彩色多普勒超声对移植肾急性排斥反应的评价

目的:肾移植的成功与否关键在于及时发现和正确处理排斥反应。探讨无创伤性形态学和血流动力学检查手段彩色多普勒超声在移植肾急性排斥反应中的作用,为临床评估肾移植效果及移植肾功能提供客观的辅助性数据。方法:选择2004-01/2005-12在南京医科大学附属第一医院、江苏省人民医院行同种异体移植肾患者57例,其中经穿刺活检证实或最后临床诊断为急性移植肾排斥反应者22例,未发生排斥反应等并发症的移植肾功能正常者35例,患者均知情同意。采用Philips EnVisor彩色多普勒超声血流显像仪,对急性排斥反应肾移植患者进行二维超声和彩色多普勒血流显像检测,观察排斥反应患者甲基强的松龙冲击治疗前后移植肾脏的大小、形态结构、肾内血管树分布、血流灌注以及各级动脉血流参数(阻力指数,搏动指数)等指标的变化,并与移植肾功能正常患者进行比较。结果:急性排斥反应组2例患者发生严重并发症死亡,进入结果分析急性排斥反应组20例,移植肾功能正常组35例。①发生急性排斥反应时肾移植患者移植肾体积明显大于肾功能正常组(P<0.01);肾实质增厚,皮髓质界限模糊。给予甲基强的松龙冲击治疗后急性排斥反应组患者肾脏厚径显著小于治疗前(P<0.05);肾实质回声减低,皮髓质交界变清。②发生急性排斥反应时肾移植患者移植肾血流阻力指数、搏动指数均显著高于移植肾功能正常组(P<0.01)。治疗后急性排斥反应组患者肾血流阻力指数、搏动指数均显著低于治疗前(P<0.01),与移植肾功能正常组差异无显著性意义(P>0.05)。结论:彩色多普勒超声作为一种简便、经济的无创性技术,对移植肾血流阻力指数、搏动指数的追踪观察可为临床上评估肾移植效果提供较可靠的客观依据,对移植肾急性排斥反应的早期诊断有较高的评估价值。     

Biological evaluation of intervertebral disc cells in different formulations of gellan gum‐based hydrogels

Gellan gum (GG)‐based hydrogels are advantageous in tissue engineering not only due to their ability to retain large quantities of water and provide a similar environment to that of natural extracellular matrix (ECM), but also because they can gelify in situ in seconds. Their mechanical properties can be fine‐tuned to mimic natural tissues such as the nucleus pulposus (NP). This study produced different formulations of GG hydrogels by mixing varying amounts of methacrylated (GG‐MA) and high‐acyl gellan gums (HA‐GG) for applications as acellular and cellular NP substitutes. The hydrogels were physicochemically characterized by dynamic mechanical analysis. Degradation and swelling abilities were assessed by soaking in a phosphate buffered saline solution for up to 170 h. Results showed that as HA‐GG content increased, the modulus of the hydrogels decreased. Moreover, increases in HA‐GG content induced greater weight loss in the GG‐MA/HA‐GG formulation compared to GG‐MA hydrogel. Potential cytotoxicity of the hydrogel was assessed by culturing rabbit NP cells up to 7 days. An MTS assay was performed by seeding rabbit NP cells onto the surface of 3D hydrogel disc formulations. Viability of rabbit NP cells encapsulated within the different hydrogel formulations was also evaluated by Calcein‐AM and ATP assays. Results showed that tunable GG‐MA/HA‐GG hydrogels were non‐cytotoxic and supported viability of rabbit NP cells. Copyright © 2012 John Wiley & Sons, Ltd.     

Lactoferrin gene promoter: structural integrity and nonexpression in HL60 cells.

Lactoferrin is a member of the transferrin family of iron-binding proteins. It is found in several glandular epithelial tissues and human neutrophils, where it is localized to secondary granules. To examine the mechanisms controlling lactoferrin gene expression in neutrophils and defects in its expression in acute leukemia, we have cloned a lactoferrin cDNA from a chronic myelogenous leukemia library, and used it to obtain genomic clones representing the chromosomal lactoferrin gene. Using polymerase chain reaction, primer extension, and S1 analysis, we have identified the 5' end of the lactoferrin mRNA. We have defined a putative promoter region for the gene, and characterized its first two exons. In addition, we have examined the structure of these regions in DNA from HL60 cells. HL60 is a leukemic cell line that undergoes phenotypic neutrophil maturation on exposure to dimethyl sulfoxide (DMSO). However, the cells cannot be induced to express any secondary granule protein genes. We have shown that the 5' end of the lactoferrin gene, including the putative promoter region, is entirely normal in HL60. By Northern analysis, nuclear run-on studies, and primer extension assays we have shown that the gene is not transcribed in DMSO-induced HL60 cells. This supports the hypothesis that the defect in HL60 is an abnormality in the production or activity of a transacting regulator of lactoferrin gene expression.     

Evaluation of radiation therapy factors in prophylactic central nervous system irradiation for childhood leukemia: A report from the Children's Cancer Study Group

The results of six different types of central nervous system (CNS) prophylaxis were studied in two successive Children's Cancer Study Group clinical trials of children with acute leukemia. Radiation therapy doses and technical factors were analyzed in relation to survival, relapse-free survival, bone marrow and CNS relapse rates, and the toxicities encountered in 656 study children. They were randomized among: (1) 2400 rad to the craniospinal axis (CS) and 1200 rad to the abdomen and gonad (2) 2400 rad CS, (3) 2400 rad to the cranium (Cr) + intrathecal methotrexate (IT/MTX), (4) IT/MTX alone, (5) 1800 rad CS, and (6) 1800 rad Cr + IT/MTX. Hematologic, gastrointestinal and infectious disease complications were highest in group 1. The patients were divided into low and high risk categories, defined as those with initial white blood cell counts below and above 20,000/cumm. for outcome analyses. No statistically significant differences were detected in the five-year rates for relapse-free survival or survival, nor for CNS or bone marrow relapse among the 5 irradiated groups when equipment variables, total doses, field arrangements, fractionation, and protraction were analyzed. These results should be interpreted in the light of the group 4 children who had the highest CNS relapse rates (e.g., 33 % for low risk patients vs. 4–16% for their counterparts in the other 5 groups), but nonetheless had a generally similar bone marrow and survival experience. Exceptions to the foregoing are the better five-year survival rates of 64 and 73 % respectively for group 3 and group 6 high-risk boys, contrasted with 25–42 % for their counterparts in the other 4 groups.     

Single-acquisition chemical-shift imaging of a binary system with use of stimulated echoes

A method for separating binary chemical-shift components with a single image data acquisition by means of stimulated echoes is demonstrated. With a strategy analogous to the modified Dixon method, three stimulated echoes were acquired to form three complex images. In each of the images, the complex pixel intensities were imparted, by design of the pulse sequence, with a phase factor carrying chemical-shift or field inhomogeneity information. With these three images, true fat/water separation can be obtained in biologic tissues. Studies at high field strength (4.7 T) on a toluene phantom, a pseudo-binary chemical-shift system, were used to evaluate the applicability of the method. Its clinical feasibility was demonstrated on a healthy human subject in a 0.6-T whole-body imaging system.     

Effective dose of L-asparaginase for induction of remission in previously treated children with acute lymphocytic leukemia: a report from Childrens Cancer Study Group.

L-Asparaginase, in the dose of greater than or equal to 6000 IU/sq m three times weekly, was demonstrated to be an effective agent in reinduction of remissions in childhood leukemia. Four hundred thirteen children with acute lymphocytic leukemia were treated with L-asparaginase. Doses i.m. ranged from 300 to 12,000 IU/sq m. None of the patients had received prior asparaginase therapy. 6-Mercaptopurine was given p.o. concurrently. All of the patients had experienced several previous relapses, and their disease was not responsive to 6-mercaptopurine. L-Asparaginase was found to be effective in reinducing remissions at the following rates: 9.5% for 300 IU/sq m; 35.1% for 3,000 IU/sq m; 53.5% for 6,000 IU/sq m; and 62.5% for 12,000 IU/sq m. The drug was given three times weekly for four weeks. Hypersensitivity reactions occurred in 6.5% of patients.     

Persistent Erection (Priapism) for Months with Concomitant Infertility in Rats due to Protein-Energy-Malnutrition

Monatelange Erektion (Priapismus) mit konsekutiver Infertitität bei Ratten als Folge von Protein-Energie-Mangelernährung
Wachsende, männüche Sprague Dawley Ratten wurden 22 Wochen lang mit einer halbsynthetischen, 9% Rohprotein enthaltenden Diät gefüttert, wobei Kasein (Kontrollgruppe; I) oder Weizenbrotkruste (Gruppe II) die alleinigen Proteinquellen darstellten. Das Kontrollfutter in reduzierter Menge, in Anlehnung an den Futterverzehr der Krusten-Ratten, wurde einem dritten Kollektiv verfüttert (pair-fed-Gruppe; III). Nach 6 Versuchswochen zeigten sich in den Gruppen II und III erste pathomorphologische Genitalveränderungen, die sich in einer monatelangen Erektion manifestierten. Bei 97% der Krusten-Ratten, 67% der isoenergetisch gefütterten Kasein-Ratten, jedoch bei keinem Kontrolltier entwickelte sich am Ende des Beobachtungszeitraums eine Dauererektion. Nach der 15. Versuchswoche erzielten die pair-fed-Ratten 17%, die Krusten-Ratten nur 5% des Gewichtszuwachses der Kasein-Kontrollgruppe. Im Reproduktionstest mit gesunden weibl. SD-Ratten erwies sich nur 1 von 6 Krusten-Ratten als zeugungsfähig, nach anschließender 5wöchiger ad lib. Kasein-Wiederauffütterung konnte eine 83% Fertilität beobachtet werden. Der Pathomechanismus der nutritiv induzierten Dauererektion wird auf die ausgeprägte marastische Stoffwechsellage zurückgeführt, bedarf jedoch weiterer Aufklärung.     

Dengue outbreaks in Guánica-Ensenada and Villalba, Puerto Rico, 1972-1973.

Epidemics of dengue fever occurring in Puerto Rico in 1963 to 1964 and 1969 were caused by dengue-3 and dengue-2 (DN-2) viruses, respectively, but endemic dengue transmission has never been documented on the Island. Since the 1969 epidemic, a surveillance system has detected DN-2 activity on the Island during each of the years 1970 through 1973, which suggests endemic persistence of the virus. This report describes the investigation of localized outbreaks of DN-2 in Guanica-Ensenada (1972) and Villalba (1973), and presents epidemiological, serological, and virological data from the outbreaks. Analysis of geographic distribution of dengue activity in Puerto Rico in recent years indicates that the DN-2 transmission in 1970 to 1973 may represent a long tail-off of the 1969 epidemic rather than the emergence of a truly endemic situation.