Occurrence Of Lipids Research Articles

Effect of drying processes on the occurrence of lipid oxidation-derived 4-hydroxy-2-hexenal and 4-hydroxy-2-nonenal in Spanish mackerel (Scomberomorus niphonius).

In this study, dry-cured Spanish mackerel (Scomberomorus niphonius, DCSM) was prepared via three different methods (hot-air drying, cold-air drying, and sun drying). The content of 4-hydroxy-2-hexenal (HHE) and 4-hydroxy-2-nonenal (HNE) derived from lipid oxidation in whole processes was investigated by HPLC-MS/MS. The changes in fatty acid composition were detected by GC-MS, and the degree of lipid oxidation was evaluated by the levels of acid values (AV), peroxide values (POV), and thiobarbituric acid-reactive substances (TBARS). The results showed that the drying process significantly accelerated lipid oxidation in DCSM. The contents of HHE and HNE were significantly increased after processing. The content of HHE was higher by 18.44-, 13.45-, and 16.32-folds compared with that of HNE after three different processes, respectively. The HHE and HNE contents fluctuated upward during the hot-air and cold-air drying process. However, the contents of HHE and HNE increased time-dependent during the sun drying process, with the highest values of 86.33 ± 10.54 and 5.29 ± 0.54 mg/kg fish among the three different processes. Besides, there was a significant positive correlation between HHE contents and n-3 fatty acids content in hot-air drying and sun drying processes (Pearson's r=.991/.996), and HNE occurrence was closely related to n-6 fatty acid content in sun drying process (Pearson's r=.989). Regression analysis indicated that the content of HHE and TOTOXTBA values in DCSM showed good linear relationships (R 2 value=.907), which suggested that the content of HHE could be used to estimate the oxidative deterioration of dry-cured fish products.

Oxidative stress and genotoxicity assessment of silicon di oxide nanoparticle in snake headed murrel, Channa punctautus

Consequences of waterborne silicon di oxide nanoparticles (SiO2 NPs) on snake headed fish, Channa punctatus were investigated and analyzed for oxidative stress and genotoxicity in a long-term assay. Fish were divided into three groups: Group I (control), Group II and III considered as treated groups. Fish were exposed to 25% and 50% of LC50 value (60 and 120 mg/l of SiO2 NPs) at day 7,15,21,28 and 35. Fish exposed to higher concentrations of SiO2 NPs showed major alterations in oxidative stress markers. Significant alterations were noted in SOD, CAT, GST, GSH, GPx and GR in the gills, liver and kidney of fish of both treated groups. A significant increase of SOD, CAT, GST, GPx and GR in the gill, liver and kidney of fish was observed, whereas GSH showed significant decrease in all treated groups in all tissues. LPO was also estimated in gills, liver and kidney and elevation was noted. By standard genotoxicity test such as micronucleus test and comet assay, genetic damage (cytoplasmic, nuclear and DNA damage) was recorded which indicates significant toxicity of SiO2 NPs at higher concentrations. Significant changes in all parameters studied thus reflected an adverse influence of SiO2 Nps exposure on oxidative stress as well as genotoxicity of the fish. SiO2 Nps toxicity appeared to be dose and duration dependent. The presence of SiO2 Nps leads to an activation of the antioxidant defense system and the occurrence of lipid and genetic damage if antioxidant enzymes were unable to overcome oxidative stress.

Effect of oxidation and maillard reaction on color deterioration of ready-to-eat shrimps during storage

The mechanism of color deterioration in ready-to-eat (RTE) shrimps during storage was revealed for the first time. During storage, the appearance of the RTE shrimps gradually browned and blackened. Meanwhile, colorimeter analysis showed that the lightness decreased, but the redness and yellowness increased after storage. The peroxide and thiobarbituric acid value increased but the astaxanthin and phenol contents decreased after storage, indicating the occurrence of lipid and phenol oxidation. And the browning index, 5-hydroxymethylfurfural, pyrroles and pyrazine volatile compounds showed an upward trend after storage, indicating the occurrence of Maillard reaction. Correlation and principal component analysis showed that the composite effects of lipid oxidation, phenol oxidation, Maillard reaction and astaxanthin degradation led to the color deterioration of RTE shrimps, and the order of effect was Maillard reaction > lipid oxidation > phenol oxidation > astaxanthin degradation. Moreover, the lipid oxidation had a certain promoting effect on Maillard reaction and phenol oxidation.

Toxicity of Titanium Dioxide Nanoparticles Induced by Reactive Oxygen Species

Titanium dioxide nanoparticles (TiO2 NPs) are one of the most widely used types of nanoparticles which can be used in food additives and drugs. However, the safety of TiO2 NPs is still controversial and the biological mechanism of TiO2 NPs-induced toxicity is not clear yet. We reviewed the research about toxicity of TiO2 NPs induced by reactive oxygen species (ROS) in vitro or in vivo. TiO2 NPs could induce significant increase of ROS and excessive free radicals, destroying redox balance. ROS-mediated oxidative stress leads to the occurrence of lipid and protein peroxidation, which in turn would induce autophagy, apoptosis, and necrosis of cells. Increased ROS production induced by TiO2 NPs was generally associated with inflammatory response, mitochondrial dysfunction, and genetic damage in vitro and in vivo. Although ROS may play an important role in TiO2 NPs-induced biological effects, the specific way it produces and its complex relationship with subsequent biological effects need to be further clarified.

Ultrastructural Changes in the Cyclic Corpus Luteum of Dairy Cows with Different Body Condition

Abstract The aim of the study was to define ultrastructural changes in the ovarian cyclic corpus luteum (CL) of dairy cows with different body condition score (BCS, a 5-point scale). The ovaries were recovered from slaughtered Holstein cows of BCS1 (emaciation; n= 4), BCS2 (tendency to emaciation; n=4), BCS3 (average body condition; n= 4), BCS4 (tendency to fattening; n=4) and BCS5 (fattening; n=4). Average ages of cows were: 6.2, 4.1, 5.7, 5.5 and 6.36 years for BCS1, BCS2, BCS3, BCS4 and BCS5, respectively. For electron microscopy, functioning CL at the mid-luteal phase were fixed in the aldehyde solution and post-fixed in 1% OsO4 solution. For lipid visualization the samples were soaked in 1% p-phenylenediamine solution in acetone. Durcupan ultrathin sections (90 nm) were contrasted with uranyl acetate and lead citrate and viewed under Jeol transmission electron microscope. Occurrence of cell organelles was determined by counting the relative volume of individual cellular components using the modified universal test network. Luteal regression of cyclic CL was characterized by atrophy of lutein cells, condensation of organelles and cytoplasmic inclusions, increase in relative volumes of vacuoles, lysosomes, peroxisomes, autophagosomes and lipids. There were significant differences (p<0.05) among BCS1, BCS2, BCS4 and BCS5 cows in the occurrence of lipids, vacuoles, lysosomes and autophagosomes in the lutein cells compared to BCS3 cows. Cows with BCS2 or BCS1 had higher relative volume of lipid droplets, whilst the BCS4 or BCS5 cows had increased occurrence (relative volume) of vacuoles, lysosomes, peroxisomes and autolysosomes. These results show that luteolysis of cyclic CL of cows has different patterns in each BCS group; in the emaciated and fattened cows luteolysis starts earlier than in cows with average body condition.

Energetic reserves and digestive enzyme activities in juveniles of the red claw crayfish Cherax quadricarinatus nearby the point-of-no-return

Cherax quadricarinatus displays biological attributes that make it suitable for commercial aquaculture and, as a freshwater species, it has high starvation resistance. Previous studies demonstrated that after 40days of starvation only the 25% (PNR25) and after 50days the 50% (PNR50) of one-gram juveniles died. The objective of this study is to characterize the pattern of use of energetic reserves through the analysis of digestive enzyme activities and the occurrence of lipids, proteins and glycogen in the hepatopancreas and pleon muscle, nearby PNR25, PNR50 and after a feeding period. One-gram juveniles were randomly assigned to one of two feeding protocols: continuous feeding throughout 90-days (control) and starvation until day 50 and then feeding for the following 40days (treatment). Juveniles from each feeding protocol were weighed, measured and sacrificed at day 40, 50 or 90. Total lipids, glycogen and proteins were determined on hepatopancreas and pleon; and lipase, amylase and protease activities were also estimated in the hepatopancreas. Growth stopped during starvation and resumed when food was supplied. Close to the point-of-no-return 50 pleon muscle began to degrade diminishing protein content and the lipid content decreases significantly in the hepatopancreas. However, after the feeding period both reserves were completely replenished. Although glycogen levels were not affected during starvation, a pronounced accumulation of this nutrient in the pleon was triggered when food was available. The lipase activity decreased during starvation suggesting that the lipase whose activity was measured may not be synthesized when food is not available. Although starvation had no significant effect on the protease and amylase activities, they tended to decrease around the point-of-no-return and to increase after the feeding period. In this context, the present research provides new and relevant biological information on physiological and biochemical responses of crustaceans nearby PNR25 and PNR50.

Lipid occurrence, distribution and degradation to flavour volatiles during tea processing

The contents of neutral lipid, glycolipid and phospholipid and their fatty acid composition in three cultivars (clones) and processed leaves at different stages of black tea manufacture were measured. Glycolipids account for nearly 50% of the total lipids and are rich in linolenic acid. Phospholipids were present in the least amount (15%) and had a high proportion of oleic, linoleic and palmitic acids. Neutral lipids were found in moderate amounts (35%) and had a high content of lauric, myristic, palmitic, stearic, oleic and linoleic acids. Well-marked clonal variations in fatty acid composition of the lipid fractions were registered. With the maturation of the tea shoot, the lipid content increased. Considerable losses of lipids/fatty acids were observed in the withering process and again in the firing process. The other stages of processing (rolling and fermentation) registered only a minor change in lipid/fatty acid contents. Wide variation in lipid and flavour content was observed with season and a relation was evolved between them. The reason for the superior flavour of orthodox teas over CTC teas is explained on the basis of their lipid degradation. The changes in lipid content/fatty acids were related to the volatiles produced.

Occurrence of lipid A variants with 27-hydroxyoctacosanoic acid in lipopolysaccharides from members of the family Rhizobiaceae

Lipopolysaccharides (LPSs) isolated from several strains of Rhizobium, Bradyrhizobium, Agrobacterium, and Azorhizobium were screened for the presence of 27-hydroxyoctacosanoic acid. The LPSs from all strains, with the exception of Azorhizobium caulinodans, contained various amounts of this long-chain hydroxy fatty acid in the lipid A fractions. Analysis of the lipid A sugars revealed three types of backbones: those containing glucosamine (as found in Rhizobium meliloti and Rhizobium fredii), those containing glucosamine and galacturonic acid (as found in Rhizobium leguminosarum bv. phaseoli, trifolii, and viciae), and those containing 2,3-diamino-2,3-dideoxyglucose either alone or in combination with glucosamine (as found in Bradyrhizobium japonicum and Bradyrhizobium sp. [Lupinus] strain DSM 30140). The distribution of 27-hydroxyoctacosanoic acid as well as analysis of lipid A backbone sugars revealed the taxonomic relatedness of various strains of the Rhizobiaceae.

Seasonal variation of storage substances in stem cells of Diapensia lapponica. A light microscopic study

Owerwintering strategy of the sub‐arctic evergreen Diapensia lapponica has been studied by examining storage substances in the stem cells throughout different seasons. Stem segments were taken from 5 and 20 mm behind the shoot tip, fixed in glutaraldehyde/formaldehyde and embedded in Epon. Semithin sections were stained with Toluidine blue for general observation, Sudan black for lipids, Amido black for proteins and periodic acid‐Schiff s reagent (PAS) for carbohydrates. Lipids occurred abundantly throughout the year and seem to be the main storage substances. They were particularly common in mid‐winter in the lower part of the shoot. The highest lipid content was found in the pith cells and parenchyma cells of the conductive tissues. Large amyloplasts appeared in mid‐summer in higher amounts in the cortex than in the pith of the upper shoot, but vice versa in the lower stem. Starch was almost entirely lacking from November to April. Amido black staining did not indicate presence of protein bodies at any season.The occurrence of lipids and starch grains in the stem of Diapensia is in general similar to the occurrence of these substances in the leaves throughout the annual cycle.

Occurrence of lipid and phorbol ester activated protein kinase in wheat cells

Chromatography of the 30000 × g supernatant of wheat cell homogenates on DEAE-cellulose yielded a fraction whose protein kinase activity was specifically stimulated by phosphatidylserine plus phorbol ester or phosphatidylserine plus diolein. Such a characteristic activation pattern established this protein kinase as being a kinase C, an enzyme which plays an important role in the regulation of cell growth and differentiation in animal cells.

Selective binding of polymyxin B to negatively charged lipid monolayers

It is demonstrated by direct measurement of surface radioactivity that the cationic polypeptide antibiotic polymyxin B is specifically adsorbed to negatively charged lipid monolayers. The latter attracted the following amounts of the biologically active mono-N[ 14C] acetylpolymyxin B derivative (PX): lipid A from Proteus mirabilis, 0.17; phosphatidic acid, 0.12; phosphatidylglycerol and phosphatidylserine, 0.11; dicetylphosphate, 0.107; sulfoquinovosyldiglyceride, 0.104; phosphatidylinositol and cardiolipin, 0.095; and phosphatidylethanolamine, 0.017 μg/cm 2. Adsorption of PX to phosphatidylcholine, monogalactosyldiglyceride and stearylamine was almost or completely zero. Total lipids from Escherichia coli adsorbed 0.057 in comparison to 0.051 μg PX/cm 2 of an artificial mixture of phosphatidylethanolamine/phosphatidylglycerol/cardiolipin in the proportions 75 : 25 : 5. The concentration of the surface active PX at the air/water interphase was 0.091 μg/cm 2. These saturation surface concentrations of PXat lipid monolayers were reached at 1 μg/ml bulk concentrations in 2 mM NaCl/1 mM Tris · HCl, pH 7.2. They decreased with decreasing surface charge density of the adsorbing monolayer. In an experiment with cardiolipin/phosphatidylethanolamine mixtures it was shown that two molecules of cardiolipin induced adsorption of one molecule PX giving a 1 : 1 ratio with regard to positive and negative charges. This could be due to a similar charge density of about one charge per 40–50 Å 2 in PX and lipid bilayers composed of phospholipids. The electrostatic PX-lipid interaction was severely inhibited by 10 −2 and 10 −1 M Ca 2+ and Na +, respectively. It is discussed that the specificity of PX against Gram-negative bacteria is caused by the occurrence of lipid A, phosphatidylglycerol and cardiolipin at the cell surface of these microorganisms.

Untersuchung �ber nicht an Formk�rper gebundene Lipide in der pathologischen Kieferh�hle

Lipids can be found sporadically in the maxillary sinus especially in connection with chronic sinusitis. Thus, the occurence of cholesterol is known for decades. Nevertheless most of the lipids in the excretions of maxillary sinus are unknown or less investigated still today. It may be that there is a lack of simple analytical methods. The intention of this paper is to demonstrate early results with TLC-separation and determination of lipids in the maxillary sinus excretions during sinusitis. The samples were collected from patients of the HNO-Klinik Würzburg in connection with a therapeutic rinsing of the sinus. The effluent was concentrated and then separated into three fractions by ultracentrifugation: 1. The sediment, consisting of cells and some other undefined organic material. 2. A supernatant clear solution, containing inorganic material, proteins, amino-acids, lipids... 3. Sporadically a very thin layer on the surface of the clear solution. Since fraction 3, which contains lipids too, could not be found each time, our attention was directed on the lipids of the clear solution, where most of these substances are attached to proteins. As well as in the sediment we found in the clear solution cholesterol, free fatty acids, triglycerides and very seldom cholesterol-esters. The concentration of cholesterol is nearly the same as that of free fatty acids. The frequency of occurrence of lipids is considerable which prevents us until now to correlate the lipid-content to some features of diagnosis, prognosis and therapy.

The occurrence of lipids in Mycobacteriophage D29 propagated in Mycobacterium smegmatis ATCC 607.

The occurrence of lipids in Mycobacteriophage D29 propagated in Mycobacterium smegmatis ATCC 607.

Histochemical and electron microscopical studies on the epithelium of the fetal colon with special reference to the occurrence of lipids.

Absorbing cells of the colon of 28 human fetuses were studied histochemically while 4 were studied ultrastructurally. Cellular ultrastructure included: microvilli with a fuzz, typically lateral specializations, small mitochondria placed at the peripheral part of the cells, apically placed lysosomes, basally placed lipid droplets and disperse accumulations of glycogen. Only a slight pinocytosis was observed and the endoplasmic reticulum and Golgi apparatus were only poorly developed. Comparing the enzymatic findings with the ultrastructural findings, it is suggested that some absorption may take place in the fetal large intestine. It is further considered whether an intracellular synthesis of lipids may occur.

Studies on lipids in some Homopterous insects

There is little information available on the occurrence of lipids in aphids or other sucking insects, and little is known of the role of lipids in aphid nutrition. The purpose of the present investigation was to obtain preliminary information on several phases of these problems. The classes of lipids extracted from one aphid, Macrosiphum barri Essig, were separated by column chromatography. The fatty acids in each of these classes as well as in the crude lipid extracts from 20 other species of aphids and six species of leafhoppers were separated by gas-liquid chromatography. Nearly all of the fatty acids in M. barri were in the form of triglycerides, as in other insects that have been studied by previous investigators. The free fatty acids accounted for only a small percentage of the total quantity of lipids extracted from M. barri. In general, aphids had a high proportion of the fatty acids with a carbon chain length of 14 or less and a low proportion of fatty acids with 18 carbon atoms. The reverse was found for the leafhoppers analyzed. The fatty acid composition of an aphid appears to be a species characteristic, not appreciably influenced by the host plant. It changed with the stage of development in some species but not in others. Its possible usefulness in aphid taxonomy is uncertain at present. Fatty acids were found in the honeydew of two species of aphids. Their relative proportions in the honeydew of the green peach aphid and in the juice of its host suggest that linoleic acid may be required in the diet of that aphid.

Cytotopochemische Beitr�ge zum Lipidvorkommen in Vakuolen

The content of vacuoles of the two yeastsEndomyces lactis andCandida utilis and of the nucleolus in the cell nucleus ofAsterias sp. have been analysed upon the occurrence of lipids. For this reason, it were contrived observations and measurements in polarization optics, and used a few cytochemical reactions for lipids, employing partly the fluorescence microscope, partly the phase contrast technique. From the behaviour of the vacuolar leptones in this reactions it is concluded that at least the vacuoles of the two yeasts contain phospholipids, and the vacuoles of the starfish nucleoli, perhaps, beside this also lipoproteins in different amounts. From preliminary measurements with the yeasts in absorption photometry, it. moreover, follows that the tested reactions do not indicate the same substances, but, verisimiliter, a different inferior group of phospholipids.

Some physical investigations of the behaviour of bacterial surfaces: X. The occurrence of lipid in the streptococcal cell wall

1. 1. The incorporation of glycerol, sodium oleate, or sodium acetate in the growth medium resulted in an increase in the amount of lipid in the cell wall of a number of strains of Streptococcus pyogenes. 2. 2. This increase in lipid was detected electrophoretically by an increase in the mobility of the cells in the presence of sodium dodecyl sulphate, and was confirmed by solvent extraction. 3. 3. The amount of lipid in cells grown in glycerol medium varied during the growth cycle. 4. 4. Chemical groups sensitive to alkaline phosphatase (EC 3.1.3.1) were present on the surface of cells grown in Todd-Hewitt medium to which glycerol or oleate had been added, but not on cells grown in this medium alone. 5. 5. Two groups of naturally occurring Streptococcus pyogenes strains are exceptional in that they posses large amounts of cell-wall lipid under ordinary conditions of growth. These include (a) tetracycline-resistant strains, in which the rate of production of lipid is unusually high, and (b) strains isolated from impetigo lesions, which are tetracycline-sensitive and produce no extracellular lipase.