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P Guerry

Publications and source records attributed to P Guerry.

At least 55 records · Page 3Linked to original sources
PubMed1990

Genomic organization and expression of Campylobacter flagellin genes.

Campylobacter coli VC167, which undergoes an antigenic flagellar variation, contains two full-length flagellin genes, flaA and flaB, that are located adjacent to one another in a tandem orientation and are 91.5% homologous. The gene product of flaB, which has an Mr of 58,946, has 93% sequence homology to the gene product of flaA, which has an Mr of 58,916 (S. M. Logan, T. J. Trust, and P. Guerry, J. Bacteriol. 171:3031-3038, 1989). Mutational analyses and primer extension experiments indicated that the two genes are transcribed under the control of distinct promoters but that they are expressed concomitantly in the same cell, regardless of the antigenic phase of flagella being produced. The flaA gene, which was expressed at higher levels than the flaB gene in both phases, was transcribed from a typical sigma 28-type promoter, whereas the flaB promoter was unusual. A mutant producing only the flaB gene product did not synthesize a flagellar filament and was nonmotile. Southern blot analysis indicated that flagellar antigenic variation involves a rearrangement of flagellin sequence information rather than the alternate expression of the two distinct genes.

Amino Acid Sequence↗
PubMed1989

In vivo antigenic variation of Campylobacter flagellin.

Campylobacter coli VC167 cells producing either antigenic phase 1 (P1) or phase 2 (P2) flagellins (as determined by characteristic protein and DNA patterns) were used to infect rabbits by the removable intestinal tie-adult rabbit diarrhea (RITARD) procedure. Rabbits infected with P2 cells shed predominantly P2 cells throughout the infection; in rabbits infected with P1 cells, a transition of fecal isolates from P1 to P2 was observed.

Animals↗
PubMed1989

Evidence for posttranslational modification and gene duplication of Campylobacter flagellin.

A gene encoding a flagellin protein of Campylobacter coli VC167 has been cloned and sequenced. The gene was identified in a pBR322 library by hybridization to a synthetic oligonucleotide probe corresponding to amino acids 4 to 9 of the N-terminal sequence obtained by direct chemical analysis (S. M. Logan, L. A. Harris, and T. J. Trust, J. Bacteriol. 169:5072-5077, 1987). The DNA was sequenced and shown to contain an open reading frame encoding a protein with a molecular weight of 58,945 and a length of 572 amino acids. The deduced amino acid sequence was identical to the published N-terminal amino acid sequence of VC167 flagellin and to four internal regions whose partial sequences were obtained by direct chemical analysis of two tryptic and two cyanogen bromide peptides of VC167 flagellin. The C. coli flagellin protein contains posttranslationally modified serine residues, most of which occur within a region containing two 9-amino-acid repeating peptides separated by 34 unique amino acids. Comparisons with the sequences of flagellins from other bacterial species revealed conserved residues at the amino- and carboxy-terminal regions. Hybridization data suggest the presence of a second flagellin copy located adjacent to the first on the VC167 chromosome.

Amino Acid Sequence↗
PubMed1988

Cystic hypersecretory hyperplasia and cystic hypersecretory duct carcinoma of the breast. Pathology, therapy, and follow-up of 39 patients.

The study documented in this article was performed to define the clinical and morphologic features of cystic hypersecretory carcinoma (CHC) and cystic hypersecretory hyperplasia (CHH) of the breast. Both lesions are characterized by the formation of cystically dilated ducts containing a homogeneous eosinophilic secretion that resembles thyroid colloid. In most cases CHC features micropapillary intraductal carcinoma, occasionally giving rise to a high-grade, invasive carcinoma that is absent from CHH. Electron microscopy of the cystic component in one case of CHC showed ultrastructural characteristics of metabolically active cells, but few secretory granules. Twenty-nine patients with CHC were observed for up to 23 years. Twenty-five women who had intraductal carcinoma were well or died of other causes. Of the four patients who had invasive carcinoma, one died 9 months after being diagnosed as having systemic metastases, and the other three remained disease-free. Ten cases of CHH were reviewed; follow-up information was available for eight patients for up to 5 years. Six women were alive and well. One woman died of contralateral invasive carcinoma, and a second was well having had a modified radical mastectomy for a separate, coexisting intraductal carcinoma in the same breast. These findings indicate that intraductal CHC has the same low-grade clinical course as other forms of intraductal carcinoma. Because invasive carcinoma arising in this setting appears to be histologically high-grade, it is important to recognize and promptly treat the lesion while still in its in situ phase. Foci with the appearance of CHH may be found in CHC, but in this study progression from CHH to CHC was not observed. A thorough histological examination is needed to distinguish between CHC and CHH. Lesions judged to be CHH are adequately treated by wide excision. Additional long-term, follow-up studies will be necessary to define the precancerous potential of CHH.

Adult↗
PubMed1988

Genomic rearrangements associated with antigenic variation in Campylobacter coli.

Campylobacter coli and Campylobacter jejuni share a limited number of highly conserved DNA sequences with members of the family Enterobacteriaceae. One of these sequences was cloned from C. coli VC167, and the region of homology to the enteric sequences was determined to be confined to a 700-base-pair region. The DNA represented in this clone undergoes a programmed, reversible rearrangement in VC167 that is associated with flagellar antigenic variation.

Antigenic Variation↗
PubMed1987

Introduction of Shigella flexneri 2a type and group antigen genes into oral typhoid vaccine strain Salmonella typhi Ty21a.

For protection against dysentery caused by Shigella flexneri 2a, an in vivo-constructed recombinant plasmid with genes specifying the S. flexneri type and group antigens located near the pro (min 6) and his (min 44) chromosomal markers, respectively, was made and transferred to the galE Salmonella typhi strain Ty21a. Strain Ty21a carrying this recombinant plasmid was shown by immunological and biochemical analyses to express the S. flexneri 2a type and group antigens. Mice immunized with this vaccine strain were found to be protected against challenge with virulent S. flexneri 2a, but not significantly against S. typhi challenge, presumably because synthesis of the Shigella antigens interfered with expression of the typhoid antigens. Elimination of the recombinant plasmid from Ty21a allowed this strain to again express typical S. typhi O antigens. Mouse protection against both S. typhi and S. flexneri 2a challenges was achieved with a whole-cell vaccine mixture composed of equal parts of Ty21a and the Ty21a-S. flexneri 2a hybrid strain.

Administration, Oral↗
PubMed1987

Antigenic variation of Campylobacter flagella.

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of flagella dissociated from strains of Campylobacter coli and Campylobacter jejuni belonging to the heat-labile serogroup LIO 8 showed that some strains were capable of producing flagellin subunits of two different molecular weights (MrS), 59,500 and 61,500. Immunoelectron microscopy of cultures of the type strain of this serogroup, C. coli VC167, showed the presence of two flagellum filaments of different antigenic specificity. Epitopes on the surface of one of these flagella bound antibodies in LIO 8 typing antiserum, and Western blotting (immunoblotting) and immunoprecipitation showed that the flagellum was composed of flagellin of Mr 61,500. The other flagellum antigenic type did not bind LIO 8 antibodies but did possess serospecific epitopes which bound a second polyclonal antiserum, LAH2. This second antigenic flagellum type was composed of the Mr 59,500 flagellin. Cells producing either of the flagellum antigenic types serotyped as LIO 8, indicating that flagella composed of the Mr 61,500 flagellin do not carry the serological determinants for this serogroup. The ability of C. coli VC167 to produce these flagella of different subunit MrS was shown to represent a bidirectional antigenic variation. When measured in culture medium, the phase 1-to-phase 2 transition occurred at a rate of approximately 2.0 x 10(-5) per cell per generation, and the phase 2-to-phase 1 transition occurred at a rate of 1.2 x 10(-6) per cell per generation.

Antibodies↗
PubMed1986

Evaluation of a synthetic oligonucleotide probe for diagnosis of Plasmodium falciparum infections.

A radiolabeled synthetic oligonucleotide was evaluated as a diagnostic probe specific for Plasmodium falciparum using blood samples lysed directly on nitrocellulose filters. The probe technique successfully diagnosed malaria in experimentally infected chimpanzees that had 0.001% parasitemias (50 parasites/microliter) as determined by blood smears, and in 1 chimpanzee whose blood smear was negative, but whose blood was culture-positive for P. falciparum. In a double blind study of 50 patient samples from the Philippines, the probe results correlated well with blood smear results when the autoradiographs were read after 4-8 hr exposure. The results indicate that the oligonucleotide probe may be useful in the rapid and specific diagnosis of P. falciparum infection.

Animals↗
PubMed1985

Sequence of the immunodominant epitope for the surface protein on sporozoites of Plasmodium vivax.

Plasmodium vivax is one of the four malaria parasites that cause disease in humans. The structure of the immunodominant repeating peptide of the circumsporozoite (CS) protein of P. vivax was determined. A fragment of P. vivax DNA that encodes this tandemly repeating epitope was isolated by use of an oligonucleotide probe whose sequence is thought to be conserved in CS protein genes. DNA sequence analysis of the P. vivax clone indicates that the CS repeat is nine amino acids in length (Gly-Asp-Arg-Ala-Asp-Gly-Gln-Pro-Ala). The structure of the repeating region was confirmed with synthetic peptides and monoclonal antibodies directed against P. vivax sporozoites. This information should allow synthesis of a vaccine for P. vivax that is similar to the one being tested for P. falciparum.

Amino Acid Sequence↗
PubMed1985

Reversible expression of flagella in Campylobacter jejuni.

Campylobacter jejuni 81116 and A3249 undergo a bidirectional transition between flagellated (Fla+) and aflagellated (Fla-) phenotypes. When measured in culture medium, the Fla+----Fla- transition occurred at a rate of 3.1 X 10(-3) to 5.9 X 10(-3) per cell per generation, and the Fla- to Fla+ transition occurred at a rate of 4.0 X 10(-7) to 8.0 X 10(-7) per cell per generation. However, passage through a rabbit intestine markedly favored the Fla+ phenotype.

Adhesiveness↗
PubMed1984

Expression of lipopolysaccharide O antigen in Escherichia coli K-12 hybrids containing plasmid and chromosomal genes from Shigella dysenteriae 1.

The requirement for both plasmid and chromosomal genes in the biosynthesis of Shigella dysenteriae 1 lipopolysaccharide O antigen was demonstrated in Escherichia coli-Shigella hybrids. A 6-megadalton S. dysenteriae 1 plasmid, designated pWR23, was phenotypically tagged with the Tn3 ampicillin-resistance transposon. The tagged plasmid, designated pWR24, was transferred by transformation or conjugal mobilization to a rough E. coli K-12 recipient. Although the resultant hybrids were agglutinated in S. dysenteriae 1 antiserum, they did not remove all of the anti-Shiga agglutinins in absorption experiments. Modified lipid A core structure was detected in these hybrids, but Shiga O antigen was not expressed. When the his+ locus of the S. dysenteriae 1 chromosome was transferred by transduction to E. coli K-12 containing pWR24, complete Shiga O antigen was expressed. Lipopolysaccharide extracted from these hybrids was indistinguishable chemically, electrophoretically, and serologically from native S. dysenteriae 1 lipopolysaccharide.

Antigens, Bacterial↗
PubMed1983

[Psychodynamic understanding of anxiety].

Anxiety as a state of arousal--Is it the same thing in pathology as in the ordinary experience of every human being? The outward show of anxiety is evidently the same, but what exactly do we mean by anxiety? Anxiety is one of the less welcome sides of man's superiority over the animals, stemming from a consciousness of one's own being, the freedom to make choices about the future and to plan ahead, the need to develop one's own personality, to create an identity for oneself in an environment where the means for such self-fulfillment appear always to be insufficient. This existential anxiety becomes pathological through symptoms; it manifests a specific weakness for each psychopathological structure. There are two different, but not irreconcilable approaches to understanding the mechanisms of anxiety: one biodynamic , the other psychodynamic. These two approaches should complement rather oppose one another. Anxiety is the cry of a self in the process of becoming, it is expressed through language. Administration of an anti-anxiety drug has a biochemical impact, but this should not be sufficient in itself. When a doctor prescribes an anti-anxiety drug, he should always encourage the patient to talk. Drug therapy thus becomes a means rather than an end in itself: It enables the patient to find the words to express his anxiety.

Anti-Anxiety Agents↗
PubMed1978

Chromosomal superkiller mutants of Saccharomyces cerevisiae.

Yeast strains carrying a 1.5 X 10(6)-dalton double-stranded RNA in virus-like particles secrete a protein toxin which is lethal to strains not carrying this species of double-stranded RNA. We find that recessive mutations in any of four chromosomal genes result in the superkiller phenotype, i.e., increased secretion of killer toxin activity by strains carrying the killer genome. These genes are designated ski1 through ski4 (for superkiller), ski3 and ski4 are located on chromosome XIV, and ski1 is on chromosome VII. A ski1 mutation results in a decreased rate of cell growth. The kex1 and kex2 mutations are epistatic to each ski mutation.

Chromosome Mapping↗
PubMed1977

Isolation of cryptic plasmid deoxyribonucleic acid from Kanagawa-positive strains of Vibrio parahaemolyticus.

Twelve strains of Vibrio parahaemolyticus was examined for plasmid deoxyribonucleic acid (DNA) by dye-buoyant gradient centrifugation. Four Kanagawa-positive strains, all isolated from the same outbreak of gastroenteritis, contained multiple plasmid species of cryptic function. However, three Kanagawa-negative strains and five Kanagawa-positive strains were not found to contain demonstrable plasmid DNA. R-plasmids were successfully transferred from Escherichia coli to V. parahaemolyticus.

Conjugation, Genetic↗