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11.
Q. Peng J. Moan Jahn M. Nesland Jan F. Evensen M. Kongshaug C. Rimington 《Lasers in medical science》1990,5(4):399-409
Observations on time-dependent localization of tetra(3-hydroxyphenyl)porphin (3-THPP) in human malignant melanoma transplanted to athymic nude mice from 1 to 120 h after intraperitoneal (i.p.) 10 mg kg–1 b.w. administration were made by means of fluorescence microscopy. Fluorescence was found on the membrane of the melanoma cells and in the cytoplasm with a peak fluorescence intensity at 24 h post-injection of 3-THPP. The growth of the tumour cells was obviously inhibited at an early stage after PCT. Morphological changes of the tumour at various intervals after treatment by PCT with 3-THPP were also observed. Diffuse degeneration of the tumour cells with swelling of mitochondria and endoplasmic reticulum, heterochromatin aggregation and margination, etc., and subsequently diffuse necrosis with little or no the background of tumorous vascular response were found at an early stage after PCT. On the other hand, it was also observed that the necrosis of the melanoma areas was caused as a consequence of tumorous vascular injury at a later stage after PCT. Thus, two tumoricidal processes caused by PCT with 3-THPP were seen: a direct phototoxic action on tumour cells at an early stage after PCT and an indirect effect secondary to tumorous vascular injury at a later period after PCT. 相似文献
12.
Jean-Marie Danion Marie-Agathe Zimmermann Dominique Willard-Schroeder Danielle Grangé Marie Welsch Jean-Louis Imbs Léonard Singer 《Psychopharmacology》1990,102(3):422-424
The effects of scopolamine, an anticholinergic drug, of trimipramine, a tricyclic antidepressant with both anticholinergic and sedative properties, of diazepam and a placebo, on explicit memory and repetition priming were assessed using a free-recall task and a word-stem completion task. Forty-eight healthy volunteers took part in this double-blind study. Diazepam provoked a dissociation between free recall, which was profoundly impaired, and word completion, which was spared. No significant changes in memory performances were observed in the scopolamine group; however, a significant correlation between explicit and implicit memory performances was observed in this group. At the low dose used, the effects of trimipramine on memory were mild. The results suggest that the cholinergic system is involved in the priming effect. 相似文献
13.
Tape stripping of human stratum corneum yields cell layers that originate from various depths because of furrows in the skin 总被引:2,自引:0,他引:2
R. G. van der Molen F. Spies J. M. van ‘t Noordende E. Boelsma A. M. Mommaas H. K. Koerten 《Archives of dermatological research》1997,289(9):514-518
Received: 21 November 1996 相似文献
14.
Z. Lackovi M. Jakup
evi A. Bunarevi I. Damjanov M. Relja I. Kostovi 《Brain research》1988,443(1-2):199-203
The content of serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA) and norepinephrine (NE) was analysed in 71 human spinal cords obtained post-mortem. The highest content of 5-HT, 5-HIAA and NE was found in the lumbar enlargement of the spinal cord. 5-HT and 5-HIAA content increased from fetal to adult spinal cord whereas the content of NE decreased. Characteristic segmental distribution of measured monoamines was present in adult spinal cord only. In two patients spinal cord lesion led to the reduction in spinal cord content of 5-HT, 5-HIAA and NE and loss of characteristic segmental distribution of these substances. These results are in general agreement with observations on spinal cord of different animal species. 相似文献
15.
We correlated MRI features with histopathological findings in an HIV-positive patient with vacuolar myelopathy. On MRI symmetrical
nonenhancing high-signal areas in the posterior columns on T2-weighted images result from extensive vacuolation visible on
histological sections.
Received: 18 November 1997 Accepted: 23 March 1997 相似文献
16.
E. M. Robertson R. C. Miall 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1997,117(1):148-152
The human arm is kinematically redundant, which may allow flexibility in the execution of reaching movements. We have compared
reaching movements with and without kinematic redundancy to unpredictable double-step targets. Subjects sat in front of a
digitising tablet and were able to view an arc of four targets reflected in the mirror as virtual images in the plane of the
tablet. They were instructed to move, from a central starting point, in as straight a line as possible to a target. In one-third
of trials, the target light switched to one of its neighbours during the movement. Subjects made 60 movements using shoulder,
elbow and wrist and then another 60 movements in which only shoulder and elbow movement were allowed. By restraining the wrist,
the limb was made non-redundant. The path length was calculated for each movement. In single-step trials, there was no significant
difference between path lengths performed with and without wrist restraint. As expected there was a significant increase in
path length during double-step trials. Moreover this increase was significantly greater when the wrist was restrained. The
variability across both single- and double-step movements was significantly less while the wrist was restrained. Importantly
the performance time of the movements did not alter significantly for single-step, double-step or restrained movements. These
results suggest that the nervous system exploits the intrinsic redundancy of the limb when controlling voluntary movements
and is therefore more effective at reprogramming movements to double-step targets.
Received: 24 March 1997 / Accepted: 7 July 1997 相似文献
17.
大气中不同粒径颗粒物诱导人羊膜FL细胞UDS的研究 总被引:3,自引:0,他引:3
本研究以诱导人羊膜细胞UDS为指标,对太原市大气不同粒径的颗粒物提取液进行了致突变性检验,结果表明,不同粒径颗粒物的提取液均可产生一定的遗传毒性,尤以3.3μm以下的颗粒物的遗传毒性较强。 相似文献
18.
In human Y-79 retinoblastoma cells corticotropin-releasing hormone (CRH) produces a marked and rapid increase of adenylate cyclase activity. The concentration of the peptide producing half-maximal stimulation is 60 nM. The effect of CRH is significantly antagonized by the specific CRH receptor antagonist alpha-helical CHR 9-41 and is mimicked by sauvagine and urotensin I, two peptides displaying sequence homology with CRH. These results demonstrate the presence of functional CRH receptors in human Y-79 retinoblastoma cells and suggest that this cell line may be a suitable model in which to study the action of CRH on human retinal cell function. 相似文献
19.
Evidence for the presence of substance P-like immunoreactivity in the human cerebellum 总被引:1,自引:0,他引:1
M. Del Fiacco M. T. Perra M. Quartu M. D. Rosa G. Zucca M. C. Levanti 《Brain research》1988,446(1):173-177
Preliminary results on the localization of substance P-like immunoreactivity in the human cerebellum are presented. Cerebella from newborn and adult subjects were examined. While only sporadic positive fibres were detected in the adult tissue, the immunoreactive material appeared more abundant in the cerebella from newborn subjects. Varicose and non-varicose fibres and dot-like nerve terminals were present with different density in various regions. The paucity of immunoreactive perikarya suggests that most of the cerebellar substance P-like immunoreactive material has an extrinsic origin. 相似文献
20.
Peter Van Gelder Sergey Lebedev Wai Hon Tsui 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1997,116(2):201-215
Smooth pursuit typically includes corrective catch-up saccades, but may also include such intrusive saccades away from the
target as anticipatory or large overshooting saccades. We sought to differentiate catch-up from anticipatory and overshooting
saccades by their peak velocities, to see whether the higher velocities of visually rather than nonvisually guided saccades
in saccadic tasks may be found also in saccades in pursuit. In experiment 1, 12 subjects showed catch-up, anticipatory, and
overshooting saccades to comprise 70.4% of all saccades in pursuit of periodic, 30°/s constant-velocity targets. Catch-up
saccades were faster than the others. Saccadic tasks were run as well, on 19 subjects, including the 12 whose pursuit data
were analyzed, with target-onset, target-remaining (saccade to the remaining target when the other three extinguish), and
antisaccade tasks. For 17 of the 19 subjects, antisaccade velocities were lower than for either target-onset or target-remaining
tasks. Velocities for the target-remaining task were near those for target onset, indicating that target presence, not its
onset, defines visually guided saccades. Error and reaction-time data suggest greater cognitive difficulty for target remaining
than for target onset, so that the cognitive difficulty of typical nonvisually guided saccade tasks is not sufficient to produce
their lowered velocity. To produce reliably, in each subject, catch-up and anticipatory saccades with comparable amplitude
distributions, nine new subjects were asked in experiment 2 to make intentional catch-up and anticipatory saccades in pursuit,
and were presented with embedded target jumps to elicit catch-up saccades, all with periodic target trajectories of 15°/s
and 30°/s. Velocities of intentional anticipatory saccades were lower than velocities of intentional catch-up saccades, while
velocities of intentional and embedded catch-up saccades were similar. Target-onset and remembered-target saccadic tasks were
run, showing the expected higher velocity for the target-onset task in each subject. Both experiments demonstrate higher peak
velocities for catch-up saccades than for anticipatory saccades, suggesting that cortical structures preferentially involved
in nonvisually guided saccades may initiate the anticipatory and overshooting saccades in pursuit.
Received: 1 December 1995 / Accepted: 25 February 1997 相似文献