bluuebunny/crossref_metadata_2025_split huggingface dataset:
Accessibility of selected hospitals and medical procedures by means of aerial and transit network-based measures
Authors: Costa L. S. , Nassi C. D. , Pinheiro R. S. , Almeida R. M. V. R. 
Published: May 2003

Objective: This report investigates the use of linear and travelled route (transit network-based) distances in estimating the accessibility of hospitals to patients, for some selected hospital admission diagnostics. Methods: For patients admitted to 14 public hospitals in Rio de Janeiro City, during 1996, under the ICD-9 headings 'Complications of Pregnancy, Childbirth and the Puerperium' and 'Disorders of the Circulatory System', average distances between the patient's district of residence and hospital of admission were calculated (both as Euclidean and as network-based distances). Data were obtained from the country's public health data processing agency. Geographic co-ordinates were obtained for districts of residence from the postal codes of the patients' residences. Distances were estimated with the TransCAD Geographical Information System, based on a map of the city transit network. There were 8654 patients admitted under the 'Complications of Pregnancy' heading and 3439 under 'Disorders of Circulatory System'. Results: Variations of up to a factor of 5.3, and up to 34 km, could be identified between linear and network estimates. Conclusion: While recognizing that network estimates have advantages, the literature on accessibility frequently argues that aerial estimates are a good approximation for those. The present results show that this is not necessarily the case.
Detection of chimerism following vascularized bone allotransplantation by polymerase chain reaction using a Y‐chromosome specific primer
Authors: Muramatsu Keiichi , Valenzuela Richard G. , Bishop Allen T. 
Published: June 2003

AbstractChimerism following allogeneic organ transplantation is a phenomenon known to occur and be associated with development of immunologic tolerance in allotransplantation. However, little is known about graft cell migration following vascularized bone allografting. In this study, chimerism was assessed following vascularized tibia transplantation from male DA or PVG donors to female PVG rat recipients using a semi‐quantitative polymerase chain reaction for the Y‐chromosome. FK‐506 (Tacrolimus) was administered after transplantation for immunosuppression. All immunosuppresssed PVG rat recipients of PVG bone grafts showed a high level of chimerism (1%) in the thymus, spleen, liver and cervical lymph nodes at 18 weeks post‐transplant. Donor cells were also detected in the contralateral tibia and humerus. In non‐immunosuppressed PVG rat recipients of DA bone grafts, donor cells were detected in the spleen in three of five rats within 2 weeks post‐transplant. In these animals the bone grafts were severely rejected. In immunosuppressed PVG rat recipients of DA bone grafts, two of five, four of eight and eight of 10 rats showed low level chimerism (0.1%) in peripheral blood at 1, 12, and 18 weeks post‐transplant. Six rats showed a high level of chimerism in the spleen and thymus. Histological studies revealed no rejection findings through 18 weeks post‐transplant. Our results indicate that chimerism, or the presence of graft cells in host tissue, may occur in the face of acute rejection and be demonstrable following vascularized isograft and allograft living bone transplantation when chronic immunosuppression is maintained. Graft vascular patency during the short‐term likely allows cellular migration, even in the face of acute rejection. Long‐term survival and proliferation of graft marrow elements in host tissue may be possible with adequate immunosuppression. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Characterization of Transmission of
Pneumocystis carinii
f. sp.
muris
through Immunocompetent BALB/c Mice
Authors: Gigliotti F. , Harmsen A. G. , Wright T. W. 
Published: June 2003

ABSTRACT

By using mouse models, it has been shown that
Pneumocystis carinii
f. sp.
muris
can be transmitted to immunocompetent mice that are exposed to immunosuppressed mice with active
P. carinii
pneumonia. We sought to determine whether
P. carinii
f. sp.
muris
could be transmitted between normal mice. The rationale for these experiments was to demonstrate whether the normal host could serve as the reservoir of organisms that produce Pcp when the organism is acquired by the immunosuppressed host. Under the conditions of these experiments, normal mice are able to be infected by brief cohousing with
P. carinii
-infected SCID mice. There was active replication of organisms in the normal host such that the organism could be transmitted to other normal mice, again with active replication. Mice that had seroconverted after exposure to
P. carinii
-infected SCID mice were more resistant to infection when reexposed. Infection in normal mice was well tolerated with minimal effects on dynamic lung compliance. We speculate, based on these results, that transmission from normal host to normal host, as an asymptomatic or minimally symptomatic infection, could be a way to maintain this opportunistic pathogen in the environment.
Macrophage-Mediated Germination of
Bacillus anthracis
Endospores Requires the
gerH
Operon
Authors: Weiner Matthew A. , Hanna Philip C. 
Published: June 2003

ABSTRACT

The

gerH
abc

operon of
Bacillus anthracis
, encoding a
gerA
-like family member of germinant sensors, was shown to be required for endospore germination in the presence of macrophages and in macrophage-conditioned media. The loss of the germination phenotype in macrophage cultures of
B. anthracis gerH
-null endospores was restored by complementation in
trans
with a wild-type copy of
gerH
expressed under the control of its own promoter. Using endospores from both the parental strain
B. anthracis
Sterne and an isogenic
gerH
-null strain, we partially characterized germinants secreted by macrophages into the extracellular medium.
HEp-2 Cell Adherence, Actin Aggregation, and Intimin Types of Attaching and Effacing
Escherichia coli
Strains Isolated from Healthy Infants in Germany and Australia
Authors: Beutin Lothar , Marchés Olivier , Bettelheim Karl A. , Gleier Kerstin , Zimmermann Sonja , Schmidt Herbert , Oswald Eric 
Published: June 2003

ABSTRACT

Fecal samples from healthy children under 2 years of age living in Berlin, Germany (205 infants), and Melbourne, Australia (184 infants), were investigated for the presence of attaching and effacing (AE)
Escherichia coli
(AEEC) strains by screening for
eae
(intimin) genes. Twenty-seven AEEC strains were isolated from 14 children (7.6%) from Melbourne and from 12 children (5.9%) from Berlin. The 27 AEEC strains were classified as enterohemorrhagic
E. coli
(one strain, producing Shiga toxin 1), typical enteropathogenic
E. coli
(EPEC) (one strain carrying an EPEC adherence factor [EAF] plasmid), and atypical EPEC (25 strains negative for Shiga toxins and EAF plasmids). The AEEC were divided into 18 different serotypes, O-nontypeable and O-rough strains. Typing of their intimin genes revealed the presence of intimin α in 6 strains, intimin β in 11 strains, intimin γ in 7 strains, intimin ζ in 2 strains, and intimin η in one strain. Analysis of HEp-2 cell adherence showed diffuse adherence or localized adherence-like patterns in 26 AEEC strains; local adherence was found only with the EAF-positive strain. Ten AEEC strains showed an AE property with the fluorescent actin staining (FAS) test. The introduction of an EAF plasmid (pMAR7) converted 11 FAS-negative AEEC strains to FAS positive and increased the FAS reaction in six FAS-positive AEEC strains, indicating that the genes needed for the AE phenotype were functional in these strains. Our finding indicates that atypical EPEC strains could play a double role as strains that naturally immunize against intimin in humans and as reservoirs for new emerging human pathogenic EPEC strains.
Lack of Gender-Specific Antibody Recognition of Products from Domains of a
var
Gene Implicated in Pregnancy-Associated
Plasmodium falciparum
Malaria
Authors: Jensen Anja T. R. , Zornig Hanne D. , Buhmann Caecilie , Salanti Ali , Koram Kwadwo A. , Riley Eleanor M. , Theander Thor G. , Hviid Lars , Staalsoe Trine 
Published: June 2003

ABSTRACT

Gender-specific and parity-dependent acquired antibody recognition is characteristic of variant surface antigens (VSA) expressed by chondroitin sulfate A (CSA)-adherent
Plasmodium falciparum
involved in pregnancy-associated malaria (PAM). However, antibody recognition of recombinant products of a specific VSA gene (
2O2var1
) implicated in PAM and transcribed by a CSA-adhering parasite line did not have these characteristics. Furthermore, we could not demonstrate preferential transcription of
2O2var1
in the CSA-adhering line versus the unselected, parental isolate. Our data call for circumspection regarding the molecular identity of the parasite ligand mediating adhesion to CSA in PAM.
Gingipain RgpB Is Excreted as a Proenzyme in the
vimA
-Defective Mutant
Porphyromonas gingivalis
FLL92
Authors: Olango G. Jon , Roy Francis , Sheets Shaun M. , Young Mary K. , Fletcher Hansel M. 
Published: June 2003

ABSTRACT

We have previously shown that the unique
vimA
(virulence-modulating) gene could modulate proteolytic activity in
Porphyromomas gingivalis
. Although a reduction in cysteine protease activity was observed in the
vimA
-defective mutant,
P. gingivalis
FLL92, compared to that of the wild-type strain, no changes were seen in the expression of the gingipain genes. This result might suggest posttranscriptional regulation of protease expression. To determine whether there was a defect in the translation, transport, or maturation of the gingipains,
P. gingivalis
FLL92 was further characterized. In contrast to the wild-type strain, a 90% reduction was seen in both Rgp and Kgp protease activities in strain FLL92 during the exponential growth phase. These activities, however, increased to approximately 60% of that of the wild-type strain during stationary phase. Throughout all the growth phases, Rgp and Kgp activities were mostly soluble, in contrast to those of the wild-type strain. Western blot analyses identified unique Rgp- and Kgp-immunoreactive bands in extracellular protein fractions from FLL92 grown to late exponential phase. Also, the RgpB proenzyme was identified in this fraction by mass spectrometry. In addition, in vitro protease activity could be induced by a urea denaturation-renaturation cycle in this fraction. These results indicate that protease activity in
P. gingivalis
may be growth phase regulated, possibly by multiple mechanisms. Furthermore, the gingipain RgpB is excreted in an inactive form in the
vimA
mutant. In addition, these results provide the first evidence of posttranslational regulation of protease activity in
P. gingivalis
and may suggest an important role for the
vimA
gene in protease activation in this organism.
Combined Treatment with Interleukin-12 and Mebendazole Lessens the Severity of Experimental Eosinophilic Meningitis Caused byAngiostrongylus cantonensisin ICR Mice
Authors: Du Wen-Yuan , Liao Jiunn-Wang , Fan Chia-Kwung , Su Kua-Eyre 
Published: June 2003

ABSTRACTAngiostrongylus cantonensisis the major cause of eosinophilic meningoencephalitis cases in Taiwan. Mice were orally infected with 35 infective larvae. One group of mice were given a single dose of mebendazole (20 mg/kg of body weight) per os at various times and examined at 14 days postinfection (dpi) for worm recovery rate and pathological studies. A 94 to 97% reduction in worm recovery was observed when medication was given at 4 to 5 dpi. Sections of the brains revealed that untreated infected mice developed typical severe eosinophilic meningoencephalitis. Meninges of these mice were thickened by massive infiltration of eosinophils, whereas only moderate pathological change was observed in the brains of mice that were treated with mebendazole at 4 dpi. Infected mice that received daily injections of 10 ng of interleukin-12 (IL-12) only for various numbers of days also exhibited moderate pathological changes in the brain. Eosinophil infiltration in the brains of these mice was low, and severe mechanical injuries in the parenchyma were observed. Treatment with mebendazole in combination with IL-12, however, resulted in low levels of worm recovery and dramatic lessening of the eosinophilic meningitis. A reverse transcriptase PCR assay of mRNA expression in the brain also revealed that the use of IL-12 had shifted the immune response of the mouse from Th2 type to Th1 type. This study could be used in developing strategies for the treatment of human angiostrongylosis.
Cytotoxic Necrotizing Factor 1 Enhances Reactive Oxygen Species-Dependent Transcription and Secretion of Proinflammatory Cytokines in Human Uroepithelial Cells
Authors: Falzano Loredana , Quaranta Maria Giovanna , Travaglione Sara , Filippini Perla , Fabbri Alessia , Viora Marina , Donelli Gianfranco , Fiorentini Carla 
Published: June 2003

ABSTRACT

Uropathogenic
Escherichia coli
strains frequently produce a Rho-activating protein toxin named cytotoxic necrotizing factor type 1 (CNF1). We herein report that CNF1 promotes transcription and release of tumor necrosis factor alpha, gamma interferon, interleukin-6 (IL-6), and IL-8 proinflammatory cytokines and increases the production of reactive oxygen species (ROS) in uroepithelial T24 cells. The antioxidant
N
-acetyl-
l
-cysteine counteracts these phenomena, a fact which suggests a role for ROS-mediated signaling in CNF1-induced proinflammatory cytokine production.
Combined Contributions of Streptolysin O and Streptolysin S to Virulence of Serotype M5Streptococcus pyogenesStrain Manfredo
Authors: Fontaine Michael C. , Lee Jeong Jin , Kehoe Michael A. 
Published: June 2003

ABSTRACTStreptolysin O (SLO) and streptolysin S (SLS) are potent cytolytic toxins produced by almost all clinical isolates of group A streptococci (GAS). Allele-replacement mutagenesis was used to construct nonpolar (in-frame) deletion mutations in thesloandsagBgenes of the serotype M5 GAS strain Manfredo, producing isogenic single and double SLO- and SLS-defective mutants. In contrast to recent reports on SLS-defective insertion mutants (I. Biswas, P. Germon, K. McDade, and J. Scott, Infect. Immun. 69:7029-7038, 2001; Z. Li, D. Sledjeski, B. Kreikemeyer, A.Podbielski, and M. Boyle, J. Bacteriol. 181:6019-6027, 1999), none of the mutants described here had notable pleiotropic effects on the expression of other virulence factors examined. Comparison of isogenic parent and mutant strains in various virulence models revealed no differences in their abilities to multiply in human blood or in their 50% lethal doses (LD50s) upon intraperitoneal infection of BALB/c mice. A single log unit difference in the LD50s of the parent and SLS-defective mutant strains was observed upon infection by the subcutaneous (s.c.) route. Comparisons over a range of infective doses showed that both SLO and SLS contributed to the early stages of infection and to the induction of necrotic lesions in the murine s.c. model. Individually, each toxin made an incremental contribution to virulence that was not apparent at higher infective doses, although the absence of both toxins reduced virulence over the entire dose range examined. Interestingly, in some cases, the contribution of SLO to virulence was clear only from an analysis of the double-mutant strain, highlighting the value of not confining virulence studies to mutant strains defective in the expression of only single virulence factors.
Tripalmitoyl-S-Glyceryl-Cysteine-Dependent OspA Vaccination of Toll-Like Receptor 2-Deficient Mice Results in Effective Protection fromBorrelia burgdorferiChallenge
Authors: Yoder Alyson , Wang Xiaohui , Ma Ying , Philipp Mario T. , Heilbrun Marta , Weis John H. , Kirschning Carsten J. , Wooten R. Mark , Weis Janis J. 
Published: June 2003

ABSTRACTToll-like receptor 2 (TLR2) is a transmembrane signal transducer for tripalmitoyl-S-glyceryl-cysteine (Pam3Cys)-modified lipoproteins, including OspA from the Lyme disease spirocheteBorrelia burgdorferi. The Pam3Cys modification provides adjuvant activity for inducing humoral responses, suggesting that TLR2 could function as the adjuvant receptor for the OspA vaccine. The importance of TLR2 in the humoral response to OspA was confirmed, because overall levels of immunoglobulin G (IgG) were reduced in TLR2-deficient mice, when compared with those in wild-type mice. However, the levels of production of IgG1 were similar in both mouse strains, and the levels of induction of protective immunity were comparable. Unlipidated OspA was not immunogenic in wild-type or TLR2-deficient mice, indicating the lipid modification was active in the absence of TLR2. These findings indicate that the Pam3Cys modification of bacterial lipoprotein has adjuvant properties independent of TLR2 signaling.
Cholera Holotoxin Assembly Requires a Hydrophobic Domain at the A-B5Interface: Mutational Analysis and Development of an In Vitro Assembly System
Authors: Tinker Juliette K. , Erbe Jarrod L. , Hol Wim G. J. , Holmes Randall K. 
Published: June 2003

ABSTRACTCholera toxin (CT) and relatedEscherichia colienterotoxins LTI and LTIIb have a conserved hydrophobic region at the AB5interface postulated to be important for toxin assembly. Hydrophobic residue F223 in the A subunit of CT (CTA) as well as residues 174, L77, and T78 in the B subunit of CT (CTB) were replaced individually with aspartic acid, and the resulting CTA and CTB variants were analyzed for their ability to assemble into holotoxin in vivo. CTA-F223D holotoxin exhibited decreased stability and toxicity and increased susceptibility to proteolysis by trypsin. CTB-L77D was unable to form functional pentamers. CTB-I74D and CTB-T78D formed pentamers that bound to GM1andd-galactose but failed to assemble with CTA to form holotoxin. In contrast, CTB-T78D and CTA-F223H interacted with each other to form a significant amount of holotoxin in vivo. Our findings support the importance of hydrophobic interactions between CTA and CTB in holotoxin assembly. We also developed an efficient method for assembly of CT in vitro, and we showed that CT assembled in vitro was comparable to wild-type CT in toxicity and antigenicity. CTB-I74D and CTB-T78D did not form pentamers or holotoxin in vitro, and CTA-F223D did not form holotoxin in vitro. The efficient system for in vitro assembly of CT described here should be useful for future studies on the development of drugs to inhibit CT assembly as well as the development of chimeric CT-like molecules as potential vaccine candidates.
Yersinia pestisTonB: Role in Iron, Heme, and Hemoprotein Utilization
Authors: Perry Robert D. , Shah Jessica , Bearden Scott W. , Thompson Jan M. , Fetherston Jacqueline D. 
Published: June 2003

ABSTRACTInYersinia pestis, the siderophore-dependent yersiniabactin (Ybt) iron transport system and heme transport system (Hmu) have putative TonB-dependent outer membrane receptors. Here we demonstrate that hemin uptake and iron utilization from Ybt are TonB dependent. However, the Yfe iron and manganese transport system does not require TonB.
Leptin Modulates Neutrophil Phagocytosis ofKlebsiella pneumoniae
Authors: Moore Sharlene I. , Huffnagle Gary B. , Chen Gwo-Hsiao , White Eric S. , Mancuso Peter 
Published: June 2003

ABSTRACTLeptin is a pleiotropic hormone-cytokine known to regulate energy homeostasis and immune function. Neutrophils from leptin-deficient mice exhibited impaired phagocytosis ofKlebsiella pneumoniaeopsonized with serum containing complement and reduced CD11b expression that could be restored with exogenous leptin. These results suggest that leptin is required for normal neutrophil complement-mediated phagocytosis of bacteria.
Antigen Processing of the Heptavalent Pneumococcal Conjugate Vaccine Carrier Protein CRM197Differs Depending on the Serotype of the Attached Polysaccharide
Authors: Leonard Ethan G. , Canaday David H. , Harding Clifford V. , Schreiber John R. 
Published: June 2003

ABSTRACTThe pneumococcal (Pn) conjugate vaccine includes seven different polysaccharides (PS) conjugated to CRM197. Utilizing antigen-processing cells and a CRM197-specific mouse T-cell hybridoma, we found that the serotype of conjugated PnPS dramatically affected antigen processing of CRM197. Unconjugated CRM197and serotype conjugates 14 and 18C were processed more efficiently.
Hearing in hooktip moths (Drepanidae: Lepidoptera)
Authors: Surlykke Annemarie , Yack Jayne E. , Spence Andrew J. , Hasenfuss Ivar 
Published: June 2003

SUMMARY
This study presents anatomical and physiological evidence for a sense of hearing in hooktip moths (Drepanoidea). Two example species, Drepana arcuata and Watsonalla uncinula, were examined. The abdominal ears of drepanids are structurally unique compared to those of other Lepidoptera and other insects, by having an internal tympanal membrane, and auditory sensilla embedded within the membrane. The tympanum is formed by two thin tracheal walls that stretch across a teardrop-shaped opening between dorsal and ventral air chambers in the first abdominal segment. There are four sensory organs (scolopidia) embedded separately between the tympanal membrane layers: two larger lateral scolopidia within the tympanal area, and two smaller scolopidia at the medial margin of the tympanal frame. Sound is thought to reach the tympanal membrane through two external membranes that connect indirectly to the dorsal chamber.
The ear is tuned to ultrasonic frequencies between 30 and 65 kHz, with a best threshold of around 52 dB SPL at 40 kHz, and no apparent difference between genders. Thus, drepanid hearing resembles that of other moths,indicating that the main function is bat detection. Two sensory cells are excited by sound stimuli. Those two cells differ in threshold by approximately 19 dB. The morphology of the ear suggests that the two larger scolopidia function as auditory sensilla; the two smaller scolopidia, located near the tympanal frame, were not excited by sound. We present a biophysical model to explain the possible functional organization of this unique tympanal ear.
Regulation of Pulmonary and Systemic Bacterial Lipopolysaccharide Responses in Transgenic Mice Expressing Human Elafin
Authors: Sallenave J.-M. , Cunningham G. A. , James R. M. , McLachlan G. , Haslett C. 
Published: June 2003

ABSTRACTThe control of lung inflammation is of paramount importance in a variety of acute pathologies, such as pneumonia, the acute respiratory distress syndrome, and sepsis. It is becoming increasingly apparent that local innate immune responses in the lung are negatively influenced by systemic inflammation. This is thought to be due to a local deficit in cytokine responses by alveolar macrophages and neutrophils following systemic bacterial infection and the development of a septic response. Recently, using an adenovirus-based strategy which overexpresses the human elastase inhibitor elafin locally in the lung, we showed that elafin is able to prime lung innate immune responses. In this study, we generated a novel transgenic mouse strain expressing human elafin and studied its response to bacterial lipopolysaccharide (LPS) when the LPS was administered locally in the lungs and systemically. When LPS was delivered to the lungs, we found that mice expressing elafin had lower serum-to-bronchoalveolar lavage ratios of proinflammatory cytokines, including tumor necrosis factor alpha (TNF-α), macrophage inflammatory protein 2, and monocyte chemoattractant protein 1, than wild-type mice. There was a concomitant increase in inflammatory cell influx, showing that there was potential priming of innate responses in the lungs. When LPS was given systemically, the mice expressing elafin had reduced levels of serum TNF-α compared to the levels in wild-type mice. These results indicate that elafin may have a dual function, promoting up-regulation of local lung innate immunity while simultaneously down-regulating potentially unwanted systemic inflammatory responses in the circulation.