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Thomas MRM, DeFriend D, Edwards A, Jackson SA. Portal vein thrombosis and multiple hepatic abscesses diagnosed by percutaneous transhepatic cholangiography (PTC). Clin Radiol 2002; 57:73-4. [PMID: 11798208 DOI: 10.1053/crad.2001.0770] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Jackson SA, Burke GL, Thach C, Cushman M, Ives D, Powe N, Manolio TA. Incidence and predictors of coronary heart disease among older African Americans--the Cardiovascular Health Study. J Natl Med Assoc 2001; 93:423-9. [PMID: 11730114 PMCID: PMC2594007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Although coronary heart disease (CHD) is the leading cause of death and morbidity in older African Americans, relatively little is known about the incidence and predictors of CHD in this population. This study was undertaken to determine the incidence and predictors of CHD in African-American men and women aged 65 years and older. The participants in this study included a total of 924 African-American men and women aged 65 years of age and older who participated in the Cardiovascular Health Study (CHS). The overall CHD incidence was 26.6 per 1,000 person-years of risk. Rates were higher in men than women (35.3 vs. 21.6) and in those 75 years or older than in those less than 75 years (31.3 vs. 24.5). In multivariate analysis, factors associated with higher risk of incident disease were male gender [relative risk (RR) = 1.8, 95% confidence interval (CI) = 1.1, 2.7], diabetes mellitus (RR = 1.9, 95% CI = 1.2, 2.9), total cholesterol (RR for 40 mg/dL increment = 1.3, 95% CI = 1.0, 1.5), and low (i.e., <0.9) ankle-arm index (RR = 2.1, 95% CI = 1.3, 3.4) after adjusting for age. Within this cohort of older African Americans, male gender, diabetes mellitus, total cholesterol, and low ankle-arm index and were independently predictive of incident events. These results suggest that the ankle-arm index, a measure of advanced atherosclerosis, should be further evaluated for its efficacy in identifying older African Americans at risk for incident clinical events.
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Prior JC, Kirkland SA, Joseph L, Kreiger N, Murray TM, Hanley DA, Adachi JD, Vigna YM, Berger C, Blondeau L, Jackson SA, Tenenhouse A. Oral contraceptive use and bone mineral density in premenopausal women: cross-sectional, population-based data from the Canadian Multicentre Osteoporosis Study. CMAJ 2001; 165:1023-9. [PMID: 11699697 PMCID: PMC81536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023] Open
Abstract
BACKGROUND Positive and negative effects on bone mineral density (BMD) have been described as a result of the premenopausal use of oral contraceptives (OCs); increased fracture rates have also been reported. This study assessed the relation between OC use and BMD in a population-based, 9-centre, national sample of women aged 25-45 years. METHODS Premenopausal women who had been enrolled in the Canadian Multicentre Osteoporosis Study were classified as having ever been OC users (> or = 3 months) or as having never been OC users (0 to < 3 months). Data were obtained through extensive questionnaires and measuring of participants' weight, height and the BMD of lumbar vertebrae and the proximal femur. RESULTS Of the sample of 524 women, whose mean age was 36.3 (standard deviation [SD] 5.9) years, 454 had used OCs; their mean age when they started using OCs was 19.8 (SD 3.5) years and the mean duration of use was 6.8 (SD 4.8) years. Women who had ever and those who had never used OCs showed no differences in age, age at menarche, parity, current calcium intake, exercise, body mass index (BMI), education, past irregular cycles or amenorrhea. OC users reported more alcohol and cigarette use and more use of medications to create regular cycles. Mean BMD values (adjusted for age, BMI and height) were 0.02-0.04 g/cm2 (that is, 2.3%-3.7%) lower in OC users, and were significantly lower in the spine and trochanter. The BMD of the spine in OC users was 1.03 (SD 0.12) g/cm2 versus 1.07 (SD 0.12) g/cm2 (95% confidence interval [CI] of difference -0.07 to -0.001) in those who had never used OCs. BMD was neither related to the duration of OC use nor to gynecological age at first use. Current and past users had similar BMD values. INTERPRETATION National, population-based data show lower BMD values for the trochanter and spine in premenopausal women who have used OCs compared with those who have never used OCs.
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Jackson SA, Piper I, Dunn L, Leffler C, Daley M. Assessment of the variation in cerebrovascular reactivity in head injured patients. ACTA NEUROCHIRURGICA. SUPPLEMENT 2001; 76:445-9. [PMID: 11450064 DOI: 10.1007/978-3-7091-6346-7_92] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Several indices have been reported which correlate with autoregulatory function [2, 3]. However, before critical thresholds for targeting therapy can be defined, a better understanding of the inherent variability of cerebrovascular reactivity as measured by these indices is required. In this study, patients had BP, ICP and bilateral MCA TCD velocity monitored before, during and after BP and CO2 challenges, applied in a random order, with measurements taken within 48 hours of injury. Four indices of reactivity were calculated: the PRx, the CORRx and the FVreact & ICPreact. At 48 hours post-injury inter-patient variation in cerebrovascular reactivity, as measured by these indices, is large and injury specific factors remain important determinants of the variance. Within patient analysis has identified instances where the combined monitoring of the PRx and the CORRx may provide information about the function of pressure autoregulation and further study of the combined use of these two indices of reactivity is warranted.
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Diez-Roux AV, Kiefe CI, Jacobs DR, Haan M, Jackson SA, Nieto FJ, Paton CC, Schulz R, Roux AV. Area characteristics and individual-level socioeconomic position indicators in three population-based epidemiologic studies. Ann Epidemiol 2001; 11:395-405. [PMID: 11454499 DOI: 10.1016/s1047-2797(01)00221-6] [Citation(s) in RCA: 284] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
PURPOSE There is growing interest in incorporating area indicators into epidemiologic analyses. Using data from the 1990 U.S. Census linked to individual-level data from three epidemiologic studies, we investigated how different area indicators are interrelated, how measures for different sized areas compare, and the relation between area and individual-level social position indicators. METHODS The interrelations between 13 area indicators of wealth/income, education, occupation, and other socioenvironmental characteristics were investigated using correlation coefficients and factor analyses. The extent to which block-group measures provide information distinct from census tract measures was investigated using intraclass correlation coefficients. Loglinear models were used to investigate associations between area and individual-level indicators. RESULTS Correlations between area measures were generally in the 0.5--0.8 range. In factor analyses, six indicators of income/wealth, education, and occupation loaded on one factor in most geographic sites. Correlations between block-group and census tract measures were high (correlation coefficients 0.85--0.96). Most of the variability in block-group indicators was between census tracts (intraclass correlation coefficients 0.72--0.92). Although individual-level and area indicators were associated, there was evidence of important heterogeneity in area of residence within individual-level income or education categories. The strength of the association between individual and area measures was similar in the three studies and in whites and blacks, but blacks were much more likely to live in more disadvantaged areas than whites. CONCLUSIONS Area measures of wealth/income, education, and occupation are moderately to highly correlated. Differences between using census tract or block-group measures in contextual investigations are likely to be relatively small. Area and individual-level indicators are far from perfectly correlated and provide complementary information on living circumstances. Differences in the residential environments of blacks and whites may need to be taken into account in interpreting race differences in epidemiologic studies.
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Lilly JW, Havey MJ, Jackson SA, Jiang J. Cytogenomic analyses reveal the structural plasticity of the chloroplast genome in higher plants. THE PLANT CELL 2001; 13:245-54. [PMID: 11226183 PMCID: PMC102240 DOI: 10.1105/tpc.13.2.245] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2000] [Accepted: 11/20/2000] [Indexed: 05/18/2023]
Abstract
A DNA fiber-based fluorescence in situ hybridization (fiber-FISH) technique was developed to analyze the structure and organization of a large number of intact chloroplast DNA (cpDNA) molecules from Arabidopsis, tobacco, and pea. Using this cytogenomic approach, we determined that 25 to 45% of the cpDNA within developing leaf tissue consists of circular molecules. Both linear and circular DNA fibers with one to four copies of the chloroplast genome were present, with monomers being the predominant structure. Arabidopsis and tobacco chloroplasts contained previously unidentified multimers (>900 kb) consisting of six to 10 genome equivalents. We further discovered rearranged cpDNA molecules of incomplete genome equivalents, confirmed by both differential hybridizations and size estimations. The unique cpDNA organization and novel structures revealed in this study demonstrate that higher plant cpDNA is more structurally plastic than previous sequence and electrophoretic analyses have suggested. Additionally, we demonstrate how the fiber-FISH-based cytogenomic approach allows for powerful analysis of very rare events that cannot be detected by traditional techniques such as DNA gel blot hybridization or polymerase chain reaction.
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MESH Headings
- Arabidopsis/genetics
- Chloroplasts/genetics
- Cytogenetics
- DNA, Chloroplast/chemistry
- DNA, Chloroplast/genetics
- DNA, Chloroplast/isolation & purification
- DNA, Circular/chemistry
- DNA, Circular/genetics
- DNA, Circular/isolation & purification
- Electrophoresis, Gel, Pulsed-Field
- Genome, Plant
- In Situ Hybridization, Fluorescence
- Nucleic Acid Conformation
- Pisum sativum/genetics
- Plants/genetics
- Species Specificity
- Nicotiana/genetics
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Adachi JD, Loannidis G, Berger C, Joseph L, Papaioannou A, Pickard L, Papadimitropoulos EA, Hopman W, Poliquin S, Prior JC, Hanley DA, Olszynski WP, Anastassiades T, Brown JP, Murray T, Jackson SA, Tenenhouse A. The influence of osteoporotic fractures on health-related quality of life in community-dwelling men and women across Canada. Osteoporos Int 2001; 12:903-8. [PMID: 11804016 DOI: 10.1007/s001980170017] [Citation(s) in RCA: 183] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Health-related quality of life (HRQL) was examined in relation to prevalent fractures in 4816 community-dwelling Canadian men and women 50 years and older participating in the Canadian Multicentre Osteoporosis Study (CaMos). Fractures were of three categories: clinically recognized main fractures, subclinical vertebral fractures and fractures at other sites. Main fractures were divided and analyzed at the hip, spine, wrist/forearm, pelvis and rib sites. Baseline assessments of anthropometric data, medical history, therapeutic drug use, spinal radiographs and prevalent fractures were obtained from all participants. The SF-36 instrument was used as a tool to measure HRQL. A total of 652 (13.5%) main fractures were reported. Results indicated that hip, spine, wrist/forearm, pelvis and rib fractures had occurred in 78 (1.6%), 40 (0.8%), 390 (8.1%), 19 (0.4%) and 125 (2.6%) individuals, respectively (subjects may have had more than one main fracture). Subjects who had experienced a main prevalent fracture had lower HRQL scores compared with non-fractured participants. The largest differences were observed in the physical functioning (-4.0; 95% confidence intervals (CI): -6.0, -2.0) and role-physical functioning domains (-5.8; 95% CI: -9.5, -2.2). In women, the physical functioning domain was most influenced by hip (-14.9%; 95% CI: -20.9, -9.0) and pelvis (-18.1; 95% CI: -27.6, -8.6) fractures. In men, the role-physical domain was most affected by hip fractures (-35.7; 95% CI: -60.4, -11.1). Subjects who experienced subclinical vertebral fractures had lower HRQL scores than those without prevalent fractures. In conclusion, HRQL was lower in the physical functioning domain in women and the role-physical domain in men who sustained main fractures at the hip. Subclinical vertebral fractures exerted a moderate effect on HRQL.
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Jackson SA, Cheng Z, Wang ML, Goodman HM, Jiang J. Comparative fluorescence in situ hybridization mapping of a 431-kb Arabidopsis thaliana bacterial artificial chromosome contig reveals the role of chromosomal duplications in the expansion of the Brassica rapa genome. Genetics 2000; 156:833-8. [PMID: 11014828 PMCID: PMC1461289 DOI: 10.1093/genetics/156.2.833] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Comparative genome studies are important contributors to our understanding of genome evolution. Most comparative genome studies in plants have been based on genetic mapping of homologous DNA loci in different genomes. Large-scale comparative physical mapping has been hindered by the lack of efficient and affordable techniques. We report here the adaptation of fluorescence in situ hybridization (FISH) techniques for comparative physical mapping between Arabidopsis thaliana and Brassica rapa. A set of six bacterial artificial chromosomes (BACs) representing a 431-kb contiguous region of chromosome 2 of A. thaliana was mapped on both chromosomes and DNA fibers of B. rapa. This DNA fragment has a single location in the A. thaliana genome, but hybridized to four to six B. rapa chromosomes, indicating multiple duplications in the B. rapa genome. The sizes of the fiber-FISH signals from the same BACs were not longer in B. rapa than those in A. thaliana, suggesting that this genomic region is duplicated but not expanded in the B. rapa genome. The comparative fiber-FISH mapping results support that chromosomal duplications, rather than regional expansion due to accumulation of repetitive sequences in the intergenic regions, played the major role in the evolution of the B. rapa genome.
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Clegg JS, Jackson SA, Sorgeloos P. Thermal resistance, developmental rate and heat shock proteins in Artemia franciscana, from San Francisco Bay and southern Vietnam. JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY 2000; 252:85-96. [PMID: 10962067 DOI: 10.1016/s0022-0981(00)00239-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Cysts (encysted gastrula embryos) of Artemia franciscana collected from salterns in San Francisco Bay, California, USA (SF) were inoculated into much warmer growth ponds in the Mekong Delta region of Vietnam (V) in 1996. V adults arising directly from these cysts during 17 April to 15 May produced their own cysts, which were collected, processed and stored until shipped to the USA for study. Adults grown in the laboratory from SF cysts (those used for the inoculation) were less resistant to high temperature than adults cultured from V cysts. V cysts produced heat-resistant adults, even though cultured under the same laboratory conditions as SF animals, at much lower temperatures than they ever experienced in Vietnam. Differences in thermal performance between SF and V adults were retained in the second generation, cultured from cysts produced in the laboratory by first generation adults, suggesting a genetic basis for the better heat resistance of V adults. We propose that the operation of natural selection in the Vietnam growth ponds produced adults with improved thermal tolerance, and that the basis for this tolerance was incorporated into the developmental program of their cysts. Surprisingly, differences in heat resistance of laboratory reared animals were not reflected in constitutive levels of the hsp70 family which were similar in first generation SF and V adults. A conditioning heat shock (HS, 37 degrees C, 30 min) led to the same level of induced thermotolerance in SF and V first generation adults when evaluated 24 h post-HS. Levels of hsp70 were also up-regulated at that time, but to about the same extent in SF and V adults. Developmental rates of SF cysts used for the inoculation were faster than those of cysts produced in Vietnam when both were incubated at 21+/-1 degrees C, suggesting that V cysts have become adapted to develop at higher temperatures.
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Clegg JS, Jackson SA, Popov VI. Long-term anoxia in encysted embryos of the crustacean, Artemia franciscana: viability, ultrastructure, and stress proteins. Cell Tissue Res 2000; 301:433-46. [PMID: 10994789 DOI: 10.1007/s004410000249] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Cells of encysted embryos of Artemia franciscana, the brine shrimp, are among the most resistant of all animal cells to extremes of environmental stress. We focus here on their ability to survive continuous anoxia for periods of years, during which their metabolic rate is undetectable. We asked whether their impressive tolerance was reflected in changes at the ultrastructural level. The ultrastructure of encysted embryos previously experiencing 38 days and 3.3 years of anoxia was compared with those not undergoing anoxia (controls). Rough endoplasmic reticulum was abundant in anoxic embryos, in spite of the absence of protein biosynthesis in their cells. Other cytoplasmic changes had occurred in the anoxic cells, but overall their structure was remarkably intact, in view of their 3 years of continuous anoxia. A major difference was the presence of abundant electron-dense granules in the nuclei of anoxic embryos; these were present but rare in nuclei of controls. Biochemical fractionation and Western immunoblotting confirmed previous observations that substantial amounts of the small heat shock/alpha-crystallin protein (p26) translocated into nuclei of anoxic embryos. We have no evidence that the dense granules contain this protein, but that remains a possibility. In contrast, and contrary to expectation, proteins of the hsp70 and 90 families did not undergo anoxia-induced nuclear translocation, an unusual result since such translocations have been widely observed in cells from a variety of organisms.
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Yunis C, Jackson SA, Carter L, Marcus C. Hypertension and associated risk factors in young African-American women attending a community health and wellness center. N C Med J 2000; 61:223-5. [PMID: 10917042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
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Jones DP, Robertson PA, Lunt B, Jackson SA. Radiation exposure during fluoroscopically assisted pedicle screw insertion in the lumbar spine. Spine (Phila Pa 1976) 2000; 25:1538-41. [PMID: 10851103 DOI: 10.1097/00007632-200006150-00013] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN An experimental model to assess radiation exposure during lumbar pedicle screw insertion. OBJECTIVES To measure skin (patient) and scatter (surgeon) doses of radiation during lumbar spine fluoroscopy to assess safety of the procedure for both the surgeon and patient and determine best practice. SUMMARY OF BACKGROUND DATA Fluoroscopy assists with accuracy of pedicle screw placement, yet the optimal technique of C-arm use and risk to both patient and operating room staff from radiation exposure are unknown. METHODS Entry- and scatter-dose recordings were made using a digital dosimeter while screening an anthropomorphic phantom prone on a radiolucent operating table. The source was positioned both superiorly and inferiorly with the height varied in the latter orientation to create a working space under the C-arm. The senior author's fluoroscopy records were reviewed in 140 consecutive cases. RESULTS In a series of 140 patients who underwent pedicle screw fixation, the fluoroscopy time was 1.4 minutes per case or 0.33 minutes per screw. In the source-superior position, the effective dose received by the patient was approximately 2.3 mSv per case. In the source-inferior position with a working space of 300 mm, the effective dose was 6.8 mSv. Scatter dose to the surgeon was higher in the source-superior position but was still less than 10% of recommended limits for the hand, thyroid, and eyes. CONCLUSIONS The source-superior position is the preferred position for pedicle screw screening if a working space is required. Patient exposure is minimized, and surgeon dose is well within current recommendations.
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Jackson SA, Burke GL. Heart disease prevention in US women. There is more work to be done. ARCHIVES OF FAMILY MEDICINE 2000; 9:516-7. [PMID: 10862213 DOI: 10.1001/archfami.9.6.516] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Jackson SA, Anderson RT, Johnson NJ, Sorlie PD. The relation of residential segregation to all-cause mortality: a study in black and white. Am J Public Health 2000; 90:615-7. [PMID: 10754978 PMCID: PMC1446199 DOI: 10.2105/ajph.90.4.615] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES This study investigated the influence of an aggregate measure of the social environment on racial differences in all-cause mortality. METHODS Data from the National Longitudinal Mortality Study were analyzed. RESULTS After adjustment for family income, age-adjusted mortality risk increased with increasing minority residential segregation among Blacks aged 25 to 44 years and non-Blacks aged 45 to 64 years. In most age/race/gender groups, the highest and lowest mortality risks occurred in the highest and lowest categories of residential segregation, respectively. CONCLUSIONS These results suggest that minority residential segregation may influence mortality risk and underscore the traditional emphasis on the social underpinnings of disease and death.
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Jackson SA, Tenenhouse A, Robertson L. Vertebral fracture definition from population-based data: preliminary results from the Canadian Multicenter Osteoporosis Study (CaMos). Osteoporos Int 2000; 11:680-7. [PMID: 11095171 DOI: 10.1007/s001980070066] [Citation(s) in RCA: 152] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The Canadian Multicenter Osteoporosis Study is a large population-based prospective study of osteoporosis in the Canadian population. The study involves 9424 subjects, both male and female, from nine centers and seven regions of Canada. Each subject completed an extensive interview to obtain medical, demographic and lifestyle information, and was examined by dual-energy X-ray absorptiometry of the spine and hip, ultrasound of the heel and, for subjects over 50 years of age, lateral spine radiographs. Spinal morphometry of the initial radiographs was performed to determine the prevalence of vertebral deformity. A method is utilized to extract reference norms for vertebral shape from a subset of the population data, which is then used to categorize any deformity within the whole data set. Using 3 standard deviations (SD) as a limit of normality', the male prevalence of 21.5% was similar to the female prevalence of 23.5%. Using 4 SD this reduced to 7.3% and 9.3% respectively. The younger men (50-59 years) showed a higher prevalence of deformity than the women and a lower increase of prevalence with age. In the older age group (over 80 years) the female prevalence of 45% compared with 36% for the men using 3 SD (grade 1) to define the limit of normality. The female group presented with more severe deformities on average than the male group. This continuing study will provide longitudinal information regarding the development of osteoporosis and associated risk factors which will eventually be of use to develop public health policies.
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Tenenbaum G, Fogarty GJ, Jackson SA. The flow experience: a Rasch analysis of Jackson's Flow State Scale. JOURNAL OF OUTCOME MEASUREMENT 1999; 3:278-94. [PMID: 10431494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
Jackson and Marsh (1996) reported the development of a Flow State Scale (FSS) for use in sport and physical activity. The FSS contains 36 items measuring the nine dimensions of flow described by Csikszentmihalyi (1990, 1993). Jackson and Marsh reported high internal consistency estimates for the subscales and evidence for nine first-order factors and one second-order factor when confirmatory factor analytic techniques were used. The present study extended this validation work by subjecting the data from the original sample (N = 394) of elite younger athletes and a subsequent sample (N = 398) of older athletes to Rasch analysis. These Rasch analyses showed quite clearly that the flow dimensions may be conceptualised as a continuum with "autotelic experience" being experienced more readily than dimensions such as "transformation of time", a state that may only be encountered at the height of a deep flow experience. The Rasch analyses provide useful additional information about the areas of the flow continuum tapped by the items and scales of the FSS and, in so doing, help to confirm the construct validity and generalisability of the scale itself.
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Jackson SA, Dong F, Jiang J. Digital mapping of bacterial artificial chromosomes by fluorescence in situ hybridization. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 1999; 17:581-7. [PMID: 10205912 DOI: 10.1046/j.1365-313x.1999.00398.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The bacterial artificial chromosome (BAC) has become the most popular tool for cloning large DNA fragments. The inserts of most BAC clones average 100-200 kilobases (kb) and molecular characterization of such large DNA fragments is a major challenge. Here we report a simple and expedient technique for physical mapping of BAC inserts. Individual BAC molecules were immobilized on glass slides coated with Poly-L-lysine. The intact circular BAC molecules were visualized by fluorescence in situ hybridization using BAC DNA as a probe. The 7.4 kb BAC vector was extended to approximately 2.44 kb per micrometer. Digitally measured linear distances can be transformed into kilobases of DNA using the extension of BAC vector as a standard calibration. We mapped DNA fragments as small as 2 kb directly on circular BAC molecules. A rice BAC clone containing both tandem and dispersed repeats was analyzed using this technique. The distribution and organization of the different repeats within the BAC insert were efficiently determined. The results showed that this technique will be especially valuable for characterizing BAC clones that contain complex repetitive DNA sequences.
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Miller JT, Dong F, Jackson SA, Song J, Jiang J. Retrotransposon-related DNA sequences in the centromeres of grass chromosomes. Genetics 1998; 150:1615-23. [PMID: 9832537 PMCID: PMC1460426 DOI: 10.1093/genetics/150.4.1615] [Citation(s) in RCA: 132] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Several distinct DNA fragments were subcloned from a sorghum (Sorghum bicolor) bacterial artificial chromosome clone 13I16 that was derived from a centromere. Three fragments showed significant sequence identity to either Ty3/gypsy- or Ty1/copia-like retrotransposons. Fluorescence in situ hybridization (FISH) analysis revealed that the Ty1/copia-related DNA sequences are not specific to the centromeric regions. However, the Ty3/gypsy-related sequences were present exclusively in the centromeres of all sorghum chromosomes. FISH and gel-blot hybridization showed that these sequences are also conserved in the centromeric regions of all species within Gramineae. Thus, we report a new retrotransposon that is conserved in specific chromosomal regions of distantly related eukaryotic species. We propose that the Ty3/gypsy-like retrotransposons in the grass centromeres may be ancient insertions and are likely to have been amplified during centromere evolution. The possible role of centromeric retrotransposons in plant centromere function is discussed.
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Alexander JS, Jackson SA, Chaney E, Kevil CG, Haselton FR. The role of cadherin endocytosis in endothelial barrier regulation: involvement of protein kinase C and actin-cadherin interactions. Inflammation 1998; 22:419-33. [PMID: 9675612 DOI: 10.1023/a:1022325017013] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
We have previously reported that exposure of endothelial monolayers to low (0.12 mM) extracellular calcium significantly decreased the endothelial solute barrier, and that this effect was reversed by restoring 'normal' (1.2 mM) calcium (1). This effect was shown to be dependent on cadherins, however the molecular mechanisms through which barrier was altered by low calcium were not characterized. Here we investigated the mechanism of increased endothelial permeability produced by low calcium exposure. Endothelial permeability was significantly increased by exposure to low (0.12 mM) calcium; this effect was attenuated by pre-treatment with the protein kinase C (PKC) inhibitor, staurosporine (2 x 10(-7) M) for 30 min. Cell border retraction and gap formation produced by low calcium was also prevented by staurosporine. Treatment of monolayers with 0.12 mM calcium also stimulated the endocytosis of endothelial cadherins. This low calcium mediated cadherin endocytosis was also prevented by pretreatment with staurosporine. Low calcium mediated endocytosis was also prevented by the actin filament toxin, cytochalasin D (1 ug/ml, 30 min). We conclude that the mechanism of low calcium mediated loss of endothelial barrier function is mediated in part by a PKC dependent endocytosis of endothelial cadherins, which may involve interactions with the actin cytoskeleton. Physiological regulation of the in vivo endothelial barrier may also involve PKC dependent-actin mediated endocytosis of cadherin junctional elements.
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Jackson SA, Wang ML, Goodman HM, Jiang J. Application of fiber-FISH in physical mapping of Arabidopsis thaliana. Genome 1998; 41:566-72. [PMID: 9796106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Arabidopsis thaliana has become a model plant species for genetic studies because of its small genome and short juvenility period. However, the small chromosomes of this species are not suitable for classical cytogenetic studies. Here we demonstrate that the fluorescence in situ hybridization (FISH) technique using extended DNA fibers can be a powerful tool in the physical mapping of the A. thaliana genome. Using a refined fiber-FISH technique we were able to measure DNA clusters as long as 1.71 Mb, more than 1% of the A. thaliana genome. Several small DNA loci, including the telomeres and a dispersed repetititve DNA sequence, mi167, were also analyzed with this technique. The results show that without known adjacent DNA markers such small DNA loci cannot be mapped precisely using fiber-FISH. One of the most difficult obstacles in physical mapping by contig assembly is closing the gaps that are present between adjacent contigs. Currently available molecular techniques are not sufficient to accurately estimate the physical sizes of these gaps. We isolated bacterial artificial chromosome (BAC) clones bordering gaps 2 and 3 on the physical contig map of A. thaliana chromosome II. The BAC clones were used in fiber-FISH analysis and the physical sizes of the two gaps were estimated as 31 kb and more than 500 kb, respectively. Thus, we have demonstrated that fiber-FISH is an efficient technique for determining the physical size of gaps on molecular contig maps.
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Dong F, Miller JT, Jackson SA, Wang GL, Ronald PC, Jiang J. Rice (Oryza sativa) centromeric regions consist of complex DNA. Proc Natl Acad Sci U S A 1998; 95:8135-40. [PMID: 9653153 PMCID: PMC20942 DOI: 10.1073/pnas.95.14.8135] [Citation(s) in RCA: 145] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Rice bacterial artificial chromosome clones containing centromeric DNA were isolated by using a DNA sequence (pSau3A9) that is present in the centromeres of Gramineae species. Seven distinct repetitive DNA elements were isolated from a 75-kilobase rice bacterial artificial chromosome clone. All seven DNA elements are present in every rice centromere as demonstrated by fluorescence in situ hybridization. Six of the elements are middle repetitive, and their copy numbers range from approximately 50 to approximately 300 in the rice genome. Five of these six middle repetitive DNA elements are present in all of the Gramineae species, and the other element is detected only in species within the Bambusoideae subfamily of Gramineae. All six middle repetitive DNA elements are dispersed in the centromeric regions. The seventh element, the RCS2 family, is a tandem repeat of a 168-bp sequence that is represented approximately 6,000 times in the rice genome and is detected only in Oryza species. Fiber-fluorescence in situ hybridization analysis revealed that the RCS2 family is organized into long uninterrupted arrays and resembles previously reported tandem repeats located in the centromeres of human and Arabidopsis thaliana chromosomes. We characterized a large DNA fragment derived from a plant centromere and demonstrated that rice centromeres consist of complex DNA, including both highly and middle repetitive DNA sequences.
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O'Donnell PG, Jackson SA, Tung KT, Hassan B, Wilkins B, Mead GM. Radiological appearances of lymphomas arising from mucosa-associated lymphoid tissue (MALT) in the lung. Clin Radiol 1998; 53:258-63. [PMID: 9585040 DOI: 10.1016/s0009-9260(98)80123-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We review the radiological findings in 13 patients with histologically proven (n = 10) or clinically diagnosed (n = 3) lymphomas arising in mucosa-associated lymphoid tissue (MALT) of the lung. These rare B-cell lymphomas typically follow an indolent course, and many cases are still being incorrectly described in current radiological literature under the term pseudolymphoma. The patients frequently give a history of autoimmune disease involving the affected organ, and involvement of another mucosal site as part of a disseminated MALT lymphoma, is common. The radiographic patterns of pulmonary parenchymal involvement in lung MALT lymphomas have been reviewed, and correlation made with their clinical behaviour.
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Hovenga S, Tulleken JE, Möller LV, Jackson SA, vd Werf TS, Zijlstra JG. Dog-bite induced sepsis: a report of four cases. Intensive Care Med 1997; 23:1179-80. [PMID: 9434927 DOI: 10.1007/s001340050478] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Occasionally, a dog-bite is complicated by a systemic overwhelming infection. We report four consecutive patients who were admitted to our intensive care unit because of sepsis syndrome following dog-bites. The history of these patients did not reveal any immunocompromising conditions. Capnocytophaga canimorsus (C. canimorsus) was cultured from the blood culture of 2 patients. Our data illustrate that in patients with lack of immune-deficiency severe sepsis may develop.
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Jackson SA, Clinton CW. Postoperative management of hypothermia of intra-operative origin--experience with a forced-air convective warming device. S AFR J SURG 1997; 35:134-8. [PMID: 9429331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Hypothermia develops during the intra-operative period partly as a result of disordered thermoregulation induced by anaesthesia, and partly because of the nature of the operation or injury and the surgical environment. Both the hypothermic state and the consequences of physiological attempts to return the core temperature to normal, which take place during the postoperative period, are associated with non-beneficial effects. Attempts to prevent an intra-operative decline in core temperature are a part of anaesthesia management. However, most of the traditional options available are inefficient or ineffective, especially if used as a single intervention and particularly in adults. This study evaluates the performance of a new device, the forced-air convective warmer, in the management of the postoperative hypothermic state. Results show that the device made a significant difference to the thermal state of a group of hypothermic postoperative patients when compared with a hypothermic control group, but only if used for at least 2 hours after the operation.
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Jackson SA, Treharne DA, Boucher J. Rhythm and language in children with moderate learning difficulties. EUROPEAN JOURNAL OF DISORDERS OF COMMUNICATION : THE JOURNAL OF THE COLLEGE OF SPEECH AND LANGUAGE THERAPISTS, LONDON 1997; 32:99-108. [PMID: 9135715 DOI: 10.3109/13682829709021463] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The relationship between rhythmic ability, syllabic structure in the production of single words and two-word phrases, and overall language ability was assessed in a group of 22 children, aged between 4;0-8;0, with moderate learning difficulties in the absence of gross sensory, motor or behavioural difficulties. It was predicted that rhythmic ability would correlate significantly both with syllable production and with overall language attainment. We further predicted that clapping to highlight syllable number and rhythm would significantly improve syllable production. The first hypothesis was supported in so far as rhythmic ability correlated significantly with syllable production. However, rhythmic ability did not correlate significantly with overall language attainment. The second hypothesis was supported. The results are discussed in terms of their theoretical implications for our understanding of language development in children with moderate learning difficulties and in terms of their practical implications for therapy.
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