bluuebunny/crossref_metadata_2025 huggingface dataset:
Managing and Sustaining Your Juvenile Drug Court
Authors: Van Wormer Jacqueline , Lutze Faith E.
Published: May 2010

Since the introduction and subsequent growth of the juvenile drug court movement in the mid‐1990s, practitioners have struggled to fully implement the Juvenile Drug Courts: Strategies in Practice. This struggle may lead to weaker outcomes for youth and a dysfunctional team atmosphere.

Originally written as a two‐part technical assistance brief, this article will guide readers through the Juvenile Drug Court Development Cycle in order to help re‐direct practitioners to a more “back‐to‐basics” approach that focuses on collaboration, team dynamics, and decision making.
ORIGINAL ARTICLE: Immunohistochemical identification of basal‐like breast carcinoma and Its histopathologic correlation
Authors: Chin Susie , Koh Eun Suk , Kwak Jeong Ja , Kim Hee Kyung , Lee Hee Jung , Lim Cheol Wan
Published: May 2010

Background and aim: DNA expression profiling studies of breast cancer have identified subtypes including luminal A, luminal B, human epidermal growth factor receptor 2 (HER2) overexpression, and basal‐like type. Among them, the basal‐like type was associated with poor outcome. The purpose of this study was to classify breast carcinoma by immunohistochemistry and evaluate its characteristic histopathologic features. Methods: One hundred and four cases of resected infiltrating ductal carcinoma were immunostained for estrogen receptor, HER2, cytokeratin 5/6 and p63 to classification, and basal‐like subtype were evaluated for its histopathologic characteristics. Results: The prevalence of subtypes was luminal A 48.1%, luminal B 24.0%, HER2 overexpression 11.5%, normal breast‐like 4.8%, and basal‐like 11.5%. There was significant correlation between the basal‐like type and histologic grade. And it was significantly associated with several morphological features including expanding growth pattern, presence of tumor necrosis and peritumoral lymphocytic infiltration. Conclusions: The results of this study showed that the basal‐like type occupied 11.5% of infiltrating ductal carcinoma and was associated with expanding growth pattern, presence of tumor necrosis and peritumoral lymphocytic infiltration.
CASE REPORT: Plasmacytoid urothelial carcinoma of the urinary bladder: Two case reports
Authors: Nicolas Marlo M , Sanchez‐Salazar Alma J , Guo Charles C
Published: May 2010

We report two cases of plasmacytoid urothelial carcinoma of the urinary bladder. The tumor in the first case presented as an irregular and erythematous urinary bladder lesion with pararectal or rectal tumor extension. Perineal, scrotal and intrabdominal metastases developed within 4 months despite neoadjuvant chemotherapy. A muscle‐invasive urinary bladder tumor was seen in the second case with perivesical and perivesicular extension and regional lymph metastases at cystoprostatectomy. The tumor cells in both cases were nested or dyscohesive, and resembled plasma cells; focal signet ring cells were also seen in the second case. The advanced stage of both cases is consistent with the reported aggressive biologic course of most of these tumors. Awareness of this rare variant when dealing with urogenital tract carcinoma is important since the morphology may suggest another diagnosis. Because of peculiar expression of CD138, a plasma cell‐associated marker, these tumors may be mistaken for a plasma cell‐derived neoplasm.
Coracoid Impingement Treated with Corrective Osteotomy. A Case Report
Authors: Reddy Venuthurla R. , Okoro Tosan , Rennie Winston , Modi Amit
Published: May 2010

Coracoid impingement syndrome is a rare cause of anterior shoulder pain. It is mainly a diagnosis of exclusion after considering the more common subacromial impingement. We describe a case of coracoid impingement and a novel approach to its management: coracoid osteotomy as opposed to the more commonly used technique of coracoplasty. A review of the literature is also presented in relation to this condition. Coracoid osteotomy with internal fixation allows good stability with reliable direct bone-to-bone healing. Coracoid osteotomy is a reliable and a satisfactory alternative to the more commonly-used technique of coracoplasty for the treatment of idiopathic coracoid impingement syndrome.
Multidirectional Instability of the Shoulder: Does it Exist?
Authors: Corner Tony , Emery Roger
Published: May 2010

Multidirectional instability (MDI) of the shoulder is a complex condition which remains a great challenge for orthopaedic surgeons to fully understand and successfully treat. We explore the origins of MDI of the shoulder and review the basic science of its proposed aetiology and the results of non-operative and operative treatment modalities. We then propose a new theory as to the aetiology and treatment of this complex condition.
Partial Thickness Rotator Cuff Tears: What Do We Know?
Authors: Smith Christopher D. , Corner Tony , Morgan David , Drew Steve
Published: May 2010

Partial thickness rotator cuff tears are not an uncommon pathology encountered within the sporting community. However, the pathology associated with them has not been well documented. This has lead to difficulty in the diagnosis and classification of these injuries and their optimal treatment is yet to be decided. This review presents the current literature on partial thickness rotator cuff tears, including their incidence, aetiology and pathology. The available literature on diagnosis and treatment is also presented. It is hoped that this review will provide the clinician with a concise summary of the current knowledge of partial tears and help to direct the clinician in the management of these injuries. The review also highlights those areas where further evidence is required.
Biceps Rupture in Water-related Sporting Activities
Authors: Lo Cheng H. , Coombs Christopher , Bell Simon N.
Published: May 2010

Closed traumatic disruptions of biceps brachii muscle belly are rarely seen. In this paper, we report two rare cases of biceps brachii muscle belly rupture sustained while water-skiing or wakeboarding and discuss the mechanism of injury, management and outcomes after a literature review. A review of published articles revealed only three previously reported cases of water skiing related biceps muscle rupture. It is important to be vigilant of these injuries, given that early recognition and operative intervention with or without direct muscle repair may optimise outcomes.
Healing of the Greater Tuberosity in Acute Shoulder Hemiarthroplasty Using an Accelerated Rehabilitation Regime
Authors: Macfarlane Robert J. , Ali Zulfikar , Datt Dipankar , Venkateswaran Balachandran
Published: May 2010

Background

Displaced three- and four-part proximal humerus fractures are common and are frequently treated by shoulder hemiarthroplasty. The present study sought to evaluate an accelerated rehabilitaton regime following hemiarthoplasty and assess its affect on healing of the greater tuberosities.

Methods

Twenty patients over a 2-year period treated with acute hemiarthroplasty were rehabilitated with an accelerated regime of passive movements on day 1, active movements from the second week, and strengthening from the fourth postoperative week. Clinical and radiological follow-up was at 12 months.

Results

At 6 months, the mean Constant functional shoulder score was 55.52 (range 14 to 78). The average maximum forward elevation was 98.47° (range 30° to 160°). The mean pain score at 6 months was 11.42 (range 0 to 15). Twenty-two of 23 patients went on to heal radiologically by 3 months, with one case undergoing resorption of the tuberosities as a result of falls and a cerebrovascular event affecting the limb. At 3 months, 20/23 patients had undergone tuberosity healing with less than 0.5 cm displacement (86.9% of patients).

Discussion

An accelerated rehabilitation regime does not adversely affect the rate of healing of the tuberosities following shoulder hemiarthroplasty for proximal humerus fractures. The use of an early mobilization regime is likely to allow an earlier return to normal activities of daily living.
Biomechanical Evaluation of Different Designs of Glenospheres in the SMR Reverse Shoulder Prosthesis: Micromotion of the Baseplate and Risk of Loosening
Authors: Poon Peter C. , Chou Justin , Young Darryl , Malak Sharif F. , Anderson Iain A.
Published: May 2010

Background

Early outcomes of reverse shoulder arthroplasty have been encouraging. Scapular notching remains a major concern. In an attempt to reduce this problem, newer glenospheres are available. This biomechanical study performed in vitro, assessed the micromotions of baseplate in different designs of glenospheres and the relative risk of loosening.

Methods

A dynamic shear force was applied to each type of glenosphere in various angles of abduction. The micromotion of the glenoid baseplate after 1000 cycles of dynamic loading was measured and compared.

Results

Eccentric glenospheres were shown to have increased micromotion compared to the concentric designs of the same size. The greatest baseplate micromotion (26.83 μm) was well within the accepted limit for osseous in growth into uncemented prosthesis.

Discussion

We therefore conclude that the magnitude of the increased micromotion is small and is not expected to adversely affect osseous in growth onto the glenoid baseplate.
Interference Fit: A Novel Method for Strong Knotless Arthroscopic Fixation of Sutures to Bone
Authors: Ramesh Rangaraju , Szymankiewicz James , Hooper Robert M. , Bunker Timothy D.
Published: May 2010

Background

The present study examined the strength of fixation of a knotless anchor system that relies on trapping the suture between an interference fit screw and its bone tunnel, a method familiar to orthopaedic surgeons during anterior cruciate ligament reconstruction.

Type of study

In vitro biomechanical single-pull load to failure study of fixation achieved by interference fit screws in porcine bone. A standard suture anchor with eyelet was used as a control.

Methods

A single-pull to failure test was carried out on a Hounsfield H20K digital tensiometer (Tinius Olsen, Hersham, PA, USA). Two suture materials were compared [braided polyester (Ethibond; Ethicon Ltd, Edinburgh, UK) and a new suture (Fibrewire; Arthrex Inc., Naples, FL, USA) that has a high molecular weight polyethylene core]. Two interference fit screws were compared: one metal and the other plastic (PEEK; Parkus Medical, Sturgeon Bay, WI, USA).

Results

The average values were between 262 N and 584 N. The average failure value for a standard anchor was 206 N.

Clinical Relevance

Interference fit fixation provides an elegant strong knotless method for securing multiple sutures to a single point.
Biopsy and diagnostic histopathology in dental practice in Brisbane: usage patterns and perceptions of usefulness
Authors: Wan A , Savage NW
Published: May 2010

Background:  Biopsy procedures and diagnostic histopathology are rarely used by general dental practitioners (GDPs) compared with dental specialists. The aim of this study was to investigate the usage patterns and views of GDPs and specialists in Brisbane on these procedures.

Methods:  An analysis was carried out on 1027 oral biopsy accessions at a private pathology laboratory. A survey was distributed to 200 GDPs and dental specialists inquiring about their use of and views on biopsy and diagnostic histopathology. An analysis was carried out on 327 and 95 biopsies performed at a private oral medicine practice and at the University of Queensland School of Dentistry, respectively.

Results:  The majority (76.2%) of GDPs surveyed referred all oral lesions requiring biopsy to a specialist, rather than undertaking biopsy themselves. Although most GDPs recognized the importance of biopsy, a large proportion (58.1%) did not feel competent in undertaking the procedure due to concerns of inadequate experience and practical skills.

Conclusions:  Many dental practitioners believe that GDPs should be able to undertake simple biopsies of benign lesions, however more undergraduate and postgraduate training in biopsy and diagnostic histopathology is necessary to promote a greater use of these procedures.
Non‐carious cervical lesions on permanent anterior teeth: a new morphological classification
Authors: Michael JA , Kaidonis JA , Townsend GC
Published: May 2010

Background:  Various cross‐sectional forms of non‐carious cervical lesions have been described but no formal morphological classification system has been developed. The aims of this study were to describe the spectrum of common morphological forms of non‐carious cervical lesions observed within a large sample of extracted human permanent anterior teeth and to develop a system for classification based on morphological features.

Methods:  Over 15 000 extracted permanent anterior teeth were examined macroscopically under illumination at 2× magnification. Well‐defined, descriptive categories were formed, based on observable non‐carious cervical lesion features and using terminology currently reported in the literature. The lesions were then sorted into these categories.

Results:  Five hundred and forty‐two non‐carious cervical lesions were identified on 15 289 teeth extracted in the early to mid 20th century, representing a frequency of 3.5%. The main categories developed were “shallow”, “concave”, “wedge‐shaped”, “notched”, and “irregular”.

Conclusions:  The new morphological classification system provides an alternative to presently used systems based on aetiology, and should facilitate future research on non‐carious cervical lesions.
Muscle‐specific expression of hypoxia‐inducible factor in human skeletal muscle
Authors: Mounier Rémi , Pedersen Bente Klarlund , Plomgaard Peter
Published: May 2010

Skeletal muscle is well known to exhibit a high degree of plasticity depending on environmental changes, such as various oxygen concentrations. Studies of the oxygen‐sensitive subunit α of hypoxia‐inducible factor‐1 (HIF‐1) are difficult owing to the large variety of functionally diverse muscle fibres that possess unique patterns of protein and gene expression, producing different capillarization and energy metabolism systems. In this work, we analysed HIF‐1α mRNA and protein expression related to the fibre‐type composition in untrained human skeletal muscle by obtaining muscle biopsies from triceps brachii (characterized by a high proportion of type II fibres), from soleus (characterized by a high proportion of type I fibres) and from vastus lateralis (characterized by an equal proportion of type I and II fibres). The hypothesis was that type I muscle fibres would have lower HIF‐1α mRNA and protein owing to their higher oxidative capacity. We have shown, in normoxic conditions, a higher HIF‐1α protein expression in predominantly oxidative muscles than in predominantly glycolytic muscles. However, the HIF‐1α mRNA expression pattern was not in agreement with the HIF‐1α protein level. Interestingly, none of the HIF‐1α target genes, like the most studied angiogenic factor involved in muscle angiogenesis, vascular endothelial growth factor (VEGF), exhibited a muscle fibre‐specific‐related mRNA expression at rest in normoxia. However, soleus presented a significantly higher VEGF protein content than vastus lateralis and triceps muscle. In conclusion, we have shown that there are muscle‐specific differences in HIF‐1α and VEGF expression within human skeletal muscle at rest in normoxic conditions. Recent results, when combined with the findings described here, support a key role for HIF‐1α for maintaining muscle homeostasis in non‐hypoxic conditions.
Magnetospirillum bellicus
sp. nov., a Novel Dissimilatory Perchlorate-Reducing Alphaproteobacterium Isolated from a Bioelectrical Reactor
Authors: Thrash J. Cameron , Ahmadi Sarir , Torok Tamas , Coates John D.
Published: May 2010

Previously isolated dissimilatory perchlorate-reducing bacteria (DPRB) have been primarily affiliated with the
Betaproteobacteria
. Enrichments from the cathodic chamber of a bioelectrical reactor (BER) inoculated from creek water in Berkeley, CA, yielded a novel organism most closely related to a previously described strain, WD (99% 16S rRNA gene identity). Strain VDY
T
has 96% 16S rRNA gene identity to both
Magnetospirillum gryphiswaldense
and
Magnetospirillum magnetotacticum
, and along with strain WD, distinguishes a clade of perchlorate-reducing
Magnetospirillum
species in the
Alphaproteobacteria
. In spite of the phylogenetic location of VDY
T
, attempted PCR for the key magnetosome formation genes
mamI
and
mamL
was negative. Strain VDY
T
was motile, non-spore forming, and, in addition to perchlorate, could use oxygen, chlorate, nitrate, nitrite, and nitrous oxide as alternative electron acceptors with acetate as the electron donor. Transient chlorate accumulation occurred during respiration of perchlorate. The organism made use of fermentation end products, such as acetate and ethanol, as carbon sources and electron donors for heterotrophic growth, and in addition, strain VDY
T
could grow chemolithotrophically with hydrogen serving as the electron donor. VDY
T
contains a copy of the RuBisCo
cbbM
gene, which was expressed under autotrophic but not heterotrophic conditions. DNA-DNA hybridization with strain WD confirmed VDY
T
as a separate species (46.2% identity), and the name
Magnetospirillum bellicus
sp. nov. (DSM 21662, ATCC BAA-1730) is proposed.
Integration of Insecticidal Protein Vip3Aa1 into
Beauveria bassiana
Enhances Fungal Virulence to
Spodoptera litura
Larvae by Cuticle and
Per
Os
Infection
Authors: Qin Yi , Ying Sheng-Hua , Chen Ying , Shen Zhi-Cheng , Feng Ming-Guang
Published: May 2010

The entomopathogenic fungus
Beauveria bassiana
acts slowly on insect pests through cuticle infection. Vegetative insecticidal proteins (Vip3A) of
Bacillus thuringiensis
kill lepidopteran pests rapidly, via
per os
infection, but their use for pest control is restricted to integration into transgenic plants. A transgenic
B. bassiana
strain (BbV28) expressing Vip3Aa1 (a Vip3A toxin) was thus created to infect the larvae of the oriental leafworm moth
Spodoptera litura
through conidial ingestion and cuticle adhesion. Vip3Aa1 (∼88 kDa) was highly expressed in the conidial cytoplasm of BbV28 and was detected as a digested form (∼62 kDa) in the larval midgut 18 and 36 h after conidial ingestion. The median lethal concentration (LC
50
) of BbV28 against the second-instar larvae feeding on cabbage leaves sprayed with conidial suspensions was 26.2-fold lower than that of the wild-type strain on day 3 and 1.1-fold lower on day 7. The same sprays applied to both larvae and leaves for their feeding reduced the LC
50
of the transformant 17.2- and 1.3-fold on days 3 and 7, respectively. Median lethal times (LT
50
s) of BbV28 were shortened by 23 to 35%, declining with conidial concentrations. The larvae infected by ingestion of BbV28 conidia showed typical symptoms of Vip3A action, i.e., shrinkage and palsy. However, neither LC
50
nor LT
50
trends differed between BbV28 and its parental strain if the infection occurred through the cuticle only. Our findings indicate that fungal conidia can be used as vectors for spreading the highly insecticidal Vip3A protein for control of foliage feeders such as
S. litura
.
Genetic Characterization of
Vibrio vulnificus
Strains from Tilapia Aquaculture in Bangladesh
Authors: Mahmud Zahid H. , Wright Anita C. , Mandal Shankar C. , Dai Jianli , Jones Melissa K. , Hasan Mahmud , Rashid Mohammad H. , Islam Mohammad S. , Johnson Judith A. , Gulig Paul A. , Morris J. Glenn , Ali Afsar
Published: May 2010

Outbreaks of
Vibrio vulnificus
wound infections in Israel were previously attributed to tilapia aquaculture. In this study,
V. vulnificus
was frequently isolated from coastal but not freshwater aquaculture in Bangladesh. Phylogenetic analyses showed that strains from Bangladesh differed remarkably from isolates commonly recovered elsewhere from fish or oysters and were more closely related to strains of clinical origin.
Searching for Mesophilic
Thermotogales
Bacteria: “Mesotogas” in the Wild
Authors: Nesbø Camilla L. , Kumaraswamy Rajkumari , Dlutek Marlena , Doolittle W. Ford , Foght Julia
Published: May 2010

All cultivated
Thermotogales
are thermophiles or hyperthermophiles. However, optimized 16S rRNA primers successfully amplified
Thermotogales
sequences from temperate hydrocarbon-impacted sites, mesothermic oil reservoirs, and enrichment cultures incubated at <46°C. We conclude that distinct
Thermotogales
lineages commonly inhabit low-temperature environments but may be underreported, likely due to “universal” 16S rRNA gene primer bias.
Genetic and Proteomic Analysis of Factors Affecting Serum Cholesterol Reduction by
Lactobacillus acidophilus
A4
Authors: Lee Jin , Kim Younghoon , Yun Hyun Sun , Kim Jong Gun , Oh Sejong , Kim Sae Hun
Published: May 2010

This article identifies novel factors involved in cholesterol reduction by probiotic bacteria, which were identified using genetic and proteomic approaches. Approximately 600
Lactobacillus acidophilus
A4 mutants were created by random mutagenesis. The cholesterol-reducing ability of each mutant was determined and verified using two different methods: the
o
-phthalaldehyde assay and gas chromatographic analysis (GC). Among screened mutants, strain BA9 showed a dramatically diminished ability to reduce cholesterol, as demonstrated by a 7.7% reduction rate, while the parent strain had a more than 50% reduction rate. The transposon insertion site was mapped using inverse PCR (I-PCR), and it was determined using bioinformatic methods that the deleted region contained the
Streptococcus thermophilus
catabolite control protein A gene (
ccpA
). In addition, we have shown using two-dimensional gel electrophoresis (2-DE) that several proteins, including a transcription regulator, FMN-binding protein, major facilitator superfamily permease, glycogen phosphorylase, the YknV protein, and fructose/tagatose bisphosphate aldolase, were strongly regulated by the
ccpA
gene. In addition,
in vivo
experiments investigating
ccpA
function were conducted with rats. Rats fed wild-type
L. acidophilus
A4 showed a greater than 20% reduction in total serum cholesterol, but rats fed BA9 mutant
L. acidophilus
showed only an approximately 10% reduction in cholesterol. These results provide important insights into the mechanism by which these lactic acid bacteria reduce cholesterol.
Influence of Soil Characteristics on the Diversity of Bacteria in the Southern Brazilian Atlantic Forest
Authors: Faoro H. , Alves A. C. , Souza E. M. , Rigo L. U. , Cruz L. M. , Al-Janabi S. M. , Monteiro R. A. , Baura V. A. , Pedrosa F. O.
Published: May 2010

The Brazilian Atlantic Forest is one of the 25 biodiversity hot spots in the world. Although the diversity of its fauna and flora has been studied fairly well, little is known of its microbial communities. In this work, we analyzed the Atlantic Forest ecosystem to determine its bacterial biodiversity, using 16S rRNA gene sequencing, and correlated changes in deduced taxonomic profiles with the physicochemical characteristics of the soil. DNAs were purified from soil samples, and the 16S rRNA gene was amplified to construct libraries. Comparison of 754 independent 16S rRNA gene sequences from 10 soil samples collected along a transect in an altitude gradient showed the prevalence of
Acidobacteria
(63%), followed by
Proteobacteria
(25.2%),
Gemmatimonadetes
(1.6%),
Actinobacteria
(1.2%),
Bacteroidetes
(1%),
Chloroflexi
(0.66%),
Nitrospira
(0.4%),
Planctomycetes
(0.4%),
Firmicutes
(0.26%), and OP10 (0.13%). Forty-eight sequences (6.5%) represented unidentified bacteria. The Shannon diversity indices of the samples varied from 4.12 to 3.57, indicating that the soils have a high level of diversity. Statistical analysis showed that the bacterial diversity is influenced by factors such as altitude, Ca
2+
/Mg
2+
ratio, and Al
3+
and phosphorus content, which also affected the diversity within the same lineage. In the samples analyzed, pH had no significant impact on diversity.
Promotion of Mn(II) Oxidation and Remediation of Coal Mine Drainage in Passive Treatment Systems by Diverse Fungal and Bacterial Communities
Authors: Santelli Cara M. , Pfister Donald H. , Lazarus Dana , Sun Lu , Burgos William D. , Hansel Colleen M.
Published: May 2010

Biologically active, passive treatment systems are commonly employed for removing high concentrations of dissolved Mn(II) from coal mine drainage (CMD). Studies of microbial communities contributing to Mn attenuation through the oxidation of Mn(II) to sparingly soluble Mn(III/IV) oxide minerals, however, have been sparse to date. This study reveals a diverse community of Mn(II)-oxidizing fungi and bacteria existing in several CMD treatment systems.
Parallel Analyses of
Alexandrium catenella
Cell Concentrations and Shellfish Toxicity in the Puget Sound
Authors: Dyhrman Sonya T. , Haley Sheean T. , Borchert Jerry A. , Lona Bob , Kollars Nicole , Erdner Deana L.
Published: May 2010

Alexandrium catenella
is widespread in western North America and produces a suite of potent neurotoxins that cause paralytic shellfish poisoning (PSP) in humans and have deleterious impacts on public health and economic resources. There are seasonal PSP-related closures of recreational and commercial shellfisheries in the Puget Sound, but the factors that influence cell distribution, abundance, and relationship to paralytic shellfish toxins (PSTs) in this system are poorly described. Here, a quantitative PCR assay was used to detect
A. catenella
cells in parallel with state shellfish toxicity testing during the 2006 bloom season at 41 sites from April through October. Over 500,000
A. catenella
cells liter
−1
were detected at several stations, with two main pulses of cells driving cell distribution, one in June and the other in August. PSTs over the closure limit of 80 μg of PST 100 per g of shellfish tissue were detected at 26 of the 41 sites. Comparison of cell numbers and PST data shows that shellfish toxicity is preceded by an increase in
A. catenella
cells in 71% of cases. However, cells were also observed in the absence of PSTs in shellfish, highlighting the complex relationship between
A. catenella
and the resulting shellfish toxicity. These data provide important information on the dynamics of
A. catenella
cells in the Puget Sound and are a first step toward assessing the utility of plankton monitoring to augment shellfish toxicity testing in this system.
The Transcription Factor StuA Regulates Central Carbon Metabolism, Mycotoxin Production, and Effector Gene Expression in the Wheat Pathogen Stagonospora nodorum
Authors: IpCho Simon V. S. , Tan Kar-Chun , Koh Geraldine , Gummer Joel , Oliver Richard P. , Trengove Robert D. , Solomon Peter S.
Published: May 2010

The
Stagonospora nodorum
StuA transcription factor gene
SnStuA
was identified by homology searching in the genome of the wheat pathogen
Stagonospora nodorum
. Gene expression analysis revealed that
SnStuA
transcript abundance increased throughout infection and
in vitro
growth to peak during sporulation. To investigate its role, the gene was deleted by homologous recombination. The growth of the resulting mutants was retarded on glucose compared to the wild-type growth, and the mutants also failed to sporulate. Glutamate as a sole carbon source restored the growth rate defect observed on glucose, although sporulation remained impaired. The
SnstuA
strains were essentially nonpathogenic, with only minor growth observed around the point of inoculation. The role of
SnstuA
was investigated using metabolomics, which revealed that this gene's product played a key role in regulating central carbon metabolism, with glycolysis, the TCA cycle, and amino acid synthesis all affected in the mutants. SnStuA was also found to positively regulate the synthesis of the mycotoxin alternariol. Gene expression studies on the recently identified effectors in
Stagonospora nodorum
found that SnStuA was a positive regulator of
SnTox3
but was not required for the expression of
ToxA
. This study has uncovered a multitude of novel regulatory targets of
SnStuA
and has highlighted the critical role of this gene product in the pathogenicity of
Stagonospora nodorum
.
ATP-Citrate Lyase Is Required for Production of Cytosolic Acetyl Coenzyme A and Development in Aspergillus nidulans
Authors: Hynes Michael J. , Murray Sandra L.
Published: May 2010

Acetyl coenzyme A (CoA) is a central metabolite in carbon and energy metabolism and in the biosynthesis of cellular molecules. A source of cytoplasmic acetyl-CoA is essential for the production of fatty acids and sterols and for protein acetylation, including histone acetylation in the nucleus. In
Saccharomyces cerevisiae
and
Candida albicans
acetyl-CoA is produced from acetate by cytoplasmic acetyl-CoA synthetase, while in plants and animals acetyl-CoA is derived from citrate via ATP-citrate lyase. In the filamentous ascomycete
Aspergillus nidulans
, tandem divergently transcribed genes (
aclA
and
aclB
) encode the subunits of ATP-citrate lyase, and we have deleted these genes. Growth is greatly diminished on carbon sources that do not result in cytoplasmic acetyl-CoA, such as glucose and proline, while growth is not affected on carbon sources that result in the production of cytoplasmic acetyl-CoA, such as acetate and ethanol. Addition of acetate restores growth on glucose or proline, and this is dependent on
facA
, which encodes cytoplasmic acetyl-CoA synthetase, but not on the regulatory gene
facB
. Transcription of
aclA
and
aclB
is repressed by growth on acetate or ethanol. Loss of ATP-citrate lyase results in severe developmental effects, with the production of asexual spores (conidia) being greatly reduced and a complete absence of sexual development. This is in contrast to
Sordaria macrospora
, in which fruiting body formation is initiated but maturation is defective in an ATP-citrate lyase mutant. Addition of acetate does not repair these defects, indicating a specific requirement for high levels of cytoplasmic acetyl-CoA during differentiation. Complementation in heterokaryons between
aclA
and
aclB
deletions for all phenotypes indicates that the tandem gene arrangement is not essential.
The Conjugation-Specific Die5 Protein Is Required for Development of the Somatic Nucleus in both Paramecium and Tetrahymena
Authors: Matsuda Atsushi , Shieh Annie Wan-Yi , Chalker Douglas L. , Forney James D.
Published: May 2010

Development in ciliated protozoa involves extensive genome reorganization within differentiating macronuclei, which shapes the somatic genome of the next vegetative generation. Major events of macronuclear differentiation include excision of internal eliminated sequences (IESs), chromosome fragmentation, and genome amplification. Proteins required for these events include those with homology throughout eukaryotes as well as proteins apparently unique to ciliates. In this study, we identified the ciliate-specific
D
efective in
I
ES
E
xcision 5 (
DIE5
) genes of
Paramecium tetraurelia
(
PtDIE5
) and
Tetrahymena thermophila
(
TtDIE5
) as orthologs that encode nuclear proteins expressed exclusively during development. Abrogation of PtDie5 protein (PtDie5p) function by RNA interference (RNAi)-mediated silencing or TtDie5p by gene disruption resulted in the failure of developing macronuclei to differentiate into new somatic nuclei.
Tetrahymena
Δ
DIE5
cells arrested late in development and failed to complete genome amplification, whereas RNAi-treated
Paramecium
cells highly amplified new macronuclear DNA before the failure in differentiation, findings that highlight clear differences in the biology of these distantly related species. Nevertheless, IES excision and chromosome fragmentation failed to occur in either ciliate, which strongly supports that Die5p is a critical player in these processes. In
Tetrahymena
, loss of zygotic expression during development was sufficient to block nuclear differentiation. This observation, together with the finding that knockdown of Die5p in
Paramecium
still allows genome amplification, indicates that this protein acts late in macronuclear development. Even though DNA rearrangements in these two ciliates look to be quite distinct, analysis of
DIE5
establishes the action of a conserved mechanism within the genome reorganization pathway.
Structure-Activity Analysis of thePseudomonasQuinolone Signal Molecule
Authors: Hodgkinson James , Bowden Steven D. , Galloway Warren R. J. D. , Spring David R. , Welch Martin
Published: May 2010

We synthesized a range of PQS (Pseudomonasquinolone signal; 2-heptyl-3-hydroxy-4(1H)-quinolone) analogues and tested them for their ability to stimulate MvfR-dependentpqsAtranscription, MvfR-independent pyoverdine production, and membrane vesicle production. The structure-activity profile of the PQS analogues was different for each of these phenotypes. Certain inactive PQS analogues were also found to strongly synergize PQS-dependent pyoverdine production.
Comparative Analysis of Sequence Periodicity among Prokaryotic Genomes Points to Differences in Nucleoid Structure and a Relationship to Gene Expression
Authors: Mrázek Jan
Published: May 2010

Regular spacing of short runs of A or T nucleotides in DNA sequences with a period close to the helical period of the DNA double helix has been associated with intrinsic DNA bending and nucleosome positioning in eukaryotes. Analogous periodic signals were also observed in prokaryotic genomes. While the exact role of this periodicity in prokaryotes is not known, it has been proposed to facilitate the DNA packaging in the prokaryotic nucleoid and/or to promote negative or positive supercoiling. We developed a methodology for assessments of intragenomic heterogeneity of these periodic patterns and applied it in analysis of 1,025 prokaryotic chromosomes. This technique allows more detailed analysis of sequence periodicity than previous methods where sequence periodicity was assessed in an integral form across the whole chromosome. We found that most genomes have the periodic signal confined to several chromosomal segments while most of the chromosome lacks a strong sequence periodicity. Moreover, there are significant differences among different prokaryotes in both the intensity and persistency of sequence periodicity related to DNA curvature. We proffer that the prokaryotic nucleoid consists of relatively rigid sections stabilized by short intrinsically bent DNA segments and characterized by locally strong periodic patterns alternating with regions featuring a weak periodic signal, which presumably permits higher structural flexibility. This model applies to most bacteria and archaea. In genomes with an exceptionally persistent periodic signal, highly expressed genes tend to concentrate in aperiodic sections, suggesting that structural heterogeneity of the nucleoid is related to local differences in transcriptional activity.
Regulation of High-Affinity Iron Acquisition Homologues in the Tsetse Fly SymbiontSodalis glossinidius
Authors: Runyen-Janecky Laura J. , Brown Alexandria N. , Ott Brittany , Tujuba Haddis G. , Rio Rita V. M.
Published: May 2010

Sodalis glossinidiusis a facultative intracellular bacterium that is a secondary symbiont of the tsetse fly (Diptera: Glossinidae). Since studies with other facultative intracellular bacteria have shown that high-affinity iron acquisition genes are upregulatedin vivo, we investigated the regulation of severalSodalisgenes that encode putative iron acquisition systems. These genes, SG1538 (hemT) and SG1516 (sitA), are homologous to genes encoding periplasmic heme and iron/manganese transporters, respectively.hemTpromoter- andsitApromoter-gfpfusions were constructed, and in bothEscherichia coliandSodalisbackgrounds, expression levels of these fusions were higher when the bacteria were grown in iron-limiting media than when the bacteria were grown in iron-replete media. TheSodalispromoters were tested for iron regulation in anE. colistrain that lacks thefurgene, which encodes the iron-responsive transcriptional repressor Fur. Expression of the promoter-gfpfusions in theE. coli furmutant was constitutively high in both iron-replete and iron-deplete media, and addition of eitherShigella flexneri furorSodalis furto a plasmid restored normal regulation. ASodalis furmutant was constructed by intron mutagenesis, and semiquantitative reverse transcription-PCR (RT-PCR) showed that iron repression ofsitAexpression was also abolished in this strain.In vivoexpression analysis showed thathemTandsitAare expressed whenSodalisis within tsetse fly hosts, suggesting a biological role for these genes whenSodalisis within the tsetse fly.
Variation inStreptococcus pyogenesNAD+Glycohydrolase Is Associated with Tissue Tropism
Authors: Riddle David J. , Bessen Debra E. , Caparon Michael G.
Published: May 2010

Streptococcus pyogenesis an important pathogen that causes a variety of diseases. The most common infections involve the throat (pharyngitis) or skin (impetigo); however, the factors that determine tissue tropism and severity are incompletely understood. TheS. pyogenesNAD+glycohydrolase (SPN) is a virulence factor that has been implicated in contributing to the pathogenesis of severe infections. However, the role of SPN in determining the bacterium's tissue tropism has not been evaluated. In this report, we examine the sequences ofspnand its endogenous inhibitorifsfrom a worldwide collection ofS. pyogenesstrains. Analysis of average pairwise nucleotide diversity, average number of nucleotide differences, and ratio of nonsynonymous to synonymous substitutions revealed significant diversity inspnandifs. Application of established models of molecular evolution shows that SPN is evolving under positive selection and diverging into NAD+glycohydrolase (NADase)-active and -inactive subtypes. Additionally, the NADase-inactive SPN subtypes maintain the characteristics of a functional gene whileifsbecomes a pseudogene. Thus, NADase-inactive SPN continues to evolve under functional constraint. Furthermore, NADase activity did not correlate with invasive disease in our collection but was associated with tissue tropism. The ability to cause infection at both the pharynx and the skin (“generalist” strains) is correlated with NADase-active SPN, while the preference for causing infection at either the throat or the skin (“specialist” strains) is associated with NADase-inactive SPN. These findings suggest that SPN has a NADase-independent function and prompt a reevaluation of the role of SPN in streptococcal pathogenesis.
ThePseudomonas aeruginosaVfr Regulator Controls Global Virulence Factor Expression through Cyclic AMP-Dependent and -Independent Mechanisms
Authors: Fuchs Erin L. , Brutinel Evan D. , Jones Adriana K. , Fulcher Nanette B. , Urbanowski Mark L. , Yahr Timothy L. , Wolfgang Matthew C.
Published: May 2010

Vfr is a global regulator of virulence factor expression in the human pathogenPseudomonas aeruginosa. Although indirect evidence suggests that Vfr activity is controlled by cyclic AMP (cAMP), it has been hypothesized that the putative cAMP binding pocket of Vfr may accommodate additional cyclic nucleotides. In this study, we used two different approaches to generate apo-Vfr and examined its ability to bind a representative set of virulence gene promoters in the absence and presence of different allosteric effectors. Of the cyclic nucleotides tested, only cAMP was able to restore DNA binding activity to apo-Vfr. In contrast, cGMP was capable of inhibiting cAMP-Vfr DNA binding. Further, we demonstrate thatvfrexpression is autoregulated and cAMP dependent and involves Vfr binding to a previously unidentified site within thevfrpromoter region. Using a combination ofin vitroandin vivoapproaches, we show that cAMP is required for Vfr-dependent regulation of a specific subset of virulence genes. In contrast, we discovered that Vfr controls expression of thelasRpromoter in a cAMP-independent manner. In summary, our data support a model in which Vfr controls virulence gene expression by distinct (cAMP-dependent and -independent) mechanisms, which may allowP. aeruginosato fine-tune its virulence program in response to specific host cues or environments.
The LysR-Type Transcriptional Regulator QseD Alters Type Three Secretion in Enterohemorrhagic
Escherichia coli
and Motility in K-12
Escherichia coli
Authors: Habdas Benjamin J. , Smart Jennifer , Kaper James B. , Sperandio Vanessa
Published: May 2010

Enterohemorrhagic
Escherichia coli
(EHEC) O157:H7 responds to the host-produced epinephrine and norepinephrine, and bacterially produced autoinducer 3 (AI-3), through two-component systems. Further integration of multiple regulatory signaling networks, involving regulators such as the LysR-type transcriptional regulator (LTTR) QseA, promotes effective regulation of virulence factors. These include the production of flagella, a phage-encoded Shiga toxin, and genes within the locus of enterocyte effacement (LEE) responsible for attaching and effacing (AE) lesion formation. Here, we describe a new member of this signaling cascade, an LTTR heretofore renamed QseD (quorum-sensing
E. coli
regulator D). QseD is present in all enterobacteria but exists almost exclusively in O157:H7 isolates as a helix-turn-helix (HTH) truncated isoform. This “short” isoform (sQseD) is still able to regulate gene expression through a different mechanism than the full-length K-12
E. coli
“long” QseD isoform (lQseD). The EHEC Δ
qseD
mutant exhibits increased expression of all LEE operons and deregulation of AE lesion formation. The loss of
qseD
in EHEC does not affect motility, but the K-12 Δ
qseD
mutant is hypermotile. While the lQseD directly binds to the
ler
promoter, encoding the LEE master regulator, to repress LEE transcription, the sQseD isoform does not. LTTRs bind to DNA as tetramers, and these data suggest that sQseD regulates
ler
by forming heterotetramers with another LTTR. The LTTRs known to regulate LEE transcription, QseA and LrhA, do not interact with sQseD, suggesting that sQseD acts as a dominant-negative partner with a yet-unidentified LTTR.
AN OPTIMAL MARKET ENTRY/EXIT EVALUATION MODEL WITH PARTIAL FINANCING FUNDS
Authors: LIN TYRONE T. , KO CHUAN-CHUAN , LIU CHIEN-YU
Published: May 2010

The paper mainly aims to introduce the real options approach to construct an evaluation model for the firm value under partial financing funds. The paper examines that production volume follows the geometric Brownian motion and considers that both the market entry of investment cost and the market exit of withdrawal cost match the linear function with production volume. Then the paper evaluates the potential firm value before market entry, the operational value with the firm's operating, and the market exit value with the firm's stopping to operate so as to assess the whole firm value, shareholder value, and bondholder value hereafter. The results show that different debt ratios will affect the firm's investment decision. The paper figures out the optimal decision-making based on the maximum profit of shareholders or the maximum profit of shareholders-and-bondholders. The factor is finance leverage; although interest expenses are tax deductible, an overly high leverage may trigger agency costs for a firm, which will offset the tax shields associated with leverage. Therefore, a firm should not leverage too much. Furthermore, the paper constructs an innovative evaluation model in a dynamic-financing environment in order to provide the management team with a decision-making mechanism for their decisions in market entry or market exit in a timely manner in the face of uncontrollable exogenous variables.
The importance of elastin to aortic development in mice
Authors: Wagenseil Jessica E. , Ciliberto Christopher H. , Knutsen Russell H. , Levy Marilyn A. , Kovacs Attila , Mecham Robert P.
Published: May 2010

Elastin is an essential component of vertebrate arteries that provides elasticity and stores energy during the cardiac cycle. Elastin production in the arterial wall begins midgestation but increases rapidly during the last third of human and mouse development, just as blood pressure and cardiac output increase sharply. The aim of this study is to characterize the structure, hemodynamics, and mechanics of developing arteries with reduced elastin levels and determine the critical time period where elastin is required in the vertebrate cardiovascular system. Mice that lack elastin ( Eln−/−) or have approximately one-half the normal level ( Eln+/−) show relatively normal cardiovascular development up to embryonic day (E) 18 as assessed by arterial morphology, left ventricular blood pressure, and cardiac function. Previous work showed that just a few days later, at birth, Eln−/−mice die with high blood pressure and tortuous, stenotic arteries. During this period from E18 to birth, Eln+/−mice add extra layers of smooth muscle cells to the vessel wall and have a mean blood pressure 25% higher than wild-type animals. These findings demonstrate that elastin is only necessary for normal cardiovascular structure and function in mice starting in the last few days of fetal development. The large increases in blood pressure during this period may push hemodynamic forces over a critical threshold where elastin becomes required for cardiovascular function. Understanding the interplay between elastin amounts and hemodynamic forces in developing vessels will help design treatments for human elastinopathies and optimize protocols for tissue engineering.
NFATc3 contributes to intermittent hypoxia-induced arterial remodeling in mice
Authors: de Frutos Sergio , Caldwell Elizabeth , Nitta Carlos H. , Kanagy Nancy L. , Wang Jian , Wang Wei , Walker Mary K. , Gonzalez Bosc Laura V.
Published: May 2010

Sleep apnea (SA) is defined as intermittent respiratory arrest during sleep and affects up to 20% of the adult population. SA is also associated with an increased incidence of hypertension and peripheral vascular disease. Exposing rodents to intermittent hypoxia during sleep mimics the cyclical hypoxia/normoxia of SA. We have previously shown that in mice and rats intermittent hypoxia induces ET-1 upregulation and systemic hypertension. Furthermore, intermittent hypoxia (IH) in mice increases nuclear factor of activated T cells isoform 3 (NFATc3) transcriptional activity in aorta and mesenteric arteries, whereas the calcineurin/NFAT inhibitor cyclosporin A prevents IH-induced hypertension. More importantly, NFATc3 knockout (KO) mice do not develop IH-induced hypertension. The goals of this study were to determine the role of NFATc3 in IH-induced arterial remodeling and whether IH-induced NFATc3 activation is mediated by ET-1. Oral administration of both a dual (bosentan) and a selective endothelin receptor type A antagonist (PD155080) during 2 days of IH exposure attenuated NFAT activation in aorta and mesenteric arteries. Rho kinase inhibition with fasudil also prevented IH-induced NFAT activation. Mesenteric artery cross-sectional wall thickness was increased by IH in wild-type (WT) and vehicle-treated mice but not in bosentan-treated and NFATc3 KO mice. The arterial remodeling in mesenteric arteries after IH was characterized by increased expression of the hypertrophic NFATc3 target smooth muscle-α-actin in WT but not in KO mice. These results indicate that ET-1 is an upstream activator of NFATc3 during intermittent hypoxia, contributing to the resultant hypertension and increased wall thickness.