A meta-analysis review of revision stapes surgery with argon laser: effectiveness and safety.

OBJECTIVE: To determine whether there is an advantage in safety and outcome efficacy with the use of argon laser in revision stapes surgery as compared with conventional instruments. DATA SOURCES: A search of the published English-language literature, 1970-1995, was conducted using the following key words: revision, surgery, stapes, laser, stapedotomy, and argon laser. STUDY SELECTION: The following inclusion criteria were used to select articles for the meta-analysis: revision cases only, a comprehensive review of intraoperative pathological findings that led to the failure, and accurate documentation by the author, confirmed by our statisticians using a modified chi 2 test. Eleven studies without the use of the laser (n = 1,147 patients) and four studies with the use of the laser (n = 170 patients) including our own patients (n = 23) were entered into the model. DATA EXTRACTION: The data had to meet strict audiometric criteria, including preoperative and postoperative audiogram pure tone average air-bone gap; postoperative audiograms had to include five classifications, and these audiograms had to be obtained a minimum of 6 months after revision surgery. DATA SYNTHESIS: A log-linear model was developed for this meta-analysis study, with each study analyzed individually and collectively. CONCLUSION: Revision stapes surgery using the laser demonstrated statistically significant (p = 0.002) advantage in both safety and efficacy over revision procedures using conventional instruments

Attenuation of kindled seizures by intranasal delivery of neuropeptide-loaded nanoparticles.

Thyrotropin-releasing hormone (TRH; Protirelin), an endogenous neuropeptide, is known to have anticonvulsant effects in animal seizure models and certain intractable epileptic patients. Its duration of action, however, is limited by rapid tissue metabolism and the blood—brain barrier. Direct nose-to-brain delivery of neuropeptides in sustained-release biodegradable nanoparticles (NPs) is a promising mode of therapy for enhancing CNS neuropeptide bioavailability. To provide proof of principle for this delivery approach, we used the kindling model of temporal lobe epilepsy to show that 1) TRH-loaded copolymer microdisks implanted in a seizure focus can attenuate kindling development in terms of behavioral stage, after-discharge duration (ADD), and clonus duration; 2) intranasal administration of an unprotected TRH analog can acutely suppress fully kindled seizures in a concentration-dependent manner in terms of ADD and seizure stage; and 3) intranasal administration of polylactide nanoparticles (PLA-NPs) containing TRH (TRH-NPs) can impede kindling development in terms of behavioral stage, ADD, and clonus duration. Additionally, we used intranasal delivery of fluorescent dye-loaded PLA-NPs in rats and application of dye-loaded or dye-attached NPs to cortical neurons in culture to demonstrate NP uptake and distribution over time in vivo and in vitro respectively. Also, a nanoparticle immunostaining method was developed as a procedure for directly visualizing the tissue level and distribution of neuropeptide-loaded nanoparticles. Collectively, the data provide proof of concept for intranasal delivery of TRH-NPs as a viable means to 1) suppress seizures and perhaps epileptogenesis and 2) become the lead compound for intranasal anticonvulsant nanoparticle therapeutics

Compromised osseous healing of dental extraction sites in zoledronic acid-treated dogs

Summary: The goal of this study was to document how treatment with high doses of zoledronic acid affects dental extraction healing. Our results, showing significantly compromised osseous healing within the socket as well as presence of exposed bone and development of a sequestrum in one animal, provide a building block toward understanding osteonecrosis of the jaw. Purpose: The goal of this study was to document how treatment with a bisphosphonate affects the bone tissue following dental extraction. Methods: Skeletally mature female beagle dogs were either untreated controls (CON) or treated with intravenous zoledronic acid (ZOL). Following the extraction of the fourth premolars, healing was allowed for 4 or 8 weeks. Properties of the extraction site were assessed using microcomputed tomography (micro-CT) and dynamic histomorphometry. Results: The initial infilling of the extraction socket with bone was not affected by ZOL, but subsequent removal of this bone was significantly suppressed compared to CON. After 8 weeks of healing, the alveolar cortical bone adjacent to the extraction socket had a remodeling rate of ∼50% per year in CON animals while ZOL-treated animals had a rate of \u3c1% per year. One ZOL-treated animal developed exposed bone post-extraction which eventually led to the formation of a sequestrum. Assessment of the sequestrum with micro-CT and histology showed that it had features consistent with those reported in humans with osteonecrosis of the jaw. Conclusions: These results, showing significantly compromised post-extraction osseous healing as well as presence of exposed bone and development of a sequestrum in one ZOL animal, provide a building block toward understanding the pathophysiology of osteonecrosis of the jaw. © 2010 International Osteoporosis Foundation and National Osteoporosis Foundation