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Beverley CS, Probst J, Williams EM, Rivers P, Glover SH. Differences in Electronic Medical Record Implementation and Use According to Geographical Location and Organizational Characteristics of US Federally Qualified Health Centers. INTERNATIONAL JOURNAL OF HEALTHCARE INFORMATION SYSTEMS AND INFORMATICS 2012. [DOI: 10.4018/jhisi.2012070101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Electronic medical records (EMRs) are at the forefront of the national healthcare agenda and this paper examines EMR implementation and usage based on data from the 2009 Commonwealth Fund National Survey of Federally Qualified Health Centers (FQHC). Chi-square analysis was used to examine differences in EMR implementation and usage. Logistic regression analysis was used to understand the adjusted associations between EMR implementation and usage. A significant finding of this study was that simple EMRs were implemented in more than half of FQHCs in the Northeast, Southern, and Western regions of the United States and EMRs in more than half of the FQHCs in the Southern and Western regions are not even utilized. These findings indicate simple EMR usage and full EMR implementation need improvement to meet the requirements of the American Recovery and Reinvestment Act by 2014, or face reduction in Medicare and Medicaid reimbursements.
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Adams SA, Butler WM, Fulton J, Heiney SP, Williams EM, Delage AF, Khang L, Hebert JR. Racial disparities in breast cancer mortality in a multiethnic cohort in the Southeast. Cancer 2012; 118:2693-9. [PMID: 21953316 PMCID: PMC3269560 DOI: 10.1002/cncr.26570] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Revised: 07/28/2011] [Accepted: 08/24/2011] [Indexed: 11/12/2022]
Abstract
BACKGROUND Although much has been done to examine those factors associated with higher mortality among African American women, there is a paucity of literature that examines disparities among rural African Americans in South Carolina. The purpose of this investigation was to examine the association of race and mortality among breast cancer patients in a large cohort residing in South Carolina for which treatment regimens are standardized for all patients. METHODS Subjects included 1209 women diagnosed with breast cancer between 2000 and 2002 at a large, local hospital containing a comprehensive breast center. Kaplan-Meier survival curves were calculated to determine survival rates among African American and European American women, stratified by disease stage or other prognostic characteristics. Adjusting for various characteristics, Cox multivariate survival models were used to estimate the hazard ratio (HR). RESULTS The 5-year overall all-cause mortality survival proportion was ∼78% for African American women and ∼89% for European American women, P < 0.01. In analyses of subpopulations of women with identical disease characteristics, African American women had significantly higher mortality than European American women for the same type of breast cancer disease. In multivariate models, African American women had significantly higher mortality than European American women for both breast cancer-specific death (HR, 2.41; 95% confidence interval [CI], 1.21-4.79) and all-cause mortality (HR, 1.42; 95% CI, 1.06-1.89). CONCLUSIONS African American women residing in rural South Carolina had lower survival for breast cancer even after adjustment for disease-related prognostic characteristics. These findings support health interventions among African American breast cancer patients aimed at tertiary prevention strategies or further down-staging of disease at diagnosis.
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Williams EM, Pickerd N, Eriksen M, Øygarden K, Kotecha S. Estimation of tidal ventilation in preterm and term newborn infants using electromagnetic inductance plethysmography. Physiol Meas 2012; 32:1833-45. [PMID: 22027661 DOI: 10.1088/0967-3334/32/11/001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Tidal volume (VT) measurements in newborn infants remain largely a research tool. Tidal ventilation and breathing pattern were measured using a new device, FloRight, which uses electromagnetic inductive plethysmography,and compared simultaneously with pneumotachography in 43 infants either receiving no respiratory support or continuous positive airway pressure (CPAP).Twenty-three infants were receiving CPAP (gestational age 28 ± 2 weeks, mean ± SD) and 20 were breathing spontaneously (gestational age 34 ± 4 weeks). The two methods were in reasonable agreement, with VT (r2 = 0.69) ranging from 5 to 23 ml (4–11 ml kg−1) with a mean difference of 0.4 ml and limit of agreement of −4.7 to + 5.5 ml. For respiratory rate, minute ventilation,peak flow and breathing pattern indices, the mean difference between the two methods ranged between 0.7% and 5.8%. The facemask increased the respiratory rate (P < 0.001) in both groups with the change in VT being more pronounced in the infants receiving no respiratory support. Thus, FloRight provides an easy to use technique to measure term and preterm infants in the clinical environment without altering the infant's breathing pattern.
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Williams EM, Lee MD, Preston G, Williams A, Wigfall LT, Wilkinson L, Hatala J, Hassan R, Glover SH. Development of the Soldier Health Promotion to Examine and Reduce Health Disparities (SHPERHD) Project Coordinating Center: challenges and opportunities within a university/community partnership. Mil Med 2012; 176:757-62. [PMID: 22128716 DOI: 10.7205/milmed-d-10-00465] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The Soldier Health Promotion to Examine and Reduce Health Disparities (SHPERHD) Project was designed to be a partnership between the Institute for Partnerships to Eliminate Health Disparities at the University of South Carolina and the Fort Jackson United States Army Base located in Columbia, South Carolina. SHPERHD Project researchers are studying problems related to obesity and weight management, musculoskeletal injuries and infection, and mental health issues during recruitment, basic training, and post-deployment. In order to successfully develop targeted interventions to prevent and lower the incidence of injury, promote healthy nutrition, and decrease mental health issues, at the same time also reducing disparity gaps, the SHPERHD Project comprises a professional, technical, and administrative staff with specific competence in the operation of a Coordinating Center to handle the wide variety of areas related to military studies. This article discusses the procedures and processes that were implemented in the development of the SHPERHD Project Coordinating Center.
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Cummins SL, Williams EM. CUTANEOUS SENSITIVITY TO ACID-FAST BACILLI IN SUSPENSION. BRITISH MEDICAL JOURNAL 2011; 1:702-3. [PMID: 20778210 DOI: 10.1136/bmj.1.3824.702] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Wigfall LT, Williams EM, Sebastian N, Glover SH. HIV testing among Deep South residents 50 to 64 years old with cardiovascular disease and/or diabetes. J Natl Med Assoc 2011; 102:1150-7. [PMID: 21287895 DOI: 10.1016/s0027-9684(15)30769-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
PURPOSE To describe HIV testing among Deep South residents aged 50 to 64 years old with cardiovascular disease (CVD) and/or diabetes. METHODS Deep South residents from Alabama, Georgia, Louisiana, Mississippi, North Carolina, and South Carolina who completed the 2008 Behavioral Risk Factor Surveillance System (BRFSS) survey were sampled. Associations between chronic health conditions (CVD, diabetes) and human immunodeficiency virus (HIV) testing were examined. RESULTS Fewer than one-third (30.8%) of the sample (n = 1017) reported that they had been tested for HIV. Of the weighted sample of adults tested for HIV, the mean age--56.63 +/- 0.20 SE (95% confidence interval [CI], 56.24-57.03)--was significantly lower than that of those who had never been tested for HIV--57.60 +/- 0.12 SE (95% CI, 57.37-57.84; p < .0001). Although not statistically significant, HIV testing was slightly higher among men (53.3%) (p = .9432). Persons with CVD or diabetes were 22% less likely to report that they had been tested for HIV, compared to those with both CVD and diabetes (adjusted odds ratio [AOR], 0.776; 95% CI, 0.611-0.985). CONCLUSIONS Chronic conditions (CVD, diabetes) among HIV-infected persons can be adversely affected by antiretroviral regimens. All adults 50 to 64 years old should be routinely offered an HIV test if their HIV serostatus is unknown, regardless of perceived risk for HIV/AIDS. Our findings suggest that linking HIV testing with routine checkups for persons with CVD and/or diabetes is a potentially missed opportunity for earlier diagnosis of HIV infection, especially among older adults who are at a greater risk of being diagnosed with AIDS within 1 year of an initial HIV-positive diagnosis.
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Abstract
1. Measurements of contractions, conduction velocity and intracellular potential were made on isolated rabbit atria under four sets of conditions: high bicarbonate/high CO(2) (HH), low bicarbonate/low CO(2) (LL), high bicarbonate/low CO(2) (HL) and low bicarbonate/high CO(2) (LH). The ratio high/low was the same for the bicarbonate and CO(2) concentrations, so that HH had the same pH as LL.2. Acid solutions caused a fall of a few mV in the resting potential, but not in the overshoot. They reduced conduction velocity and rate of rise of the action potential. They depressed contractions, but prolonged the tail of the action potential.3. Alkaline solutions caused the converse changes, but, with the exception of the effect on the duration of the action potential, the relation with pH was markedly alinear, in that a rise in pH had much less effect than an equivalent fall.4. Statistical tests were devised to decide whether the observed changes were associated primarily with pH, P(CO(2) ) or bicarbonate. By far the strongest association was with external pH. Changes in P(CO(2) ), per se, had no significant effect.
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Wigfall L, Duffus WA, Annang L, Richter DL, Torres ME, Williams EM, Glover SH. Pap test and HIV testing behaviors of South Carolina women 18-64 years old. JOURNAL OF THE SOUTH CAROLINA MEDICAL ASSOCIATION (1975) 2009; 105:274-280. [PMID: 20108718 PMCID: PMC2874936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
BACKGROUND Pap tests are used to detect abnormal cell growth in the cervix. Early detection of precancerous cells increases the likelihood of treatment success. In fact, the Pap test is one of only a few cancer screening procedures that can prevent cancer by virtue of identifying and intervening upon abnormal precancerous cells in the early stages. There has been a growing prevalence of cervical cancer among HIV-positive women. Early diagnosis is essential to improving survival outcomes of women living with HIV/AIDS. The purpose of this study was to describe Pap test behaviors among women in South Carolina and examine its relationship with HIV testing. METHODS Behavioral Risk Factor Surveillance System (BRFSS) data from 2008 were analyzed. Chi-square tests and logistic regression analyses were performed to describe Pap test behaviors among our sample (n=3,404) of non-Hispanic White and non-Hispanic Black women (18–64 years old). RESULTS The majority of participants (97%) reported ever having a Pap test. Participants who reported never having a Pap test were 50% less likely to have ever been tested for HIV. CONCLUSIONS The participants in our study met the Healthy People 2010 target of ever having a Pap test. However, less than half of participants (42%) had ever been tested for HIV. A larger proportion of women who have had a Pap test had also been tested for HIV. PRACTICE IMPLICATIONS Our findings suggest that offering women an HIV test during routine Pap tests may present an opportunity to increase the number of women in South Carolina who know their HIV serostatus.
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Prosser GA, Copp JN, Syddall SP, Williams EM, Smaill JB, Wilson WR, Patterson AV, Ackerley DF. Discovery and evaluation of Escherichia coli nitroreductases that activate the anti-cancer prodrug CB1954. Biochem Pharmacol 2009; 79:678-87. [PMID: 19852945 DOI: 10.1016/j.bcp.2009.10.008] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Revised: 10/07/2009] [Accepted: 10/09/2009] [Indexed: 10/20/2022]
Abstract
Gene-directed enzyme prodrug therapy (GDEPT) aims to achieve highly selective tumor-cell killing through the use of tumor-tropic gene delivery vectors coupled with systemic administration of otherwise inert prodrugs. Nitroaromatic prodrugs such as CB1954 hold promise for GDEPT as they are readily reduced to potent DNA alkylating agents by bacterial nitroreductase enzymes (NTRs). Transfection with the nfsB gene from Escherichia coli can increase the sensitivity of tumor cells to CB1954 by greater than 1000-fold. However, poor catalytic efficiency limits the activation of CB1954 by NfsB at clinically relevant doses. A lack of flexible, high-throughput screening technology has hindered efforts to discover superior NTR candidates. Here we demonstrate how the SOS chromotest and complementary screening technologies can be used to evaluate novel enzymes that activate CB1954 and other bioreductive and/or genotoxic prodrugs. We identify the major E. coli NTR, NfsA, as 10-fold more efficient than NfsB in activating CB1954 as purified protein (k(cat)/K(m)) and when over-expressed in an E. coli nfsA(-)/nfsB(-) gene deleted strain. NfsA also confers sensitivity to CB1954 when expressed in HCT-116 human colon carcinoma cells, with similar efficiency to NfsB. In addition, we identify two novel E. coli NTRs, AzoR and NemA, that have not previously been characterized in the context of nitroaromatic prodrug activation.
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Williams EM, Heusch AI, McCarthy PW. Thermal screening of facial skin arterial hot spots using non-contact infrared radiometry. Physiol Meas 2008; 29:341-8. [PMID: 18367809 DOI: 10.1088/0967-3334/29/3/005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Non-contact infrared thermometry of facial skin offers advantages over less accessible internal body sites, especially when considering mass screening for febrile infectious disease. The forehead offers an obvious site, but does not present an isothermic surface, as various small arteries passing close to the surface create 'hot-spots'. The aim of this study is to use non-contact infrared (IR) thermometry to determine the link between the temperature at specific facial skin sites and clinical body temperature. A sample of 169 asymptomatic adults (age range 18-54 years) was screened with IR thermometers (Braun Thermoscan proLT for auditory meatus (AM) temperature representing clinical body temperature, and a Raytek, Raynger MX for skin surface temperature). Peak IR skin temperature was measured over the course of each posterior auricular artery (PAA) and each superficial temporal artery (STA). In a sub-group (n = 54) the peak skin temperature of the forehead's metopic region (MR) was also recorded. There were no differences (P > 0.05) between the PAA and STA at 34.2 +/- 0.9 degrees C and 34.2 +/- 0.7 degrees C, respectively, which were 2.5 degrees C cooler than the AM temperature (36.7 +/- 0.5 degrees C, p < 0.001). Although there was no correlation between AM and PAA or STA there was a correlation (r2 = 0.63, p < 0.001) between PAA and STA. There were no asymmetric temperature differences between the left and right sides and males had warmer skin over the MR (F, 33.6 +/- 0.7 degrees C versus M, 34.4 +/- 0.6 degrees C, p < 0.001). Although a lack of correlation between either PAA or STA and AM was apparent in asymptomatics, further research in symptomatics is required to determine the usefulness of these measurements in mass screening of conditions such as fever.
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Dowe G, Smilkle MF, Thesiger C, Williams EM. Bloodborne sexually transmitted infections in patients presenting for substance abuse treatment in Jamaica. Sex Transm Dis 2002; 28:266-9. [PMID: 11354264 DOI: 10.1097/00007435-200105000-00004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Substance use, including alcohol and illicit drugs, increases the risk for the acquisition and transmission of sexually transmitted infection (STI). GOAL To determine the prevalence of bloodborne STI including HIV, human T-cell lymphotrophic virus type 1, hepatitis B virus, and syphilis in residents of a detoxification and rehabilitation unit in Jamaica. STUDY DESIGN The demographic characteristics and the results of laboratory investigations for STI in 301 substance abusers presenting during a 5-year period were reviewed. The laboratory results were compared with those of 131 blood donors. RESULTS The substances used by participants were alcohol, cannabis, and cocaine. None of the clients was an IV drug user. Female substance abusers were at higher risk for STI. The prevalence of STI in substance abusers did not differ significantly from that in blood donors (12% versus 10%); however, the prevalence of syphilis in substance abusers was significantly higher than that in blood donors (6% versus 3%, P < 0.05). The prevalence of syphilis was dramatically increased in female substance abusers and female blood donors (30%, P < 0.001 and 13%, P < 0.05, respectively). An excess of human T-cell lymphotrophic virus type 1 was also observed in female compared with male substance abusers. Unemployment was identified also as a risk factor for sexually transmitted disease in substance abusers. CONCLUSION The results endorsed the policy of screening detoxification clients for STI and indicate a need for gender-specific approaches to the control of substance abuse and STI in Jamaica.
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Thewissen JG, Williams EM, Roe LJ, Hussain ST. Skeletons of terrestrial cetaceans and the relationship of whales to artiodactyls. Nature 2001; 413:277-81. [PMID: 11565023 DOI: 10.1038/35095005] [Citation(s) in RCA: 140] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Modern members of the mammalian order Cetacea (whales, dolphins and porpoises) are obligate aquatic swimmers that are highly distinctive in morphology, lacking hair and hind limbs, and having flippers, flukes, and a streamlined body. Eocene fossils document much of cetaceans' land-to-water transition, but, until now, the most primitive representative for which a skeleton was known was clearly amphibious and lived in coastal environments. Here we report on the skeletons of two early Eocene pakicetid cetaceans, the fox-sized Ichthyolestes pinfoldi, and the wolf-sized Pakicetus attocki. Their skeletons also elucidate the relationships of cetaceans to other mammals. Morphological cladistic analyses have shown cetaceans to be most closely related to one or more mesonychians, a group of extinct, archaic ungulates, but molecular analyses have indicated that they are the sister group to hippopotamids. Our cladistic analysis indicates that cetaceans are more closely related to artiodactyls than to any mesonychian. Cetaceans are not the sister group to (any) mesonychians, nor to hippopotamids. Our analysis stops short of identifying any particular artiodactyl family as the cetacean sister group and supports monophyly of artiodactyls.
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Smikle MF, Dowe G, Williams EM, Thesiger C. Antibodies to hepatitis B virus and hepatitis C virus in residential detoxification clients in Jamaica. Hum Antibodies 2001; 9:231-3. [PMID: 11341177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
The role of non-injecting drug abuse in viral hepatitis has not been studied widely and is not well understood. A total of 301 substance abusers, residents of a detoxification/rehabilitation unit, were investigated for exposure to hepatitis B virus (HBV) and hepatitis C virus (HCV). Samples of serum were tested for anti-HCV and anti-HBc antibodies and HBsAg. All of the patients were non-injecting drug users (non-IDUs). The prevalence of anti-HCV was 1.7%; anti-HBc was found in 28.7% and HbsAg in 0.6% of patients. Anti-HCV positivity correlated with the presence of elevated aminotransferases (80%). Exposure to HBV correlated significantly with gender (p < 0.05); age (p < 0.05); and duration of substance abuse (p < 0.05). No significant correlations were found between HCV and/or HBV infection, the drug of abuse, HIV, HTLV-1 or syphilitic infection. Residential detoxification/rehabilitation provides an opportune moment to identify and treat HCV positive substance abusers in the attempt to avert the severe hepatic sequelae. Measures which exclude substance abusers from volunteer blood donation should be considered.
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Ashcroft KW, Leck JH, Sandstrom DR, Stimpson BP, Williams EM. Apparatus for the study of electron stimulated desorption of ions from surfaces. ACTA ACUST UNITED AC 2001. [DOI: 10.1088/0022-3735/5/11/023] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Gatta G, Capocaccia R, Sant M, Bell CM, Coebergh JW, Damhuis RA, Faivre J, Martinez-Garcia C, Pawlega J, Ponz de Leon M, Pottier D, Raverdy N, Williams EM, Berrino F. Understanding variations in survival for colorectal cancer in Europe: a EUROCARE high resolution study. Gut 2000; 47:533-8. [PMID: 10986214 PMCID: PMC1728079 DOI: 10.1136/gut.47.4.533] [Citation(s) in RCA: 210] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
BACKGROUND Marked differences in population based survival across Europe were found for colorectal cancers diagnosed in 1985-1989. AIMS To understand the reasons for these differences in survival in a new analysis of colorectal cancers diagnosed between 1988 and 1991. SUBJECTS A total of 2720 patients with adenocarcinoma of the large bowel from 11 European cancer registries (CRs). METHODS We obtained information on stage at diagnosis, diagnostic determinants, and surgical treatment (not routinely collected by CRs) and analysed the data in relation to three year observed survival, calculating relative risks (RRs) of death and adjusting for age, sex, site, stage, and determinants of stage. RESULTS Three year observed survival rates ranged from 25% (Cracow) to 59% (Modena), and were low in the Thames area (UK) (38%). Survival rates between registries for "resected" patients varied less than those for all patients. When age, sex, and site were considered, RRs ranged from 0.7 (95% confidence intervals (CI) 0.6-0.9) (Modena) to 2.3 (95% CI 1.9-2.9) (Cracow). After further adjustment by stage, between registry RR variation was between 0.8 (95% CI 0.6-0.9) and 1.8 (95% CI 1.5-2.2). Inter-registry RR differences were slightly reduced when the determinants of stage (number of nodes examined and liver imaging) were included in the model. The reduction was marked for the UK registries. CONCLUSIONS The wide differences across Europe in colorectal cancer survival depend to a large extent on differences in stage at diagnosis. There are wide variations in diagnostic and surgical practices. There was a twofold range in the risk of death from colorectal cancer even after adjustment for surgery and disease stage.
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Williams EM, Viale JP, Hamilton RM, McPeak H, Sutton L, Hahn CE. Within-breath arterial PO2 oscillations in an experimental model of acute respiratory distress syndrome. Br J Anaesth 2000; 85:456-9. [PMID: 11103189 DOI: 10.1093/bja/85.3.456] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Tidal ventilation causes within-breath oscillations in alveolar oxygen concentration, with an amplitude which depends on the prevailing ventilator settings. These alveolar oxygen oscillations are transmitted to arterial oxygen tension, PaO2, but with an amplitude which now depends upon the magnitude of venous admixture or true shunt, QS/QT. We investigated the effect of positive end-expiratory pressure (PEEP) on the amplitude of the PaO2 oscillations, using an atelectasis model of shunt. Blood PaO2 was measured on-line with an intravascular PaO2 sensor, which had a 2-4 s response time (10-90%). The magnitude of the time-varying PaO2 oscillation was titrated against applied PEEP while tidal volume, respiratory rate and inspired oxygen concentration were kept constant. The amplitude of the PaO2 oscillation, delta PaO2, and the mean PaO2 value varied with the level of PEEP applied. At zero PEEP, both the amplitude and the mean were at their lowest values. As PEEP was increased to 1.5 kPa, both delta PaO2 and the mean PaO2 increased to a maximum. Thereafter, the mean PaO2 increased but delta PaO2 decreased. Clear oscillations of PaO2 were seen even at the lowest mean PaO2, 9.5 kPa. Conventional respiratory models of venous admixture predict that these PaO2 oscillations will be reduced by the steep part of the oxyhaemoglobin dissociation curve if a constant pulmonary shunt exists throughout the whole respiratory cycle. The facts that the PaO2 oscillations occurred at all mean PaO2 values and that their amplitude increased with increasing PEEP suggest that QS/QT, in the atelectasis model, varies between end-expiration and end-inspiration, having a much lower value during inspiration than during expiration.
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Williams EM, Madgwick RG, Thomson AH, Morris MJ. Expiratory airflow patterns in children and adults with cystic fibrosis. Chest 2000; 117:1078-84. [PMID: 10767243 DOI: 10.1378/chest.117.4.1078] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
STUDY OBJECTIVE To determine whether tidal expiratory airflow patterns change with increasing airways obstruction in patients with cystic fibrosis. DESIGN An observational study. SETTING Lung function laboratory. PATIENTS Sixty-four children and young adults with cystic fibrosis. MEASUREMENTS After measuring FEV(1) and airways resistance using body plethysmography, each subject was seated and asked to mouth breathe through a pneumotachograph for 2 min. The collected data were analyzed, and three expiratory airflow pattern-sensitive indexes were computed. The first index was derived from the ratio of the time to reach peak expiratory flow to the total expiratory time (tPTEF/tE). The second index, Trs, was an estimate of the time constant of the passive portion of expiration. The third index, f1.gif" BORDER="0">, describes the slope of the whole post-peak expiratory flow pattern after scaling. RESULTS Compared with FEV(1), the index tPTEF/tE was a poor indicator of airways obstruction (r(2) = 0.15, p = 0.002). Trs showed a strong relationship with the severity of airways obstruction (r(2) = 0.46, p < 0.001). Using f1.gif" BORDER="0">, the postexpiratory profile could be categorized into three shapes, and provided a good indicator of airways obstruction when linear and concave-shaped profiles occurred (r(2) = 0.42, p < 0.001). Convex-shaped flow profiles had to be treated separately and were indicative of normal lung function. CONCLUSIONS In a cross-sectional study of patients with cystic fibrosis, increase in airways resistance above normal is reflected by quantifiable changes in the expiratory airflow pattern.
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Wong LS, Williams EM, Hamilton R, Hahn CE. An IBM PC-based system for the assessment of cardio-respiratory function using oscillating inert gas forcing signals. J Clin Monit Comput 2000; 16:33-43. [PMID: 12578093 DOI: 10.1023/a:1009956810968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE An IBM PC-based real-time data acquisition, monitoring and analysis system was developed for the assessment of cardio-respiratory function, i.e. airway dead space, alveolar volume and pulmonary blood flow, using oscillating inert inspired gas forcing signals. METHODS The forcing gas mixture was generated by an in-house sinusoid gas delivery unit. The system interfaced with a mass spectrometer and an airway flow transducer, and performed real-time tracking of the breath-by-breath end-inspired, end-expired and mixed-expired concentrations. It calculated the cardiorespiratory parameters using two, i.e. continuous and tidal, in-house mathematical models of the lungs. The system's performance was evaluated using a mechanical bench lung, laboratory subjects and awake adults breathing spontaneously. Its predictive accuracy was compared with the measured volumes of the bench lung; single breath CO2 test for airway dead space and N2 washout for alveolar volume in laboratory subjects and awake adults; and thermal dilution technique for pulmonary blood flow in laboratory subjects. RESULTS Close agreements were found between the true and predicted airway dead space, i.e. mean differences of -12.39%, 14.47% and -17.49%, respectively, and that of alveolar volume, i.e. -8.03%, -3.62% and 7.22%, respectively, in the bench lung, laboratory subject and awake adult studies; and that of pulmonary blood flow (-23.81%) in the laboratory subjects using the continuous lung model. Even closer agreements were observed for airway dead space (-5.8%) and alveolar volume (-4.01%) of the bench lung and for pulmonary blood flow (-8.47%) in the laboratory subjects using the tidal lung model. CONCLUSIONS A system was developed to deliver, monitor and analyse on-line, and in real-time, output data from the sinusoid forcing technique. The technique was administered using the system in various subjects, and produced favourable predictions.
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Maudsley G, Williams EM. What lessons can be learned for cancer registration quality assurance from data users? Skin cancer as an example. Int J Epidemiol 1999; 28:809-15. [PMID: 10597975 DOI: 10.1093/ije/28.5.809] [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: 11/13/2022] Open
Abstract
BACKGROUND In cancer registration, data cleaning (i.e. amendments made by data users to datasets released by registries) is potentially informative for quality assurance, but generally underreported. AIM To assess the scope for learning lessons about cancer registration quality assurance from a data user (using skin cancer as the example). METHODS The main design features were: (i) A descriptive study identifying, qualitatively and quantitatively, the breadth, depth, and impact of quality assurance issues raised by a user cleaning Merseyside and Cheshire Cancer Registry skin cancer data. Errors were rectified and pitfalls for interpretation were identified. (ii) A nested validation of morphology and site coding on random samples of cutaneous malignant melanomas, basal cell carcinomas (BCC), and squamous cell carcinomas. The 33132-record dataset comprised: all registered skin lesions, except metastases; most recorded variables (about patient, lesion, treatment, outcome); for Merseyside and Cheshire residents diagnosed 1970-1991. RESULTS (i) Ineligible cases represented 0.3% (97/33132), and were detected best by morphology checks. Most quality assurance issues identified related to local custom and practice, staff training, and computerization, being particularly illustrated by problematic BCC registration practice (e.g. records written over unchallenged by range checks; and idiosyncratic use of variables). (ii) Post-cleaning, morphology coding errors were minimal in the random samples. CONCLUSION There is great scope for data users to contribute to cancer registration quality assurance. Ultimately, the study dataset appeared fit for epidemiological analysis and important quality assurance messages emerged. Shared explicit standard guidelines for data preparation and validation are needed by users, whose insights could and should be better recognized by cancer registries.
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Smikle MF, Barton EN, Morgan OC, Luseko J, Bailey VE, Williams EM. The significance of immune disorder in tropical spastic paraparesis. Hum Antibodies 1999; 9:133-7. [PMID: 10405834] [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
The reports of the occurrence of HTLV-1 infection and/or HTLV-1 associated myelopathy (HAM/tropical spastic paraparesis (TSP) in patients with certain organ-specific and nonorgan-specific autoimmune diseases prompted us to assess the relationship between TSP and humoral autoimmunity. Blood samples from 76 TSP patients, 60 asymptomatic HTLV-1 carriers and 100 HTLV-1 seronegative blood donors were examined for the presence of organ-specific and nonorgan-specific autoantibodies, reactive serological tests for syphilis, immunoglobulin and complement concentrations as well as immunecomplexes. High prevalences of autoantibodies (39/76, 51%), reactive serological tests for syphilis (23/76; 30%), hypergammaglobulinaemia (69/76, 90%) and complement fixing immune complexes (44/76, 58%) were found in the TSP patients. These indicators of immunological disorder were found in statistically significantly lower prevalences in asymptomatic HTLV-1 carriers (12/60, 20%; p < 0.001; 6/60, 10%; p < 0.05; 32/60, 53%; p < 0.001 and 8/60, 13%; p < 0.001, respectively) and HTLV-1 seronegative blood donors (8/100, 8%; p < 0.001; 3/100, 3%; p < 0.001; 15/100, 15%; p < 0.001 and 5/100, 5%; p < 0.001, respectively). The profiles of autoimmune phenomena observed in the patient and control groups revealed that they were associated with TSP rather than mere HTLV-1 infection and consequently pathogenetic significance. The array of immunological features present in TSP was suggestive of autoimmune disease resulting from immune dysfunction. Studies which explore the possible existence of HTLV-1 induced autoantibodies with specificity for antigens of the spinal cord in TSP might be useful in elucidating its pathogenesis.
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Dolan K, Sutton R, Walker SJ, Morris AI, Campbell F, Williams EM. New classification of oesophageal and gastric carcinomas derived from changing patterns in epidemiology. Br J Cancer 1999; 80:834-42. [PMID: 10360663 PMCID: PMC2362302 DOI: 10.1038/sj.bjc.6690429] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The current ICD-O classification of carcinomas of the oesophagus and stomach causes epidemiological and clinical confusion. This study compares the epidemiological and clinical features of each subtype and subsite of adenocarcinomas of the oesophagus and stomach, to assess requirements for a new classification of these carcinomas. Data were extracted with appropriate validity checks on all cases of oesophageal and gastric carcinomas identified throughout the period 1974-1993 by the Merseyside and Cheshire Cancer Registry, which covers a population of 2.5 million. The incidence of adenocarcinomas of the lower oesophagus and cardia trebled in males, and doubled in females, whereas adenocarcinoma of the subcardia region of the stomach declined in both sexes. Adenocarcinomas of the lower oesophagus and of the cardia were similar for median age at diagnosis, male to female ratio, percentage of patients who smoked and survival; both were significantly different from carcinomas of the subcardia in these respects. These data imply that adenocarcinomas of the lower oesophagus and cardia are the same disease. A new subsite classification of oesophageal and gastric carcinomas is proposed that includes the gastro-oesophageal junction as a distinct subsite, to facilitate surveillance, management and research.
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Williams EM, Madgwick RG, Morris MJ. Tidal expired airflow patterns in adults with airway obstruction. Eur Respir J 1998; 12:1118-23. [PMID: 9864007 DOI: 10.1183/09031936.98.12051118] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Earlier studies have shown that time and flow indices derived from tidal expiratory flow patterns can be used to distinguish the severity of airway obstruction. This study was designed to address two aspects of tidal expiratory flow patterns: 1) how do expiratory flow patterns differ between subjects with normal and obstructed airways; and 2) can a sensitive index of airway obstruction be derived from these pattern differences? Tidal expiratory flow patterns from 66 adult subjects with varying degrees of airway obstructive disease with a forced expiratory volume in one second (FEV1) of 20-121% predicted were examined. In each subject, the expired flow pattern from each consecutive breath was scaled and then averaged together to create a single expired pattern. A detailed examination of the scaled flow patterns in 12 subjects (six with normal airways and six with airway obstruction) showed that the shape of the post-peak expiratory flow portion was different in the subjects with airway obstruction. A slope index, S, was derived from the scaled patterns and found to be sensitive to the severity of airway obstruction, correlating with FEV1 (% pred) with r2=0.74 (p<0.05, n=57). The S index also correlated (r2=0.36, p<0.05, n=47) with the functional residual capacity (FRC) (% pred) which was >100% in subjects with severe airway obstruction and lung overinflation. In subjects with normal airways, three further airflow patterns could be distinguished, which were different from the patterns seen in subjects with the severest airway obstruction. Scaled flow patterns from tidal expiration collected from uncoached subjects, can be used to derive an index of airway obstruction.
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Williams EM, Sainsbury MC, Sutton L, Xiong L, Black AM, Whiteley JP, Gavaghan DJ, Hahn CE. Pulmonary blood flow measured by inspiratory inert gas concentration forcing oscillations. RESPIRATION PHYSIOLOGY 1998; 113:47-56. [PMID: 9776550 DOI: 10.1016/s0034-5687(98)00051-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
The aim of this study was to discover if the forced inspired inert gas sinewave technique could be used to measure pulmonary blood flow, using nitrous oxide as the indicator gas, following inotropic stimulation of the heart by dobutamine, in the presence of a constant alveolar ventilation. Cardiac output (range 1-4.5 L min(-1)) was measured in six dogs by thermodilution and by calculation from the sinusoidal expired partial pressures of argon and nitrous oxide using: (i) analytical equations and a conventional continuous ventilation three-compartment lung model, which did not include recirculation; and (ii) a digital simulation tidal ventilation lung model (Gavaghan and Hahn, 1996. Respir. Physiol. 106, 209-221) which was adapted to include nitrous oxide mixed-venous recirculation from a combined single viscera compartment. The continuous ventilation model calculations always underestimated thermodilution cardiac output, with the bias error increasing to almost -1 L min(-1) at the longest forcing periods, 4-5 min. In contrast, the tidal ventilation model calculations were in close agreement to thermodilution cardiac output, with biases of -0.04 and -0.26 L min(-1) at forcing periods of 2 and 3 min, respectively.
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