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Biomedical subjects

R Rylander

Publications and source records attributed to R Rylander.

At least 109 records · Page 6Linked to original sources
PubMed1989

Lung cell reactions in guinea pigs after inhalation of asbestos (amosite).

To study the long-term effect of inhaled asbestos, guinea-pigs were exposed to airborne amosite at a concentration of 49 mg/m3, 2 h/day for 3 or 6 weeks and examined up to 2 years after exposure. Macrophages in lung lavage fluid (LLF) were increased at 16, 24 and 93 weeks and lymphocytes at 24 weeks. Examination of lung wall cells (LWC) 2 years after exposure compared to cells obtained by LLF showed higher proportions of LWC lymphocytes and neutrophils. Percoll gradient centrifugation of these cells showed a higher proportion of high density macrophages in LLF from the amosite-exposed animal and an increased number of low density lymphocytes in the LW. Cathepsin D was increased in LLF at 8 and 24 weeks and in alveolar macrophages 24 weeks and 2 years after exposure. Fibroblast cultures exposed to LLF did not show any statistical significant changes in their collagen synthesis. Histology 93 weeks after exposure showed macrophage and mediastinal lymph node accumulation of asbestos, as well as collagen in alveolar walls. Granulomas were found in the vicinity of blood vessels and in connection with the bronchioles. The data suggest that amosite at low doses ultimately causes fibrosis with a reaction pattern different from that seen in silicosis. The inflammation and fibrosis seems to develop only within the interstitium.

Administration, Inhalation↗
PubMed1989

Outcome of pregnancy in women engaged in laboratory work at a petrochemical plant.

The aim of the investigation was to study whether laboratory work or other types of chemical work at one petrochemical plant were associated with an increased risk for miscarriage or reduced birthweight. The study was based on questionnaire data for 95% of the women working at the plant between 1973 and 1987. A statistically significant difference between observed and expected number of miscarriages (p less than 0.05) was seen during the period 1970-1974 among women working in one of the laboratories during the first trimester. No suspicions could be raised against any specific chemical as a cause of the unsuccessful pregnancies. The results do not indicate the presence of an increased risk today.

Abortion, Spontaneous↗
PubMed1989

Environmental and health studies of farm workers in Swedish swine confinement buildings.

The relation between the health of workers and the environment in swine confinement buildings was investigated in a study of 57 workers on 30 swine farms in southern Sweden and 55 matched controls. Swine workers reported significantly higher frequencies of respiratory symptoms, more frequent colds and absence due to chest illness, and a history of pneumonia. The increased frequency of symptoms of respiratory disease was related to the number of years and percent of the day spent working with swine. Symptoms were also associated with respirable dust, total dust, endotoxin in total dust, and number of microbes in the air of the work environment. In a multiple regression analysis of the relation between 16 different environmental parameters to work period shifts of five pulmonary function parameters, endotoxin was found to be significantly related to the FEV1 in a dose dependent way.

Agricultural Workers' Diseases↗
PubMed1989

Outcome of pregnancy in relation to irregular and inconvenient work schedules.

The relation between irregular and inconvenient working hours and the outcome of pregnancy was studied among women employed at a hospital in Sweden some time between 1980 and 1984. A questionnaire was distributed to 807 women; 81% replied. The pregnancies were divided into six groups with respect to work schedules during pregnancy. A slightly, but not significantly, increased risk of miscarriage was found in women who worked irregular hours or rotating shifts compared with women who worked only during the day (RR = 1.44, 95% confidence interval 0.83-2.51). Infants of non-smoking mothers who worked irregular hours had significantly lower birth weights than infants of non-smoking women working day time only. This difference was largest at birth order 2+. Similar results were found for infants of this birth order whose non-smoking mothers worked evenings or rotating shift.

Abortion, Spontaneous↗
PubMed1989

Cell recruitment into lung wall and airways of conventional and pathogen-free guinea pigs after inhalation of endotoxin.

The cell kinetics of the acute inflammatory response to inhaled endotoxin (lipopolysaccharide, LPS) was studied in the lungs of conventional (CV) and pathogen-free (SPF) guinea pigs. Airway cells were obtained by bronchoalveolar lavage (BAL). Lung wall cells were prepared via collagenase digestion of lung tissue slices. Acute exposure to LPS triggered the influx within 4 to 12 h of equivalent numbers (approximately 70 x 10(6)) of neutrophils into the lung walls of both CV and SPF guinea pigs. The recruited neutrophils then proceeded into the airways of CV animals, and by 48 h all recruited neutrophils were recoverable by BAL. In contrast, only one third of recruited neutrophils in the lungs of SPF animals moved from the lung wall into the airways. Analysis of neutrophil chemotactic factor (NCF) production identified lung wall cells as the major source of LPS-induced NCF activity in both groups and as virtually the sole source in SPF animals. The results emphasize the importance of studies on the precise lung tissue distribution of both recruited neutrophils, and endogenous NCF-producing cells, in elucidating the acute inflammatory response in the lungs.

Animals↗
PubMed1989

Pulmonary function and symptoms after inhalation of endotoxin.

In previous experiments, a good relationship was demonstrated between the amount of airborne bacterial endotoxin and acute reactions after exposure to organic dusts. In the present study, 77 naive subjects were exposed to isolated endotoxin (IE) or endotoxin attached to bacterial cells (CE). Both preparations were obtained from Enterobacter agglomerans, which is a major bacterial species in many organic dusts. The major physiologic effect caused was a dose-related decrease in transfer factor, as measured by carbon monoxide diffusion. Half of the subjects reported fever and about one-third a subjective feeling of chest tightness. The exposure also caused a dose-related but small decrease in FEV1. A slightly increased bronchial reactivity was demonstrated at 4 h after endotoxin exposure. The minute volume after CO2 exposure was marginally affected. The results further support the conclusions from epidemiologic and experimental studies that the bacterial endotoxin is responsible for the acute reactions seen after exposure to many organic dusts, including that derived from cotton.

Aerosols↗
PubMed1989

Effects of exposure to dust in swine confinement buildings--a working group report.

Pulmonary and other symptoms among workers in swine confinement buildings were evaluated by an international working group. In several studies in five different countries a total of about 2000 workers has been studied in clinical and epidemiologic investigations. Symptoms indicative of acute and chronic airway inflammation were widespread, as were systemic reactions of organic dust toxic syndrome. The base-line, and across workshift, pulmonary function changes were moderate. There was no evidence that antigen-antibody reactions are important in the pathogenesis. Longitudinal studies are recommended to establish the relationship between acute and chronic symptoms and end stage disease.

Agricultural Workers' Diseases↗
PubMed1989

Experimental allergic alveolitis after inhalation of mouldy hay.

Guinea pigs were exposed by inhalation to an aerosol of dust from mouldy hay or cell bound bacterial endotoxins. Pulmonary histology and free lung cells were evaluated 24 hr after exposures lasting from one day to five weeks. In animals exposed to mouldy hay, there was a progressive increase in the number of macrophages and neutrophils and after three weeks a sharp increase in lymphocytes. Following endotoxin exposure, neutrophils increased greatly in number with one day's exposure but after longer exposures, numbers differed little from normal, suggesting adaptation. Histopathology of lungs from animals exposed to mouldy hay demonstrated the presence of alveolar cell infiltrates and early granulomas, that were similar to allergic alveolitis (AA). This model for AA could be used both to assess the importance of different agents in mouldy hay and to evaluate the risk of AA from new kinds of organic dusts.

Aerosols↗
PubMed1988

[Humidifier disease. Role of endotoxins and precipitating antibodies].

A case of an acute form of humidifier disease secondary to the inhalation of endotoxins (humidifier fever) is reported. The respective roles of endotoxins and precipitating antibodies in the diagnosis of the two forms of humidifier disease are discussed. This appears to be an important epidemiological problem in Switzerland, since the authors see approximately one case a month. With respect to treatment, preventive measures are necessary and usually sufficient.

Adult↗
PubMed1988

Life-history correlates of environmental tobacco smoke: a study on nonsmoking Hong Kong Chinese wives with smoking versus nonsmoking husbands.

Studies to evaluate the effects of environmental tobacco smoke (ETS, passive smoking) often use nonsmoking wives with smoking discordant husbands. To see whether there were differences in exposures and behavior patterns among never-smoked wives with never-smoked vs ever-smoked husbands, the life-history profiles of 136 ever-married women with mean age of 59 were analyzed on 97 quantifiable variables. Overall, the results demonstrated that wives with never-smoked husbands had 'healthier' lifestyles than wives with smoking husbands. The former were better off in terms of socio-economic status, more conscientious housewives, ate better diets, and had better indices of family cohesiveness. They also fared better in variables that reflected health status with lower frequencies of the following: miscarriages/abortions, inhaling through the mouth, chronic cough, and chest X-rays. The differences were usually largest when comparing wives of never-smoked vs heavily smoking (greater than 20 cigarettes/day) husbands. The results indicate some correlates of passive smoking that can act as important confounders when evaluating health risks among families with smoking husbands.

Abortion, Spontaneous↗
PubMed1988

Noise annoyance with regard to neurophysiological sensitivity, subjective noise sensitivity and personality variables.

To evaluate the relation between annoyance to environmental noise, general neurophysiological sensitivity, subjective noise sensitivity and other individual characteristics, experiments were undertaken in which 93 subjects assessed their subjective annoyance after exposure to noise under laboratory conditions. Evaluations were made of the discomfort threshold for pulsating sound, the light discomfort, and heat and cold discomfort. The heart rate and discomfort after exposure to a series of impulse noises was also determined. Subjective noise sensitivity, attitudes to noise, mood and personality characteristics of the subjects were evaluated using questionnaires. The results show that the annoyance after exposure to noise was not closely related to the general neurophysiological sensitivity, measured as discomfort threshold for noise, heat, cold and light; or to the heart rate reaction or discomfort after exposure to impulse noise. The annoyance was highly correlated with subjectively reported noise sensitivity and with the attitude to noise. There was also a relationship with neuroticism, measured with the EPI scale. It is suggested that the subjective noise sensitivity, attitude and neuroticism for the definition of noise sensitivity be defined in future studies of long term effects of noise exposure.

Adolescent↗
PubMed1988

Modulation of pulmonary inflammation after endotoxin inhalation with a platelet-activating factor antagonist (48740 RP).

An acute pulmonary response was induced in guinea pigs and hamsters by inhalation of bacterial endotoxin in the form of a purified lipopolysaccharide (LPS). Pretreatment with the platelet-activating factor (PAF) antagonist, 48740 RP, inhibited damage to endothelial cells, decreased vascular permeability and the number of neutrophils in the airways 24 h after exposure to LPS. The increase in the number of platelets in the airways caused by endotoxin was not affected. The results suggest that PAF modulates early inflammation after endotoxin inhalation.

Administration, Inhalation↗
PubMed1988

Modulation of acute endotoxin pulmonary inflammation by a corticosteroid.

The effect of corticosteroid on an acute inflammation in the lungs was studied in guinea pigs exposed to an aerosol of bacterial endotoxin, the subsequent inflammatory response was evaluated counting the number of cells obtained from airway lavage and in the lung interstitium as well as the chemotactic effect of alveolar macrophages. Pretreatment with corticosteroid decreased the number of neutrophils in the airways at 24 hours after exposure but did not influence neutrophils in airways or lung interstitium at 4 hours after exposure, not the secretion of chemotactic factor(s) from alveolar macrophages at that time. It is suggested that the antiinflammatory effect of corticosteroids is a protective effect on the epithelium, preventing the late influx of serum fluid and neutrophils into the airways.

Animals↗