Flavia Coelho de Souza

Bacterial cellulose as laryngeal medialization material: an experimental study.

HYPOTHESIS The use of a material made of bacterial cellulose with the aim of obtaining vocal fold medialization has not hitherto been fully investigated. Although the material has been tested in other animal models, the evaluation did not include the larynx; hence, situations, such as tissue reaction, material absorption, and extrusion, need to be addressed to evaluate its usefulness as a material for laryngeal reconstruction. OBJECTIVE To evaluate the medialization, tissue response, and healing of rabbit vocal folds, after the implantation of a membrane of bacterial cellulose. STUDY DESIGN Experimental study. METHODS A total of 32 rabbits were used, two of which were used to check out the adequacy of the implant location. The animals were followed for 4 months and grouped according to follow-up times of 2, 4, and 16 weeks. All test animals received an implant of bacterial cellulose in one vocal fold and the injection of distilled water in the other, both performed by videoendoscopic cervicotomy. At the end of the follow-up, the presence of inflammatory and medial displacement was evaluated. RESULTS No statistically significant difference in the inflammatory parameters between the study and control vocal folds or among follow-up times was found. All animals receiving cellulose presented medial displacement of vocal folds, and all retained this material at the implant site up to study endpoint. CONCLUSION Bacterial cellulose is a useful material for laryngeal medialization, showing no signs of rejection or absorption.

Experimental study of the tissue reaction caused by the presence of cellulose produced

Summary Several materials have been proposed for nasal reconstruction. There is no consensus on which is the best. The cellulose blanket produced by bacteria may be a possible cartilaginous addition element to the nose. Aim to study tissue reaction to cellulose in the dorsal nose of rabbits. Materials and Methods 22 New Zealand rabbits were used. In 20 a cellulose blanket was implanted in the nasal dorsum and 2 served as controls. They were followed up through a period of three and six months, after which their nostrils and nasal dorsums were removed and histological studies were carried out on them, considering defined parameters of inflammation such as vascular congestion, intensity of the inflammatory process and presence of purulent exudate. Results The inflammatory process remained stable, showing its relationship with the surgical procedure and not with the presence of the cellulose blanket. There were no statistical differences in the other parameters. Conclusion The cellulose blanket produced by Acetobacter xylinum presented good biocompatibility, remained stable during the entire study period, and could be considered a good material for elevating the nasal dorsum.

Experimental study of the tissue reaction caused by the presence of cellulose produced by Acetobacter Xylinum in the nasal dorsum of rabbits

UNLABELLED Several materials have been proposed for nasal reconstruction. There is no consensus on which is the best. The cellulose blanket produced by bacteria may be a possible cartilaginous addition element to the nose. AIM to study tissue reaction to cellulose in the dorsal nose of rabbits. MATERIALS AND METHODS 22 New Zealand rabbits were used. In 20 a cellulose blanket was implanted in the nasal dorsum and 2 served as controls. They were followed up through a period of three and six months, after which their nostrils and nasal dorsums were removed and histological studies were carried out on them, considering defined parameters of inflammation such as vascular congestion, intensity of the inflammatory process and presence of purulent exudate. RESULTS The inflammatory process remained stable, showing its relationship with the surgical procedure and not with the presence of the cellulose blanket. There were no statistical differences in the other parameters. CONCLUSION The cellulose blanket produced by Acetobacter xylinum presented good biocompatibility, remained stable during the entire study period, and could be considered a good material for elevating the nasal dorsum.

Comparative study of several sinusitis experimental modelling techniques in rabbits.

UNLABELLED Experimental models for clinical studies of rhinosinusitis are needed. AIM to define a reliable, solid and reproducible experimental model for inflammatory rhinosinusitis with no innoculation of infectious agents in rabbits. STUDY DESIGN Experimental. MATERIAL AND METHOD Twenty 20 rabbits were divided into 4 groups submitted to 4 different interventions: the placement of a unilateral nasal fossa sponge, unilateral obliteration of the nasal ostium with cyanoacrylate, unilateral placement of antigens in the maxillary cavity and unilateral placement of blood in the maxillary cavity. The animals were monitored for 15 days and then anesthetized and sacrificed; the maxillary sinuses were evaluated histologicaly and results were compared with controls and between the intervention groups. CONCLUSION Sponje and glue as agents of meatal obstruction and toxoid applied in the antrum are efficient as methods for rhinosinusitis modeling. Blood was not efficient in producing sinusitis.

Estudo comparativo entre diversas técnicas de confecção de modelo experimental de sinusite inflamatória em coelhos

Experimental models for clinical studies of rhinosinusitis are needed. AIM: to define a reliable, solid and reproducible experimental model for inflammatory rhinosinusitis with no innoculation of infectious agents in rabbits. Study design: Experimental. MATERIAL AND METHOD: Twenty 20 rabbits were divided into 4 groups submitted to 4 different interventions: the placement of a unilateral nasal fossa sponge, unilateral obliteration of the nasal ostium with cyanoacrylate, unilateral placement of antigens in the maxillary cavity and unilateral placement of blood in the maxillary cavity. The animals were monitored for 15 days and then anesthetized and sacrificed; the maxillary sinuses were evaluated histologicaly and results were compared with controls and between the intervention groups. CONCLUSION: Sponje and glue as agents of meatal obstruction and toxoid aplied in the antrum are efficient as methods for rhinosinusitis modeling. Blood was not efficient in producing sinusitis.

Influence of selant fibrin on the wound healing of the pigs vocal folds

UNLABELLED Fibrin sealants or fibrin glue are products made from human plasma proteins, which mimic the final pathway of the coagulation cascade. Its application to stimulate the healing process has been a topic of debate in the literature. The use of fibrin sealants in phonosurgery has been empirical; there have been no studies that investigate the action of fibrin sealant in Reinkes space. AIM To evaluate the effect of fibrin glue in healing of the vocal folds of pigs after surgical manipulation. MATERIALS AND METHODS This was a prospective and experimental study. Six animals had both vocal folds incised. Sealant was applied in one of them; the other served as a control. After three months, the animals were sacrificed and a collagen count was carried out. RESULTS The side on which glue was applied had an average of 27.8% against 20.4% of the side without glue. CONCLUSION The collagen concentration in the samples where the fibrin sealant was applied was significantly higher compared to samples without glue. Thus, the presence of a fibrin sealant stimulates fibrogenesis in this tissue.

Tracheal inflammatory response to bacterial cellulose dressing after surgical scarification in rabbits

UNLABELLED Exuberant scarring tissue formation is among the failure causes of tracheal stenosis surgery. Dressings that could avoid such reaction could be very helpful in these cases. Bacterial cellulose, produced by acetobacter xylinun can be useful in these cases. There are no studies in the laryngotracheal region. AIM To assess subglottic tissue response in rabbits after scarification and placement of cellulose dressing, and comparing it to a control group. STUDY DESIGN Experimental. MATERIALS AND METHODS 26 rabbits underwent laryngotracheal scarification, received the dressing and were compared to the control group. We established four follow up periods. Laryngotracheal specimens underwent histological exam and the results were statistically assessed. RESULTS The study group had statistically similar results when compared to the control group in the following parameters: vascular congestion, purulent oozing, acute inflammation, epithelial integrity, fibrous proliferation and granulous proliferation. CONCLUSION We did not observe differences between the study and control groups as far as inflammation and scarring are concerned. There were no inflammatory signs associated with the use of the cellulose membrane that did no occur because of surgery.

Avaliação da resposta inflamatória traqueal ao curativo de celulose bacteriana após escarificação cirúrgica em coelhos

Exuberant scarring tissue formation is among the failure causes of tracheal stenosis surgery. Dressings that could avoid such reaction could be very helpful in these cases. Bacterial cellulose, produced by acetobacter xylinun can be useful in these cases. There are no studies in the laryngotracheal region. AIM: to assess subglottic tissue response in rabbits after scarification and placement of cellulose dressing, and comparing it to a control group. STUDY DESIGN: experimental. MATERIALS AND METHODS: 26 rabbits underwent laryngotracheal scarification, received the dressing and were compared to the control group. We established four follow up periods. Laryngotracheal specimens underwent histological exam and the results were statistically assessed. RESULTS: the study group had statistically similar results when compared to the control group in the following parameters: vascular congestion, purulent oozing, acute inflammation, epithelial integrity, fibrous proliferation and granulous proliferation. CONCLUSION: we did not observe differences between the study and control groups as far as inflammation and scarring are concerned. There were no inflammatory signs associated with the use of the cellulose membrane that did no occur because of surgery.

Preclinical evaluation of Luffa operculata Cogn. and its main active principle in the treatment of bacterial rhinosinusitis

INTRODUCTION The prevalence of rhinosinusitis is quite high. Despite the widespread use of antibiotics for rhinosinusitis, there are other forms of treatment, including phytotherapy. One of the most widely used herbal medicines for treatment of rhinosinusitis is Luffa operculata. OBJECTIVE This study aimed to evaluate the efficacy of topical nasal solution of the aqueous extract of L. operculata, determining the toxicity to its use and identifying the active principles presented in the aqueous extract. The secondary objective was to evaluate the action of active principles on bacteria commonly involved in acute rhino sinusitis. METHODS The study was conducted in experimental model of sinusitis. Three different concentrations of L. operculata were used as local treatment of rhino sinusitis. The results were compared with those observed in control groups that received nasal saline solution. Histological examination of the liver, kidney, spleen, myocardium, brain and lungs of all animals evaluated the toxicity of L. operculata. The aqueous extract used was subjected to chromatographic analysis and an active principle was isolated and tested for in vitro inhibition of bacterial colonies usually found in rhino sinusitis. RESULTS Intranasal treatment of sinusitis with L. operculata showed better clinical evolution than control group. Statistically significant difference (p>0.10) between the treated group and the control group was observed in the histologic evaluation for inflammatory pattern. The aqueous extract of L. operculata used presented a predominance of 2,3-dicafeoilglicaric acid, a substance not yet described in the literature. There was a significant difference in bacterial growth of Streptococcus pyogenes on blood-agar plates when under the influence of both the aqueous extract and the active substance. CONCLUSION Topical nasal solution of the aqueous extract of L. operculata is effective compared to the application of saline solution for the treatment of bacterial rhinosinusitis in an experimental model. L. operculata determined in vitro inhibition of growth of S. pyogenes.