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231.
Deriving multipotent stem cells from mouse spermatogonial stem cells: a new tool for developmental and clinical research 总被引:3,自引:0,他引:3
In recent years, embryonic stem (ES) cell-like cells have been obtained from cultured mouse spermatogonial stem cells (SSCs). These advances have shown that SSCs can transition from being the stem cell-producing cells of spermatogenesis to being multipotent cells that can differentiate into derivatives of all three germ layers. As such, they offer new possibilities for studying the mechanisms that regulate stem cell differentiation. The extension of these findings to human SSCs offers a route to obtaining personalized ES-like or differentiated cells for use in regenerative medicine. Here, we compare the different approaches used to derive ES-like cells from SSCs and discuss their importance to clinical and developmental research. 相似文献
232.
Kuş C Ayhan-Kilcigil G Ozbey S Kaynak FB Kaya M Coban T Can-Eke B 《Bioorganic & medicinal chemistry》2008,16(8):4294-4303
Some novel 1-methyl-4-(2-(2-substitutedphenyl-1H-benzimidazol-1-yl)acetyl)thiosemicarbazides (16a-20a), 5-[(2-(substitutedphenyl)-1H-benzimidazol-1-yl)methyl]-N-methyl-1,3,4-thiadiazol-2-amines (17b-20b), and 5-[(2-(substitutedphenyl)-1H-benzimidazol-1-yl)methyl-4-methyl-2H-1,2,4-triazole-3(4H)-thiones (16c-20c) were synthesized and tested for antioxidant properties by using various in vitro systems. Compounds 16a-20a were found to be a good scavenger of DPPH radical (IC(50), 26 microM; IC(50), 30 microM; IC(50), 43 microM; IC(50), 55 microM; IC(50), 74 microM, respectively) when compared to BHT (IC(50), 54 microM). Noteworthy results could not be found on superoxide radical. Compound 19b, which is the most active derivative inhibited slightly lipid peroxidation (28%) at 10(-3)M concentration. Compound 17c inhibited the microsomal ethoxyresorufin O-deethylase (EROD) activity with an IC(50)=4.5 x 10(-4)M which is similarly better than the specific inhibitor caffeine IC(50)=5.2 x 10(-4)M. 相似文献
233.
Nitrogen and fungicide applications against Erysiphe cruciferarum affect quality components of oilseed rape 总被引:1,自引:0,他引:1
Oilseed rape (Brassica napus L.) is one of the most important oilseed crops in temperate climates. Erysiphe cruciferarum is an important disease of oilseed rape and causes crop loss in warmer areas of Europe. The research investigated the effect
of nitrogen fertilizer and fungicidal treatment against powdery mildew infection caused by E.
cruciferarum of oilseed rape on seed components, including protein, oil, oleic acid, linolenic acid and undesirable substances such as
sinapic acid esters (SAE) and glucosinolates (GSL), using near infrared spectroscopy (NIRS). Five susceptible oilseed rape
varieties were employed in this research using four treatment groups: no nitrogen fertilization and no fungicidal treatment
(N0–F0); no nitrogen fertilization but fungicidal treatment (N0–F1); and nitrogen fertilization but no fungicidal treatment (N1–F0); nitrogen fertilization and fungicidal treatment (N1–F1). Nitrogen fertilization increased the protein, but lowered the oil content, of the seeds. Fungicidal treatments significantly
increased oil contents in all varieties tested, however reduced protein levels in fertilized and non-fertilized plots. The
level of linolenic acid did not change significantly in any plots of any treatment combinations; a similar result was observed
in the level of oleic acid in most of the genotypes. Nitrogen fertilization increased GSL and SAE levels, whereas fungicidal
treatment had no effect. Our findings demonstrated that nitrogen fertilization can markedly influence some quality parameters
in oilseed rape; however, the application of fungicides reduced side effects of nitrogen fertilizer and resulted a reduction
on GSL, SAE and protein contents but an increase on total oil and oleic acid contents. 相似文献
234.
Mustafa Ceylan Umit M. Kocyigit Necibe Canan Usta Belma Gürbüzlü Yusuf Temel Saleh H. Alwasel İlhami Gülçin 《Journal of biochemical and molecular toxicology》2017,31(4):N/A-N/A
Benzothiazepine compounds have a wide range of applications such as antibacterial, antidepressants, anticonvulsants, antihypertensives, antibiotics, antifungal, hypnotic, enzyme inhibitors, antitumor, anticancer and anti‐HIV agents. In this study, the synthesis of novel tetralone‐based benzothiazepine derivatives ( 1–16 ) and their in vitro antibacterial activity and human carbonic anhydrase isoenzymes I and II (hCA I and II) inhibitory effects were investigated. Both isoenzymes were purified by sepharose‐4B‐l ‐tyrosine‐sulfanilamide affinity chromatography from fresh human red blood cells. All compounds demonstrated the low nanomolar inhibitory effects on both isoenzymes using esterase activity. Benzothiazepine derivative 2 demonstrated the best hCA I inhibitory effect with Ki value of 18.19 nM. Also, benzothiazepine derivative 7 showed the best hCA II inhibitory effect with Ki value of 11.31 nM. On the other hand, acetazolamide clinically used as CA inhibitor, showed Ki value of 19.92 nM against hCA I and 33.60 nM against hCA II, respectively. 相似文献
235.
Formulation of organic and inorganic hydrogel matrices for immobilization of β‐glucosidase in microfluidic platform
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Aslihan Kazan Marcel Heymuth Dilan Karabulut Seref Akay Ece Yildiz‐Ozturk Rabia Onbas Cahit Muderrisoglu Sayit Sargin Rene Heils Irina Smirnova Ozlem Yesil‐Celiktas 《Engineering in Life Science》2017,17(7):714-722
The aim of this study was to formulate silica and alginate hydrogels for immobilization of β‐glucosidase. For this purpose, enzyme kinetics in hydrogels were determined, activity of immobilized enzymes was compared with that of free enzyme, and structures of silica and alginate hydrogels were characterized in terms of surface area and pore size. The addition of polyethylene oxide improved the mechanical strength of the silica gels and 68% of the initial activity of the enzyme was preserved after immobilizing into tetraethyl orthosilicate–polyethylene oxide matrix where the relative activity in alginate beads was 87%. The immobilized β‐glucosidase was loaded into glass–silicon–glass microreactors and catalysis of 4‐nitrophenyl β‐d ‐glucopyranoside was carried out at various retention times (5, 10, and 15 min) to compare the performance of silica and alginate hydrogels as immobilization matrices. The results indicated that alginate hydrogels exhibited slightly better properties than silica, which can be utilized for biocatalysis in microfluidic platforms. 相似文献
236.
The results of experiments designed to show that inhibition of nitric oxide production in rats exposed to low lead levels increases vascular resistance, decreases renal blood flow and glomerular function, and enhances oxidative stress. Forty-five adult male Sprague-Dawley rats were divided into four groups. Group A was used as controls and consisted of rats that received no treatment; group B acted as NO-inhibited controls by receiving L-NAME (N(G)-nitro-l-arginine methyl ester) as the NO inhibitor; group C was injected intraperitoneally with 8 mg/kg lead acetate for 2 wk; and group D receiving lead acetate plus L-NAME. Compared to healthy controls, significant elevation of the mean (p<0.01), systolic (p<0.04), and diastolic (p<0.01) blood pressures was found in the lead-treated rats. The renal blood flow was 1550+/-468 blood per unit (bpu) in the controls, 488+/-220 bpu in the L-NAME controls, 1050+/-458 bpu in the lead-treated group, and 878+/-487 bpu in the Pb plus L-NAME group. Low-level lead exposure did not change the urinary flow rate, creatinine clearance, and the creatinine, potassium, phosphorus, glucose, and protein excretion in 24-h urine. In the lead plus NO-inhibited rats, a significant decrease in sodium ion excretion was observed (p<0.01). The NO levels of the lead exposed, L-NAME-treated controls, and L-NAME plus lead-exposed groups are significantly lower compared to untreated controls: p<0.002, p<0.001, and p<0.01, respectively. When compared to untreated controls, the plasma malondialdehyde levels were not significantly different in the lead exposed, lead plus L-NAME, and L-NAME control groups. These results suggest that lead-induced hypertension might be related to a decrease of NO and consequent vasoconstriction, rather than to a decrease of renal blood flow or to decreases in renal sodium. 相似文献
237.
Yayli N Yaşar A Güleç C Usta A Kolayli S Coşkunçelebi K Karaoğlu S 《Phytochemistry》2005,66(14):1741-1745
The essential oils of air-dried Centaurea sessilis and Centaurea armena obtained by hydrodistillation were analyzed by gas chromatography-mass spectrometry (GC-MS). Forty and twenty components were identified in the essential oils and the main component of these taxons was beta-eudesmol in the ratios of 12.4% and 19.3% from C. sessilis and C. armena, respectively. The antimicrobial activity of the isolated essential oil of the plants was also investigated. They showed moderate antibacterial activity against Gram-positive and Gram-negative bacteria, but no antifungal activity was observed against two yeastlike fungi. 相似文献
238.
Hemangioendotheliomas can express type 3 iodothyronine deiodinase and cause severe hypothyroidism. The risk of congenital malformations such as vertebral and cardiac abnormalities in infants of diabetic mothers is higher than in babies of healthy women. Here we report an infant of a diabetic mother with hypothyroidism caused by liver hemangioendothelioma. Consumptive hypothyroidism should be an indicator to search for a vascular tumor in infants. Supranormal doses of L-thyroxine might be required for normalization of thyroid function until the tumor involutes or is resected. 相似文献
239.
240.
Galactan: galactan galactosyltransferase (GGT), an enzyme involved in the biosynthesis of the long-chain raffinose family of oligosaccharides (RFOs) in Ajuga reptans, catalyses the transfer of an alpha-galactosyl residue from one molecule of RFO to another one resulting in the next higher RFO oligomer. This novel galactinol (alpha-galactosyl-myo-inositol)-independent alpha-galactosyltransferase is responsible for the accumulation of long-chain RFOs in vivo. Warm treatment (20 degrees C) of excised leaves resulted in a 34-fold increase of RFO concentration and a 200-fold increase of GGT activity after 28 days. Cold treatment (10 degrees C/3 degrees C day/night) resulted in a 26- and 130-fold increase, respectively. These data support the role of GGT as a key enzyme in the synthesis and accumulation of long-chain RFOs. GGT was purified from leaves in a 4-step procedure which involved fractionated precipitation with ammonium sulphate as well as lectin affinity, anion exchange, and size-exclusion chromatography and resulted in a 200-fold purification. Purified GGT had an isoelectric point of 4.7, a pH optimum around 5, and its transferase reaction displayed saturable concentration dependence for both raffinose (Km = 42 mM) and stachyose (Km = 58 mM). GGT is a glycoprotein with a 10% glycan portion. The native molecular mass was 212 kDa as determined by size-exclusion chromatography. Purified GGT showed one single active band after native PAGE or IEF separation, respectively, which separated into three bands on SDS-PAGE at 48 kDa, 66 kDa, and 60 kDa. The amino acid sequence of four tryptic peptides obtained from the major 48-kDa band showed a high homology to plant alpha-galactosidase (EC 3.2.1.22) sequences. GGT differed, however, in its substrate specificity from alpha-galactosidases; it neither hydrolysed nor transferred alpha-galactosyl-groups from melibiose, galactinol, UDP-galactose, manninotriose, and manninotetrose. Galactinol, sucrose, and galactose inhibited the GGT reaction considerably at 10-50 mM. 相似文献