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Biomedical subjects

T Ericson

Publications and source records attributed to T Ericson.

At least 19 recordsLinked to original sources
PubMed2000

Electroosmosis- and pressure-driven chromatography in chips using continuous beds.

The application range of microchips can be extended to any mode of chromatography by filling the narrow channels with continuous polymer beds, exemplified by electrochromatography and ion-exchange chromatography. "Wall effects" are eliminated by anchoring the bed to the wall of the channel, an arrangement which has the additional advantage that no frits to support the bed are required. The design of the equipment is based on a quartz chip with all auxiliary pieces (for example, electrode vessels and fluid transfer fittings) placed in a rack, which permits a flexibility of great importance for automation. The same resolution and van Deemter plots were obtained in experiments performed in fused-silica capillaries and in chips for both low-molecular-weight (alkyl phenones, antidepressants) and high-molecular-weight substances (proteins). A sample of uracil, phenol, and benzyl alcohol was separated by electrochromatography in less than 20 s.

Chromatography, High Pressure Liquid↗
PubMed1997

Saliva and marathon running.

The aim of this study was to follow changes in saliva and serum after strenous prolonged exercise. Twenty individuals, three women and 17 men, 24-62 years old, well-trained but not at elite level, participating in the Stockholm Marathon, were selected for the study. Two of the subjects broke the race after 20 km. Three samples of saliva were collected, i.e. (i) just before the race, (ii) directly after the race, and (iii) 1 h after the race. Paraffin-stimulated whole saliva, resting non-stimulated whole saliva and citric acid-stimulated parotid saliva were investigated. In all three types of saliva, there was a decrease in secretion rate and only 14 of the 18 participants could produce resting non-stimulated whole saliva directly after the race. The salivary concentration of chloride, phosphate, potassium, amylase, hexosamine, sialic acid and salivary peroxidase were significantly higher after than before the race. There were no significant changes in salivary pH and buffer capacity. The total protein concentration was increased in all types of saliva after the race. To conclude, there were several changes in the saliva composition just after the marathon, but most of the values were back to baseline after 1 h of rest. However, the values for sodium, calcium, phosphate, salivary peroxidase, amylase and salivary IgA were still elevated 1 h after the race.

Adult↗
PubMed1997

Cardiovascular disease risk factors and dental caries in adolescents: effect of a preventive program in Northern Sweden (the Norsjö project).

Since 1985 a 10 year prevention programme aiming to reduce cardiovascular diseases (CVD) has been running in the county of Västerbotten in Northern Sweden. The project started in Norsjö. The present investigation is a study on dietary intake, medical CVD risk factors and dental caries in five cross-sectional groups of 15-year-olds during 5 years (1987-1991) of the "Norsjö project". Most of the measured medical and dietary variables followed a similar trend, i.e. a positive trend during the first 3 years (1987-1989) and in the last 2 years (1990-1991) the averages returned towards baseline values. Dental caries prevalence followed a similar trend. Parental educational level did not have a major influence on diet or medical CVD risk factors, but higher caries scores were noted in adolescents with parents with "low" education compared with adolescents where the parents had higher educational levels. The results from the study also point to the fact that dental caries prevalence together with body mass index may indicate adolescents with CVD risk factors at unfavourable levels. Dietary counselling by dental personnel to adolescents with high caries and moderate obesity can be of advantage in reducing caries risk, as well as risk for development of CVD at higher ages.

Adolescent↗
PubMed1997

Rat salivary gland function after fractionated irradiation.

The aim of this study was to investigate longitudinal effects of fractionated irradiation, with various total doses, on salivary gland function in the rat. Female Sprague-Dawley rats were irradiated with 4, 5, 6, 7 or 8 Gy per day on five consecutive days. Irradiation was given to the head and neck region. Whole saliva was collected before and 2, 15 and 26 weeks after irradiation. In general the effects of irradiation on salivary gland function were found to be related to dose and time after exposure. Secretion rates were significantly decreased two weeks after irradiation with doses of 30 Gy or higher, after 15 weeks with 25 Gy or higher, and after 26 weeks with 20 Gy or higher. Response patterns to irradiation differed between the salivary constituents. Thus, the conclusions from this study are that early and late effects display different patterns and that the model used to study variations in salivary gland function after fractionated irradiation must be adjusted to the question addressed.

Animals↗
PubMed1996

Lipids in human saliva.

A simple and reproducible method of determining the quality and quantity of neutral lipids in human saliva was tested. Parotid, submandibular and whole stimulated saliva were collected from 10 healthy adults. The lipids were extracted by the Folch method. A special method for extraction of glycolipids was also tested but gave no additional recovery. Thin-layer chromatography was used for separating the different lipid classes. The concentrations of total lipids in parotid, submandibular and whole stimulated saliva were 0.2, 0.9 and 1.3 mg/dl, respectively. Cholesteryl esters, cholesterol, triglycerides, diglycerides, monoglycerides and free fatty acids accounted for 96-99 percent of the total salivary lipids. Thus, polar lipids such as phospholipids contributed only a minor fraction, indicating that the lipids are not primarily of membrane origin. Ultracentrifugation of saliva samples at d = 1.21 g ml(-1) showed that the salivary lipids did not float like blood plasma lipoproteins. Therefore, they must be in a different state of aggregation from lipids in blood or lymph. No significant lipase activity of the type that acts on plasma lipoproteins was found in parotid or submandibular saliva. The content of free fatty acids and partial glycerides was high.

Adult↗
PubMed1995

Function of the rat salivary glands after exposure to inorganic mercury.

In spite of many studies on the toxicity of mercury, very little is known about the effects of mercury on the function of exocrine glands. In the present paper selected functions of Sprague-Dawley rat salivary glands were studied after the exposure of the animals to inorganic mercury at two different doses; 3.25 mg/kg body weight given during 25 days and 7.0 mg/kg body weight given during 27 days. The function of the salivary glands was estimated by saliva secretion rate, secretion of electrolytes, proteins and biosynthesis of glycoproteins. The function was compared between mercury exposed rats and age and sex matched control rats that were given injections with equal volumes of 0.154 mol/l NaCl on the same time schedule. In the present study we report that no significant effect on saliva secretion rate, concentrations of salivary constituents or biosynthesis of glycoproteins in the salivary glands could be observed in rats as a result of mercury exposure at two levels that gave 30 or 60 times higher serum mercury concentrations than in the majority of the Swedish population.

Animals↗
PubMed1995

Can alpha-tocopherol and beta-carotene supplementation reduce adverse radiation effects on salivary glands?

In this study, we evaluated whether supplementation with antioxidant vitamins can reduce the adverse effects of irradiation on the salivary glands in the rat. Four groups of adult Sprague-Dawley rats were given a basic diet providing 0.6 mg alpha-tocopherol and no beta-carotene per day. In two groups the basic diet was supplemented with 3.4 mg alpha-tocopherol and 6 mg beta-carotene per day from 14 days before irradiation until 12 days after completed irradiation. One group of rats given basic diet and one group given supplemented diet were irradiated with 7 Gy daily for five consecutive days. Isoproterenol and pilocarpine-stimulated whole saliva was collected from all rats 2, 4 and 26 weeks after irradiation. Vitamin-supplemented irradiated rats had higher secretion rates on all three occasions compared with those of irradiated rats given basic diet. The changes in saliva composition seen in irradiated rats were less accentuated in vitamin-supplemented, irradiated rats. The proportions of acinar cells were significantly decreased both in parotid and submandibular glands 26 weeks after irradiation. Supplementation with alpha-tocopherol and beta-carotene did not alter the morphology of the glands.

Animals↗
PubMed1995

Relationship between dental caries and risk factors for atherosclerosis in Swedish adolescents?

In an earlier study on a selected group of adolescents with high caries prevalence we found dietary habits that resembled those considered to promote the development of atherosclerosis. In the present study we have compared DMF-score with factors traditionally associated with the risk for development cardiovascular diseases (CVD). All 15-yr-olds living in an urban community in Northern Sweden 1987-1989 were included. Medical variables related to the risk of developing CVD were evaluated in groups of adolescents with various levels of manifest caries expressed as decayed and filled surfaces (DFS). The proportion of individuals with no medical risk factor at an unfavorable level was significantly higher in a caries free than in a high-caries (DFS > or = 9) group. Adolescents with two or more medical factors reaching unfavorable levels had a significantly higher caries score than the group with no factor at unfavorable level. A significant positive correlation was found for the whole group between DFS-score and relative body weight (body mass index) in an univariate correlation test as well as multiple linear regression analysis. The hypothesis that high caries score can be an indicator for unfavorable levels of traditional risk factors for CVD is not contradicted by the results in the present study but supported by the observed covariation with BMI. We therefore suggest that dietary counseling to adolescents with a high caries score in combination with a moderate obesity can be of advantage in reducing the caries risk as well as the risk for development of CVD at higher ages.

Adolescent↗
PubMed1994

Parotid saliva composition during and after irradiation of head and neck cancer.

Parotid saliva composition was studied before, during and up to 18 months after the irradiation period in 16 cancer patients treated for malignancies in the head and neck region. Stimulated parotid saliva was collected prior to radiotherapy and, when possible, weekly during treatment. New samples were taken 2, 4, 6, 12 and 18 months after the end of radiotherapy. Nine of the 16 patients were treated with bilateral irradiation fields and 7 patients with unilateral irradiation fields, with a total dose not exceeding 52 Gy. During the entire irradiation period the fraction of glands producing measurable volumes of saliva decreased to 40%. In the postirradiation period the number of active glands gradually increased and saliva secretion rate returned to an average of 72% of the initial value 18 months after the end of irradiation. The concentrations of the measured variables increased already during the first week of radiotherapy and at the end of the treatment period the concentrations for total protein, salivary peroxidase, hexosamine and salivary IgA were significantly increased. The concentrations for total protein, salivary peroxidase and salivary IgA were still increased 6 months after the end of irradiation. At the 18-months observation all concentrations had returned to normal, as evaluated in a paired t-test. The majority of glands irradiated with 40-52 Gy recovered not only in secretion rates but also with respect to the components studied in this investigation.

Adult↗
PubMed1992

Parotid gland function during and following radiotherapy of malignancies in the head and neck. A consecutive study of salivary flow and patient discomfort.

Radiotherapy of tumours in the head and neck region usually involves the salivary glands in the treatment volume with ensuing dryness and discomfort. In the present study, a prospective evaluation of the same patients were performed before, during radiotherapy and 6, 12 and 18 months after the end of treatment. Three different groups were outlined, one receiving doses not exceeding 45 Gy, another 47-52 Gy and a third group treated with doses over 64 Gy. All but one of the patients receiving doses less than 52 Gy showed a recovery of secretion beginning after 2 months with a continuous improvement of the salivary flow up to 18 months. Doses exceeding 64 Gy caused irreversibly depressed parotid function in the vast majority of glands. The subjective experience of discomfort with dry mouth was not at all correlated to the initial flow rate. Treatment with unilateral technique and doses below 52 Gy caused just no or slight dryness and 3 out of 4 patients with bilateral involvement of the glands displayed problem with subjective dryness even after 18 months. Doses over 64 Gy with one gland involved had only slight dryness, however, patients with both glands affected showed severe problems with dryness. It has to be emphasised that there were relatively large interindividual differences with respect to salivary flow and discomfort of dryness. It is obvious that these patients need a careful dose planning and a close follow up with co-operation between radiotherapeutists and dentists.

Dose-Response Relationship, Radiation↗
PubMed1992

Prevalence of caries in adolescents in relation to diet.

The aim of the present study was to compare dietary habits between adolescents with high or low dental caries prevalence. All 15-yr-old adolescents living in a small community in Northern Sweden were studied in 1987, 1988, and 1989. The median values for energy and nutrient intake exceeded or were close to the recommendations (SNR89) given by the Swedish National Food Administration. The fiber intake did not reach the recommended daily amount even for the 90th percentile of the studied cohort. Nineteen percent of the adolescents had caries free teeth and 10% had nine or more decayed or filled surfaces. There was no difference in daily sucrose intake or average number of meals per day between these two groups. The group with nine or more decayed or filled surfaces had worse dietary habits, expressed as a higher fat intake, lower intake of complex carbohydrates, and lower density of iron (mg/MJ) than the group with no dental caries. Dietary counseling by dentists should be a valuable addition to other caries prophylactic measures taken by the dentists.

Adolescent↗
PubMed1992

Comprehensive medical examination of a group of patients with alleged adverse effects from dental amalgams.

Mercury from dental amalgams does not seem to cause dose-related intoxications. However, animal studies have shown that high-dose exposure to mercury may support various types of immunologic reactions. Ten patients claiming that their symptoms were caused and aggravated by amalgam therapy were selected for a study of the effects of removal of one amalgam restoration followed by placing of a composite filling. Clinical symptoms and the result of laboratory tests were recorded. Six patients had contact allergies to metals, three of them to mercury ammonium chloride. The comparison of pre- and post-experimental test results showed significant reductions in p-IgE and dU-albumin and significant increases in p-C3d and dU-beta 2-microglobulin. There was no laboratory evidence of a direct toxic effect by mercury on the patients. The observed response by some of the studied factors to the low acute exposure to amalgam may imply that an activation of the immune system occurred.

Adult↗
PubMed1991

Saliva composition and caries development in asthmatic patients treated with beta 2-adrenoceptor agonists: a 4-year follow-up study.

In an earlier study, we found that chronic treatment with beta 2-adrenoceptor agonists in asthmatic subjects gave an impaired saliva secretion and a higher caries prevalence than in healthy controls. Twenty-one of the asthmatics and their matched controls were examined 4 yr later in a follow-up study. Samples of whole saliva stimulated by chewing and parotid saliva stimulated by citric acid were collected and dental caries was scored. In the asthmatic group the secretory rates of stimulated whole and parotid saliva decreased by 20% and 35%, respectively, compared to the control group. The number of lactobacilli increased. The asthmatic subjects had a decreased output per minute of total protein, amylase, hexosamine, salivary peroxidase, lysozyme, secretory IgA, a bacteria-aggregating glycoprotein, potassium, and calcium in stimulated parotid saliva. Initial and manifest caries lesions as well as the number of DFS were significantly increased in the asthma group. We conclude that asthmatic patients treated with beta 2-adrenoceptor agonists have an increased caries susceptibility due to an impaired saliva secretion caused by the use of beta-adrenergic agonists.

Adolescent↗
PubMed1991

Acute radiation effects on saliva composition in rats with different vitamin A levels in serum.

Irradiation of the head and neck often causes loss of salivary gland function which may lead to severe oral discomfort. The effects of a single dose of 25 Gy given to rats with different serum levels of vitamin A were studied. The salivary secretion rate as well as concentrations of protein, hexosamine, amylase and electrolytes, and the activities of two antibacterial glycoproteins were measured. At an adequate level of vitamin A in the diet, irradiation significantly reduced whole saliva secretion rate, and decreased the concentration of salivary sodium, calcium and hexosamine as well as the activity of a glycoprotein agglutinating a serotype c strain of S. mutans. Peroxidase, amylase and potassium were not significantly affected. The reductions seen at an adequate level of vitamin A were not reduced by supplementation of excess dietary retinol. The damage caused by irradiation was enhanced by vitamin A deficiency as seen in the reduced protein and hexosamine concentrations.

Animals↗
PubMed1990

Saliva composition in asthmatic patients after treatment with two dose levels of a beta 2-adrenoceptor agonist.

Changes are known to occur in the salivary composition of asthmatic patients treated with beta 2-adrenoceptor agonists. To evaluate the precise contribution of the agonist to the impaired saliva secretion, 15 asthmatic patients, 15-23 yr old, were given two dose levels of agonist, either terbutaline or salbutamol. The lower dose, 0.15-3.0 mg/day, represented the therapeutic level used by the patients. During a wash-out period of one month, the asthma was treated with budesonide, a corticosteroid spray. Then a daily dose of 32 mg of terbutaline or salbutamol was given for one month. Samples of whole saliva, stimulated by chewing, and parotid saliva, stimulated by citric acid, were collected on three occasions: (1) at the end of the low-dose agonist treatment; (2) at the end of the wash-out period; and (3) at the end of the high-dose agonist treatment. During the high dosing the secretion rate of parotid saliva decreased and the concentrations of its total protein, amylase, hexosamine and the ratio of hexosamine/total protein were lowered. The output per minute of total protein, amylase, hexosamine, peroxidase, lysozyme, secretory IgA and potassium decreased. There were only small differences in secretion rates or saliva composition between samples collected at the end of the low-dose and at the end of the wash-out period. Thus, treatment with beta 2-adrenoceptor agonists impairs saliva secretion in asthmatics.

Adolescent↗