CRITICAL RELATIONSHIPS BETWEEN CONSTITUENTS OF THE ANTIGEN-ADJUVANT EMULSION AFFECTING EXPERIMENTAL ALLERGIC ENCEPHALOMYELITIS IN A COMPLETELY SUSCEPTIBLE MOUSE GENOTYPE

The production of EAE in the fully susceptible BSVS mouse genotype has been found to be dependent on the ratio of proteolipid antigen and adjuvant mycobacterial concentration as used in the emulsion, of the Freund type. Disturbance of this ratio, by manipulation of either component, by diminution or increase, results in a decrease in the frequency by which EAE is produced. Simultaneous reduction of antigen and mycobacteria, so that the ratio remains unchanged, retains the full EAE-producing power of the emulsion. The limit of this has not been ascertained. Emulsifying agents have been found to restrict further the permissible limits of the antigen-mycobacterial ratio for full EAE production. Such effects of the emulsifier have been found to vary with the qualitative nature of the emulsifier. Aquaphor has been found to be less restrictive than falba. These phenomena, systematically analyzed here for the mouse, may have an application for other antigen-adjuvant systems and for other hosts

Determining the Critical Window of Influence of PCB Perinatally on Behavioral and Hormonal Development in Sprague-Dawley Rat Pups

Polychlorinated biphenyls (PCB) had widespread use in the United States in commercial manufacturing in the United States until the late 1970s. Even though they were banned, measurable amounts can still be found in the environment and food sources. PCB has known effects on altering hormone development and behavior in the species Rattus norvegicus. To determine the most crucial developmental time of exposure to PCB in Sprague-Dawley rat pups, rat pups were exposed to PCB at differing weeks of either gestation period or the first postnatal week. Behavioral tests were performed for the different rat pups, as well as blood serum was analyzed for the concentration of thyroid hormone. This paper presents data for PCB exposed pups that were tested for play behavior on PND 22. Statistical tests were used to determine the week of PCB exposure with the greatest effects on the rat pups. The results are that exposure of PCB led to a significant increase in the play behavior of the pups. The dorsal contact play behavior was significantly altered by PCB, while the pin behavior was not significantly altered. The critical window for PCB exposure was not identified, but it can be seen that PCB alters dorsal contact behavior in exposed rat pups

Correlation between microstructure and magnetotransport in organic semiconductor spin valve structures

We have studied magnetotransport in organic-inorganic hybrid multilayer junctions. In these devices, the organic semiconductor (OSC) Alq$_3$ (tris(8-hydroxyquinoline) aluminum) formed a spacer layer between ferromagnetic (FM) Co and Fe layers. The thickness of the Alq$_3$ layer was in the range of 50-150 nm. Positive magnetoresistance (MR) was observed at 4.2 K in a current perpendicular to plane geometry, and these effects persisted up to room temperature. The devices' microstructure was studied by X-ray reflectometry, Auger electron spectroscopy and polarized neutron reflectometry (PNR). The films show well-defined layers with modest average chemical roughness (3-5 nm) at the interface between the Alq$_3$ and the surrounding FM layers. Reflectometry shows that larger MR effects are associated with smaller FM/Alq$_3$ interface width (both chemical and magnetic) and a magnetically dead layer at the Alq$_3$/Fe interface. The PNR data also show that the Co layer, which was deposited on top of the Alq$_3$, adopts a multi-domain magnetic structure at low field and a perfect anti-parallel state is not obtained. The origins of the observed MR are discussed and attributed to spin coherent transport. A lower bound for the spin diffusion length in Alq$_3$ was estimated as $43 \pm 5$ nm at 80 K. However, the subtle correlations between microstructure and magnetotransport indicate the importance of interfacial effects in these systems.Comment: 21 pages, 11 figures and 2 table

Serological detection and identification of rice blast

Monoclonal antibodies (MAbs) useful in the serological detection and identification of rice blast were produced by hybridoma cells formed from fusions of myeloma cells with splenocytes from BALB/c mice immunized with an extract of a liquid culture fluid of an isolate of Pyricularia grisea race IB-49. These MAbs reacted similarly with the antigens in various serological techniques used, and did not cross react with any unrelated fungal isolates representing 11 genera, but reacted positively with all 20 races or isolates of P. grisea. The MAbs could detect homologous antigen at about 60 ng fungal protein/ml and a 5-fold dilution of the extracts of infected rice tissue by ELISA. In accordance with another embodiment of the present invention, hybridoma lines secreting antibodies positive for the immunogen and negative for healthy rice tissue were selected from three independent fusions of NS-1 myeloma cells with splenocytes from mice immunized with crushed conidial suspensions of P. grisea race IB-49. MAbs secreted from cell line 4G11, deposited with ATCC as HB11178, reacted strongly with conidial antigen. In cross-reaction tests with ELISA, MAb 4G11 reacted negatively with isolates representing 11 fungal genera and reacted positively with 11 and 12 isolates of P. grisea in ELISA and IFA, respectively. MAb 4G11 could detect homologous conidial antigen at 14-70 ng/ml, 10-20 conidia/well, and the fungal antigen in infected rice tissue in ELISA

Mathematical modelling of tissue-engineering angiogenesis

We present a mathematical model for the vascularisation of a porous scaffold following implantation in vivo. The model is given as a set of coupled non-linear ordinary differential equations (ODEs) which describe the evolution in time of the amounts of the different tissue constituents inside the scaffold. Bifurcation analyses reveal how the extent of scaffold vascularisation changes as a function of the parameter values. For example, it is shown how the loss of seeded cells arising from slow infiltration of vascular tissue can be overcome using a prevascularisation strategy consisting of seeding the scaffold with vascular cells. Using certain assumptions it is shown how the system can be simplified to one which is partially tractable and for which some analysis is given. Limited comparison is also given of the model solutions with experimental data from the chick chorioallantoic membrane (CAM) assay

Influence of Perinatal Exposure to a Polychlorinated Biphenyl Mixture on Learning and Memory, Hippocampal Size, and Estrogen Receptor-Beta Expression

Author Institution: Department of Biological Sciences, Bowling Green State UniversityAuthor Institution: Department of Psychology, Bowling Green State UniversityPerinatal exposure to PCB has been reported to cause a variety of health effects including endocrine disruption, and immunologic, reproductive, neurologic, and behavioral deficits. In the present study, a mixture of two PCB congeners, one noncoplanar (PCB 47) and one coplanar (PCB 77), were administered to young female Sprague-Dawley rats by route of maternal dietary consumption (either 12.5 ppm or 25.0 ppm, w/w). Impact on learning and memory were examined by radial arm maze on postnatal day 24-27. After behavioral tests were completed, the rats were transcardially perfused, and brains were excised. Immunohistochemistry for ER- β was carried out on free-floating sections. Sections were stained with cresyl violet stain, and hippocampal area was measured. A subjective comparison of staining density suggested a greater intensity of ER- β staining in female rat hippocampus exposed to PCB 47/77 at 25 ppm concentration. A decrease in the hippocampal area measurement was observed in the case of 25 ppm PCB exposed rats. Significant behavioral effects involving spatial learning and memory were not observed. However, animals exposed to PCB 47/77 at 25 ppm displayed a trend toward improved performance. Taken together, the combination in PCB exposed rats of reduced hippocampal size, increased ER-β concentration, and unaltered behavior suggests the existence of compensatory mechanisms in the animals