胰腺癌可切除性的CT研究

４３例胰腺癌均经手术和／或病理证实，其中１０例经胰十二指肠切除术切除。本文复习ＣＴ所见，初步认为下列表现是胰腺癌不可切除的ＣＴ征象：（１）胰头癌距肝门的距离少于４ｃｍ；（２）肠系膜上动脉、下腔静脉、腹主动脉、胃、肝、脾、左肾及较大范围的肠系膜上静脉浸润；（３）肝转移。腹水、肠系膜上动脉周围脂层的单纯消失均不是判断不可切除的可靠征象。     

Early sexual initiation: the role of peer norms

OBJECTIVE: To elucidate which components of peer norms influence the process of sexual initiation for young adolescents. Design. Prospective cohort study. Setting. Fourteen elementary and middle schools in an urban public school district. Participants. The 1389 sixth-grade students who completed the questionnaire at the beginning (time 1) and at the end (time 2) of the school year comprise the study sample. Mean age at time 1 was 11.7 years. RESULTS: Of students entering the sixth grade, 30% (n = 416) reported having already initiated sexual intercourse, 5% (n = 74) reported initiating sexual intercourse during the sixth-grade school year (initiated group), and 63% (n = 873) reported not having initiated sexual intercourse by the end of the sixth-grade school year (never group). Demographic comparisons revealed that students in the initiated group were significantly more likely than students in the never group to be older (11.9 years vs 11.6 years), male (58% vs 37%), African-American (70% vs 51%), attending a poorer school (87% vs 85%), and living in an area with a high proportion of single-parent families (45% vs 41%). Self-reports and reports of peers' participation in nonsexual risk behaviors were more common for students in the initiated group. Students in the initiated group were more likely than students in the never group to perceive: 1) a high prevalence of sexual initiation among peers; 2) social gains associated with early sexual intercourse; and 3) younger age of peers' sexual initiation. Students in the never group were more likely to believe that sexually-experienced 12-year-old boys would be negatively stigmatized compared with students in the initiated group. Three predictive models were developed to test the relationship between peer norms and the process of initiation. These models demonstrate that the strongest predictor of sexual initiation in sixth grade is having high intention to do so at the beginning of sixth grade. The strongest predictor of high intention is belief that most friends have already had sexual intercourse. Perceptions of social gain and stigma for sexually-experienced 12-year-old boys act independently of intention to decrease risk of early sexual initiation. CONCLUSION: Early sexual intercourse is not an unplanned experience for many teens. Decisions about initiation are strongly bound to social context with peers playing an important role in creating a sense of normative behavior. Specific components of peer norms impact the process of sexual initiation in both positive and negative ways. Interventions aimed at delaying the onset of sexual initiation need to focus on cohort norms as well as on an individual's perceptions and behaviors.     

外伤性脑梗死的CT诊断(附39例分析)

目的：探讨螺旋CT在外伤性脑梗死诊断中的价值及其特征。方法：对39例头颈部外伤后临床主要表现为不同程度的偏瘫患者行横断面螺旋CT扫描，分析外伤性脑梗死的CT表现。结果：根据临床和CT表现分为两型：I型(21例)，外伤性腔隙性脑梗死，好发于基底节-内囊区，均位于豆状核、尾状核及内囊区，呈小片状腔隙性低密度区；Ⅱ型(18例)，外伤性大面积脑梗死，为脑叶梗死呈扇形低密度区，与大脑前中后供血动脉或颈内动脉分布一致，范围较大。结论：螺旋CT扫描检查对外伤性脑梗死的准确诊断、估计病变程度，分析两型脑梗死的不同发生机制，为临床诊断、治疗及判断预后提供重要信息。     

带红系增强子的人β珠蛋白基因在转基因小鼠中的表达

带红系增强子的人β珠蛋白基因在转基因小鼠中的表达李政刘德培刘庆辉郭志晨章秋珩李志杰贾佩臣梁植权β４１／４２是印度次大陆、东南亚及我国南方常见的一种血红蛋白病，纯合子呈严重的β－地中海贫血。本实验旨在建立带红系，增强子５′ＨＳ２的人β４１／４２珠蛋白基...     

少见胸腺肿瘤及肿瘤样病变的CT表现

目的：探讨少见胸腺肿瘤及肿瘤样病变的CT表现。方法：搜集8例经病理证实的少见胸腺肿瘤及肿瘤样病变，与病理结果对照，结合献分析CT表现。结果：8例中淋巴瘤3例，畸胎瘤2例，囊肿2例，脂肪瘤1例。结论：CT检查对少见胸腺肿瘤及肿瘤样病变有较大价值，部分病变可确诊。     

肾脏嗜酸细胞瘤的CT诊断

分析肾嗜酸细胞瘤的ＣＴ表现及其病理基础，以提高对此瘤的认识。材料与方法：２例肾嗜酸细胞瘤经病理诊断，术前均行ＣＴ平扫及增强扫描。结果；２例为单发肿瘤，直径为４．８ｃｍ及５．０ｃｍ。     

四种弥漫性胸膜疾病CT影像特征

本文分析了恶性胸膜间皮瘤、胸膜转移瘤、脓胸、纤维胸等四种胸膜弥漫性疾病（共６３例，其中恶性病变３９例，良性病变２４例）的ＣＴ特征。结节性增厚、壁层胸膜厚度大于１ｃｍ及纵隔胸膜受累、肺门和纵隔淋巴结受累多见于恶性病变，其特异性分别为９６％、８７％、７９％和１００％。敏感性分别为６２％、３３％、３８％和３３％。胸膜线状粘连增厚和钙化多提示良性病变，其特异性分别为９２％和１００％，敏感性均为４６％。     

Isolation of an abnormal protein C molecule from the plasma of a patient with thrombotic diathesis

Protein C has been purified from the plasma of a patient with thrombotic diathesis. Both before and after isolation, the protein showed reduced capacity to hydrolyze synthetic substrates and to anticoagulate plasma. Proteolysis with the soluble thrombin- thrombomodulin complex proceeded normally and to completion as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. Approximately one-third of the protein is functional, indicating a heterozygous defect. Indirect studies suggest that the abnormal component can bind to protein S and phospholipids. Both forms of activated protein C can also incorporate radiolabeled diisopropylfluorophosphate.