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Biomedical subjects

G Karlström

Publications and source records attributed to G Karlström.

At least 91 records · Page 5Linked to original sources
PubMed1981

Effects of tocainide, an oral analogue of lidocaine, on thromboembolism after total hip replacement.

In an investigation of deep venous thrombosis and pulmonary embolism, where neither dextran nor other antithrombotic drug prophylaxis was employed, 30 patients subjected to total hip replacement under general anaesthesia were randomly allotted to one of two groups. One group (n=15) received tocainide, an oral analogue of lidocaine, as a means of preventing thromboembolism; the other group (n=15) served as a control. In patients given tocainide the frequency of deep venous thrombosis involving the femoral veins, as observed at phlebography, was 60% (9 of 15), and in the control group 73% (11 of 15). The frequency of pulmonary embolism, as determined by pulmonary perfusion lung scanning, was 20% (3 of 15) in the the tocainide group and 33% (5 of 15) in the control group. It was concluded that tocainide administration had no effect as an antithromboembolic agent. Phlebography revealed that the pattern of deep venous thrombosis after total hip replacement was characterized by a high frequency of isolated thigh vein thrombi in the operated leg, probably related to the surgical procedure. A finding of possible clinical significance was that patients given tocainide had a significantly lower intraoperative blood loss than control patients.

Aged↗
PubMed1980

Effect of epidural versus general anaesthesia on calf blood flow.

The arterial inflow into the calf, venous emptying rate and venous capacity were studied by means of venous occlusion plethysmography on the non-operated leg in two groups of patients undergoing total hip replacement. One group of eight patients received epidural blockade intraoperatively, which was prolonged postoperatively for pain relief, while the other group of eight patients was given general anaesthesia with intermittent positive-pressure ventilation intraoperatively and parenteral analgesics for pain relief in the postoperative period. The calf blood flow and venous capacity were lower in patients receiving general anaesthesia when measured at the end of surgery and significantly lower in this group when measured 3 h postoperatively. The sustained reduction of flow in the deep veins of the lower limb might be a significant contributory factor in the initiation of deep venous thrombosis. In three of the eight patients in the general anaesthesia group, the venous emptying rate and venous capacity had decreased 3 h postoperatively to a very low level, indicating thrombus formation in immediate association with the surgery.

Aged↗
PubMed1980

Effect of dextran on fibrinolysis inhibition activity in the blood after major surgery.

Patients undergoing total hip replacement surgery were given 500 ml of 6% dextran 70 or 5% albumin by intravenous infusion on the third postoperative day when the post-traumatic fibrinolysis inhibition has reached its maximum. The large increase in the fibrinolysis inhibition activity measured by a clot-lysis system was counteracted by the infusion of dextran, whereas the albumin infusion had no such effect. The plasma concentration of antiplasmin (chromogenic substrate assay) and the immunologically determined plasma levels of the primary fibrinolysis inhibitor (alpha2-antiplasmin), alpha2-macroglobulin, alpha2-antitrypsin and plasminogen were not changed after the infusion of dextran. It is hypothesized that dextran exerts its effects partly by interfering with the interaction between the primary fibrinolysis inhibitor, fibrin and plasmin(ogen) and by enhancing the activation rate of plasminogen. This observed effect of dextran may be of importance in the prevention of deep venous thrombosis and pulmonary embolic complications, as well as pulmonary microembolism.

Aged↗
PubMed1979

Open fractures of the shaft of the tibia: analysis of wound and fracture treatment.

Cooperation between orthopaedic and plastic surgeons is an important factor in the treatment of open fractures. In this article a report is made on a retrospective study of a 5-year series of open fractures of the shaft of the tibia treated at the University Hospital in Uppsala between 1972 and 1976. The study proves that the change to external fixation of these fractures and 'open' treatment of the wounds has meant that to a large extent the previous use of pedicle flaps to cover skin defects has been replaced by split skin grafts. The results in the reported series were good, with adequate function in most cases. The final results may, however, be less good than they appeared at this early review time.

Adolescent↗
PubMed1977

The determination of molecular-motion parameters from proton-relaxation-enhancement measurements in a number of Gd(III) - antibody-fragment complexes. A comparative study.

Longitudinal and transverse proton relaxation rates for water in the hydration spheres of Gd(III) bound to the non-immune rabbit IgG fragments Fc (C-terminal half of heavy-chain dimer), pFc' (C-terminal quarter of heavy-chain dimer) and Fab (N-terminal half of heavy and light chain) have been measured at a number of frequencies and temperatures using pulsed nuclear magnetic resonance spectrometry. For the fragments Fc and pFc', a full computer analysis showed that the results could be fitted by parameters of similar magnitude to those found previously for IgG. In contrast to the results for the other complexes the Fab -Gd(III) complex showed no slow exchange contribution to the relaxation rates. Under these circumstances it was found possible to obtain an accurate value for the hydration number (q) from measurements of the longitudinal and transverse relaxation rates at a chosen frequency such that the product of the nuclear Larmor frequency (omega1) and the correlation time for the dipolar relaxation processes (tauc) was approximately unity. Water-proton relaxation rates were also determined for the complex of Gd(III) with the Fv fragment of the mouse myeloma protein MOPC 315. A computer analysis of the results revealed a slow exchange contribution to the rates and this gave errors in the variable parameters similar to those observed previously for IgG, Fc and pFc'. The conclusions drawn from the different systems are discussed in terms of the present state of application of the proton relaxation enhancement technique in biology.

Animals↗
PubMed1977

A novel approach to water proton relaxation in paramagnetic ion-macromolecule complexes.

The use of the proton relaxation enhancement (PRE) technique in solutions of macromolecules and paramagnetic ions to obtain information on molecular motion and ion-hydration numbers can be hazardous with the possibility of large errors in the derived parameters. Here we describe a method based on solvent proton-deuteron comparative relaxation measurements at a limited number of different magnetic fields for obtaining, reasonably accurately, rapidly, and unambiguously, certain of the parameters normally obtained from a PRE study. In the non-immune rabbit immunoglobulin G(IgG)-Gd(iii) system, we are able to obtain values for the ion hydration number (q), the residence lifetime of water molecules in the hydration sphere of the ion (tauM) and a correlation time of 5 ns, which can be associated to a large part with a rotational correlation time (tauR) for the Fc portion (C-terminal half of heavy-chain dimer) of the IgG molecule. This shows that there is a rapid internal motion in the Fc region. The limitations and possible applications of the method are discussed.

Binding Sites↗
PubMed1977

Ipsilateral fracture of the femur and tibia.

Thirty-two cases of simultaneous ipsilateral femoral and tibial fractures in thirty-one patients were treated by rigid internal or pin fixation of both fractures in fourteen cases, by rigid internal or pin fixation of one fracture in three, and by conservative management or non-rigid internal fixation in fifteen. Rigid internal or pin fixation of both fractures resulted in a lower incidence of complications and shorter duration of hospitalization and time to healing. An initially active surgical approach also produced considerably better functional end results: twelve of fourteen patients so treated resumed their former occupations, compared with four of thirteen patients treated conservatively.

Femoral Fractures↗
PubMed1976

Difficulties in determining accurate molecular motion parameters from proton relaxation enhancement measurements as illustrated by the immunoglobulin G-Gd(III) system.

Longitudinal and traverse proton magnetic relaxation rates for water in the hydration sphere of Gd(III) bound to non-immune rabbit IgG (immunoglobulin G) have been determined over a wide range of frequencies (4-84 MHz) at constant temperature (19 degrees C) using pulsed nuclear magnetic resonance spectrometry. The rates have also been determined at temperatures between 0 and 40 degrees C for two frequencies (61 and 84 MHz). The rates were fitted to existing theory using a computer least-squares procedure. Further computer analysis was then carried out to determine the sensitivity of the best-fit error to variation in the variable parameters in the theoretical expressions used. These include the water co-ordination number (q) for which it was found large variations could occur (between approximately 2 and 8) for only small changes in the error of best-fit. It was concluded that a slow exchange contribution to the relaxation rates was important in deciding which parameters are poorly determined. A rotational correlation time (tau r) was obtained which suggested there might be considerable internal motion of the Fc region (C-terminal half of heavy-chain dimer) of the IgG molecule. However the possibility of large errors in this value prevented unequivocal conclusions being drawn.

Animals↗
PubMed1975

Percutaneous pin fixation of open tibial fractures. Double-frame anchorage using the Vidal-Adrey method.

From 1970 to 1973, twenty-eight severe open tibial fractures in twenty-seven patients were treated with stable external transfixation by the Vidal-Adrey double-frame method. Excluding one patient who had an amputation because of vascular damage at the time of injury, wound healing was satisfactory in all patients with no primary soft-tissue or deep infection. There was one late infection following secondary intramedullary nailing three months after injury. Secondary skin and bone grafts were part of the original plan of treatment and were easily performed. All patients were able to start range-of-motion exercises in the early postoperative period. In the case of a severely comminuted tibial fracture combined with arterial injury, this method made it possible to observe the limb for a few days before amputation for vascular insufficiency. The average time in the frame was 4.9 months, and then a patellar-tendon bearing plaster case or splint was used. The mean time until full weight-bearing without external support was 7.9 months. In the twenty-two patients who could be assessed, the final result was excellent or good in seventeen and acceptable in five.

Adolescent↗
PubMed1975

Cavus deformity of the foot after fracture of the tibial shaft.

Twenty-three cases of claw foot with limited talocrural and subtalar mobility were the result of muscle contracture of the leg after tibial-shaft fracture. A roentgenographic study including arteriography was performed. It was concluded that the typical short cavus foot is due to fibrous contracture of the muscles in the deep posterior compartment caused by vascular damage, swelling in the deep posterior compartment, or severe muscle laceration. On physical examination the distance between the lateral malleolus and the Achilles tendon was shortened in comparison with the sound side in all cases. This was found to be caused by dorsiflexion in the talocrural joint coincident with adduction in the mid-tarsal joint. The angulation of the foot forced the patients to rotate the leg outward in order to get the feet in parallel position for walking. This deformity could be misinterpreted as an inward malrotation of the tibial fracture. In severe cases a derotating three-dimensional wedge osteotomy of the distal part of the tibia was performed with promising results.

Adolescent↗