Newly diagnosed acute lymphoblastic leukemia in China (I): abnormal genetic patterns in 1346 childhood and adult cases and their comparison with the reports from Western countries

It has been generally acknowledged that the diagnosis, treatment and prognosis evaluation of leukemia largely rely on an adequate identification of genetic abnormalities. A systemic analysis of genetic aberrations was performed in a cohort of 1346 patients with newly diagnosed acute lymphoblastic leukemia (ALL) in China. The pediatric patients had higher incidence of hyperdiploidy and t(12;21) (p13;q22)/ETV6-RUNX1 than adults (P<0.0001); in contrast, the occurrence of Ph and Ik6 variant of IKZF1 gene was much more frequent in adult patients (all P<0.0001). In B-ALL, the existence of Ik6 and that of BCR-ABL were statistically correlated (P<0.0001). In comparison with Western cohorts, the incidence of t(9;22) (q34;q11)/BCR-ABL (14.60%) in B-ALL and HOX11 expression in T-ALL (25.24%) seemed to be much higher in our group, while the incidence of t(12;21) (p13;q22)/ETV6-RUNX1 (15.34%) seemed to be lower in Chinese pediatric patients. The occurrence of hyperdiploidy was much lower either in pediatric (10.61% vs 20-38%) or adult patients (2.36% vs 6.77-12%) in our study than in Western reports. In addition, the frequencies of HOX11L2 in adult patients were much higher in our cohort than in Western countries (20.69% vs 4-11%). In general, it seems that Chinese ALL patients bear more adverse prognostic factors than their Western counterparts do.

Reproducibility and intraindividual variation over days in buccal cell DNA methylation of two asthma genes, interferon γ (IFNγ) and inducible nitric oxide synthase (iNOS)

The biological mechanisms responsible for the onset and exacerbation of asthma symptoms in children may involve the epigenetic regulation of inflammatory genes after environmental exposures. Using buccal cells, we hypothesized that DNA methylation in promoter regions of two asthma genes, inducible nitric oxide synthase (iNOS) and interferon γ (IFNγ), can vary over several days. Repeat buccal samples were collected 4 to 7 days apart from 34 children participating in the Columbia Center for Children's Environmental Health (CCCEH) birth cohort study. Several field duplicates (sequential collection of two samples in the field) and replicates (one sample pyrosequenced twice) also were collected to ensure consistency with collection and laboratory procedures. DNA methylation was assessed by pyrosequencing a PCR of bisulfite-treated DNA. We found that replicate and field duplicate samples were correlated strongly (r = 0.86 to 0.99, P < 0.05), while repeat samples demonstrated low within-subject correlations (r = 0.19 to 0.56, P = 0.06 to 0.30). Our data reveal DNA methylation as a dynamic epigenetic mechanism that can be accessed safely and reproducibly in an inner city pediatric cohort using non-invasive buccal swabs and pyrosequencing technology.

Inclusion of celecoxib into fibrous ordered mesoporous carbon for enhanced oral bioavailability and reduced gastric irritancy

Fibrous ordered mesoporous carbon (FOMC) was developed as a new drug delivery system for loading an insoluble drug, designed to be orally administered, and then to enhance the drug loading capacity, improve the dissolution rate, enhance the oral bioavailability and reduce the gastric damage. Celecoxib (CEL) was chosen as a model drug. The nanostructures and effect of different pore sizes (4.4-7.0 nm) on drug loading and release properties were studied. The results showed that FOMC has a high drug loading capacity (0.599 g/g, drug weight/carrier weight) and the dissolution rate of CEL from FOMC was much faster than pure crystalline CEL using buffer (pH 6.8) as a dissolution medium. Moreover, the oral bioavailability of CEL loaded into FOMC was significantly improved compared with that of CEL capsules and the gastric damage caused by CEL which was loaded in FOMC was also reduced, demonstrating the protective effect of FOMC.

Cell-substrate interaction with cell-membrane-stress dependent adhesion

Cell-substrate interaction is examined in a two-dimensional mechanics model. The cell and substrate are treated as a shell and an elastic solid, respectively. Their interaction through adhesion is treated using nonlinear springs. Compared to previous cell mechanics models, the present model introduces a cohesive force law that is dependent not only on cell-substrate distance but also on internal cell-membrane stress. It is postulated that a living cell would establish focal adhesion sites with density dependent on the cell-membrane stress. The formulated mechanics problem is numerically solved using coupled finite elements and boundary elements for the cell and the substrate, respectively. The nodes in the adhesion zone from either side are linked by the cohesive springs. The specific cases of a cell adhering to a homogeneous substrate and a heterogeneous bimaterial substrate are examined. The analyses show that the substrate stiffness affects the adhesion behavior significantly and regulates the direction of cell adhesion, in good agreement with the experimental results in the literature. By introducing a reactive parameter (i.e., cell-membrane stress) linking biological responses of a living cell to a mechanical environment, the present model offers a unified mechanistic vehicle for characterization and prediction of living cell responses to various kinds of mechanical stimuli including local extracellular matrix and neighboring cells.

Three-dimensional gadolinium-enhanced MR venography to evaluate central venous steno-occlusive disease in hemodialysis patients

AIM

To determine the agreement and diagnostic accuracy of three-dimensional gadolinium-enhanced magnetic resonance venography (3D-Gd-MRV) in central venous steno-occlusive disease (CVSD) in haemodialysis patients.

MATERIALS AND METHODS

Fourteen consecutive haemodialysis patients underwent interventional procedures to evaluate or treat CVSD. 3D-Gd-MRV was performed before the procedures and the results were compared with digital subtraction angiography (DSA).

RESULTS

DSA showed >50% stenosis in all 14 patients, 13 of whom were diagnosed correctly using 3D-Gd-MRV. Moderate stenosis was missed at 3D-Gd-MRV in one case whereby the indwelling dialysis central venous catheter may have caused an artefact on the images and hindered the accuracy of the result. The sensitivity of 3D-Gd-MRV in revealing stenosis was 93% (13/14). No complications caused by contrast agent toxicity occurred in any patient.

CONCLUSION

3D-Gd-MRV employing a non-breath-hold technique is highly sensitive in the diagnosis of CVSD and may be an alternative technique to DSA for the visualization of central veins.

All-optical flip-flop operation based on asymmetric active-multimode interferometer bi-stable laser diodes

We demonstrate fast and low energy all optical flip-flop devices based on asymmetric active-multimode interferometer using high-mesa waveguide structure. The implemented devices showed high speed all-optical flip-flop operation with 25 ps long pulses. The rising and falling times of the output signal were 121 ps and 25 ps, respectively. The required set and reset pulse energies were only 7.1 fJ and 3.4 fJ, respectively.

Growth hormone stimulates protein synthesis in bovine skeletal muscle cells without altering insulin-like growth factor-I mRNA expression

Growth hormone is a major stimulator of skeletal muscle growth in animals, including cattle. In this study, we determined whether GH stimulates skeletal muscle growth in cattle by direct stimulation of proliferation or fusion of myoblasts, by direct stimulation of protein synthesis, or by direct inhibition of protein degradation in myotubes. We also determined whether these direct effects of GH are mediated by IGF-I produced by myoblasts or myotubes. Satellite cells were isolated from cattle skeletal muscle and were allowed to proliferate as myoblasts or induced to fuse into myotubes in culture. Growth hormone at 10 and 100 ng/mL increased protein synthesis in myotubes (P < 0.05), but had no effect on protein degradation in myotubes or proliferation of myoblasts (P > 0.05). Insulin-like growth factor-I at 50 and 500 ng/mL stimulated protein synthesis (P < 0.01), and this effect of IGF-I was much greater than that of GH (P < 0.05). Besides stimulating protein synthesis, IGF-I at 50 and 500 ng/mL also inhibited protein degradation in myotubes (P < 0.01), and IGF-I at 500 ng/mL stimulated proliferation of myoblasts (P < 0.05). Neither GH nor IGF-I had effects on fusion of myoblasts into myotubes (P > 0.1). These data indicate that GH and IGF-I have largely different direct effects on bovine muscle cells. Growth hormone at 10 and 100 ng/mL had no effect on IGF-I mRNA expression in either myoblasts or myotubes (P > 0.1). This lack of effect was not because the cultured myoblasts or myotubes were not responsive to GH; GH receptor mRNA was detectable in them and the expression of the cytokine-inducible SH2-containing protein (CISH) gene, a well-established GH target gene, was increased by GH in bovine myoblasts (P < 0.05). Overall, the data suggest that GH stimulates skeletal muscle growth in cattle in part through stimulation of protein synthesis in the muscle and that this stimulation is not mediated through increased IGF-I mRNA expression in the muscle.

Survival time of cardiac allografts prolonged by isogeneic BMT in mice

To find an approach to prolong the survival time of cardiac allografts in a BALB/c-to-C57/BL6 heterotopic heart transplant model and to try to figure out related chemokines and cytokines, isogeneic and allogeneic BM cells were obtained from pregnant C57/BL6 (♀C57/BL6 × ♂BALB/c) and regular BALB/c mice and injected to the half lethally irradiated C57/BL6 mice 1 day before heart transplantation. Recipients were treated with CsA or phosphate-buffered saline for 7 days. Isogeneic BMT (iBMT) from pregnant C57/BL6 mice was observed to significantly prolong the survival of BALB/c allografts and reduce the lymphocyte infiltration. Allogeneic BMT (aBMT) and iBMT both exhibited signicantly less T-cell proliferation reactivity and the similar degree of chimerism. There was no significant difference in these groups of IFN-γ and IL-4 production. The level of chemokine MIG (CXCL9) dramatically decreased in aBMT and iBMT groups compared with the control group. But there were no significant differences between aBMT and iBMT group. IL-17 and RORγ(t) (receptor-related orphan receptor) production were downregulated in iBMT recipients. These results indicate that iBMT can prolong the survival of cardiac allografts. IL-17 production downregulated in iBMT recipients. This means that iBMT may have important therapeutic implications.