bluuebunny/crossref_metadata_2025_split huggingface dataset:
Marathon of eponyms: 20 Treacher Collins syndrome
Authors: Scully C , Langdon J , Evans J 
Published: July 2011

Oral Diseases (2009) 17, 619–620The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009: 15; 185). The use of eponyms in diseases of the head and neck is found mainly in specialties dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology, oral and maxillofacial radiology and oral and maxillofacial surgery) and particularly by hospital‐centred practitioners. This series has selected some of the more recognized relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This document summarizes data about Treacher Collins syndrome.
Unique predisposing factors for male urinary tract infections
Authors: Hogan LaMicha , Young Cathy , Gabbert Wrennah , Armstrong Myrna L. 
Published: July 2011

AbstractPurpose: While naturally occurring male host defense mechanisms prevent many urinary tract infections (UTI), this article describes two purposeful forms of urethral play (UP) that could be unique predisposing factors to increased UTI susceptibility.Data sources: Medical literature has documented unconventional penile and urethral activities since the mid 1700s. In a recent web‐based study, Rinard et al. report 74 comments from national and international respondents performing UP: various websites also validate UP practice.Conclusions: Respondents reported inserting liquids and foreign objects into the urethra. Inserted liquids included water, hot candle wax, baby oil, after‐shave lotions, and dental gel. Foreign objects frequently mentioned were the insertion of smooth stainless steel surgical dilators often used in surgical urological procedures; the respondents and the websites call this “urethral sounding.” These practices were used to “aid erections and sexual experimentation, enlarge the urethra, and stimulate their partner.” Other respondents discussed catheter insertion. Other objects such as cotton‐tipped swabs, spoons, and pencils, were also inserted. UTIs have been reported as a result of UP.Implications for practice: Nurse practitioners' knowledge of these seemingly unconventional urethral activities requires a thorough assessment and history for pediatric and adult males presenting with new, recurrent, or unresolved UTI symptoms, as well as applicable health education.
Measuring the wobble of radiation field centers during gantry rotation and collimator movement on a linear accelerator
Authors: Du Weiliang , Gao Song 
Published: July 2011

Purpose:The isocenter accuracy of a linear accelerator is often assessed with star‐shot films. This approach is limited in its ability to quantify three dimensional wobble of radiation field centers (RFCs). The authors report a Winston–Lutz based method to measure the 3D wobble of RFCs during gantry rotation, collimator rotation, and collimator field size change.Methods:A stationary ball‐bearing phantom was imaged using multileaf collimator‐shaped radiation fields at various gantry angles, collimator angles, and field sizes. The center of the ball‐bearing served as a reference point, to which all RFCs were localized using a computer algorithm with subpixel accuracy. Then, the gantry rotation isocenter and the collimator rotation axis were derived from the coordinates of these RFCs. Finally, the deviation or wobble of the individual RFC from the derived isocenter or rotation axis was quantified.Results:The results showed that the RFCs were stable as the field size of the multileaf collimator was varied. The wobble of RFCs depended on the gantry angle and the collimator angle and was reproducible, indicating that the mechanical imperfections of the linac were mostly systematic and quantifiable. It was found that the 3D wobble of RFCs during gantry rotation was reduced after compensating for a constant misalignment of the multileaf collimator.Conclusions:The 3D wobble of RFCs can be measured with submillimeter precision using the proposed method. This method provides a useful tool for checking and adjusting the radiation isocenter tightness of a linac.
Imaging and localizing fish and marine mammals with acoustics.
Authors: Ratilal Purnima , Tran Duong , Gong Roger , Reed David , Chauhan Hari , Makris Nicholas 
Published: July 2011

During the 2006 ocean acoustic waveguide remote sensing (OAWRS) experiment in the Gulf of Maine, large shoals of Atlantic herring were instantaneously imaged in the frequency range from 300 to 1200 Hz. Simultaneously, several thousand instances of marine mammal vocalizations were passively recorded on a high resolution towed horizontal receiving array. A vast majority of the vocalizations were from humback whales in the 300–600 Hz frequency range. Vocalizations from other marine mammals species ranging from 40 Hz to over 3 kHz were also recorded. Various approaches are employed to localize and track the whales both passively and actively. The bearing of calling whales can be found by beamforming their vocalizations measured on the receiving array. An efficient and robust matched filter is designed to enhance the signal-to-noise ratio of the whale vocalizations. The array invariant method [Lee and Makris, J. Acoust. Soc. Am. (2006)] is then applied for instantaneous whale range estimation. The array invariant approach has been verified theoretically with modeled complex nonlinear whale vocalizations propagated long ranges exceeding 50 km in a range-dependent ocean waveguide. The whale range estimates obtained with the array invariance technique are verified by hyperbolic localization of the vocalization signals measured by the moving receiver array along a given track.
Comparative13C Metabolic Flux Analysis of Pyruvate Dehydrogenase Complex-Deficient,l-Valine-Producing Corynebacterium glutamicum
Authors: Bartek Tobias , Blombach Bastian , Lang Siegmund , Eikmanns Bernhard J. , Wiechert Wolfgang , Oldiges Marco , Nöh Katharina , Noack Stephan 
Published: July 2011

ABSTRACTl-Valine can be formed successfully usingC. glutamicumstrains missing an active pyruvate dehydrogenase enzyme complex (PDHC). Wild-typeC. glutamicumand four PDHC-deficient strains were compared by13C metabolic flux analysis, especially focusing on the split ratio between glycolysis and the pentose phosphate pathway (PPP). Compared to the wild type, showing a carbon flux of 69% ± 14% through the PPP, a strong increase in the PPP flux was observed in PDHC-deficient strains with a maximum of 113% ± 22%. The shift in the split ratio can be explained by an increased demand of NADPH forl-valine formation. In accordance, the introduction of theEscherichia colitranshydrogenase PntAB, catalyzing the reversible conversion of NADH to NADPH, into anl-valine-producingC. glutamicumstrain caused the PPP flux to decrease to 57% ± 6%, which is below the wild-type split ratio. Hence, transhydrogenase activity offers an alternative perspective for sufficient NADPH supply, which is relevant for most amino acid production systems. Moreover, as demonstrated forl-valine, this bypass leads to a significant increase of product yield due to a concurrent reduction in carbon dioxide formation via the PPP.
Characterization of Two Distinct Glycosyl Hydrolase Family 78 α-
l
-Rhamnosidases from Pediococcus acidilactici
Authors: Michlmayr Herbert , Brandes Walter , Eder Reinhard , Schümann Christina , del Hierro Andrés M. , Kulbe Klaus D. 
Published: July 2011

ABSTRACT

α-
l
-Rhamnosidases play an important role in the hydrolysis of glycosylated aroma compounds (especially terpenes) from wine. Although several authors have demonstrated the enological importance of fungal rhamnosidases, the information on bacterial enzymes in this context is still limited. In order to fill this important gap, two putative rhamnosidase genes (
ram
and
ram2
) from
Pediococcus acidilactici
DSM 20284 were heterologously expressed, and the respective gene products were characterized. In combination with a bacterial β-glucosidase, both enzymes released the monoterpenes linalool and
cis
-linalool oxide from a muscat wine extract under ideal conditions. Additionally, Ram could release significant amounts of geraniol and citronellol/nerol. Nevertheless, the potential enological value of these enzymes is limited by the strong negative effects of acidity and ethanol on the activities of Ram and Ram2. Therefore, a direct application in winemaking seems unlikely. Although both enzymes are members of the same glycosyl hydrolase family (GH 78), our results clearly suggest the distinct functionalities of Ram and Ram2, probably representing two subclasses within GH 78: Ram could efficiently hydrolyze only the synthetic substrate
p
-nitrophenyl-α-
l
-rhamnopyranoside (
V
max
= 243 U mg
−1
). In contrast, Ram2 displayed considerable specificity toward hesperidin (
V
max
= 34 U mg
−1
) and, especially, rutinose (
V
max
= 1,200 U mg
−1
), a disaccharide composed of glucose and rhamnose. Both enzymes were unable to hydrolyze the flavanone glycoside naringin. Interestingly, both enzymes displayed indications of positive substrate cooperativity. This study presents detailed kinetic data on two novel rhamnosidases, which could be relevant for the further study of bacterial glycosidases.
D1/D2 Domain of Large-Subunit Ribosomal DNA for Differentiation of Orpinomyces spp
Authors: Dagar Sumit S. , Kumar Sanjay , Mudgil Priti , Singh Rameshwar , Puniya Anil K. 
Published: July 2011

ABSTRACT

This study presents the suitability of D1/D2 domain of large-subunit (LSU) ribosomal DNA (rDNA) for differentiation of
Orpinomyces joyonii
and
Orpinomyces intercalaris
based on PCR-restriction fragment length polymorphism (RFLP). A variation of G/T in
O. intercalaris
created an additional restriction site for AluI, which was used as an RFLP marker. The results demonstrate adequate heterogeneity in the LSU rDNA for species-level differentiation.
Localization of the Clostridium difficile Cysteine Protease Cwp84 and Insights into Its Maturation Process
Authors: ChapetónMontes Diana , Candela Thomas , Collignon Anne , Janoir Claire 
Published: July 2011

ABSTRACT

Clostridium difficile
is a nosocomial pathogen involved in antibiotic-associated diarrhea.
C. difficile
expresses a cysteine protease, Cwp84, which has been shown to degrade some proteins of the extracellular matrix and play a role in the maturation of the precursor of the S-layer proteins. We sought to analyze the localization and the maturation process of this protease. Two identifiable forms of the protease were found to be associated in the bacteria: a form of ∼80 kDa and a cleaved one of 47 kDa, identified as the mature protease. They were found mainly in the bacterial cell surface fractions and weakly in the extracellular fraction. The 80-kDa protein was noncovalently associated with the S-layer proteins, while the 47-kDa form was found to be tightly associated with the underlying cell wall. Our data supported that the anchoring of the Cwp84 47-kDa form is presumably due to a reassociation of the secreted protein. Moreover, we showed that the complete maturation of the recombinant protein Cwp84
30-803
is a sequential process beginning at the C-terminal end, followed by one or more cleavages at the N-terminal end. The processing sites of recombinant Cwp84 are likely to be residues Ser-92 and Lys-518. No proteolytic activity was detected with the mature recombinant protease Cwp84
92-518
(47 kDa). In contrast, a fragment including the propeptide (Cwp84
30-518
) displayed proteolytic activity on azocasein and fibronectin. These results showed that Cwp84 is processed essentially at the bacterial cell surface and that its different forms may display different proteolytic activities.
Pole Age Affects Cell Size and the Timing of Cell Division in Methylobacterium extorquens AM1
Authors: Bergmiller Tobias , Ackermann Martin 
Published: July 2011

ABSTRACT

A number of recent experiments at the single-cell level have shown that genetically identical bacteria that live in homogeneous environments often show a substantial degree of phenotypic variation between cells. Often, this variation is attributed to stochastic aspects of biology—the fact that many biological processes involve small numbers of molecules and are thus inherently variable. However, not all variation between cells needs to be stochastic in nature; one deterministic process that could be important for cell variability in some bacterial species is the age of the cell poles. Working with the alphaproteobacterium
Methylobacterium extorquens
, we monitored individuals in clonally growing populations over several divisions and determined the pole age, cell size, and interdivision intervals of individual cells. We observed the high levels of variation in cell size and the timing of cell division that have been reported before. A substantial fraction of this variation could be explained by each cell's pole age and the pole age of its mother: cell size increased with increasing pole age, and the interval between cell divisions decreased. A theoretical model predicted that populations governed by such processes will quickly reach a stable distribution of different age and size classes. These results show that the pole age distribution in bacterial populations can contribute substantially to cellular individuality. In addition, they raise questions about functional differences between cells of different ages and the coupling of cell division to cell size.
Regulation of the Virulence Determinant OspC by
bbd18
on Linear Plasmid lp17 of Borrelia burgdorferi
Authors: Sarkar Amit , Hayes Beth M. , Dulebohn Daniel P. , Rosa Patricia A. 
Published: July 2011

ABSTRACT

Persistent infection of a mammalian host by
Borrelia burgdorferi
, the spirochete that causes Lyme disease, requires specific downregulation of an immunogenic outer surface protein, OspC. Although OspC is an essential virulence factor needed by the spirochete to establish infection in the mammal, it represents a potent target for the host acquired immune response, and constitutive expression of OspC results in spirochete clearance. In this study, we demonstrate that a factor encoded on a linear plasmid of
B. burgdorferi
, lp17, can negatively regulate
ospC
transcription from the endogenous gene on the circular plasmid cp26 and from an
ospC
promoter-
lacZ
fusion on a shuttle vector. Furthermore, we have identified
bbd18
as the gene on lp17 that is responsible for this effect. These data identify a novel component of
ospC
regulation and provide the basis for determining the molecular mechanisms of
ospC
repression
in vivo
.
Characterization of Escherichia coli UmuC Active-Site Loops Identifies Variants That Confer UV Hypersensitivity
Authors: Hawver Lisa A. , Gillooly Caitlin A. , Beuning Penny J. 
Published: July 2011

ABSTRACT

DNA is constantly exposed to chemical and environmental mutagens, causing lesions that can stall replication. In order to deal with DNA damage and other stresses,
Escherichia coli
utilizes the SOS response, which regulates the expression of at least 57 genes, including
umuDC
. The gene products of
umuDC
, UmuC and the cleaved form of UmuD, UmuD′, form the specialized
E. coli
Y-family DNA polymerase UmuD′
2
C, or polymerase V (Pol V). Y-family DNA polymerases are characterized by their specialized ability to copy damaged DNA in a process known as translesion synthesis (TLS) and by their low fidelity on undamaged DNA templates. Y-family polymerases exhibit various specificities for different types of DNA damage. Pol V carries out TLS to bypass abasic sites and thymine-thymine dimers resulting from UV radiation. Using alanine-scanning mutagenesis, we probed the roles of two active-site loops composed of residues 31 to 38 and 50 to 54 in Pol V activity by assaying the function of single-alanine variants in UV-induced mutagenesis and for their ability to confer resistance to UV radiation. We find that mutations of the N-terminal residues of loop 1, N32, N33, and D34, confer hypersensitivity to UV radiation and to 4-nitroquinoline-
N
-oxide and significantly reduce Pol V-dependent UV-induced mutagenesis. Furthermore, mutating residues 32, 33, or 34 diminishes Pol V-dependent inhibition of recombination, suggesting that these mutations may disrupt an interaction of UmuC with RecA, which could also contribute to the UV hypersensitivity of cells expressing these variants.
Transcriptional Hierarchy of Aeromonas hydrophila Polar-Flagellum Genes
Authors: Wilhelms Markus , Molero Raquel , Shaw Jonathan G. , Tomás Juan M. , Merino Susana 
Published: July 2011

ABSTRACT

Aeromonas hydrophila
polar-flagellum class I gene transcription is σ
70
dependent, which is consistent with the fact that the
A. hydrophila
polar flagellum is constitutively expressed. In contrast to other bacteria with dual flagellar systems such as
Vibrio parahaemolyticus
, the
A. hydrophila
LafK protein does not compensate for the lack of the polar-flagellum regulator FlrA (
V. parahaemolyticus
FlaK homologue). This is consistent with the fact that the
A. hydrophila
FlrA mutation abolishes polar-flagellum formation in liquid and on solid surfaces but does not affect inducible lateral-flagellum formation. The results highlight that the polar- and lateral-flagellum interconnections and control networks are specific and that there are differences between the dual flagellar systems in
A. hydrophila
and
V. parahaemolyticus
. Furthermore, our results indicate that the
A. hydrophila
polar-flagellum transcriptional hierarchy (also in class II, III, and IV genes) shares some similarities with but has many important differences from the transcriptional hierarchies of
Vibrio cholerae
and
Pseudomonas aeruginosa
. The
A. hydrophila flhF
and
flhG
genes are essential for the assembly of a functional polar flagellum because in-frame mutants fail to swim in liquid medium and lack the polar flagellum. In
Vibrio
and
Pseudomonas flhG
disruption increases the number of polar flagella per cell, and
Pseudomonas flhF
disruption gives an aberrant placement of flagellum. Here, we propose the gene transcriptional hierarchy for the
A. hydrophila
polar flagellum.
Quorum Sensing Contributes to Natural Transformation of Vibrio cholerae in a Species-Specific Manner
Authors: Suckow Gaia , Seitz Patrick , Blokesch Melanie 
Published: July 2011

ABSTRACTAlthough it is a human pathogen,Vibrio choleraeis a regular member of aquatic habitats, such as coastal regions and estuaries. Within these environments,V. choleraeoften takes advantage of the abundance of zooplankton and their chitinous molts as a nutritious surface on which the bacteria can form biofilms. Chitin also induces the developmental program of natural competence for transformation in several species of the genusVibrio.In this study, we show thatV. choleraedoes not distinguish between species-specific and non-species-specific DNA at the level of DNA uptake. This is in contrast to what has been shown for other Gram-negative bacteria, such asNeisseria gonorrhoeaeandHaemophilus influenzae.However, species specificity with respect to natural transformation still occurs inV. cholerae. This is based on a positive correlation between quorum sensing and natural transformation. Using mutant-strain analysis, cross-feeding experiments, and synthetic cholera autoinducer-1 (CAI-1), we provide strong evidence that the species-specific signaling molecule CAI-1 plays a major role in natural competence for transformation. We suggest that CAI-1 can be considered a competence pheromone.
Characterization of anN-Acetylmuramic Acid/N-Acetylglucosamine Kinase of Clostridium acetobutylicum
Authors: Reith Jan , Berking Anne , Mayer Christoph 
Published: July 2011

ABSTRACTWe report here the cloning and characterization of a cytoplasmic kinase ofClostridium acetobutylicum, named MurK (formurein sugarkinase). The enzyme has a unique specificity for both amino sugars of the bacterial cell wall,N-acetylmuramic acid (MurNAc) andN-acetylglucosamine (GlcNAc), which are phosphorylated at the 6-hydroxyl group. Kinetic analyses revealedKmvalues of 190 and 127 μM for MurNAc and GlcNAc, respectively, and akcatvalue (65.0 s−1) that was 1.5-fold higher for the latter substrate. Neither the non-N-acetylated forms of the cell wall sugars, i.e., glucosamine and/or muramic acid, nor epimeric hexoses or 1,6-anhydro-MurNAc were substrates for the enzyme. MurK displays low overall amino acid sequence identity (24%) with human GlcNAc kinase and is the first characterized bacterial representative of the BcrAD/BadFG-like ATPase family. We propose a role of MurK in the recovery of muropeptides during cell wall rescue inC. acetobutylicum. The kinase was applied for high-sensitive detection of the amino sugars in cell wall preparations by radioactive phosphorylation.
Biochemical studies on the production of neuraminidase by environmental isolates ofVibrio choleraenon-O1 from Bulgaria
Authors: Eneva Rumyana , Engibarov Stephan , Strateva Tanya , Abrashev Radoslav , Abrashev Ignat 
Published: July 2011

Neuraminidase is a key factor in the infectious process of many viruses and pathogenic bacteria. The neuraminidase enzyme secreted by the etiological agent of cholera — Vibrio cholerae О1 — is well studied in contrast with the one produced by non-O1/non-O139 V. cholerae. Environmental non-O1/non-O139 V. cholerae isolates from Bulgaria were screened for production of neuraminidase. The presence of the neuraminidase gene nanH was detected in 18.5% of the strains. Тhe strain showing highest activity (30 U/mL), V. cholerae non-O1/13, was used to investigate the enzyme production in several media and at different aeration conditions. The highest production of extracellular neuraminidase was observed under microaerophilic conditions, which is possibly related to its role in the infection of intestine epithelium, where the oxygen content is low. On the other hand, this is another advantage of the microbe in such microaerophilic environments as sediments and lake mud. The highest production of intracellular neuraminidase was observed at anaerobic conditions. The ratio of extracellular to intracellular neuraminidase production in V. cholerae was investigated. The temperature optimum of the enzyme was determined to be 50 °C and the pH optimum to be 5.6–5.8.