This study aims at providing a new technique for the isolation and culture of goldfish microglial cells. So far no protocol has been designed for the growth of these cells in vitro, despite the growing interest in the remarkable capacity of goldfish central nervous system (CNS) for regenerating severed axons. This newly developed technique has little or no similarity to those used in the isolation of mammalian microglia, and is distinguished by its simple setup and its fast yield for microglial cells. In addition, a virtually pure population of microglia was generated when plated on untreated plastic dishes, eliminating further need for purification. This technique may thus provide a starting point for future characterization of the microglial cells in vitro, which may eventually help toward building a better understanding of the function and biology of these cells. A preliminary morphological characterization of the cells has also been conducted, in addition to groundwork experiments on the phagocytic activity of these cells in vitro, using myelin to stimulate phagocytosis. These assays were oriented toward providing a comparison to the mammalian cultures of microglia, and so far, displayed several similarities in morphologies and phagocytosis.

Bibliography: leaves 213-223. / xv, 223 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis examines the cell-fluid interactions that occur during homogenization and combines them with an investigation of the mechanical properties of the cell. This results in a predictive model for cell-disruption efficiency during high-pressure homogenization. The mechanical properties of individual cells are characterised using a micro-manipulation technique. / Thesis (Ph.D.)--University of Adelaide, Dept. of Chemical Engineering, 1997

Compounds from the marine environment exhibit a wide variety of biological activities, and thus hold much promise as potential drugs. The halichondrins, isolated from the Kaikoura sponge Lissodendoryx sp. are no exception to this, demonstrating potent anticancer activity. Novel cytotoxic compounds have also been isolated from the Chatham Rise sponge Lamellomorpha strongylata. Knowledge of the cellular origins of such compounds is desirable, in order to establish if the sponge or associated micro-organisms are producing the compounds of interest. Siderophores are also important molecules, which are produced on demand by bacteria in order to obtain sufficient iron necessary for their growth. Knowledge of the biosynthesis of these compounds has potential for the control of undesirable bacteria, such as the anthrax-causing pathogen Bacillus anthracis. Cell separation studies have been carried out on Lamellomorpha strongylata, locating a swinholide in sponge-associated filamentous bacteria and theonellapeptolides in sponge-associated unicellular bacteria. A microscopic analysis of dissociated cells from Lissodendoryx sp. was also undertaken. The structures of four new halichondrins (3.13 - 3.16), isolated from Lissodendoryx sp., have been determined from spectral data. All of these compounds are very similar to known B series halichondrins, with differences occurring only beyond carbon 44. As biological activity has been shown to be derived from the portion of the molecule between carbons 1 and 35, they all retain good activity in the P388 assay as expected. A new siderophore, petrobactin sulfonate (4.2), was characterised, along with three cyclic imide siderophore derivatives (4.3 - 4.5). Petrobactin sulfonate is the first marine siderophore containing a sulfonated 3,4-dihydroxy aromatic ring. The structures were elucidated from spectral data, resulting in a revision of the NMR assignments of petrobactin.

No description available.

Short Tandem Repeat (STR) analysis has become a valuable tool in identifying the source of biological stains, particularly from the investigation of sexual assault crimes. Difficulties in analysis arise primarily in the interpretation of mixed genotypes when cell separation of the sexual assailant's sperm from the victim's cells is incomplete. The forensic community continues to seek improvements in cell separation methods from mixtures for DNA typing. This report describes the use of laser microdissection (LMD) for the separation of pure populations of spermatozoa from two-donor cell mixtures. In this study, cell separation was demonstrated by microscopic identification of histologically stained spermatozoa and female buccal cell mixtures, and STR analysis of DNA obtained from the separated sperm cells. Clear profiles of the male donor were obtained with the absence of any additional alleles from the female donor. Five histological stains were evaluated for use with LMD and DNA analysis: hematoxylin/eosin, nuclear fast red/picroindigocarmine, methyl green, Wright's stain, and acridine orange. Hematoxylin/eosin out-performed all other stains however nuclear fast red/picroindigocarmine could be used satisfactorily with STR analysis. In addition, three DNA isolation methods were evaluated for LMD collected cells: QIAamp (Qiagen), microLYSIS (Microzone Ltd.) and Lyse-N-Go (Pierce Chemical Co.). MicroLYSIS performed poorly, yielding low levels of PCR product. Lyse-N-Go extraction was effective for the recovery of DNA from LMD collected sperm cells while QIAamp isolation performed best for the recovery of DNA from LMD collected epithelial cells. LMD is shown to be an effective, low-manipulation separation method that enables the recovery of sperm while excluding epithelial cell DNA.

No description available.

No description available.

Thesis (Ph. D.)--University of Lund, 1995. / Published dissertation. Includes bibliographical references.

Thesis (Ph. D.)--University of Lund, 1995. / Published dissertation. Includes bibliographical references.

This work focuses on the integration of microfluidics and dielectrophoresis(DEP) with the principles of field flow fractionation (FFF) to create a continuous-flow isolator for rare and viable circulating tumor cells (CTCs) from peripheral blood mononuclear cells (PBMNs) drawn from cancer patients. The method exploits differences in the plasma membrane capacitances of tumor and blood cells, which correspond to differences in the membrane surface areas of these cell types. DEP-FFF was first adapted to measure cell membrane capacitance, cell density and deformability profiles of cell populations. These properties of the NCI-60 panel of cancer cell types, which represents the wide functional diversity of cancers from 9 organs and leukemia, were compared with the normal cell subpopulations of peripheral blood. In every case, the NCI-60 cells exhibited membrane capacitance characteristics that were distinct from blood and, as a result, they could be isolated from blood by DEP. The heightened cancer cell membrane capacitances correlated strongly with membrane-rich morphological characteristics at their growth sites, including cell flattening, dendritic projections, and surface wrinkling. Following harvest from culture and maintenance in suspension, cancer cells were found to shed cytoplasm and membrane area over time and the suspended cell populations developed considerable morphological diversity. The shedding changed the cancer cell DEP properties but they could still be isolated from blood cells. A similar shedding process in the peripheral blood could account for the surprisingly wide morphological diversity seen among circulating cells isolated from clinical specimens. A continuous flow DEP-FFF method was devised to exploit these findings by allowing CTCs to be isolated from the nucleated cells of 10 mL clinical blood specimens in 40 minutes, an extremely high throughput rate for a microfluidic-based method. Cultured cancer cells could be isolated at 70-80% efficiency using this approach and the isolation of CTCs from clinical specimens was demonstrated. The results showed that the continuous DEP-FFF method delivers unmodified, viable CTCs for analysis, is perhaps universally applicable to isolation of CTCs from different cancer types and is independent of surface antigens - making it suitable for cells lacking the epithelial markers used in currently accepted CTC isolation methods. / text