Outcomes of adolescents with acute lymphoblastic leukaemia.

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.

Characteristics and clinical applications of Wharton's jelly-derived mesenchymal stromal cells.

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.

Incidence and mortality of nasopharyngeal carcinoma: interim analysis of a cluster randomized controlled screening trial (PRO-NPC-001) in southern China.

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.

Long-term evaluation of osteoarthritis sheep knee, treated with TGF-ß3 and BMP-6 induced multipotent stem cells.

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.

Safety and Efficacy of Human Wharton's Jelly-Derived Mesenchymal Stem Cells Therapy for Retinal Degeneration.

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.

Improved functional assessment of osteoarthritic knee joint after chondrogenically induced cell treatment.

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.

Protection against hepatitis E virus infection by naturally acquired and vaccine-induced immunity.

Immunity acquired from infection or vaccination protects humans from symptomatic hepatitis E. However, whether the risk of hepatitis E virus (HEV) infection is reduced by the immunity remains unknown. To understand this issue, a cohort with 12 409 participants randomized to receive the hepatitis E vaccine Hecolin(®) or placebo were serologically followed up for 2 years after vaccination. About half (47%) of participants were initially seropositive. A total of 139 infection episodes, evidenced by four-fold or greater rise of anti-HEV level or positive seroconversion, occurred in participants who received three doses of treatment. Risk of infection was highest among the baseline seronegative placebo group participants (2.04%). Pre-existing immunity and vaccine-induced immunity lower the risk significantly, to 0.52% and 0.30%, respectively. In conclusion, both vaccine-induced and naturally acquired immunity can effectively protect against HEV infection.

Sciatic nerve repair with tissue engineered nerve: Olfactory ensheathing cells seeded poly(lactic-co-glygolic acid) conduit in an animal model.

BACKGROUND AND AIM: Synthetic nerve conduits have been sought for repair of nerve defects as the autologous nerve grafts causes donor site morbidity and possess other drawbacks. Many strategies have been investigated to improve nerve regeneration through synthetic nerve guided conduits. Olfactory ensheathing cells (OECs) that share both Schwann cell and astrocytic characteristics have been shown to promote axonal regeneration after transplantation. The present study was driven by the hypothesis that tissue-engineered poly(lactic-co-glycolic acid) (PLGA) seeded with OECs would improve peripheral nerve regeneration in a long sciatic nerve defect. MATERIALS AND METHODS: Sciatic nerve gap of 15 mm was created in six adult female Sprague-Dawley rats and implanted with PLGA seeded with OECs. The nerve regeneration was assessed electrophysiologically at 2, 4 and 6 weeks following implantation. Histopathological examination, scanning electron microscopic (SEM) examination and immunohistochemical analysis were performed at the end of the study. RESULTS: Nerve conduction studies revealed a significant improvement of nerve conduction velocities whereby the mean nerve conduction velocity increases from 4.2 ΁ 0.4 m/s at week 2 to 27.3 ΁ 5.7 m/s at week 6 post-implantation (P < 0.0001). Histological analysis revealed presence of spindle-shaped cells. Immunohistochemical analysis further demonstrated the expression of S100 protein in both cell nucleus and the cytoplasm in these cells, hence confirming their Schwann-cell-like property. Under SEM, these cells were found to be actively secreting extracellular matrix. CONCLUSION: Tissue-engineered PLGA conduit seeded with OECs provided a permissive environment to facilitate nerve regeneration in a small animal model.

Bone marrow and adipose stem cells can be tracked with PKH26 until post staining passage 6 in in vitro and in vivo.

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.

Association between HLA-B*58:01 allele and severe cutaneous adverse reactions with allopurinol in Han Chinese in Hong Kong.

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.

Inhibition of c-Met downregulates TIGAR expression and reduces NADPH production leading to cell death.

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.

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

Previous studies suggested telomerase activity as a determinant of cell replicative capacity by delaying cell senescence. This study aimed to evaluate the feasibility of adopting telomerase activity as a selection criterion for in vitro expanded skin cells before autologous transplantation. Fibroblasts and keratinoctyes were derived from the same consenting patients aged 9-69 years, and cultured separately in serum-supplemented and serum-free media, respectively. Telomerase activity of fresh and cultured cells were measured and correlated with cell growth rate, donor age and passage number. The results showed that telomerase activity and cell growth were independent of donor age for both cell types. Telomerase was expressed in freshly digested epidermis and dermis and continued expressing in vitro. Keratinocytes consistently showed 3-12 folds greater telomerase activity than fibroblast both in vivo and in vitro. Conversely, growth rate for fibroblast exceeded that of keratinocyte. Telomerase activity decreased markedly at Passage 6 for keratinocytes and ceased by Passage 3 for fibroblasts. The decrease or cessation of telomerase activity coincided with senescence for keratinocyte but not for fibroblast, implying a telomerase-regulated cell senescence for the former and hence a predictor of replicative capacity for this cell type. Relative telomerase activity for fibroblasts from the younger age group was significantly higher than that from the older age group; 69.7% higher for fresh isolates and 31.1% higher at P0 (p<0.05). No detectable telomerase activity was to be found at later subcultures for both age groups. Similarly for keratinocytes, telomerase activity in the younger age group was significantly higher (p<0.05) compared to that in the older age group; 507.7% at P0, 36.8% at P3 and the difference was no longer significant at P6. In conclusion, the study provided evidence that telomerase sustained the proliferation of keratinocytes but not fibroblasts. Telomerase activity is an important criterion for continued survival and replication of keratinocytes, hence its positive detection before transplantation is desirable. Inferring from our results, the use of keratinocytes from Passage 3 or lesser for construction of skin substitute or cell-based therapy is recommended owing to their sustained telomerase expression.

Narcolepsy in Southern Chinese patients: clinical characteristics, HLA typing and seasonality of birth.

OBJECTIVE: To report clinical characteristics, human leukocyte antigen (HLA) typing and seasonality of birth of a series of 54 Southern Chinese patients suffering from narcolepsy. METHODS: All subjects underwent detailed medical and psychiatric interviews and a standardised nocturnal polysomnogram followed by a daytime Multiple Sleep Latency Test. Each subject also completed a set of sleep questionnaires. HLA typing was performed in 91% of subjects. RESULTS: A total of 78% and 22% of patients were diagnosed with suffering from cataplectic and non-cataplectic narcolepsy, respectively. The majority (n = 47, 87%) of patients were referred to our sleep clinic for excessive daytime sleepiness (EDS). The cataplectic narcolepsy differed from non-cataplectic narcolepsy by having more rapid eye movement (REM)-related clinical symptoms (more sleep paralysis and sleep-related hallucination) and sleep disturbances (shorter REM latency), as well as tighter association with HLA DQB1*0602. A bi-modal peak pattern was observed at 11 and 39 years old. A similar bi-modal pattern also occurred for EDS and cataplexy. Excess winter births were observed for this series of patients. 81% of patients with cataplectic narcolepsy were DQB1*0602-positive. There were no differences between early- and late-onset cases in the association with positive DQB1*0602 (71.4% vs 60%). Narcolepsy had prominent pernicious effects on various social, academic, family and mental aspects in our patients. CONCLUSIONS: In our Southern Chinese narcolepsy series, bi-modal peak pattern of age of onset, excess winter birth and tight association of HLA DQB1*0602 with cataplectic narcolepsy were found.

Efficient coating of transparent and conductive carbon nanotube thin films on plastic substrates.

Optically transparent and electrically conductive single-walled carbon nanotube (SWNT) thin films were fabricated at room temperature using a dip-coating technique. The film transparency and sheet resistance can be easily tailored by controlling the number of coatings. Aminopropyltriethoxysilane (APTS) was used as an adhesion promoter and, together with surfactant Triton X-100, greatly improved the SWNTs coating. Only five coats were required to obtain a sheet resistance of 2.05 [Formula: see text] and film transparency of 84 %T. The dip-coated film after post-deposition treatment with nitric acid has a sheet resistance as low as 130 [Formula: see text] at 69 %T. This technique is suitable for large-scale SWNT coating at room temperature and can be used on different types of substrates such as glass and plastics. This paper will discuss the role of the adhesion promoter and surfactant in the coating process.

Aortic dissection in an accident and emergency department in Hong Kong.

OBJECTIVES: To compare the clinical characteristics of aortic dissection in Hong Kong with the International Registry of Aortic Dissection, and to evaluate the sensitivity of the Accident and Emergency Department in diagnosing aortic dissection and its role in aortic dissection management. DESIGN: Retrospective observational study. SETTING: Regional public hospital, Hong Kong. PATIENTS: Newly diagnosed aortic dissection patients attending the Accident and Emergency Department from 2002 to 2005 inclusive. MAIN OUTCOME MEASURES: Correct diagnosis in Accident and Emergency Department, tertiary unit transfer, and in-patient mortality. RESULTS: Twenty-eight patients were found to have aortic dissection, with an estimated annual incidence of 2.1 per 100,000 inhabitants. The sensitivity of Accident and Emergency Department in diagnosing aortic dissection was 54%; 11% of the patients were diagnosed at postmortem examination. Compared to the International Registry of Aortic Dissection, the patients in this Tseung Kwan O Hospital study had less abrupt and less severe pain, less chest pain, and a lower proportion were operated on. Higher mortality was associated with age 70 years or older (odds ratio=6.4), female gender (21.0), known hypertension (3.8), systolic blood pressure below 100 mm Hg (6.0), aortic dissection not diagnosed in the Accident and Emergency Department (3.2), and the patient not reaching tertiary unit (33.8). The hourly cumulative mortality rate was 1.32%. The group of aortic dissections diagnosed in the Accident and Emergency Department had 55.1% more transfer to tertiary unit (95% confidence interval, 14.4-79.1%; P=0.006), 84.5 hours less transfer time (95.3-263.6 hours; P=0.232), and 27.2% lower mortality (12.6-58.6%; P=0.246). The yield rate of contrast computed tomography of thorax was 43%. CONCLUSIONS: Diagnosing aortic dissection in the Accident and Emergency Department enabled optimal disposition and lower in-patient mortality.