Volume change of double cross-linked poly(aspartic acid) hydrogels induced by cleavage of one of the crosslinks.

In the present paper we report for the first time the development of redox-responsive biocompatible polymer gels. Double cross-linked poly(aspartic acid) hydrogels were prepared using two different cross-linking agents simultaneously. One of the cross-linkers was diaminobutane (DAB), the other cystamine (CYS).

A novel potentiometric method for the determination of real crosslinking ratio of poly(aspartic acid) gels.

In order to obtain nontoxic functional polymer gels for biomedical applications, chemically crosslinked poly(aspartic acid) gels have been prepared using 1,4-diaminobutane as crosslinker. The presence of COOH and amino groups on the network chains renders these gels pH sensitive. Due to the specific hydrophobic-hydrophilic balance, these gels show a significant volume transition at a well-defined pH close to the pK value of uncrosslinked poly(aspartic acid).

Synthesis and swelling properties of novel pH-sensitive poly(aspartic acid) gels.

Chemically cross-linked poly(aspartic acid) (PASP) gels were prepared by the hydrolysis of poly(succinimide) (PSI). The latter was prepared by thermal polycondensation of aspartic acid. The PSI chains were cross-linked by natural amines and amino acid derivatives such as putrescin, spermine, spermidine, lysine and cystamine to obtain biodegradable, biocompatible, amino acid-based hydrogels.

[Controlled drug delivery systems. Paradigm change in pharmacology].

This article is to introduce the readers in the colourful world of controlled drug delivery. These structures are to carry the drug into the place of release for let it there out with proper velocity. So the aim of the researches are not to find the best drug, but to get it into the right place in the right time.

Effect of "stacking" on the resolving power of ultrathin-layer two-dimensional gel electrophoresis.

The resolving power of two-dimensional ultrathin-layer polyacrylamide gel electrophoresis with and without "stacking" was investigated. Side-by-side analysis shows that the use of a properly adjusted upper gel improves the resolution and reproducibility of this sensitive analytical method. The effects of various detergents (Nonidet-P40, Zwittergent, urea) on the ultrathin-layer polyacrylamide gel electrophoresis were also investigated.

[Clinical and prognostic relevance of the Kiel classification of non-Hodgkin lymphomas].

The Kiel classification provides a new subdivision of non-Hodgkin lymphomas into distinct entities showing different clinical and prognostic properties. In comparison with earlier classifications this system defines additional types of lymphoma (e.g.

Clinical and prognostic relevance of the Kiel classification of non-Hodgkin lymphomas results of a prospective multicenter study by the Kiel Lymphoma Study Group.

Clinical and prognostic relevance of the Kiel classification of non-Hodgkin lymphomas (NHL) was investigated in 1127 patients entering a prospective multicenter observation study. Survival of the 782 (69.4 per cent) patients with low-grade malignant NHL (lymphocytic lymphomas, predominantly B-CLL, LP immunocytoma, centrocytic lymphoma, centroblastic-centrocytic lymphoma) exceeded that of the 341 patients (30.

[Therapy of malignant lymphomas].

Prognostic factors in patients with Hodgkin's disease and the non-Hodgkin lymphomas are reviewed and discussed since they form the basis of the therapeutic approach to these conditions. Hodgkin's disease is treated according to stage, histology and other prognostic criteria and the appropriate management is presented in tabular form. In the non-Hodgkin lymphomas, prospective studies using the Kiel classification indicated that these lymphomas could be subdivided into types of low-, intermediate- and high-grade malignancy, each requiring different treatment modalities.

Rosette formation of concanavalin A-treated erythrocytes around polymorphonuclear leucocytes and lymphocytes.

Concanavalin A (Con A) induces rosette formation of erythrocytes around polymorphonuclear leucocytes and lymphocytes in cell suspensions of autologous human blood cells. The effect which is most characteristic in a concentration between 25 and 50 microgram/ml is due to Con A bound on the erythrocyte membrane. A similar effect, although less pronounced, was observed with phytohaemagglutinin at concentrations of 10 and 25 microgram/ml.