临床疑似TTP-HUS患者血浆置换治疗引起的并发症

由于采用血浆置换(PE)治疗血栓性血小板减少性紫癜溶血性尿毒综合征(TTP HUS)频率的增加,PE引起的并发症也成为制定治疗方案时需要考虑的因素。由于TTP HUS的诊断常常是不确定的,掌握PE治疗利弊之间的平衡已成为制定适当治疗方案的焦点。之前,我们于1996年～2002年间曾两次报道     

肝细胞生长因子诱导实验性视网膜脱离的病理机制研究

目的 观察肝细胞生长因子（HGF）对视网膜色素上皮（RPE）细胞屏障功能的影响以及RPE内过度表达HGF导致视网膜脱离（RD）的病理机制。 方法 编码HGF（AdCMV.HGF）、绿色荧光蛋白（Ad CMV.GFP）的E1/E3缺失的腺病毒载体，以5×10⁴ 噬斑形成单位（pfu）/眼注射到成年有色兔的视网膜下。检查注射后3、7、14、28 d时的眼底及组织病理变化,利用免疫组织化学和酶联免疫吸附试验（ELISA）方法检测HGF在视网膜和玻璃体的表达水平。 结果 对照组注射Ad CMV.GFP眼显示GFP几乎仅表达于PRE单核细胞层，AdCMV.HGF注射眼在注射点处的PRE细胞出现强的HGF免疫阳性反应。玻璃体内HGF的表达水平在注射7 d后达到最高峰、28 d后降低到基础水平。在HGF的表达期内AdCMV.HGF注射眼出现慢性RD和脉络膜慢性炎症。在RD区域，视网膜下的空间内可见增生性的RPE细胞，部分实验兔眼还产生多层的细胞膜结构。 结论 RPE内过度表达的HGF能引发慢性浆液性RD，同时伴有视网膜下RPE增生。提示HGF可能作为治疗RD的作用靶点。(中华眼底病杂志，2007，23：193-197)     

Characteristics of children with endoscopically proved chronic bronchitis

This study evaluated by chart review the clinical, allergic, pathologic, and immunologic characteristics of 20 children found to have chronic bronchitis (CB) by bronchoscopic evaluation, including 13 children in whom CB was documented by endobronchial biopsy. Two additional children likely to have had CB also are described. In this study group, all of the patients were believed to have asthma as well. Chronic bronchitis was predicted by chronicity of symptoms and incomplete response to bronchodilators and corticosteroids, but it was not predicted by a history of allergy or laboratory evidence of systemic infection or inflammation. In the children described herein, CB often was associated with an IgG subclass abnormality. Bronchoscopic evaluation documented CB and provided biopsy and secretion samples. Although the histomorphic findings were heterogeneous, patients with CB usually had white blood cells present on Gram stains of secretions in addition to mononuclear cell infiltrates on biopsy specimens. Chronic bronchitis in these children seems to be distinct from CB in adults. Further studies will be needed to define CB in children.     

Differentiation of chick lens epithelial cells: involvement of the epidermal growth factor receptor and endogenous ligand

PURPOSE: To characterize the constitutively activated epidermal growth factor receptor in a lens epithelial cell population experiencing initial stages of lens fiber formation, the chick lens annular pad. METHODS: Phosphotyrosine levels of the receptor were examined with western blot analysis and immunoprecipitation after ligand stimulation. Endogenous receptor ligands were immunologically identified in whole cell lysates of freshly isolated cells. The expression of lens fiber-specific differentiation marker proteins was examined with western blot analysis and enzyme-linked immunosorbent assay (ELISA) in short-term primary cultures of annular pad cells exposed to ligand. RESULTS: The major phosphotyrosine-containing protein in annular pad cells comigrated with the epidermal growth factor receptor and increased its phosphotyrosine content after epidermal growth factor treatment. Both time- and dose-dependent responses were noted. The constitutive activation of the receptor was determined in the presence of phosphatase inhibitors. Endogenous transforming growth factor-alpha, but not epidermal growth factor, was detected in freshly isolated cells. Transforming growth factor-alpha (TGF-alpha) treatment produced greater increases in receptor phosphotyrosine levels than equimolar levels of epidermal growth factor. Finally, TGF-alpha treatment induced increased expression of the beaded filament protein filensin when compared with control cells. Filensin expression was increased further when cells were costimulated with TGF-alpha and cAMP analogs. CONCLUSIONS: At least in the postnatal lens, endogenous TGF-alpha may affect overall growth patterns by modulating differentiation-specific protein expression. Furthermore, signaling pathways elicited by TGF-alpha and cAMP analogs converge to cooperatively enhance lens fiber differentiation.     

Centration of donor trephination in human corneal transplantation

PURPOSE: To develop and evaluate a new method to quantify centration of the trephined donor cornea relative to the limbus. METHODS: After human donor corneas were trephined for penetrating keratoplasty, the remaining corneoscleral discs were stained and subjected to image analysis. The centration of the excised donor cornea relative to the limbus was calculated by measuring their centroids from the "captured" images. RESULTS: Fifty-two corneoscleral discs were analyzed. The average deviation from the centre was 0.32 mm (SD, 0.18 mm). Neither surgeon nor the type of trephine significantly influenced the mean centroid deviation. CONCLUSION: We have developed and evaluated a method to quantify centration of human donor cornea. In a small series, decentration did not correlate significantly with either the surgeon or the trephine.     

The female ACL: why is it more prone to injury?

Multiple factors are responsible for ACL tears. The key factor in the gender discrepancy appears to be dynamic, not static, and proximal, not distal. The factors involved in evaluating the female ACL are multiple. However, it is the dynamic movement patterns ot hip and knee position with increased flexion and a coordinated proximal muscle firing pattern to keep the body in a safe landing position that are the most critical factors. An ACL injury at an early age is a life-changing event. We can very successfully reconstruct and rehabilitate an ACL, but we cannot stop there. We must now go into the prevention arena. In the United States there is tremendous variation in the exposure and acquisition of skills of physical activities in our youth. Today, children are often playing inside, using computers and watching television-missing out on the opportunity to learn safe movement patterns. Therefore, physical movement classes should occur very early in life, teaching children to land safely and in control, similar to the cry of "get down, stay down" routinely heard during youth soccer. Similarly, specific strength training programs can address landing as well as foot movements during cutting in basketball. Coaches should issue stern warnings when athletes demonstrate a high-risk movement patterns such as one-leg landings, out-of-control baseline landings, or straight-leg landings. The warnings may serve to keep the athlete from "touching the hot stove again" for fear of getting burned. No athlete feels she will be the one to get injured. Therefore, prospective analysis is likely to be received more warmly by the athletes if the program is presented with an emphasis on performance improvement rather than injury prevention. With increased participation in these programs, multiple-center analysis will have the power necessary to determine which factors significantly predispose athletes to ACL injury. The future for injury prevention is bright. We must rise to the challenge.     

Does a kidney-sharing alliance have to sacrifice cold ischemic time for better HLA matching?

BACKGROUND: The Scotland-Northern Ireland Kidney Allocation Alliance was created in August 1998. The purpose was to optimize the transplant service through increased regional exchange, higher quality matched kidneys, and better organ distribution. METHODS: An analysis was performed on prospectively collected data regarding retrieval and transplant activity. The degree of HLA matching, the cold ischemic time (CIT), the balance of exchange, and graft survival were analyzed for a 2-year period after the introduction of the new alliance and compared with the last year before alliance. RESULTS: There was a 17.7% increase in the number of transplants performed. In the 2-year period, 78% of kidneys were exported from the retrieving center compared with 55% in the prealliance year, (P<0.05, chi2). The proportion of 000 mismatched transplants and other favorable matches increased from 9.5 to 21% and from 52.5 to 61%, respectively. There was no significant difference between the CIT for the three study periods, nor between the CIT for locally used kidneys versus those exchanged within the Alliance (P>0.05, Student's t test). The largest center was a net importer of kidneys, whereas small and medium-sized centers balanced their exchange within the 2-year period. The 1-year transplant survival rate improved from 81.5% in the prealliance year to 88.4% at the end of the second year. CONCLUSIONS: The introduction of a regional kidney allocation alliance has improved the degree of HLA matching and increased the exchange of organs, without a significant increase in the CIT and any detrimental effect on graft survival.