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Rees C, Sheard C. Evaluating first-year medical students' attitudes to learning communication skills before and after a communication skills course. MEDICAL TEACHER 2003; 25:302-307. [PMID: 12881055 DOI: 10.1080/0142159031000100409] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This longitudinal study explores 216 medical students' attitudes towards communication skills learning before (TI) and at the end (72) of their first-year communication skills course. They completed the Communication Skills Attitude Scale and a personal details questionnaire satisfactorily at Ti and T2. Univariate statistics established whether attitudes differed between TI and T2 for the whole sample and for the sample split by demographic and education-related characteristics. Students rated their communication skills slightly but significantly lower at the end of their communication skills course than before the start of the course. Positive attitudes towards communication skills learning became significantly lower by the end of the course compared with the start. Repeated measures ANOVAs indicated that significant two-way interactions existed between attitudes at TI and T2 and the demographic characteristics: gender, language and ethnicity. These findings are discussed in the paper, along with their implications for educational practice and further research.
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Beale P, Judson I, O'Donnell A, Trigo J, Rees C, Raynaud F, Turner A, Simmons L, Etterley L. A Phase I clinical and pharmacological study of cis-diamminedichloro(2-methylpyridine) platinum II (AMD473). Br J Cancer 2003; 88:1128-34. [PMID: 12671715 PMCID: PMC2376375 DOI: 10.1038/sj.bjc.6600854] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AMD473 is a novel sterically hindered platinum cytotoxic with demonstrated ability to overcome acquired resistance to cisplatin in vitro and in human tumour xenografts. A single-agent dose escalating Phase I study was performed. AMD473 was initially administered intravenously as a 1 h infusion every 21 days to patients with advanced solid tumours. In total, 42 patients received a total of 147 cycles (median 3, range 1-8) of treatment at doses of 12, 24, 48, 96, 110, 120, 130, and 150 mg m(-2). Dosing intervals of 21 and 28 days were explored at the recommended dose. Neutropenia and thrombocytopenia proved dose limiting. Other toxicities included moderate nausea, vomiting, anorexia, and a transient metallic taste. There was no significant alopecia. The maximum tolerated dose was 150 mg m(-2). Plasma pharmacokinetics were linear. Two patients with heavily pretreated ovarian cancer showed partial response. Five patients (mesothelioma, ovary, nonsmall cell lung, and melanoma) showed prolonged stable disease. AMD473 demonstrates encouraging activity in patients, including those with prior platinum exposure. Toxicity is predictable with linear pharmacokinetics, as was predicted by preclinical studies. A dose of 120 mg m(-2) every 21 days is recommended for Phase II evaluation although there is evidence that chemo-naive patients and those of good performance status may tolerate a higher dose.
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Rees C, O'Brien ME. Palliative radiotherapy for lung cancer: is it enough? Clin Oncol (R Coll Radiol) 2002; 13:202-3. [PMID: 11527296 DOI: 10.1053/clon.2001.9254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Herráez P, Rees C, Dunstan R. Invasive phaeohyphomycosis caused by Curvularia species in a dog. Vet Pathol 2001; 38:456-9. [PMID: 11467482 DOI: 10.1354/vp.38-4-456] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A 2-year-old female Boxer dog was presented with a history of skin lesions that started 1 month after being given oral glucocorticoids for a neurologic problem. Clinically, the animal had focal areas of alopecia with papules and nodules often with ulceration overlain by crusts. Lesions were most common on the dorsum and the lateral aspects of the trunk and extremities. Histologic evaluation revealed pigmented fungal organisms within the lumina of hair follicles and throughout the dermis and subcutis. These organisms were associated with a multinodular, pyogranulomatous luminal folliculitis/furunculosis, dermatitis, and panniculitis. Curvularia sp. was isolated from the cutaneous lesions. The histologic identification of dematiaceous fungal organisms in the hair follicles may explain how phaeohyphomycosis can occur without history of a penetrating injury.
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Abstract
AIM This article reports on a small survey conducted in one NHS trust to establish the number of people with a learning disability known by staff to have committed, or be alleged to have committed, an offence. METHOD A sample of 35 members of staff who were likely to be in contact with this client group were sent questionnaires. Thirty responses were received, giving a response rate of 86 per cent. RESULTS A total of four nurses and two clinical psychologists were in contact with 31 individuals known or alleged to have committed an offence. These offences were mainly sexual and some were violent. Several individuals had committed a number of separate offences. Respondents felt that the needs of these individuals were not adequately met by current service provision. CONCLUSION A planned inter-agency response is required to deal with people with learning disabilities who carry out criminal offences, rather than the current system which is vague in terms of allocating responsibility for action. The nurse's role in providing sexual health education for those with learning disabilities also needs to be considered in the light of the survey results.
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Sprando RL, Collins TF, Wiesenfeld P, Babu US, Rees C, Black T, Olejnik N, Rorie J. Testing the potential of flaxseed to affect spermatogenesis: morphometry. Food Chem Toxicol 2000; 38:887-92. [PMID: 11039322 DOI: 10.1016/s0278-6915(00)00080-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Quantitative information was collected on male reproductive effects of maternal and postnatal dietary exposure to flaxseed (20 or 40%), flaxmeal (13 or 26%) or standard NIH AIN-93 feed (0% flaxseed control). Measurements were made on the testes of F1 generation males rats (1) whose mothers were exposed to the diets designated above, and (2) who, after weaning, were placed on the same diet as their mothers for an additional 70 days. The seminiferous tubules comprised 86%, 84%, 84%, 84% and 85% of the total testis volume while the interstitial space comprised 12%, 14%, 14%, 14%, 13% of the total testis volume for the 0% flaxseed/flaxmeal, 20% flaxseed, 13% flaxmeal, 40% flaxseed and 26% flaxmeal groups, respectively. Statistically significant decreases in the absolute volume of the seminiferous tubules were observed in the 20% and 40% flaxseed-treated groups when these groups were compared to controls. Borderline statistically significant differences were also observed when Sertoli cell nucleolar number per tubular cross-section were compared in the 13% flaxmeal and 20% flaxseed treatment groups. These effects were not considered biologically significant because other parameters of male reproductive function appeared normal. Overall, the quantitative information obtained suggests that exposure to flaxseed/flaxmeal at the doses used in the present study does not adversely affect testis structure or spermatogenesis in the rat.
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Ross DT, Scherf U, Eisen MB, Perou CM, Rees C, Spellman P, Iyer V, Jeffrey SS, Van de Rijn M, Waltham M, Pergamenschikov A, Lee JC, Lashkari D, Shalon D, Myers TG, Weinstein JN, Botstein D, Brown PO. Systematic variation in gene expression patterns in human cancer cell lines. Nat Genet 2000; 24:227-35. [PMID: 10700174 DOI: 10.1038/73432] [Citation(s) in RCA: 1573] [Impact Index Per Article: 65.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We used cDNA microarrays to explore the variation in expression of approximately 8,000 unique genes among the 60 cell lines used in the National Cancer Institute's screen for anti-cancer drugs. Classification of the cell lines based solely on the observed patterns of gene expression revealed a correspondence to the ostensible origins of the tumours from which the cell lines were derived. The consistent relationship between the gene expression patterns and the tissue of origin allowed us to recognize outliers whose previous classification appeared incorrect. Specific features of the gene expression patterns appeared to be related to physiological properties of the cell lines, such as their doubling time in culture, drug metabolism or the interferon response. Comparison of gene expression patterns in the cell lines to those observed in normal breast tissue or in breast tumour specimens revealed features of the expression patterns in the tumours that had recognizable counterparts in specific cell lines, reflecting the tumour, stromal and inflammatory components of the tumour tissue. These results provided a novel molecular characterization of this important group of human cell lines and their relationships to tumours in vivo.
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Nam TJ, Busby WH, Rees C, Clemmons DR. Thrombospondin and osteopontin bind to insulin-like growth factor (IGF)-binding protein-5 leading to an alteration in IGF-I-stimulated cell growth. Endocrinology 2000; 141:1100-6. [PMID: 10698186 DOI: 10.1210/endo.141.3.7386] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Insulin-like growth factor (IGF)-binding protein-5 (IGFBP-5) has been shown to bind to extracellular matrix (ECM) with relatively high affinity, but the ECM components that mediate this interaction have not been identified. These studies show that radiolabeled IGFBP-5 specifically coprecipitates with two ECM proteins, thrombospondin-1 (TSP-1) and osteopontin (OPN). As TSP-1 binds avidly to heparin, as does IGFBP-5, the effect of glycosaminoglycans on the TSP-1/IGFBP-5 interaction was analyzed. Heparan and dermatan sulfate inhibited binding, whereas heparin increased binding. Chondroitin sulfate A and B had no effect. In contrast, both heparin and heparan sulfate significantly inhibited the OPN-IGFBP-5 interaction and chondroitin sulfate A, B, and C had no effect. To determine the region of IGFBP-5 that was involved in each interaction, synthetic peptides that spanned several regions of IGFBP-5 were tested for their capacity to competitively inhibit coprecipitation. A peptide that contained the amino acids between positions 201 and 218 resulted in 76% and 86% inhibition of binding to TSP-1 and OPN, respectively. Three other synthetic peptides that spanned regions ofIGFBP-5 with several charged residues had no effect. IGFBP-5 mutants that contained substitutions for basic residues in the 201-218 region were tested for their ability to bind to TSP-1 or OPN. A mutant with substitutions for amino acids at positions R201 and K202 and a mutant with substitutions for K211, R214, K217, and R218 had the greatest reduction in binding to TSP-1. Mutants containing substitutions for R214 alone and the combined K217A, R218A mutant had the greatest reductions in OPN binding. When the smooth muscle cell growth response to these components was assessed, IGF-I plus IGFBP-5 or the combination of TSP-1 or OPN with IGF-I potentiated the IGF-I effect. The addition of IGFBP-5 to these combinations resulted in further significant growth stimulation. Both OPN and TSP-1 specifically bind to IGFBP-5 with high affinity. These interactions may be important for concentrating intact IGFBP-5 in extracellular matrix and for modulating the cooperative interaction between the IGF-I receptor and integrin receptor signaling pathways.
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Abstract
This week's National Association of Theatre Nurses' annual congress will be an opportunity to explore how the changes in theatre nursing reflect wider changes in nursing generally.
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Trigo J, Rees C, Beale P, Mitchell F, Jackman A, Smith R, Hutchison M, Smith M, Judson I. Phase I trial of ZD9331, a non-polyglutamatable thymidylate synthase inhibitor given as a 5-day continuous infusion every 3 weeks. Eur J Cancer 1999. [DOI: 10.1016/s0959-8049(99)81569-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Abstract
Nurse researchers have developed a range of approaches to increase knowledge. In this article, the increasingly influential approach of historical research is described to illustrate the processes and skills involved, and stimulate interest in the study of nursing history. The authors describe the process in the context of a study reported in Nursing Standard (vol 13, no 26) of the impact of pneumoconiosis on miners in South Wales (Howells 1997, Howells and Rees 1999).
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Howells G, Rees C. Pneumoconiosis: a study of its effect on miners' health in South Wales 1900-1980. Nurs Stand 1999; 13:39-41. [PMID: 10347463 DOI: 10.7748/ns1999.03.13.26.39.c7500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Since its discovery in the late 19th century, pneumoconiosis has shaped the lives of thousands of miners. In some ways it became inextricably linked to the South Wales coal field and was a major public health threat to the men who worked in those mines. The disease was caused by the conditions of work and worsened the situation of many who were already living in poverty. This historical research account traces the miners' plight and touches on some of the public health issues raised by the disease.
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Abstract
The situation in Russia shows the long-term problems of under-funding and under-valuing healthcare staff. On a recent visit, the authors found no cohesive public health strategy, without which the people are unable to develop health conscious attitudes.
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Rees C, Clemmons D. Inhibition of IGFBP-5 binding to extracellular matrix and IGF-I–stimulated DNA synthesis by a peptide fragment of IGFBP-5. J Cell Biochem 1998. [DOI: 10.1002/(sici)1097-4644(19981201)71:3<375::aid-jcb6>3.0.co;2-m] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Rees C, Clemmons DR. Inhibition of IGFBP-5 binding to extracellular matrix and IGF-I-stimulated DNA synthesis by a peptide fragment of IGFBP-5. J Cell Biochem 1998; 71:375-81. [PMID: 9831074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Insulin-like growth factor binding protein-5 (IGFBP-5) is synthesized and secreted by smooth muscle cells (SMC). IGFBP-5 synthesis is stimulated five- to sixfold by IGF-I, and IGFBP-5 has been shown to augment IGF-I-stimulated DNA synthesis in this cell type. The ability of IGFBP-5 to augment the SMC response to IGF-I is dependent upon its binding to extracellular matrix. A highly charged region of IGFBP-5 that contains amino acids in positions 201-218 has been shown to mediate binding of IGFBP-5 to human fibroblast extracellular matrix (ECM), and a synthetic peptide containing this sequence inhibits IGFBP-5 binding to fibroblast ECM. In this study we show that exposure of SMC cultures that are constitutively synthesizing IGFBP-5 to a synthetic peptide (termed peptide A) containing this sequence has no effect on its synthesis but reduces its abundance within the ECM. The addition of increasing concentrations of the peptide to SMC cultures resulted in a concentration-dependent reduction in ECM-associated IGFBP-5. In contrast, a control peptide (peptide B), which contained the region of amino acids in positions 131-141 and had a similar charge-to-mass ratio, caused a minimal decrease in ECM binding. This effect was functionally significant since the addition of 10 microg/ml of peptide A inhibited the cellular replication response to 10 ng/ml IGF-I by 51%, and peptide B had no effect. The effects of peptide A were not due to nonspecific cytotoxicity since it had no inhibitory effect on the response of these cells to human serum and was associated with only minimal inhibition of the cellular response to platelet-derived growth factor. The findings suggest that inhibiting IGFBP-5 binding to porcine SMC ECM results in reduced cellular responses to IGF-I.
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Abstract
In this article, the authors provide an overview of the perceptions of theatre nursing, the current role and ways in which this may develop in the future.
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68
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Rees C, Clemmons DR, Horvitz GD, Clarke JB, Busby WH. A protease-resistant form of insulin-like growth factor (IGF) binding protein 4 inhibits IGF-1 actions. Endocrinology 1998; 139:4182-8. [PMID: 9751498 DOI: 10.1210/endo.139.10.6266] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Smooth muscle cells (SMC) secrete a serine protease that cleaves insulin-like growth factor (IGF) binding protein (IGFBP)-4 into fragments that have low affinity for IGF-1. When IGFBP-4 is added to monolayer cultures of cell types that do not secrete this protease, IGF-1 stimulation of DNA synthesis is significantly inhibited. In contrast, if cell types that secrete this protease are used, IGFBP-4 is a much less potent inhibitor. These studies were conducted to determine whether proteolysis of IGFBP-4 accounted for its reduced capacity to inhibit IGF-1-stimulated DNA synthesis. The cleavage site in IGFBP-4 that the SMC protease uses was determined to be lysine120, histidine121. A protease-resistant mutant form of IGFBP-4 was prepared, expressed, purified, and tested for biologic activity using porcine SMC cultures. Addition of the protease-resistant mutant resulted in inhibition of DNA and cell migration responses to IGF-1. The inhibition was concentration dependent and was maximal when 500 ng/ml (20 nM) of the mutant was added with 20 ng/ml (2.8 nM) of IGF-1. When the mutant was added in the absence of IGF-1, it had no activity. The results show that cleavage of IGFBP-4 at lysine120, histidine121 results in inactivation of the ability of IGFBP-4 to bind to IGF-1. Creation of a mutant form of IGFBP-4 that was not cleaved by the protease resulted in inhibition of IGF-1-stimulated actions. The results suggest that IGFBP-4 can act as a potent inhibitor of the anabolic effects of IGF-1 and that the variables that regulate protease activity may indirectly regulate IGF-1 actions.
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Parker A, Rees C, Clarke J, Busby WH, Clemmons DR. Binding of insulin-like growth factor (IGF)-binding protein-5 to smooth-muscle cell extracellular matrix is a major determinant of the cellular response to IGF-I. Mol Biol Cell 1998; 9:2383-92. [PMID: 9725901 PMCID: PMC25505 DOI: 10.1091/mbc.9.9.2383] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Insulin-like growth factor-binding protein-5 (IGFBP-5) has been shown to bind to fibroblast extracellular matrix (ECM). Extracellular matrix binding of IGFBP-5 leads to a decrease in its affinity for insulin-like growth factor-I (IGF-I), which allows IGF-I to better equilibrate with IGF receptors. When the amount of IGFBP-5 that is bound to ECM is increased by exogenous addition, IGF-I's effect on fibroblast growth is enhanced. In this study we identified the specific basic residues in IGFBP-5 that mediate its binding to porcine smooth-muscle cell (pSMC) ECM. An IGFBP-5 mutant containing alterations of basic residues at positions 211, 214, 217, and 218 had the greatest reduction in ECM binding, although three other mutants, R214A, R207A/K211N, and K202A/R206N/R207A, also had major decreases. In contrast, three other mutants, R201A/K202N/R206N/R208A, and K217N/R218A and K211N, had only minimal reductions in ECM binding. This suggested that residues R207 and R214 were the most important for binding, whereas alterations in K211 and R218, which align near them, had minimal effects. To determine the effect of a reduction in ECM binding on the cellular replication response to IGF-I, pSMCs were transfected with the mutant cDNAs that encoded the forms of IGFBPs with the greatest changes in ECM binding. The ECM content of IGFBP-5 from cultures expressing the K211N, R214A, R217A/R218A, and K202A/R206N/R207A mutants was reduced by 79.6 and 71.7%, respectively, compared with cells expressing the wild-type protein. In contrast, abundance of the R201A/K202N/R206N/R208A mutant was reduced by only 14%. Cells expressing the two mutants with reduced ECM binding had decreased DNA synthesis responses to IGF-I, but the cells expressing the R201A/K202N/R206N/R208A mutant responded well to IGF-I. The findings suggest that specific basic amino acids at positions 207 and 214 mediate the binding of IGFBP-5 to pSMC/ECM. Smooth-muscle cells that constitutively express the mutants that bind weakly to ECM are less responsive to IGF-I, suggesting that ECM binding of IGFBP-5 is an important variable that determines cellular responsiveness.
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Abstract
Hope is an important aspect of life. Although nursing can play a part in encouraging hope, we seem to be in danger of neglecting this aspect of care. This article examines the meaning of hope, and suggests ways in which the nurse may inspire hope in those who need it.
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Grasser KD, Teo SH, Lee KB, Broadhurst RW, Rees C, Hardman CH, Thomas JO. DNA-binding properties of the tandem HMG boxes of high-mobility-group protein 1 (HMG1). EUROPEAN JOURNAL OF BIOCHEMISTRY 1998; 253:787-95. [PMID: 9654080 DOI: 10.1046/j.1432-1327.1998.2530787.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
High-mobility-group protein 1 (HMG1) is a conserved chromosomal protein with two homologous DNA-binding HMG-box domains, A and B, linked by a short basic region to an acidic carboxy-terminal tail. NMR spectroscopy on the free didomain (AB) shows that the two HMG boxes do not interact. The didomain has a higher affinity for all DNA substrates tested than single HMG-box domains and has a significantly higher ability to distort DNA by bending and supercoiling. The interaction of the didomain with DNA is stabilized by the presence of the basic region (approximately 20 residues, 9 of which are Lys) that links the second HMG box to the acidic tail in intact HMG1; this may be, at least in part, why this region also enhances supercoiling of relaxed circular DNA by the didomain and circularization of short DNA fragments (in the presence of ligase). Competition assays suggest significantly different structure-specific preferences of single and tandem HMG boxes for four-way junction and supercoiled plasmid DNA. Binding to supercoiled DNA appears to be promoted by protein oligomerization, which is pronounced for the didomains. Electron microscopy suggests that the oligomers are globular aggregates, associated with DNA looping. One box versus two (or several) is likely to be an important determinant of the properties of (non-sequence specific) HMG-box proteins.
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Imai Y, Busby WH, Smith CE, Clarke JB, Garmong AJ, Horwitz GD, Rees C, Clemmons DR. Protease-resistant form of insulin-like growth factor-binding protein 5 is an inhibitor of insulin-like growth factor-I actions on porcine smooth muscle cells in culture. J Clin Invest 1997; 100:2596-605. [PMID: 9366575 PMCID: PMC508461 DOI: 10.1172/jci119803] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
IGFs are pleiotrophic mitogens for porcine smooth muscle cells (pSMC) in culture. The effects of IGFs on cells are modulated by various insulin-like growth factor-binding proteins (IGFBP). IGFBP-5 is synthesized by pSMC and binds to the extracellular matrix. However, IGFBP-5 is also secreted into conditioned medium of cultured cells and is cleaved into fragments by a concomitantly produced protease. These fragments have reduced affinity for the IGFs and cleavage makes it difficult to assess the role of intact IGFBP-5. To study the consequence of accumulation of intact IGFBP-5 in medium, we determined the cleavage site in IGFBP-5 and prepared a protease resistant mutant. Amino acid sequencing of purified IGFBP-5 fragments suggested Arg138-Arg139 as the primary cleavage site. Arg138-Arg139-->Asn138-Asn139 mutations were introduced to create protease-resistant IGFBP-5, which has the same affinity for IGF-I as the native protein. This mutant IGFBP-5 remained intact even after 24 h of incubation and it inhibited several IGF-I actions when added to pSMC culture medium. The mutant IGFBP-5 (500 ng/ml) decreased IGF-I stimulated cellular DNA synthesis by 84%, protein synthesis by 77%, and it inhibited IGF-I stimulated migration of pSMC by 77%. It also inhibited IGF-I stimulation of IRS-1 phosphorylation. In contrast, the same amount of native IGFBP-5 did not inhibit IGF-I actions. The significance of inhibitory effects of the protease resistant IGFBP-5 was further demonstrated in pSMC transfected with mutant or native IGFBP-5 cDNAs. The mutant IGFBP-5 accumulated in culture medium of transfected cells, while native IGFBP-5 was degraded into fragments, PSMC overexpressing the mutant IGFBP-5 also responded poorly to IGF-I compared with mock transfected cells. IGF-I (5 ng/ml) increased [35S]methionine incorporation into control cells by 36% above the basal level, but it did not significantly change (4%) in pSMC cultures that were producing the mutant IGFBP-5. In conclusion, the accumulation of protease-resistant IGFBP-5 in the medium was inhibitory to IGF-I actions on pSMC. This suggests that proteolysis can prevent IGFBP-5 from acting as an inhibitor of IGF-I-stimulated effects and that it serves as an important mechanism for regulating cellular responsiveness to IGF-I.
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Rees C, Lehane M. Return to Ecstasy. Nurs Stand 1997; 11:24-25. [PMID: 9325982 DOI: 10.7748/ns.11.46.24.s36] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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75
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O'Brien M, Bromelow K, Prendiville J, Rees C, Hill M, Stanford J, Grange J, Farzaneh F, Smith I, Souberbielle B. 635 A study of SRL 172 (mycobacterium vaccae) as the first component of a tumour vaccine with immunological changes and clinical activity in patients with lung cancer. Lung Cancer 1997. [DOI: 10.1016/s0169-5002(97)80015-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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