Strain Differences of Macrophage Distribution in the Experimental Colorectal Cancer Model

論文Original PaperColorectal cancer (CRC) is one of the most common forms of malignancy in humans. Patients with long-standing ulcerative colitis (UC) have an increased risk for developing CRC compared to the general population. For investigation of the mechanisms and prevention of UC, and UC-related CRC, we first induced UC by DSS and then induced CRC by DMH. It took only 3 months to found the CRC model in Wister rats. The important similarities of the model may be seen in the clinical and pathological findings in animals and patients with CRC developing from UC. It is especially suited to the study of UC and CRC. In this study the mean percent of ED1, and ED3 positive macrophages in Wistar rats was higher than that in DA and Lewis rats (p < 0.05). The mean percent of Marl, and Mar3 positive macrophages in DA and Lewis rats was higher than that in Wistar rats (p < 0.05). These results suggested that the existence of four types of macrophages may play an important role in inducing colitis and rectal cancer. Furthermore, the mechanisms of strain difference in the experimental models are discussed

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Temporal dynamics of fine root production, mortality and turnover deviate across branch orders in a larch stand.

Fine roots play a key role in carbon, nutrient, and water biogeochemical cycles in forest ecosystems. However, inter-annual dynamics of fine root production, mortality, and turnover on the basis of long-term measurement have been less studied. Here, field scanning rhizotrons were employed for tracking fine root by branch order over a 6&nbsp;years period in a larch plantation. For total fine roots, from the first- to the fifth-order roots, annual root length production, length mortality, standing crops, and turnover rate varied up to 3.4, 2.3, 1.5, and 2.3-folds during the study period, respectively. The inter-annual variability of those roots indices in the first-order and the second-order roots were greater than that of the higher order (third- to fifth-order) roots. The turnover rate was markedly larger for the first-order roots than for the higher order roots, showing the greatest variability up to 20&nbsp;times. Seasonal dynamics of root length production followed a general concentrated pattern with peak typically occurring in June or July, whereas root length mortality followed a general bimodal mortality pattern with the dominant peak in May and the secondary peak in August or October. Furthermore, the seasonal patterns of root length production and mortality were similar across years, especially for the first-order and the second-order roots. These results from long-term observation were beneficial for reducing uncertainty of characterizing fine root demography in consideration of large variation among years. Our findings highlight it is important for better understanding of fine root dynamics and determining root demography through distinguishing observation years and root branch orders

Mesenchymal Stem Cells Recruit Macrophages to Alleviate Experimental Colitis Through TGFβ1

Background/Aims: Transplantation of mesenchymal stem cells (MSCs) has been shown to alleviate dextran sulfate sodium (DSS) -induced colitis through modulation of transforming growth factor β (TGFβ) receptor signaling. However, the exact molecular mechanisms are not known. Methods: Here, we transplanted primary mouse MSCs or injected TGFβ1 into mice with DSS-induced colitis. Cells were purified by flow cytometry. Gene expression was analyzed by RT-qPCR. Results: We found that MSCs significantly alleviated the DSS-induced colitis, and the major sources for TGFβ1 were macrophages that were recruited by MSCs. Specific ablation of macrophages completely abolished the anti-inflammatory effects of MSCs. On the other hand, TGFβ1 administration, without the presence of MSCs, was sufficient to reduce the severity of DSS-induced colitis. Conclusions: Taken together, our data suggest that MSCs transplantation may recruit macrophages to produce TGFβ1, which mitigates the pathology of colitis. Thus, MSCs transplantation appears to be a promising therapy for severe enteritis

Advances in the Multiphase Vortex-Induced Vibration Detection Method and Its Vital Technology for Sustainable Industrial Production

Fluid-induced vibration detection technology for the multiphase sink vortex can help achieve efficient, safe, and low-carbon sustainable industrial production in various areas such as the marine, aerospace, and metallurgy industries. This paper systematically describes the basic principles and research status in light of the important issues related to this technology in recent years. The primary issues that occur in practical application are highlighted. The vital technologies involved, such as the vortex-formation mechanism, interface dynamic evolution, the shock vibration response of thin-walled shells, and vortex-induced vibration signal processing algorithms, are analyzed. Based on in-depth knowledge of the technology, some significant scientific challenges are investigated, and further research prospects are suggested. The research results show that this technology can achieve the real-time detection of vortex-induced vibration states. Two future research directions are those of exploring multiphysical field coupling under harsh conditions and more accurate modeling methods for multiphase coupling interfaces. Regarding vortex-induced vibration, forced-vibration characters with various restriction conditions, the forced-vibration displacement response of liquid-filled shells, intrinsic properties influenced by random excitation forces, and highly effective distortion-detection algorithms will continue to attract more attention. The associated results could give technical support to various fields, including energy-efficiency improvement in manufacturing processes, tidal power generation condition monitoring, and the performance optimization of low-carbon energy components