[Modern treatment of otosclerosis. Stapes surgery performed by an experienced surgeon is the first choice].
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Clinical Competence↗
Biomedical subjects
U Mercke
Publications and source records attributed to U Mercke.
Effects of halothane on mucociliary activity in vivo.
The effect of halothane on mucociliary activity in the rabbit maxillary sinus in vivo was recorded photoelectrically. Administration of halothane (1%, 2% or 4%) into the maxillary sinus induced a temporary acceleration of mucociliary activity. The peak increase (39.1% +/- 9.1%, p < 0.05, n = 5) was seen after the 4% concentration. Long-term exposure (60 minutes) of the maxillary sinus to halothane (2%) first induced an increase of 28.4% +/- 4.6% (p < 0.05, n = 6), lasting approximately four minutes, and followed after about 15 minutes by a decrease of mucociliary activity. The maximum decrease during the 60-minute period was 19.6% +/- 2.8% (p < 0.05, n = 6). Mucociliary activity returned to its baseline level approximately 25 minutes after withdrawal of halothane. Halothane delivered to the rabbit through a tracheal cannula at 1.1% for 60 minutes did not impair mucociliary activity in the maxillary sinus. On the contrary, it initially stimulated mucociliary activity, 19.9% +/- 2.7% (p < 0.05, n = 5). There was also an initial increase in respiratory rate from 62 +/- 7.3 to 89 +/- 12.9 breaths per minute (p < 0.05), which was noticeable after approximately 10 seconds and lasted 4 to 5 minutes. The dose-dependent increase in mucociliary activity seen after short-term exposure to halothane is probably due to stimulation of afferent C fibers, because halothane may be considered an airway irritant. The reversible depressant effect seen after 15 minutes of exposure is in accordance with findings in previous studies in vitro. The mechanism by which halothane impairs mucociliary activity is at present not known. However, halothane administered to the lower airways does not impair mucociliary activity in the maxillary sinus, indicating that halothane affects the ciliated epithelium directly and that the state of anesthesia itself has no effect on mucociliary activity.
Anesthesia↗
Cyclic adenosine monophosphate stimulation of mucociliary activity in the upper airways in vivo.
Xanthine derivatives are known to accelerate mucociliary transport in the lower airways, probably by preventing degradation of cyclic adenosine monophosphate (cAMP) and thereby increasing its intracellular concentration. The purpose of this study was to investigate the effects of cAMP on mucociliary activity in the upper airways. The effect on the mucociliary activity in the rabbit maxillary sinus of the xanthine derivatives theophylline and enprophylline was compared to that of the cAMP analog dibutyryl cAMP. The compounds were administered into the maxillary artery, and the response was recorded with a photoelectric technique. Infusions of theophylline (1.0 and 10 mg/kg) increased mucociliary activity (22.8% +/- 5.9%, n = 6, and 21.6% +/- 4.9%, n = 7, p < .05, respectively). Infusions of enprophylline (1.0 and 10.0 mg/kg) accelerated mucociliary activity (at the highest dosage tested, 24.3% +/- 4.1%). Infusions of dibutyryl cAMP (0.1 and 1.0 mg/kg) stimulated mucociliary activity, with the maximum increase (20.1% +/- 3.0%, n = 13, p < .05) being observed at a dosage of 0.1 mg/kg. The infused substances increased mucociliary activity within 1 minute after the start of the infusion, the duration of the response being approximately 20 minutes for theophylline, 22 minutes for enprophylline, and 12 minutes for dibutyryl cAMP. The present results support the view that cAMP is involved in regulating mucociliary activity in the upper airways. It remains to be elucidated whether xanthines such as theophylline and enprophylline are beneficial in upper airway disease in which mucociliary function is impaired (eg, chronic sinusitis).
Animals↗
Hyaluronic acid in middle ear surgery.
The efficacy of hyaluronic acid when utilized in tympanoplasty was investigated in a multicenter, randomized, prospective patient blinded study. Of the 117 patients who completed the study, a majority (76) were treated with myringoplasty, 26 with myringoplasty combined with ossiculoplasty, and 15 with ossiculoplasty alone. The patients were evaluated by the operating surgeon up to 3 months following surgery, when the final assessment was made. The patients were divided into three groups: group 1 was treated with hyaluronic acid, 1 percent; group 2 with hyaluronic acid, 1.9 percent; and group 3 constituted the control where no hyaluronic acid was used at all. In the two test groups, utilizing hyaluronic acid, no gelatinous sponge was allowed to be left in the middle ear after surgery, whereas the control group was operated according to standard principles. The three groups were compared after the termination of the study as regards quality of healing and their hearing results. It could be concluded that the healing process within the middle ear and the tympanic membrane, as well as the hearing ability, was similar in all three groups. Thus no statistically significant differences could be obtained between the patient groups in which hyaluronic acid had been utilized in any concentration and the control group operated according to standard routine. This finding does not exclude, however, that hyaluronic acid might have a place in tympanoplastic surgery of today, since the long-term results were not evaluated here.
Adolescent↗
The effect of noradrenaline on mucociliary activity in the rabbit maxillary sinus.
The effect of noradrenaline (NA) on mucociliary activity in the rabbit maxillary sinus was investigated in vivo by injecting it at increasing dosages (10(-11) to 10(-4) mol/kg) into the maxillary artery, the mucociliary response being recorded photoelectrically. NA increased mucociliary activity at a dosage of 10(-5) mol/kg, the maximal increase being 16.1 +/- 2.6%. The NA-induced stimulation of mucociliary activity had a latency of 20 s, and the activity returned to base-line level within 3 min. Pretreatment with the alpha-antagonist phentolamine (0.2 and 1.0 mg/kg) or the cholinergic antagonist atropine (1 mg/kg) did not alter mucociliary response to NA. Blockade with the beta-antagonist propranolol did not significantly reduce the maximal response to NA, which was 16.1 +/- 2.6% before and 11.1 +/- 3.0% after pretreatment with propranolol (n = 7; p = 0.2). In contrast, pretreatment with the prostaglandin-synthesis inhibitor indomethacin reduced the response from 12.9 +/- 2.9% to 6.3 +/- 1.3% (n = 6; p < 0.05), suggesting that at high dosages NA stimulates mucociliary activity via the cyclo-oxygenase pathway.
Animals↗
Neuropeptide Y in the rabbit maxillary sinus modulates cholinergic acceleration of mucociliary activity.
The distribution of neuropeptide Y (NPY)-immunoreactivity was investigated in the rabbit maxillary sinus and adjacent ganglia. A moderate supply of NPY-containing nerve fibers occurred around seromucous glands and a denser supply around small blood vessels. Only a few immunoreactive nerve fibers were seen beneath the epithelium. Double immunostaining showed that vasoactive intestinal peptide (VIP) coexisted with NPY in the nerve fibers surrounding blood vessels and seromucous glands. NPY-containing nerve cell bodies were numerous in the superior cervical ganglion, and moderately numerous in the sphenopalatine ganglion. The finding of NPY-containing neurons in the latter parasympathetic ganglion suggests that NPY may influence the cholinergic regulation of mucociliary activity. The effect of NPY on the mucociliary activity of the maxillary sinus in connection with cholinergic stimulation has therefore been investigated in vivo using a photoelectric technique. At dosages of 2.5 and 5.0 micrograms/kg, the ganglionic stimulant nicotine bitartrate, which increases mucociliary activity by a cholinergic pathway, accelerated mucociliary activity by 28.0 +/- 7.5% and 36.8 +/- 6.2%, respectively. In the same experiment repeated during infusion of NPY (0.1 microgram/kg/min), the increase in mucociliary activity was reduced to 10.8 +/- 2.3% and 28.9 +/- 7.1%, respectively. Infusion of NPY did not affect the stimulating effect on mucociliary activity by bolus injections (0.1 and 0.5 microgram/kg) of the cholinergic agonist, methacholine. It is concluded that NPY-like immunoreactivity is present in nerve fibers in the rabbit maxillary sinus and in neurons in the sympathetic and parasympathetic ganglia that supply the nose and paranasal sinuses. NPY attenuates the effect of nicotine on mucociliary activity, probably via a prejunctional mechanism, and may act as a modulator of cholinergic regulation of the mucociliary system.
Animals↗
[The choice of surgical method should be based on patients' demands and conditions].
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Hearing↗
Sympathetic nerve stimulation influences mucociliary activity in the rabbit maxillary sinus.
The effect of preganglionic sympathetic nerve stimulation on mucociliary activity in the rabbit maxillary sinus was investigated in vivo. Response to nerve stimulation was recorded photoelectrically and expressed as a percentage of the basal mucociliary activity prior to stimulation. Nerve stimulation (15 V, 5 ms) for 60 s at 2, 10 and 20 Hz stimulated mucociliary activity, the maximum increase being 21.1 +/- 1.3% at 20 Hz, an increase that pretreatment with the cholinergic antagonist atropine reduced to 14.5 +/- 2.4%, suggesting that part of the response involves cholinergic mechanisms. Nerve stimulation (10 Hz) of animals pretreated with the beta-adrenoceptor antagonist propranolol reversed the mucociliary response from an increase to a decrease (-10.6 +/- 1.6%), indicating the involvement of beta-receptors in the nerve-evoked increase. Pretreatment with the alpha-adrenoceptor antagonist phentolamine had no effect on response to nerve stimulation. Rabbits given a combined atropine, propranolol and phentolamine blockade manifested decreased mucociliary activity in response to nerve stimulation (-10.6 +/- 2.1%). Guanethidine pretreatment blocked the effect of nerve stimulation on mucociliary activity, including the observed decrease after combined blockade, indicating the effect to be mediated via sympathetic nerve fibres. The decrease in mucociliary activity in response to nerve stimulation after combined cholinergic-, beta-, and alpha-adrenoceptor blockade suggests the presence of a nonadrenergic, non-cholinergic inhibitory mechanism. It is possible that this effect is mediated by release of neuropeptide Y, as intraarterial injections of neuropeptide Y reduce mucociliary activity in the rabbit maxillary sinus, and as neuropeptide Y is released in the upper airways upon sympathetic nerve stimulation.
Animals↗
The effect of neuropeptide Y on mucociliary activity in the rabbit maxillary sinus.
The effect of neuropeptide Y (NPY) on mucociliary activity in the rabbit maxillary sinus was investigated in vivo by injecting NPY at increasing dosages into the maxillary artery, response being recorded photoelectrically. At dosages of 0.1-5.0 micrograms/kg, NPY reduced mucociliary activity dose-dependently, the maximum decrease being 14.6 +/- 1.8%, at a dosage of 5.0 micrograms/kg. The NPY-induced reduction of the mucociliary activity manifested brief latency, the peak effect occurring within 3 min followed by a slow return to the baseline value 4-9 min after injection. The response of mucociliary activity to NPY remained unaffected by pretreatment with the alpha-adrenergic antagonists yohimbine (alpha 2) at 100.0 micrograms/kg and phentolamine (alpha 1 + alpha 2) at 0.2-1.0 mg/kg, indicating that the effect of NPY is not mediated via alpha-receptors. Pretreatment with the calcium antagonist nifedipine at 100.0 micrograms/kg inhibited the effect of NPY, suggesting that the NPY-induced decrease may be calcium dependent.
Adrenergic alpha-Antagonists↗
Histamine stimulation of mucociliary activity in the rabbit maxillary sinus.
The in vivo effect of histamine on mucociliary activity in the rabbit maxillary sinus was investigated by injecting histamine into the maxillary artery and recording the responses with a photoelectric technique. Histamine stimulated the mucociliary activity dose-dependently in the dose range 10 to 1,000 micrograms/kg. The maximum response was 31.6% +/- 3.7% at a dose of 50 micrograms/kg. The histamine-induced stimulation of the mucociliary activity was characterized by a short latency with a peak response within 1 to 2 minutes and a slow decline lasting about 5 minutes. The response displayed tachyphylaxis. Cholinergic blockade with atropine did not affect the response to histamine. Blockade of H1 receptors with pyrilamine abolished the response to histamine, whereas blockade of H2 receptors with cimetidine was without effect. The H2 agonist dimaprit failed to stimulate the mucociliary activity. It is concluded that histamine stimulates the mucociliary activity in the rabbit maxillary sinus via H1 receptors.
Animals↗
Growth potential of acoustic neuromas.
Tumor samples from 32 patients with acoustic neuroma operated with translabyrinthine approach were analyzed with flow cytometric technique with respect to ploidy and cell cycle phase distribution. In all cases the diagnosis of acoustic neuroma was verified histologically, two patients had Recklinghausen's disease. None of the tumors showed aneuploid cell lines. Median S-phase fraction was 6.8% (range 1.4 to 19.9%). The spread of S-phase values had a greater range for the smaller tumors (volume less than or equal to 2 cm3) of the material. There was no correlation neither between the fraction of cells in S-phase and age of the patient, nor between the fraction of cells in S-phase and tumor size. The present finding with a great variability in S-phase values does not support an expectant attitude regarding surgical intervention in patients with acoustic neuromas.
Age Factors↗
VIP potentiates cholinergic effects on the mucociliary system in the maxillary sinus.
The neuropeptide vasoactive intestinal polypeptide (VIP), which is found in a population of cholinergic parasympathetic neurons in the airways, has no effects per se on mucociliary activity. In order to test the hypothesis that VIP may modulate cholinergic regulation of the mucociliary system, VIP was infused intraarterially (8.4 pmol/kg/min), and the response to challenges with methacholine in the maxillary sinus of rabbits were recorded with a photoelectric technique. Occurrence of VIP-like immunoreactivity in the rabbit maxillary sinus, maxillary nerve, and sphenopalatine ganglion was investigated. Immunoreactivity against VIP was found in nerve fibers in the subepithelial layer of the maxillary sinus and in numerous nerve cell bodies in the sphenopalatine ganglion. Infusion of VIP potentiated the mucociliary increase induced by methacholine. The mucociliary wave frequency change increased from 6.1% +/- 1.7% to 13.3% +/- 3.9% (0.01 micrograms/kg methacholine), from 11.6% +/- 3.6% to 18.8% +/- 2.2% (0.05 micrograms/kg) and from 17.0% +/- 3.0% to 27.4% +/- 3.6% (0.1 micrograms/kg). Both peak responses and response durations increased during infusions. In contrast, the vasodilating agent papaverine sulphate did not influence the mucociliary response to methacholine. The modulating effect of VIP on the mucociliary system, taken together with the morphologic observations, suggest that VIP may have a physiologic role in the regulation of the mucociliary system in the maxillary sinus.
Animals↗
Translabyrinthine acoustic neuroma surgery as performed by the otoneurosurgical group at Lund University Hospital.
The Lund otoneurosurgical group has operated 97 out of 118 pontine angle tumours using the translabyrinthine approach originally described by House. The pre- and postoperative evaluation of these 97 patients is described. The traditional classification of acoustic neuromas, the results of the reported surgery and complications are discussed.
Adolescent↗
Stimulation of C fibers by ammonia vapor triggers mucociliary defense reflex.
The neuropeptide substance P (SP) released from airway sensory C fibers accelerates mucociliary activity, and C fibers in the airways are stimulated by various irritants including ammonia (NH3) vapor. The short-term effects of NH3 vapor on mucociliary function in the in the maxillary sinus of rabbits anesthetized with urethane were investigated by a photoelectric technique. Challenges with 1.5 ml NH3 increased mucociliary activity dose-dependently, the maximal response being 26.6 +/- 1.6%. The increase appeared within 1.3 +/- 0.3 s after exposure. Atropine and hexamethonium decreased the effect of NH3, indicating that part of the response was mediated by cholinergic effector neurons, but a noncholinergic effect clearly remained. Pretreatment with large doses of capsaicin (13 mg i.a.) abolished the response, whereas the SP antagonist (D-Pro2, D-Trp7,9) SP inhibited the noncholinergic response. Challenges with NH3 vapor also decreased the respiratory rate. An identical response was noticed during injections with the C fiber stimulant capsaicin. Together these results indicate that NH3 vapor triggers a mucociliary protective reflex in the airways, involving capsaicin-sensitive C fibers. The recorded increase of mucociliary activity is probably due to the combined effect on the mucociliary system of both SP and acetylcholine released from the afferent and efferent part of the reflex arc, respectively.
Ammonia↗
The role of neurokinin A and calcitonin gene-related peptide in the mucociliary defence of the rabbit maxillary sinus.
Substance P (SP) released from sensory C-fibres in the airways increases the mucociliary (m.c.) activity in the rabbit maxillary sinus. The purpose of the present study was to investigate the m.c. effects of two other neuropeptides, coexisting with SP in sensory neurones, neurokinin A (NKA) and calcitonin gene-related peptide (CGRP). NKA increased the m.c. activity dose-dependently (dose range 0.1-5.0 micrograms/kg) the maximum increase being 33.6 +/- 6.0%. The effect was inhibited by pretreatment with the tachykinin antagonist (D-Pro2, D-Trp7,9)SP, but not with atropine or hexamethonium. Thus NKA released from sensory C-fibres may contribute to the non-cholinergic increase of m.c. activity observed after C-fibre stimulation. In contrast CGRP did not influence the m.c. activity. Neither did it influence the responses to NKA or SP. It is concluded that CGRP is unlikely to be involved in the control of m.c. function.
Animals↗
The cholesteatomatous ear one year after surgery with obliteration technique.
Fifty-seven patients with middle ear cholesteatoma were treated surgically by eradicating the cholesteatoma after a canal wall-down procedure had been performed. During the same session the canal wall was rebuilt with autologous bone, the tympanic membrane repaired with fascia, and the mastoid cavity and epitympanic space obliterated with autologous cortical mastoid bone chips and a retroauricular, anteriorly based muscle flap. One year later a second look procedure was performed in all the patients (N = 57), which permitted the anatomic effects of the obliteration operation to be mapped out before ossicular reconstruction was undertaken. At three, six, and twelve months after the first operation any secretion from the ear was recorded. Recurrent cholesteatoma was not found in any single case, residual cholesteatoma in only three cases (5.3%). The tympanic membrane was intact in fifty-four cases (94.7%) and perforated in three, none of which was combined with a residual cholesteatoma. Even though twenty-four of the fifty-seven cases had a secreting ear before the eradicating operation, fifty-six (98.2%) stayed dry during the year of observation between the two operations. Therefore, with very few exceptions, a dry, cholesteatoma-free ear and an intact tympanic membrane may be expected one year postoperatively in patients with middle ear cholesteatoma surgically treated using the described obliteration technique.
Adolescent↗
Effects of neurokinin A and calcitonin gene-related peptide on mucociliary activity in rabbit maxillary sinus.
Substance P (SP) released from sensory C-fibers in the airways increases the mucociliary (m.c.) activity in the rabbit maxillary sinus. The purpose of the present study was to investigate the m.c. effects of two other neuropeptides, coexisting with SP in sensory neurones, neurokinin A (NKA) and calcitonin gene-related peptide (CGRP). NKA increased the m.c. activity dose-dependently (dose range 0.1-10.0 micrograms/kg, 88 pmol to 8.8 nmol/kg), the maximum increase being 41.9 +/- 2.6%. The effect was inhibited by pretreatment with the tachykinin antagonist (D-Pro2,D-Trp7,9)SP, but not with atropine or hexamethonium. Thus NKA released from sensory C-fibers may contribute to the non-cholinergic increase of m.c. activity observed after C-fiber stimulation. In contrast CGRP did not influence the m.c. activity. Neither did it influence the responses to NKA or SP. It is concluded that CGRP is unlikely to be involved in the control of m.c. function.
Animals↗
Postoperative CT findings in acoustic neurinomas operated upon by a translabyrinthine approach.
The findings at CT examinations, performed on 46 patients with acoustic neurinomas about 6 months after translabyrinthine surgery, were analyzed and compared with preoperative findings. Direct as well as indirect signs of expansion had disappeared postoperatively. Bulging of cerebellar tissue towards the operative defect in the petrous bone, a finding not connected with local adhesions, was notable. Hypodensity in the vicinity of the removed tumor occurred either due to local widening of the subarachnoid space or due to changes within the cerebellar parenchyma. Local and general widening of the fourth ventricle as a sign of atrophy was a frequent finding.
Adolescent↗