Characterization of a highly polymorphic marker adjacent to the SLC4A1 gene and of kidney immunostaining in a family with distal renal tubular acidosis.

BACKGROUND: Mutations in the human SLC4A1 (AE1/band 3) gene are associated with hereditary spherocytic anaemia and with distal renal tubular acidosis (dRTA). The molecular diagnosis of AE1 mutations has been complicated by the absence of highly polymorphic genetic markers, and the pathogenic mechanisms of some dRTA-associated AE1 mutations remain unclear. Here, we characterized a polymorphic dinucleotide repeat close to the human AE1 gene and performed an immunocytochemical study of kidney tissue from a patient with inherited dRTA with a defined AE1 mutation. METHODS: One CA repeat region was identified in a phage P1-derived artificial chromosome (PAC) clone containing most of the human AE1 gene and the upstream flanking region. We determined its heterozygosity value in multiple populations by PCR analysis. Genotyping of one family with dominant dRTA identified the AE1 R589H mutation, and family member genotypes were compared with the CA repeat length. AE1 and vH(+)-ATPase polypeptides in kidney tissue from an AE1 R589H patient were examined by immunocytochemistry for the first time. RESULTS: This CA repeat, previously reported as D17S1183, is approximately 90 kb upstream of the AE1 gene and displayed considerable length polymorphism, with small racial differences, and a heterozygosity value of 0.56. The allele-specific length of this repeat confirmed co-segregation of the AE1 R589H mutation with the disease phenotype in a family with dominant dRTA. Immunostaining of the kidney cortex from one affected member with superimposed chronic pyelonephritis revealed vH(+)-ATPase-positive intercalated cells in which AE1 was undetectable, and proximal tubular epithelial cells with apparently enhanced apical vH(+)-ATPase staining. CONCLUSIONS: The highly polymorphic dinucleotide repeat adjacent to the human AE1 gene may be useful for future studies of disease association and haplotype analysis. Intercalated cells persist in the end-stage kidney of a patient with familial autosomal dominant dRTA associated with the AE1 R589H mutation. The absence of detectable AE1 polypeptide in those intercalated cells supports the genetic prediction that the AE1 R589H mutation indeed causes dominant dRTA.     

Effects of mycophenolic acid on IL-6 expression of human renal proximal and distal tubular cells in vitro.

BACKGROUND: Interleukin-6 (IL-6) is a multifunctional cytokine which regulates immune responses and host defence mechanisms. IL-6 has been found to be increased in certain inflammatory conditions of the kidney, in which tubular epithelial cells play a pivotal role. Human renal tubular cells express IL-6. Until now no data about the effect of the immunosuppressant drug mycophenolic acid (MPA) on IL-6 expression were available. METHODS: Proximal and distal tubular epithelial cells (PTC/DTC) have been isolated immunomagnetically. Confluent monolayers were stimulated with interleukin-1beta (IL-1beta; 25 U/ml), IL-1beta+ MPA (0.25-50 micro M) or MPA alone for 48 h. Release of IL-6 protein into the supernatant was evaluated with an enzyme immunoassay, IL-6 mRNA expression was evaluated using the Quantikine mRNA kit. RESULTS: After IL-1beta stimulation, a highly significant 2.6- (PTC) and 3.8-fold (DTC) upregulation of IL-6 expression was detectable. IL-6 mRNA was upregulated by IL-1beta [1.57- (PTC) and 2.03-fold (DTC)]. MPA inhibited this cytokine-induced IL-6 expression in a dose-dependent manner. Incubation with the lowest MPA concentration had no effect on the stimulated upregulation, whereas all higher doses significantly decreased IL-6 expression. Dexamethasone significantly inhibited the cytokine-induced IL-6 protein release in PTC, but not in DTC. CONCLUSIONS: In this study we demonstrated for the first time an inhibitory effect of MPA on the stimulated IL-6 expression of renal tubular epithelial cells. In contrast to older data, which showed a synergistic upregulation of the expression of a CC-chemokine by a combination of cytokines and MPA, in the present study we could demonstrate an immunosuppressive effect of MPA on the expression of an important cytokine.     

ENDOSCOPIC PANCREATIC STENTING IN CHRONIC PANCREATITIS WITH DUCTAL DILATION PROXIMAL TO A STRICTURE: A SAFE and EFFECTIVE PROTOCOL

After removal of intraductal stones, a 10‐Fr or 7‐Fr pancreatic stent was placed in 16 patients with upstream ductal dilation proximal to a stricture of the main pancreatic duct. Stents were removed after a mean duration of 52.5 days. Nine patients underwent repeated stenting. About one year after removal of the initial stent, when the remaining upstream ductal dilation was found on follow‐up pancreatograms, the next stent was replaced. Repeated stenting improved outflow of pancreatic juice more effectively than one‐time stenting. Correlation between long‐term pain relief without recurrence of intraductal stones and reduction of duct diameter was also shown. Stent occlusion was observed in 14 of 30 stents. Stent occlusion was frequently associated with recurrence of pancreatitis and intraductal stones, and was also associated with morphologic changes in the pancreatic ductal system. Although there were no significant differences between stent patency of the initial stents and that of the next stents, stent patency of 10‐Fr stents was superior to that of 7‐Fr stents. 10‐Fr stents should be removed within 8 weeks and 7‐Fr stents should be removed within 4 weeks for the prevention of stent occlusion. Repeated stenting with short‐term stenting is therefore considered a safe and effective protocol of endoscopic pancreatic stenting.     

Bone mineral density of the proximal tibia following uncemented arthroplasty

Bone mineral density (BMD, g/cm2) was measured using dual-photon absorptiometry (DPA) in selected areas of the proximal tibia following uncemented PCA knee prosthesis. In nine patients with 14 alloplastic operations, measurements were taken at 3-6-month intervals for the first 3 1/2 years after operation. There was a significant increase in BMD of about 15% during the first 6 months after operation. The following year it remained increased, although not significantly, compared with the initial values, then gradually diminished. Increased bone density after arthroplasty may be explained mainly by stimulation of bone formation from weight bearing due to improved walking ability. Stress shielding of the proximal part of the supporting tibial bone did not seem to occur.     

计算机X射线摄影新旧成像板的比较

目的 通过体模检测和病例检查的对照研究,比较计算机X射线摄影(computed radiography,CR)新旧两种不同成像板(IP)对影像质量和病人辐射的影响,探讨新旧IP的使用原则。方法 对新旧IP进行常规暗噪声、均匀性和一致性、擦除完全性检测;根据阈值对比度-细节检测能力(TCDD)技术,75 kV时新旧IP对体模TO.16进行摄影,请3位观察者采用双盲法对所得影像进行观察评分,计算阈值检测指数H_T(A);结合临床用相同曝光条件,不同的IP分别对膝关节、胸部、腰椎进行投照,请3位放射专家进行双盲阅片,评价影像质量。结果 新旧IP在物理指标上基本相同,在相同曝光条件下,新IP的检测能力高于旧IP,当旧IP提高20%的辐射剂量后,旧IP检测能力接近新IP。结论 随着IP使用次数的增加,需逐步提高曝光剂量才能保证影像质量;若保持原有剂量不变,IP的检测能力就会下降,将影响疾病的诊断。     

计算机导航在骨科手术中的应用

目的将计算机导航技术应用于骨科手术,并对其进行初步分析。方法2004年2～12月,计算机导航系统辅助下共行134枚椎弓根螺钉固定,51枚股骨颈骨折空心钉内固定,58枚交锁髓内钉远端交锁螺钉固定。结果所有病例全部在导航下完成手术,术中明显减少C型臂X线机透视次数,未发生血管和神经损伤并发症。结论计算机导航手术安全有效,更有利于微创手术的开展。     

生长板软骨细胞促进骨髓基质干细胞血管内皮生长因子的表达

目的观察骨髓基质干细胞(BMSCs)在生长板软骨细胞旁分泌作用下血管内皮生长因子(VEGF)的表达规律及其与成骨分化的相关性。方法大鼠BMSCs与生长板软骨细胞进行间接共培养,培养终末期做细胞化学染色,定量测定碱性磷酸酶(ALP)活性,用RT-PCR方法半定量检测VEGFmRNA的表达。结果生长板软骨细胞持续高表达VEGF。BMSCs随共培养时间的延长,ALP活性升高,BMSCs的VEGF的表达也逐渐增强。培养液加入两种分泌型VEGF中和抗体后,VEGF表达趋势不变,ALP活性仍为升高趋势,也不影响培养终末期钙化结节的形成。培养终末期BMSCs的CD31和CD34均阴性。结论BMSCs成骨分化过程中VEGF的表达符合成骨细胞分化基因的表达规律,与成骨细胞特征性基因的表达趋势一致,体外条件共培养条件下,中和VEGF后并不能阻碍BMSCs的成骨分化。     

Scintigraphic validation of AC Biosusceptometry to study the gastric motor activity and the intragastric distribution of food in humans

Abnormal intragastric distribution of food (IDF) and a phasic contractility in the proximal stomach have been related to dyspeptic symptoms. Thus, the behaviour of the stomach and the proximal region, in particular, continues to attract attention and demand for reliable and comfortable techniques. The aims of this study were to employ AC Biosusceptometry (ACB) and scintigraphy to evaluate IDF and gastric motor activity in humans. Fifteen healthy volunteers ingested 60 mL of yogurt containing 2 mCi of 99mTc and 4 g of ferrite. Each volunteer had gastric motility and IDF evaluated twice on separate days; on one occasion by ACB and another by scintigraphy. Digital signal processing was performed in MatLab (Mathworks Inc., Natick, MA, USA). Results were expressed as mean +/- SD. Similar results of distal accumulation time (P < 0.001) were obtained for scintigraphy (6.93 +/- 3.25 min) and for ACB (7.04 +/- 3.65 min). Fast Fourier Transform revealed two dominant frequencies (P > 0.9). Besides the well-know frequency of 3 cpm, our results showed identical frequencies in proximal stomach recordings (P < 0.001) for scintigraphic (1.01 +/- 0.01 cpm) and ACB (0.98 +/- 0.06 cpm). In summary, our data showed that scintigraphy and ACB are promising techniques to evaluate several aspects of gastric motility. Moreover, ACB is non-invasive, radiation-free and deserves the same importance as conventional methods for this kind of analysis.     

颈椎后路螺钉-钛棒(板)内固定技术:初步临床报告

目的 报告利用螺钉-钛棒（板）固定技术治疗各种原因引起的颈椎不稳的初步临床结果。方法 作者1年来行颈椎后路螺钉-钛棒（板）技术内固定9例，其中齿突样骨引起的C1～C2不稳2例，手术后进行性颈椎后凸2例，颈椎管狭窄2例，C3-C4滑脱1例，C6～C7外伤滑脱2例。分别采用C1侧块、C2椎弓根螺钉、C3～C5侧块螺钉、C2-T2椎弓根螺钉植入技术，然后连接钛棒或钛板完成固定。9例病人共植入螺钉59枚。结果 所有病人在1周内带外支架进行活动，除1例因拒绝治疗死亡外，其余病人在1个月及1年后复查均未见内固定物移位。结论 颈椎后路螺钉-钛棒（板）固定为安全可靠的技术，可以术后即刻获得牢固内固定，为下一步治疗创造有利条件。     

人工肱骨头置换术治疗高龄复杂肱骨近端骨折

目的探讨和分析采用人工肱骨头置换术治疗复杂肱骨近端骨折的适应证、手术技术要点和早期疗效。方法对12例肱骨近端四部分骨折伴肱骨头脱位的高龄患者,早期手术行人工肱骨头置换。手术采用三角肌胸肌间入路,先复位大小结节,确定假体高度,骨水泥固定假体保持30°左右的后倾,大小结节再复位固定,必要时取骨折的肱骨头自体骨植骨,术后早期功能锻炼。结果术后平均随访16．6个月,术后未发生感染、神经损伤、关节脱位和假体周围骨折。采用Neer评分系统评定人工关节功能,平均为84．4分,90分以上(优)3例,80～89分(满意)7例,70～79分(不满意)2例,满意率为83．3%。12例患者疼痛方面平均得分为33．5分,功能方面为25．6分,运动方面为16．5分,解剖重建方面为8．8分。结论在正确选择手术适应证、掌握手术技术以及合理的术后康复等前提下,人工肱骨头置换术是治疗高龄患者复杂肱骨近端骨折的有效方法,尤其在减轻创伤后肩关节疼痛方面效果最为显著。但在恢复肩关节活动度方面仍欠满意,需加强对患者术后关节康复训练的指导工作。