Biological differences and molecular mechanism of different peripheral nerves after injury.

OBJECTIVE: The aim of the study was to analyze the apoptosis of neurons and the differences in expression of Bcl-2 and Bax protein in the neurons in the corresponding spinal cord segment after the repair of the tibial nerve (TN) and common peroneal nerve (CPN) in rats. MATERIALS AND METHODS: 126 healthy male Sprague-Dawley (SD) rats aged 7-8 weeks were randomly divided into group A (control group), group B (TN was cut and sutured), and group C (CPN was cut and sutured), with 42 rats in each group. The spinal cord tissues of rats in different groups were stained with hematoxylin-eosin (HE) on the 1st, 3rd, 7th, 14th, 21st, and 28th day after surgery; the number of neurons in anterior horn of spinal cord, axon density (AD), axon passage rate (APR), and recovery rate (RR) of muscle cell cross-sectional area (MCCA) were calculated; and differences in the expression of Bcl-2 and Bax proteins in the three groups of rats were analyzed by immunohistochemistry. RESULTS: The results showed that there was no statistically significant difference in the muscle wet weight (MWW) RR of the three groups of rats on the 14th day after the surgery (p>0.05), and the MWW RRs of rats in groups B and C were higher at the 28th day after surgery in contrast to group A (p<0.05). The number of motor neurons in the anterior horn of spinal cord in group B was higher than that in group C at the 3rd, 7th, 14th, and 21st day after surgery (p<0.05); the MWW RR, MCCA, and CSARR of rats in group B were lower than those in group C (p<0.05); the proximal AD, distal AD, and APR in group B were higher than those of group C on the 14th and 28th day after the surgery (p<0.05); and there were no positive staining results in the spinal cord tissue of rats in group A after staining. The expressions of Bcl-2 and Bax in group B were higher observably than the expressions in group C (p<0.05), which indicated that the recovery ability of TN was stronger than that of the CPN; the expression of Bcl-2 and Bax in TN was notably higher than that of the CPN. CONCLUSIONS: The expression of Bcl-2 and Bax was related to cell apoptosis and nerve regeneration after nerve injury. It provided a reference basis for clinical diagnosis and treatment of peripheral nerves.

Depletion of pre-mRNA splicing factor Cdc5L inhibits mitotic progression and triggers mitotic catastrophe.

Disturbing mitotic progression via targeted anti-mitotic therapy is an attractive strategy for cancer treatment. Therefore, the exploration and elucidation of molecular targets and pathways in mitosis are critical for the development of anti-mitotic drugs. Here, we show that cell division cycle 5-like (Cdc5L), a pre-mRNA splicing factor, is a regulator of mitotic progression. Depletion of Cdc5L causes dramatic mitotic arrest, chromosome misalignments and sustained activation of spindle assembly checkpoint, eventually leading to mitotic catastrophe. Moreover, these defects result from severe impairment of kinetochore-microtubule attachment and serious DNA damage. Genome-wide gene expression analysis reveals that Cdc5L modulates the expression of a set of genes involved in the mitosis and the DNA damage response. We further found that the pre-mRNA splicing efficiency of these genes were impaired when Cdc5L was knocked down. Interestingly, Cdc5L is highly expressed in cervical tumors and osteosarcoma. Finally, we demonstrate that downregulation of Cdc5L decreases the cell viability of related tumor cells. These results suggest that Cdc5L is a key regulator of mitotic progression and highlight the potential of Cdc5L as a target for cancer therapy.

Gankyrin promotes breast cancer cell metastasis by regulating Rac1 activity.

Tumor metastasis is responsible for most cancer patients' deaths. Understanding the mechanism of metastasis is crucial for improving the cure rate for cancer. Here, we report that Gankyrin, a chaperone of ubiquitin-proteasome, has an essential role in breast cancer metastasis. We find that Gankyrin is highly overexpressed in human breast cancers and the expression correlates strongly with lymph node metastasis. Knocking down Gankyrin expression in highly metastatic human breast cancer cells significantly decreases cancer cell migration and invasion. Furthermore, we demonstrate that depletion of Gankyrin inhibits intrinsic Rac1 activity and induces large focal adhesions. Overexpression of Gankyrin accelerates focal adhesion turnover and increases cell migration. Notably, reduction of Gankyrin expression in mouse mammary tumor cell significantly decreases tumor metastasis to lung in animal models. Therefore, our findings suggest that Gankyrin is crucial for breast cancer metastasis and highlight the potential of Gankyrin as a therapeutic target for tumor metastasis.

Tumor-targeted delivery of biologically active TRAIL protein.

The tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a potent inducer of tumor cell apoptosis, but concerns of considerable liver toxicity limit its uses in human cancer therapy. Here, we show that i.v. injected Escherichia coli DH5alpha (E. coli DH5alpha) specifically replicates in solid tumors and metastases in live animals. E. coli DH5alpha does not enter tumor cells and suits for being the vector for soluble TRAIL (sTRAIL), which induces apoptosis by activating cell-surface death receptors. With the high 'tumor-targeting' nature, we demonstrate that intratumoral (i.t.) and intravenous injection of sTRAIL-expressing E. coli DH5alpha results in the tumor-targeted release of biologically active molecules, which leads to a dramatic reduction in the tumor growth rate and the prolonged survival of tumor-bearing mice. TRAIL delivery by E. coli DH5alpha did not cause any detectable toxicity to any organs, suggesting that E. coli DH5alpha-delivered sTRAIL protein therapy may provide a feasible and effective form of treatment for solid tumors.

Feasibility of using ultrasonic irradiation to recover active biomass from waste activated sludge.

Under typical operating conditions, the microbial fraction of activated sludge flocs is approximately 40% by weight. The objective of this research is to evaluate the feasibility of using ultrasonic irradiation to disrupt activated sludge flocs allowing for the subsequent separation of active and inactive fractions. If separation of floc components is possible, then methods may be incorporated into wastewater treatment plant operations whereby only the inactive fraction of floc is wasted (i.e., of waste activated sludge, WAS), which in turn could increase the overall effective biological solids retention time, leading to increased process robustness with no net increase in reactor size. The results indicate that ultrasonic irradiation of WAS at 800 Wl(-1) followed by 30 min of settling can produce a supernatant with heterotrophic specific oxygen uptake rates (SOURs) of over two times the SOUR measured in the bulk mixed liquor. Under these conditions 26% of the initial heterotrophic activity was recovered within only 11% of the initial volatile mass. Similarly, autotrophic analysis revealed that nitrifying organisms, while sensitive to the effects of ultrasonic irradiation, can be separated from the activated sludge floc and recovered. An irradiation density of 200 Wl(-1) with an exposure time between 1 and 2 min produced a supernatant with a specific ammonia removal rate of over two times the initial mixed liquor rate.

Preliminary research on the p53 gene rearrangements in the evolution of chronic myelogenous leukemia to blast crisis.

DNA from 36 patients with chronic myelogenous leukemia (CML) at various clinical stages and 6 cases of acute leukemia was investigated for alterations of the p53 gene by Southern blot analysis. Rearrangements of the p53 gene were seen in 3 of 12 (25.00%) cases of blast crisis and accelerated phase (AP) of CML and in only one of 18 chronic phrase (CP), just as has been reported previously. Meanwhile, by restriction fragment length polymorphism (RFLP) analysis the Bgl II site polymorphism in the p53 gene was also found. The frequency in Chinese people detected here was 0.392, which was strikingly higher than that in some other countries (P < 0.001). These results suggested that the alterations of the p53 gene, for example, p53 rearrangements, were probably responsible for the progression of BC in some CML patients, and that the frequency of Bgl II polymorphism in the p53 gene might be related to the population distribution.

Simultaneous determination of iron(III) and vanadium(V) by use of a kinetic-spectrophotometric and rapid mixing flow system.

The quantitative spectrophotometric determination of V(V) by its catalytic effect on the oxidation of chromotropic acid [the disodium salt of 4,5-dihydroxynaphthalene-2,7-disulphonic acid (CS)] by potassium bromate has been adapted to a flow system employing a rapid sample and reagent introduction manifold, in which valves and carrier streams are omitted without decreasing the precision or increasing the sample consumption relative to flow-injection analysis (FIA). Measurements are made at 420 nm. Coexisting Fe(III) can be determined simultaneously at the same wavelength by its more rapid colour chelate formation with CS. An accurate determination of V(V) and Fe(III) in the mixture was developed with a sample throughput of about 60 hr.

BCR rearrangements in Ph positive chronic myelocytic leukemia.

Nine patients with chronic myelocytic leukemia (CML) and 1 patient with erythroleukemia were studied with 3'bcr and 5'bcr probes using Southern blot hybridization technique. Bcr rearrangements were detected in 8 patients with CML in the chronic phase, and bcr rearrangement was deduced to have existed in a CML patient in blastic crisis. However, no abnormal fragment was found in the patient with erythroleukemia. 3'bcr and 5'bcr probes combined with proper restriction enzymes were believed to be of great value in determining bcr rearrangements in Ph positive CML.

Cytogenetic study on acute lymphoblastic leukemia.

During 1987-1988 cytogenetic studies were performed in 30 patients with acute lymphoblastic leukemia (ALL). Of the 30 patients 15 (10 children and 5 adults) were found to have abnormal karyotypes including 8 cases (27%) of pseudodiploidy, 2 cases (7%) of hypodiploidy, one case (3%) of low-hyperdiploidy (modal number 47-50), and 4 cases (13%) of high-hyperdiploidy (modal number greater than 50). Immunological classification was performed by using monoclonal antibodies in 26 patients, and the most common immunophenotype was C-ALL. The patients with abnormal karyotypes were more likely to be NuLL-ALL (6 in 14) as compared with patients with normal karyotype (1 in 12). In our series, there was no significant difference between the patients with and without cytogenetic changes in regard of clinical findings such as FAB classification, the rate of complete remission, percentage of lymphoblasts in bone marrow cells and blood picture.