MyMedR

Hemophagocytosis in dengue: comprehensive report of six cases

Tan LH, Lum LC, Omar SF, Kan FK

J Clin Virol, 2012 Sep;55(1):79-82.

PMID: 22789140 DOI: 10.1016/j.jcv.2012.06.005

Hemophagocytic syndrome is a potentially fatal disorder. It is being increasingly reported but remained under-recognized in dengue. Most reported cases were in association with plasma leakage and shock but multi-organ impairment was also observed. We describe the time-lines of 6 cases of confirmed dengue with varying severities of hemophagocytosis. All had persistent fever, cytopenia and elevated transaminases with markedly elevated ferritin levels during and beyond the plasma leakage phase. Acute renal failure and central nervous system manifestation were observed in two patients. Morphological hemophagocytosis was demonstrated in three patients. All survivors showed clinical and biochemical resolution of hemophagocytosis indicating its transient nature. Persistence of fever and cytopenia together with multi-organ dysfunction, out of proportion to and beyond the plasma leakage phase should prompt clinicians to consider this phenomenon.

Inhibitory effects of palm α-, γ- and δ-tocotrienol on lipopolysaccharide-induced nitric oxide production in BV2 microglia

Tan SW, Ramasamy R, Abdullah M, Vidyadaran S

Cell Immunol, 2011;271(2):205-9.

PMID: 21839427 DOI: 10.1016/j.cellimm.2011.07.012

Anti-inflammatory actions of the vitamin E fragment tocotrienol have not been described for microglia. Here, we screened palm α-, γ- and δ-tocotrienol isoforms and Tocomin® 50% (contains spectrum of tocotrienols and tocopherols) for their ability to limit nitric oxide (NO) production by BV2 microglia. Microglia were treated with varying doses of tocotrienols for 24h and stimulated with 1 μg/ml lipopolysaccharide (LPS). All tocotrienol isoforms reduced NO release by LPS-stimulated microglia, with 50 μM being the most potent tocotrienol dose. Of the isoforms tested, δ-tocotrienol lowered NO levels the most, reducing NO by approximately 50% at 48 h post-LPS treatment (p

Lumutinines A-D, linearly fused macroline-macroline and macroline-sarpagine bisindoles from Alstonia macrophylla

Lim SH, Tan SJ, Low YY, Kam TS

J Nat Prod, 2011 Dec 27;74(12):2556-62.

PMID: 22148233 DOI: 10.1021/np200730j

Four new linearly fused bisindole alkaloids, lumutinines A-D (1-4), were isolated from the stem-bark extract of Alstonia macrophylla. Lumutinines A (1) and B (2) represent the first examples of linear, ring A/F-fused macroline-macroline-type bisindoles, while lumutinines C (3) and D (4) were constituted from the union of macroline and sarpagine moieties. A reinvestigation of the stereochemical assignment of alstoumerine (8) by NMR and X-ray diffraction analyses indicated that the configuration at C-16 and C-19 required revision.

Rapid identification of cyclic tetrapyrrolic photosensitisers for photodynamic therapy using on-line hyphenated LC-PDA-MS coupled with photo-cytotoxicity assay

Tan PJ, Appleton DR, Mustafa MR, Lee HB

Phytochem Anal, 2012 Jan-Feb;23(1):52-9.

PMID: 21692117 DOI: 10.1002/pca.1324

Photodynamic therapy is a treatment modality that involves site-directed generation of cytotoxic reactive oxygen species by light-activated photosensitisers.

Fulltext Solubility of drugs in aqueous polymeric solution: effect of ovalbumin on microencapsulation process

Aziz HA, Tan YT, Peh KK

AAPS PharmSciTech, 2012 Mar;13(1):35-45.

PMID: 22101965 DOI: 10.1208/s12249-011-9707-x

Microencapsulation of water-soluble drugs using coacervation-phase separation method is very challenging, as these drugs partitioned into the aqueous polymeric solution, resulting in poor drug entrapment. For evaluating the effect of ovalbumin on the microencapsulation of drugs with different solubility, pseudoephedrine HCl, verapamil HCl, propranolol HCl, paracetamol, and curcuminoid were used. In addition, drug mixtures comprising of paracetamol and pseudoephedrine HCl were also studied. The morphology, encapsulation efficiency, particle size, and in vitro release profile were investigated. The results showed that the solubility of the drug determined the ratio of ovalbumin to be used for successful microencapsulation. The optimum ratios of drug, ovalbumin, and gelatin for water-soluble (pseudoephedrine HCl, verapamil HCl, and propranolol HCl), sparingly water-soluble (paracetamol), and water-insoluble (curcuminoid) drugs were found to be 1:1:2, 2:3:5, and 1:3:4. As for the drug mixture, the optimum ratio of drug, ovalbumin, and gelatin was 2:3:5. Encapsulated particles prepared at the optimum ratios showed high yield, drug loading, entrapment efficiency, and sustained release profiles. The solubility of drug affected the particle size of the encapsulated particle. Highly soluble drugs resulted in smaller particle size. In conclusion, addition of ovalbumin circumvented the partitioning effect, leading to the successful microencapsulation of water-soluble drugs.

Cytotoxic, apoptotic and anti-α-glucosidase activities of 3,4-di-O-caffeoyl quinic acid, an antioxidant isolated from the polyphenolic-rich extract of Elephantopus mollis Kunth

Ooi KL, Muhammad TS, Tan ML, Sulaiman SF

J Ethnopharmacol, 2011 Jun 1;135(3):685-95.

PMID: 21497647 DOI: 10.1016/j.jep.2011.04.001

The decoction of the whole plant of Elephantopus mollis Kunth. is traditionally consumed to treat various free radical-mediated diseases including cancer and diabetes.

Fulltext Oral nifedipine versus intravenous labetalol for acute blood pressure control in hypertensive emergencies of pregnancy: a randomised trial

Raheem IA, Saaid R, Omar SZ, Tan PC

BJOG, 2012 Jan;119(1):78-85.

PMID: 21985500 DOI: 10.1111/j.1471-0528.2011.03151.x

To compare oral nifedipine with intravenous labetalol in their rapidity to control hypertensive emergencies of pregnancy.

Fulltext Ethnic disparities in metabolic syndrome in Malaysia: an analysis by risk factors

Tan AKG, Dunn RA, Yen ST

Metab Syndr Relat Disord, 2011 Dec;9(6):441-51.

PMID: 21815810 DOI: 10.1089/met.2011.0031

BACKGROUND: This study investigates ethnic disparities in metabolic syndrome in Malaysia.
METHODS: Data were obtained from the Malaysia Non-Communicable Disease Surveillance-1 (2005/2006). Logistic regressions of metabolic syndrome health risks on sociodemographic and health-lifestyle factors were conducted using a multiracial (Malay, Chinese, and Indian and other ethnic groups) sample of 2,366 individuals.
RESULTS: Among both males and females, the prevalence of metabolic syndrome amongst Indians was larger compared to both Malays and Chinese because Indians are more likely to exhibit central obesity, elevated fasting blood glucose, and low high-density lipoprotein cholesterol. We also found that Indians tend to engage in less physical activity and consume fewer fruits and vegetables than Malays and Chinese. Although education and family history of chronic disease are associated with metabolic syndrome status, differences in socioeconomic attributes do not explain ethnic disparities in metabolic syndrome incidence. The difference in metabolic syndrome prevalence between Chinese and Malays was not statistically significant. Whereas both groups exhibited similar obesity rates, ethnic Chinese were less likely to suffer from high fasting blood glucose.
CONCLUSIONS: Metabolic syndrome disproportionately affects Indians in Malaysia. Additionally, fasting blood glucose rates differ dramatically amongst ethnic groups. Attempts to decrease health disparities among ethnic groups in Malaysia will require greater attention to improving the metabolic health of Malays, especially Indians, by encouraging healthful lifestyle changes.
Study name: Malaysia Non-Communicable Disease Surveillance-1 (MyNCDS-1) survey

TT genotype of the methylenetetrahydrofolate reductase C677T polymorphism is an important determinant for homocysteine levels in multi-ethnic Malaysian ischaemic stroke patients

Mejia Mohamed EH, Tan KS, Ali JM, Mohamed Z

Ann Acad Med Singap, 2011 Apr;40(4):186-91.

PMID: 21678004

INTRODUCTION: The functional point mutation C677T in the methylenetetrahydrofolate reductase (MTHFR) gene, has been reported to contribute to hyperhomocysteinaemia which is a risk factor for atherothrombotic ischaemic strokes. This study evaluated the prevalence of the C677T polymorphism of the gene in Malaysian ischaemic stroke subjects of Malay, Chinese and Indian ethnicities, and its association with homocysteine levels (tHcy).

MATERIALS AND METHODS: A total of 292 subjects were recruited, comprising 150 ischaemic stroke patients and 142 control subjects who were age and sex matched. Plasma homocysteine, serum folate and vitamin B12 were measured in all subjects. Genotyping was carried out using PCR-RFLP.

RESULTS: The homocysteine levels were significantly higher (P = 0.001) in the stroke group (11.35 ± 2.75 μmol/L) compared to the control group (10.38 ± 2.79 μmol/L). The MTHFR C677T genotype distribution for the stroke group was 46%, 40% and 14%, respectively for CC, CT and TT genotypes and 59.9%, 33.8% and 6.3%, respectively for the control group. The genotype and allelic frequencies were significantly different between the 2 groups, with P = 0.02 and P = 0.004 respectively. No significant difference was seen in the genotype distribution inter-ethnically. An increasing tHcy was seen with every additional T allele, and the differences in the tHcy for the different genotypes were significant in both the control (P <0.001) and stroke groups (P <0.001).

CONCLUSION: This study shows that TT genotype of the methylenetetrahydrofolate reductase C677T polymorphic gene is an important determinant for homocysteine levels in Malaysian ischaemic stroke patients.

Fulltext Public perceptions and attitudes toward thalassaemia: Influencing factors in a multi-racial population

Wong LP, George E, Tan JA

BMC Public Health, 2011;11:193.

PMID: 21447191 DOI: 10.1186/1471-2458-11-193

Thalassaemia is a common public health problem in Malaysia and about 4.5 to 6% of the Malays and Chinese are carriers of this genetic disorder. The major forms of thalassaemia result in death in utero of affected foetuses (α-thalassaemia) or life-long blood transfusions for survival in β-thalassaemia. This study, the first nationwide population based survey of thalassaemia in Malaysia, aimed to determine differences in public awareness, perceptions and attitudes toward thalassaemia in the multi-racial population in Malaysia.

Men's health: sexual dysfunction, physical, and psychological health--is there a link?

Tan HM, Tong SF, Ho CC

J Sex Med, 2012 Mar;9(3):663-71.

PMID: 22188573 DOI: 10.1111/j.1743-6109.2011.02582.x

INTRODUCTION: Sexual dysfunction in men, such as erectile dysfunction, hypogonadism, and premature ejaculation, generates considerable attention. Its association with physical and psychological health is an issue which should be addressed seriously.
AIM: A review of the literature pertaining to the correlation between sexual dysfunction and physical and psychological health.
METHODS: PubMed search for relevant publications on the association between sexual dysfunction in men and physical and psychological health.
MAIN OUTCOME MEASURE: Clinical and epidemiological evidence that demonstrates the association between sexual dysfunction in men and physical and psychological health.
RESULTS: Sexual dysfunction, i.e., erectile dysfunction, hypogonadism, and premature ejaculation, has been shown to be associated with physical and psychological health. There is a strong correlation between sexual dysfunction and cardiovascular disease, metabolic syndrome, quality of life, and depression.
CONCLUSION: The association between men's sexual dysfunction and physical and psychological health is real and proven. Therefore, it should not be taken lightly but instead treated as a life-threatening medical problem.

Display of the antigenic region of Nipah virus nucleocapsid protein on hepatitis B virus capsid

Yap WB, Tey BT, Alitheen NB, Tan WS

J Biosci Bioeng, 2012 Jan;113(1):26-9.

PMID: 22024533 DOI: 10.1016/j.jbiosc.2011.09.007

The C-terminal domain of Nipah virus (NiV) nucleocapsid protein (NP₄₀₁₋₅₃₂) was inserted at the N-terminus and the immunodominant loop of hepatitis B core antigen (HBc). The stability of NP₄₀₁₋₅₃₂ increased tremendously when displayed on the HBc particles. These particles reacted specifically with the swine anti-NiV and the human anti-HBc antisera.

Herbal delivery system for treatment of obesity administration of encapsulated khat-extracts on body weight of rats

Aziz HA, Peh KK, Tan YT

Obes Res Clin Pract, 2011 Oct-Dec;5(4):e267-360.

PMID: 24331133 DOI: 10.1016/j.orcp.2011.03.008

Obesity is one of the most important problems worldwide. Khat (Catha edulis), an evergreen shrub, is thought to reduce body-weight. Its effect is more prominent when khat leaves are chewed. Thus, anti-obesity effects of khat and its associated side effects may depend on the release rate of its active constituents. The present study aimed to investigate the effect of a selected low dose of dried-khat, extracted, formulated as controlled release delivery systems on the body weight (BW), food intake (FI), cholesterol (CS) and triglyceride (TG) levels in rats. Khat extract (KE) was microencapsulated (KE235) and formulated into a parenteral implant (InjKE235). The effects of KE, KE235 and InjKE235 on BW, FI, CS and TG in rats were investigated. The results showed that microcapsules sustained the khat alkaloid release with T50% 1.58 h for KE235 and 14.41 days for InjKE235. KE and KE235 caused maximum reduction in BW, FI, CS and TG during the first to third weeks but rebound gradually thereafter. On the contrary, InjKE235 exhibited a sustained reduction in BW, FI, CS and TG levels for 2 months. The T50% of KE, KE235 and InjKE235 correlated with the reduction in BW, CS and TG but not with FI. In conclusion, the subcutaneous injection and sustained release rate of khat extract play an important role in enhancing the anti-obesity effect in SD rats.:

Single dose 17 alpha-hydroxyprogesterone caproate in preterm labor: a randomized trial

Tan PC, King AS, Vallikkannu N, Omar SZ

Arch Gynecol Obstet, 2012 Mar;285(3):585-90.

PMID: 21796421 DOI: 10.1007/s00404-011-2026-3

To evaluate the effect of a single 250-mg dose of 17 alpha-hydroxyprogesterone caproate (17-OHPC) intramuscularly as adjunct to nifedipine tocolysis in preterm labor.

Fulltext You look familiar: how Malaysian Chinese recognize faces

Tan CB, Stephen ID, Whitehead R, Sheppard E

PLoS One, 2012;7(1):e29714.

PMID: 22253762 DOI: 10.1371/journal.pone.0029714

East Asian and white Western observers employ different eye movement strategies for a variety of visual processing tasks, including face processing. Recent eye tracking studies on face recognition found that East Asians tend to integrate information holistically by focusing on the nose while white Westerners perceive faces featurally by moving between the eyes and mouth. The current study examines the eye movement strategy that Malaysian Chinese participants employ when recognizing East Asian, white Western, and African faces. Rather than adopting the Eastern or Western fixation pattern, Malaysian Chinese participants use a mixed strategy by focusing on the eyes and nose more than the mouth. The combination of Eastern and Western strategies proved advantageous in participants' ability to recognize East Asian and white Western faces, suggesting that individuals learn to use fixation patterns that are optimized for recognizing the faces with which they are more familiar.

Lack of increased P15INK4B protein expression in basal cell carcinomas

Moad AI, Tan ML, Kaur G, Mabruk M

Asian Pac J Cancer Prev, 2012;13(12):6239-44.

PMID: 23464438

BACKGROUND: The basal cell carcinoma (BCC) is the most common non-melanoma skin cancer (NMSK). BCC might develop because of the faulty cell cycle arrest. P15INK4b is a tumor suppressor gene, involved in cell cycle arrest and inactivated in most human cancers. The role of p15INK4b protein expression in the genesis of BCC is as yet unknown. In a previous study we showed the absence of p15INK4b expression in the majority of tissue microarray cores of cutaneous squamous cell carcinoma (SCCs), another type of non-melanoma skin cancer, indicating that p15INK4b could possibly be involved in the pathogenesis of cutaneous SCC. The aim of this study was to investigate p15INK4b protein expression in BCCs.

MATERIALS AND METHOD: Protein expression of p15INK4b in 35 cases of BCC tissue arrays and 19 cases of normal human skin tissue was studied using an immunohistochemical approach.

RESULTS: The expression of p15INK4b was not significantly different in the BCC cases as compared with normal human skin (p=0.356; p>0.05). In addition, there were no significant relationship between clinicopathologic variables of patients (age and sex) and p15INK4b protein expression.

CONCLUSIONS: Our finding may indicate that p15INK4b protein expression does not play a role in the genesis of BCC.

Bitten by the "flying" tree snake, Chrysopelea paradisi

Tan TL, Ismail AK, Kong KW, Ahmad NK

J Emerg Med, 2012 Apr;42(4):420-3.

PMID: 22154775 DOI: 10.1016/j.jemermed.2011.03.038

The paradise tree snake, Chrysopelea paradisi, is a rear-fanged colubrid. Like other members of the genus Chrysopelea, it is able to glide through the air, and thus, is commonly known as a "flying snake." There are few documented effects of its bite on humans.

Fulltext Delivery of chimeric hepatitis B core particles into liver cells

Lee KW, Tey BT, Ho KL, Tan WS

J Appl Microbiol, 2012 Jan;112(1):119-31.

PMID: 21992228 DOI: 10.1111/j.1365-2672.2011.05176.x

To display a liver-specific ligand on the hepatitis B virus core particles for cell-targeting delivery.

A comparison of radiometric correction techniques in the evaluation of the relationship between LST and NDVI in Landsat imagery

Tan KC, Lim HS, Matjafri MZ, Abdullah K

Environ Monit Assess, 2012 Jun;184(6):3813-29.

PMID: 21755424 DOI: 10.1007/s10661-011-2226-0

Atmospheric corrections for multi-temporal optical satellite images are necessary, especially in change detection analyses, such as normalized difference vegetation index (NDVI) rationing. Abrupt change detection analysis using remote-sensing techniques requires radiometric congruity and atmospheric correction to monitor terrestrial surfaces over time. Two atmospheric correction methods were used for this study: relative radiometric normalization and the simplified method for atmospheric correction (SMAC) in the solar spectrum. A multi-temporal data set consisting of two sets of Landsat images from the period between 1991 and 2002 of Penang Island, Malaysia, was used to compare NDVI maps, which were generated using the proposed atmospheric correction methods. Land surface temperature (LST) was retrieved using ATCOR3_T in PCI Geomatica 10.1 image processing software. Linear regression analysis was utilized to analyze the relationship between NDVI and LST. This study reveals that both of the proposed atmospheric correction methods yielded high accuracy through examination of the linear correlation coefficients. To check for the accuracy of the equation obtained through linear regression analysis for every single satellite image, 20 points were randomly chosen. The results showed that the SMAC method yielded a constant value (in terms of error) to predict the NDVI value from linear regression analysis-derived equation. The errors (average) from both proposed atmospheric correction methods were less than 10%.

Fulltext Neuroprotective effects of alpha lipoic Acid on haloperidol-induced oxidative stress in the rat brain

Perera J, Tan JH, Jeevathayaparan S, Chakravarthi S, Haleagrahara N

Cell Biosci, 2011;1(1):12.

PMID: 21711768 DOI: 10.1186/2045-3701-1-12

Haloperidol is an antipsychotic drug that exerts its' antipsychotic effects by inhibiting dopaminergic neurons. Although the exact pathophysiology of haloperidol extrapyramidal symptoms are not known, the role of reactive oxygen species in inducing oxidative stress has been proposed as one of the mechanisms of prolonged haloperidol-induced neurotoxicity. In the present study, we evaluate the protective effect of alpha lipoic acid against haloperidol-induced oxidative stress in the rat brain. Sprague Dawley rats were divided into control, alpha lipoic acid alone (100 mg/kg p.o for 21 days), haloperidol alone (2 mg/kg i.p for 21 days), and haloperidol with alpha lipoic acid groups (for 21 days). Haloperidol treatment significantly decreased levels of the brain antioxidant enzymes super oxide dismutase and glutathione peroxidase and concurrent treatment with alpha lipoic acid significantly reversed the oxidative effects of haloperidol. Histopathological changes revealed significant haloperidol-induced damage in the cerebral cortex, internal capsule, and substantia nigra. Alpha lipoic acid significantly reduced this damage and there were very little neuronal atrophy. Areas of angiogenesis were also seen in the alpha lipoic acid-treated group. In conclusion, the study proves that alpha lipoic acid treatment significantly reduces haloperidol-induced neuronal damage.

Displaying publications 2001 - 2020 of 8049 in total