Hyaline cartilage-origin bone and soft-tissue neoplasms: MR appearance and histologic correlation

Magnetic resonance (MR) images and histologic studies of 16 chondroid-matrix lesions were reviewed to determine if any distinctive morphologic or signal features might be discerned. Ten biopsy-proved nonchondroid bone lesions were compared in terms of configuration and signal characteristics. The tumor matrix had a distinctive appearance of homogeneous high signal intensity in a defined lobular configuration on images of all hyaline cartilage lesions obtained with a long repetition time and a long echo time. The areas of hyperintensity relative to muscle corresponded to areas of hyaline cartilage matrix with its uniform composition, low cellularity, and high water content; the lobular morphologic characteristic had an identical histologic correlate. The chondroblastomas, clear-cell chondrosarcoma, and synovial chondromatosis demonstrated a much more cellular stroma, with only scattered islands of chondroid matrix, and were isointense or hypointense compared with muscle on all MR sequences. The distinctive lobular, high-intensity MR appearance was not seen in the ten nonchondroid bone lesions.     

Avascular necrosis versus other diseases of the hip: sensitivity of MR imaging

Magnetic resonance (MR) imaging of the hip has been useful in the examination of patients for the presence of avascular necrosis (AVN). In the detection of AVN, MR imaging is more sensitive than computed tomography or nuclear scintigraphy. This study assessed the usefulness of MR imaging in the differentiation of AVN from other hip diseases. Twenty-two cases of non-AVN hip disease were matched with 23 biopsy-proved cases of AVN and ten normal controls. MR images were rated in a blinded manner by five experienced radiologists, and receiver operating characteristic (ROC) analysis was performed on the data. In the discrimination of AVN from other hip diseases or from normality, the A(z) value (the area under the ROC curve) was 98.6. With a specificity of 98%, MR imaging was 97% sensitive in the differentiation of AVN from normality, 85% sensitive in the differentiation of AVN from non-AVN disease, and 91% sensitive in the differentiation of AVN from both conditions. MR imaging may therefore help discriminate between AVN and other hip diseases.     

老年痴呆症药物石杉碱甲的类似物研究Ⅱ(±)-失二碳石杉碱甲类似物的合成

石衫碱甲(1)是从中草药干层塔中提取分离到的一种高效可逆的乙酰胆碱酯酶抑制剂,经临床试验证实对老年痴呆症有显著疗效。本文报道保持石杉碱甲分子基本骨架,失二个甲基类似物7和8的合成。β-酮酯2和丙烯醛发生Michael-Aldol反应得直立键和平伏键的羟基化合物9和10,其相应的甲磺酸酯11和12分别在丙二酸钠和醋酸中130℃回流,直立键甲磺酸酯11发生消去反应得需要的环内双键中间体13,而平伏键甲磺酸酯12则发生SN₂取代反应得直立键醋酸酯14。基于全合成路线,合成了失二碳石杉碱甲类似物7和8,其乙酰胆碱酯酶抑制活性均低于天然石杉碱甲。     

Alzheimer氏病的细胞支架病理学

<正> A1zheimer氏病(AD)与肌萎缩侧索硬化症类似,以脑内特定的神经细胞簇内的细胞支架发生病理改变为其特点。一、神经原纤维缠结(neurofibrillaryangles; NFT):用浸银方法,组化染色及免疫细胞化学技术可显示在不同脑神经元核周的NFT,包括蓝斑、背缝核、前脑基底部胆硷能系统、杏仁核。海马和新皮层。NFT的主要成份是10nm的双股螺旋微丝(pairedhelical filaments; PHF),可能混有10nm的神经微丝和15nm的直微丝,PHF在微丝病理学中最具特色,是不溶性的交链聚合体,可能大部分由神经蛋白组成。另外,非     

NADPH production by the malarial parasite Plasmodium falciparum

Two enzymes from Plasmodium falciparum that catalyze the formation of NADPH have been partially purified and characterized. Glutamate dehydrogenase (GDH), molecular mass 230 Kd, pH optimum 7.0, is capable of producing NADPH under optimum conditions at about 10% of the capacity of the host erythrocyte. This capacity increases slightly during the developmental cycle of the parasite. NADP-specific isocitrate dehydrogenase (IDH), molecular mass 80 Kd, pH optimum 7.5, is capable of producing NADPH at 20% to 60% of the capacity of the host cell, depending on the developmental stage of the parasite. Increasing IDH activity is observed as the parasite matures. GDH and IDH provide the parasite with NADPH-generating abilities that compare favorably with the host cell.     

Lipid accumulation and production of colony-stimulating activity by the 266AD cell line derived from mouse bone marrow

The availability of cloned lines of bone marrow stromal cells could facilitate the analysis of their role in hemopoietic cell development. The 266AD cell line was isolated from a colony of lipid-accumulating bone marrow cells growing in a collagen gel. 266AD cells have subsequently been maintained by passage in tissue culture plastic flasks about every 10 days for greater than 10 mo. Subconfluent cultures of cells are fibroblast-appearing, but in confluent cell sheets, prominent foci of lipid-containing cells develop in both uncloned and four separate cloned cell lines. Supernatants from confluent cultures containing lipid-laden cells contain granulocyte- macrophage colony-stimulating activity (GM-CSA) for normal bone marrow cells and can induce differentiation of Abelson virus transformed murine promonocytic leukemia cells. 266AD cells were originally isolated in the presence of hydrocortisone, but hydrocortisone is not necessary for lipogenesis to occur. Growth of bone marrow cells in a collagen gel matrix provided a way to isolate stromal cells, and the 266AD cell line provides a means to examine the relationships between stromal cell lipogenesis and regulation of granulopoiesis.     

Positron emission tomographic measurement of bone marrow blood flow to the pelvis and lumbar vertebrae in young normal adults [published erratum appears in Blood 1994 Nov 15;84(10):3602]

Ten young normal adults had pelvic and lumbar vertebral body bone marrow blood flow examined using [15O]water and positron emission tomography (PET) in a study designed to assess the feasibility and reproducibility of the PET technique for measuring marrow blood flow to various marrow regions. The procedure was well tolerated. Repeated blood flow measurements obtained from two consecutive [15O]water exams on each individual subject were highly reproducible. In addition, there was minimal variation in marrow blood flow from individual to individual and no gender differences were noted. In contrast, mean +/- SD bone marrow blood flows (expressed as milliliters per minute per 100 g) at selected anatomical sites were significantly different and were as follows: lower lumbar vertebral bodies, 17.6 +/- 3.1; most posterior and superior pelvis (conventional site of percutaneous bone marrow biopsy), 14.3 +/- 3.1; and total superior pelvis, 11.1 +/- 2.0. We conclude that PET is a relatively noninvasive, simple, and reproducible technique for measuring bone marrow blood flow. Marrow blood flow is consistent between normal young subjects, but varies significantly between different anatomic regions of the marrow.