High pressure/temperature treatments to inactivate highly infectious prion subpopulations

High hydrostatic pressure can be used for gentle pasteurization of food as well as a physical parameter to study the stability and energetics of biomolecules. High pressure has been recently postulated as a feasible technology to decontaminate scrapie infectious materials. Here we discuss the kinetic parameters driving the inactivation of the Transmissible Spongiform Encephalopathy agents and the perspectives of pressure as a thermodynamic parameter to obtain a deeper insight into the aggregation of the 263K strain of scrapie. At 60–80 °C an efficient pressure inactivation of infectious scrapie prions was observed during short pressure treatments at 800 MPa (3 × 5 min cycles). However, discrepancies between in vivo infectivity counts and the results of an enzyme immunoassay further revealed that the infectivity was inactivated faster and much more efficiently than PrP^res was degraded, indicating that pressure affects a highly infectious subpopulation of scrapie prions.

Industrial relevance

Conventional inactivation methods for the agents of the Transmissible Spongiform Encephalopathies are not compatible with food processing due to the required aggressive conditions. High pressure assisted thermal sterilization methods are nowadays attracting attention as a food preservation technology able to preserve quality attributes. Here the stark effects in the secondary prion structure of high pressure combined with heat below the usual denaturing conditions were investigated with specific tests. This technology was proven to be a feasible alternative to achieve the decontamination of TSE risk materials at milder conditions. Kinetic data provided here should be useful to establish criteria to inactivate prions under pressure.     

Antibodies in patients with inflammatory bowel disease and the apparent influence of medications

Patients with inflammatory bowel disease (IBD) are known to have increased antibodies to several food and bacterial antigens. To assess selected isotype contributions in greater detail, we examined the concentrations of IgA, IgG, IgE, and IgG4 antibodies to five selected antigens, two of bacterial and three of food origin. Thirty patients with IBD and thirty matched healthy controls were studied. Most antibodies were increased in IBD patients compared to controls. Statistically significant increases were more frequent in Crohn's disease (CD) than in ulcerative colitis (UC). An unexpected finding was that IBD patients treated with sulfasalazine had statistically higher levels of most IgA antibodies than healthy controls, while steroid treated patients had lower levels. These findings suggest differing effects on the immune systems of IBD patients by each of these commonly used drugs.     

Röntgenographische Elastizitätskonstanten von Stählen bei erhöhter Probentemperatur

Messung der Gitterebenenabstände an der (211)-lnterferenz bei Raumtemperatur und 300°C an Zugproben der Stähle 15 Mo 3, 13 CrMo 44 und 34 CrMo 4. Ermittlung der Eigenspannungen, der thermischen Ausdehnungskoeffizienten und der röntgenographischen Elastizitätskonstanten. 1/2 s₂ (211) hat bei 300°C einen um rd. 20% kleineren Wert als bei Raumtemperatur. Die Ursache des Abfalls wird diskutiert.     

The safety of local anesthesia and outpatient treatment: a controlled study of induced abortion by vacuum aspiration

The safety of early vacuum aspiration performed as an outpatient procedure using local anesthesia was examined in a controlled study sponsored by the World Health Organization and undertaken in two centers in Yugoslavia and Singapore. The sample consisted of healthy women whose pregnancies were between 7 and 12 weeks in duration. Follow-up four weeks after abortion was nearly 100 percent in both centers. No important differences in complication rates were found between the different types of services and anesthesia, even though overall complication rates differed markedly between centers. Overnight postabortion observation was not associated with any decrease in complications.     

Synthesis, physicochemical characterization, and crystallization of a putative retro-coiled coil

OBJECTIVES: The purposes of this study were to investigate the use of radial artery applanation tonometry and a generalized transfer function for the assessment of central aortic pressure augmentation in subjects taking commonly used antihypertensive agents (angiotensin-converting enzyme inhibitors, beta-adrenergic blockers, Ca2+ antagonists, diuretic therapy). BACKGROUND: Applanation tonometry of the radial artery with a generalized transfer function has been proposed as a means of assessing central aortic blood pressure. Recently, a commercial apparatus based on this technique has become available; we therefore examined the effect of a generalized transfer function on derived central aortic pressure compared with measured brachial blood pressures and also investigated the potential of this technique to assess the influence of differing drug therapy. METHODS: Two hundred and sixty-two hypertensive patients on stable medication were studied using the PWV Medical Blood Pressure Analysis System (version 2, DAT-1). RESULTS: In univariate analysis, augmentation index showed association with age, sex, height and heart rate. In multivariate analysis, diastolic blood pressure and age (positively), height and heart rate (negatively) and sex were significantly associated. After adjustment for these variables, pressure augmentation was not associated with any antihypertensive treatment investigated. Linear relationships were demonstrated between brachial blood pressures and corresponding central pressures derived by transfer function methods. CONCLUSIONS: Our findings suggest that if adjustment for central-peripheral pressure difference is necessary, simple linear relationships may be sufficient. Age, heart rate and height but not the class of antihypertensive medication affected the degree of pressure augmentation observed using this technique.