Displaying publications 1 - 20 of 40 in total

Abstract:
Sort:
  1. Fulltext Advances in immunotherapy using dendritic cells
    Radhakrishnan, Ammu Kutty
    International e-Journal of Science, Medicine & Education, 2012;6(10):0-0.
    MyJurnal
    The immune system is the host natural defence against cancer. Cancers are caused by progressive growth of the progeny of a single transformed host cell. The immune system is generally not able to mount immune responses to “self-antigens”, due to various mechanisms of immunological tolerance that are in place. This means that despite possessing a natural defence against tumours, many of the cancer patients may not be able
    to mount an effective immune response to fight the tumours. Dendritic cells (DC) are highly specialised in antigen presenting that can initiate and stimulate immune responses. These cells have the ability to stimulate naïve T cell proliferation and perform specific stimulatory and tolerogenic functions respectively. When the DC are activated by antigens, these cells
    undergoes further maturation and migrate to secondary lymphoid tissues, present antigen to T cells and finally induce an immune response. The ability of the DC to activate naïve and primed T-lymphocytes makes these cells a good candidate to be explored as a potential immunotherapeutic agent that can modulate antitumour immune responses in the affected host.
  2. Fulltext The influence of admission qualifications on the performance of first and second year medical students at the International Medical University
    Radhakrishnan, Ammu Kutty, Lee, Nagarajah, Young, Mei-Ling
    International e-Journal of Science, Medicine & Education, 2012;6(2):10-17.
    MyJurnal
    Background: Medical schools have long been concerned with establishing a suitable process of
    admission. The criteria used to select students have traditionally focussed on high academic achievement. Method: The International Medical University (IMU) accepts students from a wide range of pre-university entry qualifications for admission into the medical programme. The criteria for the various pre-university entry qualifications used by the IMU were agreed and accepted by the IMU Academic Council (AC), which consist of deans of the IMU’s partner medical schools (PMS). In this study, the various entry qualifications were first grouped into five categories based on the educational pedagogy. Then, this was aligned with the entry qualification data of all students who had been admitted into the IMU medical programme for the period of December 1993 to March 2000. During this period 1,281 students were enrolled into the IMU medical programme. The relationship between the five groups of pre-university entry qualifications and the students’ academic achievement in three end-ofsemester (EOS) examinations namely EOS 1, EOS 3, and EOS 5 were analysed. Results: Students with better grades in their preuniversity examinations showed better performance in their EOS examinations, regardless of the subjects that they took at the pre-university level. Cluster analysis revealed that students who came in with certain preuniversity qualifications generally performed poorly than the more conventional qualifications. However,
    after their first year in medical school, there were no significant differences in the clustering of the students. Conclusion: Students with better grades in their preuniversity examinations showed better performance in their EOS examinations, regardless of the science subjects that they took at the pre-university level.
  3. Fulltext Is there a genetic variation association in the IL-10 and TNF alpha promoter gene with gestational diabetes mellitus?
    Montazeri S, Nalliah S, Radhakrishnan AK
    Hereditas, 2010 Apr;147(2):94-102.
    PMID: 20536548 DOI: 10.1111/j.1601-5223.2009.02134.x
    Gestational diabetes mellitus (GDM), defined as carbohydrate intolerance diagnosed for the first time during pregnancy, affects both maternal and fetal health. Possession of a specific genetic polymorphism can be a predisposing factor for susceptibility to some diseases. The aim of this study was to investigate the association between single nucleotide polymorphisms (SNP) in the promoter gene of interleukin-10 (IL-10) as well as tumor necrosis factor-alpha (TNF alpha) with the development of GDM. Two hundred and twelve consecutive series of eligible normal pregnant women (controls) and gestational diabetes mellitus women were selected based on the study's inclusion and exclusion criteria. DNA was extracted from blood and genotyped for IL-10 at three positions and TNF alpha for gene polymorphism using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Plasma levels of IL-10 and TNF alpha at different gestational periods as well as postpartum were quantified using enzyme linked immunosorbent assay (ELISA). The results of the study showed that the difference in the frequency of SNP at position -597 in the promoter of the human IL-10 gene between the control and GDM groups was statistically significant (p < 0.05). In contrast, there was no significant difference in the frequency of SNP at the other two sites in the promoter region of the human IL-10 gene (-824 and -1082) as well as position -308 in the promoter of the human TNF-alpha (p > 0.05). In addition, there was no significant difference between the two groups in terms of plasma levels of IL-10 as well as TNF alpha in different stages of pregnancy. SNP at position -597 was significantly associated with the development of GDM and shows potential for use as a predictive marker for GDM.
  4. Fulltext Tocotrienols are good adjuvants for developing cancer vaccines
    Hafid SR, Radhakrishnan AK, Nesaretnam K
    BMC Cancer, 2010;10:5.
    PMID: 20051142 DOI: 10.1186/1471-2407-10-5
    Dendritic cells (DCs) have the potential for cancer immunotherapy due to their ability to process and present antigens to T-cells and also in stimulating immune responses. However, DC-based vaccines have only exhibited minimal effectiveness against established tumours in mice and humans. The use of appropriate adjuvant enhances the efficacy of DC based cancer vaccines in treating tumours.
  5. Association between polymorphisms in human tumor necrosis factor-alpha (--308) and -beta (252) genes and development of gestational diabetes mellitus
    Montazeri S, Nalliah S, Radhakrishnan AK
    Diabetes Res Clin Pract, 2010 May;88(2):139-45.
    PMID: 20189261 DOI: 10.1016/j.diabres.2010.01.028
    OBJECTIVE: The aim of this study is to investigate if an association exists between single nucleotide polymorphism (SNP) in the tumor necrosis factor-alpha (TNF-alpha) and TNF-beta genes.
    METHODS: The DNA was extracted and SNP in the human TNF-alpha and TNF-beta genes at positions -308 (G/A) and 252 (A/G), respectively, was analyzed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Plasma levels of TNF-alpha in different stages of pregnancy were quantified using enzyme linked immunosorbent assay (ELISA).
    RESULTS: There was no significant difference in genotype and allele frequency of SNP at position -308 (G/A) in the promoter region of the human TNF-alpha gene as well as the SNP at position 252 (A/G) in the human TNF-beta gene between the GDM and control subjects. Using the logistic regression model, it was found that the SNP in the TNF-alpha as well as TNF-beta were not associated with development of GDM. In addition, the TNF-alpha levels in the plasma of GDM and control mothers were not significantly different.
    CONCLUSIONS: In the population studied, the SNP in position -308 (G/A) of the human TNF-alpha or in position 252 (A/G) of the human TNF-beta gene is not an independent risk factor or a predictor for GDM.
  6. Anti-proliferative and mutagenic activities of aqueous and methanol extracts of leaves from Pereskia bleo (Kunth) DC (Cactaceae)
    Er HM, Cheng EH, Radhakrishnan AK
    J Ethnopharmacol, 2007 Sep 25;113(3):448-56.
    PMID: 17698306
    The anti-proliferative effects of the aqueous and methanol extracts of leaves of Pereskia bleo (Kunth) DC (Cactaceae) against a mouse mammary cancer cell line (4T1) and a normal mouse fibroblast cell line (NIH/3T3) were evaluated under an optimal (in culture medium containing 10% foetal bovine serum (FBS)) and a sub-optimal (in culture medium containing 0.5% FBS) conditions. Under the optimal condition, the aqueous extract showed a significant (p<0.05) anti-proliferative effect at 200 microg/mL and 300 microg/mL in 4T1 cells and 300 microg/mL in NIH/3T3 cells, whereas the methanol extract did not show any notable anti-proliferative effect in these cell lines, at any of the concentrations tested. Under the sub-optimal condition, the aqueous extract showed a significant (p<0.05) anti-proliferative effect at 200 microg/mL and 300 microg/mL in NIH/3T3 cells, whilst the methanol extract showed a significant (p<0.05) anti-proliferative effect at 200 microg/mL and 300 microg/mL in both cell lines. An upward trend of apoptosis was observed in both 4T1 and NIH/3T3 cells treated with increasing concentrations of the aqueous extract. The level of apoptosis observed at all the concentrations of the aqueous extract tested was consistently higher than necrosis. There was a significant (p<0.05) increase in the level of necrosis observed in the 4T1 cells treated with 300 microg/mL of the methanol extract. Generally, the level of necrosis was noted to be higher than that of apoptosis in the methanol extract-treated cells. The mutagenicity assay performed showed that in the absence of S-9 liver metabolic activation, the extract was not mutagenic up to the concentration of 165 microg/mL . However, in the presence of S-9 liver metabolic activation, the aqueous extract was mutagenic at all the concentrations tested. This study shows that both the aqueous and methanol extracts of the leaves from Pereskia bleo (Kunth) DC (Cactaceae) do not have appreciable anti-proliferative effect on the 4T1 and NIH/3T3 cells as the EC(50) values obtained are greater than 50 microg/mL when tested under optimal culture condition. Moreover, the aqueous extract may form mutagenic compound(s) upon the metabolisation by liver enzymes.
  7. Fulltext Protective Mechanisms of Flavonoids in Parkinson's Disease
    Magalingam KB, Radhakrishnan AK, Haleagrahara N
    Oxid Med Cell Longev, 2015;2015:314560.
    PMID: 26576219 DOI: 10.1155/2015/314560
    Parkinson's disease is a chronic, debilitating neurodegenerative movement disorder characterized by progressive degeneration of dopaminergic neurons in the substantia nigra pars compacta region in human midbrain. To date, oxidative stress is the well accepted concept in the etiology and progression of Parkinson's disease. Hence, the therapeutic agent is targeted against suppressing and alleviating the oxidative stress-induced cellular damage. Within the past decades, an explosion of research discoveries has reported on the protective mechanisms of flavonoids, which are plant-based polyphenols, in the treatment of neurodegenerative disease using both in vitro and in vivo models. In this paper, we have reviewed the literature on the neuroprotective mechanisms of flavonoids in protecting the dopaminergic neurons hence reducing the symptoms of this movement disorder. The mechanism reviewed includes effect of flavonoids in activation of endogenous antioxidant enzymes, suppressing the lipid peroxidation, inhibition of inflammatory mediators, flavonoids as a mitochondrial target therapy, and modulation of gene expression in neuronal cells.
  8. Modulatory effects of mesenchymal stem cells on leucocytes and leukemic cells: A double-edged sword?
    Low JH, Ramdas P, Radhakrishnan AK
    Blood Cells Mol. Dis., 2015 Dec;55(4):351-7.
    PMID: 26460259 DOI: 10.1016/j.bcmd.2015.07.017
    Mesenchymal stem cells (MSCs) have drawn much attention amongst stem cell researchers in the past few decades. The ability of the MSC to differentiate into cells of mesodermal and non-mesodermal origins has made them an attractive approach for cell-based therapy and regenerative medicine. The MSCs have immunosuppressive activities that may have considerable therapeutic values in autoimmune diseases. However, despite the many beneficial effects reported, there is a growing body of evidence, which suggests that MSCs could be a culprit of enhanced tumour growth, metastasis and drug resistance in leukaemia, via some modulatory effects. Many controversies regarding the interactions between MSCs and leukaemia still exist. Furthermore, the role of MSCs in leukemogenesis and its progression remain largely unknown. Hence it is important to understand how the MSCs modulate leukaemia before these cells could be safely used in the treatment of leukaemia patients.
  9. Fulltext Bioactive Compounds: Natural Defense Against Cancer?
    Subramaniam S, Selvaduray KR, Radhakrishnan AK
    Biomolecules, 2019 11 21;9(12).
    PMID: 31766399 DOI: 10.3390/biom9120758
    Cancer is a devastating disease that has claimed many lives. Natural bioactive agents from plants are gaining wide attention for their anticancer activities. Several studies have found that natural plant-based bioactive compounds can enhance the efficacy of chemotherapy, and in some cases ameliorate some of the side-effects of drugs used as chemotherapeutic agents. In this paper, we have reviewed the literature on the anticancer effects of four plant-based bioactive compounds namely, curcumin, myricetin, geraniin and tocotrienols (T3) to provide an overview on some of the key findings that are related to this effect. The molecular mechanisms through which the active compounds may exert their anticancer properties in cell and animal-based studies also discussed.
  10. Fulltext A Glimpse into the Genome-wide DNA Methylation Changes in 6-hydroxydopamine-induced In Vitro Model of Parkinson's Disease
    Magalingam KB, Somanath SD, Radhakrishnan AK
    Exp Neurobiol, 2023 Jun 30;32(3):119-132.
    PMID: 37403221 DOI: 10.5607/en22035
    A cell-based model of Parkinson's disease (PD) is a well-established in vitro experimental prototype to investigate the disease mechanism and therapeutic approach for a potential anti-PD drug. The SH-SY5Y human neuroblastoma cells and 6-OHDA combo is one of the many neurotoxininduced neuronal cell models employed in numerous neuroscience-related research for discovering neuroprotective drug compounds. Emerging studies have reported a significant correlation between PD and epigenetic alterations, particularly DNA methylation. However, the DNA methylation changes of PD-related CpG sites on the 6-OHDA-induced toxicity on human neuronal cells have not yet been reported. We performed a genome-wide association study (GWAS) using Infinium Epic beadchip array surveying 850000 CpG sites in differentiated human neuroblastoma cells exposed to 6-OHDA. We identified 236 differentially methylated probes (DMPs) or 163 differentially methylated regions (DMRs) in 6-OHDA treated differentiated neuroblastoma cells than the untreated reference group with p<0.01, Δbeta cut-off of 0.1. Among 236 DMPs, hypermethylated DMPs are 110 (47%), whereas 126 (53%) are hypomethylated. Our bioinformatic analysis revealed 3 DMRs that are significantly hypermethylated and associated with neurological disorders, namely AKT1, ITPR1 and GNG7. This preliminary study demonstrates the methylation status of PD-related CpGs in the 6-OHDA-induced toxicity in the differentiated neuroblastoma cells model.
  11. Fulltext Comparing the ability of freshly generated and cryopreserved dendritic cell vaccines to inhibit growth of breast cancer in a mouse model
    Radhakrishnan AK, Sim GC, Cheong SK
    Biores Open Access, 2012 Oct;1(5):239-46.
    PMID: 23515111 DOI: 10.1089/biores.2012.0229
    Repetitive vaccinations with dendritic cell (DC)-based vaccines over long periods of time can break pre-existing tolerance to tumors and achieve clinically relevant immune response. This requires a large number of DCs to be generated under good manufacturing protocol, which is time- and cost intensive. Thus, producing a large numbers of DCs at one time point and cryopreserving these cells in ready-for-use aliquots for clinical application may overcome this constraint. This could also reduce batch-to-batch variations. In this study, we generated DCs from bone marrow obtained from BALB/c mice. Some of the generated DCs were cryopreserved before conducting various tests. There were no significant differences in the morphology and phenotype between cryopreserved and freshly generated DCs. Both types of DCs pulsed with tumor lysate (TL) from 4T1 murine mammary cancer cells (DC+TL) possessed a similar capacity to stimulate the proliferation of T-cells. In addition, cryopreserved and fresh DC pulsed with TL showed similar tumor growth inhibition patterns. Both DCs induced initial retardation of tumor growth (p<0.05) and prolonged the survival (p<0.05) of tumor-bearing mice treated with DC+TL as compared with nontreated control mice. Cryopreserved DCs shared similar therapeutic efficacy to fresh DCs, and this finding lends supports the routine use of cryopreserved DCs in future clinical trials.
  12. Effect of Spirulina (Arthrospira) supplementation on the immune response to tetanus toxoid vaccination in a mouse model
    Chu WL, Quynh le V, Radhakrishnan AK
    J Diet Suppl, 2013 Sep;10(3):229-40.
    PMID: 23927690 DOI: 10.3109/19390211.2013.822452
    The aim of this study was to investigate whether Spirulina (Arthrospira) supplementation could enhance the immune response to tetanus toxoid (TT) vaccine in a mouse model. Vaccination of TT was performed on day 7 and 21 in mice fed daily with Spirulina (50 and 150 mg/kg body weight). Both Spirulina supplementation and TT vaccination did not significantly affect body weight gain of the mice. Supplementation of Spirulina significantly enhanced IgG level (p = .01) after the first but not after the second TT vaccination. The anti-TT IgG levels of the groups that received low dose and high dose of Spirulina were not significantly different. Spirulina supplementation did not show significant effects on in vitro splenocyte proliferation and cytokine (IFN-γ and IL-4) production induced by Con A and TT. This study showed that Spirulina supplementation could enhance primary immune response in terms of antibody production, but not secondary immune response following TT vaccination in a mouse model.
  13. Fulltext Tocotrienol-adjuvanted dendritic cells inhibit tumor growth and metastasis: a murine model of breast cancer
    Abdul Hafid SR, Chakravarthi S, Nesaretnam K, Radhakrishnan AK
    PLoS One, 2013;8(9):e74753.
    PMID: 24069344 DOI: 10.1371/journal.pone.0074753
    Tocotrienol-rich fraction (TRF) from palm oil is reported to possess anti-cancer and immune-enhancing effects. In this study, TRF supplementation was used as an adjuvant to enhance the anti-cancer effects of dendritic cells (DC)-based cancer vaccine in a syngeneic mouse model of breast cancer. Female BALB/c mice were inoculated with 4T1 cells in mammary pad to induce tumor. When the tumor was palpable, the mice in the experimental groups were injected subcutaneously with DC-pulsed with tumor lysate (TL) from 4T1 cells (DC+TL) once a week for three weeks and fed daily with 1 mg TRF or vehicle. Control mice received unpulsed DC and were fed with vehicle. The combined therapy of using DC+TL injections and TRF supplementation (DC+TL+TRF) inhibited (p<0.05) tumor growth and metastasis. Splenocytes from the DC+TL+TRF group cultured with mitomycin-C (MMC)-treated 4T1 cells produced higher (p<0.05) levels of IFN-γ and IL-12. The cytotoxic T-lymphocyte (CTL) assay also showed enhanced tumor-specific killing (p<0.05) by CD8(+) T-lymphocytes isolated from mice in the DC+TL+TRF group. This study shows that TRF has the potential to be used as an adjuvant to enhance effectiveness of DC-based vaccines.
  14. Fulltext Supplementation with natural forms of vitamin E augments antigen-specific TH1-type immune response to tetanus toxoid
    Radhakrishnan AK, Mahalingam D, Selvaduray KR, Nesaretnam K
    Biomed Res Int, 2013;2013:782067.
    PMID: 23936847 DOI: 10.1155/2013/782067
    This study compared the ability of three forms of vitamin E [tocotrienol-rich fraction (TRF), alpha-tocopherol (α-T), and delta-tocotrienol (δ-T3)] to enhance immune response to tetanus toxoid (TT) immunisation in a mouse model. Twenty BALB/c mice were divided into four groups of five mice each. The mice were fed with the different forms of vitamin E (1 mg) or vehicle daily for two weeks before they were given the TT vaccine [4 Lf] intramuscularly (i.m.). Booster vaccinations were given on days 28 and 42. Serum was collected (days 0, 28, and 56) to quantify anti-TT levels. At autopsy, splenocytes harvested were cultured with TT or mitogens. The production of anti-TT antibodies was augmented (P < 0.05) in mice that were fed with δ-T3 or TRF compared to controls. The production of IFN-γ and IL-4 by splenocytes from the vitamin E treated mice was significantly (P < 0.05) higher than that from controls. The IFN-γ production was the highest in animals supplemented with δ-T3 followed by TRF and finally α-T. Production of TNF-α was suppressed in the vitamin E treated group compared to vehicle-supplemented controls. Supplementation with δ-T3 or TRF can enhance immune response to TT immunisation and production of cytokines that promote cell-mediated (TH1) immune response.
  15. Fulltext Efficacy of Emu Oil Transfersomes for Local Transdermal Delivery of 4-OH Tamoxifen in the Treatment of Breast Cancer
    Sundralingam U, Chakravarthi S, Radhakrishnan AK, Muniyandy S, Palanisamy UD
    Pharmaceutics, 2020 Aug 25;12(9).
    PMID: 32854385 DOI: 10.3390/pharmaceutics12090807
    Oral tamoxifen used in the prevention and treatment of ductal carcinoma in situ (DCIS) (estrogen-positive) patients has limited acceptance, due to its adverse side effects. The efficacy of tamoxifen is related to its major metabolite, 4-hydroxytamoxifen. Local transdermal therapy of 4-hydroxytamoxifen to the breast might avert the toxicity of oral tamoxifen, while maintaining efficacy. We aim to study the skin irritancy, as well as to evaluate the efficacy of the developed transfersome formulations, with/without emu oil, using a syngeneic mouse model of breast cancer. We also quantified tamoxifen/4-hydroxytamoxifen concentrations in blood plasma and performed histopathology. The skin irritancy test showed that the pure emu oil and transfersome formulations with or without the emu oil did not cause skin irritancy in the animals studied. A sensitive and specific LC-MS/MS method for the quantification of tamoxifen and 4-hydroxytamoxifen was developed and validated. Studies on tumor volume and necrosis (histopathology) using the breast cancer mouse model showed that the 4-OHT transfersomal formulations, with and without emu oil, showed comparable efficacy with that of orally administered tamoxifen. However, the transfersomal formulations, with and without emu oil, resulted in significantly lower (10.24 ± 0.07 and 32.45 ± 0.48 ng/mL, respectively) plasma concentrations of 4-hydroxytamoxifen, compared to the oral tamoxifen (TAMX) group (634.42 ± 7.54 ng/mL). This study demonstrated the potential use of emu oil in a local transdermal formulation for the treatment of breast cancer and its reduced adverse effects.
  16. Fulltext Tocotrienols Ameliorate Neurodegeneration and Motor Deficits in the 6-OHDA-Induced Rat Model of Parkinsonism: Behavioural and Immunohistochemistry Analysis
    Kumari M, Ramdas P, Radhakrishnan AK, Kutty MK, Haleagrahara N
    Nutrients, 2021 May 10;13(5).
    PMID: 34068460 DOI: 10.3390/nu13051583
    Parkinson's disease (PD) is a debilitating neurodegenerative disease, which progresses over time, causing pathological depigmentation of the substantia nigra (SN) in the midbrain due to loss of dopaminergic neurons. Emerging studies revealed the promising effects of some nutrient compounds in reducing the risk of PD. One such nutrient compound that possess neuroprotective effects and prevents neurodegeneration is tocotrienol (T3), a vitamin E family member. In the present study, a single dose intracisternal injection of 250 µg 6-hydroxydopamine (6-OHDA) was used to induce parkinsonism in male Sprague Dawley (SD) rats. Forty-eight hours post injection, the SD rats were orally supplemented with alpha (α)- and gamma (γ)-T3 for 28 days. The neuroprotective effects of α- and γ-T3 were evaluated using behavioural studies and immunohistochemistry (IHC). The findings from this study revealed that supplementation of α- and γ-T3 was able to ameliorate the motor deficits induced by 6-OHDA and improve the neuronal functions by reducing inflammation, reversing the neuronal degradation, and preventing further reduction of dopaminergic neurons in the SN and striatum (STR) fibre density.
  17. Medical students' orientation toward lifelong learning in an outcome-based curriculum and the lessons learnt
    Ramamurthy S, Er HM, Devi Nadarajah V, Radhakrishnan AK
    Med Teach, 2021 Jul;43(sup1):S6-S11.
    PMID: 31408404 DOI: 10.1080/0142159X.2019.1646894
    BACKGROUND: Lifelong learning (LL) is an important outcome of medical training. The objective of this study is to measure the orientation of medical students toward LL and to determine the types of self-directed learning (SDL) activities that contribute toward LL skills.

    METHODS: The Jefferson Scale of Physician Lifelong Learning for medical student (JeffSPLL-MS) questionnaire was used. Factor analysis was performed, Cronbach's alpha and effect size were calculated. The types of learning activities that contribute to LL skills were identified.

    RESULTS: Three-factor structure emerged from the factor analysis and were identified as learning beliefs and motivation, skills in seeking information and attention to learning opportunities. A significant increase (p 

  18. Tocotrienols Modulate Breast Cancer Secretomes and Affect Cancer-Signaling Pathways in MDA-MB-231 Cells: A Label-Free Quantitative Proteomic Analysis
    Ramdas P, Radhakrishnan AK, Abdu Sani AA, Abdul-Rahman PS
    Nutr Cancer, 2019;71(8):1263-1271.
    PMID: 31084432 DOI: 10.1080/01635581.2019.1607407
    Tocotrienols (T3), a family of vitamin E, are reported to possess potent anti-cancer effects but the molecular mechanisms behind these effects still remain unclear. The aim of this study was to investigate how T3 exert anti-cancer effects on MDA-MB-231 human breast cancer cells. The MDA-MB-231 cells were chosen for this study as they are triple-negative and highly metastatic cells, which form aggressive tumors in experimental models. The MDA-MB-231 cells were treated with varying concentrations (0-20 µg mL-1) of gamma (γ) or delta (δ) T3 and the secretome profiles of these cells treated with half maximal inhibitory concentration (IC50) of γT3 (5.8 µg mL-1) or δT3 (4.0 µg mL-1) were determined using label-free quantitative proteomic strategy. A total of 103, 174 and 141 proteins were identified with ProteinLynx Global Server (PLGS) score of more than 200 and above 25% sequence coverage in the untreated control and T3-treated cell culture supernatant respectively. A total of 18 proteins were dysregulated between untreated control and T3 (δT3 or γT3) treated conditions. The results showed that T3 treatment downregulated the exogenous Cathepsin D and Serpine1 proteins but upregulated Profilin-1 protein, which play a key role in breast cancer in the MDA-MB-231 cells. These findings strongly suggest that T3 may induce differential expression of secreted proteins involved in the cytoskeletal regulation of RHO GTPase signaling pathway.
  19. Fulltext Single nucleotide polymorphism in the promoter of the human interleukin-13 gene is associated with asthma in Malaysian adults
    Radhakrishnan AK, Raj VL, Tan LK, Liam CK
    Biomed Res Int, 2013;2013:981012.
    PMID: 23865080 DOI: 10.1155/2013/981012
    Asthma susceptibility genes are mapped to a region on human chromosome 5q31-q33, which contains a cluster of proinflammatory cytokine genes such as interleukin-13 (IL-13), which is associated with asthma. This study investigated the allele frequencies of two single nucleotide polymorphisms (SNPs) (-1111C>T and 4257C>A) in the IL-13 gene between asthmatics and healthy volunteers as well as the relationship between these SNPs and IL-13 production. DNA extracted from buffy coat of asthmatic and control subjects was genotyped using the PCR-RFLP method. Amount of IL-13 produced by mitogen-stimulated peripheral blood leucocytes PBLs (PBLs) was determined by ELISA. The frequencies of the -1111C and 4257G wild-type alleles were 0.52 and 0.55 in asthmatics and were 0.67 and 0.56 in controls. A significant (P < 0.05) association was found between genotype and allele frequencies of SNP at position -1111C>T between asthmatic and control groups (OR, 1.810; 95% CI = 1.184 to 2.767; P < 0.05). The mitogen-stimulated PBLs from asthmatics produced higher amounts of IL-13 production (P < 0.001). The 4257GA heterozygous and 4257AA homozygous mutant alleles were associated with higher IL-13 production in asthmatics (P < 0.05). Our results show that the -1111T mutant allele are associated with asthma and the 4257A mutant alleles are associated with elevated IL-13 production.
  20. Fulltext In vivo toxicity evaluation of a standardized extract of Syzygium aqueum leaf
    Manaharan T, Chakravarthi S, Radhakrishnan AK, Palanisamy UD
    Toxicol Rep, 2014;1:718-725.
    PMID: 28962285 DOI: 10.1016/j.toxrep.2014.09.006
    In this study, the acute and subchronic toxicity effect of the Syzygium aqueum leaf extract (SA) was evaluated. For the acute toxicity study, a single dose of 2000 mg/kg of the SA was given by oral-gavage to male Sprague-Dawley (SD) rats. The rats were observed for mortality and toxicity signs for 14 days. In the subchronic toxicity study the SA was administered orally at doses of 50, 100, and 200 mg/kg per day for 28 days to male SD rats. The animals were sacrificed at the end of the experiment. The parameters measured including food and water intake, body weight, absolute and relative organ weight, blood biochemical tests and histopathology observation. In both the acute and subchronic toxicity studies, SA did not show any visible signs of toxicity. There were also no significant differences between the control and SA treated rats in terms of their food and water intake, body weight, absolute and relative organ weight, biochemical parameters or gross and microscopic appearance of the organs. There were no acute or subchronic toxicity observed and our results indicate that this extract could be devoid of any toxic risk. This is the first in vivo study reported the safety and toxicity of SA.
Related Terms
    Try searching for something
Filters
Contact Us

Please provide feedback to Administrator ([email protected])

External Links