Panagrellus redivivus ornithine decarboxylase: structure of the gene, expression in Escherichia coli and characterization of the recombinant protein.

A southern blot analysis of the Panagrellus redivivus ornithine decarboxylase (ODC) gene suggests that it is a single-copy gene that resides on a genomic 3.2 kb EcoRI fragment. Phage clones possessing ODC gene sequences were isolated from a genomic EMBL-4 library and purified. The phage DNA inserts were analysed and a 3.2 kb EcoRI fragment containing the entire ODC gene was isolated. The nucleotide sequence analysis of this fragment reveals that the gene is interrupted by two introns of 47 and 49 bp. In the 5' non-translated region of the gene, putative AP1, VPE2 and c-Myc binding sites were identified. The ODC cDNA was expressed in a bacterial system as a His-fusion protein and the enzyme was purified by Ni(2+)-chelating affinity chromatography. The subunit molecular mass, as deduced from the cDNA and shown by SDS/PAGE, is 47.1 kDa. On the basis of gel filtration analyses it is shown that the active enzyme is a dimer. The specific enzyme activity was determined to be 4.2 mumol CO2/min/mg protein. The enzyme is dependent on pyridoxal 5-phosphate as a cofactor, and the presence of dithioerythritol or other thiol-reducing agents is essential for maximal activity. The Km value for L-ornithine was determined as 44 microM. The Ki values for putrescine, alpha-diffluoromethylornithine, alpha-hydrazino-ornithine and alpha-methylornithine were calculated as 51, 34, 0.34 and 42 microM respectively.

Molecular cloning and characterization of ornithine decarboxylase cDNA of the nematode Panagrellus redivivus.

In a PCR with degenerate primers encoding highly conserved amino acids within ornithine decarboxylases (ODCs) of several organisms, a fragment of the ODC gene of the free-living nematode Panagrellus redivivus was isolated. Northern blot analysis revealed a single 1.7 kb transcript in a mixed-stage population of animals. From this RNA source, a cDNA library was constructed and screened with the PCR fragment. Several cDNA clones were isolated, one of which encodes the complete 435-amino-acid ODC enzyme with a calculated molecular mass of 47.1 kDa. The P. redivivus ODC possesses 126 of the 136 highly conserved amino acids in the enzymes from fungi, invertebrates and vertebrates. Functional amino acids are conserved, suggesting that the two active sites of the P. redivivus ODC are formed at the interface of a homodimer, as described for mammalian ODCs.

The Drosophila nuclear protein Bx42, which is found in many puffs on polytene chromosomes, is highly charged.

The Drosophila nuclear protein Bx42 is present in a set of transcriptionally active puffs on polytene chromosomes. cDNA clones coding for this protein were isolated from a lambda gt11 expression library. The two Bx42 transcripts are ubiquitously expressed and are already detectable in early stages of development. The corresponding genomic region, in 8C7-8, was isolated and sequenced. Both transcripts direct the production of the same basic, highly charged 547 amino acid protein with a calculated 61.1 kDa molecular weight.

The puff-specific Drosophila protein Bj6, encoded by the gene no-on transient A, shows homology to RNA-binding proteins.

The DNA coding for the puff-specific protein Bj6 has been isolated by expression cloning. The gene is localized in 14C1,2 on the X chromosome and is expressed ubiquitously during embryonic development with prominent expression during the first 12 h of embryogenesis. cDNA and genomic clones have been sequenced and show a single open-reading frame of 2.1 kb length, coding for a Mr = 77,000 basic protein. In the aminoterminal half of the protein we detect stretches of repeated amino acids, centrally a region with homology to RNA-binding proteins containing the RNP 1 and RNP 2 consensus motif of RNA binding proteins, and the carboxyterminal part is rich in charged amino acids. The Bj6 protein is a product of the gene no-on transient A, a gene required for normal vision and courtship behaviour in Drosophila.

Acute oral testing for determining antiarrhythmic drug efficacy. I. Quinidine.

Acute oral drug testing with quinidine was used in 18 patients with high grade ventricular arrhythmia. This method involves administering a single large dose of the antiarrhythmic agent, monitoring heart rhythm by means of programmed trendscription and determining blood drug levels at selected intervals. After quinidine was given in a dose of 0.6 g, 10 patients had a positive response, defined as a 50% or greater reduction in ventricular premature beats and abolition of repetitive ectopic beats. Drug action began a mean of 88 minutes after administration, and the mean peak blood quinidine level was 3.2+/-0.5 (standard error) mug/ml. Four patients had a paradoxic increase in arrhythmia. In nine patients the response to acute drug testing was compared with the response to maintenance quinidine therapy with doses of 1.2 and 1.8 g/day. The presence of arrhythmia was assessed with 24 hour ambulatory monitoring and exercise stress testing. With both techniques, seven of nine patients showed results concordant with those of acute testing. Disparity in results of the two methods of drug administration was explained by the serum concentration of quinidine. Acute oral drug testing provides a new approach for determining expeditiously whether quinidine is effective or hazardous in an individual patient.

[Isolation and amino acid composition of two pathologically augmented proteins from psoriatic scales (author's transl)]. / Isolierung und Aminosäurenzusammensetzung zweier pathologisch erhöhter Proteine aus Psoriasisschuppen

Two protein bands of water soluble extracts of psoriatic scales, which appear intensified in disc-electrophoretical separation, were isolated and their amino acid compositions were determined. It could be demonstrated that band 9 was rich of glycine, alanine, aspartic acid, leucine, and serine and that band 10 was rich of glycine, threonine, and serine. Both proteins contained an amino-sugar (galactosamine).

Programmed "trendscription." A new approach to electrocardiographic monitoring.

A new approach to monitoring of episodic but frequently recurring arrhythmias has been developed, consisting of condensation of electrocardiographic information on a special drum recorder, a programmer that permits selection of intervals and durations for monitoring, and a telemetry unit for transmission of the electrocardiographic signal. We used this system to manage three selected cases.