Hemagglutinating and binding properties of botulinum C2 toxin

To characterize the binding substance(s) for botulinum C2 toxin, the hemagglutinating activity of component II of botulinum C2 toxin (C2II) was studied by hemagglutination and hemagglutination inhibition. Human and animal erythrocytes were agglutinated by trypsinized C2II much more strongly than by untreated C2II. Trypsinized C2II agglutinated neuraminidase-treated erythrocytes more strongly than intact, trypsin- and pronase-treated ones. On the other hand, trypsin- and pronase-treated erythrocytes were more weakly hemolyzed by trypsinized C2II than intact and neuraminidase-treated ones, and trypsinized C2II showed both hemagglutinating and hemolytic activities to these erythrocytes. Hemagglutination of trypsin-treated human type B erythrocytes was inhibited by galactose, N-acetylgalactosamine, N-acetylglucosamine, L-fucose and mannose. Thyroglobulin and bovine salivary mucin were much stronger inhibitors. From these findings, the binding substance(s) for botulinum C2 toxin on erythrocytes is(are) suggested to be glycoprotein(s).     

The Promoter of the Gene for Plastidic Glutamine Synthetase (GS2) fromRice Is Developmentally Regulated and Exhibits Substrate-Induced Expression in Transgenic Tobacco Plants

A 1.3-kb fragment from the 5'-flanking region of the RGS-38gene, which encodes the plastidic glutamine synthetase in Oryzasativa L., was fused to a ß-glucuronidase (GUS) reportergene and introduced into Nicotiana tabacum by Agrobacterium-mediatedtransformation. The promoter directed GUS expression, both inleaves and in roots, and the expression of GUS was regulatedby light. The GUS activity was high in the mature leaves ofthe transgenic tobacco plants, in marked contrast to the activityof the GS1 promoter. The GS2 promoter also responded to externallyapplied ammonia, as is the case for the GS1 promoter. Theseresults suggest that the cis-acting regulatory elements thatcontrol the response to ammonia, a substrate for glutamine synthetase,are located within a 1.3-kb region of the promoter. (Received October 1, 1991; Accepted January 20, 1992)     

Genetic analysis of type E botulinum toxin-producing Clostridium butyricum strains

Type E botulinum toxin (BoNT/E)-producing Clostridium butyricum strains isolated from botulism cases or soil specimens in Italy and China were analyzed by using nucleotide sequencing of the bont/E gene, random amplified polymorphic DNA (RAPD) assay, pulsed-field gel electrophoresis (PFGE), and Southern blot hybridization for the bont/E gene. Nucleotide sequences of the bont/E genes of 11 Chinese isolates and of the Italian strain BL 6340 were determined. The nucleotide sequences of the bont/E genes of 11 C. butyricum isolates from China were identical. The deduced amino acid sequence of BoNT/E from the Chinese isolates showed 95.0 and 96.9% identity with those of BoNT/E from C. butyricum BL 6340 and Clostridium botulinum type E, respectively. The BoNT/E-producing C. butyricum strains were divided into the following three clusters based on the results of RAPD assay, PFGE profiles of genomic DNA digested with SmaI or XhoI, and Southern blot hybridization: strains associated with infant botulism in Italy, strains associated with food-borne botulism in China, and isolates from soil specimens of the Weishan lake area in China. A DNA probe for the bont/E gene hybridized with the nondigested chromosomal DNA of all toxigenic strains tested, indicating chromosomal localization of the bont/E gene in C. butyricum. The present results suggest that BoNT/E-producing C. butyricum is clonally distributed over a vast area.     

Relationship between sex-role identity and functional cerebral lateralization

The present study examined the relationship between sex-role identity (SRI) and functional cerebral lateralization (FCL) in right-handed males. Two tasks (figure task and location task) were used to assess FCL. The figure task required the identification of shape stimuli, while the location task involved identification of the position of stimuli. SRI was assessed by the Bem Sex Role Inventory (BSRI). Males with higher masculine scores in the BSRI indicated greater differences in the reaction time between right and left visual-fields in the location task. This finding suggests that males with higher masculinity in SRI might have greater FCL.     

Effects of dietary polyamine deficiency on Trypanosoma gambiense infection in rats

Nishimura, K., Araki, N., Ohnishi, Y., and Kozaki, S. 2001. Effects of dietary polyamine deficiency on Trypanosoma gambiense infection in rats. Experimental Parasitology 97, 95-101. A diet deficient in polyamines decreases the availability of dietary polyamines. We used rats infected with the Wellcome strain of Trypanosoma gambiense to examine the effects of polyamine-deficient chow (PDC) on trypanosome proliferation and symptoms of infection. Rats fed PDC showed limited increase of trypanosome and symptoms of infection and limited loss of body weight and anemia. Survival in these rats was prolonged. Before infection, the heparinized plasma concentration of spermidine in the PDC-fed rats was lower than that in control rats fed with standard chow. After infection, the content of spermidine in red blood cells increased in the control rats, but was only slightly increased in PDC-fed rats. The content of spermidine in the trypanosomes after infection was low in the PDC-fed rats. Decreases in the polyamine content of trypanosomes limited their increase. These observations suggest that a reduction in dietary polyamines may help in the regulation of trypanosome infection.