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111.
W F Bodmer C J Bailey J Bodmer H J Bussey A Ellis P Gorman F C Lucibello V A Murday S H Rider P Scambler 《Nature》1987,328(6131):614-616
Colorectal cancer is the second most common cancer in the United Kingdom and other developed countries in the West. Although it is usually not familial, there is a rare dominantly inherited susceptibility to colon cancer, familial adenomatous polyposis (FAP; also often previously called familial polyposis coli). During adolescence affected individuals develop from a few hundred to over a thousand adenomatous polyps in their large bowel. These are sufficiently likely to give rise to adenocarcinomas to make prophylactic removal of the colon usual in diagnosed FAP individuals. Adenomas may occur elsewhere in the gastrointestinal tract and the condition is often associated with other extracolonic lesions, such as epidermoid cysts, jaw osteomata and fibrous desmoid tumours. Adenomata have been suggested to be precancerous states for most colorectal tumours. Knudson has suggested that the mutation for a dominantly inherited cancer susceptibility may be the first step in a recessive change in the tumour cells, and that the same gene may be involved in both familial and non-familial cases of a given tumour. Following up a case report of an interstitial deletion of chromosome 5 in a mentally retarded individual with multiple developmental abnormalities and FAP, we have now shown that the FAP gene is on chromosome 5, most probably near bands 5q21-q22. 相似文献
112.
Leers MP Björklund V Björklund B Jörnvall H Nap M 《Cellular and molecular life sciences : CMLS》2002,59(8):1358-1365
We investigated the distribution and fate of apoptotic bodies during human development and in the adult, using an antibody
(M30) that recognizes a neo-epitope formed early in the apoptotic cascade by caspase cleavage of cytokeratin 18. In the fetus,
we found extensive accumulation of M30-positive, non-phagocytosed fragments in the red pulp of the spleen, subcutaneous and
submucosal vessels, the interstitium of the lung, and the glomerular mesangium of the kidneys. In the liver, M30-immunoreactive
fragments were found inside macrophages in the sinusoids. The number of these fragments and the intensity of the immunostaining
increased with the gestational age of the fetus. In the adult, M30-positive fragments were barely detectable in normal tissues.
However, many pathological situations, including both chronic degenerative processes and metastatic cancer, were associated
with accumulation of M30-positive fragments in the red pulp of the spleen. In the liver and kidney, no fragments could be
detected. Remarkably, 13 of the 16 patients with metastasized cancer showed pronounced accumulation of M30-positive fragments
containing hematoxylin-reactive material in the red pulp of the spleen. In the non-cancerous cases, such DNA-containing fragments
were only seen in 9 of 94 cases. The results show that when apoptotic activity is high, as during development in the fetus
or during metastasis and other pathological processes in the adult, the phagocytic clearance of apoptotic bodies can be overloaded.
These apoptotic fragments then accumulate in the spleen. The visual detection of apoptotic fragments is concluded to reflect
increased cell turnover.
Received 1 July 2002; accepted 1 July 2002 相似文献
113.
Screening for differentially expressed genes is a straightforward approach to study the molecular basis for changes in gene
expression. Differential display analysis has been used by investigators in diverse fields of research since it was developed.
Differential display has also been the approach of choice to investigate changes in gene expression in response to various
biological challenges in invertebrates. We review the application of differential display analysis of gene expression in invertebrates,
and provide a specific example using this technique for novel gene discovery in the nematode Caenorhabditis elegans. 相似文献
114.
115.
116.
Sox9 induces testis development in XX transgenic mice. 总被引:18,自引:0,他引:18
Mutations in SOX9 are associated with male-to-female sex reversal in humans. To analyze Sox9 function during sex determination, we ectopically expressed this gene in XX gonads. Here, we show that Sox9 is sufficient to induce testis formation in mice, indicating that it can substitute for the sex-determining gene Sry. 相似文献
117.
L Feliubadaló M Font J Purroy F Rousaud X Estivill V Nunes E Golomb M Centola I Aksentijevich Y Kreiss B Goldman M Pras D L Kastner E Pras P Gasparini L Bisceglia E Beccia M Gallucci L de Sanctis A Ponzone G F Rizzoni L Zelante M T Bassi A L George M Manzoni A De Grandi M Riboni J K Endsley A Ballabio G Borsani N Reig E Fernández R Estévez M Pineda D Torrents M Camps J Lloberas A Zorzano M Palacín 《Nature genetics》1999,23(1):52-57
118.
Direct multicriteria clustering algorithms 总被引:1,自引:0,他引:1
In a multicriteria clustering problem, optimization over more than one criterion is required. The problem can be treated in
different ways: by reduction to a clustering problem with the single criterion obtained as a combination of the given criteria;
by constrained clustering algorithms where a selected critetion is considered as the clustering criterion and all others determine
the constraints; or by direct algorithms. In this paper two types of direct algorithms for solving multicriteria clustering
problem are proposed: the modified relocation algorithm, and the modified agglomerative algorithm. Different elaborations
of these two types of algorithms are discussed and compared. Finally, two applications of the proposed algorithms are presented.
Elaborated version of the talks presented at the First Conference of the International Federation of Classification Societies,
Aachen, 1987, at the International Conference on Social Science Methodology, Dubrovnik, 1988, and at the Second Conference
of the International Federation of Classification Societies, Charlottesville, 1989.
This work was supported in part by the Research Council of Slovenia. 相似文献
119.
Pteroyl polyglutamate hydrolase (folyl conjugase), which hydrolyses the dietary polyglutamyl folates into simple forms prior to absorption, has been shown to be induced in rat pancreas in response to dietary polyglutamyl folates but not by ingestion of synthetic unconjugated folates. Folate absorption, as measured by the rise in serum folate levels after ingestion, of dietary conjugated folates is impaired in pancreatectomised animals whereas absorption of synthetic simple folate is not. A severe build-up of folyl conjugase is observed in the lumen of control but not in pancreatectomised animals after dietary folate ingestion. These results taken together would suggest that dietary folates are hydrolysed to monoglutamyl forms suitable for absorption in the lumen; the hydrolysis is catalysed by a luminal folyl conjugase of pancreatic origin induced by dietary conjugated folates. 相似文献
120.
A. Fabbri G. Cruccu P. Sperti M. Ridolfi T. Ciampani M. G. Leardi S. Ferracuti V. Bonifacio 《Cellular and molecular life sciences : CMLS》1992,48(11-12):1139-1142
Piroxicam is a nonsteroidal anti-inflammatory drug with a potent analgesic effect. In order to establish whether the analgesic action of Piroxicam has a central component, we studied the effect of the drug on the nociceptive orbicularis oculi reflexes evoked by electrical stimulation of the cornea and supraorbital nerve in healthy subjects. Piroxicam significantly suppressed the corneal reflex and R3 component of the blink reflex by 28% (p<0.05) and 50% (p<0.01), respectively. This effect was not reversed by the i.v. injection of naloxone. Beta-endorphin levels did not change. Piroxicam administration induces distinct inhibitory changes in nociceptive reflexes, which suggests that the analgesic action of the drug has a central component. The ineffectiveness of naloxone, and the lack of beta-endorphin changes, indicate that this central action is independent of the opioid system; other pain regulatory systems are probably involved. 相似文献