1.Environmental Health And Building Related Illnesses
Stephen Ambu ; Wan-Loy Chu ; Joon-Wah Mak ; Shew-Fung Wong ; Li-Li Chan ; Siew-Tung Wong
International e-Journal of Science, Medicine and Education 2008;2(supp1):11-18
Malaysia has good environmental laws to
protect the outdoor environment and public health.
However there are no laws governing indoor air quality
(IAQ) and the knowledge among the public about its
importance is also lacking. Environmental professionals
think it is not a priority and this influences the policy
decisions in the country. Therefore there is a need to
create awareness by way of research, education and
other promotional activities. What is much needed at
this time is the establishment of standards for the
conduct of risk assessment studies. To establish
standards we need reliable data which can be used to
develop appropriate guidelines for the purpose of
mitigation and adaptation programmes. IAQ can have
significant influence on health resulting in drop in
productivity and economy of a country. It has been
estimated that in the US, building related illnesses
(BRI) symptoms have a relationship with decrease (3 to
5%) in work performance in an affected population
resulting in an annual loss of US$60 billion in revenue.
However, based on efficient management programmes
they have also projected that the potential annual
savings can be in the region of US$10 to 30 billion. This
establishes that fact that good management programmes
based on efficient guidelines is of economic value to a
country and wellbeing of the population. The IMU has
embarked on a research programme to collect the
much-needed data for the framing of a good IAQ
guideline for Malaysia.
3.Synergistic antileukemic effect of phytoestrogens and chemotherapeutic drugs on leukemic cell lines in vitro.
Jing SHEN ; Wei-Jing ZHANG ; Yan-Chin TAI ; Ching-Ho Stephen WONG ; Zhigang XIE ; Chien-Shing CHEN
Journal of Experimental Hematology 2008;16(2):276-281
Natural phytoestrogens such as the isoflavones genistein and daidzein, and the flavones quercetin exhibit anti-cancer properties. This study was purpose to investigate the anti-proliferative effect of phytoestrogens on acute myeloid leukemia (AML) and chronic myeloid leukemia (CML) cells, and their synergistic antileukemic effect in combination with chemotherapeutic drugs. Optimal dosage of genistein, quercetin and in combination with chemicals for leukemia cells were determined by experiments. Cell viability, apoptosis induction and cell cycle arrest were detected by trypan blue staining, MTT assay, optical microscopy, flow cytometry (FCM). The schedule treatment of combination of genistein and chemicals was determined. The results showed that genistein exhibited a dose- and time-dependent inhibitory effect on cell proliferation in NB4 and HL-60 cells, induced apoptosis and cell cycle arrest in G2/M phase. Quercetin had evident inhibitory effect on the proliferation of K562 and K562/A cells. The combination of genistein and chemicals exerted a synergistic effect on cell growth inhibition. In conclusion, this study demonstrated the synergistic antileukemic effect of genistein with chemotherapeutic drugs on leukemic cells. This combination appears to be a new idea for the clinical novel treatment of leukemia.
Antineoplastic Agents
;
pharmacology
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Apoptosis
;
drug effects
;
Cell Proliferation
;
drug effects
;
Drug Synergism
;
Genistein
;
pharmacology
;
HL-60 Cells
;
Humans
;
Isoflavones
;
pharmacology
;
Leukemia, Monocytic, Acute
;
pathology
;
Leukemia, Myeloid, Acute
;
pathology
;
Phytoestrogens
;
pharmacology
;
Quercetin
;
pharmacology
4.Drug Discovery Insights from Medicinal Beetles in Traditional Chinese Medicine
Stephen T. DEYRUP ; Natalie C. STAGNITTI ; Mackenzie J. PERPETUA ; Siu Wah WONG-DEYRUP
Biomolecules & Therapeutics 2021;29(2):105-126
Traditional Chinese medicine (TCM) was the primary source of medical treatment for the people inhabiting East Asia for thousands of years. These ancient practices have incorporated a wide variety of materia medica including plants, animals and minerals. As modern sciences, including natural products chemistry, emerged, there became increasing efforts to explore the chemistry of this materia medica to find molecules responsible for their traditional use. Insects, including beetles have played an important role in TCM. In our survey of texts and review articles on TCM materia medica, we found 48 species of beetles from 34 genera in 14 different families that are used in TCM. This review covers the chemistry known from the beetles used in TCM, or in cases where a species used in these practices has not been chemically studied, we discuss the chemistry of closely related beetles. We also found several documented uses of beetles in Traditional Korean Medicine (TKM), and included them where appropriate. There are 129 chemical constituents of beetles discussed.
5.Parameters selection in gene selection using Gaussian kernel support vector machines by genetic algorithm.
Yong MAO ; Xiao-Bo ZHOU ; Dao-Ying PI ; You-Xian SUN ; Stephen T C WONG
Journal of Zhejiang University. Science. B 2005;6(10):961-973
In microarray-based cancer classification, gene selection is an important issue owing to the large number of variables and small number of samples as well as its non-linearity. It is difficult to get satisfying results by using conventional linear statistical methods. Recursive feature elimination based on support vector machine (SVM RFE) is an effective algorithm for gene selection and cancer classification, which are integrated into a consistent framework. In this paper, we propose a new method to select parameters of the aforementioned algorithm implemented with Gaussian kernel SVMs as better alternatives to the common practice of selecting the apparently best parameters by using a genetic algorithm to search for a couple of optimal parameter. Fast implementation issues for this method are also discussed for pragmatic reasons. The proposed method was tested on two representative hereditary breast cancer and acute leukaemia datasets. The experimental results indicate that the proposed method performs well in selecting genes and achieves high classification accuracies with these genes.
Algorithms
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Breast Neoplasms
;
genetics
;
Female
;
Genes
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Humans
;
Leukemia, Myeloid, Acute
;
genetics
;
Models, Genetic
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Oligonucleotide Array Sequence Analysis
;
methods
;
Predictive Value of Tests
6.The 2014 Hepatology Society of the Philippines consensus statements on the diagnosis and treatment of hepatitis C.
Wong Stephen N. ; Campos Jane R. ; Cua Ian Homer Y. ; Jamias Jade D. ; Labio Madalinee Eternity D. ; Tan Judy L. ; Ong Janus P. ; Salavaña Angela D. ; Go Arlinking O. ; Payawal Diana A
Philippine Journal of Internal Medicine 2015;53(1):1-14
Hepatitis C virus (HCV) infection is a devastating disease that is increasingly being diagnosed among Filipinos, especially in at-risk populations. There are disease-specific nuances in the evaluation and management of this infection. Furthermore, advances in the field brought about by clinical research are rapidly moulding the way we evaluate and manage HCV patients. Evidently, consensus statements formulated by experts in the field are needed in order to serve as a guide to physicians who see HCV patients in the clinic. With this in mind, the Hepatology Society of the Philippines spearheaded the formation of these statements which aimed to address issues in the diagnosis, evaluation, treatment, and follow-up care of patients with HCV infection.
Recommendations on the specific tests to perform in the evaluation of HCV patients before, during and after treatment, and first-line treatment of patients with acute and chronic HCV infection were provided. Treatment algorithms for chronic HCV infection, divided according to viral genotype, were also devised. We acknowledge the limitations brought about by the local inavailability of some drugs/treatment regimens in the local setting at the time of the formulation of these statements. As such, these statements will be revised as soon as new data become locally applicable.
Hepatitis C ; Diagnosis ; Infection ; Consensus ; Carcinoma, Hepatocellular ; Liver Cirrhosis
7.The 2014 Hepatology Society of the Philippines consensus statements on the management of chronic hepatitis B.
Jamias Jade D. ; Balce-Santos Dulcinea A. ; Bocobo Joseph C. ; Labio Madalinee Eternity D. ; Lontok Ma. Antoinette DC. ; Macatula Therese C. ; Ong Janus P. ; Ong-Go Arlinking K. ; Wong Stephen ; Yu Ira I. ; Payawal Diana A.
Philippine Journal of Internal Medicine 2015;53(1):17-33
Chorinic hepatitis B virus (CHB) infection is a serious problem that affects over 300 million people worldwide and is highly prevalent in the Asia Pacific region. In the Philippines an estimate 7.3 million Filipinos or 16.7% of adults are chronically infected with HBV, more than twice the average prevalence in the Western Pacific region.
In view of the above, the Hepatology Society of the Philippines (HSP) embarked on the development of consensus statements on the management of hepatitis B with the primary objectives of standardizing approach to management, empowering other physicians involved in the management of hepatitis B and advancing treatment subsidy by the Philippine Health Insurance Corporation (PhilHealth).
The local guidelines include screening and vaccination general management, indications for assessment of fibrosis in those who did not meet treatment criteria. indications for treatment, on-treatment and post-treatment monitoring and duration of antiviral treatment. Recommendations on the management of antiviral drug resistance, management of special populations including patients with concurrent HIV or hepatitis C infection, women of child-bearing age (pregnancy and breastfeeding), patients with decompensated liver disease, patients receiving immunosuppressive medications or chemotherapy and patients in the setting of hepatocellular carcinoma are also included. However, the guidelines did not include management for patients with liver and other solid organ transplantation, patients on renal replacement therapy, and children.
The consensus statements will be amended accordingly as new therapies become available.
Hepatitis B ; Consensus ; Hepatitis B, Chronic ; Hepatitis B Virus ; Fibrosis ; Drug Therapy ; Carcinoma, Hepatocellular ; Liver Cirrhosis ; Hepatitis Delta Virus ; Hiv
8.Chain length-dependent cooperativity in fatty acid binding and oxidation by cytochrome P450BM3 (CYP102A1).
Benjamin ROWLATT ; Jake A YORKE ; Anthony J STRONG ; Christopher J C WHITEHOUSE ; Stephen G BELL ; Luet-Lok WONG
Protein & Cell 2011;2(8):656-671
Fatty acid binding and oxidation kinetics for wild type P450(BM3) (CYP102A1) from Bacillus megaterium have been found to display chain length-dependent homotropic behavior. Laurate and 13-methyl-myristate display Michaelis-Menten behavior while there are slight deviations with myristate at low ionic strengths. Palmitate shows Michaelis-Menten kinetics and hyperbolic binding behavior in 100 mmol/L phosphate, pH 7.4, but sigmoidal kinetics (with an apparent intercept) in low ionic strength buffers and at physiological phosphate concentrations. In low ionic strength buffers both the heme domain and the full-length enzyme show complex palmitate binding behavior that indicates a minimum of four fatty acid binding sites, with high cooperativity for the binding of the fourth palmitate molecule, and the full-length enzyme showing tighter palmitate binding than the heme domain. The first flavin-to-heme electron transfer is faster for laurate, myristate and palmitate in 100 mmol/L phosphate than in 50 mmol/L Tris (pH 7.4), yet each substrate induces similar high-spin heme content. For palmitate in low phosphate buffer concentrations, the rate constant of the first electron transfer is much larger than k (cat). The results suggest that phosphate has a specific effect in promoting the first electron transfer step, and that P450(BM3) could modulate Bacillus membrane morphology and fluidity via palmitate oxidation in response to the external phosphate concentration.
Bacterial Proteins
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metabolism
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Cytochrome P-450 Enzyme System
;
metabolism
;
Fatty Acids
;
chemistry
;
metabolism
;
Lauric Acids
;
chemistry
;
metabolism
;
Myristic Acid
;
chemistry
;
metabolism
;
NADPH-Ferrihemoprotein Reductase
;
metabolism
;
Osmolar Concentration
;
Oxidation-Reduction
;
Palmitic Acid
;
chemistry
;
metabolism
;
Structure-Activity Relationship
10.Low sustainability of weight loss among patients with non-alcoholic fatty liver disease
Joseph Niñ ; o A ESPINO ; Ann Margaret C NAVARROZA ; Alvin Brian C VELASCO ; Rommel ROMANO ; Carmelita C DALUPANG ; Frederick T DY ; Stephen N WONG
Journal of Medicine University of Santo Tomas 2022;6(S1):126-133
Background:
Weight loss, though difficult to attain and sustain over time, remains the cornerstone of non-alcoholic fatty liver disease (NAFLD) treatment. We aimed to describe weight changes among NAFLD patients.
Methods:
This was a retrospective, cohort study of consecutively-identified NAFLD patients with >2 clinic visits from March2007–April2018. Weight changes from baseline were categorized into weight gain, weight loss, and no change. Baseline liver and metabolic biochemistries and non-invasive liver fibrosis tests were correlated with the final weight changes. Succeeding weight changes after the initial follow-up visits were used to determine sustainability of weight loss.
Results:
Of the 240 patients included, 123 (51.2%), 93 (38.8%), and 24 (10%) had weight gain, weight loss, and no change, respectively. Only 12.5% had >5% weight loss. Duration of follow-up was significantly longer for patients with weight loss (p<0.001). None of the baseline demographic and laboratory data were associated with weight loss. Patients with weight loss also did not have significant changes to their biochemistries and non-invasive liver fibrosis tests compared to patients with weight gain/no change. Compared to patients with weight gain after the initial follow-up, where only 11.8% were able to lose weight on the final visit, 73.1% of patients who lost weight after the initial follow-up were able to sustain their weight loss on the final visit.
Conclusions
Weight loss is achieved in only a third of NAFLD patients. Although 73% of patients who lost weight initially were able to sustain it, patients who gained weight after the 1st follow-up were unlikely to lose weight on further follow-up.
Non-alcoholic Fatty Liver Disease
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Weight Loss