Omental milky spots in screening gastric cancer stem cells

The existence of cancer stem and progenitor cells in solid tumors has been widely postulated. However, neither the cancer stem cells nor the cancer progenitor cells have been definitively identified and functionally characterized. Here we propose a new strategy to identify and isolate gastric cancer stem cells -using omental milky spots to screen gastric cancer stem cells in peritoneal metastasis mouse models of gastric cancer. In this study, we used the property that the macrophages in omental milky spots are cytotoxic against tumor cells and so able to screen and collect cancer stem cells. Our findings suggest that macrophages in omental milky spots have not only cytotoxic properties against tumor cells but also provide a microenvironment within milky spots in which cancer stem cells are capable to survive and grow into micrometastasis. Omental milky spot become a cancer stem cell niche in this situation. Further we studied the omental milky spots for screening gastric cancer cells (OMSS-GCCs) and found that omental milky spot enriched the volume of gastric cancer stem cells. Tumors were consistently generated after an injection of 1×103 OMSS-GCCs. OMSS-GCCs high express CD133 and low express CD324. Omental milky spots are a highly efficient "natural filter" for screening gastric cancer stem cells.

A genome-wide association study for quantitative traits in schizophrenia in China

Few genome-wide association studies (GWAS) of schizophrenia have included Chinese populations, and verification of positive genetic findings from other ethnic groups is rare in Chinese groups. We used fluid intelligence as the quantitative trait reflecting schizophrenia dysfunction in Chinese populations, and determined the impact of genetic variation on fluid intelligence phenotypic patterns to identify genetic influences in schizophrenia. The study sample comprised 98 patients with schizophrenia and 60 healthy controls. The general fluid intelligence of participants was assessed with Cattell's Culture-Free Intelligence Test (CCFIT). Subjects were genotyped using the Illumina HumanHap 660 beadchip. We identified the methionine sulfoxide reductase A (MSRA) gene on chromosome 8 as having an association with fluid intelligence. However, only CCFIT subtest 1 (series score) demonstrated a significant result for the interaction term using the criteria of the quantitative trait (QT) analysis of 10(-5) for at least three SNPs. There were 15 haplotype blocks of MSRA gene SNPs identified using Haploview 4.2 with solid spine D' > 0.80. The strongest QT interaction was noted in Block 3, with the most common haplotypes being AAACAGCAG and CGCAGAAGA. In conclusion, we report data from a GWAS with quantitative traits design from Chinese first-episode schizophrenia patients and matched controls. Although the gene identified requires confirmation in an independent sample, the MSRA gene located on chromosome 8 was found to be associated with the phenotype of schizophrenia.

High density and scale-up cultivation of recombinant CHO cell line and hybridomas with porous microcarrier Cytopore

Using porous microcarrier Cytopore and a low-serum medium supplement BIGBEF-3, we have successfully cultivated recombinant CHO cell line CL-11G producing prourokinase and hybridomas producing anti-prourokinase monoclonal antibody in Celligen 1.5 or 5 L bioreactor. The cell density obtained ranged from 1 to 2 x 107 cells mL-1. The yields of prourokinase and monoclonal antibody increased with increasing cell density. As the cells could spontaneously release from and reattach to porous microcarriers, it was very easy to scale-up the cultivation. Thus the bead to bead cell transfer method has been used to scale up the cultivation of CL-11G cells to a 20 L reactor-scale for the pilot production of prourokinase, and also to scale-up the culture of hybridomas for the production of monoclonal antibody for the purification of prourokinase.

Pilot production of u-PA with porous microcarrier cell culture

A recombinant DNA CHO cell line secretingurokinase-type plasminogen activator (u-PA) wascultivated with Cytopore cellulose porousmicrocarriers in a 30l Biostat UC stirred tankreactor. After 26 days of culture, using a spinfilter toretain cells in bioreactor, the cell density couldreach 1.33 x 10(7) ml(-1). The maximal u-PAactivity in supernatant was 7335 IU.ml(-1), and204l supernatant containing 7.1 g u-PA was harvested.After 100 days of culture with 0.1% fetal bovineserum medium, a modified cell retention system whichcan be washed-out backward, substituted thespinfilter to prevent filter clogging. The maximalcell density was over 10(7) ml(-1), the maximalu-PA activity in supernatant reached 6250IU.ml(-1), and 1604l supernatant containing about51 g u-PA was harvested. Compared to perfusionculture, batch medium-replaced culture could raiseutilizing efficiency of the medium, increase cell specificproductivity and improve the quality of the product which wasnot steady in a 37 degrees C environment. Cells can movefrom seed porous microcarriers occupied by cells tovacant microcarriers spontaneously, withouttrypsinization, and continue to grow until all microcarriers contained cells. It shows that Cytoporeporous microcarriers are very useful and convenient toscale up cultivation step by step.

Cdc2: a monopotent or pluripotent CDK?

Cell cycle progression is controlled by both extracellular and intracellular signalling molecules. It has been generally believed that cdc2/CDK1 only control G(2)-M transition in mammalian and many other higher eukaryotic cells. Accumulating evidence shows that cdc2 not only promotes G(2)-M transition but is also capable of regulating G(1) progress and G(1)-S transition via association with multiple interphase cyclins; cdc2 activity can be inhibited by p21 and p27, two traditional G(1) CDK inhibitors. In addition, cdc2-cyclin B controls pronuclear union in interphase fertilized eggs. These data suggest that cdc2 may be a pluripotent CDK. Although mechanisms responsible for the multiple functions of cdc2 remain to be further investigated, interactions of cdc2 with pRb and with several important transcription factors may provide a clue to the pluripotent role of cdc2.

Effects of enrofloxacin on cytochromes P4501A and P4503A in Carassius auratus gibelio (crucian carp)

Currently, although enrofloxacin (EF) as a widely used veterinary medicine has begun to apply to treating fish bacterial infections, the researches on the effects of EF on their main drug metabolic enzymes are limited. To investigate the effects of EF on fish cytochromes P450 (CYPs) 1A and 3A, the enzymatic activities and expressions (mRNA and protein) of crucian carp CYP1A and CYP3A after EF administration were examined. For CYP1A, in the in vivo experiments, EF exhibited potent inhibition on the CYP1A-related ethoxyresorufin-O-deethylase (EROD) activity, as well as CYP1A expressions at both protein and mRNA levels, at 24 h after administration with different EF dosages (3, 10, 30, and 60 mg/kg); Furthermore, CYP1A enzymatic activity and expressions at both protein and mRNA levels decreased more with increasing EF dosages. Additionally, the in vitro experimental results showed that, after incubated with microsomes, EF did not change the EROD activity through interacting directly with CYP1A. For CYP3A, the in vitro and in vivo experimental results demonstrated that EF could inhibit the CYP3A-related erythromycin N-demethylase activity in a time- and dose-dependent manner, while it did not suppress CYP3A expressions at both protein and mRNA levels after administration with EF for a short period (no more than 24 h); however, after injection with EF at a high dose (10 mg/kg) for a long period, the CYP3A protein and mRNA reached their lowest levels at 96 and 48 h, respectively. These results indicate that EF can suppress CYP1A expressions in a dose-dependent manner, thereby inhibiting further its catalytic activity; meanwhile, both the interactions of EF with CYP3A and the expressions decrease (protein and mRNA) caused by EF contribute to the CYP3A inhibition.

Interleukin-21 is upregulated in hepatitis B-related acute-on-chronic liver failure and associated with severity of liver disease

The immune mechanism(s) that lead to hepatitis B-related acute-on-chronic liver failure (HB-ACLF) are poorly understood. Interleukin-21 is a newly discovered cytokine that is involved in autoimmune and inflammatory diseases. Its potential role in HB-ACLF remains unknown. The serum levels of 12 immune cytokines measured by cytometric bead arrays and the frequency of IL-21-secreting CD4+ T cells in peripheral blood mononuclear cells (PBMC) measured by intracellular cytokine staining were compared in moderate chronic hepatitis B (M-CHB, n = 20), severe chronic hepatitis B (S-CHB, n = 20), HB-ACLF (n = 39) and healthy controls (n = 10). PBMC from M-CHB patients or healthy subjects were stimulated with rhIL-21 in vitro, and cytokines in supernatants were measured by FlowCytomix. The frequencies of IL-21-secreting CD4+ T cells were higher in HB-ACLF (both P < 0.001) and S-CHB (P = 0.002 and 0.001) as compared to M-CHB patients and controls. Serum IL-21 levels were highest (P < 0.001) in HB-ACLF and positively associated with high MELD score (P = 0.001) and mortality (P = 0.038). Recovery from HB-ACLF was associated with reduced serum IL-21 levels (P = 0.003) and lower CD4+ IL-21(+) T-cell frequency (P = 0.006). The secretions of IL-1β (P < 0.001), IL-6 (P < 0.001), IL-10 (P < 0.001), IFN-γ (P = 0.001) and TNF-α (P = 0.042) from PBMC were significantly increased with rhIL-21 stimulation. In summary, IL-21 has a causal role in the development of severe liver inflammation, which is upregulated in HB-ACLF and associated with severity of liver disease.

Group velocity manipulation in active fibers using mutually modulated cross-gain modulation: from ultraslow to superluminal propagation

We propose and experimentally demonstrate the propagation of slow/fast light in an erbium-doped fiber (EDF) using mutually modulated cross-gain modulation. The group velocity of the light signal can be manipulated by the effect of gain cross-saturation modulation by a saturating light at an arbitrary wavelength in the gain bandwidth of the EDF. The ultraslow propagation with a small group velocity of 5.6 × 10⁻³c (c is the light speed in free space) and superluminal propagation with a negative group velocity of -1.1 × 10⁻³c has been observed under different modulation phases.

Ursolic acid promotes robust tolerance to cardiac allografts in mice

Nuclear factor (NF)-κB is an important molecule in T cell activation. Our previous work has found that T cell-restricted NF-κB super-repressor (IκBαΔN-Tg) mice, expressing an inhibitor of NF-κB restricted to the T cell compartment, can permanently accept fully allogeneic cardiac grafts and secondary donor skin grafts. In this study, we explore if transient NF-κB inhibition by a small molecular inhibitor could induce permanent graft survival. Ursolic acid, a small molecular compound, dose-dependently inhibited T cell receptor (TCR)-triggered NF-κB nuclear translocation and T cell activation in vitro. In vivo, ursolic acid monotherapy prolonged significantly the survival of cardiac allograft in mice. Assisted with donor-specific transfusion (DST) on day 0, ursolic acid promoted 84·6% of first cardiac grafts to survive for more than 150 days. While the mice with long-term surviving grafts (LTS) did not reject the second donor strain hearts for more than 100 days without any treatment, they all promptly rejected the third-party strain hearts within 14 days. Interestingly, this protocol did not result in an increased proportion of CD4(+) CD25(+) forkhead box P3(+) regulatory T cells in splenocytes. That adoptive transfer experiments also did not support regulation was the main mechanism in this model. Splenocytes from LTS showed reduced alloreactivity to donor antigen. However, depletion of CD4(+) CD25(+) regulatory T cells did not alter the donor-reactivity of LTS splenocytes. These data suggest that depletion of donor-reactive T cells may play an important role in this protocol.

Simultaneous acquisition of gradient echo/spin echo BOLD and perfusion with a separate labeling coil

Arterial spin labeling-based cerebral blood flow imaging complements blood oxygenation level dependent (BOLD) imaging with a measure that is more quantitative and has better specificity to neuronal activation. Relative to gradient echo BOLD, spin echo BOLD has better spatial specificity because it is less biased to large draining veins. Although there have been many studies comparing simultaneously acquired cerebral blood flow data with gradient echo BOLD data in fMRI, there have been few studies comparing cerebral blood flow with SE BOLD and no study comparing all three. We present a pulse sequence that simultaneously acquires cerebral blood flow data with a separate labeling coil, gradient echo BOLD, and spin echo BOLD images. Simultaneous acquisition avoids interscan variability, allowing more direct assessment and comparison of each contrast's relative specificity and reproducibility. Furthermore, it facilitates studies that may benefit from multiple complementary measures.