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排序方式: 共有75条查询结果,搜索用时 31 毫秒
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OBJECTIVE: To determine the results peranal excision for rectal carcinoma. DESIGN: Retrospective case series. SETTING: A university-affiliated hospital. PATIENTS: Of 178 patients who presented for curative resection of rectal carcinoma between 1975 and 1993, 19 (10.7%) were deemed suitable for local excision. There were 10 men and 9 women with a mean age of 71.2 years. The follow-up ranged from 13 to 184 months. INTERVENTION: Peranal excision. MAIN OUTCOME MEASURES: Histologic differentiation, gross morphology, depth of invasion and size of the carcinoma, adequacy of margins of excision, complications of operation, rates of recurrence, results of salvage therapy and 5-year survival. RESULTS: There were no intraoperative complications. Postoperative complications included urinary retention (one patient) and bleeding (one patient). There were five local recurrences (26%). Salvage operations were performed in three (60%) patients and were successful in two of them. The 5-year cancer-specific survival rate was 82%. The recurrence rate was higher in patients with inadequate margins of excision and ulcerative lesions. Neither size nor grade of the carcinoma correlated with recurrence. CONCLUSIONS: Local excision of rectal carcinoma can be performed successfully in selected patients. Diligent follow-up is required, because up to 60% of local recurrences can be treated successfully. 相似文献
3.
S Frame R Crombie J Liddell D Stuart S Linardopoulos H Nagase G Portella K Brown A Street R Akhurst A Balmain 《Canadian Metallurgical Quarterly》1998,353(1370):839-845
Tumour formation relies on a complex combination of genetic and environmental factors. In particular, the contributions from inherited predisposition genes as well as carcinogens, for example from cigarettes or in the diet, are amongst the major contributors to tumorigenesis. Since the study of such processes in particularly difficult in human cancers, the availability of a well-defined model system is of obvious benefit. The mouse skin model of multistage carcinogenesis offers an excellent tool for the study of the target cells, the target genes and the biological events associated with neoplasia. In this system, tumorigenesis occurs in a series of defined stages, each of which is characterized by specific and reproducible alterations in genes such as H-ras, cyclin D1, p53 and p16INK4A. Additional changes occur in the production of, or response to, factors such as transforming growth factor beta (TGF beta). These genetic and biological alterations are mirrored in human tumours of epithelial origin. Hence, research into the general principles of tumour initiation, promotion and progression in the context of the mouse skin model is likely to prove valuable in the continual search for new methods for the diagnosis, prevention, and therapeutic treatment of human cancers. 相似文献
4.
Propagation of mechanically induced intercellular calcium waves via gap junctions and ATP receptors in rat liver epithelial cells 总被引:1,自引:0,他引:1
Mechanical stimulation was used to initiate Ca2+ waves in rat liver epithelial cells in order to ascertain the degree to which gap junctional intercellular communication (GJIC) is involved in communication of Ca2+ to adjacent cells and to assess alternative Ca2+ signaling pathways that may be present between these cells. In both WB-F344 cells, which show a high degree of GJIC, and WB-aB1 cells, which are GJIC deficient, mechanical stimulation of a single cell induced a Ca2+ wave which propagated away from the point of stimulation, across cell borders, to neighboring cells directly or indirectly in contact with the stimulated cell. In addition, the Ca2+ wave was transmitted to nearby isolated cells that exhibited no direct or indirect contact with the stimulated cell. Treatment of cells with 18beta-glycyrrhetinic acid, a compound that has been shown to block GJIC, did not significantly affect propagation of the Ca2+ wave. In contrast, treatment with suramin, a P2-purinergic receptor inhibitor, significantly reduced both the rate and the extent of Ca2+ wave propagation in WB-F344 cells and completely blocked its propagation in WB-aB1 cells. Cotreatment with suramin and glycyrrhetinic acid was found to completely block the mechanically induced Ca2+ wave in both cell lines. These studies indicate that mechanically induced cell injury in rat liver epithelial cells initiates signaling through at least two pathways, involving intercellular communication via gap junctions and extracellular communication via ATP activation of purinergic receptors. 相似文献
5.
JA Steer RP Papini AP Wilson S Dhillon MF Hichens DA McGrouther JD Frame N Parkhouse 《Canadian Metallurgical Quarterly》1996,37(3):545-553
Patients with severe burns are susceptible to infection with Gram-positive organisms including methicillin-resistant Staphylococcus aureus, and often require higher antibiotic dosages compared with other patients. This study examined the pharmacokinetics of a single iv dose of teicoplanin (12 mg/kg) in 15 adults and five children with severe burns. Adults were aged 21-82 years with a median total body surface area (TBSA) burn of 30% (range 15-60%). Children were aged 10 months-l0 years with median TBSA burn of 15% (10-30%). At 12 h, the median serum teicoplanin concentration was 12.8 mg/L (9.027.1 mg/L) in adults and 7.6 mg/L (6.6-l0.8 mg/L) in children, (P < 0.01); at 24 h, the corresponding values were 8.3 mg/L (4.6-l2.9 mg/L) and 5.2 mg/L (4.2-6.0 mg/L). Using a three-compartment model, the median terminal half life in adults was 114 h (47-278 h). Children fitted a two-compartment model with a terminal half-life of 38 h (2l-41 h). The median concentration of teicoplanin in fluid from the burn wound was 60% of the serum antibiotic concentration. A single iv dose of 12 mg/kg of teicoplanin was sufficient to produce therapeutic serum concentrations in burn patients for 24 h, but monitoring of antibiotic levels in serum may be advisable in those with high total clearance, especially children. 相似文献
6.
7.
Measuring scientific activity in lesser developed countries 总被引:1,自引:1,他引:0
J. D. Frame 《Scientometrics》1980,2(2):133-145
Quantitative indicators of scientific and technological activity are often of questionable validity and reliability. This is particularly true in lesser developed countries, where the lack of data gathering skills may frequently result in the development of misleading indicators. A number of manpower, education, expenditure, and publication indicators are examined for thirteen Middle Eastern countries. Reliability and validity problems are discussed for each indicator. The indicators are found to correlate with each other in reasonable ways, suggesting that despite their possible flaws, they nonetheless appear to measure scientific activity with some consistency. 相似文献
8.
An investigation of the relationship between NIH funding and biomedical publication output is reported for 229 major NIH supported institutions. A correlation of 0.95 was found between the amount of NIH funding and the number biomedical publications for 132 U.S. universities. For 52 hospitals a correlation of 0.89 was found. For all 229 institutions it was found that NIH provided 91% of the boimedical research support from major federal agencies, and more than half of the total extramural biomedical research support. There was no indication of either economies or diseconomies of scale in the number of publications produced by the institutions, which ranged from a few publications per year to over 700 per year. 相似文献
9.
Methyl and ethyl monoalkyl esters of various vegetable oils were produced for determining the effects of type of alcohol and
fatty acid profile of the vegetable oil on the lubricity of the ester. Four methyl esters and six ethyl esters were analyzed
for wear properties using the American Society for Testing and Materials method D 6079, Evaluating Lubricity of Diesel Fuels
by the High-Frequency Reciprocating Rig. Ethyl esters showed noticeable improvement compared to methyl esters in the wear
properties of each ester tested. No correlation was found between lubricity improvement and fatty acid profile of the ester,
except that esters of castor oil had improved lubricity over other oils with similar carbon chain-length (C18) fatty acids. 相似文献
10.
J. D. Frame 《Scientometrics》1984,6(4):223-232
The paper examines a not too comprehensive set of quantitative aspects of technology. It concentrates mainly on the quantification of management tools.This paper was originally presented to the First Panamerican Workshop on Quantitative Methods in Science Policy and Technology Forecasting, 7–9 February 1983, San Jose, Costa Rica. 相似文献