ALBERT

Notes: Abstract Double differential cross sections (angular distributions and energy loss spectra) have been measured of electrons after ionizing electron collisions with helium at primary energiesE 0 between 25 eV and about 260 eV and with argon atE 0=75, 150 and 200 eV. The spectra have been measured with an energy analyzing collector system of constant transmission. It was found that for high collision energies (E 0≧ 80 eV) the outgoing electrons belong to one of the two energetically well separated groups, either thefast electrons, which are scattered mainly in forward direction or theslow electrons which are distributed isotropically into all angles. At low primary energiesE 0 no separation into groups is possible. Several findings indicate the qualitative applicability of the binary collision model.

Notes: Zusammenfassung Vor dem Hintergrund der vielfältigen Endotoxoidwirkung wurde diese Substanz in chronischen Toxizitätsstudien beiMacaca mulatta geprüft. Endotoxoid wurdeMacaca mulatta in einer Dosierung von jeweils 100γ/kg in insgesamt 51 Injektionen innerhalb von 12 Wochen injiziert. Dabei zeigte sich, dass diese Substanz keinen Einfluss auf die geprüften klinischchemischen Parameter hatte und bei makroskopischer und histologischer Untersuchung keine Veränderungen auftraten.

Notes: BOOK REVIEWS

Notes: Summary 1. Eggs of the bean weevilBruchidius obtectus were irradiated regionally with UV-light of 270–330 nm wave length. The irradiated area extends transversally across the egg and covers 10 or 20% of the egg's length. Irradiation was done either from a single side (“QB”) or from 4 sides each after a 90°-rotation of the egg (“RB”): the latter treatment affects the egg more strongly. The 3 different irradiation periods used, one, two or three minutes, produced similar results. Of the incident irradiation energy, 75–85% is absorbed by the egg's envelope. 2. UV-irradiation before preblastoderm formation does not visibly injure any egg component. Normal embryos develop as a rule even after UV-irradiation of the whole ventral face of the egg. There is, however, a considerable retardation of development which indicates primary or secondary influences of the irradiation procedure on developmental reactions of the ooplasmic system. 3. Irradiation after preblastoderm formation is followed by visible damage early in development. The effects, accumulation of ectoplasm and pycnosis of nuclei, decrease from the center towards the margins of the irradiated area; the underlying yolk-entoplasm appears unaffected. Early damage produced by irradiation of preblastoderm eggs leads to defects in the germ band only if the irradiated area includes at least partially a “critical region for definable segment defects” (“KBS”) between 35 and 65% of the egg's length. Damage in front of or behind this critical region can be regulated. 4. Early damage observed after irradiation of blastoderm, however, is always, and irrespective of its location, followed by formation of a disturbed metameric pattern. It is concluded that between preblastoderm and blastoderm stages the functional condition of the superficial egg materials must have changed towards the egg poles so that the capacity to regulate is lost. 5. Late defects may become manifest in any region of the embryonic body. They may in accordance with the longitudinal extent of the irradiated area involve one or several body segments. QB-irradiation affects one lateral half of each segment involved, RB-irradiation eliminates both halves. Irradiation of a whole lateral Vorkeimanlage is followed by formation of a half-embryo from the remaining lateral Vorkeimanlage. 6. Segmental defects produced by irradiation of preblastoderm or blastoderm stages correlate with the same positions of irradiated area for any particular segment. To affect the same segment by irradiation of the Vorkeimanlage, a more posterior area of irradiation is required. 7. The “critical zone for bipartite development” (“KBB”) revealed by earlier ligation experiments of blastoderm eggs is congruent in position and extent with the “critical region for definable segment defects” from UV-irradiation (see 3). In contrast to ligation experiments, the loss of germ band segments after early irradiation is not more extensive than after late irradiation. From this and from the formation of complete segment patterns by UV irradiated eggs it is concluded that the bipolar reaction system revealed by ligation experiments cannot be confined to the superficial egg regions affected by UV. 8. It is pointed out that in order to be able to compare different insect egg types these have to be studied by identical methods.

Notes: Summary Spherical lipid bimolecular membranes of a large surface area separating two aqueous solutions were formed from the total lipid extracts of human red cell ghosts and from their individual lipid components. The isotopic permeabilities of these membranes to biologically important sugars and to a related polyol were measured. The observedd-glucose permeabilities of the bimolecular membranes of the total lipid, phosphatidyl choline, phosphatidyl ethanolamine, sphingomyelin, and cholesterol were 2.35, 2.51, 2.23, 1.35, and 0.62×10−10 cm/sec, respectively. These permeabilities are about four to five orders of magnitude lower than that of the intact red cell membrane. The permeabilities of the bimolecular membrane made from an identical extract of the total lipid to different sugars varied: the values ford-glucose,d-mannose,d-ribose,d-fructose, 2-deoxy-d-glucose, 3-0-methyl-d-glucose, andd-mannitol were 2.3, 2.6, 8.9, 0.38, 16.1, 11.2, and 0.44×10−10 cm/sec, respectively. The pattern of the difference is neither parallel with nor as extensive as that observed with the intact red cell membrane. The observed permeabilities of the lipid membranes, however, agree qualitatively with what is predicted by an analysis of non-specific movements of nonelectrolytes across the cell membranes. The failure of the membrane lipids to reproduce the carrier function in a structure most closely approximating that of living membranes strongly suggests that some membrane components other than lipids are required for this function.