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Biomedical subjects

E Janssen

Publications and source records attributed to E Janssen.

44 records · Page 3Linked to original sources

Different N-terminal amino acids in the MN-glycoprotein from MM and NN erythrocytes.

The major human erythrocyte membrane (MN-) sialoglycoprotein was purified from MM, MN and NN cells using detergent gel and ion exchange chromatography. N-terminal analyses with dansyl-chloride revealed serine in preparations from MM and leucine in those from NN erythrocytes, whereas glycoprotein isolated from MN cells contained both the above amino acids. These data strongly suggest that the above residues may represent the structural difference between the M and N antigens. Evidence was also obtained that the Ss-glycoprotein, which is associated with "N" activity, exhibits the same N-terminal amino acid (leucine) as the MN glycoprotein from NN cells.

Amino Acid Sequence↗

Ss blood group associated PAS-staining polymorphism of glycoprotein 3 from human erythrocyte membranes.

It is shown by discontinuous sodium dodecylsulfate (SDS) polyacrylamide gel electrophoresis of human red cell membranes, followed by periodic acid Schiff (PAS) staining and densitometry, that the band PAS-3 (monomeric Ss glycoprotein) exhibits a polymorphism with respect to its staining intensity. In membranes of the genotype SS the staining intensity of this band is about 1.5 times higher than in ss membranes. The experimental error of the method does not permit one to decide, whether membranes of blood type Ss exhibit an intermediate staining intensity or not. The SDS electrophoretic molecular weight of PAS-3 is the same for SS, Ss, or ss membranes. The ratio of PAS to coomassie blue staining intensities, which are a measure of sialic acid and protein content, respectively, are equal for PAS-3 in glycoprotein preparations from SS and ss erythrocytes. These data indicate that the above phenomenon reflects a difference in the glycoprotein content between SS and ss membranes.

Erythrocytes↗

Studies on the receptors of the MNSs group system.

Results with modified human red cell membrane sialoglycoproteins indicate that alkali-labile sialic acid and amino groups are parts of the erythrocyte receptor sites recognized by common rabbit and human anti-M and -N sera. The "N" antigen, demonstrable in MM glycoprotein preparations by rabbit anti-N, has structural properties which are similar to those of the MN receptors. Sialic acid, amino groups and carbohydrate, susceptible to periodate oxidation, are not involved in the Ss antigen sites. The specificity of the Vicia graminea lectin is dependent on free amino and carboxyl groups. Its affinity for the substances is increased by blocking of amino groups.

Animals↗

Heterogeneity of human cell membrane sialoglycoproteins.

Discontinuous sodium dodecysulfate polyacrylamide gel electrophoresis (disc SDS-PAGE) followed by periodic acid/Schiff staining reveals the presence of six sialoglycoprotein bands in human red cell membranes or glycoprotein preparations therefrom. In agreement with previous investigations it is shown that PAS-1 and PAS-2 (mol. weight 37 000) are different forms of the same molecule (MN glycoprotein). Using separation of glycoproteins by the system of Weber and Osborn and reelectrophoresis of gel slices by disc SDS-PAGE it is demonstrated that the minor component C (mol. weight 41 000) represents the dimeric form of PAS-3 (Ss glycoprotein). Band B corresponds to an aggregate of PAS-3 and PAS-2 and/or the trimer of PAS-3 with possible differences between extracted glycoproteins and those present in the membrane. The minor component D (mol. weight 35 000) is, as far as could be elucidated, not involved in aggregation phenomena. Some technical problems of glycoprotein fractionation by SDS-PAGE and the remarkable effect of phosphate buffers on the glycoprotein pattern are discussed.

Buffers↗

[Follow-up studies after bicondylar superficial replacement of rheumatoid knee joint destruction].

This study documents prospectively the Knee Society knee- and function score of 28 patients with rheumatoid arthritis with 34 PFC unconstrained total knee arthroplasties from preoperative values on at yearly intervals. The average follow-up period was 3.4 years (range 2-5.5 y). At last follow-up over 80% of the knees were painfree. All but one patient could walk more than 500 m. Knee and function score increased significantly from 30.1 resp. 35.0 to 83.8 resp. 74.6 (P < 0.000001). Postoperatively the knee score rose soon to a constant level whereas the function score showed a continuous slow increase up to 5 years. We observed one deep venous thrombosis and one subluxation. At an intermediate follow-up rheumatoid knees are clinically and functionally successfully operated on using an unconstrained TKA. Pain relief is excellent. We recommend the use of a scoring system assessing knee and functional results separately.

Adult↗

Understanding the rapist's mind.

TOPIC: The motivations and psychology of the rapist. PURPOSE: To provide a framework of sexual perversions so that the motives and psychology of rapists can be better understood. SOURCE: Analytic literature. CONCLUSION: Unconscious motives leading to rape appear related to issues of control, power, and dominance.

Conflict, Psychological↗