bluuebunny/crossref_metadata_2025 huggingface dataset:
REHABILITATION AND RELEASE OF MARINE MAMMALS IN THE UNITED STATES: RISKS AND BENEFITS
Authors: Moore Michael , Early Greg , Touhey Kathleen , Barco Susan , Gulland Frances , Wells Randall
Published: September 2007

Abstract

Rehabilitation of stranded marine mammals elicits polarized attitudes: initially done alongside display collections, but release of rehabilitated animals has become more common. Justifications include animal welfare, management of beach use conflict, research, conservation, and public education. Rehabilitation cost and risks have been identified that vary in degree supported by data rather than perception. These include conflict with fisheries for resources, ignorance of recipient population ecology, poor understanding of long‐term survival, support of the genetically not‐so‐fit, introduction of novel or antibiotic‐resistant pathogens, harm to human health, and cost. Thus facilities must balance their welfare appeal against public education, habitat restoration, human impact reduction, and other conservation activities. Benefits to rehabilitating marine mammals are the opportunity to support the welfare of disabled animals and to publish good science and so advance our understanding of wild populations. In specific cases, the status of a population may make conservation the main reason for rehabilitation. These three reasons for rehabilitation lead to contrasting, and sometimes conflicting, management needs. We therefore outline a decision tree for rehabilitation managers using criteria for each management decision, based on welfare, logistics, conservation, research, and funding to define limits on the number of animals released to the wild.
Evoked potential audiometry of 13 Pacific bottlenose dolphins (Tursiops truncatus gilli)
Authors: Houser Dorian S. , Gomez‐Rubio Alex , Finneran James J.
Published: September 2007

Abstract

Evoked potential audiograms were measured in 13 Pacific bottlenose dolphins (Tursiops truncatus gilli) to determine the variability in hearing sensitivity and range of hearing. The auditory evoked potential system used a transducer embedded in a suction cup to deliver sinusoidal amplitude modulated tones to each dolphin through the pan region of the lower right jaw. Evoked potentials were recorded noninvasively using surface electrodes, and hearing thresholds were estimated by tracking the amplitude of the envelope following response, an evoked potential that is phase‐locked to the stimulus modulation rate. Frequencies tested ranged from 10 to 180 kHz in each animal. Variability in the range of hearing and age‐related reductions in hearing sensitivity and range of hearing were consistent with those observed in Atlantic bottlenose dolphins. Comparison of audiograms to a captive population of Atlantic bottlenose dolphins demonstrated that the Pacific bottlenose dolphins tested in this study had significantly lower thresholds at frequencies of 40 and 60–115 kHz. Differences in thresholds between the groups are unlikely to be due to methodological factors.
Microbial Degradation of Phosmet on Blueberry Fruit and in Aqueous Systems by Indigenous Bacterial Flora on Lowbush Blueberries (Vaccinium angustifolium)
Authors: Crowe K.M. , Bushway A.A. , Bushway R.J. , Davis‐Dentici K.
Published: September 2007

ABSTRACT:  Phosmet‐adapted bacteria isolated from lowbush blueberries (Vaccinium angustifolium) were evaluated for their ability to degrade phosmet on blueberry fruit and in minimal salt solutions. Microbial metabolism of phosmet by isolates of Enterobacter agglomerans and Pseudomonas fluorescens resulted in significant reductions (P < 0.05; 33.8%) in phosmet residues on blueberry fruit. Degradation was accompanied by microbial proliferation of phosmet‐adapted bacteria. Preferential utilization of phosmet as a carbon source was investigated in minimal salt solutions inoculated with either E. agglomerans or P. fluorescens and supplemented with phosmet or phosmet and glucose. Microbial degradation concurrent with the proliferation of P. fluorescens was similar in both liquid systems, indicative of preferential utilization of phosmet as an energy substrate. E. agglomerans exhibited the ability to degrade phosmet as a carbon source, yet in the presence of added glucose, phosmet degradation occurred within the 1st 24 h only followed by total population mortality resulting in no appreciable degradation. Characteristic utilization of glucose by this isolate suggests a possible switch in carbon substrate utilization away from phosmet, which resulted in toxicity from the remaining phosmet. Overall, microbial metabolism of phosmet as an energy source resulted in significant degradation of residues on blueberries and in minimal salt solutions. Thus, the role of adapted strains of E. agglomerans and P. fluorescens in degrading phosmet on blueberries represents an extensive plant–microorganism relationship, which is essential to determination of phosmet persistence under pre‐ and postharvest conditions.
Biotransformation of Isoflavone Glycosides by Bifidobacterium animalis in Soymilk Supplemented with Skim Milk Powder
Authors: Pham T.T. , Shah N.P.
Published: September 2007

ABSTRACT:  Two probiotic strains, Bifidobacterium animalis A and B, were used for the biotransformation of isoflavone glycosides in soymilk prepared from soy protein isolate (SPI) supplemented with skim milk powder (SMP) (SSMP). Unsupplemented soymilk (USM) and reconstituted skim milk powder (RSMP) were used as controls. The numbers of viable microorganisms in these products were enumerated. Lactose and isoflavone contents were quantified using high‐performance liquid chromatography (HPLC). Our results showed that there was significantly higher biotransformation of isoflavone glycosides to aglycones in SSMP than that in USM. The levels of biotransformation were 83.96% and 85.43% for B. animalis A and B, respectively, compared to 74.30% and 72.82% for the USM. In addition, lactose utilization by both strains in SSMP was also higher than that in RSMP. At 24 h, 21.16 mg/mL of lactose was utilized in SSMP by B. animalis A compared with that of 16.88 mg/mL in RSMP. Consequently, the pH of SSMP was lower (3.80) than RSMP (4.00). However, the number of viable bacteria in SSMP was slightly lower than that in RSMP but significantly higher than that in USM. It appears that SMP enhanced the biotransformation of isoflavone glycosides to aglycones and SPI increased the lactose utilization by B. animalis A and B.
Nanostructural Characterization of Catfish Skin Gelatin Using Atomic Force Microscopy
Authors: Yang Hongshun , Wang Yifen , Regenstein Joe M. , Rouse David B.
Published: September 2007

ABSTRACT:  To determine the nanostructure of gelatin from catfish (Ictalurus punctatus) skin, atomic force microscopy (AFM) was used to study gelatin aggregates. The gelatin was extracted at an optimized acid concentration after alkaline processing. First, the AFM imaging parameters were optimized to obtain high‐quality images. Then height mode with a 2‐dimensional plane, 3‐dimensional topographical images, and error signal mode images, which removed slow variations in surface topography but highlighted the edges of sample features, were used to analyze the structure of particles. The results describe fish gelatin at a nanoscale level for the first time and are compared with AFM images of mammalian gelatins. Both annular pores with diameters averaging 118 nm and spherical aggregates with an average diameter of 267 nm were seen in the AFM images of fish gelatin. From the AFM images, we propose that the structures formed were determined by whether the solution penetrated into the gelatin molecules evenly or not during hydrolysis. A scheme for the formation of annular pores and spherical aggregates is proposed.
Effect of Pulp Reduction and Pasteurization on the Release of Aroma Compounds in Industrial Orange Juice
Authors: Berlinet C. , Guichard E. , Fournier N. , Ducruet V.
Published: September 2007

ABSTRACT:  Release of aroma compounds in orange juice according to pulp content and pasteurization was performed by headspace‐solid phase microextraction (HS‐SPME), HS‐SPME‐GC‐olfactometry, and by the determination of partition coefficients of aroma compounds between the juice and the headspace. Orange juices with 12% and 6% pulp contents were collected from a processing line before and after pasteurization. HS‐SPME revealed that the 6% pulp juice was the most affected by pasteurization, with an increase in the release of several aroma compounds that are generated by heat treatment (that is, α‐ and β‐terpinéol) and a decrease in the release of compounds sensitive to pasteurization (that is, neral and geranial). Principal component analysis of olfactometric data allowed discriminating fresh and pasteurized juices, regardless of the pulp content. The determination of the gas/liquid partition coefficients by the phase ratio variation method was possible for 7 aroma compounds. For the most hydrophobic ones, the release of aroma compounds in fresh juices was higher in the 6% pulp juice than in the 12% pulp juice. However, in pasteurized juices, the difference between their partition coefficients was less marked. Potential interactions between cloud proteins and hydrophobic aroma compounds may explain this phenomenon.
Does tumour necrosis factor‐α inhibitor infliximab induce histological resolution of pulmonary sarcoid granulomas?
Authors: Milman Nils , Andersen Claus B. , Baslund Bo , Loft Annika , Iversen Martin
Published: September 2007

Background:  Sarcoid granuloma formation involves the orchestration of cytokines and chemokines, which modulate the host's immune response to the antigen stimulus. The release of cytokines enhances expression of the pro‐inflammatory cytokine tumour necrosis factor‐α (TNF), which plays a crucial role in the formation of sarcoid granuloma, being released from T‐lymphocytes and alveolar macrophages.

Objective:  The aim of this study was to evaluate the effect of infliximab in a case of pulmonary sarcoidosis using a histological approach.

Materials and Methods:  A 44‐year‐old man with biopsy verified chronic pulmonary sarcoidosis being resistant to treatment with corticosteroids and cell cycle inhibitors. Persisting disease activity was confirmed by declining lung function tests and a positive fluorine‐18‐fluorodeoxyglucose–positron emission tomography scan. The patient was treated with a single course of infliximab 3‐mg/kg body weight; 11 days later, a single lung transplantation was performed. Immunohistological staining with the macrophage marker CD68 was performed on lung tissue and mediastinal lymph node tissue from both the initial diagnostic evaluation (prior to infliximab) as well as from the explanted lung (after infliximab).

Results:  Biopsy specimens from lung and mediastinal lymph nodes prior to infliximab demonstrated sarcoid granulomas, and staining with CD68 showed dense infiltration by macrophages (epithelioid cells) in the central part of the granulomas. In contrast, biopsies from the explanted lung after infliximab demonstrated acellular sarcoid granulomas with central amorphous masses, and staining with CD68 showed complete absence of macrophages.

Conclusions:  In this patient, the TNF inhibitor infliximab appeared to induce resolution of sarcoid granulomas starting with disappearance of macrophages probably caused by cell lysis or apoptosis.

Please cite this paper as: Milman N, Andersen CB, Baslund B, Loft A and Iversen M. Does tumour necrosis factor‐α inhibitor infliximab induce histological resolution of pulmonary sarcoid granulomas? The Clinical Respiratory Journal 2007; 1:106–113.
Correlation between parametric imaging using contrast ultrasound and the histological differentiation of hepatocellular carcinoma
Authors: Sugimoto Katsutoshi , Moriyasu Fuminori , Kamiyama Naohisa , Yamada Masahiko , Iijima Hiroko
Published: September 2007

Aim:  To determine whether parametric imaging correlates with the degree of histological differentiation of hepatocellular carcinoma (HCC).

Methods:  The samples comprised 49 nodules diagnosed histologically as HCC: 19 well differentiated (w‐HCC), 22 moderately differentiated (m‐HCC), and eight poorly differentiated (p‐HCC). The ultrasound (US) equipment used was SSA‐770 A (Toshiba Medical Systems, Otawara, Japan) and the contrast agent was SonoVue (Bracco, Milan, Italy). After 1.5 mL of SonoVue was injected intravenously and staining of the tumors and parenchyma was confirmed, microbubbles in the scanned volume were eliminated using high mechanical index (MI) scanning frames. The “arrival time (TA) images,” reflecting β‐values, were displayed with color codes at the phase after reperfusion. Images at the phase when the staining reached a plateau (90–180 s) were used as “A images,” reflecting A values. These images were compared between each histological grade of differentiation.

Results:  Analysis of TA images indicated that β‐values in m‐HCC were higher than those in the adjacent non‐tumor parenchyma in all 22 samples and also were significantly higher than in the other HCCs (P < 0.001 for w‐HCC; P < 0.05 for p‐HCC). Furthermore, β‐values in p‐HCC samples had significantly larger variations in terms of time and space than in the other HCCs (P < 0.001 for w‐HCC; P < 0.01 for m‐HCC). Analysis of A images indicated that the A value for w‐HCC was significantly higher than those for either m‐HCC or p‐HCC (P < 0.001).

Conclusion:  Both TA and A images were useful for diagnosing the histological differentiation of HCC.
Induction of Immune Responses in Mice after Intragastric Administration of
Lactobacillus casei
Producing Porcine Parvovirus VP2 Protein
Authors: Xu Yigang , Li Yijing
Published: September 2007

Lactobacillus casei
ATCC 393 was selected as an antigen delivery vehicle for mucosal immunization against porcine parvovirus (PPV) infection. A 64-kDa fragment of PPV major protective antigen VP2 protein was used as the parvovirus antigen model. A recombinant
Lactobacillus
expressing VP2 protein was constructed with plasmid pPG611.1, where expression and localization of the VP2 protein from recombinant Lc393-rPPV-VP2 was detected via sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western blotting, and immunofluorescence. Both local mucosal and systemic immune responses against PPV were induced in BALB/c mice immunized orally with the recombinant
Lactobacillus
expressing VP2 protein. The induced antibodies demonstrated neutralizing effects on PPV infection. These data indicated that the use of recombinant lactobacilli could be a valuable strategy for future vaccine development of PPV.
6-Aminohexanoate Oligomer Hydrolases from the Alkalophilic Bacteria
Agromyces
sp. Strain KY5R and
Kocuria
sp. Strain KY2
Authors: Yasuhira Kengo , Tanaka Yasuhito , Shibata Hiroshi , Kawashima Yasuyuki , Ohara Akira , Kato Dai-ichiro , Takeo Masahiro , Negoro Seiji
Published: September 2007

Alkalophilic, nylon oligomer-degrading strains,
Agromyces
sp. and
Kocuria
sp., were isolated from the wastewater of a nylon-6 factory and from activated sludge from a sewage disposal plant. The 6-aminohexanoate oligomer hydrolases (NylC) from the alkalophilic strains had 95.8 to 98.6% similarity to the enzyme in neutrophilic
Arthrobacter
sp. but had superior thermostability, activity under alkaline conditions, and affinity for nylon-related substrates, which would be advantageous for biotechnological applications.
Stenoxybacter acetivorans
gen. nov., sp. nov., an Acetate-Oxidizing Obligate Microaerophile among Diverse O
2
-Consuming Bacteria from Termite Guts
Authors: Wertz John T. , Breznak John A.
Published: September 2007

In termite hindguts, fermentative production of acetate—a major carbon and energy source for the insect—depends on efficient removal of inwardly diffusing oxygen by microbes residing on and near the hindgut wall. However, little is known about the identity of these organisms or about the substrate(s) used to support their respiratory activity. A cultivation-based approach was used to isolate O
2
-consuming organisms from hindguts of
Reticulitermes flavipes
. A consistently greater (albeit not statistically significant) number of colonies developed under hypoxia (2% [vol/vol] O
2
) than under air, and the increase coincided with the appearance of morphologically distinct colonies of a novel, rod-shaped, obligately microaerophilic β-proteobacterium that was <95% similar (based on the 16S rRNA gene sequence) to its closest known relative (
Eikenella corrodens
). Nearly identical organisms (and/or their 16S rRNA genes) were obtained from geographically separated and genetically distinct populations of
Reticulitermes
. PCR-based procedures implied that the novel isolates were autochthonous to the hindgut of
R. flavipes
and comprised ca. 2 to 7% of the hindgut prokaryote community. Representative strain TAM-DN1 utilized acetate and a limited range of other organic and amino acids as energy sources and possessed catalase and superoxide dismutase. On solid medium, the optimal O
2
concentration for growth was about 2%, and no growth occurred with O
2
concentrations above 4% or under anoxia. However, cells in liquid medium could grow with higher O
2
concentrations (up to 16%), but only after proportionately extended lag phases. The genetic and physiological distinctiveness of TAM-DN1 and related strains supports their recognition as a new genus and species, for which the name
Stenoxybacter acetivorans
gen. nov., sp. nov. is proposed.
Phylogenetic Ecology of the Freshwater
Actinobacteria
acI Lineage
Authors: Newton Ryan J. , Jones Stuart E. , Helmus Matthew R. , McMahon Katherine D.
Published: September 2007

The acI lineage of freshwater
Actinobacteria
is a cosmopolitan and often numerically dominant member of lake bacterial communities. We conducted a survey of acI 16S rRNA genes and 16S-23S rRNA internal transcribed spacer regions from 18 Wisconsin lakes and used standard nonphylogenetic and phylogenetic statistical approaches to investigate the factors that determine acI community composition at the local scale (within lakes) and at the regional scale (across lakes). Phylogenetic reconstruction of 434 acI 16S rRNA genes revealed a well-defined and highly resolved phylogeny. Eleven previously unrecognized monophyletic clades, each with ≥97.9% within-clade 16S rRNA gene sequence identity, were identified. Clade community similarity positively correlated with lake environmental similarity but not with geographic distance, implying that the lakes represent a single biotic region containing environmental filters for communities that have similar compositions. Phylogenetically disparate clades within the acI lineage were most abundant at the regional scale, and local communities were comprised of more closely related clades. Lake pH was a strong predictor of the community composition, but only when lakes with a pH below 6 were included in the data set. In the remaining lakes (pH above 6) biogeographic patterns in the landscape were instead a predictor of the observed acI community structure. The nonrandom distribution of the newly defined acI clades suggests potential ecophysiological differences between the clades, with acI clades AI, BII, and BIII preferring acidic lakes and acI clades AII, AVI, and BI preferring more alkaline lakes.
Detection and Visualization of an Exopolysaccharide Produced byXylella fastidiosaIn Vitro and In Planta
Authors: Roper M. Caroline , Greve L. Carl , Labavitch John M. , Kirkpatrick Bruce C.
Published: September 2007

Many phytopathogenic bacteria, such asRalstonia solanacearum,Pantoea stewartii, andXanthomonas campestris, produce exopolysaccharides (EPSs) that aid in virulence, colonization, and survival. EPS can also contribute to host xylem vessel blockage. The genome ofXylella fastidiosa, the causal agent of Pierce's disease (PD) of grapevine, contains an operon that is strikingly similar to theX. campestris gumoperon, which is responsible for the production of xanthan gum. Based on this information, it has been hypothesized thatX. fastidiosais capable of producing an EPS similar in structure and composition to xanthan gum but lacking the terminal mannose residue. In this study, we raised polyclonal antibodies against a modified xanthan gum polymer similar to the predictedX. fastidiosaEPS polymer. We used enzyme-linked immunosorbent assay to quantify production of EPS fromX. fastidiosacells grown in vitro and immunolocalization microscopy to examine the distribution ofX. fastidiosaEPS in biofilms formed in vitro and in planta and assessed the contribution ofX. fastidiosaEPS to the vascular occlusions seen in PD-infected grapevines.
Methanobrevibacter ruminantium
as an Indicator of Domesticated-Ruminant Fecal Pollution in Surface Waters
Authors: Ufnar Jennifer A. , Wang Shiao Y. , Ufnar David F. , Ellender R. D.
Published: September 2007

A PCR-based assay (Mrnif) targeting the
nifH
gene of
Methanobrevibacter ruminantium
was developed to detect fecal pollution from domesticated ruminants in environmental water samples. The assay produced the expected amplification product only when the reaction mixture contained DNA extracted from
M. ruminantium
culture, bovine (80%), sheep (100%), and goat (75%) feces, and water samples from a bovine waste lagoon (100%) and a creek contaminated with bovine lagoon waste (100%). The assay appears to be specific and sensitive and can distinguish between domesticated- and nondomesticated-ruminant fecal pollution in environmental samples.
Stenotrophomonas maltophiliaSeITE02, a New Bacterial Strain Suitable for Bioremediation of Selenite-Contaminated Environmental Matrices
Authors: Antonioli Paolo , Lampis Silvia , Chesini Irene , Vallini Giovanni , Rinalducci Sara , Zolla Lello , Righetti Pier Giorgio
Published: September 2007

Biochemical and proteomic tools have been utilized for investigating the mechanism of action of a newStenotrophomonas maltophiliastrain (SeITE02), a gammaproteobacterium capable of resistance to high concentrations of selenite [SeO32−, Se(IV)], reducing it to nontoxic elemental selenium under aerobic conditions; this strain was previously isolated from a selenite-contaminated mining soil. Biochemical analysis demonstrated that (i) nitrite reductase does not seem to take part in the process of selenite reduction by the bacterial strain SeITE02, although its involvement in this process had been hypothesized in other cases; (ii) nitrite strongly interferes with selenite removal when the two oxyanions (NO2−and SeO32−) are simultaneously present, suggesting that the two reduction/detoxification pathways share a common enzymatic step, probably at the level of cellular transport; (iii) in vitro, selenite reduction does not take place in the membrane or periplasmic fractions but only in the cytoplasm, where maximum activity is exhibited at pH 6.0 in the presence of NADPH; and (iv) glutathione is involved in the selenite reduction mechanism, since inhibition of its synthesis leads to a considerable delay in the onset of reduction. As far as the proteomic findings are concerned, the evidence was reached that 0.2 mM selenite and 16 mM nitrite, when added to the culture medium, caused a significant modulation (ca. 10%, i.e., 96 and 85 protein zones, respectively) of the total proteins visualized in the respective two-dimensional maps. These spots were identified by mass spectrometry analysis and were found to belong to the following functional classes: nucleotide synthesis and metabolism, damaged-protein catabolism, protein and amino acid metabolism, and carbohydrate metabolism along with DNA-related proteins and proteins involved in cell division, oxidative stress, and cell wall synthesis.
Application of DNA Bar Codes for Screening of Industrially Important Fungi: the Haplotype of
Trichoderma harzianum
Sensu Stricto Indicates Superior Chitinase Formation
Authors: Nagy Viviana , Seidl Verena , Szakacs George , Komoń-Zelazowska Monika , Kubicek Christian P. , Druzhinina Irina S.
Published: September 2007

Selection of suitable strains for biotechnological purposes is frequently a random process supported by high-throughput methods. Using chitinase production by
Hypocrea lixii/Trichoderma harzianum
as a model, we tested whether fungal strains with superior enzyme formation may be diagnosed by DNA bar codes. We analyzed sequences of two phylogenetic marker loci, internal transcribed spacer 1 (ITS1) and ITS2 of the rRNA-encoding gene cluster and the large intron of the elongation factor 1-alpha gene,
tef1
, from 50 isolates of
H. lixii/T. harzianum
, which were also tested to determine their ability to produce chitinases in solid-state fermentation (SSF). Statistically supported superior chitinase production was obtained for strains carrying one of the observed ITS1 and ITS2 and
tef1
alleles corresponding to an allele of
T. harzianum
type strain CBS 226.95. A
tef1
-based DNA bar code tool,
Tricho
CHIT, for rapid identification of these strains was developed. The geographic origin of the strains was irrelevant for chitinase production. The improved chitinase production by strains containing this haplotype was not due to better growth on
N
-acetyl-β-
d
-glucosamine or glucosamine. Isoenzyme electrophoresis showed that neither the isoenzyme profile of
N
-acetyl-β-glucosaminidases or the endochitinases nor the intensity of staining of individual chitinase bands correlated with total chitinase in the culture filtrate. The superior chitinase producers did not exhibit similarly increased cellulase formation. Biolog Phenotype MicroArray analysis identified lack of
N
-acetyl-β-
d
-mannosamine utilization as a specific trait of strains with the chitinase-overproducing haplotype. This observation was used to develop a plate screening assay for rapid microbiological identification of the strains. The data illustrate that desired industrial properties may be an attribute of certain populations within a species, and screening procedures should thus include a balanced mixture of all genotypes of a given species.
Multiple Introductions of the Old World Begomovirus
Tomato yellow leaf curl virus
into the New World
Authors: Duffy Siobain , Holmes Edward C.
Published: September 2007

A phylogenetic analysis of three genomic regions revealed that
Tomato yellow leaf curl virus
(TYLCV) from western North America is distinct from TYLCV isolated in eastern North America and the Caribbean. This analysis supports a second introduction of this Old World begomovirus into the New World, most likely from Asia.
Autecology of an Arsenite Chemolithotroph: Sulfide Constraints on Function and Distribution in a Geothermal Spring
Authors: D'Imperio Seth , Lehr Corinne R. , Breary Michele , McDermott Timothy R.
Published: September 2007

Previous studies in an acid-sulfate-chloride spring in Yellowstone National Park found that microbial arsenite [As(III)] oxidation is absent in regions of the spring outflow channel where H
2
S exceeds ∼5 μM and served as a backdrop for continued efforts in the present study. Ex situ assays with microbial mat samples demonstrated immediate As(III) oxidation activity when H
2
S was absent or at low concentrations, suggesting the presence of As(III) oxidase enzymes that could be reactivated if H
2
S is removed. Cultivation experiments initiated with mat samples taken from along the H
2
S gradient in the outflow channel resulted in the isolation of an As(III)-oxidizing chemolithotroph from the low-H
2
S region of the gradient. The isolate was phylogenetically related to
Acidicaldus
and was characterized in vitro for spring-relevant properties, which were then compared to its distribution pattern in the spring as determined by denaturing gradient gel electrophoresis and quantitative PCR. While neither temperature nor oxygen requirements appeared to be related to the occurrence of this organism within the outflow channel, H
2
S concentration appeared to be an important constraint. This was verified by in vitro pure-culture modeling and kinetic experiments, which suggested that H
2
S inhibition of As(III) oxidation is uncompetitive in nature. In summary, the studies reported herein illustrate that H
2
S is a potent inhibitor of As(III) oxidation and will influence the niche opportunities and population distribution of As(III) chemolithotrophs.
Mutated Cadherin Alleles from a Field Population of
Helicoverpa armigera
Confer Resistance to
Bacillus thuringiensis
Toxin Cry1Ac
Authors: Yang Yajun , Chen Haiyan , Wu Yidong , Yang Yihua , Wu Shuwen
Published: September 2007

The cotton bollworm
Helicoverpa armigera
is the major insect pest targeted by cotton genetically engineered to produce the
Bacillus thuringiensis
toxin (transgenic Bt cotton) in the Old World. The evolution of this pest's resistance to
B. thuringiensis
toxins is the main threat to the long-term effectiveness of transgenic Bt cotton. A deletion mutation allele (
r

1

) of a cadherin gene (
Ha_BtR
) was previously identified as genetically linked with Cry1Ac resistance in a laboratory-selected strain of
H. armigera
. Using a biphasic screen strategy, we successfully trapped two new cadherin alleles (
r

2

and
r

3

) associated with Cry1Ac resistance from a field population of
H. armigera
collected from the Yellow River cotton area of China in 2005. The
r

2

and
r

3

alleles, respectively, were created by inserting the long terminal repeat of a retrotransposon (designated
HaRT1
) and the intact
HaRT1
retrotransposon at the same position in exon 8 of
Ha_BtR
, which results in a truncated cadherin containing only two ectodomain repeats in the N terminus of
Ha_BtR
. This is the first time that the
B. thuringiensis
resistance alleles of a target insect of Bt crops have been successfully detected in the open field. This study also demonstrated that bollworm larvae carrying two resistance alleles can complete development on Bt cotton. The cadherin locus should be an important target for intensive DNA-based screening of field populations of
H. armigera
.
Effects of Salivary Gland Hypertrophy Virus on the Reproductive Behavior of the Housefly,
Musca domestica
Authors: Lietze Verena-Ulrike , Geden Christopher J. , Blackburn Patrick , Boucias Drion G.
Published: September 2007

Pathological studies demonstrated that the salivary gland hypertrophy virus of houseflies (MdSGHV) shuts down reproduction in infected females. The mechanism that underlay the disruption of reproduction functioned on several levels. Females infected at the previtellogenic stage did not produce eggs, reflecting a block in the gonadotropic cycle. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analysis of hemolymph samples demonstrated that MdSGHV infection reduced the levels of both the female-specific hexamerin and egg yolk proteins. Furthermore, reverse transcriptase quantitative real-time PCR data demonstrated that infection blocked hexamerin and yolk protein gene transcription. When females were allowed to develop eggs prior to infection (postvitellogenic stage), the outcome of mating attempts depended upon when mating took place. If egg-containing, virus-infected females were mated within 24 h of infection, they copulated and deposited a single batch of fertilized eggs. However, if mating was delayed for a longer period, the egg-containing females refused to copulate with healthy males. Both of these results suggested that a virus-induced signal influenced the central nervous system, shutting down female receptivity and egg production. All experiments demonstrated that MdSGHV-infected males did not display azoospermia and were fertile. Both healthy females mated with infected males, and the resulting F1 progeny were free of salivary gland hypertrophy symptoms, which suggests that the virus is not sexually or vertically transmitted.
Identification of anEntamoeba histolyticaSerine-, Threonine-, and Isoleucine-Rich Protein with Roles in Adhesion and Cytotoxicity
Authors: MacFarlane Ryan C. , Singh Upinder
Published: September 2007

Entamoeba histolyticais a leading cause of parasitic death globally. However, the molecular framework regulating pathogenesis is poorly understood. We have previously used expression profiling to identifyEntamoebagenes whose expressions were strictly associated with virulent strains (R. C. MacFarlane and U. Singh, Infect. Immun. 74:340-351, 2006). One gene, which we have named EhSTIRP (Entamoebahistolyticaserine-,threonine-, andisoleucine-richprotein), was exclusively expressed in virulent but not in nonvirulentEntamoebastrains. EhSTIRP is predicted to be a transmembrane protein and is encoded by a multigene family. In order to characterize its function in amebic biology, we used a double-stranded RNA-based approach and were able to selectively down-regulate expression of this gene family. Upon EhSTIRP down-regulation, we were able to ascribe cytotoxic and adhesive properties to the protein family using lactate dehydrogenase release and Chinese hamster ovary cell adhesion assays. EhSTIRP thus likely represents a novel determinant of virulence inEntamoeba histolytica. This work validates the fact that genes expressed exclusively in virulent strains may represent virulence determinants and highlights the need for further functional analyses of other genes with similar expression profiles.
The Deoxycytidine Pathway for Thymidylate Synthesis in
Escherichia coli
Authors: Weiss Bernard
Published: September 2007

When thymidylate production is diminished by a mutation affecting dCTP deaminase,
Escherichia coli
is known to use an alternate pathway involving deoxycytidine as an intermediate. The pathway requires the gene for any of three nucleoside diphosphate kinases (
ndk
,
pykA
, or
pykF
) and the gene for a 5′-nucleotidase (
yfbR
).
Transcriptome Analysis of the
Vibrio fischeri
LuxR-LuxI Regulon
Authors: Antunes Luis Caetano M. , Schaefer Amy L. , Ferreira Rosana B. R. , Qin Nan , Stevens Ann M. , Ruby Edward G. , Greenberg E. Peter
Published: September 2007

The
Vibrio fischeri
quorum-sensing signal
N
-3-oxohexanoyl-
l
-homoserine lactone (3OC6-HSL) activates expression of the seven-gene luminescence operon. We used microarrays to unveil 18 additional 3OC6-HSL-controlled genes, 3 of which had been identified by other means previously. We show most of these genes are regulated by the 3OC6-HSL-responsive transcriptional regulator LuxR directly. This demonstrates that
V. fischeri
quorum sensing regulates a substantial number of genes other than those involved in light production.
The
Mesorhizobium loti purB
Gene Is Involved in Infection Thread Formation and Nodule Development in
Lotus japonicus
Authors: Okazaki Shin , Hattori Yoshiyuki , Saeki Kazuhiko
Published: September 2007

The
purB
and
purH
mutants of
Mesorhizobium loti
exhibited purine auxotrophy and nodulation deficiency on
Lotus japonicus
. In the presence of adenine, only the
purH
mutant induced nodule formation and the
purB
mutant produced few infection threads, suggesting that 5-aminoimidazole-4-carboxamide ribonucleotide biosynthesis catalyzed by PurB is required for the establishment of symbiosis.
DivL Performs Critical Cell Cycle Functions inCaulobacter crescentusIndependent of Kinase Activity
Authors: Reisinger Sarah J. , Huntwork Sarah , Viollier Patrick H. , Ryan Kathleen R.
Published: September 2007

TheCaulobactercell cycle is regulated by a network of two-component signal transduction proteins. Phosphorylation and stability of the master transcriptional regulator CtrA are controlled by the CckA-ChpT phosphorelay, and CckA activity is modulated by another response regulator, DivK. In a screen to identify suppressors of the cold-sensitivedivK341mutant, we found point mutations in the essential genedivL. DivL is similar to histidine kinases but has a tyrosine instead of a histidine at the conserved phosphorylation site (Y550). Surprisingly, we found that the ATPase domain of DivL is not essential forCaulobacterviability. We show that DivL selectively affects CtrA phosphorylation but not CtrA proteolysis, indicating that DivL acts in a pathway independent of the CckA-ChpT phosphorelay.divLcan be deleted in a strain overproducing the phosphomimetic protein CtrAD51E, but unlike ΔctrAcells expressing CtrAD51E, this strain is profoundly impaired in the control of chromosome replication and cell division. Thus, DivL performs a second function in addition to promoting CtrA phosphorylation. DivL is required for bipolar DivK localization and positively regulates DivK phosphorylation. Our results show that DivL controls two key cell cycle regulators, CtrA and DivK, and that phosphoryl transfer is not DivL's essential cellular activity.
Enterococcal Surface Protein Esp Is Important for Biofilm Formation of
Enterococcus faecium
E1162
Authors: Heikens Esther , Bonten Marc J. M. , Willems Rob J. L.
Published: September 2007

Enterococci have emerged as important nosocomial pathogens with resistance to multiple antibiotics. Adhesion to abiotic materials and biofilm formation on medical devices are considered important virulence properties. A single clonal lineage of
Enterococcus faecium
, complex 17 (CC17), appears to be a successful nosocomial pathogen, and most CC17 isolates harbor the enterococcal surface protein gene,
esp
. In this study, we constructed an
esp
insertion-deletion mutant in a clinical
E. faecium
CC17 isolate. In addition, initial adherence and biofilm assays were performed. Compared to the wild-type strain, the
esp
insertion-deletion mutant no longer produced Esp on the cell surface and had significantly lower initial adherence to polystyrene and significantly less biofilm formation, resulting in levels of biofilm comparable to those of an
esp
-negative isolate. Capacities for initial adherence and biofilm formation were restored in the insertion-deletion mutant by in
trans
complementation with
esp
. These results identify Esp as the first documented determinant in
E. faecium
CC17 with an important role in biofilm formation, which is an essential factor in infection pathogenesis.
Nitric oxide and superoxide generation from endothelial NOS: modulation by HSP90
Authors: Sud Neetu , Sharma Shruti , Wiseman Dean A. , Harmon Cynthia , Kumar Sanjiv , Venema Richard C. , Fineman Jeffrey R. , Black Stephen M.
Published: September 2007

Previously, we have shown that pulmonary arterial endothelial cells (PAECs) isolated from fetal lambs produce significant levels of nitric oxide (NO) but minimal superoxide upon stimulation, whereas PAECs isolated from 4-wk-old lambs produce significant amounts of both NO and superoxide. These data indicated that a certain degree of uncoupling of endothelial NO synthase (eNOS) occurs in PAECs during postnatal development. In this study, we sought to extend these studies by investigating the potential role of heat shock protein 90 (HSP90) in eNOS coupling. Western blot analyses revealed higher HSP90 expression in PAECs isolated from fetal compared with 4-wk-old lambs, whereas the analysis of recombinant human eNOS activation in vitro in the presence of HSP90 indicated that HSP90 significantly augmented NO production while inhibiting superoxide generation from eNOS. To further investigate whether HSP90 could be involved in uncoupling of eNOS in PAECs isolated from 4-wk-old lambs, we utilized an adenovirus to overexpress HSP90. We found that overexpression of HSP90 significantly increased the shear-stimulated association of HSP90 with eNOS and led to significant increases in NO production and reduced NOS-dependent superoxide generation. Conversely, the exposure of PAECs isolated from fetal lambs to the HSP90 inhibitor radicicol led to significant decreases in eNOS-HSP90 interactions, decreased shear-stimulated NO generation, and increased NOS-dependent superoxide production indicative of eNOS uncoupling. Finally, we examined eNOS-HSP90 interactions in our lamb model of pulmonary hypertension associated with increased pulmonary blood flow (shunt). Our data indicate that HSP90-eNOS interactions were decreased in shunt lambs and that this was associated with decreased NO generation and an increase in eNOS-dependent generation of superoxide. Together, our data support a significant role for HSP90 in promoting NO generation and inhibiting superoxide generation by eNOS and indicate that the disruption of this interaction may be involved in the endothelial dysfunction associated with pulmonary hypertension.
Unfractionated heparin reduces the elasticity of sputum from patients with cystic fibrosis
Authors: Broughton-Head Victoria J. , Shur Jagdeep , Carroll Mary P. , Smith James R. , Shute Janis K.
Published: September 2007

Mucus obstruction of the airway in patients with cystic fibrosis (CF) reduces lung function, invites infection, and limits delivery of inhaled drugs including gene therapy vectors to target cells. Not all patients respond to presently available mucolytics, and new approaches are needed. Our objectives were to investigate the in vitro effects of unfractionated heparin (UFH) on the morphology and rheology of sputum and the effect of UFH on diffusion of 200-nm nanospheres through sputum from adult CF patients. Confocal laser scanning microscopy was used to image fluorescently stained actin and DNA components of CF sputum, and atomic force microscopy was used to image isolated DNA networks. The viscoelasticity of CF sputum was measured using dynamic oscillatory rheometry. Nanosphere diffusion was measured through CF sputum using a Boyden chamber-based assay. Actin-DNA bundles in CF sputum were disaggregated by UFH at concentrations of 0.1–10 mg/ml, and UFH enhanced the endonuclease activity in sputum from patients on dornase alfa therapy. UFH significantly reduced the elasticity and yield stress, but not the viscosity, of CF sputum from patients not receiving dornase alfa therapy. Heparin dose-dependently significantly increased the diffusion of nanospheres through CF sputum from patients not on dornase alfa therapy from 10.5 ± 2.5% at baseline to 36.9 ± 4.4% at 10 mg/ml but was more potent, with maximal effect at 0.1 mg/ml, in patients who were on dornase alfa therapy. Thus the mucoactive properties of UFH indicate its potential as a new therapeutic approach in patients with cystic fibrosis.
Development of plasmacytoid dendritic cells in bone marrow stromal cell niches requires CXCL12-CXCR4 chemokine signaling
Authors: Kohara Hiroshi , Omatsu Yoshiki , Sugiyama Tatsuki , Noda Mamiko , Fujii Nobutaka , Nagasawa Takashi
Published: September 2007

Plasmacytoid dendritic cells (pDCs), also known as type I interferon (IFN)–producingcells, are thought to play central roles in antiviral immunity and the pathogenesis of some autoimmune diseases. pDCs are produced from hematopoietic stem cells in bone marrow. However, the environmental regulation of the development of pDCs is not fully understood. Here, we show that the numbers of pDCs and their earliest progenitors are severely reduced in the absence of CXCR4, the primary physiologic receptor for CXC chemokine ligand 12 (CXCL12), also known as stromal cell–derived factor-1 (SDF-1) in vivo. In vitro, CXCL12 induces a significant increase in pDC numbers generated from primitive hematopoietic cells, and pDCs and their progenitors migrate to CXCL12. In addition, most pDCs are in contact with CXCL12-abundant reticular (CAR) cells in the intersinal space of bone marrow, although many primitive hematopoietic cells adjoin CAR cells surrounding sinusoidal endothelial cells or residing near the bone surface. Thus we identified CXCL12 as a key regulator of pDC development produced by cellular niches, providing new targets for pDC therapeutic control.
Involvement of intraplaque hemorrhage in atherothrombosis evolution via neutrophil protease enrichment
Authors: Leclercq Anne , Houard Xavier , Philippe Monique , Ollivier Véronique , Sebbag Uriel , Meilhac Olivier , Michel Jean-Baptiste
Published: September 2007

The pathological remodeling of the arterial wall in atherosclerosis involves protease activities, which play a major role in complications via plaque rupture. Circulating leukocytes and particularly neutrophils have been shown to be an independent predictor of recurrent ischemic events. However, neutrophils are poorly documented within atherosclerotic plaques. We hypothesized that intraplaque hemorrhage could convey neutrophils into the lesion, spreading into the necrotic core, thus participating in its protease enrichment. One hundred human carotid endarterectomy specimens were dissected into culprit-stenosing plaques (CPs) and adjacent noncomplicated plaques. Half of CPs exhibited hemorrhage, which was confirmed by the release of hemoglobin. Pro- and active forms of matrix metalloproteinase-9 (MMP-9) were increased in media conditioned by hemorrhagic plaques. Higher levels of lipocalin [neutrophil gelatinase-associated lipocalin (NGAL)]/MMP-9 complexes, specifically released by neutrophils, were also found in conditioned media from plaques with hemorrhage. Immunohistochemical analysis of the corresponding carotid samples showed that neutrophil markers such as elastase, NGAL/MMP-9, CD66b, and proteinase 3 colocalized with blood constituents (i.e., hemoglobin, plasminogen). All markers of neutrophil degranulation were positively correlated in CP-conditioned media (α1-antitrypsin/elastase complexes, myeloperoxidase, and α-defensins), and higher levels came from CPs containing intraplaque hemorrhages. Addition of an elastase inhibitor at the time of incubation led to a decrease in the proMMP-9 activation in CPs, suggesting cross-talk between proteases released by neutrophils. Finally, we found that neovessels observed at the interface between cap and core exhibit an activated endothelium, which may favor leukocyte diapedesis. Our study thus provides evidence for the involvement of neutrophils in plaque vulnerability.
Prediction of human pharmacokinetics – evaluation of methods for prediction of volume of distribution
Authors: Fagerholm Urban
Published: September 2007

The aim was to evaluate and review methods for prediction of the steady-state volume of distribution (VD,ss) of xenobiotics in man. For allometry, ˜30–40% of predictions are classified as incorrect, humans and animals belong to different VD,ss categories for ˜30% of the compounds, maximum prediction errors are large (>10-fold), the b-exponent ranges between −0.2 and 2.2 (averaging ˜0.8–0.9), and >2-fold prediction errors are found for 35% of the substances. The performance is consistent with species differences of binding in and outside the vasculature. The largest errors could potentially lead to very poor prediction of exposure profile and failure in clinical studies. A re-evaluation of allometric scaling of unbound tissue volume of distribution demonstrates that this method is less accurate (27% of predictions >2-fold errors) than a previous evaluation demonstrated. By adding molecular descriptor information, predictions based on animal VD,ss data can be improved. Improved predictions (˜1/10 of allometric errors) can also be obtained by using the relationship between unbound fraction in plasma (fu,pl) and VD,ss for each substance (method suggested by the author). A physiologically-based 4-compartment model (plasma, red blood cells, interstitial fluid and cell volume) together with measured tissue-plasma partitioning coefficients in rats, fu,pl, interstitial-plasma concentration ratio of albumin, organ weight and blood flow data has been successfully applied. Prediction errors for one basic and one neutral drug are only 3–5%. The data obtained with this comparably laboratory-intensive method are limited to these two compounds. A similar approach where predicted tissue partitioning is used, and a computational model, give prediction errors similar to that of allometry. Advantages with these are the suitability for screening and avoidance of animal experiments. The evaluated methods do not account for potential active transport and slow dissociation rates.