CT图像中噪声产生机理与维修

本文重点阐述和分析了CT图像中的几种噪声产生的原因和对图像的影响,并结合笔者多年的维修经验,从理论和实际相结合,介绍了几种实用的维修方法,提出了减小噪声提高图像质量的有效措施。     

血塞通注射液对糖尿病视网膜病变临床前期血栓素B2及6-酮-前列腺素F1α的干预作用

目的观察血塞通注射液对糖尿病视网膜病变临床前期的干预作用及疗效评价.方法将符合诊断标准的6 3例糖尿病性视网膜病变临床前期患者随机分为观察组(44例)和对照组(41例).观察组给予血塞通注射液,对照组不予任何处理.观察治疗前后的血栓素B2(TXB2)及6-酮-前列腺素F1α(6-keto-PGF1α)的含量变化、评价疗效.结果与对照组比较,血塞通注射液能显著下调TXB2含量(P<0.01),上调6-keto-PGF1α含量(P<0.01),ARR=100.0%、RR=0、RRR=100.0%、NNT=1(例).结论血塞通注射液能显著干预和阻止糖尿病性视网膜病变;疗效评价显示治疗效果好,临床价值大.     

Nephrolithiasis associated with autosomal dominant polycystic kidney disease: contemporary urological management

PURPOSE: We evaluate the role of contemporary urological intervention in patients with nephrolithiasis associated with autosomal dominant polycystic kidney disease. MATERIALS AND METHODS: Intervention for upper tract stones associated with autosomal dominant polycystic kidney disease was performed in 5 women and 2 men 29 to 65 years old (mean age 47). Indications for intervention consisted of flank pain in 6 patients and/or hematuria in 2. A total of 12 procedures (mean 1.7 per patient) were performed, including shock wave lithotripsy in 6 patients, percutaneous nephrolithotomy in 2, retrograde endoscopy or manipulation in 3 and extended pyelonephrolithotomy in 1. RESULTS: All patients were rendered stone-free or had only residual "dust." Hospital stay for 5 patients was 1 night or less and there were no complications. Renal function for each patient was stable or improved as measured by serum creatinine. CONCLUSIONS: Most patients with autosomal dominant polycystic kidney disease who require intervention for nephrolithiasis can be safely and effectively treated with essentially any or all contemporary, minimally invasive techniques. The choice of intervention can be based primarily on size and location of the upper tract stones rather than the associated presence of polycystic kidneys.     

Variation in clinical outcome following shock wave lithotripsy

PURPOSE: We measure and compare operator specific success rates of extracorporeal shock wave lithotripsy (ESWL) performed by 12 urologists in 1 unit to determine interoperator variation. MATERIALS AND METHODS: From January 1, 1994 to September 1, 1997 a total of 5,769 renal and ureteral stones received 9,607 ESWL treatments by 15 urologists with a Dornier MFL 5000 lithotriptor. The 3-month followup data are available for 4,409 stones. Outcome measures consisted of patient demographics, stone characteristics, technical details of lithotripsy, and stone-free and success rates by treating urologists. RESULTS: Treatment results were analyzed for 12 urologists (surgeons A to L) who treated more than 100 stones each, totaling 4,244 with followup information available. Mean stone-free and success rates were 50.6% and 72.3%, respectively. Surgeon A had significantly higher stone-free and success rates of 56.2% and 76.7%, respectively (p<0.05), with treatment results from 877 stones, which was a significantly higher number than others (p<0.05). Significant differences existed in mean number of shocks delivered among urologists (p = 0.0001), with surgeons A and J delivering the highest mean numbers (2,317 and 2,801, respectively). There was no difference in treatment duration (p = 0.75) but variation existed among urologists in terms of mean maximum treatment voltage (p = 0.0001). Mean fluoroscopy time at 4.1 minutes was higher for surgeon A than others (p<0.05). Mean complication rate following ESWL was 4.9% with no difference among urologists (p = 0.175). Re-treatment was required in 21.7% of cases and surgeon A had the lowest rate (15.9%, p<0.05). CONCLUSIONS: We demonstrated clinically and statistically significant intra-institutional differences in success rates following ESWL. The best results were obtained by the urologist who treated the greatest number of patients, used a high number of shocks and had the longest fluoroscopy time. Accurate targeting is crucial when using a lithotriptor, such as the Dornier MFL 5000, with a narrow focal zone of 6.5 mm. in diameter. Other centers should be encouraged to develop similar programs of outcome analysis in an attempt to improve performance.     

卡托普利防治糖尿病小鼠视网膜病变的实验研究

目的:探讨卡托普利对糖尿病视网膜病变发生的防治作用。方法:应用免疫组织化学方法和计算机图象分析技术对糖尿病小鼠未治疗组和卡托普利治疗组视网膜组织AngII和VEGF进行免疫组织化学测定和半定量分析。结果:AngII和VEGF在两组小鼠视网膜神经节细胞和血管内皮细胞均为阳性表达,而在正常对照组两者均为阴性表达。与糖尿病未治疗组相比,卡托普利治疗组的AngII和VEGF的平均灰度值明显增加,而面密度值明显降低,说明治疗组的免疫信号降低,阳性表达细胞数减少。结论:卡托普利可降低糖尿病小鼠视网膜组织AngII和VEGF的阳性表达,推测其对糖尿病视网膜病变具有一定的保护作用。     

周细胞条件培养液对视网膜色素上皮细胞、胶质细胞及巨噬细胞增殖的影响

目的观察体外培养的视网膜周细胞条件培养液对视网膜色素上皮细胞、巨噬细胞及胶质细胞生长的影响。方法MTT法测定不同稀释度的周细胞条件培养液对色素上皮细胞、巨噬细胞及胶质细胞生长的影响。结果随着周细胞条件培养液稀释度的增加,其对上述细胞的抑制生长作用亦越明显。结论周细胞的缺失将导致色素细胞、巨噬细胞及胶质细胞的增殖,细胞间相互作用对于糖尿病视网膜病变的发生和发展是非常重要的。     

Immunobiologic, cytogenetic and drug response features of a newly established cell line (SCRC-1) from renal small cell carcinoma

PURPOSE: We describe the establishment and preliminary characterization of a cell line designated SCRC-1, which was derived from a primary renal small cell carcinoma. MATERIALS AND METHODS: Continuous cultures of a primary stage IVa renal small cell carcinoma and a xenograft in nude mice derived therefrom were characterized by immunohistology, electron microscopy, immunofluorescence/flow cytometry, cytogenetic analysis, and an in vitro drug resistance assay. RESULTS: SCRC-1 cells were reactive with antibodies to NSE, chromogranin-A, bombesin, Bcl-2, CD44s, CD44v6, CD44v7 to 8, vimentin and S100 protein (predominantly beta-subunit), and were unreactive with antibodies to EMA, CD54, EGFR(R1), URO-5, URO-7, URO-8 and URO-10. A similar immunoprofile was also found in both the primary tumor and the xenograft. Cytogenetic analysis revealed the following common clonal aberrations in all 50 metaphases analyzed: 45, XX, t (X;10;18) (p11;p11;q11), -der(18)t(X;10;18), indicating the clonal nature of this neoplasm. SCRC-1 cells showed low drug resistance to cyclophosphamide, doxorubicin, gemcitabine and fluorouracil, intermediate resistance to carmustine and mitomycin-C, and extreme resistance to cisplatin. CONCLUSION: We have documented the initial characterization of SCRC-1, which may be the first cell line reported to be derived from a primary small cell carcinoma of the kidney. This cell line can be used for further studies uncovering the biology and histogenesis of this rare cancer and delineating differences among small cell carcinomas of the kidney and other histological types.     

糖尿病视网膜病变光凝术后角膜知觉的改变

目的 探讨糖尿病视网膜病变患者在全视网膜光凝术后的角膜知觉改变及影响因素。方法 32例(32只眼)糖尿病视网膜病变患者应用倍频ND：YAG激光行全视网膜光凝，光凝斑大小：200～300／μm，光凝时间：0．2～0．4秒，光凝斑强度以达到中等强为标准。采用Cochet--Bonnnnet角膜知觉测量仪测量光凝前及光凝后1、2、3、4、5、6周及2个月的角膜知觉。结果 糖尿病视网膜病变患者术前的角膜知觉为2．27cm，术后1、2、3、4、5、6周及2个月的角膜知觉分别为1．42cm、1．60cm、1．58cm、1．92cm、1．71cm、2．19cm和2．23cm。与术前相比，术后1～5周的角膜知觉减退值与术前的角膜知觉的相关系数为0．82。结论 糖尿病视网膜病变行全视网膜光凝后的角膜知觉有明显减退，在光凝后6周恢复至术前水平，角膜知觉的减退值与光凝的范围及术前的角膜知觉有关。