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Winn SR, Schmitt JM, Buck D, Hu Y, Grainger D, Hollinger JO. Tissue-engineered bone biomimetic to regenerate calvarial critical-sized defects in athymic rats. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 1999; 45:414-21. [PMID: 10321715 DOI: 10.1002/(sici)1097-4636(19990615)45:4<414::aid-jbm17>3.0.co;2-z] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
A tissue-engineered bone biomimetic device was developed to regenerate calvaria critical-sized defects (CSDs) in athymic rats. Well-documented evidence clearly confirms that left untreated, CSDs will not spontaneously regenerate bone. To accomplish regeneration, four candidate treatments were assessed: porous poly(D,L-lactide) and type I collagen (PLC), PLC and human osteoblast precursor cells (OPCs) at 2 x 10(5) (PLC/OPCs), PLC and 50 microg of recombinant human bone morphogenetic protein-2 (PLC/rhBMP-2), and PLC/OPCs/rhBMP-2 (the bone biomimetic device). The hypotheses for this study were PLC/OPCs/rhBMP-2 would promote more new bone formation in CSDs than the other treatments and the amount of bone formation would be time dependent. To test the hypotheses, outcomes from treatments were measured at 2 and 4 weeks postoperatively by radiomorphometry for percent radiopacity and by histomorphometry for square millimeters of new bone formation. Data were analyzed by analysis of variance and Fisher's protected least significant difference for multiple comparisons with p < or = 0.05. At 2 and 4 weeks, radiomorphometric data revealed PLC/rhBMP-2 and PLC/OPCs/rhBMP-2 promoted significantly more radiopacity than either PLC or PLC/OPCs. Histomorphometry data at 2 and 4 weeks indicated significantly more new bone formation for PLC/rhBMP-2, PLC/OPCs/rhBMP-2, and PLC/OPCs compared to PLC. By 4 weeks, PLC/OPCs/rhBMP-2 and PLC/rhBMP-2 had regenerated the CSDs with more new bone than the other treatments; the quantity of bone at 4 weeks for these treatments was greater than at 2 weeks.
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Hollinger JO, Schmitt JM, Hwang K, Soleymani P, Buck D. Impact of nicotine on bone healing. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 1999; 45:294-301. [PMID: 10321701 DOI: 10.1002/(sici)1097-4636(19990615)45:4<294::aid-jbm3>3.0.co;2-1] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A limited number of experimental animal studies and in vitro data confirm that nicotine impairs bone healing, diminishes osteoblast function, causes autogenous bone graft morbidity, and decreases graft biomechanical properties. Therefore, our long-term goal is to develop an effective therapy to reverse the adverse impact of nicotine from tobacco products. However, before accomplishing this goal, we had to develop an animal model. Our hypotheses were nicotine administration preceding and following autogenous bone grafting adversely affected autograft incorporation and depressed donor site healing in a characterized animal wound model. Hypothesis testing was accomplished in bilateral, 4-mm diameter parietal bone defects prepared in 60 Long-Evans rats (male, 35-day-old). A 4-mm diameter disk of donor bone was removed from the left parietal bone and placed in the contralateral defect. The donor site served as a spontaneously healing bone wound. The rats were partitioned equally among three doses of nicotine administered orally in the drinking water (12.5, 25, and 50 mg/L). For each dose, the duration and sequence of nicotine treatment followed four courses, including no nicotine and designated combinations of nicotine administration and abatement prior to and following osseous surgery. Experimental sites were recovered on 14 and 28 days postsurgery, responses quantitated, and data analyzed by analysis of variance and post hoc statistics (p < or = 0.05). We developed a convenient and effective osseous model, and the results validated our hypothesis that nicotine negatively impacts on bone healing.
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Jacoby A, Baker GA, Steen N, Buck D. The SF-36 as a health status measure for epilepsy: a psychometric assessment. Qual Life Res 1999; 8:351-64. [PMID: 10472168 DOI: 10.1023/a:1008902728574] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A considerable literature is now available on the applications and psychometric properties of the MOS SF-36 Health Survey. In epilepsy, the SF-36 has been used as a health status measure in its own right and as the stem for two condition-specific measures. This paper replicates for epilepsy previous work to support use of the SF-36 across a range of clinical conditions. Data were obtained from a European-wide descriptive study of quality of life of adults with epilepsy; analysis of responses on the SF-36 is based on 4,929 subjects in eight countries. Missing value rates for all SF-36 items were low; percentages for whom complete information available for subscales ranged from 95.7% to 98.6%. All subscales passed tests for item-internal consistency and item-discriminant validity. Reliability coefficients exceeded the standard recommended for group comparisons across all subscales. Floor effects were negligible for all but the two role disability subscales; there were substantial ceiling effects for five of the SF-36 subscales. We conclude that the SF-36 is a valid and reliable health status measure for descriptive studies of people with epilepsy, but ceiling effects may limit its usefulness as an outcome measure in the assessment of new treatments.
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McAllister BS, Margolin MD, Cogan AG, Buck D, Hollinger JO, Lynch SE. Eighteen-month radiographic and histologic evaluation of sinus grafting with anorganic bovine bone in the chimpanzee. Int J Oral Maxillofac Implants 1999; 14:361-8. [PMID: 10379109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Abstract
Maxillary sinus grafting procedures are currently the treatment of choice when the alveolar crest of the posterior maxilla is in close approximation to the maxillary sinus. The short-term histologic and radiographic healing following sinus grafting with natural bone mineral (Bio-Oss) in the chimpanzee has been evaluated. We have previously shown by histomorphometric and radiographic analysis that the percentage of vital bone area, the vertical height, and the density of new bone in the maxillary sinus was significantly greater with anorganic bovine bone compared to bovine Type I collagen matrix. The purpose of this in vivo study was to determine the bone mineral density (BMD) of the sinus grafts, the vertical height stability, the vital bone area, and the extent of anorganic bovine bone replacement 18 months postoperatively in 4 maxillary sinuses from 4 different animals. Radiographic analysis of computed tomographic scans taken at 1.5 years revealed an average BMD of 658 mg/mL, which was not significantly different from the values found at 6.5 months. The radiographic vertical height was maintained between the 6.5- and 18-month time points. On average, the grafts were found to have a height of 14 mm. Lateral wall biopsy specimens at 7.5 months were compared to those at 18 months. With the anorganic bovine bone treatment, the percentage of vital bone area increased from 62 +/- 3% to 70 +/- 7% and the percentage of natural bone mineral area decreased from 19 +/- 14% to 6 +/- 3%. The bovine Type I collagen matrix vital bone percentage at 7.5 months was 34 +/- 21%. These results demonstrate that sinus grafting with anorganic bovine bone maintains radiographic evidence of density and height stability of 1.5 years. In addition, histologic evidence supports the hypothesis that anorganic bovine bone is replaced by vital bone.
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McNamee P, Gregson BA, Buck D, Bamford CH, Bond J, Wright K. Costs of formal care for frail older people in England: the resource implications study of the MRC cognitive function and ageing study (RIS MRC CFAS). Soc Sci Med 1999; 48:331-41. [PMID: 10077281 DOI: 10.1016/s0277-9536(98)00351-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The aim of this paper is to quantify service use and costs of supporting frail older people at home in the community, using data collected in a longitudinal multicentre stratified randomised study for 1055 mentally frail, physically frail, and mentally and physically frail subjects. Average costs per person per week were found to total 64.45 Pounds Sterling, with a small number of services accounting for a large proportion of the total costs. The level of services offered by the nonstatutory voluntary and private sectors was found to be small. To highlight issues for policy makers, the extent of cost variations between a number of different subgroups were calculated. These bivariate analyses revealed substantial variation in costs, especially according to household structure, type of frailty, whether admission to continuing care accommodation occurred and survival. Multiple regression analysis demonstrated that 26% of the variation in log average weekly costs could be explained by a number of socio-demographic and health status variables. A particularly close relationship was observed between costs and whether admission to continuing care accommodation occurred, highlighting a need for policy-makers to examine the nature and scale of provision of alternative community based care packages. The results demonstrate that descriptive cost data such as those presented can provide information useful to the planning process, enabling more informed choices to be made over the provision of services for particular groups of people.
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Buck D, McNaughton LR. Changing the number of submaximal exercise bouts effects calculation of MAOD. Int J Sports Med 1999; 20:28-33. [PMID: 10090458 DOI: 10.1055/s-2007-971087] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The aim of this present study was to evaluate the effect of the number of submaximal exercise bouts used to construct the power-VO2 regression, on calculations of MAOD through the sequential and systematic removal of the highest and lowest submaximal VO2 values from the standard ten point regression line. Eight trained male cyclists participated in this study. The mean (+/- SD) age, height, weight and VO2max for the subjects were 25+/-7 yr, 178.2+/-3.0 cm, 69.9+/-4.9 kg and 57.5+/-6.9 ml x kg(-1) x min(-1). After VO2max testing each subject undertook ten submaximal exercise bouts at between 30% and 90% VO2max and one supramaximal bout calculated to elicit 100% VO2max. Expired gases were measured via open circuit spirometry. The mean power output of the supramaximal bout was 336.5+/-442.5 W and the mean duration was 269.4+/-42.9 s. The correlation coefficients ranged from 0.981 to 0.996 while the MAOD values ranged from 29.6+/-15.7 ml O2 eq x kg(-1) to 61.3+/-44.7 ml O2 eq x kg(-1). When compared to the standard ten points, as a percentage difference, this difference ranged from 4.1+/-3.6% to 83.7+/-54.9%. The main finding of this study is that inaccuracies occur in the measurement of MAOD when less than ten points are used in the calculation. Further study is required for the development of a standardised protocol for the accurate, valid and reliable measurement of MAOD.
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McNamee P, Gregson BA, Wright K, Buck D, Bamford CH, Bond J. Estimation of a multiproduct cost function for physically frail older people. HEALTH ECONOMICS 1998; 7:701-710. [PMID: 9890331 DOI: 10.1002/(sici)1099-1050(199812)7:8<701::aid-hec382>3.0.co;2-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Using the theory of multiproduct cost functions, this paper derives a cost function for physically frail older people living in private households, based on data collected between 1991 and 1995, for 472 subjects aged 65 years of age or over in four areas of England. The main characteristic of the cost function is that output categories are classified in terms of movements between different health states. These were measured by changes in activities of daily living (ADL) over 2 years, with 'low' ADL representing better functional ability than 'high' ADL. Empirical application of the approach, using four states defined in terms of worsening progression (stable low ADL; deteriorated or improved ADL; stable high ADL; deceased), indicated more favourable states were associated with lower costs. Multivariate analysis showed that the derived states were significantly related to costs which, when combined with variables indicating presence of particular chronic health conditions (diabetes or previous stroke), admission to continuing care accommodation and household structure, explained one-fifth of the variation in log average costs per week. Variables such as age, sex, carer input, social networks and level of cognitive functioning had no independent impact on costs. These findings could be used as a starting point for those interested in predicting the cost implications associated with the ageing population.
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Burgess E, Hollinger J, Bennett S, Schmitt J, Buck D, Shannon R, Joh SP, Choi J, Mustoe T, Lin X, Skalla W, Connors D, Christoforou C, Gruskin E. Charged beads enhance cutaneous wound healing in rhesus non-human primates. Plast Reconstr Surg 1998; 102:2395-403. [PMID: 9858175 DOI: 10.1097/00006534-199812000-00019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Enhanced cutaneous wound healing by positively charged cross-linked diethylaminoethyl dextran beads (CLDD) was studied in a standardized incisional wound model in 20 adult and 20 geriatric Macaca mulatta (rhesus) partitioned equally over five time periods. Physiologic saline served as a control. Soft-tissue linear incisions were prepared between and 1 cm inferior to the scapulae. There were four incisions per rhesus; each incision was 1.5 cm long with 1 cm of undisturbed tissue between incisions, and both the experimental CLDD and physiologic saline treatments were administered to each rhesus. The incision treatments were either CLDD and soft-tissue closure with 4-0 BioSyn sutures or sterile physiologic saline and closure with 4-0 BioSyn sutures. The hypothesis was CLDD would enhance cutaneous wound repair. Verification of the hypothesis consisted of clinical examinations and histologic and tensiometric evaluations on biopsy specimens at 10 and 15 days, whereas 5-day and 2- and 4-month groups were assessed clinically and biopsy specimens were assessed histologically. The clinical course of healing for all groups was unremarkable. At 10 days, incisions in adult rhesus treated with CLDD had a 30-percent greater tensile strength compared with the physiologic saline-treated incisions (p = 0.01), whereas for geriatric rhesus, the CLDD treatment proved to be 15 percent greater in tensile strength compared with the physiologic saline cohort (p = 0.11). By day 15, incisions in adult rhesus were 26 percent stronger than the saline treatment group (p = 0.07), and the difference was 36 percent (p = 0.02) for the geriatric rhesus. From 5 through 15 days, histologic observations revealed a gradual decrease in quantity and integrity of CLDD, with no remnants of CLDD at either 2 or 4 months. Macrophages and multinucleated giant cells were localized in the dermis and were associated with the CLDD. These cells decreased commensurately with the decrease of CLDD beads. The data suggest that CLDD can enhance significantly the tensile properties of healing cutaneous wounds in both adult and geriatric rhesus. Moreover, if the wound healing is enhanced in geriatric patients, this finding may be clinically germane to conditions where wound healing is compromised, such as in diabetics and patients on steroids.
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de Wynter EA, Buck D, Hart C, Heywood R, Coutinho LH, Clayton A, Rafferty JA, Burt D, Guenechea G, Bueren JA, Gagen D, Fairbairn LJ, Lord BI, Testa NG. CD34+AC133+ cells isolated from cord blood are highly enriched in long-term culture-initiating cells, NOD/SCID-repopulating cells and dendritic cell progenitors. Stem Cells 1998; 16:387-96. [PMID: 9831864 DOI: 10.1002/stem.160387] [Citation(s) in RCA: 166] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The AC133 antigen is a novel antigen selectively expressed on a subset of CD34+ cells in human fetal liver, bone marrow, and blood as demonstrated by flow cytometric analyses. In this study, we have further assessed the expression of AC133 on CD34+ cells in hemopoietic samples and found that there was a highly significant difference between normal bone marrow and cord blood versus aphereses (p <0.0001) but not between bone marrow and cord blood. Most of the clonogenic cells (67%) were contained in the CD34+AC133+ fraction. Compared with cultures of the CD34+AC133- cells, generation of progenitor cells in long-term culture on bone marrow stroma was consistently 10- to 100-fold higher in cultures initiated with CD34+AC133+ cells and was maintained for the 8-10 weeks of culture. Only the CD34+AC133+ cells were capable of repopulating NOD/SCID mice. Human cells were detectable as early as day 20, with increased levels (67%) apparent 40 days post-transplantation. Five thousand CD34+AC133+ cells engrafted about 20% of the mice, while no engraftment was observed in animals transplanted with up to 1.2 x 10(5) CD34+AC133- cells. The CD34+AC133+ population was also enriched (seven-fold) in dendritic cell precursors, and the dendritic cells generated were functionally active in a mixed lymphocyte reaction assay. AC133+ cells should be useful in the study of cellular and molecular mechanisms regulating primitive hemopoietic cells.
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Malekzadeh R, Hollinger JO, Buck D, Adams DF, McAllister BS. Isolation of human osteoblast-like cells and in vitro amplification for tissue engineering. J Periodontol 1998; 69:1256-62. [PMID: 9848535 DOI: 10.1902/jop.1998.69.11.1256] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
As the field of dental implants continues to grow at a rapid rate so does our quest to find new techniques to enhance bone grafting. Tissue engineering is an exciting new technique in bone grafting. Therefore, the purposes of this study were to develop a simple, reproducible method to isolate human osteoblast-like cells (HOBs) and to evaluate in vitro cell proliferation within 2 different 3-dimensional (3-D) constructs targeted for tissue engineering applications. Ultimately, HOBs that have been amplified within 3-D constructs may be employed for bone regeneration techniques, such as onlay and sinus grafting prior to implant placement. Our cell isolation protocol employed human fetal calvaria tissue sequentially digested with trypsin and collagenase. The HOB cells from only the third and fourth digests were obtained, cultured and evaluated within the constructs. An osteoblast-like phenotype was in part verified for these HOB cells by demonstrating a significantly higher alkaline phosphatase activity than for human gingival fibroblasts, and a comparable level to the osteoblast cell line MG-63. The HOB cells were cultured within either poly (D,L-lactide) (PLA) or a fused fiber ceramic and evaluated for the ability to support in vitro HOB amplification. HOB proliferation was validated by scanning electron microscopy, identifying cells throughout the 3-D constructs. Continuous cell viability was demonstrated for the duration of the 33-day evaluation period and the extent of cell amplification reached approximately 20 times the seeding density. The in vitro amplification results further indicate that tissue engineering strategies with either the PLA or fused fiber construct may be suitable for bone regeneration therapy for dental implants.
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Niggemann B, Buck D, Michael T, Wahn U. Latex provocation tests in patients with spina bifida: who is at risk of becoming symptomatic? J Allergy Clin Immunol 1998; 102:665-70. [PMID: 9802377 DOI: 10.1016/s0091-6749(98)70285-4] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Although there is accepted information on the prevalence rates of sensitization to latex in patients with spina bifida, little is known about the clinical relevance of this sensitization. METHODS We performed provocation tests with latex gloves in 159 patients with spina bifida (median age, 10 years). RESULTS Eighty-eight patients (55.3%) were sensitized to latex in terms of a positive skin prick test response, specific IgE to latex in serum, or both. Fifty-five patients (34.6% of all patients or 62.5% of latex-sensitized patients) showed clinical symptoms on provocation. Specific IgE to latex was significantly higher in patients with a positive provocation test response (P <.0001). The total number of operations and degree of sensitization showed a significant correlation. More than 8 operations significantly increased the risk of sensitization (P <.0001), and more than 9 operations increased the risk of allergy to latex (P <.0001). One hundred seventeen (75%) patients had a ventricular shunt system. Specific IgE in these patients was significantly higher than in patients without (P <.0001), and the odds ratio for the existence of a shunt system in terms of a positive provocation was 3.9. Patients with a shunt system were significantly more often sensitized and had positive provocation results (P <.0001). Seventy-two patients (45.3%) were classified as atopic; they were significantly more often sensitized and clinically symptomatic (P <.0001), and the odds ratio for having a positive provocation response was 3.2 for atopic subjects. History of symptoms on contact with material containing latex had a sensitivity of 53.7% and specificity of 94.2%. CONCLUSIONS Our results indicate that an atopic disposition, number of operations, and presence of a shunt system increase the risk of becoming not only sensitized but also allergic to latex. Our results strongly support the necessity that patients with spina bifida as a high-risk group for latex allergy should remain latex-free from the first day of life.
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Schmitt JM, Buck D, Bennett S, Skalla W, Christoforou C, Buechter D, Gruskin E, Hollinger J. Assessment of an experimental bone wax polymer plus TGF-beta 1 implanted into calvarial defects. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 1998; 41:584-92. [PMID: 9697031 DOI: 10.1002/(sici)1097-4636(19980915)41:4<584::aid-jbm10>3.0.co;2-f] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The study reported describes an experimental biodegradable polymer ceramic composite with wax-like handling properties that was combined with 2.0 micrograms of recombinant human transforming growth factor beta (rhTGF-beta(1)). The polymer/rhTGF-beta(1) combination was introduced into standard-sized calvarial defects in rabbits to evaluate biodegradability, biocompatibility, hemostasis control, and bone promotion. The experimental wound model was a standard-size circular calvarial defect 8 mm in diameter. The experimental design included 24 skeletally mature New Zealand white rabbits divided evenly between two time periods (6 and 12 weeks) and among three experimental treatments (untreated defects and defects treated with polymer with or without rhTGF-beta(1)). Evaluations consisted of clinical examinations, standarized radiography, radiomorphometry, as well as histology and histomorphometry. Data were analyzed by an Analysis of Variance (ANOVA) and Fisher's Protected Least Significant Difference test at each time period (level of significance p < or = 0.05). Radiomorphometry data indicated that standard-sized defects treated with the wax-like polymer alone and the polymer plus 2.0 micrograms of TGF-beta(1) were significantly more radiopaque than control sites at both 6 and 12 weeks. Histomorphometric data revealed the amount of new bone was significantly greater at 6 weeks in the polymer plus 2.0 micrograms of TGF-beta(1) and in the control group than in the polymer alone. Moreover, at 12 weeks, there was significantly more new bone in the control than in either the polymer alone or the polymer plus 2.0 micrograms of TGF-beta(1). We speculate the incomplete biodegradation of the polymer ceramic composite contributed to the radiopacity and may have retarded osseous regeneration. It is important that the bone wax-like polymer material was biocompatible and acted as a hemostatic agent.
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Buck D, Smith K. The distribution of community psychiatric nurses in England: are they where they should be? J Adv Nurs 1998; 28:508-16. [PMID: 9756217 DOI: 10.1046/j.1365-2648.1998.00699.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Given the substantial increase in the numbers of community psychiatric nurses (CPNs) in England in the last 15 years this paper asks the question: is CPN activity where it should be? In-other words is activity distributed around the country according to need? Various indicators of need are suggested including population age structure, deprivation indices and suicide rates. We find no evidence -- based on information from scatterplots, Spearman correlations and more innovative measures of inequality -- that CPNs are distributed according to need. If this is confirmed by further research it is cause for alarm -- CPNs should be where they are most needed.
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Margolin MD, Cogan AG, Taylor M, Buck D, McAllister TN, Toth C, McAllister BS. Maxillary sinus augmentation in the non-human primate: a comparative radiographic and histologic study between recombinant human osteogenic protein-1 and natural bone mineral. J Periodontol 1998; 69:911-9. [PMID: 9736374 DOI: 10.1902/jop.1998.69.8.911] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The posterior maxilla has traditionally been one of the most difficult areas to successfully place dental implants due to poor bone quality and close approximation to the maxillary sinus. Sinus augmentation procedures have become a viable means of assuring adequate bone for the placement of dental implants in this area. However, with the techniques currently employed, a considerable variation in the quality of bone attained with the sinus augmentation procedure exists. The purpose of this in vivo study was to evaluate the healing response and bone formation stimulated by 3 doses of recombinant human osteogenic protein-1 (rhOP-1), 0.25, 0.6, and 2.5 mg OP-1 per gram of collagen matrix; natural bone mineral; or collagen matrix alone (control) placed in the maxillary sinus of adult chimpanzees. Results were assessed using clinical, histologic, and radiographic techniques. Radiographic analysis of the computed tomography scans taken at 1 week, and 2.5, 4.5, and 6.5 months revealed a more rapid mineralization with the 2.5 mg OP-1/g collagen matrix and natural bone mineral treatment groups. The incremental bone mineral density (BMD) increase for these 2 treatments from 1 week to 2.5 months was over 2.5 times the increase found with the collagen matrix alone; these 2 treatments also had a higher BMD at the most superior slices evaluated when compared to the other 3 groups. Biopsy specimens were taken at 3.5, 5.5, and 7.5 months and for all 5 treatment groups bone formation was observed at all time points in the majority of the specimens. At 7.5 months the 2.5 and 0.6 mg OP-1/g collagen matrix treatment groups had an increase in the percent bone area when compared to the matrix alone control. In conclusion, these results demonstrate that sinus augmentation with natural bone mineral or 2.5 mg OP-1/g collagen matrix induce comparable radiographic and histologic evidence of bone formation and that both of these treatments performed superior to the control group of collagen matrix alone based upon all methods of evaluation.
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Jacoby A, Buck D, Baker G, McNamee P, Graham-Jones S, Chadwick D. Uptake and costs of care for epilepsy: findings from a U.K. regional study. Epilepsia 1998; 39:776-86. [PMID: 9670907 DOI: 10.1111/j.1528-1157.1998.tb01164.x] [Citation(s) in RCA: 154] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE Epilepsy is a common neurological condition, with significant resource implications for the health services, but few studies to date have examined the uptake and costs of care for this condition. As part of a large prevalence study of epilepsy conducted in one U.K. Health Region, we investigated both direct and indirect costs of epilepsy care and measured and valued the direct costs. METHODS Data about service use were obtained from primary physician records and patient questionnaires. Unit costs for each item of resource use were generated from several sources. RESULTS The greatest direct health care cost is that of hospital-based care. Pharmaceutical services also represent a significant element of the cost of epilepsy, the financial costs of prescribing newly developed antiepileptic drugs (AEDs) being large relative to those of the older drugs; therefore, the benefits derived from their use must be carefully assessed. The importance of good seizure control is amply illustrated by the findings about the differential costs associated with epilepsy of varying severity. The direct costs of caring for people with poorly controlled epilepsy are significant, with more than half the total cost of epilepsy care accounted for by patients with frequent seizures even though this group represented only a quarter of all patients in the present study. CONCLUSIONS Our data emphasize the importance of optimizing seizure control as a means of reducing the costs of epilepsy, not only to the person with the condition, but also to society.
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Miraglia S, Godfrey W, Buck D. A response to AC133 hematopoietic stem cell antigen: human homologue of mouse kidney prominin or distinct member of a novel protein family? Blood 1998; 91:4390-1. [PMID: 9596691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
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Buck D. Health education and promotion spending in England: a note on the potential utility of the Health Service Indicators dataset. HEALTH EDUCATION RESEARCH 1998; 13:133-138. [PMID: 10178335 DOI: 10.1093/her/13.1.133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Health promotion and education (HPE) needs to be evaluated on a national scale. This note draws attention to the existence, possible uses and pitfalls of a little known dataset which provides information on English district health authorities' HPE expenditure for the first time. Despite its problems, cautious uses of this data has the potential to significantly increase the knowledge and understanding of local level HPE in England.
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Buck D. Debate. The contribution of health promotion to meeting health targets: questions of measurement, attribution and responsibility. Health Promot Int 1997. [DOI: 10.1093/heapro/12.3.239] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Corbett SJ, Tomlinson IM, Sonnhammer EL, Buck D, Winter G. Sequence of the human immunoglobulin diversity (D) segment locus: a systematic analysis provides no evidence for the use of DIR segments, inverted D segments, "minor" D segments or D-D recombination. J Mol Biol 1997; 270:587-97. [PMID: 9245589 DOI: 10.1006/jmbi.1997.1141] [Citation(s) in RCA: 240] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We have determined the complete nucleotide sequence of the human immunoglobulin D segment locus on chromosome 14q32.3 and identified a total of 27 D segments, of which nine are new. Comparison with a database of rearranged heavy chain sequences indicates that the human antibody repertoire is created by VDJ recombination involving 25 of these 27 D segments, extensive processing at the V-D and D-J junctions and use of multiple reading frames. We could find no evidence for the proposed use of DIR segments, inverted D segments, "minor" D segments or D-D recombination. Conventional VDJ recombination, which obeys the 12/23 rule, is therefore sufficient to explain the wealth of lengths and sequences for the third hypervariable loop of human heavy chains.
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Buck D, Gregson BA, Bamford CH, McNamee P, Farrow GN, Bond J, Wright K. Psychological distress among informal supporters of frail older people at home and in institutions. The Resource Implications Study Group of the MRC Cognitive Function and Ageing Study. Int J Geriatr Psychiatry 1997; 12:737-44. [PMID: 9251936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE Investigate presence of psychiatric morbidity in informal carers using 30-item General Health Questionnaire (GHQ) and examine which factors best predict psychiatric morbidity. DESIGN Two-year longitudinal, panel survey of informal supporters of frail elderly subjects, using semi-structured interview schedules. Subjects were those defined as frail after screening stratified random sample of people aged 65 or over. SETTING Informal supporters of frail elderly subjects residing in private households or residential or nursing homes in four UK districts. RESPONDENTS 623 informal supporters of subjects living at home, 129 regular visitors of those in long-term care. MEASURE 30-item GHQ (cross-sectional analysis). RESULTS Stepwise multiple regression indicated main predictors of high GHQ scores in key supporters were: subjects had at least three problems of behaviour (b = 1.56, 95% CI 1.25-1.94); supporters had to alter working hours (b = 1.70, 95% CI 1.15-2.51); supporters were female (b =1.26, 95% CI 1.06-1.50). The following variables predicted low GHQ scores: supporters able to leave subject all day (b = 0.71, 95% CI 0.64-0.80); subjects never wandered (b = 0.78, 95% CI 0.62-0.99); supporters were 'other relatives' or friends of subject (b = 0.74, 95% CI 0.59-0.91). For visitors, spouses were most likely to have high GHQ scores (b = 2.46, 95% CI 1.32-4.57). CONCLUSIONS Results suggest the need for greater collaboration between formal and informal care. Little work has been carried out to ascertain which interventions are most effective in alleviating carer stress: a series of randomized controlled trials to determine long-term effectiveness of various interventions for different groups of carers is required.
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Buck D, Jacoby A, Baker GA, Chadwick DW. Factors influencing compliance with antiepileptic drug regimes. Seizure 1997; 6:87-93. [PMID: 9153719 DOI: 10.1016/s1059-1311(97)80060-x] [Citation(s) in RCA: 144] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Failure to comply with drug regimes is prevalent amongst patients with epilepsy and the consequence of this is often an increased risk of further seizures. This paper describes the level of, and influences upon, non-compliance with antiepileptic drug (AED) treatment. A postal questionnaire was sent to an unselected, community-based population of patients with epilepsy. This instrument included questions about patients' AED treatment, any related side-effects, and AED-taking behaviour. Univariate analysis showed that factors associated with compliance were patient age, how important patients felt it was to take drugs as prescribed, whether patients reported feelings of stigma, whether on mono- or polytherapy, whether they were experiencing any side-effects because of AEDs, whether patients had a regular arrangement to see their GP about epilepsy and how easy they found their GP to talk to. Multivariate analysis showed that the strongest predictors of non-compliance were feeling it was not very or not at all important to take AEDs as prescribed, being a teenager, being aged under 60 and being on monotherapy. Further implementation of educational programmes for people with epilepsy would help to improve levels of compliance thereby reducing the risk of unnecessary seizures.
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97
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Abstract
PURPOSE The increased risk of mortality among people with epilepsy is well documented; people with epilepsy are more likely than the general population to die as a result of an accident. Data about incidence of nonfatal accidents and associated factors are not so readily available, even though such accidents are more common than fatal injuries. We report the proportion of people who sustain various injuries during a seizure and the key variables predicting injury. METHODS Questionnaires were mailed to an unselected, community-based population of patients with epilepsy. The questionnaire included clinical and demographic details, previously validated scales of psychosocial well-being, and questions about seizure-related injuries. RESULTS Of patients who had had at least one seizure during the previous year, 24% sustained at least one head injury, 16% sustained a burn or scald, 10% a dental injury, and 6% some other fracture. Seizure type, seizure severity, and seizure frequency were key predictors of having sustained at least one of these four seizure-related injuries. Key predictors of burn/scald were seizure severity, seizure frequency and sex; those of head injury were seizure severity and type; that of dental injury was seizure severity; and those of some other fracture were seizure severity, duration of epilepsy, and three or more drug-related adverse effects. CONCLUSIONS These data help identify significant risk factors associated with seizure-related injuries and so facilitate sensible patient counseling about how the risks of such injuries can be minimized.
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Abstract
PURPOSE To study the impact of epilepsy and its treatment on people with epilepsy in Europe. We therefore aimed to collect data from as many countries as possible. METHODS Clinical and demographic details and information about psychosocial functioning was collected using self-completed questionnaires mailed to members of epilepsy support groups. RESULTS Quality of life data was collected from >5,000 patients living in 15 countries in Europe. Over a third of all respondents had frequent seizures, and a fifth believed that their seizures were not well enough controlled by antiepileptic medication. Reported levels of side effects from medication were high. A significant number of respondents reported changing their medication because of side effects or poor control. Respondents reported that epilepsy and its treatment had a significant impact on a number of different aspects of their daily lives. Half of all respondents felt stigmatised by their epilepsy. There were significant differences by seizure type and frequency in the way respondents scored on measures of the perceived impact of their condition, the stigma associated with it and their health status as measured by a generic scale, the SF36. CONCLUSIONS This study confirms the findings of previous smaller-scale studies that reducing side effects and achieving better control of seizures are key to improving the quality of life of people with epilepsy, as is reducing the stigma and handicap associated with it.
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Buck D, Godfrey C, Killoran A, Tolley K. Reducing the burden of coronary heart disease: health promotion, its effectiveness and cost. HEALTH EDUCATION RESEARCH 1996; 11:487-499. [PMID: 10163957 DOI: 10.1093/her/11.4.487] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Coronary heart disease (CHD) is one of five key areas identified in the Health of the Nation white paper produced by the Department of Health in 1992. The main CHD targets are to reduce death rates from CHD by at least 40% in people below 65 and 30% in those between 65 and 74 by the year 2000, respectively. Improvements in treatment and rehabilitation are expected to contribute to reducing the burden of CHD; however, in the long term, prevention is believed to hold the greatest potential. CHD health promotion therefore has a big role to play in securing the Health of the Nation targets. In contrast to treatment interventions, however, little is known about the effectiveness or cost-effectiveness of health promotion. The purpose of this article is two-fold. Its main aim is to illustrate the potential of health promotion in reducing the health burden of CHD to the turn of the century and beyond for a representative health purchaser. This is achieved with the use of an epidemiological model, Prevent, developed in the Netherlands to simulate the health outcomes associated with health promotion and prevention. A subsidiary aim is to present tentative information about the relative costs associated with different health promotion options.
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Buck D, Jacoby A, Baker GA, Graham-Jones S, Chadwick DW. Patients' experiences of and satisfaction with care for their epilepsy. Epilepsia 1996; 37:841-9. [PMID: 8814096 DOI: 10.1111/j.1528-1157.1996.tb00036.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
PURPOSE To determine condition-specific satisfaction with care, we studied patients' experience of general practitioner (primary physician) and hospital clinic care for their epilepsy and their views about the provision of information concerning the management of their condition. METHODS A postal questionnaire was sent to an unselected, community-based population of patients with epilepsy. In addition to clinical and demographic details and previously validated scales of psychosocial well-being, the instrument contained a series of questions about patients' experiences and views of the care they received for epilepsy from both general practice and the hospital services. RESULTS Doctors' interpersonal skills were the most influential factors affecting both patient satisfaction overall and the likelihood that doctors might discuss with patients certain clinical and social issues surrounding the management of the patient's condition. A sizable proportion of patients reported that they received insufficient information about epilepsy, both from hospital doctors and general practitioners. CONCLUSIONS Patients with epilepsy place great importance on having a doctor who is approachable, communicative, and knowledgeable and on receiving adequate information about their condition. Clinicians may need to be made more aware of the importance of accessibility and sensitivity to the nonclinical needs of their patients. Such easily implemented changes in the delivery of care would improve services in the United Kingdom for people with epilepsy.
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