Protective effect of ghrelin in a rat model of celiac disease.

Ghrelin is a gut hormone shown to have protective effects throughout the gastrointestinal tract. This study aims to investigate its protective effect in celiac disease induced in rats. Twenty-four rat pups were divided into 4 groups as follows: control, disease (1.5 mg/g intragastric gliadin), co-treatment (50 ng/g intraperitoneal ghrelin after gliadin gavage) and pretreatment (50 ng/g intraperitoneal ghrelin before gliadin gavage). Animals' weight gain was charted. Histological features assessed include villus length, villus width, crypt depth and number of intraepithelial lymphocytes. Tissue interferon-gamma was quantified by ELISA. ANOVA was used to compare results statistically. Results showed that villi were shortened in the diseased group, but were as long as the control in pretreatment and co-treatment groups. Crypt depth had increased in disease group, but turned to normal in co-treatment group. Number of intraepithelial lymphocytes was significantly higher in disease group than the control, while no difference was observed between co-treatment and control groups. Disease and control animals weighed equally at the end of the experiment, but ghrelin-treated animals had significantly gained more weight than these two. Interferon-gamma measurement revealed no significant difference among groups. We concluded administration of ghrelin led to histological improvement of celiac disease which was more obvious if administered after exposure to gliadin.

Comparison of intradermal and intramuscular administration of hepatitis B vaccine in neonates.

BACKGROUND: Hepatitis B virus (HBV) infection and its complications are among the most common diseases in Iran. National mass vaccination of neonates against hepatitis B was started in 1991, but was considered a costly venture. AIM: To compare the efficacy of low-dose intradermal HBV recombinant vaccine with standard intramuscular dose in neonates. METHOD: 165 apparently healthy neonates born in Shiraz were randomized to receive either 10 microg [corrected] of recombinant vaccine intramuscularly (IM; n=82) or 2 microg [corrected] vaccine intradermally (ID; n=83) at months 0, 1, 6. Anti-HBs titers were measured at 6 and 18 months after the first dose. RESULTS: 53 and 51 neonates in the IM and ID groups, respectively, completed the study. Protective anti-HBs titers (>10 IU/L) at 18 months after the first dose were achieved in 98.1% and 96.2% of neonates in IM and ID groups, respectively (p=ns). The only side effect in the ID group was local hyperpigmentation, which was seen in 55%; no significant side effect was reported in the IM group. CONCLUSION: Intradermal vaccination with 20% of standard dose is as effective as IM vaccination when evaluated at 18 months after the first dose.

Influence of monovalent cations on rat alpha- and beta-parvalbumin stabilities.

The mammalian genome encodes both alpha- and beta-parvalbumin isoforms. The rat beta-parvalbumin (aka "oncomodulin") is more stable than the alpha isoform at physiological pH and ionic strength, despite its substantially higher charge density and truncated C-terminal helix [Henzl, M. T., and Graham, J. S. (1999) FEBS Lett. 442, 241-245]. Reasoning that solvent interactions could contribute to this unexpected finding, we have examined the stabilities of the Ca(2+)-free alpha- and beta-parvalbumins as a function of Na(+) and K(+) concentration. Differential scanning calorimetry data suggest that, at physiological pH and ionic strength, the beta isoform binds roughly 2 equiv of Na(+) or a single equivalent of K(+) with moderate affinity. Under comparable conditions, the alpha isoform apparently binds just 1 equiv of Na(+) and essentially no K(+). Isothermal titration calorimetry experiments suggest that the bound monovalent ions occupy the EF-hand motifs. In 0.15 M K(+), at pH 7.4, the stability of the apo-beta-parvalbumin exceeds that of the alpha isoform by approximately 2.6 kcal/mol at 37 degrees C and by approximately 3.0 kcal/mol at 25 degrees C. The latter value represents a substantial fraction of the difference in Ca(2+)-binding free energies measured in vitro for the two proteins. Significantly, however, these results do not completely explain the paradoxical stability of the beta isoform, which maintains its higher melting temperature under all conditions examined.