Glycoprotein components in the serum of patients with cancer breast

The levels of total sialic acid, lipid bound sialic acid and fucose were estimated in the sera of patients with benign and malignant tumours of breast. An increase was noted in all the three parameters, with a more marked increase in malignancy, when compared with benign and controls. Consequent to surgery, there was an elevation in the serum levels of the above parameters than the values prior to surgery and a decline was noted two months after surgery although none of the values reached the normal range. These results suggest a close association of the glycoproteins with the tumour burden and further signify their role in early detection and staging of cancer breast.     

酸活化对膨润土比表面积和孔径的影响研究

分别用质量分数为5%、10%、15%、20%、25%和30%的硫酸溶液对黑山膨润土进行酸化改性,用乙二醇乙醚吸附法和氮气吸附法对黑山膨润土及其酸化土的比表面积和孔体积进行分析。结果表明:膨润土酸化改性后,随着硫酸质量分数的增加,外表面积增加不明显,内表面积及总表面积减小;半径大于1nm的孔的体积明显增加,半径小于1nm的孔的体积逐渐减小直至为0。可见,本实验条件下膨润土酸化改性后性质的变化,并不是主要由表面积增加引起的,而是由有效孔(半径>1nm)的大量增加引起的。     

毛细管电泳法测定苹果中维生素含量

采用毛细管区带电泳法测定了5种苹果中维生素C和烟酸的含量。在20mmol/L硼砂和20%乙腈的混合缓冲体系(pH 8.5)中,两种维生素在15min内较好地得到分离。维生素C和烟酸的迁移时间和峰面积的相对标准偏差分别为5.43%和2.35%、6.24%和2.49%。质量浓度在0.007 81～1 000mg/L范围内线性相关系数分别为0.9964、0.9945。该方法简单、准确,可作为果实品质测定的一种方法。     

Effects of polyurethane matrices on fungal tannase and gallic acid production under solid state culture

The influence of the physical structure of polyurethane matrix as a support in a solid state culture in tannase production and gallic acid accumulation by Aspergillus niger Aa-20 was evaluated. Three different polyurethane matrices were used as the support: continuous, semi-discontinuous and discontinuous. The highest tannase production at 2479.59 U/L during the first 12 h of culture was obtained using the discontinuous matrix. The gallic acid was accumulated at 7.64 g/L at the discontinuous matrix. The results show that the discontinuous matrix of polyurethane is better for tannase production and gallic acid accumulation in a solid state culture bioprocess than the continuous and semi-discontinuous matrices. Project supported by the Agricultural, Livestock and Fishing Department (SAGARPA, No. 12385) and the National Forest Commission (CONAFOR, No. 2004-C01-13), and the Council of Science and Technology, Mexico     

A new linearly-combined bi-exponential model for kinetic analysis of the isometric relaxation process of <Emphasis Type="Italic">Bufo gastrocnemius</Emphasis> under electric stimulation in vitro

There was a slow-relaxing tail of skeletal muscles in vitro upon the inhibition of Ca^2＋-pump by cyclopiazonic acid （CPA）. Herein, a new linearly-combined bi-exponential model to resolve this slow-relaxing tail from the fast-relaxing phase was investigated for kinetic analysis of the isometric relaxation process of Bufo gastrocnemius in vitro, in comparison to the single exponential model and the classical bi-exponential model. During repetitive stimulations at a 2-s interval by square pulses of a 2-ms duration at 12 V direct currency （DC）, the isometric tension of Bufo gastrocnemius was recorded at 100 Hz. The relaxation curve with tensions falling from 90% of the peak to the 15th datum before next stimulation was analyzed by three exponential models using a program in MATLAB 6.5. Both the goodness of fit and the distribution of the residuals for the best fitting supported the comparable validity of this new bi-exponential model for kinetic analysis of the relaxation process of the control muscles. After CPA treatment, however, this new bi-exponential model showed an obvious statistical superiority for kinetic analysis of the muscle relaxation process, and it gave the estimated rest tension consistent to that by experimentation, whereas both the classical bi-exponential model and the single exponential model gave biased rest tensions. Moreover, after the treatment of muscles by CPA, both the single exponential model and the classical bi-exponential model yielded lowered relaxation rates, nevertheless, this new bi-exponential model had relaxation rates of negligible changes except much higher rest tensions. These results suggest that this novel linearly-combined bi-exponential model is desirable for kinetic analysis of the relaxation process of muscles with altered Ca2^＋-pumping activity.     

两种体系中甘氨酸合铜配合物稳定常数的测定

采用pH电位滴定法研究了甘氨酸水溶液和甘氨酸钠水溶液两种体系中甘氨酸与铜离子间的配位作用,测定了两种体系中甘氨酸与铜配合物的逐级稳定常数;对影响测定准确度的原因进行了详细的分析,采用Origin 6.0计算机软件包来处理实验数据和作图。     

nano-Pt/GC电极的制备及对甲酸电催化氧化

应用循环伏安法制备了nano-Pt/GC修饰电极,优化了铂微粒在电极表面的沉积条件,并用扫描电子显微镜(SEM)和在硫酸中的循环伏安曲线对其进行了表征,结果表明铂微粒较为均匀地分散在玻碳电极表面,粒径约为140nm,电极具有很大的比表面积.实验研究表明nano-Pt/GC修饰电极对甲酸电氧化的催化性能明显好于铂片电极,在该电极上甲酸正向扫描和反向扫描时的氧化峰电流分别是铂片电极上的4.37倍和3.49倍,有效地提高了金属铂的利用率,玻碳电极上铂微粒的最佳沉积条件为循环次数为100次、沉积速度为5mV/s.     

Effect of dietary fatty acids on serum parameters, fatty acid compositions, and liver histology in Shaoxing laying ducks

The effects of different fatty acid (FA) contents in diet on serum parameters, FA compositions of eggs and meat, and liver morphological changes were studied in Shaoxing laying ducks. A total of 264 ducks at 17 weeks were fed a control diet or a diet containing 30 g/kg fish oil (FO), 25 g/kg sunflower oil (SO), or 30 g/kg palm oil with 20 g/kg beef tallow (PBO). Malondialdehyde (MDA) content in the liver and the serum of ducks fed the PBO diet was significantly (P<0.05) higher than that of ducks fed the other diets. Triglyceride (TG) and total cholesterol (TC) levels were significantly lower (P<0.05) in ducks fed the FO diet. Serum TC also was lower in ducks fed the SO diet. Superoxide dismutase (SOD) activity was also affected by diets. The contents of polyunsaturated FAs (PUFAs) in eggs and meat were significantly higher (P<0.001) in ducks fed the FO and SO diets than in ducks fed the control diet. The level of C22:6 (n-3) FA in ducks fed the FO diet was significantly higher than that in ducks fed the other diets. However, the conversion efficiency of the longer-chain C20:5 (n-3) FA was higher than that of C22:6 (n-3). Ducks fed the PBO diet exhibited lipid droplet accumulation in the liver. These results demonstrate that a diet enriched with different FAs has strong effects on serum lipid levels and the deposition of PUFAs into tissue lipids.     

Hyaluronic acid as a rescue therapy for trinitrobenzene sulfonic acid-induced colitis through Cox-2 and PGE2 in a Toll-like receptor 4-dependent way

We hypothesized whether systemic administration of high-molecular-weight hyaluronic acid (HMW HA) could rescue trinitrobenzene sulfonic acid (TNBS)-induced colitis through Toll-like receptor 4 (TLR4) signal. C3H/HeN mice and C3H/HeJ mice were used. Mice were divided into four groups: control, 50% ethanol treatment group, TNBS treatment group, and TNBS plus HA treatment group. The weight changes, clinical scores, macroscopic scores, and histological scores were recorded. Cyclooxygenase 2 (Cox-2) and prostaglandin E₂ (PGE₂) expressions were measured both in colons and peritoneal macrophages from these mice. HA was a rescue therapy for the colitis induced by TNBS only in C3H/HeN mice. The clinical score, macroscopic score, and histological score were much lower in C3H/HeN mice receiving TNBS plus HA treatment. Cox-2 and PGE₂ expressions only increased in C3H/HeN mice. These Cox-2 expressing cells were macrophages. HA can also promote the production of Cox-2 and PGE₂ in peritoneal macrophages from C3H/HeN mice. Our data demonstrated that HMW HA can rescue TNBS-induced colitis through inducing Cox-2 and PGE₂ expressions in a TLR4-dependent way. Macrophages may be the effector cells of HMW HA.     

Production of conjugated linoleic acids by Lactobacillus plantarum strains isolated from naturally fermented Chinese pickles

Naturally fermented pickles harbour many lactic acid bacteria (LAB). Forty-three LAB strains with conjugated linoleic acid (CLA)-producing ability were isolated from three naturally fermented pickle brines. Of these isolates, lp15 identified as Lactobacillus plantarum by API 50 CHL system and full-length 16S rDNA sequence analysis exhibited the highest CLA-producing ability (26.1% conversion) at 48 h in de Man Rogosa Sharpe (MRS) broth in the presence of 100 μg/ml of linoleic acid (LA). Compared to other strains, L. plantarum strain lp15 showed the highest tolerance upon increased levels of LA in the medium, i.e., up to 600 μg/ml. This strain converted about 25% of LA into CLA isomers [predominantly cis-9, trans-11 CLA (9-CLA) and trans-10, cis-12 CLA (10-CLA)], of which 75% was 9-CLA. Interestingly, though the conversion rate of LA into CLA by lp15 remained stable between 100 to 600 μg/ml LA levels in the medium, it dropped sharply at 1000 μg/ml. Taken together, the lp15 strain displayed relatively high LA tolerance with higher conversion rate, which implies that this strain is a valuable candidate for enhancing the CLA content in food-sources like pickles.