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41.
We have examined the effect of sodium butyrate (SB) on the viability of normal peripheral blood lymphocytes (PBLs) in vitro and the effect of this agent on the expression of 20 apoptosis-related genes. Data suggest that PBL treated with 2 mmol L(-1) SB resisted for at least 8 h the destructive activity of the agent, but eventually 30% of cells died within 72 h. As documented by flow cytometry and cytochrome c release study, cells underwent mitochondrial-derived apoptosis. While the expression of the majority of genes examined by RT-PCR and Western blots remained indifferent to 2 mmol L(-1) SB, the cellular levels of BimEL, c-myc, p53, and p21(WAF1) varied profoundly with the time of SB treatment. The Bax activator BimEL increased rapidly, driving cells toward apoptosis likely controlled by c-myc and p21(WAF1) activities. The c-myc, exercising the role of mediator of the function of BimEL and inhibitor of p21(WAF1) expression, decreased significantly for several hours after adding SB but within 48 h it returned to close to its original value. An apoptosis inhibitor and executive caspase substrate p21(WAF1) increased early at the beginning of treatment but subsequently, within a time frame of 72 h, profoundly dropped in terms of both a caspase-dependent and caspase-independent way. We suggest that variations in c-myc and p21(WAF1) expression delay apoptosis making PBL resistant to SB for several hours, and together with fast catabolism of SB in vivo protect PBL against the destructive activity of this anti-cancerous metabolite of colonic bacteria.  相似文献   
42.
The aim of this study was to investigate the effect of the microsomal triglyceride transfer protein (MTP) -493G/T polymorphism on clinical and biochemical parameters in relation to the presence of metabolic syndrome (MS). A group of 270 participants, 143 men and 127 women [50 men/36 women fulfilled the International Diabetes Federation (IDF) criteria of MS], was categorized on the basis of the MTP -493G/T polymorphism: GG homozygotes (Group GG) and carriers of the T allele (Group TT+TG). In men with MS, the presence of the T allele was associated with elevated concentrations of plasma insulin (by 48%, P<.01) and nonesterified fatty acids (by 49%, P<.05); homeostasis model assessment for insulin resistance index was higher by 64% (P<.05). Carriers of the T allele were further characterized by elevated plasma concentrations of total cholesterol (by 14%, P<.05) and by increased triglycerides in plasma (by 95%, P<.01) and in very low-density lipoprotein (by 106%, P<.01). They also had lower concentrations of n-6 polyunsaturated fatty acids in plasma phospholipids (by 3.5%, P<.05), lower Delta5-desaturase activities (by 18%, P<.05) and elevated concentrations of conjugated dienes in low-density lipoprotein (by 29%, P<.01). No significant differences between Groups GG and TT+TG were found in men without MS and in women with and without MS. Our results imply evidence for interactive effects of genetic, metabolic and gender-specific factors on several components of metabolic syndrome, which can increase the risk for cardiovascular disease.  相似文献   
43.
Characterization of cellulosic fibers and fabrics by sorption/desorption   总被引:2,自引:0,他引:2  
Three cellulosic substrates: lyocell (CLY), viscose (CV), and modal (CMD) in the form of fibers and fabrics were subjected to wet/dry or wash/dry treatments. The accessibility of untreated and treated substrates to water and iodine was investigated using dynamic water-vapor sorption, moisture retention, and iodine sorption methods, to study the influence of treatments on sorption-desorption hysteresis, fraction of moisture sorbed as a monomolecular layer, water retention, and iodine sorption. It was found that the sorption properties of untreated and treated substrates differed with sorbate type as well as substrate type and form.  相似文献   
44.
Traditional quantitative genetics assumes that an individual''s phenotype is determined by both genetic and environmental factors. For many animals, part of the environment is social and provided by parents and other interacting partners. When expression of genes in social partners affects trait expression in a focal individual, indirect genetic effects occur. In this study, we explore the effects of indirect genetic effects on the magnitude and range of phenotypic values in a focal individual in a multi-member model analyzing three possible classes of interactions between individuals. We show that social interactions may not only cause indirect genetic effects but can also modify direct genetic effects. Furthermore, we demonstrate that both direct and indirect genetic effects substantially alter the range of phenotypic values, particularly when a focal trait can influence its own expression via interactions with traits in other individuals. We derive a function predicting the relative importance of direct versus indirect genetic effects. Our model reveals that both direct and indirect genetic effects can depend to a large extent on both group size and interaction strength, altering group mean phenotype and variance. This may lead to scenarios where between group variation is much higher than within group variation despite similar underlying genetic properties, potentially affecting the level of selection. Our analysis highlights key properties of indirect genetic effects with important consequences for trait evolution, the level of selection and potentially speciation.  相似文献   
45.
Seed dispersal is a crucial process for the dynamics and maintenance of plant populations. Free-ranging animals are effective dispersal vectors because they can move between similar habitats and transport seeds into favourable environments. Dung samples from two species of common free-ranging mammals—deer and wild boar—were used to study endozoochorous dispersal of seeds in a military training area in western Bohemia. The area was abandoned after WWII, and the military training area was established in 1953. The vegetation consists of shrublands and dry grasslands. Data on the local species pool of grassland herbs and forbs were collected to compare the characteristics of dispersed versus non-dispersed plants. Deer and wild boar dispersed 84 plant species; however, species composition of seedlings emerging from dung samples showed significant differences between dispersal vectors and notable change across the growing season. 80% of all seedlings extracted from the dung samples belonged to stinging nettle, Urtica dioica. From trait analyses, seeds of endozoochorous plants had a higher longevity index in the soil seed bank than non-endozoochorous plants and more often possessed a mucilaginous surface. Our results show that deer and boar are successful, though not substitutable dispersers.  相似文献   
46.
47.
2016, was the 100 years anniversary from launching of the first industrial acetone-butanol-ethanol (ABE) microbial production process. Despite this long period and also revival of scientific interest in this fermentative process over the last 20 years, solventogenic clostridia, mainly Clostridium acetobutylicum, Clostridium beijerinckii, Clostridium saccharoperbutylacetonicum and Clostridium pasteurianum, still have most of their secrets. One such poorly understood mechanism is butanol tolerance, which seems to be one of the most significant bottlenecks obstructing industrial exploitation of the process because the maximum achievable butanol concentration is only about 21 g/L. This review describes all the known cellular responses elicited by butanol, such as modifications of cell membrane and cell wall, formation of stress proteins, extrusion of butanol by efflux pumps, response of regulatory pathways, and also maps both random and targeted mutations resulting in high butanol production phenotypes. As progress in the field is inseparably associated with emerging methods, enabling a deeper understanding of butanol tolerance and production, progress in these methods, including genome mining, RNA sequencing and constructing of genome scale models are also reviewed. In conclusion, a comparative analysis of both phenomena is presented and a theoretical relationship is described between butanol tolerance/high production and common features including efflux pump formation/activity, stress protein production, membrane modifications and biofilm growth.  相似文献   
48.
Mental health problems are a major public health issue worldwide, and zinc may be associated with psychiatric symptoms, but such associations have not been investigated extensively. This study was conducted to evaluate the relationship between serum zinc levels and mental health problems in Korean adults. We used data from the Korean National Health and Nutrition Examination Survey V-1, a cross-sectional survey of Korean civilians. Data from 1748 subjects were analyzed. Serum zinc levels did not differ significantly according to psychiatric symptoms including sleep duration, stress, depressed mood, suicidal ideation, and whether respondents sought psychiatric consultation. The frequencies and odds ratios of psychiatric symptoms according to serum zinc tertiles were not significantly associated after adjusting for age, smoking, alcohol consumption, physical activity, body mass index, total body fat, and renal function and for daily fat, carbohydrate, and protein intake. Serum zinc levels may not be associated with psychiatric symptoms in Korean adults without psychiatric disorders.  相似文献   
49.
Dwarf pine (Pinus mugo) is a shrubby, polycormon-forming woody light-demanding species in the Central-European mountains, but it is non-native in the Jeseniky Mts. (the Hercynian Mts., the Czech Republic). Dwarf pine was introduced there at the nineteenth century, and its range expansion was the reason for the removal of this species by a small-scale clear-cut (locality Keprnik Mt.). The effect of the clear-cutting was recorded by means of phytosociological relevés, and three distinct habitats (alpine grasslands, dwarf pine plantation, clear-cut) were compared 6 years after the dwarf pine removal. On the clear-cut area, the highest species diversity was documented, invasive species were missing there, but plant composition remained transitional and expansive graminoids prevailed. Vegetation shifts denoted environmental changes that were attributed to post-management processes and particular plant attributes. That should be taken into account when planning future large-scale management.  相似文献   
50.
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