Survival rate of Suid herpesvirus (SuHV-1, Aujeszky's disease virus, ADV) in composted sewage sludge.

Sewage sludge constitutes a source of valuable biogenic raw materials, but it is a carrier of many pathogenic microorganisms and viruses. Subjected to an effective sanitization by means of the process of composting, it is suitable to use in agriculture as fertilizers. The aim of this study was to observe the survival rate of Suid Herpesvirus under the influence of the temperature alone (water bath) as well as in sewage sludge subjected to the process of composting (pile). The samples were taken at different time intervals, and the virus titres were determined. The viruses survived considerably longer under laboratory conditions: at 30 degrees C as long as 21 days, at 40 degrees C - 93 hours, and at 50 degrees C - less than an hour. In the compost pile, in spite of the lack of the thermophylic phase, the total survival time of the viruses ranged from 34 to 44.5 hours, which indicates the vast importance of other physicochemical factors, apart from the temperature, contributing to virus inactivation.

Survival of BPV and Aujeszky's disease viruses in meat wastes subjected to different sanitization processes.

The effect of composting and anaerobic fermentations under meso- and thermophylic conditions (37 degrees and 55 degrees C) on the survival of bovine parvovirus (BPV) and Aujeszky's disease viruse (ADV) in meat wastes has been examined in this study. Viruses were adsorbed on filters and introduced into carriers which were made of meat fragments of different sizes and bones or in the form of suspension they were introduced into the biomass in the course of processes of waste treatment. Carriers were removed at appropriate time intervals and virus titres were determined. The thermoresistant parvovirus survived for the longest time during mesophylic fermentation (almost 70 days), slightly shorter during composting (7-9.5 days depending on the type of carrier) and for the shortest time--at 55 degrees C (46-76 hours). Its inactivation rate was the fastest in a suspension, slower in meat and bone carriers. ADV inactivation proceeded considerably faster, as compared with BPV. Its active particles were not detected as early as in the 30th minute of thermophylic fermentation, the 6th hour of mesophylic fermentation and at the first sampling time during composting (at the 72nd hour). Total survival time ranged from 50 min to 13 hours. All the tested technologies enabled the effective elimination of ADV and on average twofold decrease in BPV titre. From the study conducted it follows that of both viruses, the BPV should be applied for validation processes of methods used in meat waste processing, particularly if this refers to methods where higher temperature is the factor inactivating pathogens.

Antibodies to recombinant fragment 212-276 of protein C specifically recognize the intact human molecule.

The peptide fragment Pro212-Ile276 of human protein C was produced as a part of a fusion protein in Escherichia coli. The identity of the peptide was confirmed by immunoblotting experiments using specific antibodies to intact protein C. The peptide Pro212-Ile276 was isolated from the fusion protein after mild hydrolysis with formic acid by gel filtration and reverse-phase HPLC. This peptide fragment was used to produce antibodies specific for the heavy chain of protein C which recognized native protein C present in blood plasma. Antibodies to intact protein C reacted also with the Pro212-Ile276 peptide fragment, indicating that this region is immunogenic in intact protein C and may represent a native epitope.

Comparison of platelet aggregability and P-selectin surface expression on platelets isolated by different methods.

Three methods commonly used for isolation of blood platelets from plasma were compared. Platelets were isolated by: 1) a washing method; 2) a method of metrizamide-gradient centrifugation; 3) a modified method of gel-filtration. The last method employed BSA-Sepharose gel instead of routinely used Sepharose gel saturated with BSA. BSA-Sepharose gel was prepared by covalent binding of thermally deactivated BSA to CNBr-activated Sepharose 2B. In contrast to platelets isolated by the other methods, an aggregability of the gel-filtered platelets and control platelets in plasma, both activated with ADP, were comparable. When expression of P-selectin on the surface of freshly isolated platelets was examined, the gel-filtered platelets exhibited the same extent of fluorescence signal as platelets in the citrated blood, whereas platelets isolated by the other methods exhibited twice the extent of the signal. The methods involving the centrifugation process cause a low but a significant platelet activation.

Activation of blood platelets after percutaneous transluminal coronary angioplasty and coronary artery bypass graft surgery.

We have evaluated the activation of platelets in blood samples taken from patients with stable angina undergoing balloon angioplasty (percutaneous transluminal coronary angioplasty [PTCA]) (n=11) or coronary artery bypass grafting (CABG) under hypothermic (n=11) or normothermic conditions (n=11). We have found that surface expression of P-selectin on platelets in whole blood from PTCA patients upon thrombin treatment was significantly reduced, as compared with control platelets from healthy subjects. This effect was partially reversed when platelets washed from the same blood sample were used, but even then P-selectin expression was significantly lower in PTCA patients than it was in control subjects. There was a significant increase in basal expression of P-selectin in blood platelets taken from patients who underwent CABG under normothermic conditions (warm blood cardioplegia) as opposed to hypothermic patients (cold crystalloid cardioplegia). These platelets retain the ability to respond to agonists, although to a much lower extent than do those from healthy control donors. The surface exposure of P-selectin on resting and thrombin-treated platelets isolated from CABG surgery patients was not different from that of the control platelets. The adhesion to fibrinogen of resting and thrombin-treated platelets from patients who underwent balloon angioplasty as well as CABG surgery under normothermic and hypothermic conditions was significantly reduced when compared with the fibrinogen of the control platelets. These results suggest that the function of platelet fibrinogen receptor is impaired in patients with stable angina pectoris and that PTCA and CABG surgery activates platelets.