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101.
102.
One newly bred variety of tea cultivar, purple-shoot tea, was selected to evaluate its antiproliferative effects on colorectal carcinoma cells, as well as normal colon cells. The phytochemicals and identified catechins of purple-shoot tea extract (PTE) were significantly higher than that of ordinary tea, especially the anthocyanins (surpassed by 135-fold) and anthocyanidins (surpassed by 3.5-fold). PTE inhibited the proliferation of COLO 320DM (IC(50) = 64.9 μg/mL) and HT-29 (IC(50) = 55.2 μg/mL) by blocking cell cycle progression during the G(0)/G(1) phase and inducing apoptotic death. Western blotting indicated that PTE induced cell cycle arrest by reducing the expression of cyclin E and cyclin D1 in COLO 320DM and the upregulation of p21 and p27 cyclin-dependent kinase inhibitors in HT-29. Two cells treated with PTE also indicated the cleavage of PARP, activation of caspase 3, and an increased Bax/Bcl-2 ratio. Our results showed that PTE is a potential novel dietary agent for colorectal cancer chemoprevention.  相似文献   
103.
ObjectiveTo determine changes in cardiac troponin I concentration (cTnI) associated with cardiovascular catheterization in dogs.Animals, materials and methodscTnI was measured after transarterial coil embolization of patent ductus arteriosus (PDA), balloon valvuloplasty (BV), and pacemaker implantation (PACE). Dogs undergoing ovariohysterectomy (OHE) were used as a control, with 15 animals in each group. Blood for the cTnI assay was collected at baseline (T0), at 5 h (T5), 24 h (T24) and 10 days (T240) post-procedure. The effects of age, duration and difficulty of the procedure were evaluated.ResultsThere was no difference in cTnI concentration at T0 for any of the groups. There was a significant increase in cTnI concentration for BV and PACE, but not PDA at T5 and T24. PACE at T24 and T240 also had higher cTnI than control. Dogs with longer procedure times had significantly higher concentration of cTnI. There was no correlation between the difficulty of the procedure or peri-procedure complications and cTnI.ConclusioncTnI increased during some cardiovascular catheterization procedures, but returned to normal values at 24–240 h. Patients undergoing long catheterization procedures have increased risk for myocardial injury, but this was not related to short-term prognosis.  相似文献   
104.
1. This study was to investigate the development of the activities of pancreatic and caecal enzymes in White Roman goslings from hatching to 28 d of age. 2. A total of 80 1-d-old goslings were used. At hatching, 3 and 7 d of age, 16 goslings (8 males and 8 females) were used. At 11, 14, 21 and 28 d of age, 8 goslings, 4 males and 4 females were selected. The activities of amylase, lipase, trypsin and chymotrypsin in each segment of the small intestine (duodenum, jejunum, ileum) and their contents and the activity of cellulase in the caecal contents were measured. 3. The specific activity (SA) of amylase in the duodenal mucosa and contents increased significantly both from 11 to 14 and 14 to 21 d of age and declined after 28 d of age. In the jejunum and ileum, there was a significant peak in the SA of amylase in the mucosa in goslings from 7 to 21 d of age. On average, the SA of lipase of mucosa and content in the small intestine was initially low but gradually increased from 14 to 21 and from 21 to 28 d of age. 4. The SA of trypsin in the contents of the duodenum and the jejunum increased both from 7 to 11 and 11 to 14 d of age and there was high activity in the ileal contents from 14 to 21 d of age. From 3 to 14 d of age, the SA of chymotrypsin in the duodenal mucosa significantly increased and peaked. There was a significant peak at 11 d of age in the SA of chymotrypsin in the duodenal or jejunal contents and in the ileal contents at 7 d. The SA of cellulase in the caecal contents increased linearly with age, reaching a plateau at 28 d of age. 5. The rate of activity development varied from hatching to 28 d of age. However, the mean SA of amylase and lipase of intestinal contents reached a peak at 21 d, trypsin and chymotrypsin at 11 d and cellulase at 28 d of age, respectively. The quantitative changes in SA of cellulase, amylase, lipase, trypsin and chymotrypsin increased by about 4-, 3-, 5-, 2- and 3-fold, respectively, in the intestinal content of goslings. Thus, development of proteases in the intestine of goslings peaked more rapidly than amylase, lipase and cellulase during the first 4 weeks.  相似文献   
105.
The maltooligosyltrehalose trehalohydrolase (MTHase) mainly cleaves the alpha-1,4-glucosidic linkage next to the alpha-1,1-linked terminal disaccharide of maltooligosyltrehalose to produce trehalose and the maltooligosaccharide with lower molecular mass. In this study, the treZ gene encoding MTHase was PCR-cloned from Sulfolobus solfataricus ATCC 35092 and then expressed in Escherichia coli. A high yield of the active wild-type MTHase, 13300 units/g of wet cells, was obtained in the absence of IPTG induction. Wild-type MTHase was purified sequentially using heat treatment, nucleic acid precipitation, and ion-exchange chromatography. The purified wild-type MTHase showed an apparent optimal pH of 5 and an optimal temperature at 85 degrees C. The enzyme was stable at pH values ranging from 3.5 to 11, and the activity was fully retained after a 2-h incubation at 45-85 degrees C. The k(cat) values of the enzyme for hydrolysis of maltooligosyltrehaloses with degree of polymerization (DP) 4-7 were 193, 1030, 1190, and 1230 s(-1), respectively, whereas the k(cat) values for glucose formation during hydrolysis of DP 4-7 maltooligosaccharides were 5.49, 17.7, 18.2, and 6.01 s(-1), respectively. The K(M) values of the enzyme for hydrolysis of DP 4-7 maltooligosyltrehaloses and those for maltooligosaccharides are similar at the same corresponding DPs. These results suggest that this MTHase could be used to produce trehalose at high temperatures.  相似文献   
106.
3-Deoxyanthocyanidins are structurally related to the anthocyanin pigments, which are popular as health-promoting phytochemicals. Here, it is demonstrated that the 3-deoxyanthocyanidins are more cytotoxic on human cancer cells than the 3-hydroxylated anthocyanidin analogues. At 200 microM concentration, luteolinidin reduced the viability of HL-60 and HepG2 cells by 90 and 50%, respectively. Sorghum is a major source of 3-deoxyanthocyanidins, which are present as seed pigments and as phytoalexins responding to pathogen attack. On the basis of the collision-induced dissociation spectra of luteolinidin and apigeninidin, an LC-MS/MS method, operating in multiple-reaction monitoring mode, was developed for the specific detection and accurate quantification of these compounds in complex mixtures, which may be difficult to analyze using absorbance measurements. The results demonstrated that inoculated sorghum seedlings could be utilized for convenient and large-scale production of 3-deoxyanthocyanidins. A quantity of almost 270 microg/g (fresh weight) of luteolinidin was produced 72 h after fungal inoculation of 1-week-old seedlings.  相似文献   
107.
108.
In the case of recently established populations of Solenopsis invicta in Taiwan, analysis of genetic variation may provide various dimensions regarding the historical demographic events of this invasive species, which represents a novel opportunity to study the genetic consequences of invasiveness over an extremely short time period. Here we describe genetic structure of two introduced S. invicta populations,Taoyuan and Chiayi, in Taiwan using two classes of markers, nuclear (microsatellites) and mitochondrial (mtDNA) genomes. Pronounced regional differentiation inferred from either AMOVA or Bayesian clustering approach at both genomes suggests that the two populations most likely originate from separate introductions.Furthermore, significant mtDNA but not nuclear differentiation between sympatric social forms suggests two scenarios that interform gene flow is mainly mediated by males, and queens of each form commonly fail to become egg-layers of alternate form. Isolation by distance (IBD) obtained from microsatellites is absent in monogynes, indicating sexuals of this form retain the superior dispersal ability to homogenize the nuclear signature among spatially isolated areas; however, lack of IBD in less vagile polygyne may result from frequent human mediated jump dispersal that erodes the geographical restrictions of genetic exchange. The patterns observed here not only provide insights into how social organization influences the interform gene flow but also reinforce different breeding strategies pursued by two forms in the character of shaping the genetic variation at two levels of genomes.  相似文献   
109.
Forest ecosystems in Taiwan are periodically influenced by typhoons that cause large amounts of litter input to the soil. The potential rapid decomposition of such litter under the warm and moist climatic conditions in Taiwan may lead to nutrient losses via seepage. The goal of this study was to investigate the dynamics of C, N, K, Ca, Mg, and dissolved organic carbon (DOC) during decomposition of Chamaecyparis obtusa var. formosana leaves in a field study at the Yuanyang Lake site in N Taiwan. We simulated the effect of a typhoon by adding about three times the annual aboveground litterfall (totally 13,900 kg ha–1) as fresh leaves. Litterbags were taken at 7 dates over 16 months, followed by detection of mass loss and element composition in the remaining litter. Aqueous extracts of the remaining litter were analyzed for DOC and major elements. The properties of DOC were characterized by fluorescence spectra and by its stability against microbial decomposition. The litter mass loss was 35% after 16 months. The losses of Ca after 16 months from the litter bags were about equivalent to mass loss (39%), while those of K and Mg reached 86% and 60% of the initial amount, respectively. From the 13,900 kg ha–1 of litter applied in total, 59 kg K ha–1 and 12 kg Mg ha–1 were released in the 16 months decomposition period, most of it in the first 4 months. The total release of Ca amounted to 69 kg ha–1 but was more evenly distributed throughout the 16 months of observation. The absolute amount of N in the decomposing litter increased by 37% while the C : N decreased from 69 to 34. Extrapolated to the manipulation treatment, this resulted in a N gain of 36 kg N ha–1 within 16 months. The leaching of K and DOC in laboratory extractions followed an asymptotic function with highest leaching from the initial litter and subsequent decrease with time of decomposition. On the contrary, the leaching of Ca and Mg reached a maximum after 2–4 months of incubation. About 2% of the C was extractable with water from the initially incubated leaves. The bioavailability of the extracted DOC decreased with litter age. Our results indicate that the decomposition of large amounts of litter induces a high risk of K and Mg losses with seepage, but the risk for N losses is low. The sources of N accumulation in decomposing litter at this site require further studies. In the initial phase of litter decomposition, the release of DOC seems to be an important contribution to mass loss.  相似文献   
110.
A recombinant Bacillus subtilis producing soy cystatin was developed by subcloning with a soy cystatin gene cloned in Escherichia coli. An active form of cystatin against the cysteine protease from Pacific whiting fillets contaminated with Myxosporidia parasite was constitutively expressed and secreted extracelluarly into the medium. Two gene fragments of signal peptides from kerA and sacB were introduced and compared for secretion efficiency of cystatin. The secretion level of active cystatin improved with the signal peptide of kerA when compared to that of sacB. Inhibitor activity was reduced rapidly after peak expression of the target protein at 36 h of fermentation. The addition of 1% glucose, a suppressor of protease, into the medium sustained the increase of the cystatin activity during fermentation. This study introduced a potential new method for fermentation production of cystatin.  相似文献   
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