| 1. |
- Molin, M, et al.
(author)
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Mercury, selenium, and glutathione peroxidase in dental personnel.
- 1989
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In: Acta Odontologica Scandinavica. - 0001-6357 .- 1502-3850. ; 47:6, s. 383-90
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Journal article (peer-reviewed)abstract
- Eighteen persons, dentists and nurses, with urinary mercury levels higher than the group median value of all dental personnel in the country of Västerbotten were compared with a group consisting of 15 persons with low urinary mercury levels working in the same clinics. A statistically significant difference between the high urinary mercury group and the low urinary mercury group could be seen in the plasma mercury level. In each group a statistically significant relation could be seen between the plasma mercury level and the total number of amalgam surfaces. The two groups did not differ with regard to the levels of plasma selenium and erythrocyte glutathione peroxidase, and no correlation between these two variables and the plasma mercury levels could be found. To evaluate organ functions, a large number of supplementary analyses were performed. These analyses did not indicate any influence on organ functions. Although the persons in the present study were occupationally exposed to mercury, none of the biologic variables analyzed seemed to be affected. Even among dental personnel who handle amalgam professionally the number of amalgam surfaces is a major contributory factor to the P-mercury level.
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| 2. |
- Molin, M, et al.
(author)
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Plasma-selenium, glutathione peroxidase in erythrocytes and mercury in plasma in patients allegedly subject to oral galvanism.
- 1987
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In: Scandinavian journal of dental research. - 0029-845X. ; 95:4, s. 328-34
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Journal article (peer-reviewed)abstract
- Twelve patients with subjective symptoms, ascribed by the patients themselves to mercury released from dental restorations, were investigated. In addition to a general dental examination the following parameters were registered: the total number of amalgam surfaces in the mouth; potential and polarization of existing and accessible dental metallic restorations for calculation of intraoral currents. As regards the highest calculated intraoral current for each individual there was a statistically significant difference between the patient group and a control group consisting of 12 persons. An analysis of the amount of selenium, glutathione-peroxidase and mercury in the blood showed no differences between the patient and the control group. However, a statistically significant positive correlation could be seen between the total number of amalgam surfaces and the plasma-mercury level for patients and controls pooled together. The numerous other blood parameters analyzed did not reveal any differences between the groups.
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| 3. |
- Bergman, B, et al.
(author)
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Transfer of terbutaline across the human placenta in late pregnancy.
- 1984
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In: European journal of respiratory diseases. Supplement. - 0106-4347. ; 134, s. 81-6
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Journal article (peer-reviewed)abstract
- Placental transfer of terbutaline was studied in 22 women in late pregnancy who were delivered by elective Caesarian section. A single i.v. dose of terbutaline (0.25 or 0.5 mg) was given at various times (13-295 min) before delivery. Immediately after delivery, one blood sample was drawn from the placental side of the umbilical vein and one from the mother's antecubital vein. By use of gas chromatography plus mass spectrometry terbutaline was assayed in maternal plasma and in plasma and whole blood from the umbilical vein. Plasma concentrations in the mothers (Cmv) were initially 7 micrograms/L, while the highest umbilical venous level ( Cuv ) recorded was 3.5 micrograms/L. The ratio Cuv /Cmv increased continuously during the time interval studied and approached unity after 2-3 h. The blood:plasma concentration ratio in venous umbilical blood was initially low. It reached unity after about 60 min, but increased steadily to about 1.5 during the time of study. Thus there was a continuous uptake of terbutaline from plasma into the erythrocytes. The slow in vivo equilibration of terbutaline between plasma and erythrocytes is probably due to the low lipophilicity of the drug. However, the latter characteristic did not seem to impede its diffusion across the placenta to any great degree.
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| 4. |
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| 5. |
- Sennerby, Lars, 1960, et al.
(author)
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Mandibular bone resorption in patients treated with tissue-integrated prostheses and in complete-denture wearers.
- 1988
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In: Acta odontologica Scandinavica. - : Informa UK Limited. - 0001-6357 .- 1502-3850. ; 46:3, s. 135-40
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Journal article (peer-reviewed)abstract
- Mandibular bone resorption was studied in patients treated with tissue-integrated prostheses (TIP) and in complete-denture wearers by distance and area measurements on cephalometric radiographs. The area measurements were performed by means of a computer. Two TIP groups with short and long periods (mean = 2.4 and 23.9 years) of edentulousness and wearing complete dentures before fixture installation were followed up over 7-8 years. Mandibular bone resorption was remarkably small behind the distally positioned fixtures in comparison with the corresponding region in complete-denture wearers. Patients with complete dentures showed a continuous resorption of the mandibular alveolar ridge over 21 years, even though there were great individual variations. The bone loss was most pronounced anteriorly and during the first 2 years after extraction of the residual teeth. It is concluded that treatment with tissue-integrated prostheses seems to reduce bone resorption in the mandible, probably owing to favorable load conditions and adequate stimulation of the bone.
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| 6. |
- Sterner, Olov, et al.
(author)
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Mutagens in larger fungi. I. Forty-eight species screened for mutagenic activity in the Salmonella/microsome assay
- 1982
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In: Mutation Research/Genetic Toxicology. - : Elsevier BV. - 0165-1218. ; 101:4, s. 269-281
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Journal article (peer-reviewed)abstract
- Specimens of large fungi (mushrooms) were screened for mutagenic activity by the Salmonella/microsome assay, with strains TA98, TA2637 and TA100. Out of 48 species tested, 37 exhibited a significant but for the most part weak activity. The activity observed in the presence of S9 mix was typically between 0 and 50% of that without, and in no case was the activity increased in the presence of microsomal enzymes. Six metabolites reported to occur in some of the species included in this investigation were also tested. Significant mutagenic activity was found with isovelleral (5) from Lactarius sp., agaritine (3) from Agaricus bisporus and related sp. and β-nitraminoalanine (7) from Agaricus silvaticus. Isovelleral may be a major mutagen in some of the sharp-tasting and mutagenic Russulaceae sp. A. bisporus (cultivated specimen) was weakly mutagenic toward all three strains of S. typhimurium used, and agaritine was weakly active toward TA2637 alone. This implies that this fungus might contain other mutagenic material as well. β-Nitraminoalanine was not found in the particular collection of A. silvaticus tested here. The mutagenicity observed for the fungus in this work may therefore be due to other metabolites. Even though many species found to be mutagenic are used as food, it seems premature to make specific recommendations about eventual health risks. Further information is needed about the chemistry and toxicology of the active compounds as well as about the effects of various methods used in preparing mushrooms for food.
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| 7. |
- Zoback, Mary Lou, et al.
(author)
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Global patterns of tectonic stress
- 1989
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 341:6240, s. 291-298
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Research review (peer-reviewed)abstract
- Regional patterns of present-day tectonic stress can be used to evaluate the forces acting on the lithosphere and to investigate intraplate seismicity. Most intraplate regions are characterized by a compressional stress regime; extension is limited almost entirely to thermally uplifted regions. In several plates the maximum horizontal stress is subparallel to the direction of absolute plate motion, suggesting that the forces driving the plates also dominate the stress distribution in the plate interior.
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