bluuebunny/crossref_metadata_2025 huggingface dataset:
Primary Cultures of Female Swine Genital Epithelial Cells In Vitro: a New Approach for the Study of Hormonal Modulation of Chlamydia Infection
Authors: Guseva Natalia V. , Knight Stephen T. , Whittimore Judy D. , Wyrick Priscilla B.
Published: July 2003

Previous studies have demonstrated that female reproductive hormones influence chlamydial infection both in vivo and in vitro. Due to the reduced availability of human genital tissues for research purposes, an alternative hormone-responsive model system was sought to study chlamydial pathogenesis. Mature female swine eliminated from breeding programs were selected as the animals of choice because of the similarity of a sexually transmitted disease syndrome and sequelae in swine to a disease syndrome and sequelae found in humans, because of the near identity of a natural infectious chlamydial isolate from swine toChlamydia trachomatisserovar D from humans, and because a pig's epithelial cell physiology and the mean length of its estrous cycle are similar to those in humans. Epithelial cells from the cervix, uterus, and horns of the uterus were isolated, cultivated in vitro in Dulbecco's minimum essential medium-Hanks' F-12 (DMEM-F-12) medium with and without exogenous hormone supplementation, and analyzed forChlamydia suisS-45 infectivity. The distribution of chlamydial inclusions in swine epithelial cells was uneven and was influenced by the genital tract site and hormone status. This study confirmed that, like primary human endometrial epithelial cells, estrogen-dominant swine epithelial cells are more susceptible to chlamydial infection than are progesterone-dominant cells. Further, the more differentiated luminal epithelial cells were more susceptible to infection than were glandular epithelial cells. Interestingly, chlamydial growth in mature luminal epithelia was morphologically more active than in glandular epithelia, where persistent chlamydial forms predominated. Attempts to reprogram epithelial cell physiology and thereby susceptibility to chlamydial infection by reverse-stage, exogenous hormonal supplementation were unsuccessful. Freshly isolated primary pig epithelial cells frozen at −80°C in DMEM-F-12 medium with 10% dimethyl sulfoxide for several weeks can, after thawing, reform characteristic polarized monolayers in 3 to 5 days. Thus, primary swine genital epithelia cultured ex vivo appear to be an excellent cell model for dissecting the hormonal modulation of several aspects of chlamydial pathogenesis and infection.
Calprotectin, an Abundant Cytosolic Protein from Human Polymorphonuclear Leukocytes, Inhibits the Growth ofBorrelia burgdorferi
Authors: Lusitani Denise , Malawista Stephen E. , Montgomery Ruth R.
Published: July 2003

We previously showed that numerous polymorphonuclear leukocyte (PMN) granule components efficiently killBorrelia burgdorferi, the agent of Lyme disease. In addition, motile, granule-poor cytoplasts (U-Cyt) from human blood PMN can exert anti-Borreliaactivity against opsonizedB. burgdorferiindependently of oxidative mechanisms. Here we show that lysates of U-Cyt also possess anti-Borreliaactivity, a portion of which comes from the abundant cytosolic protein calprotectin. The anti-Borreliaactivity of U-Cyt lysates and recombinant calprotectin was partially or completely reversed by specific antibody to calprotectin and by Zn2+, a cation essential for the growth ofB. burgdorferiand known to inhibit the antimicrobial activity of calprotectin. Quantitative microscopic and regrowth assays revealed that calprotectin acted in a bacteriostatic fashion againstB. burgdorferi. We conclude that calprotectin, a potent bacteriostatic agent from a cell primarily recognized for its oxidative and granular antibacterial mechanisms, may play a modulatory role in infection by the Lyme spirochete, particularly at sites of acute inflammation.
SCID Mouse Model for Lethal Q Fever
Authors: Andoh Masako , Naganawa Takashi , Hotta Akitoyo , Yamaguchi Tsuyoshi , Fukushi Hideto , Masegi Toshiaki , Hirai Katsuya
Published: July 2003

Q fever, a worldwide zoonosis caused byCoxiella burnetii, has many manifestations in humans. Endocarditis is the most serious complication of Q fever. Animal models are limited to acute pulmonary or hepatic disease and reproductive disorders. An appropriate experimental animal model for Q fever endocarditis does not yet exist. In this study, severe combined immunodeficient (SCID) mice infected withC. burnetiishowed persistent clinical symptoms and died, whereas immunocompetent mice similarly infected became asymptomatic and survived. The SCID mice examined in this study had severe chronic lesions in their primary organs: the heart, lung, spleen, liver, and kidney. The heart lesions of the SCID mice were similar to those in humans with chronic Q fever endocarditis: they had focal calcification and expanded macrophages containingC. burnetii. The 50% lethal dose ofC. burnetiiin SCID mice was at least 108times less than that in immunocompetent mice. The SCID mouse is highly susceptible toC. burnetii, and the immunodeficiency of the host enhances the severity of Q fever. This animal model could provide a new tool for the study of chronic Q fever and Q fever in immunodeficient hosts.
Correlation of Acetate Catabolism and Growth Yield inStaphylococcus aureus: Implications for Host-Pathogen Interactions
Authors: Somerville Greg A. , Saïd-Salim Battouli , Wickman Jaala M. , Raffel Sandra J. , Kreiswirth Barry N. , Musser James M.
Published: July 2003

Recently, we reported that the prototypicalStaphylococcus aureusstrain RN6390 (a derivative of NCTC 8325) had significantly reduced aconitase activity relative to a diverse group ofS. aureusisolates, leading to the hypothesis that strain RN6390 has impaired tricarboxylic acid (TCA) cycle-mediated acetate catabolism. Analysis of the culture supernatant from RN6390 confirmed that acetate was incompletely catabolized, suggesting that the ability to catabolize acetate can be lost byS. aureus. To test this hypothesis, we examined the carbon catabolism of theS. aureusstrains whose genome sequences are publicly available. All strains catabolized glucose and excreted acetate into the culture medium. However, strains NCTC 8325 and N315 failed to catabolize acetate during the postexponential growth phase, resulting in significantly lower growth yields relative to strains that catabolized acetate. Strains NCTC 8325 and RN6390 contained an 11-bp deletion inrsbU, the gene encoding a positive regulator of the alternative sigma factor σBencoded bysigB. An isogenic derivative strain of RN6390 containing the wild-typersbUgene had significantly increased acetate catabolism, demonstrating that σBis required for acetate catabolism. Taken together, the data suggest that naturally occurring mutations can alter the ability ofS. aureusto catabolize acetate, a surprising discovery, as TCA cycle function has been demonstrated to be involved in the virulence, survival, and persistence of several pathogenic organisms. Additionally, these mutations decrease the fitness ofS. aureusby reducing the number of progeny placed into subsequent generations, suggesting that in certain situations a decreased growth yield is advantageous.
Induction of Antimicrobial Pathways during Early-Phase Immune Response toSalmonellaspp. in Murine Macrophages: Gamma Interferon (IFN-γ) and Upregulation of IFN-γ Receptor Alpha Expression Are Required for NADPH Phagocytic Oxidase gp91-Stimulated Oxidative Burst and Control of VirulentSalmonellaspp
Authors: Foster N. , Hulme S. D. , Barrow P. A.
Published: July 2003

The effect of gamma interferon (IFN-γ) on elevation of reactive oxygen species and the viability of virulent wild-type and avirulent mutants ofSalmonella entericaserovar Typhimurium andS. entericaserovar Infantis was studied in a murine macrophage cell line (J774.2 cells).S. entericaserovar Typhimurium 14028phoPand a rough lipopolysaccharide mutant ofS. entericaserovar Infantis 1326/28 (φr) (avirulent mutants) induced NADPH phagocytic oxidase gp91 (gp91phox) activity and a significant (P< 0.05) elevation of reactive oxygen species within 12 h without coculture with IFN-γ. This coincided with reduced survival ofS. entericaserovar Typhimurium14028phoPor stasis ofS. entericaserovar Infantis φr. Fluorometric studies indicated that expression of IFN-γ on infected J774.2 cells was not significantly (P> 0.05) elevated. However, studies with the virulentS. entericaserovar Typhimurium strains showed that a comparable level of control of bacterial numbers could only be achieved by coculture with IFN-γ. This coincided with significant upregulation of IFN-γ receptor alpha expression on the surface of J774.2 cells and was completely abolished byN-acetyl-l-cysteine captopril (an inhibitor of reactive oxygen species). Delay in reactive oxygen species induction due to a requirement for IFN-γ and upregulation of IFN-γ receptor alpha in macrophages infected with virulent salmonellae may result in greater dissemination of virulent salmonellae in host tissue.
Effect of Inactivation of the Arg- and/or Lys-Gingipain Gene on Selected Virulence and Physiological Properties of
Porphyromonas gingivalis
Authors: Grenier Daniel , Roy Sophie , Chandad Fatiha , Plamondon Pascale , Yoshioka Masami , Nakayama Koji , Mayrand Denis
Published: July 2003

Proteolytic enzymes produced by
Porphyromonas gingivalis
are thought to play critical roles in the pathogenesis of periodontitis. The aim of this study was to investigate the effect of gingipain cysteine proteinase gene inactivation on selected pathological and physiological functions of
P. gingivalis
. Our results showed that Arg- and Lys-gingipain activities are critical components for the efficient growth of
P. gingivalis
in human serum. However, when the serum was supplemented with peptides provided as pancreatic casein hydrolysate, the gingipains did not appear to be essential for growth. The effect of gingipain gene inactivation on the susceptibility of
P. gingivalis
to serum bactericidal activity was investigated using standardized human serum. The wild-type strain,
P. gingivalis
ATCC 33277, was largely unaffected by the bactericidal activity of human serum complement. On the other hand, mutants lacking Arg-gingipain A, Arg-gingipain B, or Lys-gingipain activity were susceptible to complement. Since gingipains are mostly located on the outer membrane of
P. gingivalis
, inactivation of the genes for these enzymes may modify cell surface properties. We showed that gingipain-deficient mutants differed in their capacities to assimilate radiolabeled amino acids, cause hemolysis, express adhesins, hemagglutinate, and form biofilms. Lastly, the gingipains, more specifically Arg-gingipains, were responsible for causing major cell damage to human gingival fibroblasts. In conclusion, our study indicated that, in addition to being critical in the pathogenic process, gingipains may play a variety of physiological roles in
P. gingivalis
, including controlling the expression and/or processing of virulence factors. Mutations in gingipain genes thus give rise to pleiotropic effects.
Induction of Parasite Growth-Inhibitory Antibodies by a Virosomal Formulation of a Peptidomimetic of Loop I from Domain III of
Plasmodium falciparum
Apical Membrane Antigen 1
Authors: Mueller Markus S. , Renard Annabelle , Boato Francesca , Vogel Denise , Naegeli Martin , Zurbriggen Rinaldo , Robinson John A. , Pluschke Gerd
Published: July 2003

Apical membrane antigen 1 (AMA-1) of
Plasmodium falciparum
is a leading candidate antigen for inclusion in a malaria subunit vaccine. Its ectodomain can be divided into three subdomains, each with disulfide bond-stabilized structures. Since the majority of antibodies raised against the ectodomain appear to recognize strain-specific epitopes in domain I, we attempted to develop a vaccine formulation which directs the immune response to a region that contains more conserved epitopes. Here we demonstrate that a virosomal formulation of a peptide that mimics the semiconserved loop I of domain III elicits parasite growth-inhibitory antibodies. A synthetic peptide comprising residues 446 to 490 of AMA-1 (AMA-1
446-490
) was conjugated through the N terminus to a derivative of phosphatidylethanolamine and the phosphatidylethanolamine-peptide conjugate was incorporated into immunopotentiating reconstituted influenza virosomes as a human-compatible antigen delivery system. Both cyclized and linear versions of the peptide antigen elicited antibodies which specifically bound to parasite-expressed AMA-1 in Western blotting with parasite lysates as well as in immunofluorescence assays with blood stage parasites. All 11 peptidomimetic-specific monoclonal antibodies generated were cross-reactive with parasite-expressed AMA-1. Antigen binding assays with a library of overlapping cyclic peptides covering the target sequence revealed differences in the fine specificity of these monoclonal antibodies and provided evidence that at least some of them recognized discontinuous epitopes. The two immunodominant epitopes comprised the conserved linear sequences K
459
RIKLN
464
and D
467
DEGNKKII
475
. A key feature of the synthetic vaccine formulation proposed here is the display of the peptide antigen in a native-like state on the surface of the virosome.
Growth, Development, and Gene Expression in a Persistent
Streptococcus gordonii
Biofilm
Authors: Gilmore Keeta S. , Srinivas Pravina , Akins Darrin R. , Hatter Kenneth L. , Gilmore Michael S.
Published: July 2003

A model for the protracted (30-day) colonization of smooth surfaces by
Streptococcus gordonii
that incorporates the nutrient flux that occurs in the oral cavity was developed. This model was used to characterize the biphasic expansion of the adherent bacterial population, which corresponded with the emergence of higher-order architectures characteristic of biofilms. Biofilm formation by
S. gordonii
was observed to be influenced by the presence of simple sugars including sucrose, glucose, and fructose. Real-time PCR was used to quantify changes in expression of
S. gordonii
genes known or thought to be involved in biofilm formation. Morphological changes were accompanied by a significant shift in gene expression patterns. The majority of
S. gordonii
genes examined were observed to be downregulated in the biofilm phase. Genes found to be upregulated in the biofilm state were observed to encode products related to environmental sensing and signaling.
Nonspecific Immunoglobulin M Binding and Chondroitin Sulfate A Binding Are Linked Phenotypes of
Plasmodium falciparum
Isolates Implicated in Malaria during Pregnancy
Authors: Creasey Alison M. , Staalsoe Trine , Raza Ahmed , Arnot David E. , Rowe J. Alexandra
Published: July 2003

Binding of immunoglobulin M (IgM) antibodies from normal human serum to the surface of
Plasmodium falciparum
-infected red blood cells (iRBC) has previously been demonstrated only in parasites that form rosettes with uninfected red cells. We show that natural, nonspecific IgM but not IgG, IgA, IgD, or IgE also binds to the surface of iRBC selected for adhesion to chondroitin sulfate A (CSA), a placental receptor for parasites associated with malaria in pregnancy. The protease sensitivity of IgM-binding appears to match that of CSA binding, suggesting that the two phenotypes may be mediated by the same parasite molecule. We also show that a wide range of mouse monoclonal antibodies of the IgM class bind nonspecifically to CSA-selected iRBC, an important consideration in the interpretation of immunological assays performed on these parasite lines.
Recombinant 56-Kilodalton Major Outer Membrane Protein Antigen of
Orientia tsutsugamushi
Shanxi and Its Antigenicity
Authors: Chen Wei-Jun , Niu Dong-Sheng , Zhang Xue-Ying , Chen Mei-Ling , Cui Hong , Wei Wen-Jin , Wen Bo-Hai , Chen Xiang-Rui
Published: July 2003

The gene encoding the 56-kDa protein of
Orientia tsutsugamushi
Shanxi was amplified by a nested PCR and cloned into the expression vector pQE30. The 56-kDa protein of
O. tsutsugamushi
Shanxi (Sxh56) was expressed as a fusion protein with the His
6
-binding protein of
Escherichia coli
by deleting the signal peptide-encoding sequence from the 5′ end of the open reading frame. The recombinant protein formed inclusion bodies when expressed in
E. coli
M15. The recombinant protein was examined for reactivity with mouse sera against three antigenic prototypes of
O. tsutsugamushi
by an immunoblot assay. The recombinant Sxh56 reacted only to polyclonal antiserum to
O. tsutsugamushi
Gilliam in an enzyme-linked immunosorbent assay (ELISA) and in an immunoblot assay. Recombinant Sxh56 was purified by Ni-nitrilotriacetic acid affinity chromatography and injected into mice to evaluate its ability to stimulate immune responses. High levels of immunoglobulin G and T-cell proliferation appeared in mice immunized with the recombinant protein. The recombinant Sxh56 was used in an ELISA to evaluate the ability of the method to detect antibodies to
O. tsutsugamushi
in human and animal sera. Thirty sera from mice infected with
O. tsutsugamushi
Gilliam or Shanxi and 55 sera from normal mice were detected in the ELISA with recombinant Sxh56, and the sensitivity and specificity were 96.67 and 100%, respectively. One hundred fifty-one positive sera and 412 negative sera to
O. tsutsugamushi
Gilliam were detected in an indirect immunofluorescence assay with the recombinant protein, and the sensitivity and specificity were 96.36 and 88.08%, respectively. These results strongly suggest that the recombinant Sxh56 is a suitable type-specific immunodiagnostic antigen and vaccine candidate.
Increased Protection against Pneumococcal Disease by Mucosal Administration of Conjugate Vaccine plus Interleukin-12
Authors: Lynch Joyce M. , Briles David E. , Metzger Dennis W.
Published: July 2003

Streptococcus pneumoniaeis a common cause of respiratory tract infections, its main entry route being the nasal mucosa. The recent development of pneumococcal polysaccharide conjugate vaccines has led to a dramatic improvement in protection against invasive disease in infants and children, but these vaccines have been found to be only 50 to 60% protective against bacterial carriage. In this study, we investigated the efficacy of intranasal (i.n.) conjugate vaccine delivery using interleukin-12 (IL-12) as a mucosal adjuvant. Immunized mice treated with IL-12 demonstrated increased expression of lung and splenic gamma interferon and IL-10 mRNAs; high levels of antibody, particularly serum immunoglobulin G2a (IgG2a) and respiratory IgA; and significantly increased opsonic activity. After intraperitoneal challenge with type 3 pneumococci, there was 75% survival of i.n. vaccinated mice compared to 0% survival of unvaccinated mice. In addition, after i.n. challenge with type 14 pneumococci, vaccinated mice possessed fewer bacterial colonies in the upper respiratory tract than unvaccinated mice. However, no significant difference in type 14 carriage was observed between vaccinated and unvaccinated groups following intramuscular vaccination, the typical route of vaccination in humans. Using mice with a genetic disruption in IgA expression, it was found that pneumococcus-specific IgA played a significant role in the clearance of bacteria from the upper respiratory tract. We conclude that i.n vaccination in the presence of IL-12 is able to enhance systemic and mucosal immune responses to pneumococci and efficiently protect against both invasive infection and bacterial carriage.
Proteins of the Rpf Family: Immune Cell Reactivity and Vaccination Efficacy against Tuberculosis in Mice
Authors: Yeremeev Vladimir V. , Kondratieva Tatiana K. , Rubakova Elvira I. , Petrovskaya Svetlana N. , Kazarian Konstantin A. , Telkov Miroslav V. , Biketov Sergej F. , Kaprelyants Arseny S. , Apt Alexander S.
Published: July 2003

It was shown recently thatMycobacterium tuberculosisexpresses five proteins that are homologous to Rpf (resuscitation promoting factor), which is secreted by growing cells ofMicrococcus luteus. Rpf is required to resuscitate the growth of dormantMicrococcus luteusorganisms, and its homologues may be involved in mycobacterial reactivation. Mycobacterial Rpf-like products are secreted proteins, which makes them candidates for recognition by the host immune system and anti-Rpf immune responses potentially protective against reactivated tuberculosis. Here we report that the Rpf protein itself and four out of five of its mycobacterial homologues, which were administered as subunit vaccines to C57BL/6 mice, are highly immunogenic. Rpf-like proteins elicit immunoglobulin G1 (IgG1) and IgG2a responses and T-cell proliferation and stimulate production of gamma interferon, interleukin-10 (IL-10), and IL-12 but not IL-4 or IL-5. Both humoral and T-cell responses against these antigens show a high degree of cross-reactivity. Vaccination of mice with Rpf-like proteins results in a significant level of protection against a subsequent high-dose challenge with virulentM. tuberculosisH37Rv, both in terms of survival times and mycobacterial multiplication in lungs and spleens.
Secreted Effector Proteins ofSalmonella entericaSerotype Typhimurium Elicit Host-Specific Chemokine Profiles in Animal Models of Typhoid Fever and Enterocolitis
Authors: Zhang Shuping , Adams L. Garry , Nunes Jairo , Khare Sangeeta , Tsolis Renée M. , Bäumler Andreas J.
Published: July 2003

Infection of bovine ligated loops with theSalmonella entericaserotype Typhimurium wild type but not asipA sopABDE2mutant resulted in fluid accumulation, polymorphonuclear cell infiltration, and expression of CXC chemokines, particularly GROα. None of thesesipA sopABDE2-dependent responses was observed in murine-ligated loops. The majority of GROα transcripts localized to bovine intestinal epithelium. Thus, different disease outcomes between mice (i.e., no diarrhea) and calves (i.e., diarrhea) may be due to differences insipA sopABDE2-dependent CXC chemokine gene expression in epithelial cells.
Both Interleukin-4 (IL-4) and IL-4 Receptor α Signaling Contribute to the Development of Hepatic Granulomas with Optimal Antileishmanial Activity
Authors: Stäger Simona , Alexander James , Carter K. Christine , Brombacher Frank , Kaye Paul M.
Published: July 2003

The roles of interleukin-4 (IL-4) and IL-13 in the regulation of immunity toLeishmania donovaniinfection are still poorly understood. Here we show that the increased parasite load observed in IL-4−/−and IL-4 receptor α−/−mice correlates with retarded granuloma maturation and antileishmanial activity and that the increased parasite load observed in IL-4 receptor α−/−mice correlates with increased NOS2 expression and decreased serum gamma interferon levels. IL-4 and IL-13 appear to play little role in regulating collagen deposition inL. donovani-induced granulomas.
Antigen-Specific Immunoglobulin A Antibodies Secreted from Circulating B Cells Are an Effective Marker for Recent Local Immune Responses in Patients with Cholera: Comparison to Antibody-Secreting Cell Responses and Other Immunological Markers
Authors: Qadri Firdausi , Ryan Edward T. , Faruque A. S. G. , Ahmed Firoz , Khan Ashraful Islam , Islam M. Monirul , Akramuzzaman Syed M. , Sack David. A. , Calderwood Stephen B.
Published: July 2003

Gut-derived lymphocytes transiently migrate through the peripheral circulation before homing back to mucosal sites and can be detected using an ELISPOT-based antibody secreting cell (ASC) assay. Alternatively, transiently circulating lymphocytes may be cultured in vitro, and culture supernatants may be assayed for antigen-specific responses (antibody in lymphocyte supernatant [ALS] assay). The ALS assay has not been validated extensively in natural mucosal infection, nor has the ALS response been compared to the ASC assay and other cholera-specific immunological responses. Accordingly, we examined immune responses in 30 adult patients with acute cholera in Bangladesh, compared with 10 healthy controls, measuring ALS-immunoglobulin A (IgA), ASC-IgA, and serum and fecal IgA responses to two potent
Vibrio cholerae
immunogens, the nontoxic B subunit of cholera toxin (CtxB) and lipopolysaccharide (LPS) and a weaker
V. cholerae
immunogen, the mannose-sensitive hemagglutinin (MSHA). We found significant increases of anti-CtxB, anti-LPS, and anti-MSHA IgA in supernatants of lymphocytes cultured 7 days after onset of cholera using the ALS assay. We found that ALS and ASC responses correlated extremely well; both had comparable sensitivities as the vibriocidal responses, and both procedures were more sensitive than fecal IgA measurements. An advantage of the ALS assay for studying mucosal immune responses is the ability to freeze antibodies in supernatants for subsequent evaluation; like the ASC assay, the ALS assay can distinguish recent from remote mucosal infection, a distinction that may be difficult to make in endemic settings using other procedures.
Major Histocompatibility Complex-Dependent Susceptibility toCryptococcus neoformansin Mice
Authors: McClelland Erin E. , Granger Donald L. , Potts Wayne K.
Published: July 2003

To evaluate the role of major histocompatibility complex (MHC) genes in the resistance toCryptococcus neoformans, we conducted infection experiments in MHC-congenic strains of mice. Significant MHC-dependent susceptibility differences were found among homozygotes and heterozygotes. This study is the first experimental demonstration of MHC-dependent susceptibility toC. neoformansinfections in mice and indicates that MHC genes can be important in host resistance.
Molecular Characterization of thesucBGene Encoding the Immunogenic Dihydrolipoamide Succinyltransferase Protein ofBartonella vinsoniisubsp.berkhoffiiandBartonella quintana
Authors: Gilmore, Robert D. , Carpio Amber M. , Kosoy Michael Y. , Gage Kenneth L.
Published: July 2003

Members of the genusBartonellahave historically been connected with human disease, such as cat scratch disease, trench fever, and Carrion's disease, and recently have been recognized as emerging pathogens causing other clinical manifestations in humans. However, because little is known about the antigens that elicit antibody production in response toBartonellainfections, this project was undertaken to identify and molecularly characterize these immunogens. Immunologic screening of aBartonella vinsoniisubsp.berkhoffiigenomic expression library with anti-Bartonellaantibodies led to the identification of thesucBgene, which encodes the enzyme dihydrolipoamide succinyltransferase. Antiserum from a mouse experimentally infected with liveBartonellawas reactive against recombinant SucB, indicating the mounting of an anti-SucB response following infection. Antigenic cross-reactivity was observed with antiserum against otherBartonellaspp. Antibodies againstCoxiella burnetti,Francisella tularensis, andRickettsia typhialso reacted with our recombinantBartonellaSucB. Potential SucB antigenic cross-reactivity presents a challenge to the development of serodiagnostic tests for other intracellular pathogens that cause diseases such as Q fever, rickettsioses, brucelloses, tularemia, and other bartonelloses.
Cell Surface Antigens of
Mycoplasma
Species Bovine Group 7 Bind to and Activate Plasminogen
Authors: Bower Kylie , Djordjevic Steven P. , Andronicos Nicholas M. , Ranson Marie
Published: July 2003

Mycoplasma
species bovine group 7 bound plasminogen at the cell surface in a lysine-dependent manner. Cell-bound plasminogen was rapidly activated to plasmin by exogenous urokinase, and this activity was associated with plasminogen binding capacity. Binding assays using plasminogen modified with a trifunctional cross-linking agent revealed several binding proteins.
Continuous tracking of the Australian National Tobacco Campaign: advertising effects on recall, recognition, cognitions, and behaviour
Authors: Donovan R J , Boulter J , Borland R , Jalleh G , Carter O
Published: July 2003

Objectives:To relate Australian National Tobacco Campaign advertising to outcome measures such as smokers’ awareness of and reaction to the campaign, and indicators of interest in smoking cessation.

Design:Continuous tracking was used to survey random cross sectional samples of the target audience via telephone interviews. Baseline measures were collected preceding each advertising phase, whereafter subjects were interviewed on a weekly basis for the entire period of each phase. Changes in outcomes could thus be inferred on a weekly basis allowing variations in advertising intensity to be monitored for effect. Three phases were evaluated variously in Melbourne, Sydney, and Adelaide.

Subjects:A total of 9033 subjects aged 18–40 years were interviewed. Age and sex of the sample were evenly distributed.

Results:In general, it was found that the greater the media weight, the greater the recall and recognition mediated by the message of the advertisement and the creative execution—advertisements with a clear figure ground executional format appeared more memorable than those without, and health effects advertisements were more memorable than those encouraging calls to a quitline. The relationship between various communication effects and media weight was limited by the confounding of prior activities in two of the phases.

Conclusions:Advertisements with clear figure ground executional formats and those illustrating health effects of smoking have high memorability. Future campaigns that are continuously tracked are recommended to systematically vary media weight, flighting schedules, and advertisement type, so as to maximise information about these variables and their interactions.
Cloning and heterologous expression of early genes in gibberellin and steviol biosynthesis via the methylerythritol phosphate pathway in Stevia rebaudiana
Authors: Totté Nicole , Ende Wim Van den , Van Damme Els JM , Compernolle Frans , Baboeuf Ilse , Geuns Jan MC
Published: July 2003

The ent-kaurene skeleton of chloroplast diterpene glycosides, which are produced in large quantities in the leaves of Stevia rebaudiana Bertoni, is formed via the recently discovered 2-C-methyl-D-erythritol 4-phosphate pathway. The enzymes catalyzing the first two steps of this pathway, 1-deoxy-D-xylulose-5-phosphate synthase (DXS) and 1-deoxy-D-xylulose-5-phosphate reductoisomerase (DXR) were characterized. Using reverse transcriptase-PCR, the dxs and dxr cDNAs were cloned, which comprise ORFs of 2148 and 1422 nucleotides, respectively. The cDNA-derived amino acid sequences for DXS and DXR contain 716 and 474 residues, encoding polypeptides of about 76.6 and 51 kDa, respectively. DXS and DXR from Stevia both contain an N-terminal plastid targeting sequence and show high homology to other known plant DXS and DXR enzymes. Furthermore, we demonstrated through heterologous expression in Escherichia coli that the cloned cDNAs encode functional proteins.Key words: Stevia rebaudiana Bertoni, Asteraceae, isoprenoids, 2-C-methyl-D-erythritol 4-phosphate pathway, 1- deoxy-D-xylulose-5-phosphate synthase, 1-deoxy-D-xylulose-5-phosphate reductoisomerase.
Fusarium verticillioides induction of maize seed rot and its control
Authors: Yates I E , Arnold J W , Hinton D M , Basinger W , Walcott R R
Published: July 2003

Experimental evidence is lacking to demonstrate whether Fusarium verticillioides (synonym = Fusarium moniliforme J. Sheld.; teleomorph = Gibberella fujikuroi (Sawada) Ito in Ito & K. Kimura, mating population A) functions as a causative agent or an opportunistic invader in seed (caryopsis) rot of maize (Zea mays L.). Previous researchers have isolated this fungus, along with many other microorganisms, from seed collected in the field long after rot commenced. The current investigations used an isolate of F. verticillioides transformed with a selectable marker and a reporter gene to inoculate previously disinfected maize seed. Seed rot developed, and F. verticillioides containing the introduced genes was isolated from inoculated, but not noninoculated, seed. Efficacy of Plantpro-45, an agent with an iodine-based active ingredient (a.i.), was analyzed for controlling growth of F. verticillioides from conidia and inoculated maize seed. A solution containing <10 µg a.i./mL inhibited growth of conidia suspended for <30 s. Furthermore, seed rot was controlled without diminishing seedling survival at 10 mg a.i./kg maize seed. Thus, F. verticillioides can function as the causative agent of maize seed rot and can be suppressed and (or) controlled at the postinfection stage with Plantpro-45.Key words: mycotoxin, reporter gene, germination, iodine.
Rates of peat accumulation during the postglacial period in 32 sites from Alaska to Newfoundland, with special emphasis on northern Minnesota
Authors: Gorham Eville , Janssens Joannes A , Glaser Paul H
Published: July 2003

We examined long-term rates of dry peat accumulation in 32 14C-dated cores from poor fens in Alaska, to bogs and fens in midcontinental North Dakota and Minnesota, to oceanic bogs in Maine and the Atlantic Provinces of Canada. Sites along this belt transect exhibit mostly linear relationships between cumulative mass and age. Long-term rates of peat accumulation range from 16 to 80 g·m2·year1, with a median rate of 47 g·m2·year1 and a mean rate of 50 g·m2·year1. Rate of accumulation is inversely correlated with mean annual precipitation, but is not correlated with the area of the peat basin, basal age, or mean annual temperature. Four of the five highest rates are from relatively dry midcontinental locations in North Dakota and Minnesota; the other is for a coastal site in Newfoundland. The two lowest rates are from extremely rainy sites on Pleasant Island in the Alaskan panhandle. Individual accumulation rates between adjacent dates are quite variable within the peat cores, and across the transect, they do not correlate significantly with immediately previous rates. The same is true of the four sites with the greatest numbers of dates. There is a small but significant negative correlation within the Red Lake Peatland.Key words: bog, fen, mire, North America, peatland.
Paired arbuscules in the Arum-type arbuscular mycorrhizal symbiosis with Linum usitatissimum
Authors: Dickson Sandy , Schweiger Peter , Smith F Andrew , Söderström Bengt , Smith Sally
Published: July 2003

Experiments were conducted to investigate the "paired" arbuscules characteristic of Arum-type mycorrhizal colonization in Linum usitatissimum L. The development and senescence of arbuscular structures were followed in a time course study. Roots were freeze-sectioned longitudinally and mycorrhizal structures visualized using nitroblue tetrazolium, a vital stain to indicate metabolically active arbuscules and intercellular hyphae, followed by acid fuchsin counterstaining. Arbuscules were imaged using laser scanning confocal microscopy. The volume and surface area of each arbuscule of a developing paired structure were measured using three-dimensional imaging software. Arbuscules occurred in pairs in adjacent cortical cells arising from a single, radial intercellular hypha. These "paired" arbuscules often appeared to be at different developmental stages. Logistic regression and measurement of surface area indicated that there was a delay in initiation of the second arbuscule.Key words: Arum-type arbuscular mycorrhiza, double staining, metabolic activity, morphology, confocal microscopy, Linum usitatissimum.
Dactylella pseudoclavata sp. nov., a new nematode-trapping fungus
Authors: Miao Zuo-Qing , Liu Xing-Zhong , Li Shi-Dong , He Mei-Xian
Published: July 2003

Dactylella pseudoclavata sp. nov., a new fungal species, isolated from juveniles of Meloidogyne incognita, is described. The fungus produces obclavate, 01 septate conidia with round distal ends and bases shaped like bottlenecks. The simple, separated, and occasionally branched conidiophores bear 14 conidia at the apex. The fungus also produces three-dimensional adhesive networks, which trap nematodes. The fungus closely resembles Dactylella arcuata, Dactylella clavata, Dactylella crassa, Dactylella cylindrospora, Dactylella huisuniana, Dactylella submersa, Dactylella arrhenopa, and Arthrobotrys flagrans, but is distinguished by its conidial shape and size, septa number, and trap type.Key words: Dactylella pseudoclava sp. nov., nematode, nematophagous fungus.
A transplant experiment on the factors preventing lichen colonization of oak bark in southeast England under declining SO2 pollution
Authors: Batty K , Bates J W , Bell J NB
Published: July 2003

To investigate the factors responsible for limited lichen recolonization on oak with declining SO2 concentrations, Parmelia caperata (L.) Ach. and Parmelia saxatilis (L.) Ach. were transplanted to five stations along a transect running from central London (U.K.) into the surrounding countryside. Healthy thalli were transplanted onto young and mature Quercus robur L. (pedunculate oak) and Betula pendula Roth (silver birch), and some were moved with their original bark attached to investigate the importance of bark acidification. Relative growth rates and visible injury were monitored over 2 years, along with concentrations of atmospheric SO2 and NO2, measured using diffusion tube samplers and bark chemistry. SO2 concentrations were low in central London in comparison with the situation in previous decades, but they remain sufficiently high to harm the most sensitive lichens. NO2 concentrations increased sharply on approaching London, and levels were higher in winter than in summer. Bark pH was lower in mature oak than in birch or young oak at the two innermost stations, and levels of bark Mg also declined in London. Transplants of P. caperata survived on birch and young oak at all transect stations except Hyde Park, whereas P. saxatilis failed to grow over a wider range of the transect stations. We conclude that modest SO2 levels, interacting with low bark pH, still inhibit recolonization of oaks by P. caperata in central London. Parmelia saxatilis, in addition, appears to be limited by another factor such as the high NO2 concentrations that now characterize urban and suburban London, rather than through an inherently poor dispersal potential.Key words: atmospheric pollution, bark acidification, epiphytic lichens, NO2, recolonization, SO2.
Export patterns of 14C-assimilates from source leaves of C3, C3C4 intermediate, and C4 Panicum and Flaveria species during light and dark periods
Authors: Leonardos Evangelos Demosthenes , Grodzinski Bernard
Published: July 2003

Source leaves of Panicum and Flaveria C3, C3C4 intermediate, and C4 species were fed 14CO2 in the mid-afternoon. Immediate export, calculated when isotopic equilibrium existed between 14CO2 and the 14C translocates, was compared with 14C export during the feed period, and both were compared with subsequent 14C export of primary reserves during daytimenighttime chase periods. Sugars and starch supported export in all species. In addition, regardless of differences in partitioning into starch and sugars during labelling, similar photosynthesis, immediate export, and daily export occurred in some Panicum C4 species. Within both genera, C4 types fixed and exported the most carbon. The Panicum "type I" C3C4 intermediates behaved in an "intermediate" manner with respect to both export during photosynthesis and daily. In contrast, compared with C3 and C4 species within the Flaveria, "type II" C3C4 intermediates had the lowest initial export during the feed period and total 14C export by the next morning. In spite of the plasticity in carbohydrate storage, export in all species was greater in the light than in the dark. Interestingly, daily 14C export correlated better with immediate export rates than with photosynthesis or other parameters of leaf function.Key words: C export, C partitioning, C3C4 intermediates, Flaveria, Panicum, photosynthesis.
Current insights into the development, structure, and chemistry of the endodermis and exodermis of roots
Authors: Ma Fengshan , Peterson Carol A
Published: July 2003

The endodermis and exodermis are the inner- and outermost cortical layers, respectively, of a root. Both are characterized by the development of Casparian bands in their anticlinal walls. Endodermal Casparian bands normally appear within 10 mm of the root tip, while exodermal Casparian bands are typically deposited farther from the tip. All Casparian bands contain the biopolymers lignin and suberin, allowing the endodermis and exodermis to serve as filtration sites for the passive movement of ions between the soil solution and the stele. Later in development, suberin lamellae are frequently deposited as secondary walls, which will reduce the transmembrane transport of ions and water. In some species, tertiary walls are also formed; their main function is postulated to be mechanical support of the root. Recent research with fluorescence and electron microscopy has revealed some important details of development and structure of these wall modifications. Further, chemical analyses of enzymatically isolated wall modifications have shown the chemical basis for the endodermis and exodermis as apoplastic barriers. Studies of Arabidopsis at the molecular level are shedding light on the genetic control of endodermal morphogenesis. In contrast, molecular aspects of exodermal development are totally unknown. Future work will benefit from a combined molecular and biochemical approach to the endodermis and exodermis.Key words: Casparian band, endodermis, exodermis, lignin, molecular biology, suberin, suberin lamella, tertiary wall.
Carbon dynamics of pristine and hydrologically modified fens in the southern Rocky Mountains
Authors: Chimner Rodney A , Cooper David J
Published: July 2003

We measured water table levels, above- and below-ground plant production, and CO2and CH4emissions for five fens in Rocky Mountain National Park, Colorado, to determine whether a water diversion project was adversely affecting carbon cycling. Two fens were located beneath the water diversion, and three fens were located in an adjacent pristine watershed. The diversion lowered water table levels in one fen, while the other fen was not hydrologically modified. Total NPP (net primary production) for all sites ranged from 130 to 316 g C·m2·year1, with a mean of 217 g C·m2·year1, and belowground NPP accounted for ~60% of the total. Maximum CO2emissions for pristine fens ranged between 170 and 273 mg CO2-C·m2·h1, with annual emissions of 230388 g CO2-C·m2·year1. However, the hydrologically modified fen had maximum CO2emissions of 457 mg CO2-C·m2·h1and had an annual flux of 573 g CO2-C·m2·year1. Maximum CH4emissions ranged from 3 to 25 mg CH4-C·m2·h1, with annual emissions of 961 g CH4-C·m2·year1. The water diversion structure lowered water tables, increased CO2, decreased CH4and NPP, and resulted in the site likely becoming a net source of carbon.Key words: peatlands, fens, CO2, CH4, hydrology, Rocky Mountains, Rocky Mountain National Park, plant production.
Comparative analysis of the sexual phase ofPhanerophlebia(Dryopteridaceae) in Mexico
Authors: Mendoza-Ruiz Aniceto , Pérez-García Blanca
Published: July 2003

A comparative analysis is presented of the spore morphology, germination pattern, and prothallial development of the sexual phase of seven species in the fern genus Phanerophlebia C. Presl. Gametophyte development was studied from samples grown both on agar and soil. Spores are monolete, ellipsoid, with light brown to dark brown perine; the germination pattern is Vittaria-type and the prothallial development is Aspidium-type in all of the species. The gametangia are of the type typical for leptosporangiate ferns. Gametophytes of all species initially become female, then bisexual. Differences among species include spore germination time (612 days), shape of the gametophytes (spatulatecordiform to cordiformreniform, with smooth to very irregular margins), development time of trichomes (1224 days), and appearance of gametangia (40200 days). Some species develop the first leaves of the sporophytes after 200 days. Results are contrasted with previously published reports on gametophyte development in Arachniodes Blume, Cyrtomium C. Presl, Didymochlaena Desv., Dryopteris Adans, Olfersia Raddi, Polystichum Roth, and Stigmatopteris C. Chr.Key words: Dryopteridaceae, fern gametophyte, Mexico, morphogenesis, Phanerophlebia, sexual phase.
Vegetative storage proteins in the tropical tree Swietenia macrophylla: seasonal fluctuation in relation to a fundamental role in the regulation of tree growth
Authors: Tian Wei-Min , Wu Ji-Lin , Hao Bing-Zhong , Hu Zheng-Hai
Published: July 2003

The protein-storing cells in Swietenia macrophylla King were investigated. They were found to be of the Populus type, i.e., ordinary parenchyma cells containing both vacuole protein inclusion and starch grains. Vegetative storage proteins with molecular masses of 18 and 21 kDa were separated by SDSPAGE (sodium dodecyl sulfate  polyacrylamide gel electrophoresis). Immunoblotting with the 21-kDa protein antiserum showed that the 18- and 21-kDa proteins shared common epitopes. The 21-kDa protein and presumably the 18-kDa protein were demonstrated by immunogold labeling to be the main components of the vacuole protein inclusion of the protein-storing cells. At the late stage of an annual growth cycle, vegetative storage proteins were found in the branchlets, trunk, large roots, and small roots. They were stored in large amounts in the secondary phloem of these organs and also in the secondary xylem of the terminal branchlets and small roots. In a new growth cycle, the consumption of the previously accumulated vegetative storage proteins began in the terminal branchlets of the last growth cycle. The vegetative storage proteins in the branchlets were exhausted completely when the new shoot leaves matured, while the storage proteins in the trunk and large roots had no detectable changes in abundance. On the other hand, the tree started to accumulate the two proteins in the stem of the new shoots as early as 1 week after the new shoot leaves matured. These results suggested that the previously accumulated vegetative storage proteins were used for new shoot growth and cambial activity in preference to the newly assimilated nitrogen and that vegetative storage proteins existed in considerable amounts in the stems throughout an annual growth cycle. This seasonal fluctuating pattern of vegetative storage proteins in the whole tree may be an important mechanism by which the tree regulates its growth.Key words: vegetative storage proteins, nitrogen metabolism, Populus-type of protein-storing cells, tropical hardwoods, Swietenia macrophylla King.
Elements regulatingAGAMOUSexpression are conserved betweenArabidopsis thaliana,Brassica napus, andLinum usitatissimum
Authors: Pylatuik Jeffrey D , Cross Rebecca H , Davis Arthur R , Bonham-Smith Peta C
Published: July 2003

To investigate the functional conservation of cis regulatory elements controlling AGAMOUS (AG) expression, we placed the promoter region of AG from Arabidopsis thaliana into a close relative, Brassica napus, and a distantly related species, Linum usitatissimum, and analyzed the subsequent expression patterns in each species. Spatially, the expression patterns in all three species were marginally similar, in that expression was confined primarily to the reproductive organs and nectarium. Within organs however, tissue-specific expression patterns were not conserved between species. Unlike Arabidopsis, the transgenic AG cis elements did not express in the ovules of B. napus and L. usitatissimum. Temporally, the pattern of AG cis-element expression in B. napus was identical to that of Arabidopsis during early development; however, the AG cis elements did not express at all during early flower development in L. usitatissimum. These results suggest that although regulatory factors controlling the generalized local expression of AG have been conserved between these species, those controlling temporal and tissue-specific expression have not.Key words: AGAMOUS, cis elements, regulation, Arabidopsis, Brassica napus, Linum usitatissimum.