[Mediator effect analysis of the trait coping style on job stress and fatigue of the military personnel stationed in plateau and high cold region]

Objective: To investigate the fatigue status of military personnel stationed in plateau and high cold region, and to analyze the mediator effect of trait coping style on job stress and fatigue. Methods: In October 2010, with the method of cluster random sampling survey, 531 military personnel stationed in plateau and high cold region were chosen as subject. The fatigue status were evaluated by the Chinese version multidimensional fatigue inventory (MFI-20) , job stress were evaluated by the Job Stress Survey (JSS) , and trait coping style were evaluated by the Trait Coping Style Questionnaire (TCSQ) . Results: According to the information of different population characteristics, mean rank of physical fatigue about the urban (town) group were higher than that of rural group (Z=-2.200, P<0.05) ; mean rank of reduced motivation about the urban (town) group were higher than that of rural group (Z=-2.781, P<0.05) ; mean rank of general fatigue scores about the urban (town) group were higher than that of rural group (Z=-3.026, P<0.05) ; mean rank of physical fatigue about the up or equal 20-years old age group were higher than that of below 20-years old age group (Z=-4.045, P<0.05) ; mean rank of reduced motivation about the up or equal 20-years old age group were higher than that of below 20-years old age group (Z=-2.182, P<0.05) ; mean rank of mental fatigue about the up or equal 20-years old age group were higher than that of below 20-years old age group (Z=-2.879, P<0.05) ; mean rank of general fatigue scores about the up or equal 20-years old age group were higher than that of below 20-years old age group (Z=-3.647, P<0.05) ; mean rank of reduced motivation were significant statistical difference among the military officers, sergeancy and soldier group (F=18.965, P<0.05) ; mean rank of general fatigue scores were significant statistical difference among the military officers, sergeancy and soldier group (F=14.711, P<0.05) . The score of negative coping style were positively correlated with the score of physical fatigue (r(s)=0.129) , reduced activity (r(s)=0.123) , reduced motivation (r(s)=0.149) and general fatigue (r(s)=0.174) respectively, the score of organizational support lack strength were positively correlated with the score of physical fatigue (r(s)=0.090) , reduced activity (r(s)=0.098) , reduced motivation (r(s)=0.099) and general fatigue (r(s)=0.130) respectively. The mediator effect of negative coping style on the job stress and fatigue was 0.013 (P<0.01) . Conclusion: The fatigue statuses of the urban (town) group and the up or equal 20-years old age group are poor, and the negative coping style plays mediator effect on the job stress and fatigue.

Direct bioconversion of raw corn stalk to hydrogen by a new strain Clostridium sp. FS3

A new strain FS3 which could achieve an efficient bioconversion of raw corn stalk to hydrogen had been isolated from anaerobic acclimated sludge, and identified as Clostridium butyricum on the basis of a series of physiological and biochemical experiments and 16S rDNA gene sequence. The strain could utilize various carbon sources to produce hydrogen. On the basis of single-factor experiments, the response surface methodology (RSM) was performed to optimize the media for hydrogen production. The maximum hydrogen yield of 92.9ml/g was observed under the optimal conditions: 20g/l raw corn stalk, 1.76g/l NH4HCO3, 0.91g/l KH2PO4 and 10.4ml/l nutrient solution. This finding opens a new avenue for direct conversion of raw cellulosic biomass to bio-hydrogen.

[Degenerate PCR and its application in gene cloning]

Degenerate PCR is introduced in this paper, including what is degenerate PCR, how to design degenerate primers, how to optimize degenerate PCR parameters, how to applying degenerate PCR to obtain full-length gene and which fields can apply degenerate PCR. The limits and recent advances of degenerate PCR are also discussed. Based on this introduction,strategies of gene cloning and applications of degenerate PCR in gene cloning are summarized in brief. Degenerate PCR is a very useful tool for searching and discovering new genes and new members of a protein family.

[Effects of cytochalasin B upon mitosis of Physarum polycephalum]

Cytochalasin B, known as a functional inhibitor of actin, was microinjected into naturally synchronous plasmodia of Physarum polycephalum, and the mitotic behaviours of both CB-treated specimens and the control were examined with light and electron microscopy. Mitosis in the CB-treated specimens began about 20 to 60 minutes later than that of the control. It was delayed 35 minutes in the specimens treated with CB in the S phase of the cell cycle, and the delayed time was 20 minutes and 45 minutes, respectively. In the specimens treated with CB in early and middle G2 phase, the longest delay was 60 minutes found in the specimens treated in late G2 phase, indicating that mitosis was affected in Physarum polycephalum when the function of actin was inhibited by CB treatment. The CB-treated specimens and the control showed similarities in the process of mitosis and dynamic changes of nuclear structures, suggesting that the main effect of CB treatment upon mitosis may be to delay the triggering of the mitosis.

Characterization of two clones isolated from the TC-1 murine marrow stromal cell line: growth factor and retrovirus production and physical support of hemopoiesis

We previously reported the isolation of an adherent murine marrow cell line termed TC-1, and the initial characterization of two subclones derived from this line. In this study we report a further characterization of two subclones from the non-cloned TC-1 cell line. One subclone, TC-1-C-3, consisted of large, slow-growing syncytial polypoid cells that grew to relatively low saturation densities, did not form colonies in soft agar and showed desmosome-like junctions. The other subclone, TC-1-C-11, consisted of smaller, rapidly growing fibroblast-like diploid cells which showed anchorage-independent growth in soft agar. Both these subclones produced growth factors which stimulated giant macrophage colonies in soft agar culture in vitro, but only the TC-1-C-3 subclone produced a retrovirus, whose source was most likely the endogenous ecotropic Emv-2 provirus present in chromosomal DNA in C57BL mice. This retrovirus from the TC-1-C-3 subclone did not appear capable of transforming TC-1-C-11 cells. Together, these data suggest that TC-1-C-3 cells have a special capacity for supporting hemopoiesis. The question of whether the mechanism of this support relates to an intrinsic property of the cell or is possibly related to retrovirus production remains unanswered.

Multilineage synergistic activity produced by a murine adherent marrow cell line

We reported previously that a cell line (TC-1) derived from adherent marrow cells produced colony-stimulating factor 1 (CSF-1) and a separate activity that acts synergistically with CSF-1 to stimulate giant macrophage colonies. We now report that an activity in TC-1 conditioned media (CM) separate from CSF-1 also synergizes multilineage colony formation by pure interleukin 3 (IL 3) and a crude source of granulocyte-macrophage colony-stimulating activity (GM-CSA) (murine lung-conditioned media). IL 3-induced megakaryocyte colony formation is also synergized. The CSF-1-dependent synergistic activity is not blocked by antibodies to IL 3 and is characterized as a nondialyzable (mol wt cutoff 3,000), heat-stable (56 degrees C, 30') activity that binds to DE-52 cellulose under conditions in which IL 3 does not. This material has an apparent mol wt of approximately 200,000 by Sephadex G100 chromatography, and the bulk of it binds to Concanavalin A (Con A) and elutes off with alpha-methyl mannoside, indicating that it is a glycoprotein. As reported separately, these purified active fractions also have a pre-B cell-inducing activity. In addition, a non-IL 3 activity stimulates proliferation of the factor-dependent cell lines FDC-P1 and DA-1. These data indicate that an adherent marrow cell line produces a growth factor(s) that synergizes with IL 3, GM-CSA, and CSF-1 and induces pre-B cell formation. This may be an important regulator of early multilineage lymphohemopoiesis.

Hematopoietic factor production by a cell line (TC-1) derived from adherent murine marrow cells

An adherent cell line, termed TC-1, has been isolated from long-term liquid culture of murine marrow cells by repeated exposure of the adherent cells to 0.1% trypsin. This is an alkaline phosphatase-positive cell line showing variable staining with acid phosphatase and alpha-naphthyl acetate esterase. On electron microscopy, the cells have moderate amounts of rough endoplasmic reticulum and variable numbers of polyribosomes. Some cells contain large clusters of laked glycogen particles. Intermediate junctions are present between some cells. Conditioned medium from this cell line produced from 384 to 638 units of CSF-1 per milliliter by radioimmunoassay and a CSF-1-dependent synergistic activity, which stimulates giant macrophage colony formation of marrow cells in soft agar. The conditioned medium also stimulates 3H-TdR incorporation by marrow cells in liquid culture and induces secondary adherent cell lines. The growth factor(s) produced by the TC-1 stromal cell line may be important in the regulation of early stages of hematopoietic differentiation. Two subclones, TC-1-C-11 and TC-1-C-3, have been isolated from passage 25 of the TC-1 cells by a penicylinder separation technique. The TC-1-C-11 is phenotypically like the parent TC-1 line and produces macrophage growth factors. The TC-1-C-3 grows as an epithelioid monolayer with visible junctions among adjacent cells under phase contrast microscopy. This subclone produces retrovirus and is capable of providing anchorage support for hematopoietic stem cells. The TC-1 cell line and its subclones may provide models for the control of early stem cell proliferation and differentiation.

Radioresistant murine marrow stromal cells: a morphologic and functional characterization

Two types of murine marrow adherent cells derived from Dexter cultures have been characterized. Exposure of C57B1/6J, ICR, or BDF1 mice to 1000 R x-ray 24 h prior to killing and establishment of liquid marrow cultures resulted in the growth of two types of adherent cells. A macrophage-like cell was phagocytic, nonspecific esterase, and acid phosphatase, positive and alkaline phosphatase, myeloperoxidase, and factor-VIII negative. The second cell was large and epithelioid in appearance, had a subpopulation of giant fat cells, was nonphagocytic, alkaline phosphatase positive, and negative for acid phosphatase, nonspecific esterase, myeloperoxidase, and factor VIII. At low inoculum levels these cells formed three types of colonies within 1-3 weeks--macrophage, epithelioid, and mixed--while at higher inoculum levels they formed confluent monolayers. These radioresistant cells supported myeloid pluripotent stem cells (CFU-S) and granulocyte-macrophage stem cells (GM-CFU-C) in liquid culture of long term nonadherent marrow cells and stimulated GM-CFU-C in agar over-lays. Refeeding liquid cultures with nonadherent cells from long-term Dexter cultures revealed that myeloperoxidase-positive cells adhered predominantly to the colonies containing epithelioid cells.