Improved Performance of Hip DXA Using a Novel Region of Interest in the Upper Part of the Femoral Neck: In Vitro Study Using Bone Strength as a Standard of Reference

We tested the hypothesis that bone mineral density (BMD) and bone mineral content (BMC) in proximal human femur specimens in the upper neck region of interest (ROI) and femoral neck axis length (FNAL) provide a significantly better prediction of femoral bone strength than standard ROIs in vitro. BMD and BMC were measured in 110 proximal femur specimens using a standard dual-energy X-ray absorptiometry (DXA) scanner. The analysis included a new ROI in the upper neck as well as the standard ROIs. FNAL was obtained from the scan images. The specimens' failure-load was measured in a mechanical loading device, simulating a fall on the greater trochanter. For the standard ROIs, correlations between failure-load and BMD ranged from R2 = 0.64 (shaft ROI) to R2 = 0.70, p < 0.001 (femoral neck). Prediction of strength by BMD did not significantly differ from those of BMC (R2 ranging from 0.65 to 0.75, p < 0.001). In the upper neck ROI, for both BMD and BMC correlations with failure-load were higher (R2 = 0.76 and 0.81, respectively; p < 0.001). A lower, yet still significant, correlation was found between FNAL and bone strength (R2 = 0.23, p < 0.001). Normalization of failure-load with respect to FNAL did not significantly increase the correlations with densitometric measures. This study provides in vitro evidence indicating that among the ROIs of the proximal femur the newly defined upper neck ROI provides the best prediction of bone strength. Only a weak association was observed between failure load and FNAL.     

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.     

胃上部癌的经腹外科治疗

目的 提高胃上部癌外科治疗水平。方法 对94例胃上部癌采用了经腹正中切口或合并切除剑突及左第7～9肋弓软骨入路，行近端胃或全胃切除术。结果 全组病例发生吻合口瘘1例，食管断端癌残留3例和肺部感染8例，无肋软骨炎及胸膜损伤所致血气胸发生。结论 胃上部癌经腹入路暴露良好，创伤小，痛苦少，适用于食管无浸润或浸润小于1cm的胃上部癌的患者。     

Proximal myotonic myopathy

Three Swedish patients with proximal muscle weakness, myotonia and lack of CTG expansion on genetical analysis are presented. Clinical neurological and neurophysiological examination and muscle biopsy were performed. There was an indication of autosomal dominant inheritance in 2 of the 3 patients. The main symptoms and clinical findings in the 3 patients were weakness of the proximal muscles, myotonia, muscle stiffness, muscle pain and muscle atrophy. Neurophysiological examination showed myotonic bursts and muscle biopsy snowed a variation of fibre sizes, an increased number of muscle fibres with centralized nuclei and scattered atrophic muscle fibres. Laboratory data showed elevated CK, GT and LD in 1 patient. Before genetical analysis was performed, all 3 patients had been diagnosed as atypical cases of myotonic dystrophy. However, the symptoms, clinical signs, laboratory data, electrophysiological and muscle biopsy findings were compatible with proximal myotonic myopathy (PROMM).     

NF-κB对尿白蛋白诱导肾小管上皮细胞骨桥蛋白转录的影响

目的研究NF-κB对尿白蛋白诱导肾小管上皮细胞骨桥蛋白转录的影响。方法去脂的小牛血清白蛋白(BSA)20mg/ml分别加入到体外培养的肾小管上皮细胞和加入NF-κB抑制剂(PDTC)共同培养半小时的肾小管上皮细胞内,EMSA、RT-PCR检测不同时限NF-κB活性、骨桥蛋白mRNA表达情况。结果去脂的小牛血清白蛋白可刺激肾小管上皮细胞内NF-κB活性增加,骨桥蛋白mRNA表达上调,而提前加入NF-κB抑制剂(PDTC)共同培养半小时的肾小管上皮细胞内NF-κB活性、骨桥蛋白mRNA表达明显下降。结论尿白蛋白诱导小管上皮细胞损伤的机制与诱导肾小管上皮细胞内NF-κB活性、骨桥蛋白mRNA增加有关,而且骨桥蛋白转录由NF-κB调控。     

猪肾近端小管的超微结构

目的 研究猪肾近端小管的超微结构。方法 树脂包埋一超薄切片、透射电子显微镜技术。结果 猪肾近端小管可分S1、S2、S3和S4段构成，其中S1、S2段构成了近端小管曲部，S3、S4段构成了近端小管直部。本文对各段细胞超微结构特点进行详细的描述。结论 猪肾近端小管的超微结构与人肾近端小管最接近。     

The effect of pH and nucleophiles on complement activation by human proximal tubular epithelial cells.

BACKGROUND: Activation of urinary complement proteins in situ by proximal tubular epithelial cells (PTEC) may contribute to the mediation of tubulointerstitial injury in patients with significant proteinuria. However, the mechanism involved is unclear, and the role of changes in urinary pH and in the concentrations of urea or ammonia requires further clarification. METHODS: The protein fraction of urine samples from nine patients with proteinuria >1.5 g/day was purified. A cell ELISA involving cultured HK-2 PTEC was used to investigate the capacity of urinary protein to promote the deposition of both C3 and C9 on the cell surface. The effect of variations in pH (5.5-8.0) and in the concentration of urea and ammonia was also examined. C3 was purified and used to further investigate the mechanism of complement deposition. RESULTS: Urine samples from the majority of patients induced deposition of C3 and C9 on the surface of HK-2 cells via the alternative pathway. This process was maximal at acidic pH values. Preincubation of urinary complement or serum with urea or ammonia inhibited C3 deposition. Purified C3 incubated with HK-2 cells showed no evidence of activation in the absence of other complement components. CONCLUSIONS: These data suggest that bicarbonate protects against complement-mediated damage in the lumen by increasing the local pH, rather than by inhibiting the generation of ammonia. PTEC appear to activate complement through provision of a 'protected site' on their surface, rather than by the activation of C3 by convertase-like protease(s).     

醋酸棉酚对大鼠肾皮质形态结构的影响

醋酸棉酚每天30mg/kg(6次/周)给药6～8周后,大鼠肾曲小管线粒体肿胀,嵴模糊,伴有早期溶酶体增多、增大,形态多样,其后转而减少、变小。肾近曲小管微绒毛水肿,部分肾曲小管基底膜水肿。未见肾小球毛细血管内皮细胞、基膜和足细胞的超微结构明显变化。