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The effect of the cyclin-dependent (CDK) inhibitors olomoucine and roscovitine on cell kinetics was studied. To this end, nonsmall cell lung cancer (NSCLC) cell line MR65 and neuroblastoma cell line CHP-212 were pulse labeled with bromodeoxyuridine (BrdUrd) and chased in culture medium, to which various concentrations of olomoucine or roscovitine were added. A dose-dependent inhibition of the G1/S-phase and G2/ M-/G1 transitions was observed. Furthermore, S-phase progression was also inhibited in a dose-dependent manner. Similarly, roscovitine, another CDK inhibitor with a 10-fold higher efficiency for both CDK1 and CDK2 as compared to olomoucine, showed the same effects at a 10-fold lower concentration. At the highest tested doses both olomoucine (200 microM) and roscovitine (40 microM) induced a complete cell cycle block in both cell lines, paralleled by the appearance of apoptotic figures. In these cultures a decrease in CDK1 protein level was found as shown by Western blotting. Bivariate CDK1/DNA analysis confirmed these observations and showed that a subpopulation of cells with characteristics of apoptosis became CDK1 negative. The presented data suggest that cyclins and CDKs are involved at an important nodal point shared by pathways regulating cellular proliferation and apoptosis.  相似文献   
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The use of physical techniques such as scanning electron microscopy and microprobe analysis permits the analysis of valuable details of the structure of dried samples of mid-cycle cervical mucus during the period of maximum ferning. From a crystallographic point of view, particular attention was paid to the location, morphology and chemical composition of anisotropic organic sulphate microstructures. As distinct from the isotropic sodium chloride pattern described by Papanicolaou, these appear in a narrow period of time corresponding to the middle of the period of maximum ferning. Anisotropic microstructures were revealed to be tiny isolated crystals or polycrystalline aggregates composed of double salts of potassium and sodium. The potassium/sodium cation ratio, equal to 3/1, was constant in the best specimens. Using a simple polarizing microscope, the detection of anisotropic microstructures may be useful to determine the period of maximum fertility more accurately. In addition, experiments have been carried out in order to determine the relative importance of sulphate anisotropic structures as compared with the whole crystallized surface and to investigate precisely their transience after they appear.  相似文献   
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The popular literature has publicized the adjustment difficulties of adult children of an alcohol-dependent parent (ACOAs); however, empirical studies do not provide consistent support. We examined the impact of parental alcoholism, degree of childhood socio-economic stress and gender on three broad categories of adulthood functioning (psychopathology, socio-economic attainment and marital stability). These effects were investigated with a heterogeneous sample of 400 men and 226 women participating in studies at the University of Michigan Alcohol Research Center. Parental alcoholism and childhood socio-economic stress exerted significant independent effects on most adulthood functioning measures. Men and women differed substantially only on socio-economic attainment measures, and effects of parental alcoholism and childhood economic stress on men and women were generally similar. For marital stability, parental alcoholism and childhood socio-economic stress interacted. These results suggest that researchers who study the impact of family history for alcoholism on psychological functioning should consider other aspects of the family of origin that promote wellbeing. In addition, results of this study point to the need for more research on gender differences, protective factors that promote good adjustment and outcome measures reflecting general life adaptation.  相似文献   
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The pupal defensive secretion of the coccinellid beetle Epilachna borealis is composed principally of a combinatorial library of macrocyclic polyamines. These compounds constitute a previously unrecognized family of natural products, characterized by extremely large-ring lactonic structures derived from a small set of (2-hydroxyethylamino)alkanoic acids. The combinatorial assembly of these simple building blocks generates a high degree of structural diversity, which is further increased by slow, spontaneous intramolecular rearrangement of the macrocycles.  相似文献   
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BACKGROUND: Subvalvular preservation is necessary to maintain left ventricular function, but accidental retention of infected tissue could cause postoperative endocarditis. METHODS: We examined 71 consecutive patients who underwent operation for mitral endocarditis. Endocarditis was uncontrolled and active in 24 patients, partially treated (unfinished antibiotic course) in 17, and healed in 30. RESULTS: Valves were repaired in 17% versus 59% versus 63% and replaced with subvalvular preservation in 25% versus 6% versus 3% of the uncontrolled active, partially treated, and healed groups, respectively. Thirty-day mortality was 29% versus 0% versus 3.3% (p=0.003), total mortality was 46% versus 18% versus 17% (p=0.035), and complications-related mortality was 38% versus 11% versus 13% (p=0.054), respectively. There was a trend toward lower complications-related mortality with subvalvular preservation than without. Postoperative endocarditis occurred in 3 of 30 patients without and 1 of 41 patients with subvalvular preservation. CONCLUSIONS: Postoperative mortality in uncontrolled active mitral endocarditis remains high, but results are good with partially treated or healed endocarditis. Subvalvular preservation improves outcome, does not increase postoperative endocarditis rates, and should be performed whenever feasible.  相似文献   
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Radiolabeling permits the detection of trace amounts of zwitterionic detergent remaining in extracted hydrophobic or membrane proteins. To develop a sensitive and specific assay for its presence, the commonly used zwitterionic membrane protein detergent 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (Chaps) was synthesized in a tritiated form. Synthesis via 7-ketodeoxycholic acid gave [7-3H]Chaps in 53% yield with a specific activity of 0.85 mCi/mmol. A novel solvent extraction system for cholic acid obviated the need for chromatographic isolation of this intermediate. The protocol can be readily modified to yield [7-3H]Chaps of higher specific activity. [7-3H]Chaps was used to monitor the efficiency of various strategies for detergent removal from concentrated bacterial culture supernatants containing 0.2% (w/v) Chaps. Dialysis removed 95% of Chaps and the addition of detergent-affinity beads to the dialysis buffer resulted in 97% removal of Chaps. Gel-filtration chromatography removed 99.9% of Chaps, while a detergent-affinity bead chromatography column removed 99.99%. Overall, gel-filtration chromatography was the most convenient and economical method for the one-step removal of the zwittergent from complex biological mixtures.  相似文献   
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