Javier Vicente

An efficient and stereoselective synthesis of enantiopure 1,2,7-trihydroxylated pyrrolizidines

Abstract An efficient approach to the stereoselective synthesis of enantiopure 1,2,7-trihydroxylated pyrrolizidines from the readily available optically pure γ-hydroxy-α,β-unsaturated sulfone 2a is described.

Pseudomonas aeruginosa infection in the hypoventilated middle ear: an experimental model.

Conclusion This is a suitable model for studying different aspects of the pathophysiology of chronic suppurative otitis media. Objective To analyze the methodological features of an animal model of chronic suppurative otitis media induced by intratympanic inoculation of Pseudomonas aeruginosa. Material and methods Otitis media was induced by inoculation of P. aeruginosa through the inferior aspect of the rat bulla and cauterization of the Eustachian tube via a transpalatal approach. Inspection of the tympanic membrane, culturing of middle ear effusion and processing of the temporal bones for light microscopy were performed. Results Abnormal otomicroscopic findings and persistence of infection were correlated with the histopathological changes found in middle ear tissues.

Metastatic renal cell carcinoma to the head and neck area.

Aims and background Metastases of renal cell carcinoma to the head and neck are rare. We report on three cases with tumor spread to this area (nasal cavity, tongue and larynx) and present a review of the literature. Patients The first patient presented with lung and nasal cavity metastases five years after renal tumor resection. In patient 2 the diagnosis of primary renal carcinoma and lung and tongue metastases was concomitant. In case 3 a primary kidney tumor was not suspected until radical resection of a tongue lesion was performed. Results The first two patients received radiation therapy. They had been previously treated with interleukin + interferon and vinblastine + interleukin 2 and achieved a survival of 14 and 16 months, respectively. The third patient has not been given any treatment to date (apart from surgery) and remains asymptomatic four years after diagnosis. Conclusions In patients with cell carcinoma the occurrence of lesions in the head and neck area may suggest metastases. In some cases they may precede the diagnosis of a renal tumor and mimic a primary head and neck tumor; otolaryngologists should be aware of this possibility. An individualized treatment approach is recommended. In the case of solitary metastases a surgical excision should be performed as palliation, if not cure.

Fibro-osseous lesions of the external auditory canal

Objectives: To differentiate a novel type of benign circumscribed bone lesion of the external auditory canal from those described previously, such as exostoses and osteomas. Study Design: Information was obtained from computed tomography (CT) images, surgical findings, and pathologic study. Methods: Five patients (26 to 82 years old) who presented a hard, round, unilateral, skin‐covered mass occluding the external auditory canal to varying degrees were studied. A CT study carried out before resection of the lesions by curettage disclosed the absence of a bony connection to the underlying structures. All the tissue specimens underwent pathologic study. Results: CT and surgical findings demonstrated the absence of a connective pedicle. The pathologic findings showed lesions consisting of an osteoma‐like bone formation with sparse osteoblastic areas; mature lamellar bone was observed in three cases, bone marrow containing adipose tissue and hematopoietic remnants in two, and a dense, collagenous stroma in another. They all showed irregular trabeculae, bordered by osteoid osteoblasts. In no case was there evidence of a relationship to the cartilaginous tissue or to the bony structures of the external auditory canal. Conclusions: The data obtained from the clinical, CT, surgical, and pathologic findings suggest the existence of a lesion unlike those previously known, possibly related to ossifying reactions in other parts of the organism.

Tissular changes induced by Pseudomonas aeruginosa in an otitis media rat model with tubal obstruction

Conclusions. This is a suitable model for the study of different features of middle ear inflammation. This model allows manipulations inside the middle ear while preserving relevant structures such as the tympanic membrane, and provides a useful model for the study of interactions between bacterial infection and eustachian tube dysfunction. Objectives. Analysis of early and late histological features in an experimental model of Pseudomonas aeruginosa middle ear inoculation in the rat designed for the study of middle ear procedures. Materials and methods. Thirty Wistar rats were inoculated with Pseudomonas aeruginosa in the tympanic bulla followed by the cauterization of the eustachian tube. Culturing of middle ear effusion was carried out at 7 days follow-up and at sacrifice. Processing of the temporal bones for light microscopy was performed at 7, 14, 30 and 60 days. Results. Early cultures were positive in most cases, thus proving that middle ear inflammation was due to the presence of inoculated Pseudomona aeruginosa. Mucoperiosteal inflammatory changes similar to those observed in human middle ear infection were seen. Acute inflammatory cell infiltration was seen at 7 and 14 days, gradually decreasing to chronic inflammatory changes with fibroplasia at 60 days. Bone resorption was observed at 7 and 14 days, changing to a bony deposition at 30 and 60 days.

Anti-adhesive properties of polytetrafluoroethylene (Gore-Tex) in middle ear surgery. An experimental study.

Conclusions. Polytetrafluoroethylene (PTFE) may represent a material that prevents adhesions when implanted in the middle ear. This characteristic can be used to improve the design of prostheses. Objective. Prostheses in the middle ear have a relatively high failure rate due to extrusion, deformation and adhesion. Adhesion of prostheses to the walls of the tympanic cavity is the commonest cause of long-term hearing loss. The anti-adhesive properties of PTFE have been previously studied in abdominal and vascular surgery. To the best of our knowledge, this is the first work in which the properties of PTFE have been studied in the context of middle ear pathology. Material and methods. In order to induce otitis media with effusion, 27 Wistar rats underwent a technique based on permanent cauterization of the pharyngeal Eustachian tube. PTFE was subsequently implanted in the middle ear. Rats that underwent cauterization without implantation and cauterization with implantation of hydroxyapatite and Plastipore were included as controls. Results. Histopathological study of the tympanic bullae at 15 and 90 days after implantation demonstrated good biocompatibility of the PTFE implant under the analyzed conditions, with formation of a capsule around the material and no adhesions between the ear tissues and the prosthesis.

Chondrosarcoma of the Temporal Bone and Otosclerosis

Chondrosarcoma constitutes 6% of all primary bone tumors and 11% of malignant primary bone tumors. Nevertheless, in a review of the tumor registry of the University of Michigan covering a period of 50 years, there were only 3 cases involving the temporal bone. A case of a woman with a chondrosarcoma of the temporal bone that was partially resected by means of an infratemporal approach at the skull base is presented. This patient had previously undergone surgical treatment for otosclerosis of the other ear. Several considerations regarding survival factors in this type of tumor are dealt with in terms of the histological features, therapeutic options and anatomic location. The possibility that this lesion may originate from the persistence of the cartilaginous inclusions that some authors consider to be involved in the origin of otosclerosis is discussed.

Inner Ear Malformations: Mondini’s Dysplasia

Advances in imaging techniques are enabling the detection of increasing numbers of inner ear malformations. Mondini’s dysplasia, whether alone or in association with other malformations, is one of those most frequently encountered. We report 4 cases of Mondini’s dysplasia treated by us, discussing recent embryological and genetic findings.

Morphological sequence of Plastipore extrusion in experimental otitis media.

Objectives: Plastipore prostheses are still used by many surgeons, although the functional results are controversial. The aim of this study was the morphological analysis of Plastipore material performance in the middle ear of rats, with special attention to extrusion. Methods: Twenty-four Wistar rats were given implants made of commercially available Plastipore and assigned to 3 groups: Group A, with implantation in a healthy middle ear; group B, with implantation and cauterization of the nasopharyngeal orifice of the eustachian tube (hypoventilation); and group C, with implantation, cauterization of the eustachian tube, and bacterial inoculation with Pseudomonas aeruginosa. Results: The pathological study showed in nearly all cases the disintegration of the biomaterial. Adhesion between the biomaterial and bone could be seen in 1 rat from group C (hypoventilation and infection). In group C, the Plastipore was in contact with the tympanic membrane in 1 case and was extruding in 2 animals. Different phases of extrusion were defined. No extrusion was observed in the other groups. Conclusions: The sequential stages of Plastipore extrusion are demonstrated. Infection seems to be the most important factor in Plastipore extrusion in our model.