Outcomes of upper-extremity tendon transfers and functional electrical stimulation in an adolescent with C-5 tetraplegia.
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Activities of Daily Living↗
Biomedical subjects
A A Weiss
Publications and source records attributed to A A Weiss.
Susceptibilities of Bordetella pertussis strains to antimicrobial peptides.
We examined the susceptibilities of Bordetella pertussis strains to several antimicrobial peptides by determining the concentration required to inhibit or kill 50% of the bacterial population. The peptides are ranked in decreasing potency as follows: cecropin B > cecropin A >> melittin > cecropin P1 > (ala8,13,18)-magainin II amide > mastoparan = defensin HNP1 > protamine > or = magainin II = magainin I. By using a radial diffusion assay to compare susceptibilities between strains, wild-type B. pertussis BP338 was more resistant than the avirulent bvg mutant strain BP347 and the brk mutant strain BPM2041 to killing by cecropin P1. In contrast, compared with the wild type, the avirulent BP347 strain was highly resistant to killing by protamine and defensin HNP1.
Anti-Bacterial Agents↗
Expression of MUC2 and MUC3 mRNA in human normal, malignant, and inflammatory intestinal tissues.
MUC2 and MUC3 are prominent mucin genes expressed in the human intestine. Using in situ hybridization with RNA probes, we examined the cellular distribution of MUC2 and MUC3 mRNA in normal, malignant, and inflammatory human intestinal tissues. In normal small intestine and colon, MUC2 mRNA was expressed exclusively in goblet cells and occurred throughout the entire height of the mucosa. MUC3 mRNA was expressed by goblet and columnar cells but was restricted to the villous compartment of the small intestine and the surface epithelium of the colon. Expression of MUC2 and MUC3 mRNA were both markedly decreased in poorly, moderately, and well-differentiated colon cancers but were preserved in mucinous colon cancers. In ulcerative colitis and Crohn's colitis tissues, MUC2 and MUC3 mRNA expression displayed a normal pattern regardless of whether the mucosa manifested active or quiescent inflammation. These findings indicate that MUC2 is goblet cell-specific, whereas MUC3 is related to maturation of intestinal epithelial cells. In colon cancers, the genetic regulation of MUC2 and MUC3 is different depending on the histological type of tumor. The constitutive expression of MUC2 and MUC3 mRNA in inflammatory bowel diseases suggests that these genes may be necessary for maintenance of normal epithelial cell function during inflammation.
Colitis, Ulcerative↗
Cloning and sequencing of the Bordetella pertussis cpn10/cpn60 (groESL) homolog.
The nucleotide sequence downstream from the Bordetella resistance to killing (brk) locus in Bordetella pertussis was determined. Analysis of the sequence revealed an operon consisting of two highly predicted open reading frames (ORFs). The deduced amino-acid sequence of each ORF has strong homologies to the heat-shock proteins/chaperonins Cpn60 and Cpn10. The promoter contains consensus sequences for both sigma 32 and sigma 70 binding, and it possesses the CIRCE regulatory inverted repeat. A potential Rho-independent terminator was identified and appears to be shared with the brkA gene.
Amino Acid Sequence↗
Cloning and sequencing of a Bordetella pertussis serum resistance locus.
We have characterized a new virulence factor in Bordetella pertussis: serum resistance. Compared with Escherichia coli HB101, wild-type B. pertussis was relatively resistant to classical-pathway, complement-dependent killing by normal human serum. However, a mutant of B. pertussis (BPM2041) which is less virulent in mice and which has Tn5 lac inserted in a previously uncharacterized bvg-regulated gene was found to be at least 10-fold more susceptible to serum killing than the wild type. We have named this locus brk, for Bordetella resistance to killing. We have cloned and sequenced the brk locus, and it encodes two divergently transcribed open reading frames (ORFs), termed BrkA and BrkB. Both ORFs are necessary for serum resistance. Within the 300 bases which separate the two ORFs and upstream of each ORF are putative sites for BvgA binding. BrkA shows 29% identity to pertactin and has two RGD motifs in addition to a conserved proteolytic processing site and an outer membrane targeting signal. Like pertactin, BrkA is involved in adherence and invasion. Despite the similarities, a pertactin mutant was found to be not as sensitive to serum killing as the BrkA or BrkB mutants. BrkB is similar to ORFs in E. coli and Mycobacterium leprae and displays domains of homology to various transporters. On the basis of its hydropathy profile, BrkB is predicted to be a cytoplasmic membrane protein. By Southern blot, brk sequences were found in Bordetella bronchiseptica and Bordetella parapertussis but not in Bordetella avium.
Amino Acid Sequence↗
Characterization of the dermonecrotic toxin in members of the genus Bordetella.
All members of the genus Bordetella and Pasteurella multocida (a gram-negative bacillus genetically unrelated to Bordetella spp., yet often sharing the same ecological niche) produce a dermonecrotic toxin (DNT). The amount of toxin produced and the time required for appearance of the lesions are identical for Bordetella pertussis, B. parapertussis, and B. bronchiseptica but different for P. multocida and B. avium. DNT has been reported to act by promoting vasoconstriction; however, vasoactive compounds (verapamil, prazosin, hydralazine, tolazoline, or isoxsuprine) are able to reverse the action of the toxin only slightly. Vasoconstrictors (atropine, serotonin, epinephrine, or endothelin) did not produce DNT-like lesions. We have characterized a region of DNA essential for DNT expression. We have determined by Southern analysis that the restriction map of the DNT gene is nearly identical in B. pertussis, B. parapertussis, and B. bronchiseptica, but the sequences are not present in toxigenic B. avium and P. multocida strains. A gentamicin resistance-origin of transfer cassette cloned into a 1.8-kb NotI-BamHI fragment results in constructs which can be mobilized and recombined into the Bordetella chromosome, rendering the resultant B. pertussis, B. parapertussis, and B. bronchiseptica strains negative for DNT. A 5-kb BamHI-ApaI fragment from the B. pertussis chromosome was sequenced and revealed homology to the Escherichia coli CNF1 (cytotoxic necrotizing factor 1) toxin.
Amino Acid Sequence↗
Characterization of adenylate cyclase toxin from a mutant of Bordetella pertussis defective in the activator gene, cyaC.
Bordetella pertussis adenylate cyclase (AC) toxin has the abilities to 1) enter target cells where it catalyzes cyclic AMP production and 2) lyse sheep erythrocytes, and these abilities require post-translational modification by the product of an accessory gene cyaC (Barry, E. M., Weiss, A. A., Ehrmann, E. E., Gray, M. C., Hewlett, E. L., and Goodwin, M. St. M. (1991) J. Bacteriol. 173, 720-726). In the present study, AC toxin has been purified from an organism with a mutation in cyaC, BPDE386, and evaluated for its physical and functional properties in order to determine the basis for its lack of toxin and hemolytic activities. AC toxin from BPDE386 is indistinguishable from wild-type toxin in enzymatic activity, migration on SDS-polyacrylamide gel electrophoresis, ability to bind calcium, and calcium-dependent conformational change. Although unable to elicit cAMP accumulation, AC toxin from BPDE386 exhibits binding to the surface of Jurkat cells which is comparable to that of wild-type toxin. This target cell interaction is qualitatively different, however, in that 99% of the mutant toxin remains sensitive to trypsin, whereas approximately 20% of cell-associated wild-type toxin enters a trypsin-resistant compartment. To evaluate the ability of this mutant AC toxin to function at its intracellular site of action, the cAMP-stimulated L-type calcium current in frog atrial myocytes was used. Extracellular addition of wild-type toxin results in cAMP-dependent events that include activation of calcium channels and enhancement of calcium current. In contrast, there is no response to externally applied toxin from BPDE386. When injected into the cell interior, however, the AC toxin from BPDE386 is able to produce increases in the calcium current comparable to those observed with wild-type toxin. Although AC toxin from BPDE386 is unaffected in its enzymatic activity, calcium binding, and calcium-dependent conformational change, the mutation in cyaC does result in a toxin which is able to bind to target cells but unable to elicit cAMP accumulation. In that AC toxin from BPDE386 is able to function normally when injected artificially to an intracellular site, we conclude that the disruption of cyaC produces a defect in insertion and transmembrane delivery of the catalytic domain.
Adenylate Cyclase Toxin↗
Molecular characterization of an operon required for pertussis toxin secretion.
Mutants of Bordetella pertussis which are defective in secretion of pertussis toxin were isolated and characterized. The region of the B. pertussis chromosome identified by mutagenesis as playing a role in transport of pertussis toxin was sequenced. Analysis of this region revealed eight open reading frames, seven of which predict a protein exhibiting homology with one of the VirB proteins of Agrobacterium tumefaciens, which are involved in the transport of the T-DNA molecule across bacterial and plant membranes. Thus a set of accessory proteins are most likely involved in the secretion of pertussis toxin, and these proteins appear to be members of a family of proteins involved in the secretion of macromolecules from bacteria.
Agrobacterium tumefaciens↗
Characterization of environmental regulators of Bordetella pertussis.
Bordetella pertussis suppresses transcription of its virulence genes in response to specific environmental conditions, a response called modulation. The organism responds to high concentrations of SO4 and CIO4 ions, nicotinic acid, and nicotinic acid analogs in vitro; however, the in vivo modulator has not been identified. We investigated which chemical structures of the nicotinic acid molecule are important for modulation by testing various analogs for their ability to modulate. The ring nitrogen of nicotinic acid was not required, since benzoic acid was a modulator. In contrast, the carboxyl group was required, since derivatives like ethylnicotinate, 3-pyridylcarbinol, 3-acetyl pyridine, and 6-chloronicotinamide with altered carboxyl groups were not modulators. The planar ring structure or resonance in the ring was required for modulation, since nipecotic acid failed to modulate. The most potent modulators were nicotinic acid derivatives with electron-withdrawing substituents in the meta or para position relative to the carboxyl group. Relative hydrophilicity of substituents did not appear to contribute to modulation. Although these modulators elicited a clear biological response, the mechanism of modulation remains unclear, because no binding of the modulator 35SO4 or [14C]4-chlorobenzoic acid to whole B. pertussis was detected. However, modulation appears to involve a charge-charge interaction, since the response was blocked by chlorine ions.
Bacterial Proteins↗
What are the current indications for total elbow arthroplasty? Report of a case using allograft for TEA.
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Bone Neoplasms↗
Enzymatic activity of adenylate cyclase toxin from Bordetella pertussis is not required for hemolysis.
Adenylate cyclase (AC) toxin from Bordetella pertussis enters cells to cause supraphysiologic increases in cAMP. AC toxin is also hemolytic. Substitution of Lys-58 with a methionine residue by site-directed mutagenesis of the structural gene for AC toxin, cyaA, and introduction of this mutation onto the B. pertussis chromosome results in an organism that synthesizes an enzyme-deficient AC toxin molecule. This mutant toxin molecule exhibits 1000-fold reduction in enzymatic activity relative to wild-type and has no toxin activity in J774 cells. The enzyme-deficient toxin molecule is not, however, impaired in its ability to lyse sheep red blood cells. In order to ascertain the importance of these two separate activities of AC toxin in vivo the enzyme-deficient organisms were used to infect infant mice. The hemolytic, enzyme-deficient mutant organisms are reduced in virulence relative to wild-type organisms after intranasal challenge indicating that, although the enzymatic activity of AC toxin does not contribute to hemolysis, it is this property of the toxin which is important for virulence of B. pertussis.
Adenylate Cyclase Toxin↗
Index finger pollicization for congenital aplasia or hypoplasia of the thumb.
Sensation, strength, dexterity, length, and range of motion were evaluated after index finger pollicization in 10 patients (14 hands). Diagnoses included congenital absence of the thumb (10 hands) and hypoplasia (4 hands). Average age at operation was 7 years, and follow-up averaged 9 years. Patients with unilateral pollicization averaged 67% grip strength, 60% lateral pinch, 56% palmar pinch, and 39% three-point pinch as compared with the normal contralateral hand. Manual dexterity averaged 70% efficiency as compared with normal standards defined according to age and sex. However, 55% of the patients, when stressed, used side-to-side pinch. It was noted that in those patients who used side-to-side pinch performance averaged 54% of normal standards, compared with 93% in patients who used tip-to-tip pinch for prehension.
Child↗
Bipolar latissimus dorsi transposition and functional neuromuscular stimulation to restore elbow flexion in an individual with C4 quadriplegia and C5 denervation.
A bipolar latissimus dorsi transposition was performed on a 17-year-old male patient with a C4 spinal cord injury and complete peripheral denervation at C5. Electrical stimulation of the paralyzed but excitable latissimus dorsi provided elbow flexion that could not be achieved with the paralyzed and denervated elbow flexors. The muscle was attached from the coracoid to the ulna allowing the elbow to be flexed with the forearm and wrist maintained in the neutral position. Following a 6-week immobilization period, the transposed muscle was exercised daily with intramuscular stimulation to increase both strength and endurance. By the fourth month after surgery, the subject could control elbow flexion proportionally with contralateral shoulder elevation using a shoulder position transducer. Functionally, the subject was able to use the neuroprosthetic system to bring his hand to his mouth and feed himself with the aid of a universal cuff and a support to stabilize the shoulder.
Adolescent↗
A 23-kilodalton protein, distinct from BvgA, expressed by virulent Bordetella pertussis binds to the promoter region of vir-regulated toxin genes.
Bordetella pertussis coordinately regulates expression of its virulence factors in response to changing environmental conditions. These factors include pertussis toxin, adenylate cyclase toxin, and the filamentous hemagglutinin (FHA). The vir (or bvg) locus has been shown genetically to be required for this coordinate regulation. We have attempted to study the biochemical basis for coordinate regulation. DNA promoter deletion studies from other laboratories have shown that two tandem 20-bp repeats -157 to -117 bp upstream from the pertussis toxin promoter are essential for transcription. A similar 20-bp tandem repeat was found at the same site in the upstream region of the adenylate cyclase toxin promoter but is not present in the FHA or vir promoter region. Gel retardation revealed protein from virulent strains (able to express the virulence genes) but not from avirulent strains (unable to express the virulence genes) bound to the promoter region of the pertussis toxin gene, and this binding could be abolished by competition with an excess of oligonucleotides corresponding to either tandem repeat. The protein was determined to be 23 kDa by Southwestern (DNA-protein) analysis and could bind to either 20-bp oligonucleotide from the pertussis toxin promoter and either 20-bp oligonucleotide from the adenylate cyclase toxin promoter. BvgA, a 23-kDa protein encoded in the vir locus, has been reported to bind to a 14-bp inverted repeat in the FHA promoter which is not present in the pertussis toxin or adenylate cyclase promoter. We could not demonstrate binding of BvgA to the pertussis toxin promoter region. These data suggest that we have identified a second 23-kDa protein, distinct from BvgA but regulated by the vir operon, that binds to DNA sequences required for transcription of some, but not all, vir-regulated genes.
Adenylate Cyclase Toxin↗
Bordetella pertussis adenylate cyclase toxin and hemolytic activities require a second gene, cyaC, for activation.
In these studies, the Bordetella pertussis adenylate cyclase toxin-hemolysin homology to the Escherichia coli hemolysin is extended with the finding of cyaC, a homolog to the E. coli hlyC gene, which is required for the production of a functional hemolysin molecule in E. coli. Mutations produced in the chromosome of B. pertussis upstream from the structural gene for the adenylate cyclase toxin revealed a region which was necessary for toxin and hemolytic activities of the molecule. These mutants produced the 216-kDa adenylate cyclase toxin as determined by Western blot (immunoblot) analysis. The adenylate cyclase enzymatic activities of these mutants were equivalent to that of wild type, but toxin activities were less than 1% of that of wild type, and the mutants were nonhemolytic on blood agar plates and in in vitro assays. The upstream region restored hemolytic activity when returned in trans to the mutant strains. This genetic complementation defined a gene which acts in trans to activate the adenylate cyclase toxin posttranslationally. Sequence analysis of the upstream region defined an open reading frame with homology to the E. coli hlyC gene. In contrast to E. coli, this open reading frame is oriented oppositely from the adenylate cyclase toxin structural gene.
Adenylyl Cyclases↗
Adenylate cyclase toxin is critical for colonization and pertussis toxin is critical for lethal infection by Bordetella pertussis in infant mice.
Proliferation of Bordetella pertussis in the lungs of infant mice challenged by the intranasal route was examined. The bacteria rapidly proliferated in the lungs of mice challenged with a sublethal dose of a wild-type strain (BP338) or a filamentous hemagglutinin mutant (BPM409) from 500 at day 0 to 10(7) at day 15. The infection cleared in about 40 days. Pertussis toxin-deficient mutant BP357 gave a similar profile; however, the number of bacteria recovered was slightly reduced, suggesting that pertussis toxin is not essential for bacterial growth in the lungs. In contrast, adenylate cyclase toxin mutant BP348 was rapidly cleared from the lungs, with no viable bacteria remaining 10 days postchallenge, suggesting that the adenylate cyclase toxin is a colonization factor required for the bacteria to initiate infection.
Adenylyl Cyclases↗
Comparison between intermittent (spring-loaded) and continuous closed suction drainage of orthopedic wounds: a controlled clinical trial.
A randomized prospective trial of a continuous vacuum system (VariDyne) and an intermittent spring type system (Hemovac) was conducted in 126 consecutive orthopedic surgical wounds between February 1988 and October 1988 in which postoperative suction drainage was required. Comparison between the two groups showed a statistically significant difference among total drainage removed by the vacuum units and wound drainage into the dressing following drain removal. Hip and knee arthroplasty patients receiving continuous vacuum suction experienced a greater average drainage volume and better wound healing than those receiving the spring-loaded device. Overall, all wounds which utilized continuous vacuum drained less serosanguinous or serous fluid than those wounds utilizing the intermittent system following drain removal. A clear advantage to using a continuous vacuum suction device over an intermittent spring-loaded device is seen with respect to hematoma evacuation, wound drainage, wound healing, and possible complications.
Adult↗
Lethal infection by Bordetella pertussis mutants in the infant mouse model.
Different aspects of lethal infection of infant mice with Bordetella pertussis were examined. Mutants deficient in vir-regulated genes were tested for the ability to cause a lethal infection in the infant mouse model. Adenylate cyclase toxin-hemolysin and pertussis toxin were required to cause a lethal infection at low doses. Mixed infection caused by challenging the mice with an equal number of pertussis toxin and adenylate cyclase toxin-hemolysin mutants at a dose at which neither alone was lethal was also unable to cause a lethal infection. Production of the filamentous hemagglutinin and the dermonecrotic toxin was not required to cause a lethal infection. Nine other mutants in vir-regulated genes whose phenotypes have yet to be determined were also tested. Only two of these mutants were impaired in the ability to cause a lethal infection. Expression of fimbriae does not appear to affect the dose required to cause a lethal infection; however, fimbrial expression was correlated with the later stages of a nonlethal, persistent infection. Growth of the bacteria in MgSO4, a condition which reversibly suppresses expression of the genes required for virulence, did not alter the ability of the bacteria to cause a lethal infection. Auxotrophic mutants deficient in leucine biosynthesis were as virulent as the parental strain; however, mutants deficient in methionine biosynthesis were less virulent. A B. parapertussis strain was much less effective in promoting a lethal infection than any of the wild-type B. pertussis strains examined. A persistent infection in the lungs was observed for weeks after challenge for mice given a sublethal dose of B. pertussis, and transmission from infected infants to the mother was never observed.
Adenylate Cyclase Toxin↗