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991.
The characteristic features of hamartoma in terms of discrepancies in mammographic and sonographic shapes of the mass were evaluated. We reviewed 16 pathologically proven breast hamartomas, which had undergone preoperative mammography and ultrasonography. All masses were analyzed according to ACR-BIRADS on mammography. On sonography, each mass was analyzed for size, shape, margin, internal echogenicity, and posterior acoustic enhancement. We also analyzed the echogenicity of halo, and compared the characteristic changes in the shape of hamartomas attributable to compression in mammograms and sonograms. The most common sites were at 12 o'clock in the right breast and 2 o'clock in the left. The most common mammographic findings of the hamartomas were a round shape (11/16), a circumscribed margin (13/16), internal fat densities (D4)(16/16) and radiolucent halos (14/16). The most common sonographic findings of the hamartomas were an oval shape (16/16), circumscribed margins (10/16), heterogeneous internal echogenicity (14/16), echogenic (7/16) or echolucent halos (5/16), and posterior enhancements (12/16). The characteristic feature of hamartomas was a change of the mammographic round shape mass into an elongated oval shape mass by sonography (11/11), suggesting the compressibility of hamartomas. Three of the hamartomas contained a pathologically proven internal calcification. The presence of a hamartoma was suggested by a change in a mammographic round mass with a radiolucent halo into an oval heterogeneous mass surrounded by an echogenic or echolucent halo on the sonogram. This characteristic difference between the mammographic and sonographic findings was attributed to the hamartoma compressibility, and was associated with the over-proliferation of fat containing mature normal breast tissue. 相似文献
992.
Rohner D Hutmacher DW Cheng TK Oberholzer M Hammer B 《Journal of biomedical materials research. Part B, Applied biomaterials》2003,66(2):574-580
Alloplastic materials offer a number of advantages over bone autografts in the reconstruction of craniofacial defects. These include: lack of donor site morbidity, unlimited quantities of available material, and the possibility to conform exactly to the defect. An ideal bioresorbable material would degrade slowly, and have osteoconductive properties to allow replacement and remodeling by osseous tissue. This is seldom observed, the materials instead being replaced by fibrous tissue. Polycaprolactone (PCL), an FDA-approved bioresorbable polymer, has several properties that might make it suitable for reconstruction of craniofacial defects. The technique of fused deposition modeling (FDM) allows for the fabrication of highly reproducible bioresorbable 3D scaffolds. The nature of the fully interconnected pore network might enhance vascular ingrowth and osteoconductive properties. It was hypothesized that coating the scaffolds in bone marrow might enhance bone formation due to the osteoinductive nature of the bone-marrow mesenchymal cells. This study aimed to test these hypotheses in the pig model. Defects measuring 2 x 2 cm were surgically created in each orbit of eight Yorkshire pigs. The orbits were divided into three groups: Group 1 (n=4), no reconstruction (control); Group 2 (n=6), reconstruction with no coated PCL scaffolds; and Group 3 (n=6) reconstruction with bone-marrow-coated PCL scaffolds. The results were evaluated at 3 months by histological and histomorphometric analyses. The defects in Group 1 were covered with fibrous scar tissue. The shape of the reconstructed area was insufficient. The defects in Groups 2 and 3 were reconstructed correctly. In Group 2 the noncoated scaffolds showed 4.5% of new bone formation compared with 14.1% in Group 3, which is statistically significant (p<0.05). The entirely interconnected 3D polycaprolactone scaffold seems to be a promising material. It induces the bone ingrowth required for reconstructing craniofacial and orbital defects. Further long-term evaluations of these PCL scaffolds must be made in order to confirm these conclusions. 相似文献
993.
994.
Suh SW Kim J Baek CH Han J Kim H 《ASAIO journal (American Society for Artificial Internal Organs : 1992)》2001,47(5):496-500
Reliable prosthetic or tissue grafts for the trachea have not, as yet, been developed for reconstruction of large, circumferential tracheal defects. Major limitations are anastomotic dehiscence and stenosis, attributed to the poor epithelialization and vascularization of the prosthetic graft. We have developed a new tracheal prosthesis that has a well vascularized and viable mucosa. The prosthesis consists of a Prolene mesh reinforced with polypropylene rings, and coated with gelatin. We lined the luminal surface of the prosthesis with transplanted autogenous oral mucosa, wrapped the prosthesis with greater omentum, and placed it in the peritoneal cavity for 2 weeks. Complete surgical resection and replacement of a segment (5 cm in length, 8 to 10 tracheal rings) of the thoracic trachea was then performed in nine adult mongrel dogs. The transplanted mucosa was well vascularized and maintained its normal histology in prereplacement analysis. Dogs with tracheal replacement regained their full activity and did not show any respiratory problems until sacrifice at 1, 2, and 6 months. After 6 months, the prostheses were completely incorporated by the host trachea in all dogs and confluent epithelialization was confirmed histologically from the upper to the lower anastomotic site of the prosthesis; furthermore, the transplanted mucosal cells had changed to ciliated columnar epithelium. 相似文献
995.
Unsu Jung Jason E Foley Andreas A Erdmann Yoko Toda Todd Borenstein Jacopo Mariotti Daniel H Fowler 《Biology of blood and marrow transplantation》2006,12(9):905-918
Rapamycin prevention of murine graft-versus-host disease (GVHD) is associated with a shift toward Th2- and Tc2-type cytokines. Recently, we found that use of rapamycin during ex vivo donor Th2 cell generation enhances the ability of adoptively transferred Th2 cells to prevent murine GVHD. In this study, using a method, without antigen-presenting cells, of T-cell expansion based on CD3,CD28 costimulation, we evaluated whether (1) rapamycin preferentially promotes the generation of Th2/Tc2 cells relative to Th1/Tc1 cells, (2) rapamycin-generated T-cell subsets induce cytokine skewing after allogeneic bone marrow transplantation (BMT), and (3) such in vivo cytokine skewing is sensitive to post-BMT rapamycin therapy. Contrary to our hypothesis, rapamycin did not preferentially promote Th2/Tc2 cell polarity, because rapamycin-generated Th1/Tc1 cells secreted type I cytokines (interleukin [IL]-2 and interferon-gamma) did not secrete type II cytokines (IL-4, IL-5, IL-10, or IL-13) and mediated fasL-based cytolysis. Rapamycin influenced T-cell differentiation, because each of the Th1, Th2, Tc1, and Tc2 subsets generated in rapamycin had increased expression of the central-memory T-cell marker, L-selectin (CD62L). Rapamycin-generated Th1/Tc1 and Th2/Tc2 cells were not anergic but instead had increased expansion after costimulation in vitro, increased expansion in vivo after BMT, and maintained full capacity to skew toward type I or II cytokines after BMT, respectively; further, rapamycin-generated Th1/Tc1 cells mediated increased lethal GVHD relative to control Th1/Tc1 cells. Rapamycin therapy after BMT in recipients of rapamycin-generated Th1/Tc1 cells greatly reduced Th1/Tc1 cell number, greatly reduced type I cytokines, and reduced lethal GVHD; in marked contrast, rapamycin therapy in recipients of rapamycin-generated Th2/Tc2 cells nominally influenced the number of Th2/Tc2 cells in vivo and did not abrogate post-BMT type II cytokine skewing. In conclusion, ex vivo and in vivo usage of rapamycin may be used to modulate the post-BMT balance of Th1/Tc1 and Th2/Tc2 cell subsets. 相似文献
996.
Yoon JH Lee HV Lee JS Park JB Kim CY 《The International journal of artificial organs》1999,22(11):769-777
There is a need to develop human hepatocyte cell lines which retain both replicating capacity and highly differentiated functions to facilitate the development of an efficient bioartificial liver. The present study was undertaken to differentiate, using sodium butyrate, the actively replicating immortalized human liver cell line. The effects of butyrate on cell growth and cell cycle were analyzed, and the albumin synthesis, cytochrome P450 and ammonia-detoxifying activity of the butyrate-treated cells were measured. Butyrate treatment resulted in G2/M arrest of the cell cycle and polygonal changes in the cell morphology. Neither the control nor the butyrate-treated cells showed transformed characteristics. Butyrate treatment increased the amount of albumin secretion, cytochrome P450 activity, and the urea production rate of the cells. The present study provides non-transformed human hepatocytes, which can replicate unlimitedly and then restore differentiated hepatocyte-specific functions by butyrate, and therefore, have applications for the development of an efficient bioartificial liver. 相似文献
997.
S. M. Lee C. H. Moon Y. B. Oh H. Y. Kim Y. Ahn E. J. Ko J. E. Joo 《Journal of Korean medical science》1998,13(5):545-547
Giant-cell interstitial Pneumonia (GIP) is a very uncommon respiratory disease. The majority of cases of GIP are caused by exposure to cobalt, tungsten and other hard metals. In this report, we describe GIP in a patient who worked in gas station and dealt in propane gas vessels. He presented with clinical features of chronic interstitial lung disease and underwent an open lung biopsy that showed DIP-like reaction with large numbers of intra-alveolar macrophages and numerous large, multinucleated histiocytes which were admixed with the macrophages. Analysis of lung tissue for hard metals was done. Cobalt was the main component of detected hard metals. Corticosteroid therapy was started and he recovered fully. 相似文献
998.
999.
Claude P. Muller Daniela Handtmann Nicolaas H. C. Brons Martin Weinmann Karl-Heinz Wiesmü ller Gü nther Spahn Michael Wiesneth Francois Schneider Gü nther Jung 《Virus research》1993,30(3):271-280
The measles virus induces a life-long immune response associated with antibodies specific for the fusion protein. To map the linear immunodominant recognition sites of the fusion (F) protein of the measles virus, we have reacted a complete set of 108 overlapping pentadecapeptides with purified IgG obtained from donor sera with elevated anti-measles titers. The antibodies recognized about 20% of the peptides and generated a characteristic binding pattern, defining about 6 or 7 distinctive regions (31–75; 111–145; 151–165; 191–215; 271–320; 421–440; 481–530) which include the major hydrophobic segment (111–145) of the intersubunit region and the C-terminal Cys-cluster region. The binding sites were located in close proximity of the few experimentally defined T cell epitopes. This pairing of T and B cell epitopes was corroborated by computer-assisted T cell prediction. The significance of a non-random association of T and B cell epitopes for processing and presentation is discussed. It is speculated that in long-term immunity against measles (F protein), B cells of the same sIg specificity play an important role both as antigen presenting cells and as antibody producing cells. In contrast to human sera from late convalescent donors, mouse and rabbit MV antisera with high neutralizing titers as well as neutralizing MV-F specific monoclonal antibodies did not react with the peptides. 相似文献
1000.
This study was designed to assess determinants of private clinics' productivity, and to compare city and county clinics in South Korea. We analyzed the revenue and patient data from all 9,212 private clinics in South Korea. This data was obtained from the Korean National Health Insurance Corporation, during the period between 1996 and 1999. We used a mixed model for repeatedly measured data. The following listed variables were used in our analysis: sex and age of physician, number of beds of clinics, competitiveness of medical institution, inhabitants'incomes, the proportion of elderly in the administrative unit, and time effects. Age, sex, number of beds, and specialty were found to be the most relevant determinants for the productivity of private clinics in both urban and rural settings, and number of clinics and beds per 100,000 and income of the administrative unit were found to be significant determinants, but only in city environments. 相似文献