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Background: Our previous laboratory and clinical data suggested that one mechanism underlying the development of platinum resistance in ovarian cancer is the acquisition of DNA methylation. We therefore tested the hypothesis that the DNA hypomethylating agent 5-aza-2'-deoxycytodine (decitabine) can reverse resistance to carboplatin in women with relapsed ovarian cancer.Methods: Patients progressing 6-12 months after previous platinum therapy were randomised to decitabine on day 1 and carboplatin (AUC 6) on day 8, every 28 days or carboplatin alone. The primary objective was response rate in patients with methylated hMLH1 tumour DNA in plasma.Results: After a pre-defined interim analysis, the study closed due to lack of efficacy and poor treatment deliverability in 15 patients treated with the combination. Responses by GCIG criteria were 9 out of 14 vs 3 out of 15 and by RECIST were 6 out of 13 vs 1 out of 12 for carboplatin and carboplatin/decitabine, respectively. Grade 3/4 neutropenia was more common with the combination (60% vs 15.4%) as was G2/3 carboplatin hypersensitivity (47% vs 21%).Conclusions: With this schedule, the addition of decitabine appears to reduce rather than increase the efficacy of carboplatin in partially platinum-sensitive ovarian cancer and is difficult to deliver. Patient-selection strategies, different schedules and other demethylating agents should be considered in future combination studies. [ABSTRACT FROM AUTHOR]

Background:Our previous laboratory and clinical data suggested that one mechanism underlying the development of platinum resistance in ovarian cancer is the acquisition of DNA methylation. We therefore tested the hypothesis that the DNA hypomethylating agent 5-aza-2′-deoxycytodine (decitabine) can reverse resistance to carboplatin in women with relapsed ovarian cancer.Methods:Patients progressing 6-12 months after previous platinum therapy were randomised to decitabine on day 1 and carboplatin (AUC 6) on day 8, every 28 days or carboplatin alone. The primary objective was response rate in patients with methylated hMLH1 tumour DNA in plasma.Results:After a pre-defined interim analysis, the study closed due to lack of efficacy and poor treatment deliverability in 15 patients treated with the combination. Responses by GCIG criteria were 9 out of 14 vs 3 out of 15 and by RECIST were 6 out of 13 vs 1 out of 12 for carboplatin and carboplatin/decitabine, respectively. Grade 3/4 neutropenia was more common with the combination (60% vs 15.4%) as was G2/3 carboplatin hypersensitivity (47% vs 21%).Conclusions:With this schedule, the addition of decitabine appears to reduce rather than increase the efficacy of carboplatin in partially platinum-sensitive ovarian cancer and is difficult to deliver. Patient-selection strategies, different schedules and other demethylating agents should be considered in future combination studies. [ABSTRACT FROM AUTHOR]

Many cancers show a low level of microsatellite slippage and are labelled MSI-L (microsatellite instability-low). However, it is unclear whether this slippage can be attributed to some underlying genetic change that results in a mutator phenotype, analogous to mismatch repair deficiency in MSI-H cancers, or whether the apparent instability is the result of relatively frequent normal somatic slippage. Here, we have used a mathematical model of microsatellite slippage during cancer growth to estimate the degree of microsatellite slippage expected in a cancer due to normal somatic slippage. We compared the model to the slippage observed in 42 non-MSI-H cancers that were macro-dissected into four distinct regions and genotyped at N = 9 microsatellite loci. When the slippage rate was set at µ = 10−5 per locus per division, ten cancers showed a level of slippage in at least one region that was too severe to be expected from normal somatic slippage alone, suggesting that these cancers had acquired MSI-L. Only one of these ten cancers had putative MSI-L in all four regions. When we considered a slightly higher slippage rate of µ = 5 × 10−5, none of the cancers showed a degree of slippage that could not be reasonably explained by normal somatic slippage. Counting the number of 'unstable' loci was a poor indicator of putative MSI-L status. We conclude that most low-level microsatellite instability in colorectal cancers can be explained without requiring an elevated slippage rate during neoplastic development, and hence there is little evidence for a discrete MSI-L group of cancers. Putative MSI-L status is indicated by the presence of at least one locus that has multiple alleles that differ by at least five motif repeats from the germline. If an underlying genetic change does cause MSI-L, it appears to be a relatively uncommon event that occurs late in oncogenesis. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A literature search was undertaken for evidence of the effect of succinylcholine (SCH) on the intracranial pressure (ICP) of patients with acute brain injury and whether pretreatment with a defasciculating dose of competitive neuromuscular blocker is beneficial in this patient group. The authors could find no definitive evidence that SCH caused a rise in ICP in patients with brain injury. However, these studies were often weak and small. For those patients suffering acute traumatic brain injury the authors could find no studies that investigated the issue of pretreatment with defasciculating doses of competitive neuromuscular blockers and their effect on ICP in patients given SCH. There is level 2 evidence that SCH caused an increase in ICP for patients undergoing neurosurgery for brain tumours with elective anaesthesia and that pretreatment with defasciculating doses of neuromuscular blockers reduced such increases. It is unknown if this affects neurological outcome for this patient group. [ABSTRACT FROM AUTHOR]

Traditionally, enzyme transient kinetics have been studied by the stopped-flow and rapid quench-flow (QF) methods. Whereas stopped-flow is the more convenient, it suffers from two weaknesses: optically silent systems cannot be studied, and when there is a signal it cannot always be assigned to a particular step in the reaction pathway. QF is a chemical sampling method; reaction mixtures are aged for a few milliseconds or longer, ‘stopped’ by a quenching agent and the product or the intermediate is measured by a specific analytical method. Here we show that by exploiting the array of current analytical methods and different quenching agents, the QF method is a key technique for identifying, and for characterising kinetically, intermediates in enzyme reaction pathways and for determining the order by which bonds are formed or cleaved by enzymes acting on polymer substrates such as DNA. [ABSTRACT FROM AUTHOR]

Aims The Pro12Ala polymorphism in the PPARG gene alters amino acid sequence and has shown consistent association with susceptibility to Type 2 diabetes in several populations. The present study makes use of large, well-characterized case-control resources to enhance understanding of this susceptibility effect by examining related traits, such as body mass index (BMI), waist-hip ratio and age at diagnosis.Methods The Pro12Ala variant was genotyped in two UK case samples, ascertained for positive family history and/or early onset of Type 2 diabetes (combined n = 971); and in 1257 ethnically matched control subjects.Results There were significant associations of the Pro12Ala single nucleotide polymorphism (SNP) genotypes with diabetes in both case-control comparisons (P = 0.025 and P = 0.039). Comparing individuals homozygous for the Pro allele, with those carrying an Ala allele, the combined odds ratio for diabetes was 1.40 (95% CIs, 1.12-1.76, P = 0.0031). There was no association between the variant and either waist-hip ratio or age at diagnosis. Proline homozygosity was associated with increased BMI in one patient group (P = 0.013) and decreased BMI in the other (P = 0.038).Conclusions This study confirms that variation within PPARG influences susceptibility to Type 2 diabetes in UK samples. However, the relationship between PPARG variation and BMI is more complex, and studies in much larger sample sets will be required to more precisely characterize the effect of this variant on adiposity. [ABSTRACT FROM AUTHOR]

Aims The Pro12Ala polymorphism in the PPARG gene alters amino acid sequence and has shown consistent association with susceptibility to Type 2 diabetes in several populations. The present study makes use of large, well-characterized case-control resources to enhance understanding of this susceptibility effect by examining related traits, such as body mass index (BMI), waist–hip ratio and age at diagnosis. Methods The Pro12Ala variant was genotyped in two UK case samples, ascertained for positive family history and/or early onset of Type 2 diabetes (combined n = 971); and in 1257 ethnically matched control subjects. Results There were significant associations of the Pro12Ala single nucleotide polymorphism (SNP) genotypes with diabetes in both case-control comparisons ( P = 0.025 and P = 0.039). Comparing individuals homozygous for the Pro allele, with those carrying an Ala allele, the combined odds ratio for diabetes was 1.40 (95% CIs, 1.12–1.76, P = 0.0031). There was no association between the variant and either waist–hip ratio or age at diagnosis. Proline homozygosity was associated with increased BMI in one patient group ( P = 0.013) and decreased BMI in the other ( P = 0.038). Conclusions This study confirms that variation within PPARG influences susceptibility to Type 2 diabetes in UK samples. However, the relationship between PPARG variation and BMI is more complex, and studies in much larger sample sets will be required to more precisely characterize the effect of this variant on adiposity. [ABSTRACT FROM AUTHOR]

Aims/hypothesis: The proinflammatory cytokine TNF-α has been implicated in the pathogenesis of insulin resistance and type 2 diabetes, and variation in the gene encoding TNF-α (TNF) has shown inconsistent associations with susceptibility to both conditions. Additionally, the coding non-synonymous variant T60N in the neighbouring LTA gene has been reported to be associated with type 2 diabetes. The present study aimed to obtain a robust assessment of the role of variation in the tightly linked TNF/LTA region in diabetes susceptibility by genotyping TNF and LTA variants in large case-control resources. Materials and methods: The G-308A and G-238A TNF promoter variants and the LTA T60N polymorphism were genotyped in two UK case samples that were ascertained for positive family history and/or early onset of type 2 diabetes (combined n=858) and in 1,257 ethnically matched controls. Results: There were no significant associations between the T60N, G-308A or G-238A genotype and type 2 diabetes in the combined analysis (exact Cochran —Mantel—Haenszel statistic for ordered genotypes for T60N, p=0.69; for G-308A, p=0.51; for G-238A, p=0.16). Conclusions/interpretation: The present study, one of the largest association analyses yet reported at this locus, provides no evidence that the specific TNF or LTA variants examined influence susceptibility to type 2 diabetes. More comprehensive studies of the TNF/LTA locus in substantially larger sample sets are required to establish whether genome sequence variation at this locus truly influences susceptibility to type 2 diabetes. [ABSTRACT FROM AUTHOR]

Background and aims: O6-methylguanine methyltransferase (MGMT) repairs inappropriately methylated guanine in DNA. MGMT mutations have not previously been reported in Cancers, but in colorectal tumours MGMT promoter methylation is common and has been associated with increased G:C>A:T transitions, a high frequency of K-ras mutations, and low level microsatellite instability (MSI low). However, some have suggested that MGMT changes are background or secondary events, with little importance for tumorigenesis. Methods: We have analysed fresh frozen colorectal cancers and colorectal cancer cell lines for MGM T changes: mutations, allelic loss, and protein expression. Results: Six of 113 cancers harboured somatic missense MGMT mutations, at least three of which probably caused reduced MGMT function and were accompanied by silencing or loss of the wild-type allele. Cancers with pathogenic MGMT mutations tended to harbour G:C>.A:T somatic mutations at other loci. Overall, MGMT expression was reduced or lost in more than half of the cancers. We found no association between MGMT expression and the somatic mutation spectrum at APC, beta-catenin, K-ras, or p53, but decreased MGMT expression was weakly associated with the presence of a G:C>A:T change at any one of these loci. Reduced MGMT expression was not however associated with an increased frequency of K-ras mutations or with MSI low. Conclusion: In summary, we found that mutation of MGMT contributes to decreased protein function. Our findings provide good evidence to show that MGMT changes, including methylation, are selected rather than background events, at least in some cases. Decreased MGMT expression or function probably has a weak or moderate effect on the mutation spectrum in colorectal cancers. [ABSTRACT FROM AUTHOR]

Eukaryotic proteins containing a phosphatidylinositol transfer (PITP) domain can be divided into two groups, one consisting of small soluble 35-kDa proteins and the other those that are membrane-associated and show sequence similarities to the Drosophila retinal degeneration B (rdgB) protein. The rdgB protein consists of four domains, an amino terminal PITP domain, a Ca2+-binding domain, a transmembrane domain and a carboxyl terminal domain that interacts with the protein tyrosine kinase PYK2. Three mammalian phosphatidylinositol transfer protein membrane-associated genes (PITPNM1, 2 and 3) with homology to Drosophila rdgB have previously been described and shown to be expressed in the mammalian retina. These findings and the demonstration that the rdgB gene plays a critical role in the invertebrate phototransduction pathway have led to the mammalian genes being considered as candidate genes for human eye diseases. In order to facilitate the analysis of these genes we have used radiation hybrid mapping and fluorescence in situ hybridization to localize the PITPNM2 and 3 genes to human chromosomes 12p24 and 17p13 respectively and hybrid mapping to confirm the localization of PITPNM1 to chromosome 11q13. We have also determined the genomic organization of both the soluble and membrane-associated Drosophila and human PITP domain-containing genes. Phylogenetic analysis indicates that the two groups arose by gene duplication that occurred very early in animal evolution. Copyright © 2005 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background and aim: Activating β-catenin mutations in exon 3 have been implicated in colorectal tumorigenesis. Although reports to the contrary exist, it has been suggested that β-catenin mutations occur more often in microsatellite unstable (MSI+) colorectal carcinomas, including hereditary non-polyposis colorectal cancer (HNPCC), as a consequence of defective DNA mismatch repair. We have analysed 337 colorectal carcinomas and adenomas, from both sporadic cases and HNPCC families, to provide an accurate assessment of β-catenin mutation frequency in each tumour type. Methods: Direct sequencing of exon 3 of β-catenin. Results: Mutations were rare in sporadic (1/83, 1.2%) and HNPCC adenomas (1/37, 2.7%). Most of the sporadic adenomas analysed (80%) were small (<1 cm), and our data therefore differ from a previous report of a much higher mutation frequency in small adenomas. No oncogenic β-catenin mutations were identified in 34 MSI+ and 78 microsatellite stable (MSI-) sporadic colorectal cancers but a raised mutation frequency (8/44, 18.2%) was found in HNPCC cancers; this frequency was significantly higher than that in HNFCC adenomas (p=0.035) and in both MSI- (p=0.0001) and MSI+ (p=0.008) sporadic cancers. Mutations were more common in higher stage (Dukes' stages C and D) cancers (p = 0.001). Conclusion: Exon 3 β-catenin mutations are associated specifically with malignant colorectal tumours in HNPCC; mutations appear not to result directly from deficient mismatch repair. Our data provide evidence that the genetic pathways of sporadic MSI+ and HNPCC cancers may be divergent, and indicate that mutations in the HNPCC pathway of colorectal tumorigenesis may be determined by selection, not simply by hypermutation. [ABSTRACT FROM AUTHOR]

Congenital colobomata of the eye are important causes of childhood visual impairment and blindness. Ocular coloboma can be seen in isolation and in an impressive number of multisystem syndromes, where the eye phenotype is often seen in association with severe neurological or craniofacial anomalies or other systemic developmental defects. Several studies have shown that, in addition to inheritance, environmental influences may be causative factors. Through work to identify genes underlying inherited coloboma, significant inroads are being made into understanding the molecular events controlling closure of the optic fissure. In general, severity of disease can be linked to the temporal expression of the gene, but this is modified by factors such as tissue specificity of gene expression and genetic redundancy. [ABSTRACT FROM AUTHOR]

Background and aims. This paper draws on recent research conducted in two contrasting NHS hospitals: one a large District General, the other a small Community hospital; to look at hospitals as organizational spaces. This includes both the physical environment as well as how these spaces are inhabited and used. This paper aims to explore the ways in which hospital spaces impact on the working lives of nurses. Methods. The research employed two main methods. Two phases of round the clock non-participant observation were carried out within each hospital, one at the beginning of the research period and one at the end. This generated thick description of the diversity of spaces, as well as individuals' use of space. In addition, more than 50 in-depth unstructured interviews were conducted with both nurses and doctors. Findings. Three aspects of the relationship between nurse and hospital spaces are considered. First, the degree of access that nurses have to the different hospital spaces is limited, and many are confined to the wards in which they work. The high proportion of female nurses working on wards means that there are marked gender differences in access to hospital spaces. There are also marked professional differences when nurses are compared to doctors who have much greater freedom to roam and there are differences in the amount of private space allocated to nurses and doctors. Second, styles of bodily movement in space are also highly differentiated by profession and gender. Third, different spaces have very different meanings attached to them, and this has a strong impact on styles of performance and identity. Attention to space thus offers original insights to nurses working conditions as well as to inter-professional relations. [ABSTRACT FROM AUTHOR]

Objective To assess the role of mitozantrone, active in relapsed prostate cancer, as an adjuvant to hormonal treatment in patients with advanced prostate cancer. Patients and methods Between October 1990 and May 1995, 96 patients were entered into a stratified, randomized, single-institution study of hormonal therapy with a luteinizing hormone-releasing hormone agonist and flutamide, with or without four cycles of adjuvant mitozantrone. Of these, 93 patients were evaluable and the results were analysed in June 1999. Results Patients with localized prostate cancer receiving adjuvant chemotherapy had a higher initial objective response rate (95% vs 53%, P = 0.008) and median survival (80 vs 36 months, P = 0.04) than patients who were treated with hormonal therapy alone. There was no advantage to adjuvant chemotherapy in patients with metastatic prostate cancer. There were insignificant advantages to chemotherapy in overall response rates (55% vs 39%, P = 0.3) and PSA responses (82% vs 64%, P = 0.11). There was no difference between the patient groups in time to treatment failure. Conclusion There was a survival advantage in using adjuvant mitozantrone in patients with locally advanced prostate cancer. Although the study comprised relative few patients, the follow-up period was long and the advantage significant. We recommend that the study be extended to include more patients. [ABSTRACT FROM AUTHOR]

End fragment cloning from a YAC at the D22S134 locus allowed the isolation of a new probe HD7k. This marker detects hemizygosity in two patients previously shown to be dizygous for D22S134. This positions the distal deletion breakpoint in these patients to the sequences within the YAC, and confirms that HD7k is proximal to D22S134. In a search for coding sequences within the region commonly deleted in DGS we have identified a conserved sequence at D22S134. Although no cDNAs have yet been isolated, genomic sequencing shows a short open reading frame with weak similarity to collagen proteins. [ABSTRACT FROM PUBLISHER]

Presents a regional analysis of gender-specific social and spatial mobilities of migrants and nonmigrants in England and Wales from 1971-81. Fortunes of male and female interregional migrants; Role of regional context in shaping gender-specific work history; Spatial differences in the social mobilities of migrants and nonmigrants.

Peutz-Jeghers syndrome (PJS) and juvenile polyposis (JPS) are both characterized by the presence of hamartomatous polyps and increased risk of malignancy in the gastrointestinal tract. Mutations of the LKB1 and SMAD4 genes have been shown recently to cause a number of PJS and JPS cases respectively, but there remains considerable uncharacterized genetic heterogeneity in these syndromes, particularly JPS. The mouse homologue of CDX2 has been shown to give rise to a phenotype which includes hamartomatous-like polyps in the colon and is therefore a good candidate for JPS and PJS cases which are not accounted for by the SMAD4 andLKB1 genes. By analogy with SMAD4, CDX2 is also a candidate for somatic mutation in sporadic colorectal cancer. We have screened 37 JPS families/cases without known SMAD4 mutations, 10 Peutz-Jeghers cases without known LKB1 mutations and 49 sporadic colorectal cancers for mutations in CDX2. Although polymorphic variants and rare variants of unlikely significance were detected, no pathogenic CDX2 mutations were found in any case of JPS or PJS, or in any of the sporadic cancers. [ABSTRACT FROM AUTHOR]

In a series of ten patients affected by DiGeorge syndrome, we screened, by high resolution banding and fluorescent in situ hybridization of a cosmid probe, for microdeletions associated with this syndrome. In the ten patients, a microdeletion was demonstrated by in situ hybridization, but suspected only in two patients by high resolution banding. [ABSTRACT FROM AUTHOR]

A short cut review was carried out to establish whether morphine is better than diamorphine at allieviating chest pain after an acute myocardial infarction. Altogether 66 papers were found using the reported search, of which one presented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results, and study weaknesses of this best paper are tabulated. A clinical bottom line is stated. [ABSTRACT FROM AUTHOR]

This article discusses about assignment of panopsin (OPN3) gene to human chromosome band by fluorescence in situ hybridization and Genebridge4 radiation hybrid panel. The Genebridge4 radiation panel was obtained from the Human Genome Mapping Project Resource Centre of Great Britain. Primers HOF1 and HOR1 were used to amplify DNA from hybrid cell lines. Amplified samples were run on a 2 % agarose gel with appropriate controls. A figure is sketched in the results section of the article which display hybridisation of fluorescently labelled genomic clone PAC 280O20 to metaphase spreads of karyotypically normal human blood lymphocytes.

This article discusses about the BCL2L11 gene mapping to human chromosome band 2p13 with somatic cell and radiation hybrids. The Genebridge4 radiation hybrid panel and the NIGMS HGCR somatic cell hybrid mapping panel were screened using primers Bim125F and Bim359R. Amplified samples were run on a 2% agarose gel with negative controls. Scoring of cell line DNA amplification was made blind to their chromosomal content. Results of somatic cell and radiation hybrid mapping are revealed separately in the article.

Using the mouse gene sequence the human homologue of claudin1 (CLDN 1) was identified. This gene has been mapped to chromosome 3 using PCR on a human and hamster monochromosomal somatic cell hybrid panel and its position refined to band 3q28-q29 using the Genebridge4 radiation hybrid panel. Primers hcF1 and hcR1 were used to amplify DNA from hybrid cell lines. Amplified samples were run on a 2% agarose gel with appropriate controls. All PCR reactions were performed in duplicate. Primers hcF1 and hcR 1only amplified DNA from the chromosome 3 cell line.