Effects of material interfaces on orientation and function of fibrinogen / 生物医学工程学杂志

Fibrinogen (Fg) in human plasma plays an important role in hemostasis, vascular repair and tissue integrity. The surface chemistry of extracellular matrix or biological materials affects the orientation and distribution of Fg, and changes the exposure of integrin binding sites, thereby affecting its adhesion function to platelets. Here, the quantity, morphology and side chain exposure of Fg adsorbed on hydrophilic, hydrophobic and avidin surfaces were measured by atomic force microscopy (AFM) and flow cytometry (FCM), then the rolling behavior of platelets on Fg was observed through a parallel plate flow chamber system. Our results show that the hydrophobic surface leads to a large amount of cross-linking and aggregation of Fg, while the hydrophilic surface reduces the adsorption and accumulation of Fg while causing the exposure and spreading of the α chain on Fg and further mediating the adhesion of platelets. Fg immobilized by avidin / biotin on hydrophilic surface can maintain the monomer state, avoid over exposure and stretching of α chain, and bind to the platelets activated by the A1 domain of von Willebrand factor instead of inactivated platelets. This study would be helpful for improving the blood compatibility of implant biomaterials and reasonable experimental design of coagulation

MCC1019, a selective inhibitor of the Polo-box domain of Polo-like kinase 1 as novel, potent anticancer candidate

Polo-like kinase (PLK1) has been identified as a potential target for cancer treatment. Although a number of small molecules have been investigated as PLK1 inhibitors, many of which showed limited selectivity. PLK1 harbors a regulatory domain, the Polo box domain (PBD), which has a key regulatory function for kinase activity and substrate recognition. We report on 3-bromomethyl-benzofuran-2-carboxylic acid ethyl ester (designated: MCC1019) as selective PLK1 inhibitor targeting PLK1 PBD. Cytotoxicity and fluorescence polarization-based screening were applied to a library of 1162 drug-like compounds to identify potential inhibitors of PLK1 PBD. The activity of compound MC1019 against the PLK1 PBD was confirmed using fluorescence polarization and microscale thermophoresis. This compound exerted specificity towards PLK1 over PLK2 and PLK3. MCC1019 showed cytotoxic activity in a panel of different cancer cell lines. Mechanistic investigations in A549 lung adenocarcinoma cells revealed that MCC1019 induced cell growth inhibition through inactivation of AKT signaling pathway, it also induced prolonged mitotic arrest-a phenomenon known as mitotic catastrophe, which is followed by immediate cell death apoptosis and necroptosis. MCC1019 significantly inhibited tumor growth in a murine lung cancer model without affecting body weight or vital organ size, and reduced the growth of metastatic lesions in the lung. We propose MCC1019 as promising anti-cancer drug candidate.

On the possible involvement of bovine serum albumin precursor in lipofection pathway.

Protein factors involved in lipofection pathways remain elusive. Using avidin-biotin affinity chromatography and mass finger printing analysis technique, herein we report the identification of a 70 kDa size protein (bovine serum albumin precursor, BSAP) which binds strongly with lipoplexes and may play role in lipofection pathway. Using multiple cultured animal cells and three structurally different cationic transfection lipids, we show that the efficiencies of liposomal transfection vectors get significantly enhanced (by ~2.5- to 5.0-fold) in cells pre-transfected with lipoplexes of reporter plasmid construct encoding BSAP. Findings in the cellular uptake experiments in A549 cells cultured in DMEM supplemented with 10% (w/w) BODIPY-labelled BSAP are consistent with the supposition that BSAP enters cell cytoplasm from the cell culture medium (DMEM supplemented with 10% FBS) used in lipofection. Cellular uptake studies by confocal microscopy using BODIPY-labelled BSAP and FITC-labelled plasmid DNA revealed co-localization of plasmid DNA and BSAP within the cell cytoplasm and nucleus. In summary, the present findings hint at the possible involvement of BSAP in lipofection pathway.

Distribution of Neuropeptides in Nasal Polyp and Polypoid Mucosa / 대한이비인후과학회지

BACKGROUND: The pathogenesis of nasal polyp is not well understood, however the common pathway of nasal polyp formation is tissue edema. Factors that are known to predispose tissue edema include histamine, arachidonic acid metabolites, serotonin and peptidergic neuro-transmitters. OBJECTIVES: To elucidate the pathophysiological roles of peptidergic neurotransmitters on the polyp formation, we investigated the distribution of several immunoreactive nerve fibers. MATERIALS AND METHODS: We obtained normal middle turbinate mucosa, edematous middle turbinate mucosa, polypoid middle turbinate mucosa and nasal polyp tissue from 5 patients at the time of surgery and we determined the distribution of substance P(SP) immunoreactive, vasoactive intestinal peptide(VIP) immunoreactive and neuropeptide-Y(NPY) immunoreactive nerve fibers in the above tissues using avidin-biotin complex(ABC) immunohistochemical method. RESULTS: Fine varicose peptidergic nerve fibers were found numerously in normal mucosa and they were decreased in number in the edematous mucosa. However the peptidergic nerve fibers were hardly found in the polypoid mucosa and the pedicle of polyp, and no nerve fibers were found in the apex of polyp except VIP-immunoreactive nerve fibers. CONCLUSION: Decreasing tendency of distribution of these peptidergic nerve fibers in the order of edematous mucosa, polypoid mucosa, and polyp may indicate the denervation of autonomic nervous system. These phenomenon suggests the important role of peptidergic neurotransmitters in the early stage of polyp formation. However, once the polyp has been formed, contribution of the peptidergic neurotransmitters is considered to be negligible.

In vitro immunohistochemical localization of S-phase cells by a monoclonal antibody to bromodeoxyuridine

Bromodeoxyuridine, an analogue of thymidine, can be detected by means of monoclonal antibodies and utilized as a marker of the S-phase of the cell cycle. In vitro immunohistochemical application of the BrdU/anti-BrdU-MAb method permits a quantitative assessment of the proliferative activity of a tissue as well as the direct location of the actively replicating cells in histological sections. In this paper, a method for the detection of the labeling index of S-phase cells in normal and neoplastic tissues with in vitro BrdU labeling and standard immunohistochemical techniques using anti-BrdU-MAb and avidin-biotin peroxidase complex is described. We have employed this method in 47 human solid tumor samples, including squamous cell carcinomas of head and neck and cervix uteri, adenocarcinomas and malignant lymphomas, and also evaluated the possible application of the BrdU labeling index to estimate the cycling S-phase cells in neoplastic cell populations. In our data, the in vitro labeling index varied greatly in an individual case (3.56-29.2%) and from an area to an area within the same case. Squamous cell carcinomas of the head and neck showed higher LI than those of the cervix uteri. A case of metastatic carcinoma to the lung from ductal carcinoma of the breast had the highest LI (29.2%), in contrast to the low LI (3.6%) in the primary ductal carcinoma of breast.

Detection of Treponema pallidum in Tissues by the Avidin - Biotin - Peroxidase Complex Techniques / 대한피부과학회지

Using the avidin-biotin-peroxidase complex(ABC) technique, 36 skin specimens from 30 patients with primary and secondary syphilis and a gastric mucosal specimen from a patient with secondary syphilis which were confirmed by clinical history, physical examination, the VDRL, FTA-ABS, TPHA, and 19s(IgM)-FTA test, were examined. The results were compared with that of the indirect mmunoperoxidase technique which was done by authors previously with same specimens. The following results were obtained. 1. Of the 37 specimens, 35(95%) were positive in ABC technique and 33 of the 37 specirnens(89%) were positive in the indirect immunoperoxidase technique. 2. The ratio of agreement of the results between the ABC and the indirect immunoperoxidase technique was 89%. 3. Most of the treponemes were located in the upper dermis, epidermis, and blood vessel walls in the arder named, and rarely in the lower dermis of the syphilitic skin lesions. There was no remarkable difference in histologic distribution of treponemes between the clinical stages and types of syphilitic skin lesions. :From the results, the ABC technique is considered to be an excellent method for detecting the treponemes in the suspected syphilitic lesions.

Solid-phase enzyme. linked immunosorbent assay and its clinical significance for human neutrophil elastase / 中国病理生理杂志

The role of neutrophil in the pathogenesis of many diseases attracts more attentions than before. Neutrophil elastase (NE), a powerful neutrol proteinase capable of causing major tissue destruction in many diseases, is mainly present in the azurophil granules of neutrophil. A solid-phase enzyme-linked immunosorbent-biotin assay for human NE has been developed. Only 20?l of plasma sample is needed. Non-smoking healthy adults have 33.7?6.7ng NE/ml plasma; patients with chronic obstructive pulmonary diseases, 48.0+ 10.9 ng NE/ml; patients with pyogenic dermatisis, 69.1?15.7 ng NE/ml; patients with systemic lupus erythematosus, 61.0?13.9 ng NE/ml; patients with aplastic anemia, only 12.3?5.3 ng NE/ml. All of these results have significant differences compared with the result of healthy adults. The results of assay showed that this quantitative assay with good specificity and accuracy may be a better criterion for investigating the effect of NE on pathogenesis of some diseases.

STUDY OF SERUM TRAb IN AUTOIMMUNE THYROID DISEASE WITH ABC- ELISA / 西安交通大学学报(医学版)

In this paper the investigation of using a new method-ABC-ELISA in assay of Autoimmune Thyroid Disease are presented. The sensitivity of ABC-ELISA is compared with that of standard ELISA; Its reliability is proven by the methods of detecting TSAb with FRTL-5. TRAb is detected by ABC-ELISA in 91% of untreated Graves'. TRAb is detected by Standard ELISA in 70% of untreated Graves'. The results of ABC-ELISA in 26 untreated Graves' are equal to that of the method of detecting TSAb with FRTL-5. Therefore, we consider that ABC-ELISA is a sensitive, reproducible, convenient method applicable to clinical practice.

USE OF ABC METHOD IN THE STUDY OF LECTIN RECEPTORS IN LIVER TUMORS / 第二军医大学学报

The high affinity interaction of avidin-biotin in immunoenzyrnatic techniques has provided a simple and sensitive method to localize antigens in formalin-fixed and paraffin-embedded tissues.The distribution of lectin receptors in primary hepatocellular carcinoma, int-ahepatic cholangiccarcinorria an.i cavernous hemangi-oma was studied for the first time by avidin-biotin-peroxidase complex (ABC) method.The results show that the method was simple, highly sensitive, and had gcod reproducibility and specificity as well as higher value of practical use.