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Correlation of donor age and telomerase activity with in vitro cell growth and replicative potential for dermal fibroblasts and keratinocytes

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.

Matched MeSH terms: Cells, Cultured
Fulltext In-vitro differentiation study on isolated human mesenchymal stem cells

Mok PL, Cheong SK, Leong CF

Malays J Pathol, 2008 Jun;30(1):11-9.
PMID: 19108406 MyJurnal

Mesenchymal stem cells are pluripotent progenitors that could be found in human bone marrow. Mesenchymal stem cells are capable of renewing themselves without differentiation in long-term culture. These cells also have low immunogenicity and can suppress alloreactive T cell responses. In the current study, mesenchymal stem cells isolated and propagated previously from the bone marrow of a megaloblastic anaemia patient were tested for their capabilities to differentiate into adipocytes, chondrocytes and osteoblasts in vitro. The differentiated cells were determined by Oil Red O, Alcian Blue-PAS and Alizarin Red S staining, and reverse transcriptase-polymerase chain reaction to determine the expression of mRNA specific for adipogenesis, chondrogenesis and osteogenesis. The results showed that the fibroblast-like cells were capable of differentiating into adipocytes, chondrocytes and osteoblasts upon chemical induction. The adipocytes, chondrocytes and osteoblasts were stained positively to Oil Red O, Alcian Blue-PAS and Alizarin Red S respectively. The differentiated cells were also found to express mRNA specific for adipogenesis ('peroxisome proliferation-activated receptor gamma2' and lipoprotein lipase), chondrogenesis (collagen type II) and osteogenesis (osteocalcin, osteopontin and alkaline phosphatase). In conclusion, this research has successfully isolated fibroblast-like cells from human bone marrow and these cells demonstrated morphological, cytochemical and immunochemical characteristics similar to mesenchymal stem cells. These cells maintain their proliferative properties and could be differentiated into the mesoderm lineage. The success of this study is vital because mesenchymal stem cells can be used in cellular therapy to regenerate or replace damaged tissues, or as a vehicle for therapeutic gene delivery in the future.

Matched MeSH terms: Cells, Cultured
Derivation of cochlea hair cell for in vitro expansion and characterization

Ibnubaidah MA, Chua KH, Mazita A, Azida ZN, Aminuddin BS, Ruszymah BH, et al.

Med J Malaysia, 2008 Jul;63 Suppl A:115-6.
PMID: 19025012

A potential cure for hearing loss would be to regenerate hair cells by stimulating cells of the damaged inner ear sensory epithelia to proliferate and differentiate into hair cells. Here, we investigated the possibility to isolate, culture-expand and characterize the cells from the cochlea membrane of adult mice. Our results showed that the cultured cells isolated from mouse cochlea membrane were heterogenous in nature. Morphologically there were epithelial like cells, hair cell like, nerve cell like and fibroblastic cells observed in the culture. The cultured cells were immunopositive for specific hair cell markers including Myosin 7a, Calretinin and Espin.

Matched MeSH terms: Cells, Cultured
Ex vivo growth of rabbit bulbar, fornix and palpebral conjunctival epithelia in a serum-free and feeder layer-free culture system

Nizam MH, Ruszymah BH, Chua KH, Ghafar NA, Hamzah JC

Med J Malaysia, 2008 Jul;63 Suppl A:111-2.
PMID: 19025010

This study was conducted to explore the feasibility of culturing conjunctiva epithelial cells in serum-free and feeder layer-free culture system with regard to the cell morphology and immunocytochemistry of the rabbit bulbar, fornix and palpebral conjunctiva epithelia. The results showed that epithelium cells from all the three conjunctiva regions can be cultured in a serum-free and feeder layer-free environment. We obtained highest epithelial growth from fornix region with minimum invasion of fibroblast cells compared to other area. All cultured cells were stained positive for cytokeratin 19 and MUC5AC and negative for cytokeratin 3. These findings suggested that fornix was a better source of cells for the development of tissue engineered conjunctiva for future clinical application.

Matched MeSH terms: Cells, Cultured
Mouse bone marrow mesenchymal stem cells acquire CD45-CD106+ immunophenotype only at later passages

Ooi YY, Ramasamy R, Vidyadaran S

Med J Malaysia, 2008 Jul;63 Suppl A:65-6.
PMID: 19024986

Classically, MSC are identified by a CD45-CD106+ phenotype. In this study, we found that mouse MSC achieve this characteristic phenotype only at later passages. With increasing passages, CD45 (hematopoietic marker) expression shifts to negativity, whereas CD106 (vascular cell adhesion molecule-1) expression becomes increasingly positive. These results demonstrate that MSC cells cultured from mouse bone marrow acquire a classical MSC immunophenotype (CD45-CD106+) in later passages.

Matched MeSH terms: Cells, Cultured
The effect of infection of hatched blastocyst bovine embryos with border disease and bovine viral diarrhea viruses

Mabruk MJ, Sheahan B, Atkins G

Southeast Asian J. Trop. Med. Public Health, 2006 Jan;37(1):113-9.
PMID: 16771222

The effect of infection with teratogenic viruses at early stages of pregnancy is not fully understood. This study aimed to look at the effect of infection with teratogenic viruses such as bovine viral diarrhea virus (BVDV) and border disease virus (BDV), on early stage embryos at the hatched blastocyst stage. BVDV and BDV are known to cross the placenta of infected mothers and lead to congenital defects and death of developing fetuses. This study can be a good model for better understanding the effects of other teratogenic viruses such as Rubella virus in humans.

Matched MeSH terms: Cells, Cultured
Phenotypic expression of collagen type II and collagen type I gene in monolayer culture of human auricular chondrocytes

Nur Adelina AN, Aminuddin BS, Munirah S, Chua KH, Fuzina NH, Saim L, et al.

Med J Malaysia, 2004 May;59 Suppl B:188-9.
PMID: 15468881

Cartilage is regularly needed for reconstructive surgery. Basic research in tissue engineering is necessary to develop its full potential. We presented here the expression profile of type II collagen gene and type I collagen gene in human auricular monolayer culture expansion. Cultured chondrocytes documented a reduction in the expression level of collagen type II gene whilst collagen type I gene was gradually expressed through all the passages. This study demonstrated that human auricular chondrocytes lose its phenotypic expression during monolayer culture expansion. Further studies are required to enhance cartilage specific gene expression, collagen type II throughout the in vitro culture.

Matched MeSH terms: Cells, Cultured
Formation of tissue-engineered human auricular cartilage via tissue engineering technique for future use in ear surgery

Saim L, Aminuddin BS, Munirah S, Chua KH, Izuddin Fahmy A, Fuzina NH, et al.

Med J Malaysia, 2004 May;59 Suppl B:192-3.
PMID: 15468883

To date there is no optimal approach to reconstruct an external ear. However, advances in tissue engineering technologies have indicated that in vitro autologous elastic cartilage might be of great importance in the future treatment of these patients. The aim of this study was to observe monolayer expansion of auricular cartilage and to evaluate engineered cartilage using standard histochemical study.

Matched MeSH terms: Cells, Cultured
Differentiation of stem cells derived from carious teeth into dopaminergic-like cells

Gnanasegaran N, Govindasamy V, Abu Kasim NH

Int Endod J, 2016 Oct;49(10):937-49.
PMID: 26354006 DOI: 10.1111/iej.12545

AIM: To investigate whether dental pulp stem cells from carious teeth (DPSCs-CT) can differentiate into functional dopaminergic-like (DAergic) cells and provide an alternative cell source in regenerative medicine.
METHODOLOGY: Dental pulp stem cells from healthy (DPSCs) and carious teeth (DPSCs-CT) were isolated from young donors. Both cell lines were expanded in identical culture conditions and subsequently differentiated towards DAergic-like cells using pre-defined dopaminergic cocktails. The dopaminergic efficiencies were evaluated both at gene and protein as well as at secretome levels.
RESULTS: The efficiency of DPSCs-CT to differentiate into DAergic-like cells was not equivalent to that of DPSCs. This was further reflected in both gene and protein generation whereby key neuronal markers such as nestin, NURR1 and beta-III-tubulin were expressed significantly lower as compared to differentiated DPSCs (P

Matched MeSH terms: Cells, Cultured
Repetitive cryotherapy attenuates the in vitro and in vivo mononuclear cell activation response

Lindsay A, Othman MI, Prebble H, Davies S, Gieseg SP

Exp Physiol, 2016 07 01;101(7):851-65.
PMID: 27094349 DOI: 10.1113/EP085795

What is the central question of this study? Acute and repetitive cryotherapy are routinely used to accelerate postexercise recovery, although the effect on resident immune cells and repetitive exposure has largely been unexplored and neglected. What is the main finding and its importance? Using blood-derived mononuclear cells and semi-professional mixed martial artists, we show that acute and repetitive cryotherapy reduces the in vitro and in vivo T-cell and monocyte activation response whilst remaining independent of the physical performance of elite athletes. We investigated the effect of repetitive cryotherapy on the in vitro (cold exposure) and in vivo (cold water immersion) activation of blood-derived mononuclear cells following high-intensity exercise. Single and repeated cold exposure (5°C) of a mixed cell culture (T cells and monocytes) was investigated using in vitro tissue culture experimentation for total neopterin production (neopterin plus 7,8-dihydroneopterin). Fourteen elite mixed martial art fighters were also randomly assigned to either a cold water immersion (15 min at 10°C) or passive recovery protocol, which they completed three times per week during a 6 week training camp. Urine was collected and analysed for neopterin and total neopterin three times per week, and perceived soreness, fatigue, physical performance (broad jump, push-ups and pull-ups) and training performance were also assessed. Single and repetitive cold exposure significantly (P

Matched MeSH terms: Cells, Cultured
Efficacy of cocoa pod extract as antiwrinkle gel on human skin surface

Abdul Karim A, Azlan A, Ismail A, Hashim P, Abd Gani SS, Zainudin BH, et al.

J Cosmet Dermatol, 2016 Sep;15(3):283-95.
PMID: 27041391 DOI: 10.1111/jocd.12218

OBJECTIVE: Cocoa pods are abundant waste materials of cocoa plantation, which are usually discarded onto plantation floors. However, due to poor plantation management, the discarded cocoa pods can create suitable breeding ground for Phytophthora palmivora, which is regarded as the causal agent of the black pod disease. On the other hand, cocoa pods potentially contain antioxidant compounds. Antioxidant compounds are related to the protection of skin from wrinkles and can be used as functional cosmetic ingredients. Therefore, in this study, cocoa pods were extracted and to be used as active ingredients for antiwrinkles.
METHODS: The active compounds in cocoa pod extracts (CPE) were screened using liquid chromatography-mass spectrometry (LC-MS). Fibroblast cells were used to determine the effective concentration of CPE to maintain the viability for at least 50% of the cells (EC50 ). The gel was tested by 12 panelists to determine the efficacy of CPE in gel form using Visioscan to reduce skin wrinkles and improve skin condition.
RESULTS: CPE was detected to contain malic acid, procyanidin B1, rosmarinic acid, procyanidin C1, apigenin, and ellagic acid, all of which may contribute to functional cosmetic properties of CPE. The EC50 value of cocoa pod extracts was used to calculate the amount of CPE to be incorporated into gel so that the formulated product could reach an effective concentration of extract while being nonintoxicant to the skin cell. The results showed that CPE is potential ingredient to reduce wrinkles. Skin wrinkles reduced at 6.38 ± 1.23% with the application of the CPE gel within 3 weeks and significantly improved further (12.39 ± 1.59%) after 5 weeks. The skin hydration increased (3.181 ± 1.06%) after 3 weeks of the CPE gel application.
CONCLUSION: Flavonoid compounds in CPE contributed to the functional cosmetic properties of CPE. The CPE which is nontoxic to skin cells help to reduce wrinkles on skin after 3 weeks of application. CPE can be used as the active ingredients in antiwrinkle products, and prolonged application may result in significant visual changes to the naked eyes.

Matched MeSH terms: Cells, Cultured
Fulltext Characterization of Nipah virus infection in a model of human airway epithelial cells cultured at an air-liquid interface

Escaffre O, Borisevich V, Vergara LA, Wen JW, Long D, Rockx B

J Gen Virol, 2016 05;97(5):1077-1086.
PMID: 26932515 DOI: 10.1099/jgv.0.000441

Nipah virus (NiV) is an emerging paramyxovirus that can cause lethal respiratory illness in humans. No vaccine/therapeutic is currently licensed for humans. Human-to-human transmission was previously reported during outbreaks and NiV could be isolated from respiratory secretions, but the proportion of cases in Malaysia exhibiting respiratory symptoms was significantly lower than that in Bangladesh. Previously, we showed that primary human basal respiratory epithelial cells are susceptible to both NiV-Malaysia (M) and -Bangladesh (B) strains causing robust pro-inflammatory responses. However, the cells of the human respiratory epithelium that NiV targets are unknown and their role in NiV transmission and NiV-related lung pathogenesis is still poorly understood. Here, we characterized NiV infection of the human respiratory epithelium using a model of the human tracheal/bronchial (B-ALI) and small airway (S-ALI) epithelium cultured at an air-liquid interface. We show that NiV-M and NiV-B infect ciliated and secretory cells in B/S-ALI, and that infection of S-ALI, but not B-ALI, results in disruption of the epithelium integrity and host responses recruiting human immune cells. Interestingly, NiV-B replicated more efficiently in B-ALI than did NiV-M. These results suggest that the human tracheal/bronchial epithelium is favourable to NiV replication and shedding, while inducing a limited host response. Our data suggest that the small airways epithelium is prone to inflammation and lesions as well as constituting a point of virus entry into the pulmonary vasculature. The use of relevant models of the human respiratory tract, such as B/S-ALI, is critical for understanding NiV-related lung pathogenesis and identifying the underlying mechanisms allowing human-to-human transmission.

Matched MeSH terms: Cells, Cultured
Fulltext In Vitro Analysis of Metabolites Secreted during Infection of Lung Epithelial Cells by Cryptococcus neoformans

Liew KL, Jee JM, Yap I, Yong PV

PLoS One, 2016;11(4):e0153356.
PMID: 27054608 DOI: 10.1371/journal.pone.0153356

Cryptococcus neoformans is an encapsulated basidiomycetous yeast commonly associated with pigeon droppings and soil. The opportunistic pathogen infects humans through the respiratory system and the metabolic implications of C. neoformans infection have yet to be explored. Studying the metabolic profile associated with the infection could lead to the identification of important metabolites associated with pulmonary infection. Therefore, the aim of the study was to simulate cryptococcal infection at the primary site of infection, the lungs, and to identify the metabolic profile and important metabolites associated with the infection at low and high multiplicity of infections (MOI). The culture supernatant of lung epithelial cells infected with C. neoformans at MOI of 10 and 100 over a period of 18 hours were analysed using gas chromatography mass spectrometry. The metabolic profiles obtained were further analysed using multivariate analysis and the pathway analysis tool, MetaboAnalyst 2.0. Based on the results from the multivariate analyses, ten metabolites were selected as the discriminatory metabolites that were important in both the infection conditions. The pathways affected during early C. neoformans infection of lung epithelial cells were mainly the central carbon metabolism and biosynthesis of amino acids. Infection at a higher MOI led to a perturbance in the β-alanine metabolism and an increase in the secretion of pantothenic acid into the growth media. Pantothenic acid production during yeast infection has not been documented and the β-alanine metabolism as well as the pantothenate and CoA biosynthesis pathways may represent underlying metabolic pathways associated with disease progression. Our study suggested that β-alanine metabolism and the pantothenate and CoA biosynthesis pathways might be the important pathways associated with cryptococcal infection.

Matched MeSH terms: Tumor Cells, Cultured
Three dimensional alginate-fucoidan composite hydrogel augments the chondrogenic differentiation of mesenchymal stromal cells

Karunanithi P, Murali MR, Samuel S, Raghavendran HRB, Abbas AA, Kamarul T

Carbohydr Polym, 2016 08 20;147:294-303.
PMID: 27178935 DOI: 10.1016/j.carbpol.2016.03.102

Presence of sulfated polysaccharides like heparan sulphate has often been implicated in the regulation of chondrogenesis. However, recently there has been a plethora of interest in the use of non-animal extracted analogs of heparan sulphate. Here we remodeled alginate (1.5%) by incorporating fucoidan (0.5%), a natural sulphated polysaccharide extracted from seaweeds to form a composite hydrogel (Al-Fu), capable of enhancing chondrogenesis of human mesenchymal stromal cells (hMSCs). We confirmed the efficiency of fucoidan incorporation by FTIR and EDX analysis. Further, its ability to support hMSC attachment and chondrogenic differentiation was confirmed by SEM, biochemical glycosaminoglycan quantification, real-time quantitative PCR and immunocytochemical analyses of chondrogenic markers Sox-9, Collagen II, Aggrecan and COMP. Effect of Al-Fu hydrogel on hMSC hypertrophy was also confirmed by the downregulation of hypertrophic genes Collagen X and Runx2. This composite scaffold can hence be used as a cartilage biomimetic biomaterial to drive hMSC chondrogenesis and for other cartilage repair based therapies.

Matched MeSH terms: Cells, Cultured
Fulltext Effect of Growth Factor Supplementation on the Hair Cell Specific Markers of Cells Harvested from Basilar Membrane

Ubaidah MA, Chua KH, Ami M, Zainal A, Saim A, Saim L, et al.

J Int Adv Otol, 2015 Apr;11(1):23-9.
PMID: 26223713 DOI: 10.5152/iao.2015.539

Loss of auditory hair cells is a major cause of deafness. The presence of auditory progenitor cells in the inner ear raises the hope for mammalian inner ear cell regeneration. In this study, we aimed to investigate the effect of growth factor supplementations, namely a combination of epidermal growth factor (EGF), insulin-like growth factor (IGF), and beta (β)-fibroblast growth factor (βFGF), on the expression of hair cell-specific markers by cells harvested from the cochlear membrane. This would provide an insight into the capability of these cells to differentiate into hair cells.

Matched MeSH terms: Cells, Cultured
Fulltext Control of Polyamine Biosynthesis by Antizyme Inhibitor 1 Is Important for Transcriptional Regulation of Arginine Vasopressin in the Male Rat Hypothalamus

Greenwood MP, Greenwood M, Paton JF, Murphy D

Endocrinology, 2015 Aug;156(8):2905-17.
PMID: 25961839 DOI: 10.1210/en.2015-1074

The polyamines spermidine and spermine are small cations present in all living cells. In the brain, these cations are particularly abundant in the neurons of the paraventricular (PVN) and supraoptic nuclei (SON) of the hypothalamus, which synthesize the neuropeptide hormones arginine vasopressin (AVP) and oxytocin. We recently reported increased mRNA expression of antizyme inhibitor 1 (Azin1), an important regulator of polyamine synthesis, in rat SON and PVN as a consequence of 3 days of dehydration. Here we show that AZIN1 protein is highly expressed in both AVP- and oxytocin-positive magnocellular neurons of the SON and PVN together with antizyme 1 (AZ1), ornithine decarboxylase, and polyamines. Azin1 mRNA expression increased in the SON and PVN as a consequence of dehydration, salt loading, and acute hypertonic stress. In organotypic hypothalamic cultures, addition of the irreversible ornithine decarboxylase inhibitor DL-2-(difluoromethyl)-ornithine hydrochloride significantly increased the abundance of heteronuclear AVP but not heteronuclear oxytocin. To identify the function of Azin1 in vivo, lentiviral vectors that either overexpress or knock down Azin1 were stereotaxically delivered into the SON and/or PVN. Azin1 short hairpin RNA delivery resulted in decreased plasma osmolality and had a significant effect on food intake. The expression of AVP mRNA was also significantly increased in the SON by Azin1 short hairpin RNA. In contrast, Azin1 overexpression in the SON decreased AVP mRNA expression. We have therefore identified AZIN1, and hence by inference, polyamines as novel regulators of the expression of the AVP gene.

Matched MeSH terms: Cells, Cultured
Tocotrienol-rich fraction prevents cellular aging by modulating cell proliferation signaling pathways

Khor SC, Mohd Yusof YA, Wan Ngah WZ, Makpol S

Clin Ter, 2015;166(2):e81-90.
PMID: 25945449 DOI: 10.7417/CT.2015.1825

BACKGROUND AND OBJECTIVE: Vitamin E has been suggested as nutritional intervention for the prevention of degenerative and age-related diseases. In this study, we aimed to elucidate the underlying mechanism of tocotrienol-rich fraction (TRF) in delaying cellular aging by targeting the proliferation signaling pathways in human diploid fibroblasts (HDFs).
MATERIALS AND METHODS: Tocotrienol-rich fraction was used to treat different stages of cellular aging of primary human diploid fibroblasts viz. young (passage 6), pre-senescent (passage 15) and senescent (passage 30). Several selected targets involved in the downstream of PI3K/AKT and RAF/MEK/ERK pathways were compared in total RNA and protein.
RESULTS: Different transcriptional profiles were observed in young, pre-senescent and senescent HDFs, in which cellular aging increased AKT, FOXO3, CDKN1A and RSK1 mRNA expression level, but decreased ELK1, FOS and SIRT1 mRNA expression level. With tocotrienol-rich fraction treatment, gene expression of AKT, FOXO3, ERK and RSK1 mRNA was decreased in senescent cells, but not in young cells. The three down-regulated mRNA in cellular aging, ELK1, FOS and SIRT1, were increased with tocotrienol-rich fraction treatment. Expression of FOXO3 and P21Cip1 proteins showed up-regulation in senescent cells but tocotrienol-rich fraction only decreased P21Cip1 protein expression in senescent cells.
CONCLUSIONS: Tocotrienol-rich fraction exerts gene modulating properties that might be responsible in promoting cell cycle progression during cellular aging.

Matched MeSH terms: Cells, Cultured
Fulltext Suppression of Human T Cell Proliferation Mediated by the Cathepsin B Inhibitor, z-FA-FMK Is Due to Oxidative Stress

Rajah T, Chow SC

PLoS One, 2015;10(4):e0123711.
PMID: 25915766 DOI: 10.1371/journal.pone.0123711

The cathepsin B inhibitor, benzyloxycarbonyl-phenylalanine-alanine-fluoromethyl ketone (z-FA-FMK) readily inhibits anti-CD3-induced human T cell proliferation, whereas the analogue benzyloxycarbonyl-phenylalanine-alanine-diazomethyl ketone (z-FA-DMK) had no effect. In contrast, benzyloxycarbonyl-phenylalanine-alanine-chloromethyl ketone (z-FA-CMK) was toxic. The inhibition of T cell proliferation mediated by z-FA-FMK requires not only the FMK moiety, but also the benzyloxycarbonyl group at the N-terminal, suggesting some degree of specificity in z-FA-FMK-induced inhibition of primary T cell proliferation. We showed that z-FA-FMK treatment leads to a decrease in intracellular glutathione (GSH) with a concomitant increase in reactive oxygen species (ROS) levels in activated T cells. The inhibition of anti-CD3-induced T cell proliferation mediated by z-FA-FMK was abolished by the presence of low molecular weight thiols such as GSH, N-acetylcysteine (NAC) and L-cysteine, whereas D-cysteine which cannot be metabolised to GSH has no effect. The inhibition of anti-CD3-induced up-regulation of CD25 and CD69 expression mediated by z-FA-FMK was also attenuated in the presence of exogenous GSH. Similar to cell proliferation, GSH, NAC and L-cysteine but not D-cysteine, completely restored the processing of caspase-8 and caspase-3 to their respective subunits in z-FA-FMK-treated activated T cells. Our collective results demonstrated that the inhibition of T cell activation and proliferation mediated by z-FA-FMK is due to oxidative stress via the depletion of GSH.

Matched MeSH terms: Cells, Cultured
An evaluation of accelerated Portland cement as a restorative material

Abdullah D, Ford TR, Papaioannou S, Nicholson J, McDonald F

Biomaterials, 2002 Oct;23(19):4001-10.
PMID: 12162333

Biocompatibility of two variants of accelerated Portland cement (APC) were investigated in vitro by observing the cytomorphology of SaOS-2 osteosarcoma cells in the presence of test materials and the effect of these materials on the expression of markers of bone remodelling. Glass ionomer cement (GIC), mineral trioxide aggregate (MTA) and unmodified Portland cement (RC) were used for comparison. A direct contact assay was undertaken in four samples of each test material, collected at 12, 24, 48 and 72 h. Cell morphology was observed using scanning electron microscopy (SEM) and scored. Culture media were collected for cytokine quantification using enzyme-linked immunosorbent assay (ELISA). On SEM evaluation, healthy SaOS-2 cells were found adhering onto the surfaces of APC variant, RC and MTA. In contrast, rounded and dying cells were observed on GIC. Using ELISA, levels of interleukin (IL)-1beta, IL-6, IL-18 and OC were significantly higher in APC variants compared with controls and GIC (p<0.01), but these levels of cytokines were not statistically significant compared with MTA. The results of this study provide evidence that both APC variants are non-toxic and may have potential to promote bone healing. Further development of APC is indicated to produce a viable dental restorative material and possibly a material for orthopaedic

Matched MeSH terms: Tumor Cells, Cultured
Fulltext Recovery of poliovirus from cut surface of stored fresh papaya fruit

Lee ASC, Yap KL

Southeast Asian J. Trop. Med. Public Health, 1999 Jun;30(2):280-3.
PMID: 10774695

Poliovirus kept on the cut surfaces of fully ripe papaya cubes placed in an ice box showed a sharp and significant reduction in the recovery of infectious virus about 15 minutes after exposure. Thereafter, a very gradual decrease ensued and infectious residual virus was detected up to the end of the 6-hour exposure period. Papaya cubes washed or kept overnight before virus inoculation, and from less ripe fruits produced a similar survival pattern. A very small proportion of the inoculum was recovered from the mashed content of the inoculated papaya cubes thus suggesting that most of the non-recovered virus particles were inactivated. The results suggest that the importance of poliovirus-contaminated cut papayas as a transmission vehicle for the virus is greatly reduced by the rapid decline in the infectivity of a large proportion of the virus soon after contamination. Nevertheless, the potential to transmit remains as a small residual pool of infectious poliovirus is able to survive for a relatively long period.

Matched MeSH terms: Cells, Cultured

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