浅谈病例导入式教学在妇产科理论教学中的应用

目的:将CBS教学法运用于妇产科学的教学中,探讨其教学效果。方法:在妇产科学教学中,将我校2005级临床医学160名本科学生分为试验组(CBS教学法)和对照组(传统讲授方法)。结果:学科考试中,试验组的平均分数显著高于对照组(P<0.01)。结论:CBS教学法是行之有效并且切实可行的,对提高妇产科学的教学质量、提高学生的综合能力具有积极的意义。     

Choice of Scores in Trend Tests for Case‐Control Studies of Candidate‐Gene Associations

When applying the Cochran‐Armitage (CA) trend test for an association between a candidate allele and a disease in a case‐control study, a set of scores must be assigned to the genotypes. Sasieni (1997, Biometrics 53 , 1253–1261) suggested scores for the recessive, additive, and dominant models but did not examine their statistical properties. Using the criteria of minimizing the required sample size of the CA trend test to achieve prespecified type I and type II errors, we show that the scores given by Sasieni (1997) are optimal for the recessive and dominant models and locally optimal for the additive one. Moreover, the additive scores are shown to be locally optimal for the multiplicative model. The tests are applied to a real dataset.     

PBL联合CBL在普通外科临床见习中的应用

目的:探讨以问题为基础的教学法(problem based learning,PBL)和案例教学法(case based learning,CBL)在普通外科临床见习中的应用。方法:根据接受教学方式不同,将学生分为PBL联合CBL教学组及传统教学组,以不记名方式进行问卷调查,了解学生对PBL联合CBL教学的意见和建议,并进行统一测试评判2种方式的教学效果。结果:超过80%的学生认为PBL联合CBL教学效果显著,特别有利于提高学习效率及临床思维的培养。统一测试发现联合教学组成绩明显高于传统教学组(P0.01)。结论:PBL联合CBL是普通外科临床见习中值得推广的教学方式。     

限制性液体复苏与常规液体复苏对失血性休克患者临床疗效分析

目的:探讨限制性液体复苏与常规液体复苏对失血性休克患者死亡率、凝血功能及并发症的影响。方法:选取失血性休克患者100例,随机分为限制组(n=55)和常规组(n=45),其中限制组采用限制性液体复苏抗休克,而常规组采用常规液体复苏。比较两组患者输液量及死亡率、血压与检验指标、并发症发生率。结果:与常规组相比,限制组患者输液量较少,死亡率较低,痊愈率较高,差异有统计学意义(P0.05)。与常规组相比,限制组患者平均动脉压、碱剩余明显较低,血红蛋白、血小板、红细胞比容明显较高,凝血酶原时间明显较短,差异有统计学意义(P0.001)。与常规组相比,限制组患者急性呼吸窘迫综合征、多器官功能障碍综合征发生率较低,差异有统计学意义(P0.05)。结论:限制性液体复苏为失血性休克患者赢得更多后续急诊手术止血时间,能降低患者死亡率和并发症如急性呼吸窘迫综合征、多器官功能障碍综合征的发生率。     

Referent sampling,family history and relative risk: the role of length-biased sampling

Familial risk of disease is often assessed using case control studies based on referent databases. A referent database is a collection of family histories of cases typically assembled as a result of one family member being diagnosed with disease. This sampling scheme is equivalent to sampling families proportional to their size. The larger the family, the greater the probability of finding the family in the referent registry. This phenomena is known as length-biased sampling. The consequence of this kind of sampling is to bias the regression estimate associated with family history. The estimate is typically inflated in comparison to what is true for the actual population.     

Comparative life cycle assessment of two landfill technologies for the treatment of municipal solid waste

Goal and Scope  The potential environmental impacts associated with two landfill technologies for the treatment of municipal solid waste (MSW), the engineered landfill and the bioreactor landfill, were assessed using the life cycle assessment (LCA) tool. The system boundaries were expanded to include an external energy production function since the landfill gas collected from the bioreactor landfill can be energetically valorized into either electricity or heat; the functional unit was then defined as the stabilization of 600 000 tonnes of MSW and the production of 2.56x10⁸ MJ of electricity and 7.81x10⁸ MJ of heat. Methods  Only the life cycle stages that presented differences between the two compared options were considered in the study. The four life cycle stages considered in the study cover the landfill cell construction, the daily and closure operations, the leachate and landfill gas associated emissions and the external energy production. The temporal boundary corresponded to the stabilization of the waste and was represented by the time to produce 95% of the calculated landfill gas volume. The potential impacts were evaluated using the EDIP97 method, stopping after the characterization step. Results and Discussion  The inventory phase of the LCA showed that the engineered landfill uses 26% more natural resources and generates 81% more solid wastes throughout its life cycle than the bioreactor landfill. The evaluated impacts, essentially associated with the external energy production and the landfill gas related emissions, are on average 91% higher for the engineered landfill, since for this option 1) no energy is recovered from the landfill gas and 2) more landfill gas is released untreated after the end of the post-closure monitoring period. The valorization of the landfill gas to electricity or heat showed similar environmental profiles (1% more raw materials and 7% more solid waste for the heat option but 13% more impacts for the electricity option). Conclusion and Recommendations  The methodological choices made during this study, e.g. simplification of the systems by the exclusion of the identical life cycle stages, limit the use of the results to the comparison of the two considered options. The validity of this comparison could however be improved if the systems were placed in the larger context of municipal solid waste management and include activities such as recycling, composting and incineration.     

Regulation of the in vitro anamnestic antibody response by cyclic AMP. II. Antigen-dependent enhancement by exogenous prostaglandins of the E series.

The spleen cells from CFW/D mice injected with dimethylbenzanthracene-induced leukemia virus exhibited a progressive decline in the in vitro response to heterologous erythrocyte antigens in parallel with tumor growth. Cell transfer experiments revealed that this immunodepressed state may involve a B-cell defect rather than extrinsic factors in the cellular environment since: (i) nonresponsiveness could be transferred to irradiated non-tumor-bearing mice with spleen cells, and (ii) T cells from tumorbearing mice cooperated with normal bone marrow cells, but bone marrow from tumorbearing mice did not cooperate with normal T cells. In addition, T cells from the thymic tumor could cooperate with normal bone marrow cells upon transfer to irradiated recipients. TL 485-2 cells, a T-cell line derived from the tumor, could be specifically activated with SRBC thereby indicating that the virus transformed T cells were immunocompetent. Suppressor cells, which appeared in the spleen concomitant with immunodepression and tumor development, may directly raise B-cell thresholds for T-dependent triggering signals since the antibody response of spleen cells from tumor-bearing mice could be restored by adding agents such as LPS, 2 mercaptoethanol, or T cells exogenously preactivated in normal animals. The suppressor cell could be enriched by adherence to plastic and was removed by treatment with carbonyl iron. In addition, it was unlikely that the suppressor cell was a virus-infected cell since transformed, virus-infected cells from the tumor or TL 485-2 cells were not suppressive when added to spleen cells in vitro but rather resulted in a marked, polyclonal enhancement of the PFC response. The interaction of TL 485-2 cells and normal spleen cells resulted in the release of a stimulatory factor which increased DNA synthesis in resting cells as well as increasing PFC. The role of these enhancing factors and suppressor cells in controlling tumor growth remains to be elucidated.