颈椎三维有限元模型的建立及意义

目的 :建立颈椎 (C4～C7)三维有限元模型 ,以期应用于临床实验研究。方法 :根据正常中年女性CT与CT重建片 ,采用CAD数据处理技术 ,输入相关的材料特性 ,构建C4～C7三维有限元模型。模型包括颈C4～C74个椎体、C4 / 5～C6 / 73个椎间盘以及后部结构与主要的 5条韧带。共 2 178个三维固体 2 0节点有限元结构。在1 8Nm作用力下 ,观察节段运动与力 位移反应。对比国内外的实验结果进行检验。结果 :生物力学实验结果与以往实验模型结果基本相符。结论 :所建立的颈椎三节段有限元模型可以模拟颈椎生物力学实验。     

Identifying women with severe angiographic coronary disease

Abstract. Kreatsoulas C, Natarajan MK, Khatun R, Velianou JL, Anand SS (McMaster University; CARING Network, McMaster University; Population Health Research Institute, McMaster University and Hamilton Health Sciences; Interventional Cardiology, Hamilton Health Sciences; Eli Lilly Canada–May Cohen Chair in Women's Health, McMaster University; Michael G. DeGroote‐Heart and Stroke Foundation of Ontario Chair in Population Health Research, McMaster University; Population Genomics Program, McMaster University; McMaster University, Hamilton, ON, Canada). Identifying women with severe angiographic coronary disease. J Intern Med 2010; 268 :66–74. Objectives. To determine sex/gender differences in the distribution of risk factors according to age and identify factors associated with the presence of severe coronary artery disease (CAD). Design. We analysed 23 771 consecutive patients referred for coronary angiography from 2000 to 2006. Subjects. Patients did not have previously diagnosed CAD and were referred for first diagnostic angiography. Outcome measures. Patients were classified according to angiographic disease severity. Severe CAD was defined as left main stenosis ≥50%, three‐vessel disease with ≥70% stenosis or two‐vessel disease including proximal left anterior descending stenosis of ≥70%. Univariate and multivariate logistic regression was used to assess the association between risk factors and angina symptoms with severe CAD. Results. Women were less likely to have severe CAD (22.3% vs. 36.5%) compared with men. Women were also significantly older (69.8 ± 10.6 vs. 66.3 ± 10.7 years), had higher rates of diabetes (35.0% vs. 26.6%), hypertension (74.8% vs. 63.3%) and Canadian Cardiovascular Society (CCS) class IV angina symptoms (56.7% vs. 47.8%). Men were more likely to be smokers (56.9% vs. 37.9%). Factors independently associated with severe CAD included age (OR = 1.05; 95% CI 1.05–1.05, P < 0.01), male sex (OR = 2.43; CI 2.26–2.62, P < 0.01), diabetes (OR = 2.00; CI 1.86–2.18, P < 0.01), hyperlipidaemia (OR = 1.50; CI 1.39–1.61, P < 0.01), smoking (OR = 1.10; CI 1.03–1.18, P = 0.06) and CCS class IV symptoms (OR = 1.43; CI 1.34–1.53, P < 0.01). CCS Class IV angina was a stronger predictor of severe CAD amongst women compared with men (women OR = 1.82; CI 1.61–2.04 vs. men OR = 1.28; CI 1.18–1.39, P < 0.01). Conclusions. Women referred for first diagnostic angiography have lower rates of severe CAD compared with men across all ages. Whilst conventional risk factors, age, sex, diabetes, smoking and hyperlipidaemia are primary determinants of CAD amongst women and men, CCS Class IV angina is more likely to be associated with severe CAD in women than men.     

Primary cardiac lymphoma masquerading as right atrial myxoma causing complete heart block—a case report

Secondary involvement of the heart and pericardium by systemic lymphoma is well documented. Primary Cardiac lymphomas (PCL) are extremely rare. Incidence of PCL is increasing in immunocompromised patients. However PCL in immunocompetent is much rarer. We report such a case of PCL in an immunocompetent elderly female masquerading as right atrial myxoma causing complete heart block which was surgically debulked successfully. Her rhythm resumed to Sinus rhythm following surgical debulking. Immunohistochemistry of the excised tumour revealed Diffuse Large B cell lymphoma. With combination chemotherapy, she is symptom free on six months follow up.     

Parotid lipoblastoma in a child: Rare presentation as huge infratemporal mass with cervical extension

Lipoblastomas arising within the parotid gland and extending into the infratemporal fossa are very rare. They are common in children <3 years of age. Access to the tumour requires careful planning and interpretation of imaging studies. Lipoblastomas tend to recur. Meticulous dissection of the tumour is needed to prevent recurrence. By adopting the appropriate approach, complete removal is possible with minimal morbidity.     

The PtdIns 3-Kinase/Akt Pathway Regulates Macrophage-Mediated ADCC against B Cell Lymphoma

Macrophages are important effectors in the clearance of antibody-coated tumor cells. However, the signaling pathways that regulate macrophage-induced ADCC are poorly defined. To understand the regulation of macrophage-mediated ADCC, we used human B cell lymphoma coated with Rituximab as the tumor target and murine macrophages primed with IFNγ as the effectors. Our data demonstrate that the PtdIns 3-kinase/Akt pathway is activated during macrophage-induced ADCC and that the inhibition of PtdIns 3-kinase results in the inhibition of macrophage-mediated cytotoxicity. Interestingly, downstream of PtdIns 3-kinase, expression of constitutively active Akt (Myr-Akt) in macrophages significantly enhanced their ability to mediate ADCC. Further analysis revealed that in this model, macrophage-mediated ADCC is dependent upon the release of nitric oxide (NO). However, the PtdIns 3-kinase/Akt pathway does not appear to regulate NO production. An examination of the role of the PtdIns 3-kinase/Akt pathway in regulating conjugate formation indicated that macrophages treated with an inhibitor of PtdIns 3-kinase fail to polarize the cytoskeleton at the synapse and show a significant reduction in the number of conjugates formed with tumor targets. Further, inhibition of PtdIns 3-kinase also reduced macrophage spreading on Rituximab-coated surfaces. On the other hand, Myr-Akt expressing macrophages displayed a significantly greater ability to form conjugates with tumor cells. Taken together, these findings illustrate that the PtdIns 3-kinase/Akt pathway plays a critical role in macrophage ADCC through its influence on conjugate formation between macrophages and antibody-coated tumor cells.     

The Nutritional Prevention of Cancer: 400 Mcg Per Day Selenium Treatment

Nonexperimental studies suggest that individuals with higher selenium (Se) status are at decreased risk of cancer. The Nutritional Prevention of Cancer (NPC) study randomized 1,312 high-risk dermatology patients to 200-mcg/day of Se in selenized yeast or a matched placebo; selenium supplementation decreased the risk of lung, colon, prostate, and total cancers but increased the risk of nonmelanoma skin cancer. In this article, we report on a small substudy in Macon, GA, which began in 1989 and randomized 424 patients to 400-mcg/day of Se or to matched placebo. The subjects from both arms had similar baseline Se levels to those treated by 200 mcg, and those treated with 400-mcg attained plasma Se levels much higher than subjects treated with 200 mcg. The 200-mcg/day Se treatment decreased total cancer incidence by a statistically significant 25%; however, 400-mcg/day of Se had no effect on total cancer incidence.     

Preysyrinx state and shunt dysfunction: an under recognized entity?

Presyrinx state is a relatively recently recognized condition. Prompt identification of this condition and appropriate treatment leads to reversal of the radiological and clinical findings with a good prognosis. Failure to identify this condition in a timely fashion leads to fully established syringomyelia. To date, presyrinx state has not been described as a feature of shunt dysfunction. One such rare case is being reported. A 14-year-old boy who was shunted for postmeningitic hydrocephalus at the age of 2 years and subsequently underwent shunt revision presented for routine follow-up and was found to have shunt dysfunction. CT scan showed panventriculomegaly and MRI studies showed panventriculomegaly with a “presyrinx” state extending from the fourth ventricle up to the thoracic region. Shunt revision led to prompt radiological reversal of the presyrinx state. This case is being reported to highlight the hitherto unreported association of shunt dysfunction and presyrinx state. The literature on presyrinx state is being reviewed with reference to the 20 cases reported earlier.     

An assessment of the construct validity of the descriptive system for the ICECAP capability measure for older people

BACKGROUND: The index of capability (ICECAP) was developed using in-depth interviews with 40 older people and comprises five attributes: attachment, security, enjoyment, role and control. This paper explores the construct validity of these five capability attributes. METHODS: An interview survey was conducted with individuals aged 65 and over located across the UK. Data were analysed in six categories (socio-demographic variables and general well-being, contact with others, health, nature of the locality and environment, social support and participation) using chi-squared tests (for categorical variables) or one-way analysis of variance (for continuous variables). RESULTS: About 315 individuals were interviewed (response rate 66%). Relationships were generally as anticipated with, for example: strong relationships between age and capability and well-being and capability, but no relationships between capability and either sex or social class; strong relationships between physical measures of health and role, enjoyment and control, and between mental health measures and attachment and enjoyment. CONCLUSIONS: This study provides some early evidence for the construct validity of the ICECAP measure. Where anticipated relationships were not observed this might in part be explained in that the ICECAP index asks about capability, but the factors with which associations were examined were largely and inevitably measures of function.     

Atlanto-axial rotatory fixation: Improved demonstration using spiral CT

Atlanto-axial rotatory fixation (AARF) is an uncommon condition which is often missed at presentation because of its rarity and the relative subtlety of plain film X-ray findings, but early detection and appropriate management are vital for a cure. We describe three cases in which the use of spiral computed tomography scanning with 3D and sagittal reconstructions greatly aided diagnosis and management. The 3D images gave a more graphic picture of the overall alignment of the upper cervical spine and the skull base, while the sagittal reconstructions demonstrated the presence or absence of compensatory atlanto-occipital subluxation. The literature is briefly reviewed.