Effects of antioxidants on survival of adult rat hepatocytes under various oxygen tensions in serum-free primary culture.

Effects of antioxidants, such as superoxide dismutase, vitamin C, vitamin E, 4-(0-benzylphenoxy)-N-methylbutylamine hydrochloride (bifemelane), and selenite on survival of adult rat hepatocytes were examined under normoxic and hyperoxic conditions in serum-free primary culture. The tested antioxidants, except for vitamin C, significantly increased the survival rate of hepatocytes under the normoxic condition (under air). Thus, even the normoxic culture condition is hyperoxic for hepatocytes. Elevation of oxygen tension (40% O2) caused severe morphologic degeneration of hepatocytes and remarkable decrease in the survival rate of the cells. Addition of the antioxidants effectively protected hepatocytes from the morphologic degeneration, and significantly improved the survival of the cells under the hyperoxic condition. These findings indicate that the antioxidants can maintain the long-term survival of hepatocytes in serum-free primary culture.</p

Selection of medium for serum-free primary culture of adult rat hepatocytes.

To select a suitable medium for serum-free primary culture of adult rat hepatocytes, ten commercially-available synthetic media were compared for their ability to maintain the cells under serum-free and serum-supplemented conditions with special reference to attachment, survival and albumin secretion. It was found that Williams' medium E and DM-160 medium were the best among the ten media for maintaining hepatocytes under serum-free conditions in primary culture.</p

Intravascular large B-cell lymphoma of the kidney: A case report

We report a 41-year-old Chinese woman with intravascular large B-cell lymphoma diagnosed by percutaneous renal biopsy. The patient was admitted to Nanfang Hospital of Southern Medical University, Guangzhou, China with complaints of high spiking fever for a month and bilateral lower limb fatigue with difficulty ambulating for the past 5 months

Karyotypic analysis in the process of immortalization of human cells treated with 4-nitroquinoline 1-oxide

The establishment of a model system of neoplastic transformation of normal human cells has been attempted with a chemical carcinogen, 4-nitroquinoline 1-oxide (4NQO). In the course of these experiments, it was noticed that immortalization of human cells is a multi-step process involving several mutational genetic events. Thus, chromosomal changes which occurred during the process of immortalization of human fibroblasts were examined. To accomplish immortalization, fibroblasts obtained from an embryo were repeatedly treated with 10-6M4NQO from primary culture to passage 51 (59 treatments in total). Before immortalization, some chromosomes (especially, chromosomes 2, 6, 8, 10, 11, 12, 15, 19, and 20), were lost at a relatively high frequency. After immortalization, the chromosomes distributed so broadly in the triploid to hypotetraploid region without a distinct modal number or without marker chromosomes that it was difficult to identify the specific chromosomes related to the immortalization of human cells. No specific structural chromosomal changes were detected. Although the significance of such chromosome changes in relation to immortalization is not clear, the loss of some specific chromosomes suggests that genes which are involved in cellular aging and which suppress immortalization may have been lost in the immortalization process.</p

Antiproliferative effects of suramin on human cancer cells in vitro and in vivo.

The present experiment was undertaken to study what types of human cancers are responsive to the antiproliferative effects of suramin. The human malignant cells used were as follows: cervical cancer (HeLa), mammary cancer (MCF-7), bladder cancer (EJ), hepatoma (HuH-7, PLC/PRF/5), embryonal carcinoma (PA-1), in vitro transformed fibroblasts (KMST-6, SUSM-1, VA-13), five myeloma cell lines (KMM-1, KMS-5, KMS-11, KMS-12, RPMI 8226), Burkitt's lymphoma (Raji), acute promyelocytic leukemia (HL-60), chronic myelocytic leukemia (K562), Epstein-Barr virus nuclear antigen positive lymphoblastoid cells (KMS-9). The cells were treated with 25 to 100 micrograms/ml suramin for 72h. Proliferation of HuH-7 and two human myeloma cells (KMS-11 and KMS-12) was remarkably inhibited, and that of PA-1, PLC/PRF/5, KMST-6, two other myeloma cell lines (KMM-1 and KMS-5), Raji and HL-60, was moderately inhibited. In order to confirm part of the results obtained from in vitro experiments, in vivo experiments were also undertaken. The growth of HuH-7 cells transplanted subcutaneously into nude mice was significantly suppressed by intravenous injection of suramin. We discussed the possibility that certain types of human cancers, the growth of which seemed to be more or less dependent on polypeptide growth factors, might be sensitive to the antiproliferative effects of suramin.</p

MicroRNA-21 regulates breast cancer invasion partly by targeting tissue inhibitor of metalloproteinase 3 expression

<p>Abstract</p> <p>Background</p> <p>MicroRNAs are non-coding RNA molecules that posttranscriptionally regulate expression of target genes and have been implicated in the progress of cancer proliferation, differentiation and apoptosis. The aim of this study was to determine whether microRNA-21 (miR-21), a specific microRNA implicated in multiple aspects of carcinogenesis, impacts breast cancer invasion by regulating the tissue inhibitor of metalloproteinase 3 (TIMP3) gene.</p> <p>Methods</p> <p>miR-21 expression was investigated in 32 matched breast cancer and normal breast tissues, and in four human breast cancer cell lines, by Taqman quantitative real-time PCR. Cell invasive ability was determined by matrigel invasion assay in vitro, in cells transfected with miR-21 or anti-miR-21 oligonucleotides. In addition, the regulation of tissue inhibitor of metalloproteinase 3 (TIMP3) by miR-21 was evaluated by western blotting and luciferase assays.</p> <p>Results</p> <p>Of the 32 paired samples analyzed, 25 breast cancer tissues displayed overexpression of miR-21 in comparison with matched normal breast epithelium. Additionally, incidence of lymph node metastasis closely correlated with miR-21 expression, suggesting a role for miR-21 in metastasis. Similarly, each of the four breast cancer cell lines analyzed overexpressed miR-21, to varied levels. Further, cells transfected with miR-21 showed significantly increased matrigel invasion compared with control cells, whereas transfection with anti-miR-21 significantly decreased cell invasion. Evaluation of TIMP3 protein levels, a peptidase involved in extarcellular matrix degredation, inversely correlated with miR-21 expression.</p> <p>Conclusion</p> <p>As knockdown of miR-21 increased TIMP3 protein expression and luciferase reporter activity, our data suggests that miR-21 could promote invasion in breast cancer cells via its regulation of TIMP3.</p

A Multiple-Phase-Shift Control for a SiC-Based EV Charger to Optimize the Light-Load Efficiency, Current Stress, and Power Quality

An ac/dc + dual-active-bridge (DAB) circuit was found as one solution for the high-efficiency and high-power-density electric vehicle charger. One control option is to let ac/dc part only convert the grid voltage to a double-line-frequency folded sine wave, yielding near-zero switching loss of the ac/dc part and leaving the DAB stage to control both power factor and power delivery. Such a zero-to-peak input voltage and wide-range output voltage can obstruct the zero-voltage switching (ZVS) for the DAB stage, which is a must for high-efficiency applications even with SiC devices. While the conventional single-phase shift loses ZVS at light load, and the variable-switching-frequency dual phase shift (DPS) creates the grid-current distortion at the light load, this paper employs multiple-phase-shifts (MPS) control, which essentially is a fixed-switching-frequency triple-phase-shift (TPS) control at light-load conditions and jumping to DPS at medium- and heavy-load conditions. While the TPS control will sacrifice the system efficiency by introducing the circulating current, a multiobjective optimization is employed to optimize the current stress and efficiency simultaneously, using the database of the double-pulse-test result. Experimental results on a SiC-based charger validated the effectiveness of the proposed control algorithm, that is: 1) high efficiency(\u3e97%) at heavy load (7.2 kW); 2) smooth sinusoidal current without bumps at zero-crossing points from the whole-load range; and 3) the smooth transition between the heavy load and light load