Response to parathyroidectomy at the axial and appendicular skeleton in renal patients.

AIM AND METHODS: We report increases in axial and appendicular bone density after parathyroidectomy in renal patients. Bone density was recorded pre-operatively and at 6 weeks, 6 months and 1 year post-operatively. We have previously reported that axial bone density increased dramatically at 6 weeks but that there were no early cohort increases at the appendicular skeleton [Stein et al. 1997]. RESULTS: We now report that at six months, bone density had continued to increase at the lumbar spine and femoral neck, with median respective 6 months increases over baseline of 1.3 (p < 0.01) and 0.7 (p < 0.01 ) Z-scores. Bone density then appeared to stabilize at the axial skeleton. At the appendicular skeleton increases were significant at the one year time point with median respective increases at the ultradistal radius and one third radius of 0.46 (p < 0.05) and 0.49 (p < 0.05) Z-scores. The different pattern of responses to parathyroidectomy between the axial and appendicular sites supports the concept that appendicular bone turnover is slower than axial bone turnover. Furthermore, at the appendicular skeleton, bone turnover appears similar between cortical and trabecular bone. CONCLUSION: In renal patients, bone density increases after parathyroidectomy at both the axial and appendicular skeleton. Axial increases are large and occur early. Appendicular increases occur at both cortical and trabecular sites but are slower than the axial changes.     

骶骨螺钉经上终板与经前皮质固定的生物力学比较

目的测试骶骨螺钉经上终板固定技术的生物力学性能,并与经前皮质固定技术比较。方法取17具新鲜成年男性骶骨标本,两侧分别采用螺钉经上终板固定和经前皮质固定技术。经前皮质固定的螺钉指向前内侧,平行于终板;经上终板固定的螺钉指向前内侧,矢状面上向头侧成30°～35°角,钉尖对向S1上终板的前部。植入螺钉时测定最大扭矩;通过模拟生理应力进行疲劳试验,测定固定刚度变化和拔出力。结果经上终板固定组螺钉最大扭矩为(3.18±0.49)Nm,经前皮质固定组为(1.98±0.76)Nm, 差异有非常显著性(P< 0.01),经上终板固定组比经前皮质固定组高60.6%; 经上终板固定组拔出力为(1457±276)N,经前皮质固定组为(1122±364)N, 差异有显著性(P< 0.05),经上终板固定组比经前皮质固定组高29.9%;在循环负载过程中,两组刚度在负载早期(前5000个循环)均明显下降,然后趋于平稳,经上终板固定组的最后刚度高于经前皮质固定组(P< 0.05)。两组中螺钉的最大扭矩与拔出力均有显著相关性,相关系数分别为0.94和0.95(P< 0.01)。结论骶骨螺钉经上终板固定技术与经前皮质固定技术相比有一定的力学优越性。     

Dorsal lunate tilt (DISI configuration): sign of scaphoid fracture displacement

Excessive dorsiflexion (dorsal tilting) of the lunate on a lateral wrist radiograph can be an important sign of carpal injury. Lunate dorsiflexion is a well-recognized sign of an intercarpal ligamentous injury pattern known as dorsal intercalated segment instability (DISI). It is less well recognized that excessive dorsal tilting of the lunate (DISI configuration) can also be produced by displacement of a scaphoid waist fracture. Since the management and prognosis of displaced scaphoid fractures may be quite different from those for nondisplaced fractures, radiologists can make an important contribution by recognizing dorsal tilting of the lunate and appreciating that it may be an important, indirect sign of scaphoid fracture displacement, which may not be directly visualized with standard wrist radiography. In this setting, computed tomography or complex motion tomography may be helpful for further evaluation of the scaphoid fracture.     

双波长一元线性回归分光光度法同时测定复方氨基比林注射液中三组分含量

本文依据一组含有不同比例待测和干扰组分的标准混合液的吸收值,采用一元线性回归方法,在选择最佳测定波长对的同时建立标准工作曲线方程,使其更符合实际作品测定时的情况,提高了结果的精度和可靠性,并使计算量和实验工作量得以降低。应用于复方氨基比林注射液中三组分氨基比林、安替比林和巴比妥的同时测定,其平均回收率分别为99.8%,100.4%和99.8%,变异系数分别为0.59,1.48和1.05,结果优于卡尔曼滤波法、偏最小二乘法和目标因子分析法。     

Cellulitis due to Pseudomonas putrefaciens: possible production of exotoxins

Pseudomonas putrefaciens has been described as a rare cause of both lower-limb cellulitis and septicemic illness with significant morbidity. We report a case of P. putrefaciens infection in a patient with refractory lower-limb cellulitis and ulceration complicated by thrombocytopenia, hypotension, and mental obtundation in the apparent absence of bacteremia. This scenario raises the possibility of significant production of exotoxins by P. putrefaciens in vivo.     

Human T cell responses against the major cysteine proteinase (cruzipain) of Trypanosoma cruzi: role of the multifunctional alpha 2- macroglobulin receptor in antigen presentation by monocytes

Chagas' disease patients (CDP) develop both humoral and cellular immune responses against the major cysteine proteinase (cruzipain) from Trypanosoma cruzi. Here we demonstrate that complexes formed by cruzipain and alpha 2-macroglobulin (alpha 2M) are efficiently internalized by human monocytes, and that this process results in enhanced presentation of cruzipain peptides to CD4+ T cells from CDP. Purified or serum alpha 2M binds to polymorphic cruzipains, but only a fraction of the proteinases become covalently linked. Once bound to alpha 2M, fluorescein-labeled cruzipain (FITC-cruzipain) or [125I]cruzipain were more efficiently internalized by normal peripheral blood mononuclear cells (PBMC) or monocytes; this effect was abolished by (I) pre-treating the cells with receptor-associated protein (rRAP), a known antagonist the of alpha 2M receptor (alpha 2MR/LRP), and (II) inactivating [125I]cruzipain's active site prior to the reaction with alpha 2M, indicating that the exposure of receptor binding sites on alpha 2M complexes required bait region cleavage. We then sought to determine if the alpha 2MR/LRP-dependent uptake of alpha 2M:cruzipain by monocytes resulted in increased CD4+ T cell responses of PBMC-CDP (n = 13). These effects were only revealed after depletion of CD19+ B lymphocytes from PBMC-CDP; the threshold of T cell stimulation was far lower in cultures stimulated with alpha 2M:cruzipain, as compared to antigen alone. Myocardial specimens from CDP with chronic myocardiopathy (three necropsies) were analyzed by immunohistochemistry with mAb anti-cruzipain or anti-alpha 2MR/LRP (CD81+). Extracellular depots of cruzipain were localized amidst inflammatory mononuclear infiltrates, part of which contained CD91+ macrophage-like cells. Ongoing studies should clarify if T. cruzi cysteinyl proteinases play a role in the pathogenesis of Chagas' heart disease.