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1.
A fermented milk, Kefir, contains an active substance which enhances IFN- secretion of a human osteosarcoma line MG-63 treated with a chemical inducer, poly I: poly C. The active substance in the fermented milk was identified to be sphingomyelin (SpM) by a combined use of a fast atom bombardment mass spectrometry (FAB-MS) and a fast atom bombardment tandem mass spectrometry (FAB-MS/MS). SpM from fermented milk (F-SpM) was a mixture of four molecular species of SpMs having C21-, C22-, C23- and C24-fatty acids. F-SpM enhanced the IFN secretion 14 times, SpMs from other sources also enhanced moderately (2–3 times). Sphingosine and lysosphingomyelin also enhanced the activity but ceramide and cerebroside did not.Abbreviations IFN- interferon- - SpM sphingomyelin - Lyso-SpM lysosphingomyelin - SpS sphingosine - FAB-MS fast atom bombardment mass spectrometry - FAB-MS/MS fast atom bombardment tandem mass spectrometry  相似文献   

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Milk is a complex physiological liquid that simultaneously provides nutrients and bioactive components that facilitate the successful postnatal adaptation of the newborn infant by stimulating cellular growth and digestive maturation, the establishment of symbiotic microflora, and the development of gut-associated lymphoid tissues. The number, the potency, and the importance of bioactive compounds in milk and especially in fermented milk products are probably greater than previously thought. They include certain vitamins, specific proteins, bioactive peptides, oligosaccharides, organic (including fatty) acids. Some of them are normal milk components, others emerge during digestive or fermentation processes. Fermented dairy products and probiotic bacteria decrease the absorption of cholesterol. Whey proteins, medium-chain fatty acids and in particular calcium and other minerals may contribute to the beneficial effect of dairy food on body fat and body mass. There has been growing evidence of the role that dairy proteins play in the regulation of satiety, food intake and obesity-related metabolic disorders. Milk proteins, peptides, probiotic lactic acid bacteria, calcium and other minerals can significantly reduce blood pressure. Milk fat contains a number of components having functional properties. Sphingolipids and their active metabolites may exert antimicrobial effects either directly or upon digestion.  相似文献   

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The aim of this study was to investigate the chemopreventive effect of probiotic fermented milk and chlorophyllin on aflatoxin B? (AFB?) induced hepatocellular carcinoma. In vivo trials were conducted on 200 Wistar rats allocated to eight groups. Rats in the positive control group were given intraperitoneal injection of aflatoxin B? at 450 μg/kg body weight twice a week for 6 weeks. The rats were sacrificed and dissected at 25th week of the experiment, and comet assay was carried out in hepatic cells to assess the genotoxicity or DNA damage. The tumour incidence was decreased by approximately one-third than AFB? control group. The expression of c-myc bax, bcl-2, cyclin D1, p53 and rasp-21 genes was also studied. A significant (P<0.05) reduction in DNA damage was observed in probiotic fermented milk with chlorophyllin group as compared to aflatoxin B? control group. The c-myc, bcl-2, cyclin D1 and rasp-21 level was found to be highest in AFB? control group as compared to the treatment group. The results advocate the enhanced protective potential of probiotic fermented milk and chlorophyllin against AFB?-induced molecular alterations in hepatic cells during carcinogenesis.  相似文献   

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Protoplasts of a strain ofA. fœcalis incapable of utilizing β-sitosterol as carbon source for growth were fused with protoplasts ofA. oxydans — a strain capable of complete degradation of β-sitosterol. Five fusants showing morphology and pattern of transformation of C-19 steroids identical toA. Fœcalis were selected. Analysis of the fermentation broth containing β-sitosterol showed that the fusants were capable of utilizing β-sitosterol for growth but their pattern of metabolite formation from β-sitosterol was different from that ofA. oxydans. The study revealed that the protoplast fusion technique could be used for intergeneric transfer of genetic determinants linked to partial cleavage of β-sitosterol side chain toA. fœcalis fromA. oxydans.  相似文献   

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Got milk? The secret life of laticifers   总被引:1,自引:0,他引:1  
Laticifers are specialized cells that occur in over 20 plant families in several unrelated angiosperm orders. Although laticifers are likely to be of polyphyletic origin, their occurrence is considered a morphological indicator of relatedness among species. The classification of laticifers is based on developmental patterns and overall morphology. The cytoplasmic latex exuded in response to damage often includes specialized metabolites, such as cardenolides, alkaloids and natural rubber. Laticifers provide an effective location to store defense metabolites, although not all latex-bearing plants accumulate bioactive natural products. Ecophysiological studies have shown that latex and its associated metabolites are vital for the defense of plants against insects. The anatomy, development and physiology of laticifers are discussed with a focus on evolutionary and ecological perspectives.  相似文献   

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J. S. Grant Reid  Hans Meier 《Planta》1973,112(4):301-308
Summary The activities of -galactosidase, -mannosidase and -mannosidase were determined in extracts from the endosperm and from the embryo of fenugreek seeds at different stages of germination. Endosperm homogenates contained little or no activity of the above enzymes in the early stages of germination, before the reserve galactomannan began to be mobilised. The onset of galactomannan breakdown coincided with the appearance of -galactosidase and -mannosidase activities, which increased throughout the period of galactomannan degradation and then remained constant. A similar rise in -galactosidase and -mannosidase activities occurred during galactomannan breakdown in dry-isolated endosperms incubated under germination conditions. The increase could be suppressed by metabolic inhibitors which also inhibit galactomannan breakdown. Embryo homogenates contained high -galactosidase, high -mannosidase and some -mannosidase activity at all stages of germination.No oligomannosyl -1,4 phosphorylase activity could be detected either in the endosperm or in the embryo.It is concluded that the galactomannan of fenugreek is broken down by a series of hydrolases secreted by the aleurone layer of the endosperm. They include -galactosidase, -mannosidase and probably also endo--mannanase.This is part four in a series of papers dealing with galactomannan metabolism. Part three: Planta (Berl.) 106, 44–60 (1972).  相似文献   

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HLA-G is a non-classical major histocompatibility complex class I molecule selectively expressed on extravillous trophoblast cells at the fetal—maternal interface. HLA-G may play an important role in maintaining maternal immune tolerance of the semi-allogenic fetus. In this study, we demonstrate for the first time the protective role of HLA-G during pregnancy. Indeed, cytotrophoblast cells of the fetus are resistant to lytic activity by maternal decidual natural killer cells. In order to precisely characterize the immunological functions of HLA-G products, we have investigated the protective role of the membrane-bound HLA-G1 and HLA-G2 isoforms against NK cell cytotoxicity. For this purpose, HLA-G1 and HLA-G2 cDNAs were transfected into the HLA-class I negative human K562 cell line. We demonstrate that both HLA-G1 and HLA-G2 transfectants inhibit NK cytolysis observed in peripheral blood from 25 donors (males and females). This led us to the conjecture that HLA-G is the public ligand for natural killer inhibitory receptors present in all individuals.  相似文献   

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The concept of “ethno-microbiology” is to understand the indigenous knowledge of the Indian people for production of culturally and organoleptically acceptable fermented foods by natural fermentation. About 1000 types of common, uncommon, rare, exotic and artisan fermented foods and beverages are prepared and consumed in different geographical regions by multi-ethnic communities in India. Indian fermented foods are mostly acidic and some are alkaline, along with various types of alcoholic beverages. A colossal diversity of microorganisms comprising bacteria mostly belongs to phylum Firmicutes, filamentous moulds and enzyme- and alcohol-producing yeasts under phyla Ascomycota and Mucoromycota, and few bacteriophages and archaea have been reported from Indian fermented foods. Some microorganisms associated with fermented foods have functionalities and health promoting benefits. “Ethno-microbiology” of ethnic Indian people has exhibited the proper utilisation of substrates either singly or in combination such as fermented cereal-legume mixture (idli, dosa and dhokla) in South and West India, sticky fermented soybean food (kinema and related foods), fermented perishable leafy vegetable (gundruk and related foods), fermented bamboo shoots (soibum and related foods) and fermented fish (ngari and others) in North East India, and fermented meat and sausage-like products in the Indian Himalayas, fermented coconut beverage (toddy) in coastal regions, and various types of naturally fermented milk products (dahi and related products) in different regions of India. This review has also highlighted the “ethno-microbiology” knowledge of the people involving the consortia of essential microorganisms in traditionally prepared amylolytic starters for production of cereal-based alcoholic beverages. The novelty of this review is the interpretation of ethno-microbiological knowledge innovated by ethnic Indian people on the use of beneficial microorganisms for food fermentation to obtain the desired fermented food products for consumption.  相似文献   

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Automatic milking systems (AMS), or milking robots, are becoming widely accepted as a milking technology that reduces labour and increases milk yield. However, reported amount of labour saved, changes in milk yield, and milk quality when transitioning to AMS vary widely. The purpose of this study was to document the impact of adopting AMS on farms with regards to reported changes in milking labour management, milk production, milk quality, and participation in dairy herd improvement (DHI) programmes. A survey was conducted across Canada over the phone, online, and in-person. In total, 530 AMS farms were contacted between May 2014 and the end of June 2015. A total of 217 AMS producers participated in the General Survey (Part 1), resulting in a 41% response rate, and 69 of the respondents completed the more detailed follow-up questions (Part 2). On average, after adopting AMS, the number of employees (full- and part-time non-family labour combined) decreased from 2.5 to 2.0, whereas time devoted to milking-related activities decreased by 62% (from 5.2 to 2.0 h/day). Median milking frequency was 3.0 milkings/day and robots were occupied on average 77% of the day. Producers went to fetch cows a median of 2 times/day, with a median of 3 fetch cows or 4% of the herd per robot/day. Farms had a median of 2.5 failed or incomplete milkings/robot per day. Producers reported an increase in milk yield, but little effect on milk quality. Mean milk yield on AMS farms was 32.6 kg/cow day. Median bulk tank somatic cell count was 180 000 cells/ml. Median milk fat on AMS farms was 4.0% and median milk protein was 3.3%. At the time of the survey, 67% of producers were current participants of a DHI programme. Half of the producers who were not DHI participants had stopped participation after adopting AMS. Overall, this study characterized impacts of adopting AMS and may be a useful guide for making this transition.  相似文献   

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Summary

World-wide, our coastal waters have been subject to an increased nutrient input since the latter part of the nineteenth century. This has led to the eutrophication or ‘nutrient pollution’ of many coastal sites, including Langstone Harbour and the Ythan Estuary here in the UK. Eutrophication at these and, indeed, at other nutrient enriched sites is evident by the appearance of large blooms of fast-growing opportunistic macroalgae. Blooms of macroscopic species of green algae (Chlorophyta: Ulvophyceae) are particularly common and the phenomenon is often referred to as the occurrence of green tides.

Green tides may have a dramatic environmental impact, causing much damage to the local ecosystem. Numerous strategies have hence been employed in order to combat the problem, but to date there has been limited success. For this reason, current research in the UK is aimed at increasing our knowledge of green tide algae in terms of their ecophysiology, whilst further investigation of the nutrient pathways and fluxes within specific ecosystems has been deemed necessary. It is anticipated that this ‘backto basics’ approach will ultimately contribute to the development of new, successful eutrophication management strategies.  相似文献   

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A high order method for measuring urea concentrations in milk and milk powder was developed. The method can be applied to certify the concentration of urea in some new milk and milk powder CRMs. This high accurate method for analysis of milk is valuable given the inherent challenges associated with the complexity of the sample matrix. A measurement procedure based on gas chromatography/isotope dilution mass spectrometry (GC/IDMS) was developed. Samples were pre-treated with acetonitrile to remove proteins and the method was applied to determine urea concentrations in milk and milk powder. Excellent precision was obtained, with within- and between-set coefficients of variation of 0.15–0.46 and 0.18–0.65%, respectively. The measurement uncertainty is evaluated. The method can trace to mass.  相似文献   

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Purpose  

This paper investigates different methodologies of handling co-products in life cycle assessment (LCA) or carbon footprint (CF) studies. Co-product handling can have a significant effect on final LCA/CF results, and although there are guidelines on the preferred order for different methods for handling co-products, no agreed understanding on applicable methods is available. In the present study, the greenhouse gases (GHG) associated with the production of 1 kg of energy-corrected milk (ECM) at farm gate is investigated considering co-product handling.  相似文献   

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