Displaying publications 1 - 20 of 54 in total

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  1. Payungwong N, Sakdapipanich J, Wu J, Ho CC
    Polymers (Basel), 2023 Dec 07;15(24).
    PMID: 38139887 DOI: 10.3390/polym15244636
    Natural rubber (NR) latex derived from Hevea brasiliensis is a complex colloid comprising mainly rubber hydrocarbons (latex particles) and a multitude of minor non-rubber constituents such as non-rubber particles, proteins, lipids, carbohydrates, and soluble organic and inorganic substances. NR latex is susceptible to enzymatic attack after it leaves the trees. It is usually preserved with ammonia and, to a lesser extent, with other preservatives to enhance its colloidal stability during storage. Despite numerous studies in the literature on the influence of rubber proteins on NR latex stability, issues regarding the effect of protein hydrolysis in the presence of ammonia on latex stability during storage are still far from resolved. The present work aims to elucidate the interplay between protein hydrolysis and ammoniation in NR latex stability. Both high- and low-ammonia (with a secondary preservative) NR latexes were used to monitor the changes in their protein compositions during storage. High-ammonia (FNR-A) latex preserved with 0.6% (v/v) ammonia, a low 0.1% ammonia/TMTD/ZnO (FNR-TZ) latex, and a deproteinized NR (PDNR) latex were labeled with fluorescence agents and observed using confocal laser scanning microscopy to determine their protein composition. Protein hydrolysis was confirmed via sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The results revealed that protein hydrolysis increased with the storage duration. The change in protein composition accompanying hydrolysis also allows the spatial distribution of allergenic proteins to be estimated in the latex. Concurrently, the latex stability increased with the storage duration, as measured by the latex's mechanical stability time (MST) and the zeta potential of the latex particles. As monitored by AFM, the surface roughness of the NR latex film increased markedly during extended storage compared with that of the DPNR latex, which remained smooth. These results underscore the pivotal role of ammonia in bolstering NR latex stability brought on by protein hydrolysis, which greatly impacts latex film's formation behavior. NR latex stability underpins the quality of latex-dipped goods during manufacturing, particularly those for medical gloves.
  2. Rojruthai P, Sakdapipanich J, Wiriyanantawong J, Ho CC, Chaiear N
    Polymers (Basel), 2022 Nov 02;14(21).
    PMID: 36365670 DOI: 10.3390/polym14214679
    Natural rubber (NR) gloves manufactured from NR latex are widely utilized in various applications as a personal protective device due to their exceptional barrier characteristics in infection control. However, the use of NR gloves was associated with concerns on NR protein allergy. With comprehensive leaching procedures now a common practice in NR latex glove factories to eliminate latent rubber proteins and chemical allergens, occurrences and complaints of protein allergy from medical glove users have decreased drastically over the past two decades. The present work aims to eliminate further the residual rubber allergens in NR latex through effective purification of the NR latex and compounding the thus purified latex with an established formulation for allergy-free NR for glove applications. NR latex was purified by deproteinization and saponification, respectively. Several analytical techniques were used to verify rubber allergens eliminated in the purified latexes. Saponified NR (SPNR) latex was the purified NR latex of choice since it is devoid of allergenic proteins and poses the lowest risk of Type I allergy. The purified NR latex was compounded with zinc diethyldithiocarbamate (ZDEC), zinc dibutyldithiocarbamate (ZDBC), and zinc 2-mercaptobenzothiazole (ZMBT), respectively, for glove dipping. Among the investigated accelerators, only ZDBC was not detected in the artificial sweat that came into contact with the dipped articles. Thus, it is deduced that ZDBC poses the lowest risk of Type IV allergy to consumers. Additionally, the morphological and physical properties of dipped articles were assessed. It was revealed that the dipped film from the SPNR latex compounded with ZDBC provided thinner and less yellow products with a more uniform internal structure and a tensile strength comparable to those of commercial NR gloves.
  3. Ting CY, Ho CC, Yee HJ
    Big Data, 2020 12;8(6):519-527.
    PMID: 33347366 DOI: 10.1089/big.2020.0028
    Recommending a retail business given a particular location of interest is nontrivial. Such a recommendation process requires careful study of demographics, trade area characteristics, sales performance, traffic, and environmental features. It is not only human effort taxing but often introduces inconsistency due to subjectivity in expert opinions. The process becomes more challenging when no sales data can be used to make a recommendation. As an attempt to overcome the challenges, this study used the machine learning approach that utilizes similarity measures to perform the recommendation. However, two challenges required careful attention when using the machine learning approach: (1) how to prepare a feature set that can commonly represent different types of retail business and (2) which similarity measure approach produces optimal recommendation accuracy? The data sets used in this study consist of points of interest, population, property, job type, and education level. Empirical studies were conducted to investigate (1) the overall accuracy of proposed similarity measure approaches to the retail business recommendation, and (2) whether the proposed approaches have a bias toward certain retail categories. In summary, the findings suggested that the proposed similarity-based techniques elicited an accuracy of above 70% and demonstrated higher accuracy when the recommendation was made within a set of similar retail businesses.
  4. Kumarn S, Churinthorn N, Nimpaiboon A, Sriring M, Ho CC, Takahara A, et al.
    Langmuir, 2018 10 30;34(43):12730-12738.
    PMID: 30335388 DOI: 10.1021/acs.langmuir.8b02321
    The stabilization mechanism of natural rubber (NR) latex from Hevea brasiliensis was studied to investigate the components involved in base-catalyzed ester hydrolysis, namely, hydrolyzable lipids, ammonia, and the products responsible for the desired phenomenon observed in ammonia-preserved NR latex. Latex stability is generally thought to come from a rubber particle (RP) dispersion in the serum, which is encouraged by negatively charged species distributed on the RP surface. The mechanical stability time (MST) and zeta potential were measured to monitor field latices preserved in high (FNR-HA) and low ammonia (FNR-LA) contents as well as that with the ester-containing components removed (saponified NR) at different storage times. Amounts of carboxylates of free fatty acids (FFAs), which were released by the transformation and also hypothesized to be responsible for the like-charge repulsion of RPs, were measured as the higher fatty acid (HFA) number and corroborated by confocal laser scanning microscopy (CLSM) both qualitatively and quantitatively. The lipids and their FFA products interact differently with Nile red, which is a lipid-selective and polarity-sensitive fluorophore, and consequently re-emit characteristically. The results were confirmed by conventional ester content determination utilizing different solvent extraction systems to reveal that the lipids hydrolyzed to provide negatively charged fatty acid species were mainly the polar lipids (glycolipids and phospholipids) at the RP membrane but not those directly linked to the rubber molecule and, to a certain extent, those suspended in the serum. From new findings disclosed herein together with those already reported, a new model for the Hevea rubber particle in the latex form is proposed.
  5. Ting CY, Ho CC, Yee HJ, Matsah WR
    Big Data, 2018 03;6(1):42-52.
    PMID: 29570414 DOI: 10.1089/big.2017.0085
    Studies have shown that certain features from geography, demography, trade area, and environment can play a vital role in retail site selection, largely due to the impact they asserted on retail performance. Although the relevant features could be elicited by domain experts, determining the optimal feature set can be intractable and labor-intensive exercise. The challenges center around (1) how to determine features that are important to a particular retail business and (2) how to estimate retail sales performance given a new location? The challenges become apparent when the features vary across time. In this light, this study proposed a nonintervening approach by employing feature selection algorithms and subsequently sales prediction through similarity-based methods. The results of prediction were validated by domain experts. In this study, data sets from different sources were transformed and aggregated before an analytics data set that is ready for analysis purpose could be obtained. The data sets included data about feature location, population count, property type, education status, and monthly sales from 96 branches of a telecommunication company in Malaysia. The finding suggested that (1) optimal retail performance can only be achieved through fulfillment of specific location features together with the surrounding trade area characteristics and (2) similarity-based method can provide solution to retail sales prediction.
  6. Koh RY, Lim CL, Uhal BD, Abdullah M, Vidyadaran S, Ho CC, et al.
    Mol Med Rep, 2015 May;11(5):3808-13.
    PMID: 25585520 DOI: 10.3892/mmr.2015.3193
    Idiopathic pulmonary fibrosis is a chronic pulmonary disease that is characterized by formation of scar tissue in lungs. Transforming growth factor-β (TGF-β) is considered an important cytokine in the pathogenesis of this disease. Hence, the antifibrotic effect of an inhibitor of the TGF-β type I receptor, namely, SB 431542, was investigated in our study. SB 431542 was used to treat TGF-β-treated IMR-90 cells; the expression of α-smooth muscle actin (α-SMA) was detected at the protein level by using an anti-α-SMA antibody, and at the gene level by reverse transcription-quantitative PCR. The effect of the inhibitor on cell proliferation was determined by a cell growth assay. The inhibitor was also administered into bleomycin-treated mice. Histopathological assessment and determination of total collagen levels were carried out to evaluate the severity of lung fibrosis in these mice. Our results demonstrated that treatment with SB 431542 inhibits TGF-β‑induced α-SMA expression in lung fibroblasts, at both the protein and the mRNA levels (P<0.05). However, the inhibitor did not significantly reduce lung fibroblast proliferation. In the bleomycin-induced pulmonary fibrosis mouse model, bleomycin treatment caused important morphological changes, accompanied by an increase in the collagen level of the lungs. Early treatment with SB 431542 prevented the manifestation of histopathological alterations, whereas delayed treatment significantly decreased the collagen level (P<0.05). These results suggest that inhibition of TGF-β signaling, via inhibition of the activin receptor-like kinase-5 (ALK-5) by SB 431542, may attenuate pulmonary fibrosis.
  7. Teo CH, Ng CJ, Ho CC, Tan HM
    Public Health, 2015 Jan;129(1):60-7.
    PMID: 25542745 DOI: 10.1016/j.puhe.2014.11.009
    OBJECTIVE: There is currently no documentation on the availability and implementation of policies related to men's health in Asia. This Delphi study aimed to achieve an Asian consensus on men's health policy based on the opinions and recommendations from men's health key opinion leaders.
    STUDY DESIGN: A two-phase Delphi online survey was used to gather information from men's health stakeholders across Asian countries.
    METHODS: All stakeholders were invited to participate in the survey through men's health conferences, personal contacts, recommendations from international men's health organizations and snowballing method. Stakeholders were asked about their concerns on 17 men's health key issues as well as their opinion on the availability and recommendations on men's health policies and programmes in their countries.
    RESULTS: There were a total of 128 stakeholders (policy makers, clinicians, researchers and consumers), from 28 Asian countries, who responded in the survey. Up to 85% of stakeholders were concerned about various men's health issues in Asia and in their respective country, particularly in smoking, ischaemic heart disease and high blood pressure. There is a lack of men's health policies and programmes in Asia (availability = 11.6-43.5%) and up to 92.9% of stakeholders recommended that these should be developed.
    CONCLUSIONS: These findings call for policy change and development, and more importantly a concerted effort to elevate men's health status in Asia.
  8. Fam XI, Singam P, Ho CC, Sridharan R, Hod R, Bahadzor B, et al.
    Korean J Urol, 2015 Jan;56(1):63-7.
    PMID: 25598938 DOI: 10.4111/kju.2015.56.1.63
    Urinary calculi is a familiar disease. A well-known complication of endourological treatment for impacted ureteral stones is the formation of ureteral strictures, which has been reported to occur in 14.2% to 24% of cases.
  9. Tan HM, Tan WP, Wong JH, Ho CC, Teo CH, Ng CJ
    Korean J Urol, 2014 Nov;55(11):710-7.
    PMID: 25405012 DOI: 10.4111/kju.2014.55.11.710
    PURPOSE: The proposed Men's Health Index (MHI) aims to provide a practical and systematic framework for comprehensively assessing and stratifying older men with the intention of optimising their health and functional status.
    MATERIALS AND METHODS: A literature search was conducted using PubMed from 1980 to 2012. We specifically looked for instruments which: assess men's health, frailty and fitness; predict life expectancy, mortality and morbidities. The instruments were assessed by the researchers who then agreed on the tools to be included in the MHI. When there was disagreements, the researchers discussed and reached a consensus guided by the principle that the MHI could be used in the primary care setting targetting men aged 55-65 years.
    RESULTS: The instruments chosen include the Charlson's Combined Comorbidity-Age Index; the International Index of Erectile Function-5; the International Prostate Symptom Score; the Androgen Deficiency in Aging Male; the Survey of Health, Ageing and Retirement in Europe Frailty Instrument; the Sitting-Rising Test; the Senior Fitness Test; the Fitness Assessment Score; and the Depression Anxiety Stress Scale-21. A pilot test on eight men was carried out and showed that the men's health index is viable.
    CONCLUSIONS: The concept of assessing, stratifying, and optimizing men's health should be incorporated into routine health care, and this can be implemented by using the MHI. This index is particularly useful to primary care physicians who are in a strategic position to engage men at the peri-retirement age in a conversation about their life goals based on their current and predicted health status.
    KEYWORDS: Health status indicators; Men; Physical fitness; Retirement
  10. Ng CJ, Teo CH, Ho CC, Tan WP, Tan HM
    Prev Med, 2014 Oct;67:295-302.
    PMID: 25117523 DOI: 10.1016/j.ypmed.2014.08.007
    This study aims to compare health status and its risk factors between men and women who are from countries of different income status in Asia.
  11. Ho CC, Ngoo KS, Hamzaini AH, Rizal AM, Zulkifli MZ
    Clin Ter, 2014;165(2):75-81.
    PMID: 24770808 DOI: 10.7471/CT.2014.1680
    OBJECTIVE: To determine the clinical utility of urinary bladder and prostate characteristics measured by ultrasound scan in predicting acute urinary retention (AUR) for men with bladder outlet obstruction with an underlying benign prostate hyperplasia (BPH).
    MATERIALS AND METHODS: Consecutive men aged ≥50 years presenting with lower urinary tract symptoms (LUTS) or AUR were prospectively recruited in this cross-sectional study. International prostatic symptom score (IPSS) and serum prostate-specific antigen (PSA) were recorded. High-resolution ultrasound was used to measure bladder detrusor thickness (DT, mm), prostatic volume (PV, cm3), intravesical prostatic protrusion (IPP, mm), bladder wall thickness (BWT,mm), intravesical volume and bladder radius. The latter two parameters were used to estimate bladder weight (UEBW, g), assuming a spherical bladder.
    RESULTS: Among selected patients, thirty had AUR while 32 men presented with LUTS only. There were significant differences between those with and without AUR in their age (70.5 vs 66.0, p=0.017), IPSS (24.0 vs 18.5, p=0.009), serum PSA (6.18 vs 1.77, p=0.002), PV (56.7 vs 32.4, p=0.006), BWT (5.0 vs 4.4, p=0.034) and UEBW (39.1 vs 25.0, p=0.0003). Multivariate analysis revealed high IPSS and UEBW to be predictors for AUR. UEBW was the strongest predictor of AUR: area under ROC curve was 0.767, with sensitivity and specificity of 63.3% and 87.5%, respectively, at cut-off point of 35 g. The likelihood ratio for AUR was also best with UEBW≥35 g.
    CONCLUSIONS: Combined with IPSS, ultrasound determined bladder characteristic, particularly UEBW, is a useful tool in predicting AUR in men with BPH.
  12. Ho CC, Rusdi AR
    Clin Ter, 2014;165(2):107-9.
    PMID: 24770814 DOI: 10.7471/CT.2014.1686
    Scrotal tuberculosis (TB) is rare. Lack of awareness may lead to a misdiagnosis and/or delayed diagnosis of scrotal TB. Clinicians should have a high suspicion index for scrotal TB when facing a patient with a chronic scrotal lump. Since scrotal TB can be medically cured, biopsy of the scrotal lump for pathology study and/or urine polymerase chain reaction (PCR) analysis for M. tuberculosis should be performed first for rapid diagnostic purposes, and therefore unnecessary surgery may thereby be circumvented.
  13. Ho CC, Tan HM
    Aging Male, 2013 Sep;16(3):81-4.
    PMID: 23822757 DOI: 10.3109/13685538.2013.809414
    Men's health has gained prominence over the past few years but it is still not on par with the attention or funding that women and child health is getting. In Asia, this issue is even more conspicuous. With westernization of lifestyle, Asian men's problems emulate their Western counterparts but there are certain issues unique to Asian men due to cultural differences. This review will discuss the health issues affecting Asian men and suggest measures that can be taken to overcome them.
  14. Salem SA, Hwei NM, Bin Saim A, Ho CC, Sagap I, Singh R, et al.
    J Biomed Mater Res A, 2013 Aug;101(8):2237-47.
    PMID: 23349110 DOI: 10.1002/jbm.a.34518
    The chief obstacle for reconstructing the bladder is the absence of a biomaterial, either permanent or biodegradable, that will function as a suitable scaffold for the natural process of regeneration. In this study, polylactic-co-glycolic acid (PLGA) plus collagen or fibrin was evaluated for its suitability as a scaffold for urinary bladder construct. Human adipose-derived stem cells (HADSCs) were cultured, followed by incubation in smooth muscle cells differentiation media. Differentiated HADSCs were then seeded onto PLGA mesh supported with collagen or fibrin. Evaluation of cell-seeded PLGA composite immersed in culture medium was performed under a light and scanning microscope. To determine if the composite is compatible with the urodynamic properties of urinary bladder, porosity and leaking test was performed. The PLGA samples were subjected to tensile testing was pulled until PLGA fibers break. The results showed that the PLGA composite is biocompatible to differentiated HADSCs. PLGA-collagen mesh appeared to be optimal as a cell carrier while the three-layered PLGA-fibrin composite is better in relation to its leaking/ porosity property. A biomechanical test was also performed for three-layered PLGA with biological adhesive and three-layered PLGA alone. The tensile stress at failure was 30.82 ± 3.80 (MPa) and 34.36 ± 2.57 (MPa), respectively. Maximum tensile strain at failure was 19.42 ± 2.24 (mm) and 23.06 ± 2.47 (mm), respectively. Young's modulus was 0.035 ± 0.0083 and 0.043 ± 0.012, respectively. The maximum load at break was 58.55 ± 7.90 (N) and 65.29 ± 4.89 (N), respectively. In conclusion, PLGA-Fibrin fulfils the criteria as a scaffold for urinary bladder reconstruction.
  15. Ho CC, Ideris N
    Infection, 2013 Aug;41(4):893-6.
    PMID: 23471824 DOI: 10.1007/s15010-013-0443-x
    Parasite infestation of the testicular tunica and spermatic cord by filariae are rarely reported and may present with few clinical signs, depending upon the stage. Occasionally, it may mimic a testicular tumor. We present a case of a 29-year-old man who presented with left testicular swelling and discomfort for 4 months. Clinical examination and imaging suggested an intrascrotal cystic lesion with a normal left testis. However, the intraoperative findings revealed a tumor-like mass; hence, a left orchidectomy was performed. However, histopathology reported a diagnosis of a cystic testicular tunica and spermatic cord with parasite infection. Here, we review the literature of scrotal and testicular parasite disease and discuss the course of the appropriate management involved.
  16. Ho CC, Mun KS, Naidu R
    Malays J Pathol, 2013 Jun;35(1):33-43.
    PMID: 23817393 MyJurnal
    Breast cancer is the most common malignancy in women worldwide. The incidence of breast cancer in Malaysia is lower compared to international statistics, with peak occurrence in the age group between 50 to 59 years of age and mortality rates of 18.6%. Despite current diagnostic and prognostic methods, the outcome for individual subjects remain poor. This is in part due to breast cancers' wide genetic heterogeneity. Various platforms for genetics studies are now employed to determine the identity of these genetic abnormalities, including microarray methods like high density single-nucleotide-polymorphism (SNP) oligonucleotide arrays which combine the power of chromosomal comparative genomic hybridization (cCGH) and loss of heterozygosity (LOH) in the offering of higher-resolution mappings. These platforms and their applications in highlighting the genomic alteration frameworks manifested in breast carcinoma will be discussed.
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