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Biomedical subjects

R Hauser

Publications and source records attributed to R Hauser.

At least 127 records · Page 7Linked to original sources
PubMed1993

[Presbycusis].

Hearing loss in the elderly is the most common type of hearing impairment. The term presbyacusis has been used to describe this category of hearing loss when there are no other etiological factors. However, the term is not precise, because any of several locations along the auditory pathway may be involved to produce the symptoms. The diagnosis is based more on the course of the hearing loss and the associated biological signs of aging than on specific criteria. The loss of speech-understanding ability is one of the most important indicators for a therapeutic intervention, which generally aims at amplification using a personal hearing aid. An improvement in speech-understanding ability with a hearing aid depends on several complex factors, and there is a large amount of intersubject variability in the benefit derived from amplification, even when the magnitude of the hearing loss is comparable. The aim of research on presbyacusis over the next several years--keeping in mind the demographic development in the industrialized countries--will be to further the differential analysis of the factors contributing to auditory communication disorders in the aging population.

Aged↗
PubMed1992

Postpartum periarticular hip abscess with later coxitis caused by group B streptococcus.

Intrapartum haematogenous spread of vaginal group B Streptococcus is rare, but it can lead to severe complications like abscesses, endocarditis and meningitis postpartum. We report a postpartum periarticular hip abscess caused by group B Streptococcus. Clinically it caused pain in the hip and a compression of the femoral nerve with motor and sensory component. Diagnosis was made by aspiration under computed tomography control. The only sign of infection was an increased sedimentation rate. After antibiotic treatment the symptoms disappeared and the abscess vanished, but it was reactivated 4 months after delivery, leading to arthritis of the hip joint. Another antibiotic treatment was administered for 8 weeks. 17 months postpartum the patient is well, but a development of a secondary coxarthrosis can not be excluded.

Abscess↗
PubMed1992

The predictive fertilization value of the hypoosmotic swelling test (HOST) for fresh and cryopreserved sperm.

BACKGROUND: The hypoosmotic swelling test (HOST) was recommended as a predictive test for in vitro fertilization (IVF) outcome. These results, however, were controversial and the results for thawed semen were insufficient. The present study was conducted in order to clarify the predictive value of the HOST for IVF in fresh and thawed sperm. METHODS: The hypoosmotic swelling test was performed in three groups: husband's fresh semen "subfertile" group, donor's thawed semen group, and donor's fresh semen "fertile" group. RESULTS: No correlation was found between HOST values and sperm characteristics in fresh or thawed sperm. Fresh sperm HOST values correlated with IVF fertilizations. No such correlations were found when thawed sperm was used. HOST values were significantly higher in the fresh fertile donor group than in the fresh subfertile group (P less than 0.001). Following the freezing and thawing process, HOST values decreased dramatically. Nevertheless, the fertilization rate was still higher compared to that of the fresh subfertile group (P less than 0.001). There were significantly more IVF cycles with no fertilizations when HOST values were below 45%. CONCLUSION: The HOST has a predictive value for fertilization of oocytes in IVF cycles when fresh semen, but not thawed sperm, is used. The freezing-thawing process affects the outer membrane of the spermatozoon and changes its characteristics, leading to a decrease in HOST values. Sperm characteristics that play a role in the fertilization process are not expressed directly by HOST values.

Cell Membrane↗
PubMed1992

Eustachian tube function in sudden hearing loss and in healthy subjects.

The relationship between sudden hearing loss and an ipsilateral patulous tube was tested in our Eustachian tube laboratory. Fifty patients suffering from sudden hearing loss were examined by the pressure chamber impedance method, giving objective data on Eustachian tube function. Results were compared to those obtained from 56 healthy volunteers in a preceding investigation. Our investigation did not show any associations between patulous tube syndrome and sudden hearing loss, as had been claimed by several authors previously. There was even indication of a decreased patency of Eustachian tube in our patients in active and passive tubal tests. We could demonstrate a high reproducibility of values obtained by our method, indicating that results are representative in healthy persons as well as in patients. In a case report the importance of objective diagnostic methods in differential diagnostics of Eustachian tube pathology is emphasized.

Ear, Middle↗
PubMed1992

[The effect of systematic change in middle ear pressure on transitorily evoked otoacoustic emissions--a pressure chamber study].

Otoacoustic emission power spectrum and amplitude are influenced by the middle ear transmission mechanism. In this study, the influence of progressive increase in atmospheric pressure on the frequency and amplitude of transiently evoked otoacoustic emissions (TEOAEs) was determined in normally hearing humans. For testing, subjects were seated in a pressure chamber. Transiently evoked otoacoustic emissions were tested in 20 ears of 20 subjects using of 80 microseconds unfiltered click and tone bursts duration at 0.5, 1, 2, 3, and 4 kHz presented at 40 dBnHL. Ambient air pressure was increased from 0 kPa up to 8 kPa in 2-kPa steps. In spite of large interindividual differences, the results demonstrate that the changes that occur in TEOAEs with variations in ambient air pressure are frequency specific. Amplitude and reproducibility of high-frequency TEOAEs are less influenced by middle ear pressure changes than are the amplitude and reproducibility of low- and middle-frequency TEOAEs. Results have implications for clinical and research applications of TEOAE measurements in that middle-ear and inner-ear effects on OAEs can be differentiated.

Acoustic Stimulation↗
PubMed1992

Enhanced left ventricular diastolic filling associated with long-term endurance training.

Normal aging is associated with an impairment in early left ventricular diastolic filling. To test the hypothesis that long-term endurance exercise training is associated with enhanced ventricular diastolic filling indices, we compared transmitral pulsed Doppler inflow spectra in healthy young adults; healthy elderly, sedentary subjects (sedentary old); and healthy elderly, endurance athletes (master athletes). Our data demonstrate that, despite an increase in left ventricular mass, early diastolic filling was enhanced in master athletes compared to the sedentary old. Blood pressure of both master athletes and the sedentary olds was greater than the young adults, but the higher blood pressure did not correlate to changes in filling parameters. Resting systolic function and heart rate were not significantly different in all three different groups. Early left ventricular filling indices in master athletes more closely resemble transmitral inflow patterns of healthy young adults. Long-term endurance exercise is associated with physiologic hypertrophy and ventricular filling dynamics more characteristic of the young than the old.

Adult↗
PubMed1992

Migration sedimentation technique as a predictive test for the fertilizing capacity of spermatozoa in an in-vitro fertilization programme.

The migration-sedimentation technique (MST) has been proposed as a means of separating high quality motile spermatozoa. The present study was conducted in order to evaluate whether sperm performance following separation by MST predicts their fertilizing capacity in an in-vitro fertilization (IVF) programme. Ninety semen specimens were analysed for use in an IVF-embryo transfer (ET) programme. Each specimens was divided into two parts: one was processed in the IVF programme and was used after sperm swim-up separation for insemination of human ova. The other aliquot (0.2 ml) was separated by MST, and the sperm then characterized by their concentration, motility, degree of motility and morphology. Sperm characteristics after separation by MST were then correlated with the results of the IVF-fertilization rates. In 79 of 90 IVF-ET cycles, at least one oocyte was fertilized. All post-MST sperm characteristics were significantly higher in cycles with fertilizations compared to IVF cycles without fertilization. A larger percentage of the total motile spermatozoa were recovered after MST in semen specimens with fertilization, compared to semen specimens without fertilization (39.9 +/- 3.6 and 20.6 +/- 6.6%, respectively; P < 0.05). This value was correlated with the percentage of fertilized oocytes (r = 0.24; P < 0.02). More IVF cycles with fertilizations were recorded in cases in which the recovery of motile sperm was > 25% (P < 0.005), or when more than 1.5 x 10(6) motile spermatozoa were recovered after MST (P < 0.0001). As sperm characteristics after MST correlated significantly with their fertilizing capacity, the MST test could be used in evaluation of the fertilizing capacity of spermatozoa.

Cell Separation↗
PubMed1992

Alcoholism and the D2 receptor gene.

The allelic association of the human dopamine D2 receptor gene and alcoholism was evaluated in 20 male alcoholics and 20 controls (sex, race, and geographic place of birth matched). This study further examines the issue of alcoholism severity and A1 allele frequency. No difference in A1 allele frequency was observed between these two groups. Similarly, no relationship between alcoholism severity and A1 frequency within the alcoholics was demonstrated.

Adult↗
PubMed1992

Influence of general anesthesia on transiently evoked otoacoustic emissions in humans.

The influence of general anesthesia (GA) on transiently evoked otoacoustic emissions (TEOAEs) was studied in 19 normally hearing women undergoing surgery. Emissions were measured on the day before the operation, after premedication but before the beginning of the operation, and during and after the operation. There were no significant differences in TEOAE amplitude or in reproducibility between results obtained the day before the operation and after premedication. Ten patients received nitrous oxide (N2O) during GA (N2O group), and 9 patients did not (non-N2O group). The amplitude of TEOAEs was reduced during GA in 9 of 10 patients in the N2O group and in 7 of 9 patients in the non-N2O group. However, the average decrease of amplitude after the first 10 minutes was greater in the N2O group (4 +/- 3.4 dB) than in the non-N2O group (0.18 +/- 1.4 dB). The corresponding mean reproducibility of the response decreased in 9 of 10 patients of the N2O group (29% +/- 24%) and was nearly unchanged in the non-N2O group (2.3% +/- 7.2%). The time course of the amplitude reduction was similar in both groups. The smallest amplitudes were reached on an average by 19.3 +/- 11.4 minutes in the N2O group and by 17 +/- 13.6 minutes in the non-N2O group. Preoperative and postoperative TEOAEs were comparable in level and reproducibility. Differential frequency effects imply a middle ear effect for the greater reduction of TEOAE amplitudes in the N2O group due to gas diffusion into the middle ear.(ABSTRACT TRUNCATED AT 250 WORDS)

Acoustics↗
PubMed1991

[Reconstruction of large segmental defects of the lower extremities following resection of malignant and locally aggressive bone tumors].

The chances to be cured from a primary malignant musculoskeletal tumor have improved dramatically during the last two decades with the introduction of adjuvant chemotherapy. The cure rate e.g. for osteosarcomas and Ewing sarcomas has improved in this period from about 20% to 75%. Furthermore instead of amputations for local tumor control local resections have become possible in most cases when the rules of oncologic surgery for such tumors beginning with the biopsy are strictly followed. With the improved long term survival of patients afflicted by musculoskeletal malignancies the demands upon reconstructions after large resections have significantly increased. Techniques actually available for different localizations of tumors of the femur and tibia with trends for 'more biologic' procedures with arthrodeses and massive allografts are demonstrated besides new endoprosthetic material.

Adolescent↗
PubMed1991

A child with an unusually high-level spontaneous otoacoustic emission.

We describe a child who emitted a continuous audible sound from his left ear. A high-level spontaneous otoacoustic emission was measured at the frequency of 5.64 kHz with an amplitude of 55 dB sound pressure level. A high-frequency hearing loss was measured in both ears; however, it was more pronounced in the emitting ear. The emission failed to synchronize to external click stimuli. This spontaneous emission is probably related to a cochlear defect, but it should not contribute additionally to the child's existing auditory impairment.

Acoustics↗
PubMed1991

Click- and tone-burst-evoked otoacoustic emissions in normally hearing ears and in ears with high-frequency sensorineural hearing loss.

Otoacoustic emissions (OAEs) evoked by clicks and tone bursts (TBs) were measured using a minor modification of the 1987 Bray and Kemp system in normal and hearing-impaired ears with high-frequency sensorineural hearing loss. Sixty ears of 60 subjects were tested. The average behavioral hearing threshold of 20 normally hearing ears was measured for the different "nonlinear" stimulus groups and defined as 0 dBnHL. Emissions were recorded in another 20 normally hearing ears and in 20 ears with steep high-frequency sensorineural hearing loss above 2kHz. An unfiltered click of 80 microseconds duration and TBs at frequencies of 0.5, 1, 2, 3, 4, 5, and 6 kHz served as stimuli. The ears with high-frequency hearing loss were clearly distinguished from the normal ears in that emission energy decreased with higher frequency stimuli above 2 kHz. The mean slopes of the response-growth functions were significantly higher at lower audiometric thresholds. The normal ears showed a slope of 0.21-0.35 dB/dBnHL above 2 kHz while the slope of the pathological ears was 0.04-0.13 dB/dBnHL. These differences in TBOAEs could possibly be used clinically to carry out hearing tests that are more frequency-specific than those measuring solely click-evoked OAEs. Pathological ears had emissions in the lower frequency range, where they had a normal audiometric threshold. However, these emissions had significantly far lower amplitudes at frequencies around 0.5 and 1 kHz when compared to normal ears. This reduced emission energy may indicate a cochlear impairment of the pathological ears in frequency ranges where they still had normal audiometric thresholds.

Acoustic Stimulation↗
PubMed1991

Immunohistochemical investigations to demonstrate vital direct traumatic damage of skeletal muscle.

The muscle proteins actin, myosin, desmin and myoglobin were investigated in traumatically damaged human and animal skeletal muscle using an immunohistochemical PAP-method. A depletion of all the proteins investigated was observed in muscle fibres damaged in the antemortem period. The antigens could however also be demonstrated in the otherwise empty sarcolemma, the discoid disintegration zones of the fibres and between the fibres. The depletion begins immediately after the trauma and myoglobin is the first to be affected. No such changes could be observed after post mortem muscle damage. The antigens could be demonstrated until 72 hours post mortem. The demonstration of protein depletion is an important addition to the light microscopical findings in vital muscle alterations.

Actins↗
PubMed1991

[The clinical use of oto-acoustic emissions of cochlear distortion products].

Otoacoustic emissions of cochlear distortion products (DPOAEs) were measured in normally hearing and hearing-impaired human ears. A total of 133 subjects (231 ears) were tested. Two puretone stimuli f1 and f2 were delivered to a sound probe fixed in the outer ear canal. The frequencies of the two primaries were chosen so that their geometric mean represented pure-tone audiometric frequencies. The otoacoustic emission was measured at the distortion product frequency 2f1-f2 by spectral averaging. For 199 ears, the levels of the primaries were 73 dBHL for L1 and 67 dBHL for L2. Statistical analysis was carried out in 77 ears of 46 subjects with normal hearing (average hearing levels at pure-tone audiometric thresholds less than or equal to 10 dBHL) and 36 ears of 25 subjects exhibiting near-normal hearing (average hearing levels at pure-tone audiometric thresholds less than or equal to 20 dBHL). The mean DPOAE amplitudes were similar in these two groups of ears. In 111 of these 113 ears (98.2%), DPOAEs were detected at three or more of the six tested frequencies between 1 and 6 kHz. DPOAEs were measured in more than 75% of ears at each frequency between 1-6 kHz and in more than 86% between 1-4 kHz. Eighty-six hearing-impaired ears of 44 subjects with sensorineural hearing loss formed the patient group. A highly significant correlation between pure-tone audiometric thresholds and DPOAE amplitudes was demonstrated in the frequency range of 1-4 kHz. Percentiles of DPOAE amplitudes were calculated in 22 ears with a mean pure-tone threshold less than or equal to 5 dBHL and in 12 specially selected pathological ears.(ABSTRACT TRUNCATED AT 250 WORDS)

Acoustic Stimulation↗
PubMed1991

[Tube function in sudden hearing loss].

The function of the Eustachian tube was assessed in 50 patients suffering from sudden hearing loss, using the pressure chamber impedance method. We investigated the existence of a relationship between sudden hearing loss and the occurrence of a patulous tube. We could not observe more patulous tubes in patients with sudden hearing loss compared to a control group with healthy ears. We registered the parameters "tissue resistance pressure" and "tubal opening pressure", both characterising the passive qualities of the Eustachian tube. There was no indication of a facilitated passive tubal opening nor a tendency to a patulous tube among our patients. Statistical evaluation of these parameters showed no significantly different tubal function on comparing the right and the left ear, as well as the ear affected by sudden hearing loss and the healthy ear. We conclude that there is no relationship between sudden hearing loss and patulous tube.

Adolescent↗
PubMed1991

The influence of systematic primary-tone level variation L2-L1 on the acoustic distortion product emission 2f1-f2 in normal human ears.

The purpose of the present study was to determine the effect of primary-tone level variation, L2--L1, on the amplitude of distortion-product otoacoustic emissions (DPOAEs). The DPOAE at the frequency 2f1--f2 (f2 greater than f1) was measured in 20 ears of ten normally hearing subjects. Acoustic distortion products were generated by primaries f1 and f2 with geometric mean frequencies of 1, 2, and 4 kHz. The f2/f1 ratios were 1.25 (1 kHz), 1.23 (2 kHz), and 1.21 (4 kHz). The primary-tone level L1 was kept constant at either 65 or 75 dB SPL while the second primary-tone level L2 was varied between 20 and 90 dB SPL in 5-dB steps. The level differences L2--L1 generating maximal DPOAE amplitudes depended on L1 and on the geometric mean frequency of f1 and f2. There were large interindividual differences. Overall, the L2--L1 evoking maximal mean DPOAE amplitudes was --10 dB for geometric mean frequencies of 1 and 2 kHz with both L1 = 65 dB SPL and L1 = 75 dB SPL. For 4 kHz, L2-L1 was --5 dB with L1 = 65 dB SPL and 0 dB with L1 = 75 dB SPL. The mean slopes of the DPOAE growth functions in the initial linearly increasing portions were steeper at higher stimulus frequencies, increasing from 0.52 at 1 kHz to 0.72 at 4 kHz for L1 = 65 dB SPL and from 0.48 at 1 kHz to 0.72 at 4 kHz for L1 = 75 dB SPL.

Adult↗