[Spectral characterization for capsanthin molecule with in vitro oxidative defense reaction].

The changes of UV-Vis and FTIR spectroscopic properties for capsanthin before and after reaction with exogenous superoxide anion (*O2(-)), hydrogen peroxide (H2O2) and hydroxyl radical (*OH), catalase (CAT), peroxidase (POD) and lipoxygenase (LOX) were explored. The results showed that, the UV-Vis spectral absorption of capsanthin treated with reactive oxygen species had a blue-shift. At the same time, the FTIR spectra changed significantly. The number of FTIR spectral peaks reduced and theFTIR strength weakened for capsanthin molecule treated with *O2(-) and *OH. The characteristic and strong peaks moved to shorter wavelengths when treated with H2O2. And LOX caused breakage of capsanthin molecule and reduction of peak number or groups without carbonyl. Exogenous H2O2 + CAT or H2O2 + POD treatment could not affect the UV-Vis and FTIR spectra significantly. So ROS could cause oxidative degradation of capsanthin and destroy chromophoric groups such as carbon-carbon double bond and carbonyl, then grow colorless alcohols. Hence ROS and LOX should transforms the conjugate system of capsanthin molecules, while CAT and POD could protect the capsanthin.

[Dynamic changes of serum antibody titer in a rabbit model of Acanthamoeba keratitis].

Ten healthy New Zealand white rabbits were randomly divided into two groups named as experiment group (n=8) and normal control group (n=2). Left eyes were for experiment, right eyes served as control. New Zealand rabbits were each injected by subconjunctival route with hydrocortisone for three days, and then Acanthamoeba keratitis was induced by intrastromal injection of live Acanthamoeba healyi trophozoites and cysts. Eyes in control group were injected with equivalent volume of physiological saline. Corneal lesions of rabbits were recorded every day after injection, etiological diagnosis was carried out by corneal scraping. Blood samples were examined for serum antibody titer by ELISA. Corneas were removed for pathological examination. Corneal scraping and corneal histopathologic examination proved that experiment eyes were infected by Acanthamoeba, and appeared typical manifestations and pathological changes of Acanthamoeba keratitis. Serum antibody titer raised continuously with infection time and reached the highest level (A450 value=2.2358) on the 28th days post-infection, then began to decline and remained higher level than the control until the rabbits were sacrificed. In control group, no significant change in antibody titer had taken place.

Highly Efficient Deamidation of Wheat Gluten by Glucose-Citric Acid-Based Natural Deep Eutectic Solvent: A Potential Effective Reaction Media.

An efficient technique using citric acid and glucose based natural deep eutectic solvent (G-C-NADES) was developed to obtain ultrahigh deamidated wheat gluten (UDWG) (deamidation degree (DD) > 90%). FTIR and 1H NMR indicated intensive hydrogen bonds (HBs) in G-C-NADES supermolecules. Quantum chemical calculations and molecular dynamic simulations demonstrated that 10 wt % diluted G-C-NADES still had a myriad of HBs. Physicochemical results showed UDWG had DD up to 92.45% after G-C-NADES deamidation, that is, 22% higher than citric-acid-DWG with a weak degree of hydrolysis (1.75%). Conformational characterization demonstrated the obvious conversion from α-helix to ß-sheet via FTIR, the least amount of disulfide bonds by Raman spectra, and more exposure of tryptophan residues by fluorescence measurement for UDWG. It is proven that enhanced accessible conformation of WG reached with HBs of G-C-NADESs could contribute to the improvement on nucleophilic attack of deamidation, declaring that G-C-NADES might be a potential solvent for obtaining an ultrahigh deamidation for WG to successfully guarantee the safety of wheat gluten based cereal food regarding to lowering its allergy.

Vaccination with Bivalent DNA Vaccine of α1-Giardin and CWP2 Delivered by Attenuated Salmonella typhimurium Reduces Trophozoites and Cysts in the Feces of Mice Infected with Giardia lamblia.

BACKGROUND: Giardia lamblia is one of the most common infectious protozoans in human that may cause diarrhea in travelers. Searching for antigens that induced effectively protective immunity has become a key point in the development of vaccine against giardiasis. METHODOLOGY/PRINCIPAL FINDINGS: Mice vaccinated with G. lamblia trophozozite-specific α1-giardin DNA vaccine delivered orally by attenuated Salmonella typhimurium SL7027 elicited 74.2% trophozoite reduction, but only 28% reduction in cyst shedding compared with PBS buffer control. Oral vaccination with Salmonella-delivered cyst-specific CWP2 DNA produced 89% reduction in cysts shedding in feces of vaccinated mice. Significantly, the mice vaccinated with Salmonella-delivered bivalent α1-giardin and CWP2 DNA vaccines produced significant reduction in both trophozoite (79%) and cyst (93%) in feces of vaccinated mice. This parasite reduction is associated with the strong local mucosal IgA secretion and the IgG2a-dominant systemic immune responses in vaccinated mice. CONCLUSIONS: The results demonstrate that bivalent vaccines targeting α1-giardin and CWP2 can protect mice against the colonization of Giardia trophozoite and block the transformation of cyst in host at the same time, and can be used to prevent Giardia infection and block the transmission of giardiasis.

Construction and characterization of a full-lengh cDNA library from non-fresh Giardia lamblia.

OBJECTIVE: To construct rapidly a full-length cDNA library from nanogram amounts total RNA of Giardia lamblia (G. lamblia) trophozoites stocked in RNA stabilization reagent. METHODS: Total RNA of Giardia was extracted using Trizol reagent. A full-length cDNA library of G. lamblia trophozoites was constructed by a long-distance PCR (LD-PCR) method. The recombinant rate and the coverage rate of full-length clones of the library were evaluated. The inserted fragments were identified and sequenced by PCR amplification. RESULTS: The titer of cDNA library was 3.85 × 10(7) pfu/mL. The length of inserted fragments ranged from 0.4 to 2.5 kb, and the recombination efficiency accounted for 100% (20/20). The coverage rate of full-length clones is high (17/20). CONCLUSIONS: The RNA stabilization reagent may be used to fix the cells and prevent the RNA in cells even though delivered under normal atmospheric temperature. The long-distance PCR can be used to construct a full-length cDNA library rapidly and it needs less RNA than the traditional method from mRNA.