bluuebunny/crossref_metadata_2025 huggingface dataset:
Chronic inhibition of GABA synthesis in the bed nucleus of the stria terminalis elicits anxiety-like behavior
Authors: Sajdyk TJ , Johnson PL , Fitz SD , Shekhar A.
Published: February 2008

The current study tested the hypothesis that chronic loss of inhibitory GABAergic tone in the bed nucleus of the stria terminalis (BNST), a region implicated in anxiety behavior, results in generalized anxiety disorder-like behaviors without panic-like responses (i.e., tachycardia, hypertension and tachypnea) following panicogenic stimuli (e.g., sodium lactate infusions). To test this hypothesis, the GABA synthesis inhibitor L-allylglycine (L-AG) or its inactive isomer D-AG was chronically infused into the BNST of male rats via osmotic mini-pumps. L-AG, but not D-AG, treated rats had increased anxiety-like behavior as measured by social interaction (SI) and elevated-plus maze paradigms. Restoring GABAergic tone, with 100pmoles/100nl of muscimol (a GABAAreceptor agonist), in the BNST of L-AG treated rats attenuated L-AG-induced anxiety-like behavior in the SI test. To assess panic-like states, L-AG treated rats were intravenously infused with 0.5 M sodium lactate, a panicogenic agent, prior to assessing SI and cardiorespiratory responses. L-AG decreased SI duration again; however, sodium lactate did not induce panic-like cardiorespiratory responses. These findings demonstrate that GABA inhibition in the BNST elicits anxiety-like behavior without increasing sensitivity to lactate, thus suggesting a behavioral profile similar to that of generalized anxiety-like behavior rather than that of panic.
Ginsenoside Rg1 restores the impairment of learning induced by chronic morphine administration in rats
Authors: Qi D. , Zhu Y. , Wen L. , Liu Q. , Qiao H.
Published: February 2008

Rg1, as a ginsenoside extracted from Panax ginseng, could ameliorate spatial learning impairment. Previous studies have demonstrated that Rg1 might be a useful agent for the prevention and treatment of the adverse effects of morphine. The aim of this study was to investigate the effect of Rg1 on learning impairment by chronic morphine administration and the mechanism responsibe for this effect. Male rats were subcutaneously injected with morphine (10 mg/kg) twice a day at 12 hour intervals for 10 days, and Rg1 (30 mg/kg) was intraperitoneally injected 2 hours after the second injection of morphine once a day for 10 days. Spatial learning capacity was assessed in the Morris water maze. The results showed that rats treated with Morphine/Rg1 decreased escape latency and increased the time spent in platform quadrant and entering frequency. By implantation of electrodes and electrophysiological recording in vivo, the results showed that Rg1 restored the long-term potentiation (LTP) impaired by morphine in both freely moving and anaesthetised rats. The electrophysiological recording in vitro showed that Rg1 restored the LTP in slices from the rats treated with morphine, but not changed LTP in the slices from normal saline- or morphine/Rg1-treated rats; this restoration could be inhibited by N-methyl-D-aspartate (NMDA) receptor antagonist MK801. We conclude that Rg1 may significantly improve the spatial learning capacity impaired by chonic morphine administration and restore the morphine-inhibited LTP. This effect is NMDA receptor dependent.
Increased cortical inhibition in persons with schizophrenia treated with clozapine
Authors: Daskalakis Zafiris J , Christensen Bruce K , Fitzgerald Paul B , Moller Bertram , Fountain Sarah I , Chen Robert
Published: February 2008

It has been previously demonstrated that unmedicated persons with schizophrenia have deficits in cortical inhibition (CI) as indexed with transcranial magnetic stimulation (TMS). This inhibition is largely mediated by cortical GABAergic mechanisms. It has also been demonstrated that these inhibitory deficits may be normalized with the use of atypical antipsychotic medications. The purpose of this study, therefore, was to examine the effects of clozapine on TMS measures of CI and to compare these effects to unmedicated persons with schizophrenia and healthy subjects. We used two TMS inhibitory paradigms: short interval intra-cortical inhibition (SICI) and the cortical silent period (CSP) to evaluate CI in 10 clozapine-treated persons with schizophrenia, 6 unmedicated persons with schizophrenia and 10 healthy subjects. Clozapine-treated persons with schizophrenia had significantly longer CSPs compared with healthy subjects and unmedicated persons with schizophrenia. There were no significant differences in SICI between groups, however, the severity of psychotic symptoms was correlated with reduced SICI across all persons with schizophrenia. Our findings suggest that clozapine treatment is associated with greater CI in persons with schizophrenia and this increase may be related to potentiation of cortical GABAergic receptor mediated inhibitory neurotransmission. Our results also confirm previous findings suggesting that deficits in CI are related to the severity of psychotic symptoms in persons with schizophrenia.
The Effect of Temporary Employment on Asset Accumulation Processes
Authors: McGrath Donald M. , Keister Lisa A.
Published: February 2008

Temporary employment in the United States has increased considerably in recent decades, but the financial well-being of temporary employees is not well understood. This article examines the effect of both recent and past temporary employment on asset accumulation and portfolio behavior. The authors find that temporary work reduces workers' assets and that this negative effect remains even after a worker has left the temporary position. The authors also show that suppressed or delayed homeownership substantially contributes to the reduction of assets among temporary workers. These results provide insight into the role that work status plays in creating and maintaining wealth inequality.
Acculturation, Partner Violence, and Psychological Distress in Refugee Women From Somalia
Authors: Nilsson Johanna E. , Brown Chris , Russell Emily B. , Khamphakdy-Brown Supavan
Published: February 2008

This study examined the relations among acculturation, domestic violence, and mental health in 62 married refugee women from Somalia. Refugees from Somalia constituted the largest group of refugees entering the United States in 2005, and little is known about the presence of domestic violence in this group. The results showed that women who reported greater ability to speak English also reported more experiences of partner psychological abuse and physical aggression. Experiences of more psychological abuse and physical aggressions also predicted more psychological distress. Implications for future research and psychological services are addressed.
The Effects of Staff Training on the Types of Interactions Observed at Two Group Homes for Foster Care Children
Authors: Crosland Kimberly A. , Dunlap Glen , Sager Wayne , Neff Bryon , Wilcox Catherine , Blanco Alfredo , Giddings Tamela
Published: February 2008

Objectives: An extensive literature base exists for behavioral parent training; however, few studies have focused on training direct care staff at group home and residential facilities for children. This study was conducted to determine whether a behavioral staff training program consisting of classroom training and in-home feedback would improve staff interactions with children at two group foster care homes. Method: Staff at both homes were trained, and direct observation measures were obtained on positive and negative interactions and lack of interactions. A multiple-baseline design across homes was used to assess staff interaction behavior. Results: Increases in both positive interactions and tool use were observed in the treatment phase, as were decreases in negative interactions for both group homes. Conclusions: The results suggest that training direct care staff, including social workers, to use behavioral strategies change patterns of interaction, resulting in a greater likelihood of improved relationships between staff and children.
Critiquing Critiques
Authors: Dannels Deanna P. , Martin Kelly Norris
Published: February 2008

In the discipline of design, the most common presentation genre is the critique, and the most central aspect of this genre is the feedback. Using a qualitative framework, this article identifies a typology of feedback, compares the frequencies of feedback types between different levels of design studios ranging from novice to expert, and explores what the feedback reflects about the social and educational context of these design studios. Results suggest that the feedback socialized students into egalitarian relationships and autonomous decision-making identities that were perhaps more reflective of academic developmental stages or idealized workplace contexts than of actual professional settings—therefore potentially complicating the preprofessional goals of the critique.
Toward a Unified Social Theory of Genre Learning
Authors: Artemeva Natasha
Published: February 2008

This article discusses the development of a unified social theory of genre learning based on the integration of rhetorical genre studies, activity theory, and the situated learning perspective. The article proposes that these three theoretical perspectives are compatible and complementary, and it illustrates applications of a unified framework to a study of genre learning by novice engineers. The author draws examples from a longitudinal qualitative study of a group of novice engineers who developed their professional genre knowledge through both academic and workplace experiences. These examples illustrate the effectiveness of the proposed framework for the study of professional genre learning.
I Want to Talk About...
Authors: Van De Mieroop Dorien , de Jong Jaap , Andeweg Bas
Published: February 2008

This article investigates the introductions of 40 professional speeches from a rhetorical perspective to address the problems audiences seem to have with presentations about engineering. The authors use an exordial model that they derived from classical manuals on rhetoric. This model enumerates and groups rhetorical exordial techniques into 3 main functions: attentum, benevolum, and docilem . The study shows that rhetorically complete introductions are rare. Most of the speakers seemed to prefer a content-oriented, direct approach ( docilem) in their introductions and seldom used techniques to garner the audience's attention ( attentum) or sympathy ( benevolum). The article concludes with an evaluation of the exordial model and a discussion of the study's pedagogical implications.
Widening opportunities? A case study of school-to-school collaboration in a rural district
Authors: Muijs Daniel
Published: February 2008

In recent years, the principle of networking and collaboration has become more prevalent and more widely studied in education. Most research to date has been carried out in urban contexts. However, it can be argued that, for school improvement in rural areas, their specific circumstances make collaboration imperative. In this article, we discuss a Federation of rural schools as a case study of collaboration in rural areas. Collaboration was found to have major advantages in terms of widening provision and opportunities for learners and allowing schools to address vulnerable groups more effectively. However, some troublesome issues of power and equity remain in the collaborative and its relations to the broader area.
Queerness, the Quality Audience, and Comedy Central's Reno 911!
Authors: Griffin Hollis
Published: February 2008

Comedy Central currently attracts the same kind of quality audience that broadcast television networks courted in the 1990s, one that resulted in the sharp increase in gaythemed content on the networks at that time. Yet the parodic mode of address that so permeates the cable network's content makes the different levels of gay cultural competency a heterogeneous viewership brings to a program like Reno 911! an issue of considerable import. A parodic situation-comedy based on reality crime programming, Reno 911! narrativizes an ambiguously gay police detective who, in turn, provides different viewing pleasures for differently situated viewers. As such, the character foregrounds questions about the political consequences of television's use of queer cultural signifiers and the pleasures that viewers take in a parodic representation of queerness on television.
Health Risk Reduction in Women
Authors: Terre Lisa
Published: February 2008

This review discusses evidence-based perspectives on health risk reduction in women and the implications for gender-informed research, clinical best practices, and public policy.
Mathematical models in materials science
Authors: Bhadeshia H. K. D. H.
Published: February 2008

Modelling has now become a routine part of materials science. It is appropriate therefore to assess some of the successes and failures of the method and to understand how and if modelling differs from ordinary quantitative science. The subject is now sufficiently mature to bear some constructive self-criticism and to temper exaggerated claims. The discussion here of modelling methods and outcomes is intended to be generic, although the examples used come from the author's experience of work on metals.
Surface engineering of Ti–6Al–4V by nitriding and powder alloying using CW CO2 laser
Authors: Baker T. N. , Selamat M. S.
Published: February 2008

A comparison has been made of the laser processing of Ti–6Al–4V (IMI318) alloy by (a) nitriding under a dilute atmosphere, (b) preplacing 6 μm SiC powder and (c) a combination of (a) and (b). At least six laser tracks were overlapped. Microhardness maps allowed details of the variation in hardness with both melt depth and track number to be determined. The microstructure was characterised and related to the processing parameters, melt track dimensions, hardness and roughness data. It was found that the preheating generated due to the overlapping, influenced the individual track dimensions, microstructure and properties, which were also affected by the laser energy density and the nitrogen concentration in the nitriding atmosphere used in processing. Process (b) was shown to produce the smoothest surfaces, with Ra values<2 μm, while (c) gave the highest Ra value, 8·6 μm. These results are considered together with a wide range of data in the literature on laser processed Ti–6Al–4V.
Use of interconnected reinforcement in magnesium for stiffness critical applications
Authors: Thakur S. K. , Gupta M.
Published: February 2008

In the present study, magnesium composites with three different volume fractions of interconnected reinforcement (1·77, 2·65 and 3·85%) were successfully synthesised by using disintegrated melt deposition technique followed by hot extrusion. Microstructural characterisation revealed the absence of macro pores, minimal porosity and good reinforcement–matrix interfacial integrity. Thermomechanical analysis of the composites showed that the use of interconnected wire preforms as reinforcement marginally decreased the average coefficient of thermal expansion of the magnesium matrix. The mechanical characterisation of the composites revealed that the rule of mixture stiffness was closely realised in all the composite materials. The hardness and yield strength increased while the ultimate tensile strength and the ductility of the composite materials were adversely affected. The fracture surface revealed brittle mode of fracture for the matrix and ductile mode of fracture for the iron wire.
Effect of alloying on microstructure and mechanical properties of bainitic high strength plate steels
Authors: Yakubtsov I. A. , Boyd J. D.
Published: February 2008

The X-80 steel chemistry has been modified by increased Mn, Cr and Mo that decrease BS, and two groups of leaner base chemistries have been used with low carbon (LC) and high carbon (HC) that correspond to 0·04 and 0·07 wt-%C respectively. The alloy design approach is to lower BS and to provide offsetting decreases to the carbon equivalent Pcm and alloy mix cost. The final microstructures of plate steels, their tensile and toughness properties were obtained. The effects of alloying on the evolution of final microstructure and mechanical properties were discussed.
Trends in long-term survival of patients with chronic lymphocytic leukemia from the 1980s to the early 21st century
Authors: Brenner Hermann , Gondos Adam , Pulte Dianne
Published: February 2008

Although chronic lymphocytic leukemia (CLL) has remained incurable with standard treatments, newer therapeutic approaches, such as chemoimmunotherapy or stem cell transplantation, bear the potential for prolonged survival. We estimated trends in age-specific 5- and 10-year absolute and relative survival of CLL patients in the United States between 1980-1984 and 2000-2004 from the 1973 to 2004 database of the Surveillance, Epidemiology, and End Results Program. Period analysis was used to disclose recent developments with minimum delay. Overall, 5- and 10-year absolute survival from diagnosis increased from 54.2% to 60.2% (+6 percentage points; P < .0001) and from 27.8% to 34.8% (+7 percentage points; P < .0001), respectively. Despite a strong age gradient in prognosis, increases in 5-year absolute and relative survival over time were rather homogeneous across age groups. In contrast, increases in 10-year absolute and relative survival close to or well above 10% units were observed for all patients younger than 80 years of age at diagnosis compared with no increase at all for older patients. Long-term survival expectations of patients with CLL have substantially improved over the past 2 decades except for patients 80 years of age or older at the time of diagnosis. Future studies are needed to confirm and expand our findings.
FCRL2 expression predicts IGHV mutation status and clinical progression in chronic lymphocytic leukemia
Authors: Li Fu Jun , Ding Shouluan , Pan Jicun , Shakhmatov Mikhail A. , Kashentseva Elena , Wu Jiongru , Li Yufeng , Soong Seng-jaw , Chiorazzi Nicholas , Davis Randall S.
Published: February 2008

CD38 and ZAP-70 are both useful prognostic markers for B-cell chronic lymphocytic leukemia (CLL), but are variably discordant with IGHV mutation status. A total of 5 human Fc receptor–like molecules (FCRL1-5) have tyrosine-based immunoregulatory potential and are expressed by B-lineage subpopulations. To determine their prognostic potential in CLL, FCRL expression was compared with IGHV mutation status, CD38 and ZAP-70 expression, and clinical features from 107 patients. FCRL1, FCRL2, FCRL3, and FCRL5 were found at markedly higher levels on CLL cells bearing mutated IGHV genes than on unmutated CLL cells or CD19+ polyclonal B lymphocytes. Univariate comparisons found that similar to CD38 and ZAP-70, FCRL expression was strongly associated with IGHV mutation status; however, only FCRL2 maintained independent predictive value by multivariate logistic analysis. Strikingly, FCRL2 demonstrated 94.4% concordance with IGHV mutation compared with 76.6% for CD38 and 80.4% for ZAP-70. Compared with other indicators, FCRL2 was also superior at predicting the time to first therapy; the median treatment-free interval was 15.5 years for patients with high FCRL2 expression compared with 3.75 years for FCRL2-low patients. Our studies indicate that FCRL2 has robust predictive value for determining IGHV gene mutation status and clinical progression and thus may further improve prognostic definition in CLL.
Using quality scores and longer reads improves accuracy of Solexa read mapping
Authors: Smith Andrew D , Xuan Zhenyu , Zhang Michael Q
Published: February 2008

Background

Second-generation sequencing has the potential to revolutionize genomics and impact all areas of biomedical science. New technologies will make re-sequencing widely available for such applications as identifying genome variations or interrogating the oligonucleotide content of a large sample (e.g. ChIP-sequencing). The increase in speed, sensitivity and availability of sequencing technology brings demand for advances in computational technology to perform associated analysis tasks. The Solexa/Illumina 1G sequencer can produce tens of millions of reads, ranging in length from ~25–50 nt, in a single experiment. Accurately mapping the reads back to a reference genome is a critical task in almost all applications. Two sources of information that are often ignored when mapping reads from the Solexa technology are the 3' ends of longer reads, which contain a much higher frequency of sequencing errors, and the base-call quality scores.

Results

To investigate whether these sources of information can be used to improve accuracy when mapping reads, we developed the RMAP tool, which can map reads having a wide range of lengths and allows base-call quality scores to determine which positions in each read are more important when mapping. We applied RMAP to analyze data re-sequenced from two human BAC regions for varying read lengths, and varying criteria for use of quality scores. RMAP is freely available for downloading at http://rulai.cshl.edu/rmap/.

Conclusion

Our results indicate that significant gains in Solexa read mapping performance can be achieved by considering the information in 3' ends of longer reads, and appropriately using the base-call quality scores. The RMAP tool we have developed will enable researchers to effectively exploit this information in targeted re-sequencing projects.
The evolution of body size under environmental gradients in ectotherms: why should Bergmann's rule apply to lizards?
Authors: Pincheira-Donoso Daniel , Hodgson David J , Tregenza Tom
Published: February 2008

Background

The impact of environmental gradients on the evolution of life history traits is a central issue in macroecology and evolutionary biology. A number of hypotheses have been formulated to explain factors shaping patterns of variation in animal mass. One such example is Bergmann's rule, which predicts that body size will be positively correlated with latitude and elevation, and hence, with decreasing environmental temperatures. A generally accepted explanation for this phenotypic response is that as body mass increases, body surface area gets proportionally smaller, which contributes to reduced rates of heat-loss. Phylogenetic and non-phylogenetic evidence reveals that endotherms follow Bergmann's rule. In contrast, while previous non-phylogenetic studies supported this prediction in up to 75% of ectotherms, recent phylogenetic comparative analyses suggest that its validity for these organisms is controversial and less understood. Moreover, little attention has been paid to why some ectotherms conform to this rule, while others do not. Here, we investigate Bergmann's rule in the six main clades forming theLiolaemusgenus, one of the largest and most environmentally diverse genera of terrestrial vertebrates. A recent study conducted on some species belonging to four of these six clades concluded thatLiolaemusspecies follow Bergmann's rule, representing the only known phylogenetic support for this model in lizards. However, a later reassessment of this evidence, performed on one of the four analysed clades, produced contrasting conclusions.

Results

Our results fail to support Bergmann's rule inLiolaemuslizards. Non-phylogenetic and phylogenetic analyses showed that none of the studied clades experience increasing body size with increasing latitude and elevation.

Conclusion

Most physiological and behavioural processes in ectotherms depend directly upon their body temperature. In cold environments, adaptations to gain heat rapidly are under strong positive selection to allow optimal feeding, mating and predator avoidance. Therefore, evolution of larger body size in colder environments appears to be a disadvantageous thermoregulatory strategy. The repeated lack of support for Bergmann's rule in ectotherms suggests that this model should be recognized as a valid rule exclusively for endotherms.
Secretion of celiac disease autoantibodies after in vitro gliadin challenge is dependent on small-bowel mucosal transglutaminase 2-specific IgA deposits
Authors: Stenman Satumarja M , Lindfors Katri , Korponay-Szabo Ilma R , Lohi Olli , Saavalainen Päivi , Partanen Jukka , Haimila Katri , Wieser Herbert , Mäki Markku , Kaukinen Katri
Published: February 2008

Background

In celiac disease gluten, the disease-inducing toxic component in wheat, induces the secretion of autoantibodies which are targeted against transglutaminase 2 (TG2). These autoantibodies are produced in the small-intestinal mucosa, where they can be found deposited extracellularly below the epithelial basement membrane and around mucosal blood vessels. In addition, during gluten consumption these autoantibodies can also be detected in patients' serum but disappear from the circulation on a gluten-free diet. Interestingly, after adoption of a gluten-free diet the serum autoantibodies disappear from the circulation more rapidly than the small-intestinal mucosal autoantibody deposits. The toxicity of gluten and the secretion of the disease-specific autoantibodies have been widely studied in organ culture of small-intestinal biopsy samples, but results hitherto have been contradictory. Since the mucosal autoantibodies disappear slowly after a gluten-free diet, our aim was to establish whether autoantibody secretion to organ culture supernatants in treated celiac disease patient biopsies is related to the duration of the diet and further to the pre-existence of mucosal TG2-specific IgA deposits in the cultured biopsy samples.

Results

In the organ culture system conducted with biopsies derived from treated celiac disease patients, gliadin induced secretion of autoantibodies to culture supernatants, reduced epithelial cell height and increased the density of lamina proprial CD25+ cells. However, these changes could be demonstrated only in biopsies from short-term treated celiac disease patients, where the small-intestinal mucosal TG2-specific IgA autoantibody deposits were still present. Furthermore, in these biopsies autoantibody secretion could be stimulated fully only after a 48-hour gliadin challenge.

Conclusion

Our results show that studies focusing on the toxic effects of gliadin in the organ culture system should be carried out with biopsy samples from short-term treated celiac disease patients who are likely still to have mucosal IgA deposits present. In addition to providing an explanation for the discrepancies in previous publications, the present study also enables further validation of the organ culture method.
Fieldable genotyping of Bacillus anthracis and Yersinia pestis based on 25-loci Multi Locus VNTR Analysis
Authors: Ciammaruconi Andrea , Grassi Saverio , De Santis Riccardo , Faggioni Giovanni , Pittiglio Valentina , D'Amelio Raffaele , Carattoli Alessandra , Cassone Antonio , Vergnaud Gilles , Lista Florigio
Published: February 2008

Background

Anthrax and plague are diseases caused by Bacillus anthracis and Yersinia pestis respectively. These bacteria are etiological agents for worldwide zoonotic diseases and are considered among the most feared potential bioterror agents. Strain differentiation is difficult for these microorganisms because of their high intraspecies genome homogeneity. Moreover, fast strain identification and comparison with known genotypes may be crucial for naturally occurring outbreaks versus bioterrorist events discrimination.

Results

Thirty-nine B. anthracis and ten Y. pestis strains, representative of the species genetic diversity, were genotyped by Agilent 2100 Bioanalyzer using previously described Multiple Locus VNTR Analysis assays (MLVA). Results were compared to previous data obtained by standard genotyping system (capillary electrophoresis on automatic sequencer) and, when necessary, direct amplicon sequencing. A reference comparison table containing actual fragment sizes, sequencer sizes and Agilent sizes was produced.

Conclusion

In this report an automated DNA electrophoresis apparatus which provides a cheaper alternative compared to capillary electrophoresis approaches was applied for genotyping of B. anthracis and Y. pesti s. This equipment, uses pre-cast gels and provides easy transportation, low maintenance and overall general logistic requirements and costs, is easy to set up and provides rapid analysis. This platform is a candidate for on-site MLVA genotyping of biothreat agents as well as other bacterial pathogens. It is an alternative to the more expensive and demanding capillary electrophoresis methods, and to the less expensive but more time-consuming classical gel electrophoresis approach.
Study of the role of Mce3R on the transcription of mce genes of Mycobacterium tuberculosis
Authors: Santangelo María P , Blanco Federico C , Bianco María V , Klepp Laura I , Zabal Osvaldo , Cataldi Angel A , Bigi Fabiana
Published: February 2008

Background

mce3 is one of the four virulence-related mce operons of Mycobacterium tuberculosis. In a previous work we showed that the overexpression of Mce3R in Mycobacterium smegmatis and M. tuberculosis abolishes the expression of lacZ fused to the mce3 promoter, indicating that Mce3R represses mce3 transcription.

Results

We obtained a knockout mutant strain of M. tuberculosis H37Rv by inserting a hygromycin cassette into the mce3R gene. The mutation results in a significant increase in the expression of mce3 genes either in vitro or in a murine cell macrophages line as it was determined using promoter-lacZ fusions in M. tuberculosis. The abundance of mce1, mce2 and mce4 mRNAs was not affected by this mutation as it was demonstrated by quantitative RT-PCR. The mce3R promoter activity in the presence of Mce3R was significantly reduced compared with that in the absence of the regulator, during the in vitro culture of M. tuberculosis.

Conclusion

Mce3R repress the transcription of mce3 operon and self regulates its own expression but does not affect the transcription of mce1, mce2 and mce4 operons of M. tuberculosis.
AtMRP6/AtABCC6, an ATP-Binding Cassette transporter gene expressed during early steps of seedling development and up-regulated by cadmium in Arabidopsis thaliana
Authors: Gaillard Stéphane , Jacquet Hélène , Vavasseur Alain , Leonhardt Nathalie , Forestier Cyrille
Published: February 2008

Background

ABC proteins constitute one of the largest families of transporters found in all living organisms. In Arabidopsis thaliana, 120 genes encoding ABC transporters have been identified. Here, the characterization of one member of the MRP subclass, AtMRP6, is described.

Results

This gene, located on chromosome 3, is bordered by AtMRP3 and AtMRP7. Using real-time quantitative PCR (RT-Q-PCR) and the GUS reporter gene, we found that this gene is essentially expressed during early seedling development, in the apical meristem and at initiation point of secondary roots, especially in xylem-opposite pericycle cells where lateral roots initiate. The level of expression of AtMRP6 in response to various stresses was explored and a significant up-regulation after cadmium (Cd) treatment was detected. Among the three T-DNA insertion lines available from the Salk Institute library, two knock-out mutants, Atmrp6.1 and Atmrp6.2 were invalidated for the AtMRP6 gene. In the presence of Cd, development of leaves was more affected in the mutants than wild-type plants, whereas root elongation and ramification was comparable.

Conclusion

The position of AtMRP6 on chromosome 3, flanked by two other MRP genes, (all of which being induced by Cd) suggests that AtMRP6 is part of a cluster involved in metal tolerance, although additional functions in planta cannot be discarded.
Ankle blood pressure as a predictor of total and cardiovascular mortality
Authors: Hietanen Heikki , Pääkkönen Rauni , Salomaa Veikko
Published: February 2008

Background

The ankle blood pressure is commonly used as a ratio to the brachial blood pressure, called ankle-brachial index (ABI). Very few studies have considered the independent value of the ankle blood pressure without indexing it to the brachial blood pressure. We examined the value of ankle blood pressure, together with the exercise blood pressure, as a predictor of cardiovascular (CVD) and total mortality.

Methods

A prospective follow-up study of 3,858 consecutive ambulatory patients (mean age 51 years, 65,9% male) referred to a symptom-limited exercise test between August 1989 and December 1995. The cohort was followed up for all-cause and CVD mortality until December 31, 2004, by record linkage with the National Causes-of-Death Register. The independent value of ankle blood pressure as a predictor of cardiovascular and total mortality was assessed using Cox proportional hazards modelling.

Results

The average follow-up time was 14 years, during which 346 persons died, 108 of them due to CVD. Persons with normal (<140 mmHg) resting brachial blood pressure, ankle blood pressure < 175 mmHg and exercise blood pressure at moderate exercise level ≤215 mmHg at baseline investigation, had the best prognosis and were taken as the reference category. Among persons with elevated ankle blood pressure (≥175 mmHg) but normal or borderline resting brachial pressure and normal exercise blood pressure (≤215 mmHg) at moderate exercise level the multivariate-adjusted hazard ratios (HR, 95% confidence interval) for CVD and total mortality were 2.70 (1.52 – 4.80) and 2.13 (1.58 – 2.85), respectively. Similar and equally significant HRs were observed in persons with both elevated ankle blood pressure and elevated exercise blood pressure, as well as in those persons with elevated exercise blood pressure but ankle blood pressure < 175 mmHg.

Conclusion

These results suggest that the ankle blood pressure has an independent value as a marker of arterial stiffness or subclinical atherosclerosis and a risk of future mortality in middle-aged, asymptomatic persons.
Transmitted drug resistance, selection of resistance mutations and moderate antiretroviral efficacy in HIV-2: Analysis of the HIV-2 Belgium and Luxembourg database
Authors: Ruelle Jean , Roman François , Vandenbroucke Anne-Thérèse , Lambert Christine , Fransen Katrien , Echahidi Fedoua , Piérard Denis , Verhofstede Chris , Van Laethem Kristel , Delforge Marie-Luce , Vaira Dolorès , Schmit Jean-Claude , Goubau Patrick
Published: February 2008

Background

Guidelines established for the treatment of HIV-1 infection and genotype interpretation do not apply for HIV-2. Data about antiretroviral (ARV) drug efficacy and resistance mutations is scarce.

Methods

Clinical data about HIV-2 infected patients in Belgium and Luxembourg were collected and the effect of ARV therapy on plasma viral load and CD4 counts were analysed. Viral RNA encoding for protease (PR) and reverse transcriptase (RT) from ARV-naïve and treated patients were sequenced.

Results

Sixty-five HIV-2 infected patients were included in this cohort. Twenty patients were treated with 25 different ARV combinations in a total of 34 regimens and six months after the start of ARV therapy, only one third achieved viral load suppression. All of these successful regimens bar one contained protease inhibitors (PIs). Mean CD4 gains in the group of viral load suppressors and the group of patients treated with PI-containing regimens were respectively significantly higher than in the group of non-suppressors and the group of PI-sparing regimens. The most frequent mutations selected under therapy (compared to HIV-2 ROD) were V71I, L90M and I89V within PR. Within RT, they were M184V, Q151M, V111I and K65R. All of these mutations, except K65R and M184V, were also found in variable proportions in ARV-naïve patients.

Conclusion

Despite a high rate of ARV treatment failure, better virological and immunological results were achieved with PI-containing regimens. The analysis of polymorphic positions and HIV-2 specific mutations selected during therapy showed for the first time that transmission of drug resistant viruses has occurred in Belgium and Luxembourg. The high heterogeneity in ARV combinations reflects a lack of guidelines for the treatment of HIV-2 infection.
A review on slurry bioreactors for bioremediation of soils and sediments
Authors: Robles-González Ireri V , Fava Fabio , Poggi-Varaldo Héctor M
Published: February 2008

The aim of this work is to present a critical review on slurry bioreactors (SB) and their application to bioremediation of soils and sediments polluted with recalcitrant and toxic compounds. The scope of the review encompasses the following subjects: (i) process fundamentals of SB and analysis of advantages and disadvantages; (ii) the most recent applications of SB to laboratory scale and commercial scale soil bioremediation, with a focus on pesticides, explosives, polynuclear aromatic hydrocarbons, and chlorinated organic pollutants; (iii) trends on the use of surfactants to improve availability of contaminants and supplementation with degradable carbon sources to enhance cometabolism of pollutants; (iv) recent findings on the utilization of electron acceptors other than oxygen; (v) bioaugmentation and advances made on characterization of microbial communities of SB; (vi) developments on ecotoxicity assays aimed at evaluating bioremediation efficiency of the process.

From this review it can be concluded that SB is an effective ad situ and ex situ technology that can be used for bioremediation of problematic sites, such as those characterized by soils with high contents of clay and organic matter, by pollutants that are recalcitrant, toxic, and display hysteretic behavior, or when bioremediation should be accomplished in short times under the pressure and monitoring of environmental agencies and regulators. SB technology allows for the convenient manipulation and control of several environmental parameters that could lead to enhanced and faster treatment of polluted soils: nutrient N, P and organic carbon source (biostimulation), inocula (bioaugmentation), increased availability of pollutants by use of surfactants or inducing biosurfactant production inside the SB, etc. An interesting emerging area is the use of SB with simultaneous electron acceptors, which has demonstrated its usefulness for the bioremediation of soils polluted with hydrocarbons and some organochlorinated compounds. Characterization studies of microbial communities of SB are still in the early stages, in spite of their significance for improving reactor operation and design optimization.

We have identified the following niches of research needs for SB in the near and mid term future, inter alia: (i) application of SB with sequential and simultaneous electron acceptors to soils polluted with contaminants other than hydrocarbons (i.e., pesticides, explosives, etc.), (ii) evaluation of the technical feasibility of triphasic SB that use innocuous solvents to help desorbing pollutants strongly attached to soils, and in turn, to enhance their biodegradation, (iii) gaining deeper insight of microbial communities present in SB with the intensified application of molecular biology tools such as PCR-DGGE, PCR-TGGE, ARDRA, etc., (iv) development of more representative ecotoxicological assays to better assess the effectiveness of a given bioremediation process.
The influence of obesity on falls and quality of life
Authors: Fjeldstad Cecilie , Fjeldstad Anette S , Acree Luke S , Nickel Kevin J , Gardner Andrew W
Published: February 2008

Objective

To determine (1) whether obese older adults had higher prevalence of falls and ambulatory stumbling, impaired balance and lower health-related quality of life (HRQL) than their normal weight counterparts, and (2) whether the falls and balance measures were associated with HRQL in obese adults.

Methods

Subjects who had a body mass index (BMI) greater than 30 kg/m2 were classified into an obese group (n = 128) while those with BMI between 18.5 and 24.9 kg/m2 were included into a normal weight group (n = 88). Functional tests were performed to assess balance, and questionnaires were administered to assess history of falls, ambulatory stumbling, and HRQL.

Results

The obese group reported a higher prevalence of falls (27% vs. 15%), and ambulatory stumbling (32% vs. 14%) than the normal weight group. Furthermore, the obese group had lower HRQL, (p ≤ 0.05) for physical function (63 ± 27 vs. 75 ± 26; mean ± SD), role-physical (59 ± 40 vs. 74 ± 37), vitality (58 ± 23 vs. 66 ± 20), bodily pain (62 ± 25 vs. 74 ± 21) and general health (64 ± 19 vs. 70 ± 18). In the obese group, a history of falls was related (p ≤ 0.05) to lower scores in 4 domains of HRQL, and ambulatory stumbling was related (p ≤ 0.01) to 7 domains.

Conclusion

In middle-aged and older adults, obesity was associated with a higher prevalence of falls and stumbling during ambulation, as well as lower values in multiple domains of HRQL. Furthermore, a history of falls and ambulatory stumbling were related to lower measures of HRQL in obese adults.
Over-expression of glutamine synthase in focal nodular hyperplasia (part 1): Early stages in the formation support the hypothesis of a focal hyper-arterialisation with venous (portal and hepatic) and biliary damage
Authors: Bioulac-Sage Paulette , Laumonier Hervé , Cubel Gaëlle , Saric Jean , Balabaud Charles
Published: February 2008

Background

Most focal nodular hyperplasia (FNH) cases are diagnosed by chance. We studied a case of pre-FNH. We used glutamine synthase as an immunohistochemical marker for perivenous zones.

Results

Neither fibrotic scars nor hepatocytic nodules surrounded by fibrosis with a ductular reaction were observed in the sections studied. Most sections generally displayed preserved architecture. The glutamine synthase-positive hepatocyte areas were wider than those observed in non-tumoural surrounding liver, and they tended to extend outwards. Portal tracts bordering the nodule were more fibrotic, with an absence of portal veins and ducts and with arterial proliferation often in proximity with large draining veins; isolated arteries were present and hepatic veins were rare in the nodule. These features appeared prior to the identification of other major criteria characteristics of FNH, thus supporting the "hypothesis of Wanless".

Conclusion

The findings confirm that in FNH there is a portal tract injury leading to local portal vein injury. This leads to a cascade of events, including arterial venous shunts, ductular reaction, and scar formation.
Inhibition of oncogene-induced inflammatory chemokines using a farnesyltransferase inhibitor
Authors: DeGeorge Katharine C , DeGeorge Brent R , Testa James S , Rothstein Jay L
Published: February 2008

Background

Farnesyltransferase inhibitors (FTI) are small molecule agents originally formulated to inhibit the oncogenic functions of Ras. Although subsequent analysis of FTI activity revealed wider effects on other pathways, the drug has been demonstrated to reduce Ras signaling by direct measurements. The purpose of the current study was to determine if FTI could be used to inhibit the inflammatory activities of a known Ras-activating human oncoprotein, RET/PTC3. RET/PTC3 is a fusion oncoprotein expressed in the thyroid epithelium of patients afflicted with thyroid autoimmune disease and/or differentiated thyroid carcinoma. Previous studies have demonstrated that RET/PTC3 signals through Ras and can provoke nuclear translocation of NFκB and the downstream release of pro-inflammatory mediators from thyroid follicular cells in vitro and in vivo, making it an ideal target for studies using FTI.

Methods

For the studies described here, an in vitro assay was developed to measure FTI inhibition of RET/PTC3 pro-inflammatory effects. Rat thyrocytes transfected with RET/PTC3 or vector control cDNA were co-cultured with FTI and examined for inhibition of chemokine expression and secretion measured by RT-PCR and ELISA. Immunoblot analysis was used to confirm the level at which FTI acts on RET/PTC3-expressing cells, and Annexin V/PI staining of cells was used to assess cell death in RET/PTC3-expressing cells co-cultured with FTI.

Results

These analyses revealed significant mRNA and protein inhibition of chemokines Ccl2 and Cxcl1 with nanomolar doses of FTI. Neither RET/PTC3 protein expression nor apoptosis were affected at any dose of FTI investigated.

Conclusion

These data suggest that FTI may be applied as an effective inhibitor for RET/PTC3-oncogene induced pro-inflammatory mediators.
Asymmetry and structural system analysis of the proximal femur meta-epiphysis: osteoarticular anatomical pathology
Authors: Samaha Ali A , Ivanov Alexander V , Haddad John J , Kolesnik Alexander I , Baydoun Safaa , Arabi Maher R , Yashina Irena N , Samaha Rana A , Ivanov Dimetry A
Published: February 2008

Background

The human femur is commonly considered as a subsystem of the locomotor apparatus with four conspicuous levels of organization. This phenomenon is the result of the evolution of the locomotor apparatus, which encompasses both constitutional and individual variability. The work therein reported, therefore, underlies the significance of observing anatomical system analysis of the proximal femur meta-epiphysis in normal conditions, according to the anatomic positioning with respect to the right or left side of the body, and the presence of system asymmetry in the meta-epiphysis structure, thus indicating structural and functional asymmetry.

Methods

A total of 160 femur bones of both sexes were compiled and a morphological study of 15 linear and angulated parameters of proximal femur epiphysis was produced, thus defining the linear/angulated size of tubular bones. The parameters were divided into linear and angulated groups, while maintaining the motion of the hip joint and transmission of stress to the unwanted parts of the limb. Furthermore, the straight and vertical diameters of the femoral head and the length of the femoral neck were also studied. The angle between the neck and diaphysis, the neck antiversion and angle of rotation of the femoral neck were subsequently measured. Finally, the condylo-diaphyseal angle with respect to the axis of extremity was determined. To visualize the force of intersystem ties, we have used the method of correlation galaxy construction.

Results

The absolute numeral values of each linear parameter were transformed to relative values. The values of superfluity coefficient for each parameter in the right and left femoral bone groups were estimated and Pearson's correlation coefficient has been calculated (> 0.60). Retrospectively, the observed results have confirmed the presence of functional asymmetry in the proximal femur meta-epiphysis. On the basis of compliance or insignificant difference in the confidence interval of the linear parameters, we have revealed, therefore, a discrepancy in values between the neck and the diaphysis angle and the angle of femoral neck rotation (range displacement of confident interval to a greater degree to the right).

Conclusion

This study assessed the observations of a systemic anatomical study encompassing the proximal femur meta-epiphysis behavior in normal condition. This work has significance in medical practice as the theoretical basis is also required in knowing the decreased frequency and degree of severity of osteoarthritic pathologies in the dominant lower extremity.