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Identifying bacteriorhodopsin light-induced artefacts in time-resolved crystallography. ACTA CRYSTALLOGRAPHICA SECTION A FOUNDATIONS AND ADVANCES 2022. [DOI: 10.1107/s2053273322093251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2023]
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Increased self-reported delay of gratification in acutely underweight, but not remitted anorexia nervosa. Int J Eat Disord 2022; 55:135-140. [PMID: 34799878 DOI: 10.1002/eat.23644] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 10/15/2021] [Accepted: 11/07/2021] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Laboratory experiments using delay discounting tasks have delivered some evidence of an increased capacity to delay reward in anorexia nervosa (AN). Overall, however, findings have been inconclusive and no comprehensive studies of self-reported tendency to forgo immediate gratification in favor of long-term rewards exist in AN. METHOD A total of 71 acutely underweight female inpatients with AN (acAN); 52 women long-term weight-recovered from AN (recAN); and 120 healthy control women completed the Delaying Gratification Inventory (DGI). Fifty-two acAN were reassessed after short-term weight rehabilitation. Separate cross-sectional and longitudinal group comparisons tested for differences in DGI subscales (food, physical pleasure, social interaction, money, and achievement) and total scores. RESULTS DGI scores were elevated in acAN even after removing food-related items and accounting for comorbid symptoms. DGI scores remained relatively elevated following short-term weight rehabilitation, but no differences were evident between recAN and HC. DISCUSSION This study delivers self-report evidence supporting the notion of an increased propensity to delay gratification in individuals acutely ill with AN which does not appear to change with partial weight restoration alone. A reduction in the tendency to delay reward may thus be an important cognitive correlate of long-term recovery in AN.
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Decreased cerebral Irp-1B limits impact of social isolation in wild type and Alzheimer's disease modeled in Drosophila melanogaster. GENES BRAIN AND BEHAVIOR 2018; 17:e12451. [PMID: 29251829 DOI: 10.1111/gbb.12451] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 12/13/2017] [Accepted: 12/13/2017] [Indexed: 11/27/2022]
Abstract
Environmental factors, such as housing conditions and cognitively stimulating activities, have been shown to affect behavioral phenotypes and to modulate neurodegenerative conditions such as Alzheimer's disease (AD). AD is a progressive neurodegenerative disorder affecting cognitive functions. Epidemiological evidence and experimental studies using rodent models have indicated that social interaction reduces development and progression of disease. Drosophila models of Aβ42-associated AD lead to AD-like phenotypes, such as long-term memory impairment, locomotor and survival deficits, while effects of environmental conditions on AD-associated phenotypes have not been assessed in the fly. Here, we show that single housing reduced survival and motor performance of Aβ42 expressing and control flies. Gene expression analyses of Aβ42 expressing and control flies that had been exposed to different housing conditions showed upregulation of Iron regulatory protein 1B (Irp-1B) in fly brains following single housing. Downregulating Irp-1B in neurons of single-housed Aβ42 expressing and control flies rescued both survival and motor performance deficits. Thus, we provide novel evidence that increased cerebral expression of Irp-1B may underlie worsened behavioral outcome in socially deprived flies and can additionally modulate AD-like phenotypes.
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Effects of hyperthermic baths on depression, sleep and heart rate variability in patients with depressive disorder: a randomized clinical pilot trial. Altern Ther Health Med 2017; 17:172. [PMID: 28351399 PMCID: PMC5371197 DOI: 10.1186/s12906-017-1676-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Accepted: 03/10/2017] [Indexed: 12/28/2022]
Abstract
Background Despite advances in the treatment of depression, one-third of depressed patients fail to respond to conventional antidepressant medication. There is a need for more effective treatments with fewer side effects. The primary aim of this study was to determine whether hyperthermic baths reduce depressive symptoms in adults with depressive disorder. Methods Randomized, two-arm placebo-controlled, 8-week pilot trial. Medically stable outpatients with confirmed depressive disorder (ICD-10: F32/F33) who were moderately depressed as determined by the 17-item Hamilton Scale for Depression (HAM-D) score ≥18 were randomly assigned to 2 hyperthermic baths (40 °C) per week for 4 weeks or a sham intervention with green light and follow-up after 4 weeks. Main outcome measure was the change in HAM-Dtotal score from baseline (T0) to the 2-week time point (T1). Results A total of 36 patients were randomized (hyperthermic baths, n = 17; sham condition, n = 19). The intention-to-treat analysis showed a significant (P = .037) difference in the change in HAM-Dtotal score with 3.14 points after 4 interventions (T1) in favour of the hyperthermic bath group compared to the placebo group. Conclusions This pilot study suggests that hyperthermic baths do have generalized efficacy in depressed patients. Trial registration DRKS00004803at drks-neu.uniklinik-freiburg.de, German Clinical Trials Register (registration date 2016-02-02), retrospectively registered. Electronic supplementary material The online version of this article (doi:10.1186/s12906-017-1676-5) contains supplementary material, which is available to authorized users.
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Pomegranate (Punica granatum) Seed Oil for Treating Menopausal Symptoms: An Individually Controlled Cohort Study. Altern Ther Health Med 2017; 23:28-34. [PMID: 28323626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Context • In the folk medicine of Mediterranean countries and in ancient Ayurveda, Punica granatum seeds (ie, pomegranate seeds) have been used for treatment of various disorders, including those that nowadays are classified as menopausal symptoms (MSs). Pomegranate seed oil (PSO) from those seeds mainly contains unsaturated fatty acids such as γ-linoleic acid and linolenic acid, but it also includes phytoestrogens. It is, therefore, regarded as a promising option for treating MSs today. Objectives • The study intended to investigate the safety and effectiveness of PSO as a defined P granatum seed oil for patients with MSs. Design • The research team designed an individually controlled, investigator-initiated cohort study. Setting • The treatments were performed at 2 institutions: (1) the Center for Complementary Medicine at the University Medical Center Freiburg (Freiburg, Germany); and (2) in the medical practice of H. Fischer (Freiburg, Germany). Participants • Seventy-eight patients, who had a mean duration of MSs of 46 mo, participated in the study. Intervention • After 4 wk without treatment, which functioned as a period providing an individual control, each participant took 1000 mg of PSO daily in 2 capsules for 8 wk. Outcome Measures • The symptom severity was scored on the German version of the menopausal rating scale (MRS) at baseline, after 4 wk without treatment, after 4 wk of treatment, and postintervention, with 0 = absence of symptoms and 4 = very strong symptoms. The efficacy and tolerability were estimated on scales from 0-4. Each participant's 17ß estradiol was determined at baseline and after postintervention using the patient's sera. The content of the β-sitosterol was determined in the PSO preparations by gas chromatography. Results • The content of β-sitosterol in the PSO used in the study was 6.3 mg/1000 mg. In the intention to treat analysis, most MRS symptoms were significantly and relevantly reduced (eg, hot flushes changed from 2.32 ± 1.04 to 1.41 ± 1.07, P < .001). Remarkably, urogenital tract symptoms (ie, a dry vagina) also significantly improved, moving from 1.32 ± 1.43 to 0.85 ± 1.19, P < .001. Few patients reported gastrointestinal symptoms. The tolerability was excellent at 3.69 ± 0.71 after 4 wk of treatment and 3.71 ± 0.65 after 8 wk of treatment. The 17ß estradiol was unchanged. Conclusions • Participants showed significant improvements in all domains of the MRS, remarkably including the difficult-to-treat urogenital symptoms. No changes occurred in the 17ß-estradiol in patients' sera after the PSO treatment. The results are promising and encourage the investigation of PSO rich in β-sitosterol for treatment of MSs in placebo-controlled studies.
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Fever Therapy With Intravenously Applied Mistletoe Extracts for Cancer Patients: A Retrospective Study. Integr Cancer Ther 2016; 16:479-484. [PMID: 27387685 PMCID: PMC5739132 DOI: 10.1177/1534735416658121] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Purpose. So-called spontaneous remissions in cancer often seem to occur after febrile events. Mistletoe preparations (MPs) are used off-label intravenously to induce fever within concepts of integrative oncology. We wanted to investigate the frequency of febrile reactions and safety related to intravenously applied MPs (IAMPs). Methods. This was a retrospective analysis of data from consecutive cancer patients who were treated in 2 anthroposophic hospitals with IAMPs. The main outcome parameter was the rate of core temperature increase to ≥38.5°C within 24 hours after IAMPs. Secondary outcome parameters were Common Toxicity Criteria for Adverse Events (CTCAE; version 4.0). Results. 59 patients, with in total 567 IAMPs, were analyzed; 45 patients (76%, 95% CI = 65%-87%) had an increase of core temperature to ≥38.5°C after at least 1 treatment. Mean increase in temperature was 1.5°C ± 0.8°C. Adverse events were mostly fever-related symptoms (headache, joint pain, shivering). Grade 1 allergic reactions were documented in 0.6% of treatments. CTCAEs grade 3 to 5 did not occur; 38/59 patients had advanced and/or metastatic disease. Conclusion. IAMPs resulted in febrile reactions to >38.5°C in the majority of patients and can be considered as safe. Adverse events were mostly related to fever and were not severe.
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Efficacy of hot baths in patients with depression. Eur J Integr Med 2015. [DOI: 10.1016/j.eujim.2015.09.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Structure and mechanism of the diiron benzoyl coenzyme A epoxidase BoxB. Acta Crystallogr A 2011. [DOI: 10.1107/s0108767311080512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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The replication fork's five degrees of freedom, their failure and genome rearrangements. Curr Opin Cell Biol 2009; 21:778-84. [PMID: 19913398 DOI: 10.1016/j.ceb.2009.10.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Revised: 10/09/2009] [Accepted: 10/10/2009] [Indexed: 12/20/2022]
Abstract
Genome rearrangements are important in pathology and evolution. The thesis of this review is that the genome is in peril when replication forks stall, and stalled forks are normally rescued by error-free mechanisms. Failure of error-free mechanisms results in large-scale chromosome changes called gross chromosomal rearrangements, GCRs, by the aficionados. In this review we discuss five error-free mechanisms a replication fork may use to overcome blockage, mechanisms that are still poorly understood. We then speculate on how genome rearrangements may occur when such mechanisms fail. Replication fork recovery failure may be an important feature of the oncogenic process. (Feedback to the authors on topics discussed herein is welcome.).
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Details and concerns regarding the G2/M DNA damage checkpoint in budding yeast. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2003; 65:433-41. [PMID: 12760059 DOI: 10.1101/sqb.2000.65.433] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Abstract
As recently as six years ago, three human diseases with similar phenotypes were mistakenly believed to be caused by a single genetic defect. The three diseases, Ataxia-telangiectasia, Nijmegen breakage syndrome, and an AT-like disorder are now known, however, to have defects in three separate genes: ATM, NBS1, and MRE11. Furthermore, new recent studies have shown now that all three gene products interact; the ATM kinase phosphorylates NBS1, which, in turn, associates with MRE11 to regulate DNA repair. Remarkably or expectedly, depending on one's point of view, the similarity in disease phenotypes is evidently due to defects in a common DNA repair pathway.
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Saccharomyces cerevisiae checkpoint genes MEC1, RAD17 and RAD24 are required for normal meiotic recombination partner choice. Genetics 1999; 153:607-20. [PMID: 10511543 PMCID: PMC1460798 DOI: 10.1093/genetics/153.2.607] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Checkpoint gene function prevents meiotic progression when recombination is blocked by mutations in the recA homologue DMC1. Bypass of dmc1 arrest by mutation of the DNA damage checkpoint genes MEC1, RAD17, or RAD24 results in a dramatic loss of spore viability, suggesting that these genes play an important role in monitoring the progression of recombination. We show here that the role of mitotic checkpoint genes in meiosis is not limited to maintaining arrest in abnormal meioses; mec1-1, rad24, and rad17 single mutants have additional meiotic defects. All three mutants display Zip1 polycomplexes in two- to threefold more nuclei than observed in wild-type controls, suggesting that synapsis may be aberrant. Additionally, all three mutants exhibit elevated levels of ectopic recombination in a novel physical assay. rad17 mutants also alter the fraction of recombination events that are accompanied by an exchange of flanking markers. Crossovers are associated with up to 90% of recombination events for one pair of alleles in rad17, as compared with 65% in wild type. Meiotic progression is not required to allow ectopic recombination in rad17 mutants, as it still occurs at elevated levels in ndt80 mutants that arrest in prophase regardless of checkpoint signaling. These observations support the suggestion that MEC1, RAD17, and RAD24, in addition to their proposed monitoring function, act to promote normal meiotic recombination.
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Abstract
Eukaryotic checkpoint genes regulate multiple cellular responses to DNA damage. In this report, we examine the roles of budding yeast genes involved in G2/M arrest and tolerance to UV exposure. A current model posits three gene classes: those encoding proteins acting on damaged DNA (e.g. RAD9 and RAD24), those transducing a signal (MEC1, RAD53 and DUN1) or those participating more directly in arrest (PDS1). Here, we define important features of the pathways subserved by those genes. MEC1, which we find is required for both establishment and maintenance of G2/M arrest, mediates this arrest through two parallel pathways. One pathway requires RAD53 and DUN1 (the 'RAD53 pathway'); the other pathway requires PDS1. Each pathway independently contributes approximately 50% to G2/M arrest, effects demonstrable after cdc13-induced damage or a double-stranded break inflicted by the HO endonuclease. Similarly, both pathways contribute independently to tolerance of UV irradiation. How the parallel pathways might interact ultimately to achieve arrest is not yet understood, but we do provide evidence that neither the RAD53 nor the PDS1 pathway appears to maintain arrest by inhibiting adaptation. Instead, we think it likely that both pathways contribute to establishing and maintaining arrest.
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Abstract
Eukaryotic checkpoint controls impose delays in the cell cycle in response to DNA damage or defects in DNA replication. Genetic and physiological studies in budding yeast have identified key genes and defined genetic pathways involved in checkpoint-mediated responses. Recent studies now lead to biochemical models that explain at least in part the arrest in G1 and delays during DNA replication after damage. Though progress in checkpoint controls has indeed been rapid, several observations identify puzzling aspects of checkpoint controls with few plausible explanations.
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G2/M checkpoint genes of Saccharomyces cerevisiae: further evidence for roles in DNA replication and/or repair. MOLECULAR & GENERAL GENETICS : MGG 1997; 256:638-51. [PMID: 9435789 DOI: 10.1007/s004380050612] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We have cloned, sequenced and disrupted the checkpoint genes RAD17, RAD24 and MEC3 of Saccharomyces cerevisiae. Mec3p shows no strong similarity to other proteins currently in the database. Rad17p is similar to Rec1 from Ustilago maydis, a 3' to 5' DNA exonuclease/checkpoint protein, and the checkpoint protein Rad1p from Schizosaccharomyces pombe (as we previously reported). Rad24p shows sequence similarity to replication factor C (RFC) subunits, and the S. pombe Rad17p checkpoint protein, suggesting it has a role in DNA replication and/or repair. This hypothesis is supported by our genetic experiments which show that overexpression of RAD24 strongly reduces the growth rate of yeast strains that are defective in the DNA replication/repair proteins Rfc1p (cdc44), DNA pol alpha (cdc17) and DNA pol delta (cdc2) but has much weaker effects on cdc6, cdc9, cdc15 and CDC4 strains. The idea that RAD24 overexpression induces DNA damage, perhaps by interfering with replication/repair complexes, is further supported by our observation that RAD24 overexpression increases mitotic chromosome recombination in CDC4 strains. Although RAD17, RAD24 and MEC3 are not required for cell cycle arrest when S phase is inhibited by hydroxyurea (HU), they do contribute to the viability of yeast cells grown in the presence of HU, possibly because they are required for the repair of HU-induced DNA damage. In addition, all three are required for the rapid death of cdc13 rad9 mutants. All our data are consistent with models in which RAD17, RAD24 and MEC3 are coordinately required for the activity of one or more DNA repair pathways that link DNA damage to cell cycle arrest.
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Yeast checkpoint controls and relevance to cancer. CANCER SURVEYS 1997; 29:109-32. [PMID: 9338099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Checkpoint controls arrest cells with defects in DNA replication or DNA damage. For several reasons, checkpoint controls may be relevant to ontogeny and treatment of cancer. Firstly, mutations in two human genes, TP53 and ATM, give rise to cellular defects in cell cycle checkpoints and are associated with cancer. Secondly, although checkpoint defects potentially render the cell damage sensitive, they may do so only in combination with other defects in the cell's response to damage. Therefore, manipulation of checkpoint defects, requiring a description of normal and mutant pathways, will be required for this type of therapeutic approach. Those pathways are being described in yeast cells. In budding yeast, the study of checkpoint genes has led to the view that these genes have many roles in the cellular responses to DNA damage, including roles in arrest in multiple stages of cell cycle, in transcriptional induction of repair genes, in DNA repair itself and additionally some undefined role in DNA replication. The checkpoint pathways and proteins that carry out these responses may consist of sensor proteins that detect damage, signaller proteins that transduce an inhibitory signal and target proteins that are altered to arrest cell division (or cause other changes in cell behaviour). Yeast genes that may act at each step have been identified, leading to a working model of checkpoint pathways. An initial step in the pathway may involve the processing of damage to an intermediate that signals arrest and acts in DNA repair. Human checkpoint pathways may have defects in processing damage as well.
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Use of cdc13-1-induced DNA damage to study effects of checkpoint genes on DNA damage processing. Methods Enzymol 1997; 283:410-24. [PMID: 9251038 DOI: 10.1016/s0076-6879(97)83034-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Abstract
In budding yeast, meiotic recombination occurs at about 200 sites per cell and involves DNA double-strand break (DSB) intermediates. Here we provide evidence that a checkpoint control requiring the mitotic DNA-damage checkpoint genes RAD17, RAD24 and MEC1 ensures that meiotic recombination is complete before the first meiotic division (MI). First, RAD17, RAD24 and MEC1 are required for the meiotic arrest caused by blocking the repair of DSBs with a mutation in the recA homologue DMC1. Second, mec1 and rad24 single mutants (DMC1+) appear to undergo MI before all recombination events are complete. Curiously, the mitosis-specific checkpoint gene RAD9 is not required for meiotic arrest of dmc1 mutants. This shows that although mitotic and meiotic control mechanisms are related, they differ significantly. Rad17 and Rad24 proteins may contribute directly to formation of an arrest signal by association with single-strand DNA in mitosis and meiosis.
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Abstract
Eukaryotic checkpoint control genes are important for cell cycle delay, DNA repair and cell suicide after DNA is damaged. Recent studies in budding yeast show how the participation of checkpoint control proteins in DNA metabolism could lead to all three of these outcomes.
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Abstract
Yeast checkpoint control genes were found to affect processing of DNA damage as well as cell cycle arrest. An assay that measures DNA damage processing in vivo showed that the checkpoint genes RAD17, RAD24, and MEC3 activated an exonuclease that degrades DNA. The degradation is probably a direct consequence of checkpoint protein function, because RAD17 encodes a putative 3'-5' DNA exonuclease. Another checkpoint gene, RAD9, had a different role: It inhibited the degradation by RAD17, RAD24, and MEC3. A model of how processing of DNA damage may be linked to both DNA repair and cell cycle arrest is proposed.
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Cell cycle checkpoints, genomic integrity, and cancer. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 1994; 59:259-63. [PMID: 7587077 DOI: 10.1101/sqb.1994.059.01.030] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Cell cycle checkpoints, genetic instability and cancer. Semin Cancer Biol 1993; 4:129-40. [PMID: 8513148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
During the cell cycle, the order of events is maintained by controls termed checkpoints. Two checkpoints are sensitive to DNA damage, one that acts before mitosis and a second that acts before DNA replication. This is relevant to cancer because checkpoint mutants show genetic instability, and such instability is characteristic of many cancers. Studies of checkpoints in normal and cancer cells suggest a mechanistic relationship to the central cell cycle control p34CDC2 and its regulators. We suggest how mutations in these genes and those with a role in DNA metabolism may affect the function of checkpoints. A further link between checkpoints and cancer may be the p53 protein, which appears to function at the G1-S checkpoint. Consideration of checkpoints may provide more effective means for cancer treatment.
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Fidelity of mitotic chromosome transmission. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 1991; 56:359-65. [PMID: 1819497 DOI: 10.1101/sqb.1991.056.01.043] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Abstract
In response to DNA damage, Saccharomyces cerevisiae cells arrest the cell cycle in the G2 phase. Arrest is defective in rad9 mutants; rad9 cells divide and die without repairing the damage. Several cell cycle mutants that are defective in DNA replication arrest in G2 at the restrictive temperature; this arrest is due to the RAD9 control function. Thus RAD9 is responsible for the fact that mitosis is normally dependent upon DNA replication, a function we term a 'checkpoint'. Four additional genes have been identified that are also components of the RAD9 checkpoint.
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Abstract
A novel potent protein factor capable of inhibiting the in vitro polymerization of mammalian brain microtubule protein and of breaking down preformed microtubules has been partially purified from cell extracts of Dictyostelium discoideum. The factor has an apparent Mr of around 13000 and is trypsin resistant but heat and pepsin sensitive. When soluble microtubule protein was fractionated into tubulin and microtubule-associated proteins and each fraction was assayed independently for its susceptibility toward inhibition, it was clearly demonstrated that the tubulin but not the associated protein fraction was rendered nonpolymerizable. Soluble tubulin was inactivated at ratios of 1 mol of inhibitor to 100 mol of tubulin, estimated conservatively. Quantitative separation of tubulin and inhibitor after inactivation did not result in reactivation of tubulin's polymerizing capacity, suggesting a catalytic modification. The biochemical properties tested of the inactive tubulin argue against a mechanism involving simple proteolysis, N-site GTP hydrolysis or release, or general denaturation.
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[The highest age among peoples of all continents according to material from the Human Relations Area Files]. ZEITSCHRIFT FUR ETHNOLOGIE 1981; 106:51-91. [PMID: 12312568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
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