Cooking effects on water distribution in potatoes using nuclear magnetic resonance relaxation

Continuous low-field (LF) (1)H NMR relaxometry was used to monitor the structural changes during cooking of potatoes with two different dry matter (DM) contents. A principal component analysis of the relaxation decay curves revealed major events related to water mobility during cooking, which occur at 53 and 60 degrees C for potatoes with medium and low DM contents, respectively. Exponential analysis of the relaxation decays reveals two major water populations in the potato: a slow-relaxing (assigned to water in cytoplasm and extracellular cavities) water component, T(22) ( approximately 350-550 ms), and a fast-relaxing component (primarily assigned to water associated with starch and cell walls), T(21) ( approximately 45-65 ms). Significant DM dependent shifts in both the T(21) and T(22) relaxation time constants were observed during cooking, indicating that starch gelatinizes between 53 and 70 degrees C with water exchanging with the hydroxyls of starch (transition in T(21)) and cells start to disrupt with an increase in diffusion volumes at approximately 60 degrees C (transition in T(22)). The study reveals that continuous LF NMR measurement is an excellent and highly sensitive method to study changes in water mobility and water populations during the cooking of potatoes.     

Relationship between the metabolite profile and technological properties of bovine milk from two dairy breeds elucidated by NMR-based metabolomics

The aim of the present study was to investigate the relationship between the metabolite profile of milk and important technological properties by using nuclear magnetic resonance (NMR)-based metabolomics. The metabolomics approach was introduced for the metabolic profiling of a set of milk samples from two dairy breeds representing a wide span in coagulation properties. The milk metabolite profiles obtained by proton and carbon NMR spectroscopy could be correlated to breed and, more interestingly, also with the coagulation profile, as established by traditional methods by using principal component analysis (PCA). The metabolites responsible for the separation into breed could mainly be ascribed to carnitine and lactose, whereas the metabolites varying in the samples with respect to coagulation properties included citrate, choline, carnitine, and lactose. The results found in the present study demonstrated a promising potential of NMR-based metabolomics for a rapid analysis and classification of milk samples, both of which are useful for the dairy industry.     

Seasonal variation of provitamin D2 and vitamin D2 in perennial ryegrass (Lolium perenne L.)

Ergosterol (provitamin D(2)) is converted to vitamin D(2) in grass by exposure to UV light. Six varieties of perennial ryegrass (Lolium perenne L.) were harvested four times during the season, and the contents of vitamin D(2) and ergosterol were analyzed by a sensitive and selective liquid chromatography tandem mass spectrometry method. Weather factors were recorded, and a principal component analysis was performed to study which factors were important for the formation of vitamin D(2). The results suggest that a combination of weather factors is involved and that the contents of ergosterol and vitamin D(2) change more than a factor of 10 during the season. These results demonstrate that grass potentially can be a significant source of vitamin D for grazing animals and animals fed on silage and hay.     

Expression of messenger ribonucleic acid encoding for steroidogenic acute regulatory protein and enzymes, and luteinizing hormone receptor during the spring transitional season in equine follicles

The period of spring transition, from the anovulatory to the ovulatory season, is characterized in many mares by cyclical growth and regression of large dominant follicles. These follicles produce only low concentrations of estradiol and it is thought that acquisition of steroidogenic competence by large follicles during spring transition is prerequisite in stimulating LH prior to first ovulation. In situ hybridization was used to localize and quantify expression of factors that play a key role in follicular steroidogenesis: StAR, P450scc (CYP11A1), P450c17 (CYP17), P450arom (CYP19), and LH receptor (LHr). One ovary was obtained from mares on the day after detection of an actively growing 30 mm transitional anovulatory follicle (defined as the transitional follicle), and the remaining ovary was removed at the third estrus of the breeding season on the day after the preovulatory follicle reached 30 mm in diameter (defined as the preovulatory follicle). Messenger RNAs encoding StAR, CYP11A1, and CYP17 were detected only in theca cells and CYP19 mRNA was confined to the granulosa layer. There was significantly lower expression of mRNAs for the steroidogenic enzymes, StAR (P<0.001) and LHr (P<0.05) in transitional follicles than in preovulatory follicles. In conclusion, large equine follicles during spring transition have low levels of mRNA encoding steroidogenic enzymes, StAR and LHr which will contribute to the steroidogenic incompetence of dominant follicles during spring transition and their subsequent regression.     

Inhibition of virulence gene expression in Staphylococcus aureus by novel depsipeptides from a marine photobacterium

During a global research expedition, more than five hundred marine bacterial strains capable of inhibiting the growth of pathogenic bacteria were collected. The purpose of the present study was to determine if these marine bacteria are also a source of compounds that interfere with the agr quorum sensing system that controls virulence gene expression in Staphylococcus aureus. Using a gene reporter fusion bioassay, we recorded agr interference as enhanced expression of spa, encoding Protein A, concomitantly with reduced expression of hla, encoding α-hemolysin, and rnaIII encoding RNAIII, the effector molecule of agr. A marine Photobacterium produced compounds interfering with agr in S. aureus strain 8325-4, and bioassay-guided fractionation of crude extracts led to the isolation of two novel cyclodepsipeptides, designated solonamide A and B. Northern blot analysis confirmed the agr interfering activity of pure solonamides in both S. aureus strain 8325-4 and the highly virulent, community-acquired strain USA300 (CA-MRSA). To our knowledge, this is the first report of inhibitors of the agr system by a marine bacterium.     

A CAPS marker derived from tomato 12-oxophytodienoate reductase shows putative co-segregation with potato late blight resistance

The jasmonic acid (JA) pathway is involved in the defense mechanisms induced in plants on pathogen attack and the enzyme 12-oxophytodienoate reductase (OPR3) catalyses one of the final steps of JA synthesis. A CAPS marker, OprDM, has been developed using primers designed from the tomato (Solanum lycopersicum)OPR3 cDNA sequence. Sequencing verified that the sequence of the marker derived from potato (Solanum tuberosum) genomic DNA was 98% identical to the corresponding section of that from tomatoOPR3 cDNA. The marker was mapped and examined for association with QTLs for resistance to foliage late blight in potato. OprDM mapped close to marker GP121 on chromosome VII ofS. tuberosum. No marker sequence or clone forOPR3 has previously been mapped in potato or tomato. Results indicated the presence of two putative QTLs for foliage resistance on chromosome VII close to OprDM and CP56. The marker primers could be useful in other studies involving enzymes of the JA synthesis pathway in polymorphicSolanum populations.     

Coenzyme Q9 provides cardioprotection after converting into coenzyme Q10

Coenzyme Q10 (CoQ10) has been extensively studied as adjunctive therapy for ischemic heart disease, and its cardioprotective ability is well-established. The mitochondrial respiratory chain contains several coenzymes, including CoQ1, CoQ2, CoQ4, CoQ6, CoQ7, CoQ8, CoQ9, and CoQ10. It is not known whether other CoQs, especially CoQ9, is equally cardioprotective as CoQ10. The present study was designed to determine if CoQ 9 could protect guinea pig hearts from ischemia reperfusion injury. Guinea pigs were randomly divided into three groups: groups I and II were fed CoQ 9 and CoQ10, respectively, for 30 days while group III served as control. After 30 days, the guinea pigs were sacrificed and isolated hearts were perfused via working mode were subjected to 30 min ischemia followed by 2 h of reperfusion. Cardioprotection was assessed by evaluating left ventricular function, ventricular arrhythmias, myocardial infarct size, and cardiomyocyte apoptosis. Samples of hearts were examined for the presence of CoQ9 and CoQ10. The results demonstrated that both CoQ9 and CoQ10 were equally cardioprotective, as evidenced by their abilities to improve left ventricular performance and to reduce myocardial infarct size and cardiomyocyte apoptosis. High performance liquid chromatographic (HPLC) analysis revealed that a substantial portion of CoQ9 had been converted into CoQ10. The results indicate that CoQ9 by itself, or after being converted into CoQ10, reduced myocardial ischemia/reperfusion-induced injury.     

Induction and sequencing of Rousette bat interferon alpha and beta genes

Bats are considered to be natural reservoirs for several viruses of clinical importance, including rabies virus, Nipah virus, and Hendra virus. Type I interferons (IFNs) is an important part of the immune system in the defense against viral infection. To investigate the function of type I IFNs upon viral infection in bats, the nucleic acid, and amino acid sequences of Egyptian Rousette (Rousettus aegyptiacus) IFN-alpha and -beta were characterized. Sequence data indicated that bat IFN-alpha consists of 562-bp encoded 187-aa, and IFN-beta consisted of 558-bp encoded 186-aa. Phylogenetic analysis of the overall identity of IFN-beta shared the highest sequence homology with pig IFN-beta in both nucleotide and amino acid level. Stimulation of bat primary kidney cells (BPKCs) and bat lung cell lines, Tb-1 Lu, with polyinosinic-polycytidylic acid (poly(I:C)) or exogenous bat type I IFNs resulted in increased type I IFNs mRNA expression in BPKCs, but not in Tb-1 Lu. Characterization of the bat IFN-alpha and -beta genes allows understanding of the immune responses upon stimulation in different tissues, thus providing practical strategies for control and treatment of clinically important diseases. These results are important especially for the virus infection, and suggest that future molecular studies on virus infection experiment of bats in vitro will require careful consideration of the differences of type I IFN expression patterns in different cell types.