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Whatman No. 1 chromatography paper is widely used as a substrate for cellulose-based immunoassays. The immobilized proteins are used to capture target biomarkers for detection. However, alternative paper substrates may facilitate mass production of immunoassays as diagnostic tests. Here, we assessed the physical characteristics and protein immobilization capabilities of different commercial papers. Some substrates fulfilled our design criteria, including adequate flow rate and sufficient protein immobilization for efficient target capture. This study demonstrates that a variety of paper substrates can be bioactivated and used to capture target biomarkers, enabling development of affordable diagnostic tests from a range of starting materials.

Visualizing and quantifying molecular motion and interactions inside living cells provides crucial insight into the mechanisms underlying cell function. This has been achieved by super-resolution localization microscopy and single-molecule tracking in conjunction with photoactivatable fluorescent proteins. An alternative labelling approach relies on genetically-encoded protein tags with cell-permeable fluorescent ligands which are brighter and less prone to photobleaching than fluorescent proteins but require a laborious labelling process. Either labelling method is associated with significant advantages and disadvantages that should be taken into consideration depending on the microscopy experiment planned. Here, we describe an optimised procedure for labelling Halo-tagged proteins in liveEscherichia colicells. We provide a side-by-side comparison of Halo tag with different fluorescent ligands against the popular photoactivatable fluorescent protein PAmCherry. Using test proteins with different intracellular dynamics, we evaluated fluorescence intensity, background, photostability, and single-molecule localization and tracking results. Capitalising on the brightness and extended spectral range of fluorescent Halo ligands, we also demonstrate high-speed and dual-colour single-molecule tracking.

Background: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited vascular dementia characterised by recurrent ischemic strokes in the deep white matter. Mutations in the gene encoding the cell surface receptor, Notch3, have been identified in CADASIL patients, and accumulation of the extracellular domain of Notch3 has been demonstrated in affected vessels. Almost all CADASIL mutations alter the number of cysteine residues in the epidermal growth factor (EGF)-like repeats in the extracellular domain of the protein. Objectives: To understand the functional consequences of a recurrent CADASIL mutation on furin processing, cell surface expression, ligand binding, and activation of a downstream effector CBF1 by the Notch3 receptor. Methods: We expressed wild type and mutant Notch3 receptors in cultured cells and examined cell surface expression of the proteins. We also applied a new flow cytometry based approach to semi-quantitatively measure binding to three Notch ligands. Additionally, we used a well characterised co-culture system to examine ligand dependent activation of transcription from a CBF1-luciferase reporter construct. Results: These studies revealed subtle abnormalities in furin processing of the mutant receptor, although both heterodimeric and full length receptors are present on the cell surface, are capable of interacting with soluble forms of three ligands, Delta1, Delta4, and Jagged1, and retain the ability to activate CBF1 in a ligand dependent manner. Conclusions: By comparison with other mutant forms of Notch3, these data indicate that individual CADASIL mutations can have disparate effects on Notch3 expression and function.

Background: The clinical course of glioblastoma multiforme is characterised by invasive growth and regular recurrence. Many genetic alteration have been identified in the genesis of the disease. However, information about immunohistochemical expression in recurrent lesions is sparse. Objectives: To determine (1) whether the p53/mdm2/EGFR/msh2 expression pattern differs in initial v recurrent glioblastoma multiforme; (2) whether a possible change in expression correlates with prognostic variables (progression-free survival time, total survival time); and (3) whether chemotherapy in addition to surgery and radiotherapy influences the p53/mdm2/EGFR/msh2 expression profile. Methods: 27 patients were studied. They met the following criteria: histologically confirmed diagnosis of glioblastoma multiforme (WHO IV); total tumour resection at initial craniotomy; at least one re-craniotomy for glioblastoma multiforme recurrence; age 21 years or older. All underwent radiotherapy of at least 54 Gy, and 17 received additional chemotherapy. Immunohistochemical staining of initial tumours and recurrences was done with the following monoclonal antibodies: anti-p53 (DO-1), anti-mdm2 (IF-2), anti-EGFR (H11), and anti-msh2 (AB-1). Results: In comparison with the initial tumour, recurrent lesions were characterised by reduced expression of p53 (p < 0.0001) and msh2 (p = 0.0012), while the numbers of mdm2 (p = 0.02), EGFR (p < 0.0001), and msh2 positive specimens (p < 0.0001) were reduced. Chemotherapy was associated with reduced msh2 expression (p < 0.0001). Immunohistochemical variables were not associated with patient survival. Conclusions: There are significant differences in the p53/mdm2/EGFR/msh2 expression patterns in initial v recurrent glioblastoma multiforme. There may be interactions between chemotherapy and changes in the msh2 expression.

Although the role of transforming growth factor beta (TGFbeta) in initiating fibrosis is well established, the role that TGFbeta plays in maintaining fibrosis is unclear. The gene encoding connective tissue growth factor (ccn2; ctgf), which promotes fibrosis, is not normally expressed in dermal fibroblasts unless TGFbeta is present. However, in dermal fibroblasts cultured from lesional areas of scleroderma, ccn2 (ctgf) is expressed constitutively. The contribution of several elements in the ccn2 (ctgf) promoter to basal and TGFbeta induced ccn2 (ctgf) expression in normal and scleroderma fibroblasts has been investigated. A functional SMAD binding site in the ccn2 (ctgf) promoter that is necessary for the TGFbeta mediated induction of this gene has been identified. The previously termed TGFbeta responsive enhancer (TGFbetaRE) in the ccn2 (ctgf) promoter has been found to be necessary for basal promoter activity in normal fibroblasts. The SMAD element is not necessary for the high ccn2 (ctgf) promoter activity seen in scleroderma fibroblasts. However, mutation of the previously termed TGFbetaRE reduces ccn2 (ctgf) promoter activity in scleroderma fibroblasts to that seen in normal fibroblasts. Thus, the maintenance of the scleroderma phenotype, as assessed by a high degree of ccn2 (ctgf) promoter activity, appears to be relatively independent of SMAD action and seems to reflect increased basal promoter activity.

Aims—To study the distribution of Epstein-Barr virus (EBV) variants containing mutations in the latent membrane protein 1 (LMP-1) oncogene and promoter in EBV associated Hodgkin's disease and infectious mononucleosis compared with previous findings in asymptomatic EBV carriers. Methods—Sequence analysis of the EBV LMP-1 promoter and gene in isolates from Danish patients with Hodgkin's disease (n = 61) and infectious mononucleosis (n = 10). Results—Viruses (previously designated group D) that contain two mutations in the activating transcription factor/cAMP response element (ATF/CRE) in the LMP-1 promoter, which are known to decrease promoter activity greatly, were significantly less frequent in Hodgkin's disease than in both infectious mononucleosis (p = 0.0081) and asymptomatic EBV carriers (p = 0.0084). In some cases, the LMP-1 gene contained mutations in a recently identified cytotoxic T cell (CTL) epitope. Most viral isolates contained mutations shown to increase nuclear factor κB (NF-κB) activation and had one of two newly identified C-terminal activation regions 3 (CTAR-3) deleted. The exon 1 Xho-I restriction site in the LMP-1 gene could be lost through a range of different mutations. Conclusions—These findings indicate selection pressure against EBV strains with weak LMP-1 promoter activity in Hodgkin's disease and thus provide further strong circumstantial evidence for the pathogenic role of EBV (and LMP-1) in this disease. Mutation of the CTL epitope suggests immune selection of EBV strains. Many EBV isolates contain functionally important mutations in the LMP-1 gene. Loss of the Xho-I restriction site should not be used as a marker of specific LMP-1 variants.

A novel locus DFNB90 was mapped to 7p22.1-p15.3 by carrying out a genome scan in a multigenerational consanguineous family from Pakistan with autosomal recessive nonsyndromic hearing impairment (ARNSHI).DFNB90 is the eighth ARNSHI locus mapped to chromosome 7. A multipoint LOD score of 4.0 was obtained at a number of SNP marker loci spanning from rs1468996 (chromosome 7: 5.7 Mb) tors957960 (chromosome 7: 18.8 Mb). The 3-unit support interval and the region of homozygosity for DFNB90 spans from markers rs1553960 (chromosome 7: 4.9 Mb) to rs206198 (chromosome 7: 20.3 Mb). Candidate genes ACTB, BZW, OCM, MACC1, NXPH1, PRPS1L1, RAC1 and RPA3, which lie within the DFNB90 region, were sequenced and no potentially causal variants were identified.

Objective To determine and compare the prevalence of MSH6 (a mismatch repair gene) mutations in a cohort of families with Hereditary Non-Polyposis Colorectal Cancer (HNPCC), and in an unselected cohort of endometrial cancer patients (EC). Design Two patient cohorts participated in the study. A cohort of HNPCC families who were known to the Regional Medical Genetics department, and an unselected cohort of patients with a history of EC. All participants received genetic counselling on the implications of molecular testing, and blood was taken for DNA extraction with consent. All samples underwent sequencing and Multiple Ligation probe analysis (MLPA) for mutations in MSH6. Populations DNA from one hundred and forty-three probands from HNPCC families and 125 patients with EC were included in the study. Methods Molecular analysis of DNA in all participants from both cohorts for mutations in MSH6. Outcome measures Prevalence of pathogenic mutations in MSH6. Results A truncating mutation in MSH6 was identified in 3.8% (95% CI 1.0–9.5%) of patients in the endometrial cancer cohort, and 2.6% (95% CI 0.5–7.4%) of patients in the HNPCC cohort. A missense mutation was identified in 2.9% and 4.4% of the same cohorts respectively. No genomic rearrangements in MSH6 were identified. Conclusion MSH6 mutations are more common in EC patients than HNPCC families. Genomic rearrangements do not contribute to a significant proportion of mutations in MSH6, but missense variants are relatively common and their pathogenicity can be uncertain. HNPCC families may be ascertained through an individual presenting with EC, and recognition of these families is important so that appropriate cancer surveillance can be put in place.

Background: Due to their invasive growth, gliomas usually cannot be removed completely and almost always recur as same grade or higher grade malignancies. Objective: To determine whether there were differences in the accumulation of genetic changes between the two types of glioma recurrence. Methods: We genetically characterised 14 cases of lower grade glioma with a same grade recurrence, 12 cases of glioblastoma recurrence, and 14 cases of lower grade glioma with a higher grade recurrence. We investigated LOH (loss of heterozygosity) at 1p36, 10p15, the PTEN region in 10q23, the DMBT1 region in 10q25, 19q13, 22q13, LOH and mutation of TP53, and EGFR amplification. Results: Genetic heterogeneity in the primary tumour was inferred in 3 cases of lower grade glioma with a higher grade recurrence. The cases of lower grade glioma with a higher grade recurrence displayed increased genetic instability in the recurrence (mean of 2.0 additional genetic changes per case) compared to cases with a same lower grade recurrence or those with a glioblastoma recurrence (mean of 0.6 and 0.8 additional changes per case, respectively). Compared to unselected primary glioblastomas, the glioblastomas that recurred as an operable tumour had infrequent EGFR amplification (8% v 30–40% of cases). Conclusions: Gliomas recurring as higher grade lesions might be genetically heterogeneous and accumulate more genetic changes than gliomas recurring as same grade lesions (whether originally low or high grade). Primary glioblastomas from patients for which the recurrence is operated because of prognostically more favourable clinical indices have infrequent EGFR amplification.

Aim—To test the hypothesis that, because the human papillomavirus (HPV) E2 protein represses viral early gene transcription, E2 gene sequence variation or disruption could play a part in the induction of the numerical chromosome abnormalities that have been described in squamous cervical lesions. Methods—The integrity and sequence of the E2 gene from 11 cervical intraepithelial neoplasia (CIN) grade 3 lesions and 14 invasive squamous cell carcinomas, all of which contained HPV-16, were analysed by the polymerase chain reaction (PCR). The E2 gene was amplified in three overlapping fragments and PCR products sequenced directly. Chromosome abnormalities were identified by interphase cytogenetics using chromosome specific probes for chromosomes 1, 3, 11, 17, 18, and X. Results—E2 gene disruption was present in significantly more invasive carcinomas (eight of 14) than CIN 3 lesions (one of 11) (p = 0.03). No association was found between E2 disruption and the presence of a numerical chromosome abnormality. The E2 gene from the non-disrupted isolates was sequenced and wild-type (n = 5) and variant (n = 11) sequences identified. Variant sequences belonged to European and African classes and contained from one to 15 amino acid substitutions. Although numerical chromosome abnormalities were significantly more frequent in invasive squamous cell carcinoma than CIN 3 (p = 0.04), there was no significant relation between the presence of sequence variation and either histological diagnosis or chromosome abnormality. Conclusions—These data do not support the hypothesis that E2 gene disruption or variation is important in the induction of chromosome imbalance in these lesions. However, there is a relation between E2 gene disruption and the presence of invasive disease.