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Biomedical subjects

C K Kwoh

Publications and source records attributed to C K Kwoh.

At least 19 recordsLinked to original sources
PubMed2001

Variation in perceptions of treatment and self-care practices in elderly with osteoarthritis: a comparison between African American and white patients.

OBJECTIVE: To compare elderly African American and white patients with osteoarthritis of the knee or hip with respect to their perceptions of the efficacy of traditional and complementary treatments and their self-care practices. METHODS: An observational, cross-sectional study design using structured questionnaires was employed. RESULTS: The sample consisted of 593 patients (44% African American and 56% white). The 2 groups were comparable with respect to age, disease severity or functional status, and comorbidities. African Americans were more likely than whites to report lower educational level and household income. African Americans were also more likely than whites to perceive various traditional and complementary care modalities as efficacious. However, they were less likely than whites to perceive joint replacement therapy as efficacious (odds ratio 0.52, 95% confidence interval 0.28-0.98). African American patients were more likely than white patients to rely on self-care measures for their arthritis. CONCLUSION: African American and white patients with osteoarthritis of the knee or hip differ with respect to their perceptions of traditional and complementary treatments for arthritis and their self-care practices.

Black or African American↗
PubMed2001

Rheumatology patient and physician concordance with respect to important health and symptom status outcomes.

OBJECTIVE: In chronic diseases such as arthritis, patients' priorities and values are of prime importance in the measurement of outcome. Relatively few indices take this into account. We sought to identify individual rheumatology patients' choices for important health and symptom status outcomes and assess physicians' ability to detect them. METHODS: A cross-sectional, observational study design was used to examine rheumatology patients' choices for important health and symptom status outcomes. A descriptive summary of patients' choices of "most important" health and symptom status outcomes was compiled. The sensitivity and specificity of physicians' ability to detect their patients' choices for important health or symptom status outcomes were calculated. RESULTS: The sample consisted of 79 rheumatology patients, 30 men and 49 women, with a mean age of 52.6 years. The feeling of being in control was the mental health outcome rated most important by the largest number of the patients (42%); cognitive function (making decisions, solving problems) (22%), feelings of being happy (18%), and feelings of being satisfied (16%) were also rated as being "most important" by many patients. Feelings of hope were rated "most important" by the fewest patients (2%). The physicians' sensitivity to detecting patients' choices of most important outcomes was highest for social functioning and lowest for mental functioning. The specificity to detect patients' choices of less important outcomes was highest for physical functioning and lowest for symptom status. CONCLUSION: In this study involving 4 rheumatologists, patients were found to differ in their choices of important health and symptom status outcomes. Physicians often fail to identify these choices.

Adult↗
PubMed2001

Computer-assisted transurethral laser resection of the prostate (CALRP): theoretical and experimental motion plan.

Computer-Assisted transurethral laser resection of the prostate (CALRP) is a treatment modality that was designed and developed based on an integrated system of computer, robotics and laser technology in association with a minimally invasive surgery known as laser transurethral resection of the prostate (LRP). CALRP possesses complementary capabilities that could remedy many of the problems faced by surgeons in conventional LRP by delivering a treatment with repeatability and reliability. The work deals primarily in determining the feasibility study of the computer-assisted lasing motion plan (planned motion sequence controlled by a program) for LRP. A theoretical motion plan that analyzes numerically the lasing motion of the fiber was designed by calculating the profile removal rate and in vitro experiments conducted on human cadaveric prostate to verify and validate the designed motion plan. The novel motion plan, which was executed experimentally using the LaserTrode lightguide, accomplished the objective of resecting the enlarged prostate with the aid of computer and robotics technology.

Cadaver↗
PubMed2001

Experimental study of transurethral robotic laser resection of the prostate using the LaserTrode lightguide.

A longer operating time and steeper learning curve in mastering the techniques for transurethral laser resection of the prostate are the main problems faced by surgeons in addition to the existing ones in standard transurethral resection of the prostate (TURP). However, these disadvantages can be alleviated with the introduction of a treatment procedure designed and developed based on an integrated system of computer, robotics and laser technology. In vitro experiments were carried out to determine variables affecting the vaporization and coagulation lesions, in order to study the effectiveness and feasibility of robotics for this procedure. Human cadaveric prostates and fresh tauted chicken breast tissues were irradiated with different parameters using the LaserTrode lightguide in contact with the tissue. The effects of irrigant flow rate, fiber/tissue angle of inclination, number of passes, direction, speed and power of lase on the volume of tissue vaporized and coagulated, were assessed. The final phase of the experiments includes executing the robotic motion plan for the laser resection procedure on the human cadaveric prostate tissue embedded in an anatomically alike prostate phantom. It was concluded from our study that power and speed of lase are the most significant parameters influencing the volume of the vaporized and coagulated lesion. Comparison of removal rate using the new treatment procedure of robotic laser resection of the prostate with TURP and HoLRP evinced equivalent results.

Animals↗
PubMed2001

Menopause in type 1 diabetic women: is it premature?

Women with type 1 diabetes have a delayed menarche and a greater prevalence of menstrual disorders than women without diabetes. However, little is known about the menopause transition among type 1 diabetic women. The Familial Autoimmune and Diabetes (FAD) Study recruited both adult individuals who were identified from the Children's Hospital of Pittsburgh Type 1 Diabetes Registry for the years 1950-1964 and their family members. Unrelated nondiabetic control probands and their relatives were also evaluated. Women with type 1 diabetes (n = 143) compared with nondiabetic sisters (n = 186) or unrelated control subjects (n = 160) were more likely to have an older age at menarche (13.5, 12.5, and 12.6 years, respectively, P < 0.001), more menstrual irregularities before 30 years of age (45.7, 33.3, and 33.1%, respectively, P = 0.04), and a younger age at menopause (41.6, 49.9, and 48.0 years, respectively, P = 0.05). This resulted in a 6-year reduction in the number of reproductive years (30.0, 37.0, and 35.2 years, respectively, P = 0.05) for women with type 1 diabetes. Risk factors univariately associated with earlier menopause included type 1 diabetes (hazard ratio [HR] 1.99, P = 0.04), menstrual irregularities before 30 years of age (HR 1.87, P = 0.04), nulliparity (HR 2.14, P = 0.01), and unilateral oophorectomy (HR 6.51, P < 0.0001). Multivariate analysis confirmed that type 1 diabetes (HR 1.98, P = 0.056), menstrual irregularities by 30 years of age (HR 2.36, P = 0.01), and unilateral oophorectomy (HR 9.76, P < 0.0001) were independent determinants of earlier menopause in our cohort. We hypothesize that an earlier menopause, which resulted in a 17% decrease in reproductive years, is a major unstudied complication of type 1 diabetes.

Adult↗
PubMed2000

Racial differences in the utilization of oral anticoagulant therapy in heart failure: a study of elderly hospitalized patients.

To assess racial differences in the use of oral anticoagulant therapy for patients with heart failure, we conducted a cohort study of 30 hospitals in northeast Ohio. For 12,911 Medicare enrollees consecutively admitted in 1992 through 1994 with heart failure, crude and adjusted odds of being on oral anticoagulation were determined. The crude and adjusted odds of being African Americans on oral anticoagulant therapy relative to whites were 0.57 (95% confidence interval 0.47-0.69) and 0.55 (95% confidence interval 0. 45-0.67), respectively. African-Americans with heart failure were much less likely than whites to receive oral anticoagulant therapy, even after adjusting for other variables associated with anticoagulant use.

Administration, Oral↗
PubMed2000

Underutilization of oral anticoagulant therapy for stroke prevention in elderly patients with heart failure.

BACKGROUND: Oral anticoagulant therapy is the most effective prophylaxis against stroke in atrial fibrillation. Relatively few studies have examined the use of oral anticoagulant therapy for stroke prevention in a large cohort of elderly patients with heart failure. To examine the use of stroke prevention therapy, we studied elderly patients with heart failure admitted to 30 hospitals in northeast Ohio between 1992 and 1994. METHODS AND RESULTS: The sample consisted of 12,911 Medicare-insured patients > or =65 years of age who were consecutively admitted with a principal diagnosis of heart failure between 1992 and 1994. Baseline demographic and clinical characteristics for patients with the diagnosis of atrial fibrillation were calculated. Bivariate associations between receiving anticoagulant therapy and select demographic and clinical variables were calculated. In our cohort of patients with heart failure, 2093 had atrial fibrillation (16%). Only 414 (20%) of the patients with atrial fibrillation received oral anticoagulant therapy. Older age and history of gastrointestinal bleeding were significantly negatively associated with receiving oral anticoagulant therapy. History of stroke or transient ischemic attack was positively associated with receiving oral anticoagulant therapy. CONCLUSIONS: Atrial fibrillation is common in older patients with heart failure; oral anticoagulant therapy for stroke prevention, which has been shown to be effective, is underutilized in this patient population.

Administration, Oral↗
PubMed1998

Predictors of functional disability in patients with rheumatoid arthritis.

OBJECTIVE: Using the World Health Organization's classification system of the consequences of disease, this study sought to examine the impact of physical and psychological impairment variables, beyond that contributed by social, demographic, and disease variables, on the functional disability of a rheumatoid arthritis (RA) sample. Data collected during an acute episode were used to predict concurrent and future disability status. METHOD: A secondary data analysis of 85 adults hospitalized for exacerbations in arthritis was undertaken. Disability was assessed with the Health Assessment Questionnaire. Physical impairment was measured with the Keitel Function Test and Pain Analog Scales, and psychological impairment was measured with the Center for Epidemiologic Studies Depression Scale and the Perceived Self-Efficacy Scale for People with Arthritis. RESULTS: Our findings indicated that physical impairment, demographic, and disease variables accounted for 64% of the explained variance in disability during the concurrent episode. Psychological impairment as well as demographic and disease variables accounted for 49% of the explained variance in future disability status. CONCLUSION: The combined influence of demographic characteristics and the consequences of the pathology of RA experienced as physical and psychological impairments contributed differentially to disability during concurrent and future time periods.

Activities of Daily Living↗
PubMed1998

Outlining the prostate boundary using the harmonics method.

In a computerised ultrasound image guidance for automated prostatectomy system, it is necessary to identify a smooth, continuous contour for the prostate (boundary) from the ultrasound image. The radial bas-relief (RBR) method, which has been reported previously, can extract a skeletonised image from an ultrasound image automatically. After this process the prostate boundary is clearly revealed. However, analysis of the image is far from complete, as there are many spurious branches that create too much ambiguity for the system to define the actual boundary. There are also sections missing from the prostate boundary. Therefore further post-processing is required to describe and define the prostate boundary. In the paper, the harmonics method is used to describe the prostate boundary. The harmonics method uses Fourier information for noise removal and encodes a smooth boundary. The results of using the harmonics method after application of the RBR method on ultrasound images are presented. Factors that affect the performance are also highlighted and discussed.

Fourier Analysis↗
PubMed1997

Inter-rater reliability for function and strength measurements in the acute care hospital after elective hip and knee arthroplasty.

OBJECTIVE: To determine the inter-rater reliability of function and strength measurements in patients undergoing elective hip and knee arthroplasty in an acute care setting. METHOD: Forty-four patients underwent either total hip or knee arthroplasty. Patients were rated by 4 occupational therapists and 7 physical therapists on their performance of 5 functional tasks: lower extremity dressing, toilet transfer, supine-to-sit transfer, sit-to-stand transfer, and ambulation to 100 feet. Strength measurements of the quadriceps femoris muscle were measured quantitatively with a Microfet hand-held dynamometer. Data were analyzed to determine the interrater reliability using the Kappa statistic (K) for the functional tasks and the intra-class correlation coefficient (ICC) for the strength measurements. RESULTS: A high level of inter-rater reliability was achieved for lower extremity dressing, toilet transfer, supine-to-sit transfer, sit-to-stand transfer, and ambulation to 100 feet, as evidenced by K values between 0.75 and 0.99. Reliability was also excellent for quantitative strength measurements using the dynamometer, with an ICC of 0.94. CONCLUSION: This study demonstrated excellent interrater reliability with measurements of function and strength post-operatively after elective hip and knee arthroplasty. The practical implication is that by using a standardized measurement tool in the acute care setting, the treatment team can more reliably assess patients' progress, which may aid clinical decision making.

Activities of Daily Living↗
PubMed1997

Effect of growth factors on the proliferation of ligament fibroblasts from skeletally mature rabbits.

Growth factors have been shown to stimulate fibroblast proliferation during wound and ligament healing. In this study, we analyzed individual effects of eight growth factors in vitro on the proliferation of fibroblasts from the medial collateral (MCL) and anterior cruciate (ACL) ligaments of skeletally mature rabbits. We compared the proliferative response of growth factor-treated and nontreated fibroblasts of both ligaments. The growth-factor treated fibroblasts of the MCL and ACL were also compared. We found that the fibroblasts exposed to epidermal growth factor, basic fibroblast growth factor and platelet-derived growth factor-BB proliferated significantly more than untreated fibroblasts. Acidic fibroblast growth factor at a dose of 1.0 ng/ml caused significant increases in fibroblast proliferation only in the MCL. Transforming growth factor-beta 1, insulin-like growth factor-1, platelet-derived growth factor-AA, and interleukin-1 alpha did not significantly stimulate fibroblast proliferation. MCL fibroblasts generally did not proliferate significantly more than ACL fibroblasts with the exception of MCL fibroblasts exposed to the highest doses of basic fibroblast growth factor, acidic fibroblast growth factor and platelet-derived growth factor-BB. The data were also compared with those obtained earlier using fibroblasts from skeletally immature rabbits (Schmidt et al., JOR 1995). The proliferative response of both the MCL and the ACL fibroblasts was found to decrease with skeletal maturation. Thus, our findings suggest that animal age and fibroblast origin are important factors in determining the proliferative response to growth factors.

Animals↗
PubMed1996

Age, sex, and the familial risk of rheumatoid arthritis.

The familial aggregation of rheumatoid arthritis was examined to determine factors modifying the risk of rheumatoid arthritis in first degree relatives of 165 cases ascertained from January 1, 1987, through March 31, 1987, using the Saint Margaret Memorial Hospital Rheumatoid Arthritis Registry, Pittsburgh, Pennsylvania, without regard to previous information concerning the occurrence of rheumatoid arthritis among their family members. The reported affection status of first degree relatives, verified through a structured clinical evaluation, revealed a false-positive reporting rate for family members of 61%. In contrast, there were no false-negative cases detected. There were no differences in average family size or total number of years at risk between 135 simplex and 30 multiplex families; however, aggregation analysis revealed that only 18 of 30 confirmed multiplex families had significant excess risk of rheumatoid arthritis. Significant differences were found when probands from multiplex families were compared with those from simplex families with regard to female to male ratio for probands (1:1 in multiplex families vs. 3:1 in simplex families) and average age of onset for probands (41 years in multiplex families vs. 48 years in simplex families). The familial risk for rheumatoid arthritis was similar in parents (4.2%) and siblings (4.6%) and lowest for children (0.7%) of probands. The authors assert that the affection status of first degree relatives of patients with rheumatoid arthritis is often falsely reported as positive. The familiality of rheumatoid arthritis may be more accurately related to the sex and age at onset of the affected family member.

Adult↗
PubMed1996

Update on measurement of relevant outcomes in rheumatology.

It is now recognized that disease has a multidimensional impact on patients' lives. This impact can be perceived as a spectrum encompassing on one end "hard" disease outcomes such as organ failure and mortality, and on the other end "soft" outcomes such as quality of life or patient satisfaction. This spectrum may be viewed as a framework in measuring both disease impact and response to treatment. In this paper, we review improvements in the methodology of measurement of relevant outcomes and highlight new findings and emerging trends in rheumatology.

Activities of Daily Living↗
PubMed1996

Comparison of standard and alternative health assessment questionnaire scoring procedures for documenting functional outcomes in patients with rheumatoid arthritis.

OBJECTIVE: To compare statistical properties of data from the Health Assessment Questionnaire (HAQ) with those from an alternative version (AHAQ) that used a different scoring system for the item categories and disability index. Comparisons included descriptive statistics, correlations, and inferential statistics to determine whether the AHAQ would be a more sensitive measure of change in functional status. METHODS: The subjects were 107 adults diagnosed with rheumatoid arthritis and hospitalized for exacerbations in their arthritis or arthritis related joint surgery. Disability was assessed upon admission to hospital and at one year followup with the HAQ. AHAQ scores were generated for the item categories making up the disability index by taking the mean of the item scores in a category instead of the worst item score; the disability index was the mean of the alternative category scores. RESULTS: The standard method of scoring the HAQ was found to generate greater variance on category scores, lower correlations between category scores and the total disability index, and lower correlations between first and 2nd administrations of the instrument, compared to the AHAQ. HAQ disability index scores also correlated slightly lower than those of AHAQ to scores from the HAQ pain scales, and to scores from 2 other measures of functional disability. In addition, the AHAQ was found to be more powerful in detecting functional changes at one year followup. CONCLUSION: Because of its statistical properties the AHAQ scoring method may be preferable to the HAQ method when the instrument is used for documenting change in functional outcomes.

Aged↗
PubMed1995

Effects of cyclophosphamide on the development of malignancy and on long-term survival of patients with rheumatoid arthritis. A 20-year followup study.

OBJECTIVE: To examine the effects of cyclophosphamide (CYC) on the development of malignancies and on the long-term survival of patients with rheumatoid arthritis (RA). METHODS: We used a longitudinal cohort design in which 119 patients (76 women and 43 men) with refractory RA who were treated with oral CYC between 1968 and 1973 were compared with 119 control patients with RA (matched for age, sex, disease duration, and functional class) who were evaluated during the same time period but did not receive CYC. RESULTS: There was increased risk of malignancy in the CYC-treated group, with 50 cancers found in 37 patients in the CYC group compared with 26 cancers in 25 of the control patients (P < 0.05). The relative risk of cancer for those treated with CYC was 1.5 (95% confidence interval 0.93-5.5). Nine of the malignancies in the CYC group were bladder cancers and 19 were skin cancers, compared with no bladder cancers and 6 skin cancers in the control group. The total dose of CYC was higher in those who developed cancer, particularly in those with bladder cancer. Three of the bladder cancers occurred 14, 16, and 17 years after CYC had been discontinued. CONCLUSION: The risk of malignancy, particularly bladder cancer, in RA patients treated with oral CYC continues even 17 years after discontinuation of the drug.

Age Factors↗
PubMed1995

Incidence of systemic lupus erythematosus. Race and gender differences.

OBJECTIVE: To examine racial differences in the incidence of systemic lupus erythematosus (SLE). METHODS: A population-based registry of SLE patients in Allegheny County, Pennsylvania, was used to identify incident cases of SLE diagnosed between January 1, 1985 and December 31, 1990, from 3 sources, by medical record review (University of Pittsburgh Lupus Databank, rheumatologists, and hospitals). Capture-recapture methods using log-linear models were used to estimate the level of case-finding and to calculate 95% confidence intervals (CI). Incidence rates were calculated per 100,000 population. RESULTS: A total of 191 definite and 78 probable incident cases of SLE were identified, and the overall annual incidence rates were 2.4 (95% CI 2.1-2.8) and 1.0 (95% CI 0.8-1.3), respectively. The crude incidence rates of definite SLE were 0.4 for white males, 3.5 for white females, 0.7 for African-American males, and 9.2 for African-American females. The annual incidence rates of definite SLE remained fairly constant over the study interval. African-American females with definite SLE had a younger mean age at diagnosis compared with white females (P < 0.05). Since the overall ascertainment rate was high (85%; 95% CI 78-92%), the ascertainment-corrected incidence rate for definite SLE, 2.8 (95% CI 2.6-3.2), was similar to the crude rate. CONCLUSION: Our rates clearly confirm previous reports of an excess incidence of SLE among females compared with males and among African-Americans compared with whites. We have used capture-recapture methods to improve the accuracy of SLE incidence rates, and we advocate their use to facilitate comparisons across studies.

Adolescent↗
PubMed1995

Effect of growth factors on the proliferation of fibroblasts from the medial collateral and anterior cruciate ligaments.

Growth factors have been shown to stimulate fibroblast division and thus may influence ligament healing. We analyzed the effects of individual growth factors on the proliferation of fibroblasts from the medial collateral and anterior cruciate ligaments of the rabbit in vitro in order to identify growth factors that might enhance proliferation of fibroblasts and to compare the responses of the fibroblasts from the two ligaments to these growth factors. Through measurement of the uptake of [3H]-thymidine into DNA, fibroblasts from these ligaments that had been treated with epidermal growth factor and basic fibroblast growth factor were found to proliferate nearly eight times more than control fibroblasts. Additionally, the fibroblasts of both ligaments proliferated at similar rates when exposed to platelet-derived growth factor-AA, platelet-derived growth factor-BB, basic fibroblast growth factor, insulin-like growth factor-1, and interleukin-1-alpha. However, epidermal growth factor and transforming growth factor-beta caused the fibroblasts from the medial collateral ligament to proliferate at a rate 1.3-1.4 times greater than that of fibroblasts from the anterior cruciate ligament. The reverse was true with acidic fibroblast growth factor, which stimulated the fibroblasts from the anterior cruciate ligament to proliferate at a rate 1.3-1.6 times greater than that of fibroblasts from the medial collateral ligament. This study demonstrated that growth factors can stimulate cell division in ligaments and may be effective in enhancing ligament healing but that these differences were not great enough to explain fully the clinical differences observed between healing of the medial collateral and anterior cruciate ligaments.

Animals↗