Autoimmune CD4+ T cell memory: lifelong persistence of encephalitogenic T cell clones in healthy immune repertoires

We embedded green fluorescent CD4(+) T cells specific for myelin basic protein (MBP) (T(MBP-GFP) cells) in the immune system of syngeneic neonatal rats. These cells persisted in the animals for the entire observation period spanning >2 years without affecting the health of the hosts. They maintained a memory phenotype with low levels of L-selectin and CD45RC, but high CD44. Although persisting in low numbers (0.01-0.1% of lymph node cells) they were sufficient to raise susceptibility toward clinical autoimmune disease. Immunization with MBP in IFA induced CNS inflammation and overt clinical disease in animals carrying neonatally transferred T(MBP-GFP) cells, but not in controls. The onset of the clinical disease coincided with mass infiltration of T(MBP-GFP) cells into the CNS. In the periphery, following the amplification phase a rapid contraction of the T cell population was observed. However, elevated numbers of fully reactive T(MBP-GFP) cells remained in the peripheral immune system after acute experimental autoimmune encephalomyelitis mediating reimmunization-induced disease relapses.     

Mass outbreak of food poisoning disease caused by small amounts of staphylococcal enterotoxins A and H

It was believed that food poisoning in Osaka in 2000 was due to small amounts of staphylococcal enterotoxin A (SEA) in reconstituted milk. Results of this study clearly indicate that SEH was also present in the raw material of reconstituted milk, indicating that the food poisoning was caused by multiple staphylococcal enterotoxins.     

Zinc homeostasis in the hippocampus of zinc-deficient young adult rats

On the basis of the evidence of the transient learning impairment of young adult rats fed a zinc-deficient diet for 4 weeks, zinc concentration in the hippocampus was examined in the zinc-deficient rats to understand the mechanism of brain dysfunction in zinc deficiency. Zinc concentration in the hippocampus, as well as that in other brain regions, was not decreased by 4-week zinc deprivation. When Timm's stain, with which histochemically reactive zinc in the presynaptic vesicles is detected, was compared between the control and zinc-deficient rats, the intensity of Timm's stain in the hippocampus was almost the same between them. In the hippocampus, zinc concentration in the synaptosomal fraction was not also decreased by 4-week zinc deprivation, whereas that in the crude nuclear fraction was significantly increased. These results suggest that zinc concentration in the presynaptic vesicles is not decreased in young adults rats by 4-week zinc deprivation. It is likely that zinc-requiring systems in the nucleus are more responsive to zinc deficiency than vesicular zinc. This responsiveness appears to be involved in the transient learning impairment.     

Aged garlic extract enhances production of nitric oxide

Nitric oxide (NO) controls several physiological functions of the cardiovascular system. Three kinds of NO synthases (NOSs), neuronal constitutive NOS (ncNOS), inducible NOS (iNOS) and endothelial constitutive NOS (ecNOS), were responsible for NO biosynthesis. This study investigated the effect of aged garlic extract (AGE) on NO production by measuring the NO metabolites nitrite and nitrate in the plasma of mice. AGE (2.86 g/kg, p.o.) temporarily increased NO production by 30-40% from 15 to 60 min after administration. The time course of the fluctuation in NO levels in the AGE-treated group was clearly different to that in a group of mice treated with lipopolysaccharides, a typical iNOS inducer. Arginine (63 mg/kg, p.o.) at the equivalent dose of AGE did not increase NO production. However diphenyleneiodonium chloride (1 mg/kg, i.p.), a selective cNOS inhibitor, administered prior to AGE, overcame the effect of AGE. These results indicate that AGE increased NO production by activating cNOS, but not iNOS. The arginine contained in AGE was not responsible for the effect. AGE may be a useful tool for the prevention of cardiovascular disease.     

Bioremediation of Fish Cannery Wastewater with Yeasts Isolated from a Drainage Canal

Several yeasts were isolated from a drainage canal in a Japanese fish food processing factory. They were characterized by the decomposition of organic polymers such as proteins and reducing sugars, their growth in the wastewater, the decrease in total organic carbon (TOC), and taxonomy. Three strains of yeast dominated the sample: Debaryomyces occidentalis (P1), Trichosporon ovoides (P19), and a strain that could not be identified (S27). Strain P19 had the highest TOC-decreasing activity and was immobilized onto chitosan beads. The immobilized yeasts reduced the TOC from 1.2 × 103 to 3.0 × 102 mg of C/L per day in the fish cannery wastewater.     

Simulations of airflow and substance concentration around a human body

In order to predict airflow and suspended substance concentration around a human body, we developed a geometric model of the human form and generated grids around it for Computational Fluid Dynamics (CFD). According to a CFSV model proposed by us we made a domain that included a geometric human model and generated the grids within this domain. By using this model with the grids and the developed CFD program, it is possible to simulate the airflow and the transfer of a suspended substance around the body. The simulated airflow provided a different velocity profile for each region of the body due to the characteristics of the body shape. The simulated distribution of the suspended substance concentration demonstrates how usable the present model is for quantifying a substance in any exposed region of the body.     

Fusicoccins P and Q,and 3-epifusicoccins H and Q,new polar fusicoccins from isolate Niigata 2-A of a peach Fusicoccum canker fungus

Our search for new polar fusicoccins biosynthetically related to fusicoccin A from the culture filtrate of isolate Niigata 2-A of a peach Fusicoccum canker fungus resulted in the isolation of new fusicoccins named fusicoccins P and Q, and 3-epifusicoccins H and Q, together with 3'-deacetylfusicoccin A and 16-O-demethyl-3-epifusicoccin J. The structures of fusicoccins P and Q, and of 3-epifusicoccin Q were determined to be those of deisopentenylfusicoccin J, 12alpha-hydroxyfusicoccin H and 12alpha-hydroxy-3-epifusicoccin H, respectively, by NMR spectrometry and chemical derivation from known fusicoccins. 3-Epifusicoccin H was identified by comparing its 400 MHz NMR spectra with those of fusicoccin H. The lettuce seed germination-stimulating activity of these new fusicoccins was examined in the presence of ABA: fusicoccin P was highly active, while 3-epifusicoccins H and Q were slightly active, and fusicoccins H and Q were almost inactive. Possible biosynthetic pathways incorporating these new fusicoccins and 3-epifusicoccins from geranylgeranyl diphosphate to 3'-deacetlyfusicoccin A and 16-O-demethyl-3-epifusicoccin J are discussed.