Obstetric outcome in women over the age of 40 years

This is a retrospective review of 109 deliveries during a 5-year period in women aged 40 years or over and the results were compared with other studies in literature. The incidence was 1%. There was no increase in complications of pregnancy though there was an increased caesarean section rate and perinatal mortality rate. It is imperative that all mature pregnant women are managed as a high risk group but we should be mindful of the need to justify intervention in the same way as in the younger age group.

Myocardial wall thickening from gated Magnetic Resonance images using Laplace's equation

The aim of our work is to present a robust 3D automated method for measuring regional myocardial thickening using cardiac magnetic resonance imaging (MRI) based on Laplace's equation. Multiple slices of the myocardium in short-axis orientation at end-diastolic and end-systolic phases were considered for this analysis. Automatically assigned 3D epicardial and endocardial boundaries were fitted to short-axis and long axis slices corrected for breathold related misregistration, and final boundaries were edited by a cardiologist if required. Myocardial thickness was quantified at the two cardiac phases by computing the distances between the myocardial boundaries over the entire volume using Laplace's equation. The distance between the surfaces was found by computing normalized gradients that form a vector field. The vector fields represent tangent vectors along field lines connecting both boundaries. 3D thickening measurements were transformed into polar map representation and 17-segment model (American Heart Association) regional thickening values were derived. The thickening results were then compared with standard 17-segment 6-point visual scoring of wall motion/wall thickening (0=normal; 5=greatest abnormality) performed by a consensus of two experienced imaging cardiologists. Preliminary results on eight subjects indicated a strong negative correlation (r=-0.8, p<0.0001) between the average thickening obtained using Laplace and the summed segmental visual scores. Additionally, quantitative ejection fraction measurements also correlated well with average thickening scores (r=0.72, p<0.0001). For segmental analysis, we obtained an overall correlation of -0.55 (p<0.0001) with higher agreement along the mid and apical regions (r=-0.6). In conclusion 3D Laplace transform can be used to quantify myocardial thickening in 3D.

EST-derived single nucleotide polymorphism markers for assembling genetic and physical maps of the barley genome

In a panel of seven genotypes, 437 expressed sequence tag (EST)-derived DNA fragments were sequenced. Single nucleotide polymorphisms (SNPs) that were polymorphic between the parents of three mapping populations were mapped by heteroduplex analysis and a genome-wide consensus map comprising 216 EST-derived SNPs and 4 InDel (insertion/deletion) markers was constructed. The average frequency of SNPs amounted to 1/130 bp and 1/107.8 bp for a set of randomly selected and a set of mapped ESTs, respectively. The calculated nucleotide diversities (pi) ranged from 0 to 40.0 x 10(-3) (average 3.1 x 10(-3)) and 0.52 x 10(-3) to 39.51 x 10(-3) (average 4.37 x 10(-3)) for random and mapped ESTs, respectively. The polymorphism information content value for mapped SNPs ranged from 0.24 to 0.50 with an average of 0.34. As expected, combination of SNPs present in an amplicon (haplotype) exhibited a higher information content ranging from 0.24 to 0.85 with an average of 0.50. Cleaved amplified polymorphic sequence assays (including InDels) were designed for a total of 87 (39.5%) SNP markers. The high abundance of SNPs in the barley genome provides avenues for the systematic development of saturated genetic maps and their integration with physical maps.

Genetic mapping and BAC assignment of EST-derived SSR markers shows non-uniform distribution of genes in the barley genome

A set of 111,090 barley expressed sequence tags (ESTs) was searched for the presence of microsatellite motifs [simple sequence repeat (SSRs)] and yielded 2,823 non-redundant SSR-containing ESTs (SSR-ESTs). From this, a set of 754 primer pairs was designed of which 525 primer pairs yielded an amplicon and as a result, 185 EST-derived microsatellite loci (EST-SSRs) were placed onto a genetic map of barley. The markers show a uniform distribution along all seven linkage groups ranging from 21 (7H) to 35 (3H) markers. Polymorphism information content values ranged from of 0.24 to 0.78 (average 0.48). To further investigate the physical distribution of the EST-SSRs in the barley genome, a bacterial artificial chromosomes (BAC) library was screened. Out of 129 markers tested, BAC addresses were obtained for 127 EST-SSR markers. Twenty-seven BACs, forming eight contigs, were hit by two or three EST-SSRs each. This unexpectedly high incidence of EST-SSRs physically linked at the sub-megabase level provides additional evidence of an uneven distribution of genes and the segmentation of the barley genome in gene-rich and gene-poor regions.

Chromosome 6p amplification and cancer progression

Chromosomal imbalances represent an important mechanism in cancer progression. A clear association between DNA copy-number aberrations and prognosis has been found in a variety of tumours. Comparative genomic hybridisation studies have detected copy-number increases affecting chromosome 6p in several types of cancer. A systematic analysis of large tumour cohorts is required to identify genomic imbalances of 6p that correlate with a distinct clinical feature of disease progression. Recent findings suggest that a central part of the short arm of chromosome 6p harbours one or more oncogenes directly involved in tumour progression. Gains at 6p have been associated with advanced or metastatic disease, poor prognosis, venous invasion in bladder, colorectal, ovarian and hepatocellular carcinomas. Copy number gains of 6p DNA have been described in a series of patients who presented initially with follicle centre lymphoma, which subsequently transformed to diffuse large B cell lymphoma. Melanoma cytogenetics has consistently identified aberrations of chromosome 6, and a correlation with lower overall survival has been described. Most of the changes observed in tumours to date map to the 6p21-p23 region, which encompasses approximately half of the genes on all of chromosome 6 and one third of the number of CpG islands in this chromosome. Analyses of the genes that cluster to the commonly amplified regions of chromosome 6p have helped to identify a small number of molecular pathways that become deregulated during tumour progression in diverse tumour types. Such pathways offer promise for new treatments in the future.

Detection of novel variant TMPRSS2 /ERG fusion transcripts suggests independent genomic alterations may underlie origin of multi-centric prostate cancer

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Background: Most of the early successes in identifying chromosomal translocations in neoplasias came from the study of hematological malignancies and sarcomas, with limited evidence that consistent genomic rearrangements were present in epithelial malignancies. Recently it was reported that ∼75% of prostate cancers carry a genomic rearrangement leading to fusion of the TMPRSS2 locus to either the ERG or ETV1 genes (both ETS transcription factors). In the fusion gene, the androgen-sensitive promoter elements of TMPRSS2 are thought to mediate over-expression of these ETS transcription factors. Over-activity of the ETS family of transcription factors has been suggested to be involved in the transition from pre-neoplasia to carcinoma as they regulate genes involved in processes such as adhesion, motility, invasion and angiogenesis. Methods: Using both RT-PCR and FISH with published primers and BACs respectively we analyzed 15 samples of prostatic carcinoma from radical prostatectomies and sequenced a subset of the TMPRSS2/ERG fusions. Results: We have found ERG-TMPRSS2 fusion transcripts in 6 samples and no ETV1-TMPRSS2 fusions. Of the 6 fusion tumours, 5 were Gleason 7 and 1 was Gleason 9. Tumour stages ranged from T2a-T3b. One sample with multi-centric carcinoma exhibited 2 distinct in-frame rearrangements generating novel TMPRSS2 /ERG fusion transcripts. Variant I TMPRSS2/ERG transcript was 430 bp and it led to fusion of exons 1 and 2 of the TMPRSS2 gene with exons 5 and 6 of the ERG gene. Variant II TMPRSS2/ERG fusion transcript was slightly smaller at 350 bp and it led to fusion of exon 1 of the TMPRSS2 gene to exons 5 and 6 of the ERG gene. These novel transcripts appear to be smaller than the published fusion proteins but preliminary analysis suggests that all known regulatory and functional protein domains are maintained. Conclusions: The demonstration of two new TMPRSS2/ERG variant fusion transcripts in prostate cancer deserves further study to evaluate their functional impact and prognostic and pathological importance. Moreover the presence of two distinct transcripts within a single multi-centric tumor provides genomic evidence that independent clonal neoplasms can arise synchronously in prostate cancer.

No significant financial relationships to disclose.