Biomedical subjects

Rui Sun

Publications and source records attributed to Rui Sun.

60 records · Page 4Linked to original sources

PubMed2003

[A review on research of land surface water and heat fluxes].

Many field experiments were done, and soil-vegetation-atmosphere transfer(SVAT) models were stablished to estimate land surface heat fluxes. In this paper, the processes of experimental research on land surface water and heat fluxes are reviewed, and three kinds of SVAT model(single layer model, two layer model and multi-layer model) are analyzed. Remote sensing data are widely used to estimate land surface heat fluxes. Based on remote sensing and energy balance equation, different models such as simplified model, single layer model, extra resistance model, crop water stress index model and two source resistance model are developed to estimate land surface heat fluxes and evapotranspiration. These models are also analyzed in this paper.

Agriculture↗

PubMed2002

Impaired natural killer (NK) cell activity in leptin receptor deficient mice: leptin as a critical regulator in NK cell development and activation.

Leptin is an adipocyte-secreted hormone that centrally regulates weight control via targeting the leptin receptor in the central nervous system. Recently, the leptin receptor has also been detected in peripheral systems including immune tissues, suggesting that leptin may play an important role in the regulation of immune function. It has been shown that leptin modulates functions of T lymphocytes, B lymphocytes, and monocytes/macrophage. However, the effect of leptin on NK cells remains unknown. In the present paper, we observed that percentage of NK cells and total amount of NK cells in the liver, spleen, lung, and peripheral blood were declined in leptin receptor deficient mice (db/db B6 mice), indicating that NK cell development was vigorously influenced by leptin receptor deficiency. Both basal and poly I:C-stimulated NK cell activation (CD69 surface marker expression) were retarded in db/db mice. In addition, leptin treatment increased the basal or synergistically enhanced IL-15- and poly I:C-induced specific lysis of splenocytes in normal littermates but not in db/db mice. Taken together, these findings suggest that leptin plays an important role in NK cell development and activation.

Animals↗

PubMed2002

The role of growth hormone in T-cell development and reconstitution.

Growth hormone (GH), directly or through GH-induction of insulin-like growth factor (IGF)-1, has been implicated in lymphocyte development and function. Recent studies have questioned the role of GH and IGF-1 in immune responses. This review examines experimental data describing the immunoregulatory function of GH and attempts to reconcile the literature.

Animals↗

PubMed2001

[Negative Regulatory Effect of T-Lymphocytes on the Expansion of Human Bone Marrow Hematopoietic Cells In Vitro]

In this research, the regulatory effects of T-lymphocytes on the expansion of hematopoietic cells in human bone marrow were studied. Anti-CD3 McAb and anti-CD8 McAb were used to eliminate the T-lymphocytes in bone marrow MNCs. Cell surface antigens were analysed by flow cytometry. Hematopoietic cells expanded with hematopoietic growth factors (HGFs) in a liquid culture system and the number of CD34(+) cell, CFU-GM and CFU-GEMM were determined. After cultured with HGFs for 20 days the total number of cells expanded by 75.8, 79.6, 77.4 and 67.0 folds respectively in three experimental groups (anti-CD3 McAb, anti-CD8 McAb and anti-CD3 + anti-CD8 McAb) and control group (MNC of bone marrow). The number of CFU-GM in the four groups were 173.67 +/- 18.90, 165.33 +/- 26.58, 170.33 +/- 21.50 and 79.67 +/- 8.33 respectively. The number of CFU-GEMM in the four groups were 431.33 +/- 34.56, 370.33 +/- 42.10, 386.67 +/- 10.02 and 177.67 +/- 26.86 respectively. There were significant differences in the number of CFU-GM and CFU-GEMM between experimental groups and control group. The results showed that the T-lymphocytes in bone marrow could inhibit the expansion of hematopoietic cells in vitro and the formation of CFU-GM and CFU-GEMM. The regulatory mechanism was to be explored.

Journal Article↗

PubMedDate not supplied

Recombinant human prolactin improves antitumor effects of murine natural killer cells in vitro and in vivo.

OBJECTIVE: To verify the effect of prolactin on natural killer (NK) cells in vivo and its implications for NK cell immunotherapy. METHODS: Recombinant human prolactin (rhPRL; 30 microg, i.p.) was administered to BALB/c mice and severe combined immunodeficiency (SCID) mice 1 day before harvesting splenocytes for (51)Cr release assay to examine the effects of rhPRL on NK cells of normal mice. rhPRL (10 microg, i.p., every other day for a total of 5 injections) was administered to BALB/c mice after syngeneic bone marrow transplantation (SBMT) to determine its effects on NK cell reconstitution. CT26 tumor cells were injected into BALB/c mice intravenously on day 0, and interleukin (IL)-15-cocultured activated syngeneic NK cells (IL-15-NK) from SCID mice were intravenously injected into tumor-bearing BALB/c mice on day 1. The improvement of antimetastasis effects and survival of tumor-bearing mice by rhPRL were checked. RESULTS: BALB/c and SCID mice receiving one rhPRL injection exhibited a significant increase in cellular cytotoxicity against YAC-1 target tumor cells; the specific lysis was enhanced from 12.5 to 17.3% in BALB/c mice and from 27.8 to 51.2% in SCID mice. BALB/c mice continuously receiving rhPRL injections exhibited significant increases in NK cell (DX5-positive) contents and cellularity in both the bone marrow and spleen in the SBMT model. The bone marrow NK cell contents were improved from 1.53 to 3.13% after rhPRL injection. NK cells from SCID mice were then cultured with recombinant human IL-15 (rhIL-15; 6000 IU/ml), rhPRL (10 ng/ml) or rhIL-15 plus rhPRL for 25 days. The cytotoxicity and cellularity were enhanced by rhPRL when tested on day 10, when comparing the rhIL-15 plus rhPRL group with the rhIL-15 group or rhPRL group, respectively. In the adoptive cellular immunotherapy study, the IL-15-NK plus IL-15 plus rhPRL group showed significantly lower numbers of lung metastases and longer survival than the IL-15-NK plus IL-15 group; the mean survival interval was prolonged from 31.5 to 53.7 days. CONCLUSION: These results indicate that rhPRL is possibly an important regulator of NK cells and a potential biologic product for immunotherapy.

Animals↗

PubMedDate not supplied

Traditional Chinese medicine Astragalus reverses predominance of Th2 cytokines and their up-stream transcript factors in lung cancer patients.

Th2 cytokine is predominant in tumor patients and was found to be associated with tumor progression. Reversing of Th2 dominant status is thought to be a promising strategy. In the present study, peripheral blood mononuclear cells (PBMNC) of 37 lung cancer patients and 19 healthy subjects were prepared and used for examination of cytokine secretion and gene expression. The positive percentage of mRNA transcripts of Th1 cytokines (8.1% for IFNgamma and 13.5% for IL-2) in patients' PBMNC were lower than those of Th2 cytokines (70.3% for IL-4, 64.9% for IL-6 and 83.8% for IL-10). The gene expression capacity (measured as relative intensity to ratio of beta-actin) of patients for Th1 cytokines was low, but constitutively relatively high for Th2 cytokines. Both positive percentage and relative intensity were lower in transcript factor for Th1 cytokine, T-bet (40.5% and 0.139, respectively) than those for Th2 cytokine, GATA3 (89.2% and 0.364, respectively). Traditional Chinese medicine, Astragalus (AG) was observed to reverse Th2 status of lung cancer. AG enhanced culture supernatant and gene expression levels of Th1 cytokine (IFNgamma and IL-2) and its transcript factor (T-bet), and reduced those of Th2 cytokines in cultured PBMNC of lung cancer patients. These results demonstrated that traditional Chinese medicine AG might reverse the Th2 predominant status in lung cancer patients, which is a probable alternative therapeutic regime in future.

Adult↗