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41.
Todorov SD Botes M Guigas C Schillinger U Wiid I Wachsman MB Holzapfel WH Dicks LM 《Journal of applied microbiology》2008,104(2):465-477
Aims: To evaluate the probiotic properties of strains isolated from boza, a traditional beverage produced from cereals. Methods and Results: The strains survived low pH conditions (pH 3·0), grew well at pH 9·0 and were not inhibited by the presence of 0·3% (w/v) oxbile. Cytotoxicity levels of the bacteriocins, expressed as CC50, ranged from 38 to 3776 μg ml?1. Bacteriocin bacST284BZ revealed high activity (EC50 = 735 μg ml?1) against herpes simplex virus type 1. Growth of Mycobacterium tuberculosis was 69% repressed after 5 days in the presence of bacST194BZ. Various levels of auto‐cell aggregation and co‐aggregation with Listeria innocua LMG 13568 were observed. Adhesion of the probiotic strains to HT‐29 cells ranged from 18 to 22%. Conclusions: Boza is a rich source of probiotic lactic acid bacteria. All strains survived conditions simulating the gastrointestinal tract and produced bacteriocins active against a number of pathogens. Adherence to HT‐29 and Caco‐2 cells was within the range reported for Lactobacillus rhamnosus GG, a well‐known probiotic. In addition, the high hydrophobicity readings recorded define the strains as good probiotics. Significance and Impact of the Study: Boza contains a number of different probiotic lactic acid bacteria and could be marketed as a functional food product. 相似文献
42.
Kirk A. Moloney Claus Holzapfel Katja Tielbrger Florian Jeltsch Frank M. Schurr 《Perspectives in Plant Ecology, Evolution and Systematics》2009,11(4):311-320
In common garden experiments, a number of genotypes are raised in a common environment in order to quantify the genetic component of phenotypic variation. Common gardens are thus ideally suited for disentangling how genetic and environmental factors contribute to the success of invasive species in their new non-native range. Although common garden experiments are increasingly employed in the study of invasive species, there has been little discussion about how these experiments should be designed for greatest utility. We argue that this has delayed progress in developing a general theory of invasion biology. We suggest a minimum optimal design (MOD) for common garden studies that target the ecological and evolutionary processes leading to phenotypic differentiation between native and invasive ranges. This involves four elements: (A) multiple, strategically sited garden locations, involving at the very least four gardens (2 in the native range and 2 in the invaded range); (B) careful consideration of the genetic design of the experiment; (C) standardization of experimental protocols across all gardens; and (D) care to ensure the biosafety of the experiment. Our understanding of the evolutionary ecology of biological invasions will be greatly enhanced by common garden studies, if and only if they are designed in a more systematic fashion, incorporating at the very least the MOD suggested here. 相似文献
43.
Raphaël Plasson Maika Tsuji Masazumi Kamata Kouichi Asakura 《Origins of life and evolution of the biosphere》2011,41(5):413-435
A good comprehension of the reactivity of peptides in aqueous solution is fundamental in prebiotic chemistry, namely for understanding
their stability and behavior in primitive oceans. Relying on the stereoselectivity of the involved reactions, there is a huge
interest in amino acid derivatives for explaining the spontaneous emergence of homochirality on primitive Earth. The corresponding
kinetic and thermodynamic parameters are however still poorly known in the literature. We studied the reactivity of alanylalanine
in acidic to neutral conditions as a model system. The hydrolysis into amino acids, the epimerization of the N-terminal residue,
and the cyclization into diketopiperazine could be successfully identified and studied. This kinetic investigation highlighted
interesting behaviors. Complex mechanisms were observed in very acidic conditions. The relative kinetic stability of the diastereoisomers
of the dipeptide is highly dependent of the pH, with the possibility to dynamically destabilize the thermodynamically more
stable diastereoisomers. The existence of the cyclization of dipeptides adds complexity to the system. On one hand it brings
additional stereoselectivities; on the other hand fast racemization of heterochiral dipeptides is obtained. 相似文献
44.
45.
J. Tong T. Cohnert P. Regitnig J. Kohlbacher R. Birner-Gruenberger A.J. Schriefl G. Sommer G.A. Holzapfel 《Journal of biomechanics》2014
Introduction
Thrombus ages, defined as four relative age phases, are related to different compositions of the intraluminal thrombus (ILT) in the abdominal aortic aneurysm (AAA) (Tong et al., 2011b). Experimental studies indicate a correlation between the relative thrombus age and the strength of the thrombus-covered wall.Methods
On 32 AAA samples we performed peeling tests with the aim to dissect the material (i) through the ILT thickness, (ii) within the individual ILT layers and (iii) within the aneurysm wall underneath the thrombus by using two extension rates (1 mm/min, 1 mm/s). Histological investigations and mass fraction analysis were performed to characterize the dissected morphology, to determine the relative thrombus age, and to quantify dry weight percentages of elastin and collagen in the AAA wall.Results
A remarkably lower dissection energy was needed to dissect within the individual ILT layers and through the thicknesses of old thrombi. With increasing ILT age the dissection energy of the underlying intima–media composite continuously decreased and the anisotropic dissection properties for that composite vanished. The quantified dissection properties were rate dependent for both tissue types (ILT and wall). Histology showed that single fibrin fibers or smaller protein clots within the ILT generate smooth dissected surfaces during the peeling. There was a notable decrease in mass fraction of elastin within the thrombus-covered intima–media composite with ILT age, whereas no significant change was found for that of collagen.Conclusions
These findings suggest that intraluminal thrombus aging leads to a higher propensity of dissection for the ILT and the intima–media composite of the aneurysmal wall. 相似文献46.
G L Nortjé L Nel E Jordaan K Badenhorst E Goedhart W H Holzapfel 《The Journal of applied bacteriology》1990,68(4):335-344
At a city abattoir, a wholesaler and 10 different supermarkets, surface microbiological samples were taken of carcasses, hands and apron fronts of members of staff and equipment (mincers and saws). In addition, minced meat, packaged and displayed in chilled cabinets, was also sampled. Carcasses, personnel surfaces and equipment were monitored by a modified agar sausage technique. From each of the highest dilution psychotrophic plate counts, five colonies were selected randomly, isolated and identified (1265 in total). Microbes developing on chilled meat were also isolated from other surfaces in the production chain. On chilled meat (51%) and at the abattoir (36%) pseudomonads were the predominant organisms followed by the Gram-positive cocci on chilled meat and by Acinetobacter, Moraxella and Alcaligenes spp. at the abattoir. At the wholesaler Gram-positive cocci (32%) predominated, followed by Alcaligenes, Moraxella and Alcaligenes spp. Pseudomonas, Alcaligenes, Neisseriaceae and related genera, Gram-positive cocci, species from the coryneform groups of bacteria and yeasts were identified from all the surfaces monitored. Identification with the API NE20 was unsatisfactory. Enterbacteriaceae, lactobacilli and endospore-forming bacteria were identified occasionally, but their significance as contaminating organisms seems low. No Salmonella spp. were identified. 相似文献
47.
UDP-induced relaxation is enhanced in aorta from female obese Otsuka Long–Evans Tokushima Fatty rats
Shota Kobayashi Takayuki Matsumoto Makoto Ando Maika Iguchi Shun Watanabe Kumiko Taguchi Tsuneo Kobayashi 《Purinergic signalling》2018,14(1):91-96
Uridine 5′-diphosphate (UDP) plays an important role in controlling vascular tone; however, UDP-mediated response in metabolic syndromes, including obesity and type 2 diabetes in females, remains unclear. In this study, we investigated UDP-mediated response in the aorta of female obese Otsuka Long–Evans Tokushima Fatty (OLETF) rats and control Long–Evans Tokushima Otsuka (LETO) rats. In OLETF rat aortas precontracted by phenylephrine (PE) (vs. LETO), (1) UDP-induced relaxation was increased, whereas acetylcholine (ACh)-induced relaxation was decreased; (2) no UDP- or ACh-induced relaxations were observed in endothelial denudation, whereas UDP-induced small contraction was observed; and (3) NG-nitro-L-arginine [L-NNA, a nitric oxide (NO) synthase inhibitor] eliminated UDP-induced relaxation and small contraction, whereas caused contrasting responses by ACh, including slight relaxations (LETO) and contractions (OLETF). Indomethacin, a cyclooxygenase inhibitor, eliminated the difference in UDP- and ACh-induced relaxations between the groups by increased UDP-induced relaxation in the LETO group and increased ACh-induced relaxation in the OLETF group. MRS2578, a P2Y6 receptor antagonist, eliminated the difference in UDP-induced relaxations between the groups by decreasing UDP-induced relaxation in the OLETF group. MRS2578 had no effect on UDP-induced contraction in endothelium-denuded aortas. Therefore, these findings demonstrate opposite trends of relaxations by UDP and ACh in OLETF and LETO rat aortas. These differences may be attributed to the imbalance between NO and vasoconstrictor prostanoids upon stimulations. Increased UDP-induced relaxation in OLETF rat aorta may be caused by the activation of endothelial MRS2578-sensitive P2Y6 receptor. 相似文献
48.
Features and Trajectories of Eating Behavior in Weight‐Loss Maintenance: Results from the German Weight Control Registry
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Maria Neumann Christina Holzapfel Astrid Müller Anja Hilbert Ross D. Crosby Martina de Zwaan 《Obesity (Silver Spring, Md.)》2018,26(9):1501-1508
Objective
Eating behaviors such as dietary restraint and disinhibition caused by emotional and external cues play a relevant role in weight‐loss maintenance.Methods
Four hundred forty individuals with successful weight‐loss maintenance included in the prospective German Weight Control Registry completed the Dutch Eating Behavior Questionnaire. Participants were categorized into the following two weight groups: stable weight trajectory (WS) (n = 280) and unstable weight trajectory (WUS) (n = 160) over the 2‐year assessment period.Results
Those with successful weight‐loss maintenance had significantly higher scores on the restrained and emotional eating subscales compared with a general population (GP) sample. At baseline, the WS individuals had lower restrained, emotional, and external eating scores compared with the WUS individuals. Over the 2‐year follow‐up period, the trajectories of the restraint scores decreased in both groups but stayed elevated compared with the GP sample. Scores of the emotional and external eating subscales remained stable in the WS group but increased in the WUS group.Conclusions
A certain degree of restraint seems to be necessary for successful weight‐loss maintenance; however, high emotional and external eating may counteract this effect, resulting in weight regain in the long run. 相似文献49.
Min-Seok Kim Bobae Kim Haryung Park Yosep Ji Wilhelm Holzapfel Do-Young Kim Chang-Kee Hyun 《Biochemical and biophysical research communications》2018,495(2):1744-1751
Recently, Korean traditional fermented soybean paste, called Doenjang, has attracted attention for its protective effect against diet-related chronic diseases such as obesity and type 2 diabetes. Long-term fermented soybean pastes (LFSPs) are made by fermentation with naturally-occurring microorganisms for several months, whereas short-term fermented soybean pastes (SFSPs) are produced by shorter-time fermentation inoculated with a starter culture. Here, we demonstrate that administration of LFSP, but not SFSP, protects high-fat diet (HFD)-fed obese mice against non-alcohol fatty liver disease (NAFLD) and insulin resistance. LFSP suppressed body weight gain in parallel with reduction in fat accumulation in mesenteric adipose tissue (MAT) and the liver via modulation of MAT lipolysis and hepatic lipid uptake. LFSP-treated mice also had improved glucose tolerance and increased adiponectin levels concomitantly with enhanced AMPK activation in skeletal muscle and suppressed expression of pro-inflammatory cytokines in skeletal muscle and the liver. LFSP also attenuated HFD-induced gut permeability and lowered serum lipopolysaccharide level, providing an evidence for its probiotic effects, which was supported by the observation that treatment of a probiotic mixture of LFSP-originated Bacillus strains protected mice against HFD-induced adiposity and glucose intolerance. Our findings suggest that the intake of LFSP, but not SFSP, offers protection against NAFLD and insulin resistance, which is an effect of long-term fermentation resulting in elevated contents of active ingredients (especially flavonoids) and higher diversity and richness of Bacillus probiotic strains compared to SFSP. 相似文献
50.
Cedric W. Holzapfel Ben-Erik Van Wyk Antonio De Castro Wilhelmina Marais Madrie Herbst 《Biochemical Systematics and Ecology》1995,23(7-8):799-803
Lipophilic extracts from the roots of 16 species of Alepidea were studied by GC-MS for the presence of kaurenoic acids, dehydrokaurenoic acids, kaurenic lactones, hydroxykaurenoic acids and other kaurene derivatives. Various mixtures of these compounds are present in yields of up to 11.8% dry wt. in the rhizomes and roots. Two different isomers of kaurenoic acid occur in Alepidea, the one as a major compound in all the species, the other as a major compound only in some of them. The first isomer is clearly a useful chemical marker for the genus Alepidea, but the apparent chemical dichotomy is not obviously correlated with morphological patterns. Alepidea amatymbica, however, is part of a morphologically isolated group within the genus and also differs from other species in its chemical complexity and in the unique presence of kaurenoic lactones. 相似文献