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Biomedical subjects

Chris Dawson

Publications and source records attributed to Chris Dawson.

6 recordsLinked to original sources
PubMed2006

Pneumopericardium: a rare complication of laparoscopic varicocoele ligation.

Although symptomatic pneumopericardium post-laparoscopic varicocoele ligation procedure is rare, numerous cases have been reported and identified pneumopericardium as a complication of laparoscopic surgery. Pneumopericardium after other urological procedures has been previously reported when diagnosed incidentally on chest X-ray but there are no reports of symptomatic presentation. We hereby present the first symptomatic pneumopericardium case after a routine procedure for the ligation of varicocoele.

Adult↗
PubMed2004

Expression of tumor necrosis factor receptor-associated factor 1 in nasopharyngeal carcinoma: possible upregulation by Epstein-Barr virus latent membrane protein 1.

EBV infection is associated with virtually all cases of undifferentiated NPC, and the EBV-encoded LMP1 is expressed in a proportion of cases. LMP1 has transforming functions similar to members of the TNF receptor family and activates intracellular signaling cascades through interaction with TRAFs. In B cells, expression of TRAF1 is in turn upregulated by LMP1. LMP1 signaling in epithelial cells may be affected by the presence or absence of TRAF1. By immunohistochemistry, we detected TRAF1 expression in 17 of 42 (40%) EBV+ undifferentiated NPCs. All 7 LMP1+ NPC biopsies were also TRAF1+. Using an RNAse protection assay, high-level TRAF1 expression was detected in an LMP1-expressing NPC-derived cell line (C15) and expression was weaker in 2 LMP1- cell lines (C17, C19). Finally, LMP1 upregulated TRAF1 expression in an EBV- keratinocyte cell line. Our results demonstrate that TRAF1 is expressed in NPC tumor cells in vivo and suggest that TRAF1 expression may be upregulated by LMP1 in NPC. An antiapoptotic function has been proposed for TRAF1, and this may be relevant for the pathogenesis of NPC.

Antigens, Viral↗
PubMed2002

Tumour necrosis factor-alpha in Barrett's oesophagus: a potential novel mechanism of action.

Barrett's metaplasia (BM) is an early lesion in the progression from oesophageal inflammation through dysplasia to the development of Barrett's adenocarcinoma (BA). Previous work indicates that BM and BA are associated with reduced E-cadherin expression and increased cytoplasmic/nuclear pools of its associated protein beta-catenin. beta-catenin participates in Wnt signalling and activates oncogene transcription by complexing with T-cells factors (TCF). One such oncogene is c-myc. We have previously shown that TNF-alpha can down-regulate E-cadherin expression. Here, we assess TNF-alpha expression in Barrett's metaplasia and examine if TNF-alpha can promote beta-catenin mediated transcription of oncogenes in a gastrointestinal model system. Employing immunohistochemistry and Western blot analysis of oesophageal tissue, epithelial expression of TNF-alpha increases with progression along the metaplasia-dysplasia-carcinoma sequence (P<0.001). beta-catenin mediated transcription was then assessed in TNF-alpha stimulated cell lines using the TOPFLASH reporter system whilst c-myc expression was assessed by real time PCR. In a columnar intestinal cell model, TNF-alpha induces c-myc expression which is induced via beta-catenin mediated transcription (P<0.05). This beta-catenin mediated transcription is independent of NF-kappaB activation. Thus, TNF-alpha is up-regulated in the progression of Barrett's oesophagus and beta-catenin mediated transcription of c-myc is a novel pathway whereby elevated levels of TNF-alpha may lead to oncogene transcription and altered biology in gastrointestinal epithelia and metaplasia.

Adenocarcinoma↗
PubMed2002

Testicular cancer: seek advice early.

Men's partners are often the first to notice a common sign of testicular cancer -- painless swelling or abnormality of the testis or scrotum. The man should consult his GP straightaway, as early diagnosis is critical.

Adult↗