Mahir Kaya

The use of 808-nm light therapy to treat experimental chronic osteomyelitis induced in rats by methicillin-resistant Staphylococcus aureus.

BACKGROUND DATA In vivo and in vitro studies have reported that laser energy in differing wavelengths and irradiation regimes has a potential bactericidal effect on Staphylococcus aureus. OBJECTIVE The purpose of this study was to investigate whether a light wavelength of 808  nm in varying doses has an effect on chronic osteomyelitis induced experimentally in the rat tibia. METHODS Intramedullary cavities were surgically created in the left tibias of 39 adult Wistar albino rats. Five randomly selected subjects were injected with a sterile saline solution, and methicillin-resistant S. aureus (MRSA) was used to induce osteomyelitis in the remaining rats. After 3 weeks, rats with evidence of osteomyelitis were treated with debridement alone (n = 7), with debridement plus laser irradiation to induce photoeradication (n = 21), or were not treated at all [negative control, (n = 6)]. Active irradiation was performed using an 808  nm, 100  mW continuous-wave diode laser with a beam spot size of 0.7854  cm(2) (irradiance = 127.3  mW/cm(2)). Laser treatment commenced immediately after debridement surgery and was applied daily for 5 consecutive days. Irradiation lasted 60  secs (6  J at 7.64  J/cm(2): n = 7), 120  secs (12  J at 15.29  J/cm(2): n = 7), or 180  secs (18  J at 22.93  J/cm(2): n = 7). Rats in the sham and negative control groups were killed 21 days post-induction surgery, and those in the treatment groups were killed after 42 days. Following killing, tibias were removed and analyzed histopathologically, radiographically, and microbiologically. RESULTS Histopathological analysis showed that infection levels had decreased by 37%, 67%, 81%, and 93% in the groups treated by debridement or by debridement plus 7.64, 15.29, and 22.93  J/cm(2) light therapy, respectively, compared to the negative control group. Osteomyelitis-induced rats had the highest bacteria count (5 × 10(5)). Bacterial counts fell to 1.6 × 10(4), 4.3 × 10(2), 5.5 × 10(1), and 3.3 × 10(0) in groups treated by debridement or by debridement plus 7.64, 15.29, and 22.93  J/cm(2) light therapy, respectively, compared to the negative control group. CONCLUSIONS Within the limitations of this study, laser phototherapy with the appropriate irradiation parameters appears to be a promising adjunct and/or alternative technique to pharmacological agents in the treatment of osteomyelitis. The 808  nm 100  mW (127.3  mW/cm(2)) laser device used in this study achieved a maximum effect with an irradiation time of 180  secs, delivering 18  J at an energy density of 22.93  J/cm(2).

Local treatment of chronic osteomyelitis with surgical debridement and tigecycline-impregnated calcium hydroxyapatite: an experimental study

OBJECTIVE The aim of this study was to determine the efficacy of tigecycline-impregnated hydroxyapatite in the local treatment of chronic osteomyelitis experimentally induced in rat tibias with methicillin-resistant Staphylococcus aureus. STUDY DESIGN Monocortical defects were established in the left tibias of 32 adult Wistar albino rats. Five rats were randomly selected and injected intramedullarly with saline solution (group 1), whereas chronic osteomyelitis was induced in other rats by intramedullary injection of S. aureus. Infected rats were then randomized and divided into 4 groups: group 2, no further treatment; group 3, debridement only; group 4, debridement followed by implantation of calcium hydroxyapatite; and group 5, debridement followed by implantation of tigecycline-impregnated calcium hydroxyapatite. On day 21 after induction, all rats in groups 2-5 showed signs of osteomyelitis. Rats in groups 1 and 2 were killed on day 21 after induction, whereas rats in groups 3, 4, and 5 underwent debridement surgery on day 21 after induction and were killed 21 days after debridement surgery. Tibias were analyzed histopathologically and cultured for S. aureus. RESULTS Compared with group 2, histopathologic disease severity scores in groups 3, 4, and 5 were 37%, 44%, and 83% lower, respectively. Nontreated infected rats had the highest bacteria count (mean 5 × 10(5) colony-forming units/g bone), and bacterial count was 26%, 29%, and 79% lower in groups 3, 4, and 5, respectively, compared with group 2. CONCLUSIONS Tigecycline-impregnated hydroxyapatite can have a potential in the treatment of chronic osteomyelitis of methicillin-resistant S. aureus origin, which may be considered as a therapeutic alternative by surgeons dealing with osteomyelitis.

Effect of Tadalafil on Renal Resistivity and Pulsatility Index in Partial Ureteral Obstruction

Introduction: To investigate the effect of tadalafil on Resistivity Index (RI) and Pulsatility Index (PI) in partial unilateral ureteral obstruction (PUUO). Methods: Twelve New Zealand rabbits were assigned into two groups. Baseline renal Doppler ultrasonography (USG) was performed in all rabbits. The rabbits in group 1 received tadalafil for a month (10 mg/72 h) and group 2 was defined as sham. After 1 month, in both groups left PUUO was created. Renal Doppler USG was performed to measure RI and PI parameters of both kidneys on the 4th hour and 1st and 3rd days postoperatively. Results: Baseline renal Doppler USG revealed that there was no difference between two kidneys in both groups. The differences in mean RI and PI values of the kidneys between the sham and tadalafil groups were not statistically significant. Compared with the preoperative values, postoperative RI and PI values for the left kidneys were significantly increased in the period from 4 h to 3 days postoperatively in the sham group (p < 0.05). However, mean RI and PI values were not increased in the tadalafil group when compared with the sham group and this difference between the two groups was significant (p < 0.05). Conclusions: Tadalafil has a lowering affect on RI and PI in experimentally created PUUO.