Synthesis of 2,6-anhydro-S-[ethylmercury(II)]-1-thio-D-glycero-L-manno-heptitol+ ++ and bis(2,6-anhydro-1-thio-D-glycero-L-manno-heptitol)mercury(II), and the study of their interaction with beta-D-galactosidase from E. coli

Two competitive inhibitors of beta-D-galactosidase activity, namely, 2,6-anhydro-S-[ethylmercury(II)]-1-thio-D-glycero-L-manno-heptitol (4) and bis(2,6-anhydro-1-thio-D-glycero-L-manno-heptitol)mercury(II) (6), with inhibition constants of 8.0 X 10(-4) M and 1.9 X 10(-4) M, were synthesized. Compound 6 was incorporated into the crystalline enzyme by cocrystallization. The stoichiometry of the enzyme-inhibitor complex was 1:4, corresponding to one molecule of inhibitor per active site of the enzyme. Compound 4 was found to be unstable against X-ray irradiation, whereas compound 6 was submitted to X-rays for several days without any radiation damage.

Changes in the migratory activity of polymorphonuclear leukocytes after administration of Freund's adjuvant

Spontaneous and chemotactic activity of polymorphonuclear leukocytes, obtained from the peritoneal cavity, was studied after administration of complete and incomplete Freund's adjuvant to rabbits at intervals of 18-26 d after adjuvant injection. Whereas injection of both complete and incomplete adjuvant increased spontaneous migration of rabbit polymorphonuclear leukocytes, the migration directed by the chemotactic signal, induced in fresh serum by E. coli endotoxin, was decreased. The chemotaxigenic activity of two factors, isolated from cell walls of Listeria monocytogenes was also tested: factor Ei (its most potent component is lipopolysaccharide) and a purified phenol extract of lipopeptidopolysaccharide nature.

At least three sequential steps are involved in the tetanus toxin-induced block of neuromuscular transmission

Tetanus toxin causes a block of the neuromuscular transmission. The kinetic aspects of the block were studied in vitro on the mouse phrenic nerve-hemidiaphragm exposed to toxin (1 microgram/ml). 1. The toxin action on the nerve ending involves three sequential steps: binding, "translocation" and paralysis. 2. Diffusion and binding of tetanus toxin molecules to the presynaptic membrane is complete in about 60 min. The binding step is irreversible, independent of transmitter release and of the temperature. Tetanus antitoxin, however, inactivates the bound toxin molecules. 3. After a second step which is probably due to a "translocation" of the toxin molecules into or through the presynaptic membrane the antitoxin molecules are now ineffective to prevent the toxin-induced inhibition of transmitter release. This so called "translocation" step requires transmitter release and therefore depends strongly on the frequency of nerve stimulation. 4. The paralytic step does not depend on the transmitter release. It, however, depends strongly on temperature with a break in the Arrhenius-plot around 33 degrees C which suggests the involvement of a phase transition rather than of an enzymatic activity of the toxin.

Resistance to Mycobacterium tuberculosis H37Rv infection induced by Listeria and mycobacterial lipids

The avirulent strain Listeria monocytogenes (Welshimer) induced upon a single injection 4 weeks prior to challenge with Mycobacterium tuberculosis H37Rv resistance in guinea-pigs, which was manifested by a significant decrease of spleen weight and Feldman's index in immunized animals. The degree of resistance was dependent on the immunizing dose and time of administration. Repeated high doses of Listeria yielded only a low or no effect. Further increase of resistance was obtained using the BCG lipids; however, stimulation of resistance with listeria lipids was not successful and, finally, Freund's incomplete adjuvant was significantly effective in the Feldman index only. The BCG lipids, extracted with ethanol, which contained nitrogen and water-soluble substances, induced a significant resistance against M. tuberculosis infection. The chloroform-methanol BCG lipids were also effective, however, significantly less than the ethanol-extracted material. The listeria factor Ei itself or together with Freund's incomplete adjuvant possessed only low effectiveness against mycobacterial infection. However, if injected together with ethanol-extracted BCG lipids, it produced a significant degree of resistance which was higher than that induced by lipids only. The degree of resistance was comparable with the effect of living BCG strain which served as a source of isolated lipids.

The reported film storage problem solved? 100 MM FILM MINIATURISATION USING THE Oldelft, Delcopex and Odelcard system

The case for film miniaturisation is argued. This system as practised at Kettering General is described. Some possible future applications of the system are discussed. I hope I may have stimulated some thought, or even argument as to our future in these directions.

A fertility reaction to a historical event: southern white birthrates and the 1954 desegregation ruling

On 17 May 1954 the Supreme Court, in its decision in Brown v. Board of Education, declared de jure segregation of the public schools to be unconstitutional. It is argued here that a consequence of that decision was a decline in childbearing among white Southerners. In the nation as a whole, period fertility rates increased between 1954 and 1955, but in 9 of the 11 former Confederate states they decreased. Further analysis shows that these Southern fertility decreases began about 12 months after the Supreme Court decision. This variation in behavior in reaction to a historical event has important implications for the explanation and prediction of fertility.