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Biomedical subjects

K Aström

Publications and source records attributed to K Aström.

8 recordsLinked to original sources
PubMed2002

Positive effects of anabolic steroids, vitamin D and calcium on muscle mass, bone mineral density and clinical function after a hip fracture. A randomised study of 63 women.

A total of 63 women who had an operation for a fracture of the hip was randomly allocated to one year of treatment either with anabolic steroids, vitamin D and calcium (anabolic group) or with calcium only (control group). The thigh muscle volume was measured by quantitative CT. The bone mineral density of the hip, femur and tibia was assessed by quantitative CT and dual-energy x-ray absorptiometry and of the heel by quantitative ultrasound. Quantitative CT showed that the anabolic group did not lose muscle volume during the first 12 months whereas the control group did (p<0.01). There was less bone loss in the proximal tibia in the anabolic group than in the control group. The speed of gait and the Harris hip score were significantly better in the anabolic group after six and 12 months. Anabolic steroids, even in this moderate dose, given in combination with vitamin D and calcium had a beneficial effect on muscle volume, bone mineral density and clinical function in this group of elderly women.

Aged↗
PubMed2001

An independent evaluation of a new method for automated interpretation of lung scintigrams using artificial neural networks.

The purpose of this study was to evaluate a new automated method for the interpretation of lung perfusion scintigrams using patients from a hospital other than that where the method was developed, and then to compare the performance of the technique against that of experienced physicians. A total of 1,087 scintigrams from patients with suspected pulmonary embolism comprised the training group. The test group consisted of scintigrams from 140 patients collected in a hospital different to that from which the training group had been drawn. An artificial neural network was trained using 18 automatically obtained features from each set of perfusion scintigrams. The image processing techniques included alignment to templates, construction of quotient images based on the perfusion/template images, and finally calculation of features describing segmental perfusion defects in the quotient images. The templates represented lungs of normal size and shape without any pathological changes. The performance of the neural network was compared with that of three experienced physicians who read the same test scintigrams according to the modified PIOPED criteria using, in addition to perfusion images, ventilation images when available and chest radiographs for all patients. Performances were measured as area under the receiver operating characteristic curve. The performance of the neural network evaluated in the test group was 0.88 (95% confidence limits 0.81-0.94). The performance of the three experienced experts was in the range 0.87-0.93 when using the perfusion images, chest radiographs and ventilation images when available. Perfusion scintigrams can be interpreted regarding the diagnosis of pulmonary embolism by the use of an automated method also in a hospital other than that where it was developed. The performance of this method is similar to that of experienced physicians even though the physicians, in addition to perfusion images, also had access to ventilation images for most patients and chest radiographs for all patients. These results show the high potential for the method as a clinical decision support system.

Adolescent↗
PubMed2000

Automated interpretation of ventilation-perfusion lung scintigrams for the diagnosis of pulmonary embolism using artificial neural networks.

The purpose of this study was to develop a completely automated method for the interpretation of ventilation-perfusion (V-P) lung scintigrams used in the diagnosis of pulmonary embolism. An artificial neural network was trained for the diagnosis of pulmonary embolism using 18 automatically obtained features from each set of V-P scintigrams. The techniques used to process the images included their alignment to templates, the construction of quotient images based on the ventilation and perfusion images, and the calculation of measures describing V-P mismatches in the quotient images. The templates represented lungs of normal size and shape without any pathological changes. Images that could not be properly aligned to the templates were detected and excluded automatically. After exclusion of those V-P scintigrams not properly aligned to the templates, 478 V-P scintigrams remained in a training group of consecutive patients with suspected pulmonary embolism, and a further 87 V-P scintigrams formed a separate test group comprising patients who had undergone pulmonary angiography. The performance of the neural network, measured as the area under the receiver operating characteristic curve, was 0.87 (95% confidence limits 0.82-0.92) in the training group and 0.79 (0.69-0.88) in the test group. It is concluded that a completely automated method can be used for the interpretation of V-P scintigrams. The performance of this method is similar to others previously presented, whereby features were extracted manually.

Adolescent↗
PubMed2000

Desire for information about drugs. A multi-method study in general medical inpatients.

The purpose of this paper is to investigate patients' drug information preferences using a combination of quantitative and qualitative methods. Patient interviews (n = 299) were conducted on general medical wards in three London teaching hospitals. The purpose was to refine and validate a quantitative 12-item scale, the Intrinsic Desire for Information (IDI), by interfacing quantitative and qualitative data, and to explore the relationship between this scale score and patient demographics. The IDI-scale was subjected to factor analysis. Two secondary factors were found in the IDI scale; a 5-item factor describing the extent of information desired and a weaker 3-item factor describing an inhibited desire for knowledge about illness/drugs. Reliability analysis and multiple regression analysis were undertaken. Responses to open answer questions during the qualitative interviews were transcribed at the bedside and imported into QSR NUD*IST software program for coding and analysis. The methodology employed in this study involved importing quantitative, summative data into a qualitative data base and re-analysing both the quantitative and qualitative data to validate the scale. Age was a predominant factor associated with patient desire for information, although the data suggest that educational and socio-economic status are also influential. Factor 1, the extent of information desired, may have value in targeting receptive patients, or in identifying those who may be refractory to drug information. The refined tool could help health services to effectively target information provision based on evidence, rather than supposition.

Adult↗
PubMed2000

Analysis of epsilon germline transcripts and IL-4 mRNA expression in the adenoids suggests local IgE switching.

BACKGROUND: We have previously observed more frequent occurrence of IgE+ and FcepsilonRI+ cells in adenoids of atopic than nonatopic children. To investigate the hypothesis that the adenoids are involved in IgE production, we analyzed the levels of epsilon germline (epsilonGL), IL-4, and IFN-gamma transcripts in the adenoids in relation to atopy and presence of ear disease. METHODS: Adenoidectomy was performed on 19 atopic and 18 nonatopic children (median age 5 years, range 2-12 years) suffering from otitis media with effusion (OME) (n = 16) or obstructive adenoids hyperplasia (AH) (n = 21). The levels of epsilonGL transcripts, IL-4, and IFN-gamma mRNA were analyzed by competitive reverse transcriptase-PCR. RESULTS: EpsilonGL transcript levels in the adenoids were found to be dependent on IL-4 mRNA expression (P < 0.01) and serum IgE levels (P < 0.05) (R2 = 0.32, n = 37). IL-4 mRNA expression was associated with epsilonGL transcript levels (rs = 0.32, P = 0.05, n = 37), especially among patients with AH (rs = 0.53, P = 0.01, n = 21). No significant differences in IL-4 and IFN-gamma mRNA levels were observed between the groups. CONCLUSIONS: This study supports an IL-4-induced class switch to IgE production in the adenoids that might be of importance for inflammatory reactions in the upper respiratory tract.

Adenoids↗
PubMed1997

A new radiographic method for evaluating the degree of sliding in devices used in hip-fracture surgery.

PURPOSE: To find a practical method for estimating the degree of sliding that occurs in screw-plate devices used in hip-fracture surgery. Greater understanding of the sliding mechanisms in different fracture types should improve surgical technique and reduce the failure rate. METHODS AND RESULTS: In dynamic screw-plate devices, the lag screw slides inside the barrel of the plate. A recent innovation allows the barrel-plate to slide inside a side-plate, thus making possible a combined fracture compression along the neck and the shaft of femur. The lengths of the different parts and the angle of a device in vivo, measured on a radiograph, depend on the position of the femur relative to the photographic film and the roentgen source. We obtained these measurements with a ruler and a protractor from sequential a.p. radiographs of the hip and implemented them in a special computerized program that used the principles of the scaled orthographic and the central projection models. These calculations provided the correct amount of sliding by the lag screw and by the barrel-plate within the side-plate. CONCLUSION: The method presented here can establish the real degree of sliding in screw-plate devices from standard a.p. radiographs independently of the position of the hip.

Algorithms↗