ARP/wARP and molecular replacement: the next generation

A systematic test shows how ARP/wARP deals with automated model building for structures that have been solved by molecular replacement. A description of protocols in the flex-wARP control system and studies of two specific cases are also presented

Levenswaardering bij ouderen (LWO): de validering van een meetinstrument

De doelstelling van dit onderzoek is de aanpassing en validering van een door Lawton en collega’s ontwikkelde schaal “Valuation of Life”, door ons vertaald als Levenswaardering. Lawton et al. ontwikkelden deze schaal om te laten zien dat naast de gezondheidsgerelateerde kwaliteit-van-leven (GKvL) er een andere kwaliteitsdimensie is die inzicht kan verschaffen in de subjectieve gezondheidsutiliteit op latere leeftijd, waaronder opvattingen over de gewenste levensduur en/of over levensverlenging en –beëindiging. Na een geautoriseerde vertaling is de schaal geïmplementeerd in de vierde waarneming van de LASA studie (2001-2002). In totaal hebben 1139 respondenten van 65-95 jaar de schaal ingevuld. Uitgebreide structuuranalyses leidden tot de conclusie dat de oorspronkelijke 19-item schaal tot een schaal van Levenswaarderingbij- Ouderen van 12 items kan worden gereduceerd, welke op te delen valt in drie subschalen: Veerkracht, Ambitie en Levenslust. Er blijkt nauwelijks overlap te zijn met de GKvL terwijl de overlap met min of meer objectieve gezondheidsmaten (discriminante validiteit) beperkt blijft. Er blijkt wel een verwantschap met de zg. positieve zelfbelevingsmaten (concurrente validiteit). We concluderen dan ook dat de LWO-schaal de waardering meet die iemand aan het leven hecht, waarbij er in de schaal-items geen enkele expliciete verwijzing is naar gezondheidsaspecten. De uiteindelijke toets voor het belang van de LWO-schaal zal moeten blijken in de onafhankelijke voorspellende kracht van de gezondheidsutiliteit die in een volgend artikel nader onderzocht gaat worden

HSF2BP negatively regulates homologous recombination in DNA interstrand crosslink repair

The tumor suppressor BRCA2 is essential for homologous recombination (HR), replication fork stability and DNA interstrand crosslink (ICL) repair in vertebrates. We show that ectopic production of HSF2BP, a BRCA2-interacting protein required for meiotic HR during mouse spermatogenesis, in non-germline human cells acutely sensitize them to ICL-inducing agents (mitomycin C and cisplatin) and PARP inhibitors, resulting in a phenotype characteristic of cells from Fanconi anemia (FA) patients. We biochemically recapitulate the suppression of ICL repair and establish that excess HSF2BP compromises HR by triggering the removal of BRCA2 from the ICL site and thereby preventing the loading of RAD51. This establishes ectopic expression of a wild-type meiotic protein in the absence of any other protein-coding mutations as a new mechanism that can lead to an FA-like cellular phenotype. Naturally occurring elevated production of HSF2BP in tumors may be a source of cancer-promoting genomic instability and also a targetable vulnerability

Development of FRET Assay into Quantitative and High-throughput Screening Technology Platforms for Protein–Protein Interactions

Förster resonance energy transfer (FRET) technology has been widely used in biological and biomedical research and is a very powerful tool in elucidating protein interactions in many cellular processes. Ubiquitination and SUMOylation are multi-step cascade reactions, involving multiple enzymes and protein–protein interactions. Here we report the development of dissociation constant (Kd) determination for protein–protein interaction and cell-based high-throughput screening (HTS) assay in SUMOylation cascade using FRET technology. These developments are based on steady state and high efficiency of fluorescent energy transfer between CyPet and YPet fused with SUMO1 and Ubc9, respectively. The developments in theoretical and experimental procedures for protein interaction Kd determination and cell-based HTS provide novel tools in affinity measurement and protein interaction inhibitor screening. The Kd determined by FRET between SUMO1 and Ubc9 is compatible with those determined with other traditional approaches, such as isothermal titration calorimetry (ITC) and surface plasmon resonance (SPR). The FRET-based HTS is pioneer in cell-based HTS. Both Kd determination and cell-based HTS, carried out in 384-well plate format, provide powerful tools for large-scale and high-throughput applications

Measuring older adults' filial responsibility expectations: exploring the application of a vignette technique and an item scale

This study focused on two conceptually distinct measures of the filial responsibility expectations of older adults: a vignette technique and an attitude item scale. Data were based on 1,553 respondents aged 61 to 92 years who participated in the Longitudinal Aging Study Amsterdam in 1998 to 1999. The results showed that the item scale had multiple dimensions of filial expectations. Older adults distinguished between emotional-, instrumental-, contact-, and information-oriented expectations. The vignette technique resulted in a unidimensional measurement of expectations. The intercorrelation between the scores of the item scale and vignette technique was modest, indicating a certain amount of overlap. Child characteristics incorporated into the vignettes added to the specificity of measurements of the filial expectations. The authors observed that older adults were more likely to have expectations for care from an adult child who is not employed and does not have children. Minor differences between sons and daughters were observed. © 2005 Sage Publications

Acculturation and use of health care services by Turkish and Moroccan migrants: a cross-sectional population-based study

<p>Abstract</p> <p>Background</p> <p>There is insufficient empirical evidence which shows if and how there is an interrelation between acculturation and health care utilisation. The present study seeks to establish this evidence within first generation Turkish and Moroccan migrants, two of the largest migrant groups in present-day Western Europe.</p> <p>Methods</p> <p>Data were derived from the Amsterdam Health Monitor 2004, and were complete for 358 Turkish and 288 Moroccan foreign-born migrants. Use of health services (general practitioner, outpatient specialist and health care for mental health problems) was measured by means of self-report. Acculturation was measured by a structured questionnaire grading (i) ethnic self-identification, (ii) social interaction with ethnic Dutch, (iii) communication in Dutch within one's private social network, (iv) emancipation, and (v) cultural orientation towards the public domain.</p> <p>Results</p> <p>Acculturation was hardly associated with the use of general practitioner care. However, in case of higher adaptation to the host culture there was less uptake of outpatient specialist care among Turkish respondents (odds ratio [OR] = 0.90, 95% confidence interval [CI] = 0.82-0.99) and Moroccan male respondents (OR = 0.81, 95% CI = 0.71-0.93). Conversely, there was a higher uptake of mental health care among Turkish men (OR = 0.81, 95% CI = 0.71-0.93) and women (OR = 0.81, 95% CI = 0.71-0.93). Uptake of mental health care among Moroccan respondents again appeared lower (OR = 0.74, 95% CI = 0.55-0.99). Language ability appeared to play a central role in the uptake of health care.</p> <p>Conclusion</p> <p>Some results were in accordance with the popular view that an increased participation in the host society is concomitant to an increased use of health services. However, there was heterogeneity across ethnic and gender groups, and across the domains of acculturation. Language ability appeared to play a central role. Further research needs to explore this heterogeneity into more detail. Also, other cultural and/or contextual aspects that influence the use of health services require further identification.</p

Promotion of self-management in vulnerable older people: a narrative literature review of outcomes of the Chronic Disease Self-Management Program (CDSMP)

With ageing, older people can become frail, and this has been shown to be associated with a decrease in well-being. Observational studies provide evidence of a positive effect of coping resources on well-being. The question is: can coping resources be improved in vulnerable older people? The Chronic Disease Self-Management Program (CDSMP) is a target group-specific intervention which aims to promote the self-management of older people who are confronted with deteriorating health. The aim of this study was to review intervention studies focusing on the CDSMP and to draw conclusions on the benefits of the program. A systematic search was conducted in PubMed and PsychINFO to identify randomized controlled trials (RCTs) focusing on the CDSMP. Nine RCTs focusing on relatively young older adults, 75% of whom with an average age between 49 and 65 years, were included. We found that the CDSMP was consistently beneficial for Health behaviour, especially with regard to the variables of exercise and self-care. For Health status, the majority of studies only showed improvement in the domain of health distress. Most of the studies that investigated Self-efficacy showed convincing improvement in self-efficacy, cognitive symptom management and mental stress management. In Health care utilization, there was no significant decrease. On the whole, the studies showed that CDSMP led to an increase in physical exercise, a decrease in health distress, an improvement in self-care, and it had a beneficial effect on self-efficacy

An Eight-Week Trial Investigating the Efficacy and Tolerability of Atorvastatin for Children and Adolescents With Heterozygous Familial Hypercholesterolemia

This study aimed to assess the efficacy and tolerability of atorvastatin in Tanner stage (TS) 1 patients ages 6 to 10 years and TS ≥2 patients ages 10 to <18 years with genetically confirmed heterozygous familial hypercholesterolemia (HeFH) and a low density lipoprotein cholesterol (LDL-C) level of 4 mmol/l (155 mg/dl) or higher. In this open-label, 8-week study, 15 TS 1 children were treated initially with atorvastatin 5 mg/day and 24 TS ≥2 children with 10 mg/day. Doses were doubled at week 4 if the LDL-C target (<3.35 mmol/l [130 mg/dl]) was not achieved. The efficacy variables were the percentage change from baseline in LDL-C, total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL-C), very low density lipoprotein cholesterol (VLDL-C), and apolipoprotein (Apo) A-I and Apo B. Safety evaluations included clinical monitoring, subject-reported adverse events (AEs), vital signs, and clinical laboratory tests. The mean values for LDL-C, TC, VLDL-C, and Apo B decreased by week 2 among all TS 1 and TS ≥2 patients, whereas TG, HDL-C, and Apo A-I varied considerably from week to week. After 8 weeks, the mean reduction in LDL-C was −40.7% ± 8.4 for the TS 1 children and −39.7% ± 10.3 for the TS ≥2 children. For the TS 1 patients, the mean reductions were −34.1% ± 6.9 for TC and −6.0% ± 32.1 for TG. The corresponding changes for the TS ≥2 patients were −35.6% ± 9.5 for TC and −21.1% ± 29.7 for TG. Four patients experienced mild to moderate treatment-related AEs. No serious AEs or discontinuations were reported. Overall, no difference in safety or tolerability was observed between the younger and older cohorts. Across the range of exposures after atorvastatin 5 to 10 mg (TS 1) or atorvastatin 10 to 20 mg (TS ≥2) doses for 8 weeks, clinically meaningful reductions in LDL-C, TC, VLDL-C, and Apo were observed with atorvastatin in pediatric patients who had HeFH. Atorvastatin also was well tolerated in this population

The Fanconi Anemia Core Complex Is Dispensable during Somatic Hypermutation and Class Switch Recombination

To generate high affinity antibodies during an immune response, B cells undergo somatic hypermutation (SHM) of their immunoglobulin genes. Error-prone translesion synthesis (TLS) DNA polymerases have been reported to be responsible for all mutations at template A/T and at least a fraction of G/C transversions. In contrast to A/T mutations which depend on PCNA ubiquitination, it remains unclear how G/C transversions are regulated during SHM. Several lines of evidence indicate a mechanistic link between the Fanconi Anemia (FA) pathway and TLS. To investigate the contribution of the FA pathway in SHM we analyzed FancG-deficient B cells. B cells deficient for FancG, an essential member of the FA core complex, were hypersensitive to treatment with cross-linking agents. However, the frequencies and nucleotide exchange spectra of SHM remained comparable between wild-type and FancG-deficient B cells. These data indicate that the FA pathway is not involved in regulating the outcome of SHM in mammals. In addition, the FA pathway appears dispensable for class switch recombination

Phosphorylation of Ubc9 by Cdk1 Enhances SUMOylation Activity

Increasing evidence has pointed to an important role of SUMOylation in cell cycle regulation, especially for M phase. In the current studies, we have obtained evidence through in vitro studies that the master M phase regulator CDK1/cyclin B kinase phosphorylates the SUMOylation machinery component Ubc9, leading to its enhanced SUMOylation activity. First, we show that CDK1/cyclin B, but not many other cell cycle kinases such as CDK2/cyclin E, ERK1, ERK2, PKA and JNK2/SAPK1, specifically enhances SUMOylation activity. Second, CDK1/cyclin B phosphorylates the SUMOylation machinery component Ubc9, but not SAE1/SAE2 or SUMO1. Third, CDK1/cyclin B-phosphorylated Ubc9 exhibits increased SUMOylation activity and elevated accumulation of the Ubc9-SUMO1 thioester conjugate. Fourth, CDK1/cyclin B enhances SUMOylation activity through phosphorylation of Ubc9 at serine 71. These studies demonstrate for the first time that the cell cycle-specific kinase CDK1/cyclin B phosphorylates a SUMOylation machinery component to increase its overall SUMOylation activity, suggesting that SUMOylation is part of the cell cycle program orchestrated by CDK1 through Ubc9