bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of the colicin A lysis protein in the expression of the colicin A operon
Authors: Cavard Danièle
Published: June 2009

Summary: The involvement of the cal gene, which encodes the colicin A lysis protein, in the expression of the colicin A operon is demonstrated. Colicin A synthesis by Escherichia coli was studied at various temperatures in cells containing either the wild-type colicin A operon or the colicin A operon with the cal gene deleted. The amount of colicin A produced was lower in cells containing the colicin A operon devoid of the cal gene than in wild-type cells. In cells treated with the antibiotic globomycin, the synthesis of colicin A was blocked in null cal mutants at all temperatures. It was blocked only at low temperature in cells containing the wild-type colicin A operon, but not in cells subjected to heat shock or azide treatment. The cal gene product may be an activator of colicin A expression and of its own expression. An unidentified product, possibly a heat-shock protein, may also be involved and could complement the cal gene product in some situations.
The properties and localization of Saprolegnia monoica chitin synthase differ from those of other fungi
Authors: Leal-Morales Carlos A. , Gay Lucien , Fèvre Michel , Bartnicki-García Salomón
Published: June 2009

Summary: The presence of non-fibrillar α-chitin in celluiosic fungi (class Oomycetes) poses intriguing questions as to its role, subcellular localization and evolutionary significance. Previous studies reported on the similarity of chitin synthase from Saprolegnia monoica with that of other fungi. The present work describes important dissimilarities. There was no evidence that the chitin synthase of S. monoica was present in small low-density vesicles (chitosomes). Chitin synthase sedimented with membranous components of high specific gravity (sp. gr. 1.177) that could be partially but distinctly separated from membranes harbouring most of the 1,3–glucan synthase in the cell csp. gr. 1.158). In contrast to other fungi, the chitin synthase from S. monoica was greatly stimulated by digitonin: both membrane-bound and dissociated chitin synthase showed little activity in the absence of digitonin. As in other fungi, the chitin synthase from S. monoica was solubilized by digitonin and remained zymogenic after dissociation. However, unlike the enzyme from other fungi, the solubilized chitin synthase of S. monoica had a lower sedimentation coefficient, was not stimulated by phospholipids and was not inhibited by high concentrations of digitonin. Unlike the enzyme from Mucor rouxii. the solubilized chitin synthase from S. monoica did not bind to a cation exchanger. The enzyme was partially purified by a four-step scheme that included sucrose density-gradient centrifugation, a single passage through a strong anion exchanger and two consecutive passages through a weak anion exchanger. The final preparation contained five to seven polypeptide bands that cochromatographed with the chitin synthase activity, some of which may be part of a presumed chitin synthase macromolecular complex.
The KIPHO5 gene encoding a repressible acid phosphatase in the yeast Kluyveromyces lactis: cloning, sequencing and transcriptional analysis of the gene, and purification and properties of the enzyme
Authors: Fermiñán Encarnación , Domínguez Angel
Published: June 2009

Summary: A secreted phosphate-repressible acid phosphatase from Kluyveromyces lactis has been purified and the N-terminal region and an internal peptide have been sequenced. Using synthetic oligodeoxyribonucleotides based on the sequenced regions, the genomic sequence, KIPHO5, encoding the protein has been isolated. The deduced protein, named KIPho5p, consists of 469 amino acids and has a molecular mass of 52 520 Da (in agreement with the data obtained after treatment of the protein with endoglycosidase H). The purified enzyme shows size heterogeneity, with an apparent molecular mass in the range 90-200 kDa due to the carbohydrate content (10 putative glycosylation sites were identified in the sequence). A 16 amino acid sequence at the N-terminus is similar to previously identified signal peptides in other fungal secretory proteins. The putative signal peptide is removed during secretion since it is absent in the mature secreted acid phosphatase. The gene can be induced 400-600-fold by phosphate starvation. Consensus signals corresponding to those described for Saccharomyces cerevisiae PHO4- and PHO2-binding sites are found in the 5′ region. Northern blot analysis of total cellular RNA indicates that the KIPHO5 gene codes for a 1.8 kb transcript and that its expression is regulated at the transcriptional level. Chromosomal hybridization indicated that the gene is located on chromosome II. The KIPHO5 gene of K. lactis is able to functionally complement a pho5 mutation of Sacch. cerevisiae. Southern blot experiments, using the KIPHO5 gene as probe, show that some K. lactis reference strains lack repressible acid phosphatase, revealing a different gene organization for this kind of multigene family of proteins as compared to Sacch. cerevisiae.
Kinetic analysis of morphological differentiation and protease production in Streptomyces albidoflavus SMF301
Authors: Kang Sung Gyun , Lee Kye Joon
Published: June 2009

Summary: The effects of specific growth rate and specific nutrient uptake rate on morphological differentiation of Streptomyces albidoflavus SMF301 were determined in chemostat cultures. Production of three types of proteases: chymotrypsin-like protease (CTP), trypsin-like protease (TLP) and metalloprotease (MTP) were analysed in relation to mycelium growth and spore formation. Production of CTP was closely linked to mycelium growth, whereas spore formation, TLP synthesis and MTP synthesis were inversely related to growth. Evaluation of various kinetic parameters [specific production rates of spores (q
spo), TLP (q
TLP), MTP (q
MTP) and CTP (q
CTP)] showed that mycelium growth rate and CTP production were optimal at 0.1 h−1, but submerged spore formation, TLP production and MTP production were optimal at 0.025 h−1. Changes in specific nutrient uptake rates [glucose (q
glu), ammonium ion (q
amn) and phosphate (q
pho)] affected sporulation and protease production; limitation of carbon, nitrogen and phosphate stimulated spore, TLP and MTP production.
Heat shock response and groEL sequence of Bartonella henselae and Bartonella quintana
Authors: Haake David A. , Summers Theresa A. , McCoy Adam M. , Schwartzman William
Published: June 2009

Summary: Transmission of Bartonella species from ectoparasites to the mammalian host involves adaptation to thermal and other forms of stress. In order to better understand this process, the heat shock response of Bartonella henselae and Bartonella quintana was studied. Cellular proteins synthesized after shift to higher temperatures were intrinsically labelled with [35S]methionine and analysed by gel electrophoresis and fluorography. The apparent molecular masses of three of the major heat shock proteins produced by the two Bartonella species were virtually identical, migrating at 70, 60 and 10 kDa. A fourth major heat shock protein was larger in B. quintana (20 kDa) than in B. henselae (17 kDa). The maximum heat shock response in B. quintana and B. henselae was observed at 39 °C and 42 °C, respectively. The groEL genes of both Bartonella species were amplified, sequenced and compared to other known groEL genes. The phylogenetic tree based on the groEL alignment places B. quintana and B. henselae in a monophyletic group with Bartonella bacilliformis. The deduced amino acid sequences of Bartonella GroEL homologues contain signature sequences that are uniquely shared by members of the Gram-negative α-purple subdivision of bacteria, which live within eukaryotic cells. Recombinant His6-GroEL fusion proteins were expressed in Escherichia coli to generate specific rabbit antisera. The GroEL antisera were used to confirm the identity of the 60 kDa Bartonella heat shock protein. These studies provide a foundation for evaluating the role of the heat shock response in the pathogenesis of Bartonella infection.
The phase-variable pilus-associated protein PilC is commonly expressed in clinical isolates of Neisseria gonorrhoeae, and shows sequence variability among strains
Authors: Bäckman Marianne , Källström Helena , Jonsson Ann-Beth
Published: June 2009

Summary: PilC is a phase-variable protein associated with pilus-mediated adherence of pathogenic Neisseria to target cells. In this study, 24 strains of Neisseria gonorrhoeae with known epidemiological data were examined for expression of PilC. All strains produced PilC independently of serovar and site of isolation. To investigate whether the PilC protein is conserved or variable among gonococcal strains, the complete nucleotide sequence of pilC in four strains, isolated from either rectum, throat or blood, was determined. The deduced amino acid sequence in these strains differed from each other and from the two PilC proteins of N. gonorrhoeae MS11. These data demonstrate that PilC is commonly expressed, but the PilC sequence may vary among gonococcal strains.
Genetic characterization of a phospholipase C gene from Candida albicans: presence of homologous sequences in Candida species other than Candida albicans
Authors: Bennett Désirée E. , McCreary Christine E. , Coleman David C.
Published: June 2009

Summary: Phospholipase C (PLC) enzymes are essential in regulating several important cellular functions in eukaryotes, including yeasts. In this study, PCR was used to identify a gene encoding PLC activity in Candida albicans, using oligonucleotide primers complementary to sequences encoding highly conserved amino acid regions within the X domains of previously characterized eukaryotic phospholipase C genes. The nucleotide sequence of the C. albicans gene, CAPLC1 (2997 bp), was determined from a recombinant clone containing C. albicans 132 A genomic DNA; it encoded a polypeptide of 1099 amino acids with a predicted molecular mass of 124.6 kDa. The deduced amino acid sequence of this polypeptide (CAPLC1) exhibited many of the features common to previously characterized PLCs, including specific X and Y catalytic domains. The CAPLC1 protein also exhibited several unique features, including a novel stretch of 18-19 amino acid residues within the X domain and an unusually long N-terminus which did not contain a recognizable EF-hand Ca2+-binding domain. An overall amino acid homology of more than 27% with PLCs previously characterized from Saccharomyces cerevisiae and Schizosaccharomyces pombe suggested that the CAPLC1 protein is a δ-form of phosphoinositide-specific PLC (PI-PLC). PLC activity was detected in cell-free extracts of both yeast and hyphal forms of C. albicans 132A following 7 h and 24 h growth using the PLC-specific substrate p-nitrophenylphosphorylcholine (p-NPPC). In addition, CAPLC1 mRNA was detected by reverse transcriptase PCR in both yeast and hyphal forms of C. albicans 132A at the same time intervals. Expression of CAPLC1 activity was also detected in extracts of Escherichia coli DH5x harbouring plasmids which contained portions of the CAPLC1 gene lacking sequences encoding part of the N-terminus. Southern hybridization and PCR analyses revealed that all C. albicans and Candida dubliniensis isolates examined possessed sequences homologous to CAPLC1. Sequences related to CAPLC1 were detected in some but not all isolates of Candida tropicalis, Candida glabrata and Candida parapsilosis tested, but not in the isolates of Candida krusei, Candida kefyr, Candida guillermondii and Candida lusitaniae examined. This paper reports the first description of the cloning and sequencing of a PLC gene from a pathogenic yeast species.
Resistance to cefotaxime and peptidoglycan composition in Enterococcus faecalis are influenced by exogenous sodium chloride
Authors: Mainardi Jean-Luc , Billot-Klein Daniele , Coutrot Anne , Legrand Raymond , Schoot Bernard , Gutmann Laurent
Published: June 2009

SUMMARY: The influence of NaCl on the susceptibility of Enterococcus faecalis to cefotaxime was tested with JH2-2, a laboratory strain, and 20 clinical strains grown on tryptic soy agar supplemented with 5% horse blood. Growth with 3% NaCl in the medium resulted in an increase in cefotaxime resistance and the appearance of a heterogeneous resistance phenotype: for the majority of the strains, the MlCs of cefotaxime increased from 4 to 512 pg m1-Y By a competition assay using cefotaxime and [3H]benzylpenicillin, it was shown for strain JH2-2 that at the MIC penicillin-binding protein (PBP) 2 and PBP3 were the apparent essential PBPs in medium without NaCI, whilst the low-affinity PBPs 4 and 1 were the apparent essential PBPs for cell growth in medium containing 3% NaCl. Analysis of JH2-2 peptidoglycan by HPLC and MS after growth in the presence of 3% NaCl showed a relative increase in unsubstituted monomers and a relative decrease in alanine- and dialanine-substituted monomers. It is therefore hypothesized that modification of the number of alanine-substituted precursors in the presence of NaCl could interfere with the functions of the different PBPs and thus play a role in cefotaxime resistance in E. faecalis.
Characterization and possible functions of a new filamentous bacteriophage from Vibrio cholerae 0139
Authors: Jouravleva Elena A. , McDonald Gregory A. , Garon Claude F. , Boesman-Finkelstein Mary , Finkelstein Richard A.
Published: June 2009

The emergence and rapid rise to dominance of Vibrio cholerae O139 in India and Bangladesh in 1992 led to the consideration that choleraphage might serve as both a selective mechanism and a means for horizontal transmission of genetic information. A filamentous phage ‘493′ from O139 strain AJ27-493 has been purified and partially characterized. The phage was inactive on classical biotype V. cholerae 01 but it was active on El Tor biotype strains isolated prior to 1994 when El Tor re-emerged in Bangladesh. More recent El Tor isolates were all resistant to the phage. The phage was also active on O139 strains. Unlike the filamentous ctxφ, the receptor for 493 is not TcpA. The phage genome was a 9.3 kb closed circular single-stranded molecule containing a 0.4 kb double-stranded stem supporting a 2 kb single-stranded loop. A 283 bp fragment was cloned and used as a probe in Southern hybridization, in parallel with total phage 493 DNA. These probes hybridized both chromosomally and extrachromosomally with most O139 strains, but not with O1 strains. Infection of hybridization-negative El Tor or O139 strains resulted in the presence of hybridizing loci (both plasmid and chromosomal), in the appearance of an 18 kDa protein, and in marked alterations in colonial morphology. Phage 493 is clearly distinct from other O139 choleraphages which have been described. Phage 493 DNA hybridized with an encapsulated non-O1 (O31) strain (NRT36S) which was isolated before O139 was recognized. NRT36S also produces a phage which can infect El Tor strains with low efficiency. Further studies may reveal whether bacteriophage play a role in the emergence and the territoriality of new choleragenic vibrios.
Molecular characterization of an autolytic amidase of Listeria monocytogenes EGD
Authors: McLaughlan Anna M. , Foster Simon J.
Published: June 2009

The gene encoding a 102 kDa autolysin has been cloned from an expression library of Listeria monocytogenes EGD genomic DNA, using a direct screening protocol. The encoded protein has two domains, an N-terminal enzymic domain showing a high level of homology to the amidase domain of the major autolysin (atl) of Staphylococcus aureus, and a C-terminal, putative cell-wall-binding domain containing four imperfect direct repeats. In order to examine the role of the enzyme, the autolysin-encoding gene was insertionally inactivated by site-specific integration of a temperature sensitive plasmid. The enzyme accounts for 66% of the total lytic enzyme activity when L. monocytogenes walls are used as substrate and several of the major autolytic bands are missing on renaturing gels when compared to the wild-type. The enzyme does not appear to be directly involved in cell separation but has a role in motility. Characterization of the recombinant enzyme expressed in Escherichia coli has revealed it to be an amidase and to be able to hydrolyse a range of peptidoglycan substrates.
Cloning of the haemocin locus of Haemophilus influenzae type b and assessment of the role of haemocin in virulence
Authors: Murley Yvette M. , Edlind Thomas D. , Plett P Artur , LiPuma John J.
Published: June 2009

The bacteriocin haemocin (HMC) is produced by most type b strains of Haemophilus influenzae, including strains determined to be genetically diverse, and is toxic to virtually all non-type b strains of H. influenzae, both encapsulated and non-encapsulated. Examination of the deduced amino acid sequences of several genes upstream of the previously identified HMC immunity gene (hmcl) revealed several features common to class II bacteriocins of certain Gram-positive bacteria. Mutagenesis of the open reading frame immediately upstream of hmcl resulted in a loss of the HMC production phenotype. When an HMC-producing strain of H. influenzae and the HMC-deficient isogenic mutant were compared for invasion in the infant-rat model, the HMC-producing strain was found to invade significantly earlier; however, a significantly higher number of rats infected with the isogenic mutant became bacteraemic as compared with those infected with the HMC-producing parent.
Mutants of Rhizobium tropici strain CIAT899 that do not induce chlorosis in plants
Authors: O'Connell Kevin P , Raffel Sandra J. , Saville Barry J. , Handelsman Jo
Published: June 2009

Type B strains of Rhizobium tropici induce severe foliar chlorosis when applied at planting to seeds of symbiotic host and non-host dicotyledonous plants. A Tn5-induced mutant, designated CT4812, of R. tropici strain CIAT899 that was unable to induce chlorosis was isolated. Cloning and sequencing of the DNA flanking the transposon in CT4812 revealed that the Tn5 insertion is located in a gene similar to glnD, which encodes uridylyltransferase/uridylyl-removing enzyme in enteric bacteria. Two marker-exchange mutants with insertions in glnD also failed to induce chlorosis in bean (Phaseolus vulgaris) plants. The 5′-most insertion in glnD (in mutant strain ME330) abolished the ability of R. tropici to utilize nitrate as a sole carbon source, whereas a mutation in glnD further downstream (in mutant strain ME245) did not have an obvious effect on nitrate utilization. A gene similar to the Salmonella typhimurium virulence gene mviN overlaps the 3′ end of the R. tropici glnD homologue. A mutation in mviN had no effect on the ability of CIAT899 to induce chlorosis in bean plants. Therefore the glnD homologue, but not mviN, appears to be required for induction of chlorosis in plants by R. tropici strain CIAT899. A high nitrogen:carbon ratio in the rhizosphere of bean plants also prevented R. tropici from inducing chlorosis in bean plants. Mutations in either the glnD homologue or mviN had no significant effect on root nodule formation or acetylene reduction activity. A mutation in mviN eliminated motility in R. tropici. The sequence data, the inability of the glnD mutant to utilize nitrate, and the role of the R. tropici glnD gene in chlorosis induction in plants,a process that is nitrogen regulated, suggest that glnD plays a role in nitrogen sensing in R. tropici as its homologues do in other organisms.
A stomatin-like protein encoded by the slp gene of Rhizobium etli is required for nodulation competitiveness on the common bean
Authors: You Zerong , Gao Xuefeng , Ho Mei M. , Borthakur Dulal
Published: June 2009

Rhizobium etli strain TAL182 is a competitive strain for effective nodulation of beans. From this strain, a novel gene was isolated, slp, which is 669 bp in size and required for nodulation competition on the common bean. The slp knockout mutant of TAL182 is defective in nodulation competition, shows reduced growth in the presence of 200 mM NaCl, KCl or LiCl and is complemented by the cloned slp gene. The deduced amino acid sequence of slp shows 66-72% similarity to stomatin proteins of Homo sapiens, Mus musculus and Caenorhabditis elegans. Expression of slp in Escherichia coli from a T7 promoter shows a 26 kDa protein which cross-reacts with human-stomatin-specific polyclonal antibody. Like the human stomatin protein, the slp-deduced protein, Slp, is very hydrophilic except for a single hydrophobic membrane-spanning domain. Among various bean-nodulating rhizobia, slp is present in R. etli, Rhizobium leguminosarum bv. phaseoli and Rhizobium tropici type A strains but is absent in R. tropici type B strains. It is also absent in Bradyrhizobium and several other Rhizobium spp.
Differential expression of genes under control of the mating-type genes in the secondary mycelium of Schizophyllum commune
Authors: Ásgeirsdóttir Sigrídur A. , van Wetter Marianne A. , Wesselsd Joseph G. H.
Published: June 2009

The Schizophyllum commune SC3 gene, which encodes a hydrophobin that coats aerial hyphae, is expressed in both monokaryons and dikaryons. The dikaryons were formed by mating two monokaryons with different MATA and MATB genes, leading to activation of the MATA- and MATB-controlled pathways (MATA-on and MATB-on). In contrast to the monokaryons, the dikaryons also expressed other hydrophobin genes (SC1, SC4) as well as a gene (SC7) encoding a hydrophilic wall protein. None of these four genes was expressed in MATA-off MATB-on mycelia, indicating that MATB-on represses SC3 and that both MATA-on and MATB-on are required for activation of SC1, SC4 and SC7. In fruiting dikaryons, immunolabelling revealed that SC3p was produced by aerial hyphae but not by hyphae that constitute the fruit-body tissue. In contrast to aerial hyphae, the latter produced dikaryon-specific transcripts and secreted SC7p into the extracellular matrix of the tissue. This suggests that in the aerial hyphae of the dikaryon the MATB-on pathway was not effective (MATB-off). We observed that in these aerial hyphae the two nuclei were wider apart than in a typical dikaryon. Although other explanations are not ruled out, we tentatively propose that effective interaction of different MATB genes requires proximity of the two nuclei containing these genes, and that disruption of this binucleate state represents a novel mechanism of gene control for spatial cell differentiation in the secondary mycelium.
Neocallimastix frontalis enolase gene, enol: first report of an intron in an anaerobic fungus
Authors: Durand R. , Fischer M. , Rascle C. , Fvre M.
Published: June 2009

A DNA clone containing a putative enolase gene was isolated from a genomic DNA library of the anaerobic fungus Neocallimastix frontalis. It was deduced from sequence comparisons that the enolase gene was interrupted by a large 331 bp intron. The enolase gene, termed enol, has an ORF of 1308 bp and encodes a predicted 436 amino acid protein. The deduced amino acid sequence shows high identity (715-71%) to those of enolases from the yeasts Saccharomyces cerevisiae and Candida albicans. The G+ C content of the enolase coding sequence (438 mol%) is considerably higher than the G + C content of the intervening sequence (142 mol%) or the 5' and 3' non-translated flanking sequences (152 and 47 mol%, respectively). The codon usage of the N. frontalis enolase gene was very biased as has been found for the highly expressed genes of yeast and filamentous fungi. The gene has all the canonical features (polyadenylation signal, intron splicing boundaries) of genes isolated from aerobic filamentous fungi. Only one enolase gene could be detected in N. frontalis genomic DNA by Southern analysis with a homologous probe. RNA analysis detected a single enolase transcript of about 16 kb. When mycelium was grown on glucose, levels of enolase mRNA were markedly increased by comparison with enolase mRNA levels in mycelium grown on cellulose, suggesting that expression of the N. frontalis enolase gene was transcriptionally regulated by the carbon source.
The Gibberella fujikuroi niaD Gene Encoding Nitrate Reductase: Isolation, Sequence, Homologous Transformation and Electrophoretic Karyotype Location
Authors: Tudzynski Bettina , Mende Katrin , Weltring Klaus-Michael , Kinghorn James R. , Unkles Shiela E.
Published: June 2009

The Gibberella fujikuroi niaD gene, encoding nitrate reductase, has been isolated and used to develop an efficient homologous transformation system. A cosmid vector designated pGFniaD was generated based on niaD selection and shown to give comparable transformation efficiencies. Using pGFniaD, a genomic library was prepared and used for genetic transformations, giving frequencies of up to 200 transformants per μg DNA. Of 15 transformants analysed by Southern blots, six showed homologous integration whilst the remaining nine integrated at heterologous sites, indicating that the vector may be used reliably for both types of integration. The system therefore may be used both for self-cloning of gibberellin biosynthetic genes on the basis of complementation of defective mutants, and also for gene disruption experiments. Electrophoretic karyotype determination suggested at least 11 chromosomes ranging from 2 to 6 Mb, the total genome size being at least 37 Mb. The niaD gene was assigned to chromosome V by Southern blot analysis. The niaD gene is interrupted by one intron, and remarkably the promoter sequence, but not the 3′ untranslated sequence, is highly homologous to that of the corresponding Fusarium oxysporum gene. This situation appears to be unique with respect to the promoter regions of corresponding genes in related species of filamentous fungi.
Effect of the Nitrogen Source on Phycobiliprotein Synthesis and Cell Reserves in A Chromatically Adapting Filamentous Cyanobacterium
Authors: Liotenberg Sylviane , Campbell Douglas , Rippka Rosmarie , Houmard Jean , de Marsac Nicole Tandeau
Published: June 2009

Cyanobacteria can utilize nitrate or ammonium as a source of fixed nitrogen for cell growth. In the filamentous Calothrix sp. strain PCC 7601, these two sources of nitrogen differently influenced the phycobiliprotein composition of the phycobilisomes, the major light-harvesting antennae. When compared to nitrate, growth in the presence of ammonium resulted in intracellular steadystate levels 35% lower for phycoerythrin and 46% higher for phycocyanin. Besides these differences in cell pigmentation, a rapid but transient accumulation of cyanophycin granule polypeptide occurred in ammoniumgrown cells, while these macromolecules were not detected in cells grown with nitrate. In contrast, glycogen reserves displayed a dynamic pattern of accumulation and disappearance during cell growth which varied only slightly with the nitrogen source. The observed changes in cell pigmentation are reminiscent of the phenomenon of complementary chromatic adaptation, in which green and red wavelengths promote the syntheses of phycoerythrin and phycocyanin-2, respectively. As in complementary chromatic adaptation, the regulation of synthesis of phycoerythrin and phycocyanin-2 by the nitrogen source occurred mainly at the mRNA level. Moreover, the transcriptional start sites for the expression of the cpeBA and the cpc2 operons, which respectively encode the two subunits of phycoerythrin and phycocyanin-2, were the same in cells grown in nitrate or ammonium, and identical to those in green-and red-light-grown cells. The results of this study suggest that acclimation to the spectral light quality and to the nitrogen source share some common regulatory elements.
The requirement of tumour necrosis factor-α and interferon-γ for the expression of protective immunity to secondary murine tularaemia depends on the size of the challenge inoculum
Authors: Sjöstedt Anders , North Robert J. , Conlan J. Wayne
Published: June 2009

The present study was conducted to determine the extent to which the cytokines tumour necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) are required to protect against primary or secondary murine tularaemia caused by the live vaccine strain of the facultative intracellular bacteriumFrancisella tularensis. It is shown that non-immune mice treated with neutralizing monoclonal antibodies (mAbs) against TNF-α and IFN-γ are rendered defenceless against otherwise sublethal intravenous inocula of the bacterium. Treatment with either of the anti-cytokine mAbs resulted in even a very small inoculum of 500 c.f.u. of the pathogen multiplying unrestrictedly in the livers, spleens and lungs of non-immune mice to rapidly reach lethal numbers. By contrast,Francisella-immune mice treated with either of the mAbs remained capable of resolving secondary infection with 50-fold larger inocula. However, the need for TNF-α and IFN-γ for controlling secondary tularaemia became critical when challenge inocula exceeded 106c.f.u. Overall, the results imply that different defence mechanisms operate to control primary versus secondary murine tularaemia. Additionally, they show that the need for TNF-α and IFN-γ to combat secondary infection depends on the size of the challenge inoculum.
Efficacy of an intravenous proton pump inhibitor after endoscopic therapy with epinephrine injection for peptic ulcer bleeding in patients with uraemia: a case‐control study
Authors: TSENG G.‐Y. , FANG C.‐T. , LIN H.‐J. , YANG H.‐B. , TSENG G.‐C. , WANG P.‐C. , LIAO P.‐C. , CHENG Y.‐T. , HUANG C.‐H.
Published: May 2009

Background  Patients with peptic ulcer bleeding and uraemia are prone to re‐bleeding.

Aim  To compare the efficacy of an intravenous proton pump inhibitor in treating peptic ulcer bleeding in patients with uraemia and those without uraemia.

Methods  High‐risk peptic ulcer bleeding patients received endoscopic therapy with epinephrine (adrenaline) injection plus intravenous omeprazole (40 mg bolus followed by 40 mg infusion every 12 h) for 3 days. Re‐bleeding, volume of blood transfusion, hospital stay, need for surgery, and mortality were analysed.

Results  The uraemic group had similar 7‐day re‐bleeding rate (6/42, 14.29% vs. 6/46, 13.04%, P = 0.865) to that of non‐uraemic patients, but more re‐bleeding episodes beyond 7 days (4/42, 9.52% vs. 0/46, 0%, P = 0.032, OR [95% CI] = 1.105 [1.002–1.219]) and all‐cause mortality (4/42 vs. 0/46 P = 0.032, OR [95% CI] = 1.105 [1.002–1.219]). The uraemic group also had more units of blood transfusion after endoscopic therapy (mean ± s.d. 4.33 ± 3.35 units vs. 2.15 ± 1.65 units, P < 0.001), longer hospital stay (mean ± s.d. 8.55 ± 8.12 days vs. 4.11 ± 1.60 days, P < 0.001) and complications during hospitalization (9/42 vs. 0/46, P = 0.001, OR [95% CI] = 1.273 [1.087–1.490]).

Conclusion  Endoscopic therapy with epinephrine injection plus an intravenous proton pump inhibitor can offer protection against early re‐bleeding in uraemic patients with peptic ulcer bleeding, but has a limited role beyond 7 days.
Occupational asbestos exposure and digestive cancers – a cohort study
Authors: CLIN B. , MORLAIS F. , DUBOIS B. , GUIZARD A.‐V. , DESOUBEAUX N. , MARQUIGNON M.‐F. , RAFFAELLI C. , PARIS C. , GALATEAU‐SALLE F. , LAUNOY G. , LETOURNEUX M.
Published: May 2009

Background  Although the role of asbestos in the genesis of mesothelioma and primary bronchopulmonary cancers has been established, results from studies focusing on the relationship between occupational exposure to asbestos and digestive cancer remain contradictory.

Aim  To determine whether occupational asbestos exposure increases the incidence of digestive cancers.

Methods  Our study was a retrospective morbidity study based on 2024 subjects occupationally exposed to asbestos. The incidence of digestive cancer was calculated from 1st January 1978 to 31st December 2004 and compared with levels among the local general population using Standardized Incidence Ratios. Asbestos exposure was assessed using the company’s job exposure matrix.

Results  Eighty‐five cases of digestive cancer were observed within our cohort, for an expected number of 66.90 (SIR = 1.27 [1.01; 1.57]). A significantly elevated incidence, particularly notable among women, was observed for peritoneal mesothelioma, independently of exposure levels. A significantly elevated incidence was also noted among men for cancer of small intestine and oesophagus, for cumulative exposure indexes for asbestos above 80 fibres/mL × years. A significantly elevated incidence of cancer of the small intestine was also observed among men having been exposed to asbestos for periods in excess of 25 years and for mean exposure levels in excess of 4 fibres/mL.

Conclusions  This study suggests the existence of a relationship between exposure to asbestos and cancer of the small intestine and of the oesophagus in men.
Clinical trial: a randomized trial of pegylated‐interferon‐α‐2a plus ribavirin with or without amantadine in treatment‐naïve or relapsing chronic hepatitis C patients
Authors: LANGLET P. , D’HEYGERE F. , HENRION J. , ADLER M. , DELWAIDE J. , VAN VLIERBERGHE H. , MULKAY J. P. , LASSER L. , BRENARD R. , HORSMANS Y. , MICHIELSEN P. , LAUREYS A. , NEVENS F.
Published: May 2009

Background  The combination therapy of pegylated‐interferon‐α2a plus ribavirin is considered as the standard of care for patients with chronic hepatitis C. A sustained viral response is obtained in 40–50% of naïve patients with genotype 1 and in around 80% of naïve patients with genotype 2 or 3.

Aim  To assess whether amantadine, added to the conventional combination therapy, could improve the treatment efficacy.

Methods  In all, 630 patients (intent‐to‐treat population) with chronic hepatitis C were randomized into two groups: 316 patients (treatment group) received pegylated‐interferon‐α2a (180 μg once weekly) plus ribavirin (1000–1200 mg/daily) with amantadine (200 mg/daily); 314 patients (control group) received pegylated‐interferon‐α2a (180 μg once weekly) plus ribavirin (1000–1200 mg/daily) without amantadine. The duration of the treatment was 48 weeks for genotypes 1, 4, 5 and 6, and 24 weeks for genotypes 2 and 3.

Results  There was no statistically significant difference between treatments groups for any of the variables tested for. Subgroups of patients likely to take advantage of the addition of amantadine were not identified.

Conclusions  This large study definitely excludes the role of amantadine in addition of conventional combination therapy in the treatment of chronic hepatitis C patients.
Pediatric primary care to help prevent child maltreatment: the Safe Environment for Every Kid (SEEK) model
Authors: Reading Richard
Published: June 2009

.
 
Dubowitz H.,
Feigelman S.,
Lane W. &
Kim J.
(
2009
)

,
123
,
858
–
864
.
 
DOI: 10.1542/peds.2008‐1376
.

Context Effective strategies for preventing child maltreatment are needed. Few primary care‐based programmes have been developed, and most have not been well evaluated.

Objective Our goal was to evaluate the efficacy of the Safe Environment for Every Kid (SEEK) model of pediatric primary care in reducing the occurrence of child maltreatment.

Methods A randomized trial was conducted from June 2002 to November 2005 in a university‐based resident continuity clinic in Baltimore, Maryland. The study population consisted of English‐speaking parents of children (0–5 years) brought in for child health supervision. Of the 1118 participants approached, 729 agreed to participate, and 558 of them completed the study protocol. Resident continuity clinics were cluster randomized by day of the week to the model (intervention) or standard care (control) groups. Model care consisted of (1) residents who received special training; (2) the Parent Screening Questionnaire; and (3) a social worker. Risk factors for child maltreatment were identified and addressed by the resident physician and/or social worker. Standard care involved routine pediatric primary care. A subset of the clinic population was sampled for the evaluation. Child maltreatment was measured in three ways: (1) child protective services reports using state agency data; (2) medical chart documentation of possible abuse or neglect; and (3) parental report of harsh punishment via the Parent‐Child Conflict Tactics scale.

Results Model care resulted in significantly lower rates of child maltreatment in all the outcome measures: fewer child protective services reports, fewer instances of possible medical neglect documented as treatment non‐adherence, fewer children with delayed immunizations and less harsh punishment reported by parents. One‐tailed testing was conducted in accordance with the study hypothesis.

Conclusions The SEEK model of pediatric primary care seems promising as a practical strategy for helping prevent child maltreatment. Replication and additional evaluation of the model are recommended.
The clinical effectiveness of different parenting programmes for children with conduct problems: a systematic review of randomised controlled trials
Authors: Reading Richard
Published: June 2009

.
 
Dretzke J.,
Davenport C.,
Frew E.,
Barlow J.,
Stewart‐Brown S.,
Bayliss S.,
Taylor R. S.,
Sandercock J. &
Hyde C.
(
2009
)

,
3
,
7
.
 
DOI: 10.1186/1753‐2000‐3‐7
.

Background Conduct problems are common, disabling and costly. The prognosis for children with conduct problems is poor, with outcomes in adulthood including criminal behaviour, alcoholism, drug abuse, domestic violence, child abuse and a range of psychiatric disorders. There has been a rapid expansion of group‐based parent‐training programmes for the treatment of children with conduct problems in a number of countries over the past 10 years. Existing reviews of parent training have methodological limitations such as inclusion of non‐randomized studies, the absence of investigation for heterogeneity prior to meta‐analysis or failure to report confidence intervals. The objective of the current study was to systematically review randomized controlled trials (RCTs) of parenting programmes for the treatment of children with conduct problems.

Methods Standard systematic review methods were followed including duplicate inclusion decisions, data extraction and quality assessment. Twenty electronic databases from the fields of medicine, psychology, social science and education were comprehensively searched for RCTs and systematic reviews to February 2006. Inclusion criteria were: RCT; of structured, repeatable parenting programmes; for parents/carers of children up to the age of 18 with a conduct problem; and at least one measure of child behaviour. Meta‐analysis and qualitative synthesis were used to summarize included studies.

Results A total of 57 RCTs were included. Studies were small with an average group size of 21. Metaanalyses using both parent (SMD1−0.67; 95% CI: −0.91, −0.42) and independent (SMD −0.44; 95% CI: −0.66, −0.23) reports of outcome showed significant differences favouring the intervention group. There was insufficient evidence to determine the relative effectiveness of different approaches to delivering parenting programmes.

Conclusion Parenting programmes are an effective treatment for children with conduct problems. The relative effectiveness of different parenting programmes requires further research.
Evaluation of metaflumizone granular fly bait for management of houseflies
Authors: AHMAD A. , ZUREK L.
Published: May 2009

The housefly, Musca domestica L. (Diptera: Muscidae), is a pest of great veterinary and public health importance. In this study, the efficacy of metaflumizone granular fly bait was assessed on first generation (F1) housefly adults raised from flies collected at a cattle feedlot in Kansas. All bioassays were conducted as choice tests, with flies having ad libitum access to water, granular sugar and bait. A commercial methomyl‐based bait (Golden MalrinTM) was used as positive control; no bait (water and granular sugar only) was used as negative control. Fly mortality was recorded on days 2, 7 and 14. The metaflumizone bait was significantly more slow‐acting than the methomyl bait (mortality rates after 2 days of exposure were 49.9% and 57.9%, respectively). However, there were no significant differences in cumulative mortality later in the bioassays. Cumulative mortality rates on days 7 and 14 were 96.1% (metaflumizone), 91.4% (methomyl) and 99.0% (metaflumizone), 97.6% (methomyl), respectively. Our results demonstrate that the metaflumizone granular fly bait may be an effective modality for incorporation into management programmes for houseflies in and around livestock production facilities as well as in residential settings.
Functional roles of the pre‐sensor I insertion sequence in an AAA+ bacterial enhancer binding protein
Authors: Burrows Patricia C. , Schumacher Jörg , Amartey Samuel , Ghosh Tamaswati , Burgis Timothy A. , Zhang Xiaodong , Nixon B. Tracy , Buck Martin
Published: May 2009

Molecular machines belonging to the AAA+ superfamily of ATPases use NTP hydrolysis to remodel their versatile substrates. The presence of an insertion sequence defines the major phylogenetic pre‐sensor I insertion (pre‐SIi) AAA+ superclade. In the bacterial σ54‐dependent enhancer binding protein phage shock protein F (PspF) the pre‐SIi loop adopts different conformations depending on the nucleotide‐bound state. Single amino acid substitutions within the dynamic pre‐SIi loop of PspF drastically change the ATP hydrolysis parameters, indicating a structural link to the distant hydrolysis site. We used a site‐specific protein–DNA proximity assay to measure the contribution of the pre‐SIi loop in σ54‐dependent transcription and demonstrate that the pre‐SIi loop is a major structural feature mediating nucleotide state‐dependent differential engagement with Eσ54. We suggest that much, if not all, of the action of the pre‐SIi loop is mediated through the L1 loop and relies on a conserved molecular switch, identified in a crystal structure of one pre‐SIi variant and in accordance with the high covariance between some pre‐SIi residues and distinct residues outside the pre‐SIi sequence.
Auxin transport into cotyledons and cotyledon growth depend similarly on the ABCB19 Multidrug Resistance‐like transporter
Authors: Lewis Daniel R. , Wu Guosheng , Ljung Karin , Spalding Edgar P.
Published: June 2009

ABCB19 of Arabidopsis thaliana (formerly known as MDR1 and PGP19) belongs to the Multidrug Resistance‐like (MDR) or B group of the ATP‐binding cassette (ABC) transporter superfamily, and mediates polar auxin transport in stems and roots. Here we have investigated the role of ABCB19 and auxin distribution in cotyledon development. During embryogenesis, confocal microscopy showed ABCB19 protein to be present in cotyledons during their main growth phase, but not later. Analysis of ProDR5:GFP expression patterns showed a significantly diminished and restricted auxin distribution pattern in abcb19 cotyledons. Nonetheless, development of abcb19 embryonic cotyledons was very similar to that of wild‐type. Post‐germination, ABCB19 was present in the plasma membrane of cotyledon epidermal, mesophyll and petiole cells during blade expansion. Post‐germination cotyledon blade expansion in abcb19 was 65% slower than in wild‐type, although the epidermal cell area was reduced by only 17%. The growth rate reduction quantitatively correlated with reduced auxin levels rather than auxin sensitivity as indicated by quantitative ProDR5:GUS assays and direct auxin measurements, and may be explained by the 50% reduction in the import of auxin through the petioles of abcb19 cotyledons during the period of maximum expansion. Taken together, these data indicate that cotyledon expansion during the establishment of photoautotrophic growth depends on ABCB19‐mediated auxin import.
Controlling SARS: a review on China’s response compared with other SARS‐affected countries
Authors: Ahmad Amena , Krumkamp Ralf , Reintjes Ralf
Published: June 2009

Objective  To summarise the major control measures implemented by severe acute respiratory syndrome (SARS)‐affected countries and to compare distinctive features of the Chinese approach to other affected Asian countries and Canada.

Method  Literature review.

Results  The realisation in March 2003 that SARS was spreading led affected countries to introduce measures such as rapid dissemination of information, early case detection and isolation, tracing and quarantining of SARS contacts, traveller screening, raising public awareness of risk and institution of stricter infection control in health care settings. SARS became a notifiable disease in China in mid‐April 2003, after which introduction of efficient nationwide control measures led to containment within 2 months. Countries differed in the timeliness of implementing control measures, the mode and extent to which these were enforced and in the resources available to do so.

Conclusion  SARS challenged the political and public health systems of all affected countries. It demanded rapid and decisive action to be taken, yet the comparison shows how difficult this was for an unknown new disease. Guangdong reacted rapidly but this pace was not continued by China for some time, which facilitated national and international spread. Once the Chinese government changed its policy, it developed an impressive control strategy involving the public which culminated in containment. The significance of timely information was perhaps the main lesson which the SARS epidemic taught.
Mathematical modelling of SARS and other infectious diseases in China: a review
Authors: Han Xiao‐Na , De Vlas Sake J. , Fang Li‐Qun , Feng Dan , Cao Wu‐Chun , Habbema J. Dik F.
Published: June 2009

Objective To give an overview of the recent history of publications on mathematical modelling of infectious diseases in the Chinese literature, and a more detailed review of the models on severe acute respiratory syndrome (SARS).

Method Literature review through the Chinese CAJ full‐text database.

Results The number of Chinese publications on mathematical modelling has at least quadrupled since the SARS epidemic in 2003. This increase not only included papers on SARS, but also on various other infectious diseases, indicating a substantial expansion of modelling experience in China. Typical problems of most studies were poor availability of data and lack of involvement of disease experts and decision‐makers rendering the studies less useful for policies on control.

Conclusions We expect that the recent experience on modelling and current better access to and exchange of epidemiological data have paved the way for a more substantial role of this discipline during possible future outbreaks of infectious diseases. By making Chinese modelling initiatives more visible to non‐Chinese readers, we hope to attract more international collaborators.
Cellular and body scale morphology of Heterocapsa huensis sp. nov. (Peridiniales, Dinophyceae) found in Hue, Vietnam
Authors: Iwataki Mitsunori , Kawami Hisae , Van Nguyen Nguyen , Luong Quang Doc , Ton That Phap , Fukuyo Yasuwo , Matsuoka Kazumi
Published: May 2009

Cellular and body scale structure of a new armored dinoflagellate Heterocapsa huensis, collected from Hue, Vietnam were investigated. Morphology of motile cell was observed by light, fluorescent and scanning electron microscopy, and body scale structure was examined by whole mounts of transmission electron microscopy. Cells of H. huensis were ellipsoid with a spherical nucleus located in the posterior and multiple pyrenoids located above the nucleus; this arrangement was similar to that of Heterocapsa pygmaea. Transmission electron microscopy revealed ultrastructure of the body scales consisted of a rounded triangular basal plate and three‐dimensional ornaments. Structure of the basal plate resembles that of Heterocapsa illdefina; however, the number of the peripheral spine is different from that of H. illdefina and this structure has never been reported from Heterocapsa species. A new Heterocapsa species, H. huensis Iwataki et Matsuoka sp. nov., is described based on positions of organelles and body scale ultrastructure.