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1.
The high incidence and profile of ras gene mutations reported in spontaneous and chemically induced liver tumours of the B6C3F1 mouse provides a potential means of determining in vivo genotoxicity and its relevance to carcinogenicity. We analysed spontaneous and chemically induced [with 4-amino-biphenyl (ABP), 2-acetylaminofluorene (AAF) and diethylnitrosamine (DEN)] hepatocellular tumours of the C57Bl/10J mouse for H-ras, K-ras and N-ras gene mutations to see if mutational analysis of the ras genes could be useful for such a determination in this strain. Regions of DNA spanning codons 12, 13 and 61 of the ras genes were amplified from formalin fixed liver tumour sections using the polymerase chain reaction. Mutations were detected using allele specific oligonucleotide probing and confirmed by sequencing. We have found that there are few ras mutations in either spontaneous or chemically induced liver tumours in the C57Bl/10J mouse. Out of 25 spontaneous tumours two contained an A to T transversion and one contained an A to G transition in base 2 of H-ras codon 61 and two contained a G to A transition in base 2 of K-ras codon 13 (the K-ras mutations were only faintly detectable and may be present in a subpopulation of the tumour cells). In the case of the 18 ABP induced tumours one contained a C to A transversion in base 1 of H-ras codon 61, and one contained an A to T transversion in base 2 of H-ras codon 61 and one contained a G to C transversion in base 1 of K-ras codon 13. One C to A transversion in base 1 of H-ras codon 61 was detected out of eight AAF induced tumours. Of the 25 DEN induced tumours, one contained an A to G transition and one contained an A to C transversion in base 2 of H-ras codon 61. The data indicate that at least in hepatocellular tumours of the C57Bl/10J strain and using chronic dosing regimes the ras genes do not represent markers for in vivo genotoxic activity. 相似文献
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We report an adult female with a rare giant choledochal cyst. The patient presented following a normal pregnancy with the classical triad of an abdominal mass associated with jaundice and right upper quadrant abdominal pain. The cyst was excised using an intramural technique and biliary reconstruction achieved with a Roux-en-Y hepaticojejunostomy. Our patient has remained well with no evidence of malignancy over a 12 year review period. The aetiology and current management of this condition are discussed. 相似文献
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Donald F. Orton M.D. Dennis F. Strauss M.D. Michael Hummel M.D. Dale Orton M.D. F.A.C.E.P. 《Emergency radiology》1998,5(3):173-175
The intraperitoneal mass most commonly encountered after blunt abdominal truama is a hematoma. However, one must also consider
unusual bulky tumors that can have imaging characteristics similar to those of hematoma. The most typical of these neoplasms
is lymphoma, but a desmoplastic small cell tumor also may be observed. The presentation and imaging findings of a desmoplastic
small tumor are described. 相似文献
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C G Orton 《International journal of radiation oncology, biology, physics》1988,14(3):557-560
Conventional dose-effect relationships, such as those based upon the NSD or linear-quadratic concepts, do not account for dose inhomogeneities. Only a single "dose" value can be used in these equations and this can give rise to significant errors in the estimation of the "tolerance" dose in situations where dose distributions are inhomogeneous. This paper presents a method of "integrating" the biologically effective dose over the entire volume of each organ or tissue irradiated. Integral forms of the variable-exponent TDF and linear quadratic factor (LQF) models (ITDF and ILQF, respectively) can be used to determine whether or not any organ or tissue in an irradiated volume has exceeded tolerance, regardless of dose distribution non-uniformity. Several examples are given with comparisons to solutions obtained by conventional dose-effect models. 相似文献
10.
Na+ dependence of in vitro pancreatic amylase release 总被引:1,自引:0,他引:1