[Acute otitis. Etiology, diagnosis, treatment].
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Acute Disease↗
Biomedical subjects
C Dubreuil
Publications and source records attributed to C Dubreuil.
Short therapy with amoxicillin-clavulanate and corticosteroids in acute sinusitis: results of a multicentre study in adults.
Evolution of bacterial resistance shortens antibiotic treatment in ENT infections. The efficacy and tolerance of amoxicillin-clavulanate (ACA), with and without associated short steroid therapy, was evaluated in acute sinusitis of adults at a dosage of 1.5 g/d for 5 d vs. 10 d. This multicentre, randomized, double-blind, placebo-controlled study included 433 patients, 417 of whom were suitable for intent-to-treat (ITT) analysis. The therapeutic success rate in the ITT population, assessed according to strict clinical and radiological criteria, was respectively, 80% and 85% in the 5-d and 10-d treatment groups. Due to the statistical risks that were evidenced, the 2 durations of treatment could not be considered equivalent. The analysis of medical history shows that some risk factors (recurrence of sinusitis, previous surgical sinus drainage) seem to promote therapeutic failure and that 5-d treatment is inappropriate in these patients. The persistence of therapeutic success on day 30 was not influenced by the initial duration of treatment. The efficacy and good tolerance of ACA in acute sinusitis in adults were confirmed. Further studies will be needed to define the indications of short treatments better, which seem to be indicated in the absence of specific risk factors.
Acute Disease↗
Acuteness of preoperative factors to predict hearing preservation in acoustic neuroma surgery.
OBJECTIVES: To determine in patients with acoustic neuromas the predictive factors of hearing preservation according to clinical, radiological, and electrophysiological parameters and to evaluate, for each of these predictive factors, the percentage of patients with preserved hearing. STUDY DESIGN: The study involved 107 candidates for hearing preservation attempt. Mean age was 49.7 +/- 11.4 years. Quantitative and qualitative parameters were prospectively studied. Quantitative parameters were age, duration of functional complaints, hearing loss assessed by pure tone and speech audiometry, and auditory brainstem responses (ABRs). Qualitative parameters (expressed in percentage of presence) were sex, functional complaints, vestibular deficit revealed by vestibular testings, well-shaped ABRs, wave I, III, or V of ABRs, and transient evoked otoacoustic emissions (TEOAEs). METHODS: Patients were divided into two groups according to whether their hearing was preserved (52.3%) or not preserved (47.7%). First, quantitative and qualitative factors were compared between both groups to identify predictive factors. Second, all patients were considered together and the percentage of hearing preservation was determined according to the presence of each predictive factor. RESULTS: The results confirmed the predictive value of classic parameters such as preoperative hearing level, radiological data, and trace of ABRs. They also emphasized the predictive role of other parameters such as short duration of hearing loss, presence of wave III in ABRs, and presence of TEOAEs. CONCLUSIONS: The size of the tumor and the preoperative hearing levels are longstanding predictive factors of hearing preservation in acoustic neuroma surgery, and candidates for hearing preservation are therefore now selected according to these factors. This study added more recent predictive factors and, among the 10 factors identified as predictive, the most relevant to hearing preservation were the presence of TEOAEs (69.7%), short duration of hearing loss (66.7%), and presence of wave III in ABRs (66.7%).
Acute Disease↗
A three-dimensional model of the mouse at embryonic day 9.
This paper describes a digital, three-dimensional model of the mouse embryo at E9. The model was made by reconstruction from images of serial histological sections digitally warped to remove distortions and has a resolution of approximately 9 microns. The model can be digitally resectioned in any plane to provide images which resemble conventional histological sections. The main tissues have been identified and delineated by digital painting so that the anatomical components can be visualized and manipulated in 3-D surface- and volume-rendered views. This provides a three-dimensional definition of anatomy that will provide a useful tool for interpreting and understanding spatial data in mouse embryos. The anatomy of the model is discussed where it provides landmarks for interpretation and navigation or where it is unexpected in light of existing descriptions of the E9 mouse embryo. The complete anatomy is not presented in this paper but will be available on CD-ROM. A detailed description of the technical aspects of the construction of the model is included in an appendix. The model is the first of a series that will form the basis for an atlas/database of mouse development. This reconstruction and its associated anatomy are available in a variety of data formats with some supporting software from http:@genex.hgu.mrc.ac.uk/.
Anatomy, Cross-Sectional↗
Vestibular evoked myogenic potentials in humans: a review.
The human vestibule has preserved an ancestral sound sensitivity and it has been suggested that a reflex could originate from this property, thus inducing cervical muscle microcontractions secondary to strong acoustic stimulations. This reflex is assumed to originate in the saccule, the afferent pathways being either the vestibulocochlear nerve or the inferior vestibular nerve, and the efferent pathways the vestibulospinal tract. Averaging these muscular responses allows vestibular evoked myogenic potentials (VEMPs) to be obtained. The responses consist of two alternatively positive and negative successive waves (p13-n23, p33-n43). The characteristics of this reflex are defined in the literature as follows: it has been established that VEMP amplitude depends on muscular tension. All studies give concording evidence that in healthy subjects the first component of VEMP is more consistent than the second. Binaural stimulation is always responsible for responses of greater amplitude than those obtained from monaural stimulation. Following monaural stimulation, however, VEMPs are either of greater amplitude on the muscle ipsilateral to the stimulation or of the same amplitude on both muscles. There is consensus in the literature demonstrating that VEMP amplitude depends on stimulus intensity: the threshold of VEMP occurrence is clearly above auditory level but varies from one individual to the next. In the 1970s, recordings performed in cases of specific audiovestibular defects suggested that the reflex receptor could be the saccule. More recent studies suggest that the cochlea too could be involved in the response. Likewise, while a number of studies tend to demonstrate that VEMPs depend on vestibular integrity, others suggest that afferent pathways could be of both cohlear and vestibular origin. Finally, while it has been suggested that VEMP efferent pathways travel through the vestibulospinal tract, whether it is the lateral or the medial vestibulospinal tract that is concerned remains to be clarified. A few points regarding VEMP receptors and afferent and efferent pathways call for further investigation. They are inaccurate for use in routine vestibular examination. Once precise receptor localization and pathways are clarified, VEMP recording will provide both a straightforward non-invasive exploration of each vestibule independently and an attractive method by which to explore otolithic receptors and vestibulospinal pathways.
Acoustic Stimulation↗
[Acoustic neuroma in children. Report of 5 cases].
In this report, we present five cases of acoustic neuroma in children; one of them concern a case of neurofibromatosis 2. The most common symptom is a deafness, but it can also be revealed by a tinnitus, a vertigo, a facial nerve paralysis or headache. Diagnosis is confirmed by T1 and T2-weighted MRI with intravenous infusion of gadolinium. The deals of the treatment are tumor's control and preservation of the hearing and facial nerve functions. The means used are either microsurgery with a preference for posteriors approaches to translabyrinthic one, or radiosurgery with gamma knife which seems to be a promising technique for stades II and III tumors. Only children with small acoustic neuroma and good hearing can be simply watched. In neurofibromatosis 2, acoustic neuromas are bilateral and can be associated with other neuromas and cutaneous or ophtalmologic symptoms. Surgery is indicated in first on the side of the biggest tumor or the worst hearing function. Only a few patients well selected may benefit from an auditory brainstem implant.
Adolescent↗
Biologically active Fas antigen and its cognate ligand are expressed on plasma membrane-derived extracellular vesicles.
Exfoliation of plasma membrane components is a directed process that consumes energy and requires active cell metabolism. Proteins involved in regulating the survival and proliferation of eukaryotic cells are released on exfoliated vesicles. We examine here whether the Fas receptor and its cognate ligand (FasL) are present on vesicles shed from high metastatic potential CX-1 cells and low metastatic potential MIP-101 cells and from HuT 78 cells, respectively. Rates of exfoliation at 2 hours and cumulative levels of extracellular vesicles in serum-free medium conditioned by CX-1 cells are increased by 1.8-fold and 1.6-fold, respectively, relative to that in medium conditioned by MIP-101 cells. Although vesicles shed from both cancer cell lines contain Fas antigen, the amount of Fas per vesicle and the percentage of vesicles containing Fas are increased for vesicles isolated from MIP-101 cells, relative to those from CX-1 cells, as determined by immunogold particle labeling and electron microscopy and by immunofluorescence microscopy and flow cytometry. Results of metabolic labeling with 35S-methionine indicate that Fas biosynthesis is reduced by up to 3.3-fold for CX-1 cells, relative to that of MIP-101 cells, consistent with the finding of decreased Fas on vesicles shed from the plasma membrane of CX-1 cells. Although mRNA for soluble Fas receptor is detectable in both cell lines, depletion of shed vesicles from serum-free medium by ultracentrifugation removes all detectable biological activity. FasL is detected on vesicles exfoliated from HuT 78 cells by immunoelectron microscopy and Western blot analysis. FasL-bearing vesicles induce apoptosis of Fas-expressing cancer cells at the same level as observed by treatment with monoclonal anti-Fas antibody. Furthermore, Fas-bearing extracellular vesicles from MIP-101 but not from CX-1 cells protect the CX-1 cell line from FasL-induced and anti-Fas-mediated apoptosis, indicating that Fas present on shed vesicles is biologically active. We conclude that the Fas antigen and its cognate ligand are exfoliated from the cell surface in a bioactive configuration. Exfoliation may provide a mechanism for long-range signal-directed apoptosis while maintaining Fas/FasL on a membrane surface.
Adenocarcinoma↗
Effect of anesthesia on transient evoked otoacoustic emissions in humans: a comparison between propofol and isoflurane.
The influence of general anesthesia (GA) on auditory brainstem responses (ABRs) has been widely studied in humans whereas few studies have been devoted as yet to its effect on cochlear micromechanical properties. This study was aimed at evaluating: (1) the effect of GA on transient evoked otoacoustic emissions (TEOAEs) in humans (n=10), and (2) to compare the effects induced by two different anesthetic agents: propofol (n=5) and isoflurane (n=5). The TEOAEs were continuously monitored together with hemodynamic patterns describing various measures of blood pressure. (1) The GA induced a decrease in TEOAE amplitude and TEOAE amplitude was significantly correlated with the hemodynamic patterns. (2) Both anesthetic agents were responsible for a decrease in TEOAE during the first 20 min of recording. Under propofol, TEOAE amplitude increased after 20 min whereas under isoflurane TEOAEs continued to decrease. Under propofol, TEOAE amplitude was correlated with blood pressure changes in a highly significant manner, whereas under isoflurane TEOAE levels were completely independent of such hemodynamic patterns. These results infer that (1) the GA induced a decrease in TEOAE amplitude, and that (2) TEOAE changes induced by propofol could depend on the concomitant hemodynamic changes whereas isoflurane could be responsible for TEOAE changes depending on both, hemodynamic changes and its own pharmacological properties.
Adult↗
An internet-accessible database of mouse developmental anatomy based on a systematic nomenclature.
This paper reports an internet-accessible database of mouse developmental anatomy (DMDA) that currently holds a hierarchy of the names and synonyms of the tissues in the first 22 Theiler stages of development (E1-E13.5), together with other appropriate information. The purposes of the database are to provide, first, a nomenclature for analyzing normal and mutant mouse anatomy, and second a language for inputting, storing and querying gene-expression and other spatially organized data. DMDA currently contains some 6900 named and staged tissues (e.g. 360 and 1161 tissues in Theiler stage (TS) 14 (E9) and TS22 (E13.5) embryos). DMDA will be extended to include further lineage and other data when it becomes available. The database can be interactively accessed over the internet using either a Java or a non-Java WWW browser at http://genex.hgu.mrc.ac.uk/.
Animals↗
Cochleovestibular afferent pathways of trapezius muscle responses to clicks in human.
Brief intense clicks cause short-latency cervical muscles microcontractions which are supposed to be of vestibular origin. Averaging these microcontractions allows myogenic vestibular evoked potentials (MVEP) to be obtained. MVEP from the trapezius muscles were investigated in normal subjects, cochleovestibular nerve-damaged patients and patients with a vestibular or a cochlear lesion. Muscular responses were recorded on right and left trapezius by averaging from surface electrodes following right and left monaural 100 dB hearing level click stimulation. In normal subjects, responses to monaural stimuli were bilateral, of equal amplitude and latency in left and right trapezia. Normal response consisted of four consecutive waves, labelled p13, n23, p32 and n40 according to their polarity (p, positive; n, negative) and mean peak latency in msec. In total unilateral cochleovestibular damaged patients, auditory stimulation of the affected side gave no MVEP either ipsilateral or contralateral to the stimulation. In the case of selective cochlear lesion, stimulation of the affected side gave MVEP which was present on ipsilateral and contralateral trapezius muscles. The four successive waves were present with a normal latency; however, amplitude was lower than that obtained after stimulation of the healthy ear. In the case of selective vestibular lesion, the four waves of MVEP were again present with normal latency but with reduced amplitude. Responses were present on both the ipsilateral and contralateral trapezius muscle. It is concluded that normal MVEP recorded on the trapezius muscles are bilateral and consist of four waves, the amplitude of which could depend on the simultaneous stimulation of both cochlear and vestibular afferents. In the case of unilateral cochlear and/or vestibular impairments responses were present on both ipsilateral and contralateral trapezius muscles. Latencies had normal values but amplitudes were reduced. MEVP recorded on trapezius muscles were absent in the case of total cochleovestibular damage.
Acoustic Stimulation↗
Effects of cefixime or co-amoxiclav treatment on nasopharyngeal carriage of Streptococcus pneumoniae and Haemophilus influenzae in children with acute otitis media.
A multicentre, open-label, randomized study was performed in 501 out-patients with acute otitis media, aged 6-36 months, to study the impact of treatment with either cefixime suspension 8 mg/kg/day bd or co-amoxiclav suspension 80 mg/kg/day tds for 10 days on nasopharyngeal carriage of Streptococcus pneumoniae and Haemophilus influenzae. Of 426 patients with nasopharyngeal cultures at entry to the trial, end of treatment and at follow-up visit (35 days after inclusion), significant changes in carriage of S. pneumoniae were observed. The proportion of penicillin-resistant S. pneumoniae was higher in the samples taken at the end of treatment and follow-up than in those taken at inclusion, while the total number of children with this microorganism was lower. The difference at the end of treatment was greater with co-amoxiclav than with cefixime. For H. influenzae the resistance rate remained steady while the number of children with this microorganism decreased. At follow-up there was no significant difference between the two groups in terms of nasopharyngeal positive culture for S. pneumoniae or H. influenzae. Despite these differences, successful clinical responses were similar at the end of treatment and at follow-up.
Amoxicillin-Potassium Clavulanate Combination↗
Autoregulation of human inner ear blood flow during middle ear surgery with propofol or isoflurane anesthesia during controlled hypotension.
UNLABELLED: We used controlled hypotension to obtain a bloodless cavity during middle ear surgery under an optical microscope. No previous study has assessed the effect of controlled hypotension on inner ear blood flow (IEF) autoregulation in humans receiving propofol or isoflurane anesthesia. In the present study, the IEF autoregulation was determined using laser Doppler flowmetry in combination with transient evoked otoacoustic emissions (TEOAEs) during controlled hypotension with sodium nitroprusside in 20 patients randomly anesthetized with propofol or isoflurane. A coefficient of IEF autoregulation (Ga) was determined during controlled hypotension, with a Ga value ranging between 0 (no autoregulation) and 1 (perfect autoregulation). During controlled hypotension with propofol, IEF remained stable (1%+/-6%; P > 0.05) but decreased by 25%+/-8% with isoflurane (P < 0.05). The Ga was higher during propofol anesthesia (0.62+/-0.03) than during isoflurane anesthesia (0.22+/-0.03; P < 0.0001). Under propofol anesthesia, there were individual relationships between TEOAE amplitude and change in IEF in four patients. Such a correlation was not observed under isoflurane anesthesia. These results suggest that human IEF is autoregulated in response to decreased systemic pressure. Furthermore, isoflurane has a greater propensity to decrease cochlear autoregulation and function than propofol. IMPLICATIONS: The present study shows that inner ear blood flow is autoregulated under propofol, but not isoflurane, anesthesia during controlled hypotension in humans during middle ear surgery. Further studies are needed to explore the postoperative auditory functional consequences of the choice of the anesthetic drug used in middle ear surgery.
Adult↗
Is the presence of transient evoked otoacoustic emmissions in ears with acoustic neuroma significant?
One hundred sixty-eight patients admitted for acoustic neuroma removal were involved in this study. In all cases, the size of the tumor and the presence or absence of tinnitus and vertigo or dizziness were evaluated. Investigated functional procedures included bilateral measures of pure-tone audiometry (PTA), auditory brainstem response (ABR), electronystagmography (ENG), and transient evoked otoacoustic emissions (TEOAEs). Thirty-five patients (21%) had normal preoperative TEOAEs in the affected ear, whereas 133 patients (79%) failed to show reproducible responses. The aims of this study were 1. to evaluate what distinguishes patients with preoperative TEOAEs in the pathological ear (group A) from those who had no TEOAE (group B); and 2. to determine in cases of attempted hearing preservation whether preoperative TEOAE presence in the neuroma ear (group C) was predictive of postoperative hearing preservation compared with the group of patients without TEOAEs (group D). The presence of vertigo or dizziness was significantly less frequent, the age was lower, and preoperative mean PTA loss in both ears was lower in group A compared with group B. Frequency of the other studied parameters and ABR threshold were similar in both groups. When hearing preservation was attempted, the mean preoperative PTA loss of group C patients was lower in both ears compared with group D. However, postoperative mean PTA loss did not significantly differ in the two groups. In group C, the percentage of hearing preservation (66.6%) was significantly higher than the percentage of deafness (33.4%), whereas in group D the percentage of postoperative preserved audition and deafness did not significantly differ (respectively 44.4% and 55.6%). The findings suggest that 1. TEOAEs in ears with acoustic neuromas are found in younger patients with a lower preoperative mean PTA loss and are accompanied by fewer functional complaints, perhaps because preserved TEOAEs indicate a better preservation of inner ear vasculature; and, 2. along with radiological and electrophysiological investigations, TEOAE presence in the pathological ear could provide an additional criterion or predictive factor for the successful outcome of attempted hearing-conservation surgery in ears with acoustic neuromas.
Age Factors↗
Perilymphatic fistula following airbag trauma.
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Accidents, Traffic↗
Contralateral transient evoked otoacoustic emissions following acoustic neuroma surgery.
This study aimed to evaluate the effect of acoustic neuroma surgery on the contralateral cochlear function using transient evoked otoacoustic emissions (TEOAEs) and to test whether changes in TEOAEs differ according to the type of surgical approach. Forty four patients were included in this study. TEOAEs were recorded in both ears one day before (D0) and one month after surgery (D30). At D30, 20.5% of the patients showed an increase, 22.7% showed a decrease in contralateral TEOAEs amplitude and 56.8% remained stable. In the ear ipsilateral to the neuroma, TEOAE amplitude was significantly lower at D0 in the "increased" group compared to the "decreased" one. In the contralateral ear, TEOAE amplitude was significantly lower at D0 and D30 in the "increased" group compared to the "decreased" one and at D0 compared to the "stable" one. According to the surgical approach the patients were divided into two groups: a Translabyrinthine (TL) group (56.8% patients), and a retrosigmoid (RS) group (43.2% patients). The percentage of patients who presented an "increase" in TEOAEs amplitude in the contralateral ear was higher in the RS group (31.5) compared to the TL one (12%). The PTA lost at D0 was significantly higher in the TL group compared to the RS group. The TEOAE amplitude was significantly higher at D0 in both ipsi- and contralateral ears in the TL group compared to the RS one. These results suggest that acoustic neuroma removal is responsible for changes in contralateral TEOAEs. It can be hypothesized that changes in the efferent fibers secondary to surgery could partly explain these results.
Acoustic Stimulation↗
The mouse atlas and graphical gene-expression database
The large amounts of gene-expression data on mouse development are now too extensive to be stored in any format other than that of a database. Furthermore, as this data is intrinsically graphical and as, in the early developmental stages at least, its boundaries do not map directly to those of anatomical tissues, the natural way to store it is in graphical format. We are therefore constructing a database able to handle such graphical gene-expression data by mapping it onto 3-D reconstructions of mouse embryos whose tissues have been delineated. This article reviews the progress that has been made in this project and describes its two major components, CD-ROMs of the 3-D reconstructions to be held on the user's computer and a gene-expression database that will be maintained at a host site, the two being linked over the internet by a complex Java-based interface for submitting data and querying the database.Copyright 1997 Academic Press Limited Copyright 1997Academic Press Limited
Journal Article↗
Herpes simplex meningitis after surgical removal of a clivus chordoma.
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Acyclovir↗
Sympathetic nerve regulation of cochlear blood flow during increases in blood pressure in humans.
The purpose of this work was to show that regulation of the blood flow to the cochlea by the sympathetic nervous system occurs in humans at the level of the cochlear microcirculation during increases in blood pressure and that its involvement depends on the pressure level. Eight anaesthetized patients undergoing tympanoplasty for hearing disease took part in a pharmacological protocol of stimulation and inhibition of the autonomic nervous system (ANS) to provide variations in systolic blood pressure (BPS) and cochlear blood flow (CBF). The CBF was measured by laser-Doppler flowmetry. Changes in autonomic nerve activity were brought about by changes in baroreceptor activity (BR) initiated by the injection of an alpha adrenergic agent before and after sympathetic and parasympathetic blockade. The CBF variations (delta CBF) were plotted against BPS increases at each stage of the ANS inhibition. The BR diminished significantly after alpha blockade, after alpha and beta blockade, and after alpha and beta blockade and atropine, by 50% (P < 0.01), 29% (P < 0.05), and 95% (P < 0.001) respectively. The BPS increased significantly (P < 0.01) by 36 (SD 9)%, 47 (SD 1)%, and 67 (SD 16)% respectively. The CBF response to an increase in BPS exhibited two opposing variations in the patients: CBF decreased significantly in one group, and increased significantly in the other group. In both groups, delta CBF decrease and delta CBF increase, respectively, were significant after ANS blockade; even so the decrease and increase, respectively, levelled off at BPS around 160 mmHg before ANS blockade. For BPS below 160 mmHg, correlations between delta CBF and BPS were significant before inhibition and after inhibition of ANS. For BPS below 160 mmHg, BPS and delta CBF were not correlated before inhibition of ANS, and were significantly correlated after inhibition of ANS. For BPS below 160 mmHg, CBF response to the BPS increase was the same before and after ANS blockade, i.e. ANS control did not predominate: even so, for BPS above 160 mmHg, the CBF response to BPS increase was different before and after ANS blockade: CBF varied significantly after ANS blockade as it varied for BPS below 160 mmHg, while it remained constant before ANS blockade that elicited ANS control of CBF. In conclusion, sympathetic nerve regulation via its vasomotor tone at the level of cochlear microcirculation occurred markedly when the blood pressure was above 160 mmHg; the autonomic nervous system would appear to control the cochlear blood flow against large variations in blood flow in response to hypertensive phenomena.
Adult↗