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Biomedical subjects

M C Wang

Publications and source records attributed to M C Wang.

At least 55 records · Page 3Linked to original sources
PubMed1999

Efficacy of relapse prevention: a meta-analytic review.

Although relapse prevention (RP) has become a widely adopted cognitive-behavioral treatment intervention for alcohol, smoking, and other substance use, outcome studies have yielded an inconsistent picture of the efficacy of this approach or conditions for maximal effectiveness. A meta-analysis was performed to evaluate the overall effectiveness of RP and the extent to which certain variables may relate to treatment outcome. Twenty-six published and unpublished studies with 70 hypothesis tests representing a sample of 9,504 participants were included in the analysis. Results indicated that RP was generally effective, particularly for alcohol problems. Additionally, outcome was moderated by several variables. Specifically, RP was most effective when applied to alcohol or polysubstance use disorders, combined with the adjunctive use of medication, and when evaluated immediately following treatment using uncontrolled pre-post tests.

Alcoholism↗
PubMed1999

Double cancers of the kidney and ureter complicated with emphysematous pyelonephritis within the parenchyma of the renal tumour.

Emphysematous pyelonephritis and double cancers of the kidney and urinary tract are rare. We describe here a case of a diabetic man who had simultaneous renal cell carcinoma of the right kidney and transitional cell carcinoma of the right ureter complicated with emphysematous pyelonephritis within the tumour parenchyma of renal cell carcinoma. Imaging and pathology are demonstrated.

Aged↗
PubMed1999

Cranial bone fixation in infants and children.

A technique is described for fixing cranial bone flaps with absorbable sutures and bone shims. This technique is a cost-efficient method of rapidly achieving rigid structural stability with excellent cosmetic results. The kerf created by the craniotome is bridged at multiple sites by bone chips harvested from the inner edge of the bone flap. Solid bony union is documented on histopathological analysis. The technique requires no special tools and avoids the problems associated with the use of plates, screws and wire.

Adolescent↗
PubMed1999

Bone mineral acquisition in healthy Asian, Hispanic, black, and Caucasian youth: a longitudinal study.

Ethnic and gender differences in bone mineral acquisition were examined in a longitudinal study of 423 healthy Asian, black, Hispanic, and white males and females (aged 9-25 yr). Bone mass of the spine, femoral neck, total hip, and whole body was measured annually for up to 4 yr by dual energy x-ray absorptiometry. Age-adjusted mean bone mineral curves for areal (BMD) and volumetric (BMAD) bone mineral density were compared for the 4 ethnic groups. Consistent differences in areal and volumetric bone density were observed only between black and nonblack subjects. Among females, blacks had greater mean levels of BMD and BMAD at all skeletal sites. Differences among Asians, Hispanics, and white females were significant for femoral neck BMD, whole body BMD, and whole body bone mineral content/height ratio, for which Asians had significantly lower values; femoral neck BMAD in Asian and white females was lower than that in Hispanics. Like the females, black males had consistently greater mean values than nonblacks for all BMD and BMAD measurements. A few differences were also observed among nonblack male subjects. Whites had greater mean total hip BMD, whole body BMD, and whole body bone mineral content/height ratio than Asian and Hispanic males; Hispanics had lower spine BMD than white and Asian males. The tempo of gains in BMD varied by gender and skeletal site. In females, total hip, spine, and whole body BMD reached a plateau at 14.1, 15.7, and 16.4 yr, respectively. For males, gains in BMD leveled off at 15.7 yr for total hip and at age 17.6 yr for spine and whole body. Black and Asian females and Asian males tended to reach a plateau in BMD earlier than the other ethnic groups. The use of gender- and ethnic-specific standards is recommended when interpreting pediatric bone densitometry data.

Absorptiometry, Photon↗
PubMed1999

Preference for thinness in Singapore--a newly industrialised society.

BACKGROUND/AIMS: A cultural preference for thinness has been implicated in the development of eating disorders in Western, post-industrialised societies. In transitional societies like Singapore, a shift in expectations of ideal body size (toward thinness) may lead to an increase in eating disorders. This study investigated perceptions about body size and shape in over 200 youths living in Singapore, and the influences of adiposity, gender, Westernization and parents' education. METHODS: A self-administered questionnaire was used to gather social and cultural information from 137 males and 143 females, aged 17-22 years. It included questions relating to eating behaviour and body satisfaction from which a "preference for thinness score" was derived. Westernization was indicated by language spoken at home. Adiposity was measured by triceps skinfold and body mass index. Multiple linear regression analysis was used to assess the associations of adiposity, mother's education, father's education, and language spoken at home with the preference for thinness score. RESULTS: Dissatisfaction with body size and shape increased with tertile of adiposity among females, and thoughts about dieting and becoming thinner were present even among underweight girls. Unlike the females, the highest proportion of males satisfied with their body size and shape, was associated with the middle tertile of BMI. Speaking English at home, but not parents' education, was positively associated with body dissatisfaction after controlling for BMI. CONCLUSION: Chinese Singaporean female youths have a preference for thinness as an ideal body size. The epidemiology of eating disorders in Singapore and other newly industrialised societies warrants further investigation.

Adolescent↗
PubMed1998

Bone acquisition and loss in children and adults with cystic fibrosis: a longitudinal study.

OBJECTIVES: To determine patterns of bone mineral acquisition in children and young adults with cystic fibrosis (CF) and to identify clinical and laboratory correlates of change in bone mineral density (BMD). STUDY DESIGN: Bone mineral and clinical status were assessed in 41 patients with CF (26 female, aged 9 to 50 years) at baseline and 1.5 years later. Bone mineral content of the lumber spine, femoral neck, and whole body was determined by dual-energy x-ray absorptiometry and expressed as BMD and bone mineral apparent density (BMAD). Changes in weight, height, pubertal status, glucocorticoid use, physical activity, disease severity, and biochemical markers of bone turnover were examined for associations with changes BMD and BMAD. RESULTS: Mean BMD Z-scores (adjusted for age and sex) were reduced at the spine, hip, and whole body at baseline in both adults and youths, and decreased further at all sites among youths at follow-up (-0.4 at spine, p < 0.05; -0.3 at hip, p < 0.10; -0.5 for whole body, p < 0.0005). These data indicate failure to gain bone mineral at the expected rate. BMAD was also reduced at follow-up, suggesting that the observed osteopenia could not be explained by small bone size. Bone loss at multiple sites was observed in four youths and two adults. In general glucocorticoid use, change in body mass, physical activity, and disease severity were the most significant correlates for change in BMD and in BMD Z-score. CONCLUSIONS: Osteopenia in CF generally reflects inadequate gains in bone mineral, although bone loss may occur, particularly in patients requiring glucoc therapy. Late gains in bone mineral may accompany weight gain and pubertal development, but the catch-up appears to be incomplete.

Adolescent↗
PubMed1998

Position of poly(methyl methacrylate) and silicone intraocular lenses after phacoemulsification.

PURPOSE: To compare the positional change of poly(methyl methacrylate) (PMMA) and silicone intraocular lenses (IOLs) in vivo after phacoemulsification. SETTING: Taipei Municipal Yang-Ming Hospital, Taipei, Taiwan. METHODS: A prospective study of 70 cataractous eyes treated by phacoemulsification with IOL implantation was carried out. The eyes were randomized into 2 groups based on IOL type: 1-piece PMMA IOL; 3-piece silicone IOL. The amount of IOL tilt and decentration was measured and anterior chamber depth (ACD) determined by Scheimpflug photography using an anterior eye segment analysis system (EAS-1000, Nidek). All eyes were examined 1 week and 1 to 6 months after surgery. RESULTS: No statistically significantly differences were found in the amount of tilt and decentration between 2 IOL types throughout the study. The ACDs were relatively constant in both groups through the early postoperative periods. CONCLUSION: The stability of PMMA and silicone IOLs were the same after phacoemulsification.

Aged↗
PubMed1998

Evidence for the participation of the proteasome and calpain in early phases of muscle cell differentiation.

Objectives were to investigate the role of the proteasome and m-calpain to muscle cell differentiation. Accordingly, we investigated the effects of lactacystin, a proteasome inhibitor, and calpain inhibitor-II (CI-II) on L8 muscle cell differentiation and assessed concentrations of proteasomal and calpain subunit mRNAs during differentiation. L8 myoblasts were induced to differentiate by culturing in mitogen-depleted medium. To assess the importance of the proteasome and calpain to differentiation, we examined effects of lactacystin and CI-II on creatine kinase (CK) activity. In the absence of inhibitor, CK activity was detectable within 48 h of mitogen depletion and myotubes were formed. Addition of lactacystin or CI-II to cultures drastically reduced CK activity and prevented formation of myotubes. Hence, proteasome and calpain are both necessary for differentiation. In order to identify which proteasomal subunits were regulated during differentiation, we examined the concentrations of two 20S core subunits (C8 and C9) and three 22S ATPases (MSS1, S4 and TBP1) during differentiation. Concentrations of m-calpain and beta-tubulin mRNAs were also assessed. Differentiation was associated with slight increases (ca. 30%) in concentrations of mRNAs encoding the proteasomal 20S core subunits (C8 and C9) and with large increases (approximately 2-fold) in mRNAs encoding the regulatory subunit ATPases. m-calpain mRNA concentration also increased two-fold following mitogen depletion. beta-Tubulin mRNA concentration remained unchanged early in the differentiation process and thereafter declined. Of interest, changes in proteasomal and m-calpain mRNAs occurred within 6-24 h of mitogen depletion (i.e., at least 24-36 h prior to detectable changes in creatine kinase activity). These results indicate that changes in expression of proteasome and calpains subunits occur early in the differentiation process. These changes may be required for the normal course of differentiation to proceed. Differentiation is associated with larger changes in proteasomal ATPase mRNAs than in 20S core particle mRNAs indicating that either turnover rates of the 22S ATPase subunits are more rapid in differentiating cells than of the 20S core particles or that functions of the regulatory subunits become more important during muscle cell differentiation.

Acetylcysteine↗
PubMed1998

Is captopril-induced improvement of insulin sensitivity mediated via endothelin?

Angiotensin-converting enzyme (ACE) inhibitors have been reported to improve insulin sensitivity during either short-term or long-term administration. Recent studies indicate that endothelin-1 (ET-1) has potent glycogenolytic effects in rat hepatocytes and may cause insulin resistance in rat adipocytes. In addition, ET may also have a role in stimulation of the hypothalamic-pituitary-adrenal axis. To test the hypothesis that part of the effect of captopril in enhancing insulin sensitivity may be mediated via ET and/or by glucocorticoids, we measured 24-h urinary excretion of ET and free cortisol before and after short-term treatment with captopril. The 24-h urinary immunoreactive endothelin (IR-ET) excretion decreased significantly (p < 0.05) from 65 +/- 4 ng at baseline to 42 +/- 3 ng after captopril treatment, whereas no significant change in the 24-h urinary free cortisol excretion was observed. Moreover, no significant change in the 24-h urinary IR-ET and free cortisol excretions was noted in the placebo-treated group. We speculate that ACE inhibitors may exert their effect on insulin sensitivity not only by blocking the renin-angiotensin and kinin systems but also by inhibiting production and/or release of ET.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1998

Two measures of physical activity as predictors of bone mass in a young cohort.

OBJECTIVE: To compare the association of two measures of physical activity with bone mass in healthy children and young adults, as part of a larger study on bone mineral acquisition in youth. DESIGN: Cross-sectional observation study. SETTING: General community, outpatient study. PARTICIPANTS: Subjects included 103 non-Hispanic white female (n = 54) and male (n = 49) healthy volunteers aged 9 to 25 years. MAIN OUTCOME MEASURES: Self-reported physical activity was measured by a 3-day activity diary of all activities and a questionnaire designed to capture recreational activities throughout the year. Activity was expressed as hours per week of weight-bearing and non-weight-bearing activity. Bone mass at the hip, spine, and whole body was measured by dual x-ray absorptiometry. RESULTS: The activity measures were not well correlated with each other. In males, weight-bearing and non-weight-bearing activity reported in 3-day diaries was positively associated with bone mass at the hip, spine, and whole body (p < 0.05). Among females, only weight-bearing activity measured by the yearly questionnaires was significantly positively associated with bone mass (p < 0.05). In males and females, weight-bearing activity was more highly correlated with bone mineral than was non-weight-bearing activity. In addition, the associations between activity and bone mass varied by skeletal site. CONCLUSIONS: The association between physical activity and bone mass varied both in direction and in significance depending on the physical activity instrument used. Gender differences were observed in the associations between specific activity instruments, type of activity (weight-bearing and non-weight-bearing), and bone mass at different skeletal sites. Variability associated with the two physical activity measures may contribute to discrepant findings in this study and in the literature.

Adolescent↗
PubMed1998

Effect of intraperitoneal administration of zinc on C57/6J mouse liver--a light microscopic study.

Intraperitoneal administration of zinc chloride in vivo at 14 micrograms/g body weight (equivalent to 1/2 LD50) over a 3 week period induced an increase in liver weight. The mean weight of the livers in zinc-treated C57/6J mice was 50% higher than that of control animals. Image analysis revealed a concomitant and significant increase in the cross-sectional area and perimeter of the hepatocytes in the zinc-treated group. The mean cross-sectional area of hepatocytes in the zinc-treated mice was 337.2 +/- 4.3 microns2 as compared to 224.6 +/- 2.9 microns2 in the control group (p < 0.05, Mann-Whitney test). The mean perimeter of hepatocytes in zinc-treated mice was 72.4 +/- 0.5 micron as compared to 58.9 +/- 0.4 micron in control animals (p < 0.05). It would appear that subacute administration of zinc may result in increase in liver mass due to hypertrophy of the hepatocytes.

Animals↗
PubMed1997

Associations of vitamin C, calcium and protein with bone mass in postmenopausal Mexican American women.

We investigated the associations of vitamin C, calcium and protein intakes with bone mass at the femoral neck and lumbar spine in postmenopausal Mexican American women. Bone mass was measured by dual-energy X-ray absorptiometry (DXA) and expressed as areal (BMD, g/cm2) and volumetric (bone mineral apparent density or BMAD, g/cm3) bone mineral density. Diet was assessed using a modified version of the National Cancer Institute Food Questionnaire, which was administered by trained bilingual interviewers familiar with Mexican dietary practices. Data gathered from 125 subjects were analyzed using multiple linear regression analysis with age, body mass index (BMI), acculturation, years of estrogen use, physical activity, total energy intake, and the nutrient of interest as independent variables. Neither calcium nor calcium/protein ratio was associated with bone mineral density. There was evidence of a positive association between dietary vitamin C intake and femoral neck BMD (beta = 0.0002 g/cm2 per mg/day, SE = 0.00006, p < 0.05), but vitamin C was not associated with lumbar spine bone mass. Further investigation of the role of vitamin C in skeletal health is warranted.

Aged↗