Recombinant human synovial fluid phospholipase A2 (rPLA2) and several variants with N-terminal sequences modified by addition or deletion of one or two amino acid residues (ala or Met; Des-Asn1, Leu2) have been expressed in mammalian cells and in Escherichia coli, respectively, purified to homogeneity, and characterized. The observed values for the molecular mass of rPLA2 and variants are in complete agreement with the predicted values for a correctly folded structure containing seven disulfide bridges. Moreover, the relative proportions of the various types of secondary structures of the variants of rPLA2, as measured by CD spectroscopy, are similar to that found for native porcine pancreatic PLA2, indicating that the recombinant proteins are correctly folded. Enzymatic activities of rPLA2 with modified N-termini decreased to 1.3-0.005% of the activity of the mature rPLA2, emphasizing a key role of the N-terminus for catalytic activity.

For the presented group of children with Perthes' disease, we did not find an increased rate of factor V or prothrombin mutations compared to the natural incidence. In accordance to other recent studies, our results do not support a link between inherited thrombophilic mutations and Perthes' disease.

No abstract

The complex kinetics found for the hydrolysis of 1,3,5-trichloro-s-triazine in 9/910/6 (a) acetone/water at 1O.O"C have been evaluated as a function of the hydroxyl ion and the acetate ion concentration using an analogue computer. The kinetics are consistent with a nonsteady state mechanism in which the primary intermediate anion is protonatcd giving a neutral species whose concentration goes through a maximum during the course of the rcaction. This secondary intermediate forms the final product by deprotonation and release of a chloride ion. The product itself can undergo a second (reversible) deprotonation.In dimethylsulfoxide the analogous intermediate of the hydrolysis of 1,3-dimethoxy-5-chloros-triazine can be identified by analysis of the NMR. and UV. spectra.

Non-Hodgkin's lymphoma occurs in up to 30% primarily out of lymph nodes (extranodal). In the abdomen, beside spleen and liver the gastrointestinal tract is often and the kidneys are not rarely affected. However, each abdominal organ and peritoneal space, muscles and skin can be affected at various frequencies. While an exclusive manifestation within an organ without lymphadenopathy is rather unusual, often a concomitant lymphadenopathy is present. A secondary infiltration of an organ due to widespread lymphoma,hematogenous spread or relapse occurs more frequently. On the other hand, in Hodgkin's lymphoma, except spleen and liver other organs are only rarely affected. Mostly it occurs by direct invasion from adjacent pathological lymph nodes.Frequency, morphology at and problems of imaging of extranodal lymphoma are presented.