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Biomedical subjects

R Rylander

Publications and source records attributed to R Rylander.

At least 145 records · Page 8Linked to original sources
PubMed1985

Endotoxin in cotton dust and respiratory function decrement among cotton workers in an experimental cardroom.

To study the various reactions of gram-negative bacteria and their endotoxins observed in workers exposed to cotton dust, experiments were undertaken where cotton mill workers carded cottons from different geographic locations, each containing different amounts of bacterial endotoxins. Exposure was determined as the vertical elutriator dust and endotoxin levels. Measurements were made of the forced expiratory volume in one second (FEV1) and the number of blood neutrophils before and after work, and the prevalence of symptoms of byssinosis was recorded. There was a significant correlation between the vertical elutriator endotoxin levels and the group mean changes in FEV1 (p less than 0.01) but no correlation between vertical elutriator dust levels and changes in FEV1. There was also a dose-response relationship between the endotoxin levels and the presence of symptoms of byssinosis in the exposed workers as well as between endotoxin levels and an increase in blood neutrophils. This observation supports findings from several previous studies and suggests that endotoxin triggers the mechanisms responsible for the decrease in respiratory function in the byssinosis syndrome. Other constituents of cotton dust could also be of importance for this reaction.

Adult↗
PubMed1985

Organic dusts and lung reactions--exposure characteristics and mechanisms for disease.

Exposure to organic dusts has been related to pulmonary occupational diseases in a variety of environments. These dusts contain several different agents, but the microbial contamination is always important, particularly regarding molds and Gram-negative bacteria. In the lung, organic dusts cause a series of reactions ranging from irritation with neutrophilic invasion to the initiation of cell mediator release and the development of antibodies. For certain diseases, such as byssinosis, the relation between the cell reactions and the disease is relatively well established; for others, such as allergic alveolitis (hypersensitivity pneumonitis) with fibrosis, more research is needed before the pathogenesis can be established. An understanding of the specific agents causing the disease and the cellular reactions behind its development is essential for its prevention.

Dust↗
PubMed1984

Enzymes in lung lavage fluid after inhalation exposure to silica dust.

Lactate dehydrogenase (LDH) and lysosomal enzyme activity were measured in lung lavage fluid of guinea pigs exposed for 3 weeks to different concentrations of silica dust. Eight weeks and later after cessation of exposure, the amounts of N-acetyl-beta-D-glucosaminidase, cathepsin D, acid phosphatase, and LDH were increased. It is suggested that this increase indicates cell damage to alveolar macrophages, and that the enzyme changes are of relevance to determine the risk for pulmonary fibrosis caused by airborne substances.

Acetylglucosaminidase↗
PubMed1984

Lung cell reactions in guinea pigs exposed to tobacco smoke and silica dust or bacterial lipopolysaccharides.

In order to investigate the possibility of the synergistic effects of tobacco smoke and/or silica dust (SiO2) or bacterial endotoxins (LPS), guinea pigs were exposed to combinations of these agents. A 15-day exposure to SiO2 alone caused a decrease in intracellular lysosomal enzymes of alveolar macrophages (AM) and an increase of lysosomal enzymes detected in lung lavage fluid which was present 16 weeks after exposure. The effect was the same in animals which received SiO2 in combination with tobacco smoke. Exposure to LPS caused an increase in the number of neutrophils recovered in lavage fluid. The increase in neutrophils was less in animals previously exposed to tobacco smoke alone or in combination with LPS. Acute exposure to LPS also caused an increase in lactate dehydrogenase, N-acetyl-beta-D-glucosaminidase and acid phosphatase activity detectable in lung lavage fluid. The increase was less pronounced in animals previously exposed to smoke. Cathepsin D was increased in AM after tobacco smoke exposure alone and was decreased to below control values of the animals which received an acute LPS exposure.

Acetylglucosaminidase↗
PubMed1984

Validation of questionnaire reported miscarriage, malformation and birth weight.

A questionnaire on pregnancy outcome was distributed to 782 women engaged in laboratory work at some time between 1968 and 1979. The response rate was 95%. Reported data on miscarriages, malformations and birth weights were compared to data in hospital records and central registers. Twelve per cent of the reported miscarriages could not be verified. Work with solvents was more frequently reported for these miscarriages as compared to those which could be verified or those which were anamnestically recorded. Fifty per cent of the malformations reported in the questionnaires were also found in registers or hospital records. Regarding birth weights, 28% of the infants had different birth weights reported in questionnaires than were found recorded in the Swedish Medical Birth Register. It is suggested that questionnaire data should be completed with information from sources having a higher validity when the influence of environmental factors on pregnancy outcome is studied.

Abnormalities, Drug-Induced↗
PubMed1984

Asthma and cessation of smoking.

One hundred and twenty-five patients with asthma were questioned on the character of their symptoms in connection with cessation of tobacco smoking. Eighteen out of fifty-nine patients who stopped smoking, reported worsening of their symptoms. The pathogenesis behind this effect may be the effect of tobacco smoke on the immune system particularly macrophages and T cells.

Adult↗
PubMed1984

Airborne endotoxins and humidifier disease.

The presence of humidifier disease in a printing factory was investigated with particular emphasis on airborne endotoxins. The water in the humidifier was contaminated with Pseudomonas. The amount of airborne endotoxin when the humidifier was operating was 0.13-0.39 microgram/m3. Twenty of the fifty workers investigated reported typical symptoms of fever, chills, and chest tightness when the humidifiers were operating. Symptoms were more frequent among non-smokers. The estimated inhaled dose of endotoxin was found to be sufficient to cause the observed symptoms. The determination of airborne endotoxins in future episodes of humidifier disease is recommended.

Air Pollution↗
PubMed1984

Exposure to solvents and outcome of pregnancy in university laboratory employees.

The outcome of pregnancy was studied among personnel employed in laboratory work at the University of Gothenburg between 1968 and 1979. A questionnaire was distributed to 782 women; the response rate was 95%. When the 1160 pregnancies were divided into those with and without exposure to organic solvents during laboratory work, a slightly increased, but not significant, difference in the miscarriage rate was found (relative risk (RR) 1.31, 95% confidence interval 0.89-1.91). No differences in perinatal death rates or the prevalence of malformations were found between infants whose mothers were exposed to solvents and those who were not. Shift work during pregnancy was related to a higher miscarriage rate (RR 3.2, 95% confidence interval 1.36-7.47). No relation between cigarette smoking and miscarriage rate was found, although birth weights were lower when the mother smoked during pregnancy.

Abortion, Spontaneous↗
PubMed1984

Exposure to cotton dust in an experimental cardroom.

Changes in respiratory function (FEV1) and polymorphonuclear neutrophils (PMN) on nasal epithelium were studied in 68 students and 39 cotton mill workers in an experimental cardroom. The exposure was characterised by the vertical elutriator dust and endotoxin levels. A dose related decrease was found for FEV1 which was more pronounced in smoking workers. The thresholds for no FEV1 reaction were 0.58 mg/m3 dust and 0.17 micrograms/m3 endotoxin for students and 0.43 mg/m3 and 0.08 micrograms/m3 for smoking workers. The PMN increased in most of the experiments but no dose response relationship could be shown. In experiments with smoking workers or when washed cotton was carded a better correlation was obtained between FEV1 decrease and endotoxin levels than for dust levels.

Adolescent↗
PubMed1984

Use of questionnaires in occupational studies of pregnancy outcome.

Previous studies have demonstrated a high miscarriage risk among women in laboratories and women exposed to anaesthetic gases. Many of these studies have methodological shortcomings. The aim of the investigation was to study the pregnancy outcome, mainly the miscarriage rate in these occupational groups, and to study such potential sources of error as response bias and inaccurate diagnosis. A questionnaire study was performed among women who had worked at a Swedish hospital as well as women employed in laboratories at the University of Gothenburg (U.G.). Reported pregnancies were accepted only if they could be verified in hospital records or if they were anamnestically reported in medical records. Pregnancies among non-respondents were also sought in medical records. All women suffering a miscarriage after exposure to anaesthetic gases reported their miscarriage while one-third of all miscarriages occurring to women who were not exposed during pregnancy were not reported in the questionnaire. Twelve per cent of the miscarriages among laboratory employees at U.G. could not be verified or found anamnestically in medical records. Work with solvents during pregnancy was more frequently reported for these miscarriages as compared to those which were found in medical records. No significantly increased miscarriage risk after exposure to solvents in laboratory work or to anaesthetic gases could be demonstrated after correction for these errors. It is concluded that use of questionnaires as the only source of information in studies of pregnancy outcome could give biased results and should thus be avoided.

Abortion, Spontaneous↗
PubMed1984

Lung reactions during poultry handling related to dust and bacterial endotoxin levels.

Airborne dust and endotoxin levels on poultry farms, were determined for various working processes known to involve a heavy exposure. Forty-seven workers at different sites were studied by questionnaires for work-related symptoms. Lung function measurements were made before and after work. Dust levels exceeded the standard for organic dust, and endotoxin levels exceeded those known to cause respiratory and other symptoms. The average decrease in FEV1 over the working day(s) ranged from 0.07-0.19 litres. Upper airway irritation was present in one third of the workers, and about 10% complained of chest tightness. The effect may have been due to the high amounts of dust causing a general respiratory irritation as well as to the endotoxin.

Adult↗
PubMed1983

Pulmonary macrophage phagocytosis and enzyme production after in vivo exposure to silica dust.

Guinea pigs were exposed to silica dust (SiO2) aerosols at 6, 13, 28, and 46 mg/m3 for 3 weeks and examined 4, 8, 16, and 23 weeks later. Twenty-four milligrams of TiO2 per cubic meter served as the control dust. Lung weights were increased at 8 weeks and later. Free lung cells showed a tendency to decrease in phagocytosis capacity at 8 weeks after cessation of exposure and later. Alveolar macrophage production of N-acetyl-beta-D-glucosaminidase, cathepsin D, and acid phosphatase was decreased at 8 weeks after exposure and later. The relationship between the depressant effect on macrophages and the absence of an exposure-related polymorphonuclear neutrophil response for the development of fibrosis could be part of the mechanism behind fibrosis.

Animals↗
PubMed1983

Airborne bacteria, endotoxin and fungi in dust in poultry and swine confinement buildings.

Airborne dust in swine and poultry confinements was analyzed to determine concentrations of total and gram-negative bacteria, total fungi, Aspergillus fumigatus and endotoxin. Airborne concentrations of total and gram-negative bacteria in swine and confinement units have been found to be as high as, or higher, than those found in other environments, such as wastewater treatment plants and cotton card rooms, where microbiologically contaminated organic dusts were present. Airborne endotoxin concentrations in the swine units (average 0.12 micrograms/m3) and poultry units (average 0.31 micrograms/m3) were in the range where clinical effects have occurred in other populations. Therefore, health studies of poultry and swine confinement workers with concurrent estimation of the individual daily exposure dose are warranted.

Air↗
PubMed1983

Levels of gram-negative bacteria, Aspergillus fumigatus, dust, and endotoxin at compost plants.

Airborne gram-negative bacteria, endotoxins, dust, and Aspergillus fumigatus were measured in four compost plants in Sweden. At sites where material was processed, the number of airborne A. fumigatus exceeded 10(6)/m3, whereas the number of gram-negative bacteria was usually lower. Dust levels were moderate, and endotoxin levels were well below 0.5 micrograms/m3. Medical studies to evaluate the effects of this type of microbial exposure are recommended.

Air↗
PubMed1983

Work related symptoms among sewage workers.

Employees at six sewage treatment plants and three drinking water plants were interviewed for the presence of specific medical symptoms. Serum immunoglobulin concentrations, white blood cell counts and fibrinogen degradation product concentrations (FDP) in urine were determined as were the number and species of airborne Gram negative rods in order to characterise exposure to aerosols of sewage water. The highest number of bacteria was found in areas where the sewage water was agitated. A significantly higher proportion of employees at sewage treatment plants reported skin disorders, diarrhoea, and other gastrointestinal symptoms than the control group. No significant differences were found between the groups for white blood cell count or serum immunoglobulin concentrations, except that IgM concentrations were slightly higher in the sewage workers. Some workers had serum transaminase concentrations in excess of normal; some of these returned to normal after the summer holiday. Among non-smokers a higher proportion of sewage treatment workers had increased amounts of FDP in urine. It is conceivable that the symptoms observed were caused by toxins from Gram negative bacteria.

Air Microbiology↗
PubMed1983

Reactions during work shift among cotton mill workers.

Lung function and blood neutrophils were measured in 13 cotton mill workers on different days of the work week. Antigen was prepared from cotton dust and a radioallergosorbent (RAST) test made on serum and plasma. The exposure was determined as airborne dust and bacterial endotoxin using vertical elutriators and personal samplers. Reductions in FEV1 and increased blood neutrophils were found on Monday at an exposure level of 0.32 to 0.48 mg respirable dust/m3 and 0.19 to 0.28 micrograms endotoxin/m3. The changes in blood neutrophils correlated with endotoxin levels. The FEV1 decreases were present on Monday but not on Wednesday and Friday. The RAST ratios were low and not correlated with FEV1. No systematic changes in RAST ratios were present over the Monday shift. The results suggest that the importance of immunologic reactions other than type 1 should be investigated.

Air Pollutants↗