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991.
992.
993.
Childhood leukaemia in areas with different radon levels: a spatial and temporal analysis using GIS 总被引:6,自引:2,他引:4 下载免费PDF全文
OBJECTIVES—To evaluate the relation between exposure to ground radon levels and leukaemia among children using existing population and disease registers.
DESIGN—Ecological correlation study.
SETTING—The county of Östergötland in Sweden.
METHODS—Every child born in the county between 1979 and 1992 was mapped to the property centroid coordinates by linking addresses in the population and property registers. Population maps were overlaid with radon maps and exposure at birth and each subsequent year was quantified as high, normal, low or unknown. This was analysed with data from the tumour registry. Standardised mortality ratios (SMRs) were calculated using the age and sex specific rates for Sweden for the year 1995.
RESULTS—90 malignancies occurred among 53 146 children (498 887 person years) who formed the study population. SMRs for acute lymphatic leukaemia (ALL) among children born in high, normal and low risk areas were 1.43, 1.17 and 0.25 respectively. The relative risk for the normal risk group and high risk group as compared with the low risk group was 4.64 (95% CI 1.29, 28.26) and 5.67 (95% CI 1.06, 42.27). The association between ALL and continued residence at normal or high risk areas showed a similar trend. No association between radon risk levels and any other malignancy was seen.
CONCLUSION—Children born in and staying at areas where the risk from ground radon has been classified as low are less likely to develop ALL than those born in areas classified as normal and high risk.
相似文献
DESIGN—Ecological correlation study.
SETTING—The county of Östergötland in Sweden.
METHODS—Every child born in the county between 1979 and 1992 was mapped to the property centroid coordinates by linking addresses in the population and property registers. Population maps were overlaid with radon maps and exposure at birth and each subsequent year was quantified as high, normal, low or unknown. This was analysed with data from the tumour registry. Standardised mortality ratios (SMRs) were calculated using the age and sex specific rates for Sweden for the year 1995.
RESULTS—90 malignancies occurred among 53 146 children (498 887 person years) who formed the study population. SMRs for acute lymphatic leukaemia (ALL) among children born in high, normal and low risk areas were 1.43, 1.17 and 0.25 respectively. The relative risk for the normal risk group and high risk group as compared with the low risk group was 4.64 (95% CI 1.29, 28.26) and 5.67 (95% CI 1.06, 42.27). The association between ALL and continued residence at normal or high risk areas showed a similar trend. No association between radon risk levels and any other malignancy was seen.
CONCLUSION—Children born in and staying at areas where the risk from ground radon has been classified as low are less likely to develop ALL than those born in areas classified as normal and high risk.
相似文献
994.
用60Co-γ射线对家兔进行全身慢性均匀照射(0.05GY/α),当累积剂量分别达到0.05;0.10,0.15,0.20.0.25,0.3OGY时,静脉取血,常规条件下培养,分别在淋巴细胞的C0(培养前)和G2期(培养48h)以1.5GyYχ射线一次照射。培养至52h制备染色体标本,观察家兔接受不同低剂量γ射线(D1)全身照射后,对相继较大剂量χ射线(D2)所诱导的细胞遗传学损伤的抗性,结果表明在G0期和G2期受大剂量γ射线照射后,D1分别在0.15Gy和0.20GY上可诱导出明显的适应性反应(P<0.05),而在0,10或0.15GY以下则不能诱导出适应性反应,从而为能诱导出适应性反应的最低D1剂量提供了参考。 相似文献
995.
Jasti S. Rao Alan Rayford Masaaki Yamamoto K. Kian Ang Philip Tofilon Raymond Sawaya 《Journal of neuro-oncology》1994,22(2):161-171
Summary Radiation-induced damage to the central nervous system is believed to be targeted to glial or endothelial cells or both, although the pathophysiology of this process is still poorly understood. A series of experiments were, therefore, conducted, including irradiation to primary rat astrocytes (in vitro) and rat spinal cords (in vivo). The levels of plasminogen activators (uPA and tPA) and their inhibitors (PNI and PAI-1) were determined by fibrin zymography, ELISA, amidolytic activity assay, complex formation, and Western blot analysis. Fibrin zymography revealed the presence of Mr 48,000 (uPA) and Mr 68,000 (tPA) lytic bands that were increased in irradiated samples. Three- to four-fold higher levels of tPA and 8- to 10-fold higher levels of uPA were detected in irradiated samples. Western blot analysis confirmed the presence of a 51-kDa band (PAI-1) in irradiated samples. PAI-1 is undetectable in nonirradiated spinal cord. Serum-free medium and cell and spinal cord extracts of nonirradiated samples showed a 43-kDa band (PNI), the intensity of which is decreased in irradiated samples. Four- to five-fold decreased levels of PNI were detected in irradiated serum-free media and cell extracts, but no levels of PNI were detected in irradiated spinal cord extracts. This study provides additional information regarding the proposed roles of plasminogen activators and their inhibitors in the development of CNS damage after irradiation. 相似文献
996.
Ductal carcinoma in situ (DCIS) is an early, localized stage of breast carcinoma that has an excellent prognosis when it is properly treated. The significant increase in the frequency of diagnosis of DCIS in recent years is the result of both better recognition of DCIS among pathologists and widespread use of screening mammography. Multicentricity, bilaterality and histologic subtype are important considerations in the management of this disease. The clinical presentation of DCIS is the presence of either a palpable mass or a mammographic abnormality, most frequently in the form of an area of microcalcifications.For several decades, total mastectomy was considered the appropriate treatment for DCIS, and it should still be considered the standard to which more conservative forms of treatment must be compared. Breast conservation surgery has been used with increasing frequency in the treatment of DCIS but the adequacy of this approach remains subject to controversy. Segmental mastectomy alone may be applied with caution in carefully selected patients, while the rest of the patients undergoing breast conservation surgery should be treated with breast irradiation. Axillary node dissection is generally considered unnecessary in the treatment of DCIS. There is no role for adjuvant chemotherapy in the management of this disease. The role of tamoxifen in the treatment of DCIS is not clearly defined and it should be given only to patients enrolled in clinical trials. Ongoing research should clarify the controversies surrounding DCIS and enable us to define the optimal management for this disease. 相似文献
997.
998.
The outcome of radiotherapy in patients with stage I testicular seminoma was evaluated. During the period 1960–89 (inclusive) 270 patients with stage I seminoma of the testis received radiotherapy to the para-aortic nodes and ipsilateral hemipelvis following radical orchidectomy. Two hundred and fifty seven patients (95.2%) received a minimum tumour dose of 30Gy in 20 daily fractions using 4–6 MV photons. The 5 year overall and recurrence-free survival rates were 97 and 95%, respectively. Only eight of the 270 patients relapsed and three were cured with ‘salvage’therapies. Of the 11 patients who died, four deaths (36%) were the result of uncontrolled testicular cancer, six (55%) intercurrent illness and one (9%) the result of attempted salvage. Patients staged and treated prior to 1979 had a significantly worse disease-free survival compared to patients treated during and after 1979. As side effects were negligible, it was concluded that radiotherapy for stage I seminoma provides excellent cure rates. The difficulties arranging a ‘surveillance’programme in so large a State as Queensland are discussed. 相似文献
999.
Daniel M. Green Stephen B. Edge Remedios B. Penetrante Suraj Bakshi Donald Shedd Michael A. Zevon 《Pediatric blood & cancer》1995,24(2):82-86
We reviewed the courses of patients treated during childhood or adolescence for thyroid cancer to estimate the frequency of, and to identify possible risk factors for, the occurrence of second malignant tumors in this population. We identified all patients treated for thyroid cancer in a cohort of 1,406 pediatric cancer patients who were diagnosed prior to 20 years of age during the period January 1, 1960 through December 31, 1988 and who were treated at Roswell Park Cancer Institute. Twelve patients were treated for thyroid cancer, of whom nine were women. In situ breast carcinoma was diagnosed 25 and 26 years after diagnosis of thyroid cancer in two of four women treated with radioiodine. No new cancers were diagnosed in the five women treated with thyroidectomy only. Two of four women treated for thyroid cancer during adolescence with radioiodine, which is concentrated in the breast as well as other organs, developed in situ breast carcinoma. Review of a large cohort of adolescent female thyroid cancer patients treated with radioiodine is necessary to provide an accurate estimate of their risk of developing breast cancer. These patients must remain under medical surveillance throughout their lifetimes to facilitate prompt diagnosis of and early intervention for new conditions, such as the occurrence of breast cancer. © 1995 Wiley-Liss, Inc. 相似文献
1000.
Keith J. Stelzer MD PhD Wui-Jin Koh MD Benjamin E. Greer MD Joanna M. Cain MD Hisham K. Tamimi MD David C. Figge MD Barbara A. Goff MD Thomas W. Griffin MD 《American journal of obstetrics and gynecology》1995,172(6):1881-1888
Objective: Our purpose was to evaluate the contribution of intraoperative radiation therapy in the management of recurrent cervical cancer.Study design: Twenty-two patients were treated with electron beam intraoperative radiation therapy for recurrent cervical cancers that were confined to the pelvis but were too extensive to be adequately treated by radical surgery alone. All patients underwent extensive surgical dissection for exposure and maximal tumor resection. Doses of intraoperative radiation therapy ranged from 14 to 27.8 Gy (median 22 Gy). Twelve patients received intraoperative radiation therapy to address gross residual disease, and 10 patients were treated for microscopically positive or close surgical margins.Results: The five-year disease-specific survival and local control rates were 43% and 48%, respectively. There were trends toward better local control and disease-specific survival in patients with microscopic residual disease compared with those with gross residual disease. Seven patients had peripheral neuropathy related to treatment, and four of these cases resolved.Conclusion: In carefully selected cases intraoperative radiation therapy contributes to radical salvage of patients with recurrent cervical cancer involving the pelvic wall. 相似文献