Effects of Acetylsalicylic Acid (ASA) and Ethylene Treatments onRipening and Softening of Postharvest Kiwifruit

Kiwifruit (Actinidia deliciosa (A. Chev.) C. F. Liang et A. R. Ferguson cv. Bruno) was used toinvestigate the effects of acetylsalicylic acid (ASA, 1.0 mmol/L, pH 3.5) and ethylene (100 mL/L) treat-ments on changes at endogenous salicylic acid (SA) levels and other senescence-related factors duringfruit ripening and softening at 20 ℃. The level of endogenous SA in ripening fruits declined and a closerelationship was observed between the change at endogenous SA level and the rate of fruit ripening andsoftening. ASA treatment elevated SA level in the fruit, slowed down the increases in lipoxygenase (LOX)and allene oxide synthase (AOS) activities, decreased the O22-. production in the preclimacteric phase andthe early phase of ethylene climacteric rise, maintained the stability of cell membrane, inhibited ethylenebiosynthesis, postponed the onset of the ethylene climacteric, and delayed the process of fruit ripeningand softening. On the contrary, application of ethylene to ripening kiwifruit resulted at a lower SA level, anaccelerated increases in the activities of LOX and AOS and the rate of O22-. production, an elevated relativeelectric conductivity and an advanced onset of ethylene climacteric, and a quicker fruit ripening andsoftening. It is suggested that the effects of ASA on ripening kiwifruit can be attributed to its ability toscavenge O22-. and/or to maintain stability of cell membrane.

Application of advanced oxidation processes for removing salicylic acid from synthetic wastewaters

In this study,advanced oxidation processes(AOPs) such as anodic oxidation(AO),UV/H_2O_2 and Fenton processes(FP) were investigated for the degradation of salicylic acid(SA) in lab-scale experiments.Boron-doped diamond(BDD) film electrodes using Ta as substrates were employed for AO of SA.In the case of FP and UV/H_2O_2,most favorable experimental conditions were determined for each process and these were used for comparing with AO process.The study showed that the FP was the most effective process under aci...

Quantitative analysis of sialic acids in Chinese conventional foods by HPLC-FLD

Background: Sialic acids are a family of ninecarbon sugar compounds with carboxylic acyl derivatives. It exists in bacteria, fish, mammals and other living organisms, participates in and regulates many important life events, such as cell recognition, membrane flow, endocytosis and so on. Sialic acid is usually located in the outermost layer of the sugar part of the cell membrane and the key positions of secreted glycoconjugates (glycolipids, glycoprotein and lipopolysaccharide). Sialic acid (Sia) is an important material foundation for variety of the structure and founction of glycoconjugates. Sia has been known as nearly 50 members, including N-acetylneuraminic acid (Neu5Ac), N-glycoulylneuraminic acid (Neu5Gc) and deaminoneuraminic acid (KDN) as its core monomer. The rest of the sialic acids are derived from these three monomers. The contents of Sia in Chinese food products are unknown. Objective: To determine the contents of Sia in raw and cooked red meat, seafood, poultry and so on. Design: The following food products were purchased from a Chinese supermarket: pork, beef, lamb, salmon, cod, tuna, cow milk, cheese, butter, duck, chicken and chicken eggs. Human milk was collected from Xiamen Maternity and Child Health Care Hospital (Xiamen, China). All tissues were homogenized and hydrolyzed with 0.05 M, 0.1 M and 0.2 M TFA for 150 min at 80°C in dark, respectively. The concentrations of Neu5Ac, Neu5Gc and KDN were determined by using HPLC with fluorescence detector. Results: The contents of total Sia (μg/g tissue or μg/mL liquid sample) in Chinese raw meat were highest in lamb (269.60), followed by pork (254.88), duck (200.63), chicken (162.86) and beef (88.03). The percentages of Neu5Gc were 36.08%, 26.48%, 0%, 0% and 28.40%, respectively. Cod contained higher levels of Sia (171.63) than salmon (104.43) and tuna (77.98). Only Neu5Ac was 50 found in detected aquatic product. Egg yolk contained the highest level of Sia (682.04), and a higher level of Sia (390.67) was found in the egg white. Also our result showed that human milk contained extremely high level of Sia (602.55). Neu5Ac was the predominant form of Sia in all the deteced samples. KDN was found in cow milk only among the samples, the content was 1.14 μg/g. Conclusion: The highest content of Sia in examined Chinese foods was found in 56 eggs, followed by lamb, pork, duck, cod, chicken, salmon, beef and tuna. Knowledge of the Sia content in conventional foods may help us to better understand possible medical disorders involving the uptake of the “non-human” Neu5Gc from our diet.

Application of sialic acid/polysialic acid in the drug delivery systems

The properties of modified biomaterial are gaining more and more importance in drug delivery systems.Sialic acid(SA)and polysialic acid(PSA)serve as endogenous substances,which are non-immunogenic and biodegradable.At the same time,SA modification of the drugs/carriers can enhance the uptake of tumor cell and retention in brain;PSA modifi-cation can reduce the immunogenicity of the proteins or polypeptides and increase circulation time of the modified drugs/carriers in the blood,thus achieving active targeting effect.These properties offer a variety of opportunities for applications in drug delivery systems.This article summarizes the biological functions of SA and PSA and presents the technologies of SA/PSA modified small molecule drugs,proteins and carriers in drug delivery systems.

Structural Aberrations of Cellular Sialic Acids and Their Functions in Cancer Metastases

Sialic acids (neuraminic acids) are a special series of 9 carbon ring negatively charged carbohydrates, which has been found to be selectively changed in malignant cells from structures (both synthesis and structure modifications) to functions (up and down regulation in cells). Sialic acids, in single forms or conjugates, have been systematically studied both in lab and in clinics by GC, GC MS, NMR, HPTLC, HPLC and other modern analytical means. Sialic acids and related conjugates are predicted to be used in cancer diagnosis, cancer prognostic forecasting, designing of cancer chemotherapy regimens, uncovering carcinogenetic processes and neoplasm metastasis. Tumor cell regulative systems and pathways are correlated with sialic acids, which can be applied to prognostic evaluation of cancer patients, and antimetastatic chemotherapy by sialic acid derivatives and analogues. Searching for new biological characteristics of sialic acids in cells have also been extensively studied these days. In this paper, main stream discoveries and advancements are provided , also discussions of possible mechanisms and hypotheses are invoked.

ROLE OF SIALIC ACID RESIDUES IN IRON BINDING BY HUMAN LACTOFERRIN

Lactoferrin(Lf-α)is a major constithent of the secondary granules of neutrophils, and is thought to be involved in bacteriostasis through high affinity binding of plasma Fe required for microbial growth.Lf-αis also the major Fe binding protein in milk. Fe bound to Lf-αis available for metabolic use.but the mechanism of Fe release from Lf-αis unknown.Treatment of human Lf-α with neuraminidase to remove sialic acid residues reduced its ability to bind Fe and caused release of Fe already bound to the protein. Reduction in Fe binding capacity was dependent on time of exposure to and concentration of neuraminidase,and was due to Lf-αloss or degradation. Readdition of sialic arid to desialylated Lf -a using a-2, 6-sialyltransferase restored Fe binding.The results suggest that sialylationdesialylation reactions could play a role in physiologic binding and release of Fe from the very high affinity binding sites of Lf -α.

APOPTOSIS OF EPIDIDYMIS EPITHELIUM AND CONTENT OF EPIDIDYMIS SIALIC ACID FOLLOWING TORSED/DETORSED TESTES IN RAT

Objective To investigate the apoptosis of epididyrnis epithelium and the change of epididymissialic acid following torsed/detorsed testes. Methods Twenty four adult male Sprague-Dawley rats were subjected to unilateral 720 testicular torsion with the duration of 2h and 4h, then repaired. The ischemic epididymis were collected for detecting the content of sialic acid by using spectrophotometry and the apoptosis with TUNEL technique. Results There were no statistically significant difference in the apoptosis of epididymis epithelium [(9.51± 2.78)% vs (6.34±1. 98)%] and the content of epididymis sialic acid(23, 3851 ± 9. 2199mg/mgprot vs 19. 3661 6. 3373mg/mgprot) at 24h between following 2h-torsed/detorsed testes and those of sham group. There were statistically significant difference in the apopotosis of epididymis epithelium[ (46. 81 ±3. 55)% vs (6. 34±1. 98) % ] and the content of epididymis sialic acid (13. 7249±7. 8006mg/mgprot vs 19. 3661±6. 3373mg/mgprot) at 24h between following 4h-torsed/detorsed testes and those of sham group(P <0. 05). Conclusion The results suggest that the sialic acid-secreting-function of epididymis remain normal at 24h following 2h-torsed/detorsed testes, while the apoptosis index of epididymis epithelium do not increase. The epididymis would be injured at 24h following 4h-torsed/detorsed testes, while the apoptosis index increased.

SERUM LIPID-BOUND SIALIC ACID IN LUNG CANCER PATIENTS

Serum lipid-bound sialic acid (LSA) assay was evaluated for differential diagnosis between benign and malignant pulmonary disease.Mean serum LSA for normal controls was 13.7±3.7 mg/dl and the upper limit of the normal value was set at 19.8 mg/dl (95% confidence limit,one side).The specificity was 97.l% (95% confidence interval was 93.8%, 100.0%).The mean for benign pulmonary disease was 1 7.l±5.l mg/dl,the specificity was 89.l% (95% confidence interval was 80.9%,97.3%), and the sensitivity was 10.9%.The mean for malignant pulmonary disease was 27.l±7.9 mg/dl, and the sensitivity was 93.3%(95% confidence interval was 88.5%, 98.1%).The serum LSA levels for different malignant pulmonary diseases were different between small cell carcinoma and adenocarcinoma. The results indicate that serum LSA assay might be used as tumor marker to differentiate lung cancer from normal subjects or benign lung disease.

Blockade of neutrophil recruitment to tumor sites based on sialic acid-modified nanoplatforms enhances the efficacy of checkpoint blockade immunotherapy

Checkpoint inhibitors are designed to rejuvenate depleted or suppressed T cells in the tumor microenvironment,relying on the immune system to control and kill tumors.However,accumulating evidence indicates that tumor-infiltrating neutrophils impede the proliferation and activation of T cells and determine the resistance to checkpoint blockade and chemotherapy.In this study,sialic acid ligand-modified colchicine derivative phospholipid complexes specifically targeted tumor-associated neutrophils in the peripheral blood,blocked neutrophil accumulation in tumors,and attenuated the inhibitory effect of infiltrating neutrophils on T cells.Neutrophil blocking therapy enhanced the immunotherapy effect of the PD-L1 antibody in S180 advanced tumors and 4T1 breast cancer.Our study found that PD-L1 antibody monotherapy increased the tumor infiltration of immunosuppressive neutrophils.Combination therapy with neutrophil blocking can greatly reduce tumor-infiltrating neutrophils and increase the proliferation of cytotoxic CD8^(+) T lymphocytes in the tumor.The combination therapy significantly improved the survival rate of mice with advanced S180 tumors and increased the sensitivity of immune checkpoint inhibitors to 4T1 cold tumors.

不同浓度外源SA对“赤霞珠”果实品质的影响

以8年生酿酒葡萄品种“赤霞珠”为试验材料,在葡萄转色期7月下旬到8月上旬喷施SA,探究在果实发育中SA对果实品质的影响,为改善酿酒葡萄品质提供参考。结果表明,对葡萄叶面喷施SA,整个生长周期“赤霞珠”百粒重无显著差异,葡萄进入转色期后,各SA处理下葡萄果实中糖类物质均逐渐增加,有机酸含量逐渐减少,采收期时,糖类物质含量达到最高,有机酸含量达到最低。采收期(花后110 d),5 mmol/L SA处理可以明显降低葡萄中可滴定酸含量,3 mmol/L SA处理可以显著提高葡萄果实中糖类物质和酚类物质含量。3 mmol/L SA处理有利于“赤霞珠”葡萄果实品质的改善。

Bitter Melon (Momordica Charantia) Reduces Serum Sialic Acid in Type2 Diabetics: Evidence to Delay the Process of Atherosclerosis

More than 1000 herbal products have been used by diverse cultures of the world to treat hyperglycemia and among them bitter melon (Momordica charantia) is one of the most popular herbal resource. The beneficial effects of bitter melon is not limited to hypoglycaemia only, but it also ameliorates diet induced obesity, insulin resistance and exhibit cardioprotective effects. The present study attempts to investigate the effect of bitter melon fruit juice on a newly investigated risk factor, sialic acid in type2 diabetics. A total of 40 type2 diabetic patients, divided into group A (n = 20) and group B (n = 20) were investigated during the present study. The patients of group A were following bitter melon fruit juice treatment along with diet control, whereas the patients of group B were on diet control only. Serum sialic acid (SSA) decreased in group A from 66.20 ± 2.30 mg/dl to 63.50 ± 2.10 mg/dl (<0.11) but, increased in group B from 66.50 ± 1.70 mg/dl to 68.20 ± 2.50 mg/dl (<0.12), compared to baseline. Post-treatment between group comparison revealed a significant difference (<0.05). The beneficial effects on fasting plasma glucose (FPG) and glycohemoglobin (HbA1-c) were also greater in group A compared to group B as was the case with blood lipids, weight and blood pressure. The study provides another mechanism for the cardioprotective effect of bitter melon and further strengthens its value in the management of type2 diabetes.

Correlation of Cerebrospinal Fluid Sialic Acid with Various Enzymes in Patients with Meningitis

Meningitis is often associated with cerebral compromise which may be responsible for neurological squeal in nearly half of the survivors. Little is known about the mechanisms of Central Nervous System （CNS） involvement in bacterial meningitis. The present study was undertaken to assess the changes in biochemical parameters including glucose, protein, Sialic Acid （SA） and various enzymes like Aspartate Aminotransferase （AST）, Alanine Aminotransferase （ALT）, Creatine Kinase （CK）, Gamma Glutamyltranspeptidase 7 （GGTP） and Lactate Dehydrogenase （LDH） have been determined in the Cerebrospinal Fluid （CSF） of the meningitis patients （n = 26） and compared with control subjects （n = 26）. Total Protein, CK, SA （P 〈 0.02）, AST （P 〈 0.001） and ALT （P 〈 0.0001） of meningitis patients were significantly higher, whereas, glucose （P 〈 0.05） and Gamma Glutamyltranspeptidase （GGT） （P 〈 0.01 and P 〈 0.05, respectively） were significantly lower than those of the controls. This study suggests that loss of integrity of brain-CSF barriers, sialic acid and enzyme profiles may contribute to the severity and neurological complications of meningitis.

New Extracellular Bacillus subtilis Lectins with Sialic Acid-Specificity

The purpose of this work is to perform a detailed study of carbohydrate specificity of the new extracellular bacilli lectins which is considered to determine mechanisms of the lectins action. Sources of lectins were bacterial strains from Ukrainian collection of microorganisms. The optimized protocol of bacilli lectins isolation and purification included precipitation with ammonium sulfate with subsequent gel filtration chromatography on Sepharose CL-6B. Hemagglutinating activity of bacilli lectins and their fine carbohydrate specificity to sialic acids and their derivatives as well as sialic asid-containing and asialic glycoconjugates were studied. The ability of extracellular bacilli lectins to discriminate a- and 13-conformation of carbohydrate molecule and the type of connection between the monomers was determined. Studied lectins showed the most affinity to glycoconjugates containing both types of sialic acids （N-acetylneuraminic acid （Neu5Ac） and N-glycolylneuraminic acid （NeuGc）） and it is supposed to be a basis of their diagnostic and analytical potential.

Science Letters:Anodic oxidation of salicylic acid at Ta/BDD electrode

Boron-doped diamond （BDD） film electrodes using Ta as substrates were employed for anodic oxidation of salicylic acid （SA）. The effects of operational variables including initial concentration, current density, temperature and pH were examined. The results showed that BDD films deposited on the Ta substrates had high electrocatalytic activity for SA degradation. There was little effect ofpH on SA degradation. The current efficiency （CE） ,aas fbund to be dependent mainly on the initial SA concentration, current density and temperature. Chemical oxygen demand （COD） was reduced from 830 mg/L to 42 mg/L under a current density of200A/m^2 at 30℃.

Effects of Salicylic Acid on the Growth and Some Physiological Characters in Salt Stressed Tomato Plants （ Solanum L ycopersicum）

Excessive soil salinity is an important constraint limiting the distribution of plants in natural habitats, and is an increasingly severe agricultural problem in arid and semi-arid regions. Higher salinity levels caused significant reduction in growth parameters like leaf area, leaf length and root and shoot dry weight. Salicylic acid （SA）, a plant phenolic is now considered as a hormone-like endogenous regulator, and its role in the defence mechanisms against biotic stressors has been well documented. In recent years its role has been widely investigated in abiotic stress （salinity, drought, water deficit and so on）. The aim of the present work was to study the effects of salicylic acid on growth and some physiological characters of salt stressed tomato plants. The presence of salicylic acid at low concentration （0.01 mM） in culture medium riched with NaCl 100 mM （6 g·L^-1） improves the tolerance of tomato cv. Golden Sunrise to salinity. This amelioration results in stimulation of growth and development of plants. The applied of SA in saline medium induce： （i） an increase in chlorophyll content; （ii） a better supply of essential elements in plant growth, such as K＋; （iii） a decrease in toxic ions such Na＋ and CI in aerial organs; and （iv） an additional synthesis of organic solutes and osmoprotectors like proline and proteins. All these results suggest that salicylic acid could be successfully used in alleviating depressive effects of salt on the productivity of the cultivated tomato.

盐胁迫下SA在大花烟草中以剂量依赖方式调节种子萌发和生长

以改造的大花烟草(Nicotiana alata)即早花烟草为试材,研究在1500 mmol·L^(-1)氯化钠(NaCl)胁迫下,不同浓度梯度外源水杨酸(SA)处理下早花烟草种子的萌发情况和植株的生长状况,分析其过氧化物酶(POD)酶活性、超氧化物歧化酶(SOD)酶活性和活性氧(ROS)含量,及其作用机制.研究结果表明,适量外源SA可以缓解盐胁迫对早花烟草萌发的毒害.经0.05~1.00 mmol·L^(-1) SA处理,盐胁迫下早花烟草种子的发芽势、发芽率、发芽指数及活力指数上升,但随着SA浓度继续升高,其缓解效应随之降低.盐胁迫下的早花烟草生长已经受到严重抑制.喷施0.5~1.5 mmol·L^(-1) SA后,叶片大小和鲜重、根系的大小和鲜重都明显升高;且喷施0.5~2.0 mmol·L^(-1) SA叶片中SOD和POD活性均呈现先降低后上升的趋势;ROS含量呈现先降低后上升的趋势;叶绿素含量呈现出先上升后降低的趋势.这些结果表明:SA调节耐盐性可能以剂量依赖的方式发生,在外源施加适量浓度的SA提高抗氧化酶活性,能有效地消除过量的ROS,避免ROS积累,降低叶片中叶绿素含量及对光系统和光合碳同化过程中多种酶的伤害,维持较高的光合速率.

乳腺癌患者手术前后血清CA15-3、SA和SIL-2R检测的临床意义

目的:探讨乳腺癌患者手术前后血清CA15-3、SA和SIL-2R水平的变化及临床意义。方法:应用放射免疫分析、分光光度法和酶联法对31例乳腺癌患者进行手术前后血清CA15-3、SA和SIL-2R检测,并与35例正常人作比较。结果:乳腺癌患者在手术前血清CA15-3、SA和SIL-2R水平均非常显著地高于正常人组(P<0.01),手术3个月后则与正常人组比较无显著性差异(P>0.05)。结论:乳腺癌患者血清CA15-3、SA和SIL-2R含量的变化与疾病的发生和发展密切相关。

血清SA、Fuc、APP测定对AFP(-)HCC的诊断价值

本文对31例血清甲胎蛋白(AFP)阳性原发性肝细胞性肝癌(HCC)、33例AFP(—)HCC、35例肝硬化和58例正常献血清唾液酸(SA)、岩藻糖(Fuc)及五种急性期蛋白(APP)[a_1-酸性糖蛋白(a_1-AG)、结合珠蛋白(HP)、a_1-抗胰蛋白酶(a_1-AT)、前白蛋白(PA)和转铁蛋白(TF)]同时进行测定.结果表明AFP(—)肝癌组患者血清SA、Fuc、a_1-AG、HP及a_1-AT均显著高于对照组,其中,Fuc、a_1-AG与HP又比AFP(+)肝癌组为高.因此可将上述五项指标视为AFP(—)肝癌患者血清肿瘤标志物.此外,还发现肝癌患者血清两种结合蛋白的糖类含量高与血清a_1-AG。

水杨酸(SA)对果实成熟的影响

水杨酸是一种天然抑制剂，对植物有多种多样的作用，新近研究报道，它是乙烯生物合成的一种新的抑制剂。本文用水杨酸处理番茄、苹果、梨等果实，储藏在室温下，不时检查ＳＡ对果实贮存保鲜的影响。其结果表明ＳＡ处理的果实，ＰＧ活性比对照低，而硬度大，抗病力强。番茄，苹果和梨的无病好果率比对照果提高１０％以上。上述结果证明，用ＳＡ处理绿熟番茄及梨和苹果，能有效保存果实新鲜，增强抗病力和延长货架的寿命。

血清CA19-9、Hcy、CA50和SA联检对胰腺癌的诊断价值

目的:探讨了肿瘤标志物糖类抗原19-9(CA19-9),同型半胱氨酸(Hcy),糖类抗原50(CA50)和唾液酸(SA)联检对胰腺癌的临床评价。方法:应用放免法、免疫法和生化法对32例胰腺癌患者进行了血清CA19-9、Hcy、CA50和SA检测,并与35名正常健康人作比较。结果:以单一指标阳性作为诊断标准,CA19-9、Hcy、CA50和SA对胰腺癌的敏感性分别为68.8%、59.4%、62.5%和46.9%,特异性分别为84.8%、80.6%、71.4%和67.2%,联检二项或二项以上阳性作为标准,本文患者诊断的灵敏度为96.9%,特异性为98.2%。结论:联检血清CA19-9、Hcy、CA50和SA对胰腺癌的辅助诊断有较高的临床实用价值。