[Prevention of HLA-alloimmunization of recipients of platelet concentrates]. / Prophylaxe von HLA-Alloimmunisierung bei Empfängern von Plättchen-Konzentraten.

Over a period of twelve months 7163 HLA-matched, single-donor platelet concentrates were prepared for 557 thrombocytopenic patients with hematologic or neoplastic disorders. 80% of the platelet recipients remained HLA-antibody-negative. Patients who developed HLA-antibodies received random platelets and/or leukocyte-contaminated blood-components simultaneously. Thus, HLA-matching, single-donor-preparations and removal of contaminating leukocytes may prevent HLA-alloimmunisation, and therefore improve the efficacy of platelet-transfusion.

[Clinical and serological characterization of Chlamydia-induced arthritis]. / Klinische und serologische Charakterisierung der Chlamydien-induzierten arthritis.

Chlamydia-induced arthritis was diagnosed in 32 patients (18 men and 14 women; mean age 33 [17-54] years). 13 were HLA-B27 positive. In 19 patients the arthritis was largely confined to one joint. Enthesopathies occurred in 14 patients, and in 13 sacroiliitis was diagnosed radiologically. The most frequent extra-articular changes affected the urogenital system (26 cases). The full Reiter syndrome was present in seven patients (four men, three women). All patients had serum antibodies against Chlamydia. In 16 patients Chlamydia was diagnosed as the causative organism by urogenital swab. Chlamydia-induced arthritis differs from other arthritides in the high proportion of HLA-B27 negative patients.

Specific serum IgA-antibodies in chlamydial-induced arthritis.

A cohort analytic study was performed to investigate serum IgA-class antibodies against Chlamydia in 24 patients with chlamydial-induced arthritis (CIA). IgA-class antibodies against chlamydial antigens were positive (titre greater than or equal to 1:16) in 23 of the 24 IgG-positive CIA-patients (96%) in contrast to 16 of 40 patients (40%) with other rheumatic diseases (ankylosing spondylitis n = 6; undifferentiated arthritis n = 11; rheumatoid arthritis n = 12; degenerative joint disease n = 11), also positive for IgG-class chlamydial antibodies. Both the presence of specific IgA-antibodies and their geometric mean titre (1:28 vs. 1:4) differed significantly (p less than 0.001) between the two groups.

Effect of space factors on Escherichia coli B/r cells.

Stationary phase cells of Escherichia coli B/r were inactivated when they were exposed to high vacuum (10(-6) torr). About 5% of the cells were still able to form a colony after 45 min exposure. Vacuum dried cells (0.5 torr, 120 min) show colony forming ability of 30% or more. They were inactivated to about 5% by further vacuum treatment. Vacuum treated cells showed higher permeability for various cell components. UV irradiated E. coli B/r cells in vacuum showed increased UV sensitivity. DNA-protein cross-links were preferentially formed in a vacuum. To obtain 63% of DNA cross linked with protein required 852 erg mm-2 (D37) of UV irradiation in suspension and only 72 erg mm-2 of UV irradiation in vacuum. The protein components of DNA-protein cross-links were hydrolysed with pronase E and the amino acids directly bonding to DNA were determined. The most important amino acids concerned in DNA-protein cross-links seem to be glycine and alanine, followed by aspartic acid (asparagine), glutamic acid (glutamine) and histidine. The sensitivity to X-rays of stationary phase E. coli B/r cells seems to depend on the remaining gas atmospheric in the vacuum since it varies with different pumping systems.

Membrane damage in dehydrated bacteria and its repair.

The dehydration of bacteria by vacuum exposure results in damage to the cell membrane. This membrane damage does not necessarily lead to cell death. A part of the dehydrated bacteria is capable of eliminating the membrane damage by repair processes. Repair can proceed rapidly under conditions that permit synthesizing activities. The kinetics of this repair process were studied by means of the membrane-mediated biosynthesis of the cell wall as well as by the recovery of resistance to small concentrations of lysozyme. Repair is a precondition for cell proliferation. At low temperature cells can conserve their membrane damage and the repair process can be initiated when conditions become favourable.

Viability of Bacillus subtilis spores exposed to space environment in the M-191 experiment system aboard Apollo 16.

During the Apollo 16 space flight, in the experiment system M-191, (microbial response to space environment) spores of Bacillus subtilis 168 were exposed to space vacuum or solar UV irradiation with a peak wavelength of 254 nm or both. The effects of these space factors on the colony-forming ability of the spores were studied. It was found (i) that space vacuum alone did not affect the survival of pre-dried spores; (ii) that space vacuum in combination with solar UV irradiation with a peak wavelength of 254 nm had a synergistic effect, which may by attributed to a UV supersensitivity of the spores during vacuum exposure. These results agreed with findings of simulation experiments on earth. It was concluded that air dried spores may survive exposure to space vacuum if shielded against solar UV irradiation.

The Biostack experiment on Apollo 16.

The object of the Biostack experiment is to study the biological effects of high ZE particles of cosmic radiation in order to obtain information on the mechanism of these particles in biological matter. For this purpose individual local evaluation methods have been developed which allow one to identify each biologically effective particle and to correlate the individual hitting particle with the biological effect produced. The Biostack experimental package contains a series of monolayers of selected biological objects (Bacillus subtilis spores, Arabidopsis thaliana seeds, Vicia faba radiculae, Artemia salina eggs) with each layer sandwiched between several different cosmic ion track detectors (nuclear emulsions, cellulose nitrate, polycarbonate). By this arrangement a variety of biological effects due to a single penetrating particle can be analysed. Influence on cellular and tissue development, nuclear damages, and mutation induction are the main investigated effects. These space flight findings will be completed by results of balloon flight and accelerator experiments.

Effects of simulated space vacuum on bacterial cells.

The effect of vacuum on bacterial cells is related to water desorption. Below water vapour pressure the inactivation remains constant, independent of total pressure and exposure time. In subsequent growth, the lag-phase of the survivors is delayed. Combined treatment with vacuum and radiation (X-rays or uv of 254 nm wavelength) results in synergistic effects, whereas vacuum and heat can act antagonistically. The vacuum inactivated cells (indicated as loss of colony-forming ability) are completely damaged. They do not show cellular elongation, phage production or respiration. The cellular membrane becomes permeable by vacuum exposure: biomolecules are released from the cells when re-suspended after vacuum treatment.

Survival of bacterial spores under some simulated lunar surface conditions.

Spores of Bacillus subtilis were exposed to simulated lunar environmental factors, in order to estimate the chance of living matter to survive on the moon. Vacuum, radiation and extreme temperature were selected and their individual and combined influence was tested. High vacuum up to 2 x 10(-7) torr and ultra-high vacuum up to 5 x 10(-9) torr, ultraviolet rays (254 nm) and a temperature of 80 degrees C were used. The results were compared with those of experiments on vegetative cells.