靶向给药系统——甲氨蝶呤肝动脉栓塞微球特征及其对大鼠肝癌的实验治疗

本文介绍用乳化—冻凝技术制备甲氨蝶吟—明胶微球的方法。实验结果证实,包裹在微球内的MTX对⁶⁰钻幅射、温度和光照射是稳定的。微球的体外溶出试验、明胶微球在介质中不同时间的溶胀度试验也在文中介绍。微球肝动脉栓塞实验治疗用大鼠移植性肝癌进行,结果表明MTX微球治疗组的大鼠在肿瘤抑制率、促使肿瘤坏死程度以及延长荷瘤动物存活期方面比肝动脉灌注生理盐水、MTX溶液和明胶微球为佳.由于MTX微球具有阻断肿瘤血供和在其局部缓释化疗药物等双重功用,故治疗肝癌的效果明显优于动脉化疗或单纯栓塞方法。     

Visual pathways for object-oriented action and object recognition: functional anatomy with PET

The purpose of this study was to identify the functional anatomy of the mechanisms involved in visually guided prehension and in object recognition in humans. The cerebral blood flow of seven subjects was investigated by positron emission tomography. Three conditions were performed using the same set of stimuli. In the 'grasping' condition, subjects were instructed to accurately grasp the objects. In the 'matching' condition, subjects were requested to compare the shape of the presented object with that of the previous one. In the 'pointing' condition (control), subjects pointed towards the objects. The comparison between grasping and pointing showed a regional cerebral blood flow (rCBF) increase in the anterior part of the inferior parietal cortex and part of the posterior parietal cortex. The comparison between grasping and matching showed an rCBF increase in the cerebellum, the left frontal cortex around the central sulcus, the mesial frontal cortex and the left inferior parietal cortex. Finally, the comparison between matching and pointing showed an rCBF increase in the right temporal cortex and the right posterior parietal cortex. Thus object-oriented action and object recognition activate a common posterior parietal area, suggesting that some kind of within-object spatial analysis was processed by this area whatever the goal of the task.      

Basic fibroblast growth factor prolongs the proliferation of rat cortical progenitor cells in vitro without altering their cell cycle parameters

Basic fibroblast growth factor (bFGF) has been shown to influence the survival, proliferation and differentiation of a variety of cell types in the nervous system. In this investigation we have examined the action of bFGF on: (i) the rate of proliferation; (ii) cell cycle parameters; (iii) the maintenance of cell division; (iv) the recruitment of quiescent cells; and (v) the degree of differentiation of cortical progenitor cells in cultures prepared from E16 rat embryos. The proliferation rate (labelling index) of cortical progenitor cells doubled in the presence of bFGF over 48 h. However, the lengths of the cell cycle phases were unchanged. Clones marked with a recombinant retrovirus on the first day in vitro (DIV) grew significantly larger in the presence of bFGF. Furthermore, many of the clones examined in control cultures had ceased to divide after a maximum of four cell cycles, whereas almost all clonally related cells were still dividing in the presence of bFGF 4 days later, i.e. for at least six cell cycles. Basic FGF also stimulated the division of quiescent progenitor cells, which otherwise would have differentiated or undergone cell death. The degree of neuronal and glial differentiation was studied after 5 DIV using MAP-2 and GFAP immunocytochemistry. In the presence of bFGF, the percentage of MAP-2-labelled cells was less than half that of control cultures, whereas the number of cells immunoreactive for nestin (a marker of progenitor cells) remained very high. Cells immunoreactive for GFAP were present in bFGF-treated cultures, yet were extremely rare in control conditions. These experiments show that bFGF, a potent mitogen for cortical progenitor cells, has no effects on the parameters of their cell cycle but extends their proliferative capability, promotes their survival and delays their differentiation into neurons.      

Adnexal masses: MR imaging observations at 1.5 T, with US and CT correlation

To assess the role of 1.5-T magnetic resonance (MR) imaging in evaluation of the adnexa, 43 consecutive examinations that revealed 61 adnexal masses were retrospectively reviewed. T1- and T2-weighted images in coronal, axial, and/or sagittal planes were included. Available ultrasound (US) (n = 30) and/or computed tomographic (CT) (n = 9) scans were then correlated with the MR images. On T2-weighted images at least part of all adnexal masses was of higher signal intensity than surrounding muscle and adipose tissue, and therefore the adnexal masses were best seen with these sequences. T1-weighted imaging improved tissue characterization by revealing signal characteristics of fat in teratomas and characteristics of blood in endometriomas or hemorrhagic cysts, pelvic inflammatory disease, ovarian carcinomas, serous cystadenomas, and teratomas. MR imaging provided additional information or increased diagnostic confidence in 25 of 30 patients who underwent US or CT. MR imaging is a promising problem-solving modality after US in the study of adnexal abnormalities.     

Bacterial renal infection: role of CT

The imaging studies done on 62 patients hospitalized for acute renal infections were retrospectively reviewed. Thirty-six (58%) had one or more abscesses, 17 (27%) had focal or diffuse acute bacterial nephritis, five (8%) had pyonephrosis, and four (6%) had pyelonephritis. All had prolonged fever (greater than or equal to 72 hours) and leukocytosis. Among 25 patients examined with both ultrasound (US) and computed tomography (CT), US failed to depict three of five (60%) cases of acute bacterial nephritis and seven of 15 (47%) intrarenal and extrarenal abscesses. One renal abscess was misdiagnosed as a tumor at CT. US is not an adequate screening test for detecting lesions that may require invasive therapy. CT is more sensitive for the detection of acute renal inflammatory disease and for defining the extent of disease for planning of radiologic or surgical intervention.     

Hilar cholangiocarcinoma: comparative study with sonography and CT

Fifty-one patients were studied to determine the relative accuracy of sonography and computed tomography (CT) in the evaluation of hilar cholangiocarcinoma. Both sonography and CT permitted detection of intrahepatic bile duct dilatation in all patients. Nonunion of right and left intrahepatic bile ducts was identified with sonography in 90% and with CT in 94% of patients. The tumor per se was depicted by sonography in 21% and by CT in 40% of patients. Forty tumors (78%) were of the infiltrating type, seven (14%) were exophytic, and four (8%) were polypoid. With sonography, infiltrating and exophytic tumors were difficult to depict, whereas polypoid tumors were well identified. With CT, infiltrating tumors were more difficult to depict than were exophytic or polypoid tumors. On CT scans, depicted tumors of the infiltrating type showed high attenuation and an indistinct margin, whereas exophytic and polypoid tumors showed low attenuation and a well-defined margin. Sonography and CT were comparably accurate in determining the level of obstruction in hilar cholangiocarcinoma even when no mass was depicted. CT was superior to sonography in depicting tumor per se and in demonstrating associated findings.     

Lobular carcinoma in situ of the breast: mammographic features

Lobular carcinoma in situ (lobular neoplasia; LCIS) of the breast is most commonly an incidental microscopic finding in breast tissue removed for some other reason. The authors reviewed the clinical and mammographic features and surgical findings in 26 cases of LCIS not associated with other breast abnormalities. In 16 instances, needle localization was performed before removal of the tissue, which yielded LCIS on histologic examination. Calcifications were the most common reason for biopsy, although there were no distinctive mammographic features of LCIS.     

Osteoid osteoma of the elbow

Six cases of osteoid osteoma of the elbow were reviewed to determine the spectrum of clinical, pathologic and radiologic findings. Since osteoid osteoma of the elbow may masquerade as a nonspecific synovitis, the diagnosis is challenging and frequently delayed. The histology is, however, indistinguishable from that of osteoid osteoma occurring in typical locations. The radiologic features of osteoid osteoma of the elbow include the following triad: (a) osteosclerosis, usually a dominant feature at initial imaging and typically enveloping the nidus; (b) joint effusion; and (c) periosteal reaction that can involve both the bone in which the osteoid osteoma arises and adjacent bones. Awareness of these features will facilitate correct diagnosis, thereby facilitating timely and appropriate treatment.The opinions and assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army, the Department of Defense or the Uniformed Services University of the Health Sciences