bluuebunny/crossref_metadata_2025 huggingface dataset:
One size fits all? Molecular evidence for a commonly inherited petal identity program in Ranunculales
Authors: Rasmussen David A. , Kramer Elena M. , Zimmer Elizabeth A.
Published: December 2008

Petaloid organs are a major component of the floral diversity observed across nearly all major clades of angiosperms. The variable morphology and development of these organs has led to the hypothesis that they are not homologous but, rather, have evolved multiple times. A particularly notable example of petal diversity, and potential homoplasy, is found within the order Ranunculales, exemplified by families such as Ranunculaceae, Berberidaceae, and Papaveraceae. To investigate the molecular basis of petal identity in Ranunculales, we used a combination of molecular phylogenetics and gene expression analysis to characterize APETALA3 (AP3) and PISTILLATA (PI) homologs from a total of 13 representative genera of the order. One of the most striking results of this study is that expression of orthologs of a single AP3 lineage is consistently petal‐specific across both Ranunculaceae and Berberidaceae. We conclude from this finding that these supposedly homoplastic petals in fact share a developmental genetic program that appears to have been present in the common ancestor of the two families. We discuss the implications of this type of molecular data for long‐held typological definitions of petals and, more broadly, the evolution of petaloid organs across the angiosperms.
Amborella trichopoda (Amborellaceae) and the evolutionary developmental origins of the angiosperm progamic phase
Authors: Williams Joseph H.
Published: December 2008

A remarkable number of the defining features of flowering plants are expressed during the life history stage between pollination and fertilization. Hand pollinations of Amborella trichopoda (Amborellaceae) in New Caledonia show that when the stigma is first receptive, the female gametophyte is near maturity. Pollen germinates within 2 h, and pollen tubes with callose walls and plugs grow entirely within secretions from stigma to stylar canal and ovarian cavity. Pollen tubes enter the micropyle within 14 h, and double fertilization occurs within 24 h. Hundreds of pollen tubes grow to the base of the stigma, but few enter the open stylar canal. New data from Amborella, combined with a review of fertilization biology of other early‐divergent angiosperms, show that an evolutionary transition from slow reproduction to rapid reproduction occurred early in angiosperm history. I identify increased pollen tube growth rates within novel secretory carpel tissues as the primary mechanism for such a shift. The opportunity for prezygotic selection through interactions with the stigma is also an important innovation. Pollen tube wall construction and substantial modifications of the ovule and its associated structures greatly facilitated a new kind of reproductive biology.
Darwin's second “abominable mystery”: Why are there so many angiosperm species?
Authors: Crepet William L. , Niklas Karl J.
Published: December 2008

The rapid diversification and ecological dominance of the flowering plants beg the question “Why are there so many angiosperm species and why are they so successful?” A number of equally plausible hypotheses have been advanced in response to this question, among which the most widely accepted highlights the mutually beneficial animal–plant relationships that are nowhere better developed nor more widespread than among angiosperm species and their biotic vectors for pollination and dispersal. Nevertheless, consensus acknowledges that there are many other attributes unique to or characteristic of the flowering plants. In addition, the remarkable coevolution of the angiosperms and pollination/dispersal animal agents could be an effect of the intrinsic adaptability of the flowering plants rather than a primary cause of their success, suggesting that the search for underlying causes should focus on an exploration of the genetic and epigenetic mechanisms that might facilitate adaptive evolution and speciation. Here, we explore angiosperm diversity promoting attributes in their general form and draw particular attention to those that, either individually or collectively, have been shown empirically to favor high speciation rates, low extinction rates, or broad ecological tolerances. Among these are the annual growth form, homeotic gene effects, asexual/sexual reproduction, a propensity for hybrid polyploidy, and apparent “resistance” to extinction. Our survey of the literature suggests that no single vegetative, reproductive, or ecological feature taken in isolation can account for the evolutionary success of the angiosperms. Rather, we believe that the answer to Darwin's second “abominable mystery” lies in a confluence of features that collectively make the angiosperms unique among the land plants.
Seed ferns from the late Paleozoic and Mesozoic: Any angiosperm ancestors lurking there?
Authors: Taylor Edith L. , Taylor Thomas N.
Published: December 2008

Five orders of late Paleozoic–Mesozoic seed ferns have, at one time or another, figured in discussions on the origin of angiosperms, even before the application of phylogenetic systematics. These are the Glossopteridales, Peltaspermales, Corystospermales, Caytoniales, and Petriellales. Although vegetative features have been used to suggest homologies, most discussion has focused on ovulate structures, which are generally interpreted as megasporophylls bearing seeds, with the seeds partially to almost completely enclosed by the megasporophyll (or cupule). Here we discuss current information about the reproductive parts of these plants. Since most specimens are impression‐compression remains, homologizing the ovulate organs, deriving angiospermous homologues, and defining synapomorphies remain somewhat speculative. Although new specimens have increased the known diversity in these groups, a reconstruction of an entire plant is available only for the corystosperms, and thus hypotheses about phylogenetic position are of limited value. We conclude that, in the case of these seed plants, phylogenetic analysis techniques have surpassed the hard data needed to formulate meaningful phylogenetic hypotheses. Speculation on angiosperm origins and transitional stages in these fossils provides for interesting discussion, but currently it is still speculation, as the role of these groups in the origin of angiospermy continues to be cloaked in Darwin's mystery.
Teaching and emotions in a nonformal educational setting
Authors: Taylor Edward W.
Published: December 2008

Emotions play a key role in teaching in nonformal educational settings. Developing an awareness of learner emotions and their relationship to nonformal learning experiences is an essential practice for the nonformal educator.
Illuminating Dark Plasmons of Silver Nanoantenna Rings to Enhance Exciton–Plasmon Interactions
Authors: Gong Hong‐Mei , Zhou Li , Su Xiong‐Rui , Xiao Si , Liu Shao‐Ding , Wang Qu‐Quan
Published: December 2008

The chemical growth of silver nanorings that possess singly twinned crystals and a circular cross section via a reductive reaction solution is reported. The wire and ring diameters of the synthesized nanorings are in the ranges 80–200 nm and 4.5–18.0 μm, respectively. By lighting up the multipolar dark plasmons with slanted illumination, the silver nanoring exhibits unique focused scattering and large local‐field enhancement. We also demonstrate strong exciton–plasmon interactions between a monolayer of CdSe/ZnS semiconductor quantum dots and a single silver antenna‐like nanoring (nanoantenna) at the “hot spots” located at the cross points of the incident plane and nanoring; the position of these spots are tunable by adjusting the incidence angle of illumination. The tunable plasmonic behavior of the silver nanorings could find applications as optical nanoantennae or plasmonic nanocavities.
Lack of correlation between degree of human plasma low density lipoprotein oxidation and its atherogenic potential
Authors: Tertov Vladimir V. , Kaplun Victor V. , Orekhov Alexander N.
Published: December 2008

We have recently found that adducts of lipids, particularly cholesterol, with apolipoprotein B (apoB) are stable markers of human plasma low density lipoprotein (LDL) oxidation [V.V. Tertov, V.V. Kaplun, S.N. Dvoryantsev and A.N. Orekhov, Biochem. Biophys. Res. Commun. 214 (1995), 608–613]. In this study we attempt to assess the relationship between the degree of plasma LDL oxidation, evaluated by the content of apoB‐bound cholesterol and the ability of LDL to induce cholesterol accumulation in cultured human aortic intima smooth muscle cells, i.e., LDL atherogenic potential. LDL samples of 32 out of 39 healthy subjects did not increase cholesterol content in cells cultured from grossly normal intima of human aorta. Most of LDL preparations isolated from coronary atherosclerosis patients with (34 out of 43) or without (35 out of 45) hypercholesterolemia stimulated intracellular cholesterol acumulation by 32–302%. The ability of human LDL to induce cholesterol accumulation in aortic smooth muscle cells did not correlate with the degree of in vivo LDL oxidation (r=0.10, n=127). These results suggest that atherogenicity of LDL circulating in human plasma does not depend on the degree of lipid peroxidation in LDL particles.
The effect of chronic treatment with NO donors during intimal thickening and fatty streak formation
Authors: De Meyer Guido R. Y. , Bult Hidde , Kockx Mark M. , Herman Arnold G.
Published: December 2008

Intimal thickening in arteries is considered as a site of predilection for atherosclerosis. We investigated whether oral application of the nitric oxide (NO) donors SPM‐5185 (N‐nitratopivaloyl‐S‐(N'‐acetylalanyl)‐cysteine ethylester, 10 mg/kg body weight/b.i.d.) and molsidomine (pro‐drug of 3‐morpholino‐sydnonimine (SIN‐1), 10 mg/kg body weight/day) can retard intimal thickening and changes in vascular reactivity induced by a silicone collar positioned around the carotid artery of rabbits. Intimal thickening was significantly inhibited by SPM‐5185 (cross‐sectional area 18 ± 6 vs. 44 ± 10× 10‐3 mm2; P< 0.05), but not by molsidomine (28 ± 6 vs. 35 ± 9× 10‐3 mm2), which is a donor of both NO and superoxide anions. In organ chamber studies collaring was associated with a decreased sensitivity to acetylcholine (ACh). SPM‐5185 evoked a tendency towards normalization of the pD2 of ACh in collared arteries.

We also investigated whether chronic nitric oxide (NO) treatment affected vascular reactivity and fatty streak development in the rabbit aorta. During 16 weeks rabbits recived 150 g/day of a standard diet, or diets with 0.3% cholesterol, with 0.02% molsidomine (10 mg/kg body weight/day) or with the combination. The NO donor enhanced the area of fatty streaks, without affecting hypercholesterolemia. Moreover, it desensitized the smooth muscle cells of the rabbit aorta to vasodilators acting via the cytoplasmic guanylate cyclase and suppressed the capacity of the endothelial cells to release NO in response to muscarinic receptor stimulation. This suggested that chronic exposure to large quantities of NO caused a negative feedback, with selective decreases of both the endothelial capacity to generate NO and the responsiveness to vasodilators operating via cyclic GMP.

In conclusion, we demonstrated that exogenous NO can decrease intimal hyperplasia in vivo. However, prolonged in vivo treatment with a donor of NO enhanced atherosclerosis in hypercholesterolemic rabbits.
The effects of insulin, transferrin and androgens on rat prostate explants in serum‐free organ culture
Authors: Nguyen‐Le X. K. , Briére N. , Corcos J.
Published: December 2008

A model previously developed in our laboratory to culture rat prostate explants in serum‐free chemically‐defined medium was used to evaluate the direct influence of potential regulators. The aim of the present work was to verify the effects of insulin (I) and transferrin (Tr), two hormones considered as essential in other serum‐free culture systems, and three androgenic hormones, since the prostate is known to be androgen‐dependent. Explants of rat prostate were cultured for five days in serum‐free Leibovitz's L‐15 medium (37°C, 95% air – 5% CO2). The addition of Tr (50 μg/ml) had no effect, but I (5 μg/ml) significantly increased DNA synthesis. This influence was amplified by combination of the two hormones. However, protein synthesis was only slightly stimulated. Testosterone (T) or androstanediol significantly increased DNA synthesis when compared to corresponding control values at five days. In combination with I plus Tr, each hormone showed potentiated effects, particularly T with a twofold increase over day 0 values. When dihydrotestosterone was added singly, the incorporation of 3H‐thymidine was stimulated by 300% over control values at five days, and by 100% over values in uncultured explants. This influence was maximal since it was not improved by I plus Tr. Protein synthesis was increased significantly by the triple combination. In addition, each androgen as well as the combination of I plus Tr had a positive influence on explant morphology. The above conditions optimize the present culture system and establish its usefulness as a valuable tool to study the direct influence of different effectors in prostate metabolism and to eventually identify putative cancer markers.
Energy transduction function of the quinone reactions in cytochrome bc complexes
Authors: Cramer William A. , Soriano Glenda M.
Published: December 2008

Cytochrome bc1, a multi‐subunit integral membrane protein complex found in mammalian mitochondria, plays a central role in the transfer of electrons and protons generated by the oxidation of ubiquinol. According to the classical chemiosmotic theory, quinones shuttle protons across the hydrophobic membrane bilayer with the net result of H+ transfer to the aqueous side and generation of an electrochemical proton gradient. Recently, high‐resolution structures of the mitochondrial bc1 complex showed quinone binding sites at one of the transmembrane helices of cytochrome b, and two potentially protonatable histidine residues on the Rieske iron‐sulfur protein. The modern biochemical refinements of the original chemiosmotic theory require electron and proton transfer from quinones to particular residues/redox centers of integral membrane proteins and subsequent transfer of H+ to the bulk aqueous phase outside the membrane.
Plasma ubiquinol‐10 as a marker for disease: Is the assay worthwhile?
Authors: Kontush Anatol , Schippling Sven , Spranger Torsten , Beisiegel Ulrike
Published: December 2008

Ubiquinol‐10 and ubiquinone‐10 were measured in plasma of patients with several pathologies known to be associated with increased oxidative stress. Plasma ubiquinol‐10, expressed as a percentage of total ubiquinol‐10 + ubiquinone‐10, was found to be significantly lower in hyperlipidaemic patients and in patients with liver diseases than in age‐matched control subjects. In contrast, no decrease in ubiquinol‐10 was detected in plasma of patients with coronary heart disease and Alzheimer's disease. Except for ubiquinol‐10, no other lipophilic antioxidant was found to be decreased in patients with liver diseases. These data suggest that the level of ubiquinol‐10 in human plasma may serve as a marker for liver dysfunction, reflecting its diminished reduction by the liver rather than increased consumption by oxidants.
Sesamin and α‐tocopherol synergistically suppress lipid‐peroxide in rats fed a high docosahexaenoic acid diet
Authors: Yamashita K. , Kagaya M. , Higuti N. , Kiso Y.
Published: December 2008

Docosahexaenoic acid (DHA) is an essential nutrient for human health, but has extremely high oxidative susceptibility. We examined the suppressing effect of sesamin, a sesame seed lignan, on lipidperoxides in rats fed a low α‐tocopherol and high DHA containing diet. Groups of rats were fed four experimental diets: low α‐tocopherol (10 mg/kg diet) control diet, low α‐tocopherol + 0.2% sesamin diet, low α‐tocopherol + 0.5% DHA diet and low α‐tocopherol + 0.5% DHA + 0.2% sesamin diet. TBARS concentrations in plasma and liver were significantly increased by DHA, but were completely suppressed by sesamin. α‐Tocopherol concentrations in plasma and liver decreased by addition of DHA, but with sesamin recovered to the control level. The addition of DHA into the diets caused remarkable increases of DHA concentrations in plasma and liver lipids. Sesamin caused a significant increase of DHA concentrations in the triacylglycerol of plasma.
Cloning and expression of rat glucocorticoid‐receptor DNA‐binding domain
Authors: Okamoto Kazuki , Shibata Kiyotaka , Isohashi Fumihide
Published: December 2008

The inability to obtain sufficient quantities of purified glucocorticoid receptor (GR) causes difficulties in studying in vitro the interactions of GR with other proteins which contribute to the transcriptional activation of chromatin. Thus, we overexpressed the DNA‐binding domains (DBD) of GR in E. coli using glutathione S‐transferase (GST)‐fusion protein expression vector. The DBD‐GST protein (about 57 kDa), recovered in the soluble fraction, was purified by glutathione‐agarose column. However, during the chromatography, more than 90% of the DBD‐GST protein was cleaved into three species with molecular sizes of about 40, 35 and 30 kDa. The 40 kDa and 35 kDa proteins were immunostained with the anti‐GR antibody, and the 30 kDa protein was stained with anti‐GST antibody. Among these proteins, only the 57 kDa DBD‐GST protein bound to the GRE‐agarose. These data indicate that the properly folded 57 kDa protein has a DNA binding function and is resistant to intrinsic cleavage of the protein.
Gender influences the effect of perinatal copper deficiency on cerebellar PKC gamma content
Authors: Thomas Johnson W. , Prohaska Joseph R.
Published: December 2008

Change in cerebellar protein kinase C gamma (PKCγ) content caused by perinatal copper (Cu) deficiency was determined in 22‐day old rats. The offspring of dams with low Cu intake during gestation and lactation exhibited signs characteristic of Cu deficiency including anemia, greater than 90% reduction in liver Cu concentration, and undetectable serum ceruloplasmin. In addition, brain Cu concentrations were reduced 80%. No differences in the signs of Cu deficiency were observed between female and male offspring. However, cerebellar PKCγ content was reduced 54% (P<0.05, Tukey's test) in female offspring but only 18% (P>0.05) in male offspring. Following 6 weeks of Cu supplementation, brain Cu concentrations remained depressed in female and male rats that experienced perinatal Cu deficiency, but cerebellar PKCγ content was completely restored to control levels. Postnatal expression of PKCγ in the cerebellum coincides with and regulates cerebellar maturation. The results of the present study indicate perinatal Cu deficiency may impair cerebellar maturation to a greater extent in females than in males. However, it is not clear whether supression of PKCγ by perinatal Cu deficiency produces permanent neuropathology in the cerebellum because the effects were reversed by Cu supplementation.
Chemoprotection against cancer by induction of Phase 2 enzymes
Authors: Talalay Paul
Published: December 2008

Induction of Phase 2 enzymes is an effective and sufficient strategy for achieving protection against the toxic and neoplastic effects of many carcinogens. It is proposed that the concept of Phase 2 enzymes as being responsible only for the conjugation of functionalized xenobiotics with endogenous cellular ligands such as glutathione (glutathione S‐transferases) and glucuronic acid (UDP‐glucuronosyltransferases) be expanded to include proteins with the following common characteristics: (a) coordinate induction by a broad range of chemical agents that all have the capacity to react with sulfhydryl groups; (b) possible regulation by common promoter elements; and (c) catalysis of reactions that lead to comprehensive protection against electrophile and reactive oxygen toxicities, by a wide variety of mechanisms. These mechanisms include: conjugation with endogenous ligands, chemical modification of reactive features of molecules that can damage DNA and other macromolecules, and generation or augementation of cellular antioxidants. In addition to the above conjugating enzymes, a provisional and partial list of Phase 2 proteins might include: NAD(P)H:quinone reductase, epoxide hydrolase, dihydrodiol dehydrogenase, γ‐glutamylcysteine synthetase, heme oxygenase‐1, leukotriene B_4 dehydrogenase, aflatoxin B_1 dehydrogenase, and ferritin.
Prevention of the formation of mutagenic and/or carcinogenic heterocyclic amines by food factors
Authors: Kikugawa Kiyomi , Hiramoto Kazuyuki , Kato Tetsuta
Published: December 2008

Introduction of phenolic antioxidants, thiol compounds and reductones into the heated model system composed of glucose/glycine/creatinine was effective to scavenge the intermediary pyrazine cation radical and to reduce the mutagenicity due to imidazoquinoxaline heterocyclic amines. Addition of a reductone, ascorbate or erythorbate, at 0.3% to ground beef effectively reduced the mutagenicity of cooked hamburger. Mutagenicity of cooked hamburger was also decreased by addition of glucose at more than 0.7% to ground beef.
Generation of lipid peroxyl radicals from edible oils and their biological activities: A need for consideration for anti‐radical components and purification processing
Authors: Kanazawa Ayako , Sawa Tomohiro , Akaike Takaaki , Morimura Shigeru , Kida Kenji , Maeda Hiroshi
Published: December 2008

Lipid hydroperoxides (LOOH or oxidized oils) are known as unfavorable food components. Molecular details of the fate and mechanisms of LOOH to exert adverse effects in vivo are, however, little understood. In the present study, we demonstrated that LOOH generated alkylperoxyl radical (LOO.) after reaction with various heme compounds such as myoglobin, cytochrome c, hemin, hematin, etc., but little formation of other radical species was noticed such as L. or LO.. It was also shown that LOO. thus formed exhibits cytotoxicity and caused DNA damages including strand breakage and abasic site formation. This highly toxic LOO. is effectively scavenged by hot water extracts of vegetable (soup), flavonoids, polyphenols as well as tocopherols. Another important finding is that crude vegetable oils are rich in potent‐LOO. scavenging activity, which exhibits potent anti‐oxidant activity as well; whereas highly purified oils are scanty in such components and LOO. scavenging activity. These findings imply that a considerate processing in the refining of oils should be needed to retain such potent endogenous anti‐oxidative radical scavenging‐components.
A model for Sec incorporation with the regions upstream of the UGA Sec codon to play a key role
Authors: Goto Chiharu , Osaka Takashi , Mizutani Takaharu
Published: December 2008

For eukaryotic selenoprotein mRNAs, it has been proposed that the SECIS element in the 3′‐UTR is required for recognition of UGA as a Sec codon. Some proteins which bind to SECIS (SBP) have been reported. However, it is not clear how the SECIS element in the 3′‐UTR can mediate Sec insertion far at the in‐frame UGA Sec codons. The idea that there must be a signal near the UGA Sec codon is still being considered. Therefore, we searched for a protein which binds to an RNA sequence surrounding the UGA Sec codon on human GPx mRNA. We found a protein, prepared from bovine brain microsomes, which strongly bound to the RNA fragment upstream of the UGA Sec codon but not to the RNA sequence downstream of the UGA codon. This protein also bound to the SECIS sequence in the 3′‐UTR of human GPx, and this binding to SECIS was competed with the RNA fragment upstream of the UGA Sec codon. We also obtained the similar results with the RNA fragments of type I iodothyronine 5′‐deiodinase (5′DI) mRNAs. Comparison of such RNA fragments with SECIS fragments revealed similarities in the region upstream of the in‐frame UGA Sec codon of several Se‐protein mRNAs. The study thus favoures a novel model of Sec incorporation at the UGA Sec codon that involves the regions upstream of the UGA codon of mRNAs of mammalian selenoproteins. This model explains that the stem‐loop structure covering the UGA codon is recognized by SBP and how the UGA Sec codon escapes from attack by eRF.
An extended Escherichia coli “Selenocysteine Insertion Sequence” (SECIS) as a multifunctional RNA structure
Authors: Engelberg‐Kulka Hanna , Liu Zesheng , Li Chuang , Reches Myriam
Published: December 2008

The genetic code, once thought to be rigid, has been found to permit several alternatives in its reading. Interesting alternative relates to the function of the UGA codon. Usually, it acts as a stop codon, but it can also direct the incorporation of the amino acid selenocysteine into a polypeptide. UGA‐directed selenocysteine incorporation requires a cis‐acting mRNA element called the “selenocysteine insertion sequence” (SECIS) that can form a stem‐loop RNA structure. Here we discuss our investigation on the E. coli SECIS. This includes the follows: 1) The nature of the minimal E. coli SECIS. We found that in E. coli only the upper‐stem and loop of 17 nucleotides of the SECIS is necessary for selenocysteine incorporation on the condition that it is located in the proper distance from the UGA [34]; 2) The upper stem and loop structure carries a bulged U residue that is required for selenocysteine incorporation [34] because of its interaction with SelB; and 3) We described an extended fdhF SECIS that includes the information for an additional function: The prevention of UGA readthrough under conditions of selenium deficiency [35]. This information is contained in a short mRNA region consisting of a single C residue adjacent to the UGA on its downstream side, and an additional segment consisting of the six nucleotides immediately upstream from it. These two regions act independently and additively and probably through different mechanisms. The single C residue acts as itself; the upstream region acts at the level of the two amino acids, arginine and valine, for which it codes. These two codons at the 5′ side of the UGA correspond to the ribosomal E and P sites. Finally, we present a model for the E. coli fdhF SECIS as a multifunctional RNA structure containing three functional elements. Depending on the availability of selenium the SECIS enables one of two alternatives for the translational machinery: Either selenocysteine incorporation into a polypeptide or termination of the polypeptide chain.
Plasma selenium in specific and non‐specific forms
Authors: Burk Raymond F. , Hill Kristina E. , Motley Amy K.
Published: December 2008

Selenium is present in plasma and tissues in specific and non‐specific forms. The experiments reported here were carried out to clarify some factors that affect these forms of the element in plasma. A selenium‐replete human subject was given 400 μg of selenium daily for 28 days as selenomethionine and, in a separate experiment, as selenate. The selenomethionine raised plasma and albumin selenium concentrations. Selenate did neither. The molar ratio of methionine to selenium in albumin was approximately 8000 under basal and selenate‐supplemented conditions but 2800 after selenomethionine supplementation. This demonstrates that selenium from selenomethionine, but not selenium from selenate, can be incorporated into albumin, presumably as selenomethionine in the methionine pool. Selenocysteine incorporation into albumin was studied in rats using 75Se‐selenocysteine. No evidence was obtained for incorporation of 75Se into albumin after exogenous administration or endogenous synthesis of 75Se‐selenocysteine. Thus, selenocysteine does not appear to be incorporated non‐specifically into proteins as is selenomethionine. These findings are in support of selenomethionine being a non‐specific form of selenium that is metabolized as a constituent of the methionine pool and is unaffected by specific selenium metabolic processes. No evidence was found for non‐specific incorporation of selenium into plasma proteins when it was administered as selenate or as selenocysteine. These forms of the element appear to be metabolized by specific selenium metabolic processes.
Coenzyme Q differentially modulates phospholipid hydroperoxide glutathione peroxidase gene expression and free radicals production in malignant and non‐malignant prostate cells
Authors: Quiles J. L. , Farquharson A. J. , Ramírez‐Tortosa M. C. , Grant I. , Milne L. , Huertas J. R. , Battino M. , Mataix J. , Wahle K. W. J.
Published: December 2008

The aim of this study was to investigate the role of coenzyme Q on the mRNA abundance of PHGPx and the reactive oxygen species (ROS) production in two different cell lines from human prostate, a line of non cancer cells (PNT2) and a line of cancer cells (PC3). Results showed that malignant cells markedly differ in their response to coenzyme Q compared to non‐malignant cells, with no changes in PHGPx expression and greater ROS production. Furthermore coenzyme Q supplementation significantly lowered cell growth of the PC3 cancer line without affecting the PNT2. If these results are confirmed with additional experiments, it could represent a novel and interesting approach on the biomedical use of coenzyme Q10 in cancer therapy.
ADP‐ and oligomycin‐sensitive redox behavior of F0 b thiol in ATPsynthase depends on neighbored primary structure: Investigations using 14‐C‐labeled alpha lipoic acid
Authors: Dünschede Fritz , Zwicker Klaus , Ackermann Hanns , Zimmer Guido
Published: December 2008

Purified ATPsynthase of bovine heart mitochondria has been analyzed for its mobility and reactivity of oligomycin‐sensitive sulfhydryl regions in presence of the substrate ADP and oligomycin. Labeling of thiol groups at the hydrophobic F0 region of the ATPsynthase was increased in the enzyme initially treated with SDS, N‐ethylmaleimide and dithiothreitol (modified enzyme). After dialysis or gel permeation the ATPsynthase was treated with [14C] alpha lipoic acid at a molar ratio of 35‐85/1 (lipoic acid/ATPsynthase) corresponding to 4‐8.6 nmol/mg protein. Under these conditions, ATPase activity of the native enzyme was significantly decreased. After preincubation with ADP, PAGE of the native, [14C] labeled enzyme revealed an increase of radioactivity at a region of 25 kDa deduced to Cys 197 of subunit b. In the modified enzyme the increase in radioactivity was found at 10 kDa. In this context, the sequence Lys‐Cys‐Ile around Cys 197 of subunit b suggests excessive reactivity of this thiol, as well as ready reversibility by ‐SH‐S‐S‐ interchange. Therefore, previously observed reaction by thiol reagents and antioxidants from outside the mitochondrion can be interpreted with Cys 197 of F0 b. It accounts for sulfhydryl unmasked by binding of ADP at F1.
Manganese alters mitochodrial integrity in the hearts of swine marginally deficient in magnesium
Authors: Miller Kevin B. , Newman Samuel M. , Caton Joel S. , Finley John W.
Published: December 2008

It was previously reported that pigs marginally deficient in magnesium (Mg) and fed diets high in manganese (Mn) died suddenly with signs of sudden cardiac death. Manganese, which has properties similar to Mg, may exacerbate Mg‐deficiency and be accumulated by mitochondria resulting in ultrastructural damage. The objective of this study was to determine whether deaths of the type previously observed were mediated by adverse interactions of Mn and Mg resulting in ultrastructural damage to the myocardium, alterations in electrocardiographic recordings and tissue retention of Mn, Mg and calcium (Ca). Forty‐eight pigs were fed one of six diets in a 2 × 3 factorial arrangement of Mg (100 or 1000 mg Mg/kg) and Mn (5, 50 or 500 mg Mn/kg) for 8 weeks. Left ventricle muscle samples were collected for examination by transmission electron microscopy. No differences in heart muscle ultrastructure were observed between pigs fed low and adequate dietary Mg. However, marked myocardial necrosis and mitochondrial swelling were observed in pigs fed high dietary Mn when combined with low Mg. Feeding low dietary Mg elevated minimum (P < 0.01), maximum (P < 0.05) and average (P < 0.001) heart rates. Low dietary Mg resulted in a 55% probability of a ventricular beat being recorded (P = 0.05) and lower Mg (P < 0.02) and Ca (P < 0.04) contents in heart atria and ventricles. These results suggest that high Mn, when fed in combination with low Mg, disrupts mitochondrial ultrastructure and is associated with the sudden deaths previously reported.
Redox regulation of ascorbic acid transport: Role of transporter and intracellular sulfhydryls
Authors: May James M. , Qu Zhi‐chao
Published: December 2008

Ascorbic acid is one of the most sensitive cellular defenses against oxidant damage. However, it requires a sodium‐ and energy‐dependent transporter to enter cells against a concentration gradient. To test the hypothesis that ascorbate transport is sensitive to redox stress, we studied changes in transport of the vitamin in response to sulfhydryl modification of the protein and to GSH depletion in cultured endothelial cells. Transport of ascorbic acid, measured as the uptake of radiolabeled ascorbate, was inhibited by the membrane‐impermeant sulfhydryl reagents thorin, p‐chloromercuribenzene sulfonic acid, and 5,5′‐dithiobis‐(2‐nitrobenzoic acid) in a dose‐dependent manner without significant depletion of intracellular GSH. Sulfhydryl reagents capable of penetrating the plasma membrane, including phenylarsine oxide, p‐chloromercuribenzoic acid, and N‐ethylmaleimide, inhibited transport and lowered cellular GSH. Diamide, which induces disulfide formation, increased ascorbate transport over a narrow concentration range under conditions in which GSH was not depleted. On the other hand, specific depletion of intracellular GSH by several different mechanisms did inhibit transport. Together, these results suggest that the ascorbate transporter is sensitive to redox modulation. This relates in part to sulfhydryl groups exposed on the exofacial ascorbate transporter, and to sulfhydryl groups that are sensitive to changes in the redox state of intracellular GSH.
Effect of high phosphorus diet on phosphorus metabolism in parathyroidectomized rats
Authors: Katsumata Shin‐Ichi , Masuyama Ritsuko , Koshihara Moyuru , Matsuzaki Hiroshi , Uehara Mariko , Suzuki Kazuharu
Published: December 2008

To determine the parathyroid hormone (PTH) action on kidney and bone by high phosphorus (P) diet, this study investigated PTH/PTH‐related peptide (PTHrP) receptor mRNA expression in 6‐week‐old parathyroidectomized (PTX) rats received constant amount of PTH. To maintain serum PTH levels equally to sham operated rats, PTX rats were constantly exposed to rPTH (1–34) and fed a control diet (0.3% P) and a high P diet (1.2% P) for 7 days, respectively. There were no significant differences in serum PTH (1–34) concentration in rats fed the control diet. In sham groups, serum PTH concentrations, both (1–84) and (1–34) fragments, were increased in rats fed the high P diet than in rats fed the control diet. Urinary excretions of P and C‐terminal telopeptides of type I collagen were significantly increased in both PTX and sham rats by the high P diet. PTH/PTHrP receptor mRNA expression in kidney and femur was not changed in both PTX and sham rats by the high P diet. In conclusion, high P diet did not change PTH action in PTX rats and increased urinary excretion of P and bone resorption regardless of PTH action.
Cancer prevention by antioxidants
Authors: Nishino Hoyoku , Tokuda Harukuni , Satomi Yoshiko , Masuda Mitsuharu , Osaka Yasuhito , Yogosawa Shingo , Wada Saeri , Mou Xiao Yang , Takayasu Junko , Murakoshi Michiaki , Jinnno Kenji , Yano Masamichi
Published: December 2008

Various antioxidants in foods, such as phenolic compounds and carotenoids, were proven to have anticarcinogenic activity.

In the case of carotenoids, the mixture of them was found to be very effective. In fact, the development of hepatoma in the high risk group of liver cancer, was significantly suppressed by the treatment with natural carotenoids mixture.

The role of nitric oxide (NO) in carcinogenesis has been pointed out, since large quantity of NO has been detected in cancer tissues, and the expression of inducible NO synthase (iNOS) was found to correlate with tumor growth and metastasis. Recently, we found that NO possessed tumor initiating activity in mouse skin carcinogenesis. It has been suggested that some parts of pathological effects induced by NO may depend on peroxynitrite, an active metabolite of NO. Thus, we accessed the tumor initiating activity of peroxynitrite, and found that treatment with peroxynitrite (initiator) plus TPA (promoter) resulted in the formation of skin tumors. Under this experimental condition, it has been proven that natural antioxidants, such as curcumin and nobiletin, showed anti‐tumor initiating effect. In the case of nobiletin, suppressive effect on iNOS induction has also been demonstrated. It is of interest that suppression of iNOS induction was also observed in phytoene synthase transgenic mouse. After administration of glycerol (a lung tumor promoter), lower induction of iNOS gene was observed in lung of the phytoene producing mice, comparing with that of control mice.

Combinational use of various kinds of antioxidants distributed in foods, e.g., mixture of carotenoids and flavonoids, seems to be effective methods for cancer prevention.
18O‐Labeled lipid hydroperoxides and HPLC coupled to mass spectrometry as valuable tools for studying the generation of singlet oxygen in biological system
Authors: Miyamoto Sayuri , Martinez Glaucia R. , Martins Ana Paula B. , Medeiros Marisa H. G. , Mascio Paolo Di
Published: December 2008

Decomposition of lipid hydroperoxides (LOOH) is known to generate toxic products capable to induce tissue injury. We have recently confirmed that decomposition of LOOH into peroxyl radicals is a potential source of singlet oxygen (1O2) in biological system. Using 18O‐labeled linoleic acid hydroperoxide (LA18O18OH) in the presence of Ce4+ or Fe+2, we observed the formation of 18O‐labeled 1O2 (18[1O2]) by chemical trapping of 1O2 with 9,10‐diphenylanthracene (DPA) and detecting the corresponding 18O‐labeled DPA endoperoxide (DPA18O18O) by HPLC coupled to tandem mass spectrometry (HPLC‐MS/MS). 18O‐Labeled alcohol and ketone were also detected providing further evidence for the generation of 1O2by the Russell mechanism. Similarly the reaction of LA18O18OH with peroxynitrite also generated18[1O2].In conclusion, these results indicates that the use of 18O‐labeled LOOH associated with HPLC‐MS/MS can be an useful tool to clarify mechanistic features involved in the reaction of LOOH in biological media.
Liquid‐liquid extraction of α‐lactalbumin using reverse micellar organic solvent
Authors: Naoe Kazumitsu , Noda Kazuki , Konishi Taiji , Kawagoe Mikio , Imai Masanao
Published: December 2008

The liquid‐liquid extraction of α‐lactalbumin based on reverse micellar organic solvents was investigated. Forward extraction of the protein in the reverse micellar organic phase from aqueous feed solutions was strongly dependent on the initial pH of the feed solution and the complete forward extraction of 0.03 mM α‐lactalbumin was successfully achieved at pH 6.0. The forward extraction percentage steeply decreased with increasing KCl concentration, while in the NaCl system the forward extraction was independent on the salt concentration below 1 M. From the circular dichroic measurement, higher order structure of the recovered α‐lactalbumin through the extraction process was well preserved.
Induction of apoptosis in a human lymphoma cell line by hydrophobic peptide fraction separated from anchovy sauce
Authors: Lee Young Gon , Lee Ki Won , Kim Ji Yeon , Kim Kyoung Heon , Lee Hyong Joo
Published: December 2008

Peptide fractions showing anticancer activity were isolated from anchovy sauce, and their abilities to induce apoptosis in a human lymphoma cell (U937) were determined by biochemical and flow cytometric methods. The butanol extract (fraction Aob) from the desalted hydrophobic peptide fraction (Ao) separated from anchovy sauce by HP‐20 adsorption chromatography was found to possess strong antiproliferative activity against U937 by inducing apoptosis. Treatment of U937 with Aob resulted in sub‐G1 peak representing apoptosis in the cell cycle analysis, and apoptotic DNA fragmentation. Antiproliferative activity of the peptide fraction further purified successively by silica gel chromatography, TLC, and reversed‐phase HPLC increased proportionally with the purification fold. The peptide fraction having antiproliferative activity was found to be composed of Ala and Phe, and its molecular weight was estimated to be 440.9 Da.
Caseinophosphopeptides and their cell modulating potential
Authors: Hartmann R. , Meisel H.
Published: December 2008

In the context of the EU research project FAIR‐CT 98–3077, studies were carried out to investigate caseinophosphopeptides (CPP) as potential ingredients for functional food and pharmaceutical applications.

CPP preparations were produced by enrichment of CPP from hydrolytic casein digests. Enzyme preparations used for hydrolysis were PTN 3.0 S, Alcalase, Bioprotease P conc, Proteinase DS. Cytochemical studies were carried out to examine the cytotoxic potential or cell modulating activities of CPP using human cancer cell lines (HL‐60, Caco‐2) and non‐malignant polymorphonuclear leukocytes (PML) from oral cavity. PML cells isolated by magnetic cell sorting using CD‐15‐antibody‐labelled paramagnetic beads were used for the first time for testing food‐derived peptides. Cell activity was measured by formazan dye formation. Effects on enterocytic differentiation properties of Caco‐2 cells were examined by transepithelial membrane resistance of Caco‐2 cell monolayers and brush border associated alkaline phosphatase activity.

In conclusion, (1) no deleterious cytochemical consequences (apoptotic, antiproliferative or general cytotoxic effects) were observed on presenting a range of CPP preparations to various human cell systems, indicating that these compounds can be rated harmless at a cellular level, (2) stimulation of IgG‐secretion into culture supernatant of PBL points to possible immunoenhancing properties of CPP preparations.
Transbilayer distribution of aminophospholipids and the oxidative stability of their component polyunsaturated fatty acids
Authors: Kubo Kazuhiro , Sekine Seiji , Saito Morio
Published: December 2008

We examined the relationship between the transbilayer distribution of aminophospholipids, such as phosphatidylethanolamine (PE), PE plasmalogen and phosphatidylserine, and the oxidative stability of polyunsaturated fatty acids (PUFAs) in the aminophospholipids. To modulate the transbilayer distribution of aminophospholipid in liposomes, we used phosphatidylcholine (PC) with two types of acyl chain region: dipalmitoyl (PC16:0) or dioleoyl (PC18:1). In the smaller‐sized liposomes, the proportions of aminophospholipid in the liposomal external layer were significantly higher in liposomes containing PC18:1 than in those containing PC16:0. Additionally, aminophospholipids in the external layer of smaller‐sized liposomes were able to protect their component PUFAs from 2,2'‐azobis(2‐amidinopropane)dihydrochloride‐mediated lipid peroxidation.
Formation of N‐(hexanoyl)ethanolamine, a novel phosphatidylethanolamine adduct, during the oxidation of erythrocyte membrane and low‐density lipoprotein
Authors: Tsuji Kentaro , Kawai Yoshichika , Kato Yoji , Osawa Toshihiko
Published: December 2008

The primary amino groups of biomolecules such as aminophospholipids, as well as proteins, are the potential targets of covalent modifications by lipid peroxidation products; however, little attention has been paid to the modification of aminophospholipids such as phosphatidylethanolamine (PE). The purpose of this study is to characterize the formation of a novel modified phospholipid, N‐(hexanoyl)phosphatidylethanolamine (HEPE), in the reaction of PE with lipid hydroperoxides using mass spectrometric analyses. Upon reaction of egg PE with 13‐hydroperoxyoctadecadienoic acid or other oxidized polyunsaturated fatty acids followed by phospholipase D‐mediated hydrolysis, the formation of N‐(hexanoyl)ethanolamine (HEEA), a head group of HEPE, was confirmed by isotope dilution liquid chromatography/tandem mass spectrometry. Moreover, increasing HEEA was detected in the hydrolysates of oxidized erythrocyte ghosts and low‐density lipoprotein with their increasing lipid peroxidation levels. Collectively, these results suggest that the N‐hexanoylated product of phospholipid, HEPE, can be generated during lipid peroxidation and may serve as one mechanism for the covalent modification of aminophospholipids in vivo.
Anthocyan does not suppress transformation of aryl hydrocarbon receptor induced by dioxin
Authors: Mukai Rie , Fukuda Itsuko , Nishiumi Shin , Hosokawa Keizo , Kanazawa Kazuki , Ashida Hitoshi
Published: December 2008

Dioxins cause a variety of toxic effects through transformation of a cytosolic aryl hydrocarbon receptor (AhR). We have previously demonstrated that certain natural flavones and flavonols at the dietary levels suppress AhR transformation. In this study, we investigated whether 5 anthocyanidins, 15 anthocyanins, and protocatechuic acid suppress AhR transformation in mouse hepatoma Hepa‐1c1c7 cells. All the compounds tested here at 5 μM unexpectedly failed to suppress the transformation induced by 0.1 nM TCDD, indicating that anthocyan does not have a potential to prevent dioxin toxicity.
Colosigmoid junction: Morphohistologic, morphometric, and endoscopic study with identification of colosigmoid canal with sphincter
Authors: Shafik Ali A. , Asaad Soheir , Loka Mona M. , Wahdan Mohamed , Shafik Ahmed
Published: December 2008

To study the anatomical structure of the colosigmoid junction, 15 cadaveric specimens were studied morphologically, another 15 histologically, and a morphometric study was done in 10 specimens. Specimens consisted of the descending colon, sigmoid colon, and the colosigmoid junction. Histologic specimens were stained with hematoxylin and eosin and Masson's trichrome stain. Morphometric studies used an image analysis system. The colosigmoid junction was investigated endoscopically in 18 healthy volunteers. A narrow segment having a mean length of 5.2 ± 1.1 cm was identified both externally and internally between the descending and sigmoid colon. We called this segment the colosigmoid canal. Mucosal folds were found crowded in the colosigmoid canal, the lower end of which formed a nipple and was surrounded by a fornix. Histologically, the colosigmoid canal mucosa showed multiple folds. Its circular muscle was thicker than that of the descending or the sigmoid colon and confirmed morphometrically. The longitudinal muscle was thicker in only 4 of 10 specimens. Both the narrowing and the mucosal crowding were verified endoscopically. The colosigmoid junction is the narrow segment between the descending and the sigmoid colon. Histologic, morphometric and endoscopic studies indicated the presence of a sphincter in the colosigmoid canal. A colosigmoid sphincter is suggested to control the passage of colonic contents from the descending colon to the colosigmoid canal as well as to prevent reflux of sigmoid contents into the descending colon. Clin. Anat. 22:243–249, 2009. © 2008 Wiley‐Liss, Inc.
Institutional efforts to address disadvantaged students: An “up‐so‐down” view
Authors: Levin John S.
Published: December 2008

Practitioners at individual community colleges and in‐state agencies recognize the struggles of disadvantaged students, yet their combined efforts do not overcome the policies and practices that are contrary to advancing and aiding large student populations.