Potential protective effect of N-acetyl cysteine in acoustic trauma: An experimental study using scanning electron microscopy.

BACKGROUND: Oxidative stress has been associated with pathological processes involved in acoustic trauma. OBJECTIVES: In this prospective experimental study, we investigated the potential preventive effect of N-acetyl cysteine (NAC) in rats exposed to acoustic trauma (AT). Light microscopic and scanning electron microscopic (SEM) evaluations were performed. MATERIAL AND METHODS: Healthy Wistar albino rats (n = 18) were divided into 3 groups: group 1 (control group, n = 6), group 2 (acoustic trauma group, n = 6), and group 3 (AT+NAC group, n = 6). The rats in group 2 were exposed to AT. The rats in group 3 received NAC at a dose of 100 mg/kg/day by gavage for 7 days, and then 10 min after the 7th-day dose, they were exposed to AT. RESULTS: From light and scanning electron microscopy evaluations in the control group, the cochlear structure and epithelium were normal. In group 2 (AT group), extensive hair cell loss was observed in the cochlea by light microscopy evaluation. In the SEM evaluation, various epithelial damage and loss of stereocilia were also observed. In group 3 (AT+NAC group), decreased damage with preserved cochlear structures was seen by light microscopy. In the SEM evaluation, although stereocilia loss was also seen, nearly normal cell structures and vertical and symmetrical alignment of stereocilia structures were observed compared to the AT group. CONCLUSIONS: NAC reduced cochlear damage due to acoustic trauma. Because NAC has antioxidant capacity, AT mat have caused an increase in free radicals and death of outer hair cells. NAC is an antioxidant agent and it prevented cochlear damage due to AT in rats.

Nasal tip sutures: Techniques and indications.

OBJECTIVES: The surgical anatomy of the nasal tip is determined by intrinsic factors, such as the nasal tip volume, shape, definition, and symmetry. These factors are intimately related to the morphology of the lower lateral cartilages. Tip sutures reduce the need for grafts and allow the surgeon to manipulate the tip with a high degree of precision and better long-term clinical outcomes. In this review, we evaluated common nasal tip suture techniques to clarify the similarities and differences among them. METHODS: The following nasal tip suture techniques were investigated: medial crural fixation suture, middle crura suture, transdomal (dome creating, dome binding, domal definition) suture, interdomal suture, lateral crural mattress suture, columella septal suture, intercrural suture, tip rotation suture, craniocaudal transdomal suture, lateral crural spanning suture, suspension suture, tongue-in-groove technique, and lateral crural steal. RESULTS: Tip sutures increase tip projection, narrow the tip, provide stabilization, and provide tip rotation. The sutures may be used separately or together. CONCLUSION: Nasal tip sutures have long been used as noninvasive suture techniques. Each suture technique has unique benefits, and various key points must be considered when using these techniques.