MyMedR

Displaying publications 261 - 280 of 412 in total

Abstract:

Sort:

Purification of human adipose-derived stem cells from fat tissues using PLGA/silk screen hybrid membranes

Chen DC, Chen LY, Ling QD, Wu MH, Wang CT, Suresh Kumar S, et al.

Biomaterials, 2014 May;35(14):4278-87.
PMID: 24565521 DOI: 10.1016/j.biomaterials.2014.02.004

The purification of human adipose-derived stem cells (hADSCs) from human adipose tissue cells (stromal vascular fraction) was investigated using membrane filtration through poly(lactide-co-glycolic acid)/silk screen hybrid membranes. Membrane filtration methods are attractive in regenerative medicine because they reduce the time required to purify hADSCs (i.e., less than 30 min) compared with conventional culture methods, which require 5-12 days. hADSCs expressing the mesenchymal stem cell markers CD44, CD73, and CD90 were concentrated in the permeation solution from the hybrid membranes. Expression of the surface markers CD44, CD73, and CD99 on the cells in the permeation solution from the hybrid membranes, which were obtained using 18 mL of feed solution containing 50 × 10⁴ cells, was statistically significantly higher than that of the primary adipose tissue cells, indicating that the hADSCs can be purified in the permeation solution by the membrane filtration method. Cells expressing the stem cell-associated marker CD34 could be successfully isolated in the permeation solution, whereas CD34⁺ cells could not be purified by the conventional culture method. The hADSCs in the permeation solution demonstrated a superior capacity for osteogenic differentiation based on their alkali phosphatase activity, their osterix gene expression, and the results of mineralization analysis by Alizarin Red S and von Kossa staining compared with the cells from the suspension of human adipose tissue. These results suggest that the hADSCs capable of osteogenic differentiation preferentially permeate through the hybrid membranes.

Matched MeSH terms: Stem Cells/cytology*; Stem Cells/drug effects; Stem Cells/metabolism
Fulltext Tualang honey improves human corneal epithelial progenitor cell migration and cellular resistance to oxidative stress in vitro

Tan JJ, Azmi SM, Yong YK, Cheah HL, Lim V, Sandai D, et al.

PLoS One, 2014;9(5):e96800.
PMID: 24802273 DOI: 10.1371/journal.pone.0096800

Stem cells with enhanced resistance to oxidative stress after in vitro expansion have been shown to have improved engraftment and regenerative capacities. Such cells can be generated by preconditioning them with exposure to an antioxidant. In this study we evaluated the effects of Tualang honey (TH), an antioxidant-containing honey, on human corneal epithelial progenitor (HCEP) cells in culture. Cytotoxicity, gene expression, migration, and cellular resistance to oxidative stress were evaluated. Immunofluorescence staining revealed that HCEP cells were holoclonal and expressed epithelial stem cell marker p63 without corneal cytokeratin 3. Cell viability remained unchanged after cells were cultured with 0.004, 0.04, and 0.4% TH in the medium, but it was significantly reduced when the concentration was increased to 3.33%. Cell migration, tested using scratch migration assay, was significantly enhanced when cells were cultured with TH at 0.04% and 0.4%. We also found that TH has hydrogen peroxide (H2O2) scavenging ability, although a trace level of H2O2 was detected in the honey in its native form. Preconditioning HCEP cells with 0.4% TH for 48 h showed better survival following H2O2-induced oxidative stress at 50 µM than untreated group, with a significantly lower number of dead cells (15.3 ± 0.4%) were observed compared to the untreated population (20.5 ± 0.9%, p<0.01). Both TH and ascorbic acid improved HCEP viability following induction of 100 µM H2O2, but the benefit was greater with TH treatment than with ascorbic acid. However, no significant advantage was demonstrated using 5-hydroxymethyl-2-furancarboxaldehyde, a compound that was found abundant in TH using GC/MS analysis. This suggests that the cellular anti-oxidative capacity in HCEP cells was augmented by native TH and was attributed to its antioxidant properties. In conclusion, TH possesses antioxidant properties and can improve cell migration and cellular resistance to oxidative stress in HCEP cells in vitro.

Matched MeSH terms: Stem Cells/cytology; Stem Cells/drug effects*; Stem Cells/metabolism
Fulltext Differentiation of dental pulp stem cells into neuron-like cells in serum-free medium

Zainal Ariffin SH, Kermani S, Zainol Abidin IZ, Megat Abdul Wahab R, Yamamoto Z, Senafi S, et al.

Stem Cells Int, 2013;2013:250740.
PMID: 24348580 DOI: 10.1155/2013/250740

Dental pulp tissue contains dental pulp stem cells (DPSCs). Dental pulp cells (also known as dental pulp-derived mesenchymal stem cells) are capable of differentiating into multilineage cells including neuron-like cells. The aim of this study was to examine the capability of DPSCs to differentiate into neuron-like cells without using any reagents or growth factors. DPSCs were isolated from teeth extracted from 6- to 8-week-old mice and maintained in complete medium. The cells from the fourth passage were induced to differentiate by culturing in medium without serum or growth factors. RT-PCR molecular analysis showed characteristics of Cd146(+) , Cd166(+) , and Cd31(-) in DPSCs, indicating that these cells are mesenchymal stem cells rather than hematopoietic stem cells. After 5 days of neuronal differentiation, the cells showed neuron-like morphological changes and expressed MAP2 protein. The activation of Nestin was observed at low level prior to differentiation and increased after 5 days of culture in differentiation medium, whereas Tub3 was activated only after 5 days of neuronal differentiation. The proliferation of the differentiated cells decreased in comparison to that of the control cells. Dental pulp stem cells are induced to differentiate into neuron-like cells when cultured in serum- and growth factor-free medium.

Matched MeSH terms: Hematopoietic Stem Cells
Fulltext Pro-angiogenic potential of human chorion-derived stem cells: in vitro and in vivo evaluation

Fariha MM, Chua KH, Tan GC, Lim YH, Hayati AR

J Cell Mol Med, 2013 May;17(5):681-92.
PMID: 23551495 DOI: 10.1111/jcmm.12051

Human chorion-derived stem cells (hCDSC) were previously shown to demonstrate multipotent properties with promising angiogenic characteristics in monolayer-cell culture system. In our study, we investigated the angiogenic capability of hCDSC in 3-dimensional (3D) in vitro and in vivo angiogenic models for the purpose of future application in the treatment of ischaemic diseases. Human CDSC were evaluated for angiogenic and endogenic genes expressions by quantitative PCR. Growth factors secretions were quantified using ELISA. In vitro and in vivo vascular formations were evaluated by histological analysis and confocal microscopic imaging. PECAM-1(+) and vWF(+) vascular-like structures were observed in both in vitro and in vivo angiogenesis models. High secretions of VEGF and bFGF by hCDSC with increased expressions of angiogenic and endogenic genes suggested the possible angiogenic promoting mechanisms by hCDSC. The cooperation of hCDSC with HUVECS to generate vessel-like structures in our systems is an indication that there will be positive interactions of hCDSC with existing endothelial cells when injected into ischaemic tissues. Hence, hCDSC is suggested as the novel approach in the future treatment of ischaemic diseases.

Matched MeSH terms: Stem Cells/cytology*; Stem Cells/drug effects; Stem Cells/metabolism*
Fulltext Cytotoxicity of accelerated white MTA and Malaysian white Portland cement on stem cells from human exfoliated deciduous teeth (SHED): An in vitro study

Ong RM, Luddin N, Ahmed HM, Omar NS

Singapore Dent J, 2012 Dec;33(1):19-23.
PMID: 23739319 DOI: 10.1016/j.sdj.2012.11.001

The aim of this study was to compare the cytotoxicity of accelerated-set white MTA (AWMTA) and accelerated-set Malaysian white PC (AMWPC) on stem cells from human exfoliated deciduous teeth (SHED). The test materials were introduced into paraffin wax moulds after mixing with calcium chloride dihydrate and sterile distilled water. Subsequently, the set cement specimens were sterilized, incubated in a prepared Dulbecco's modified Eagle medium (DMEM) for seven days. The biomarker CD166 was used for characterization of SHED using flow cytometry. The material extracts were diluted at five different concentrations and incubated for 72h with SHED. The cell viability was evaluated using Dimethylthiazol diphenyltetrazolium bromide (MTT) assay, and the data was analysed using Mann-Whitney test (P<0.05). The results showed that AWMTA revealed significantly greater cell viability at 25 and 12.5mg/ml concentrations (P<0.05). Concomitantly, AMWPC exhibited greater cell viability at concentrations <12.5mg/ml and the results were significant at 1.563mg/ml (P<0.05). Both materials demonstrated moderate cytotoxicity at 25mg/ml and slight cytotoxicity at 6.25 and 3.125mg/ml. At 1.563mg/ml, no cytotoxic activity was merely observed with AMWPC. In conclusion, AMWPC exhibited favourable and comparable cell viability to that of AWMTA, and has the potential to be used as an alternative and less costly material in dental applications.

Matched MeSH terms: Stem Cells
The RUNX complex: reaching beyond haematopoiesis into immunity

Voon DC, Hor YT, Ito Y

Immunology, 2015 Dec;146(4):523-36.
PMID: 26399680 DOI: 10.1111/imm.12535

Among their diverse roles as transcriptional regulators during development and cell fate specification, the RUNX transcription factors are best known for the parts they play in haematopoiesis. RUNX proteins are expressed throughout all haematopoietic lineages, being necessary for the emergence of the first haematopoietic stem cells to their terminal differentiation. Although much progress has been made since their discoveries almost two decades ago, current appreciation of RUNX in haematopoiesis is largely grounded in their lineage-specifying roles. In contrast, the importance of RUNX to immunity has been mostly obscured for historic, technical and conceptual reasons. However, this paradigm is likely to shift over time, as a primary purpose of haematopoiesis is to resource the immune system. Furthermore, recent evidence suggests a role for RUNX in the innate immunity of non-haematopoietic cells. This review takes a haematopoiesis-centric approach to collate what is known of RUNX's contribution to the overall mammalian immune system and discuss their growing prominence in areas such as autoimmunity, inflammatory diseases and mucosal immunity.

Matched MeSH terms: Hematopoietic Stem Cells
Fulltext Misfolded N-CoR is Linked to the Ectopic Reactivation of CD34/Flt3-Based Stem-Cell Phenotype in Promyelocytic and Monocytic Acute Myeloid Leukemia

Nin DS, Li F, Visvanathan S, Khan M

Front Oncol, 2015;5:210.
PMID: 26500885 DOI: 10.3389/fonc.2015.00210

Nuclear receptor co-repressor (N-CoR) is the key component of generic co-repressor complex essential for the transcriptional control of genes involved in cellular hemostasis. We have recently reported that N-CoR actively represses Flt3, a key factor of hematopoietic stem cells (HSC) self-renewal and growth, and that de-repression of Flt3 by the misfolded N-CoR plays an important role in the pathogenesis of promyelocytic and monocytic acute myeloid leukemia (AML). The leukemic cells derived from the promyelocytic and monocytic AML are distinctly characterized by the ectopic reactivation of stem cell phenotypes in relatively committed myeloid compartment. However, the molecular mechanism underlying this phenomenon is not known. Here, we report that N-CoR function is essential for the commitment of primitive hematopoietic cells to the cells of myeloid lineage and that loss of N-CoR function due to misfolding is linked to the ectopic reactivation of generic stem cell phenotypes in promyelocytic and monocytic AML. Analysis of N-CoR and Flt3 transcripts in mouse hematopoietic cells revealed a positive correlation between N-CoR level and the commitment of myeloid cells and an inverse correlation between N-CoR and Flt3 levels in primitive as well as committed myeloid cells. Enforced N-CoR expression in mouse HSCs inhibited their growth and self-renewal potentials and promoted maturation toward cells of myeloid lineage, suggesting a role of N-CoR in the commitment of cells of myeloid lineage. In contrast to AML cells with natively folded N-CoR, primary and secondary promyelocytic and monocytic AML cells harboring the misfolded N-CoR were highly positive for Flt3 and myeloid antigen-based HSC marker CD34. Genetic and therapeutic restoration of N-CoR conformation significantly down-regulated the CD34 levels in monocytic AML cells, suggesting an important role of N-CoR in the suppression of CD34-based HSC phenotypes. These findings collectively suggest that N-CoR is crucial for the commitment of primitive hematopoietic cells to cells of myeloid lineage and that misfolded N-CoR may contribute to transformation of committed myeloid cells through the ectopic reactivation of Flt3/CD34-based stem cell phenotypes in promyelocytic and monocytic AML. Moreover, these findings provide novel mechanistic insights into the formation of leukemic stem cells in subsets of AML and identify the misfolded N-CoR as a subtype-specific biomarker of AML.

Matched MeSH terms: Hematopoietic Stem Cells
A randomized double blind control trial comparing filgrastim and pegfilgrastim in cyclophosphamide peripheral blood hematopoietic stem cell mobilization

Kuan JW, Su AT, Wong SP, Sim XY, Toh SG, Ong TC, et al.

Transfus Apher Sci, 2015 Oct;53(2):196-204.
PMID: 25910537 DOI: 10.1016/j.transci.2015.03.017

There are few randomized trials comparing filgrastim and pegfilgrastim in peripheral blood stem cell mobilization (PBSCM). None of the trials studied the effects of the timing of pegfilgrastim administration on the outcomes of mobilization. We conducted a randomized triple blind control trial comparing the outcomes of filgrastim 5 µg/kg daily from day 3 onwards, 'early' pegfilgrastim 6 mg on day 3 and 'delayed' pegfilgrastim 6 mg on day 7 in cyclophosphamide PBSCM in patients with no previous history of mobilization. Peripheral blood (PB) CD34+ cell count was checked on day 8 and day 11 onward. Apheresis was started when PB CD34+ ≥ 10/µl from day 11 onward. The primary outcome was the successful mobilization rate, defined as cumulative collection of ≥2 × 10(6)/kg CD34+ cells in three or less apheresis. The secondary outcomes were the day of neutrophil and platelet engraftment post transplantation. There were 156 patients randomized and 134 patients' data analyzed. Pegfilgrastim 6 mg day 7 produced highest percentage of successful mobilization, 34 out of 48 (70.8%) analyzed patients, followed by daily filgrastim, 28 out of 44 (63.6%) and day 3 pegfilgrastim, 20 out of 42 (47.6%) (p = 0.075). Pegfilgrastim day 7 and daily filgrastim reported 1.48 (p = 0.014) and 1.49 (p = 0.013) times higher successful mobilization rate respectively as compared to pegfilgrastim day 3 after adjusting for disease, gender and exposure to myelotoxic agent. Multiple myeloma patients were three times more likely to achieve successful mobilization as compared to acute leukemia or lymphoma patients. Pegfilgrastim avoided the overshoot of white cells compared to filgrastim. There was no difference in the duration of both white cells and platelet recovery post transplantation between the three interventional arms.

Matched MeSH terms: Peripheral Blood Stem Cells
Fulltext Comparative evaluation of apical bacterial extrusion following root canal instrumentation using different endodontic file systems: An in vitro study

Vankayala B, Anantula K, Saladi H, Gudugunta L, Basavarajaiah JM, Yadav SS

J Conserv Dent, 2020 08 20;22(6):559-563.
PMID: 33088065 DOI: 10.4103/JCD.JCD_221_19

Aim: This study aims to evaluate the amount of apical extrusion of bacteria during root canal instrumentation using K3XF, Protaper Gold, Edge taper platinum, and Hyflex CM Rotary systems.
Materials and Methods: Sixty freshly extracted maxillary incisors teeth collected in saline. Access cavity prepared and canals were made free of bacterial and pulp. The teeth were mounted on the bacteria collecting apparatus. Root canals were contaminated with the Fusobacterium Nucleatum (ATCC25586) and dried at 37°C for 24 h. In Group 1 (Control group): No instrumentation was done and biomechanical preparation done in all other groups with Group 2: Hand K-files, Group 3: Protaper gold, Group 4: K3XF, Group 5: Edge taper platinum, and Group 6: Hyflex CM rotary file systems. Then, the extrude was collected, and it is incubated in Mueller-Hinton agar for 24 h and the number of colony forming units were counted and statistical comparison was done using Kruskal-Wallis test and Mann-Whitney U test.
Results: Hand K-files extruded more bacteria when compared to other four rotary systems, K3XF file system extruded least number of bacteria.
Conclusion: All instrumentation techniques extruded intracanal bacteria apically. However, engine-driven nickel-titanium instruments extruded less bacteria than the manual technique. The K3XF rotary file system comparatively extruded less bacteria than other rotary file systems.

Matched MeSH terms: Stem Cells
Fulltext Massive Tibial Bone Regeneration with Autologous Peripheral Blood Stem Cells using Ilizarov Bone Transport: A Case Report

Saw KY, Gill R, Low TC

Malays Orthop J, 2020 Nov;14(3):166-169.
PMID: 33403079 DOI: 10.5704/MOJ.2011.026

This is a case report of a Gustilo-Anderson Type IIIB comminuted open right tibial fracture with massive bone loss, complicated by methicillin-resistant Staphylococus aureus (MRSA) infection. Non-viable and contaminated bony fragments were removed and infected bone resected. Soft tissue coverage and antibiotics were effective against the MRSA infection. A unifocal bone transport with the Ilizarov method regenerated 13cm of the missing tibia. Autologous peripheral blood stem cells (PBSC) injections into the osteogenesis site boosted bone regeneration and consolidation with a shortened Bone Healing index (BHI) of 23 days/cm.

Matched MeSH terms: Peripheral Blood Stem Cells
Fulltext In vitro and in vivo anticandidal activities of alginate-enclosed chitosan-calcium phosphate-loaded Fe-bovine lactoferrin nanocapsules

Leng KM, Vijayarathna S, Jothy SL, Sasidharan S, Kanwar JR

Future Sci OA, 2018 Feb;4(2):FSO257.
PMID: 29379633 DOI: 10.4155/fsoa-2017-0085

Aim: To study the in vitro and in vivo anticandidal activity of nanocapsulated bovine lactoferrin.
Materials & methods: In vitro and in vivo antimicrobial activities were conducted to study the anticandidal activities of nanocapsules (NCs).
Results: The NCs showed good anticandidal activities. The disruption of cell wall and cell membrane was noted via microscopy studies. The NCs changed the normal growth profile of Candida albicans. NCs reduced the colony forming unit in kidney and blood samples. Histopathological examination showed better cell structure and coordination compared with untreated mice kidney. NCs also enhanced the natural killing properties of C. albicans by epithelial cells.
Conclusion: NCs have effective anticandidal properties and have the potential as a therapeutic agent against candidiasis.

Matched MeSH terms: Stem Cells
Fulltext Mesenchymal Stem Cell-Based Therapies against Podocyte Damage in Diabetic Nephropathy

Khalilpourfarshbafi M, Hajiaghaalipour F, Selvarajan KK, Adam A

Tissue Eng Regen Med, 2017 Jun;14(3):201-210.
PMID: 30603477 DOI: 10.1007/s13770-017-0026-5

Injury to podocytes is an early event in diabetic nephropathy leading to proteinuria with possible progression to end-stage renal failure. The podocytes are unique and highly specialized cells that cover the outer layer of kidney ultra-filtration barrier and play an important role in glomerular function. In the past few decades, adult stem cells, such as mesenchymal stem cells (MSCs) with a regenerative and differentiative capacity have been extensively used in cell-based therapies. In addition to their capability for regeneration and differentiation, MSCs contributes to their milieu by paracrine action of a series of growth factors via antiapoptotic, mitogenic and other cytokine actions that actively participate in treatment of podocyte damage through prevention of podocyte effacement, detachment and apoptosis. It is hoped that novel stem cell-based therapies will be developed in the future to prevent podocyte injury, thereby reducing the burden of kidney disease.

Matched MeSH terms: Adult Stem Cells
Fulltext The effect of dental unit waterline flushing on the quality of water in dental teaching center in Malaysia

Sa’adiah Shahabudin, Rohayu Hami, Lim, Lee-Sim, Amalina Salleh

Journal of Biomedical and Clinical Sciences, 2018;3(1):72-74.
MyJurnal

The aim of this study to assess the efficiency of flushing
method of Dental Unit Waterline (DUWL) system in reducing the
number of microorganism. Water samples were taken before and after
two minutes of flushing from air-water syringes system in ten randomly
selected dental units in a Dental Teaching Centre. These samples
were immediately transferred to the microbiology laboratory in the cool
box within 8 hours for the heterotrophic plate count (HPC) test. Paired
t-test was used to analyse number of microbe before and after flushing.
The numbers of colony forming unit (CFU) ranged from 13,000 to
120,000CFU/ml in unflushed samples, and 3,000 to 15,000CFU/ml in
flushed samples. The mean HPC post-flushing was lower than preflushing [8360.00 (4561.48) vs 63300.00 (44587.12) CFU/ml]. The
mean HPC between pre- and post-flushing was significantly different
(P=0.004, 95% CI 22039.52, 87840.48). The coliform count from the
control was 140 CFU/ml. In conclusion, flushing method of DUWL
system significantly reduces the number of microorganisms in the
dental unit. However, the level of microorganisms still does not meet
the standard guideline by Environmental Protection Agency for safe
drinking water, which should be below 500 CFU/ml. In our opinion, the
duration of flushing should be increased and additional chemical
treatments of the dental units should be implemented to ensure the
safety of patients and dental personnel.

Matched MeSH terms: Stem Cells
The design of a thermoresponsive surface for the continuous culture of human pluripotent stem cells

Sung TC, Yang JS, Yeh CC, Liu YC, Jiang YP, Lu MW, et al.

Biomaterials, 2019 Nov;221:119411.
PMID: 31419657 DOI: 10.1016/j.biomaterials.2019.119411

Commonly, stem cell culture is based on batch-type culture, which is laborious and expensive. We continuously cultured human pluripotent stem cells (hPSCs) on thermoresponsive dish surfaces, where hPSCs were partially detached on the same thermoresponsive dish by decreasing the temperature of the thermoresponsive dish to be below the lower critical solution temperature for only 30 min. Then, the remaining cells were continuously cultured in fresh culture medium, and the detached stem cells were harvested in the exchanged culture medium. hPSCs were continuously cultured for ten cycles on the thermoresponsive dish surface, which was prepared by coating the surface with poly(N-isopropylacrylamide-co-styrene) and oligovitronectin-grafted poly(acrylic acid-co-styrene) or recombinant vitronectin for hPSC binding sites to maintain hPSC pluripotency. After ten cycles of continuous culture on the thermoresponsive dish surface, the detached cells expressed pluripotency proteins and had the ability to differentiate into cells derived from the three germ layers in vitro and in vivo. Furthermore, the detached cells differentiated into specific cell lineages, such as cardiomyocytes, with high efficiency.

Matched MeSH terms: Pluripotent Stem Cells
Fulltext Epithelial-mesenchymal plasticity-engaging stemness in an interplay of phenotypes

Chin VL, Lim CL

Stem Cell Investig, 2019;6:25.
PMID: 31559312 DOI: 10.21037/sci.2019.08.08

Cancer is a genetic disease which results in a functional imbalance between tumour-repressive and oncogenic signals. The WHO highlights the burden of this indomitable disease, listing it as the second leading cause of death globally. The major cause of cancer-related death is rarely the effect of the primary tumour itself, but rather, the devastating spread of cancer cells in metastases. Epithelial-mesenchymal plasticity (EMP)-termed as the ability of cells to maintain its plasticity and transit between epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) states-plays a fundamental role in cancer metastasis. These cell transitions allow them migrate from the primary tumour and invade the secondary site. EMP is associated with migration, invasion, colonisation, self-renewal and drug resistance. This review briefly elucidates the mechanism of EMP and the association between cancer stem cells (CSCs) and circulating tumour cells (CTCs), biomarkers and signalling pathways involved in EMP as well as drug resistance and therapeutic targeting.

Matched MeSH terms: Neoplastic Stem Cells
Fulltext Polycaprolactone-Based Scaffolds Facilitates Osteogenic Differentiation of Human Adipose-Derived Stem Cells in a Co-Culture System

Rozila I, Azari P, Munirah S, Safwani WKZW, Pingguan-Murphy B, Chua KH

Polymers (Basel), 2021 Feb 17;13(4).
PMID: 33671175 DOI: 10.3390/polym13040597

(1) Background: Stem cells in combination with scaffolds and bioactive molecules have made significant contributions to the regeneration of damaged bone tissues. A co-culture system can be effective in enhancing the proliferation rate and osteogenic differentiation of the stem cells. Hence, the aim of this study was to investigate the osteogenic differentiation of human adipose derived stem cells when co-cultured with human osteoblasts and seeded on polycaprolactone (PCL):hydroxyapatite (HA) scaffold; (2) Methods: Human adipose-derived stem cells (ASC) and human osteoblasts (HOB) were seeded in three different ratios of 1:2, 1:2 and 2:1 in the PCL-HA scaffolds. The osteogenic differentiation ability was evaluated based on cell morphology, proliferation rate, alkaline phosphatase (ALP) activity, calcium deposition and osteogenic genes expression levels using quantitative RT-PCR; (3) Results: The co-cultured of ASC/HOB in ratio 2:1 seeded on the PCL-HA scaffolds showed the most positive osteogenic differentiation as compared to other groups, which resulted in higher ALP activity, calcium deposition and osteogenic genes expression, particularly Runx, ALP and BSP. These genes indicate that the co-cultured ASC/HOB seeded on PCL-HA was at the early stage of osteogenic development; (4) Conclusions: The combination of co-culture system (ASC/HOB) and PCL-HA scaffolds promote osteogenic differentiation and early bone formation.

Matched MeSH terms: Stem Cells
Fulltext Ethical Guiding Principles of "Do No Harm" and the "Intention to Save Lives" in relation to Human Embryonic Stem Cell Research: Finding Common Ground between Religious Views and Principles of Medical Ethics

Sivaraman MAF

Asian Bioeth Rev, 2019 Dec;11(4):409-435.
PMID: 33717326 DOI: 10.1007/s41649-019-00103-4

One of the goals of medicine is to improve well-being, in line with the principle of beneficence (do no harm). Likewise, scientists claim that the goal of human embryonic stem cell (hESC) research is to find treatments for diseases. In hESC research, stem cells are harvested from a 5-day-old embryo. Surplus embryos from infertility treatments or embryos created for the sole purpose of harvesting stem cells are used in the research, and in the process the embryos get destroyed. The use of human embryos for research purpose raises ethical concern. In this context, the religious leaders play the role to be the moral compass and "reality check" to engage with the public. In Malaysia, the Ministry of Health has outlined the Guidelines for Stem Cell Research and Therapy, reflecting on Islamic principles. Since there has not been much focus on the viewpoints of other faiths in Malaysia, this study attempts to (i) explore the ethical guiding principles deliberated by religious leaders from the Buddhist, Hindu and Catholic traditions and (ii) identify if there is a common ground between the mainstream religious views and principles of medical ethics, in relation to hESC research. Eleven religious leaders representing the Buddhist, Hindu and Catholic traditions were interviewed. Interestingly, though reasoning of religious leaders came from different angles, their underlying concerns revolve around the values of "do no harm" and "intention to save lives". These values are also the key principles in medical ethics. The findings are applied to answer the question as to whether religious and medical guiding principles can co-exist and complement in ethical decision-making, without compromising the values.

Matched MeSH terms: Human Embryonic Stem Cells
Lineage-related and particle size-dependent cytotoxicity of chitosan nanoparticles on mouse bone marrow-derived hematopoietic stem and progenitor cells

Omar Zaki SS, Katas H, Hamid ZA

Food Chem Toxicol, 2015 Nov;85:31-44.
PMID: 26051352 DOI: 10.1016/j.fct.2015.05.017

Chitosan nanoparticles (CSNPs) have potential applications in stem cell research. In this study, ex vivo cytotoxicity of CSNPs on mouse bone marrow-derived (MBMCs) hematopoietic stem and progenitor cells (HSPCs) was determined. MBMCs were exposed to CSNPs of different particle sizes at various concentrations for up to 72 h. Cytotoxicity effect of CSNPs on MBMCs was determined using MTT, Live/Dead Viability/Cytotoxicity assays and flow cytometry analysis of surface antigens on HSCs (Sca-1(+)), myeloid-committed progenitors (CD11b(+), Gr-1(+)), and lymphoid-committed progenitors (CD45(+), CD3e(+)). At 24 h incubation, MBMCs' viability was not affected by CSNPs. At 48 and 72 h, significant reduction was detected at higher CSNPs concentrations. Small CSNPs (200 nm) significantly reduced MBMCs' viability while medium-sized particle (∼400 nm) selectively promoted MBMCs growth. Surface antigen assessment demonstrated lineage-dependent effect. Significant decrease in Sca-1(+) cells percentage was observed for medium-sized particle at the lowest CSNPs concentration. Meanwhile, reduction of CD11b(+) and Gr-1(+) cells percentage was detected at high and intermediate concentrations of medium-sized and large CSNPs. Percentage of CD45(+) and CD3e(+) cells along with ROS levels were not significantly affected by CSNPs. In conclusion, medium-sized and large CSNPs were relatively non-toxic at lower concentrations. However, further investigations are necessary for therapeutic applications.

Matched MeSH terms: Hematopoietic Stem Cells
Fulltext Telomere and a final verdict for cellular senescence

Aye Aye Wynn, Nang Khin Mya

Borneo Journal of Medical Sciences, 2020;14(3):57-60.
MyJurnal

Telomeres are specialized DNA complexes found at the end of all chromosomes. Human, as a member of eukaryotic cells, requires telomeres to maintain the length and the stability of chromosomes. Telomeres lose their non-coding DNA sequence to protect the genetic information on the chromosomes. Shortening of telomeres occurs in most somatic cells after sufficient cell division in a human lifetime. Normal haemopoietic cells or stem cells possess telomerase enzyme to restore telomeres and allow further replication. Telomere dysfunction is the origin of several degenerative disorders and also predispose to cancer. Roles of telomere in carcinogenesis and ageing related disorders are reviewed.

Matched MeSH terms: Stem Cells
Interspecific hybridization of cultivated rice, Oryza sativa L. with the wild rice, O. minuta Presl

Mariam AL, Zakri AH, Mahani MC, Normah MN

Theor Appl Genet, 1996 Oct;93(5-6):664-71.
PMID: 24162392 DOI: 10.1007/BF00224060

Crosses were made between four varieties ('Mahsuri', 'Setanjung", 'MR84" and 'MR103") of Oryza sativa L. (2n=24, AA) and one accession of O. minuta (2n= 8, BBCC). The seed set obtained ranged between 9.5% and 25.1% depending on the rice variety used. By rescuing 14-day-old embryos and culturing them on 25%-strength MS medium we obtained a total of 414 F1 hybrids. The F1s were vigorous, tillered profusely, were perennial and male-sterile. The hybrids were triploid (ABC) with 36 chromosomes and showed irregular meiosis. The average frequency and range of chromosome associations at metaphase I or early anaphase I pollen mother cells of F1 plants were 29.31(16-36) Is +3.32(0-10) IIs+0.016(0-1) IIIs+0.002(0-1) IVs. Upon backcrossing the original triploid hybrids and colchicine-treated hybrids to their respective recurrent parents, and further embryo rescue, 17 backcross-1 (BC1) plants were obtained. Of all the crosses using MR84, no BC1 plant was obtained even after pollinating 13 894 spikelets of the triploid hybrid. The BC1s were similar in appearence to the F1s and were male-sterile, their chromosome number ranged from 44 to 48. By backcrossing these BC1s and nurturing them through embryo rescue, we obtained 32 BC2 plants. Of these, however, only 18 plants grew vigorously. One of these plants has 24 chromosomes and the other 17 have chromosome numbers ranging between 30 and 37. The 24-chromosome plant was morphologically similar to the O. sativa parent and was partially fertile with a pollen and spikelet fertility of 58.8% and 12.5% respectively. All of the F1 and BC1 plants were found to be resistant to five Malaysian isolates (XO66, XO99, XO100, XO257 and XO319) of Xanthomonas campestris pv oryzae. Amongst the BC2s, the reaction varied from resistant to moderately susceptible. The 24-chromosome BC2 plant was resistant to the four isolates and moderately resistant to isolate XO100 to which the O. sativa parent was susceptible.

Matched MeSH terms: Stem Cells

Filters

Please provide feedback to Administrator ([email protected])

External Links