PubMed Health⌕ Search

Biomedical subjects

M Ryberg

Publications and source records attributed to M Ryberg.

31 records · Page 2Linked to original sources
PubMed1991

The effects of moderate protein deficiency on beta-adrenoceptor density in rat parotid and submandibular salivary glands.

The effects of moderate protein deficiency on the number and dissociation constant of beta-adrenergic receptors were investigated. One group of adult rats was fed a protein-deficient diet (5% protein), a control group was given a similar diet with 20% protein, and a third group was fed a standard pellet diet. After 21 days, the salivary glands were removed and the cell membranes were isolated. The binding of [3H]-dihydroalprenolol to cell membranes was measured, with or without the presence of timolol, a potent beta-adrenoceptor antagonist. The rats fed the 5% protein diet had fewer beta-adrenoceptors in both the parotid and the submandibular glands than did the 20% protein group, which did not differ from the standard pellet group. The dissociation constant was not affected by protein deficiency. The rats fed the 5% protein diet had a significantly lower gain in body weight, less heavy submandibular glands but heavier parotids than the rats fed 20% protein. Thus the cellular conditions for protein secretion in the salivary glands are impaired during moderate protein deficiency in the adult rat.

Animals↗
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↗
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↗
PubMed1990

Cardiovascular death after radiotherapy for benign bleeding disorders. The Radiumhemmet metropathia cohort 1912-1977.

Of 788 women treated with ionizing irradiation for benign bleeding disorders (metropathia) 308 (39%) died of cardiovascular disease. In a control group, consisting of 1219 women with metropathia who were not irradiated, 257 (21%) cardiovascular deaths occurred. Although the risk of cardiovascular death in the two studied cohorts compared with national death rates was only 0.92 (lower limit 0.82; upper limit 1.03) and 0.88 (lower limit 0.78; upper limit 0.99) respectively, it was found that women irradiated before the menopause (age 50 years) run a higher risk of cardiovascular death than the controls in the same age group and those irradiated after the menopause.

Adult↗
PubMed1990

Second primary cancer after treatment of invasive carcinoma of the uterine cervix, compared with those arising after treatment for in situ carcinomas. An effect of irradiation? A cancer registry study.

A cancer registry cohort of 16,704 cases of invasive carcinoma of the uterine cervix and 56,116 cases of in situ carcinomas of the uterine cervix was followed up and second new primary cancers were recorded. The invasive carcinomas contributed 127,118 woman-years at risk and the in situ carcinomas contributed 453,362 woman-years at risk. The main treatment for the invasive carcinomas had been radiotherapy and for the in situ carcinomas, conization and other types of surgical intervention. 767 new primaries occurred after treatment of invasive carcinoma of the uterine cervix, compared with 644.5 expected. O/E is 1.19. After the in situ carcinomas, 1,421 malignant tumors were observed, vs. 1,188.0 expected (O/E 1.19). If, however, cases of invasive carcinoma of the uterine cervix after in situ carcinomas are excluded, the ratio observed/expected is 1.10. For some sites the increased observed/expected ratios were found after both invasive and in situ carcinomas, which speaks for some common carcinogenic effect other than irradiation (for instance, in bronchus and trachea, pharynx, nose, sinus and larynx, but also in rectum, urinary bladder, other female genital organs, pancreas, lymphosarcoma, as well as acute and non-lymphatic leukemia). A lower risk than expected--after both in situ and invasive carcinoma of the uterine cervix--is observed for breast cancer, cancer of the corpus uteri and for multiple myeloma. However, analyses based on time since treatment provide evidence of a carcinogenic effect of irradiation, especially in intensively irradiated organs such as bladder, rectum, corpus uteri and ovary, and also for acute and non-lymphatic leukemia.

Adult↗
PubMed1990

Malignant disease after radiation treatment of benign gynaecological disorders. A study of a cohort of metropathia patients.

One hundred and seven cases of malignant tumours occurred among 788 women irradiated 1912 to 1977 for metropathia. One hundred and seventy-three women out of 1,219 referred for the same diagnosis and not irradiated developed a malignant tumour. The tumours were diagnosed between 1958 and 1982. The relative risk of malignant tumours among the irradiated women was 1.22 and among the non-irradiated 1.09 compared to cancer registry data. A statistically non-significant increase of the relative risk was found in the irradiated patients for tumours of the rectum (1.58), colon (1.46), and the nervous system (1.67). A decreased overall relative risk was seen for cancer of the breast (0.92) after irradiation, but women treated at the age of 50 or more had an increased risk (2.08). The relative cancer risk of the heavily irradiated sites was not increased during the first 20 years after irradiation, but a statistically significant increase of the risk was seen after 30 years.

Brachytherapy↗
PubMed1989

Effects of chronic stimulation of salivary gland beta-adrenoceptors on saliva composition and caries development in the rat.

The effects of long-term beta-adrenoceptor stimulation or inhibition on parotid and submandibular glands, saliva secretion, and caries development were studied. Groups of rats were treated daily with: 0.5 or 5 mg/kg body weight of isoproterenol (IPR), 0.5 or 5 mg/kg bw propranolol (PRO), or saline. After 42 days, saliva was collected and analyzed for secretion rate, total protein, amylase, sialic acid and electrolytes. Total protein and amylase in saliva decreased and potassium increased in the high IPR group. Phosphate increased in both IPR groups and decreased in the high PRO group. The average weight of parotid glands increased 3.7 times in the high IPR group and 1.8 times in the low IPR group. Amylase and total protein in parotid gland extracts decreased in both IPR groups. The submandibular gland weight increased 1.5 times in the high IPR group. Total protein decreased in the high IPR group. There was no difference in caries development.

Amylases↗
PubMed1989

Radiotherapy in benign uterine bleeding disorders. The Radiumhemmet metropathia cohort 1912-1977. Short and long term results.

Radiotherapy was earlier a method of choice for treatment of benign bleeding disorders (metropathia), especially in women of high surgical risk. During the period 1912 to 1977 933 women with benign bleeding disorders were treated at Radiumhemmet with intracavitary brachytherapy or external irradiation or a combination of both. The result with regard to cure of the uterine bleedings was good (48%). Hormonal withdrawal symptoms after treatment were noted in 45% of the patients. In the long term follow up an increased risk of cardiovascular death was found in women treated before menopause. Malignant tumours occurred in 107 cases versus 90.2 expected (RR 1.19). The estimated ovarian dose of ionizing radiation varied from 3.5 Gy to 6.0 Gy for the three standard techniques. Two women gave birth to a healthy child 4 and 5 years after intracavitary radium treatment. The estimated absorbed dose to the ovaries in these two women were 1 Gy and 4 Gy, respectively.

Adolescent↗
PubMed1988

Interleukin-1 affects the function of cultured human thyroid cells.

Cytokines are peptide hormones essential for cellular communication in the immune response. The purpose of this study was to investigate the influence of cytokines, especially recombinant interleukin 1 beta (rIL-1 beta), on human thyroid cells. Thyroglobulin (Tg) was measured by a double antibody radioimmunoassay, and cyclic AMP (cAMP) by a competitive protein binding assay. Supernatants from unstimulated and phytohaemagglutinin-stimulated blood mononuclear cells were added to human thyroid cells cultured in monolayers. A dose-dependent inhibition of the secretion of Tg and cAMP was demonstrated. Both subcultured and primary cultured cells incubated with rIL-1 beta at pharmacological levels (10(-1)-10(2) U/ml) exhibited an inhibition of Tg and cAMP secretion, while at physiological levels (10(-5)-10(-3) U/ml), the secretion of Tg was enhanced. The similar stimulation of cAMP was demonstrated in subcultures. These in vitro studies suggest that IL-1 beta may play a role in the pathogenesis of autoimmune thyroid diseases. Further, the stimulations at low concentrations indicate that IL-1 beta may regulate the function of the thyroid gland under physiological conditions.

Autoimmune Diseases↗
PubMed1988

Effect of long-term isoproterenol treatment on caries development in the rat using a low-cariogenic model.

Forty-eight Sprague-Dawley rats were divided into four groups. Two groups were injected daily with saline (groups 1 and 2) and two groups with isoproterenol (0.5 mg/kg body weight, groups 3 and 4) beginning at the age of 21 days. Groups 1 and 3 were each day fed nine subsequent sucrose-containing meals followed by eight starch-containing meals. Groups 2 and 4 were fed alternating sugar- or starch-containing meals, totally 17 meals per day. The animals were sacrificed after 14 weeks. At the end of the experiment, the animals in the isoproterenol groups had higher body weights. Caries development increased significantly after isoproterenol treatment. The diet regimen with alternating sugar- or starch-containing meals increased caries development, particularly in combination with isoproterenol treatment. Using low cariogenic conditions, we found that an unspecific beta-agonist (isoproterenol), given posteruptively at a low dose, enhances caries development.

Animals↗
PubMed1987

Effect of beta 2-adrenoceptor agonists on saliva proteins and dental caries in asthmatic children.

Twenty-four children, from 10 to 20 years old, with asthma treated with beta 2-adrenoceptor agonists were matched with healthy controls of the same age, sex, and social background. Stimulated whole and parotid saliva was collected, and decayed and filled tooth surfaces as well as oral hygiene habits were recorded. The dietary and sugar intake was carefully checked by a four-day dietary record. The asthmatic children had a 26% lower (p less than 0.05) value for secretion rate of whole saliva. Seventy percent of the children with Streptococcus mutans counts greater than 2 X 10(5) colony-forming units/mL of whole saliva belonged to the asthmatic group (p less than 0.05). The concentrations of total protein and amylase in parotid saliva were significantly lower for the asthmatic children. The concentrations of potassium, salivary peroxidase, bacteria-aggregating glycoproteins, and secretory IgA were not affected, but the secretion rate of parotid saliva was 36% lower in the asthma group (p less than 0.05). Oral hygiene and dietary habits did not differ between the groups. The asthmatic children had higher DFS scores, but these were not significantly different from those of the healthy controls (p = 0.07). We suggest that subjects with asthma treated with beta 2-receptor agonists should receive special prophylactic attention.

Adolescent↗