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1.
RSC Adv ; 14(18): 12954-12965, 2024 Apr 16.
Article in English | MEDLINE | ID: mdl-38650687

ABSTRACT

This study attempted to improve the photocatalytic activity of zinc oxide (ZnO) semiconductors in the visible light region by introducing the co-doping of carbon (C) and tantalum (Ta) to ZnO (ZTC) using a simple hydrothermal method with the respective precursors. The obtained uniform ZTC nanoparticles with an average crystal size of 29.30 nm (according to Scherrer's equation) revealed a redshift with a decrease in bandgap (Eg) from 3.04 eV to 2.88 eV, allowing the obtained photocatalyst to absorb the energy of the visible light for photocatalysis. Furthermore, the Zn 2p and Ta 4f core level spectra confirmed the presence of Zn2+ and Ta5+ in the ZTC sample. In addition, the infrared spectra identified hydrogen-related defects (HRDs), while the O 1s spectra indicated the existence of oxygen vacancies (VO). Electrochemical tests revealed improvement in the electron conductivity and charge separation of the obtained materials. To follow, the photocatalytic performance assessment was conducted by varying the C/Zn2+ ratios (5, 10, and 15 mol%) in ZTC samples, the initial RhB concentration (7, 15, and 30 ppm), and the pH of the RhB solution (3.0-10.0). The photodegradation on ZTC samples showed the most effectiveness for a 7 ppm RhB solution with a C/Zn2+ ratio of 10 mol% in the slightly alkaline medium (pH 9.0). Additionally, ZTC also exhibited commendable durability after being reused several times. The nature of RhB photodegradation was proposed and discussed via a mechanism at the end of this work.

2.
RSC Adv ; 14(3): 2048-2060, 2024 Jan 03.
Article in English | MEDLINE | ID: mdl-38196902

ABSTRACT

Cellulose derived from biomass is a renewable resource with numerous applications. Using formic/peroxyformic acid at atmospheric pressure, cellulose nanocrystals (CNC) were isolated from rice husk (RH) in this study. This method was an excellent way to get rid of lignin and hemicelluloses from RH. The cellulose was subsequently acid hydrolyzed by H2SO4 (64%) for 30 minutes at 45 °C. The chemical and microstructure analysis showed that the lignin and hemicellulose contents of raw RH had been eliminated, and the crystallinity content of CNC was 67.16%. According to transmission electron microscopy (TEM) morphological analysis, CNC measured 19 ± 3.3 nm in diameter, 195 ± 24 nm in length, and 10.2 ± 6.8 in aspect ratio. The thermal stability of RH and CNC was also investigated using thermogravimetric analysis (TGA). These encouraging findings demonstrated the potential for reusing RH agricultural waste to create CNC and include nanocomposites as a reinforcing material.

3.
J Environ Manage ; 348: 119252, 2023 Dec 15.
Article in English | MEDLINE | ID: mdl-37864944

ABSTRACT

Steady increase in electricity generation and heavy reliance on coal in Mainland Southeast Asia (M-SEA) create huge pressure on the environment. This study used information collected from individual thermal power plants (TPPs) in M-SEA to calculate emissions of air pollutants and greenhouse gases (GHG) for 2010, 2015 and 2019. The emissions were projected to 2030 following the latest national Power Development Plans. The emission results were analyzed in relation to the power development by country and fuel type, and environmental impacts. The region collective annual TPP emissions in 2019, in Gg/yr, were 27 PM2.5, 77 PM10, 0.7 BC, 4.9 OC, 255 SO2, 451 NOx, 91 CO, 12 NMVOC, 0.4 NH3, 260 CO2, 13 CH4, and 26 N2O. Coal-fired TPPs dominated the emissions of most species while NG-fired contributed the largest amounts of NH3 and CH4. Bi-decadal increase in energy production from TPPs of nearly 3 times is accompanied by 2.7 times increase in emissions. The 2010-2019 period saw average emissions increase by 1.9 times (TPPs' energy production increased 1.6 times), slightly higher than the rate of 1.4 times projected for 2019-2030 (double TPPs' energy production). The current intrusion rate of renewable energy accompanied by phasing-out of old TPPs are still by far insufficient to reverse the emission trend. Aggressive power development in Vietnam with its heavy coal reliance made it the largest emitter in 2019 and the projected for 2030, followed by Thailand. Spatially, higher emissions are seen over locations of large coal-fired TPPs in Vietnam and Thailand. Available rainwater composition monitoring data showed higher deposition amounts of sulfate and nitrate in areas located near or downwind of large TPPs. Significant GHG emissions projected for TPPs in 2030 indicated that TPPs should be the priority for emission reduction to achieve Nationally Determined Contribution targets. Emission database produced by this study can be used in dispersion modeling studies to assess impacts of TPPs on air quality, health, and acid deposition.


Subject(s)
Air Pollutants , Air Pollution , Greenhouse Gases , Climate Change , Air Pollutants/analysis , Air Pollution/analysis , Asia, Southeastern , Coal , Power Plants , Environmental Monitoring/methods
4.
Chemistry ; 29(31): e202300579, 2023 Jun 02.
Article in English | MEDLINE | ID: mdl-36972045

ABSTRACT

A set of nine boronic-acid-derived salicylidenehydrazone (BASHY) complexes has been synthesized in good to very good chemical yields in a versatile three-component reaction. In an extension to previous reports on this dye platform, the focus was put on the electronic modification of the "vertical" positions of the salicylidenehydrazone backbone. This enabled the observation of fluorescence quenching by photoinduced electron transfer (PeT), which can be reverted by the addition of acid in organic solvent (OFF-ON fluorescence switching). The resulting emission is observed in the green-to-orange spectral region (maxima at 520-590 nm). In contrast, under physiological pH conditions in water, the PeT process is inherently decativated, thereby enabling the observation of fluorescence in the red-to-NIR region (maxima at 650-680 nm) with appreciable quantum yields and lifetimes. The latter characteristic supported the application of the dyes in fluorescence lifetime imaging (FLIM) of live A549 cells.

6.
Res Int Bus Finance ; 58: 101489, 2021 Dec.
Article in English | MEDLINE | ID: mdl-36540339

ABSTRACT

On 20 April 2020, the West Texas Intermediate (WTI) crude oil price dropped to negative levels for the first time in history. This study examines the factors underlying the historic oil price fluctuation during the Covid-19 pandemic. The autoregressive distributed lag (ARDL) bounds testing approach incorporating a structural break is applied to the daily series from 17 January to 14 September 2020 to analyze long-run relationships and short-run dynamics. The results reveal that increases in Covid-19 pandemic cases, US economic policy uncertainty, and expected stock market volatility contributed to the fall in the WTI crude oil price, whereas the fall in the global stock markets appears to significantly reduce the fall. Furthermore, the Russia-Saudi Arabia oil price war and speculation on oil futures are shown to play a critical part in the collapse of the oil markets. The findings are consistent with our expectations. Although it is reasonable to assume that the solution to this oil crisis is a pick-up in global oil demand, which will occur only when the novel coronavirus is defeated, this study proposes policy recommendations to cope with the current oil price crash.

7.
Langmuir ; 36(40): 11809-11816, 2020 Oct 13.
Article in English | MEDLINE | ID: mdl-32954736

ABSTRACT

We measure the frictional drag-reducing property of various superhydrophobic metal oxide nanostructures by quantifying their effective slip length. Scalable chemical methods tailored to each metal substrate are applied to grow oxide nanostructures on copper (Cu), aluminum (Al), and titanium (Ti), respectively. In particular, three different types of oxide nanostructures are grown on the titanium substrate by changing the chemical composition to investigate the morphological influence on the slip length. Microchannels containing metal oxide nanostructures are fabricated based on the microfluidic sticker method, while the slip length is unambiguously determined by measuring the ratio of the volume flow rate over the superhydrophobic surface to that over the flat surface simultaneously. The slip length is measured to be 6.8 ± 1.4 µm on Cu nanostructures, while it is measured to be 2.5 ± 0.6 µm on Al nanostructures. For Ti nanostructures, the measured slip lengths range from 1 to 2.5 ± 0.5 µm, where they increase proportionally with the structural pitch of the nanostructures, agreeing with the theoretical predictions. We believe that our results will be useful in applying scalable low-cost metal oxide nanostructures to underwater applications by providing their frictional characteristics.

8.
PLoS One ; 13(12): e0209355, 2018.
Article in English | MEDLINE | ID: mdl-30576345

ABSTRACT

OBJECTIVE: This study aimed to examine the association between age at menarche and a range of cardiovascular disease (CVD) risk factors at 17 and 20 years of age, and whether this was influenced by childhood body mass index (BMI). METHODS: Of the 1413 girls born in the Western Australian Pregnancy Cohort (Raine) Study, 846 had age at menarche recorded. Subsequently 557 underwent metabolic assessment at 17 years and 541 at 20 years. Associations between age at menarche and cardiovascular risk factors, and being in a high-risk metabolic cluster at 17 and 20 years, or having the metabolic syndrome at 20 years, were investigated by linear mixed effects and logistic regressions, respectively. RESULTS: Each year later of onset of menarche was associated with a 0.75 kg/m2 reduction in BMI (coefficient -0.75 [95%CI -1.06, -0.44]), and an approximate 30% reduction in the odds of being in the high-risk metabolic cluster at 17 years (OR = 0.73 [95%CI 0.57, 0.94]) and 20 years of age (OR = 0.68 [95%CI 0.52, 0.87]), and a 40% reduction in the odds of having the metabolic syndrome at 20 years (OR = 0.60 [95% CI 0.41, 0.88]). These data show earlier age at menarche was associated with increased BMI and odds of being in the high-risk metabolic cluster at 17 and 20 years, and increased odds of having the metabolic syndrome at 20 years. However, these associations were no longer statistically significant after adjustment for BMI at age 8 years. Current smoking, alcohol consumption, physical activity, socio-economic status, or hormonal contraceptives use did not affect these associations. CONCLUSIONS: Earlier age at menarche may be indicative of a higher risk profile for CVD in young adulthood. Our findings suggest that targeted interventions to reduce BMI in girls who experience menarche at younger age may reduce CVD risk in the future.


Subject(s)
Body Mass Index , Cardiovascular Diseases/epidemiology , Menarche/physiology , Metabolic Syndrome/epidemiology , Adolescent , Adult , Age Factors , Australia , Birth Weight/physiology , Body Height , Cardiovascular Diseases/metabolism , Cardiovascular Diseases/prevention & control , Child , Female , Follow-Up Studies , Humans , Logistic Models , Longitudinal Studies , Metabolic Syndrome/metabolism , Metabolic Syndrome/prevention & control , Prospective Studies , Risk Factors , Young Adult
9.
Psychoneuroendocrinology ; 66: 118-24, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26802599

ABSTRACT

BACKGROUND: Activation of the hypothalamic-pituitary-adrenal (HPA) axis has been associated with higher levels of cardiovascular (CVD) risk factors in adults. This study aimed to assess the relation between measures of HPA axis activity under resting conditions and CVD risk factors in a general population of adolescents at 17 years. METHODS: A total of 1134 adolescents from the Western Australian Pregnancy Cohort (Raine) Study had phenotypic and socio-demographic data. The associations between HPA axis measures (plasma ACTH, total cortisol, calculated free cortisol, corticosteroid binding globulin (CBG), and salivary cortisol) and a range of cardiovascular risk factors were examined using multivariable linear regression models, with adjustment for gender, adiposity, birth weight, gestational age, and socio-behavioural factors. RESULTS: Plasma total cortisol was positively associated with systolic blood pressure (SBP) (p=0.011), total cholesterol, HDL-cholesterol, and triglycerides (all p<0.001), and hs-CRP (p=0.047). Salivary cortisol was associated positively with HDL-C (p=0.033) and negatively with LDL-cholesterol (p=0.016); plasma calculated free cortisol was positively associated with triglycerides (p=0.006); plasma CBG was positively associated with total cholesterol and HDL-cholesterol (both p<0.001), LDL-cholesterol (p=0.022), and hs-CRP (p=0.001). After correction for multiple comparisons, significant associations remained for total cortisol with total cholesterol, HDL-C, and triglycerides; for calculated free cortisol with triglycerides; and for CBG with HDL-C, total cholesterol, and hs-CRP. Plasma ACTH was not associated with any cardiovascular risk factor. There was no association between BMI and any measure of HPA axis activity. CONCLUSION: In an adolescent population, HPA axis measures under resting conditions are associated with a range of CVD risk factors. Clarification of the mechanisms underlying these associations in adolescence would be an important step in understanding the evolution of adult CVD.


Subject(s)
Cardiovascular Diseases/etiology , Hypothalamo-Hypophyseal System/physiology , Pituitary-Adrenal System/physiology , Pituitary-Adrenal System/physiopathology , Rest/physiology , Adolescent , Basal Metabolism/physiology , Cardiovascular Diseases/epidemiology , Cardiovascular Diseases/physiopathology , Cohort Studies , Female , Humans , Male , Risk Factors , Socioeconomic Factors , Western Australia/epidemiology
10.
J Lipid Res ; 55(4): 758-64, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24577623

ABSTRACT

C-reactive protein (CRP), smoking, and oral contraceptive (OC) use are associated with CVD risk in adults. This study examines the effect of smoking on high-sensitivity CRP (hs-CRP) levels, and the interactive effects of sex and OC use on this relationship in an adolescent cohort. A total of 1,050 adolescents (mean age 17 ± 0.25 years) from the Western Australian Pregnancy Cohort (Raine) Study had anthropometric, lifestyle, and metabolic measures recorded. The association between smoking status and log-transformed hs-CRP was analyzed using multivariable Tobit linear regression models, with adjustment for adiposity, lifestyle, and early-life confounders. A three-level variable (girls not using OCs, girls using OCs, and boys) was employed to assess the interactive effects of sex, OC use, and smoking. Smoking associated with higher hs-CRP levels in girls not using OCs (b = 0.571; P = 0.001), but not in girls using OCs (b = -0.117; P = 0.598) or in boys (b = 0.183; P = 0.2). OC use in nonsmoking girls was the strongest factor associated with higher hs-CRP levels (b = 1.189; P < 0.001). This study has demonstrated a more robust effect of smoking on hs-CRP levels in girls not using OCs compared with boys. The findings may explain why CVD risk conferred by smoking is higher in women than in men.


Subject(s)
C-Reactive Protein/metabolism , Smoking/epidemiology , Adolescent , Alcohol Drinking/blood , Alcohol Drinking/epidemiology , Biomarkers/blood , Cardiovascular Diseases/etiology , Contraceptives, Oral/adverse effects , Female , Follow-Up Studies , Humans , Male , Multivariate Analysis , Risk Factors , Sex Distribution , Smoking/adverse effects , Smoking/blood
11.
J Clin Endocrinol Metab ; 98(5): 2126-35, 2013 May.
Article in English | MEDLINE | ID: mdl-23633198

ABSTRACT

BACKGROUND: High-density lipoprotein-cholesterol (HDL-C) levels are influenced by gender and by genetic and environmental factors. We aimed to assess the impact of passive smoking exposure since birth on HDL-C levels of nonsmoking adolescents at age 17 years and to determine whether there was a gender difference in the relationship between smoking exposure and HDL-C. METHODS: A total of 804 nonsmoking adolescents with biochemical, anthropometric, and lifestyle data from a cohort of 1754 adolescents (mean age, 17 ± 0.25 y) of the Western Australian Pregnancy Cohort (Raine) Study had data of maternal smoking during pregnancy and smoking exposure in the household over 17 years. HDL-C was analyzed using multivariable linear regression, with adjustment for early-life, adiposity, and current lifestyle confounders. RESULTS: HDL-C levels were significantly lower in girls exposed to passive smoking compared to those not exposed (regression coefficient b = -0.09 [95% confidence interval, -0.15, -0.03]); this was not observed in boys (b = 0.02 [95% confidence interval, -0.04, 0.08]), with a significant sex interaction P = .009. The effects of passive smoking in girls persisted after adjusting for oral contraceptive use. CONCLUSIONS: This study has shown a gender difference in the relationship between passive smoking exposure since birth and HDL-C in late adolescence. Exposure to passive smoking in girls could have adverse consequences on their risk of cardiovascular disease in adulthood. These findings reinforce the need for future public health measures to reduce children's exposure to passive smoking.


Subject(s)
Cardiovascular Diseases/epidemiology , Cardiovascular Diseases/etiology , Cholesterol, HDL/blood , Tobacco Smoke Pollution , Adiposity , Adolescent , Birth Weight , Breast Feeding , Cohort Studies , Family Characteristics , Female , Follow-Up Studies , Humans , Life Style , Longitudinal Studies , Male , Maternal Behavior , Models, Biological , Risk , Sex Characteristics , Western Australia/epidemiology
12.
Eur J Prev Cardiol ; 20(6): 947-55, 2013 Dec.
Article in English | MEDLINE | ID: mdl-22790885

ABSTRACT

AIMS: Lifestyle behaviours established during adolescence may adversely affect blood pressure (BP) and contribute to gender differences in cardiovascular risk in adulthood. We aimed to assess the association of health behaviours with BP in adolescents, using data from the Western Australian Pregnancy (Raine) Study. METHODS: Cross-sectional analysis on 1248 Raine Study adolescents aged 17 years, to examine associations between lifestyle factors and BP. RESULTS: Boys had 8.97 mmHg higher systolic BP, as compared with girls. The 30% of girls using oral contraceptives (OC) had 3.27 and 1.74 mmHg higher systolic and diastolic BP, respectively, compared with non-users. Alcohol consumption in boys, increasing body mass index (BMI) and the sodium-potassium ratio were associated with systolic BP. We found a continuous relationship between BMI and systolic BP in both genders; however, the gradient of this relationship was significantly steeper in boys, compared with girls not taking OC. In boys, systolic BP was 5.7 mmHg greater in alcohol consumers who were in the upper quartile of BMI and the urinary sodium-potassium ratio compared with teetotallers in the lowest quartile. In girls, systolic BP was 5.5 mmHg higher in those taking OC, in the highest BMI and urinary sodium-potassium ratio quartile as compared to those not taking the OC pill and in the lowest quartile. CONCLUSION: In addition to gender-related differences in the effects of adiposity on BP, we found lifestyle-related health behaviours such as high salt intake for both sexes, consumption of alcohol in boys, and OC use in girls were important factors associated with BP measurements in late adolescence. This suggests that gender-specific behavioural modification in adolescence may prevent adult hypertension.


Subject(s)
Alcohol Drinking/adverse effects , Blood Pressure , Contraceptives, Oral/adverse effects , Hypertension/etiology , Life Style , Adiposity , Adolescent , Adolescent Behavior , Age Factors , Body Mass Index , Cross-Sectional Studies , Female , Humans , Hypertension/diagnosis , Hypertension/physiopathology , Hypertension/prevention & control , Male , Obesity/complications , Obesity/diagnosis , Obesity/physiopathology , Risk Factors , Risk Reduction Behavior , Sex Factors , Sodium Chloride, Dietary/adverse effects , Western Australia/epidemiology
13.
J Clin Endocrinol Metab ; 97(6): E1014-22, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22442267

ABSTRACT

CONTEXT: Birth weight and childhood adiposity are associated with subsequent cardiovascular risk. OBJECTIVE: We investigated the associations between metabolic clusters in young adults with body fat distribution from early childhood, focusing on sex differences. DESIGN, SETTING, AND PATIENTS: A total of 1053 17 yr olds from an Australian birth cohort had measures of anthropometry, blood pressure, and fasting insulin, glucose, and lipids. MAIN OUTCOME MEASURES: Two-step cluster analysis identified 17 yr olds at high metabolic risk. The two risk groups were compared by sex with regard to birth weight and serial anthropometry, including skinfold thickness from nine time-points. RESULTS: The "high-risk" metabolic cluster at age 17 yr included 16% of males and 19% of females. Compared to the "low-risk" group, the high-risk cluster participants had greater waist circumference, triglycerides, insulin, and systolic blood pressure and lower high-density lipoprotein-cholesterol (all P <0.0001). There was a significant birth weight by sex interaction upon the metabolic cluster outcome (P = 0.011). Compared to their low-risk counterparts, females in the high-risk cluster at 17 yr were heavier from birth (odds ratio, 1.8; 95% confidence interval, 1.0, 3.2) (P = 0.034), with consistently higher body mass index and skinfold thickness thereafter. In contrast, there was no statistical difference in birth weight between high- and low-risk males (odds ratio, 0.62; 95% confidence interval, 0.38, 1.02). CONCLUSIONS: These data show sexual dimorphism in effects of early life body mass index and fat distribution upon cardiometabolic risk factors. Females in a contemporary population are particularly prone to increased risk when born heavier. This has implications for targeted prevention of obesity and metabolic diseases with increasing maternal obesity and gestational diabetes.


Subject(s)
Adiposity , Cardiovascular Diseases/epidemiology , Diabetes Mellitus, Type 2/epidemiology , Metabolic Syndrome/epidemiology , Obesity/epidemiology , Sex Characteristics , Adolescent , Birth Weight , Body Mass Index , Child , Child, Preschool , Female , Follow-Up Studies , Humans , Incidence , Infant , Longitudinal Studies , Male , Pregnancy , Risk Factors , Sex Distribution
14.
Facial Plast Surg ; 28(1): 102-15, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22418820

ABSTRACT

The ideal facial rejuvenation algorithm is comprised of an appropriate combination of procedures, thoughtfully chosen from an assortment of reliable alternatives, that when skillfully performed provide both short- and long-term enhancement to the undesirable conditions of aging that exists at the time of treatment. In 2010, the senior author published the first scientific article in which a condition-specific classification system and a treatment plan algorithm were applied to the discipline of facial rejuvenation. In the landmark article, the senior author reviewed his surgical experience of more than 5000 face-lifts and grouped patients into five major categories (or stages), based upon the extent of aging identified in various regions of the face and neck and the procedures performed to correct them. The criteria (that have now been suggested on a facial aging worksheet) were recorded in a data blank comprised of a first-generation worksheet. Once the data were collected--and using algorithmic charts for each region and/or facial feature--the most appropriate plan of action for a given patient was created. The sole objective in sharing the senior author's methodology was to launch a scholarly discussion among physicians and surgeons involved in the various disciplines that provide rejuvenation procedures on the face, head, and neck. From such a debate would, hopefully, emerge a definitive algorithmic system--one based squarely on the venerable ethics of medicine, coupled with the appropriate application of and skillful performance of the fundamental principles of surgery. A single, science-based system would restore order to a noble discipline, currently being challenged by narcissism, gimmickry, and commercialization. The implementation of a system rooted in universal truths would require its advocates to agree upon a common "language," the implementation of which allows aesthetically focused surgeons to share both new ideas and time-tested experiences. More importantly, a condition-specific system matches each potential patient's problems--at every age--with the appropriate facial rejuvenation treatment plan, restoring the ideals of science and art to the profession. Initially provided in a consumer information book devised to assist patients with understanding the advantages of personalized treatment plans, the senior author later shared his practices and evolving system with colleagues attending conventions, seminars, and courses. Only after he was convinced that his system could be of benefit to physicians and surgeons from a variety of backgrounds was it offered to the peer-reviewed medical literature. Clearly, a plethora of techniques and materials are available for facial rejuvenation; however, only the ones deemed to be worthy of consideration were included. In practice--and in this presentation--the authors expanded the scope of the previously published article and offer a user-friendly, condition-specific worksheet and algorithmic tables designed to make it easier for surgeons to select the right combinations of procedures--at the right time in a patient's life. Although imitations potentiate an environment of disharmony, the authors remain committed to enabling the evolution of a single facial rejuvenation classification system, one that--with the input of like-minded scholars--could restore needed order to a branch of the medical profession that, in recent years, seems to have lost its focus.


Subject(s)
Aging , Rejuvenation , Rhytidoplasty/classification , Skin Aging , Blepharoplasty , Chemexfoliation , Classification , Dermabrasion , Ear, External/surgery , Health Status , Humans , Lip/surgery , Lipectomy , Normal Distribution , Rhytidoplasty/methods , Terminology as Topic
15.
Clin Cancer Res ; 17(23): 7265-72, 2011 Dec 01.
Article in English | MEDLINE | ID: mdl-21998334

ABSTRACT

PURPOSE: To assess aldehyde dehydrogenase (ALDH) expression in adult human and murine submandibular gland (SMG) stem cells and to determine the effect of ALDH3 activation in SMG stem cell enrichment. EXPERIMENTAL DESIGN: Adult human and murine SMG stem cells were selected by cell surface markers (CD34 for human and c-Kit for mouse) and characterized for various other stem cell surface markers by flow cytometry and ALDH isozymes expression by quantitative reverse transcriptase PCR. Sphere formation and bromodeoxyuridine (BrdUrd) incorporation assays were used on selected cells to confirm their renewal capacity and three-dimensional (3D) collagen matrix culture was applied to observe differentiation. To determine whether ALDH3 activation would increase stem cell yield, adult mice were infused with a novel ALDH3 activator (Alda-89) or with vehicle followed by quantification of c-Kit(+)/CD90(+) SMG stem cells and BrdUrd(+) salispheres. RESULTS: More than 99% of CD34(+) huSMG stem cells stained positive for c-Kit, CD90 and 70% colocalized with CD44, Nestin. Similarly, 73.8% c-Kit(+) mSMG stem cells colocalized with Sca-1, whereas 80.7% with CD90. Functionally, these cells formed BrdUrd(+) salispheres, which differentiated into acinar- and ductal-like structures when cultured in 3D collagen. Both adult human and murine SMG stem cells showed higher expression of ALDH3 than in their non-stem cells and 84% of these cells have measurable ALDH1 activity. Alda-89 infusion in adult mice significantly increased c-Kit(+)/CD90(+) SMG population and BrdUrd(+) sphere formation compared with control. CONCLUSION: This is the first study to characterize expression of different ALDH isozymes in SMG stem cells. In vivo activation of ALDH3 can increase SMG stem cell yield, thus providing a novel means for SMG stem cell enrichment for future stem cell therapy.


Subject(s)
Adult Stem Cells/cytology , Adult Stem Cells/enzymology , Aldehyde Dehydrogenase/metabolism , Allyl Compounds/pharmacology , Benzodioxoles/pharmacology , Enzyme Activators/pharmacology , Submandibular Gland/cytology , Aldehyde Dehydrogenase/biosynthesis , Aldehyde Dehydrogenase/genetics , Animals , Antigens, CD34/analysis , Antigens, Ly/analysis , Bromodeoxyuridine/metabolism , Enzyme Activation , Head and Neck Neoplasms/radiotherapy , Humans , Hyaluronan Receptors/analysis , Membrane Proteins/analysis , Mice , Mice, Inbred C57BL , Proto-Oncogene Proteins c-kit/analysis , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , Submandibular Gland/metabolism , Thy-1 Antigens/analysis , Xerostomia/etiology
16.
Article in Korean | WPRIM (Western Pacific) | ID: wpr-67409

ABSTRACT

PURPOSE: To determine the clinical and demographic factors associated with long-term remission of valproate(VPA) therapy in childhood absence epilepsy. METHODS: Fifty-six cases of childhood and juvenile absence epilepsy were identified by reviewing of Electroencephalographic records and medical charts. Thirty-six cases were initially treated with VPA. Factor associated with responsiveness were identified by uni- and mutivariate logistic regression. RESULTS: Twenty-seven patient achieved long-term remission(75%). Failure to achieve remission was more likely if the initial treatment of VPA had failed than if it was successful(53% versus 90.4%, P<0.02) was also associated with failure of long-term remission. Lamotrigine was more efficacious add-on drug than Ethosuximide(63.6% vs 25% P=0.04). CONCLUSION: Long-term seizure remission was related to the patient's initial response to VPA.


Subject(s)
Humans , Demography , Epilepsy , Epilepsy, Absence , Logistic Models , Seizures , Triazines , Valproic Acid
17.
Vasc Endovascular Surg ; 43(6): 567-70, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19828586

ABSTRACT

PURPOSE: Radiofrequency ablation (RFA) of veins >12 mm in diameter has been a controversial subject since the first-generation device was submitted for Food and Drug Administration (FDA) approval. Veins >12 mm were excluded in the initial study. Many insurance carriers used >12 mm size as reason to not approve the procedure. As the concept of tumescent anesthesia was better communicated, RFA was used for large veins. The 12-mm size limit was not used in the studies for the newer ClosureFAST catheter approval, yet remains in force with some insurance companies. Our objective was to determine whether vein diameter >12 mm had effect on closure rates with the Closure-FAST catheter. METHODS: ClosureFAST RFA was used to eliminate saphenous reflux in consecutive cases in 1 center. Retrospective analysis was performed on prospectively gathered data. Veins were divided into < or =12 mm diameter (group A) or >12 mm diameter (group B). Duplex scans were scheduled for 2 to 5 days and 6 months postprocedure. RESULTS: A total of 338 great and small saphenous veins were treated, 246 saphenous veins in group A (mean 8 +/- 2 mm) and 96 in group B (mean 17 +/- 4 mm). Early duplex showed complete closure in 231 veins in group A (94%) and 92 veins in group B (96%; NS). The remaining veins showed partial closure with none showing retrograde flow. Six-month duplex scans were completed in 155 veins. Complete closure was seen in 110 veins in group A (98%) and 43 veins in group B (100%; NS). All veins partially open on early scan had closed by 6 months. The 2 veins open at 6 months in group A were closed on initial scan. CONCLUSIONS: Vein diameter >12 mm had no effect on closure rate with the ClosureFAST catheter.


Subject(s)
Catheter Ablation , Saphenous Vein/surgery , Varicose Veins/surgery , Adult , Aged , Catheter Ablation/adverse effects , Catheter Ablation/instrumentation , Female , Humans , Male , Middle Aged , Retrospective Studies , Saphenous Vein/diagnostic imaging , Time Factors , Treatment Outcome , Ultrasonography, Doppler, Duplex , Varicose Veins/diagnostic imaging
18.
Am Surg ; 74(7): 644-53, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18646483

ABSTRACT

We evaluated the use of duodenal derotation as a surgical option for superior mesenteric artery syndrome (SMAS) in two groups of young patients. Sixteen patients with SMAS diagnosed by barium upper gastrointestinal series (UGI) from 1974 to 2001, and six patients diagnosed by computerized tomography with three-dimensional reconstructions (3D CT) from 2001 to 2007 were referred to our surgical service, 19 of whom underwent duodenal derotation as the primary surgical treatment after a failed trial of conservative treatment. The main measured outcomes were the resolution of typical symptoms of SMAS and the development of long-term surgical complications. Of the first 16 patients, three (19%) responded to nasojejunal feedings. Of 13 patients undergoing derotation, only one (7.7%) failed derotation and required a gastrojejunostomy bypass, whereas 12 (92%) became asymptomatic after the derotation procedure. After a mean follow-up of 5.13 years (range 0.1-15), two patients (15%) presented with small bowel obstructions and were treated with a simple lysis of the adhesion. All six patients from 2001 to 2007 responded well to surgical derotation. Overall, duodenal derotations successfully relieved symptoms in 18 out of 19 (95%) patients with SMAS, with two (11%) major long-term surgical complications. No volvulus was observed in our patients at the mean follow-up of 4.37 years.


Subject(s)
Digestive System Surgical Procedures/methods , Duodenal Diseases/surgery , Duodenum/surgery , Superior Mesenteric Artery Syndrome/surgery , Adolescent , Child , Child, Preschool , Diagnosis, Differential , Duodenal Diseases/congenital , Duodenal Diseases/diagnostic imaging , Duodenum/abnormalities , Female , Follow-Up Studies , Humans , Imaging, Three-Dimensional , Infant , Male , Postoperative Complications , Retrospective Studies , Superior Mesenteric Artery Syndrome/diagnostic imaging , Superior Mesenteric Artery Syndrome/etiology , Time Factors , Tomography, X-Ray Computed/methods , Treatment Outcome
19.
Korean Journal of Pediatrics ; : 1329-1335, 2008.
Article in Korean | WPRIM (Western Pacific) | ID: wpr-103106

ABSTRACT

PURPOSE: This study aimed to determine the best cutoff line for insulin-like growth factor (IGF)-I and insulin-like growth factor binding protein (IGFBP)-3 to discriminate between growth hormone deficiency (GHD) patients and the control group. METHODS: Two hundred thirty subjects with normal controls (129 boys and 101 girls, aged 7-15 years), 14 patients with complete GHD (12 boys and 2 girls), and 17 patients with partial GHD (9 boys and 8 girls) were studied. IGF-I serum concentrations were measured by radioimmunoassay (RI), and IGFBP-3 concentrations were measured by immunoradiometric assay (IRMA). RESULTS: The receiver operating characteristic (ROC) plot analysis showed that the best IGF-I and IGFBP-3 cutoff line was at -1 standard deviation (SD). By comparing IGF-I serum levels of GHD children within 1 SD of normal control, we determined the sensitivity (S) (87.5-100%) and specificity (Sp) (80-84.6%) according to the age group. For IGFBP-3 , we determined the following values: S (58.7-85.7%) and Sp (79.2-85.5%). Eleven of 1 4 patients with complete GHD (78.5%) and 16 of 17 patients with partial GHD (94.1%) had IGF-I concentrations equal to or below -1 SD of the control group mean. Ten of 12 complete GHD children (83.3%) and 13 of 17 partial GHD children (76.5%) had IGFBP-3 concentrations equal or below -1 SD of the control group mean. CONCLUSION: We conclude that the measurement of IGF-I and IGFBP-3 concentrations might provide essential supplementary data in the diagnostic evaluation of patients with GHD. Our results support the need to use cutoff lines based on below -1 SD of the control.


Subject(s)
Aged , Child , Humans , Carrier Proteins , Growth Hormone , Immunoradiometric Assay , Insulin-Like Growth Factor Binding Protein 3 , Insulin-Like Growth Factor I , Radioimmunoassay , ROC Curve , Sensitivity and Specificity
20.
Article in Korean | WPRIM (Western Pacific) | ID: wpr-112351

ABSTRACT

PURPOSE: Moyamoya disease is a chronic cerebrovascular illness characterized by bilateral stenoses or occlusions of the arteries around the circle of Willis with prominent collateral circulation. We studied 36 children and adolescents with Moyamoya disease to evaluate the clinical features and outcomes. METHODS: Records were reviewed of 36 pediatric patients admitted at the Busan Paik Hospital for Moyamoya disease between January 2000 and July 2007. The clinical records were reviewed in terms of the patient profiles, imaging findings, surgical techniques, and pathologic findings. RESULTS: Overall clinical features, responses to treatment and outcome were nearly same as those of other previous reports in Korea as well as the other countries. The mean age of onset was 8 years and 5 months and the ratio of male to female was 1:1.2. Ischemia was more often than infarction(5.6: 1). Half of the patients had conservative therapy and 17 cases(47%) were treated with EDAS. CONCLUSION: The clinical features of childhood Moyamoya disease are similar to the result from other studies in Korea.


Subject(s)
Adolescent , Child , Female , Humans , Male , Age of Onset , Arteries , Circle of Willis , Collateral Circulation , Constriction, Pathologic , Ischemia , Korea , Moyamoya Disease
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