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1.
This study represents the first molecular phylogeny for the Order Ephemeroptera. The analyses included 31 of the 37 families, representing approximately 24% of the genera. Fifteen families were supported as being monophyletic, five families were supported as nonmonophyletic, and 11 families were only represented by one species, and monophyly was not testable. The suborders Furcatergalia and Carapacea were supported as monophyletic while Setisura and Pisciforma were not supported as monophyletic. The superfamilies Ephemerelloidea and Caenoidea were supported as monophyletic while Baetoidea, Siphlonuroidea, Ephemeroidea, and Heptagenioidea were not. Baetidae was recovered as sister to the remaining clades. The mayfly gill to wing origin hypothesis was not supported nor refuted by these data. Mandibular tusks were supported as having at least one loss in Behningiidae and, together with the burrowing lifestyle, possibly two origins. The fishlike body form was supported as plesiomorphic for mayflies with multiple secondary losses. Topological sensitivity analysis was used as a tool to examine patterns concerning the stability of relationships across a parameter landscape, providing additional information that may not have been acquired otherwise. 相似文献
2.
The parameters involved in the action of beta-galactosidase (EC 3.2.1.23) (Escherichia coli) on allolactose, the natural inducer of lac operon in E. coli, were studied. At low allolactose concentrations only galactose and glucose were formed, while at high allolactose concentrations transgalactolytic oligosaccharides were also produced. Detectable amounts of lactose were not formed. The V and Km values (49.6 U/mg and 0.00120 M, respectively) indicated that allolactose is as good if not a better substrate of beta-galactosidase as lactose. The pH optimum with allolactose (7.8-7.9) as well as its activation by K+ (as compared to activation by Na+) were similar to the case with lactose as substrate. The alpha-anomer of allolactose was hydrolyzed about two times as rapidly as was the beta-anomer. 相似文献
3.
Westerlind U Hagback P Tidbäck B Wiik L Blixt O Razi N Norberg T 《Carbohydrate research》2005,340(2):221-233
Derivatives of lactose with the galactose ring substituents replaced by deoxy or acylamino functions were prepared. The 2'-, 3'-, 4'- and 6'-deoxy, 3'-acetamido and 3'-benzamido derivatives of phenyl 4-O-(beta-D-galactopyranosyl)-beta-D-glucopyranoside (phenyl beta-lactoside) were synthesized from disaccharide or monosaccharide precursors. The derivatives were tested as substrates for the N-acetylglucosaminyltransferase from Neisseria meningitidis, which uses lactosyl derivatives as acceptors and UDP-GlcNAc as the donor in a beta-(1-->3) glycosylation reaction. The 6'-deoxy derivative was nearly threefold as active as phenyl beta-lactoside, whereas the 2'- and 4'-deoxy derivatives were less active. The other derivatives were inactive, as expected. 相似文献
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5.
Kohtaro Asayama Sadaki Yokota Kazushige Dobashi Yasusuke Kawada Takaya Nakane Akira Kawaoi Shinpei Nakazawa 《Histochemistry and cell biology》1996,105(5):383-389
To determine the distribution of cellular glutathione peroxidase in rat lungs, the tissues were stained immunohistochemically. Quantitative analysis was performed in certain cell types of alveolar linings, after the ultrathin sections were stained by a postembedding immunogold technique. Immunoblot analysis revealed that homogenates of rat liver, heart, and lungs all gave a single band. Under the light microscope, the following tissues were stained intensely: epithelial cells, smooth muscle cells and glands of bronchi and bronchioles, type II alveolar cells, and alveolar macrophages. Under immunoelectron microscopy, type II alveolar cells and macrophages were abundant in mitochondria. The mitochondria, nucleus, and cytoplasm of macrophages were labeled almost twice as densely as the respective compartments of type II alveolar cells. Within cell types, the mitochondria were labeled twice as densely as the nuclei. The other particles were less than half as densely labeled as the nuclei. The labeling was slightly less dense in the cytoplasm than in the nucleus. The present study revealed that glutathione peroxidase occurred predominantly in the epithelial linings and metabolically active sites in rat lungs. The tissues that were previously found to be rich in superoxide dismutases were also rich in glutathione peroxidase. 相似文献
6.
Bråthe A Andresen G Gundersen LL Malterud KE Rise F 《Bioorganic & medicinal chemistry》2002,10(5):1581-1586
Synthetic cytokinin analogues as well as the well known CKs 6-benzylaminopurine (BAP), kinetin and trans-zeatin were examined for antioxidant activity. The compounds were tested as potential diphenylpicrylhydrazyl (DPPH) scavengers and as inhibitors of 15-lipoxygenase (15-LO). The natural plant hormones were essentially inactive in both assays, but several synthetic analogues have a profound inhibiting effect on 15-lipoxygenase from soybeans. The same compounds were only weak DPPH scavengers and they may therefore be regarded as so-called non antioxidant inhibitors of 15-LO. 相似文献
7.
Kawai Y Watanabe M Matsuura M Nishijima M Kawahara K 《FEMS immunology and medical microbiology》2002,34(3):173-179
The partially degraded lipopolysaccharide of Burkholderia cepacia (LPSdegr) and the ornithine-containing lipids were purified from some bacteria. The substances were developed as complex lipid adjuvants, because they have weak toxicity and are able to activate the immune systems of the living body. After various toxoid antigens such as pertussis toxoid, diphtheria toxoid and tetanus toxoid were mixed with the complex lipid adjuvants, the mixtures were administered to mice subcutaneously. Antitoxoid IgG antibody titers in the serum were measured several times over 3 months. The efficacy of the LPSdegr as adjuvant was almost as high as that of the ornithine-containing lipids, and it was almost equal to that of the aluminum hydroxide adjuvant (Alum), which is generally used as a vaccine adjuvant. 相似文献
8.
Nikitina OV Shleev SV Gorshina ES Rusinova TV Serezhenkov VA Burbaev DSh Belovolova LV Yaropolov AI 《Biochemistry. Biokhimii?a》2005,70(11):1274-1279
A method for purification of enzymes from the ligninolityc complex of the basidiomycete Trametes pubescens (Schumach.) Pilat has been elaborated. Two homogeneous isoforms of laccases (laccase 1 and laccase 2) as well as a homogeneous preparation of lignin peroxidase were isolated. Basic biochemical parameters of the enzymes were determined, such as the molecular weights (67, 67, and 45 kD, respectively), isoelectric points (5.3, 5.1, and 4.2, respectively), as well as content and composition of the carbohydrate moiety of the laccases (N-acetylglucosamine, mannose, and xylose). The pH dependences and thermal stabilities of the laccases were investigated. The kinetic parameters of the enzymatic reactions catalyzed by the laccases were determined using different substrates, such as catechol, hydroquinone, 2,2 -azinobis-(3-ethylbenzthiazoline-6-sulfonate), and K4Fe(CN)6. The structure of the active sites of both laccases and the lignin peroxidase were studied by EPR, CD, and UV-VIS spectroscopy, as well as using fluorescence analysis. Our studies showed similarity of the spectral characteristics of the two laccases, whereas their kinetic properties were found to be different. 相似文献
9.
S H An-Foraker 《Acta cytologica》1985,29(3):286-290
In an evaluation of the efficacy of cerebrospinal fluid (CSF) examination in our laboratory, 1,635 CSF specimens received between March 1, 1975, and December 31, 1982, were reviewed. All 111 positive samples (from 77 cases) and all 141 suspicious samples (from 83 cases) were reviewed microscopically, and the clinical records in the cases were rechecked. The 77 positive cases were confirmed by tissue and other studies: 23 as primary brain tumors, 26 as secondary carcinomas, 14 as leukemias, 12 as lymphomas and 2 as multiple myelomas. The 83 suspicious cases were similarly confirmed: 31 as primary brain tumors, 14 as secondary carcinomas, 22 as leukemias and 7 as lymphomas-with 9 found to be "benign." There were no false positives in the positive group. This study suggests that the identification of malignant cells in CSF samples constitutes a reliable method of diagnosis and lessens the need for further biopsies. 相似文献
10.
P. V. Kumar A. Monabati A. R. Raseki C. Arshadi S. A. Malek-Hosseini A. R. Talei E. Sadeghi 《Cytopathology》2007,18(3):151-156
OBJECTIVE: To study fine needle aspiration (FNA) cytological findings of splenic lesions and assess the role of FNA in the diagnosis of splenomegaly or splenic tumours. METHODS: This study consisted of 48 cases, 25 males and 23 females. The ages ranged between 3 and 71 years. Most of these cases were aspirated under ultrasonographic guidance and a small number were also aspirated directly by using a 22- to 23-gauge needles. The smears were stained with Wright-Giemsa and Papanicolaou methods. Special stains were used whenever necessary. RESULTS: In this study 14 cases were diagnosed as lymphoma-leukaemia, 7 cases as tuberculosis, 12 cases as kala-azar, 2 cases as hydatid cyst, 3 cases as storage diseases, 3 cases as simple cyst, 2 cases as myeloproliferative disorders, 2 cases as malignant tumours and 3 cases as hamartomas (these were wrongly diagnosed as malignant tumours). CONCLUSION: Splenic aspiration is a safe procedure and is very useful in the diagnosis of parasitic and infectious diseases, especially in endemic countries like Iran. 相似文献
11.
The regional distribution and frequency of pancreatic endocrine cells in the red-bellied frog, Bombina orientalis, were studied by the immunohistochemical peroxidase anti-peroxidase (PAP) method using five types of specific mammalian antisera to insulin, glucagon, somatostatin, bovine pancreatic polypeptide (PP) and secretin. The frequency was calculated as the mean number of each endocrine cell type/1,000 total cells (including exocrine and endocrine cells) using an automated image analysis process. The percentage of each immunoreactive (IR) cell species to the total IR cell population was also calculated. In the pancreas of the red-bellied frog, all five endocrine cell types were demonstrated. Insulin IR cells were located in the pancreas as single cells or islet-like clusters. The latter were localized in central regions. The insulin-IR cells showed a frequency of 65.40 plus/minus 14.56/1,000 cells. Glucagon IR cells were also detected as single cells or as clusters but in the case of clusters, two distributional patterns were detected - a central core type and a marginally distributed type. They showed an abundance of 32.70 plus/minus 7.32/1,000 cells. Somatostatin-IR cells were dispersed throughout the pancreatic parenchyma as single cells, three to four cells, or clusters. The clusters were located in the marginal regions. The somatostatin-IR cell frequency was 19.40 plus/minus 6.52/1000 cells. PP-IR cells were randomly distributed throughout the pancreatic parenchyma as single cells with a frequency of 14.70 plus/minus 4.92/1,000 cells. Secretin-IR cells were demonstrated as clusters or as single cells, and as clusters they occupied the central regions. They showed a frequency of 39.60 plus/minus 10.36/1,000 cells. This is the first report of the presence of secretin-IR cells in amphibian pancreatic endocrine cells. Overall, there were 37.20 plus/minus 6.84% insulin-, 21.90 plus/minus 5.55% glucagon-, 11.60 plus/minus 4.33% somatostatin-, 8.60 plus/minus 2.72% PP- and 23.40 plus/minus 4.45% secretin-IR cells. 相似文献
12.
The soil yeast Trichosporon cutaneum was grown in continuous culture with phenol as the sole carbon source. The cultures were operated as carbon-limited chemostats or as steady-state continuous cultures without carbon limitation. Selected comparative runs were also conducted on glucose or acetate as carbon source. In addition to growth parameters, the activities of several intracellular enzymes were determined, comprising those directly involved in the degradation of phenol as well as auxiliary enzymes required for the generation of reducing power. All enzymes were assayed in detergent-permea-bilized cells. Phenol was found to serve as an excellent carbon source, comparable to glucose or acetate. The utilization of phenol in T. cutaneum is very efficient as indicated by a low maintenance requirement (0.01 g phenol/g cells.h). The cell yields obtained were on the order of 0.8 g cells/g phenol. Although the phenol-limited chemostats were run with fully phenol-induced cells, a further increase in the activities of isocitrate DH(NADP(+)), maleate DH and the phenol-degrading enzymes occurred after transition to nonlimiting condition. Enzyme activities increased in parallel with increasing phenol levels in the effluent, as well as with increasing toxicity. The significance of this phenomenon is discussed. The significance of this phenomenon is discussed. This elevation in enzyme activities in not related to an increase in specific growth rate. 相似文献
13.
以盘鮈属鱼类作为内群,以巴马拟缨鱼作为外群。通过形态比较共筛选出85个稳定的特征,形成形态特征状态矩阵表。以PAUP4.0b软件,采用均权方式,在无序和有序状态下分别按Heuristic、Branch-and-Bound以及Bootstrap等3种方式计算和构树。每种方法计算均得到唯一的1棵树,最大简约树与严格一致树、Bootstrap值检测树呈现微小差异。但仅最大简约树体现了各种之间先后分化的次序以及各姐妹群之间的关系,所以选择最大简约树作为盘鮈鱼类的系统发育树。其结果显示,盘鮈具小吸盘的种类与具大吸盘的种类分别构成了A、B两支。B支又可分为C、D两支。其中,C支的种类以吻端形成1对明显珠星,甚至形成吻突而区别于同属中具大吸盘的其他种类。运用Component(2.0)软件计算,得到盘鮈属种类分布河流的唯一分支树,其结构基本与水系的地理分布成对应关系。盘鮈属鱼类祖先的形成时期应为第4纪中期之初或更早。古云贵高原是盘鮈属鱼类的起源、分布和分化中心。云贵高原面的抬升与河流的袭夺促成了盘鮈属鱼类的多次分化和扩散,由此形成了该属鱼类的现今分布格局。 相似文献
14.
亚麻耐盐性愈伤组织的生理生化特性 总被引:4,自引:0,他引:4
以亚麻(双亚5号)耐盐愈伤组织为材,以同种亚麻普通愈伤组织为对照,分别经含0~250 mmol·L-1 NaC1的培养基培养20 d后,比较含水量、MDA含量、POD酶活、SOD酶活、EST同工酶谱、POD同工酶谱及SOD同工酶谱。结果表明:亚麻耐盐组愈伤组织与对照组愈伤组织在多方面存在明显差异,前者含水量均高于后者;丙二醛含量也高于后者,但变化幅度不大;POD酶活均高于对照组;酯酶同工酶谱不同于对照组,酯酶酶活量均高于对照组;POD同工酶谱比对照组多一条带,且酶活均高于对照组;SOD同工酶谱与对照组一样多,但酶活均高于对照组,且平稳。这为进一步筛选亚麻耐盐突变细胞系奠定了良好的基础。 相似文献
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16.
The mouse spot test. Evaluation of its performance in identifying chemical mutagens and carcinogens 总被引:1,自引:0,他引:1
The published results on 60 chemicals and X-rays investigated in the mouse spot test were compared with data on the same chemicals tested in the bacterial mutation assay (Ames test) and lifetime rodent bioassays. The performance of the spot test as an in vivo complementary assay to the in vitro bacterial mutagenesis test reveals that of 60 agents, 38 were positive in both systems, 6 were positive only in the spot test, 10 were positive only in the bacterial test and 6 were negative in both assays. The spot test was also considered as a predictor of carcinogenesis; 45 chemicals were carcinogenic of which 35 were detected as positive by the spot test and 3 out of 6 non-carcinogens were correctly identified as negative. If the results are regarded in sequence, i.e. that a positive result in a bacterial mutagenicity test reveals potential that may or may not be realized in vivo, then 48 chemicals were mutagenic in the bacterial mutation assay of which 38 were active in the spot test and 31 were confirmed as carcinogens in bioassays. 12 chemicals were non-mutagenic to bacteria of which 6 gave positive responses in the spot test and 5 were confirmed as carcinogens. These results provide strong evidence that the mouse coat spot test is an effective complementary test to the bacterial mutagenesis assay for the detection of genotoxic chemicals and as a confirmatory test for the identification of carcinogens. The main deficiency at present is the paucity of data from the testing of non-carcinogens. With further development and improvement of the test it is probable that the predictive performance of the assay in identifying carcinogens should improve, since many of the false negative responses may be due to inadequate testing. 相似文献
17.
根据超声波最佳提取工艺条件提取得到化橘红总黄酮,经乙酸乙酯萃取分为酯溶性和水溶性两部分,比较它们对亚硝化反应的抑制作用,并分别采用硅胶柱层析对酯溶性成分分离纯化,采用大孔吸附树脂法对水溶性成分进行分离纯化,得到4个主要的黄酮类化合物,研究它们对亚硝化反应的抑制作用,以期得到抑制亚硝化活性较强的化合物。结果表明化橘红总黄酮提取率可达26.42%,酯溶性和水溶性部分均能阻断亚硝胺的合成及清除亚硝酸盐,其中水溶性黄酮提取物作用较强,分离得到的4个黄酮类化合物中柚皮苷的抑制作用较强,对亚硝胺的合成的最大阻断率可达94.7%,对亚硝酸盐的最大清除率可达92.3%。 相似文献
18.
I Stoyanova A Dandov N Lazarov C Chouchkov 《Archives of physiology and biochemistry》1998,106(5):362-369
Several amino acids may function as neurotransmitters in the nervous system. The potential role of glutamate (Glu) and aspartate in excitatory responses was demonstrated and it was established that GABA and glycine act as inhibitory agents. The present study aimed at investigating the availability of Glu and GABA in certain feline sensory ganglia, i.e. the trigeminal (TrG), nodose and dorsal root ganglia (DRG). A significant part of the neurons were GABA-positive (19.5% to 23.5%). These were large-sized neurons as well as small- to medium-sized ones. The intensity of immunostaining varied from weak to strong. GABA-containing neuronal fibres were seen in the neuropil and some of them surrounded unstained ganglionic cells. The Glu-immunoreactive (IR) neuronal perikarya in all the investigated ganglia were 63.6% to 66.4%. The majority of positive cells were small- to medium-sized, but large primary sensory neurons were also seen. There was no difference between the intensity of the reaction in the primary sensory and small neurons. Glu-IR neuronal fibres were seen in close apposition to immunopositive as well as immunonegative neurons. In conclusion, in the TrG, nodose and DRG, GABA and glutamate are involved in neurotransmission. There is a significant number of GABAergic neurons in the investigated sensory ganglia of the cat. The difference in the expression of these amino acids suggests that they can act not only as neurotransmitters but also as modulators of sensory information. 相似文献
19.
Y Deshaies 《Canadian journal of physiology and pharmacology》1986,64(7):885-891
The present study was undertaken to compare plasma lipoprotein lipid composition, as well as white adipose tissue lipoprotein lipase activity, in rats fed purified diets high in either sucrose or corn oil. The experimental diets (65% of calories as sucrose or corn oil, 15% as the opposite nutrient, and 20% as casein) were given ad libitum for 4 weeks. An additional group was fed a nonpurified diet as a reference diet. Both sucrose and oil diets were spontaneously consumed in isocaloric amounts by the animals. Despite energy intakes that were 35% lower than that of the reference group, the sucrose and oil groups exhibited final body weights that were only 6 and 9% lower, respectively, than that of the reference group, and accumulated more fat in the epididymal depots. Postprandial as well as fasting total cholesterol levels were similar in the sucrose and oil groups, while the high-density lipoprotein to total cholesterol ratio was highest in the animals fed corn oil. In both the fasted and fed states, plasma total triglyceride levels were 73% higher in the sucrose group than in the corn oil group. The largest triglyceride differences due to diet were observed in the chylomicron + very-low-density lipoprotein fraction. The oil-fed rats accumulated large amounts of triglycerides in their livers. Postprandial lipoprotein lipase activity in epididymal adipose tissue was almost twice as high in the sucrose group as in the oil group.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
20.
We investigated the relation between visual and vocal attractiveness in women as judged by men. We recorded 34 women speaking four vowels and measured the peak frequency, the first five harmonic frequencies, the first five formant frequencies and formant dispersion. The women were also photographed (head shot), several body measures were taken and their ages were recorded. The voices were played to male judges who were asked to assess the women's age and vocal attractiveness from the recording. The men were then asked to assess the attractiveness of the photographs. Men were in strong agreement on which was an attractive voice and face; and women with attractive faces had attractive voices. Higher-frequency voices were assessed as being more attractive and as belonging to younger women (the lowest frequency produced is a good indicator of age in women in general). Larger women had lower voices and were judged as having less attractive faces and voices. Taller women had narrower formant dispersion as predicted. The results imply that different measures of attractiveness are in agreement and signal similar qualities, such as female age, body size and possibly hormonal profile. Copyright 2003 Published by Elsevier Science Ltd on behalf of The Association for the Study of Animal Behaviour. 相似文献