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Biomedical subjects

P Dessi

Publications and source records attributed to P Dessi.

At least 19 recordsLinked to original sources

[Microinvasive endonasal surgery: contribution of endoscopy to maxillofacial surgery].

Video-assisted endonasal endoscopic surgery is used for a constantly increasing number of indications, replacing more invasive external approaches. Indications include chronic bacterial and fungal sinusitis, nasosinus polyposis, mucocele, inverted papilloma, and lacrimal duct stenosis. This microinvasive technique offers the advantage of preserving the physiological properties of the mucosa while assuring proper ventilation of the nasal and sinus cavities. We discuss the technical basis of this new surgical option used by ear-nose-throat specialists and maxillofacial surgeons. We focus on turbinai, septal, maxillary, and lacrimal surgery but do not discuss the more specific rhinology areas such as ethmoidectomy, sphenoidotomy or frontal surgery. The main procedures are described together with indications and expected results.

Dacryocystorhinostomy↗

Cavernous sinus thrombosis secondary to non-invasive sphenoid aspergillosis.

The sphenoid localization of aspergillosis is a rare sinusal disease, often latent or asymptomatic. The neurological complications are the result of invasive forms occurring in most cases for the immunocompromised or diabetic patients. Nevertheless, non-invasive sphenoid aspergillosis may cause also several complications and affect the vital prognosis of nonimmunocompromised patients. This report is about two cases of cavernous sinus thrombosis secondary to a non-invasive sphenoid aspergillosis. The authors refer to the clinical and radiological findings and therapeutic approach of this rare complication.

Aged↗

[A case of nasal septum schwannoma: endoscopic resection].

OBJECTIVES: To define clinical and radiological characteristics of nasal septal schwannoma, and to propose endoscopic surgery. PATIENT AND METHODS: We report a case of an isolated schwannoma of the anterior part of the nasal septum, without involvement of any local structure. The only preoperative symptom was nasal obstruction. Imaging study included a CT scan and an MRI study. RESULTS: Schwannoma is a sheath tumor originating from Schwann cells of peripheral nerves. It rarely occurs in nasal and paranasal sinuses and its development on the nasal septum is extremely rare. Complete removal of the tumor was performed by endoscopic sinus surgery technique. Limits of the excision were free of tumor and the histological type was Antoni type A Schwannoma. After a year of follow up, the patient is free of recurrence. CONCLUSION: The Schwannoma of the nasal septum is a rare tumour whose clinical and radiological diagnosis by CT scan and IRM is relatively easy. Its treatment is surgical and the endoscopic surgery can be proposed in the forms slightly extensive.

Endoscopy↗

[Antrochoanal polyps: diagnosis and management].

Antrochonal polyp is a unilateral and benign tumor of the maxillary sinus occurring in children. Its physiopathology remains unclear. Nasal presenting symptoms are unilateral obstruction and nasal discharge. In rare cases, presenting symptoms may be atypical. Radiographic examination with CT-scan and more rarely MRI helps the diagnosis. Surgery remains the mainstay of treatment and the endoscopic approach should be used in first intention. Double maxillary meatotomy by endoscopic approach procures a good exposure and permits a complete resection of the pedicle of the polyp. The insertion of the pedicule should be coagulated. In cases with recurrence or in cases of incomplete resection, an external approach (Caldwell-Luc) should be preferred.

Diagnosis, Differential↗

[Sphenoid sinusitis].

Sphenoid sinusitis is uncommon, with an incidence of about 2.7%. Failure to diagnose and treat sphenoid sinus disease has been shown to lead to serious neurologic sequellae. Plain radiographs play a limited role in the management of sinusitis. CT scan can provide a positive diagnosis by the visualization of mucosal thickening, air-fluid level and complete opacification of the sinusal cavities. In addition, CT can provide more information about the anatomy and abnormalities of the sphenoid sinus. MRI is used in cases of suspected tumors or neurologic involvement. The most common presenting symptom is headache that arise characteristically, but rarely, from the vertex. Sphenoiditis has a high risk of severe neurologic involvement, cavernous sinus thrombosis being one of the most serious complications.

Cavernous Sinus Thrombosis↗

[Multifactorial analysis of preoperative functional symptoms in nasal polyposis (report of 403 patients)].

PURPOSE: Nasal polyposis is an invading disease whose evolution is dominated by functional symptoms. The aim of this study was to evaluate in cortico-resistant patients with nasal polyps the pre-operative functional symptoms in order to define factors that might increase them. METHODS: 403 patients were included in this study. All of them met the inclusion criteria of follow-up and initial examination. Anosmia, pain, nasal obstruction, rhinorrhea and sneezing were evaluated by patients themselves. Radiological data, respiratory function test results and histological data were matched. RESULTS: In our series, functional symptoms were dominated by anosmia, nasal obstruction and rhinorrhea. Pain and sneezing appeared to be less frequent. Analysis of co-variables allowed us to define factors which increased pre-operative functional symptoms. Some of them are well known (such as Fernand-Widal triad or stage 3 nasal polyposis), while others appear new or surprising. The same is true for frontal sinus involvement on CT-scan and glandular hyperplasia on histological study. CONCLUSION: Analysis of the complete clinical, radiological and histological picture has allowed us to emphasise the importance of certain factors on the functional symptoms of 403 patients with polyps of the nose and sinuses, resistant to steroid treatment. The same is true for Widal's disease, for a higher endoscopic grading, for frontal sinus involvement, and for histological evidence of glandular hyperplasia.

Adolescent↗

[Pleomorphic adenoma of the nasal cavity: a case arising from the wall of the maxillary sinus].

INTRODUCTION: Pleomorphic adenoma is a common and benign tumour, originating from sero-mucous glands. Location in the nasal cavity and particularly on the medial wall of the maxillary sinus is very rare. PATIENTS AND METHODS: One patient with a pleomorphic adenoma of the nasal cavity and a review of literature are reported in order to describe the diagnostic and therapeutic management of this tumour. RESULTS: A 63-year-old woman was referred to our institution for evaluation of an unilateral nasal tumour. Clinical and radiological studies revealed an intra-nasal tumour, slightly lytic in nature, arising from the mucosa of the medial wall of the maxillary sinus. More than 2 years after complete excision of the tumour using an endoscopic procedure, the nasal cavity was free of tumour. DISCUSSION: Pleomorphic adenoma of the nasal cavity is a rare and benign tumour, usually presenting as a unilateral nasal tumour. Prognosis of this tumour is mainly linked to recurrences in cases of incomplete resection and to possible metastasis, such as an eventual malignant evolution. The gold standard treatment is complete surgical resection. After a complete imaging study for patient selection (CT scan and MRI), endonasal endoscopic surgery seems to be a reliable therapeutic treatment. CONCLUSION: Intra-nasal pleomorphic adenoma originates from nasal seromucous glands. Radiological study reveals a slightly lytic tumour developed from the septum of the medial wall of the maxillary sinus. Resecton can be performed with endoscopic endonasal surgery as long as the orbital bony framework and the ethmoidal roof are free of tumour. Whatever technique is employed, long term follow-up has to be used to detect any recurrence.

Adenoma, Pleomorphic↗

Protein import into plant mitochondria: precursor proteins differ in ATP and membrane potential requirements.

The import pathways of the alternative oxidase and the F(A)d subunit of the ATP synthase from soybean were characterised. The F(A)d precursor does not require extramitochondrial ATP for import and this was shown to be a characteristic of the mature protein. The alternative oxidase and F(A)d precursors were shown to differ in their requirement for a membrane potential. The membrane potential was modified using malonate, a competitive inhibitor to complex II. The alternative oxidase could be imported at higher malonate concentrations compared to the F(A)d. This difference could not be ascribed to the number of positive charges in each presequence as would be predicted from similar studies in fungi.

Adenosine Triphosphate↗

[Epistaxis].

Epistaxis is a frequent clinical sign, but it can bring vital prognosis. Therefore a local or general cause must be searched without delay for stopping bleeding. We propose to pass in review etiologies, actual treatments and management of epistaxis.

Adult↗

Radiological follow-up of inverted papilloma.

The aim of this study was to describe cross-sectional imaging features of recurrent papilloma of the nasal fossa and paranasal sinuses and to evaluate the role of MR and CT in the postoperative follow-up of this lesion. Magnetic resonance imaging and CT of ten patients who presented recurrence of inverted papilloma were reviewed and correlated to initial imaging, endoscopy, and surgical reports. Imaging patterns of recurrent inverted papilloma are identical to those of initial tumors and recurrence location is closely related to the site of the former lesion. Magnetic resonance is more efficient than CT for the diagnosis and evaluation of extensions. Magnetic resonance supplies the deficiencies of endoscopy in case of extensions to the frontal sinus or the lateral recess of the antrum, especially if mucosal hyperplasia or sinusitis is associated. Magnetic resonance imaging is the first imaging modality to perform in the follow-up after removal of inverted papilloma.

Adult↗

Studies on the topology of the protein import channel in relation to the plant mitochondrial processing peptidase integrated into the cytochrome bc1 complex.

The mitochondrial processing peptidase (MPP) specifically cleaves N-terminal targeting signals from hundreds of nuclear-encoded, matrix-targeted precursor proteins. In contrast to yeast and mammals, the plant MPP is an integral component of the respiratory cytochrome bc1 complex. The topology of the protein import channel in relation to MPP/bc1 in plants was studied using chimeric precursors containing truncated cytochrome b2 (cyt b2) proteins of 55-167 residues in length, fused to dihydrofolate reductase (DHFR). The DHFR domain could be tightly folded by methotrexate (MTX), generating translocation intermediates trapped in the import channel with only the cyt b2 pre-sequence/mature domain protruding into the matrix. Spinach and soybean mitochondria imported and processed unfolded precursors. MTX-folded intermediates were not processed in spinach but the longest (1-167) MTX-folded cyt b2-DHFR construct was processed in soybean, while yeast mitochondria successfully processed even shorter MTX-folded constructs. The MTX-folded precursors were cleaved with high efficiency by purified spinach MPP/bc1 complex. We interpret these results as indicating that the protein import channel is located distantly from the MPP/bc1 complex in plants, and that there is no link between protein translocation and protein processing.

Biological Transport↗

[Essential parathyroid cysts: a misleading lesion].

Though a rare lesion, non-functioning parathyroid cyst is of clinical significance because it usually mimics a thyroid nodule. The cyst can be ectopic in location and therefore constitutes a differential diagnosis to a bronchial or thymic cyst. Two recent cases of non-functioning parathyroid assay are reported. Needle puncture with estimation of the level of parathyroid hormone in the aspirate allows the diagnosis to be made before surgery.

Adult↗

Integration of the mitochondrial-processing peptidase into the cytochrome bc1 complex in plants.

The plant mitochondrial cytochrome bc1 complex, like nonplant mitochondrial complexes, consists of cytochromes b and c1, the Rieske iron-sulfur protein, two Core proteins, and five low-molecular mass subunits. However, in contrast to nonplant sources, the two Core proteins are identical to subunits of the general mitochondrial processing peptidase (MPP). The MPP is a fascinating enzyme that catalyzes the specific cleavage of the diverse presequence peptides from hundreds of the nuclear-encoded mitochondrial precursor proteins that are synthesized in the cytosol and imported into the mitochondrion. Integration of the MPP into the bc1 complex renders the bc1 complex in plants bifunctional, being involved both in electron transport and in protein processing. Despite the integration of MPP into the bc1 complex, electron transfer as well as translocation of the precursor through the import channel are independent of the protein-processing activity. Recognition of the processing site by MPP occurs via the recognition of higher-order structural elements in combination with charge and cleavage-site properties. Elucidation of the three-dimensional (3-D) structure of the mammalian cytochrome bc1 complex is highly useful for understanding of the mechanism of action of MPP.

Animals↗

[Imaging of the adult sinusitis: indications for using conventional techniques, CT scan and MRI].

CT scanning has become the major investigation for sinusitis which is not acute, but chronic. It is a good diagnostic tool, but also allows follow-up assessment of progress, and preoperative evaluation of particular problems related to abnormalities or anatomical variations. MRI scanning has a lesser place, and is most useful in evaluating certain types of pseudo-tumorous sinus conditions, or excluding local complications (in the anterior cranial fossa or orbit).

Adult↗

[Extramedullary plasmocytoma of the nasal cavity: a case report].

PURPOSE OF STUDY: To establish a diagnosis and therapeutic management in patients with extramedullar plasmocytomas. METHOD: There is no consensus concerning extramedullar plasmocytoma treatment. One patient with a nasal cavity tumor location and a review of literature are reported. RESULTS: Extramedullar plasmocytoma is a rare tumor that occurs most frequently in the upper respiratory tract. The most common location is the nasal cavity. Diagnosis can only be made after histological and immunohistochemical examinations. Localized tumors are treated by radiation therapy, combined or not with surgery. Disseminated diseases are treated by chemotherapy. CONCLUSION: Diagnosis can only be confirmed after the exclusion of a systemic disease (multiple myeloma).

Adult↗

Postoperative follow-up of juvenile nasopharyngeal angiofibromas: assessment by CT scan and MR imaging.

The purpose of this study was to assess the radiological findings after surgical removal of juvenile nasopharyngeal angiofibromas (JNA). The postoperative CT and MRI scans of ten patients were reviewed. The cured group included six patients. The non-controlled group included six patients with eight recurrences. Two patients belonged to both groups as they were also followed and cured after surgery for relapse. Four recurrences were asymptomatic and diagnosed by imaging. The imaging patterns were matched to the patients clinical status and endoscopic findings. In the cured group, non-enhanced residual soft tissue masses were seen in all cases. In the non-controlled group, recurrence was always demonstrated on early postoperative CT or MR as a dramatically enhanced mass. The recurrence was located in the lateral or superior aspect of the nasopharynx (n = 3), deep to the fossa of Rosenmuller (n = 4) or out of the nasopharynx (n = 1). In two cases a remaining enhanced mass disappeared spontaneously on iterated examinations. Because of numerous asymptomatic relapses, a radiological workup is recommended four months after surgery, even in patients with normal endoscopy, to rule out posterolateral or extranasopharyngeal recurrences. Spontaneous evolution of residual masses must be appreciated on iterated imaging examinations.

Adolescent↗