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Biomedical subjects

J P Sauvage

Publications and source records attributed to J P Sauvage.

At least 19 recordsLinked to original sources
PubMed2006

[Amphicrine adenoma of the middle ear: three cases reports and a review of the literature].

UNLABELLED: Amphicrine adenoma is an extremely rare tumor of the middle ear. We report three cases obtained over a twenty year period. THE AIM OF THIS STUDY: is to discuss our clinical cases and review the literature. MATERIALS AND METHODS: Three cases of middle ear amphicrine tumour were reviewed. RESULTS: During a 10 year period (1986-2006) three cases of middle ear amphicrine tumour were treated at our unit (2 male, 1 female). The presenting complaint was hearing loss in all 3 cases. Amphicrine adenoma is diagnosed by an immuno-histological examination of pathological specimens. Differential diagnosis can be difficult and one individual was initially treated as an adenocarcinoma by radiotherapy. This patient succumbed to cerebral mycosis two years post-radiotherapy. The other two patients have no evidence of recurrence eight and nine years post treatment. CONCLUSION: Historically, differential diagnosis between amphicrine adenoma and adenocarcinoma of the middle ear has been very difficult. Carcinoid tumour is considered to be a more agressive form of amphicrine adenoma. Tumour progression is through loco regional invasion. Complete excision by surgical management with long term follow up is the treatment of choice.

Adenoma↗
PubMed2005

[Benign paroxysmal positional vertigo of the horizontal and superior semicircular canals].

The incidence of benign paroxysmal positional vertigo (BPPV) of the horizontal and superior semicircular canals is much less than that of BPPV due to affection of the posterior semicircular canal. Their diagnosis is however much more difficult and still prone to controversies. The provocative manoeuvre of the BPPV of the horizontal canal (BPPV-HSC) is the manoeuvre of rotation of the head in dorsal position. A horizontal positional nystagmus is obtained. There are two forms of BPPV-HSC: the geotropic form and the ageotropic form. In the geotropic form, the liberatory manoeuvre is a "barbecue" rotation of 180 with 360 degrees towards the healthy side. In the ageotropic form, there is no universal liberatory manoeuvre. Moreover as some cases of neurological aetiology have been recognized, it is not appropriate to apply ineffective manoeuvres. The BPPV of the superior canal (BPV-SSC) is very rare. The provocative manoeuvre is the Dix and Hallpike's manoeuvre. It causes positional torsional and vertical nystagmus with an opposite direction to that obtained for a BPPV of the contra-lateral posterior canal. The liberatory manoeuvre is a Semont manoeuvre, which is identical to that we would make for a contra-lateral BPPV of the posterior canal.

Caloric Tests↗
PubMed2004

[Adult laryngeal cavernous hemangioma: a case report].

We describe a case of laryngeal venous malformation, discovered by dysphonia. This malformation has a different histology and evolution compared to infant laryngeal hemangioma. The histological exam shows large and multiple vessels lined by regular endothelium. There is no spontaneous regression; this malformation can be stable or increase and induce a laryngeal obstruction. Although inconstant, a bluish colour, seen at endoscopy, suggests the presence of venous malformation. The diagnostic is confirmed by MRI, which shows local extension. We propose regular clinical and radiological supervision for asymptomatic venous malformations. Treatment is recommended only for symptomatic patients usually by laryngeal microsurgery or cervicotomy. Per cutaneous sclerosis is an interesting alternative therapy alone or prior to surgery. Regular follow-up is essential in order to detect frequent recurrences.

Adult↗
PubMed2003

Endoscopic endonasal management of invasive skull base mucocele: report of two cases.

Two cases of massive erosive skull base sphenoid mucocele are reported. Even if intra-sphenoid mucoceles are an ENT pathology, when extensive they become of neurosurgical interest. An endoscopic minimally invasive procedure was performed in both cases with an excellent outcome. Patient 1 presented with several years of retro-orbital bilateral pain and several months of purulent pharyngeal leak. CT scan and MRI imaging showed an extensive erosive intra-sphenoid mass, with peripheral contrast enhancement. Patient 2 was referred because of several months of frontal headache and decreased left visual acuity. A wide intra-sphenoid mass was evident at CT scan and MRI. This mass included an anterior compartment, hyperintense on both T (1)- and T (2)-weighted images, and a posterior part, hypointense on T (1)- and hyperintense on T (2)-weighted images. A pure endoscopic endonasal one nostril pure procedure was performed in both cases. Endoscopic technique has been shown to be an easy and minimally invasive procedure. It should be the treatment of choice in case of invasive skull base mucocele in order to avoid blind damage of vasculo-nervous structures which are not protected by the bone, extensively eroded by the lesion.

Adult↗
PubMed2003

[Cerebro-spinal fluid otorrhea and a spontaneous defect of the tegmen tympani or antri. A report of 3 cases . Rôle of arachnoid granulations].

UNLABELLED: Less than 150 cases of cerebro-spinal fluid leak with spontaneous defect of the roof of the temporal bone have been described in the international literature. THE AIM OF THIS WORK: Is to define this pathology, to describe the clinical features, to suggest a diagnostic strategy, and to clarify the treatment method and the hypotheses on causation. MATERIALS AND METHODS: This is a retrospective study of 3 cases. RESULTS: At the first medical examination, the most common clinical feature is serous otitis media or otorrhea after myringotomy. Rhinorrhea is rarely pointed out by the patients but exists in our 3 observations. The diagnosis of cerebro-spinal fluid leak with spontaneous defect of the roof of the temporal bone needs; cerebro-spinal fluid leakage, absence of an otologic history or cranial trauma and a bony defect on CT scan. CT scan with millimeter slices is able to show the location and the size of the bony defect(s) of the roof of the temporal bone and often shows partial or total opacity of the middle ear cavities. MRI is able to show if this opacity exists in conjunction with meningeal hernia or cerebro-meningeal hernia. Surgical repair consists of placing an autologous graft over the bony defect by the middle fossa approach. The origin of a spontaneous defect of the temporal bone is discussed. We study the hypothesis in which arachnoïd granulations could be responsible for a temporal bone defect.

Aged↗
PubMed2001

Octahedral Fe(II) and Ru(II) complexes based on a new bis 1,10-phenanthroline ligand that imposes a well defined axis.

A bis-chelating ligand (L1), made of two 7-(p-anisyl)-1,10-phenanthroline (phen) subunits connected with a p-(CH(2))(2)C(6)H(4)(CH(2))(2) spacer through their 4 positions, has been prepared, using Skraup syntheses and reaction of the anion of 4-methyl-7-anisyl-1,10-phenanthroline with alpha,alpha'-dibromo-p-xylene. Its Fe(II) complex, [FeL1(dmbp)](PF(6))(2), was prepared in one step by reaction of L1 with [Fe(dmbp)(3)](PF(6))(2) (dmbp = 4,4'-dimethyl-2,2'-bipyridine). On the other hand, its Ru(II) complex, [RuL1(dmbp)](PF(6))(2), was prepared in two steps from Ru(CH(3)CN)(4)Cl(2) and L1, followed by reaction with dmbp. X-ray crystal structure analyses show that in the two octahedral complexes, ligand L1 coils around the metal by coordination of the axial and two equatorial positions. It defines a 21 A long axis (O.O distance) running through the central metal and the terminal anisyl substituents. The complexes were also characterized by (1)H NMR, mass spectrometry, cyclic voltammetry, electronic absorption, and, in the case of Ru(II), fluorescence spectroscopy.

2,2'-Dipyridyl↗
PubMed2001

Porphyrinic dyads and triads assembled around iridium(III) bis-terpyridine: photoinduced electron transfer processes.

Multicomponent arrays based on a central iridium(III) bis-terpyridine complex (Ir) used as assembling metal and free-base, zinc(II) or gold(III) tetraaryl-porphyrins (PH(2), PZn, PAu) have been designed to generate intramolecular photoinduced charge separation. The rigid dyads PH(2)-Ir, PZn-Ir, PAu-Ir, and the rigid and linear triads PH(2)-Ir-PAu, PZn-Ir-PAu, as well as the individual components Ir, PH(2), PZn, PAu have been synthesized and characterized by various techniques including electrochemistry. Their photophysical properties either in acetonitrile or in dichloromethane and toluene have been determined by steady-state and time-resolved methods. In acetonitrile, excitation of the triad PH(2)-Ir-PAu leads to a charge separation with an efficiency of 0.5 and a resulting charge-separated (CS) state with a lifetime of 3.5 ns. A low-lying triplet localized on PH(2) and the presence of the heavy Ir(III) ion offer the CS state an alternative deactivation path through the triplet state. The behavior of the triad PZn-Ir-PAu in dichloromethane is rather different from that of PH(2)-Ir-PAu in acetonitrile since the primary electron transfer to yield PZn(+)()-Ir(-)-PAu is not followed by a secondary electron transfer. In this solvent, both unfavorable thermodynamic and electronic parameters contribute to the inefficiency of the second electron-transfer reaction. In contrast, in toluene solutions, the triad PZn-Ir-PAu attains a CS state with a unitary yield and a lifetime of 450 ns. These differences can be understood in terms of ground-state charge-transfer interactions as well as different stabilization of the intermediate and final CS states by solvent.

Electrons↗
PubMed2001

A [2]catenane and a [2]rotaxane as prototypes of topological and Euclidean molecular "rubber gloves".

A [2]catenane and a [2]rotaxane have been prepared from a C2-symmetric, 2,9-diphenyl-1,10-phenanthroline-based (dpp-based) macrocycle incorporating a 1,5-dioxynaphthalene subunit by means of the transition metal templated technique. In the case of the catenane, this macrocycle is interlocked with a dpp-based macrocycle that is oriented through the location of a p-tolyl substituent in the 4-position of the phenanthroline subunit. In the case of the rotaxane, the C2-symmetric macrocycle is threaded onto an oriented, dumbbell-shaped molecule, based on the same 4-p-tolyl-1,10-phenanthroline subunit, which bears tetraarylmethane stoppers. Both species are chemically achiral molecules, yet they are composed entirely of asymmetric, mirror-image conformations. Conformational enantiomerization processes therefore take place exclusively by chiral pathways, conferring on these molecules the "rubber glove" property. However, while the molecular graph (constitutional formula) of the [2]rotaxane can be deformed into a planar and, hence, rigidly achiral representation, a feature shared by a few other compounds in the literature that have been characterized as "Euclidean rubber gloves", the molecular graph of the [2]catenane cannot be deformed in this way. It therefore has the unique property of being a chemically achiral "topological rubber glove".

Journal Article↗
PubMed2001

Shuttles and muscles: linear molecular machines based on transition metals.

Transition-metal-containing rotaxanes can behave as linear motors at the molecular level. The molecules are set into motion either by an electrochemical reaction or using a chemical signal. In a first example, a simple rotaxane is described that consists of a ring threaded by a two-coordination-site axle. The ring contains a bidentate ligand, coordinated to a copper center. The axle incorporates both a bidentate and a terdentate ligand. By oxidizing or reducing the copper center to Cu(II) or Cu(I) respectively, the ring glides from a given position on the axle to another position and vice versa. By generalizing the concept to a rotaxane dimer, whose synthesis involves a quantitative double-threading reaction triggered by copper(I) complexation, a molecular assembly reminiscent of a muscle is constructed. By exchanging the two metal centers of the complex (copper(I)/zinc(II)), a large-amplitude movement is generated, which corresponds to a contraction/stretching process. The copper(I)-containing rotaxane dimer is in a stretched situation (overall length approximately 8 nm), whereas the zinc(II) complexed compound is contracted (length approximately 6.5 nm). The stretching/contraction process is reversible and it is hoped that, in the future, other types of signals can be used (electrochemical or light pulse) to trigger the motion.

Animals↗
PubMed2001

[Lymph node metastasis of cutaneous epidermoid carcinomas of the head and neck: prognostic factors and therapeutic strategies. Apropos of a series of 13 cases].

UNLABELLED: Squamous cell skin carcinoma has a relatively low rate of metastasis (0.5 to 16%), but the prognosis of these metastases is poor (22% of survival at 5 years). PATIENTS AND METHODS: from a series of 243 patients, we studied 13 patients who were found initially to have metastases or who developed metastases later. Fifty-four percent (54%) of the patients presented initially with regional lymph node and parotid involvement in 54%. RESULTS: All patients underwent surgery with removal of the skin cancer and a neck dissection. Radiotherapy was performed later in 92% of the cases. The 2 years survival rate was 62% and mean survival by Kaplan Meier curve was 47 months. DISCUSSION: Poor criteria of these cutaneous tumors are defined: tumor size, histologic differentiation, perineural spread. Patients with severe criteria must have a neck dissection to control the first lymph node. Along the anatomic area of the cutaneous tumor, a parotidectomy, a submaxillary control or a neck dissection will be performed. Its involvement will be followed by a neck dissection. A comparative study of the literature is made. Poor prognostic criteria of these cutaneous tumors are defined, in addition to the initial management of the cervical and parotid lymph nodes.

Aged↗
PubMed2001

[The European Evaluation of Vertigo (EEV) scale: a clinical validation study].

Up until now, the questionnaires used to evaluate vertigo have been self-administered questionnaires that rate either symptoms and/or their consequences. In contrast, the European Evaluation of Vertigo scale (EEV) is a physician-administered questionnaire that only assesses symptoms of the vestibular syndrome: illusion of movement, duration of illusion, motion intolerance, neurovegetative signs, and instability. Twenty-six ear, nose, and throat (ENT) specialists participated in this validation study conducted among 123 patients suffering from different types of vertigo. The reliability, responsiveness and construct, convergent and discriminant validity of the EEV scale were assessed. Construct, convergent and discriminant validity was determined by comparing the scores on the EEV scale with those obtained using the following validated scales: patient diary and conventional scale designed by the DPHM, functional scale of the AAO-HNS, and SF-36 scale, a generic quality of life scale. With the exception of the "neurovegetative signs" item, the reliability of the EEV scale is good, particularly in terms of interrater reliability (r = 0.93 for the global score), and responsiveness is high (p < 0.01). EEV scale has good correlations with the items of patient diary, DPHM scale and "physical" dimensions of SF-36, from the first evaluation, whereas this scale has poor correlation at Day 0, with the items of AAO scale and the "psychological" dimensions of SF-36. These results confirm that EEV scale is exclusively a symptomatic scale and does not interfere with the psychism. The EEV scale is therefore a validated physician-administered questionnaire capable of monitoring the course of vertigo and of assessing the efficacy of anti-vertigo treatments.

Adolescent↗
PubMed2000

[Acute vertigo].

Three questions are raised when a patient experiences sudden vertigo. Is it due to a disease of the vestibule? This would be suggested in case of a revolving nature of the vertigo, the presence of nystagmus and of vestibular ataxia. Are there associated otological (infection of the labyrinth, zoster neuritis) or neurological (ischemic vascular accidents of the cerebral trunk and of the cerebellum, cerebellar haemorrhage) signs? What is the evolution of the sudden vertigo? A single, isolated episode of vertigo will generally be related to vestibular neuritis. However, it may rather be a first episode of repeated vertigo, Ménière's disease, recurrent vertigo, migraine, or very rarely transitory ischemic accident.

Acute Disease↗
PubMed2000

Determination of substituents distribution in carboxymethylpullulans by NMR spectroscopy.

The distribution of carboxymethyl substituents in the alpha-(1 --> 6)-linked maltotriosyl repeating units of a carboxymethylpullulan (CMP) series was investigated by high resolution NMR spectroscopy on very short oligomers (DPn = 1.2-1.5) obtained by acid hydrolysis. A series of 2D NMR experiments on parent pullulan, hydrolysed pullulan and CMP was used to assign the proton and carbon chemical shifts of CMP acid hydrolysates. The degree of substitution (DS) and the relative distribution of -CH2COONa groups at OH-2, OH-3, OH-4 and OH-6 of glucose residues (DSi) were determined from 1H NMR measurements. From a set of CMP samples, widely different in degree of substitution, it was observed that the substitution at C-2 is predominant and decreases according to the order C-2 > C-3 > C-6 > C-4. Taking into account the availability of each OH group in the parent pullulan, an order of relative reactivity of hydroxyl groups is defined according to the relation: Ri = DSi/ni, where ni is the number of free OH groups in a maltotriose unit (MTU) for a given site C-i, the reactivity order was found to be OH-2 > OH-4 > OH-6 > OH-3.

Carbohydrate Sequence↗
PubMed2000

Controlled molecular motions in copper-complexed rotaxanes: an XAS study.

The environment of the central metal of a molecular machine-like copper rotaxane was observed by XAS experiments. The wheel of the rotaxane is a hetero-bischelating macrocycle containing both bidentate (phenanthroline) and terdentate (terpyridine) moieties. The axle of the assembly contains only a bidentate moiety. Applying an external chemical stimulus-oxidation of the metal-increases the number of coordinating atoms required by the metal template from 4 to 5. This variation is consistent with the oscillation of the wheel around the axle, leading thus to the most stable environment for the metal in the Cu(II) rotaxane.

Journal Article↗