Displaying publications 21 - 40 of 101 in total

Abstract:
Sort:
  1. Lee SH, Jaganath IB, Manikam R, Sekaran SD
    BMC Complement Altern Med, 2013 Oct 20;13:271.
    PMID: 24138815 DOI: 10.1186/1472-6882-13-271
    BACKGROUND: Lung cancer constitutes one of the malignancies with the greatest incidence and mortality rates with 1.6 million new cases and 1.4 million deaths each year. Prognosis remains poor due to deleterious development of multidrug resistance resulting in less than 15% lung cancer patients reaching five years survival. We have previously shown that Phyllanthus induced apoptosis in conjunction with its antimetastastic action. In the current study, we aimed to determine the signaling pathways utilized by Phyllanthus to exert its antimetastatic activities.

    METHODS: Cancer 10-pathway reporter array was performed to screen the pathways affected by Phyllanthus in lung carcinoma cell line (A549) to exert its antimetastatic effects. Results from this array were then confirmed with western blotting, cell cycle analysis, zymography technique, and cell based ELISA assay for human total iNOS. Two-dimensional gel electrophoresis was subsequently carried out to study the differential protein expressions in A549 after treatment with Phyllanthus.

    RESULTS: Phyllanthus was observed to cause antimetastatic activities by inhibiting ERK1/2 pathway via suppression of Raf protein. Inhibition of this pathway resulted in the suppression of MMP2, MMP7, and MMP9 expression to stop A549 metastasis. Phyllanthus also inhibits hypoxia pathway via inhibition of HIF-1α that led to reduced VEGF and iNOS expressions. Proteomic analysis revealed a number of proteins downregulated by Phyllanthus that were involved in metastatic processes, including invasion and mobility proteins (cytoskeletal proteins), transcriptional proteins (proliferating cell nuclear antigen; zinc finger protein), antiapoptotic protein (Bcl2) and various glycolytic enzymes. Among the four Phyllanthus species tested, P. urinaria showed the greatest antimetastatic activity.

    CONCLUSIONS: Phyllanthus inhibits A549 metastasis by suppressing ERK1/2 and hypoxia pathways that led to suppression of various critical proteins for A549 invasion and migration.

  2. Lee SH, Jaganath IB, Wang SM, Sekaran SD
    PLoS One, 2011;6(6):e20994.
    PMID: 21698198 DOI: 10.1371/journal.pone.0020994
    Current chemotherapeutic drugs kill cancer cells mainly by inducing apoptosis. However, they become ineffective once cancer cell has the ability to metastasize, hence the poor prognosis and high mortality rate. Therefore, the purpose of this study was to evaluate the antimetastatic potential of Phyllanthus (P. niruri, P. urinaria, P. watsonii, and P. amarus) on lung and breast carcinoma cells.
  3. Shekhar KC, Nazarina AR, Lee SH, Pathmanathan R
    Med J Malaysia, 1995 Jun;50(2):182-6.
    PMID: 7565193
    Clonorchiasis and opisthorchiasis are snail-transmitted trematode infections. The disease is endemic in many parts of Asia. Local case reports have been predominantly in Chinese with a history of travel to endemic countries. Thus far, 20 cases of liver fluke infestation have been reported in this country. This report presents another two cases of clonorchiasis and a case of opisthorchiasis. We also briefly review pertinent aspects of the disease.
  4. Tan LP, Choong SS, Samsuddin AS, Lee SH
    Ticks Tick Borne Dis, 2019 10;10(6):101285.
    PMID: 31494069 DOI: 10.1016/j.ttbdis.2019.101285
    Two ticks were collected from a reticulated python (Malayopython reticulatus) caught in Tumpat District, Kelantan, Peninsular Malaysia. The ticks were first identified as Ambylomma sp. through morphological comparison with identification keys. Determination of the tick species was made through PCR and sequencing. However, BLAST analysis revealed 85-88% sequence nucleotide identity with Amblyomma nitidum and Amblyomma geoemydae. Additionally, the morphological features of the ticks collected in this study did not match either A. nitidum or A. geoemydae. Further examination of the ticks confirmed the species as Amblyomma cordiferum. This is the first record of A. cordiferum DNA sequence with morphological support of colour illustrations for adult A. cordiferum. This is also the most recent record of this host association in Peninsular Malaysia. Information from this report can serve as a reference for species identification using the described morphology or molecular sequences.
  5. Lee SH, Reed-Newman T, Anant S, Ramasamy TS
    Stem Cell Rev Rep, 2020 12;16(6):1185-1207.
    PMID: 32894403 DOI: 10.1007/s12015-020-10031-8
    Quiescence in cancer cells is considered a therapeutic challenge as it confers dormancy in tumour, hence circumventing inherent anti-neoplastic surveillance system and standard-of-care cancer therapeutics including chemotherapy and radiotherapy. Since majority of the therapeutics target actively proliferating cancer cells, cancer cells eventually develop quiescent nature as mechanism of survival and cancer progression under both niche and therapeutic pressures. Quiescence state in cancer cells, eventually, confers resistant and aggressive nature to conventional cancer therapies, resulting in disease progression and relapse. Therefore, targeting quiescent cancer cells or cancer stem cells is a promising therapeutic approach, however an extensive review of the relevant information is needed in order to device an effective therapy. While the evidence of quiescence regulation in CSCs is rather a complex molecular and cellular network, herein, we aim to provide a comprehensive understanding of both intrinsic and extrinsic regulation in association with the function of CSCs. Findings on induction of quiescent state in CSCs population, its regulation at both cellular and molecular level, key molecular regulators, cellular events and processes including potential targets to develop therapeutics are extensively reviewed. This review also highlights the impact of CSC plasticity on quiescence which capturing the key challenge of targeting the cells in this state. Beyond understanding the mechanisms underlying quiescence nature of cancer cells, this review provides insightful perspective and future direction on insight in targeting these populations, hence collapse the tumour dormancy programme in order to eradicate tumour mass as a whole. Capability of CSCs to establish quiescent state as a mechanism of survival during unfavorable conditions, as well as its impact in cancer progression and subsequent relapse, including the potential therapeutic strategy to eradicate this CSCs sub-population in the tumor mass as an effective cancer therapy.
  6. Lee SH, Lee OS, Teo SH, Lee YS
    Gait Posture, 2017 09;57:57-68.
    PMID: 28577508 DOI: 10.1016/j.gaitpost.2017.05.023
    We conducted a meta-analysis to analyze how high tibial osteotomy (HTO) changes gait and focused on the following questions: (1) How does HTO change basic gait variables? (2) How does HTO change the gait variables in the knee joint? Twelve articles were included in the final analysis. A total of 383 knees was evaluated. There were 237 open wedge (OW) and 143 closed wedge (CW) HTOs. There were 4 level II studies and 8 level III studies. All studies included gait analysis and compared pre- and postoperative values. One study compared CWHTO and unicompartmental knee arthroplasty (UKA), and another study compared CWHTO and OWHTO. Five studies compared gait variables with those of healthy controls. One study compared operated limb gait variables with those in the non-operated limb. Gait speed, stride length, knee adduction moment, and lateral thrust were major variables assessed in 2 or more studies. Walking speed increased and stride length was increased or similar after HTO compared to the preoperative value in basic gait variables. Knee adduction moment and lateral thrust were decreased after HTO compared to the preoperative knee joint gait variables. Change in co-contraction of the medial side muscle after surgery differed depending on the degree of frontal plane alignment. The relationship between change in knee adduction moment and change in mechanical axis angle was controversial. Based on our systematic review and meta-analysis, walking speed and stride length increased after HTO. Knee adduction moment and lateral thrust decreased after HTO compared to the preoperative values of gait variables in the knee joint.
  7. Lee YS, Lee SH, Lee ES, Fong TS
    BMC Musculoskelet Disord, 2019 Mar 20;20(1):118.
    PMID: 30894158 DOI: 10.1186/s12891-019-2505-4
    BACKGROUND: We report a case of hardware failure after distal femoral osteotomy (DFO) with a broken screw pulled out from the locking hole and positioned within the knee joint.

    CASE PRESENTATION: A 57-year-old man presented to our orthopedic outpatient department with 3-months history of an unusual painful swelling at the operated area following DFO. The leakage of joint fluid from the penetrated suprapatellar pouch was assumed to be the reason for this complication.

    CONCLUSIONS: The overall aim of this case report is to provide a lesson to budding surgeons who might experience a similar situation that cannot be easily explained, like the unexpected complication in the present case.

  8. Lee YS, Lee OS, Lee SH, Hui TS
    Arthroscopy, 2018 02;34(2):592-602.
    PMID: 28974333 DOI: 10.1016/j.arthro.2017.07.023
    PURPOSE: The purpose of this systematic review and meta-analysis was to evaluate the effect of the timing of anterior cruciate ligament (ACL) reconstruction on clinical and stability outcomes by analyzing high-quality studies that assessed timing as a primary objective.

    METHODS: The MEDLINE, EMBASE, and Cochrane database were systematically searched. The inclusion criteria were as follows: (1) English articles, (2) noncomparative study or relevant study reporting clinical and/or stability results, and (3) timing of the ACL reconstruction as a primary objective. Study type, level of evidence, randomization method, exclusion criteria, number of cases, age, sex, timing of ACL reconstruction, follow-up, clinical outcomes, stability outcomes, and other relevant findings were recorded. Statistical analysis of the Lysholm scores and KT-1000 arthrometer measurements after early and delayed ACL reconstruction was performed using R version 3.3.1.

    RESULTS: Seven articles were included in the final analysis. There were 6 randomized controlled trials and 1 Level II study. Pooled analysis was performed using only Level I studies. All studies assessed the timing of ACL reconstruction as a primary objective. The definition of early ranged broadly from 9 days to 5 months and delayed ranged from 10 weeks to >24 months, and there was an overlap of the time intervals between some studies. The standard timing of the delayed reconstruction was around 10 weeks from injury in the pooled analysis. After pooling of data, clinical result was not statistically different between groups (I2: 47%, moderate level of heterogeneity). No statistically significant difference was observed in the KT-1000 arthrometer measurements between groups (I2: 76.2%, high level of heterogeneity) either.

    CONCLUSION: This systematic review and meta-analysis performed using currently available high-quality literature provides relatively strong evidence that early ACL reconstruction results in good clinical and stability outcomes. Early ACL reconstruction results in comparable clinical and stability outcomes compared with delayed ACL reconstruction.

    LEVEL OF EVIDENCE: Level II, a systematic review and meta-analysis of Level I and II studies.

  9. Wong KT, Koh KB, Lee SH, Chee CP
    Singapore Med J, 1996 Aug;37(4):441-2.
    PMID: 8993152
    Primary germinomas of the central nervous system carry a good prognosis because of their radiosensitivity. Recurrences are rare and extraneural metastases are even more unusual. One of the possible routes of extraneural spread is via ventriculo-peritoneal shunts which may be required to reduce intracranial pressure. One such case of germinoma metastasizing via a ventriculo-peritoneal shunt is reported. Patients with intracranial germinomas and ventriculo-peritoneal shunts should have close surveillance of their abdomens and may require systemic chemotherapy.
  10. Lee SH, Ng CX, Wong SR, Chong PP
    Curr Drug Targets, 2023;24(6):484-508.
    PMID: 36999414 DOI: 10.2174/1389450124666230329123409
    MicroRNAs have a plethora of roles in various biological processes in the cells and most human cancers have been shown to be associated with dysregulation of the expression of miRNA genes. MiRNA biogenesis involves two alternative pathways, the canonical pathway which requires the successful cooperation of various proteins forming the miRNA-inducing silencing complex (miRISC), and the non-canonical pathway, such as the mirtrons, simtrons, or agotrons pathway, which bypasses and deviates from specific steps in the canonical pathway. Mature miRNAs are secreted from cells and circulated in the body bound to argonaute 2 (AGO2) and miRISC or transported in vesicles. These miRNAs may regulate their downstream target genes via positive or negative regulation through different molecular mechanisms. This review focuses on the role and mechanisms of miRNAs in different stages of breast cancer progression, including breast cancer stem cell formation, breast cancer initiation, invasion, and metastasis as well as angiogenesis. The design, chemical modifications, and therapeutic applications of synthetic anti-sense miRNA oligonucleotides and RNA mimics are also discussed in detail. The strategies for systemic delivery and local targeted delivery of the antisense miRNAs encompass the use of polymeric and liposomal nanoparticles, inorganic nanoparticles, extracellular vesicles, as well as viral vectors and viruslike particles (VLPs). Although several miRNAs have been identified as good candidates for the design of antisense and other synthetic modified oligonucleotides in targeting breast cancer, further efforts are still needed to study the most optimal delivery method in order to drive the research beyond preclinical studies.
  11. Lee SH, H'ng PS, Peng TL, Lum WC
    Pak J Biol Sci, 2013 Nov 01;16(21):1415-8.
    PMID: 24511759
    The objective of this study is to investigate the feasibility of formaldehyde catcher as termites repellent. Single-layered UF-bonded particleboard was post-treated with formaldehyde catcher and heat respectively. Besides that, some boards were also produced with the formaldehyde catcher was added into the resin during the blending process, called add-in method. Particleboard post-treated with formaldehyde catcher reported the most severe attack. Heat-treated particleboard showed slightly better durability than the control blocks while the add-in catcher showed the best durability among three methods. A valid test was obtained as the termites survived the first week of the test. However, all the termites were found dead at the end of the test.
  12. Ooi SK, Lim TY, Lee SH, Nathan S
    Virulence, 2012 Oct 01;3(6):485-96.
    PMID: 23076282 DOI: 10.4161/viru.21808
    The nematode Caenorhabditis elegans is hypersusceptible to Burkholderia pseudomallei infection. However, the virulence mechanisms underlying rapid lethality of C. elegans upon B. pseudomallei infection remain poorly defined. To probe the host-pathogen interaction, we constructed GFP-tagged B. pseudomallei and followed bacterial accumulation within the C. elegans intestinal lumen. Contrary to slow-killing by most bacterial pathogens, B. pseudomallei caused fairly limited intestinal lumen colonization throughout the period of observation. Using grinder-defective mutant worms that allow the entry of intact bacteria also did not result in full intestinal lumen colonization. In addition, we observed a significant decline in C. elegans defecation and pharyngeal pumping rates upon B. pseudomallei infection. The decline in defecation rates ruled out the contribution of defecation to the limited B. pseudomallei colonization. We also demonstrated that the limited intestinal lumen colonization was not attributed to slowed host feeding as bacterial loads did not change significantly when feeding was stimulated by exogenous serotonin. Both these observations confirm that B. pseudomallei is a poor colonizer of the C. elegans intestine. To explore the possibility of toxin-mediated killing, we examined the transcription of the C. elegans ABC transporter gene, pgp-5, upon B. pseudomallei infection of the ppgp-5::gfp reporter strain. Expression of pgp-5 was highly induced, notably in the pharynx and intestine, compared with Escherichia coli-fed worms, suggesting that the host actively thwarted the pathogenic assaults during infection. Collectively, our findings propose that B. pseudomallei specifically and continuously secretes toxins to overcome C. elegans immune responses.
  13. Lee SH, Ooi SK, Mahadi NM, Tan MW, Nathan S
    PLoS One, 2011;6(3):e16707.
    PMID: 21408228 DOI: 10.1371/journal.pone.0016707
    Burkholderia pseudomallei is the causative agent of melioidosis, a disease of significant morbidity and mortality in both human and animals in endemic areas. Much remains to be known about the contributions of genotypic variations within the bacteria and the host, and environmental factors that lead to the manifestation of the clinical symptoms of melioidosis.
  14. Chan CK, Lee HY, Choi WC, Cho JY, Lee SH
    Eur Spine J, 2011 Jul;20 Suppl 2:S217-21.
    PMID: 20938789 DOI: 10.1007/s00586-010-1585-5
    Sciatica-like leg pain can be the main presenting symptom in patients with cervical cord compression. It is a false localizing presentation, which may lead to missed or delayed diagnosis, resulting in the wrong plan of management, especially in the presence of concurrent lumbar lesions. Medical history, physical findings and the results of imaging studies were reviewed in two cases of cervical cord compressions, which presented with sciatica-like leg pain. There was multi-level cervical spondylosis with cord compression in the first patient and the second patient had two levels of cervical disc herniation with cord compression. In both cases, there were co-existing lumbar lesions, which could be responsible for the presentation of the leg pain. Cervical blocks were diagnostic in identifying the level responsible for the leg pain and it was confirmed so after cervical decompressive surgery in both cases, which brought significant pain relief. Funicular leg pain is a rare presentation of cervical cord compression. It is a referred pain due to the irritation of the ascending spinothalamic tract. Cervical blocks were successful in identifying the cause of funicular pain in our cases and this may pave the way for further studies to establish the role of cervical blocks as a diagnostic tool for funicular pain caused by cord compression.
  15. Lee SH, Chong CE, Lim BS, Chai SJ, Sam KK, Mohamed R, et al.
    Diagn Microbiol Infect Dis, 2007 Jul;58(3):263-70.
    PMID: 17350202
    Burkholderia pseudomallei is a Gram-negative saprophytic soil bacterium, which is the etiologic agent of melioidosis, a severe and fatal infectious disease occurring in human and animals. Distinct clinical and animal isolates have been shown to exhibit differences in phenotypic trait such as growth rate, colony morphology, antimicrobial resistance, and virulence. This study was carried out to gain insight into the intrinsic differences between 4 clinical and 6 animal B. pseudomallei isolates from Malaysia. The 16S rRNA-encoding genes from these 10 isolates of B. pseudomallei were sequenced to confirm the identity of these isolates along with the avirulent Burkholderia thailandensis. The nucleotide sequences indicated that the 16S rRNA-encoding genes among the 10 B. pseudomallei isolates were identical to each other. However, the nucleotide sequence differences in the 16S rRNA-encoding genes appeared to be B. pseudomallei and B. thailandensis specific. The growth rate of all B. pseudomallei isolates was determined by generating growth curves at 37 degrees C for 72 h. The isolates were found to differ in growth rates with doubling time varying from 1.5 to 2.3 h. In addition, the B. pseudomallei isolates exhibited considerable variation in colony morphology when grown on Ashdown media, brain-heart infusion agar, and Luria-Bertani agar over 9 days of observation. Antimicrobial susceptibility tests indicated that 80% of the isolates examined were Amp(R) Cb(R) Kn(R) Gm(R) Chl(S) Te(S). Virulence of the B. pseudomallei clinical and animal isolates was evaluated in B. pseudomallei-susceptible BALB/c mice. Most of the clinical isolates were highly virulent. However, virulence did not correlate with isolate origin since 2 of the animal isolates were also highly virulent.
  16. Lim HH, Domala Z, Joginder S, Lee SH, Lim CS, Abu Bakar CM
    Br J Ind Med, 1984 Nov;41(4):445-9.
    PMID: 6498108 DOI: 10.1136/oem.41.4.445
    A study was carried out to determine the health effects of rice husk dust in Malaysian rice millers. The study population consisted of 122 male Malay workers from three rice mills, with 42 controls of similar age, sex, ethnic group, and agricultural work background. Interviews using standardised questionnaires, physical examination, total and differential white cell counts, chest radiographs, and lung function tests were performed on each of the millers and the controls. Environmental dust monitoring was also carried out in the three rice mills. Clinical, haematological, and radiological findings suggest that a distinct clinical syndrome seems to be associated with exposure to rice husk dust. The manifestations of this "rice millers' syndrome" include acute and chronic irritant effects affecting the eyes, skin, and upper respiratory tract; allergic responses such as nasal catarrh, tightness of chest, asthma, and eosinophilia; and radiological opacities in the chest, probably representing early silicosis or extrinsic allergic alveolitis.
  17. Tan SY, Lim CS, Teo SM, Lee SH, Razack A, Loh CS
    Med J Malaysia, 2003 Dec;58(5):769-70.
    PMID: 15190667
    We report here a case of a kidney transplant recipient in whom the ureter was initially implanted into the peritoneum. Excessive ultrafiltration volume and reversal of serum vs dialysate creatinine ratio when the patient was recommenced on continuous ambulatory peritoneal dialysis first suggested the diagnosis which was subsequently confirmed by a plain abdominal x-ray demonstrating placement of ureteric stent in the peritoneum. This rare complication was successfully corrected with surgical re-implantation of ureter into the bladder and 5 years later, the patient remains well with good graft function.
  18. Bose RJC, Tharmalingam N, Choi Y, Madheswaran T, Paulmurugan R, McCarthy JR, et al.
    Int J Nanomedicine, 2020;15:8437-8449.
    PMID: 33162754 DOI: 10.2147/IJN.S271850
    Background: Lipid polymer hybrid nanoparticles (LPHNPs) have been widely investigated in drug and gene delivery as well as in medical imaging. A knowledge of lipid-based surface engineering and its effects on how the physicochemical properties of LPHNPs affect the cell-nanoparticle interactions, and consequently how it influences the cytological response, is in high demand.

    Methods: Herein, we have engineered antibiotic-loaded (doxycycline or vancomycin) LPHNPs with cationic and zwitterionic lipids and examined the effects on their physicochemical characteristics (size and charge), antibiotic entrapment efficiency, and the in vitro intracellular bacterial killing efficiency against Mycobacterium smegmatis or Staphylococcus aureus infected macrophages.

    Results: The incorporation of cationic or zwitterionic lipids in the LPHNP formulation resulted in a size reduction in LPHNPs formulations and shifted the surface charge of bare NPs towards positive or neutral values. Also observed were influences on the drug incorporation efficiency and modulation of the drug release from the biodegradable polymeric core. The therapeutic efficacy of LPHNPs loaded with vancomycin was improved as its minimum inhibitory concentration (MIC) (2 µg/mL) versus free vancomycin (4 µg/mL). Importantly, our results show a direct relationship between the cationic surface nature of LPHNPs and its intracellular bacterial killing efficiency as the cationic doxycycline or vancomycin loaded LPHNPs reduced 4 or 3 log CFU respectively versus the untreated controls.

    Conclusion: In our study, modulation of surface charge in the nanomaterial formulation increased macrophage uptake and intracellular bacterial killing efficiency of LPHNPs loaded with antibiotics, suggesting alternate way for optimizing their use in biomedical applications.

  19. Md Tahir P, Liew WP, Lee SY, Ang AF, Lee SH, Mohamed R, et al.
    Waste Manag, 2019 Dec;100:128-137.
    PMID: 31536923 DOI: 10.1016/j.wasman.2019.09.002
    Oil palm empty fruit bunch (EFB) is the most significant waste generated from the agricultural industry in Malaysia. Composting is one of the potential approaches to utilize EFB. However, composting of EFB is a time-consuming process, thus impractical for industrial application. The composting process can be shortened by introducing competent fungi into an optimal EFB composting system. This study was conducted to isolate and identify competent fungi that can naturally compost EFB. Samplings were carried out at eight different time points over a 20-weeks experimental period. The physical properties of EFB samples such as pH, residual oil content, and moisture content were measured and the EFB composting process that was indicated by the contents of cellulose, hemicellulose, and lignin were assessed. The fungal growth, distribution, and lignocellulolytic enzyme activities were evaluated. The results indicated that the changes in physical properties of EFB were correlated to the fungal growth. The gradual reduction in moisture content and residual oil, and the increment in pH values in EFB samples throughout the experimental period resulted in reduced fungal growth and diversity. Such phenomenon delayed EFB composting process as revealed by the changes in EFB lignin, hemicellulose, and cellulose contents. The most dominant and resilient fungi (Lichtheimia ramosa and Neurospora crassa) survived up to 16 weeks and were capable of producing various lignocellulolytic enzymes. Further understanding of these factors that would contribute to effective EFB composting could be useful for future industrial applications.
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links