Orbit: initial experience with surface coil spin-echo MR imaging at 1.5 T

Fifty-nine cases in which surface coil MR imaging of the orbit was performed were reviewed. MR imaging was performed with spin-echo techniques at 1.5 T with both short repetition time/echo time (TR/TE) and long TR/TE sequences in all cases. In all patients short TR/TE images were obtained with small-diameter surface coils; long TR/TE images were usually obtained with a standard head coil. Surface coil MR appears to be an important adjunct in state-of-the-art orbital imaging. Orbital MR imaging may be most useful, providing information not available on computed tomography (CT), in identifying lesions in the orbital apex, superior orbital fissure, and optic canal; differentiating inflammatory pseudotumor from malignancy in clinically similar patients; characterizing lesions containing hemorrhage or other paramagnetic material; defining the posterior extent of optic pathway gliomas; and detecting abnormal flow in intraorbital vascular structures. CT seems to be superior to MR imaging in the evaluation of small perioptic meningiomas, especially those that are calcified.     

Cells expressing human glucocerebrosidase from a retroviral vector repopulate macrophages and central nervous system microglia after murine bone marrow transplantation

Gaucher disease is an inherited lysosomal storage disease in which the loss in functional activity of glucocerebrosidase (GC) results in the storage of its lipid substrate in cells of the macrophage lineage. A gene therapy approach involving retroviral transduction of autologous bone marrow (BM) followed by transplantation has been recently approved for clinical trial. Amelioration of the disease symptoms may depend on the replacement of diseased macrophages with incoming cells expressing human GC; however, the processes of donor cell engraftment and vector gene expression have not been addressed at the cellular level in relevant tissues. Therefore, we undertook a comprehensive immunohistologic study of macrophage and microglia replacement after murine BM transplantation with retrovirus-marked BM. Serial quantitative PCR analyses were employed to provide an overview of the time course of engraftment of vector-marked cells in a panel of tissues. Following reconstitution of hematopoietic tissues with vector- marked donor cells at early stages, GC+ cells began to infiltrate the liver, lung, brain, and spinal cord by 3 months after transplant. Immunohistochemical analyses of PCR+ tissues using the 8E4 monoclonal antibody specific for human GC revealed that macrophages expressing human GC had partially reconstituted the Mac-1+ population in all tissues in a manner characteristic to each tissue type. In the brain, 20% of the total microglia had been replaced with donor cells expressing GC by 3 to 4 months after transplant. The finding that significant numbers of donor cells expressing a retroviral gene product immigrate to the central nervous system suggests that gene therapy for neuronopathic forms of lysosomal storage diseases as well as antiviral gene therapy for AIDS may be feasible.     

抗三尖杉酯碱HL－60细胞的抗程序性细胞死亡及其克服

三尖杉酯碱（ｈａｒｒｉｎｇｔｏｎｉｎ，ＨＴ）是中国产植物海南粗榧（ＣｅｐｈａｌｏｔａｘｕｓｈａｉｎａｎｅｎｓｉｓＬｉ）中提取的一种抗肿瘤药物，对急性粒细胞白血病、急性单核细胞白血病有较好疗效（１）。三尖杉酯碱可非常有效地诱导敏感ＨＬ－６０细胞程序性死亡（ａｐｏｐｔｏｓｉｓ，Ａｐｏ）（２，３）。但超过半致死剂量（ＩＣ５０）近百倍的ＨＴ却不能诱导抗三尖杉酯碱细胞ＨＴ１２程序性死亡。如用维拉帕米（ｖｅｒａｐａｍｉｌ，Ｖｐ）１０μｇ·ｍｌ－１逆转多药抗性后，ＨＴ虽可诱导ＨＴ１２细胞程序性死亡，但与敏感细胞相比，出现程序性细胞死亡的时间大大推迟，用药浓度也提高约１０倍。这些结果提示：程序性细胞死亡可能作为肿瘤细胞是否已形成抗药性的标志之一，同时也说明程序性细胞死亡相关因子可能参与肿瘤细胞抗药性的形成。     

Paranasal sinus hemorrhage: evaluation with MR imaging

Computed tomography (CT) and magnetic resonance (MR) imaging were performed in ten patients with paranasal sinus hemorrhage after trauma. Acute or subacute hemorrhage was detected on MR images by using T1- and T2-weighted imaging to identify the chemical state of the blood and to differentiate blood from mucosal thickening and sinus effusion. Surgical proof of intrasinus hemorrhage was obtained in only two cases. Displaced fractures, associated cerebral contusions, and traumatic encephalocele were well shown on MR imaging. Nondisplaced and minimally displaced fractures were better evaluated with CT.