| 1. |
- Forsström, J. J., et al.
(författare)
-
Using data preprocessing and single layer perceptron to analyze laboratory data
- 1995
-
Ingår i: Scandinavian Journal of Clinical and Laboratory Investigation. - : Informa Healthcare. - 0036-5513 .- 1502-7686. ; 55:s222, s. 75-81
-
Tidskriftsartikel (refereegranskat)abstract
- During daily work in hospitals a large amount of clinical data is produced each day. Totally computerized patient records are not yet widely used but a large part of essential information is already stored on computer files. These include laboratory test results, diagnoses, codes for operations, codes of histopathological diagnoses and maybe even the patient's medication. Accordingly, these databases include much clinical knowledge that would be useful for clinicians.Laboratories try to support clinicians by producing reference values for laboratory tests. It is, of course, necessary information but, however, it does not give very much information about the weight of evidence that an abnormal laboratory test will give in special clinical settings.We have developed a software package - DiagaiD - in order to build a smart link between patient databases and clinicians. It utilizes neural network-based machine learning techniques and can produce decision support which meets the special needs of clinicians. From example cases it can learn clinically relevant transformations from original numeric values to logical values. By using data transformation together with a single layer perceptron it is possible to build nonlinear models from a set of preclassified example cases.In this paper, we use two small datasets to show how this scheme works in the diagnosis of acute appendicitis and in the diagnosis of myocardial infarction. Results are compared with those obtained using logistic regression or backpropagation neural networks. The performance of our neuro-fuzzy tool seemed to be slightly better in these two materials but the differences did not reach statistical significance.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Andersson, Peter, et al.
(författare)
-
Low symptomatic load in Crohn's disease with surgery and medicine as complementary treatments
- 1998
-
Ingår i: Scandinavian Journal of Gastroenterology. - : Informa Healthcare. - 0036-5521 .- 1502-7708. ; 33:4, s. 423-429
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The treatment of Crohn's disease has changed owing to the recognition of its chronicity. Medical maintenance treatment and limited resections have evolved as major concepts of management, regarded as complementary, and both aim at reducing the symptoms.Methods: We investigated the symptomatic load in Crohn's disease as reflected in a cross-sectional study of the symptom index, physicians' assessment, and the patients' perception of health. A cohort of 212 patients from the primary catchment area and 125 referred patients were studied.Results: Of catchment area patients, 83% were receiving medication, and the annual rate of abdominal surgery was 5.7%. Corresponding figures for the referred patients were 82% and 10.3%. According to the symptom index, 87% of catchment area patients were in remission or had only mild symptoms; according to the physicians' assessment, 90% were. The patients' median perception of health was 90% of perfect health according to the visual analogue scale. The figures were similar for referred patients, except that referrals were considered more diseased by the physician.Conclusion: The great majority of patients with Crohn's disease are able to live in remission or experience only mild symptoms.
|
|
| 5. |
- Collingwood, T N, et al.
(författare)
-
A natural transactivation mutation in the thyroid hormone beta receptor: impaired interaction with putative transcriptional mediators.
- 1997
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - 0027-8424. ; 94:1, s. 248-53
-
Tidskriftsartikel (refereegranskat)abstract
- The syndrome of resistance to thyroid hormone is characterized by elevated serum free thyroid hormones, failure to suppress pituitary thyrotropin secretion, and variable peripheral refractoriness to hormone action. Here we describe a novel leucine to valine mutation in codon 454 (L454V) of the thyroid hormone beta receptor (TR beta) in this disorder, resulting in a mutant receptor with unusual functional properties. Although the mutant protein binds ligand comparably to wild-type receptor and forms homo- and heterodimers on direct repeat, everted repeat, or palindromic thyroid response elements, its ability to activate transcription via these elements is markedly impaired. The hydrophobic leucine residue lies within an amphipathic alpha-helix at the carboxyl terminus of TR beta and the position of the homologous residue in the crystal structure of TR alpha indicates that its side chain is solvent-exposed and might interact with other proteins. We find that two putative transcriptional mediators (RIP140 and SRC-1) exhibit hormone-dependent association with wild-type TR. In comparison, the interaction of this natural mutant (L454V) and artificial mutants (L454A, E457A) with RIP140 and SRC-1 is markedly reduced. Furthermore, coexpression of SRC-1 is able to restore the transcriptional activity of the L454V mutant receptor, indicating that the interaction of this residue with accessory proteins is critical for transcriptional activation. Finally, the occurrence of the L454V mutation in resistance to thyroid hormone, together with impaired negative regulation of the thyroid-stimulating hormone alpha promoter by this mutant, suggests that the amphipathic alpha-helix also mediates hormone-dependent transcriptional inhibition, perhaps via interaction with these or other accessory factors.
|
|
| 6. |
|
|
| 7. |
- Hansson, Lars-Anders, et al.
(författare)
-
Consumption patterns, complexity and enrichment in aquatic food chains
- 1998
-
Ingår i: Royal Society of London. Proceedings B. Biological Sciences. - : The Royal Society. - 1471-2954. ; 265:1399, s. 901-906
-
Tidskriftsartikel (refereegranskat)abstract
- The interactions between consumers and prey, and their impact on biomass distribution among trophic levels, are central issues in both empirical and theoretical ecology. In a long-term experiment, where all organisms, including the top predator, were allowed to respond to environmental conditions by reproduction, we tested predictions from `prey-dependent' and `ratio-dependent' models. Prey-dependent models made correct predictions only in the presence of strong interactors in simple food chains, but failed to predict patterns in more complex situations. Processes such as omnivory, consumer excretion, and unsuitable prey-size windows (invulnerable prey) increased the complexity and created patterns resembling ratio-dependent consumption. However, whereas the prey-dependent patterns were created by the mechanisms predicted by the model, ratio-dependent patterns were not, suggesting that they may be right for the wrong reason'. We show here that despite the enormous complexity of ecosystems, it is possible to identify and disentangle mechanisms responsible for observed patterns in community structure, as well as in biomass development of organisms ranging in size from bacteria to fish.
|
|
| 8. |
|
|
| 9. |
- Landin-Olsson, Mona, et al.
(författare)
-
Appearance of islet cell autoantibodies after clinical diagnosis of diabetes mellitus
- 1999
-
Ingår i: Autoimmunity. - : Informa UK Limited. - 0891-6934 .- 1607-842X. ; 29:1, s. 57-63
-
Tidskriftsartikel (refereegranskat)abstract
- Islet cell antibodies (ICA) and glutamic acid decarboxylase antibodies (GAD65Ab) are often present at diagnosis of insulin dependent diabetes mellitus (type I diabetes) and are supposed to decline in level and frequency during the first years of disease. We have analysed ICA and GAD65Ab at onset and after one gear in 395 population based randomly selected 15-34 year old patients newly diagnosed with diabetes mellitus, to study how these autoantibodies persist, disappear and appear and their relation to C-peptide levels. Of the 395 samples 212 (54%) were positive for ICA, 250 (63%) were positive for GAD65Ab and 170 (43%) were positive for both. At follow up after one year, 27/183 (15%) of the ICA negative patients and 25/145 (17%) of the GAD65Ab negative patients had converted to positivity. Among the 103 patients negative for both ICA and GAD65Ab, 16 turned positive for one or both antibodies after one year. Patients converting to positivity for one or the other antibody after one year, had lower C-peptide levels after one year than patients who initially were and remained negative, supporting the hypothesis that these patients have a genuine type I diabetes. In conclusion, newly diagnosed patients may be negative for autoantibodies at diagnosis but develop these antibodies later on during the disease.
|
|
| 10. |
- Larsson, LG, et al.
(författare)
-
The Swedish randomised mammography screening trials: analysis of their effect on the breast cancer related excess mortality
- 1996
-
Ingår i: Journal of medical screening. - : SAGE Publications. - 0969-1413 .- 1475-5793. ; 3:3, s. 129-32
-
Tidskriftsartikel (refereegranskat)abstract
- –To apply an indirect method for estimation of the breast cancer related excess mortality in the Swedish randomised mammography screening trials.Setting–Randomised trials on mammography screening have, in Sweden, been performed in the counties of Kopparberg (W) and Östergötland (E), the so called WE study, and in the three largest cities in Sweden, Stockholm (southern part), Gothenburg, and Malmö. An overview of the trials was presented in the Lancet in 1993 and included 156 911 women in the invited group and 125 866 in the control group.Methods–The excess mortality in the breast cancer subgroups was estimated by indirect standardisation using official national cause of death statistics according to Statistics Sweden as a reference. Results—The estimated reduction of the breast cancer related mortality was 24% for the whole group (40–74 years at randomisation). The corresponding figures for the age groups 40–49, 50–59, and 60–69 years were 6%, 28%, and 34% respectively.Conclusion–The results are very similar to those presented earlier based on the traditional comparison of the breast cancer mortality in the invited and in the control group. This analysis further strengthens previous reports on a beneficial effect of mammography screening, which is especially pronounced in the age group 50–69.
|
|
