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81.
82.
ObjectivesDesign and build a portable xenon-129 (129Xe) hyperpolariser for clinically accessible 129Xe lung MRI.MethodsThe polariser system consists of six main functional components: (i) a laser diode array and optics; (ii) a B0 coil assembly; (iii) an oven containing an optical cell; (iv) NMR and optical spectrometers; (v) a gas-handling manifold; and (vi) a cryostat within a permanent magnet. All components run without external utilities such as compressed air or three-phase electricity, and require just three mains sockets for operation. The system can be manually transported in a lightweight van and rapidly installed on a small estates footprint in a hospital setting.ResultsThe polariser routinely provides polarised 129Xe for routine clinical lung MRI. To test the concept of portability and rapid deployment, it was transported 200 km, installed at a hospital with no previous experience with the technology and 129Xe MR images of a diagnostic quality were acquired the day after system transport and installation.ConclusionThis portable 129Xe hyperpolariser system could form the basis of a cost-effective platform for wider clinical dissemination and multicentre evaluation of 129Xe lung MR imaging.Advances in knowledgeOur work successfully demonstrates the feasibility of multicentre clinical 129Xe MRI with a portable hyperpolariser system.  相似文献   
83.
Rats were treated chronically with primidone (100 mg/kg/12 hr, p.o.) for up to 8 weeks. The effects of this treatment on one-carbon metabolism were determined in brain and liver. Serine hydroxymethyltransferase activity increased in both brain (44%) and liver (50%). Methylenetetrahydrofolate reductase activity increased in liver (26%) with a significant correlation to the length of treatment, but in brain it was unchanged. Methyltetrahydrofolate:homocysteine methyltransferase activity increased in brain (43%) with a significant correlation to length of treatment, but in liver no effect was observed. Methionine adenosyltransferase activity in brain was significantly lower than control at only one point after 8 weeks of chronic treatment. S-Adenosylmethionine concentration in liver increased gradually (23%) during treatment. S-Adenosylhomocysteine concentrations decreased in brain (33%) and increased in liver (23%) with chronic primidone treatment. These data support the hypothesis that chronic primidone treatment leads to folate depletion through interference with folate metabolism.  相似文献   
84.
One hundred informants including full time/part time herbalists, old ladies, family heads and village heads were interviewed for the type of plants used in their homes for the treatment of some common diseases. Forty eight plant species were found to be used by Ondo people in folk medicine. Fourteen species were found to contain alkaloids and 34 plant species were found to have local actions. The plant parts used, their uses and biodynamic notes are given.  相似文献   
85.
BackgroundThe rapid urease test (RUT) is a major diagnostic tool for detecting Helicobacter pylori infection. This study aimed to establish an objective method for measuring the color changes in the RUT kit to improve the test’s diagnostic accuracy.MethodsA UV-visible spectrophotometer was selected as the colorimeter; experiments were conducted in three stages to objectively identify the color changes in the RUT kit.ResultsFirst, the urea broth solution showed an identifiable color change from yellow to red as the pH increased by 0.2. The largest transmittance difference detected using the UV-visible spectrophotometer was observed at a 590-nm wavelength. Second, the commercialized RUT kit also showed a gradual color change according to the pH change detected using the UV-visible spectrophotometer. Third, 13 cases of negative RUT results with a biopsy specimen and 16 of positive RUT results were collected. The transmittance detected using the UV-visible spectrophotometer showed a clear division between the positive and negative RUT groups; the largest difference was observed at a 559-nm wavelength. The lowest transmittance in the negative RUT group was 64, while the highest in the positive RUT group was 56, at the 559-nm wavelength. The UV-visible spectrophotometry reading showed a consistency of 92.7% compared with that of manual reading.ConclusionA transmittance of 60 at a 559-nm wavelength detected using UV-visible spectrophotometer can be used as a cutoff value for interpreting RUT results; this will help develop an automatic RUT kit reader with a high accuracy.  相似文献   
86.
An Australian estuarine isolate of an Acremonium sp. (MST-MF588a) yielded the two known compounds 19- O-acetylchaetoglobosin D ( 1) and 19- O-acetylchaetoglobosin B ( 2), as the sole cytotoxic principles, along with the known aromatic metabolite RKB 3564S ( 3), and a novel family of lipodepsipeptides, acremolides A-D ( 4- 7). Structures were assigned to 4- 7 on the basis of detailed spectroscopic analysis and chemical derivatization and by application of a new C 3 Marfey's method for amino acid analysis.  相似文献   
87.
Sodium pancratistatin 3,4- O-cyclic phosphate ( 2) is a novel water-soluble synthetic derivative of pancratistatin ( 1), a natural alkaloid constituent of Amaryllidaceae plants, that exhibits good cytostatic and antineoplastic activity but is highly insoluble. Unlike most other natural alkaloids it does not act by binding to tubulin, and its mechanism of action has yet to be fully elucidated. Here the efficacy of 2 in a human colon adenocarcinoma model, DLD-1, and some understanding of its mode of action are investigated. Agreeing with previous studies, low cytotoxicity in vitro was seen for 2 with IC 50's of 253 and 19.7 microM for 1 and 96 h exposures, respectively. However in vivo the compound caused statistically significant tumor growth delays ( p < 0.01) at its maximum tolerated dose, and significant vascular shutdown and tumor necrosis were observed. Like 1, the compound appeared to have an unconventional mechanism of action with no effect on microtubule structure, yet causing a G 2/M block, while it was seen to disrupt mitochondrial function. The mechanism of action of 1 and 2 appears to be similar. Thus compound 2, being considerably more soluble than 1, has good potential as an anticancer agent, and further investigation is warranted.  相似文献   
88.
The present study was designed to investigate whether the aqueous extract of rhubarb (AR) could prevent the development of atherosclerosis through regulating vascular inflammatory processes in rats fed with an atherogenic diet. AR significantly reduced plasma low-density lipoprotein-cholesterol, and increased plasma high-density lipoprotein-cholesterol in rats fed with an atherogenic diet. AR inhibited vascular expressions of endothelin-1 (ET-1) and endothelin-converting enzyme (ECE) induced in rats with an atherogenic diet. On the other hand, AR augmented the vascular expression of endothelial nitric oxide synthase (ecNOS) and restored vascular nitric oxide (NO) production. Furthermore, AR suppressed the elevated expression of vascular nuclear factor-kappaB (NF-kappaB) p65 as well as adhesion molecules, including intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin in rats fed with an atherogenic diet. Also, AR decreased endothelial expression of ICAM-1 and ET-1 in aorta. These results suggest that AR suppresses the development of atherosclerosis in the atherogenic-diet rat model through inhibiting vascular expressions of proinflammatory and adhesion molecules via the regulation of nitric oxide and endothelin system.  相似文献   
89.
90.
In a cross-sectional study of aggression, and adaptive and maladaptive behaviour in 128 subjects with Down's syndrome (DS), 29 of whom had dementia, the current authors found that the presence of dementia was not predictive of aggression or maladaptive behaviour. However, the level of adaptive behaviour was shown to be lower in subjects with dementia, and in those with lower levels of cognitive functioning, as measured on a rating instrument, the Test for Severe Impairment. Although the presence of aggressive behaviours is not higher in subjects with dementia and DS on cross-sectional review, it remains to be seen whether aggression will increase in individual cases with the onset or progression of dementia. The decline in adaptive behaviour shown in the present study confirms the findings of previous studies and indicates a direction for service development for persons with the dual diagnosis of dementia and DS.  相似文献   
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