Detection of Ki-ras mutations in tissue and plasma samples of patients with pancreatic cancer using PNA-mediated PCR clamping and hybridisation probes

In the present study, we combined the PCR-clamping approach with melting curve analysis using mutant specific hybridisation probes and wild-type specific peptide nucleic acids (PNAs) to determine the genotypes of the most frequent point mutation in codon 12 of the proto-oncogene Ki-ras in tissue and plasma samples of patients with pancreatic cancer. The sensitivity of our assay was 1–5 × 10−5. The melting curve analysis of tissue samples of four patients revealed two valine mutations, one none-valine mutation and one wild-type sequence. Ki-ras alterations were found in 28% of DNAs (18 out of 64) of nonrelated plasma samples of 10 patients with ductal adenocarcinoma of the pancreas. The valine mutation was the predominantly detected gene alteration (83%). Out of ten patients investigated, four patients (40%) became positive during clinical observation with respect to Ki-ras mutation. All four patients exhibited progressive disease and high levels of tumour marker CA 19-9. In conclusion, the one-step procedure discribed may be a useful clinical tool for analysing Ki-ras point mutations in tissue and plasmas samples. In addition, this method can be adapted for simultanous detection of multiple mutations and quantitation

The effect of temperature on non-specific defence parameters of three strains of juvenile Atlantic halibut (Hippoglossus hippoglossus L.)

The effect of temperature (8, 12, 15 and 18° C) on a variety of non-specific defence and haematological parameters was examined in three geographically distinct reared strains (Canadian, Icelandic, Norwegian) of Atlantic halibut. The results indicate that temperature exerts a considerable influence on some blood parameters (packed cell volume and the percentage population of leucocytes in peripheral blood) and on some humoral parameters (serum lysozyme activity and serum protein levels) of halibut. A high temperature of 18° C caused a decrease in the number of circulating blood cells and an increase in serum lysozyme levels; effects consistent with those reported within the literature for stress. The different strains of halibut exhibited differing responses with respect to differential counts of peripheral blood lymphocytes and thrombocytes, and to serum protein concentrations, serum lysozyme activity, serum iron content, unsaturated iron binding capacity of serum and O-2 production by kidney macrophages

Susceptibility of three different strains of juvenile Atlantic halibut (Hippoglossus hippoglossus L.) cultured at two different temperatures to Vibrio anguillarum and temperature effect on antibody response

Three geographically distinct-reared strains (Canadian, Icelandic, Norwegian) of juvenile Atlantic halibut (Hippoglossus hippoglossus L.) cultured at optimal and super-optimal growth temperatures (12 and 18° C respectively), were challenged with a virulent isolate of Vibrio anguillarum by injection. The halibut were injected intraperitoneally with 100 μl of the bacterial suspension (1×106 cells per fish). After challenge, temperature and strain-related differences in survival were observed. Canadian and Icelandic halibut cultured at the super-optimal temperature of 18° C were significantly more susceptible to infection than those strains cultured at 12° C. Total mortality at 18° C for the Canadian and Icelandic strains was 56·4 and 61·85% respectively, compared to 32 and 26·6% respectively at 12° C. Norwegian halibut were significantly more resistant to infection with V. anguillarum at 18° C compared to the other strains, with total mortality of 13·3%. There was no significant difference in total mortality of Norwegian halibut at 18 or 12° C (13·3, 25% respectively). The specificity of the antibodies in sera from challenged halibut cultured at 18° C was primarily to LPS. Immunoblots showed the presence of antibodies against O-side chain antigens. This reaction was strongest in sera from the Norwegian halibut strain compared with the Canadian and Icelandic halibut, which suggests that the difference in resistance to challenge may be ascribable to the presence of antibodies to LPS. Specific antibody levels, as measured by ELISA, increased with increasing temperature and strain differences were apparent, however these did not relate to disease resistance

The interrelation of growth and disease resistance of different populations of juvenile Atlantic halibut (Hippoglossus hippoglossus L.)

Growth of juvenile Atlantic halibut from three areas of the North Atlantic (Canada, Iceland and Norway) was studied in an experiment using individual tagged fish reared at 15°C for 85 days. Fish from each population were subsequently split into two groups and acclimatised to either 12°C or 18°C. The fish were then injected intra-peritoneally with a Vibrio anguillarum bacteria suspension and mortality monitored for 4 weeks. Growth rates of the Canadian population ranked lowest, whereas the Norwegian population had the highest mean growth rates (SGR=1.70% day-1, 1.62% day-1 and 1.53% day-1 for the Norwegian, Icelandic and Canadian populations, respectively). The halibut from Norway had the best survival following bacterial challenge (80%, 50% and 55% survival for the Norwegian, Icelandic and Canadian populations, respectively). Mortality was higher at 18°C than at 12°C in the Icelandic (62% at 12°C and 27% at 18°C) and Canadian (56% at 12°C and 32% at 18°C) fish, whereas a smaller difference between temperatures was observed in the Norwegian fish (25% at 12°C and 13% at 18°C). Fish that survived the challenge test were those that had grown fastest in the growth trial. Low, but significant, correlations between survival and size and growth were seen, but these correlations varied between populations. In the Canadian population, no correlation between size and growth and survival were seen; only size was correlated (r=0.27) with survival in the Icelandic population, whereas both size (r=0.18) and growth (r=0.17) were correlated with survival in the Norwegian population

Implementation of BSG/ACPGBI/PHE polypectomy surveillance guidelines safely reduces the burden of surveillance in a screening cohort: a virtual model study

Objective To evaluate the impact of British Society of Gastroenterology/Association of Coloproctology of Great Britain and Ireland/Public Health England (BSG/ACPGBI/PHE) 2019 polypectomy surveillance guidelines within a national faecal immunochemical test-based bowel cancer screening (BS) cohort on surveillance activity and detection of pathology by retrospective virtual application.Design A retrospective review of BS colonoscopies performed in 2015–2016 with 5 years prospective follow-up in single institution. Index colonoscopies were selected. Incomplete colonoscopies were excluded. Histology of all resected polyps was reviewed. Surveillance intervals were calculated according to BSG/ACPGBI/PHE 2019 guidelines and compared with pre-existing ‘European Guidelines for Quality Assurance in Colorectal Cancer Screening and Diagnosis’ (EUQA 2013). Total number of colonoscopies deferred by virtual implementation of BSG/ACPGBI/PHE 2019 guidelines were calculated. Pathology identified on procedures that would have been deferred was reviewed.Results Total number of index BS colonoscopies performed in 2015–2016 inclusive was 890. 115 were excluded (22 no caecal intubation, 51 inadequate bowel preparation, 56 incomplete polyp clearance). N=509 colonoscopies were scheduled within a 5-year interval following index colonoscopy surveillance rounds based on EUQA guidelines. Overall, volume of surveillance was significantly reduced with retrospective application of BSG/ACPGBI/PHE 2019 guidelines (n=221, p<0.0001). No cancers were detected within the ‘potentially deferred’ procedures who attended for follow-up (n=330) with high-risk findings found in<10% (n=30) of colonoscopies within the BSG/ACPGBI/PHE cohort.Conclusion BSG/ACPGBI/PHE 2019 guidelines safely reduce the burden of colonoscopy demand with acceptable pathology findings on deferred colonoscopies