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101.
综述了番红花属植物近期的化学及药理研究情况,主要集中在对其柱头中类胡萝卜素及胡萝卜素类化合物的分离及鉴定上;对一些化合物抗癌活性的研究相对集中。 相似文献
102.
评价低温保存板层角膜移植材料的效果。方法将15只人尸角膜分三组保存2年:4℃甘油脱水法,角膜液氮冷冻法,全眼球液氮冷冻法。并做透射电镜观察。结果第一组中,角膜胶原纤维排列紊乱,疏松,缺乏连续性,可见广纤维变性,纤维间可见极低电子密度灶。 相似文献
103.
Gao J Gross J Andreeva N Glatzel E Grützmann H Heldt J Husemann B Jamielson L Andersson K 《Journal of neural transmission (Vienna, Austria : 1996)》1999,106(2):111-122
Summary. Perinatal hypoxia is known as a high risk factor for the development of long-lasting abnormalities in dopaminergic system.
The early developmental alterations of dopamine (DA) metabolism induced by hypoxia could contribute to these abnormalities.
To understand the hypoxia-induced changes of intra- and extracellular dopamine levels and its main metabolites, 3,4-dihydroxyphenylacetic
acid (DOPAC) and homovanillic acid (HVA), in immature dopaminergic neurons, we compared these changes in rat mesencephalic
and diencephalic cell cultures on day in vitro (DIV) 2 (immature cells), DIV 8 and DIV 13 (mature cells). Cell cultures were
exposed to an oxygen-free gas mixture in a Billups chamber for 2–4 hours. Mature cell cultures responded to hypoxia with an
increase of DA levels in the cells and in the medium during the first 45 min (by an average of 57 and 114% respectively).
Thereafter, DA levels decreased, and returned to the baseline within the next 30 min. The cellular DA levels continued to
decrease up to 15% of the baseline during 255 min hypoxia whereas the extracellular DA content stabilized at the prehypoxic
levels. Immature cell cultures (DIV 2) in contrast to mature ones, were unable to maintain normal extracellular DA levels
during hypoxia and showed a decrease of the cellular and extracellular levels to 50% of the prehypoxic levels. DOPAC and HVA
changes mimick, however, at a lower level, the pattern of DA changes during the exposure to hypoxia. In principle, in the
diencephalic cell culture similar effects of hypoxia exposure on the investigated parameters were found (studied during 0–120
min).
The present study demonstrates that mature and immature dopaminergic cells differ in the regulation of the extra- and intracellular
DA levels during hypoxia. In immature cells the low synthetic capacity of tyrosine hydroxylase and the deficient capacities
of the transport and storage processes result in decreased extracellular DA levels. This could be an important factor for
the long-term modulation of the expression of tyrosine hydroxylase and subsequent long-term behavioral and/or neurological
abnormalities induced by perinatal hypoxia.
Received June 8, 1998; accepted July 21, 1998 相似文献
104.
105.
IntroductionLipoprotein(a)[Lp(a)]consistsofanLDLparticle,inwhichapolipoprotein(a)isatachedtoapolipoproteinB-100throughadisulf... 相似文献
106.
Y Q Gao M Danciger R Longmuir N I Piriev D Y Zhao J R Heckenlively G A Fishman R G Weleber S G Jacobson E M Stone D B Farber 《Investigative ophthalmology & visual science》1999,40(8):1818-1822
PURPOSE: To screen the exons of the gene encoding the alpha'-subunit of cone cyclic guanosine monophosphate (cGMP>phosphodiesterase (PDE6C) for mutations in a group of 456 unrelated patients with various forms of inherited retinal disease, including cone dystrophy, cone-rod dystrophy, macular dystrophy, and simplex/multiplex and autosomal recessive retinitis pigmentosa. METHODS: The 22 exons of the PDE6C gene were screened for mutations either by denaturing gradient gel electrophoresis and single-strand conformation polymorphism electrophoresis (SSCP) or by SSCP alone; variants were sequenced directly. RESULTS: Although many sequence variants were found, none could be associated with disease. CONCLUSIONS: The results show that PDE6C was not the site of the amutations responsible for the types of inherited retinal degenerations analyzed in the large population of patients 'in the present study. The types of degeneration included those that predominantly affect cone-mediated function (cone and cone-rod dystrophies) or rod-mediated function (retinitis pigmentosa) or that have a predilection for disease in the macula (macular dystrophies). 相似文献
107.
Honn KV Aref A Chen YQ Cher ML Crissman JD Forman JD Gao X Grignon D Hussain M Porter AT Pontes JE Powell I Redman B Sakr W Severson R Tang DG Wood DP 《Pathology oncology research : POR》1996,2(1-2):98-109
Rates of prostate cancer (PCa) have increased so dramatically over the last decade that the age adjusted incidence rate for PCa is now greater than that any other cancer among men in the United States. This review, published as a three part series, provides a state-of-art assessment of the PCa problem in its divergent aspects.Part 1 covers epidemiology, incidence and progression. Several epidemiological studies have demostrated that first degree male relatives of men with PCa are at increased risk of developing the disease. Familial and genetic factors as well as medical, anthropometric, dietary, hormonal and occupational factors involved in PCa are discussed. Postmortem examination of the prostate in men without evidence of PCa documented a high frequency of adenocarcinoma. Latent disease occurred as early as the second decade of life. Although there is no significant difference in incidence between Caucasian and African-American males, high grade prostatic intraepithelial neoplasia (HGPIN) is higher in the latter group. While dietary fat, androgens and certain environmental factors may be determinants for PCa, the exact mechanism of tumorigenesis is still relatively unknown. The current thinking of the role of genomic instability, chromosomal alterations, tumor suppressor genes and the androgen receptor are explored. 相似文献
108.
X Gao 《中华神经精神科杂志》1991,24(6):362-4, 384
Three cases of "Top of the basilar" syndrome are reported. The clinical manifestations included the consciousness disturbance, pupillary and oculomotor abnormalities. One of the 3 cases got cortical blindness. It is emphasized that the possibility of the TOB syndrome should be considered when unconsciousness arose suddenly, accompanied by lid, pupil and oculomotor disturbances without the motor and sensory disturbances. Usually, a bilateral symmetric butterfly hypodensity could be found in the thalamus on CT scan. In addition. It was valuable findings that the infarct lesions have been shown in the mesencephalon, pons, cerebellum, occipital and medial temporal lobe on CT scans. 相似文献
109.
Campylobacter jejuni is a major cause of human enteritis which mimics the inflammatory bowel disease (IBD). In this study, microstructural changes on the surfaces of the murine gastrointestinal tract persistently colonized by Campylobacter jejuni, strain GJ-S131, were investigated by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results revealed that the appearance of the gastrointestinal mucosa in both BALB/C and KM mice resembled that in human with inflammatory bowel disease. Under SEM, the mucosa of the jejunum and ileum, with broken or distorted villi had a "worm eaten" look; crypts were irregular in shape and size, and the mucosa showed atrophy, especially in the colon. Epithelial junctions demonstrated furrows, clefts or deep crevasses, with exudates containing a large number of leukocytes. Cytologic appearances were characterized by microvilli dysplasia and/or atrophy, patchy erosions or necrosis and pelade-like appearance due to absence of microvilli, which were similar to the findings under TEM.
相似文献
110.
Longitudinal study of earthquake-related PTSD in a randomly selected community sample in north China 总被引:13,自引:0,他引:13
Wang X Gao L Shinfuku N Zhang H Zhao C Shen Y 《The American journal of psychiatry》2000,157(8):1260-1266
OBJECTIVE: This study longitudinally described rates of posttraumatic stress disorder (PTSD) in two groups with different levels of severity of exposure to an earthquake in North China. The effects of diagnostic criteria on the frequency of detected PTSD were also examined. METHOD: Subjects were randomly sampled in two villages at different distances from the earthquake epicenter. A total of 181 and 157 subjects were assessed at 3 months and 9 months after the earthquake, respectively, for PTSD by using both DSM-IV and DSM-III-R criteria. The brief version of the World Health Organization Quality of Life Assessment and three subscales of the SCL-90-R were also administered at both assessment points. RESULTS: The village with a higher level of initial exposure to the earthquake and a higher level of postearthquake support had a lower frequency of PTSD than the village with a lower level of initial exposure and less postearthquake support. The rate of onset of DSM-IV PTSD within 9 months for the two villages was 19.8% and 30.3%, respectively. In both villages, the rate of onset of earthquake-related PTSD within 9 months was 24.2% by using DSM-IV criteria and 41.4% by using DSM-III-R criteria. The introduction in DSM-IV of a criterion requiring clinically significant distress or impairment in functioning for a diagnosis of PTSD was a major contributor to the lower rate of DSM-IV PTSD. CONCLUSIONS: PTSD may be as prevalent and persistent in disaster victims in China as in those elsewhere. Prompt and effective postdisaster intervention could mitigate the impact of initial exposure and reduce the probability of PTSD occurrence. Caution should be used in comparing rates of postdisaster PTSD identified by using different diagnostic criteria. 相似文献