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1.
Hong Kong Med J ; 28(3): 204-214, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35697524

RESUMO

INTRODUCTION: Compared with young children who have acute lymphoblastic leukaemia (ALL), adolescents with ALL have unfavourable disease profiles and worse survival. However, limited data are available regarding the characteristics and outcomes of adolescents with ALL who underwent treatment in clinical trials. The aim of this study was to investigate the causes of treatment failure in adolescents with ALL. METHODS: We retrospectively analysed the outcomes of 711 children with ALL, aged 1-18 years, who were enrolled in five clinical trials of paediatric ALL treatment between 1993 and 2015. RESULTS: Among the 711 children with ALL, 530 were young children (1-9 years at diagnosis) and 181 were adolescents (including 136 younger adolescents [10-14 years] and 45 older adolescents [15-18 years]). Compared with young children who had ALL, adolescents with ALL were less likely to have favourable genetic features and more likely to demonstrate poor early response to treatment. The 10-year overall survival and event-free survival rates were significantly lower among adolescents than among young children (77.9% vs 87.6%, P=0.0003; 69.7% vs 76.5%, P=0.0117). There were no significant differences in the 10-year cumulative incidence of relapse, but the 10-year cumulative incidence of treatment-related death (TRD) was significantly greater among adolescents (7.2%) than among young children (2.3%; P=0.002). Multivariable analysis showed that both younger and older adolescents (vs young children) had worse survival and greater incidence of TRD. CONCLUSION: Adolescents with ALL had worse survival because they experienced a greater incidence of TRD. There is a need to investigate optimal treatment adjustments and novel targeted agents to achieve better survival rates (without excessive toxicity) among adolescents with ALL.


Assuntos
Recidiva Local de Neoplasia , Leucemia-Linfoma Linfoblástico de Células Precursoras , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica , Criança , Pré-Escolar , Intervalo Livre de Doença , Humanos , Incidência , Recidiva Local de Neoplasia/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Estudos Retrospectivos , Taxa de Sobrevida
3.
Curr Res Transl Med ; 68(1): 5-16, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31543433

RESUMO

Mesenchymal stromal cells (MSCs) are widely used in the clinic because they involve fewer ethical issues and safety concerns compared to other stem cells such as embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). MSCs derived from umbilical cord Wharton's jelly (WJ-MSCs) have excellent proliferative potential and a faster growth rate and can retain their multipotency for more passages in vitro compared to adult MSCs from bone marrow or adipose tissue. WJ-MSCs are used clinically for repairing tissue injuries of the spinal cord, liver and heart with the aim of regenerating tissue. On the other hand, WJ-MSCs are also used clinically to ameliorate immune-mediated diseases based on their ability to modulate immune responses. In the field of tissue engineering, WJ-MSCs capable of differentiating into multiple cell lineages have been used to produce a variety of engineered tissues in vitro that can then be transplanted in vivo. This review discusses the characteristics of WJ-MSCs, the differences between WJ-MSCs and adult MSCs, clinical studies involving WJ-MSCs and future perspectives of WJ-MSC research and clinical applications. To summarize, WJ-MSCs have shown promise in treating a variety of diseases clinically. However, most clinical trials/studies reported thus far are relatively smaller in scale. The collected evidence is insufficient to support the routine use of WJ-MSC therapy in the clinic. Thus, rigorous clinical trials are needed in the future to obtain more information on WJ-MSC therapy safety and efficacy.


Assuntos
Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia , Geleia de Wharton/citologia , Adulto , Células-Tronco Adultas/citologia , Linhagem da Célula , Separação Celular/métodos , Células Cultivadas , Doença Crônica/terapia , Ensaios Clínicos como Assunto , Células-Tronco Embrionárias/citologia , Rejeição de Enxerto/terapia , Doença Enxerto-Hospedeiro/terapia , Humanos , Terapia de Imunossupressão , Células-Tronco Pluripotentes Induzidas/citologia , Recém-Nascido , Especificidade de Órgãos , Engenharia Tecidual/métodos
4.
Ann Oncol ; 30(10): 1630-1637, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31373615

RESUMO

BACKGROUND: Previous mass screening studies have shown that IgA antibodies against Epstein-Barr Virus (EBV) can facilitate early detection of nasopharyngeal carcinoma (NPC), but the impact of EBV-antibody screening for NPC-specific mortality remains unknown. PATIENTS AND METHODS: A prospective, cluster randomized, controlled trial for NPC screening (PRO-NPC-001) was conducted in 3 selected towns of Zhongshan City and 13 selected towns of Sihui City in southern China beginning in 2008. Serum samples of the screening group were tested for two previously selected anti-EBV antibodies. Subjects with serological medium risk were subsequently retested annually for 3 years, and those with serological high risk were referred to otorhinolaryngologists for diagnostic check-up. An interim analysis was carried out to evaluate the primary end points of the NPC-specific mortality and the early diagnostic rate, and the secondary end point of the NPC incidence, through linkage with the database of Zhongshan City. RESULTS: Among 70 296 total subjects, 29 413 screened participants (41.8% of the total subjects) in the screening group and 50 636 in the control group, 153 (43.3 per 100 000 person-year), 62 (55.3 per 100 000 person-year) and 99 (33.1 per 100 000 person-year) NPC cases were identified. The early diagnostic rates of NPC were significantly higher in the participants (79.0%, P < 0.0001) and the screening group (45.9%, P < 0.0001) compared with the control group (20.6%). Although no differences were found between NPC-specific mortality of the screening group and the control group [relative risk (RR)= 0.82, 95% confidence interval (CI) 0.37-1.79], lower NPC-specific mortality was noticed among participants from the screening group versus the control group (RR = 0.22, 95% CI 0.09-0.49). CONCLUSION: IgA antibodies against EBV can identify high-risk population and was effective in screening for early asymptomatic NPC. Although the mortality reduction was not significant in the primary end point, we noted encouraging evidence of a mortality reduction in screening participants in this interim analysis. CLINICAL TRIAL NUMBER: NCT00941538.


Assuntos
Detecção Precoce de Câncer/métodos , Infecções por Vírus Epstein-Barr/complicações , Carcinoma Nasofaríngeo/epidemiologia , Carcinoma Nasofaríngeo/mortalidade , Neoplasias Nasofaríngeas/epidemiologia , Neoplasias Nasofaríngeas/mortalidade , Adulto , Anticorpos Antivirais/sangue , Biomarcadores Tumorais/análise , Estudos de Casos e Controles , China/epidemiologia , Infecções por Vírus Epstein-Barr/virologia , Feminino , Seguimentos , Herpesvirus Humano 4/isolamento & purificação , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo/diagnóstico , Carcinoma Nasofaríngeo/virologia , Neoplasias Nasofaríngeas/diagnóstico , Neoplasias Nasofaríngeas/virologia , Prognóstico , Estudos Prospectivos , Fatores de Risco , Taxa de Sobrevida , Carga Viral
5.
Exp Gerontol ; 104: 43-51, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29421350

RESUMO

BACKGROUND: Hyaline articular cartilage, which protects the bones of diarthrodial joints from forces associated with load bearing, frictions, and impacts has very limited capacities for self-repair. Over the years, the trend of treatments has shifted to regenerations and researchers have been on the quest for a lasting regeneration. We evaluated the treatment of osteoarthritis by chondrogenically induced ADSCs and BMSCs for a long time functional recovery. METHODS: Osteoarthritis was induced at the right knee of sheep by complete resection of ACL and medial meniscus. Stem cells from sheep were induced to chondrogenic lineage. Test sheep received 5 mls single doses of 2 × 107 autologous PKH26-labelled ADSCs or BMSCs, while controls received basal medium. Functional recovery of the knees was evaluated via electromyography. RESULTS: Induced ADSCs had 625, 255, 393, 908, 409, 157 and 1062 folds increases of collagen I, collagen II, aggrecan, SOX9, cartilage oligomeric protein, chondroadherin and fibromodullin compare to uninduced cells, while BMSCs had 702, 657, 321, 276, 337, 233 and 1163 respectively; p = .001. Immunocytochemistry was positive for these chondrogenic markers. 12 months post-treatment, controls scored 4 in most regions using ICRS, while the treated had 8; P = .001. Regenerated cartilages were positive to PKH26 and demonstrated the presence of condensing cartilages on haematoxylin and eosin; and Safranin O. OA degenerations caused significant amplitude shift from right to left hind limb. After treatments, controls persisted with significant decreases; while treated samples regained balance. CONCLUSIONS: Both ADSCs and BMSCs had increased chondrogenic gene expressions using TGF-ß3 and BMP-6. The treated knees had improved cartilage scores; PKH26 can provide elongated tracking, while EMG results revealed improved joint recoveries. These could be suitable therapies for osteoarthritis.


Assuntos
Cartilagem Articular/fisiopatologia , Condrogênese , Transplante de Células-Tronco Mesenquimais , Osteoartrite do Joelho/terapia , Regeneração , Tecido Adiposo/citologia , Animais , Artroscopia , Células da Medula Óssea/citologia , Proteína Morfogenética Óssea 6/farmacologia , Cartilagem Articular/patologia , Cartilagem Articular/cirurgia , Técnicas de Cultura de Células , Diferenciação Celular , Proliferação de Células , Separação Celular , Sobrevivência Celular , Rastreamento de Células , Modelos Animais de Doenças , Expressão Gênica , Masculino , Células-Tronco Multipotentes/citologia , Osteoartrite do Joelho/fisiopatologia , Ovinos , Fator de Crescimento Transformador beta3/farmacologia
6.
PLoS One ; 10(6): e0128973, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26107378

RESUMO

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.


Assuntos
Células-Tronco Mesenquimais/fisiologia , Retina/patologia , Degeneração Retiniana/terapia , Transplante de Células-Tronco , Animais , Biomarcadores/metabolismo , Eletrorretinografia , Expressão Gênica , Ouro/química , Humanos , Injeções Intraoculares , Células-Tronco Mesenquimais/citologia , Nanopartículas Metálicas/química , Ratos , Retina/metabolismo , Degeneração Retiniana/metabolismo , Degeneração Retiniana/patologia , Coloração e Rotulagem/métodos , Transplante Heterólogo , Geleia de Wharton/citologia , Geleia de Wharton/fisiologia , Microtomografia por Raio-X
7.
Osteoarthritis Cartilage ; 23(8): 1294-306, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25887366

RESUMO

OBJECTIVES: Our previous studies on osteoarthritis (OA) revealed positive outcome after chondrogenically induced cells treatment. Presently, the functional improvements of these treated OA knee joints were quantified followed by evaluation of the mechanical properties of the engineered cartilages. METHODS: Baseline electromyogram (EMGs) were conducted at week 0 (pre-OA), on the locomotory muscles of nine un-castrated male sheep (Siamese long tail cross) divided into controls, adipose-derived stem cells (ADSCs) and bone marrow stem cells (BMSCs), before OA inductions. Subsequent recordings were performed at week 7 and week 31 which were post-OA and post-treatments. Afterwards, the compression tests of the regenerated cartilage were performed. RESULTS: Post-treatment EMG analysis revealed that the control sheep retained significant reductions in amplitudes at the right medial gluteus, vastus lateralis and bicep femoris, whereas BMSCs and ADSCs samples had no further significant reductions (P < 0.05). Grossly and histologically, the treated knee joints demonstrated the presence of regenerated neo cartilages evidenced by the fluorescence of PKH26 tracker. Based on the International Cartilage Repair Society scores (ICRS), they had significantly lower grades than the controls (P < 0.05). The compression moduli of the native cartilages and the engineered cartilages differed significantly at the tibia plateau, patella femoral groove and the patella; whereas at the medial femoral condyle, they had similar moduli of 0.69 MPa and 0.40-0.64 MPa respectively. Their compression strengths at all four regions were within ±10 MPa. CONCLUSION: The tissue engineered cartilages provided evidence of functional recoveries associated to the structural regenerations, and their mechanical properties were comparable with the native cartilage.


Assuntos
Tecido Adiposo/citologia , Artrite Experimental/terapia , Transplante de Medula Óssea , Condrogênese/fisiologia , Osteoartrite/terapia , Transplante de Células-Tronco , Animais , Artrite Experimental/fisiopatologia , Cartilagem Articular/patologia , Cartilagem Articular/fisiopatologia , Modelos Animais de Doenças , Eletromiografia , Masculino , Osteoartrite/fisiopatologia , Regeneração , Ovinos , Joelho de Quadrúpedes/patologia , Joelho de Quadrúpedes/fisiopatologia
9.
Tissue Cell ; 44(3): 156-63, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22402173

RESUMO

Tracking of transplanted cells has become an important procedure in cell therapy. We studied the in vitro dye retention, survival and in vivo tracking of stem cells with PKH26 dye. Sheep BMSCs and ADSCs were labeled with 2, 4 and 8 µmol of PKH26 and monitored for six passages. Labeled BMSCs and ADSCs acquired mean cumulative population doubling of 12.7±0.4 and 14.6±0.5; unlabeled samples had 13.8±0.5 and 15.4±0.6 respectively. Upon staining with 2, 4 and 8 µmol PKH26, BMSCs had retentions of 40.0±5.8, 60.0±2.9 and 95.0±2.9%, while ADSCs had 92.0±1.2, 95.0±1.2 and 98.0±1.2%. ADSCs retentions were significantly higher at 2 and 4 µmol. On dye retention comparison at 8 µmol and 4 µmol for BMSCs and ADSCs; ADSCs were significantly higher at passages 2 and 3. The viability of BMSCs reduced from 94.0±1.2% to 90.0±0.6% and ADSCs from 94.0±1.2% to 52.0±1.2% (p<0.05) after 24h. BMSCs had significant up regulation of the cartilage genes for both the labeled and the unlabeled samples compared to ADSCs (p<0.05). PKH26 fluorescence was detected on the resected portions of the regenerated neo-cartilage. The recommended concentration of PKH26 for ADSCs is 2 µmol and BMSCs is 8 µmol, and they can be tracked up to 49 days.


Assuntos
Tecido Adiposo/citologia , Células da Medula Óssea/química , Rastreamento de Células/métodos , Compostos Orgânicos/química , Coloração e Rotulagem/métodos , Células-Tronco/química , Tecido Adiposo/química , Animais , Diferenciação Celular , Sobrevivência Celular , Células Cultivadas , Condrogênese , Meios de Cultura , Fluorescência , Corantes Fluorescentes/química , Regulação da Expressão Gênica , Ovinos , Transplante de Células-Tronco
10.
Br J Dermatol ; 167(1): 44-9, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22348415

RESUMO

BACKGROUND: Allopurinol has been reported as a common cause of severe cutaneous adverse reactions (SCARs). Recent studies in various populations suggest that HLA-B*58:01 is a strong genetic marker for allopurinol-induced SCAR, especially in populations with a high frequency of HLA-B*58:01. OBJECTIVES: To confirm the association link between HLA-B*58:01 and hypersensitivity reactions attributed to allopurinol use in Han Chinese patients in Hong Kong. METHODS: We performed a case-control study to investigate whether the HLA-B*58:01 allele predisposes to allopurinol-induced SCAR in Han Chinese patients in Hong Kong. The HLA-B*58:01 genotyping was performed in 20 patients with allopurinol-induced SCAR or erythema multiforme major (EMM; n = 1) and in 30 patients tolerant to allopurinol. RESULTS: All of the 19 patients with allopurinol-induced SCAR examined but not the patient with EMM carried HLA-B*58:01 whereas only four (13%) of the control patients had this allele. The positive rate of the HLA-B*58:01 was significantly higher in the cases than in the allopurinol-tolerant control group [odds ratio (OR) 123·5, 95% confidence interval (CI) 12·8-1195·1; P < 1 × 10(-4) ] and was even higher after removal of the patient with EMM (OR 229·7, 95% CI 11·7-4520·4). The sensitivity and specificity of the HLA-B*58:01 allele for prediction of allopurinol-induced SCAR were 100% and 86·7%, respectively. CONCLUSIONS: This study confirmed the strong association between the HLA-B*58:01 and allopurinol-induced SCAR in Hong Kong Han Chinese patients. A screening test for the HLA-B*58:01 allele should effectively reduce the risk for allopurinol-induced SCAR in Chinese populations.


Assuntos
Alopurinol/efeitos adversos , Toxidermias/genética , Antígenos HLA-B/genética , Uricosúricos/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Povo Asiático/etnologia , Estudos de Casos e Controles , Toxidermias/etnologia , Feminino , Predisposição Genética para Doença/etnologia , Predisposição Genética para Doença/genética , Genótipo , Hong Kong/etnologia , Humanos , Masculino , Pessoa de Meia-Idade
11.
Oncogene ; 30(9): 1127-34, 2011 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-21057531

RESUMO

c-Met represents an important emerging therapeutic target in cancer. In this study, we demonstrate the mechanism by which c-Met tyrosine kinase inhibition inhibits tumor growth in a highly invasive Asian-prevalent head and neck cancer, nasopharyngeal cancer (NPC). c-Met tyrosine kinase inhibitors (TKIs; AM7 and c-Met TKI tool compound SU11274) downregulated c-Met phosphorylation, resulting in marked inhibition of NPC cell growth and invasion. Strikingly, inhibition of c-Met resulted in significant downregulation of TP53-induced Glycolysis and Apoptosis Regulator (TIGAR) and subsequent depletion of intracellular NADPH. Importantly, overexpression of TIGAR ameliorated the effects of c-Met kinase inhibition, confirming the importance of TIGAR downregulation in the growth inhibitory activity of c-Met TKI. The effects of c-Met inhibition on TIGAR and NADPH levels were observed with two different c-Met TKIs (AM7 and SU11274) and with multiple cell lines. As NADPH provides a crucial reducing power required for cell survival and proliferation, our findings reveal a novel mechanistic action of c-Met TKI, which may represent a key effect of c-Met kinase inhibition. Our data provide the first evidence linking c-Met, TIGAR and NADPH regulation in human cancer cells suggesting that inhibition of a tyrosine kinase/TIGAR/NADPH cascade may have therapeutic applicability in human cancers.


Assuntos
Indóis/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/genética , NADP/biossíntese , Neoplasias Nasofaríngeas/metabolismo , Piperazinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-met/antagonistas & inibidores , Pirimidinonas/farmacologia , Quinolinas/farmacologia , Sulfonamidas/farmacologia , Apoptose , Proteínas Reguladoras de Apoptose , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular , Regulação para Baixo , Humanos , Neoplasias Nasofaríngeas/tratamento farmacológico , Neoplasias Nasofaríngeas/patologia , Monoéster Fosfórico Hidrolases , Fosforilação , Proteínas Proto-Oncogênicas c-met/genética , Proteínas Proto-Oncogênicas c-met/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética
12.
Br J Cancer ; 96(4): 623-30, 2007 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-17285127

RESUMO

We have monitored Epstein-Barr virus (EBV) IgA antibody levels of 39 nasopharyngeal carcinoma (NPC) cases for up to 15 years before clinical onset of NPC, and assessed preclinical serologic status of another 68 cases. Our results identify a serologic window preceding diagnosis when antibody levels are raised and sustained. This window can persist for as long as 10 years, with a mean duration estimated to as 37+/-28 months. Ninety-seven of these 107 NPC cases exhibited such a window. Cases that did not may reflect individual antibody response to EBV. Serologic screening at enrollment identified those cases who had already entered the window and became clinically manifested earlier (median=28 months) than those who entered the window after enrollment (median=90 months). The former account for 19 of 21 cases diagnosed within 2 years of screening. Nasopharyngeal carcinoma risk levels among seropositive subjects were also highest during this period. Both prediction rates and risk levels declined thereafter; cases detected at later times were composed of increasing proportions of individuals who entered the serological window after screening. Our findings establish EBV antibody as an early marker of NPC and suggest that repeated screening to monitor cases as they enter this window has considerable predictive value, with practical consequences for cancer treatment.


Assuntos
Anticorpos Antivirais/sangue , Herpesvirus Humano 4/imunologia , Imunoglobulina A/sangue , Neoplasias Nasofaríngeas/diagnóstico , Neoplasias Nasofaríngeas/imunologia , Adulto , Progressão da Doença , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Nasofaríngeas/sangue , Estadiamento de Neoplasias , Valor Preditivo dos Testes , Fatores de Risco , Sensibilidade e Especificidade , Testes Sorológicos/métodos
13.
Br J Cancer ; 96(4): 617-22, 2007 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-17262084

RESUMO

Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus-associated disease with high prevalence in Southern Chinese. Using multiparametric flow cytometry, we identified significant expansions of circulating naïve and memory CD4+CD25(high) T cells in 56 NPC patients compared with healthy age- and sex-matched controls. These were regulatory T cells (Treg), as they overexpressed Foxp3 and GITR, and demonstrated enhanced suppressive activities against autologous CD4+CD25- T-cell proliferation in functional studies on five patients. Abundant intraepithelial infiltrations of Treg with very high levels of Foxp3 expression and absence of CCR7 expression were also detected in five primary tumours. Our current study is the first to demonstrate an expansion of functional Treg in the circulation of NPC patients and the presence of infiltrating Treg in the tumour microenvironment. As Treg may play an important role in suppressing antitumour immunity, our findings provide critical insights for clinical management of NPC.


Assuntos
Fatores de Transcrição Forkhead/biossíntese , Linfócitos do Interstício Tumoral/imunologia , Neoplasias Nasofaríngeas/imunologia , Receptores de Fator de Crescimento Neural/biossíntese , Receptores do Fator de Necrose Tumoral/biossíntese , Linfócitos T Reguladores/imunologia , Proliferação de Células , Células Cultivadas , Citometria de Fluxo/métodos , Proteína Relacionada a TNFR Induzida por Glucocorticoide , Humanos , Subunidade alfa de Receptor de Interleucina-2/biossíntese , Estadiamento de Neoplasias , Sensibilidade e Especificidade
14.
Diabetologia ; 49(10): 2299-308, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16944095

RESUMO

AIMS/HYPOTHESIS: The objective of the study was to investigate risk factors and develop risk equations for end-stage renal disease (ESRD) in Chinese patients with type 2 diabetes. SUBJECTS AND METHODS: A prospective cohort of 4,438 patients with type 2 diabetes mellitus and without ESRD (median observation period 2.9 years, interquartile range 1.6-4.1 years) was included in the analysis. The end-point (ESRD) was defined by: (1) death due to diabetes with renal manifestations or renal failure; (2) hospitalisation due to renal failure; (3) estimated GFR (eGFR) <15 ml min(-1) 1.73 m(-2). Cox proportional hazards regression was used to develop risk equations. The data were randomly and evenly divided into the training data for development of the risk equations and the test data for validation. The validation was performed using the area under the receiver operating characteristic curve (aROC), which takes into account follow-up time and censoring. RESULTS: During the observation period, 159 patients or 12.45 per 1,000 person-years (95% CI 10.52-14.37 per 1,000 person-years) developed ESRD. Known duration of diabetes, systolic blood pressure, log(10) total cholesterol:HDL cholesterol ratio and retinopathy were significant predictors of ESRD. After further adjusting for eGFR, log(10) spot albumin:creatinine ratio (ACR) and haematocrit, only eGFR, haematocrit and log(10) ACR remained as independent predictors of ESRD. The risk equation derived from these three independent predictors had good discrimination, with an aROC of 0.97. CONCLUSIONS/INTERPRETATION: Estimated GFR, haematocrit and ACR were independent predictors of ESRD and the derived risk equation performed well in Chinese patients with type 2 diabetes.


Assuntos
Povo Asiático/estatística & dados numéricos , Diabetes Mellitus Tipo 2/epidemiologia , Falência Renal Crônica/epidemiologia , Pressão Sanguínea , Colesterol/sangue , Estudos de Coortes , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/fisiopatologia , Dieta para Diabéticos , Feminino , Seguimentos , Taxa de Filtração Glomerular , Hong Kong/epidemiologia , Humanos , Falência Renal Crônica/sangue , Falência Renal Crônica/fisiopatologia , Masculino , Prognóstico , Estudos Prospectivos , Sistema de Registros , Fatores de Risco , Fumar/epidemiologia , Fatores de Tempo
15.
Hong Kong Med J ; 12(1): 33-9, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16495587

RESUMO

OBJECTIVE: To study the outcome of children with acute lymphoblastic leukaemia who were treated using a protocol including one or two delayed intensifications. DESIGN: Prospective single-arm multicentre study. SETTING: Five designated children cancer units of the Hospital Authority of Hong Kong. PATIENTS: Children aged between 1 and 17.9 years with newly diagnosed acute lymphoblastic leukaemia seen from November 1997 to December 2002. INTERVENTION: Chemotherapy was modified from a German Berlin-Frankfurt-Muenster 95 (BFM95) protocol that included a delayed intensification similar to the induction phase repeated 5 months after diagnosis. High-risk patients were given double delayed intensification. MAIN OUTCOME MEASURES: Overall survival and event-free survival of the whole group and the three risk groups (standard-, intermediate-, and high-risk groups), and comparison with historical controls. RESULTS: A total of 171 patients were recruited with a median age at diagnosis of 5.57 years (range, 1.15-17.85 years). The induction remission rate was 95.3% and non-leukaemia mortality during remission was 2.3%. At 4 years, the relapse rate of this (HKALL97) study was significantly lower than that of the HKALL93 study (15.7 vs 37.3%; P<0.001). The 4-year overall survival of HKALL97 and HKALL93 studies were 86.5% and 81.8%, respectively (P=0.51). The 4-year event-free survival for HKALL97 and HKALL93 studies were 79% and 65%, respectively (P=0.007). Nonetheless the difference of event-free survival was most remarkable in the intermediate-risk group: 75.6% and 53.1% for HKALL97 and HKALL93 studies, respectively (P=0.06). CONCLUSION: A more intensive delayed consolidation phase improved the outcome for children with acute lymphoblastic leukaemia by reducing relapses at 4 years. The early treatment complications were manageable and non-leukaemia mortality during remission remained low.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Adolescente , Criança , Pré-Escolar , Intervalo Livre de Doença , Feminino , Hong Kong/epidemiologia , Humanos , Lactente , Masculino , Recidiva Local de Neoplasia/epidemiologia , Estudos Prospectivos , Indução de Remissão , Medição de Risco , Taxa de Sobrevida
16.
J Clin Pathol ; 59(5): 468-76, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16461566

RESUMO

BACKGROUND: Severe acute respiratory syndrome (SARS) is an infectious disease which was caused by a novel coronavirus (SARS-CoV). SARS has caused an outbreak in the world during 2003 and 2004, with 8098 individuals being infected and a death toll of 774 in 28 regions around the world. Specific humoral responses to viral infection remain unclear. OBJECTIVE: To analyse the antigenicity of the SARS-CoV genome and identify potential antigenic epitopes in the structural proteins. METHODS: Potential antigenic epitopes were identified in the structural proteins (nucleocapsid, membrane, spike, and small envelope proteins) and hypothetical proteins (SARS3a, 3b, 6, 7a, and 9b) that are specific for SARS-CoV. A peptide chip platform was created and the profiles of antibodies to these epitopes were investigated in 59 different SARS patients' sera obtained 6-103 days after the onset of the illness. Serial sera from five additional patients were also studied. RESULTS: Epitopes at the N-terminus of the membrane protein and the C-terminus of nucleocapsid protein elicited strong antibody responses. Epitopes on the spike protein were only moderately immunogenic but the effects were persistent. Antibodies were also detected for some putative proteins, noticeably the C-termini of SARS3a and SARS6. CONCLUSIONS: Important epitopes of the SARS-CoV genome that may serve as potential markers for the viral infection are identified. These specific antigenic sites may also be important for vaccine development against this new fatal infectious disease.


Assuntos
Antígenos Virais/genética , Epitopos/genética , Síndrome Respiratória Aguda Grave/imunologia , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/genética , Anticorpos Antivirais/imunologia , Formação de Anticorpos , Antígenos Virais/imunologia , Mapeamento de Epitopos , Epitopos/imunologia , Genoma Viral , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Síndrome Respiratória Aguda Grave/virologia , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/imunologia , Proteínas Estruturais Virais/genética , Proteínas Estruturais Virais/imunologia
17.
Med J Malaysia ; 60 Suppl C: 53-8, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16381285

RESUMO

Spinal fusion using autologous bone graft is performed in an increasing rate for many spinal disorders. However, graft harvesting procedure is associated with prolonged operation time and potential donor site morbidity. We produced an engineered 'bone graft' substitute by using porous hydroxyapatite (HA) scaffold seeded with autologous bone marrow osteoprogenitor cells (OPCs) and fibrin. This obviates bone graft harvesting, thus eliminates donor site morbidity and shortens the operation time. The aim of this study is to evaluate Hydroxyapatite (HA) ceramics as scaffold for autologous tissue engineered bone construct for spinal fusion in a sheep model. The sheep's marrow was aspirated from iliac crest. The bone marrow mesenchymal stem cells (BMMSCs) were cultured for several passages in the presence of growth and differentiation factors to increase the number of OPCs. After the cultures reached confluence, they were trypsinized and seeded on Hydroxyapatite scaffold (HA). Approximately 5 million cells were generated after 3 weeks of culture. Microscopically, very tight Colony Forming Units (CFU-Fs) were seen on monolayer culture. The Von Kossa and Alizarin Red staining of monolayer culture showed positive mineralization areas; indicating the presence of OPCs. Sheep underwent a posterolateral spinal fusion in which scaffolds with or without OPCs seeded were implanted on both sides of the lumbar spine (L1-L2). Intended fusion segments were immobilized using wires. At the end of third month, the fusion constructs were harvested for histological examination. Fibrous tissue infiltration found in the inter-connecting pores of plain HA ceramics indicates inefficient new bone regeneration. New bone was found surrounding the HA ceramics seeded with autologous cells. The new bone is probably formed by the sheep BMMSCs that were initially encapsulating HA while it remained intact. The new bone is naturally fused with the vertebrae. In conclusion, the incorporation of autologous bone marrow cells improved the effectiveness of HA ceramics as 'bone graft' substitute for spinal fusion.


Assuntos
Substitutos Ósseos , Durapatita , Fibrina , Células-Tronco Mesenquimais , Fusão Vertebral/métodos , Animais , Ovinos , Engenharia Tecidual/métodos
18.
Med J Malaysia ; 59 Suppl B: 41-2, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15468809

RESUMO

Bone marrow stem cells (BMSC), known for its multipotency to differentiate into various mesenchymal cells such as chodrocyte, osteoblasts, adipocytes, etc, have been actively applied in tissue engineering. BMSC have been successfully isolated from bone marrow aspirate and bone marrow scraping from patients of various ages (13-56 years) with as little as 2ml to 5ml aspirate. BMSC isolated from our laboratory showed the presence of a heterogenous population that showed varying prevalence of surface antigens and the presence of telomerase activity albeit weak. Upon osteogenic induction, alkaline phosphatase activity and mineralization activity were observed.


Assuntos
Transplante de Medula Óssea , Transplante Ósseo , Transplante de Células-Tronco Mesenquimais , Engenharia Tecidual , Células da Medula Óssea/citologia , Regeneração Óssea/fisiologia , Diferenciação Celular/fisiologia , Humanos , Telomerase/metabolismo
19.
Med J Malaysia ; 59 Suppl B: 43-4, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15468810

RESUMO

The strategy used to generate tissue-engineered bone construct, in view of future clinical application is presented here. Osteoprogenitor cells from periosteum of consenting scoliosis patients were isolated. Growth factors viz TGF-B2, bFGF and IGF-1 were used in concert to increase cell proliferation during in vitro cell expansion. Porous tricalcium phosphate (TCP)-hydroxyapatite (HA) scaffold was used as the scaffold to form 3D bone construct. We found that the addition of growth factors, greatly increased cell growth by 2 to 7 fold. TCP/HA proved to be the ideal scaffold for cell attachment and proliferation. Hence, this model will be further carried out on animal trial.


Assuntos
Regeneração Óssea/fisiologia , Transplante Ósseo , Transplante de Células-Tronco Mesenquimais , Periósteo/citologia , Engenharia Tecidual/métodos , Divisão Celular/fisiologia , Colágeno/metabolismo , Humanos , Técnicas de Cultura de Órgãos
20.
Med J Malaysia ; 59 Suppl B: 196-7, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15468885

RESUMO

Bone marrow harvested by aspiration contains connective tissue progenitor cells which can be selectively isolated and induced to express bone phenotype in vitro. The osteoblastic progenitor can be estimated by counting the number of cells attach using the haemacytometer. This study was undertaken to test the hypothesis that human aging is associated with a significant change on the number of osteoblastic progenitors in the bone marrow. Bone marrow aspirates were harvested from 38 patients, 14 men (age 11-70) and 24 women (age 10-70) and cultured in F12: DMEM (1:1). In total 15 bone marrow samples have been isolated from patients above 40 years old (men/women) of age. Fourteen (93.3%) of this samples failed to proliferate. Only one (6.7%) bone marrow sample from a male patient, aged 59 years old was successfully cultured. Seventy percent (16/23) of the samples from patient below than 40 years old were successfully cultured. However, our observation on the survival rate for cells of different gender from patient below 40 years old does not indicate any significant difference. From this study, we conclude that the growth of bone marrow stromal cells possibly for bone engineering is better from bone marrow aspirates of younger patient.


Assuntos
Células da Medula Óssea/citologia , Divisão Celular/fisiologia , Senescência Celular/fisiologia , Células-Tronco Mesenquimais/citologia , Osteoblastos/citologia , Engenharia Tecidual , Adolescente , Adulto , Fatores Etários , Idoso , Sobrevivência Celular/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Células Estromais/citologia
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