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Biomedical subjects

O Svensson

Publications and source records attributed to O Svensson.

101 records · Page 6Linked to original sources
PubMed1985

The effect of strontium and manganese on freshly isolated chondrocytes.

The effect of Strontium (Sr) and Manganese (Mn) was studied on freshly isolated chondrocytes obtained from costal cartilage of young male rats. Cells isolated from rats rendered rachitic by oral exposure to Sr or Mn exhibited a decreased synthesis of glycosaminoglycans and collagen as judged by incorporation of 35SO4 and 3H proline. In vitro exposure of chondrocytes from untreated (control) animals to Sr or Mn at concentrations comparable to those found in cartilage from Sr and Mn rachitic rats, lowered the O2 consumption in both groups, but only Sr had any influence on the other parameters studied.

Animals↗
PubMed1985

The forces of ankle joint structures during ergometer cycling.

The ankle joint moment, joint compressive force, and Achilles tendon force obtained during ergometer cycling were calculated by using a quartz force-measuring transducer mounted on the pedal. Six healthy subjects rode in 11 different ways at different workloads, pedalling rates, saddle heights, and pedal foot positions. The mean maximum dorsiflexing load moment about the ankle joint during standardized ergometer cycling was calculated to 30.9 nm. The mean ankle joint compressive force and mean Achilles tendon force measured 1008 N (1.4 times body weight) and 762 N (1.1 times body weight), respectively. The ankle joint moment was significantly changed by a change of workload or pedal foot position.

Achilles Tendon↗
PubMed1984

Harrington instrumentation for thoracic and lumbar vertebral fractures.

Thirty-seven patients with fractures of the thoracic and lumbar spine treated with Harrington instrumentation were reviewed. Twenty-seven patients with a follow-up time of more than 2 years were summoned for a clinical and radiographic examination. This report presents the results related to reduction, stabilization, return of neural function, spinal posture and mobility, and residual disability. It is concluded that Harrington instrumentation can be performed without a substantial number of complications. Its major advantages are early mobilization and ambulation. The operative technique is discussed with special reference to the preservation of the normal configuration of the back. The value of computerized tomography in the preoperative assessment is stressed.

Adolescent↗
PubMed1983

Influence of time and physical activity on blood pressure and heart rate during treatment with beta-blocking agents once daily.

In a cross-over study of 52 middle-aged patients with mild to moderate essential hypertension, we have compared the effect and tolerability of 100 mg atenolol and 100 mg metoprolol given once daily. After 1 1/2 and 3 months of treatment, both systolic and diastolic blood pressure 24 hours after drug intake were significantly lower on atenolol. There were no significant differences after 3 months when blood pressure was read 3-4 hours after dose intake. During exercise, systolic blood pressure and heart rate were--at all work-loads--significantly lower on atenolol. Four patients on metoprolol and one patient on atenolol discontinued treatment owing to side-effects. The results support the need for thorough analysis of the duration of action and influence of physical activity and sympathetic tone in comparisons between presumedly equivalent antihypertensive drugs.

Adult↗
PubMed1981

The influence of supraspinal impulse activity on the intra-axonal transport of transmitter-related substances in rat motor neurons.

The content and intra-axonal transport of acetylcholine (ACh) and the ACh-metabolizing enzymes choline-acetyl-transferase (CAT) and ACh-esterase (AChE) in the rat sciatic nerve were studied after various experimental procedures. The procedures involved: (1) spinal cord transection (SCT) at the thoracic level 1 day to 3 weeks prior to experiments, to abolish nerve activity of the lower motor neurons (in the lumbar intumescence-sciatic nerve) from supraspinal centres; (2) physical training for 2 h daily during 2 weeks in a rodent treadmill, to increase nerve activity from supraspinal levels; and (3) the use of selective neurotoxins to cause degeneration of descending bulbospinal monoaminergic (MA) neurons. The results of these studies demonstrate that supraspinal nerve influence can modify the axonal transport of ACh and cholinergic enzymes in the rat sciatic nerve, and that descending monoamine (MA) pathways may, at least to some extent, participate in this modulation of intraneuronal dynamics in the motor neuron. Since it has been shown by many investigators that factors which have a trophic influence on skeletal muscle cells both in vitro and in vivo are present in motor nerves and transported along the axons in a distal direction, we suggest that the synthesis and axonal transport of such factors may also be under control of supraspinal nerve activity. Therefore, it is possible that metabolic changes and dystrophy of muscles occurring in patients with lesions of the 'upper motor neuron-type' may also, in addition to other factors, be dependent on changes in intra-axonal transport of various substances in the lower motor neuron.

Acetylcholine↗
PubMed1978

Oesophageal function and coronary angiogram in patients with disabling chest pain.

Sixty-four patients with a history of disabling chest pain belonging to groups III or IV classified according to the NYHA criteria were examined with oesophageal function tests, coronary angiography and bicycle ergometry and also answered a symptom questionnaire. At the exercise test, 52 had effort angina; 45 (89%) of them had a pthological coronary angiogram and 22 (42%) had signs of oesophageal dysfunction (OD). OD as the single possible etiological factor for typical effort angina therefore seemed unlikely. Chest pain was absent or atypical at the exercise test in 12 patients, 11 (92%) of whom had signs of OD. This incidence is significantly higher (p less than 0.01) than that found in the patients with effort-related chest pain. Five (42%) of the 12 patients with atypical chest pain at the exercise test had a pathological coronary angiogram, an incidence which is significantly lower (p less than 0.001) than that found in the group with effort-related chest pain. In patients with a history of disabling chest pain but with atypical chest pain in connection with the exercise test, OD was more frequent than coronary disease and therefore more likely to have caused the symptoms.

Adult↗
PubMedDate not supplied

Ankle joint load and leg muscle activity during lifting.

The load on the talocrural joint during three different ways of lifting was compared and discussed with biomechanical and ergonomical aspects. Healthy subjects lifted a 12.8-kg box from floor to table-level with bent and straight knees. The loading moment of force about the bilateral ankle axis was calculated by means of a computerized static sagittal plane model. Electromyography was recorded from the tibial anterior, gastrocnemius, and soleus muscles. The mean maximum loading moment was found to be 68 newton-meters with an estimated joint compressive force of 2.9 times body weight. The lowest loading moments obtained were associated with lifting the burden between bent knees and close to the pelvis.

Adult↗
PubMedDate not supplied

The effect of manganese ingestion, phosphate depletion, and starvation on the morphology of the epiphyseal growth plate. A stereologic study.

Oral administration of manganese to young rats results in poorly mineralized primary spongiosa and an irregularly thickened growth plate with a histologic resemblance to that in vitamin D-deficiency rickets. In the present study, the rachitic lesions were characterized by stereologic methods at the light microscopic level. With increasing doses of Mn in the diet, the animals developed rachitic lesions of increasing severity, i.e., the total height of the growth plate and the relative volume of the hypertrophic zone increased. The experimental animals developed hypophosphatemia, which was dependent on the Mn dose. The observed serum concentrations of Mn and phosphorus are compatible with the idea that MnHPO4 is precipitated in the gut, leaving only small amounts of Mn and phosphate available for absorption. Furthermore, the severity of the rachitic lesions were inversely correlated to the concentration of phosphate in serum. The most important pathomechanism in Mn rickets is phosphate depletion, which per se causes similar rachitic changes, even though Mn also seems to have other effects. Starvation caused a decrease in the height of the growth plate and in the volume fraction of the hypertrophic zone, thus changes contrary to the rachitic lesions.

Animals↗