低场磁共振胰胆管成像技术对胆系结石的诊断分析

目的:探讨低场磁共振胰胆管成像(MRCP)技术对胆系结石的临床诊断价值。方法:对316例胆系结石的患者采用快速自旋回波之重T2加权进行MRCP检查,经最大信号强度投影(MIP)取得影像,其中205例有手术及病理结果。结果:低场MRCP影像能较好地显示胆系结石的病变部位及梗阻程度。结论:低场开放式磁共振MRCP检查技术在胆系梗阻性疾病的诊断中定位准确、安全可靠,是一种无创伤的影像学检查方法,具有临床推广应用价值。     

胰岛素瘤动态三期增强CT和18F-FDG PET/CT影像分析

目的 探讨胰岛素瘤MSCT动态三期增强及¹⁸F-FDG PET/CT显像的影像学特点。方法 回顾性分析我院6例经手术病理证实的胰岛素瘤的临床资料和¹⁸F-FDG PET/CT及同机MSCT动态三期增强影像资料。结果 6例患者均有不同程度低血糖发作病史和典型的惠普尔三联征,其中2例以精神症状首诊。全部病例空腹或发作时血糖均<2.8 mmol/L,胰岛素释放指数均>0.3。6例胰岛素瘤均为单发,1例位于胰尾,2例位于胰体,3例位于胰头,肿瘤直径0.8 cm×0.9 cm~3.0 cm×3.8 cm,平均1.6 cm×1.6 cm。CT平扫肿瘤呈均匀等或稍低密度,边界不清;增强扫描动脉期呈明显均匀强化,静脉期及延迟期强化程度逐渐减低,动脉期强化最为显著。6例患者中,5例肿瘤局部¹⁸F-FDG摄取未见增高,1例多发性内分泌肿瘤1型(MEN 1)相关胰岛素瘤局部¹⁸F-FDG摄取增高,SUV_max＝4.8。结论 MSCT动态三期增强扫描可清晰显示肿瘤的形态和位置,¹⁸F-FDG PET/CT对本病诊断价值有限。     

心脏冠状动脉多排CT临床应用专家共识

多排CT(multi-detector computed tomography,MDCT)近5年来发展极为迅速.2004年底全球首次推出64排CT,并迅速应用于临床心脏和冠状动脉成像,目前在诊断和排查冠心病方面已经成为临床重要的无创影像检查手段.     

Immune pathogenesis of pediatric HIV-1 infection

Vertical exposure to HIV occurs at a time when functional capacity of the infant‘s immune system is attenuated through immaturity. Immune response capability is rooted in host genetic makeup, and the broad and fine specificity of innate and adaptive immune responses, respectively, shape the outcomes of HIV encounter in some instances and imprint viral changes through selective immune pressure in others. Findings from recent studies have profound implications for understanding immune pathogenesis of pediatric HIV infection and, in particular, highlight the importance of host genetics of both mother and child in determining whether an exposed child acquires HIV infection or not and, if infected, the rate of disease progression. This review focuses on the key host molecules, the CC chemokine CCL3 and HLA, which have taken center stage in these new developments.     

Gamma interferon production in response to Mycobacterium bovis BCG and Mycobacterium tuberculosis antigens in infants born to human immunodeficiency virus-infected mothers

In utero sensitization to infectious pathogens can establish immunological memory and may influence the immune response to unrelated antigens. Little is known about the influence of intrauterine human immunodeficiency virus (HIV) exposure on the cellular immune response to mycobacterial antigens. Whole-blood culture gamma interferon (IFN-gamma) production in response to mycobacterial antigens was measured at birth and 6 weeks of age to determine the characteristics of the IFN-gamma response in HIV-exposed infants to Mycobacterium bovis BCG and mycobacterial antigens. At birth, we observed an increased immune activation in response to phytohemagglutinin among HIV-exposed, uninfected infants. In a proportion of these infants, we also observed an increased immune activation in response to purified protein derivative, BCG, and early secreted antigen target 6. Increases in the IFN-gamma response to the four antigens between birth and 6 weeks of age, observed in all HIV-unexposed infants, was absent in a substantial proportion of HIV-exposed, uninfected infants. The immunological differences persisted at 6 weeks of age, suggesting a sustained impact of in utero immune priming by HIV. Intrauterine exposure to HIV affects the infants' cellular immune response to mycobacterial antigens, either specifically or as a consequence of nonspecific, broadly reactive immune activation. Further studies will be important to help determine optimal vaccination and disease prevention strategies for this vulnerable population group.     

CT仿真内镜对鼻腔及鼻窦临床应用价值的研究

目的：探讨CT仿真内镜对鼻腔及鼻窦病变的显示能力和临床应用价值。方法：搜集健康志愿者6例及临床疑为鼻部病变的患者30例共71例鼻腔，分别进行CT仿真内镜及硬管内镜检查，将两种方法所得显示结果进行对比研究，并利用Wilconxon Wtest和x^2进行统计分析。结果：对鼻腔解剖结构和病变的显示，VE与RE有良好的一致性，VE可完整显示大部分未受侵犯的结构及大的病变；VE较RE能更清楚完整地显示鼻窦肿瘤、囊肿和息肉，本组显示例数均多于RE。结论：VE具有操作简便、无生、多入路方式及多观察方向的特点。对鼻腔病变的诊断上，VE可作为一种补充手段；对鼻窦病变的诊断，VE有一定优势，可作为一种主要手段运用于临床。     

胸腺瘤的CT观察

５２例经病理学证实的胸腺瘤ＣＴ资料表明，胸腺瘤主要以直接延伸的方式生长，部分胸腺瘤可由近及远地侵犯纵隔诸间隙或（和）类似胸膜间皮瘤一样沿胸膜、心包呈侵袭性生长，只有极少的胸腺瘤可经血行或淋巴途径向远处转移，据此，我们将胸腺瘤分为局限性胸腺瘤与非局限性胸腺瘤两类，这种分类反映了胸腺瘤生长延伸的生物学特性，诊断标准易于掌握，对指导治疗方针的制订及预后的估计有重要的参考作用。     

急性胰腺炎MRI诊断

目的 探讨MRI在急性胰腺炎中的诊断价值。方法 选择经临床确诊的急性胰腺炎20例。男14例，女6例，平均年龄41.4岁。20例中轻度型15例，重度型5例，使用1.5T超导MRI扫描仪，SE序列常规T1WI和T2WI横断和冠状面成像；MRCP使用2D、HASTE加脂肪抑。结果 MRI主要显示胰腺信号不均匀或假囊肿形成；MRCP主要显示胰胆管扩张、狭窄或宽窄不一，严重的胰胆近呈囊肿扩张。结论 MRI尤其T2WI能清楚显示胰腺胆管的狭窄、扩张及腔内缺损等表现，一般能作出急性胰腺炎、轻重程度及病因的诊断。     

CT导引下胸内肿物穿刺活检22例临床分析

目的探讨CT导引下的胸壁穿刺活检对胸内占位性病变的诊断价值。方法对22例行CT导引下胸壁穿刺活检的病例进行总结分析,该组患者均为CT扫描发现胸部肿物而难以明确诊断者。结果所有病例均穿刺成功并获组织学和细胞学材料,送检共发现19例为恶性病变;组织学诊断有18例为恶性病变,细胞学诊断有5例为恶性病变。穿刺中和穿刺后,发生气胸2例、痰中带血1例。结论CT导引下的胸壁穿刺活检是一种有效的诊断手段,自动切割针可以较好地获得组织学标本,细胞学和组织学检查互补可提高检出率。     

Evaluation of the HIV-1 Polymerase Gene Sequence Diversity for Prediction of Recent HIV-1 Infections Using Shannon Entropy Analysis

HIV-1 incidence is an important parameter for assessing the impact of HIV-1 interventions. The aim of this study was to evaluate HIV-1 polymerase (pol) gene sequence diversity for the prediction of recent HIV-1 infections. Complete pol Sanger sequences obtained from 45 participants confirmed to have recent or chronic HIV-1 infection were used. Shannon entropy was calculated for amino acid (aa) sequences for the entire pol and for sliding windows consisting of 50 aa each. Entropy scores for the complete HIV-1 pol were significantly higher in chronic compared to recent HIV-1 infections (p < 0.0001) and the same pattern was observed for some sliding windows (p-values ranging from 0.011 to <0.001), leading to the identification of some aa mutations that could discriminate between recent and chronic infection. Different aa mutation groups were assessed for predicting recent infection and their performance ranged from 64.3% to 100% but had a high false recency rate (FRR), which was decreased to 19.4% when another amino acid mutation (M456) was included in the analysis. The pol-based molecular method identified in this study would not be ideal for use on its own due to high FRR; however, this method could be considered for complementing existing serological assays to further reduce FRR.