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Biomedical subjects

E Olsson

Publications and source records attributed to E Olsson.

At least 37 records · Page 2Linked to original sources
PubMed1999

Coordinated ground forces exerted by buttocks and feet are adequately programmed for weight transfer during sit-to-stand.

The purpose of this study was to test the hypothesis whether weight transfer during sit-to-stand (STS) is the result of coordinated ground forces exerted by buttocks and feet before seat-off. Whole-body kinematics and three-dimensional ground forces from left and right buttock as well as from left and right foot were recorded for seven adults during STS. We defined a preparatory phase from onset of the first detectable anterior/posterior (A/P) force to seat-off (buttock forces fell to 0) and a rising phase from seat-off to the decrease of center of mass (CoM) vertical velocity to zero. STS was induced by an increase of vertical and backward directed ground forces exerted by the buttocks that significantly preceded the onset of any trunk movement. All ground forces peaked before or around the moment of seat-off, whereas all kinematic variables, except trunk forward rotation and hip flexion, peaked after seat-off, during or after the rising phase. The present study suggests that the weight transfer from sit to stand is induced by ground forces exerted by buttocks and feet before seat-off, i.e., during the preparatory phase. The buttocks generate the isometric "rising forces," e.g., the propulsive impulse for the forward acceleration of the body, while the feet apply adequate damping control before seat-off. This indicates that the rising movement is a result of these coordinated forces, targeted to match the subject's weight and support base distance between buttocks and feet. The single peaked, bell-shaped profiles peaking before seat-off, were seen beneath buttocks for the "rising drive," i.e., between the time of peak backward directed force and seat-off, as well as beneath the feet for the "damping drive," i.e., from onset to the peak of forward-directed force and for CoM A/P velocity. This suggests that both beginning and end of the weight transfer process are programmed before seat-off. The peak deceleration of A/P CoM took place shortly ( approximately 100 ms) after CoM peak velocity, resulting in a well controlled CoM deceleration before seat-off. In contrast to the view of other authors, this suggests that body equilibrium is controlled during weight transfer.

Adult↗
PubMed1997

Impaired neuropsychological performance in euthymic patients with recurring mood disorders.

BACKGROUND: Both patients suffering from schizophrenia and patients suffering from recurring mood disorder show cognitive impairments as established by a variety of neuropsychological tests. The aim of the present study was to investigate the neuropsychological performance of euthymic patients who had recurring mood disorder and the possible relationship between episodes of hospitalization and cognitive impairments. METHOD: Twenty-six euthymic patients with a DSM-III-R recurring mood disorder diagnosis were investigated by using the Synonym Reasoning and Block-Test Battery and a part of the Halstead-Reitan Test Battery. RESULTS: An overall lowered performance in the test results was found. There was a significant positive relationship between four different tests and the number of hospitalization episodes; the patients with impaired cognitive functioning had significantly more hospitalization episodes than patients with normal cognitive functioning. CONCLUSION: The results suggest that a subgroup of patients with recurring mood disorder are defined by more relapses and episodes of hospitalization and show cognitive dysfunctions even when euthymic.

Adult↗
PubMed1997

Hip stress during lifting with bent and straight knees.

"Correct" body mechanics during lifting are believed to protect the back by employing knee and hip flexion while keeping the back straight. Lower limb joint stress, however, has been largely ignored. We compared hip cartilage contact stress during "leg lifting" with "back lifting" (lifting with bent or straight knees, respectively) in a subject fitted with a pressure instrumented hip endoprosthesis. Synchronized pressure data and whole-body kinematics and kinetics were collected simultaneously while the subject lifted an 11.8 kg mass from the floor to waist level. The highest pressure, 13.7 MPa, occurred during leg lifting at the antero-lateral femoral head transducers opposed at maximum hip flexion by the postero-superior quadrant of acetabular cartilage. In back lifting, the highest pressure, 11.5 MPa occurred in the supero-lateral aspect of the head, which during hip extension was opposed by the posterior quadrant of the acetabulum. Maximum pressures and hip torques occurred simultaneously with peak hip flexion, during the initial lifting of the burden from the floor. Acetabular contact pressures during leg lifting were on average twice as great as during back lifting, and both techniques generate much greater hip stress than gait (typically 4-6 MPa). Degenerative changes in the articular surface of the acetabulum occur primarily on the postero-superior aspect, corresponding to the locations of peak contact pressures in the present in vivo data. Thus leg lifting puts more stress on the postero-superior region, and probably contributes to more hip cartilage degeneration, than does back lifting. We conclude that although leg lifting may mechanically protect the back, it substantially increases hip cartilage stress.

Aged↗
PubMed1996

Physiotherapy in knee osteoarthrosis: effect on pain and walking.

Patients with knee osteoarthrosis are often referred for physiotherapy and many different types of treatment are given. The value of many of these treatments has been questioned. This study was intended to evaluate the effect of commonly used physiotherapy treatments in a training programme on patients with medial knee osteoarthrosis, scheduled for surgery. The results from this study also provide useful data for further evaluation of different physiotherapy treatments to this patient group. Thirty-four patients were randomised to physiotherapy three times a week for 5 weeks and the other 34 received no treatment. The training programme is described in detail. The patients were evaluated by clinical examination, step test, gait analysis and isokinetic measurements of thigh muscle strength before and after treatment. The patients in the treatment group experienced a feeling of overall improvement in the knee and the ability to descend steps improved when compared to the control group. There were no significant differences in gait, range of motion or isokinetic measurements of muscle strength between the groups. We conclude that physiotherapy as given here made our patients feel better and their ability to descend stairs improved. These improvements are beneficial to the patients and support the positive effects of exercises and activity. Whilst the objective improvements were small, suggesting that this treatment may not be justified, patients in the treatment group believed that they were improved.

Aged↗
PubMed1995

Identification of the causative agent of granulocytic ehrlichiosis in Swedish dogs and horses by direct solid phase sequencing of PCR products from the 16S rRNA gene.

Seven Swedish isolates of Ehrlichia species from the blood of four dogs and three horses with clinical granulocytic ehrlichiosis, were identified by direct solid phase DNA sequencing of polymerase chain reaction (PCR) products from the 16S rRNA gene. The amplified DNA fragments were produced with primers complementary to the universal regions, U1, U2, U5 and U8 of the 16S rRNA molecule. Identical sequences were obtained from all seven isolates. This nucleotide sequence was similar to the sequences deposited in GenBank for Ehrlichia phagocytophila and E equi. The sequence of the Swedish ehrlichiae differed in two nucleotide positions from the E phagocytophila sequence and in three positions from the E equi sequence, and it is tentatively proposed that it is a subspecies of one of these two. The alignment of the sequence of the Swedish isolates with a recently deposited sequence from human cases of ehrlichiosis in the USA revealed 100 per cent identity in a segment of about 1400 bp.

Animals↗
PubMed1994

ARTEMIS-2: an application development experiment with the HELIOS environment.

A medical application is a highly complex system that embraces many data types and a very large number of data processing functions and methods. The development of integrated software engineering environments has deeply changed the conception of applications and the profile of the application developers. In this paper, we address the problem of the development process of a specific multimedia application, called ARTEMIS, within the distributed HELIOS environment. The application is intended to manage information about hypertensive patients, in particular, retrieval and display of administrative, clinical and biological data and display and analysis of digital angiography images and medical reports. The objective is to show how the developer can use, customize and organize the services HELIOS provides. A particular focus is set on reuse strategies and integration during the development process. A scenario has been realized and illustrates the current state of the application. The discussion focuses on the advantages of such distributed environments in medical application development.

Computer Communication Networks↗
PubMed1994

Documentation and information services in the HELIOS project.

In a modern software project large amounts of documentation is produced. All parts of the complex software system require extensive documentation--both for reference purposes and promotional reasons. However, there are some aspects that often are forgotten or badly implemented; (i) the availability of on-line documentation, (ii) integration of the different formats of documentation, and (iii) the world wide promotional aspect. To solve these problems, the Helios project has chosen to integrate its public documentation and software material into a hypertext system using the World Wide Web.

Computer Communication Networks↗
PubMed1994

Usability and efficiency. The HELIOS approach to development of user interfaces.

This paper describes the user interface related services of the HELIOS project. The design and implementation of efficient user interfaces is a prerequisite for successful introduction of computer support in health care ward units. Design principles must be based on a basic understanding of cognitive aspects of human-computer interaction, as well as on detailed knowledge about the specific needs and requirements of the health care professionals. In the HELIOS project, a style guide for design of user interfaces has been developed. The style guide defines detailed design guide-lines together with a set of interface elements specified for the ward domain. Development tools for construction and implementation of user interfaces to ward applications have been developed and integrated into the HELIOS SEE. The tools are based on the TeleUSE product, which has been extended and adjusted to the HELIOS specifications. A set of new widgets, designed to implement health care interface elements, has been incorporated into the development tool.

Computer Communication Networks↗
PubMed1993

Structure-related inhibiting activity of some tobacco cembranoids on the prostaglandin synthesis in vitro.

Structure-related inhibitory effects on the prostaglandin synthesis in vitro have been detected among eight diterpenoids of the cembrane class (1-8). The 4,6-diols 1 and 2 are the most active of the cembranoids studied with IC50 values of 0.36 and 0.39 mM, respectively, as compared with an IC50 value of 1.4 for acetylsalicylic acid. Lower activities are found for cembranoids having undergone oxidation of/at the 11,12 double bond (5-8), while the 4-hydroxy-6-oxocembranoids 3 and 4 exhibit effects lower than those of 1 and 2 but higher than those of 5-8.

Animals↗
PubMed1993

Walking ability after internal fixation of trochanteric hip fractures with Ender nails or sliding screw plate. A comparative study of gait.

The influence of several clinical and radiographic parameters on the functional outcome of 92 patients with trochanteric hip fractures treated at random with either Ender nails or a sliding screw plate (SSP) was prospectively investigated. Apart from other clinical variables such as pain, the use of walking aids, and walking distance, the walking ability of patients was assessed by gait analysis performed on an electronic walkway. The parameters investigated were the maximal vertical force (MVF) and single-limb support phase (SLS). Independent of the type of fixation, no differences were observed between stable and unstable fractures in any of the parameters analyzed six months after surgery. In fractures treated with Ender nails, the use of walking aids and MVF were influenced by a satisfactory fracture reduction. Walking distance was the sole factor correlated with the status of fracture healing. In fractures treated with SSP, the pain was the only clinical variable significantly influenced by the outcome of fracture healing. In trochanteric fractures treated with Ender nails, the quality of fracture reduction was the most valuable predictor of patients' recovery of walking ability.

Aged↗
PubMed1993

Improvement in gait one year after surgery for knee osteoarthrosis: a comparison between high tibial osteotomy and prosthetic replacement in a prospective randomized study.

The aim of this study was to analyse gait improvement one year after high tibial osteotomy and unicompartmental knee arthroplasty in patients with strictly unilateral osteoarthrosis of the medial compartment of the knee. Thirty-six patients, 18 men and 18 women, received a unicompartmental Brigham knee prosthesis and 23 patients, 10 men and 13 women, were operated on with a high tibial osteotomy. Clinical and radiographical assessments were supplemented by a functional test, measurements of thigh muscle torque with a Cybex II dynamometer and analysis on a force plate walkway with electrogoniometers. All patients were assessed prior to, and one year after surgery. Both groups showed overall clinical improvement, as assessed by the British Orthopaedic Association (BOA) score. Pain during walking decreased. The range of knee flexion remained unchanged. The ability to ascend and descend steps improved. The isokinetic thigh muscle torque remained unchanged. In the prosthetic group free walking speed increased from 1.03 to 1.09 m/s (p < 0.001). Step frequency and step length increased (p < 0.001). Single stance phase ratio increased from 0.96 to 0.99 (p < 0.01), indicating a more symmetrical gait. Double stance phase (% gait cycle) of both legs decreased (p < 0.001), indicating a faster transfer of weight during walking. In the osteotomy group, free walking speed did not increase. Step length of the uninvolved leg increased (p < 0.01). Double stance phase of the involved leg decreased (p < 0.001) and double stance phase of the uninvolved leg decreased (p < 0.01). Both groups improved after surgery and there was no difference between the groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Vertical ground reaction force feedback to enhance stroke patients' symmetrical body-weight distribution while rising/sitting down.

A force platform with an auditory output consisting of two electronic balances was used to reinforce symmetrical body-weight distribution in stroke patients. Forty patients randomly assigned to an experimental group or a control group practised rising and sitting down for 15 min, thrice daily, 5 days a week for 6 weeks. The experimental group but not the control group received ground reaction force feedback through the auditory output. Vertical ground reaction forces under each foot were measured with two force plates. Mean difference in improvement of body weight distribution on the paretic leg was 13.2 +/- 10.7 (M, SD) per cent total body weight in the experimental group and 5.1 +/- 6.7 per cent in the control group in rising (p < 0.01) and 12.7 +/- 7.5 per cent total body weight and 4.6 +/- 6.6 per cent in sitting down tests (p < 0.001). The patients in the experimental group achieved in average close to a symmetrical body-weight distribution while rising and sitting down. Improvements in physical performance and sit-stand tests were greater in the experimental group (p < 0.05 and p < 0.01, respectively). No differences were seen in improvement in performance of activities of daily living. Symmetry in body-weight distribution in rising and sitting down correlated with high scores in physical performance, motor function in rising, and with functional ability.

Activities of Daily Living↗
PubMed1992

A prospective randomized study of the use of sliding hip screws and Ender nails for trochanteric fractures of the femur.

The functional outcome of trochanteric hip fractures was investigated prospectively in a group of 92 patients treated at random with either Ender nails or a sliding hip screw. Apart from clinical variables, the walking ability of the patients was assessed by gait analysis performed on an electronic walkway. No perioperative complications were noted. The patients in the Ender group had significantly less blood loss and a shorter operation time than the patients treated with the sliding hip screw, indicating that the former method is more gentle as a primary intervention. However, over time there were more reoperations in the Ender group and the functional outcome, including gait analysis after 6 months, showed more favourable results for fractures treated with the sliding hip screw. We therefore recommend the sliding hip screw for an optimal functional result.

Aged↗
PubMed1992

Evaluation of three different STb assays and comparison of enterotoxin pattern over a five-year period in Swedish porcine Escherichia coli.

The pig intestinal loop (PIL) assay, inhibition enzyme-linked immunosorbent assay (ELISA), and DNA hybridization assay were compared for analysis of Escherichia coli heat-stable enterotoxin b (STb) on 201 porcine E. coli strains. The DNA hybridization had a 95% correlation with the STb ELISA and was therefore chosen as the method for subsequent screening of enterotoxin genes: heat labile (LT), heat-stable a (STa), and/or STb. In contrast to the PIL assay, both the STb ELISA and DNA hybridization assays were more sensitive, reliable, reproducible, and showed good correlation with each other. Consequently, the STb ELISA is preferable for analysis of toxin preparations and screening of E. coli, whereas the DNA hybridization is better for large-scale epidemiologic screening. Escherichia coli strains (n = 437) associated with porcine diarrhea isolated in Sweden during 1989 were investigated. Of the strains, 135 (31%) were positive for at least one of these toxins and, therefore, designated enterotoxigenic E. coli (ETEC). Our results were compared with the enterotoxin pattern found in earlier studies of Swedish porcine strains. The only change in occurrence of toxins was found in strains isolated from piglets less than 1 week of age. LT- and STb-producing ETEC had decreased, and STa-producing ETEC had increased in prevalence. The occurrence of STb among ETEC of weaned pigs was 93%. This toxin was also found to be more common than STa when strains from all age groups were considered.

Animals↗
PubMed1992

Chronic gastroenterocolitis in nine cats.

Lesions of a chronic gastroenterocolitis were found in 9 cats of the Persian breed that were euthanized after a prolonged period of bloody diarrhea. Gross lesions consisted of gastrointestinal edema with prominent Payer's patches, multiple grayish nodules, and a few irregular erosions within the colonic mucosa. Microscopically, the changes were composed of degeneration, necrosis, and proliferation of gastric glandular epithelium, dilated intestinal crypts with lymphoplasmacytic cell infiltration of the lamina propria, and in 1 cat, severe transmural necrosis of the colon. With the Giemsa stain, spiral-shaped organisms in the gastrointestinal lumen and intracellularly in the gastric and the colonic epithelium were observed. These organisms could not be cultured. Although the role of these spiral-shaped organisms was not determined, other agents that could explain the disorder were not found.

Animals↗
PubMed1992

Walking ability after total hip replacement. A comparison of gait analysis in unilateral and bilateral cases.

We studied 50 patients before and after unilateral total hip replacement, and compared them, using gait analysis, with 22 having staged bilateral operations. The average age of the patients was 65 years at the first operation. The mean follow-up was 53 months for the unilateral cases and 27 months, after the second THR, for the bilateral cases. The average interval between first and second THR was 24 months. Patients with bilateral hip disease did not gain optimal function, even on the first side, until both hips had been replaced. Unilateral replacement gave better gait analysis results than did either side after bilateral procedures.

Bone Cements↗