The Effect of Slime Factor in the Treatment of Spinal Implant Infections.

AIM: To investigate the effect of the biofilm-forming ability of the bacteria on treatment in rats by using biofilm-forming and nonbiofilm- forming strains of Staphylococcus aureus (S. aureus). MATERIAL AND METHODS: Forty rats were divided into four equal groups as Group 1A, 1B, 2A, and 2B. All rats underwent single distance lumbar laminectomy, and titanium implants were introduced. Group 1 rats were inoculated with Slime factor (-) S. aureus, while Group 2 rats were inoculated with biofilm Slime factor (+) S. aureus. None of the rats were given antibiotics. One week later, the surgical field was reopened and microbiological samples were taken. The implants of rats in Groups 1A and 2A were left in place, while the implants of rats in Groups 1B and 2B were removed. RESULTS: There was no statistically significant difference between the groups inoculated with slime factor (+) S. aureus; although, Groups 1A and 2A showed statistically significant difference. Statistical analysis with respect to bacterial count also showed a statistically significant difference between Groups 1A and 2A. There was a statistically significant difference between Group 1B and 2B. CONCLUSION: The results obtained in the present study reveal that in case of implant-dependent infection, the first sample taken can be checked for slime factor, and if there is infection with slime factor-negative bacterium, treatment without removing the implant may be recommended. S. aureus was used in the study because it is the most common cause of implant-related infection at surgical sites. Further studies using different bacterial species are needed to reach a definitive conclusion.

The Preventive Effect of Systemic Honokiol and Systemic Pentoxifylline on Epidural Fibrosis.

AIM: To investigate the preventive effects of systemic honokiol and pentoxifylline treatments on epidural fibrosis (EF) in the experimental laminectomy model. MATERIAL AND METHODS: Thirty-two rats were divided into four equal groups. Laminectomy was performed in all rats except for the control group. One group was kept as the negative control group. Moreover, 10 mg/kg pentoxifylline and 10 mg/kg honokiol were administered intraperitoneally for 5 days, respectively, to the other two groups. The rats were sacrificed after 4 weeks. The samples were examined biochemically in terms of oxidative stress and inflammation induced by tissue damage. Histopathological and immunohistochemical investigations were also performed to detect EF severity. RESULTS: In honokiol and pentoxifylline groups compared with the negative control group, tumor necrosis factor-beta and interleukin-10 levels (indicating inflammation); myeloperoxidase, malondialdehyde, and hydroxyproline levels (indicating oxidative stress); and intercellular adhesion molecule levels (indicating fibrosis) were decreased. Histopathologically and immunohistochemically, EF was significantly reduced in the pentoxifylline and honokiol groups. Biochemical findings were consistent with the histopathological and immunohistochemical findings. CONCLUSION: Both pentoxifylline and honokiol prevent EF formation. However, this effect is more pronounced in honokiol.

Is Placing Prophylactic Dural Tenting Sutures a Dogma?

OBJECTIVE: In this study, we investigated if and when dural tenting sutures are necessary during craniotomy. METHODS: Results from 437 patients 18-91 years of age (average, 43.5 years) who underwent supratentorial craniotomy between 2014 and 2019 were evaluated. The patients were categorized into 1 of 3 groups: patients who had at least 3 prophylactic dural tenting sutures placed before opening of the dura (group 1); patients who had at least 3 dural tenting sutures placed after surgery was completed, during closure (group 2); or patients who had no dural tenting sutures (group 3 [control]). All such sutures in groups 1 and 2 were placed in the circumference of the craniotomy and dural junction. No central dural tenting sutures were placed in any of the patients. RESULTS: Among the 437 patients, 344 underwent surgery for the first time and 93 were undergoing a second surgery. Cranial computed tomography imaging was performed for each patient 1 hour, 3 days, and 1 month after surgery. In group 1, 3 patients had a cerebral cortex contusion and 2 patients had acute subdural hematoma after the sutures were placed. In groups 2 and 3, none of the patients had a cerebral cortex contusion or acute subdural hematoma. Fewer complications were observed when dural tenting sutures were placed during postsurgical closure. CONCLUSIONS: Placing dural tenting sutures is an important technique for ensuring hemostasis. However, when not needed, they seem to cause inadvertent complications. As our results suggest, knowing when and where to use them is equally important.

Pregabalin does not Cause Midline Closure Defect but is not as Innocent as It is Thought.

AIM: To investigate the effects of pregabalin on neural tube closure, and other potential effects on other organ systems in a chick embryo model. MATERIAL AND METHODS: Fertilized chicken eggs were divided into groups, and different doses of pregabalin was administered. All embryos were harvested in the 8th day of incubation, and investigated both macroscopically and microscopically against any developmental malformations caused by Pregabalin. RESULTS: Macroscopically not any malformations were detected but macrosomia was statistically significant in medium and high dose groups. Microscopically, vertebral lamina ossification was delayed in some embryos in high dose group but not interpreted as midline closure defect and also not statistically significant. Decrease in the number of renal glomerulus and increase in the tubular damage was statistically significant in medium and high dose groups. Cardiomegaly was also found in some embryos in middle and high dose groups but not statistically significant. CONCLUSION: The use of pregabalin does not cause neural tube closure defect in the embryo unless not exceed recommended maximum dose. Causing macrosomia instead of developmental retardation by Pregabalin is in conflict with the literature. This study revealed that Pregabalin causes fetal nephrotoxicity and macrosomia. These findings indicate that the use of Pregabalin in pregnancy still needs to be accounted as suspicious.

Nanoparticle silver ion coatings inhibit biofilm formation on titanium implants.

The formation of bacterial biofilm on the surface of implanted metal objects is a major clinical problem. The antibacterial and antifungal effect of silver ions has been long known, and seems to give silver the capability to inhibit biofilm formation. To test the effect of silver ions, 20 New Zealand rabbits had bacteria applied to a screw insertion site at the iliac crest, and were then randomly divided into two groups: Group I, which had silver-coated screws applied, and Group II, which had uncoated titanium screws. After the rabbits were sacrificed on day 28, we examined the screws, the bone adjacent to the screws, and the liver, kidneys, brain and corneas of both groups under transmission (TEM) and scanning electron microscopy (SEM). We also analysed microbiological samples from the screw holes. All silver-coated screws, but only 10% of uncoated titanium screws, were sterile. All tissue samples appeared ultrastructurally normal in both groups. Biofilm formation was inhibited on all silver-coated screws, but all uncoated screws developed a biofilm on their surfaces. Our findings suggest that nanoparticle silver ion-coated implants are as safe as uncoated titanium screws and that they can help prevent both biofilm formation and infection.

Antibacterial effects of electrically activated vertebral implants.

Bio-implants in the human body act as passive surfaces that are prone to bacterial adhesion potentially leading to deep body infections. Pedicle screws made of uncoated or silver-coated titanium alloy were used both in vitro and in vivo to determine whether silver-coated materials have antimicrobial properties when they are anodized. Twenty-four New Zealand Albino rabbits were divided into four groups with six in each. In Group 1, the rabbits were exposed to 8 muA direct current (DC) via silver-coated screws. In Group 2, the rabbits were not exposed to any electrical current, but silver-coated screws were used. In Group 3, the rabbits were exposed to 8 muA DC using uncoated screws. In Group 4, the rabbits were not exposed to any electrical current, but uncoated screws were used. Staphylococcus aureus (106 cfu) was inoculated into the rabbits before any electrical current was applied. All the animals were killed, and the areas surrounding the screws were histologically and microbiologically examined. Silver-coated titanium screws prevented implant-associated deep bone infections when they were polarized anodically. The antibacterial effects of the same screws with the same bacterium were confirmed in in vitro experiments on agar plates. When the screws were anodized with the same electrical parameters in vitro, a marked inhibition zone was detected around the silver-coated screws but not around the uncoated screws. Our findings suggest that silver-coated titanium implants can be used to prevent implant-associated deep bone infections when they are polarized anodically.