62 research outputs found
Monoclonal antibodies against human CD34 antigens do not cross-react with ovine umbilical cord blood cells
CD34 is a cell surface glycoprotein expressed by hematopoietic progenitors and endothelial cells. It is widely used in the clinic for isolation of human hematopoietic stem cells. In recent years large animals are gaining increasing importance in biomedical research for the study and therapy of human diseases. Sheep has proved to be an useful experimental model for preclinical trials in transplantation procedures. Unfortunately, the lack of specie-specific monoclonal antibodies (MABS) recognizing hemopoietic progenitor cells hampers the use of this animal in experimental hematology. The aim of this paper was to determine whether commercial monoclonal antibodies specific for human CD34 molecule could cross-react with hematopoietic progenitor cells (HPC) present in sheep umbilical cord blood (UCB). Six anti-human CD34 MABS, recognizing the three different epitope classes, were tested in flow cytometry on purified mononuclear cells (MNC) isolated from cord blood of both species. None of the MABS used in this trial seemed to be able to identify HPC from sheep UCB. These data suggest that the panel of monoclonal antibodies used for cross reactivity detection has to be expanded with recently produced reagents. Further studies should be directed towards the production of ovine specific anti CD34 MABS
M-phase promoting factor (MPF) and mitogen activated protein kinases (MAPK) activities of domestic cat oocytes matured <i>in vitro</i> and <i>in vivo</i>
This work was undertaken in order to examine M-phase promoting factor (MPF) and mitogen-activated protein kinases (MAPK) activities during meiotic progression of cat oocytes cultured in two different media for two different incubation times and preovulatory cat oocytes that reached MII in vivo. Oocytes recovered from ovaries of ovariectomized cats were cultured either in TCM 199 or SOF for 24 h and 40 h. In vivo matured oocytes were recovered by follicular aspiration from ovaries of domestic cats ovariectomized 24 h to 26 h after hormonal treatment. Results showed that the kinetic of MPF and MAPK activity was similar during meiotic progression of cat oocytes matured in TCM 199 and SOF. After 24 h of incubation, MII oocytes had significantly (p < 0.001) higher MPF and MAPK levels than MII oocytes cultured for 40 h in both culture media. MPF and MAPK activity was significantly (p < 0.01) lower in the oocytes matured in vitro than in those matured in vivo. This study provides evidence that the two different maturation media did not determine differences in MPF and MAPK fluctuations and levels during meiotic progression of cat oocytes and that the time of maturation influenced the level of the two kinases. Moreover, it shows that MPF and MPK activity is higher in in vivo matured oocytes than in in vitro matured oocytes, suggesting a possible incomplete cytoplasmic maturation after culture
Stress responses in lambs castrated with three different methods
The present work was conducted to evaluate the animal response to stress in lambs caused by three
different castration techniques. Forty-six male lambs aged 4-5 months were randomly allocated to one
of four groups including Burdizzo (B), scrotal ablation (SA), orchiectomy (OR) and control handling
(H). Local anaesthesia (lidocaine 2%) was administered in both spermatic cords and the scrotal neck
of lambs before each treatment. Blood samples were collected at -30, -10, +1, +20, +40, +60, +120,
and +180 minutes. Serum cortisol concentrations were determined using a competitive immunoassay
and the area under the curve (AUC) was calculated for each lamb. The following biochemical parameters
were assayed for each animal at each time point: alanine aminotransferase (ALT), aspartate aminotransferase
(AST), lactate dehydrogenase (LDH), creatine kinase (CK) and glucose (GLU). The time
needed for total lesion resolution and weight gain of each animal was recorded. Orchiectomy elicits the
greatest cortisol response, significantly greater than that seen in similarly handled controls (P≤0.01),
Burdizzo and scrotal ablation groups (P≤0.05). The serum cortisol AUC was higher in the scrotal ablation
group (P≤0.05) than controls, but lower than in the orchiectomy group (P≤0.05). The Burdizzo group
didn’t differ from controls. Serum glucose levels of the castrated lambs differed significantly from the
control group, following a trend similar to cortisol. No change was seen in ALT, AST, LDH or CK. No difference
in weight gain was seen among the groups. Our results suggest that use of the Burdizzo is the
preferable castration technique for adult lambs, while scrotal ablation is a valid surgical alternative to
orchiectomy and permits more rapid wound healing that is ideal for extensive management where flocks
are not under close observation
Scaling-up targets for a threatened butterfly: A method to define Favourable Reference Values
Film forming PVA-based cleaning systems for the removal of corrosion products from historical bronzes
Innovative methods for the removal, and occasionally care, of pressure sensitive adhesive tapes from contemporary drawings
Facilitating the conservation treatment of Eva Hesse's Addendum through practice-based research, including a comparative evaluation of novel cleaning systems
Abstract This paper describes the methodology and practice-based research underpinning the development of a successful cleaning strategy for Eva Hesse's sculpture Addendum (1967, Tate Collection T02394). Research strands included: technical and art historical investigations to determine the materials and construction of the work of art and to define the aims of the conservation treatment; the production, soiling and accelerated ageing of mock-up samples using contemporary equivalent materials; and the systematic, iterative evaluation of soiling removal systems, which were further refined for appropriate use on the work of art. The comparative cleaning system evaluation was employed to determine options which offered optimal soiling removal efficacy and posed minimal risk to the work of art. Newly developed Nanorestore Gel® Peggy series (i.e. polyvinyl alcohol (PVA) and polyvinyl alcohol/polyvinylpyrrolidone (PVA/PVP)-based hydrogels), designed for the cleaning of modern and contemporary art, were evaluated with a range of other gels, emulsifiers and cosmetic sponges and assessed through a combination of empirical observation, microscopy and spectroscopic techniques. Promising options, combined with tailored aqueous phases derived from trials on mock-up samples, were then evaluated on discreet areas of the sculpture. After extensive testing, the top papier mâché section of Addendum was surface cleaned using an aqueous solution applied with cosmetic sponges, and the ropes were surface cleaned using a modified version of Nanorestore Gel® Peggy 5 (PVA/PVP) loaded with a tailored aqueous solution. The optimisation of this hydrogel, combined with the extensive supporting research, enabled the successful, low-risk, conservation treatment of Addendum for the first time since acquisition
Reviving WHAAM! a comparative evaluation of cleaning systems for the conservation treatment of Roy Lichtenstein's iconic painting
Abstract Roy Lichtenstein's Whaam! (1963) is an iconic artwork in Tate's collection (T00897). Over the past 50 years, the painting has been on almost continuous display and had accrued a layer of deposited soiling, which resulted in the dampening of Lichtenstein's vibrant colours and the masking of numerous subtleties across the painting surface. This paper outlines the design and execution of an optimal soiling removal strategy for this challenging work; utilising collaborative, practice-based research. The conservation treatment employed was derived through an iterative process that reflected and supported the conservation decision-making process. The research strands included: technical and art historical investigations to determine the materials and construction of Whaam! and to define the aims of the conservation treatment; preparation of accelerated aged and artificially soiled test (mock-up) paint samples based on contemporary equivalent materials and a comparative evaluation of a range of established and novel soil-removal systems, followed by further tailoring for use on the work of art. The range of cleaning systems evaluated included free-solvents, gels and emulsifiers; which were documented using star diagrams, digital microscopy and infrared spectroscopy. After a rigorous process of assessment and refinement, the strategy taken forward to Whaam! included the use of a polyvinyl alcohol-based polymeric hydrogel (Nanorestore Gel® Peggy 6), uploaded with tailored aqueous solutions. This process facilitated a low risk, controlled and even-removal of the soiling layer, enabling the successful treatment of this sensitive painting for the first time in the painting's history
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