bluuebunny/crossref_metadata_2025 huggingface dataset:
Predictors of CD4 count change over 8 months of follow up in HIV‐1‐infected patients with a CD4 count≥300 cells/μL who were assigned to 7.5 MIU interleukin‐2
Authors:   The ESPRIT Research Group
Published: March 2007

Background

ESPRIT is a randomized trial comparing the clinical impact of interleukin (IL)‐2 plus antiretrovirals vs antiretrovirals alone. Identification of factors that influence the relationship between IL‐2 and CD4 count recovery will enable better personalization of treatment with IL‐2 in HIV‐1‐positive individuals. The IL‐2 induction phase consists of three dosing cycles over 6–8 months (7.5 MIU twice a day, for 5 days every 8 weeks).

Methods

We included patients initiating IL‐2 at the 7.5 MIU dose with an 8‐month CD4 count, measured at least 30 days after their last cycle. We identified baseline predictors of CD4 count changes over 8 months using linear regression.

Results

Of 2090 patients assigned IL‐2, 1673 (80%) were included in the analysis. The median (interquartile range) baseline CD4 count was 461 (370, 587) cells/μL with a median increase of 233 (90, 411) cells/μL at month 8. After adjustments, significant predictors of CD4 count change included CD4 nadir (29.8 cells/μL greater increase per 100 cells/μL higher; P<0.0001), last CD4 count before baseline (mean 36.0 cells/μL greater increase per 100 cells/μL higher; P<0.0001), time from antiretroviral start to baseline (8.3 cells/μL smaller increase per year longer; P=0.001), age (11.7 cells/μL smaller increase per 5 years older; P=0.005) and race (79.7 cells/μL greater increase for black patients vs white patients; P=0.003). A linear relationship existed between total IL‐2 dose in the first cycle and CD4 count change (73.1 cells/μL greater increase per 15 MIU higher; P<0.0001).

Conclusions

Prior nadir and current CD4 counts, age and IL‐2 dose are major determinants of CD4 increases induced by with intermittent administration of IL‐2 in HIV‐1‐positive individuals on antiretrovirals. The clinical function of these induced CD4 cells is under study.
Using Person–Organization Fit to Select Employees for High‐Turnover Jobs
Authors: McCulloch Malcolm C. , Turban Daniel B.
Published: March 2007

Using a concurrent validation strategy, we examine the incremental value of a measure of actual person–organization fit (P–O fit) as a selection tool beyond cognitive ability for predicting continued length of service and performance for call center agents, a job with historically high turnover. P–O fit was operationalized as the correlation between managers' descriptions of the work culture with participants' work preferences. P–O fit added significant incremental variance in predicting employee retention, but was not related to performance. We discuss the implications of the results and suggest that firms should consider using measures of P–O fit in their selection battery, in particular when turnover is a significant problem.
Self‐Monitoring and Job Performance: The moderating role of tenure
Authors: Moser Klaus , Galais Nathalie
Published: March 2007

Previous research on the relationship between self‐monitoring and job performance has neglected the role of tenure even though both theory and preliminary evidences suggest that job incumbents' tenure should be a strong moderator. The current study investigates the role of organizational tenure on the relationship between self‐monitoring and job performance (number of new contracts sold) in a sample of sales insurance agents. Consistent with expectations, tenure moderates the relationship between self‐monitoring and job performance, i.e., self‐monitoring is positively correlated with job performance for job incumbents with less tenure but not for those with more tenure. We propose that the relationship between self‐monitoring and job performance depends on the job incumbents' ability and opportunity to control the cues available to those who interact with and/or appraise the performance of the job incumbent.
Personality Traits and Job Success: An investigation in a Thai sample1
Authors: Smithikrai Chuchai
Published: March 2007

The purpose of this study was to examine the predictive power of each facet of the five‐factor model of personality on job success in a Thai sample. The sample consisted of 2518 persons from seven occupations. The research found that for all occupational groups neuroticism was significantly negatively correlated with job success, while extraversion and conscientiousness were significantly positively correlated with job success. Moreover, conscientiousness was the only personality trait that consistently predicted job success of persons across occupations.
Effects of Self‐Deceptive Enhancement on Personality–Job Performance Relationships
Authors: Berry Christopher M. , Page Ronald C. , Sackett Paul R.
Published: March 2007

Theoretical and empirical evidence distinguishes between two types of response distortion: impression management (IM) and self‐deceptive enhancement (SDE), although most research in Industrial/Organizational Psychology has focused on the effects of IM. The present study compared the effects of IM and SDE on job performance and personality validity. Two‐hundred and sixty‐one managers completed Big Five Personality, SDE, and IM measures. The managers' supervisors, peers, and subordinates rated their job performance. In accordance with previous research, accounting for managers' IM scores did not increase prediction of job performance. On the other hand, accounting for SDE did increase prediction. Increased prediction was due to an interaction between Extraversion and SDE, and an increase in the predictive validity of Emotional Stability when SDE was held constant. Results suggested that findings from previous research demonstrating that IM does not affect job performance or personality validity cannot be extended to SDE.
Relationships between Personality and Organization Switching: Implications for utility estimates
Authors: Vinson Gregory A. , Connelly Brian S. , Ones Deniz S.
Published: March 2007

This study examined individuals' tendencies to migrate from one organization to another (i.e., the propensity to switch employers). Previous researchers have suggested that switching organizations throughout the career span may be partially heritable and therefore related to individual differences in personality traits. If personality traits are indeed related to a tendency to turnover from organizations, this suggests that current procedures for calculating utility may be inaccurate. Using a database of 1081 individuals who have been in the workforce for several years, results indicated that personality traits measured by the Occupational Personality Questionnaire (non‐ipsative; OPQn) were modestly related to organization switching (i.e., repeated moves from organization to organization). We found that higher scores on extraversion, openness to experience, and conscientiousness‐related traits were modestly correlated with more frequent organization switching. However, we demonstrate that these modest relationships can produce large inaccuracies in utility estimates.
Short telomeres in short‐lived males: what are the molecular and evolutionary causes?
Authors: Jemielity Stephanie , Kimura Masayuki , Parker Karen M. , Parker Joel D. , Cao Xiaojian , Aviv Abraham , Keller Laurent
Published: March 2007

Telomere length regulation is an important aspect of cell maintenance in eukaryotes, since shortened telomeres can lead to a number of defects, including impaired cell division. Although telomere length is correlated with lifespan in some bird species, its possible role in aging and lifespan determination is still poorly understood. Here we investigate telomere dynamics (changes in telomere length and attrition rate) and telomerase activity in the ant Lasius niger, a species in which different groups of individuals have evolved extraordinarily different lifespans. We found that somatic tissues of the short‐lived males had dramatically shorter telomeres than those of the much longer‐lived queens and workers. These differences were established early during larval development, most likely through faster telomere shortening in males compared with females. Workers did not, however, have shorter telomeres than the longer‐lived queens. We discuss various molecular mechanisms that are likely to cause the observed sex‐specific telomere dynamics in ants, including cell division, oxidative stress and telomerase activity. In addition, we discuss the evolutionary causes of such patterns in ants and in other species.
Biocompatibility of a Novel Avidin‐Agarose Adsorbent for Extracorporeal Removal of Redundant Radiopharmaceutical From the Blood
Authors: Kurkus Jan , Nilsson Rune , Lindén Ola , Schönström Niki , Sandberg Bengt E.B. , Tennvall Jan
Published: March 2007

Abstract:  The use of monoclonal antibodies (MAbs) in cytotoxic conjugates (radionuclides, toxins, or drugs) for targeting tumor cells is restricted due to toxicity in vital organs. Through improved tumor targeting, it is possible to administer larger amounts of such labeled MAbs, thus improving the ability to eradicate tumor cells without increased normal organ toxicity. Extracorporeal affinity adsorption treatment (ECAT) has therefore been developed using an avidin‐agarose (AA) adsorbent with high binding affinity for the biotinylated radiolabeled MAb, rituximab. During ECAT, excess radioimmunoconjugates, not bound to the tumor cells, can be removed improving tumor targeting. The present study was performed to estimate the biocompatibility of the AA adsorber. Seven patients with B‐cell lymphoma not responding to conventional treatment were studied. During the ECAT procedure, blood (B) components, plasma (P) complement fragments C3a, C5a, and P‐bradykinin were analyzed, and other laboratory tests were carried out. Slight decreases in B‐hemoglobin (8.3%), B‐thrombocytes (11.4%), and P‐albumin (14.3%) were observed, and could be explained by the dilution of the blood with normal saline and acid citrate dextrose. The AA adsorbent had no effect on the blood cells, immunological status or P‐bradykinin level. The AA adsorber demonstrated good hemocompatibility and biocompatibility, without any side effects in the patients.
Why Does the Federal Government Appeal to the Supreme Court of Canada in Charter of Rights Cases? A Strategic Explanation
Authors: Hennigar Matthew A.
Published: March 2007

Despite the impressive body of scholarship dedicated to analyzing litigation involving the Charter of Rights and Freedoms in the Supreme Court of Canada, there remains an incomplete understanding of why these cases come to the Court. Notably absent from the literature is sustained analysis of why governments, the most frequent class of appellant, bring Charter cases to the Supreme Court. Recent work has addressed the decision to appeal by the U.S. federal government and state attorneys general and provides an excellent theoretical starting point. I use case data collected from interviews with federal government lawyers and law reports to test whether the Canadian federal government's decisions to appeal to the Supreme Court of Canada in Charter cases are also “procedurally rational.” I conclude that these decisions are primarily shaped by strategic considerations related to policy costs, case importance, reviewability, and the prospect of winning on appeal, regardless of the party in power. In the process, the article further extends the application of strategic decisionmaking theory with regard to law and courts beyond judicial behavior, and beyond the U.S. context.
The Role of Death Qualification in Capital Trials Involving Juvenile Defendants1
Authors: Butler Brooke
Published: March 2007

The purpose of this study was to investigate the role of death qualification in capital trials involving juvenile defendants. Two hundred residents of the 12th Judicial Circuit in Florida completed a booklet of stimulus materials that contained the following: One question that measured participants' level of support for the death penalty; One Witt death‐qualification question; a summary of the guilt and penalty phases of a capital case involving either an adult or a juvenile defendant; sentence preference; the Revised Legal Attitudes Questionnaire (RLAQ); and standard demographic questions. Results indicated that death‐qualified participants were more likely to sentence both defendants to death. In addition, death‐qualified participants were more likely to recommend the death sentence for the juvenile defendant. Legal implications are discussed.
Melatonin treatment reduces the severity of experimental Trypanosoma cruzi infection
Authors: Santello Fabrícia Helena , Frare Eduardo Osório , Dos Santos Carla Domingues , Toldo Míriam Paula Alonso , Kawasse Laura Midori , Zucoloto Sérgio , Do Prado José Clóvis
Published: March 2007

Abstract:  Prior studies show that melatonin enhances the immune response. This study investigated the possible therapeutic effects of melatonin during the course of Trypanosoma cruzi infection. T. cruzi‐infected male Wistar rats were orally treated with 5 mg/kg body weight/day of melatonin. Animals treated with melatonin showed a significant reduction in the number of blood trypomastigotes during the acute phase of infection compared with untreated animals (P < 0.05). A significant increase in leucocytes numbers during the peak of parasitaemia was also observed (P < 0.05). Moreover, both prior and concomitant treatment with melatonin increased interleukin‐2 levels, especially 9 days postinfection (P < 0.05). Histopathological observations of heart tissue revealed that melatonin administration also resulted in fewer and smaller amastigote burdens, and less inflammatory infiltrate and tissue disorganization, indicating a reduced parasitism of this tissue. These results show that melatonin is effective in controlling parasite replication and suggest that melatonin might serve as an effective therapeutic agent in the treatment of American trypanosomiasis.
Urinary excretion of purine derivatives and plasma allantoin level in sheep and goats during fasting
Authors: FUJIHARA Tsutomu , SHEM Martin N. , MATSUI Tohru
Published: March 2007

The relationship between blood plasma level and urinary excretion of allantoin (AN) was examined in sheep and goats during fasting to investigate the possible use of purine derivatives (PD) in urine and/or plasma for estimating the microbial protein production in the rumen, and the further digestion in the lower guts of ruminants. Urinary AN excretion decreased markedly during fasting (0.13 mmol/kgW0.75 per day), although urinary levels of other PD, hypoxanthine + xanthine and uric acid did not differ irrespective of the feeding condition, that is, feeding, fasting and refeeding in both species. The AN concentration in blood plasma also decreased drastically in the starvation period, and was suddenly increased on refeeding in sheep and goats, and these phenomena were very similar to those of urinary AN excretion. Therefore, there was a high positive correlation between plasma AN level and urinary AN excretion, and the coefficient of correlation was statistically significant (P < 0.01). These results clearly indicate that changes in urinary AN reflect change in plasma AN, which is induced by the catabolism of purine base in the body.
Validation and application of real‐time polymerase chain reaction assays for representative rumen bacteria
Authors: KOIKE Satoshi , YABUKI Hiroyoshi , KOBAYASHI Yasuo
Published: March 2007

Real‐time polymerase chain reaction (PCR) assays for 11 representative rumen bacterial species were validated. The sensitivity was tested by using the serially diluted target 16S rDNA from respective bacterial species. The recovery of the target DNA and the assay reproducibility were determined using DNA from rumen fluid spiked with different quantities of the target. Minimum detection levels for the target were 10–100 copies in pure culture. The recovery of the added target ranged from 82.4 to 116.6%. The intra‐ and inter‐assay variations of each assay were <9.4 and <12.6%, respectively. Therefore, the real‐time PCR assays evaluated in the present study are considered to be sufficiently reliable for monitoring all 11 bacterial species in the rumen. The assays were then applied to the monitoring of the bacterial species attached to ruminally incubated rice straw. Among the monitored fibrolytic species, Fibrobacter succinogenes was found to be the most dominant, accounting for 2.61% of total bacteria after 24 h incubation. Selenomonas ruminantium and Streptococcus bovis, non‐fibrolytics, were detected on the rice straw at 8.96% and 1.16% of total bacteria, respectively. Such high levels of non‐fibrolytics on the plant fiber suggest a synergistic relationship between fibrolytics and non‐fibrolytics.
Effects of field pea (Pisum sativum L.) hay feeding on dry matter intake and milk production of Murrah buffaloes (Bubalus bubalis) fed rice straw ad libitum
Authors: HAYASHI Yoshiaki , DEVKOTA Naba Raj , KUMAGAI Hajime
Published: March 2007

To identify the effects of field pea hay (FPH) as a supplement of rice straw (RS) on feed intake and milk production of mid‐late lactation buffaloes in Tarai, Nepal, nine multiparous Murrah were fed a concentrate at 0.6% of their bodyweight (BW) on a concentrate dry matter (DM) basis daily while having ad libitum access to RS. The buffaloes were divided into three groups, and the experiment with three levels of FPH feeding was conducted at the following rate of BW: 0% (T1), 0.5% (T2) and 1.0% (T3) on an FPH DM basis. The DM intake (DMI) was higher in T2 and T3 than in T1. As the amount of FPH was raised, the BW change, crude protein intake (CPI) and total digestible nutrient intake (TDNI) was increased. Although the yield of milk and milk composition did not differ among the treatments, the 7% fat corrected milk yield (FCMY) tended to increase as FPH feeding amount was raised. Although there were no significant differences in FCMY/DMI and FCMY/TDNI among the treatments, FCMY/CPI decreased with FPH feeding. Supplementary FPH increased DMI, CPI and TDNI that might have raised BW, and tended to improve FCMY in mid‐late lactating buffaloes as a result of an increase in TDNI.
Physiological responses of transported goats treated with ascorbic acid during the hot‐dry season
Authors: MINKA Ndazo Salka , AYO Joseph Olusegun
Published: March 2007

The aim of the present study was to determine the physiological responses of transported Red Sokoto goats (RSG) treated with ascorbic acid (AA). Ten RSG treated orally with ascorbic acid served as experimental subjects, while seven goats treated with sterile water served as the control. The goats were transported for 8 h. The ambient temperature and relative humidity during the study period fluctuated between 21 and 38°C and 51 and 91%, respectively, which indicated that the season was thermally stressful and did not favor transportation of goats. The rectal temperature obtained in the control goats was significantly higher (P < 0.01) than the value in the experimental goats after transportation. There was a significant decrease (P < 0.05) in eosinophil counts and an increase (P < 0.01) in neutrophil counts and neutrophil : lymphocyte ratio recorded in the control goats after transportation, which suggested that the control goats were physically and emotionally stressed. The control goats lost 11.9% of their initial liveweight, while the experimental goats lost only 1.04% after transportation. Multiple stresses, including extreme meteorological factors, acted upon the transported goats and impaired their homeostatic mechanism. In conclusion, AA administration in goats reduced the adverse effects of road transportation stress.
Effect of regular walking exercise on glucose tolerance and insulin response to i.v. glucose infusion in growing beef steers
Authors: AOKI Yasuhiro , YAMADA Tomoya , NAKANISHI Naoto
Published: March 2007

The purpose of the present paper was to investigate the effect of regular walking exercise on glucose tolerance and insulin response to i.v. glucose infusion in growing beef steers. Four crossbred beef steers walked on a treadmill during a 6 week exercise period (1.2 km/h, 1 h/day and 5 days/week). The changes in plasma glucose and insulin levels following glucose infusion were analyzed immediately prior to (bodyweight: 260.4 ± 24.2 kg) and after (295.7 ± 30.1 kg) the exercise period. The basal levels of plasma glucose (86.4 vs. 82.0 mg/dL, P = 0.040) and insulin (24.5 vs. 14.3 μU/mL, P = 0.016) were significantly lower after the exercise period. Further, the increase in the levels of plasma glucose (420.4 vs. 280.8 mg/dL, P < 0.001) and insulin (94.5 vs. 73.1 μU/mL, P = 0.028) following the glucose infusion decreased after the exercise period. The area under the curve of plasma glucose (108.8 vs. 62.9 mg/dL per min, P < 0.001) and insulin (53.6 vs. 29.7 μU/mL per min, P = 0.018) indicated more rapid clearance of exogenous glucose and less insulin secretion for glucose clearance after the exercise period. These results suggest that regular exercise improves glucose tolerance, with lower insulin response to glucose infusion in growing steers, as observed in rodents and humans.
Molecular cloning of Pit‐1 cDNA and genomic DNA of the domestic duck (Anas platyrhynchos)
Authors: KANSAKU Norio , OHKUBO Takeshi , GUÉMENÉ Daniel , KÜHNLEIN Urs , ZADWORNY David
Published: March 2007

The expression of unique isoform of pituitary transcription factor (Pit‐1) is reported in the chicken and turkey. However, it is not well known whether this isoform is expressed in the other avian species. In the present study, complementary DNA (cDNA) and genomic DNA, of Pit‐1 of domesticated duck, were cloned and sequenced. Duck Pit‐1α was found to have 93.3, and 92.4% sequence identity at the cDNA level to Pit‐1α of chicken and turkey, respectively. The predicted amino acid sequence had 96.7% similarity with a comparable region of Pit‐1α of both chicken and turkey. Based on the cDNA sequence, the genomic structure of the gene was characterized. The duck Pit‐1 gene consisted of seven exons and six introns. Sequence analysis of the duck Pit‐1 gene allowed for the design of a forward primer for amplification of Pit‐1γ, which is synthesized from an alternative transcription initiation site in galliforms. Reverse transcription of total RNA followed by polymerase chain reaction successively amplified a 984 bp product of Pit‐1γ cDNA, which encoded a peptide of 326 amino acids. These results suggest that the expression of Pit‐1 isoform originates from a different site of transcription initiation, which is not unique to galliforms but is observed in other avian species including anseriforms.
Effects of intramuscular fat deposition on the beef traits of Japanese Black steers (Wagyu)
Authors: UEDA Yasuko , WATANABE Akira , HIGUCHI Mikito , SHINGU Hiroyuki , KUSHIBIKI Shiro , SHINODA Mitsuru
Published: March 2007

Effects of intramuscular fat deposition on the chemical composition, tenderness, and free amino acids (FAA) concentration of beef were studied using various classified carcasses of 21 Japanese Black (Wagyu) steers. The Beef Marbling Standard (BMS) No., judged on the market in 1998, and fat content, ranged from 2 to 10 and 4.8 to 39.0% in the M. longissimus thoracis, respectively. Moisture content was negatively correlated with the fat content (r =−0.98, P < 0.01). In contrast, protein content was relatively constant up to approximately 23% fat, corresponding to BMS No.4, and decreased as the fat content increased. Cooking loss was also constant up to approximately 28% fat, corresponding to BMS No.4, and markedly decreased with fat content increase. The beef in these cases were, however, classified into BMS No. around 9 and 11, respectively, according to the BMS model in 1988. A negative correlation was found between the shear‐force value and the fat content (r =−0.83, P < 0.05). Most FAA concentrations on the wet weight of meat were correlated negatively with the fat content, except glutamine, and this negative relationship was still observed when the concentrations were recalculated on the basis of protein. These results indicate that higher marbling Wagyu beef (above approx. 23% fat) would have an extremely lower content of protein, which would partly explain the lower cooking loss and FAA with fat increase. In addition, some other reasons not relating to protein content (e.g. high fat content preventing the breakdown of protein to FAA) seem to explain the negative correlation between fat and FAA.
Regulation of Light Energy Utilization and Distribution of Photosynthesis in Five Subtropical Woody Plants
Authors: Liu Nan , Peng Chang‐Lian , Lin Zhi‐Fang , Lin Gui‐Zhu , Pan Xiao‐Ping
Published: March 2007

The adaptations and responses of photosynthesis to long‐ and short‐term growth light gradient treatments were investigated in five subtropical forest plants, namely Pinus massoniana Lamb., Schima superba Gardn. et Champ., Castanopsis fissa (Champ. ex Benth.) Rehd. et Wils., Acmena acuminatissima (BI.) Merr et Perry, and Cryptocarya concinna Hance. With diurnal changes in sunlight and air temperature, the de‐epoxidation state and lutein content in the five woody plants under three light intensities first increased and then decreased during the day. However, maximal photochemical efficiency (Fv/Fm; where Fm is the maximum fluorescence yield and Fv is variable fluorescence) and the photochemical quantum yields of photosystem (PS) II (ΦPSII) of the species examined changed in the opposite manner, with those in plants grown under 100% natural light changing the most. After long‐term treatment (21 months), anti‐oxidant capacity (1, 1‐diphenyl‐2‐picrylhydrazyl radical (DPPH·)‐scavenging capacity) and utilization of excitation energy showed differences in modulation by different light intensities. It was shown that A. acuminatissima and C. concinna, as dominant species in the late succession stage of a subtropical forest in Dinghu mountain, South China, were better able to adapt to different light environments. However, P. massoniana, the pioneer species of this forest, exhibited less adaptation to low light intensity and was definitely eliminated by the forest succession process.
Photosynthetic and Respiratory Acclimation to Experimental Warming for Four Species in a Tallgrass Prairie Ecosystem
Authors: Zhou Xuhui , Liu Xiaozhong , Wallace Linda L. , Luo Yiqi
Published: March 2007

Global temperature has been increased by 0.6 °C over the past century and is predicted to increase by 1.4‐5.8 °C by the end of this century. It is unclear what impacts global warming will have on tallgrass species. In the present study, we examined leaf net photosynthetic rate (Pn) and leaf respiration rate in darkness (Rd) of Aster ericoides (L.) Nesom, Ambrosia psilostachya DC., Helianthus mollis Lam., and Sorghastrum nutans (L.) Nash in response to experimental warming in a tallgrass prairie ecosystem of the Great Plains, USA, in the autumn (fall) of 2000 and through 2001. Warming has been implemented with infrared heaters since 21 November 1999. The Pn increased significantly in spring, decreased in early fall, and did not change in summer and late fall in the four species under warming compared with control. The Rd of the four species increased significantly until mid‐summer and then did not change under warming. Measured temperature‐response curves of Pn showed that warming increased the optimum temperature of Pn (Topt) by 2.32 and 4.59 °C for H. mollis and S. nutans, respectively, in August, whereas there were no changes in May and September, and A. ericoides and A. psilostachya also showed no changes in any of the 3 months. However, Pn at optimum temperature (Popt) showed downregulation in September and no regulation in May and August for all four species. The temperature‐response curves of Rd illustrate that the temperature sensitivity of Rd, Q10, was lower in the warmed plots compared with the control plots, except for A. ericoides in August, whereas there were no changes in May and September for all four species. The results of the present study indicate that photosynthetic and respiratory acclimation varies with species and among seasons, occurring in the mid‐growing season and not in the early and late growing seasons.
Analysis of Genetic Diversity and Relationships in a Tunisian Fig (Ficus carica) Germplasm Collection by Random Amplified Microsatellite Polymorphisms
Authors: Chatti Khaled , Saddoud Olfa , Salhi‐Hannachi Amel , Mars Messaoud , Marrakchi Mohamed , Trifi Mokhtar
Published: March 2007

The random amplified mirosatellite polymorphism method was performed in a set of Tunisian fig landraces using eighteen primer combinations. A total of sixty three random amplified microsatellite polymorphism (RAMPO) markers were scored and used either to assess the genetic diversity in these cultivars or to detect cases of mislabeling. Opportunely, data proved that the designed procedure constitutes an attractive and fast method with low costs and prevents radio exposure. As a result, we have identified the primer combinations that are the most efficient to detect genetic polymorphism in this crop. Therefore, the derived unweighted pair‐group method with arithmetic averages (UPGMA) dendrogram illustrates the genetic divergence among the landraces studied and exhibits a typically continuous variation. Moreover, no evident correlation between the sexes of trees was observed. In addition, using these markers, discrimination between landraces has been achieved. Thus, random amplified mirosatellite polymorphism is proved to be powerful for characterizing the local fig germplasm.
Molecular and Functional Characterization of Sphingosine‐1‐Phosphate Lyase Homolog from Higher Plants
Authors: Niu Yan , Chen Kunling , Wang Jizhou , Liu Xin , Qin Huanju , Zhang Aimin , Wang Daowen
Published: March 2007

Sphingosine‐1‐phosphate lyase (SPL) is involved in degrading the conserved sphingolipid signaling molecule sph‐ingosine‐1‐phosphate. However, molecular studies on plant SPL have not been reported to date. Here, we present bioinformatic, molecular and functional analyses of putative SPL proteins from Arabidopsis thaliana and rice (designated as AtSPL and OsSPL, respectively). Amino acid sequence comparison revealed that plant SPL contained the pyridoxal‐dependent decarboxylase domain and the conserved residue that may be involved in substrate catalysis. When expressed in Saccharomyces cerevisiae, AtSPL and OsSPL corrected the hypersensitive phenotype of the yeast dpl1 deletion strain, which is deficient in endogenous SPL activity, to exogenous supplied sphingolipid long chain bases (LCBs), suggesting that plant SPL protein is functional in vivo in degrading phosphorylated LCBs. In Arabidopsis, AtSPL transcripts were detected in roots, stems, leaves, flowers and siliques. In pAtSPL‐AtSPL::GUS transgenic lines, the AtSPL::GUS fusion protein was found in a variety of vegetative and reproductive tissues. AtSPL expression level was dynamically regulated during leaf development and senescence, and was steadily and significantly increased in Arabidopsis seedlings treated with the cell death‐inducing fungal toxin fumonisin B1. The potential function of SPL in Arabidopsis is discussed.
GAMT2 Encodes a Methyltransferase of Gibberellic Acid That is Involved in Seed Maturation and Germination in Arabidopsis
Authors: Xing Shufan , Qin Genji , Shi Yan , Ma Zhiqiang , Chen Zhangliang , Gu Hongya , Qu Li‐Jia
Published: March 2007

Salicylic acid methyltransferase (SAMT), benzoic acid methyltransferase (BAMT) and theobromine methyltransferase (TH) (henceforth, SABATH) family proteins belong to a unique class of methyltransferase that can methylate small molecular compounds including indole‐3‐acidic acid (IAA), salicylic acid (SA) and jasmonic acid (JA), in plants. Here we report that the GAMT2 protein, which has 34.2% similarity with IAMT1 in the amino acid sequence, can methylate gibberellic acid (GA). Bioinformatics analysis suggests that GAMT2 may be able to methylate one molecule larger than SA. GAMT2 is predominantly expressed in the developing seed embryo and endosperm in Arabidopsis. During seed germination, the expression of GAMT2 decreases until the cotyledons expand out of the seed coat. Overexpression of GAMT2 in Arabidopsis resulted in multiple phenotypes, including dwarfism, retarded growth, late flowering, and reduced fertility, which are similar to the phenotypes of GA‐deficient mutants. Seed germination assay showed that GAMT2 overexpression in plants was hypersensitive to GA biosynthesis inhibitor (ancymidol) and abscisic acid (ABA) treatments, whereas the GAMT2 null mutant (SALK_075450) was slightly insensitive to such treatments, suggesting that GAMT2 may methylate GA or ABA. Enzyme activity analysis indicated that GAMT2 was able to methylate GA3 into Methyl‐GA3in vitro, but could not methylate ABA. Microarray analysis on GAMT2 overexpression plants suggested that Methyl‐GA may be an inactive form of GA in Arabidopsis. These data suggest that GAMT2 is involved in seed maturation and germination by modulating GA activity.
‘An important obligation of citizenship’: language, citizenship and jury service
Authors: Parry R Gwynedd
Published: March 2007

This paper considers whether there should be the power to summon bilingual juries in criminal trials in Ireland and Wales. It will examine the relationship between jury service as an obligation and privilege of citizenship, and the eligibility for jury service of Irish and Welsh speakers as a linguistic group. It will also demonstrate the relationship between the citizenship argument in its collective context and the rights and interests of individual speakers of these languages within the criminal jury trial process. In doing so, it seeks to emphasise that this is a multidimensional issue which requires an evaluation from a combination of perspectives, both collective and individual. It is this combination of perspectives, taken conjunctively, that supports the case for bilingual juries. Moreover, this particular debate has a particular relevance to the wider debate on European citizenship and how Europe views the concept of multilingual citizenship within its constitutional framework. Indeed, it raises fundamental questions about how Europe manages its diverse cultural and linguistic heritage and how speakers of minority languages are integrated on a basis of equality and respect towards their cultural and linguistic autonomy. The paper also addresses the objections to bilingual juries and will explore how the advent of bilingual juries could continue to preserve the random selection principle (the primary objection to bilingual juries) sufficiently to bring about fair, impartial and competent tribunals.
Physics of a balloon lens
Authors: Thomas Derek C. , Gee Kent L. , Turley R. Steven
Published: March 2007

A balloon filled with a gas that has a different sound speed than that of air has been used by science teachers in the past as an acoustic lens. One purpose of the lens is to show refraction of sound waves as an analogy to geometric optics [H. Kruglak and C. C. Kruse, Am. J. Phys. 8, 260–261 (1940)]. This paper discusses the physics involved with the balloon lens demonstration. In order to determine the validity of a balloon as a classroom demonstration of an acoustic lens and to understand the corresponding phenomena, the problem has been considered analytically, numerically, and experimentally. The results show that although a geometric analogy is a valid first order approximation, scattering theory is often required to fully understand the observed phenomena. Thus, this demonstration can be adapted to a wide range of students, from those learning basic principles of refraction to mathematically advanced students studying scattering.
Super Plastic Bulk Metallic Glasses at Room Temperature
Authors: Liu Yan Hui , Wang Gang , Wang Ru Ju , Zhao De Qian , Pan Ming Xiang , Wang Wei Hua
Published: March 2007

In contrast to the poor plasticity that is usually observed in bulk metallic glasses, super plasticity is achieved at room temperature in ZrCuNiAl synthesized through the appropriate choice of its composition by controlling elastic moduli. Microstructures analysis indicates that the super plastic bulk metallic glasses are composed of hard regions surrounded by soft regions, which enable the glasses to undergo true strain of more than 160%. This finding is suggestive of a solution to the problem of brittleness in, and has implications for understanding the deformation mechanism of, metallic glasses.
Activation of AMP-activated protein kinase stimulates proopiomelanocortin gene transcription in AtT20 corticotroph cells
Authors: Iwasaki Yasumasa , Nishiyama Mitsuru , Taguchi Takafumi , Kambayashi Machiko , Asai Masato , Yoshida Masanori , Nigawara Takeshi , Hashimoto Kozo
Published: March 2007

Starvation is known to activate the hypothalamo-pituitary-adrenal (HPA) axis, a representative antistress system in the living organism. In this study, we investigated in vitro whether activation of the AMP-activated protein kinase (AMPK), which is known to occur in intracellular energy depletion, influences the expression of POMC gene that encodes adrenocorticotropin. We first confirmed that each subunit of AMPK was expressed in the AtT20 corticotroph cell line. We then found that AICAR, a cell-permeable AMP analog and an activator of AMPK, potently stimulated the 5′-promoter activity of POMC gene in a dose-dependent manner. The effects were promoter specific because AICAR enhanced the AP1-mediated POMC promoter activities but did not influence other transcription factor-induced transcription. The effect of AICAR on POMC gene transcription was completely eliminated by specific AMPK inhibitor compound C or by dominant negative AMPK, whereas overexpression of constitutively active AMPK mimicked the effect of AICAR. Finally, experiments using specific kinase inhibitors suggested that the PI 3-kinase-mediated signaling pathway is at least partly involved in the effect. Our results suggest that intracellular energy depletion with the resultant activation of AMPK directly stimulates the HPA axis at the pituitary level by increasing the expression of POMC gene.
Infusion of a biotinylated bis-glucose photolabel: a new method to quantify cell surface GLUT4 in the intact mouse heart
Authors: Miller Edward J. , Li Ji , Sinusas Kevin M. , Holman Geoffrey D. , Young Lawrence H.
Published: March 2007

Glucose uptake in the heart is mediated by specific glucose transporters (GLUTs) present on cardiomyocyte cell surface membranes. Metabolic stress and insulin both increase glucose transport by stimulating the translocation of glucose transporters from intracellular storage vesicles to the cell surface. Isolated perfused transgenic mouse hearts are commonly used to investigate the molecular regulation of heart metabolism; however, current methods to quantify cell surface glucose transporter content in intact mouse hearts are limited. Therefore, we developed a novel technique to directly assess the cell surface content of the cardiomyocyte glucose transporter GLUT4 in perfused mouse hearts, using a cell surface impermeant biotinylated bis-glucose photolabeling reagent (bio-LC-ATB-BGPA). Bio-LC-ATB-BGPA was infused through the aorta and cross-linked to cell surface GLUTs. Bio-LC-ATB-BGPA-labeled GLUT4 was recovered from cardiac membranes by streptavidin isolation and quantified by immunoblotting. Bio-LC-ATB-BGPA-labeling of GLUT4 was saturable and competitively inhibited by d-glucose. Stimulation of glucose uptake by insulin in the perfused heart was associated with parallel increases in bio-LC-ATB-BGPA-labeling of cell surface GLUT4. Bio-LC-ATB-BGPA also labeled cell surface GLUT1 in the perfused heart. Thus, photolabeling provides a novel approach to assess cell surface glucose transporter content in the isolated perfused mouse heart and may prove useful to investigate the mechanisms through which insulin, ischemia, and other stimuli regulate glucose metabolism in the heart and other perfused organs.
Stevioside improves pancreatic β-cell function during glucotoxicity via regulation of acetyl-CoA carboxylase
Authors: Chen Jianguo , Jeppesen Per Bendix , Nordentoft Iver , Hermansen Kjeld
Published: March 2007

Chronic hyperglycemia is detrimental to pancreatic β-cells, causing impaired insulin secretion and β-cell turnover. The characteristic secretory defects are increased basal insulin secretion (BIS) and a selective loss of glucose-stimulated insulin secretion (GSIS). Several recent studies support the view that the acetyl-CoA carboxylase (ACC) plays a pivotal role for GSIS. We have shown that stevioside (SVS) enhances insulin secretion and ACC gene expression. Whether glucotoxicity influences ACC and whether this action can be counteracted by SVS are not known. To investigate this, we exposed isolated mouse islets as well as clonal INS-1E β-cells for 48 h to 27 or 16.7 mM glucose, respectively. We found that 48-h exposure to high glucose impairs GSIS from mouse islets and INS-1E cells, an effect that is partly counteracted by SVS. The ACC dephosphorylation inhibitor okadaic acid (OKA, 10−8M), and 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR, 10−4M), an activator of 5′-AMP protein kinase that phosphorylates ACC, eliminated the beneficial effect of SVS. 5-Tetrade-cyloxy-2-furancarboxylic acid (TOFA), the specific ACC inhibitor, blocked the effect of SVS as well. During glucotoxity, ACC gene expression, ACC protein, and phosphorylated ACC protein were increased in INS-1E β-cells. SVS pretreatment further increased ACC gene expression with strikingly elevated ACC activity and increased glucose uptake accompanied by enhanced GSIS. Our studies show that glucose is a potent stimulator of ACC and that SVS to some extent counteracts glucotoxicity via increased ACC activity. SVS possesses the potential to alleviate negative effects of glucotoxicity in β-cells via a unique mechanism of action.
Hypotonicity stimulates renal epithelial sodium transport by activating JNK via receptor tyrosine kinases
Authors: Taruno Akiyuki , Niisato Naomi , Marunaka Yoshinori
Published: March 2007

We previously reported that hypotonic stress stimulated transepithelial Na+transport via a pathway dependent on protein tyrosine kinase (PTK; Niisato N, Van Driessche W, Liu M, Marunaka Y. J Membr Biol 175: 63–77, 2000). However, it is still unknown what type of PTK mediates this stimulation. In the present study, we investigated the role of receptor tyrosine kinase (RTK) in the hypotonic stimulation of Na+transport. In renal epithelial A6 cells, we observed inhibitory effects of AG1478 [an inhibitor of the EGF receptor (EGFR)] and AG1296 [an inhibitor of the PDGF receptor (PDGFR)] on both the hypotonic stress-induced stimulation of Na+transport and the hypotonic stress-induced ligand-independent activation of EGFR. We further studied whether hypotonic stress activates members of the MAP kinase family, ERK1/2, p38 MAPK, and JNK/SAPK, via an RTK-dependent pathway. The present study indicates that hypotonic stress induced phosphorylation of ERK1/2 and JNK/SAPK, but not p38 MAPK, that the hypotonic stress-induced phosphorylation of ERK1/2 and JNK/SAPK was diminished by coapplication of AG1478 and AG1296, and that only JNK/SAPK was involved in the hypotonic stimulation of Na+transport. A further study using cyclohexamide (a protein synthesis inhibitor) suggests that both RTK and JNK/SAPK contributed to the protein synthesis-independent early phase in hypotonic stress-induced Na+transport, but not to the protein synthesis-dependent late phase. The present study also suggests involvement of phosphatidylinositol 3-kinase (PI3-kinase) in RTK-JNK/SAPK cascade-mediated Na+transport. These observations indicate that 1) hypotonic stress activates JNK/SAPK via RTKs in a ligand-independent pathway, 2) the RTK-JNK/SAPK cascade acts as a mediator of hypotonic stress for stimulation of Na+transport, and 3) PI3-kinase is involved in the RTK-JNK/SAPK cascade for the hypotonic stress-induced stimulation of Na+transport.
Role of peroxynitrite on cytoskeleton alterations and apoptosis in renal ischemia-reperfusion
Authors: Viñas Jose Luis , Hotter Gina , Pi Felip , Palacios Luis , Sola Anna
Published: March 2007

During renal ischemia-reperfusion (I/R) injury, apoptosis has been reported as a very important contributor to final kidney damage. The determinant role of cytoskeleton derangement in the development of apoptosis has been previously reported, but a clear description of the different mechanisms involved in this process has not been yet provided. The aim of our study was to know the role of peroxynitrite as an inductor of cytoskeleton derangement and apoptosis during renal I/R. Based on a rat kidney I/R model, using experiments in which both the actin cytoskeleton and peroxynitrite generation were pharmacologically manipulated, results indicate that the peroxynitrite produced during the I/R-derived oxidative stress state is able to provoke cytoskeleton derangement and apoptosis development. Thus control of peroxynitrite generation during I/R could be an effective tool for the improvement of cytoskeleton damage and reduction of apoptosis incidence in renal I/R injury.
Selective basolateral localization of overexpressed Na-K-ATPase β1- and β2- subunits is disrupted by butryate treatment of MDCK cells
Authors: Laughery Melissa D. , Clifford Rebecca J. , Chi Yiqing , Kaplan Jack H.
Published: March 2007

The exclusive basolateral localization of the Na-K-ATPase in kidney epithelium is a critical aspect of nephron function. It has been suggested that mislocalized delivery of the Na-K-ATPase to the apical surface in autosomal dominant polycystic kidney disease (ADPKD) is due to the inappropriate expression of an alternative isoform of the β-subunit, the β2-isoform. It has been reported that heterologous expression of this β2-isoform in Madin-Darby canine kidney (MDCK) cells results in apical delivery of the Na-K-ATPase. We created a MDCK cell line containing a tetracycline-inducible promoter and expressed either myc-tagged β2- or flag-tagged β1-subunits to study the surface localization of these β-subunit isoforms in polarized monolayers. We find that the β2-isoform is targeted to the basolateral surface of the plasma membrane in a polarization pattern indistinguishable from the β1-isoform. However, inclusion of butyrate in the growth medium leads to upregulation of overexpressed β1- or β2-subunits and to their appearance at the apical surface. The β2-isoform expressed in MDCK cells does not assemble into α1β2heterodimers with the endogenous α1. Our findings demonstrate that expression of the β2-isoform does not lead to apical localization of the Na-K-ATPase in MDCK cells and provides evidence for an unexpected effect of butyrate on the trafficking of Na pump subunits.