bluuebunny/crossref_metadata_2025 huggingface dataset:
Availability of High School Extracurricular Sports Programs and High‐Risk Behaviors
Authors: Cohen Deborah A. , Taylor Stephanie L. , Zonta Michela , Vestal Katherine D. , Schuster Mark A.
Published: January 2007

Background:  The Surgeon General has called for an expansion of school‐based extracurricular sports programs to address the obesity epidemic. However, little is known about the availability of and participation in high school extracurricular sports and how participation in these sports is related to high‐risk behaviors.

Methods:  We surveyed Los Angeles County public high schools in 2002 to determine the number of extracurricular sports programs offered and the percentage of students participating in those programs. We used community data on rates of arrests, births, and sexually transmitted diseases (STDs) among youth to examine associations between risk behaviors and participation in sports programs.

Results:  The average school offered 14 sports programs, and the average participation rate was 39% for boys and 30% for girls. Smaller schools and schools with higher percentages of disadvantaged students offered fewer programs. The average school offering 13 or fewer programs had 14% of its students participating, while the average school offering 16 or more programs had 31% of its students participating in sports. Controlling for area‐level demographics, juvenile arrest rates and teen birth rates, but not STD rates, were lower in areas where schools offered more extracurricular sports.

Conclusions:  Opportunities for participation in high school extracurricular sports are limited. Future studies should test whether increased opportunities will increase physical activity and impact the increasing overweight problem in youths.
Assessment of Health Issues and Concerns of Israeli Seventh Graders During School Physician Examinations: A Pilot Study
Authors: Knishkowy Barry , Amitai Yona , Hardoff Daniel , Levy Yehoshua , Kiro Amnon ,   The Israel School Physicians Study Group
Published: January 2007

Background:  The AMA Guidelines for Adolescent Preventive Services (GAPS) recommends annual medical evaluations during adolescence, emphasizing screening and counseling regarding psychosocial issues. In Israel, seventh graders undergo medical examinations within the school health services, focusing on the detection of physical conditions. We addressed the psychosocial issues of these students by introducing an expanded school physician evaluation.

Methods:  Twelve school physicians performed structured expanded health evaluations for seventh graders in 11 schools. Each student completed a questionnaire (checklist) with 22 health topics “about which s/he may want to receive information.” The physician then carried out a biomedical and psychosocial evaluation, physical examination, and offered counseling to the student.

Results:  Two hundred and seventy‐eight students were examined. The questionnaire required 1‐2 minutes, and the physician’s evaluation 20‐25 minutes. Health behaviors revealed included: currently dieting (28%), no physical activity after school (35%), ever smoked cigarettes (3%), ever smoked a water pipe (9%), used alcoholic beverages (6%), and does not always use front (22%) or rear (55%) seat belt. Nine percent rated their mood as being less than 7 (on a scale from 1 to 10). The leading topics about which the students requested information were height (50%), acne (42%), weight (38%), nutrition/diet (37%), physical activity (35%), and menstrual period (29% of the girls). The physicians counseled the students on an average of 3.6 topics per visit.

Conclusions:  An expanded school physician examination identifies students with psychosocial problems otherwise undetected during standard physical examinations, and provides the opportunity to address their personal concerns.
Redrawing the Map of Europe: Spatial Formation of the EU's Eastern Dimension
Authors: Moisio Sami
Published: January 2007

How to write about the many, diverse, politically contested and often highly contradictory meanings of Eastern Europe in a short text? In this article, I approach Eastern Europe from the perspective of the recent (2004) expansion of the European Union (EU) by introducing two among the many geographical themes that have appeared in research within the past few years. I examine the recent EU expansion first from the constructionist viewpoint by introducing the political geography of the ‘return to Europe’ discourse championed by the drivers of the enlargement. Second, I discuss the possible boundary regimes in the eastern part of the EU. These two phenomena are inescapably interlinked and form what might be called the EU's eastern dimension. Finally, I introduce some themes that merit scholarly attention as the EU is preparing for future expansion.
Detection of Nematodes in Cod (Gadus morhua) Fillets by Imaging Spectroscopy
Authors: Heia Karsten , Sivertsen Agnar H. , Stormo Svein K. , Elvevoll Edel , Wold Jens Petter , Nilsen Heidi
Published: January 2007

ABSTRACT:  A promising method for detection of parasites in whitefish fillets has been developed. By use of imaging spectroscopy it is possible to record both spectral and spatial information from an object. In this work it is shown that by applying a white light transmission setup and imaging spectroscopy to cod (Gadus morhua) fillets, it is possible to make spectral images containing information to differentiate between fish muscle and parasites. The spectral images are analyzed by discriminant partial least square regression as well as image‐filtering techniques. The method identifies parasites on the surface of the fillets as well as embedded parasites. One parasite was detected at 0.8 cm below the fillet surface, which is 2 to 3 mm deeper than what can be found by manual inspection of fish fillets. The method is nonintrusive and should thus be feasible for industrial purposes.
Effects of Rice Harvest Moisture on Kernel Damage and Milled Rice Surface Free Fatty Acid Levels
Authors: Parker Amanda M. , Proctor Andrew , Eason Robert L. , Jain Vishal
Published: January 2007

ABSTRACT:  Surface free fatty acid (FFA) on milled rice is a key factor in determining rice quality and acceptability to the brewing industry. Rice FFA oxidizes, causing off‐flavors and odors to develop, compromising the brewing quality of milled rice. The effect of harvest moisture (13%, 16%, and 20%), harvester type (1688 Case and 9500 John Deere), and rice variety (Cocodrie and Bengal) on harvest damaged rough rice and milled rice surface FFA after drying to 12% moisture and 6 mo rough rice storage was examined. The Case harvester produced more damaged kernels than the John Deere harvester, but this was not reflected in surface FFA development. There were no significant FFA differences in variety or harvester type. Rice harvested at a higher moisture content (20%) produced significantly greater FFA values, with a peak near 0.1%, than rice harvested at lower moisture contents (13% and 16%), which had FFA values near 0.08%. Retention of bran by damaged kernels at high harvest moisture probably was responsible for promoting surface FFA development, but if bran was lost at lower harvest moistures, surface FFA, development was limited. Harvest moisture affected milled rice FFA, although rough rice was dried to 12% immediately after harvesting.
Artificial Neural Network Modeling for Temperature and Moisture Content Prediction in Tomato Slices Undergoing Microwave‐Vacuum Drying
Authors: Poonnoy Poonpat , Tansakul Ampawan , Chinnan Manjeet
Published: January 2007

ABSTRACT:  Inputs for ANN (multihidden‐layer feed‐forward artificial neural network) models were drying time (ti+ 1), initial temperature (T0), moisture content (MC0), microwave power, and vacuum pressure. The outputs were temperature (Ti+ 1) and moisture content (MCi+ 1) at a given ti+ 1. After training the ANN models with experimental data using the Levenberg‐Marquardt algorithm, a two‐hidden‐layer model (25‐25) was determined to be the most appropriate model. The mean relative error (MRE) and mean absolute error (MAE) of this model for Ti+ 1 were 1.53% and 0.77 °C, respectively. In the case of MCi+ 1, the MRE and MAE were 11.48% and 0.04 kgwater/kgdry, respectively. Using temperature (Ti) and moisture content (MCi) values at ti in the input layer significantly reduced the computation errors such that MRE and MAE for Ti+ 1 were 0.35% and 0.18 °C, respectively. In contrast, these error values for MCi+ 1 were 1.78% (MRE) and 0.01 kgwater/kgdry (MAE). These results indicate that ANN models were able to recognize relationships between process parameters and product conditions. The model may provide information regarding microwave power and vacuum pressure to prevent thermal damage and improve drying efficiencies.
Axial Compressor Deterioration Caused by Saltwater Ingestion
Authors: Syverud Elisabet , Brekke Olaf , Bakken Lars E.
Published: January 2007

Gas turbine performance deterioration can be a major economic factor. An example is within offshore installations where a degradation of gas turbine performance can mean a reduction of oil and gas production. This paper describes the test results from a series of accelerated deterioration tests on a General Electric J85-13 jet engine. The axial compressor was deteriorated by spraying atomized droplets of saltwater into the engine intake. The paper presents the overall engine performance deterioration as well as deteriorated stage characteristics. The results of laboratory analysis of the salt deposits are presented, providing insight into the increased surface roughness and the deposit thickness and distribution. The test data show good agreement with published stage characteristics and give valuable information regarding stage-by-stage performance deterioration.
Predicting Transition in Turbomachinery—Part I: A Review and New Model Development
Authors: Praisner T. J. , Clark J. P.
Published: January 2007

Here we report on an effort to include an empirically based transition modeling capability in a Reynolds Averaged Navier-Stokes solver. Well known empirical models for both attached- and separated-flow transition were tested against cascade data and found unsuitable for use in turbomachinery design. Consequently, a program was launched to develop models with sufficient accuracy for use in design. As a first step, accurate prediction of free stream turbulence development was identified as a prerequisite for accurate modeling. Additionally, a demonstrated capability to capture the effects of free stream turbulence on pre-transitional boundary layers became an impetus for the work. A computational fluid dynamics (CFD)-supplemented database of 104 experimental cascade cases was constructed to explore the development of new correlations. Dimensional analyses were performed to guide the work, and appropriate non-dimensional parameters were then extracted from CFD predictions of the laminar boundary layers existing on the airfoil surfaces prior to either transition onset or incipient separation. For attached-flow transition, onset was found to occur at a critical ratio of the boundary-layer diffusion time to a time scale associated with the energy-bearing turbulent eddies. In the case of separated-flow transition, it was found that the length of a separation bubble prior to turbulent reattachment was a simple function of the local momentum thickness at separation and the overall surface length traversed by a fluid element prior to separation. Both the attached- and separated-flow transition models were implemented into the design system as point-like trips.
Comparison of Solar Collection Geometries for Application to Photocatalytic Degradation of Organic Contaminants
Authors: Bandala Erick R. , Estrada Claudio
Published: January 2007

A comparative study between four different solar collectors was carried out using oxalic acid and the pesticide carbaryl as model contaminants. The comparison was performed by means of a figure-of-merit developed for solar driven Advanced Oxidation Technology systems by the International Union of Pure and Applied Chemistry (IUPAC) for standardization purposes. It was found that there is a relationship between the photocatalyst concentration and the overall solar collector performance. Compound parabolic concentrator was the geometry with the highest turnover rate in the photocatalytic process of oxalic acid, followed by the V trough collector, the parabolic concentrator, and, finally, the tubular collector. When a comparative analysis was carried out using the figure of merit (collector area per order, ACO), the parabolic trough concentrator (PTC) showed the highest efficiency (lower ACO values) at low photocatalyst loads. The V trough collector and the compound parabolic collector showed similar ACO values, which decreased as the photocatalyst concentration increased. The tubular collector was the worst in all catalyst concentration ranges, with the higher collection surface by the order of oxalic acid. Photocatalytic degradation of the carbamic pesticide was tested using the same experimental arrangement used for oxalic acid. In this case, the use of the figure-of-merit allowed us to observe the same trend as that displayed for oxalic acid, but with slightly higher ACO values. Results of this work demonstrate that a comparison between different reactor geometries for photocatalytic processes is viable using this figure-of-merit approach and that the generated results can be useful in the standardization of a methodology for solar driven processes comparison and provide important data for the scaling up of the process.
The Effect of Modifying TiO2 on Catechol and Resorcinol Photocatalytic Degradation
Authors: Araña J. , Rodríguez J. M. Doña , Díaz O. González , Melián J. A. Herrera , Peña. J. Pérez
Published: January 2007

The photocatalytic features of TiO2 doped with ferric oxides or mixed with activated carbon (AC-TiO2) are compared with those of the unmodified Degussa P-25 TiO2. These new catalysts show specific structural features that alter catechol and resorcinol photodegradabilities, according to their chemical structures. For instance, we have observed that Fe oxides located on the TiO2 particle surface hamper these dihydroxybenzenes degradation. Likewise, AC-TiO2 catalysts have shown improved catechol photodegradability with respect to that of TiO2, while that of resorcinol is not altered. These studies show that catechol and resorcinol adsorption patterns are different, i.e., they have different adsorption centres on the catalyst surface and are differently affected by photonic flux variations.
Posaconazole Plasma Concentrations in Juvenile Patients with Invasive Fungal Infection
Authors: Krishna Gopal , Sansone-Parsons Angela , Martinho Monika , Kantesaria Bhavna , Pedicone Lisa
Published: January 2007

Posaconazole is an orally bioavailable triazole antifungal agent for the treatment and prophylaxis of invasive fungal infection. We evaluated plasma posaconazole concentration data from juvenile (younger than 18 years;n= 12) and adult (18 to 64 years;n= 194) patients who participated in a multicenter, phase 3, open-label study that assessed the efficacy and safety of posaconazole treatment for persons who were intolerant of or had invasive fungal infection refractory to standard antifungal therapies. With the exception of one juvenile patient who received 400 mg/day as a divided dose on the day of sample collection, all patients received posaconazole at 800 mg/day as an oral suspension in divided doses. Plasma samples were analyzed through a validated liquid chromatographic-tandem mass spectrometric method with a lower limit of quantitation of 1 ng/ml. Because plasma posaconazole concentrations are relatively constant at steady state, the average of all plasma concentrations (Cav) for each patient was calculated to provide a single steady-state plasma posaconazole concentration. A blinded data review committee reviewed all treatment outcomes. Variable posaconazole plasma concentrations were observed within both the juvenile and adult populations. Mean (median [range])Cavvalues for juvenile and adult patients were 776 ng/ml (579 ng/ml [85.3 to 2,891 ng/ml]) and 817 ng/ml (626 ng/ml [0 to 3,710 ng/ml]), respectively. Overall success rates and adverse event profiles were comparable. In conclusion, posaconazole concentrations in plasma were similar for juvenile and adult patients, suggesting that clinical outcomes are expected to be similar in adults and children with refractory invasive fungal infection.
Substrate Competition Studies Using Whole-Cell Accumulation Assays with the Major Tripartite Multidrug Efflux Pumps of
Escherichia coli
Authors: Elkins Christopher A. , Mullis Lisa B.
Published: January 2007

AcrAB-TolC is the major, constitutively expressed tripartite multidrug efflux system in
Escherichia coli
that recognizes various structurally unrelated molecules, including many antibiotics, dyes, and steroids. The AcrB inner membrane pump portion of the efflux system has been shown in recent structural studies to bind substrates at multiple sites, suggesting that particular substrate “sets” may compete for efflux by interfering with a certain binding site(s). However, our data indicate that the general structural class does not appear to dictate a particular substrate binding site that can be competitively inhibited in whole cells. In our study, substrate competition failed to increase cell-associated levels of steroids or dyes to levels characteristic of AcrB- or AcrB/EmrAB-deficient genomic mutants or achieved with the pump inhibitor carbonyl cyanide
m
-chlorophenylhydrazone. In addition, this general observation was sustained even with (i) a cocktail containing seven-pump substrates supplied slightly below their respective wild-type MIC levels, (ii) competing drug substrates of the same structural class (steroids or macrolides), and (iii) hyper-MIC levels of the exogenously supplied agents. Thus, this pump system (and possibly EmrAB-TolC) may have an extraordinary capacity to simultaneously handle multiple-drug substrates that is not necessarily reflected in MIC analyses. In addition, our study has extended the range of substrates recognized by the AcrAB- and EmrAB-TolC systems.
Azithromycin Selectively Reduces Tumor Necrosis Factor Alpha Levels in Cystic Fibrosis Airway Epithelial Cells
Authors: Cigana Cristina , Assael Baroukh Maurice , Melotti Paola
Published: January 2007

Azithromycin (AZM) ameliorates lung function in cystic fibrosis (CF) patients. This macrolide has been suggested to have anti-inflammatory properties as well as other effects potentially relevant for therapy of CF. In this study, we utilized three CF (IB3-1, 16HBE14o- AS3, and 2CFSMEo-) and two isogenic non-CF (C38 and 16HBE14o- S1) airway epithelial cell lines to investigate whether AZM could reduce tumor necrosis factor alpha (TNF-α) mRNA and protein levels by real-time quantitative PCR analysis and an enzyme-linked immunosorbent assay (ELISA), respectively. We studied the effects on the DNA binding of NF-κB and specificity protein 1 (Sp1) by an ELISA. Non-CF cells express significantly lower TNF-α mRNA and protein levels than an isogenic CF cell line. In CF cells, AZM treatment causes a 30% reduction of TNF-α mRNA levels (P< 0.05) and a 45% decrease in TNF-α secretion (P< 0.05), reaching approximately the levels of the untreated isogenic non-CF cells. In CF cells, NF-κB and Sp1 DNA binding activities were also significantly decreased (about 45 and 60%, respectively;P< 0.05) after AZM treatment. Josamycin, a macrolide lacking clinically described anti-inflammatory effects, was ineffective. Finally, AZM did not alter the mRNA expression levels of interleukin-6, a proinflammatory molecule not differentially expressed in CF and isogenic non-CF cells. The results of our study support the anti-inflammatory activities of this macrolide, since we show that AZM reduced the levels of TNF-α and propose inhibitions of NF-κB and Sp1 DNA binding as possible mechanisms of this effect.
Molecular Analysis of the Subgingival Microbiota in Health and Disease
Authors: Ledder Ruth G. , Gilbert Peter , Huws Sharon A. , Aarons Leon , Ashley Martin P. , Hull Peter S. , McBain Andrew J.
Published: January 2007

This investigation provides molecular analyses of the periodontal microbiota in health and disease. Subgingival samples from 47 volunteers with healthy gingivae or clinically diagnosed chronic periodontitis were characterized by PCR-denaturing gradient gel electrophoresis (DGGE) with primers specific for the V2-V3 region of the eubacterial 16S rRNA gene. A hierarchical dendrogram was constructed from band patterns. All unique PCR amplicons (DGGE bands) were sequenced for identity. Samples were also analyzed for the presence of
Actinobacillus actinomycetemcomitans
,
Porphyromonas gingivalis
, and
Tannerella forsythensis
by multiplex PCR. Associations of patient age, gender, and smoking status together with the presence of each unique band and putative periodontal pathogens with disease were assessed by logistic regression. Periodontal pockets were colonized by complex eubacterial communities (10 to 40 distinct DGGE bands) with substantial individual variation in the community profile. Species diversity in health and disease was determined by the Shannon-Weaver index of diversity and compared by the Mann-Whitney U test. Sequence analyses of DGGE amplicons indicated the occurrence of many nontypical oral species and eubacteria previously associated with this environment. With the exception of
T. forsythensis
, the putative pathogens were not detected by DGGE. Multiplex PCR, however, detected
T. forsythensis
,
A. actinomycetemcomitans
, and
P. gingivalis
in 9% 16%, and 29% of the patients with disease, respectively. The presence of
A. actinomycetemcomitans
was significantly associated with disease (
P
< 0.01). Statistical analyses indicated that the presence of
Treponema socranskii
and
Pseudomonas
sp. was a significant predictor of disease (
P
< 0.05) and that there was no significant difference (
P
> 0.05) in terms of eubacterial species diversity between health and disease.
Peritoneal Lavage Cells of Indonesian Thin-Tail Sheep Mediate Antibody-Dependent Superoxide Radical Cytotoxicity In Vitro against Newly Excysted Juvenile
Fasciola gigantica
but Not Juvenile
Fasciola hepatica
Authors: Piedrafita David , Estuningsih Endah , Pleasance Jill , Prowse Rhoda , Raadsma Herman W. , Meeusen Els N. T. , Spithill Terry W.
Published: January 2007

Indonesian thin-tail (ITT) sheep resist infection by
Fasciola gigantica
by an immunological mechanism within 2 to 4 weeks of infection yet are susceptible to
F. hepatica
infection. Studies of ITT sheep show that little liver damage occurs following
F. gigantica
infection, suggesting that the invading parasites are killed within the peritoneum or shortly after reaching the liver. We investigated whether cells isolated from the peritoneums of ITT sheep could kill newly excysted juvenile
F. gigantica
in vitro and act as a potential mechanism of resistance against
F. gigantica
infection. Peritoneal cells from
F. gigantica
-infected sheep, rich in macrophages and eosinophils, mediated antibody-dependent cytotoxicity against juvenile
F. gigantica
in vitro. Cytotoxicity was dependent on contact between the parasite and effector cells. Isolated mammary gland eosinophils of
F. gigantica
-infected sheep, or resident peritoneal monocytes/macrophages from uninfected sheep, also killed the juvenile parasites in vitro. By using inhibitors, we show that the molecular mechanism of killing in these assays was dependent on the production of superoxide radicals by macrophages and eosinophils. In contrast, this cytotoxic mechanism was ineffective against juvenile
F. hepatica
parasites in vitro. Analysis of superoxide dismutase activity and mRNA levels showed that activity and gene expression were higher in
F. hepatica
than in
F. gigantica
, suggesting a possible role for this enzyme in the resistance of
F. hepatica
to superoxide-mediated killing. We suggest that ovine macrophages and eosinophils, acting in concert with a specific antibody, may be important effector cells involved in the resistance of ITT sheep to
F. gigantica
.
The ABCs of IGF-I isoforms: impact on muscle hypertrophy and implications for repair
Authors: Barton Elisabeth R.
Published: January 2007

Insulin-like growth factor I (IGF-I) plays a critical role in the growth and development of many tissues in the body. It is a key regulator of skeletal muscle development, and continues to enhance the ability for muscle to grow and undergo repair throughout life. Although the focus of research has been on the molecular actions and physiological impact of IGF-I, there has also been a growing undercurrent of studies geared toward the characterization of additional potentially active peptides produced by the igf1 gene. Alternative splicing of the gene results in multiple isoforms that retain the identical sequence for mature IGF-I, but also give rise to divergent C-terminal peptides. The peptides might modulate the actions, stability, or bioavailability of IGF-I, or they might have independent activity. These possibilities have gained the attention of the skeletal muscle field, where novel actions of IGF-I could have significant impact on muscle mass, strength, and repair.
Sprint training reduces urinary purine loss following intense exercise in humans
Authors: Stathis Christos G. , Carey Michael F. , Hayes Alan , Garnham Andrew P. , Snow Rodney J.
Published: January 2007

The influence of sprint training on endogenous urinary purine loss was examined in 7 active male subjects (age, 23.1 ± 1.8 y; body mass, 76.1 ± 3.1 kg; VO2 peak, 56.3 ± 4.0 mL·kg–1·min–1). Each subject performed a 30 s sprint performance test (PT), before and after 7 d of sprint training. Training consisted of 15 sprints, each lasting 10 s, on an air-braked cycle ergometer performed twice each day. A rest period of 50 s separated each sprint during training. Sprint training resulted in a 20% higher muscle ATP immediately after PT, a lower IMP (57% and 89%, immediately after and 10 min after PT, respectively), and inosine accumulation (53% and 56%, immediately after and 10 min after the PT, respectively). Sprint training also attenuated the exercise-induced increases in plasma inosine, hypoxanthine (Hx), and uric acid during the first 120 min of recovery and reduced the total urinary excretion of purines (inosine + Hx + uric acid) in the 24 h recovery period following intense exercise. These results show that intermittent sprint training reduces the total urinary purine excretion after a 30 s sprint bout.
A mutation in anexbDgene reduces tagetitoxin production byPseudomonas syringaepv.tagetis
Authors: Kong Hyesuk , Patterson Cheryl D , Mitchell Robin E , Buyer Jeffrey S , Aime M Catherine , Lydon John
Published: January 2007

A mutant of Pseudomonas syringae pv. tagetis EB037 with limited ability to produce tagetitoxin was isolated after transposon mutagenesis and the mutation was characterized. The mutation occurred in a gene with a high degree of sequence identity to exbD. exbD is contiguous with tonB and exbB upstream and with a gene for a TonB-dependent receptor downstream. Using reverse transcription – polymerase chain reaction with RNA from the wild-type and exbD mutant strains, we demonstrated that the mutation in exbD did not have a polar affect on the expression of downstream genes. The exbD mutant was able to grow well in conditions where iron is not freely available. Siderophore production by the exbD mutant was similar to that of the wild-type strain. We conclude that the mutation in exbD disrupts tagetitoxin production without compromising iron metabolism. The results indicate that tagetitoxin export by P. syringae pv. tagetis involves an efflux pump that requires a functional TonB system that is not essential for normal iron metabolism.Key words: Pseudomonas syringae pv. tagetis, Pseudomonas putida, tagetitoxin, exbD, exbB, tonB, TonB system, Helianthus annuus L.
Detection and sequence analysis of an altered pectate lyase gene in Pseudomonas syringae pv. glycinea and related bacteria
Authors: Liao Ching-Hsing , Fett William , Tzean Sean-Shong , Hoffman Gabriel
Published: January 2007

Pectate lyase (PL) is a potent cell wall-degrading enzyme known to play a role in the microbial infection of plants. We re-examined the pectolytic property of seven representative pathovars of Pseudomonas syringae. None of the 10 P. syringae pv. glycinea strains examined exhibited pectolytic activity. However, the PL gene (pel) was detected by Southern hybridization in four out of four P. syringae pv. glycinea strains examined. A P. syringae pv. glycinea pel gene was cloned, sequenced, and predicted to encode a protein sharing 70%–90% identity in amino acid sequence with PLs produced by pectolytic pseudomonads and xanthomonads. A series of amino acid and nucleotide sequence analyses reveal that (i) the predicted P. syringae pv. glycinea PL contains two regions in the amino acid sequence that may affect the formation of a β-helix structure important for the enzyme activity, and (ii) the P. syringae pv. glycinea pel gene contains a single-base insertion, a double-base insertion, and an 18-bp deletion, which can lead to the synthesis of an inactive PL protein. The function of P. syringae pv. glycinea PL could be restored by removing the unwanted base insertions and by filling in the 18-bp deletions by site-directed mutagenesis. The altered pel sequence was also detected by polymerase chain reaction and nucleotide sequencing in the genomes of other pathovars of P. syringae, including phaseolicola and tagetis.Key words: pectate lyase, pel gene, Pseudomonas syringae, detection, analysis.
Microbial communities in the larval midgut of laboratory and field populations of cotton bollworm (Helicoverpa armigera)
Authors: Xiang Hui , Wei Gui-Fang , Jia Shihai , Huang Jianhua , Miao Xue-Xia , Zhou Zhihua , Zhao Li-Ping , Huang Yong-Ping
Published: January 2007

We compared the bacterial communities in the larval midgut of field and laboratory populations of a polyphagous pest, the cotton bollworm (Helicoverpa armigera), using denaturing gradient gel electrophoresis (DGGE) of amplified 16S rDNA sequences and 16S library sequence analysis. DGGE profiles and 16S rDNA library sequence analysis indicated similar patterns of midgut microbial community structure and diversity: specific bacterial types existed in both populations, and a more diverse microbial community was observed in caterpillars obtained from the field. The laboratory population harbored a rather simple gut microflora consisting mostly of phylotypes belonging to Enterococcus (84%). For the field population, phylotypes belonging to Enterococcus (28%) and Lactococcus (11%), as well as Flavobacterium (10%), Acinetobacter (19%), and Stenotrophomonas (10%) were dominant members. These results provided the first comprehensive description of the microbial diversity of the midgut of the important pest cotton bollworm and suggested that the environment and food supply might influence the diversity of the gut bacterial community.Key words: cotton bollworm, midgut, microbial communities, 16S rDNA.
Oxylipin-coated hat-shaped ascospores of Ascoidea corymbosa
Authors: Ncango Desmond M , Pohl Carolina H , Sebolai Olihile M , Botes Piet J , Strauss Catharina J , Joseph Manjusha , Van Wyk Pieter W.J , Nigam Santosh , Kock Johan L.F
Published: January 2007

We previously implicated 3-hydroxy oxylipins and ascospore structure in ascospore release from enclosed asci. Using confocal laser scanning microscopy on cells stained with fluorescein-coupled, 3-hydroxy oxylipin-specific antibodies, we found that oxylipins are specifically associated with ascospores and not the vegetative cells or ascus wall of Ascoidea corymbosa. Using gas chromatography – mass spectrometry the oxylipin 3-hydroxy 17:0 could be identified. Here, we visualize for the first time the forced release of oxylipin-coated, hat-shaped ascospores from terminally torn asci, probably through turgor pressure. We suggest that oxylipin-coated, razor-sharp, hat-shaped ascospore brims may play a role in rupturing the ascus to affect release.Key words: Ascoidea corymbosa, ascospore release, confocal laser scanning microscopy, gas chromatography – mass spectrometry, hat-shaped ascospores, 3-hydroxy oxylipins.
Targeted engineering of Azospirillum brasilense SM with indole acetamide pathway for indoleacetic acid over-expression
Authors: Malhotra Mandira , Srivastava Sheela
Published: January 2007

Rhizospheric bacterial strains are known to produce indole-3-acetic acid (IAA) through different pathways, and such IAA may be beneficial to plants at low concentrations. IAA biosynthesis by a natural isolate of Azospirillum brasilense SM was studied and observed to be tryptophan-inducible and -dependent in nature. While our work demonstrated the operation of the indole pyruvic acid pathway, the biochemical and molecular evidence for the genes of the indole acetamide (IAM) pathway were lacking in A. brasilense SM. This led us to use the IAM pathway genes as targets for metabolic engineering, with the aim of providing an additional pathway of IAA biosynthesis and improving IAA levels in A. brasilense SM. The introduction of the heterologous IAM pathway, consisting of the iaaM and iaaH genes, not only increased the IAA levels by threefold but also allowed constitutive expression of the same genes along with efficient utilization of IAM as a substrate. Such an engineered strain showed a superior effect on the lateral branching of sorghum roots as well as the dry weight of the plants when compared with the wild-type strain. Such an improved bioinoculant could be demonstrated to enhance root proliferation and biomass productivity of treated plants compared with the parental strain.Key words: indole-3-acetic acid, tryptophan, indole-3-acetamide, iaaM-iaaH, metabolic engineering.
Plasmid content and bacteriocin production by five strains ofLactococcus lactisisolated from semi-hard homemade cheese
Authors: Kojic Milan , Strahinic Ivana , Fira Djordje , Jovcic Branko , Topisirovic Ljubisa
Published: January 2007

In this study, the plasmid content and bacteriocin production of natural isolates of lactococci were investigated. Five bacteriocin producing lactococcal strains (Lactococcus lactis subsp. lactis BGMN1-2, BGMN1-3, BGMN1-5, BGMN1-6, and BGMN2-7) were isolated as nonstarter microflora of semi-hard homemade cheese and characterized. All isolates contained a number of plasmids. It was shown that lcnB structural genes for bacteriocin lactococcin B were located on large plasmids in all isolates. In the strains BGMN1-3 and BGMN1-5 proteinase prtP genes collocated with lcnB. Furthermore, these strains produced two additional bacteriocins (LsbA and LsbB) with genes responsible for their production and immunity located on the small rolling circle-replicating plasmid pMN5. Using deletion experiments of pMN5, minimal replicon of the plasmid and involvement of a bacteriocin locus in plasmid maintenance were identified. In addition, plasmid curing experiments showed that genes for catabolism or transport of 10 carbohydrates in the strain BGMN1-5 were plasmid located.Key words: lactococci, natural isolates, bacteriocin, plasmid curing.
Enhanced solubilization of rock phosphate by Penicillium bilaiae in pH-buffered solution culture
Authors: Takeda M , Knight J D
Published: January 2007

Little is known about how pH-buffering capacity affects phosphorus (P) solubilization by Penicillium bilaiae. This study compared solubilization of rock phosphate (RP) by P. bilaiae in nonbuffered (pH 5.0) and buffered (pH 7.0) media. Fungal growth reached the stationary phase around day 12 and was slightly enhanced in the buffered medium. The fungus reduced solution pH from 5.0 to 4.1 in the nonbuffered medium and from 7.0 to 4.9 in the buffered medium by day 12. Phosphorus concentrations increased after day 9 more in the buffered than in the nonbuffered media (53 and 5 mg P·L–1, respectively, on day 12). On day 12, higher concentrations of citric and oxalic acids were detected in the buffered (2.0 and 1.2 g·L–1, respectively) than nonbuffered media (0.5 and 0.04 g·L–1, respectively). Solubilization of RP was simulated without P. bilaiae in solutions equivalent to the nonbuffered and buffered cultures of P. bilaiae grown with RP. After a 24 h incubation, the P concentrations were of similar magnitudes to those observed in the P. bilaiae culture (18 and 47 mg P·L–1, respectively, in the nonbuffered and buffered media). Under increased pH-buffering conditions, the enhanced production of citric and oxalic acids led to significant RP solubilization.Key words: phosphorus solubilization, pH buffering, Penicillium bilaiae, citric acid, oxalic acid.
Insulin-sensitizing effects of thiazolidinediones are not linked to adiponectin receptor expression in human fat or muscle
Authors: Li Weijie , Tonelli Julia , Kishore Preeti , Owen Randall , Goodman Elliot , Scherer Philipp E. , Hawkins Meredith
Published: January 2007

Circulating adiponectin levels are increased by the thiazolidinedione (TZD) class of PPARγ agonists in concert with their insulin-sensitizing effects. Two receptors for adiponectin (AdipoR1 and AdipoR2) are widely expressed in many tissues, but their physiological significance to human insulin resistance remains to be fully elucidated. We examined the expression patterns of AdipoR1 and AdipoR2 in fat and skeletal muscle of human subjects, their relationship to insulin action, and whether they are regulated by TZDs. Expression patterns of both AdipoRs were similar in subcutaneous and omental fat depots, with higher expression in adipocytes than in stromal cells and macrophages. To determine the effects of TZDs on AdipoR expression, subcutaneous fat and quadriceps muscle were biopsied in 14 insulin-resistant subjects with type 2 diabetes mellitus after 45 mg pioglitazone or placebo for 21 days. This duration of pioglitazone improved insulin's suppression of glucose production by 41% and enhanced stimulation of glucose uptake by 27% in concert with increased gene expression and plasma levels of adiponectin. Pioglitazone did not affect AdipoR expression in muscle, whole fat, or cellular adipose fractions, and receptor expression did not correlate with baseline or TZD-enhanced insulin action. In summary, both adiponectin receptors are expressed in cellular fractions of human fat, particularly adipocytes. TZD administration for sufficient duration to improve insulin action and increase adiponectin levels did not affect expression of AdipoR1 or AdipoR2. Although TZDs probably exert many of their effects via adiponectin, changes in these receptors do not appear to be necessary for their insulin-sensitizing effects.
A single transient episode of hyperammonemia induces long-lasting alterations in protein kinase A
Authors: Montoliu Carmina , Piedrafita Blanca , Serra Miguel A. , del Olmo Juan A. , Rodrigo José M. , Felipo Vicente
Published: January 2007

Hepatic encephalopathy in patients with liver disease is associated with poor prognosis. This could be due to the induction by the transient episode of hepatic encephalopathy of long-lasting alterations making patients more susceptible. We show that a single transient episode of hyperammonemia induces long-lasting alterations in signal transduction. The content of the regulatory subunit of the protein kinase dependent on cAMP (PKA-RI) is increased in erythrocytes from cirrhotic patients. This increase is reproduced in rats with portacaval anastomosis and in rats with hyperammonemia without liver failure, suggesting that hyperammonemia is responsible for increased PKA-RI in patients. We analyzed whether there is a correlation between ammonia levels and PKA-RI content in patients. All cirrhotic patients had increased content of PKA-RI. Some of them showed normal ammonia levels but had suffered previous hyperammonemia episodes. This suggested that a single transient episode of hyperammonemia could induce the long-lasting increase in PKA-RI. To assess this, we injected normal rats with ammonia and blood was taken at different times. Ammonia returned to basal levels at 2 h. However, PKA-RI was significantly increased in blood cells from rats injected with ammonia 3 wk after injection. In conclusion, it is shown that a single transient episode of hyperammonemia induces long-lasting alterations in signal transduction both in blood and brain. These alterations may contribute to the poor prognosis of patients suffering hepatic encephalopathy.
17β-Estradiol modulates vasoconstriction induced by endothelin-1 following trauma-hemorrhage
Authors: Ba Zheng F. , Lu Ailing , Shimizu Tomoharu , Szalay László , Schwacha Martin G. , Rue Loring W. , Bland Kirby I. , Chaudry Irshad H.
Published: January 2007

Although endothelin-1 (ET-1) induces vasoconstriction, it remains unknown whether 17β-estradiol (E2) treatment following trauma-hemorrhage alters these ET-1-induced vasoconstrictive effects. In addition, the role of the specific estrogen receptor (ER) subtypes (ER-α and ER-β) and the endothelium-localized downstream mechanisms of actions of E2remain unclear. We hypothesized that E2attenuates increased ET-1-induced vasoconstriction following trauma-hemorrhage via an ER-β-mediated pathway. To study this, aortic rings were isolated from male Sprague-Dawley rats following trauma-hemorrhage with or without E2treatment, and alterations in tension were determined in vitro. Dose-response curves to ET-1 were determined, and the vasoactive properties of E2, propylpyrazole triol (PPT, ER-α agonist), and diarylpropionitrile (DPN, ER-β agonist) were determined. The results showed that trauma-hemorrhage significantly increased ET-1-induced vasoconstriction; however, administration of E2normalized ET-1-induced vasoconstriction in trauma-hemorrhage vessels to the sham-operated control level. The ER-β agonist DPN counteracted ET-1-induced vasoconstriction, whereas the ER-α agonist PPT was ineffective. Moreover, the vasorelaxing effects of E2were not observed in endothelium-denuded aortic rings or by pretreatment of the rings with a nitric oxide (NO) synthase inhibitor. Cyclooxygenase inhibition with indomethacin had no effect on the action of E2. Thus, E2administration attenuates ET-1-induced vasoconstriction following trauma-hemorrhage via an ER-β-mediated pathway that is dependent on endothelium-derived NO synthesis.
In utero nicotine exposure alters fetal rat lung alveolar type II cell proliferation, differentiation, and metabolism
Authors: Rehan Virender K. , Wang Ying , Sugano Sharon , Santos Jamie , Patel Sanjay , Sakurai Reiko , Boros Laszlo W. , Lee W.-P. , Torday John S.
Published: January 2007

We recently suggested that alveolar interstitial fibroblast-to-myofibroblast transdifferentiation may be a key mechanism underlying in utero nicotine-induced lung injury. However, the effects of in utero nicotine exposure on fetal alveolar type II (ATII) cells have not been fully determined. Placebo, nicotine (1 mg/kg), or nicotine (1 mg/kg) + the peroxisome proliferator-activated receptor (PPAR)-γ agonist prostaglandin J2 (PGJ2, 0.3 mg/kg) was administered intraperitoneally once daily to time-mated pregnant Sprague-Dawley rats from embryonic day 6 until their death on embryonic day 20. Fetal ATII cells were isolated, and ATII cell proliferation, differentiation (surfactant synthesis), and metabolism (metabolic profiling with the stable isotope [1,2-13C2]-d-glucose) were determined after nicotine exposure in utero or in vitro. In utero nicotine exposure significantly stimulated ATII cell proliferation, differentiation, and metabolism. Although the effects on ATII cell proliferation and metabolism were almost completely prevented by concomitant treatment with PGJ2, the effects on surfactant synthesis were not. On the basis of in utero and in vitro data, we conclude that surfactant synthesis is stimulated by nicotine's direct effect on ATII cells, whereas cell proliferation and metabolism are affected via a paracrine mechanism(s) secondary to its effects on the adepithelial fibroblasts. These data provide evidence for direct and indirect effects of in utero nicotine exposure on fetal ATII cells that could permanently alter the “developmental program” of the developing lung. More importantly, concomitant administration of PPAR-γ agonists can effectively attenuate many of the effects of in utero exposure to nicotine on ATII cells.
Hyperoxic conditions inhibit airway smooth muscle myosin phosphatase in rat pups
Authors: Smith Paul G. , Dreshaj Albana , Chaudhuri Subhendu , Onder Baran M. , Mhanna Maroun J. , Martin Richard J.
Published: January 2007

Exposure of rat pups to 100% oxygen is a model for studying neonatal lung injury. Airway reactivity is increased in this model, in part due to impaired airway smooth muscle (ASM) relaxation. We compared biochemical determinants of ASM contractility in rat pups exposed to 100% oxygen for 7 days vs. littermates raised in room air. The baseline quantities of ASM contractile proteins, extent of phosphorylation of the 20-kDa myosin regulatory light chain (LC20), and amount of the myosin-binding subunit of smooth muscle myosin phosphatase (MYPT) were all comparable between the two groups. Bethanechol-induced contraction increased the extent of phosphorylation of both LC20 and MYPT in the hyperoxic group (45% and 70% over control, respectively). Relaxation after electrical field stimulation demonstrated greater phosphorylation of both LC20 and MYPT in the hyperoxic group compared with controls (67% and 84%, respectively). To determine if hyperoxia induced changes in the isoforms of MYPT, isoform expression was also compared but differences were not found. To determine potential mechanisms whereby MYPT phosphorylation was increased by hyperoxia, separate tracheas were treated with the Rho kinase inhibitor Y-27632. This treatment completely eliminated differences in MYPT phosphorylation between the groups. Because phosphorylation of MYPT impairs the phosphatase activity of myosin phosphatase, these data suggest that hyperoxic conditioning during early postnatal life impairs relaxation through prolonging LC20 phosphorylation. This mechanism might contribute to increased ASM reactivity seen in bronchopulmonary dysplasia.
The role played by endocytosis in albumin-induced secretion of TGF-β1by proximal tubular epithelial cells
Authors: Diwakar Ramaswamy , Pearson Alex L. , Colville-Nash Paul , Brunskill Nigel J. , Dockrell Mark E. C.
Published: January 2007

Proteinuria predicts the decline of renal function in chronic kidney disease. Reducing albuminuria has been shown to be associated with a reduction in this rate of decline. Proximal tubular epithelial cells (PTECs), when exposed to albumin produce matrix proteins, proinflammatory and profibrotic cytokines like TGF-β1. Some of these effects are dependent on endocytosis of albumin by PTECs. However, conditions like diabetic nephropathy, believed to be associated with reduced albumin endocytosis, are associated with interstitial fibrosis. Moreover, megalin, the putative albumin binding receptor in PTECs, has potential signaling motifs in its cytoplasmic domain, suggesting its ability to signal in response to ligand binding from the apical surface of PTECs. Hence, we looked to see whether albumin-induced secretion of TGF-β1by PTECs is dependent on albumin endocytosis or whether it could occur in the absence of albumin endocytosis. We studied the production of TGF-β1in two accepted models of PTECs, opossum kidney cells and human kidney cell clone-8 cells, with widely varying degrees of endocytosis. We then studied the effect of inhibiting albumin endocytosis with various inhibitors on albumin-induced TGF-β1secretion. Our results indicate that albumin-induced TGF-β1secretion by PTECs does not require albumin endocytosis and therefore the mechanism for the induction of some profibrotic responses by albumin may differ from those required for some of the inflammatory responses. Moreover, we found that albumin-induced TGF-β1secretion by PTECs is not dependent on its interaction with megalin.