沉默树突状细胞恒定链以增强其抗肿瘤作用的体外实验研究

目的初步观察用小分子干扰RNA(siRNA)沉默树突状细胞(DCs)恒定链(Ii)后,DCs疫苗的体外抗肿瘤效果。方法从小鼠骨髓分离骨髓前体细胞,细胞经100 ng/ml GM-CSF和100 ng/ml IL-4诱导培养6 d后,转染针对DCs Ii链特异的Ii-siRNA,转染后加用50 ng/ml TNF-α继续诱导细胞成熟48 h,然后分别用Western blot检测沉默效果及CCK-8试剂盒检测DCs刺激同种异体淋巴细胞增殖的能力;此外,DCs共转染Ii-siRNA和小鼠胃癌前体细胞MFC的总RNA后,与同种异体淋巴细胞共培养,通过ELISA检测培养上清IFN-γ/和IL-4的水平,并收集致敏淋巴细胞进行体外杀伤实验。结果Ii-siRNA明显抑制DCs Ii的表达。沉默Ii链能够增强DCs的淋巴细胞增殖能力,并促使淋巴细胞向Th1的方向漂移[IFN-γ:(5107±351)pg/ml,IL-4:(65±13)pg/ml,P＜0．05]。淋巴细胞经共转染Ii-siRNA和MFC RNA的DCs激活后,明显而特异地杀伤靶肿瘤细胞(杀伤百分率: 66．94%±2．75%,P＜0．05)。结论通过siRNA沉默DCs的Ii链可能是一种行之有效的增强抗肿瘤免疫的方法。     

Adhäsionsmoleküle in der Dermatoonkologie

Zusammenfassung Adh?sionsmoleküle sind Zell-Oberfl?chen-Proteine, welche verantwortlich sind für die Zell-Zell- und Zell-Matrix-Interaktionen. Sie sind in der Lage eine gro?e Zahl von Stimuli zu erkennen und darauf entsprechend zu reagieren. Sie bilden somit eine Basis für manchen physiologischen und pathologischen Prozess insbesonders des „Homing“-Verhaltens, der Homeostase der Immunantwort, der Wundheilung, der Entzündungen und der Tumormetastasierung. In der Dermatologie wurde das Interesse vor allem durch die Entdeckung des CLA (cutaneous lymphocyte antigen) geweckt, welches der spezifische „Homing“-Rezeptor für Memory-T-Zellen darstellt. So konnte gezeigt werden, da? die Zellen in kutanen Lymphomen CLA-positive T-Zellen sind, im Gegensatz zu prim?r nodalen Non-Hodgkin Lymphomen, wo die T-Zellen CLA negativ sind. Neuere Arbeiten haben gezeigt, da? die Adh?sionsmoleküle wie CD44v6 bei kutanen Lymphomen, welche eine systemische Ausbreitung zeigen, auf den Tumorzellen exprimiert werden und somit eine entscheidende Rolle in der Metastasierung dieser Tumoren darstellen. Eingegangen am 27. November 1995 Angenommen am 22. Dezember 1995     

Stereotactic brain biopsy in AIDS

Summary In the hope of finding a treatable condition, the need for rapid diagnosis in HIV-seropositive patients with brain lesions is apparent. In order to evaluate the efficacy of stereotactic brain biopsy in AIDS patients, we retrospectively studied 25 HIV-infected patients undergoing stereotactic biopsy. Brain lesions were identified with gadolinium-enhanced MRI and/or contrastCT. Brain biopsy was performed using the system of Riechert. From 8 up to 15 small tissue samples from one or two targets were obtained in every patient. The biopsy material was examined cytologically, histologically (including electron microscopy), immunohistochemically and, in part, by animal test and polymerase chain reaction (PCR). A definite diagnosis was achieved in 92%. Diagnosis included primary central nervous system lymphoma (PCNSL) (10), toxoplasmosis (10), progressive multifocal leukoencephalopathy (2) and one case of co-existing toxoplasmosis and cytomegalovirus infection. Two biopsies were non-diagnostic. All PCNSLs showed polymorphic B-cell populations of high malignancy; accurate classification according to the Kiel classification was not possible. In 3 lymphomas Epstein-Barr nuclear antigen (EBNA) 2-mRNA could be detected by PCR and confirmed immunohistochemically by EBNA 2 expression. In 6 cases autopsy confirmed the biopsy diagnosis. Conventional histology was not sufficiently decisive for toxoplasmosis and progressive multifocal leukoencephalopathy, so that immunohistochemistry and animal tests became very important for a final diagnosis. With the help of different morphological and molecular biological techniques stereotactic brain biopsy appears to be an effective method in the diagnosis of HIV-associated brain lesions. In view of the marked radio- and chemosensitivity of PCNSLs it is mandatory to establish an early and accurate histological diagnosis for adequate treatment.     

Ultrasound-guided Lumbar Facet Nerve Block: Accuracy of a New Technique Confirmed by Computed Tomography

Background: Lumbar facet nerve (medial branch) blocks are often used to diagnose facet joint-mediated pain. The authors recently described a new ultrasound-guided methodology. The current study determines its accuracy using computed tomography scan controls.

Methods: Fifty bilateral ultrasound-guided approaches to the lumbar facet nerves were performed in five embalmed cadavers. The target point was the groove at the cephalad margin of the transverse (or costal) process L1-L5 (medial branch T12-L4) adjacent to the superior articular process. Axial transverse computed tomography scans, with and without 1 ml contrast dye, followed to evaluate needle positions and spread of contrast medium.

Results: Forty-five of 50 needle tips were located at the exact target point. The remaining 5 were within 5 mm of the target. In 47 of 50 cases, the applied contrast dye reached the groove where the nerve is located, corresponding to a simulated block success rate of 94% (95% confidence interval, 84-98%). Seven of 50 cases showed paraforaminal spread, 5 of 50 showed epidural spread, and 2 of 50 showed intravascular spread. Despite the aberrant distribution, all of these approaches were successful, as indicated by contrast dye at the target point. Abnormal contrast spread was equally distributed among all lumbar levels. Contrast traces along the needle channels were frequently observed.     

Biexponential diffusion tensor analysis of human brain diffusion data.

Several studies have shown that in tissues over an extended range of b-factors, the signal decay deviates significantly from the basic monoexponential model. The true nature of this departure has to date not been identified. For the current study, line scan diffusion images of brain suitable for biexponential diffusion tensor analysis were acquired in normal subjects on a clinical MR system. For each of six noncollinear directions, 32 images with b-factors ranging from 5 to 5000 s/mm2 were collected. Biexponential fits yielded parameter maps for a fast and a slow diffusion component. A subset of the diffusion data, consisting of the images obtained at the conventional range of b-factors between 5 and 972 s/mm2, was used for monoexponential diffusion tensor analysis. Fractional anisotropy (FA) of the fast-diffusion component and the monoexponential fit exhibited no significant difference. FA of the slow-diffusion biexponential component was significantly higher, particularly in areas of lower fiber density. The principal diffusion directions for the two biexponential components and the monoexponential solution were largely the same and in agreement with known fiber tracts. The second and third diffusion eigenvector directions also appeared to be aligned, but they exhibited significant deviations in localized areas.     

Expanded trans-pedicular spongiosa grafting--dorsal approach to filling of the intervertebral spaces with cancellous bone

Internal fixation of dorsolumbar spinal fractures can be accomplished by dorsal plating or internal fixator. So far, the technique of transpedicular grafting has been applied to fill the vertebral body with cancellous bone. In this paper, we present a new technique of extended transpedicular bone grafting to fill the intervertebral space also. By this means, the disadvantage of secondary loss of height after removal of the metal implants can be prevented.