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1.
RH Greiner 《Canadian Metallurgical Quarterly》1998,87(17):595-601
Breast-conserving surgery is now commonly used to treat breast cancer. While mastectomy has been the traditional treatment for ductal carcinoma in situ, it is felt to be excessive in most cases. A great effort has been made to identify pathobiological characteristics of DCIS that can be used to identify patients best suited for wide local excision vs. wide local excision and breast irradiation. Mastectomy and conservative surgery plus irradiation offer a similar outcome in patients with early stage invasive breast cancer. Radiotherapy has not been shown to improve survival but is able to reduce significantly the rate of local recurrence, which is regarded as a very undesirable outcome. There is still controversy concerning the necessity of irradiation of the breast in all patients. Analysis of predictors of outcome cannot identify a subgroup of patients with a very low risk for local breast recurrence who might not require radiation therapy. In premenopausal, node-positive breast cancer patients XRT has a beneficial effect not only on locoregional but also on systemic recurrences. Radiotherapy has to be integrated for a pre- or postoperative consolidation in new treatment concepts for locally advanced breast cancer which use primary chemotherapy and immediate or subsequent breast radiation. Radiation of internal mammary chain and supraclavicular fossa after conservative surgery does not lead to an increase in clinically important skin or pulmonary complications. Its role is being evaluated in current multicentre studies. 相似文献
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In immediate free recall, words recalled successively tend to come from nearby serial positions. M. J. Kahana (see record 1996-93836-009) documented this effect and showed that this tendency, which the authors refer to as the lag recency effect, is well described by a variant of the search of associative memory (SAM) model (J. G. W. Raaijmakers & R. M. Shiffrin, 1980, 1981). In 2 experiments, participants performed immediate, delayed, and continuous distractor free recall under conditions designed to minimize rehearsal. The lag recency effect, previously observed in immediate free recall, was also observed in delayed and continuous distractor free recall. Although two-store memory models, such as SAM, readily account for the end-of-list recency effect in immediate free recall, and its attenuation in delayed free recall, these models fail to account for the long-term recency effect. By means of analytic simulations, the authors show that both the end of list recency effect and the lag recency effect, across all distractor conditions, can be explained by a single-store model in which context, retrieved with each recalled item, serves as a cue for subsequent recalls. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Alcohol use, binge drinking, and substance abuse-related consequences among students with varying levels of participation in intercollegiate athletics were examined. Between October 1994 and May 1996, 51,483 students at 125 institutions answered questions about their involvement in athletics, ranging from noninvolvement to participant to leadership positions, on the long form of the Core Alcohol and Drug Survey. In comparisons with nonathletes, both male and female athletes consumed significantly more alcohol per week, engaged in binge drinking more often, and suffered more adverse consequences from their substance use. No support was found for the hypothesis that athletic leaders were more responsible than other team participants in using alcohol. Male team leaders appeared to be at significantly greater risk than female team leaders; they also consumed more alcohol, binged more often, and suffered more consequences than other team members. 相似文献
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JP Logue CL Sharrock RA Cowan G Read J Marrs D Mott 《Canadian Metallurgical Quarterly》1998,41(4):929-931
PURPOSE: The pivotal step in radiation planning is delineation of the target volume and production of a treatment plan to encompass this. This study assesses the variation of physicians in creation of these volumes. METHODS AND MATERIALS: Three radiologists and eight radiation oncologists outlined the gross tumour volume (GTV) on the planning CT scans of four cases with T3 bladder cancer. In addition, the radiation oncologists (RO) created a planning target volume according to a set protocol for all cases. Volumes were produced and comparison of these volumes and the position of the isocenters were analysed. In addition, the margins allowed were measured and compared. RESULTS: There was a maximum variation ratio (largest to smallest volume outlined) of the GTV in the four cases of 1.74 among radiologists and 3.74 among oncologists. There was a significant difference (p = 0.01) in mean GTV between RO and the radiologists. The mean GTV of the RO exceeded the radiologists by a factor of 1.29 with a mean difference of 13.4 cm3. The variation ratio in PTV among oncologists ranged from 1.25 to 3.33. There was no significant difference in mean PTV values between the two groups of ROs divided by specialization in uro-oncology. The mean variation in location of the isocenter from the centroid of the radiologists' volume in the four cases was from 2.6 to 5.7 mm. There was, however, a wide range of values from 1.4 mm to 24.1 mm. Median margin per case ranged from 14.7 to 18.7 mm. Minimum margins allowed in each case varied from minus 7 mm to 9 mm. CONCLUSION: This study demonstrates significant interphysician variability in producing target volumes and radiation plans for conformal radiotherapy. The scale of this difference is clearly of significance, with up to 3-fold variation in volumes delineated by clinicians. The factors leading to these differences will be further addressed. The existence of such variability, however, clearly needs to be accepted as a factor in the overall uncertainty analysis in conformal radiotherapy planning. 相似文献
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M Roach 《Canadian Metallurgical Quarterly》1996,10(8):1143-53; discussion 1154-61
Pretreatment prostate-specific antigen (PSA) level is the single most important prognostic factor for patients undergoing radiotherapy for clinically localized prostate cancer. When combined with Gleason score and T-stage, pretreatment PSA enhances our ability to accurately predict pathologic stage. Patients with pretreatment PSA levels > 10 ng/mL are at high risk for biochemical failure when treated with conventional radiation alone. A PSA nadir of > 1 ng/mL and a post-treatment PSA > 1.5 ng/mL are associated with a high risk of biochemical failure. Postoperative radiotherapy delivered while the tumor burden is low (eg, PSA < 1 ng/mL) predicts a favorable outcome. Many of these conclusions about the usefulness of pretreatment PSA are based on the assumption that PSA can be used as a surrogate end point for disease-free and overall survival from prostate cancer. However, this assumption still remains to be validated by phase III trials. 相似文献
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A rare case of amniotic disease with extensive malformations of fetus was described. A data obtained from literature was done with special consideration of etiopathology. 相似文献
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SI Zeitlin J Sherman A Raboy G Lederman P Albert 《Canadian Metallurgical Quarterly》1998,160(1):91-5; discussion 95-6
PURPOSE: We evaluate the efficacy of high dose combination radiotherapy for the treatment of localized prostate cancer. MATERIALS AND METHODS: A total of 212 patients with localized prostate cancer (T1-T3) were treated with transperineal radioactive seed implantation followed by 45 Gy. external beam radiation therapy. Patients with Gleason scores of 2-5 were treated with 125iodine at a minimum peripheral dose of 120 Gy., while 103palladium at a minimum peripheral dose of 90 Gy. was used for those with Gleason scores of 7-10. Patients with Gleason 6 diploid tumors were treated with 125iodine and those with aneuploid tumors were treated with 103palladium. Biochemical failure was defined as inability to achieve a prostate specific antigen nadir value of 0.5 ng./ml. or less. No patient was treated with androgen deprivation therapy. RESULTS: The 212 patients have a minimum of 24 months of followup (mean 33 months). Prostate specific antigen 0.5 ng./ml. or less was reached by 72% of the patients (152 of 212) and positive biopsies were detected in 13.9% (20 of 144). Using life table survivorship analysis the probability of initial biochemical success at 5 years was 91% (95% confidence interval, 83 to 97). The probability of subsequent failure following an initial success was 11% (95% confidence interval, 6 to 20) at 24 months. The complications of combination therapy included proctitis in 21.4% (47 of 212 men), impotence in 38% (38 of 100), urinary retention in 1.5%, incontinence in 2.8%, rectoprostate fistula in 2.4%, rectal wall breakdown in 0.5% and urethral stricture in 0.5%. Six patients (2.8%) required colostomy and urinary diversion. CONCLUSIONS: Short-term responses to high dose combination radiotherapy for localized prostate cancer are promising. The morbidity is acceptable. Further long-term followup is warranted to assess this treatment. 相似文献
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Amurstal' Plant. Translated from Metallurg, No. 10, pp. 12–13, October, 1992. 相似文献
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Between 1989 and 1996, 35 patients with prostate cancer without metastasis received intraoperative radiotherapy combined with external beam radiation. 10 of 16 stage B patients and all of 19 stage C patients received additional endocrine therapy for the initial treatment. The radiation therapy included 25-30 Gy of intraoperative radiotherapy for prostate and 30 Gy of external beam radiotherapy for small pelvic region. One patient of stage C was dead for cancer and 4 patient were dead for other causes during 15-99 (mean: 41.6) months follow up period. The overall actuarial survival at 5 years by Kaplan-Meier method were 92.3% for stage B and 87.2% for stage C. Although cystitis, proctitis and anal bleeding were observed as the adverse effects of radiotherapy, both acute and chronic symptoms were not critical. In conclusion, intraoperative radiotherapy combined with external beam radiotherapy was revealed as an effective treatment for prostate cancer without metastasis. 相似文献
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Adaptation to distorted faces is commonly interpreted as a shift in the face-space norm for the adapted attribute. This article shows that the size of the aftereffect varies as a function of the distortion level of the adapter. The pattern differed for different facial attributes, increasing with distortion level for symmetric deviations of eye height and decreasing for asymmetric deviations. These results are interpreted in terms of different coding ranges for the 2 facial attributes, arising from differences in eye-height variability in natural face images (large for symmetric, small for asymmetric). Neural models developed in low-level vision also are applied to facial attributes, contrasting a 2-pool (norm-based) and a multichannel (exemplar-based) model. The adapter position effects generally support a norm-based model, as did a finding that perception of stimuli further from the norm than the adapter was shifted in the direction of the norm, rather than repulsed away from the adapter. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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O González Sequeros VC Garrido García A García Cartagena 《Canadian Metallurgical Quarterly》1997,24(4):287-290
A consecutive series of 82 patients (98 legs) suffering from recurrent varicose veins underwent surgical treatment. In all patients clinical and hand-held US Doppler preoperative examinations were performed, but a phlebography was necessary in 33 legs to certainly visualize the anatomy of venous system and the potential sites of recurrent deep to superficial reflux. The causes of recurrence were: incompetent saphenofemoral junction in 59 legs, saphenopopliteal reflux in 6 legs, incompetence of perforator veins in 18 legs, both insufficiencies of great saphena and perforators in 15 legs. Seventy-four legs with saphenofemoral reflux underwent groin redissections through transversal (44 legs) or vertical (30 legs) incisions; the approach to the saphenopopliteal junction was vertical in two legs and transversal in four legs; the interruption of incompetent perforator veins was performed through incisions in 29 legs and according to Linton's technique in 4 legs. Clinical and US Doppler follow-up was performed every 6 months and no recurrent reflux was demonstrated; seven patients were affected from new small varices that were treated by injection sclerotherapy. This study indicates that more than 1/3 of recurrent varices need phlebography to be clearly studied: only diagnostic accuracy may assure a correct surgical approach, but the strategy of treatment must be adapted to the single patient. 相似文献
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PURPOSE: We compare the combination of orchiectomy and radiotherapy to radiotherapy alone as treatment for pelvic confined prostate cancer, that is T1-4, pN0-3, M0 (TNM classification). MATERIALS AND METHODS: In this prospective study 91 patients with clinically localized prostate cancer were, after surgical lymph node staging, randomized to receive definitive external beam radiotherapy (46) or combined orchiectomy and radiotherapy (45). Patients treated with radiotherapy alone had androgen ablation at clinical disease progression. The effects on progression-free, disease specific and overall survival rates were calculated. RESULTS: After a median followup of 9.3 years (range 6.0 to 11.4) clinical progression was seen in 61% of the radiotherapy only patients (group 1) and in 31% of the combined treatment patients (group 2) (p = 0.005). The mortality was 61 and 38% (p = 0.02), and cause specific mortality was 44 and 27%, respectively (p = 0.06), in groups 1 and 2. The differences in favor of combined treatment were mainly caused by lymph node positive tumors. For node negative tumors there was no significant difference in survival rates. CONCLUSIONS: The progression-free, disease specific and overall survival rates for patients with prostate cancer and pelvic lymph node involvement are significantly better after combined androgen ablation and radiotherapy than after radiotherapy alone. These results strongly suggest that early androgen deprivation is better than deferred endocrine treatment for these patients. 相似文献
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GS Mageras Z Fuks J O'Brien LJ Brewster C Burman CS Chui SA Leibel CC Ling ME Masterson R Mohan 《Canadian Metallurgical Quarterly》1994,30(4):971-978
PURPOSE: We have described previously a model for delivering computer-controlled radiation treatments. We report here on the implementation and first year's clinical experience with such treatments using a 50 MeV medical microtron. METHODS AND MATERIALS: The microtron is equipped with a multileaf collimator and is capable of setting up and treating a sequence of fixed fields called segments, under computer control. An external computer derives machine parameters for the segments from a three-dimensional treatment planning system, transfers them to the microtron control computer, checks the machine settings before allowing dose delivery to begin, and records the treatment. We describe the patient treatment methodology, portal film acquisition, electronic portal imaging, and quality assurance. RESULTS: Patient treatments began in July 1992, comprising six-segment conformal treatments of the prostate. Using the recorded treatment data, the system performance has been examined and compared to other treatment machines. The average treatment time is 10 min, of which 4 min is for computer-controlled setup and irradiation; the remaining time is for patient positioning and checking of clearances. Long-term reproducibility of computer-controlled setup of the gantry and multileaf position is better than 0.5 degrees and 1 mm, respectively. Termination due to a machine fault has occurred in 5.5% of treatments, improving to 2.5% in recent months. CONCLUSION: Our initial experience indicates that computer-controlled segmental therapy can be performed reliably on a routine basis. Treatment times with the microtron are significantly shorter than with conventional linacs, and setup accuracy is consistent with that needed for conformal therapy. We believe that treatment times can be further improved through software upgrades and integration of electronic portal imaging. 相似文献
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Fiber-optic biosensors that are selective for nitric oxide and do not respond to most potential interferents have been prepared with cytochromes c'. Both micro- and nanosensors have been prepared, and their response is fast (< 1 s), reversible, and linear up to 1 mM nitric oxide. The detection limit is 20 microM, making the sensor useful for some biological samples, such as the macrophages studied here. While sensors have been prepared based on the fluorescence of the cytochromes c', optodes with greatly enhanced signal-to-noise ratios have been made by labeling the cytochrome c' with a fluorescent dye. Comparisons of cytochromes c' from three species of bacteria as well as of two matrixes were performed and the optimum sensor configuration is described. 相似文献
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D Kahn RD Williams MK Haseman NL Reed SJ Miller J Gerstbrein 《Canadian Metallurgical Quarterly》1998,16(1):284-289
PURPOSE: We investigated the ability of In-111-capromab pendetide to separate patients who have failed radical prostatectomy into categories of those who would versus those who would not respond to salvage radiotherapy. METHODS: Prostate-specific antigen (PSA) levels in 32 men with prostate cancer who had failed radical prostatectomy and had undergone a whole-body In-111-capromab pendetide scan were followed-up for 13 months (median) after salvage radiotherapy to the pelvis. A logistic regression model was used to determine whether the scan findings, as well as other clinical variables, were associated with a durable complete response (DCR), a nondurable response (NDR), or no response (NR). RESULTS: Sixteen of 23 (70%) men with a normal scan outside the prostatic fossa achieved a DCR after salvage radiotherapy versus two of nine (22%) who had a positive scan outside the prostate fossa and pelvis (P = .0225, Fisher's exact test). Predicted probability (95% confidence interval [CI]) that a DCR would be obtained with a normal scan was 0.88 (0.55 to 0.98); for men with a positive scan limited to the prostatic fossa it was 0.62 (0.42 to 0.79); and for men with a positive scan outside the pelvis it was 0.27 (0.09 to 0.58). No other variables before radiotherapy showed a significant association with the DCR rate. CONCLUSION: Salvage radiotherapy is statistically more likely to lead to a durable complete PSA response in men with prostate cancer who have failed radical prostatectomy and have a negative In-111-capromab pendetide scan outside the pelvis as compared with those who have a positive scan. 相似文献
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Chloroform, the predominant constituent of solvents used for lipid extraction and chromatography, is believed to give rise to birth defects and serious damage to health, and may also be carcinogenic. Therefore, simple and successful methods have been developed to replace chloroform throughout the isolation of glycosphingolipids (GSLs) by less harmful solvents. Gangliosides of sheep brain (ganglio-series gangliosides GM1, GDla, GD1b and GT1b) and of lymphocyte-derived mouse hybridoma cells (namely GM3) were extracted with six different solvent mixtures. Chloroform:methanol:water (40:80:30, v/v/v) was employed as reference (solvent I). Combinations without chloroform were: n-propanol:water (40:10, v/v) (II), methylisobutylketone:methanol:water (40:80:30, v/v/v) (III), ethylacetate:methanol:water (40:72:28, v/v/v) (IV), methylacetate:methanol:water (40:72:28, v/v/v) (V) and petroleum ether:isopropanol:water (40:112:38, v/v/v) (VI). After extraction and dialysis, the weight of lipid extract as well as the content of sialic acid, gangliosides, sulphatides and phospholipids were determined. Quantitation of GSL yields in crude extracts obtained by the alternative solvent mixtures II to VI showed recoveries of brain gangliosides from nearly 67% up to 104% compared with the reference solvent I. Extraction of hybridoma cells by means of the alternative combinations without chloroform revealed at least the same and mostly better ganglioside yields in the range from 98% to 116% with regard to the reference solvent I. n-Propanol:water (II) and methylisobutylketone:methanol:water (III) were the recommended extractants for both tissues. Therefore, the methods described offer simple, less hazardous and successful strategies for GSL extraction in excellent yield without the need for using chloroform. 相似文献
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EM Sokal 《Canadian Metallurgical Quarterly》1998,61(2):170-174
Bacterial examinations of temporary pacing wires (P-wires), pulmonary arterial (P-A) catheters, and drainage tubes temporarily inserted during open-heart surgery were performed in 213 patients. Bacteria were detected in 19 (2.8%) of 672 specimens gathered from the subject patients, with coagulase-negative Staphylococcus (CNS) being most frequently observed. P-wires accounted for 17 out of 19 of the culture-positive specimens, and 7 of the P-wires remained in place for more than two weeks. The frequency of infection with the P-wires was significantly higher than with the P-A catheters or drainage tubes. The period of time that the P-wire was left in place significantly longer than for P-A catheter or drainage tube. There was, however, no statistically significant difference between the culture-positive and negative groups in respect to age, detention periods, operation times, CPB times, or length of ICU stay. As a result of these findings, we have concluded that P-wires should be removed as soon as possible following surgery, and in any case, a meticulous care should be taken to prevent transcutaneous infection. 相似文献