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Biomedical subjects

M Hess

Publications and source records attributed to M Hess.

At least 37 records · Page 2Linked to original sources

Limited pathogenicity of Usutu virus for the domestic chicken (Gallus domesticus).

In summer 2001, Usutu virus (USUV), a mosquito-borne flavivirus, was isolated for the first time in Europe during a mortality incident among Eurasian blackbirds (Turdus merula) in Austria. Chickens are frequently used as sentinel animals for arbovirus surveillance systems. In the present study, the pathogenicity of USUV for specific pathogen free chickens was investigated. Ten 2-week-old chickens were inoculated intravenously with 0.1 ml inoculum containing 10(3) median (50%) tissue culture infectious dose of USUV strain Vienna 2001-blackbird (939/01). Clinical signs, viraemia, gross and microscopic lesions, contact transmission and immunological response were evaluated. No clinical signs were observed in the USUV-inoculated animals during the experimental period. Pathological examination showed moderate splenomegaly and follicular infiltrates in the liver of several inoculated animals. Mild non-suppurative encephalitis was observed in the brain tissue of one virus-inoculated chicken examined 7 days post inoculation (d.p.i.). USUV nucleic acid was detected by reverse-transcriptase polymerase chain reaction in the organs of six inoculated chickens, although immunohistochemistry for flavivirus antigen was negative in all tissues from all chickens. Virus shedding was shown in three inoculated birds by detecting USUV RNA in cloacal swabs of two chickens at 5 d.p.i., and in the cloacal and pharyngeal swabs of one chicken at 7 d.p.i. Based on detection of viral RNA in peripheral blood mononuclear cells, viraemia was detected only in two chickens (at 7 d.p.i.). Only one of the inoculated chickens developed an antibody response. There was no evidence of virus transmission to chickens kept in contact with inoculated birds. No USUV was isolated from in-contact birds and all in-contact and control animals lacked USUV-specific antibodies. The present data suggest that domestic chickens are not at risk of developing clinical disease following USUV infection and that chickens are unlikely to be useful for sentinel purposes in USUV surveillance programmes.

Animals↗

Accumulation of Mn(II) in Deinococcus radiodurans facilitates gamma-radiation resistance.

Deinococcus radiodurans is extremely resistant to ionizing radiation. How this bacterium can grow under chronic gamma radiation [50 grays (Gy) per hour] or recover from acute doses greater than 10 kGy is unknown. We show that D. radiodurans accumulates very high intracellular manganese and low iron levels compared with radiation-sensitive bacteria and that resistance exhibits a concentration-dependent response to manganous chloride [Mn(II)]. Among the most radiation-resistant bacterial groups reported, Deinococcus, Enterococcus, Lactobacillus, and cyanobacteria accumulate Mn(II). In contrast, Shewanella oneidensis and Pseudomonas putida have high iron but low intracellular manganese concentrations and are very sensitive. We propose that Mn(II) accumulation facilitates recovery from radiation injury.

Culture Media↗

[Vocal cord dysfunction. An important differential diagnosis to bronchial asthma].

Vocal cord dysfunction (VCD) is described as a functional disorder of the vocal folds which leads to an intermittent, inspiratory 'paradoxical' glottal closure. We report on three women with frequent repetitive shortness of breath attacks caused by VCD. This was diagnosed by transnasal videofiberendoscopy, with glottal closure being seen during inspiration. Because of the different etiologies, one of the patients was treated with breathing and speech therapy, another received Omeprazol for laryngopharyngeal reflux, and the third was treated by intralaryngeal botulinum toxin injections. All three patients showed a reduction in attacks. Clinically, VCD seems to mimic asthma. However, with a thorough patient history and diagnostics, especially with transnasal laryngoscopy during a (triggered) attack, a precise diagnosis seems possible.

Adult↗

[Pronounced bilateral mesocochlear hearing impairment from 40-45 dB in spite of regular TEOAE, DPOAE and inconspicuous 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.

Audiometry↗

[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.

Adult↗

[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.

Adult↗

[Is there a consensus in the division of the vocal folds in thirds?].

INTRODUCTION: In clinical routine we have noticed a disagreement of ENT-specialists and phoniatricians in the division of the vocal folds in thirds. To show if there is consensus in this field by the german phoniatricians this study was done. MATERIAL AND METHODS: In two parts of a study, a pilot study and a follow up study, we sent twelve different images of the larynx to all german phoniatricians. In six of these images the physicians should set the marks of the ventral and dorsal limitation of the second third of the vocal folds. In six different images a mark should be related to the particular third of the vocal folds. The phoniatricians were asked to assess how certain they were in their valuation. They were asked either, how long they have been working as a physician and how long they have been specialized as a phoniatrician and as an ENT-surgeon. In the follow up study the phoniatricians were requested to first divide up the thirds in a way that the dorsal third corresponds to the cartilaginous part of the vocal folds (scheme 1) and second divide up the thirds in a way that all three thirds correspond to the ligamental part of the vocal folds. DISCUSSION AND FINDINGS: In the pilot study, when no instructions for the division of the thirds were given, the data differed much more than in the follow up study, when the physicians were told to use scheme 1 and scheme 2. That was because some phoniatricians divided up just the ligamental part and others the ligamental plus the cartilaginous part of the vocal folds in thirds. The more the physicians could overlook the membraneous part of the vocal folds the more certain they were in their assessment. CONCLUSION: The assessment of the division of the vocal folds in thirds is more homogeneous when the phoniatricians were requested to divide up the thirds in a way that the dorsal third corresponds to the cartilaginous part of the vocal folds (scheme 1). Therefore we suggest that this way of division should be used further on.

Adult↗

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.

Animals↗

Hatchability, serology and virus excretion following in ovo vaccination of chickens with an avian metapneumovirus vaccine.

The present investigation describes for the first time the effect of an avian metapneumovirus vaccine administered in ovo to 18-day-old chicken embryos. The application of the vaccine had no adverse effect on the hatchability or the health of the chicks post hatch. The antibody titres achieved were higher than those determined for birds vaccinated at 1 day old. Not only were the mean titres in the in ovo vaccinated groups higher, but many more birds developed a measurable antibody response than birds vaccinated at 1 day old. Variation of the vaccine dose used in ovo had little effect on the serological responses that peaked 21 to 28 days post hatch. Re-isolation of the vaccine virus was much more successful from birds vaccinated in ovo than from birds vaccinated at 1 day old, and detection of the nucleic acid by polymerase chain reaction correlated with the results of live virus isolation.

Animals↗

[Diagnosis of psychogenic hearing disorders in childhood].

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.

Adolescent↗

[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.

Female↗

[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.

Adult↗

[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/.

Adult↗