bluuebunny/crossref_metadata_2025 huggingface dataset:
Distribution of Bird Diversity in a Vulnerable Neotropical Landscape
Authors: ROBINSON W. DOUGLAS , ANGEHR GEORGE R. , ROBINSON TARA R. , PETIT LISA J. , PETIT DANIEL R. , BRAWN JEFFREY D.
Published: December 2004

Abstract:  Recent withdrawal of the U.S. military from the Republic of Panama has exposed 64,000 ha of lowland forest in the former Canal Zone to possible development. The forests form a 16‐km‐wide strip reaching 65 km from the Caribbean Sea to the Pacific Ocean and function as the water supply for the canal and as home to one of the world's richest terrestrial biotas. We present an overview of the distribution of bird diversity in the forests of the canal area based on 10 years of inventories. A total of 498 terrestrial species has been recorded, of which 177 occur only in lowland forests. More species reside in Caribbean‐ than in Pacific‐slope forests and in the largest forest tracts. The Panamanian government, recognizing the importance of the forests for protection of biodiversity and for proper functioning of the canal, has created two national parks and a national monument in the canal area. One large park, Soberania National Park, currently contains 92% of the region's forest‐dwelling species. Two large tracts on the Caribbean coast, the Achiote Road forest and the Fort Sherman forest, are not designated as national parks but are recognized as important forest areas. Those two forests harbor species found nowhere else in the canal corridor. Extensive fragmentation, disconnection of forested corridors between foothills and lowlands, and anthropogenic degradation of forests near towns have altered regional bird‐community dynamics. Some dynamics occur on large spatial scales, such as the poorly understood movements of elevational and transisthmian migrants. Long‐term maintenance of bird species diversity in the canal area will require preservation of the large forest tracts and reestablishment of a forested connection from the canal corridor lowlands to the Chagres lowlands and foothills in the east. Such conservation activities will be challenging to execute given the region's growing human population and desires for a stronger national economy. We recommend protection of remaining forests and active enforcement of protection laws to reduce hunting and further intrusions.
Do Patients Accept Implantable Atrial Defibrillation Therapy?
Authors: BURNS JASON L. , SEARS SAMUEL F. , SOTILE REBECCA , SCHWARTZMAN DAVID S. , HOYT ROBERT H. , ALVAREZ LUIS G. , UJHELYI MICHAEL R.
Published: December 2004

Introduction: The Medtronic Jewel AF 7250 is an implantable cardioverter defibrillator with atrial and ventricular therapies (ICD‐AT). The ICD‐AT is effective in managing atrial tachyarrhythmias (atrial fibrillation [AF]), but patient acceptance remains an issue. This aim of this study was to measure ICD‐AT acceptance.

Methods and Results: ICD‐AT acceptance was evaluated in 96 patients enrolled in the “Jewel AF‐AF‐Only Study” for ≥3 months of follow‐up (mean 19 months). Patients were mostly men (72%; age 65 ± 12 years). Clinical data and a written survey (75% response rate) were used to quantify demographics, AF frequency and symptoms, atrial defibrillation therapy, quality of life (QOL), psychosocial distress, and ICD‐AT therapy acceptance. From implant to survey, AF symptom and severity scores decreased by 18% (P ≤ 0.05), and QOL (SF‐36) scores increased by 15% to 50% (P ≤ 0.05). ICD‐AT therapy acceptance was high, with 71.3% of patients scoring in the 75th percentile on the Florida Patient Acceptance Survey. ICD‐AT acceptance was correlated with the Physical Component Scale and Mental Health Component Scale scores of the SF‐36 (r = 0.28 and 0.35, respectively). ICD‐AT acceptance was negatively correlated with depressive symptomatology (r =–0.59), trait anxiety (r =–0.48), illness intrusiveness (r =–0.55), and AF symptom and severity scores (r =–0.26). ICD‐AT acceptance did not correlate with preimplant cardioversions, number of atrial shocks, AF episodes detected by the device, or device implant duration.

Conclusion: Most patients accepted ICD‐AT therapy. Patients were more likely to accept ICD‐AT if they had less psychosocial distress, greater QOL, and lower AF symptom burden. (J Cardiovasc Electrophysiol, Vol. 15, pp. 286‐291, March 2004)
Congenital bronchiolo‐alveolar airway malformation in a cynomolgus macaque (Macaca fascicularis)
Authors: Lewis B.S. , Hubbard G.B. , Mense M.G. , Frost P.A.
Published: December 2004

Abstract:  Pulmonary congenital anomalies in animals are rare. Previously reported malformations include accessory lung formation, pulmonary hypoplasia, pulmonary agenesis, and various forms of hamartoma. Congenital bronchiolo‐alveolar airway malformation, a new entity, is described in a 1‐day‐old male cynomolgus macaque. This neonate experienced breathing difficulties shortly after birth and died while therapy was being administered. Grossly, the right lung was markedly increased in size, firm, and pink. Histopathologically, sections of right lung showed irregular bronchiole‐like and alveolus‐like structures. There was marked widening of alveolar septae by loosely arranged mesenchymal cells and many centrally located capillaries. Alveoli were lined by cuboidal epithelial cells. There were scattered islands of immature cartilage. A grossly enlarged lung containing bronchiole‐like and alveolus‐like structures, immature cartilage islands, and many capillaries within alveolar septae on histopathologic examination, is inconsistent with previously described congenital pulmonary anomalies in animals and humans.
Genetic and environmental (inter)actions in male mouse lines selected for aggressive and nonaggressive behavior
Authors: Nyberg J. , Sandnabba K. , Schalkwyk L. , Sluyter F.
Published: December 2004

The purpose of this study was to investigate the effects of genetic and environmental factors, as well as their interaction, in the etiology of aggressive behavior in two mouse lines bidirectionally selected for offensive aggression. To this end, we raised the Finnish TA (aggressive) and TNA (nonagressive) selection lines either in isolation or in cohabitation with a female after weaning. At the age of 3 months we determined their aggressive behavior in three paradigms (intruder resident, neutral cage, resident intruder) against a male standard opponent. We also determined the animals' aggressive behavior against a female mouse. The results show genetic and environmental effects, as well as gene–environment interaction. We see prominent genotype effects under all conditions but each test is sensitive to a specific combination of environmental effects. A particularly noteworthy result is that variation in the unusual behavior of aggression towards a female is largely explained by the interaction of genotype with isolation. We also examined whether test experience influenced the outcome of an encounter between an experimental animal and an opponent, and found that this factor should not be underestimated, its effect size and direction depending on the type of paradigm and way of housing. These data suggest that the identification of genes underlying aggressive behavior in mice is by no means straightforward and that the result of this search will depend on the environmental design of the study (type of paradigm, housing conditions). These data also suggest that the use of ‘test battery’ mice might produce different results than the use of test‐naïve animals.
Axially symmetric semi‐infinite domain models of microdialysis and their application to the determination of nutritive flow in rat muscle
Authors: Roberts Jason L. , Newman John M. B. , Warner Roland , Rattigan Stephen , Clark Michael G.
Published: December 2004

Theoretical models for the description of microdialysis outflow:inflow (O/I) ratio for 3H2O and [14C]ethanol were developed, taking into account the nutritive fraction of total blood flow in muscle. The models yielded an approximately exponential decay expression for the O/I ratio, dependent on the physical dimensions of a linear probe (length and radius), the flow rate through the probe, muscle blood flow (including the nutritive fraction) and the diffusion coefficients for the tracer in the probe and muscle. The models compared favourably with experimental data from the constant‐flow perfused rat hindlimb. Estimates of the nutritive fraction of total blood flow from experimental data were determined by minimizing the error between model and experimental data. The nutritive fraction was found to be 0.22 ± 0.04 under basal perfusion conditions. When 70 nm noradrenaline (norepinephrine) was included in the perfusion medium, the nutritive fraction was 0.91 ± 0.06 (P < 0.05). The inclusion of 300 nm serotonin, decreased the nutritive fraction to 0.05 ± 0.01 (P < 0.05). This model can be applied to the determination of nutritive fraction of skeletal muscle blood flow in physiologically relevant microvascular conditions such as during exercise and in disease states.
Identification of Novel Inhibitors of Bacterial Translation Elongation Factors
Authors: Jayasekera Maithri M. K. , Onheiber Keysha , Keith John , Venkatesan Hariharan , Santillan Alejandro , Stocking Emily M. , Tang Liu , Miller Jennifer , Gomez Leslie , Rhead Brooke , Delcamp Tavner , Huang Shaoming , Wolin Ronald , Bobkova Ekaterina V. , Shaw Karen Joy
Published: December 2004

Bacterial elongation factor Tu (EF-Tu) and EF-Ts are interacting proteins involved in polypeptide chain elongation in protein biosynthesis. A novel scintillation proximity assay for the detection of inhibitors of EF-Tu and EF-Ts, as well as the interaction between them, was developed and used in a high-throughput screen of a chemical library. Several compounds from a variety of chemical series with inhibitory properties were identified, including certain indole dipeptides, benzimidazole amidines, 2-arylbenzimidazoles, N-substituted imidazoles, and N-substituted guanidines. The in vitro activities of these compounds were confirmed in a coupled bacterial transcription-translation assay. Several indole dipeptides were identified as inhibitors of bacterial translation, with compound 2 exhibiting a 50% inhibitory concentration of 14 μM and an MIC for
S. aureus
ATCC 29213 of 5.6 μg/ml. Structure-activity relationship studies around the dipeptidic indoles generated additional analogs with low micromolar MICs for both gram-negative and gram-positive bacteria. To assess the specificity of antibacterial action, these compounds were evaluated in a metabolic labeling assay with
Staphylococcus aureus
. Inhibition of translation, as well as limited effects on other macromolecular pathways for some of the analogs studied, indicated a possible contribution from a non-target-based antibacterial mechanism of action.
Pharmacokinetics of Oritavancin in Plasma and Skin Blister Fluid following Administration of a 200-Milligram Dose for 3 Days or a Single 800-Milligram Dose
Authors: Fetterly Gerald J. , Ong Christine M. , Bhavnani Sujata M. , Loutit Jeffrey S. , Porter Steven B. , Morello Lisa G. , Ambrose Paul G. , Nicolau David P.
Published: December 2004

Oritavancin is a novel glycopeptide currently being developed for the treatment of complicated skin and skin structure infections (cSSSI), including those caused by multidrug resistant gram-positive pathogens. The disposition of oritavancin in skin structures was investigated using a cantharide-induced blister fluid model. Seventeen healthy male subjects received oritavancin, but only 16 subjects were evaluated after one subject discontinued study drug. Each subject (eight per dose group) received 200 mg of oritavancin once a day for 3 days (group A) or 800 mg as one single dose (group B). Group A plasma samples and exudates from blister fluid were collected on days 3, 4, 7, 9, and 12 and on days 3, 4, 7, and 9, respectively. Group B samples and exudates were collected on days 1, 2, 5, 7, and 10 and on days 1, 2, 5, and 7, respectively. Drug concentrations were determined using a liquid chromatography-tandem mass spectrometry assay and, subsequently, pharmacokinetic analysis was performed. Differences between treatment groups in ratios for area under the concentration-time curve for blister fluid and plasma (AUC
blister fluid
/AUC
plasma
ratios) were evaluated using a
t
test (α = 0.05). Mean maximum concentration of drug in plasma or blister fluid was approximately 8-fold and 11-fold higher in plasma than in blister fluid following the 200- or 800-mg doses of oritavancin, respectively. Mean AUC
blister fluid
/AUC
plasma
ratios at 24 h were 0.190 (standard deviation [SD], 0.052) and 0.182 (SD, 0.062) for groups A and B, respectively (
P
= 0.791). To place these results in a clinical context, mean drug concentrations in blister fluid exceed the oritavancin MIC at which 90% of strains are inhibited of
Staphylococcus aureus
(2 μg/ml) by approximately 2- to 5.5-fold at 12 h and 1.5- to 3-fold at 24 h following administration of both dosing regimens. These results support the potential use of oritavancin for the treatment of cSSSI.
Ecological Effects of Perorally Administered Pivmecillinam on the Normal Vaginal Microflora
Authors: Sullivan Åsa , Fianu-Jonasson Aino , Landgren Britt-Marie , Nord Carl Erik
Published: December 2004

The knowledge of the effects of antimicrobial agents on the normal vaginal microflora is limited. The objective of the present study was to study the ecological impact of pivmecillinam on the normal vaginal microflora. In 20 healthy women, the estimated day of ovulation was determined during three subsequent menstrual cycles. Microbiological and clinical examinations were performed on the estimated day of ovulation and on day 3 in all cycles and also on day 7 after ovulation in cycles 1 and 2. Anaerobic and facultative anaerobic gram-positive rods, mainly species of lactobacilli and actinomycetes, dominated the microflora. One woman was colonized on the third day of administration with a resistant
Escherichia coli
strain, and
Candida albicans
was detected in one woman on days 3 and 7 in cycle 2. No other major changes in the normal microflora occurred during the study. Administration of pivmecillinam had a minor ecological impact on the normal vaginal microflora.
Pharmacodynamic Profile of Ertapenem against
Klebsiella pneumoniae
and
Escherichia coli
in a Murine Thigh Model
Authors: Maglio Dana , Banevicius Mary Anne , Sutherland Christina , Babalola Chinedum , Nightingale Charles H. , Nicolau David P.
Published: December 2004

The pharmacodynamic profile of ertapenem was evaluated in a neutropenic mouse thigh infection model. Extended-spectrum beta-lactamase (ESBL)-positive and ESBL-negative clinical strains of
Escherichia coli
and
Klebsiella pneumoniae
were studied. MICs ranged from 0.0078 to 0.06 μg/ml with standard inoculum tests. Ertapenem doses were administered once to five times daily to achieve various exposures, reported as the percentage of the dosing interval that the concentration of free ertapenem was in excess of the MIC (%
T
>MIC
free
). Mean values for the static exposure and 80% maximally effective exposure (ED
80
) were 19% (range, 2 to 38%) and 33% (range, 13 to 65%)
T
>MIC
free
, respectively. Differences in exposure requirements based on the presence of an ESBL resistance mechanism or bacterial species were not evident. In addition, experiments using a 100-fold higher inoculum did not decrease the magnitude of the reduction in bacterial density from baseline achieved compared to lower-inoculum studies. The pharmacodynamic parameter of %
T
>MIC
free
correlated well with bactericidal activity for all isolates, and the static and ED
80
exposures are consistent with those reported previously for carbapenems.
Pharmacodynamics of Cefepime Alone and in Combination with Various Antimicrobials against Methicillin-Resistant
Staphylococcus aureus
in an In Vitro Pharmacodynamic Infection Model
Authors: Huang Vanthida , Rybak Michael J.
Published: December 2004

Treatment options for gram-positive resistant bacteria are limited; therefore, efforts to evaluate therapy options in the critical care population are warranted. Cefepime has broad-spectrum activity against gram-negative and gram-positive organisms. We have previously demonstrated that the combination of cefepime with vancomycin, linezolid, or quinupristin-dalfopristin had an improved or enhanced effect against methicillin-resistant
Staphylococcus aureus
(MRSA). We investigated various regimens of cefepime alone and in combination against two clinical MRSA isolates (R2481 and R2484) in an established in vitro pharmacodynamic model. Human pharmacokinetic regimen simulations were as follows: cefepime, 2 g every 8 h (q8h) (C8) and 12 h (C12), continuous-infusion 2-g loading dose followed by 4 g alone or in combination with gentamicin and tobramycin (1.0 or 2.0 [G1 and G2 or TB1 and TB2] mg/kg of body weight q12h and 5.0 [G5 or TB5] mg/kg q24h), arbekacin (ARB) (100 mg q12h), linezolid (LIN) (600 mg q12h), tigecycline (TIG) (100 mg q24h), or daptomycin (DAP) (6 mg/kg q24h) for 48 h. The MICs for cefepime, gentamicin, tobramycin, ARB, LIN, TIG, and DAP for the two clinical MRSA isolates (R2481 and R2484) were 4 and 4, 0.25 and 0.5, 128 and 0.5, 0.5 and 0.125, 2 and 4, 0.25 and 0.25, and 0.0625 and 0.125 μg/ml, respectively. At 48 h, combinations of C12 and C8 plus ARB, G1, or G5 (range, −2.05- to −4.32-log
10
decrease) demonstrated enhanced lethality against R2481 (resistant to tobramycin) (
P
< 0.05). A similar relationship was demonstrated against R2484 with cefepime plus ARB, gentamicin, or tobramycin (range, −2.05- to −3.63-log
10
decrease) (
P
< 0.05). A 99.9% kill was achieved with cefepime plus aminoglycoside combinations as early as 2 h and maintained throughout the 48-h period. TIG was antagonistic when combined with C12 against both isolates. DAP alone achieved 99.9% kill for up to 48 h for both isolates and was the most active agent against R2481 and R2484 (−2.89- and −3.61-log
10
decrease at 48 h); therefore, combination therapy did not enhance lethality. Overall, the most potent combinations noted were cefepime in combination with low- and high-dose aminoglycosides. Further investigations with combination therapies are warranted.
Single-Dose Safety and Pharmacokinetics of Amprenavir (141W94), a Human Immunodeficiency Virus Type 1 (HIV-1) Protease Inhibitor, in HIV-Infected Children
Authors: Yogev Ram , Kovacs Andrea , Chadwick Ellen G. , Homans James D. , Lou Yu , Symonds William T.
Published: December 2004

A phase I, open-label, dose-escalating trial was conducted to evaluate the safety, tolerability, and pharmacokinetics of single, oral doses of amprenavir (141W94), a potent inhibitor of human immunodeficiency virus type 1 (HIV-1) protease, in 20 HIV-infected children 4 to 12 years of age. The doses of amprenavir evaluated, 5, 10, 15, and 20 mg/kg of body weight, were comparable to those evaluated in adult phase I and II studies. The most common clinical adverse event associated with amprenavir, administered as soft gelatin capsules, was nausea. Amprenavir was rapidly absorbed, with a mean time to maximum concentration (
T
max
) occurring 0.95 to 1.58 h after dosing. The area under the concentration-time curve (AUC
0
→
∞
) was dose proportional, and the mean maximum plasma concentration (
C
max
) increased linearly in a less than dose-proportional manner. Amprenavir was eliminated relatively slowly, with a mean terminal-phase half-life (
t
1/2
) of 6.17 to 8.28 h. The
t
1/2
, apparent total clearance, and apparent volume of distribution during the elimination phase were dose independent. Considerable interpatient variability was seen for all pharmacokinetic parameters of amprenavir. The results of this study suggest that 20 mg of amprenavir/kg administered twice a day should be used in future pediatric studies.
Emergence of CTX-M-15-Producing Enterobacteria in Cameroon and Characterization of a
bla
CTX-M-15
-Carrying Element
Authors: Gangoue-Pieboji J. , Miriagou V. , Vourli S. , Tzelepi E. , Ngassam P. , Tzouvelekis L. S.
Published: December 2004

CTX-M-15-producing
Klebsiella pneumoniae
and
Escherichia coli
emerged recently in Cameroon. CTX-M-15 was encoded by two different multiresistance plasmids, of which one carried an IS
Ecp1
-
bla
CTX-M-15
element flanked by a 5-bp target site duplication and inserted within a Tn
2
-derived sequence. A truncated form of this element in the second plasmid was identified.
Detection and Quantification of Macrolide Resistance Mutations at Positions 2058 and 2059 of the 23S rRNA Gene by Pyrosequencing
Authors: Haanperä Marjo , Huovinen Pentti , Jalava Jari
Published: December 2004

A pyrosequencing method for detection and quantification of macrolide resistance mutations at positions 2058 and 2059 (
Escherichia coli
numbering) of the 23S rRNA gene is described. The method was developed and tested for
Streptococcus pneumoniae
,
Streptococcus pyogenes
,
Mycobacterium avium
,
Campylobacter jejuni
, and
Haemophilus influenzae
.
Pharmacodynamic Evaluation of Extending the Administration Time of Meropenem using a Monte Carlo Simulation
Authors: Lomaestro Ben M. , Drusano G. L.
Published: December 2004

A Monte Carlo simulation demonstrated that 1 g of meropenem (MEM) every 8 h (q8h) (3-h infusion) has a higher target attainment rate against
Pseudomonas aeruginosa
than either 500 mg of MEM q8h (3-h infusion) or 0.5 g of imipenem-cilastatin (I-C) q6h (1-h infusion). For other pathogens, 500 mg of MEM q8h was equivalent or superior to I-C.
A Mutant of Staphylococcal Enterotoxin C Devoid of Bacterial Superantigenic Activity Elicits a Th2 Immune Response for Protection againstStaphylococcus aureusInfection
Authors: Hu Dong-Liang , Cui Jing-Chun , Omoe Katsuhiko , Sashinami Hiroshi , Yokomizo Yuichi , Shinagawa Kunihiro , Nakane Akio
Published: December 2004

Staphylococcal enterotoxin C (SEC), a bacterial superantigenic exotoxin, is commonly produced by invasiveStaphylococcus aureusisolates, especially methicillin-resistant strains and isolates from animal diseases. We constructed and expressed a nontoxic mutant SEC (mSEC) and investigated whether immunization with mSEC, which is devoid of superantigenic activity, can protect againstS. aureusinfection. Mice were immunized with mSEC and challenged with viableS. aureus. The bacterial counts in the organs of mSEC-immunized mice were significantly lower and the survival rate was higher than the corresponding values for the control group. Immunization with mSEC strongly induced the production of T-helper 2 type antibodies, immunoglobulin G1, and immunoglobulin G2b. The production of interleukin-10 (IL-10) and IL-4 was significantly greater in immunized mice challenged withS. aureusthan in the control mice, whereas the production of gamma interferon (IFN-γ) was significantly decreased in the immunized mice. The cytokine response in a spleen cell culture that was stimulated with heat-killedS. aureusor SEC showed that immunization with mSEC inhibited IFN-γ production and up-regulated IL-10 production in vitro. Furthermore, IFN-γ and tumor necrosis factor alpha production in vitro was significantly inhibited by sera from mSEC-immunized mice but not by sera from control mice. These results suggest that immunization with mSEC devoid of superantigenic properties provides protection againstS. aureusinfection and that the protection might be mediated by SEC-specific neutralizing antibodies.
Trigger Factor inStreptococcus mutansIs Involved in Stress Tolerance, Competence Development, and Biofilm Formation
Authors: Wen Zezhang T. , Suntharaligham Prashanth , Cvitkovitch Dennis G. , Burne Robert A.
Published: December 2004

Trigger factor is a ribosome-associated peptidyl-prolylcis/transisomerase that is highly conserved in most bacteria. A gene, designatedropA, encoding an apparent trigger factor homologue, was identified inStreptococcus mutans, the primary etiological agent of human dental caries. Inactivation ofropAhad no major impact on growth rate in planktonic cultures under the conditions tested, although the RopA-deficient mutant formed long chains in broth. Deficiency of RopA decreased tolerance to acid killing and to oxidative stresses induced by hydrogen peroxide and paraquat, and it reduced transformation efficiency about 200-fold. Addition of synthetic competence-stimulating peptide to the culture medium enhanced transformability of both the mutant and wild-type strains, although theropAstrain did not attain levels of competence observed for the parent. Loss of RopA decreased the capacity ofS. mutansto form biofilms by over 80% when cultivated in glucose, but it increased biofilm formation by over 50% when sucrose was provided as the carbohydrate source. Western blot analysis revealed that the expression of glucosyltransferases B and D was lower in the RopA-deficient mutant. These results suggest that RopA is a key regulator of acid and oxidative stress tolerance, genetic competence, and biofilm formation, all critical virulence properties ofS. mutans.
Both Innate Immunity and Type 1 Humoral Immunity toStreptococcus pneumoniaeAre Mediated by MyD88 but Differ in Their Relative Levels of Dependence on Toll-Like Receptor 2
Authors: Khan Abdul Q. , Chen Quanyi , Wu Zheng-Qi , Paton James C. , Snapper Clifford M.
Published: December 2004

Little is known regarding the role of Toll-like receptors (TLRs) in regulating protein- and polysaccharide-specific immunoglobulin (Ig) isotype production in response to an in vivo challenge with an extracellular bacterium. In this report we demonstrate that MyD88−/−, but not TLR2−/−, mice are markedly defective in their induction of multiple splenic proinflammatory cytokine- and chemokine-specific mRNAs after intraperitoneal (i.p.) challenge with heat-killedStreptococcus pneumoniaecapsular type 14 (S. pneumoniaetype 14). This is correlated with analogous responses in splenic cytokine protein release in vitro following addition ofS. pneumoniaetype 14. Consistent with these data, naïve MyD88−/−, but not TLR2−/−, mice are more sensitive to killing following i.p. challenge with liveS. pneumoniaetype 14, relative to responses in wild-type mice. However, prior immunization of MyD88−/−mice with heat-killedS. pneumoniaetype 14 protects against an otherwise-lethal challenge with liveS. pneumoniaetype 14. Surprisingly, both MyD88−/−and TLR2−/−mice exhibit striking and equivalent defects in elicitation of type 1 IgG isotypes (IgG3, IgG2b, and IgG2a), but not the type 2 IgG isotype, IgG1, specific for several protein and polysaccharide antigens, in response to i.p. challenge with heat-killedS. pneumoniaetype 14. Of note, the type 1 IgG isotype titers specific for pneumococcal surface protein A are reduced in MyD88−/−mice but not TLR2−/−mice. These data suggest that distinct TLRs may differentially regulate innate versus adaptive humoral immunity to intactS. pneumoniaeand are the first to implicate a role for TLR2 in shaping an in vivo type 1 IgG humoral immune response to a gram-positive extracellular bacterium.
Enhanced Immunoglobulin A Response and Protection againstSalmonella entericaSerovar Typhimurium in the Absence of the Substance P Receptor
Authors: Walters Nancy , Trunkle Theresa , Sura Michael , Pascual David W.
Published: December 2004

The development of the neurokinin-1 receptor-deficient (NK1R−/−) mouse permitted inquiry into the regulation of secretory immunoglobulin A (S-IgA) responses by substance P (SP) after oral immunization with aSalmonella entericaserovar Typhimurium vector expressing colonization factor antigen I (CFA/I) from enterotoxigenicEscherichia coli. In NK1R−/−mice, mucosal and serum IgA anti-CFA/I fimbrial responses were augmented, while secreted IgG anti-CFA/I fimbrial responses remained unaffected compared to those of BALB/c (NK1R+/+) mice. Supportive antibody-forming cells were present in the small intestinal lamina propria and spleen. To gain insight as to why the augmented S-IgA responses occurred, minimally, the responses were not attributed to differences in vaccine colonization of Peyer's patch (PP) and spleen or in their respective tissue weights. However, these S-IgA responses were supported by increased numbers of PP CD4+T helper (Th) cells secreting interleukin-5 (IL-5) and IL-6 and splenic CD4+Th cells secreting IL-6 compared to NK1R+/+mice. Challenge of naive NK1R−/−mice with wild-typeSalmonellashowed improved median survival compared to naive NK1R+/+mice. Data from peritoneal macrophage infection studies suggest that this survival is in part contributed by increased IL-10 production. Oral vaccination withSalmonellaCFA/I orSalmonellavector showed no significant differences in conferred protection against wild-type challenge for either NK1R−/−or NK1R+/+mice. Thus, these studies suggest that SP mediation contributes to proinflammatory responses toSalmonellainfections.
The Cytolethal Distending Toxin Induces Receptor Activator of NF-κB Ligand Expression in Human Gingival Fibroblasts and Periodontal Ligament Cells
Authors: Belibasakis G. N. , Johansson A. , Wang Y. , Chen C. , Kalfas S. , Lerner U. H.
Published: December 2004

Actinobacillus actinomycetemcomitansis associated with localized aggressive periodontitis, a disease characterized by rapid loss of the alveolar bone surrounding the teeth. Receptor activator of NF-κB Ligand (RANKL) and osteoprotegerin (OPG) are two molecules that regulate osteoclast formation and bone resorption. RANKL induces osteoclast differentiation and activation, whereas OPG blocks this process by acting as a decoy receptor for RANKL. The purpose of this study was to investigate the effect ofA. actinomycetemcomitanson the expression of RANKL and OPG in human gingival fibroblasts and periodontal ligament cells. RANKL mRNA expression was induced in both cell types challenged byA. actinomycetemcomitansextract, whereas OPG mRNA expression remained unaffected. Cell surface RANKL protein was also induced byA. actinomycetemcomitans, whereas there was no change in OPG protein secretion. A cytolethal distending toxin (Cdt) gene-knockout strain ofA. actinomycetemcomitansdid not induce RANKL expression, in contrast to its wild-type strain. Purified Cdt fromHaemophilus ducreyialone, or in combination with extract from theA. actinomycetemcomitans cdtmutant strain, induced RANKL expression. Pretreatment ofA. actinomycetemcomitanswild-type extract with Cdt antiserum abolished RANKL expression. In conclusion,A. actinomycetemcomitansinduces RANKL expression in periodontal connective tissue cells. Cdt is crucial for this induction and may therefore be involved in the pathological bone resorption during the process of localized aggressive periodontitis.
Optimization ofSalmonella entericaSerovar Typhi ΔaroCΔssaVDerivatives as Vehicles for Delivering Heterologous Antigens by Chromosomal Integration and In Vivo Inducible Promoters
Authors: Stratford Richard , McKelvie Nicola D. , Hughes Nicky J. , Aldred Emma , Wiseman Claire , Curtis Johanna , Bellaby Trevor , Bentley Matt , Hindle Zoë , Brennan Frank R. , Chatfield Steven N. , Dougan Gordon , Khan Shahid A.
Published: December 2004

Novel candidate live oral vaccines based on aSalmonella entericaserovar Typhi ZH9 (Ty2 ΔaroCΔssaV) derivative that directed the expression of either the B subunit ofEscherichia coliheat-labile toxin or hepatitis B virus core antigen from the bacterial chromosome using the in vivo induciblessaGpromoter were constructed. The levels of attenuation of the twoS. entericaserovar Typhi ZH9 derivatives were similar to that of the parent as assessed by measuring the replication of bacteria within human macrophage-like U937 cells. The expression of heterologous antigen in the respectiveS. entericaserovar Typhi ZH9 derivatives was up-regulated significantly within U937 cells compared to similarS. entericaserovar Typhi ZH9 derivative bacteria grown in modified Luria-Bertani broth supplemented with aromatic amino acids. Immunization of mice with theseS. entericaserovar Typhi ZH9 derivatives stimulated potent antigen-specific serum immunoglobulin G responses to the heterologous antigens.
Use of Phage Display To Identify Potential
Pseudomonas aeruginosa
Gene Products Relevant to Early Cystic Fibrosis Airway Infections
Authors: Beckmann Christiane , Brittnacher Mitchell , Ernst Robert , Mayer-Hamblett Nicole , Miller Samuel I. , Burns Jane L.
Published: December 2004

Pseudomonas aeruginosa
airway infections are a major cause of morbidity and mortality in patients with cystic fibrosis. Treatment of established infections is difficult, even with microbiologically active agents. Thus, prevention of infection is an important goal of management. Isolates from cystic fibrosis patients appear to originate from the environment but adapt to the milieu of the airway of the cystic fibrosis patient and evolve toward a common phenotype. Identification of the antigens expressed early in infection may lead to novel targets for vaccine development. Immunogenic peptides were identified in a J404 random nonapeptide phage display library with serum from cystic fibrosis patients obtained within the first year of
P. aeruginosa
infection. One hundred sixty-five reactive clones were verified by plaque lift assays, and their inserts were sequenced. The sequenced nonapeptides were compared with the published sequence of strain PAO1, identifying homologies to 76 genes encoding outer membrane and secreted proteins. The majority of these were proteins involved in small-molecule transport, membrane structural proteins, and secreted factors. An in silico analysis was performed that suggested that the occurrence of multiple matches to predominantly outer membrane and secreted proteins was not attributable to random chance. Finally, gene expression array data from early isolates of
P. aeruginosa
from cystic fibrosis patients was compared with the results from phage display analysis. Eleven outer membrane and secreted proteins were common between the two data sets. These included genes involved in iron acquisition, antibiotic efflux, fimbrial biogenesis, and pyocin synthesis. These results demonstrate the feasibility and validity of this novel approach and suggest potential targets for future development.
Abundant Secretion of Bioactive Interleukin-1β by Human Macrophages Induced byActinobacillus actinomycetemcomitansLeukotoxin
Authors: Kelk P. , Claesson R. , Hänström L. , Lerner U. H. , Kalfas S. , Johansson A.
Published: December 2004

Actinobacillus actinomycetemcomitansproduces a leukotoxin that selectively kills human leukocytes. Recently, we reported that macrophages are highly sensitive to leukotoxin and that their lysis involves activation of caspase 1. In this study, we show that leukotoxin also induces the production and release of proinflammatory cytokines from human macrophages. The macrophages were challenged with leukotoxin or lipopolysaccharide (LPS) fromA. actinomycetemcomitansor LPS fromEscherichia coli, and the production and secretion of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor alpha (TNF-α) were determined at the mRNA and protein levels by reverse transcription-PCR and enzyme-linked immunosorbent assay, respectively. Leukotoxin (1 to 30 ng/ml) induced abundant production and secretion of IL-1β, while the effects on IL-6 and TNF-α production were limited. Leukotoxin (1 ng/ml) caused a 10-times-higher release of IL-1β than did LPS (100 ng/ml). The secreted IL-1β was mainly the bioactive 17-kDa protein. At higher concentrations (>30 ng/ml), leukotoxin caused secretion of mainly inactive cytokine, the 31-kDa pro-IL-1β. The presence of specific antibodies to IL-1β or of a caspase 1 inhibitor blocked the secretion and production of the cytokine. Supernatants of leukotoxin-challenged macrophages stimulated bone resorption when tested in a mouse calvarial model. The activity could be blocked by an IL-1 receptor antagonist or specific antibodies to IL-1β. We concluded thatA. actinomycetemcomitansleukotoxin can trigger abundant production and secretion of bioactive IL-1β by human macrophages, which is mediated by activation of caspase 1.
Functional Regions of thePseudomonas aeruginosaCytotoxin ExoU
Authors: Rabin Shira D. P. , Hauser Alan R.
Published: December 2004

ExoU, a potent patatin-like phospholipase, causes rapid cell death following its injection into host cells by thePseudomonas aeruginosatype III secretion system. To better define regions of ExoU required for cytotoxicity, transposon-based linker insertion mutagenesis followed by site-directed mutagenesis of individual residues was employed by using aSaccharomyces cerevisiaemodel system. Random insertion of five amino acids identified multiple regions within ExoU that are required for cell killing. Five regions were chosen for further characterization: three corresponded to the oxyanion hole, hydrolase motif, and catalytic aspartate motif of the patatin-like domain within the N-terminal half of ExoU; one corresponded to an uncharacterized part of the patatin-like domain; and one corresponded to a region near the C terminus. Specific individual amino acid substitutions in each of the four N-terminal regions prevented killing of yeast and significantly reduced phospholipase activity. Whereas five amino acid insertions in the fifth region near the C terminus markedly reduced cytotoxicity and phospholipase activity, substitution of individual amino acids did not abolish either activity. To determine whether each of the five identified regions of ExoU was also essential for cytotoxicity in human cells, representative mutant forms of ExoU fused to green fluorescent protein were expressed in HeLa cells. These variants of ExoU were readily visualized and caused minimal cytotoxicity to HeLa cells, while wild-type ExoU fused to green fluorescent protein induced significant cell lysis and no detectable fluorescence. Thus, a minimum of five regions, including one which is well removed from the patatin-like domain, are required for the cytotoxicity and phospholipase activity of ExoU.
Characterization of an ExoS Type III Translocation-Resistant Cell Line
Authors: Rucks Elizabeth A. , Olson Joan C.
Published: December 2004

Pseudomonas aeruginosaExoS is a type III-secreted type III-secreted, bifunctional protein that causes diverse effects on eukaryotic cell function. The coculture ofP. aeruginosastrains expressing ExoS with HL-60 myeloid cells revealed the cell line to be resistant to the toxic effects of ExoS. Differentiation of HL-60 cells with phorbol 12-myristate 13-acetate (TPA) rendered the cell line sensitive to ExoS. To understand the cellular basis for the alteration in sensitivity, undifferentiated and TPA-differentiated HL-60 cells were compared for differences in bacterial adherence, type III secretion induction, and ExoS translocation. These comparisons found that ExoS was translocated more efficiently in TPA-differentiated HL-60 cells than in undifferentiated cells. The studies support the ability of eukaryotic cells to influenceP. aeruginosaTTS at the level of membrane translocation.
Reduced Local Growth and Spread but Preserved Pathogenicity of a Δ
purC Mycobacterium tuberculosis
Auxotrophic Mutant in Gamma Interferon Receptor-Deficient Mice after Aerosol Infection
Authors: Brown Najmeeyah , Jacobs Muazzam , Parida Shreemanta K. , Botha Tania , Santos Aldina , Fick Lizette , Gicquel Brigitte , Jackson Mary , Quesniaux Valerie , Ryffel Bernhard
Published: December 2004

We compared the growth levels and pathogenicities of the
Mycobacterium tuberculosis
MT103 clinical strain with those of the Δ
purC
mutant strain MYC1551, which is auxotrophic for purine in wild-type and gamma interferon receptor (IFN-γR)-deficient mice. The Δ
purC
strain MYC1551 grew initially in both wild-type and IFN-γR-deficient mice upon aerosol infection, but it grew much less than strain MT103 did. Despite the comparable bacterial burdens of the mice, IFN-γR-deficient mice succumbed to infection with Δ
purC
strain MYC1551 from necrotic pneumonia within 6 weeks of those infected with MT103. In conclusion, the Δ
purC
mutant MYC1551 displays reduced growth but retains pathogenicity. Therefore, the use of mutant strains of
M. tuberculosis
as live vaccines may not be recommended.
Neutralizing Antibodies Elicited by Immunization of Monkeys with DNA Plasmids and Recombinant Adenoviral Vectors Expressing Human Immunodeficiency Virus Type 1 Proteins
Authors: Mascola John R. , Sambor Anna , Beaudry Kristin , Santra Sampa , Welcher Brent , Louder Mark K. , VanCott Thomas C. , Huang Yue , Chakrabarti Bimal K. , Kong Wing-Pui , Yang Zhi-Yong , Xu Ling , Montefiori David C. , Nabel Gary J. , Letvin Norman L.
Published: December 2004

Immunization with recombinant serotype 5 adenoviral (rAd5) vectors or a combination of DNA plasmid priming and rAd5 boosting is known to elicit potent immune responses. However, little data exist regarding these immunization strategies and the development of anti-human immunodeficiency virus type 1 (HIV-1) neutralizing antibodies. We used DNA plasmids and rAd5 vectors encoding the HIV-1 89.6P or chimeric HxB2/BaL envelope glycoprotein to immunize macaque monkeys. A single rAd5 immunization elicited anti-Env antibody responses, but there was little boosting with subsequent rAd5 immunizations. In contrast, rAd5 boosting of DNA-primed monkeys resulted in a rapid rise in antibody titers, including the development of anti-HIV-1 neutralizing antibodies. The potency and breadth of neutralization were evaluated by testing plasma against a panel of 14 clade B primary isolates. Moderate levels of plasma neutralizing activity were detected against about one-third of the viruses tested, and immunoglobulin G fractionation demonstrated that virus neutralization was antibody mediated. After a challenge with a chimeric simian-human immunodeficiency virus (SHIV89.6P), an anamnestic neutralizing antibody response was observed, although the breadth of the response was limited to the subset of viruses that were neutralized after the primary immunization. These data are the first detailed description of the anti-HIV-1 neutralizing antibody response in nonhuman primates elicited by DNA and rAd5 immunization. In addition to the well-established ability of DNA priming and rAd5 boosting to elicit potent anti-HIV-1 cellular immune responses, this immunization strategy elicits anti-HIV-1 neutralizing antibodies and therefore can be used to study novel Env immunogens designed to elicit more potent neutralizing antibodies.
Quantification of the Effects on Viral DNA Synthesis of Reverse Transcriptase Mutations Conferring Human Immunodeficiency Virus Type 1 Resistance to Nucleoside Analogues
Authors: Bouchonnet Francine , Dam Elisabeth , Mammano Fabrizio , de Soultrait Vaea , Henneré Gaëlle , Benech Henri , Clavel François , Hance Allan J.
Published: December 2004

Human immunodeficiency virus type I (HIV-1) reverse transcriptase (RT) resistance mutations reduce the susceptibility of the virus to nucleoside analogues but may also impair viral DNA synthesis. To further characterize the effect of nucleoside analogue resistance mutations on the efficiency and kinetics of HIV-1 DNA synthesis and to evaluate the impact of the depletion of deoxynucleoside triphosphates (dNTP) on this process, DNA synthesis was evaluated by allowing DNA synthesis to proceed with natural HIV-1 templates and primers, either within permeabilized viral particles or in newly infected cells, and quantifying the products by real-time PCR. Three recombinant viruses derived from three pNL4-3 molecular clones expressing mutations associated with resistance to zidovudine: a clone expressing RT mutation M184V, a clone expressing mutations M41L plus T215Y (M41L+T215Y), and clinical isolate BV34 (carrying seven resistance mutations). Following infection of P4 cells, the BV34 mutant, but not viruses expressing the M184V mutation or M41L+T215Y, exhibited a defect in DNA synthesis. Importantly, however, for mutants carrying the M184V mutation or M41L+T215Y mutations, a defect could be detected by using target cells in which dATP pools had been reduced by pretreatment with hydroxyurea. Based on these observations, we developed a recombinant-virus assay to assess the effects of hydroxyurea pretreatment on infectivity of viruses carrying plasma-derived RT sequences from patients with nucleoside resistance. Using this assay, we found that many, but not all, viruses carrying RT resistance mutations display an increased sensitivity to hydroxyurea, suggesting that the impact of RT resistance mutations on viral replication may be more profound in cell populations characterized by smaller dNTP pools.
Does oral contraceptive use affect maximum force production in women?
Authors: Elliott K J , Cable N T , Reilly T
Published: December 2004

Objective:To examine the effects of oral contraceptive use on maximum force production in young women.

Methods:In the study, 21 female subjects (14 pill users and seven eumenorrheic controls) took part. All pill using subjects had been taking a combined, monophasic oral contraceptive pill for at least 6 months. Maximum dynamic and isometric leg strength, maximum isometric strength of the first dorsal interosseus (FDI) muscle, and plasma concentrations of oestradiol and progesterone were measured on days 7 and 14 of pill consumption and day 5 of pill withdrawal. The eumenorrheic group was tested (FDI strength and hormone concentrations) on days 2 and 21 of the menstrual cycle.

Results:There were no significant changes in the concentration of endogenous oestradiol or progesterone or any measure of muscle strength between pill phases (p<0.05). The pill group did not significantly differ from the eumenorrheic group (p<0.05), despite a significant increase in the concentration of progesterone and oestradiol on day 21 of the menstrual cycle compared with day 2 of the menstrual cycle and pill consumption and withdrawal (p<0.05).

Conclusions:These data suggest that oral contraceptive use does not significantly affect muscle strength. Moreover, oral contraceptive users were not stronger or weaker than their eumenorrheic counterparts.
Molecular characterization ofFusariumhead blight resistance in Wangshuibai with simple sequence repeat and amplified fragment length polymorphism markers
Authors: Zhou Wenchun , Kolb Frederic L , Yu Jianbin , Bai Guihua , Boze Larry K , Domier Leslie L
Published: December 2004

Molecular mapping of Fusarium head blight (FHB) resistance quantitative trait loci (QTL) and marker-assisted selection of these QTL will aid in the development of resistant cultivars. Most reported FHB resistance QTL are from 'Sumai 3' and its derivatives. 'Wangshuibai' is a FHB-resistant landrace that originated from China and is not known to be related to 'Sumai 3'. A mapping population of 139 F5:6recombinant inbred lines was developed from a cross of 'Wangshuibai' and 'Wheaton'. This population was developed to map the FHB-resistant QTL in 'Wangshuibai' and was evaluated twice for Type II FHB resistance. A total of 1196 simple sequence repeat and amplified fragment length polymorphism markers were screened on this population, and four FHB resistance QTL were detected. A major QTL near the end of 3BS explained 37.3% of the phenotypic variation. Another QTL on 3BS, located close to the centromere, explained 7.4% of the phenotypic variation. Two additional QTL on 7AL and 1BL explained 9.8% and 11.9% of the phenotypic variation, respectively. The simple sequence repeat and amplified fragment length polymorphism markers closely linked to these QTL may be useful for stacking QTL from 'Wangshuibai' and other sources to develop cultivars with transgressive FHB resistance.Key words: head scab, marker-assisted selection, molecular mapping, Triticum aestivum L., wheat.