The role of morphogens in endochondral ossification

Summary The formation of bone occurs normally by one of two developmental processes: intramembranous or endochondral ossification. Endochondral ossification occurs in the morphogenesis of the limb buds and growth plates, and in the regeneration of bone following injury (fracture callus). Two classes of diffusible morphogen-like molecules (MLMs) involved in limb development are the bone morphogenetic proteins (BMPs) and retinoic acid (RA). These MLMs are associated, respectively, with the apical ectodermal ridge (AER) and the zone of polarizing activity (ZPA) of the primitive limb bud. They function as potent regulators of pattern formation and are involved in tissue proliferation and differentiation. The presence of endochondral ossification in fracture callus suggests a role for MLMs in that process as well. To date, virtually nothing is known about the role of morphogens in the regeneration of bone (fracture healing). In this article, we review the current knowledge of MLMs in bone formation and propose a theory on their role in fracture healing. We hypothesize that MLMs involved in fracture healing may also express spatial and temporal information. A more complete understanding of the role of morphogens in both limb development and fracture healing is of major importance to practicing orthopedists and their patients.     

Proton magnetic resonance spectroscopic imaging for discrimination of absence and complex partial seizures

We performed proton magnetic resonance spectroscopic imaging of the temporal lobes between, during, and soon after nonconvulsive seizures in 20 patients with documented temporal lobe epilepsy, 5 patients with primary generalized epilepsy, and 2 patients with secondary generalized epilepsy. Our objective was to determine whether there were metabolic changes observable by magnetic resonance spectroscopic imaging during seizures and whether these changes were specific for focal or generalized nonconvulsive seizures. We found a significant increase in lactate to creatine plus phosphocreatine (lactate/creatine) values, reflecting an imbalance in energy supply and demand or an adaptation in response to ictal neuronal discharges, during and soon after complex partial seizures, but not during or soon after absence seizures associated with generalized epilepsy. In patients with temporal lobe epilepsy, the N-acetylaspartate resonance relative to creatine plus phosphocreatine was low in one or both temporal lobes, indicating neuronal loss or damage. This was not observed in patients with primary generalized epilepsy. The regions with abnormal lactate/creatine and N-acetylaspartate/creatine values corresponded to the epileptogenic focus as defined by clinical-electroencephalographic investigation. There was no change in the N-acetylaspartate/creatine values in the temporal lobes between the interictal, ictal, or postictal states. We conclude that (1) partial seizures are associated with abnormally high lactate levels, but absence seizures are not, and (2) no short-term changes of N-acetylaspartate occur during or soon after complex partial seizures or absence seizures. These findings may be related to the lack of postictal confusion in patients with absence seizures, as well as with the more benign course of primary generalized epilepsy with nonconvulsive attacks.     

肥大细胞的浸润对胃癌生长转移的影响

OBJECTIVE: To investigate the relationship between mast cell infiltration and the development and metastasis of gastric carcinoma. METHODS: Alcian blue-Safranin O staining and image analysis system were employed to observe, classify and quantify the mast cells in 74 gastric carcinoma specimens. RESULTS: Mast cells resided predominantly in the marginal area of the tumor and most of them were mature type, active and capable of discharging granules into the cytoplasm. The mast cells in the marginal area of the tumor were significantly more numerous than those in the matrix of the tumor (P<0.01) and there was a positive correlation between them (r=0.303, P<0.01). The density of the mast cells was inversely correlated to the depth of tumor invasion and the number of lymph node metastasis. CONCLUSIONS: Mast cell infiltration in the matrix of the tumor plays an important role in preventing the invasion and metastasis of gastric carcinoma possibly by release of heparin and other bioactive substances. Mast cell quantity in the marginal area of the tumor may serve as an indicator for prognostic assessment of gastric carcinoma.     

养阴清热、宣痹通络法治疗类风湿性关节炎的临床研究

目的 观察清络通痹颗粒治疗类风湿性关节炎阴虚络热证的临床疗效。方法 将118例患者随机分为清络通痹颗粒治疗组63例和雷公藤多甙片对照组55例，观察用药前后主要症状、体征和实验室检测指标的变化。结果 治疗组的临床治愈率为9．52％，临床治愈显效率为38．10％，总有效率为90．48％，疗效明显优于对照组的0％、20％、83．64％（P＜0．05）；治疗组的类风湿因子滴度、血沉、C反应蛋白、免疫球蛋白也明显降低，与对照组相比差异显著（P＜0．05或P＜0．01）。结论 清络通痹颗粒具有抗炎镇痛、调节免疫紊乱等作用，从而达到控制病情的治疗效果。     

What has trust got to do with it? Cardiac risk reduction and family physicians' discussions of evidence-based recommendations

The management of patients through the use of evidence-based medicine has become the 'mantra' of medicine within many Western countries. Evidence-based medicine is aimed at providing the best objective, scientific care to all patients, and reducing as far as possible patients' risks of disease and complications from disease. Based on family physicians' discussions of the use of evidence-based recommendations for two cardiac diseases, this paper explores how subjectively-based trust enters into family physicians' decision to use evidence-based medicine. In addition, we show how trust influences physicians' work of recommending evidence-based medicine to patients, and physicians' perceptions of why patients follow recommendations aimed at risk reduction. We conclude that although much of the current discussion about evidence-based medicine assumes a 'rational' model of physician behaviour based on the application of the 'best objective scientific' results, subjectively-based perceptions of trust influence physician practices, and point to the need to understand the power of relational issues in influencing physician practices even when utilizing evidence-based knowledge.     

rhBMP-2对不同培养时间骨髓基质干细胞成骨能力的影响

目的：探讨不同培养阶段骨髓基质干细胞成骨能力的变化及BMP-2对其成骨能力的影响。方法：培养兔骨髓基质干细胞，测定第3代和第18代细胞碱性磷酸酶及骨钙素活性；测定BMP-2对不同培养时间骨髓基质干细胞成骨能力的影响；测定rhBMP-2对细胞增殖的影响。结果：细胞传至第18代后，分泌的骨钙素（OC）水平及ALP活力明显降低，与第3代细胞相比，差异显著（P〈0．05）。第3代细胞在rhBMP-2的诱导下，分泌的OC水平及ALP活力在原基础上进一步升高，与对照组相比，差异显著（P〈0.05）。结第18代细胞在rhBMP-2的诱导下，分泌的OC水平及ALP活力在原基础上升高，与对照组相比，差异不显著（P〉0．05）；随培养时间的延长，各组细胞数量均有所增加，rhBMP-2诱导组与对照组细胞无显著性差异（P〉0．05）。细胞的传代次数对细胞增殖无明显影响（P〉0．05）。结论：rhBMP-2对细胞增殖无影响。随着传代次数的增加，骨髓基质干细胞的成骨能力下降，rhBMP-2促进其成骨的能力亦下降。