Effects of Siraitia grosvenorii extract on nonalcoholic steatohepatitis-like lesions in Sprague Dawley rats fed a choline-deficient, methionine-lowered, l-amino acid-defined diet.

Siraitia grosvenorii is the fruit of a cucurbitaceous vine endemic to China. Its extract has been used as a sweetener and exhibits various anti-inflammatory and anticarcinogenic effects mediated via its antioxidant properties. In the present study, we aimed to clarify the preventive or ameliorative effects of S. grosvenorii extract (SGE) on nonalcoholic steatohepatitis-like lesions induced in male Hsd: Sprague Dawley rats fed a choline-deficient, methionine-lowered, l-amino acid-defined diet for 13 weeks. This diet increased hepatotoxicity parameters and upregulated the expression of inflammation- and fibrosis-related genes in the liver, resulting in the progression of hepatic lesions, oxidative stress, hepatocellular apoptosis, and fibrosis. Furthermore, this diet upregulated the expression of phosphorylated nuclear factor-κB (NF-κB) and CD44. SGE administration inhibited these lesions, similar to CD44, a factor that controls hepatic inflammation and fibrosis. These results revealed that SGE impacts the disease stage via antioxidative effects and regulation of CD44 expression. SGE was found to be useful for preventing and treating steatohepatitis.

Nonobese mice with nonalcoholic steatohepatitis fed on a choline-deficient, l-amino acid-defined, high-fat diet exhibit alterations in signaling pathways.

Nonalcoholic steatohepatitis (NASH) is often associated with obesity, but some patients develop NASH without obesity. The physiological processes by which nonobese patients develop NASH and cirrhosis have not yet been determined. Here, we analyzed the effects of dietary methionine content on NASH induced in mice fed on a choline-deficient, methionine-lowered, l-amino acid-defined high-fat diet (CDAHFD). CDAHFD with insufficient methionine induced insulin sensitivity and enhanced NASH pathology, but without obesity. In contrast, CDAHFD with sufficient methionine induced steatosis, and unlike CDAHFD with insufficient methionine, also induced obesity and insulin resistance. Gene profile analysis revealed that the disease severity in CDAHFD may partially be due to upregulation of the Rho family GTPases pathway and mitochondrial and nuclear receptor signal dysfunction. The signaling factors/pathways detected in this study may assist in future study of NASH regulation, especially its 'nonobese' subtype.

A trans fatty acid substitute enhanced development of liver proliferative lesions induced in mice by feeding a choline-deficient, methionine-lowered, L-amino acid-defined, high-fat diet.

BACKGROUND: Nonalcoholic steatohepatitis (NASH) is a form of liver disease characterized by steatosis, necroinflammation, and fibrosis, resulting in cirrhosis and cancer. Efforts have focused on reducing the intake of trans fatty acids (TFAs) because of potential hazards to human health and the increased risk for NASH. However, the health benefits of reducing dietary TFAs have not been fully elucidated. Here, the effects of TFAs vs. a substitute on NASH induced in mice by feeding a choline-deficient, methionine-lowered, L-amino acid-defined, high-fat diet (CDAA-HF) were investigated. METHODS: Mice were fed CDAA-HF containing shortening with TFAs (CDAA-HF-T(+)), CDAA-HF containing shortening without TFAs (CDAA-HF-T(-)), or a control chow for 13 or 26 weeks. RESULTS: At week 13, NASH was induced in mice by feeding CDAA-HF-T(+) containing TFAs or CDAA-HF-T(-) containing no TFAs, but rather mostly saturated fatty acids (FAs), as evidenced by elevated serum transaminase activity and liver changes, including steatosis, inflammation, and fibrosis. CDAA-HF-T(-) induced a greater extent of hepatocellular apoptosis at week 13. At week 26, proliferative (preneoplastic and non-neoplastic) nodular lesions were more pronounced in mice fed CDAA-HF-T(-) than CDAA-HF-T(+). CONCLUSIONS: Replacement of dietary TFAs with a substitute promoted the development of proliferation lesions in the liver of a mouse NASH model, at least under the present conditions. Attention should be paid regarding use of TFA substitutes in foods for human consumption, and a balance of FAs is likely more important than the particular types of FAs.

Correction: Base recognition by l-nucleotides in heterochiral DNA.

[This corrects the article DOI: 10.1039/C2RA01013E.].

Verification of a false positive in a two-year rat carcinogenicity study using dual control groups.

There is sometimes controversy over whether or not statistically significant responses produced in carcinogenicity studies have biologically significance. Ambiguous results from our previous two-year oral carcinogenicity study on acotiamide hydrochloride hydrate (acotiamide-HH), a prokinetic drug for functional dyspepsia, in rats made it unclear whether the drug may exhibit uterine carcinogenicity. To check this finding, we performed a second long-term carcinogenicity study using two identical control groups to more accurately evaluate uterine carcinogenesis by considering the incidence of spontaneous neoplasms. Female Fischer 344 rats were divided into three groups: the two control groups (control 1 and 2) were administered vehicle (0.5% w/v methylcellulose) and the acotiamide-HH-treated group was administered 2,000 mg/kg/day of acotiamide-HH by oral gavage for two years. Among all groups, the incidence of endometrial adenocarcinoma (EmA) was highest in the control 2 group, followed by the acotiamide-HH-treated group and the control 1 group. Moreover, acotiamide-HH did not affect the incidence of precursor lesions of EmA. In cases where an ambiguous difference is observed, the use of two control groups allows for a more informed interpretation of the findings in the drug-treated groups. The outcomes in this study strongly support the hypothesis that the increase in EmA in rats treated with acotiamide-HH in our previous study is unrelated to administration of the drug.

Progression process and safety assessment adaptation of endometrial lesions in ENU-induced 2-stage uterine carcinogenicity in a Tg-rasH2 mouse model.

Although acotiamide hydrochloride hydrate (acotiamide-HH) has not been reported to have genotoxic findings in any of the genotoxicity studies or treatment-related toxicological findings in reproductive and developmental studies, suspicious uterine tumorigenesis was observed in the results of a long-term rat carcinogenicity study. To clarify the uterine tumorigenesis of acotiamide-HH, we performed a 2-stage uterine carcinogenicity model in the transgenic rasH2 mouse initiated by N-Ethyl-N-nitrosourea (ENU). This model facilitated the short-term detection of uterine carcinogenic potential, and it appears to be a very useful testing method for assessing the safety of chemicals that may affect uterine tumorigenesis. However, there have not been many reports on this model, and accumulation of case studies using this model is recommended to support its usability. In this study, we performed this carcinogenesis model to not only confirm uterine tumorigenesis of acotiamide-HH but also to confirm the reliability of the model. The results of this study revealed that the endometrial adenocarcinoma found in the long-term rat carcinogenicity study possibly arose spontaneously. Also, we confirmed early induction of a uterine tumor as in previous reports and confirmed that 26 weeks is the appropriate treatment period for this rasH2 mouse model according to time-course observations of uterine tumor development.

Neuroanatomic pathway associated with attentional deficits after stroke.

We used magnetic resonance imaging (MRI) and the statistical parametric mapping (SPM) image analysis technique to localize lesions in post-stroke patients with attention deficits. SPM can be used to combine image data from multiple participants and correlate these images with other data sets. Magnetic resonance imaging acquisitions were obtained from 115 post-stroke patients, who were systemically assessed for attention deficits using a standardized test (the Clinical Assessment for Attention; CAT) that probes various domains of attention. We created an SPM that displayed an association between lesion location and attention deficit severity. The overlay plots were localized to the right hemisphere during a visual cancellation test, and were localized to the left hemisphere during other attention tests. Cortical lesion varied across specific test domain, whereas lesions from the thalamus to the basal ganglia on the dominant side were associated with performance across all attention tests/domains. Our findings are suggestive of a large-scale multimodal attentional network associated with the thalamus/basal ganglia.

Thermal stability of oligodeoxynucleotide duplexes containing l-deoxynucleotide at termini.

The effects of substituting l-deoxynucleotide for d-deoxynucleotide at duplex termini were evaluated and the terminal substitutions were found to show much less effects on duplex destabilization and to show a similar tendency in base pairing selectivity, compared with internal chiral substitutions.

Effects of polaprezinc on morphological change of the tongue in zinc-deficient rats.

OBJECTIVE: To examine the effects of polaprezinc on morphologic change of the tongue epithelium and on cell cycle regulation of taste bud cells by using zinc-deficient rats, an animal model of taste disturbance. METHODS: After 28 days of feeding with zinc-sufficient or -deficient diet, the rats fed a zinc-deficient diet were divided into four groups in which 0, 1, 3 and 10 mg/kg of polaprezinc were administered for 28 days with continuation of diet. Histopathological and morphological examinations of the tongue were carried out. RESULTS: Parakeratosis was observed in all rats receiving the zinc-deficient diet and 1 mg/kg polaprezinc but not in rats receiving 3 and 10 mg/kg polaprezinc. The ratio of keratinizing epithelium in the outer and inner circumference were significantly increased from 9.6% and 11.3%, respectively, in zinc-sufficient rats to 36.9% and 32.9%, respectively, in zinc-deficient rats (P<0.001 and <0.01). This increase was reversed to 13.7% and 12.3% in rats that received 3 and 10 mg/kg polaprezinc in the outer circumference, respectively. Same phenomenon was seen in the inner circumference part, 13.0% and 10.8% (P<0.01), respectively. In addition, proliferating cell nuclear antigen-positive cells in the taste bud were significantly decreased from 75.5% in zinc-sufficient rats to 32.2% in zinc-deficient rats (P<0.001). This decrease was reversed to 70.3%, 83.1% and 81.2% in rats that received 1, 3 and 10 mg/kg polaprezinc, respectively. CONCLUSION: Polaprezinc improves parakeratosis and decreases taste bud cell proliferation caused by zinc deficiency. These effects may be involved in mechanisms underlying improvement of taste disorders in animal models.

Pathology of whooper swans (Cygnus cygnus) infected with H5N1 avian influenza virus in Akita, Japan, in 2008.

Two (1 adult and 1 young bird) of 4 H5N1-highly-pathogenic-avian-influenza (HPAI)-virus-infected whooper swans in Akita, Japan, in 2008 were investigated pathologically. Macroscopically, white spots with hemorrhages were scattered in the pancreas in the adult bird. Histologically, the adult bird had severe necrotizing pancreatitis and mild nonpurulent encephalitis. The young bird had severe nonpurulent encephalitis and nonpurulent enteric ganglionitis, and intestinal venous wall thickening. Virus antigens were detected in the lesions of pancreatitis in the adult bird and of encephalitis in adult and young birds. These findings suggest that the swans died or became moribund due to neurological disorders and necrotizing pancreatitis caused by H5N1 HPAI virus infection.

Binding of Porphyromonas gingivalis fimbriae to Treponema denticola dentilisin.

Treponema denticola has been reported to coaggregate with Porphyromonas gingivalis and localize closely together in matured subgingival plaque. In this study of the interaction of T. denticola with P. gingivalis, the P. gingivalis fimbria-binding protein of T. denticola was identified by two-dimensional electrophoresis followed by a ligand overlay assay with P. gingivalis fimbriae, and was determined to be dentilisin, a chymotrypsin-like proteinase of T. denticola. The binding was further demonstrated with a ligand overlay assay using an isolated GST fusion dentilisin construct. Our results suggest that P. gingivalis fimbriae and T. denticola dentilisin are implicated in the coaggregation of these bacteria.

2,3,7,8-Tetrachlorodibenzo-p-dioxin toxicity in the zebrafish embryo: altered regional blood flow and impaired lower jaw development.

The effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure on regional red blood cell (RBC) perfusion rate, as an index of blood flow, and lower jaw development were investigated quantitatively in zebrafish embryos (Danio rerio) during early development. As revealed by observation of live embryos and alcian-blue staining, TCDD retarded lower jaw development in a concentration-dependent manner with only a minor inhibitory effect on total body length. Both inhibitory effects were significant as early as 60 h postfertilization (hpf), at which time the area of goosecoid (gsc) mRNA expression was clearly reduced in the lower jaw. To examine effects of TCDD on RBC perfusion rate, time-lapse recording was performed using a digital video camera attached to a light microscope. TCDD did not show marked effects on RBC perfusion rate until 72 hpf, when vessel-specific effects emerged. TCDD severely inhibited RBC perfusion rate in intersegmental arteries of the trunk, but only modestly and slightly inhibited RBC perfusion rate in certain vessels of the head such as the central arteries and optic vein. Conversely, at both 72 and 84 hpf, TCDD significantly increased RBC perfusion rate in the hypobranchial artery branching to the lower jaw primordia, and then reduced it at 96 hpf. RBC perfusion rate in all vessels examined in TCDD-exposed embryos was inhibited at 96 hpf. The zebrafish aryl hydrocarbon receptor 2 (zfAhR2) mRNA was strongly expressed in the lower jaw primordia at 48 hpf, and expression of this transcript was augmented by TCDD treatment. Thus, TCDD exposure of the zebrafish embryo has a disruptive effect on local circulation and lower jaw cartilage growth. Initially, TCDD may act directly on the lower jaw primordia to impair lower jaw development. Reductions in hypobranchial RBC perfusion rate occurred well after the initial retardation in lower jaw development had become apparent, and may contribute further to the effect.