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Biomedical subjects

M Holmström

Publications and source records attributed to M Holmström.

44 records · Page 3Linked to original sources
PubMed1989

Antibody production in rats after long-term exposure to formaldehyde.

Sprague-Dawley rats were vaccinated with pneumococcal polysaccharide antigens and tetanus toxoid to evaluate the immunologic effects of long-term formaldehyde exposure. The antibody response to vaccination was measured 3 to 4 weeks later by enzyme-linked immunosorbent assay. An IgG response to pneumococcal polysaccharides and to tetanus toxoid was found in both the formaldehyde-exposed group and a control group of rats not exposed to formaldehyde. The IgM response to tetanus toxoid was significant in both groups but neither group showed a significant IgM response to pneumococcal polysaccharides. There were thus no signs of impaired B-cell function in rats exposed to a high concentration (12.6 ppm) of formaldehyde for nearly 2 years.

Animals↗
PubMed1988

A clinical follow-up of septal surgery with special attention to the value of preoperative rhinomanometric examination in the decision concerning operation.

A consecutive series of 57 patients who had undergone an operation on the nasal septum was followed up 1.5-3.5 years postoperatively. Rhinomanometric measurements, a clinical examination of the exterior of the nose, and rhinoscopy were performed. These same examinations had been carried out preoperatively and the results recorded preoperatively. The results of the preoperative rhinomanometry were not known to the surgeon and the indication for surgery was based on clinical examination alone. At follow-up the patients also answered a questionnaire. According to the findings at rhinomanometry 52 of the 57 patients had a better airway after the operation. In 11 patients who subjectively did not consider the nasal airway to have been improved by the operation, an allergy or vasomotor rhinitis was found and in some cases the results of preoperative rhinomanometry (total nasal resistance) were normal. To measure the error of the method, a separate series of duplicate measurements was performed on 50 subjects. The standard deviation of the difference between duplicate measurements was found to be 15% of the mean value and the error of the method was considered small enough to justify rhinomanometry as a method for interindividual comparisons, provided the laboratory standard is well known.

Adolescent↗
PubMed1988

Respiratory symptoms and pathophysiological effects of occupational exposure to formaldehyde and wood dust.

The hazards of exposure to formaldehyde have been widely discussed in recent years on account of the health complaints of exposed persons. Both domestic and occupational exposure to formaldehyde is common. In the present study the effects of formaldehyde alone and in combination with wood dust, another nasal irritant, on the upper and lower respiratory tract have been investigated. The effects were correlated with the duration and degree of exposure. Discomfort from both the upper and lower airways was more frequent in the exposed group than in the unexposed group. Nasal obstruction among the exposed subjects in general could not be detected by rhinomanometric measurements, but, for the group exposed to formaldehyde alone and with a history of nasal blocking, there was significant nasal mucosal swelling. The nasal mucociliary clearance was significantly delayed, and the sense of smell was significantly reduced in the exposed groups when they were compared with the referents. Spirometry showed a significantly decreased forced vital capacity in the exposed groups. There were no signs in this investigation that duration of exposure or level of exposure to formaldehyde would have any influence on the severity of symptoms or the impairment of physiological conditions.

Adult↗
PubMed1983

Genetic effects of 2-methoxyethanol and bis(2-methoxyethyl)ether.

2-Methoxyethanol and bis(2-methoxyethyl)ether were subjected to the following assays for genetic toxicity: Ames' test, unscheduled DNA synthesis (UDS) assay in human embryo fibroblasts, sex-linked recessive lethal (SLRL) test in Drosophila, dominant lethal test in male rats, bone marrow metaphase analysis in male and female rats, and the sperm abnormality test in mice. In vivo test animals were exposed to atmospheric concentrations of 25 or 500 ppm 2-methoxyethanol and 250 or 1000 ppm bis(2-methoxyethyl)ether. Point mutations in Ames' test and UDS in fibroblasts were not increased by either compound, while the SLRL test gave ambiguous results which deserve further investigation. Chromosomal aberration frequencies were not increased in rat bone marrow, but there was evidence from the dominant lethal tests that both compounds have profound effects upon male rat fertility during the meiotic phase. Pregnancy frequency was greatly reduced and preimplantation losses were large. In addition, there was evidence of postimplantation losses. Sperm abnormalities were increased in mice exposed to both compounds, but particularly bis(2-methoxyethyl)ether. These effects on male reproductive cells were confined to the higher concentrations of both compounds. It was concluded that the weak mutagenic and particularly the strong antifertility effects described here are important for the safety evaluation of these ethylene glycol ethers.

Animals↗
PubMedDate not supplied

Histological changes in the nasal mucosa in rats after long-term exposure to formaldehyde and wood dust.

Wood dust is a well known nasal carcinogen in man, as formaldehyde is in rats. In certain occupational environments, combined exposure to wood dust and formaldehyde is common. Little is known about the effects of this combination. A pilot study was performed on four groups of Sprague-Dawley rats: one exposed to wood dust (25 mg/m3), another to formaldehyde (12.4 ppm) and a third to both wood dust and formaldehyde; the fourth group served a control group. After 104 weeks of exposure the nose and lungs were examined histologically. One well differentiated squamous cell carcinoma was found in the formaldehyde group. Squamous cell metaplasia was found significantly more often among the formaldehyde-exposed rats. Squamous cell metaplasia with dysplasia was most frequently observed, however, in the group exposed to both formaldehyde and wood dust. There were also significantly more rats with pulmonary emphysema in the groups exposed to wood dust than in the other groups.

Animals↗
PubMedDate not supplied

Histological changes in the nasal mucosa in persons occupationally exposed to formaldehyde alone and in combination with wood dust.

In the nasal mucosa of rodents, both formaldehyde and wood dust have proved to be carcinogenic. Wood dust is also a well-known nasal carcinogen in man. The effects of long-term exposure of humans to formaldehyde, however, are more obscure. In this investigation two groups of workers with well-defined exposure to formaldehyde and to formaldehyde and wood dust, respectively, were compared with a control group regarding histological changes in nasal specimens from the middle turbinate. Significant changes were found in the formaldehyde group but not in the group exposed to both formaldehyde and wood dust. No correlation was found between histological changes and duration of exposure, doses of exposure or smoking habits.

Adult↗