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Biomedical subjects

E O'Regan

Publications and source records attributed to E O'Regan.

8 recordsLinked to original sources
PubMed2006

Serum levels of insulin-like growth factors (IGFs) and their binding proteins (IGFBPs), -1, -2, -3, in oral cancer.

INTRODUCTION: Insulin-like growth factor (IGF) possesses mitogenic properties promoting cellular proliferation and inhibiting cellular apoptosis. Reported evidence suggests that cancer (non-oral) is associated with high circulating levels of IGF-1 and low levels of IGFBP-3. AIMS: This study measured circulating levels of IFG-1 and IGFBPs -1, -2 and -3 in oral cancer patients. METHODOLOGY: Blood was collected from surgical patients and controls. Samples were assayed for IGF-1 and IGFBPs -1, -2, -3, using commercially available enzyme-linked immunosorbant assays (ELISA; R&D Systems Europe, Oxon, UK). RESULTS: Twenty-seven oral cancer and 31 age- and sex-matched patients were recruited. Mean IGF-1 and IGFBP-3 levels were significantly lower in cancer patients than controls (85.3 ng/ml and 2008 ng/ml versus 191 ng/ml and 2935 ng/ml, P<0.001). In contrast, levels of IGFBPs 1 and 2 were significantly higher in cancer patients than in controls. No significant association was demonstrated with tumour size or nodal metastases. DISCUSSION: This study has shown that in contrast to other cancers, circulating levels of IGF-1 and IGFBP-3 may both be lowered in patients with head and neck cancer.

Biomarkers, Tumor↗
PubMed2005

Histological evidence for lichen planus in clinically normal perilesional tissue.

The objective of this study was to examine the histological features of apparently normal oral mucous membrane adjacent to lesions of oral lichen planus. Twenty-six patients attending an oral medicine unit with clinical lesions typical of oral lichen planus had biopsies of lesional and perilesional sites. Biopsies were examined for histopathological features of oral lichen planus. Twenty-two (85%) of lesional biopsies and 12 (46%) of the perilesional biopsies were reported as either typical or showing some features of lichen planus. Twelve of these 22 cases (55%) had both lesional and perilesional biopsies reported as either typical or showing some features of lichen planus. These 12 cases represented 46% of all cases. In four cases (15%) neither the lesional nor the adjacent perilesional biopsy was reported as lichen planus. The inflammatory process in oral lichen planus may extend beyond the confines of the clinical lesion into adjacent mucous membrane of normal appearance.

Adult↗
PubMed2005

ret/PTC and BRAF act as distinct molecular, time-dependant triggers in a sporadic Irish cohort of papillary thyroid carcinoma.

The purpose of this study was to assess BRAF mutation rates in various thyroid tissues and to investigate if concomitant mutations with ret/PTC activation occurred in inflammatory and neoplastic lesions. To this end, we developed a novel Taqman based screening assay for the common T1799A BRAF mutation. Heterozygous T1799A mutations were detected in 13 of 34 (44%) papillary thyroid carcinomas (PTCs) tested. No such mutations were detected in the other tissue types tested. Concomitant presence of both oncogenes was reported in 5 of the 34 PTCs. A significant temporal trend was observed, with ret/PTC chimera detected for the most part before 1997 and BRAF mutations being more prevalent after 1997. The results suggest that some environmental/etiological agent(s) may have influenced the pathobiology of thyroid tumor development, among the population examined, over time.

Adult↗
PubMed2004

Necrotizing sialometaplasia: an unusual bilateral presentation associated with antecedent anaesthesia and lack of response to intralesional steroids. Case report and review of the literature.

Necrotizing sialometaplasia is a self-limiting, variably ulcerated benign process affecting minor salivary glands. Accurate histological diagnosis is paramount, as it has been mistaken for malignancy, which has resulted in excessively aggressive and unnecessary radical surgery. A unique case of bilateral necrotizing sialometaplasia, presenting with anaesthesia of the greater palatine nerves, is described. An attempt at active therapy with intralesional steroids had no effect on the course of the condition.

Adult↗
PubMed2004

Hyalinizing clear cell carcinoma of salivary gland: an aggressive variant.

Although hyalinizing clear cell carcinoma (HCCC) had been previously illustrated by several authors, it was not until 1994 that this tumour was characterized by Milchgrub et al. [Am J Surg Pathol (1994),18,74] and separated from the heterogeneous group of clear cell carcinomas described in the literature. HCCC is a distinctive infiltrative low-grade, monomorphic, glycogen-rich clear cell carcinoma with prominent stromal hyalinization occurring most often in the minor salivary glands of adult women. A case of hyalinizing clear cell carcinoma arising in the tongue of an adult female is described with special reference to the presence of minor foci of mitotic activity, necrosis and anaplasia in this otherwise typical low-grade carcinoma. Widespread metastases and death within a year of initial presentation in this case suggests that there may be a subset of this indolent tumour in which these features are associated with a poor prognosis.

Adenocarcinoma, Clear Cell↗
PubMed1997

Selective recognition of a cisplatin-DNA adduct by human mismatch repair proteins.

The antitumor agent cis-diamminedichloroplatinum(II) (cisplatin) introduces cytotoxic DNA damage predominantly in the form of intrastrand crosslinks between adjacent purines. Binding assays using a series of duplex oligonucleotides containing a single 1,2 diguanyl intrastrand crosslink indicate that human cell extracts contain factors that preferentially recognise this type of damage when the complementary strand contains T opposite the 3', and C opposite the 5'guanine in the crosslink. Under the conditions of the band-shift assay used, little binding is observed if the positions of the T and C are reversed in the complementary strand. Similarly, duplexes containing CC or TT opposite the crosslink are recognised relatively poorly. The binding activity is absent from extracts of the colorectal carcinoma cell lines LoVo and DLD-1 in which the hMutSalpha mismatch recognition complex is inactivated by mutation. Extensively purified human hMutSalpha exhibits the same substrate preference and binds to the mismatched platinated DNA at least as well as to an identical unplatinated duplex containing a single G.T mismatch. It is likely, therefore, that human mismatch repair may be triggered by 1,2 diguanyl intrastrand crosslinks that have undergone replicative bypass.

Adenosine Triphosphatases↗