Role of tumor necrosis factor alpha in particulate-induced bone resorption

The purpose of this study was to determine the role of tumor necrosis factor alpha in bone resorption secondary to mediator release from macrophages exposed to cement particles. The J774 mouse macrophage cell line was exposed to polymethylmethacrylate particles for 24 hours and the resulting conditioned medium was analyzed for prostaglandin E₂, tumor necrosis factor alpha, interleukin-1 alpha and beta, and the ability to stimulate release of prostaglandin E₂ and ⁴⁵Ca from radiolabeled mouse calvaria. Macrophage exposure to polymethylmethacrylate particles led to a 9-fold increase in release of tumor necrosis factor alpha (p < 0.01), but did not lead to a significant increase in release of prostaglandin E₂, interleukin-1 alpha, or interleukin-1 beta when compared to unexposed cells. Exposure of the macrophages to polymethylmethacrylate particles over a time course from 30 minutes to 96 hours led to an increase in the release of tumor necrosis factor alpha that was initially detected at 30 minutes and was maximum at 48 hours. Incubation of the macrophage-polymethylmethacrylate conditioned medium with rat calvaria significantly increased the release of ⁴⁵Ca and prostaglandin E₂ from the bone. To study the role of release of tumor necrosis factor alpha in bone resorption, the macrophage-polymethylmethacrylate conditioned medium was then preincubated with anti-tumor necrosis factor alpha antibody prior to exposure of the conditioned medium to the calvaria. This preincubation was successful in significantly inhibiting ⁴⁵Ca release by calvaria (p < 0.01) to levels that were not significantly different from the levels of release by unexposed calvaria. Tumor necrosis factor alpha appears to play a critical role in initiating particulate-induced bone resorption. Exposure of macrophages to polymethylmethacrylate particles leads to a significant release of tumor necrosis factor alpha in a time-dependent fashion. This macrophage-polymethylmethacrylate conditioned medium stimulated release of prostaglandin E₂ and bone resorption in bone organ culture. The addition of anti-tumor necrosis factor alpha antibody to this in vitro system inhibited the bone resorption stimulated by the macrophage-polymethylmethacrylate conditioned medium and partially suppressed the production of prostaglandin E₂. The sequence of events in this model for particulate-induced bone resorption appears to be initiated by the production of tumor necrosis factor alpha by the macrophage, followed by production of prostaglandin E₂ by cells in bone, and then by bone resorption.     

表皮生长因子对TPN大鼠肠粘膜机械屏障的影响

本文旨在探讨表皮生长因子（ＥＧＦ）对ＴＰＮ大鼠小肠粘膜机械屏障的保护作用。将４８只ＳＤ大鼠随机分为正常对照组、ＴＰＮ组以及ＴＰＮ－ＥＧＦ组。结果显示ＴＰＮ组大鼠小肠绒毛面积、高度、隐窝深度、隐窝细胞数及有丝分裂指数均较对照组明显降低（Ｐ〈０．０１）；ＴＰＮ－ＥＧＦ组与对照组比较无显著差异（Ｐ〉０．０５）。提示外源性补充ＥＧＦ能促进ＴＰＮ大鼠隐窝细胞增殖，恢复隐窝细胞生成率，从而达到保护肠粘膜机械屏     

A comparison of histological and immunohistochemical methods for quantifying the pathological lesions of Pick's disease

Counts of Pick bodies (PB), Pick cells (PC), senile plaques (SP) and neurofibrillary tangles (NFT) were made in the frontal and temporal cortex from patients with Pick's disease (PD). Lesions were stained histologically with hematoxylin and eosin (HE) and the Bielschowsky silver impregnation method and labeled immunohistochemically with antibodies raised to ubiquitin and tau. The greatest numbers of PB were revealed by immunohistochemistry. Counts of PB revealed by ubiquitin and tau were highly positively correlated which suggested that the two antibodies recognized virtually identical populations of PB. The greatest numbers of PC were revealed by HE followed by the anti-ubiquitin antibody. However, the correlation between counts was poor, suggesting that HE and ubiquitin revealed different populations of PC. The greatest numbers of SP and NFT were revealed by the Bielschowsky method indicating the presence of Alzheimer-type lesions not revealed by the immunohistochemistry. In addition, more NFT were revealed by the anti-ubiquitin compared with the anti-tau antibody. The data suggested that in PD: (i) the anti-ubiquitin and anti-tau antibodies were equally effective at labeling PB; (ii) both HE and anti-ubiquitin should be used to quantitate PC; and (iii) the Bielschowsky method should be used to quantitate SP and NFT.     

Glenoid labrum: preliminary work with use of radial-sequence MR imaging

The authors describe a magnetic resonance imaging method for examination of the glenoid labrum of the shoulder joint that utilizes a radial fast-imaging sequence. Seven shoulders were examined: a total of five in three healthy asymptomatic volunteers, one in a symptomatic patient not suspected of having a lesion of the glenoid labrum, and one in a patient with recurrent shoulder dislocation and surgical proof of an extensive tear of the labrum. The preliminary results suggest that this technique may advantageously demonstrate pathologic changes in the glenoid labrum and may contribute to the evaluation of the unstable and painful shoulder.