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Biomedical subjects

C B Pedersen

Publications and source records attributed to C B Pedersen.

At least 19 recordsLinked to original sources
PubMed2000

[Meniere's disease. The clinical effect of gentamicin treatment].

In patients with Menière's disease attacks of vertigo can be invalidating. We have tested the effect of instillation of gentamycin in the middle ear to minimize or stop the attacks of vertigo. The results of a prospective investigation of 14 patients with Menière's disease treated with gentamycin in the period from 1993 to 1996 are presented. The patients were followed up to 53 months after the treatment and a telephone follow-up was performed. At the last follow-up nine out of 12 patients were free of attacks of vertigo. Two improved and one patient was unchanged. In two patients deafness developed in the treated ear, in the other patients the hearing was unchanged measured by speech reception threshold and discrimination loss. It is concluded that treatment of patients with Menière's disease by instillation of gentamycin into the middle ear does have a therapeutic effect. The treatment is simple and the effect of treatment is equal to other types of treatments. The risk of deafness in the treated ears stresses the importance of giving the patient sufficient information before treatment.

Administration, Topical↗
PubMed2000

Pseudoaneurysm of a lateral internal carotid artery in the middle ear.

We report a case where a 7-year-old girl suffered significant aural bleeding following myringotomy of the tympanic membrane. Investigations by computed tomography scan, carotid angiography, and magnetic resonance angiography showed a lateral aberrant internal carotid artery (LACI) with a little pseudoaneurysm in the middle ear. The anomaly of the internal carotid artery was supposed to be congenital, and the pseudoaneurysm was supposed to be traumatic, formed after incision into the wall of the artery. Considerations about diagnosis, symptoms, and treatment are discussed. The patient was treated by balloon embolization in the internal carotid artery without sequelae.

Aneurysm, False↗
PubMed2000

Functional brain imaging of tinnitus-like perception induced by aversive auditory stimuli.

Tinnitus is an aversive auditory percept of unknown origin. We tested the speculation that tinnitus may share neuronal processing mechanisms with aversive auditory percepts of known origin. This study revealed the functional neuroanatomy of the perception of aversive auditory stimuli. The stimuli were presented to 12 healthy volunteers so as to mimic the psychoacoustical features of tinnitus and its affective response in tinnitus sufferers. The regional cerebral blood flow distribution was measured by PET during four auditory processing conditions and one control condition. The aversive auditory stimuli activated primary and secondary auditory areas bilaterally, dorsolateral prefrontal attention areas, and structures in the limbic system which subserve emotional processing. Based on these results and findings from other functional neuroimages of tinnitus, we hypothesize that the perception of tinnitus may involve the functional linkage of these brain areas: secondary auditory cortex, dorsolateral prefrontal cortex, and limbic system.

Acoustic Stimulation↗
PubMed2000

Effects of blueberry and cranberry juice consumption on the plasma antioxidant capacity of healthy female volunteers.

OBJECTIVE: To assess whether consumption of 500 ml of blueberry juice or cranberry juice by healthy female subjects increased plasma phenolic content and antioxidant capacity. DESIGN: Latin square arrangement to eliminate ordering effects. After an overnight fast, nine volunteers consumed 500 ml of blueberry juice, cranberry juice or a sucrose solution (control); each volunteer participated on three occasions one week apart, consuming one of the beverages each time. Blood samples were obtained by venipuncture at intervals up to four hours after consumption of the juices. Urine samples were also obtained four hours after consuming the juice. RESULTS: Consumption of cranberry juice resulted in a significant increase in the ability of plasma to reduce potassium nitrosodisulphonate and Fe(III)-2,4, 6-Tri(2-pyridyl)-s-triazine, these measures of antioxidant capacity attaining a maximum after 60-120 min. This corresponded to a 30% increase in vitamin C and a small but significant increase in total phenols in plasma. Consumption of blueberry juice had no such effects. CONCLUSION: The increase in plasma antioxidant capacity following consumption of cranberry juice could mainly be accounted for by an increase in vitamin C rather than phenolics. This also accounted for the lack of an effect of the phenolic-rich but vitamin C-low blueberry juice. SPONSORSHIP: Funded by the Scottish Executive Rural Affairs Department and the Danish Government.

Adult↗
PubMed2000

Incidence and growth pattern of vestibular schwannomas in a Danish county, 1977-98.

During a period of 21 years 162 acoustic neuromas or vestibular schwannomas (VS) were diagnosed in the county of Aarhus. During this period the incidence increased gradually, probably due to improvement of the quality of computed tomography imaging (CTI), and more widely available access to magnetic resonance imaging (MRI). Sixty-four patients were followed up by repeated CTI or MRI, whereas the remaining patients were referred for immediate operation. Six of the observed patients had their tumours removed after demonstration of continuous tumour growth. The observation of 64 tumours over periods between 5 months and 15 years provided useful information on the natural history of sporadic VS. Our results showed that 14 VS (22%) regressed, 35 VS (55%) did not grow or had only minimal growth (growth rate up to 1 mm/year), whereas 15 VS (23%) grew > 1 mm/year. All VS with positive growth had regular growth patterns.

Adult↗
PubMed2000

Middle ear epithelium has inflammatory capacity.

Endotoxin, tumour necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta) and intercellular adhesion molecule-1 (ICAM-1) were detected in 88%, 51%, 58% and 66% of 152 middle ears from patients suffering from otitis media with effusion. In this study the hypothesis that bacterial endotoxin, TNF-alpha, IL-1 beta and ICAM-1 induce the inflammatory process characteristic of otitis media with effusion was tested. Cultures of rabbit middle ear epithelium were exposed to endotoxin, TNF-alpha or IL-1 beta. The expression of ICAM-1 on the cell surfaces was measured with a direct enzyme-linked immunosorbent assay on the cell layer. For TNF-alpha, 5 ng/ml significantly increased ICAM-1 expression, whereas 100 ng/ml had a toxic effect. For IL-1 beta, as little as 1 ng/ml produced a significant increase in ICAM-1 expression. Endotoxin stimulated ICAM-1 expression less strongly in concentrations from 100 ng/ml to 100 micrograms/ml. The findings indicate that stimulation of ICAM-1 by endotoxin is mediated, at least in part, by TNF-alpha and IL-1 beta. It is concluded that endotoxin induces sustained inflammation in OME, and that this inflammation is mediated, at least in part, by the primary cytokines TNF-alpha and IL-1 beta.

Animals↗
PubMed2000

Acute mastoidectomy in a Danish county from 1977 to 1997--operative findings and long-term results.

Data from patients undergoing acute mastoidectomy were examined retrospectively to evaluate if the nature of acute mastoiditis (AM) treated surgically has changed during the last 20 years (1977-97). Moreover, a prevalence study was conducted to clarify the otological and audiological course following acute mastoidectomy. Patients with cholesteatoma and intracranial complications were excluded. Thus, 79 patients with a median age of 16 months were included. Thirty-seven percent had a history of middle ear disease, and the mean duration from onset of symptoms to admission was 9 days. Well-being was affected in 46%, and 82% had fever. The clinical picture was dominated by auricular protrusion (77%) and pathological tympanic membrane (94%). Postauricular oedema, hyperaemia and tenderness were demonstrated in 89%, 78% and 49% of cases, respectively. Peroperatively, purulent middle ear effusion was recognized in 92%, subperiosteal abscess in 66% and pus in the mastoid in 90%. Specimens revealed growth of pathogens in 58%, predominantly Gram-positive bacteria. The observation period was 1-20 years. The findings in operated ears were not significantly different from the contralateral non-operated ears concerning incidence of otitis media, hearing and ear canal volume. Conclusively, acute mastoidectomy is a safe and effective treatment to eliminate infection. The operation can be done with negligible risk and does not leave long-term sequelae.

Acute Disease↗
PubMed2000

Results and experience of 50 cochlear implant operations.

Cochlear implantation (CI) is a relatively new type of treatment that aims to re-establish hearing in deaf people. This paper reports on the results from CI operations on 34 adults and 17 children. All patients benefited from the treatment. The adults' communication with other people improved. Almost all patients use their implant 16 h a day and some of them are able to communicate by telephone. Among children the results show that the treatment is safe, as no complications have developed. Hearing and speech improved in all children, and thus also their ability to communicate. The results obtained are dependent on the individual patient's condition, the time of operation in relation to the development of deafness, and the type of CI used. CI treatment of deaf people may be considered to be one of the greatest advances in otology.

Adolescent↗
PubMed2000

Cortical networks subserving the perception of tinnitus--a PET study.

Subjective tinnitus is an auditory phantom perception that may arise from any aberrant signal within the auditory system. Further processing of this signal and the conscious perception of tinnitus takes place in the cerebral cortex. A few functional brain-imaging studies have been performed to elucidate the underlying cerebral mechanisms of this perception. These studies mostly concern rare types of tinnitus (e.g. tinnitus changeable by oral-facial movements), or compared tinnitus patients with healthy volunteers. These studies attributed variable activation of the primary auditory cortices, associative auditory cortices and the left hippocampus to the perception of tinnitus. Based on these heterogeneous results, no consensus on the underlying mechanisms has been reached. The aim of the present study was to obtain further details of the central perception and processing of the tinnitus signal. Positron emission tomography (PET) was used to map the tinnitus-specific central activity. By contrasting PET-images of suppressed tinnitus with PET-images of the habitual tinnitus sensation, we were able to identify a right prefrontal-temporal network associated with the perception of tinnitus. Besides the evidence of activation of associative auditory sensory regions, the results indicated that activation of cortical centres subserving attention and emotion may underlie the continuous irritability associated with severe tinnitus.

Adult↗
PubMed2000

Reliability and validity of a Danish adaptation of the Tinnitus Handicap Inventory.

The objective of this study was to determine the reliability and validity of a Danish translation of the Tinnitus Handicap Inventory (THI), a self-report measure of perceived tinnitus handicap. The Danish version of the THI was administered to 50 patients reporting tinnitus as their primary complaint or secondary to hearing loss. Construct validity was assessed using tinnitus symptom rating scales, the Beck Depression Inventory (BDI), the State-Trait Anxiety Inventory (STAI), the Tinnitus Coping Style Questionnaire (TCSQ), the Eysenck Personality Questionnaire (EPQ), and perceived tinnitus loudness and pitch. The Danish translation of the THI and its subscales showed good internal consistency reliabilities (c = 0.93 to alpha = 0.74) comparable to those of the original version. High to moderate correlations were observed between THI and psychological distress, tinnitus symptom ratings, neuroticism and maladaptive tinnitus coping. A confirmatory factor analysis failed to validate the three subscales of THI, and high intercorrelations found between the subscales question whether they represent three distinct factors. The results suggest that the Danish THI-Total scale may be a reliable and valid measure of general tinnitus related distress that can be used in a clinical setting to quantify the impact of tinnitus on daily living.

Adult↗
PubMed1999

Effects of family history and place and season of birth on the risk of schizophrenia.

BACKGROUND: Although a family history of schizophrenia is the best-established risk factor for schizophrenia, environmental factors such as the place and season of birth may also be important. METHODS: Using data from the Civil Registration System in Denmark, we established a population-based cohort of 1.75 million persons whose mothers were Danish women born between 1935 and 1978. We linked this cohort to the Danish Psychiatric Central Register and identified 2669 cases of schizophrenia among cohort members and additional cases among their parents. RESULTS: The respective relative risks of schizophrenia for persons with a mother, father, or sibling who had schizophrenia were 9.31 (95 percent confidence interval, 7.24 to 11.96), 7.20 (95 percent confidence interval, 5.10 to 10.16), and 6.99 (95 percent confidence interval, 5.38 to 9.09), as compared with persons with no affected parents or siblings. The risk of schizophrenia was associated with the degree of urbanization of the place of birth (relative risk for the capital vs. rural areas, 2.40; 95 percent confidence interval, 2.13 to 2.70). The risk was also significantly associated with the season of birth; it was highest for births in February and March and lowest for births in August and September. The population attributable risk was 5.5 percent for a history of schizophrenia in a parent or sibling, 34.6 percent for urban place of birth, and 10.5 percent for the season of birth. CONCLUSIONS: Although a history of schizophrenia in a parent or sibling is associated with the highest relative risk of having the disease, the place and season of birth account for many more cases on a population basis.

Adolescent↗
PubMed1999

Exposure to prenatal and childhood infections and the risk of schizophrenia: suggestions from a study of sibship characteristics and influenza prevalence.

BACKGROUND: It has been proposed that infections, perhaps prenatal exposure to the influenza virus, might increase the risk of schizophrenia. To address this hypothesis, we studied the possible influence on schizophrenia risk of sibship characteristics and ecological influenza prevalence data. Birth order and influenza prevalence were used as proxy measures for exposure to prenatal infection, and sibship size and interval to siblings were used as proxy measures for exposure to common childhood infections. METHODS: We established a population-based cohort of 1746366 persons whose mothers were Danish-born women born since 1935 by using data from the Civil Registration System. Schizophrenia in cohort members (n = 2669) and their parents was identified by linkage with the Danish Psychiatric Case Register. Birth order, sibship size, and interval to siblings were calculated for each cohort member based on person-identifiable information on all siblings. The number of notifications of influenza per month in Denmark was obtained from the National Board of Health and Statens Serum Institut. RESULTS: There was no association between birth order and schizophrenia risk or between schizophrenia risk and influenza prevalence during any month of prenatal life. Coming from a large sibship was associated with an increased schizophrenia risk. The relative risks were 1.26 (95% confidence interval [CI], 1.11-1.44) and 1.46 (95% CI, 1.22-1.75) for sibships of 4 and 5 or more, respectively, vs. a sibship of 2. Short interval (<2 years) to the nearest older sibling and nearest younger sibling was associated with a risk of 1.22 (95% CI, 1.05-1.38) and 1.15 (95% CI, 1.03-1.28), respectively, compared with longer intervals. CONCLUSIONS: Our findings do not support the hypothesis that schizophrenia is associated with prenatal exposure to common infections or influenza. However, they are compatible with the hypothesis that environmental exposure, perhaps to common infections in childhood, may be a risk factor, although other explanations are also possible.

Adult↗
PubMed1999

Laser stapedotomy.

Thirty-four ears with conductive hearing loss due to otosclerosis were operated upon using the laser stapedotomy technique. Audiological results were compared with the results of 316 non-laser stapedotomies. The post-operative air-bone gap, calculated as the difference between the post-operative air and bone conduction levels, was smaller with the laser stapedotomy group. Also, the bone conduction showed significant improvement with the use of laser. Significant sensorineural hearing loss was not found in any of the laser-treated patients. According to our results, we concluded that laser is of benefit in stapes surgery for improving the hearing results and minimizing the inner ear trauma.

Adult↗
PubMed1999

Investigations into the natural history of vestibular schwannomas.

In the period from 1977 to 1996 143 vestibular schwannomas were diagnosed in 138 patients in the County of Aarhus, Denmark. The natural history of vestibular schwannomas was observed in 50 patients with 52 tumours who did not undergo immediate surgical removal of their tumour due to small tumour size, advanced age, poor general health and the patients' refusal of surgery. The management included serial CT- or MR-imaging and complete otoneurological evaluation. The imaging interval was between 6 months and 2 years and depended on the recorded growth rate. Thirty-three (64%) of the tumours showed continuous growth with a mean growth rate of 1.6 mm/year. In 11 (21%) of the tumours the size was unchanged and eight (15%) remitted. The last group consisted mainly of the largest tumours. Among the tumours with positive growth, 15 (45%) had a growth rate of 1 mm/year or less. Generally, our findings showed that approximately two-thirds of all the tumours did not grow, were getting smaller or had a growth rate sufficiently small to be simply watched. Additionally, our results suggest that some symptomatic tumours will grow to a certain point whereupon stagnation or remission occurs.

Denmark↗
PubMed1999

Stapedotomy: does prosthesis diameter affect outcome?

Two hundred ears with otosclerosis have been operated upon using a 0.4-mm diameter Teflon platinum piston in 100 ears and a 0.6-mm diameter Teflon piston in the other 100 ears. The postoperative air-bone gap, calculated as the difference between the postoperative air and bone conduction levels, was smaller in the 0.6 mm group for all frequencies except at 2000 Hz, the differences were statistically insignificant except at 4000 Hz. The mean postoperative air-bone gap was 8.6 dB and 7.4 dB for the 0.4 and 0.6 mm groups, respectively, which is statistically insignificant. We found no postoperative loss of bone conduction exceeding 15 dB, there was a deterioration of more than 10 dB in three ears, one in the 0.4 mm group and two in the 0.6 mm group. According to our results, we conclude that the 0.4 mm and the 0.6 mm Teflon prostheses produce the same hearing improvement in stapes surgery for otosclerosis.

Adult↗
PubMed1999

The low-power laser in the treatment of tinnitus.

The purpose of this study was to evaluate the low-power laser on the treatment of tinnitus. In a randomized, prospective, double-blind, placebo-controlled trial, either active or placebo low-power laser irradiation was given through the external acoustic meatus of the affected ear towards the cochlea. The active laser applied 50 mW (cw, 830 nm) over a period of 10 min per session. Forty-nine patients with severe, chronic uni- or bilateral tinnitus were studied. The main outcome was measured using psychoacoustical match of tinnitus loudness and pitch, Visual Analogue Scale (VAS) ratings of subjective loudness, annoyance and attention involved, scores on the Tinnitus Handicap Inventory (THI), the Tinnitus Coping Style Questionnaire (TCSQ), and a number of psychosocial questionnaires. The results showed only moderate (18%) subjective improvement with no statistically significant differences between the effects of the active laser and placebo treatments. Also, there were no statistically significant differences in prepost measurements of tinnitus loudness, VAS scores, THI scores, or TCSQ scores for patients treated with active laser compared with those treated with placebo. We conclude that low-power laser treatment is not indicated in the treatment of tinnitus. Reports of significant benefits of this treatment in previous, mostly uncontrolled or single-blinded studies may be explained by the placebo effect.

Adaptation, Psychological↗