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Biomedical subjects

T Martinsson

Publications and source records attributed to T Martinsson.

At least 127 records · Page 7Linked to original sources
PubMed1985

Pleiotropic drug resistance and gene amplification in a SEWA mouse tumor cell line. Complex relations revealed by drug uptake data, and lipid and protein analysis.

SEWA mouse lines resistant to actinomycin D (AMD) or vincristine (VCR) exhibit the pleiotropic drug resistance (PDR) phenotype, and express a low-MW protein (p21) and numerous double minutes (DM). In drug uptake studies these lines were compared with the non-resistant parental line and with a methotrexate (MTX)-resistant line, not exhibiting PDR. On treatment with labelled AMD or VCR the two PDR lines displayed a highly reduced intracellular content of drug, whereas uptake of MTX was unchanged. Uptake of AMD was shown to be temperature-dependent. The MTX-resistant line did not exhibit any significant change in AMD or VCR uptake. Other workers have emphasized the role of a high-MW glycoprotein in the development of PDR. A search for a similar glycoprotein in our cells was unsuccessful. Since all indications point to membrane factors being important in the development of PDR, the lines were also subjected to lipid analysis. Compared with control cells distinct differences were detected in the lipid composition of all resistant lines (including the MTX-resistant line). In the course of our experiments, the DM in our most AMD-resistant line were replaced by two homogeneously staining regions (HSR). Simultaneously, the overproduction of p21 ceased, but the PDR phenotype persisted. This event tends to implicate a minor role for the p21 protein in PDR, but similar transitions from DM to HSR in other AMD-resistant SEWA lines were not accompanied by a decrease in p21 over-production. Our data point to a complex genetic control of multi-drug resistance.

Animals↗
PubMed1985

Dental attendance of some of the common immigrant groups in Sweden.

The aim of this study was to see how Greek, Polish, Turkish, Yugoslavian and Finnish immigrants utilized dental services offered, as compared to Swedes. The study covered the years 1976-79, using figures from the National Social Insurance Board (NSIB). All foreign citizens of the aforementioned groups born on the 20th of any month and living in the country of Stockholm were selected, together with a comparison group of Swedish citizens. During the 4 yr in question, only 31% of the Greeks, 50% of the Poles, 28% of the Turks, 40% of the Yugoslavs and 75% of the Finns visited a dentist in Sweden, while 87% of the Swedes did. Few immigrants except some Finns went annually. A great majority of all Greeks, Turks and Yugoslavs either saw a dentist only once or else not at all during the whole period. Emergency treatment was significantly more common for these groups than for Poles, Finns or Swedes. The study revealed a fragmentary and episodic use of the dental services offered to most common immigrant groups in Sweden.

Adult↗
PubMed1985

Computerized registration of epidemiological data from intraoral radiographs.

Software was developed for graphic registration of epidemiological dental data from intraoral radiographs. The measured variables included marginal bone level in relation to tooth and root length as well as proximal caries and restoration areas. Caries and peridontitis progress nowadays slowly in large populations. Registration methods must, therefore, offer high precision. The hard and software were first tested. After that the method's reliability or precision was studied. The precision of measuring marginal bone level as a per cent of total tooth or root length was found to vary between 0.3-4.3. The corresponding precision of measuring a caries area in relation to the whole crown area was 1.4%. Precision was also divided into its components and analysed in more detail. All registered tooth variables except the angle between the proximal marginal bone and the root surface gave satisfactory results indicating good reliability.

Adult↗
PubMed1984

Resistance to actinomycin D and to vincristine induced in a SEWA mouse tumor cell line with concomitant appearance of double minutes and a low molecular weight protein.

By increasing stepwise the drug concentration of the medium, we have induced, in a cell line of the murine SEWA tumor, resistance to actinomycin D (AMD) and vincristine (VCR) 30-50 times above the normal. In both types of resistant cells, we have revealed, by two-dimensional gel electrophoresis, a protein (MW 21K , pI 5) not found in control cells. Large fractions of the resistant cells contained double minutes (DM). In AMD-resistant cells, correlation was demonstrated between number of DM and degree of resistance. Back in AMD-free medium, resistant cells lost both the DM and the 21K protein. Cross-resistance prevailed between AMD and VCR. Cells resistant to AMD and VCR showed erratic resistance to methotrexate (MTX), but no significant resistance existed in the reverse direction.

Animals↗
PubMed1984

Use of dental services by Finnish immigrants in Sweden assessed by questionnaire.

The purpose of this work was to assess the dental visiting behaviour of Finnish immigrants in Sweden, and factors which determined this. The initial material consisted of a probability sample of 1332 Finnish citizens aged 20 to 59 years, resident in a Stockholm suburb. The response rate was 80%. About 23% of the respondents had never been to a dentist in Sweden. They were mostly newly immigrated and had a poor knowledge of Swedish. About 36% of the subjects visited a dentist in Sweden regularly (at least every second year), a lower rate than reported from studies on Swedish populations. Twenty-three per cent of the subjects had on some occasion been to a dentist in Finland while resident in Sweden. Difficulty in getting an appointment, indifference, fear, language difficulties and poor knowledge of the dental care system in Sweden were mentioned as reasons for not attending a dentist. Thus prevailing attitudes as well as the many other problems in connection with immigration seemed to result in dental health being given low priority by Finnish immigrants in Sweden.

Adult↗
PubMed1983

Comparison of use of dental services by finnish immigrants and Swedes using national health statistics.

Dental statistics and treatment information collected by the National Social Insurance Board (NSIB) since the Dental Insurance Scheme was introduced in Sweden in 1974, give a unique opportunity to study the use of dental services by the adult population. Earlier studies showed that adult Finnish immigrants utilized dental services less, and had a greater need of dental care, than the Swedish population. The possible confounding effects of age and social class were not, however, controlled. The aim of this study was to compare use of dental services and dental treatment performed in matched groups of Finnish immigrants and Swedes using central statistics. All Finnish citizens between 17 and 64 yr old born on the 20th of any month and living in the county of Stockholm in 1975, altogether 1378 persons, were selected from the population register. For each Finn a Swedish "social twin" was selected with respect to age, sex and occupation. Information about use of dental services and treatment performed during 1975 was collected from the patient register at the NSIB. The study showed that Finnish immigrants in 1975 visited a dentist less often than the corresponding Swedish group. Those Finnish immigrants who received treatment had had more comprehensive and more expensive care than the Swedish comparison group. The study shows that there were significant differences in use of dental services by and treatment performed on Finnish immigrants and Swedes even when differences in demographic and socioeconomic distribution were controlled.

Adolescent↗
PubMed1980

Social background and dental care habits and attitudes of Finnish immigrants in Sweden.

Foreign citizens today constitute 5% of the Swedish population. While several epidemiological investigations have dealt with dental care habits in the Swedish population, very little is known about the dental care habits of immigrants. This constitutes a factor of uncertainty in the planning of dental care. A random sample of 170 Finnish immigrants, 20-80 years old, in the community of Huddinge was selected. They were summoned to the Faculty Clinics for interview and clinical and radiographic examination. 143 persons appeared for examination. The interview showed that 46.6% of the subjects had never visited a dentist in Sweden though 80% of them intended to remain in Sweden. 19.8% still made more or less regular use of dental services in Finland. The low frequency of utilization of dental services is mainly due to the difficulty in obtaining dental care, lack of knowledge of Swedish, lack of interest and fear of pain. According to the present study Finns in Sweden utilize dental services to a smaller extent than Swedes. The decision of principle adopted by the Swedish parliament in 1968 that immigrants shall be able to live under the same conditions as the Swedes seems not to be fully achieved with regard to the dental care of Finnish immigrants.

Adult↗
PubMed1979

Intraindividual effect of daily supervised flossing on caries in schoolchildren.

The aim was to study the effect of flossing on proximal caries in children grouped according to different combinations of dietary and oral hygiene habits. 140 12--13-year-old children flossed the right or the left lateral region of the mouth once every school-day for 2 years by pulling a waxed floss once up and down through the proximal contacts. Proximal caries was recorded on bitewing films, taken at the baseline and at the 2-year registration. Diet history was obtained four times during the period. Oral hygiene was classified according to the number of bleeding points registered with a feather-loaded probe at the final examination. Caries increments on the control side during the experimental period were calculated for groups with the same habits. A logical border with respect to the amount of new caries was then established between suitable and unsuitable dietary habits as well as between sufficient and insufficient oral hygiene. No statistically significant difference was found between the control and experimental subgroups in the different combinations of dietary and oral hygiene habits, neither with respect to the whole material nor comparable contralateral surfaces. The numerical differences were so small that the technique of flossing studied here cannot be recommended.

Child↗
PubMed1975

Variation of caries frequency with socio-economic background in unselected and extreme groups of 14-year old children in Malmö.

The purpose of the present investigation was to find out whether any correlation exists between socio-economic factors and caries frequency in unselected and extreme groups of 14-year old school children in Malmö. The material consisted of 360 randomly selected 14-year old school children in Malmö (1969) and their parents. The number of DF-surfaces was obtained from the records of the school dental service. Data on the parents' occupation and gross incomes in 1969 were obtained from the tax office in Amlmö. Extreme groups were obtained by chosen those 10% with the highest caries frequency (H'-group) and a corresponding group with the lowest frequency of caries (L'-group). These two subgroups were compared with a selection of 14-year old school children with high (H-group) and low (L-group) caries frequency, which have been analysed earlier in respect of socio-economic background. No significant correlation was found between socio-economic factors and caries frequency in the non-stratified selection. H'-group and L'-group, on the other hand, showed marked differences in socio-economic background. Compared with the H-group, the H'-group showed a higher number of DF-surfaces. This difference was due to variations in distribution of caries between different schools but was not clearly correlated to socio-economic factors. The differences in socio-economic distribution between H'-group and H-group like between L'-group and L-group were not found to be significant. The findings mean that the conclusions drawn regarding socio-economic factors and dental care regarding H- and L-group also can be regarded as representative of schoolchildren with extremely high and low caries frequency, respectively.

Adolescent↗