Biomedical subjects

C Völter

Publications and source records attributed to C Völter.

10 recordsLinked to original sources

PubMed2005

[Malignant paranasal sinus tumors. Diagnosis, therapy and results].

BACKGROUND: Malignant neoplasmas of the paranasal sinuses are rare and present usually in advanced tumor stage due to the lack of early clinical symptoms. PATIENTS AND METHODS: In the last 10 years, 63 patients with paranasal malignancies were treated at the Department of Otolaryngology, Head and Neck Surgery of the University of Würzburg. 33% of the patients showed an occupational exposition (wood-processing or metal industry). At the time of the first visit to our institution 95% of the patients presented with an extensive disease, staged T3 and T4. Adenocarcinoma (24%), squamous cell carcinoma (22%) and malignant melanoma (19%) were the most common histologies. Surgery combined with radiotherapy was the treatment strategy in 55 patients (87%). RESULTS: Patients with a complete surgical resection showed a higher 5-year-survival rate (77%) than patients with an incomplete resection (56%). In 38% (n=21) of the patients treated with surgery and radiotherapy, a local recurrence of the tumor was observed. This recurrence localised in the skull base and/or the orbita/periorbita occurred most frequently in the first (46%) or the second year (31%). CONCLUSION: The prognosis of malignant paranasal tumors depends mainly on the control of the local tumor growth. Modern strategies of surgical treatment in combination with radiotherapy need to be implemented in an effort to achieve a continuous remission.

Adenocarcinoma↗

PubMed2005

[Development of a new test for speech audiometry in children and results in CI children].

BACKGROUND: Speech audiometry plays an important role for hearing evaluation in children. Hearing impaired children, such as those with cochlear implant (CI) who frequently undergo testing, learn the test words by heart. Furthermore, the standard tests use words of former time. PATIENTS AND METHODS: Using the most frequently words of modern children's literature a speech assessment test was developed for children between 1 to 8 years. The material was first evaluated on normal hearing children. In a second step the phoneme and word perception scores of 35 CI children were measured using 60 - 100 dB SPL according to the most comfortable level (MCL) in free sound field. RESULTS: The performance-intensity function for the single words were highly comparable with those of the Freiburger or Göttinger speech perception test. The average speech reception threshold in CI children was 44 % (test I), 36 % (test II), 63 % (test III) and 69 % (test IV), respectively. Compared to the Mainzer and Göttinger speech perception test the new words were more difficult to understand than those of the known tests. However, a statistically significant difference could be noted only for test II. CONCLUSIONS: The new developed "Würzburger speech perception test" appears to be a useful additional tool for the evaluation of hearing impaired children in addition to the standard test procedures.

Audiometry, Speech↗

PubMed2003

Frequent detection of Mycoplasma pneumoniae in Bell's palsy.

The cause of Bell's palsy (BP) remains unknown despite various hints to an infectious etiology. Mycoplasma pneumoniae is a common pathogen of the respiratory tract causing pharyngitis, tracheobronchitis or pneumonia. Neurological complications are the most frequent extrapulmonary manifestation. So far, only a few case reports suggested an association between cranial nerve palsy and M. pneumoniae infection. Patients with a BP who were admitted to the Department of Otorhinolaryngology or Neurology of the University of Wuerzburg between 2000 and 2002 were tested serologically for the presence of antibodies against Borrelia burgdorferi, herpes viruses (HSV-1/2, VZV) and M. pneumoniae. The diagnosis of mycoplasmal infection was made when at least one of the following criteria was met: a threefold rise or more in the titer of antibody of M. pneumoniae in paired sample or a microparticle agglutination assay (MAG) of > or =1:40 and the detection of IgA and/or IgM antibodies in the acute phase serum. Ninety-one consecutive patients could be included. Fifteen patients showed a reactivation of a VZV ( n=12) or of a HSV-1 ( n=3) infection. In six cases the immunoblot revealed specific antibody bands for B. burgdorferi. In 24 patients (26.4%) a seroconversion of M. pneumoniae could be detected. Only two patients complained of mild respiratory symptoms. According to our results, M. pneumoniae is frequently associated with Bell's palsy. Thus, a routine screening for this pathogen, even in the absence of respiratory symptoms, is necessary.

Adolescent↗

PubMed2001

[Detection of loudness recruitment in patients with retrocochlear lesions using the "Würzburger Hörfeld" loudness scaling].

BACKGROUND: The pathogenesis of hearing loss caused by cerebellopontine angle tumors such as acoustic neuromas is unknown. The lack of loudness recruitment is thought to be one of the features of retrocochlear hearing impairment. In contrast to conventional suprathreshold tests, the categorial loudness scaling using the "Würzburger Hörfeld" is a valuable tool to describe the individual perception of sound. The aim of the present study was to analyze the loudness growth rate in patients with acoustic neuroma. PATIENTS AND METHOD: Pure tone and speech audiometry as well as auditory brainstem response and bilateral categorial loudness scaling were performed preoperatively in 54 patients with acoustic neuroma. Loudness scaling was done in free field switching off the contralateral ear by using an ear-plug. RESULTS: An abnormal rapid loudness growth function was found in 38 of the 54 patients (70.4%) at least at one frequency on the tumor side. The contralateral side was effected only in 57.4% of the patients. The incidence of a recruitment depended on the frequency with a maximum at 4 kHz. The slope of the loudness function showed a tendency to increase with increasing hearing loss. CONCLUSIONS: Loudness recruitment is not a rare phenomenon in patients with acoustic neuroma. The underlying cause (a preexisting hair cell damage, hair cell changes resulting from an obstruction of the cochlear blood supply or a disruption of the cochlear efferents) still remains unclear.

Adult↗

PubMed2001

[Diagnosis, treatment and results of malignant skull base tumours].

BACKGROUND: Malignant tumours of the cranial base are rare and present usually in advanced tumour stage due to the lack of early clinical symptoms. PATIENTS AND METHODS: Sixty patients with malignant tumours infiltrating the skull base were treated at the Department of Otorhinolaryngology Head and Neck Surgery, University of Würzburg between 1987 and 1999. Most of the tumours (n = 51) originated from the nose or paranasal sinuses, the epipharynx, the outer ear canal or the middle ear. Seven tumours were malignant brain tumours infiltrating the bony structures of the skull base or originated from the cranial base itself. Two patients suffered from metastases of an adenocarcinoma of the prostata. The histological diagnosis was confirmed in 53 patients preoperatively and in seven patients during tumour resection. Squamous cell carcinoma (n = 24), adenocarcinoma (n = 10) and sarcoma (n = 7) were the most common histologies found. RESULTS: A radical en bloc resection of the tumour was only possible in 26 out of 60 cases. A surgical tumour reduction with postoperative radiation therapy was performed in seven patients as a palliative approach. Eight patients underwent a combined radio- and chemotherapy according to the histological diagnosis. Primary radiotherapy was the treatment of choice in eleven patients, where the tumours were located in the central area of the cranial base. Palliative radiotherapy or solely medical pain control were applied to eight patients who presented either with distant metastases or an advanced tumour growth. The mean postoperative survival following radical surgery was 48 months and after primary radiotherapy 27 months. DISCUSSION: A statistical analysis of the results is not applicable due to the great variety of the disease concerning the histological diagnosis, the tumour size and the location as well as the small number of patients.

Adenocarcinoma↗

PubMed2000

[Effect of fibroblast growth factor-1 (FGF-1) on spiral ganglion cells of the mammalian cochlea].

Transient expression by hair cells, increasing levels of FGF-1 mRNA in neonatal rat spiral ganglion neurons and strong expression in adulthood, make FGF-1 a candidate to be associated with development and maintenance of the mammalian spiral ganglion. To test this hypothesis, dissociated spiral ganglion cells from 5 day old rats were cultured in the presence of FGF-1 at 100 ng/ml plus heparan sulfate proteoglycans (HSPG) at 500 ng/ml for 72 hours. Spiral ganglion cells incubated with FGF-1/HSPG achieved an average neurite length of 323 microns while control cells gained an average neurite length of 203 microns. The results of this study are consistent with our previous findings in whole spiral ganglion explants (3) where FGF-1 incubation significantly stimulated neurite outgrowth at about the same range. However, stimulation of neurite outgrowth in dissociated spiral ganglion cells suggests that FGF-1 directly binds to FGF receptors on the surface of spiral ganglion neurons and/or neurites instead of acting via intermediate cells such as glia. Since FGF receptor mRNA was found to be expressed only at very low levels in neonatal spiral ganglion neurons (7) it is possible that the receptors are highly localized, perhaps to neurite growth cones. Alternatively, an unknown FGF receptor or splice variant may be expressed in these cells. Adequate FGF-1 application to the human inner ear may stimulate spiral ganglion cell survival and neurite extension after hair cell loss in patients suitable for cochlear implant treatment. By creating a closer contact between spiral ganglion cells and the electrode, FGF-1 might also improve the efficacy of cochlear implants.

Animals↗

PubMed2000

[Inner ear depression after middle ear interventions].

BACKGROUND: Any type of otosurgical procedure involves the risk of inner ear damage. As middle ear surgery is also performed for functional reasons this risk should be taken into consideration. The aim of this study was to analyse the frequency and the nature of sensorineural hearing loss following chronic ear surgery. PATIENTS: A total of 3989 middle ear cases operated on between 1991 and February 1999 at the Department of Otorhinolaryngology, Head and Neck Surgery, University of Würzburg, Germany were studied retrospectively: 781 type I tympanoplasties, 2408 type III tympanoplasties and 800 cases of stapes surgery. The pre- and the postoperative audiograms in the frequency range between 500 and 8000 Hz were analysed and correlated to the different intraoperative findings. RESULTS: Sensorineural hearing loss occurred in a total of 1.3% of 2224 patients with normal preoperative bone conduction thresholds: 0.2% became deaf, 0.8% acquired a high tone loss at 4 kHz and in 0.3% patients also 2 kHz was affected. None of the documented intraoperative complications such as bleeding, unexpected opening of a semicircular canal, extensive manipulation at the ossicular chain or a gusher phenoma showed a relevant effect on postoperative bone conduction thresholds. The incidence of high tone loss was not increased in cases of extensive drilling of the temporal bone. An unexpected opening of the vestibulum led to a small, but statistically significant change in postoperative bone conduction thresholds. CONCLUSIONS: Our results demonstrated that the risk for sensorineural hearing loss caused by middle ear surgery is low. None of the analysed factors seems to be a relevant prognostic risk factor for postoperative inner ear depression.

Adolescent↗

PubMed1998

A broad spectrum PCR method for the detection of polyomaviruses and avoidance of contamination by cloning vectors.

Polyomaviruses induce tumours of different histological types when inoculated into experimental animals, but their aetiological role in the development of malignant tumours in humans remains questionable. We developed a degenerate PCR assay in an attempt to identify additional, presently unknown human polyomavirus types which may be involved in the malignant transformation of human tissues. Degenerate oligonucleotide primers were deduced from four different conserved amino acid motifs in the highly conserved viral capsid protein, VP1. Three different sets of primers were included for the each test. Bladder carcinomas, Hodgkin's lymphomas, meningiomas, Kaposi-tumours and -cell lines were analysed. No polyomavirus DNA sequences could be detected. A comparative analysis led to the recognition of the presence of SV40 DNA sequences in more than 200 vectors available in the EMBL and Genbank Databanks and commonly used in laboratories worldwide. The majority of primers used to detect polyomavirus sequences in human tumours are distributed throughout these regions also present in the vectors. Only a small stretch of 286bp in the overlapping region of the VP1, VP2 and VP3 genes is not present in the vector sequences. We propose to use this region for the design of additional non-contamination primers.

Cloning, Molecular↗

PubMed1997

Screening human tumor samples with a broad-spectrum polymerase chain reaction method for the detection of polyomaviruses.

Polyomaviruses induce tumors of different histological types when inoculated into experimental animals. An etiological role for this virus group in the development of malignant tumors in humans remains questionable, despite several reports demonstrating the presence of SV40, JCV, and BKV DNA in human cancers. Only two human polyomavirus types are known to date: JCV, causing progressive multifocal leukoencephalopathy (PML) under severe immunosuppression, and BKV, first isolated from the urine of a renal transplant recipient and associated with hemorrhagic cystitis. We developed a degenerate polymerase chain reaction assay in an attempt to identify additional, presently unknown human polyomavirus types that may be involved in the malignant transformation of human tissues. A large part of the gene coding for the viral capsid protein VP1 is highly conserved in nine polyomavirus types (and their strains) and was therefore selected as most suitable for the primer design. Degenerate oligonucleotide primers were deduced from four different conserved amino acid motifs in this region. Three different sets of primers were included in each test to obtain the highest sensitivity in combination with primers with the lowest degeneracy numbers. The sensitivity obtained ranged from 1 copy/cell for bovine polyomavirus to 100 copies/cell for LPV after ethidium bromide staining and was increased at least 10-fold after hybridization with a radiolabeled probe. A subsequent seminested amplification allowed for the detection of 1 copy/cell for LPV. These degenerate primers were applied to analyze bladder carcinomas, Hodgkin lymphomas, meningiomas, Kaposi tumors, and Kaposi-derived cell lines. No polyomavirus DNA sequences could be detected.

Animals↗

PubMed1996

Novel HPV types present in oral papillomatous lesions from patients with HIV infection.

Patients infected with the human immunodeficiency virus (HIV) often develop multiple papillomatous lesions of the oral cavity. In the present study, a total of 67 biopsies from benign oral lesions were analyzed for the presence of human papillomavirus (HPV) DNA using Southern-blot hybridization in combination with a polymerase chain reaction designed to detect all known HPV types, as well as unidentified types. These samples, collected at random from a high-risk population, were subsequently divided into 57 biopsies originating from patients with confirmed HIV infection and 10 biopsies from patients with unknown HIV status. Each sample was amplified with 7 different combinations of degenerate primers. All amplified products were sequenced. HPV DNA sequences were detected in 67% (45/67) of the samples. HPV 7 (19%) and HPV 32 (28%) were the predominant HPV types. HPV 32 was present in 2/4 fibromas tested. Two new HPV types, HPV 72 and HPV 73, were identified in oral warts with atypia. The complete genomes of these viruses were cloned and sequenced. Other HPV types detected were HPV 2a, HPV 6b, HPV 13, HPV 16, HPV 18, HPV 55, HPV 59 and HPV 69.

Base Sequence↗