基于实时三维超声图像的二尖瓣环重建及运动分析

二尖瓣环的非平面特性对二尖瓣返流的超声诊断和二尖瓣环成形术的合理设计具有重要意义.基于心脏的实时三维超声图像,我们研究了一种对二尖瓣环三维重建及运动分析的方法.首先通过人机交互方式提取出二尖瓣环的特征点,并根据位置关系对特征点排序,然后利用非均匀有理B样条曲线建立二尖瓣环三维形态模型,并编程实现二尖瓣环的动态显示和运动分析.通过对20组病例分析,初步证明此方法所建模型较准确反映患者的二尖瓣环的运动,能满足二尖瓣环三维可视化和分析研究的需要.     

Evolution of semen quality in North-eastern Spain: a study in 22,759 infertile men over a 36 year period

A retrospective study was conducted in a large population to determine whether sperm quality has changed in Northeastern Spain between 1960 and 1996. From a total initial population of 22,759 men, two separate groups were studied: men with spermatozoa (n = 20,411) and those with azoospermia (n = 1364). After adjustment for age and sexual abstinence, multiple linear regression analyses were used to assess changes in semen parameters over time. A 0.2% decline was observed in semen volume in the spermatozoa group (P < 0.001). No significant increase (0.04%) in sperm count (x 10(6)/ml) was observed in the spermatozoa group. There was a 0.4% increase in motile spermatozoa in the spermatozoa group (P < 0.001). There was a statistically significant decline in normal spermatozoa (3.6%) in the spermatozoa group (P < 0.001). Of the total population, 1364 men had azoospermia (6.0%). The changes observed in the semen parameters analysed in this large population showed no evidence of a deteriorating sperm quality, although a statistically significant decline was observed in the percentage of normal spermatozoa.     

52 例病毒性肝炎患者肝组织中丙型肝炎病毒 RNA 和 HCAg-NS3 的测定

应用地高辛标记探针原位杂交法和单克隆抗ＨＣＶ－ＮＳ３－ＨＲＰ建立直接酶标免疫组化法分别测定５２例肝炎患者肝组织ＨＣＶＲＮＡ和ＨＣＡｇ－ＮＳ３。结果抗ＨＣＶ阳性组ＨＣＶＲＮＡ检出率５７．１％（１６／２８），ＨＣＡｇ－ＮＳ３检出率５３．６％（１５／２８）；抗ＨＣＶ阴性组其两项检出率均为１２．５％（３／２４）。肝组织中ＨＣＶＲＮＡ阳性物呈蓝紫色细小颗粒存在于肝细胞核或胞浆内，其在肝小叶中的分布可分为３型，即弥漫型、局灶型、散在型。肝组织中ＨＣＡｇ－ＮＳ３阳性物呈棕黄色细小颗粒分布于肝细胞核或胞浆内，以单个或数个阳性细胞散布于肝小叶中。２３例ＨＣＶＲＮＡ或／和ＨＣＡｇ－ＮＳ３阳性病例以肝炎后肝硬化（ＬＣ）病例占多数（１４／２３），其次为慢性重型肝炎（ＣＳＨ）和中度慢性肝炎（ＣＡＨ）。此两种检测方法具有较高符合率（９０．４％，４７／５２），表明病毒核酸及其表达产物均存在于肝细胞内，与ＨＣＶ感染密切相关。这为ＨＣＶ感染诊断提供了直接依据，有利于研究ＨＣＶ感染中病毒复制、慢性化进程、抗病毒治疗监测及重叠感染时病毒相互关系。     

Bipolar (neural and myoblastic) phenotype in cell lines derived from human germ cell tumours of testis

Non-seminomatous germ cell tumours of the testis (NSGCT) form a heterogeneous group of neoplasms. Cell lines derived from NSGCT may provide useful data concerning the biology of neoplasic precursor germ cells, differentiation of tumour stem cells and the relationship between various tissue components of these tumours. Four NSGCT were studied, two mixed tumours composed of teratocarcinoma, yolk sac and trophoblastic elements, and two malignant teratomas with a massive neuroectodermal component, equivalent to primary neuroectodermal tumours (PNET) of the testis. The explanted tumours gave rise to various cell populations, including epitheloid cells, flattened large cells, spindle cells and tear drop cells of neuroblastic type. Ultrastructurally, cultured cells expressed various degrees of neural and muscular differentiation: neurosecretory granules, intermediate filaments of glial nature, and filaments resembling Z-bands. Cultured cells showed the expression of several neural and muscular markers, including neurofilaments, cytokeratin, actin, desmin, neuron-specific enolase, glial fibrillary acidic protein and HNK-1. In addition, three cases expressed HBA-71 antigen and two expressed MyoDI protein. All cases were aneuploid, and an isochromosome 12p, i(12p), was detected in three cases. Myoblastic and neural cells are the predominant tumour cells that grow in vitro, independent of the nature and composition of the primary germ cell tumour. A histogenetic relationship between germ cell tumours and small round cell tumours of childhood is suggested.     

Cystic fibrosis mutations and immotile cilia syndrome

The immotile cilia syndrome (ICS) presents with autosomal recessive inheritance and is a chronic respiratory disease supposed to be caused by different genetic determinants. The hypothesis that cystic fibrosis (CF) heterozygotes may have a predisposition to develop bronchial or respiratory diseases other than CF prompted us to look for CF mutations in patients with ICS. Five patients, as well as the parents and two healthy brothers of one patient were tested for 12 CF mutations, for the polymorphic GATT repeat in intron 6a and for the CF gene flanking markers XV-2c, KM19, MP6d-9, J3.11. None of the 12 mutations at the CF locus have been detected in the ICS patients and no linkage was found between ICS and the polymorphic markers. Thus, based on our data, ICS and CF seem to be two different clinical entities.     

Capillaries in aging rat olfactory bulb: A quantitative light and electron microscopic analysis

Olfactory bulbs from Charles River (Crl) rats from 3 to 36 months have been examined with light and electron microscopy. Total capillary length, surface, and volume, as well as number of endothelial cells, increases during the twofold increase in olfactory bulb volume from 3 to 18 months, but the relative density of these parameters shows no change during this time; from 18 to 36 months when neuronal cell body and dendrites are decreasing markedly in size, the relative density of capillaries shows only a modest decrease. Capillary lumen size and capillary wall thickness remain the same throughout life, but basal lamina thickness doubles from 3 to 24 months and then remains constant from 24 to 36 months. The incidence of several unusual ultrastructural features of the outer capillary basal lamina has been shown to increase with age.     

On Quantifying Surprise: The Variation of Event-Related Potentials With Subjective Probability

Two factors are known to determine the waveform of event-related potentials (ERP) elicited by task-relevant stimuli: the a priori probability of the stimuli and the sequence of immediately preceding stimuli. The relative contribution of these factors to the ERP waveform was assessed at nine levels of a priori probability (from .10 to .90). Random sequences of high (1500 Hz) and low (1000 Hz) tones were presented to 10 male subjects at each level of probability, both when the events were task-relevant and when the subjects were performing an alternate task to which the tones were irrelevant. The EEG was recorded from five midline electrode sites referred to linked mastoids. The amplitude of the P300 and Slow Wave components was inversely proportional to the a priori probability of task-relevant events. At every level of a priori probability, the magnitude of the P300 complex (N200-P300-Slow Wave) was diminished when the eliciting tone repeated the preceding tone, and was enhanced when it was preceded by the other tone. Thus, a priori probability and sequential structure appear to be independent determinants of the P300 complex.     

基于多分辨率分析的心室晚电位神经网络检测

采用多分辨率分析和人工神经网络相结合的方法实现对心室晚电位的检测。首先利用多分辨率分解技术提取高分辨率心电信号不同频带的能量构成一组特征值 ,再利用这些特征值训练BP神经网络 ,并完成对心室晚电位的识别。经过对 2 8例 3导高分辨率心电图实验数据的处理 ,取得了较高的识别准确率     

The structuring of an allergy index based on IgE-mediated skin sensitivity to common environmental allergens

We computed skin-test sensitivity levels in 485 adults puncture-tested with eight standardized, high-quality inhalant allergens tested at single concentrations. In order to quantitate the "average" IgE-mediated skin sensitivity of each subject, we used both nonparametric and parametric statistical methods to generate two "allergy indices" (Allergy Index I and Allergy Index II) based on sensitivity end-point data from the subpopulations of individuals positive to six of the eight allergens. For the 192 skin test-positive subjects, Allergy Index I and Allergy Index II were significantly correlated with each other (rs = 0.98, p less than 0.001) and with the number of positive skin-test reactions (rs congruent to 0.9, p less than 0.001) as well as with log[total serum IgE] (r congruent to 0.4, p less than 0.01). In 102 ragweed-positive subjects, log[specific IgE to ragweed] was significantly correlated with ragweed-specific "ragweed indices I and II" (r congruent to 0.6, p less than 0.01). Furthermore, the average daily symptom scores reported by 14 ragweed-positive subjects during the ragweed pollination season were significantly correlated with ragweed indices I and II (p less than 0.05). We propose the use of Allergy Index II in epidemiologic and genetic studies of allergic phenotypes as well as in clinical decisions for diagnosis and immunotherapeutic intervention.