THE EFFECTS OF ANTIGENIC ISOMERISM AND ANTIGENIC AGGREGATION ON THE ANTIBODY RESPONSE IN INBRED RATS *

There is no evidence for genetic control of the antibody response to the d -amino acid polypeptide poly(d Glu⁵²d Lys³³d Tyr¹⁵) in contrast to the case of the l -isomer in which the antibody response is genetically controlled and linked to the major histocompatibility locus. There is also no crossreactivity between the l - and d -isomers of the polypeptide in the induction of the immune response. Aggregation of the l -isomer with methylated bovine serum albumin (MeBSA) abolished the pattern of genetic control by increasing antibody formation in the low responders and by decreasing it in the high responders. Aggregation of the d -isomer increased rather uniformly the antibody responses of all strains, except the moderately responding WF strain. The antibody response to the MeBSA in the aggregates was uniformly low, although there was a strain dependent variation in the antibody response to MeBSA alone.     

Zellvitalität nach hyperbarer Xenon-Konservierung von Kaninchennieren über einen Zeitraum von 8 Tagen bei 2°C

Zusammenfassung Kaninchennieren wurden bel 2°C über 8 Tage in Druckbehältern trocken und steril gelagert. Als Gase wurden verwandt: Sauerstoff, Helium, Stickstoff und Xenon. Der Überdruck betrug 2–3 atü. Mit einer Xenonkonservierung gelingt es, die Zellvitalität und Struktur in Kaninchennieren über 8 Tage weitgehend zu erhalten.

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Summary Storage of rabbit kidneys was maintained over 8 days at sterile and dry conditions at 2°C and at a pressure of 2–3 atm. We used as storage media: oxygen, helium, nitrogen und xenon. By xenonpreservation it was possible to maintain the cellulary viability and the structure of rabbit kidneys over a period of 8 days without severe disturbances.

     

Assessment of left ventricular function by breath-hold cine MR imaging: Comparison of different steady-state free precession sequences

PURPOSE: To compare steady-state free precession (SSFP) sequence protocols with different acquisition times (TA) and temporal resolutions (tRes) due to the implementation of a view sharing technique called shared phases for the assessment of left ventricular (LV) function by breath-hold cine magnetic resonance (MR) imaging. MATERIALS AND METHODS: End-diastolic and end-systolic volumes (EDV, ESV) were measured in contiguous short-axis slices with a thickness of 8 mm acquired in 10 healthy male volunteers. The following true fast imaging with steady-state precession (TrueFISP) sequence protocols were compared: protocol A) internal standard of reference, segmented: tRes 34.5 msec, TA 18 beats per slice; protocol B) segmented, shared phases: tRes 34.1 msec, TA 10 beats per slice; and protocol C) real-time, shared phases, parallel acquisition technique: tRes 47.3 msec, TA 24 beats for 12 slices covering the entire left ventricle. RESULTS: Phase sharing leads to a significant decrease in EDV, stroke volume (SV), and ejection fraction (EF) (median difference -7.0 mL [*], -9.6 mL, and -3.4%, respectively, for protocol B; -15.3 mL, -13.3 mL, and -2.4% for protocol C; P = 0.002, *P = 0.021). The observed median difference of real-time EDV and SV estimates is of clinical relevance. Real-time cine MR imaging shows a greater variability of EDV and SV. No relevant differences in ESV were observed. CONCLUSION: The true cine frame duration of both shared phases sequence protocols exceeds the period of isovolumetric contraction (IVCT) of the left ventricle resulting in a systematic and significant underestimation of EDV and consequently SV and EF. SSFP sequence protocol parameters, particularly tRes and use of view sharing techniques, should therefore be known at follow-up examinations in order to be able to assess LV remodeling in patients with heart failure.     

Über primäre Wirkungen von Dimethylaminoazobenzol auf den Pyridinnukleotidstoffwechsel der Leber

Ohne Zusammenfassung     

Protection of mice against tick-borne encephalitis by different classes of immunoglobulins

Summary The protective capacities of IgM and IgG immunoglobulins from fractionated human or mouse sera were investigated in tests with tick-borne encephalitis virus. Mice were resistant to challenge with tick-borne encephalitis virus if previously inoculated with specific immunoglobulins but not nonspecific immunoglobulins. The protective ability of IgM, whether derived from mouse or human sera, was only about 1/40 of that of IgG preparations adjusted to the same haemagglutination inhibition or neutralising titres.

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Schutzwirkung verschiedener Klassen von Immunglobulinen gegen die Frühsommer-Meningoenzephalomyelitis bei Mäusen

Zusammenfassung Fraktionen von IgM und IgG aus Menschen-und Mäuseserum wurden auf ihre Schutzwirkung gegen die durch Zecken übertragbare Enzephalitis untersucht. Mäuse konnten durch spezifische Immunglobulinklassen gegen Enzephalitis geschützt werden, wenn die Immunglobuline vor der Infektion gegeben wurden. Unspezifische Immunglobuline waren wirkungslos. Dabei war die Schutzwirkung von IgM nur 1/40 der von IgG-Präparationen des gleichen Hämagglutinationshemmungs-bzw. Neutralisationstiters.