Neonate blood IgE levels on filter paper as indicators of atopic disease

Measurements of IgE levels in the blood of neonates were investigated using filter paper for blood collection in mass screening of congenital metabolic disorders. Time-resolved fluoroimmunometric assay system for the measurement of filter paper blood IgE levels was also studied. In an analysis of the present results, IgE values of at least 0.015U/ml, the measurement limit, were considered as high. High IgE levels in filter paper blood were seen in 28 (7.2%) of the 389 cases. When the relation with serum IgE levels at 18 months of age was investigated in 134 of 389 subjects, high serum IgE levels were also found in about 86.7% of the subjects with high IgE levels in filter paper blood. In addition, when the relation between family history of atopic disease and presence of atopic disease in the first 18 months of age was investigated in 203 of the 389 subjects, about 90% of the subjects with a family history of atopic disease and high IgE levels in filter paper blood developed atopic disease. Since filter paper blood is routinely collected in Japan, IgE levels in this blood should be widely checked for the prediction of onset of atopic disease in infants.     

A simple organ culture method for differentiation of melanocytes in mouse embryonic skin using “origami” membrane filter

Summary A simple organ culture method for culturing embryonic skin was developed. A piece of skin with a part of the neural tube from mouse embryo (11 to 12 d) was placed on a 25 mm d membrane filter. The filter was folded to wrap the explant and inserted into glass tubing. The explant and filter in the glass tubing were placed in a rotating tissue culture tube containing 5 ml culture medium (Ham's F12 supplemented with 15 to 20% fetal bovine serum) and filled with a mixture of 95% air:5% CO₂. In explants cultured for 6 d fully differentiated melanocytes were observed in the epidermis.     

Fluid Flow through Filtering Appendages of Insects

Many organisms use structures composed of arrays of cylindersto capture particulate food or molecules form the water or airaround them. The performance of such filters depends on thevelocity of fluid movement through them; hence, mathematicalmodels of flow through fibrous structures can provide insightsabout the functional morphology of biological filters. In thispaper, the authors address the case of feather-like biologicalfilters of finite width and assess several possible models forfluid motion through them by comparing model predictions withobservational data. Two examples of insect appendages are considered:the cephalic fans of black fly aquatic larvae that capture particulatefood and the antennae of adult male moths that catch sex-attractantmolecules released by female moths. The results suggest thatflow through such structures can be much slower than ambientcurrents, that the finest hairs in the structure are the morphologicalfeatures with the greatest effect on leakiness, and that thevelocity of movement (or of ambient flow), as well as the morphologyof such filters, can be critical in determining their performance.     

神经移位治疗火器性肌皮神经和腋神经损伤

在观察和测量100个上肢解剖标本的基础上,我们设计了带血管的胸背神经和下肩胛下神经移位,一期修复一例火器性肌皮神经和腋神经损伤.术后8个月复查功能恢复甚为满意.     

Engulfment of mast cell secretory granules on skin inflammation boosts dendritic cell migration and priming efficiency

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A Parametric Approach to Measuring Cerebral Blood Flow Autoregulation from Spontaneous Variations in Blood Pressure

Autoregulation maintains cerebral blood flow (CBF) almost constant in the face of changes in arterial blood pressure (ABP). Tests for impairment of this process using only spontaneous fluctuations in ABP, without provoking large variations, are of great clinical interest, and a range of different approaches have previously been applied. Extending earlier work based on linear filters, we propose a simple parametric method using a first order finite impulse response filter. We evaluate the method on ABP and CBF velocity [(CBFV), from trancranial Doppler ultrasound] signals collected in 60 patients with stenosis or occlusion of the carotid arteries. Data were collected during the inspiration of ambient air, a 5% CO2/air mixture, and finally the return to ambient air. Equivalent data were collected in 15 normal subjects. The filters estimated from the data segments with constant inspiratory pCO2 showed the expected high-pass characteristic, which was reduced during hypercapnia and also in patients. Highly significant correlation between the filter parameters and cerebrovascular reactivity (percent increase in CBFV per unit change in end-tidal pCO2) gives further evidence that the filters reflect autoregulation. The method allows simple parametrization of the dynamic autoregulatory responses in CBFV, and the analysis of short (1 min) data segments. © 2001 Biomedical Engineering Society. PAC01: 8719Uv, 4762+q, 4380Qf     

内耳门周结构对内镜下脑桥小脑三角区手术的影响

目的：研究内耳门周结构对颞骨径路内镜下处理脑桥小脑三角区病变手术的影响，为临床开展相应手术提供参考。方法：在20例40侧成人尸头上模拟颞骨径路内窥镜手术，观察小脑下前动脉及内耳门后唇的变异，了解其对内窥镜导入及其手术的影响。结果：内耳门后唇隆起超过面神经脑桥小脑角段1／3以上者占27．5％(11侧)。小脑下前动脉在Ⅶ、Ⅷ脑神经外侧成袢者占22．5％(9侧)。内耳门后唇隆起合并小脑下前动脉袢在Ⅶ、Ⅷ脑神经之外侧者占7．5％(3侧)。结论：当内耳门后唇隆起超过面神经脑桥小脑角段1／3或小脑下前动脉弓在Ⅶ、Ⅷ脑神经之前时将对内窥镜导入有阻碍，当两种情况合并存在时要将内窥镜导入脑桥小脑三角区相当困难，不宜采用此种手术方式。     

Adaptive spatial filtering of multichannel surface electromyogram signals

Spatial filtering of surface electromyography (EMG) signal can be used to enhance single motor unit action potentials (MUAPs). Traditional spatial filters for surface EMG do not take into consideration that some electrodes could have poor skin contact. In contrast to the traditional a priori defined filters, this study introduces an adaptive spatial filtering method that adapts to the signal characteristics. The adaptive filter, the maximum kurtosis filter (MKF), was obtained by using the linear combination of surrounding channels that maximises kurtosis. The MKF and conventional filters were applied to simulated EMG signals and to real EMG signals recorded with an electrode grid to evaluate their performance in detecting single motor units. The MKF was compared with conventional spatial filtering methods. Simulated signals, with different levels of spatially correlated noise, were used for comparison. The influence of one electrode with poor skin contact was also investigated. The MKF was found to be considerably better at enhancing a single MUAP than conventional methods for all levels of spatial correlation of the noise. For a spatial correlation of 0.97 of the noise, the improvement in the signal-to-noise ratio, where a MUAP could be detected, was at least 6 dB. With a simulated poor skin contact for one electrode, the improvement over the other methods was at least 19 dB.     

Analysis of dynamic cerebral autoregulation using an ARX model based on arterial blood pressure and middle cerebral artery velocity simulation

The study aimed to model the cerebrovascular system, using a linear ARX model based on data simulated by a comprehensive physiological model, and to assess the range of applicability of linear parametric models. Arterial blood pressure (ABP) and middle cerebral arterial blood flow velocity (MCAV) were measured from 11 subjects non-invasively, following step changes in ABP, using the thigh cuff technique. By optimising parameters associated with autoregulation, using a non-linear optimisation technique, the physiological model showed a good performance (r=0.83±0.14) in fitting MCAV. An additional five sets of measured ABP of length 236±154 s were acquired from a subject at rest. These were normalised and rescaled to coefficients of variation (CV=SD/mean) of 2% and 10% for model comparisons. Randomly generated Gaussian noise with standard deviation (SD) from 1% to 5% was added to both ABP and physiologically simulated MCAV (SMCAV), with ‘normal’ and ‘impaired’ cerebral autoregulation, to simulate the real measurement conditions. ABP and SMCAV were fitted by ARX modelling, and cerebral autoregulation was quantified by a 5 s recovery percentage R5% of the step responses of the ARX models. The study suggests that cerebral autoregulation can be assessed by computing the R5% of the step response of an ARX model of appropriate order, even when measurement noise is considerable.     

New algorithmic-based digital filter processing system for real-time continuous blood pressure measurement and analysis in conscious rats

A new algorithmic-based digital filter processing system for real-time continuous blood pressure (BP) measurement and analysis in freely-moving conscious rats has been developed. Real-time recognition of BP waveforms, real-time noise rejection and determination of representative waveform indexes (WIs) at indicated time points using digital filters and Smirnov's rejection test were realized with this system. Digital filters were applied for two different purposes: waveform segmentation and smoothing the calculations of representative WIs. Smirnov's rejection test was used for real-time noise rejection and yielded an accurate rejection rate of 99.99%. The result was that the digital filter processing and Smirnov's rejection test realized accurate real-time BP measurement and analysis in freely-moving conscious rats using a personal computer.