共查询到20条相似文献,搜索用时 15 毫秒
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Cooper TG 《Human reproduction (Oxford, England)》2005,20(1):9-11
The term cytoplasmic droplets is used to mean two different structures by basic scientists and clinicians. The literature on the presence, position and loss of cytoplasmic droplets and their relationship to infertility in animal species is reviewed. It is proposed that a change in terminology is required: 'cytoplasmic droplet' should be used to describe normal droplets associated with functional sperm produced by normal spermatogenesis and 'excess residual cytoplasm' is suggested to describe abnormal droplets associated with dysfunctional sperm that are products of faulty spermatogenesis. 相似文献
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Speirs V 《The Journal of pathology》2002,197(2):143-147
Two oestrogen receptors (ERs), ER alpha and ER beta, have been identified. ER alpha is by far the better characterized and is an established predictive marker in breast cancer which influences decisions on whether or not to give adjuvant anti-oestrogens, such as tamoxifen. In contrast, the function of ER beta in breast pathobiology is unclear, partly because most studies have focused on its mRNA rather than the protein. In this review, the significance of ER beta in the human breast is reviewed with respect to recent literature and its possible implications are discussed. 相似文献
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Velísková J 《Neuroscience》2006,138(3):837-844
Estrogens influence neuronal activity and are important for normal brain functions. Effects of estrogens on seizures are contradictory. It is commonly accepted that estrogens may increase neuronal excitability and thus mediate proconvulsant effects. However, clinical and animal data show that estrogen may also have no effect or anticonvulsant effects. The action of estrogens on seizures depends on various factors, such as treatment duration and latency prior to the seizure testing, estrogen dose, hormonal status (naïve vs gonadectomized animals), estrogenic substance, the region/neurotransmitter system involved, the seizure type/model used, and sex. 相似文献
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Caulfield T, Ries NM, Ray PN, Shuman C, Wilson B. Direct‐to‐consumer genetic testing: good, bad or benign? A wide variety of genetic tests are now being marketed and sold in direct‐to‐consumer (DTC) commercial transactions. However, risk information revealed through many DTC testing services, especially those based on emerging genome wide‐association studies, has limited predictive value for consumers. Some commentators contend that tests are being marketed prematurely, while others support rapid translation of genetic research findings to the marketplace. The potential harms and benefits of DTC access to genetic testing are not yet well understood, but some large‐scale studies have recently been launched to examine how consumers understand and use genetic risk information. Greater consumer access to genetic tests creates a need for continuing education for health care professionals so they can respond to patients' inquiries about the benefits, risks and limitations of DTC services. Governmental bodies in many jurisdictions are considering options for regulating practices of DTC genetic testing companies, particularly to govern quality of commercial genetic tests and ensure fair and truthful advertising. Intersectoral initiatives involving government regulators, professional bodies and industry are important to facilitate development of standards to govern this rapidly developing area of personalized genomic commerce. 相似文献
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Over 20 000 MR systems are currently installed worldwide and, although the majority operate at magnetic fields of 1.5 T and below (i.e. about 70%), experience with 3‐T (in high‐field clinical diagnostic imaging and research) and 7‐T (research only) human MR scanners points to a future in functional and metabolic MR diagnostics. Complementary to previous studies, this review attempts to provide an overview of ultrahigh‐field MR research with special emphasis on emerging clinical applications at 7 T. We provide a short summary of the technical development and the current status of installed MR systems. The advantages and challenges of ultrahigh‐field MRI and MRS are discussed with special emphasis on radiofrequency inhomogeneity, relaxation times, signal‐to‐noise improvements, susceptibility effects, chemical shifts, specific absorption rate and other safety issues. In terms of applications, we focus on the topics most likely to gain significantly from 7‐T MR, i.e. brain imaging and spectroscopy and musculoskeletal imaging, but also body imaging, which is particularly challenging. Examples are given to demonstrate the advantages of susceptibility‐weighted imaging, time‐of‐flight MR angiography, high‐resolution functional MRI, 1H and 31P MRSI in the human brain, sodium and functional imaging of cartilage and the first results (and artefacts) using an eight‐channel body array, suggesting future areas of research that should be intensified in order to fully explore the potential of 7‐T MR systems for use in clinical diagnosis. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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Tom J. P. Verberne 《Journal of clinical psychology》1984,40(6):1433-1434
MMPI data presented by Small, Madero, Gross, Teagno, Leib, and Ebert (1981), contrary to the authors' conclusion, show distinct differences, consistent with the clinical diagnosis in the case of the schizophrenic patients, and suggestive of an affective disorder in the anorexic patients. 相似文献
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Copy number variation, namely regions of the genome that can be either deleted or duplicated in a variable way, has emerged as an important source of genetic variance in the human genome. Genes with immunological functions are particularly prone to copy number variation, in part because this is a mechanism to expand the recognition repertoire; however, immunological genes not directly involved in immune recognition are also copy number variable but, despite the link between immunological function and copy number variation, very few copy number variants (CNVs) have been found to be associated with autoimmune diseases, even in recent large genome-wide CNV-association studies. Nonetheless, CNVs in FCGR3B, DEFB4, CCL3L1, C4A/B and NCF1 have been suggested to be associated with autoimmune diseases, although there is conflicting evidence in all cases. The reasons for the lack of definitive data on CNV-autoimmunity associations, as well as the technical challenges for the field are the focus of this review. 相似文献
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Shirley A. Cotton Ariane L. Herrick Malcolm I. V. Jayson Anthony J. Freemont 《The Journal of pathology》1998,184(1):4-6
Systemic sclerosis (SSc) is a multisystem connective tissue disorder in which there is progressive fibrosis. Transforming growth factor beta (TGFβ) has wide-ranging cellular actions. It is a potent chemoattractant for human dermal fibroblasts, from which it may induce synthesis of collagen, which suggests that it may have a central role to play in the pathogenesis of SSc. This is supported to some extent by in vitro studies. SSc fibroblasts produce more collagens and fibronectin than normal fibroblasts and elevated TIMP levels have been observed, all of which could be explained on the basis of TGFβ stimulation of fibroblasts. Some studies have suggested that fibroblasts are the source of TGFβ. However, the serum of patients with SSc is cytotoxic to endothelial cells, which could culminate in TGFβ synthesis by them, with secondary fibroblast stimulation. The role of TGFβ remains elusive, although it would seem an ideal candidate as a mediator of fibrosis in systemic sclerosis. © 1998 John Wiley & Sons, Ltd. 相似文献
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Asthma and atopy – the price of affluence? 总被引:2,自引:0,他引:2
Irrespective of improved knowledge of many aspects of atopic diseases, the unfavorable trends in their prevalence particularly among children could not have been reversed. A growing body of evidence suggests that something may lack from our societal affluence that has the capacity to provide protection against the development of atopic diseases. Much attention during the last years has been devoted to the hygiene hypothesis. This review outlines the impact of environment and lifestyle, particularly from the perspective of the East-West gradient, on the development of atopic diseases, with a special emphasis on the hygiene hypothesis in its broadest sense. 相似文献
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Stenner M Yosef B Huebbers CU Preuss SF Dienes HP Speel EJ Odenthal M Klussmann JP 《Histopathology》2011,58(7):1117-1126
Stenner M, Yosef B, Huebbers C U, Preuss S F, Dienes H‐P, Speel E‐J M, Odenthal M & Klussmann J P (2011) Histopathology 58 , 1117–1126 Nuclear translocation of β‐catenin and decreased expression of epithelial cadherin in human papillomavirus‐positive tonsillar cancer: an early event in human papillomavirus‐related tumour progression? Aims: High‐risk human papillomaviruses (HPVs) constitute an important risk factor for tonsillar cancer. This study describes changes in cell adhesion molecules during metastasis of HPV‐related and HPV‐unrelated tonsillar carcinomas. Methods and results: We examined 48 primary tonsillar carcinoma samples (25 HPV‐16 DNA‐positive, 23 HPV‐16 DNA‐negative) and their respective lymph node metastases for their HPV status and for the expression of p16, epithelial cadherin (E‐cadherin), β‐catenin, and vimentin. A positive HPV‐specific polymerase chain reaction finding correlated significantly with p16 overexpression in both primary tumours and their metastases (P < 0.0001 for both). In HPV‐unrelated carcinomas, the expression of E‐cadherin was significantly lower in metastases than in primary tumours (P < 0.001). In contrast, the expression of nuclear β‐catenin was significantly higher in metastases than in primary tumours (P = 0.016). In HPV‐related carcinomas, nuclear localization of β‐catenin expression was already apparent in primary tumours (P = 0.030). The expression of vimentin significantly correlated with the grading of the primary tumour (P = 0.021). Conclusions: Our data indicate that the down‐regulation of E‐cadherin and the up‐regulation of nuclear β‐catenin expression might be crucial steps during tumour progression of tonsillar carcinomas, being already present in primary tumours in HPV‐driven carcinomas, but becoming apparent in HPV‐unrelated tumours later in the process of metastasis. 相似文献
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The increase in degenerative diseases of the vertebral column is often attributed to an inadequate adaptation to the upright posture in the human. On the basis of a precise analysis of the motion segments, an attempt has here been made to demonstrate that the design of the vertebrae in both the larger mammals and in humans has resulted in no qualitative differences between the stresses to which either is subjected. In the course of evolution there has certainly been an obvious conflict in aims between the need for essential stability and the desired or necessary mobility. These mutually self-limiting mechanisms are reflected in the highly specialized architecture of the ligamentous apparatus and vertebral joints. We conclude that the human vertebral column seems to be an optimized compromise of evolution. © 1996 Wiley-Liss, Inc. 相似文献