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Biomedical subjects

Lan Sun

Publications and source records attributed to Lan Sun.

At least 19 recordsLinked to original sources
PubMed2006

[Intraperitoneal chemotherapy with mitomycin C bound to activated carbon nanoparticles for nude mice bearing human gastric carcinoma].

OBJECTIVE: To prepare a new dosage formulation of activated carbon nanoparticles adsorbing mitomycin C (MMC-ACNP) and evaluate the beneficial effects of intraperitoneally applied MMC-ACNP as a drug delivery system for lymphatic targeting in preventing metastasis and recurrence of gastric cancer. METHODS: MMC-ACNP was prepared. Acute toxicity after its intraperitoneal administration was evaluated. An experiment on nude mice model with transplanted human gastric cancer in 6 groups was completed to assess the effects of drugs on intra-abdominal carcinomatosis. RESULTS: The LD50 of MMC-ACNP was 46.80 mg/kg (in terms of MMC) while that of MMC aqueous solution was 9.33 mg/kg. The toxicity of MMC-ACNP was much less than that of the solution form. MMC-ACNP was superior to MMC aqueous solution in controlling carcinomatosis and tumor growth by intraperitoneal administration. Despite the high dose of MMC, leukopenia and thrombocytopenia were not observed in the MMC-ACNP treated group. Fine activated carbon particles adsorbing MMC entered the nuclei of tumor cells, so that the effects of the anticancer drug were reinforced. CONCLUSION: MMC-ACNP gives a good promise of clinical use due to its advantages such as high selectivity and low toxicity.

Adenocarcinoma, Mucinous↗
PubMed2005

Acupuncture therapy for experimental stomach ulcer and c-Fos expression in rats.

AIM: To determine the role of acupuncture therapy in treating experimental gastric ulcer in rats. METHODS: Twenty-eight adult male Sprague-Dawley rats were randomly divided into four groups (pre-acupuncture group; acupuncture group; paradistance-acupuncture group; and control group), and pre-acupuncture, paradistance-acupuncture, and control groups received 5 muL acetic acid (200 mL/L HAc) injection after a same course of electroacupuncture (EA) treatment (4 Hz, 0.6 mA, 0.45 ms, 45 min for 4 d). The rats in these three groups recovered within 4 d. The acupuncture group received EA therapy for 4 d, after HAc injection. The stomach was dissected to compare the pathological structures of ulcer. Also c-Fos activation in the nuclei of solitary tract (NTS) was observed under microscope after regular immunohistochemistry staining of brain stem sections. RESULTS: The number of ulcers was different among the four groups, especially between control group and paradistance-acupuncture group or pre-acupuncture group. In the latter group, the number of ulcers was much less. The gastric ulcer area was consistent with the histopathological results, indicating that pre-acupuncture had an obvious therapeutic effect on gastric ulcers. Acupuncture had a very modest effect and paradistance-acupuncture had no effect on gastric ulcers. No therapeutic effect was found in the control group. Fos-Li neurons in NTS induced by noxious gastric ulcer showed a significant difference between pre-acupuncture and control groups. CONCLUSION: Acupuncture before ulceration can obviously alleviate ulcer. The production of c-Fos proves that the vagus nerve mediates the induction of c-Fos in nuclei of solitary tract following experimental ulceration, suggesting that parasympathetic afferents promote the process of noxious visceral stimulation.

Acupuncture Therapy↗
PubMed2005

A diffusion model for drying of a heat sensitive solid under multiple heat input modes.

To obtain optimal drying kinetics as well as quality of the dried product in a batch dryer, the energy required may be supplied by combining different modes of heat transfer. In this work, using potato slice as a model heat sensitive drying object, experimental studies were conducted using a batch heat pump dryer designed to permit simultaneous application of conduction and radiation heat. Four heat input schemes were compared: pure convection, radiation-coupled convection, conduction-coupled convection and radiation-conduction-coupled convection. A two-dimensional drying model was developed assuming the drying rate to be controlled by liquid water diffusion. Both drying rates and temperatures within the slab during drying under all these four heat input schemes showed good accord with measurements. Radiation-coupled convection is the recommended heat transfer scheme from the viewpoint of high drying rate and low energy consumption.

Convection↗
PubMed2005

[Expression of Smad1 and Smad5 in the testis of infertile rats with kidney-yang deficiency].

OBJECTIVES: To study the expression of Smad1 and Smad5 in the testis of infertile rats with adenine-modeled kidney-yang deficiency and the pathological mechanism of infertility with kidney-yang deficiency, attempting to obtain experimental evidence for the prevention and treatment of male infertility. METHODS: Forty-eight 60 d male SD rats were divided randomly into 6 groups with 8 in each: 7 d, 14 d and 21 d kidney-yang deficiency groups, and 7 d, 14 d and 21 d control groups. The experimental rats had been fed with adenine (300 mg/kg) and the expression levels of Smad1 and Smad5 were measured with immunohistochemical SABC method at the 7th, 14th and 21st day. RESULTS: Smad1 immunoreactivity was mainly located in the spermatogonia, spermatocytes and spermatids, and the reactive substance distributed in cytoplasm with negative nuclei. Sertoli cells and Leydig cells were negative. Compared with the control, the expression level of Smad1 was decreased significantly at the 21st day (P < 0.05), but with no significant difference at the 7th and 14th day (P > 0.05). Smad5 immunoreactivity was mainly located in the spermatogonia and spermatocytes, and the reactive substance distributed in cytoplasm with negative nuclei. Compared with the control, the expression level of Smad5 was not significantly different at the 7th day (P > 0.05). The expression of Smad5 was negative at the 14th and the 21st day. CONCLUSION: The weaker expression of Smad1 and no expression of Smad5 may be one of the pathological mechanisms of infertility with adenine-modeled kidney-yang deficiency.

Animals↗
PubMed2005

[Chemical constituents from the seeds of Annona squamosa].

AIM: To study the antitumor active constituents of the seeds from Annona squamosa L. (Annonaceae). METHODS: Various chromatographic techniques were used to isolate and purify the constituents. Their physico-chemical properties and spectral data were determined to elucidate the structures. RESULTS: Eleven compounds were isolated and identified as annonaceous acetogenins: squamocenin (1), annotemoyin-2 (2), reticulatain-2 (3), squamocin-I (4), squamocin-B (5), squamocin (6), motrilin (7), squamostatin-D (8), squamostatin-E (9), cherimolin-1 (10), cherimolin-2 (11) from the ethyl alcohol extract of A. squamosa L. CONCLUSION: Squamocenin (1) is a new acetogenin. Annotemoyin-2 (2) and reticulatain-2 (3) were isolated from this plant for the first time.

Annona↗
PubMed2005

[Research on the technology of soaking under pressure and cutting process of Radix Curcumae].

OBJECTIVE: To determine the best processing technology parameters. METHOD: The changes of the weights, volatile constituents, total extract quantities by MeOH or CHCl3 and curcumenol contents of the roots of Curcuma wenyujin and C. kwangsiensis roots before and after water soaking were determined, so as to determine the quality control index for the process of preparing Yujin slices. The shortest soaking and moistening time and the appropriate drying temperature were studied. RESULT AND CONCLUSION: (1) The weight was decreased and the quantities of volatile constituents were changed during water soaking process. But the total extracts quantities and the curcumenol contents didn't change obviously. So the quality control index was decided as soaking as short as possible. (2) The soaking time could be decreased by using high pressure. The soaking time was related with the short diameter of the cross section of the root. (3) The soaking under pressure technology is that soaking on -0.095 MPa for 0.5 h, then on 0.14 MPa for 10-16 h, and moistening for 36-48 h, cutting drying in room temperature or less than 40 degrees C.

Curcuma↗
PubMed2005

Regular expression of discoidin domain receptor 2 in the improved adjuvant-induced animal model for rheumatoid arthritis.

OBJECTIVE: To investigate the expression of discoidin domain receptor 2 (DDR2) of fibroblast-like synovial cells in improved adjuvant-induced animal (AIA) model for rheumatoid arthritis (RA) and to provide evidence for DDR2's antagonist use clinically. METHODS: AIA was modified by administrating 0.1 mL of complete Freund's adjuvant (CFA, mixed with 5 mg Bacillus Calmette-Guerin vaccine/mL) into rats' right hind paws and 0.125 mL tumor necrosis factor-alpha (2 U/mL) into right ankles and subpatellar fatty tissue. The expression of DDR2 in fibroblast-like synovial cells was assessed using immunohistochemistry, immunofluorescence histochemistry, and in situ hybridization methods. Levels of anti-collagen II antibody were measured using enzyme-linked immunosorbent assay. RESULTS: Given the terms mentioned above, we found a more practical rat model, apparently decreasing immunization time (average 3-5 days). DDR2 can be detected upon the 15th day of immunization; expression gradually increased with time going on, and reaching a peak 35 days after immunization before gradually decreasing. Serum anti-collagen II antibody showed similar expression patterns as DDR2, but reached peak later than DDR2, about 40 days after immunization. CONCLUSION: Regular expression of DDR2 in animal models infers its important role in the pathological process of RA.

Animals↗
PubMed2004

Protective effect of rhIL-1beta on pancreatic islets of alloxan-induced diabetic rats.

AIM: To observe the protective effect of rhIL-1beta on pancreatic islets of alloxan-induced diabetic rats. METHODS: Protection of rhIL-1beta on pancreatic islets of alloxan-induced diabetic rats (n = 5) was demonstrated with methods of immunohistochemistry and stereology. The concentration of serum glucose was measured by GOD method and that of serum insulin by RIA. RESULTS: The concentration of serum glucose increased but that of insulin decreased after administration of alloxan(150 mg/kg), and the volume density and numerical density of the islets were zero. In rhIL-1beta pretreated rats, although the concentration of serum insulin decreased (from 11.9+/-3.0 mIU/L to 6.1+/-1.6 mIU/L, P<0.05), that of glucose was at normal level compared with the control group. As compared with alloxan group, the concentration of serum glucose in rhIL-1beta pretreated rats decreased (from 19.4+/-8.9 mmol/L to 12.0+/-4.0 mmol/L, P<0.05) and the volume density increased(0/L to. 1/L, P<0.05). CONCLUSION: rhIL-1beta pretreatment may have protective effect on the islets of alloxan-induced diabetic rats.

Animals↗
PubMed2004

Localization and variation of TRAIL and its receptors in human placenta during gestation.

The localization of TRAIL and its receptors in human placenta was studied under light microscopy using immunohistochemistry method. The variation of TRAIL and its receptors with development was also detected by in situ semi-quantification. The syncytiotrophoblast, cytotrophoblast, stromal cells and the capillary endothelium cells in human placenta all appeared to be TRAIL immunoreactive and the immunoreactive material was distributed on membrane and in cytoplasm with negative nuclei. During whole gestation there was no obvious variation of the staining of TRAIL. Although DR4, DR5, DcR1 and DcR2 can also be detected in the placenta throughout pregnancy, DR4 and DR5 staining increased with development whereas DcR1 and DcR2 staining decreased. Interestingly, at the beginning of the gestation DR4 and DR5 staining distributed on the cytotrophoblast mainly, whereas DcR1 and DcR2 mainly located in the syncytiotrophoblast cells. Collectively, these results suggest that human placenta may not only produce TRAIL but also be a TRAIL target organ, and that TRAIL/TRAILR system could take part in the self-homeostasis of placenta during whole gestation.

Animals↗
PubMed2004

Effects of serum from aplastic anemia patients on the expression of cyclin D3 isoform in umbilical cord blood CD34+ cells.

The pathogenesis of aplastic anemia (AA) was explored and the effects of AA serum on the expression of crucial cyclin D isoform (cyclin D3) in umbilical cord blood hematopoietic stem/progenitor cells were observed. The CD34+ cells were isolated from the cord blood with MIDI-MACS Semi-solid methylcellulose culture technique was used to measure the formation of CFU-GM; The expression level of cyclin D3 was assayed by semi-quantitative RT-PCR and Western-blot after the hematopoietic stem/progenitor cells were incubated in AA serum. The results showed that the AA serum could inhibit the formation of CFU-GM and down regulate the expression level of the cyclin D3 at the mRNA and protein level respectively. In conclusion, the AA serum could inhibit the proliferation of hematopoietic stem cells and down regulate level of cyclin D3, which might be one mechanism of hematopoiesis inhibition in AA.

Anemia, Aplastic↗
PubMed2004

Localization and in situ quantification of 5-hydroxytryptamine and its receptor in rat submaxillary gland.

5-Hydroxytryptamine (5-HT) and its receptor have been localized and quantified in the submaxillary gland of rats of various ages, using immunohistochemistry, in situ hybridization and in situ quantification. In male rats, the epithelial cells of serous acini, intercalated ducts, secretary tubes and excretory ducts all showed 5-HT and 5-HT receptor (5-HTR) immunoreactivity. Both 5-HT and 5-HTR reactive sites were found in the same cells of adjacent sections. 5-HT1A receptor mRNA hybridized signals could be detected in cytoplasm of these cells. The parasympathetic ganglia cells and endothelial cells of small vessels also showed 5-HT and 5-HTR immunoreactivity in the cytoplasm. However, in female rats, only the epithelial cells in excretory tubes showed 5-HT and 5-HTR immunoreactivity. The immunoreactivity was present in the same cells of adjacent sections. The relative content of 5-HT and its receptor increased during the first 60 postnatal days but remained constant from day 60 to day 90 postnatum. These results suggest that the submaxillary gland of rats possess autocrine 5-HT, which may regulate the function and development of the gland.

Aging↗
PubMed2004

[Effect of Ligustrazine on the expression of vascular endothelial growth factor in bone marrow stromal cells of radiation injured mice].

To evaluate the effect of Ligustrazine on the expression of VEGF in bone marrow stromal cells (BMSCs) of radiation injured mice and to explore the effect of VEGF on the recovery of hematopoiesis and the mechanism of signal transduction, the protein expression of VEGF, focal adhesion kinase (FAK) and mitogen-activated protein kinase (MAPK) in BMSCs were assayed by Western blot, the cell cycle and apoptosis rate of BMSCs were tested by flow cytometry. The effect of Ligustrazine on the hematopoiesis was evaluated at the same time. The results showed that the protein expression of VEGF in BMSCs was decreased significantly after irradiation and increased slowly with the time. The value in Ligustrazine-treated group almost reached normal level, but it remained lower than that in control group on day 14. The changes of phosphorylated FAK and MAPK protein expression had the same tendency. After (60)Co gamma-irradiation, the BMSCs were arrested in G0-G1 phase and apoptosis rate increased; these values recovered slowly with the time and remained higher than that in normal control group on day 14. The recovery of these values in Ligustrazine-treated group was sooner than that in irradiated control group, and they almost reached to the normal levels on day 14. It is concluded that irradiation could inhibit the expression of VEGF in BMSCs and induce apoptosis. The Ligustrazine promotes the recovery of bone marrow microenvironment probably by increasing the expression of phosphorylated FAK and MAPK in BMSCs.

Animals↗
PubMed2004

The effects of interferon-gamma on the expression of the cyclin D isoforms in cord blood hematopoietic stem/progenitor cells.

To explore the hematopoiesis inhibition mechanisms of interferon-gamma (IFN-gamma), the effects of IFN-gamma on the expression of the cyclin D in the umbilical cord blood hematopoietic stem/progenitor cells were observed. In the experiments the CD34(+) cells were isolated from the cord blood with MIDI-MACS system; semi-solid methylcellulose culture technique was used to measure the formation of CFU-GM; the expression levels of cyclin D isoforms were assayed by semi-quantitative RT-PCR, after the hematopoietic stem/progenitor cells were incubated with IFN-gamma. The results indicated that IFN-gamma could inhibit the formation of CFU-GM and down-regulate the expression of cyclin D2 and cyclin D3 at the mRNA level. It is concluded that the IFN-gamma could inhibit the proliferation of hematopoietic stem cells and down-regulate the expression of cyclin D, that may be one mechanism underlying the hematopoietic inhibition of IFN-gamma.

Cyclin D↗
PubMed2003

[Long-term effects of 17 beta-estradiol in promoting 45Ca uptake and mineralized bone-like tissue formation in human osteoblast-like cell lines TE85].

AIM: To study the long-term effects of 17 beta-estradiol (E2) on cell proliferation, 45Ca up-take, and mineralized bone-like tissue formation in human osteoblast-like cell line TE85. METHODS: Human osteoblast-like cell line TE85 was used as osteoblast cell model. Using methods of 3H-thymidine incorporation for cell proliferation and 45Ca deposit for calcium uptake, and Alizarin red S dye for mineralized bone-like tissue. RESULTS: Compared with the cells of control group, 3H-thymidine incorporation into TE85 cells was significantly increased (85.65%, 93.42% and 106.58%, respectively) and 45Ca uptake was increased (101.35%, 130.9% and 169.5% respectively), after treated with E2 (0.1, 1.0, 10 nmol.L-1) for 14 days. The stained area of Alizarin red S in E2 treated cells was also increased obviously. ICI182,780, a specific antagonist of estrogen receptor, was shown to partly inhibit E2 induced actions with the inhibition ratio of 19.6% or 37.28% in both experiments of 3H-TdR and 45Ca uptake on the condition of E2 (1.0 nmol.L-1). CONCLUSION: E2 was found to increase the mineralized bone-like tissue by enhancement of cell proliferation and promotion of calcium uptake, which were in favor of bone formation. These actions may be partly mediated by estrogen receptor.

Bone Density↗
PubMed2003

[Localization of the estrogen receptor alpha and beta-subtype in the nervous system, Hatschek's pit and gonads of amphioxus, Branchiostoma belcheri].

Immunocytochemical localization were investigated in the nervous system, wheel organ, Hatschek's pit and gonads of amphioxus using polyclonal antibodies against estrogen receptor-alpha and beta. The results revealed that ER-alpha and beta protein distributed in the above regions in larvae and adult at different developmental stages of both sexes. A major ER-alpha were expressed within nucleus of nerve cells, a few expressed in the cytoplasm and process as well as fiber of nerve cells in the forebrain, midbrain, hindbrain and nerve tube, while ER-beta were detected in the cytoplasm or on the cellular membrane, a few were within nucleus. ER-alpha immunopositive material distributed mainly in the nucleus of epithelial cells in the second layer of Hatschek's pit, a few were in the cytoplasm of upper layer epithelial cells, while ER-beta distributed in the nucleus of upper layer. In gonads, ER-alpha were distributed in the cytoplasm and nucleolus of oogonia and oocyte of small growth stage, germinal vesivle(nucleus) showed immunonegative reaction. In the large growth stage, strong immunopositive reaction were showed in nuclear membrane and nucleolus of oocyte, and within nucleus of mature egg cell in the mature stage. ER-beta immunopositive material distributed in the cytoplasm of oogonia and early oocytes as well as egg envelope of mature egg cell, the germinal vesicle showed immunonegative reaction. In testis, both ER subtype were localized in the cytoplasm of spermatogonia, primary and second spermatocyte as well as Sertoli cell, and within nucleus of spermatid cell, while spermatozoa showed immunonegative reaction. On the other hand, the results of double staining revealed that ER-alpha and beta numerously coexisted in a same cell, and fewly expressed in different cells in above regions. It is found for the first time that both estrogen receptor subtype, which mediated the regulate role of estrogen to neuroendocrine tissues in amphioxus, distributed extensively in amphiuoxus. The different localization of ER-alpha and beta receptor in the target cells suggests that the mediating estrogen signal line and the mechanism of gene transcription may be different.

Animals↗
PubMed2002

Effects of platelet factor 4 on expression of bone marrow heparan sulfate in syngenic bone marrow transplantation mice.

To explore the effects of platelet factor 4(PF4) on hematopoietic reconstitution and its mechanism in syngenic bone marrow transplantation (BMT). The syngenic BMT mice models were established. 20 and 26 h before irradiation, the mice were injected 20 micrograms/kg PF4 or PBS twice into abdominal cavity, then the donor bone marrow nuclear cells (BMNC) were transplanted. On the 7th day, spleen clone forming units (CFU-S) were counted. On the 7th, 14th and 21st day after BMT, the BMNC and megakaryoryocytes in bone marrow tissue were counted and the percentage of hematopoietic tissue and expression level of heparan sulfate in bone marrow tissue were assessed. In PF4-treated groups, the CFU-S counts on the 7th day were higher than those in BMT groups after BMT. The BMNC and megakaryoryocyte counts and the percentage of hematopoietic tissue and heparan sulfate expression level were higher than those in BMT group on the 7th, 14th and 21st day after BMT (P < 0.01 or P < 0.05). PF4 could accelerate hematopoietic reconstitution of syngenic bone marrow transplantation. The promotion of the heparan sulfate expression in bone marrow may be one of mechanisms of PF4.

Animals↗
PubMed2002

Effects of ligustrazine on hematopoiesis in the early phase of bone marrow transplantation mice.

To investigate the effects of Ligustrazine on histogenesis of bone marrow in the early phase of hematopoietic reconstruction in bone marrow transplantation (BMT) mice. The syngeneic BMT mice model was established. The syngeneic BMT mice were orally given 2 mg Ligustrazine twice a day. 1, 3, 5, 7, 10, 15 and 21 day(s) after BMT, peripheral blood granulocytes and bone marrow nucleated cells (BMNC) were counted and the diameter of central vein and the area of micro-vessel in femur were measured. The effect of Ligustrazine on hematopoietic stem cells was observed by colony forming unit of spleen (CFU-S). The effect of Ligustrazine on hemopoietic progenitors was studied by observing the number of progenitors of Granulocytes/Macrophage on day 10 and day 20 after BMT. In Ligustrazine-treated group, the diameter of center veins and the area of micro-vessel of femur were all significantly less than the control group 7, 10, 15, 21 days after BMT (P < 0.01). In addition, Ligustrazine significantly increased the number of CFU-S on day 10 and the number of CFU-GM on day 10, 20 after BMT. These results indicate that Ligustrazine can accelerate the histogenesis of hemopoietic bone marrow, which may be one mechanism by which Ligustrazine promotes hematopoietic reconstitution after BMT.

Animals↗