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Keratinolytic potential of A. keratinophila (DSM 44409T), a newly described Amycolatopsis sp. isolated from cultivated soil in Kuwait, was demonstrated using keratinazure as the sole source of carbon and nitrogen as estimated by gel diffusion assay. Effects of 12 various nutritional supplements on the keratinolytic and azocollytic activities were determined. NH4H2PO4 and KNO3 in the medium supported a significantly higher keratinolytic activity than other supplements. However, azocollytic activities in all the supplemented media and the control were same. Best combination of carbon and nitrogen supplements (galactose and NH4H2PO4 respectively) used to evaluate the dynamics of growth and enzymes (keratinase and protease) activities of the isolate revealed a luxuriant growth with optimal keratinolytic activity occurring during the log phase. Other parameters of the fermentation medium, including pH, biomass accumulation, total protein and free amino acid concentrations were also studied.  相似文献   

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Combining nutritional supplements to achieve synergistic benefit is a common practice in the nutraceutical industry. However, establishing added health benefit from a combination of natural ingredients is often assumed, untested and without regard to the principle of metabolic competition between the active components. Here, we report on the combination of a cat's claw water extract (C-Med-100, carboxy alkyl esters = active ingredients) + medicinal mushroom extracts (Cordyceps sinensis, Grifola blazei, Grifolafrondosa, Trametes versicolor and Ganoderma lucidum, polysaccharides = active ingredients) + nicotinamide + zinc into a formulation designed to optimize different modes of immunostimulatory action, and yet that would avoid metabolic antioxidant competition yielding less than expected efficacious effects. Isobole curve analyses of these two active classes of ingredients determined by growth inhibition of HL-60 human leukemic cells in vitro confirmed they were indeed synergistic when in combination, and not metabolically competitive. Furthermore, an in vivo study showed significant health benefit for 14 subjects treated for 4 weeks with the unique C-Med-100/mushroom extract formulation in that they had reduced pain, reduced fatigue, weight loss and a reduced presence of DNA damage in peripheral blood assessed by (8-OH) guanine DNA adducts and elevation in serum protein thiols. Because this broad-based panel of clinical parameters indicating clinical efficacy has never been demonstrated before for either of the active ingredients evaluated alone in humans, these data were taken as strong evidence that the combination of C-Med-100 + mushroom extracts + nicotinamide + zinc gave additive or synergistic effects to health benefit, and thus supported no efficacious limits from metabolic competition regarding this particular formulation.  相似文献   

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《Cell》2022,185(11):1888-1904.e24
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We evaluated the frequency and severity of illnesses caused by various microbial pathogens in 15 children with severe combined immune deficiency disease (SCID) and 8 with acquired immune deficiency syndrome (AIDS). There were 35 viral, 23 bacterial, 19 mycotic and 13 parasitic infections. Nineteen of the 23 patients died of infection; Pneumocystis carinii pneumonia, giant-cell pneumonia due to paramyxoviruses and various disseminated viral infections were responsible for most deaths in both groups. The emerging role of paramyxoviruses was illustrated by the fact that they were responsible for giant-cell pneumonia in seven patients. Viral enteric infections were frequent in both groups. The variety of infectious microorganisms and the severity of resulting illnesses in the patients with AIDS were similar to those in the patients with SCID.  相似文献   

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Increased O2 metabolism imposed by physical exercise is likely to augment the production of active O2 species that have been shown to react with lipids, proteins, and DNA. Antioxidants and antioxidant enzymes, such as the selenium enzyme glutathione peroxidase, minimize or prevent such potentially toxic reactions. This study shows that selenium deficiency decreases glutathione peroxidase activity in liver and muscle (less than 80%, P less than 0.001), increases total glutathione in liver, muscle, and plasma (P less than 0.05) and increases muscle cytochrome oxidase activity, and ubiquinone content (P less than 0.05) but has no effect on endurance capacity. Exercise to exhaustion resulted in a significant (P less than 0.001) elevation of total and oxidized glutathione (GSSG) and a significant (P less than 0.05) decrease of vitamin E in plasma of control and selenium-deficient rats. Acute exercise also increased tissue GSSG levels in both control and selenium-deficient groups of rats. Hence, despite a large depletion of selenium-deficient glutathione peroxidase, pronounced oxidation of glutathione to GSSG can be produced by the increased oxidative metabolism during physical exercise. The results suggest that the residual glutathione peroxidase activity is sufficient to detoxify hydroperoxides in exercising selenium-deficient animals and to prevent the impairment of endurance capacity.  相似文献   

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The V(D)J recombination, which leads to the somatic rearrangement of variable, diversity, and joining segments, is the mechanism accountable for the diversity of T cell receptor- and Ig-encoding genes. The products of the RAG1 and RAG2 genes are the lymphoid-specific factors responsible for the initiation of the V(D)J recombination through the generation of a DNA double strand break. RAG1 or RAG2 gene inactivation in the mouse leads to abortion of the V(D)J rearrangement process, early block in both T and B cell maturation, and, ultimately, to severe combined immune deficiency (SCID). A human SCID condition is also characterized by an absence of mature T and B lymphocytes and is associated with mutations in either RAG1- or RAG2-encoding genes. Based on the predicted beta-propeller three-dimensional structure model for RAG2, we found that six out of the seven mutations described to date in T-B-SCID patients are clustered on one side of the propeller, in regions exposed to solvent. This finding reinforces the biological significance of this predicted model and suggests that RAG1 interacts with RAG2 on one of the side of the scaffold formed by the beta-propeller.  相似文献   

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The nutritional status of plants from high altitudes   总被引:28,自引:0,他引:28  
Ch. Körner 《Oecologia》1989,81(3):379-391
Summary Are plants at high altitudes short in nutrients? In order to answer this question the mineral nutrient content of leaves from over 150 plant species from 9 different mountain areas of all major climatic zones were analyzed (Kjeldahl nitrogen in all, phosphate in half of the samples, K, Mg, Mn, Ca in the Alps only). The majority of data are from herbaceous perennials, but shrubs and trees were studied as well. N-partitioning was studied in 45 herbaceous species from contrasting altitudes in the Alps. The survey falls into three categories: (1) comparisons of whole communities of species from contrasting altitudes, (2) analysis of altitudinal gradients, and (3) additional collections from high altitude sites alone. Unlike the other mineral nutrients, nitrogen content follows consistent altitudinal and latitudinal trends. The higher altitude sample always had higher N content per unit leaf area, irrespective of life form, wherever comparable plants (the same or related species) were investigated at contrasting altitudes. N content per unit dry weight (%) increased with altitude in herbaceous plants (in some species >4%), but was remarkably stable in evergreen woody plants (around 1%). The mean fraction of total plant N allocated to leaves of herbaceous plants in the Alps was the same at low and high altitude (1/3 of total). Leaf N (%) from the regional upper limits of higher plant life reveals a latitudinal decrease from subarctic to equatorial mountains, which may be related to the duration of annual leaf activity. Since mean N content per leaf area hardly differs between the uppermost sites, life span expectation (sink-duration) seems to control carbon investments rather than N input per leaf area. The growth of leaves at high altitude seems to be controlled in a way that leads to comparatively high nutrient contents, which in turn support high metabolic activity. Inherent developmental growth constraints inhibit nutrient dilution in the plant body and thus defy the application of classical concepts of plant-nutrient versus soil-nutrient relations developed for lowlands and in particular for cultivated plants. The results re-emphasize the global significance of links between nitrogen content, leaf sclerophylly, leaf longevity and photosynthetic capacity.Dedicated to Prof. Walter Larcher on the occasion of his 60th birthday, with thanks for leading me to comparative plant ecology  相似文献   

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A process unique to lymphocyte differentiation is the rearrangement of genes encoding antigen-specific receptors on B and T cells. A mouse mutant (C.B-17scid) with severe combined immune deficiency, i.e., that lacks functional B and T cells, shows no evidence of such gene rearrangements. However, rearrangements were detected in Abelson murine leukemia virus-transformed bone marrow cells and in spontaneous thymic lymphomas from C.B-17scid mice. Most of these rearrangements were abnormal: approximately 80% of Igh rearrangements deleted the entire Jh region, and approximately 60% of TCR beta rearrangements deleted the entire J beta 2 region. The deletions appeared to result from faulty D-to-J recombination. No such abnormal rearrangements were detected in transformed tissues from control mice. The scid mutation may adversely affect the recombinase system catalyzing the assembly of antigen receptor genes in developing B and T lymphocytes.  相似文献   

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Ginkgo biloba is one of the most popular herb nutrition supplements, with terpene lactones and flavonoids being the two major active components. A fingerprint profile method was developed using a capillary HPLC/MS method which can identify more than 70 components from the G. biloba product. The method allows the flavonoids and terpene lactones to be detected simultaneously and information of both the parent ion and its fragmentation can be obtained in just one HPLC/MS run. Targeted post-acquisition analysis allows mass spectrometric information regarding the identification of flavonoid components to be easily distinguished from other data, however the same approach for terpene lactones was less successful due to dimer formation and requires further development. The fingerprint profiles of five commercial G. biloba nutritional supplements were obtained and compared; variation of some components among the samples was observed and fortification could be detected. In the quality control analysis of the G. biloba product this method could be viewed as complementary to specific quantitative analysis of some bioactive components of the herb.  相似文献   

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The effect of two specific nutritional deficiencies upon activity in chickens was investigated. Groups of pullets deprived of calcium in large cages showed significant increases in spontaneous activity; both as measured by complete body movements and also as pecking activity. Deprived birds, but not controls, were observed engaging in an aberrant behaviour pattern, ‘air pecking’. When the response of birds to various stimulus objects in an arena was tested, calcium deprivation resulted in significantly increased pecking activity, but it was not preferentially directed towards a potential calcium source and the pattern of pecking was similar to that observed in the controls. It did not prove possible to relate this increased activity to raised parathyroid hormone levels, and the fact that a similar increase in activity was seen under sodium deprivation suggests that the phenomenon may be of more general occurrence.  相似文献   

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Milk urea nitrogen (UN) concentration was examined as a possible index to protein-energy intake in female collared peccaries (Tayassu tajacu). Captive adults were bred and assigned to one of four experimental diets through gestation and lactation. Females fed a high protein diet produced milk with UN concentrations exceeding those of low-protein-fed females. A low energy intake tended to elevate UN concentrations in milk.  相似文献   

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Plasmodium falciparum malaria causes 1-2 million deaths per year. Most deaths occur as a result of complications such as severe anemia and cerebral malaria (CM) (coma). Red cells of children with severe malaria-associated anemia (SMA) have acquired deficiencies in the complement regulatory proteins complement receptor 1 (CR1, CD35) and decay accelerating factor (DAF, CD55). We investigated whether these deficiencies affect the ability of erythrocytes to bind immune complexes (ICs) and regulate complement activation. We recruited 75 children with SMA (Hb < or = 6 g/dL) from the holoendemic malaria region of the Lake Victoria basin, western Kenya, and 74 age- and gender-matched uncomplicated malaria controls. In addition, we recruited 32 children with CM and 52 age- and gender-matched controls. Deficiencies in red cell CR1 and CD55 in children with SMA were accompanied by a marked decline in IC binding capacity and increased C3b deposition in vivo and ex vivo. Importantly, these changes were specific because they were not seen in red cells of children with CM or their controls. These data suggest that the declines in red cell CR1 and CD55 seen in children with SMA are of physiologic significance and may predispose erythrocytes to complement-mediated damage and phagocytosis in vivo.  相似文献   

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The physiological effects and efficacy of dietary intake of antioxidant supplements in humans remains controversial. Experiments involving dietary, often high, intake of a single antioxidant or vitamin may be seriously flawed given the interactive nature of antioxidants in vivo. The present studies were conducted on individuals (35-60 years of age) taking a commercial antioxidant mixture in a double-blind, placebo-controlled, cross-over study. Intake was two capsules per day, for 4 weeks, with a 4-week washout period in between active dose or placebo. Intake of antioxidants was associated with little change in superoxide dismutase activity, but an increase in glutathione peroxidase was noted. Haemolysis of red blood cells (erythrocytes) induced by the free radical generator AAPH was significantly reduced in individuals on antioxidant supplements. In lymphocytes isolated from individuals taking supplements, there was a marked increase, as compared with individuals on placebo, in the synthesis of heat shock protein 70 (hsp70) following heat shock from 37 degrees C to 42.5 degrees C. We conclude that dietary intake of a mixed antioxidant supplement leads to modulation of cellular redox status resulting in decreased oxidative stress and increased ability of lymphocytes to mount a stress response.  相似文献   

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