Quantifying arbitrary magnetic susceptibility distributions with MR.

Magnetic susceptibility, as a physical property of materials, plays important roles in many physical, chemical, engineering, and medical applications. Its quantification becomes of significant interest when MRI becomes a commonly used technique in biomedical applications. A general method is presented here for quantifying arbitrary magnetic susceptibility distributions in a localized region on the basis of first principles of magnetic induction field distributions in space. A proof of the concept was demonstrated by computer simulations. The study establishes the methodological basis for quantitative magnetic susceptibility imaging with MR.     

造影剂到达腹主动脉的峰值大小与患者因素的关系

目的探讨造影剂到达腹主动脉的峰值大小与患者因素之间的关系。方法108例患者以2.5ml/s注射欧乃派克(300mgI/ml)20ml,12s后采用testbolus技术在腹腔干水平同层动态扫描腹主动脉,用dynamic evaluation软件测得腹主动脉的峰值大小,采用单因素回归分析和多因素逐步回归分析法研究患者的性别、年龄、身高、体重、心率、血压、注射位点、达峰时间及是否有心脏病、糖尿病、或化疗史对造影剂到达腹主动脉峰值大小是否有影响及影响程度。结果造影剂到达腹主动脉峰值大小,在男性平均比女性低;其随年龄、身高、体重、达峰时间的增加而逐渐降低,注射位点在手背静脉其值平均比在肘部静脉低;其不受心率、血压、是否有心脏病、糖尿病或化疗史的影响。参考公式:峰值大小(HU)=383.8400-身高(cm)×1.0909-体重(kg)×0.6760 注射位点×16.7878-达峰时间(s)×1.6882。结论可根据患者的性别、年龄、身高、体重、注射位点和达峰时间来适当调整患者CT血管成像时造影剂用量。     

Nocturnal hypoglycaemia in Type 1 diabetic patients,assessed with continuous glucose monitoring: frequency,duration and associations

Aims We quantified the occurrence and duration of nocturnal hypoglycaemia in individuals with Type 1 diabetes treated with continuous subcutaneous insulin infusion (CSII) or multiple‐injection therapy (MIT) using a continuous subcutaneous glucose sensor. Methods A microdialysis sensor was worn at home by 24 patients on CSII (mean HbA_1c 7.8 ± 0.9%) and 33 patients on MIT (HbA_1c 8.7 ± 1.3%) for 48 h. Occurrence and duration of nocturnal hypoglycaemia were assessed and using multivariate regression analysis, the association between HbA_1c, diabetes duration, treatment type (CSII vs. MIT), fasting and bedtime blood glucose values, total daily insulin dose and mean nocturnal glucose concentrations, and hypoglycaemia occurrence and duration was investigated. Results Nocturnal hypoglycaemia ≤ 3.9 mmol/l occurred in 33.3% of both the CSII‐ (8/24) and MIT‐treated patients (11/33). Mean (± sd ; median, interquartile range) duration of hypoglycaemia ≤ 3.9 mmol/l was 78 (± 76; 57, 23–120) min per night for the CSII‐ and 98 (± 80; 81, 32–158) min per night for the MIT‐treated group. Multivariate regression analysis showed that bedtime glucose value had the strongest association with the occurrence (P = 0.026) and duration (P = 0.032) of nocturnal hypoglycaemia. Conclusions Microdialysis continuous glucose monitoring has enabled more precise quantification of nocturnal hypoglycaemia occurrence and duration in Type 1 diabetic patients. Occurrence and duration of nocturnal hypoglycaemia were mainly associated with bedtime glucose value.     

Integrated home monitoring predicts lead failure in a pacemaker dependent 4-year-old girl.

A 4-year-old girl with post-surgical complete atrioventricular block received an epicardial dual chamber pacemaker system. During further growth intermittent exit block occurred, first misinterpreted as neurological seizures. The epicardial lead was replaced using a transvenous approach, and a pacemaker with an integrated home monitoring facility was implanted. After her discharge, a rise in the pacing threshold automatically initiated an event message. On the basis of this information, the patient was called in and imminent dislodgement of the ventricular lead was diagnosed by x-ray. The lead was repositioned and was found stable over 1-year follow-up.     

Differences in CMV-Specific T-Cell Levels and Long-Term Susceptibility to CMV Infection after Kidney, Heart and Lung Transplantation

Patients after kidney, heart and lung transplantation differ in their immunosuppressive drug regimens and in susceptibility to infectious complications with cytomegalovirus (CMV). In this study, CMV-specific T-cell responses were characterized in long-term transplant recipients and associated with the frequency of infectious complications. CMV-reactive CD4 T cells from 50 healthy controls, 68 renal, 14 heart and 24 lung transplant recipients were flow cytometrically quantified by the induction of cytokines after specific stimulation. Moreover, the immunosuppressive effect of calcineurin inhibitors on specific T-cell reactivity was quantified in vitro and compared with responses in vivo. Median CMV-specific T-cell frequencies in long-term renal (1.48%; range 0.06-17.26%) and heart transplant recipients (0.90%; 0.13-12.49%) did not differ from controls (1.82%; 0.26-21.00%). In contrast, CMV-specific T-cell levels were significantly lower in lung transplant recipients (0.50%; <0.05-4.98%) and showed a significant correlation with the frequency of infectious episodes (r =-0.57, p = 0.005). The differences within the groups were associated with increasing dosages of immunosuppressive drugs, as exemplified for calcineurin inhibitors that dose dependently reduced specific T-cell reactivity in vitro. In conclusion, monitoring CMV-specific CD4 T cells may serve as a measure for long-term disease susceptibility and may contribute to an improved management of CMV complications after lung transplantation.     

A method for assessing quality of control from glucose profiles.

AIM: As the practice of multiple assessments of glucose concentration throughout the day increases for people with diabetes, there is a need for an assessment of glycaemic control weighted for the clinical risks of both hypoglycaemia and hyperglycaemia. METHODS: We have developed a methodology to report the degree of risk which a glycaemic profile represents. Fifty diabetes professionals assigned risk values to a range of 40 blood glucose concentrations. Their responses were summarised and a generic function of glycaemic risk was derived. This function was applied to patient glucose profiles to generate an integrated risk score termed the Glycaemic Risk Assessment Diabetes Equation (GRADE). The GRADE score was then reported by use of the mean value and the relative percent contribution to the weighted risk score from the hypoglycaemic, euglycaemic, hyperglycaemic range, respectively, e.g. GRADE (hypoglycaemia%, euglycaemia%, hyperglycaemia%). RESULTS: The GRADE scores of indicative glucose profiles were as follows: continuous glucose monitoring profile non-diabetic subjects GRADE = 1.1, Type 1 diabetes continuous glucose monitoring GRADE = 8.09 (20%, 8%, 72%), Type 2 diabetes home blood glucose monitoring GRADE = 9.97 (2%, 7%, 91%). CONCLUSIONS: The GRADE score of a glucose profile summarises the degree of risk associated with a glucose profile. Values < 5 correspond to euglycaemia. The GRADE score is simple to generate from any blood glucose profile and can be used as an adjunct to HbA1c to report the degree of risk associated with glycaemic variability.     

肛门括约肌肌电图监测下双侧L2～S2选择性脊神经后根切断术治疗痉挛性脑瘫

目的为提高手术安全性,在L2～S2选择性脊神经后根切断(SPR)手术时,对肛门括约肌进行肌电图(EMG)监测,并评价其作用。方法在SPR手术监测中,当对S2后根小束进行电刺激时,采用针状电极记录双侧肛门括约肌的反应情况,有明显反应的后根小束予以保留。手术后随访患者踝痉挛改善情况和括约肌功能变化情况。结果所有患者手术后踝痉挛均有明显改善,无大小便功能障碍发生。结论SPR手术包括S2后根时,术中括约肌EMG监测对保证疗效,保护括约肌功能,提高手术安全,具有重要意义。     

孕妇凝血指标的数学模型及指标异常变化警戒值探讨

目的探讨孕妇不同孕期凝血指标变化趋势的数学模型及凝血指标异常变化的警戒值估计,帮助临床医生及预防保健人员及早期发现高危人群,有效预防产科出血和凝血并发症的发生。方法对214例孕妇的孕期凝血指标进行回顾性追索,根据聚类分析的结果,建立方差分析、回归分析及ARIMA时间序列分析模型,比较各检测指标在不同孕期的变化规律。结果所建模型均能够很好的模拟不同孕期凝血指标的变化规律,结果显示:PLT指标值在孕晚期出现明显的下降(P0.05),PT与INR指标值在妊娠中期的下降明显(P0.01),APTT在整个妊娠期均下降(P0.01),FG指标值在妊娠晚期出现上升(P0.01),不同孕期凝血指标的警戒值表达式为:μ±2σ。结论所建模型能够较好的模拟不同孕期凝血指标变化规律,不同孕期凝血指标的正常参考值范围及异常警戒值具有一定的医学应用价值。     

Occupational chronic exposure to metals

Summary Stainless steel welders (n = 103) were examined. To estimate external exposure, personal air sampling was used. Internal exposure was quantified by the determination of nickel levels in erythrocytes, plasma and urine. Men and women (n = 123) were examined for control purposes. In the plasma and erythrocytes of the controls the nickel concentration was below the level of detection (< 1.81 μg/l). The element concentrations in urine were between < 0.1 and 13.3 μg/l. Of the controls 95% showed nickel levels in urine below 2.2 μg/l (reference value). The average concentration of nickel in the air was 93 ± 81 μg/m³. The average concentration of nickel in the plasma samples was 4.9 ± 4.0 μg/l (95th percentile 12.8 μg/L). In erythrocytes nickel could not be detected. The nickel concentrations in the urine of the welders were 18.5 ± 28.5 μg/l on average (95th percentile 52.5 μg/l). Only a weak correlation between the nickel levels of plasma and urine could be detected (C_urine = 2.07 + 8.45 C_plasma; r = 0.294; p < 0.01). Based on our results and on the reported literature a future limit value for the nickel concentration in urine should lay between 30 and 50 μg/l. This value corresponds to an external exposure of 500 μg nickel per cubic metre.     

全国部分城乡家鼠鼠情监测三年结果分析——Ⅰ.鼠种组成及地区分布

对全国部分城乡家鼠鼠情监测三年结果的分析表明:城乡家鼠组成均以三大家鼠(褐家鼠、小家鼠、黄胸鼠)为主,其次为食虫目臭鼩鼱~#和黑线姬鼠。五种主要鼠种在家鼠组成中的数量比基本稳定,但三年中城乡少数鼠种间的顺位有所变化。监测结果亦表明,五种主要鼠种的地区分布是:褐家鼠、小家鼠遍布所有监测的省、市、区,同以往文献中遍布全国的说法一致;黄胸鼠分布于黄河以南;食虫目中的臭鼩鼱分布于华中区以南的广大地区。这在以往文献中均已有记载,但以往文献有关黄胸鼠和臭鼩鼱分布的其他说法,则被证实为不确切的。黑线姬鼠的分布范围已超过以往文献中关于分布于东北、华北及长江流域的说法,但以往文献中关于该鼠种遍及全国的说法是否正确,则有待进一步证实。