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Biomedical subjects

T Spillmann

Publications and source records attributed to T Spillmann.

At least 19 recordsLinked to original sources
PubMed2002

Radioiodine treatment of feline hyperthyroidism in Germany.

AIM: Establishment of radioiodine treatment of feline hyperthyroidism in veterinary routine in accordance with German radiation protection regulations. PATIENTS AND METHODS: 35 cats with proven hyperthyroidism were treated with 131I in a special ward. Thyroid uptake and effective halflife were determined using gammacamera dosimetry. Patients were released when measured whole body activity was below the limit defined in the German "Strahlenschutzverordnung". RESULTS: 17/20 cats treated with 150 MBq radioiodine and 15/15 cats treated with 250 MBq had normal thyroid function after therapy, normal values for FT3 and FT4 were reached after two and normal TSH levels after three weeks. In 14 cats normal thyroid function was confirmed by controls 3-6 months later. Thyroidal iodine uptake was 24 +/- 10%, effective halflife 2.5 +/- 0.7 days. Whole body activity < 1 MBq was reached 13 +/- 4 days after application of 131I. Radiation exposure of cat owners was estimated as 1.97 microSv/MBq for adults. CONCLUSION: Radioiodine therapy of feline hyperthyroidism is highly effective and safe. It can easily be performed in accordance with German radiation protection regulations, although this requires hospitalisation for approximately two weeks. Practical considerations on radiation exposure of cat owners do not justify this long interval. Regulations for the veterinary use of radioactive substances similar to existing regulations for medical use in humans are highly desirable.

Adult↗
PubMed2001

Zoonotic potential of Enterocytozoon bieneusi.

The reservoirs and the modes of transmission of the most frequent microsporidial species in humans, Enterocytozoon bieneusi, are still unknown. We have examined fecal samples of 26 humans and 350 animals from 37 species to find 18 samples containing this parasite from humans, cats, pigs, cattle, and a llama. Genotypic characterization of the internal transcribed spacer of the rRNA gene resulted in 14 different genotypes, 6 of them previously undescribed. Phylogenetic analysis revealed the lack of a transmission barrier between E. bieneusi from humans and animals (cats, pigs, and cattle). Thus, E. bieneusi appears to be a zoonotic pathogen.

Animal Diseases↗
PubMed2001

An immunoassay for canine pancreatic elastase 1 as an indicator for exocrine pancreatic insufficiency in dogs.

The detection of pancreatic elastase 1 in stool samples has become the noninvasive gold standard for the diagnosis of pancreatic insufficiency in humans. Accordingly, the development of a sandwich-ELISA specific for canine pancreatic elastase 1, based on monoclonal antibodies, is presented here. The test has a detection range of 4-240 microg canine pancreatic elastase l/g feces. The intraassay coefficient of variation is 7.4%, and the interassay coefficient of variation is 7.7%. Spiking experiments show that canine elastase 1 is quantitatively detectable in fecal samples. Interestingly, the range of the elastase 1 concentration in canine feces within several days is higher as compared with humans. As the proposed cutoff of 10 microg/g is below this variation range in 96.1% of the tested samples, the effect on the test specificity is negligible. Because the test detects neither human nor bovine and porcine elastase 1, pancreatic function can be monitored without interrupting an enzyme replacement therapy.

Animals↗
PubMed2000

A novel locus (DFNA23) for prelingual autosomal dominant nonsyndromic hearing loss maps to 14q21-q22 in a Swiss German kindred.

DFNA23, a novel locus for autosomal dominant nonsyndromic hearing loss, was identified in a Swiss German kindred. DNA samples were obtained from 22 family members in three generations: 10 with hearing impairment caused by the DFNA23 locus, 8 unaffected offspring, and 4 spouses of hearing-impaired pedigree members. In this kindred, the hearing-impaired family members have prelingual bilateral symmetrical hearing loss. All audiograms from hearing-impaired individuals displayed sloping curves, with hearing ability ranging from normal hearing to mild hearing loss in low frequencies, normal hearing to profound hearing loss in mid frequencies, and moderate to profound hearing loss in high frequencies. A conductive component existed for 50% of the hearing-impaired family members. The majority of the hearing-impaired family members did not display progression of hearing loss. The DFNA23 locus maps to 14q21-q22. Linkage analysis was carried out under a fully penetrant autosomal dominant mode of inheritance with no phenocopies. A maximum multipoint LOD score of 5.1 occurred at Marker D14S290. The 3.0-LOD unit support interval is 9.4 cM and ranged from marker D14S980 to marker D14S1046.

Adult↗
PubMed2000

A novel locus (DFNA24) for prelingual nonprogressive autosomal dominant nonsyndromic hearing loss maps to 4q35-qter in a large Swiss German kindred.

Nonsyndromic hearing loss is one of the most genetically heterogeneous traits known. A total of 30 autosomal dominant nonsyndromic hearing-loss loci have been mapped, and 11 genes have been isolated. In the majority of cases, autosomal dominant nonsyndromic hearing loss is postlingual and progressive, with the exception of hearing impairment in families in which the impairment is linked to DFNA3, DFNA8/12, and DFNA24, the novel locus described in this report. DFNA24 was identified in a large Swiss German kindred with a history of autosomal dominant hearing loss that dates back to the middle of the 19th century. The hearing-impaired individuals in this kindred have prelingual, nonprogressive, bilateral sensorineural hearing loss affecting mainly mid and high frequencies. The DFNA24 locus maps to 4q35-qter. A maximum multipoint LOD score of 11.6 was obtained at 208.1 cM at marker D4S1652. The 3.0-unit support interval for the map position of this locus ranges from 205.8 cM to 211.7 cM (5.9 cM).

Child, Preschool↗
PubMed2000

Serum feline trypsin-like immunoreactivity following administration of ceruletide to healthy cats.

OBJECTIVE: To determine changes in serum feline trypsin-like immunoreactivity (fTLI) in response to administration of ceruletide to healthy cats. ANIMALS: 11 healthy cats. PROCEDURES: Serum fTLI was determined, using a radioimmunoassay, before and 10, 20, 30, 40, and 50 minutes after IM administration of ceruletide (0.3 mg/kg [0.14 mg/lb]). RESULTS: Mean +/- SD baseline serum fTLI was 23.1 +/- 4.1 mg/L. There was a statistically significant, but clinically unimportant, increase in serum fTLI 10 and 30 minutes after ceruletide administration. CONCLUSIONS AND CLINICAL RELEVANCE: In healthy cats, administration of ceruletide induced a statistically significant, but clinically unimportant, increase in serum fTLI. Whether responses in cats with exocrine pancreatic disorders would be different is unknown, but results suggest that a ceruletide stimulation test would likely not be useful for differentiating between healthy cats and cats with subclinical chronic exocrine pancreatic disorders.

Animals↗
PubMed1998

[Determination and clinical relevance of fecal pancreatic elastase in dogs].

The determination of faecal pancreatic elastase 1 is a reliable test for the diagnosis of chronic pancreatic diseases in man due to its high sensitivity and specificity (93%). A clinical study was performed to investigate the detectability of canine faecal pancreatic elastase with polyclonal anti human pancreatic elastase 1 antibodies in 52 dogs with chronic diarrhoea and weight loss. To assess the diagnostic value of this parameter for the diagnosis of exocrine pancreatic insufficiency (EPI) in dogs faecal chymotrypsin activity was determined and serum trypsin-like immunoreactivity (TLI) concentration was measured within the Ceruletid test in all patients. The study revealed that canine faecal pancreatic elastase cross reacts with polyclonal anti human pancreatic elastase 1 antibodies. In comparison with the results of the other pancreas tests it was proved that the concentration of canine faecal pancreatic elastase determined by rocket immunoelectrophoresis is highly sensitive for EPI in dogs (sensitivity 100%) but there are species differences in specificity between man and dog (specificity 56.5%).

Animals↗
PubMed1994

Genetic diseases of hearing.

The study of genetic hearing loss has always been hindered by the difficulty of separating sporadic genetic cases from cases affected by environmental influences. This is because audiologic methods are largely insensitive to causes, and the anatomical location of the affected structures in the middle and inner ear makes histopathologic verifications difficult. With recent progress in genetic investigation, eg, the mapping of the gene location for the Waardenburg and Usher syndromes, both syndromic and nonsyndromic genotypes have been elucidated in humans and in animal models. In the future, molecular genetics will play an increasingly important role in the genetic counseling of suspected carriers, as well as in the prevention of additional hearing loss from exogenic causes (noise, ototoxic drugs) in confirmed cases of genetically vulnerable ears.

Animals↗
PubMed1993

Speech encoding strategies for multielectrode cochlear implants: a digital signal processor approach.

The following processing strategies have been implemented on an experimental laboratory system of a cochlear implant digital speech processor (CIDSP) for the Nucleus 22-channel cochlear prosthesis. The first approach (PES, Pitch Excited Sampler) is based on the maximum peak channel vocoder concept whereby the time-varying spectral energy of a number of frequency bands is transformed into electrical stimulation parameters for up to 22 electrodes. The pulse rate at any electrode is controlled by the voice pitch of the input speech signal. The second approach (CIS, Continuous Interleaved Sampler) uses a stimulation pulse rate which is independent of the input signal. The algorithm continuously scans all specified frequency bands (typically between four and 22) and samples their energy levels. As only one electrode can be stimulated at any instance of time, the maximally achievable rate of stimulation is limited by the required stimulus pulse widths (determined individually for each subject) and some additional constraints and parameters. A number of variations of the CIS approach have, therefore, been implemented which either maximize the number of quasi-simultaneous stimulation channels or the pulse rate on a reduced number of electrodes. Evaluation experiments with five experienced cochlear implant users showed significantly better performance in consonant identification tests with the new processing strategies than with the subjects' own wearable speech processors; improvements in vowel identification tasks were rarely observed. Modifications of the basic PES- and CIS strategies resulted in large variations of identification scores. Information transmission analysis of confusion matrices revealed a rather complex pattern across conditions and speech features. Optimization and fine-tuning of processing parameters for these coding strategies will require more data both from speech identification and discrimination evaluations and from psychophysical experiments.

Acoustic Stimulation↗
PubMed1993

Speech discrimination via cochlear implants with two different digital speech processing strategies: preliminary results for 7 patients.

The following processing strategies have been implemented on an experimental laboratory system of a cochlear implant digital speech processor (CIDSP) for the Nucleus 22-channel cochlear prosthesis. The first approach (PES, Pitch Excited Sampler) is based on the classical channel vocoder concept whereby the time-averaged spectral energy of a number of logarithmically spaced frequency bands is transformed into appropriate electrical stimulation parameters for up to 22 electrodes. The pulse rate at any electrode is controlled by the voice pitch of the input speech signal. The pitch extraction algorithm calculates the autocorrelation function of a lowpass-filtered segment of the speech signal and searches for a peak within a specified time window. A random pulse rate of about 150 to 250 Hz is used for unvoiced speech portions. The second approach (CIS, Continuous Interleaved Sampler) uses a stimulation pulse rate which is independent of the input signal. The algorithm scans continuously all specified frequency bands (typically between 4 and 22) and samples their energy levels. Evaluation experiments with 7 experienced cochlear implant users showed significantly better performance in consonant identification tests with the new processing strategies than with the subjects' own wearable speech processors whereas improvements in vowel identification tasks were rarely observed. Modifications of the basic PES- and CIS-strategies resulted in large variations of identification scores. Information transmission analysis of confusion matrices revealed a rather complex pattern across conditions and speech features. No final conclusions can yet be drawn. Optimization and fine-tuning of processing parameters for these coding strategies require more data both from speech identification and discrimination as well as psychophysical experiments.

Acoustic Stimulation↗
PubMed1993

[Hearing aid rehabilitation of hearing disorders in adults].

Hearing-aid provision is still partly a medical task, in spite of technological progress and a confusing variety of types and models of devices. The diagnosis of the underlying disease, the appreciation of the consequences of hearing loss and the counseling of the hearing impaired person are prerequisites of the treatment. The physician should try to determine the etiology of the hearing loss. Also, a state-of-the-art otologic examination should be performed and the physician should be sensitive to the psychological and social consequences of the patient's hearing loss. For the assessment of fitted hearing aids, basic knowledge of the technical background is required. To measure hearing-aid benefit in the ENT office, suprathreshold and speech audiometry are indispensable tools.

Adult↗
PubMed1992

Digital speech processing for cochlear implants.

A rather general basic working hypothesis for cochlear implant research might be formulated as follows. Signal processing for cochlear implants should carefully select a subset of the total information contained in the sound signal and transform these elements into those physical stimulation parameters which can generate distinctive perceptions for the listener. Several new digital processing strategies have thus been implemented on a laboratory cochlear implant speech processor for the Nucleus 22-electrode system. One of the approaches (PES, pitch excited sampler) is based on the maximum peak channel vocoder concept whereby the spectral energy of a number of frequency bands is transformed into appropriate electrical stimulation parameters for up to 22 electrodes using a voice pitch synchronous pulse rate at any electrode. Another approach (CIS, continuous interleaved sampler) uses a maximally high pitch-independent stimulation pulse rate on a selected number of electrodes. As only one electrode can be stimulated at any instance of time, the rate of stimulation is limited by the required stimulus pulse widths (as determined individually for each subject) and some additional constraints and parameters which have to be optimized and fine tuned by psychophysical measurements. Evaluation experiments with 5 cochlear implant users resulted in significantly improved performance in consonant identification tests with the new processing strategies as compared with the subjects own wearable speech processors whereas improvements in vowel identification tasks were rarely observed. The pitch-synchronous coding (PES) resulted in worse performance compared to the coding without explicit pitch extraction (CIS).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Comparison of hearing aids and cochlear implants in profoundly and totally deaf persons.

Cochlear implants are increasingly used in the rehabilitation of the profoundly and totally deaf. Usually, insufficient gain of speech discrimination with a powerful conventional hearing aid is considered as a prerequisite for a cochlear prosthesis. With recent improvements of electronic systems, the criterion for this decision may change. To keep pace with the technical progress, a battery of speech sound tests suited for minimal auditory capabilities (MAC-battery) was developed and applied to groups of patients fitted with conventional instruments and with two different types of cochlear implants. Based on the comparison of the MAC-battery results of hearing aid groups, with the average performance of an implanted group, most conventionally fitted regular users of hearing aids should not be considered as candidates for cochlear implantation. The MAC-battery, although not a strictly standardized procedure, is a useful instrument for patient counselling and for the selection of implant candidates.

Adolescent↗
PubMed1989

Hereditary distal muscular atrophy with vocal cord paralysis and sensorineural hearing loss: a dominant form of spinal muscular atrophy?

In 1980 Young and Harper described a family with an unusual form of distal spinal muscular atrophy associated with vocal cord paralysis. We report a family with three similarly affected subjects. Progressive sensorineural hearing loss was an additional feature in our patients. Electrophysiological and histological investigations did not exclude an involvement of sensory neurones. Whether the classification of this dominant disorder with the spinal muscular atrophies is justified will depend on additional studies in further families.

Acoustic Impedance Tests↗
PubMed1989

Comparison of single-channel extracochlear and multichannel intracochlear electrodes in the same patient.

A postlingually deaf patient who had been using a single-channel extracochlear implant for 5 years was reimplanted in the same ear with a 22-channel intracochlear device after electrical failure of the internal receiver. In the subsequent follow-up period, auditory performance was investigated in a series of tests with nonspeech and speech material. Two weeks after processor fitting most test scores were equal or better with the new implant. Three months later, with only minimal training, the patient's performance in sentence, numerals and vowel tests was markedly improved. Analysis of vowel confusion matrices indicated a high percentage of F2 information perceived (53% compared with 5% with the single-channel device) and somewhat less F1 information (35% compared with 4% using the single-channel device). Further improvements of speech discrimination (especially consonant recognition) are conceivable if the fine temporal resolution provided by some single-channel devices can be combined with the spectral resolution of multichannel systems.

Cochlear Implants↗
PubMed1988

[Perception of acoustic speech features with single channel cochlear implants and hearing aids. A comparative analysis].

A newly developed battery of 12 multiple-choice tests for the German language (graded according to difficulty) comprising identification of sentences, words and syllables was applied to 8 patients with single-channel cochlear implants and to 35 deaf hearing-aid users. Phoneme confusion matrices were analysed using sequential information transmission analysis (SINFA) and multi-dimensional scaling (SINDSCAL). Acoustic parameters of the digitally stored test items were compared with the outcome of SINFA and SINDSCAL. It was found that cochlear implant and hearing-aid users relied on the same perceptual dimensions which were correlated to acoustic signal properties of the speech sounds. Best perceived acoustic features were time and amplitude structure of the speech sound (envelope). Fundamental and first formant frequency are evaluated both by implant and hearing-aid users. The use of higher frequency spectral information depends on the amount of residual hearing.

Auditory Threshold↗
PubMed1986

Stapedius reflex in multiple sclerosis.

The stapedius reflex (StR) was studied in humans by impedance audiometry. Ipsilateral and contralateral reflexes, obtained from 48 multiple sclerosis (MS) patients and 26 controls, were analysed. MS patients showed smaller reflex amplitudes, longer onset latencies and higher contralateral reflex thresholds. Using onset latencies, 33% of all MS patients had at least two abnormal ipsi- and/or contralateral StRs. If the diagnosis was MS of the definite type, this figure was 39%. The StR is therefore a useful tool for detecting a subclinical lesion in the brainstem and can contribute to the early diagnosis of MS.

Acoustic Impedance Tests↗