Sociodemographic disparities in non-diabetic hyperglycaemia and the transition to type 2 diabetes: evidence from the English Longitudinal Study of Ageing

AIM

To explore whether there are social inequalities in non-diabetic hyperglycaemia (NDH) and in transitions to type 2 diabetes mellitus and NDH low-risk status in England.

METHODS

Some 9143 men and women aged over 50 years were analysed from waves 2, 4, 6 and 8 (2004-2016) of the English Longitudinal Study of Ageing (ELSA). Participants were categorized as: NDH 'low-risk' [HbA_1c < 42 mmol/mol (< 6.0%)], NDH [HbA_1c 42-47 mmol/mol (6.0-6.4%)] and type 2 diabetes [HbA_1c > 47 mmol/mol (> 6.4%)]. Logistic regression models estimated the association between sociodemographic characteristics and NDH, and the transitions from NDH to diagnosed or undiagnosed type 2 diabetes and low-risk status in future waves.

RESULTS

NDH was more prevalent in older participants, those reporting a disability, those living in deprived areas and in more disadvantaged social classes. Older participants with NDH were less likely to progress to undiagnosed type 2 diabetes [odds ratio (OR) 0.27, 95% confidence interval (CI) 0.08, 0.96]. NDH individuals with limiting long-standing illness (OR 1.72, 95% CI 1.16, 2.53), who were economically inactive (OR 1.60, 95% CI 1.02, 2.51) or from disadvantaged social classes (OR 1.63, 95% CI 1.02, 2.61) were more likely to progress to type 2 diabetes. Socially disadvantaged individuals were less likely (OR 0.64, 95% CI 0.41, 0.98) to progress to NDH low-risk status.

CONCLUSIONS

There were socio-economic differences in NDH prevalence, transition to type 2 diabetes and transition to NDH low-risk status. Disparities in transitions included the greater likelihood of disadvantaged social groups with NDH developing type 2 diabetes and greater likelihood of advantaged social groups with NDH becoming low-risk. These socio-economic differences should be taken into account when targeting prevention initiatives.

Facilitating engagement and interaction in teamwork: an online tool

This article was migrated. The article was not marked as recommended. Teamwork is an essential transferable skill that all graduates need to develop, and will contribute positively to student's development as practioners throughout their academic and clinical career. However, ensuring fair and transparent assessment of group work can be challenging when awarding individual marks. To address this we have developed and piloted an on-line facility for groups of dental students. This facility enables the recording of team meetings in real time, allowing easier monitoring of individual contributions and promoting reflective peer review by individuals in the group. Forty four second year dental students attended initial focus group meeting. Feedback on traditional teamwork modes of assessment were negative, with students disappointed that their mark may be lowered by other group members not taking the work seriously, or working at the last minute. The e-portfolio teamwork component was piloted and a second round of focus groups carried out (51 students). The e-portfolio component was engaged with by all students; with the 'up-load' facility and the area for sharing information being cited as useful. In conclusion, the e-portfolio component developed is a useful tool in allowing and encouraging reflection, evaluation and monitoring contribution.

P3-07-42: Lymphovascular Invasion Best Correlates with Presence of Nodal Metastasis in Sentinel Lymph Node Biopsy

Background. Sentinel lymph node biopsy (SLNB) biopsy is routinely practised for axillary staging with 25–30% having positive SLN. Tumour size is the most important parameter taken into consideration in decision making in node negative patients with a size cut off for 4–5cm dependant on different units. Lymphovascular invasion (LVI) and Ki-67 a cell-cycle antigen are known important prognostic markers along with the tumour grade, oestrogen receptor and herceptin receptor status.

Aim. To examine whether lymphovascular invasion, Ki-67 or any other factors can be used as a predictor for axillary lymph node involvement and hence prognosis.

METHODS. A prospective study of 264 patients with invasive breast cancer undergoing SLN biopsy between January 2009 and December 2010.

Histopathology reports were reviewed regarding LVI, Ki-67, grade, oestrogen, Progesterone and Herceptin receptor and SLN status. Stats direct was used to analyse data. Logistic regression was used and p-value calculated.

RESULTS. LVI (p value=0.0001) and size(p value=0.0273) were the two most significant factors associated with node positivity. Grade of tumour had a p-value of 0.0825 and Ki67 had a p-value of 0.5217 which were not significant.

Introduction of an e-portfolio in clinical dentistry: staff and student views

INTRODUCTION

An electronic portfolio was introduced for undergraduate students in the School of Dental Sciences at Newcastle University. Its introduction was evaluated in terms of both staff and student response.

METHODS

A quantitative-qualitative methodology was adopted. Student views were examined quantitatively using a Likert scale based questionnaire both pre- and post-introduction of the eportfolio. Staff views were examined qualitatively by the use of focus groups.

RESULTS AND DISCUSSION

Findings included that the system was easy to use and it provided a large quantity of high quality data. The aim of the system to improve reflection and feedback was not perceived as a benefit by staff or students. The need for training was highlighted and a major disadvantage of the system was its time consuming nature. The evaluation has lead to further development of the system and continued evaluation will be important.

Scarlet fever outbreak in two nurseries in southwest England

Fifty cases of scarlet fever were reported in a county in southwest England between 1 January and 28 February 2006

The epidemiology of assault across the West Midlands

OBJECTIVES

The purpose of this study is to look at accident and emergency (A&E) attendances and admissions after assault in the West Midlands NHS region across a wide range of acute units.

METHODS

This study used data from two sources, the A&E Minimum Data Set and the Hospital Episode Statistics database. Analyses were based on data from 12 of the 21 acute trusts in the West Midlands NHS region for the period 1 April 1999 to 31 March 2000.

RESULTS

Analyses were performed on 15 969 A&E attendances and 1596 admissions. Some 67.4% of attenders and 84.2% of those admitted were male. The mean age of the patients was between 27 and 29 years. Attendance peaked between 2100 and 0259, especially on Friday and Saturday night. The most common injury was to the head. Some 75.3% of A&E attenders were discharged home. The average stay in hospital was two days and six deaths were recorded. Those living in the most deprived areas were nearly four times more likely to be admitted than those in the least deprived areas (175.9 per 1000 compared with 45.1 per 1000).

CONCLUSIONS

This study shows assault is predominately a male phenomenon, worst in the evenings and at weekends, and is positively related to deprivation. It is probable that the levels recorded will be an underestimate, however with some additions to the information collected hospital records could create the basis for a comprehensive surveillance system.

Breakpoint position on 17q identifies the most aggressive neuroblastoma tumors

Gain of chromosome arm 17q is a powerful prognostic factor in neuroblastoma, and the distribution of 17q breakpoints suggests that the dosage of one or more genes in 17q22-23 to 17qter is critical for tumor progression. To identify the smallest region of 17q gain, we used eight probes to map translocation breakpoints in 48 primary neuroblastoma tumors. We identified at least five different breakpoints, all localized within the proximal part of 17q (from D17Z1 to MPO). The shortest region of gain identified by these probes extends from MPO (17q23.1) to 17qter. Surprisingly, we found that breakpoints localized proximal to ERBB2 (17q12) were associated with significantly better patient survival than breakpoints localized distal to ERBB2. Breakpoints localized distal to ERBB2 identified patients with a particularly poor prognosis, higher mitotic karyorrhectic index, and stage 4 disease. This implies that breakpoint position on 17q is a discriminative factor within this prognostically poor group of patients. This result also suggests that the biological effect of 17q gain during neuroblastoma progression has a complex basis. We propose that this involves dosage alterations of genes localized on both sides of the 17q breakpoints, with a gene or genes mapping between 17cen and 17q12 acting to suppress progression, and a gene or genes mapping between 17q23.1 and 17qter acting to promote tumor progression.

Nearest neighbour analysis of MCM protein complexes in Drosophila melanogaster

The MCM proteins are a group of six proteins whose action is vital for DNA replication in eukaryotes. It has been suggested that they constitute the replicative helicase, with a subset of the proteins forming the catalytic helicase (MCM4,6,7) while the others have a loading or control function. In this paper we show that all six MCM proteins are present in equivalent amounts in soluble extracts and on chromatin. We have also analysed soluble and chromatin-associated MCM protein complexes under different conditions. This suggests that all six MCM proteins are always found in a complex with each other, although the interaction between the individual MCM proteins is not equivalent as stringent salt conditions are able to break the intact complex into a number of stable subcomplexes. These data contribute to the ongoing debate about the nature of MCM complexes, supporting the hypothesis that they act as a heterohexamer rather than as a number of different subcomplexes. Finally, using protein-protein cross-linking we have shown that MCM2 interacts directly with MCM5 and MCM6; MCM5 with MCM3 and MCM2; and MCM6 with MCM2 and MCM4. This provides the first direct information about specific subunit contacts in the MCM complex.

Comprehensive genetic and histopathologic study reveals three types of neuroblastoma tumors

PURPOSE

To determine the relationship between multiple genetic features, tumor morphology, and prognosis in neuroblastoma.

PATIENTS AND METHODS

The genetic alterations and morphologic features that underpin three histopathologic risk classifications were analyzed in 108 neuroblastoma patients. Tumors were subdivided into four groups based on the three most frequent and prognostically significant genetic alterations (17q gain, 1p deletion, and MYCN amplification), and all other genetic, morphologic, and clinical data were analyzed with respect to these groups.

RESULTS

Our analyses identify three nonoverlapping tumor types with distinct genetic and morphologic features, defined here as types 1, 2, and 3. Type 1 tumors show none of the three significant genetic alterations and have good prognosis. Both type 2 (17q gain only or 17q gain and 1p del) and type 3 (17q gain, 1p del, and MYCN amplification) tumors progress. However, these tumor types are distinguished clinically by having significantly different median age at diagnosis and median progression-free survival (PFS). Multivariate analysis indicates that 17q gain is the only independent prognostic factor among all genetic, histopathologic, and clinical factors analyzed. Among histopathologic risk systems, the International Neuroblastoma Pathology Classification was the best predictor of PFS.

CONCLUSION

Our results indicate that specific combinations of genetic changes in neuroblastoma tumors contribute to distinct morphologic and clinical features. Furthermore, the identification of two genetically and morphologically distinct types of progressing tumors suggests that possibilities for different therapeutic regimens should be investigated.

The Drosophila Dpit47 protein is a nuclear Hsp90 co-chaperone that interacts with DNA polymerase α

Hsp90 is gaining increasing importance as a protein involved in controlling the normal functioning of the cell. To do this it apparently interacts with a battery of co-chaperone proteins that are involved in both substrate recognition and the progression of the Hsp90 catalytic pathway. In this report we have identified the Drosophila Dpit47 protein (DNA polymerase interacting tpr containing protein of 47 kDa) through its interaction with the DNA polymerase α. This protein is a predominantly nuclear protein, which forms a tight and stoichiometric interaction with Hsp90 and shows interaction with Hsp70. It also has substantial homology to other known Hsp90 co-chaperones, e.g. CNS1 and hop1, making it likely that this protein also functions as an Hsp90 co-chaperone.

The interaction with the DNA polymerase α is not related to the special situation in early embryos where there are large amounts of maternal protein stockpiles of the polymerase, as it occurs to the same level in early and late embryos and also in proliferating cell culture. However, it does not occur in quiescent cells, making it likely that the protein is related to proliferation. This is also consistent with Dpit47 expression being higher in proliferating cells. The interaction between the Dpit47 and the polymerase takes place predominantly in the nucleoplasm, and seems to involve several subunits of the polymerase in comparable amounts, making it unlikely that it is solely required for the assembly of the polymerase complex. The polymerase can also be seen to interact with Hsp90, and the interaction between Dpit47 and the polymerase is increased by the specific Hsp90 inhibitor geldanamycin. This suggests that a complex of the Dpit47, Hsp90 and DNA polymerase exists in the cell. The interaction between DNA polymerase α and Dpit47 completely inhibits the activity of the polymerase.

These results suggest that Hsp90 acts as a chaperone for DNA polymerase α and that this interaction is mediated through the novel co-chaperone Dpit47. This provides the first suggestion of a role for chaperones in DNA replication in higher eukaryotes.

Identification and characterisation of the Drosophila homologue of the yeast Uba2 gene

We have identified the Drosophila uba2 protein (dUba2). Analysis of the amino acid composition reveals similarity with both the mammalian (47% identity) and yeast (31% identity) homologues. dUba2 is present throughout the Drosophila life cycle but is most abundant during stages of proliferation. The protein is nucleoplasmic throughout much of the cell cycle, however it is lost from the nucleus during mitosis. The DUba2 localisation in the nucleoplasm is not uniform but is observed as concentrated patches reminiscent of the staining patterns seen for other proteins from this group. The nature of these sites is not clear, however the failure of dUba2 to localise to the sites of chorion amplification in ovaries suggests that they are not sites of ongoing DNA replication.

Df31 is a novel nuclear protein involved in chromatin structure in Drosophila melanogaster

We originally isolated the Df31 protein from Drosophila embryo extracts as a factor which could decondense Xenopus sperm, by removing the sperm specific proteins and interacting with histones to facilitate their loading onto DNA. We now believe that this protein has a more general function in cellular DNA metabolism. The Df31 gene encodes a very hydrophilic protein with a predicted molecular mass of 18.5 kDa. Immunostaining showed that Df31 was present in a wide range of cell types throughout differentiation and in both dividing and non-dividing cells. In all cases the protein is present in large amounts, comparable with the level of nucleosomes. Injection of antisense oligonucleotides to lower the level of Df31 in embryos caused severe disruption of the nuclear structure. Large irregular clumps of DNA were formed, and in most cases the amount of DNA associated with each clump was more than that found in a normal nucleus. Immunofluorescence, cell fractionation, and formaldehyde cross-linking show that Df31 is associated with chromatin and that a significant fraction of it binds very tightly. It also shows the same binding characteristics when loaded onto chromatin in vitro. Chromatin fractionation shows that Df31 is tightly associated with nucleosomes, preferentially with oligonucleosomes. Despite this no differences were observed in the properties of nucleosomes loaded in the in vitro system in the presence and absence of Df31. These results suggest that Df31 has a role in chromosomal structure, most likely acting as a structural protein at levels of folding higher than that of nucleosomes.

17q gain in neuroblastoma predicts adverse clinical outcome. U.K. Cancer Cytogenetics Group and the U.K. Children's Cancer Study Group

BACKGROUND

It is now recognized that gain of chromosome 17 material is the most frequent genetic abnormality of neuroblastoma cells. Several studies have linked 17q gain with known adverse prognostic factors: patient age >1 year, advanced stage disease, deletion of chromosome arm 1 p, and amplification of the MYCN oncogene. We sought to further investigate the clinical and prognostic associations of chromosome 17 status in relation to other well-established predictive factors.

PROCEDURE

In a collaborative study by UK cytogenetics centres, we compiled a series of 104 neuroblastoma tumours for which the status of chromosome 17 was confidently defined by cytogenetics, metaphase or interphase FISH, or CGH analysis. The results were correlated with data on 1p and MYCN, and with centrally collated clinical and survival information.

RESULTS

Gain of 17q (i.e., unbalanced gain of segment 17q21-qter) was found in 66.3% of tumours, while 33.7% showed a '17q normal' status (i.e., no gain at all, or gain of whole chromosome 17 relative to ploidy). Gain of 17q was strongly associated with advanced stage disease, patient age >1 year, 1p deletion, and MYCN amplification (all P< 0.01). In univariate analysis, 17q gain was a significant predictor of adverse outcome (projected 5 year relapse-free survival 15.6% compared to 75.2% in cases lacking this feature in tumour cells; (P < 0.0001). In multivariate analysis, 17q gain was more strongly associated with adverse outcome than was either stage (Stage 4 vs other combined) or 1p status.

CONCLUSION

We conclude that gain of chromosome segment 17q21-qter is of great biological and clinical importance in neuroblastoma, and that its detection at diagnosis should be a priority.

Localisation of the DmCdc45 DNA replication factor in the mitotic cycle and during chorion gene amplification

The cdc45 protein was originally identified in Saccharomyces cerevisiae and shown to be essential for initiation of eukaryotic DNA replication. Subsequent isolation and characterisation of the corresponding genes from fission yeast, Xenopus and mammals also support a replication role for the protein in these species. They further suggest that during the course of its function cdc45 interacts with a number of other replication proteins, including minichromosome maintenance proteins, the origin recognition complex and DNA polymerase alpha. We have cloned the gene coding for cdc45 protein from Drosophila melanogaster. We have analysed the expression pattern of the cdc45 protein throughout the cell cycle and the life cycle using a combination of indirect immunofluorescence and subcellular fractionation. Our data show that cellular localisation and developmental regulation of the protein is consistent with a role in DNA replication. DmCdc45 is predominantly expressed in proliferating cells. In addition, its subcellular location is nuclear during interphase and the protein shows association with chromatin. The chromatin-associated form of the protein shows a post-translational modification, which may be involved in control of the action of the protein. DmCdc45 shows interactions with mcm proteins, however, the interactions detected show some specificity, perhaps suggesting a preferential association with particular mcm proteins. In addition we show that a stoichiometric mcm interaction may not be obligatory for the function of cdc45 in follicle cell replication, because, unlike the mcm proteins, DmCdc45 localises to the chorion amplification foci in the follicle cells of the ovary.

Importin-alpha3 is required at multiple stages of Drosophila development and has a role in the completion of oogenesis

The Drosophila importin-alpha3 gene was isolated through its interaction with the large subunit of the DNA polymerase alpha in a two-hybrid screen. The predicted protein sequence of Importin-alpha3 is 65-66% identical to those of the human and mouse importin-alpha3 and alpha4 and 42.7% identical to that of Importin-alpha2 (Oho31/Pendulin), the previously reported Drosophila homologue. Both Importin-alpha3 and Importin-alpha2 interact with similar subsets of proteins in vitro, one of which is Ketel, the importin-beta homologue of Drosophila. importin-alpha3 is an essential gene, whose encoded protein is expressed throughout development. During early embryogenesis, Importin-alpha3 accumulates at the nuclear membrane of cleavage nuclei, whereas after blastoderm formation it is characteristically found within the interphase nuclei. Nuclear localisation is seen in several tissues throughout subsequent development. During oogenesis its concentration within the nurse cell nuclei increases during stages 7-10, concomitant with a decline in levels in the oocyte nucleus. Mutation of importin-alpha3 results in lethality throughout pupal development. Surviving females are sterile and show arrest of oogenesis at stages 7-10. Thus, Importin-alpha3-mediated nuclear transport is essential for completion of oogenesis and becomes limiting during pupal development. Since they have different expression patterns and subcellular localisation profiles, we suggest that the two importin-alpha homologues are not redundant in the context of normal Drosophila development.

Phase I trials in pediatric oncology: perceptions of pediatricians from the United Kingdom Children's Cancer Study Group and the Pediatric Oncology Group

PURPOSE

To identify areas of concern regarding the conduct of phase I trials, the perceived expectations and motivations of the parents of children entered, the expectations of toxicity and benefit, and the ethical concerns of pediatric hematologists and oncologists in the United Kingdom and North America.

METHODS

A survey instrument consisting of 19 open- and closed-ended questions was sent to United Kingdom Children's Cancer Study Group (UKCCSG)- and Pediatric Oncology Group (POG)-affiliated pediatricians.

RESULTS

Fifty-three UKCCSG- and 78 POG-affiliated pediatricians responded. Thirty-two UKCCSG and 51 POG respondents had previously entered at least one child into a phase I study. Overall, respondents believed that parents entered their children for medical benefit, altruism, and hope of cure. Although many respondents believed that children could benefit from medical improvement, feelings of altruism, and maintenance of hope, the chance of cure or complete remission was thought to be small. Similarly, parents were thought to potentially benefit through altruism and maintenance of hope. Whereas 83% of UKCCSG respondents indicated that phase I trials were associated with ethical difficulties, this was a concern for 48% of POG respondents. The main ethical concerns of respondents were risk of toxicity, consent of the child, unrealistic hope, and coercion.

CONCLUSION

The respondents in this survey expressed mainly ethical concerns regarding the conduct of phase I trials and had realistic expectations of the potential for toxicity and benefit for those children who participate in these studies.

Gain of chromosome arm 17q and adverse outcome in patients with neuroblastoma

BACKGROUND

Gain of genetic material from chromosome arm 17q (gain of segment 17q21-qter) is the most frequent cytogenetic abnormality of neuroblastoma cells. This gain has been associated with advanced disease, patients who are > or =1 year old, deletion of chromosome arm 1p, and amplification of the N-myc oncogene, all of which predict an adverse outcome. We investigated these associations and evaluated the prognostic importance of the status of chromosome 17.

METHODS

We compiled molecular cytogenetic analyses of chromosome 17 in primary neuroblastomas in 313 patients at six European centers. Clinical and survival information were collected, along with data on 1p, N-myc, and ploidy.

RESULTS

Unbalanced gain of segment 17q21-qter was found in 53.7 percent of the tumors, whereas the chromosome was normal in 46.3 percent. The gain of 17q was characteristic of advanced tumors and of tumors in children > or =1 year of age and was strongly associated with the deletion of 1p and amplification of N-myc. No tumor showed amplification of N-myc in the absence of either deletion of 1p or gain of 17q. Gain of 17q was a significant predictive factor for adverse outcome in univariate analysis. Among the patients with this abnormality, overall survival at five years was 30.6 percent (95 percent confidence interval, 21 to 40 percent), as compared with 86.0 percent (95 percent confidence interval, 78 to 91 percent) among those with normal 17q status. in multivariate analysis, gain of 17q was the most powerful prognostic factor, followed by the presence of stage 4 disease and deletion of 1p (hazard ratios, 3.4, 2.3, and 1.9, respectively).

CONCLUSIONS

Gain of chromosome segment 17q21-qter is an important prognostic factor in children with neuroblastoma.

Cloning and characterisation of the gene for the large subunit of the DNA primase from Drosophila melanogaster

We have cloned the gene for the large subunit of the DNA primase from Drosophila melanogaster, and mapped it to position 77b on chromosome 3. The central region of the protein shows high similarity with homologues from other species, but the N- and C-termini diverge. The protein is enriched in replicating tissues, and consistent with this the region upstream of the gene contains close matches to the sites of two transcription factors - Dref and E2f - which have been implicated in controlling proliferation-associated genes.

Ifosfamide-containing chemotherapy in Ewing's sarcoma: The Second United Kingdom Children's Cancer Study Group and the Medical Research Council Ewing's Tumor Study

PURPOSE

To investigate the possibility that the substitution of ifosfamide for cyclophosphamide therapy for Ewing's sarcoma will improve survival over that seen in the first United Kingdom Children's Cancer Study Group (UKCCSG) Ewing's tumor study (ET-1).

PATIENTS AND METHODS

Between 1987 and 1993,243 patients (138 men or boys) were entered onto the study. The median age was 13.5 years (range, 1.5 to 27 years). The median follow-up was 58 months. Chemotherapy included four courses of vincristine 2 mg/m2; ifosfamide 9 g/m2; and doxorubicin 60 mg/m2 administered every 3 weeks. Treatment of the primary tumor was with surgery and/or radiotherapy followed by ifosfamide 6 g/m2; doxorubicin 60 mg/m2; and vincristine 2 mg/m2; with actinomycin D 1.5 mg/m2 substituted for doxorubicin after a total dose of 420 mg/m2.

RESULTS

Two hundred one patients had no metastases. One hundred eighteen patients had tumors of the axial skeleton and 125 patients had limb primary tumors. The major toxicities were hematologic and infective, but there were no toxic deaths. The overall survival rate was 62% (95% confidence interval [CI], 56 to 69) and relapse-free survival (RFS) 56% (95% CI, 49 to 62). For those with no metastases at diagnosis, the RFS rate was 62% and for those with metastases, 23%. Multivariate analysis showed age and site to have a significant effect on RFS. Pelvic sites had the worst RFS rate of 41%; other axial sites, 55%; and extremity tumors, 73%. Age younger than 10 years had an RFS rate of 86% versus 55% for older patients. The local relapse rate for axial tumors was 20% and for limb primary tumors was 2.4%.

CONCLUSION

The 5-year survival rate of 62% is improved compared with the 44% survival rate achieved in ET-1. This is probably caused by the use of higher doses of ifosfamide compared with relatively low doses of cyclophosphamide in ET-1.

Gain of chromosome arm 17q predicts unfavourable outcome in neuroblastoma patients. U.K. Children's Cancer Study Group and the U.K. Cancer Cytogenetics Group

Gain of chromosome arm 17q has recently been reported in neuroblastoma tumours. We analysed 17q status in relation to other known prognostic features and clinical outcome in a series of 45 tumours. Chromosome 17 status was detected by cytogenetic analysis, fluorescence in situ hybridisation (FISH) anc comparative genomic hybridisation (CGH) and correlated with other clinical and genetic factors. Survival analysis was calculated by the Kaplan-Meier estimation. Twenty-eight out of 45 tumours showed 17q gain, and this was associated with established indicators of poor prognosis; stage 4 disease (P < 0.001), age above 1 year at diagnosis (P < 0.001), 1p deletion (P < 0.01), MYCN amplification (P = 0.03) and diploidy/tetraploidy (P = 0.04). 17q gain was associated with poor outcome: 3-year survival was 13.5% compared with 100% for tumours without 17q gain (P = 0.0001); and progression-free survival (PFS) was 8.1% after 3 years compared with 83% for 17q normal tumours (P = 0.0001). PFS in 28 MYCN non-amplified patients indicated that 17q status has discriminatory power within this group: PFS 0% for 17q gain (n = 14) versus 100% for normal 17q (n = 14) (P = 0.0001). This study indicates that 17q changes have prognostic significance in neuroblastoma and should be a target for molecular cytogenetic detection at diagnosis.

Molecular and cellular characterization of CRP1, a Drosophila chromatin decondensation protein

CRP1, a Drosophila nuclear protein that can catalyze decondensation of demembranated Xenopus sperm chromatin was cloned and its primary structure was deduced from cDNA sequence. Alignment of deduced amino acid sequence with published sequences of other proteins revealed strong homologies to Xenopus nucleoplasmin and NO38. CRP1 is encoded by one or several closely related genes found at a single locus, position 99A on the right arm of chromosome 3. CRP1 mRNA is expressed throughout Drosophila development; it is highest during oogenesis and early embryogenesis. mRNA levels correlate closely with levels of protein expression measured previously. Results of chemical crosslinking indicate that CRP1 is either tetrameric or pentameric; similar ambiguity was revealed by direct visualization using scanning transmission electron microscopy. Consistent with previously published results, parallel crosslinking studies of Xenopus nucleoplasmin suggested a pentameric structure. Scanning transmission electron microscopic examination after negative staining revealed that CRP1 and Xenopus nucleoplasmin are morphologically similar. CRP1 is able to substitute for nucleoplasmin in Xenopus egg extract-mediated sperm chromatin decondensation. In vitro, CRP1-induced decondensation is accompanied by direct binding of CRP1 to chromatin.

DNA replication-related elements cooperate to enhance promoter activity of the drosophila DNA polymerase alpha 73-kDa subunit gene

An analysis was carried out on the promoter region of the Drosophila DNA polymerase alpha 73-kDa subunit gene and the factor(s) activating the promoter. Transcription initiation sites were newly identified in the region downstream of the previously determined sites. Full promoter activity resided within the region from -285 to +129 base pairs with respect to the newly determined major site. Within this region, we found three sequences identical or similar to the DNA replication-related element (DRE), 5'-TATCGATA, which is known as a common promoter-activating element for the Drosophila DNA polymerase alpha 180-kDa subunit gene and the proliferating cell nuclear antigen gene. These sites were located at positions -77 to -70 (DREalpha-I), -44 to -37 (DREalpha-II), and +3 to +10 (DREalpha-III). Footprinting analysis using the recombinant DRE-binding factor (DREF) or Kc cell nuclear extract demonstrated that DREF can bind to all three DRE-related sites. Introduction of mutation in even one of the three DRE-related sequences caused extensive reductions of the promoter activity and also the DREF-binding activity of the promoter-containing fragment. The results indicate that the three DREF-binding sites cooperate to enhance promoter activity of the DNA polymerase alpha 73-kDa subunit gene.

An unusual source for an outbreak of methicillin-resistant Staphylococcus aureus on an intensive therapy unit

During a four-month period, six patients on an intensive therapy unit became colonized or infected with methicillin-resistant Staphylococcus aureus (MRSA). Four of these patients were colonized by the Epidemic MRSA strain 15 (EMRSA 15). The outbreak was characterized by the fact that all four of these patients were nursed in the same bed on the unit before acquisition of the organism. Investigation of the outbreak led the authors to believe that the source of the MRSA may have been the exhaust ducting of the adjacent isolation room ventilation system which allowed the organisms to enter the unit via a partially open window positioned above that particular bed. The cycle was broken once the ventilation system was repaired and the window above the bed was properly sealed.

Isolation and characterisation of dhel II, a DNA helicase from Drosophila melanogaster embryos stimulated by Escherichia coli-type single-stranded-DNA-binding proteins

We have purified a DNA helicase from Drosophila embryos by following unwinding activity during the purification of the cellular single-stranded DNA-binding protein dRP-A. This DNA helicase unwinds DNA 5' to 3', has a salt-tolerant activity, and has a preference for purine triphosphates as cofactors for the unwinding reaction. The purified enzyme consists of a single polypeptide of 120 kDa, which cosediments with the helicase activity. Sedimentation analysis suggests that this polypeptide exists as a monomer under high and low salt conditions. Dhel II is able to unwind long stretches of DNA, but with decreased efficiency. Addition of Escherichia coli-like single-stranded DNA-binding proteins stimulates the unwinding activity at least 10-fold on substrates greater than 200 nucleotides. In particular, the mitochondrial single-stranded DNA-binding protein isolated from Drosophila embryos is able to stimulate unwinding by dhel II. These properties show that the helicase described is different from another Drosophila helicase dhel I; it has thus has been classified as dhel II.

Purification and characterisation of a DNA helicase, dheI I, from Drosophila melanogaster embryos

We have purified a DNA helicase (dhel l) from early Drosophila embryos. dhel l co-purifies with the single-stranded DNA binding protein dRP-A over two purification steps, however, the proteins can be separated by their different native molecular weight, with dhel l activity co-sedimenting with a polypeptide of approximately 200 kDa and a sedimentation coefficient of 8.6 S. The enzyme needs ATP hydrolysis and divalent cations for displacement activity. It is very salt sensitive, having a Mg2+ optimum of 0.5 mM and being inhibited by NaCl concentration > 10 mM. Dhel l moves 5'-->3' on the DNA strand to which it is bound. Unwinding activity decreases with increasing length of the double-stranded region suggesting a distributive mode of action. However, addition of dRP-A to the displacement reaction stimulates the activity on substrates with >300 nucleotides double-stranded region suggesting a specific interaction between these two proteins.

Antimicrobial prescribing in patients on haemofiltration

Continuous haemo(dia)filtration techniques as a means of extracorporeal renal replacement therapy are being used more and more, especially on intensive care units. The effect of intermittent haemodialysis on the pharmacokinetics of systemic antibiotics is well documented and advice is provided in the drug data sheets regarding dosage, timing and additional doses (post haemodialysis). Continuous haemofiltration significantly alters the handling of these same antibiotics compared with haemodialysis, such that if the advice given for 'haemodialysis' is used for patients on haemofiltration, under-dosing the patient may lead to sub-therapeutic antibiotic levels. The reasons for these differences are discussed and suggested dosage modifications are given for commonly used antimicrobials based on available published data.

Mitochondrial single-stranded DNA-binding protein from Drosophila embryos. Physical and biochemical characterization

Using a stringent purification procedure on single-stranded DNA cellulose, we have isolated the mitochondrial single-stranded DNA-binding protein from Drosophila melanogaster embryos. Its identity is demonstrated by amino-terminal sequencing of the homogeneous protein and by its localization to a mitochondrial protein fraction. The mitochondrial protein is immunologically and biochemically distinct from the previously characterized nuclear replication protein A from Drosophila (Mitsis, P. G., Kowalczykowski, S. C., and Lehman, I. R. (1993) Biochemistry 32, 5257-5266; Marton, R. F., Thömmes, P., and Cotterill, S. (1994) FEBS Lett. 342, 139-144). It consists of a single polypeptide of 18 kDa, which is responsible for the DNA binding activity. Sedimentation analysis suggests that D. melanogaster mitochondrial single-stranded DNA-binding protein exists as a homo-oligomer, possibly a tetramer, in solution. The protein binds to DNA in its single-stranded form with a strong preference over double-stranded DNA or RNA, and binds to polypyrimidines preferentially over polypurines. Drosophila mitochondrial single-stranded DNA-binding protein exhibits a greater affinity for long oligonucleotides as compared to short ones, yet does not show high cooperativity. Its binding site size, determined by competition studies and by fluorescence quenching, is approximately 17 nucleotides under low salt conditions, and increases in the presence of greater than 150 mM NaCl. The homogeneous protein stimulates the activity of mitochondrial DNA polymerase from D. melanogaster embryos, increasing dramatically the rate of initiation of DNA synthesis on a singly primed DNA template.

Genetic analysis of the terminal 8-bp inverted repeats of transposon Tn7

Mutations in the terminal 8-bp (5'-T1G2T3G4G5G6C7G8-3') of the inverted repeats of the bacterial transposon, Tn7, were analysed by measuring Tn7 transposition to the attachment site, attTn7. The mutation, C2, present at either end of Tn7 reduces transposition only threefold, but in the double mutant, with C2 at both ends of Tn7, no transposition is detected. C6 mutations have no effect on transposition frequency. Replacement with 5'-A3C4G5C6G7C8-3' at the right end of Tn7 apparently abolishes transposition; yet in the double mutant, where the inverted repeats are restored by substituting this sequence at both ends of Tn7, transposition is partially rescued. This suggests that the mechanism of Tn7 transposition requires communication between the two ends. Tn7 transposition has always been seen to generate a 5-bp target duplication. This is presumed to result from a staggered cut, plus repair synthesis during transposition. We found that two of our right-end mutants, C2 and C6, sometimes yielded a 6-bp target duplication. This observation implies that cleavage of the target site might also involve interaction with the donor ends which, when mutant, relax the specificity for target-site cleavage.

DF 31, a sperm decondensation factor from Drosophila melanogaster: purification and characterization

We have purified to homogeneity a Drosophila protein which is able to decondense Xenopus sperm chromatin. This protein, which we have called DF 31, is a heat-stable phosphoprotein which displays a molecular weight of 31 kDa on SDS-PAGE, but which has an apparent molecular weight of > 200 kDa on gel filtration. We show that DF 31 decondenses sperm DNA by displacement of sperm-specific proteins. In addition to its sperm decondensation activity, DF 31 is also able to facilitate nucleosome loading on both decondensed sperm DNA and on naked DNA template. The reaction as catalysed by DF 31 is quite efficient; however, the nucleosomes appear to be loaded randomly onto the DNA, not in regular arrays. Although the mechanism by which DF 31 aids nucleosome loading is not yet clear, it most probably occurs through binding of DF 31 to core histones.

Primary extra-thoracic T-cell non-Hodgkin's lymphoma of childhood. The United Kingdom Children's Cancer Study Group

Between 60-80% of non-Hodgkin's lymphoma (NHL) of T-cell lineage in children, present with primary mediastinal disease. On current therapy, this and nodal low-stage disease are associated with a relatively favourable outcome. In order to evaluate whether the primary site of disease is a prognostic factor, we examined the clinical characteristics and outcome of 36 children with primary extrathoracic T-cell NHL diagnosed during a 7-year period by the United Kingdom Children's Cancer Study Group. Eight, eight, 11 and nine children had stage I, II, III and IV disease, respectively. The primary site of disease was nodal in 22, skin and subcutaneous tissue in five, abdominal in three, bone in three and at other sites in three. Eighteen (50%) had lymphoblastic, ten (28%) large cell anaplastic (LCA) and seven (19%) pleomorphic large or medium cell (PLC) tumours. In one child the histology was inconclusive. All children with lymphoblastic, three with LCA, three with PLC disease and one with unknown histology were treated on intensive, sustained and continuous leukaemia protocols. Ten, seven with LCA and three with PLC, were treated on regimens of short duration pulsed therapy and one child with PLC with radiotherapy only. The three-year event-free survival (EFS) was 78% for the group as a whole. Those with stage IV lymphoblastic disease had a significantly worse prognosis (p < 0.0005). Primary site of disease, gender, therapeutic regimen and histology were not predictive for survival. In primary extrathoracic T-cell NHL with lymphoblastic histology, leukaemia-like therapy is recommended. For non-lymphoblastic disease, in particular the Ki-1 positive tumours, evidence suggests that short duration pulsed therapy may be optimal.

Results of the United Kingdom Children's Cancer Study Group first Wilms' Tumor Study

PURPOSE

The first United Kingdom Children's Cancer Study Group (UKCCSG) Wilms' Tumor Trial (UKW1) applied treatment regimens stratified by stage and histology in accordance with National Wilms' Tumor Study (NWTS) criteria, seeking to reduce treatment of low-stage, favorable-histology (FH) tumors without impairing survival and to improve prognosis of stage III and IV (FH) and unfavorable-histology (UH) tumors with more intensive chemotherapy.

PATIENTS AND METHODS

Three hundred eighty-four consecutively diagnosed patients with Wilms' tumor were recruited from the 20 UKCCSG centers and Oslo, Norway, between January 1980 and June 1986. The regimen for stage I patients was vincristine (Vcr) only, while stage II patients received Vcr and dactinomycin (Act-D). Stage III patients received three-drug therapy and stage IV and UH patients four-drug regimens. Act-D was given as pulsed doses of 1.5 mg/m2 every 3 or every 6 weeks. No lung irradiation was used in stage IV patients. No randomized comparisons were attempted. End points were survival and event-free survival (EFS).

RESULTS

Survival at 6 years in FH patients was 96% for stage I, 93% for stage II, 83% for stage III, 65% for stage IV, and 50% for UH patients of all stages.

CONCLUSION

Vcr alone is as effective for stage I FH tumors as the two-drug regimen used in the NWTS and International Society of Pediatric Oncology (SIOP) studies. Fractionation of Act-D is unnecessary. The poorer results for stage IV FH and UH patients compared with the NWTS may be due to treatment differences, such as the use of lung irradiation for stage IV FH patients in NWTS3, and/or to case selection bias.

The 50-kDa primase subunit of Drosophila melanogaster DNA polymerase alpha. Molecular characterization of the gene and functional analysis of the overexpressed protein

The gene encoding the 50-kDa subunit of Drosophila melanogaster DNA polymerase alpha has been cloned. A comparison of the predicted polypeptide sequence of the Drosophila protein with the equivalent subunits from mouse and yeast suggests that they are closely related and defines three conserved regions which are likely to be important for enzyme activity. The expression patterns of both the 50-kDa protein and its transcript (a single RNA message of 1.6 kilobases) throughout development are consistent with a role of the protein in DNA replication. When overexpressed and purified the 50-kDa subunit displays DNA primase activity. The products of the reaction, mainly oligoribonucleotides 12-14 nucleotides in length, plus dimers and some trimers, are similar to those synthesized by either the intact DNA polymerase alpha, or the biochemically isolated primase heterodimer. The isolated primase also shows similar sensitivity to antibodies, magnesium and monovalent cations, and the same nucleotide requirements as complexed forms of the primase. The isolated subunit, however, is more thermally labile, suggesting a role for the additional subunits in DNA polymerase alpha in stabilizing the primase activity of the 50-kDa primase subunit.

Purification and characterisation of dRP-A: a single-stranded DNA binding protein from Drosophila melanogaster

Replication protein A (RP-A) is an essential single-stranded DNA binding protein (SSB) involved in the initiation and elongation phases of eukaryotic DNA replication. It has the ability to bind single-stranded DNA extremely tightly and possesses a characteristic hetero-trimeric structure. Here we present a method for the purification of RP-A from Drosophila melanogaster embryos. Drosophila RP-A (dRP-A) has subunits of about 66, 31 and 8 kDa, in line with analogues from other species. It binds single-stranded DNA very tightly via the large subunit. The complete protein has at least a 10- to 20-fold preference for single-stranded DNA over double-stranded DNA and it appears that binding is only weakly co-operative. Band shift experiments suggest that it has an approximate site covering the size of 16 nucleotides or less, however, it shows a greater affinity for long oligonucleotides than for short ones. We also demonstrate that dRP-A can stimulate the activity of its homologous DNA polymerase alpha in excess of 20 fold. Analysis of the protein's abundance during embryo development indicates that it varies in a manner akin to other replication proteins.

Treatment of advanced stage T cell lymphoblastic lymphoma: results of the United Kingdom Children's Cancer Study Group (UKCCSG) protocol 8503

Ninety-five unselected patients with stage III and IV T cell lymphoblastic lymphoma were treated according to the United Kingdom Children's Cancer Study Group protocol 8503. This was a continuous, intensive leukaemia type regimen including cranial irradiation (18 Gy in 10 fractions) and continuing chemotherapy for 2 years identical to the concurrent Medical Research Council ALL protocol. Four-year event-free survival was 65% (95% CI 50-80%) with no significant difference between stage III and stage IV cases. 4.2% of patients died of infection or non-tumour related events. Following relapse salvage was unlikely without high dose chemotherapy and bone marrow rescue. These results show an improvement over previous U.K. studies but we need to continue to search for subsets of patients with resistant disease for whom even more intensive therapy possibly combined with bone marrow rescue is required.

Cloning of the gene for the 73 kD subunit of the DNA polymerase alpha primase of Drosophila melanogaster

We have isolated both cDNA and genomic clones for the 73 kDa subunit of the DNA polymerase alpha primase of Drosophila melanogaster. Analysis of these clones has identified an open reading frame of 1959 bases coding for a protein of 72.5 kDa. Northern analysis has shown the mRNA for the gene to be approximately 2.5 kb, and comparison of the cDNA and the genomic clones shows that the coding region of the gene lacks introns. The 5' end of the transcript has been mapped by primer extension, and the position of the gene in the genome mapped using in situ analysis. Computer analysis has been carried out on both coding and non coding regions of the gene. The protein sequence shows some homology to the analogous subunit in the S. cerevisiae DNA polymerase alpha, however a search of the data banks failed to reveal other homologies, or provide any clues as to the function of the protein. Analysis of the non-coding regions indicates some potential control regions for the gene. The 73 kDa protein has been overproduced, but a preliminary analysis failed to reveal any enzymatic activities.

Molecular characterisation of the gene for the 180 kDa subunit of the DNA polymerase-primase of Drosophila melanogaster

We have cloned and sequenced the gene for the 180 kDa subunit of the a polymerase from Drosophila melanogaster. The protein shows high similarity to the 180 kDa subunits from other species. Comparative expression analysis for the transcript, protein and enzymic activity suggests that control occurs mainly at the level of transcription. In situ analyses of the RNA suggest that high levels of the transcript are synthesised in the ovaries and deposited uniformly in the egg. Immunolocalisation of the 180 kDa polypeptide in whole embryos shows that its location is mainly nuclear; however, dispersal of the protein can be seen to occur during mitotic phases of the cell cycle.

Characterisation of a tryptic peptide from human placental ribonuclease inhibitor which inhibits ribonuclease activity

Affinity-purified human placental ribonuclease inhibitor (PRI) was digested by trypsin. Subsequent fractionation of the hydrolysate by HPLC yielded 44 fractions, 3 of which retained the ability to inhibit ribonuclease. One of these, the most active, was a 15 amino acid peptide which had an amino acid composition corresponding to a tryptic fragment of PRI. This peptide was synthesised, and preliminary experiments were carried out on its interactions with ribonuclease. These experiments suggested that the behaviour of the peptide in terms of effect of pH, and effect of salt concentration were similar to the protein from which it was derived. These studies together with the strategic positioning of the peptide in the sequence of the ribonuclease inhibitor, suggest that this segment of PRI has an important role in the inhibitory activity of the intact protein.

Overproduction of four functionally active proteins, TnsA, B, C, and D, required for Tn7 transposition to its attachment site, attTn7

The bacterial transposon Tn7 encodes five trans-acting transposition genes, tnsA, B, C, D, and E. Tn7 requires four of these genes, tnsA, B, C, and D, for a novel transposition pathway: high-efficiency site-specific transposition to a chromosomal attachment site, attTn7. Plasmids that individually allow inducible overexpression of proteins from the first initiation codon of four of these genes were constructed. Escherichia coli strains carrying these plasmids were used to overexpress the TnsA, B, C, and D proteins. The abundance and the apparent relative molecular mass of these proteins were examined and the latter was compared to those predicted from wild-type Tn7. The functionality of these proteins, encoded by an overexpression construct, was demonstrated by the fact that they could efficiently trans-complement a defective mini-Tn7 carrying only the cis-essential Tn7 termini in an in vivo assay for transposition to attTn7.

DNA replication in cell-free extracts from Drosophila melanogaster

We have developed an efficient in vitro replication system from 0-2 h Drosophila melanogaster embryos. Demembranated Xenopus sperm DNA when incubated in such an extract first becomes enclosed in a nucleus-like structure with a nuclear envelope and a karyoskeleton. It then undergoes one round of semiconservative replication--this replication appears completely dependent on nuclear formation. Up to 30% of input DNA is nucleated in one reaction. Efficient nuclear formation and replication are dependent on a cold treatment step, prior to disruption of the embryos. They also depend on the age of the embryos used. Extracts from older embryos (0-5 h) are capable of nuclear formation, although at a much reduced efficiency, and repair synthesis, but seem to have lost the ability to initiate DNA replication. In addition to replicating sperm DNA this system appears capable of carrying out semi-conservative replication on some plasmids. However, it cannot use these to trigger nuclear formation; replication is only seen if the plasmids are coincubated with sperm DNA. The in vitro formed nuclei have not been observed to trigger nuclear envelope breakdown and entry into mitosis. However, they can re-replicate the DNA if the nuclei are permeabilized. This system should be a useful complement to the previously isolated Xenopus in vitro replication system. In addition the amenability of Drosophila to genetic study should open up new approaches not previously possible with Xenopus.

Purification and characterisation of the TnsB protein of Tn7: a transposition protein that binds to the ends of Tn7

Tn7, a large bacterial transposon encodes 5 proteins required for its transposition. We report a rapid and easy purification of one of these proteins, TnsB, from an overexpression strain. This protein was shown to bind to the ends of Tn7, in a bandshift assay, in two distinct stages as a function of protein concentration. DNasel footprinting at each end of Tn7 showed that the TnsB recognition sequence, a set of 22 bp repeats, plus Tn7 termini are protected. Binding of TnsB appeared cooperative but was only observed above a threshold concentration of protein. ATP and Mg2+ had no effect on the pattern of protection, nor did addition of other Tn7-encoded proteins. Hydroxyl radical footprinting, performed at the right end, showed that TnsB binds preferentially to one side of the DNA helix.

DNA polymerase-primase from embryos of Drosophila melanogaster. The DNA polymerase subunit

The DNA polymerase-primase from Drosophila melanogaster has been separated into its constituent polymerase and primase subunits by sedimentation in glycerol gradients containing 50% ethylene glycol. Both activities have been obtained in good yield. The properties of the 182-kDa polymerase subunit are similar to those of the intact four-subunit enzyme. However, there are three significant differences. (i) The polymerase activity of the 182-kDa subunit shows an increased thermolability; (ii) the pause sites during replication of singly primed, single-stranded circular DNA by the 182-kDa subunit are altered; and (iii) unlike the intact enzyme, the 182-kDa subunit is highly processive in the presence of the single-stranded DNA-binding protein of Escherichia coli.

DNA polymerase-primase from embryos of Drosophila melanogaster. DNA primase subunits

The primase associated with the DNA polymerase-primase of Drosophila melanogaster fails to show enzymatic turnover. However, it does show turnover when dissociated from the intact polymerase-primase. Both forms of the enzyme can catalyze the synthesis of primers that are not complementary to the DNA template. Like the intact enzyme, the isolated primase synthesizes primers of a unique chain length; however, they are twice as long as those synthesized by the polymerase-primase. The activity of the primase separated from the polymerase-primase is similar in all other respects to the intact polymerase-primase.