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Biomedical subjects

M Berg

Publications and source records attributed to M Berg.

At least 37 records · Page 2Linked to original sources
PubMed1991

[Selective resection of the lateral semicircular canal with hearing preservation--an animal experiment study].

The goal of our investigation was to develop a method for removing parts of the vestibular labyrinth by surgery without inducing a loss of auditory function. Three different surgical lesions were created in the lateral semicircular canal of the rabbit: (1) fenestration; (2) fibrin glue perfusion of the canal following fenestration; and (3) destruction of the semicircular canal by drilling after fenestration and fibrin glue perfusion. Brain-stem auditory potentials were recorded repeatedly up to 3 months after operation. They demonstrated preservation of hearing in all rabbits in the first group, in 78% of the second and 67% of the third group. In the last group a 20 dB deterioration of hearing was regularly noticed. Histological study revealed the utmost importance of the fibrin glue perfusion of the perilymph space of the semicircular canal inducing an interruption of the peri- and endolymph flow. A precise microsurgical technique was crucial for hearing preservation.

Animals↗
PubMed1991

Evaluation of a questionnaire used in dermatological epidemiology. Discrepancy between self-reported symptoms and objective signs.

A questionnaire about facial skin problems was answered by 3745 office employees with the aim of discovering whether VDU work causes skin disease. From this group, 809 randomly selected persons were examined and interviewed by a dermatologist. There was a relatively good correspondence (87%) between the results from the interviews and the questionnaires, but the questionnaire results corresponded to current status in only 46% of the cases. No important difference was seen between those who were informed and those who were not informed about the purpose of the investigation. There was a relatively wide variation in the correlation between two responses to the same questions. In conclusion, the self-administered questionnaire seems to give reasonably adequate answers regarding the occurrence of more clear-cut symptoms over a period of time, rather than answers regarding the presence of signs at a particular point in time. However, less marked changes might not be picked up particularly well and the use of questionnaires alone cannot be recommended when studying mild skin problems due to a particular exposure in a population.

Computer Terminals↗
PubMed1991

Skin problems in users of video display terminals. Discrepancy between subjective symptoms and objective signs.

The skin has become a target organ for concerns related to work with video display units (VDU). The aim of this investigation was to describe the clinical picture, to investigate whether skin problems are more common in VDU-exposed persons than in non-exposed controls, whether there are differences in objective and/or subjective symptoms and signs, and whether there is a "specific" dermatosis associated with VDU work. A self-reported questionnaire was mailed to 3,877 individuals. One out of five questions concerned the presence of skin problems. Of this group, 809 underwent a clinical dermatological evaluation in addition to filling out a structured questionnaire. Self-reported skin symptoms increased with increasing exposure to the VDU. The clinical diagnosis, based on objective signs and anamnestic data showed a somewhat attenuated association with exposure. The status diagnosis, based solely on objective signs, failed to show any association to VDU exposure. Unilateral skin rashes occurred at the same frequency in the exposed and the non-exposed groups. It is concluded that there is nothing in this investigation, or in any other investigation, that would speak against the notion that VDU-related skin problems and the allergy to electricity is just another facet of the "20th century syndrome". It is possible that individuals suffering from this condition, are conditioned to respond to certain stimuli by neurogenic release of mediators.

Computer Terminals↗
PubMed1991

[Sound localization in patients with asymmetrical hearing loss].

Good directional hearing ability demands good and symmetrical hearing in both ears. We report the effect of impaired hearing on the directional hearing ability of 98 patients, especially of patients with bilateral asymmetrical hearing loss. The directional testing device included 12 loudspeakers placed at 30 degree intervals in a circle with a diameter of 3.25 m, whose centre lay between the ears of the patient. In included an audiometer for producing the signals, an amplifier and a PDP11/23 computer interfaced to a loudspeaker switch bank. The subject's answers to 60 directionally randomized stimuli were recorded. During the presentation of the signal the patients were not allowed to turn their head. The patients had to name the number of the loudspeaker on the circle that they thought was producing the sound. In addition to the directional hearing test a pure-tone audiogram was done, and the middle- and high-frequency hearing loss estimated. The records of the directional hearing test were analysed in two new ways: firstly, vector analysis of the errors; secondly, averaging of the difference between the true interaural time delay and the virtual time difference, which was implicated in the possibly incorrect answer of the patient (effective delta-t-parameter). This average gives a score for the uncertainty in defining the correct "cone of confusion". In addition to the statistical analysis, two cases are reported showing the directional hearing ability of two patients with neuromas treated by transtemporal surgery, with some residual hearing.(ABSTRACT TRUNCATED AT 250 WORDS)

Audiometry↗
PubMed1990

Human neutrophils release the Leu-8 lymph node homing receptor during cell activation.

The Leu-8 molecule, the human homologue of the murine MEL-14 peripheral lymph node homing receptor, is expressed on neutrophils in both species and may be important in localization of cells to sites of inflammation. Most circulating human neutrophils express the Leu-8 molecule, and activation of neutrophils with phorbol myristate acetate causes a rapid decline in Leu-8 membrane fluorescence staining within 15 minutes. Northern blot analysis of total cellular RNA from neutrophils demonstrated two species of Leu-8 messenger RNA, a major one of 2.4 kb and a minor one of 1.9 kb. Because two different Leu-8 cDNA clones were obtained from human lymphocytes that were predicted to encode both transmembrane and phosphatidylinositol (PI)-anchored forms of the molecule, experiments were conducted to determine whether Leu-8 is anchored to neutrophils by a PI-anchor. There was a slight decrease in expression of Leu-8 on neutrophils when they were treated with PI-specific phospholipase C (PI-PLC). However, Leu-8 was abundant on neutrophils obtained from a patient with paroxysmal nocturnal hemoglobinuria. To determine the fate of the Leu-8 molecule during cell activation, neutrophils were labeled with 125I-anti-Leu-8. During activation antibody was rapidly lost from the cell surface and was not internalized, suggesting that Leu-8 is released from the cell membrane during cell activation. When cell extracts of neutrophils were compared with extracts of lymphoid cells by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting, the Leu-8 species expressed on neutrophils had a significantly higher and more variable relative mobility (70 to 120 Kd for neutrophils v 70 Kd for Jurkat T cells). In addition, Leu-8 molecules were detected in the supernatants of activated neutrophils. These results indicate that human neutrophils express a high-molecular-weight form of the Leu-8 molecule that has a conventional transmembrane anchor and is rapidly released from the membrane during activation. The loss of the Leu-8 membrane glycoprotein during activation may be a mechanism for rapid alteration of neutrophil adhesion characteristics.

Blotting, Western↗
PubMed1990

Close relationship between mink influenza (H10N4) and concomitantly circulating avian influenza viruses.

Strains of an influenza H10N4 virus have been isolated during an outbreak of a respiratory disease in mink on the south-east coast of Sweden. This was the first example of a disease in mammals caused by the H10 subtype. We compared the A/mink/Sweden/84 strain with two recent avian H10N4 isolates, one from fowl and another from a mallard, both isolated in Great Britain in 1985 as well as the prototype A/chicken/Germany/N/49 (H10N7). The comparison was carried out by genomic analysis of the strains by oligonucleotide fingerprinting and in bioassays on mink. The oligonucleotide fingerprint analysis revealed a high degree of genomic homology of around 98% between the viruses from mink, mallard and fowl. Only the recent avian isolates, that from the mallard and fowl could infect mink by contact, causing similar pathological and clinical signs and inducing seroconversion as did the mink virus. However, the susceptibility of mink to the fowl and mallard viruses by contact was less pronounced than that to the mink virus. Both the genomic homology and the similarities from the infectivity and pathogenicity studies between the mink virus and the recent avian isolates point to a direct invasion of the mink population by an avian H10N4 virus.

Animals↗
PubMed1990

Marked spontaneous improvement in ejection fraction in patients with congestive heart failure.

PURPOSE: The overall prognosis for patients with congestive heart failure is poor. Defining specific populations that might demonstrate improved survival has been difficult. We therefore examined our patient database for patients with congestive heart failure who demonstrated sustained improvement in left ventricular function and associated resolution of signs and symptoms of congestive heart failure. PATIENTS AND METHODS: We identified 11 patients with severe congestive heart failure (average ejection fraction 21.9 +/- 4.23% (+/- SD) who developed spontaneous, marked improvement over a period of follow-up lasting 4.25 +/- 1.49 years. All 11 patients were initially symptomatic with exertional dyspnea and fatigue for a minimum duration of 3 months. They form a subset of a larger group of 97 patients with chronic congestive heart failure that we have followed with sequential ejection fraction measurements. All 11 patients were treated with digitalis diuretics, and either converting-enzyme inhibitors or a combination of isosorbide dinitrate and hydralazine. Ten of the 11 patients had a history consistent with chronic alcoholism, and each reportedly abstained from alcohol during follow-up. RESULTS: During the follow-up period, the average ejection fraction improved in 11 patients from 21.9 +/- 4.23% to 56.64 +/- 10.22%. Late follow-up indicates an average ejection fraction of 52.6 +/- 8.55% for the group. Congestive heart failure resolved in each case. CONCLUSIONS: We conclude that selected patients with severe congestive heart failure can markedly improve their left ventricular function in association with complete resolution of heart failure. This appears to be particularly evident in those patients with chronic alcoholism who subsequently abstain.

Aged↗
PubMed1990

Facial skin complaints and work at visual display units. An epidemiologic study of office employees.

A questionnaire about skin rashes and their symptoms was sent to 3877 randomly selected office employees with different degrees of exposure to video display units (participation rate 96.6%). From this group 809 randomly selected persons were examined and interviewed. Itching and burning sensations with few visible signs were more common among persons who were highly exposed than among those in the nonexposed category. Objective facial signs were not significantly more common among persons in the highly exposed category. No dose-response effect was observed regarding the amount of video display unit exposure and objective skin signs. Unilateral skin rashes and skin malignancies were found in the same frequency in both highly exposed and the nonexposed persons. This study does not provide support for the hypothesis that video display unit work induces any recognized type of facial skin disease.

Adult↗
PubMed1990

Genetic drift of equine 2 influenza A virus (H3N8), 1963-1988: analysis by oligonucleotide mapping.

Comparative analysis by RNA oligonucleotide fingerprints of total genomic RNA as well as the individual RNA segments of equine 2 influenza A virus strains from 1963, 1968, 1979, 1984, 1987 and 1988 revealed genetic diversity. Strains from the epizootic outbreak during 1978-1979 showed minor differences among their genomes. The Swedish isolates from 1979 up to 1988 showed increasing genomic heterogeneity indicating genetic drift.

Animals↗
PubMed1990

The structural proteins of a porcine paramyxovirus (LPMV).

The porcine paramyxovirus is a newly identified agent of a fatal disease in piglets, endemic in Mexico since 1980, where it was seen around the town of La Piedad, Michoacan, Mexico (hence LPM virus). At least six [35S]methionine-labelled proteins could be resolved by SDS-PAGE and five of them were clearly immunoprecipitated. Selective labelling of LPMV-infected cells with [3H]glucosamine revealed two bands with an Mr of about 66K and 59K, corresponding to the two viral glycoproteins, the haemagglutinin-neuraminidase protein and the fusion protein. Labelling of virus with [32P]orthophosphate disclosed one band with an Mr of 52K, corresponding to the phosphoprotein. Analysis of nucleocapsids obtained from purified virus or from a permanently infected cell line revealed one major band with an Mr of 68K, the nucleoprotein. Two other proteins were also identified, the large protein and the matrix protein, with apparent Mr of about 200K and 40K, respectively. The protein migration pattern of LPMV was compared, by SDS-PAGE, with that of Newcastle disease virus, bovine parainfluenza 3 virus and Sendai virus. Differences in the Mr of LPMV proteins and the proteins of these paramyxoviruses were observed. We propose that LPMV should be classified as a novel member of the genus Paramyxovirus.

Animals↗
PubMed1990

Familial myoedema, muscular hypertrophy and stiffness.

A father and son with muscular hypertrophy, stiffness and myoedema are described. The local swelling after tapping the muscle was not accompanied by electrical activity. Histological and histochemical studies of muscle biopsy showed no abnormalities. Electron-microscopy showed multiple vacuoles to be due to T-tubule dilatation. Further studies are necessary to determine the significance of this finding in the pathogenesis of muscle sensitivity to mechanical irritation in this rare syndrome.

Adolescent↗
PubMed1990

Evaluation of a questionnaire for facial skin complaints related to work at visual display units.

A questionnaire about facial skin problems was answered by 3745 office employees, with the aim of discovering whether VDU work causes skin disease. From this group, 809 randomly selected persons were examined and interviewed by a dermatologist. There was a relatively good correspondence (87%) between the results from the interviews and the questionnaires, but the questionnaire results corresponded to current status in only 46% of the cases. No important difference was seen between those who were informed and those who were not informed about the purpose of the investigation. There was a relatively wide variation in the correlation between 2 responses to the same questions. In conclusion, the self-administered questionnaire seems to give reasonably adequate answers regarding the occurrence of more clear-cut symptoms over a period of time, rather than answers regarding the presence of signs at a particular point in time. However, less marked changes might not be picked up particularly well.

Computer Systems↗
PubMed1990

Facial skin complaints and work at visual display units. A histopathological study.

Facial punch biopsies from 83 patients with skin complaints with or without skin lesions and supposedly associated with work at visual display units (VDUs) were compared to biopsies from 51 subjects with no VDU exposure with or without skin lesions. Coded slides were assessed by three independent observers regarding hyperplasia of sebaceous glands, occurrence of telangiectases, intensity of inflammatory infiltrate, degree of hydropic degeneration of basal cells, occurrence of demodex folliculorum, number of mast cells and degree of degenerative changes in elastic fibers. No parameter was significantly more common in exposed subjects than in non-exposed persons with equivalent skin signs. The controls without skin lesions also showed various degrees of histologic changes. Hyperplasia of sebaceous glands was more common in men and in young persons. Degenerative changes in elastic fibers increased with age, but were also obvious in some persons under 35 years of age. In this study no characteristic histologic changes in facial skin were found in individuals with skin symptoms claimed to be associated with exposure to VDUs.

Adult↗