共查询到20条相似文献,搜索用时 171 毫秒
1.
Firth PG 《The New England journal of medicine》2010,363(14):1378-9; author reply 1380
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Pitts T Morris K Lindsey B Davenport P Poliacek I Bolser D 《Experimental physiology》2012,97(4):469-473
Coughing and swallowing are airway-protective behaviours. The pharyngeal phase of swallowing prevents aspiration of oral material (saliva, food and liquid) by epiglottal movement, laryngeal adduction and clearing of the mouth and pharynx. Coughing is an aspiration-response behaviour that removes material from the airway. Co-ordination of these behaviours is vital to protect the airway from further aspiration-promoting events, such as a swallowing during the inspiratory phase of coughing. The operational characteristics, primary strategies and peripheral inputs that co-ordinate coughing and swallowing are unknown. This lack of knowledge impedes understanding and treatment of deficits in airway protection, such as the co-occurrence of dystussia and dysphagia common in Parkinson's and Alzheimer's diseases, as well as stroke. 相似文献
3.
目的 制备光敏剂5-氨基酮戊酸(ALA)和血卟啉单甲醚(HMME)水凝胶栓剂,评价其对直肠肿瘤组织的光敏剂递送效率.方法 将皮下移植人直肠癌细胞SW837的BALB/c小鼠随机分为水凝胶栓剂直肠局部给药组、皮肤局部给药组、瘤内注射给药组和静脉注射给药组.用荧光光谱仪测量直肠壁、皮肤和皮下肿瘤中原卟啉(PpⅨ)和HMME的浓度,荧光光谱系统测定相应的光敏剂分布情况.结果 ALA水凝胶栓剂直肠局部给药组的PpⅨ浓度分别是皮肤局部给药组的9.76倍(1 h)和5.80倍(3 h),差异均具有统计学意义(均P<0.05).皮肤局部给药后2h,ALA在肿瘤组织内达到最大穿透深度(3~6 mm).而HMME水凝胶栓剂直肠局部给药后,直肠壁中的HMME浓度极低,且皮肤局部给药后的最大肿瘤穿透深度不足2 mm.结论 与皮肤相比,ALA更易穿透黏膜屏障,以水凝胶栓剂形式直肠局部给药有望成为ALA用于光动力疗法治疗直肠癌的一种给药方式. 相似文献
4.
Georg Herbai 《Acta physiologica (Oxford, England)》1970,79(4):541-551
A rapid and simple method for liquid scintillation counting of 33S-sulfate in biological tissues is described. Sulfate incorporation per mg dry weight into selected lateral, medial and intermediate regions of ribs was studied using costal cartilage from rats and mice. In vitro, cartilage pieces embracing the osteochondral junction had 2–4 times larger incorporation rate than the remaining homogeneous parts of the ribs, both if entire rib cages or stripped and diced cartilage were incubated. After in vivo injection to rats and mice the incorporation rates of sulfate into the region of the osteochondral junction was 2.6 times that found in “resting” cartilage in rats and 4.4 times in mice. The 35S-sulfate uptake in the ribs per mg dry cartilage diminished in the caudal direction. Growth of the chest cage was mainly a longitudinal growth of the bony segments. Marked differences in the disappearance rates of previously incorporated sulfate were found in different regions along the rib. Rapid sulfate disappearance was found in the bony segment which, however, had incorporated only one seventh of the amount per mg taken up by “resting” cartilage. The “resting” cartilage segments exhibited a steady slow disappearance rate for sulfate and the osteochondral junction region consisting of several differently active tissues showed a rapid sulfate disappearance in the beginning followed by a slow clearance after 2 weeks similar to that of “resting” cartilage. The necessity of careful selection of costal cartilage samples with respect to regional differences is emphasized. 相似文献
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Tensotremorography was used to record voluntary forces and to study the characteristics of the involuntary and voluntary components of isometrically recorded hand strength. The frequency ranges for changes in the spectral density of oscillations recorded here supported the existence of two suprasegmental systems associated with voluntary control and continuous regulation of force maintaining or holding a posture. Cross-correlation analysis of hand force maintained in conditions of visual feedback in normal conditions and in conditions of central disorders of the movement control system is presented. 相似文献
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Recent advances of imaging techniques have enabled us to investigate the dynamics of synapses in living neurons. The synapse is constructed of presynaptic and postsynaptic elements which contain various kinds of structural and functional molecules. The postsynaptic density (PSD) is the most prominent structure among the excitatory postsynaptic elements. One of the main components of PSD is the scaffolding proteins which interact with multiple proteins in the synapse. Scaffolding proteins are suggested to play key roles in the emergence, maintenance, and remodeling of the excitatory synapses. Several kinds of scaffolding proteins are known to be present in the mammalian and also other vertebrate brains. These proteins were labeled with green fluorescent protein (GFP) and expressed in cultured neurons to analyze the dynamics and turnover of molecules in the synapses. In this review we describe how these molecules behave when the synapse is newly added or eliminated in the steady state and also when neuronal activity is changed. 相似文献
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Anders M Sarbia M Grotzinger C Meining A Hofler H Wiedenmann B Rosch T 《Disease markers》2008,24(6):287-292
In the current study we aimed to clarify the potential of EpCAM and villin as in vivo biomarkers for both Barrett esophagus (BE)-associated neoplasia and BE versus cardiac mucosa. Immunohistochemical staining in BE with various degrees of intraepithelial neoplasia (IN), Barrett carcinoma (BC) and in normal cardiac mucosa (CM) revealed a lack of EpCam and villin in squamous esophageal epithelium. All specimens of IN and BC showed EpCam with varying staining intensities. In 57% of CM samples a weak signal was detected; the remainder displayed strong EpCam expression. Villin was found in 97% of BE specimens and in all those with IN; 37% of BC and 75% of CM specimens were~also positive. We conclude that expression of EpCam and villin differs only between squamous epithelium and BE. Determination of these proteins does not allow discrimination between different degrees of neoplasia or between esophageal intestinal metaplasia and cardiac mucosa. 相似文献
8.
R. L. CARTER† K. P. MCCARTHY† L. G. MACHIN C. F. JAMESON E. R. PHILP† C. R. PINKERTON 《Histopathology》1989,15(6):585-595
Immunohistochemical staining for desmin and myoglobin was investigated in 35 rhabdomyosarcomas from young people and in skeletal muscle from 16 human fetuses of known gestational age. Twenty-nine of the rhabdomyosarcomas expressed desmin but six undifferentiated or poorly-differentiated tumours were desmin negative. Of the desmin positive cases, most undifferentiated or poorly-differentiated sarcomas expressed desmin alone (12/35). Tumours with increasing rhabdomyoblastomic differentiation co-expressed myoglobin (9/35) and well-differentiated examples also contained cross-striations (7/35). Skeletal muscle from fetuses aged 8 weeks or less consisted mainly of primitive desmin negative round cells. As the cells began to differentiate they quickly expressed desmin and, at approximately 10 weeks, myoglobin was expressed and cross-striations were seen. The combined results strengthen the view that desmin (within a strictly defined context of round cell tumours in young people) is a reliable marker for rhabdomyoblastic differentiation. Support is also given to the notion that very primitive rhabdomyosarcomas may be desmin-negative, although the difficulties of establishing firm diagnoses for some of these tumours is emphasized. 相似文献
9.
H. Abe T. Otoi S. Tachikawa S. Yamashita T. Satoh H. Hoshi 《Anatomy and embryology》1999,199(6):519-527
The ultrastructure of bovine morulae and blastocysts developed from in vitro-matured and -fertilized oocytes in a serum-supplemented
medium was compared with that of morulae and blastocysts collected non-surgically from superovulated cows. In the in vivo-derived
morulae, two characteristic cells types could be identified by the electron-density of their cytoplasm and by their ultrastructural
features. One type appeared light in color with low electron-dense cytoplasm. These cells were located in the peripheral layer
of the cluster of blastomeres, possessed numerous cellular organelles such as mitochondria and Golgi apparatus and had microvilli
projecting into the perivitelline space. The other cell type was distinguished by cytoplasm that stained more densely than
that of the lighter-appearing cells. The darker-appearing cells generally possessed fewer organelles than the lighter cells,
but many lysosome-like structures were present in the cytoplasm. The in vitro-developed morulae also contained two types of
cells similar to those observed in the in vivo morulae. However, most of the in vitro-developed cells possessed numerous lipid
droplets and contained fewer lysosome-like structures than the cells of the in vivo-derived morulae. The blastocysts, both
in vivo and in vitro, showed a clear differentiation of trophoblast cells and inner cell mass (ICM)-cells. In the in vivo-derived
blastocyst, the apical membrane of trophoblast cells was covered with large, numerous microvilli and well-developed junctional
complexes were observed. Lipid droplets were present in the cytoplasm of trophoblast and ICM-cells but were not abundant.
In vitro-developed blastocysts showed less well-developed junctional complexes between trophoblast cells, less well-developed
apical microvilli on the trophoblast cells, and contained large numbers of lipid droplets. This accumulation of lipid droplets
was higher in the trophoblast cells than in the ICM-cells. The zonae pellucidae of in vitro-developed embryos were thinner
than that of the in vivo-derived embryos. This study demonstrates conspicuous differences in the ultrastructural features
between the in vivo-derived and in vitro-developed embryos, suggesting that the ultrastructure may reflect the various physiological
anomalies observed in previous studies.
Accepted: 29 October 1998 相似文献
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Filippini A Riccioli A Padula F Lauretti P D'Alessio A De Cesaris P Gandini L Lenzi A Ziparo E 《Human reproduction update》2001,7(5):444-449
It has long been known that the testis is an immunologically privileged site in the body, and that human seminal plasma possesses a generalized immunosuppressive activity. Multiple factors participate in the establishment of immunotolerance in the testis: the blood-tubular barrier; the local production of immunosuppressive molecules by Sertoli cells; and the Fas system as regulator of immunological homeostasis in both physiological and pathological conditions. Cytokine-induced up-regulation of Fas as well as of integrin ligands, which are known to be specific binding molecules for lymphocytes on the Sertoli cell surface, indicates that the 'nursing' cells of seminiferous epithelium might be important in the impairment of immune privilege, causing autoimmune orchitis. In addition, the soluble form of Fas-ligand protein present in the seminal plasma of infertile patients might suggest a role for this immunomodulatory protein in male infertility. Finally, an understanding of the mechanisms underlying immune privilege in the testis and in semen might help to clarify how cells expressing 'non-self' antigens (such as male gametes) can escape the immune system in both the male and female genital tracts. 相似文献
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A. Mangogna C. Agostinis G. Ricci F. Romano R. Bulla 《Clinical and experimental immunology》2019,198(1):37-46
Procalcitonin (PCT), a precursor for calcitonin, is a prohormone involved in the inflammatory processes, which has been poorly studied in the context of pregnancy. During severe inflammation, PCT derives from almost all cell types, including monocytes and parenchymal tissues, making it a good predictive and diagnostic marker of an inflammatory state with rapidly increased serum levels in inflammation or sepsis. In normal pregnancy, PCT is basally expressed at very low level by decidual cells, even if decidual macrophages, which in normal pregnancy are skewed to M2 macrophages, are resistant to lipopolysaccharide (LPS)-induced production of PCT. As PCT increase is associated with an inflammatory state, several research groups investigated whether PCT can be considered a marker of pre-eclampsia, a pregnancy disease characterized by systemic inflammation. The first aim of this review is to summarize what is already known about the tissues synthesizing PCT, about the stimuli that cause the increase of circulating PCT levels and how PCT acts as a proinflammatory stimulus by itself. Secondly, we will describe the role of this prohormone in normal pregnancy and in pregnancies complicated by pre-eclampsia, highlighting the involvement of the decidual macrophages and the proinflammatory cytokine tumor necrosis factor-α in the modulation of PCT expression in the decidual microenvironment. 相似文献
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Honghui Lu Lihai Zhang Daohong Liu Peifu Tang Feixiang Song 《African health sciences》2014,14(3):641-647
Background
Modern studies have shown that psoralen has a significant inhibitory effect on tumor growth in a variety of animals and humans.Objective
To obtain coumarin compounds — psoralen and isopsoralen — from traditional Chinese medicine Psoralea corylifolia L. using chromatographic techniques and isolation and purification methods, and to observe the transplanted tumor growth inhibitory effects and adverse reactions of psoralen and isopsoralen in nude rats with osteosarcoma.Methods
Dried ripe fruits of Psoralea corylifolia L. were taken as the raw material to prepare crude extract of Psoralea corylifolia L. by ethanol reflux method. Column chromatography was used to isolate the crude extract; compounds were structurally identified based on 1H-NMR, 13C-NMR spectra, the two compounds were identified as psoralen andisopsoralen, and their contents were 99.7% and 99.6, respectively. Nude rat model of osteosarcoma was established; the rats were randomized into: normal saline group, psoralen low- and high-dose groups, isopsoralen low- and high-dose groups, and cisplatin group. Osteosarcoma volume and weight inhibition rates in nude rats in each group were observed; radioimmunoassay was used to determine the serum alkaline phosphatase activity; peripheral blood cell and bone marrow nucleated cell counts were determined; light microscopy was used to observe heart, liver, spleen, lung, kidney, and tumor histopathology; and electron microscopy was used to observe the fine structure of tumor cells.Results
Tumor volume inhibition rates were 43.75% and 40.18%, respectively, in the psoralen and isopsoralen low-dose groups, and tumor weight inhibition rates were 38.83% and 37.77%. Tumor volume inhibition rates were 67.86% and 66.96%, respectively, in the psoralen and isopsoralen high-dose groups, and tumor weight inhibition rates were 49.47% and 47.87%. Psoralen and ispsoralen markedly lowered serum AKP level. Psoralen and isopsoralen induced apoptosis or necrosis of osteosarcoma. After administration of high doses of psoralen and isopsoralen, toxic reactions such as writhing, lassitude, and hypoactivity were seen. Kidney histopathology showed tubulointerstitial dilatation and congestion, and inflammatory cell aggregation in the renal intercellular space. Psoralen and isopsoralen did not cause any significant toxic side effects to the bone marrow, or other organs such as heart, lung, liver, and spleen.Conclusion
Psoralen and isopsoralen have growth inhibitory effects on transplanted tumor in nude rats with osteosarcoma, and can induce tumor cell apoptosis or necrosis, without significant toxic effects. 相似文献16.
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Selenium deficiency in rats impairs the ability of neutrophils and peritoneal macrophages to kill Candida albicans organisms in vitro. In contrast, killing of Salmonella typhimurium and Staphylococcus aureus organisms is unaffected by the deficiency. Survival of rats after intraperitoneal injection of 8 X 10(7) S. aureus organisms was not affected by Se deficiency, but a 5-fold increase in the dose (4 X 10(8) S. aureus organisms) led to a significantly greater mortality in the Se deficient rats. 相似文献
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《Seminars in Neuroscience》1995,7(6):421-431
Ascending and descending efferent pathways from the nuclei of serotonergic neurones located in brainstem raphe nuclei project to all regions of the central nervous system. Therefore, in considering the major physiological roles played by this neurotransmitter system, it is not surprising that serotonin is implicated in the aetiologies of many CNS dysfunctions which underlie psychiatric and neurological disorders. The presynaptic serotonin uptake mechanism and the many receptor subtypes that mediate the neurotransmitter roles of serotonin have been, and continue to be, targeted by drug discovery programmes aimed at identifying improved therapies for CNS disorders. Here we review the radioligands available for the important task of visualizing and characterizing these targets in the living human brain using either positron emission tomography (PET) or single photon emission tomography (SPECT). Such studies are crucial for extending our knowledge of the involvement of serotonin neurotransmission in the aetiologies of these disorders and for the development of new and more effective therapies. Particularly important recent advances in the methodologies for imaging the 5-HT transporter, the 5-HT2A receptor and the 5-HT1A receptor will almost certainly lead to important clinical research into the changes occurring in serotonergic neurotransmission during the onset, progression and treatment of affective and neurodegenerative disorders. 相似文献
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