Myh deficiency enhances intestinal tumorigenesis in multiple intestinal neoplasia (ApcMin/+) mice.

Monoallelic APC and biallelic MYH (homolog of Escherichia coli mutY) germ-line mutations are independently associated with a strong predisposition to colorectal adenomas and carcinoma in humans. Whereas mice heterozygous for mutant Apc develop intestinal tumors, mice homozygous for mutant Myh do not show increased tumor susceptibility. We analyzed the phenotype of Apc(Min/+)/Myh(-/-) mice and found that they developed significantly more adenomas in the small intestine than did Apc(Min/+)/Myh(+/+) or Apc(Min/+)/Myh(+/-) mice (median 231 versus 151 versus 152). In the large bowel, Apc(Min/+)/Myh(-/-) mice showed significant increases in the number of aberrant crypt foci. In addition, Apc(Min/+)/Myh(-/-) mice developed an increased number of mammary tumors. Molecular analyses suggested that at least 19% of intestinal tumors from Apc(Min/+)/Myh(-/-) mice had acquired intragenic Apc mutations rather than allelic loss. Consistent with a defect in base excision repair, three intragenic Apc mutations in polyps without allelic loss from Apc(Min/+)/Myh(-/-) mice were shown to be G:C to T:A transversions which resulted in termination codons; no such mutations were found in polyps from Apc(Min/+)/Myh(+/+) or Apc(Min/+)/Myh(+/-) mice. Tumors from Apc(Min/+)/Myh(+/-) mice harbored neither somatic mutations nor allelic loss at Myh. Thus, homozygous, but not heterozygous, Myh deficiency enhanced intestinal tumorigenesis in Apc(Min/+) mice. The excess small-bowel adenomas in Apc(Min/+)/Myh(-/-) mice, therefore, appear to be a model of MYH-associated polyposis in humans.

The Effect of 'On-Line' POCT on Patient waiting times in an Accident and Emergency Department.

This POCT (point of care testing) team was constructed at the start of 2012 to implement the POCT project aiming to define and test the hypothesis that interfacing POCT devices to a clinical electronic order communications system reduces patient waiting times in an NHS Accident and Emergency Department (A&E). The devices selected for evaluation initially comprised the Sysmex XS 1000i haematology analyser and the Abbott i-Stat chemistry analyser. The POCT devices were interfaced to a server (Midlynx) which in turn was connected via the hospital internal network, to the ICE system (Integrated Clinical Environment). Test orders entered on the ICE system produced a bar code label read by the individual POCT devices. Once required tests were assayed, the results were transmitted back to the ICE system, where they could be viewed by users across the hospital site. The quality of POCT analytical performance was assessed by running quality control checks as recommended by the manufacturers and by exchanging samples daily with the clinical laboratory. The I-Stat (a Chemistry analyser manufactured by 'Abbott plc') was also tested against material obtained from a national external quality assurance scheme (NEQAS). The time taken to produce POCT tests was calculated as the time elapsed (TE) between requesting tests, and the time at which completed results were returned to the ICE system. Patient waiting times were derived from the patient administration system (Symphony) used in the A&E department. To assess the true effect of POCT on patient waiting times the analysis was confined to cases associated with POCT tests only (n = 217). A control population (n=229) was randomly selected from the clinical laboratory database. The time interval between requesting a test and receiving the results for the POCT tests was 23 minutes and for the laboratory tests, 60 minutes. The patient waiting times (time of discharge - time of arrival) was 167 minutes for the POCT group and 208 for the clinical laboratory group, a difference of 31 minutes. The project confirmed that interfaced (on-line) POCT has many advantages with respect to the quality and safety of data management. The benefits include reliable identification of the requesting clinician and patient and the assurance that the right result is allocated to the right patient. The study also showed that the quality of results produced by the POCT devices met the requirements of the clinical environment.