Biomedical subjects

Chih-Hung Chang

Publications and source records attributed to Chih-Hung Chang.

At least 19 recordsLinked to original sources

PubMed2006

The SF-36 physical and mental health factors were confirmed in cancer and HIV/AIDS patients.

BACKGROUND AND OBJECTIVE: This study assesses the extent to which the RAND-36/SF-36 items measure physical and mental health (PH and MH), as implied by existing summary scoring systems. METHODS: A total of 1,714 heterogeneous cancer and HIV/AIDS patients were recruited from five institutions. Of these, 56% were women; 81% Caucasians; and about 10% were from each of the major cancer types and HIV/AIDS. RESULTS: Analyses of the SF-36 confirmed the two dimensions of health namely physical and mental. However, item fit statistics and residual factor analysis revealed that some items intended to represent the PH dimension fit better with the MH dimension. CONCLUSION: This paper demonstrated the value of Rasch residual factor analysis for understanding and enhancing interpretation of health.

Activities of Daily Living↗

PubMed2006

Development and validation of a preference weight multiattribute health outcome measure for rheumatoid arthritis.

OBJECTIVE: To develop and validate multiattribute measures for patients with rheumatoid arthritis (RA) to report health states and estimate preference weights. METHODS: Survey materials were mailed to 748 patients. Factor analysis, an item response theory-based model, and an internal consistency test were used to identify attributes and evaluate items. Two multiattribute preference weight functions (MAPWF) were constructed. Construct validity of the new measures was then tested. RESULTS: Four hundred eighty-seven patients returned the survey; 24 items on 6 health attributes were selected to form the new outcomes measure. Two MAPWF were derived with preference weights measured with time tradeoff and visual analog scales as dependent variables. All validity test results were statistically significant. CONCLUSION: Our results reveal that the new measures are reliable and valid in assessing health states and associated preference weights of patients with RA.

Activities of Daily Living↗

PubMed2006

A portable potentiostat for the bilirubin-specific sensor prepared from molecular imprinting.

A portable amperometric potentiostat was designed and implemented in this work. It was developed to acquisit the current signals produced from bilirubin by an electrochemical sensor. Based on an SOC-based chip, this potentiostat has the merits of moderate accuracy, small size, low cost, and high portability. The bilirubin electrode was prepared by synthesizing a thin layer of bilirubin imprinted poly(methacrylic acid-co-ethylene glycol dimethacrylate) onto the Au layer. With the molecularly imprinted polymer (MIP) film, specific detection of bilirubin was successfully achieved. The cyclic voltammogram of the electrode was measured from this assembled potentiostat. The performance from a commercial potentiostat was considered rather stable and was used as a reference to examine and evaluate the performance of the assembled potentiostat. The detected current signals by the bilirubin sensing were obtained. Linear calibration with a sensitivity of 1.344+/-0.38 microA/mg dl was achieved. Our experimental results showed that the proposed potentiostat's performance could achieve sufficient performance. The evaluation was also made from the aspects such as reset time and steady-response time. The self-assembled potentiostat thus demonstrated its ability in precise detection of bilirubin from an electrode layered with the imprinted polymer film.

Bilirubin↗

PubMed2006

The effects of glove thickness and work load on female hand performance and fatigue during a infrequent high-intensity gripping task.

In various workplaces, gloves are commonly employed to protect the hands with the design rationale of 'the thicker the gloves, the better the protection'. Therefore, the present paper investigated the effects of glove thickness on hand performance and fatigue during two infrequent high-intensity gripping tasks, such as 5-s and sustained tasks. The hand performance was evaluated by maximum volitional contraction (MVC) and its associated time needed to reach the MVC (TMVC), and the total force generation (TFG) during the sustained task. The hand fatigue was assessed by MVC degeneration (DeltaMVC), the shift in time needed to reach the MVC (DeltaTMVC), and the maximal endurance time (MET) associated with the sustained task. Ten female subjects took part in the experiment voluntarily. The four-gloved conditions included bare hand, wearing one layer (Cotton-1), wearing two layers of cotton gloves (Cotton-2), and covering the handle with two layers of cotton glove and exerting with the bare hand (Covered-2). The results indicates that wearing gloves decreased the grip MVC, and the thicker the gloves, the less the grip MVC, but the wearing style did not change the MVC (Cotton-2 MVC was indifferent from Covered-2 MVC). As to muscular fatigue, on the other hand, wearing gloves did not affect DeltaMVC, MET, TMVC, or DeltaTMVC. Due to the greater bare-hand MVC and indifferent MET, bare-hand TFG was better than those conditions with gloves. Finally, the load specified here did not alter TMVC or DeltaTMVC, but the greater the load, the more strength degeneration (DeltaMVC) was induced.

Adult↗

PubMed2006

Knowledge about breast cancer and participation in a faith-based breast cancer program and other predictors of mammography screening among African American women and Latinas.

This article assessed the impact of knowledge of breast cancer and type and intensity of participation in a church-based breast cancer education program and other factors on mammography screening among African Americans and Latinas. Logistic regression was used to assess the impact of these factors on self-reported mammography utilization. Passive participation in church-sponsored activities, measured by breast cancer information that was heard, seen, or read, was found to be significantly associated with the likelihood of mammography use among African Americans. Moreover, African Americans who reported hearing, seeing, or reading about mammograms at their churches four or more times were 15 times more likely to report mammography use within the past year than were those who encountered information only once. Messages from pastors and church bulletin announcements were the most significant predictors. An increase in knowledge was not associated with higher mammography use. For Latinas, none of the hypothesized knowledge or participation variables was found to be significant. The results suggest that faith-based breast cancer programs can be effective by adopting tailored strategies to raise awareness about the importance of early detection.

Adult↗

PubMed2006

Validation of a patient satisfaction questionnaire for anemia treatment, the PSQ-An.

BACKGROUND: Treating anemia associated with chemotherapy and many cancers is often necessary. However, patient satisfaction with anemia treatment is limited by the lack of validated instruments. We developed and validated a new treatment-specific patient satisfaction instrument: the Patient Satisfaction Questionnaire for Anemia Treatment (PSQ-An). Treatment burden and overall satisfaction scales were designed for ease of use in clinical practice. METHODS: 312 cancer patients (141 breast, 69 gynecological, and 102 non-small cell lung) were targeted to complete the PSQ-An at 4 week intervals. Data from weeks 5 and 9 were analyzed. Patients also completed the MOS SF-36 Global Health assessment and questions concerning resources devoted to anemia treatment. Item reduction used endorsement rates, floor/ceiling effects, and item-item correlations. Factor analysis identified meaningful subscales. Test-retest reliability was assessed. Construct validity was tested, using Pearson's correlations, by comparing subscale scores to Global Health, hemoglobin levels, and resources devoted to anemia treatment. RESULTS: The overall response rate was 92.9% (264/284) at week 5. Most (84.2%) of the patients were female, and the mean (SD) age was 60.2 (+/- 11.8) years. Two distinct subscales were identified measuring treatment burden (7 items) and overall satisfaction (2 items). Test-retest reliability was examined (ICC: 0.45-0.67); both were internally consistent (alpha = 0.83). Both subscales exhibited convergent and divergent validity with independent measures of health. ANOVA results indicated that the PSQ-An Satisfaction subscale discriminated between 5 levels of MOS SF-36 Global Health (P = 0.006). CONCLUSION: The PSQ-An is a validated, treatment-specific instrument for measuring satisfaction with anemia treatment for cancer patients. PSQ-An subscales reflect the burden of injection anemia treatment on cancer patients and their assessment of the overall treatment value.

Aged↗

PubMed2006

The WOMQOL instrument measured quality of life in women of reproductive age with no known pathology.

BACKGROUND AND OBJECTIVES: The Women's Quality of Life Questionnaire (WOMQOL) was developed to measure aspects of the health of women of reproductive age with no known pathology. METHODS: Five experts in women's health and mental health rated a pool of 140 items as very significant, somewhat significant, or insignificant to women's health. Sixty-seven items were retained and formatted as a self-reported questionnaire with dichotomous responses to each statement ("true" and "false"). A total of 1,207 women completed the instrument during the follicular and late luteal phases of their menstrual cycles. Dichotomous response data from the follicular phases were analyzed using item response theory-based full-information item factor analysis to identify interpretable factors. Measurement invariance of the obtained factors across cycle phases and age cohorts was further evaluated using differential item functioning (DIF). RESULTS: Four primary factors, made up of the 10 items with highest factor loading in each factor, were found to measure physical, mental, social, and spiritual health. No items were found to display DIF across the phases of menstrual cycles or age cohorts. CONCLUSION: Although additional studies of diverse groups of women are advised, the final 40-item WOMQOL is a psychometrically sound measure that can be used to evaluate the quality of life of women of reproductive age in the general population.

Activities of Daily Living↗

PubMed2006

TGF-beta1 immobilized tri-co-polymer for articular cartilage tissue engineering.

Tri-co-polymer with composition of gelatin, hyaluronic acid and chondroitin-6-sulfate has been used to mimic the cartilage extracellular matrix as scaffold for cartilage tissue engineering. In this study, we try to immobilize TGF-beta1 onto the surface of the tri-co-polymer sponge to suppress the undesired differentiation during the cartilage growth in vitro. The scaffold was synthesized with a pore size in a range of 300-500 microm. TGF-beta1 was immobilized on the surface of the tri-co-polymer scaffold with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) as a crosslinking agent. Tri-co-polymer scaffolds with and without TGF-beta1 were seeded with porcine chondrocytes and cultured in a spinner flask for 2, 4, and 6 weeks. The chondrocytes were characterized by the methods of immunohistochemical staining with anti-type II collagen and anti-S-100 protein monoclonal antibody, and RT-PCR. After culturing for 4 weeks, chondrocytes showed positive in S-100 protein, Alcian blue, and type II collagen for the scaffold with TGF-beta1 immobilization. There is no observed type I and type X collagen expression in the scaffolds from the observation of RT-PCR. In addition, the scaffold without TGF-beta1 immobilization, type X collagen, can be detected after cultured for 2 weeks. Type I collagen was progressively expressed after 4 weeks. These results can conclude that TGF-beta1 immobilized scaffold can suppress chondrocytes toward prehypertrophic chondrocytes and osteolineage cells. The tri-co-polymer sponge with TGF-beta1 immobilization should have a great potential in cartilage tissue engineering in the future.

Animals↗

PubMed2005

Tissue engineering-based cartilage repair with allogenous chondrocytes and gelatin-chondroitin-hyaluronan tri-copolymer scaffold: a porcine model assessed at 18, 24, and 36 weeks.

We previously showed that cartilage tissue can be engineered in vitro with porcine chondrocytes and gelatin/chondoitin-6-sulfate/hyaluronan tri-copolymer which mimic natural cartilage matrix for use as a scaffold. In this animal study, 15 miniature pigs were used in a randomized control study to compare tissue engineering with allogenous chondrocytes, autogenous osteochondral (OC) transplantation, and spontaneous repair for OC articular defects. In another study, 6 pigs were used as external controls in which full thickness (FT) and OC defects were either allowed to heal spontaneously or were filled with scaffold alone. After exclusion of cases with infection and secondary arthritis, the best results were obtained with autogenous OC transplantation, except that integration into host cartilage was poor. The results for the tissue engineering-treated group were satisfactory, the repair tissue being hyaline cartilage and/or fibrocartilage. Spontaneous healing and filling with scaffold alone did not result in good repair. With OC defects, the subchondral bone plate was not restored by cartilage tissue engineering. These results show that tri-copolymer can be used in in vivo cartilage tissue engineering for the treatment of FT articular defects.

Animals↗

PubMed2005

NPC-14686 (Fmoc-l-homophenylalanine)-induced CaCa2+ increases and death in human prostate cancer cells.

The effect of NPC-14686, a potential anti-inflammatory drug, on cytosolic free Ca2+ levels ([Ca2+]i) and growth in PC3 human prostate cancer cells was examined by using fura-2 as a fluorescent Ca2+ indicator and WST-1 as a fluorescent growth dye. NPC-14686 at concentrations above 10 microM increased [Ca2+]i in a concentration-dependent manner with an EC50 value of 100 microM. NPC-14686-induced Ca2+ influx was confirmed by Mn2+ quench of fura-2 fluorescence. The Ca2+ signal was also reduced by removing extracellular Ca2+. Pretreatment with 1 microM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor) to deplete the endoplasmic reticulum Ca2+ nearly abolished 200 microM NPC-14686-induced Ca2+ release; and conversely pretreatment with NPC-14686 completely inhibited thapsigargin-induced Ca2+ release. The Ca2+ release induced by 200 microM NPC-14686 was not affected by inhibiting phospholipase C with 2 microM U73122. Overnight treatment with 1-500 microM NPC-14686 decreased cell viability in a concentration-dependent manner. These findings suggest that in human PC3 prostate cancer cells, NPC-14686 increases [Ca2+]i by evoking extracellular Ca2+ influx and releasing intracellular Ca2+ from the endoplasmic reticulum via a phospholiase C-independent manner. NPC-14686 may be cytotoxic to prostate cancer cells.

Aminobutyrates↗

PubMed2005

Independent [Ca2+]i increases and cell proliferation induced by the carcinogen safrole in human oral cancer cells.

The effect of the carcinogen safrole on intracellular Ca2+ movement and cell proliferation has not been explored previously. The present study examined whether safrole could alter Ca2+ handling and growth in human oral cancer OC2 cells. Cytosolic free Ca2+ levels ([Ca2+]i) in populations of cells were measured using fura-2 as a fluorescent Ca2+ probe. Safrole at a concentration of 325 microM started to increase [Ca2+]i in a concentration-dependent manner. The Ca2+ signal was reduced by 40% by removing extracellular Ca2+, and was decreased by 39% by nifedipine but not by verapamil or diltiazem. In Ca2+-free medium, after pretreatment with 650 microM safrole, 1 microM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor) barely induced a [Ca2+]i rise; in contrast, addition of safrole after thapsigargin treatment induced a small [Ca2+]i rise. Neither inhibition of phospholipase C with 2 microM U73122 nor modulation of protein kinase C activity affected safrole-induced Ca2+ release. Overnight incubation with 1 microM safrole did not alter cell proliferation, but incubation with 10-1000 microM safrole increased cell proliferation by 60+/-10%. This increase was not reversed by pre-chelating Ca2+ with 10 microM of the Ca2+ chelator BAPTA. Collectively, the data suggest that in human oral cancer cells, safrole induced a [Ca2+]i rise by causing release of stored Ca2+ from the endoplasmic reticulum in a phospholipase C- and protein kinase C-independent fashion and by inducing Ca2+ influx via nifedipine-sensitive Ca2+ entry. Furthermore, safrole can enhance cell growth in a Ca2+-independent manner.

Calcium↗

PubMed2005

Nonylphenol-induced Ca2+ elevation and Ca2+-independent cell death in human osteosarcoma cells.

The effect of the environmental toxicant nonylphenol on cytosolic free Ca2+ concentration ([Ca2+]i) and proliferation has not been explored in human osteoblast-like cells. This study examined whether nonylphenol alters Ca2+ levels and causes cell death in MG63 human osteosarcoma cells. [Ca2+]i and cell death were measured using the fluorescent dyes fura-2 and WST-1 respectively. Nonylphenol at concentrations above 3 microM increased [Ca2+]i in a concentration-dependent manner. The Ca2+ signal was reduced by 90% by removing extracellular Ca2+. The nonylphenol-induced Ca2+ influx was insensitive to blockade of L-type Ca2+ channel blockers. After pretreatment with 10 microM nonylphenol, 1 microM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor) failed to induce [Ca2+]i rises. Inhibition of phospholipase C with 2 microM U73122 did not change nonylphenol-induced [Ca2+]i rises. The nonylphenol-induced [Ca2+]i rises were enhanced or inhibited by phorbol myristate acetate or GF 109203X, respectively. At concentrations of 10 and 20 microM nonylphenol killed 55% and 100% cells, respectively. The cytotoxic effect of 10 microM nonylphenol was unaltered by pre-chelating cytosolic Ca2+ with BAPTA. Collectively, in MG63 cells, nonylphenol induced [Ca2+]i rises by causing Ca2+ release from intracellular stores and Ca2+ influx from extracellular space. Furthermore, nonylphenol can cause Ca2+-unrelated cytotoxicity in a concentration-dependent manner.

Calcium↗

PubMed2005

Assessment instruments.

Assessment is the undergirding of palliative care and of geriatrics care. Both disciplines insist on a comprehensive assessment that includes personal and social aspects of the patient's illness experience. At the same time, both face challenges due to the amount of time and skill needed to encompass such a broad scope and the often heavy illness burden of the patients, which makes interaction stressful or difficult. This article examines question-based assessment instruments in palliative care for elders. Important in all aspects of medicine, reliance on verbal assessments is of special importance in palliative care.

Aged↗

PubMed2005

Visual analog scales for assessing surgical pain.

BACKGROUND: Four visual analog scales were constructed to assess sensory and affective components of operative pain. The Surgical Pain Scales (SPS) measure pain while at rest, pain during normal activities, pain during work or exercise, and pain unpleasantness. STUDY DESIGN: Longitudinal data from 2,164 patients in a randomized trial of laparoscopic versus open hernia repair established the reliability, validity, and sensitivity to change of the SPS. Correlations and t-tests were used to determine their psychometric properties compared with the SF-36 health status instrument. RESULTS: Intraclass correlation coefficients of 0.95 for the sensory scales and 0.94 for the unpleasantness rating confirmed that the SPS produced reliable measurements. Correlations ranging from 0.44 to 0.60 between the visual analog scales and the bodily pain dimension on the SF-36 and significant differences between SPS levels for patients requiring more and less time to resume normal activities (p< or =0.015 to p< or =0.002) supported the validity of the scales. Clinical responsiveness was demonstrated by a 33.5-mm reduction (standard error = 1.4 mm) in the mean rating on a 150-mm scale measuring pain during normal activities for patients reporting postoperative improvement on the bodily pain dimension (p< or =0.0001). CONCLUSIONS: The Surgical Pain Scales demonstrated excellent psychometric properties in this study population. The SPS can be used to compare pain levels between groups at a single point in time or to track change for individual patients over time or after operations. Individualized pain management interventions can be tailored based on the sensory and effective ratings.

Activities of Daily Living↗

PubMed2005

Assessment of patient functional status after surgery.

BACKGROUND: Improvement in day-to-day functioning is a valued outcome of surgical intervention. A new functional status assessment instrument, the Activities Assessment Scale (AAS), was designed for a randomized clinical trial evaluating laparoscopic versus open hernia repair procedures. STUDY DESIGN: The study data set included 2,164 patients at baseline and 1,562 patients at 3-month followup. Only male patients were enrolled in the trial. The psychometric characteristics of the AAS were examined in statistical analyses of cross-sectional and longitudinal data from the trial. Correlational analyses, factor analyses, and t-tests were used to evaluate scale performance. RESULTS: We found that the AAS was a reliable measure (Cronbach's Coefficient Alpha =0.85) in the patient population studied. Factor analyses identified three subscales (sedentary activities; ambulatory activities; work and exercise activities). Construct validity was demonstrated by a correlation of 0.65 between the AAS and the physical functioning (PF) dimension of the SF-36 (p < 0.001); comparisons between clinical subgroups further confirmed its validity (p < 0.001). Patients reporting improvement on the physical functioning dimension after surgery showed an effect size of 1.20 for preoperative-postoperative change in their AAS scores. CONCLUSIONS: The AAS has been demonstrated to be a reliable, valid, and clinically responsive instrument that can be used to evaluate patient functioning after hernia surgery. It is easy to administer and requires less than 5 minutes of patient time to complete. This measurement system may prove useful in assessing surgical outcomes in both research and office practice settings.

Activities of Daily Living↗

PubMed2005

Development and validation of the Communication and Attitudinal Self-Efficacy scale for cancer (CASE-cancer).

We sought to develop a reliable and valid measure of patient self-efficacy within the context of productive communication and positive attitude for cancer patients. A set of 19 potential items for the Communication and Attitudinal Self-Efficacy scale for cancer (CASE-cancer) was pilot tested with 50 cancer patients. Based on the pilot test, item valence was made consistent (i.e., all items worded positively) and the response scale was simplified. The CASE-cancer was then administered to 127 persons receiving cancer treatment at general oncology clinics in Shreveport, Louisiana and Chicago, Illinois. Psychometric analyses revealed three 4-item factors: understanding and participating in care, maintaining a positive attitude, and seeking and obtaining information. The CASE-cancer proved to have high internal consistency and construct validity. Moreover, scale items performed similarly across literacy levels. The CASE-cancer is a psychometrically-sound tool that may provide new information on important mediating factors of cancer care. Our two-step approach to presenting response options may also provide a model for helping lower literate patients more accurately respond to survey items.

Adaptation, Psychological↗

PubMed2005

Thimerosal-induced cytosolic Ca2+ elevation and subsequent cell death in human osteosarcoma cells.

The effect of the oxidizing agent thimerosal on cytosolic free Ca(2+) concentration ([Ca(2+)]i) and proliferation has not been explored in human osteoblast-like cells. This study examined whether thimerosal alters Ca(2+) levels and causes cell death in MG63 human osteosarcoma cells. [Ca(2+)]i and cell death were measured using the fluorescent dyes fura-2 and WST-1, respectively. Thimerosal at concentrations above 5 microM increased [Ca(2+)]i in a concentration-dependent manner. The Ca(2+) signal was reduced by 80% by removing extracellular Ca(2+). The thimerosal-induced Ca(2+) influx was sensitive to blockade of La(3+), and dithiothreitol (50 microM) but was insensitive to nickel and several L-type Ca(2+) channel blockers. After pretreatment with 1 microM thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor), thimerosal failed to induce [Ca(2+)]i rises. Inhibition of phospholipase C with 2 microM U73122 did not change thimerosal-induced [Ca(2+)]i rises. At concentrations of 5, 10 and 20 microM thimerosal killed 33, 55 and 100% cells, respectively. The cytotoxic effect of 5 microM thimerosal was reversed by 54% by prechelating cytosolic Ca(2+) with BAPTA. Collectively, in MG63 cells, thimerosal induced a [Ca(2+)]i rise by causing Ca(2+) release from endoplasmic reticulum stores and Ca(2+) influx from extracellular space. Furthermore, thimerosal can cause Ca(2+)-related cytotoxicity in a concentration-dependent manner.

Bone Neoplasms↗

PubMed2005

A comparison of three methods of measuring dementia-specific quality of life: perspectives of residents, staff, and observers.

PURPOSE: This exploratory study compared three methods of assessing dementia specific quality of life, corresponding to the perspectives of residents, staff members, and trained observers. DESIGN AND METHODS: We collected data on 172 residents with dementia in four special care nursing facilities and three assisted living facilities. Analyses assessed the relationship of each quality-of-life method or perspective to the others and to resident characteristics such as cognitive and functional status. RESULTS: The relationship of staff quality-of-life measures to resident characteristics varied by care setting while no significant relationships were found for resident quality-of-life measures. Staff and observational measures were moderately correlated in both settings. Moderate correlations of resident measures with staff and observational measures were found in the assisted living sample. IMPLICATIONS: Each perspective is relatively independent and somewhat unique. Measures that focus on specific aspects of quality of life may be more appropriate to use with assisted living residents than with residents of special care facilities.

Aged, 80 and over↗