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1.
Int J Qual Health Care ; 30(5): 396-407, 2018 Jun 01.
Article in English | MEDLINE | ID: mdl-29590365

ABSTRACT

QUALITY PROBLEM OR ISSUE: A patient survey found significantly fewer patients reported they had self-administered their medicines while in hospital (20% of 100 patients) than reported that they would like to (44% of 100). We aimed to make self-administration more easily available to patients who wanted it. INITIAL ASSESSMENT: We conducted a failure, modes and effects analysis, collected baseline data on four wards and carried out observations. CHOICE OF SOLUTION: Our initial assessment suggested that the main areas we should focus on were raising patient awareness of self-administration, changing the patient assessment process and creating a storage solution for medicines being self-administered. We developed new patient information leaflets and posters and a doctor's assessment form using Plan-Do-Study-Act cycles. We developed initial designs for a storage solution. IMPLEMENTATION: We piloted the new materials on three wards; the fourth withdrew due to staff shortages. EVALUATION: Following collection of baseline data, we continued to collect weekly data. We found that the proportion of patients who wished to self-administer who reported that they were able to do so, significantly increased from 41% (of 155 patients) to 66% (of 118 patients) during the study, despite a period when the hospital was over capacity. LESSONS LEARNED: Raising and maintaining healthcare professionals' awareness of self-administration can greatly increase the proportion of patients who wish to self-administer who actually do so. Healthcare professionals prefer multi-disciplinary input into the assessment process.


Subject(s)
Patient Participation/statistics & numerical data , Quality Improvement/organization & administration , Self Administration/methods , Health Knowledge, Attitudes, Practice , Hospitals, Teaching , Humans , London , Pamphlets , Posters as Topic , Self Administration/statistics & numerical data , Surveys and Questionnaires
2.
Res Involv Engagem ; 2: 29, 2016.
Article in English | MEDLINE | ID: mdl-29507764

ABSTRACT

PLAIN ENGLISH SUMMARY: There is a consensus that patients and the public should be involved in research in a meaningful way. However, to date, lay people have been mostly involved in developing research ideas and commenting on patient information.We previously published a paper describing our experience with lay partners conducting observations in a study of how patients in hospital are involved with their medicines. In a later part of the same study, lay partners were also involved in analysing interviews that a researcher had conducted with patients, carers and healthcare professionals about patient and carer involvement with medicines in hospital. We therefore wanted to build on our previous paper and report on our experiences with lay partners helping to conduct data analysis. We therefore interviewed the lay members and researchers involved in the analysis to find out their views.Both lay members and researchers reported that lay partners added value to the study by bringing their own perspectives and identifying further areas for the researcher to look for in the interviews. In this way researchers and lay partners were able to work together to produce a richer analysis than would have been possible from either alone. ABSTRACT: Background It is recognised that involving lay people in research in a meaningful rather than tokenistic way is both important and challenging. In this paper, we contribute to this debate by describing our experiences of lay involvement in data analysis.Methods We conducted semi-structured interviews with the lay partners and researchers involved in qualitative data analysis in a wider study of inpatient involvement in medication safety. The interviews were transcribed verbatim and coded using open thematic analysis.Results We interviewed three lay partners and the three researchers involved. These interviews demonstrated that the lay members added value to the analysis by bringing their own perspectives; these were systematically integrated into the analysis by the lead researcher to create a synergistic output. Some challenges arose, including difficulties in recruiting a diverse range of members of the public to carry out the role; however there were generally fewer challenges in data analysis than there had been with our previous experience of lay partners' involvement in data collection.Conclusions Lay members can add value to health services research by being involved in qualitative data analysis.

6.
Transplant Proc ; 41(9): 3531-6, 2009 Nov.
Article in English | MEDLINE | ID: mdl-19917339

ABSTRACT

INTRODUCTION: The European Machine Preservation Trial (MPT) found a significantly lower rate of delayed graft function and improved graft survival in machine-perfused kidneys compared to cold-stored kidneys in the first year following kidney transplantation. Little is known about the cost-effectiveness of various organ preservation methods. METHODS: Outcome data from the MPT have been used to conduct a comparative cost-effectiveness analysis based on preservation method for both standard criteria (SCD) and expanded criteria donor (ECD) kidney transplants in the United States. Using graft survival as the primary outcome measure, a cost-effectiveness model was developed using Medicare and private payer cost/payment data, as well as clinical transition probabilities based on the MPT and other studies. RESULTS: At 1-year posttransplant, machine perfusion is a more cost-effective option than cold storage for organ preservation in transplants involving either SCD ($92,561 vs $104,118) or ECD ($106,012 vs $114,530) kidneys. Moreover, the cost-effectiveness ratios for transplants involving machine-perfused ECD kidneys ($106,012) are similar to those for transplants using cold-stored SCD kidneys ($104,118). CONCLUSION: Machine perfusion is preferable to cold storage for organ preservation in both SCD and ECD donor kidney transplants. Not only is it more cost-effective, but from all relevant perspectives it adds substantial value.


Subject(s)
Kidney Transplantation/economics , Organ Preservation/economics , Cost-Benefit Analysis , Graft Survival , Humans , Organ Preservation/instrumentation , Organ Preservation/methods , Postoperative Complications/economics , Probability , Renal Replacement Therapy/economics , Tissue Donors/statistics & numerical data , Treatment Outcome , United States
7.
Qual Saf Health Care ; 18(5): 341-6, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19812095

ABSTRACT

INTRODUCTION: Care home residents are at particular risk from medication errors, and our objective was to determine the prevalence and potential harm of prescribing, monitoring, dispensing and administration errors in UK care homes, and to identify their causes. METHODS: A prospective study of a random sample of residents within a purposive sample of homes in three areas. Errors were identified by patient interview, note review, observation of practice and examination of dispensed items. Causes were understood by observation and from theoretically framed interviews with home staff, doctors and pharmacists. Potential harm from errors was assessed by expert judgement. RESULTS: The 256 residents recruited in 55 homes were taking a mean of 8.0 medicines. One hundred and seventy-eight (69.5%) of residents had one or more errors. The mean number per resident was 1.9 errors. The mean potential harm from prescribing, monitoring, administration and dispensing errors was 2.6, 3.7, 2.1 and 2.0 (0 = no harm, 10 = death), respectively. Contributing factors from the 89 interviews included doctors who were not accessible, did not know the residents and lacked information in homes when prescribing; home staff's high workload, lack of medicines training and drug round interruptions; lack of team work among home, practice and pharmacy; inefficient ordering systems; inaccurate medicine records and prevalence of verbal communication; and difficult to fill (and check) medication administration systems. CONCLUSIONS: That two thirds of residents were exposed to one or more medication errors is of concern. The will to improve exists, but there is a lack of overall responsibility. Action is required from all concerned.


Subject(s)
Homes for the Aged/statistics & numerical data , Medication Errors/statistics & numerical data , Nursing Homes/statistics & numerical data , Aged , Aged, 80 and over , Anthropology, Cultural , Female , Humans , Interviews as Topic , Male , Medication Errors/adverse effects , Middle Aged , Prevalence , Prospective Studies , United Kingdom
8.
Patient Educ Couns ; 66(3): 361-7, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17331691

ABSTRACT

OBJECTIVE: The current study aimed to develop a model of patients' preferences for involvement in decision-making concerning the use of medicines for chronic conditions in the UK and test it in a large representative sample of patients with one of two clinical conditions. METHODS: Following a structured literature review, an instrument was developed which measured the variables that had been identified as predictors of patients' preferences for involvement in decision making in previous research. Five hundred and sixteen patients with rheumatoid arthritis or type 2 diabetes were recruited from outpatient and primary care clinics and asked to complete the instrument. RESULTS: Multivariate analysis revealed that age, social class and clinical condition were associated with preferences for involvement in decision-making concerning the use of medicines for chronic illness but gender, ethnic group, concerns about medicines, beliefs about necessity of medicines, health status, quality of life and time since diagnosis were not. In total, the fitted model explained only 14% of the variance. CONCLUSION: This study has demonstrated that current research does not provide a basis for predicting patients' preferences for involvement in decision-making. PRACTICE IMPLICATIONS: Building concordant relationships may depend on practitioners developing strategies to establish individuals' preferences for involvement in decision-making as part of the ongoing prescriber-patient relationship.


Subject(s)
Decision Making , Drug Therapy/psychology , Models, Psychological , Patient Participation/psychology , Physician-Patient Relations , Adult , Aged , Aged, 80 and over , Arthritis, Rheumatoid/drug therapy , Arthritis, Rheumatoid/psychology , Chronic Disease/psychology , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/psychology , Factor Analysis, Statistical , Female , Health Status , Humans , Male , Middle Aged , Multivariate Analysis , Patient Satisfaction , Predictive Value of Tests , Quality of Life , Severity of Illness Index , Socioeconomic Factors , Surveys and Questionnaires , United Kingdom
9.
J Clin Pathol ; 58(11): 1206-10, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16254113

ABSTRACT

BACKGROUND: Although nucleic acid derangements are the hallmark of melanocytic dysplasia, the gold standard for its diagnosis remains the microscopic evaluation of haematoxylin and eosin stained slides. However, light microscopy is subjective and crucial genomic changes do not always show as changes in histology. AIMS: To introduce the nucleic acid index (NAI) as a means of analysing nucleic acid derangements in histological sections at the level of the individual cell and within the context of its microenvironment. METHODS: Confocal laser scanning microscopy was performed on melanocytic lesions stained with acridine orange (AO), a fluorescent stain for DNA and RNA. The NAI, calculated by measuring the fluorescence intensities of AO in nuclei relative to the surrounding cytoplasm, reflects the concentration of DNA relative to RNA. RESULTS: When applied to benign naevi, dysplastic naevi, and melanoma, a very strong significant association was seen between lower NAI and malignant potential (p < 0.0001). Strong inverse correlations were found between NAI and both mitotic index and Breslow thickness. Interestingly, the NAI for dysplastic naevi is between that of melanoma and most benign naevi, consistent with their intermediate biological behaviour and histological appearance. CONCLUSION: By providing a quantitative measure for melanocytic neoplasia, the NAI may improve the diagnosis of melanocytic lesions and the selection of treatment.


Subject(s)
DNA, Neoplasm/analysis , Dysplastic Nevus Syndrome/diagnosis , Melanoma/diagnosis , Skin Neoplasms/diagnosis , Diagnosis, Differential , Dysplastic Nevus Syndrome/genetics , Dysplastic Nevus Syndrome/pathology , Humans , Image Processing, Computer-Assisted/methods , Melanocytes/pathology , Melanoma/genetics , Melanoma/pathology , Microscopy, Confocal/methods , Mitotic Index , Nevus, Pigmented/diagnosis , Nevus, Pigmented/genetics , Nevus, Pigmented/pathology , Paraffin Embedding , RNA, Neoplasm/analysis , Skin Neoplasms/genetics , Skin Neoplasms/pathology
10.
Bioinformatics ; 21(15): 3248-54, 2005 Aug 01.
Article in English | MEDLINE | ID: mdl-15947019

ABSTRACT

MOTIVATION: Recent advances in confocal microscopy have allowed scientists to assess the expression, and to some extent, the interaction/colocalization of multiple molecules within cells and tissues. In some instances, accurately quantifying the colocalization of two or more proteins may be critical. This can require the acquisition of multiple Z plane images (Z stacks) throughout a specimen and, as such, we report here the successful development of a freeware, open-source image analysis tool, IMAJIN_COLOC, developed in PERL (v. 5.8, build 806), using the PERLMagick libraries (ImageMagick). Using a pixel-by-pixel analysis algorithm, IMAJIN_COLOC can analyze images for antigen expression (any number of colors) and can measure all possible combinations of colocalization for up to three colors by analyzing a Z stack gallery acquired for each sample. The simultaneous (i.e. in a single pass) analysis of three-color colocalization, and batch analysis capabilities are distinctive features of this program. RESULTS: A control image, containing known individual and colocalized pixel counts, was used to validate the accuracy of IMAJIN_COLOC. As further validation, pixel counts and colocalization values from the control image were compared to those obtained with the software packaged with the Zeiss laser-scanning microscope (LSM AIM, version 3.2). The values from both programs were found to be identical. To demonstrate the applicability of this program in addressing novel biological questions, we examined the role of neurons in eliciting an immune reaction in response to viral infection. Specifically, we successfully examined expression of the chemokine RANTES in measles virus (MV) infected hippocampal neurons and quantified changes in RANTES production throughout the disease period. The resultant quantitative data were also evaluated visually, using a gif image created during the analysis. AVAILABILITY: PERL (ActivePerl, version 5.8) is available at activestate.com; the PERLMagick libraries are available at imagemagick.org, and IMAJIN_COLOC, the source code and user documentation can be downloaded from http://www.fda.gov/cber/research/imaging/imageanalysis.htm.


Subject(s)
Algorithms , Chemokine CCL5/metabolism , Image Interpretation, Computer-Assisted/methods , Measles/metabolism , Microscopy, Confocal/methods , Neurons/metabolism , Protein Interaction Mapping/methods , Software , Animals , Hippocampus/metabolism , Hippocampus/pathology , Measles/pathology , Mice , Neurons/pathology
11.
Mol Cell Biol ; 24(9): 3972-82, 2004 May.
Article in English | MEDLINE | ID: mdl-15082790

ABSTRACT

To understand the mechanism of retinoid resistance, we studied the subcellular localization and function of retinoid receptors in human breast cancer cell lines. Retinoid X receptor alpha (RXR alpha) localized throughout the nucleoplasm in retinoid-sensitive normal human mammary epithelial cells and in retinoid-responsive breast cancer cell line (MCF-7), whereas it was found in the splicing factor compartment (SFC) of the retinoid-resistant MDA-MB-231 breast cancer cell line and in human breast carcinoma tissue. In MDA-MB-231 cells, RXR alpha was not associated with active transcription site in the presence of ligand. Similarly, ligand-dependent RXR homo- or heterodimer-mediated transactivation on RXR response element or RARE showed minimal response to ligand in MDA-MB-231 cells. Infecting MDA-MB-231 cells with adenoviral RXR alpha induced nucleoplasmic overexpression of RXR alpha and resulted in apoptosis upon treatment with an RXR ligand. This suggests that nucleoplasmic RXR alpha restores retinoid sensitivity. Epitope-tagged RXR alpha and a C-terminus deletion mutant failed to localize to the SFC. Moreover, RXR alpha localization to the SFC was inhibited with RXR alpha C-terminus peptide. This peptide also induced ligand-dependent transactivation on RXRE. Therefore, the RXR alpha C terminus may play a role in the intranuclear localization of RXR alpha. Our results provide evidence that altered localization of RXR alpha to the SFC may be an important factor for the loss of retinoid responsiveness in MDA-MB-231 breast cancer cells.


Subject(s)
Antineoplastic Agents/metabolism , Breast Neoplasms/metabolism , Drug Resistance, Neoplasm , Receptors, Retinoic Acid/metabolism , Retinoids/metabolism , Transcription Factors/metabolism , Adenoviridae/genetics , Adenoviridae/metabolism , Apoptosis , Breast Neoplasms/pathology , Cell Line, Tumor , Epithelial Cells/cytology , Epithelial Cells/metabolism , Female , Gene Expression Regulation , Humans , Ligands , Mammary Glands, Human/cytology , Mammary Glands, Human/pathology , Receptors, Retinoic Acid/genetics , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Retinoid X Receptors , Subcellular Fractions/metabolism , Transcription Factors/genetics , Transcription, Genetic
12.
Psychother Res ; 13(1): 128-30, 2003 Mar.
Article in English | MEDLINE | ID: mdl-22475171
13.
J Med Chem ; 44(23): 3872-80, 2001 Nov 08.
Article in English | MEDLINE | ID: mdl-11689073

ABSTRACT

Since 1990, the National Cancer Institute has performed extensive in vitro screening of compounds for anticancer activity. To date, more than 70 000 compounds have been screened for their antiproliferation activities against a panel of 60 human cancer cell lines. We probed this database to identify novel structural classes with a pattern of biological activity on these cell lines similar to that of the phorbol esters. The iridals form such a structural class. Using the program Autodock, we show that the iridals dock to the same position on the C1b domain of protein kinase C delta as do the phorbol esters, with the primary hydroxyl group of the iridal at the C3 position forming two hydrogen bonds with the amide group of Thr12 and with the carbonyl group of Leu 21 and the aldehyde oxygen of the iridal forming a hydrogen bond with the amide group of Gly23. Biological analysis of two iridals, NSC 631939 and NSC 631941, revealed that they bound to protein kinase C alpha with K(i) values of 75.6 +/- 1.3 and 83.6 +/- 1.5 nM, respectively. Protein kinase C is now recognized to represent only one of five families of proteins with C1 domains capable of high-affinity binding of diacylglycerol and the phorbol esters. NSC 631939 and NSC 631941 bound to RasGRP3, a phorbol ester receptor that directly links diacylglycerol/phorbol ester signaling with Ras activation, with K(i) values of 15.5 +/- 2.3 and 41.7 +/- 6.5 nM, respectively. Relative to phorbol 12,13-dibutyrate, they showed 15- and 6-fold selectivity for RasGRP3. Both compounds caused translocation of green fluorescent protein tagged RasGRP3 expressed in HEK293 cells, and both compounds induced phosphorylation of ERK1/2, a downstream indicator of Ras activation, in a RasGRP3-dependent fashion. We conclude that the iridals represent a promising structural motif for design of ligands for phorbol ester receptor family members.


Subject(s)
Acrolein/chemistry , Antineoplastic Agents, Phytogenic/chemistry , Caenorhabditis elegans Proteins , Cyclohexanols/chemistry , Diterpenes , Guanine Nucleotide Exchange Factors/metabolism , Iridaceae/chemistry , Phorbols/metabolism , Protein Kinase C/metabolism , Receptors, Drug/metabolism , Spiro Compounds/chemistry , Acrolein/analogs & derivatives , Acrolein/metabolism , Acrolein/pharmacology , Antineoplastic Agents, Phytogenic/metabolism , Antineoplastic Agents, Phytogenic/pharmacology , Binding, Competitive , Carrier Proteins , Cell Line , Crystallography, X-Ray , Cyclohexanols/metabolism , Cyclohexanols/pharmacology , Databases, Factual , Drug Screening Assays, Antitumor , Green Fluorescent Proteins , Guanine Nucleotide Exchange Factors/genetics , Humans , Isoenzymes/chemistry , Isoenzymes/metabolism , Ligands , Luminescent Proteins/genetics , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3 , Mitogen-Activated Protein Kinases/metabolism , Models, Molecular , Phosphorylation , Protein Kinase C/chemistry , Protein Kinase C-alpha , Protein Kinase C-delta , Radioligand Assay , Recombinant Fusion Proteins/metabolism , Spiro Compounds/metabolism , Spiro Compounds/pharmacology , Stereoisomerism , Terpenes/pharmacology , Tumor Cells, Cultured , ras Guanine Nucleotide Exchange Factors
14.
J Child Adolesc Psychopharmacol ; 11(3): 239-50, 2001.
Article in English | MEDLINE | ID: mdl-11642474

ABSTRACT

OBJECTIVE: The goal of this study was to assess the effectiveness and tolerability of olanzapine in the treatment of acute mania in children and adolescents. METHODS: This was an 8-week, open-label, prospective study of olanzapine monotherapy (dose range 2.5-20 mg/day) involving 23 bipolar youths (manic, mixed, or hypomanic; 5-14 years old). Weekly assessments were made using the Young Mania Rating Scale (YMRS), Clinical Global Impressions Severity Scale (CGI-S), Brief Psychiatric Rating Scale, and Children's Depression Rating Scale. Adverse events were assessed through self-reports, vital sign and weight monitoring, laboratory analytes, and extrapyramidal symptom rating scales (Barnes Akathisia Scale, Simpson-Angus Scale, and Abnormal Involuntary Movement Scale). RESULTS: Twenty-two of the 23 youths (96%) completed the study. Olanzapine treatment was associated with significant improvement in mean YMRS score (-19.0 +/- 9.2, p < 0.001). Using predefined criteria for improvement of > or = 30% decline in the YMRS and a CGI-S Mania score of < or = 3 at endpoint, the overall response rate was 61%. Overall, olanzapine was well tolerated, and extrapyramidal symptom measures were not significantly different from baseline. Body weight increased significantly over the study (5.0 +/- 2.3 kg, p < 0.001). CONCLUSIONS: Open-label olanzapine treatment was efficacious and well tolerated in the treatment of acute mania in youths with bipolar disorder. Future placebo-controlled, double-blind studies are warranted.


Subject(s)
Antipsychotic Agents/therapeutic use , Bipolar Disorder/drug therapy , Pirenzepine/analogs & derivatives , Pirenzepine/therapeutic use , Abdominal Pain/chemically induced , Adolescent , Antipsychotic Agents/adverse effects , Appetite/drug effects , Benzodiazepines , Brief Psychiatric Rating Scale , Child , Child, Preschool , Disorders of Excessive Somnolence/chemically induced , Female , Humans , Male , Olanzapine , Patient Compliance , Pirenzepine/adverse effects , Prospective Studies , Severity of Illness Index , Time Factors , Weight Gain/drug effects
15.
J Biol Chem ; 276(42): 38795-807, 2001 Oct 19.
Article in English | MEDLINE | ID: mdl-11489895

ABSTRACT

Human tumor endothelial marker 1/endosialin (TEM1/endosialin) was recently identified as a novel tumor endothelial cell surface marker potentially involved in angiogenesis, although no specific function for this novel gene has been assigned so far. It was reported to be expressed in tumor endothelium but not in normal endothelium with the exception of perhaps the corpus luteum. Here we describe the cDNA and genomic sequences for the mouse Tem1/endosialin homolog, the identification and characterization of its promoter region, and an extensive characterization of its expression pattern in murine and human tissues and murine cell lines in vitro. The single copy gene that was mapped to chromosome 19 is intronless and encodes a 92-kDa protein that has 77.5% overall homology to the human protein. The remarkable findings are 1) this gene is ubiquitously expressed in normal human and mouse somatic tissues and during development, and 2) its expression at the mRNA level is density-dependent and up-regulated in serum-starved cells. In vitro, its expression is limited to cells of embryonic, endothelial, and preadipocyte origin, suggesting that the wide distribution of its expression in vivo is due to the presence of vascular endothelial cells in all the tissues. The ubiquitous expression in vivo is in contrast to previously reported expression limited to corpus luteum and highly angiogenic tissues such as tumors and wound tissue.


Subject(s)
Membrane Proteins/biosynthesis , Membrane Proteins/genetics , Neoplasm Proteins/biosynthesis , Neoplasm Proteins/genetics , 3T3 Cells , Amino Acid Sequence , Animals , Antigens, CD , Antigens, Neoplasm , Base Sequence , Blotting, Northern , Blotting, Southern , Blotting, Western , Cell Division , Cell Line , Cells, Cultured , Chromosome Mapping , Chromosomes, Human, Pair 19 , Corpus Luteum/metabolism , Crosses, Genetic , DNA, Complementary/metabolism , Endothelium, Vascular/cytology , Female , Gene Library , Humans , Immunohistochemistry , In Situ Hybridization , Introns , Luciferases/metabolism , Mice , Mice, Inbred C57BL , Microscopy, Confocal , Microscopy, Fluorescence , Models, Genetic , Molecular Sequence Data , Promoter Regions, Genetic , Protein Binding , Reverse Transcriptase Polymerase Chain Reaction , Tissue Distribution , Transcription, Genetic , Up-Regulation
16.
Mol Cell Biol ; 21(15): 5169-78, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11438671

ABSTRACT

Condensation of the chromatin fiber and transcriptional inhibition during mitosis is associated with the redistribution of many DNA- and chromatin-binding proteins, including members of the high-mobility-group N (HMGN) family. Here we study the mechanism governing the organization of HMGN proteins in mitosis. Using site-specific antibodies and quantitative gel analysis with proteins extracted from synchronized HeLa cells, we demonstrate that, during mitosis, the conserved serine residues in the nucleosomal binding domain (NBD) of this protein family are highly and specifically phosphorylated. Nucleosome mobility shift assays with both in vitro-phosphorylated proteins and with point mutants bearing negative charges in the NBD demonstrate that the negative charge abolishes the ability of the proteins to bind to nucleosomes. Fluorescence loss of photobleaching demonstrates that, in living cells, the negative charge in the NBD increases the intranuclear mobility of the protein and significantly decreases the relative time that it is bound to chromatin. Expression of wild-type and mutant proteins in HmgN1(-/-) cells indicates that the negatively charged protein is not bound to chromosomes. We conclude that during mitosis the NBD of HMGN proteins is highly phosphorylated and that this modification regulates the interaction of the proteins with chromatin.


Subject(s)
Chromatin/metabolism , Mitosis , Blotting, Western , Cell Cycle , Chromosomes/metabolism , Electrophoresis, Polyacrylamide Gel , Fibroblasts/metabolism , Flow Cytometry , HeLa Cells , Humans , Microscopy, Confocal , Microscopy, Fluorescence , Models, Genetic , Mutation , Nucleosomes/metabolism , Phosphorylation , Protein Binding , Protein Structure, Tertiary , Recombinant Proteins/metabolism , Time Factors , Transcription, Genetic , Transfection
17.
J Med Chem ; 44(12): 1892-904, 2001 Jun 07.
Article in English | MEDLINE | ID: mdl-11384235

ABSTRACT

A small, focused combinatorial library encompassing all possible permutations of acyl branched alkyl chains-small and large, saturated and unsaturated-was generated from the active diacylglycerol enantiomer (S-DAG) to help identify the analogue with the highest binding affinity (lowest Ki) for protein kinase C (PK-C) combined with the minimum lipophilicity (log P). The selected ligand (3B) activated PK-C more effectively than sn-1,2-dioctanoylglycerol (diC8) despite being 1.4 log units more hydrophilic. Compound 3B indeed represents the most potent, hydrophilic DAG ligand to date. With the help of a green fluorescent protein (GFP)-tagged PK-Calpha, 3B was able to translocate the full length protein to the membrane with an optimal dose of 100 microM in CHO-K1 cells, while diC8 failed to achieve translocation even at doses 3-fold higher. Molecular modeling of 3B into an empty C1b domain of PK-Cdelta clearly showed the existence of a preferred binding orientation. In addition, molecular dynamic simulations suggest that binding discrimination could result from a favorable van der Waals (VDW) interaction between the large, branched sn-1 acyl group of 3B and the aromatic rings of Trp252 (PK-Cdelta) or Tyr252 (PK-Calpha). The DAG analogue of 3B in which the acyl groups are reversed (2C) showed a decrease in binding affinity reflecting the capacity of PK-C to effectively discriminate between alternative orientations of the acyl chains.


Subject(s)
Diglycerides/chemistry , Diglycerides/pharmacology , Protein Kinase C/chemistry , Protein Kinase C/metabolism , Animals , Binding Sites , Binding, Competitive , CHO Cells , Cricetinae , Databases as Topic , Diglycerides/chemical synthesis , Enzyme Activation , Hydrogen Bonding , Kinetics , Models, Molecular , Molecular Conformation , Phorbol 12,13-Dibutyrate/pharmacokinetics , Protein Conformation , Protein Structure, Secondary , Recombinant Fusion Proteins/chemistry , Recombinant Fusion Proteins/metabolism , Structure-Activity Relationship , Transfection , Tryptophan , Tyrosine , Zinc Fingers
18.
J Biol Chem ; 276(35): 32948-55, 2001 Aug 31.
Article in English | MEDLINE | ID: mdl-11399766

ABSTRACT

The Bloom syndrome (BS) protein, BLM, is a member of the RecQ DNA helicase family that also includes the Werner syndrome protein, WRN. Inherited mutations in these proteins are associated with cancer predisposition of these patients. We recently discovered that cells from Werner syndrome patients displayed a deficiency in p53-mediated apoptosis and WRN binds to p53. Here, we report that analogous to WRN, BLM also binds to p53 in vivo and in vitro, and the C-terminal domain of p53 is responsible for the interaction. p53-mediated apoptosis is defective in BS fibroblasts and can be rescued by expression of the normal BLM gene. Moreover, lymphoblastoid cell lines (LCLs) derived from BS donors are resistant to both gamma-radiation and doxorubicin-induced cell killing, and sensitivity can be restored by the stable expression of normal BLM. In contrast, BS cells have a normal Fas-mediated apoptosis, and in response to DNA damage normal accumulation of p53, normal induction of p53 responsive genes, and normal G(1)-S and G(2)-M cell cycle arrest. BLM localizes to nuclear foci referred to as PML nuclear bodies (NBs). Cells from Li-Fraumeni syndrome patients carrying p53 germline mutations and LCLs lacking a functional p53 have a decreased accumulation of BLM in NBs, whereas isogenic lines with functional p53 exhibit normal accumulation. Certain BLM mutants (C1055S or Delta133-237) that have a reduced ability to localize to the NBs when expressed in normal cells can impair the localization of wild type BLM to NBs and block p53-mediated apoptosis, suggesting a dominant-negative effect. Taken together, our results indicate both a novel mechanism of p53 function by which p53 mediates nuclear trafficking of BLM to NBs and the cooperation of p53 and BLM to induce apoptosis.


Subject(s)
Adenosine Triphosphatases/chemistry , Adenosine Triphosphatases/metabolism , Apoptosis/physiology , Bloom Syndrome/enzymology , Cell Cycle/physiology , DNA Damage , DNA Helicases/chemistry , DNA Helicases/metabolism , Tumor Suppressor Protein p53/chemistry , Tumor Suppressor Protein p53/metabolism , Apoptosis/radiation effects , Binding Sites , Bloom Syndrome/genetics , Cell Line , Cell Nucleus/physiology , Cell Survival , Dose-Response Relationship, Radiation , Fibroblasts/cytology , Fibroblasts/physiology , Fibroblasts/radiation effects , Fluorescent Antibody Technique, Indirect , Gamma Rays , Genes, Reporter , Humans , RecQ Helicases , Recombinant Proteins/metabolism , Reference Values , Transfection
19.
Cancer Res ; 61(3): 943-9, 2001 Feb 01.
Article in English | MEDLINE | ID: mdl-11221888

ABSTRACT

RasGRP represents the prototype of a new class of guanine nucleotide exchange factors that activate small GTPases. The guanyl nucleotide-releasing protein (GRP) family members contain catalytic domains related to CDC25, the Ras exchange factor of Saccharomyces cerevisiae. They also contain a motif resembling a pair of calcium-binding EF-hands and a C1 domain similar to the diacylglycerol interaction domain of protein kinase C. The sequence of KIAA0846, identified in a human brain cDNA library, encodes a member of the GRP family that we refer to as RasGRP3. We show here that RasGRP3 bound phorbol esters with high affinity. This binding depended on anionic phospholipids, which is characteristic of phorbol ester binding to C1 domain proteins. In addition, phorbol esters also caused activation of the RasGRP3 exchange activity in intact cells, as determined by an increase in RasGTP and phosphorylation of the extracellular-regulated kinases. Finally, both phorbol 12-myristate 13-acetate and the diacylglycerol analogue 1,2-dioctanoyl-sn-glycerol induced redistribution of RasGRP3 to the plasma membrane and/or perinuclear area in HEK-293 cells, as demonstrated using a green fluorescent fusion protein. We conclude that RasGRP3 serves as a PKC-independent pathway to link the tumor-promoting phorbol esters with activation of Ras GTPases.


Subject(s)
Caenorhabditis elegans Proteins , Carcinogens/pharmacology , Guanine Nucleotide Exchange Factors/metabolism , Phorbol Esters/pharmacology , Amino Acid Sequence , Animals , Carcinogens/metabolism , Carrier Proteins , Cell Line , Cell Membrane/metabolism , Chromosome Mapping , Enzyme Activation , Humans , Kinetics , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3 , Mitogen-Activated Protein Kinases/metabolism , Molecular Sequence Data , Monomeric GTP-Binding Proteins/metabolism , Phorbol Esters/metabolism , Protein Kinase C/metabolism , Protein Structure, Tertiary , Rats , Receptors, Drug/metabolism , Sequence Homology, Amino Acid , Subcellular Fractions/metabolism , Tetradecanoylphorbol Acetate/metabolism , Tetradecanoylphorbol Acetate/pharmacology , ras Guanine Nucleotide Exchange Factors
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