Adenovirus-mediated peroxisome proliferator activated receptor gamma overexpression prevents nutritional fibrotic steatohepatitis in mice.

OBJECTIVE: The pathogenesis of non-alcoholic steatohepatitis is still unclear. We have demonstrated previously that peroxisome proliferator activated receptor gamma (PPARγ) ligand protects against inflammation and fibrogenesis in experimental non-alcoholic steatohepatitis. We aim to elucidate the effect and the mechanism of PPARγ itself on nutritional fibrotic steatohepatitis in mice. METHODS: C57BL/6J mice were fed with methionine-choline deficient (MCD) diet for 8 weeks to induce fibrotic steatohepatitis. Mice fed the MCD diet were treated with adenovirus carrying PPARγ (Ad-PPARγ), Ad-PPARγ plus PPARγ agonist rosiglitazone, or PPARγ antagonist 2-chloro-5-nitrobenzaniliden (GW9662), respectively. The effects of up-regulation of PPARγ in the presence or absence of its agonist/or antagonist were assessed by comparing the severity of hepatic injury, activation of hepatic stellate cells and the expression of adiponectin, heme oxygenase-1, and fibrogenic related genes. RESULTS: Mice fed with MCD diet for 8 weeks showed severe hepatic injury including hepatic steatosis, inflammatory infiltration, and fibrosis. Administration of Ad-PPARγ significantly lowered serum alanine aminotransferase level and ameliorated hepatic steatosis, necroinflammation, and fibrosis. These effects were associated with enhanced expression of PPARγ, up-regulated expression of adiponectin and heme oxygenase-1, and down-regulated expression of tumor necrosis factor alpha, interleukin-6, α-smooth muscle actin, transforming growth factor beta 1, matrix metallopeptidase-2, and -9. Administration of GW9662 promoted the severity of liver histology. CONCLUSIONS: The present study provided evidences for the protective role of overexpressing PPARγ in ameliorating hepatic fibrosing steatohepatitis in mice. Modulation of PPARγ expression might serve as a therapeutic approach for fibrotic steatohepatitis.

The consumer cost of calcium from food and supplements.

Nutritional authorities encourage consumers to include calcium-rich foods in their daily diets. However, consumer purchases are driven not only by health considerations and dietary preferences, but also by cost. This study assessed the cost of calcium from a wide variety of food sources, as well as supplements, based on retail prices in Seattle, San Francisco, Raleigh, NewYork City, and Washington, D.C., while controlling for seasonal variation. Costs were adjusted based on calcium absorption fractions. Calcium carbonate supplements emerged as the least expensive source of calcium, at roughly one-third the cost of the least expensive food source of calcium. The least expensive food sources of calcium were Total cereal, skim milk, and calcium-fortified orange juice from frozen concentrate. This information is useful for dietitians, health professionals, and consumers in meeting calcium requirements on a budget.

Induction of specific immune responses by polycation-based vaccines.

The s.c injection of tumor Ag-derived, MHC class I-binding peptides together with cationic poly-amino acids (e.g., poly-L-arginine; pR) has been shown to protect animals against a challenge with tumor cells expressing the respective peptide(s). Given our only restricted knowledge about immunogenic tumor-associated peptides, we sought to determine whether this pR-based vaccination protocol would also induce protective cancer immunity if large proteins were used instead of peptide epitopes. We found that the intracutaneous administration of the model Ag beta-galactosidase (beta-gal) together with pR (referred to as pR-based protein vaccine; pR-PV) was significantly more potent in protecting mice against the growth of beta-gal-expressing RENCA cells than the protein alone. Coadministration of pR enhanced both the beta-gal-induced specific humoral and CD8 response. The protective effect required CD8(+), but neither CD4(+) T lymphocytes nor beta-gal-specific Abs. beta-Gal priming of protective CD8(+) T lymphocytes was found to be CD4(+) T cell-independent, to take place within the draining lymph nodes, and to be accomplished by day 5 after vaccination. Ablation of the injection sites as early as 1.5 h after pR-PV administration still led to protection in a large proportion of the animals, indicating that certain protein Ags administered intradermally in the context of polycations are quickly transported to the draining nodes, where they induce molecular and cellular events resulting in the helper-independent priming and expansion of Tc1 cells. However, optimal protection required the prolonged presence of the injection site, suggesting that pR-PV injection facilitates the formation of a cutaneous depot of Ag-charged cells capable of migration and T cell activation.

Nutritional supplements used in weight-reduction programs increase intestinal gas in persons who malabsorb lactose.

OBJECTIVE: To determine if ingestion of 2 doses of milk-based dietary supplements produce gaseous symptoms in subjects who malabsorb lactose. DESIGN: Randomized, controlled, crossover trial. SUBJECTS/SETTING: Ten community-based subjects who malabsorb lactose. INTERVENTION: Ingestion of 2 standard servings of milk-based supplements (a powder reconstituted in fat-free milk or a ready-to-drink preparation) or low-lactose control preparations. MAIN OUTCOME MEASURES: Frequency of flatus passage and subjective impression of bloating, flatulence, and abdominal discomfort. STATISTICAL ANALYSIS: Wilcoxon signed-rank test. RESULTS: The high lactose content (27 g) of 2 servings of the powder-based supplement ingested without other food resulted in a marked increase in daily flatus passages from the basal level of 9.7+/-8.2 to 30+/-14 (mean+/-SD), and a significant increase in the subjects' perception of gas. In contrast, the lower lactose content (18.4 g) of 2 servings of a ready-to-drink supplement resulted in a flatus frequency of 17+/-10 (P=.14 vs baseline) and no significant increase in the perception of increased gas. Neither supplement resulted in a significant increase in bloating, abdominal pain, or diarrhea. The lactose content of the liquid supplement was reduced by 80% following overnight incubation with an over-the-counter lactase preparation. APPLICATIONS/CONCLUSIONS: Persons who malabsorb lactose should be aware that sizable increases in rectal gas commonly occur when milk-based powders reconstituted in milk are used as meal replacements. In contrast, gas problems probably will be minor following ingestion of 2 doses of a ready-to-drink, milk-based supplement. The lactose content of these supplements can be markedly reduced by overnight incubation with over-the-counter lactase preparations, and this manipulation should be beneficial for subjects troubled by the increased gas caused by the consumption of lactose-containing supplements.

Strain-dependent antibody response induced by DNA immunization.

The antibody (Ab) response induced by DNA-based immunization was compared in various strains of inbred, H-2 congenic and outbred mice with different haplotypes of mouse major histocompatibility complex (H-2). Two different plasmid expression vectors encoding Aequorea victoria green fluorescent protein (GFP) or Escherichia coli, beta-galactosidase (beta-gal) were introduced into quadriceps muscle, and Ab production was examined using both enzyme-linked immunosorbent assay and immunoblot analysis. The beta-gal plasmid DNA immunization induced strong Ab production in all inbred, H-2 congenic and outbred strains at the early stages of immunization. By comparison with beta-gal peptide immunization, the degree of Ab response was H-2 haplotype-dependent. On the other hand, Ab production by GFP plasmid DNA immunization was observed in outbred strains, but not in some of the inbred and H-2 congenic strains. Also, outbred strains showed a high Ab response compared with other inbred and H-2 congenic strains by GFP peptide immunization. Reverse transcription-polymerase chain reaction analysis demonstrated the presence of GFP or beta-gal transcripts at the DNA inoculation site in all the strains studied, even in inbred and H-2 congenic strains which showed no Ab production by GFP plasmid DNA immunization. These results indicate that the difference in Ab response induced by DNA immunization as well as by peptide immunization depends upon the H-2 haplotypes of host strains.

Enzyme replacement with liposomes containing beta-galactosidase from Charonia lumpas in murine globoid cell leukodystrophy (twitcher).

Enzyme replacement with liposomes containing beta-galactosidase obtained from charonia lumpas was carried out in murine globoid cell leukodystrophy (GLD). Charonia lumpas beta-galactosidase was able to hydrolyze galactocerebroside trapped into liposomes prepared from lecithin, cholesterol and sulfatide (molar ratio; 7:2:1). Liposomes containing charonia lumpas beta-galactosidase were successfully incorporated into the mouse tissues. 3H-galactocerebroside labeled liposomes were also incorporated into mouse liver, spleen and other tissues. The accumulation rate of 3H-galactocerebroside into twithcer mice liver and spleen was almost 40 to 100 times higher than those of controls and degraded to 70 to 80% of accumulated radioactivity of 3H-galactocerebroside by single injection of liposomes containing charonia lumpas beta-galactosidase. Results suggest that exogeneous enzyme trapped in liposomes can be useful for the correction of accumulated compound.