bluuebunny/crossref_metadata_2025 huggingface dataset:
An overview of the Scottish multidisciplinary child protection review
Authors: Daniel Brigid
Published: July 2004

Following the murder of a young child by her stepfather a ministerial review of child protection across Scotland was established. It was carried out by a multidisciplinary team of representatives from education, health‐nursing, health‐medical, police, social work and the Reporter to the Children's Hearing. The review comprised a number of subprojects and included a direct audit of the practice of all the key agencies. The views of the general public, parents, children and professionals were obtained via a set of consultation subprojects. The audit of practice was built around a set of individual, in‐depth case studies. The cases were drawn from the spectrum of child care and protection cases by sampling from cases known to health visitors, education departments, the police and social work departments. The audit considered compliance with guidance, but the key focus was on outcomes for children.

The findings indicated that although there were many examples of good practice with children, a significant number of children were left unprotected or their needs were not met. The issues were not unique to Scotland and are discussed under four key areas. The paper sets out the extent of chronic need amongst the child population that the audit revealed, looks at the messages from consultation about issues of accessing help for children or by children directly, and describes some shortcomings of the current system. Finally the paper analyses the ways that the different agencies interact and sets out a model for how the system can provide a protective network for children who are in need of protection and support.
Who Takes Care of Education 18 months on? A follow‐up study of looked after children's perceptions of support for educational progress
Authors: Harker Rachael M. , Dobel‐Ober David , Akhurst Sofie , Berridge David , Sinclair Ruth
Published: July 2004

This paper represents a follow‐up publication to the findings of a previous paper by documenting the views of a follow‐up sample of 56 young people, aged 12–19 years, looked after in three English local authorities. Young people were interviewed on two separate occasions, 18 months apart, to assess their perceptions of educational progress and identify factors that might support or hinder their education. The interviews took place as part of an ongoing evaluation of the Taking Care of Education project, a development programme designed to facilitate improvements in the education of looked after children. Most young people were aware of individual project‐related activities and a number of these were seen to contribute towards educational progress. Perceptions of educational progress were significantly higher at follow‐up interview and an increased proportion of young people reported that being looked after had had a positive impact upon their education. Carers and teachers continued to be the most frequently mentioned providers of educational support, but the proportion of comments relating to educational support from social workers increased at follow‐up. The most consistent explanation given for improved educational progress was the availability of support and encouragement for educational progress and acknowledgement of young people's achievements.
Underpinning knowledge for child care practice: reconsidering child development theory
Authors: Taylor Carolyn
Published: July 2004

Child development theory has come to be regarded as essential underpinning knowledge for social work practice, a view reinforced by the current research‐minded agenda. Practitioners are enjoined to acquire a more in‐depth knowledge of child development but in this paper it is argued that this agenda requires more scrutiny if social workers are going to engage more meaningfully with the child development literature and use it in a critical and reflexive way in their practice. To this end some key messages drawn from critical approaches to developmental psychology, a literature to date largely unrecognized by social work, are examined for their relevance to practice.
Research Review: Teenage pregnancy and parenthood: the role of fathers
Authors: Bunting Lisa , McAuley Colette
Published: July 2004

From the research available in America and Britain it would appear that the men who father children by teenage mothers tend to be a few years older than their teenage partners, although a minority may be significantly older. With regard to the factors associated with fatherhood there are striking similarities to the literature on teenage mothers. Like teenage mothers young fathers tend to be from low socio‐economic backgrounds, experience lower educational attainment and fewer employment opportunities than their childless peers. Similarly they tend to experience greater psychological and emotional difficulties and may have a history of delinquent behaviour.

These young fathers are involved in a variety of relationships with teenage mothers, few of which result in marriage and many of which result in the breakdown of cohabitation or the termination of the relationship. This pattern of increasing relationship breakdown over time is related to decreasing paternal contact with children in both America and Britain. Often conflictual relationships with teenage mothers or maternal grandparents and a lack of financial resources are cited by young fathers as barriers to their continued involvement and contact with their children. However, the mothers are much more likely to cite paternal disinterest as the reason for a lack of paternal involvement and there is some indication that mothers and fathers have different views on the level of practical involvement expected from fathers. While most of quantitative data on the subject provides a rather negative picture of paternal involvement, qualitative research highlights how many young fathers genuinely want to be involved with their children and would have more contact and input if they could.

While much less is known about the support provided to young fathers in comparison with their female counterparts, there is some suggestion that the support and role expectations provided by the paternal grandmother may influence how involved young fathers are. There is also some indication that a sizeable minority of young men may receive no such support from their family and may also be treated with hostility or ignored by the maternal grandparents. Young fathers also report limited or no contact with midwives, health visitors and social workers.
A new magnetic resonance imaging scoring method for assessment of haemophilic arthropathy
Authors: Lundin B. , Pettersson H. , Ljung R.
Published: July 2004

Summary.  In a European multicentre study, 39 ankles in 28 haemophilic boys were investigated by magnetic resonance imaging (MRI). A new MRI score was developed in the format A(e:s:h) for evaluating haemophilic arthropathy. This scheme provides high resolution and allows separation of different pathological components. The factor A is calculated as the sum of scores for subchondral cysts (maximum value 6), irregularity/erosion of subchondral cortex (maximum 4) and chondral destruction (maximum 6); e, s and h, respectively, represent effusion/haemarthrosis, synovial hypertrophy and haemosiderin deposition, and they are separately evaluated on a scale of 0–4. Working independently, two radiologists scored the 39 ankles twice using both this new ‘European’ scoring method and a previously published ‘Denver’ scoring scheme. Final classification was achieved by consensus. The reproducibility of the readings was assessed, and for both scoring methods the results indicated good or moderate intraobserver agreement, and good, moderate or fair interobserver agreement. These findings suggest that MRI can be useful for semiquantitative evaluation of haemophilic arthropathy, providing the examination is performed according to an appropriate protocol, and the images are evaluated by specially trained radiologists.
Assessing health‐related quality‐of‐life in individuals with haemophilia in China
Authors: Wang T. , Zhang L. , Li H. , Zhao H. , Yang R.
Published: July 2004

Summary.  Haemophilia is a group of inherited, congenital diseases present all through the life. Those disorders are associated with a chronic burden of morbidity punctuated by episodes of acute deterioration in health‐related quality‐of‐life (HR‐QL). The significances of assessing HR‐QL in individuals with haemophilia as an important component of the clinical database have gained increasing recognition in recent years. To the best of our knowledge, reports on the HR‐QL of Chinese patients with haemophilia are not available. The purpose of this paper was to assess the HR‐QL of patients with haemophilia in China. In order to do this, 179 patients with haemophilia (age 16–70) were mailed China quality‐of‐life questionnaire, which was designed specially for this study taking into account the culture characters of Chinese. Compared with the normal male general population, individuals with haemophilia experienced significantly lower levels of HR‐QL and within the subgroups of patients, there was a gradation of HR‐QL from mild < moderate < severe haemophilia patients. Age, clinical severity, degree of arthropathy, hepatitis status, salary and mean annual expenditure for replacement therapy were predictors of HR‐QL. Clinical severity of the disease manifestation rather than the severity of the disease based on molecular classification was a factor that negatively influenced the HR‐QL of patients with haemophilia. Arthropathies of patients with haemophilia in China were more severe than that in western countries because of the poorer medical care and were associated with their lower income and therapy cost. A large number of patients never had hepatitis or HIV serological examination. The exact prevalence of hepatitis and HIV was difficult to obtain and the HR‐QL of hepatitis and HIV positive patients required further study.
The Genetics of bleeding disorders: a report on the UK Haemophilia Centre Doctors’ Organisation annual scientific symposium, 10th October 2003
Authors: Nicolle A. L. , Talks K. L. , Hanley J.
Published: July 2004

The UK Haemophilia Centre Doctors’ Organisation (UKHCDO) held its annual scientific symposium in October 2003, at the International Centre for Life, Newcastle‐upon‐Tyne. The educational day covered a range of topics relating to the genetics of bleeding disorders, including advances in genetics and gene therapy, antenatal diagnosis and counselling. We present the proceedings from the educational day.
Periapical status and quality of root fillings and coronal restorations in an adult Spanish population
Authors: Segura‐Egea J. J. , Jiménez‐Pinzón A. , Poyato‐Ferrera M. , Velasco‐Ortega E. , Ríos‐Santos J. V.
Published: July 2004

Aim  To investigate the quality of root fillings and coronal restorations and their association with periapical status in an adult Spanish population.

Methodology  A total of 180 subjects, aged 37.1 ± 15.7 years, who presented as new patients at the Faculty of Dentistry, Seville, Spain, were examined. All participants underwent a full‐mouth radiographic survey incorporating 14 periapical radiographs. The periapical region of all root filled teeth, excluding third molars, were examined. The technical quality of root fillings was evaluated in terms of length in relation to the root apex and lateral adaptation to the canal wall. Radiographic signs of overhang or open margins associated with coronal restorations were also evaluated. Periapical status was assessed using the Periapical Index score. Statistical analyses were conducted using the Cohen's κ test and logistic regression.

Results  The total number of root filled teeth was 93, and 60 (64.5%) had apical periodontitis (AP). Presence of AP in root filled teeth was associated with inadequate adaptation of the filling (OR = 2.29; P = 0.06), inadequate length of the root filling (OR = 2.44; P = 0.048), and with poor radiographic quality of the coronal restoration (OR = 2.38; P = 0.054). Only 34.4% of the root fillings were adequate from a technical perspective. When both root fillings and coronal restorations were adequate the incidence of AP decreased to 31.3% (OR = 5.50; P < 0.01).

Conclusions  The incidence of AP in root filled teeth was high. Many root fillings were technically unsatisfactory. Adequate root fillings and coronal restorations were associated with a lower incidence of AP; an adequate root filling had a more substantial impact on the outcome of treatment than the quality of the coronal restoration.
Cultivable microbial flora associated with persistent periapical disease and coronal leakage after root canal treatment: a preliminary study
Authors: Adib V. , Spratt D. , Ng Y.‐L. , Gulabivala K.
Published: July 2004

Aim  To identify the cultivable bacterial flora in root filled teeth with persistent periapical lesions and to locate their distribution within the root canal system using an in vitro sampling protocol.

Methodology  Eight freshly extracted root filled teeth were collected from the Oral and Maxillo‐facial Surgery Department, Eastman Dental Hospital. Seven teeth were associated with persistent apical periodontitis and also showed evidence of coronal leakage. Teeth were transferred to an anaerobic chamber immediately after careful extraction and sectioned transversely to give a crown (in all but one case) and two root segments (coronal and apical). Two samples were obtained from each segment, one from dentine and the other from the restoration or gutta‐percha (GP) root filling (46 sites in total). The samples were dispersed, serially diluted and cultured on blood agar and fastidious anaerobic agar (with 5% defibrinated horse blood). The primary growth was subcultured to obtain pure isolates, which were identified by routine microbiological techniques and commercial enzyme tests.

Results  A total of 252 strains were isolated from all the teeth. Of all the isolates, the most prevalent bacteria were Gram‐positive facultative anaerobes 189/252 (75%) with staphylococci (48/252, 19%), streptococci (44/252, 17%), enterococci (20/252, 8%) and Actinomyces species (20/252, 8%) being found in most of the teeth (6/8, 6/8, 5/8, 5/8 and 7/8, respectively). Of the obligate anaerobes (17%), peptostreptococci (7%) were also present in most teeth (7/8). A statistical association between bacterial flora and site (crown/coronal/apical) or surface (dental/GP/restoration) could not be shown.

Conclusions  The predominant group of bacteria in root filled teeth with persistent apical periodontitis and coronal leakage was Gram‐positive facultative anaerobes of which staphylococci followed by streptococci and enterococci were the most prevalent.
The parasitic ciliate Ichthyophthirius multifiliis induces expression of immune relevant genes in rainbow trout, Oncorhynchus mykiss (Walbaum)
Authors: Sigh J , Lindenstrøm T , Buchmann K
Published: July 2004

During an infection with the parasitic ciliate Ichthyophthirius multifiliis, expression of genes encoding complement factor C3, inducible nitric oxide synthase (iNOS), immunoglobulin (IgM) and major histocompatibility complex (MHC‐II) was examined in the skin, head kidney and spleen of rainbow trout using semi‐quantitative reverse transcriptase‐polymerase chain reaction. Induction of C3 transcription levels was evident in the skin and spleen showing extra‐hepatic production of C3. MHC‐II and IgM levels were increased in both head kidney and skin suggesting a production of antibodies at the site of infection, as well as in the lymphoid organs. iNOS expression was only increased briefly in the skin during the infection. These data suggest that complement is involved in immune reactions against I. multifiliis and that mucosal antibodies might be produced at the site of infection.
Occult hepatitis B viral DNA in liver carcinomas from a region with a low prevalence of chronic hepatitis B infection
Authors: Kannangai R. , Molmenti E. , Arrazola L. , Klein A. , Choti M. , Thomas D. L. , Torbenson M.
Published: July 2004

Summary.  Occult hepatitis B is defined by the presence of hepatitis B viral (HBV) DNA in the serum or liver in persons lacking hepatitis B surface antigen (HBsAg) in the serum. A high prevalence of occult HBV has been reported in hepatocellular carcinoma (HCC) from Asia, but little information is available on the prevalence of occult HBV in HCC from regions with a low prevalence of typical chronic hepatitis B infection. In a retrospective study, 19 cases of primary liver cancer were investigated for the presence of occult HBV DNA by amplification of the surface, core, and X gene. In addition, HBV copy numbers were quantitated by real time polymerase chain reaction, genotyped, and samples tested for covalently closed circular HBV DNA, which is a marker of active viral replication. Occult HBV was found in three of 19 cases (16%). Genotyping was successful in two cases, both of which were genotype A. HBV DNA copy numbers were low, all less than 10 copies/μg liver DNA. No closed circular HBV DNA was detected. Thus, in this study occult HBV was of genotype A and was found in a low percentage of cases of HCC and was associated with low tissue HBV DNA copy numbers and no detectable evidence for viral replication.
Comparison of long‐term effects of lymphoblastoid interferon alpha and recombinant interferon alpha‐2a therapy in patients with chronic hepatitis B
Authors: Lin S.‐M. , Tai D.‐I. , Chien R.‐N. , Sheen I.‐S. , Chu C.‐M. , Liaw Y.‐F.
Published: July 2004

Summary. To compare the long‐term effect of natural lymphoblastoid interferon‐alpha (IFN‐αnl) and recombinant IFN‐α2a therapy in patients with chronic hepatitis B, 210 patients in two trials were followed‐up for 1.1–15.5 years following the end of therapy. They included 34 patients who received placebo (control), 67 treated with IFN‐αnl (36 after prednisolone priming) and 109 treated with IFN‐α2a (56 after prednisolone priming). The cumulative sustained response was higher in patients who had been treated with IFN‐αnl after prednisolone priming than was exhibited using IFN‐αnl alone, IFN‐α2a alone or the placebo (P < 0.05), or IFN‐α2a following prednisolone priming (P = 0.052) at the end of 11 years. Hepatocellular carcinoma (HCC) was detected in 1.5% of the IFN‐αnl group, 3.7% of the IFN‐α2a group and 14.7% of the control group (controlvsIFN‐αnl or IFN‐α2a,P < 0.05). The cumulative HCC development was higher in the control group than in the IFN‐αnl group (P < 0.002) and the IFN‐α2a group (P = 0.06). The cumulative survival rate was lower in the control group than in the IFN‐αnl group (P < 0.01) and the IFN‐α2a group (P = 0.02). Multivariate analysis revealed that IFN‐αnl therapy and female gender are significant predictors of sustained response; preexisting cirrhosis, age at entry and IFN therapy are significant factors in both HCC development and survival. In conclusion, IFN‐αnl treatment may have a better long‐term effect on hepatitis B virus (HBV) clearance than IFN‐α2a and placebo, and IFN therapy may provide better long‐term beneficial effects than placebo in terms of HBV clearance, reduction of HCC and prolonged survival.
Longitudinal mapping of protective CD4+ T cell responses against HCV: analysis of fluctuating dominant and subdominant HLA‐DR11 restricted epitopes
Authors: Harcourt G. C. , Lucas M. , Sheridan I. , Barnes E. , Phillips R. , Klenerman P.
Published: July 2004

Summary.  Cellular immunity plays an important role in the control of persistent virus infections such as hepatitis C virus (HCV). Antiviral CD4+ T cell responses have been shown to accompany resolution of acute disease and there is also a consistent association between HLA Class II genes, notably HLADRB1*1101 (and the closely linked HLADQB1*0301) and disease resolution. We initially mapped longitudinal CD4+ T cell responses in an individual after spontaneous resolution of acute HCV, and identified three HLA‐DR11‐restricted responses which vary in immunodominance over time. Functional assays and HLA Class II tetramer staining revealed one to be a response to a commonly recognized epitope, NS31248‐‐1261, although cytokine capture assays showed these specific cells to be at a very low frequency. In this patient, and in others reported, this most frequently recognized HLA‐DR11 restricted epitope is not immunodominant. We analysed whether sequence variability within and between genotypes might account for differences in recognition of HLA‐DR11 restricted epitopes. We found that a limited number, including NS31248‐‐1261, showed extreme sequence conservation. Within NS3, the ability of peptides to accept amino acid substitutions was clearly related to the structure of the protein. Overall the data provide a deeper understanding of the relationship between protein structure and variability of HLA‐DR11 restricted peptides and may explain the apparent dominance of responses to NS31248‐‐1261 across studies but not within an individual immune response.
Reconstructing and predicting the hepatitis C virus epidemic in Greece: increasing trends of cirrhosis and hepatocellular carcinoma despite the decline in incidence of HCV infection
Authors: Sypsa V. , Touloumi G. , Tassopoulos N. C. , Ketikoglou I. , Vafiadis I. , Hatzis G. , Tsantoulas D. , Akriviadis E. , Delladetsima J. , Demonakou M. , Hatzakis A.
Published: July 2004

Summary.  In this study, a comprehensive methodology for modelling the hepatitis C virus (HCV) epidemic is proposed to predict the future disease burden and assess whether the recent decline in the incidence of HCV may affect the future occurrence of cirrhosis and hepatocellular carcinoma (HCC) cases. Using the prevalence of HCV, the distribution of chronic hepatitis C (CHC) patients within the various transmission groups and their infection‐onset times, it was possible to reconstruct the incident infections per year in the past that progressed to CHC in Greece. The natural history of the disease was simulated in subcohorts of newly infected subjects using transition probabilities derived either empirically between fibrosis stages 0–4 or from literature review. Annual estimates of the incidence and prevalence of CHC by fibrosis stage, HCC and mortality in Greece were obtained up to 2030. HCV incidence peaked in the late 1980s at five new infections/10 000 person‐years. Under the assumption of 20–100% decline in HCV incidence after 1990, the cumulative number of incident cirrhosis and HCC cases from 2002–2030 was projected to be lower by 9.6–48.2% and 5.9–29.5%, respectively, than that estimated under the assumption of no decline. However, the prevalent cirrhotic/HCC cases and HCV‐related deaths are predicted to decline in the next 30 years only under the assumption of complete elimination of new HCV infections after 1990. Despite the progress in the reduction of HCV transmission, primary prevention does not seem adequate to reverse the rise in the incidence of cirrhosis and HCC.
A multicentre study of the usefulness of liver biopsy in hepatitis C
Authors: Bain V. G. , Bonacini M. , Govindarajan S. , Ma M. , Sherman M. , Gibas A. , Cotler S. J. , Deschenes M. , Kaita K. , Jhangri G. S.
Published: July 2004

Summary.  The role of liver biopsy in the assessment of chronic hepatitis C is generally accepted yet there is no prospective data available to quantify its contribution. A previous single centre pilot study suggested that the clinician could predict the amount of fibrosis and to a lesser extent, inflammation with moderate accuracy. The 2002 National Institute of Health Hepatitis C Consensus Conference recommended further study of the role of liver biopsy. Our objective was to compare a prediction of biopsy findings by expert clinicians using usually available clinical and laboratory data to actual biopsy results in order to determine whether biopsy is required routinely. This was a prospective observational study conducted at seven university centres in which the accuracy of clinician's predictions of the degree of inflammation and fibrosis were compared with the actual liver biopsy using an adaptation of a standard histological scoring system. We studied 81 adults with previously untreated chronic hepatitis C, raised serum transaminases and positive HCV‐RNA in serum. Clinicians predicted the inflammatory grade in 44 of 80 cases (55%) and the fibrosis stage in 46 of 81 cases (57%). Nine of 17 cirrhotic cases were predicted (sensitivity 53%, specificity 56%). No unexpected additional diagnoses were made on the biopsies. Thus despite knowledge of the clinical and laboratory investigations of patients with hepatitis C, clinicians are unable to accurately predict the hepatic inflammatory grade and fibrotic stage. Liver biopsy is an essential investigation to accurately evaluate the grade and stage of liver disease patients with hepatitis C.
Chronic hepatitis C and no response to antiviral therapy: potential current and future therapeutic options
Authors: Papatheodoridis G. V. , Cholongitas E.
Published: July 2004

Summary.  A significant proportion of chronic hepatitis C patients fails to achieve sustained virologic response even after treatment with the current, more potent, combination of pegylated interferon‐alpha (IFNa) plus ribavirin. Such patients represent a rather heterogeneous group and may be divided initially into relapsers and nonresponders. Both the type of previous therapy and of previous response are very important factors for the indication and the type of re‐treatment. The combination of pegylated IFNa and ribavirin seems to be a rational approach for patients who failed to respond to IFNa monotherapy. Pegylated IFNa‐based regimens appear to induce sustained responses in 40–68% of relapsers but in only 11% of nonresponders to previous therapy with standard IFNa plus ribavirin. Thus, new therapeutic approaches are needed for the latter subgroup of patients as well as those who fail to respond to pegylated IFNa‐based regimens. Such new approaches currently under evaluation include the triple combination of pegylated IFNa, ribavirin, and amantadine, alternative types of IFN, use of agents with ribavirin like activity but lesser degrees of side‐effects, inhibitors of hepatitis C virus (HCV) replication, mainly inhibitors of NS3 protease or helicase, antisense oligonucleotides, and ribozymes, and several immunomodulators. Moreover, maintenance antifibrotic therapy, mostly with low doses of pegylated IFNa, are under evaluation in patients with advanced fibrosis. Thus, even in the current era of the potent pegylated IFNa‐based regimens, the management of these difficult‐to‐treat patients represents an increasingly frequent problem and perhaps the most challenging therapeutic task in chronic hepatitis C.
Monitoring intrahepatic CD8+ T cells by fine‐needle aspiration cytology in chronic hepatitis C infection
Authors: Vrolijk J. M. , Tang T. J. , Kwekkeboom J. , Haagmans B. L. , Herscheid A. J. , Kusters J. G. , Janssen H. L. A. , Brouwer J. T. , Schalm S. W.
Published: July 2004

Summary.  Infection of the liver with hepatitis C virus (HCV) causes compartmentalization of CD8+ cytotoxic T cells to the site of disease. These cells are thought to be involved in viral clearance during interferon therapy. The repetitive analysis of the intrahepatic immune response is hampered by the difficulty to obtain the intrahepatic T cells. The fine‐needle aspiration biopsy (FNAB) technique was evaluated for its use to obtain liver‐derived CD8+ T cells in a minimally invasive way. In 26 chronic HCV patients who were evaluated for Peg‐interferon and ribavirin combination therapy, pre‐treatment FNABs and peripheral blood specimens were obtained simultaneously with liver tissue biopsies, and CD3+ and CD8+ T cells were quantified by immunocytochemistry. The CD8+/CD3+ ratio was significantly higher in the FNABs than in peripheral blood (P < 0.01), and similar to those in portal areas in the tissue biopsies. A significant correlation was observed between numbers of CD3+CD8+ T lymphocytes in the FNABs and the numbers of CD8+ cells in the lobular fields or in the portal tracts of the liver tissue biopsies, but not with CD3+CD8+ T lymphocytes in peripheral blood. Finally, the ratio of CD8+/CD3+ T lymphocytes in FNABs was significantly higher in those patients who responded rapidly to therapy when compared with slow responders at 4 weeks of treatment (P = 0.02). These findings demonstrate that the intrahepatic T‐cell composition is reflected in FNABs, and that the FNAB technique can be used for predicting early virological response to therapy of patients chronically infected with HCV.
Activation of fibronectin gene expression by hepatitis B virus x antigen
Authors: Norton P. A. , Reis H. M. G. P. V. , Prince S. , Larkin J. , Pan J. , Liu J. , Gong Q. , Zhu M. , Feitelson M. A.
Published: July 2004

Summary.  The development of fibrosis and cirrhosis during chronic hepatitis B virus (HBV) infection correlates with the persistent expression of HBV x antigen (HBxAg), which acts in part, by stimulating selected signal transduction pathways, including nuclear factor κB (NF‐κB). To identify NF‐κB responsive genes that are differentially expressed in HBxAg‐positive cells, HepG2 cells were stably transfected with HBxAg, and then with pZeoSV2 or pZeoSV2‐IκBα. When RNAs from each culture were compared by PCR‐select cDNA subtraction, fibronectin (FN) mRNA was shown to be strongly down‐regulated by IκBα. Up‐regulated expression of FN and co‐expression between FN and HBxAg were observed in liver sections from HBV carriers that were stained for HBxAg and analysed for FN mRNA by in situ hybridization (ISH). In liver cell cultures, HBxAg increased the levels of FN mRNA and protein. This was because of the HBxAg‐mediated trans‐activation of the FN promoter, which was NF‐κB‐dependent. HBxAg also antagonized the repression of the FN promoter by the tumour suppressor, p53. Hence, the FN gene may be a natural target for HBxAg trans‐activation, perhaps through activation of NF‐κB and inactivation of p53, thereby contributing to the accumulation of FN in the liver over the course of chronic HBV infection.
RNA interference in Histoplasma capsulatum demonstrates a role for α‐(1,3)‐glucan in virulence
Authors: Rappleye Chad A. , Engle Jacquelyn T. , Goldman William E.
Published: July 2004

Histoplasma capsulatum is a fungal pathogen that causes respiratory and systemic disease by proliferating within macrophages. While much is known about histoplasmosis, only a single virulence factor has been defined, in part because of the inefficiency of Histoplasma reverse genetics. As an alternative to allelic replacement, we have developed a telomeric plasmid‐based system for silencing gene expression in Histoplasma by RNA interference (RNAi). Episomal expression of long RNAs that form stem–loop structures triggered gene silencing. To test the effectiveness of RNAi in Histoplasma, we depleted expression of a gfp transgene as well as two endogenous genes, ADE2 and URA5, and showed significant reductions in corresponding gene function. Silencing was target gene specific, stable during macrophage infection and reversible. We used RNAi targeting AGS1 (encoding α‐(1,3)‐glucan synthase) to deplete levels of α‐(1,3)‐glucan, a cell wall polysaccharide. Loss of α‐(1,3)‐glucan by RNAi yielded phenotypes indistinguishable from an AGS1 deletion: attenuation of the ability to kill macrophages and colonize murine lungs. This demonstrates for the first time that α‐(1,3)‐glucan is an important contributor to Histoplasma virulence.
A structural step into the SRP cycle
Authors: Wild Klemens , Rosendal Ken R. , Sinning Irmgard
Published: July 2004

Co‐translational targeting of secretory and membrane proteins to the translocation machinery is mediated by the signal recognition particle (SRP) and its membrane‐bound receptor (SR) in all three domains of life. Although the overall composition of the SRP system differs, the central ribonucleoprotein core and the general mechanism of GTP‐dependent targeting are highly conserved. Recently, structural studies have contributed significantly to our understanding of the molecular organization of SRP. SRP appears as a structurally flexible particle modulated and regulated by its interactions with the ribosome–nascent chain complex, the translocon and the SR. The SRP core (SRP54 with its cognate RNA binding site) plays a central role in these interactions and communicates the different binding states by long‐range interdomain communication. Based on recent structures of SRP54, a model for signal peptide binding stimulating the GTP affinity during the first step of the SRP cycle is presented. The model is placed in the context of the recent structures of mammalian SRP bound to a ribosome–nascent chain complex and of a subcomplex of SRP–SR.
Translation termination factors function outside of translation: yeast eRF1 interacts with myosin light chain, Mlc1p, to effect cytokinesis
Authors: Valouev I. A. , Urakov V. N. , Kochneva‐Pervukhova N. V. , Smirnov V. N. , Ter‐Avanesyan M. D.
Published: July 2004

The translation termination factor eRF1 recognizes stop codons at the A site of the ribosome and induces peptidyl‐tRNA hydrolysis at the peptidyl transferase centre. Recent data show that, besides translation, yeast eRF1 is also involved in cell cycle regulation. To clarify the mechanisms of non‐translational functions of eRF1, we performed a genetic screen for its novel partner proteins. This screen revealed the gene for myosin light chain, Mlc1p, acting as a dosage suppressor of a temperature‐sensitive mutation in the SUP45 gene encoding eRF1. eRF1 and Mlc1p are able to interact with each other and, similarly to depletion of Mlc1p, mutations in the SUP45 gene may affect cytokinesis. Immunofluorescent staining performed to determine localization of Mlc1p has shown that the sup45 mutation, which arrests cytokinesis, redistributed Mlc1p, causing its disappearance from the bud tip and the bud neck. The data obtained demonstrate that yeast eRF1 has an important non‐translational function effecting cytokinesis via interaction with Mlc1p.
Regulators of G‐protein signalling in Aspergillus nidulans: RgsA downregulates stress response and stimulates asexual sporulation through attenuation of GanB (Gα) signalling
Authors: Han Kap‐Hoon , Seo Jeong‐Ah , Yu Jae‐Hyuk
Published: July 2004

Regulators of G‐protein signalling play a crucial role in controlling the degree of heterotrimeric G‐protein signalling. In addition to the previously studied flbA, we have identified three genes (rgsA, rgsB and rgsC) encoding putative RGS proteins in the genome of Aspergillus nidulans. Characterization of the rgsA gene revealed that RgsA downregulates pigment production and conidial germination, but stimulates asexual sporulation (conidiation). Deletion of rgsA (ΔrgsA) resulted in reduced colony size with increased aerial hyphae, elevated accumulation of brown pigments as well as enhanced tolerance of conidia and vegetative hyphae against oxidative and thermal stress. Moreover, ΔrgsA resulted in conidial germination in the absence of a carbon source. Deletion of both flbA and rgsA resulted in an additive phenotype, suggesting that the G‐protein pathways controlled by FlbA and RgsA are different. Morphological and metabolic alterations caused by ΔrgsA were suppressed by deletion of ganB encoding a Gα subunit, indicating that the primary role of RgsA is to control negatively GanB‐mediated signalling. Overexpression of rgsA caused inappropriate conidiation in liquid submerged culture, supporting the idea that GanB signalling represses conidiation. Our findings define a second and specific RGS–Gα pair in A. nidulans, which may govern upstream regulation of fungal cellular responses to environmental changes.
FlaC, a protein of Campylobacter jejuni TGH9011 (ATCC43431) secreted through the flagellar apparatus, binds epithelial cells and influences cell invasion
Authors: Song Y. C. , Jin S. , Louie H. , Ng D. , Lau R. , Zhang Y. , Weerasekera R. , Al Rashid S. , Ward L. A. , Der S. D. , Chan V. L.
Published: July 2004

Type III secretion systems identified in bacterial pathogens of animals and plants transpose effectors and toxins directly into the cytosol of host cells or into the extracellular milieu. Proteins of the type III secretion apparatus are conserved among diverse and distantly related bacteria. Many type III apparatus proteins have homologues in the flagellar export apparatus, supporting the notion that type III secretion systems evolved from the flagellar export apparatus. No type III secretion apparatus genes have been found in the complete genomic sequence of Campylobacter jejuni NCTC11168. In this study, we report the characterization of a protein designated FlaC of C. jejuni TGH9011. FlaC is homologous to the N‐ and C‐terminus of the C. jejuni flagellin proteins, FlaA and FlaB, but lacks the central portion of these proteins. flaC null mutants form a morphologically normal flagellum and are highly motile. In wild‐type C. jejuni cultures, FlaC is found predominantly in the extracellular milieu as a secreted protein. Null mutants of the flagellar basal rod gene (flgF) and hook gene (flgE) do not secrete FlaC, suggesting that a functional flagellar export apparatus is required for FlaC secretion. During C. jejuni infection in vitro, secreted FlaC and purified recombinant FlaC bind to HEp‐2 cells. Invasion of HEp‐2 cells by flaC null mutants was reduced to a level of 14% compared with wild type, suggesting that FlaC plays an important role in cell invasion.
Mycobacterial lipoarabinomannan and related lipoglycans: from biogenesis to modulation of the immune response
Authors: Briken Volker , Porcelli Steven A. , Besra Gurdyal S. , Kremer Laurent
Published: July 2004

The cell wall component lipoarabinomannan (ManLAM) from Mycobacterium tuberculosis is involved in the inhibition of phagosome maturation, apoptosis and interferon (IFN)‐γ signalling in macrophages and interleukin (IL)‐12 cytokine secretion of dendritic cells (DC). All these processes are important for the host to mount an efficient immune response. Conversely, LAM isolated from non‐pathogenic mycobacteria (PILAM) have the opposite effect, by inducing a potent proinflammatory response in macrophages and DCs. LAMs from diverse mycobacterial species differ in the modification of their terminal arabinose residues. The strong proinflammatory response induced by PILAM correlates with the presence of phospho‐myo‐inositol on the terminal arabinose. Interestingly, recent work indicates that the biosynthetic precursor of LAM, lipomannan (LM), which is also present in the cell wall, displays strong proinflammatory effects, independently of which mycobacterial species it is isolated from. Results from in vitro assays and knock‐out mice suggest that LM, like PILAM, mediates its biological activity via Toll‐like receptor 2. We hypothesize that the LAM/LM ratio might be a crucial factor in determining the virulence of a mycobacterial species and the outcome of the infection. Recent progress in the identification of genes involved in the biosynthesis of LAM is discussed, in particular with respect to the fact that enzymes controlling the LAM/LM balance might represent targets for new antitubercular drugs. In addition, inactivation of these genes may lead to attenuated strains of M. tuberculosis for the development of new vaccine candidates.
Natural variation and QTL analysis for cationic mineral content in seeds of Arabidopsis thaliana
Authors: VREUGDENHIL D. , AARTS M. G. M. , KOORNNEEF M. , NELISSEN H. , ERNST W. H. O.
Published: July 2004

Naturally occurring genetic variation for contents of cationic minerals in seeds of Arabidopsis thaliana was studied by screening a series of accessions (ecotypes) for Ca, Fe, K, Mg, Mn, Na, Zn, and for total contents of P. Variation was observed for all minerals and correlations between contents of various minerals were present, most noticeably between Ca and Mg, P and Mg, and P and Mn. The genetic basis of this variation was further studied by QTL analysis, using the Landsberg erecta (Ler) × Cape Verde Islands (Cvi) recombinant inbred population. For all minerals, except Na, one or more QTL were detected, explaining up to 78% of the variation. The map positions of several QTL were confirmed by analysis of near isogenic lines, carrying small Cvi introgressions in Ler background. Interesting co‐locations of QTL suggest pleiotropic effects, due to physiological coupling of the accumulation of certain minerals or to linkage of different genes. By comparing the map positions of QTL with the positions of genes expected to play a role in cation translocation, several candidate genes are suggested.
Effect of respiratory homeostasis on plant growth in cultivars of wheat and rice
Authors: KURIMOTO K. , DAY D. A. , LAMBERS H. , NOGUCHI K.
Published: July 2004

Some plants have the ability to maintain similar respiratory rates (measured at the growth temperature), even when grown at different temperatures, a phenomenon referred to as respiratory homeostasis. The underlying mechanisms and ecological importance of this respiratory homeostasis are not understood. In order to understand this, root respiration and plant growth were investigated in two wheat cultivars (Triticum aestivum L. cv. Stiletto and cv. Patterson) with a high degree of homeostasis, and in one wheat cultivar (T. aestivum L. cv. Brookton) and one rice cultivar (Oryza sativa L. cv. Amaroo) with a low degree of homeostasis. The degree of homeostasis (H) is defined as a quantitative value, which occurs between 0 (no acclimation) and 1 (full acclimation). These plants were grown hydroponically at constant 15 or 25 °C. A good correlation was observed between the rate of root respiration and the relative growth rates (RGR) of whole plant, shoot or root. The plants with high H showed a tendency to maintain their RGR, irrespective of growth temperature, whereas the plants with low H grown at 15 °C showed lower RGR than those grown at 25 °C. Among several parameters of growth analysis, variation in net assimilation rate per shoot mass (NARm) appeared to be responsible for the variation in RGR and rates of root respiration in the four cultivars. The plants with high H maintained their NARm at low growth temperature, but the plants with low H grown at 15 °C showed lower NARm than those grown at 25 °C. It is concluded that respiratory homeostasis in roots would help to maintain growth rate at low temperature due to a smaller decrease in net carbon gain at low temperature. Alternatively, growth rate per se may control the demand of respiratory ATP, root respiration rates and sink demands of photosynthesis. The contribution of nitrogen uptake to total respiratory costs was also estimated, and the effects of a nitrogen leak out of the roots and the efficiency of respiration on those costs are discussed.
The decrease in growth of phosphorus‐deficient maize leaves is related to a lower cell production
Authors: ASSUERO S. G. , MOLLIER A. , PELLERIN S.
Published: July 2004

The spatial distribution of leaf elongation and adaxial epidermal cell production in leaf 6 of maize (Zea mays L. cv. Cecilia) plants grown in a growth chamber under two contrasting availabilities of P in the soil was investigated. Lower displacement velocities from 32.5 mm from leaf base and a shorter growth zone were found in low P (LP) leaves compared with control leaves. P deficiency significantly diminished maximum relative elemental growth rate and shifted its location closer to the leaf base. Cells were significantly longer in LP than in control leaves for all positions from the leaf base except at the end of the growth zone. For both treatments it took a similar time for a cell situated at the leaf base to reach the limit of the growth zone. The average length of the cell division zone was decreased by 21% in LP leaves. Significant differences were found in cell production and cell division rates from 12.5 mm from the leaf base although maximum values were similar between P treatments. A shorter zone of cell division with lower cell production rates along most of its length was the regulatory event that decreased cell production, and ultimately leaf elongation rates, in P‐deficient maize plants.
Low‐temperature photosynthetic performance of a C4grass and a co‐occurring C3grass native to high latitudes
Authors: KUBIEN D. S. , SAGE R. F.
Published: July 2004

The photosynthetic performance of C4plants is generally inferior to that of C3species at low temperatures, but the reasons for this are unclear. The present study investigated the hypothesis that the capacity of Rubisco, which largely reflects Rubisco content, limits C4photosynthesis at suboptimal temperatures. Photosynthetic gas exchange, chlorophyllafluorescence, and thein vitroactivity of Rubisco between 5 and 35 °C were measured to examine the nature of the low‐temperature photosynthetic performance of the co‐occurring high latitude grasses,Muhlenbergia glomerata(C4) andCalamogrostis canadensis(C3). Plants were grown under cool (14/10 °C) and warm (26/22 °C) temperature regimes to examine whether acclimation to cool temperature alters patterns of photosynthetic limitation. Low‐temperature acclimation reduced photosynthetic rates in both species. The catalytic site concentration of Rubisco was approximately 5.0 and 20 µmol m−2inM. glomerataandC. canadensis, respectively, regardless of growth temperature. In both species,in vivoelectron transport rates below the thermal optimum exceeded what was necessary to support photosynthesis. In warm‐grownC. canadensis, the photosynthesis rate below 15 °C was unaffected by a 90% reduction in O2content, indicating photosynthetic capacity was limited by the capacity of Pi‐regeneration. By contrast, the rate of photosynthesis inC. canadensisplants grown at the cooler temperatures was stimulated 20–30% by O2reduction, indicating the Pi‐regeneration limitation was removed during low‐temperature acclimation. InM. glomerata,in vitroRubisco activity and gross CO2assimilation rate were equivalent below 25 °C, indicating that the capacity of the enzyme is a major rate limiting step during C4photosynthesis at cool temperatures.
Gene expression profiling and protection of Medicago truncatula against a fungal infection in response to an elicitor from green algae Ulva spp
Authors: CLUZET S. , TORREGROSA C. , JACQUET C. , LAFITTE C. , FOURNIER J. , MERCIER L. , SALAMAGNE S. , BRIAND X. , ESQUERRÉ‐TUGAYÉ M.‐T. , DUMAS B.
Published: July 2004

Elicitors are molecules known to trigger plant defence responses against pathogens. In a search for new sources of eliciting compounds from marine algae, an extract was prepared from green algae, Ulva spp., and its elicitor activity was established on the model legume, Medicago truncatula. When infiltrated into plant tissues or sprayed onto the leaves, this extract induced the expression of the defence‐related marker gene PR10 without provoking necrosis. Spraying a solution at 500 µg mL−1 was sufficient to obtain maximum induction of PR10 after 2 d. Using a cDNA array enriched in genes potentially involved in plant defence, the expression of 152 genes was monitored after one or two consecutive treatments. A broad range of defence‐related transcripts was found to be up‐regulated, notably genes involved in the biosynthesis of phytoalexins, pathogenesis‐related proteins and cell wall proteins. In contrast, the expression of primary metabolism‐related genes did not change significantly. Consistent with its effect on defence gene expression, it was found that prior treatment of M. truncatula with the Ulva extract protected the plants against subsequent infection by the pathogenic fungus Colletotrichum trifolii.