Search PubMed⌕ Search

Biomedical subjects

O Michel

Publications and source records attributed to O Michel.

At least 37 records · Page 2Linked to original sources
PubMed2001

Follow-up of transnasal orbital decompression in severe Graves' ophthalmopathy.

OBJECTIVE: To evaluate the safety and efficacy of transnasal orbital decompression for severe Graves' ophthalmopathy. DESIGN: Retrospective noncomparative case series with extended clinical follow-up. PARTICIPANTS: Seventy-eight consecutive subjects who were operated on for compressive optic neuropathy with loss of visual acuity or visual field defects after failure of medical and radiation therapy. INTERVENTION: Strictly transnasal, endoscopic-controlled bilateral decompression of the medial and inferomedial wall of the orbit. MAIN OUTCOME MEASUREMENTS: Preoperative and postoperative examination, including vision, Hertel exophthalmometry, ocular motility, visual fields, Goldmann perimetry, and notification of complications, intranasal signs of inflammation, and subjects' assessment of the procedure. RESULTS: One hundred forty-five endonasal decompressions were performed on 78 subjects (63 women, 15 men, 52.2 +/- 10.3 years) during a 10-year period. Sixty five patients were bilaterally operated on; 15 required only unilateral decompression. Four of 78 needed repeat surgery. Visual acuity increased from a preoperative average of 0.50 +/- 0.27 (range, 0.01-1.25) to 0.75 +/- 0.21 (range, 0.01-1.25) postoperatively. An average reduction of proptosis of 3.94 +/- 2.73 mm (range, -1.0-11.0 mm) was achieved with a mean preoperative Hertel measurement of 22.19 +/- 3.13 mm (range, 15-34 mm). Ocular motility was corrected by recession of the medial rectus muscle in 58 of 78 cases. Twenty-six of these 58 cases were simultaneously operated on in the same surgical session immediately after the transnasal decompression, and the others after a period of 2 to 3 months. CONCLUSIONS: The transnasal orbital decompression procedure improved vision, decreased proptosis in a range comparable to more invasive techniques, and had favorable cosmetic results without additional disfiguration by scars. Morbidity was far less than with other approaches. Postdecompression strabismus was successfully managed by recession of both medial orbital muscles in the same surgical session.

Adult↗
PubMed2001

Progressive hearing loss in hearing impaired children: immediate results of antiphlogistic--rheologic infusion therapy.

OBJECTIVE: The question whether progressive sensorineural hearing loss during childhood is the fateful course of a main illness has been discussed controversially over 60 years. No medicamentous therapy with satisfactory results has been described in the literature. The goal of this study was to determine whether an infusion therapy, developed for the treatment of sudden hearing loss in the elderly, can induce recovery after progression in sensorineural hearing loss during childhood. METHODS: Out of 20 children suffering from acute progression in sensorineural hearing loss, seven children were treated with an infusion therapy containing prednisolone, pentoxifylline and a plasma expander (group I), and 13 children were not treated (group II). All children were advised not to use hearing aids for 6 weeks. RESULTS: In group I, we observed partial to complete restoration of hearing threshold towards the original hearing threshold given by previous routine controls in 6/7 children. In group II, only three children recovered, with the state of ten children's' hearing loss remaining unchanged. The long-term follow-up, however, showed no distinct difference in either group. CONCLUSION: Infusion therapy can be helpful when treating acutely progressing sensorineural hearing loss during childhood. The benefit for communicative competence has to be discussed. Further studies should be conducted.

Case-Control Studies↗
PubMed2001

Immunohistochemical detection of vascular endothelial growth factor (VEGF) and VEGF receptors Flt-1 and KDR/Flk-1 in the cochlea of guinea pigs.

Vascular endothelial growth factor (VEGF) is known as an endothelial cell-specific mitogen. There are no reports concerning the presence of VEGF in the inner ear. To gain information, immunohistochemical analysis using specific antibodies to VEGF and to both known VEGF receptors Flt-1 and KDR/Flk-1 was performed on paraffin-sectioned temporal bones from five guinea pigs. Immunoreactivity of VEGF, Flt-1 and KDR/Flk-1 was detectable in spiral ganglion cells. VEGF could also be found in the endothelium of blood vessels, in the spiral ligament and in the organ of Corti. Flt-1 was found in the limbus epithelium, in all supporting cells of the organ of Corti, in Claudius cells, cells of the sulcus and in the spiral ligament. Flk-1 could be detected in some supporting cells of the organ of Corti (inner pillar cells and Deiters' cells). Immunoreactivity to Flk-1 was also found in endothelium of blood vessels and in the spiral ligament. Hair cells showed VEGF immunostaining, but did not contain staining to Flt-1 nor Flk-1. In the stria vascularis any immunoreactivity to all used VEGF and VEGF receptor antibodies could not be detected. The findings were supported by Western blot analysis on inner ear tissues and ovaries from guinea pigs. We may conclude that the growth factor VEGF and both receptors participate in cochlear physiology.

Animals↗
PubMed2001

Detection of apoptotic change in the lipopolysaccharide (LPS)-treated cochlea of guinea pigs.

This study was undertaken to examine, electrophysiologically and immunohistochemically, the effect of endotoxin on the guinea pig cochlea. A bacterial endotoxin (lipopolysaccharide, LPS, 5 mg/ml, 0.2 ml) was injected into the middle ear trans-tympanically. The electrocochleograms were continuously recorded from before to 48 h after the injection with an electrode inserted into the facial canal. Then, the animals were sacrificed by intracardiac perfusion of a fixative, temporal bones were removed and immunohistochemically stained for single-stranded DNA (ssDNA) and caspase 3 (CPP32). ssDNA was detected at 48 h in the stria vascularis and spiral ligament. CPP32 was observed in the stria vascularis, the spiral ligament and the organ of Corti. The threshold of the compound action potential increased significantly at 48 h in the LPS group. These results suggest that the activation of CPP32 and fragmentation of DNA are involved in the dysfunction of the cochlea observed under inflammatory conditions.

Action Potentials↗
PubMed2001

[Influence of an internal nasal dilator (Nasanita) on nasal flow in healthy adults].

Influence of an Internal Nasal Dilator (Nasanita) on Nasal Flow in Healthy Adults. In a prospective, randomized study the influence of dilatation of the vestibulum nasi by an internal dilatator type Nasanita on the nasal flow of healthy adult persons was tested. Primary target was the inspiratory nasal flow as measured by rhinomanometry. Secondary targets were subjective evaluation of the nasal breathing and the judgement of the subjects on the comfort of carrying the stent. The insertion of the stent type Nasanita increased the nasal flow from 614 +/- 151 ccm/sec about 54 % to 920 +/- 198 ccm/sec (p = 0,00000016). The expiratory nasal flow increased from 622 +/- 169 ccm/sec about 55 % 928 +/- 230 ccm/sec (p = 0,0000008). Subjectively the insertion of the stent improved the nasal breathing slightly to significantly. The comfort of wearing was classified mostly indifferent to slightly unpleasantly. The internal nasal stent Nasanita has proven to be an agent to increase nasal flow significantly.

Adult↗
PubMed2001

Healthy subjects express differences in clinical responses to inhaled lipopolysaccharide that are related with inflammation and with atopy.

BACKGROUND: Endotoxin and its purified derivative LPS are important contaminants of both domestic and occupational environments that have been related to airway diseases. A body of data suggests that there is considerable interindividual variability in LPS sensitivity. OBJECTIVE: The aim of the study was to relate the individual clinical responses to inhaled LPS with the inflammatory process and the atopic status. METHODS: Fifteen healthy subjects were challenged each week by inhalation with saline solution or LPS (0.5, 5, or 50 microg). The systemic response was defined by the increase in body temperature, blood neutrophilia, acute-phase proteins (C-reactive protein and LPS-binding protein [LBP]), and E-selectin. The LPS-induced airway response was defined as the increase in airway responsiveness and related to the cell count and concentration of TNF-alpha, myeloperoxidase, and eosinophil cationic protein in induced sputum. The atopic status was defined as an increase in IgE or a positive skin prick test result. RESULTS: Subjects (n = 7) with a significant increase in body temperature had a larger increase in the systemic inflammatory response (blood neutrophilia; P <.01) and in blood concentrations of C-reactive protein (P <.02) and LBP (P <.01). Subjects with a significant increase in airway responsiveness (n = 8) had an increase in the sputum concentration of eosinophil cationic protein (P <.01). The amplitude of the systemic response (increase in body temperature [P <.001], blood neutrophilia [P <.02], and rise in LBP [P <.05] and decrease in FEV(1) [P <.01]) were inversely associated with the atopic status, suggesting a link between atopy and LPS responsiveness. CONCLUSIONS: The clinical response to LPS occurs systemically or locally and is associated with inflammation. The atopic status was inversely related to the systemic inflammation.

Acute-Phase Proteins↗
PubMed2001

Continuous intratympanic infusion of gentamicin via a microcatheter in Menière's disease.

Between 1995 and 1998, 11 patients with disabling Menière's disease were treated at our institution with a continuous gentamicin infusion into the middle ear via a microcatheter. The patients had frequent attacks of vertigo and vomiting (functional levels 3-5). Hearing threshold on the affected side was significantly worse than on the healthy side (stage 4+5). Gentamicin was applied by a high-precision insulin pump with a flow rate of 40 mg per day directly in front of the round window. Application was stopped as soon as signs of vestibular affection appeared. A good overall control of vertiginous spells was achieved in 8 patients. Eight patients experienced complete hearing loss on the affected side, 1 experienced a slight worsening, and 1 had no hearing change. There was no correlation between the cumulative gentamicin dosage and the hearing loss. Our findings show that in terms of hearing loss and hospitalization time the continuous gentamicin application is inferior to other applications presented in the literature.

Administration, Topical↗
PubMed2001

Conjugated dienes: a critical trait of lipoprotein oxidizability in renal fibrosis.

BACKGROUND: We assessed whether a differential oxidizability of apolipoprotein B (apo B)-containing lipoproteins (LDL and VLDL) may explain the oxidative stress that we had observed at the onset of renal fibrosis in Zucker obese (ZO) rats (Nephrol Dial Transplant 2000, 15: 467--476). METHODS: Ex vivo copper-induced oxidation of lipoproteins was performed in 1-, 3-, and 9-month-old ZO and age-matched lean (ZL) rats. LDL/VLDL oxidizability was determined by spectrophotometry at 234 nm by monitoring the formation of conjugated diene hydroperoxides. RESULTS: A significant increase in lag time (reflecting the resistance to oxidation) was observed in ZO rats at 3 months while the maximal diene production (reflecting the amount of hydroperoxides formed during oxidation) was higher in ZO than in ZL rats as early as 1 month. Lipoproteins were larger in ZO than in ZL rats, as shown by their core to surface component ratio. Furthermore, ZO lipoproteins had increased vitamin E and polyunsaturated fatty acid (PUFA) content, with no change in vitamin E/PUFA ratio. CONCLUSIONS: Rather than oxidizability of apo B-containing lipoproteins, the ability of these molecules to produce high levels of conjugated dienes, which can act as toxic tissue messengers, appears to be a critical trait in the development of renal fibrosis in this rat model of obesity and renal fibrosis.

Alkenes↗
PubMed2001

Traces of perilymph detected in epipharyngeal fluid: perilymphatic fistula as a cause of sudden hearing loss diagnosed with beta-trace protein (prostaglandin D synthase) immunoelectrophoresis.

The incidence of perilymphatic fistula as cause of sudden hearing loss is not known. We present a case with sudden unilateral hearing loss associated with a positive beta-trace protein test of an epipharyngeal fluid sample. The patient presented with sudden sensorineural hearing loss on the right side. A stapedotomy had been performed nine months previously due to otosclerosis. Intravenous therapy for the treatment of sudden hearing loss was unsuccessful. At the time of sudden hearing loss, epipharyngeal fluid was collected using a Raucocel sinus pack. Investigation using rocket immunoelectrophoresis showed the presence of beta-trace protein. Upon repeating tympanoscopy there was no obvious labyrinthine fluid egress, but the oval window was sealed with fibrin sponge and fibrin glue. The patient's hearing improved over a period of five months.

Adult↗
PubMed2001

Expression of inducible nitric oxide synthase (iNOS/NOS II) in the hydropic vestibule after injection of keyhole limpet hemocyanin into the endolymphatic sac of guinea pigs.

This study was undertaken to examine the expression of inducible nitric oxide synthase (iNOS / NOS II) in the hydropic vestibule of guinea pigs. Animals were systemically sensitized with 500 microg of keyhole limpet hemocyanin. Two weeks after the first injection, keyhole limpet hemocyanin (100 microg/5 microl) was injected into the endolymphatic sac following the intradural approach, and the next day temporal bones were removed for the immunohistochemical examination. Endolymphatic hydrops was evidenced by the expansion of the Reissner's membrane in the cochlea after direct injection of keyhole limpet hemocyanin into the endolymphatic sac. Inducible nitric oxide synthase expression was increased in the sensory cells, supporting cells and vestibular ganglion cells, while temporal bones, where only phosphate buffered saline was injected, did not show any inducible nitric oxide synthase immunoreactivity. High levels of inducible nitric oxide synthase-catalyzed nitric oxide were detected prior to the development of the inner ear dysfunction. Our results suggest that the occurrence of inducible nitric oxide synthase immunoreactivity parallels the inner ear disturbance as seen in endolymphatic hydrops.

Animals↗
PubMed2000

[Central or vestibular vertigo? Diagnostic look through Frenzel glasses].

Vertigo is not a uniform symptom. The basis for a differentiated diagnosis is the history, which should record the frequency and duration of attacks. Further diagnostic investigations serve to differentiate between non-vestibular and vestibular (peripheral) forms of vertigo. Of essential importance is the determination of nystagmus with the aid of Frenzel lenses, with distinction being made between voluntary nystagmus and provoked nystagmus. These orientating examinations, which can be carried out by the family doctor, set the points for the further course. On account of the need for special equipment, such studies as the caloric tests, the swivel chair test, optokinetic tests or the tilting stage test, remain the domain of the specialist. They enable a definitive differentiation of an ENT illness from a neurological disorder.

Brain Diseases↗
PubMed2000

[Special forms of vertigo. Which therapy for which type of vertigo?].

Paroxysmal vertigo, permanent vertigo, positional and postural vertigo, and transient vertigo are special forms, which are differentiated by their temporal course. Paroxysmal vertigo, together with hearing impairment and noises in the ear, is typical of Menière's disease. Persistent vertigo often occurs after the loss of a peripheral vestibular end organ (e.g. after trauma of infection). In the case of positional and postural vertigo, a differentiation must be made between benign paroxysmal positional vertigo due to "wandering" otoliths, and orthostatic vertigo, which occurs on changing rapidly from a lying to a sitting position. The diagnosis is verified by Epley or Semont positional maneuvers. Confirmation of a cervical vertigo is provided by the de Kleijn and Nieuwenhuyse test. Brief episodes of vertigo (transient vertigo) occur after transient ischemia, for example when craning to look at a high building. In the acute stage, treatment of vestibular vertigo consists in the damping of the threshold for vestibular stimuli with antiemetics. For long-term treatment, antihistaminics and histamine-like substances have proven of value.

Diagnosis, Differential↗
PubMed2000

Systemic and local airways inflammatory response to endotoxin.

Endotoxin can be detected in house dust. Numerous studies have revealed that endotoxin exposure is a risk factor in increasing airway obstructive manifestations, both in occupational and domestic environments. In humans, inhalation of pure endotoxin induces systemic symptoms and a change in bronchial non-specific responsiveness, related with changes in blood and sputum inflammatory markers. However, some recent work suggests that, prior to airway disease development, endotoxin may have an atopy-protective effect. In particular, indoor endotoxin exposure in early life may protect against allergen sensitisation by enhancing type-1 immunity. Finally, since large variations between human immune responses to endotoxin have been reported, genetic mutations could alter the mechanisms of endotoxin recognition and contribute to the risk of atopy.

Allergens↗
PubMed2000

Detection of extracellular signal-regulated kinase1/2 in the inner ear of guinea pigs.

Growth factors, such as vascular endothelial growth factor (VEGF) and neurotrophins, recently identified in the inner ear of guinea pigs, exert their proliferative properties partly through activation of mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK1/2). In order to demonstrate presence of ERK1/2 in the inner ear we performed immunohistochemical analysis using specific antibodies to inactive and activated ERK1/2 on paraffin-sections of temporal bones from guinea pigs (n=5). In the cochlea clear immunoreactivity to inactive ERK1/2 was predominant in the spiral ligament, in the organ of Corti (intensive staining in supporting cells, faint staining in sensory cells) and limbus epithelium, while spiral ganglion cells and nerve fibres revealed weak staining. Activated ERK1/2 could be detected sparely in the spiral ligament exclusively. In the vestibule inactive ERK1/2 was located in the sensory epithelium, in nerve fibres and in vascular endothelium, while activated ERK1/2 could be detected in few nerve fibres and synaptic endings (buttons and calyces) on hair cells of the maculae and crests and in the endothelium of few blood vessels. These findings provide evidence that activated ERK1/2, as a general downstream signal of growth factors, may be contributed in the inner ear physiology.

Animals↗
PubMed2000

Immunohistochemical detection of vascular endothelial growth factor (VEGF) and VEGF-receptors Flt-1 and KDR/Flk-1 in the vestibule of guinea pigs.

Vascular endothelial growth factor (VEGF), known as an endothelial cell-specific mitogen, has been reported to be linked also to the NO/cGMP-pathway, which has been notified in the inner ear. Up to now, VEGF has not yet been described in the inner ear. We performed immunohistochemical analysis using specific antibodies to VEGF and to both known VEGF-receptors Flt-1 and KDR/Flk-1 on paraffin-sections of temporal bones from guinea pigs (n=5). Immunoreactivity of VEGF, Flt-1 and KDR/Flk-1 was detectable in a subpopulation of vestibular ganglion cells. VEGF could be found also in the endothelium of blood vessels, in fibrocytes of the lamina propria and in the neuroepithelium. Strong immuno-labelling to Flt-1 was evident in nerve fibres, vascular endothelium and in the neuroepithelium. Fibrocytes, endothelium of blood vessels, supporting cells and calyces in the sensory epithelium revealed immunoreactivity to KDR/Flk-1. These findings give evidence that VEGF, Flt-1 and KDR/Flk-1 are constitutively expressed in the vestibule.

Animals↗