IKZF4/NONO-RAB11FIP3 axis promotes immune evasion in gastric cancer via facilitating PD-L1 endosome recycling.

As an immune checkpoint protein expressed by diverse cancer cells, programmed death ligand 1 (PD-L1) facilitates immune evasion by interacting with programmed cell death-1 (PD-1) on T cells. Despite the clinical benefits observed in various cancer types, strategies targeting PD-1/PD-L1 have demonstrated limited efficacy in gastric cancer (GC). Furthermore, the regulation of PD-L1, especially at post-translational modification levels, remains largely unknown. Therefore, it is crucial to elucidate the mechanisms governing PD-L1 expression to enhance anti-tumor immunity. In this study, we have identified that IKAROS family zinc finger 4 (IKZF4) and Non-POU domain-containing octamer-binding (NONO) synergistically regulate and enhance the expression of RAB11 family-interacting protein 3 (RAB11FIP3) in GC. The IKZF4/NONO-RAB11FIP3 axis facilitates the endosomal recycling of PD-L1, particularly on the cell membrane of GC cells. Moreover, overexpression of RAB11FIP3 mitigates the hypo-expression of PD-L1 protein resulting from IKZF4 or NONO deletion. Functionally, the silencing of RAB11FIP3 or IKZF4 promotes T cell proliferation, and enhances T-cell cytotoxicity towards GC cells in vitro, which further inhibits tumor immune evasion in mice via increasing the infiltration of CD8+ T cells into the tumor microenvironment (TME) to suppress GC progression. Our study suggests that the IKZF4/NONO-RAB11FIP3 axis promotes immune evasion by facilitating PD-L1 endosome recycling, thus presenting a potential therapeutic target for GC treatment.

Investigation of the acicular aragonite growth behavior in AOD stainless steel slag during slurry-phase carbonation.

This study presents a novel method for producing acicular aragonite using argon oxygen decarburization (AOD) slag while controlling the reaction temperature, reaction time, stirring speed, and the magnesium-to­calcium stoichiometric ratio. This approach provides steel plants with an opportunity to decrease their CO2 emissions and promote efficient resource utilization and CO2 storage through the production of high-quality value-added products. The experimental results showed that reaction temperature was the most significant factor affecting the carbonation efficiency of AOD slag, followed by reaction time, stirring speed, CO2 partial pressure, and the liquid-to-solid ratio (L/S). The study also found that elevated temperature and prolonged reaction duration favored the preferential precipitation of aragonite. Additionally, raising the temperature and the magnesium-to­calcium stoichiometric ratio was shown to enhance the formation of aragonite, affecting its crystal growth orientation and dimensions. The optimal combination of reaction parameters for the preparation of acicular aragonite was found to be the reaction time of 8 h, the magnesium-to­calcium stoichiometric ratio of 0.8, the reaction temperature of 120 °C, and the stirring speed of 200 r·min-1. Under these conditions, the resulting acicular aragonite exhibited excellent overall uniformity, a large aspect ratio, and a smooth crystal surface, with a content of 91.49 %, a single crystal length ranging from 9.86 to 32.6 µm, and a diameter ranging from 0.63 to 2.15 µm. This study provides valuable insights into the efficient production of acicular aragonite from steel slag while reducing CO2 emissions and promoting the sustainable use of resources.

Extracellular ATP-induced calcium oscillations regulating the differentiation of osteoblasts through aerobic oxidation metabolism pathways.

INTRODUCTION: The increase of ATP concentration in the extracellular space represents one of the effective signals that stimulate the physiological activities of cells when the bone is exposed to external mechanical stimulation such as stretching and shear stress force throughout life. However, the effects of ATP on osteoblast differentiation and related mechanisms are not well understood. MATERIALS AND METHODS: In this study, the roles of extracellular ATP on osteoblast differentiation, intracellular calcium ([Ca2+]i) levels, metabolomics, and the expression of proteins related to energy metabolism were investigated. RESULTS: Our results showed that 100 µM extracellular ATP initiated intracellular calcium ([Ca2+]i) oscillations via the calcium-sensing receptor (P2R) and promoted the differentiation of MC3T3-E1 cells. Metabolomics analysis showed that the differentiation of MC3T3-E1 cells depended on aerobic oxidation, but little glycolysis. Moreover, the differentiation of MC3T3-E1 cells and aerobic oxidation were suppressed with the inhibition of AMP-activated protein kinase (AMPK). CONCLUSION: These results indicate that calcium oscillations triggered by extracellular ATP can activate aerobic oxidation through AMPK-related signaling pathways and thus promote osteoblast differentiation.

Extracellular Calcium-Induced Calcium Transient Regulating the Proliferation of Osteoblasts through Glycolysis Metabolism Pathways.

During bone remodeling, high extracellular calcium levels accumulated around the resorbing bone tissue as soon as the activation of osteoclasts. However, if and how calcium is involved in the regulation of bone remodeling remains unclear. In this study, the effect of high extracellular calcium concentrations on osteoblast proliferation and differentiation, intracellular calcium ([Ca2+]i) levels, metabolomics, and the expression of proteins related to energy metabolism were investigated. Our results showed that high extracellular calcium levels initiated a [Ca2+]i transient via the calcium-sensing receptor (CaSR) and promoted the proliferation of MC3T3-E1 cells. Metabolomics analysis showed that the proliferation of MC3T3-E1 cells was dependent on aerobic glycolysis, but not the tricarboxylic acid cycle. Moreover, the proliferation and glycolysis of MC3T3-E1 cells were suppressed following the inhibition of AKT. These results indicate that calcium transient triggered by high extracellular calcium levels activated glycolysis via AKT-related signaling pathways and ultimately promoted the proliferation of osteoblasts.

Targeting Gastric Cancer Stem Cells to Enhance Treatment Response.

Gastric cancer (GC) was the fourth deadliest cancer in the world in 2020, and about 770,000 people died from GC that year. The death of patients with GC is mainly caused by the metastasis, recurrence, and chemotherapy resistance of GC cells. The cancer stem cell theory defines cancer stem cells (CSCs) as a key factor in the metastasis, recurrence, and chemotherapy resistance of cancer. It considers targeting gastric cancer stem cells (GCSCs) to be an effective method for the treatment of GC. For GCSCs, genes or noncoding RNAs are important regulatory factors. Many experimental studies have found that some drugs can target the stemness of gastric cancer by regulating these genes or noncoding RNAs, which may bring new directions for the clinical treatment of gastric cancer. Therefore, this review mainly discusses related genes or noncoding RNAs in GCSCs and drugs that target its stemness, thereby providing some information for the treatment of GC.

Improvement of Osteoporosis in Rats With Hind-Limb Unloading Treated With Pulsed Electromagnetic Field and Whole-Body Vibration.

OBJECTIVE: Physical factors have been used to address disuse osteoporosis, but their effects and mechanism remain unclear. The purpose of this study was to determine the effects of pulsed electromagnetic field (PEMF) and whole-body vibration (WBV) on disuse osteoporosis to increase knowledge about treating osteoporosis. METHODS: A disuse osteoporosis rat model was developed by hind-limb unloading (HU) for 6 weeks. Forty 4-month-old female Sprague-Dawley rats were divided into 5 groups and given the following interventions: HU, HU treated with PEMF (HUP), HU treated with WBV (HUW), HU treated with both PEMF and WBV (HUPW), and no intervention (controls). After 8 weeks of intervention, measurements were taken. RESULTS: HU induced a decrease in bone mineral density (BMD), whereas HUP, HUW, and HUPW increased it. Moreover, the bone resorption markers tartrate-resistant acid phosphatase (TRAP) and C-terminal peptide of type 1 collagen in the HU group significantly increased, whereas the osteogenesis markers osteocalcin and N-terminal propeptide of type 1 procollagen significantly decreased. The markers osteocalcin and N-terminal propeptide of type 1 procollagen significantly increased, but TRAP and C-terminal peptide of type 1 collagen significantly decreased in the HUPW, HUP, and HUW groups compared with the HU group. In particular, HUPW effectively increased osteocalcin and decreased TRAP compared with HUP and WBV. Microcomputed tomography analysis of the femur indicated that HUPW improved trabecular number, bone volume over total volume, bone surface over bone volume, trabecular separation, and the structure model index compared with HUP and that it improved bone surface over bone volume, trabecular separation, and structure model index compared with HUW. The HUPW group showed a significant increase in maximum load compared with the HUW group and a significant increase in elastic modulus compared with the HUP group. CONCLUSION: PEMF, WBV, and their combination all attenuated bone resorption and enhanced osteogenesis. WBV and the combination of treatments have great potential to improve osteogenesis compared with PEMF. In addition, HUPW significantly attenuated bone resorption compared with HUW and HUP. IMPACT: The results of this study indicated that HUPW could effectively improve disuse osteoporosis compared with HUP, given that trabecular number and bone volume over total volume are associated with disuse osteoporosis. Moreover, BMD recovered well with HUP, HUW, and HUPW but the bone structure-especially mechanical performance-did not, indicating that osteoporosis should be evaluated with BMD and mechanical performance, not with BMD in isolation.

Down-Regulated CLDN10 Predicts Favorable Prognosis and Correlates With Immune Infiltration in Gastric Cancer.

Background: CLDN10, an important component of the tight junctions of epithelial cells, plays a crucial role in a variety of tumors. The effect of CLDN10 expression in gastric cancer, however, has yet to be elucidated. Methods: Differential expression of CLDN10 at the mRNA and protein levels was evaluated using Oncomine, ULCAN, HPA and TIMER2.0 databases. Real-time polymerase chain reaction (RT-PCR) was utilized to further verify the expression of CLDN10 in vitro. Correlations between CLDN10 expression and clinical outcomes of gastric cancer were explored by Kaplan-Meier Plotter. Gene set enrichment analysis (GSEA) and protein-protein interaction (PPI) were performed via LinkedOmics and GeneMANIA. The correlations between CLDN10 expression and immune cell infiltration and somatic copy number alternations (SCNA) in gastric cancer were explored by TIMER2.0 and GEPIA2.0. Results: CLDN10 expression was lower in gastric cancer compared to adjacent normal tissues, and associated with better prognosis. CLDN10 also showed significant differences at different T stages, Lauren classification, treatments and HER2 status. PPI and GSEA analysis showed that CLDN10 might be involved in signal transmission, transmembrane transport and metabolism. In some major immune cells, low expression of CLDN10 was associated with increased levels of immune cell infiltration. In addition, it was found that different SCNA status in CLDN10 might affect the level of immune cell infiltration. Furthermore, the expression of CLDN10 was significantly associated with the expression of several immune cell markers, especially B cell markers, follicular helper T cell (Tfh) markers and T cell exhaustion markers. Conclusion: Down-regulated CLDN10 was associated with better overall survival (OS) in gastric cancer. And CLDN10 may serve as a potential prognostic biomarker and correlate to immune infiltration levels in gastric cancer.

Accuracy and Reliability of Computer-aided Anatomical Measurements for Vertebral Body and Disc Based on Computed Tomography Scans.

OBJECTIVE: To assess whether the computed tomography (CT)-based method of three-dimensional (3D) analysis (Mimics) was accurate and reliable for spine surgical anatomical measurements. METHODS: A total of 40 lumbar segments and 32 inter-vertebral discs from eigth adult male cadavers without fractures or deformities fixed with the classical formaldehyde method were included in this research on 5 June 2017. CT scans including seven dimensions: anterior height of the vertebral body (VBHa), middle height of the vertebral body (VBHm), posterior height of the vertebral body (VBHp), width of the upper endplate (EPWu), depth of the upper endplate (EPDu), anterior height of the inter-vertebral disc in the median sagittal plane (IDHa), and posterior height of the inter-vertebral disc in the median sagittal plane (IDHp). They were performed based on uniform conditions (slice thickness: 0.625 mm) using a CT scanner on 8 June 2017. Afterwards, the surgical anatomical measurements were conducted with a Vernier caliper on 12 June 2017. The computer-aided anatomical measurements were conducted by three investigators using Mimics 16.0 to perform 3D reconstructions of CT bone on 16 June 2017. Finally, the length and angle were measured with associated measurement tools, yielding a verified accuracy of 0.01 mm and 0.01°, respectively. Each measurement was repeated three times, and all anatomical data was analyzed using the statistical software and P-value < 0.05 was considered statistically significant. RESULTS: The results showed no statistically significant difference was observed between the surgical anatomical and computer-aided anatomical measurements (P > 0.05) for lumbar vertebra measurements, and the absolute difference between surgical and computer-aided data were all less than 1.0 mm (for the VBHa, VBHm, VBHp, EPWu, and EPDu were 0.12, 0.03, 0.03, 0.31, and 0.03 mm, respectively). Moreover, although the absolute differences of discs was larger than those of lumbar vertebras, no significant differences were detected between the computer-aided and surgical anatomical measurements for the IDHa, as well as IDHp in the vast majority of measurements (P = 0.543, 0.079 or 0.052 for IDHa, and P = 0.212, 0.133 or 0.042 for IDHp). In addition, excellent reliability correlation was observed between the measurements of each investigator, and the reliability coefficients in the intra-groups were all greater than 0.9 except for IDHp (reliability coefficient = 0.892). Additionally, the reliability coefficients were greater than 0.9 for the all between-group correlations, and a significant correlation was also observed. Furthermore, no statistically significant difference for three anatomical values was found in the computer-assisted measurements of the lumbar bone structure (P > 0.05). Similarly, we did not observe a statistical difference in the anatomical data of the lumbar discs from the three measures (P > 0.05). CONCLUSIONS: Computer-aided anatomical measurement for spine based on CT scans presents the high accuracy and reliability for improving spinal surgical procedures.

[Research progress on chemical constituents and quality control of Tripterygium wilfordii preparations].

Tripterygium wilfordii preparations,with various biological activities such as immunosuppressive,anti-inflammatory and anti-cancer effects,are widely used in the treatment of autoimmune diseases such as rheumatoid arthritis,lupus erythematosus,and nephrotic syndrome. They have definite therapeutic effect,but often cause serious adverse reactions and result in damages to liver,kidney,blood,reproduction,and other systems due to their complex compositions,great toxicity,and narrow margin between the toxic and therapeutic dosages. At present,T. wilfordii preparations produced by different manufacturers exhibit large variations in clinical efficacy and side effects in account of their different chemical compositions and quality fluctuation due to differences in raw materials and production process. However,the existing quality standards are controversial in terms of index components and content limit,which cannot be effectively used for the overall quality control of the preparations. In this paper,the research progress on chemical constituents,quality standard and quality control methods of four T. wilfordii preparations including Tripterygium Tablets,Tripterygium Zongtie Tablets,Tripterygium Shuangceng Tablets and Tripterygium Glycosides Tablets was reviewed,in order to provide ideas and reference for the quality improvement of this type of preparations.

[Reasons for anastomotic leakage following the learning curve by laparoscopic anterior resection of rectal cancer].

OBJECTIVE: To investigate the reasons of anastomotic leakage following learning curve by laparoscopic anterior resection of rectal cancer.
 Methods: From December, 2011 to March, 2015, the clinical information of 179 patients in our hospital who underwent dixon of rectal cancer were collected. The patients were divided into a laparoscopic learning group, a laparotomy group and a laparoscopic group. The reasons of anastomotic leakage for each group were comparatively analyzed. Repeated cutting of anastomotic stoma was compared between the laparoscopic learning group and the laparoscopic group. The male, age, obesity, nutrition complications and the position of anastomotic stoma were compared among the 3 groups.
 Results: The rate of anastomotic leakage in the laparoscopic learning group was significantly higher than that in the laparotomy group and the laparoscopic group (P<0.05). Repeated cutting was a significant risk factor in the laparoscopic learning group (P<0.05), but not in the laparoscopic group. Except obesity, the four factors were significant risk factors in the laparoscopic learning group (P<0.05). All of the five factors were not the significant risk factors in the laparotomy group and the laparoscopic group (P>0.05).
 Conclusion: The operation technical shortcoming is the major factor in the learning of the laparoscopic anterior resection of rectal cancer. In order to reduce the rate of anastomotic leakage in the learning curve period, the selection of patients following the laparoscopic anterior resection of rectal cancer should avoid the following factors: male, older age, the low position of the tumor and the nutrition complications.

Pulsed electromagnetic fields promote the proliferation and differentiation of osteoblasts by reinforcing intracellular calcium transients.

Pulsed electromagnetic fields (PEMF) can be used to treat bone-related diseases, but the underlying mechanism remains unclear, especially the process by which PEMFs initiate biological effects. In this study, we demonstrated the effects of PEMF on proliferation and differentiation of osteoblasts using the model of calcium transients induced by high extracellular calcium. Our results showed that PEMF can increase both the percentage of responding cells and amplitude of intracellular calcium transients induced by high extracellular calcium stimulation. Compared with corresponding extracellular calcium levels, PEMF stimulation increased proliferation and differentiation of osteoblasts and related gene expressions, such as insulin-like growth factor 1 (IGF-1), alkaline phosphatase (ALP), runt-related transcription factor 2 (Runx2), and osteocalcin (OCN), which can be completely abolished by BAPTA-AM. Moreover, PEMF did not affect proliferation and differentiation of osteoblasts if no intracellular calcium transient was present in osteoblasts during PEMF exposure. Our results revealed that PEMF affects osteoblast proliferation and differentiation through enhanced intracellular calcium transients, which provided a cue to treat bone-related diseases with PEMF. Bioelectromagnetics. 38:541-549, 2017. © 2017 Wiley Periodicals, Inc.

[Usefulness of self-made gasbag double-cannula stool drainage device for prevention of anastomotic leakage following anterior resection].

OBJECTIVE: To evaluate the efficacy of self-made gasbag double-cannula stool drainage device for prevention of anastomotic leakage following anterior resection. METHODS: Clinical data of 169 rectal cancer patients in the 8th Affiliated Hospital of Sun Yat-sen University between October 2010 and October 2016 were retrospectively analyzed. Among them, a self-made gasbag double-cannula stool drainage device was placed in 71 patients(stool drainage group), and the remaining 98 patients were taken as control. After an anastomosis, the drainage device was transanally placed by the assistant and the distal tube of drainage device was stretched more than 15 cm from anastomosis. The gasbag was inflated to fully expand the intestine. The main tube was fixed on perianal skin with 7-0 suture, kept more than 3-5 cm outside the anus, and connected to the drainage bag. The incidence of anastomotic leakage was compared between the two groups. RESULTS: The baseline data were similar between the two groups (all P>0.05). The differences in operative time, intraoperative blood loss, and time to bowel function recovery were not statistically significant (all P>0.05), however, time to oral intake and postoperative stay were shorter in stool drainage group as compared to the control group (both P<0.05). There was no perioperative death in both groups. In stool drainage group, there were 6 cases whose drainage device was pulled out within 48 hours due to intolerance. The ruptured gasbag was replaced 5 times and the tube was clogged by fecal material 21 times. After flushing, the tube did not recanalized and was pulled out in 3 cases. The incidence of anastomotic leakage in stool drainage group was significantly lower than that in the control group (2.8% vs. 11.2%, P=0.043). As for the low anastomosis (the distance to anal verge less than 5 cm), the incidence of anastomotic leakage in stool drainage group was also significantly lower than that in the control group (2.3% vs. 15.4%, P=0.028), while as for the high anastomosis, the difference was not statistically significant (3.6% vs. 3.0%, P=0.906). Logistic regression analysis revealed that the presence of a stool drainage device was an independent protective factor for anastomotic leakage (OR=0.316, 95%CI:0.114 ~ 0.769, P=0.003). CONCLUSIONS: The self-made gasbag double-cannula stool drainage device effectively prevents anastomotic leakage after anterior resection of rectal cancer. However it is not suitable for those patients with high anastomosis.

Effects of extremely low frequency electromagnetic fields on intracellular calcium transients in cardiomyocytes.

Calcium transients play an essential role in cardiomyocytes and electromagnetic fields (EMF) and affect intracellular calcium levels in many types of cells. Effects of EMF on intracellular calcium transients in cardiomyocytes are not well studied. The aim of this study was to assess whether extremely low frequency electromagnetic fields (ELF-EMF) could affect intracellular calcium transients in cardiomyocytes. Cardiomyocytes isolated from neonatal Sprague-Dawley rats were exposed to rectangular-wave pulsed ELF-EMF at four different frequencies (15 Hz, 50 Hz, 75 Hz and 100 Hz) and at a flux density of 2 mT. Intracellular calcium concentration ([Ca(2+)]i) was measured using Fura-2/AM and spectrofluorometry. Perfusion of cardiomyocytes with a high concentration of caffeine (10 mM) was carried out to verify the function of the cardiac Na(+)/Ca(2+) exchanger (NCX) and the activity of sarco(endo)-plasmic reticulum Ca(2+)-ATPase (SERCA2a). The results showed that ELF-EMF enhanced the activities of NCX and SERCA2a, increased [Ca(2+)]i baseline level and frequency of calcium transients in cardiomyocytes and decreased the amplitude of calcium transients and calcium level in sarcoplasmic reticulum. These results indicated that ELF-EMF can regulate calcium-associated activities in cardiomyocytes.

An oxygen enrichment device for lowlanders ascending to high altitude.

BACKGROUND: When ascending to the high altitude, people living in low altitude areas will suffer from acute mountain sickness. The aim of this study is to test the hypothesis that whether an oxygen concentration membrane can be made and used to construct a new portable oxygen enrichment device for individuals in acute exposure to the high altitude. METHODS: The membrane was fabricated using vinylsiloxane rubber, polyphenylene oxide hydrogen silicone polymers, chloroplatinic acid and isopropyl alcohol. The membrane was assembled in a frame and the performance was tested in terms of concentration of oxygen, flow rate of oxygen enriched air, pressure ratio across the membrane and ambient temperature. Furthermore, the oxygen concentration device was constructed using the membrane, a DC fan, vacuum pump and gas buffer. A nonrandomized preliminary field test was conducted, in which eight healthy male subjects were flown to Tibet (Lhasa, 3,700 m). First, subjects wore the oxygen enrichment device and performed an incremental exercise on cycle ergometer. The test included heart rate (HR), saturation of peripheral oxygen (SpO2) and physical work capacity (PWC). Then, after a rest period of 4 hours, the experimental protocol was repeated without oxygen enrichment device. RESULTS: The testing showed that the membrane could increase the oxygen concentration by up to 30%. Simulation test indicated that although the performance of the oxygen enrichment device decreased with altitudes, the oxygen concentration could still maintain 28% with flow rate of enriched air 110 cm3/s at 5000 m. The field test showed that higher SpO2, lower HR, and better PWC (measured by the PWC-170) were observed from all the subjects using oxygen enrichment device compared with non-using (P < 0.01). CONCLUSIONS: We concluded that the new portable oxygen enrichment device would be effective in improving exercise performance when ascending to the high altitude.

Evaluation to the antioxidant activity of total flavonoids extract from persimmon (Diospyros kaki L.) leaves.

Persimmon leaves are commonly consumed as beverages, but are also used as a popular folk medicine in China. The purpose of this work is to assess the antioxidant activity of an extract of total flavonoids from persimmon leaves (TFPL). The effect of TFPL on total antioxidant activity, reducing power, 1,1-diphenyl-2-picrylhydrazyl (DPPH()) radical scavenging, superoxide anion (()O(2)(-)) radical scavenging, hydroxyl (OH()) radical scavenging and metal chelating activities was examined. We found that TFPL possesses considerable amounts of flavonoids (192µg catechin equivalent/g of extract). The effect of this extract in total antioxidant activity, scavenging activity of superoxide anion and hydroxyl radical, reducing power and iron chelating activity was significantly better than that of rutin. However, the effect of TFPL in free radical scavenging of DPPH() was significantly not as good as than rutin. In addition, TFPL significantly decreased the level of reactive oxygen species (ROS) and malondialdehyde (MDA), while increasing the activity of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in MC3T3-E1 cells in a dose-dependent manner. In conclusion, TFPL possess potent antioxidant and free radical scavenging activities. These antioxidant activities could contribute, at least in part, to the traditionally claimed therapeutic benefits of persimmon leaves.

Sulphated modification of a polysaccharide obtained from fresh persimmon (Diospyros kaki L.) fruit and antioxidant activities of the sulphated derivatives.

Free radicals and other reactive oxygen species (ROS) are believed to play significant roles in ageing as well as in a number of degenerative or pathological diseases. This paper reports the preparation, characterisation and potential antioxidant activity of a type of chemically sulphated polysaccharide isolated from fresh persimmon (Diospyros kaki L.) fruit. Three sulphated derivatives with variable degrees of substitution (0.8, 1.7 and 2.5) were obtained by the chlorosulphonic acid-pyridine method. The sulphated derivatives all showed dose-dependent reducing power and free radical scavenging effect of 1,1-dipheny-l-2-picrylhydrazyl, superoxide anion and hydroxyl. Our results showed that the sulphated modification of polysaccharides significantly increased their antioxidant activities and may be an effective way to prepare these valuable derivatives.

Sulfated modification and immunomodulatory activity of water-soluble polysaccharides derived from fresh Chinese persimmon fruit.

In this study, three kinds of chemically sulfated polysaccharides (PFP-S) were derived from a water-soluble polysaccharide of persimmon fruit with chlorosulfonic acid-pyridine method. Relationship between the degree of substitution and immunomodulatory activity of PFP-S was examined with the splenocytes experiment. The results showed that the splenocytes-activating activity was significantly enhanced by PFP-S in all the groups compared with control group (P<0.01). PFP-SII exhibited the most potent splenocytes-activating activity by increased cytokine production and NO release. It also suggested that the sulfate groups and molecular weight of polysaccharides are key factors to regulate the immunomodulatory activities.

Influence of paeonol on expression of COX-2 and p27 in HT-29 cells.

AIM: To investigate the effect of paeonol on controlling the proliferation of colorectal cancer cell line HT-29 and to discuss its possible mechanism. METHODS: The inhibitory effect of paeonol on proliferation of HT-29 cells was detected by MTT assay. The results of apoptosis were measured by flow cytometry. Immunocytochemical staining was performed to detect the expression of cyclooxygenase-2 (COX-2) and protein p27 in HT-29 cells treated with paeonol at different concentrations. Reverse transcription-polymerase chain reaction (RT-PCR) was used for mRNA analysis. RESULTS: From the data of both MTT and flow cytometry, we observed that cell proliferation was inhibited by different concentrations of paeonol. By immunocytochemical staining, we found that HT-29 cells treated with paeonol (0.024-1.504 mmol/L) reflected reduced expression of COX-2 and increased expression of p27 in a dose-dependent manner. RT-PCR showed that paeonol down-regulated COX-2 and up-regulated p27 in a dose- and time-dependent manner in HT-29 cells. CONCLUSION: One of the apoptotic mechanisms of paeonol is down-regulation of COX-2. p27 is up-regulated simultaneously and plays an important part in controlling cell proliferation and is a crucial factor in the Fas/FasL apoptosis pathway.

[The effects of extremely low-frequency electromagnetic fields on rat osteoblast].

The performance of extremely low-frequency electromagnetic fields (ELEF) can change the response of osteoblasts. In this study a kind of ELEF stimulator, which can radiate sinusoidal, rectangular, triangular and pulsed burst ELEF with frequency of 0-300 Hz and strength of 0-40 mT was developed. The neonatal rat calvarial osteoblasts were treated with the device. The effects of various ELEF stimulation on the osteoblast were evaluated by its proliferation and differentiation. The results demonstrated that rectangular and pulsed burst radiation (15Hz, 5mT) can positively change the proliferation of the osteoblast and inhibit its differentiation, but the sinusoidal one can significantly enhance its differentiation and decrease its proliferation.

Effects of different extremely low-frequency electromagnetic fields on osteoblasts.

It is well known that the extremely low-frequency electromagnetic field (EMF) can promote the healing of bone fractures, but its mechanism remains poorly understood. The purpose of this study was to examine the response of neonatal rat calvarial bone cells to the rectangular electromagnetic field (REMF), triangular electromagnetic field (TEMF), sinusoidal electromagnetic field (SEMF), and pulsed electromagnetic field (PEMF). The stimulatory effects of EMF were evaluated by the proliferation (methyltetrazolium colorimetric assay), differentiation (alkaline phosphatase (ALP) activity), and mineralization (area of mineralized nodules of the cells). REMF treatment of osteoblasts increased cellular proliferation and decreased ALP activity (p < 0.05). TEMF had an accelerative effect on the cellular mineralized nodules (p < 0.05). SEMF treatment of osteoblasts decreased the cellular proliferation, increased ALP activity, and suppressed mineralized nodules formation (p < 0.05). PEMF promoted the proliferation of osteoblasts, inhibited their differentiation, and increased the mineralized nodules formation (p < 0.05). Moreover, the effects of PEMF on osteoblasts were concerned with the extracellular calcium, P2 receptor on the membrane, and PLC pathway, but the response of osteoblasts on SEMF was only related to PLC pathway. The results suggested that the waveforms of EMF were the crucial parameters to induce the response of osteoblasts.