bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vitamin E and hepatotoxic agents
Authors: Bunyan J. , Cawthorne M. A. , Diplock A. T. , Green J. 
Published: May 2005

1. Fatty liver was induced in 4-month-old male rats by oral dosing with ethanol. The marked increase in liver fat was not accompanied by a rise in lipid peroxides.2. Homogenates were prepared from the livers of vitamin E-deficient rats and incubated with ethanol. In the concentration range of 10–50 μl/3 ml, ethanol increased the production of malondialdehyde. Methanol, which is not a hepatotoxin, showed a similar effect at 10–35 μl/3 ml homogenate. These findings indicate that the pro-oxidative effect of alcohols in vitro is unrelated to their hepatotoxic action in vivo.3. Fatty liver was induced in 3.g-month-old, vitamin E-deficient male rats by oral dosingwith ethanol. The effect of pretreatment with vitamin E and N,N'-diphenyl-p-phenylenediamine (DPPD) was studied. D-α-Tocopheryl acetate, given as three doses of 350 mg/kg at 48, 24 and 2 h before the ethanol, failed to decrease the fat accumulation and seemed rather to increase the fat content of the liver. DPPD, given as three doses of 600 mg'kg at similar intervals before the ethanol dose, reduced the fat content of the liver almost to normal.4. Weanling rats of both sexes were given a vitamin E-deficient diet containing 1% orotic acid for 15 days to induce fatty liver. Dietary supplements of D-a-tocopheryl acetate (500 ppm), selenium (I ppm) or DPPD (100 ppm) did not reduce the lipid accumulation. Lipid peroxides and malondialdehyde levels were lower in the livers of animals treated with orotic acid than in controls, regardless of the presence of vitamin E.j. Liver necrosis was produced in 9-week-old female vitamin E-deficient rats by the intra-peritoneal injection of zoo mg thioacetamide. Promethazine hydrochloride (Phenergan), given intraperitoneally as two doses (25 mg/kg at the same time as the thioacetamide and 12.5 mg/kg 6 h later), markedly reduced the necrosis. D-α-Tocopheryl acetate, given as two oral doses of 1000mg/kg 48 h and 24 h before the thioacetamide, tended to exacerbate the necrosis.6. The results are discussed in relation to the question of lipid peroxidation as a cause of hepatotoxicity.
Prediction of carcass fat from body measurements made on live rats differing in age, sex and strain
Authors: Marshall Mary W. , Smith Barbara P. , Munson Arvid W. , Lahmanhn Richard P. 
Published: May 2005

1. Individual body fat and body measurements such as lengths, girths and selected skinfold thicknesses were determined in our laboratory strain (BHE), a highly inbred strain (IN) of BHE rats and in a strain of Wistar rats. Measurements were made on unconscious rats in less than 5 min per rat just before autopsy; body fat content was determined in individual rats of both sexes at 50, 100 and 300 days of age.2. Among the strains, mean total body fat was highest in BHE rats at each age; IN rats of similar average body size were leanest. Statistically significant differences in body fat among the strains were due primarily to differences among the male rats at 300 days. Total protein and skeletal mass increased with increases in age and body size, as did body fat in rats after maturity. IN rats had the largest fat-free weights. Although significant age differences in body fat and body measurements occurred, they were in part dependent upon changes in body- weight, sex and strain of the animals. Female rats had more fat per unit body-weight than males at each age studied. Females, though fatter than males, had smaller skinfold thicknesses, indi- cating that female fat increases are primarily in visceral fat.3. Large variation in fat among individuals within strains of the same body-weight and age suggests a genetic influence in fat potential in rats not associated with age or body-weight.4. Results from multiple regression analyses showed differences among adjusted means and partial regression coefficients due to strain and sex of the animals. Although final body-weight was the predictor common to all equations, body length, abdominal girth and subscapular skinfold were common to all but one set of equations. Chest girth, tibia length, triceps and abdominal skinfolds decreased in frequency of appearance in that order. Some of the measurements were more effective predictors at one age than at another. It was clearly necessary to take into account body dimensions other than weight to obtain an optimal prediction of body fat.5. Differences in characteristics of the rats support the concept of genetic influences in fat deposition in individuals and indicate the complex nature of these influences.
Studies on the oesophageal groove reflex in sheep and on the potential use of the groove to prevent the fermentation of food in the rumen
Authors: Ørskov E. R. , Benzin D. 
Published: May 2005

1. Fluids were given by mouth in various ways to young sheep. The extent to which closure of the oesophageal groove operated to direct the fluid to the abomasum was assessed by radiography.2. Salt solutions and milk given as a drench did not produce complete closure of the groove. However, when the animals were accustomed to sucking from a teat before weaning, any liquid suspension and also water, sucked from a bottle, passed entirely to the abomasum even in 12-month-old sheep.3. This technique may be useful when it is desirable to cause protein or other nutrients to by-pass fermentation in the rumen.
Metabolism of urea in late pregnancy and the possible contribution of amino acid carbon to glucose synthesis in sheep
Authors: Nolan J. V. , Leng R. A. 
Published: May 2005

1. Metabolism of urea in non-pregnant and pregnant sheep (1–25 d from term) has been examined. Injections of [14C]urea were used to estimate urea entry rate, urea pool size and urea space in sheep given 1000 g of a diet of equal parts of crushed oats and chaffed lucerne hay (daya) and in the same sheep 4 d after the ration had been reduced to 250 g (dayb).2. On both experimental days (aandb), mean pool size was greater (14% on day α, 29% on dayb) and urea space was greater (54% on day α, 24% on dayb) in pregnant animals than in non-pregnant animals; mean plasma urea concentrations were lower (35%) in the pregnant animals on day a but were not significantly different on dayb.3. The entry rate of urea was similar in all the animals on daya, but was significantly higher (34%) in pregnant than in non-pregnant animals on dayb. There was a significant decrease in urea entry rate in both pregnant (33%) and non-pregnant (86%) animals on dayb.4. The rate of excretion of urea was lower (26% on daya, 35% on dayb) in pregnant animals, indicating a higher (31% on day α, 40% on dayb) rate of degradation of urea in the digestive tract of pregnant as compared with non-pregnant sheep.5. Measurements of urea entry rate have been used to calculate the upper limit of amino acid deamination in pregnant and non-pregnant sheep, and this has been used as an indication of the potential availability of amino acid carbon for glucose synthesis. It is suggested that, at a maximum, amino acids may have contributed the carbon required for 63 g/d and 52 g/d of glucose on daysaandbrespectively.
Blood urea measurement as a technique for assessing protein quality
Authors: Eggum Bjørn O. 
Published: May 2005

1. Three factors were investigated which influence blood urea content, namely the protein content in the diet, the time after feeding and the protein quality of the diet.2. To investigate the relationship between the protein content in the diet and the blood urea content, seventeen experiments with rats given increasing amounts of protein in the diet were carried out. The experimental results show that there is a positive correlation (r = 0.95) between the protein content in the diet and the blood urea content.3. For investigation of the influence of time after feeding on the urea content in the blood, a pig was used having a catheter in the portal vein for blood sampling at intervals. The results from this experiment showed that the blood urea content increases for the first 3–4 h after feeding and thereafter reaches a plateau.4. To use blood urea measurement as a technique for assessing protein quality it is necessary to work under standardized conditions, especially in regard to the two factors just discussed.5. Forty-two feeding-stuffs of widely differing quality were used in nitrogen balance trials with rats. The results showed that there is an inverse relation between the blood urea content and the biological value of the diet which is sufficiently accurate (coefficient of variation = 53%) to provide ausefulmethod for the predictionof protein quality from measurement of urea levels.
Evaluation of modified [35S]methionine and [35S]casein preparations as supplements for sheep
Authors: Downes A. M. , Reis P. J. , Sharry L. F. , Tunks D. A. 
Published: May 2005

1. Doses of L-[35S]methionine (2 g) and [35S]casein (20 g) were given to sheep in the diet or via the abomasum, and the patterns of 35S-labelling in blood, wool and excreta were studied during the 7 d following administration of the dose.2. Doses given via the abomasum resulted in substantial labelling of the plasma proteins and wool; only small amounts of the dose were recovered in the urine and faeces. In contrast, doses given in the diet resulted in much less labelling of plasma proteins and wool and ingreater losses in excreta. These results provide the basis of a rapid system for testing the effectiveness of various methods of protecting methionine and casein from degradation in the rumen.3. From the patterns obtained with N-formyl-DL-[35S]methionine and [35S]polymethionine (mol. wt 7–8 × 104) it appears unlikely that these compounds would stimulate wool growth if given as dietary supplements.4. [35S]Casein which had been treated with an 8 % aqueous solution of formaldehyde gave results which showed that the casein had been protected from destruction in the rumen without markedly reducing its subsequent digestibility. Treatment of [35S]casein with excess, formalde-hyde (a 40 % aqueous solution) gave a product which was completely indigestible.5. It is concluded that the radioisotope technique could be applied to other [35S]amino acids or their derivatives and to other [35S]proteins, and should also be applicable to larger ruminants such as cattle.
Nitrogen retention in rats fed on diets enriched with arginine and glycine
Authors: Sitren H. S. , Fisher H. 
Published: May 2005

1. Nitrogen retention was measured in adult rats (250–350 g) subjected to the trauma of hind-leg fracture and given diets with or without arginine plus glycine supplementation. Observations were also recorded on excretion of creatine, creatinine, allantoin, and orotic acid. Liver and skeletal muscle transaminase activities were also determined.2. When traumatized rats weighing approximately 250 g were given a diet with 200 g casein/ kg, supplemented with 20 g arginine and 10 g glycine/kg (EC diet) or a casein diet made isonitrogenous with the EC diet by addition of aspartic acid (C diet), a 60–70% increase in N retention was observed for the first 5 d post-injury for animals consuming the EC diet. A soyabean (S) diet, isonitrogenous to the diet containing 20% casein, supplemented with arginine and glycine was as effective as the EC diet in promoting significantly better N retention of traumatized rats (350 g) in comparison to rats given the C diet.3. When the dietary casein content was reduced to 100 g/kg, supplements of 10 g arginine and 5 g glycine or 20 g arginine and 10 g glycine/kg did not improve N retention. It is suggested that both protein quality and protein quantity are important following injury.4. An increased excretion of creatine was observed in traumatized rats given the high-protein diets supplemented with arginine and glycine. No consistent changes were noted for urine creatinine.5. Urine allantoin levels remained stable after leg-fracture in rats consuming either the C or EC diets. Differences in the levels of urine orotic acid were found during both the pre- and post-injury periods in rats given the C, EC or S diets.6. The mechanisms responsible for the improved N retention of traumatized rats consuming the high-protein diets with supplements of arginine and glycine may be related to the role of arginine both as a constituent of muscle tissue and as an intermediate in the urea cycle.7. In traumatized rats fed the C or EC diets, liver transaminase activity increased whereas the transaminase activity in skeletal muscle decreased. These results support the recent concept that the increased excretion of N following injury arises from diminished reutilization of amino acids by muscle tissue without an acute increase in the rate of muscle catabolism.
Major Signaling Pathways Modulate Arabidopsis Glucosinolate Accumulation and Response to Both Phloem-Feeding and Chewing Insects
Authors: Mewis Inga , Appel Heidi M. , Hom Amanda , Raina Ramesh , Schultz Jack C. 
Published: May 2005

Abstract
Plant responses to enemies are coordinated by several interacting signaling systems. Molecular and genetic studies with mutants and exogenous signal application suggest that jasmonate (JA)-, salicylate (SA)-, and ethylene (ET)-mediated pathways modulate expression of portions of the defense phenotype in Arabidopsis (Arabidopsis thaliana), but have not yet linked these observations directly with plant responses to insect attack. We compared the glucosinolate (GS) profiles of rosette leaves of 4-week-old mutant and transgenic Arabidopsis (Columbia) plants compromised in these three major signaling pathways, and characterized responses by those plants to feeding by two phloem-feeding aphids (generalist Myzus persicae and specialist Brevicoryne brassicae) and one generalist caterpillar species (Spodoptera exigua Hubner). Blocked JA signaling in coronatine-insensitive (coi1) and enhanced expression of SA-signaled disease resistance in hypersensitive response-like (hrl1) mutants reduced constitutive GS concentrations, while blocking SA signaling at the mediator protein npr1 mutant (NPR) increased them. There was no significant impact on constitutive GS contents of blocking ET signaling (at ET resistant [etr1]) or reducing SA concentrations (nahG transgene). We found increased GS accumulation in response to insect feeding, which required functional NPR1 and ETR1 but not COI1 or SA. Insect feeding caused increases primarily in short-chain aliphatic methylsulfinyl GS. By contrast, responses to exogenous JA, a frequent experimental surrogate for insect attack, were characterized by an increase in indolyl GS. Insect performance, measured as population increase or weight increase, was negatively related to GS levels, but we found evidence that other, ET-regulated factors may also be influential. Plant resistance to (consumption by) S. exigua was not related to insect growth because some plant chemistries inhibited growth while others inhibited feeding. These major signaling pathways modulate Arabidopsis GS accumulation and response to both phloem-feeding and chewing insects, often antagonistically; NPR appears to be central to these interactions. Our results indicate that exogenous signal application and plant consumption measures may not provide useful measures of plant responses to actual insect feeding.
Structural Complexity, Differential Response to Infection, and Tissue Specificity of Indolic and Phenylpropanoid Secondary Metabolism in Arabidopsis Roots
Authors: Bednarek Paweł , Schneider Bernd , Svatoš Aleš , Oldham Neil J. , Hahlbrock Klaus 
Published: May 2005

Abstract
Levels of indolic and phenylpropanoid secondary metabolites in Arabidopsis (Arabidopsis thaliana) leaves undergo rapid and drastic changes during pathogen defense, yet little is known about this process in roots. Using Arabidopsis wild-type and mutant root cultures as an experimental system, and the root-pathogenic oomycete, Pythium sylvaticum, for infections, we analyzed the aromatic metabolite profiles in soluble extracts from uninfected and infected roots, as well as from the surrounding medium. A total of 16 indolic, one heterocyclic, and three phenylpropanoid compounds were structurally identified by mass spectrometry and nuclear magnetic resonance analyses. Most of the indolics increased strongly upon infection, whereas the three phenylpropanoids decreased. Concomitant increases in both indolic and phenylpropanoid biosynthetic mRNAs suggested that phenylpropanoids other than those examined here in “soluble extracts” were coinduced with the indolics. These and previous results indicate that roots differ greatly from leaves with regard to the nature and relative abundance of all major soluble phenylpropanoid constituents. For indolics, by contrast, our data reveal far-reaching similarities between roots and leaves and, beyond this comparative aspect, provide an insight into this highly diversified yet under-explored metabolic realm. The data point to metabolic interconnections among the compounds identified and suggest a partial revision of the previously proposed camalexin pathway.
The AtRAD51C Gene Is Required for Normal Meiotic Chromosome Synapsis and Double-Stranded Break Repair in Arabidopsis
Authors: Li Wuxing , Yang Xiaohui , Lin Zhenguo , Timofejeva Ljudmilla , Xiao Rong , Makaroff Christopher A. , Ma Hong 
Published: May 2005

Abstract
Meiotic prophase I is a complex process involving homologous chromosome (homolog) pairing, synapsis, and recombination. The budding yeast (Saccharomyces cerevisiae) RAD51 gene is known to be important for recombination and DNA repair in the mitotic cell cycle. In addition, RAD51 is required for meiosis and its Arabidopsis (Arabidopsis thaliana) ortholog is important for normal meiotic homolog pairing, synapsis, and repair of double-stranded breaks. In vertebrate cell cultures, the RAD51 paralog RAD51C is also important for mitotic homologous recombination and maintenance of genome integrity. However, the function of RAD51C in meiosis is not well understood. Here we describe the identification and analysis of a mutation in the Arabidopsis RAD51C ortholog, AtRAD51C. Although the atrad51c-1 mutant has normal vegetative and flower development and has no detectable abnormality in mitosis, it is completely male and female sterile. During early meiosis, homologous chromosomes in atrad51c-1 fail to undergo synapsis and become severely fragmented. In addition, analysis of the atrad51c-1 atspo11-1 double mutant showed that fragmentation was nearly completely suppressed by the atspo11-1 mutation, indicating that the fragmentation largely represents a defect in processing double-stranded breaks generated by AtSPO11-1. Fluorescence in situ hybridization experiments suggest that homolog juxtaposition might also be abnormal in atrad51c-1 meiocytes. These results demonstrate that AtRAD51C is essential for normal meiosis and is probably required for homologous synapsis.
Arabidopsis Peroxisomal Citrate Synthase Is Required for Fatty Acid Respiration and Seed Germination
Authors: Pracharoenwattana Itsara , Cornah Johanna E. , Smith Steven M. 
Published: May 2005

AbstractWe tested the hypothesis that peroxisomal citrate synthase (CSY) is required for carbon transfer from peroxisomes to mitochondria during respiration of triacylglycerol in Arabidopsis thaliana seedlings. Two genes encoding peroxisomal CSY are expressed in Arabidopsis seedlings, and seeds from plants with both CSY genes disrupted were dormant and did not metabolize triacylglycerol. Germination was achieved by removing the seed coat and supplying sucrose, but the seedlings still did not use triacylglycerol. The mutant seedlings were resistant to 2,4-dichlorophenoxybutyric acid, indicating a block in peroxisomal β-oxidation, and were unable to develop further after transfer to soil. The mutant phenotype was complemented with a cDNA encoding CSY with either its native peroxisomal targeting sequence (PTS2) or a heterologous PTS1 sequence from pumpkin (Cucurbita pepo) malate synthase. These results suggest that peroxisomal CSY in Arabidopsis is not only a key enzyme of the glyoxylate cycle but also catalyzes an essential step in the respiration of fatty acids. We conclude that citrate is exported from the peroxisome during fatty acid respiration, whereas in yeast, acetylcarnitine is exported.
Microstimulation of the Dorsolateral Prefrontal Cortex Biases Saccade Target Selection
Authors: Opris Ioan , Barborica Andrei , Ferrera Vincent P. 
Published: May 2005

Abstract
A long-standing issue concerning the executive function of the primate dorsolateral prefrontal cortex is how the activity of prefrontal neurons is linked to behavioral response selection. To establish a functional relationship between prefrontal memory fields and saccade target selection, we trained three macaque monkeys to make saccades to the remembered location of a visual cue in a delayed spatial match-to-sample saccade task. We electrically stimulated sites in the prefrontal cortex with subthreshold currents during the delay epoch while monkeys performed this task. Our results show that the artificially injected signal interacts with the neural activity responsible for target selection, biasing saccade choices either towards the receptive/movement field (RF/MF) or away from the RF/MF, depending on the stimulation site. These findings might reflect a functional link between prefrontal signals responsible for the selection bias by modulating the balance between excitation and inhibition in the competitive interactions underlying behavioral selection.
Subliminal Convergence of Kanji and Kana Words: Further Evidence for Functional Parcellation of the Posterior Temporal Cortex in Visual Word Perception
Authors: Nakamura Kimihiro , Dehaene Stanislas , Jobert Antoinette , Bihan Denis Le , Kouider Sid 
Published: May 2005

Abstract
Recent evidence has suggested that the human occipito-temporal region comprises several subregions, each sensitive to a distinct processing level of visual words. To further explore the functional architecture of visual word recognition, we employed a subliminal priming method with functional magnetic resonance imaging (fMRI) during semantic judgments of words presented in two different Japanese scripts, Kanji and Kana. Each target word was preceded by a subliminal presentation of either the same or a different word, and in the same or a different script. Behaviorally, word repetition produced significant priming regardless of whether the words were presented in the same or different script. At the neural level, this cross-script priming was associated with repetition suppression in the left inferior temporal cortex anterior and dorsal to the visual word form area hypothesized for alphabetical writing systems, suggesting that cross-script convergence occurred at a semantic level. fMRI also evidenced a shared visual occipito-temporal activation for words in the two scripts, with slightly more mesial and right-predominant activation for Kanji and with greater occipital activation for Kana. These results thus allow us to separate script-specific and script-independent regions in the posterior temporal lobe, while demonstrating that both can be activated subliminally.