一种定量评估化学物质致癌性的新方法——比值评估法

作者提出一种在诱变试验中定量评估化学物质致癌性的新方法——比值评估法。该法应用有关概率公式,结合各试验的灵敏度和特异度,用比值简化运算,求得化学物在结果群条件下为致癌物的概率,此方法的优点在于只需了解P(C~+)的范围,而不必先确定其确切值,并且只作较简便的运算,就能得到P(C~+/M)的估计值及误差。此法在毒理测试结果评价中有一定实用价值。     

测定潜在致癌物的设想

美国一化学研究小组发展了预测致癌物效能的一种简单模式。许多化学制品为潜在致癌物。重要的问题是试图鉴别哪些是致癌物,哪些经人体代谢后成为无害的物质。科学家们根据动物试验来测定致癌性,但实验结果常受动物的年龄、健康、是否纯种以及致癌物剂量所影响。其他预测致癌性的理论模式涉及十分复杂的定量机械计算。但是新模式只需对该物质分子的化学结构加以检查即     

遗传毒理学试验预测致癌物的作用和策略

对我们建立的化学物致癌性和遗传毒性数据库分析,证实以遗传毒理学试验预测致癌物具有不肯定性。在常规使用的试验中,首选沙门氏菌回变试验,不同试验之间多数是统计学上不独立的。试验组应由检测不同遗传学终点的试验组成并至少包括一个哺乳动物体内试验。我们推荐遗传毒理学试验和致癌试验相结合的检测致癌物序贯试验方案。     

用微生物诱变试验对几种有机氮杀虫剂致癌性的初步探讨

鉴定农药的致癌性是全面评价农药安全性的重要组成部分。过去沿用的动物实验法,需时两年左右,费用大,远不能满足生产上要求。Ames(1971)提出的微生物诱变试验法,具有快速、经济和预测效果好等优点,是快速筛选化学致变物从而推测致癌物的一种较好的方法。本文试     

微囊藻毒素、佛波酯和苯巴比妥钠对细胞间隙通讯和细胞内Ca2+浓度的影响

目的:探讨细胞间隙通讯和细胞钙离子信号传导系统在非遗传毒性致癌物的遗传外致癌过程中的作用.方法:应用划痕染料示踪技术(SLDT)和fluo-3荧光标记法,测定微囊藻毒素、佛波酯(TPA)、苯巴比妥钠3种非遗传毒性致癌物对BALB/c 3T3细胞间隙通讯功能和细胞内游离Ca2+离子浓度的影响.结果:3种非遗传毒性致癌物均可不同程度抑制细胞间隙通讯功能,并呈良好的剂量效应关系.TPA和微囊藻毒素可明显诱导细胞内游离钙离子浓度升高,但在试验剂量下苯巴比妥钠未见引起细胞内Ca2+离子浓度的明显改变.结论:细胞间隙通讯系统可能是3种非遗传毒性致癌物的共同作用位点,对细胞Ca2+系统的影响以TPA类非遗传毒性致癌物为主.     

关于程序外DNA合成(UDS)试验

化学物引发动物的致癌反应,是通过不同机理发生的。因此,通常把化学致癌物分成两大类:一是遗传毒物,指通过对遗传物质起作用的物质;二是外遗传毒物,指通过慢性组织损伤、激素平衡失调和其他促癌作用的化学物。不同物质可引起不同类型的遗传损伤。大多数检测化学致癌物的方法是利用细菌、哺乳动物细胞;选择某些遗传毒作用如致突变作用、染色体作用、细胞转化等作为观察指标。很多试验是单终点的。因此,不是所有化学致癌物,在单一的短期试验中都能被检出。而是需要一组试验(系列实验)。     

体外人胚肺成纤维细胞原代培养的方法探讨

近年来,为了确定环境致癌物与人类肿瘤的关系,趋于建立以人体细胞做为靶细胞系统的短期试验系统,检测环境物质对人类的潜在致癌性。体外上皮细胞培养要求的实验条件较高,比较困难,所以培养人成纤维     

预测致癌性的遗传毒理学试验组合的选择和序贯判别方法

本文把序贯判别方法应用于以遗传毒理学试验预测化学品的致癌性,优化预测的社会效益。给出了遗传毒理学试验组合的较佳选择方案以及实用的序贯判别方法。推荐以沙门氏菌回变试验为第一个试验,啮齿类骨髓微核试验为第二个试验,哺乳动物细胞SCE试验或哺乳动物细胞UDS试验或啤酒酵母有丝分裂重组试验为第三个试验。本文还改进了Titterington处理缺失数据的统计方法。     

有机氟化物的生物化学

有机氟化物在医学及健康有关的科学中起着重要的作用。本文对有机氟化物在生物化学各领域中的发展作一概括的论述。一、化学致癌物的研究多核芳香族化合物的致癌性巳得到广泛的研究。通过含氟的多核芳香族化合物,可以从分子水平研究其致癌性;这是由于氟原子与这些致癌物中的致癌部位键合时,可以抑制癌的生长。通过对这些含氟化合物的研究,已证明下述三种致癌物中的致癌原子的位置分別是: (Ⅰ)7—甲基苯并蒽中的第5位置。     

莫合烟对金黄色地鼠胚胎细胞转化作用的研究

目的：检测新疆产莫合烟的致癌性。方法：体外金黄色地鼠胚胎细胞转化试验。结果：莫合烟烟雾凝聚物在剂量分别为１５．６、３１．２、６２．４μｇ／ｍｌ时均可诱发叙利亚金黄色地鼠胚胎细胞（ＳＨＥ）发生恶性转化，转化灶的细胞呈多层生长，交叉重叠，无方向性，核浆比例增大。结论：莫合烟中含有致癌物，可以诱发细胞恶性变。     

An approach to the evaluation and documentation of adverse drug reaction

This paper reviews an approach to the evaluation and documentation of suspected adverse drug reaction (ADR). I propose an algorithm for the evaluation of suspected ADR. I recommend that the adverse drug reaction scoring system(ASS) or the adverse drug reactions probability scale(APS) be used when evaluating suspected ADR. In these two scoring systems, points are allotted according to response to a series of questions on events relating to the clinical manifestations of the suspected ADR. Depending on the total points scored the probability of the suspected ADR are classified as definite, probable, possible and unlikely. When a patient's suspected ADR is classified as definite, then no further investigation is necessary. The patient should be considered sensitive to the drug. In a case where the suspected ADR is classified as probable or possible then further investigations should be considered to confirm the diagnosis. If the nature of ADR is life threatening only in-vitro test should be done. If the nature of ADR is not life threatening, in-vivo and oral provocative test dosing may be considered. It should be considered if the suspected drug in question cannot be substituted and when it is very frequently prescribed.     

颈椎后路一次性手术治疗颈椎管狭窄合并颈椎间盘突出

目的探讨颈椎管狭窄合并颈椎间突出一次性后路减压和髓核摘除的手术方法以及手术时应注意的问题。方法 :经颈椎后路摘除椎间盘 38例。局麻、俯卧位 ,颈椎后路单开门椎管扩大成形后 ,以病变间隙为中心 ,纵行切开硬脊膜 ,根据需要切断病变侧 2～ 3条齿状韧带 ,将脊髓轻轻向中线牵拉 ,摘除突出的髓核。结果 :38例中 35例获得平均 3年 2个月 (6个月～ 7年 10个月 )的随访 ,优 2 1例 ,良 11例 ,有效 3例 ,避免前、后路 2次手术 ,效果满意 ,但应选择好手术适应证 ,手术操作时应注意对脊髓和神经根的牵拉以及对齿状韧带与神经根的辨认等问题。     

Effects of discectomy on the stress distribution in the lumbar spine.

The change of the stress distribution of the lumbar spine after discectomy was analysed by the three-dimensional finite element method. It was shown that the stress level in the posterior element was higher, but that in the anterior element was lower than before disc excision. The most significant change of the stress distribution was found in the trabecular bone of the vertebral body. It is considered that in discectomy the normal disc tissue should be preserved as much as possible to maintain good function of the spine.

     

Diagnosis of a posterior fossa tumour by magnetic resonance imaging

The application of magnetic resonance imaging as a diagnostic tool for diseases of the central nervous system is described in the case of a 17-year-old girl who presented with neurological symptoms in January 1986. A comparison is made with the results of computed tomography in the diagnosis of the disease, which proved to be a grade-III glioma that appeared as a lesion of the posterior fossa. The patient recovered uneventfully after radiotherapy. It is suggested that MRI should be considered seriously as a first line of investigation in any suspected lesion of the posterior fossa.     

22例不稳定骨盆骨折的内固定治疗

目的：探讨不稳定骨盆骨折治疗方法和效果。方法：22例不稳定骨盆骨折，均行切开复位内固定。结果：所有患者随访6-29个月（平均13个月），骨折均愈合，其18例功能评价为优。结论：不稳定型骨盆骨折一旦血液动力学稳定应尽早作内固定术，较保守治疗有许多优点。当前后骨盆环均有损伤时，应重点强调后方损伤的准确复位。     

Urethral polyp verumontanum

Congenital posterior urethral polyps are rare benign lesions that can cause a variety of symptoms in young boys, the diagnosis is usually made by cystourethrogram and ultrasonography where the polyp appears as a soft tissue mass arising at the base of the urinary bladder. We present a case of verumontanum polyp in a 7-year-old boy who presented to us in October 2001 with terminal hematuria, dysuria, interrupted stream and suprapubic pain. The polyp was diagnosed by ultrasonography and cystourethrogram. Transurethral resection of the polyp was performed and pathological assessment revealed a fibroepithelial lesion which is consistent with congenital posterior urethral polyp. After 18 months follow up, the patient was free of symptoms. We reviewed the literature to identify the presentation, diagnosis, treatment options and prognosis of these polyps. In the past 20 years the posterior urethral polyp has become more common than before, and it should be considered in boys with lower urinary tract dysfunction and hematuria.     

The use of diagnostic imaging in sports medicine

Imaging should only be undertaken if it is likely to influence patient management. The dose of ionising radiation to the patient should be considered. Requesting the appropriate imaging method requires an understanding of the pathological process. Plain x-ray should still generally be the first imaging technique; exceptions include some forms of superficial tendinopathy, in which ultrasound may be more appropriate, and situations where radiation exposure is contraindicated, such as in a pregnant patient. The cost of the examination to the patient and the community should also be considered (eg, ultrasound v magnetic resonance imaging).     

茶多酚对饮用塘水基因毒性的抑制作用

分别利用人和大鼠的原代肝细胞非程序ＤＮＡ合成试验，检测茶多酚对广西某肝癌高发区万世的饮用塘水浓缩物基因毒性的影响，结果发现：０．１０ｍｇ／ｍｌ的ＧＴＰ可抑制塘水浓缩物对大鼠肝细胞的ＤＮＡ的损伤，而浓度为０．０５－０．５０ｍｇ／ｍｌ的ＧＴＰ可抑制塘水浓缩物对人肝细胞ＤＮＡ的损伤，且显示出剂量－效应关系，这表明ＧＴＰ可抑制塘水存在的基因毒性物质，提示饮用绿茶对肝癌高发区的人群可能是有益的。     

Diagnosis of Lyme disease

The use of serologic testing and its value in the diagnosis of Lyme disease remain confusing and controversial for physicians, especially concerning persons who are at low risk for the disease. The approach to diagnosing Lyme disease varies depending on the probability of disease (based on endemicity and clinical findings) and the stage at which the disease may be. In patients from endemic areas, Lyme disease may be diagnosed on clinical grounds alone in the presence of erythema migrans. These patients do not require serologic testing, although it may be considered according to patient preference. When the pretest probability is moderate (e.g., in a patient from a highly or moderately endemic area who has advanced manifestations of Lyme disease), serologic testing should be performed with the complete two-step approach in which a positive or equivocal serology is followed by a more specific Western blot test. Samples drawn from patients within four weeks of disease onset are tested by Western blot technique for both immunoglobulin M and immunoglobulin G antibodies; samples drawn more than four weeks after disease onset are tested for immunoglobulin G only. Patients who show no objective signs of Lyme disease have a low probability of the disease, and serologic testing in this group should be kept to a minimum because of the high risk of false-positive results. When unexplained nonspecific systemic symptoms such as myalgia, fatigue, and paresthesias have persisted for a long time in a person from an endemic area, serologic testing should be performed with the complete two-step approach described above.