[Voice-improving laser-surgical therapy in amyloidosis of the larynx]

Laryngeal amyloidosis is relatively uncommon, accounting for only 0.2-1.5% of all laryngeal tumours. Hoarseness, dysphagia and stridor are potential clinical symptoms. A systemic amyloidosis should be excluded even though symptoms are only apparent in the head and neck region. For the localised form, surgical excision of the excess tissue is performed. We discuss the development of the disease, together with its diagnostics and therapy, based on the case report of a 42 year old female patient.

[Influence of the head position in laryngoscopy]

INTRODUCTION

The aim of this study was to determine the optimal position of the head during larygoscopy.

MATERIAL AND METHODS

During fiberoptic evaluation of the larynx, the head position of eight subjects (5 male, 3 female) was changed systematically. The influence of reclining and anteversion, tilting and rotation of the head on the quality of the endoscopic images was determined.

RESULTS

The vocal tract became wider and the view onto the glottis could be improved by reclining the head and anteversion of the chin. On rotation of the head, the hypopharynx of the same side became narrower. This is well known and is used worldwide in the therapy of dysphagia.

DISCUSSION

Positioning of the patient is important in laryngoscopy. Reclining the head and forward inclination of the trunk (horizontal axis of the mouth) seems to be the best position for obtaining an optimal view onto the glottis.

Ausgepr�gte beidseitige mesocochle�re Schwerh�rigkeit von 40?45�dB bei regelrechten TEOAE, DPOAE und unauff�lliger Click-BERA

An objective screening method for assessment of inner ear function of babies and small children can be carried out by measuring TEOAE and DPOAE. In particular, TEOAE can be used as a cheap and quick method to determine, with very high sensitivity and moderate specificity, whether middle to severe peripheral hearing impairment is present. In order to assess the threshold more precisely, the click-BERA is routinely used. We present a case report of a 6 year old girl with regular TEOAE and DPOAE, and who also had bilateral normal thresholds in the click-BERA. With subjective audiometry, the girl could be diagnosed having bilateral mesocochlear hearing impairment (so called cookie-bite audiogram) ranging at 40-45 dB. The child was helped considerably by fitting of hearing aids bilaterally. In order to determine the auditory ability of children and to provide adequate care, subjective as well as objective tests should be used.

Avian metapneumovirus excretion in vaccinated and non-vaccinated specified pathogen free laying chickens

Vaccinated and non-vaccinated specified pathogen-free White Leghorn laying chickens were challenged at peak of lay by the intravenous or oculonasal route with a virulent avian metapneumovirus (aMPV) subtype B chicken strain. Severe clinical signs and a drop in egg production were induced in the non-vaccinated intravenously challenged birds whereas the vaccinates were not affected. Live virus excretion was demonstrated in the faeces and respiratory tract of non-vaccinated hens for up to 7 days post intravenous challenge. After oculonasal challenge, virus excretion could only be demonstrated in the respiratory tract for up to 5 days. No live virus excretion was found in either the faeces or the respiratory tract of vaccinated birds. Concurrent with live virus isolation, the presence of viral RNA was demonstrated by single reverse transcription-polymerase chain reaction (RT-PCR). Nested RT-PCR was more sensitive and viral RNA could be detected in non-vaccinated birds up to 28 days post either intravenous or oculonasal challenge, at which time the experiment was terminated. Viral RNA was detected for up to 12 days in vaccinated birds. This is the first study investigating excretion of aMPV and viral RNA in vaccinated and non-vaccinated laying hens challenged under experimental conditions. The results are of importance with regard to the persistence of aMPV and the appropriate diagnostic detection method in laying birds.

Diagnostik von psychogenen H�rst�rungen im Kindesalter

In comparison with organic hearing loss, which is commonly reported, non-organic hearing loss is under-represented in the literature. The audiological results for 20 patients, aged between 6 and 17 years (mean 11.3), with psychogenic hearing disturbances were analysed prospectively. In 17 cases, the disturbance was bilateral and in three cases unilateral. In no case was the result of an objective hearing test exceptional, while a hearing threshold of between 30 and 100 dB was reported in single ear, pure-tone audiograms. In 12 cases, single ear speech audiograms were unexceptional. Suprathreshold tests, such as the dichotic discrimination test or the speech audiogram with noise disturbance, could lead to a clearer diagnosis in cases of severe psychogenic auditory impairment. In half of the patients, a conflict situation in the school or family was evident. After treatment for this conflict, hearing ability returned to normal. There was no improvement for six patients.

[Reinke edema--helpful in unilateral recurrent laryngeal nerve paralysis?]

We report on a 57-year-old teacher who consulted us for her known unilateral recurrent nerve paralysis subsequent to strumectomy. Video laryngoscopic and stroboscopic examinations revealed Reinke's edema in addition to the left-sided immobile vocal fold with maintenance of good vocal function. Because of the left-sided Reinke's edema, complete glottal closure was possible although the left vocal ligament remained slack. Surgical removal of the vocal fold edema in this case would presumably result in considerable impairment of vocal function. This example illustrates that in selected cases Reinke's edema can contribute to maintenance of phonation in unilateral vocal fold paralysis. In these cases, indication for edema surgery should be very restrictive and should always take the vocal function into consideration.

[Oropharyngeal vocal tract space during singing--comparison of tactile-kinesthetic and auditory perception with objective endoscopic findings]

BACKGROUND

In this study we compared the perceived diameter of the vocal tract's oropharyngeal part with the diameter that was determined endoscopically.

METHODS

28 singers (13 male, 15 female) were examined with transnasal fiberscopic pharyngoscopy while singing the vowels /a/, /i/ and /u/ in 4 different timbres (normal, opened, covered, dumpled) and 3 different pitches (chest/modal register, subjective comfortable pitch for singing, head/falsetto register). The tactile-kinesthetic and auditive rating of the singers, the auditive rating of a singing teacher and the visual-endoscopic analysis of three laryngologists were compared.

RESULTS

The tactile-kinesthetic and auditory self-perception of the singers was quite different from the auditive perception of a singing teacher and visual endoscopic findings of the laryngologists. The singers had the impression that the different singing timbres (normal, opened, covered, dumpled) influence oropharyngeal vocal tract space during singing. They judged the vowel itself and the pitch as having very little influence. Based on his auditory perception, the singing teacher also rated that the timbre plays an important role for the oropharyngeal vocal tract space but he found vowels to be the parameter with the greatest impact. Via visual endoscopic examination we found that, among the three parameters (vowel, timbre, pitch), the different vowels are most influential on the oropharyngeal vocal tract space. Analysis of video sequences revealed that pitch and timbre are less important.

CONCLUSION

Subjective tactile-kinesthetic and auditory perception of the singers differs from auditory perception of the singing teacher as well as from endoscopic findings. The endoscopically determined oropharyngeal vocal tract space during singing the vowels /i/ or /u/ tends to be larger compared to the oropharyngeal vocal tract space while singing the vowel /a/.

[Non-invasive screening for GJB2 mutations in buccal smears for the diagnosis of inherited hearing impairment]

BACKGROUND

Approximately 1 out of 1000 children is affected by severe or profound hearing impairment at birth. In the last years it has been shown that more than 50 % of inherited prelingual, sensorineural hearing impairment may be attributed to genetic defects. Most commonly, the GJB2 gene (chromosome 13q11) that encodes connexin 26 (Cx26) is affected. Cx26 is crucial for the formation of gap junctions which play an important role in the intercellular exchange of electrolytes. A variety of autosomal recessive GJB2 mutations associated with inherited hearing impairment has meanwhile been identified. The most common GJB2 mutation in Caucasian populations, 35delG accounts for the majority of cases and has a carrier frequency of more than 2.5 %. Other distinct mutations account for hearing impairment in other parts of the world.

MATERIAL AND METHODS

We examined in 59 Caucasian and Ghanaian individuals whether DNA recovered from buccal smears was appropriate for genetic testing by polymerase-chain reaction (PCR) based DNA-sequencing.

RESULTS

Buccal smears could be taken conveniently in all cases, even from small babies. In 53 out of 59 samples the material recovered from buccal smears could be subjected to PCR of the second exon of the GJB2 gene and subsequent DNA-sequencing. GJB2 mutations were identified in 34 patients. 13 Caucasian individuals exhibited the most common mutation 35delG. In addition, four cases of the rare W24X and each one heterozygous case of the V153I- and the L90P mutation were found. In two African individuals the 35insG mutation was detected. All other African patients had mutations exclusively identified in Ghana so far with the exception of R143W. R143W accounts for most cases of profound deafness in Ghana and has been identified in low frequencies in other ethnic groups as well.

CONCLUSION

Screening for GJB2 mutations in DNA recovered from buccal smears of individuals with inherited hearing impairment offers an easy, non-invasive method for early diagnosis and a basis of genetic counselling.

[Physical and technical elements of short-interval, color-filtered double strobe flash-stroboscopy]

INTRODUCTION

Quantitative measurement of vocal fold movements can be done either with high-speed imaging or with short interval, color-filtered double strobe flash-stroboscopy. The physical and technical elements of this new technique are described.

METHODS

Two special strobe units (KAY Elemetrics RLS 9100) are used in a master-slave configuration. In this way an adjustable interval of 0.1-2.0 ms between flashes is introduced. The strobe flashes are color filtered and are separated by a brief interval. By this means a double exposure is created in each video frame.Real-time visualization of opening and closing velocities over the entire length of the vocal fold from anterior to posterior is possible. Quantification is possible off-line after image calibration.

CONCLUSION

Short-interval, color-filtered double-strobe flash stroboscopy allows quantitative measurement of the velocity of vocal fold movements during vibration at different pitches and sound pressure levels (SPL). Images gained with this new technique provide information about a dynamic property (velocity) of the vocal fold within a single image.Therefore, its use could be helpful from the aspect of clinical documentation.

The use of PCR combined with restriction enzyme analysis to characterize fowl adenovirus field isolates from northern India

Ten fowl adenoviruses (FAVs), isolated from suspected cases of inclusion body hepatitis (IBH) in quails and broilers, were characterized by a hexon-based polymerase chain reaction (PCR) combined with restriction enzyme analysis (REA) of the amplified DNA fragments. All the isolates could be detected using H1/H2 and H3/H4 primer sets. Amplification of DNA with H1/H2 and H3/H4 primer sets resulted in fragments of approximately 1219 bp and 1319 bp, respectively. HaeII digestion of the H1/ H2 PCR products and HpaII digestion of the H3/H4 PCR products characterized all the isolates in FAV groups, known from genomic typing using the whole DNA. For some of the isolates, neutralization tests were used to confirm these results. The results revealed that, as well as FAV serotype 1, which is the sole member of DNA group A, FAVs of DNA group E are also associated with IBH in poultry in northern India. The FAV specific PCR combined with REA was found to be very useful in investigating the epidemiological situation in the field. It was even possible to define mixed infections with more than one FAV.

The pattern of cone pedicles and horizontal cells in the retina of the European anchovy, Engraulis encrasicolus L. (Engraulididae, Clupeiformes)

We have studied the architecture of polycone pedicles and their postsynaptic horizontal cells in the European anchovy using serial reconstruction by means of thin-sections from the cone outer segments to the outer plexiform layer. Within this layer there is a tesselated arrangement of pedicles in two strata, one made by the long-cone pedicles and one by those of the short-cones. The two pedicle types differ in the architecture of their synaptic sites. The long-cones possess two ribbon clusters corresponding to two bunches of subsynaptic dendrites, while the short-cones have only a single ribbon cluster innervated by a single group of dendrites. In addition, telodendria specifically connect the cone pedicles of neighbouring rows. Among the horizontal cells three classes arranged in separate levels can be distinguished. Serial reconstruction results suggest that first level horizontal cells contact long-cones preferentially. Among bipolar cells with an oval shaped dendritic field another type is found with a rectangular field of polycone-parallel dendritic combs. These findings indicate that the uncommon cone structures of engraulidids, which probably subserve polarization contrast vision, are correlated with a peculiar geometry of the outer plexiform layer.

Inhibition of human natural killer cell activity by cereulide, an emetic toxin from Bacillus cereus

The lipophilic toxin, cereulide, emitted by emetic food poisoning causing strains of Bacillus cereus, is a powerful mitochondria toxin. It is highly lipophilic and rapidly absorbed from the gut into the bloodstream. We tested how this toxin influences natural killer (NK) cells, which are important effectors in defence against infections and malignancy. Cereulide inhibited cytotoxicity and cytokine production of natural killer cells, caused swelling of natural killer cell mitochondria, and eventually induced natural killer cell apoptosis. The suppressive effect on cytotoxicity was fast and toxic concentration low, 20-30 microg/l. As the emesis causing concentration of cereulide is around 10 microg/kg of total body mass, our results suggest that emesis causing or even lower doses of cereulide may also have a systemic natural killer cell suppressive effect.