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Biomedical subjects

G Fosse

Publications and source records attributed to G Fosse.

At least 19 recordsLinked to original sources
PubMed1999

Zinc in primary teeth from children in Norway.

Human primary teeth have been used as indicators of exposure to several heavy metals both in Norway and elsewhere. Local dentists in all 19 counties of Norway collected 2747 primary teeth during 1990-1994. Samples of tooth powder from whole, ground teeth were analyzed for zinc concentration by flame atomic absorption spectrophotometry. The overall geometrical mean was 144.5 micrograms of Zn/g of tooth substance (S.D. = 1.6). The result represents a small increase (5.2%) compared with a similar investigation in the 1970s. However, the mean zinc concentrations in the geographically matching parts of the two materials did not differ significantly. The variation in tooth zinc concentrations between the different counties declined from the 1970s to the 1990s. We found no correlation between the tooth zinc concentration and available environmental data on zinc in drinking-water, discharge of zinc from industrial point sources or population density in the same geographical areas. The zinc concentrations varied significantly with caries status, tooth type and root length. Few samples had a zinc concentration below 90 micrograms/g, indicating that most children consume sufficient zinc. Some very high values could not immediately be explained, but may be caused by contamination from zinc-containing dental restorations.

Child↗
PubMed1998

Man, nutrition and mobility: a comparison of teeth and bone from the Medieval era and the present from Pb and Sr isotopes.

Naturally occurring isotopic systems, such as strontium (Sr) and lead (Pb), are very useful for characterizing different sources and to produce background information. Norwegian teeth from the Medieval era have 206Pb/204Pb ratios between 18.8 and 18.2, in comparison with present day ratios of between 18.0 and 17.6 showing the impact of Pb from modern industrialization and from traffic. Sr analyses of Medieval teeth show that an individual living in a coastal town on the west coast of Norway can easily be distinguished from one in a rural area at that time. The Sr signature shows that Medieval people lived on local products while present people to a greater degree live on imported or domestic industrially processed food. Medieval and modern teeth from one site give similar Pb signatures and concentrations indicating no increase in pollution over time. However, the impact of industrial pollution can be seen from Pb analyses on contemporary teeth, so that the method can be used to monitor emission of heavy metals from local industry. Whilst the Pb and Sr natural isotopic systems individually provide valuable information, a combination of the two techniques is a very powerful tool in environmental and archaeological research.

Animals↗
PubMed1997

Lead in primary teeth from Norway: changes in lead levels from the 1970s to the 1990s.

Lead is one of the most important and widely distributed pollutants in the environment. In the human population children are particularly at risk. Local dentists in all 19 counties in Norway collected 2746 primary teeth from 1990 to 1994. Tooth substance from whole, ground teeth were analyzed for lead concentration by electrothermal atomic absorption spectrophotometry. The geometrical mean for the entire material was 1.27 micrograms lead/g tooth substance (S.D. 1.87). The mean lead levels in each of the counties were significantly lower than those obtained in a corresponding study in the 1970s. Two counties, Oslo and Vest-Agder, had significantly higher lead levels than the majority of the other counties. Tooth lead concentration and atmospheric deposition of lead in the same areas were significantly and positively correlated, as shown by analysis of naturally growing moss. We conclude that lead concentrations in primary teeth from children in Norway have been reduced by approx. 50% from the 1970s to the 1990s. The reduction probably reflects a decrease in the environmental lead burden in Norway.

Air Pollutants↗
PubMed1997

[Expectations from a system of personal general practitioners. A questionnaire study among general practitioners in the municipality of Bergen].

Four municipalities in Norway have tested out a system of personal general practitioners, where all inhabitants aged 12 or more could choose their personal doctor. The doctor's responsibility, work-load and economy were determined by his/her specified list of patients. Doctors employed in primary health care showed a significant interest in the subject, and the ongoing personal doctor trial. To prepare for possible reorganization to this new system in the municipality of Bergen, a survey was carried out in January 1995 among all 145 general practitioners in Bergen, of whom 70% responded. Data from the survey indicated that a larger share of women than men had low expectations concerning a system of personal general practitioners. Only 19 out of 101 general practitioners were positive to introducing such a system.

Attitude of Health Personnel↗
PubMed1994

Autometallographic demonstration of mercury in rat molars.

Male, adult Wistar rats were exposed to 500 micrograms/m3 mercury vapor 6 h per day, 5 days a week for 4 wk. They were subsequently killed by transcardial perfusion. The molars were extracted, demineralized, and embedded in resin before sectioning. Autometallographic development was performed according to the method of Danscher & Möller-Madsen. Mercury deposits were found in small amounts in several areas of the pulp, but with larger accumulations of grains in relation to odontoblasts. Mercury also could be seen in odontoblastic processes in the dentin and predentin. Our conclusion is therefore that systemic uptake of mercury vapor leads to accumulation of mercury in the odontoblasts and that the mercury may be transported into the dentin tubules in the odontoblastic process.

Animals↗
PubMed1993

Mercury in primary teeth in preindustrial Norway.

Seventy-nine primary (deciduous) teeth were excavated in 1978 underneath the floor of the stave church in Uvdal, Buskerud County, Norway. The mercury content of 57 teeth was measured by means of cold vapor atomic absorption spectrophotometry. As a comparison, 124 primary teeth from modern Norway were analyzed. A significant statistical difference was found between the two sets of material. In the Uvdal material a correlation was found between the mercury and copper contents. For the modern material a correlation was found between mercury and lead, and between mercury and zinc. The authors maintain that the values found for the Uvdal material represent base-line values for mercury in primary teeth, and probably reflect uptake from natural environmental sources only. Furthermore, these values may be used for reference in studies of other preindustrial, as well as modern, primary teeth. Our findings also indicate a higher level of mercury in modern than in preindustrial primary teeth in Norway.

Copper↗
PubMed1992

Numerical density and distributional pattern of dentin tubules.

By a new method the numerical density and distributional pattern of transversely cut dentin tubules and the diameters of their peritubular dentin walls were measured in sections near the dentin-enamel junction (DEJ), midway to the pulp, and near the pulp wall in human premolars. For each section the mean and standard deviation of these variables were expressed. At all three levels the measurements comprised the same bundle of tubules from the DEJ to pulp in the coronal dentin. The number of tubules per square millimeter increased more than three times, and the diameters of peritubular dentin decreased one-tenth, whereas central distances between tubules were halved from DEJ to pulp. Thus the pulpward reduction of intertubular dentin is quantified. The distribution of the tubules is not regularly hexagonal, but the distances between them at each given depth are still very uniform in all directions. The pattern of cross-cut tubules often showed distinct short curved rows. The quantitative method might be used to determine taxonomic affinities.

Adolescent↗
PubMed1991

[Distance diagnosis of skin diseases].

During a period of eight weeks in late 1989, doctors in general practice in Kirkenes brought 27 dermatological patients to a studio at the local hospital. Video images were transmitted via a two-way telephone and video network, which enabled the patient and the doctor in Kirkenes to consult a specialist in dermatology in Tromsø. All the patients received written information before the consultation. Anamnestic information and clinical manifestations were presented from the studio at Kirkenes sykehus. The dermatologist diagnosed the disease and prescribed treatment from the studio at the hospital in Tromsø. The technical equipment satisfied our demands for remote diagnostics in dermatology. All the patients were positive to remote consultations.

Computer Communication Networks↗
PubMed1991

[Dental enamel hardness tests in diabetics].

The authors studied by in vivo methods (Fosse et al. 1986) the microhardness of dental enamel in diabetic patients compared to healthy persons. No differences of enamel microhardness values between diabetics and healthy persons, neither by longer diabetes duration nor by worse diabetes attitude have been found.

Adolescent↗
PubMed1991

[Testing of dental enamel hardness by an in vivo method].

The authors studied the microhardness of sound enamel in healthy persons, with in vivo measurements by the Vickersdiamond, used in earlier tests. The evaluation of the impressions was done by a modificated image-analysis method. The method by Fosse et al, for in vivo microhardness measurements can bring good results in practice according to the investigations. The image-analysis makes the evaluation essentially easier. The intraindividual use of this method in longitudinal examinations eliminates the sources of error occurring at horizontal comparisons.

Adult↗
PubMed1987

Scanning electron microscopic study of giant tubule content in bovine dentin.

Incisal segments of unerupted permanent incisors from 1/2-1 1/2-yr-old calves were fractured along an axiomesiodistal plane exposing the organic components within the giant tubule lumina situated in this plane. Along the lining wall of the pulpal vascularized giant tubule portion, large flattened cells and a few odontoblasts were situated in shallow depressions. Just incisal to the vascular loop numerous cells were seen, both along the giant tubule wall and enclosed within a loosely textured collagenous matrix. Further incisally, the number and size of the cells decreased, and they were embedded in a compact unmineralized collagenous matrix that completely filled out the giant tubule lumina. This matrix consisted of fibrils regularly arranged in separate bundles whose orientation was mainly longitudinal. The incisal origins of the giant tubules were filled with coarse fibrils being about three times thicker than those of the luminal matrix and those of the circumpulpal dentin proper.

Animals↗
PubMed1987

Analysis of individual, intraspecific and interspecific variability in quantitative parameters of caprine tooth enamel structure.

Qualitative and quantitative features of mammalian tooth enamel structure are increasingly being used in taxonomic and phylogenetic analyses, although the variability shown by these traits has not received adequate consideration. This study evaluates the variability displayed by nine quantitative parameters in deep, intermediate, and superficial molar enamel in the closely related bovids Ovis aries and Capra hircus. These parameters are assessed in terms of the absolute and/or relative variability evinced at a given depth within a single individual, among conspecific individuals, and between species samples. The degrees of relative variability expressed at a given depth are comparable among conspecific individuals and between taxonomic samples. Nevertheless, in many instances, there are significant differences in absolute variability amongst individuals. Also, in four parameters for which individual specimen averages could be calculated, the equality of these means among conspecifics can be rejected. Variability is not equivalent at different enamel depths. The null hypothesis of equality of individual, conspecific variances can be rejected most commonly for parameters measured in deep and superficial enamel, and coefficients of variation also tend to be higher for deep and superficial enamel than for enamel of intermediate depth. The greater variability displayed by deep and especially superficial enamel may be related to the initial onset and the terminal phase of ameloblastic secretory activity. Taxonomic and phylogenetic analyses that utilize quantitative data on enamel structure are valid only if comparisons have been made at equivalent enamel depths.

Ameloblasts↗
PubMed1986

An in vivo method for microhardness measurements on human teeth.

A non-destructive, in vivo method of measuring the enamel hardness directly on patients is described. Normal values on 39 students are given and compared with those of five patients, one of whom suffered from abnormal oral acid concentration, and the others from the effects of various degrees of hyposialosis caused by radiologic treatment of tumors in head and neck. The difference between the two groups was significant below the 0.1% level. It was suggested that the method may be used to test the degree of salivary gland inactivation after radiologic treatment and the efficiency of different saliva substitutes used to alleviate the effects of hyposialosis.

Adult↗
PubMed1986

Scanning electron microscopic, light microscopic and microradiographic study of giant tubules in bovine dentin.

Giant tubules (GT) in the axiomesiodistal plane of the incisal dentin of 21 unerupted permanent incisors of 1/2-2-yr-old calves were studied by scanning electron microscopy, light microscopy and contact microradiography. A technique is described by which the incisal dentin was split along the axiomesiodistal plane exposing the GT lumina longitudinally for SEM study. The luminal organic content was carefully removed mechanically or chemically. The GT originated 50-250 microns underneath the incisal dentino-enamel junction and converged pulpally, terminating in the incisal edge of the pulp. A confluence of adjacent tubules towards the pulp was seen. Each GT had a relatively constant diameter along its length, in the range of 10-50 micron. The dentinal tubules circumvented the GT origins and pursued a straight course pulpally, parallel to the characteristic wall zone surrounding each GT. Very few dentinal tubules entered the GT lumen at any level. The luminal lining along the larger part of the GT consisted of collagen fibrils forming a criss-cross pattern, while the most pulpal part was lined by a smooth organic sheath. The GT walls at any transversal level within one tooth had a lower mineral content than the circumpulpal dentin between them. It was concluded that the GT formation is not caused by crowding of the odontoblasts.

Animals↗
PubMed1986

Light microscopic study of giant tubules in bovine dentin.

Demineralized, H-E stained longitudinal and transversal sections of unerupted permanent incisors from 1/2-3-yr-old calves were studied by light microscopy. The most incisal dentin in all teeth was characterized by a regular pattern of straight axially oriented giant tubules situated in the axiomesiodistal plane with interglobular dentin between them. In younger teeth, the pulpal part of every giant tubule contained an afferent and an efferent blood vessel, forming a hairpin loop and being surrounded by basophil cells. Incisal to the blood vessel loops, cells enbedded in an eosinophil matrix were present in the giant tubule lumina, showing increasing degenerative changes incisally. In older teeth there was a mesiodistally extended eosinophil dentin band near the pulp, with few, irregularly arranged, tortuous dentinal and giant tubules, the latter containing single blood vessels accompanied by pulpal cells. Isolated degenerating odontoblasts in lacunar cavities were seen in the transition area of the normal circumpulpal dentin and the eosinophil dentin band. A hypothesis on the initiation and subsequent development of giant tubules is presented.

Animals↗
PubMed1984

Histochemical study of giant tubule content in dentin of unerupted cow incisors.

Incisal dentin of mandible cow incisors was studied by incident light. The material consisted of 12 intact permanent unerupted incisors from 2-yr-old cows removed immediately after bleeding. These specimens were kept in an isotonic EDTA-sucrose solution to be decalcified while maintaining vitality of cellular components. Three of the specimens were successfully dissected in a mesiodistal plane, exposing the giant tubule lumens and their content. By the use of NBT, a compound reduced by the dehydrogenase enzymes of the electron transport in the inner mitochondrial membrane, it was concluded that the giant tubules contained vital cells. The giant tubules were also shown to communicate with the incisal part of the pulp cavity by wide openings.

Animals↗
PubMed1981

Microstructure and chemical composition of fossil mammalian teeth.

Sectioned Cretaceous mammalian teeth were studied by light microscopy and SEM equipment with an electron microprobe. Structures resembling odontoblast processes were found. Their S/Fe ratio was similar to that of rat odontoblast processes, but the amounts of these elements were far higher than in processes of recent teeth. It was concluded that they consisted of pyrite, but their reaction with mercurochrome indicated presence of proteins with SH groups. Fluorescence microscopy indicated traces of collagen in the dentin. In the fossil enamel and dentin the Ca/P ratio was similar to that of recent teeth. Two samples of fossil teeth were analyzed for Pb, Cd, Zn, and Cu content by atomic absorption spectrophotometry. The levels of the latter two elements were normal, whereas that of Cd and especially that of Pb were higher than in laboratory rats. The probability that original protein fractions exist and that the different elements were those of the living animals is discussed.

Animals↗