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Papers by Anca Dragomir

Research paper thumbnail of Examples of exact categories with Serre class and Euler-Poincaré mapping

The author’s preoccupation is to extend D. W. Robinson’s results in abelian categories with Serre... more The author’s preoccupation is to extend D. W. Robinson’s results in abelian categories with Serre class and Euler-Poincaré mapping [Linear Algebra Appl. 29, 413-421 (1980; Zbl 0425.18006)] from abelian categories to exact categories. In this paper he gives a further example of a non- abelian exact category with Serre class and Euler-Poincaré mapping.

Research paper thumbnail of The rank of the composition of two morphisms in exact categories with Serre class

If C is an abelian category with Serre class S and Euler-Poincaré mapping ε, then the Euler-Poinc... more If C is an abelian category with Serre class S and Euler-Poincaré mapping ε, then the Euler-Poincaré rank of a morphism f with Imf∈S is defined as ε(Imf) [see D. W. Robinson, Linear Algebra Appl. 29, 413–421 (1980; Zbl 0425.18006)]. More generally, an exact category ℰ may be considered instead of the abelian category C. For example, the category of partial bijections between sets, which is an exact and inverse category, not being abelian, may be provided with Serre class and Euler-Poincaré mapping. The Euler-Poincaré rank of a morphism f can be defined just as in the abelian case. The purpose of this paper is to give a direct proof of the rank inequality for the composition of two morphisms, in exact categories with Serre class and Euler-Poincaré mapping.

Research paper thumbnail of Knee pain and knee osteoarthritis severity in self-reported task specific disability: the Johnston County Osteoarthritis Project

The Journal of rheumatology, 1997

To evaluate the contributions of radiographic knee osteoarthritis (OA) and knee pain severity to ... more To evaluate the contributions of radiographic knee osteoarthritis (OA) and knee pain severity to self-reported disability performing upper and lower extremity tasks in a rural, population based sample. Data from 1192 African-American and Caucasian participants in the Johnston County Osteoarthritis Project were analyzed with multiple logistic regression to examine the roles of Kellgren-Lawrence radiographic knee OA grade and knee pain severity in self-reported difficulty performing 20 activities of the Health Assessment Questionnaire. Potential confounders included age, sex, race, marital status, education, and body mass index. Forty-three percent reported difficulty performing at least one task. Mild knee pain was independently associated with difficulty performing 16 upper and lower extremity tasks, and moderate/severe knee pain with all 20 tasks, with little change after adjustment (p < 0.0001). In contrast, mild radiographic knee OA was associated with difficulty in only 4 mob...

Research paper thumbnail of Prevalence of knee symptoms and radiographic and symptomatic knee osteoarthritis in African Americans and Caucasians: the Johnston County Osteoarthritis Project

The Journal of rheumatology, 2007

To report contemporary estimates of the prevalence of knee-related osteoarthritis (OA) outcomes i... more To report contemporary estimates of the prevalence of knee-related osteoarthritis (OA) outcomes in African Americans and Caucasians aged > or = 45 years. Weighted prevalence estimates for knee symptoms, radiographic knee OA, symptomatic knee OA, and severe radiographic knee OA were calculated for age, ethnic, and sex subgroups, in 3018 participants (33% African Americans, 38% men) in the baseline examination (1991-97) of The Johnston County Osteoarthritis Project, a population-based study of OA in North Carolina. Radiographic knee OA was defined as Kellgren-Lawrence radiographic grade > or = 2, severe radiographic knee OA as grades 3 and 4, and symptomatic knee OA as knee symptoms in a knee with radiographic OA. Knee symptoms were present in 43%, 28% had radiographic knee OA, 16% had symptomatic knee OA, and 8% had severe radiographic knee OA. Prevalence was higher in older individuals and women. African Americans had slightly higher prevalence of knee symptoms, radiographic k...

Research paper thumbnail of A Geographic Assessment of Health-Care Coverage in Two "Rural" North Carolina Communities

Southeastern Geographer, 1999

ABSTRACT The study shows the value of using basic geographic techniques to examine two key concep... more ABSTRACT The study shows the value of using basic geographic techniques to examine two key concepts of health-care delivery—service coverage and location of a community along a rural-urban continuum. Three types of coverage are discussed for two small North Carolina communities: the availability of physicians of all types, the accessibility to hospitals of all sizes, and the utilization of primary-care physicians. The usefulness of the concept of a rural-urban continuum in helping to define degree of rurality and how this concept affects coverage is demonstrated by looking at two towns midway along the continuum. Although the towns are only nine miles apart, they have very different coverage profiles, indicating that unique local health-care-delivery situations must be taken into account. The study towns do not fit the rural stereotype of poor availability and accessibility, although these two types of coverage could be improved. The micro-scale study of the utilization of primary care physicians revealed that several sociodemographic factors were not important, but that measuring perceived travel time, whether or not people had to be driven to care, perceived health status, and health insurance status were important.

Research paper thumbnail of Potential Risk Factors Associated With Subtypes of Uterine Leiomyomata

Reproductive Sciences, 2010

To compare potential risk factors for uterine leiomyomata (UL) subtypes among premenopausal Afric... more To compare potential risk factors for uterine leiomyomata (UL) subtypes among premenopausal African American and Caucasian women. This cross-sectional study included 986 premenopausal women, aged 35 to 49 years old, from the National Institute of Environmental Health Sciences (NIEHS) Uterine Fibroid Study (UFS). Uterine leiomyomata were subtyped as submucosal, intramural/subserosal, and diffuse, based on ultrasound examinations. For both ethnic groups, age, age at menarche, body mass index, and current physical activity had similar associations across the 3 UL subtypes. Inverse associations with pregnancies after age 24 appeared to be stronger for the submucosal subtype. Current smoking was associated only with diffuse UL (adjusted odds ratio [aOR] = 1.97, 95% CI: 1.11, 3.51 in African Americans, aOR = 3.00, 95% CI: 1.07, 8.38 in Caucasians). Although the 2 focal UL subtypes had similar risk factor profiles, the diffuse UL subtype appeared to have a distinctive risk profile with regard to current smoking. Further study of the diffuse heterogeneity seen with uterine ultrasound is needed.

Research paper thumbnail of Serum cartilage oligomeric matrix protein and clinical signs and symptoms of potential pre-radiographic hip and knee pathology

Osteoarthritis and Cartilage, 2002

Objective: To examine the cross-sectional relationship between serum cartilage oligomeric matrix ... more Objective: To examine the cross-sectional relationship between serum cartilage oligomeric matrix protein (COMP) and hip and knee clinical signs and symptoms in a sample of adults without radiographic hip or knee osteoarthritis (OA). Design: A total of 145 persons with available sera and no evidence of radiographic hip or knee OA (Kellgren-Lawrence grade 0) were randomly selected from the Caucasian participants of the Johnston County Osteoarthritis Project. COMP was quantified by a competitive ELISA assay with a monoclonal antibody 17-C10. Hip and knee clinical signs and symptoms were assessed by physical examination and interview, and their associations with Ln COMP analysed with general linear models. Results: After adjustment for age, gender, body mass index (BMI), and other symptomatic joints, mean Ln COMP was statistically significantly higher among persons with hip-related clinical signs (P=0.018), among those with hip-related symptoms (P=0.046), and among individuals meeting American College of Rheumatology clinical criteria for hip OA (P=0.021). There were no statistically significant associations between any of the knee-related clinical signs and symptoms and Ln COMP. Conclusion: Serum COMP may be useful as a biomarker of pre-radiographic hip joint pathology; its utility as a biomarker of pre-radiographic knee joint pathology is unclear.

Research paper thumbnail of Interpretation of serum C-reactive protein (CRP) levels for cardiovascular disease risk is complicated by race, pulmonary disease, body mass index, gender, and osteoarthritis

Osteoarthritis and Cartilage, 2007

Objective: High-sensitivity C-reactive protein (hsCRP) in serum is used as a marker of risk for c... more Objective: High-sensitivity C-reactive protein (hsCRP) in serum is used as a marker of risk for cardiovascular disease (CVD); however CRP is a non-specific acute phase reactant. We evaluated the association between hsCRP concentrations and the most common form of arthritis, osteoarthritis (OA), and assessed the applicability of hsCRP for CVD risk prediction. Methods: Participants (n ¼ 662) were selected from the population-based Johnston County Osteoarthritis Project, using stratified simple random sampling to achieve balance according to radiographic knee OA status, ethnic group, gender, and age group. The presence and severity of knee and hip OA were determined radiographically. CVD risk was estimated by hsCRP concentration and independently with the Framingham risk algorithm. Results: Serum natural log-transformed hsCRP (ln hsCRP) was higher in African-Americans (P < 0.0001) and women (P < 0.0001), was higher in participants who had chronic pulmonary disease (P ¼ 0.01), hypertension (P < 0.0001), or used pain medications (P ¼ 0.004), and correlated with body mass index (BMI) (r ¼ 0.40, P < 0.0001) and waist circumference (r ¼ 0.33, P < 0.0001), but not with age, CVD, or current smoking. Ln hsCRP was strongly positively associated with all definitions of radiographic OA (rOA; P < 0.0001), but this association was not independent of BMI. Although 183 participants reported no CVD and were classified as low risk by the Framingham CVD score, 61% of them were classified as moderate or high risk for CVD using hsCRP; this proportion designated high risk for CVD on the basis of hsCRP consisted primarily of women (P < 0.05) and individuals with OA (P < 0.01). Conclusions: The pathogenic significance of hsCRP elevations in this subgroup is unclear. Serum hsCRP for predicting risk of CVD is confounded by obesity, ethnicity, gender and comorbidities.

Research paper thumbnail of Identification of an urinary metabolite profile associated with osteoarthritis

Osteoarthritis and Cartilage, 2005

Objective: Osteoarthritis (OA) is one of the most common diseases among the elderly. The main cha... more Objective: Osteoarthritis (OA) is one of the most common diseases among the elderly. The main characteristic is the progressive destruction of articular cartilage. We lack quantitative and sensitive biomarkers for OA to detect changes in the joints in an early stage of the disease. In this study, we investigated whether a urinary metabolite profile could be found that could serve as a diagnostic biomarker for OA in humans. We also compared the profile we obtained previously in the guinea pig spontaneous OA model. Methods: Urine samples of 92 participants (47 non-OA controls and 45 individuals with radiographic OA of the knees or hips) were selected from the Johnston County Osteoarthritis Project (North Carolina, USA). Participants ranged in age from 60 to 84 years. Samples were measured by 1 H nuclear magnetic resonance spectroscopy (NMR) with subsequent principal component discriminant analysis and partial least squares regression analysis. Results: Differences were observed between urine NMR spectra of OA cases and controls (P ! 0.001 for both male and female subjects). A metabolite profile could be determined which was strongly associated with OA. This profile largely resembled the profile previously identified for guinea pigs with OA (w40 out of the w125 signals of the human profile were present in the guinea pig profile as well). A correlation was found between the metabolite profile and radiographic OA severity (R 2 Z 0.82 (male); R 2 Z 0.93 (female)). Conclusion: This study showed that a urine metabolite profile may serve as a novel discriminating biomarker of OA.

Research paper thumbnail of Uterine Leiomyomata Associated with Self-Reported Stress Urinary Incontinence

Journal of Women's Health, 2010

Aims: To investigate the association between the presence and characteristics of uterine leiomyom... more Aims: To investigate the association between the presence and characteristics of uterine leiomyomata (UL) and self-reported stress urinary incontinence (SUI). Methods: The study included 836 premenopausal participants (474 African American and 362 Caucasian) in the National Institute of Environmental Health Sciences (NIEHS) Uterine Fibroid Study. UL were characterized at baseline with ultrasound screening, and SUI was assessed at follow-up (after 4 years, on average). Linear risk models were used to estimate adjusted prevalence differences (aPD) and 95% confidence intervals (CI), controlling for age, ethnicity, body mass index (BMI), and number of deliveries. Results: Compared with women without UL, SUI prevalence was higher among women with any UL (aPD ¼ 7.4%, 95% CI 0.4-14.3) and women with UL 2-4 cm (aPD ¼ 9.6%, 95% CI 1.3-17.9). Marginally significant results were found for the presence of UL !4 cm and anterior UL !2 cm. Conclusions: The observed 7% increase in prevalence of this common condition for women with UL is of clinical importance. Further research is needed before concluding that treatment for larger UL might enhance SUI treatment in some women.

Research paper thumbnail of Informatics and data quality at collaborative multicenter Breast and Colon Cancer Family Registries

Journal of the American Medical Informatics Association, 2012

Quality control and harmonization of data is a vital and challenging undertaking for any successf... more Quality control and harmonization of data is a vital and challenging undertaking for any successful data coordination center and a responsibility shared between the multiple sites that produce, integrate, and utilize the data. Here we describe a coordinated effort between scientists and data managers in the Cancer Family Registries to implement a data governance infrastructure consisting of both organizational and technical solutions. The technical solution uses a rule-based validation system that facilitates error detection and correction for data centers submitting data to a central informatics database. Validation rules comprise both standard checks on allowable values and a crosscheck of related database elements for logical and scientific consistency. Evaluation over a 2-year timeframe showed a significant decrease in the number of errors in the database and a concurrent increase in data consistency and accuracy.

Research paper thumbnail of Prevalence of Hip Symptoms and Radiographic and Symptomatic Hip Osteoarthritis in African Americans and Caucasians: The Johnston County Osteoarthritis Project

The Journal of Rheumatology, 2009

Objective.To report contemporary estimates of the prevalence of hip-related osteoarthritis (OA) o... more Objective.To report contemporary estimates of the prevalence of hip-related osteoarthritis (OA) outcomes in African Americans and Caucasians aged ≥ 45 years.Methods.Weighted prevalence estimates and their corresponding 95% confidence intervals for hip symptoms, radiographic hip OA, symptomatic hip OA, and severe radiographic hip OA were calculated using SUDAAN® for age, race, and sex subgroups among 3068 participants (33% African Americans, 38% men) in the baseline examination (1991–97) of The Johnston County Osteoarthritis Project, a population-based study of OA in North Carolina. Radiographic hip OA was defined as Kellgren-Lawrence radiographic grade ≥ 2, moderate/severe radiographic hip OA as grades 3 and 4, and symptomatic hip OA as hip symptoms in a hip with radiographic OA.Results.Hip symptoms were present in 36%; 28% had radiographic hip OA; nearly 10% had symptomatic hip OA; and 2.5% had moderate/severe radiographic hip OA. Prevalence of all 4 outcomes was higher in older in...

Research paper thumbnail of P1-35 On the use of empirical likelihood based methods to achieve balance on measured confounders

Journal of Epidemiology & Community Health, 2011

interaction between famine exposure and genetic risk scores with regard to BMI outcomes. Analyses... more interaction between famine exposure and genetic risk scores with regard to BMI outcomes. Analyses with weighted risk scores confirm these patterns. Common genetic variants related to BMI do not explain the association between prenatal famine and adult BMI in our study population.

Research paper thumbnail of Ethnic and sex differences in serum levels of cartilage oligomeric matrix protein: The Johnston county osteoarthritis project

Arthritis & Rheumatism, 2003

Previous descriptions of potential biomarkers of osteoarthritis (OA) have been limited to Caucasi... more Previous descriptions of potential biomarkers of osteoarthritis (OA) have been limited to Caucasians. In the present study, we examined associations between serum levels of cartilage oligomeric matrix protein (COMP) and ethnicity (African American or Caucasian) and sex in the Johnston County Osteoarthritis Project, a population-based study of OA in rural North Carolina. Methods. All African Americans and a randomly selected sample of Caucasians who had available sera and either no radiographic evidence of knee or hip OA according to the Kellgren/Lawrence (K/L) system (K/L grade 0) or radiographic evidence of knee OA (K/L grade 2 or higher) were included. Serum COMP levels were quantified by sandwich enzyme-linked immunosorbent assay, using monoclonal antibodies 16-F12 and 17-C10. Linear regression models were used to assess relationships between serum levels of natural logtransformed COMP (ln COMP) and ethnicity and sex, controlling for age, height, body mass index (BMI), radiographic OA, and the presence of other symptomatic joints. Radiographic OA was defined in separate models as the presence, severity, and laterality of radiographic knee OA, the co-occurrence of radiographic knee and hip OA, and the number of knees and hips with radiographic OA. Results. The 769 subjects in the study sample had a mean ؎ SD age of 62 ؎ 10.3 years. Levels of ln COMP were associated with age, BMI, and all definitions of radiographic OA (P ‫؍‬ 0.0001), and varied by ethnicity and sex. In adjusted models, ln COMP was higher in African American women than in Caucasian women (P ‫؍‬ 0.003) and higher in Caucasian men than Caucasian women (P ‫؍‬ 0.0001). There were no statistically significant differences in serum ln COMP levels between African American men and women. Conclusion. Serum COMP levels vary by ethnicity and sex. These factors should be considered in the derivation of standards using this, and possibly other, potential biomarkers of OA. Cartilage oligomeric matrix protein (COMP) is a 524-kd pentameric glycoprotein that is found predominantly in cartilage, but is also present in ligament, tendon, meniscus, and synovium (1-3). Elevated serum levels of COMP have been found in persons with knee osteoarthritis (OA) compared with healthy individuals (2), in persons with OA-related type II collagen gene mutations (4), in those with knee OA with synovitis compared with those with knee OA without synovitis (3), and in those with systemic inflammatory arthropathy due to rheumatoid arthritis (5,6). Using monoclonal antibody 17-C10 in an inhibition enzyme-linked immu

Research paper thumbnail of Serum cartilage oligomeric matrix protein reflects osteoarthritis presence and severity: The Johnston county osteoarthritis project

Arthritis & Rheumatism, 1999

Aim of the work: The objective of our study was to determine the utility of serum cartilage oligo... more Aim of the work: The objective of our study was to determine the utility of serum cartilage oligomeric matrix protein (COMP) as a serum biomarker for hemophilic arthropathy and to evaluate the degree of joint damage radiologically using plain X-ray and functionally using functional independence score of hemophilia (FISH) and to study their relation with COMP. Patients and methods: The study was carried out on 30 boys with hemophilic arthropathy (group I) and 20 healthy boys as control (group II). All hemophiliacs patients were scored for FISH and radiological changes (Pettersson's score). Factor activity level was measured in group I while COMP was measured in both groups. Results: The patients' age ranged from 6 to 16 years (mean 10.6 ± 2.7 years). The knee was the most commonly affected joint (83.3%). Fifteen patients (50%) had severe hemophilia, 7 had moderate and 8 had mild hemophilia. Mean serum levels of COMP in hemophilic patients (529 ± 288.1 ng/ml) were significantly higher than in control (285 ± 63.2 ng/ml) (p = 0.014). The COMP level was significantly higher in patients with severe hemophilia compared to those with moderate or mild disease (p < 0.001). The serum COMP significantly correlated with joint space narrowing (r = 0.64, p < 0.001) and with the total Pettersson score (r = 0.42, p = 0.02) and negatively with the FISH score (r = À0.44, p = 0.016). Conclusions: Serum COMP level is indicative of the amount of joint damage in patients with hemophilic arthropathy. The combined scoring of functional independence and Pettersson score in addition to serum levels of COMP give a good overview of the degree of hemophilic arthropathy.

Research paper thumbnail of Self-reported functional status in osteoarthritis of the knee in a rural southern community: The role of sociodemographic factors, obesity, and knee pain

Arthritis Care & Research, 1996

This study examined the roles of sociodemographic factors (age, race, gender, education, marital ... more This study examined the roles of sociodemographic factors (age, race, gender, education, marital status), obesity, and severity of radiographic knee osteoarthritis (OA) and knee pain on self-reported functional status. Methods. The sample included 1,272 African-American and Caucasian individuals, aged 45years or older, from the Johnston County Osteoarthritis Project. Analysis of variance was used to assess variation in mean Health Assessment Questionnaire (HAQ) scores by the above variables. Results. Mean HAQ scores differed by severity of radiographic knee OA and knee pain, obesity, and all demographic factors (P < O.OOOl), except race. Only age, female sex, obesity, and knee pain severity were independent effects (P < 0.0009). Disability associated

Research paper thumbnail of Ethnic differences in self-reported functional status in the rural south: The johnston county osteoarthritis project

Arthritis Care & Research, 1996

We examined ethnic differences in selfreported functional status in a rural, population-based sam... more We examined ethnic differences in selfreported functional status in a rural, population-based sample in North Carolina. Methods. Data from 1,197 African-American and Caucasian participants, aged 45 and older, in the Johnston County Osteoarthritis Project were analyzed using multiple logistic regression to examine ethnic differences in difficulty pegorming tasks of the Health Assessment Questionnaire (H A 0 and in risk factor profiles associated with difficulty. Results. Forty-three percent reported dificulty in one or more HAQ tasks. African-Americans were more likely than Caucasians to report diffi'culty performing 3 tasks (P < 0.04); these differences were minimal after adjustment for confounders. For some tasks, risk factor profiles included body mass index in African-Americans only, and age and female gender more often in

Research paper thumbnail of Application of the Abridged SimSmoke model to four Eastern Mediterranean countries

Tobacco control, Jan 16, 2015

The WHO established the MPOWER policy package to boost the implementation of the WHO Framework Co... more The WHO established the MPOWER policy package to boost the implementation of the WHO Framework Convention for Tobacco Control (WHO FCTC) in 2008 and to provide practical guidance on policies effective at reducing smoking rates. An easily applied Abridged SimSmoke was developed to help countries gauge the effect of these policies using data from the WHO MPOWER/WHO Report (MPOWER Report) and is applied to four Eastern Mediterranean countries. The number of smokers in a country is calculated using the country's smoking prevalence and population. Policy effect sizes, based on previously validated SimSmoke models, are applied to the smoker populations to determine the reduction in the number of smokers resulting from implementing policies. The number of smoking-attributable deaths is derived based on findings that half of those smokers alive today will die from smoking. Within 40 years, implementing the complete set of MPOWER policies is projected to reduce smoking prevalence by 29% ...

Research paper thumbnail of Examples of exact categories with Serre class and Euler-Poincaré mapping

The author’s preoccupation is to extend D. W. Robinson’s results in abelian categories with Serre... more The author’s preoccupation is to extend D. W. Robinson’s results in abelian categories with Serre class and Euler-Poincaré mapping [Linear Algebra Appl. 29, 413-421 (1980; Zbl 0425.18006)] from abelian categories to exact categories. In this paper he gives a further example of a non- abelian exact category with Serre class and Euler-Poincaré mapping.

Research paper thumbnail of The rank of the composition of two morphisms in exact categories with Serre class

If C is an abelian category with Serre class S and Euler-Poincaré mapping ε, then the Euler-Poinc... more If C is an abelian category with Serre class S and Euler-Poincaré mapping ε, then the Euler-Poincaré rank of a morphism f with Imf∈S is defined as ε(Imf) [see D. W. Robinson, Linear Algebra Appl. 29, 413–421 (1980; Zbl 0425.18006)]. More generally, an exact category ℰ may be considered instead of the abelian category C. For example, the category of partial bijections between sets, which is an exact and inverse category, not being abelian, may be provided with Serre class and Euler-Poincaré mapping. The Euler-Poincaré rank of a morphism f can be defined just as in the abelian case. The purpose of this paper is to give a direct proof of the rank inequality for the composition of two morphisms, in exact categories with Serre class and Euler-Poincaré mapping.

Research paper thumbnail of Knee pain and knee osteoarthritis severity in self-reported task specific disability: the Johnston County Osteoarthritis Project

The Journal of rheumatology, 1997

To evaluate the contributions of radiographic knee osteoarthritis (OA) and knee pain severity to ... more To evaluate the contributions of radiographic knee osteoarthritis (OA) and knee pain severity to self-reported disability performing upper and lower extremity tasks in a rural, population based sample. Data from 1192 African-American and Caucasian participants in the Johnston County Osteoarthritis Project were analyzed with multiple logistic regression to examine the roles of Kellgren-Lawrence radiographic knee OA grade and knee pain severity in self-reported difficulty performing 20 activities of the Health Assessment Questionnaire. Potential confounders included age, sex, race, marital status, education, and body mass index. Forty-three percent reported difficulty performing at least one task. Mild knee pain was independently associated with difficulty performing 16 upper and lower extremity tasks, and moderate/severe knee pain with all 20 tasks, with little change after adjustment (p < 0.0001). In contrast, mild radiographic knee OA was associated with difficulty in only 4 mob...

Research paper thumbnail of Prevalence of knee symptoms and radiographic and symptomatic knee osteoarthritis in African Americans and Caucasians: the Johnston County Osteoarthritis Project

The Journal of rheumatology, 2007

To report contemporary estimates of the prevalence of knee-related osteoarthritis (OA) outcomes i... more To report contemporary estimates of the prevalence of knee-related osteoarthritis (OA) outcomes in African Americans and Caucasians aged > or = 45 years. Weighted prevalence estimates for knee symptoms, radiographic knee OA, symptomatic knee OA, and severe radiographic knee OA were calculated for age, ethnic, and sex subgroups, in 3018 participants (33% African Americans, 38% men) in the baseline examination (1991-97) of The Johnston County Osteoarthritis Project, a population-based study of OA in North Carolina. Radiographic knee OA was defined as Kellgren-Lawrence radiographic grade > or = 2, severe radiographic knee OA as grades 3 and 4, and symptomatic knee OA as knee symptoms in a knee with radiographic OA. Knee symptoms were present in 43%, 28% had radiographic knee OA, 16% had symptomatic knee OA, and 8% had severe radiographic knee OA. Prevalence was higher in older individuals and women. African Americans had slightly higher prevalence of knee symptoms, radiographic k...

Research paper thumbnail of A Geographic Assessment of Health-Care Coverage in Two "Rural" North Carolina Communities

Southeastern Geographer, 1999

ABSTRACT The study shows the value of using basic geographic techniques to examine two key concep... more ABSTRACT The study shows the value of using basic geographic techniques to examine two key concepts of health-care delivery—service coverage and location of a community along a rural-urban continuum. Three types of coverage are discussed for two small North Carolina communities: the availability of physicians of all types, the accessibility to hospitals of all sizes, and the utilization of primary-care physicians. The usefulness of the concept of a rural-urban continuum in helping to define degree of rurality and how this concept affects coverage is demonstrated by looking at two towns midway along the continuum. Although the towns are only nine miles apart, they have very different coverage profiles, indicating that unique local health-care-delivery situations must be taken into account. The study towns do not fit the rural stereotype of poor availability and accessibility, although these two types of coverage could be improved. The micro-scale study of the utilization of primary care physicians revealed that several sociodemographic factors were not important, but that measuring perceived travel time, whether or not people had to be driven to care, perceived health status, and health insurance status were important.

Research paper thumbnail of Potential Risk Factors Associated With Subtypes of Uterine Leiomyomata

Reproductive Sciences, 2010

To compare potential risk factors for uterine leiomyomata (UL) subtypes among premenopausal Afric... more To compare potential risk factors for uterine leiomyomata (UL) subtypes among premenopausal African American and Caucasian women. This cross-sectional study included 986 premenopausal women, aged 35 to 49 years old, from the National Institute of Environmental Health Sciences (NIEHS) Uterine Fibroid Study (UFS). Uterine leiomyomata were subtyped as submucosal, intramural/subserosal, and diffuse, based on ultrasound examinations. For both ethnic groups, age, age at menarche, body mass index, and current physical activity had similar associations across the 3 UL subtypes. Inverse associations with pregnancies after age 24 appeared to be stronger for the submucosal subtype. Current smoking was associated only with diffuse UL (adjusted odds ratio [aOR] = 1.97, 95% CI: 1.11, 3.51 in African Americans, aOR = 3.00, 95% CI: 1.07, 8.38 in Caucasians). Although the 2 focal UL subtypes had similar risk factor profiles, the diffuse UL subtype appeared to have a distinctive risk profile with regard to current smoking. Further study of the diffuse heterogeneity seen with uterine ultrasound is needed.

Research paper thumbnail of Serum cartilage oligomeric matrix protein and clinical signs and symptoms of potential pre-radiographic hip and knee pathology

Osteoarthritis and Cartilage, 2002

Objective: To examine the cross-sectional relationship between serum cartilage oligomeric matrix ... more Objective: To examine the cross-sectional relationship between serum cartilage oligomeric matrix protein (COMP) and hip and knee clinical signs and symptoms in a sample of adults without radiographic hip or knee osteoarthritis (OA). Design: A total of 145 persons with available sera and no evidence of radiographic hip or knee OA (Kellgren-Lawrence grade 0) were randomly selected from the Caucasian participants of the Johnston County Osteoarthritis Project. COMP was quantified by a competitive ELISA assay with a monoclonal antibody 17-C10. Hip and knee clinical signs and symptoms were assessed by physical examination and interview, and their associations with Ln COMP analysed with general linear models. Results: After adjustment for age, gender, body mass index (BMI), and other symptomatic joints, mean Ln COMP was statistically significantly higher among persons with hip-related clinical signs (P=0.018), among those with hip-related symptoms (P=0.046), and among individuals meeting American College of Rheumatology clinical criteria for hip OA (P=0.021). There were no statistically significant associations between any of the knee-related clinical signs and symptoms and Ln COMP. Conclusion: Serum COMP may be useful as a biomarker of pre-radiographic hip joint pathology; its utility as a biomarker of pre-radiographic knee joint pathology is unclear.

Research paper thumbnail of Interpretation of serum C-reactive protein (CRP) levels for cardiovascular disease risk is complicated by race, pulmonary disease, body mass index, gender, and osteoarthritis

Osteoarthritis and Cartilage, 2007

Objective: High-sensitivity C-reactive protein (hsCRP) in serum is used as a marker of risk for c... more Objective: High-sensitivity C-reactive protein (hsCRP) in serum is used as a marker of risk for cardiovascular disease (CVD); however CRP is a non-specific acute phase reactant. We evaluated the association between hsCRP concentrations and the most common form of arthritis, osteoarthritis (OA), and assessed the applicability of hsCRP for CVD risk prediction. Methods: Participants (n ¼ 662) were selected from the population-based Johnston County Osteoarthritis Project, using stratified simple random sampling to achieve balance according to radiographic knee OA status, ethnic group, gender, and age group. The presence and severity of knee and hip OA were determined radiographically. CVD risk was estimated by hsCRP concentration and independently with the Framingham risk algorithm. Results: Serum natural log-transformed hsCRP (ln hsCRP) was higher in African-Americans (P < 0.0001) and women (P < 0.0001), was higher in participants who had chronic pulmonary disease (P ¼ 0.01), hypertension (P < 0.0001), or used pain medications (P ¼ 0.004), and correlated with body mass index (BMI) (r ¼ 0.40, P < 0.0001) and waist circumference (r ¼ 0.33, P < 0.0001), but not with age, CVD, or current smoking. Ln hsCRP was strongly positively associated with all definitions of radiographic OA (rOA; P < 0.0001), but this association was not independent of BMI. Although 183 participants reported no CVD and were classified as low risk by the Framingham CVD score, 61% of them were classified as moderate or high risk for CVD using hsCRP; this proportion designated high risk for CVD on the basis of hsCRP consisted primarily of women (P < 0.05) and individuals with OA (P < 0.01). Conclusions: The pathogenic significance of hsCRP elevations in this subgroup is unclear. Serum hsCRP for predicting risk of CVD is confounded by obesity, ethnicity, gender and comorbidities.

Research paper thumbnail of Identification of an urinary metabolite profile associated with osteoarthritis

Osteoarthritis and Cartilage, 2005

Objective: Osteoarthritis (OA) is one of the most common diseases among the elderly. The main cha... more Objective: Osteoarthritis (OA) is one of the most common diseases among the elderly. The main characteristic is the progressive destruction of articular cartilage. We lack quantitative and sensitive biomarkers for OA to detect changes in the joints in an early stage of the disease. In this study, we investigated whether a urinary metabolite profile could be found that could serve as a diagnostic biomarker for OA in humans. We also compared the profile we obtained previously in the guinea pig spontaneous OA model. Methods: Urine samples of 92 participants (47 non-OA controls and 45 individuals with radiographic OA of the knees or hips) were selected from the Johnston County Osteoarthritis Project (North Carolina, USA). Participants ranged in age from 60 to 84 years. Samples were measured by 1 H nuclear magnetic resonance spectroscopy (NMR) with subsequent principal component discriminant analysis and partial least squares regression analysis. Results: Differences were observed between urine NMR spectra of OA cases and controls (P ! 0.001 for both male and female subjects). A metabolite profile could be determined which was strongly associated with OA. This profile largely resembled the profile previously identified for guinea pigs with OA (w40 out of the w125 signals of the human profile were present in the guinea pig profile as well). A correlation was found between the metabolite profile and radiographic OA severity (R 2 Z 0.82 (male); R 2 Z 0.93 (female)). Conclusion: This study showed that a urine metabolite profile may serve as a novel discriminating biomarker of OA.

Research paper thumbnail of Uterine Leiomyomata Associated with Self-Reported Stress Urinary Incontinence

Journal of Women's Health, 2010

Aims: To investigate the association between the presence and characteristics of uterine leiomyom... more Aims: To investigate the association between the presence and characteristics of uterine leiomyomata (UL) and self-reported stress urinary incontinence (SUI). Methods: The study included 836 premenopausal participants (474 African American and 362 Caucasian) in the National Institute of Environmental Health Sciences (NIEHS) Uterine Fibroid Study. UL were characterized at baseline with ultrasound screening, and SUI was assessed at follow-up (after 4 years, on average). Linear risk models were used to estimate adjusted prevalence differences (aPD) and 95% confidence intervals (CI), controlling for age, ethnicity, body mass index (BMI), and number of deliveries. Results: Compared with women without UL, SUI prevalence was higher among women with any UL (aPD ¼ 7.4%, 95% CI 0.4-14.3) and women with UL 2-4 cm (aPD ¼ 9.6%, 95% CI 1.3-17.9). Marginally significant results were found for the presence of UL !4 cm and anterior UL !2 cm. Conclusions: The observed 7% increase in prevalence of this common condition for women with UL is of clinical importance. Further research is needed before concluding that treatment for larger UL might enhance SUI treatment in some women.

Research paper thumbnail of Informatics and data quality at collaborative multicenter Breast and Colon Cancer Family Registries

Journal of the American Medical Informatics Association, 2012

Quality control and harmonization of data is a vital and challenging undertaking for any successf... more Quality control and harmonization of data is a vital and challenging undertaking for any successful data coordination center and a responsibility shared between the multiple sites that produce, integrate, and utilize the data. Here we describe a coordinated effort between scientists and data managers in the Cancer Family Registries to implement a data governance infrastructure consisting of both organizational and technical solutions. The technical solution uses a rule-based validation system that facilitates error detection and correction for data centers submitting data to a central informatics database. Validation rules comprise both standard checks on allowable values and a crosscheck of related database elements for logical and scientific consistency. Evaluation over a 2-year timeframe showed a significant decrease in the number of errors in the database and a concurrent increase in data consistency and accuracy.

Research paper thumbnail of Prevalence of Hip Symptoms and Radiographic and Symptomatic Hip Osteoarthritis in African Americans and Caucasians: The Johnston County Osteoarthritis Project

The Journal of Rheumatology, 2009

Objective.To report contemporary estimates of the prevalence of hip-related osteoarthritis (OA) o... more Objective.To report contemporary estimates of the prevalence of hip-related osteoarthritis (OA) outcomes in African Americans and Caucasians aged ≥ 45 years.Methods.Weighted prevalence estimates and their corresponding 95% confidence intervals for hip symptoms, radiographic hip OA, symptomatic hip OA, and severe radiographic hip OA were calculated using SUDAAN® for age, race, and sex subgroups among 3068 participants (33% African Americans, 38% men) in the baseline examination (1991–97) of The Johnston County Osteoarthritis Project, a population-based study of OA in North Carolina. Radiographic hip OA was defined as Kellgren-Lawrence radiographic grade ≥ 2, moderate/severe radiographic hip OA as grades 3 and 4, and symptomatic hip OA as hip symptoms in a hip with radiographic OA.Results.Hip symptoms were present in 36%; 28% had radiographic hip OA; nearly 10% had symptomatic hip OA; and 2.5% had moderate/severe radiographic hip OA. Prevalence of all 4 outcomes was higher in older in...

Research paper thumbnail of P1-35 On the use of empirical likelihood based methods to achieve balance on measured confounders

Journal of Epidemiology & Community Health, 2011

interaction between famine exposure and genetic risk scores with regard to BMI outcomes. Analyses... more interaction between famine exposure and genetic risk scores with regard to BMI outcomes. Analyses with weighted risk scores confirm these patterns. Common genetic variants related to BMI do not explain the association between prenatal famine and adult BMI in our study population.

Research paper thumbnail of Ethnic and sex differences in serum levels of cartilage oligomeric matrix protein: The Johnston county osteoarthritis project

Arthritis & Rheumatism, 2003

Previous descriptions of potential biomarkers of osteoarthritis (OA) have been limited to Caucasi... more Previous descriptions of potential biomarkers of osteoarthritis (OA) have been limited to Caucasians. In the present study, we examined associations between serum levels of cartilage oligomeric matrix protein (COMP) and ethnicity (African American or Caucasian) and sex in the Johnston County Osteoarthritis Project, a population-based study of OA in rural North Carolina. Methods. All African Americans and a randomly selected sample of Caucasians who had available sera and either no radiographic evidence of knee or hip OA according to the Kellgren/Lawrence (K/L) system (K/L grade 0) or radiographic evidence of knee OA (K/L grade 2 or higher) were included. Serum COMP levels were quantified by sandwich enzyme-linked immunosorbent assay, using monoclonal antibodies 16-F12 and 17-C10. Linear regression models were used to assess relationships between serum levels of natural logtransformed COMP (ln COMP) and ethnicity and sex, controlling for age, height, body mass index (BMI), radiographic OA, and the presence of other symptomatic joints. Radiographic OA was defined in separate models as the presence, severity, and laterality of radiographic knee OA, the co-occurrence of radiographic knee and hip OA, and the number of knees and hips with radiographic OA. Results. The 769 subjects in the study sample had a mean ؎ SD age of 62 ؎ 10.3 years. Levels of ln COMP were associated with age, BMI, and all definitions of radiographic OA (P ‫؍‬ 0.0001), and varied by ethnicity and sex. In adjusted models, ln COMP was higher in African American women than in Caucasian women (P ‫؍‬ 0.003) and higher in Caucasian men than Caucasian women (P ‫؍‬ 0.0001). There were no statistically significant differences in serum ln COMP levels between African American men and women. Conclusion. Serum COMP levels vary by ethnicity and sex. These factors should be considered in the derivation of standards using this, and possibly other, potential biomarkers of OA. Cartilage oligomeric matrix protein (COMP) is a 524-kd pentameric glycoprotein that is found predominantly in cartilage, but is also present in ligament, tendon, meniscus, and synovium (1-3). Elevated serum levels of COMP have been found in persons with knee osteoarthritis (OA) compared with healthy individuals (2), in persons with OA-related type II collagen gene mutations (4), in those with knee OA with synovitis compared with those with knee OA without synovitis (3), and in those with systemic inflammatory arthropathy due to rheumatoid arthritis (5,6). Using monoclonal antibody 17-C10 in an inhibition enzyme-linked immu

Research paper thumbnail of Serum cartilage oligomeric matrix protein reflects osteoarthritis presence and severity: The Johnston county osteoarthritis project

Arthritis & Rheumatism, 1999

Aim of the work: The objective of our study was to determine the utility of serum cartilage oligo... more Aim of the work: The objective of our study was to determine the utility of serum cartilage oligomeric matrix protein (COMP) as a serum biomarker for hemophilic arthropathy and to evaluate the degree of joint damage radiologically using plain X-ray and functionally using functional independence score of hemophilia (FISH) and to study their relation with COMP. Patients and methods: The study was carried out on 30 boys with hemophilic arthropathy (group I) and 20 healthy boys as control (group II). All hemophiliacs patients were scored for FISH and radiological changes (Pettersson's score). Factor activity level was measured in group I while COMP was measured in both groups. Results: The patients' age ranged from 6 to 16 years (mean 10.6 ± 2.7 years). The knee was the most commonly affected joint (83.3%). Fifteen patients (50%) had severe hemophilia, 7 had moderate and 8 had mild hemophilia. Mean serum levels of COMP in hemophilic patients (529 ± 288.1 ng/ml) were significantly higher than in control (285 ± 63.2 ng/ml) (p = 0.014). The COMP level was significantly higher in patients with severe hemophilia compared to those with moderate or mild disease (p < 0.001). The serum COMP significantly correlated with joint space narrowing (r = 0.64, p < 0.001) and with the total Pettersson score (r = 0.42, p = 0.02) and negatively with the FISH score (r = À0.44, p = 0.016). Conclusions: Serum COMP level is indicative of the amount of joint damage in patients with hemophilic arthropathy. The combined scoring of functional independence and Pettersson score in addition to serum levels of COMP give a good overview of the degree of hemophilic arthropathy.

Research paper thumbnail of Self-reported functional status in osteoarthritis of the knee in a rural southern community: The role of sociodemographic factors, obesity, and knee pain

Arthritis Care & Research, 1996

This study examined the roles of sociodemographic factors (age, race, gender, education, marital ... more This study examined the roles of sociodemographic factors (age, race, gender, education, marital status), obesity, and severity of radiographic knee osteoarthritis (OA) and knee pain on self-reported functional status. Methods. The sample included 1,272 African-American and Caucasian individuals, aged 45years or older, from the Johnston County Osteoarthritis Project. Analysis of variance was used to assess variation in mean Health Assessment Questionnaire (HAQ) scores by the above variables. Results. Mean HAQ scores differed by severity of radiographic knee OA and knee pain, obesity, and all demographic factors (P < O.OOOl), except race. Only age, female sex, obesity, and knee pain severity were independent effects (P < 0.0009). Disability associated

Research paper thumbnail of Ethnic differences in self-reported functional status in the rural south: The johnston county osteoarthritis project

Arthritis Care & Research, 1996

We examined ethnic differences in selfreported functional status in a rural, population-based sam... more We examined ethnic differences in selfreported functional status in a rural, population-based sample in North Carolina. Methods. Data from 1,197 African-American and Caucasian participants, aged 45 and older, in the Johnston County Osteoarthritis Project were analyzed using multiple logistic regression to examine ethnic differences in difficulty pegorming tasks of the Health Assessment Questionnaire (H A 0 and in risk factor profiles associated with difficulty. Results. Forty-three percent reported dificulty in one or more HAQ tasks. African-Americans were more likely than Caucasians to report diffi'culty performing 3 tasks (P < 0.04); these differences were minimal after adjustment for confounders. For some tasks, risk factor profiles included body mass index in African-Americans only, and age and female gender more often in

Research paper thumbnail of Application of the Abridged SimSmoke model to four Eastern Mediterranean countries

Tobacco control, Jan 16, 2015

The WHO established the MPOWER policy package to boost the implementation of the WHO Framework Co... more The WHO established the MPOWER policy package to boost the implementation of the WHO Framework Convention for Tobacco Control (WHO FCTC) in 2008 and to provide practical guidance on policies effective at reducing smoking rates. An easily applied Abridged SimSmoke was developed to help countries gauge the effect of these policies using data from the WHO MPOWER/WHO Report (MPOWER Report) and is applied to four Eastern Mediterranean countries. The number of smokers in a country is calculated using the country's smoking prevalence and population. Policy effect sizes, based on previously validated SimSmoke models, are applied to the smoker populations to determine the reduction in the number of smokers resulting from implementing policies. The number of smoking-attributable deaths is derived based on findings that half of those smokers alive today will die from smoking. Within 40 years, implementing the complete set of MPOWER policies is projected to reduce smoking prevalence by 29% ...