Showing papers by "Joanne E. Martin published in 2004"

Deranged smooth muscle alpha-actin as a biomarker of intestinal pseudo-obstruction: a controlled multinational case series.

Abstract: Background and aims: Chronic idiopathic intestinal pseudo-obstruction (CIIP) is a severe motility disorder associated with significant morbidity. Several histopathological (neuropathic and myopathic) phenotypes have been described but only a single adult with jejunal smooth (circular) muscle α-actin deficiency. We present a prospective multinational case series investigating smooth muscle α-actin deficiency as a biomarker of this disease. Methods: A total of 115 fully clinically and physiologically (including prolonged (24 hour) ambulatory jejunal manometry) characterised CIIP patients from three European centres were studied. Immunohistochemical localisation of actins and other cytoskeletal proteins were performed on laparoscopic full thickness jejunal biopsies and compared with adult controls. Distribution of α-actin was also characterised in other gut regions and in the developing human alimentary tract. Results: Twenty eight of 115 (24%) CIIP patient biopsies had absent (n = 22) or partial (n = 6) jejunal smooth muscle α-actin immunostaining in the circular muscle layer. In contrast, smooth muscle α-actin staining was preserved in the longitudinal muscle and in adult jejunal controls (n = 20). Comparative study of other adult alimentary tract regions and fetal small intestine, suggested significant spatial and temporal variations in smooth muscle α-actin expression. Conclusions: The ability to modulate α-smooth muscle actin expression, evident in development, is maintained in adult life and may be influenced by disease, rendering it a valuable biomarker even in the absence of other structural abnormalities.

Prediction of progression in pTa and pT1 bladder carcinomas with p53, p16 and pRb

Abstract: Currently available prognostic tools appear unable to adequately predict recurrence and progression in non muscle-invasive bladder carcinomas. We aimed to assess the prognostic value of immunohistochemical evaluation of the cell cycle markers p53, p16 and pRb. Paraffin blocks were obtained from 78 cases of pTa and pT1 transitional cell carcinomas, for which long-term follow-up was available. Representative sections were stained using antibodies against p53, p16 and pRb. Altered marker expression was found in 45, 17 and 30% of cases, respectively. Concurrent alteration of two or three markers occurred in 19% of cases, and was significantly associated with grade and stage. In univariate survival analysis, the concurrent alteration of any two markers was significantly associated with progression. The greatest risk was produced by alteration of both p53 and p16, which increased the risk of progression by 14.45 times (95% confidence interval (CI) 3.10-67.35). After adjusting for grade and stage, this risk was 7.73 (CI 1.13-52.70). The markers did not generally predict tumour recurrence, except in the 25 pT1 tumours. In these, p16 alteration was associated with a univariate risk of 2.83 (CI 1.01-7.91), and concurrent p53 and p16 alteration with a risk of 9.29 (CI 1.24-69.50). Overall, we conclude that the immunohistochemical evaluation of p53 and p16 may have independent prognostic value for disease progression, and may help guide management decisions in these tumours.

Towards a mutant map of the mouse – new models of neurological, behavioural, deafness, bone, renal and blood disorders

Abstract: With the completion of the first draft of the human genome sequence, the next major challenge is assigning function to genes. One approach is genome-wide random chemical mutagenesis, followed by screening for mutant phenotypes of interest and subsequent mapping and identification of the mutated genes in question. We (a consortium made up of GlaxoSmithKline, the MRC Mammalian Genetics Unit and Mouse Genome Centre, Harwell, Imperial College, London, and the Royal London Hospital) have used ENU mutagenesis in the mouse for the rapid generation of novel mutant phenotypes for use as animal models of human disease and for gene function assignment (Nolan et al., 2000). As of 2003, 35,000 mice have been produced to date in a genome-wide screen for dominant mutations and screened using a variety of screening protocols. Nearly 200 mutants have been confirmed as heritable and added to the mouse mutant catalogue and, overall, we can extrapolate that we have recovered over 700 mutants from the screening programme. For further information on the project and details of the data, see http://www.mgu.har.mrc.ac.uk/mutabase.

The annexin 1-/- mouse: phenotypic studies

Abstract: We investigated the phenotype of Anx-A1-/- mice and studied the appearance of the gene expression during embryonic and postnatal development. Anx-A1-/- mice are fertile and there were no apparent differences in litter sizes or other breeding statistics when compared to litter mate Anx-A1+/+ controls. The null mice grew at the same rate as the Anx-A1+/+ controls and appeared normal at all ages. Plasma sodium, potassium and possibly calcium were slightly elevated in an apparently genotype-dependent fashion, although all these differences were probably still within the normal range. The liver enzyme ALT was significantly elevated in the Anx-A1-/- mice but most other aspects of blood chemistry were no different. In terms of post mortem pathology, there were few exceptional findings although genotype related changes were seen in the weight of the liver, heart, thymus, pancreas, pituitary gland and kidney at necroscopy. Examination by western blotting of the tissue concentrations of other members of the annexin family revealed that Anx-A1 gene deletion lead, in some organs (e.g. lung and thymus), to changes in the tissue concentration of other annexins as well as the pro-inflammatory enzymes COX-2, cPLA2 and iNOS. There was some evidence of a sexual dimorphism in this effect. Anx-A1 gene expression was first detected at embryonic day 10.5 in the corneal epithelium. Thereafter, the skin, bone and respiratory tract were among several sites that displayed strong gene expression during embryonic development whereas the brain and the heart exhibited little gene expression at any developmental stage. These findings are discussed in relation to several proposed roles for the protein.

Blood cells with fetal haemoglobin (F-cells) detected by immunohistochemistry as indicators of solid tumours

Abstract: Fetal haemoglobin (HbF) is the main haemoglobin of the late fetus and the newborn, constituting around 80% of the total haemoglobin1 In normal adults, HbF comprises less than 1% of the total haemoglobin2–4 However, increased concentrations of HbF are common in some haemoglobinopathies,5 in addition to many neoplasms, including those studied here, namely: germ cell tumour (GCT),6,7 trophoblastic disease (TD),7,8 lymphoma,9,10 multiple myeloma (MM),10–12 myelodysplastic syndrome (MDS),12–14 and ovarian adenocarcinoma (OA)7,12 “Some early studies claimed that fetal haemoglobin is produced by the tumour cells of germ cells tumours, rather than by the red blood cells residing in the tumour” Recently we were able to distinguish between whole blood HbF and plasma HbF as two independent indicators of cancer7,12 The origin of the whole blood HbF is the circulating red blood cell (RBC) As such, whole blood HbF is not an oncofetal protein, produced by tumour cells, but an inducible protein in many neoplasms In contrast, the origin of plasma HbF was not clear, especially with regard to non-haematological solid tumours For instance, among 23 cases of testicular germ cell tumour,7 14 had raised plasma HbF, most of them with normal whole blood HbF Similarly, in persistent trophoblastic diseases, raised plasma HbF was very common12 Some early studies6,15 claimed that HbF is produced by the tumour cells of germ cells tumours, rather than by the RBC residing in the tumour In our preliminary immunohistochemical study,7 we found faint staining of tumour cells using haemoglobin A absorbed anti-HbF antibody However, it was still unclear whether plasma HbF is a classic oncofetal protein, produced by tumour cells, or a component of haemopoietic cells or RBC, concentrated inside the tissue of certain tumours In our attempt to solve this problem, and to re-evaluate our preliminary observations,7 we prepared a new batch of immunoaffinity purified anti-HbF antibody, and the results obtained using this reagent are presented here