Inhibition of glutaminyl cyclase alters pyroglutamate formation in mammalian cells

Mammalian cell lines were examined concerning their Glutaminyl Cyclase (QC) activity using a HPLC method. The enzyme activity was suppressed by a QC specific inhibitor in all homogenates. Aim of the study was to prove whether inhibition of QC modifies the posttranslational maturation of N-glutamine and N-glutamate peptide substrates. Therefore, the impact of QC-inhibition on amino-terminal pyroglutamate (pGlu) formation of the modified amyloid peptides Abeta(N3E-42) and Abeta(N3Q-42) was investigated. These amyloid-beta peptides were expressed as fusion proteins with either the pre-pro sequence of TRH, to be released by a prohormone convertase, or as engineered amyloid precursor protein for subsequent liberation of Abeta(N3Q-42) after beta- and gamma-secretase cleavage during posttranslational processing. Inhibition of QC leads in both expression systems to significantly reduced pGlu-formation of differently processed Abeta-peptides. This reveals the importance of QC-activity during cellular maturation of pGlu-containing peptides. Thus, QC-inhibition should impact bioactivity, stability or even toxicity of pyroglutamyl peptides preventing glutamine and glutamate cyclization.

Heck reactions of steroidal alkenyl iodides

Heck reactions of some steroid derivatives possessing iodo-alkenyl moiety (17-iodo-androst-16-ene, 1, 17-iodo-4-aza-4-methyl-androst-16-en-3-one, 2, 17-iodo-4-aza-androst-16-en-3-one, 3) were carried out in the presence of palladium catalysts using various olefins (methyl acrylate, ethyl methacrylate, allyl alcohol and allyl acetate) as coupling partners. With methyl acrylate, a side reaction was observed: the coupling product underwent a Diels-Alder reaction with the excess of methyl acrylate resulting in a six-membered carbocyclic E-ring. Reaction conditions of the synthesis of the Heck-product were optimized. Although the coupling with allyl alcohol led to the formation of 21-formyl-16-pregnene derivatives, the synthesis of the corresponding steroidal unsaturated alcohol could be achieved only via hydrolysis of the coupling product of the alkenyl iodide with allyl acetate.

[Clinical experience with Spersadex comp. gtt]

The preparation Spersadex comp. gtt. was tested on three groups of patients (60 patients, 109 eyes) in order to assess its effectiveness in indications outlined by the manufacturer. The preparation has a very favourable antimicrobial, and antiphlogistic action. It proved very effective also in the treatment of chlamydial infections and in the postoperative treatment the combination of the antiphlogistic effect and the antibiotic action proved very useful, though tested only in small groups of patients. Spersadex comp. gtt. is a very effective preparation, well tolerated by patients and it supplements in a useful way the range of eye drops by a new antibiotic-corticoid combination.

[Experience with Cefobid in severe infections complicating immunodeficiency diseases]

As a 3rd generation cephalosporin Cefobid monotherapy was applied during 1985-1986 with 16 hematological patients in immunodeficient, immunosuppressive states where the available aimed and combined antibiotic therapy failed to be effective for the treatment of bacterial infections of grave course and septic character. 4 g/day was the average I.V. dose of Cefobid, higher doses were applied only in especially grave septic states. The hematological patients tolerated well the Cefobid in monotherapy. Recovery form the septic state and excellent clinical effect was found with 9 patients, good effect with 4 and satisfactory effect with 1 patient. In 1 case the therapy had to be stopped owing to drug hypersensitivity. Cefobid is regarded as an antibiotic drug that is effective if used in monotherapy for treating grave, septic infections of hematological patients in immunodeficient--immunosuppressive--myelodepressive states having received earlier antineoplasmic polychemotherapy.

[Onset of Philadelphia chromosome negative chronic myeloid leukemia with symptoms of intrahepatic cholestasis]

The case of a chronic myelogenous leukemia (CML) starting in an unusual form in a young woman is reported. Rapidly progressing icterus was the first and leading symptom of the disease. Simultaneously with the exclusion of the possibility of hepatitis and extrahepatic obstruction of the bile duct the qualitative blood picture roused the suspicion of a myeloproliferative disease. Detailed hematological examinations confirmed Philadelphia chromosome (Ph1) negative CML. Besides the histologically diffuse leukemic infiltration intrahepatic cholostasis could be demonstrated in the background of the icterus. In the chronic and accelerated phase clinical symptoms developing as a consequence of hepatic organic manifestation were dominating. In the authors's case the moderate leukocytosis, initial thrombocytopenia, absence of splenomegaly, early blast-phase and short survival were atypical, characteristic of Ph1 negative CML. The diagnosis and the absence of other associated hepatopathies was supported also by the post-mortem examination. CML beginning with icteric symptoms due to intrahepatic cholostasis is considered as rarity in the literature.