Displaying publications 1 - 20 of 81 in total

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  1. Looi LM, Azura WW, Cheah PL, Ng MH
    Pathology, 2001 Aug;33(3):283-6.
    PMID: 11523925
    This investigation was carried out to gain insight into the prevalence of pS2 expression in invasive ductal breast carcinoma in the Malaysian population and its correlation with oestrogen receptor (ER) protein expression and tumour aggressiveness. Seventy consecutive infiltrating ductal breast carcinomas treated with mastectomy and axillary lymph node clearance were investigated, using the standard avidin-biotin complex immunoperoxidase method with microwave antigen retrieval and commercial monoclonal antibodies (Dako), for expression of pS2 and human ER. This was correlated against histological grade (modified Bloom and Richardson) and the presence of axillary lymph node metastasis of these carcinomas. Four (5.7%) were grade 1, 40 (57.1%) grade 2 and 26 (37.1%) grade 3 tumours. A total of 45 (64%) showed histological evidence of axillary lymph node metastasis. Forty (57%) were ER-positive, while 31 (44%) were pS2-positive. There was a statistically significant correlation between pS2 and ER expressions (chi2-test with Yates correction: P<0.005). There was no correlation between pS2 expression and histological grade (P>0.1) and the presence of lymph node metastasis (P>0.1). Our findings support the views that pS2 may be a co-marker of endocrine responsiveness in invasive breast cancer and that it does not influence breast cancer biology in terms of potential for metastatic spread.
  2. Cheah PL, Looi LM, Ng MH, Sivanesaratnam V
    J Clin Pathol, 2002 Jan;55(1):22-6.
    PMID: 11825919
    AIM: Telomerase activity was studied in invasive uterine cervical carcinoma to assess whether it was activated during cervical malignant transformation and to look for a possible association with human papillomavirus (HPV) infection in a set of Malaysian patients.

    METHODS: Histologically confirmed invasive cervical carcinoma and benign cervices were assayed for telomerase activity using a commercial telomerase polymerase chain reaction (PCR) enzyme linked immunosorbent assay kit. The same cases were subjected to PCR detection of HPV using type specific (HPV types 6b, 11, 16, and 18) followed by L1 open reading frame (ORF) consensus primers.

    RESULTS: HPV was detected in 18 (13 HPV-16, one HPV-6b, four only L1 ORF) of 20 invasive cervical carcinoma and one (only L1 ORF) of 19 benign cervices. Raised telomerase activity (A(450 nm) > 0.215) was detected in 11 cervical carcinomas, with A(450 nm) ranging between 0.238 and 21.790 (mean, 3.952) in positive squamous carcinomas, whereas A(450 nm) was only 0.222 in the one positive adenosquamous carcinoma. Five of 11 cervical carcinomas in stage I, three of six in stage II, both in stage III, and the only case in stage IV showed telomerase activation. Increased telomerase activity was noted in five of the 12 lymph node negative, five of the seven lymph node status unknown cases, and the one case with presumed lymph node metastasis. Ten of 18 HPV positive and one of two HPV negative cervical carcinomas showed telomerase upregulation.

    CONCLUSIONS: Telomerase is activated in invasive cervical carcinoma. Although larger studies are needed, there seems to be no clear association between telomerase upregulation and HPV status, although there is a suggestion of increased telomerase activity in squamous carcinomas and late stage disease.

  3. Phang MY, Ng MH, Tan KK, Aminuddin BS, Ruszymah BH, Fauziah O
    Med J Malaysia, 2004 May;59 Suppl B:198-9.
    PMID: 15468886
    Tricalcium phosphate/hydroxyapatite (TCP/HA), hydroxyapatite (HA), chitosan and calcium sulphate (CaSO4) were studied and evaluated for possible bone tissue engineered construct acting as good support for osteogenic cells to proliferate, differentiate, and eventually spread and integrate into the scaffold. Surface morphology visualized by SEM showed that scaffold materials with additional fibrin had more cell densities attached than those without, depicting that the presence of fibrin and collagen fibers were truly a favourite choice of cells to attach. In comparison of various biomaterials used incorporated with fibrin, TCP/HA had the most cluster of cells attached.
  4. Shamsul BS, Aminuddin BS, Ng MH, Ruszymah BH
    Med J Malaysia, 2004 May;59 Suppl B:196-7.
    PMID: 15468885
    Bone marrow harvested by aspiration contains connective tissue progenitor cells which can be selectively isolated and induced to express bone phenotype in vitro. The osteoblastic progenitor can be estimated by counting the number of cells attach using the haemacytometer. This study was undertaken to test the hypothesis that human aging is associated with a significant change on the number of osteoblastic progenitors in the bone marrow. Bone marrow aspirates were harvested from 38 patients, 14 men (age 11-70) and 24 women (age 10-70) and cultured in F12: DMEM (1:1). In total 15 bone marrow samples have been isolated from patients above 40 years old (men/women) of age. Fourteen (93.3%) of this samples failed to proliferate. Only one (6.7%) bone marrow sample from a male patient, aged 59 years old was successfully cultured. Seventy percent (16/23) of the samples from patient below than 40 years old were successfully cultured. However, our observation on the survival rate for cells of different gender from patient below 40 years old does not indicate any significant difference. From this study, we conclude that the growth of bone marrow stromal cells possibly for bone engineering is better from bone marrow aspirates of younger patient.
  5. Tan KK, Aminuddin BS, Tan GH, Sabarul Afian M, Ng MH, Fauziah O, et al.
    Med J Malaysia, 2004 May;59 Suppl B:43-4.
    PMID: 15468810
    The strategy used to generate tissue-engineered bone construct, in view of future clinical application is presented here. Osteoprogenitor cells from periosteum of consenting scoliosis patients were isolated. Growth factors viz TGF-B2, bFGF and IGF-1 were used in concert to increase cell proliferation during in vitro cell expansion. Porous tricalcium phosphate (TCP)-hydroxyapatite (HA) scaffold was used as the scaffold to form 3D bone construct. We found that the addition of growth factors, greatly increased cell growth by 2 to 7 fold. TCP/HA proved to be the ideal scaffold for cell attachment and proliferation. Hence, this model will be further carried out on animal trial.
  6. Ng MH, Aminuddin BS, Tan KK, Tan GH, Sabarul Afian M, Ruszymah BH
    Med J Malaysia, 2004 May;59 Suppl B:41-2.
    PMID: 15468809
    Bone marrow stem cells (BMSC), known for its multipotency to differentiate into various mesenchymal cells such as chodrocyte, osteoblasts, adipocytes, etc, have been actively applied in tissue engineering. BMSC have been successfully isolated from bone marrow aspirate and bone marrow scraping from patients of various ages (13-56 years) with as little as 2ml to 5ml aspirate. BMSC isolated from our laboratory showed the presence of a heterogenous population that showed varying prevalence of surface antigens and the presence of telomerase activity albeit weak. Upon osteogenic induction, alkaline phosphatase activity and mineralization activity were observed.
  7. Ng MH, Choo YM, Ma AN, Chuah CH, Hashim MA
    Lipids, 2004 Oct;39(10):1031-5.
    PMID: 15691027
    Previous reports showed that vitamin E in palm oil consists of various isomers of tocopherols and tocotrienols [alpha-tocopherol (alpha-T), alpha-tocotrienol, gamma-tocopherol, gamma-tocotrienol, and delta-tocotrienol), and this is normally analyzed using silica column HPLC with fluorescence detection. In this study, an HPLC-fluorescence method using a C30 silica stationary phase was developed to separate and analyze the vitamin E isomers present in palm oil. In addition, an alpha-tocomonoenol (alpha-T1) isomer was quantified and characterized by MS and NMR. (alpha-T1 constitutes about 3-4% (40+/-5 ppm) of vitamin E in crude palm oil (CPO) and is found in the phytonutrient concentrate (350+/-10 ppm) from palm oil, whereas its concentration in palm fiber oil (PFO) is about 11% (430+/-6 ppm). The relative content of each individual vitamin E isomer before and after interesterification/transesterification of CPO to CPO methyl esters, followed by vacuum distillation of CPO methyl esters to yield the residue, remained the same except for alpha-T and gamma-T3. Whereas alpha-T constitutes about 36% of the total vitamin E in CPO, it is present at a level of 10% in the phytonutrient concentrate. On the other hand, the composition of gamma-T3 increases from 31% in CPO to 60% in the phytonutrient concentrate. Vitamin is present at 1160+/-43 ppm, and its concentrations in PFO and the phytonutrient concentrate are 4,040+/-41 and 13,780+/-65 ppm, respectively. The separation and quantification of alpha-T1 in palm oil will lead to more in-depth knowledge of the occurrence of vitamin E in palm oil.
  8. Choo YM, Ng MH, Ma AN, Chuah CH, Hashim MA
    Lipids, 2005 Apr;40(4):429-32.
    PMID: 16028723
    The application of supercritical fluid chromatography (SFC) coupled with a UV variable-wavelength detector to isolate the minor components (carotenes, vitamin E, sterols, and squalene) in crude palm oil (CPO) and the residual oil from palm-pressed fiber is reported. SFC is a good technique for the isolation and analysis of these compounds from the sources mentioned. The carotenes, vitamin E, sterols, and squalene were isolated in less than 20 min. The individual vitamin E isomers present in palm oil were also isolated into their respective components, alpha-tocopherol, alpha-tocotrienol, gamma-tocopherol, gamma-tocotrienol, and delta-tocotrienol. Calibration of all the minor components of palm as well as the individual components of palm vitamin E was carried out and was found to be comparable to those analyzed by other established analytical methods.
  9. Looi LM, Cheah PL, Zhao W, Ng MH, Yip CH
    Malays J Pathol, 2006 Dec;28(2):83-6.
    PMID: 18376796 MyJurnal
    Metastasising ability connotes one of the most important life-threatening properties of malignant neoplasms. Recent studies indicate that CD44 proteins, multifunctional cell adhesion molecules which contribute to "homing" of lymphocytes to lymph nodes as well as cell-cell and cell-matrix interactions, are potential markers of tumour progression. However, whether CD44 expression by human tumours contribute to increased metastatic risk remains controversial. In an attempt to clarify its role in breast cancer, we have investigated the correlation between CD44 expression by breast carcinoma and the presence of axillary lymph node metastases. CD44 expression was detected using a standard immunoperoxidase method on formalin-fixed, paraffin-embedded, primary infiltrating ductal breast carcinoma tissues taken from 60 female patients who underwent mastectomy with axillary node clearance. Tumours were graded according to the modified Bloom and Richardson criteria. 62% of patients had histologically-proven lymph node metastasis. 40% of primary cancers exhibited cytoplasmic membrane immunopositivity for CD44. 46% of primary tumours which have metastasied to axillary lymph nodes were CD44 positive whereas 30% of tumours which have not metastasised expressed CD44. CD44 positivity was expressed by 20% of grade 1, 31% grade 2 and 58% grade 3 tumours. Our results suggest that CD44 may have a role in the progression of breast cancer and emphasise the need to investigate its interaction with other mechanisms of cancer advancement.
  10. Looi LM, Ng MH, Cheah PL
    Malays J Pathol, 2007 Jun;29(1):33-5.
    PMID: 19105326 MyJurnal
    The unique ability of tumour cells to proliferate indefinitely is crucial to neoplastic progression as it allows these cells to express the aggressive properties of cancer without the censure of physiological ageing. This is in contrast to normal somatic cells which are subject to a "mitotic clock," a phenomenon that has been linked to telomeric shortening after each round of cell replication, so that eventually the loss of genetic material reaches a critical stage and the cells undergo senescence and cell death. A study was conducted to investigate the role of telomerase, an RNA-containing enzyme that restores the telomere length, in the neoplastic cell immortalization and progression process. Fresh human tissue samples taken from excision specimens received by the Department of Pathology, University of Malaya Medical Centre, were investigated for telomerase activity using a commercial Telomerase PCR-ELISA kit (Boehringer Mannheim). Specimens comprised 33 breast lesions (10 infiltrating breast adenocarcinoma, 13 fibroadenoma and 10 non-neoplastic breast tissue), 27 colonic lesions (17 colonic adenocarcinoma and 10 non-neoplastic colonic mucosa) and 42 cervical lesions (20 cervical carcinoma and 22 non-neoplastic cervical tissues). Telomerase activity was found in 6 (60%) of 10 breast carcinomas, 6 (46%) of 13 fibroadenomas, none of the 10 nonneoplastic breast samples, 3 (17.6%) of 17 colon carcinomas and none of the 10 non-neoplastic colonic mucosal samples, 12 (60%) of 20 cervical carcinoma and 3 (13.6%) of 22 non-neoplastic cervical samples. 5/10 (50%) Stage I, 4/7 (57%) Stage II, 2/2 (100%) Stage III and 1/1 (100%) Stage IV cervical carcinomas showed telomerase activity. These findings support a contributory role for telomerase in tumourigenesis with activation occurring from neoplastic transformation and increasing with tumour progression.
  11. Ng MH, Aminuddin BS, Hamizah S, Lynette C, Mazlyzam AL, Ruszymah BH
    J Tissue Viability, 2009 Nov;18(4):109-16.
    PMID: 19632116 DOI: 10.1016/j.jtv.2009.06.003
    Previous studies suggested telomerase activity as a determinant of cell replicative capacity by delaying cell senescence. This study aimed to evaluate the feasibility of adopting telomerase activity as a selection criterion for in vitro expanded skin cells before autologous transplantation. Fibroblasts and keratinoctyes were derived from the same consenting patients aged 9-69 years, and cultured separately in serum-supplemented and serum-free media, respectively. Telomerase activity of fresh and cultured cells were measured and correlated with cell growth rate, donor age and passage number. The results showed that telomerase activity and cell growth were independent of donor age for both cell types. Telomerase was expressed in freshly digested epidermis and dermis and continued expressing in vitro. Keratinocytes consistently showed 3-12 folds greater telomerase activity than fibroblast both in vivo and in vitro. Conversely, growth rate for fibroblast exceeded that of keratinocyte. Telomerase activity decreased markedly at Passage 6 for keratinocytes and ceased by Passage 3 for fibroblasts. The decrease or cessation of telomerase activity coincided with senescence for keratinocyte but not for fibroblast, implying a telomerase-regulated cell senescence for the former and hence a predictor of replicative capacity for this cell type. Relative telomerase activity for fibroblasts from the younger age group was significantly higher than that from the older age group; 69.7% higher for fresh isolates and 31.1% higher at P0 (p<0.05). No detectable telomerase activity was to be found at later subcultures for both age groups. Similarly for keratinocytes, telomerase activity in the younger age group was significantly higher (p<0.05) compared to that in the older age group; 507.7% at P0, 36.8% at P3 and the difference was no longer significant at P6. In conclusion, the study provided evidence that telomerase sustained the proliferation of keratinocytes but not fibroblasts. Telomerase activity is an important criterion for continued survival and replication of keratinocytes, hence its positive detection before transplantation is desirable. Inferring from our results, the use of keratinocytes from Passage 3 or lesser for construction of skin substitute or cell-based therapy is recommended owing to their sustained telomerase expression.
  12. Looi LM, Cheah PL, Ng MH, Yip CH, Mun KS, Rahman NA
    Asian Pac J Cancer Prev, 2010;11(3):713-6.
    PMID: 21039041
    A study was initiated to explore possible differences in handling telomere attrition in the most common lignant and benign tumours of the breast in Malaysian women. Infiltrating ductal carcinoma (IDC) and fibroadenoma (FA) represented the malignant and benign prototypes respectively. 29 IDC, 28 FA and 22 benign non-lesional control (BNL) breast tissue samples were analysed for telomerase activation using a Telomerase PCR ELISA kit (Boehringer Mannheim). In addition, 23 IDC, 12 FA and 14 BNL were subjected to telomere length determination with a TeloTAGGG Telomere Length Assay Kit (Roche Diagnostic GmbH, Germany), following digestion of genomic DNA by frequently cutting restriction enzymes RsaI and HinfI. Mean telomerase activity in IDC (A450nm=0.3338), but not FA (A450nm=0.0003) was significantly raised (p<0.05) compared with BNL (A450nm=0.0031). Similarly IDC (1.2 kb), but not FA (2.2 kb), showed significant telomere shortening (p<0.05) relative to BNL (2.9 kb). The findings imply that telomere attrition and telomerase activation differ between malignant and benign tumours of the breast and may be important for targeted therapy.
  13. Ude CC, Shamsul BS, Ng MH, Chen HC, Norhamdan MY, Aminuddin BS, et al.
    Tissue Cell, 2012 Jun;44(3):156-63.
    PMID: 22402173 DOI: 10.1016/j.tice.2012.02.001
    Tracking of transplanted cells has become an important procedure in cell therapy. We studied the in vitro dye retention, survival and in vivo tracking of stem cells with PKH26 dye. Sheep BMSCs and ADSCs were labeled with 2, 4 and 8 μmol of PKH26 and monitored for six passages. Labeled BMSCs and ADSCs acquired mean cumulative population doubling of 12.7±0.4 and 14.6±0.5; unlabeled samples had 13.8±0.5 and 15.4±0.6 respectively. Upon staining with 2, 4 and 8 μmol PKH26, BMSCs had retentions of 40.0±5.8, 60.0±2.9 and 95.0±2.9%, while ADSCs had 92.0±1.2, 95.0±1.2 and 98.0±1.2%. ADSCs retentions were significantly higher at 2 and 4 μmol. On dye retention comparison at 8 μmol and 4 μmol for BMSCs and ADSCs; ADSCs were significantly higher at passages 2 and 3. The viability of BMSCs reduced from 94.0±1.2% to 90.0±0.6% and ADSCs from 94.0±1.2% to 52.0±1.2% (p<0.05) after 24h. BMSCs had significant up regulation of the cartilage genes for both the labeled and the unlabeled samples compared to ADSCs (p<0.05). PKH26 fluorescence was detected on the resected portions of the regenerated neo-cartilage. The recommended concentration of PKH26 for ADSCs is 2 μmol and BMSCs is 8 μmol, and they can be tracked up to 49 days.
  14. Chowdhury SR, Ng MH, Hassan NS, Aminuddin BS, Ruszymah BH
    Hum. Cell, 2012 Sep;25(3):69-77.
    PMID: 22968953
    This study was undertaken in order to identify the best culture strategy to expand and osteogenic differentiation of human bone marrow stem cells (hBMSCs) for subsequent bone tissue engineering. In this regard, the experiment was designed to evaluate whether it is feasible to bypass the expansion phase during hBMSCs differentiation towards osteogenic lineages by early induction, if not identification of suitable culture media for enhancement of hBMSCs expansion and osteogenic differentiation. It was found that introduction of osteogenic factors in alpha-minimum essential medium (αMEM) during expansion phase resulted in significant reduction of hBMSCs growth rate and osteogenic gene expressions. In an approach to identify suitable culture media, the growth and differentiation potential of hBMSCs were evaluated in αMEM, F12:DMEM (1:1; FD), and FD with growth factors. It was found that αMEM favors the expansion and osteogenic differentiation of hBMSCs compared to that in FD. However, supplementation of growth factors in FD, only during expansion phase, enhances the hBMSCs growth rate and significantly up-regulates the expression of CBFA-1 (the early markers of osteogenic differentiation) during expansion, and, other osteogenic genes at the end of induction compared to the cells in αMEM and FD. These results suggested that the expansion and differentiation phase of the hBMSCs should be separately and carefully timed. For bone tissue engineering, supplementation of growth factors in FD only during the expansion phase was sufficient to promote hBMSCs expansion and differentiation, and preferably the most efficient culture condition.
  15. Hassan NH, Sulong AF, Ng MH, Htwe O, Idrus RB, Roohi S, et al.
    J Orthop Res, 2012 Oct;30(10):1674-81.
    PMID: 22411691 DOI: 10.1002/jor.22102
    Autologous nerve grafts to bridge nerve gaps have donor site morbidity and possible neuroma formation resulting in development of various methods of bridging nerve gaps without using autologous nerve grafts. We have fabricated an acellular muscle stuffed vein seeded with differentiated mesenchymal stem cells (MSCs) as a substitute for nerve autografts. Human vein and muscle were both decellularized by liquid nitrogen immersion with subsequent hydrolysis in hydrochloric acid. Human MSCs were subjected to a series of treatments with a reducing agent, retinoic acid, and a combination of trophic factors. The differentiated MSCs were seeded on the surface of acellular muscle tissue and then stuffed into the vein. Our study showed that 35-75% of the cells expressed neural markers such as S100b, glial fibrillary acidic protein (GFAP), p75 NGF receptor, and Nestin after differentiation. Histological and ultra structural analyses of muscle stuffed veins showed attachment of cells onto the surface of the acellular muscle and penetration of the cells into the hydrolyzed fraction of muscle fibers. We implanted these muscle stuffed veins into athymic mice and at 8 weeks post-implantation, the acellular muscle tissue had fully degraded and replaced with new matrix produced by the seeded cells. The vein was still intact and no inflammatory reactions were observed proving the biocompatibility and biodegradability of the conduit. In conclusion, we have successfully formed a stable living nerve conduit which may serve as a substitute for autologous nerves.
  16. Seet WT, Manira M, Maarof M, Khairul Anuar K, Chua KH, Ahmad Irfan AW, et al.
    PLoS One, 2012;7(8):e40978.
    PMID: 22927903 DOI: 10.1371/journal.pone.0040978
    Skin plays an important role in defense against infection and other harmful biological agents. Due to its fragile structure, skin can be easily damaged by heat, chemicals, traumatic injuries and diseases. An autologous bilayered human skin equivalent, MyDerm™, was engineered to provide a living skin substitute to treat critical skin loss. However, one of the disadvantages of living skin substitute is its short shelf-life, hence limiting its distribution worldwide. The aim of this study was to evaluate the shelf-life of MyDerm™ through assessment of cell morphology, cell viability, population doubling time and functional gene expression levels before transplantation. Skin samples were digested with 0.6% Collagenase Type I followed by epithelial cells dissociation with TrypLE Select. Dermal fibroblasts and keratinocytes were culture-expanded to obtain sufficient cells for MyDerm™ construction. MyDerm™ was constructed with plasma-fibrin as temporary biomaterial and evaluated at 0, 24, 48 and 72 hours after storage at 4°C for its shelf-life determination. The morphology of skin cells derived from MyDerm™ remained unchanged across storage times. Cells harvested from MyDerm™ after storage appeared in good viability (90.5%±2.7% to 94.9%±1.6%) and had short population doubling time (58.4±8.7 to 76.9±19 hours). The modest drop in cell viability and increased in population doubling time at longer storage duration did not demonstrate a significant difference. Gene expression for CK10, CK14 and COL III were also comparable between different storage times. In conclusion, MyDerm™ can be stored in basal medium at 4°C for at least 72 hours before transplantation without compromising its functionality.
  17. Tan CW, Ng MH, Ohnmar H, Lokanathan Y, Nur-Hidayah H, Roohi SA, et al.
    Indian J Orthop, 2013 Nov;47(6):547-52.
    PMID: 24379458 DOI: 10.4103/0019-5413.121572
    BACKGROUND AND AIM: Synthetic nerve conduits have been sought for repair of nerve defects as the autologous nerve grafts causes donor site morbidity and possess other drawbacks. Many strategies have been investigated to improve nerve regeneration through synthetic nerve guided conduits. Olfactory ensheathing cells (OECs) that share both Schwann cell and astrocytic characteristics have been shown to promote axonal regeneration after transplantation. The present study was driven by the hypothesis that tissue-engineered poly(lactic-co-glycolic acid) (PLGA) seeded with OECs would improve peripheral nerve regeneration in a long sciatic nerve defect.

    MATERIALS AND METHODS: Sciatic nerve gap of 15 mm was created in six adult female Sprague-Dawley rats and implanted with PLGA seeded with OECs. The nerve regeneration was assessed electrophysiologically at 2, 4 and 6 weeks following implantation. Histopathological examination, scanning electron microscopic (SEM) examination and immunohistochemical analysis were performed at the end of the study.

    RESULTS: Nerve conduction studies revealed a significant improvement of nerve conduction velocities whereby the mean nerve conduction velocity increases from 4.2 ΁ 0.4 m/s at week 2 to 27.3 ΁ 5.7 m/s at week 6 post-implantation (P < 0.0001). Histological analysis revealed presence of spindle-shaped cells. Immunohistochemical analysis further demonstrated the expression of S100 protein in both cell nucleus and the cytoplasm in these cells, hence confirming their Schwann-cell-like property. Under SEM, these cells were found to be actively secreting extracellular matrix.

    CONCLUSION: Tissue-engineered PLGA conduit seeded with OECs provided a permissive environment to facilitate nerve regeneration in a small animal model.

  18. Boon CM, Ng MH, Choo YM, Mok SL
    PLoS One, 2013;8(2):e55908.
    PMID: 23409085 DOI: 10.1371/journal.pone.0055908
    Oleic acid has been shown to lower high blood pressure and provide cardiovascular protection. Curiosity arises as to whether super olein (SO), red palm olein (RPO) and palm olein (PO), which have high oleic acid content, are able to prevent the development of hypertension.
  19. Manira M, Khairul Anuar K, Seet WT, Ahmad Irfan AW, Ng MH, Chua KH, et al.
    Cell Tissue Bank, 2014 Mar;15(1):41-9.
    PMID: 23456438 DOI: 10.1007/s10561-013-9368-y
    Animal-derivative free reagents are preferred in skin cell culture for clinical applications. The aim of this study was to compare the performance and effects between animal-derived trypsin and recombinant trypsin for skin cells culture and expansion. Full thickness human skin was digested in 0.6 % collagenase for 6 h to liberate the fibroblasts, followed by treatment with either animal-derived trypsin; Trypsin EDTA (TE) or recombinant trypsin; TrypLE Select (TS) to liberate the keratinocytes. Both keratinocytes and fibroblasts were then culture-expanded until passage 2. Trypsinization for both cell types during culture-expansion was performed using either TE or TS. Total cells yield was determined using a haemocytometer. Expression of collagen type I, collagen type III (Col-III), cytokeratin 10, and cytokeratin 14 genes were quantified via RT-PCR and further confirmed with immunocytochemical staining. The results of our study showed that the total cell yield for both keratinocytes and fibroblasts treated with TE or TS were comparable. RT-PCR showed that expression of skin-specific genes except Col-III was higher in the TS treated group compared to that in the TE group. Expression of proteins specific to the two cell types were confirmed by immunocytochemical staining in both TE and TS groups. In conclusion, the performance of the recombinant trypsin is comparable with the well-established animal-derived trypsin for human skin cell culture expansion in terms of cell yield and expression of specific cellular markers.
  20. Lokanathan Y, Ng MH, Hasan S, Ali A, Mahmod M, Htwe O, et al.
    J Biosci Bioeng, 2014 Aug;118(2):231-4.
    PMID: 24598302 DOI: 10.1016/j.jbiosc.2014.02.002
    We evaluated bridging of 15 mm nerve gap in rat sciatic nerve injury model with muscle-stuffed vein seeded with olfactory ensheathing cells as a substitute for nerve autograft. Neurophysiological recovery, as assessed by electrophysiological analysis was faster in the constructed biological nerve conduit compared to that of autograft.
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