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1.
Recovery of Cell-Bound Interferon   总被引:5,自引:2,他引:3       下载免费PDF全文
Interferon could be recovered from homologous cells to which it was applied but could not be recovered from heterologous cells. The amount of interferon that could be recovered from cells corresponded to the sensitivity of the cells to the antiviral activity of the interferon: mouse embryo fibroblasts, which were 5 to 10 times as sensitive as L-929 cells to interferon, bound 5 to 10 times more interferon than the latter, whereas Lpa cells, which were only one-third as sensitive as L-929 cells to interferon, bound only one-third as much as the latter. The concentration of cell-bound interferon was as much as 150 times the extracellular concentration of interferon applied to the cells. Interferon bound to cells at 4 C with the same efficiency as it did to cells at 37 C, and actinomycin D-treated cells bound interferon as well as normal cells. Even though the total amount of interferon bound to cells was as much as 30% of the amount of interferon applied to them, no loss of antiviral activity was detectable from the medium.  相似文献   

2.
农牧结合生态工程的基本理论与实践   总被引:6,自引:0,他引:6  
农牧结合生态工程是一个复杂的农业生态、经济和技术系统工程,它由植物(种植业)、动物(养殖业)和微生物(连接种养业)3个子系统组成,其关键是建设一个以"四、三、二、一"畜牧业生产模式为主要内容的高效节粮型畜牧生态工程,它要求用尽可能少的自然资源,在尽可能短的周期内,生产尽可能多而优的农(牧)产品,以获取尽可能高的经济效益,达到或维持尽可能最佳的生态平衡.  相似文献   

3.
Tissue microarrays have become an essential tool in translational pathology. They are used to confirm results from other experimental platforms, such as expression microarrays, as well as a primary tool to explore the expression profile of proteins by immunohistochemical analysis. Tissue microarrays are routinely used molecular epidemiology, drug development and determining the diagnostic, prognostic and predictive value of new biomarkers. By applying traditional protein based assays, as well as novel assays to the platform, tissue microarrays have gained a new utility as a proteomic tool for both basic science as well as clinical investigation. This article will explore the new approaches that are being applied to tissue microarrays to, characterize the human proteome, and new technologies that allow tissue microarrays to function as a protein array. The U.S. Government's right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged  相似文献   

4.
A nonadecanucleotide has been used both as a site specific mutagen to introduce a T leads to A transversion mutation in the human beta-globin gene cloned in pBR322 as well as a probe to screen transformed colonies for the desired mutant. The specificity of the oligonucleotide as a mutagen and as a hybridization probe provide a general method for producing site specific mutations in DNA cloned in plasmid vectors such as pBR322.  相似文献   

5.
It has been more than 100 years since the realization that microbes are capable of causing disease. In that time, we have learned a great deal as to how each organism has adapted to the immune system so as to avoid elimination. As well, we have also learned an immense amount since Louis Pasteur first proposed that the solution to infectious diseases was to culture the microbes and attenuate their virulence, so as to use them as vaccines. From the optimism and promise of the 19th century and immunization as the ultimate answer to the invasion by the microbial world, to the scientific realities of the 21st century, it is of interest to retrace the steps of the earliest microbiologists cum immunologists, to realize how far we've come, as well as how far we yet have to go. This editorial focuses on the history of anthrax as a microbial disease, and the earliest efforts at producing a vaccine for its prevention.  相似文献   

6.
Variability in Race Tests with Heterodera glycines   总被引:1,自引:0,他引:1  
Tests of Heterodera glycines on differential host plants to determine races were run in Arkansas, Illinois, and North Carolina to check the uniformity of results of the test. Methods used at the three locations varied somewhat. Results indicate that the race test is highly variable. Isolates previously identified as race 1 were identified as race 1 or race 3; those identified as race 2 were identified in these tests as race 2, 4, 9, or 14; those previously identified as race 3 were identified as race 1 or race 3; those identified as race 4 were identified in these tests as race 4 or race 14; those previously identified as race 5 were identified as race 2; and those previously identified as race 6 were identified as race 1, 2, 4, 5, or 6. Part of the variability resulted from the use of differential host plants from different sources and part from nonstandard differential host plants. Other variations may be due to inability to obtain completely uniform inoculum or to recover all nematodes that penetrated.  相似文献   

7.
Industrial and biotechnological applications of laccases: a review   总被引:21,自引:0,他引:21  
Laccases have received much attention from researchers in last decades due to their ability to oxidise both phenolic and non-phenolic lignin related compounds as well as highly recalcitrant environmental pollutants, which makes them very useful for their application to several biotechnological processes. Such applications include the detoxification of industrial effluents, mostly from the paper and pulp, textile and petrochemical industries, use as a tool for medical diagnostics and as a bioremediation agent to clean up herbicides, pesticides and certain explosives in soil. Laccases are also used as cleaning agents for certain water purification systems, as catalysts for the manufacture of anti-cancer drugs and even as ingredients in cosmetics. In addition, their capacity to remove xenobiotic substances and produce polymeric products makes them a useful tool for bioremediation purposes. This paper reviews the applications of laccases within different industrial fields as well as their potential extension to the nanobiotechnology area.  相似文献   

8.
The SLX4/FANCP tumor suppressor has emerged as a key player in the maintenance of genome stability, making pivotal contributions to the repair of interstrand cross-links, homologous recombination, and in response to replication stress genome-wide as well as at specific loci such as common fragile sites and telomeres. SLX4 does so in part by acting as a scaffold that controls and coordinates the XPF–ERCC1, MUS81–EME1, and SLX1 structure-specific endonucleases in different DNA repair and recombination mechanisms. It also interacts with other important DNA repair and cell cycle control factors including MSH2, PLK1, TRF2, and TOPBP1 as well as with ubiquitin and SUMO. This review aims at providing an up-to-date and comprehensive view on the key functions that SLX4 fulfills to maintain genome stability as well as to highlight and discuss areas of uncertainty and emerging concepts.  相似文献   

9.
1,2,3,4-Tetra-O-acetyl-5-thio-D-ribopyranose as well as its 1-bromide were used as donors in the reaction with 4-cyano- and 4-nitrobenzenethiol, to give the corresponding thioglycosides in different anomeric ratios depending on the reaction conditions. Zemplén deacetylation afforded 4-cyanophenyl as well as 4-nitrophenyl 1,5-dithio-alpha- and beta-D-ribopyranosides, respectively. 1,3,4-Tri-O-acetyl-2-deoxy-5-thio-D-erythro-pentopyranose was synthesized from methyl 2-deoxy-D-erythro-pentofuranoside and was coupled with 4-cyano- and 4-nitrobenzenethiol to give anomeric mixtures from which 4-cyanophenyl as well as 4-nitrophenyl 1,5-dithio-beta-D-erythro-pentopyranosides were isolated after deacetylation. 1,4-Di-O-acetyl-2,3-dideoxy-5-thio-D-glycero-pentopyranose was obtained starting from 1,2,5,6-di-O-isopropylidene-D-mannitol and used as the donor in the glycosylation reaction with 4-cyano- and 4-nitrobenzenethiol. The resulting anomeric mixtures were separated to give, after deacetylation, 4-cyanophenyl as well as 4-nitrophenyl 2,3-dideoxy-1,5-dithio-beta-D-glycero-pentopyranosides. All of these thioglycosides showed significant antithrombotic activity on rats after oral administration.  相似文献   

10.
In this study proteins extracted from prepupae of Hermetia illucens, also known as black soldier fly, are investigated as promising base for a new type of bioplastics for agricultural purposes. Design of experiments techniques are employed to perform a rational study on the effects of different combination of glycerol as plasticizer, citric acid as cross-linking agent and distilled water as solvent on the capability of proteins to form a free-standing film through casting technique, keeping as fixed the quantity of proteins. Glycerol shows interesting properties as plasticizer contributing to the formation of homogenous and free-standing film. Moreover, mechanical and thermal characterizations are performed to estimate the effect of increasing amounts of proteins on the final properties and thickness of the specimens. Proteins derived from H. illucens can be successfully employed as base for bioplastics to be employed for agricultural purposes.  相似文献   

11.
Bacterial pneumonia in immunocompromised patients as well as elderly persons often becomes a life threatening disease, even when effective antibiotics are used extensively. In addition, the appearance of antibiotic-resistant bacteria in medical facilities as well as in patients requires another approach to treat such patients besides treatment with antibiotics. In this regard, green tea catechins, such as epigallocatechin gallate (EGCg), may be one of the potential agents for such purpose due to its possible potential immunomodulatory as well as antimicrobial activity. The studies by us showed that EGCg enhanced the in vitro resistance of alveolar macrophages to Legionella pneumophila infection by selective immunomodulatory effects on cytokine formation. Furthermore, the tobacco smoking-induced impairment of alveolar macrophages regarding antibacterial as well as immune activity was also recovered by EGCg treatment. These results indicate that EGCg may be a possible potential immunotherapeutic agent against respiratory infections in immunocompromised patients, such as heavy smokers.  相似文献   

12.
Qualitative dysnutrition (pure bottle-feeding) as well as quantitative dysnutrition (overnutrition as well as undernutrition) during the first trimenon of postnatal life was found to lead to long-lasting mental, psychic and/or physical ill-effects in the human. Females who were completely bottlefed during neonatal life showed significantly decreased school achievements as well as significantly decreased learning capacity and social adaptability at 16 years of age as compared to females who were purely breastfed or breast- plus bottlefed in neonatal life. Males who were artificially overfed during neonatal life also showed significantly decreased school achievements and significantly decreased learning capacity in adolescence as compared to males with normal weight development in neonatal life.  相似文献   

13.
Based on data from observations of 302 tree species at La Selva, Costa Rica, we tested a range of hypotheses about the relationship between flowering parameters such as time, frequency, and duration and ecological features such as successional status, habit, sexual systems, and pollen vectors with and without considering the effect of family membership. We predicted that early successional species would flower any time of the year, but species pollinated by different vectors as well as dioecious species would flower nonrandomly across seasons. However, there was little evidence that flowering time varied with successional status, pollen vectors, and sexual systems. As we predicted, supra-annual flowering was proportionately less common in early successional species as compared to late ones, in understory species as compared to canopy species, and in dioecious species as compared to those with hermaphroditic flowers. When considering phylogeny, however, supra-annual flowering in the understory was not as rare as predicted. Our prediction of longer flowering in the early successional species as compared to late successional species was also supported. Predictions about longer flowering of dioecious species as compared to hermaphroditic species and of species pollinated by generalist vectors as compared to the specialists were not supported, though there was a trend in the expected direction.  相似文献   

14.
The data from the Russian and foreign literature on the effects of brown seaweed-derived sulfated polysaccharides (fucoidans) used as potential vaccine adjuvants to enhance the anti-infection and anti-tumor immune response are discussed in the present review. Due to their low toxicity, high biocompatibility, safety, and good tolerability by macroorganisms, as well as their mechanisms of immunomodulatory activity, fucoidans can be considered as promising adjuvants to administer in the composition of prophylactic and therapeutic vaccines. Fucoidans are agonists to receptors of innate immunity and are potent inducers of the cellular and humoral immune response, which is an important factor to be taken into account in the development of vaccines against various pathogens, including viruses, as well as anti-tumor vaccines. The results of numerous studies in which sulfated polysaccharides were tested as components of experimental vaccines, as presented in this review, show that these substances can be used as safe and effective adjuvants.  相似文献   

15.
Acetate as the major by-product in industrial-scale bioprocesses with Escherichia coli is found to decrease process efficiency as well as to be toxic to cells, which has several effects like a significant induction of cellular stress responses. However, the underlying phenomena are poorly explored. Therefore, we studied time-resolved population heterogeneity of the E. coli growth reporter strain MG1655/pGS20PrrnBGFPAAV expressing destabilized green fluorescent protein during batch growth on acetate and glucose as sole carbon sources. Additionally, we applied five fluorescent stains targeting different cellular properties (viability as well as metabolic and respiratory activity). Quantitative analysis of flow cytometry data verified that bacterial populations in the bioreactor are more heterogeneous in growth as well as stronger metabolically challenged during growth on acetate as sole carbon source, compared to growth on glucose or acetate after diauxic shift. Interestingly, with acetate as sole carbon source, significant subpopulations were found with some cells that seem to be more robust than the rest of the population. In conclusion, following batch cultures population heterogeneity was evident in all measured parameters. Our approach enabled a deeper study of heterogeneity during growth on the favored substrate glucose as well as on the toxic by-product acetate. Using a combination of activity fluorescent dyes proved to be an accurate and fast alternative as well as a supplement to the use of a reporter strain. However, the choice of combination of stains should be well considered depending on which population traits to aim for.  相似文献   

16.
Reproductive records of 284 female rhesus monkeys housed in six multimale corrals at the California Primate Research Center were examined for the birth seasons 1977–1982 to determine possible associations between the probability of birth or live birth and female age, parity, origin, parturition in the previous season, infant birth date, and infant birth date in previous season. Multiple logistic regression analysis was used to identify and quantitate the effects of factors on the probability of birth or live birth, while controlling for the possibly confounding effects of other factors in the model. Females who had infants early in the previous season were 2.5 times as likely to give birth as those who had infants late in the previous season. Females with two or three previous births were 2.1 times as likely to give birth, and those with four or five previous births were 6.7 times as likely to give birth as were females with no or one previous birth. Controlling for other factors (age, parity, and timing of birth in the previous season), corralborn females were 3.3 times as likely to give birth as either wild-caught or domestic-born monkeys not native to the corrals. Domestic-born females who were not corral natives were 0.3 times as likely to have live births as wild-caught females. Births late in the season were 1.8 times as likely to result in live infants as births early in the season.  相似文献   

17.
The use of probiotics in shrimp aquaculture   总被引:1,自引:0,他引:1  
Shrimp aquaculture, as well as other industries, constantly requires new techniques in order to increase production yield. Modern technologies and other sciences such as biotechnology and microbiology are important tools that could lead to a higher quality and greater quantity of products. Feeding and new practices in farming usually play an important role in aquaculture, and the addition of various additives to a balanced feed formula to achieve better growth is a common practice of many fish and shrimp feed manufacturers and farmers. Probiotics, as 'bio-friendly agents' such as lactic acid bacteria and Bacillus spp., can be introduced into the culture environment to control and compete with pathogenic bacteria as well as to promote the growth of the cultured organisms. In addition, probiotics are nonpathogenic and nontoxic microorganisms without undesirable side-effects when administered to aquatic organisms. These strains of bacteria have many other positive effects, which are described in this article.  相似文献   

18.
The effects of 19-hydroxyprostaglandins (19-OH-PGs) were tested in vivo on the rabbit oviduct and uterus and on the rhesus monkey (Macaca mulatta) uterus. The 19-OH-PGEs suppressed spontaneous oviductal and uterine activity in the rabbit. The qualitative effect on the rabbit oviduct of 19-OH-PGEs was similar to that of PGE2. However, the typical response of the rabbit uterus to PGE2 was an increase in muscle activity. With regard to the rabbit oviduct, 19(R)-OH-PGE2 was as potent as PGE2, but 19(S)-OH-PGE2 was approximately 1/2 as potent as PGE2. Based on the dose of 19-OH-PGEs usually required to cause a minimal suppression and the dose of PGE2 required to cause a minimal stimulation of rabbit uterine activity, 19(R)-OH-PGE2 was twice as potent as PGE2 while 19(S)-OH-PGE2 was 1/2 as potent as PGE2. Stimulatory effects on the rabbit oviduct and uterus were observed following administration of 19-OH-PGFs and PGF2alpha. The potency on the rabbit oviduct of 19(S)-OH-PGF2alpha was about 1/5 to 1/10 that of PGF2alpha; the potency of 19(R)-OH-PGF2alpha was about 1/10 to 1/20 that of PGF2alpha. Both 19-OH-PGFs were approximately 1/5 to 1/10 as potent as PGF2alpha on the rabbit uterus. At the doses tested 19-OH-PGFs were inactive on the monkey uterus. Thus, these compounds are at least 1/5 as active as PGF2alpha. In contrast, 19(R)-OH-PGE2 had approximately the same potency as PGE2 in stimulating monkey uterine activity; but 19(S)-OH-PGE2 was approximately 1/3 as potent as PGE2.  相似文献   

19.
The toxicity as contact insecticides of the esters of (±)-3-methyl-2-allyl-cycfopent-3-en-4-ol-i-one with the natural (+ )-trans and with synthetic (±) -cis-trans-chrysaii- themum monocarboxylic acids has been compared with that of the natural pyrethrins. The comparison was carried out on five species of test-insects.
It was found that the figure for both the absolute and the relative toxicities of these compounds varied with the species used as test-subject.
The factors involved in this variation are discussed. The extremes of variation of relative toxicity for the compounds with the natural acid were from about one-eighth as toxic as the pyrethrum standard when the aphid Macrosiphum solanifolii was used as test subject to nearly four times as toxic as the standard with the larvae of the moth Plutella maculipennis. The fully synthetic material varied from about one-sixteenth as toxic as the standard to Macrosiphum solanifolii to nearly twice as toxic to the larvae of Plutella maculipennis. The compound with the natural acid was approximately twice as toxic as the fully synthetic material to three of the insect species, but the fully synthetic material was considerably more than half as toxic as the partially synthetic to the fourth test-species. It is pointed out that while it is widely recognized that large differences in relative toxicity may occur when the effect of chemicals of widely different structure and mechanism of action are compared on a number of different test-species, the fact that these differences may also occur with related chemicals with, presumably, a similar mechanism of action, has not been clearly stated.
Even when the differences in relative toxicity are taken into account, the two synthetic pyrethrin-like esters still show high insecticidal activity.
It seems reasonable to suppose from the results that economic commercial synthesis of pyrethrin-like insecticides is not impossible.  相似文献   

20.
An improved life table method.   总被引:1,自引:0,他引:1  
N Keyfitz  J Frauenthal 《Biometrics》1975,31(4):889-899
A life table estimates probabilities of surviving and of dying as well as death rates, as these would apply in a stationary population with the same underlying continuous mortality curve as the observed population. We have derived approximations to the probability of surviving that require no iteration, do not depend on graduation or interpolation, and appear to give as precise results as interpolated or iterated tables. On the side of theroy we show that methods due to T.N.E. Greville and to Reed and Merrell are special cases of our formula (3). The new approach is extended to cause-deleted tables and to multiple decrement.  相似文献   

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