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81.
The treatment of deep cartilage defects in load-bearing joints is a problem that still has no satisfactory solution. Full-thickness defects of the articular cartilage rarely heal spontaneously, usually leaving damage that can lead to early arthrosis. Techniques currently available for the treatment of chondral defects include abrasion, drilling, micro-fracturing, transplantation of tissue autografts and allografts, and cell transplantation. Osteochondral autograft transplantation is currently the only surgical cartilage repair technique known to lead to the formation of genuine hyaline articular cartilage and its retention at least in the medium term. The Draenert method, in which a water-cooled diamond bone-cutting system is used, is an effective procedure for resurfacing the joints affected by localised cartilaginous defects, even when there is also severe bone loss. Donor-side morbidity can be kept to a minimum by filling the defect caused by harvesting with a press-fit cylinder of cancellous bone covered with periosteum for protection.  相似文献   
82.
Adrenergic signalling between rat taste receptor cells   总被引:2,自引:0,他引:2  
In taste buds, synaptic transmission is traditionally thought to occur from taste receptor cells to the afferent nerve. This communication reports the novel observation that taste receptor cells respond to adrenergic stimulation. Noradrenaline application inhibited outward potassium currents in a dose-dependent manner. This inhibition was mimicked by the β agonist isoproterenol and blocked by the β antagonist propranolol. The α agonists clonidine and phenylephrine both inhibited the potassium currents and elevated intracellular calcium levels. Inwardly rectifying potassium currents were unaffected by adrenergic stimulation. Experiments using the RT-PCR technique demonstrate that lingual epithelium expresses multiple α (α1a, α1b, α1c, α1d, α2a, α2b, α2c) and β (β1, β2) subtypes of adrenergic receptors, and immunocytochemistry localized noradrenaline to a subset of taste receptor cells. Collectively, these data imply strongly that adrenergic transmission within the taste bud may play a paracrine role in taste physiology.  相似文献   
83.
Ischemic injury plays an important role in chronic renal transplant failure (CRTF). Down-regulation of ecto-adenosine triphosphatase (ATPase) in combination with up-regulation of ecto-5'-nucleotidase is a hallmark of ischemic injury. We studied the expression of renal ecto-5'-nucleotidase and ecto-ATPase in experimental renal transplantation. Fisher 344-to-Lewis allografted rats were either treated with an angiotensin-converting enzyme inhibitor (ACEi) or left untreated. Lewis-to-Lewis syngrafted rats served as controls. Untreated allografted rats developed proteinuria, glomerulosclerosis, and mild intimal hyperplasia. ACEi completely prevented focal and segmental glomerulosclerosis (FGS) and proteinuria, but significantly enhanced intimal hyperplasia. Untreated allografted rats revealed marked vascular ecto-5'-nucleotidase activity, which increased with ACEi. Vascular ecto-5'-nucleotidase activity was absent in syngrafted animals. Ecto-5'-nucleotidase activity correlated well with intimal hyperplasia. Glomerular ecto-ATPase expression was significantly reduced in untreated allografted rats compared to syngrafted rats and correlated well with the extent of FGS. ACEi prevented reduction in glomerular ecto-ATPase. We found de-novo expression of ecto-5'-nucleotidase at sites of renal intimal hyperplasia. Glomerular ecto-ATPase expression was markedly reduced in allografted rats and was prevented by ACEi. These enzyme expression patterns suggest local ischemic damage in experimental CRTF.  相似文献   
84.
目的 探讨严重创伤后肝细胞凋亡及坏死在急性肝功能障碍发病机制中的作用。方法复制多发性骨折合并休克的大鼠创伤模型,采用 Annexin-V-Flous、碘化丙锭(propidium iodid,PI)双标法经流式细胞仪检测创伤后各时间点肝细胞凋亡与坏死的数量变化,结合光镜、电镜和电泳观察细胞凋亡与坏死,并与肝功能变化相比较。结果创伤后早期肝细胞即发生凋亡和坏死,坏死肝细胞的数量进行性升高,与肝功能变化显著呈正相关;凋亡肝细胞在创伤后3h达高峰,部分凋亡肝细胞发生继发性坏死,其数量与肝功能变化显著正相关。结论肝细胞坏死与凋亡是严重创伤后肝功能损害的重要原因,坏死肝细胞是肝功能损害的直接因素,凋亡肝细胞通过发生继发性坏死加重肝功能损害。  相似文献   
85.
Contemporary discourse contains numerous examples of use of the concept of culture by social and behavioral scientists. Simple reification, where the speaker makes culture into a thing capable of action exemplifies one usage in public discourse. Some quantitative social scientists attempt to characterize people’s cultural identities by means of a single categorical variable, which often “lumps” people into categories such as “Hispanic” or “Black” that in fact have numerous culturally bounded subcategories. Approaches that emphasize cultural process are preferable to those who attempt to categorize; more complex measures of acculturation help investigators to make convincing analyses of circumstances in which health disparities occur. Examples in which investigators make appropriate use of cultural characterizations demonstrate their utility in investigating health disparities in Haitian American women, injecting and noninjecting drug users, Hispanic youth, and adult Hispanics at risk of HIV infection. Focus on culture in the study of health disparities can identify entanglements between structural factors such as poverty and lack of education and cultural factors such as beliefs about health. Qualitative methods coupled with quantitative methods have great potential to improve investigators’ grasp of cultural nuance while capturing the distribution of qualitatively derived behaviors.  相似文献   
86.
随着工业化进程的加速及交通事故的增加,胸部创伤日渐增多。国内报道在45 569例创伤中,胸部创伤占1·47%[1],其中肋骨骨折非常常见。随着螺旋CT检查临床应用日趋广泛,其高敏性、快速成像的特性及强大的后处理功能越来越在肋骨骨折中显现重要作用。本文对53例肋骨骨折患者的16层  相似文献   
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89.
The specific characteristics of genetic data lead to ethical-legal conflicts in the framework of genetic diagnosis. Several international organisations, including UNESCO and the Council of Europe, have enacted rules referring to the use of genetic information. This paper discusses possible legal and ethical criteria that could be used in genetic testing.  相似文献   
90.
38例视网膜母细胞瘤的临床和误诊分析   总被引:1,自引:0,他引:1  
目的 探讨视网膜母细胞瘤(retinoblastoma,RB)的临床特征、病理分类和误诊原因,尽可能减少错误的临床诊治。方法 对我科于1999-2004年间收集的38例临床诊断为视网膜母细胞瘤(retinoblastoma,RB)的病例资料进行回顾性分析。结果在38例疑似病例中,34例病理诊断为视网膜母细胞瘤,4例为Coats病。结论掌握相关的影像学知识和综合分析疑难病例的临床资料将有助于视网膜母细胞瘤的正确诊断和处理。  相似文献   
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