[Carpal tunnel syndrome from a thrombosed median artery--four case reports and review of the literature]. / Karpaltunnelsyndrom auf Grund einer Arteria mediana--Thrombose--Vier Fallbeispiele und Literaturzusammenfassung.

The aetiology of the carpal tunnel syndrome is unknown in most cases. Among our patients we found four with acute thrombosis occurring in a persistent median artery which led to acute carpal tunnel symptoms. The purpose of this study was to compare our cases with those from the literature and to show possible causes for the thrombosis. In conclusion, thrombosis of a persistent median artery as a cause of acute carpal tunnel syndrome is certainly very rare. Sudden onset of pain, local tenderness at the palm and decreased sensation in the median nerve distribution may provide clues for the diagnosis. Prior to surgery ultrasound can be performed to confirm the diagnosis.

An enzymatic method for preparation of homopolymannuronate blocks and strictly alternating sequences of mannuronic and guluronic units.

Two Pseudomonas aeruginosa alginates were lysed by an overexpressed polymannuronate lyase AlxMB (only acting on two or more consecutive, nonacetylated mannuronate units) to prepare either mannuronate blocks (poly-M blocks) with dp approximately 30, or strictly alternating sequences of mannuronic and guluronic acid (poly-MG blocks) with dp > 20. The poly-M blocks were obtained by lysis of a P. aeruginosa polymannuronate that has 50% O-acetylation at C-2 and C-3. The poly-MG blocks were obtained from a P. aeruginosa alginate that contained both mannuronate and guluronate residues. The polysaccharide was first deacetylated and then treated with the lyase to excise the mannuronate units from the alternating-MG blocks. Both types of blocks should have potent biological effects and should provide useful specific substrates for characterisation of other alginate lyases.

Effects of characterised Pseudomonas aeruginosa exopolysaccharides on adherence to human tracheal cells.

This study evaluated, in vitro, the role of different Pseudomonas aeruginosa exopolysaccharides (EPS) in mediating adherence to human respiratory epithelial cells. Two mucoid and non-mucoid isogenic pairs of P aeruginosa strains isolated from patients with cystic fibrosis (CF) and bronchiectasis were used. Adherence was tested with human tracheal epithelial cell lines from CF and normal fetuses. The CF cells bound significantly more bacteria than the normal cells. The strain from the bronchiectasis patient was significantly more adherent than that from the CF patient and this difference was consistently most marked with the non-mucoid variant and with normal epithelial cells. The differing behaviour of mucoid CF and non-mucoid bronchiectasis strains reflected the chemical composition of their EPS: mainly alginate in the former and neutral polysaccharides in the latter. Additive inhibition experiments with chemically characterised EPS indicated that neutral polysaccharides associated with alginate may act as ligands for the adherence of P. aeruginosa to CF epithelial cells.

Catalytic properties and specificity of a recombinant, overexpressed D-mannuronate lyase.

Lysis of alginates and of their saturated and unsaturated fragments was monitored by 1H NMR spectroscopy. AlxM(B) alginate lyase performs beta-elimination on the mannuronic acid (M) residues. It does not cleave the guluronic acid (G) sequences, nor the M-G or the G-M diads. In consequence, it is a true mannuronate lyase. The end product of the reaction is O-(4-deoxy-alpha-L-ery-thro-hex-4-enopyranosyl-uronic acid)-(1->(4)-O-(beta-D-mannopyranosyluronic acid)-(1->4)-O-beta-D-mannpyranuronic acid. Viscosity measurements made during degradation of a polymannuronate alginate showed that AlxM(B) behaves as an endo-enzyme. HPLC analysis of the degradation products of oligomannuronates and oligoalginates suggested that the beta-elimination requires the interaction of the enzyme with at least three sequential mannuronic acid residues. The catalytic site may possess 5 sub-sites and accommodate pentamers with different M/G ratio. Kinetic measurements showed that the specificity constant Vm/Km increased with the number of mannuronic acid residues. AlxM(B) may be reversibly inhibited by heteropolymeric blocks in a competitive manner.

LasA, alkaline protease and elastase in clinical strains of Pseudomonas aeruginosa: quantification by immunochemical methods.

Thirty Pseudomonas aeruginosa strains were isolated from the sputa of cystic fibrosis patients. In each culture supernatant, the amount of three exoproteases (LasA, alkaline protease and elastase) was determined using immunochemical procedures. These assays used selected peptide-MAP (multiple antigen peptide) strategy as antigen for animal immunisation. The method appeared to be reproducible, simple, sensitive and specific without cross-reactivity between the antisera. The resulting values differed from one strain to another mostly for elastase production. Despite the fact that four genes (lasA, lasB, lasR and rhlR) were shown to be necessary for full elastolytic activity, it was obvious that if LasA was not secreted in a naturally non-elastase-producing strain, in return in an elastase-producing strain, there were no apparent relationships between LasA and elastase production and between LasA and alkaline protease secretion. Furthermore, in vitro, the secretion of the three exoproteases seemed to be independent of the mucoid or non-mucoid phenotype of the bacteria.

Cloning, sequencing and overexpression in Escherichia coli of the alginatelyase-encoding aly gene of Pseudomonas alginovora: identification of three classes of alginate lyases.

A gene of Pseudomonas alginovora, called aly, has been cloned in Escherichia coli using a battery of PCR techniques and sequenced. It encodes a 210-amino-acid alginate lyase (EC 4.2.2.3), Aly, in the form of a 233-amino-acid precursor. P. alginovora Aly has been overproduced in E. coli with a His-tag sequence fused at the C-terminal end under conditions in which the formation of inclusion bodies is avoided. His-tagged P. alginovora Aly has the same enzymic properties as the wild-type enzyme and has the specificity of a mannuronate lyase. It can be purified in a one-step procedure by affinity chromatography on Ni(2+)-nitriloacetate resin. The yield is of 5 mg of enzyme per litre of culture. The amplification factor is 12.5 compared with the level of production by wild-type P. alginovora. The six alginate lyases of known primary structure fall into three distinct classes, one of which comprises the pair P. alginovora Aly and Klebsiella pneumoniae Aly.

Overproduction and properties of the mannuronate alginate lyase AlxMB.

In previous studies (Malissard et al., FEMS Microbiol. Lett. (1993) 110, 101-106), the alginate lyase AlxM of the marine bacterium ATCC 433367 was produced in Escherichia coli TC4/pAL-A3 with a yield of 50 micrograms per litre of culture. The polypeptide chain was cleaved between two cysteine residues, C169 and C183, themselves linked by a disulphide bridge. AlxM has now been overproduced in E. coli BL21(DE3)/pAL-Sur/pLysS. Under conditions in which formation of inclusion bodies can be avoided, the enzyme is synthesized as a catalytically active, water-soluble, unnicked polypeptide with a yield of 32 mg per litre of culture. It has been purified to protein homogeneity using a one-step procedure. The nicked AlxMA and unnicked AlxMB alginate lyases have identical alginate-degrading activities at high salt concentrations.

Comparative immunochemistry of two fragments from domains Ib and III of Pseudomonas aeruginosa exotoxin A.

Two rabbit polyclonal antisera have been produced by immunization with two fragments corresponding to sequences 392 to 404 and 392 to 613 of Pseudomonas aeruginosa exotoxin A. Both antisera inhibit the ADP-ribosyltransferase activity of exotoxin A but do not inhibit its NAD-glycohydrolase activity. In addition, only the second antiserum was capable of neutralizing exotoxin A cytotoxicity in cell culture and in vivo. Consequently, the common sequence 392 to 404 of the two fragments is not a neutralizing epitope and such an epitope should reside within residues 405 to 613 of exotoxin A. The sequence 392 to 404 was shown to be hidden in the native molecule, and the results suggest that this sequence is most likely in close proximity to residues involved in eukaryotic elongation factor 2 binding.

Characterization of the sporulation-related gamma-D-glutamyl-(L)meso-diaminopimelic-acid-hydrolysing peptidase I of Bacillus sphaericus NCTC 9602 as a member of the metallo(zinc) carboxypeptidase A family. Modular design of the protein.

The sporulation-related gamma-D-glutamyl-(L)meso-diaminopimelic-acid-hydrolysing peptidase I of Bacillus sphaericus NCTC 9602 has been analysed by proton-induced X-ray emission. It contains 1 equivalent Zn2+ per mol of protein. As derived from gene cloning and sequencing, the B. sphaericus Zn peptidase I is a two-module protein. A 100-amino-acid-residue N-terminal domain consisting of two tandem segments of similar sequences, is fused to a 296-amino-acid-residue C-terminal catalytic domain. The catalytic domain belongs to the Zn carboxypeptidase A family, the closest match being observed with the Streptomyces griseus carboxypeptidase [Narahashi (1990) J. Biochem. 107, 879-886] and with the family prototype, bovine carboxypeptidase A. The catalytic domain of the B. sphaericus peptidase I possesses, distributed along the amino-acid sequence, peptide segments, a triad His162-Glu165-His307 and a dyad Tyr347-Glu366 that are equivalent to secondary structures, the zinc-binding triad His69-Glu72-His196 and the catalytic dyad Tyr248-Glu270 of bovine carboxypeptidase A respectively. The N-terminal repeats of the B. sphaericus peptidase I have similarity with the C-terminal repeats of the Enterococcus hirae muramidase 2, the Streptococcus (now Enterococcus) faecalis autolysin and the Bacillus phi PZA and phi 29 lysozymes, to which a role in the recognition of a particular moiety of the bacterial cell envelope has been tentatively assigned. Detergents enhance considerably the specific activity of the B. sphaericus peptidase I.

Sequence of a gene encoding a (poly ManA) alginate lyase active on Pseudomonas aeruginosa alginate.

The recombinant plasmid pAL-A3 bears a (poly ManA) alginate lyase-encoding gene that originates from the marine bacterium ATCC 433367 (Brown et al., Appl. Environ. Microbiol. (1991) 57, 1870-1872). The alginate lyase produced by Escherichia coli TC4 harbouring pAL-A3 was purified to protein homogeneity and the corresponding gene sequenced, giving access to the first known primary structure of an alginate lyase. The 265-amino acid residue alginate lyase showed lytic activity on a Pseudomonas aeruginosa alginate isolated from a cystic fibrosis patient. Unexpectedly, the alginate lyase thus characterized differed from that isolated from the culture medium of the bacterium ATCC 433367 (Romeo and Preston, Biochemistry (1986) 25, 8385-8391).

Identification of a small epitope in domain Ib of Pseudomonas aeruginosa exotoxin A that elicits enzyme-neutralizing antibodies.

A peptide corresponding to amino acids 392-404 of the amino acid sequence of Pseudomonas aeruginosa exotoxin A (the last 13 amino acids of domain Ib) was synthesized and coupled to thyroglobulin. The conjugate induced an antiserum in rabbits with high antibody titer against native toxin as measured by ELISA, and this antiserum was highly efficient in inhibiting the ADP-ribosyltransferase activity of exotoxin A. These data corroborate the potential importance of amino acids 400-404 in the enzymatic mechanism of exotoxin A.

Comparison of four procedures for measuring elastase production by Pseudomonas aeruginosa strains from cystic fibrosis patients.

Forty-five Pseudomonas aeruginosa strains were isolated from the sputa of cystic fibrosis patients. The elastase production of each strain was assayed in the culture supernatant using four different procedures, i.e. two immunological assays (RIA and ELISA), and two enzymatic assays, the latter employing either elastin or tetraalanine as substrate, with conductometric measurement of substrate hydrolysis. Elastase concentrations were determined from standard curves prepared with the same purified elastase, and expressed in mg of elastase per litre of supernatant. The resulting values were in the range reported in the literature, and differed greatly from one strain to another (0-230 mg/l). Linear relationships were found when assays were compared in pairs. Significant correlation coefficients were obtained (r greater than 0.76, p less than 0.001) but the values were quite different for different assays. Thus, ELISA measurements were always from three to five times higher, and RIA results were from two to five times lower, than those from the other assays. Enzymatic assays with elastin gave higher values than those using tetraalanine. Most P. aeruginosa strains produce two other proteinases, alkaline proteinase and Las A protein. Both enzymes have limited elastolytic and peptidasic activities. The presence of alkaline proteinase does not result in falsely elevated elastase values, but an increase of elastase activity was observed when Las A was preincubated with elastin. Since this increase was not observed when tetraalanine was used as the substrate, the presence of Las A in the supernatants could explain the differences observed between the enzymatic assays. The assay with the synthetic substrate is therefore preferred.

Cloning and nucleotide sequence of the gene encoding the gamma-D-glutamyl-L-diamino acid endopeptidase II of Bacillus sphaericus.

The gene encoding the Bacillus sphaericus gamma-D-glutamyl-L-diamino acid endopeptidase II, a cytoplasmic enzyme involved in cell sporulation [1], contains the information for a 271-amino acid protein devoid of a signal peptide. The endopeptidase lacks sequence relatedness with other proteins of known primary structure except that its C-terminal region has significant similarity with the C-terminal region of the 54-kDa P54 protein of Enterococcus faecium, of unknown function [2].

Purification and partial characterization of the gamma-D-glutamyl-L-di-amino acid endopeptidase II from Bacillus sphaericus.

1. A gamma-D-glutamyl-L-di-amino acid endopeptidase II (EC3.4.-.-) active on the peptide moieties of some bacterial peptidoglycans has been purified to homogeneity from the sporulation medium and from the spores of Bacillus sphaericus. 2. Enzyme from both sources showed a single protein band (Mr 28,000) by polyacrylamide gel electrophoresis under denaturing conditions. It is an acidic protein (pI 4.1). Kinetic studies have shown a Km value of 0.24 mM and an apparent Vmax of 8.3 mumol min-1 mg-1 with the pentapeptide L-Ala-gamma-D-Glu-L-Lys-D-[14C]Ala-D-[14C]Ala as substrate. 3. The enzyme was inhibited by p-hydroxymercuribenzoate, a sulfhydryl inhibitor. 4. The 38-residue N-terminal region was sequenced. It may be useful to construct a nucleotide probe for the research of the gene encoding this enzyme.

A Pseudomonas aeruginosa alginate-exotoxin A conjugate that elicits anti-alginate and exotoxin A-neutralizing antibodies.

Pseudomonas aeruginosa alginate was covalently coupled to exotoxin A by reductive amination using adipic acid dihydrazide as spacer. The conjugate was composed of 25% alginate and 75% exotoxin A and possessed an average molecular mass higher than 700 kDa as determined by polyacrylamide gel electrophoresis. The conjugate had virtually no ADP-ribosyltransferase activity and a reduced cytotoxicity for TSA8 murine cells, derived from Friend erythroleukemia cells, as indicated by a greater than 50-fold increased LD50. Anti-conjugate antibodies recognized exotoxin A and alginate. A booster injection resulted in markedly increased antibody ELISA titers to both exotoxin A and alginate. The antibodies neutralized the exotoxin A toxicity.

Biochemical and immunochemical studies of proteolytic fragments of exotoxin A from Pseudomonas aeruginosa.

Limited proteolysis of Pseudomonas aeruginosa exotoxin A by four proteases (chymotrypsin, Staphylococcal serine proteinase, pepsin A and subtilisin) resulted in the formation of polypeptides having a molecular mass of approximately 25 kDa. They possessed both enzymatic activity and residual antigenicity. Their N-terminal sequence analysis showed that the different proteases cleaved exotoxin A in a very restricted area within domain Ib (amino acids 365-404). As a result, the polypeptides contained a large portion (13-34 amino acids) of domain Ib linked to the adjacent C-terminal domain III (amino acids 405-613). The major fragment derived from subtilisin cleavage, at a final yield of 35% (S-fragment; residues 392-613; 24201 Da; pI 4.7) possessed the same level of ADP-ribosyltransferase activity as uncleaved exotoxin A (by mass), and a 37-fold higher NAD-glycohydrolase activity. Polyclonal antibodies from rabbits against exotoxin A completely inhibited the ADP-ribosyltransferase activity of both exotoxin A and the S-fragment, but not the NAD-glycohydrolase activity of the S-fragment. Antibodies against the S-fragment neutralized the ADP-ribosyltransferase activity of exotoxin A. These data determine the primary proteolytic cleavage site of exotoxin A, suggest that some residues in the amino acid sequence 392-404 of exotoxin A seem to have a role in binding or positioning elongation factor 2 (EF-2) and show that antibodies recognize the EF-2-binding site but not the NAD(+)-binding site.

The cytotoxicity of Pseudomonas exotoxin A, inactivated by modification of the cell-binding domain I, is restored when conjugated to an erythroid cell-specific targeting agent.

To be capable of selective killing of tumor cells, the non-selective Pseudomonas aeruginosa exotoxin A must have its cell-binding domain inactivated or removed and then be chemically linked to, or genetically fused with, a specific targeting agent. In the present study, epsilon-NH2 groups of lysine residues of the cell-binding domain of exotoxin A were extensively propionylated with N-succinimidyl-3-propionate (NSP). The NSP-treated exotoxin retained its cytocidal ADP-ribosyltransferase activity, but it could no longer bind to, and inhibit the proliferation of, Friend murine erythroleukemia cells. Cytotoxicity (i.e., the ability to inhibit proliferation) for the Friend erythroid cells was restored completely to the NSP-inactivated exotoxin by conjugating it to ADIF, an autocrine factor secreted by chicken erythroleukemia cells which selectively inhibits the differentiation of erythroid cells such as Friend erythroleukemia cells without inhibiting their proliferation.

Somnogenic activity of O-acetylated and dimeric muramyl peptides.

Slow-wave sleep-promoting factors in brain and urine were identified as muramyl peptides (MPs), the building blocks of bacterial cell wall peptidoglycan. In this study, structural variations of MPs that occur naturally in bacterial peptidoglycan were investigated for somnogenic activity. Monomeric and dimeric MPs were isolated and purified from Neisseria gonorrhoeae and Actinomadura sp. strain R39. The structures of these MPs were verified by fast atom bombardment mass spectroscopy and tandem mass spectroscopy. After intracerebroventricular administration of MPs, electroencephalograms and brain temperatures of rabbits were recorded for 6 h and were analyzed to determine durations of slow-wave sleep, rapid-eye-movement sleep, and wakefulness. The 6-O acetylation of muramic acid enhanced the somnogenic effects of certain monomeric MPs relative to their non-O-acetylated (but otherwise identical) counterparts. Two monomeric MPs containing an unsubstituted amide (i.e., Iso-Gln) were inactive, thus confirming previous results showing that amidation of a variety of MPs can block somnogenic activity. Two peptide-cross-linked MP dimers tested had no effect on slow-wave sleep, although a third peptide-cross-linked MP containing a 1,6-anhydro muramyl end on one of its monomeric subunits, a structure that enhances somnogenic potency of un-cross-linked monomers, was somnogenic. Two dimers connected by glycosidic bonds and containing an Iso-Gln moiety were inactive. Two other glycosidically linked dimers that also contained an Iso-Gln moiety, but were of lower molecular weight, were somnogenic. In summary, 6-O acetylation of muramic acid in somnogenic MPs enhances activity, and as a class, peptide-linked dimeric MPs tend to be less active than their constituent monomers.

Bacterial lipopeptides induce ion-conducting pores in planar bilayers.

Bacterial lipopeptides, known for their antibiotic activities, have been tested for their ability to interact with lipid membranes. These lipopeptides, Iturin A, Bacillomycin L and D and Peptidolipin NA present analogous structural characteristics: a heptapeptidic cycle is linked to a hydrocarbon chain. We present evidence that these lipopeptides modify the conductance of planar bilayers by forming ion-conducting pores.

Purification and partial characterization of the extracellular gamma-D-glutamyl-(L)meso-diaminopimelate endopeptidase I, from Bacillus sphaericus NCTC 9602.

The gamma-D-glutamyl-(L)meso-diaminopimelate endopeptidase, or endopeptidase I, from Bacillus sphaericus 9602 was purified to apparent protein homogeneity. The purification was achieved by a six-step procedure: ammonium sulfate fractionation, phenyl-Sepharose chromatography, two consecutive DEAE-Trisacryl chromatographies, chromatofocusing and Sephacryl S-200 permeation chromatography. The enzyme was purified 5000-fold with a 38% recovery of lytic activity. It is an acidic protein (pI 5.4) of hydrophobic nature. Kinetic studies have shown a Km value of 0.57 mM and an apparent Vmax of 8.3 mumol min-1 (mg enzyme)-1 with N-acetylmuramyl-L-alanyl-gamma-D-glutamyl-(L)meso-diaminopimelyl (L)-D-[14C]alanine as substrate. The enzyme was inhibited by o-phenanthroline and EDTA and was reactivated by zinc, cobalt and manganese ions; thus endopeptidase I is a metallo enzyme, probably a zinc enzyme. Moreover it is a heat-stable protein with an apparent inactivation temperature of 80 degrees C.