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181.
Walker 256 tumour-bearing rats were fed pelleted chow containing low-gamma-linolenic acid (GLA) (2.98%) or high-GLA (5.55%) during the twelve-day period after subcutaneous implantation of the tumour. The presence of n-6, polyunsaturated GLA in the diet caused a concentration-dependent decrease in tumour growth, reaching an almost 50% reduction in final tumour weight in the high-GLA group. The eicosatrienoic acid content of the whole tumour homogenate and of the Percoll-purified mitochondrial fraction was increased by the GLA-rich diets. Changes in the fatty acid composition of the cytoplasmic acyl CoA pool were also found, with increases in GLA content in both the low- and high-GLA groups. Additionally, increases in eicosatrienoic acid and arachidonic acid were found in the high-GLA group. Both the cytoplasmic acyl CoA content and the mitochondrial acyl CoA synthetase activity were increased by GLA in the diet and lipid peroxidation was also increased as determined by an increase in TBARS content. Changes in mitochondrial fatty acid composition were accompanied by a decrease in the mitochondrial membrane potential in the high-GLA group. Tumours from the control and GLA groups were examined by transmission electron microscopy. This revealed an increase in mitochondrial area and volume in the high-GLA group, in comparison with the control group, as well as a change in general cell ultrastructure, with many cells found in an apoptotic state or in a necrotic state, possibly secondary to apoptosis. The data presented show that the addition of GLA to the diet of Walker 256 tumour-bearing rats can greatly decrease the rate of development of the tumour burden. This may be, in part, due to the accumulation of poorly metabolised acyl CoA's within the tumour cell cytoplasm which, when coupled with altered mitochondrial composition, membrane potential and ultrastructure, may be a signal for cell death.  相似文献   
182.
As a part of a composite programme of rational drug design (RDD), we had synthesized some substituted benzenesulphonyl glutamines and evaluated their inhibitory activities against Ehrlich Ascites Carcinoma (EAC) cell line in Swiss albino mice. Quantitative structure activity relationship (QSAR) studies of these inhibitory activities using Fujita-Ban model as well as Modified Hansch-Fujita model gave excellent correlations (correlation coefficient r = 0.89 and 0.82 respectively). These results could be useful in designing 'lead' compound with potent inhibitory activity on DNA and RNA synthesis and tumour development.  相似文献   
183.
A protein has been purified from rat liver cytosol which promoted GSH-responsive iodothyronine 5'-deiodinase activities in rat kidney microsomes. The factor behaved as a basic protein with an Mr of 11,000. It was active as a GSH-disulfide transhydrogenase with beta-hydroxyethyl disulfide as an acceptor and was also active in stimulating calf thymus ribonucleotide reductase with one-third the potency of native calf thymus glutaredoxin. Another basic protein, which degraded iodothyronines oxidatively, was also identified in the cytosolic preparations; this co-purified with soluble protein factor in the earlier purification stages and was partially separated from this factor by CM-cellulose chromatography. The glutaredoxin-like protein present in rat liver and kidney cytosol could provide a physiologic regulatory mechanism for GSH-dependent 5'-monodeiodination of iodothyronines.  相似文献   
184.
Studies of the nutritional requirements of a neomycin-producing mutantStreptomyces fradiae H developed by the authors show that tapioca starch (at a concentration of 5%) is an excellent carbon source for antibiotic production while soya flour and yeast powder are superior nitrogen sources for neomycin production. A mixture of 1% soya flour and 1% yeast powder gives maximal antibiotic titer.  相似文献   
185.
The objective of this study was to investigate Cd phytoremediation ability of Indian mustard, Brassica juncea. The study was conducted with 25, 50, 100, 200 and 400 mg Kg?1 CdCl2 in laboratory for 21 days and Cd concentrations in the root, shoot and leaf tissues were estimated by atomic absorption spectroscopy. The plant showed high Cd tolerance of up to 400 mg Kg?1 but there was a general trend of decline in the root and shoot length, tissue biomass, leaf chlorophyll and carotenoid contents. The tolerance index (TI) of plants were calculated taking both root and shoot lengths as variables. The maximum tolerance (TI shoot = 87.4 % and TI root = 89.6 %) to Cd toxicity was observed at 25 mg Kg?1, which progressively decreased with increase in dose. The highest shoot (10791 μg g?1 dry wt) and root (9602 μg g?1 dry wt) Cd accumulation was achieved at 200 mg kg?1 Cd treatment and the maximum leaf Cd accumulation was 10071.6 μg g?1 dry wt achieved at 100 mg Kg?1 Cd, after 21 days of treatment. The enrichment coefficient and root to shoot translocation factor were calculated, which, pointed towards the suitability of Indian mustard for removing Cd from soil.  相似文献   
186.
187.
A Completely Automated Public Turing test to tell Computers and Humans Apart (CAPTCHA) is designed to distinguish humans from machines. Most of the existing tests require reading distorted text embedded in a background image. However, many existing CAPTCHAs are either too difficult for humans due to excessive distortions or are trivial for automated algorithms to solve. These CAPTCHAs also suffer from inherent language as well as alphabet dependencies and are not equally convenient for people of different demographics. Therefore, there is a need to devise other Turing tests which can mitigate these challenges. One such test is matching two faces to establish if they belong to the same individual or not. Utilizing face recognition as the Turing test, we propose FR-CAPTCHA based on finding matching pairs of human faces in an image. We observe that, compared to existing implementations, FR-CAPTCHA achieves a human accuracy of 94% and is robust against automated attacks.  相似文献   
188.
Antimicrobial resistance continues to be an inexorable threat for the biomedical and biochemical researchers. Despite the novel discoveries in drug designing and delivery, high‐throughput screening and surveillance data render the prospects for new antimicrobial agents as bleak as ever. The advent of nanotechnology, however, strengthens pharmacology by offering effective therapeutics to treat this aforementioned problem. Several nanoparticles of the known elements have already been reported for their antimicrobial efficacy. Nanosized fabrication of elemental sulphur with suitable surface modifications offers to retrieve the use of sulphur (man's oldest known ecofriendly microbicide) as a potential antimicrobial agent. Sulphur nanoparticles (SNPs) are effective against both conventionally sulphur‐resistant and sulphur‐susceptible microbes (fungi and bacteria). Moreover, biocompatible polymers present on the surface of SNPs minimize toxicity during application. Here, we focus on various aspects of physicochemical features of SNPs and their biochemical interactions with microbes. The present review also illustrates the effects of SNPs on plants and animals in terms of cytotoxicity and biocompatibility.  相似文献   
189.
Heterochronic changes in the rate or timing of development underpin many evolutionary transformations. In particular, the onset and rate of bone development have been the focus of many studies across large clades. In contrast, the termination of bone growth, as estimated by suture closure, has been studied far less frequently, although a few recent studies have shown this to represent a variable, although poorly understood, aspect of developmental evolution. Here, we examine suture closure patterns across 25 species of carnivoran mammals, ranging from social‐insectivores to hypercarnivores, to assess variation in suture closure across taxa, identify heterochronic shifts in a phylogenetic framework and elucidate the relationship between suture closure timing and ecology. Our results show that heterochronic shifts in suture closure are widespread across Carnivora, with several shifts identified for most major clades. Carnivorans differ from patterns identified for other mammalian clades in showing high variability of palatal suture closure, no correlation between size and level of suture closure, and little phylogenetic signal outside of musteloids. Results further suggest a strong influence of feeding ecology on suture closure pattern. Most of the species with high numbers of heterochronic shifts, such as the walrus and the aardwolf, feed on invertebrates, and these taxa also showed high frequency of closure of the mandibular symphysis, a state that is relatively rare among mammals. Overall, caniforms displayed more heterochronic shifts than feliforms, suggesting that evolutionary changes in suture closure may reflect the lower diversity of cranial morphology in feliforms.  相似文献   
190.
The Puntius denisonii colloquially and more popularly referred to as Miss Kerala is a subtropical fish belonging to the genus Puntius (Barb) and family Cyprinidae. Two cell lines PDF and PDH were developed from the caudal fin and heart of P. denisonii, respectively. The cell lines were optimally maintained at 26°C in Leibovitz-15 medium supplemented with 10% fetal bovine serum. A diploid count of 50 chromosomes at passage 50 was observed in both the cell lines. The high growth potential of the cell lines was reflected from the cell doubling time of 28 and 30?h of PDF and PDH cell lines, respectively. The viability of the PDF and PDH cell lines was 70% and 76%, respectively, after 4?mo of storage in liquid nitrogen (-196°C). The origin of the cell lines was confirmed by the amplification of 653?bp fragments of cytochrome oxidase subunit I of mitochondrial DNA genes.  相似文献   
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