Combination therapy using reovirus type 3 and the chemo-therapeutic agent 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) is sufficient to cure approximately 80% of EL-4 lymphoma tumor-bearing BD2F1 male mice. Cured animals can be challenged with the EL-4 tumor, in the absence of the therapy, to yield 100% survival, whereas those challenged with heterologous tumor produce 0% survival. These results strongly suggest that a host-immune response is responsible for the observed therapeutic effect. Reovirus, a double-stranded RNA virus, is an efficient inducer of type I interferon. In an effort to determine the role of virus in this therapy, we substituted interferon-alpha (IFN-alpha) for reovirus in the therapy. Doses of IFN-alpha from 1000-10,000 U were capable of replacing reovirus to produce cure rates similar to reovirus. Spleen cells isolated from therapy-treated animals demonstrated high levels of cytotoxicity against the natural killer cell-sensitive cell line YAC-1, but not against EL-4 tumor. In vitro stimulation of isolated spleen cells by IFN-alpha resulted in a high level of natural killer cell activity, but no cytotoxicity against the EL-4 tumor. A significant antiproliferative effect against the EL-4 tumor in cell culture was demonstrated by IFN-alpha. Finally, therapy-treated, tumor-bearing mice that were injected with anti-IFN-alpha + -beta antibodies had similar survival levels as control mice, indicating that other cytokines might also play a role in promoting tumor killing. These investigations suggest that IFN-alpha may be a mediator of antitumor activity in the reovirus therapy system.
The morphology of peripheral nerve trauma is necessary to understand the resulting alterations in nerve function. Specific traumas, such as Vibration Syndrome, directly effect nerve function. Earily changes in myelinated axons closely resemble artifact damage due to preperations for electron microscopy. If the correlation between structure and function in traumatic conditions is to be studied, it is imperative to establish a fixation technique that yields consistently good results. It is also important to characterize fixation artifacts and correlate these changes to traumatic damages.Several techniques were compared in an attempt to illustrate the quality of morphology obtained from each fixation. Femoral nerve was microsurgically harvested from Sprague Dawley rats. The nerve was then cut into 1 mm segments and fixed by a variety of methods. The basic fixation was for 2.5 hr in 2.5% glutaraldehyde (GA), followed by 3 10-minute washes in 0.1 M cacodylate buffer pH 7.2, and 2.5 hr post-fixation in 1.0% OSO4 with an additional three washes in buffer.
Coagulase-negative Staphylococci have been implicated in late onset infection of breast prosthetic biomaterials used for augmentation and reconstruction. These prosthesis consist of either gel- or saline-filled smooth silicone rubber or textured polyurethane foam. The morphology of adhesion of staphylococci to the prosthesis is important in understanding their potential role in latent infection. Staphylococcus epidermidis rp62, a polysaccaride mucin producing strain, and Staphylococcus aureus strain 25923 are test organisms. A variety of fixative procedures employing en bloc reagents are compared in both SEM and TEM. Ruthenium red and alcian blue , uranyl acetate and ruthenium red with lysine have been used to preserve extracellular capsular/slime material in several bacterial species.Specimens of prosthetic material are incubated with cells for 18 hrs at 35°C in tryptic soy broth. For SEM, specimens are fixed in 2.5% glutaraldehyde (GA) for 2 hrs and post-fixed in 1% OsO4 for 2.5 hrs. This is followed by a graded ethanol series, critical point drying with CO2 and coating with gold/palladium.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.