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Biomedical subjects

H M Borchgrevink

Publications and source records attributed to H M Borchgrevink.

18 recordsLinked to original sources
PubMed2001

[Cochlear implants].

Explore the source record for details and available documents.

Cochlear Implantation↗
PubMed2000

Failure to confirm neurotoxic impairment using cerebral magnetic resonance imaging on solvent-exposed workers.

OBJECTIVES: The study aimed at assessing signs of nervous system impairment by cerebral magnetic resonance imaging (MRI) among workers with a history of long-term exposure to mixtures of organic solvents. METHODS: Thirty-six workers (mean age 44.1 years) with at least 10 (mean 23.9) years of occupational exposure to solvents and pair-matched referents with no former solvent exposure went through a blind, random-order investigation of cerebral MRI, performed with a 1.5-tesla scanner. RESULTS: Linear measurements of the MRI tomograms showed a slight tendency toward wider ventricles and broader cortical sulci in the reference group. Visual evaluation of the MRI by 2 experienced neuroradiologists showed no significant difference between the groups; however, there was substantial interobserver variability. CONCLUSIONS: The MRI findings of this study do not support the hypothesis that long-term low-level occupational exposure to organic solvents results in the development of brain atrophy, or specific MRI signal changes in the region of the basal ganglia and thalami.

Adult↗
PubMed1995

Extended high-frequency thresholds in noise-induced hearing loss.

Air-conduction and bone-conduction thresholds were measured in the conventional audiometric frequency ranges, and air-conduction alone in the extended high-frequency range of 9-18 kHz in 167 males with a history of occupational noise exposure. The subjects were grouped according to age. Hearing loss in the conventional frequency range was classified in different grades. Threshold elevation in the extended high-frequency range was present in all age groups and grades of conventional frequency hearing loss. An age effect in the extended high-frequency range was present only in the lowest grades of conventional frequency noise-induced hearing loss.

Acoustic Stimulation↗
PubMed1994

Neuropsychological findings in a non-clinical sample of workers exposed to solvents.

The risk of long-term damage to the CNS after exposure to mixed solvents in work environments is controversial. Thirty-six workers were studied who had been exposed to organic solvents for more than 10 years (mean 24.5 years) in a working environment. The workers and unexposed controls were studied with a battery of neuropsychological and cognitive tests. Significant group differences were observed for the Wechsler adult intelligence scale (WAIS) digit span and symbol digit substitution, and on paired associate learning and continuous word recognition. The results suggest that long-term work-related exposure to organic solvents may have chronic toxic effects.

Adult↗
PubMed1993

[Music, brain and medicine].

Music lacks the specific sound-concept association that is characteristic of speech, making exchange of information less precise. Nevertheless, verbal language has not replaced musical communication. Music is common to all peoples and cultures, probably because certain impressions and emotions are communicated more successfully by direct musical intuition. Different musical traditions have common features which can be explained by acoustic, auditory and neurobiological mechanisms. Harmonic (consonant) intervals--octave, fifth, fourth, third--play an important role, and are also spontaneously preferred by animals (rats). Pitch and chords are simultaneous patterns that are normally controlled by the right (non-speech) hemisphere of the brain. Rhythm, speech and language, and prosody are sequential patterns that are controlled by the left hemisphere. Musical sounds are stored as structural memory patterns, analogous to poetry or rhyme, independent of comprehension. Simultaneous singing and rhythmic movement facilitate initiation and fluency of speech. Musical functions are included in neuropsychological test batteries. In medicine, music is used as an alternative channel of communication in aphasia and developmental disorders, and in psychotherapy.

Acoustic Stimulation↗
PubMed1991

Attenuation of hearing protectors at 85 dB SPL investigated by commercial "insertion gain" method.

Attenuation of hearing protectors is conventionally measured as the difference between the subject's pure-tone hearing threshold with, and without, hearing protection under free field conditions (loudspeaker) in a sound attenuated (an-echoic) room. This REAT procedure is not objective as it involves the response of a subject. The attenuation can not be measured at noise hazard levels: > 85 dB SPL. Commercial computerized "insertion gain" equipment has recently been developed to improve the individual fitting of hearing aids. By "insertion gain" method a slender silicone probe-tube connected to an outside microphone, is inserted in the ear canal, registering the sound pressure level in front of the tympanic membrane. Thus one can objectively register the sound pressure level difference (gain) obtained close to the tympanic membrane with a given hearing aid in a non-attenuated room. We wanted to study whether the same procedure could be used to assess the attenuation of hearing protectors at noise hazard levels with acceptable measurement variability. With a commercial computerized "insertion gain" equipment (IGO-HAT 1000. Madsen Electronics) we registered the "insertion loss", the difference in sound pressure level measured < 5 mm in front of the tympanic membrane for 20 consecutive sessions (fittings) in the same subject with versus without the same hearing protector. Below 6000 Hz standard deviations were remarkably low--around 2 dB--for the two protectors tested.

Acoustics↗
PubMed1990

[Systemic meningococcal disease in the Norwegian Army].

An outline of aspects of meningococcal disease relevant to The Norwegian armed forces during the last years is given. Epidemiological observations are described as well as ongoing trials with the Norwegian serogroup B outer membrane complex vaccine. These trials are parallel to civilian trials in teenagers. In accordance with the new Norwegian civil guidelines for diagnosis and treatment of meningococcal disease stress is laid on early symptoms of the disease and early treatment (drawing of a blood culture and subsequent prompt parenteral penicillin therapy in the camp when probable meningococcal disease is the case and the estimated transportation time to hospital exceeds about 30 min).

Adult↗
PubMed1990

[Hearing, noise and noise-induced trauma].

As a result of preventive auditory measures in the Norwegian Armed Forces conscripts as a group no longer develop noise induced hearing loss during their service. But the incidence of hearing impairments among 18-year-old Norwegian men before entering military service has increased in recent years and indicates that Norway--and other countries?--should issue noise restrictions also for leisure noise.

Adolescent↗
PubMed1984

Late sequelae after meningococcal disease. A controlled study in young men.

The occurrence of sequelae 3-15 years after meningococcal disease has been investigated in a study on 71 patients and 64 controls. The patients were young men, aged 18 to 24 years at the time the disease was contracted. Participants filled in a questionnaire on possible symptoms. Audiometry and EEG were also carried out. The response rates were 84% among patients and 75% among controls. We found that 61% of the patients had one or more symptoms of possible sequelae compared to 20% in the control group (p less than 0.001). The symptoms were generally light and of mental or neurological type. Among the patients 13% stated that they had obvious complaints commonly attributed to meningococcal disease, compared to 2% only in the controls (p less than 0.05). Twenty-nine per cent of the patients stated that the disease had affected their education or working capacity. No statistical differences between patients and controls were demonstrated by audiological or EEG examinations. In only one single ear could deafness unequivocally be attributed to the disease.

Adolescent↗
PubMed1984

Late sequelae after meningococcal disease as related to anamnestic and clinical factors recorded during the acute illness.

In 71 males who survived acute meningococcal disease 3 to 15 years ago at an age of about 20, associations between acute clinical conditions (including a few pre- and post-admission variables) and late sequelae have been studied. There was a higher rate of sequelae symptoms (mainly light neurological and mental disturbances) among survivors from meningitis (76%) than among those who had had both meningitis and septicemia (58%) or pure septicemia (50%). Twenty percent of control persons experienced such symptoms. "Changed Life" because of serious educational and working problems followed in 29% of the meningitis cases and 70% of the septicemia cases. Most of the clinical and laboratory factors separately examined were not significantly correlated to the sequelae rates. However, less than 2.5 mmol/l glucose in the cerebrospinal fluid (CSF) on admission (p less than 0.01), more than 1000 X 10(6) white blood cells per 1 in the cerebrospinal fluid (p less than 0.05), fever for more than 8 days (p less than 0.05), and probable cerebral symptoms the first week (p less than 0.05), were all positively correlated to a high rate of late sequelae. Well documented early sequelae correlated with serious late sequelae (p = 0.05). No conspicuous associations between acute antibiotic treatment and late sequelae were found. A combination of CSF glucose, blood thrombocytes, and cells in CSF on admission yielded a multiple regression score which seems to be a moderately reliable predictor of sequelae (R = 0.46). Hospital treatment should both aim at avoiding death and escaping residual effects. Because many prognostic factors for sequelae on admission are different from those for lethality, scoring for sequelae may be helpful in such secondary prevention of sequelae. Early standardized registration of sequelae may also be of value in tertiary prevention.

Acute Disease↗
PubMedDate not supplied

The new interventional centre--a multidisciplinary R&D clinic for interventional radiology and minimal access surgery.

The National Hospital wanted to coordinate and promote the development of new minimally invasive procedures by structuring collaboration and communication across traditional speciality boundaries. To achieve this, a new hospital department has been established, a 'neutral ground' for working with such clinical applications in multi-disciplinary teams with surgeons, radiologists, cardiologists etc., individually composed for the type of intervention to be performed. The Interventional Centre also represents a full fusion of a modern radiology department with a state-of-the-art operating department, securing the use of relevant imaging technologies, aseptic conditions and options of converting any 'key-hole' procedure to open, conventional surgery within minutes. The Centre represents a new organizational model for such activities. It is also a technology centre, a common 'tool-box' securing better access and higher quality for the use of advanced radiological and surgical technology in our hospital.

Hospital Departments↗
PubMedDate not supplied

Does health promotion work in relation to noise?

Noise is a health risk. The only scientifically established adverse health effect of noise is noise-induced hearing loss (NIHL). Besides noise may affect quality of life and cause annoyance and sleep disturbance. The present scientific evidence of potential non-auditory effects of noise on health is quite weak. Whether health promotion works in relation to noise may be reflected by permanent hearing threshold shift development in population studies. Hearing impairment continues to be the most prevalent disability in Western societies. The National Institute of Occupational Safety and Health (NIOSH) still rates noise induced hearing loss among the top ten work-related problems. Recent studies report that employees continue to develop noise induced hearing loss although to a lesser extent than before, in spite of occupational hearing conservation programmes. Besides socio-acusis and leisure noise seem to be an increasing hazard to hearing, also in young children and adolescents. This seems partly related to acute leisure noise exposure (e.g. toy pistols, amplified music). However, population studies increasingly find non-normal high-frequency hearing including the characteristic NIHL-"notch" around 6 kHz also in subjects who do not report noise exposure incidents or activities. Today 12.5% of US children 6-19 years show a noise-"notch" in one or both ears (n= 5249, Niskar et al 2001). A Norwegian county audiometry survey on adults >/= 20 years n=51.975) showed mean unscreened thresholds +10 dB at 6 kHz for both genders even or the youngest age group 20-24 years (Borchgrevink et al 2001). Accordingly, the present health promotion initiatives seem insufficient in relation to noise and noise-induced hearing loss.

Adolescent↗