共查询到20条相似文献,搜索用时 31 毫秒
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J. R. Fry 《Comparative Haematology International》1992,3(1):4-7
There are three principal pressures driving the development of in vitro toxicology: (1) the need for more efficient testing systems to cope with the large number of xenobiotics currently being developed; (2) public pressure to reduce animal experimentation; and (3) a need for a better understanding of the mechanisms of toxicity. Within this, in vitro toxicology is focused on local, systemic, and target-organ toxicity. It is becoming increasingly apparent that a step or decision-tree approach using input of a variety of experimental data (physicochemical properties, biokinetics, cytotoxicity) provides the most efficient system for predicting toxicity. Examples of the use of in vitro toxicity systems for prediction of systemic toxicity and target-organ (liver) toxicity are presented.Originally presented at ECCP 93. 相似文献
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J. Logar B. oba T. Premru-Sren . Novak-Antoli 《Clinical microbiology and infection》2005,11(10):852-855
Between December 1999 and December 2004, 40 081 pregnant women were examined for toxoplasmosis with Toxo-IgG, Toxo-IgM enzyme immunoassay. Women with positive results were then retested with the Toxo-IgG avidity assay for recent toxoplasmosis. Recent acute toxoplasmosis in pregnant women was found to be significantly more frequent (p < 0.01) during winter than summer. The incidence of acute toxoplasmosis during winter-spring was also significantly more frequent (p < 0.025) than summer-autumn. This phenomenon should be taken into account when formulating preventive measures for toxoplasmosis, especially for pregnant women. 相似文献
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Adrenomedullin (AM) is a new peptidergic regulator of vascular function. AM serves as a hormone, which has many biological properties, plays an important role in the many pathophysiological processes, especially shock. This review will highlight the structure, biological properties of AM and the relationship between AM and shock. 相似文献
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Polyamines putrescine, spermidine and spermine are positively charged aliphatic amines and have important roles in maintaining normal cellular function, regulating neurotransmitter receptors and modulating learning and memory. Recent evidence suggests a role of putrescine in hippocampal neurogenesis, that is significantly impaired during aging. The present study measured the polyamine levels in memory-related brain structures in 24- (aged), 12- (middle-aged) and 4- (young) month-old rats using liquid chromatography/mass spectrometry and high performance liquid chromatography. In the hippocampus, the putrescine levels were significantly decreased in the CA1 and dentate gyrus, and increased in the CA2/3 with age. Significant age-related increases in the spermidine levels were found in the CA1 and CA2/3. There was no difference between groups in spermine in any sub-regions examined. In the parahippocampal region, increased putrescine level with age was observed in the entorhinal cortex, and age did not alter the spermidine levels. The spermine level was significantly decreased in the perirhinal cortex and increased in the postrhinal cortex with age. In the prefrontal cortex, there was age-related decrease in putrescine, and the spermidine and spermine levels were significantly increased with age. This study, for the first time, demonstrates age-related region-specific changes in polyamines in memory-associated structures, suggesting that polyamine system dysfunction may potentially contribute to aged-related impairments in hippocampal neurogenesis and learning and memory. 相似文献
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C Prado 《Annals of human biology》1984,11(2):165-166
The age at menarche was estimated by recollection in 1617 women between the ages of 18 and 60 in Madrid and a nearby suburb, Pinto. The population of Pinto is working-class and the Madrid group, taken from residential neighbourhoods , belongs to the upper middle class. In both groups we found a diminution in average age at menarche, from 14.04 to 13.02 years in Madrid and from 14.55 to 13.16 years from about 1935 to about 1965 in Pinto. These changes have been more intense in the group which is less well-off economically, where living conditions have varied much more drastically. 相似文献
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At rest the cAMP concentration in (muscle samples of) the quadriceps femoris ranged from 1.55 to 3.00 μmol per kg dry muscle and in plasma from 15.3 to 32.3 nmol per 1. Blockade of the beta adrenoreceptors with propranolol resulted in a significant decrease in the concentration in muscle at rest, the magnitude of the fall being related to the inital level. Similarly in plasma there was a trend towards lower levels of cAMP in those with the highest pretreatment levels, but the overall change was not statistically significant. There was no relation between the concentrations in muscle and plasma, before or after beta-blockade. Maximum dynamic exercise for 4–8 min resulted in an approximate doubling in the cAMP concentration in both muscle and blood. The increase in plasma was closely related to that in muscle. Beta-blockade inhibited totally the rise in cAMP in muscle during exercise but was marginally less effective in preventing the increase in blood. No increase in plasma or muscle cAMP levels during 40–70 s isometric contraction were observed. 相似文献
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Varcasia A Garippa G Pipia AP Scala A Brianti E Giannetto S Battelli G Poglayen G Micagni G 《Parasitology research》2008,102(4):815-818
Between March 2003 and February 2007, the livers and the lungs of 2,231 horses from various Italian regions were examined
for cystic echinococcosis presence at the time of slaughter. Hydatid cysts were found in six horses, namely four from Sardinia,
one from Sicily, and one from Tuscany. The location, number, morphology, and fertility of the cysts found were determined.
DNA was extracted from the germinal layers and protoscoleces of the fertile cysts and polymerase chain reactions (PCR) were
performed in order to strain type DNA isolates for reduced nicotinamide adenine dinucleotide dehydrogenase subunit 1 (ND1),
cytochrome c oxidase subunit 1 (CO1) and 12S partial genes. The PCR products were then purified and sequenced in forward and
reverse. Hydatid materials obtained from positive animals were identified as Echinococcus granulosus s.s. (old G1, sheep strain) and Echinococcus equinus (old G4, horse strain) for ND1, CO1, and 12S partial genes. This allowed us to record the presence of the E. equinus in Italy for the first time with molecular tools and also to report new data on the epidemiological situation of this parasite
in Italy. 相似文献
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随着对生物力学与力学生物学机制理解的深入,力学如何应用于疾病治疗受到越来越多的关注,由此产生了力治疗学这一新兴领域。 生物材料与力治疗学的结合,为疾病的力学治疗提供了多样化的干预途径与丰富的技术手段。 本文结合 2022 年度生物材料在力治疗学中应用的最新进展,着眼于多尺度的力治疗途径分析,从器官与组织、微组织、细胞与亚细胞和分子 4 个尺度,探讨生物材料如何服务于力治疗学应用,以期助力多学科交叉研究发展、推动力治疗研究的转化与应用。 相似文献
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《Journal de Mycologie Médicale》2020,30(3):101005
The epidemiological, clinical and anatomopathological aspects of pythiosis in cats in northeastern Brazil are described. From January 2000 to December 2018 the Laboratory of Animal Pathology of the Federal University of Campina Grande received 1928 tissue samples of cats, three of which were diagnosed as pythiosis. Grossly, the cats showed a multinodular mass in the oral cavity associated with facial deformity (case 1), a large multinodular mass thickening the jejunum wall (case 2), and an ulcerated nodule in the skin at the base of the tail (case 3). Histologically, pyogranulomatous inflammation and necrosis, with intralesional predominantly negatively stained hyphae, were observed in all cases. Immunohistochemistry for Pythium insidiosum revealed strong immunolabelling of the hyphae. The diagnosis of pythiosis was based on the epidemiological, clinical and anatomopathological findings, and was confirmed by immunohistochemistry. Although uncommon in cats, pythiosis should be readily considered as a differential diagnosis of chronic pyogranulomatous infections of the gastrointestinal tract and skin, especially in endemic areas, where the disease is often diagnosed in other animal species. 相似文献
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Summary Uteroglobin (UGL) was measured in day- 4 to day-10 rabbit conceptuses by a competitive ELISA. Levels in blastocyst fluid, tissues, coverings and in the early fetus were determined separately. The total amount of UGL increased from 18.4 ng to 6.8 g per conceptus. The UGL content of individual day-6 blastocysts was studied in vitro. Culturing was carried out up to 60 h in Ham's F10 medium with polyvinylpyrrolidone as macromolecular component, with and without progesterone, and with progesterone plus estradiol. UGL was determined in the blastocyst fluids, tissues with coverings and in the culture media. After labelling with [35S]-methionine, protein patterns of total blastocysts and of culture media were analysed by two-dimensional gel electrophoresis and fluorography. The morphology of cultured blastocysts was examined by electron microscopy. During 60 h of culture, the blastocysts expanded in diameter by 84%, and released 19% of their initial UGL content into the medium, independent of the hormonal substitution. Neither de novo synthesis, nor degradation of UGL was found: the protein remained unlabelled in fluorography, and its total quantity was not significantly different from that of non-cultured controls. Trophoblast, endoderm and embryoblast cells showed well preserved cell organelles and intercellular junctions, while the morphological differentiation of the germ layer was inhibited. 相似文献
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Braunschweig R Guilleret I Delacrétaz F Bosman FT Mihaescu A Benhattar J 《Diagnostic cytopathology》2001,25(4):225-230
Telomerase has been found to be reactivated in a majority of cancers but is inactive in most somatic cells. Our principal goal was to determine the potential use of the telomeric repeat amplification protocol (TRAP) assay as marker for malignancy in cytological effusions. The simple selection criterion was the cytological diagnosis, and routine samples were classified into malignant (58 samples) and nonmalignant (233 samples). Of the malignant samples, 44/58 (76%) were positive by TRAP assay. Of the 14 telomerase-negative cytology-positive samples, RNA integrity was poor in 9, indicating suboptimal sample conservation for molecular analysis. In 3 of the remaining 5 samples with a negative TRAP assay, a high number of malignant cells was observed, and these cells might have been telomerase-negative. Thus, the sensitivity of TRAP assay for the presence of malignant cells was about 76%. In the cytologically nonmalignant effusions, the presence of telomerase activity was observed in 24% (55/233). Of these, 6% were highly suspicious for malignancy, 9% were doubtful, and 9% were cytologically nonmalignant effusions confirmed by a follow-up of 12 mo or more. According to these data, the specificity of the TRAP assay to detect tumor cells in effusions ranged only between 82-91%. Our results indicate that, although the TRAP assay is positive in 6-15% of putative malignant effusions, the relatively high number of TRAP false-negative and false-positive cases renders this test unsuitable for routine diagnostic purposes. 相似文献
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Priv.-Doz. Dr. Carl Michael Büsing Ulrich Keppler Volker Menges 《Virchows Archiv : an international journal of pathology》1981,393(3):307-313
Summary Microcalcifications in benign and malignant tumors can be analyzed by X-ray diffraction and electron microprobe analysis in human specimen. Our systematic investigations revealed calcium hydroxyapatite in cases of invasive carcinoma but calcium oxalate (weddelite) in proliferating but non-invasive diseases. The differences in calcification depending on the underlying disease may indicate basic differences in cell metabolism. 相似文献
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目的 探讨肩胛骨出固定治疗飘浮肩的必要性。方法 自2001年12月至2004年9月通过手术对锁骨和肩胛骨均行切复内同定治疗飘浮肩患者12例。结果 术后12例均获得随访,随访时间4个月至3年,平均2年。其中优7例,良3例,差3例(术前合并臂丛神经损伤3例)。结论 对飘浮肩患者,锁骨和肩胛骨均应行内固定,可获得满意的临床疗效。 相似文献
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Trends in pubertal development in Europe 总被引:8,自引:0,他引:8
The secular changes in growth and maturation can be seen as indicators of socio-economic and health status. In most European countries the age of onset of puberty and of menarcheal age has been decreasing during the past few decades. The duration of puberty seems also to decrease, though few studies provide sufficient data to support this postulation. The four Dutch nationwide growth surveys are useful examples assessing the secular trend in pubertal development over the past 45 years. Genetic and environmental factors contribute to the secular changes. Environmental factors seem to be the most important. Recently, attention has been given to substances with oestrogen-like actions that are present in nutrients. The possible role of these substances in growth and maturation is discussed. 相似文献
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目的了解泉州市2009年流感活动情况及其型别特征。结论通过流行病学和病原学监测,对泉州市流感流行情况进行分析。结果 2009年全市流感样病例占就诊人数的0.26%~2.34%;全年采集监测标本1392份,经RT-PCR法检测样本阳性率为22.34%;经MDCK细胞分离流感毒株134株,其中季节性H3N2和HINl型各占60.45%和11.19%,甲型H1N1流感占21.64%,B型占6.70%。结论 2009年泉州市流感春夏季以季节性H3N2亚型流感为优势毒株,秋冬季以甲型H1N1流感为流行株,需加强泉州市流感监测和流感病毒抗原变异研究。 相似文献
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Lv SQ Kim YH Giulio F Shalaby T Nobusawa S Yang H Zhou Z Grotzer M Ohgaki H 《Brain pathology (Zurich, Switzerland)》2012,22(2):230-239
MicroRNAs (miRNAs) regulate a variety of cellular processes via the regulation of multiple target genes. We screened 48 medulloblastomas for mutation, deletion and amplification of nine miRNA genes that were selected on the basis of the presence of potential target sequences within the 3′‐untranslated region of the MYCC mRNA. Differential PCR revealed deletions in miR‐186 (15%), miR‐135a‐1 (33%), miR‐548d‐1 (42%), miR‐548d‐2 (21%) and miR‐512‐2 (33%) genes, whereas deletion or amplification was detected in miR‐135b (23%) and miR‐135a‐2 (15%). In miR‐33b, deletion, amplification or a mutation at the precursor miRNA were detected in 10% of medulloblastomas. Overall, 35/48 (73%) medulloblastomas had at least one alteration. Real‐time RT‐PCR revealed MYCC overexpression in 11 of 37 (30%) medulloblastomas, and there was a correlation between MYCC overexpression and miR‐512‐2 gene deletion (P = 0.0084). Antisense‐based knockdown of miR‐512‐5p (mature sequence of miR‐512‐2) resulted in significant upregulation of MYCC expression in HeLa and A549 cells, while forced overexpression of miR‐512‐2 in medulloblastoma/PNET cell lines DAOY, UW‐228‐2, PFSK resulted in the downregulation of MYCC protein. Furthermore, the results of luciferase reporter assays suggested that miR‐512‐2 targets the MYCC gene. These results suggest that alterations in the miRNA genes may be an alternative mechanism leading to MYCC overexpression in medulloblastomas. 相似文献