Silicon neuron simulation with SPICE: tool for neurobiology and neural networks

The paper deals with computer simulations of ‘silicon neurons’, which are assemblies of CMOS circuits that generate the equivalents of the ionic currents and of the action potentials of real (biological) neurons. The circuit simulation program SPICE is used to simulate the generation of action potentials by a silicon neuron. Moreover, the equivalent circuits of silicon synapses are described and the behaviours of simple two- and three-neuron networks are analysed. Implications for the areas of neurobiology and formal neural networks are briefly considered.     

Safety assessment for octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate (CAS Reg. No. 2082-79-3) from use in food contact applications

Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (CAS Reg. No. 2082-79-3), currently marketed as Irganox 1076 (I-76), is a sterically hindered phenolic antioxidant used in a variety of organic substrates, including those used in the manufacture of food contact articles. In 2012, the US Food and Drug Administration (USFDA), Office of Food Additive Safety (OFAS), initiated a post-market re-evaluation of the food contact applications of I-76. This project aimed to ensure that current dietary exposures from the use of I-76 in food contact articles are accurately captured and the safety assessment considered all relevant and available toxicological information. To accomplish these aims, the USFDA reviewed the available toxicological studies and chemistry information on food contact applications of I-76. Based on this in-depth analysis, a NOAEL of 64 mg/kg-bw/d (female rats) from a chronic rat study and a cumulative estimated dietary intake (CEDI) of 4.5 mg/p/d, was used to calculate a margin of exposure (MOE) of ∼850. We concluded that the previous and current exposure levels provide an adequate margin of safety (MOS) and remain protective of human health for the regulated uses.     

不同部位电刺激治疗带状疱疹神经痛的疗效分析

目的:对治疗带状疱疹神经痛(zoster-related neuralgia,ZRN)的短时程背根神经电刺激与脊髓电刺激两种方法的手术时间、放射暴露剂量、疗效及花费进行比较。方法:本文采用回顾性分析方法,对202例在DSA(digital subtraction angiography)引导下使用短时程电刺激治疗的带状疱疹神经痛病人(其中64例采用背根神经电刺激,138例采用脊髓电刺激),记录手术操作时间及每一例手术的辐射剂量,术后病人的程控次数,术前及术后1、2、3月等各时间段病人的疼痛程度,生活质量以及医疗耗材费等信息,并进行分析比较。结果:在3个月的随访期间,所有病人在两种方法治疗后疼痛视觉模拟评分法(visual analogue scale,VAS)评分和匹兹堡睡眠质量指数(Pittsburgh sleep quality index,PQSI)显著下降,而生活质量(SF-36健康调查简表)评分显著上升(P<0.01),且两种方法之间无统计学差异,然而背根神经电刺激病人的手术时间和术中辐射量明显少于脊髓电刺激组(P<0.05);且术后平均程控次数以及医疗耗材费用也明显少于脊髓电刺激组(P<0.05)。结论:短时程背根神经电刺激和脊髓电刺激都能有效治疗带状疱疹神经痛,但背根神经电刺激具有程控次数少、覆盖好、花费少等优点。     

三痹汤治疗膝骨性关节炎

目的:观察三痹汤治疗膝骨性关节炎(knee osteoarthritis,KOA)的临床疗效。方法:120例KOA患者随机平均分为治疗组和对照组。治疗组给予三痹汤,对照组给予硫酸氨基葡萄糖胶囊。治疗后,比较两组患者临床疗效,临床症状疗效,视觉模拟评分(visual analogue scale,VAS),西安大略和麦克马斯特大学骨关节炎指数(Western Ontario and McMaster university of orthopedic index,WOMAC)评分,健康调查简表(the MOS item short from health survey,SF-36)评分及不良反应。结果:治疗组有效率为86.7%(52/60),对照组为60.0%(36/60),两组有效率比较,差异有统计学意义(P<0.05)。治疗后,两组临床症状评分比较,治疗组无效例数显著少于对照组,差异均有统计学意义(P<0.05)。治疗后,两组患者VAS、WOMAC评分均低于治疗前,治疗组治疗后低于同期对照组,差异均有统计学意义(P<0.05)。治疗后,两组患者SF-36评分均高于治疗前,治疗组治疗后高于同期对照组,差异均有统计学意义(P<0.05)。治疗组不良反应率为5.00%,对照组为16.67%,两组不良反应率比较,差异有统计学意义(P<0.05)。结论:三痹汤治疗KOA临床疗效显著,可显著改善患者临床症状,降低VAS、WOMAC评分,提高SF-36评分,且无明显不良反应。     

成人阻塞性睡眠呼吸暂停低通气综合征患者的人格特征分析

目的　调查成人阻塞性睡眠呼吸暂停低通气综合征（OSAHS）患者的人格特征及生活质量,了解该患病群体的心理健康情况。方法　采用明尼苏达多项人格测量表（Minnesota multiphasic personality inventory,MMPI）和简明健康状况调查表（the MOS item short from health survey,SF-36）分别对98例成人OSAHS患者及100例单纯鼾症志愿者进行问卷调查,评价OSAHS患者的人格特征及生活质量情况并进行对照性研究。结果　在MMPI调查中,OSAHS患者在抑郁、疑病、精神衰弱、情绪不稳定、精神分裂临床量表T分高于单纯鼾症组,差异具有统计学意义（P＜0.05）,其中OSAHS组中女性患者的抑郁、疑病、精神衰弱、情绪不稳定、精神分裂、社会内向临床量表T分高于男性患者,差异具有统计学意义（P <0.05）。在SF-36调查中,OSAHS患者在生理职能、一般健康状况、躯体疼痛、精力、社会功能、情感功能、精神健康7个维度的平均评分低于单纯鼾症组,差异具有统计学意义（P＜0.05）。结论  OSAHS患者有较多的心理健康问题,表现更多的易疲劳、注意缺陷,生活质量更低,OSAHS病情越重,心理健康问题越大,女性患者尤重。     

Placental pathology and neurological morbidity in preterm infants during the first two weeks after birth

Background

The placenta plays a crucial role during pregnancy and dysfunction causes long-term neurological problems. Identifying placenta-related risks for neurological problems shortly after birth may provide clues for early interventions aiming to improve neurological outcome.

Objective

To determine the association between placental pathology and neurological morbidity in preterm infants during the first two weeks after birth.

Study design

Placentas of 52 singleton, preterm infants (GA: 25–31 weeks, BW: 560–2250 grammes) were examined for histopathology. The infants' neurological condition shortly after birth was determined by assessing the quality of their general movements (GMs): normal, abnormal, or hypokinetic, on days 5, 8, and 15. A motor optimality score (MOS) was also assigned.

Results

Examination of the placentas revealed maternal vascular underperfusion (n = 29), ascending intrauterine infection (AIUI) (n = 19), villitis of unknown aetiology (n = 6), chronic deciduitis (n = 11), foetal thrombotic vasculopathy (FTV) (n = 9), and elevated nucleated red blood cells (NRBCs) as a marker for foetal hypoxia (n = 7). None of the placental lesions were significantly associated with the quality of GMs or MOS.

Conclusions

This study indicated that placental lesions were not associated with infants' neurological condition as measured by the quality of their general movements during the first two weeks after birth.     

Identifying cut-off scores with neural networks for interpretation of the incontinence impact questionnaire

We propose to determine cut-off scores for the Incontinence Impact Questionnaire (IIQ) based on the neural network (NN) approach. These cut-off scores should discriminate between patients having poor, moderate, or good quality of life (QoL) secondary to their incontinence problems. Data from two prospectively completed QoL questionnaires, the IIQ (n = 237) and the MOS 36-Item Short-Form Health Survey (SF-36) (n = 237), were analyzed using NN and conventional statistical tools. Kohonen networks identified three distinct clusters of IIQ scores. The three clusters represent the full spectrum of possible scores on the IIQ. We interpreted these clusters as reflecting good, moderate, and poor QoL. We estimated that a score of less than 50 on the IIQ would be representative of good QoL, between 50 and 70 would be moderate QoL, and greater than 70 would be indicative of poor QoL. Validation with the SF-36 data confirmed these categories. The present study demonstrated that the NN approach is opening new areas in the interpretation and clinical usefulness of QoL questionnaires. NN allowed the identification of three levels of QoL and should be useful in clinical decision making.     

Psychometric properties of the MOS (Medical Outcomes Study) Sleep Scale in patients with neuropathic pain.

OBJECTIVE: This study assessed the psychometric properties of the MOS Sleep Scale in neuropathic pain (NeP). METHODS: Psychometric properties were tested in patients with neuropathic pain enrolled in a prospective study exploring the effectiveness of gabapentin for 3 months. Participants also completed scales for pain intensity, anxiety, depression, disability, and health-related quality of life. Feasibility, reliability, validity and sensitivity to change were measured in this study. RESULTS: Six-hundred-three patients [58.4+/-14.4 years (65.1% female), mean+/-SD] with pain for 1.2+/-3.3 years were included. The MOS Sleep Scale was acceptable (items with missing data <10% and floor and ceiling effects <50% per item and <15% per domain) and reliable (Cronbach's alpha between 0.64 and 0.87, and test-retest intraclass correlation coefficients between 0.79 and 0.91, p<0.001 for all cases). After adjusting for confounders, the MOS Sleep Scale was able to distinguish between sex, present pain intensity, level of disability and presence of anxiety or depression. Correlations with other scales were moderate; rho-coefficients between -0.21 and 0.57 (p<0.01, all cases). The scale was sensitive to change after treatment with gabapentin; after adjusting, responders (50% reduction in baseline pain) showed a decrease in sleep problems index of -25.6+/-14.3 points vs. -12.1+14.5 points in nonresponders (F=80.5, df=1/398, p<0.0001). Score reduction in summary index and subscales correlated significantly with pain intensity reduction (Pearson r-coefficients between 0.428 and 0.116, p<0.01, all cases). CONCLUSIONS: The MOS Sleep Scale showed good psychometric properties and was sensitive to changes in patients with NeP of broad aetiology.     

Predictors of general quality of life and the mediating role of health related quality of life in patients with schizophrenia

Introduction  The concept ‘quality of life’ (QoL) has become increasingly important as an outcome measure in the evaluation of services and in clinical trials of people with schizophrenia. This study examines the mediating role of health related quality of life (HRQoL) in the prediction of general quality of life (GQoL). Method  QoL and other patient- and illness characteristics (psychopathology, overall functioning, illness history, self-esteem and social integration) were measured in a group of 143 outpatients with schizophrenia. GQoL was measured by the Lancashire Quality of Life Profile and HRQoL was measured by the MOS SF-36. To test the temporal stability of our findings, assessments were performed twice with an 18-month interval. Results  We found that patient’s GQoL is predicted mainly by anxiety and depression and self-esteem and to a lesser extent by global functioning and social integration. At both time intervals HRQoL appeared to be a significant mediator of the relationship between anxiety and depression and self esteem versus patient’s GQoL. Conclusions  The results of this study are important for mental health professionals, as these provide more insight in the mechanisms by which they could improve the GQoL of their patients with schizophrenia. The results confirm that diagnosis and treatment of anxiety and depression in outpatients with schizophrenia deserves careful attention of clinicians. Also strategies and specific interventions to improve self-esteem of patients with schizophrenia are very important to maximise patient’s QoL.     

Safety evaluation of an IPP tripeptide-containing milk protein hydrolysate

Tensguard™ is a milk protein hydrolysate containing the lactotripeptide IPP. It is derived from cow’s milk, which is present in the human diet and has a safe history of consumption. The final Tensguard™ product, a supplement or a functional food ingredient, is intended for use by people who want to follow a healthy diet and lifestyle in order to manage their blood pressure. The safety-in-use of commercial lactotripeptide-containing products has been confirmed in several in vitro and in vivo toxicity studies and in studies with humans. To support the safety, Tensguard™ was examined in three in vitro genotoxicity tests (bacterial reverse mutation test, mammalian cell gene mutation test and mammalian chromosomal aberration test) and in a 90-day repeated-dose oral toxicity study in rats. The genotoxicity tests confirm that Tensguard™ is not mutagenic or clastogenic. The NOAEL from the 90-day study was at the highest dose tested, i.e. 4% in the diet. The NOAEL is equivalent to an overall mean intake of 2 g Tensguard™/kg body weight/day and corresponds to 40 mg IPP/kg body weight/day. This is 141-fold higher than the maximal anticipated intake. In conclusion, Tensguard™ is safe under the conditions of intended use.