Viggo Svane-Knudsen

Effect of Crossed Stapedius Reflex on Vibration of Mallear Handle in Man

The ear drum was made to vibrate using frequency-modulated sound pulses of 40 ms duration, and the vibration velocity of the tip of the mallear handle (umbo) was measured with laser vibrometry before and during stapedius muscle contractions (elicited by sound of 100 dB HL in the contralateral ear). The stapedius reflex caused: an attenuation of the mallear vibrations below 1 kHz, a slight enhancement of the vibrations between 300 Hz and 1,500 Hz. These effects of the stapedius reflex appear to be caused by an increased stiffness in the structures affecting the mallear vibrations.

Cholesteatoma : A morphologic study of stratum corneum lipids

Two different lipid-retaining fixation techniques permitted electron microscopic visualization of both intra- and extracellular lipids in cholesteatoma epithelium obtained from 25 patients. An increased number of intracellular lipid-containing Odland bodies was demonstrated, with a maximum in the basal layer of the stratum granulosum, while the superior layer contained substantially fewer organelles than are found in normal skin. At the stratum granulosum/stratum corneum interface lipids secreted from Odland bodies were found in sac-like invaginations along the cell membrane but premature exocytosis was also frequently observed. In the intercellular spaces of the stratum corneum, multiple long sheets of lamellar structures interrupted by slits or pores enclosed the keratinized corneocytes. The intercellular spaces seemed narrow and an extracellular barrier was not found until well above the stratum granulosum/stratum corneum interface. A similar distribution of Odland bodies and structure of intercellular lipids can occur in several dermatoses, where the formation and maintenance of the cutaneous permeability barrier are defective.Two different lipid-retaining fixation techniques permitted electron microscopic visualization of both intra- and extracellular lipids in cholesteatoma epithelium obtained from 25 patients. An increased number of intracellular lipid-containing Odland bodies was demonstrated, with a maximum in the basal layer of the stratum granulosum, while the superior layer contained substantially fewer organelles than are found in normal skin. At the stratum granulosum/stratum corneum interface lipids secreted from Odland bodies were found in sac-like invaginations along the cell membrane but premature exocytosis was also frequently observed. In the intercellular spaces of the stratum corneum, multiple long sheets of lamellar structures interrupted by slits or pores enclosed the keratinized corneocytes. The intercellular spaces seemed narrow and an extracellular barrier was not found until well above the stratum granulosum/stratum corneum interface. A similar distribution of Odland bodies and structure of intercellular lipids can occur in several dermatoses, where the formation and maintenance of the cutaneous permeability barrier are defective.

Surfactant-like lamellar bodies in the mucosa of the human nose

Specimens from the epithelium on the lateral wall of the human nose were examined under the electron microscope using a lipid and carbohydrate retaining method. In many of the ciliated epithelial cells and in some of the cells in the mucosal glands we identified multilamellated granules. These structures resembled lamellar bodies as found in normal alveoles where they are known to represent surfactant. The effect of phospholipid and the upper respiratory system is unknown but the similarities of these granules suggest to us a surface active function as it seems to play a role for normal Eustachian tube function.

Altered permeability barrier structure in cholesteatoma matrix

Abstract. The stratum corneum of the cholesteatoma epithelium comprises the greater part of the cholesteatoma matrix. The permeability barrier that militates against diffusion and penetration of infectious and toxic agents into and through the epithelium is situated here. The multiple long sheets of lamellar lipid structures filling the intercellular spaces mainly control the barrier function. The barrier in cholesteatoma epithelium is several times thicker than in unaffected skin but presents distinctive features of a defective barrier as seen in other scaling skin diseases. The intercellular spaces appear rather twisted, and the extra-cellular barrier is not found until well above the stratum granulosum/stratum corneum interface; thus, the transformation from secreted Odland-body contents is disturbed. Large dilatations of the extra-cellular space that are sometimes filled with an electron-dense material frequently occur. The corneocytes are shed in clusters, not as single cells. Further, lipid droplets and intracellular membranous material are occasionally seen. In spite of these clear signs of barrier dysfunction, it is unknown whether the thickness of the barrier compensates for the defect in barrier efficiency. Despite this, one cannot determine whether the stimulus to the increased lipid metabolic activity originates from the middle ear or from the ear canal.

Sympathetic Influence on the Normal Eustachian Tube: An Experimental Study in the Rat

A new variant of the inflation test of the Eustachian tube is presented; a constant air flow generator was constructed with minimal sensitivity to counterpressure, and variations in air pressure were measured, reflecting variations in Eustachian tube patency. By means of this test the effect of Otrivin (alpha 2-receptor stimulation) and Timacar (beta-receptor blocking) on the Eustachian tube was investigated with saline serving as reference. The following results were obtained: Otrivin lowers the opening pressure and the steady state pressure, and reduces the pressure drop during active opening. Timacar alone has no statistically significant effect on the Eustachian tube, but the combined effect of the two drugs is a more pronounced decrease in steady state pressure than the decrease seen following alpha 2-adrenergic stimulation alone. An explanation could be an alpha 2-receptor modulation by the beta-blocking agent. Consequently, autonomous regulation should be further studied in the search for a better understanding of Eustachian tube physiology.

Complement Defects in Patients with Chronic Rhinosinusitis

The complement system is an important part of our immune system, and complement defects lead generally to increased susceptibility to infections and autoimmune diseases. We have studied the role of complement activity in relation with chronic rhinosinusitis (CRS), and more specifically studied whether complement defects collectively predispose individuals for CRS or affect CRS severity. The participants comprised 87 CRS patients randomly selected from the general population, and a control group of 150 healthy blood donors. The CRS patients were diagnosed according to the European Position Paper on Rhinosinusitis and nasal Polyps criteria, and severity was evaluated by the Sino-nasal Outcome Test-22. Serum samples were analysed by ELISA for activity of the respective pathways of complement, and subsequently for serum levels of relevant components. We found that the frequency of complement defects was significantly higher among CRS patients than among healthy control subjects. A majority of Mannan-binding lectin deficient CRS patients was observed. The presence of complement defects had no influence on the severity of subjective symptoms. Our studies show that defects in the complement system collectively may play an immunological role related to the development of CRS. However, an association between severity of symptoms and presence of complement defects could not be demonstrated.

The distribution of free calcium ions in the cholesteatoma epithelium

The distribution of free calcium ions in normal skin and cholesteatoma epithelium was investigated using the oxalate precipitation method. In agreement with previous observations, we could demonstrate a calcium ion gradient in normal epidermis where the cells in stratum basale and spinosum reside in an environment containing relatively low concentrations of calcium ions, whereas the outer stratum granulosum contained abundant calcium. The concentration declined precipitously in the stratum corneum. In contrast, in cholesteatomas, the gradient was perturbed in some areas of the nucleated layers and areas appeared where oblong accumulations of free calcium ions were found basally in the stratum. These findings provide evidence that fluctuations in epidermal calcium in cholesteatoma epithelium may underlie the abnormal desquamation, may contribute to the formation of an abnormal permeability barrier and may regulate terminal events in epidermal differentiation.

Surfactant proteins A, B, C and D in the human nasal airway: associated with mucosal glands and ciliated epithelium but absent in fluid-phase secretions and mucus.

Aims: To investigate the presence of surfactant protein (SP) A, B, C and D in nasal airways and to determine whether the proteins exert their main functions in nasal secretions or in the deeper layers of the nasal mucosa. Methods: Volunteers were recruited from the Department of ENT Head and Neck Surgery, Odense University Hospital, Denmark. The study included 39 subjects. Nasal mucosal biopsies were analyzed by immunohistochemistry, and bronchoalveolar and nasal lavages, nasal brush biopsies and nasal mucus were analyzed for SP-A, -B, -C and -D by SDS-PAGE and Western blotting. The presence of SP-A and SP-D in the first three samplings were also analyzed by enzyme-linked immunosorbent assay. Results: In nasal mucosal biopsies, SP-A, -B, -C and -D were all demonstrated in the serous acini of the submucosal glands and in the surface epithelium. SP-D was detected in nasal brush biopsies, whereas the other SPs were absent. Moreover, SP-A, -B, -C and -D were absent in nasal lavage and mucus. Conclusion: SP-A, -B, -C and -D exert their protective effect in the ductal epithelium of the submucosal glands rather than in nasal secretions and mucus. Further studies are required to clarify the functions of these proteins in nasal secretory pathways for understanding upper airway diseases. i 2014 S. Karger AG, Basel

Stratum Corneum Barrier Lipids in Cholesteatoma

Specimens from primary cholesteatomas were examined under the electron microscope using a lipid-retaining method that is best suited for intracellular lipids and a method that is best for intercellular lipids. In the stratum granulosum of the squamous epithelium, a large number of Odland bodies emerged. When the corneocyte reaches the transitional stage to the stratum corneum, the Odland bodies accumulate near the cell membrane and discharge their contents of lipid and enzymes. The lipids are reorganized into multiple long sheets of lamellar structures that embrace the keratinized corneocytes, as seen in the formation and maintenance of the cutaneous permeability barrier. In this study we draw the attention to the facts that the cholesteatoma epithelium is capable of producing not only cholesterol, but also several lipids, and that the lipid molecules are organized in multilamellar structures in the intercellular space. In theory, the failure to desquamate seen in cholesteatomas could be caused by partial or total failure of Odland body delivery to the intercellular region, or to local breakdown of the permeability barrier.

The Impulse Response Vibration of the Human Ear Drum

Acoustical Dirac impulses (15 μsec duration, sound energy from 600 Hz to 25 kHz) are used under free field conditions for evoking impulse responses in the tympanic membranes of awake, unrestrained human volunteers. The impulse responses are analysed in the time- and frequency domains. The impulse responses within different frequency bands add to a total impulse response of complex shape (Fig. 3). The frequency spectrum of the vibration velocity of the mallear handle (umbo) shows several maxima in amplitude and corresponding deflections of phase, but the maxima are mainly caused by changes in the spectrum of the sound travelling to the ear drum. In contrast, the transfer function of the umbo (sound pressure to vibration) is smooth with only little variation in amplitude and a gradual development of phase. It is argued that the common notion of the middle ear as a low-pass filter is misleading.