Demonstration of safety of probiotics -- a review

Probiotics are commonly defined as viable microorganisms (bacteria or yeasts) that exhibit a beneficial effect on the health of the host when they are ingested. They are used in foods, especially in fermented dairy products, but also in pharmaceutical preparations. The development of new probiotic strains aims at more active beneficial organisms. In the case of novel microorganisms and modified organisms the question of their safety and the risk to benefit ratio have to be assessed. Lactic acid bacteria (LAB) in foods have a long history of safe use. Members of the genera Lactococcus and Lactobacillus are most commonly given generally-recognised-as-safe (GRAS) status whilst members of the genera Streptococcus and Enterococcus and some other genera of LAB contain some opportunistic pathogens. Lactic acid bacteria are intrinsically resistant to many antibiotics. In many cases resistances are not, however, transmissible, and the species are also sensitive to many clinically used antibiotics even in the case of a lactic acid bacteria- associated opportunistic infection. Therefore no particular safety concern is associated with intrinsic type of resistance. Plasmid-associated antibiotic resistance, which occasionally occurs, is another matter because of the possibility of the resistance spreading to other, more harmful species and genera. The transmissible enterococcal resistance against glycopeptide antibiotics (vancomycin and teicoplanin) is particularly noteworthy, as vancomycin is one of the last effective antibiotics left in the treatment of certain multidrug-resistant pathogens. New species and more specific strains of probiotic bacteria are constantly identified. Prior to incorporating new strains into products their efficacy should be carefully assessed, and a case by case evaluation as to whether they share the safety status of traditional food-grade organisms should be made. The current documentation of adverse effects in the literature is reviewed. Future recommendations for the safety of already existing and new probiotics will be given.     

Current Status of Laser Welding with Wire Feed

Laser welding, currently being actively investigated worldwide, is about to become an important joining method. Traditionally laser welding has always been autogenous. With increased demands of welded joint and industrial applicability laser welding is now more frequently used with wire feed. This paper reviews laser welding with continuous wire feed and illustrates its potential advantages and problems. The current knowledge about basics of the techniques, effects of various variables and phenomena involved are summarized and discussed. It is shown that influence of variables requires understanding of their individual and combined effects. The survey indicates that although laser welding with continuous wire feed is a potential technique for many applications, R&D effort is still required to make the installation economically feasible.     

Tocopherols and tocotrienols in finnish foods: Fish and fish products

A high performance liquid chromatographic method with fluorescence detection was used to determine the content of tocopherols in Finnish fish species. Samples were obtained from different sea and lake areas. Autumn- and spring-caught fish were analyzed separately. The vitamin E of all species consisted almost entirely of α-tocopherol. Muscle and roe contained relatively high levels of α-tocopherol. High- and medium-fat fish contained 2 mg and low-fat fish 1 mg/100 g on average. In high-fat fish the tocopherol: fat ratio was lower than in low-fat fish. Between-species differences in tocopherol content were observed, as were between-sample differences within the same species. Fish caught in the spring, the spawning season of most species, had a higher tocopherol content (and a lower fat content) than those caught in the autumn. Marine fish had a higher tocopherol (and fat) content than lake fish of the same species.     

Paclitaxel changes sympathetic control of blood pressure

Paclitaxel has become part of standard therapy in the treatment of ovarian and breast cancer. Concern has been raised about the effects of paclitaxel on cardiovascular function. Therefore, this study of the effects of paclitaxel on autonomic cardiovascular control was initiated. Eighteen women treated for ovarian or breast cancer were examined with autonomic cardiovascular function tests, once before the treatment and once after the second course of paclitaxel. Heart rate and blood pressure variability and changes in heart rate and blood pressure responses to the tests were measured. Baroreflex sensitivity was calculated from the Valsalva manoeuvre non-invasively. Paclitaxel did not change heart rate variability at rest compared with the pretreatment level. However, medium frequency variability of blood pressure was smaller after treatment with paclitaxel. Paclitaxel treatment did not impair the heart rate and blood pressure responses to the autonomic function tests. The results do imply that paclitaxel alters sympathetic control of blood pressure. Nevertheless, paclitaxel does not appear to precipitate autonomic cardiac neuropathy.     

Photoresist-based integration of enzyme functionality into MEMS

We demonstrate the direct immobilization of glucose oxidase and lactate oxidase onto photoresists commonly used in microfabrication. The method allows for a cost-effective, facile inclusion of enzyme functionality into novel MEMS devices because it does not require any chemical or physical pre-treatment of surfaces, and it is largely compatible with existing fabrication technologies. We used fluorescence imaging and absorbance spectrometry to confirm attachment of the enzymes onto the photoresists and to determine their activity. In addition, the procedure was used to successfully integrate enzyme functionality into a photoresist-based biosensor. This further demonstrates the effectiveness of the approach, and opens a path towards other novel applications in MEMS research.     

Arsenic removal by native and chemically modified lactic acid bacteria

Arsenic in drinking water is a major health problem globally. Simple, novel methods are needed for its removal from water, especially in rural areas. For this purpose, the potential of different microbes in toxin and heavy metal removal from water has gained interest. This study focused on the arsenic removal capacity of three Lactobacillus strains in their native and chemically modified forms. Both native and methylated forms of all three strains were not efficient in arsenic removal. Aminated Lactobacillus casei DSM20011 was observed to remove As(V) but not As(III) in water. Removal was fast, dependent on pH and As(V) concentration. The highest removal percentage 38.1+/-9.0% was observed at the lowest As(V) concentration (100 microg/l) studied at pH 7. The maximum As(V) removal capacity, calculated from Langmuir isotherm, was 312+/-68 microg As(V)/g dry biomass. Interactions between As(V) and the bacteria were weak, demonstrated by release of removed As(V) when contact time was prolonged. Desorption with 1.5 mM HNO3 and NaOH released all bound As(V) indicating that removal occurred at the bacterial surface.     

Oxidation of Ingested Phenolics in the Tree-Feeding Caterpillar <Emphasis Type="Italic">Orgyia leucostigma</Emphasis> Depends on Foliar Chemical Composition

Tannins are believed to function as antiherbivore defenses, in part, by acting as prooxidants. However, at the high pH found in the midguts of caterpillars, the oxidative activities of different types of tannins vary tremendously: ellagitannins > galloyl glucoses > condensed tannins. Ingested ascorbate is utilized by caterpillars to minimize phenolic oxidation in the midgut. Thus, leaves that contain higher levels of reactive tannins and lower levels of ascorbate were hypothesized to produce higher levels of phenolic oxidation in caterpillars. We tested this hypothesis with eight species of deciduous trees by measuring their foliar phenolic and ascorbate compositions and measuring the semiquinone radical (oxidized phenolic) levels formed in caterpillars that ingested each species. When the generalist caterpillars of Orgyia leucostigma (Lymantriidae) fed on the leaves of tree species in which condensed tannins were predominant (i.e., Populus tremuloides, P. deltoides, and Ostrya virginiana), semiquinone radical levels were low or entirely absent from the midgut contents. In contrast, species that contained higher levels of ellagitannins (or galloyl rhamnoses; i.e., Quercus alba, Acer rubrum, and A. saccharum) produced the highest levels of semiquinone radicals in O. leucostigma. Low molecular weight phenolics contributed relatively little to the overall oxidative activities of tree leaves compared with reactive tannins. Ascorbate levels were lowest in the species that also contained the highest levels of oxidatively active tannins, potentially exacerbating phenolic oxidation in the gut lumen. We conclude that the tannin compositions of tree leaves largely determine the effectiveness of foliar phenolics as oxidative defenses against caterpillars such as O. leucostigma.     

Rapid Herbivore-Induced Changes in Mountain Birch Phenolics and Nutritive Compounds and Their Effects on Performance of the Major Defoliator, Epirrita autumnata

Insect damage changes plant physiology and chemistry, and such changes may influence the performance of herbivores. We introduced larvae of the autumnal moth (Epirrita autumnataBorkh.) on individual branches of its main host plant, mountain birch (Betula pubescens ssp. czerepanovii (Orlova) Hämet-Ahti) to examine rapid-induced plant responses, which may affect subsequent larval development. We measured systemic responses to herbivory by analyzing chemistry, photosynthesis, and leaf growth, as well as effects on larval growth and feeding, in undamaged branches of damaged and control trees. Larvae reared on leaves from intact branches of the herbivore-damaged trees grew faster than those reared on leaves of control trees, indicating systemic-induced susceptibility. Herbivore damage did not lead to systemic changes in levels of primary nutrients or phenolic compounds. The analyses of photosynthetic activity and individual hydrolyzable tannins revealed a reversal of leaf physiology-herbivore defense patterns. On control trees, consumption by E. autumnata larvae was positively correlated with photosynthetic activity; on damaged trees, this correlation was reversed, with consumption being negatively correlated with photosynthetic activity. A similar pattern was found in the relationship between monogalloylglucose, the most abundant hydrolyzable tannin of mountain birch, and leaf consumption. Among the control trees, consumption was positively correlated with concentrations of monogalloylglucose, whereas among herbivore-damaged trees, this correlation was reversed and became negative. Our results suggest that herbivore performance is related to both concentrations of phenolic compounds and photosynthetic activity in leaves. This linkage between herbivore performance, leaf chemistry, and physiology was sensitive to induced plant responses caused by slight herbivore damage.     

Characterizing the evolving research on enterprise content management

Innovations in network technologies in the 1990's have provided new ways to store and organize information to be shared by people and various information systems. The term Enterprise Content Management (ECM) has been widely adopted by software product vendors and practitioners to refer to technologies used to manage the content of assets like documents, web sites, intranets, and extranets In organizational or inter-organizational contexts. Despite this practical interest ECM has received only little attention in the information systems research community. This editorial argues that ECM provides an important and complex subfield of Information Systems. It provides a framework to stimulate and guide future research, and outlines research issues specific to the field of ECM.