宫颈病变程度与人类乳头瘤病毒(16、18型)负荷的关系

目的探讨宫颈病变程度与人类乳头状瘤病毒(HPV)16、18型负荷的关系。方法采用实时荧光定量聚合酶链反应(FQ-PCR)方法,检测宫颈不同病变活检组织及石蜡包埋标本中HPV16、18型感染状况。结果正常宫颈上皮感染HPV16、18型阳性率为3%,CINⅠ、Ⅱ、Ⅲ级和宫颈癌感染HPV16、18阳性率分别为45.7%,69.5%,72.2%和74.6%。正常宫颈与CIN,宫颈癌HPV16、18阳性率差异有极显著性(P<0.0001)。宫颈糜烂(Ⅰ°、Ⅱ°、Ⅲ°),CIN(Ⅰ、Ⅱ、Ⅲ级)及鳞癌HPV16、18阳性标本平均拷贝数分别为:3.58×103、1.80×105、1.19×107,随着病变程度加重而逐渐增加,差异有极显著性(P<0.0001)。结论宫颈病变程度与HPV16、18型负荷呈正相关。对宫颈病变组织标本行HPV16、18型检测,对判断宫颈病变发展趋势,积极处理癌前病变,阻断病程、预防宫颈癌的发生将起到重要作用。     

Task-dependent mixtures of coordinate systems in visuomotor transformations

In two experiments the involvement of relative and fixed coordinate systems in visuomotor transformations was examined. The experimental task required the successive performance of two movements in each trial, which had to “correspond” to different visual stimuli. One kind of visual display indicated target positions by way of different horizontal positions of a vertical line on a monitor (position mode), while the other indicated movement amplitudes by way of different lengths of a horizontal line (amplitude mode). Formal analysis of variances and covariances of successive individual movements led to the conclusion that in the position mode visuomotor transformations were based on a mixture of relative and fixed coordinate systems, while in the amplitude mode only a relative coordinate system was involved. Thus, visuomotor transformations can be characterized as mixtures of different coordinate systems, and their respective weights in the mixtures are task-dependent. Received: 18 March 1997 / Accepted: 25 September 1997     

p21 ras protein expression in benign and malignant

The ras oncogenes encode for GTP binding and GTPase active proteins of relative molecular mass 21 000 (p21^ras) which are involved in the transduction of stimuli for cell proliferation. There have been conflicting reports about the detection and significance of expression of p21^ras protein in human breast disease as determined by immunohistochemistry. The antibody Y13-259, which detects a single protein of M_r 21 000, has been applied immunohistochemically to frozen sections of normal, benign proliferative breast, fibroadenomas, and carcinomas. Uniform staining of normal breast epithelium and myoepithelium was found, with occasional stronger staining in areas of epithelial hyperplasia in benign breast disease. Contrary to previous reports, decreased expression, usually heterogeneous, was found in half of the carcinomas examined. Thirty per cent of the carcinomas exhibited heterogeneous staining stronger than that of normal breast, interpreted as increased expression of p21^ras protein. This did not relate to tumour grade or node status but showed a significant correlation with proliferation rate as determined by the monoclonal antibody Ki-67. This study confirms previous reports that p21^ras protein expression is a feature of normal cells, and has identified increased expression in 30 per cent of tumours associated with higher proliferation rates, which is a lower incidence than previously claimed when a different antibody was employed.     

Directional specificity of postural muscles in feed-forward postural reactions during fast voluntary arm movements

Healthy subjects performed bilateral fast shoulder movements in different directions while standing on a force platform. Anticipatory postural adjustments were seen as changes in the electrical activity of postural muscles as well as displacements of the center of pressure and center of gravity. Postural muscle pairs of agonist-antagonist commonly demonstrated triphasic patterns starting prior to the first electromyographic (EMG) burst in the prime-mover muscle. Proximal postural muscles demonstrated the largest anticipatory increase in the background activity during movements in one of the two opposite directions (forward or backwards). These changes progressively decreased when movements deviated from the preferred direction and frequently disappeared during movements in the opposite direction. The patterns in distal muscles varied across subjects and could demonstrate larger anticipatory changes during movements forward and backwards as compared to movements in intermediate directions. Bilateral addition of inertial loads to the wrists did not change the general anticipatory patterns, while making some of their features more pronounced. Anticipatory postural adjustments were followed by later changes in the activity of postural muscles, also reflected in the mechanical variables. Changes in leg joint angles revealed a hip-ankle strategy during shoulder flexions and an ankle strategy during shoulder extensions. The study demonstrates different behaviors of proximal and distal muscles during anticipatory postural adjustments in preparation for fast arm movements. We suggest that the proximal muscles produce a general pattern of postural adjustments, while distal muscles take care of fine adjustments that are more likely to vary across subjects.     

The influence of visual illusions on grasp position

 Visual size illusions have been shown to affect perceived object size but not the aperture of the hand when reaching to those same objects. Thus, vision for perception is said to be dissociated from vision for action. The present study examines the effect of visual-position and visual-shape illusions on both the visually perceived center of an object and the position of a grasp on that object when a balanced lift is required. The results for both experiments show that although the illusions influence both the perceived and the grasped estimates of the center position, the grasp position is more veridical. This partial dissociation is discussed in terms of its implications for streams of visual processing. Received: 17 November 1997 / Accepted: 11 September 1998     

Supraspinal effects on the fractal correlation in human H-reflex

In our previous study, -type power spectrum with the spectral exponent significantly greater than zero was found in the variability of soleus H-reflex amplitudes. This result indicated that the H-reflex variability was time-correlated owing to fractal characteristics. Furthermore, it was also suggested that the fractal characteristics were generated at the spinal level. The purpose of the present study was to investigate whether the fractal nature of the H-reflex variability was influenced by the loss of supraspinal input. Six healthy normal subjects and seven patients with spinal cord injury participated in this study. Soleus H-reflexes were evoked every l s from both legs simultaneously (stimulation intensity: motor threshold) and 1050 successive amplitudes of the H-reflex were recorded. The H-reflex sequence evoked from each leg was analyzed by coarse graining spectral analysis to calculate the spectral exponent . The value of was used to evaluate the level of time-correlation (fractal correlation). Cross-spectral analysis was used to evaluate the degree of synchronization between the H-reflex sequences evoked from both legs. The values for normal subjects (0.84±0.33, left leg; 0.88±0.34, right leg) were significantly greater (P<0.001) than those for patients (0.31±0.18, left leg; 0.32±0.14, right leg), suggesting that the H-reflex sequences for normal subjects were more time-correlated than for patients. In the frequency range less than 0.2 Hz, the coherence of both legs was high (0.41±0.14) for normal subjects as compared to 0.20±0.12 for patients (P<0.005). In this frequency range, the phase was almost 0 rad for normal subjects, indicating that the H-reflex variabilities of both legs were synchronized. These results suggested that (1) the strong fractal correlation observed in the H-reflex sequences for normal subjects was associated with supraspinal input, and (2) such supraspinal input had equal influence on the reflex arcs of the soleus of both legs.     

Dependence of adaptation of the human vertical angular vestibulo-ocular reflex on gravity

We determined the spatial dependence of adaptive gain changes of the vertical angular vestibulo-ocular reflex (aVOR) on gravity in five human subjects. The gain was decreased for 1 h by sinusoidal oscillation in pitch about a spatial vertical axis in a subject-stationary surround with the head oriented left-side down. Gains were tested by sinusoidal oscillation about a spatial vertical axis while subjects were tilted in 15° increments from left- to right-side down positions through the upright. Changes in gain of the vertical component of the induced eye movements were expressed as a percentage of the preadapted values for the final analysis. Vertical aVOR gain changes were maximal in the position in which the gain had been adapted and declined progressively as subjects were moved from this position. Gain changes were plotted as a function of head orientation and fit with a sine function. The bias level of the fitted sines, i.e., the gravity-independent gain change, was –29±10% (SD). The gains varied around this bias as a function of head position by ±18±6%, which were the gravity-dependent gain changes. The gravity-dependent gain changes induced by only 1 h of adaptation persisted, gradually declining over several days. We conclude that there is a component of the vertical aVOR gain change in humans that is dependent on the head orientation in which the gain was adapted, and that this dependence can persist for substantial periods.     

High-efficiency gene transfer to primary T lymphocytes by recombinant adenovirus vectors

Recombinant, replication-deficient adenoviruses are efficient vectors for gene transfer to a wide range of cell types, with the exception of T lymphocytes. Here, we show that primary T lymphocytes from peripheral blood, cord blood, and the Jurkat T cell line are efficiently transduced by recombinant adenovirus. Nearly 100% infection efficiency of primary T cells is obtained with high multiplicity of infection (MOI) (5000) of recombinant adenovirus coding for lacZ. Similar infection efficiency by adenovirus-mediated gene transfer was obtained at lower MOI (3000) by activating primary T cells with PHA and PMA. Addition of cationic liposomes together with RAdlacZ markedly enhanced the infection efficiency at lower MOI (1000) resulting in over 90% infection efficiency. Primary T cells express low levels of coxsackievirus and adenovirus receptor (CAR), a cell surface receptor for adenovirus fiber attachment, as well as _vβ₃ and _vβ₅ integrins, cellular receptors for adenovirus internalization. This suggests that adenovirus entry to T cells at high MOI is mediated by other mechanisms. In conclusion, these results demonstrate that genes can be efficiently transferred to primary lymphocytes by adenovirus vectors at high MOI or in combination with cationic liposomes.