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H Minderman P P Brons P C Linssen A H Pennings J M Wessels J B Boezeman C Haanen 《Experimental hematology》1991,19(10):1008-1012
Cell kinetics of two human leukemic cell lines, Molt-4 and K562, following a 2-h exposure to doxorubicin, were studied. DNA flow cytometry provided static information that for both cell lines a dose-dependent accumulation occurred at the G2 + M compartment that disappeared in time. Kinetic information was provided by time-monitoring cells labeled with 5-iodo-2-deoxyuridine (IdUrd) by two-parameter flow cytometry, analyzing the IdUrd label and the DNA content. The cell-cycle time (Tc) of exponentially growing Molt-4 cells was determined to be 20 h. Twenty-four hours after a 2-h exposure to 0.25 micrograms/ml doxorubicin, the Tc had increased to 23 h; following exposure to 1.0 micrograms/ml, it increased to 33 h. Cell kinetics of K562 cells following doxorubicin exposure were monitored in time up to 4 days. The average Tc of exponentially growing K562 cells was determined to be 24.7 h. Twenty-four hours following 2-h exposure to 0.25 or 0.5 micrograms/ml doxorubicin, the Tc were determined to be 28 and 32 h, respectively. After an additional 2 days, the Tc were both determined to be 24 h. The dose-dependent, reversible cell-cycle delay that persisted at least 48 h should be taken into account as an additional mode for decrease of a (tumor) cell population doubling time after exposure to doxorubicin. 相似文献
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Intracorporeal suturing is essential to advanced laparoscopy and is a rate-limiting step in many procedures. We have outlined an improved method of intracorporeal knot tying which is easier to learn, faster, and more consistently performed than current methods. Conventional intracorporeal knot-tying technique was compared to the knit-stitch method by ten volunteer surgeons. Each participant tied ten conventional-style knots in a video trainer. Surgeons were then taught the knit-stitch method and tied an additional ten knots. Knot-tying times were recorded and compared. Participants were asked to choose the method they preferred. The knit-stitch method was demonstrated to be faster than the conventional method for all participants, regardless of level of training or laparoscopic expertise (mean 63±19 vs 97±48 s; P<0.001). The difference was most marked in participants with the least laparoscopic suturing experience. The knit-stitch was preferred by 90% of the surgeons. Reasons cited for this preference were ease of learning, conservation of instrument motion, better utilization of the nondominant hand, and ability to work with shorter suture.Knit stitching is a faster, more consistent method of intracorporeal suturing. It is preferred because of its simplicity, efficiency, and potential to further reduce tissue trauma during the course of laparoscopic suturing. 相似文献
4.
Pennings RJ Te Brinke H Weston MD Claassen A Orten DJ Weekamp H Van Aarem A Huygen PL Deutman AF Hoefsloot LH Cremers FP Cremers CW Kimberling WJ Kremer H 《Human mutation》2004,24(2):185
Usher syndrome type II (USH2) is characterised by moderate to severe high-frequency hearing impairment, progressive visual loss due to retinitis pigmentosa and intact vestibular responses. Three loci are known for USH2, however, only the gene for USH2a (USH2A) has been identified. Mutation analysis of USH2A was performed in 70 Dutch USH2 families. Ten mutations in USH2A were detected, of which three are novel, c.949C>A, c.2242C>T (p.Gln748X) and c.4405C>T (p.Gln1468X). Including 9 previously published Dutch USH2a families, estimates of the prevalence of USH2a in the Dutch USH2 population were made. Mutations were identified in 62% of the families. In 28% both mutated alleles were identified, whereas in 34% the mutation in only one allele was found. It is estimated that about 28% of the Dutch USH2 families have a different causative gene. Analysis of deduced haplotypes suggests that c.1256G>T (p.Cys419Phe) is a Dutch ancestral mutation, occurring in 16% of the alleles. 相似文献
5.
Copolymers of L -lactide with D -lactide 1 According to IUPAC the name dilactide is preferred to lactide. , glycolide 2 IUPAC name: diglycolide. , ε-caprolactone and trimethylene carbonate, and networks with spiro-bis-dimethylene-carbonate (2,4,7,9-tetraoxaspiro[5.5]undecane-3,8-dione) were prepared in bulk at standardized polymerization conditions. The properties of the nascent copolymers were evaluated with respect to the nature of the comonomer. Copolymerization with comonomers entailing low glass transition temperature simultaneously reduces the crystallinity. 300 MHz 1H nuclear magnetic resonance is shown to be a useful technique for the determination of the average monomer sequence lengths in ε-caprolactone and trimethylene carbonate copolymers. The presence of crystallizable L -lactide sequences, due to differences in monomer reactivity, has a large effect on the thermal properties of the copolymer as well as on the long-term degradation characteristics. 相似文献
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Unraveling toxicological mechanisms and predicting toxicity classes with gene dysregulation networks
Tessa E. Pronk Eugene P. van Someren Rob H. Stierum Janine Ezendam Jeroen L.A. Pennings 《Journal of applied toxicology : JAT》2013,33(12):1407-1415
The use of genes for distinguishing classes of toxicity has become well established. In this paper we combine the reconstruction of a gene dysregulation network (GDN) with a classifier to assign unseen compounds to their appropriate class. Gene pairs in the GDN are dysregulated in the sense that they are linked by a common expression pattern in one class and differ in this pattern in another class. The classifier gives a quantitative measure on this difference by its prediction accuracy. As an in‐depth example, gene pairs were selected that were dysregulated between skin cells treated with either sensitizers or irritants. Pairs with known and novel markers were found such as HMOX1 and ZFAND2A, ATF3 and PPP1R15A, OXSR1 and HSPA1B, ZFP36 and MAFF. The resulting GDN proved biologically valid as it was well‐connected and enriched in known interactions, processes and common regulatory motifs for pairs. Classification accuracy was improved when compared with conventional classifiers. As the dysregulated patterns for heat shock responding genes proved to be distinct from those of other stress genes, we were able to formulate the hypothesis that heat shock genes play a specific role in sensitization, apart from other stress genes. In conclusion, our combined approach creates added value for classification‐based toxicogenomics by obtaining novel, well‐distinguishing and biologically interesting measures, suitable for the formulation of hypotheses on functional relationships between genes and their relevance for toxicity class differences. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
8.
Michiel J. Vanfleteren Maud Koopman Martijn A. Spruit Herman-Jan Pennings Frank Smeenk Willem Pieters Jan J. van den Bergh Arent-Jan Michels Emiel F. Wouters Miriam T. Groenen Frits M. Franssen Lowie E. Vanfleteren 《Archives of physical medicine and rehabilitation》2018,99(11):2279-2286.e3
Objective
To evaluate the effect of pulmonary rehabilitation (PR) on exercise performance and quality of life in patients with chronic obstructive pulmonary disease (COPD) with different degrees of static lung hyperinflation (LH).Design
Retrospective cohort study.Setting
PR network.Participants
A cohort of 1981 patients with COPD (55% men; age: 66.8±9.3y; forced expiratory volume in the first second%: 50.7±19.5; residual volume [RV]%: 163.0±49.7).Intervention
An interdisciplinary PR program for patients with COPD consisting of 40 sessions.Main Outcome Measures
Participants were stratified into 5 quintiles according to baseline RV and were evaluated on the basis of pre- and post-PR 6-minute walk distance (6MWD), constant work rate test (CWRT), and Saint George’s Respiratory Questionnaire (SGRQ), among other clinical parameters.Results
With increasing RV quintile, patients were younger, more frequently women, had lower forced expiratory volume in the first second%, lower body mass index and fat-free mass index, shorter 6MWD, shorter CWRT, and worse SGRQ scores (P<.01). All RV strata improved after PR in all 3 outcomes (P<.001). Nevertheless, higher, compared to lower RV categories, had lower ΔCWRT (P<.01) but similar Δ6MWD (P=.948) and ΔSGRQ (P=.086) after PR.Conclusions
LH in COPD is related to younger age, female sex, lower body weight, worse exercise capacity and health status, but did not prevent patients from benefitting from PR. LH, however, influences walking and cycling response after PR differently. 相似文献9.
The fetal brain transcriptome and neonatal behavioral phenotype in the Ts1Cje mouse model of Down syndrome 下载免费PDF全文
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