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991.
The aim of this study was to investigate the ultrastructural appearance of pancreatic adenocarcinoma combined with glucagon and gastrin/cholecystokinin (CCK) expression. The authors investigated the ultrastructure and the immunocytochemistry of 12 human pancreatic cancer specimens and used 3 chronic pancreatitis samples and 6 adjacent histological normal pancreatic tissues (away from the tumor) as controls. The ultrastructural study revealed that chronic pancreatitis tissues were characterized by alterations of the secretory cells. The enzymic and secretory changes were confirmed by electron immunogold results. Glucagon appeared to be located not only in islet α cells but also in intermediate α acinar cells. The changes were more significant in adenocarcinoma cases. Abnormality in the immunoreaction of the peptides was indicated not only in the tumor area but also in the islets near the cancer. Cells immunoreactive with antibodies were found in all 12 adenocarcinoma cases. Abnormal co-location of both hormones in the same type of endocrine cell was also found. Moderately to poorly differentiated adenocarcinomas were poorly granulated compared with differentiated tumors. Increased and ectopic gastrin/CCK expression was correlated with pancreatic adenocarcinomas exhibiting poor histological grade and neoplastic endocrine cells, providing a potential marker for pancreatic adenocarcinomas with aggressive behavior. 相似文献
992.
Dilek Akakin Demir Kiran Naziye Ozkan Mehmet Erşahin Zarife Nigar Ozdemir-Kumral Berrak Yeğen Göksel Şener 《Acta histochemica》2013
Spinal cord injury (SCI) induced oxidative stress affects multiple organ systems including the kidney. We studied the possible protective effects of melatonin on SCI-induced oxidative damage in renal tissues of rats. Wistar albino rats (n = 24) were exposed to SCI and divided into vehicle- or melatonin-treated SCI groups. Melatonin was administred intraperitoneally at a dose of 10 mg/kg for seven days. Renal tissues were investigated by light and electron microscopy. Furthermore, tissue malondialdehyde (MDA) and glutathione (GSH) levels and myeloperoxidase (MPO) and superoxide dismutase (SOD) activities were also determined. In the vehicle-treated SCI group, the renal histology was disturbed compared to controls, whereas the melatonin-treated SCI group showed significantly reduced degeneration of renal tissue as seen by both light and electron microscopy. MDA levels, MPO and SOD activities were increased and GSH levels were decreased in the vehicle-treated SCI group compared to controls. On the other hand, decreased MDA levels and MPO activities and increased GSH levels were observed in the melatonin-treated SCI group compared to vehicle-treated SCI group. These results showed that experimentally induced SCI caused oxidative stress in the rat kidney, whereas melatonin treatment reduced oxidative stress, suggesting that it may be used as a complementary therapy of renal problems occurring following SCI. 相似文献
993.
none 《Journal of histotechnology》2013,36(2):125-127
AbstractThis paper describes a rapid protocol for iliac crest biopsies with embedding in LR White plastic to facilitate diagnosis of osteomalacia. Sections were cut and stained for light and electron microscopy using traditional staining methods with minor modifications. Total processing time was within three days. (The J Histotechnol 13:125, 1990) 相似文献
994.
《Journal of histotechnology》2013,36(2):133-135
AbstractA joint survey by the National Society for Histotechnology and the American Society of Clinical Pathologists (ASCP) revealed that employment prospects were good in all regions of the country. Most responding laboratories reported at least one ASCP certified histotechnician, and more than 19% employed at least one ASCP certified histotechnologist. Work experience was considered important for histotechnicians; education for histotechnologists. Salary levels were generally correlated with responsibilities and certification. (The Journal of Histotechnology 10: 133, 1987.) 相似文献
995.
《Journal of biomaterials science. Polymer edition》2013,24(7):609-620
Atomic force microscopy is used to image the topography of surfaces of bulk medical-grade ultrahigh molecular weight polyethylene (UHMWPE). Comparison with transmission electron microscopy images demonstrates that the AFM can resolve the plate-like stacks of crystalline lamellae characteristic of UHMWPE without aggressive surface treatment. Surface preparation for the AFM must be carried out by cryomicrotomy at extremely low temperatures to prevent smearing of surface features. Chemically-etched surfaces of UHMWPE require substantially less surface preparation for AFM imaging. 相似文献
996.
Fatemeh Safara Shyamala Doraisamy Azreen Azman Azrul Jantan Asri Ranga Abdullah Ramaiah 《Computers in biology and medicine》2013
Wavelet packet transform decomposes a signal into a set of orthonormal bases (nodes) and provides opportunities to select an appropriate set of these bases for feature extraction. In this paper, multi-level basis selection (MLBS) is proposed to preserve the most informative bases of a wavelet packet decomposition tree through removing less informative bases by applying three exclusion criteria: frequency range, noise frequency, and energy threshold. MLBS achieved an accuracy of 97.56% for classifying normal heart sound, aortic stenosis, mitral regurgitation, and aortic regurgitation. MLBS is a promising basis selection to be suggested for signals with a small range of frequencies. 相似文献
997.
ObjectivesThe aim of this paper is to illustrate the current status of imaging in high breast density as we enter a new decade of advancing medicine and technology to diagnose breast lesions.Key findingsEarly detection of breast cancer has become the chief focus of research from governments to individuals. However, with varying breast densities across the globe, the explosion of breast density information related to imaging, phenotypes, diet, computer aided diagnosis and artificial intelligence has witnessed a dramatic shift in new screening recommendations in mammography, physical examination, screening younger women and women with comorbid conditions, screening women at high risk, and new screening technologies. Breast density is well known to be a risk factor in patients with suspected/known breast neoplasia. Extensive research in the field of qualitative and quantitative analysis on different tissue characteristics of the breast has rapidly become the chief focus of breast imaging. A summary of the available guidelines and modalities of breast imaging, as well as new emerging techniques under study that can potentially provide an augmentation or even a replacement of those currently available.ConclusionDespite all the advances in technology and all the research directed towards breast cancer, detection of breast cancer in dense breasts remains a dilemma.Implications for practiceIt is of utmost importance to develop highly sensitive screening modalities for early detection of breast cancer. 相似文献
998.
Differentiation along a distinct cell lineage can be identified either morphologically or with the adjunct of different ancillary techniques. While immunohistochemistry has progressively supplanted electron microscopy as the method of choice to characterize the phenotype of neoplastic cells in soft tissue tumors and in solving most differential diagnoses, a number of lesions still lack reliable specific markers or show overlapping antigen expression, which can be categorized by ultrastructural analysis through the recognition of submicroscopic features indicative of a specific line of differentiation. This review discusses the role of electron microscopy in the identification of the phenotype of neoplastic cells in soft tissue sarcomas, with particular reference to the diagnostic aspects. Sarcomas in which the cellular phenotype that can be better recognized by electron microscopy include those belonging to the fibroblastic/myofibroblastic group, particularly those displaying a poorly differentiated/pleomorphic morphology. Occasionally, in tumors with smooth muscle, skeletal muscle, adipocytic, vascular endothelial, and Schwann cell differentiation electron microscopy may help in the differential diagnosis. 相似文献
999.
Inflammatory bowel disease (IBD) is commonly believed to increase the risk of bone mineral loss, leading to osteoporosis and an increased risk of disabling fractures. In this narrative review, we will presenting a summary of the published medical literature in regards to the relationship between IBD and the development of osteoporosis, bone mineral loss, and fractures. We will explore the epidemiology of metabolic bone disease in IBD, focusing on the prevalence and both the general and IBD-specific risk factors for the development of osteoporosis and of fracture in persons with IBD. We will also examine the role of the inflammatory process in IBD promoting excessive bone mineral loss, as well as the role that low body mass, corticosteroid use, diet, and nutrient malabsorption play in contributing to bone disease. Last, we will discuss our recommendation for: screening for osteoporosis in IBD patients, the use of preventative strategies, and therapeutic interventions for treating osteoporosis in persons with IBD. 相似文献
1000.
《Journal of medical engineering & technology》2013,37(6-7):344-353
During the recording time of lung sound (LS) signals from the chest wall of a subject, there is always heart sound (HS) signal interfering with it. This obscures the features of lung sound signals and creates confusion on pathological states, if any, of the lungs. A novel method based on empirical mode decomposition (EMD) technique is proposed in this paper for reducing the undesired heart sound interference from the desired lung sound signals. In this, the mixed signal is split into several components. Some of these components contain larger proportions of interfering signals like heart sound, environmental noise etc. and are filtered out. Experiments have been conducted on simulated and real-time recorded mixed signals of heart sound and lung sound. The proposed method is found to be superior in terms of time domain, frequency domain, and time–frequency domain representations and also in listening test performed by pulmonologist. 相似文献