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841.
Five strains of anaerobic fungi isolated from the faeces of wild (hog deer, Cervus porcinus; blackbuck, Antelope cervicapra; spotted deer, Axis axis; nilgai, Baselophus tragocamelus) and rumen liquor of domestic (sheep, Ovies aries) ruminants showing high fibrolytic enzyme producing ability were added to mixed rumen microflora of buffalo to study their effect on the digestibility of lignocellulosic feed (wheat straw and wheat bran in the ratio of 80:20), enzyme production and fermentation end products in in vitro conditions. Among the 5 isolates studied, FNG5 (isolated from nilgai) showed the highest stimulating effect on apparent digestibility (35.31 +/- 1.61% vs. 28.61 +/- 1.55%; P < 0.05), true digestibility (43.64 +/- 1.73% vs. 35.37 +/- 1.65%; P < 0.01), neutral detergent fiber digestibility (29.30 +/- 2.58% vs. 18.47 +/- 2.12; P < 0.01) of feed 24 h after inoculation compared to the control group. The production of carboxymethyl cellulase, xylanase, acetyl esterase and beta-glucosidase was significantly (P < 0.05) higher in the FNG5 inoculated incubation medium. There was no improvement in the digestibility and enzyme production on the addition of the other 4 isolates. Total volatile fatty acid levels as well as the concentration of acetate, propionate, isobutyrate and valerate were significantly higher in the FNG5 added group as compared to the control group. The fungal isolate FNG5 from nilgai, a wild ruminant, was found to be superior to the other isolates tested and appears to have a potential to be used as a feed additive for improving fiber degradation in domestic ruminants.  相似文献   
842.
Betulinic acid and its derivatives as anti-angiogenic agents   总被引:2,自引:0,他引:2  
Betulinic acid (1) significantly caused cytotoxicity to endothelial cell line ECV304 (IC(50) 1.26+/-0.44 microg/mL) in a 5-day MTT assay. Novel and more potent derivatives of betulinic acid (2, 4, 6-8) have been synthesized with IC(50) less than 0.4 microg/mL. The endothelial cell specificity against human tumor cell lines DU145, L132, A549, and PA-1 were determined. Further betulinic acid (1) inhibited TLS formation of ECV304 cells on Matrigel(TM) by 5.5% while its derivatives caused an inhibition of 13.1-49.2%.  相似文献   
843.
Aluminum (Al)-tolerant cell lines (ALT301 and ALT401) of tobacco were isolated in a simple calcium (Ca) solution from ethyl methane sulfonate (EMS)-treated suspension cultured tobacco cells ( Nicotiana tabacum L. cv. Samsun, a cell line SL) at the logarithmic phase of growth. A highly tolerant cell line ALT301 exhibited the accumulation of Al and the deposition of callose to the same extent as the parental SL cells during the exposure to Al. However, the Al-treated ALT301 cells grew much better than the Al-treated SL cells after transfer to Al-free growth medium. Compared to SL cells, ALT301 cells were more tolerant to toxicity of copper and iron, but not to that of lanthanum. These results suggest that ALT301 cells have an internal tolerance mechanism, which makes cells grow normally in spite of Al accumulation and Al-induced lesion represented by the deposition of callose. This tolerance mechanism seems also to be effective against copper and iron toxicity. A slightly tolerant cell line ALT401 also accumulated Al to the same degree as SL cells, but deposited significantly less callose than did SL cells (43% of SL). The growth of ALT401 cells after Al treatment was only slightly better than that of SL cells. Thus, it seems that ALT401 cells have a mechanism to protect cells only from the Al-induced deposition of callose, which is not enough to overcome the Al-induced inhibition of growth. The different phenotypes exhibited by these Al-tolerant cell lines suggest that the deposition of callose is not directly related to the inhibition of growth in Al-treated cells.  相似文献   
844.
The DNA-protein cross-links (DPC) in mouse thymocytes and spleen lymphocytes, the number of abnormal sperm heads (ASH) and the number of micronuclei (MN) in normochromatic erythrocytes (NCE) of peripheral blood were studied in mice exposed to long-term low-intensity gamma radiation (0.072 cGy/days) and/or cadmium with drinking water (0.01 mg Cd2+/l) for 20, 40 and 80 days. The dependence of DPC level on the total dose (exposure time) of gamma radiation and/or cadmium is nonlinear. The maximal level of DPC in cells of lymphoid organs upon exposure to gamma radiation or cadmium was recorded on the 40-th day, and under combined exposure on the 20-th day of the experiment. The long-term exposure to cadmium or gamma radiation causes an increase in the ASH frequency. The increase in frequencies of MN in NCE and reciprocal translocations in spermatocytes was not found.  相似文献   
845.
Six octapeptide bombesin (BN) analogs were synthesized by substituting alpha-aminoisobutyric acid (Aib), in place of Ala9 or Gly11, or both, in the [D-Phe6, desMet14]-BN (6-14) sequence: D-Phe6-Gln7-Trp8-Ala9-Val10-Gly11-His12-Leu13-NH2 (P0). Additionally, Leu13 was replaced with isoleucine in two analogs and one of the analogs was butanoylated at the N-terminus. The antiproliferative activity of the analogs was tested in vitro on human pancreatic (MiaPaCa-2) and colon cancer (SW620, HT29 and PTC) cell lines using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The analogs demonstrated anticancer activity in the above cell lines at concentrations ranging from 0.01 nM to 1 microM. One of the analogs, P6, was evaluated for in vivo tumor regression in a xenograft model of human primary colon cancer in athymic nude mice and was found to cause significant reduction in tumor volume. NMR and molecular dynamics (MD) simulation studies for this analog revealed the presence of a mixed 3(10)/alpha-helical structure. This study demonstrates that the designed BN analogs retain their anticancer activity after the incorporation of the constrained amino acid, Aib, and are potential molecules for future use in cancer therapy and drug targeting.  相似文献   
846.
Six polymorphic microsatellite DNA loci were identified in the primitive fish, bronze featherback, Notopterus notopterus for the first time and demonstrated significant population genetic structure. Out of the six primers, one primer (NN90) was specific to N. notopterus (microsatellite sequence within the RAG1 gene) and five primers were product of successful cross-species amplification. Sixty-four primers available from 3 fish species of order Osteoglossiformes and families Notopteridae and Osteoglossidae were tested to amplify homologous microsatellite loci in N. notopterus. Fifteen primer pairs exhibited successful cross-priming PCR product. However, polymorphism was detected only at five loci. To assess the significance of these six loci (including NN90) in population genetic study, 215 samples of N. notopterus from five rivers, viz Satluj, Gomti, Yamuna, Brahmaputra and Mahanadi were analyzed. The five sample sets displayed different diversity levels and observed heterozygosity ranged from 0.6036 to 0.7373. Significant genotype heterogeneity (P < 0.0001) and high FST (0.2205) over all loci indicated that the samples are not drawn from the same genepool. The identified microsatellite loci are promising for use in fine-scale population structure analysis of N. notopterus.  相似文献   
847.
Corynebacterium striatum is a potentially pathogenic microorganism with the ability to produce outbreaks of nosocomial infections. Here, we document a nosocomial outbreak caused by multidrug-resistant (MDR) C. striatum in Rio de Janeiro, Brazil. C. striatum identification was confirmed by 16S rRNA and rpoB gene sequencing. Fifteen C. striatum strains were isolated from adults (half of whom were 50 years of age and older). C. striatum was mostly isolated in pure culture from tracheal aspirates of patients undergoing endotracheal intubation procedures. The analysis by pulsed-field gel electrophoresis (PFGE) indicated the presence of four PFGE profiles, including two related clones of MDR strains (PFGE I and II). The data demonstrated the predominance of PFGE type I, comprising 11 MDR isolates that were mostly isolated from intensive care units and surgical wards. A potential causal link between death and MDR C. striatum (PFGE types I and II) infection was observed in five cases.  相似文献   
848.

Background and Aims

The large monophyletic genus Mimosa comprises approx. 500 species, most of which are native to the New World, with Central Brazil being the main centre of radiation. All Brazilian Mimosa spp. so far examined are nodulated by rhizobia in the betaproteobacterial genus Burkholderia. Approximately 10 Mya, transoceanic dispersal resulted in the Indian subcontinent hosting up to six endemic Mimosa spp. The nodulation ability and rhizobial symbionts of two of these, M. hamata and M. himalayana, both from north-west India, are here examined, and compared with those of M. pudica, an invasive species.

Methods

Nodules were collected from several locations, and examined by light and electron microscopy. Rhizobia isolated from them were characterized in terms of their abilities to nodulate the three Mimosa hosts. The molecular phylogenetic relationships of the rhizobia were determined by analysis of 16S rRNA, nifH and nodA gene sequences.

Key Results

Both native Indian Mimosa spp. nodulated effectively in their respective rhizosphere soils. Based on 16S rRNA, nifH and nodA sequences, their symbionts were identified as belonging to the alphaproteobacterial genus Ensifer, and were closest to the ‘Old World’ Ensifer saheli, E. kostiensis and E. arboris. In contrast, the invasive M. pudica was predominantly nodulated by Betaproteobacteria in the genera Cupriavidus and Burkholderia. All rhizobial strains tested effectively nodulated their original hosts, but the symbionts of the native species could not nodulate M. pudica.

Conclusions

The native Mimosa spp. in India are not nodulated by the Burkholderia symbionts of their South American relatives, but by a unique group of alpha-rhizobial microsymbionts that are closely related to the ‘local’ Old World Ensifer symbionts of other mimosoid legumes in north-west India. They appear not to share symbionts with the invasive M. pudica, symbionts of which are mostly beta-rhizobial.  相似文献   
849.
The predatory mite, N. longispinosus preys up on red spider mite, O. coffeae infesting tea in south India. An attempt has been made to determine the predatory potential, prey stage preference and optimum predator–prey ratio of N. longispinosus under laboratory and green house conditions. When 50 adult female O. coffeae were given, the number of adults reduced by eight days along with an increase in the number of predators. The larvae hatched from the eggs laid by O. coffeae were fed by predatory mite. N. longispinosus preyed up on all life stages with a preference to larvae and nymphs of red spider mite. Predator–prey ratios of 1:33 and 1:50 were effective in lab, and 1:25 was found to be effective in green house. These results revealed that N. longispinosus could be used as a successful biocontrol candidate of O. coffeae in tea through augmentation or mass rearing and field release.  相似文献   
850.
DNA fragmentation factor 40 (DFF40) is an endonuclease that acts downstream in the apoptotic cascade. The objective of this study was to generate a novel humanized chimeric protein with human DFF40 fused with GM-CSF for targeting acute myeloid leukemia (AML) cells. cDNA cloning of human DFF40 and GM-CSF was done and the chimeric gene GM-CSF-DFF40 was generated by overlap extension PCR. The fusion protein was expressed in E.coli, purified, refolded and characterized. In vitro cytotoxicity was evaluated on various AML cell lines. Treated cell lines were screened for various morphological and biochemical changes that are characteristic of apoptosis, by different assays like annexin V-FITC staining, TUNEL assay, JC-1 staining and immunocytochemistry of pro-apoptotic proteins and caspases. Cell cycle analysis of treated cells was done to quantify the percentage of apoptotic cells. The chimeric protein was found to be cytotoxic to AML cells in a dose and time dependent manner. Morphological changes such as formation of apoptotic bodies were revealed by microscopic examination of treated cells after staining. Immunocytochemical staining demonstrated biochemical changes such as changes in mitochondrial membrane potential, mitochondrial co-localization of Bax, cytochrome c release, presence of activated caspase-3 and DNA fragmentation. FACS analysis proved the presence of apoptotic cells following treatment. The chimeric protein GM-CSF-DFF40 was found to mediate targeted killing of AML cells by inducing apoptosis. Thus, this chimeric construct can act as a prospective candidate for targeted therapy of AML and other malignancies where GM-CSF receptor expression is upregulated.  相似文献   
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