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1.
Melatonin and other 5-methoxyindoles are compounds usually associated with the pineal gland. Research is expanding from studies of pineal melatonin to studies of extrapineal organs and of other 5-methoxyindoles besides melatonin. Research in recent years has shown that the retina also contains and synthetises 5-methoxyindoles. The biochemical modes of action are still unclear. Nevertheless, they seem to have physiological roles in the pineal gland and the retina. These compounds are thought to participate in the regulation of the cyclic metabolism of the retina. Melatonin and other 5-methoxyindoles are often classified as neuromodulators. 相似文献
2.
Jyri Seppla Matti Melanen Ilmo Menp Sirkka Koskela Jyrki Tenhunen Marja‐Riitta Hiltunen 《Journal of Industrial Ecology》2005,9(4):117-130
The concept of eco-efficiency is commonly referred to as a business link to sustainable development. In this article, ecoefficiency is examined at a regional level as an approach to promoting the competitiveness of economic activities in the Finnish Kymenlaakso region and mitigating their harmful impacts on the environment. The aim is to develop appropriate indicators for monitoring changes in the eco-efficiency of the region. A starting point is to produce indicators for the environmental and economic dimensions of regional development and use them for measuring regional eco-efficiency. The environmental impact indicators are based on a life-cycle assessment method, producing different types of environmental impact indicators: pressure indicators (e.g., emissions of CO2 ), impact category indicators (e.g., CO2 equivalents in the case of climate change), and a total impact indicator (aggregating different impact category indicator results into a single value). Environmental impact indicators based on direct material input, total material input, and total material requirement of the Kymenlaakso region are also assessed. The economic indicators used are the gross domestic product, the value added, and the output of the main economic sectors of Kymenlaakso. In the eco-efficiency assessment, the economic and environmental impact indicators are monitored in the same graph. In a few cases eco-efficiency ratios can also be calculated (the economic indicators are divided by the environmental indicators). Output (= value added + intermediate consumption) is used as an economic indicator related to the environmental impact indicators, which also cover the upstream processes of the region's activities. In the article, we also discuss the strengths and weaknesses of using the different environmental impact indicators. 相似文献
3.
Marco L. F. Giuseppin Hendrikus M. J. van Eijk Marja Hellendoorn José W. van Almkerk 《Applied microbiology and biotechnology》1987,27(1):31-36
Summary The changes in cell wall strength of Hansenula polymorpha have been investigated in continuous cultures with respect to the recovery of methanol oxidase (MOX). Cultures grown on several substrate mixtures that enable induction of MOX have been compared with cultures grown on methanol as the sole inducer. The effects of dilution rate (D) on lysis properties have been studied. The cell wall strength was consistently influenced by growth media and D. Media containing glycerol/methanol showed the slowest lysis kinetics, with a large fraction of non-degradable cell wall material. In continuous cultures grown on a mixture of glucose and methanol both the resistance to zymolyase and the mean cell wall thickness increased at D<0.1 h–1. The yield of MOX by zymolyase lysis is reproducible and up to 100% higher than that of the standard ultrasonic treatment. The lysis kinetics indicated that zymolyase punctures the cell wall; since the release rate of MOX is lower than that of protein, the cell contents will leak through. At D-values>0.2 h–1, both protein and MOX release rates increase, reflecting a change in lysis mechanism due to the increased fraction of thin daughter cells. Kinetic analysis of zymolyase lysis using both physical and enzymatic methods provides information for achieving optimal recovery of MOX.Abbreviations and symbols
C
MOX
MOX activity [MOX units·g X–1]
-
D
dilution rate [h–1]
- MOX
methanol oxidase
- kc
decay rate constant of A 610 nm [min–1]
- kd
decay constant of MOX activity [min–1]
- kdis
dissociation rate constant [min–1]
- kMOX
release rate constant of MOX activity [min–1]
- kp
release rate constant of protein [min–1]
- R
recovery efficiency of enzyme [-]
-
St
stability of enzyme [-] 相似文献
4.
The plasma membrane of Streptococcus cremoris: isolation and partial characterization 总被引:1,自引:0,他引:1
Marja A. Rimpiläinen Kaarina Niskasaari† Katri M. S. Juutinen† Eeva-Liisa Nurmiaho-Lassila‡ Raili I. Forsean† 《Journal of applied microbiology》1986,60(5):389-394
Plasma membrane was isolated from Streptococcus cremoris using mutanolysin from a streptomycete as the cell wall-degrading enzyme and phenylmethylsulfonyl fluoride as protease inhibitor. The specific activity of membrane-bound enzyme, adenosine triphosphatase (ATPase), was 4 μmol/mg protein per min, which was 5–10 times higher than the activity found in other fractions obtained during the isolation procedure. The number of polypeptides in the plasma membrane was approximately 50 with molecular weights 13 500–100 000, minor changes in the polypeptide pattern were observed when the plasma membrane was isolated without a protease inhibitor. The chemical composition of the membrane preparation was 49.7% protein, 21.9% lipid, 5.1% aminosugars, 17.3% RNA and 0.03% DNA. Electron microscopic examination confirmed the membrane to be practically devoid of cell wall components. Our results indicate that the membrane integrity is well retained and therefore the membrane preparation is suitable for detailed studies on vectorial metabolism and its enzymes, e.g. ATPase. 相似文献
5.
R. Hasselback Marja Soots John Curtis G. L. Robertson D. H. Cowan G. D. Hart 《CMAJ》1967,96(25):1610-1614
The presence of definite cytoplasmic granulation in at least some of the malignant cells was used as the sole criterion to separate 156 patients with acute leukemia into two groups: 110 with myeloblastic (AML), and 46 with lymphoblastic or stem cell leukemia (ALL). The median survival from the onset of symptoms in patients with AML was 20 weeks, and those with ALL 37 weeks. The difference in survival in these two groups is much greater for patients under the age of 25 than for those over the age of 25. 相似文献
6.
Characterization of the genes of the 2,3-butanediol operons from Klebsiella terrigena and Enterobacter aerogenes. 总被引:5,自引:1,他引:4 下载免费PDF全文
K Blomqvist M Nikkola P Lehtovaara M L Suihko U Airaksinen K B Strby J K Knowles M E Penttil 《Journal of bacteriology》1993,175(5):1392-1404
The genes involved in the 2,3-butanediol pathway coding for alpha-acetolactate decarboxylase, alpha-acetolactate synthase (alpha-ALS), and acetoin (diacetyl) reductase were isolated from Klebsiella terrigena and shown to be located in one operon. This operon was also shown to exist in Enterobacter aerogenes. The budA gene, coding for alpha-acetolactate decarboxylase, gives in both organisms a protein of 259 amino acids. The amino acid similarity between these proteins is 87%. The K. terrigena genes budB and budC, coding for alpha-ALS and acetoin reductase, respectively, were sequenced. The 559-amino-acid-long alpha-ALS enzyme shows similarities to the large subunits of the Escherichia coli anabolic alpha-ALS enzymes encoded by the genes ilvB, ilvG, and ilvI. The K. terrigena alpha-ALS is also shown to complement an anabolic alpha-ALS-deficient E. coli strain for valine synthesis. The 243-amino-acid-long acetoin reductase has the consensus amino acid sequence for the insect-type alcohol dehydrogenase/ribitol dehydrogenase family and has extensive similarities with the N-terminal and internal regions of three known dehydrogenases and one oxidoreductase. 相似文献
7.
Atlantic salmon (Salmo salar L.) were fed on a control diet or experimental diets containing betaine (15 mg g-1) or dimethylglycine (DMG, I mg g-1 or 5 mg g-1). After 10 weeks of feeding, resistance to infection was assessed following inoculation with Vibrio anguillarum. Total blood and differential leucocyte counts were made, and plasma lysozyme and ceruloplasmin were assayed as non-specific humoral factors. The mortality during the bacterial exposure was of the same magnitude in all feeding groups. Betaine or DMG had no effect on the 'basal' levels of plasma total protein, lysozyme or ceruloplasmin, but 3 days postinjection the lysozyme and ceruloplasmin levels were higher in the control group compared with the experimental groups. In both DMG groups, the lymphocyte response took place 1-2 weeks earlier than in the control or betaine supplemented group indicating that DMG has an immunomodulating effect on salmon. 相似文献
8.
Determinants of the high-methionine trait in wild and exotic germplasm may have escaped selection during early cultivation of maize 总被引:3,自引:1,他引:2
Sanjay Swarup Marja C.P. Timmermans Sumita Chaudhuri Joachim Messing 《The Plant journal : for cell and molecular biology》1995,8(3):359-368
The 18 kDa high-methionine δ-class zein gene from maize has been cloned, and its regulation, structure, and map position studied. These studies have shown that (i) zein genes may also contain tryptophan and lysine codons, (ii) the 18 kDa and the related 10 kDa zein gene are coordinately regulated, but their products accumulate to different levels in a genotype-dependent manner, (iii) the duplication of δ-zein genes probably involved unequal crossing over, (iv) no copy correction in either direction has occurred from teosinte to modern corn, and (v) the duplication of of the 18 kDa zein gene probably occurred before the tetraploidization of a progenitor chromosome. The work shows that important nutritional quality determinants like the high-methionine seed proteins are abundant in several exotic and wild corn varieties and low in most of the inbreds screened. The lack of a selectable phenotype for such quality traits during initial domestication and breeding of corn would have eliminated cis and trans regulatory determinants from the germplasm used in modern corn breeding. Examples of the high-methionine δ-class zeins shown here may be generally applicable in explaining the low nutritional quality of most present-day corn grown. 相似文献
9.
The affinity of beta-carbolines, which may be formed in the body, to benzodiazepine and opiate receptors was studied by measuring their ability to inhibit the binding of [3H]-flunitrazepam and [3H]-dihydromorphine on rat brain synaptosomal membranes. All "aromatized" beta-carbolines studied (norharmane, harmane and 6-methoxyharmane) inhibited the specific binding of [3H]-flunitrazepam in micromolar concentrations, dihydro-beta-carbolines (6-methoxyharmalan, harmalol) were less potent, while all tetrahydro-beta-carbolines showed very low affinity. 6-Hydroxytetrahydroharmane, which is formed by condensation 5HT with acetaldehyde, inhibited [3H]-dihydromorphine binding in micromolar concentration, while norharmane and tetrahydro-beta-carbolines without OH-group showed little affinity. beta-Carbolines are the most potent known natural benzodiazepine receptor ligands. Because they are formed after alcohol drinking, their effects on benzodiazepine and opiate receptors may be connected with alcohol dependence although some beta-carbolines may inhibit 5HT uptake in still lower concentrations. 相似文献
10.
The electrocardiogram of 9 horses was continuously recorded for 24 h with Holter monitoring to examine the variations in heart rate and rhythm during daily routine procedures and at night. Three horses had transient sinus bradycardia, and 3 had periods of sinus tachycardia. Heart blocks were detected in 3 horses, and all horses had periods of sinus arrhythmia. These changes in the heart rate and rhythm were apparently caused by variations in autonomic nervous system tone and they are probably “normal” findings in resting, undisturbed horses. Ventricular premature depolarisations were not observed in any horse, but some single supraventricular premature contractions were detected. There was preliminary evidence that in order to register the real resting heart rate and rhythm of a horse the ECG should be recorded over a long period, and also at night and without the presence of the investigator. 相似文献