ABSTRACT
Being essential in animation creation, colorizing anime line drawings is usually a tedious and time-consuming manual task. Reference-based line drawing colorization provides an intuitive way to automatically colorize target line drawings using reference images. The prevailing approaches are based on generative adversarial networks (GANs), yet these methods still cannot generate high-quality results comparable to manually-colored ones. In this article, a new AnimeDiffusion approach is proposed via hybrid diffusions for the automatic colorization of anime face line drawings. This is the first attempt to utilize the diffusion model for reference-based colorization, which demands a high level of control over the image synthesis process. To do so, a hybrid end-to-end training strategy is designed, including phase 1 for training diffusion model with classifier-free guidance and phase 2 for efficiently updating color tone with a target reference colored image. The model learns denoising and structure-capturing ability in phase 1, and in phase 2, the model learns more accurate color information. Utilizing our hybrid training strategy, the network convergence speed is accelerated, and the colorization performance is improved. Our AnimeDiffusion generates colorization results with semantic correspondence and color consistency. In addition, the model has a certain generalization performance for line drawings of different line styles. To train and evaluate colorization methods, an anime face line drawing colorization benchmark dataset, containing 31,696 training data and 579 testing data, is introduced and shared. Extensive experiments and user studies have demonstrated that our proposed AnimeDiffusion outperforms state-of-the-art GAN-based methods and another diffusion-based model, both quantitatively and qualitatively.
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INTRODUCTION: The meniscus plays an important role in maintaining homeostasis to facilitate the normal function of the knee joint. It is one of the most commonly injured areas of the knee joint. Meniscal-related injuries can lead to significantly decreased athletic ability, and their incidence has increased yearly. It has been found that most meniscal injuries are irreparable, and meniscectomy can increase the predisposition to knee osteoarthritis. Tissue engineering technology on meniscus repairing and transplantation has received widespread attention recently. This review aimed to analyse the scientific literature regarding the potential applications of tissue engineering on meniscus repairing and transplantation procedures. METHOD AND MATERIALS: The electronic search was carried out using PubMed/MEDLINEâdatabases with the keywords "tissue engineering AND meniscus" spanning the period of publications from Jan 1980 until Dec 2022. RESULTS: The literature search identified 405 references in PubMed/MEDLINE, and 179 were selected following the eligibility requirements. The research analysis showed that the existing meniscal tissue engineering studies used a wide variety of seed cells, cytokines, bioactive materials and 3D structures. Each showed distinct advantages and disadvantages in terms of biocompatibility, degradability, mechanical strength, porosity, and etc. It was noted that 3D printing technology is promising for tissue engineering meniscus research. In addition, the optimal use of compression and hydrostatic pressure to markedly improve the functional properties of tissue-engineering meniscal can serve as an useful strategy. CONCLUSION: This review analysed the different approaches employed for meniscus tissue engineering and regeneration. Meniscal tissue engineering still faces several major challenges in terms of seed cells, choice of materials and 3D printing strategies, which should be effectively overcome to harness the full potential of this technology.
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BACKGROUND: Persons discharged from inpatient psychiatric services are at greatly elevated risk of harming themselves or inflicting violence on others, but no studies have reported gender-specific absolute risks for these two outcomes across the spectrum of psychiatric diagnoses. We aimed to estimate absolute risks for self-harm and interpersonal violence post-discharge according to gender and diagnostic category. METHODS: Danish national registry data were utilized to investigate 62,922 discharged inpatients, born 1967-2000. An age and gender matched cohort study was conducted to examine risks for self-harm and interpersonal violence at 1 year and at 10 years post-discharge. Absolute risks were estimated as cumulative incidence percentage values. RESULTS: Patients diagnosed with substance misuse disorders were at especially elevated risk, with the absolute risks for either self-harm or interpersonal violence being 15.6% (95% CI 14.9, 16.3%) of males and 16.8% (15.6, 18.1%) of females at 1 year post-discharge, rising to 45.7% (44.5, 46.8%) and 39.0% (37.1, 40.8%), respectively, within 10 years. Diagnoses of personality disorders and early onset behavioral and emotional disorders were also associated with particularly high absolute risks, whilst risks linked with schizophrenia and related disorders, mood disorders, and anxiety/somatoform disorders, were considerably lower. CONCLUSIONS: Patients diagnosed with substance misuse disorders, personality disorders and early onset behavioral and emotional disorders are at especially high risk for internally and externally directed violence. It is crucial, however, that these already marginalized individuals are not further stigmatized. Enhanced care at discharge and during the challenging transition back to life in the community is needed.
Subject(s)
Mental Health Services , Self-Injurious Behavior , Substance-Related Disorders , Male , Female , Humans , Patient Discharge , Inpatients/psychology , Cohort Studies , Aftercare , Self-Injurious Behavior/diagnosis , Self-Injurious Behavior/epidemiology , Violence/psychology , Substance-Related Disorders/diagnosis , Substance-Related Disorders/epidemiology , Substance-Related Disorders/complications , Risk FactorsABSTRACT
BACKGROUND: Adverse health and social outcomes are known to occur more frequently following parental death during childhood, but evidence is lacking for comparing long-term risks of internalised v. externalised harm. METHODS: This national register-based cohort study consisted of Danish persons born 1970-2000. The Civil Registration System and National Causes of Death Register were linked to ascertain parental deaths by cause before cohort members' 15th birthdays. From age 15 years, hospital-treated self-harm episodes were ascertained through linkage to the National Patient Register and the Psychiatric Central Research Register, and violent crimes were identified via linkage to the National Crime Register. Hazard ratio and cumulative incidence values were estimated. RESULTS: Self-harm and violent criminality risks were elevated following parental death during childhood. Covariate adjustment for gender, birth year and first-degree relatives' mental illnesses attenuated these associations, although significantly heightened risks persisted. The estimated hazard ratios did not differ greatly according to which parent died, but losing both parents conferred particularly large risk increases. Risks for both adverse outcomes were higher in relation to unnatural v. natural parental death; violent criminality risk was especially raised among individuals exposed to parental death by unnatural causes other than suicide. The association was strongest when pre-school age children experienced parental death. CONCLUSIONS: Effective early intervention is needed to help youngsters who have experienced the death of one or both parents to develop immediate and sustained coping strategies. Enhanced cooperation between health and social services and criminal justice agencies may mitigate risks for these two destructive behaviours.
Subject(s)
Adverse Childhood Experiences/statistics & numerical data , Criminal Behavior , Parental Death/statistics & numerical data , Self-Injurious Behavior/epidemiology , Violence/statistics & numerical data , Adolescent , Adult , Bereavement , Child , Cohort Studies , Denmark/epidemiology , Female , Humans , Incidence , Male , Middle Aged , Risk Factors , Suicide/statistics & numerical data , Young AdultABSTRACT
OBJECTIVES: To characterise multi-level obstruction in terms of prevalence, obstructive sleep apnoea severity and predictive factors, and to collect epidemiological data on upper airway morphology in obstructive sleep apnoea patients. METHODS: Retrospective review of 250 obstructive sleep apnoea patients. RESULTS: On clinical examination, 171 patients (68.4 per cent) had multi-level obstruction, 49 (19.6 per cent) had single-level obstruction and 30 (12 per cent) showed no obstruction. Within each category of obstructive sleep apnoea severity, multi-level obstruction was more prevalent. Multi-level obstruction was associated with severe obstructive sleep apnoea (more than 30 events per hour) (p = 0.001). Obstructive sleep apnoea severity increased with the number of obstruction sites (correlation coefficient = 0.303, p < 0.001). Multi-level obstruction was more likely in younger (p = 0.042), male (p = 0.045) patients, with high body mass index (more than 30 kg/m2) (p < 0.001). Palatal (p = 0.004), tongue (p = 0.026) and lateral pharyngeal wall obstructions (p = 0.006) were associated with severe obstructive sleep apnoea. CONCLUSION: Multi-level obstruction is more prevalent in obstructive sleep apnoea and is associated with increased severity. Obstruction at certain anatomical levels contributes more towards obstructive sleep apnoea severity.
Subject(s)
Sleep Apnea, Obstructive/etiology , Adult , Age Factors , Aged , Female , Humans , Male , Middle Aged , Obesity/complications , Prevalence , Respiratory System/pathology , Retrospective Studies , Risk Factors , Severity of Illness Index , Sex Factors , Sleep Apnea, Obstructive/epidemiology , Sleep Apnea, Obstructive/pathology , Young AdultABSTRACT
Numerous lines of evidence support that bone marrow is a rich source of stem cells that can be used for research purposes and to treat some complex blood diseases and cancers. Stem cells are a potential source for regenerative medicine and tissue replacement after injury or disease, and mother cells that possess the capacity to become any type of cell in the body. They are cells without specific structure and characterized by their ability to self-renew or multiply while maintaining the potential to develop into other types of cells. Stem cells can normally become cells of the blood, heart, bones, skin, muscles or brain. Although, there are different sources of stem cells, all types of stem cells have the same capacity to develop into multiple types of cells. Stem cells are generally described as unspecialized cells with unlimited proliferation capacity that can divide (through mitosis) to produce more stem cells. Several types of adult stem cells have been characterized and can be cultured in vitro, including neural stem cells, hematopoietic stem cells, mesenchymal stem cells, cardiac stem cells and epithelial stem cells. They are valuable as research tools and might, in the future, be used to treat a wide range of diseases such as hematological hereditary diseases, Parkinson's disease, diabetes mellitus, heart disease and many other diseases. Currently, two types of stem cells have been identified based on their origins, namely embryonic stem cells and adult stem cells. Collectively, although many kinds of literature have been studying stem cell application in terms of clinical practice, stem cell-based therapy is still in its infancy stage.
Subject(s)
Adult Stem Cells , Cell Differentiation , Stem Cell Transplantation , Embryonic Stem Cells , Humans , Regenerative Medicine , Stem Cells/cytologyABSTRACT
Erythropoietin (EPO) is a glycoprotein hormone conventionally thought to be responsible only in producing red blood cells in our body. However, with the discovery of the presence of EPO and EPO receptors in the retinal layers, the EPO seems to have physiological roles in the eye. In this review, we revisit the role of EPO in the eye. We look into the biological role of EPO in the development of the eye and the physiologic roles that it has. Apart from that, we seek to understand the mechanisms and pathways of EPO that contributes to the therapeutic and pathological conditions of the various ocular disorders such as diabetic retinopathy, retinopathy of prematurity, glaucoma, age-related macular degeneration, optic neuritis, and retinal detachment. With these understandings, we discuss the clinical applications of EPO for treatment of ocular disorders, modes of administration, EPO formulations, current clinical trials, and its future directions.
Subject(s)
Erythropoietin/therapeutic use , Eye Diseases/drug therapy , Erythropoietin/physiology , Eye Diseases/etiology , Eye Diseases/physiopathology , Eye Diseases/prevention & control , HumansABSTRACT
PURPOSE: To investigate the safety and efficacy of subretinal injection of human Wharton's Jelly-derived mesenchymal stem cells (hWJ-MSCs) on retinal structure and function in Royal College of Surgeons (RCS) rats. METHODS: RCS rats were divided into 2 groups: hWJ-MSCs treated group (n = 8) and placebo control group (n = 8). In the treatment group, hWJ-MSCs from healthy donors were injected into the subretinal space in one eye of each rat at day 21. Control group received saline injection of the same volume. Additional 3 animals were injected with nanogold-labelled stem cells for in vivo tracking of cells localisation using a micro-computed tomography (microCT). Retinal function was assessed by electroretinography (ERG) 3 days before the injection and repeated at days 15, 30 and 70 after the injection. Eyes were collected at day 70 for histology, cellular and molecular studies. RESULTS: No retinal tumor formation was detected by histology during the study period. MicroCT scans showed that hWJ-MSCs stayed localised in the eye with no systemic migration. Transmission electron microscopy showed that nanogold-labelled cells were located within the subretinal space. Histology showed preservation of the outer nuclear layer (ONL) in the treated group but not in the control group. However, there were no significant differences in the ERG responses between the groups. Confocal microscopy showed evidence of hWJ-MSCs expressing markers for photoreceptor, Müller cells and bipolar cells. CONCLUSIONS: Subretinal injection of hWJ-MSCs delay the loss of the ONL in RCS rats. hWJ-MSCs appears to be safe and has potential to differentiate into retinal-like cells. The potential of this cell-based therapy for the treatment of retinal dystrophies warrants further studies.
Subject(s)
Mesenchymal Stem Cells/physiology , Retina/pathology , Retinal Degeneration/therapy , Stem Cell Transplantation , Animals , Biomarkers/metabolism , Electroretinography , Gene Expression , Gold/chemistry , Humans , Injections, Intraocular , Mesenchymal Stem Cells/cytology , Metal Nanoparticles/chemistry , Rats , Retina/metabolism , Retinal Degeneration/metabolism , Retinal Degeneration/pathology , Staining and Labeling/methods , Transplantation, Heterologous , Wharton Jelly/cytology , Wharton Jelly/physiology , X-Ray MicrotomographyABSTRACT
Mesenchymal stem cells (MSC) are multipotent, self-renewing cells that can be found mainly in the bone marrow, and other post-natal organs and tissues. The ease of isolation and expansion, together with the immunomodulatory properties and their capability to migrate to sites of inflammation and tumours make them a suitable candidate for therapeutic use in the clinical settings. We review here the cellular mechanisms underlying the emerging applications of MSC in various fields.
Subject(s)
Mesenchymal Stem Cell Transplantation , Mesenchymal Stem Cells/physiology , Animals , HumansABSTRACT
AIM: To compare narrow-band images of nasopharyngeal carcinoma with those of normal adenoidal tissue. METHOD: Patients with a nasopharyngeal mass were evaluated using both conventional white light and narrow-band light. Biopsies were performed and Epstein-Barr viral serology was tested for all patients. RESULTS: Thirty consecutive patients were recruited. Twenty-one patients had normal adenoidal tissue and seven had nasopharyngeal carcinoma. One patient with papillary adenocarcinoma was excluded. The features of narrow-band imaging in normal adenoidal tissue were: (1) a regularly arranged follicular pattern, and (2) each 'follicle' comprising a pale centre with surrounding dark periphery. The features of narrow-band imaging in nasopharyngeal carcinoma were: (1) absence of surface patterns (n = 7), and/or (2) 'reverse', haphazard follicular pattern comprising a dark brown centre and pale periphery (n = 3). CONCLUSION: Narrow-band imaging of the surface of adenoidal tissue and nasopharyngeal carcinoma appears to identify distinct, characteristic features as described. Narrow-band imaging may be a useful adjunct in differentiating normal adenoidal tissue from malignancy. Further studies are needed to evaluate its diagnostic accuracy.
Subject(s)
Adenoids/pathology , Endoscopy/methods , Narrow Band Imaging/methods , Nasopharyngeal Neoplasms/diagnosis , Nasopharynx/pathology , Adult , Aged , Carcinoma , Female , Humans , Male , Middle Aged , Nasopharyngeal Carcinoma , Young AdultSubject(s)
Attitude of Health Personnel , Medicine, Chinese Traditional , Physicians , Acupuncture Therapy , Adult , Age Factors , Cross-Sectional Studies , Education, Medical , Evidence-Based Medicine , Hong Kong , Humans , Interdisciplinary Communication , Medicine, Chinese Traditional/statistics & numerical data , Middle Aged , Patient Preference , Referral and Consultation , Surveys and QuestionnairesABSTRACT
This study investigates the relationship between music and speech, testing whether musical training has any facilitatory effects on native tone language speakers. Some Cantonese tone pairs are merging in recent years. The merging subjects have poorer general lexical tone perception than the control subjects. Previous studies showed that musical training facilitates lexical tone perception of nontone language speakers, but it is unclear if the same is true for tone language speakers. Three groups of listeners (standard Cantonese, merging Cantonese, nontone) with and without musical training participated in AX discrimination tasks of Cantonese monosyllables and pure tones resynthesized from Cantonese lexical tones. Results show that while musical training enhances lexical tone perception of nontone listeners, it has little influence on Cantonese listeners. The findings suggest that the linguistic use of tones is more fundamental and more robust than musical tones. Our results are compatible with the idea that linguistic and musical mechanisms belong to separate but overlapping domains.
Subject(s)
Music , Pitch Perception , Speech Acoustics , Speech Perception , Acoustic Stimulation , Audiometry, Pure-Tone , Audiometry, Speech , Discrimination, Psychological , Humans , Phonetics , PsychoacousticsABSTRACT
Mesenchymal stromal cells (MSC) are an attractive cell-targeting vehicle for gene delivery. MIDGE (an acronym for Minimalistic, Immunologically Defined Gene Expression) construct is relatively safer than the viral or plasmid expression system as the detrimental eukaryotic and prokaryotic gene and sequences have been eliminated. The objective of this study was to test the ability of the human MSC (hMSC) to deliver the erythropoietin (EPO) gene in a nude mice model following nucleofection using a MIDGE construct. hMSC nucleofected with MIDGE encoding the EPO gene was injected subcutaneously in Matrigel at the dorsal flank of nude mice. Subcutaneous implantation of nucleofected hMSC resulted in increased hemoglobin level with presence of human EPO in the peripheral blood of the injected nude mice in the first two weeks post-implantation compared with the control groups. The basal layer of the hair shaft in the dermal layer was found to be significantly positive for immunohistochemical staining of a human EPO antibody. However, only a few basal layers of the hair shaft were found to be positively stained for CD105. In conclusion, hMSC harboring MIDGE-EPO could deliver and transiently express the EPO gene in the nude mice model. These cells could be localized to the hair follicle and secreted EPO protein might have possible role in hair regeneration.
Subject(s)
Cell Movement , Erythropoietin/metabolism , Hair/cytology , Mesenchymal Stem Cell Transplantation , Mesenchymal Stem Cells/cytology , Subcutaneous Tissue/metabolism , Animals , Culture Media , Erythropoietin/blood , Gene Expression , Hemoglobins/metabolism , Humans , Injections , Male , Mesenchymal Stem Cells/metabolism , Mice , Mice, Nude , Models, Animal , Protein Transport , Reproducibility of Results , Time Factors , TransfectionABSTRACT
This is the first report of recurrent nasopharyngeal carcinoma (NPC) presenting as a cerebellopontine angle mass. The clinical presentation, investigation and management of this case, as well as the confusion and dilemma caused, are discussed. We hope to increase awareness on the multifaceted ways in which recurrent NPC could present and to share the lessons learnt from our management of this unusual and unfortunate case.
Subject(s)
Nasopharyngeal Neoplasms/pathology , Neoplasm Recurrence, Local/pathology , Neuroma, Acoustic/pathology , Antineoplastic Combined Chemotherapy Protocols , Biopsy, Needle , Carcinoma , Diagnosis, Differential , Follow-Up Studies , Hearing Loss, Sudden/diagnosis , Hearing Loss, Sudden/etiology , Hospice Care , Humans , Immunohistochemistry , Magnetic Resonance Imaging/methods , Male , Middle Aged , Monitoring, Physiologic/methods , Nasopharyngeal Carcinoma , Nasopharyngeal Neoplasms/radiotherapy , Neoplasm Invasiveness/pathology , Neoplasm Recurrence, Local/diagnosis , Neoplasm Recurrence, Local/drug therapy , Neoplasm Staging , Neuroma, Acoustic/diagnosis , Palliative Care/methods , Radiotherapy Dosage , Risk Assessment , Tinnitus/diagnosis , Tinnitus/etiology , Treatment OutcomeABSTRACT
Human mesenchymal stromal cell (hMSC) is a potential target for cell and gene therapy-based approaches against a variety of different diseases. Whilst cationic lipofection has been widely experimented, the Nucleofector technology is a relatively new non-viral transfection method designed for primary cells and hard-to-transfect cell lines. Herein, we compared the efficiency and viability of nucleofection with cationic lipofection, and used the more efficient transfection method, nucleofection, to deliver a construct of minimalistic, immunologically defined gene expression encoding the erythropoietin (MIDGE-EPO) into hMSC. MIDGE construct is relatively safer than the viral and plasmid expression systems as the detrimental eukaryotic and prokaryotic gene and sequences have been eliminated. Using a plasmid encoding the luciferase gene, we demonstrated a high transfection efficiency using the U-23 (21.79 ± 1.09%) and C-17 (5.62 ± 1.09%) pulsing program in nucleofection. The cell viabilities were (44.93 ± 10.10)% and (21.93 ± 5.72)%, respectively 24 h post-nucleofection. On the other hand, lipofection treatment only yielded less than 0.6% efficiencies despite showing higher viabilities. Nucleofection did not affect hMSC renewability, immunophenotype and differentiation potentials. Subsequently, we nucleofected MIDGE-EPO using the U-23 pulsing program into hMSC. The results showed that, despite a low nucleofection efficiency with this construct, the EPO protein was stably expressed in the nucleofected cells up to 55 days when determined by ELISA or immunocytochemical staining. In conclusion, nucleofection is an efficient non-viral transfection approach for hMSC, which when used in conjunction with a MIDGE construct, could result in extended and stable transgene expression in hMSC.
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It is generally accepted that there is a relationship between body dimensions, body movement and clothing wearing ease design, and yet previous research in this area has been neither sufficient nor systematic. This paper proposes a method to measure the human body in the static state and in 17 dynamic postures, so as to understand dimensional changes of different body parts during dynamic movements. Experimental work is carried out to collect 30 measurements of 10 male Chinese subjects in both static and dynamic states. Factor analysis is used to analyse body measurement data in a static state, and such key measurements describe the characteristics of different body figures. Moreover, one-way ANOVA is used to analyse how dynamic postures affect these key body measurements. Finally, an application of the research results is suggested: a dynamic block patternmaking method for high-performance clothing design.
Subject(s)
Anthropometry , Body Size , Anthropometry/methods , Body Height , Body Mass Index , Body Weight , China , Humans , Male , Movement , Posture , Young AdultABSTRACT
INTRODUCTION: Communication between medical specialists and primary care providers in the community plays a pertinent role in patient care and doctor education. Referral and reply letters are the most common means by which doctors exchange information. Much of clinician time is spent writing letters, but the information or the format in which the letter is written may not meet the needs of the recipient. This study aimed to determine the type of reply letter preferred by general practitioners (GPs) and as such, attempts to improve communication between doctors as part of a quality assurance survey. METHODS: Questionnaires were mailed out to 1,700 GPs in Singapore. Each questionnaire was accompanied by two sample reply letters from the Department of Otorhinolaryngology-Head and Neck Surgery. The sample letters were written in different formats. Letter 1 was written in a non-structured, free text format and Letter 2 included a structured summary at the beginning. Both letters contained the same amount of information and the same number of words. RESULTS: A total of 535 replies (response rate 32 percent) were received. Letter 2 was preferred in 97 percent of the responses. 96 percent of the doctors found Letter 2 to be easier to read, while 86 percent felt it contained more information and 64 percent felt that Letter 1 took a longer time to read. CONCLUSION: Our study shows that there is a preference for diagnosis and treatment plan to be presented in a summary style report rather than as free text. A structured format for reply letters, including the use of headings, allows readers to easily identify the information desired and thus improves the quality of correspondence between specialists and GPs.
Subject(s)
Otolaryngology/methods , Communication , Correspondence as Topic , General Practice , Humans , Interprofessional Relations , Otolaryngology/organization & administration , Quality Assurance, Health Care , Referral and Consultation , Singapore , Specialization , Surveys and QuestionnairesABSTRACT
This paper investigates the effects of syllable structure on vowel-to-vowel (V-to-V) coarticulation using Thai and English data. Languages differ in syllable complexity and their realizations of syllable structure. It was hypothesized that languages with complex syllable structure (English) would allow more V-to-V coarticulation than languages with simple syllable structure (Thai). Onset and coda consonants are different acoustically, articulatorily, typologically and perceptually. Onsets are generally 'stronger' and more stable than codas because they are longer, louder, and involve tighter articulatory constrictions. It was hypothesized that closed syllables (that end in a consonant C, i.e., VC#V) would allow more V-to-V coarticulation than open syllables (V#CV). /C(1)V(1)#C(2)V(2)/ and /C(1)V(1)C(2)#V(2)t/ sequences were recorded from six native speakers in Thai and six in English. First and second formant frequencies were measured. Results show that English allows more V-to-V coarticulation than Thai regardless of the intervocalic duration and vowel quality difference, but open and closed syllables only affect V-to-V coarticulation minimally. In addition to syllable structure, other possible factors contributing to the language difference in V-to-V coarticulation are discussed.
Subject(s)
Language , Phonetics , Speech Acoustics , Speech Perception , Female , Humans , Male , Sound Spectrography , Speech Production Measurement , Time Factors , Verbal BehaviorABSTRACT
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.
Subject(s)
Adipocytes/cytology , Cell Differentiation , Chondrocytes/cytology , Mesenchymal Stem Cells/cytology , Osteoblasts/cytology , Adipocytes/metabolism , Cells, Cultured , Chondrocytes/metabolism , Gene Expression , Humans , Immunohistochemistry , In Vitro Techniques , Mesenchymal Stem Cells/metabolism , Osteoblasts/metabolism , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
BACKGROUND: Mesenchymal stromal cells (MSC) are pluripotent progenitor cells that can be found in human bone marrow (BM). These cells have low immunogenicity and could suppress alloreactive T-cell responses. In the current study, MSC were tested for their capacity to carry and deliver the erythropoietin (EPO) gene in vitro. METHODS: Expanded BM MSC was transfected with EPO-encoded plasmid pMCV1.2 and EPO-encoded MIDGE (minimalistic immunologically defined gene expression) vector by electroporation. The expressed EPO was used to induce hematopoietic stem cells (HSC) into erythroid colonies. RESULTS: The results showed that the MIDGE vector was more effective and stable than the plasmid (pMCV1.2) in delivering EPO gene into MSC. The supernatants containing EPO obtained from the transfected cell culture were able to induce the differentiation of HSC into erythroid colonies. DISCUSSION: MSC hold promise as a cell factory for the production of biologic molecules, and MIDGE vector is more effective and stable than the plasmid in nucleofection involving the EPO gene.