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Biomedical subjects

K G Nilsson

Publications and source records attributed to K G Nilsson.

28 records · Page 2Linked to original sources
PubMed1992

Scintimetry after total knee arthroplasty. Prospective 2-year study of 18 cases of arthrosis and 15 cases of rheumatoid arthritis.

33 consecutive patients (18 arthrosis, 15 rheumatoid arthritis), operated on with total knee arthroplasty and randomized to cemented (18 knees) or cementless fixation (15 knees), were investigated with scintimetry 3, 6, 12, and 24 months postoperatively. Migration was evaluated with simultaneous roentgen stereophotogrammetric (RSA) examinations. The scintimetric activity in the ipsilateral femoral diaphysis decreased and the activity in the tibial diaphysis increased during the observation period. Constant and low activity was recorded in front of the femoral component. This region was chosen as a reference. Three months after surgery, high activity was noted under the tibial component in knees with a preoperative varus deformity. After 2 years, the activity had decreased to the same level as in the patients with a valgus deformity. Diagnosis and mode of fixation did not influence the activity. Low postoperative activity was recorded in the tibial metaphyses if no rotatory displacement of the tibial component occurred.

Adult↗
PubMed1991

Evaluation of micromotion in cemented vs uncemented knee arthroplasty in osteoarthrosis and rheumatoid arthritis. Randomized study using roentgen stereophotogrammetric analysis.

Twenty-four patients (25 knees) with osteoarthrosis (OA) and 19 patients (20 knees) with rheumatoid arthritis (RA) were operated with bi-tricompartmental knee arthroplasty. The patients were randomized to cemented or cementless fixation of the tibial component. The fixation of the tibial components was examined with roentgen stereophotogrammetric analysis (RSA) up to 24 months after operation. The following parameters representing tibial component micromotion were measured: (1) maximum migration of the prosthetic edge (maximum total point motion, MTPM); (2) distal migration of the prosthetic center (subsidence); (3) maximum proximal movements of the prosthetic edge ("lift-off"); and (4) prosthetic rotations, corresponding to internal/external rotation, adduction/abduction, and forward/backward tilt of the tibial component. All prostheses displayed significant micromotions, which tended to decrease 3-6 months after the operation. The average migration after 2 years, when measured as maximum single axis rotation, and MTPM were about 0.9 degrees-1.5 degrees and 1.0-1.5 mm, respectively, in all four groups. There were no statistically significant differences between cemented and cementless prostheses in either the OA or the RA group. The fixation in the RA patients did not significantly differ from that of the OA patients, perhaps because the RA patients had lower weight and were living a more sedentary life.

Aged↗
PubMed1991

Abnormal kinematics of the artificial knee. Roentgen stereophotogrammetric analysis of 10 Miller-Galante and five New Jersey LCS knees.

The in vivo kinematics of two types of unconstrained, posterior cruciate ligament retaining knee prostheses were analyzed 1 year postoperatively using roentgen stereophotogrammetric analysis. Ten knees had the Miller-Galante and five the New Jersey LCS design. The Miller-Galante knees displayed decreased adduction during active flexion when compared with normal knees. In both types of prostheses, there was decreased medial and increased proximal and posterior displacement. The abnormal kinematics probably reflect the design of the articular surfaces, the absence of the anterior cruciate ligament, and the dysfunction of the posterior cruciate ligament.

Aged↗
PubMed1990

Enzymic synthesis of HexNAc-containing disaccharide glycosides.

The following disaccharide glycosides were obtained from the appropriate donor and acceptor glycosides by employing glycosidases from the mollusc Chamelea gallina as catalysts: alpha-D-Galp-OMe (N-acetyl-alpha-D- galactosaminidase), beta-D-GalpNAc-(1----3)-beta-D-Galp-OMe, beta-D-GlcpNAc-(1----3)-beta-D-Galp-OMe, and beta-D-GlcpNAc-(1----6)-alpha-D-Manp-OMe (N-acetyl-beta-D-hexosaminidase). The regioselectivity of the N-acetyl-beta-D-hexosaminidase-catalysed reactions depended on the anomeric configuration of the acceptor. Thus, alpha-D-Galp-OMe gave beta-D-GlcpNAc- (1----6)-alpha-D-Galp-OMe almost exclusively, whereas beta-D-Galp-OMe gave beta-D-GlcpNAc-(1----3)-beta-D-Galp-OMe and beta-D-GlcpNAc-(1----6)-beta-D-Galp-OMe in almost equal amounts. The isolation of the products by chromatography was straightforward.

Animals↗
PubMed1990

Knee motion in total knee arthroplasty. A roentgen stereophotogrammetric analysis of the kinematics of the Tricon-M knee prosthesis.

The three-dimensional kinematics of the Tricon-M knee prosthesis during active knee flexion and extension were recorded in 11 patients with arthrosis or rheumatoid arthritis using roentgen stereophotogrammetric analysis. Twenty-three normal knees constituted the control group. The prosthetic knees displayed the same degrees of freedom regarding rotational and translational movements as the normal knees, although the kinematics were different. A combination of internal rotation, abduction, and lateral translation of the tibia was recorded during flexion, and the reversed movements were recorded during extension. During the first 25 degrees of flexion, these movements were small, reflecting the high congruency between the articular surfaces, while beyond 25 degrees they increased. The normal knees displayed a combination of internal rotation, adduction, and medial translation of the tibia during flexion and the reversed movements during extension. The prosthetic knees also exhibited an increased posterior displacement during increasing flexion when compared with the normal knees. There was a correlation between the positioning of the femoral component in the sagittal plane and the recorded anterior/posterior translations. In conclusion, the kinematics of the Tricon-M knee prosthesis significantly differ from the normal knee, probably because of the design of the prosthesis and the absence of the cruciate ligaments.

Aged↗
PubMed1989

Preparation of nanoparticles conjugated with enzyme and antibody and their use in heterogeneous enzyme immunoassays.

Enzyme conjugates suitable for enzyme-linked immunosorbent assays can be conveniently prepared by binding enzyme and antibody to nanoparticles. Peroxidase and antitransferrin or anti-alpha-fetoprotein were co-immobilized to tresyl activated 40 nm silica particles and the particle conjugates used in heterogeneous enzyme immunoassays for the evaluation of transferrin and alpha-fetoprotein within the concentration range 0.25-1000 ng/ml.

Humans↗
PubMed1989

Enzymic synthesis of di- and tri-saccharide glycosides, using glycosidases and beta-D-galactoside 3-alpha-sialyl-transferase.

The following disaccharide glycosides were obtained in yields of 10-35% from the appropriate donor and acceptor glycosides by employing glycosidases as catalysts: alpha-D-Galp-(1----3)-alpha-D-GalpNAc-OEt (alpha-D-galactosidase), beta-D-Galp-(1----3)-alpha-D-GalpNAc-OEt and beta-D-Galp-(1----3)-beta-D-GalpNAc-OEtBr (beta-D-galactosidase), beta-D-GlcpNAc-(1----6)-beta-D-Galp-OMe and beta-D-GlcpNAc-(1----6)-alpha-D-Manp-OMe (beta-N-acetylglucosaminidase). With beta-D-GlcpNAc-OEtSiMe3 as the acceptor, beta-D-galactosidase gave beta-D-Galp-(1----3)-beta-D-GlcpNAc-OEtSiMe3 almost exclusively, whereas, with beta-D-GlcpNAc-OMe as the acceptor, beta-D-Galp-(1----3)-beta-D-GlcpNAc-OMe was formed in only slightly excess over teh analogous beta-(1----4)-linked glycoside. The use of beta-D-galactosidase and beta-D-galactoside 3-alpha-sialyltransferase in sequence provided a convenient route to the trisaccharide glycosides alpha-D-Neup5Ac-(2----3)-beta-D-Galp-(1----3)-alpha-D-GalpNAc-OEt, alpha-D-Neup5Ac-(2----3)-beta-D-Galp-(1----3)-beta-D-GalpNAc-OE tBr, and alpha-D-Neup5Ac-(2----3)-beta-D-Galp-(1----3)-beta-D-GlcpNAc-OMe.

Acetylglucosaminidase↗
PubMed1989

A device for noninvasive assessment of perfusion pressure in the skin of healthy volunteers.

A device allowing pressure to be applied to a local skin site where the skin blood flow is followed using laser Doppler flowmetry is described. The blood flow was studied on the back of the hand in eight volunteers before and during brachial arterial occlusion and while the external pressure was increased step by step. The flowmetry value during arterial occlusion was 0.3 +/- 0.1 AU, and when the external pressure was increased to 120 mm Hg the values were similar (p = .44). The skin perfusion pressure, defined as the least external pressure needed to achieve flow cessation, was found to be 92 +/- 16 mm Hg (range 70-111 mm Hg), and the mean arterial pressure was 90 +/- 9 mm Hg (NS). The skin perfusion value is in agreement with that found by others using other techniques for measuring blood flow and a circumferent cuff for applying pressure.

Adolescent↗
PubMed1987

A simple strategy for changing the regioselectivity of glycosidase-catalysed formation of disaccharides.

The regioselectivity of glycosidase-catalysed formation of disaccharides can be changed by using alpha- or beta-glycosyl acceptors with various aglycons. The preponderant formation of other than (1----6) linkages can be effected with glycosidases which normally give (1----6) linkages. Thus, an alpha-D-galactosidase can be induced to catalyse the formation mainly of alpha-(1----2)-, alpha-(1----3), or alpha-(1----6)-linked digalactosides. Both the structure of the aglycon and the configuration of the glycosidic linkage can have a pronounced influence on the regioselectivity of disaccharide formation. Enzymic syntheses, in yields of 20-30%, are described of alpha-D-Galp-(1----3)-alpha-D-Galp-OMe, beta-D-Galp-(1----3)-beta-D-Galp-OMe, beta-D-Galp-(1----6)-alpha-D-Galp-OMe, alpha-D-Manp-(1----2)-alpha-D-Manp-OMe, alpha-D-Manp-(1----6)-alpha-D-Manp-OMe, alpha-D-Galp-(1----2)-alpha-D-Galp-OPhNO2-o, alpha-D-Galp-(1----3)-alpha-D-Galp-OPhNO2-p, alpha-D-Manp-(1----2)-alpha-D-Manp-OPhNO2-p, and alpha-D-Manp-(1----2)-alpha-D-Manp-(1----2)-alpha-D-Manp+ ++-OMe. Soluble and immobilised enzymes have been used.

Carbohydrate Conformation↗