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81.
Forty-seven samples of corn were collected from various street bazaars and market outlets in different regions of Turkey and
total aflatoxin (AF) and ochratoxin A (OTA) levels were determined by enzyme-linked immunosorbent assay (ELISA) following
sample preparation. Levels of AF and OTA in corn samples ranged between 1.75–120.3 μg/kg and 1.08–8.57 μg/kg, respectively.
Although 53% of the samples analysed had no detectable levels of AF, 4% of similar samples were found to contain AFs above
the acceptable limit of 10 μg/kg in Turkey. For OTA, 4% of the corn samples had levels above the acceptable limit (3 μg/kg)
in Turkey, with over 43% samples not found to contain this mycotoxin. Although the levels of mycotoxins analysed in this study
were not found to be high and the percentage of samples contaminated above permitted limits were low, the importance of overall
daily dietary intake should not be underestimated and control of these fungal metabolites in corn must be explored to minimise
the hazards they may cause in humans. 相似文献
82.
In this study, the capacity of 30 strains of lactobacilli to coaggregate withCandida albicans ATCC 10239,C. albicans AJD 180 andCandida krusei ATCC 6258 were studiedin vitro. A marked coaggregation withC. albicans was observed for two strains ofLactobacillus crispatus, a strain ofLactobacillus cellobiosus and a strain ofLactobacillus salivarius. Coaggregation occurred at a pH range from 3 to 7, some strains showing optimal binding at high and other strains at low pH. Treatment of lactobacilli at 70 or 85°C for 20 min or treatment of the bacteria with pepsin abolished their capacity of coaggregation. The results may be of importance when trying to establish probiotics for vaginal use. 相似文献
83.
Functional requirements for signaling through the stimulatory and inhibitory mouse NKR-P1 (CD161) NK cell receptors 总被引:2,自引:0,他引:2
Ljutic B Carlyle JR Filipp D Nakagawa R Julius M Zúñiga-Pflücker JC 《Journal of immunology (Baltimore, Md. : 1950)》2005,174(8):4789-4796
The NK cell receptor protein 1 (NKR-P1) (CD161) molecules represent a family of type II transmembrane C-type lectin-like receptors expressed predominantly by NK cells. Despite sharing a common NK1.1 epitope, the mouse NKR-P1B and NKR-P1C receptors possess opposing functions in NK cell signaling. Engagement of NKR-P1C stimulates cytotoxicity of target cells, Ca2+ flux, phosphatidylinositol turnover, kinase activity, and cytokine production. In contrast, NKR-P1B engagement inhibits NK cell cytotoxicity. Nonetheless, it remains unclear how different signaling outcomes are mediated at the molecular level. Here, we demonstrate that both NKR-P1B and NKR-P1C associate with the tyrosine kinase, p56(lck). The interaction is mediated through the di-cysteine CxCP motif in the cytoplasmic domains of NKR-P1B/C. Disrupting this motif leads to abrogation of both stimulatory and inhibitory NKR-P1 signals. In addition, mutation of the consensus ITIM (LxYxxL) in NKR-P1B abolishes both its Src homology 2-containing protein tyrosine phosphatase-1 recruitment and inhibitory function. Strikingly, engagement of NKR-P1C on NK cells obtained from Lck-deficient mice failed to induce NK cytotoxicity. These results reveal a role for Lck in the initiation of NKR-P1 signals, and demonstrate a requirement for the ITIM in NKR-P1-mediated inhibition. 相似文献
84.
Belma?Aslim Zehra?Nur?Yüksekdag?Email author Yavuz?Beyatli Nazime?Mercan 《World journal of microbiology & biotechnology》2005,21(5):673-677
Summary The optimal temperature, pH and incubation time for production of exopolysaccharide (EPS) by Lactobacillus delbruckii subsp. bulgaricus and Streptococcus thermophilus strains in MRS and M17 media, respectively, were determined. In all strains, the temperature and incubation time for EPS production were 45 °C and 18 h, respectively. At 45 °C, L. delbruckiisubsp. bulgaricus B3 and G12 and S. thermophilus W22 strains produced 263, 238 and 127 mg/l, respectively. At 18 h, B3, G12 and W22 strains produced 220, 152 and 120 mg/l, respectively. While the pH for highest EPS production by L. delbruckii subsp. bulgaricus strains was 6.2 (in B3 strain: 211 mg/l, in G12 strain: 175 mg/l), for highest EPS production byS. thermophilus
strain it was 6.8 (114 mg/l). 相似文献
85.
We investigated the effect of treatment with an angiotensin II receptor blocker, candesartan-cilexetil, on the mechanical and electrophysiological properties of cardiomyocytes isolated from streptozotocin-induced diabetic (STZ) rats. Contractile activity and electrophysiological properties were measured in papillary muscle and ventricular cardiomyocytes from normoglycemic and STZ-induced diabetic rats given vehicle or 5mg/kg/day candesartan-cilexetil for 4 weeks. Alterations in the kinetics of contractile activity and intracellular Ca(2+) transients were observed as well as a typical prolongation of action potential duration and significant decrease of potassium currents in diabetic rat heart preparations. Candesartan-cilexetil treatment recovered significantly prolonged action potential and depressed potassium currents in diabetic rats. It was also shown that treatment with AT(1) blocker restored altered kinetics of both the Ca(2+) transients in cardiomyocytes and the contractile activity in papillary muscle strips of diabetic rats. We also showed that incubation of cardiomyocytes from diabetic rats with a protein kinase C (PKC) inhibitor bisindolylmaleimide I (BIM) had a similar effect to candesartan treatment on the Ca(2+) transients. Thus, angiotensin II receptor blockade protects the heart from the development of cellular alterations typically related with diabetes, and this action of AT(1) receptors seems to be related with the activity of PKC. 相似文献
86.
Emine Demirel-Yilmaz Deniz Dinçer Gürsel Yilmaz Belma Turam 《Biological trace element research》1998,64(1-3):161-168
The effects of dietary sodium selenite and vitamin E on the microvascular permeability of rat organs such as heart, brain,
kidney, liver and eye were investigated by using the Evans blue leakage method. Combined deficiency of selenium and vitamin
E caused an increase in the permeability of the heart and eye with respect to their controls while it had no considerable
effect on the permeability of other organs. On the other hand, toxic levels of selenium (4.2 mg/kg) in diet decreased the
permeabilities in kidney, liver, and eye whereas this parameter of brain increased in the same animal group. These results
suggested that low or high sodium selenite and vitamin E contents in diet could alter the microvascular permeability of different
organs in different manners. It might be important to give reasonable explanations for the pathophysiology of some diseases
that are characterized with organ damage and /or disfunction originated from selenium deficiency or toxicity. 相似文献
87.
Belma Z. Kurt Fatih Sonmez Basak Gokce Adem Ergun Nahit Gencer Taki Demir Oktay Arslan Mustafa Kucukislamoglu 《Russian Journal of Bioorganic Chemistry》2016,42(5):506-511
Coumarin and heterocyclic compounds incorporating urea have clinical applications as antiepileptics, diuretics, and antiglaucoma agents due to their carbonic anhydrase inhibitory properties. We investigated inhibition of carbonic anhydrase I and II with a series of coumarylthiazole derivatives containing urea/thiourea groups. All the investigated compounds exhibited inhibitory activity on both hCA I and hCA II, with 1-(3-chlorophenyl)-3-(4-(2-oxo-2H-chromen-3-yl)thiazol-2-yl)urea being the strongest inhibitor. Structure–activity relationship study showed that most of urea derivatives were more inhibiting for hCA I and hCA II than thiourea derivatives. The electron-withdrawing groups at the phenyl ring increased the inhibitory activity compared to electron-donating groups. 相似文献
88.
Belma Giray Filiz Hincal Tahsin Teziç Ayşenur Ökten Yusuf Gedik 《Biological trace element research》2001,82(1-3):35-52
In order to investigate the relations of iodine deficiency and/or goiter with selenium (Se) and antioxidant enzyme (AOE) status, we determined the relevant parameters of goitrous high school children living in an endemic goiter area of Turkey. Subjects were selected by a simple random sampling technique after screening the whole population of the high schools of two towns by neck palpation. The results of the goitrous group (n = 48, aged 15-18 yr) were compared with those of nongoitrous control children (n = 49) from the same populations, and with an outside control group (n = 24) from a lower-goiter-prevalence area. The overall prevalence of goiter was 39.6% in the high school population of the area. Activities of erythrocyte AOE (glutathion peroxidase, catalase, and superoxide dismutase) and concentrations of plasma and erythrocyte Se and urinary iodine were found to be significantly lower in goitrous children than both in-region and out-region of the control groups. When the whole study group was reclassified according to the severity of iodine deficiency, it was found that the AOE and Se status of those control children without goiter but with high iodine deficiency was significantly higher than goitrous children, although they did not differ from nondeficient control group. This might be the result of the possibility that goitrous children are exposed of oxidative stress, which may introduce alterations to the antioxidant defense system and/or the antioxidant status is relatively lower in goitrous children than those children who are highly iodine-deficient but did not develop goiter. The results of this study seem to support the view that the risk of goiter development may be higher in highly iodine-deficient children with lower enzymatic antioxidant and Se status. 相似文献
89.
Gülgez Gökçe Yıldız Mehmet Öztürk Belma Aslım 《World journal of microbiology & biotechnology》2011,27(10):2397-2406
Hypercholesterolemia has been reported to be the main cause of cardiovascular diseases and the leading cause of death. Therefore,
decreasing serum cholesterol level is very important for preventing the cardiovascular diseases. It has been supposed that
probiotics in human gastrointestinal tract have the ability to decrease serum cholesterol level by reducing the absorption
of cholesterol from the intestinal tract and the bile salt deconjugation. In this study, 28 strains of Lactobacillus spp., isolated from breast-fed infant’s feces, were identified and investigated for their bile salt deconjugation ability.
The deconjugation ability of the strains was determined by the release of cholic acid resulting from the deconjugation of
conjugated bile salts. Research results showed that four of the strains had bile salt deconjugation ability. The strains with
deconjugation ability have been identified in species level by using biochemical test, and molecular techniques, API 50CHL
test and 16S rRNA gene sequence analysis respectively. LP1, E3, and E9 strains with deconjugation activity were identified
as Lactobacillus rhamnosus and GD2 strain as Lactobacillus plantarum. Even if oxgall decreases the viability of bacteria, the highest amount of cholesterol precipitation (42%) was performed by
GD2 strain in the presence of 0.3% (w/v) bile. This study demonstrated that the identified Lactobacillus strains had an excellent ability to survive at low pH, a high bile deconjugation ability, and hypocholesterolemic effect
in in vitro conditions. 相似文献
90.