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Biomedical subjects

M Aalto

Publications and source records attributed to M Aalto.

35 records · Page 2Linked to original sources
PubMed1982

Neutralization of the fibrogenic silica-released macrophage factor by antiserum.

Antiserum against the fibrogenic factor from the culture medium of silica-treated rat macrophages was produced in rabbits. In dilution 1: 10,000 the antiserum cancelled the stimulating effect of the culture medium of rat macrophages on the 3H-proline incorporation into granulation-tissue fibroblasts. The rabbit antiserum had variable effects on the stimulation by the media of silica-treated human monocytes, but no effect on the media of cultured human SU-DHL-2-cells.

Animals↗
PubMed1981

Collagen synthesis in cultured mesothelial cells. Response to silica.

Mesothelial cells were isolated from the peritoneal surface of rats using trypsinization. The cells were polygonal-shaped and proliferated rapidly forming confluent cultures. Application of colloidal silica to mesothelial cell cultures in doses known to induce peritoneal adhesion disease was injurious to the cells and reduced their synthesis of total proteins and collagen. This effect was dose dependent. Media from silica-treated mesothelial cells and granulation tissue fibroblasts were applied to similar but non-treated mesothelial cell and granulation tissue fibroblast cultures. Media from SiO2-treated mesothelial cells increased collagen synthesis markedly both in the mesothelial cell and fibroblast cultures compared with the control cultures as estimated from the incorporation of radioactive proline into hydroxy-proline-containing proteins. However, no stimulation of collagen synthesis was induced by media from the SiO2-treated granulation tissue fibroblasts. Similar effects are known to be induced in fibroblast cultured by media from silica-treated peritoneal macrophage cultures. The alkaline ribonuclease activities of the media were decreased in silica-treated mesothelial cell and macrophage cultures but not in the media of fibroblast cultures. These results suggest that mesothelial cells, like macrophages, can interfere with the protein synthesis of fibroblasts and thus contribute to the regeneration of mesothelium after injury and to the formation of adhesions.

Animals↗
PubMed1980

Liberation of a fibrogenic factor from human blood monocytes, ascites cells, cultured histiocytes and transformed mouse macrophages by treatment with SiO2.

Human monocytes and ascites macrophages from cirrhotic patients were isolated in Percoll-gradient and cultured with and without silica. Similar experiments were carried out also with cultured malignant human histiocytes and transformed mouse macrophages. The fibrogenic activity of the culture media was tested by measuring the incorporation of [3H]proline and [3H]thymidine into cultured rat granuloma and human synovial cells. Media from silica-treated monocytes, ascites macrophages and certain histiocyte and mouse macrophage lines caused an increase in the incorporation of both [3H]proline and [3H]thymidine into collagen and DNA, respectively, in both cell systems. Alkaline RNase activities were decreased markedly in the media from silica-treated ascites macrophages but not in the media of the monocytes or histiocytes.

Adult↗
PubMed1979

Glycoproteins from experimental granulation tissue and their effects on collagen synthesis in embryonic chick tendon cells.

Buffer-soluble and pronase-liberated glycoproteins from experimental granulation tissue were fractionated by gel filtration and DEAE-cellulose chromatography. The age of the granuloma was reflected in the gel filtration pattern. Two glycoproteins were isolated, purified to homogeneity and analyzed for their carbohydrate and amino acid compositions. The collagen synthesis in embryonic chick tendon cells was measured in the presence of these fractions, which were found to be inhibiting even at 10(-6) M. These glycoproteins may be significant in the feedback regulation of the development of granulation tissue and fibrosis.

Amino Acids↗
PubMed1979

Effect of SiO2-liberated macrophage factor on protein synthesis in connective tissue in vitro.

1. To elucidate the role of macrophages in fibrosis the effect of the SiO2-liberated macrophage factor was assessed on protein synthesis in granulation-tissue slices. SiO2 could be replaced by chrysotile asbestos. The active factor is found in the 45/55% sucrose interface of macrophage homogenate. 2. There is no evidence of the involvement of collagenase. 3. The SiO2 effect is not influenced by the addition of yeast RNA to the incubation medium. 4. At a small concentration of polyvinylpyridine-N-oxide (PVNO) protein synthesis in the granulation tissue slices is stimulated, but at higher concentrations PVNO prevented the liberation of the fibrogenic factor from macrophages by SiO2. 5. Phospholipase C and trypsin inhibited the effect of SiO2, which was partially abolished also by heating, and by repeated freezing and thawing. 6. The macrophage RNAse, its inhibitors and fibroblast mRNA are suggested as key factors in the development of fibrosis.

Animals↗
PubMed1979

Fractionation of connective-tissue-activating factors from the culture medium of silica-treated macrophages.

The medium of cultured, SiO2-treated peritoneal macrophages contained a factor which enhances the incorporation of labelled proline to collagen and other proteins in granulation tissue slices, cells and polysomes. Simultaneously, the activity of alkaline RNase in the whole medium was decreased in comparison with the corresponding control. Polyvinylpyridine-N-oxide, PVNO, protected the macrophages against SiO2. Latex-particles and E. coli lipopolysaccharide decreased the RNase activity in the macrophage medium, but unlike SiO2 did not cause liberation of the collagen synthesis-stimulating factor. Fractionation of the medium by gel filtration chromatography showed the SiO2-pretreatment to have caused a very significant decrease in the aggregation state of RNase. The fraction from gel filtration chromatography that contained the SiO2-liberated factor stimulating collagen synthesis also contained the disaggregated RNase. There was no RNase-activity in the control sample. A homogenous protein (mol. wt. 14,300) was isolated with repeated gel filtrations from the medium of silica-treated macrophages. It increased the incorporation of 3H proline and 3H thymidine into cultured granuloma cells.

Animals↗
PubMed1973

Amino acid metabolism of experimental granulation tissue in vitro.

1. The intracellular volume in granulation tissue was about 15% of the total urea space. 2. The experimental granuloma has a greater ability to retain amino acids during the proliferation phase than later during the synthesis of collagen. 3. The synthesis of collagen and other proteins by granulation tissue is related to the concentrations of proline and glutamic acid in the medium. 4. The rate of synthesis of proline from glutamic acid in granulation-tissue slices is greatest during collagen synthesis. It is enhanced by lactate. 5. Extracellular cations influence the synthesis of collagen and ouabain is inhibitory. Synthesis of other proteins is less sensitive in this respect. 6. It is suggested that the synthesis of collagen is related to the supply of certain amino acids, especially proline, and hence to the redox balance, and also to the function of the cell wall.

Amino Acids↗
PubMedDate not supplied

Compliance rate and associated factors for entering an alcohol brief intervention treatment programme.

The study aim was to ascertain the compliance rate and to compare associated factors among heavy drinkers willing and unwilling to enter an alcohol brief intervention treatment programme. Patients aged 20-60 years visiting five primary healthcare clinics for any reason were both asked to complete a health questionnaire and interviewed to identify early phase heavy drinkers and to collect sociodemographic and health data. About half of the heavy drinkers (487/1011) complied with a recommendation for brief intervention. Gender, age, drinking variables, smoking, and exercise were associated with compliance. Women and young adults are subgroups of heavy drinkers whose compliance was lower than others and special attention should be given to them when planning brief intervention strategies.

Adult↗
PubMedDate not supplied

Brief intervention for male heavy drinkers in routine general practice: a three-year randomized controlled study.

The aim of this research was to evaluate the effectiveness of long-term brief intervention in routine general practice. In five primary care out-patient clinics in a Finnish town, 296 male early-phase heavy drinkers consulting a general practitioner (GP) for various reasons were identified. Control group C (n = 88) was informed of the risks of drinking after the screening and were advised at the subsequent feedback about 2 weeks later to reduce their drinking. Groups A (n = 109) and B (n = 99) were offered in addition seven and three brief intervention sessions, respectively. All GPs took part, whether or not they indicated a special interest. The main outcome measures were differences between beginning and end-point at 3 years in self-reported alcohol consumption, mean corpuscular volume (MCV), and serum carbohydrate-deficient transferrin, aspartate aminotransferase, alanine aminotransferase and gamma-glutamyltransferase. There were no statistically significant differences between study groups A, B and C in mean changes in outcome measures. Within all the groups, MCV decreased. Depending on the outcome measure used and the study group analysed, clinically significant reduction of drinking was found in 25-53% of the subjects. In routine general practice, giving additional sessions of brief intervention may not be as effective as in special research conditions. Factors reducing the effectiveness of brief intervention programmes should be investigated, so that primary health care staff can be better supported in their efforts.

Adult↗
PubMedDate not supplied

At which drinking level to advise a patient? General practitioners' views.

This study examined the views of 64 general practitioners (GPs) on how much a patient has to drink to be advised by them and compared the results to the recommended Finnish threshold values of heavy drinking. The levels stated by GPs were not too high to prevent early-phase intervention in heavy drinking; rather, they were so low that numerous moderate drinkers were also included. The mean (SD) level was 15.5 (6.5) drinks for male and 11.0 (4.6) drinks for female patients per week. These are about two-thirds of the Finnish threshold values of heavy drinking. Attempting to advise such high proportions of patients, including both heavy and moderate drinkers, might mean a discouraging burden for GPs. However, there may be a discrepancy between GPs' statements about when to advise and when they actually do so.

Adult↗