101
|
Avalos G, Freeman C, Dunne F. Determining the quality of the medical educational environment at an Irish medical school using the DREEM inventory. IRISH MEDICAL JOURNAL 2007; 100:522-5. [PMID: 17886524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
A Cross-Sectional study using the already validated Dundee Ready Educational Environment (DREEM) questionnaire was used to assess the Undergraduate Medical Educational Environment in an Irish Medical School during the first semester 2004/2005. 389 of 476 students (82%) completed the questionnaire. The mean total score was 130 out of a maximum of 200 (65%) indicating relative satisfaction with the environment but with room for improvement. There were no individual areas of excellence identified. The following two areas were identified as being problematic (a) lack of a support system for stressed students (b) over emphasis on memorization of facts. These areas were perceived by clinical students to be greater when compared to pre-clinical students. Female students appeared happier in their environment but male students were more confident about passing exams. Non-Irish students had a lower overall score when compared to Irish students. The DREEM is a useful tool to assess the overall teaching environment and highlight areas of weakness. Use of DREEM as a monitoring tool would be useful to re-evaluate the environment following appropriate intervention.
Collapse
|
102
|
Sharples L, Buxton M, Caine N, Cafferty F, Demiris N, Dyer M, Freeman C. Evaluation of the ventricular assist device programme in the UK. Health Technol Assess 2006; 10:1-119, iii-iv. [PMID: 17134596 DOI: 10.3310/hta10480] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVES To summarise the relevant clinical effectiveness and cost-effectiveness literature, to collect data on survival, transplantation rates, health-related quality of life (HRQoL) and resource use for ventricular assist device (VAD) and non-VAD transplant candidates in the UK, and to construct cost-effectiveness and cost-utility models of VADs in a UK context. Also to investigate the factors that drive costs and survival. DESIGN A comprehensive systematic review was carried out. Data were collected from April 2002 to December 2004, with follow-up to March 2005. Cost-effectiveness and cost-utility models of VAD devices were developed based on UK activity and outcomes collected from April 2002 to March 2005. SETTING National Specialist Commissioning Advisory Group funded VAD implantation was carried out at the Freeman, Harefield and Papworth transplant centres in the UK. PARTICIPANTS Seventy patients were implanted with a VAD as a bridge to transplantation between April 2002 and December 2004. Non-VAD-supported transplant candidates (n = 250), listed at the three centres between April 2002 and December 2004, were divided into an inotrope-dependent group (n = 71) and a non-inotrope-dependent group (n = 179). Although patients in the inotrope-dependent group were closest to the VAD group they were less sick. The last group comprised a hypothetical worst case scenario, which assumed that all VAD patients would die in the intensive care unit (ICU) within 1 month without VAD technology. INTERVENTIONS Patients were included who were implanted with a VAD designed for circulatory support for more than 30 days, with intention to bridge to transplantation. A multistate model of VAD and transplant activity was constructed; this was populated by data from the UK. MAIN OUTCOME MEASURES Survival from VAD implant or from transplant listing for non-VAD patients to 31 March 2005. Serious adverse events and quality of life measures were used. Cognitive functioning was also assessed. Utility weights were derived from EuroQoL responses to estimate quality-adjusted life-years (QALYs). Incremental cost-effectiveness ratios (ICERs) were defined as the additional cost of VADs divided by additional QALYs. Time-horizons were 3 years, 10 years and the lifetime of the patients. RESULTS Of 70 VAD patients, 30 (43%) died pretransplant, 31 (44%) underwent transplantation, and four (6%) recovered and had the VAD removed. Five patients (7%) were still supported for median of 279 days at the end of March 2005. Successful bridge-to-transplantation/recovery rates were consistent with published rates. Survival from VAD implantation was 74% at 30 days and 52% at 12 months. There were 320 non-fatal adverse events in 62 patients during 300 months of VAD support, mostly in the first month after implantation. Commonly observed events were bleeding, infection and respiratory dysfunction. Twenty-nine (41%) patients were discharged from hospital with a VAD. The 1-year survival post-transplantation was 84%. For the inotrope-dependent and non-inotrope-dependent transplant candidates, death rates while listed were 10% and 8% and the median waiting times were 16 and 87 days, respectively. For transplant recipients, 1-year survival was 85% and 84%, respectively. Both VAD and non-VAD patients demonstrated similar significant improvements in their New York Heart Association class after transplantation. All patients had poor EQ-5D pretransplantation; after transplantation the groups had similar EQ-5D of 0.76 irrespective of time after surgery. HRQoL was poor in the first month for VAD patients but better for those who waited longer in all groups. VAD patients reported more problems with sleep and rest and with ambulation in the first month. Symptom scores were similar in all groups pretransplant. After transplantation all groups showed a marked and similar improvement in physical and psychosocial function. Mean VAD implant cost, including device, was pound 63,830, with costs of VAD support for survivors of pound 21,696 in month 1 and pound 11,312 in month 2. Main cost drivers were device itself, staffing, ICU stay, hospital stay and events such as bleeding, stroke and infection. For the base case, extrapolating over the lifetime of the patients the mean cost for a VAD patient was pound 173,841, with mean survival of 5.63 years and mean QALYs of 3.27. Corresponding costs for inotrope-dependent patients were pound 130,905, with mean survival 8.62 years and mean QALYs 4.99. Since inotrope-dependent patients had lower costs and higher QALYs than VAD patients, this group is said to be dominant. Non-inotrope-dependent transplant candidates had similar survival rates to those on inotropes but lower costs, also dominant. Compared with the worst case scenario the mean lifetime ICER for VADs was pound 49,384 per QALY. In a range of sensitivity analyses this ranged from pound 35,121 if the device cost was zero to pound 49,384. Since neither inotrope-dependent transplant candidates nor the worst case scenario were considered fair controls the assumption was investigated that, without VAD technology, there would be a mixture of these situations. For mixtures considered the ICER for VADs ranged from pound 79,212 per QALY to the non-VAD group being both cheaper and more effective. CONCLUSIONS There are insufficient data from either published studies or the current study to construct a fair comparison group for VADs. Overall survival of 52% is an excellent clinical achievement for those young patients with rapidly failing hearts. However, if the worst case scenario were plausible, and one could reliably extrapolate results to the lifetime of the patients, VADs would not be cost-effective at traditional thresholds. Further randomised controlled trials are required, using current second generation devices or subsequent devices and conducted in the UK.
Collapse
|
103
|
Parker W, Filion E, Roberge D, Freeman C. 2577. Int J Radiat Oncol Biol Phys 2006. [DOI: 10.1016/j.ijrobp.2006.07.990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
104
|
Myers S, Spencer CCA, Auton A, Bottolo L, Freeman C, Donnelly P, McVean G. The distribution and causes of meiotic recombination in the human genome. Biochem Soc Trans 2006; 34:526-30. [PMID: 16856851 DOI: 10.1042/bst0340526] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Using the statistical analysis of genetic variation, we have developed a high-resolution genetic map of recombination hotspots and recombination rate variation across the human genome. This map, which has a resolution several orders of magnitude greater than previous studies, identifies over 25,000 recombination hotspots and gives new insights into the distribution and determination of recombination. Wavelet-based analysis demonstrates scale-specific influences of base composition, coding context and DNA repeats on recombination rates, though, in contrast with other species, no association with DNase I hypersensitivity. We have also identified specific DNA motifs that are strongly associated with recombination hotspots and whose activity is influenced by local context. Comparative analysis of recombination rates in humans and chimpanzees demonstrates very high rates of evolution of the fine-scale structure of the recombination landscape. In the light of these observations, we suggest possible resolutions of the hotspot paradox.
Collapse
|
105
|
Faria S, Lishona R, Stern J, Souhami L, Portelance L, Devic S, Freeman C. 172 Pre- and post-treatment PET/CT to evaluate the response of non-small cell lung cancer (NSCLC) treated with curative radiotherapy alone (RT). Radiother Oncol 2006. [DOI: 10.1016/s0167-8140(06)80913-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
106
|
Faria S, Menard S, Devic S, Lisbona R, Sirois C, Souhami L, Freeman C. 21 The impact of FDG-PET on radiation therapy gross tumour volume (GTV) delineation in non-small cell lung cancer (NSCLC) may be smaller than predicted. Radiother Oncol 2006. [DOI: 10.1016/s0167-8140(06)80762-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
107
|
Evans M, Olivares M, Seuntjens J, Parker W, Devic S, Poli E, Freeman C, Podgorsak E. SU-FF-T-387: Rotational Total Skin Electron Irradiation Using a Commercially Available Linear Accelerator with a High Dose Rate Total Body Electron Mode. Med Phys 2006. [DOI: 10.1118/1.2241304] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
108
|
Evans M, Olivares M, Seuntjens J, Parker W, Devic S, Poli E, Freeman C, Podgorsak E. Sci-Sat AM (2) Therapy-01: A rotational total skin electron irradiation technique using a linear accelerator with a commercially available high dose rate total body electron mode. Med Phys 2006. [DOI: 10.1118/1.2244697] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
109
|
McCrory RL, Meyerhofer DD, Loucks SJ, Skupsky S, Betti R, Boehly TR, Collins TJ, Craxton RS, Delettrez JA, Edgell DH, Epstein R, Fletcher KA, Freeman C, Frenje JA, Glebov VY, Goncharov VN, Harding DR, Igumenshchev IV, Keck RL, Kilkenny JD, Knauer JP, Li CK, Marciante J, Marozas JA, Marshall FJ, Maximov AV, McKenty PW, Morse SF, Myatt J, Padalino S, Petrasso RD, Radha PB, Regan SP, Sangster TC, Séguin FH, Seka W, Smalyuk VA, Soures JM, Stoeckl C, Yaakobi B, Zuegel JD. Progress in direct-drive inertial confinement fusion research at the laboratory for laser energetics. ACTA ACUST UNITED AC 2006. [DOI: 10.1051/jp4:2006133013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
|
110
|
Shackle V, Freeman C, Reynolds B. Exogenous enzyme supplements to promote treatment efficiency in constructed wetlands. THE SCIENCE OF THE TOTAL ENVIRONMENT 2006; 361:18-24. [PMID: 16213577 DOI: 10.1016/j.scitotenv.2005.09.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2004] [Revised: 09/02/2005] [Accepted: 09/10/2005] [Indexed: 05/04/2023]
Abstract
Extracellular enzymes play a central role in the breakdown of organic pollutants. In wetlands constructed to treat wastewaters, supplementing the naturally occurring soil enzymes may result in faster pollutant removal, or breakdown of novel pollutants, but only if the added enzymes could retain their catalytic activity. In this study, the persistence of exogenous enzyme supplements was investigated. Adding cellobiohydrolase and beta-glucosidase to sterilised soil increased enzyme activity (range 375-4210%); although the increased activity began to decline after just 10-15 days. Thus, without an active microbial population, enhanced enzyme activity is unlikely to be long lived. However, with the naturally occurring soil microbes present to maintain the improved biodegradative capacity, cellobiohydrolase and beta-glucosidase additions created significant increases (range 173-530%) in activity and these persisted for more than 6 weeks. These findings therefore support the proposal that enzyme additions can enhance enzymic biodegradation processes, and suggest that this may be achieved primarily through a 'pump-priming' mechanism.
Collapse
|
111
|
Freeman C, Curtis JL, Chensue SW. CCR5 and CXCR6 expression on lung CD8+ T cells correlates with COPD severity. FASEB J 2006. [DOI: 10.1096/fasebj.20.4.a209-c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
112
|
Geckle BJ, Freeman C, Anderson S, Eastman CS. Reports of Conferences, Institutes, and Seminars. SERIALS REVIEW 2005. [DOI: 10.1080/00987913.2005.10765008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
113
|
Freeman C. Roaring into Serials with the 2005 North American Serials Interest Group Annual Conference. SERIALS REVIEW 2005. [DOI: 10.1080/00987913.2005.10765009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
114
|
Aslani M, Faria S, Tafazoli F, Duclos M, Portelance L, Guerra J, Freeman C. Does the RTOG/EORTC Scoring Schema (RESS) Truly Reflect the Late Radiation Morbidity in Lung Cancer Patients? Int J Radiat Oncol Biol Phys 2005. [DOI: 10.1016/j.ijrobp.2005.07.672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
115
|
Hou RH, Freeman C, Langley RW, Szabadi E, Bradshaw CM. Does modafinil activate the locus coeruleus in man? Comparison of modafinil and clonidine on arousal and autonomic functions in human volunteers. Psychopharmacology (Berl) 2005; 181:537-49. [PMID: 15983798 DOI: 10.1007/s00213-005-0013-8] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2004] [Accepted: 03/31/2005] [Indexed: 11/29/2022]
Abstract
RATIONALE Modafinil is a wakefulness-promoting drug which is likely to activate some wakefulness-promoting and/or inhibit sleep-promoting neurones in the brain. The locus coeruleus (LC) is a wakefulness-promoting noradrenergic nucleus whose activity can be "switched off" by the alpha2-adrenoceptor agonist clonidine, leading to sedative and sympatholytic effects. OBJECTIVE The aim of the study is to compare the effects of single doses of modafinil and clonidine on arousal and autonomic functions in human volunteers. METHODS Sixteen healthy male volunteers participated in four experimental sessions (modafinil 200 mg; clonidine 0.2 mg; modafinil 200 mg + clonidine 0.2 mg; placebo) at weekly intervals, according to a balanced double-blind protocol. Arousal [pupillary "fatigue waves" (PFW), critical flicker fusion frequency, self-ratings of alertness] and autonomic functions (pupil diameter, pupillary light and darkness reflex responses, blood pressure, heart rate, salivation) were recorded. Data were analyzed with ANOVA, with multiple comparisons. RESULTS Clonidine reduced subjective alertness, pupil diameter, the initial velocity and amplitude of the darkness reflex response, systolic and diastolic blood pressure and salivation, prolonged the recovery time of the light reflex response and increased PFW. Modafinil reduced PFW, increased pupil diameter and the initial velocity of the darkness reflex response and tended to reduce the effect of clonidine on pupil diameter and PFW. Modafinil had no effect on non-pupillary autonomic functions. CONCLUSIONS Clonidine exerted sympatholytic and sedative effects, whereas modafinil had sympathomimetic and some alerting effects. Modafinil may activate noradrenergic neurones in the LC involved in arousal and pupillary control, without affecting extracoerulear noradrenergic neurones involved in cardiovascular and salivary regulation.
Collapse
|
116
|
Alyahya K, Schwartz M, Patrocinio H, Parker W, Shenouda G, Verhaegen F, Freeman C, Seuntjens J. 52 Monte Carlo-Based Inverse Planning of Modulated Electron Beam Therapy using a Few-Leaf Electron Collimator Provides Highly Conformal Treatment and Decreases Whole Body Dose. Radiother Oncol 2005. [DOI: 10.1016/s0167-8140(05)80213-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
117
|
Al-Yahya K, Schwartz M, Shenouda G, Verhaegen F, Freeman C, Seuntjens J. MO-E-T-617-02: Dosimetric Evaluation of Inverse Monte Carlo-Based Modulated Electron Beam Treatment Planning and Delivery Using a Few Leaf Electron Collimator. Med Phys 2005. [DOI: 10.1118/1.1998306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
118
|
McCain JE, Monroe KW, King WD, Freeman C. 128 DO PARENTS GIVE IBUPROFEN OR ACETAMINOPHEN TO CHILDREN PRIOR TO EMERGENCY DEPARTMENT VISITS FOR FEVER OR PAIN? J Investig Med 2005. [DOI: 10.2310/6650.2005.00006.127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
119
|
Szabadi E, Bradshaw CM, Freeman C, Scaife J, Hou RH, Langley RW. The histaminergic system of the brain: its roles in arousal and autonomic regulation. NEUROPSYCHOPHARMACOLOGIA HUNGARICA : A MAGYAR PSZICHOFARMAKOLOGIAI EGYESULET LAPJA = OFFICIAL JOURNAL OF THE HUNGARIAN ASSOCIATION OF PSYCHOPHARMACOLOGY 2004; 6:163-4. [PMID: 15816307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
|
120
|
O’Sullivan B, Davis A, Turcotte R, Bell R, Catton C, Wunder J, Hammond A, Freeman C, Marc I, Chabot P, Kandel R, Tu D. Local control with pre-operative vs. post-operative external beam radiotherapy in extremity soft-tissue sarcoma: 5 year results of a prospective randomized Phase III trial. Int J Radiat Oncol Biol Phys 2004. [DOI: 10.1016/j.ijrobp.2004.07.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
121
|
Freeman C, Fenner N, Ostle NJ, Kang H, Dowrick DJ, Reynolds B, Lock MA, Sleep D, Hughes S, Hudson J. Export of dissolved organic carbon from peatlands under elevated carbon dioxide levels. Nature 2004; 430:195-8. [PMID: 15241411 DOI: 10.1038/nature02707] [Citation(s) in RCA: 475] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2003] [Accepted: 06/02/2004] [Indexed: 11/08/2022]
Abstract
Peatlands represent a vast store of global carbon. Observations of rapidly rising dissolved organic carbon concentrations in rivers draining peatlands have created concerns that those stores are beginning to destabilize. Three main factors have been put forward as potential causal mechanisms, but it appears that two alternatives--warming and increased river discharge--cannot offer satisfactory explanations. Here we show that the third proposed mechanism, namely shifting trends in the proportion of annual rainfall arriving in summer, is similarly unable to account for the trend. Instead we infer that a previously unrecognized mechanism--carbon dioxide mediated stimulation of primary productivity--is responsible. Under elevated carbon dioxide levels, the proportion of dissolved organic carbon derived from recently assimilated carbon dioxide was ten times higher than that of the control cases. Concentrations of dissolved organic carbon appear far more sensitive to environmental drivers that affect net primary productivity than those affecting decomposition alone.
Collapse
|
122
|
Crossley D, Freeman C. Should neurosurgery for mental disorder be allowed to die out? Against. Br J Psychiatry 2003; 183:196. [PMID: 14509262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
|
123
|
Tyrer P, Thompson S, Schmidt U, Jones V, Knapp M, Davidson K, Catalan J, Airlie J, Baxter S, Byford S, Byrne G, Cameron S, Caplan R, Cooper S, Ferguson B, Freeman C, Frost S, Godley J, Greenshields J, Henderson J, Holden N, Keech P, Kim L, Logan K, Manley C, MacLeod A, Murphy R, Patience L, Ramsay L, De Munroz S, Scott J, Seivewright H, Sivakumar K, Tata P, Thornton S, Ukoumunne OC, Wessely S. Randomized controlled trial of brief cognitive behaviour therapy versus treatment as usual in recurrent deliberate self-harm: the POPMACT study. Psychol Med 2003; 33:969-976. [PMID: 12946081 DOI: 10.1017/s0033291703008171] [Citation(s) in RCA: 137] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND We carried out a large randomized trial of a brief form of cognitive therapy, manual-assisted cognitive behaviour therapy (MACT) versus treatment as usual (TAU) for deliberate self-harm. METHOD Patients presenting with recurrent deliberate self-harm in five centres were randomized to either MACT or (TAU) and followed up over 1 year. MACT patients received a booklet based on cognitive behaviour therapy (CBT) principles and were offered up to five plus two booster sessions of CBT from a therapist in the first 3 months of the study. Ratings of parasuicide risk, anxiety, depression, social functioning and global function, positive and negative thinking, and quality of life were measured at baseline and after 6 and 12 months. RESULTS Four hundred and eighty patients were randomized. Sixty per cent of the MACT group had both the booklet and CBT sessions. There were seven suicides, five in the TAU group. The main outcome measure, the proportion of those repeating deliberate self-harm in the 12 months of the study, showed no significant difference between those treated with MACT (39%) and treatment as usual (46%) (OR 0.78, 95% CI 0.53 to 1.14, P=0.20). CONCLUSION Brief cognitive behaviour therapy is of limited efficacy in reducing self-harm repetition, but the findings taken in conjunctin with the economic evaluation (Byford et al. 2003) indicate superiority of MACT over TAU in terms of cost and effectiveness combined.
Collapse
|
124
|
Freeman C, Weiner ML, Kotkoskie LA, Borzelleca J, Butt M. Subchronic and developmental toxicity studies in rats with Ac-Di-Sol croscarmellose sodium. Int J Toxicol 2003; 22:149-57. [PMID: 12851148 DOI: 10.1080/10915810305108] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Studies were conducted to evaluate the subchronic and developmental toxicity of Ac-Di-Sol (croscarmellose sodium). In the subchronic study, groups of Sprague-Dawley rats (20/sex/group) received 0 (control), 10000, or 50000 ppm Ac-Di-Sol in the diet for 90 consecutive days (equivalent to 757 and 893 mg/kg/day for males and females fed 10000 ppm, respectively, and to 3922 and 4721 mg/kg/day for males and females fed 50000 ppm, respectively). No mortality, clinical signs of toxicity, or adverse toxicological effects on hematology or serum chemistry parameters, feed consumption, or ophthalmologic examinations were noted in any treatment group. Body weight gain was depressed in high-dose males during the final 3 weeks. The only treatment-related histological lesion noted was moderate renal mineralization at the corticomedullary junction in one high-dose female. This lesion was not considered a specific effect of Ac-Di-Sol, but rather a secondary effect resulting from a potential increase in urinary pH and renal excretion of sodium due to the high intake of sodium associated with Ac-Di-Sol. In the developmental toxicity study, groups of pregnant Sprague-Dawley rats (25/group) received 0 (control), 10000, or 50000 ppm Ac-Di-Sol in the diet on gestational days 6 to 15. No evidence of maternal, fetal, or embryo toxicity was noted. The no-observed-adverse-effect level (NOAEL) for Ac-Di-Sol in both studies exceeds 50000 ppm in the diet, which represents doses of 3922 and 4712 mg/kg/day, for males and females, respectively. The results of these studies demonstrate the low subchronic oral toxicity and developmental toxicity of Ac-Di-Sol, and support the safe use of Ac-Di-Sol in oral applications such as pharmaceuticals, dietary supplements, and sweetener tablets.
Collapse
|
125
|
McColl B, Baldwin M, Roufail S, Freeman C, Moritz R, Simpson R, Alitalo K, Stacker S, Achen M. 2SY04-4 VEGF-D: A molecular regulator of lymphangiogenesis. ATHEROSCLEROSIS SUPP 2003. [DOI: 10.1016/s1567-5688(03)90391-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
126
|
Davis AM, O'Sullivan B, Bell RS, Turcotte R, Catton CN, Wunder JS, Chabot P, Hammond A, Benk V, Isler M, Freeman C, Goddard K, Bezjak A, Kandel RA, Sadura A, Day A, James K, Tu D, Pater J, Zee B. Function and health status outcomes in a randomized trial comparing preoperative and postoperative radiotherapy in extremity soft tissue sarcoma. J Clin Oncol 2002; 20:4472-7. [PMID: 12431971 DOI: 10.1200/jco.2002.03.084] [Citation(s) in RCA: 186] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
PURPOSE Morbidity associated with wound complications may translate into disability and quality-of-life disadvantages for patients treated with radiotherapy (RT) for soft tissue sarcoma (STS) of the extremities. Functional outcome and health status of extremity STS patients randomized in a phase III trial comparing preoperative versus postoperative RT is described. PATIENTS AND METHODS One hundred ninety patients with extremity STS were randomized after stratification by tumor size dichotomized at 10 cm. Function and quality of life were measured by the Musculoskeletal Tumor Society Rating Scale (MSTS), the Toronto Extremity Salvage Score (TESS), and the Short Form-36 (SF-36) at randomization, 6 weeks, and 3, 6, 12, and 24 months after surgery. RESULTS One hundred eighty-five patients had function data. Patients treated with postoperative RT had better function with higher MSTS (25.8 v 21.3, P <.01), TESS (69.8 v 60.6, P =.01), and SF-36 bodily pain (67.7 v 58.5, P =.03) scores at 6 weeks after surgery. There were no differences at later time points. Scores on the physical function, role-physical, and general health subscales of the SF-36 were significantly lower than Canadian normative data at all time points. After treatment arm was controlled for, MSTS change scores were predicted by a lower-extremity tumor, a large resection specimen, and motor nerve sacrifice; TESS change scores were predicted by lower-extremity tumor and prior incomplete excision. When wound complication was included in the model, patients with complications had lower MSTS and TESS scores in the first 2 years after treatment. CONCLUSION The timing of RT has minimal impact on the function of STS patients in the first year after surgery. Tumor characteristics and wound complications have a detrimental effect on patient function.
Collapse
|
127
|
Lane AB, Soodyall H, Arndt S, Ratshikhopha ME, Jonker E, Freeman C, Young L, Morar B, Toffie L. Genetic substructure in South African Bantu-speakers: evidence from autosomal DNA and Y-chromosome studies. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2002; 119:175-85. [PMID: 12237937 DOI: 10.1002/ajpa.10097] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The extent of genetic differentiation between seven South African Bantu-speaking groups (Zulu, Xhosa, Tsonga/Shangaan, Southern Sotho, Pedi, Tswana, and Venda) was assessed from coancestry coefficients (F(ST)) estimated from autosomal serogenetic, DNA, and Y-chromosome DNA haplotypes. The overall F(ST) obtained from the autosomal data was 0.002, and that from the Y chromosome data was 0.014. The genetic relationships between groups examined were inferred from their cluster affinities in phylogenetic trees constructed from the genetic distances between them. Both autosomal and Y-chromosome DNA studies reveal that 6 of the 7 South African Bantu-speaking groups cluster according to their linguistic groupings, the exception being the Tsonga, who do not cluster with other Nguni language speakers, but rather with the Venda who live close to them. This suggests that the invading Shangaan-speakers, whose Nguni language was adopted by the Tsonga, did not have a major effect on the Tsonga gene pool, and that gene flow from the Venda into the Tsonga may have been considerable. Genetic distances were found to correlate with geographic distances between the regions where each group's apparent population density is the highest. Linguistic distances were also found to correlate with genetic distances, but linguistic and geographic distances showed no correlation. Together, these results suggest that linguistic and some genetic differentiation took place before the groups (or their forerunners) reached their present-day locations, and that further genetic change occurred after their arrival.
Collapse
|
128
|
Freeman C, Todd C, Camilleri-Ferrante C, Laxton C, Murrell P, Palmer CR, Parker M, Payne B, Rushton N. Quality improvement for patients with hip fracture: experience from a multi-site audit. Qual Saf Health Care 2002; 11:239-45. [PMID: 12486988 PMCID: PMC1743638 DOI: 10.1136/qhc.11.3.239] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
PROBLEM The first East Anglian audit of hip fracture was conducted in eight hospitals during 1992. There were significant differences between hospitals in 90-day mortality, development of pressure sores, median lengths of hospital stay, and in most other process measures. Only about half the survivors recovered their pre-fracture physical function. A marked decrease in physical function (for 31%) was associated with postoperative complications. DESIGN A re-audit was conducted in 1997 as part of a process of continuing quality improvement. This was an interview and record based prospective audit of process and outcome of care with 3 month follow up. Seven hospitals with trauma orthopaedic departments took part in both audits. Results from the 1992 audit and indicator standards for re-audit were circulated to all orthopaedic consultants, care of the elderly consultants, and lead audit facilitators at each hospital. KEY MEASURES FOR IMPROVEMENT Processes likely to reduce postoperative complications and improve patient outcomes at 90 days. STRATEGY FOR CHANGE As this was a multi-site audit, the project group had no direct power to bring about changes within individual NHS hospital trusts. RESULTS Significant increases were seen in pharmaceutical thromboembolic prophylaxis (from 45% to 81%) and early mobilisation (from 56% to 70%) between 1992 and 1997. There were reduced levels of pneumonia, wound infection, pressure sores, and fatal pulmonary embolism, but no change was recorded in 3 month functional outcomes or mortality. LESSONS LEARNT While some hospitals had made improvements in care by 1997, others were failing to maintain their level of good practice. This highlights the need for continuous quality improvement by repeating the audit cycle in order to reach and then improve standards. Rehabilitation and long term support to improve functional outcomes are key areas for future audit and research.
Collapse
|
129
|
Brook IM, Freeman C, Lamb DJ. Implant treatment. Br Dent J 2002; 193:183. [PMID: 12222901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
|
130
|
Harrison LD, Erickson PG, Adlaf E, Freeman C. The drugs-violence nexus among American and Canadian youth. Subst Use Misuse 2001; 36:2065-86. [PMID: 11794584 DOI: 10.1081/ja-100108437] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
This paper examines the relationship between drug use and violence among representative samples of students in the United States and Ontario, Canada. Canada has significantly lower levels of violent crime than the United States, but students report similar rates of drug use. Using logistic regression analysis, we find a similar relationship between drug use and violence among adolescents in the two countries. All the drugs considered--cannabis, cocaine, and alcohol binge drinking--are significantly related to violent behavior; whether the perpetrator or the victim. The most noteworthy difference may be that in Ontario, drug use appears to be even more highly correlated with violence than in the United States.
Collapse
|
131
|
Kang H, Freeman C, Ashendon TW. Effects of elevated CO2 on fen peat biogeochemistry. THE SCIENCE OF THE TOTAL ENVIRONMENT 2001; 279:45-50. [PMID: 11712604 DOI: 10.1016/s0048-9697(01)00724-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Effects of elevated atmospheric CO2 concentration on northern peatland biogeochemistry was studied in a short-term experiment. Eight intact soil cores (11-cm diameter x 40-cm depth) with Juncus and Festuca spp. were collected from a calcareous fen in north Wales. Half of the cores were incubated under 350 ppm CO2 concentration, whilst the other four cores were maintained at 700 ppm CO2. After a 4-month incubation, significantly higher biomass (root + shoot + algal mat) was determined under elevated CO2 conditions. Higher emissions of N2O and CO2, and higher concentration of pore-water DOC (dissolved organic carbon) were also observed under elevated CO2. However, no significant differences were found in CH4 emission or soil enzyme activities (beta-glucosidase, phosphatase, and N-acetylglucosaminidase) in the bulk soil. Overall, the results suggest that elevated CO2 would increase the primary productivity of the fen vegetation, and stimulate N2O and CO2 emissions as a consequence of an enhanced DOC supply from the vegetation to the soil microbes.
Collapse
|
132
|
|
133
|
Freeman C, Brook I, Joshi R. Long-term follow-up of implant-stabilised overdentures. THE EUROPEAN JOURNAL OF PROSTHODONTICS AND RESTORATIVE DENTISTRY 2001; 9:147-50. [PMID: 12192952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
The aim of this retrospective study was to assess the long-term outcome of patients provided with implant-stabilised overdentures. Patients who had been entered into a previous trial were identified; the records were available for nineteen patients restored with conventional complete upper dentures and implant-stabilised lower overdentures. The mean follow-up period was 11.5 years (range 5.25-13.5 years). One implant was lost and all patients have successfully worn their prostheses, although most have experienced problems: loosening, loss and fracture of retaining clips, soft tissue complications and fractured bars. Nine patients subsequently had bars replaced with ball attachments. This conversion significantly reduced requirements for maintenance and professional care. Implant-stabilised lower overdentures supported on two implants provide a simple, predictable solution for patients with otherwise poorly retained and unstable lower dentures.
Collapse
|
134
|
Freeman C, Evans CD, Monteith DT, Reynolds B, Fenner N. Export of organic carbon from peat soils. Nature 2001; 412:785. [PMID: 11518954 DOI: 10.1038/35090628] [Citation(s) in RCA: 731] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
135
|
Ramsay SL, Freeman C, Grace PB, Redmond JW, MacLeod JK. Mild tagging procedures for the structural analysis of glycans. Carbohydr Res 2001; 333:59-71. [PMID: 11423111 DOI: 10.1016/s0008-6215(01)00115-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The reductive oxyamination of model glycan structures has been investigated as a mild, alternative tagging procedure to reductive amination using O-(4-nitrobenzyl)-hydroxylamine. Oxime formation was quantitative, but the reduction step did not always go to completion. Novel O- and N-substituted 7-hydroxycoumaryl- and 3-methoxybenzylhydroxylamines were synthesized and shown to couple quantitatively with model saccharides by oxime formation and reductive hydroxyamination, respectively, under very mild, aqueous conditions. The fluorescent derivatives produced show good chromatographic and mass spectrometric properties. Both procedures are suitable for the labeling of carbohydrates and oligosaccharide fragments from glycosaminoglycan structures, such as heparin and heparan sulfate.
Collapse
|
136
|
Parish CR, Freeman C, Hulett MD. Heparanase: a key enzyme involved in cell invasion. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1471:M99-108. [PMID: 11250066 DOI: 10.1016/s0304-419x(01)00017-8] [Citation(s) in RCA: 190] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
137
|
Gotfried M, Freeman C. An update on community-acquired pneumonia in adults. COMPREHENSIVE THERAPY 2001; 26:283-93. [PMID: 11126100 DOI: 10.1007/s12019-000-0031-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality, despite effective therapies. Guidelines for CAP management vary widely in their approach. Resistance of S pneumoniae to penicillins and other antibiotics has prompted evaluation of the new fluoroquinolones.
Collapse
|
138
|
Li JS, Yager E, Reilly M, Freeman C, Reddy GR, Reilly AA, Chu FK, Winslow GM. Outer membrane protein-specific monoclonal antibodies protect SCID mice from fatal infection by the obligate intracellular bacterial pathogen Ehrlichia chaffeensis. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:1855-62. [PMID: 11160232 DOI: 10.4049/jimmunol.166.3.1855] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Previous studies of Ehrlichia chaffeensis infection in the mouse have demonstrated that passive transfer of polyclonal Abs from resistant immunocompetent mice to susceptible SCID mice ameliorated infection and disease, even when Abs were administered during established infection. To identify particular Abs that could mediate bacterial clearance in vivo, E. chaffeensis-specific mAbs were generated and administered to infected SCID mice. Bacterial infection in the livers was significantly lowered after administration of either of two Abs of different isotypes (IgG2a and IgG3). Moreover, repeated administration of one Ab (Ec56.5; IgG2a) rescued mice from an otherwise lethal infection for at least 5 wk. Both protective Abs recognized the E. chaffeensis major outer membrane protein (OMP)-1g. Further studies revealed that both Abs recognized closely related epitopes within the amino terminus of the first hypervariable region of OMP-1g. Analyses of human sera showed that E. chaffeensis-infected patients also generated serological responses to OMP-1g hypervariable region 1, indicating that humans and mice recognize identical or closely related epitopes. These studies demonstrate that OMP-specific mAbs can mediate bacterial elimination in SCID mice, and indicate that Abs, in the absence of cell-mediated immunity, can play a significant role in host defense during infection by this obligate intracellular bacterium.
Collapse
|
139
|
|
140
|
Hulett MD, Hornby JR, Ohms SJ, Zuegg J, Freeman C, Gready JE, Parish CR. Identification of active-site residues of the pro-metastatic endoglycosidase heparanase. Biochemistry 2000; 39:15659-67. [PMID: 11123890 DOI: 10.1021/bi002080p] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Heparanase is a beta-D-endoglucuronidase that cleaves heparan sulfate (HS) and has been implicated in many important physiological and pathological processes, including tumor cell metastasis, angiogenesis, and leukocyte migration. We report herein the identification of active-site residues of human heparanase. Using PSI-BLAST and PHI-BLAST searches of sequence databases, similarities were identified between heparanase and members of several of the glycosyl hydrolase families (10, 39, and 51) from glycosyl hydrolase clan A (GH-A), including strong local identities to regions containing the critical active-site catalytic proton donor and nucleophile residues that are conserved in this clan of enzymes. Furthermore, secondary structure predictions suggested that heparanase is likely to contain an (alpha/beta)(8) TIM-barrel fold, which is common to the GH-A families. On the basis of sequence alignments with a number of glycosyl hydrolases from GH-A, Glu(225) and Glu(343) of human heparanase were identified as the likely proton donor and nucleophile residues, respectively. The substitution of these residues with alanine and the subsequent expression of the mutant heparanases in COS-7 cells demonstrated that the HS-degrading capacity of both was abolished. In contrast, the alanine substitution of two other glutamic acid residues (Glu(378) and Glu(396)), both predicted to be outside the active site, did not affect heparanase activity. These data suggest that heparanase is a member of the clan A glycosyl hydrolases and has a common catalytic mechanism that involves two conserved acidic residues, a putative proton donor at Glu(225) and a nucleophile at Glu(343).
Collapse
|
141
|
Freeman C, Bowers T, Fischer S. Detection of malingering on the computer Category Test and the Memory Assessment Scale. Arch Clin Neuropsychol 2000. [DOI: 10.1093/arclin/15.8.843a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
142
|
|
143
|
Weiner ML, Freeman C, Trochimowicz H, de Gerlache J, Jacobi S, Malinverno G, Mayr W, Regnier JF. 13-week drinking water toxicity study of hydrogen peroxide with 6-week recovery period in catalase-deficient mice. Food Chem Toxicol 2000; 38:607-15. [PMID: 10942322 DOI: 10.1016/s0278-6915(00)00048-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
A GLP OECD guideline study was conducted to evaluate the subchronic toxicity of hydrogen peroxide (HP) when administered continuously in the drinking water of catalase-deficient (C57BL/6N) mice and reversibility of toxic effects. Groups of mice (15/sex/group) received solutions of 0, 100, 300, 1000 or 3000 ppm HP in distilled water for 13 weeks; five/sex/group continued on untreated distilled water for an additional 6 weeks. Animals drinking 3000 ppm HP exhibited depressed water and food consumption and body weight. Females drinking 1000 ppm HP had reduced water consumption with intermittent effects on food consumption, but no body weight effects. HP administration did not produce any mortality, clinical signs, hematological effects or organ weight effects on brain, liver, kidneys, adrenals, testes, heart or spleen. Total protein and globulin were depressed among high dose males. Mild to minimal duodenal mucosal hyperplasia was noted in animals receiving 1000 and 3000 ppm HP and one male receiving 300 ppm for 13 weeks. There were no other histopathological findings. All effects noted during the treatment period, including the duodenal hyperplasia, were reversible during the 6-week recovery period. Females dosed with 300-3000 ppm HP during the treatment period showed increased water consumption during the recovery period. The no-observed-effect level (NOEL), based on duodenal mucosal hyperplasia, is 100 ppm in drinking water or 26 and 37 mg/kg/day HP, respectively, for males and females.
Collapse
|
144
|
Cali RL, Meade PG, Swanson MS, Freeman C. Effect of Morphine and incision length on bowel function after colectomy. Dis Colon Rectum 2000; 43:163-8. [PMID: 10696888 DOI: 10.1007/bf02236975] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
PURPOSE Return of bowel function remains the rate-limiting factor in shortening postoperative hospitalization of patients with colectomies. Narcotics are most commonly used in the management of postoperative pain, even though they are known to affect gut motility. Narcotic use has been felt to be proportional to the length of the abdominal incision. The aim of this study was to determine whether return of bowel function after colectomy is directly related to narcotic use and to evaluate the effect of incision length on postoperative ileus. METHODS A prospective evaluation of 40 patients who underwent uncomplicated, predominantly left colon and rectal resections was performed. Morphine administered by patient controlled analgesia was the sole postoperative analgesic. The amount of morphine used before the first audible bowel sounds, first passage of flatus and bowel movement, and incision length were recorded. Spearman correlation coefficients were calculated between all variables. RESULTS The strongest correlation was between time to return of bowel sounds and amount of morphine administered (r = 0.74; P = 0.001). There were also significant correlations between morphine use and time to report of first flatus (r = 0.47; P = 0.003) and time to bowel movement (r = 0.48; P = 0.002). There was no relationship between incision length and morphine use or incision length and return of bowel function in the total group. CONCLUSIONS Return of bowel sounds, reflecting small-intestine motility after colectomy, correlated strongly with the amount of morphine used. Similarly, total morphine use adversely affects colonic motility. Because no relationship with incision length was found, efforts to optimize the care of patients with colectomies should be directed less toward minimizing abdominal incisions and more toward diminishing use of postoperative narcotics.
Collapse
|
145
|
Palmieri MA, Freeman C, Kotkoskie LA. Developmental toxicity study of Aquacoat ECD ethylcellulose aqueous dispersion administered orally to rats. Food Chem Toxicol 2000; 38:71-4. [PMID: 10685016 DOI: 10.1016/s0278-6915(99)00116-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A developmental rat toxicity study of Aquacoat((R)) ECD was performed as part of a program to evaluate the safety of the product. Groups of 25 presumed-pregnant Charles River Sprague-Dawley CD rats received doses of 0, 903, 2709 and 4515mg/kg/day (dry weight basis) of Aquacoat ECD administered undiluted once daily via oral gavage on days 6-15 of gestation. All surviving dams underwent caesarean sectioning on day 20 of gestation. Foetuses were weighed, sacrificed and subject to external, visceral and skeletal evaluations. No test material-related maternal deaths occurred; one high-dose female died on day 14 due to gavage error. The only treatment-related clinical sign noted among dams receiving 2709mg/kg/day and greater was pale faeces which was attributed to the presence of the test material in the faeces. No statistically significant differences were noted among the measured maternal parameters. Foetal sex ratios and body weights were similar in all groups. The results of external and visceral foetal evaluations revealed no treatment-related alterations. The only statistically significant findings noted during the skeletal evaluation were increased litter incidences of incompletely ossified or wavy ribs noted among foetuses receiving 4515mg/kg/day, and a significant increase in the litter incidence of thickened ribs at doses of 2709 and 4515mg/kg/day. Given the nature of these findings and the lack of effects on any other parameter measured in this study, they were not considered adverse effects of treatment. Under the conditions of this study, the maternal and foetal no-observed-adverse-effect level (NOAEL) is in excess of 4515mg/mg/day.
Collapse
|
146
|
Freeman C, Browne AM, Parish CR. Evidence that platelet and tumour heparanases are similar enzymes. Biochem J 1999; 342 ( Pt 2):361-8. [PMID: 10455023 PMCID: PMC1220473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
In order to enter tissues, blood-borne metastatic tumour cells and leucocytes need to extravasate through the vascular basal lamina (BL), a process which involves a battery of degradative enzymes. A key degradative enzyme is the endoglycosidase heparanase, which cleaves heparan sulphate (HS), an important structural component of the vascular BL. Previously, tumour-derived heparanase activity (which has been shown to be related to the metastatic potential of murine and human melanoma cell lines) was reported to cleave HS and be inhibited by heparin, as distinct from human platelet heparanase, which cleaved both substrates [Nakajima, Irimura and Nicolson (1988) J. Cell Biochem. 36, 157-167]. We recently reported the purification of human platelet heparanase and showed that the enzyme is a 50-kDa endoglucuronidase [Freeman and Parish (1998) Biochem. J. 330, 1341-1350]. We now report the purification and characterization of heparanase activity from highly metastatic rat 13762 MAT mammary adenocarcinoma and human HCT 116 colonic carcinoma cells and from rat liver using essentially the same procedure that was reported for purification of the human platelet enzyme. The rat 13762 MAT tumour enzyme, which has a native M(r) of 45 kDa when analysed by gel-filtration chromatography and by SDS/PAGE, was observed to be an endoglucuronidase that degraded heparin and HS to fragments of the same sizes as the human platelet enzyme does. N-deglycosylation of both the human platelet and rat 13762 MAT tumour enzymes gave, in each case, a 41-kDa band by SDS/PAGE analysis, demonstrating that the observed difference in M(r) between the platelet and tumour enzymes may have been due largely to differences in the relative amounts of N-glycosylation. Two peptides were isolated following Endoproteinase Lys-C digestion of both the human platelet and rat 13762 MAT tumour heparanases and were shown to be highly similar. Both the rat liver and human colonic carcinoma heparanases also degraded both heparin and HS to fragments of the same sizes as the human platelet enzyme does. Western-blot analysis of an SDS/PAGE gel using antibodies raised against human platelet heparanase demonstrated that human platelet, human tumour and rat tumour heparanases were immunochemically cross-reactive. In conclusion, because of the similarities in their sizes, substrate specificities, peptide sequences and immunoreactivities, we propose that heparanase activities present in human platelets, rat liver and in rat and human tumour cells are, in fact, mediated by a similar enzyme.
Collapse
|
147
|
Baker E, Crawford J, Sutherland GR, Freeman C, Parish CR, Hulett MD. Human HPA endoglycosidase heparanase. Map position 4q21.3. Chromosome Res 1999; 7:319. [PMID: 10461877 DOI: 10.1023/a:1009235132576] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
148
|
Parish CR, Freeman C, Brown KJ, Francis DJ, Cowden WB. Identification of sulfated oligosaccharide-based inhibitors of tumor growth and metastasis using novel in vitro assays for angiogenesis and heparanase activity. Cancer Res 1999; 59:3433-41. [PMID: 10416607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
Inhibitors of tumor angiogenesis and metastasis are rapidly emerging as important new drug candidates for cancer therapy. To facilitate the identification of such drugs, we recently developed novel and rapid in vitro assays for human angiogenesis and for the extracellular matrix-degrading enzyme heparanase, which has been implicated in tumor metastasis. In this study, sulfated oligosaccharides, which are structural mimics of heparan sulfate, were investigated as drug candidates because these compounds may interfere with heparan sulfate recognition by many angiogenic growth factors and may inhibit cleavage of heparan sulfate by heparanase. In the preliminary screening studies, it was found that inhibitory activity in both assay systems was critically dependent on chain length and degree of sulfation, highly sulfated linear oligosaccharides of five or more monosaccharides in length being the most active. However, two sulfated oligosaccharides stood out as potential antitumor drugs, phosphomannopentaose sulfate (PI-88) and maltohexaose sulfate, both of these compounds having the important property of simultaneously being potent inhibitors of in vitro angiogenesis and heparanase activity. Due to the ease of manufacture of the starting material, phosphomannopentaose, PI-88 was studied in more detail. PI-88 was shown to inhibit the primary tumor growth of the highly invasive rat mammary adenocarcinoma 13762 MAT by approximately 50%, inhibit metastasis to the draining popliteal lymph node by approximately 40%, and reduce the vascularity of tumors by approximately 30%, all of these effects being highly significant. Acute hematogenous metastasis assays also demonstrated that PI-88 was a potent (>90%) inhibitor of blood-borne metastasis. Thus, by the use of novel in vitro screening procedures, we have identified a promising antitumor agent.
Collapse
|
149
|
Hulett MD, Freeman C, Hamdorf BJ, Baker RT, Harris MJ, Parish CR. Cloning of mammalian heparanase, an important enzyme in tumor invasion and metastasis. Nat Med 1999; 5:803-9. [PMID: 10395326 DOI: 10.1038/10525] [Citation(s) in RCA: 394] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The endoglycosidase heparanase is an important in the degradation of the extracellular matrix by invading cells, notably metastatic tumor cells and migrating leukocytes. Here we report the cDNA sequence of the human platelet enzyme, which encodes a unique protein of 543 amino acids, and the identification of highly homologous sequences in activated mouse T cells and in a highly metastatic rat adenocarcinoma. Furthermore, the expression of heparanase mRNA in rat tumor cells correlates with their metastatic potential. Exhaustive studies have shown only one heparanase sequence, consistent with the idea that this enzyme is the dominant endoglucuronidase in mammalian tissues.
Collapse
|
150
|
Mandell LR, Kadota R, Freeman C, Douglass EC, Fontanesi J, Cohen ME, Kovnar E, Burger P, Sanford RA, Kepner J, Friedman H, Kun LE. There is no role for hyperfractionated radiotherapy in the management of children with newly diagnosed diffuse intrinsic brainstem tumors: results of a Pediatric Oncology Group phase III trial comparing conventional vs. hyperfractionated radiotherapy. Int J Radiat Oncol Biol Phys 1999; 43:959-64. [PMID: 10192340 DOI: 10.1016/s0360-3016(98)00501-x] [Citation(s) in RCA: 193] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
PURPOSE In June 1992, POG began accrual to a phase III study, POG-9239, designed to compare the time to disease progression, overall survival, and toxicities observed in children with newly diagnosed brainstem tumor treated with 100 mg/m2 of infusional cisplatin and randomized to either conventional vs. hyperfractionated radiotherapy. METHODS AND MATERIALS Patients eligible for study were those between 3 and 21 years of age with previously untreated tumors arising in the pons. Histologic confirmation of diagnosis was not mandatory, provided that the clinical and MRI scan findings were typical for a diffusely infiltrating pontine lesion. Treatment consisted of a six-week course of local field radiotherapy with either once a day treatment of 180 cGy per fraction to a total dose of 5400 cGy (arm 1) or a twice a day regimen of 117 cGy per fraction to a total dose of 7020 cGy (the second of the three hyperfractionated dose escalation levels of POG-8495) (arm 2). Because of previously reported poor results with conventional radiotherapy alone, cisplatin was included as a potential radiosensitizer in an attempt to improve progression-free and ultimate survival rates. Based on results of the phase I cisplatin dose escalation trial, POG-9139, 100 mg/m2 was chosen for this trial and was delivered by continuous infusion over a 120-hour period, beginning on the first day of radiotherapy and repeated during weeks 3 and 5. One hundred thirty eligible patients were treated on protocol, 66 on arm 1 and 64 on arm 2. RESULTS The results we report are from time of diagnosis through October 1997. For patients treated on arm 1, the median time to disease progression (defined as time to off study) was 6 months (range 2-15 months) and the median time to death 8.5 months (range 3-24 months); survival at 1 year was 30.9% and at 2 years, 7.1%. For patients treated on arm 2, the corresponding values were 5 months (range 1-12 months) and 8 months (range 1-23 months), with 1- and 2-year survival rates at 27.0% and 6.7%, respectively. Evaluation of response by MRI at 4 or 8 wks post treatment was available in 108 patients and revealed a complete response in 1 patient of each Rx arm, a partial response (> 50% decrease in size) in 18 patients of arm 1 and 15 patients of arm 2, minimal to no response (stable) in 25 patients of arm 1 and 23 patients of arm 2, and progressive disease in 13 patients of arm 1 and 12 patients of arm 2. The pattern of failure was local in all patients. Morbidity of treatment was similar in both Rx arms, with no significant toxicity (including hearing loss) reported. Autopsy was performed in 6 patients, and confirmed the presence of extensive residual tumor in these cases. CONCLUSION The major conclusion from this trial is that the hyperfractionated method of Rx 2 did not improve event-free survival (p = 0.96) nor did it improve survival (p = 0.65) over that of the conventional fractionation regimen of Rx 1, and that both treatments are associated with a poor disease-free and survival outcome.
Collapse
|