Teratogenic effects of excess glucose on head-fold rat embryos in culture.

Rat embryos explanted at nine and one-half days of gestation (early head-fold stages) were cultured for 48 hours in rotating bottles containing rat serum and a gas phase. Addition of 12-15 mg/ml of D-glucose to the culture medium resulted in severe abnormalities and retarded development in a high proportion of embryos, whether or not the osmolarity increase brought about by the addition of glucose was corrected. The raised osmolarity, however, increased the frequency and severity of malformations observed. L-glucose produced no abnormalities, though embryonic development was retarded.     

Characterization of strains of Leuconostoc mesenteroides by analysis of soluble whole-cell protein pattern, DNA fingerprinting and restriction of ribosomal DNA

Of 215 leuconostocs isolated from field grass, natural whey cultures and water-buffalo milk, 178 were identified as Leuconostoc mesenteroides ssp. mesenteroides while 37 strains could not be identified Biochemical characterization allowed seven groups to be defined. Representative strains of each group and different habitat and nine reference strains were selected for further analyses. Protein profiles appeared suitable for species discrimination, but did not differentiate between the three subspecies of Leuc. mesenteroides. The technique also showed some differences among equivocal strains. DNA fingerprinting for most strains of Leuc. mesenteroides ssp. mesenteroides examined showed a different restriction pattern from that of the type strain. Ribotyping was not useful for discriminating species and subspecies of the genus Leuconostoc: Leuc. mesenteroides ssp. mesenteroides and ssp. dextranicum showed the same ribopattern as Leuc. lactis while Leuc. mesenteroides ssp. cremoris exhibited a pattern distinct from all the other species examined. On the basis of ARDRA-PCR, two main groups could be distinguished: the larger group included Leuc. mesenteroides, Leuc. lactis, Leuc. pseudomesenteroides and some unidentifiable strains; the second one included Leuc. citreum, Leuc. fallax, Weissella paramesenteroides and some unidentified strains.     

Influence of neutron collimation on the energy deposition in a tissue equivalent sphere

Summary The influence of neutron collimation on the shape of energy deposition spectra was investigated using a spherical walled proportional counter. Experimental dose averaged lineal energies were obtained and compared with theoretical values. The fractions of total absorbed dose corresponding to various intervals of lineal energies were also deduced from the measured distributions.Contribution No. 1289 of the Biology Programme, Directorate General XII of the Commission of the European Communities