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Biomedical subjects

G Karlsson

Publications and source records attributed to G Karlsson.

At least 55 records · Page 3Linked to original sources
PubMed1998

Doctors' attitudes to fibromyalgia: a phenomenological study.

Besides specific technical skills, successful encounters with patients require an understanding of the many ways in which patients may express themselves. This qualitative study reports on the clinical experiences of doctors when meeting patients with fibromyalgia (FM). Ten strategically chosen rheumatologists and 10 GPs in central Sweden were interviewed. The interviews were taped, transcribed and analysed in accordance with the empirical, phenomenological, psychological method. The analyses indicate that doctors try to comply with the wishes and demands of patients, and at the same time avoid perceptions of personal frustration. They are inclined to be objective and to act instrumentally, apparently in order to keep in touch with what gave biomedical meaning to an otherwise incomprehensible phenomenon. The meaning structures revealed by doctors' descriptions of FM and of relating to FM patients were characterized mainly by the way in which the doctors were (i) managing their clinical uncertainty, (ii) adhering to the biomedical paradigm, (iii) prioritizing diagnostics, (iv) establishing an instrumental relationship, and (v) avoiding recognizing FM as a possible biomedical anomaly.

Adult↗
PubMed1998

Nasal nitric oxide and its relationship to nasal symptoms, smoking and nasal nitrate.

Nitric oxide (NO) is produced in the nasal mucosa and in the paranasal sinuses. Increased nasal NO concentrations have been found in patients with asthma and/or rhinitis, and nasal NO has been suggested to be a marker of nasal inflammation. Measuring the stable end products of NO, nitrate and nitrite in nasal lavage fluid have been proposed as an indirect method for measuring NO concentration. The aim of this study was to measure nasal NO concentration, and to find out its relationship to nasal nitrate concentration and clinical parameters. 73 paper-mill workers were investigated with nasal and exhaled NO, nitrate in nasal lavage fluid and were given a respiratory questionnaire. Nasal air was sampled directly from a nasal mask and NO concentration was measured with a chemiluminescence analyser. Exhaled NO was measured with the subjects breathing tidal volumes and wearing nose clips. The nitric oxide metabolites were analysed as nitrate, after reduction of nitrite to nitrate. Smokers had lower nasal NO concentration (264 ppb) as compared to NO concentrations of 340 ppb among non-smokers (p = 0.02). There was no statistically significant relationship between nasal NO concentration and nitrate in nasal lavage fluid or nasal symptoms. Nasal NO concentration was significantly related to FVC (p = 0.047) and there was a relationship with borderline statistical significance (p = 0.06) to FEV1. In conclusion, we found no relationship between nitrate in nasal lavage and nasal NO, and neither of these were correlated to nasal symptoms or to nasal PIF. Nasal NO was significantly lower among smokers. Further controlled studies on subjects with rhinitis are needed, to evaluate the relation between nasal NO and nasal inflammation. In addition, there is also a need to develop methods for measuring nasal NO that minimise contamination from sinuses.

Adult↗
PubMed1997

Two orphan seven-transmembrane segment receptors which are expressed in CD4-positive cells support simian immunodeficiency virus infection.

Clinical isolates of primate immunodeficiency viruses, including human immunodeficiency virus type 1 (HIV-1), enter target cells by sequential binding to CD4 and the chemokine receptor CCR5, a member of the seven-transmembrane receptor family. HIV-1 variants which use additional chemokine receptors are present in the central nervous system or emerge during the course of infection. Simian immunodeficiency viruses (SIV) have been shown to use CCR5 as a coreceptor, but no other receptors for these viruses have been identified. Here we show that two orphan seven-transmembrane segment receptors, gpr1 and gpr15, serve as coreceptors for SIV, and are expressed in human alveolar macrophages. The more efficient of these, gpr15, is also expressed in human CD4(+) T lymphocytes and activated rhesus macaque peripheral blood mononuclear cells. The gpr15 and gpr1 proteins lack several hallmarks of chemokine receptors, but share with CCR5 an amino-terminal motif rich in tyrosine residues. These results underscore the potential diversity of seven-transmembrane segment receptors used as entry cofactors by primate immunodeficiency viruses, and may contribute to an understanding of viral variation and pathogenesis.

Amino Acid Sequence↗
PubMed1997

Cost of illness due to dementia in Sweden.

The gross cost of illness due to dementia was estimated to be SEK30.7 billion in 1991 while the net cost was estimated to be SEK20 billion. The sensitivity analysis showed a variation between SEK20 billion and SEK36 billion in 1991.

Aged↗
PubMed1997

Costs and effects of microsurgery versus radiosurgery in treating acoustic neuroma.

This study analyses costs and effects of treating acoustic neuroma patients by using microsurgery compared to radiosurgery. Radiosurgery is the stereotactic application of radiotherapy and an innovative medical technology. Cost and effect estimates of conventional treatment were based on a retrospective study in the Netherlands. Similar data for a comparable group of patients in Sweden were collected for radiosurgery, as this treatment option is currently not available in the Netherlands. Fifty-three acoustic neuroma patients who had been operated on the University Hospital Rotterdam between November 1990 and February 1995 were included. This group was compared with 92 acoustic neuroma patients treated with radiosurgery (Gamma Knife. Stockholm, Sweden) in the same period. Data on health care use were collected from patient files. To obtain data on production losses and quality of life, a questionnaire was sent by mail in February 1995. This booklet consisted of the Health and Labour-questionnaire (HLQ), the Short Form-36 (SF36) and the EuroQol. The response rate was 92%. Direct costs for microsurgery amounted to Dfl. 20.072,- and for radiosurgery to Dfl. 14.272,-. Indirect costs were respectively Dfl. 16.400,- and Dfl. 1.020,-. General health rating was better for radiosurgery than for microsurgery. On the whole, differences in clinical outcomes between the two patient groups were small. Assuming a reasonable occupancy rate of the expensive radiosurgery equipment, we demonstrated that for the short term treating patients with acoustic neuroma with an extra-meatal tumour diameter of less than 3 centimeters, radiosurgery is more cost-effective than microsurgery.

Adult↗
PubMed1997

Effect of polyethyleneglycol-phospholipids on aggregate structure in preparations of small unilamellar liposomes.

Phospholipids with covalently attached poly(ethylene glycol) (PEG lipids) are commonly used for the preparation of long circulating liposomes. Although it is well known that lipid/PEG-lipid mixed micelles may form above a certain critical concentration of PEG-lipid, little is known about the effects of PEG-lipids on liposome structure and leakage at submicellar concentrations. In this study we have used cryogenic transmission electron microscopy to investigate the effect of PEG(2000)-PE on aggregate structure in preparations of liposomes with different membrane compositions. The results reveal a number of important aggregate structures not documented before. The micrographs show that enclosure of PEG-PE induces the formation of open bilayer discs at concentrations well below those where mixed micelles begin to form. The maximum concentration of PEG-lipid that may be incorporated without alteration of the liposome structure depends on the phospholipid chain length, whereas phospholipid saturation or the presence of cholesterol has little or no effect. The presence of cholesterol does, however, affect the shape of the mixed micelles formed at high concentrations of PEG-lipid. Threadlike micelles form in the absence of cholesterol but adapt a globular shape when cholesterol is present.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1997

Morphological changes induced by phospholipase C and by sphingomyelinase on large unilamellar vesicles: a cryo-transmission electron microscopy study of liposome fusion.

Cryo-transmission electron microscopy has been applied to the study of the changes induced by phospholipase C on large unilamellar vesicles containing phosphatidylcholine, as well as to the action of sphingomyelinase on vesicles containing sphingomyelin. In both cases vesicle aggregation occurs as the earliest detectable phenomenon; later, each system behaves differently. Phospholipase C induces vesicle fusion through an intermediate consisting of aggregated and closely packed vesicles (the "honeycomb structure") that finally transforms into large spherical vesicles. The same honeycomb structure is also observed in the absence of enzyme when diacylglycerols are mixed with the other lipids in organic solution, before hydration. In this case the sample then evolves toward a cubic phase. The fact that the same honeycomb intermediate can lead to vesicle fusion (with enzyme-generated diacylglycerol) or to a cubic phase (when diacylglycerol is premixed with the lipids) is taken in support of the hypothesis according to which a highly curved lipid structure ("stalk") would act as a structural intermediate in membrane fusion. Sphingomyelinase produces complete leakage of vesicle aqueous contents and an increase in size of about one-third of the vesicles. A mechanism of vesicle opening and reassembling is proposed in this case.

Biophysical Phenomena↗
PubMed1997

The friction cost method: a comment.

The friction cost method has been proposed as an alternative to the human-capital approach of estimating indirect costs. We argue that the friction cost method is based on implausible assumptions not supported by neoclassical economic theory. Furthermore consistently applying the friction cost method would mean that the method should also be applied in the estimation of direct costs, which would mean that the costs of health care programmes are substantially decreased. It is concluded that the friction cost method does not seem to be a useful alternative to the human-capital approach in the estimation of indirect costs.

Absenteeism↗
PubMed1997

Analytical extraction of regulatory peptides from rat lung tissue.

We evaluated protocols for the extraction of calcitonin gene-related peptide, neuropeptide Y, substance P, peptide YY and beta-endorphin from rat lung tissue for subsequent radioimmunoassay. The effects of varying acidity of the extraction solution and repeating extraction on the recovery of peptide immunoreactivity and non-specific tracer-binding were compared by analysis of variance. Moreover, variability of immunoreactivity was quantified for comparison. Considering all three criteria, the optimal acidity for extraction was: 0.1 M or 1 M acetic acid for CGRP and beta-endorphin, 0.1 M acetic acid for NPY, 1 M acetic acid for substance P and phosphate buffer for peptide YY. Double or combined extraction unambiguously improved assay results only for substance P. Reversed-phase high-performance liquid chromatography of CGRP-, NPY- and SP-immunoreactivity obtained from selected extracts suggested that differences in recovery of these peptides are not explainable by differential peptide fragmentation during extraction.

Animals↗
PubMed1997

Fluticasone propionate aqueous nasal spray in the treatment of nasal polyposis.

BACKGROUND: Topical glucocorticoids are the medical treatment of choice in a majority of patients suffering from nasal polyposis. Fluticasone propionate is a fluorinated steroid reported to be highly effective when used topically in the nose for seasonal and perennial allergic and nonallergic rhinitis. OBJECTIVES: To evaluate the efficacy and tolerability of intranasal fluticasone propionate in the treatment of long-standing polyposis. METHODS: Fifty-five patients with long-standing nasal polyposis were treated over a 26-week period with fluticasone propionate aqueous nasal spray 200 micrograms bid, beclomethasone dipropionate aqueous nasal spray 200 micrograms bid or placebo, administered intranasally in an aqueous spray in a double-blind, placebo-controlled parallel-group design at a single center. The primary efficacy endpoint was the physicians' assessment of symptoms and polyp score. Peak nasal inspiratory flow was performed twice daily and on every visit to evaluate the effect of the corticosteroids on nasal air flow. RESULTS: A significant difference in the primary efficacy endpoint between fluticasone propionate aqueous nasal spray and beclomethasone dipropionate aqueous nasal spray compared with placebo was seen after 14 weeks of treatment. This was further verified by the peak nasal inspiratory flow results. There was some evidence of earlier onset in the fluticasone propionate aqueous nasal spray group compared with the beclomethasone dipropionate aqueous nasal spray group after 4 weeks in terms of the primary efficacy endpoint. From the daily record cards patients receiving fluticasone propionate aqueous nasal spray had a significantly higher percentage of days on which they required no rescue medication (P < .009) and a higher percentage of days with an overall nasal blockage score on waking of < 2 (P < .013) when compared with placebo-treated patients. No other statistically significant results were found between the two active compounds. CONCLUSION: Fluticasone propionate aqueous nasal spray 200 micrograms bid and beclomethasone dipropionate aqueous nasal spray 200 micrograms bid are effective in treating the symptoms of nasal polyps, with some evidence that fluticasone propionate aqueous nasal spray has a faster onset of action and is tolerated at least as well as beclomethasone dipropionate aqueous nasal spray at the same dose.

Administration, Intranasal↗
PubMed1997

The cost-effectiveness of routine postoperative radiotherapy after sector resection and axillary dissection for breast cancer stage I. Results from a randomized trial.

BACKGROUND: Cost-effectiveness of routine postoperative radiotherapy after breast-conserving surgery has not been prospectively evaluated earlier. In times of rationing of medical resources, valid assessments of cost-effectiveness are important for rational allocation of resources. PURPOSE: Cost and cost-effectiveness of routine postoperative radiotherapy was calculated in a prospective randomized trial comparing sector resection plus axillary dissection with (XRT group) or without (non-XRT group) postoperative radiotherapy in breast cancer stage I. Three hundred eighty-one patients were included. After a median follow-up of five years 43 local recurrences, six of them in the XRT-group occurred (P < 0.0001). No difference in regional and distant recurrence (P = 0.23) or survival (P = 0.44) was observed. PATIENTS AND METHODS: Direct medical costs as well as indirect costs in terms of production lost during the treatment period and travel expenses were estimated from data in the medical records and the national insurance registry of each patient. Average costs of different treatment activities and measures were estimated for the XRT-group and the non-XRT group respectively. From these estimates differences in costs and effectiveness between the groups were calculated and marginal cost-effectiveness ratios were estimated. For the construction of QALYs each life-year was quality-adjusted by a utility value depending on which health state the patient was considered to perceive. RESULTS: Taking into account the cost of primary treatment, the cost of follow-up, the cost of treatment of a local recurrence, travel expenses and indirect costs (production lost) excluding costs for treatment of regional and distant recurrence the cost per avoided local recurrence at five years was SEK 337,727 ($44,438, Pounds 27,018). Adjustment for quality of life showed a cost for every gained QALY to be SEK approximately 1.6 million, ($210,526, Pounds 128,000), range SEK 0.2-3.9 million ($26,315-513,158, Pounds 16,000-312,000). CONCLUSION: The cost of routine postoperative radiotherapy after sector resection and axillary dissection in breast cancer stage I per avoided local recurrence and gained QALY is high. The cost per gained QALY show great variation depending on utility value, which in this study was derived from external observers and not from the patients themselves. These results stress the importance of identifying risk factors for local recurrence, better understanding of impact on quality of life of a local recurrence and adding cost evaluations to clinical trials in early breast cancer.

Breast Neoplasms↗
PubMed1997

A study of some current methods for assessment of nasal histamine reactivity.

The aim of this study was to investigate the reactivity of the nasal mucosa of patients with pollen allergy compared to healthy controls, when challenged with histamine outside the pollen season. Assessments were made with symptom score, acoustic rhinometry, nasal peak expiratory and inspiratory flow (NPEF and NPIF) and rhinomanometry in order to find the most sensitive method for the purpose. Twenty-one patients with seasonal allergic rhinitis and 20 healthy controls were challenged with histamine dihydrochloride in increasing concentrations (0.01, 0.1, 1.0 mg/ml) locally in the nose. Our results show no difference in mucosal reactivity between the patients and controls regardless of the method used. When comparing the methods we find that NPIF and NPEF are more sensitive to mucosal changes than the other methods we have studied.

Adult↗
PubMed1997

Long-term economic effects of team-based clinical case management of patients with chronic minor disease and long-term absence from working life.

OBJECTIVES: To examine the socio-economic effects of team-based clinical case management of patients with chronic minor disease bound for early retirement. DESIGN: Marginal analysis of programme costs and benefits to society compared with no-programme baseline of costs occurring in society due to productivity loss. Prospective patient data collection on admission, discharge, and at one year and five years after discharge to determine programme effectiveness. SETTING: Out-patient clinic at the department of social medicine in tertiary care hospital. SUBJECTS: 239 patients with minor disease and long-term vocational absence consecutively admitted to the study. At the one-year evaluation, 17 patients had been readmitted to the team, 7 could not be found, 6 declined the interview and 2 were deceased. At the five-year evaluation of 49 patients who were active after one year, one was deceased and 10 were unable to be found. MAIN OUTCOME MEASURES: Vocational activity. Programme costs. Benefits to society measured by decrease in indirect costs. RESULTS: The one-year vocational rehabilitation rate from the program was 20.5% and the five-year rehabilitation rate was 11.3%. The total discounted cost for case management of the 239 patients was 7.3 MSEK (600,000 Pounds). The decrease in the indirect costs to society from the 28 patients found active after five years was 35.1 MSEK (2,500,000 Pounds). The net present value of the programme at the 1991 price level was 27.5 MSEK (2,365,000 Pounds). CONCLUSIONS: Tertiary care level team-based clinical case management for vocational rehabilitation of patients with chronic minor disease has a positive cost-benefit ratio. A cross-boundary awareness at a health policy level is needed of the societal costs involved for this group of patients who fall between the traditional services in health care and social work.

Absenteeism↗
PubMed1997

A longitudinal study of social, psychological and behavioural factors associated with drunken driving and public drunkenness.

Studies on psychosocial conditions in drunken drivers have generally been cross-sectional and based on rather small selected samples. The objective of this study was to analyse, in a longitudinal perspective, the relationship, in young males, between social and psychological factors and indicators of alcohol abuse on one hand and the risk of subsequent drunken driving and public drunkenness on the other hand, in order to identify similarities and differences in risk factor patterns. Questionnaire information from 8122 military conscripts in 1969/70 was linked to data on drunken driving and public drunkenness for 495 males with offences registered up to 1977. Logistic regression analysis showed that the relative risk (RR) for high alcohol consumption, smoking, use of narcotics and sniffing of solvents had a statistically significant association to subsequent drunken driving and public drunkenness in univariate analyses. In multivariate logistic analyses, RR remained increased for those with fathers belonging to social class II and especially so for those coming from social class III. Smoking (RR 3.3, with a 95% confidence interval of 1.6-6.8) was significantly increased in drunken drivers with a blood alcohol concentration (BAC) of 0.15% or more at apprehension, as was truancy or contact with police or juvenile authorities in drunken drivers with a BAC of 0.05-0.15%, and illicit drug use, intoxication drinking, contact with police or juvenile authorities and hangover with public drunkenness. Thus, we found that early social and behavioural factors, substance abuse and risky use of alcohol were predictors for both drunken driving and public drunkenness, with no marked differences in risk factor patterns.

Adolescent↗
PubMed1997

Treatment of Alzheimer disease with tacrine: a cost-analysis model.

In a cost-analysis model, the effect on the costs of Alzheimer disease of tacrine (tetrahydroaminoacridine) treatment was studied. A model of the survival of the Swedish Alzheimer disease population was constructed in which the placement of patients with Alzheimer disease in care organization was assumed to be influenced by the use of tacrine. Based on this model, the cost analysis was performed. Fifty-two percent of the Alzheimer disease population with an initial Mini-Mental State Examination (MMSE) score of 10 to 24 points are in the main alternative of the model treated with 160 mg tacrine with an initial improvement in MMSE of 2.6 points. The benefit of tacrine was a cost reduction of 1.3% when the results were calculated for the entire Alzheimer disease population. This corresponds to a benefit of 1.3 billion Swedish kronor (SEK) (with 3% discount rate) for the entire estimated survival period. The annual benefit per patient was estimated as 2,900 SEK [approximately U.S. $320 (1993)]. In the sensitivity analysis, the range was between -0.6% and 5.2%. Beginning treatment in the early stages of Alzheimer disease results in lower costs than a later start. The main conclusion is that tacrine, according to the model, has beneficial but modest effects on the costs of Alzheimer disease in Sweden.

Alzheimer Disease↗