The inactivation of single-particle stocks of human (type 2, Wa) and simian (SA-ll) rotaviruses by chlorine dioxide was investigated. Experiments were conducted at 4°C in a standard phosphate-carbonate buffer. Both virus types were rapidly inactivated, within 20 s under alkaline conditions, when chlorine dioxide concentrations ranging from 0.05 to 0.2 mg/liter were used. Similar reductions of 105-fold in infectivity required additional exposure time of 120 s at 0.2 mg/liter for Wa and at 0.5 mg/liter for SA-li, respectively, at pH 6.0. The inactivation of both virus types was moderate at neutral pH, and the sensitivities to chlorine dioxide were similar. The observed enhancement of virucidal efficiency with increasing pH was contrary to earlier findings with chlorineand ozone-treated rotavirus particles, where efficiencies decreased with increasing alkalinity. Comparison of 99.9% virus inactivation times revealed ozone to be the most effective virucidal agent among these three disinfectants.

Drug-loaded proteinoid microspheres were freeze-dried to facilitate shipping and handling and to enable long term storage. Heparin was chosen as the model drug in developing the optimum lyophilization process. The factors influencing the integrity of either heparin-loaded or unloaded ('empty') proteinoid microspheres during freeze-drying were determined, with emphasis on: selecting an optimum freezing and resuspending temperature; choosing an appropriate cryoprotectant and its optimum concentration in the formulation; and, designing a suitable method for formulating the microspheres. Freezing at/below -70 degrees C was found to minimize damage to the microspheres. Addition of sugars, such as trehalose and lactose, as cryoprotectants, further increased the stability of the heparin-loaded microspheres during freeze-drying. The optimum trehalose or lactose concentrations were determined to be 5% (w/v). Using the optimumized lyophilization process described in this manuscript, microspheres remained intact during freeze-drying. The freeze-dried microspheres were stable for at least three months post-lyophilization.

Group A streptococcal peptidoglycan has previously been shown to be arthritogenic in rats and has been implicated as a structure present in a class of possible etiologic agents for rheumatoid arthritis. The present study reports that conditioned medium from human monocytes, after interaction with cell wall sonicates of four group A streptococcal strains, stimulates the plasminogen activator (PA) activity of nonrheumatoid synovial fibroblasts. Low concentrations of N-acetylmuramyl-L-alanyl-D isoglutamine (muramyl dipeptide) can also generate this synovial activator (SA) activity from human monocytes. Preliminary biochemical data suggest that the SA activity is distinct from interferon-gamma, interleukin 1, and interleukin 2. These results indicate that agents that are arthritogenic in rats can modulate human synovial fibroblast functions via monocytes. The findings are proposed to have possible significance for an understanding of the cellular interactions involved in the formation and function of the rheumatoid pannus, because PA has been invoked as possibly being generally important for the processes of cell migration, tissue remodeling, and inflammation.

The inactivation of a large-focus-forming variant of hepatitis A virus (HM-175) by ozone was investigated. Experiments using mainly single-particle virus preparations suspended in phosphate-carbonate buffer were conducted over a range of pH levels (6-8) at 4 degrees C. Viral enumerations involved the use of a radioimmunofocus assay. While some tolerance to lower (i.e., 0.1-0.5 mg/L) ozone residuals was noted, the exposure of virus particles to ozone concentrations of 1 mg/L or greater at all pH levels resulted in their complete (5 log) inactivation within 60 s. The pH-related effects that were observed were not considered to be significant.

Human white blood cells produced interferon (IFN) in response to Staphylococcus enterotoxin B (SEB) in vitro. The majority of this IFN was classified as IFN-gamma by virtue of its acid instability, non-neutralization by antisera recognizing alpha or beta IFNs and species-specificity for human cells. The IFN activity appeared after 3-6 hr and reached maximum levels between day 2 and 3. The SEB-induced IFN was partially purified to about 10(5.5) units/mg protein by chromatography on controlled pore glass beads (CPG) and Sephadex G-100 columns. While the CPG column purification step increased the specific activity 50 to 100-fold, two peaks of IFN activity were eluted from the Sephadex G-100 column. The first activity peak containing the majority of the loaded IFN appeared to be active only on human cells and was not neutralized by anti-HuIFN-alpha and had an apparent molecular weight of about 44,000 daltons, the second peak (about 5% of the loaded IFN) showed antiviral activity on both human and bovine cells, was at least partially neutralizing by anti-HuIFN-alpha and had an estimated molecular weight of 21,000 daltons. The specific activity in the first IFN peak was about 30-fold increased by the gel filtration chromatography with a recovery of approximately 60-80%.