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Biomedical subjects

Yi Lin

Publications and source records attributed to Yi Lin.

At least 37 records · Page 2Linked to original sources
PubMed2005

Study of fibrinogen adsorption on self-assembled monolayers on Au(111) by atomic force microscopy.

The adsorption of plasma protein fibrinogen on the self-assembled monolayers (SAMs) of n-hexadecyl mercaptan and citrate was investigated with atomic force microscopy (AFM). On the basis of the preparation of these two flat SAMs on Au(111), high-resolution AFM images of bovine fibrinogen were obtained with different protein concentrations. The results indicated that the surface chemical composition significantly affected the adsorption behavior of fibrinogen. Since fibrinogen plays a key role in the regulation of both haemostasis and thrombosis, high-resolution AFM imaging on SAMs is expected to be an effective approach to study the haemocompatibility of materials with different surface chemistry.

Adsorption↗
PubMed2005

Solubilization of boron nitride nanotubes.

A successful attempt in the functionalization and solubilization of boron nitride nanotubes is reported, and a functionalization mechanism based on interactions of amino functional groups with nanotube surface borons is proposed.

Journal Article↗
PubMed2005

NMR detection of single-walled carbon nanotubes in solution.

The detection of nanotube carbons in solution by (13)C NMR is reported. The highly soluble sample was from the functionalization of (13)C-enriched single-walled carbon nanotubes (SWNTs) with diamine-terminated oligomeric poly(ethylene glycol) (PEG(1500N)). The ferromagnetic impurities due to the residual metal catalysts were removed from the sample via repeated magnetic separation. The nanotube carbon signals are broad but partially resolved into two overlapping peaks, which are tentatively assigned to nanotube carbons on semiconducting (upfield) and metallic (downfield) SWNTs. The solid-state NMR signals of the same sample are similarly resolved. Mechanistic and practical implications of the results are discussed.

Journal Article↗
PubMed2005

Visualizing adhesion-induced agglutination of Escherichia coli with mannosylated nanoparticles.

Polymeric nanoparticles covalently functionalized with derivatized D-mannose molecules were synthesized and characterized. These nanoparticles have an average size of approximately 160 nm in diameter, thus bearing a large number of surface-tethered mannose moieties for multivalent interactions with adhesins on bacterial cells. Specifically, the mannosylated nanoparticles bind strongly with Escherichia coli, allowing the convenient visualization of adhesion interactions under a conventional electron microscope. Since a single nanoparticle is capable of binding more than one cell, the adhesion interactions result in significant nanoparticle-mediated cell agglutination according to electron microscopy imaging. Potential applications of the mannosylated nanoparticles in the inhibition of enteropathogenic infections are discussed.

Adhesins, Escherichia coli↗
PubMed2005

Poly(ethylene-co-vinyl alcohol) functionalized single-walled carbon nanotubes and related nanocomposites.

Single-walled carbon nanotubes (SWNTs) were functionalized by poly(ethylene-co-vinyl alcohol) (EVOH) copolymer under carbodiimide-activated esterification reaction conditions. Similar to the parent EVOH copolymer, the EVOH-functionalized carbon nanotubes are soluble in highly polar solvent systems such as DMSO and hot ethanol-water mixtures. The soluble EVOH-SWNT sample was characterized by various techniques, including optical absorption, Raman, NMR, electron microscopy, and thermogravimetric analysis. The common solubility of EVOH and EVOH-SWNT allowed their intimate mixing in solution, and thus the fabrication of nanocomposites in which the SWNTs are homogeneously dispersed in the polymer matrix.

Ethanol↗
PubMed2005

Murine CD200+ CK7+ trophoblasts in a poly (I:C)-induced embryo resorption model.

Cytokeratin 7 (CK7) is currently regarded as the best marker for trophoblast cells, while CD200 (OX-2), known as 'tolerance signal', plays an important role in normal pregnancy. In this study, the status of CD200 expression was investigated in BALB/c x C57BL/6 and BALB/c x BALB/c mating combinations designed as allogeneic and syngeneic murine models of induced embryo resorption, in which the resorption rate was boosted by an i.p. injection of poly (I:C), a synthetic double-stranded RNA. The percentage of CD200+ cells in the CK7+ cell population (CD200+ CK7+ percentage) and the absolute number of these cells were determined with flow cytometry, using trophoblast cells collected at day 8.5 and day 13.5 of gestation. The potential effect of poly (I:C) on CD200 expression was also evaluated by detecting the CD200+ CK7+ percentage in trophoblast cells incubated in the presence or absence of poly (I:C), in vitro. The distribution pattern of CD200+ cells at the feto-maternal interface was evaluated by immunocytochemical examination. When 10(4) cells were analyzed at day 8.5 of gestation in each case, no significant difference was observed between the poly (I:C)-treated group and the control PBS group either in the CD200+ CK7+ percentage or in the absolute number of these cells. Similar results were observed both in BALB/c x C57BL/6 mice and in BALB/c x BALB/c mice. However, the CD200+ CK7+ percentage was significantly decreased in the poly (I:C)-treated group when evaluated at day 13.5 of gestation. Accordingly, a dramatically elevated rate of embryo resorption was observed at this time point of pregnancy after the administration of poly (I:C). In addition, the CD200+ CK7+ percentage was significantly lower in trophoblast cells incubated with poly (I:C) at a certain concentration, in vitro, while histocytochemical examination showed the CD200+ cells mainly scattered in placental tissue adjacent to the interface of the placenta and uterus. This indicates that sufficient expression of the CD200 molecule on CK7+ cells at the feto-maternal interface may be necessary for the maintenance of embryos during pregnancy in this rodent model, while poly (I:C) administration may increase embryo resorption, at least partially via direct inhibition of CD200 expression on CK7+ cells.

Abortion, Spontaneous↗
PubMed2005

[Discussion of some problems about use of traditional Chinese medicine in perioperative management of breast cancer].

The study on use of traditional Chinese medicine in perioperative management of breast cancer is still in the beginning phase. With the emergence of new understanding about the biological characteristics of breast cancer, the concept of treatment has changed. For instance, the resection extent is tending to be narrower, large doses of radiotherapy may be adopted during the operation, and early use of adjuvant chemotherapy is advocated after the operation. These have bought about changes to the intervention factors in the perioperative period for breast cancer. Some related problems about the participation of traditional Chinese medicine in perioperative management of breast cancer are discussed in this article, so as to make the perioperative management perfect.

Breast Neoplasms↗
PubMed2005

[Effects of Runing Recipe II on expressions of p53 and ras oncogene proteins and cell cycle of the transplanted Ca761 breast cancer in mice].

OBJECTIVE: To explore the mechanisms of Runing Recipe II (a recipe composed of traditional Chinese herbs) in inhibiting the growth of breast cancer by observing its effects on the expressions of p53 and ras oncogene proteins and cell cycle of the transplanted Ca761 breast cancer in mice. METHODS: We established the breast cancer model by transplanting Ca761 cells in mice. The mice were randomly divided into 4 groups: normal saline control group, CTX-treated group, Runing Recipe II-treated group, and Runing Recipe II and CTX-treated group, with 12 mice in each group. We detected the cell cycle of the cancer cells in the mice's transplanted tumor with flow cytometry and measured the expressions of p53 and ras oncogene proteins in the transplanted tumor with immunohistochemical methods. RESULTS: The percentages of tumor cells in S-phase of the Runing Recipe II treated group, CTX-treated group and Runing Recipe II and CTX-treated group were significantly lower than that of the normal saline control group respectively (P<0.05). The percentage of tumor cells in G(0)-G(1) phase of the Runing Recipe II treated group was lower than that of the CTX-treated group (P<0.05), while the percentage of tumor cells in G(2)-M phase was higher than that of the CTX-treated group. The immunoreactive scores (IRSs) of p53 in the Runing Recipe II treated group and Runing Recipe II and CTX-treated group were significantly lower than that in the normal saline control group respectively (P<0.05). The effect of CTX on the expression of p53 was not significant. The IRSs of ras oncogene protein in the Recipe II-treated group, CTX-treated group and Runing Recipe II and CTX-treated group were lower than that in the normal saline control group respectively (P<0.05). CONCLUSION: Runing Recipe II can inhibit the growth of Ca761 breast cancer in mice by controlling the cell cycle of the transplanted tumor. This may be related to its effect on the gene expressions of p53 and ras in the tumor tissue.

Animals↗
PubMed2005

[Studies on the growth, chemical components and physiological characteristics of F1 generation of Dendrobium huoshanense].

OBJECTIVE: Through a comparison between F1 and its' parents on the growth, chemical components and physiology, this study aims to find the possibility of selecting new dendrobium hybrids with high yield and good quality. METHOD: To determinate the growth, chemical components, photosynthesis, hormones and isoenzyme in the plants. RESULT: Photosynthetic area, content of chlorophyll, net photosynthesis and yield of F1 generation are higher than those of the parents; chla/b rate is lower; growth is almost the same as in Dendrobium moniliforme; content of chemical components are the same as in D. huoshanense. F1 is approaching of advantages of parents. CONCLUSION: Physiological characters, yield and quality of F1 are greatly improved by hybridization.

Alkaloids↗
PubMed2005

[Study on LUO Zhao-ju's academic thought in the new Chinese Acup-Mox Surgical Therapeutics].

OBJECTIVE: To probe preliminarily academic thought of New Chinese Acup-Mox Surgical Therapeutics written by LUO Zhao-ju. METHODS: Read, analyze and study New Chinese Acup-Mox Surgical Therapeutics written by LUO Zhao-ju, and sum up the academic thought. CONCLUSION: The main academic thought and values of the book embody in the seven aspects: Spreading and popularizing acupuncture and moxibustion medicine; developing surgery of acupuncture and moxibustion; elucidating cause of disease and pathogenesis; advocating treatment in accordance with different symptoms and signs; paying great attention to the furuncle; highly praising the simple and practical prescriptions; initiating acupuncture combined with medication of Chinese drugs.

Acupuncture↗
PubMed2005

[Following the fate of murine epidermal stem cells in a syngeneic dermal equivalent in vivo].

OBJECTIVE: To follow the fate of murine epidermal stem cells (ESCs) seeded in a syngeneic dermal equivalent implanted in vivo. METHODS: Embryonic stem (ES) cells were induced in vitro to differentiate into ESCs. After stained with a fluorescent dye Hoechst 33342, these ESCs were seeded into a fibroblast-collagen-gelatin sponge complex, functioning as a dermal equivalent model, and implanted subcutaneously into 129/J mice, which were syngeneic to these stem cells. The fate of these cells was observed with HE staining, immunocytochemical staining or Van Gieson's staining. RESULTS: These ESCs were clearly visible in the implant by fluorescent microscopy 3 weeks or longer after implantation. These cells remained viable, differentiated into hair follicle-like structure, glandular structure, and gave rise to additional structures displaying features resembling native dermis. A number of markers were expressed in the differentiated structures, including CD29 (integrin beta1 subunit) and cytokeratin 18 (CK18). No apparent rejection or severe side effects were observed at least during the 10 weeks following implantation. CONCLUSION: Now that ESCs could survive in vivo in this dermal equivalent model, and differentiate into hair follicle-like structures as well as glandular structures, it is feasible to use these cells as seed cells in the study to fabricate dermal equivalent having the potential to develop dermal appendages.

Animals↗
PubMed2004

Diminished band-gap transitions of single-walled carbon nanotubes in complexation with aromatic molecules.

The near-IR absorption spectrum of semiconducting single-walled carbon nanotubes is characterized by the transitions associated with the first (S11) and second (S22) pairs of van Hove singularities in the electronic density of states. We report that a significant effect on the transitions can be caused by non-covalent complexation of the nanotube with planar aromatic molecules such as pyrenes in solution, resulting in the absence of S11 and S22 bands in the near-IR absorption spectrum. Since the complexation is reversible, the characteristic absorption bands can be turned on and off with the complexation in a reversible fashion.

Journal Article↗
PubMed2004

Selective interactions of porphyrins with semiconducting single-walled carbon nanotubes.

A derivatized porphyrin with long alkyl chains, 5,10,15,20-tetrakis(hexadecyloxyphenyl)-21H,23H-porphine, is selective toward semiconducting single-walled carbon nanotubes (SWNTs) in presumably noncovalent interactions, resulting in significantly enriched semiconducting SWNTs in the solubilized sample and predominantly metallic SWNTs in the residual solid sample according to Raman, near-IR absorption, and bulk conductivity characterizations.

Journal Article↗
PubMed2004

Nitric oxide attenuates insulin- or IGF-I-stimulated aortic smooth muscle cell motility by decreasing H2O2 levels: essential role of cGMP.

Insulin and insulin-like growth factor I (IGF-I) both play important roles in vascular remodeling. Moreover, nitric oxide (NO) is well established as a counterregulatory agent that opposes the actions of several vascular agonists, in part by decreasing smooth muscle motility. We tested the hypothesis that NO blocks insulin or IGF-I-induced rat aortic smooth muscle cell motility via a mechanism involving the attenuation of agonist-induced elevation of hydrogen peroxide levels and cGMP as mediator. Insulin or IGF-I induced an increase of hydrogen peroxide levels and cell motility. Both effects were blocked by catalase or diphenyleneiodonium, indicating that hydrogen peroxide elevation is necessary for induction of cell motility. Two NO donors mimicked the effects of catalase, indicating that NO decreases cell motility by suppressing agonist-induced elevation of hydrogen peroxide. A cGMP analogue mimicked the effect of NO, whereas a guanyl cyclase inhibitor blocked the effect of NO on hydrogen peroxide levels, indicating that elevation of cGMP is both necessary and sufficient to account for the reduction of hydrogen peroxide levels. A NO donor as well as a cGMP analogue attenuated insulin-stimulated NADPH activity, indicating that NO decreases hydrogen peroxide levels by inhibiting the generation of superoxide, via a cGMP-mediated mechanism. Finally, exogenous hydrogen peroxide increased cell motility and reversed the inhibitory effect of cGMP. These results support the view that NO plays an antioxidant role via reduction of hydrogen peroxide in cultured rat aortic smooth muscle cells and that this effect is both necessary and sufficient to account for its capacity to decrease cell motility.

Animals↗