内源性一氧化氮在呼吸系统感染性疾病中的作用

一氧化氮(NO)是结构简单、毒性高的小分子化合物,是机体合成并可作用于多种组织器官,导致一系列病理反应的活性氮介质,具有复杂的生物学效应。我们通过对小儿呼吸系统感染性疾病时一氧化氮(N0)的临床研究。

常见异常肉的检验

在肉类检疫过程中,检出的异常肉常见有以下几种:1 囊虫病肉 囊虫病多发生于猪,即人们常说的“米心猪肉”。猪肉的检疫部位主要为咬肌、深腰肌、膈肌,其它可检部位:心肌、肩胛外侧肌、股部内侧肌等。如感染强度大,囊虫寄生的多,则容易检出,切开肌肉,即可见到高粱米粒大的白色、圆形或椭圆形的囊虫;如感染强度小,寄生虫少,则不易检出。检疫时,要耐心,认真。切口平行,最少两刀;如果发现虫体粥样崩解。

Chemoselective Transfer Hydrogenation of Cinnamaldehyde over Activated Charcoal Supported Pt/Fe3O4 Catalyst

A variety of spherical and structured activated charcoal supported Pt/Fe3O4 composites with an average particle size of ~100 nm have been synthesized by a self-assembly method using the difference of reduction potential between Pt （Ⅳ） and Fe （Ⅱ） precursors as driving force. The formed Fe3O4 nanoparticles （NPs） effectively prevent the aggregation of Pt nanocrystallites and promote the dispersion of Pt NPs on the surface of catalyst, which will be favorable for the exposure of Pt active sites for high-efficient adsorption and contact of substrate and hydrogen donor. The electron-enrichment state of Pt NPs donated by Fe304 nanocrystallites is corroborated by XPS measurement, which is responsible for promoting and activating the terminal C=O bond of adsorbed substrate via a vertical configuration. The experimental results show that the activated charcoal supported Pt/Fe3O4 catalyst exhibits 94.8% selectivity towards cinnamyl alcohol by the transfer hydrogenation of einnamaldehyde with Pt loading of 2.46% under the optimum conditions of 120 ℃ for 6 h, and 2-propanol as a hydrogen donor. Additionally, the present study demonstrates that a high-efficient and recyclable catalyst can be rapidly separated from the mixture due to its natural magnetism upon the application of magnetic field.

日粮中添加饲用葡萄糖氧化酶对肉仔猪生长性能的影响

试验研究了日粮中添加饲用葡萄糖氧化酶对生长猪生产性能的影响。选择66头平均体重为17kg左右的三元杂交仔猪,按体重和性别随机分成2个处理组,每处理3个重复,对照组饲喂基础日粮,试验组饲喂在基础日粮中添加0.05%含45u/g的饲用葡萄糖氧化酶的日粮,进行为期40d的试验。结果表明,与对照组相比,日粮中添加饲用葡萄糖氧化酶的试验组,日增重提高7.03%(P<0.05),料重比降低2.75%(P<0.05),头均毛利润增加16.35元,增幅10.08%。说明日粮中添加饲用葡萄糖氧化酶可显著提高生长猪的生产性能。

Germination Characteristics and Secondary Metabolism Regulation of Scutellaria baicalensis Georgi Seeds under Different Temperatures

[Objective] To study the germination characteristics and secondary metabolism of Scutellaria baicalensis Georgi seeds under different temperatures.[Method]The activities of superoxide dismutase（SOD）and peroxidase（POD）were determined with lactoflavine-NBT method and guaiacol-colorimetry assay,respectively.The catalase（CAT）,ascorbate peroxidase（APX）,phenylalanine ammonia-lyase（PAL）and cinnamic acid 4-Hydroxylase（C4H）were determined with ultraviolet spectrophotometry.The secondary metabolites were detected by High Performance Liquid Chromatography（HPLC）.[Result]The germination percentage,germination potentiality and germination index were seriously affected by low or high temperature.The proper germination temperature was 20-25 ℃.The activities of SOD,POD and CAT were significantly decreased as comparison to suitable temperature.The activities of PAL and C4H were also significantly decreased as comparision to suitable temperature which was accordance to the secondary metabolites.There was a positive correlation between the flavonoids content and the PAL and C4H activity（r=0.956,r=0.951,P0.05）.[Conclusion]The quality of the skullcaps could be improved by improving the activity of PAL and C4H.The proper temperature for the seed germination and the formation of secondary metabolites was 20 ℃.

Efficient oxidation of cinnamon oil to natural benzaldehyde over β-cyclodextrin-functionalized MWCNTs

We have designed and prepared β-cyclodextrin （β-CD）-functionalized multi-walled nanotubes （MWCNTs-g-CD） for the oxidation of cinnamon oil to natural benzaldehyde under aqueous condi- tions. The synergistic effect of combining MWCNTs with β-CD led to a remarkable increase in the performance of the MWCNTs-g-CD for the catalytic oxidation of cinnamaldehyde, which exhibited 95% cinnamaldehyde conversion and 85% selectivity to natural benzaldehyde with a short reaction time of 10 rain. The MWCNTs-g-CD also exhibited outstanding recyclability with good stability, showing no discernible decrease in their catalytic activity over five reaction cycles.

Changes of Primary and Secondary Metabolism during the Seed Germination of Scutellaria baicalensis Georgi

[Objective] To investigate the primary and secondary metabolism during the seed germination of Scutellaria baicalensis Georgi. [Method] The activities of SOD and POD were determined with lactoflavine-NBT method and guaiacol-colorimetry as- say, respectively. The activities of CAT, APX,PAL and C4H were determined with ultraviolet spectrophotometry. The contents of secondary metabolites were detected by High-performance Liquid Chromatography （HPLC）. [Result] The results indicate that the soluble sugar content decreased during the first 5 days and then increased when the cotyledons formed. The contents of PAL, C4H and CHS continuously in- creased at different stages during the seed germination process. The secondary metabolites also showed the consistent variation trend. In addition, the contents of secondary metabolites had significant positive correlation with the key enzyme activi- ty. [Conclusion] The formation of secondary metabolites is significantly positively cor- related with the key enzyme during the seed germination process. Therefore, the key enzyme activity can be enhanced by adopting appropriate measures to improve the secondary metabolites, thereby obtaining high-quality medicinal materials.

Use of Natural Antioxidants in Meat and Meat Products

Antioxidants are used to minimize lipid oxidation. Antioxidants can act as metal chelators and free radical or oxygen scavengers, which can slow the progression of lipid oxidation. Lipid oxidation may have negative effects on the quality of meat and meat products, causing changes in sensory attributes such as color, texture, odor and flavor, and nutritional quality. Several synthetic antioxidants have been used to successfully prevent lipid oxidation in the meat industry, but consumers are concerned about the health risks related to consumption of some synthetic antioxidants. Therefore, there has been a growing interest in natural antioxidants. Nowadays, compounds obtained from natural sources such as grains, oilseeds, spices, fruit and vegetables have been investigated to decrease the lipid oxidation. In this review, the potential effects of natural antioxidants were evaluated that are widely used in meat and meat products.

Role of nitric oxide in the impairment of circular muscle contractility of distended, uninflamed mid-colon in TNBS-induced acute distal colitis in rats

AIM： To evaluate the role of nitric oxide （NO） in the motor disorders of the dilated uninflamed mid-colon （DUMC） from trinitrobenzene sulfonic acid （TNBS）-induced acute distal colitis in rats. METHODS： Colitis was induced in male Sprague-Dawley rats by a single intracolonic administration of TNBS. Control rats received an enema of 0.9% saline. The rats were killed 48 h after TNBS or saline administration. Macroscopic and histologic lesions of the colon were evaluated. Myeloperoxidase （MPO） and nitric oxide synthase （NOS） activity were measured on the colonic tissue. In TNBS rats, we evaluated spontaneous and evoked contractile activity in circular muscle strips derived from DUMC in comparison to the same colonic segment of control rats, both in the presence and in the absence of a non-selective NOS isoforms inhibitor N-nitro-L- arginine （L-NNA）. Pharmacological characterization of electric field stimulation （EFS）-evoked contractile responses was also performed. RESULTS： In TNBS rats, the distal colon showed severe histological lesions and a high MPO activity, while the DUMC exhibited normal histology and MPO activity. Constitutive NOS activity was similar in TNBS and control rats, whereas inducible NOS activity was significantly increased only in the injured distal colon of TNBS rats. Isometrically recorded mechanical activity of circular muscle strips from DUMC of TNBS rats showed a marked reduction of the force and frequency of spontaneous contractions compared to controls, as well as of the contractile responses to a contracting stimulus. In the presence of L-NNA, the contractile activity and responses displayed a significantly greater enhancement compared to controls. The pharmacological characterization of EFS contractile responses showed that a cooperative-like interaction between cholinergic muscarinic and tachyldnergic neurokinin 1 and 2 receptors mediated transmission in DUMC of TNBS rats vs a simple additive interaction in controls. CONCLUSION： The results of this study show that, during TNBS-induced acute distal colitis, circular muscle intrinsic contractile mechanisms and possible enteric neural excitatory activity are inhibited in the distended uninflamed mid-colon. Suppression of NO synthesis markedly improves spontaneous and evokes muscle contractions, in spite of any evident change in local NO activity. 2005 The WJG Press and Elsevier Inc. All rights reserved

Influence of fasting on muscle composition and antioxidant defenses of market-size Sparus macrocephalus

The study was conducted to investigate fasting effects on flesh composition and antioxidant defenses of market-size Sparus macrocephalus. Two hundred fish (main initial weight 580 g) were divided into two groups (control and fasted) and reared in 6 cages. After two weeks of adaptation, group I fasted for 28 d; group II was fed normally as a control. In 3, 7, 14, 21 and 28 d, 6 fish per group were sampled for proximate flesh composition, liver antioxidant enzyme activities and malondialdehyde flesh content analyses. In fasted fish, the reduction of lipid content in muscle occurred after day 3, and, compared to controls, the content of protein decreased from day 14, the activities of liver antioxidative enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPX) increased from day 3, and flesh malondialdehyde levels increased from day 21. Flesh fat reduction shows that fasting may be used as a technique to reduce flesh lipid content in Sparus macrocephalus. However, considering flesh protein loss and the subsequent oxidative stress, the fasting technique should be used with precautions.

Antioxidative Effect of Fermented Soybeans Extract in Beef Patties with and without n-3 Fatty Acids

The objectives of the study were： a） to determine the optimal concentration of the extract that should be incorporated in meat products to maintain the lipid oxidative stability, and b） to verify if the extract exerted antioxidant activity even when these products were enriched with soybean oil （with fatty acids omega 3）. To carry out these aims, in the first instance the additive was incorporated into meat patties （elaborated with 80% beef and 20% fat plus 2% salt over total mass） at 0, 0.5, 1, 5 and 10 g/kg, respectively. The lipid oxidation was evaluated by measurement of peroxide value during 15 days at 8 ℃ and the results were expressed as reduction percentage of peroxidation （RP）. RP obtained were 55, 49, 73 and 59 respectively. As 5 g/kg was the optimum concentration of antioxidant, this was chosen to add to meat products enriched with soybean oil. In this case the RP obtained was 78%, indicating that the extract decreased lipid oxidation effectively.

β-Cyclodextrin Promoted Oxidation of Cinnamaldehyde to Natural Benzaldehyde in Water

A facile and efficient procedure has been developed systematically for the oxidative cleavage of cinna-maldehyde to benzaldehyde by sodium hypochlorite with water as the only solvent in the presence of β-cyclodextrin （abbreviated as β-CD）. Different factors influencing cinnamaldehyde oxidation e.g. reaction temperature, the amount of catalyst and oxidant, have been investigated. The yield of benzaldehyde reaches 76% under the optimum conditions （333 K, 4 h, molar ratio of cinnamaldehyde to β-CD is 1：1）. Furthermore, a feasible reaction mecha-nism including the formation of benzaldehyde and the two main byproducts （phenylacetaldehyde and epoxide of cinnamaldehyde） has been proposed.

Surface titanium oxide loaded on a special alumina as high-performance catalyst for reduction of cinnamaldehyde by isopropanol

A nanocomposite catalyst with a nonstoichiometric titanium oxide loaded on a special nanotubular alumina(γ‐Al2O3‐nt)was developed and used to reduce cinnamaldehyde to cinnamyl alcohol with sacrificial isopropanol,i.e.,a Meerwein‐Ponndorf‐Verley type reaction.The deposition process produced a highly disperse layer of titanium oxide on the surface of aγ‐Al2O3‐nt support.After a reduction treatment,the as‐prepared TiOx/γ‐Al2O3‐nt was a highly efficient catalyst for the hydrogen transfer reaction between isopropanol and cinnamaldehyde.Selectivity for cinnamic alcohol was higher than99%and the conversion of cinnamaldehyde was higher than95%.The regular morphology of theγ‐Al2O3‐nt support with homogeneous surface sites and the uniformly dispersed titanium oxide featured a high concentration surface Ti(III)species.These factors contributed to the high performance of the TiOx/γ‐Al2O3‐nt catalyst.

Effects of Dietary Supplementation with Cysteamine on Performance, Carcass Characteristics, Meat Quality and Antioxidant Status in Finishing Pigs

The current study was to investigate the effects of cysteamine （CS） on carcass characteristics, meat quality, and antioxidant status in finishing pigs. A total of 24 crossbred （PIC variety） finishing pigs （60.05±1.24 kg, 12 gilts and 12 barrows） were assigned randomly to one of the three dietary groups, with four pens/group （one gilt and one barrow per pen）. Pigs were fed with a basal diet containing 0 （control）, 70, or 140 mg/kg CS for 47 days. The results indicated that dietary CS supplementation increased （P〈0.05） the average daily gain and feed intake with optimal responses occurring at 70 mg/kg. Dietary supplementation of CS increased （P〈0.05） the dressing percentage and lean percentage of finishing pigs with optimal responses occurring at 140 mg/kg. The CS supplementation, however, had no effect （P〉0.05） on meat quality. Dietary CS supplementation increased （P〈0.05） total antioxidant capacity （T-AOC） and decreased malondialdehyde （MDA） with optimal responses occurring at 70 mg/kg. CS supplementation at both 70 mg/kg and 140 mg/kg doses improved （P〈0.05） the muscle RNA/DNA ratio. Collectively, the results suggest dietary supplementation of 70 mg/kg CS could significantly improve growth performance and antioxidant status without adverse effects on the gastrointestinal tracts in finishing pigs while the 140 mg/kg CS supplementation improved the carcass quality. However, meat quality was not affected by CS supplementation.

Effects of α-tocopheryl acetate supplementation in preslaughter diet on antioxidant enzyme activities and fillet quality of commercial-size Sparus macrocephalus

This study examined the effects of dietary α-tocopheryl acetate supplementation on antioxidant enzyme activities and fillet quality in commercial-size Sparus macrocephalus. Three hundred fish [main initial weight （350±12） g] were divided into three groups （E250, E500 and El000） and reared in 9 cages. The fish were fed for 8 weeks with three diets containing different levels of dietary α-tocopheryl acetate （289, 553, 1069 mg/kg）. Over the experimental period, fish were fed to satiation and reached a final mean weight of （465±28） g without significant body weight difference and proximate composition difference. Fillet α-tocopherol was significantly （P〈0.05） different between groups, reaching levels of 14.2, 22.1, 30.9 pg/mg fillet for groups E250, E500 and El000, respectively. Total serum superoxide dismutase （SOD） activity increased significantly （P〈0.05） in fish fed the diets high in α-tocopheryl acetate, but serum glutathione peroxidase （GPX） activity was unaffected. In storage on ice, fillets of fish fed the diets high in α-tocopheryl acetate exhibited significantly lower （P〈0.05） levels of oxidation. These results suggested that increased dietary α-tocopheryl acetate could increase its flesh deposition, increase the activity of SOD and prevent lipid peroxidation ofSparus macrocephalus fillets in retail storage on ice.

Oleuropein from Olive Leaf Extract as Natural Antioxidant of Frozen Hamburger

Oxidation is one of the major causes of hamburger deterioration. Antioxidants are used to minimize oxidation process. There is a growing interest in the substitution of synthetic food antioxidants by natural ones from vegetable sources. In meat industry, sodium erythorbate is antioxidant that is usually used and is an example of chemical antioxidant. Effect of olive leaf extract rich in olenropein on the quality of frozen hamburger was investigated. The objective of this study was to evaluate the usage of oleuropein from olive leaf extract as natural antioxidant in frozen hamburger stored at -12 ℃ compared with sodium erythorbate. Results suggested that olive leaf extracts might be useful to the meat industry as an efficient alternative to synthetic antioxidants by retarding oxidation of hamburger compared with sodium erythorbate 0.5% of olenropein and 0.5% of sodium erythorbate are the best concentrations to be used in frozen hamburger.

Mitochondrial dysfunction and aging muscle

Mitochondrial dysfunction in aged skeletal muscle has been mainly attributable to mtDNA deletions, uncoupling in oxidative phosphorylation, leading to ATP deficit. Moreover, the accumulation of damaged mitochondria is associated with imperfect autophagocytosis and declined biogenesis of efficient mitochondria. Mitochondria-associated apoptotic signaling is involved in the loss of fibers and atrophy of the remaining fibers by ROS, TNF-α, and denervation, leading to sarcopenia. Current investigations have indicated that exercise, especially resistance exercise, has extensively preventive effects on sarcopenia. Whether caloric restriction in aged animals is suitable for aged people remains to be further clinlically experimented. Additionally, it will be interesting to develop effectively supplementary and alternative medical methods associated with Chinese tonifying herbs to prevent or reverse sarcopenia in the future because of their efficacy and less frequent side effects.

Low Pressure Cold Plasma as an Alternative Method for Black Pepper Sterilization

It was found out that spices straight from the package are not sterile. The only way to receive sterile spices is to use radiation technology which means to irradiate spices with ionizing radiation. However, this method is quite expensive and raises great resistance of public. And this is the reason why we are interested in implementing plasma technology. The first step of the research was to choose the most appropriate spice. The range of available spices is nearly unlimited, however, we took into account the following ones： sweet paprika, basil, rosemary, saffron, marjoram, thyme and black pepper. Finally, we chose black pepper because it is most often used by butchers to make meat products. It is also called the ＂King of Spices＂ or the ＂Black Gold＂. Black pepper is one of the most often used spices in the United States and in Europe. It is important to have sterile black pepper when we aim at ripening products for example ripening sausages or some kinds of cheeses. What is more, it was found out that black pepper has antimicrobial properties, antioxidant effects and also antipyretic and analgesic properties. The aim of the research was to receive sterile spices using low pressure cold plasma with oxygen, nitrogen, air, argon and hydrogen peroxide.

Role of PGC-1αin muscle function and aging

This article focuses on the current underlying of molecular mechanisms of the peroxisome proliferator-activated receptor-γ coactivator-1α （PGC-1α） mediated pathway and discuss possible therapeutic benefits of increased mitochondrial biogenesis in compensating for mitochondrial dysfunction and ameliorating aging and aging-related diseases. PGC-1α is the master transcription regulator that stimulates mitochondrial biogenesis, by upregulating nuclear respiratory factors and mitochondrial transcription factor A, leading to increased mitochondrial DNA replication and gene transcription. PGC-1α also regulates cellular oxidant-antioxidant homeostasis by stimulating the gene expression of superoxide dismutase-2, catalase, glutathione peroxidase 1, and uncoupling protein. Recent reports from muscle-specific PGC-1α overexpression underline the benefit of PGC-1α in muscle atrophy and sarcopenia, during which PGC-1α enhanced mitochondrial biogenic pathway and reduced oxidative damage. Thus, PGC-1α seems to have a protective role against aging associated skeletal muscle deterioration.