bluuebunny/crossref_metadata_2025 huggingface dataset:
Acquired haemophilia: management of bleeds and immune therapy to eradicate autoantibodies
Authors: Holme P. A. , Brosstad F. , Tjønnfjord G. E.
Published: August 2005

Summary.  Acquired haemophilia is a rare, but often severe bleeding disorder caused by autoantibodies against a coagulation factor, usually factor VIII (FVIII). Between 1997 and 2004 we observed 14 patients (mean age of 78 years) with acquired haemophilia. The aim of the present study was to investigate the effect of activated prothrombin complex concentrate (aPCC) for bleeds and the response to corticosteroids and cyclophosphamide to eradicate the offending autoantibodies. The most common clinical presentations were severe profuse bruising (12) and haematuria (5). Ten patients were classified as idiopathic. At the time of diagnosis all patients had a very low FVIII level, and one patient also showed factor IX < 1%. High levels of antibodies to FVIII varying from 10 to 1340 Bethesda units (BU) and prolonged activated partial thromboplastin time were disclosed in all patients. Eight severe bleeds were treated with aPCC (FEIBA®) at a dosage of 70 IU kg−1 every 8 h until haemostasis. Ten patients received corticosteroids and cyclophosphamide as immunomodulatory therapy. Effective haemostasis was achieved in all bleeds after aPCC. Ten of 11 patients responded either completely or partially to the immunomodulatory regime within 6 months. Five patients achieved complete response (CR) whereas partial responses were seen in five patients. The anti‐CD20 monoclonal antibody rituximab was given to two patients in conventional doses and a CR was seen in one patient. aPCC is effective in treating acute bleeds in patients with acquired haemophilia with high inhibitor levels. The combination of oral corticosteroids and cyclophosphamide seems to be effective to eradicate the inhibitor.
Congenital deficiency of factor XIII caused by two missense mutations in a Dutch family
Authors: Onland W. , Böing A. N. , Meijer A. B. , Schaap M. C. L. , Nieuwland R. , Haasnoot K. , Sturk A. , Peters M.
Published: August 2005

Summary.  We present the clinical, biochemical and genomic findings of a family with congenital factor XIII (FXIII) deficiency. Congenital FXIII deficiency is a very rare autosomal recessive bleeding disorder, characterized by umbilical cord bleeding at birth and spontaneous intracranial haemorrhage. Routine clotting tests are normal, which may delay the diagnosis, leading to an increased chance of severe sequelae. The propositus and her brother, known with haemorrhagic diathesis, were found to be compound heterozygous with a known missense mutation (1050 G → T transversion in exon 7, Val316Phe substitution) and a novel mutation 889 G → A in exon 6, which predicts a Gly262Glu substitution. As these mutations were known in the family, DNA obtained from cord blood of the youngest sister was analysed for mutations in exons 6 and 7 only. We postulate that the diagnosis was facilitated by determining the two different mutations in the genotype of this family. The analysis showed that she was heterozygous for the exon 7 mutation. Hence, she was not at risk of experiencing haemorrhagic diathesis. This diagnosis avoided the administration of FXIII concentrate to the newborn.
Major surgery in a severe haemophilia A patient with high titre inhibitor: use of the thrombin generation test in the therapeutic decision
Authors: Dargaud Y. , Lienhart A. , Meunier S. , Hequet O. , Chavanne H. , Chamouard V. , Marin S. , Negrier C.
Published: August 2005

Summary.  In haemophilia patients with inhibitor, elective orthopaedic surgery is usually performed under recombinant activated factor VII (rFVIIa). We report here the case of a severe haemophilia A patient with a high inhibitor who needed a bilateral total knee arthroplasty. Recombinant FVIIa was previously shown to be ineffective for the treatment of muscle and joint bleedings, and he had a history of excessive postoperative bleeding under activated prothrombin complex concentrate (APCC). Thrombin generation test (TGT) was used to assess the efficacy of Factor Eight Inhibitor Bypassing Activity (FEIBATM). Insufficient correction of thrombin‐generating capacity was observed after administration of 75 U kg−1 FEIBATM. In a multidisciplinary environment, a bilateral total knee arthroplasty was performed using a protocol combining immunoadsorption of inhibitors preoperatively associated with FVIII replacement during a first phase followed by FEIBATM when the inhibitor reappeared. To our knowledge this is the first direct application of TGT in the management of haemophilia patients with inhibitor, which indicated that a sequential use of immunoadsorption, FVIII and FEIBATM was the most appropriate treatment to perform this major elective surgery. This case demonstrates that this combined protocol can be safely used to cover major surgery in inhibitor patients. In addition, it also suggests that TGT may have a major contribution in the decision‐making process of the most adapted therapy for the treatment of such high‐risk patients.
Heterologous rRNA gene expression: internal fragmentation of Sciara coprophila 28S rRNA within microinjected Xenopus laevis oocytes
Authors: Basile‐Borgia A. E. , Dunbar D. A. , Ware V. C.
Published: August 2005

Species‐specific pre‐rRNA processing variations may result in fragmented 18S, 5.8S and 28S rRNAs. Some insect 5.8S and 28S rRNAs are further cleaved, creating within a ‘hidden break’ or ‘gap’. We investigated the specificity of the processing mechanism by microinjecting Sciara coprophila (fungus fly) rDNA into Xenopus laevis oocytes to examine insect rRNA maturation within a cell where endogenous rRNAs are not cleaved at homologous sites. Results confirm insect rDNA transcription and pre‐28S rRNA fragmentation, demonstrating that fly‐specific processing machinery is not required. Instead, oocytes may provide required accessory factors, suggesting that the insect gap processing mechanism is served by an evolutionarily conserved apparatus. Alternatively, these results may suggest that processing in some lineages is an autocatalytic property of the rRNA.
Orthodontic management of orofacial problems in young people with impairments: review of the literature and case reports
Authors: HOBSON R. S. , NUNN J. H. , COZMA I.
Published: August 2005

Summary.  Objective. The aim of this paper is to present a series of cases illustrating possible options for the management of malocclusions in a group of young people with impairments.

Design. The study took the form of a case series.

Methods. A review of the literature is presented and a series of illustrative cases are shown to indicate that orthodontic treatment is possible in patients with a range of impairments

Results. Five children with varying intellectual and/or physical impairments, and a malocclusion that resulted in trauma or increased disability, are presented

Conclusion. The risks and benefits of the procedures, and the anticipated oral health outcomes, need to be considered carefully in this group of children.
Epidermolysis bullosa and dental developmental age
Authors: LIVERSIDGE H. M. , KOSMIDOU A. , HECTOR M. P. , ROBERTS G. J.
Published: August 2005

Summary. Objectives. The dental development of permanent mandibular teeth in a small group of children with dystrophic epidermolysis bullosa (DEB) was assessed from radiographs and compared to a healthy, age‐and‐sex‐matched control group.

Methods. This was a retrospective radiographic cross‐sectional study. The sample consisted of a group of 44 children aged between 4 and 15 years with DEB and healthy, age‐and‐sex‐matched controls. Two quantitative methods of assessing tooth formation were used: (1) a combination of information about tooth length and apex width; and (2) the use of tooth length to predict age. Panoramic radiographs were digitized in order to determine tooth length and apex width. Dental age was calculated, and the difference with real age was tested with Student's t‐test.

Results. The dentition of both the DEB and control groups was slightly delayed. Using the first method, the delay was 0·34 ± 0·87 years for the DEB group and 0·29 ± 0·97 years for the control group. Using the second method, the delay was 0·49 ± 1·18 years for the DEB group and 0·23 ± 0·62 years for the control group. This delay was not statistically significant for either method.

Conclusions. The dental formation of permanent mandibular teeth in the group of children with DEB was not significantly different to that found in the control group.
A case of Tourette syndrome presenting with oral self‐injurious behaviour
Authors: LEKSELL E. , EDVARDSON S.
Published: August 2005

Summary. Self‐injurious behaviour (SIB) is deliberate harm to the body without suicidal intent, and the condition occurs in a number of psychiatric, behavioural and developmental disorders. This case report describes a 4‐year‐old female with SIB who presented to a paediatric dentist after the self‐extraction of teeth as a result of oral motor tics. The girl repetitively ground her teeth in a monophasic lateral motion that resulted in luxation of her maxillary right primary canine, and produced generalized oral and facial pain. The parents consulted the dentist about their child's complaint of toothache. The oral findings were unexcephonable except for a mobile primary canine, but there was a history of unusual behaviour including hyperactivity, and after multidisciplinary consultation and exclusion of other systemic diseases, the subject was diagnosed as suffering from Tourette syndrome (TS). Preventive treatment using a dental splint was provided. Noncontingent reinforcement therapy was successfully used to diminish the subject's SIB.
External cervical resorption of a primary canine
Authors: RODD H. D. , NAIK S. , CRAIG G. T.
Published: August 2005

Summary. The authors describe the case of a 3‐year‐old boy who presented with a mobile right maxillary primary canine. Clinical examination revealed this tooth to have an abnormally large crown, which appeared to have sustained a crown–root fracture. Periodontal probing depths of 5 mm were detected around the tooth. Radiographically, there was a marked constriction at the cementoenamel junction with associated alveolar rarefaction. Both upper primary canines were subsequently removed under general anaesthetic and the right canine was subject to histopathological investigation. A diagnosis of external cervical resorption was made. A review of the literature confirmed this to be a very unusual case presentation.
Injuries to the head, face, mouth and neck in physically abused children in a community setting
Authors: CAIRNS A. M. , MOK J. Y. Q. , WELBURY R. R.
Published: August 2005

Summary. Objectives. The aims of the present study were to identify the incidence of orofacial injuries found within a cohort of physically abused children, and examine demographic data surrounding the alleged perpetrator, the location in which the alleged assault occurred, the mechanism of injury and the actual orofacial injury incurred.

Methods. The research took the form of a retrospective study of clinical case records of children with suspected physical abuse from 1 June 1998 to 31 May 2003. Seven hundred and fifty case records were identified and 390 (46·7%) were available for data extraction.

Results. Fifty‐nine per cent (n = 230) of children had signs of abuse on the head, face or neck. The alleged perpetrator was the mother in 104 cases (26·7%), the father in 100 (25·6%) and mother's partner in 49 other cases (12·6%). More than half (53·3%) of the alleged abuse occurred in the child's home; in 32·3% of cases, the location was not recorded. Other locations included outside in a public place, school and at the home of the alleged abuser. Some 23·4% (n = 54) had been punched or slapped around the head, neck or face, 17·4% (n = 40) had been struck by an object, and 15·2% (n = 35) had allegedly sustained multiple modes of injury. Bruising to the head, neck or face was seen in 95·2% (n = 219) of children, and 32·6% (n = 75) had abrasions; 65·2% (n = 150) of the bruises and 22·9% (n = 53) of the abrasions were on the face.

Conclusions. Fifty‐nine per cent of physically abused children in the present cohort had orofacial signs of abuse which would be easily visible to a dental practitioner. The commonest injuries were bruises and abrasions. This concurs with previous reports in the literature and highlights the important role of dental practitioners in the recognition of children who have been abused.
Distribution of Urocortin 2 in Various Tissues of the Rat
Authors: Yamauchi N. , Otagiri A. , Nemoto T. , Sekino A. , Oono H. , Kato I. , Yanaihara C. , Shibasaki T.
Published: August 2005

Urocortin (Ucn) 2 is a new member of the corticotrophin‐releasing hormone (CRH) neuropeptide family that is expressed in the central nervous system and peripheral tissues. However, the expression levels of Ucn 2 in various tissues of the rat remains unclear. Thus, the aim of the present study was to characterise the expression of Ucn 2 in the various tissues of the rat. Reverse transcriptase‐polymerase chain reaction analysis demonstrated that Ucn 2 mRNA is expressed in the hypothalamus, pituitary, adrenal, stomach, skin, ovary, uterus and skeletal muscle. Histologically, Ucn 2 mRNA and Ucn 2‐like immunoreactivity (LI) were demonstrated in both the anterior and intermediate lobes of the pituitary, but not detected in the posterior lobe. Furthermore, all Ucn 2‐positive cells in the anterior and intermediate lobes were also positive for β‐endorphin. Ucn 2 mRNA was detected in the adrenal cortex and medulla although Ucn 2‐LI was only found in the adrenal medulla. High‐performance liquid chromatography analysis of hypothalamic, pituitary, and adrenal extracts showed that the main Ucn 2‐LI peak occurred at the same molecular size as that of synthetic Ucn 2. These results suggest that Ucn 2 is synthesised in various tissues, including the anterior and intermediate lobes of the pituitary and the adrenal.
Resident–Intruder Trait Aggression is Associated with Differences in Lysine Vasopressin and Serotonin Receptor 1A (5‐HT1A) mRNA Expression in the Brain of Pre‐Pubertal Female Domestic Pigs (Sus scrofa)
Authors: D'Eath R. B. , Ormandy E. , Lawrence A. B. , Sumner B. E. H. , Meddle S. L.
Published: August 2005

Aggressive behaviour exhibited by domestic pigs following encounters with unfamiliar individuals is a serious welfare and economical problem. Aggression resulting in skin lesions is similarly prevalent in prepubertal pigs of either sex. Little is known about the neural circuits and neuropeptides that control aggression in the pig. Because there is evidence for the involvement of the vasopressin and serotonergic systems in the regulation of aggressive behaviour in male mammals, we sought differences using quantitative in situ hybridisation of vasopressin and serotonin 1A receptor (5‐HT1A) mRNA expression within specific brain regions of aggressive and nonaggressive prepubertal female pigs. The number of cells expressing vasopressin mRNA was significantly higher in aggressive pigs in the medial amygdala, lateral septum (LS) and showed a similar trend in the bed nucleus of the stria terminalis (BnST) but not the paraventricular nucleus (PVN) or supraoptic nucleus. The 5‐HT1A receptor was widely expressed through the porcine brain and a significantly lower intensity (silver grain density) of 5‐HT1A mRNA expression was observed in the BnST. In the medial amygdala and LS fewer cells expressed 5‐HT1A mRNA in aggressive pigs but no differences were found in the PVN. In the absence of inbred strains or selection lines, these findings have shown that prior identification of phenotypic behavioural extremes in a population in advance of neural studies is a useful technique. Moreover, these findings support a central role for vasopressin and serotonin in the mediation of high trait aggression in prepubertal female pigs.
Phenotypic variation in Galerida larks in Morocco: the role of history and natural selection
Authors: GUILLAUMET A. , CROCHET P.‐A. , GODELLE B.
Published: August 2005

The relative influences of history, natural selection and hybridization in shaping phenotypic variation in closely related taxa is a crucial issue in current evolutionary biology. In this study, we used as a model two sibling but paradoxically highly variable species of larks (Galerida theklae and Galerida cristata) of Morocco to separate the impacts of these evolutionary forces. In the former species, variation is manifested mainly in colouration, while in the latter, variation also encompasses bill size and shape. Mitochondrial and nuclear DNA sequencing were used to identify the historical relationships among the subspecies and species. According to our analyses, G. cristata and G. theklae diverged about 3.7 million years ago (Ma), and we found no evidence for a role of hybridization in maintaining their similarity. In G. theklae, there was no further subdivision, while in G. cristata two major mtDNA groups were identified (divergence ∼1.1 Ma). These two lineages are parapatric and regroup, respectively, the three short‐billed subspecies [G. (cristata) cristata] and the two long‐billed subspecies [G. (cristata) randonii]. Patterns of morphological variation were then contrasted to this pattern of neutral relationships: we found that G. (c.) cristata was morphologically more similar to G. theklae than to G. (c.) randonii. Overall, these results point towards the prominent role of (i) natural selection and/or phenotypic plasticity in adapting the plumage to local conditions and (ii) natural selection in combination with historical isolation in driving the divergence in size and bill morphology in the crested larks.
Invasion success and genetic diversity of introduced populations of guppiesPoecilia reticulatain Australia
Authors: LINDHOLM ANNA K. , BREDEN FELIX , ALEXANDER HEATHER J. , CHAN WOON‐KHIONG , THAKURTA SUMITA G. , BROOKS ROBERT
Published: August 2005

High genetic diversity is thought to characterize successful invasive species, as the potential to adapt to new environments is enhanced and inbreeding is reduced. In the last century, guppies,Poecilia reticulata,repeatedly invaded streams in Australia and elsewhere. Quantitative genetic studies of one Australian guppy population have demonstrated high additive genetic variation for autosomal and Y‐linked morphological traits. The combination of colonization success, high heritability of morphological traits, and the possibility of multiple introductions to Australia raised the prediction that neutral genetic diversity is high in introduced populations of guppies. In this study we examine genetic diversity at nine microsatellite and one mitochondrial locus for seven Australian populations. We used mtDNA haplotypes from the natural range of guppies and from domesticated varieties to identify source populations. There were a minimum of two introductions, but there was no haplotype diversity within Australian populations, suggesting a founder effect. This was supported by microsatellite markers, as allelic diversity and heterozygosity were severely reduced compared to one wild source population, and evidence of recent bottlenecks was found. Between Australian populations little differentiation of microsatellite allele frequencies was detected, suggesting that population admixture has occurred historically, perhaps due to male‐biased gene flow followed by bottlenecks. Thus success of invasion of Australia and high additive genetic variance in Australian guppies are not associated with high levels of diversity at molecular loci. This finding is consistent with the release of additive genetic variation by dominance and epistasis following inbreeding, and with disruptive and negative frequency‐dependent selection on fitness traits.
Genetic structure of the whitefly Bemisia tabaci in the Asia–Pacific region revealed using microsatellite markers
Authors: DE BARRO P. J.
Published: August 2005

Bemisia tabaci (Hemiptera: Aleyrodidae) is a haplo‐diploid species of sap‐feeding insect belonging to the group of insects commonly known as whiteflies. From earlier analyses of mitochondrial and ribosomal markers it has been concluded that in the Asia–Pacific region there were three major indigenous races as well as a large collection of genotypes with no clear association with any race. This new study uses 15 microsatellite loci and demonstrates that the indigenous Asia–Pacific genotypes can be split into six genetic populations with little or no gene flow between them. These bare only superficial similarity to the mitochondrial and ribosomal defined races. Moreover, four of the six can be further split into two subpopulations that again show little evidence gene flow between them. While the patterns reflect a strong geographical structure, physical barriers alone cannot explain all the observed structure. Differential host‐plant utilization explained some of the substructure, but could not explain the overall structure. The roles of mating interference and Wolbachia in developing the genetic structure are considered. The lack of gene flow between genetic populations and some subpopulations further suggests that the barriers were either sufficiently impermeable to immigration or that reproductive isolation and competitive interactions were sufficiently strong to prevent gene flow. If the latter is the case, it suggests that there may be as many as 10 morphologically indistinguishable species indigenous to the Asia–Pacific region.
Species status and phylogeography of two closely related Coptolabrus species (Coleoptera: Carabidae) in South Korea inferred from mitochondrial and nuclear gene sequences
Authors: ZHANG A. B. , KUBOTA K. , TAKAMI Y. , KIM J. L. , KIM J. K. , SOTA T.
Published: August 2005

We investigated the species status and intraspecific phylogeography in South Korea of two ground beetle species, Coptolabrus jankowskii and Coptolabrus smaragdinus (Coleoptera: Carabidae), using statistical parsimony networks and nested clade analyses based on sequences from the mitochondrial cytochrome oxidase subunit I (COI) and nuclear phosphoenolpyruvate carboxykinase (PepCK) and wingless (Wg) genes. Although traditional parsimony tree construction generally failed to resolve interspecific relationships and construct biologically meaningful genealogies, analysis using statistical parsimony networks yielded statistically significant inter‐ and intraspecific genealogical structures. We found that although these two species represent a notable case of trans‐species polymorphisms in both mitochondrial and nuclear gene sequences, their status as separate species was evidenced by the nonrandom association between species and nested clades at various nesting levels. The exceptional occurrence of shared identical or very similar COI sequences was considered to be the result of introgressive hybridization. In addition, range expansion and fragmentation events across the Korean Peninsula and adjacent islands were inferred from nested clade phylogeographical analyses. The COI gene revealed the geographical divergence of major eastern and western clades and historical biogeographical events within each major clade, whereas the nuclear PepCK gene, which did not reveal corresponding east–west clades, indicated past fragmentation and range expansion across wide areas that may have been the result of older biogeographical events. Thus, phylogeographical inferences drawn from analyses of mitochondrial and nuclear genes can reveal different and potentially complementary information about phylogeographical processes.
A genome‐wide screen identifies a Bordetella type III secretion effector and candidate effectors in other species
Authors: Panina Ekaterina M. , Mattoo Seema , Griffith Natasha , Kozak Natalia A. , Yuk Ming H. , Miller Jeff F.
Published: August 2005

Bordetella bronchiseptica utilizes a type III secretion system (TTSS) for induction of non‐apoptotic cytotoxicity in host cells and modulation of host immunity. The identity of Bordetella TTSS effectors, however, has remained elusive. Here we report a genome‐wide screen for TTSS effectors based on shared biophysical and functional characteristics of class I chaperones and their frequent colocalization with TTSS effectors. When applied to B. bronchiseptica, the screen identified the first TTSS chaperone‐effector locus, btcA‐bteA, and we experimentally confirmed its function. Expression of bteA is co‐ordinated with expression of TTSS apparatus genes, BteA is secreted through the TTSS of B. bronchiseptica, it is required for cytotoxicity towards mammalian cells, and it is highly conserved in the human‐adapted subspecies B. pertussis and B. parapertussis. Transfection of bteA into epithlieal cells results in rapid cell death, indicating that BteA alone is sufficient to induce potent cytotoxicity. Finally, an in vitro interaction between BteA and BtcA was demonstrated. The search for TTSS chaperones and effectors was then expanded to other bacterial genomes, including mammalian and insect pathogens, where we identified a large number of novel candidate chaperones and effectors. Although the majority of putative effectors are proteins of unknown function, several have similarities to eukaryotic protein domains or previously identified effectors from other species.
Chromosomal DNA transfer in Mycobacterium smegmatis is mechanistically different from classical Hfr chromosomal DNA transfer
Authors: Wang Jun , Karnati Pavan K. , Takacs Carter M. , Kowalski Joseph C. , Derbyshire Keith M.
Published: August 2005

Classical conjugal DNA transfer of chromosomal DNA in bacteria requires the presence of a cis‐acting site, oriT, in the chromosome. Acquisition of an oriT occurs if a conjugative plasmid integrates into the chromosome to form an Hfr donor strain, which can transfer extensive regions of chromosomal DNA. Because oriT sequences are unique, and because transfer occurs in a 5′ to 3′ direction, the frequency with which a particular gene is inherited by the recipient depends on the gene's location: those closest to the 3′ side of oriT are transferred most efficiently. In addition, as the entire chromosome must be transferred to regenerate oriT, Hfr transconjugants never become donors. Here we describe novel aspects of a chromosomal DNA transfer system in Mycobacterium smegmatis. We demonstrate that there are multiple transfer initiations from a donor chromosome and, as a result, the inheritance of any gene is location‐independent. Transfer is not contiguous; instead, multiple non‐linked segments of DNA can be inherited in a recipient. However, we show that, with appropriate selection, segments of DNA at least 266 kb in length can be transferred. In further contrast to Hfr transfer, transconjugants can become donors, suggesting that the recipient chromosome contains multiple cis‐acting sequences required for transfer, but lacks the trans‐acting transfer functions. We exploit these observations to map a donor‐determining locus in the M. smegmatis chromosome using genetic linkage analysis. Together, these studies further underline the unique nature of the M. smegmatis chromosomal transfer system.
CsgA is a pathogen‐associated molecular pattern of Salmonella enterica serotype Typhimurium that is recognized by Toll‐like receptor 2
Authors: Tükel Çagla , Raffatellu Manuela , Humphries Andrea D. , Wilson R. Paul , Andrews‐Polymenis Helene L. , Gull Tamara , Figueiredo Josely F. , Wong Michelle H. , Michelsen Kathrin S. , Akçelik Mustafa , Adams L. Garry , Bäumler Andreas J.
Published: August 2005

Knowledge about the origin and identity of the microbial products recognized by the innate immune system is important for understanding the pathogenesis of inflammatory diseases. We investigated the potential role of Salmonella enterica serotype Typhimurium fimbriae as pathogen‐associated molecular patterns (PAMPs) that may stimulate innate pathways of inflammation. We screened a panel of 11 mutants, each carrying a deletion of a different fimbrial operon, for their enteropathogenicity using the calf model of human gastroenteritis. One mutant (csgBA) was attenuated in its ability to elicit fluid accumulation and GROα mRNA expression in bovine ligated ileal loops. The mechanism by which thin curled fimbriae encoded by the csg genes contribute to inflammation was further investigated using tissue culture. The S. Typhimurium csgBA mutant induced significantly less IL‐8 production than the wild type in human macrophage‐like cells. Purified thin curled fimbriae induced IL‐8 expression in human embryonic kidney (HEK293) cells transfected with Toll‐like receptor (TLR) 2/CD14 but not in cells transfected with TLR5, TLR4/MD2/CD14 or TLR11. Fusion proteins between the major fimbrial subunit of thin curled fimbriae (CsgA) and glutathione‐S‐transferase (GST) elicited IL‐8 production in HEK293 cells transfected with TLR2/CD14. Proteinase K treatment abrogated IL‐8 production elicited in these cells by GST–CsgA, but not by synthetic lipoprotein. GST–CsgA elicited more IL‐6 production than GST in bone marrow‐derived macrophages from TLR2+/+ mice, while there was no difference in IL‐6 secretion between GST–CsgA and GST in macrophages from TLR2–/– mice. These data suggested that CsgA is a PAMP that is recognized by TLR2.
Dual regulatory pathways integrating the RcsC–RcsD–RcsB signalling system control enterohaemorrhagic Escherichia coli pathogenicity
Authors: Tobe Toru , Ando Hiroki , Ishikawa Hiroko , Abe Hiroyuki , Tashiro Kosuke , Hayashi Tetsuya , Kuhara Satoru , Sugimoto Nakaba
Published: August 2005

Bacterial pathogenesis is strictly regulated in response to changes in environmental conditions. A His–Asp phosphorelay system consisting of a sensor kinase and response regulator is used by Gram‐positive and Gram‐negative bacteria to control gene expression in response to environmental stimuli. We screened His–Asp phosphorelay systems for their effect on virulence expression in enterohaemorrhagic Escherichia coli (EHEC), and found rcsD or rcsB overexpression enhanced locus for enterocyte effacement (LEE) gene transcription and adherence to Caco‐2 cells through transcriptional activation of the ler regulatory gene. An EHEC‐specific regulator GrvA, encoded by ECs1274, was required for ler transcription activation by RcsB. Furthermore, GrvA activated ler transcription in E. coli K12. Stimulation of the RcsDCB regulatory system by RcsF overexpression slightly increased EspB expression in the wild type but not the ECs1274 mutant. However, EspB expression in an rcsB deletion mutant increased compared with wild type, suggesting that RcsB negatively regulates LEE gene expression and that active RcsB protein is present under normal growth conditions. Deletion of pchA, which encodes a positive regulator for ler, abolished the effect of the rcsB deletion, suggesting that pchA mediated the negative RcsB effect. pchA transcript levels decreased when RcsB expression increased. Thus, LEE gene transcription may be regulated by RcsB through two oppositely regulated O157‐specific regulators, PchA and GrvA.
The Helicobacter pylori MutS protein confers protection from oxidative DNA damage
Authors: Wang Ge , Alamuri Praveen , Humayun M. Zafri , Taylor Diane E. , Maier Robert J.
Published: August 2005

The human gastric pathogenic bacterium Helicobacter pylori lacks a MutSLH‐like DNA mismatch repair system. Here, we have investigated the functional roles of a mutS homologue found in H. pylori, and show that it plays an important physiological role in repairing oxidative DNA damage. H. pylori mutS mutants are more sensitive than wild‐type cells to oxidative stress induced by agents such as H2O2, paraquat or oxygen. Exposure of mutS cells to oxidative stress results in a significant (∼10‐fold) elevation of mutagenesis. Strikingly, most mutations in mutS cells under oxidative stress condition are G:C to T:A transversions, a signature of 8‐oxoguanine (8‐oxoG). Purified H. pylori MutS protein binds with a high specific affinity to double‐stranded DNA (dsDNA) containing 8‐oxoG as well as to DNA Holliday junction structures, but only weakly to dsDNA containing a G:A mismatch. Under oxidative stress conditions, mutS cells accumulate higher levels (approximately threefold) of 8‐oxoG DNA lesions than wild‐type cells. Finally, we observe that mutS mutant cells have reduced colonization capacity in comparison to wild‐type cells in a mouse infection model.
Requirement of the dephospho‐form of enzyme IIANtr for derepression of Escherichia coli K‐12 ilvBN expression
Authors: Lee Chang‐Ro , Koo Byoung‐Mo , Cho Seung‐Hyon , Kim Yu‐Jung , Yoon Mi‐Jeong , Peterkofsky Alan , Seok Yeong‐Jae
Published: August 2005

While the proteins of the phosphoenolpyruvate:carbohydrate phosphotransferase system (carbohydrate PTS) have been shown to regulate numerous targets, little such information is available for the nitrogen‐metabolic phosphotransferase system (nitrogen‐metabolic PTS). To elucidate the physiological role of the nitrogen‐metabolic PTS, we carried out phenotype microarray (PM) analysis with Escherichia coli K‐12 strain MG1655 deleted for the ptsP gene encoding the first enzyme of the nitrogen‐metabolic PTS. Together with the PM data, growth studies revealed that a ptsN (encoding enzyme IIANtr) mutant became extremely sensitive to leucine‐containing peptides (LCPs), while both ptsP (encoding enzyme INtr) and ptsO (encoding NPr) mutants were more resistant than wild type. The toxicity of LCPs was found to be due to leucine and the dephospho‐form of enzyme IIANtr was found to be necessary to neutralize leucine toxicity. Further studies showed that the dephospho‐form of enzyme IIANtr is required for derepression of the ilvBN operon encoding acetohydroxy acid synthase I catalysing the first step common to the biosynthesis of the branched‐chain amino acids.
PchR‐box recognition by the AraC‐type regulator PchR of Pseudomonas aeruginosa requires the siderophore pyochelin as an effector
Authors: Michel Laurent , González Nicolas , Jagdeep Steve , Nguyen‐Ngoc Tu , Reimmann Cornelia
Published: August 2005

Under iron limitation, the opportunistic human pathogen Pseudomonas aeruginosa produces the siderophore pyochelin. When secreted into the extracellular environment, pyochelin complexes ferric ions and delivers them, via the outer membrane receptor FptA, to the bacterial cytoplasm. Extracellular pyochelin also acts as a signalling molecule, inducing the expression of pyochelin biosynthesis and uptake genes by a mechanism involving the AraC‐type regulator PchR. We have identified a 32 bp conserved sequence element (PchR‐box) in promoter regions of pyochelin‐controlled genes and we show that the PchR‐box in the pchR‐pchDCBA intergenic region is essential for the induction of the pyochelin biosynthetic operon pchDCBA and the repression of the divergently transcribed pchR gene. PchR was purified as a fusion with maltose‐binding protein (MBP). Mobility shift assays demonstrated specific binding of MBP‐PchR to the PchR‐box in the presence, but not in the absence of pyochelin and iron. PchR‐box mutations that interfered with pyochelin‐dependent regulation in vivo, also affected pyochelin‐dependent PchR‐box recognition in vitro. We conclude that pyochelin, probably in its iron‐loaded state, is the intracellular effector required for PchR‐mediated regulation. The fact that extracellular pyochelin triggers this regulation suggests that the siderophore can enter the cytoplasm.
Diurnal and seasonal variation in root xylem embolism in neotropical savanna woody species: impact on stomatal control of plant water status
Authors: DOMEC J‐C. , SCHOLZ F. G. , BUCCI S. J. , MEINZER F. C. , GOLDSTEIN G. , VILLALOBOS‐VEGA R.
Published: August 2005

Vulnerability to water‐stress‐induced embolism and variation in the degree of native embolism were measured in lateral roots of four co‐occurring neotropical savanna tree species. Root embolism varied diurnally and seasonally. Late in the dry season, loss of root xylem conductivity reached 80% in the afternoon when root water potential (Ψroot) was about −2.6 MPa, and recovered to 25–40% loss of conductivity in the morning when Ψroot was about −1.0 MPa. Daily variation in Ψroot decreased, and root xylem vulnerability and capacitance increased with rooting depth. However, all species experienced seasonal minimum Ψroot close to complete hydraulic failure independent of their rooting depth or resistance to embolism. Predawn Ψroot was  lower  than  Ψsoil when  Ψsoil was  relatively  high  (>−0.7 MPa) but became less negative than Ψsoil later in the dry season, consistent with a transition from a disequilibrium between plant and soil Ψ induced by nocturnal transpiration to one induced by hydraulic redistribution of water from deeper soil layers. Shallow longitudinal root incisions external to the xylem prevented reversal of embolism overnight, suggesting that root mechanical integrity was necessary for recovery, consistent with the hypothesis that if embolism is a function of tension, refilling may be a function of internal pressure imbalances. All species shared a common relationship in which maximum daily stomatal conductance declined linearly with increasing afternoon loss of root conductivity over the course of the dry season. Daily embolism and refilling in roots is a common occurrence and thus may be an inherent component of a hydraulic signaling mechanism enabling stomata to maintain the integrity of the hydraulic pipeline in long‐lived structures such as stems.
Secondary metabolites influence Arabidopsis/Botrytis interactions: variation in host production and pathogen sensitivity
Authors: Kliebenstein Daniel J. , Rowe Heather C. , Denby Katherine J.
Published: August 2005

Numerous studies have suggested that plant/pathogen interactions are partially mediated via plant secondary metabolite production and corresponding pathogen tolerance. However, there are inconsistent reports on the ability of particular compounds to provide resistance to a pathogen. Most of these studies have focused on individual isolates of a given pathogen, suggesting that pathogens vary in their sensitivity to plant‐produced toxins. We tested variability in virulence among pathogen isolates, and the impact on this by plant production of, and pathogen tolerance to, secondary metabolites. Botrytis cinerea isolates showed differing sensitivity to purified camalexin, and camalexin‐sensitive isolates produced larger lesions on camalexin‐deficient Arabidopsis genotypes than on the wild type. In contrast, the camalexin‐insensitive isolate produced lesions of similar size on wild‐type and camalexin‐deficient Arabidopsis. Additional analysis with Arabidopsis secondary metabolite biosynthetic mutants suggests that Botrytis also has variable sensitivity to phenylpropanoids and glucosinolates. Furthermore, Botrytis infection generates a gradient of secondary metabolite responses emanating from the developing lesion, with the Botrytis isolate used determining the accumulation pattern. Collectively, our results indicate that Arabidopsis/Botrytis interactions are influenced at the metabolic level by variations in toxin production in the host and sensitivity in the pathogen.
AtDEK1 is essential for specification of embryonic epidermal cell fate
Authors: Johnson Kim L. , Degnan Kathryn A. , Ross Walker J. , Ingram Gwyneth C.
Published: August 2005

The specification of epidermal (L1) identity occurs early during plant embryogenesis. Here we show that, in Arabidopsis, AtDEK1 encodes a key component of the embryonic L1 cell‐layer specification pathway. Loss of AtDEK1 function leads to early embryo lethality characterized by a severe loss of cell organization in the embryo proper and abnormal cell divisions within the suspensor. Markers for L1 identity, ACR4 and ATML1, are not expressed in homozygous mutant embryos. In order to clarify the function of AtDEK1 further, an RNAi knockdown approach was used. This allowed embryos to partially complete embryogenesis before losing AtDEK1 activity. Resulting seedlings showed a specific loss of epidermal cell identity within large portions of the cotyledons. In addition, meristem structure and function was systematically either reduced or entirely lost. AtDEK1 expression is not restricted to the L1 epidermal cell layer at any stage in development. This is consistent with AtDEK1 playing an upstream role in the continuous generation or interpretation of positional information required for epidermal specification. Our results not only identify a specific role for AtDEK1 during embryogenesis, but underline the potential key importance of L1 specification at the globular stage for subsequent progression through embryogenesis.
The effect of malaria on mortality in a cohort of HIV‐infected Ugandan adults
Authors: Quigley Maria A. , Hewitt Kirsten , Mayanja Billy , Morgan Dilys , Eotu Henry , Ojwiya Amato , Whitworth James A. G.
Published: August 2005

Objectives  To investigate the effects of malaria parasitaemia and clinical malaria on mortality in HIV seropositive and seronegative adults.

Methods  A cohort of adults in rural Uganda were followed from 1990 to 1998. Participants attended routine clinic visits every 3 months and also when sick (interim visits). Information was collected on HIV serostatus, history of fever, current fever and malaria parasite levels. Malaria was categorized as any parasitaemia, significant parasitaemia (≥1.25 × 106 parasites/ml at routine or ≥50 parasites per 200 white blood cells at interim visits) or clinical malaria. The effect of malaria on all‐cause mortality was assessed using Cox models.

Results  The 222 HIV seropositive participants made 2762 routine visits and 1522 interim visits. During follow‐up, of the 211 participants with full records, 69% had at least one episode of parasitaemia, 51% experienced significant parasitaemia and 28% had clinical malaria. There were 90 deaths in 922 person‐years of observation. There were no significant associations between numbers of visits with any parasitaemia, significant parasitaemia or clinical malaria on mortality rates. The highest mortality rates were observed in those making four or more routine visits with significant parasitaemia [adjusted mortality rate ratio (RR) 3.27 compared with those making 0 such visits; P = 0.078] and those making two or more visits with clinical malaria (adjusted RR 2.23; P = 0.093). There was no significant interaction between any malaria category and HIV serostatus.

Conclusion  We found no evidence of a strong detrimental effect of malaria on all‐cause mortality in HIV seropositive adults in this setting.
Towards empirical description of malaria seasonality in southern Africa: the example of Zimbabwe
Authors: Mabaso M. L. H. , Craig M. , Vounatsou P. , Smith T.
Published: August 2005

Background  Quantitative description and mapping of malaria seasonality is important for timely spatial targeting of interventions and for modelling malaria risk. There is a need for seasonality models that predict quantitative variation in transmission between months.

Methods  We use Zimbabwe as an example for developing an empirical map of malaria seasonality. We describe the relationship between seasonality in malaria and environmental covariates for the period 1988–1999, by fitting a spatial‐temporal regression model within a Bayesian framework to provide smoothed maps of the seasonal trend. We adapt a seasonality concentration index used previously for rainfall to quantify malaria case load during the peak transmission season based on monthly values.

Results  Combinations of mean monthly temperature (range 28–32 °C), maximum temperature (24–28 °C) and high rainfall provide suitable conditions for seasonal transmission. High monthly maximum and mean monthly minimum temperatures limit months of high transmission. The intensity of seasonal transmission was highest in the north western part of the country from February to May with the peak in April and lowest in the whole country from July to December. The north western lowlands had the highest concentration of malaria cases (>25%) followed by some districts in the north central and eastern part with a moderate concentration of cases (20–25%). The central highlands and south eastern part of the country had the lowest concentration of malaria cases (<20%). This pattern was closely associated to the geographic variation in the seasonality of climatic covariates particularly rainfall and temperature.

Conclusions  Our modelling approach quantifies the geographical variation in seasonal trend and the concentration of cases during the peak transmission season and therefore has potential application in malaria control. The use of a covariate adjusted empirical model may prove useful for predicting the seasonal risk pattern across southern Africa.
The effect of micronutrient supplementation on treatment outcome in patients with pulmonary tuberculosis: a randomized controlled trial in Mwanza, Tanzania
Authors: Range Nyagosya , Andersen Åse B. , Magnussen Pascal , Mugomela Apolinary , Friis Henrik
Published: August 2005

Objective  The aim of the study was to assess the effects of micronutrient supplementation on culture conversion in tuberculosis (TB) patients.

Design  The study was a randomized, double‐blind placebo‐controlled 2 × 2 trial of zinc and multi‐micronutrient (MMN) supplementation in pulmonary TB patients in Tanzania.

Results  A total of 499 pulmonary TB patients were included in the trial after being confirmed sputum‐positive by microscopy or culture. At 8 weeks, 25% were sputum‐smear positive but only 11% were culture‐positive (P < 0.0001). No significant differences were observed in culture conversion rate among those allocated to MMN or placebo (89.5 vs. 86.2%, P = 0.29) at 8 weeks, although at week 4 those allocated to MMN had a slightly reduced culture conversion rate (42.8 vs. 52.8%, P = 0.058). Zinc had no effects on culture conversion. MMN increased weight gain by 0.78 kg [95% confidence interval (CI): 0.12–1.43] at week 8, while zinc supplementation had no effect. The effects of MMN and zinc did not interact and neither MMN nor zinc interacted with human immunodeficiency virus status, sex and culture‐intensity at baseline.

Conclusion  Neither zinc nor MMN supplementation had significant effects on culture conversion, but MMN supplementation increased weight gain in TB patients.
Distribution de l'infection à Mycobacterium ulcerans (Ulcère de Buruli) dans la commune de Lalo au Bénin
Authors: Johnson R. C. , Sopoh G. E. , Boko M. , Zinsou C. , Gbovi J. , Makoutode M. , Portaels F.
Published: August 2005

La présente étude, a pour principal objectif d’étudier la distribution de l‘Ulcère de Buruli dans la commune de Lalo, dans le département du Couffo au Bénin. Le recensement des cas d'Ulcère de Buruli hameau par hameau, a permis d'identifier 752 cas dont 160 patients porteurs de lésions évolutives et 592 formes inactives. Ainsi, la prévalence générale (toutes formes confondues) dans la commune de Lalo est de 86.6 pour 10.000 habitants. Cette prévalence peut varier de 0 à 249 cas pour 10.000 habitants d'un arrondissement à un autre de la commune. De même, à l’échelle village, la prèvalence peut varier de 0 à 561 cas pour 10.000 habitants confirmant ainsi le caractère très focalisé dans la distribution de l'Ulcère de Buruli. Les caractéristiques cliniques des formes évolutives recensées, objectivent à l'instar des données de la littérature, une prédominance des cas chez les enfants de moins de 15 ans. Notre étude permet aussi d'objectiver une association entre l’âge et la localisation des lésions. Des études épidémiologiques ultérieures ainsi que des études de l'environnement sont nécessaires en vue d’étudier d‘une part les facteurs de risques qui font que deux villages proches peuvent avoir des niveaux d'endémicité aussi différents, et d'autre part si ces variations géographiques s'accompagnent d'une variation temporelle d'une saison à une autre et d'une année à une autre.