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Dive into the research topics where Malcolm Koo is active.

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Featured researches published by Malcolm Koo.


Annals of Human Biology | 1997

Accuracy of short-term recall of age at menarche

Malcolm Koo; Thomas E. Rohan

This study was conducted as part of the third annual follow-up of a cohort of 657 girls to test the accuracy of short-term recall of age at menarche. During the first and second annual follow-ups of the cohort, 101 girls had reported menarche. We sent questionnaires to these subjects at the third annual follow-up and asked them to recall the month and year of their menarche. Eighty-eight respondents returned their questionnaires with the relevant information. Overall, 59.1% of the respondents were able to recall their menarche with the exact month and year. The mean recall interval was 430 days. When the data were grouped by the interval of recall, higher accuracy was observed with a shorter interval of recall. With a mean interval of recall of 323 days, 66.1% of the subjects were able to recall their menarche correctly, whereas with a mean interval of 649 days, only 44.8% of the subjects were able to recall correctly.


Nutrition and Cancer | 1991

Long-term effect of Bifidobacteria and neosugar on precursor lesions of colonic cancer in CF1 mice

Malcolm Koo; A. Venketeshwer Rao

This investigation was undertaken to study the role of Bifidobacteria and bifidogenic factor Neosugar in the process of 1,2-dimethylhydrazine-induced colonic carcinogenesis in CF1 mice. Intestinal colonization and selective proliferation of Bifidobacteria were achieved by oral administration of indigenous Bifidobacteria and the incorporation of 5% Neosugar in the diet of animals. The Bifidobacteria were isolated from the feces of CF1 mice and were identified to be Bifidobacterium pseudolongum biovar b. This incidence of aberrant crypts and foci were significantly lower 38 weeks after the last injection of the carcinogen in animals fed Bifidobacteria than in animals treated with the carcinogen alone. The aberrance also appeared to be confined to the more distal end of the colon in animals fed bifidogenic diet. Such changes in the precursor lesions of colonic carcinogenesis are presumably due to the increase in the number of Bifidobacteria and their acidifying action in the lower intestinal tract of the animals.


Journal of Alternative and Complementary Medicine | 2009

Effects of Music and Essential Oil Inhalation on Cardiac Autonomic Balance in Healthy Individuals

Shu-Ming Peng; Malcolm Koo; Zer-Ran Yu

OBJECTIVE The purpose of the present study was to investigate the effect of listening to soft music or inhaling Citrus bergamia aroma on autonomic nervous system activity in young healthy individuals. STUDY DESIGN, LOCATION, AND SUBJECTS: This single-institution study was an open-label randomized controlled trial carried out on 114 healthy undergraduate students at a university located in south Taiwan. INTERVENTION Participants were randomly allocated to one of four study groups including (1) a music group, (2) an aroma group, (3) a combined music and aroma group, and (4) a control group. Participants in the music group were asked to listen to preselected soft music for 15 minutes, and those in the aroma group were asked to inhale Citrus bergamia essential oil vapor generated from an ultrasonic atomizer for 15 minutes. OUTCOME MEASURE The outcome measure involved heart rate variability (HRV) indices measured before and after the intervention. The low frequency (LF) and high frequency (HF) components of the HRV were used to quantify modulation of the sympathetic and parasympathetic branches of the autonomic nervous system. RESULTS The percentage changes of normalized LF (p = 0.003), normalized HF (p = 0.001), and the ratio of LF to HF (p < 0.001) were significantly different among the four groups. Tukeys post hoc analysis revealed that the percentage change of normalized LF and HF were significantly different between the control group and the music group. For the percentage change of the ratio of LF to HF, the negative change in the music group, the aroma group, and the combined group was significantly different from that of the increase in the control group. In addition, no significant differences were found in the percentage changes in systolic blood pressure, diastolic blood pressure, and mean heart rate in the four groups. CONCLUSIONS Listening to soft music and inhaling Citrus bergamia essential oil was found to be an effective method of relaxation, as indicated by a shift of the autonomic balance toward parasympathetic activity in young healthy individuals.


The American Journal of Gastroenterology | 2014

A patient-blinded randomized, controlled trial comparing air insufflation, water immersion, and water exchange during minimally sedated colonoscopy.

Yu-Hsi Hsieh; Malcolm Koo; Felix W. Leung

OBJECTIVES:Minimal sedation obviates patient recovery burdens, but intolerable pain limits success of cecal intubation. Painless or minimally uncomfortable insertion ensures success of cecal intubation, current patient satisfaction, and willingness to repeat future colonoscopy with minimal sedation. Water immersion (WI) and water exchange (WE), when separately compared with air insufflation (AI), significantly reduced insertion pain. To assess comparative effectiveness, we conducted a randomized controlled trial with head-to-head comparison of these three methods. We hypothesized that WE could produce the highest proportion of patients reporting painless insertion.METHODS:This prospective patient-blinded trial (NCT01535326) enrolled minimally sedated (25 mg intramuscular meperidine) patients randomized to AI, WI, or WE (90 patients/group) to aid insertion. The previously validated primary outcome was the proportion of patients reporting painless insertion.RESULTS:Painless insertion was reported by 30.0% (AI), 43.3% (WI), and 61.1% (WE) of patients (P<0.001). Multivariate logistic regression analysis revealed that, after adjusting for gender, body mass index, abdominal compression, position change, insertion time to cecum, and length of scope at cecum, only WE was significantly associated with painless insertion compared with AI (odds ratio (OR)=0.08, 95% confidence interval (CI)=0.03–0.24, P<0.001) or WI (OR=0.14, 95% CI=0.05–0.40, P<0.001). Adenoma detection rate (ADR) in the right (cecum and ascending) colon was 11.1% (AI), 14.4% (WI), and 26.7% (WE) (P=0.015). The limitations included single site study with unblinded colonoscopist and assistant.CONCLUSIONS:This head-to-head comparison of AI vs. WI vs. WE confirmed that WE was superior to WI and AI, with a significantly greater proportion of patients reporting painless insertion. The significantly higher ADR in the right colon in the WE group warrants further investigations.


Medicine and Science in Sports and Exercise | 1999

Comparison of four habitual physical activity questionnaires in girls aged 7-15 yr.

Malcolm Koo; Thomas E. Rohan

PURPOSE Questionnaires provide a practical approach to measuring physical activity in children and adolescents, particularly for large-scale epidemiological studies. The purpose of the present study was to compare four habitual physical activity questionnaires and to assess their long-term reliabilities. METHODS Subjects were female, aged 7-15 yr (and their parents), who participated in a cohort study in which predictors of the onset of menarche were being investigated. Questionnaires consisted of three single-item and one multi-item habitual physical activity questions and were sent to the 640 participants. Test-retest reliability of the questionnaires was assessed on 100 randomly selected participants 11 months later. RESULTS The Spearmans correlation coefficient was highest (r = 0.40) between the Godin-Shephard Score and the Perspiration Score and was lowest (r = 0.10) between the Stairs Score and the Specific Activity Score. The correlation coefficients were higher when the questionnaires were reported to have been completed by the parents alone, rather than by parents with the assistance of their daughters. The test-retest reliabilities were r = 0.44 for the Perspiration Score, r = 0.59 for the Stairs Score, r = 0.48 for the Godin-Shephard Score, and r = 0.53 for the Specific Activity Score. The reliabilities were higher when the retest was reported to have been completed by the parents alone. CONCLUSIONS This study suggests that the Perspiration Score, the Godin-Shephard Score, and the Specific Activity Score may provide simple and practical measures of habitual physical activity for children and adolescents.


Nutrition and Cancer | 1995

Effect of soybean saponins and gypsophilla saponin on growth and viability of colon carcinoma cells in culture

Mi‐Kyung Sung; Cyril W.C. Kendall; Malcolm Koo; A. Venketeshwer Rao

The effects of soybean saponins (SS) and gypsophilla saponin (GS) on the growth and viability of colon tumor (HCT-15) cells in culture were investigated. Cells were incubated in various concentrations of saponins for 1 hour (short term) or 48 hours (long term). Cell growth and viability were monitored at 24 and 48 hours. SS and GS inhibited cell growth and reduced cell viability in a dose-dependent manner in long-term treatment. The viability of cells was also reduced by short-term treatment with GS. The saponins differed in their effects on cell surface morphology: GS induced a rough and granular cell surface, whereas SS-treated cells displayed only minor morphological alterations. Changes in membrane permeability were assessed by measuring leakage of the cytoplasmic enzyme lactate dehydrogenase from cells. GS showed a concentration-dependent increase in lactate dehydrogenase leakage, whereas SS did not exhibit this effect. These results suggest that SS and GS have a significant growth-inhibitory effect on colon tumor cells in culture. However, it would appear that they are acting through different mechanisms.


Public Health Nutrition | 2002

A cohort study of dietary fibre intake and menarche

Malcolm Koo; Thomas E. Rohan; Meera Jain; John R. McLaughlin; Paul Corey

OBJECTIVE To evaluate the influence of dietary fibre on menarche in a cohort of pre-menarcheal girls. DESIGN Prospective cohort study. SETTING Ontario, Canada. SUBJECTS Free-living pre-menarcheal girls (n = 637), 6 to 14 years of age. METHODOLOGY Information on dietary intake, physical activity and date of menarche was collected at baseline and was updated annually by self-administered questionnaires for three years. Cox proportional hazards models were used to evaluate the association between dietary fibre and menarche, adjusting for age at entry to the study and potential confounders. RESULTS A higher intake of energy-adjusted dietary fibre was associated with a lower risk of (i.e. a later age at) menarche (relative hazard 0.54, 95% confidence interval (CI) 0.31-0.94 for highest vs. lowest quartile, P for trend = 0.027). At the fibre component level, a higher intake of energy-adjusted cellulose was associated with a lower risk of menarche (relative hazard 0.45, 95% CI 0.26-0.76, P for trend = 0.009). CONCLUSIONS The findings are consistent with the hypothesis that pre-menarcheal dietary intake can influence menarche.


Cancer Letters | 1992

Effect of dietary oxidized cholesterol on azoxymethane-induced colonic preneoplasia in mice

Cyril W.C. Kendall; Malcolm Koo; Ellen Sokoloff; A. Venket Rao

The effect of cholesterol and oxidized cholesterol on azoxymethane-induced colonic preneoplasia was evaluated in C57BL/6J and BALB/cJ mouse strains. Mice were fed either a control AIN 76 semisynthetic diet or the control diet supplemented with 0.1% or 0.3% cholesterol, or 0.1% or 0.3% oxidized cholesterol for an 8-week period. For the first 4 weeks of the experiment, mice received weekly injections of azoxymethane (5 mg/kg body weight). Dietary cholesterol increased fecal concentrations of neutral and acid sterols. A dose-response relationship was observed in both mouse strains between the level of dietary cholesterol or oxidized cholesterol and formation of preneoplastic aberrant crypt foci. Enhanced cell proliferation along with alterations in several crypt morphometric parameters were also observed. These anomalies were enhanced to a greater extent by oxidized cholesterol. This data shows a very strong effect of cholesterol in enhancing the development of preneoplastic lesions in chemically induced cells. It also demonstrated that the state of oxidation of cholesterol influences colonic preneoplasia. This factor has been overlooked in previous animal experiments.


Journal of Pain and Symptom Management | 2010

Association Between Cardiovascular Autonomic Functions and Time to Death in Patients With Terminal Hepatocellular Carcinoma

Jui-Kun Chiang; Malcolm Koo; Terry B.J. Kuo; Chin-Hua Fu

CONTEXT A better time-to-death (TTD) prediction can facilitate decision-making processes related to plans for providing effective end-of-life care for patients in hospice wards. OBJECTIVE To explore the association of cardiovascular autonomic functions with TTD in patients with terminal hepatocellular carcinoma. METHODS A prospective study was conducted with 33 patients with hepatocellular carcinoma recruited from the hospice ward of a regional hospital in Chiayi county, Taiwan. Serum creatinine, serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase, blood urea nitrogen (BUN), and serum albumin were measured on the admission day. Cardiovascular autonomic functions were evaluated by frequency-domain measures of heart rate variability (HRV) on admission. RESULTS TTD was significantly associated with total spectrum power (TP) (r=0.55, P=0.001) and high frequency (HF power) (r=0.44, P=0.010) of HRV measurement. The accuracy of within-one-week TTD prediction was 67% for TP and HF power. The accuracy of within-two-week TTD prediction was 82% for TP and 73% for HF. In addition, TTD of the patients was also significantly associated with serum creatinine (r=-0.42, P=0.015), serum albumin (r=-0.46, P=0.007), and BUN (r=-0.44, P=0.010). CONCLUSION This is the first study to evaluate the association between cardiovascular autonomic functions and TTD in patients with terminal hepatocellular carcinoma. The inclusion of HRV measurement in prognostic models may improve accuracy in TTD prediction and, hence, facilitate medical decision making in hospice care.


Tobacco Control | 2005

China: tobacco museum’s “smoky” health information

Shanta Varma; Karen Choi; Malcolm Koo; Harvey A. Skinner

Objective: To assess the effect of the opening of the Taiwanese cigarette market on cigarette consumption, changes in market share, and the effects on tobacco control efforts. Methods: With the use of key word “Taiwan”, the Legacy Tobacco Documents Library of the University of California, San Francisco, was searched for internal documents related to smuggling activities, promotion of light cigarettes, and market share analyses in Taiwan. Age adjusted smoking rates and cigarette and betel quid consumption before and after market opening were compared. Results: By 2000, the market share of imported cigarettes increased from less than 2% in 1986 to nearly 50%, and per capita cigarette consumption increased 15% following market opening. Because of the sharp increase in smuggling, with contraband cigarettes being as popular as legal imports, and the rapid proliferation of retail outlets, such as betel quid stalls, the market penetration by foreign tobacco companies was greater in Taiwan than among the other Super 301 Asian countries. Aggressive cigarette marketing strategies were associated with a 6% increase in adult male smoking prevalence, and with a 13% increase in the youth rate, within three years after market opening. The market opening also had an incidental effect on increasing the popularity of betel quid. Betel quid chewing has since become a major public health problem in Taiwan. Conclusion: The opening of the cigarette market in 1987 had a long lasting impact on Taiwan. It increased smoking prevalence and the market has become dominated by foreign companies. The seriousness of smuggling and its associated loss of revenue by the government, the extent of increased youth smoking and its associated future health care costs, and the increased use of betel quid and the associated doubling of oral cancer mortality rates each pose significant problems to Taiwan. However, the market opening galvanised anti-smoking sentiment and forced the government to initiate and intensify a series of tobacco control efforts.

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Felix W. Leung

University of California

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Jui-Kun Chiang

Chia Nan University of Pharmacy and Science

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Be-Jen Wang

National Chiayi University

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