Inducible nitric oxide synthase-derived nitric oxide regulates germinal vesicle breakdown and first polar body emission in the mouse oocyte

The present study investigated the subcellular localization of inducible nitric oxide synthase (iNOS) during mouse oocyte meiotic maturation and fertilization using confocal microscopy, and further studied the roles of iNOS-derived NO in oocyte maturation by using an iNOS-specific inhibitor aminoguanidine (AG) and iNOS antibody microinjection. In germinal vesicle-stage oocytes, iNOS immunoreactivity was mainly localized in the germinal vesicle. Shortly after germinal vesicle breakdown, the iNOS immunoreactivity accumulated around the condensed chromosomes. At metaphase I and metaphase II, with the organization of chromosomes to the equatorial plate, iNOS immunoreactivity was concentrated around the aligned chromosomes, putatively the position of the metaphase spindle. The accumulation of iNOS immunoreactivity could not be detected at anaphase I and anaphase II. However, at telophase I and telophase II, the staining of iNOS was concentrated in the region between the separating chromosomes/chromatids. Furthermore, the staining of iNOS also accumulated in the male and female pronuclei in fertilized eggs. Germinal vesicle breakdown and the first polar body emission of the oocytes were significantly blocked by the iNOS-specific inhibitor AG in a dose-dependent manner. The germinal vesicle breakdown in oocytes injected with iNOS antibody was also inhibited. We found that the phosphorylation of mitogen-activated protein kinase in oocytes after germinal vesicle breakdown was inhibited by AG treatment. The control oocytes extruded a normal first polar body, while the AG-treated oocytes exhibited an elongated protrusion or no elongated protrusion. The results of confocal microscopy showed that the AG-treated oocytes were arrested at anaphase I-telophase I. Our results suggest that the iNOS-derived NO pathway plays important roles in mouse oocyte meiotic maturation, especially in germinal vesicle breakdown and the anaphase-telophase transition.     

Plant oil bioconversion into increase biological activity through lipases derived from wastes

The aim of this study was to show that abundant and inexpensive plant oils can be biotransformed to increase biological activity (antioxidant, antimicrobial and cytotoxicity) through hydrolysis reaction catalysed by lipases. We tested homemade and commercial lipases through the biotransformation of nine different plant oils in forty different combinations. First, the chemical composition of the samples was investigated. Thereafter, biological tests were conducted to assess the antioxidant and antimicrobial activity of the sampled biotransformation products, as well as analyzed their influence on the viability of healthy and cancer cells. Summarising, sunflower, corn and olive oils modified by orange waste-obtained lipases presented the most promising results, reaching up to 90% of antioxidant activity increase and significant growth inhibition of bacteria colonies belonging to genera Escherichia, Listeria, Staphylococcus, Pseudomonas and Salmonella. In addition, those compounds affected human oral squamous carcinoma cells. The bioconversion of plant oils through lipases improves their biological properties and might be an option for biotechnological application.     

The toxicology of nitrate,nitrite and n-nitroso compounds

Nitrate is essentially non-toxic to mammals but it can be reduced to nitrite either in improperly stored food, in the rumen of cattle, in the gastrointestinal tract of the human infant, and by the microflora of the human mouth. The nitrite from these and other sources, including that purposely added to food, presents a toxic hazard both because of the direct toxicity of nitrite, and by the formation of carcinogenic N-nitroso compound by reaction with amino compounds. Administration of toxic amounts of nitrite induces methaemoglobinaemia. The nature of this disease, its importance in human medicine and the reason for the particular sensitivity of the infant, are briefly discussed. The carcinogenic properties of N-nitroso compounds are described. These compounds have been found in the environment and may be formed in the stomach from amines and nitrite. Our knowledge of the amount of N-nitroso compounds to which man is exposed, is continually increasing but with the lack of epidemiologic evidence, the assessment of the significance to man of these traces of N-nitroso compounds depends upon the interpretation of animal experiments and their extrapolation to man. This extrapolation would be more certain if there were a more clear understanding of the factors determining tissue selectivity by carcinogens and tissue sensitivity, and of the mechanism of cumulation of carcinogenic doses and of synergism between carcinogens. Recent experiments suggest that there may soon be a significant breakthrough in the understanding of this. These experiments are briefly discussed.     

The role of nitric oxide on matrix metalloproteinase 2 (MMP2) and MMP9 in placenta and fetus from diabetic rats

Matrix metalloproteinases (MMPs) play an important role in tissue remodeling that accompanies the rapid growth, differentiation, and structural changes of the placenta and several fetal organs. In the present study, we investigated whether the diabetic maternal environment may alter the regulatory homeostasis exerted by nitric oxide (NO) on MMPs activity in the feto-placental unit from rats at midgestation. We found that NADPH-diaphorase activity, which reflects the distribution and activity of NO synthases (NOS), was increased in both placenta and fetuses from diabetic rats when compared with controls. In addition, while a NO donor enhanced MMP2 and MMP9 activities, a NOS inhibitor reduced these activities in the maternal side of the placenta from control rats. This regulatory effect of NO was only observed on MMP9 in the diabetic group. On the other hand, the NO donor did not modify MMP2 and MMP9 activities, while the NOS inhibitor reduced MMP9 activity in the fetal side of both control and diabetic placentas. In the fetuses, MMP2 was enhanced by the NO donor and reduced by the NO inhibitor in both fetuses from control and diabetic rats. Overall, this study demonstrates that NO is able to modulate the activation of MMPs in the feto-placental unit, and provides supportive evidence that increased NOS activity leads to NO overproduction in the feto-placental unit from diabetic rats, an alteration closely related to the observed MMPs dysregulation that may have profound implications in the formation and function of the placenta and the fetal organs.     

Characteristic odour compounds in shochu derived from rice koji

Shochu, a traditional Japanese distilled liquor, makes use of rice koji, which is koji mould grown on rice grain. Rice koji is an essential ingredient of Japanese liquors such as shochu, and it plays a role as a source of the enzyme to degrade starch. However, there has been no research on the effect of rice koji on the flavour of shochu. Therefore, in this study, the volatile compounds in shochu derived from rice koji were investigated. Two shochu samples were prepared to assess the contribution of rice koji to the flavour. One shochu sample was prepared from rice koji, yeast and water (rice koji‐shochu). The other shochu sample was obtained from steamed rice and various enzymes instead of rice koji (enzyme‐shochu), along with yeast and water. The volatile compounds were analysed by gas chromatography–mass spectrometry (GC‐MS) and GC‐MS/olfactometry with aroma extract dilution analysis. The results showed that enzyme‐shochu had a higher flavour dilution value of dimethyl trisulphide and hexanal, whereas rice koji‐shochu had a higher flavour dilution value of some ester compounds that imparted aromatic odours such as fruity. Some unknown peaks representing compounds that impart characteristic odours such as soda, potato, lavender, and tea‐like were specifically detected in rice koji‐shochu. The concentrations and calculated odour active values of 14 compounds were measured. These results showed that isovaleraldehyde, ethyl caprylate, ethyl caproate and ethyl 2‐methylbutyrate played an important role in imparting the specific odour of rice koji‐shochu. Copyright © 2016 The Institute of Brewing & Distilling     

Antimicrobial activity of sulfur compounds derived from cabbage.

Selected sulfur compounds found in cabbage and its fermentation product, sauerkraut, were tested for minimum inhibitory concentration (MIC) against growth of 15 species of bacteria and 4 species of yeasts. S-Methyl-L-cysteine sulfoxide, sinigrin, and dimethyl sulfide at 500 ppm were not inhibitory to any of the bacteria and yeasts tested. Dimethyl disulfide at 500 ppm retarded some, but did not prevent growth of any of the test microorganisms. Dimethyl trisulfide had an MIC to bacteria of 200 ppm and to yeast of 20 ppm. Methyl methanethiosulfinate had an MIC between 50 and 200 ppm for all bacteria, and between 6 and 10 ppm for all yeasts tested. Methyl methanethiosulfonate had an MIC between 20 and 100 ppm for bacteria and between 50 and 500 ppm for yeasts. Allyl isothiocyanate had an MIC between 50 and 500 ppm for bacteria and between 1 and 4 ppm for yeasts. Methyl methanethiosulfinate was 10 to 100 times more inhibitory against Listeria monocytogenes at pH values of 5, 6, and 7 and was much less influenced by pH than was sodium benzoate.     

微波消解钴-丁二酮肟-亚硝酸钠极谱波测定猪肝中痕量钴

目的:研究钴(Ⅱ)-丁二酮肟(H2D)络合极谱波的性质;方法:在pH为9的氨性环境中,0.2 moL/L亚硝酸钠存在下,钴(Ⅱ)与丁二酮肟(H2D)络合反应,在-1.30 V(VsSCE)处产生灵敏的极谱波,讨论该络合物的电极反应机理,建立测定痕量钴的方法;结果:钴(Ⅱ)在0.004～0.10μg/mL内符合线性范围,检出限(3σ)为1.2×10-3μg/mL,电活性络合物组成为钴(Ⅱ)∶(H2D)=1∶1;结论:该法可用于猪肝中痕量钴的测定,分析结果的相对标准偏差小于2.8%.回收率在97～103%,结果满意.     

Genetic parameters derived from using a biological model of lactation on records of commercial dairy cows

The object of this study was to investigate the genetics of lactation curve parameters derived from a biological model of lactation and the relationships among them. This biological model fitted 2 logistic curves to mimic the initial increase in milk secretory cell numbers in early lactation and the progression of apoptosis in late lactation. Records from 82,255 Holstein-Friesian heifers from commercial dairy herds in the United Kingdom, recorded from 1994 to 2003, were analyzed. The heritabilities of 2 lactation curve parameters, maximum secretion potential and relative cell death rate, were 0.27 and 0.08 respectively. Maximum secretion potential was highly genetically correlated with peak yield (0.99), and relative cell death rate was highly correlated with persistency of lactation (0.84). Heritability values for the traits analyzed showed a characteristic pattern. Total milk yield traits, maximum secretion potential, and peak yield had similar and moderate heritabilities (∼0.3). Traits associated with late lactation had lower heritability values (∼0.1), whereas day of peak yield and early lactation traits had little genetic variation. The permanent environmental variance of the various traits ranged from 0.08 to 0.26 of the phenotypic variance. Parameters from the 2 logistic curves were not highly correlated, suggesting that selection programs could be devised to exploit genetic variation in both aspects of lactation independently.     

Electrochemical enhancement of nitric oxide removal from simulated lean-burn engine exhaust via solid oxide fuel cells

A solid oxide fuel cell (SOFC) unit is constructed with Ni-YSZ as the anode, YSZ as the electrolyte, and La(0.6)Sr(0.4)CoO(3)-Ce(0.9)Gd(0.1)O(1.95) as the cathode. The SOFC operation is performed at 600 °C with a cathode gas simulating the lean-burn engine exhaust and at various fixed voltage, at open-circuit voltage, and with an inert gas flowing over the anode side, respectively. Electrochemical enhancement of NO decomposition occurs when an operating voltage is generated; higher O(2) concentration leads to higher enhancement. Smaller NO concentration results in larger NO conversion. Higher operating voltage and higher O(2) concentration can lead to both higher NO conversion and lower fuel consumption. The molar rate of the consumption of the anode fuel can be very much smaller than that of NO to N(2) conversion. This makes the anode fuel consumed in the SOFC-DeNO(x) process to be much less than the equivalent amount of ammonia consumed in the urea-based selective catalytic reduction process. Additionally, the NO conversion increases with the addition of propylene and SO(2) into the cathode gas. These are beneficial for the application of the SOFC-DeNO(x) technology on treating diesel and other lean-burn engine exhausts.     

Inhibition of germinal vesicle breakdown by antioxidants and the roles of signaling pathways related to nitric oxide and cGMP during meiotic resumption in oocytes of a marine worm

In mammalian oocytes, cAMP elevations prevent the resumption of meiotic maturation and thereby block nuclear disassembly (germinal vesicle breakdown (GVBD)), whereas nitric oxide (NO) and its downstream mediator cGMP can either inhibit or induce GVBD. Alternatively, some invertebrate oocytes use cAMP to stimulate, rather than inhibit, GVBD, and in such cases, the effects of NO/cGMP signaling on GVBD remain unknown. Moreover, potential interactions between NO/cGMP and AMP-activated kinase (AMPK) have not been assessed during GVBD. Thus, this study analyzed intraoocytic signaling pathways related to NO/cGMP in a marine nemertean worm that uses cAMP to induce GVBD. For such tests, follicle-free nemertean oocytes were stimulated to mature by seawater (SW) and cAMP elevators. Based on immunoblots and NO assays of maturing oocytes, SW triggered AMPK deactivation, NO synthase (NOS) phosphorylation, and an NO elevation. Accordingly, SW-induced GVBD was blocked by treatments involving the AMPK agonist AICAR, antioxidants, the NO scavenger carboxy-PTIO, NOS inhibitors, and cGMP antagonists that target the NO-stimulated enzyme, soluble guanylate cyclase (sGC). Conversely, SW solutions combining NO/cGMP antagonists with a cAMP elevator restored GVBD. Similarly, AICAR plus a cAMP-elevating drug reestablished GVBD while deactivating AMPK and phosphorylating NOS. Furthermore, sGC stimulators and 8-Br-cGMP triggered GVBD. Such novel results indicate that NO/cGMP signaling can upregulate SW-induced GVBD and that cAMP-elevating drugs restore GVBD by overriding the inhibition of various NO/cGMP downregulators, including AMPK. Moreover, considering the opposite effects of intraoocytic cAMP in nemerteans vs mammals, these data coincide with previous reports that NO/cGMP signaling blocks GVBD in rats.     

Emission and control of nitrous oxide from a biological wastewater treatment system with intermittent aeration

Nitrous oxide (N2O) can be emitted as a by-product of the process of nitrogen removal from wastewater. Two methods of complete denitrification and media application were studied in lab-scale intermittent aeration reactors fed with domestic wastewater to refine methods of controlling the N2O emission rate. A study on cyclic patterns showed that the highest N2O emission rate was at the beginning of the aerobic phase rather than the anoxic phase. This was probably because the nitrifying bacteria had accumulated nitrite nitrogen (NO2-) under low DO conditions. Methanol as an external carbon source was added during the anoxic phase to reduce nitrate nitrogen (NO3-) when denitrification was completed. The N2O emission rates in both the aerobic and anoxic phases were significantly influenced by residual NO3-, increasing monotonically as the concentration of NO3- in the reactor increased. Over 95% of average N2O emissions in both the aerobic and anoxic phases were prevented when methanol was added. The biofilm reactor showed similar patterns to those of the non-biofilm reactor in track behavior, but the former was more effective in the reduction of N2O emissions.     

High-temperature adsorption of carbon dioxide on mixed oxides derived from hydrotalcite-like compounds

Various XnY(3-n)Al-hydrotalcite-like compounds (HTlcs) were synthesized by the constant pH coprecipitation method with the (X2+ + Y2+)/Al3+ molar ratio fixed at 3.0. Well-mixed oxides Xn,Y(3-n)AlO were derived from corresponding HTlcs precursors upon calcination. Physicochemical characterization with X-ray diffraction analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis (TGA), and the Brunauer-Emmett-Teller equation indicates that the derived oxides are of either periclase or spinel phase, with an interparticle pore diameter of 9.6-15.4 nm. These oxides generally show a high CO2 adsorption capability at 350 degrees C. For example, CaCoAlO captures 1.39 mmol/g of CO2 (i.e., 6.12 wt %) from a gas mixture (8% CO2 in N2) at 350 degrees C and 1 atm in a fixed-bed reactor within 20 min. All other mixed oxides adsorb 0.87-1.28 mmol/g (3.83-5.63 wt %) of CO2. Therefore, these mixed oxides are potential cost-effective CO2 sorbents for environmental remediation. In addition, the CO2 adsorption behavior is well-described with the deactivation model. The species of CO2 formed on the sorbents are various carbonates, as revealed by in situ IR spectra as well as TGA.     

Phytochemical compounds and biological activity in Asparagus roots: a review

Asparagus roots (AR) contain many bioactive compounds and their use in Chinese and Indian traditional medicines is well documented. Both in vitro and in vivo studies have indicated AR extracts act as antidiabetic, antioxidant and hypolipidaemic and depict anti-inflammatory, antibacterial, antiviral, anticarcinogenic activities and also improve cardiovascular and oral health. The physiological effects against wide range of pathologies are due to the wide range of phytochemicals found in AR including polyphenols, saponins and polysaccharides. The aim of this review is to present an overview of the functional, medical and physiological properties of AR bioactives. This review considers the roots of several asparagus species and provides up-to-date information on Asparagus officinalis that has not been extensively reviewed before.     

泡菜中降解亚硝酸盐乳酸菌的筛选及生物学特性研究

为降低泡菜发酵过程中亚硝酸盐含量,从泡菜中筛选出6株降解亚硝酸盐的乳酸菌。根据培养特征、菌体特征和16S r DNA同源比对分析,JYF1、JYF2、JYF5和JYF6鉴定为植物乳杆菌; JYF3和JYF4鉴定为发酵乳杆菌,选取JYF2和JYF3研究其生物学特性。结果表明:JYF2和JYF3发酵的泡菜最终p H值为3,自然发酵的最终p H值为3. 5;泡菜发酵至第8天,JYF2和JYF3发酵的泡菜亚硝酸盐含量分别为1. 8和2 mg/kg,低于自然发酵组6. 3 mg/kg; JYF2和JYF3在p H 3～4时,存活率> 60%;胆盐质量浓度在0. 01～0. 03 g/L时,JYF2和JYF3的存活率在50%以上; JYF2和JYF3对革兰氏阳性菌的抑制作用大于革兰氏阴性菌; JYF2和JYF3对不同抗生素有不同的敏感性。本研究筛选的JYF2和JYF3具有良好的生物学特性,可为生产低亚硝酸盐泡菜提供优良发酵菌株。     

乌贼墨抑制海洋鱼体腐败菌活性成分的分离

对乌贼墨中抑制海洋鱼体腐败菌活性成分进行了分离,并初步探讨了抑菌成分的理化特性。结果表明:乌贼墨粗提物经DEAE-纤维素和Sepharose 4B分离后获得具有较高活性的抑菌活性物质,分子量约为83589u,对四种海洋鱼体腐败菌（气单胞菌、黄杆菌、芽孢杆菌、肠杆菌）的平均抑菌率为62.36%。经紫外扫描（UV）和红外光谱（IR）分析,抑菌物质的主要成分为多糖。      

Phenylpropanoids from red kohlrabi sprouts inhibits nitric oxide production in RAW 264.7 macrophage cells

The sprouts of red kohlrabi (Brassica oleracea var. gongylodes) were extracted with methanol, and the concentrated extracts were successively partitioned with ethyl acetate, n-butyl alcohol (n-BuOH), and H₂O. From the n-BuOH fraction, four phenylpropanoids were isolated through repeated silica gel and ODS column chromatographies. On the basis of physico-chemical and spectroscopic data including NMR, MS, and IR, the isolated compounds were identified as 3-(3,4,5-trimethoxyphenyl)-2E-propenoic acid methyl ester (1), (E)-sinapic acid methyl ester (2), (E)-sinapoyl glucoside (3), and lawsoniaside B (4). Moreover, the compounds dose-dependently inhibited NO production in RAW 264.7 cells with IC₅₀ values of 41.22 (1), 38.32 (3), and 22.65 (4) μM, respectively. With further studies, these compounds may be potentially useful in developing new anti-inflammatory agents.     

The effects of lactate on nitrosylmyoglobin formation from nitrite and metmyoglobin in a cured meat system

Two experiments were conducted to determine the effects of lactate on nitrite during meat curing. In the first experiment, using a model system, eight reaction components including nitrite and lactate, were used to assess the effect of each component on metmyoglobin reducing activity by excluding one component at a time. Excluding lactate, nicotinamide adenine dinucleotide (NAD), l-lactate dehydrogenase (LDH) or phenazine methosulfate (PMS) resulted in no reducing activity. A second experiment, utilising a meat mixture, investigated the effects of lactate (0%, 2%, 4% or 6%), nitrite (0 or 156 ppm), and packaging (oxygen-permeable or vacuum) on residual nitrite, meat colour and pH. Addition of lactate reduced residual nitrite in the meat mixtures. Both experiments support the hypothesis that lactate generates NADH which then reduces metmyoglobin to deoxymyoglobin. The resulting greater concentration of reduced myoglobin subsequently reacted with nitrite to produce more nitric oxide, reducing nitrite concentration and accelerating curing reactions.