Relationship between severity of lumbar disc disease and disability scores in sciatica patients

OBJECTIVE: To study the association between the clinical examination and the radiological assessment of lumbar disc disease in patients with sciatica. METHODS: The study included 394 consecutive sciatica patients. The patients' disabilities were evaluated by a visual analog pain scale, the Prolo functional-economic rating scale, the modified Roland-Morris disability questionnaire, and the health-related quality of life short form (SF-36) questionnaire. Radiological imaging findings were independently classified according to the Modic criteria into five groups of increasing severity of disc disease. Stepwise multivariate logistic regression was used to determine which scores were significant independent predictors of a severe disc disease (extrusion or sequestration). RESULTS: Of these patients, 9.6% had no disc disease, 3.3% had a bulging, 11.4% had a protrusion, 68.5% had an extrusion, and 7.1% had a disc sequestration. Statistically significant positive linear associations with the severity of disc disease were found for the leg pain scale, the Roland-Morris and Prolo disability scales, and the SF-36 scores related to physical functioning, physical role, and bodily pain (all P < 0.005). A poor (<5) Prolo score (odds ratio, 2.91; 95% confidence interval, 1.74-4.87), a higher leg pain score (odds ratio, 1.16 per centimeter increase; 95% confidence interval, 1.07-1.27), and a lower low back pain score (odds ratio, 0.90 per centimeter decrease; 95% confidence interval, 0.82-0.98) were retained in the multivariate logistic model as independent predictors of severe disc disease. CONCLUSION: The positive correlation between disability status and imaging findings validates both assessment methods. Routine use of disability scores brings a useful contribution to the assessment of sciatica patients.     

Low-grade pure and mixed cerebral astrocytomas treated in the CT scan era

Summary From 1974 to 1992, 63 patients diagnosed with low-grade pure or mixed oligo-astrocytoma were seen and treated at our institution. All patients underwent CT scan pre-operatively. There were 20 female and 43 males ranging in age from 12 to 73 years (median age of 33 years). 15 patients had a stereotactic biopsy as the only surgical procedure. 34 had a partial tumor resection and 14 a gross total tumor resection.43 patients were treated with post-operative radiotherapy whereas 20 patients underwent surgery only as part of the initial management. 50 to 60 Gy (median 59.4 Gy) were given with daily fractions of 1.8 to 2 Gy. Tumor volume ranged from 3.4 to 441 cm³. Median tumor volume was larger for radiotherapy treated patients.Median follow-up was 54 months (range of 4 to 240 months). The overall 10 and 15 actuarial survival rates were 37% and 25% respectively. The 5 year survival rate for patients treated at initial diagnosis with surgery alone was 66% and it was 67.3% for patients treated with radiation therapy (P = NS). Prognostic factors having independant significant impact on survival were: extent of surgery, age, gender and tumor volume.As well, survival for patients with low-grade astrocytoma in the CT scan era appears to be improved compared to historical controls in the literature.     

Allocation of health care resources in the neonatal and perinatal area �CCPS Symposium 1996

There have been publically expressed concerns about the costs and allocation of neonatal and perinatal health care resources in Canada and elsewhere for the past 15 years. This paper reports information from a symposium held during the 1996 Canadian Paediatric Society (CPS) annual meeting sponsored by the CPS Section on Perinatal Medicine. Experts in perinatal epidemiology, health care economics, public policy and finance, and consumer perspectives on the outcomes of neonatal and perinatal intensive care explored the following questions: How should the need for health care resources in the neonatal and perinatal area be objectively determined? When there are competing needs between the maternal-newborn area and other areas, how should these be rationalized? What evidence should be used (or should be available) to support the present use of resources? What evidence should be available (or is needed) to change or introduce new uses of resources? The conclusions indicated that there are no generally accepted methods to determine the allocation of health care resources but that considerations need to include population characteristics, desired outcomes, achievable results, values, ethics, legalities, cost-benefit analyses and political objectives. Information from families and adolescents who required the use of high technology and/or high cost programs will contribute individual, family and societal values that complement cost-efficacy analyses.     

Static compressive loading reduces the mRNA expression of type II and X collagen in rat growth-plate chondrocytes during postnatal growth

The mechanisms by which chondrocytes modulate longitudinal bone growth are not well understood. This in vitro study investigated the effects of loading on the mRNA expression pattern of key molecular components of the growth-plate related to the extracellular matrix (type II and type X collagen) and the PTH-PTHrP feedback loop. Short-term static compressive loading was applied to rat proximal tibial growth-plate explants. Four age groups at specific developmental stages were investigated. The spatial variation in the mRNA expression was compared among loaded explants, their contralateral sham controls, and uncultured growth plates from normal animals. Basic cell metabolism (18S rRNA) was unaffected by load. Results indicated a narrower spatial distribution of mRNA expression of type II collagen throughout the growth plate; similarly, a narrowed distribution of expression of type X collagen was noted in the lower hypertrophic zone of the growth-plate. This suggests that mechanical compression influences chondrocytes of the hypertrophic zone to alter their expression of specific genes encoding proteins of the extracellular matrix, while PTH-PTHrP receptor mRNA, a regulatory protein, remained unaffected by loading. The effects of compression were similar at the different stages of growth, suggesting that additional factors may be involved in the clinical progression of skeletal deformities observed during growth spurts. Although this study was done in vitro and limited to static loading, it furthers our understanding of growth-plate mechanobiology as a first step toward providing a scientific rationale for treating progressive musculoskeletal deformities.     

Intra-stride belt-speed variation affects treadmill locomotion

For overground and treadmill locomotion to be mechanically similar, it is required that the belt speed of the treadmill is constant and the same to that of overground locomotion. Variation of the belt speed during a stride causes exchange of energy between the subject and the treadmill. This might be the cause of different kinematic patterns between overground and treadmill locomotion, which have been reported in literature. The aim of this study was to investigate whether the intra-stride belt-speed is variable, and whether differences in kinematic patterns can be attributed to these variations. Nine subjects walked and ran overground and on two treadmills that were differently susceptible to subjects' braking and accelerating forces. It was found that the speed variations during treadmill locomotion affect the kinematic parameters significantly. The amount of intra-stride belt-speed variation was found to depend on the power of the treadmill and the mass of the subject. Copyright 1998 Elsevier Science B.V.     

Immune responses against SARS-coronavirus nucleocapsid protein induced by DNA vaccine

The nucleocapsid （N） protein of SARS-coronavirus （SARS-CoV） is the key protein for the formation of the helical nucleocapsid during virion assembly. This protein is believed to be more conserved than other proteins of the virus, such as spike and membrane glycoprotein. In this study, the N protein of SARS-CoV was expressed in Escherichia coli DHSalpha and identified with pooled sera from patients in the convalescence phase of SARS. A plasmid pCI-N, encoding the full-length N gene of SARS-CoV, was constructed. Expression of the N protein was observed in COS1 cells following transfection with pCI-N. The immune responses induced by intramuscular immunization with pCI-N were evaluated in a murine model. Serum anti-N immunoglobutins and splenocytes proliferative responses against N protein were observed in immunized BALB/c mice. The major immunoglobulin G subclass recognizing N protein was immunoglobulin G2a, and stimulated splenocytes secreted high levels of gamma interferon and IL-2 in response to N protein. More importantly, the immunized mice produced strong delayed-type hypersensitivity （DTH） and CD^8＋ CTL responses to N protein.     

人工神经元网络用于复方氯丙嗪的含量测定

将误差反向传播(BP)的人工神经元网络(ANN)模型，用于复方氯丙嗪紫外重叠光谱分 析。对ANN模型的参数进行了优化。采用f(x)二1/(1+e^-x)作为网络节点的输入输出转换函数的三 层神经网络具有较佳性能，当取隐含节点数为15时，该网络预测结果的最小平均相对误差为1.22％， 将研制的ANN模型用于复方氯丙嗪含量测定，其结果与药品标准法和偏最小二乘法(PLs)一致。