Porin F is one of the major proteins of the outer membrane of Pseudomonas aeruginosa. It forms water-filled pores of variable size. Porin F is a candidate for a vaccine against P. aeruginosa because it antigenically cross-reacts in all serotype strains of the International Antigenic Typing Scheme. We have isolated the gene for porin F from a lambda EMBL3 bacteriophage library by using oligodeoxynucleotide hybridization probes and have determined its nucleotide sequence. Different peptide sequences obtained from isolated porin F confirmed the deduced protein sequence. The mature protein consists of 326 amino acid residues and has a molecular weight of 35,250. The precursor contains an N-terminal signal peptide of 24 amino acid residues. S1 protection and primer extension experiments, together with Northern (RNA) blots, indicate that the mRNA coding for porin F is monocistronic with short untranslated regions of about 58 bases at the 5' end and about 47 bases at the 3' end. The sequences in the -10 and -35 regions upstream of the transcriptional start site are closely related to the Escherichia coli promoter consensus sequences, which explains why the porin F gene is expressed in E. coli under the control of its own promoter. The amino acid sequence of porin F is not homologous to the different E. coli porins OmpF, OmpC, LamB, and PhoE. On the other hand, a highly homologous region of 30 amino acids between the OmpA proteins of different enteric bacteria and porin F of P. aeruginosa was detected. The core region of the homology to E. coli OmpA had 11 of 12 amino acid residues in common.

Lipoprotein I (OprI) is one of the major proteins of the outer membrane of Pseudomonas aeruginosa. Like porin protein F (OprF), it is a vaccine candidate because it antigenically cross-reacts with all serotype strains of the International Antigenic Typing Scheme. Since lipoprotein I was expressed in Escherichia coli under the control of its own promoter, we were able to isolate the gene by screening a lambda EMBL3 phage library with a mouse monoclonal antibody directed against lipoprotein I. The monocistronic OprI mRNA encodes a precursor protein of 83 amino acid residues including a signal peptide of 19 residues. The mature protein has a molecular weight of 6,950, not including bound glycerol and lipid. Although the amino acid sequences of protein I of P. aeruginosa and Braun's lipoprotein of E. coli differ considerably (only 30.1% identical amino acid residues), peptidoglycan in E. coli, are identical. Using lipoprotein I expressed in E. coli, it can now be tested whether this protein alone, without P. aeruginosa lipopolysaccharide contaminations, has a protective effect against P. aeruginosa infections.

A defined minimum length of the first exon is required for the generation of spliced products from a synthetic yeast actin mRNA-precursor in vitro. If the first exon is 1, 2, 3 or 5 nucleotides long, only the first step of the splicing reaction can take place. A transcript starting with the first nucleotide of the intron does not get converted into any of the normally obtained splicing products or intermediates. On the other hand, spliceosome assembly does not depend on the presence of a first exon.

Zusammenfassung: Untersucht wurde die Eignung des computergestützten Adaptiven Figurenfolgen-Lerntests (ADAFI), zwischen gesunden älteren Menschen und älteren Menschen mit erhöhtem Demenzrisiko zu differenzieren. Der im ADAFI vorgelegte Aufgabentyp der fluiden Intelligenzdimension (logisches Auffüllen von Figurenfolgen) hat sich in mehreren Studien zur Erfassung des intellektuellen Leistungspotentials (kognitive Plastizität) älterer Menschen als günstig für die genannte Differenzierung erwiesen. Aufgrund seiner Konzeption als Diagnostisches Programm fängt der ADAFI allerdings einige Kritikpunkte an Vorgehensweisen in diesen bisherigen Arbeiten auf. Es konnte gezeigt werden, a) daß mit dem ADAFI deutliche Lokationsunterschiede zwischen den beiden Gruppen darstellbar sind, b) daß mit diesem Verfahren eine gute Vorhersage des mentalen Gesundheitsstatus der Probanden auf Einzelfallebene gelingt (Sensitivität: 80 %, Spezifität: 90 %), und c) daß die Vorhersageleistung statusdiagnostischer Tests zur Informationsverarbeitungsgeschwindigkeit und zum Arbeitsgedächtnis geringer ist. Die Ergebnisse weisen darauf hin, daß die plastizitätsorientierte Leistungserfassung mit dem ADAFI vielversprechend für die Frühdiagnostik dementieller Prozesse sein könnte.

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