62% (18/29 patients) of major responses was observed on day 21. Moreover, 25/29 patients (86.2%) presented an increase of Hb levels > 1 g/dl after 21 days. On days 8 and 15, the mean sTfR levels had increased significantly ( p=0.021 and 0.001, respectively). The increase of mean sTfR level after 15 days correlated significantly with the increase of mean Hb level in the first two weeks of epoetin therapy (p=0.05). Epoetin alfa has been well tolerated so far in the study. CONCLUSION: The results of the present study suggest that an induction dose of 40,000 IU of epoetin alfa, followed by 8 maintenance doses of 20,000 IU each, may improve the standard response in terms of both time to response and Hb increase. Moreover, the Hb levels seemed to increase after epoetin therapy discontinuation (d22-29).