High hydrostatic pressure processing of murine norovirus 1-contaminated oysters inhibits oral infection in STAT-1(-/-)-deficient female mice

We have previously demonstrated that high pressure processing (HPP) is effective in preventing in vitro replication of murine norovirus strain 1 (MNV-1), a human norovirus surrogate, in a monocyte cell line following extraction from MNV-1-contaminated oysters. In the present study, the efficacy of HPP to prevent in vivo replication within mice fed HPP-treated MNV-1-seeded oyster extracts was evaluated. Oyster homogenate extracts seeded with MNV-1 were given 5-min, 400-MPa (58,016-psi) treatments and orally gavaged into immunodeficient (STAT-1(-/-)) female mice. Mice orally gavaged with HPP-treated MNV-1 showed significant (P ≤ 0.05) weight loss leading to enhanced morbidity, whereas those given 100 and 200 PFU of HPP-treated MNV-1 were comparable to uninfected controls. MNV-1 was detected, via real-time PCR, within the liver, spleen, and brain of all mice fed non-HPP-treated homogenate but was not detected in the tissues of mice fed HPP-treated homogenates or in uninfected control mice. Hepatocellular necrosis and lymphoid depletion in the spleen were observed in non-HPP-treated MNV-1 mice only. These results clearly show that HPP prevents MNV-1 infection in vivo and validates that viral inactivation by HPP in vitro is essentially equivalent to that in vivo. Further, the data suggest that HPP may be an effective food processing intervention for norovirus-contaminated shellfish and thus may decrease risk to both immunocompromised and immunocompetent individuals who consume shellfish.     

Preventative activity of kimchi on high cholesterol diet-induced hepatic damage through regulation of lipid metabolism in LDL receptor knockout mice

Food Science and Biotechnology - This study investigated the effect of kimchi on hepatic lipid metabolism and inflammatory response. Low-density lipoprotein receptor knockout mice fed high...     

Pregnancy-induced changes in substance P and neurokinin 1 receptor (NK1-R) expression in the rat uterus

Adrenergic nerve fibres of the mammalian uterus degenerate during pregnancy. The behaviour of peptidergic fibres, such as substance P-positive fibres and of its preferred neurokinin 1 receptor (NK1-R), is poorly studied in the pregnant rat uterus. The present study analysed the changes in substance P immunoreactivity and in the expression of NK1-R protein in the uterus of non-pregnant, pregnant (days 7, 14 and 21) and postpartum rats (days 1, 8 and 22) by immunohistology, dot blot analysis and western blot analysis. In non-pregnant rats, substance P-positive fibres were localized to the myometrium; these fibres progressively disappeared during gestation and were almost absent at term (day 21). At day 22 post partum, substance P-positive fibres had recovered to numbers comparable with those in the non-pregnant uterus. Dot blot analysis revealed a significant decrease in the immunoreactivity of substance P in the uterus at mid-pregnancy (day 14) and especially at term. Expression of the NK1-R protein showed a progressive increase throughout pregnancy reaching a peak on day 1 post partum; downregulation of NK1-R protein occurred on day 8 post partum. The low and high expressions of NK1-R protein were coincident with a large number of eosinophils and almost no eosinophils in the uterus at oestrus and at term, respectively. It was concluded that substance P immunoreactivity is inversely correlated with NK1-R protein expression in the pregnant and postpartum uterus. The marked upregulation of NK1-R protein at term and after birth indicates that the NK1-R may be involved in the complex regulation of labour and postpartum physiology. However, it is likely that the NK1-protein is not involved in the recruitment of eosinophils into the uterus at oestrus.     

关于Diophantine方程(an-1)(bn-1)=x2的Cohn猜想

设a和b是两个不相等的正整数.针对Cohn猜想,即方程(an-1)(bn-1)=x2没有正整数解(x,n),其中n＞4.利用初等数论方法和指数Diophantine万程的性质,得到了如果a和b具有相反的奇偶性,那么方程没有满足n＞4和2| n的正整数解(x,n).     

Application of electron spin resonance (ESR) spectrometry in nutraceutical and food research

Electron spin resonance (ESR) spectroscopy is able to directly measure the chemical species with unpaired electrons and has been widely used in a number of research fields. This review focused on its application in nutraceutical and food research. Current status of ESR in free radical scavenging capacity estimation, food oxidative stability evaluation, Cu(2+) chelating capacity determination were summarized. Also discussed was the potential of ESR spin-label oximetry technique in examination of lipid peroxidation and oxygen diffusion-concentration products in liposomes, oxygen transport and depletion, and membrane structure and dynamic properties. In addition, ESR application in identifying and estimating irradiated foods including meat, fruits, vegetables, spices, cereal grains, and oil seeds was reviewed. Finally, the potential use of ESR technique in investigating microstructure change, phase transition and viscosity related properties during food formulation, processing, and storage was briefly mentioned, along with its potential in determination of radio-stability of food components. This review may provide some fundamental knowledge of ESR and its application in nutraceutical and food research.     

Holstein's milk detection in cheeses inferred from melanocortin receptor 1 (MC1R) gene polymorphism

For some French Registered Designation of Origin (RDO) cheeses Prim'Holstein's milk is not allowed for cheese making (e.g., Reblochon, Abondance, and Beaufort cheeses). To find molecular markers for Prim'Holstein's milk detection in RDO cheese, four genes affecting coat color in cattle (c-kit, MGH, TYRP1, and MC1R) have been sequenced for three mountain breeds and the Prim'Holstein breed. Only the MC1R gene (E-locus) has shown variation between the four breeds. Among the 25 French and Italian breeds sequenced for the MC1R gene, only the Vosgienne breed has presented the same allele as the black Prim'Holstein breed (E(D)). A quick and easy DNA-based method to detect Holstein's milk in RDO cheese is proposed based on ED allele detection. A DNA extraction from cheese, a preamplification of the gene and a competitive oligonuleotide priming PCR on MC1R mutations were performed. Using an automated sequencer, differences in fluorescence and fragment size reveal the allele type. This simple approach provides good reproducibility and is shown to be relatively sensitive, with a detection limit of about 1% of Holstein's milk in milk curd.     

Effect of partially hydrolyzed oat β-glucan on the weight gain and lipid profile of mice

Oat β-glucan hydrolysates with different molecular weights were prepared and their physicochemical, hypocholesterolemic, and weight-reducing characteristics were evaluated. The enzymatic hydrolysis by cellulase caused a decrease in the molecular weight of oat β-glucan (1450–370 × 10³ g/mol), which also affected swelling power and bile acid/fat binding capacities. In addition, mice were fed high-fat diet supplemented with β-glucans with three different molecular weights (1450, 730, 370 × 10³ g/mol). The diets treated with β-glucans significantly reduced the body weight of the mice. However, the molecular weight of β-glucans did not appear to significantly affect the serum lipid profile.     

The absence of rhamnose in human urine following the ingestion of gum karaya (Sterculia)

Urinary rhamnose estimations following ingestion of gum karaya were requested by the Scientific Committee for Food (EEC) in July 1983. Five male volunteers have therefore made 24-h urine collections prior to, and following, the ingestion of 10 g gum karaya for 15 days, an intake ten-fold greater than that approved in terms of the present temporary ADI (0-12 X 5 mg/kg b.w.). Paper chromatographic separations, with two solvent systems, were made on the fresh urine specimens and also after ten-fold enrichments of all urinary constituents. Standard aqueous solutions of rhamnose, and urine to which rhamnose had been added, showed the detection limit to be 0.2 microgram rhamnose. Independent examinations in two laboratories failed to detect rhamnose at this level in any of the urine specimens, Had 1% of the rhamnose present in 10 g gum karaya appeared in the 24-h urine specimens, it would have been detected. This confirms previous evidence that dietary gum karaya is neither digested nor degraded by enteric bacteria and is not absorbed to any significant extent in Man.     

Assessment of the effect of fermented papaya preparation on oxidative damage in spontaneously hypertensive rat brain using electron spin resonance (ESR) imaging and L-band ESR spectroscopy

Oxidative and nitrosative stress mechanisms are widely implicated in the biological and pathological processes involved in aging, cardiovascular and neurodegenerative diseases. Although this has continued to fuel suggestions of the benefits of antioxidant functional foods, in vivo methods for assessing the integrity of this remain limited. A novel electron spin resonance (ESR) technique for evaluating oxidative stress and location of its damage in the brain of spontaneously hypertensive rats (SHR) has been described [Lee, M.-C., et al. (2004). Assessment of oxidative stress in the SHR brain using electron spin resonance (ESR) imaging and in vivo L-Band ESR. Hypertension Research, 27, 485–492]. The reconstructed 2D ESR images of the distribution of a blood brain barrier-permeable nitroxyl spin probe, 3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (MC-PROXYL) was used to investigate the ability of fermented papaya preparation (FPP, a product of yeast fermentation of Carica papaya Linn.) to modulate oxidative stress of SHR brain. Supplementation (5–7 months) with FPP (50 mg/rat/day) significantly increased the decay of the ESR images of the MC-PROXYL, suggesting that FPP may have up-regulated the redox defense activity in the SHR brain. Herein is an in vivo noninvasive technique for the study of oxidative stress and its modulation by dietary factors (that may be intended for applications as neuroprotectants in chronic degenerative disease involving loss of brain function).     

Quantification of the Maillard reaction product 6-(2-formyl-1-pyrrolyl)-l-norleucine (formyline) in food

The Maillard reaction product 6-(2-formyl-1-pyrrolyl)-l-norleucine (formyline) was recently identified as a new pyrrole amino acid resulting from the reaction of free and protein-bound lysine residues with the 1,2-dicarbonyl compound 3-deoxypentosone, pentose sugars, and degradation products of disaccharides. In the present work, simultaneous analysis of formyline and its structural analog, pyrraline, in enzymatically hydrolyzed food matrices was achieved on an RP-phenyl column by high-pressure liquid chromatography (HPLC) with UV detection. The presence of formyline was for the first time unequivocally verified in the hydrolyzates and standard samples by HPLC coupled to triple quad mass spectrometry due to identity of product ion spectra after targeted fragmentation of the molecular ion of formyline. A total of 68 food samples were analyzed. Low concentrations of formyline were detected in milk and whey products. In breakfast cereals, pasta, and bakery products, formyline was quantified in concentrations up to 34.8?mg/kg. In the outmost bread crust, 0.6?% of lysine residues can be modified to formyline. Moreover, it was shown by analysis of concentrated beer samples that both formyline and pyrraline are constituents of beer proteins. From our data, we conclude that at least 2?C3?mg of formyline and 20?C40?mg of pyrraline are ingested with the daily diet.     

The bone‐protective effect of a Taiwanese yam (Dioscorea alata L. cv. Tainung No. 2) in ovariectomised female BALB/C mice

BACKGROUND: Yam products have been marketed for treating postmenopausal syndromes. This study investigated the effects of Dioscorea alata L. cv. Tainung No. 2 (TNG yam) on the bone density of ovariectomised (OVX) female BALB/c mice and the mechanism whereby TNG yam exerted this effect. Sham and OVX control groups were fed a control diet while remaining OVX mice were randomly allocated into experimental diets, i.e. yam (630 g TNG powder kg^?1), E2 (20 mg 17β‐oestradiol kg^?1), or genistein (2 g genistein kg^?1) diet. After 12 weeks of feeding, the uterine weight, indices of bone mass and caecal short chain fatty acids were determined. RESULTS: Neither a yam nor genistein diet restored the OVX‐induced uterine atrophy as did the E2 diet. The femoral and lumbar bone mineral density (BMD) of mice fed the yam diet was greater than those of the sham group, respectively (P < 0.05 vs OVX control), while the lumbar BMD of yam and sham groups were similar (P > 0.05 vs sham). The femoral ash and calcium content in the yam group was significantly greater than that in the OVX control group, respectively (P < 0.05 vs OVX control). The total short chain fatty acid content in the caecum, only enhanced in the yam group, was not correlated with the calcium content of either bone or the plasma calcium level. CONCLUSION: TNG yam prevented loss of BMD and improved bone calcium status without stimulating uterine hypertrophy in OVX BALB/c mice. TNG yam may be beneficial for postmenopausal women for preventing bone loss. Copyright © 2008 Society of Chemical Industry     

Treatment with Bifidobacterium bifidum 17 partially protects mice from Th1-driven inflammation in a chemically induced model of colitis

Probiotics have been suggested as an alternative therapeutical approach in the intervention of inflammatory disorders of the gastrointestinal tract (GIT). Application of single strains or probiotic mixtures has shown promising results in animal models and patients of inflammatory bowel disease (IBD). We recently demonstrated potent inhibitory capacity of a Bifidobacterium bifidum S17 on LPS-induced inflammatory events in cell culture models using intestinal epithelial cells and verified these anti-inflammatory effects in two mouse models of colitis. In the present study we analyze the anti-inflammatory effect of this potential probiotic strain in a chemically-induced model of colitis in C57BL/6 mice. This model is characterized by a strong type 1T helper (Th1) response resembling Crohn's disease, one of the two most prevalent forms of IBD. We performed macroscopic analysis and determined the effect of B. bifidum S17 on the cytokine balance in biopsies of the colonic mucosa. While treatment with B. bifidum S17 only had a marginal effect on weight loss, no difference was observed in the macroscopic parameters. However, a significant reduction in histology scores and the levels of pro-inflammatory cytokines interleukin 1β (IL-1β), interleukin 6 (IL-6), keratinocyte-derived chemokine (KC) and the inflammatory markers cyclooxigenase 2 (Cox-2) and myeloperoxidase (MPO) was observed. These results indicate that treatment with B. bifidum S17 is able to partially inhibit the strong Th1-driven intestinal inflammation induced in our model of colitis.     

Pig zona pellucida 2 (pZP2) protein does not participate in zona pellucida formation in transgenic mice

The zona pellucida, an extracellular matrix surrounding mammalian oocytes, is composed of three or four glycoproteins. It is well known that the zona pellucida plays several critical roles during fertilization, but there is little knowledge about its formation. The purpose of this study is to examine whether a pig zona pellucida glycoprotein 2 (pZP2) would assemble with mouse zona pellucida. A transgene construct was prepared by placing a minigene encoding pZP2 downstream from the promoter of mouse ZP2. The result showed that the transgenic protein was synthesized in growing oocytes but not incorporated into the zona pellucida. Furthermore, the pZP2 transgene did not rescue the phenotype in ZP2-knockout zona-deficient mice. These results indicate that pZP2 does not participate in mouse zona pellucida formation and the zona pellucida is constituted from its component proteins in a molecular species-specific manner between mice and pigs.     

实二次域Q(8k+1)~(1/2)上的正定幺模格

给出了实二次域Q(8k 1)~(1/2)上的正定幺模格种类及其邻格关系和邻格链个数.利用推广的邻格方法,对Q(17)~(1/2)上的秩≤4的所有正定幺模格进行了分类,给出了代表格.     

Comparison of chronic toxicity and carcinogenicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in 2-year bioassays in female Sprague-Dawley rats

The cancer bioassay for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) conducted by the Dow Chemical company in the mid 70s has been used extensively for conducting quantitative cancer risk assessments for human exposure to TCDD. More recently the National Toxicology Program (NTP) conducted a cancer bioassay of similar design as part of its evaluation of the dioxin toxic equivalency factor methodology. This report compares the design and the results of these two cancer bioassays. This comparison confirms, in most cases, previously published and widely used carcinogenic response characteristics with respect to dose, time course, organ selectivity, tumor type and maximum intensity of TCDD-induced carcinogenicity and toxicity in the Sprague-Dawley rat. Specifically, increases in the incidences of neoplasms were seen in both studies in the liver, lung and oral mucosa. The most notable difference was the significant increase in the incidence of cholangiocarcinoma of the liver seen in the NTP study but not in the Dow study. The experimental designs for the two studies are similar but some protocol parameters differed, such as vehicle, dosing schedule, diet and rat sub-strain utilized. Differences in the shapes of the dose response curves for several neoplasms were noted between the studies, with the NTP study showing non-linearity for all neoplasms. This may result from differences in the experimental protocols as well as divergence in the biological behavior of the different stocks of Sprague-Dawley rat strains used.     

Glycine metabolism in Candida albicans: characterization of the serine hydroxymethyltransferase (SHM1, SHM2) and threonine aldolase (GLY1) genes

Genes encoding the mitochondrial (SHM1) and cytosolic (SHM2) serine hydroxymethyltransferases, and the L-threonine aldolase gene (GLY1) from Candida albicans were cloned and sequenced. All three genes are involved in glycine metabolism. The C. albicans Shm1 protein is 82% identical to that from Saccharomyces cerevisiae and 56% identical to that from Homo sapiens. The corresponding identities for the Shm2 proteins are 68% and 53%. The Gly1 protein shares significant identity with the S. cerevisiae L-threonine aldolase (55%) and also with threonine aldolases from Aeromonas jandiae (36%) and Escherichia coli (36%). Genetic ablation experiments show that GLY1 is a non-essential gene in C. albicans and that L-threonine aldolase plays a lesser role in glycine metabolism than it does in S. cerevisiae. GenBank Accession Nos of the C. albicans SHM1 and SHM2 are AF009965 and AF009966, respectively. Accession No. for C. albicans GLY1 is AF009967.     

Sunblocking efficiency of various TiO(2)-loaded solid lipid nanoparticle formulations(1)

In this study, titanium dioxide (TiO(2)) was incorporated into solid lipid nanoparticle (SLN) formulations using both classical and novel preparation methods. The SLNs were investigated by evaluating their stabilities and physicochemical characteristics. UV-protection abilities of formulations were investigated using in vitro Transpore and Sun To See(TM) test methods. Results have been discussed by comparing the classical SLN formulation with the novel SLN, hybrid SLN (H-SLN) and the emulsion formulations. The results showed the superiority of the H-SLN formulations compared with the classical SLN; all SLN formulations were better when compared with the emulsion formulations considering the UV protection. Incorporation of TiO(2) as a sunscreen agent into SLN formulations gives opportunity to produce stable and safe formulations with reduced amount but high UV-protection ability.