Miguel Angelo Hyppolito

Miringoplastia com a utilização de um novo material biossintético

Myringosplaty is a surgery that is performed to control infections in middle ear, to reconstruct the sound conducting mechanism for the oval window and protection of the round window. Some materials are used to reconstruct the tympanic membrane like autologous temporalis fascia, cartilage-perichondium graft taken from the tragus, cartilage only, dura mater human placental graft. It is important the vascular support to the graft with well-vascularized flap in wide perforations. AIM: The main goal of this work is shown the use of a new biomaterial, the natural latex membrane with polylysin. STUDY DESIGN: Longitudinal Cohort. MATERIAL AND METHOD: This material was developed from Department of Biochemistry from Faculdade de Medicina de Ribeirao Preto Universidade de Sao Paulo. The natural latex membrane is used stimulating neovessels and organized tecidual growing in different parts and tissues of the human body. This material promotes any allergic reaction and is innocuous to the human tissue. The 238 ears with tympanic membrane perforation resulted from chronic middle ear infection and thek was going through myringoplasty with autologous temporalis fascia and natural latex membrane. The ages were 7 to 76 years. RESULTS: The first results show 181 (90,5%) healing tympanic membrane perforation, 96 healing of wide perforation 73 medium perforation and 12 small one. Neovessels could be seen in all grafts and remaining tympanic membrane. This is not a habitual funding when the natural latex membrane is not used. CONCLUSION: According to these results we can conclude that the natural latex membrane can be used as a temporary implant in myringoplasty, improving the well vascularized of remaining tympanic membrane.

Mechanisms of cisplatin ototoxicity: theoretical review

INTRODUCTION Cisplatin is an effective chemotherapeutic agent commonly used in the treatment of malignant tumours, but ototoxicity is a significant side effect. OBJECTIVES To discuss the mechanisms of cisplatin ototoxicity and subsequent cell death, and to present the results of experimental studies. MATERIAL AND METHODS We conducted a systematic search for data published in national and international journals and books, using the Medline, SciELO, Bireme, LILACS and PubMed databases. RESULTS The nicotinamide adenine dinucleotide phosphate oxidase 3 isoform (also termed NOX3) seems to be the main source of reactive oxygen species in the cochlea. These reactive oxygen species react with other molecules and trigger processes such as lipid peroxidation of the plasma membrane and increases in expression of the transient vanilloid receptor potential 1 ion channel. CONCLUSION Cisplatin ototoxicity proceeds via the formation of reactive oxygen species in cochlear tissue, with apoptotic cell death as a consequence.

Conhecimento da anatomia da orelha de cobaias e ratos e sua aplicação na pesquisa otológica básica

O uso de mostras animais e importante na pesquisa otologica e o conhecimento da anatomia de sua orelha permite sua utilizacao adequada. OBJETIVO: Estudar a anatomia da orelha da cobaia e do rato por microscopia optica de luz (MOL) e microscopia eletronica de varredura (MEV) e suas vantagens anatomicas na pesquisa otologica basica. MATERIAL E METODO: Os ossos temporais, as bulas timpânicas e cocleas de tres cobaias e ratos albinos foram fotografados e analisados ao MOL e MEV. RESULTADOS: O rato nao e tao simples de manipular como a cobaia, e frequentemente apresenta otite media. O rato apresenta uma juncao fragil da bula timpânica, duas e meia espiras na coclea e a membrana timpânica nao veda todo o conduto auditivo externo. A cobaia possui uma bula inteirica, martelo e bigorna fundidos e tres e meia espiras na coclea. Pela MEV a cobaia e o rato possuem Membrana Tectoria, Membrana de Raissner e o Orgao de Corti. As Celulas de Hensen estao presentes somente na cobaia. CONCLUSAO: A cobaia foi considerada de facil manipulacao para a microdisseccao, pelo tamanho e rigidez do osso temporal, e para experimentos cirurgicos envolvendo o estribo, janela oval e a membrana timpânica. Pela MEV nota-se semelhanca entre cobaia e rato, podendo ambos serem utilizados em estudos da orelha interna.

Gentamicin Attenuates Gentamicin-Induced Ototoxicity - Self-Protection

Aminoglycoside antibiotics cause considerable toxicity to the inner ear. A progressive hearing loss at high frequencies resulted from the loss of hair cells in the base of the cochlea and a constant preoccupation with finding a treatment that protects against their toxic effects. A self-protection phenomenon to high ototoxic doses of gentamicin is proposed in this paper. Thirty-eight adult guinea pigs with normal hearing were tested using Preyers reflex and the distortion product otoacoustic emission (DPOAE) test, and their cochleae were analyzed by scanning electron microscopy. To the four groups investigated, group I (control) and group II (low dose, 10 mg/kg/day for 30 days) showed a normal DPOEA and normal outer hair cells; group III (high dose, 160 mg/kg/day for 10 days) showed the absence of DPOEA and damage to the outer hair cells; and group IV (low dose, 10 mg/kg/day for 30 days followed by a high dose of 160 mg/kg/day for 10 days) showed a normal DPOEA and normal outer hair cells. These results demonstrate that there was a considerable self-protection phenomenon by gentamicin.

Ototoxicidade da cisplatina e otoproteção pelo extrato de ginkgo biloba às células ciliadas externas: estudo anatômico e eletrofisiológico

Cisplatina e uma potente droga antineoplasica, largamenteutilizada para o tratamento do câncer, tanto em adultos quantoem criancas. Dentre seus efeitos colaterais, a ototoxicidade seapresenta como um dos mais importantes e leva a perda auditivairreversivel, bilateral, para as altas frequencias (4KHz#8KHz). Es-tudos tem tentado identificar drogas que, associadas a cisplatinapossam atuar como otoprotetores. Sabe-se que o mecanismo daototoxicidade pela cisplatina esta relacionado a alteracoes nosmecanismos antioxidantes das celulas ciliadas, principalmente ascelulas ciliadas externas da coclea.

Otoproteção da amifostina aos efeitos ototóxicos da cisplatina: estudo em cobaias albinas por emissões otoacústicas produtos de distorção e microscopia eletrônica de varredura

Cisplatin is an antineoplastic drug for cancer treatment in children and adults. The side effects of cisplatin ototoxicity are significant: irreversible bilateral hearing damage to high frequencies (4 kHz - 8 kHz). Reports recognize some drugs that are associated with cisplatin to obtain an otoprotector effect. The ototoxicity mechanisms of cisplatin are related to injury of hair cell oxidation mechanism, especially of outer hair cells. AIM: Using otoacoustic emissions distortion products (DPOEA) and scanning electron microscopy we intended to verify the action of amifostine, a radioprotective drug that has well known antioxidant characteristics and otoprotector effects to cisplatin injury. STUDY DESIGN: Experimental. MATERIAL AND METHODS: We used an experimental guinea pig model. The study was performed as follows: group 1: 6 animals, 12 ears, cisplatin 8.0 mg/Kg/day (IP), 3 days. Group 2: 6 animals, 12 ears, amifostine 100 mg/Kg/day (IP) and after 90 minutes, cisplatin 8.0 mg/Kg/day (IP), 3 days and group 3: 3 animals, 6 ears, amifostine 100 mg/Kg/day (IP), 3 days. RESULTS: DPOEA were present before and after treatment in groups 2 and 3. The normal cilium architecture of outer hair cells was supported in all cochlear turns in groups 2 and 3. We concluded that amifostine has a potential otoprotector effect against cisplatin ototoxicity and could be used in clinical trials.

Anatomical and functional evaluation of tympanoplasty using a transitory natural latex biomembrane implant from the rubber tree Hevea brasiliensis

PURPOSE To compare the role of transitory latex and sylastic® implants in tympanoplasty on the closure of tympanic perforations. METHODS A randomized double-blind prospective study was conducted on 107 patients with chronic otitis media submitted to underlay tympanoplasty and divided at random into three groups: control with no transitory implant, latex membrane group, and sylastic® membrane group. RESULTS Greater graft vascularization occurred in the latex membrane group (p<0.05). Good biocompatibility was obtained with the use of the latex and silicone implants, with no effect on the occurrence of infection, otorrhea or otorragy. CONCLUSION The use of a transitory latex implant induced greater graft vascularization, with a biocompatible interaction with the tissue of the human tympanic membrane.

[Amifostine otoprotection to cisplatin ototoxicity: a guinea pig study using otoacoustic emission distortion products (DPOEA) and scanning electron microscopy].

UNLABELLED Cisplatin is an antineoplastic drug for cancer treatment in children and adults. The side effects of cisplatin ototoxicity are significant: irreversible bilateral hearing damage to high frequencies (4 kHz - 8 kHz). Reports recognize some drugs that are associated with cisplatin to obtain an otoprotector effect. The ototoxicity mechanisms of cisplatin are related to injury of hair cell oxidation mechanism, especially of outer hair cells. AIM Using otoacoustic emissions distortion products (DPOEA) and scanning electron microscopy we intended to verify the action of amifostine, a radioprotective drug that has well known antioxidant characteristics and otoprotector effects to cisplatin injury. STUDY DESIGN Experimental. MATERIAL AND METHODS We used an experimental guinea pig model. The study was performed as follows: group 1: 6 animals, 12 ears, cisplatin 8.0 mg/Kg/day (IP), 3 days. Group 2: 6 animals, 12 ears, amifostine 100 mg/Kg/day (IP) and after 90 minutes, cisplatin 8.0 mg/Kg/day (IP), 3 days and group 3: 3 animals, 6 ears, amifostine 100 mg/Kg/day (IP), 3 days. RESULTS DPOEA were present before and after treatment in groups 2 and 3. The normal cilium architecture of outer hair cells was supported in all cochlear turns in groups 2 and 3. We concluded that amifostine has a potential otoprotector effect against cisplatin ototoxicity and could be used in clinical trials.

The topical use of insulin accelerates the healing of traumatic Tympanic membrane perforations

In recent years, there has been a tendency to search for regulatory substances that can optimize the healing process of perforated tympanic membranes (TMs). The purpose of this study was to determine the effects of using topical insulin on the healing process of traumatic TMs perforations.

Spontaneous healing of the tympanic membrane after traumatic perforation in rats

UNLABELLED The most common etiologies of tympanic membrane perforation are infections and trauma. OBJECTIVE The objective of the present study was to assess the healing of traumatic tympanic membrane perforation in rats. METHODS The tympanic membrane from male Wistar rats was perforated in the anterior and posterior portions to the handle of the malleus. Five tympanic membranes were evaluated 3 days after tympanic perforation; 5 after 5 days; 5 after 7 days; 3 after 10 days; and 4 after 14 days. The tympanic membranes were submitted to histopathological evaluation after hematoxylin-eosin staining. RESULTS Tympanic membrane closure occurred at about 7-10 days after injury and the healing process was complete by day 14. The proliferative activity of the outer epithelial layer was present close to the handle of the malleus and to the tympanic annulus. CONCLUSION The spontaneous healing process of the tympanic membrane starts from the outer epithelial layer, with later healing of the lamina propria and the mucosal layer.