应用三维有限元法评估聚甲基丙烯酸甲酯和磷酸钙骨水泥铸件的力学特征

目的:聚甲基丙烯酸甲酯和磷酸钙骨水泥作为经皮椎体后凸成形术填充物,应用三维有限元分析法比较两种材料治疗骨质疏松性椎体压缩骨折的生物学效应。方法:实验于2003-03/09在南通医学院第一附属医院骨科和上海大学上海生物力学工程研究所合作完成。①利用WD-5型万能材料机测量聚甲基丙烯酸甲酯和磷酸钙骨水泥铸件力学性质。②选取骨质疏松患者1例(患者知情同意),排除其他疾患,应用CT扫描技术、图形数字化方法获取胸腰段的三维坐标,利用ANSYS5.0有限元分析软件等工具建立骨质疏松患者胸腰段的三维有限元模型。③模拟L1经皮椎体后凸成形术,对其和相邻椎体及椎间盘的负荷传递、应力、位移等进行分析。结果:①获取了精确的T11￣L3的多排螺旋CT扫描断层影像数据,经ANSYS5.0软件处理后得到4718个节点,1642个薄极单元,4495个八节点等参单元的骨质疏松患者胸腰段三维有限元力学模型。②采用聚甲基丙烯酸甲酯作为经皮椎体后凸成形术的填充物,比骨质疏松椎体应力增加了近15%。后部结构的应力平均增加13.2%,其中椎弓根增加5.9%,峡部增加6.25%,关节点增加27.6%。聚甲基丙烯酸甲酯在稳定椎体、恢复强度和刚度的同时,可能使其后部结构及相邻腰椎出现应力集中现象。③采用磷酸钙骨水泥作为椎体成形术填充物,比骨质疏松椎体应力平均增加了7%,应力集中现象明显小于聚甲基丙烯酸甲酯。结论:三维有限元力学分析表明两种材料均提高了椎体的抗变形能力,有利于椎体功能的重建。与聚甲基丙烯酸甲酯相比,磷酸钙骨水泥能减少成形椎体和相邻椎体之间的应力梯度,从长远看,能减少椎体退变和相邻椎体骨折的机会。     

Detection of exercise-induced ischemia by changes in B-type natriuretic peptides

OBJECTIVES: The purpose of this study was to examine the effect of exercise-induced ischemia on levels of B-type natriuretic peptide (BNP) and its inactive N-terminal fragment (NT-pro-BNP)and to determine whether measurement of these peptides can improve the diagnostic accuracy of exercise testing. BACKGROUND: The ability of exercise testing to detect coronary artery disease (CAD) is limited by modest sensitivity and specificity. B-type natriuretic peptides (NT-pro-BNP and BNP) are released by ventricular myocytes in response to wall stress. We hypothesized that exercise-induced ischemia results in increased wall stress and triggers release of NT-pro-BNP and BNP. METHODS: A total of 74 patients with known CAD, normal left ventricular function, and normal resting levels of NT-pro-BNP and BNP who were referred for exercise testing with radionuclide imaging, and 21 healthy volunteers, were enrolled. Blood was drawn before and after maximal exercise and analyzed for NT-pro-BNP and BNP. RESULTS: Of the patients with CAD, 40 had ischemia on perfusion images and 34 did not. Median post-exercise increases in NT-pro-BNP and BNP (DeltaNT-pro-BNP and DeltaBNP) were approximately four-fold higher in the ischemic group than in the nonischemic group (DeltaNT-pro-BNP 14.5 vs. 4 pg/ml, p < 0.0001; DeltaBNP 36.5 vs. 7.5 pg/ml, p < 0.0001). In volunteers, median DeltaNT-pro-BNP was almost identical to that of the nonischemic patient group. At equal specificity to the electrocardiogram (ECG) (58.8%), the sensitivities of DeltaNT-pro-BNP and DeltaBNP for detecting ischemia were 90% and 80%, respectively; in contrast, the sensitivity of the exercise ECG was 37.5%. CONCLUSIONS: Measurement of exercise-induced increases in BNPs more than doubles the sensitivity of the exercise test for detecting ischemia with no loss of specificity.     

Additive Antinociception between Intrathecal Sildenafil and Morphine in the Rat Formalin Test

The possible characteristics of spinal interaction between sildenafil (phosphodiesterase 5 inhibitor) and morphine on formalin-induced nociception in rats was examined. Then the role of the opioid receptor in the effect of sildenafil was further investigated. Catheters were inserted into the intrathecal space of male Sprague-Dawley rats. For induction of pain, 50 µL of 5% formalin solution was applied to the hind-paw. Isobolographic analysis was used for the evaluation of drug interaction between sildenafil and morphine. Furthermore, naloxone was intrathecally given to verify the involvement of the opioid receptor in the antinociception of sildenafil. Both sildenafil and morphine produced an antinociceptive effect during phase 1 and phase 2 in the formalin test. The isobolographic analysis revealed an additive interaction after intrathecal delivery of the sildenafil-morphine mixture in both phases. Intrathecal naloxone reversed the antinociception of sildenafil in both phases. These results suggest that sildenafil, morphine, and the mixture of the two drugs are effective against acute pain and facilitated pain state at the spinal level. Thus, the spinal combination of sildenafil with morphine may be useful in the management of the same state. Furthermore, the opioid receptor is contributable to the antinocieptive mechanism of sildenafil at the spinal level.     

Lymphedema and quality of life in Chinese women after treatment for breast cancer

AimsTo determine the magnitude of arm symptom-associated distress and quality of life in patients suffering from lymphedema after axillary dissection for breast cancer.Design and methodsTwo hundred and two breast cancer patients were interviewed, including 101 lymphedema cases and 101 controls who were matched in terms of surgery date, axillary radiotherapy and cancer stage. The FACT-B + 4 quality-of-life instrument was used to assess breast, emotional, functional, physical, and social well-being. A self-devised Arm Symptom Distress scale was used to collect information about arm morbidities including swelling, pain, numbness or tingling, limitation of movement, infection; and their interference on daily life. Arm circumference at different levels was measured to determine the presence and severity of lymphedema. The association between lymphedema and quality of life was evaluated, controlling for patient demographics and clinical factors.ResultsCompared with controls, individuals with lymphedema had a significantly worse score on FACT-B + 4 and the Arm Symptom Distress scale. The score was significantly lower in five of the six domains of FACT-B + 4, and significantly higher in both subscales of the Arm Symptom Distress scale. Patients with severe lymphedema had a significantly worse Symptom Severity sub-score on the Arm Symptom Distress scale than those with mild lymphedema.ConclusionsAmong women who have undergone axillary dissection for breast cancer, lymphedema was associated with an inferior quality of life and a higher level of arm symptom-associated distress. Patients with severe lymphedema had more arm symptom-associated distress than those with mild lymphedema.     

The development of the modified blaylock tool for occupational therapy referral (MBTOTR): a preliminary evaluation of its utility in acute care

Purpose: Acute hospitals are facing more complex admissions with older people at increased risk of functional decline. This study aimed to create and trial the feasibility of a new screening tool designed to identify patients at risk of functional decline who need an occupational therapy referral within acute care. Method: Ten screening tools were reviewed and the Modified Blaylock Tool for Occupational Therapy Referral (MBTOTR) was developed. The MBTOTR was applied in a retrospective chart review of 50 patients over the age of 65 years who were admitted to five acute wards. Data on patients identified at risk of functional decline were compared to patients who were referred to occupational therapy. Results: Occupational therapy referrals were made by ward staff for 14 out of the 50 patients reviewed (32.5%). Only 14% (n?=?7) of patients did not require a referral. The MBTOTR identified no irrelevant occupational therapy referrals. However, 66.5% of patients identified as needing an occupational therapy referral did not get one. Conclusion: The MBTOTR identified high risk acute patients requiring an occupational therapy referral who were not referred to occupational therapy. Use of the MBTOTR would facilitate early occupational therapy referrals for complex patients, and potentially better discharge outcomes.

• Implications for rehabilitation

• The MBTOTR can be used in acute care settings to facilitate relevant occupational therapy referrals.

• Without a screening tool, many older people who should have an occupational therapy assessment may not receive a referral for occupational therapy.

• Nursing and medical staff need to use this tool to identify older people in their care who may benefit from occupational therapy assessment and intervention.

• If occupational therapy referrals can be made early, this may contribute to reducing delays to discharge plans for complex patients.

     

A Preclinical Animal Model to Assess the Effect of Pre-existing Immunity on AAV-mediated Gene Transfer

Hepatic adeno-associated virus (AAV)-serotype 2–mediated gene transfer results in sustained transgene expression in experimental animals but not in human subjects. We hypothesized that loss of transgene expression in humans might be caused by immune memory mechanisms that become reactivated upon AAV vector transfer. Here, we tested the effect of immunological memory to AAV capsid on AAV-mediated gene transfer in a mouse model. Upon hepatic transfer of an AAV2 vector expressing human factor IX (hF.IX), mice immunized with adenovirus (Ad) vectors expressing AAV8 capsid before AAV2 transfer developed less circulating hF.IX and showed a gradual loss of hF.IX gene copies in liver cells as compared to control animals. This was not observed in mice immunized with an Ad vectors expressing AAV2 capsid before transfer of rAAV8-hF.IX vectors. The lower hF.IX expression was primarily linked to AAV-binding antibodies that lacked AAV-neutralizing activity in vitro rather than to AAV capsid–specific CD8⁺ T cells.     

Small cell variant of Ki-1 lymphoma associated with myelofibrosis and a novel constitutional chromosomal translocation t(3;4) (q13;q12).

An unusual case of small cell variant of Ki-1 non-Hodgkin's lymphoma diagnosed one year after an original diagnosis of idiopathic myelofibrosis is reported. On the second occasion, the patient presented with fever, lymphadenopathy and hepatosplenomegaly. A lymph node biopsy specimen confirmed a diagnosis of small cell variant of Ki-1 lymphoma. A repeat bone marrow biopsy specimen showed myelofibrosis with no evidence of lymphomatous infiltration, but cytogenetic studies on blood, bone marrow and skin fibroblasts revealed a novel chromosomal translocation t(3,4)(q13;q12).     

Single nucleotide polymorphism in the tumor necrosis factor-alpha gene affects inflammatory bowel diseases risk

AIM： To investigate the role that single nucleotide polymorphisms （SNPs） in the promoter of the tumour necrosis factor-alpha （TNF-α） gene play in the risk of inflammatory bowel diseases （IBDs） in a New Zealand population, in the context of international studies. METHODS： DNA samples from 388 patients with Crohn＇s disease （CD）, 405 ulcerative colitis （UC）, 27 indeterminate colitis （IC） and 201 randomly selected controls, from Canterbury, New Zealand were screened for 3 common polymorphisms in the TNF-α receptor： -238 G→A, -308 G→A and -857C→T, using a TaqmanR assay. A meta-analysis was performed on the data obtained on these polymorphisms combined with that from other published studies. RESULTS： Individuals carrying the -308 G/A allele had a significantly （OR = 1.91, χ2 = 17.36, P 〈 0.0001） increased risk of pancolitis, and a 1.57-fold increased risk （OR = 1.57, χ2 = 4.34, P = 0.037） of requiring a bowel resection in UC. Carrying the -857 C/T variant decreased the risk of ileocolonic CD （OR = 0.56, χ2 =4.32, P = 0.037）, and the need for a bowel resection （OR = 0.59, χ2 = 4.85, P = 0.028）. The risk of UC was reduced in individuals who were smokers at diagnosis, （OR = 0.48, χ2 = 4.86, P = 0.028）. CONCLUSION： TNF-α is a key cytokine known to play a role in inflammatory response, and the locus for the gene is found in the IBD3 region on chromosome 6p21, known to be associated with an increased risk for IBD. The -308 G/A SNP in the TNF-α promoter is functional, and may account in part for the increased UC risk associated with the IBD3 genomic region. The -857 C/T SNP may decrease IBD risk in certain groups. Pharmaco- or nutrigenomic approaches may be desir- able for individuals with such affected genotypes.