Preparation,characterization and in vitro anticoagulant activity of corn stover xylan sulfates

A new anticoagulant agent was prepared by introducing sulfate groups into corn stover xylan through homogeneous reactions. Three organic solvents, N, N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO) and formamide (FA), were adopted as reaction media, with the assistance of LiCl. Structural characterization by FT-IR and ¹³CNMR showed that xylan sulfate (XS) could be successfully synthesized with SO₃?Pyridine (SO₃?Py) complexes sulfation reagent in the three media. The effect of sulfation temperature, sulfation time, media type and molar ratio of ?SO₃/?OH on the degree of substitution (DS) and degree of the polymerization (DP) were studied. DMF/LiCl were more effective than DMSO/LiCl and FA/LiCl in preparation of xylan sulfate with high DS. The optimal conditions for sulfation were obtained when SO₃?Py complex was added to DMF/LiCl with ?SO₃/?OH ratio of 1.5:1 and maintained at 50 °C for 3 h. Degree of polymerization of xylan was decreased during the sulfation process and DMF/LiCl offered the least xylan degradation as compared with DMSO/LiCl or FA/LiCl. Anticoagulant activities of the resultant xylan sulfates with different DS were evaluated by using activated partial thromboplastin time (APTT), thrombin time (TT), and prothrombin time (PT). Results indicated that the introducing of sulfate groups into xylan did endow the polysaccharides with anticoagulant activity. The APTT and TT of XS with DS of 1.20 reached 141 and 45.3 s at a dosage of 20 μg/mL, while the APTT and TT values for the blank sample were only 35.5 and 15.6 s. Furthermore, coagulation time was prolonged with the increase of DS and the concentration of XS. Our findings provide new insights into the value-added utilization of agricultural biomass.     

Documentation of Ultrastructural Changes in Nucleus and Microvilli by Fish Oil in Experimental Colon Carcinogenesis

Fish oil (FO) exerts a chemopreventive effect by regulating apoptosis in colon carcinogenesis. The present study reports the ultrastructural changes in various organelles on supplementation of FO in experimental colon carcinogenesis. The carcinogen treatment led to abnormal nuclear shape and alteration in microvilli number indicating cancer establishment. On the other hand, different ratios of FO and corn oil increased chromatin condensation along with an extensive loss of microvilli in a dose- and time-dependent manner which depicts an increase in apoptosis. The associated ultrastuctural alterations support the facilitation of apoptosis by FO as a mechanism for its beneficial effect in colon carcinogenesis.     

Immunogenicity study of plant-made oral subunit vaccine against porcine reproductive and respiratory syndrome virus (PRRSV)

Currently, killed-virus and modified-live PRRSV vaccines are used to control porcine reproductive and respiratory syndrome disease (PRRS). However, very limited efficacy of killed-virus vaccines and serious safety concerns for modified-live virus vaccines demand the development of novel PRRSV vaccines. In this report, we investigated the possibility of using transgenic plants as a cost-effective and scalable system for production and delivery of a viral protein as an oral subunit vaccine against PRRSV. Corn calli were genetically engineered to produce PRRSV viral envelope-associated M protein. Both serum and intestine mucosal antigen-specific antibodies were induced by oral administration of the transgenic plant tissues to mice. In addition, serum and mucosal antibodies showed virus neutralization activity. The neutralization antibody titers after the final boost reached 6.7 in serum and 3.7 in fecal extracts, respectively. A PRRSV-specific IFN-γ response was also detected in splenocytes of vaccinated animals. These results demonstrate that transgenic corn plants are an efficient subunit vaccine production and oral delivery system for generation of both systemic and mucosal immune responses against PRRSV.     

Acute effects of fructose consumption on uric acid and plasma lipids in patients with impaired renal function

Objective

Metabolic disturbances are common in patients with renal function impairment and are related to high rates of cardiovascular incidents and mortality. Kidney transplantation leads to improved survival but may lead to additional metabolic alterations caused by immunosuppressive drugs and improved nutrition.

Materials and methods

The short-term effect of oral fructose load on serum uric acid (UA), plasma lipids, and blood pressure (BP) was studied in 85 patients with chronic kidney disease (CKD) and impairment of renal function (glomerular filtration rate 50–65 ml/min per 1.73 m²), comprising 55 renal transplant recipients (RTR) treated with standard triple immunosuppressive therapy including a calcineurin inhibitor (CNI) cyclosporine A (CsA) or tacrolimus (Tac) and 30 non-transplanted patients with CKD. Both non-transplanted CKD patients and RTR had stable renal function and a comparable degree of kidney dysfunction. All subjects received orally 70 g of fructose dissolved in 200 ml of water. Serum UA, lipids, and blood pressure were measured at baseline and 60, 120, 180, and 240 minutes after fructose administration.

Results

There was a significant increase of serum UA concentration (p < 0.001) in both CKD patients and RTR – CsA- or Tac-treated patients comparable in the latter. Total cholesterol (TC), LDL, and HDL cholesterol significantly decreased and serum triglycerides (TG) markedly increased in RTR, whereas in CKD patients all serum lipid fractions increased. Blood pressure was unaffected by fructose intake.

Conclusion

Both non-transplanted and transplanted patients with mild renal function impairment show similar acute purine metabolic disturbances following oral administration of fructose but in the latter dietary fructose may induce a smaller hyperlipidemic response.     

玉米活性肽对辐射防护作用的研究

目的:观察玉米活性肽对X线照射正常机体造血功能的保护作用。方法:观察20只NIH小鼠按对照组(正常饲料)、给药组(含玉米活性肽30g/100g饲料)进行照射3d后血象的改变(能量6mVX线,剂量6Gy,面积30 cm×30 cm),和2周后血象的恢复情况。结果:放疗后与放疗前比较,3d后对照组与给药组的白细胞均明放疗后与放疗前比较,3d后对照组与给药组的白细胞均明显降低,并且MDA升高,SOD活性下降。2周后与放疗前比较,SOD活性恢复,MDA降低,给药组与对照组白细胞数得到恢复,给药组白细胞增加明显,与对照组差异显著(P<0.05)。血色素水平于照后3d变化不大,14d后降低明显。试验组与对照组无差别。血小板在照后3d时无明显变化,但2周后下降明显,给药组高于对照组(P<0.05)。结论:玉米活性肽可能通过提高小鼠抗氧化水平,对X线照射小鼠造血功能具有防护作用。     

Antiatherogenic action of corn oil in experimental atherosclerosis

Research Institute of Physicochemical Medicine, Ministry of Health, Moscow. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 113, No. 5, pp. 476–478, May, 1992.     

High dietary fructose intake: Sweet or bitter life?

Epidemiological data show that the consumption of added sugars as ingredients in processed or prepared foods and caloric beverages has dramatically increased. Fructose and fructose-based sweeteners are the most commonly added sugars and high-fructose corn syrup (HFCS-55: 55% fructose, 42% glucose and 3% higher saccharides) accounts for over 40% of all added caloric sweeteners. Concerns regarding the health risk of added sugar follow the demonstration that the consumption of foods and beverages high in sugars is associated with an increased prevalence of obesity, insulin resistance, dyslipidemia and, more recently, ischemic heart and kidney diseases. The molecular mechanism(s) underlying the detrimental effects of sugar are not completely understood and their elucidation is critical to provide new insights on the health risk of fructose-based sweeteners. A better understanding of the key role of fructose overconsumption in the development of metabolic disorders may contribute to planning new strategies for preventing deleterious dietary behaviors from becoming established and, thus, curbing the rise in the number of insulin-resistant, obese and diabetic populations worldwide.