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101.
Nevin McVicar Alex X Li Daniela F Gon?alves Miranda Bellyou Susan O Meakin Marco AM Prado Robert Bartha 《Journal of cerebral blood flow and metabolism》2014,34(4):690-698
Tissue pH is an indicator of altered cellular metabolism in diseases including stroke and cancer. Ischemic tissue often becomes acidic due to increased anaerobic respiration leading to irreversible cellular damage. Chemical exchange saturation transfer (CEST) effects can be used to generate pH-weighted magnetic resonance imaging (MRI) contrast, which has been used to delineate the ischemic penumbra after ischemic stroke. In the current study, a novel MRI ratiometric technique is presented to measure absolute pH using the ratio of CEST-mediated contrast from amine and amide protons: amine/amide concentration-independent detection (AACID). Effects of CEST were observed at 2.75 parts per million (p.p.m.) for amine protons and at 3.50 p.p.m. for amide protons downfield (i.e., higher frequency) from bulk water. Using numerical simulations and in vitro MRI experiments, we showed that pH measured using AACID was independent of tissue relaxation time constants, macromolecular magnetization transfer effects, protein concentration, and temperature within the physiologic range. After in vivo pH calibration using phosphorus (31P) magnetic resonance spectroscopy (31P-MRS), local acidosis is detected in mouse brain after focal permanent middle cerebral artery occlusion. In summary, our results suggest that AACID represents a noninvasive method to directly measure the spatial distribution of absolute pH in vivo using CEST MRI. 相似文献
102.
Axel Andres Tatsuya Kin Doug O'Gorman David Bigam Norman Kneteman Peter Senior AM James Shapiro 《Transplant international》2014,27(11):1135-1142
The consequence of a pancreas injury during the procurement for islet isolation purpose is unknown. The goal of this work was to assess the injuries of the pancreata procured for islet isolation, and to determine their effect on the islet yield. Between January 2007 and October 2013, we prospectively documented every injury of the pancreata processed in our centre for islet isolation. Injuries involving the main duct were classified as major, the others as minor. Donors’ characteristics and islet yields were compared between the groups of injuries. A pancreas injury was identified in 42 of 452 pancreata received for islet isolation (9.3%). In 15 cases, the injury was major (3.3% of all pancreata). Although a minor injury did not affect the islet yield, a major injury was significantly associated with unfavourable outcomes (postpurification mean islet equivalent of 364 ± 181, 405 ± 190 and 230 ± 115 × 103 for absence of injury, minor injury and major injury, respectively). A major injury was significantly more prevalent in lean and short donors. We recommend assessing the quality of the pancreas in the islet isolation centre before starting the isolation procedure. Each centre should determine its own policy based on its financial resources and on the wait list. 相似文献
103.
SmartJ Mpofu Titus AM Msagati Rui W M Krause 《African journal of traditional, complementary, and alternative medicines》2014,11(1):34-52
Background
Elephantorrhiza elephantina (Ee) and Pentanisia prunelloides (Pp) are two medicinal plants which are widely used to remedy various ailments including diarrhoea, dysentery, inflammation, fever, rheumatism, heartburn, tuberculosis, haemorrhoids, skin diseases, perforated peptic ulcers and sore joints in southern Africa (South Africa, Swaziland, Botswana and Zimbabwe). The following study was conducted to explore the in vitro cytotoxicity, antioxidant properties and phytochemical profile of the two medicinal plants.Materials and Methods
The cytotoxicity of the aqueous and methanol extracts and fractions of both species was studied using the brine shrimp lethality tests (BST) for the first time.Results
The results demonstrated that the lethality (LC50) for crude extracts for both plants ranged between 1.8 and 5.8 ppm and was relatively greater than that for the methanol, ethyl acetate and chloroform fractions of the extracts which ranged between 2.1 ppm and 27 ppm. This suggested that crude extracts were more potent than their respective fractions, further explaining that the different fractions of phytochemicals in these plant species work jointly (in synergy) to exert their therapeutic efficacy. Both aqueous and methanol extracts of the two medicinal plants demonstrated a high degree of antioxidant capacity against the DPPH radical with the Duh and Yen inhibition percentage ranging between 4.5% and 72%. Phytochemical studies of the rhizome extracts showed that the major compounds present include flavonoids, tannins, anthocyanidins, anthraquinones, triterpenoids (oleanolic acid), the steroidal saponin Diosgenin, the sugars, rhamnose, glucuronic acid, Arabinose and hexoses.Conclusion
This is the first report of the detection and isolation of diosgenin and oleanolic acid from the rhizome extracts of Ee and Pp. All structures were determined using spectroscopic/spectrometric techniques (1H NMR and 13C and LC-ESI-MS) and by comparison with literature data. 相似文献104.
105.
应用序列特异引物PCR法对广西壮族HLA-DQA_1进行基因分型 总被引:1,自引:0,他引:1
应用序列特异引物多聚酶链反应(PCR)方法对82名无血缘关系的广西壮族健康人的HLA-DQA_1进行基因分型。共检出7种DQA_1等位基因,以DQA_1*0301的频率最高,达31%,其次为DQA_1*0104,0102和0501,检出率分别为24.3%,16.9%和11.7%。未检出的等位基因有DQA_1*0201,0302和0601。结果表明,壮族的HLA-DQA_1等位基因频率分布除与中国南方人相似外,尚有其特点。序列特异引物PCR方法不需要放射性同位素,简便快速、准确可靠的HLA-DQA_1基因分型新方法。 相似文献
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107.
Reza Fekrazad Khojasteh Joharchi Katayoun AM Kalhori Fatemeh Mashhadi Abbas Fariborz Salimi Vahid 《Journal of cosmetic and laser therapy》2017,19(4):232-236
Introduction: One of the most important innovative methods for tissue repair promotion is therapeutic lasers with photobiomodulution effects. The aim of this study was to investigate the effect of four different wavelengths of therapeutic laser (405, 532, 660 and 810 nm) on healing of third-degree burns from both clinical and pathological standpoints in rats. Materials and methods: 60 male Wistar rats were used. Animals were anesthetized and dorsal hairs were shaved and third-degree skin burns were created by use of a 95°C copper stamp. Lesions were irradiated with 1.5 J/cm2 energy densities and 200 mW/cm2 power densities. Results: Statistical analyses of the “wound contraction” changes between five groups during the study showed more reduction in wound size in all laser groups in comparison with the control group; but these differences were not statistically significant except between red and blue lasers on the last day of experiment. Discussion: Results of our study showed that using therapeutic lasers with green, blue, red, and infrared wavelengths may accelerate healing process. This trend is more obvious in red and infrared groups especially after acute phase, however, this effect was neither statistically nor clinically significant. 相似文献
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