Cytotoxicity for porcine islet cells by complement of six animal species

Complement-mediated cytotoxicity for porcine islet cells (PICs) was evaluated using sera of six animal species. Then soluble complement receptor type-1 (sCR1) as an anti-complement agent was added to those sera, and the changes in 50% hemolytic unit of complement serum (CH50) and cytotoxic effect of those sera on PICs were examined. All the sera except for that of pig showed cytotoxicity. However, the extent of toxicity was considerably different between species. In the rat and human serum, sCR1 significantly reduced CH50 and cytotoxicity, however in the dog serum, sCR1 had no suppressive effects. These results may suggest that complement contribute to humoral cytotoxicity for PICs as a main factor, and the compatibility of complement with PICs differs between animal species.     

Reddish coloration of Chinese quince (Pseudocydonia sinensis) procyanidins during heat treatment and effect on antioxidant and antiinfluenza viral activities

To investigate the effects of processing Chinese quince fruit on the denaturation of phenolics and their food functions, fruit phenolic extracts were heated together with organic acid for up to 12 h. Chinese quince phenolic (mostly procyanidins) solution subjected to heat treatment changed from almost colorless, pale yellow, to a reddish color. Before heat treatment, the absorption spectra of polymeric procyanidins were observed only around 280 nm; after heat treatment, absorption occurred between 400 and 600 nm, which is related to the reddish color appearance. Thioacidolysis of denatured reddish phenolics showed that (-)-epicatechin subunits decreased during heat treatment and, in contrast, cyanidin increased. In addition, novel substances that could not be degraded by thioacidolysis were formed. Meanwhile, antioxidant activities, assessed by linoleic acid peroxidation, 1,1-diphenyl-2-picrylhydrazyl (DPPH), Folin-Ciocalteu, and FRAP methods, increased during heat treatment. The antiinfluenza viral activity of denatured reddish phenolics was inferior to that of intact fruit phenolics; however, they retained moderate activity. These results indicate that red coloration of fruit products of Chinese quince was mainly due to the spectral (i.e. structural) changes of procyanidins accompanied with formation of cyanidin. Increasing the length of heat treatment increased the antioxidant capacity of phenolics, and the resultant reddish phenolics retained moderate antiinfluenza viral activity.     

Comparison of the antioxidant activities of 22 commonly used culinary herbs and spices on the lipid oxidation of pork meat

The antioxidant activities of 22 selected culinary herbs and spices (i.e. ginger, cinnamon, clove, bay, sage, rosemary, thyme, savory, oregano, sweet basil, parsley, coriander, tarragon, sansho, allspice, cumin, black and white peppercorns, nutmeg, caraway, dill and fennel) when they were added to pork homogenate were measured and expressed as a thiobarbituric acid (TBA) value. The addition of liquid extracts of all the herbs and spices significantly suppressed lipid oxidation of the pork, especially the extracts of sansho, sage and ginger, which showed the strongest inhibition of lipid oxidation.     

Effect of modified oligopeptides from the beetle Allomyrina dichotoma on Escherichia coli infection in mice

The novel peptides based on a putative active site of defensin, an anti-bacterial peptide from the beetle Allomyrina dichotoma, were synthesized. These synthetic oligopeptides exhibited strong anti-bacterial activity in vitro, even against antibiotic-resistant pathogenic bacteria. Then, anti-bacterial activity of two newly synthesized peptides, RLYLRIGRR-NH(2) (peptide A) and RLRLRIGRR-NH(2) (peptide B) was also examined by macroscopic and histopathologic assessment during the course of infection in mice inoculated with antibiotic-resistant pathogenic Escherichia coli (E. coli) in vivo. Peptide B decreased the mortality of mice inoculated with antibiotic-resistant pathogenic E. coli. The results of macroscopic and histopathologic examinations revealed that peptide B could protect the mice from infection. In contrast, peptide A failed to protect mice from infection with antibiotic-resistant pathogenic E. coli. Also, modified peptides A and B produced no toxicity or side effects in mice. These results suggest that peptide B is useful for developing novel antibiotics against antibiotic-resistant pathogenic bacteria.     

PCR-based discrimination of Toxoplasma gondii from pigs at an abattoir in Okinawa, Japan

To determine the prevalence of the 3 primary clonal lineages of Toxoplasma gondii (strain types I, II, and III) in pigs in Okinawa Prefecture, we analyzed lymph node samples that had been collected at an abattoir by PCR analysis using primers specific for the Toxoplasma gondii SAG2 locus. This study revealed the presence of this parasite in 57 out of 101 samples examined. Restriction fragment length polymorphism (RFLP) in PCR-amplified SAG2 products was used to group strains into one of the three genotypes of T. gondii. Genotypes I and II were equally predominant, accounting for 22 (44.9%) and 23 (46.9%) of 49 SAG2-positive samples, respectively, while the type III strain was found in only 4 (8.2%) of the 49 samples. The other 8 samples were indistinguishable by PCR-RFLP analysis. Polymorphisms for the 3 genotypes were confirmed at the sequence level for several samples using the sequences from the RH strain, the Beverley strain, and the C56 strain as references. On the other hand, the dihydropteroate synthase gene, which is responsible for sulfonamide resistance, was amplified in 40 of 54 SAG2-positive samples by PCR with the specific primers, and further RFLP and sequence analysis revealed that none of them carried the drug-resistant form of the dhps gene. This is the first report of genotyping of T. gondii distributed in Japan.     

Plasma Profiles of Glucose, Insulin and Lipids in the Male WBN/Kob-Lepr(fa) Rat, a New Model of Type 2 Diabetes with Obesity

Plasma profiles of glucose, insulin and lipids were examined in the male WBN/Kob-Lepr(fa) (fa/fa) rat, a new model of type 2 diabetes (T2D), in comparison with age-matched original male WBN/Kob (lean) rats. The fa/fa rats developed hypertriglycemia, obesity and hyperglycemia from 5, 7, and 9 weeks of age, respectively. Plasma insulin levels in fa/fa rats were significantly higher than those in lean rats at 5 weeks of age, but after 11 weeks of age gradually declined to the levels in lean rats. HOMA-IR, a measure of insulin resistance status, showed that fa/fa rats had insulin resistance. The fa/fa rat has the potential to become an important animal model of T2D with obesity.     

Occurrence of Mycobacterium avium subsp. paratuberculosis in milk at dairy cattle farms: a systematic review and meta-analysis

Presence of Mycobacterium avium subsp. paratuberculosis (MAP) in milk for human consumption is a concern due to its possible relationship with Crohn's disease in humans. Pasteurization effectively reduces the MAP load by four to five logs, but the efficacy depends on the MAP concentration, which depends on the prevalence among contributing herds and individuals. Considerable variation of MAP in bulk tank milk (BTM) and individual cow's milk (IM) is reported, but factors associated with MAP occurrence in milk at farm level have not been described. This study systematically reviewed published studies aiming at estimating the occurrence of MAP in on-farm BTM and IM by meta-analysis. A total of 692 articles were identified through electronic databases and initially screened using title and abstract. The quality of the 61 potentially relevant articles was assessed using full text and 31 articles were eventually included in the meta-analysis. The apparent prevalence (AP) of MAP in BTM and IM on farm were summarized in relation to strata defined by the test used to identify MAP and the infection status of the herds/animals. There was considerable inconsistency in the reporting, resulting in missing information potentially explaining the dispersion in the estimated AP. The overall AP and 95% confidence intervals based on PCR and culture of MAP were summarized to 0.10 (0.04-0.22) in BTM and 0.20 (0.12-0.32) in IM. Quantifying the MAP load in test-positive milk samples was not possible because very few articles provided quantitative information on individual samples.     

Toxoplasma gondii antibody prevalence and isolation in free-ranging cats in Okinawa,Japan

Cats are an important host of Toxoplasma gondii from an epidemiological perspective because they are the only definitive hosts that excrete oocysts in their feces. In this study, 201 free-ranging cats in Okinawa were examined for T. gondii infection. Using the latex agglutination test, we detected antibodies against T. gondii in 26.9% (54/201) of the cats. Oocysts of T. gondii were not detected upon microscopic examination of the feces of 128 cats. T. gondii was isolated from the tissues of 9 out of 24 seropositive or pseudo-seropositive cats with a bioassay using laboratory mice. Genotyping for the GRA6 gene revealed that five and four of the isolates were type I and II, respectively.