Amino acid sequences of several fragments of the 25 k protein (molecular mass 24,953 Da) previously isolated from cobra Naja kaouthia (Kukhtina et al. Bioorg. Khim., 2000, vol. 26, pp. 803-807) were determined. Their comparison with the primary structures of known proteins showed that the 25 k protein belongs to the CRISP family and is the first protein of this type identified in cobra venoms.

Amino Acid Sequence↗

PubMedDate not supplied

[Established aspects and current knowledge in biomaterials research].

A review of the currently clinically established biomaterials UHMWPE, Al2O3-ceramic, CoCr- and Ti-based alloys and HA-coatings is given on the basis of recognized and new insights. Advantages and disadvantages as well as prospectives (PE-disease, Ti wear, HA-resorption in vivo etc.) are discussed and documented with results from experimental and clinical experience. New surface hardening techniques for Ti-based alloys are mentioned. Experimental results and singular experience from clinical retrieval study of new plastics (PAEK, Triazin-resin) are presented. Composite materials as a basis for a new generation of isoelastic hip prosthesis stems are described at the end of this paper.

Absorption↗

PubMedDate not supplied

[The biotransformation of the immunostimulant 3-(2-mercaptoethyl)quinazoline-2,4(1H,3H)-dione (AWD 100-041)].

3-(2-Mercaptoethyl)quinazoline-2,4(1 H,3 H)-dione (1; AWD 100-041) is a substance with immunomodulating and immunorestorative activity. After p.o. administration in male Wistar rats at least 7 metabolites are formed and excreted in urine and faeces. The compounds were isolated and identified on the basis of UV and mass spectra. They are S-methylated structures in which sulfoxidation and ring-hydroxylation have been taken place. Four metabolites are also present as sulfate or glucuronide conjugates. The quantity ratio of the phase I to phase II metabolites amounts to 4:1. In the isolated perfused rat liver and rat hepatocyte culture 6 and 5 of the in vivo identified compounds are formed. The sequence of the metabolic pathways could be confirmed by in vitro experiments in which the incubation of synthetically prepared metabolites and the identification of generated biotransformation products were performed. In the lymphocyte and myeloma cell culture solely the disulfide of 1 is formed. After incubation of the S-methyl compound metabolites originate detectable also in vivo. Regarding the main ways of metabolism firstly 1 is attacked by methyltransferases forming the initial metabolite. After that oxidative processes take place leading to the formation of sulfoxides, sulfones as well as ring-hydroxylated compounds. A part of the ring-hydroxylated metabolites are conjugated.

Adjuvants, Immunologic↗