Sumie Shinjo

Effect of Dietary Vitamin E Supplementation on Murine Nasal Allergy

BACKGROUND Although many studies have reported the effects of dietary vitamin E on the immune response, none so far has assessed its role in nasal allergy. METHODS Female BALB/c mice were randomized into two groups and fed a 20% casein diet (control group, 50 mg vitamin E/kg diet) or this diet supplemented with 535 mg vitamin E/kg diet (vitamin E group, 585 mg vitamin E/kg diet) for 4 weeks. During the fifth week, the mice in each group were divided into two subgroups to form a total of four treatment groups: group A (control), group B [control + toluene diisocyanate (TDI) sensitization], group C (vitamin E supplementation), and group D (vitamin E supplementation + TDI sensitization). Groups B and D were treated with two courses of intranasal application of 5% TDI in ethyl acetate, whereas groups A and C were treated with ethyl acetate alone. A week after second sensitization all groups were provoked by applying 2.5% of TDI in the vehicle and nasal allergic responses were observed for 10 minutes. Splenic lymphoproliferation, splenic cell cytokines, and the total serum IgE were measured. RESULTS Members of group D had lower (P < 0.01) scores of nasal response and sneezed less frequently (P < 0.01) than those of group B. Similarly, splenic lymphoproliferation and production of IL-4 and IL-5 as well as the total serum IgE levels were lower (P < 0.01) in group D than in group B. CONCLUSIONS The results indicate that higher doses of vitamin E supplementation may suppress nasal allergic responses.

The Effects of Oral RNA and Intraperitoneal Nucleoside-Nucleotide Administration on Methicillin-Resistant Staphylococcus aureus Infection in Mice

The effects of oral RNA and intraperitoneal nucleoside-nucleotide mixture administration on methicillin-resistant Staphylococcus aureus (MRSA) strain 8985N infection were studied in mice. BALB/c mice were fed a nucleic acid-free diet or nucleic acid-free diet supplemented with 0.5% or 2.5% ribonucleic acid (RNA) for 30 days. Nucleoside-nucleotide mixture or saline (control) was intraperitoneally administered daily to these rats except for the 2.5% RNA group, which received saline only. On the 10th day of this treatment, the mice were inoculated intravenously with the viable MRSA organisms. Susceptibility to the MRSA was determined by animal survival and recovery of the MRSA from the organs. The survival rates in the three groups that were administered saline were 29%, 35%, and 40% for nucleic acid-free diet, 0.5% RNA, and 2.5% RNA groups, respectively, whereas in the two groups that received the nucleoside-nucleotide mixture the rates were 69% for the nucleic acid-free diet group and 55% for 0.5% RNA group. The susceptibility of the mice to the MRSA challenge was not affected by dietary RNA, which indicates the ineffectiveness of oral RNA. The combined survival rate in the two nucleoside-nucleotide groups (64%) was statistically different (p < .01) from that in the three saline groups (34%). There was a greater reduction in viable organism recovery in the kidney and spleen of the surviving mice that had been administered the nucleoside-nucleotide mixture than in those administered saline.(ABSTRACT TRUNCATED AT 250 WORDS)

Favorable effects of egg white protein on lipid metabolism in rats and mice

Abstract Egg is a cholesterol-rich food and has a strong hyper-cholesterolemic action. However, all the cholesterol is in egg yolk and egg white is cholesterol-free. The effect of egg white protein and its hydrolysates on the serum lipids were compared with casein and soybean protein in rats and mice. The animals were given 30% casein diet (Ca group) or diets of 15% casein plus 15% soybean protein isolate (SPI group), egg white protein (EW group) or egg white protein hydrolysates (EW-P group) for 3 (rats) or 2 (mice) weeks. Food intake and growth were very similar among the different dietary groups. Hypocholesterolemic effect was observed in SP, EW and EW-P groups in rats and EW group in mice. Prevention of the reduction of HDL-cholesterol was found in EW and EW-P groups in rats and EW-P group in mice. The result suggests the possibility of the use of egg white for the prevention and treatment of hyper-cholesteremia.

Influence of time lag in amino acid absorption on nitrogen retention in rats

Abstract Depending on the form of nitrogen sources, there is a time lag in amino acid absorption. However, the influence of such a time lag on nitrogen retention is not known. In the present experiment we created a time lag in amino acid absorption and observed nitrogen retention in rats. Two unbalanced amino acid mixtures were prepared. The equal amount of combination of these mixtures makes the amino acid pattern of egg protein. Rats were given these two unbalanced amino acid mixture diets alternatively at 08:00–09:30 hr, 11:00–12:30 hr, 14:00–15:30 hr, and 17:00–18:30 hr for 14 days. Control rats were given egg-protein-pattern amino acid mixture diet at the same time and periods as the experimental group. Dietary amino acid levels were 5% and 10%. Although the control and experimental rats ate similar amounts of each amino acid, there was a time lag in the amino acid absorption. Plasma aminograms, hematologic values, body protein concentration, and growth were very similar. The results indicate that nitrogen utilization is not influenced by a relatively small time lag in amino acid absorption.