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Biomedical subjects

A Axelsson

Publications and source records attributed to A Axelsson.

At least 127 records · Page 7Linked to original sources
PubMed1978

Aspects on personal noise protection.

Two groups of noise-exposed workers were compared with respect to their use of ear protectors. One group had a severe, noise-induced hearing loss; the other group had normal hearing. Both groups were composed of workers of similar age and total duration noise-exposure. It was found that those with normal hearing had used ear protectors considerably more than those with severe hearing loss. Interestingly, quite a few workers had normal hearing in spite of working in noise for many years without ear protectors. Also, quite a few workers had a severe hearing loss in spite of frequent use of ear protectors. The reasons for not using ear protectors were analysed as also was the condition of the protectors and frequency with which they were replaced. Plastic ear plugs were preferred by 44%, vinyl foam ear plugs by 26%, fibreglass down by 18%, and ear muffs by 11% of the workers. In general, the condition of the ear protectors was good. Surprisingly, one-third of the workers did not use ear protectors, many of them because they had not realized that the environment they worked in had a noise intensity level above the injury risk level.

Auditory Threshold↗
PubMed1977

Histology of the cochlear vessels in the guinea pig.

Normal adult guinea pigs were studied in phase contrast microscopy. Perivascular spaces were clearly more common in vessels facing perilymph than in vessels facing endolymph. The so-called "avascular channels" which have been suggested to signify a degenerative phenomenon were found in some inner ear vessels in the normal animal. These sections of vessels, lacking blood cells, may constitute a normal vessel, subjected to plasma skimming. Small openings were found on some of these "avascular channels". Both perivascular spaces and "avascular channels" appear to be a part of the fluid transport system in the cochlea.

Animals↗
PubMed1977

Factors increasing the risk for hearing loss in 'pop' musicians.

Hearing thresholds were determined in 83 'pop' musicians with an average age of 26 years, average exposure time of 9 years and average weekly exposure time of 18 hours. The following factors had a statistically significant influence (p 95) on hearing: ageing, brief exposure per session, long exposure time in years (2 kHz), participation in military service (250 Hz), listening to pop music with head phones (2 kHz).

Adult↗
PubMed1976

Symptoms and signs of acute maxillary sinusitis.

Symptoms and signs of acute maxillary sinusitis have seldom been specifically analyzed. Since there is a gradual transition from rhinitis to sinusitis it can be expected that many symptoms are common for the two diseases. However, since sinusitis requires drainage measures and/or antibiotic treatment, both of which seldom are actual for rhinitis, the differential diagnosis is important. The present investigation confirms most of the symptoms presented previously in textbooks. However, most of these sympatoms which conventionally are supposed to indicate sinus disease were found to be just as common in radiologically normal sinuses and in sinuses with pronounced changes. The subjective or objective finding of purulent nasal secretion was more helpful in the differentiation between rhinitis and sinusitis. It appears that the patient's symptoms do not constitute a reliable diagnostic basis for the confident differentiation between the two diseases. The simplest and least discomfortable means of demonstrating sinusitis is by radiology.

Acute Disease↗
PubMed1976

Studies on Branhamella Catarrhalis (Neisseria catarrhalis) with special reference to maxillary sinusitis.

Paired sera from 97 patients with acute maxillary sinusitis were examined regarding antibodies to Branhamella catarrhalis. Precipitating antibodies were demonstrated in almost all sera both from patients and from healthy blood donors. Complement-fixing (CF) antibodies to B. catarrhalis were present in sera from 25 of the 97 patients and in one of 20 healthy blood donors. The titres were low and the titre changes when present were of a small magnitude. CF antibodies were most commonly demonstrated in the younger age groups. The patients with demonstrable CF antibodies to B. catarrhalis did not differ from patients without antibodies regarding radiological appearance or healing during therapy. Strains of B. catarrhalis were all rapidly killed by normal human serum but not in heated sera. The strains could not multiplicate significantly at an oxygen tension corresponding to about half the atmospheric value. The possible significance of the serological and bacteriological findings is discussed.

Acute Disease↗
PubMed1975

Experimental aural barotrauma. Electrophysiological and morphological findings.

The electrophysiological findings show a time and pressure related decrease in function of the CM and the N1 potentials. Sudden changes were correlated with tympanic membrane perforations. Some of the decreased function is accounted for by middle ear effusion and hemorrhages, reducing mechanically the transmission of sound energy through the middle ear. This was evidenced by an improvement of function when the fluids were removed. Remaining decreases in function were interpreted as a result of influences on the inner ear function or of undisclosed middle ear changes. No differences were noted in cochlear function between animals subjected to sustained or intermittent middle ear pressures. Neither were any morphological differences noted between these two groups in the middle or inner ear. The morphological middle ear findings correlated well with previous clinically and experimentally induced changes with increased/decreased middle ear pressure. The cochlear findings include the interesting observation of an intact round window membrane, a clear endolymph, and a normal Organ of Corti in all cases. Positive findings were a high frequency of hemorrhage, most commonly demonstrated in the scala tympani of the basal turn close to the round window. The origin of the hemorrhages could not be demonstrated with the present investigation. The hemorrhages often appeared to be related to the cochlear aqueduct. The occurrence of hemorrhage was clearly related to increased negative pressure, and the non-existence of hemorrhage was always related to either tympanic membrane perforations or low applied pressure. Further frequent findings were distention, collapse, and rupture of the inner ear membranes which must be interpreted with great circumspection due to the method used. Likewise, some of the pathological cochlear findings may be due to pathological conditions which are not necessarily related to induced middle ear pressure.

Acoustic Stimulation↗