Application of one-step inner-recycling counter-current chromatography for the preparative separation and purification of chemical constituents from the rhizome of Bergenia ciliate (haw.) Sternb.

Bergenia ciliata (haw.) Sternb, the renowned pharmaceutical plant in Jammu and Kashmir of Pakistan, is widely applied in treating different illnesses including diabetes, diarrhea, and vomiting. This work employed an efficient one-step inner-recycling counter-current chromatography for preparative separating and purifying compounds with similar partition coefficients from the rhizome of Bergenia ciliate (haw.). Five compounds, including quercetin rhamnodiglucoside (1), quercetin-3-O-rutinoside (2), bergenine (3), kaempferol (4), and palmatic acid (5), were successfully separated using the optimized biphasic solvent system that contained ter-butylmetylether/n-butanol/acetonitrile/water (2:2:1:5, v/v) with the purities over 98%. Mass spectrometry and nuclear magnetic resonance were conducted for structural identification. As a result, our proposed strategy might be applied in separating compounds with similar partition coefficients, which was advantageous with regard to the less solvent and time consumption, and the increased number of theoretical plates.

Isolation and purification of high polar glycosides from aerial parts of Gynostemma pentaphyllum (Thunb.) Makino by linear gradient counter-current chromatography coupled with inner-recycling mode.

Gynostemma pentaphyllum (Thunb.) Makino represents the popular health food and supplemental product with broad pharmacological activities. The highly polar glycosides, including flavonoids and saponins, are major effective active components that contain diverse sugar positions and quantities, which result in diverse chemical polarities, making it challenging to separate and isolate these components. The present work described the rapid and efficient linear gradient counter-current chromatography to preparatively separate glycosides from aboveground parts of G. pentaphyllum. Besides, the ethyl acetate and n-butanol binary mobile phases were achieved through adjusting associated proportions. Six glycosides, including quercetin-3-O-neohesperidoside (1), kaempferol-3-O-robinobioside (2), kaempferol-3-O-neohesperidoside (3), gypenoside LVI (4), ginsenoside Rb3 (5), and gypenoside XLVI (6), were isolated at the purities greater than 98%. Moreover, electrospray ionization mass spectrometry and nuclear magnetic resonance tandem mass spectrometry were conducted for structural identification. According to our findings, the established linear gradient counter-current chromatography was an efficient approach to separate the highly polar glycosides from aboveground parts of G. pentaphyllum. Our proposed strategy can be used to separate active compounds from other complex natural products.

Separation and purification of quinolyridine alkaloids from seeds of Thermopsis lanceolata R. Br. by conventional and pH-zone-refining counter-current chromatography.

In this work, the preparative separation of quinolyridine alkaloids from seeds of T. lanceolata by conventional and pH-zone-refining counter-current chromatography. Traditional counter-current chromatography separation was performed by a flow-rate changing strategy with a solvent system of ethyl acetate-n-butanol-water (1:9:10, v/v) and 200 mg sample loading. Meanwhile, the pH-zone-refining mode was adopted for separating 2.0 g crude alkaloid extracts with the chloroform-methanol-water (4:3:3, v/v) solvent system using the stationary and mobile phases of 40 mM hydrochloric acid and 10 mM triethylamine. Finally, six compounds, including N-formylcytisine (two conformers) (1), N-acetycytisine (two conformers) (2), (-)-cytisine (3), 13-ß-hydroxylthermopsine (4), N-methylcytisine (5), and thermopsine (6) were successfully obtained in the two counter-current chromatography modes with the purities over 96.5%. Moreover, we adopted nuclear magnetic resonance and mass spectrometry for structural characterization. Based on the obtained findings, the pH-zone-refining mode was the efficient method to separate quinolyridine alkaloids relative to the traditional mode.

Impact of serum albumin level and variability on short-term cardiovascular-related and all-cause mortality in patients on maintenance hemodialysis.

ABSTRACT: Studies have shown that low serum albumin (Salb) levels are associated with a high risk of mortality among patients on maintenance hemodialysis (MHD); however, the impact of Salb variability on short-term cardiovascular mortality remains unclear. Herein, we investigated the association between Salb levels and Salb variability on short-term all-cause and cardiovascular-related mortality in patients on MHD.Eligible patients on MHD at Chongqing General Hospital between June 2017 and June 2020 were recruited in this study. Patients were grouped by Salb levels (normal Salb, ≥3.8 g/dL; low Salb, 3.4-3.8 g/dL; and lower Salb, 2-3.4 g/dL) and Salb variability (decreased, >5% loss; increased, >5% gain; and steady, 5% loss to 5% gain). Associations between Salb levels, Salb variability, and all-cause and cardiovascular-related mortality were analyzed using Cox regression models. A survival analysis was performed using the Kaplan-Meier analysis.We enrolled a total of 181 patients on MHD with an average age of 65 years (interquartile range [IQR], 53-75 years). The mean Salb level was 3.8 ±â€Š0.6 g/dL (IQR 2.9-4.4 g/dL), and the median Salb variability was 2.6% per year (IQR, -4.1 to 6.5). Fifty-two (29%) patients died, including 31 (17%) patients who died due to cardiovascular-related causes. Compared with the other groups, the lower Salb group had higher all-cause mortality (P < .01). Cox regression analyses revealed that lower Salb levels and decreased Salb variability were independently associated with all-cause mortality (hazard ratio [HR] = 1.95, 95% confidence interval [CI] 1.103-3.452; HR = 2.245, 95% CI 1.084-4.650), whereas increased Salb variability was independently associated with cardiovascular-related mortality (HR = 2.919, 95% CI 1.178-7.234; P < .05).Lower Salb levels were an independent predictor of all-cause mortality in patients on MHD. Increased Salb variability was strongly associated with cardiovascular-related mortality in the same population, especially in the short-term and in patients with normal Salb levels. Significantly elevated Salb variability should be evaluated to reduce cardiovascular-related mortality.

Technical Note: Performance evaluation of a small-animal PET/CT system based on NEMA NU 4-2008 standards.

PURPOSE: The MetisTM PET/CT is a self-developed, silicon photomultiplier (SiPM) detector-based, rodent PET/CT system. The objective of this study was to evaluate the performance of the system using the National Electrical Manufacturers Association (NEMA) NU 4-2008 standard protocol. METHODS: Energy resolution, spatial resolution, sensitivity, scatter fraction (SF), noise-equivalent count rate (NECR), and image quality (IQ) characteristics were measured. A micro Derenzo phantom experiment was performed to evaluate the spatial resolution using three-dimensional ordered-subsets expectation maximization (3D-OSEM) and maximum likelihood expectation maximization (MLEM) reconstructed images. In addition, the CT imaging agent Ioverol 350 was mixed with fluorine-18 (18 F)-fluorodeoxyglucose (FDG) and then injected into the micro Derenzo phantom to evaluate the PET/CT imaging. In vivo PET/CT imaging studies were also conducted in a healthy mouse and rat using 18 F-FDG. RESULTS: The mean energy resolution of the system was 15.3%. The tangential resolution was 0.82 mm full-width half-maximum (FWHM) at the center of the field of the view (FOV), and the radial and axial resolution were generally lower than 2.0 mm FWHM. The spatial resolution was significantly improved when using 3D-OSEM, especially the axial FWHM could be improved by up to about 57%. The system absolute sensitivity was 7.7% and 6.8% for an energy window of 200-750 and 350-750 keV respectively. The scatter fraction was 8.2% and 12.1% for the mouse- and rat-like phantom respectively. The peak NECR was 1343.72 kcps at 69 MBq and 640.32 kcps at 53 MBq for the mouse- and rat-like phantom respectively. The 1-mm fillable rod in the IQ phantom can be clearly observed. We can identify the 0.6-mm aperture of the micro Derenzo phantom image clearly using 3D-OSEM (10 subsets, 5 iterations). We also performed the fusion of the PET and CT images of the mouse and the brain imaging of the rat. CONCLUSIONS: The results show that the system has the characteristics of high-resolution, high-sensitivity, and excellent IQ and is suitable for rodent imaging-based research.

Fangchinoline Protects Against Renal Injury in Diabetic Nephropathy by Modulating the MAPK Signaling Pathway.

In this study, we evaluated the nephroprotective effects of fangchinoline in rats with diabetic nephropathy (DN). DN was induced by feeding a high-fat diet for 4 weeks and administering a single dose of streptozotocin (STZ) (30 mg/kg) intraperitoneally. The rats were split into groups; one group received oral fangchinoline (3 mg/kg) per day for 8 weeks. After completion of the 8-week study period, biomedical and inflammatory markers were evaluated in serum and urine, and oxidative stress was estimated in kidney tissues. In addition, Western blot assays, reverse transcription-polymerase chain reaction, and immunohistochemical analyses were performed in the kidney tissues of DN rats. The results suggest that treatment with fangchinoline attenuated the biochemical marker changes induced by DN in blood and urine. Moreover, a significant (p<0.01) reduction in inflammatory markers in serum was found in the fangchinoline group compared to the controls. Immunohistochemical analyses also revealed that treatment with fangchinoline significantly reduced the expression of collagen IV and CD31 in the kidneys compared to the control group. The expression of p38 MAPK, TNF-α, COX-2, and MMP-9 was also attenuated by fangchinoline treatment in the kidney tissues of DN rats. Together, the results of this study suggest that fangchinoline protects against nephron damage by attenuating alterations in the p38 MAPK pathway, thereby reducing oxidative stress and inflammation in DN rats.

Effects of cooperative blood transfusion and homologous blood transfusion on the production of red blood cell irregular antibodies in obstetric patients.

Effects of cooperative blood transfusion and homologous blood transfusion on the production of red blood cell irregular antibodies in obstetric patients were investigated. A total of 300 obstetric patients who underwent blood transfusion in the Maternity and Child Health Care of Zaozhuang from February 2016 to February 2018 were enrolled. There were 150 obstetric patients receiving the same type of transfusion who were included in the control group. Due to special circumstances the remaining 150 obstetric patients with ABO and Hr with cooperative blood transfusion were included in the research group. The positive detection rate of blood cell irregular antibody, the effectiveness of blood transfusion and the incidence of adverse transfusion reaction were observed in the two groups after the comparison of blood transfusion of both groups. The total positive detection rate of erythrocyte irregular antibody in the research and control groups was not statistically significant (P>0.05). There were no significant differences in the red blood cell counts, hemoglobin concentration, hematocrit and platelet count between the research and control groups after infusion (P>0.05). Comparing all the groups, the red blood cell counts, hemoglobin concentration, hematocrit and platelet count after infusion in both the research and control groups were significantly higher than before the infusion, and differences were statistically significant (P<0.001). There was no significant difference in the incidence of adverse reactions between the two groups (P>0.05). The effect of blood transfusion and homologous blood transfusion on the positive detection rate of red blood cell irregular antibody in obstetric patients, the efficiency of blood transfusion and the incidence of adverse transfusion reactions are similar, and all have high clinical application value.

Diosmetin Attenuates Akt Signaling Pathway by Modulating Nuclear Factor Kappa-Light-Chain-Enhancer of Activated B Cells (NF-κB)/Inducible Nitric Oxide Synthase (iNOS) in Streptozotocin (STZ)-Induced Diabetic Nephropathy Mice.

BACKGROUND We evaluated the nephroprotective effect of diosmetin in streptozotocin (STZ)-induced diabetic nephropathy (DN) mice. MATERIAL AND METHODS Diabetes was induced by injecting STZ (50 mg/kg) i.p. for 5 days. Biochemical parameters, such as fasting blood glucose, creatinine, BUN in the serum, and albumin in the urine, were determined in STZ-induced DN mice after the 8th week of STZ administration. The level of inflammatory mediators in the serum and oxidative stress parameters in the tissue homogenate was estimated in STZ-induced DN mice. Expressions of Akt, NF-κB, and iNOS in the tissue homogenate were assessed by Western blot analysis. RESULTS Our data reveal that treatment with diosmetin significantly reduces the fasting blood glucose (FBG), serum creatinine, and blood urea nitrogen (BUN) in the serum and albumin in urine compared to the negative control group. Treatment with diosmetin attenuated the altered level of oxidative stress parameters and inflammatory cytokines in the STZ-induced DN mice. Expression of Akt and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) was significantly reduced and inducible nitric oxide synthase (iNOS) was enhanced in the tissue homogenate of diosmetin-treated mice compared to the negative control group. Data from immunohistochemical analysis suggest that the expressions of NF-κB was significantly reduced in tissues of the diosmetin-treated group compared to the negative control group. CONCLUSIONS Our study shows that diosmetin protects against renal injury in STZ-induced diabetic nephropathy mice by modulating the Akt/NF-κB/iNOS signaling pathway.

NF-kappaB transcription factor p50 critically regulates tissue factor in deep vein thrombosis.

NF-kappaB transcription factors regulate the expression of tissue factor (TF), a principal initiator of the coagulation cascade. Dominant among them is the p50/p65 heterodimer. Here we report that Andrographolide (Andro; a p50 inhibitor) and genetic deletion of p50 attenuated TF activity in stimulated endothelial cells and monocytes/macrophages. Results of the electrophoretic mobility "supershift" assay and chromatin immunoprecipitation demonstrated the direct interaction of the p50/p65 heterodimer with the NF-kappaB site of the human TF promoter. Andro-treated and p50 null mice both exhibited blunted TF expression and reduced venous thrombosis, which were recapitulated by an anti-murine TF antibody in vivo. Our findings thus indicate that regulation of TF by NF-kappaB transcription factor p50 is essential for the pathogenesis of deep vein thrombosis and suggest that specific inhibitors of p50, such as Andro, may be therapeutically valuable for preventing and perhaps treating venous thrombosis.

Monte Carlo Simulation Study on the Time Resolution of a PMT-Quadrant-Sharing LSO Detector Block for Time-of-Flight PET.

We developed a detailed Monte Carlo simulation method to study the time resolution of detectors for time-of-flight positron emission tomography (TOF PET). The process of gamma ray interaction in detectors, scintillation light emission and transport inside the detectors, the photoelectron generation and anode signal generation in the photomultiplier tube (PMT), and the electronics process of discriminator are simulated. We tested this simulation method using published experimental data, and found that it can generate reliable results. Using this method, we simulated the time resolution for a 13 × 13 detector block of 4 × 4 × 20 mm(3) lutetium orthosilicate (LSO) crystals coupled to four 2-inch PMTs using PMT-quadrant-sharing (PQS) technology. We analyzed the effects of several factors, including the number of photoelectrons, light transport, transit time spread (TTS), and the depth of interaction (DOI). The simulation results indicated that system time resolution of 360 ps should be possible with currently available fast PMTs. This simulation method can also be used to simulate the time resolution of other detector design method.

HIGH-RESOLUTION L(Y)SO DETECTORS USING PMT-QUADRANT-SHARING FOR HUMAN & ANIMAL PET CAMERAS.

We developed high resolution L(Y)SO detectors for human and animal PET applications using Photomultiplier-quadrant-sharing (PQS) technology. The crystal sizes were 1.27 × 1.27 × 10 mm(3) for the animal PQS-blocks and 3.25 × 3.25 × 20 mm(3) for human ones. Polymer mirror film patterns (PMR) were placed between crystals as reflector. The blocks were assembled together using optical grease and wrapped by Teflon tape. The blocks were coupled to regular round PMT's of 19/51 mm in PQS configuration. List-mode data of Ga-68 source (511 KeV) were acquired with our high yield pileup-event recovery (HYPER) electronics and data acquisition software. The high voltage bias was 1100V. Crystal decoding maps and individual crystal energy resolutions were extracted from the data. To investigate the potential imaging resolution of the PET cameras with these blocks, we used GATE (Geant4 Application for Tomographic Emission) simulation package. GATE is a GEANT4 based software toolkit for realistic simulation of PET and SPECT systems. The packing fractions of these blocks were found to be 95.6% and 98.2%. From the decoding maps, all 196 and 225 crystals were clearly identified. The average energy resolutions were 14.0% and 15.6%. For small animal PET systems, the detector ring diameter was 16.5 cm with an axial field of view (AFOV) of 11.8 cm. The simulation data suggests that a reconstructed radial (tangential) spatial resolution of 1.24 (1.25) mm near the center is potentially achievable. For the wholebody human PET systems, the detector ring diameter was 86 cm. The simulation data suggests that a reconstructed radial (tangential) spatial resolution of 3.09(3.38) mm near the center is potentially achievable. From this study we can conclude that PQS design could achieve high spatial resolutions and excellent energy resolutions on human and animal PET systems with substantially lower production costs and inexpensive readout devices.