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101.
102.
Kalavrizioti D Vourekas A Tekos A Tsagla A Stathopoulos C Drainas D 《Molecular biology reports》2003,30(1):9-14
A cell-free system derived from Dictyostelium discoideum has been used to study the kinetics of inhibition of RNase P by puromycin, amicetin and blasticidin S. Detailed kinetic analysis showed that the type of inhibition of RNase P activity by puromycin is simple competitive, whereas the type of inhibition by amicetin and blasticidin S is simple non-competitive. On the basis of Ki values amicetin is stronger inhibitor than puromycin and blasticidin S. 相似文献
103.
104.
Gkinis G Tzakou O Iliopoulou D Roussis V 《Zeitschrift für Naturforschung. C, Journal of biosciences》2003,58(9-10):681-686
Essential oils of Nepeta parnassica, collected at different developmental stages, were analyzed by means of GC/MS. From the fifty-five identified constituents in samples A and B, representing 94.8% and 98.7% of the oils respectively, 4a(alpha),7alpha,7alpha(beta)-nepetalactone (22.0%), 1,8-cineole (21.1%), alpha-pinene (9.5%) and 4a(alpha),7,beta,7alpha(beta)-nepetalactone (7.9%) were the major components of sample A (vegetative stage), whereas in sample B (flowering stage) the main contributors were 1,8-cineole (34.6%), 4a(alpha),7alpha,7a(alpha)-nepetalactone (17.3%), alpha-pinene (11.4%) and 4a(alpha),7alpha,7alpha(beta)-nepetalactone (8.9%). The oils were tested on human health important insects such as the Pogonomyrmex sp. ants and the Culex pipiens molestus mosquitoes with promising results on insect repellency/toxicity. 相似文献
105.
Politi EN Lazaris AC Alexopoulou D Lambropoulou S Kavantzas N Koutselini H 《Analytical and quantitative cytology and histology / the International Academy of Cytology [and] American Society of Cytology》2004,26(4):187-193
OBJECTIVE: To detect argyrophilic nucleolar organizer regions (AgNORs) in ThinPrep (Cytyc Corp., Boxborough, Massachusetts, U.S.A.) liver fine needle aspiration (FNA) specimens and to define the diagnostic value of their quantitative analysis in the evaluation of hepatic lesions. STUDY DESIGN: ThinPrep liquid-based FNA biopsy specimens from 49 malignant and benign liver lesions were resampled, fixed in 95% ethanol and stained with the AgNOR technique in accordance with the 1-step colloid method. The specimens included 11 benign and 38 malignant lesions (23 poorly differentiated hepatocellular carcinomas [HCCs] and 15 poorly differentiated metastatic adenocarcinomas [MCs]). Morphometric analysis was performed using a Zeiss Axiolab microscope (Carl Zeiss GmbH, Jena, Germany) with a mechanical stage fitted with a Sony-iris CCD videocamera (Tokyo, Japan). The videocamera was connected to a Pentium III P/C (Intel Corp., Santa Clara, California, U.S.A.) loaded with the appropriate image analysis software. The measurements were performed with ImageScan software (Jandel Scientific, Erkrath, Germany). The number of AgNORs per nucleus (NN) and the total area per nucleus occupied by AgNORs (AR) were calculated semiautomatically. Statistical analysis was performed using the SPSS software package (Chicago, Illinois, U.S.A.). RESULTS: The least significant deviance test for multiple comparisons revealed that NN differed significantly between the 3 groups of samples examined (P < .0001). The mean NN values in HCCs and MCs were significantly different (P < .0001). Logistic regression model demonstrated that as NN increased, the probability of a MC diagnosis decreased (<4%). AR values were different at a statistically significant level only between benign and malignant specimens (P = .00006), not between HCCs and MCs (P = .933). CONCLUSION: Quantitative analysis of AgNORs in ThinPrep specimens could be a diagnostically useful method in liver disease. 相似文献
106.
Veneti S Daskalopoulou D Zervoudis S Papasotiriou E Ioannidou-Mouzaka L 《Acta cytologica》2003,47(2):188-192
OBJECTIVE: To compare the various cytologic features on AutoCyte Prep (ACP) (AutoCyte, Inc., Burlington, North Carolina, U.S.A.) and conventional preparation (CP) specimens from breast fine needle aspiration cytology material with a semi-quantitative scoring system. STUDY DESIGN: A total of 100 randomized cases were studied. In each case, 2 passes were performed. One pass was used for CPs (Giemsa and Papanicolaou stain). The other pass produced material for the ACP technique and Papanicolaou stain. Both the conventional and liquid-based preparations were studied independently by two observers and compared for cellularity, obscuring and/or informing background, representative diagnostic material, preservation of cytomorphologic features, presence of monolayer cells and architectural arrangement. RESULTS: Comparing the two preparations, the results were as follows: (1) ACP was superior to CP in 2 features, lack of obscuring background and presence of monolayer arrangement with preservation of cell architecture; (2) ACP was inferior to CP in 1 feature, lack of informing background; and (3) ACP was equal, with small deviations, to CP in the rest of the features evaluated: cellularity, representative diagnostic material, preservation of cell morphology and architectural arrangement. CONCLUSION: The new technology of liquid-based cytology in breast FNA showed a good correlation with CP plus the advantages of: (1) easier and less time consuming evaluation of cell morphology (clear background, no overlapping, smaller area to screen); (2) reproducibility, a factor of great importance to quality control; and (3) possibility of adjunctive investigations (immunocytology, flow cytometry) on the same material. 相似文献
107.
Michaelidou A Hadjipavlou-Litina D 《Journal of enzyme inhibition and medicinal chemistry》2003,18(6):537-544
The synthesis of some new aryl acetic acids and amides and a pharmacochemical study and quantitative structure-activity relationships (QSAR) on them are described. The compounds were screened for their biological activity using the carrageenin induced rat paw oedema model and a significant inhibition of oedema occurred (44.1-80.1%) at a concentration of 0.01 mmol/1 kg. The analgesic activity, based on the inhibition of acetic acid-induced writhing in rats was also found to be significant. The compounds were found to interact with the stable free radical 1,1-diphenylhydrazyl DPPH and with DMSO (for hydroxyl radicals). The compounds were screened for radical scavenging activity with the xanthine/xanthine oxidase system for O2-* and for inhibition of soybean lipoxygenase (LOX). The results are discussed in terms of the structural and physicochemical characteristics of the compounds. 相似文献
108.
Nikos T Kouris Maria D Sifaki Dimitra D Kontogianni Ioannis Zaharos Eleni M Kalkandi Haris E Grassos Dimitris K Babalis 《Cardiovascular ultrasound》2003,1(1):1-6
Background
It has been suggested that an extensive contractile reserve identified recognised by means of dobutamine stress echocardiography may predict a better prognosis in patients with severe left ventricular dysfunction at rest. However, the clinical use of dobutamine stress echocardiography may be limited in patients with chronic heart failure by the substantial proportion of such patients treated with beta-blockers, since the inotropic response to adrenergic stimulation is known to be attenuated in patients receiving beta-adrenoceptor blockers. Enoximone is a positive inotropic agent that inhibits cyclic adenosine monophosphate-specific phosphosdiesterase. We therefore tested the hypothesis that enoximone may be an alternative to dobutamine in evaluating left ventricular contractile reserve in patients with systolic dysfunction on chronic beta-blocker therapy.Methods
We studied 26 patients (21 males and five females) with a mean age of 58 ± 10 years: 11 were not receiving beta-blockers (noBB group); 15 were receiving carvedilol at a mean dose of 34 mg/day (BB group). Dobutamine was infused at doses of 5 and 10 micrograms/kg/min, and enoximone at a dose of 1.5 mg/kg.Results
The ejection fraction in the noBB group increased by 9% with dobutamine and 8.73% with enoximone (p = 0.86); in the BB group, it increased by 6% with dobutamine and 8.94% with enoximone (p = 0.03). Regional peak systolic velocities were evaluated by means of tissue Doppler imaging in four basal and four medium level segments. In the noBB group, they increased more with dobutamine than with enoximone in three of the eight segments; no significant differences were found in the BB group. Dobutamine induced non-sustained ventricular tachycardia in three patients and supraventricular tachycardia in one, whereas enoximone did not induce any repetitive arrhythmias.Conclusions
Enoximone might be preferable to low-dose dobutamine for evaluating left ventricular contractile reserve in chronically beta-blocked heart failure patients as it is slightly more potent and has a better safety profile. 相似文献109.
Dimitra Kovala-Demertzi Mavroudis A. Demertzis Eleni Filiou Anastasia A. Pantazaki Paras N. Yadav John R. Miller Yifan Zheng Dimitrios A. Kyriakidis 《Biometals》2003,16(3):411-418
The reactions of Pd(II) and Pt(II) with 2-Acetyl Pyridine N(4)-Ethyl-Thiosemicarbazones, HAc4Et and 2-Acetyl Pyridine N(4)-1-(2-pyridyl)-piperazinyl Thiosemicarbazone, HAc4PiPiz and 2-Formyl Pyridine N(4)-1-(2-pyridyl)-piperazinyl Thiosemicarbazone, HFo4PiPiz afforded the complexes, [Pd(Ac4Et)], 1, [Pd(HAc4Et)2]Cl2, 2 and [Pd(Ac4Et)2], 3[Pt(Ac4Et)], 4, [Pt(HAc4Et)2]Cl2, 5, [Pt(Ac4Et)2], 6 and [Pd(Fo4PipePiz)Cl], 7, [Pd(Fo4PipePiz)2], 8, [Pd(Ac4PipePiz)Cl], 9 and [Pd(Ac4PipePiz)2], 10. The crystal structure of the complex [Pt(Ac4Et)2], 6 has been solved. The platinum(II) atom is in a square planar environment surrounded by two cis nitrogen atoms and two cis sulfur atoms. The ligands are not equivalent, one being tridentate with (N,N,S) donation, the other being monodentate using only the sulfur atom to coordinate to the metal. The tridentate ligand shows a Z, E, Z configuration while the monodentate ligand shows an E, E, Z. Inter-molecular hydrogen bonds stabilize the structure, while the crystal packing is determined by –, and Pt – C interactions. The antibacterial effect of Pd(II) and Pt(II) complexes were studied in vitro. The complexes were found to have effect on Gram(+) bacteria, while the same complexes showed no bactericidal effect on Gram(–) bacteria. The effect of the Pd(II) and Pt(II) complexes on the in vitro DNA strand breakage was studied by agarose gel electrophoresis. The complexes 1-6 were found to exhibit a cytotoxic potency in a very low micromolar range and to be able to overcome the cisplatin resistance of A2780/Cp8 cells (Kovala-Demertzi et al. 2000). 相似文献
110.
Wim M. Van der Krieken Hans Breteler Marcel H. M. Visser Dimitra Mavridou 《Plant cell reports》1993,12(4):203-206
A test system for root regeneration was developed that consists of stem slices of apple shoots (ca. 0.5 mm thick; fresh weight ca. 1 mg). Roots regenerated synchronously without intervening callus formation and without interference with compounds originating from other parts of the plant. Supply of indolebutyric acid (IBA) or indoleacetic acid (IAA) induced maximally an average of 8 or 4.5 roots per slice, respectively. After uptake of IBA, a high degree of conjugation resulted in a recovery of 2.5% as internal free IBA (ca. 2 times the medium concentration). Due to conversion of absorbed IBA into IAA a fraction of 0.4% was recovered as (physiologically active) free IAA. After incubation on medium with IAA, 0.5% of the absorbed hormone was recovered in the free acid form. No conversion of IAA into IBA was observed. Equimolar contents of internal free IAA after incubation on IBA or IAA resulted for IBA in a higher number of roots than for IAA. This means that IBA may also act via internal free IBA or may synergistically modify the action or endogenous synthesis of IAA.Abbreviations BHT
butyl hydroxy toluene
- EtOH
ethanol
- FW
fresh weight
- HAc
acetic acid
- HPLC
high performance liquid chromatography
- IAA
indoleacetic acid
- IAAint
free (internal) IAA in the tissue derived from IBA or IAA uptake
- IBA
indolebutyric acid
- IBAint
free (internal) IBA in the tissue derived from IBA or IAA uptake
- MeOH
methanol
- PAR
photosynthetic active radiation
- SEM
standard error of the mean
- TLC
thin layer chromatography
- UV
ultra violet 相似文献