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91.
The spectrometric analysis of extracts from tobacco and tobacco smoke revealed the presence of pentobarbital in the analyzed substances. Tobacco samples and tobacco smoke were extracted with chloroform, determinations were performed with the Perkin-Elmer Autosystem XL system, on a Turbo Mass spectrometer. Subject to analysis were 4 cigarette brands manufactured in Poland and raw, unprocessed tobacco. The presence of pentobarbital in the analyzed samples was confirmed by the analysis of the mass spectrum of the substance, as well as by comparison of retention time with standard of pentobarbital. The determined pentobarbital concentrations in tobacco amounted to 3-6 microg/cigarette, and in tobacco smoke they were approximately 45% lower. In case of tobacco extracts it can with high probability be excluded that pentobarbital is synthesized during chromatographical analysis. The presence of pentobarbital in tobacco is thus beyond question. 相似文献
92.
The aim of this study was to evaluate the influence of female sex hormones on phenazone pharmacokinetics using as an experimental model female rabbits after a bilateral ovariectomy. Eighteen female rabbits divided into two groups: control animals and experimental rabbits, that underwent ovariectomy, were used in the study. Pharmacokinetic assays were performed in all animals: prior to the study, after 1 month and after 2 months. Blood was sampled within 24 hours after intragastric administration of phenazone at a dose 50 mg/kg b.w. Two compartment open model was used for calculations. Significant increase in AUC and prolongation of phenazone halflife as well as a decrease in the total body clearance were noted. The study demonstrated the possible inhibition of the microsomal mixed-function oxidase system by oestrogens. 相似文献
93.
94.
Anna Gasinska Jan Skolyszewski Tadeusz Popiela Piotr Richter Zbigniew Darasz Krystyna Nowak Joanna Niemiec Beata Biesaga Agnieszka Adamczyk Krzysztof Bucki Krzysztof Malecki Marian Reinfuss Teresa Kowalska 《Journal of gastrointestinal surgery》2007,11(4):520-528
Purpose Assessment of tumor proliferation rate using Bromodeoxyuridine labeling index (BrdUrdLI) as a possible predictor of rectal
cancer response to preoperative radiotherapy (RT).
Methods and material Ninety-two patients were qualified either to short RT (5 Gy/fraction/5 days) and surgery about 1 week after RT (schedule I),
or to short RT and 4–5 weeks interval before surgery (schedule II). Tumor samples were taken twice from each patient: before
RT and at the time of surgery. The samples were incubated with BrdUrd for 1 h at 37°C, and the BrdUrdLI was calculated as
a percentage of BrdUrd-labeled cells.
Results Thirty-eight patients were treated according to schedule I and 54 patients according to schedule II. Mean BrdUrdLI before
RT was 8.5% and its value did not differ between the patients in the two compared groups. After RT tumors showed statistically
significant growth inhibition (reduction of BrdUrdLI). As the pretreatment BrdUrd LI was not predictive for early clinical
and pathologic tumor response, prognostic role of the ratio of BrdUrdLI after to BrdUrdLI before RT was considered. The ratios
were calculated separately for fast (BrdUrd LI > 8.5%) and slowly (BrdUrd LI ≤ 8.5%) proliferating tumors and correlated with
overall treatment time (OTT, i.e., time from the first day of RT to surgery). One month after RT, accelerated proliferation
was observed only in slowly proliferating tumors.
Conclusions Pretreatment BrdUrdLI was not predictive for early clinical and pathologic tumor response. The ratio after/before RT BrdUrdLI
was correlated to inhibition of proliferation in responsive tumors.
The paper was presented at ECCO 13, October 30 to November 03, 2005 in Paris, France 相似文献
95.
Anna Gliszczyńska-Swig?o Hester van der Woude Laura de Haan Bozena Tyrakowska Jac M M J G Aarts Ivonne M C M Rietjens 《Toxicology in vitro》2003,17(4):423-431
The effects of quercetin on viability and proliferation of Chinese Hamster Ovary (CHO) cells and CHO cells overexpressing human quinone reductase (CHO+NQO1) were studied to investigate the involvement of the pro-oxidant quinone chemistry of quercetin. The toxicity of menadione was significantly reduced in CHO+NQO1 cells compared to wild-type CHO cells, validating the NQO1-overexpression in the CHO+NQO1 transfectant. Quercetin inhibited the proliferation of wild-type CHO and CHO+NQO1 cells to a similar extent without affecting cell viability, indicating that NQO1 enrichment of CHO cells did not provide increased protection. On the other hand, inhibition of NQO1 in both types of cells by dicoumarol significantly potentiated the inhibitory effect of quercetin on cell proliferation, revealing the role of NQO1 in cellular protection against quercetin. Altogether, these results can be explained by the hypothesis that both wild-type CHO and CHO+NQO1 cells contain sufficient NQO1 activity for optimal protection against the pro-oxidant effect of quercetin on cell proliferation. The results also point at a cellular NQO1 threshold for optimal protection against quercetin. This NQO1 threshold seems to be in the range of NQO1 activities already present in various tissues. 相似文献
96.
Mieczysaw Pokorski Zdzisaw Matysiak Magdalena Marczak Robert P. Ostrowski Andrzej Kapuciski Iwona Matuszewska Marianna Kaska Zbigniew Czarnocki 《Drug development research》2003,60(3):217-224
N‐acyl‐dopamines are a novel class of biologically active lipids that have recently been identified in the brain and have the potential to interact with neural signaling pathways. This study seeks to determine the ability of N‐oleoyl‐dopamine, a synthetic amide of oleic acid and dopamine, to cross the blood brain barrier. We determined the tissue content of radioactivity in selected brain regions, in a short‐run study design, following injections of [3H]N‐oleoyl‐dopamine (0.4 µCi) into the internal carotid artery in the rat. These results were compared with intracarotid injections of [3H]dopamine and with intravenous injections of both radiolabeled compounds. The level of radioactivity was determined using liquid scintillation and was expressed as the percentage of its total dose injected per gram of tissue. We found that the 15‐min brain uptake of radioactivity, with no distinct regional variations, amounted to about 6% following the intracarotid [3H]N‐oleoyl‐dopamine, which was a significant 3–4‐fold increase over that following similar administration of [3H]dopamine. Intravenous injections of [3H]N‐oleoyl‐dopamine gave a much smaller yield of radioactivity in brain tissue samples which was still severalfold greater than that for intravenous [3H]dopamine. Qualitative thin‐layered chromatography screening showed the presence of unchanged N‐oleoyl‐dopamine in the brain following injections. We conclude that N‐oleoyl‐dopamine has an appreciable ability to cross the blood‐brain barrier, which contrasts the limited transfer of dopamine alone. N‐oleoyl‐dopamine might exert physiological effects due to its known affinity for the central vanilloid receptors or to better satisfying the brain tissue demand for dopamine. The study suggests a potential pharmacological role for N‐oleoyl‐dopamine delivered exogenously in helping regulate the brain function. Drug Dev. Res. 60:217–224, 2003. © 2003 Wiley‐Liss, Inc. 相似文献
97.
E Przegaliński A M Ismaiel E Chojnacka-Wójcik B Budziszewska E Tatarczyńska E B?aszczyńska 《Neuropharmacology》1990,29(6):521-526
The 5-HT1A receptor antagonistic properties of 1-(2-methoxyphenyl)-4-[4-(2-phthalimmido)butyl] piperazine (NAN-190) were studied in rats: its effect on the 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT)-induced behavioural syndrome (flat body posture and reciprocal forepaw treading), hypothermia and secretion of corticosterone, i.e. responses mediated by 5-HT1A receptors, were examined. The drug NAN-190 (1-8 mg/kg) antagonized dose-dependently behavioural effects of 8-OH-DPAT (in both non-reserpinized and reserpine-pretreated animals); however, when administered in doses of 0.5-4 mg/kg, it did not affect the hypothermic or the hormonal response to 8-OH-DPAT. However, NAN-190 (1-8 mg/kg) given alone, produced hypothermia and increased the concentration of corticosterone in serum. The latter effects of NAN-190 were not reduced by (-)pindolol or spiperone. Moreover, the NAN-190-induced secretion of corticosterone was not affected by ketanserin, prazosin or yohimbine. The above results indicate that NAN-190 acts as a 5-HT1A receptor antagonist, only in the model of the 8-OH-DPAT-induced behavioural syndrome. The lack of effect of NAN-190 on the hypothermic or corticosterone response to 8-OH-DPAT most probably results from its own action which mimics the effects of 8-OH-DPAT. The mechanisms responsible for the NAN-190-induced hypothermia and secretion of corticosterone are still unknown, though stimulation of 5-HT1A receptors (either effect), 5-HT2 receptors and alpha 1- and alpha 2-adrenoceptors (corticosterone response) seems to be excluded. 相似文献
98.
J. Marowska M. Kobylińska J. ?ukaszkiewicz A. Ta?ajko B. Rymkiewicz-Kluczyńska R.S. Lorenc 《BONE》1996,19(6):669-677
The aim of our study was to establish normal values of urinary pyridinoline (Pyr) and deoxypyridinoline (DPyr) excretion for children aged 3–18 years, examine the biological variability of the marker, and assess its clinical value for pediatric patients with growth hormone deficiency. Pyr and DPyr was measured in first void urine samples from 692 healthy subjects (340 boys, 352 girls) by high-performance liquid chromatography. At sampling, age, body height, and weight was recorded for all individuals. Short-term variability in crosslinks excretion was examined in four healthy children. The clinical value of the marker was studied in seven patients with growth hormone (GH) deficiency. In childhood, crosslinks excretion exceeded normal adult values by about fivefold and declined during puberty. In the age range of 13–18 years, gender-related differences in Pyr and DPyr levels were observed, presumably resulting from the earlier onset of puberty in girls. Urinary levels of Pyr and DPyr were highly correlated both in males and females. Pyr/DPyr ratio was significantly higher in adolescents than children, suggesting enhanced release of Pyr from extraosseous sources. In both genders, neither age nor anthropometric variables showed a linear effect on crosslinks excretion. The range of within-subject, short-term variability in urinary Pyr and DPyr was relatively high (CV: 6%–21%), indicating that single measurements of crosslinks excretion may not adequately reflect bone resorption rates in children. Pyr and DPyr levels were significantly lower in GH-deficient patients and normalized during human growth hormone (hGH) therapy. Significant correlations between growth velocity (GV) and crosslinks levels were found, but individual prediction of GV increment during hGH treatment may be inaccurate. Pyr/DPyr ratio was not related to GV. It is concluded that measurement of urinary Pyr and DPyr excretion in children may be a valuable tool to assess bone resorption rates in population-based studies. In individual patients, however, only qualitative evaluation of disease severity and response to treatment seems justified. 相似文献
99.
A. Dmoszyńska-Giannopoulou L. Janicka B. Sokołowska A. Ksi⇂żek G. Orłowska K. Janicki 《International urology and nephrology》1990,22(6):561-566
In 30 patients on chronic haemodialysis treatment the platelet activity and function were studied before and during antiplatelet
therapy with alpha-tocopherol and sulphinpyrazone. In both kinds of treatment a significant decrease of ADP-induced and spontaneous
aggregation was observed. Sulphinpyrazone exerts an inhibitory effect not only on platelet aggregation but also on platelet
factor 3 and provokes a significant prolongation of the bleeding time. 相似文献
100.