Effects of cepharanthin on neutrophil chemotaxis, phagocytosis, and reactive oxygen species generation.

The effects of cepharanthin on inflammatory parameters such as neutrophil chemotaxis, phagocytosis and reactive oxygen species (ROS) generation, were examined. Cepharanthin significantly decreased the levels of O2-, H2O2, and OH. generated by neutrophils. H2O2 and OH. generated in a cell-free, xanthine-xanthine oxidase system were also reduced in the presence of cepharanthin. However, the drug did not affect neutrophil chemotaxis or phagocytosis. The present study indicates that cepharanthin is an effective ROS scavenger, exerting its anti-inflammatory action by reducing the potent ROS species excessively generated in tissues and organs, especially at the sites of inflammation.     

五味子酚对大鼠嗜中性白细胞功能与形态的作用(英文)

目的:探讨五味子酚(Sal)对大鼠嗜中性白细胞(Neu)功能的调节作用.结果:Sal 1,10,100μmol·L~(-1)剂量依赖性抑制Neu功能,Sal 100μmol·L~(-1)使Neu表面伪足和皱褶消失,并可降低细胞内钙离子浓度、升高细胞内cAMP水平.结论:Sal可通过影响细胞内钙离子浓度、cAMP水平及细胞表面形态抑制Neu的功能.     

Effects of obstructive jaundice on neutrophil production and acquisition of chemotactic activity in the bone marrow

Background and Aims:  Increased numbers and enhanced functions of peripheral neutrophils have been observed in obstructive jaundice. However, the effects of obstructive jaundice on the bone marrow, that is neutrophil production and acquisition of neutrophil chemotactic activity, have been poorly understood. In the present study, differentials of bone marrow cells and chemotactic activity of bone marrow neutrophils were evaluated in bile duct-obstructed rats.
Methods:  Male Wistar rats underwent either bile duct obstruction for 10 days or bile duct obstruction for 4 days followed by 6 days' internal biliary drainage. Differentials of peripheral blood and bone marrow cells were sequentially determined. Chemotactic activity of peripheral and bone marrow neutrophils was evaluated with a modified Boyden method using interleukin-8 (recombinant rat Gro-β) as a chemoattractant.
Results:  Numbers of peripheral neutrophils significantly increased after bile duct obstruction. Significant increases in the myeloid/erythroid (M/E) ratio of bone marrow cells were observed after bile duct obstruction. The neutrophil proliferative pool (promyelocytes and myelocytes) increased initially, followed by an increased neutrophil storage pool (metamyelocytes, bands, and segmented neutrophils). The M/E ratio as well as the neutrophil proliferative and storage pools normalized after internal biliary drainage. Chemotactic activity was enhanced in both peripheral and bone marrow neutrophils after bile duct obstruction, and enhanced chemotaxis was alleviated with internal biliary drainage.
Conclusion:  The present results strongly suggest the principal role of the bone marrow in increasing the number of neutrophils and their chemotactic activity during obstructive jaundice.     

Identification of neutrophil chemotactie factors in bronchoalveolar lavage fluid of asthmatic patients

Background Although neutrophils have been implicated in bronchial asthma, the mechanism(s) which bring these cells into the airways is poorly understood. Objective To investigate the presence and identity of neutrophil chemotactic factors in bronchoalveolar lavage (BAL) fluid from atopic asthmatic subjects. Method BAL fluid was obtained from 13 subjects (seven asthmatics and six normals). aged 19 to 60 yr, at bronchoscopy. Separation of neutrophil chemotactic activity (NCA) was achieved by FPLC cation exchange chromatography. Fractions were collected and assayed for chemotaxis multiwell micro-chemotaxes chambers using polycarbonate filters, for the complement peptide C5a/C5a des Arg by radioimmunoassay (RIA) and for interleukin-8 (IL-8) by ELISA. Results NCA was found in FPLC fractions of BAL samples in four out of seven asthmatics and each of these subjects had at least three similar peaks of NCA. The major peak of NCA was found to contain immunoreactive C5a/C5a des Arg and chemotaxis. In response to this NCA could be blocked by desensitization of the neutrophils with recombinant C5a. Purified serum derived C5a/C5a des Arg was found to have altered chromatographic properties when added to BAL fluid; this suggested that BAL fluid contained proteins which interacted with the C5a/C5a des Arg. Immunoreactive IL-8 (iIL-8) was also detected but its concentration or chemical form was insufficient to induce neutropbil chemotaxis. Conclusion This study demonstrates that bronchial asthmatic lavage fluid contains C5a/C5a des/Arg and iL-8, together with other as yet unidentified factors which may contribute to neutropbil recruitment in this disease.     

Strategy and timing of peripheral nerve surgery

The authors review the latest theories of peripheral nerve regeneration and repair. They present their research on nerve regeneration including the alterations in the mother cell body, and in the distal part of the axon, and the time required to reach the best production of amino acids for cytoskeleton reconstruction. Other research of particular interest which is presented regards the chemotactic arrangement of motor and sensory axons inside a vein. This research has shown that the axons are able to find their way to the appropriate (sensory or motor) distal endoneural tubes.Adoption phenomena are also presented.The discussion of surgery includes the type (suture, glueing, grafts, tubulization) and the time of surgical repair. Timing and repair strategies are related to the site of the lesion (which can require that a greater or smaller amount of cytoskeleton be reconstructed), the type of the injury, the state of surrounding tissues, the age of the patients, injuries to muscles, tendons, bones, vessels and skin. A scheme of strategy is proposed.     

A new assay for leukocyte chemotaxis using cell retrieval,electronic particle counting and flow cytometry

A new micropore membrane assay for leukocyte migration has been devised. It permits the complete retrieval in monodisperse suspension of functionally intact cells that have traversed the membrane, thus allowing the application of precise, automated techniques, including flow cytometry and electronic particle counting. Hemocytometers may also be used. Direct comparison with 2 different conventional membrane methods showed that the new method performed superiorly. It was also much more economical with regard to time and labor. This technique permitted detection of functional differences between leukocytes isolated from blood in different ways. Data on the duration of concentration gradients in chemotaxis chambers are also presented.     

Human sperm chemotaxis: both the oocyte and its surrounding cumulus cells secrete sperm chemoattractants

BACKGROUND: Human sperm chemotaxis to pre-ovulatory follicular fluid is well established in vitro. However, it is not known whether the female's oocyte-cumulus complex secretes sperm chemoattractants subsequent to ovulation (for enabling sperm chemotaxis within the Fallopian tube) and, if so, which of these cell types--the oocyte or the cumulus oophorus--is the physiological origin of the secreted chemoattractant. METHODS: By employing a directionality-based chemotaxis assay, we examined whether media conditioned with either individual, mature (metaphase II) human oocytes or the surrounding cumulus cells attract human sperm by chemotaxis. RESULTS: We observed sperm chemotaxis to each of these media, suggesting that both the oocyte and the cumulus cells secrete sperm chemoattractants. CONCLUSIONS: These observations suggest that sperm chemoattractants are secreted not only prior to ovulation within the follicle, as earlier studies have demonstrated, but also after oocyte maturation outside the follicle, and that there are two chemoattractant origins: the mature oocyte and the surrounding cumulus cells.     

Platelet-derived growth factor (PDGF) BB acts as achemoattractant for human malignant mesotheliomacells via PDGF receptor b - integrin a3b1 interaction

Platelet-derived growth factor BB (PDGF BB) and the PDGF receptor b are expressed on mesotheliomacells, but their biological function has not yet been defined. In the present study we used Boyden chambersfitted with filters coated with the adhesive matrix proteins fibronectin, laminin, collagen type IV or the non-matrixadhesive molecule poly-L-lysine (PLL). Mesothelioma cells migrated towards PDGF BB at concen-trationsranging from 0.78 to 12.5 ng/ml if matrix proteins were present as adhesive substrates. This migrationwas integrin dependent since the same cells failed to migrate if the adhesive interactions necessary for migra-tionwere provided by molecules other than integrins. Migration of mesothelioma cells on fibronectin, lamininor collagen-type IV in response to PDGF BB was inhibited if the cells were pretreated with blocking anti-bodiesto a3b1 integrin. These findings describe for the first time PDGF BB as a chemoattractant for malig-nantmesothelioma cells and that collaboration between PDGF receptor b and integrin a3b1 is necessaryfor the motile response of these cells to PDGF BB.©Kluwer Academic Publishers     

Bedeutung der Fibroblasten-Chemotaxis für Wundheilung und Tumorzellevasion

Summary Fibroblast are responsable for the synthesis of the structural proteins of the connective tissue. A further property of these cells, their migratory ability, could be analyzed in the last years. A special form of migration is chemotaxis, which can be quantitatively measured in a modified Boyden chamber in-vitro. Using this method chemoattractive substances could be characterized, which are able to stimulate fibroblasts and tumorcells to chemotactic migration. Furthermore it could be proved, that benign and transformed cell lines react in a different manner towards these chemoattractive substances. The in-vitro results allow some hypotheses about both fibroblast migration in wound healing or chronic inflammation, and the mechanisms of tumor cell evasion in the tumor surrounding tissue or the metastasizing process in other organs.

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Abkürzungen PDGF platelet derived growth factor - LTB₄ Leukotrien B 4 Mit Unterstützung der Deutschen Forschungsgemeinschaft Me 766/1–3