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Management of benign and malignant diseases of the pancreas, liver, and biliary tract has made remarkable progress in the last two decades. Advances in minimally invasive surgery, interventional radiology, and diagnostic and therapeutic endoscopy have changed the treatment of common diseases such as cholelithiasis and more serious diseases such as pancreatic adenocarcinoma. Advances in biliary tract and pancreatic surgery have paralleled the advances in ultrasonographic imaging, CT, and MR imaging. This article outlines the surgeon's perspective on radiologic imaging and preoperative staging of benign and malignant biliary and pancreatic disease.  相似文献   

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自噬是真核生物中一种高度保守的胞内降解途径.其主要通过溶酶体或液泡进行饥饿状态下的营养动员,清除受损蛋白质、细胞器和胞内病原体.自噬主要包括巨自噬、分子伴侣介导自噬(CMA)和微自噬.自噬已被证实与多种人类疾病相关,其在肿瘤发生发展中具有重要意义.近年研究中,对于自噬和肿瘤关系有了进一步的认识,该文就自噬分子机制、调控通路以及与肿瘤发生发展关系的研究进展作一综述.  相似文献   

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The aim was to give a systematic presentation of physiologic and pathologic calcifications and ossifications in the face and neck with a special emphasis on clinical relevance. In a sometimes subacute setting one should recognize specific calcifications which often lead to important diagnoses such as fungal sinusitis or sclerosing labyrinthitis. In a more chronic situation intraocular calcifications in small children are pathognomonic for retinoblastoma. Juxtatumoral sclerosis of the laryngeal cartilage in laryngopharyngeal carcinoma is usually caused by tumor infiltration of the cartilage resulting in a higher tumor stage and, this way, has a major impact on the therapeutical strategy. Calcified lymph nodes are mainly unspecific but can be the result of tuberculosis or metastases of thyroid cancer. Cross-sectional imaging methods, most of all computed tomography, are ideally suited to reveal head and neck calcifications and ossifications, especially those which are clinically relevant.  相似文献   

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Thyroid imaging approach is based on the preliminary clinical evaluation. Lesions that are smaller than 2 cm should be assessed with US, which is capable of discriminating masses as small as 2 mm and distinguishing solid from cystic nodules. US-guided FNAB provides tissue for cytologic examination of thyroid nodules. CT and MR imaging are indicated for larger tumors (greater than 3 cm diameter) that extend outside the gland to adjoining structures, including the mediastinum, and retropharyngeal region. Metastatic lymph nodes in the neck and invasion of the aerodigestive tract are also in the realm of CT and MR imaging. Thyroid nodules are categorized on scintigraphy as hot or cold nodules. Hot nodules are rarely malignant, whereas cold nodules have an incidence of 10% to 20% of malignancy. Calcifications (amorphous, globular, nodular, and linear) occur in adenomas and carcinomas and have no differential diagnostic features except for psammomatous calcifications, which are a pathognomonic finding in papillary carcinomas and a small percentage of medullary carcinomas. Papillary carcinoma is the most common malignant tumor (80%) followed by follicular (20% to 25%); medullary (5%); undifferentiated; anaplastic carcinomas (< 5%); lymphoma (5%); and metastases. Lymph node metastases are common in papillary carcinoma, 50% at presentation, and less common in follicular carcinomas. The metastatic nodes in papillary carcinoma may enhance markedly (hypervascular); show increased signal intensity on T1-weighted images (increased thyroglobulin content or hemorrhage); and reveal punctate calcifications. Localized invasion of the larynx, trachea, and esophagus occurs predominantly in papillary and follicular carcinomas; the incidence is less than 5%. Ectopic thyroid tissue may be encountered in the tongue (foramen cecum); along the midline between posterior tongue and isthmus of thyroid gland; lateral neck; mediastinum; and oral cavity. Goiter and malignant tumors, notably papillary carcinoma, may develop in ectopic thyroid tissue. Carcinomas may also arise in thyroglossal duct cysts, which develop from duct remnants between the foramen cecum and thyroid isthmus. Infectious disease of the thyroid gland is not common and the CT and MR imaging findings are similar as described under neck infection. Other types of inflammatory disorders including Hashimoto's thyroiditis, granulomatous thyroiditis, and Riedel's struma display no specific imaging features. Imaging studies may, however, be indicated to confirm a suspected clinical diagnosis and assess compromise of the airway (Riedel's struma). HPT is a clinical diagnosis in which hypercalcemia is the most important finding. Parathyroid hyperplasia, adenoma, and carcinoma represent underlying lesions. To relieve the patient's symptoms surgical extirpation is indicated. The surgical success rate without imaging is 95%. The indications for imaging studies vary but it is generally agreed that reoperation after a previous failed surgical attempt and suspicion of an ectopic parathyroid adenoma should be investigated by imaging. These consist of US, nuclear medicine studies, CT and MR imaging. US and technetium sestamibi scanning have the highest accuracy rate for localizing an adenomatous gland at and near the thyroid gland. Ectopic adenomas, particularly if they are located in the mediastinum, are preferrably investigated with CT and MR imaging with gadolinium and fat suppression. Carcinomas and parathyroid cysts are optimally evaluated by CT and MR imaging. On MR imaging adenomas are low in signal intensity on T1-weighted images, high in signal intensity on T2-weighted images, and enhance post introduction of gadolinium.  相似文献   

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This article discusses the imaging manifestations of infectious and inflammatory conditions of the head and neck. Special attention is paid to the sites, routes of spread, and complications of neck infections. Because the clinical signs and symptoms and the complications of these conditions are often determined by the precise anatomic site involved, anatomic considerations are stressed. Familiarity with the fascial layers, spaces of the neck, and the contents of each space is helpful for this discussion. The fascial layers of the neck are important barriers to infection, and once infection is established, the fascial layers play a part in directing its spread.  相似文献   

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目的:分离纯化幽门螺杆菌分泌和重组表达的细胞空泡毒素抗原( VacA)蛋白,并评价其致细胞空泡效应及致细胞凋亡效应。方法分别从幽门螺杆菌ATCC26695菌株培养上清和重组表达VacA蛋白的pQE30-VacA-E.coliM15基因工程菌中分离纯化VacA蛋白,经酸化后,以不同终浓度(5,10 ng/ml)分别与人胃腺癌AGS细胞共孵24 h,观察致空泡效应,并通过流式细胞术检测细胞凋亡。结果成功分离纯化出幽门螺杆菌分泌和重组表达的VacA蛋白;幽门螺杆菌分泌的VacA蛋白能显著引起AGS细胞的空泡样改变及凋亡(P<0.01),而重组表达的VacA蛋白致细胞空泡样改变及凋亡不显著( P>0.05)。结论幽门螺杆菌分泌的VacA蛋白有良好的空泡毒性及致凋亡效应,而重组表达的VacA蛋白无致空泡及凋亡效应,幽门螺杆菌分泌的VacA蛋白可用于VacA作用机制的研究。  相似文献   

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化学武器公约( CWC)和生物武器公约( BWC)是为禁止生产、发展、储存和使用化学武器和生物武器而制定的国际公约。近年来,科学技术快速发展,知识交叉渗透,学科之间出现整合和融合,促进了科技进步和经济发展。其中化学和生物学融合在有力促进制药、健康卫生、绿色化学和环境保护等产业进步的同时,也对化学和生物武器公约的履约产生了重要的影响。该文综述了与化学武器和生物武器公约相关的化学和生物学融合进展,并分析其对公约履约的影响。  相似文献   

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M E Hansen  S Kadir 《Der Radiologe》1990,30(7):331-336
Twenty-one embolizations were performed in 19 children and adolescents. Ten patients underwent emergency embolotherapy to control bleeding from trauma (5), neoplastic disease (2), mycotic aneurysm (1), post-operative bleeding (1), and hemoptysis (1). Nine patients underwent elective embolotherapy. In 5 patients with hypervascular tumors, it was performed as an adjunct to surgery or chemotherapy. In 3 patients, embolotherapy was the primary mode of treatment for vascular malformations in the lung, pelvis, and kidney. One patient with systemic-pulmonary arterial collaterals was treated for high-output congestive heart failure. Embolotherapy was successful in controlling bleeding in all cases. There were no major complications or procedure-related mortalities. Minor complications occurred in 2 patients. Our results indicate that percutaneous transcatheter embolotherapy in children and adolescents is safe and effective and has wide application in both elective and emergency management of vascular lesions in this age group.  相似文献   

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The purposes of this study were to compare the total metabolic costs and gait patterns of walking and running at self-selected, comfortable speeds in males and females. Total oxygen consumption was used to determine the metabolic cost, and cinematographic analysis was used to study the gait patterns of walking and running a distance of 1 km in 12 male and 12 female subjects. No significant sex difference was observed for the speed, vertical lift per stride, and total vertical lift per km of distance walked. Females ran at a significantly slower speed than males (P less than .01), but no significant sex difference was observed for the vertical lift per stride or total vertical lift per km of distance run. In both sexes, the gross and net energy costs of running were significantly greater (P less than .001) than those of walking when values were expressed as kcal . kg-1 . km-1 or cal . kg-1 . stride-1. No significant sex difference was observed in the gross or net metabolic cost of walking, whereas during running, the gross and net metabolic costs in kcal . kg-1 . km-1 were significantly higher (P less than .05) in females than in males. It was hypothesized that this sex difference was due to the cumulative effect of several factors which were biomechanical and metabolic in nature.  相似文献   

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This study evaluated if the ventilatory response to exercise is impaired by the cramp position of rowing. Maximal oxygen uptake (VO2max), maximal expiratory volume (VEmax), and maximal heart rate (HRmax) during rowing and running were compared in 55 males (age, mean +/- SD, 21 +/- 3 years; height 176 +/- 5 cm; body mass 72 +/- 6 kg) and 18 females (age 20 +/- 2 years; height 164 +/- 5 cm; body mass 61 +/- 4 kg). VEmax was larger during rowing than during running (males, 157 +/- 16 vs. 147 +/- 13 L min(-1); 114 +/- 9 vs. 105 +/- 11 L min(-1), P<0.01). Also VO2max was larger during rowing than during running (males, 4.5 +/- 0.5 vs. 4.3 +/- 0.4 L min(-1); females, 3.3 +/- 0.4 vs. 3.2 +/- 0.4 L min(-1), P<0.01). However, HRmax was lower during rowing than during running (males, 194 +/- 8 vs. 198 +/- 11 beats min(-1); females, 192 +/- 6 vs. 196 +/- 8 beats min(-1), P<0.05). VEmax was correlated to body mass and fat-free mass, as was VO2max. Thus, the oxygen pulse (VO2max/HRmax) was larger during rowing than during running, while the ventilatory equivalent for oxygen (VEmax/VO2max) was similar. We showed that bending the body during rowing does not seem to impair ventilation either in males or in females. The results indicate that VEmax and VO2max relate to body size and fat-free mass for both females and males. The findings indicate that the involvement of more muscles, the entrainment, and the body position during rowing facilitates ventilation and venous return and lowers maximal heart rate.  相似文献   

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Exercise and self-esteem: rationale and model   总被引:8,自引:0,他引:8  
Positive emotional and psychological benefits are commonly believed to result from chronic physical exercise. While reviews of research have failed to substantiate this general proposition, they have identified enhanced self-esteem as an empirically supported exercise outcome. Unfortunately, research in this area has tended to be simplistic in self-esteem theory and measurement and has remained incapable of addressing how or why change may occur. This paper summarizes pertinent self-esteem theory and presents an empirically based rationale for self-esteem enhancement through exercise participation. It constructs a model for examining exercise and self-esteem interactions in which components of self-structure are hierarchically organized on a basis of generality. The self-esteem model contains dimensions of competence and self-acceptance, and it is operationally defined.  相似文献   

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For patients with disabling foot or ankle pain, medical or surgical treatment decisions can be difficult to make when multiple joints show changes of osteoarthritis or if the patient's pain clinically is related to a joint or tendon that is normal by other imaging studies. For these patients, injection of anesthetic, steroid, or both, into joints or tendon sheaths of the foot and ankle provides important diagnostic information and therapeutic relief. Diagnostic injections may show that the joints noted by other imaging studies have osteoarthritis that are not responsible for a patient's pain or that a normal joint is responsible. When multiple joints show changes of arthritis, anesthetic injections can help decide which and how many joints could benefit from surgical arthrodesis. Relief of pain after anesthetic joint injection correlates well with postoperative pain relief subsequent to arthrodesis. This article discusses the indications and the contraindications for performing diagnostic and therapeutic joint injections, and also presents the techniques for performing these studies.  相似文献   

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