bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical Features of Reflux Esophagitis in Older People: A Study of 840 Consecutive Patients
Authors: Pilotto Alberto , Franceschi Marilisa , Leandro Gioacchino , Scarcelli Carlo , D'Ambrosio Luigi P. , Seripa Davide , Perri Francesco , Niro Valeria , Paris Francesco , Andriulli Angelo , Di Mario Francesco
Published: September 2006

OBJECTIVES: To compare symptoms and other clinical characteristics of reflux esophagitis in patients of different ages.

DESIGN: Observational cross‐sectional study of consecutive patients.

SETTING: Geriatric Unit, Casa Sollievo della Sofferenza Hospital, Istituto di Ricovero e Cura a Carattere Scientifico.

PARTICIPANTS: Eight hundred forty patients with endoscopically diagnosed erosive esophagitis divided into four groups according to age (young (<50, mean 36.7, n=114), adult (50–69, mean 59.1, n=126), elderly (70–84, mean 77.3, n=425), and very elderly (≥85, mean 88.4, n=175)).

MEASUREMENTS: Gastrointestinal symptoms were evaluated using the Gastrointestinal Symptom Rating Scale questionnaire. Other symptoms were recorded when present as an indication for endoscopy. Severity of esophagitis, presence of Helicobacter pylori infection, presence and size of hiatus hernia, Barrett's esophagus, antrum or corpus gastric atrophy, and nonsteroidal antiinflammatory drug (NSAID) use were also evaluated.

RESULTS: Elderly and very elderly patients had a significantly lower prevalence of typical gastroesophageal reflux disease symptoms (heartburn or acid regurgitation (P<.001) and epigastric pain (P<.001)) than young and adult patients. Conversely, the prevalence of other symptoms (anorexia (P<.001), weight loss (P<.007), anemia (P<.001), vomiting (P<.001), and dysphagia (P<.001)) significantly increased with age. The prevalence of severe esophagitis (P<.001), hiatus hernia (P<.005), the size of hiatus hernia (P<.001), antrum and corpus gastric atrophy (P<.05) and NSAID use (P<.005) also significantly increased with age. Multivariate analysis demonstrated that older age (65–84, odds ratio (OR)=2.66, 95% confidence interval (CI)=1.38–5.12; ≥85, OR=4.57, 95% CI=2.15–9.71), hiatus hernia larger than 3 cm in diameter (OR=2.38, 95% CI=1.41–4.01), and male sex (OR=2.83, 95% CI=1.72–4.64) are independent risk factors for severe esophagitis, whereas H. pylori infection, gastric atrophy, NSAID use, and the presence of hiatus hernia were not.

CONCLUSION: Elderly patients with reflux esophagitis had less‐typical and more‐nonspecific symptoms than young or adult patients. Old age, male sex, and hiatus hernia size greater than 3 cm are significantly associated with severe esophagitis. Clinicians caring for older patients should be aware of the nonspecific presentation and potential severity of reflux esophagitis in this population.
Satisfaction with End‐of‐Life Care for Nursing Home Residents with Advanced Dementia
Authors: Engel Sharon E. , Kiely Dan K. , Mitchell Susan L.
Published: September 2006

OBJECTIVES: To identify factors associated with satisfaction with care for healthcare proxies (HCPs) of nursing home (NH) residents with advanced dementia.

DESIGN: Cross‐sectional study.

SETTING: Thirteen NHs in Boston.

PARTICIPANTS: One hundred forty‐eight NH residents aged 65 and older with advanced dementia and their formally designated HCPs.

MASUREMENTS: The dependent variable was HCPs' score on the Satisfaction With Care at the End of Life in Dementia (SWC‐EOLD) scale (range 10–40; higher scores indicate greater satisfaction). Resident characteristics analyzed as independent variables were demographic information, functional and cognitive status, comfort, tube feeding, and advance care planning. HCP characteristics were demographic information, health status, mood, advance care planning, and communication. Multivariate stepwise linear regression was used to identify factors independently associated with higher SWC‐EOLD score.

RESULTS: The mean ages±standard deviation of the 148 residents and HCPs were 85.0±8.1 and 59.1±11.7, respectively. The mean SWC‐EOLD score was 31.0±4.2. After multivariate adjustment, variables independently associated with greater satisfaction were more than 15 minutes discussing advance directives with a care provider at the time of NH admission (parameter estimate=2.39, 95% confidence interval (CI)=1.16–3.61, P<.001), greater resident comfort (parameter estimate=0.10, 95% CI=0.02–0.17, P=.01), care in a specialized dementia unit (parameter estimate=1.48, 95% CI=0.25–2.71, P=.02), and no feeding tube (parameter estimate=2.87, 95% CI=0.46–5.25, P=.02).

CONCLUSION: Better communication, greater resident comfort, no tube feeding, and care in a specialized dementia unit are modifiable factors that may improve satisfaction with care in advanced dementia.
Cariogenic Bacteria and Caries Risk in Elderly Japanese Aged 80 and Older with at Least 20 Teeth
Authors: Rodis Omar M. M. , Shimono Tsutomu , Matsumura Seishi , Hatomoto Kiyomi , Matsuo Keiko , Kariya Naoyuki , Okazaki Yoshihide , Ji Ying
Published: September 2006

OBJECTIVES: To assess caries risk and check the presence of four commonly found oral cariogenic bacteria in “8020” achievers.

DESIGN: Initial report based on Japan's newly implemented “8020” campaign, which aims to promote health and awareness in older people. Simply stated, the goal is, at 80 years, to maintain 20 teeth.

SETTING: Healthy community‐dwelling elderly individuals of Okayama Prefecture, Japan.

PARTICIPANTS: One hundred sixty individuals aged 80 and older with 20 of their own natural teeth.

MEASUREMENTS: General and oral health conditions, caries risk assessment using the Cariostat method, and polymerase chain reaction (PCR) detection of four oral cariogenic bacteria.

RESULTS: The participants had an average of 24.7 teeth, of which 12.1 were sound, 12.2 were treated, and 0.4 were untreated. Based on Cariostat scores, 64.4% had low caries risk. Using PCR, Streptococcus mutans, S. sobrinus, Lactobacillus casei, and L. plantarum were detected in 51.3%, 23.1%, 40%, and 25% of the participants, respectively. S. mutans (P<.001), S. sobrinus (P=.002), L. casei (P<.001), and L. plantarum (P=.001) deoxyribonucleic acid band was detected more in participants with high caries risk scores.

CONCLUSION: Participants with low caries risk scores had low prevalence of cariogenic bacteria, 20 or more sound teeth, and fewer missing teeth. Incorporating caries risk assessment, using the Cariostat and PCR analysis, in the “8020” campaign in health systems worldwide will contribute to a better life for the aging society, initiate research interest regarding the program, and improve current health policies.
An Evolutionary Algorithm for Site Search Problems
Authors: Xiao Ningchuan
Published: September 2006

The goal of solving a site search problem is to allocate a contiguous set of land parcels such that the total land acquisition cost, or other objectives, are optimized. This article describes the design and implementation of an evolutionary algorithm (EA) that can be used to solve site search problems. In this article, a graph representation is used to define the spatial structure of solutions to the problem. By using this representation, the contiguity of a site is maintained during the initialization, mutation, and local search operations of the EA. The effectiveness of the EA in finding optimal or near‐optimal solutions is demonstrated by testing it on a series of problems whose optimal solutions are known.
A Family of Location Models for Multiple‐Type Discrete Dispersion
Authors: Curtin Kevin M. , Church Richard L.
Published: September 2006

One of the defining objectives in location science is to maximize dispersion. Facilities can be dispersed for a wide variety of purposes, including attempts to optimize competitive market advantage, disperse negative impacts, and optimize security. With one exception, all of the extant dispersion models consider only one type of facility, and ignore problems where multiple types of facilities must be located. We provide examples where multiple‐type dispersion is appropriate and based on this develop a general class of facility location problems that optimize multiple‐type dispersion. This family of models expands on the previously formulated definitions of dispersion for single types of facilities, by allowing the interactions among different types of facilities to determine the extent to which they will be spatially dispersed. We provide a set of integer‐linear programming formulations for the principal models of this class and suggest a methodology for intelligent constraint elimination. We also present results of solving a range of multiple‐type dispersion problems optimally and demonstrate that only the smallest versions of such problems can be solved in a reasonable amount of computer time using general‐purpose optimization software. We conclude that the family of multiple‐type dispersion models provides a more comprehensive, flexible, and realistic framework for locating facilities where weighted distances should be maximized, when compared with the special case of locating only a single type of facility.
Topography of diabetic macular oedema compared with fluorescein angiography
Authors: Neubauer Aljoscha S. , Chryssafis Christos , Priglinger Siegfried G. , Haritoglou Christos , Thiel Martin , Welge‐Lüßen Ulrich , Kampik Anselm , Ulbig Michael W.
Published: September 2006

Purpose:  To compare the amount and pattern of fluorescein leakage in diabetic macular oedema with the retinal thickness maps obtained with the retinal thickness analyser (RTA) and optical coherence tomography (OCT).

Methods:  A consecutive series of 30 eyes from 30 patients with diabetic macular oedema was included. On fluorescein angiography (FA) the macula was analysed in 10 subfields as defined by the ETDRS. The amount and source of leakage for each field were determined. Retinal thickness was measured by OCT and RTA maps in each of the 10 fields and compared with the FA grading.

Results:  Foveal retinal thickness on OCT was most influenced by the overall FA leakage, which was the only significant covariate on multivariate analysis. The source and amount of leakage correlated significantly with the topography of retinal thickness in the four peripheral fields between 1500 µm and 3000 µm from the macular centre (r = 0.54, p = 0.002). The mean amount and source of leakage in those fields also showed the highest correlation with central macular thickness on OCT (r = 0.46, p = 0.01). Similar results were obtained by RTA when excluding ischaemic cases (r = 0.44, p = 0.04). For both instruments, FA leakage within the four central fields < 1500 µm did not correlate significantly with retinal thickness. Thickness by OCT and RTA were highly correlated with one another for central macular measurements (r = 0.73, p < 0.001), but correlated poorly in the peripheral fields. Overall, OCT measurements correlated more highly with FA.

Conclusions:  Optical coherence tomography and RTA thickness measurements can be used to identify patients for further examination. Fluorescein angiography leakage in the outer ETDRS fields correlates best with central thickness and retinal thickness topography by OCT.
Comparative study of neurological soft signs in schizophrenia with onset in childhood, adolescence and adulthood
Authors: Biswas P. , Malhotra S. , Malhotra A. , Gupta N.
Published: September 2006

Objective:  To compare neurological soft signs (NSS) in patients of schizophrenia with onset in childhood (COS), adolescence (AdOS) and adulthood (AOS).

Method:  Assessment of NSS in 15 patients of COS and 20 patients each of AdOS and AOS was made using condensed neuropsychiatric examination for NSS.

Results:  NSS were significantly more frequent in COS (100%) and AdOS (90%) when compared with AOS (55%) patients. COS patients showed significantly higher scores on temporal and frontal lobe NSS, of which differences between the three groups in temporal lobe NSS disappeared on ancova. Parietal lobe dependent NSS were seen in a few COS patients. The NSS were more in those with lesser IQ, lower education and higher Positive and Negative Syndrome Scale scores.

Conclusion:  Findings indicate that earlier onset types may be more strongly associated with a generalized disruption of brain function. Non‐suppression of primitive reflexes with cortical maturation in COS point towards disordered neurodevelopment. Preponderance of fronto‐temporal and a relative lack of parietal lobe NSS point towards differential lobar involvement. Neurodevelopmental abnormalities leading to NSS also lead to lower IQ and lower educational level.
Victorian Era Esthetic and Restorative Dentistry: An Advertising Trade Card Gallery
Authors: Croll Theodore P. , Swanson Ben Z.
Published: September 2006

A chief means of print advertising in the Victorian era was the “trade card.” Innumerable products, companies, and services were highlighted on colorful chromolithographic trade cards, and these became desirable collectible objects which were pasted into scrapbooks and enjoyed by many families. Dentistry‐ and oral health‐related subjects were often depicted on Victorian trade cards, and esthetic and restorative dentistry themes were featured. This review describes the history of advertising trade cards and offers a photographic gallery of dentistry‐related cards of the era.
Defoe as a Biographical Subject
Authors: Novak Max
Published: September 2006

This essay on writing a biography of Daniel Defoe is focused on two problems. How is biography possible in a time when many thinkers have argued that all history and biography are essentially forms of fiction and that the notion of a unified personality is an illusion? And how does one deal with the contention of John Richetti and others that a biography of Daniel Defoe has to be different from other biographies in that his character is essentially irretrievable from the past? The arguments of various critics on authorship have shown us that works of history and biography are never scientific presentations but rather works shaped by their authors. But it is only through such limited viewpoints that facts of a life or a history can have meaning. Defoe was a spy who took many identities, but placed in a determinable historical context, his opinions and motives are fairly consistent. As the many biographers of Defoe before me and I have shown, shaping the life and character of such a protean figure is challenging but is not as difficult as might be thought.
Twentieth‐ and Twenty‐first‐century Keats Criticism
Authors: Sandy Mark
Published: September 2006

This essay offers a survey of major twentieth‐ and twenty‐first‐century interpretations of Keats's life and work. Mapping lines of influence between distinctive formal, theoretical and historical approaches to Keats's oeuvre, I highlight significant critical trends and areas of recurrent formal and thematic interest in Keats studies. When appropriate, current confluences between these theoretical and historical methodologies are noted. Given the wide scope of material available, prominence has been given to those projects (where possible, emphasis is given to critical books) which both represent particular twentieth‐century critical perspectives or thematic concerns and are important studies in themselves. This survey closes by indicating potential areas for future research and observes that many twentieth‐century critical viewpoints and issues remain vital to Keats studies at the start of the twenty‐first century.
Quantitative analysis of the experimental O–J–I–P chlorophyll fluorescence induction kinetics
Authors: Boisvert Steve , Joly David , Carpentier Robert
Published: September 2006

Fluorescence induction has been studied for a long time, but there are still questions concerning what the O–J–I–P kinetic steps represent. Most studies agree that the O–J rise is related to photosystem II primary acceptor (QA) reduction, but several contradictory theories exist for the J–I and I–P rises. One problem with fluorescence induction analysis is that most work done to date has used only qualitative or semiquantitative data analysis by visually comparing traces to observe the effects of different chemicals or treatments. Although this method is useful to observe major changes, a quantitative method must be used to detect more subtle, yet important, differences in the fluorescence induction trace. To achieve this, we used a relatively simple mathematical approach to extract the amplitudes and half‐times of the three major fluorescence induction phases obtained from traces measured in thylakoid membranes kept at various temperatures. Apparent activation energies (EA) were also obtained for each kinetic step. Our results show that each phase has a different EA, with EA O–J <EA J–I < EA I‐P, and thus a different origin. The effects of two well‐known chemicals, 3‐(3,4‐dichlorophenyl)‐1,1‐dimethylurea, which blocks electron transfer to the photosystem II secondary electron acceptor (QB), and decylplastoquinone, which acts similarly to endogenous reducible plastoquinones, on the quantitative parameters are discussed in terms of the origin of each kinetic phase.
EFFECT OF HIGH HYDROSTATIC PRESSURE PROCESSING ON RHEOLOGICAL AND TEXTURAL PROPERTIES OF PROBIOTIC LOW‐FAT YOGURT FERMENTED BY DIFFERENT STARTER CULTURES
Authors: PENNA A.L.B. , GURRAM SUBBARAO , BARBOSA‐CÁNOVAS G.V.
Published: September 2006

The effect of milk processing on rheological and textural properties of probiotic low‐fat yogurt (fermented by two different starter cultures) was studied. Skim milk fortified with skim milk powder was subjected to three treatments: (1) thermal treatment at 85C for 30 min; (2) high hydrostatic pressure (HHP) at 676 MPa for 5 min; and (3) combined treatments of HHP (676 MPa for 5 min) and heat (85C for 30 min). The processed milk was fermented using two different starter cultures containing Streptococcus thermophilus, Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus acidophilus and Bifidobacterium longum at inoculation rates of 0.1 and 0.2%. Rheological parameters were determined and a texture profile analysis was carried out. Yogurts presented different rheological behaviors according to the treatment used, which could be attributed to structural phenomena. The combined HHP and heat treatment of milks resulted in yogurt gels with higher consistency index values than gels obtained from thermally treated milk. The type of starter culture and inoculation rate, providing different fermentation pathways, also affected the consistency index and textural properties significantly. The combined HHP and heat treatment of milks before fermentation, and an inoculation rate of 0.1% (for both cultures), led to desirable rheological and textural properties in yogurt, which presented a creamy and thick consistency that does not require the addition of stabilizers.
THERMAL DEGRADATION KINETICS OF SUCROSE, GLUCOSE AND FRUCTOSE IN SUGARCANE MUST FOR BIOETHANOL PRODUCTION
Authors: NOLASCO J. , DE MASSAGUER P.R.
Published: September 2006

Thermal degradation of sugars contained in sugarcane must (21.5°Brix, pH 6.14) was evaluated at temperatures of 110, 120, 130 and 140C, using the thermal‐death‐time tube method, determining remaining sugars by high‐pressure liquid chromatography. The study analyzed thermal degradation kinetics of both the total reducing sugars (TRS) and glucose and fructose individually.

All curves of remaining sugars presented strong nonlinearity, with initial shoulder and final tail adjusted by an extended logistic model that was adapted for two species for TRS, and a simple logistic model for the monosaccharides.

It was shown that rate constants are influenced by temperature according to two irreconcilable methods: the Arrhenius and the Bigelow methods. Obtained activation energies for fructose and glucose were quite coincident, 140.37 and 140.23 kJ/mol, respectively. Thermal resistance parameters were 21.59 and 21.61C, respectively. Comparison of the rate constants revealed that fructose degraded approximately 9–10 times faster than glucose.
Organ- and Disease-Stage-Specific Regulation ofToxoplasma gondii-Specific CD8-T-Cell Responses by CD4 T Cells
Authors: Lütjen Sonja , Soltek Sabine , Virna Simona , Deckert Martina , Schlüter Dirk
Published: September 2006

Toxoplasma gondiiinduces a persistent central nervous system infection, which may be lethally reactivated in AIDS patients with low CD4 T-cell numbers. To analyze the role of CD4 T cells for the regulation of parasite-specific CD8 T cells, mice were infected with transgenicT. gondiiexpressing the CD8 T-cell antigen β-galactosidase (β-Gal). Depletion of CD4 T cells prior to infection did not affect frequencies of β-Gal876-884-specific (consisting of residues 876 to 884 of β-Gal) CD8 T cells but resulted in a pronounced reduction of intracerebral β-Gal-specific gamma interferon (IFN-γ)-producing and cytolytic CD8 T cells. After cessation of anti-CD4 treatment a normalT. gondii-specific CD4 T-cell response developed, but IFN-γ production of intracerebral β-Gal-specific CD8 T cells remained impaired. The important supportive role of CD4 T cells for the optimal functional activity of intracerebral CD8 T cells was also observed in mice that had been depleted of CD4 T cells during chronic toxoplasmosis. Reinfection of chronically infected mice that had been depleted of CD4 T cells during either the acute or chronic stage of infection resulted in an enhanced proliferation of β-Gal-specific IFN-γ-producing splenic CD8 T cells. However, reinfection of chronically infected mice that had been depleted of CD4 T cells in the acute stage of infection did not reverse the impaired IFN-γ production of intracerebral CD8 T cells. Collectively, these findings illustrate that CD4 T cells are not required for the induction and maintenance of parasite-specific CD8 T cells but, depending on the stage of infection, the infected organ and parasite challenge infection regulate the functional activity of intracerebral CD8 T cells.
The C-Terminal Region of
Bacteroides fragilis
Toxin Is Essential to Its Biological Activity
Authors: Sears Cynthia L. , Buckwold Simy L. , Shin Jai W. , Franco Augusto A.
Published: September 2006

To evaluate the role of the C-terminal region in
Bacteroides fragilis
toxin (BFT) activity, processing, and secretion, sequential C-terminal truncation and point mutations were created by site-directed mutagenesis. Determination of BFT activity on HT29/C1 cells, cleavage of E-cadherin, and the capacity to induce interleukin-8 secretion by wild-type BFT and C-terminal deletion mutants showed that deletion of only 2 amino acid residues at the C terminus significantly reduced BFT biological activity and deletion of eight or more amino acid residues obliterated BFT biologic activity. Western blot and reverse transcription-PCR analyses indicated that BFT mutants lacking seven or fewer amino acid residues in the C-terminal region are processed and expressed similar to wild-type BFT. However, BFT mutants lacking eight or more amino acids at the C terminus are expressed similar to wild-type BFT but are unstable. We concluded that the C terminus of BFT is not tolerant of modest amino acid deletions, suggesting that it is biologically important for BFT activity.
Neutrophils Do Not Mediate the Pathophysiological Sequelae of
Cryptosporidium parvum
Infection in Neonatal Piglets
Authors: Zadrozny Leah M. , Stauffer Stephen H. , Armstrong Martha U. , Jones Samuel L. , Gookin Jody L.
Published: September 2006

Cryptosporidium parvum
is a minimally invasive protozoal pathogen of intestinal epithelium that results in villus atrophy, mucosal lipid peroxidation, diarrhea, and diminished barrier function. Influx of neutrophils is a consistent feature of human and animal cryptosporidiosis, and yet their contribution to the pathological sequelae of infection has not been investigated. Accordingly, we used an established neonatal piglet model of
C. parvum
infection to examine the role of neutrophils in disease pathogenesis by inhibiting their recruitment and activation in vivo using a monoclonal anti-CD18 antibody. Infected piglets were treated daily with anti-CD18 or isotype control immunoglobulin G and euthanized at peak infection, at which time neutrophil infiltrates, lipid peroxidation, severity of infection, and intestinal barrier function were quantified.
C. parvum
infection resulted in a significant increase in mucosal neutrophil myeloperoxidase activity that was prevented by treatment of piglets with anti-CD18 antibody. Neutrophil recruitment was dependent on mucosal superoxide formation (prevented by treatment of infected piglets with superoxide dismutase). Neutrophils did not contribute to peroxynitrite formation or peroxidative injury of
C. parvum
-infected mucosa and had no impact on the severity of epithelial infection, villus atrophy, or diarrhea. The presence of neutrophils in
C. parvum
-infected mucosa was associated with enhanced barrier function that could not be attributed to mucosal elaboration of prostaglandins or stimulation of their synthesis. These studies are the first to demonstrate that neutrophilic inflammation arising in response to infection by a noninvasive epithelial pathogen results in physiologic rather than pathological effects in vivo.
Identification of OmpU of
Vibrio vulnificus
as a Fibronectin-Binding Protein and Its Role in Bacterial Pathogenesis
Authors: Goo Sung Young , Lee Hyun-Ju , Kim Woo Hwang , Han Kyu-Lee , Park Dae-Kyun , Lee Hyun-Jung , Kim Sung Min , Kim Kun-Soo , Lee Kyu-Ho , Park Soon-Jung
Published: September 2006

Vibrio vulnificus
is a pathogenic bacterium that causes gastroenteritis and primary septicemia. To identify factors involved in microbial adherence to the host cells, we investigated bacterial proteins capable of binding to fibronectin, one of the main components comprised of the extracellular matrix of mammalian cells. A protein of ∼35 kDa was purified from the extracts of
V. vulnificus
by its property to bind to immobilized fibronectin. This protein was identified as OmpU, one of the major outer membrane proteins of
V. vulnificus
. In binding assays using immobilized fibronectin, the number of
ompU
mutant cells bound to fibronectin was only 4% of that of wild-type cells bound to fibronectin. In addition, the exogenous addition of antibodies against OmpU resulted in a decreased ability of wild-type
V. vulnificus
to adhere to fibronectin. The
ompU
mutant was also defective in its adherence to RGD tripeptide (5% of the adherence of the wild type to RGD), cytoadherence to HEp-2 cells (7% of the adherence of the wild type to HEp-2), cytotoxicity to cell cultures (39% of the cytotoxicity of the wild type), and mortality in mice (10-fold increase in the 50% lethal dose). The
ompU
mutant complemented with the intact
ompU
gene restored its abilities for adherence to fibronectin, RGD tripeptide, and HEp-2 cells; cytotoxicity to HEp-2 cells; and mouse lethality. This study indicates that OmpU is an important virulence factor involved in the adherence of
V. vulnificus
to the host cells.
Infection withSyphacia obvelata(Pinworm) Induces Protective Th2 Immune Responses and Influences Ovalbumin-Induced Allergic Reactions
Authors: Michels Chesney , Goyal Prem , Nieuwenhuizen Natalie , Brombacher Frank
Published: September 2006

Infections with pinworms are common in rodent animal facilities. In this study, we show the consequence of an outbreak in a transgenic barrier facility of infection bySyphacia obvelata, a murine pinworm gastrointestinal nematode. Immune responses were defined in experimental infection studies with BALB/c mice. Infection withS. obvelatainduced a transient Th2-type immune response with elevated interleukin 4 (IL-4), IL-5, and IL-13 cytokine production and parasite-specific immunoglobulin G1 (IgG1). In contrast, BALB/c mice deficient in IL-13, IL-4/13, or the IL-4 receptor alpha chain showed chronic disease, with a >100-fold higher parasite burden, increased gamma interferon production, parasite-specific IgG2b, and a default Th2 response. Interestingly, infected IL-4−/−BALB/c mice showed only slightly elevated parasite burdens compared to the control mice, suggesting that IL-13 plays the dominant role in the control ofS. obvelata. The influence that pinworm infection has on the allergic response to a dietary antigen was found to be important. Helminth-infected mice immunized against ovalbumin (Ova) elicited more severe anaphylactic shock with reduced Ova-specific IL-4 and IL-5 than did noninfected controls, demonstrating thatS. obvelatainfection is able to influence nonrelated laboratory experiments. The latter outcome highlights the importance of maintaining mice for use as experimental models under pinworm-free conditions.
High-Affinity Interaction between Fibronectin and the Group B Streptococcal C5a Peptidase Is Unaffected by a Naturally Occurring Four-Amino-Acid Deletion That Eliminates Peptidase Activity
Authors: Tamura Glen S. , Hull James R. , Oberg Michael D. , Castner David G.
Published: September 2006

The streptococcal C5a peptidase (ScpB) of group B streptococci (GBS) is found in virtually all clinical GBS isolates and is required for mucosal colonization in a neonatal mouse model. ScpB inhibits neutrophil chemotaxis by enzymatically cleaving the complement component C5a. We previously identified a second function of ScpB as a fibronectin (Fn) adhesin using phage display. However, phage display can identify low-affinity interactions. We therefore measured the affinity of both full-length recombinant ScpB (FL-ScpB) and the 110-amino-acid phage display fragment (Scp-PDF) for immobilized Fn using surface plasmon resonance. The affinity for Fn was very high for both FL-ScpB (equilibrium dissociation constant [

K
D

] = 4.0 nM) and Scp-PDF (

K
D

= 4.4 nM) and is consistent with a biologically significant role for the adhesin activity of ScpB. We also studied the Fn adhesin activity of a common natural variant of ScpB (ScpBΔ) that contains a 4-amino-acid deletion that eliminates peptidase activity. The integrity of
scpB
is otherwise maintained, suggesting that the Fn adhesin activity of ScpB may be responsible for its conservation in these strains. The affinities of both FL-ScpBΔ (

K
D

= 2.4 nM) and ScpBΔ-PDF (

K
D

= 1.4 nM) for Fn are unaffected by the deletion. Complementation in
trans
by both
scpB
and
scpB
Δ corrected the Fn-binding defect of an
scpB
deletion mutant GBS strain to an identical degree. The high affinity of ScpB for Fn and the maintenance of this affinity in ScpBΔ support our hypothesis that the Fn adhesin activity of
scpB
plays a role in virulence.
Chlamydia trachomatis
Infection Induces Cleavage of the Mitotic Cyclin B1
Authors: Balsara Zarine R. , Misaghi Shahram , Lafave James N. , Starnbach Michael N.
Published: September 2006

The obligate intracellular pathogen
Chlamydia trachomatis
interferes with a number of host cell processes, including cytoskeletal organization, vesicular trafficking, and apoptosis. In this study we report that
C. trachomatis
-infected cells proliferate more slowly than uninfected cells, suggesting that
C. trachomatis
may also manipulate the eukaryotic cell cycle. We further demonstrate that
C. trachomatis
infection destabilizes specific cell cycle proteins involved in the G
2
/M transition.
C. trachomatis
-infected cells, compared to uninfected cells, have lower levels of cyclin-dependent kinase 1. Additionally,
C. trachomatis
infection induces an N-terminal truncation of the mitotic cyclin B1. Manipulation of the host cell cycle may represent a strategy used by
C. trachomatis
to ensure a stable environment conducive to bacterial growth and replication.
Rapid Development of a Gamma Interferon-Secreting Glycolipid/CD1d-Specific Vα14+NK1.1−T-Cell Subset after Bacterial Infection
Authors: Emoto Masashi , Yoshizawa Izumi , Emoto Yoshiko , Miamoto Mamiko , Hurwitz Robert , Kaufmann Stefan H. E.
Published: September 2006

The phenotypic and functional changes of glycolipid presented by CD1d(glycolipid/CD1d) specific Vα14+T cells in the liver of mice at early stages of bacterial infection were investigated. AfterListeria monocytogenesinfection or interleukin-12 (IL-12) treatment, α-galactosylceramide/CD1d tetramer-reactive (α-GalCer/CD1d+) T cells coexpressing natural killer (NK) 1.1 marker became undetectable and, concomitantly, cells lacking NK1.1 emerged in both euthymic and thymectomized animals. Depletion of the NK1.1+subpopulation prevented the emergence of α-GalCer/CD1d+NK1.1−T cells. Before infection, NK1.1+, rather than NK1.1−, α-GalCer/CD1d+T cells coexpressing CD4 were responsible for IL-4 production, whereas gamma interferon (IFN-γ) was produced by cells regardless of NK1.1 or CD4 expression. After infection, IL-4-secreting cells became undetectable among α-GalCer/CD1d+T cells, but considerable numbers of IFN-γ-secreting cells were found among NK1.1−, but not NK1.1+, cells lacking CD4. Thus, NK1.1 surface expression and functional activities of Vα14+T cells underwent dramatic changes at early stages of listeriosis, and these alterations progressed in a thymus-independent manner. In mutant mice lacking all α-GalCer/CD1d+T cells listeriosis was ameliorated, suggesting that the subtle contribution of the NK1.1−T-cell subset to antibacterial protection is covered by more profound detrimental effects of the NK1.1+T-cell subset.
Anatomical Route of Invasion and Protective Mucosal Immunity inTrypanosoma cruziConjunctival Infection
Authors: Giddings O. K. , Eickhoff C. S. , Smith T. J. , Bryant L. A. , Hoft D. F.
Published: September 2006

Trypanosoma cruziis a protozoan parasite that can initiate mucosal infection after conjunctival exposure. The anatomical route ofT. cruziinvasion and spread after conjunctival parasite contamination remains poorly characterized. In the present work we have identified the sites of initial invasion and replication after contaminative conjunctival challenges withT. cruzimetacyclic trypomastigotes using a combination of immunohistochemical and real-time PCR confirmatory techniques in 56 mice between 3 and 14 days after challenge. Our results demonstrate that the predominant route of infection involves drainage of parasites through the nasolacrimal duct into the nasal cavity. Initial parasite invasion occurs within the ductal and respiratory epithelia. After successive waves of intracellular replication and cell-to-cell spread, parasites drain via local lymphatic channels to lymph nodes and then disseminate through the blood to distant tissues. This model of conjunctival challenge was used to identify immune responses associated with protection against mucosal infection. Preceding mucosal infection induces mucosal immunity, resulting in at least 50-fold reductions in recoverable tissue parasite DNA in immune mice compared to controls 10 days after conjunctival challenge (P< 0.05). Antigen-specific gamma interferon production by T cells was increased at least 100-fold in cells harvested from immune mice (P< 0.05). Mucosal secretions containingT. cruzi-specific secretory immunoglobulin A harvested from immune mice were shown to protect against mucosal parasite infection (P< 0.05), demonstrating that mucosal antibodies can play a role inT. cruziimmunity. This model provides an important tool for detailed studies of mucosal immunity necessary for the development of mucosal vaccines.
Comparison of Protective Efficacy of Subcutaneous versus Intranasal Immunization of Mice with aBrucella melitensisLipopolysaccharide Subunit Vaccine
Authors: Bhattacharjee Apurba K. , Izadjoo Mina J. , Zollinger Wendell D. , Nikolich Mikeljon P. , Hoover David L.
Published: September 2006

Groups of mice were immunized either subcutaneously or intranasally with purifiedBrucella melitensislipopolysaccharide (LPS) or with LPS as a noncovalent complex withNeisseria meningitidisgroup B outer membrane protein (LPS-GBOMP). Control mice were inoculated with sterile saline. Two doses of vaccine were given 4 weeks apart. Mice were challenged intranasally with virulentB. melitensisstrain 16M 4 weeks after the second dose of vaccine. Sera, spleens, lungs, and livers of mice were harvested 8 weeks after challenge. The bacterial loads in the organs were determined by culture on brucella agar plates. Protective efficacy was determined by comparing the clearance of bacteria from organs of immunized mice with the clearance of bacteria from organs of control mice. At 8 weeks postchallenge there was significant protection from disseminated infection of spleens and livers of mice intranasally immunized with either vaccine compared to infection of control mice (P< 0.01). There was no significant difference in clearance of bacteria from the lungs of immunized mice and control mice. However, mice immunized subcutaneously with either LPS or LPS-GBOMP vaccine showed significant protection against infection of the spleen (P< 0.001), liver (P< 0.001), and lungs (P< 0.05). These results show that intranasal immunization of mice with either vaccine provided significant protection against disseminated infection of the spleen and liver but subcutaneous immunization of mice with the vaccines conferred significant protection against infection of the spleen, liver, and lungs.
Transcutaneous Immunization with Toxin-Coregulated Pilin A Induces Protective Immunity against
Vibrio cholerae
O1 El Tor Challenge in Mice
Authors: Rollenhagen Julianne E. , Kalsy Anuj , Cerda Francisca , John Manohar , Harris Jason B. , LaRocque Regina C. , Qadri Firdausi , Calderwood Stephen B. , Taylor Ronald K. , Ryan Edward T.
Published: September 2006

Toxin-coregulated pilin A (TcpA) is the main structural subunit of a type IV bundle-forming pilus of
Vibrio cholerae
, the cause of cholera. Toxin-coregulated pilus is involved in formation of microcolonies of
V. cholerae
at the intestinal surface, and strains of
V. cholerae
deficient in TcpA are attenuated and unable to colonize intestinal surfaces. Anti-TcpA immunity is common in humans recovering from cholera in Bangladesh, and immunization against TcpA is protective in murine
V. cholerae
models. To evaluate whether transcutaneously applied TcpA is immunogenic, we transcutaneously immunized mice with 100 μg of TcpA or TcpA with an immunoadjuvant (cholera toxin [CT], 50 μg) on days 0, 19, and 40. Mice immunized with TcpA alone did not develop anti-TcpA responses. Mice that received transcutaneously applied TcpA and CT developed prominent anti-TcpA immunoglobulin G (IgG) serum responses but minimal anti-TcpA IgA. Transcutaneous immunization with CT induced prominent IgG and IgA anti-CT serum responses. In an infant mouse model, offspring born to dams transcutaneously immunized either with TcpA and CT or with CT alone were challenged with 10
6
CFU (one 50% lethal dose) wild-type
V. cholerae
O1 El Tor strain N16961. At 48 h, mice born to females transcutaneously immunized with CT alone had 36% ± 10% (mean ± standard error of the mean) survival, while mice born to females transcutaneously immunized with TcpA and CT had 69% ± 6% survival (
P
< 0.001). Our results suggest that transcutaneous immunization with TcpA and an immunoadjuvant induces protective anti-TcpA immune responses. Anti-TcpA responses may contribute to an optimal cholera vaccine.
Extensive Genotypic Diversity in a Recombining Population of the Apicomplexan ParasiteTheileria parva
Authors: Katzer Frank , Ngugi Daniel , Oura Chris , Bishop Richard P. , Taracha Evans L. N. , Walker Alan R. , McKeever Declan J.
Published: September 2006

We evaluated sexual recombination in the apicomplexan parasiteTheileria parvausing genome-wide marker analysis of haploid sporozoite populations obtained from infectedRhipicephalus appendiculatusticks. Analysis of 231 parasite clones derived by in vitro infection of bovine lymphocytes revealed 48 distinct combinations of 64 polymorphic marker loci. One genotype accounted for more than 75% of the clones, and the population was highly inbred with respect to this. The occurrence of frequent recombination was evident from reassortment of contiguous markers in blocks, with some recombination occurring within blocks. Analysis of four polymorphic loci encoding antigens targeted by protective cytotoxic-T-lymphocyte responses confirmed that these loci reassort, both within and between chromosomes, suggesting that recombination may influence immune recognition. Marker analysis of a panel of 142 clones derived from the population after an additional passage through a calf and the same tick colony revealed 18 genotypes, with the original dominant genotype accounting for 75% of the population and a higher level of inbreeding with respect to it in the remaining clones. Selected marker analysis of genomic DNA from these stabilates and the two preceding generations of the isolate, each derived from distinct tick colonies, revealed shifts in population structure with each generation, suggesting that the tick vector may impose nonrandom selective pressure on the parasite.
Immunogenicity of Duffy Binding-Like Domains That Bind Chondroitin Sulfate A and Protection against Pregnancy-Associated Malaria
Authors: Bir Nivedita , Yazdani Syed Shams , Avril Marion , Layez Corinne , Gysin Jürg , Chitnis Chetan E.
Published: September 2006

Sequestration of
Plasmodium falciparum-
infected erythrocytes in the placenta is implicated in pathological outcomes of pregnancy-associated malaria (PAM).
P. falciparum
isolates that sequester in the placenta primarily bind chondroitin sulfate A (CSA). Following exposure to malaria during pregnancy, women in areas of endemicity develop immunity, and so multigravid women are less susceptible to PAM than primigravidae. Protective immunity to PAM is associated with the development of antibodies that recognize diverse CSA-binding, placental
P. falciparum
isolates. The epitopes recognized by such protective antibodies have not been identified but are likely to lie in conserved Duffy binding-like (DBL) domains, encoded by
var
genes, that bind CSA. Immunization of mice with the CSA-binding DBL3γ domain encoded by
var1CSA
elicits cross-reactive antibodies that recognize diverse CSA-binding
P. falciparum
isolates and block their binding to placental cryosections under flow. However, CSA-binding isolates primarily express
var2CSA
, which does not encode any DBLγ domains. Here, we demonstrate that antibodies raised against DBL3γ encoded by
var1CSA
cross-react with one of the CSA-binding domains, DBL3X, encoded by
var2CSA
. This explains the paradoxical observation made here and earlier that anti-rDBL3γ sera recognize CSA-binding isolates and provides evidence for the presence of conserved, cross-reactive epitopes in diverse CSA-binding DBL domains. Such cross-reactive epitopes within CSA-binding DBL domains can form the basis for a vaccine that provides protection against PAM.
Immunization with Polyamine Transport Protein PotD Protects Mice against Systemic Infection with
Streptococcus pneumoniae
Authors: Shah P. , Swiatlo E.
Published: September 2006

The human pathogen
Streptococcus pneumoniae
contains genes for a putative polyamine ABC transporter which are organized in an operon and designated
potABCD
. Polyamine transport protein D (PotD) is an extracellular protein which binds polyamines and possibly other structurally related molecules. PotD has been shown to contribute to virulence in both a murine sepsis model and a pneumonia model with capsular type 3 pneumococci. The protective efficacy of recombinant PotD was evaluated by active immunization and intravenous challenge with capsular type 3 pneumococci in CBA/N mice. Immunized mice had 91.7% survival following lethal pneumococcal challenge, compared with 100% mortality in the control group. Immunized animals had high-titer anti-PotD antibodies following three immunizations with alum. Protection in a sepsis model was also seen after passive administration of rabbit antiserum raised against PotD (
P
< 0.004). These results suggest that antibodies to PotD confer protection against invasive pneumococcal disease and that this protein should be studied further as a potential vaccine candidate for protection against invasive pneumococcal infections.
Passive Immunization with a Multicomponent Vaccine against Conserved Domains of Apical Membrane Antigen 1 and 235-Kilodalton Rhoptry Proteins Protects Mice againstPlasmodium yoeliiBlood-Stage Challenge Infection
Authors: Narum David L. , Ogun Solabomi A. , Batchelor Adrian H. , Holder Anthony A.
Published: September 2006

During malaria parasite invasion of red blood cells, merozoite proteins bind receptors on the surface of the erythrocyte. Two candidatePlasmodium yoeliiadhesion proteins are apical membrane antigen 1 (AMA1) and the 235-kDa rhoptry proteins (P235). Previously, we have demonstrated that passive immunization with monoclonal antibodies (MAbs) 45B1 and 25.77 against AMA1 and P235, respectively, protects against a lethal challenge infection withP. yoeliiYM. We show that MAb 45B1 recognizes an epitope located on a conserved surface of PyAMA1, as determined by phage display and analysis of the three-dimensional structure of AMA1, in a region similar to that bound by theP. falciparumAMA1-specific inhibitory antibody 4G2. The epitope recognized by 25.77 could not be assigned. We report here that MAbs 45B1 and 25.77 also protect against challenge with the nonlethal parasite line 17X, in which PyAMA1 has a significantly different amino acid sequence from that in YM. When administered together, the two MAbs acted at least additively in providing protection against challenge with the virulent YM parasite. These results support the concept of developing a multicomponent blood-stage vaccine and the inclusion of polymorphic targets such as AMA1, which these results suggest contain conserved domains recognized by inhibitory antibodies.
OspF and OspC1 AreShigella flexneriType III Secretion System Effectors That Are Required for Postinvasion Aspects of Virulence
Authors: Zurawski Daniel V. , Mitsuhata Chieko , Mumy Karen L. , McCormick Beth A. , Maurelli Anthony T.
Published: September 2006

Shigella flexneriis the causative agent of dysentery, and its pathogenesis is mediated by a type III secretion system (T3SS).S. flexnerisecretes effector proteins into the eukaryotic cell via the T3SS, and these proteins usurp host cellular functions to the benefit of the bacteria. OspF and OspC1 are known to be secreted byS. flexneri, but their functions are unknown. We transformedS. flexneriwith a plasmid that expresses a two-hemagglutinin tag (2HA) in frame with OspF or OspC1 and verified that these proteins are secreted in a T3SS-dependent manner. Immunofluorescence of HeLa cells infected withS. flexneriexpressing OspF-2HA or OspC1-2HA revealed that both proteins localize in the nucleus and cytoplasm of host cells. To elucidate the function of these T3SS effectors, we constructed ΔospFand ΔospC1deletion mutants by allelic exchange. We found that ΔospFand ΔospC1mutants invade host cells and form plaques in confluent monolayers similar to wild-typeS. flexneri. However, in the polymorphonuclear (PMN) cell migration assay, a decrease in neutrophil migration was observed for both mutants in comparison to the migration of wild-type bacteria. Moreover, infection of polarized T84 intestinal cells infected with ΔospFand ΔospC1mutants resulted in decreased phosphorylation of extracellular signal-regulated kinase 1/2 in comparison to that of T84 cells infected with wild-typeS. flexneri. To date, these are the first examples of T3SS effectors implicated in mitogen-activated protein kinase kinase/extracellular signal-regulated kinase pathway activation. Ultimately, OspF and OspC1 are essential for PMN transepithelial migration, a phenotype associated with increased inflammation and bacterial access to the submucosa, which are fundamental aspects ofS. flexneripathogenesis.