45 research outputs found

    A comparison of the performance of 68Ga-Pentixafor PET/CT versus adrenal vein sampling for subtype diagnosis in primary aldosteronism

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    ObjectiveTo investigate the diagnostic efficiency and prognostic value of 68Ga-Pentixafor PET/CT in comparison with adrenal vein sampling (AVS) for functional lateralization in primary aldosteronism (PA). Histology and long-term clinical follow-up normally serve as the gold standard for such diagnosis.MethodsWe prospectively recruited 26 patients diagnosed with PA. All patients underwent 68Ga-Pentixafor PET/CT and AVS. Postsurgical biochemical and clinical outcomes of patients with unilateral primary aldosteronism (UPA), as diagnosed by PET/CT or AVS, were assessed by applying standardized Primary Aldosteronism Surgical Outcome (PASO) criteria. Immunohistochemistry (IHC) was performed to detect the expression of aldosterone synthase (CYP11B2) and CXCR4.ResultsOn total, 19 patients were diagnosed with UPA; of these, 13 patients were lateralized by both PET/CT and AVS, four patients were lateralized by PET-only, and two by AVS-only. Seven subjects with no lateralization on AVS and PET received medical therapy. All patients achieved complete biochemical success except one with nodular hyperplasia lateralized by AVS alone. The consistency between PET/CT and AVS outcomes was 77% (20/26). Moreover, CYP11B2-positive nodules were all CXCR4-positive and showed positive findings on PET. Patients who achieved complete biochemical and clinical success had a higher uptake on PET as well as stronger expression levels of CXCR4 and CYP11B2.ConclusionOur analysis showed that 68Ga-Pentixafor PET/CT could enable non-invasive diagnosis in most patients with PA and identify additional cases of unilateral and surgically curable PA which could not be classified by AVS. 68Ga-Pentixafor PET/CT should be considered as a first-line test for the future classification of PA

    Dissociable Modulation of Overt Visual Attention in Valence and Arousal Revealed by Topology of Scan Path

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    Emotional stimuli have evolutionary significance for the survival of organisms; therefore, they are attention-grabbing and are processed preferentially. The neural underpinnings of two principle emotional dimensions in affective space, valence (degree of pleasantness) and arousal (intensity of evoked emotion), have been shown to be dissociable in the olfactory, gustatory and memory systems. However, the separable roles of valence and arousal in scene perception are poorly understood. In this study, we asked how these two emotional dimensions modulate overt visual attention. Twenty-two healthy volunteers freely viewed images from the International Affective Picture System (IAPS) that were graded for affective levels of valence and arousal (high, medium, and low). Subjects' heads were immobilized and eye movements were recorded by camera to track overt shifts of visual attention. Algebraic graph-based approaches were introduced to model scan paths as weighted undirected path graphs, generating global topology metrics that characterize the algebraic connectivity of scan paths. Our data suggest that human subjects show different scanning patterns to stimuli with different affective ratings. Valence salient stimuli (with neutral arousal) elicited faster and larger shifts of attention, while arousal salient stimuli (with neutral valence) elicited local scanning, dense attention allocation and deep processing. Furthermore, our model revealed that the modulatory effect of valence was linearly related to the valence level, whereas the relation between the modulatory effect and the level of arousal was nonlinear. Hence, visual attention seems to be modulated by mechanisms that are separate for valence and arousal

    Pharmacokinetic study and metabolite identification of the bidesmosidic triterpenoid saponin BTS-1 in rat plasma

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    Assays based on high-performance liquid chromatography (HPLC) and liquid chromatography tandem mass spectrometry (LC–MSn) have been developed and validated for the determination and metabolite identification of the bidesmosidic triterpenoid saponin, BTS-1 (3-O-β-d-galactopyranosyl-(1→2)-[β-d-xylopyranosyl-(1→3)]-β-d-glucuronopyranosyl gypsogenin 28-O-α-l-arabinopyranosyl-(1→3)-β-d-xylopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→2)-β-d-fucopyranoside), in rat plasma. The assay was successfully applied to a pharmacokinetic study in rats given a single oral dose of BTS-1 (400 mg/kg). The results indicated that the compound was rapidly absorbed (Tmax=1.28±0.29 h, Cmax=37.4±5.6 µg/mL) and slowly eliminated (t1/2=13.2±6.6 h). In addition, secondary glycosides and aglycones of BTS-1 were detected and identified. Since these metabolites are known to be active α-glucosidase inhibitors, they probably play an important role in mediating the pharmacological effects of the saponin

    Downregulation of Aquaporin 3 Mediated the Laxative Effect in the Rat Colon by a Purified Resin Glycoside Fraction from Pharbitis Semen

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    Background. Pharbitis Semen, the seeds of Pharbitis nil, is widely used as a traditional purgative medicine in China, Korea, and Japan. This study investigated the laxative effects of a purified resin glycoside fraction obtained in our previous study from Pharbitis Semen in vivo and in vitro. Materials and Methods. After orally administering a purified resin glycoside fraction from Pharbitis Semen (RFP) to rats, the content of fecal water, AQP3, NF-κB, COX-2 expression, and the prostaglandin E2 (PGE2) concentrations in the colon were examined. Moreover, human intestinal epithelial cells (HT-29) were used to investigate the mechanism of RFP decreasing the AQP3 expression. Results. Results obtained showed that treatment with RFP increased the feces excretion and fecal water content of rats in a dose-dependent manner. More interestingly, AQP3 expression was suppressed by RFP treatment both in the rat colons and in HT-29 cells, while the NF-κB pathway-mediated PGE2 production was activated. Interestingly, pretreating rats with BAY-11-7082 (NF-κB inhibitor) or indomethacin (COX-2 inhibitor) and RFP neither induced diarrhea nor decreased the AQP3 expression in the colon. Conclusions. The purgative property of the purified resin glycoside fraction was attributed to NF-κB activation in the colon, which increased the COX-2-mediated secretion of PGE2. PGE2 decreased AQP3 expression which inhibits water absorbed from the intestine to the blood vessel side, resulting in the laxative effect of RFP

    A new neo

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    Investigation into the Gaseous SO<sub>2</sub> Attack on Sandstone in the Yungang Grottoes

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    The Yungang Grottoes, with over 1500 years of history, have been subjected to air pollution since the last century. Field investigations have indicated that acid gases, particularly sulfur dioxide (SO2), have accumulated on the surface of the sculptures and caused various types of decay that reduce their artistic value. To shed new light on the gas–stone interaction process, artificially accelerated weathering was performed on local sandstone in the laboratory. In a specially developed test device, fresh specimens were exposed to gaseous SO2 under different relative humidity and temperature conditions. The physical, mineralogical, and chemical changes of Yungang sandstone were evaluated conjointly using destructive and non-destructive methods. The results show that after weathering, the luminosity of all specimens changed, with a slight alteration in hue toward yellow. The weight increased to various degrees during the aging cycles, which depended on both the accumulation of matter and the detachment of particles. Higher relative humidity and cyclic temperature fluctuations favored the dissolution of carbonates and the hydrolysis of feldspar in sandstone. The concentration of ions, especially dissolved Ca2+ and SO42−, increased considerably over time in the near-surface region of the specimens. A trace of newly formed gypsum was detected in some specimens at the end of the test. Knowing the synergistic impact of different climatic variables will make it possible to identify the mechanisms of the deterioration of sandstone in complex environments

    A new alkaloid glycoside from the rhizomes of <i>Aristolochia fordiana</i>

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    <div><p>A new alkaloid glycoside named fordianoside (<b>1</b>), together with three known compounds arabinothalictoside (<b>2</b>), 6-<i>O</i>-<i>p</i>-coumaroyl-β-fructofuranosyl-(2 → 1)-α-d-glucopyranoside (<b>3</b>) and 4-[formyl-5-(hydroxymethyl)-1<i>H</i>-pyrrol-1-yl] butanoic acid (<b>4</b>), was isolated from the rhizomes of <i>Aristolochia fordiana</i>. The structure of <b>1</b> was established as (1<i>S</i>)-1,2,3,4-tetrahydro-7-hydroxy-1-[(4-hydroxybenzyl) methyl]-2,2-dimethyl-8-<i>O</i>-isoquinolinyl β-d-glucopyranoside by using chemical and spectroscopic methods including HR-ESI-MS, 1D and 2D NMR.</p></div
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