bluuebunny/crossref_metadata_2025 huggingface dataset:
Heterosis in lucerne testcrosses with Medicago arborea introgressions and Omani landraces and their performance in synthetics
Authors: Irwin J. A. G. , Armour D. J. , Pepper P. M. , Lowe K. F.
Published: June 2010

Testcrosses were made with novel sources of lucerne germplasm. These were evaluated in the field in a subtropical environment to identify the lines which produced the highest yielding hybrids as a guide to future breeding efforts. The novel sources were derivatives of Medicago sativa × M. arborea partial (asymmetric) hybrids (termed sac) and very highly winter-active Omani landraces of M. sativa. As testers, 2 lines were used; a Colletotrichum trifolii race 2 resistant selection from the group 9 Australian-bred and adapted cultivar PacL 901 (selection hereafter termed 901) and the Omani landrace, Oman 2, collected at 17°N latitude, from Salalah, Oman. In the row experiment, substantial and significantly positive tester parent heterosis for overall yield (sum of 13 harvests) was observed in all of the sac × Oman 2 testcrosses, with the mean performance of the 11 testcrosses (1839 g/m row) significantly (P < 0.05) exceeding the mean performance of the sac × 901 testcrosses (1703 g/m row) evaluated. Where 901 was used as the tester, heterosis values relative to the tester for the same sac lines were negative for all testcrosses with 8 of the testcrosses being significantly negative. For the Omani landrace × 901 testcrosses, positive and negative heterosis values for total yield relative to the tester were observed, but none were significantly different from zero. The 901 tester yielded significantly (P < 0.05) more per se than the Oman 2 tester (1956 v. 1470 g/m row), although in an adjacent sward experiment Oman 2 yielded comparably to most of the standard commercial cultivars. The potential of the novel germplasm in the subtropics was verified in sward experiments with synthetics and/or strain crosses with yield increases of up to 42% over the benchmark synthetic Sequel. Further improvements can be expected following selection for disease and pest resistance within the lines and in the case of Oman 2 and sac, converging to maximise complementary gene action.
The ubiquitin ligase Fbxw7 controls adipocyte differentiation by targeting C/EBPα for degradation
Authors: Bengoechea-Alonso Maria T. , Ericsson Johan
Published: June 2010

Adipose tissue controls body lipid and energy metabolism, as well as food intake, and abnormalities in adipose function play a central role in diseases such as obesity and type-2 diabetes. Adipocyte differentiation is controlled by a transcriptional cascade involving PPARγ and members of the C/EBP family of transcription factors. Here, we demonstrate that C/EBPα is targeted for degradation by the ubiquitin ligase Fbxw7 in a phosphorylation-dependent manner. Importantly, inactivation of Fbxw7 is sufficient to convert mouse preadipocytes into mature adipocytes in a manner dependent on C/EBPα. In addition, inactivation of Fbxw7 promotes adipocyte differentiation of human adult stem cells. Taken together, our results suggest that Fbxw7 is a negative regulator of adipogenesis by targeting C/EBPα for degradation. This notion is supported by the observation that the expression of Fbxw7 is down-regulated during adipocyte differentiation, resulting in the accumulation of proadipogenic proteins such as C/EBPα. Thus, Fbxw7 could be an important regulator of energy and lipid metabolism.
Central role of the RNA polymerase trigger loop in intrinsic RNA hydrolysis
Authors: Yuzenkova Yulia , Zenkin Nikolay
Published: June 2010

The active center of RNA polymerase can hydrolyze phosphodiester bonds in nascent RNA, a reaction thought to be important for proofreading of transcription. The reaction proceeds via a general two Mg
2+
mechanism and is assisted by the 3′ end nucleotide of the transcript. Here, by using
Thermus aquaticus
RNA polymerase, we show that the reaction also requires the flexible domain of the active center, the trigger loop (TL). We show that the invariant histidine (β′ His1242) of the TL is essential for hydrolysis/proofreading and participates in the reaction in two distinct ways: by positioning the 3′ end nucleotide of the transcript that assists catalysis and/or by directly participating in the reaction as a general base. We also show that participation of the β′ His1242 of the TL in phosphodiester bond hydrolysis does not depend on the extent of elongation complex backtracking. We obtained similar results with
Escherichia coli
RNA polymerase, indicating that the function of the TL in phosphodiester bond hydrolysis is conserved among bacteria.
A mouse model of chondrocyte-specific somatic mutation reveals a role for
Ext1
loss of heterozygosity in multiple hereditary exostoses
Authors: Matsumoto Kazu , Irie Fumitoshi , Mackem Susan , Yamaguchi Yu
Published: June 2010

Multiple hereditary exostoses (MHE) is one of the most common skeletal dysplasias, exhibiting the formation of multiple cartilage-capped bony protrusions (osteochondroma) and characteristic bone deformities. Individuals with MHE carry heterozygous loss-of-function mutations in
Ext1
or
Ext2
, genes which together encode an enzyme essential for heparan sulfate synthesis. Despite the identification of causative genes, the pathogenesis of MHE remains unclear, especially with regard to whether osteochondroma results from loss of heterozygosity of the
Ext
genes. Hampering elucidation of the pathogenic mechanism of MHE, both

Ext1
+/−

and

Ext2
+/−

heterozygous mutant mice, which mimic the genetic status of human MHE, are highly resistant to osteochondroma formation, especially in long bones. To address these issues, we created a mouse model in which
Ext1
is stochastically inactivated in a chondrocyte-specific manner. We show that these mice develop multiple osteochondromas and characteristic bone deformities in a pattern and a frequency that are almost identical to those of human MHE, suggesting a role for
Ext1
LOH in MHE. Surprisingly, however, genotyping and fate mapping analyses reveal that chondrocytes constituting osteochondromas are mixtures of mutant and wild-type cells. Moreover, osteochondromas do not possess many typical neoplastic properties. Together, our results suggest that inactivation of
Ext1
in a small fraction of chondrocytes is sufficient for the development of osteochondromas and other skeletal defects associated with MHE. Because the observed osteochondromas in our mouse model do not arise from clonal growth of chondrocytes, they cannot be considered true neoplasms.
A human surfactant peptide-elastase inhibitor construct as a treatment for emphysema
Authors: Guarnieri Frank , Spencer Jean L. , Lucey Edgar C. , Nugent Matthew A. , Stone Phillip J.
Published: June 2010

Two million Americans suffer from pulmonary emphysema, costing $2.5 billion/year and contributing to 100,000 deaths/year. Emphysema is thought to result from an imbalance between elastase and endogenous inhibitors of elastase, leading to tissue destruction and a loss of alveoli. Decades of research have still not resulted in an effective treatment other than stopping cigarette smoking, a highly addictive behavior. On the basis of our previous work, we hypothesize that small molecule inhibitors of human neutrophil elastase are ineffective because of rapid clearance from the lungs. To develop a long-acting elastase inhibitor with a lung pharmacodynamic profile that has minimal immunogenicity, we covalently linked an elastase inhibitor, similar to a trifluoro inhibitor that was used in clinical trials, to a 25-amino-acid fragment of human surfactant peptide B. We used this construct to prevent human neutrophil elastase-induced emphysema in a rodent model. The elastase inhibitor alone, although in a 70-fold molar excess to elastase in a mixture with <0.6% residual elastase activity, provided no protection from elastase-induced emphysema. Covalently combining an endogenous peptide from the target organ with a synthetic small molecule inhibitor is a unique way of endowing an active compound with the pharmacodynamic profile needed to create in vivo efficacy.
A common red algal origin of the apicomplexan, dinoflagellate, and heterokont plastids
Authors: Janouškovec Jan , Horák Aleš , Oborník Miroslav , Lukeš Julius , Keeling Patrick J.
Published: June 2010

The discovery of a nonphotosynthetic plastid in malaria and other apicomplexan parasites has sparked a contentious debate about its evolutionary origin. Molecular data have led to conflicting conclusions supporting either its green algal origin or red algal origin, perhaps in common with the plastid of related dinoflagellates. This distinction is critical to our understanding of apicomplexan evolution and the evolutionary history of endosymbiosis and photosynthesis; however, the two plastids are nearly impossible to compare due to their nonoverlapping information content. Here we describe the complete plastid genome sequences and plastid-associated data from two independent photosynthetic lineages represented by
Chromera velia
and an undescribed alga CCMP3155 that we show are closely related to apicomplexans. These plastids contain a suite of features retained in either apicomplexan (four plastid membranes, the ribosomal superoperon, conserved gene order) or dinoflagellate plastids (form II Rubisco acquired by horizontal transfer, transcript polyuridylylation, thylakoids stacked in triplets) and encode a full collective complement of their reduced gene sets. Together with whole plastid genome phylogenies, these characteristics provide multiple lines of evidence that the extant plastids of apicomplexans and dinoflagellates were inherited by linear descent from a common red algal endosymbiont. Our phylogenetic analyses also support their close relationship to plastids of heterokont algae, indicating they all derive from the same endosymbiosis. Altogether, these findings support a relatively simple path of linear descent for the evolution of photosynthesis in a large proportion of algae and emphasize plastid loss in several lineages (e.g., ciliates,
Cryptosporidium
, and
Phytophthora)
.
Mouse MOV10L1 associates with Piwi proteins and is an essential component of the Piwi-interacting RNA (piRNA) pathway
Authors: Zheng Ke , Xiol Jordi , Reuter Michael , Eckardt Sigrid , Leu N. Adrian , McLaughlin K. John , Stark Alexander , Sachidanandam Ravi , Pillai Ramesh S. , Wang Peijing Jeremy
Published: June 2010

Piwi-interacting RNAs (piRNAs) are essential for silencing of transposable elements in the germline, but their biogenesis is poorly understood. Here we demonstrate that MOV10L1, a germ cell–specific putative RNA helicase, is associated with Piwi proteins. Genetic disruption of the MOV10L1 RNA helicase domain in mice renders both MILI and MIWI2 devoid of piRNAs. Absence of a functional piRNA pathway in
Mov10l1
mutant testes causes loss of DNA methylation and subsequent derepression of retrotransposons in germ cells. The
Mov10l1
mutant males are sterile owing to complete meiotic arrest. This mouse mutant expresses Piwi proteins but lacks piRNAs, suggesting that MOV10L1 is required for piRNA biogenesis and/or loading to Piwi proteins.
Expansion of human NK-22 cells with IL-7, IL-2, and IL-1β reveals intrinsic functional plasticity
Authors: Cella Marina , Otero Karel , Colonna Marco
Published: June 2010

Natural killer-22 (NK-22) cells are a human NK cell subset situated in mucosal-associated lymphoid tissues that specialize in IL-22 secretion in response to IL-23. Here we investigated the cytokine requirements for NK-22 cell expansion. IL-7 maintained the sur-vival of NK-22 cells and IL-22 production in response to IL-23 but was insufficient to induce robust expansion. Proliferation of NK-22 cells was increased markedly by adding either IL-1β or IL-2 to IL-7 and was even stronger in the presence of IL-1β plus IL-2. In contrast to IL-7, continuous culture in IL-1β and IL-2 modified NK-22 cytokine profiles. IL-1β promoted constitutive IL-22 secretion rather than acute IL-22 production in response to IL-23 and induced IL-17 in some cells. IL-2 reduced secretion of IL-22 and IL-17, increasing production of IFN-γ and leukemia inhibitory factor. Functional deviation toward IFN-γ production also was induced by continuous culture in IL-23. These results demonstrate the functional plasticity of NK-22 cells, which may allow flexible responses to different pathogens. Finally, we found that NK-22 cells released the B-cell survival factor, B-cell activating factor belonging to the TNF family (BAFF), suggesting a potential role of NK-22 cells in promoting B-cell–mediated mucosal immunity.
Puzzling inefficiency of H5N1 influenza vaccines in Egyptian poultry
Authors: Kim Jeong-Ki , Kayali Ghazi , Walker David , Forrest Heather L. , Ellebedy Ali H. , Griffin Yolanda S. , Rubrum Adam , Bahgat Mahmoud M. , Kutkat M. A. , Ali M. A. A. , Aldridge Jerry R. , Negovetich Nicholas J. , Krauss Scott , Webby Richard J. , Webster Robert G.
Published: June 2010

In Egypt, efforts to control highly pathogenic H5N1 avian influenza virus in poultry and in humans have failed despite increased biosecurity, quarantine, and vaccination at poultry farms. The ongoing circulation of HP H5N1 avian influenza in Egypt has caused >100 human infections and remains an unresolved threat to veterinary and public health. Here, we describe that the failure of commercially available H5 poultry vaccines in Egypt may be caused in part by the passive transfer of maternal H5N1 antibodies to chicks, inhibiting their immune response to vaccination. We propose that the induction of a protective immune response to H5N1 is suppressed for an extended period in young chickens. This issue, among others, must be resolved and additional steps must be taken before the outbreaks in Egypt can be controlled.
Adaptive impact of the chimeric gene
Quetzalcoatl
in
Drosophila melanogaster
Authors: Rogers Rebekah L. , Bedford Trevor , Lyons Ana M. , Hartl Daniel L.
Published: June 2010

Chimeric genes, which form through the genomic fusion of two protein-coding genes, are a significant source of evolutionary novelty in
Drosophila melanogaster
. However, the propensity of chimeric genes to produce adaptive phenotypic changes is not fully understood. Here, we describe the chimeric gene
Quetzalcoatl
(
Qtzl
;
CG31864
), which formed in the recent past and swept to fixation in
D. melanogaster
.
Qtzl
arose through a duplication on chromosome 2L that united a portion of the mitochondrially targeted peptide
CG12264
with a segment of the polycomb gene
escl
. The 3′ segment of the gene, which is derived from
escl
, is inherited out of frame, producing a unique peptide sequence. Nucleotide diversity is drastically reduced and site frequency spectra are significantly skewed surrounding the duplicated region, a finding consistent with a selective sweep on the duplicate region containing
Qtzl
.
Qtzl
has an expression profile that largely resembles that of
escl
, with expression in early pupae, adult females, and male testes. However, expression patterns appear to have been decoupled from both parental genes during later embryonic development and in head tissues of adult males, indicating that
Qtzl
has developed a distinct regulatory profile through the rearrangement of different 5′ and 3′ regulatory domains. Furthermore, misexpression of
Qtzl
suppresses defects in the formation of the neuromuscular junction in larvae, demonstrating that
Qtzl
can produce phenotypic effects in cells. Together, these results show that chimeric genes can produce structural and regulatory changes in a single mutational step and may be a major factor in adaptive evolution.
Plasma membrane insertion of the AMPA receptor GluA2 subunit is regulated by NSF binding and Q/R editing of the ion pore
Authors: Araki Yoichi , Lin Da-Ting , Huganir Richard L.
Published: June 2010

The delivery of AMPA receptors to the plasma membrane is a critical step both for the synaptic delivery of these receptors and for the regulation of synaptic transmission. To directly visualize fusion events of transport vesicles containing the AMPA receptor GluA2 subunit with the plasma membrane we used pHluorin-tagged GluA2 subunits and total internal reflection fluorescence microscopy. We demonstrate that the plasma membrane insertion of GluA2 requires the NSF binding site within its intracellular cytoplasmic domain and that RNA editing of the Q/R site in the ion channel region plays a key role in GluA2 plasma membrane insertion. Finally, we show that plasma membrane insertion of heteromeric GluA2/3 receptors follows the same rules as homomeric GluA2 receptors. These results demonstrate that the plasma membrane delivery of GluA2 containing AMPA receptors is regulated by its unique structural elements.
Lack of Increased Colonization with Vancomycin-Resistant Enterococci during Preferential Use of Vancomycin for Treatment during an Outbreak of Healthcare-Associated Clostridium difficile Infection
Authors: Miller Mark , Bernard Lisa , Thompson Melissa , Grima Daniel , Pepin Jocelyne
Published: June 2010

Objective.

To assess whether use of oral vancomycin for treatment during an outbreak of Clostridium difficile infection (CDI) was associated with increased rates of colonization with vancomycin-resistant enterococci (VRE)..

Design.

A retrospective analysis of hospital databases.

Setting.

The Jewish General Hospital in Montreal, Quebec, Canada.

Methods.

We collected data regarding VRE colonization and CDI from November 1, 2000, through September 30, 2007, during which policies of preferential oral metronidazole or vancomycin treatment were implemented to control an outbreak of CDI. Four periods were considered: period 1, the preoutbreak period when metronidazole was used; period 2, the CDI outbreak period when metronidazole was used; period 3, the postoutbreak period when vancomycin was used; and period 4, the postoutbreak period when metronidazole was used.

Results.

A total of 2,412 cases of CDI and 425 cases of VRE colonization were identified. The rate of CDI increased significantly during period 2 and decreased to preoutbreak levels during period 3. The rate of VRE also increased during period 2 and decreased during the first 18 months of period 3. A clonal outbreak of cases of VRE (VanA) colonization was observed toward the end of period 3 and into period 4. Excluding the period of the clonal outbreak, there was a strong correlation between the number of cases of CDI and VRE colonization (r = 0.736; P = .001) and a negative association between VRE colonization and vancomycin use (r = —0.765; P = .04).

Conclusions.

Increased vancomycin use was not associated with an increase in VRE colonization over a 2-year period. Restriction of vancomycin use during CDI outbreaks because of the fear of increasing VRE colonization may not be warranted.
Separation of Ions from Volatile Organic Compounds Using High-Field Asymmetric Waveform Ion Mobility Spectrometry-Mass Spectrometer
Authors: Li Hua , Wang Xiao-hao , Tang Fei , Yang Ji , Ding Li
Published: June 2010

A combination of high-field asymmetric waveform ion mobility spectrometry (FAIMS) with mass spectrometer (MS) was analyzed. FAIMS separates ions from the volatile organic compounds in the gas-phase as an ion-filter for MS. The sample ions were created at ambient pressure by ion source, which was equipped with a 10.6 eV UV discharge lamp (Å = 116.5 nm). The drift tube of FAIMS is composed of two parallel planar electrodes and the dimension is 10 mm × 8 mm × 0.5 mm. FAIMS was investigated when driven by the high-filed rectangular asymmetric waveform with the peak-to-peak voltage of 1.36 kV at the frequency of 1 MHz and the duty cycle of 30%. The acetone, the butanone, and their mixture were adopted to characterize the FAIMS-MS. The mass spectra obtained from MS illustrate that there are ion-molecular reactions between the ions and the sample neutral molecular. And the proton transfer behavior in the mixture of the acetone and the butanone is also observed. With the compensation voltage tuned from −30 V to 10 V with a step size of 0.1 V, the ion pre-separation before MS is realized.
Chemical Effect on K Shell X-ray Fluorescence Parameters and Radiative Auger Ratios of Co, Ni, Cu, and Zn Complexes
Authors: Cengiz Erhan , Bıyıklıoǧlu Zekeriya , Küp Aylıkcı Nuray , Aylıkcı Volkan , Apaydın Gökhan , Tıraşoǧlu Engin , Kantekin Halit
Published: June 2010

The production cross-sections, intensity ratios, and radiative Auger intensity ratios of Co, Ni, Cu, and Zn elements in different complexes were measured. The chemical effects on the K shell fluorescence parameters and the radiative Auger intensity ratios of these elements were investigated and the changes in these parameters were interpreted according to the charge transfer process. The samples were excited by 59.5 keV γ-rays from a 241Am annular radioactive source. K X-rays emitted by samples were counted by an Ultra-LEGe detector with a resolution of 150 eV at 5.9 keV.
Effect of Energy Transfer on UV Spectra of “H-shaped" Azobenzene Derivatives
Authors: Li Hui-sheng , Lu Lu
Published: June 2010

A series of “H-shaped" organic dimers (azobenzene derivatives) exhibit linear absorption red shift compared with their corresponding monomers experimentally. Dipolar interaction model is not appropriate for the azobenzene derivatives due to the small distance between two “D-π-A" chains. Energy transfer model is suggested for explanation of the absorption red shift. Two necessary conditions for energy transfer were verified. In addition, bi-exponential florescence-delay behavior of the dimer as well as Bella's quantum chemistry calculation shows evidence of energy transfer.
Molecular Dynamics Study on Microstructure of Potassium Dihydrogen Phosphates Solution
Authors: Wang Kun , Lu Gui-wu , Zhou Guang-gang , Yang Hong-wang , Su Dong-dong
Published: June 2010

Molecular dynamics simulations were carried out to study the internal energy and microstructure of potassium dihydrogen phosphates (KDP) solution at different temperatures. The water molecule was treated as a simple-point-charge model, while a seven-site model for the dihydrogen phosphate ion was adopted. The internal energy functions and the radial distribution functions of the solution were studied in detail. An unusually large local particle number density fluctuation was observed in the system at saturation temperature. It has been found that the specific heat of oversaturated solution is higher than that of unsaturated solution, which indicates the solution experiences a crystallization process below saturation temperature. The radial distribution function between the oxygen atom of water and the hydrogen atom of the dihydrogen phosphate ion shows a very strong hydrogen bond structure. There are strong interactions between potassium cation and oxygen atom of dihydrogen phosphate ion in KDP solution, and much more ion pairs were formed in saturated solution.
Density Functional Theory Study of Mechanism of Cycloaddition Reaction Between Dimethyl-Silylene Carbene and Acetone
Authors: Lu Xiu-hui , Xiang Ping-ping , Shi Le-yi , Han Jun-feng , Lian Zhen-Xia
Published: June 2010

The mechanism of the cycloaddition reaction between singlet dimethyl-silylene carbene and acetone has been investigated with density functional theory, From the potential energy profile, it can be predicted that the reaction has two competitive dominant reaction pathways. The presented rule of this reaction: the [2+2] cycloaddition effect between the π orbital of dimethyl-silylene carbene and the π orbital of π-bonded compounds leads to the formation of a twisty four-membered ring intermediate and a planar four-membered ring product; The unsaturated property of C atom from carbene in the planar four-membered ring product, resulting in the generation of CH3-transfer product and silicic bis-heterocyclic compound.
Synthesis and Adsorption Study of BSA Surface Imprinted Polymer on CdS Quantum Dots
Authors: Tang Ping-ping , Cai Ji-bao , Su Qing-de
Published: June 2010

A new bovine serum albumin (BSA) surface imprinting method was developed by the incorporation of quantum dots (QDs) into molecularly imprinted polymers (MIP), which can offer shape selectivity. Preparation and adsorption conditions were optimized. Physical appearance of the QDs and QDs-MIP particles was illustrated by scanning electron microscope images. Photoluminescence emission of CdS was quenched when rebinding of the template. The quenching of photoluminescence emissions is presumably due to the fluorescence resonance energy transfer between quantum dots and BSA template molecules. The adsorption is compiled with Langmuir isotherm, and chemical adsorption is the rate-controlling step. The maximum adsorption capacity could reach 226.0 mg/g, which is 142.4 mg/g larger than that of undoped BSA MIP. This study demonstrates the validity of QDs coupled with MIP technology for analyzing BSA.
DETECT—a Density Estimation Tool for Enzyme ClassificaTion and its application to Plasmodium falciparum
Authors: Hung Stacy S. , Wasmuth James , Sanford Christopher , Parkinson John
Published: June 2010

Motivation: A major challenge in genomics is the accurate annotation of component genes. Enzymes are typically predicted using homology-based search methods, where the membership of a protein to an enzyme family is based on single-sequence comparisons. As such, these methods are often error-prone and lack useful measures of reliability for the prediction.

Results: Here, we present DETECT, a probabilistic method for enzyme prediction that accounts for the sequence diversity across enzyme families. By comparing the global alignment scores of an unknown protein to those of all known enzymes, an integrated likelihood score can be readily calculated, ranking the reaction classes relevant for that protein. Comparisons to BLAST reveal significant improvements in enzyme annotation accuracy. Applied to Plasmodium falciparum, we identify potential annotation errors and predict novel enzymes of therapeutic interest.

Availability: A standalone application is available from the website: http://www.compsysbio.org/projects/DETECT/

Contact:  john.parkinson@utoronto.ca

Supplementary information:  Supplementary data are available at Bioinformatics online.
Small RNAs in angiosperm gametophytes: from epigenetics to gamete development
Authors: Le Trionnaire Gaël , Twell David
Published: June 2010

The established role of various small RNA pathways in the epigenetic regulation of gene expression in the dipolid sporophytic generation of flowering plants contrasts sharply with the lack of knowledge of their role in haploid gametophyte generation. Several recent studies now uncover the operation of multiple small RNA pathways in male and female gametophytes and their essential roles in genome integrity, cell specification, and, most recently, sperm cell function, as described in the May 15, 2010, issue of Genes & Development by Ron and colleagues (pp. 1010–1021).
Neutral Red Staining for Plant Vacuoles
Authors: Schwab Birgit , Hülskamp Martin
Published: June 2010

INTRODUCTION

For almost 100 years, neutral red has been used to stain living cells and fixed tissue. It can be used as a general-purpose stain, a pH indicator (turning from red to yellow, as the medium becomes alkaline), or a nuclear stain. In this protocol, neutral red is used to stain plant vacuoles.
‘Finding a Life’ Among Undocumented Congolese Refugee Children in Tanzania
Authors: Mann Gillian
Published: June 2010

The majority of undocumented Congolese refugee children living in Dar es Salaam, Tanzania, experience extreme poverty and social exclusion, harassment and discrimination. Their fear of deportation, forcible removal to refugee camps and imprisonment is coupled with a strong feeling that they are unwelcome in Tanzania. These realities require that most children devote a huge amount of their energy to survival, both literally, in terms of physical needs such as food and water, and figuratively, in terms of maintaining their sense of self‐worth, dignity and purpose. This article is based on extensive fieldwork with more than 100 young people aged 7–18 years. I explore the ways children cope with the challenges posed by the conditions of everyday life and the strategies they employ in their quest to ‘find a life’, or make a future for themselves. I argue that by imagining a future, they are fighting against not only what war has done to them and their families but also against the very fact of being a refugee.
New non‐invasive method for evaluation of the stratum corneum structure in diseases with abnormal keratinization by immunofluorescence microscopy of desmoglein 1 distribution in tape‐stripped samples
Authors: OYAMA Zuiei , NAOE Yoshikazu , KIMURA Hiroko , MASUNAGA Takuji , SEISHIMA Mariko , AOYAMA Yumi , KITAJIMA Yasuo
Published: June 2010

The corneodesmosomes in the stratum corneum are critical for the maintenance of stratum corneum integrity. To evaluate the normal and diseased keratinization states in the epidermis, we studied the distribution of desmoglein 1 (DSG1), a major component of corneodesmosomes, in samples of the stratum corneum obtained by tape stripping, a non‐invasive method. Samples were collected from lesional skin of four patients with psoriasis and three with lichen planus, and from non‐lesional skin of three volunteers. Upper stratum corneum cells were obtained by tape stripping and skin biopsies were obtained from adjacent sites. Tape‐stripped samples were examined by immunofluorescence microscopy using anti‐DSG1 monoclonal antibody, in combination with histopathology of skin biopsies. In normal human stratum corneum, which shows basket‐woven orthokeratosis, DSG1‐containing fluorescent dots were distributed on the lateral cell–cell contact areas of plasma membrane, but not on the dorsal/ventral plasma membrane, and formed a well‐ordered hexagonal network structure. In psoriatic stratum corneum, fluorescent dots were distributed throughout the cell membrane at ventral aspects of corneocytes as well as at the lateral cell–cell contacts. In lichen planus, fluorescent dots were distributed homogeneously and/or heterogeneously on the ventral surface in some cells. Adjacent cells lacked DSG1 at the lateral cell–cell contacts, but were instead separated by distinctive black‐gap lines. These results suggest that the intercellular adhesion by DSG1 may depend on the lateral plasma membrane in normal human stratum corneum, on the dorsal/ventral plasma membrane in lichen planus, and on both lateral and dorsal/ventral plasma membranes in psoriatic stratum corneum. Tape stripping and DSG1 immunofluorescence visualizes adhesion features of corneocytes and has considerable potential for evaluation of abnormal keratinization and the process of healing in response to treatment.
Single‐dose oral fluconazole versus topical clotrimazole in patients with pityriasis versicolor: A double‐blind randomized controlled trial
Authors: DEHGHAN Mohammad , AKBARI Negin , ALBORZI Nazila , SADANI Somayeh , KESHTKAR Abas A.
Published: June 2010

This study was designed to compare the therapeutic effects of topical clotrimazole and systemic fluconazole in pityriasis versicolor. A double‐blind randomized controlled trial was carried out in the dermatological clinic of Gorgan, northern Iran, between April 2006 and May 2007. All consecutive patients with pityriasis versicolor were included and randomly divided into two groups. In the first group (G1), patients underwent treatment with a single dose of fluconazole capsule (400 mg) and placebo cream. In the second group (G2), patients underwent treatment with clotrimazole cream (twice daily) and placebo capsule. The course of treatment was 2 weeks. All subjects were re‐evaluated 2, 4 and 12 weeks after the end of the therapeutic course. After 2 weeks, the rate of complete resolution of disease was significantly higher in G2 than G1 (49.1% vs 30%). After 4 weeks, 41 patients (81.2%) of G1 and 52 patients (94.9%) of G2 showed complete resolution. After 12 weeks, 46 patients (92%) in G1 and 45 patients (81.8%) in G2 showed complete resolution. Recurrence rate in G1 and G2 were 6% and 18.2%, respectively. No complications were seen in either group. In this study, clinical response at week 4 was greater in the clotrimazole group than the fluconazole group. Recurrence at week 12 after treatment was less with oral fluconazole than clotrimazole cream. So, for better evaluation, more studies need to be done.
Cutaneous Malassezia microbiota of healthy subjects differ by sex, body part and season
Authors: AKAZA Narifumi , AKAMATSU Hirohiko , SASAKI Yasuyuki , TAKEOKA Shiori , KISHI Masataka , MIZUTANI Hiroshi , SANO Akiyo , HIROKAWA Keiko , NAKATA Satoru , MATSUNAGA Kayoko
Published: June 2010

Malassezia is a component of normal cutaneous resident microbiota. The aim of this study was to quantitatively clarify the differences in cutaneous Malassezia microbiota in healthy subjects by sex, body part and season. Samples were collected from the forehead, cheek, upper chest and upper back of 20 healthy men and 20 healthy women (average age 32 years) in summer and winter by the swab method. Malassezia DNA was analyzed using a real‐time PCR system. As a result, in sex, body parts and season, men, the upper trunk and summer showed the highest total numbers of cutaneous Malassezia species on average. There were also differences depending on the analytical method. The predominant species were M. restricta on the face of men, M. globosa and M. dermatis on the upper trunk of men, and M. globosa and M. sympodialis on the upper trunk of women. This study clarified that the cutaneous Malassezia microbiota of healthy subjects differed by sex, body part and season.
Generic and therapeutic substitutions in the UK: are they a good thing?
Authors: Duerden Martin G. , Hughes Dyfrig A.
Published: June 2010

There is considerable interest and debate concerning the place of generic substitution (switching from a brand to generic product); and on therapeutic substitution, that is, switching to a cheaper, but apparently equivalent, product, usually within the drug class. Generic substitution by pharmacists is standard practice in UK hospital settings, and is being proposed for implementation in primary care. Although most prescriptions are already written generically (83% in the community in England in 2008), there are still cost savings that could be made if generic medicines are substituted against prescriptions written by branded name or by getting prescribers to adhere to advice to prescribe generically. Therapeutic substitution is more contentious, as direct evidence to support equivalence is normally lacking. However, the price differential between established drugs whose patents have expired and for which generics are available and newer, branded medicines within the same therapeutic class, makes therapeutic substitution an attractive application of cost‐minimization analysis for the more efficient use of healthcare resources. Here we explore the tension that exists between the clinical appropriateness and safety of switching from an individual patient perspective and the consideration of value for money which is required to maximize population health from a health service perspective. Although substitution may affect individual patients (such as, for instance, reduced adherence, increased potential for medication error), it might be a price worth paying given the opportunity cost associated with the use of medicines that are clinically no better than cheaper alternatives.
Coordinated approaches to quantify long‐term ecosystem dynamics in response to global change
Authors: LUO YIQI , MELILLO JERRY , NIU SHULI , BEIER CLAUS , CLARK JAMES S. , CLASSEN AIMÉE T. , DAVIDSON ERIC , DUKES JEFFREY S. , EVANS R. DAVE , FIELD CHRISTOPHER B. , CZIMCZIK CLAUDIA I. , KELLER MICHAEL , KIMBALL BRUCE A. , KUEPPERS LARA M. , NORBY RICHARD J. , PELINI SHANNON L. , PENDALL ELISE , RASTETTER EDWARD , SIX JOHAN , SMITH MELINDA , TJOELKER MARK G. , TORN MARGARET S.
Published: June 2010

Many serious ecosystem consequences of climate change will take decades or even centuries to emerge. Long‐term ecological responses to global change are strongly regulated by slow processes, such as changes in species composition, carbon dynamics in soil and by long‐lived plants, and accumulation of nutrient capitals. Understanding and predicting these processes require experiments on decadal time scales. But decadal experiments by themselves may not be adequate because many of the slow processes have characteristic time scales much longer than experiments can be maintained. This article promotes a coordinated approach that combines long‐term, large‐scale global change experiments with process studies and modeling. Long‐term global change manipulative experiments, especially in high‐priority ecosystems such as tropical forests and high‐latitude regions, are essential to maximize information gain concerning future states of the earth system. The long‐term experiments should be conducted in tandem with complementary process studies, such as those using model ecosystems, species replacements, laboratory incubations, isotope tracers, and greenhouse facilities. Models are essential to assimilate data from long‐term experiments and process studies together with information from long‐term observations, surveys, and space‐for‐time studies along environmental and biological gradients. Future research programs with coordinated long‐term experiments, process studies, and modeling have the potential to be the most effective strategy to gain the best information on long‐term ecosystem dynamics in response to global change.
Dental behaviour management problems: the role of child personal characteristics
Authors: GUSTAFSSON ANNIKA , BROBERG ANDERS , BODIN LENNART , BERGGREN ULF , ARNRUP KRISTINA
Published: June 2010

International Journal of Paediatric Dentistry 2010; 20: 242–253

Aim.  This study aimed to investigate the role of dental fear (DF) and other personal characteristics in relation to dental behaviour management problems (DBMP).

Design.  A study group of 230 patients (7.5–19 years old; 118 girls), referred because of DBMP, was compared to a reference group of 248 same‐aged patients (142 girls) in ordinary dental care. Patients and their parents independently filled in questionnaires including measures of fear and anxiety, behavioural symptoms, temperamental reactivity, and emotion regulation.

Results.  Study group patients referred because of DBMP differed from the reference group in all investigated aspects of personal characteristics. In the multivariate analyses, DF was the only variable with consistent discriminatory capacity through all age and gender subgroups. Aspects of anxiety, temperament, and behavioural symptoms contributed, but differently for different subgroups and at different levels of dental fear.

Conclusions.  Among older children and adolescents, DF deserves to be re‐established as the single most important discriminating variable for DBMP at clearly lower scores than commonly used. Further research should focus on the different patterns of DBMP development, considering various personal characteristics that may trigger, maintain, or exacerbate young patients’ vulnerability to DF and DBMP.
Detection of oral streptococci with collagen‐binding properties in saliva specimens from mothers and their children
Authors: NOMURA RYOTA , NAKA SHUHEI , NAKANO KAZUHIKO , TANIGUCHI NAHO , MATSUMOTO MICHIYO , OOSHIMA TAKASHI
Published: June 2010

International Journal of Paediatric Dentistry 2010; 20: 254–260

Background.  Approximately 10–20% of Streptococcus mutans strains have been reported to possess collagen‐binding properties, whereas other species in the oral cavity with those properties remain to be elucidated.

Aim.  To identify strains with collagen‐binding properties and analyse their characteristics in comparison with S. mutans.

Design.  A total of 110 expectorated saliva specimens were collected from 55 pairs of mothers and their children. Bacterial strains with collagen‐binding properties were isolated and the species specified. In addition, strains with collagen‐binding properties isolated from mother–child pairs were analysed using molecular biological approaches.

Results.  The detection frequency of strains with collagen‐binding properties was shown to be 40.9%, among which S. salivarius was the most frequently detected, followed by S. mutans. The collagen‐binding activity of the S. mutans group was the highest, followed by S. salivarius. In addition, S. mutans and S. salivarius strains from 3 and 1 mother–child pairs, respectively, were shown to be the same clones.

Conclusions.  Our results indicate that S. mutans and S. salivarius are major species with collagen‐binding properties in the oral cavity, and that strains with such properties may be related to mother–child transmission.
Orofacial and systemic manifestations in 212 paediatric HIV patients from Chennai, South India
Authors: RANGANATHAN KANNAN , GEETHALAKSHMI ELUMALAI , KRISHNA MOHAN RAO UMADEVI , VIDYA KAAZHIYUR MUDIMBAIMANNAR , KUMARASAMY NAGALINGESWARAN , SOLOMON SUNITI
Published: June 2010

International Journal of Paediatric Dentistry 2010; 20: 276–282

Background.  Lesions in the mouth and in other tissues and organs (oral and systemic lesions) in paediatric HIV infection are diverse and show differences in clinical presentation and severity from that of adults. Very little data exist for oral lesions in paediatric population in India.

Aim.  To document and study oral and more widespread lesions in paediatric HIV seropositive patients.

Design.  A cross‐sectional study.

Setting.  Paediatric HIV seropositive patients at tertiary centers: Ragas Dental College and Hospital and YRG CARE, Chennai, India.

Patients and methods.  Two hundred and twelve paediatric HIV patients aged 0–14 years seen over a period of 1 year were included in the study. Clinical history, oral and systemic examinations were recorded by qualified dental surgeons and physicians.

Results.  One hundred and thirty‐two patients had oral lesions ranging in number from one to three. Oral lesions included oral candidiasis (OC) (56.1%), gingivitis (10.8%), oral pigmentation (6.1%), depapillation of the tongue (5.7%), ulcers (4.2%), and oral hairy leukoplakia (1.4%). The most common systemic lesion observed was nonspecific lymphadenopathy (74.1%) followed by pruritic eruptions (53.8%), measles (51.4%), and tuberculosis (TB) (49.1%). Thirty‐three (26%) patients were not immunosuppressed, 74 (58%) were moderately immunosuppressed, and 20 (15%) were severely immunosuppressed. Oral lesions exhibited positive correlation with lesions in other parts of the body.

Conclusion.  Oral lesions are a common feature in paediatric HIV infection. Their management is vital to improve the quality of life of the infected children.
Oral health and 22q11 deletion syndrome: thoughts and experiences from the parents’ perspectives
Authors: KLINGBERG GUNILLA , HALLBERG ULRIKA , ÓSKARSDÓTTIR SÓLVEIG
Published: June 2010

International Journal of Paediatric Dentistry 2010; 20: 283–292

Background.  22q11 deletion syndrome (22q11DS) is one of the most common multiple anomaly syndromes, and many dentists are likely to meet patients with the syndrome. Odontological research has focused on describing and analysing conditions/concepts based on the current state of knowledge within the dental profession. Yet, these research topics are not necessarily the most important issues for the patients.

Aims.  To explore and describe, by use of Grounded theory, parents’ experiences of oral health issues and needs for dental care in their children with 22q11DS.

Design.  Twelve parents from different regions in Sweden were interviewed. Analyses were carried out according to Grounded theory.

Results.  Parents recognised good oral health as important for the wellbeing of their children. Oral health was a concern and the parents described the fight for this as struggling in vain for good oral health in their child.

Conclusions.  Parents not only described their children’s oral health as important but also hard to gain. Thus, it is important that all patients with disabilities, regardless of whether there is a defined medical diagnosis or not, are identified and well taken care of in the dental care system.
Oral features and dental health in Hurler Syndrome following hematopoietic stem cell transplantation
Authors: McGOVERN ELEANOR , OWENS LAURA , NUNN JUNE , BOLAS ANDREW , MEARA ANNE O’ , FLEMING PADRAIG
Published: June 2010

International Journal of Paediatric Dentistry 2010; 20: 322–329

Background.  Hurler Syndrome is associated with a deficiency of a specific lysosomal enzyme involved in the degradation of glycosaminoglycans. Hematopoietic stem cell transplantation (HSCT) in early infancy is undertaken to help prevent the accumulation of glycosaminoglycans and improve organ function.

Aim.  To investigate the oral features and dental health of patients with Hurler Syndrome who have undergone successful HSCT.

Materials and methods.  Twenty‐five patients (median age 8.6 years) post‐HSCT (mean age 9.4 months) underwent oral assessment (mean of 7.5 years post‐HSCT).

Results.  Dental development was delayed. Numerous occlusal anomalies were noted including: open‐bite, class III skeletal base, dental spacing, primary molar infra‐occlusion and ectopic tooth eruption. Dental anomalies included hypodontia, microdontia, enamel defects, thin tapering canine crowns, pointed molar cusps, bulbous molar crowns and molar taurodontism. Tooth roots were usually short/blunted/spindle‐like in permanent molars. The prevalence of dental caries was low in the permanent dentition (mean DMFT 0.7) but high in the primary dentition (mean dmft 2.4). Oral hygiene instruction with plaque and or calculus removal was indicated in 71% of those that were dentate.

Conclusion.  Patients with Hurler Syndrome post‐HSCT are likely to have delayed dental development, a malocclusion, and dental anomalies, particularly hypodontia and microdontia.
Value of bitewing radiographs for detecting approximal caries in 6‐year‐old children in the Netherlands
Authors: POORTERMAN JAN H.G. , VERMAIRE ERIK H. , HOOGSTRATEN JOHAN
Published: June 2010

International Journal of Paediatric Dentistry 2010; 20: 336–340

Background.  When diagnosing caries using clinical judgment only, the prevalence of approximal caries is highly underestimated. Yet, surveys on this topic predominantly included adolescents and young adults.

Aim.  To determine the additional diagnostic value of bitewing radiographs in 6‐year‐old children and to detect approximal dentin caries in the primary dentition.

Design.  A total of 50 children were assessed both clinically (dmfs, oral hygiene) and radiographically by two experienced dentists. The relation between dmfs‐scores and amount of plaque was established using Pearson’s correlation coefficients at a significance level of 0.05.

Results.  In nine patients (18%) it was impossible to make radiographs. Bitewing radiography appeared to have an additional effect of 97% when only caries in dentin is considered. The additional value for detecting inadequate restorations was 600%. Furthermore, the dmfs was highly correlated to the amount of plaque found.

Conclusion.  Although not possible to achieve in all 6‐year‐old children, bitewing radiographs can reveal a considerable amount of carious surfaces and inadequate restorations, which appear clinically sound or adequate.