Ototoxicity of boric acid powder in a rat animal model / Ototoxicidade de ácido bórico em pó em um modelo animal de rato

Abstract Introduction: Boric acid, which has antiseptic and acidic properties, is used to treat external and middle ear infections. However, we have not found any literature about the effect of boric acid powder on middle ear mucosa and inner ear. Objective: The purpose of this study is to investigate possible ototoxic effects of boric acid powder on cochlear outer hair cell function and histological changes in middle ear mucosa in a rat animal model. Methods: Twenty healthy, mature Wistar albino rats were used in this study. The rats were divided into two groups, Group A and Group B, each of which consisted of 10 rats. Initially, the animals in each group underwent distortion product otoacoustic emissions testing of their right and left ears. After the first distortion product otoacoustic emissions test, a surgical microscope was used to make a small perforation in both ears of the rats in each group, and a second distortion product otoacoustic emissions test was used to measure both ears in all of the rats. Boric acid powder was applied to the right middle ear of the rats using tympanic membrane perforation, and the distortion product otoacoustic emissions were measured immediately after the boric acid powder application. The histological changes and distortion product otoacoustic emissions were evaluated three days later in Group A and 40 days later in Group B. Results: No significant differences were found at all of the distortion product otoacoustic emissions frequencies. In Group A, mild inflammation of the middle ear mucosa was found on the third day after boric acid powder application. In Group B, boric acid powder caused mild inflammatory changes on the 40th day, which declined over time. Those changes did not lead to significant fibrosis within the mucosa. Conclusion: In rats, boric acid powder causes mild inflammation in middle ear mucosa and it has no ototoxic effects on cochlear outer hair cell function in the inner ear of rats.

Resumo Introdução: O ácido bórico, que tem propriedades antissépticas e ácidas, é usado para tratar infecções de orelha externa e média. No entanto, não encontramos literatura sobre o efeito do ácido bórico em pó sobre a mucosa da orelha interna e da orelha média. Objetivo: Investigar possíveis efeitos ototóxicos do ácido bórico em pó sobre a função das células ciliadas externas cocleares e alterações histológicas na mucosa da orelha média em um modelo animal de rato. Método: Vinte ratos Wistar albinos maduros e saudáveis foram usados neste estudo. Os ratos foram divididos em dois grupos, Grupo A e Grupo B, cada um dos quais com 10 ratos. Inicialmente, os animais de cada grupo foram submetidos a testes de emissões otoacústicas - produto de distorção, nas orelhas direita e esquerda. Após o primeiro teste de emissões otoacústicas - produto de distorção, utilizou-se um microscópio cirúrgico para fazer uma pequena perfuração em ambas as orelhas dos ratos em cada grupo, e um segundo teste de emissões otoacústicas - produto de distorção foi utilizado para medir e avaliar as orelhas em todos os ratos. O ácido bórico em pó foi aplicado na orelha média direita dos ratos utilizando perfuração da membrana timpânica e as emissões otoacústicas - produto de distorção foram medidas imediatamente após a aplicação de ácido bórico em pó. As alterações histológicas e emissões otoacústicas - produto de distorção foram avaliadas três dias depois no Grupo A e 40 dias depois no Grupo B. Resultados: Não foram encontradas diferenças significativas em todas as frequências da emissões otoacústicas - produto de distorção. No Grupo A, foi observada uma ligeira inflamação da mucosa da orelha média no terceiro dia após a aplicação de ácido bórico em pó. No Grupo B, o ácido bórico em pó causou leves alterações inflamatórias após 40 dias, que diminuíram ao longo do tempo. Essas alterações não levaram à fibrose significativa da mucosa. Conclusão: Em ratos, o ácido bórico em pó causa inflamação leve na mucosa da orelha média e não tem efeitos ototóxicos na função das células ciliadas externas da cóclea na orelha interna.

A New Centrifugation Method for the Improvement of Platelet-rich Fibrin Products: A Preliminary Study.

Introduction: Nowadays, there are many articles about Platelet Rich Plasma/Platelet Rich Fibrin families. A novel platelet-rich product called titanium prepared platelet-rich fibrin (T-PRF) has stronger and thicker fibrin than that of the classic glass tube prepared platelet-rich fibrin. Strong fibrin structure is important to extend the time for resorption of fibrin in-vivo, and increase the release time of growth factors. Objective: In this preliminary study of a new centrifugation method, we aimed to change the direction of fibrin formation during the platelet aggregation, and make T-PRF much denser and more resistant. According to our hypothesis, it can make it possible to use in guided bone, and guided tissue regeneration more successfully. Methods: Blood samples of 10 healthy male volunteers were collected, and four 10ml blood samples, one for each of four groups, were transferred to a Ti tube from each volunteer. The first group was centrifuged for a 20-minute period clockwise (T-PRF group), and the other groups were centrifuged for a total of 20 minutes with two-minute (2min MT-PRF group), five-minute (5 min MT-PRF group), and ten-minute (10min MT-PRF group) periods clockwise and counter-clockwise. Results: By hematoxylin and eosin stain, the 10min MT-PRF group showed a better-organized network with continuous integrity compared to the other groups. With the immunofluorescent staining, fibrin seemed thicker and better organized in the 10 min MT-PRF group. SEM examination showed more complex and denser fibrin clusters in the 10 min MT-PRF group than the other groups. Conclusion: This pilot study defines 10 min MT-PRF as a new autogenous product with superior fibrin network. Our results showed that, fibrin formation was made more organised and denser with 2-way direction centrifugation.

Remifentanil protects uterus against ischemia-reperfusion injury in rats

PURPOSE: To investigate the effects of remifentanil as an antioxidant and analyze the histopathologic, biochemical changes in experimental ischemia-reperfusion (I/R) exposed rat uteri. METHODS: Wistar albino rats were assigned to three groups (n = 7). 2h period of ischemia was followed by 1h of reperfusion in the I/R and the I/R-remifentanil groups. After ischemia, no drug was administered in the sham and I/R groups. In the I/R-remifentanil group, remifentanil infusion (2 μg/kg/min) was started in the ischemia period, and continued until the end of reperfusion. After the ischemic and reperfusion period, the ischemic uterine horns were removed surgically for biochemical and histopathologic examination. Tissue damage scores (endometrial epithelial glandular leukocytosis, degeneration, and endometrial stromal changes) were examined. Malondialdehyde levels and catalase, superoxide dismutase enzyme activities in tissue were measured. RESULTS: We found significantly lower epithelial leukocytosis and cell degeneration in the I/R-remifentanil group (p<0.05). Remifentanil administration significantly decreased concentrations of malondialdehyde, and increased catalase and superoxide dismutase enzyme activities (p<0.05). CONCLUSION: Remifentanil appears to protect the uterine tissue against ischemia-reperfusion and can be used safely in uterus transplantation.

BRAF, KIT, NRAS, GNAQ and GNA11 mutation analysis in cutaneous melanomas in Turkish population.

Background: KIT and mitogen-activated protein kinase cascade are important for melanomagenesis. In the present study, we analyzed the frequency of BRAF, NRAS, KIT, GNAQ and GNA11 gene mutations and investigated their association with clinicopathological features of melanomas in Turkish population. Materials and Methods: Forty-seven primary cutaneous melanomas were included in our study. Sanger sequencing method was used for mutation analysis in all cases. Results: Mean age was 62.1 (29-101) years. Female:male ratio was 17:30. Among 47 melanomas, 14 (29.8%) BRAF, 10 (21.3%) NRAS, 4 (8.5%) KIT and 1(2.1%) GNAQ gene mutations were detected. Two of the KIT mutations were found in acral lentiginous melanoma (ALM). In the head and neck region, mutation frequency was signifi cantly lower than in other locations (P = 0.035). The only GNAQ gene mutation (p.Q209L) was detected in a melanoma arising from blue nevus located on the scalp. None of the melanomas harbored NRAS exon 2, KIT exon 13/17/18, GNAQ exon 4 and GNA11 exon 4/5 mutations. Overall mutation frequency did not show signifi cant difference between metastatic (8/14, 57.1%) and nonmetastatic (18/33, 54.5%) patients. We did not observe any signifi cant association between mutation status and gender or age of various patients. Conclusions: Our results support that BRAF and NRAS gene mutations are common in cutaneous melanomas. The activating mutations of KIT gene are rare and especially seen in ALM. GNAQ and GNA11 mutations are infrequent in cutaneous melanomas and may be associated only with melanomas arising from blue nevus.

Adhesion-preventing properties of 4% icodextrin and canola oil: a comparative experimental study

OBJECTIVE: Postsurgical abdominal adhesions are common, serious postoperative complications. The present study compared the usefulness of 4% icodextrin and canola oil in preventing postoperative peritoneal adhesions. METHODS: Twenty-four Wistar albino rats were divided into three groups. Following a laparotomy, a serosal abrasion was made by brushing the cecum, and 3 mL of 0.9% NaCl, 4% icodextrin, or 3 mL of canola oil were intraperitoneally administered for the control, icodextrin, and canola oil groups, respectively. The abdomen was then closed. All of the rats were sacrificed at day 10. Macroscopic, histopathological, and biochemical evaluations were performed. The results were statistically analyzed using Kruskal-Wallis and ANOVA tests. RESULTS: Macroscopic analyses revealed that both canola oil and 4% icodextrin reduced adhesion formation, but the difference was not statistically significant (p = 0.17). The histopathological examinations revealed no significant differences in terms of giant cell, lymphocyte/plasmocyte, neutrophil, ICAM1, or PECAM1 scores. However, both canola oil and 4% icodextrin significantly reduced fibrosis (p = 0.025). In the canola oil group, the histiocytic reactions were significantly increased (p = 0.001), and the hydroxyproline levels were significantly lower than those in the other groups (p = 0.034). CONCLUSIONS: In the present study, canola oil was determined to be superior to 4% icodextrin in lowering hydroxyproline levels and increasing histiocytic reactions. Considering these results, we believe that canola oil is a promising agent for preventing adhesion formation.