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Biomedical subjects

M Ryberg

Publications and source records attributed to M Ryberg.

At least 19 recordsLinked to original sources
PubMed2001

A cognitive-behavioral group intervention as prevention for persistent neck and back pain in a non-patient population: a randomized controlled trial.

Given the demand for interventions that may prevent the development of persistent musculoskeletal pain problems, we investigated the effects of a cognitive-behavioral program in a group of non-patients with neck or back pain symptoms. Two hundred and fifty-three people selected from a population study were invited to participate. These people had experienced four or more episodes of relatively intense spinal pain during the past year but had not been out of work more than 30 days. Participants were randomly assigned to either a cognitive-behavioral group intervention or a treatment as usual comparison group. The experimental group received a standardized six-session program, provided by a trained therapist according to a manual. A significant overall analysis at the 1-year follow-up showed that the cognitive-behavioral group produced better results on 26 of the 33 outcome variables. Group comparisons indicated that the cognitive-behavioral group, relative to the comparison group, had significantly better results with regard to fear-avoidance beliefs, number of pain-free days, as well as the key variable of sick leave. Participation in the cognitive behavioral group reduced the risk for long-term sick leave during the follow-up by threefold. Thus, despite the strong natural recovery rate for back pain, the cognitive-behavioral intervention produced a significant preventive effect with regard to disability.

Adult↗
PubMed2001

Altered etioplast development in phytochrome chromophore-deficient mutants.

Inhibition of chromophore synthesis in the phytochrome-deficient aurea (au) and yellow-green-2 (yg-2) mutants of tomato (Solanum lycopersicum L.) results in a severe reduction of protochlorophyllide (Pchlide) accumulation in dark-grown hypocotyls. Experiments with apophytochrome-deficient mutants indicate that the inhibition of Pchlide accumulation results from two separate effects: one dependent on the activity of phytochromes A and B1 and one phytochrome-independent effect that is attributed to a feedback inhibition of the tetrapyrrole biosynthesis pathway. Cotyledons only show phytochrome-independent inhibition of Pchlide synthesis. Analysis of NADPH:protochlorophyllide oxidoreductase levels by western blotting showed that the reduction in Pchlide in au and yg-2 is accompanied by a correlative, but less substantial, decrease in NADPH:protochlorophyllide oxidoreductase. Consistent with this result, in vivo fluorescence spectra demonstrate that both mutants are primarily deficient in non-phototransformable Pchlide. Analysis of etioplast structure indicates that plastid development in au and yg-2 is retarded in hypocotyls and partially impaired in cotyledons, again correlating with the reduction in Pchlide. Since Pchlide synthesis is also reduced in chromophore-deficient mutants of pea (Pisum sativum L.) and Arabidopsis thaliana (L.) Heynh. (Landsberg erecta) these results may be significant for explaining aspects of the phenotype of this mutant class that are independent of the loss of phytochrome.

Arabidopsis↗
PubMed2001

Prognostic factors and long-term survival in 585 patients with metastatic breast cancer treated with epirubicin-based chemotherapy.

BACKGROUND: Analysis of prognostic factors in patients with metastatic breast cancer treated with epirubicin-based chemotherapy. PATIENTS AND METHODS: Data from 469 patients treated with epirubicin-based chemotherapy for metastatic breast cancer were used. Prognostic factors were identified (Cox multivariate analysis). A prognostic index was compiled and risk groups were established accordingly. The applicability of the index was investigated in a series of 116 patients. RESULTS: The prognostic factors identified were: liver, pleural, soft tissue, lung and bone metastases, performance status > 2, advancing age, abnormal elevation of serum lactate dehydrogenase and negative/unknown oestrogen receptor status. Four risk groups were established: good, intermediate I, intermediate II and poor. The median and five-year survivals in percentage were: good: 34 months (26%); intermediate I: 19 months (6%), intermediate II: 12 months (0%); poor: 7 months (1%). The corresponding values in the applicability group were: 32 months (23%); 28 months (22%); 18 months (5%); and 6 months (0%). CONCLUSIONS: It is more the number and impact on the organs involved, that predict the patients' survival. The construction of a prognostic index could be helpful in assessing the outlook for patients, especially the quite dramatic difference in long-term survival between the good and poor risk patients.

Adult↗
PubMed2001

The association of bacterial adhesion with dental caries.

Saliva adhesion of bacteria is a key event in oral biofilm formation. Here, we used partial least-squares (PLS) analysis to correlate adhesion of cariogenic (Streptococcus mutans Ingbritt) and commensal (Actinomyces naeslundii LY7) model bacteria, and their agglutinin and acidic proline-rich protein ligands, respectively, with high and low caries experiences in 38 children reflecting today's skewed caries distribution. Adhesion of S. mutans was among the factors correlating strongest with high caries experience when PLS modeled together with traditional factors (e.g., sugar intake, lactobacilli counts). Saliva phenotypes with high agglutinin levels and Db-s (an acidic PRP variant) coincided with both high caries experience and S. mutans adhesion. A. naeslundii adhesion correlated with low caries experience. Non-Db phenotypes (i.e., acidic PRP-1 and PRP-2 variants) coincided with both low caries experience and S. mutans, but high A. naeslundii, adhesion. Thus, bacterial adhesion may modulate susceptibility and resistance to dental caries.

Actinomyces↗
PubMed2000

ADP/ATP and protein phosphorylation dependence of phototransformable protochlorophyllide in isolated etioplast membranes.

The effects of modulated ADP/ATP and NADPH/NADP(+) ratios, and of protein kinase inhibitors, on the in vitro reformation of phototransformable protochlorophyllide, i.e. the aggregated ternary complexes between NADPH, protochlorophyllide, and NADPH-protochlorophyllide oxidoreductase (POR, EC 1.3.1.33), in etioplast membranes isolated from dark-grown wheat (Triticum aestivum) were investigated. Low temperature fluorescence emission spectra (-196 degrees C) were used to determine the state of the pigments. The presence of spectral intermediates of protochlorophyllide and the reformation of phototransformable protochlorophyllide were reduced at high ATP, but favoured by high ADP. Increased ADP level partly prevented the chlorophyllide blue-shift. The protein kinase inhibitor K252a prevented reformation of phototransformable protochlorophyllide without showing any effect on the chlorophyllide blue-shift. Addition of NADPH did not overcome the inhibition. The results indicate that protein phosphorylation plays a role in the conversion of the non-phototransformable protochlorophyllide to POR-associated phototransformable protochlorophyllide. The possible presence of a plastid ADP-dependent kinase, the activity of which favours the formation of PLBs, is discussed. Reversible protein phosphorylation is suggested as a regulatory mechanism in the prolamellar body formation and its light-dependent dispersal by affecting the membrane association of POR. By the presence of a high concentration of phototransformable protochlorophyllide, prolamellar bodies can act as light sensors for plastid development. The modulation of plastid protein kinase and protein phosphatase activities by the NADPH/NADP(+) ratio is suggested.

Journal Article↗
PubMed2000

Do epidemiological results replicate? The prevalence and health-economic consequences of neck and back pain in the general population.

Current estimates of the prevalence and consequences of neck and back pain vary greatly between studies. It is not known whether this variance is due to differences in methodology, or if it depends on the dynamics of the problem over time. The aim of this study was consequently an attempt to replicate and extend the findings of a previous epidemiological study using the same methodology on a new population. A survey of 3000 35-45 year olds, selected at randon, was conducted to determine the prevalence, site, frequency and intensity of the pain as well as any work loss or health-care utilization. The response rate was 69% and an analysis of non-responders showed that they were very similar to responders, but had a slightly lower prevalence. The results replicated the original study: 73% reported back pain during the past year and the consequences included considerable suffering and functional impairment. Moreover, 17% of those reporting pain had utilized sick leave during the past year for the problem, while an additional 14% had been off work but had not used sick leave. Sufferers averaged 3.5 health-care visits during the past year. However, the consumption of resources was highly skewed and about 6% of the sufferers accounted for over 50% of the costs. It was concluded that when the same selection criteria and assessment techniques are employed, the results found are quite similar. This implies that much of the huge variation in reported prevalence rates and consequences of back pain may be due to methodological differences. This underscores the need for standardized methods.

Adult↗
PubMed2000

Possible release of an ArgGlyArgProGln pentapeptide with innate immunity properties from acidic proline-rich proteins by proteolytic activity in commensal streptococcus and actinomyces species.

This study suggests degradation of salivary acidic proline-rich proteins (PRPs) into potential innate-immunity-like peptides by oral Streptococcus and Actinomyces species. PRP degradation paralleled cleavage of Pro-containing substrates. PRP degradation by S. gordonii strain SK12 instantly released a Pyr(1)-Pro(104)Pro(105) and a Gly(111)-Pro(149)Gln(150) peptide together with a presumed Arg(106)Gly(107)Arg(108)Pro(109)Gln(110) pentapeptide. The synthetic Arg(106)Gly(107)Arg(108)Pro(109)Gln(110) peptide desorbed bound bacteria and counteracted sucrose-induced decrease of dental plaque pH in vitro.

Actinomyces↗
PubMed1998

Analysis of postoperative vaginal vault radiotherapy of stage I endometrial cancer with different radionuclides.

A total of 213 patients in stage I grade 1 endometrial cancer were treated postoperatively with either radium or caesium vaginal applicators. The rate of complication and the incidence of second malignancies were studied in both groups. The frequency of grades 2 and 3 vaginal complications was higher among patients treated with caesium applicators but not statistically significant. The observed number of second malignancies was significantly higher than expected in the radium-treated group, in which the observed number of second malignancies with distant location was also significantly higher than expected, which could not be found in the caesium group.

Adult↗
PubMed1998

Epirubicin cardiotoxicity: an analysis of 469 patients with metastatic breast cancer.

PURPOSE: To evaluate the influence of cumulative dose, dose-intensity, single-dose level, and schedule of epirubicin on the risk of developing congestive heart failure (CHF) in patients with advanced breast cancer. PATIENTS AND METHODS: Four hundred sixty-nine consecutive anthracyline-naive patients with metastatic breast cancer were included. Only patients with cardiac failure according to New York Heart Association (NYHA) function class II or more were recorded as having CHF. For each patient, the following were calculated: the cumulative dose of epirubicin, mean dose-intensity (cumulative dose of epirubicin/duration of treatment), and single-dose level (cumulative dose of epirubicin/number of injections). RESULTS: Thirty-four patients (7.2%) developed CHF. The cumulative risk of cardiotoxicity was 4% at 900 mg/m2 and increased exponentially to 15% at 1,000 mg/m2. Irradiation against the mediastinum and thoracic spine increased the risk of CHF (P=.025), but dose-intensity, single-dose level, and schedule had no influence on the risk of developing CHF. Age, previous adjuvant irradiation (to the left or right hemithorax), and previous chemotherapy (cyclophosphamide, methotrexate, and fluorouracil [CMF]) were not risk factors. The median time to onset of CHF following the last dose of epirubicin was 57 days (range, 0 to 853). Among patients with CHF, 13 (38.2%) died of cardiac failure. The median survival time for all patients with CHF was 162 days (range, 0 to +1,957). Previous irradiation directly against the heart increased the risk of death due to cardiac failure and decreased the median survival time to 125 days (range, 0 to 336). CONCLUSION: The present large retrospective study of 469 patients substantiates previous results concerning the cardiotoxicity of epirubicin. A significantly increasing risk of CHF in patients who receive cumulative doses greater than 950 mg/m2 was established. The future recommended maximum cumulative dose of epirubicin should be 900 mg/m2 in patients with metastatic breast cancer. Previous irradiation against the heart leads to an increased risk of developing CHF with an accelerated course to death, which indicates an additive cardiotoxic effect of irradiation and epirubicin.

Adult↗
PubMed1996

Doxorubicin-melphalan with and without cisplatin in advanced ovarian cancer--ten-year survival results from a prospective randomized study by the Swedish Cooperative Ovarian Cancer Study Group.

In a controlled prospective randomized study the regimen doxorubicin (A) 40 mg/m2 + melphalan (M) 0.4 mg/kg was compared with A + M + cisplatin (C) 50 mg/m2 given every four weeks in advanced ovarian cancer, FIGO stage III or IV and with serous or anaplastic histology. From 1981 to 1983, 300 patients entered the study and 295 patients were evaluable for response, toxicity and long-term survival. All patients were followed for at least 10 years. The majority of patients had large residual tumours >2 cm. Patients treated with MAC had a higher response rate compared with patients treated with MA (76% vs. 50%, p < 0.01) and treatment with MAC resulted in significantly more pathological complete responders than MA. There was a significant difference in median duration of response (19 months vs. 13 months, p < 0.006) and in median survival time (26 months vs. 19 months, p = 0.05). After 5- and 10 years a significant difference in progression-free and overall survival was found. The independent prognostic factors in this study were residual tumour after primary surgery, treatment with MAC, tumour grade, ascites, and stage. Objective and subjective side effects were significantly worse with MAC, although tolerable. In conclusion, this study shows that incorporating C into MA improves the duration of progression-free survival and overall survival in women with incompletely resected Stage III or Stage IV ovarian epithelial cancer. A 5- and 10-year survival of 25% and 18%, respectively, is impressive.

Adolescent↗
PubMed1995

Photoreduction of zinc protopheophorbide b with NADPH-protochlorophyllide oxidoreductase from etiolated wheat (Triticum aestivum L.).

A preparation of prolamellar bodies from wheat etioplasts was used as a source for NADPH-protochlorophyllide oxidoreductase (pchlide reductase). The enzyme was solubilized with Triton X-100 after reduction of the endogenous photoconvertible protochlorophyllide a to chlorophyllide a by saturating illumination. Protochlorophylls a and b, protochlorophyllide a and zinc protopheophorbide b were added to the soluble enzyme preparation to determine if they were reduced in the dark or in the light. None of the compounds were reduced (with NADPH) in the dark; however, light-dependent reduction was demonstrated with protochlorophyllide a and zinc protopheophorbide b. The yield was approximately 50% for both substrates. Photoreduction did not occur with the esterified protochlorophylls a and b. Photoreduction of zinc protopheophorbide b, the zinc analogue of protochlorophyllide b, is the first demonstration of the reduction of a chlorophyll-b-related compound by pchlide reductase.

Chlorophyll↗
PubMed1995

The effects of long-term treatment with salmeterol and salbutamol on the flow rate and composition of whole saliva in the rat.

The effect of long-acting beta 2-adrenoceptor agonists on salivary glands and saliva secretion has not been studied before. Sprague-Dawley rats were given either the long-acting beta 2-agonist salmeterol, 1 mg/kg body wt per day or the short-acting agonist salbutamol, 5 mg/kg per day. Saline solution was used as control. After 18 days pilocarpine-stimulated saliva was collected, and after 21 days saliva was collected after stimulation with isoproterol and pilocarpine in combination. The saliva was analysed for total protein, amylase, hexosamine, sialic acid, sodium, potassium and calcium. At day 25 the salivary glands were extirpated and weighed. The weight of the parotid glands increased significantly after both salmeterol and salbutamol treatment, approx. 40%; the submandibular gland weights were not affected by either beta 2-agonist treatment. Pilocarpine-stimulated salivary flow rate was increased in the salbutamol, but not in the salmeterol, group. In the salmeterol group the concentration of sialic acid was increased and that of calcium was decreased. In saliva stimulated with pilocarpine and isoproterenol in combination, the concentrations of total protein, amylase and calcium were decreased after salmeterol. In the salbutamol group, total protein and potassium were decreased. The ratio sialic acid: total protein was increased at both saliva collections in both beta 2-agonist groups. It is concluded that rats treated chronically with the long-acting beta 2-adrenoceptor agonist salmeterol have an impaired secretion of salivary proteins and calcium and that the effect resembles that of salbutamol.

Adrenergic beta-Agonists↗
PubMed1992

Structure of RecA-DNA complexes studied by combination of linear dichroism and small-angle neutron scattering measurements on flow-oriented samples.

By combining anisotropy of small-angle neutron scattering (SANS) and optical anisotropy (linear dichroism, l.d.) on flow-oriented RecA-DNA complexes, the average DNA-base orientation has been determined in RecA complexes with double-stranded (ds) as well as single-stranded (ss) DNA. From the anisotropy of the two-dimensional SANS intensity representation, the second moment orientation function S is obtained. Knowledge of S is crucial for the interpretation of l.d. spectra in terms of orientation of the DNA bases and the aromatic amino acid residues. The DNA-base planes are essentially perpendicular to the fibre axis of the complex between RecA and dsDNA in the presence of cofactor ATP gamma S. A somewhat tilted base geometry is found for the RecA-ATP gamma S complexes with single-stranded poly(dT) and poly(d epsilon A). This behaviour contrasts the RecA-ssDNA complex formed without cofactor which displays a poor orientation of the bases. Well-ordered bases in the ssDNA-RecA complex is possibly reflecting the role of RecA in preparing a nucleotide strand for base-pairing in the search-for-homology process. While the central SANS intensity is essentially independent of the pitch of the helical complex, a secondary intensity maximum, which becomes focused upon flow orientation, is found to be a sensitive measure of the pitch. The pitch values for the complexes compare well with cryo-electron microscopy results but are slightly larger than those seen for uranyl-stained samples.

Adenosine Triphosphate↗
PubMed1992

Salivary hypofunction in patients with familial amyloidotic polyneuropathy.

Patients who suffer from familial amyloidotic polyneuropathy frequently complain of mouth dryness and an increased need for dental treatment. The aim of the present investigation was to study saliva secretion rate and composition and other factors related to the risk of dental caries in patients with familial amyloidotic polyneuropathy. Thirty patients with familial amyloidotic polyneuropathy volunteered for the study and were compared with a matched control group. Samples of unstimulated and stimulated whole saliva were collected in a standardized manner. The secretion rates were calculated, and the concentrations of electrolytes, glycoprotein markers, and proteins with antibacterial properties were analyzed. Dental caries and variables related to the risk of dental caries were also scored. The results show that familial amyloidotic polyneuropathy patients frequently have a decreased rate of saliva secretion and that the degree of salivary hypofunction is positively correlated to the progress of familial amyloidotic polyneuropathy. Forty-three percent of the familial amyloidotic polyneuropathy patients in this study had no detectable secretion of unstimulated saliva. A low secretion rate of stimulated saliva (< 0.7 ml/min) was found in 33% of the patients. The concentrations of salivary protein, amylase, lysozyme, salivary peroxidase, secretory IgA, hexosamines, sialic acid, fucose, phosphate, potassium, and the degree of protein glycosylation were higher in the familial amyloidotic polyneuropathy patients than in the control patients. We conclude that patients with familial amyloidotic polyneuropathy have a reduced saliva secretion and are subsequently at risk for increased development of dental caries.

Adult↗
PubMed1992

The Shibata Shift and the Transformation of Etioplasts to Chloroplasts in Wheat with Clomazone (FMC 57020) and Amiprophos-Methyl (Tokunol M).

The Shibata shift is a change in the absorption maximum of chlorophyllide from 684 to 672 nanometers that occurs within approximately 0.5 hour of phototransformation of protochlorophyllide to chlorophyllide. Two compounds, clomazone and amiprophos-methyl, which previously have been shown to inhibit the Shibata shift in vivo, were used to look for correlations between the Shibata shift and other processes that occur during etioplast to chloroplast transformation. Leaf sections from 6-day-old etiolated wheat seedlings (Triticum aestivum L. cv Walde) were treated with 0.5 millimolar clomazone or 0.1 millimolar amiprophos-methyl in darkness. In addition to the Shibata shift, the esterification of chlorophyllide to chlorophyll and the relocation of protochlorophyllide reductase from the prolamellar bodies to the developing thylakoids were inhibited by these treatments. Prolamellar body transformation did not appear to be affected by amiprophos-methyl and was only slightly affected by clomazone. The results indicate that: (a) there is a strong correlation between the occurrence of the Shibata shift and esterification activity; (b) transformation of the prolamellar bodies does not depend on the Shibata shift; and (c) the occurrence of the Shibata shift may be a prerequisite to the relocation of protochlorophyllide reductase from prolamellar bodies to thylakoids.

Journal Article↗
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↗