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Biomedical subjects

A Trinidad

Publications and source records attributed to A Trinidad.

At least 19 recordsLinked to original sources

Central role of supporting cells in cochlear homeostasis and pathology.

HYPOTHESIS: Supporting cells have a crucial role in degenerative and regenerative events of primary sensorial hair cells of the organ of Corti. This new role should determine future studies about pathophysiology of hearing loss and its regenerative treatment. SUPPORTING EVIDENCE: Recent findings suggest an active role of supporting cells in the maintenance of hair cell function and structure. Evidences of high energy consumption and close proximity to auditory nervous fibers suggesting K+ active exchange, preferential expression of specific proteins and antigens, presence of glucocorticoids receptors, affinity for cisplatin and regenerative potential give the supporting cells an important role in homeostasis of the organ of Corti and in some specific diseases affecting this structure. CONCLUSION: As well as glial cells provide protection and regeneration to neural tissues, supporting cells may provide the necessary metabolic and electrolitic conditions for hair cells mechanical and bioelectrical function. This opens new possibilities for the treatment of apparently "irreversible" destruction of the inner ear.

Animals↗

[External auditory canal cholesteatoma as a complication of ear surgery].

External auditory canal cholesteatomas are a rare disease. Their usual clinical appearance is a mass eroding the bony external auditory canal, normally in the inferior or anterior parts, with an intact tympanic membrane and a normal middle ear. A case of this uncommon disease with a review of the scientific literature is presented. Guidelines for the prevention, diagnosis and management are examined.

Aged↗

Endonasal endoscopic management of a large meningocephalocele in a patient with concomitant middle skull base defect.

The presence of a skull base defect can lead to major complications such as cerebrospinal fluid leak, meningocele, encephalocele and meningitis. It is exceptional to find the existence of two concomitant defects in the skull base. We present the case of a patient with concomitant spontaneous defects of the anterior and middle skull base that were surgically repaired. After 18 years of right rhinorrhea the patient was referred after being diagnosed with a large right nasal fossa meningoencephalocele, which was surgically removed by functional endoscopic sinus surgery. Following the surgery the patient complained about unilateral ear fullness. A paracentesis revealed a highly suspicious cerebrospinal fluid collection. High resolution scans revealed a defect in the mastoid tegmen; subsequently a transmastoid approach was carried out. Greater defects or those lying around the internal auditory canal, are best treated via the middle fossa approach. In the anterior cranial fossa the treatment of choice is provided by endoscopic procedures, but frontal bone craniotomy should be considered if the defect is in the frontal sinus or greater than 5 cm in size.

Cerebrospinal Fluid Rhinorrhea↗

Point mutation of an EYA1-gene splice site in a patient with oto-facio-cervical syndrome.

Mutations of the EYA1 gene (8q13.3) are the most common known cause of the branchio-oto-renal dysplasia (BOR), an autosomal dominant disease that includes developmental defects of branchial arch structures, middle and/or inner ear and kidney. The distinction between BOR and other dysplasias, such as oto-facio-cervical syndrome (OFC), is challenged by frequent association of the former to other diverse malformations, and by variable expressivity even within the same family. OFC is characterized by trophic alterations of the facies and shoulder girdle in addition to the malformations seen in BOR. Recent characterization of one OFC patient shed some light on the controversy over whether OFC and BOR are the same disease, and led to the hypothesis that OFC is caused by contiguous deletions of EYA1 and adjacent genes. By contrast, we show here that an OFC patient bears a single-nucleotide substitution in a splice site of EYA1. Our results indicate that not only major rearrangements, but also point mutations altering the EYA1 reading frame, can be found in patients with OFC syndrome.

Abnormalities, Multiple↗

Escherichia coli O157:H7 outbreak linked to salami, British Columbia, Canada, 1999.

An outbreak of E. coli O157:H7 infections was identified in November 1999 with a fivefold increase in the occurrence of laboratory-confirmed cases of E. coli O157:H7 infection. A matched case-control study was conducted. Samples of food from cases and from retailers were analysed for the presence of E. coli O157:H7. A total of 143 cases were identified over a 12-week period with the same pulsed-field gel electrophoresis (PFGE) pattern. The case-control study found that Company A salami was significantly associated with illness (Mantel-Haenszel matched odds ratio 10.0%, 95% CI 1.4-434, P=0.01). Company A salami tested positive for E. coli O157:H7 and isolates had the same PFGE pattern as case isolates. An immediate voluntary national recall of Company A dry fermented meat products took place. Findings from the investigation of this outbreak suggest that the hold-and-test option may not be adequate to prevent shiga-toxigenic Escherichia coli (STEC) infection in salami consumers.

Adolescent↗

Management of N0 neck in laryngeal carcinoma. Impact on patient's survival.

Management of patients with carcinoma of the larynx should systematically include an appropriate treatment of lymph nodes according to the TNM stage. One of the most controversial points of the treatment in these patients is the management of the clinically negative neck (N(0)). A retrospective study of 295 patients with laryngeal carcinoma and N(0) neck undergoing treatment in our centre between 1983 and 1993 is presented. We observed a significant decrease in the survival of clinically N(0) patients with histologically affected lymph nodes. Lymphadenopathy was more frequently detected in patients with supraglottic tumours (38 per cent) when compared to glottic tumours (16 per cent). In our experience, routine bilateral and unilateral dissection of N(0) necks in all supraglottic tumours and in T3-T4 glottic tumours, respectively, is the most beneficial approach for patients in terms of survival.

Adult↗

[Cochlear cytotoxic activity of cisplatin in experimentation animals. A study using scanning electron microscopy].

Cisplatin is an antitumoral agent commonly used in the treatment of different solid tumors. Its use induces adverse effects like oto- and nephrotoxicity due to acute renal failure. This makes it a suitable drug when creating an experimental model of ototoxicity. Our aim is to study the cellular lesions induced in the cochlea of the rat and the guinea pig by variable doses of cisplatin injected intraperitoneally, after short, middle, and long term survival, by means of scanning electronic microscopy. Results show the global effect of the cells of the organ of Corti with a more intense initial damage of the supporting cells, continuing with the late effect of the sensorial cells.

Animals↗

Ventral approach to the rat middle ear for otologic research.

OBJECTIVE: To describe a simple approach to the rat middle ear because there are few clear descriptions of this technique with minimal morbidity and mortality. STUDY DESIGN AND SETTING: Six male Long-Evans rats were used in this study. We designed a cervical approach to the middle ear with the purpose of creating an experimental model of ossiculoplasty that permits the postoperative survival of the animal. RESULTS: It was possible in all cases to visualize the majority of structures of the tympanic cavity: promontory, round window, stapedial artery, stapes, incus, and tympanic membrane. There were no cases of postoperative infection or facial paralysis. CONCLUSIONS AND SIGNIFICANCE: The ventral approach to the rat middle ear is a rapid and simple technique that makes the rat the animal of choice for many otologic investigations.

Animals↗

[Tubal involvement in nasopharyngeal carcinoma].

Nasopharyngeal carcinomas are frequently diagnosed in advanced stages in patients who present with secretory otitis or neck mass. However, survival after treatment is directly related to early diagnosis. The present study analyzed Eustachian tube involvement in nasopharyngeal carcinoma as a pathogenic mechanism in secretory otitis. The presence of otologic symptoms was correlated with the morphological description of the tumor and clinical manifestations in 198 patients with nasopharyngeal carcicoma.

Carcinoma↗

[Mixed tumor (pleomorphic adenoma) of head and neck. Typical and atypical patterns].

Pleomorphic adenoma is a benign growth frequently encountered in major salivary glands, although minor salivary glands sometimes can be affected. In the latter non-specific clinical signs allows only the postoperative diagnosis. Nevertheless the existence of lesser salivary glands outside the oral cavity, and therefore pleomorphic adenomas, justify the specialist's need of its knowledge because of the difficulties arising in differential diagnosis. The AA. present a review of 22 cases in various sites treated in their Department in a 9 year-term.

Adenoma, Pleomorphic↗

[Cervical teratoma in an adult].

Teratomas are germ-cell tumors that usually originate in the gonads. Extragonadal teratomas are rarely found in the neck, particularly in adults. A case of cervical teratoma that presented as a rapidly growing mass in a young man is described. The diagnostic problems are commented.

Adult↗

[Use of the Internet in otorhinolaryngology].

The Internet is considered by some as one of the most important advances of the late 20th century. The Internet is the functional linking of personal computers via telephone lines to a worldwide network of millions of other computers, which enables them to exchange information freely. Although the Internet crops up in daily conversation, many persons are not aware of its usefulness and relevance for ear, nose and throat specialists. The Internet is accessed by special software that maximizes the potential of this vast computer network. The most important tools are e-mail and the World Wide Web. These tools make it possible to consult multimedia medical publications, access Medline, and carry out information searches, etc. The Internet and its most important uses in otolaryngology are summarized and a list of useful addresses is given. Although its advantages still are not widely appreciated, widespread Internet use is imminent and we think that it is a useful technology to know and use. Moreover, access is becoming easier and cheaper.

Computer Communication Networks↗

[Immune-mediated inner ear disease: report of clinical cases].

Many clinical and experimental studies have obtained evidence of immune-mediated inner ear disease. Discrepancies between theories of the mechanisms of injury to the inner ear and the laboratory tests that identify it mean that the diagnosis is based on clinical symptoms and a positive response to treatment. We report four cases of immune-mediated inner ear disease characterized by endolymphatic hydrops, fluctuating hearing loss, sudden deafness (first symptom of primary Sjögren's syndrome), and rapidly progressive sensorineural hearing loss.

Adult↗