bluuebunny/crossref_metadata_2025_split huggingface dataset:
Angiotensin II-induced inotropism requires an endocardial endothelium-nitric oxide mechanism in the in-vitro heart of Anguilla anguilla
Authors: Imbrogno Sandra , Cerra Maria Carmela , Tota Bruno 
Published: June 2003

SUMMARY
Using an isolated working heart preparation we show that angiotensin II(ANG II), at concentrations of 10-10–10-7 mol l-1, elicits negative chronotropism and inotropism in the freshwater eel Anguilla anguilla. The negative inotropism was insensitive to losartan and CGP42112 (AT1 and AT2 ANG II receptor antagonists, respectively), and was abrogated by the AT1receptor antagonist CV11974, the G protein blocker pertussis toxin (PTx) and the muscarinic antagonist atropine. In contrast, it was not affected by the adrenoceptor antagonists propanolol, sotalol and phentolamine. Using donors(l-arginine) and inhibitors[NG-monomethyl-L-arginine (l-NMMA), l-N5(1-iminoethyl)ornithine (L-NIO)] of nitric oxide synthase (NOS), and haemoglobin as NO scavenger, we demonstrate that NO signalling is involved in ANG II-mediated inotropism. Pretreatment with Triton X-100, a detergent that damages the endocardial endothelium (EE),or with 1H-(1,2,4)oxadiazolo-(4,3-a)quinoxalin-1-one (ODQ), a specific inhibitor of soluble guanylate cyclase, or with the cGMP-activated protein kinase (PKG) inhibitor KT5328, abolished ANG II-mediated inotropism. Thus, ANG II-mediated inotropism occurs via an EE-NO-cGMP-PKG mechanism. ANG II did not affect the mechanical performance influenced by preload changes (i.e. the Frank–Starling response), which in the eel heart is modulated by NO. This EE-paracrine-mediated cardio-suppressive action of endoluminal ANG II suggests that the hormone plays an important intracardiac role in the fish heart.
Conservation of feline semen: Part II: Cold-induced damages on spermatozoal fertilizing ability
Authors: Luvoni G.C , Kalchschmidt E , Marinoni G 
Published: June 2003

During the conservation of feline semen, the freeze–thaw procedure in particular is responsible for inducing severe spermatozoal damage, which diminishes fertilizing ability. Therefore, cold-induced damage represents a limiting factor for the conservation of semen, particularly semen from felids, which are often affected by teratospermia. In this article, feline sperm characteristics are reported, with special reference to motility and morphology, which are more likely to be affected by conservation protocols; and moreover, the causes of cold-induced damages are described. Attention has been focused on methods to evaluate functional integrity of spermatozoa, and those applied to cat semen are reviewed. Among these, a rather recently developed technique involves fluorescent staining methods, and in particular chlortetracycline. The chlortetracycline assay applied to cryopreserved cat epididymal sperm shows that it is suitable to evaluate the functional status of cat sperm.
Reduction in muscle fibre number during the adaptive radiation of notothenioid fishes: a phylogenetic perspective
Authors: Johnston Ian A. , Fernández Daniel A. , Calvo Jorge , Vieira Vera L. A. , North Anthony W. , Abercromby Marguerite , Garland Theodore 
Published: June 2003

SUMMARYThe fish fauna of the continental shelf of the Southern Ocean is dominated by a single sub-order of Perciformes, the Notothenioidei, which have unusually large diameter skeletal muscle fibres. We tested the hypothesis that in fast myotomal muscle a high maximum fibre diameter (FDmax) was related to a reduction in the number of muscle fibres present at the end of the recruitment phase of growth. We also hypothesized that the maximum fibre number (FNmax) would be negatively related to body size,and that both body size and size-corrected FNmax would show phylogenetic signal (tendency for related species to resemble each other). Finally, we estimated ancestral values for body size and FNmax. A molecular phylogeny was constructed using 12S mitochondrial rRNA sequences. A total of 16 species were studied from the Beagle Channel, Tierra del Fuego (5-11°C), Shag Rocks, South Georgia(0.5-4°C), and Adelaide Island, Antarctic Peninsula (-1.5 to 0.5°C). The absence of muscle fibres of less than 10 μm diameter was used as the criterion for the cessation of fibre recruitment. FDmaxincreased linearly with standard length (SL), reaching 500-650 μm in most species. Maximum body size was a highly significant predictor of species variation in FNmax, and both body size and size-corrected FNmax showed highly significant phylogenetic signal (P&lt;0.001). Estimates of trait values at nodes of the maximum likelihood phylogenetic tree were consistent with a progressive reduction in fibre number during part of the notothenioid radiation, perhaps serving to reduce basal energy requirements to compensate for the additional energetic costs of antifreeze production. For example, FNmax in Chaenocephalus aceratus (12 700±300, mean ± s.e.m., N=18) was only 7.7% of the value found in Eleginops maclovinus (164 000±4100, N=17), which reaches a similar maximum length (85 cm). Postembryonic muscle fibre recruitment in teleost fish normally involves stratified followed by mosaic hyperplasia. No evidence for this final phase of growth was found in two of the most derived families(Channichthyidae and Harpagiferidae). The divergence of the notothenioids in Antarctica after the formation of the Antarctic Polar Front and more recent dispersal north would explain the high maximum diameter and low fibre number in the derived sub-Antarctic notothenioids. These characteristics of notothenioids may well restrict their upper thermal tolerance, particularly for Champsocephalus esox and similar Channichthyids that lack respiratory pigments.
Functional Similarities between theicm/dotPathogenesis Systems ofCoxiella burnetiiandLegionella pneumophila
Authors: Zusman Tal , Yerushalmi Gal , Segal Gil 
Published: June 2003

ABSTRACTCoxiella burnetii, the etiological agent of Q fever, is an obligate intracellular pathogen, whereasLegionella pneumophila, the causative agent of Legionnaires' disease, is a facultative intracellular pathogen. During infection of humans both of these pathogens multiply in alveolar macrophages inside a closed phagosome.L. pneumophilaintracellular multiplication was shown to be dependent on theicm/dotsystem, which probably encodes a type IV-related translocation apparatus. Recently, genes homologous to all of theL. pneumophila icm/dotgenes (besidesicmR) were found inC. burnetii.To explore the similarities and differences between theicm/dotpathogenesis systems of these two pathogens, interspecies complementation analysis was performed. NineC. burnetii icmhomologous genes (icmT,icmS,icmQ,icmP,icmO,icmJ,icmB,icmW, andicmX) were cloned under regulation of the correspondingL. pneumophila icmgenes and examined for the ability to complementL. pneumophilamutants with mutations in these genes. TheC. burnetii icmSandicmWhomologous genes were found to complement the correspondingL. pneumophila icmmutants to wild-type levels of intracellular growth in both HL-60-derived human macrophages andAcanthamoeba castellanii. In addition, theC. burnetii icmThomologous gene was found to completely complement anL. pneumophilainsertion mutant for intracellular growth in HL-60-derived human macrophages, but it only partially complemented the same mutant for intracellular growth inA. castellanii. Moreover, as previously shown forL. pneumophila, the proteins encoded by theC. burnetii icmSandicmWhomologous genes were found to interact with one another, and interspecies protein interaction was observed as well. Our results strongly indicate that the Icm/Dot pathogenesis systems ofC. burnetiiandL. pneumophilahave common features.
Intestinal and Systemic Immune Responses to an Oral Cholera Toxoid B Subunit Whole-Cell Vaccine Administered during Zinc Supplementation
Authors: Karlsen Tom H. , Sommerfelt Halvor , Klomstad Skjalg , Andersen Per Kragh , Strand Tor A. , Ulvik Rune J. , Åhrén Christina , Grewal Harleen M. S. 
Published: June 2003

ABSTRACTZinc plays a critical role in the normal functioning of the immune system. We investigated whether zinc sulfate administered orally to adult zinc-replete volunteers modulates systemic and intestinal immune responses to an oral killed cholera toxoid B subunit (CTB) whole-cell cholera vaccine. The 30 participants were immunized twice, with a 17-day interval. The vaccinees in the intervention group ingested 45 mg of elemental zinc thrice daily for 9 days starting 2 days before each vaccine dose. The median serum anti-CTB immunoglobulin A (IgA) and IgG responses from day 0 to day 30, i.e. after two vaccine doses, were 13-fold lower(Pvalue for identical distribution, <0.005) in the zinc-supplemented compared to the nonsupplemented vaccinees. The median serum vibriocidal responses from baseline to after one (day 0 to day 17) and two (day 0 to day 30) vaccine doses were at least sixfold(P= 0.033) and fourfold(P= 0.091) higher, while the median fecal anti-CTB IgA response after two doses was estimated to be fourfold higher(P= 0.084) in the zinc-supplemented vaccinees. These observations show that zinc reduces the antitoxin and may enhance the antibacterial responses in serum. Zinc may also improve the intestinal antitoxin immune response. Oral zinc administration has the potential to modify critical immune responses to antigens applied to mucosal surfaces.
Identification of CD8 T-Lymphocyte Epitopes in OmpB ofRickettsia conorii
Authors: Li Zhen , Díaz-Montero C. Marcela , Valbuena Gustavo , Yu Xue-Jie , Olano Juan P. , Feng Hui-Min , Walker David H. 
Published: June 2003

ABSTRACTThe 1.2-kb DNA fragment of theRickettsia conoriiouter membrane protein B gene (OmpB451-846) was subcloned using site-specific PCR primers and expressed as six smaller fragments: OmpB458-652, OmpB595-744, OmpB595-654, OmpB645-692, OmpB689-744, and OmpB739-848. NCTC cells transfected with a mammalian expression vector expressing the fragments OmpB689-744and OmpB739-848stimulated immune anti-R.conoriiCD8 T lymphocytes, suggesting the presence of CD8 T-lymphocyte-stimulating epitopes on these fragments. In order to further characterize the CD8 T-lymphocyte-stimulatory elements, CD8 T-lymphocyte epitopes on OmpB689-744and OmpB739-848were mapped by overlapping synthetic peptides. The ability of these synthetic peptides to stimulate immune CD8 T lymphocytes was determined by gamma interferon (IFN-γ) production and cell proliferation after incubation with simian virus 40-transformed murine vascular endothelial cells in the presence of a 20 μM solution of each synthetic peptide. Five synthetic peptides, SKGVNVDTV (OmpB708-716), ANVGSFVFN (OmpB735-743), IVSGTVGGQ (OmpB749-757), ANSTLQIGG (OmpB789-797), and IVEFVNTGP (OmpB812-820), induced secretion of IFN-γ at significantly higher levels than the controls. Three of these five peptides, SKGVNVDTV (OmpB708-716), ANSTLQIGG (OmpB789-797), and IVEFVNTGP (OmpB812-820), also stimulated the proliferation of immune CD8 T lymphocytes. Significantly higher levels of specific cytotoxic T-lymphocyte killing were observed with the same three synthetic peptides, SKGVNVDTV (OmpB708-716), ANSTLQIGG (OmpB789-797), and IVEFVNTGP (OmpB812-820).
Borrelia burgdorferi-Induced Tolerance as a Model of Persistence via Immunosuppression
Authors: Diterich Isabel , Rauter Carolin , Kirschning Carsten J. , Hartung Thomas 
Published: June 2003

ABSTRACTIf left untreated, infection withBorrelia burgdorferisensu lato may lead to chronic Lyme borreliosis. It is still unknown how this pathogen manages to persist in the host in the presence of competent immune cells. It was recently reported thatBorreliasuppresses the host's immune response, thus perhaps preventing the elimination of the pathogen (I. Diterich, L. Härter, D. Hassler, A. Wendel, and T. Hartung, Infect. Immun. 69:687-694, 2001). Here, we further characterizeBorrelia-induced immunomodulation in order to develop a model of this anergy. We observed that the differentBorreliapreparations that we tested, i.e., live, heat-inactivated, and sonicatedBorrelia, could desensitize human blood monocytes, as shown by attenuated cytokine release upon restimulation with any of the different preparations. Next, we investigated whether theseBorrelia-specific stimuli render monocytes tolerant, i.e. hyporesponsive, towards another Toll-like receptor 2 (TLR2) agonist, such as lipoteichoic acid from gram-positive bacteria, or towards the TLR4 agonist lipopolysaccharide. Cross-tolerance towards all tested stimuli was induced. Furthermore, using primary bone marrow cells from TLR2-deficient mice and from mice with a nonfunctional TLR4 (strain C3H/HeJ), we demonstrated that the TLR2 was required for tolerance induction byBorrelia, and using neutralizing antibodies, we identified interleukin-10 as the key mediator involved. Although peripheral blood mononuclear cells tolerized byBorreliaexhibited reduced TLR2 and TLR4 mRNA levels, the expression of the respective proteins on monocytes was not decreased, ruling out the possibility that tolerance toBorreliais attributed to a reduced TLR2 expression. In summary, we characterized tolerance induced byB. burgdorferi, describing a model of desensitization which might mirror the immunosuppression recently attributed to the persistence ofBorreliain immunocompetent hosts.
ASalmonella entericaSerovar Typhimurium Translocated Leucine-Rich Repeat Effector Protein Inhibits NF-κB-Dependent Gene Expression
Authors: Haraga Andrea , Miller Samuel I. 
Published: June 2003

ABSTRACTNontyphoidal salmonellae are enteric pathogens that cause acute gastroenteritis and colonize the intestinal tract for prolonged periods. In the intestinal epithelia, these bacteria induce secretion of proinflammatory cytokines, such as interleukin-8 (IL-8), which leads to a profound inflammatory response through recruitment of polymorphonuclear leukocytes. Production of IL-8 induced bySalmonellaspp. is due to the activation of the transcription factors nuclear factor κB (NF-κB) and activator protein-1 (AP-1). This work demonstrates thatSalmonella entericaserovar Typhimurium can downmodulate IL-8 production after invasion of intestinal epithelial cells. TheSalmonellatranslocated effector proteins SspH1 and SptP participate in this process. SspH1 is a member of the bacterial LPX repeat protein family that localizes to the mammalian nucleus and inhibits NF-κB-dependent gene expression. AShigella flexneritranslocated effector, IpaH9.8, which has a similar structure and subcellular localization in mammalian cells, also inhibits NF-κB-dependent gene expression. We propose that suppression of inflammatory responses by intracellularS. entericaserovar Typhimurium, and perhapsShigella flexneri, contributes to bacterial colonization of host tissues and pathogenesis.
Helicobacter pyloriPreferentially Induces Interleukin 12 (IL-12) Rather than IL-6 or IL-10 in Human Dendritic Cells
Authors: Guiney Donald G. , Hasegawa Patty , Cole Sheri P. 
Published: June 2003

ABSTRACTDendritic cells are potent antigen-presenting cells that are present in the gastrointestinal tract and are required for the induction of a Th1 T-cell acquired immune response. Since infection with the gastric pathogenHelicobacter pylorielicits a Th1 cell response, the interaction of these organisms with dendritic cells should reflect the Th1 bias. We incubatedH. pyloriwith cultured human dendritic cells and measured the cytokine induction profile, comparing the response to that induced bySalmonella entericaserovar Typhimurium. We found thatH. pyloriinduced little interleukin 6 (IL-6) and essentially no IL-10 in contrast toS. enterica.However,H. pyloriinduced levels of IL-12 that were 30% of those induced byS. enterica,indicating a Th1 response. An isogeniccagEmutant ofH. pylorilost about 50% of its IL-12-inducing ability, suggesting a role for thecagtype IV secretion system in the stimulation of dendritic cells.
The pattern of motor coordination underlying the roll in the lamprey
Authors: Zelenin Pavel V. , Grillner Sten , Orlovsky Grigori N. , Deliagina Tatiana G. 
Published: June 2003

SUMMARYThe lamprey swims by caudally directed lateral undulations of its body. During swimming the animal is oriented with its dorsal side up, and any deviation from this posture (roll tilt) elicits a corrective motor response aimed at restoring the normal orientation. Video recording was used to study the kinematic pattern of the response to a 90° roll tilt imposed in the intact lamprey. The corrective responses were associated with specific modifications of the swimming movements. The plane of locomotor undulations deviated from the normal, i.e. frontal plane in one direction at the beginning of the rotation and in the opposite direction at its end. A similar motor pattern was also observed in the anterior part of the body of lampreys in which the spinal cord had been transected in the mid-body area, when performing postural corrections. It could also be observed during roll turns performed by lampreys after a rostral hemisection of the spinal cord. We argue that these modifications of the locomotor pattern generate the moments of force necessary for initiation and termination of the corrective roll turn. Possible neuronal mechanisms causing the corrective movements are discussed.
Hemoglobin function in deep-sea and hydrothermal-vent endemic fish:Symenchelis parasitica(Anguillidae) andThermarces cerberus(Zoarcidae)
Authors: Weber Roy E. , Hourdez Stephane , Knowles Francis , Lallier Francois 
Published: June 2003

SUMMARYDeep-sea hydrothermal vents probably provide the harshest physico-chemical conditions confronting metazoan animals in nature. Given the absence of information on hemoglobin (Hb) function in hydrothermal-vent vertebrates, and the complex molecular and functional adaptations observed in hydrothermal-vent invertebrates, we investigated the oxygenation reactions of Hbs from the vent-endemic zoarcid Thermarces cerberus and the deep-sea anguillid Symenchelis parasitica from adjacent habitats.Electrophoretically cathodic and anodic isoHbs from S. parasiticaexhibit radical differences in O2 affinity and pH and organic phosphate (ATP) sensitivities, reflecting a division of labor as in other`class II' fish that express both Hb types. Remarkably, the cathodic Hb (I)lacks chloride sensitivity, and the anodic Hb (II) shows anticooperativity near half-saturation at low temperature. T. cerberus isoHbs exhibit similar affinities and pH sensitivities (`class I' pattern) but much higher O2 affinities than those observed in Hbs of the temperate,shallow-water zoarcid Zoarces viviparus, which, unless compensated,reveals markedly higher blood O2 affinities in the former species. The temperature sensitivity of O2 binding to T. cerberusHbs and the anodic S. parasitica Hb, which have normal Bohr effects,is decreased by endothermic proton dissociation, which reduces the effects of ambient temperature variations on O2 affinity. In the cathodic S. parasitica Hb, similar reduction appears to be associated with endothermic conformational changes that accompany the oxygenation reaction.
Shock wave therapy induces neovascularization at the tendon–bone junction. A study in rabbits
Authors: Wang Ching‐Jen , Wang Feng‐Sheng , Yang Kuender D. , Weng Lin‐Hsiu , Hsu Chia‐Chen , Huang Chun‐Shun , Yang Lin‐Cheng 
Published: June 2003

AbstractDespite the success in clinical application, the exact mechanism of shock wave therapy remains unknown. We hypothesized that shock wave therapy induces the ingrowth of neovascularization and improves blood supply to the tissues. The purpose of this study was to investigate the effect of shock wave therapy on neovascularization at the tendon–bone junction. Fifty New Zealand white rabbits with body weight ranging from 2.5 to 3.5 kg were used in this study. The right limb (the study side) received shock wave therapy to the Achilles tendon near the insertion to bone. The left limb (the control side) received no shock wave therapy. Biopsies of the tendon–bone junction were performed in 0, 1, 4, 8 and 12 weeks. The number of neo‐vessels was examined microscopically with hematoxylin–eosin stain. Neovascularization was confirmed by the angiogenic markers including vessel endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS) expressions and endothelial cell proliferation determined by proliferating cell nuclear antigen (PCNA) expression examined microscopically with immunohistochemical stains. The results showed that shock wave therapy produced a significantly higher number of neo‐vessels and angiogenesis‐related markers including eNOS, VEGF and PCNA than the control without shock wave treatment. The eNOS and VEGF began to rise in as early as one week and remained high for 8 weeks, then declined at 12 weeks; whereas the increases of PCNA and neo‐vessels began at 4 weeks and persisted for 12 weeks. In conclusion, shock wave therapy induces the ingrowth of neovascularization associated with early release of angiogenesis‐related markers at the Achilles tendon–bone junction in rabbits. The neovascularization may play a role to improve blood supply and tissue regeneration at the tendon–bone junction. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Detection of a
luxS
-Signaling Molecule in
Bacillus anthracis
Authors: Jones Marcus B. , Blaser Martin J. 
Published: June 2003

ABSTRACT

Quorum-sensing regulation of density-dependent genes has been described for numerous bacterial species. The partially annotated genome sequence of
Bacillus anthracis
contains an open reading frame (BA5047) predicted to encode an ortholog of
luxS
, required for synthesis of the quorum-sensing signaling molecule autoinducer-2 (AI-2). To determine whether
B. anthracis
produces AI-2, the
Vibrio harveyi
luminescence bioassay was used. Cell-free conditioned media from vaccine (Sterne) strain 34F
2
induced luminescence in
V. harveyi
reporter strain BB170, indicating its production of AI-2. Cloned BA5047, expressed in
Escherichia coli
DH5α cells, restored AI-2 activity to these cells. To evaluate whether BA5047 is essential for AI-2 synthesis, it was deleted through allelic exchange with marker rescue; the resulting mutant had no functional
luxS
activity and had reduced growth in vitro. In the wild-type strain, AI-2 activity was greatest during the exponential phase of growth. In total, these data indicate that BA5047 is a functional
luxS
ortholog in
B. anthracis
necessary for growth-phase-specific AI-2 expression. Thus,
B. anthracis
may utilize extracellular signaling molecules to regulate density-dependent gene expression.